Homebrew PCBs

I searched but weren't able to locate any posts on the subject but I 
recall that tehre was a dicussion of it. Does anyone know a simple 
method that works on plating holes in a PCB?  Mike

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> I searched but weren't able to locate any posts on the subject but 
I 
> recall that tehre was a dicussion of it. Does anyone know a simple 
> method that works on plating holes in a PCB?  Mike

I think the best home-brew (closer to professional sho) unit is from 
Markus

http://www.myhome.ch/mzingg/pcbstuff/tps/


Also go back to the posts around 1100, maybe go directly to 1108 and 
start reading.   IIRC, there was a detailed list of each step needed.

This is not for the faint of heart nor a simple one shot project.


On the other side of things, there is a simple method from think and 
tinker that plates the holes with a silver compound.  not cheap.

And there has been some mention of using carbon black as a method.  
look around message 170.

also post 1163  and 2344

Interestlingly there is not a lot of posts regarding this.  I would 
have hoped someone would have figured out how to do it easier.


IIRC, there was a gentleman who posted quite a bit about carbon black 
and his findings about using that to create the connections.

Most of use try to use single sided boards to the greatest level and 
then add as few jumpers as possible.  As Stefan pointed out recently, 
a resistor is a zero hole connection.  so, if you can, use your thru-
hole devices as ways to connect both sides of the boards.

And if you find you are doing a lot near an IC, you can take a 
machined pin IC socket and pull out all the pins and press them into 
the holes on the board and then solder from both sides.

Dave

I posted a pic in the photos section (cdaws folder) of what my PCBs look like using T&T method.of PTH I no longer consider it expensive, as one small bottle has now lasted me for about 6 months well over a few thousand holes. I'll put a high res in the files section too. 
JT

----- Original Message ----- 
  From: Dave Mucha 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Thursday, July 29, 2004 1:31 AM
  Subject: [Homebrew_PCBs] Re: Plating thruholes.


  --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
  > I searched but weren't able to locate any posts on the subject but 
  I 
  > recall that tehre was a dicussion of it. Does anyone know a simple 
  > method that works on plating holes in a PCB?  Mike



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[Non-text portions of this message have been removed]

Excellent info, Dave. I wish Marcus provided email to ocntact him.

Mike

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...> 
wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
> > I searched but weren't able to locate any posts on the subject 
but 
> I 
> > recall that tehre was a dicussion of it. Does anyone know a 
simple 
> > method that works on plating holes in a PCB?  Mike
> 
> I think the best home-brew (closer to professional sho) unit is 
from 
> Markus
> 
> http://www.myhome.ch/mzingg/pcbstuff/tps/
> 
> 
> Also go back to the posts around 1100, maybe go directly to 1108 
and 
> start reading.   IIRC, there was a detailed list of each step 
needed.
> 
> This is not for the faint of heart nor a simple one shot project.
> 
> 
> On the other side of things, there is a simple method from think 
and 
> tinker that plates the holes with a silver compound.  not cheap.
> 
> And there has been some mention of using carbon black as a method.  
> look around message 170.
> 
> also post 1163  and 2344
> 
> Interestlingly there is not a lot of posts regarding this.  I would 
> have hoped someone would have figured out how to do it easier.
> 
> 
> IIRC, there was a gentleman who posted quite a bit about carbon 
black 
> and his findings about using that to create the connections.
> 
> Most of use try to use single sided boards to the greatest level 
and 
> then add as few jumpers as possible.  As Stefan pointed out 
recently, 
> a resistor is a zero hole connection.  so, if you can, use your 
thru-
> hole devices as ways to connect both sides of the boards.
> 
> And if you find you are doing a lot near an IC, you can take a 
> machined pin IC socket and pull out all the pins and press them 
into 

> the holes on the board and then solder from both sides.
> 
> Dave

m.zingg@...

No problem

Markus

>Excellent info, Dave. I wish Marcus provided email to ocntact him.
>
>Mike
>
>--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...> 
>wrote:
>> --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
>wrote:
>> > I searched but weren't able to locate any posts on the subject 
>but 
>> I 
>> > recall that tehre was a dicussion of it. Does anyone know a 
>simple 
>> > method that works on plating holes in a PCB?  Mike
>> 
>> I think the best home-brew (closer to professional sho) unit is 
>from 
>> Markus
>> 
>> http://www.myhome.ch/mzingg/pcbstuff/tps/
>> 
>> 
>> Also go back to the posts around 1100, maybe go directly to 1108 
>and 
>> start reading.   IIRC, there was a detailed list of each step 
>needed.
>> 
>> This is not for the faint of heart nor a simple one shot project.
>> 
>> 
>> On the other side of things, there is a simple method from think 
>and 
>> tinker that plates the holes with a silver compound.  not cheap.
>> 
>> And there has been some mention of using carbon black as a method.  
>> look around message 170.
>> 
>> also post 1163  and 2344
>> 
>> Interestlingly there is not a lot of posts regarding this.  I would 
>> have hoped someone would have figured out how to do it easier.
>> 
>> 
>> IIRC, there was a gentleman who posted quite a bit about carbon 
>black 
>> and his findings about using that to create the connections.
>> 
>> Most of use try to use single sided boards to the greatest level 
>and 
>> then add as few jumpers as possible.  As Stefan pointed out 
>recently, 
>> a resistor is a zero hole connection.  so, if you can, use your 
>thru-
>> hole devices as ways to connect both sides of the boards.
>> 
>> And if you find you are doing a lot near an IC, you can take a 
>> machined pin IC socket and pull out all the pins and press them 
>into 
>> the holes on the board and then solder from both sides.
>> 
>> Dave
>
>
>
>
>Be sure to visit the group home and check for new Bookmarks and files:
>http://groups.yahoo.com/group/Homebrew_PCBs 
>Yahoo! Groups Links
>
>
>
>

I can't believe- Markus is a member of this board! It is a very 
professionally looking setup that you created.

Have you been able to provide few words that people could follow your 
idea of plating thru?

Picture with two copper plates and a airating tube in between: how 
are the plates connected to the PS?  Both are conencted to each other 
and then they are connected to + and - ?!?!

Mike




--- In Homebrew_PCBs@yahoogroups.com, Markus Zingg <m.zingg@n...> 
wrote:
> 
> 
> m.zingg@n...
> 
> No problem
> 
> Markus
> 
> >Excellent info, Dave. I wish Marcus provided email to ocntact him.
> >
> >Mike
> >
> >--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" 
<dave_mucha@y...> 
> >wrote:
> >> --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
> >wrote:
> >> > I searched but weren't able to locate any posts on the subject 
> >but 
> >> I 
> >> > recall that tehre was a dicussion of it. Does anyone know a 
> >simple 
> >> > method that works on plating holes in a PCB?  Mike
> >> 
> >> I think the best home-brew (closer to professional sho) unit is 
> >from 
> >> Markus
> >> 
> >> http://www.myhome.ch/mzingg/pcbstuff/tps/
> >> 
> >> 
> >> Also go back to the posts around 1100, maybe go directly to 1108 
> >and 
> >> start reading.   IIRC, there was a detailed list of each step 
> >needed.
> >> 
> >> This is not for the faint of heart nor a simple one shot project.
> >> 
> >> 
> >> On the other side of things, there is a simple method from think 
> >and 
> >> tinker that plates the holes with a silver compound.  not cheap.
> >> 
> >> And there has been some mention of using carbon black as a 
method.  
> >> look around message 170.
> >> 
> >> also post 1163  and 2344
> >> 
> >> Interestlingly there is not a lot of posts regarding this.  I 
would 
> >> have hoped someone would have figured out how to do it easier.
> >> 
> >> 
> >> IIRC, there was a gentleman who posted quite a bit about carbon 
> >black 
> >> and his findings about using that to create the connections.
> >> 
> >> Most of use try to use single sided boards to the greatest level 
> >and 
> >> then add as few jumpers as possible.  As Stefan pointed out 
> >recently, 
> >> a resistor is a zero hole connection.  so, if you can, use your 
> >thru-
> >> hole devices as ways to connect both sides of the boards.
> >> 
> >> And if you find you are doing a lot near an IC, you can take a 
> >> machined pin IC socket and pull out all the pins and press them 
> >into 
> >> the holes on the board and then solder from both sides.
> >> 
> >> Dave
> >
> >
> >
> >
> >Be sure to visit the group home and check for new Bookmarks and 
files:

> >http://groups.yahoo.com/group/Homebrew_PCBs 
> >Yahoo! Groups Links
> >
> >
> >
> >

On Thu, 29 Jul 2004 12:16:53 -0000, mikezcnc <eemikez@...> wrote:

> I can't believe- Markus is a member of this board! It is a very
> professionally looking setup that you created.
>
> Have you been able to provide few words that people could follow your
> idea of plating thru?
>
> Picture with two copper plates and a airating tube in between: how
> are the plates connected to the PS?  Both are conencted to each other
> and then they are connected to + and - ?!?!
>
> Mike
>

What did you expect? that there is anyone out there able to spell PCB and
not a list member.... nah ;-)
The setup of Markus is very nice indeed, I'd quite like to have a similar
unit but the cost of the chemicals (only the starter set) is too much for 
me
at this point. Also i'd rather not convert to dry film resist because
TT is working sooo nice.

the plates have both the same polarity i believe and the PCB is wired 
(through the
holder) to the other. (Which one is which i dunno, i'd guess the pcb must 
be +)

Oh yea, just so you know, Markus is making 4-layer with it too.
(you are imagining the envy in this sentence..... ;-))

ST

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> I can't believe- Markus is a member of this board! It is a very 
> professionally looking setup that you created.


That is what I was trying to say to Ballendo.  the 'brain trust' on 
this board peaks in the 'making PCB's area and is THE place to get 
ansers when you want to make PCB's.

And yes, Markus holds the bar very high for the rest of us !
I just wish he were close by my area.   

There is a NJ robotics society and one of the guys and a laser board 
etcher.  about 4 ft cube.  Wanna talk about envy ?  Problem for me is 
that he is too far away....

Oh, may I respectfully request that you keep your questions on the 
open list and not in personal e-mails?  the rest of us would like to 
listen in.


Dave

While I'll admit Markus's plating system is a piece of working art, to do plated holes you do not have to be so talented in design and fabrication. A simple 2-5 Gallon plastic bucket, two copper anodes, A power supply, (could be as simple as a car battery charger) and some way to regulate the power( could be a simple as a lamp dimmer) You could use two anodes, or just one (but you'd have to flip the board) 
In my tank, the anodes (4X6) are not as big as the pcb(6X9), and this does not matter as much as copper is plated out of the solution, more than it is directly from the anodes - I also have a larger distance between the pcb and anodes.

The kit from Caswell includes 2 buckets, heater, anodes, cleaning and plating chems. It works very well with the ink, and less than $200 for a complete but- minimal system.  

JT
http://www.soundclick.com/jtsound

  ----- Original Message ----- 
  From: Dave Mucha 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Thursday, July 29, 2004 11:53 AM
  Subject: [Homebrew_PCBs] Re: Plating thruholes.


  --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
  > I can't believe- Markus is a member of this board! It is a very 
  > professionally looking setup that you created.


  That is what I was trying to say to Ballendo.  the 'brain trust' on 
  this board peaks in the 'making PCB's area and is THE place to get 
  ansers when you want to make PCB's.

  And yes, Markus holds the bar very high for the rest of us !
  I just wish he were close by my area.   

  There is a NJ robotics society and one of the guys and a laser board 
  etcher.  about 4 ft cube.  Wanna talk about envy ?  Problem for me is 
  that he is too far away....

  Oh, may I respectfully request that you keep your questions on the 
  open list and not in personal e-mails?  the rest of us would like to 
  listen in.


  Dave






  Be sure to visit the group home and check for new Bookmarks and files:
  http://groups.yahoo.com/group/Homebrew_PCBs 


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[Non-text portions of this message have been removed]

Jeremy, 
That's what I was thinking that it looked too involved. Thanks for 
mentioning. Now, if we only could mix our own 'hole ligner'.

Mike
--- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" <jeremy@e...> 
wrote:
> While I'll admit Markus's plating system is a piece of working art, 
to do plated holes you do not have to be so talented in design and 
fabrication. A simple 2-5 Gallon plastic bucket, two copper anodes, A 
power supply, (could be as simple as a car battery charger) and some 
way to regulate the power( could be a simple as a lamp dimmer) You 
could use two anodes, or just one (but you'd have to flip the board) 
> In my tank, the anodes (4X6) are not as big as the pcb(6X9), and 
this does not matter as much as copper is plated out of the solution, 
more than it is directly from the anodes - I also have a larger 
distance between the pcb and anodes.
> 
> The kit from Caswell includes 2 buckets, heater, anodes, cleaning 
and plating chems. It works very well with the ink, and less than 
$200 for a complete but- minimal system.  
> 
> JT
> http://www.soundclick.com/jtsound
>   ----- Original Message ----- 
>   From: Dave Mucha 
>   To: Homebrew_PCBs@yahoogroups.com 
>   Sent: Thursday, July 29, 2004 11:53 AM
>   Subject: [Homebrew_PCBs] Re: Plating thruholes.
> 
> 
>   --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>   > I can't believe- Markus is a member of this board! It is a very 
>   > professionally looking setup that you created.
> 
> 
>   That is what I was trying to say to Ballendo.  the 'brain trust' 
on 
>   this board peaks in the 'making PCB's area and is THE place to 
get 
>   ansers when you want to make PCB's.
> 
>   And yes, Markus holds the bar very high for the rest of us !
>   I just wish he were close by my area.   
> 
>   There is a NJ robotics society and one of the guys and a laser 
board 
>   etcher.  about 4 ft cube.  Wanna talk about envy ?  Problem for 
me is 
>   that he is too far away....
> 
>   Oh, may I respectfully request that you keep your questions on 
the 
>   open list and not in personal e-mails?  the rest of us would like 
to 
>   listen in.
> 
> 
>   Dave
> 
> 
> 
> 
> 
> 
>   Be sure to visit the group home and check for new Bookmarks and 
files:
>   http://groups.yahoo.com/group/Homebrew_PCBs 
> 
> 
>         Yahoo! Groups Sponsor 
>               ADVERTISEMENT
>              
>        
>        
> 
> 
> --------------------------------------------------------------------
----------
>   Yahoo! Groups Links
> 
>     a.. To visit your group on the web, go to:
>     http://groups.yahoo.com/group/Homebrew_PCBs/
>       
>     b.. To unsubscribe from this group, send an email to:
>     Homebrew_PCBs-unsubscribe@yahoogroups.com
>       
>     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of 
Service. 

> 
> 
> 
> [Non-text portions of this message have been removed]

Jeremy, would you suggest 
http://www.caswellplating.com/kits/copper.htm or this 
http://www.caswellplating.com/kits/flashcopper.html  Mike

--- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" <jeremy@e...> 
wrote:
> While I'll admit Markus's plating system is a piece of working art, 
to do plated holes you do not have to be so talented in design and 
fabrication. A simple 2-5 Gallon plastic bucket, two copper anodes, A 
power supply, (could be as simple as a car battery charger) and some 
way to regulate the power( could be a simple as a lamp dimmer) You 
could use two anodes, or just one (but you'd have to flip the board) 
> In my tank, the anodes (4X6) are not as big as the pcb(6X9), and 
this does not matter as much as copper is plated out of the solution, 
more than it is directly from the anodes - I also have a larger 
distance between the pcb and anodes.
> 
> The kit from Caswell includes 2 buckets, heater, anodes, cleaning 
and plating chems. It works very well with the ink, and less than 
$200 for a complete but- minimal system.  
> 
> JT
> http://www.soundclick.com/jtsound
>   ----- Original Message ----- 
>   From: Dave Mucha 
>   To: Homebrew_PCBs@yahoogroups.com 
>   Sent: Thursday, July 29, 2004 11:53 AM
>   Subject: [Homebrew_PCBs] Re: Plating thruholes.
> 
> 
>   --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>   > I can't believe- Markus is a member of this board! It is a very 
>   > professionally looking setup that you created.
> 
> 
>   That is what I was trying to say to Ballendo.  the 'brain trust' 
on 
>   this board peaks in the 'making PCB's area and is THE place to 
get 
>   ansers when you want to make PCB's.
> 
>   And yes, Markus holds the bar very high for the rest of us !
>   I just wish he were close by my area.   
> 
>   There is a NJ robotics society and one of the guys and a laser 
board 
>   etcher.  about 4 ft cube.  Wanna talk about envy ?  Problem for 
me is 
>   that he is too far away....
> 
>   Oh, may I respectfully request that you keep your questions on 
the 
>   open list and not in personal e-mails?  the rest of us would like 
to 
>   listen in.
> 
> 
>   Dave
> 
> 
> 
> 
> 
> 
>   Be sure to visit the group home and check for new Bookmarks and 
files:
>   http://groups.yahoo.com/group/Homebrew_PCBs 
> 
> 
>         Yahoo! Groups Sponsor 
>               ADVERTISEMENT
>              
>        
>        
> 
> 
> --------------------------------------------------------------------
----------
>   Yahoo! Groups Links
> 
>     a.. To visit your group on the web, go to:
>     http://groups.yahoo.com/group/Homebrew_PCBs/
>       
>     b.. To unsubscribe from this group, send an email to:
>     Homebrew_PCBs-unsubscribe@yahoogroups.com
>       
>     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of 
Service. 

> 
> 
> 
> [Non-text portions of this message have been removed]

I have used both. 
I prefer Flash copper but either will work well.
JT

  ----- Original Message ----- 
  From: mikezcnc 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Thursday, July 29, 2004 4:10 PM
  Subject: [Homebrew_PCBs] Re: Plating thruholes.


  Jeremy, would you suggest 
  http://www.caswellplating.com/kits/copper.htm or this 
  http://www.caswellplating.com/kits/flashcopper.html  Mike



[Non-text portions of this message have been removed]

Thanks, Jeremy. Mike

--- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" <jeremy@e...> 
wrote:

> I have used both. 
> I prefer Flash copper but either will work well.
> JT
> 
>   ----- Original Message ----- 
>   From: mikezcnc 
>   To: Homebrew_PCBs@yahoogroups.com 
>   Sent: Thursday, July 29, 2004 4:10 PM
>   Subject: [Homebrew_PCBs] Re: Plating thruholes.
> 
> 
>   Jeremy, would you suggest 
>   http://www.caswellplating.com/kits/copper.htm or this 
>   http://www.caswellplating.com/kits/flashcopper.html  Mike
> 
> 
> 
> [Non-text portions of this message have been removed]

Dave Mucha wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> 
>>I searched but weren't able to locate any posts on the subject but 
> 
> I 
> 
>>recall that tehre was a dicussion of it. Does anyone know a simple 
>>method that works on plating holes in a PCB?  Mike
> 
> 
> I think the best home-brew (closer to professional sho) unit is from 
> Markus
> 
> http://www.myhome.ch/mzingg/pcbstuff/tps/
> 
> 
> Also go back to the posts around 1100, maybe go directly to 1108 and 
> start reading.   IIRC, there was a detailed list of each step needed.
> 
> This is not for the faint of heart nor a simple one shot project.

This is very true. The electroplating, and application of your own 
photoresists is the other major parts of the PTH process.

In addition to etching, and photo imaging, you must;

1) cleaning PCB surface to prepare for electroplating.
2) ability to apply your own dry film photoresist
3) give holes the ability to plate.
4) setup acid copper electroplating tank with proprietary additives.

There are several methods of doing (3), such as with carbon dispersion, 
  electroless copper solutions, or with palladium colloid solutions. I 
believe Markus's setup is using the palladium colloid solutions. All 
three processes have their problems, and I would say the most critical 
step in the process.

Let me know if you have any questions.

Adam

Adam
Flash copper (Alkaline) works better for me than acid copper. In the future you might just want to say "copper plating" leaving "acid" out as there is more than one way to plate copper. 

A quick dip in HOT tsp (tri sodium phosphate) does a great job of pre-plate - pre lamination cleaning, and I suspect it would also work well for tt (no sandpaper needed)

JT

  ----- Original Message ----- 
  From: Adam Seychell 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Thursday, July 29, 2004 9:05 PM
  Subject: Re: [Homebrew_PCBs] Re: Plating thruholes.


  Dave Mucha wrote:
  > --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
  > 
  >>I searched but weren't able to locate any posts on the subject but 
  > 
  > I 
  > 
  >>recall that tehre was a dicussion of it. Does anyone know a simple 
  >>method that works on plating holes in a PCB?  Mike
  > 
  > 
  > I think the best home-brew (closer to professional sho) unit is from 
  > Markus
  > 
  > http://www.myhome.ch/mzingg/pcbstuff/tps/
  > 
  > 
  > Also go back to the posts around 1100, maybe go directly to 1108 and 
  > start reading.   IIRC, there was a detailed list of each step needed.
  > 
  > This is not for the faint of heart nor a simple one shot project.

  This is very true. The electroplating, and application of your own 
  photoresists is the other major parts of the PTH process.

  In addition to etching, and photo imaging, you must;

  1) cleaning PCB surface to prepare for electroplating.
  2) ability to apply your own dry film photoresist
  3) give holes the ability to plate.
  4) setup acid copper electroplating tank with proprietary additives.

  There are several methods of doing (3), such as with carbon dispersion, 
    electroless copper solutions, or with palladium colloid solutions. I 
  believe Markus's setup is using the palladium colloid solutions. All 
  three processes have their problems, and I would say the most critical 
  step in the process.

  Let me know if you have any questions.

  Adam


  Be sure to visit the group home and check for new Bookmarks and files:
  http://groups.yahoo.com/group/Homebrew_PCBs 


        Yahoo! Groups Sponsor 
              ADVERTISEMENT
             
       
       


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  Yahoo! Groups Links

    a.. To visit your group on the web, go to:
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    Homebrew_PCBs-unsubscribe@yahoogroups.com
      
    c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. 



[Non-text portions of this message have been removed]

Jeremy,

1. Where do you buy TSP? I chceked and it is some kind of a cleaner. 
Sounds like a great suggestion. I searched this board and it wasn't 
mentioned before.

2. What do you use for 'activating' the holes, to make the conductive 
so the copper can be later deposited electrochemically?

3. For the others benefit, I am adding this link according to 
Jeremy's suggestion: 

http://www.caswellplating.com/kits/flashcopper.html

Once Jeremy tells us what to use to make the holes conductive, we 
have all crucial details to make plated holes in a homebrew manner, 
right?

Mike


--- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" <jeremy@e...> 
wrote:
> Adam
> Flash copper (Alkaline) works better for me than acid copper. In 
the future you might just want to say "copper plating" leaving "acid" 
out as there is more than one way to plate copper. 
> 
> A quick dip in HOT tsp (tri sodium phosphate) does a great job of 
pre-plate - pre lamination cleaning, and I suspect it would also work 
well for tt (no sandpaper needed)
> 
> JT
> 
>   ----- Original Message ----- 
>   From: Adam Seychell 
>   To: Homebrew_PCBs@yahoogroups.com 
>   Sent: Thursday, July 29, 2004 9:05 PM
>   Subject: Re: [Homebrew_PCBs] Re: Plating thruholes.
> 
> 
>   Dave Mucha wrote:
>   > --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>   > 
>   >>I searched but weren't able to locate any posts on the subject 
but 
>   > 
>   > I 
>   > 
>   >>recall that tehre was a dicussion of it. Does anyone know a 
simple 
>   >>method that works on plating holes in a PCB?  Mike
>   > 
>   > 
>   > I think the best home-brew (closer to professional sho) unit is 
from 
>   > Markus
>   > 
>   > http://www.myhome.ch/mzingg/pcbstuff/tps/
>   > 
>   > 
>   > Also go back to the posts around 1100, maybe go directly to 
1108 and 
>   > start reading.   IIRC, there was a detailed list of each step 
needed.
>   > 
>   > This is not for the faint of heart nor a simple one shot 
project.
> 
>   This is very true. The electroplating, and application of your 
own 
>   photoresists is the other major parts of the PTH process.
> 
>   In addition to etching, and photo imaging, you must;
> 
>   1) cleaning PCB surface to prepare for electroplating.
>   2) ability to apply your own dry film photoresist
>   3) give holes the ability to plate.
>   4) setup acid copper electroplating tank with proprietary 
additives.
> 
>   There are several methods of doing (3), such as with carbon 
dispersion, 
>     electroless copper solutions, or with palladium colloid 
solutions. I 
>   believe Markus's setup is using the palladium colloid solutions. 
All 
>   three processes have their problems, and I would say the most 
critical 
>   step in the process.
> 
>   Let me know if you have any questions.
> 
>   Adam
> 
> 
>   Be sure to visit the group home and check for new Bookmarks and 
files:
>   http://groups.yahoo.com/group/Homebrew_PCBs 
> 
> 
>         Yahoo! Groups Sponsor 
>               ADVERTISEMENT
>              
>        
>        
> 
> 
> --------------------------------------------------------------------
----------
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> 
>     a.. To visit your group on the web, go to:
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>       
>     b.. To unsubscribe from this group, send an email to:
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>       
>     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of 
Service. 

> 
> 
> 
> [Non-text portions of this message have been removed]

> > This is not for the faint of heart nor a simple one shot project.
> 
> This is very true. The electroplating, and application of your own 
> photoresists is the other major parts of the PTH process.
> 
> In addition to etching, and photo imaging, you must;
> 
> 1) cleaning PCB surface to prepare for electroplating.
> 2) ability to apply your own dry film photoresist
> 3) give holes the ability to plate.
> 4) setup acid copper electroplating tank with proprietary additives.
> 
> There are several methods of doing (3), such as with carbon 
dispersion, 
>   electroless copper solutions, or with palladium colloid 
solutions. I 
> believe Markus's setup is using the palladium colloid solutions. 
All 
> three processes have their problems, and I would say the most 
critical 
> step in the process.
> 
> Let me know if you have any questions.
> 
> Adam

I think we have all been looking for a simple way to plate thru-holes.

I know that when I run into this problem, I try to use a resistor or 
some other thru hole part as the connection and then solder both 
sides.

Since most of use use boards that are less than about 6" x 6" the 
size of a tank should not be terribly large.

Any ideas on a a simple way to do plating 

Dave

At 09:05 PM 7/29/2004, mikezcnc wrote:
>Jeremy,
>
>1. Where do you buy TSP?

Most paint stores.  It often goes by its full name: Tri-Sodium Phosphate

dwayne

-- 
Dwayne Reid   <dwayner@...>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax

Celebrating 20 years of Engineering Innovation (1984 - 2004)
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commercial email nor is intended to solicit commercial email.

In a message dated 7/29/2004 10:23:09 PM Central Standard Time, 
dave_mucha@... writes:
Any ideas on a a simple way to do plating 
Dave:  Even IF PTH was no more hassle than etching a single-sided board, if 
one DOES PTH the drilled blank successfully/adequately, THEN the ONLY way to 
apply "resist" is to TIN-PLATE the desired pattern using a "negative" image of 
"plating resist" which exposes only the desired tracks and the "insides" of the 
holes, of course.  Then the tin plating resists the ammonium persulfate etch. 
 

Sad, but MUCH more involved than basic double-sided copper boards!  I tried 
the "electroless tin-plate" one firm (Kepro???) once offered, and it worked, 
but NOT very well, and required pre-heating of the liquid, and it PRECLUDED the 
use of "kitchen utensils" as many of us do, AND, even if done a VERY long 
time, the resulting plating was NOT totally "chemically opaque", so pin-holes 
would result during etching, etc., etc.  Though boards plated with this 
electroless tin stuff DID look much better than corroded ol' brown copper!  So I now 
have any of MY boards done professionally, if I need ten or more of same board, 
or gold fingers, and just "solder both sides" of lead-wires for those holes 
that MUST "go through", or I use eyelets where absolutely necessary.  A pain, 
yes, and not as "neat" as PTH, but what can we do?  PUNT!

Jan Rowland


[Non-text portions of this message have been removed]

I've already told you all, several times. I use the Think and Tinker method, except I substitute Flash copper for acid cooper, and 90/10 tin/lead instead of solder plate.
Otherwise, Ron at think and tinker has done a very good job - and that is where I've learned from , also the Caswell plating manual is useful too. 
These links area already in the links section of this well organized group. 

To put it bluntly - there is no FREE way to do this. You can either buy pre-made chems, or you can spend that amount buying chemicals to mix your own, but either way - you gotta spend some money. - What are pth worth to you? will they make or break your project? Are you just going to send out the boards, Do you want to make commercial grade PCBs for a commercial project at home ? etc...

For those of us doing PTH - I'm curious what your setup cost was?.
Not including imaging, etching , drilling, etc..
Just the PTH plating setup - for me I figure about $700 for ink, plating kit, power regulation, power supply, and optional testing equipment.
 My plating systems are built in to the same table top as my developing, stripping, and etching systems  I can do a max panel size of  6X9.

TSP is found at your average hardware store. - I think the key for using it - is to get it HOT. I use a crock pot. 
JT

  ----- Original Message ----- 
  From: mikezcnc 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Thursday, July 29, 2004 11:05 PM
  Subject: [Homebrew_PCBs] Re: Plating thruholes.


  Jeremy,

  1. Where do you buy TSP? I chceked and it is some kind of a cleaner. 
  Sounds like a great suggestion. I searched this board and it wasn't 
  mentioned before.

  2. What do you use for 'activating' the holes, to make the conductive 
  so the copper can be later deposited electrochemically?

  3. For the others benefit, I am adding this link according to 
  Jeremy's suggestion: 

  http://www.caswellplating.com/kits/flashcopper.html

  Once Jeremy tells us what to use to make the holes conductive, we 
  have all crucial details to make plated holes in a homebrew manner, 
  right?

  Mike


  --- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" <jeremy@e...> 
  wrote:
  > Adam
  > Flash copper (Alkaline) works better for me than acid copper. In 
  the future you might just want to say "copper plating" leaving "acid" 
  out as there is more than one way to plate copper. 
  > 
  > A quick dip in HOT tsp (tri sodium phosphate) does a great job of 
  pre-plate - pre lamination cleaning, and I suspect it would also work 
  well for tt (no sandpaper needed)
  > 
  > JT
  > 
  >   ----- Original Message ----- 
  >   From: Adam Seychell 
  >   To: Homebrew_PCBs@yahoogroups.com 
  >   Sent: Thursday, July 29, 2004 9:05 PM
  >   Subject: Re: [Homebrew_PCBs] Re: Plating thruholes.
  > 
  > 
  >   Dave Mucha wrote:
  >   > --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
  wrote:
  >   > 
  >   >>I searched but weren't able to locate any posts on the subject 
  but 
  >   > 
  >   > I 
  >   > 
  >   >>recall that tehre was a dicussion of it. Does anyone know a 
  simple 
  >   >>method that works on plating holes in a PCB?  Mike
  >   > 
  >   > 
  >   > I think the best home-brew (closer to professional sho) unit is 
  from 
  >   > Markus
  >   > 
  >   > http://www.myhome.ch/mzingg/pcbstuff/tps/
  >   > 
  >   > 
  >   > Also go back to the posts around 1100, maybe go directly to 
  1108 and 
  >   > start reading.   IIRC, there was a detailed list of each step 
  needed.
  >   > 
  >   > This is not for the faint of heart nor a simple one shot 
  project.
  > 
  >   This is very true. The electroplating, and application of your 
  own 
  >   photoresists is the other major parts of the PTH process.
  > 
  >   In addition to etching, and photo imaging, you must;
  > 
  >   1) cleaning PCB surface to prepare for electroplating.
  >   2) ability to apply your own dry film photoresist
  >   3) give holes the ability to plate.
  >   4) setup acid copper electroplating tank with proprietary 
  additives.
  > 
  >   There are several methods of doing (3), such as with carbon 
  dispersion, 
  >     electroless copper solutions, or with palladium colloid 
  solutions. I 
  >   believe Markus's setup is using the palladium colloid solutions. 
  All 
  >   three processes have their problems, and I would say the most 
  critical 
  >   step in the process.
  > 
  >   Let me know if you have any questions.
  > 
  >   Adam
  > 
  > 
  >   Be sure to visit the group home and check for new Bookmarks and 
  files:
  >   http://groups.yahoo.com/group/Homebrew_PCBs 
  > 
  > 
  >         Yahoo! Groups Sponsor 
  >               ADVERTISEMENT
  >              
  >        
  >        
  > 
  > 
  > --------------------------------------------------------------------
  ----------
  >   Yahoo! Groups Links
  > 
  >     a.. To visit your group on the web, go to:
  >     http://groups.yahoo.com/group/Homebrew_PCBs/
  >       
  >     b.. To unsubscribe from this group, send an email to:
  >     Homebrew_PCBs-unsubscribe@yahoogroups.com
  >       
  >     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of 
  Service. 
  > 
  > 
  > 
  > [Non-text portions of this message have been removed]



  Be sure to visit the group home and check for new Bookmarks and files:
  http://groups.yahoo.com/group/Homebrew_PCBs 


        Yahoo! Groups Sponsor 
              ADVERTISEMENT
             
       
       


------------------------------------------------------------------------------
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[Non-text portions of this message have been removed]

Dave Mucha wrote:
>>>This is not for the faint of heart nor a simple one shot project.
>>
>>This is very true. The electroplating, and application of your own 
>>photoresists is the other major parts of the PTH process.
>>
>>In addition to etching, and photo imaging, you must;
>>
>>1) cleaning PCB surface to prepare for electroplating.
>>2) ability to apply your own dry film photoresist
>>3) give holes the ability to plate.
>>4) setup acid copper electroplating tank with proprietary additives.
>>
>>There are several methods of doing (3), such as with carbon 
> 
> dispersion, 
> 
>>  electroless copper solutions, or with palladium colloid 
> 
> solutions. I 
> 
>>believe Markus's setup is using the palladium colloid solutions. 
> 
> All 
> 
>>three processes have their problems, and I would say the most 
> 
> critical 
> 
>>step in the process.
>>
>>Let me know if you have any questions.
>>
>>Adam
> 
> 
> I think we have all been looking for a simple way to plate thru-holes.
> 
> I know that when I run into this problem, I try to use a resistor or 
> some other thru hole part as the connection and then solder both 
> sides.
> 
> Since most of use use boards that are less than about 6" x 6" the 
> size of a tank should not be terribly large.
> 
> Any ideas on a a simple way to do plating 
> 
> Dave

If you want to start copper plating then I suggested go to your local 
electroplating supplier and ask for the chemicals to do it.
There are three parts to the soltuion.
* Sulfuric acid
* copper sulfate
* proprietry organic additives.

The additives must be bought from the company. they might give you a 
free sample if they are in a nice mood. You can plate copper with just 
copper sulfate from the garden store and some sulfuric acid from old car 
batteries, but the plating results will be poor. The additives give 
uniform and smooth deposits. Any old electroplating book will have 
infomation on acid sulfate copper electroplating.
For starters, a "conventional" bath could be made from 150g/L 
CuS04.5H20, and 50g/L H2SO4 without organic additives.

Electroplating is only one stage of the PTH process.

Adam

Jan,

Just a word of comment: I tried the electroless tin and it workd 
exceptionally well on tinning the PCBs. I was quite amazed how well 
it work, exactly in a kitchen and I keep in tee fridge all the time. 
Life of the solution according to a mfr is six months and the cost is 
low for that amount of time.

However, I don't know what the electroless tin does to a hole- that I 
hvent tested but I suspect that unless the hole is copper, than 
nothing. 

It wasn't clear from your post if you were talking about tinning the 
copper traces or tinning the thruholes. For traces to be tinned, the 
solution needs to be hot, otherwise it takes very long time. Mike


--- In Homebrew_PCBs@yahoogroups.com, JanRwl@A... wrote:
> In a message dated 7/29/2004 10:23:09 PM Central Standard Time, 
> dave_mucha@y... writes:
> Any ideas on a a simple way to do plating 
> Dave:  Even IF PTH was no more hassle than etching a single-sided 
board, if 
> one DOES PTH the drilled blank successfully/adequately, THEN the 
ONLY way to 
> apply "resist" is to TIN-PLATE the desired pattern using 
a "negative" image of 
> "plating resist" which exposes only the desired tracks and 
the "insides" of the 
> holes, of course.  Then the tin plating resists the ammonium 
persulfate etch. 
>  
> 
> Sad, but MUCH more involved than basic double-sided copper boards!  
I tried 
> the "electroless tin-plate" one firm (Kepro???) once offered, and 
it worked, 
> but NOT very well, and required pre-heating of the liquid, and it 
PRECLUDED the 
> use of "kitchen utensils" as many of us do, AND, even if done a 
VERY long 
> time, the resulting plating was NOT totally "chemically opaque", so 
pin-holes 
> would result during etching, etc., etc.  Though boards plated with 
this 
> electroless tin stuff DID look much better than corroded ol' brown 
copper!  So I now 
> have any of MY boards done professionally, if I need ten or more of 
same board, 
> or gold fingers, and just "solder both sides" of lead-wires for 
those holes 
> that MUST "go through", or I use eyelets where absolutely 
necessary.  A pain, 

> yes, and not as "neat" as PTH, but what can we do?  PUNT!
> 
> Jan Rowland
> 
> 
> [Non-text portions of this message have been removed]

On Fri, 30 Jul 2004 11:12:19 -0000, mikezcnc <eemikez@...> wrote:

> Jan,
>
> Just a word of comment: I tried the electroless tin and it workd
> exceptionally well on tinning the PCBs. I was quite amazed how well
> it work, exactly in a kitchen and I keep in tee fridge all the time.
> Life of the solution according to a mfr is six months and the cost is
> low for that amount of time.
>
> However, I don't know what the electroless tin does to a hole- that I
> hvent tested but I suspect that unless the hole is copper, than
> nothing.
>
> It wasn't clear from your post if you were talking about tinning the
> copper traces or tinning the thruholes. For traces to be tinned, the
> solution needs to be hot, otherwise it takes very long time. Mike
>
>

The last time i checked all electroless tin used some pretty nasty 
ingredients
which i wouldn't want to have in the kitchen or fridge.
What about yours?

ST

Stefan,

I would like three issues answered by a chemist and or pharmacist 
(although here I suspect that argument would be made that since it is 
used for rubbing then it must be ok:

1. The web search reveals that IPA causes cancer. We might get into 
semantics on that one, but we should not use an argument of rubbing 
alcohol being healthy, therfeore and the reason being that that 
discussion might turn in to medical subject which I won't get into. I 
know it is carcinogennic and if someone believes otherwise, I can 
respect that.

2. Tinnit says: it contains "acidic tin salts, although it 
doesn'tcyanide or other highly poisonous materials it is a skin and 
eye irritant- do not eat or drink". I realize that keeping it in the 
fridge is not for anybody else than me. Fridge is for food only, but 
since it is my fridge then I issued yself a waver from that otherwise 
strict regulation. Now, Stefan, aside how bad that stuff is to our 
helth, you made me think that if it works on copper traces, will 'go 
into the holes'? I would say it will go into the holes ONLY if the 
holes are copper plated.... But for that is the method of using H2S04 
and CuSO4 with DC current or like Jeremy suggested (better yet) 
use 'flash copper' rather than acidic copper... Tinning with that 
stuff brings awsome results, but there are some rather smallish fumes.

3. I would like a chemist to tell us how does IPA clean, because it 
does not dissolve oils nor fats. And if it doesn't then what kind of 
principle is applied for cleaning with it?

Mike


--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> On Fri, 30 Jul 2004 11:12:19 -0000, mikezcnc <eemikez@c...> wrote:
> 
> > Jan,
> >
> > Just a word of comment: I tried the electroless tin and it workd
> > exceptionally well on tinning the PCBs. I was quite amazed how 
well
> > it work, exactly in a kitchen and I keep in tee fridge all the 
time.
> > Life of the solution according to a mfr is six months and the 
cost is
> > low for that amount of time.
> >
> > However, I don't know what the electroless tin does to a hole- 
that I
> > hvent tested but I suspect that unless the hole is copper, than
> > nothing.
> >
> > It wasn't clear from your post if you were talking about tinning 
the
> > copper traces or tinning the thruholes. For traces to be tinned, 
the

> > solution needs to be hot, otherwise it takes very long time. Mike
> >
> >
> 
> The last time i checked all electroless tin used some pretty nasty 
> ingredients
> which i wouldn't want to have in the kitchen or fridge.
> What about yours?
> 
> ST

On Fri, 30 Jul 2004 12:02:03 -0000, mikezcnc <eemikez@...> wrote:

> Stefan,
>
> I would like three issues answered by a chemist and or pharmacist
> (although here I suspect that argument would be made that since it is
> used for rubbing then it must be ok:
>
> 1. The web search reveals that IPA causes cancer.

Where, how? URL please. all three you provided do clearly state
it doesn't!!!!!

> We might get into
> semantics on that one,

No semantics, "no evidence" and "no indication" or similar, there is no 
point
in discussing the semantics, really!

> but we should not use an argument of rubbing
> alcohol being healthy, therfeore and the reason being that that
> discussion might turn in to medical subject which I won't get into. I
> know it is carcinogennic and if someone believes otherwise, I can
> respect that.

The acid in priduction is carcinogenic, not the alcohol. I could not find
the slightest hint suggesting that other than your opinion.

>
> 2. Tinnit says: it contains "acidic tin salts, although it
> doesn'tcyanide or other highly poisonous materials it is a skin and
> eye irritant- do not eat or drink". I realize that keeping it in the
> fridge is not for anybody else than me. Fridge is for food only, but
> since it is my fridge then I issued yself a waver from that otherwise
> strict regulation. Now, Stefan, aside how bad that stuff is to our
> helth, you made me think that if it works on copper traces, will 'go
> into the holes'? I would say it will go into the holes ONLY if the
> holes are copper plated.... But for that is the method of using H2S04
> and CuSO4 with DC current or like Jeremy suggested (better yet)
> use 'flash copper' rather than acidic copper... Tinning with that
> stuff brings awsome results, but there are some rather smallish fumes.

maybe, i dunno.
The last time i looked at flash tin it contained thiourea which is really
carcinogenic (the msds says so).

>
> 3. I would like a chemist to tell us how does IPA clean, because it
> does not dissolve oils nor fats. And if it doesn't then what kind of
> principle is applied for cleaning with it?

I believe it does solve oils and fats.
I'm not sure i admit.

ST

Jeremy,

"...except I substitute Flash copper for acid cooper, and 90/10 
tin/lead instead of solder plate..."  

What does it mean that you substitute 90/10 tin/lead instead of 
solder plate?  Can you elaborate?

Mike




--- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" <jeremy@e...> 
wrote:
> I've already told you all, several times. I use the Think and 
Tinker method, except I substitute Flash copper for acid cooper, and 
90/10 tin/lead instead of solder plate.
> Otherwise, Ron at think and tinker has done a very good job - and 
that is where I've learned from , also the Caswell plating manual is 
useful too. 
> These links area already in the links section of this well 
organized group. 
> 
> To put it bluntly - there is no FREE way to do this. You can either 
buy pre-made chems, or you can spend that amount buying chemicals to 
mix your own, but either way - you gotta spend some money. - What are 
pth worth to you? will they make or break your project? Are you just 
going to send out the boards, Do you want to make commercial grade 
PCBs for a commercial project at home ? etc...
> 
> For those of us doing PTH - I'm curious what your setup cost was?.
> Not including imaging, etching , drilling, etc..
> Just the PTH plating setup - for me I figure about $700 for ink, 
plating kit, power regulation, power supply, and optional testing 
equipment.
>  My plating systems are built in to the same table top as my 
developing, stripping, and etching systems  I can do a max panel size 
of  6X9.
> 
> TSP is found at your average hardware store. - I think the key for 
using it - is to get it HOT. I use a crock pot. 
> JT
> 
> 
>   ----- Original Message ----- 
>   From: mikezcnc 
>   To: Homebrew_PCBs@yahoogroups.com 
>   Sent: Thursday, July 29, 2004 11:05 PM
>   Subject: [Homebrew_PCBs] Re: Plating thruholes.
> 
> 
>   Jeremy,
> 
>   1. Where do you buy TSP? I chceked and it is some kind of a 
cleaner. 
>   Sounds like a great suggestion. I searched this board and it 
wasn't 
>   mentioned before.
> 
>   2. What do you use for 'activating' the holes, to make the 
conductive 
>   so the copper can be later deposited electrochemically?
> 
>   3. For the others benefit, I am adding this link according to 
>   Jeremy's suggestion: 
> 
>   http://www.caswellplating.com/kits/flashcopper.html
> 
>   Once Jeremy tells us what to use to make the holes conductive, we 
>   have all crucial details to make plated holes in a homebrew 
manner, 
>   right?
> 
>   Mike
> 
> 
>   --- In Homebrew_PCBs@yahoogroups.com, "Jeremy Taylor" 
<jeremy@e...> 
>   wrote:
>   > Adam
>   > Flash copper (Alkaline) works better for me than acid copper. 
In 
>   the future you might just want to say "copper plating" 
leaving "acid" 
>   out as there is more than one way to plate copper. 
>   > 
>   > A quick dip in HOT tsp (tri sodium phosphate) does a great job 
of 
>   pre-plate - pre lamination cleaning, and I suspect it would also 
work 
>   well for tt (no sandpaper needed)
>   > 
>   > JT
>   > 
>   >   ----- Original Message ----- 
>   >   From: Adam Seychell 
>   >   To: Homebrew_PCBs@yahoogroups.com 
>   >   Sent: Thursday, July 29, 2004 9:05 PM
>   >   Subject: Re: [Homebrew_PCBs] Re: Plating thruholes.
>   > 
>   > 
>   >   Dave Mucha wrote:
>   >   > --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" 
<eemikez@c...> 
>   wrote:
>   >   > 
>   >   >>I searched but weren't able to locate any posts on the 
subject 
>   but 
>   >   > 
>   >   > I 
>   >   > 
>   >   >>recall that tehre was a dicussion of it. Does anyone know a 
>   simple 
>   >   >>method that works on plating holes in a PCB?  Mike
>   >   > 
>   >   > 
>   >   > I think the best home-brew (closer to professional sho) 
unit is 
>   from 
>   >   > Markus
>   >   > 
>   >   > http://www.myhome.ch/mzingg/pcbstuff/tps/
>   >   > 
>   >   > 
>   >   > Also go back to the posts around 1100, maybe go directly to 
>   1108 and 
>   >   > start reading.   IIRC, there was a detailed list of each 
step 
>   needed.
>   >   > 
>   >   > This is not for the faint of heart nor a simple one shot 
>   project.
>   > 
>   >   This is very true. The electroplating, and application of 
your 
>   own 
>   >   photoresists is the other major parts of the PTH process.
>   > 
>   >   In addition to etching, and photo imaging, you must;
>   > 
>   >   1) cleaning PCB surface to prepare for electroplating.
>   >   2) ability to apply your own dry film photoresist
>   >   3) give holes the ability to plate.
>   >   4) setup acid copper electroplating tank with proprietary 
>   additives.
>   > 
>   >   There are several methods of doing (3), such as with carbon 
>   dispersion, 
>   >     electroless copper solutions, or with palladium colloid 
>   solutions. I 
>   >   believe Markus's setup is using the palladium colloid 
solutions. 
>   All 
>   >   three processes have their problems, and I would say the most 
>   critical 
>   >   step in the process.
>   > 
>   >   Let me know if you have any questions.
>   > 
>   >   Adam
>   > 
>   > 
>   >   Be sure to visit the group home and check for new Bookmarks 
and 
>   files:
>   >   http://groups.yahoo.com/group/Homebrew_PCBs 
>   > 
>   > 
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>   > 
>   > 
>   > [Non-text portions of this message have been removed]
> 
> 
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> 
> 
> 
> [Non-text portions of this message have been removed]

> 3. I would like a chemist to tell us how does IPA clean, because it 
> does not dissolve oils nor fats. And if it doesn't then what kind 
of 
> principle is applied for cleaning with it?
> 
> Mike


http://scifun.chem.wisc.edu/chemweek/FatsOils/Fats&Oils.html

That's funny, Dave.

Mike

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...> 
wrote:
>  
> > 3. I would like a chemist to tell us how does IPA clean, because 
it 

> > does not dissolve oils nor fats. And if it doesn't then what kind 
> of 
> > principle is applied for cleaning with it?
> > 
> > Mike
> 
> 
> http://scifun.chem.wisc.edu/chemweek/FatsOils/Fats&Oils.html

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> That's funny, Dave.

You asked for some of the science behind how IPA alchol ( C3H8O ) and 
lipds ( C3H5O3+C3 with double bonds of O and 3 fatty acids ) interact.

That page offered some of the molecular structure behind the lipids.

It may not explain it all, but it does offer the basis of how IPA 
will act as a solvent.

Dave




> 
> Mike
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" 
<dave_mucha@y...> 
> wrote:
> >  
> > > 3. I would like a chemist to tell us how does IPA clean, 
because 
> it 
> > > does not dissolve oils nor fats. And if it doesn't then what 
kind 

> > of 
> > > principle is applied for cleaning with it?
> > > 
> > > Mike
> > 
> > 
> > http://scifun.chem.wisc.edu/chemweek/FatsOils/Fats&Oils.html

In a message dated 7/30/2004 6:49:38 AM Central Standard Time, 
eemikez@... writes:
It wasn't clear from your post if you were talking about tinning the 
copper traces or tinning the thruholes. For traces to be tinned, the 
solution needs to be hot, otherwise it takes very long time. Mike
Yes, there must FIRST be good copper PTH "IN there"!  Then the PC-pattern is 
"tin-plated".  The tin-plate also plates INSIDE the holes, of course!  The 
etchant then will attack only the bare copper, NOT the tin.  After all undesired 
copper is gone, I understand the boards are heated under IR lamps, etc, to 
"reflow" the tin-plate, leaving a nice shiny "solder plating" where you have no 
green "solder mask" (a kind of high-q. epoxy-paint).  Jan R.


[Non-text portions of this message have been removed]

In a message dated 7/30/2004 6:54:31 AM Central Standard Time, 
stefan_trethan@... writes:
The last time i checked all electroless tin used some pretty nasty 
ingredients which i wouldn't want to have in the kitchen or fridge.  What about yours?<<
Yeah, I seem to recall this.  Things like Stannous cyanide, wasn't it?  I'm 
no chemist, so I don't "memorize" such on one-sight.    The batch I had bought 
got used, and remainder "went bad" before I ever even HAD the thought of 
sprinkling it over my ice-cream, and it had been SO much hassle for the two PCB's a 
year, I just FORGOT abowdit!


[Non-text portions of this message have been removed]

A member of another mailing list I am a member of
found the following in a archive. Further, he tested
and it worked as advertised:

I have been dealing with a development effort for a
circuit that my company is developing. In order to get
fast turnaround of boards for testing, I needed a way
to make high quality circuit boards (multilayer) in
under 8 hours. Cost from commercial board houses for
24 hour turnaround was in the range of $2000-$3000 per
design.  In my case, I had to also develope plating
systems and through-hole activation, fast etching, and
a hot 20 ton press which I built by converting a shop
press from harbor freight and adding a temperature
controller and heating elements.  etc.

For ATM purposes, 2 sided boards can be made for a
minimal expense.

Because many on this list make their own circuit
boards on occassion (for stepper circuits and camera
circuits), I thought I would share my experience
with the group.

I am currently producing 4, 6 and 8 layer circuit
boards using equipment now in my basement. Granted my
basement looks like a chamber of horrors, but I
suspect this is true for many on this list. Eight mil
traces and lands are now easily doable and I am
holding +/- 2 mil registration.

The greatest roadblock to producing good circuit
boards was getting good artwork on a transparency.  In
that regard, I have made several discoveries which are
not immediately intuitive.

First, getting really good artwork for the spec above
is not possible with a laser printer. Phase error
creeps in and even for printers claiming 1200
DPI the accuracy just isn't there.  I tested this with
several models of HP printers including the 2000
series and the 4000 series.

In addition, the toner is just not dark enough.  You
end up having to underexpose the photoresist in order
to get good removal and then you have a problem with
undercured photoresist that will not tent over holes
and whose sides are weak. Further the developing
process just trashes the underexposed resist.

I finally decided to try an inkjet printer.  After
some research looking for a printer that supported
high resolution in black, I purchased a Canon.
Initially, I purchased the S300 but it turned out that
clever marketing made is sound like it supported high
res black.  In reality, the black was only 600 DPI
like every other printer...  Not enough resolution.  I
then tried the S800, which did support 2400 x 1200 DPI
in color and in Black - the only printer that
supported high resolution black printing. Experiments
with
this printer unfortunately revealed the problem that
most people have with bubble jets.  The black is
simply not dark enough in UV.  This despite the fact
that it was a pigment based ink.

I did have moderate success stacking tranparenies. 
This allowed me to increase the exposure time, but
because only the first transparency was ink down (the
second had to have a full 5 mil separation for the
thickness of the first transparency, the edges were
not very clean.

I then had a brainstorm, I realized that my UV filters
for my flourescent lighting were amber.  I decided to
try other colors... I quickly discovered that yellow
was just as dark (in UV) as black. Disappointed that
it was not darker, I began thinking about ways I could
change the formulation of the ink to include a
coreactive UV blocking chemical. I started searching
the net when I discovered that ink fading as a result
of UV is a real problem for photography. To my
surprise, my printer already contained an ink that
was UV blocking.  All I had to do was tell the printer
that it was printing on high resolution photopaper. 
This automatically switched cartridges to the PC
(Photo Cyan) and PM (Photomagenta). Yellow remains the
same because yellow only fades to yellow.

In any case, once I did that, I was able to fully
expose the Photoresist. In comparing a foil blocked
section and a photo ink exposed section there
was little difference. Moreover, in testing artwork
created by a real photoplotter (costing $200,000). 
There was no difference. The only difference was that
I settled on "GREEN" as being the color that was best.
This selected the darkness of yellow in UV and the
chemical UV blocking in Photo Cyan to produce a very
dark black in UV and a pretty green in visible... :-)

Perfect exposures!  That along with unbelievable
resolution of these printers make for a killer
combination for producing your own artwork and
consequently your own circuit boards.

The bottom line is this. You DON'T want a printer with
a dark black! Forget whether it is pigment based ink
or dye based ink. That is all irrelavent, none of them
are going to be dark enough.

You want a PHOTO printer with PHOTO ink.  Further ALL
photoprinters have high resolution in color!  Even the
cheap ones ($100)! Just make sure a photo ink is
available either from the manufacturer or for an ink
refiller. All photo ink is, is ink with UV blocking
added so the photos you print don't fade.

What will the photoplotter companies do???

Armed with this information, there is no reason
everyone on this list does not do steves killer mod
for the Philips Vesta camera or the many circuits
for telescope motorization and tracking.


Best

Marvin Dickens
Alpharetta, Georgia

=====
Registered Linux User No. 80253
If you use linux, get counted at: 
http://www.linuxcounter.org


		
__________________________________
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Very interesting. - And good advice for DIY Uv'ers - but...

One thing the Photoploter companies will do - Is still make photplots , cause no inkjet can do 1/8th, - 1./48th of a mil in perfect registration.  I personally have specs between traces that are somewhere between 3 and 4 mil

I can take a hotpot, put it on a board and exposes it for hours, and none of the uv leaks through. 

S800 is out of production, (original ink kit from cannon is $149) I'm not sure how many 8X10 negatives one tank full of ink can print, but that's the cost equivalent of 21 8X10 1/8 mil photplots. 

If the guy had compared the inkjet to a $20,000 photplot with 4000dpi) and came to the same conclusion, I would take his word a little bit more seriously, but claiming an inkjet is on the same plane as a $200,000 ( talking 1um resolution here) , I cant take it to heart , but that said, - I'll probably go inkjet shopping tonight. 

JT

  ----- Original Message ----- 
  From: mpdickens 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Friday, July 30, 2004 5:52 PM
  Subject: [Homebrew_PCBs] Inkjet printers, transparencies and UV light...


  A member of another mailing list I am a member of
  found the following in a archive. Further, he tested
  and it worked as advertised:

  I have been dealing with a development effort for a
  circuit that my company is developing. In order to get
  fast turnaround of boards for testing, I needed a way
  to make high quality circuit boards (multilayer) in
  under 8 hours. Cost from commercial board houses for
  24 hour turnaround was in the range of $2000-$3000 per
  design.  In my case, I had to also develope plating
  systems and through-hole activation, fast etching, and
  a hot 20 ton press which I built by converting a shop
  press from harbor freight and adding a temperature
  controller and heating elements.  etc.

  For ATM purposes, 2 sided boards can be made for a
  minimal expense.

  Because many on this list make their own circuit
  boards on occassion (for stepper circuits and camera
  circuits), I thought I would share my experience
  with the group.

  I am currently producing 4, 6 and 8 layer circuit
  boards using equipment now in my basement. Granted my
  basement looks like a chamber of horrors, but I
  suspect this is true for many on this list. Eight mil
  traces and lands are now easily doable and I am
  holding +/- 2 mil registration.

  The greatest roadblock to producing good circuit
  boards was getting good artwork on a transparency.  In
  that regard, I have made several discoveries which are
  not immediately intuitive.

  First, getting really good artwork for the spec above
  is not possible with a laser printer. Phase error
  creeps in and even for printers claiming 1200
  DPI the accuracy just isn't there.  I tested this with
  several models of HP printers including the 2000
  series and the 4000 series.

  In addition, the toner is just not dark enough.  You
  end up having to underexpose the photoresist in order
  to get good removal and then you have a problem with
  undercured photoresist that will not tent over holes
  and whose sides are weak. Further the developing
  process just trashes the underexposed resist.

  I finally decided to try an inkjet printer.  After
  some research looking for a printer that supported
  high resolution in black, I purchased a Canon.
  Initially, I purchased the S300 but it turned out that
  clever marketing made is sound like it supported high
  res black.  In reality, the black was only 600 DPI
  like every other printer...  Not enough resolution.  I
  then tried the S800, which did support 2400 x 1200 DPI
  in color and in Black - the only printer that
  supported high resolution black printing. Experiments
  with
  this printer unfortunately revealed the problem that
  most people have with bubble jets.  The black is
  simply not dark enough in UV.  This despite the fact
  that it was a pigment based ink.

  I did have moderate success stacking tranparenies. 
  This allowed me to increase the exposure time, but
  because only the first transparency was ink down (the
  second had to have a full 5 mil separation for the
  thickness of the first transparency, the edges were
  not very clean.

  I then had a brainstorm, I realized that my UV filters
  for my flourescent lighting were amber.  I decided to
  try other colors... I quickly discovered that yellow
  was just as dark (in UV) as black. Disappointed that
  it was not darker, I began thinking about ways I could
  change the formulation of the ink to include a
  coreactive UV blocking chemical. I started searching
  the net when I discovered that ink fading as a result
  of UV is a real problem for photography. To my
  surprise, my printer already contained an ink that
  was UV blocking.  All I had to do was tell the printer
  that it was printing on high resolution photopaper. 
  This automatically switched cartridges to the PC
  (Photo Cyan) and PM (Photomagenta). Yellow remains the
  same because yellow only fades to yellow.

  In any case, once I did that, I was able to fully
  expose the Photoresist. In comparing a foil blocked
  section and a photo ink exposed section there
  was little difference. Moreover, in testing artwork
  created by a real photoplotter (costing $200,000). 
  There was no difference. The only difference was that
  I settled on "GREEN" as being the color that was best.
  This selected the darkness of yellow in UV and the
  chemical UV blocking in Photo Cyan to produce a very
  dark black in UV and a pretty green in visible... :-)

  Perfect exposures!  That along with unbelievable
  resolution of these printers make for a killer
  combination for producing your own artwork and
  consequently your own circuit boards.

  The bottom line is this. You DON'T want a printer with
  a dark black! Forget whether it is pigment based ink
  or dye based ink. That is all irrelavent, none of them
  are going to be dark enough.

  You want a PHOTO printer with PHOTO ink.  Further ALL
  photoprinters have high resolution in color!  Even the
  cheap ones ($100)! Just make sure a photo ink is
  available either from the manufacturer or for an ink
  refiller. All photo ink is, is ink with UV blocking
  added so the photos you print don't fade.

  What will the photoplotter companies do???

  Armed with this information, there is no reason
  everyone on this list does not do steves killer mod
  for the Philips Vesta camera or the many circuits
  for telescope motorization and tracking.


  Best

  Marvin Dickens
  Alpharetta, Georgia

  =====
  Registered Linux User No. 80253
  If you use linux, get counted at: 
  http://www.linuxcounter.org


              
  __________________________________
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  Yahoo! Mail - 50x more storage than other providers!
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[Non-text portions of this message have been removed]

The black ink in my old Epson 660 is extremely UV blocking. I can expose 
a PCB over 5 times normal and still not manage to effect the dark areas. 
The problem of exposing his length of time is that thin traces become a 
too narrow. The Epson 600 black ink (dye based) looks deep red through a 
bright white light. I have just recently tried my ($100) Cannon S300 but 
with Calidad black ink refill.  I have made one PCB so far, but not 
measured it's UV blocking ability. Also in the driver settings, 
selecting a media for a Photo paper then the printer mixes color inks 
with the back ink.
Have you looked at the transparencies under a microscope ?

Does the 1200x2400 dpi printing really show up sharper than 600dpi 
printing from the Cannon S300 printer ? I found the line edge jaggedness 
from inkjet printers, renders resolutions above 1000dpi meaningless.




mpdickens wrote:

> A member of another mailing list I am a member of
> found the following in a archive. Further, he tested
> and it worked as advertised:
> 
> I have been dealing with a development effort for a
> circuit that my company is developing. In order to get
> fast turnaround of boards for testing, I needed a way
> to make high quality circuit boards (multilayer) in
> under 8 hours. Cost from commercial board houses for
> 24 hour turnaround was in the range of $2000-$3000 per
> design.  In my case, I had to also develope plating
> systems and through-hole activation, fast etching, and
> a hot 20 ton press which I built by converting a shop
> press from harbor freight and adding a temperature
> controller and heating elements.  etc.
> 
> For ATM purposes, 2 sided boards can be made for a
> minimal expense.
> 
> Because many on this list make their own circuit
> boards on occassion (for stepper circuits and camera
> circuits), I thought I would share my experience
> with the group.
> 
> I am currently producing 4, 6 and 8 layer circuit
> boards using equipment now in my basement. Granted my
> basement looks like a chamber of horrors, but I
> suspect this is true for many on this list. Eight mil
> traces and lands are now easily doable and I am
> holding +/- 2 mil registration.
> 
> The greatest roadblock to producing good circuit
> boards was getting good artwork on a transparency.  In
> that regard, I have made several discoveries which are
> not immediately intuitive.
> 
> First, getting really good artwork for the spec above
> is not possible with a laser printer. Phase error
> creeps in and even for printers claiming 1200
> DPI the accuracy just isn't there.  I tested this with
> several models of HP printers including the 2000
> series and the 4000 series.
> 
> In addition, the toner is just not dark enough.  You
> end up having to underexpose the photoresist in order
> to get good removal and then you have a problem with
> undercured photoresist that will not tent over holes
> and whose sides are weak. Further the developing
> process just trashes the underexposed resist.
> 
> I finally decided to try an inkjet printer.  After
> some research looking for a printer that supported
> high resolution in black, I purchased a Canon.
> Initially, I purchased the S300 but it turned out that
> clever marketing made is sound like it supported high
> res black.  In reality, the black was only 600 DPI
> like every other printer...  Not enough resolution.  I
> then tried the S800, which did support 2400 x 1200 DPI
> in color and in Black - the only printer that
> supported high resolution black printing. Experiments
> with
> this printer unfortunately revealed the problem that
> most people have with bubble jets.  The black is
> simply not dark enough in UV.  This despite the fact
> that it was a pigment based ink.
> 
> I did have moderate success stacking tranparenies. 
> This allowed me to increase the exposure time, but
> because only the first transparency was ink down (the
> second had to have a full 5 mil separation for the
> thickness of the first transparency, the edges were
> not very clean.
> 
> I then had a brainstorm, I realized that my UV filters
> for my flourescent lighting were amber.  I decided to
> try other colors... I quickly discovered that yellow
> was just as dark (in UV) as black. Disappointed that
> it was not darker, I began thinking about ways I could
> change the formulation of the ink to include a
> coreactive UV blocking chemical. I started searching
> the net when I discovered that ink fading as a result
> of UV is a real problem for photography. To my
> surprise, my printer already contained an ink that
> was UV blocking.  All I had to do was tell the printer
> that it was printing on high resolution photopaper. 
> This automatically switched cartridges to the PC
> (Photo Cyan) and PM (Photomagenta). Yellow remains the
> same because yellow only fades to yellow.
> 
> In any case, once I did that, I was able to fully
> expose the Photoresist. In comparing a foil blocked
> section and a photo ink exposed section there
> was little difference. Moreover, in testing artwork
> created by a real photoplotter (costing $200,000). 
> There was no difference. The only difference was that
> I settled on "GREEN" as being the color that was best.
> This selected the darkness of yellow in UV and the
> chemical UV blocking in Photo Cyan to produce a very
> dark black in UV and a pretty green in visible... :-)
> 
> Perfect exposures!  That along with unbelievable
> resolution of these printers make for a killer
> combination for producing your own artwork and
> consequently your own circuit boards.
> 
> The bottom line is this. You DON'T want a printer with
> a dark black! Forget whether it is pigment based ink
> or dye based ink. That is all irrelavent, none of them
> are going to be dark enough.
> 
> You want a PHOTO printer with PHOTO ink.  Further ALL
> photoprinters have high resolution in color!  Even the
> cheap ones ($100)! Just make sure a photo ink is
> available either from the manufacturer or for an ink
> refiller. All photo ink is, is ink with UV blocking
> added so the photos you print don't fade.
> 
> What will the photoplotter companies do???
> 
> Armed with this information, there is no reason
> everyone on this list does not do steves killer mod
> for the Philips Vesta camera or the many circuits
> for telescope motorization and tracking.
> 
> 
> Best
> 
> Marvin Dickens

--- Adam Seychell <a_seychell@...> wrote:

> The black ink in my old Epson 660 is extremely UV
> blocking. I can expose a PCB over 5 times normal and
> still not manage to effect the dark areas.

Well, I'm no expert in the area of optical physics. 

So, I intend to make a test transparency that is
composed of the same test pattern repeated several
times using  different colors. Then I'm going to use
it to make a test board. My reasoning behind this is
simple: Even if I knew a lot about optics (Which I
don't), without knowing the exact chemical
compositions of the ink I use along with a detailed
description of the physical characteristics of the
photo resist that I use, I'd only be making
conjectures regarding the results as reported by the
original author of the email. 

Further, the information that I gather from this
experiment will likely only be applicable the the ink
I am using and the photo resist I am using. Different
inks and photo resists could possibly give different
results.

Also, the results that he described could be explained
totally by the chemical makeup of the ink: Perhaps the
chemical composition of the color of ink that he used
is less prone to having a jagged meniscus (In other
words, a very smooth and symetric meniscus) between
the ink and the transparency.

OTOH, this may be a total load of bullsh!t and a waste
of my time. I'll let you know...


Best

Marvin Dickens

=====
Registered Linux User No. 80253
If you use linux, get counted at: 
http://www.linuxcounter.org


		
__________________________________
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
http://promotions.yahoo.com/new_mail

mpdickens wrote:
> --- Adam Seychell <a_seychell@...> wrote:
> 
> 
>>The black ink in my old Epson 660 is extremely UV
>>blocking. I can expose a PCB over 5 times normal and
>>still not manage to effect the dark areas.
> 
> 
> Well, I'm no expert in the area of optical physics. 
> 
[deleted]>
> OTOH, this may be a total load of bullsh!t and a waste
> of my time. I'll let you know...
> 
> 

I have also looked at available inkjet resolutions because I'm very 
interested in how fine detail photomask you can get from a inkjet. The 
two printers I've tried (Epson 660, Cannon S330) can do 0.25mm (10 mils) 
trace/space widths.
Most new photo printers do 1200dpi+ on both axis, It would be 
interesting to compare the Cannon i560 (4800x1200dpi) with the S330 I 
currently own. Are the pigment based inks are darker ?
It seems that both Epson and Cannon are changing to pigment black inks 
on their photo inkjet printers.

Hello everyone,
 This is my first post to this great group. I meant to reply to this
sooner, but just didn't get a round tuit. :) Before anyone asks you to
believe chemical exposures (other than chronic occupational
overexposures) cause cancers, please first consider the latest
clinical findings by scientistss invloved in cancer research, not
toxicologists or environmentalists. The findings of the latter two
academicians must be understood within the context of the metrics they
use to rate carcinogenicity, metrics which leading cancer researchers
have recently denounced as false and worthless. The metrics, such as
the Ames Assay, were once believed accurate, but now it seems clear
were based on false assumptions about thresholds of exposures and
confounded further by the lack of proper exposure control groups when
these metrics were originally postulated.
 There is always a lapse of time, usually measured in years, between
laboratory research and implementation in the legal/regulatory world.
This is further confounded by the current popular thought on this
subject, shaped as it is by 30 odd years of drumming into our
collective conciousness the mantra: "Kemicalzs Kauzes Kancer". But
when the very scientists who once warned us thusly now say "It just
isn't so", and when the leading advocate of this new thinking on
cancer and chemicals is no less than the world's most published
scientist and currently one of the world's leading cancer researchers,
THEN you can believe it!

http://europa.eu.int/comm/environment/ppps/ma_reding_annex2.pdf

 Just use common sense and practice standard industrial hygene: limit
exposure with appropriate clothing and practices, and wash of
accidental exposures without delay, and then QUIT WORRYING!

Jimbo

P.S.

If the IPA/cancer link were really plausible would'nt millions of
people be at serious risk since IPA is used by the drum as a
medicinal/theraputic topical? Wouldn't those areas of the body so
chronically exposed then become predominant tumor sites? NO such link
has ever been documented. Many people have suffered acute toxicity
(poisoning)from overexposure to IPA in theraputic contexts, but no
suspect cancers were reported.

From OSHA:

Epidemiological studies suggested an association between isopropyl
alcohol and paranasal sinus cancer; however, subsequent analysis
suggests that the "strong-acid" process used to manufacture isopropyl
alcohol may be responsible for these cancers [ACGIH 1991]. The
International Agency for Research on Cancer has concluded that the
evidence for the carcinogenicity of this process is adequate but that
the evidence for isopropyl alcohol itself is inadequate [IARC 1987].



--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> Stefan,
> 
> I would like three issues answered by a chemist and or pharmacist 
> (although here I suspect that argument would be made that since it
is 
> used for rubbing then it must be ok:
> 
> 1. The web search reveals that IPA causes cancer. We might get into 
> semantics on that one, but we should not use an argument of rubbing 
> alcohol being healthy, therfeore and the reason being that that 
> discussion might turn in to medical subject which I won't get into.
I 
> know it is carcinogennic and if someone believes otherwise, I can 
> respect that.

Jimbo,

i thank you for replying but in the future when steve the moderator
closes a topic you better do what he says.

ST

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
> Jimbo,
> 
> i thank you for replying but in the future when steve the moderator
> closes a topic you better do what he says.

Then if Steve asks you to stop playing webcop, shouldn't you listen?

;')

Steve, the listowner

I read it, guys. No comment.  Mike


--- In Homebrew_PCBs@yahoogroups.com, "Steve" <alienrelics@y...> 
wrote:
> --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
> <stefan_trethan@g...> wrote:
> > Jimbo,
> > 
> > i thank you for replying but in the future when steve the 
moderator

> > closes a topic you better do what he says.
> 
> Then if Steve asks you to stop playing webcop, shouldn't you listen?
> 
> ;')
> 
> Steve, the listowner

On Wed, 04 Aug 2004 02:31:08 -0000, Steve <alienrelics@...> wrote:

> --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
> <stefan_trethan@g...> wrote:
>> Jimbo,
>>
>> i thank you for replying but in the future when steve the moderator
>> closes a topic you better do what he says.
>
> Then if Steve asks you to stop playing webcop, shouldn't you listen?
>
> ;')
>
> Steve, the listowner

You can hardly stop me suggesting things ;-)

ST

while steve is pretty reasonable, I wouldn't go challenging him.  Mod 
is God...

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> On Wed, 04 Aug 2004 02:31:08 -0000, Steve <alienrelics@y...> wrote:
> 
> > --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
> > <stefan_trethan@g...> wrote:
> >> Jimbo,
> >>
> >> i thank you for replying but in the future when steve the 
moderator
> >> closes a topic you better do what he says.
> >
> > Then if Steve asks you to stop playing webcop, shouldn't you 
listen?

> >
> > ;')
> >
> > Steve, the listowner
> 
> You can hardly stop me suggesting things ;-)
> 
> ST

On Wed, 04 Aug 2004 05:55:15 -0000, Phil <phil1960us@...> wrote:

> while steve is pretty reasonable, I wouldn't go challenging him.  Mod
> is God...

And he is the owner too :-) some sort of super-god.
Nah i don' think he's goin to kick my ass outa' here.
If he wants having me contribute to the discussion he must endure
my comments from time to time. If i find something out of order
i will say so, nothing wrong with that. Everyone seems to ignore
me anyway as they know i can't do a thing.


ST

Hi,

i was wondering if there is a tutorial for advanced routing.
I mean as soon as you have two layers and more than 100components
it starts to get more difficult.
If there is no tutorial we could maybe exchange some tricks.

How do you start?
How do you decide which parts are on which side?
(i put the SMD ones on top which can be connected to throughhole without
adding a via, and i aim for the same population density top and bottom.)

Often it is required to rotate and rearrange parts to get a good layout,
but at a certain number of parts it is very hard to keep track of things.

Do you start routing with special nets, like supply?

You see, the methods i used for years on smaller circuits seem very, very 
hard
to apply to bigger circuits, and i believe there must be some tricks i 
don't
know yet.
Maybe if everyone throws in a few ideas we can all learn something.

I always use different color "rubber bands" for GND and VCC which helps a 
bit.

ST

----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, August 04, 2004 9:35 AM
Subject: [Homebrew_PCBs] advanced routing


> Hi,
>
> i was wondering if there is a tutorial for advanced routing.
> I mean as soon as you have two layers and more than 100components
> it starts to get more difficult.
> If there is no tutorial we could maybe exchange some tricks.

I've looked and I don't think there is one.

Here are a few 'rules of thumb' I've come across which I find very useful:

>
> How do you start?

Start placement with the largest parts.

> How do you decide which parts are on which side?

> (i put the SMD ones on top which can be connected to throughhole without
> adding a via, and i aim for the same population density top and bottom.)

For low-cost manufacture it's best to put all the SMDs on the top. If you
put them on top and bottom your technique seems OK.

>
> Often it is required to rotate and rearrange parts to get a good layout,
> but at a certain number of parts it is very hard to keep track of things.

Try to keep the components in functional blocks, like in the schematic. An
autorouter can be useful, even if you are routing manually, to show where
there are going to be problems. If you are using an autorouter, here are
some tips:

http://www.connecteda.com/doc/Autorouting%20Techniques.pdf

They are applicable to any autorouter. BTW, that Electra autorouter is
*very* good, it's now supplied with the Pulsonix software I use.

>
> Do you start routing with special nets, like supply?

Critical nets like power and ground, and clocks, etc. should always be
routed first.

>
> You see, the methods i used for years on smaller circuits seem very, very
> hard
> to apply to bigger circuits, and i believe there must be some tricks i
> don't
> know yet.
> Maybe if everyone throws in a few ideas we can all learn something.

Placement is the important thing, once that is optimised the actual routing
should be quite easy, until you get to the last few tracks - they will take
as long as all the others put together. 8-)

Always start by routing the shortest tracks, working up to the longest. That
is probably the most important rule.


> I always use different color "rubber bands" for GND and VCC which helps a
> bit.

That can help a lot. The software I use highlights an entire net when it is
selected. I can use different colours for different nets, as well.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller

Hi Stefan

When I routed boards at work a couple of years ago I often made 2-layer 
boards with the classic vertical traces at one side and horizontal at 
the other. 

I used to start routing the Power and Gnd , then I routed important 
signals manually .

Then I locked that traces and used the autorouter for the remaining.

After that came the part when you fix the traces not solved and final 
touch up. 

Last we often placed a Gnd area to fill up all unused areas of the 
board.


// Gunnar Lestander , SM4VLM

On Wed, 4 Aug 2004 12:48:53 +0200 (CEST), Gunnar Lestander 
<gunnar@...> wrote:

> Hi Stefan
>
> When I routed boards at work a couple of years ago I often made 2-layer
> boards with the classic vertical traces at one side and horizontal at
> the other.
>
> I used to start routing the Power and Gnd , then I routed important
> signals manually .
>
> Then I locked that traces and used the autorouter for the remaining.
>
> After that came the part when you fix the traces not solved and final
> touch up.
>
> Last we often placed a Gnd area to fill up all unused areas of the
> board.
>
>
> // Gunnar Lestander , SM4VLM
>

I know that approach, but it leads to a lot of vias, which i don't want to 
solder.
Also it seems to work better with throughhole and less good with hybrid 
boards.

thanks

ST

> I know that approach, but it leads to a lot of vias, which i don't 
>want tosolder.
 
> Also it seems to work better with throughhole and less good with 
>hybrid boards.

When you send it for manufacturing the vias are no problem.
Actually I've heard that more vias is preferred before less, since the 
forces in vias during tempurature changes can break the via.

For the Midnight Board Maker each via represent a problem so the less 
the merrier... 

Gunnar Lestander 





- - - - - - - - - - - - - - - - - - - 


Gunnar Lestander 
\ufffdnglyckan
694 93  \ufffdstansj\ufffd
mailto:sm4vlm@...
hem 0582 526 93
mob 073 96 93 916

- - - - - - - - - - - - - - - - - - - -

> For the Midnight Board Maker each via represent a problem so the less
> the merrier...
>
> Gunnar Lestander


Well, i'm one of those...

ST

> That can help a lot. The software I use highlights an entire net when it
is
> selected. I can use different colours for different nets, as well.

    Leon, can you say more about the software you use, and how it compares
to Protel?

    Thanks,
    Alexandre Souza


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jimbo_1490 wrote:

[removed text]
> 
> http://europa.eu.int/comm/environment/ppps/ma_reding_annex2.pdf

Very interesting article. It seems from reading the article that testing 
what chemicals are and are not carcinogenic is going to take a lot more 
time and effort (i.e $$$) than before.

> 
>  Just use common sense and practice standard industrial hygene: limit
> exposure with appropriate clothing and practices, and wash of
> accidental exposures without delay, and then QUIT WORRYING!

Advice taken.

Hi List.
Any idea where to find free or cheap Standalone Milling Isolation Software, 
other than Eagle?
Cristian

  ----------

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[Non-text portions of this message have been removed]

----- Original Message ----- 

From: "Alexandre Souza" <alexandre-listas@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, August 04, 2004 2:17 PM
Subject: Re: [Homebrew_PCBs] advanced routing


> > That can help a lot. The software I use highlights an entire net when it
> is
> > selected. I can use different colours for different nets, as well.
>
>     Leon, can you say more about the software you use, and how it compares
> to Protel?

I've used Pulsonix since it first came out: http://www.pulsonix.com

I'm one of their beta testers, so I'm biased. Try the demo (100 pins limit).
They will give you a fully working 30 day license if you need to check it
properly.

I tried the latest Protel, just out of curiosity. It's rather slow on my
hardware, and difficult to use. It has lots more features than PSX, but they
aren't very useful, IMO. It's also a lot more expensive and has lots of
bugs, according to the PEDA list, which they don't fix until the next
release. The autorouter is still unusable, apparently. PSX has very few bugs
(I and the other testers catch most of them) and they get fixed immediately
they are reported.

I formed a PSX users group: http://groups.yahoo.com/group/PulsonixUG/. It
gets very little use, because the product is so easy to use and the support
is so good.

Leon

--- In Homebrew_PCBs@yahoogroups.com, Cristian <bip@f...> wrote:
> Hi List.
> Any idea where to find free or cheap Standalone Milling Isolation
Software, 
> other than Eagle?
> Cristian

Try this one next. The board size might be limited

http://ibfriedrich.com/

Here is a FREEWARE version

http://www.lce.org/cnc/

Lots of good ideas, Leon.  I use most of them as well.  Wish eagle 
allowed the colored "air wire" thing as i spend too much time 
checking to see it is a supply connection.  

My wife did PCB design for many years and I asked her the advanced 
routing question.  She just laughed, shook her head and 
said "beginners. there is no magic book".  No suprise to me.  It just 
boils down to a set of design rules and techniques.  There is no 
substitution for experience.

A couple more thoughts:

I spend a lot of time looking at the schematic trying to get a sense 
of what goes best with what.  This helps me to place components in 
their best position.  I have a dual monitor set up so I can keep the 
board on one screen and the schematic on the other.  That really 
speeds up placement.

For pins that are swappable, I will change the schematic to simplify 
the layout.  By swappable, I mean any pins that can be exchanged for 
same function.  For examnple, a hex not gate has 6 inputs and 6 
outputs that can be used for the same purpose.  swapping gate 1 for 2 
may lead to simpler layout.  Same thing for microprocessor register 
pins (non-dedicated ones, of course).  Headers are another place 
where you might be able to move things around to simplify layout.  I 
guess PLDs are the ultimate case.  I bop back and forth between the 
schematic and board swapping things around, often to significant 
improvement.  Clearly, there are times when you dont want to 
complicate programming but who cares if a function is on port B pin 1 
or 2, for example.  Its kind of a pet peeve of mine that chip 
designers don't always consider layout complexity when they assign 
pins.  Compare AVR vs midrange PIC in system programming pins, for 
example (AVR got it right).

By the way, I also put SMDs on the "solder" side when doing mixed 
TH/SM layouts to avoid vias for boards I'm making myself.  If it 
prevents a drill hole, it is good.  But then if I'm using a board 
house, I dont care, so viva las vias!

Phil

--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
<leon_heller@h...> wrote:
> ----- Original Message ----- 
> From: "Stefan Trethan" <stefan_trethan@g...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Wednesday, August 04, 2004 9:35 AM
> Subject: [Homebrew_PCBs] advanced routing
> 
> 
> > Hi,
> >
> > i was wondering if there is a tutorial for advanced routing.
> > I mean as soon as you have two layers and more than 100components
> > it starts to get more difficult.
> > If there is no tutorial we could maybe exchange some tricks.
> 
> I've looked and I don't think there is one.
> 
> Here are a few 'rules of thumb' I've come across which I find very 
useful:
> 
> >
> > How do you start?
> 
> Start placement with the largest parts.
> 
> > How do you decide which parts are on which side?
> 
> > (i put the SMD ones on top which can be connected to throughhole 
without
> > adding a via, and i aim for the same population density top and 
bottom.)
> 
> For low-cost manufacture it's best to put all the SMDs on the top. 
If you
> put them on top and bottom your technique seems OK.
> 
> >
> > Often it is required to rotate and rearrange parts to get a good 
layout,
> > but at a certain number of parts it is very hard to keep track of 
things.
> 
> Try to keep the components in functional blocks, like in the 
schematic. An
> autorouter can be useful, even if you are routing manually, to show 
where
> there are going to be problems. If you are using an autorouter, 
here are
> some tips:
> 
> http://www.connecteda.com/doc/Autorouting%20Techniques.pdf
> 
> They are applicable to any autorouter. BTW, that Electra autorouter 
is
> *very* good, it's now supplied with the Pulsonix software I use.
> 
> >
> > Do you start routing with special nets, like supply?
> 
> Critical nets like power and ground, and clocks, etc. should always 
be
> routed first.
> 
> >
> > You see, the methods i used for years on smaller circuits seem 
very, very
> > hard
> > to apply to bigger circuits, and i believe there must be some 
tricks i
> > don't
> > know yet.
> > Maybe if everyone throws in a few ideas we can all learn 
something.
> 
> Placement is the important thing, once that is optimised the actual 
routing
> should be quite easy, until you get to the last few tracks - they 
will take
> as long as all the others put together. 8-)
> 
> Always start by routing the shortest tracks, working up to the 
longest. That
> is probably the most important rule.
> 
> 
> > I always use different color "rubber bands" for GND and VCC which 
helps a
> > bit.
> 
> That can help a lot. The software I use highlights an entire net 
when it is

> selected. I can use different colours for different nets, as well.
> 
> Leon
> --
> Leon Heller, G1HSM
> http://www.geocities.com/leon_heller

Thanks,  but I need only to convert the Gerber Output of a PCB software to 
an HPGL isolation.

I use Abacom's Sprint Layout software to copy the magazine PCB drawings for 
my hobby.

Owing a cnc milling machine I use the IsoCAM of MDA Electronics to get the 
isolation file.
My problem is: MDA wants a LPT Key (I've bought with the IsoCAM) and now, 
the notebooks (I work on travel) have no LPT.
This is the reason I'm looking for an standalone isolation sw, to replace 
IsoCAM.
Any idea?
Cristian

> > Any idea where to find free or cheap Standalone Milling Isolation
>Software,
> > other than Eagle?
> > Cristian
>
>Try this one next. The board size might be limited
>
>http://ibfriedrich.com/



  ----------

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[Non-text portions of this message have been removed]

----- Original Message ----- 

From: "Phil" <phil1960us@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, August 04, 2004 5:57 PM
Subject: [Homebrew_PCBs] Re: advanced routing


> Lots of good ideas, Leon.  I use most of them as well.  Wish eagle
> allowed the colored "air wire" thing as i spend too much time
> checking to see it is a supply connection.
>
> My wife did PCB design for many years and I asked her the advanced
> routing question.  She just laughed, shook her head and
> said "beginners. there is no magic book".  No suprise to me.  It just
> boils down to a set of design rules and techniques.  There is no
> substitution for experience.
>
> A couple more thoughts:
>
> I spend a lot of time looking at the schematic trying to get a sense
> of what goes best with what.  This helps me to place components in
> their best position.  I have a dual monitor set up so I can keep the
> board on one screen and the schematic on the other.  That really
> speeds up placement.

I do that as well. Pulsonix has a 'Group' facility that allows components to
be grouped on the schmatic so that they are associated on the PCB but I keep
forgetting to use it.

>
> For pins that are swappable, I will change the schematic to simplify
> the layout.  By swappable, I mean any pins that can be exchanged for
> same function.  For examnple, a hex not gate has 6 inputs and 6
> outputs that can be used for the same purpose.  swapping gate 1 for 2
> may lead to simpler layout.  Same thing for microprocessor register
> pins (non-dedicated ones, of course).  Headers are another place
> where you might be able to move things around to simplify layout.  I
> guess PLDs are the ultimate case.  I bop back and forth between the
> schematic and board swapping things around, often to significant
> improvement.  Clearly, there are times when you dont want to
> complicate programming but who cares if a function is on port B pin 1
> or 2, for example.  Its kind of a pet peeve of mine that chip
> designers don't always consider layout complexity when they assign
> pins.  Compare AVR vs midrange PIC in system programming pins, for
> example (AVR got it right).

Pulsonix allows 'swappable' pins and gates to be swapped on the PCB, and the
schematic may then be back-annotated.

>
> By the way, I also put SMDs on the "solder" side when doing mixed
> TH/SM layouts to avoid vias for boards I'm making myself.  If it
> prevents a drill hole, it is good.  But then if I'm using a board
> house, I dont care, so viva las vias!

I have to put SMDs on the underside, as all my boards are single-sided. I
really ought to start making my own DS boards.

Leon

--- In Homebrew_PCBs@yahoogroups.com, Cristian <bip@f...> wrote:
> Hi List.
> Any idea where to find free or cheap Standalone Milling Isolation 
Software, 
> other than Eagle?
> Cristian

WinQCAD is a more user interface friendly software than Eagle.

Heck, even I can use it.

It has an internal CNC output so you can go directly from schematic 
to board layout to CNC output for you drilling and/or milling.

Also, there are many free conversion programs from Gerber output from 
your PCB software to G-Code which is what the CNC machine use.

Dave

> >     Leon, can you say more about the software you use, and how it
compares
> > to Protel?
> I've used Pulsonix since it first came out: http://www.pulsonix.com

    And what about the libraries? And the price?

    I'm looking for a REASONABLY PRICED (no, protel isn't reasonably priced)
tool for PCB use, maybe pulsonix can have a chance.

    Thanks for your attention!


---
Outgoing mail is certified Virus Free.
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----- Original Message ----- 

From: "Alexandre Souza" <alexandre-listas@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, August 04, 2004 7:51 PM
Subject: Re: [Homebrew_PCBs] advanced routing


> > >     Leon, can you say more about the software you use, and how it
> compares
> > > to Protel?
> > I've used Pulsonix since it first came out: http://www.pulsonix.com
>
>     And what about the libraries? And the price?
>
>     I'm looking for a REASONABLY PRICED (no, protel isn't reasonably
priced)
> tool for PCB use, maybe pulsonix can have a chance.

The libraries are quite good, some mistakes though. Most people make their
own, anyway.

Prices start at $3,000, IIRC. Prices are on the web site. Easy-PC (same
company) is very good also, it's intended more for the hobbyist market:

http://www.numberone.com

Prices start at under $200.

Leon

The gist of Drs Ames and Gold's (et al) research is that trace and
even moderate chemical exposures are not plausible cancer triggers.
About half of all chemicals tested, whether synthetic or naturally
occurring, even chemicals most prople are continually exposed to, will
test positive as 'potent cacinogens' using the current metrics. Yet
the age and discovery weighted cancer rate has been slowly falling for
about 100 years.

Jimbo


> > 
> > http://europa.eu.int/comm/environment/ppps/ma_reding_annex2.pdf
> 
> Very interesting article. It seems from reading the article that
testing 
> what chemicals are and are not carcinogenic is going to take a lot more 
> time and effort (i.e $$$) than before.

--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
<leon_heller@h...> wrote:
> ----- Original Message ----- 
...
> 
> Pulsonix allows 'swappable' pins and gates to be swapped on the 
PCB, and the
> schematic may then be back-annotated.
> 

eagle does too for pins but not gates.  does psx?   also, I suspect 
no layout sw allows uP register pins to be swapped. 

> >
> > By the way, I also put SMDs on the "solder" side when doing mixed
> > TH/SM layouts to avoid vias for boards I'm making myself.  If it
> > prevents a drill hole, it is good.  But then if I'm using a board
> > house, I dont care, so viva las vias!
> 
> I have to put SMDs on the underside, as all my boards are single-
sided. I
> really ought to start making my own DS boards.

Wow, I think I'd go crazy if I didn't do DS boards.  Its really not 
much more work at all.

Phil

----- Original Message ----- 

From: "Phil" <phil1960us@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, August 05, 2004 6:01 AM
Subject: [Homebrew_PCBs] Re: advanced routing


> --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
> <leon_heller@h...> wrote:
> > ----- Original Message ----- 
> ...
> > 
> > Pulsonix allows 'swappable' pins and gates to be swapped on the 
> PCB, and the
> > schematic may then be back-annotated.
> > 
> 
> eagle does too for pins but not gates.  does psx?   also, I suspect 
> no layout sw allows uP register pins to be swapped. 

Yes, it swaps gates. Any pins can be set for swap.

Leon

Stefan,

Mariss Friemanis of Gecko drives mentioned some good information 
about how he lays out his SMD VERY densely populated drives. It 
involved some "strange" values for the layout grid, and included soem 
thought about where to run vias and ancillary parts...

Un fortunately, I'm not sure where I filed it. But he's known to be 
quite helpful, and hangs out at several groups including the 
electronics 101 group that I think belongs to our list owner here?

Anyways, I'd call him, or at least ask on a user group where he's 
evident. It was VERY good info, and of the type borne of hard-won 
empirical experience, not book learning...

Hope this helps,

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> Hi,
> 
> i was wondering if there is a tutorial for advanced routing.
> I mean as soon as you have two layers and more than 100components
> it starts to get more difficult.
> If there is no tutorial we could maybe exchange some tricks.
> 
> How do you start?
> How do you decide which parts are on which side?
> (i put the SMD ones on top which can be connected to throughhole 
without
> adding a via, and i aim for the same population density top and 
bottom.)
> 
> Often it is required to rotate and rearrange parts to get a good 
layout,
> but at a certain number of parts it is very hard to keep track of 
things.
> 
> Do you start routing with special nets, like supply?
> 
> You see, the methods i used for years on smaller circuits seem 
very, very 
> hard
> to apply to bigger circuits, and i believe there must be some 
tricks i 
> don't
> know yet.
> Maybe if everyone throws in a few ideas we can all learn something.
> 
> I always use different color "rubber bands" for GND and VCC which 
helps a 

> bit.
> 
> ST

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
...
> Nah i don' think he's goin to kick my ass outa' here.
> If he wants having me contribute to the discussion he must endure
> my comments from time to time. If i find something out of order
> i will say so, nothing wrong with that. Everyone seems to ignore
> me anyway as they know i can't do a thing.

Stefan, I don't see you changing the subject line. Glass house,
stones, etc.

However, not everyone has been here that long. It can have a chilling
effect and skew the direction of the list. I've seen this happen- one
or  two play listcop, when it is revealed they are just members, other
troublemakers decide it's the Old West all over again and a huge mess
ensues.

Sorry, Stefan, you are being placed on moderated status again. I
thought it was a pretty simple request.

I really hate doing this.

Steve

By swapping gates, do you mean that you can point to two different 
not gates (or nors or nands), say swap and it will swap inputs AND 
outputs?  If so, that's pretty cool.

--- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
<leon_heller@h...> wrote:
> ----- Original Message ----- 
> From: "Phil" <phil1960us@y...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Thursday, August 05, 2004 6:01 AM
> Subject: [Homebrew_PCBs] Re: advanced routing
> 
> 
> > --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
> > <leon_heller@h...> wrote:
> > > ----- Original Message ----- 
> > ...
> > > 
> > > Pulsonix allows 'swappable' pins and gates to be swapped on the 
> > PCB, and the
> > > schematic may then be back-annotated.
> > > 
> > 
> > eagle does too for pins but not gates.  does psx?   also, I 
suspect 

> > no layout sw allows uP register pins to be swapped. 
> 
> Yes, it swaps gates. Any pins can be set for swap.
> 
> Leon

----- Original Message ----- 

From: "Phil" <phil1960us@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, August 05, 2004 7:25 PM
Subject: [Homebrew_PCBs] Re: advanced routing


> By swapping gates, do you mean that you can point to two different 
> not gates (or nors or nands), say swap and it will swap inputs AND 
> outputs?  If so, that's pretty cool.

I think it does. I never use it. I do use pin swapping quite a lot, though.

Leon

There seems to be some confusion about what thread exactly I was ending.

I have no problem with discussions of chemical safety and precautions.
That is not only on topic, it is vital!

The only thread I ended was the controversy over whether or not IPA
(isopropyl alcohol) is a carcinogen. No matter which side you are on,
everyone seems to agree that it is dangerous and at least some
precautions need to be taken.

Steve, the listowner

--- In Homebrew_PCBs@yahoogroups.com, "ballendo" <ballendo@y...> 
wrote:
> Stefan,
> 
> Mariss Friemanis of Gecko drives mentioned some good information 
> about how he lays out his SMD VERY densely populated drives. It 
> involved some "strange" values for the layout grid, and included 
soem 
> thought about where to run vias and ancillary parts...
> 
> Un fortunately, I'm not sure where I filed it. But he's known to be 
> quite helpful, and hangs out at several groups including the 
> electronics 101 group that I think belongs to our list owner here?



correct, it was on Electronics-101

Here it is as a copy 

"quote from post # 5905 from Electroncis-101



Re: PCB design - good practices? 
Bret,

I use ACAD for PCB layout design and a program called Autogerb to
convert the results to a gerber format (.gbr).

You may want to use a .008333" grid. If you use thru-hole parts, (DIP
ICs), then use .058333" dia. pads with a .032" dia. plated-thru holes.

Make the traces and spaces .008333" wide. This will permit you to
sneak two traces between IC pins, (.100" between pins, .041666" space
between pads, leaving room for .008333" space, trace, space, trace
and space.

Use 45 degree turns instead of 90 degrees for traces.

Inspecting finished (stuffed) circuits is easier from the bottom.
Place most of your circuit interconnect traces there. Use the top
side for power distribution (fat traces).

Use plated-thru "vias" where necessary to complete circuit
connections. Via holes can be .025", with a via pad dia. of .041666"
(.025" hole, .008333" annular ring). Solder-mask the via pads (no
solder).

These rules also work for SMT components but only a single trace will
fit between surface-mount IC pins.

Mariss

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "ballendo" <ballendo@y...> 
> wrote:
...
> > quite helpful, and hangs out at several groups including the 
> > electronics 101 group that I think belongs to our list owner here?

> correct, it was on Electronics-101

http://groups.yahoo.com/group/Electronics_101/

I'm just a moderator there.

It's a good group, lots of crossover between that and this group.

Steve

> WinQCAD is a more user interface friendly software than Eagle.
> 
> Heck, even I can use it.
> 
> It has an internal CNC output so you can go directly from schematic 
> to board layout to CNC output for you drilling and/or milling.
> 
> Also, there are many free conversion programs from Gerber output 
from your PCB software to G-Code which is what the CNC machine use.
> 
> Dave

I just tried this out

Very Nice program.

I would suggest that you run throught the tutorial First.

I drew up the sample board and dumped it out to G-Codes and then 
milled a demo board into a piece of lexan using a dremmel ball bit 
and it came out really nice.

(I need to order some real PC Board bits)

I think this one may be a keeper.

The demo will do up to 499 Pads

http://www.pulsonix.com/prices.asp  FYI Mike




--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
> By swapping gates, do you mean that you can point to two different 
> not gates (or nors or nands), say swap and it will swap inputs AND 
> outputs?  If so, that's pretty cool.
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
> <leon_heller@h...> wrote:
> > ----- Original Message ----- 
> > From: "Phil" <phil1960us@y...>
> > To: <Homebrew_PCBs@yahoogroups.com>
> > Sent: Thursday, August 05, 2004 6:01 AM
> > Subject: [Homebrew_PCBs] Re: advanced routing
> > 
> > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "Leon Heller" 
> > > <leon_heller@h...> wrote:
> > > > ----- Original Message ----- 
> > > ...
> > > > 
> > > > Pulsonix allows 'swappable' pins and gates to be swapped on 
the 

> > > PCB, and the
> > > > schematic may then be back-annotated.
> > > > 
> > > 
> > > eagle does too for pins but not gates.  does psx?   also, I 
> suspect 
> > > no layout sw allows uP register pins to be swapped. 
> > 
> > Yes, it swaps gates. Any pins can be set for swap.
> > 
> > Leon

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> I searched but weren't able to locate any posts on the subject but 
I 
> recall that tehre was a dicussion of it. Does anyone know a simple 
> method that works on plating holes in a PCB?  Mike

I am also interested in this topic.  I have done some research and 
have found some non-chemical approaches to plated thru holes.  One 
that I haven't seen mentioned here is from a Japanese company called 
Sanhayato and described in this page http://www.hobby-
elec.org/e_pwbm43.htm .  The cylinder is filled with solder to give 
it rigidity during the break-off (notice the scoring on the cylinder)
step.  As shown, there are 25 scores on the tube.  The downside is 
that the company is in Japan.  MITS Electronics seem to sell this 
product at http://www.mits.co.jp/edoc/etool_t.htm which has North 
American distribution in Canada at 
http://www.mits.co.jp/edoc/agent.htm .  

Another company that appears to sell an equivalent Sanhayato cylinder 
is a company called Multicore Solders that makes a product called 
Copperset.  Copperset is sold by T-Tech, Inc at http://www.t-
tech.com/materials/throughhole/ .

I'm in the process of getting quotes for pricing and availability but 
was wondering if anyone has had any experience using either of these 
products.

John

Solder pins (the ones for which you can buy plugs (1mm and 1.3mm)
make nice vias. use them instead of "wire soldered to the board" connectors
and have a easy-to-solder free via. the advantage over small pieces of  
wire is that
you press in the pins with a tool (homebrew, metal piece with hole in it).  
Then
they sit snugly in the hole and won't fall out. Bot sides easily  
solderable.
Price: 1eur/100pins. If you want no off-board connector there snip off the  
pin after placing.

Downside: rather large, 1mm dia.


I use them for board connections because screw terminals are too expensive.
Also you can put solder pins anywhere on the board, not only the edges,  
which makes
layout easy. They are silver plated which ensures long-lasting.

ST

Sounds very interesting!  Could you provide a manufacturer and a 
source?

"Stefan Trethan" <stefan_trethan@g...> wrote:

> Solder pins (the ones for which you can buy plugs (1mm and 1.3mm)
> make nice vias. use them instead of "wire soldered to the board" 
connectors

> and have a easy-to-solder free via. 
> ...
> ST

On Thu, 12 Aug 2004 02:54:12 -0000, flyrgeorge <jfritz@...> wrote:

> Sounds very interesting!  Could you provide a manufacturer and a
> source?

<http://www.elcomp.at/Sit-Grup/Gr10/10-03-03C-Stifte-Osen-Leisten.htm>

But they are so widespread and common you can find a source closer to you.

ST

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> On Thu, 12 Aug 2004 02:54:12 -0000, flyrgeorge <jfritz@n...> wrote:
> 
> > Sounds very interesting!  Could you provide a manufacturer and a
> > source?
> 
> <http://www.elcomp.at/Sit-Grup/Gr10/10-03-03C-Stifte-Osen-
Leisten.htm>
> 
> But they are so widespread and common you can find a source closer 
to you.
> 
> ST


HEre is the link to Digi-key.

I sometimes use these ED5038  pin recepticles.

they are similar to DIP sockets.  You can use DIP sockets and cut the 
pins out and then break off the little end bits for a similar 
socket.  the neat thing is that they come in different sizes and you 
can use them as quick sockets for caps or resistors.

http://dkc3.digikey.com/PDF/T042/0276.pdf

They come in many different hole dimeters and lenghts but make sure 
you get the holes that will fit the pins you want to use.

They can be soldered on top and bottom to make vias.

Dave

>> <http://www.elcomp.at/Sit-Grup/Gr10/10-03-03C-Stifte-Osen-
> Leisten.htm>
>>


> HEre is the link to Digi-key.
>
> I sometimes use these ED5038  pin recepticles.
>
> they are similar to DIP sockets.  You can use DIP sockets and cut the
> pins out and then break off the little end bits for a similar
> socket.  the neat thing is that they come in different sizes and you
> can use them as quick sockets for caps or resistors.
>
> http://dkc3.digikey.com/PDF/T042/0276.pdf
>
> They come in many different hole dimeters and lenghts but make sure
> you get the holes that will fit the pins you want to use.
>
> They can be soldered on top and bottom to make vias.
>
> Dave
>

Nice...
They are something completely different than the solder pins i suggested  
however.
They would be better for low current, and as you said for components. Not  
so much for
off-board connectors it seems.

there are female plugs for the solder pins, which are meant to be soldered  
or crimped to a wire.
I use them for off-board connections. They also make convenient  
test-points (and affordable ones).
I'd say they are good for several amperes. the good thing is you can place  
them everywhere
on the board, not like screw terminals only where there is side-access.  
This makes routing much easier. Of course component legend is required to  
keep track of the pinout.

ST

Okay, I'm going to risk being shouted at here...

I have been through the archives (not all, but a hefty chunk of it - 
including the discussion around msg 1100 about through-plating).

When the subject of conductive silver paint arises, it usually gets 
sidetracked into the use of activators, copper plating etc, but 
nobody so far seems to have tried using silver paint to create the 
actual body of the vias. According to the manufacturers, a typical 
paint has a resistance of 200 microOhms per cm, and it can be 
thinned. 2 or 3 applications should be enough. Whilst it is 
expensive, I would imagine 3 grammes of the stuff would go a heck of 
a long way.

I have used through-pin style vias for years, and I would like to 
move on to play around with multi layer laminated boards etc (one of 
these years I may get around to BGA). So, has anyone tried it, or am 
I going to be the one to save up for a bottle of silver?

Which reminds me, is it feasible to "solder" components with silver 
loaded epoxy? Obviously reworking would be a $"£%! of a job...

Mike

Mike,
Long ago Model Railroaders used the silver paint to make a conductive 
path between one wheel to a resistor, then from the other side of the 
resistor to the other wheel. The purpose was to provide a resistive 
load between the two rails to allow signal and other circuits to 
activate when boxcars were left on the main line (otherwise, as the 
wheels are normally insulated from each other, the signals would NOT 
show the presence of a car) and thereby stop approaching model 
trains. I used some silver paint long ago (yes very $$$ back then) 
and I may have some left over way, way down in the bottom of the junk 
box somewhere. My experience was that while it did conduct, it didn't 
last very long - maybe the application was the problem.  I would hope 
that better paint/bonding agents would be used in today's paint, but 
unsure. 

Personally, with soldering a scrap piece of wire, or using one of the 
other discussed via methods being so easy (and repairable) I will not 
be spending the money on the paint.  Remember, when paint dries it 
tends to become brittle and possibly even crack with heat. I guess if 
it really worked that good/reliably, the "big boys" would be using 
something like that on the professional boards. Just a thought.

Keep us posted if you decide to try it.
Mike R.

<snip>
> When the subject of conductive silver paint arises, it usually gets 
> sidetracked into the use of activators, copper plating etc, but 
> nobody so far seems to have tried using silver paint to create the 
> actual body of the vias. According to the manufacturers, a typical 
> paint has a resistance of 200 microOhms per cm, and it can be 
> thinned. 2 or 3 applications should be enough. Whilst it is 
> expensive, I would imagine 3 grammes of the stuff would go a heck 
of 
> a long way.

Mike,
Long ago Model Railroaders used the silver paint to make a conductive 
path between one wheel to a resistor, then from the other side of the 
resistor to the other wheel. The purpose was to provide a resistive 
load between the two rails to allow signal and other circuits to 
activate when boxcars were left on the main line (otherwise, as the 
wheels are normally insulated from each other, the signals would NOT 
show the presence of a car) and thereby stop approaching model 
trains. I used some silver paint long ago (yes very $$$ back then) 
and I may have some left over way, way down in the bottom of the junk 
box somewhere. My experience was that while it did conduct, it didn't 
last very long - maybe the application was the problem.  I would hope 
that better paint/bonding agents would be used in today's paint, but 
unsure. 

Personally, with soldering a scrap piece of wire, or using one of the 
other discussed via methods being so easy (and repairable) I will not 
be spending the money on the paint.  Remember, when paint dries it 
tends to become brittle and possibly even crack with heat. I guess if 
it really worked that good/reliably, the "big boys" would be using 
something like that on the professional boards. Just a thought.

Keep us posted if you decide to try it.
Mike R.

<snip>
> When the subject of conductive silver paint arises, it usually gets 
> sidetracked into the use of activators, copper plating etc, but 
> nobody so far seems to have tried using silver paint to create the 
> actual body of the vias. According to the manufacturers, a typical 
> paint has a resistance of 200 microOhms per cm, and it can be 
> thinned. 2 or 3 applications should be enough. Whilst it is 
> expensive, I would imagine 3 grammes of the stuff would go a heck 
of 
> a long way.

--- In Homebrew_PCBs@yahoogroups.com, "mikeromp2002" <MikeRomp@m...> 
wrote:

> Personally, with soldering a scrap piece of wire, or using one of 
the 
> other discussed via methods being so easy (and repairable) I will 
not 
> be spending the money on the paint.  Remember, when paint dries it 
> tends to become brittle and possibly even crack with heat. I guess 
if 
> it really worked that good/reliably, the "big boys" would be using 
> something like that on the professional boards. Just a thought.
> 
> Keep us posted if you decide to try it.
> Mike R.

It looks like I'm going to be the one to save up £6 and nip down
to Maplins some time (Farnell, RS etc are the same price). Quite a 
few people seem to have success using it for bridging clock divider 
pins on AMD processors, so I imagine thermal cycling (and fairly high 
temperature) isn't a problem for the modern stuff. In fact, according 
to the data sheets it seems that curing it at 85deg C or so gives a 
lower resistance.

I intend to use several thinned applications of paint, followed by a 
coating of something to stop the oxygen attacking it. The idea is to 
be able to connect up layers on a laminated board (initially 3 layer, 
1 double sided bonded to 1 single sided). Using the wire method would 
take 2 vias, the first to connect the 2 sides of the double sided 
(and thoroughly smoothed off), then another to connect the 2 outer 
layers. A blind via from inner to the outer of the single sided board 
wouldn't be possible with wire. 

The hope is that maybe I can get connection density high enough to 
support BGA packages, where there just isn't room for wired jumper 
vias. My motivation is that I have a device that I really would like 
to use but is only available in BGA, and increasingly the interesting 
stuff has no alternative (ARM processors, memory, high speed ADCs 
etc).

All I need now is a free source of 0.4mm copperclad to experiment 
with!

Mike

> It looks like I'm going to be the one to save up \ufffd6 and nip down
> to Maplins some time (Farnell, RS etc are the same price). Quite a
> few people seem to have success using it for bridging clock divider
> pins on AMD processors, so I imagine thermal cycling (and fairly high
> temperature) isn't a problem for the modern stuff. In fact, according
> to the data sheets it seems that curing it at 85deg C or so gives a
> lower resistance.
>

I regularly use it to repair "printed" (unsolderable - on plastic) stuff  
like
keyboards (i like to change key functions if they are not where i want  
them).

I fixed my AMD by soldering the bridges, after seeing they can solder the  
smd
caps i was sure i can do that too.

I still don't like the paint, it is ridiculously expensive.
I'm also not sure how it would be applied in a hole, and i doubt it
is faster than soldering a via.

ST

> I still don't like the paint, it is ridiculously expensive.
> I'm also not sure how it would be applied in a hole, and i doubt it
> is faster than soldering a via.


I can't read seven thousand posts, so I don't know if this method has
been presented before. But in case it hasn't:

1. When laying out PCB, take note of the component type and don't
depend on a through-hole connection for devices that sit over the hole.

2. Strip about a foot of fine copper wire and *lace* through many vias
at once.

3. Solder vias, strip more wire if necessary and repeat. Lacing the
wire through the board will hold it in place while you solder.

4. Cut off excess wire flush to board, and solder the rest of the
components.

This is about the fastest way possible. Even the little plugs require
you to solder both sides, and any electroplating process takes a huge
amount of time and effort. It just takes a small amount of forethought
when laying out the PCB.

yup, that's what I do too.  Its quick and easy.   You do have to be 
careful of placing vias near solder points as you can inadvertantly 
remelt the via solder and the via wire *can* drop out.  When you dont 
notice, it makes for some debug fun...

I use salvaged cat 5 wire which is, I think, 28 gauge.

--- In Homebrew_PCBs@yahoogroups.com, "cybermace5" <cybermace5@y...> 
wrote:
> > I still don't like the paint, it is ridiculously expensive.
> > I'm also not sure how it would be applied in a hole, and i doubt 
it
> > is faster than soldering a via.
> 
> 
> I can't read seven thousand posts, so I don't know if this method 
has
> been presented before. But in case it hasn't:
> 
> 1. When laying out PCB, take note of the component type and don't
> depend on a through-hole connection for devices that sit over the 
hole.
> 
> 2. Strip about a foot of fine copper wire and *lace* through many 
vias
> at once.
> 
> 3. Solder vias, strip more wire if necessary and repeat. Lacing the
> wire through the board will hold it in place while you solder.
> 
> 4. Cut off excess wire flush to board, and solder the rest of the
> components.
> 
> This is about the fastest way possible. Even the little plugs 
require
> you to solder both sides, and any electroplating process takes a 
huge
> amount of time and effort. It just takes a small amount of 
forethought
> when laying out the PCB.

***ORIGINAL MESSAGE:

   Date: Thu, 19 Aug 2004 12:44:52 -0000

   From: "cybermace5" <cybermace5@...>
Subject: making vias (was: Re: Plating thruholes.)

> I still don't like the paint, it is ridiculously expensive.
> I'm also not sure how it would be applied in a hole, and i doubt it
> is faster than soldering a via.


I can't read seven thousand posts, so I don't know if this method has
been presented before. But in case it hasn't:

1. When laying out PCB, take note of the component type and don't
depend on a through-hole connection for devices that sit over the hole.

2. Strip about a foot of fine copper wire and *lace* through many vias
at once.

3. Solder vias, strip more wire if necessary and repeat. Lacing the
wire through the board will hold it in place while you solder.

4. Cut off excess wire flush to board, and solder the rest of the
components.

This is about the fastest way possible. Even the little plugs require
you to solder both sides, and any electroplating process takes a huge
amount of time and effort. It just takes a small amount of forethought
when laying out the PCB.

------------------------------------

***REPLY:

That sounds pretty good; fast and easy.

I am laying out some two-sided boards, at the moment. I would like to use
2x20 pin headers, with some surplus (new) IDE cables that I got (200
of them, new, for $5!), to make board-to-board connections.

One problem is that the headers sit flat on the board. So in order to 
connect them to both sides, it seems like I'll have to put another row
of holes next to each side, and solder on both sides of those holes. I
am considering just sticking some single-row 1x20 headers in them, but
upside-down so the long ends of the pins are in the holes, and leaving
the pins partially sticking out of both sides of the board and then soldering
on both sides, at each pin.  Seems like a lot of fuss, though, just to install
a header on a two-sided board. (Although it WILL provide nicely-accessible
test-points...)

One problem, in this particular case, is that I'm modifying an older 1-sided
board design, to eliminate all of the wires that used to get soldered directly 
to the board. So I'm putting all of the new traces, from the 
wire-connection-points to the headers, on the TOP of the board, along with
the headers, so the ribbon cables can be plugged in from the top. (These
boards are mounted horizontally, on the bottom of a cabinet.)

It sure seems like there ought to be a much easier, "cleaner" way, though.

Regards,

Tom Gootee

http://www.fullnet.com/u/tomg

------------------------------------


[Non-text portions of this message have been removed]

>
> That sounds pretty good; fast and easy.
>
> I am laying out some two-sided boards, at the moment. I would like to use
> 2x20 pin headers, with some surplus (new) IDE cables that I got (200
> of them, new, for $5!), to make board-to-board connections.
>
> One problem is that the headers sit flat on the board. So in order to
> connect them to both sides, it seems like I'll have to put another row
> of holes next to each side, and solder on both sides of those holes.

You can solder the 2-row headers top side.
Just keep 2mm distance between the board and the molded plastic and hold
the iron relatively flat against the board when soldering.
Done it, worked without a bad connection (~100pins).
You could get longer headers if you like (e.g. wire-wrap version) but it  
works
with the standard ones too.

ST

> It sure seems like there ought to be a much easier, "cleaner" way,
though.
> 
> Regards,
> 
> Tom Gootee


There is.

When I'm doing a one-off, home hack project that will go in a case and
no one will ever see it except me, making a PCB at home is pretty
quick and does the job.

When I'm making a board that has a lot of detail, fine-pitch surface
mount parts, and could be on display or is designed as a prototype for
a client, I simply order from Olimex. $26 for a double-sided 4"x6" PCB
with PTH, solder mask, and silkscreen. Plus you can send them several
different files and a sketch of how they are laid out on the standard
panel, and they'll cut it out for no extra charge no matter how many
you have on there. A lot of surface-mount projects use boards that are
under 2 inches square, so you get a lot of boards for your money.

Making circuit boards at home is a worthwhile skill and has advantages
in certain situations. However, for me, there is a limit to how much
equipment, time, and chemical exposure is worth the added features.
There are so many PCB prototyping and production houses these days, if
you want solder mask, plated holes, and silkscreen they have the
skills and the safety measures already in place. Someday I would like
to see fully-populated board production to be as cheap as PCB
prototyping; that eliminates the hassle of trying to solder BGA and
QFN packages by hand, and gives me more time to design subassemblies
instead of soldering microscopic parts. This will be required at some
point in the future, if we want to advance the hobby to follow the
state of the art. There will still be a lot of work, but we will be
capable of more complex projects.

> It sure seems like there ought to be a much easier, "cleaner" way,
though.


I forgot to mention a little trick with 0.1" spaced double-row headers.

Don't know if your board layout will work with this. But if your PCB
substrate is thick enough, like the popular 0.06"-ish thickness, it is
possible to line up a 0.1" spaced row of SMD pads on the top and
bottom of an edge of the board. Then you can slide the double-row
header on the edge and solder it there, at right angles to the board.
There is usually a tiny bit of clearance left over so it's not an
exceptionally snug fit, but it is close enough to solder quite firmly.
The clearance can also be taken up easily by pressing the two rows of
pins towards each other with the barest squeeze in the jaws of a vise.

As I said before, don't know if edge-connecting will work with your
setup, but it's still a useful tip.

If these are straight headers, I've had success soldering the header 
pins on the bottom, gently prying up the plastic spacer (or what ever 
its called) that is now flush with the top (ie component side), 
soldering on the top side and then pushing the plastic spacer back 
down.  You have to be sparing of solder on the top side.  You also 
have to watch the heat on the plastic spacer as it melts very easily.

If you are converting from 1 sided to 2 sided, you might want to 
consider completely rerouting the board.  You may find that routing 
really long runs on the top can significantly clean the board up.  I 
often put +V on the top.

--- In Homebrew_PCBs@yahoogroups.com, "Thomas P. Gootee" <tomg@f...> 
wrote:
> 
> ***ORIGINAL MESSAGE:
> 
>    Date: Thu, 19 Aug 2004 12:44:52 -0000
>    From: "cybermace5" <cybermace5@y...>
> Subject: making vias (was: Re: Plating thruholes.)
> 
> > I still don't like the paint, it is ridiculously expensive.
> > I'm also not sure how it would be applied in a hole, and i doubt 
it
> > is faster than soldering a via.
> 
> 
> I can't read seven thousand posts, so I don't know if this method 
has
> been presented before. But in case it hasn't:
> 
> 1. When laying out PCB, take note of the component type and don't
> depend on a through-hole connection for devices that sit over the 
hole.
> 
> 2. Strip about a foot of fine copper wire and *lace* through many 
vias
> at once.
> 
> 3. Solder vias, strip more wire if necessary and repeat. Lacing the
> wire through the board will hold it in place while you solder.
> 
> 4. Cut off excess wire flush to board, and solder the rest of the
> components.
> 
> This is about the fastest way possible. Even the little plugs 
require
> you to solder both sides, and any electroplating process takes a 
huge
> amount of time and effort. It just takes a small amount of 
forethought
> when laying out the PCB.
> 
> ------------------------------------
> 
> ***REPLY:
> 
> That sounds pretty good; fast and easy.
> 
> I am laying out some two-sided boards, at the moment. I would like 
to use
> 2x20 pin headers, with some surplus (new) IDE cables that I got (200
> of them, new, for $5!), to make board-to-board connections.
> 
> One problem is that the headers sit flat on the board. So in order 
to 
> connect them to both sides, it seems like I'll have to put another 
row
> of holes next to each side, and solder on both sides of those 
holes. I
> am considering just sticking some single-row 1x20 headers in them, 
but
> upside-down so the long ends of the pins are in the holes, and 
leaving
> the pins partially sticking out of both sides of the board and then 
soldering
> on both sides, at each pin.  Seems like a lot of fuss, though, just 
to install
> a header on a two-sided board. (Although it WILL provide nicely-
accessible
> test-points...)
> 
> One problem, in this particular case, is that I'm modifying an 
older 1-sided
> board design, to eliminate all of the wires that used to get 
soldered directly 
> to the board. So I'm putting all of the new traces, from the 
> wire-connection-points to the headers, on the TOP of the board, 
along with
> the headers, so the ribbon cables can be plugged in from the top. 
(These
> boards are mounted horizontally, on the bottom of a cabinet.)
> 
> It sure seems like there ought to be a much easier, "cleaner" way, 
though.

> 
> Regards,
> 
> Tom Gootee
> 
> http://www.fullnet.com/u/tomg
> 
> ------------------------------------
> 
> 
> [Non-text portions of this message have been removed]

Thanks, to everyone who replied so far, for the good suggestions and information!

This re-design is still in the very early stages. I don't know if this is too off-topic. But I'll post a sort of summary of the different board/connector options I'm considering (mostly copied from an email that I sent to a friend, recently, about this stuff).  Maybe some of you can set me straight, or offer some practical tips, or some ideas.

I am re-designing an instrument that I produce (both in kit form and pre-assembled), mainly to change the (printed circuit) board-to-board and board-to-front-panel wiring schemes.  The instrument in question is a "Curve Tracer" (a type of test equipment). See it at http://www.fullnet.com/u/tomg/gooteect.htm . Previously, the three circuit boards in the unit were all single-sided, with all through-hole components. And all connections to and from all front panel controls and i/o connectors, and other boards, were implemented as soldered-in discrete wires.

In order to make the instrument much easier to produce, easier to maintain, easier to upgrade, and maybe even more reliable, I am replacing ALL discrete wiring (if possible) with *socketed* connectors (and multi-wire cabling) and/or printed circuit board traces.  The front panel controls and i/o connectors are all being changed from solder-lug types to pcb-mount types. And a new printed circuit board is being added, for them, behind, and parallel to, the front panel.

All connections from front panel controls and i/o connectors, as well as all board-to-board connections, will now (probably) be routed through pcb traces on the new front panel pcb, to socketed connectors' sockets' pins. Each board will have at least one socketed (or other mass-) connection to the front panel's new pcb.

This re-design project is still in the VERY early design phase.  And I am still trying to finalize the basic interconnect method(s) that will be used.  I'm pretty sure that all of the boards will have to change from single-sided to double-sided, just to be able to have room to run the new traces to the connectors. The main board has at least 50 connections that need to go to the front panel (mostly), or to the other two boards.  The other two have fewer than 15 connections each that need to go to the front panel or to the other boards.  The three original boards are all mounted horizontally, next to each other, on small "risers"/spacers that are part of the bottom of the enclosure.  All three have one edge that is very close to (but perpendicular to) the front panel.

There are several possibilities that I have considered: 

1) pin headers on each pcb, with ribbon cables running to similar headers on the front panel's new pcb, or 

2) card-edge connectors on the front panel pcb, along the bottom, that each of the three pcboards' edges could plug into, or 

3) right-angle headers or sockets on each pcb, that would plug directly into straight headers or sockets on the front panel pcb (pin headers and sockets, or DIN, or even D-Sub), with NO CABLING necessary, or 

4) another new board, a "motherboard", in the bottom of the enclosure, with card-edge sockets, along with a total redesign of the current boards' layouts, so they could be mounted vertically, in the MB's sockets, and a new front panel pcb that would also plug into a card-edge socket on the new motherboard, or 

5) card-edge sockets on all the pcbs, with small pcbs that plug into them, with discrete wires or ribbon cables soldered to the small pcbs (i.e. hand-made custom card-edge-connector cabling, hehehe...), 

6) pcb-mount terminal blocks with discrete wires, or 

7) something similar to #1, but with some as-yet-unknown (to me) connector and/or cabling types (I even considered pcb-mountable modular phone jacks and cabling).

Which of those (probably out of #1 through #4) sound "good"?  

One immediate "problem" I can foresee, with just adding a second side to each pcb and then running traces (on the "new" side of each board) to pin headers: Our pcb-making process is rudimentary and does NOT include the ability to make plated-through holes. SO, to have headers that are connected to the new top side traces, while the connectors are also sitting on the top sides of the boards, I wouldn't be able to solder the top side's trace directly to the headers' pins, since the headers sit right on the boards. So I'd have to make an extra row of holes next to each header row, that could have pins inserted that could be soldered on both sides. (I was thinking I might just use a single-row header, upside down with the longer pins halfway into the holes. It might be "ugly". But it would also provide handy test-points...).

Many of the switches in the unit just happen to use groups of six connections. So, for many on-board and board-to-board "jumpers", short lengths (six or eight inches max, probably) of 6-conductor ribbon cables might be handy, although, changing to double-sided boards might ("should") eliminate that need.

The primary GOAL is still to make the unit easier, faster, and cheaper to assemble. SO, I really don't want to use cabling schemes that require a lot of time or expensive equipment, to assemble (IDC?). Socketed connections are preferred, so that units can be easily disassembled for repairs or board-level upgrades. If ribbon cables are used, I would prefer having pre-assembled cables available.

I did buy a couple-hundred new IDE 40-pin cables (with three 2x20 sockets each), for $5!  And I got several hundred 40-pin breakable gold-plated single-row pin headers for about $10. And I got 300 2.5-inch-long 36-wire ribbon cables that have 36-pin single-row sockets on both ends, for $30 including shipping, and 200 36-pin single-row gold-plated headers for about $5 or $10. (Actually, I got the *300* of the new IDE cables, for $5.99 plus $21.42 s/h.)

SO, I may end up cutting the IDE cables so they have just two sockets with about 8 inches of cable between them, and using those.  Or I may use the short 36-pin cables and single-row headers.  

However, I am ALREADY running into the problem of *possibly* not having enough ROOM on the new front-panel PCB, for that many large connectors.  SO I *STILL* probably need to find something smaller (fewer conductors), for the two smaller boards to use, to connect to the front panel PCB, and/or to the other boards.

ANOTHER IDEA:  If I could find a very large (and very cheap) surplus stockpile of ISA "RISER BOARDS" (or even 8-bit passive backplane boards, or somesuch) that have 5 or more slots, those could make PERFECT ready-made
motherboards, to mount in the bottom of the case, with the slots parallel to the front panel. Then ALL of my boards could plug into the slots and all be connected together, including the front panel.  Of course, I could make my own similar motherboard-type boards, fairly easily, with available card-edge connectors. (But the large, new card-edge-connectors are usually quite expensive. Maybe I can find a large surplus lot of them...) But MAYBE there's a really low-cost stockpile of something similar, somewhere, which would certainly make things MUCH easier and faster and cheaper. 

There are also several connections to the rear panel, usually with only one or two wires, that I need to worry about. I am thinking of using either one- and two-wire pin headers and sockets, for those, or small terminal blocks of some type.  However, I still would LIKE to have all pre-assembled cables (i.e. sockets already on both ends of appropriate-length cabling.

Peak currents in some of the signal conductors could reach 1.5 Amps. However, most of those waveforms are triangular or sawtooth, making the average (DC-equivalent) current only HALF of the peak value.  But the main DC power supply rails MAY have to be connected from the separate power supply board to the other boards using discrete wiring that's screwed into terminal blocks, for that reason (max current-carrying capability).

Sorry to have blathered-on for so long, here!  If there's anything you can offer, I'm all ears!

Thanks again!

Regards,

Tom

Tom Gootee
tomg@...
http://www.fullnet.com/u/tomg



[Non-text portions of this message have been removed]

On Fri, 20 Aug 2004 14:41:23 -0500, Thomas P. Gootee <tomg@...>  
wrote:

> Thanks, to everyone who replied so far, for the good suggestions and  
> information!
>
> This re-design is still in the very early stages. I don't know if this  
> is too off-topic. But I'll post a sort of summary of the different  
> board/connector options I'm considering (mostly copied from an email  
> that I sent to a friend, recently, about this stuff).  Maybe some of you  
> can set me straight, or offer some practical tips, or some ideas.
>


I didn't read all of your post but i will tell you a story a good teacher  
told me some
time ago.

He was working for a company making TVs, and had a new design to make.
Recently they had hired a guy which should make the units more reliable,  
by statistics and such.
He was to check all new designs.
Well, my teacher designed the new TV as usual with plug-in cards.
After he was done he showed it to the reliability guy to be checked.
This guy only asked him if he is mad using several hundred connections.
He told him he an forget about the plug-in cards because the statistics  
say they
will fail too often. That meant a major redesign of the unit of course.
That was the last Plug-in type TV he built, from then they only used  
single boards or
soldered connections.

so i wouldn't say connectors make things reliable.

Another issue is upgradeability. I expect every single one of your  
customers
to be well able to solder and even design circuits.
Do you really believe a PCB for all the front-plate elements is a good  
idea?
It would be MUCH harder to add an additional connector or something then.

If i were you i'd just put a solder pin in every wire pad. Then solder the
suitble pug to the wire and done. You can easily take it apart with no  
redesign at all.
Cheapest, fastest, and IMO userfriendliest.

I would only use "combined" connectors where it makes sense.
E.g. a parallel communications port will not be wired with individual wires
or connectors. A power supply is on the border. A combined connector would
be nice to prevent reversing, but then it is not much hassle to plug 2  
individual
connectors. I would not combine "unrelated" signals (e.g. a horror to  
debug).


If you want my advise forget about that. Leave your design as it is with  
solder pins/connectors
where now the wires are. Otherwise you make your PCBs HUGELY complicated,  
with very little gain.
If I were your customer i would prefer it simple, so i can make changes.  
Remember, your are
not making a consumer electronics device, you are dealing with  
professionals.

By the way i'm also planning to make a curve tracer some day. But it is  
very far down
on the list and i usually just crank up a circuit for the particular case  
needed.

ST

I'm just gonna toss out a few thoughts coming to the fore,  based on me 
working on all sorts of stuff over several decades,  mostly repairs...

On Friday 20 August 2004 03:41 pm, Thomas P. Gootee wrote:

> There are several possibilities that I have considered:
>
> 1) pin headers on each pcb, with ribbon cables running to similar headers
> on the front panel's new pcb, or

Pin headers are good reliable connectors,  particularly if shrouded connectors 
are used,  and if they're also using ejector levers there isn't much stress 
on the cabling.

> 2) card-edge connectors on the front panel pcb, along the bottom, that each
> of the three pcboards' edges could plug into, or

I think less well of card-edge connectors.  You'll have problems with tarnish 
on the card,  and lack of reliability eventually with the connectors over 
time.  Notice that card-edge was the way to go with the old 5.25" and 8" 
floppy drives,  and early hard drives as well.  Nowadays _all_ 3.5" floppy 
drives and all IDE and SCSI hard drives use pin connectors.  That should tell 
you something.  :-)

> 3) right-angle headers or sockets on each pcb, that would plug directly
> into straight headers or sockets on the front panel pcb (pin headers and
> sockets, or DIN, or even D-Sub), with NO CABLING necessary, or

Pin headers at both ends of the connection is workable,  provided you can 
arrange the layout of stuff to accomodate this without too much trouble,  but 
it's gonna be a real hassle to design,  compared to using cables.

> 4) another new board, a "motherboard", in the bottom of the enclosure, with
> card-edge sockets, along with a total redesign of the current boards'
> layouts, so they could be mounted vertically, in the MB's sockets, and a
> new front panel pcb that would also plug into a card-edge socket on the new
> motherboard, or

Putting aside card-edge for a minute (see above :-),  what you suggest here is 
called a backplane.  It's been used in a few computers,  and in other 
equipment,  both in instances where all connectors were the same,  and all 
signals were bussed (see the early Zenith Data Systems XT-class machines for 
example) and in earlier stuff where each connector was different and you 
could only plug one board in to one particular slot (see "Digital Group" 
early pre-PC computers for an example of this).  The biggest problem I see 
with this is that you don't want all signals bussed because there are likely 
to be different signals used on each board,  and the other way means that any 
changes makes for a redesign needed and difficulty in upgrades,  etc. should 
anything change in the future.  Personally I'd avoid this.

> 5) card-edge sockets on all the pcbs, with small pcbs that plug into them,
> with discrete wires or ribbon cables soldered to the small pcbs (i.e.
> hand-made custom card-edge-connector cabling, hehehe...),

See above comments about card-edge connectors.  This is also much more 
labor-intensive assembly and more places for things to go wrong.

> 6) pcb-mount terminal blocks with discrete wires, or

<shrug>

Terminal blocks are okay and I'd go that way if I were dealing with wiring 
that had to carry nontrivial levels of power (say more than a couple of 
hundred mA or so) but for the most part you won't need it.  Lots of potential 
for error here,  too.

> 7) something similar to #1, but with some as-yet-unknown (to me) connector
> and/or cabling types (I even considered pcb-mountable modular phone jacks
> and cabling).

Aside from a limited number of conductors these are reasonable,  and fairly 
cheap.  Not terribly robust mechanically,  but easy enough to crimp those 
connectors on.  Unless you need to start crossing wires,  etc.  They're 
probably cheaper than pin connectors,  but other than that I don't see that 
much of an advantage to going with them.

> Which of those (probably out of #1 through #4) sound "good"?

One thing you might consider in terms of using pin connectors is the 
possibility of using off-the-shelf cables,  such as 34 wires ("IDE cable") or 
50 wires ("SCSI cable"),  etc.

> One immediate "problem" I can foresee, with just adding a second side to
> each pcb and then running traces (on the "new" side of each board) to pin
> headers: Our pcb-making process is rudimentary and does NOT include the
> ability to make plated-through holes. SO, to have headers that are
> connected to the new top side traces, while the connectors are also sitting
> on the top sides of the boards, I wouldn't be able to solder the top side's
> trace directly to the headers' pins, since the headers sit right on the
> boards. So I'd have to make an extra row of holes next to each header row,
> that could have pins inserted that could be soldered on both sides. (I was
> thinking I might just use a single-row header, upside down with the longer
> pins halfway into the holes. It might be "ugly". But it would also provide
> handy test-points...).

Test points are good.  But you might also consider using a connector that has 
way more pins than you need and using a bunch of them for grounds.  This is 
what's typically the case with a lot of PC internal interconnects,  and it 
makes for better performance in terms of crosstalk etc. between the wires. 
Though I don't know how much of a problem that's likely to be in the 
equipment you're talking about.

> Many of the switches in the unit just happen to use groups of six
> connections. So, for many on-board and board-to-board "jumpers", short
> lengths (six or eight inches max, probably) of 6-conductor ribbon cables
> might be handy, although, changing to double-sided boards might ("should")
> eliminate that need.

Smallest connector you'll probably find is 10 pins,  I think,  unless you get 
the longer strips and cut them,  but I'm not sure about the cable connectors.

> The primary GOAL is still to make the unit easier, faster, and cheaper to
> assemble. SO, I really don't want to use cabling schemes that require a lot
> of time or expensive equipment, to assemble (IDC?). Socketed connections
> are preferred, so that units can be easily disassembled for repairs or
> board-level upgrades. If ribbon cables are used, I would prefer having
> pre-assembled cables available.

See above comment on that.  :-)

> I did buy a couple-hundred new IDE 40-pin cables (with three 2x20 sockets
> each), for $5!  And I got several hundred 40-pin breakable gold-plated
> single-row pin headers for about $10. And I got 300 2.5-inch-long 36-wire
> ribbon cables that have 36-pin single-row sockets on both ends, for $30
> including shipping, and 200 36-pin single-row gold-plated headers for about
> $5 or $10. (Actually, I got the *300* of the new IDE cables, for $5.99 plus
> $21.42 s/h.)

There you go...

> SO, I may end up cutting the IDE cables so they have just two sockets with
> about 8 inches of cable between them, and using those.  Or I may use the
> short 36-pin cables and single-row headers.
>
> However, I am ALREADY running into the problem of *possibly* not having
> enough ROOM on the new front-panel PCB, for that many large connectors.  SO
> I *STILL* probably need to find something smaller (fewer conductors), for
> the two smaller boards to use, to connect to the front panel PCB, and/or to
> the other boards.

Hm.

> ANOTHER IDEA:  If I could find a very large (and very cheap) surplus
> stockpile of ISA "RISER BOARDS" (or even 8-bit passive backplane boards, or
> somesuch) that have 5 or more slots, those could make PERFECT ready-made
> motherboards, to mount in the bottom of the case, with the slots parallel
> to the front panel. Then ALL of my boards could plug into the slots and all
> be connected together, including the front panel.  Of course, I could make
> my own similar motherboard-type boards, fairly easily, with available
> card-edge connectors. (But the large, new card-edge-connectors are usually
> quite expensive. Maybe I can find a large surplus lot of them...) But MAYBE
> there's a really low-cost stockpile of something similar, somewhere, which
> would certainly make things MUCH easier and faster and cheaper.

I have a few of those riser cards on hand that I was hoping to find a use for 
some time,  and you're welcome to those,  but I don't know about several 
hundred.  :-)  I had a guy come by with a load of "computer junk" the other 
day and declined to take the one Packard Bell machine that he had that was 
one of those boxes,  probably could've snagged another one,  but...

> There are also several connections to the rear panel, usually with only one
> or two wires, that I need to worry about. I am thinking of using either
> one- and two-wire pin headers and sockets, for those, or small terminal
> blocks of some type.  However, I still would LIKE to have all pre-assembled
> cables (i.e. sockets already on both ends of appropriate-length cabling.

For something like that I've seen some commercial gear that used different 
styles of connectors (all 2-pin) so you couldn't mix them up and plug 
something into the wrong place.  You could also handle that issue by setting 
the wire length to be only appropriate for where it's supposed to go and 
similar tricks.  Something to worry about,  anyway.

> Peak currents in some of the signal conductors could reach 1.5 Amps.
> However, most of those waveforms are triangular or sawtooth, making the
> average (DC-equivalent) current only HALF of the peak value.  But the main
> DC power supply rails MAY have to be connected from the separate power
> supply board to the other boards using discrete wiring that's screwed into
> terminal blocks, for that reason (max current-carrying capability).

Or at least something that's heavier-duty than pin connectors,  though it's of 
course possible to use several of those pins for this purpose.

The Osborne 1 computer had a weird custom board on their floppy drives, which 
was A and which was B was determined only by where the terminator position. 
This was before twists in cables and similar nonsense.  They also ran the 
power for those drives up through the ribbon cable,  to a card-edge 
connector.  There were reliability problems with those over time...

> Sorry to have blathered-on for so long, here!  If there's anything you can
> offer, I'm all ears!

Hopefully some of what I've kicked out here will be of some help.   I see a 
lot of different things being done in commercial gear manufactured over a 
long period of time,  from no connectors at all to a bunch of different 
alternatives.

If I were building something I think I'd probably tend to favor pin connectors 
for signals and something a little heavier for handling any kind of power,  
maybe a "pin connector" that's larger (0.156 spacing?) and that uses the 
square pins for a better contact.

**QUOTE
Which of those (probably out of #1 through #4) sound "good"?  
 
One immediate "problem" I can foresee, with just adding a second side
to each pcb and then running traces (on the "new" side of each board)
to pin headers: Our pcb-making process is rudimentary and does NOT
include the ability to make plated-through holes. SO, to have headers
that are connected to the new top side traces, while the connectors
are also sitting on the top sides of the boards, I wouldn't be able to
solder the top side's trace directly to the headers' pins, since the
headers sit right on the boards. So I'd have to make an extra row of
holes next to each header row, that could have pins inserted that
could be soldered on both sides. (I was thinking I might just use a
single-row header, upside down with the longer pins halfway into the
holes. It might be "ugly". But it would also provide handy
test-points...).
**ENDQUOTE


Thought I would mention...again...the possibility of using pin headers
on the *edge* of the board. No need to drill holes or worry about
soldering pins on both sides. Here's an illustration:
http://macetech.com/edgeheader.jpg

> Thought I would mention...again...the possibility of using pin headers
> on the *edge* of the board. No need to drill holes or worry about
> soldering pins on both sides. Here's an illustration:
> http://macetech.com/edgeheader.jpg
>

by the way that works really well with sub-d connectors.
(the solder-lug type, 1.5mm PCBs are a snug fit).
Ideal for small circuits like pic programmers and such.
If it is small enough the pcb will fit in the plug housing.

ST

> Pin headers are good reliable connectors,  particularly if shrouded  
> connectors
> are used,  and if they're also using ejector levers there isn't much  
> stress
> on the cabling.

agreed. especially if the second "foldback" clip is _not_ used with ribbon
cable headers the strain is too much. if the user pulls at the edge the  
outermost
wires are pulled out of the connector. the lever type is VERY neat.  
(remember
there are different lever length for "with second clip" and without.)


> I think less well of card-edge connectors.  You'll have problems with  
> tarnish
> on the card,  and lack of reliability eventually with the connectors over
> time.  Notice that card-edge was the way to go with the old 5.25" and 8"
> floppy drives,  and early hard drives as well.  Nowadays _all_ 3.5"  
> floppy
> drives and all IDE and SCSI hard drives use pin connectors.  That should  
> tell
> you something.  :-)

basically i agree, i distrust them. Though if you use drives for a example
i might point out that in home-pcs the PCI (and AGP, ISA,...) cards are  
edge
connectors. I wouldn't trust them, especially without gold plating.
If they get wet you have constant problems (even with gold plating). I have
a watercooled PC and i know what i talk about.

ST

I've been bitten by card edge connectors as well....
Avoid them.

As far as the front pcb, thats a lot of laminate, and
you may have to spend a preminum to get the proper
alignment of the pots bnc's and other connectors. You
might look at 2-3 discrete pcb's for the front panel
to cut down on laminate cost.

I've also been bitten by pin style pcb to pcb
interconnects. The key is to provide extra mechanical
support so the connectors are not subject to vibration
and shock, then they work fine.

Unless your volumes are really high, I've found it
beneficial to use MTA connectors and wiring harnesses.
One can set it up on a routing board, get a hand tool
for $200, and then hire a neighbor to build harnesses
for a few bucks. The cottage industry is well suited
to this type of work. Its a lot cheaper than having to
tool the board supports if you use pin connectors to
plug the boards together.

Cool unit!!! I'll keep it in mind. My curve tracer is
pretty crude.

Ron


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Date: Fri, 20 Aug 2004 22:03:36 +0200

   From: "Stefan Trethan" <stefan_trethan@...>
Subject: Re: RE: making vias (was: Re: Plating thruholes.)

On Fri, 20 Aug 2004 14:41:23 -0500, Thomas P. Gootee <tomg@...>  
wrote:

> Thanks, to everyone who replied so far, for the good suggestions and  
> information!
>
> This re-design is still in the very early stages. I don't know if this  
> is too off-topic. But I'll post a sort of summary of the different  
> board/connector options I'm considering (mostly copied from an email  
> that I sent to a friend, recently, about this stuff).  Maybe some of you  
> can set me straight, or offer some practical tips, or some ideas.
>


I didn't read all of your post but i will tell you a story a good teacher  
told me some
time ago.

He was working for a company making TVs, and had a new design to make.
Recently they had hired a guy which should make the units more reliable,  
by statistics and such.
He was to check all new designs.
Well, my teacher designed the new TV as usual with plug-in cards.
After he was done he showed it to the reliability guy to be checked.
This guy only asked him if he is mad using several hundred connections.
He told him he an forget about the plug-in cards because the statistics  
say they
will fail too often. That meant a major redesign of the unit of course.
That was the last Plug-in type TV he built, from then they only used  
single boards or
soldered connections.

so i wouldn't say connectors make things reliable.

Another issue is upgradeability. I expect every single one of your  
customers
to be well able to solder and even design circuits.
Do you really believe a PCB for all the front-plate elements is a good  
idea?
It would be MUCH harder to add an additional connector or something then.

If i were you i'd just put a solder pin in every wire pad. Then solder the
suitble pug to the wire and done. You can easily take it apart with no  
redesign at all.
Cheapest, fastest, and IMO userfriendliest.

I would only use "combined" connectors where it makes sense.
E.g. a parallel communications port will not be wired with individual wires
or connectors. A power supply is on the border. A combined connector would
be nice to prevent reversing, but then it is not much hassle to plug 2  
individual
connectors. I would not combine "unrelated" signals (e.g. a horror to  
debug).


If you want my advise forget about that. Leave your design as it is with  
solder pins/connectors
where now the wires are. Otherwise you make your PCBs HUGELY complicated,  
with very little gain.
If I were your customer i would prefer it simple, so i can make changes.  
Remember, your are
not making a consumer electronics device, you are dealing with  
professionals.

By the way i'm also planning to make a curve tracer some day. But it is  
very far down
on the list and i usually just crank up a circuit for the particular case  
needed.

ST

ST,

Thanks for the thoughtful reply.

I agree that connectors, sockets, etc, don't usually make things more reliable. What I meant by saying that they might make the unit more-reliable was really just that there might be a lower probability of wiring errors at the time of construction. The multitudes of wires can also make the construction tasks difficult, which probably tends to cause lower quality, since it can get very difficult to reach some of the solder lugs, etc, after lots of the wires are in place.

I also already knew that card-edge connectors are probably less-reliable than other types.  But I don't think that they are always unacceptable.  (And the architecture, using them, just seems so darned attractive and "clean", to me, hehe...)

You make a good point, if I understood correctly, about using individually-pluggable wires, with a single-pin on the pcb for each one.  I did read some posts in one of the pinball or arcade game newsgroups, or a website referenced there, about different types of connectors, where they were saying/claiming that crimp-type connectors for discrete wires are one of the most-reliable types (which includes wires with crimped-on pins that are then inserted/mounted into multi-connection sockets or plugs). They also claimed that soldering, in addition to crimping, is not necessary, and should probably even be avoided, since it might do some harm to the connector, or the wire/insulation, if not done perfectly.

I'm looking through my Mouser.com catalog, again, right now!

Regarding using a PCB for the front panel controls, etc: I see it as a *huge* benefit. The mass of wiring that results from the way it's done now is "a mess".  Adding a new control or something to the front panel design, later, wouldn't be too difficult, or, at least not difficult-enough to significantly offset the benefits of using a PCB, in my opinion.  And if some user wants to add their own control to the panel, later, in an existing instrument, well, they'll just have to find a way (There will also be some space between the panel and its pcb.). But that would be very rare, I think, and is not too much of a concern.

Regarding making a Curve Tracer (kind of a long story...):

MINE started out to be just for MY OWN USE, and was basically just one of the "quick and dirty" curve tracers, like the one described here: http://www.repairfaq.org/REPAIR/F_semitest.html#stqdc , i.e. just a small signal source and a few resistors.  

But I started adding "convenient" features, one by one, and then just kept on adding more and more to it: 

e.g. I also REALLY wanted to be able to see the whole "family" of curves, for a transistor, all at once, like on a "real" curve tracer. So I eventually figured out how to have a ramp "sweep" signal for the DUT, with a synchronized staircase signal for the base/gate.  And I needed multiple voltage rails, so I designed a boost-mode switching power supply board that takes 12 vdc and makes the plus and minus 18 vdc (variable, actually) needed by most of the ICs (and at up to 3 amps, total), and the +5 for CMOS ICs.  With all of that working, I decided I also needed to be able to "push some more amps" into the device under test (DUT). So I designed a power amplifier. And I wanted calibrated excitation-voltage levels for the DUT so I made the amp's gain switchable. Then I decided that the resistor networks required for switching the gain were kind of "ugly", so I designed a coool feedback control loop that sets the gain. 

I'm pretty proud of that feedback control loop gain-control circuit: It uses a Vactrol (VTL5C2) current-controlled resistor (basically just a photocell and LED encapsulated together). Since there are a discrete number of desired peak-to-peak output voltage levels, I used a TL1431IZ 0.4% 2.5v precision voltage reference to derive six DC voltages, equal to the six selectable peak output levels' 0-to-peak values. A frequency-compensated peak-detector/envelope-follower type of circuit continuously produces a quasi-DC voltage that's equal to the ACTUAL output's 0-to-peak value. That voltage is then subtracted from the selected DC reference voltage, to get an "error signal" voltage, which is used to drive current through the VTL5C2's LED, which sets the resistance that sets the amplifier's gain. 

The VTL5C2 is a pretty nifty device: Its resistance varies (non-linearly, though) from about 2 Megohms with no current through its LED to about 200 Ohms with 40 mA through its LED. And it has none of the "quirks" that you have to worry about when using an FET as a voltage-controlled resistor. (And bgmicro.com has them for $0.50 each.) 

The amplifier's gain can vary from 1 to about 101.  It uses a National LM1875T "opamp", which can easily push 3 or 4 amps from its' output, although I limit it to 1.5 Amps, in the Curve Tracer product.

I also added lots of other stuff, including instrumentation amplifiers to sense the voltage and current used for the x-y scope display, and inverters, buffers, and switching, etc, so I could display the current through ANY of the three DUT leads versus the voltage across ANY two of the DUT leads, and flip the displayed polarity of either of them at any time. And I added a range of frequencies for the sweep signal. And I added twelve selectable current-limiter resistances. And I added an option for a triangle waveform instead of a ramp, and an integrator to produce a quasi-sine waveform from the triangle. And so on and so on. And on and on and on...

So, *eventually*, I thought to myself, "Hey! OTHER people might like to have one of these, TOO!".  Of course, when a hobbyist designs and builds a piece of electronic equipment, especially if it's essentially the first time they've done a large self-designed project, then when it's all "finished", and works "perfectly", they've still maybe done only about **5%** of the work that's needed to make it into an actual "commercial product".  

Mine's also available in KIT form, which makes it even MORE work, in some ways, since I have to produce (AND keep *updated*) all of the construction diagrams, for component placement, wiring, mechanical stuff, etc, and assembly and alignment instructions, plus complete schematics, detailed parts lists, instrument-panels' artwork, etc etc. (all in "presentable" forms). And I have to do all of the sourcing and supplier stuff, keep a large parts and supplies inventory, make circuit boards, make apply-able instrument panel artwork, count parts and supplies into nice little multi-compartmented plastic kit-boxes, market and sell them, pack and ship them, support them, etc etc etc.  I'm also working on a "real" ops/service manual, which, eventually, is intended to be as good as the legendary older Tektronix manuals. (Hmmm...  Maybe I *AM* crazy...  Hehe...)

And I still have MANY, many things that I'd like to add, and change, in the Curve Tracer product. But, first, I want to "clean up" the current version, especially since I may eventually have it (or parts of it) mass-produced, maybe by a third party.  I've also got some other great electronic products "in the pipeline". But I think that I need to "get to the next level", first, so I can hire some people, to hopefully allow ME to spend my time on things where I can contribute the most, i.e. where any specialized abilities that I have might make the most difference, instead of on things that almost anyone could be doing.  I've been trying to "bootstrap" this business, starting with not much capital. But I may end up having to take on some investors, to be able to get where I want to be (quickly-enough, anyway).

Thank you, again, Stephan, very much, for your good suggestions!

And I am sorry that I blathered-on, for so long, *AGAIN*.  (This business has basically "taken over my life", as you can probably tell, hehe.  But it IS *quite* enjoyable...)

Cheers,

Tom Gootee

http://www.fullnet.com/u/tomg

-----------------------------------




[Non-text portions of this message have been removed]

> And I am sorry that I blathered-on, for so long, *AGAIN*.  (This
business has basically "taken over my life", as you can probably tell,
hehe.  But it IS *quite* enjoyable...)
> 
> Cheers,
> 
> Tom Gootee


I'm curious about how well you homegrown gadget-builders do. I have
quite a few ideas of my own sitting on the shelf, and have never been
able to get anyone to tell me how well their business actually does. I
don't want actual numbers, but basically there are three possible
ranges: 1. If I counted the effort I put in on these, I'm losing
money. 2. I'm breaking even or making a reasonable profit, not enough
to quit my day job but still worth it. 3. This is going so well that I
quit my day job and am concentrating on expanding my product line.

I just need to know what kind of a market is out there, I have no idea
how many people own soldering irons and are interested in building kits.

> You make a good point, if I understood correctly, about using  
> individually-pluggable wires, with a single-pin on the pcb for each  
> one.  I did read some posts in one of the pinball or arcade game  
> newsgroups, or a website referenced there, about different types of  
> connectors, where they were saying/claiming that crimp-type connectors  
> for discrete wires are one of the most-reliable types (which includes  
> wires with crimped-on pins that are then inserted/mounted into  
> multi-connection sockets or plugs). They also claimed that soldering, in  
> addition to crimping, is not necessary, and should probably even be  
> avoided, since it might do some harm to the connector, or the  
> wire/insulation, if not done perfectly.
>

Crimping is only good if you have the right tool and right force etc.
It is too easy to do it badly (like those silly "car electrics" crimp  
connectors
where you crimp right through the insulation with flimsy sheetmetal  
plyers).
Soldering is said to make the wire easy-breaking due to the heatin, maybe  
because
of that it shouldn't be done. However, i have no crimp tools and i trust  
my soldering
MUCH more.

> e.g. I also REALLY wanted to be able to see the whole "family" of  
> curves, for a transistor, all at once, like on a "real" curve tracer. So  
> I eventually figured out how to have a ramp "sweep" signal for the DUT,  
> with a synchronized staircase signal for the base/gate.

But you always only show one quadrant? or have you figured out a way of  
displaying
a four-quadrant graph? THAT would be nice...

>  And I needed multiple voltage rails, so I designed a boost-mode  
> switching power supply board that takes 12 vdc and makes the plus and  
> minus 18 vdc (variable, actually) needed by most of the ICs (and at up  
> to 3 amps, total), and the +5 for CMOS ICs.

IMO it is a bit of overkill to design a boost supply only to require a 12V  
supply
before it. I'd just use a +-18V supply then i guess, or make a switcher  
for 220V input.
(But you avoid mains voltage which is GOOD for a kit.)

> With all of that working, I decided I also needed to be able to "push  
> some more amps" into the device under test (DUT). So I designed a power  
> amplifier. And I wanted calibrated excitation-voltage levels for the DUT  
> so I made the amp's gain switchable. Then I decided that the resistor  
> networks required for switching the gain were kind of "ugly", so I  
> designed a coool feedback control loop that sets the gain.

I'm a bit surprised that that was needed. I was not aware that it is  
required to
keep the excitation voltage closely regulated. I kind of thought the scope  
display shows the
actual values anyway. (e.g. if i make a diode curve from 0 to 1A i can  
adjust the excitation
to show up as 1A at the scope - and don't care if it is 1.1A or 0.9A  
normally, as the divisions
show that clearly?).
Why is it required to be regulated?
(By the way i would probably have used a multipier to modulate the signal  
before the amplifier,
for ramp and triangle it is even easier if one uses opamps to generate the  
signal - just
limit the integrator voltage through diodes, you only need 1 more opamp to  
invert the voltage.
Have made a frequency and amplitude sweep/wobble sine/sqare generator once  
this way. only using opamps.
I avoid "fancy" solutions, because i can't pull the parts out of my  
storage then and must order.)


> I also added lots of other stuff, including instrumentation amplifiers  
> to sense the voltage and current used for the x-y scope display, and  
> inverters, buffers, and switching, etc, so I could display the current  
> through ANY of the three DUT leads versus the voltage across ANY two of  
> the DUT leads, and flip the displayed polarity of either of them at any  
> time.

I'll let the scope do that.
It is sensitive enough, and has diff. inputs to replace the  
instrumentation amps,
and invert also. The tek scopes are great for such stuff as i can just  
pull out the timebase
and plug in a fully-functional Y amplifier in it's place to generate the X  
axis.

> And I added a range of frequencies for the sweep signal. And I added  
> twelve selectable current-limiter resistances. And I added an option for  
> a triangle waveform instead of a ramp, and an integrator to produce a  
> quasi-sine waveform from the triangle. And so on and so on. And on and  
> on and on...

That is interesting. I didn't know a triangle can make anything similar to  
a sine
after a integrator. (considering the diff. of sine is sine). I'd like to  
discuss that.

agreed with the rest.
I want to suggest we carry this discussion to electronics_101, i'd like to  
continue it
but it is a bt OT here.
The curve tracer is in the back of my head and i'd like to learn what  
functions i need
to keep in mind. Maybe i buy a curve tracer plugin for my scope before i  
actually build one,
but you never know (and those plugins are RARE and expensive.)

ST

=== Roy,

=== THANKS for the excellent reply!

=== MY current responses are intermingled, BELOW, and marked with "==="s .

=== - Tom Gootee


Date: Fri, 20 Aug 2004 16:25:24 -0400

   From: "Roy J. Tellason" <rtellason@...>
Subject: Re: RE: making vias (was: Re: Plating thruholes.)

I'm just gonna toss out a few thoughts coming to the fore,  based on me 
working on all sorts of stuff over several decades,  mostly repairs...

=== Great!  "Repairs" usually tell the true tale...

On Friday 20 August 2004 03:41 pm, Thomas P. Gootee wrote:

> There are several possibilities that I have considered:
>
> 1) pin headers on each pcb, with ribbon cables running to similar headers
> on the front panel's new pcb, or

Pin headers are good reliable connectors,  particularly if shrouded connectors 
are used,  and if they're also using ejector levers there isn't much stress 
on the cabling.

> 2) card-edge connectors on the front panel pcb, along the bottom, that each
> of the three pcboards' edges could plug into, or

I think less well of card-edge connectors.  You'll have problems with tarnish 
on the card,  and lack of reliability eventually with the connectors over 
time.  Notice that card-edge was the way to go with the old 5.25" and 8" 
floppy drives,  and early hard drives as well.  Nowadays _all_ 3.5" floppy 
drives and all IDE and SCSI hard drives use pin connectors.  That should tell 
you something.  :-)

=== Point taken. But all of the PCs that I've seen still use card-edge connectors
=== for all of the CARDS,  i.e. the PCBs, in the expansion slots (e.g. ISA,
=== EISA, PCI, etc).  The "slots" are just card-edge connectors. I have
=== some that are over 15 years old that still work fine.  Also, I check out
=== and/or service or refurbish a lot of old Tektronix and other test equipment,
=== much of which uses card-edge connectors (e.g. Tek 7000 series scope
=== plug-ins and Tek TM500-series plug-ins). And those are heavily used, i.e.
=== they typically undergo MANY mating/unmating cycles over their lifetimes.
=== Occasionally there is a mechanical alignment problem, or somesuch, that
=== causes problems.  But not "too" many!  And a lot of that stuff is at least 20 or
=== 30 years old. (Then again, maybe all of the mating/unmating cycles HELPED
=== keep the card-edge connectors in better shape (by scraping the surfaces).

> 3) right-angle headers or sockets on each pcb, that would plug directly
> into straight headers or sockets on the front panel pcb (pin headers and
> sockets, or DIN, or even D-Sub), with NO CABLING necessary, or

Pin headers at both ends of the connection is workable,  provided you can 
arrange the layout of stuff to accomodate this without too much trouble,  but 
it's gonna be a real hassle to design,  compared to using cables.

=== Well, the boards are ALREADY sitting at right angles to the front panel,
=== with their edges just about in the right positions.  And I guess the on-board
=== part of the re-design would be about the same as if I were using cables.
=== It seems like eliminating anything, especially %$#! cables, would be
=== "a *GOOD* thing".
===
=== But HEY!  Couldn't I use the backplane/buss idea, but with pin headers and
=== sockets, instead of card-edge connectors?  I just REALLY like the idea of
=== using PCBs instead of wires and cables!

> 4) another new board, a "motherboard", in the bottom of the enclosure, with
> card-edge sockets, along with a total redesign of the current boards'
> layouts, so they could be mounted vertically, in the MB's sockets, and a
> new front panel pcb that would also plug into a card-edge socket on the new
> motherboard, or

Putting aside card-edge for a minute (see above :-),  what you suggest here is 
called a backplane.  It's been used in a few computers,  and in other 
equipment,  both in instances where all connectors were the same,  and all 
signals were bussed (see the early Zenith Data Systems XT-class machines for 
example) and in earlier stuff where each connector was different and you 
could only plug one board in to one particular slot (see "Digital Group" 
early pre-PC computers for an example of this).  The biggest problem I see 
with this is that you don't want all signals bussed because there are likely 
to be different signals used on each board,  and the other way means that any 
changes makes for a redesign needed and difficulty in upgrades,  etc. should 
anything change in the future.  Personally I'd avoid this.

=== Well, in general, you're probably right.  But, in THIS case, I think it would 
=== be great.  Basically, the one main board and the new front panel board have
=== LOTS of things that they need to share, like multiple 2P6T switches' wiring, and
=== a 1P12T switch's wiring, and a couple of 4P3T switches' wiring, and various
=== other controls' wiring, plus signals in and out, etc, and, of course, the power
=== supply rails, and all of the separate ground paths, and probably some other stuff
=== that I'm forgetting to mention.  Then there's the power amplifier board, which
=== only shares the wiring to one side of one of the same 2P6T switches, plus a
=== couple of i/o signal paths, and, of course, the power supply rails and some
=== ground paths. The third and last original board is just the power supply. And
=== all of the boards need to get power rails and separate ground paths, etc, from 
=== the power supply board. I just can't see *anything* wrong with putting them all
=== on a nice big buss.  Of course, the buss would have quite a few spare positions,
=== for future additions.  I'd probably also have at least one spare board position,
=== for the same reason (just so I wouldn't have to change it, if another board was
=== ever added).  
===
=== Am I missing something?? Or is my thinking wrong, about that, somehow??
===
=== I *DID* find some sources for fairly-inexpensive pcb-mount pin headers and
=== sockets, as well as pcb-mount card-edge connectors. So the cost of all of the
=== connectors, either pin-type or card-edge, for use on a parallel-buss pcb with 
=== 62 or more traces, and six card positions (I would only *need* 5, assuming my
=== main board is split into two boards so it would fit vertically into the same cabinet, 
=== which is only about 3 inches high, and assuming I added a new front panel pcb), 
=== could be in a range as low as $10.00 (for 100 quantities), especially if I used 
=== TWO headers and sockets that were each HALF the size I need for the main 
=== board and the front 
=== panel board, because then I could just use ONE of each for the two "little" boards.
===
=== (Of course, even $10 is a *significant* percentage-increase in the total parts cost
=== per unit.  But, heck, I can see RIGHT OFF THE BAT that it would save WAY more 
===than $10, in assembly labor costs alone (and *maybe* some in troubleshooting 
=== labor, etc, too).
===
=== That would, technically, make it into two busses, I guess. But the "backplane" 
=== board would be made so that the "extra" sockets could be added later, for the 
=== other card positions, if it ever became necessary, without changing the 
=== backplane board's layout.

> 5) card-edge sockets on all the pcbs, with small pcbs that plug into them,
> with discrete wires or ribbon cables soldered to the small pcbs (i.e.
> hand-made custom card-edge-connector cabling, hehehe...),

See above comments about card-edge connectors.  This is also much more 
labor-intensive assembly and more places for things to go wrong.

=== Yeah. That option was just mentioned "for the sake of completeness".

> 6) pcb-mount terminal blocks with discrete wires, or

<shrug>

Terminal blocks are okay and I'd go that way if I were dealing with wiring 
that had to carry nontrivial levels of power (say more than a couple of 
hundred mA or so) but for the most part you won't need it.  Lots of potential 
for error here,  too.

=== Yes.  The error potential is one of the main possible problems that I see 
=== with using any kind of single-wire connections, socketed or not, although
=== if they're socketed/removable, the errors WOULD be much easier to correct,
=== assuming they could be found...
===
=== BUT, there ARE "non-trivial" levels of current, in a few places. The
=== power amplifier board has to be able to push up to 1.5 Amps, through the
=== front panel connectors and on to the device under test (DUT). And the 
=== power supply board, obviously, has to supply that juice. In the current design,
=== those high-current signals also pass through the main curve tracer board, 
=== so they can have their currents and voltages sensed and fed to the 
=== instrumentation amplifiers, etc, that then produce the x-y outputs to the 
=== scope display. But, with the new front panel PCB, *probably* only the 
=== sensing-lines will need to go back to the main board.

> 7) something similar to #1, but with some as-yet-unknown (to me) connector
> and/or cabling types (I even considered pcb-mountable modular phone jacks
> and cabling).

Aside from a limited number of conductors these are reasonable,  and fairly 
cheap.  Not terribly robust mechanically,  but easy enough to crimp those 
connectors on.  Unless you need to start crossing wires,  etc.  They're 
probably cheaper than pin connectors,  but other than that I don't see that 
much of an advantage to going with them.

=== Yes. Easy to crimp. And cheap.  Might've been perfect as a cheap, easy
=== source for short 6-wire "jumpers". But, besides being a little "weird" in an
=== application like this one, it turns out that their connectors would just be 
=== way too BIG to have any hope of fitting onto the boards, as they are now.

> Which of those (probably out of #1 through #4) sound "good"?

One thing you might consider in terms of using pin connectors is the 
possibility of using off-the-shelf cables,  such as 34 wires ("IDE cable") or 
50 wires ("SCSI cable"),  etc.

=== Definitely!  See farther below.

> One immediate "problem" I can foresee, with just adding a second side to
> each pcb and then running traces (on the "new" side of each board) to pin
> headers: Our pcb-making process is rudimentary and does NOT include the
> ability to make plated-through holes. SO, to have headers that are
> connected to the new top side traces, while the connectors are also sitting
> on the top sides of the boards, I wouldn't be able to solder the top side's
> trace directly to the headers' pins, since the headers sit right on the
> boards. So I'd have to make an extra row of holes next to each header row,
> that could have pins inserted that could be soldered on both sides. (I was
> thinking I might just use a single-row header, upside down with the longer
> pins halfway into the holes. It might be "ugly". But it would also provide
> handy test-points...).

Test points are good.  But you might also consider using a connector that has 
way more pins than you need and using a bunch of them for grounds.  This is 
what's typically the case with a lot of PC internal interconnects,  and it 
makes for better performance in terms of crosstalk etc. between the wires. 
Though I don't know how much of a problem that's likely to be in the 
equipment you're talking about.

=== Good point.  There ARE some signals for which I'm planning to do that.

> Many of the switches in the unit just happen to use groups of six
> connections. So, for many on-board and board-to-board "jumpers", short
> lengths (six or eight inches max, probably) of 6-conductor ribbon cables
> might be handy, although, changing to double-sided boards might ("should")
> eliminate that need.

Smallest connector you'll probably find is 10 pins,  I think,  unless you get 
the longer strips and cut them,  but I'm not sure about the cable connectors.

=== Actually, many/most of the pin headers go down to 2 pins, I think.

> The primary GOAL is still to make the unit easier, faster, and cheaper to
> assemble. SO, I really don't want to use cabling schemes that require a lot
> of time or expensive equipment, to assemble (IDC?). Socketed connections
> are preferred, so that units can be easily disassembled for repairs or
> board-level upgrades. If ribbon cables are used, I would prefer having
> pre-assembled cables available.

See above comment on that.  :-)

=== Yup!

> I did buy a couple-hundred new IDE 40-pin cables (with three 2x20 sockets
> each), for $5!  And I got several hundred 40-pin breakable gold-plated
> single-row pin headers for about $10. And I got 300 2.5-inch-long 36-wire
> ribbon cables that have 36-pin single-row sockets on both ends, for $30
> including shipping, and 200 36-pin single-row gold-plated headers for about
> $5 or $10. (Actually, I got the *300* of the new IDE cables, for $5.99 plus
> $21.42 s/h.)

There you go...

=== Ebay can be good for that, as can the military surplus auctions. But I
=== ALWAYS run into TWO HUGE problems, doing it that way: 1) It takes
=== WAY too much time, just to FIND exactly the stuff I need, and even 
=== more time to find a large lot that's "a steal".  And, 2) It's a nightmare,
=== as far as having a reliable, i.e. repeatable source of supply.  
===
=== I've also seen some stuff that looks like it would be PERFECT, that was 
=== in fairly large qtys, and was VERY cheap.  But it's stuff that I've 
=== NEVER seen anywhere else.  So I definitely don't want to design it in...

> SO, I may end up cutting the IDE cables so they have just two sockets with
> about 8 inches of cable between them, and using those.  Or I may use the
> short 36-pin cables and single-row headers.
>
> However, I am ALREADY running into the problem of *possibly* not having
> enough ROOM on the new front-panel PCB, for that many large connectors.  SO
> I *STILL* probably need to find something smaller (fewer conductors), for
> the two smaller boards to use, to connect to the front panel PCB, and/or to
> the other boards.

Hm.

> ANOTHER IDEA:  If I could find a very large (and very cheap) surplus
> stockpile of ISA "RISER BOARDS" (or even 8-bit passive backplane boards, or
> somesuch) that have 5 or more slots, those could make PERFECT ready-made
> motherboards, to mount in the bottom of the case, with the slots parallel
> to the front panel. Then ALL of my boards could plug into the slots and all
> be connected together, including the front panel.  Of course, I could make
> my own similar motherboard-type boards, fairly easily, with available
> card-edge connectors. (But the large, new card-edge-connectors are usually
> quite expensive. Maybe I can find a large surplus lot of them...) But MAYBE
> there's a really low-cost stockpile of something similar, somewhere, which
> would certainly make things MUCH easier and faster and cheaper.

I have a few of those riser cards on hand that I was hoping to find a use for 
some time,  and you're welcome to those,  but I don't know about several 
hundred.  :-)  I had a guy come by with a load of "computer junk" the other 
day and declined to take the one Packard Bell machine that he had that was 
one of those boxes,  probably could've snagged another one,  but...

=== Thanks for the offer.  I just don't want to "design in" something that I
=== am not certain of having a large, fairly-reliable supply of.  I could probably
=== very-easily buy a few thousand identical PCs, from a military
=== surplus auction or two, probably for about $1000 to $1500 for each semi
=== trailer load, which is what I used to see them go for, all the time. But,
=== just having to go through the buying and transporting and storing and 
=== removing what I wanted and disposing of the rest would almost certainly
=== make it uneconomical, not to mention "WAY too much work". (It might
=== be different if I could find a decent way to use the whole case, and the
=== power supply, AND the motherboard slots, ALL left INTACT, where I
=== could just plug in my boards and mount my front panel stuff 
=== somewhere...  Hmm.... Whacky.  But maybe for some other product!)

> There are also several connections to the rear panel, usually with only one
> or two wires, that I need to worry about. I am thinking of using either
> one- and two-wire pin headers and sockets, for those, or small terminal
> blocks of some type.  However, I still would LIKE to have all pre-assembled
> cables (i.e. sockets already on both ends of appropriate-length cabling.

For something like that I've seen some commercial gear that used different 
styles of connectors (all 2-pin) so you couldn't mix them up and plug 
something into the wrong place.  You could also handle that issue by setting 
the wire length to be only appropriate for where it's supposed to go and 
similar tricks.  Something to worry about,  anyway.

=== Another very good idea.  Noted!

> Peak currents in some of the signal conductors could reach 1.5 Amps.
> However, most of those waveforms are triangular or sawtooth, making the
> average (DC-equivalent) current only HALF of the peak value.  But the main
> DC power supply rails MAY have to be connected from the separate power
> supply board to the other boards using discrete wiring that's screwed into
> terminal blocks, for that reason (max current-carrying capability).

Or at least something that's heavier-duty than pin connectors,  though it's of 
course possible to use several of those pins for this purpose.

=== Even the low-cost pin headers from jameco.com are rated at 1 amp per
=== pin. In this case, the 1.5 amps is the PEAK. But it's for ramp-type
=== waveforms. So the average "DC-equivalent" current would only be HALF 
=== of the 1.5 Amps.  And yes, the power supply rails (and grounds) for 
=== each board were going to be kept separate, anyway. And, as you said,
=== I could always run them doubled (or more), for any high-current ones.

The Osborne 1 computer had a weird custom board on their floppy drives, which 
was A and which was B was determined only by where the terminator position. 
This was before twists in cables and similar nonsense.  They also ran the 
power for those drives up through the ribbon cable,  to a card-edge 
connector.  There were reliability problems with those over time...

=== Is it possible that the newer card-edge connectors are better, now?
=== Well, never mind. Wherever I would have wanted to use card-edge, I
=== can use pin headers and sockets, instead.

> Sorry to have blathered-on for so long, here!  If there's anything you can
> offer, I'm all ears!

Hopefully some of what I've kicked out here will be of some help.   I see a 
lot of different things being done in commercial gear manufactured over a 
long period of time,  from no connectors at all to a bunch of different 
alternatives.

=== YES.  **QUITE** helpful.  Some great ideas, and stored wisdom! And
=== usually it also helps just to hash through it, with someone else, anyway.
===
=== I DEEPLY appreciate your taking the time and energy to respond,
=== so well, and your willingness to share your knowledge and experience.

If I were building something I think I'd probably tend to favor pin connectors 
for signals and something a little heavier for handling any kind of power,  
maybe a "pin connector" that's larger (0.156 spacing?) and that uses the 
square pins for a better contact.

=== 
=== Sounds right.  I might even use the PC disk-drive-type power cables,
=== for the heavier stuff.  (I just missed a chance to get a lot of something like
=== 500 brand new "Y"/splitter PC disk-drive power supply cables, on ebay,
=== that went for something like $10, total...!  Those could have connected
=== all three of the boards...  :-o )
===
=== Thanks again, *so* much!  You, and the others on this wonderful group,
=== are truly great.  If there's EVER anything that *I* can do, to help (any
=== of) YOU, please, just ASK!!
===
=== Highest regards,
===
=== Tom
===
=== Thomas P. (Tom) Gootee
=== tomg(AT)fullnet.com
=== http://www.fullnet.com/u/tomg
=== Jasper, Indiana, USA
===
===-------------------------------------



[Non-text portions of this message have been removed]

Just a couple more comments...

On Sunday 22 August 2004 10:04 am, Thomas P. Gootee wrote:

> > There are also several connections to the rear panel, usually with only
> > one or two wires, that I need to worry about. I am thinking of using
> > either one- and two-wire pin headers and sockets, for those, or small
> > terminal blocks of some type.  However, I still would LIKE to have all
> > pre-assembled cables (i.e. sockets already on both ends of
> > appropriate-length cabling.

> For something like that I've seen some commercial gear that used different
> styles of connectors (all 2-pin) so you couldn't mix them up and plug
> something into the wrong place.  You could also handle that issue by
> setting the wire length to be only appropriate for where it's supposed to
> go and similar tricks.  Something to worry about,  anyway.
>
> === Another very good idea.  Noted!

This would also probably involve making a "harness" for the wiring,  which may 
make things a bit more labor-intensive,  and may also prove to be a 
disadvantage when it comes to bundling stuff together that really shouldn't 
be.  I can't speak more to that without knowing more about what sort of 
signals are running around in that equipment...

<...>

> The Osborne 1 computer had a weird custom board on their floppy drives,
> which was A and which was B was determined only by where the terminator
> position. This was before twists in cables and similar nonsense.  They also
> ran the power for those drives up through the ribbon cable,  to a card-edge
> connector.  There were reliability problems with those over time...
>
> === Is it possible that the newer card-edge connectors are better, now?

No doubt they are,  at least once things progressed beyond ISA slots.  I have 
heard of some ISA connectors giving trouble,  and even encountered that 
*once* that I can recall (one of my XT-class MBs has a bit of black tape over 
one slot :-),  but have never heard of this being the case with PCI and AGP 
slots,  which use a different style of connector and a lot more pins.

<...>

> > If I were building something I think I'd probably tend to favor pin
> > connectors for signals and something a little heavier for handling any
> > kind of power, maybe a "pin connector" that's larger (0.156 spacing?) and
> > that uses the square pins for a better contact.

> Sounds right.  I might even use the PC disk-drive-type power cables, for the
> heavier stuff.  (I just missed a chance to get a lot of something like 500
> brand new "Y"/splitter PC disk-drive power supply cables, on ebay, that went
> for something like $10, total...!  Those could have connected all three of
> the boards...  :-o )

Now *those* have had their share of problems too.  Like the common Molex 
connectors,  reliability leaves something to be desired when you're looking 
at a female contact which consists of a bit of sheet metal that's going 
around a pin,  I don't know if this is a matter of what material is used for 
the contact or not.  There have been a few instances where I've had to take a 
small tool of some sort and close them up a bit,  after they'd opened up 
some...

The same is going to be true to some extent for DB-xx connectors,  though 
they're better at it as the positioning and size of the male pins seems to be 
more tightly controlled.

My preference for high reliability is contacts that have a "wiping" action, 
which can be seen in the "Centronics" style connectors used on the back of a 
printer,  which I've also seen in sizes of 24 and 50 pins and there are 
probably others.  Some "external" connections on SCSI cards seem to offer a 
miniature version of this,  like on my Adaptec 2940uw,  and the SCSI-wide 
connector is similar in a 68-pin version as well.  Some of the pin connectors 
I've seen/used over the years are based on a similar idea,  though I don't 
have part numbers handy.  The one half is a square pin (though sometimes 
round ones are used too),  and the other half is a bit of sheet metal that's 
"folded" several times (think of an "@" character :-) and has some continuous 
spring pressure holding it up against the other half.  This is in sharp 
contrast to a bit of sheet metal that's supposed to wrap itself around a pin.

Thomas,

I understand. <G> (And it's not just the first time you do it<G>)

I've had to "slip" the 500buck pcb drill/mill a few weeks for just 
the reasons you've mentioned here... Stuff IS trickling in; This week 
I'll get the 210 stepper motors for the first batch...

Still 500 bucks to those in THIS group, who express interest before 
month's end. And you WILL "see it" before month's end.

Re that "Kilobuck" inthe subject heading: The "list" price is going 
to be 995USD. (I'm lining up a distributor who will likely knock that 
back to the 800 I'd mentioned awhile back)

Ballendo

P.S. BTW, what you've read about the crimped connectors is EXACTLY 
right. Do NOT solder a crimped connector, thinking you'll "improve" 
the connection. All you'll really do is increase the chance, and 
decrease the time, to failure. (this assumes you have proper crimping 
tools. You "may" get better results from soldering than from POOR 
crimping. But you're still most likely better off with crimped only, 
UNLESS the connector is designed FOR soldering.)

>"Thomas P. Gootee" <tomg@f...> wrote:
>Thanks for the thoughtful reply.
<snip> where they were saying/claiming that crimp-type connectors for 
>discrete wires are one of the most-reliable types (which includes 
>wires with crimped-on pins that are then inserted/mounted into multi-
>connection sockets or plugs). They also claimed that soldering, in 
>addition to crimping, is not necessary, and should probably even be 
>avoided, since it might do some harm to the connector, or the 
>wire/insulation, if not done perfectly.<snip>

>So, *eventually*, I thought to myself, "Hey! OTHER people might like 
>to have one of these, TOO!".  Of course, when a hobbyist designs and 
>builds a piece of electronic equipment, especially if it's 
>essentially the first time they've done a large self-designed 
>project, then when it's all "finished", and works "perfectly", 
>they've still maybe done only about **5%** of the work that's needed 
>to make it into an actual "commercial product".  
> 
>Mine's also available in KIT form, which makes it even MORE work, in 
>some ways, since I have to produce (AND keep *updated*) all of the 
>construction diagrams, for component placement, wiring, mechanical 
>stuff, etc, and assembly and alignment instructions, plus complete 
>schematics, detailed parts lists, instrument-panels' artwork, etc 
>etc. (all in "presentable" forms). And I have to do all of the 
>sourcing and supplier stuff, keep a large parts and supplies 
>inventory, make circuit boards, make apply-able instrument panel 
>artwork, count parts and supplies into nice little multi-
>compartmented plastic kit-boxes, market and sell them, pack and ship 
>them, support them, etc etc etc.  I'm also working on a "real" 
>ops/service manual, which, eventually, is intended to be as good as 
>the legendary older Tektronix manuals. (Hmmm...  Maybe I *AM* 
>crazy...  Hehe...)
> 
>And I still have MANY, many things that I'd like to add, and change, 
>in the Curve Tracer product. But, first, I want to "clean up" the 
>current version, especially since I may eventually have it (or parts 
>of it) mass-produced, maybe by a third party.  I've also got some 
>other great electronic products "in the pipeline". But I think that 
>I need to "get to the next level", first, so I can hire some people, 
>to hopefully allow ME to spend my time on things where I can 
>contribute the most, i.e. where any specialized abilities that I 
>have might make the most difference, instead of on things that 
>almost anyone could be doing.  I've been trying to "bootstrap" this 
>business, starting with not much capital. But I may end up having to 
>take on some investors, to be able to get where I want to be 
>(quickly-enough, anyway).
<snip> 

>And I am sorry that I blathered-on, for so long, *AGAIN*.  (This 
>business has basically "taken over my life", as you can probably 
>tell, hehe.  But it IS *quite* enjoyable...)

>CyberMace wrote:
>I'm curious about how well you homegrown gadget-builders do. I have
>quite a few ideas of my own sitting on the shelf, and have never been
>able to get anyone to tell me how well their business actually does. 
>I don't want actual numbers, but basically there are three possible
>ranges: 1. If I counted the effort I put in on these, I'm losing
>money. 2. I'm breaking even or making a reasonable profit, not enough
>to quit my day job but still worth it. 3. This is going so well that 
>I quit my day job and am concentrating on expanding my product line.
> 
>I just need to know what kind of a market is out there, I have no 
>idea how many people own soldering irons and are interested in 
>building kits.

Garrett,

You'll find that there are folks --happily-- in all three of your 
described levels. That's the nature of business; and you won't really 
get an idea of how YOU'LL do... UNTIL, YOU DO!<G>

Reading your message I thought of several folks I've worked with, or 
hung out with; all with "electronics" products and "home business" 
thinking. Among them are members of all the levels you describe. Even 
on this list we have folks like embeddedtronics.com who say on their 
website that they're really just paying for the new projects with 
revenues from the old; and yet we have others who are most certainly 
doing something more akin to "production". Jeremy doing throughholes 
comes to mind (Hope I remembered that name correctly; apologies if 
not) And we have a member in South America who posted that he's 
making 200 boards a week...

Like the song from Everlast, which says "You know where it ends, yo
It usually depends on where you start..."

Not so much that you have money or not(which may be what the SONG is 
saying), but rather what you set out to do... Knowing what YOU are 
trying to get out of making, selling, marketing that thing--whatever 
it is-- is the first step.

I've designed and sold products my entire adult life(my entire life 
actually<G>) and sometimes I've fit your #1, other times I fit #2 or 
#3.

The second step is to DECIDE. Then take action on what you decide to 
try to accomplish. (Being willing to modify your decision based on 
results can be a good thing. OR a bad thing. Sometimes you're better 
off staying at level #2. A whole lot of folks have destroyed 
themselves by trying to grow something that really was suited to the 
level it was at.

As the song continues: "Then you really might know what it`s like"

Hope this helps,

Ballendo

P.S. I know of several guys who quit their day jobs to continue 
their "sideline business". A few are millionaires. Others are well-
off. And others are doing about what they were doing before; but 
enjoying it more. Just to mention three: One made pc boards at night 
as an engineer at Atari. Soon he was making boards for the whole 
engineering dept. Now he owns a very successful PC Board house in the 
CA mountains, and works three days a week. 

Another used to work in an electronics store, doing midi conversions 
for organs as a sideline, and last time I saw him he was driving a 
new truck<G>

Another is currently pedaling in preparation for the Athen 
paraOlympics--he's a cyclist-- and has a growing online business 
selling cnc related peripheral products. He hasn't left his day job 
yet; but it appears he has what it takes to do so in the not too 
distant future...

There are lots of others who've started small and now have major 
presence in the marketplace. Roger G of musclewires fame recently 
wrote a couple of articles about how a piece of wire from his hall 
closet ended up on Mars (in Servo or Nuts and Volts magazine)

You're wise to want to know how others are doing; But it ultimately 
won't say A THING about how YOU will do... From what I've seen of you 
online; you can make a good living selling stuff that you've 
designed. But realise that it is FAR more work in the beginning than 
working for someone else. 

Here are Four good books: 
The secret money machine by Don Lacaster (tinaja.com)
The E-myth by Michael Gerber
The Cashflow Quadrant by Robert Kiyosaki
Growing a Business by Paul Hawken

  

--- In Homebrew_PCBs@yahoogroups.com, "cybermace5" <cybermace5@y...> 
wrote:
> > And I am sorry that I blathered-on, for so long, *AGAIN*.  (This
> business has basically "taken over my life", as you can probably 
tell,
> hehe.  But it IS *quite* enjoyable...)
> > 
> > Cheers,
> > 
> > Tom Gootee
> 
> 
> I'm curious about how well you homegrown gadget-builders do. I have
> quite a few ideas of my own sitting on the shelf, and have never 
been
> able to get anyone to tell me how well their business actually 
does. I
> don't want actual numbers, but basically there are three possible
> ranges: 1. If I counted the effort I put in on these, I'm losing
> money. 2. I'm breaking even or making a reasonable profit, not 
enough
> to quit my day job but still worth it. 3. This is going so well 
that I
> quit my day job and am concentrating on expanding my product line.
> 
> I just need to know what kind of a market is out there, I have no 
idea
> how many people own soldering irons and are interested in building 
kits.

Tom,

Go to the Geckodrive yahoo group and have a look at the pictures in 
their file section. You can see what a "pin based" MB and cards setup 
looks like... (You may have to join the list to view the 
files/photos, but it'll be worth it, IMO.)

Hope this helps,

Ballendo 

--- In Homebrew_PCBs@yahoogroups.com, "Thomas P. Gootee" <tomg@f...> 
wrote:
> === Roy,
> 
> === THANKS for the excellent reply!
> 
> === MY current responses are intermingled, BELOW, and marked 
with "==="s .
> 
> === - Tom Gootee
> 
> 
> Date: Fri, 20 Aug 2004 16:25:24 -0400
>    From: "Roy J. Tellason" <rtellason@b...>
> Subject: Re: RE: making vias (was: Re: Plating thruholes.)
> 
> I'm just gonna toss out a few thoughts coming to the fore,  based 
on me 
> working on all sorts of stuff over several decades,  mostly 
repairs...
> 
> === Great!  "Repairs" usually tell the true tale...
> 
> On Friday 20 August 2004 03:41 pm, Thomas P. Gootee wrote:
> 
> > There are several possibilities that I have considered:
> >
> > 1) pin headers on each pcb, with ribbon cables running to similar 
headers
> > on the front panel's new pcb, or
> 
> Pin headers are good reliable connectors,  particularly if shrouded 
connectors 
> are used,  and if they're also using ejector levers there isn't 
much stress 
> on the cabling.
> 
> > 2) card-edge connectors on the front panel pcb, along the bottom, 
that each
> > of the three pcboards' edges could plug into, or
> 
> I think less well of card-edge connectors.  You'll have problems 
with tarnish 
> on the card,  and lack of reliability eventually with the 
connectors over 
> time.  Notice that card-edge was the way to go with the old 5.25" 
and 8" 
> floppy drives,  and early hard drives as well.  Nowadays _all_ 3.5" 
floppy 
> drives and all IDE and SCSI hard drives use pin connectors.  That 
should tell 
> you something.  :-)
> 
> === Point taken. But all of the PCs that I've seen still use card-
edge connectors
> === for all of the CARDS,  i.e. the PCBs, in the expansion slots 
(e.g. ISA,
> === EISA, PCI, etc).  The "slots" are just card-edge connectors. I 
have
> === some that are over 15 years old that still work fine.  Also, I 
check out
> === and/or service or refurbish a lot of old Tektronix and other 
test equipment,
> === much of which uses card-edge connectors (e.g. Tek 7000 series 
scope
> === plug-ins and Tek TM500-series plug-ins). And those are heavily 
used, i.e.
> === they typically undergo MANY mating/unmating cycles over their 
lifetimes.
> === Occasionally there is a mechanical alignment problem, or 
somesuch, that
> === causes problems.  But not "too" many!  And a lot of that stuff 
is at least 20 or
> === 30 years old. (Then again, maybe all of the mating/unmating 
cycles HELPED
> === keep the card-edge connectors in better shape (by scraping the 
surfaces).
> 
> > 3) right-angle headers or sockets on each pcb, that would plug 
directly
> > into straight headers or sockets on the front panel pcb (pin 
headers and
> > sockets, or DIN, or even D-Sub), with NO CABLING necessary, or
> 
> Pin headers at both ends of the connection is workable,  provided 
you can 
> arrange the layout of stuff to accomodate this without too much 
trouble,  but 
> it's gonna be a real hassle to design,  compared to using cables.
> 
> === Well, the boards are ALREADY sitting at right angles to the 
front panel,
> === with their edges just about in the right positions.  And I 
guess the on-board
> === part of the re-design would be about the same as if I were 
using cables.
> === It seems like eliminating anything, especially %$#! cables, 
would be
> === "a *GOOD* thing".
> ===
> === But HEY!  Couldn't I use the backplane/buss idea, but with pin 
headers and
> === sockets, instead of card-edge connectors?  I just REALLY like 
the idea of
> === using PCBs instead of wires and cables!
> 
> > 4) another new board, a "motherboard", in the bottom of the 
enclosure, with
> > card-edge sockets, along with a total redesign of the current 
boards'
> > layouts, so they could be mounted vertically, in the MB's 
sockets, and a
> > new front panel pcb that would also plug into a card-edge socket 
on the new
> > motherboard, or
> 
> Putting aside card-edge for a minute (see above :-),  what you 
suggest here is 
> called a backplane.  It's been used in a few computers,  and in 
other 
> equipment,  both in instances where all connectors were the same,  
and all 
> signals were bussed (see the early Zenith Data Systems XT-class 
machines for 
> example) and in earlier stuff where each connector was different 
and you 
> could only plug one board in to one particular slot (see "Digital 
Group" 
> early pre-PC computers for an example of this).  The biggest 
problem I see 
> with this is that you don't want all signals bussed because there 
are likely 
> to be different signals used on each board,  and the other way 
means that any 
> changes makes for a redesign needed and difficulty in upgrades,  
etc. should 
> anything change in the future.  Personally I'd avoid this.
> 
> === Well, in general, you're probably right.  But, in THIS case, I 
think it would 
> === be great.  Basically, the one main board and the new front 
panel board have
> === LOTS of things that they need to share, like multiple 2P6T 
switches' wiring, and
> === a 1P12T switch's wiring, and a couple of 4P3T switches' wiring, 
and various
> === other controls' wiring, plus signals in and out, etc, and, of 
course, the power
> === supply rails, and all of the separate ground paths, and 
probably some other stuff
> === that I'm forgetting to mention.  Then there's the power 
amplifier board, which
> === only shares the wiring to one side of one of the same 2P6T 
switches, plus a
> === couple of i/o signal paths, and, of course, the power supply 
rails and some
> === ground paths. The third and last original board is just the 
power supply. And
> === all of the boards need to get power rails and separate ground 
paths, etc, from 
> === the power supply board. I just can't see *anything* wrong with 
putting them all
> === on a nice big buss.  Of course, the buss would have quite a few 
spare positions,
> === for future additions.  I'd probably also have at least one 
spare board position,
> === for the same reason (just so I wouldn't have to change it, if 
another board was
> === ever added).  
> ===
> === Am I missing something?? Or is my thinking wrong, about that, 
somehow??
> ===
> === I *DID* find some sources for fairly-inexpensive pcb-mount pin 
headers and
> === sockets, as well as pcb-mount card-edge connectors. So the cost 
of all of the
> === connectors, either pin-type or card-edge, for use on a parallel-
buss pcb with 
> === 62 or more traces, and six card positions (I would only *need* 
5, assuming my
> === main board is split into two boards so it would fit vertically 
into the same cabinet, 
> === which is only about 3 inches high, and assuming I added a new 
front panel pcb), 
> === could be in a range as low as $10.00 (for 100 quantities), 
especially if I used 
> === TWO headers and sockets that were each HALF the size I need for 
the main 
> === board and the front 
> === panel board, because then I could just use ONE of each for the 
two "little" boards.
> ===
> === (Of course, even $10 is a *significant* percentage-increase in 
the total parts cost
> === per unit.  But, heck, I can see RIGHT OFF THE BAT that it would 
save WAY more 
> ===than $10, in assembly labor costs alone (and *maybe* some in 
troubleshooting 
> === labor, etc, too).
> ===
> === That would, technically, make it into two busses, I guess. But 
the "backplane" 
> === board would be made so that the "extra" sockets could be added 
later, for the 
> === other card positions, if it ever became necessary, without 
changing the 
> === backplane board's layout.
> 
> > 5) card-edge sockets on all the pcbs, with small pcbs that plug 
into them,
> > with discrete wires or ribbon cables soldered to the small pcbs 
(i.e.
> > hand-made custom card-edge-connector cabling, hehehe...),
> 
> See above comments about card-edge connectors.  This is also much 
more 
> labor-intensive assembly and more places for things to go wrong.
> 
> === Yeah. That option was just mentioned "for the sake of 
completeness".
> 
> > 6) pcb-mount terminal blocks with discrete wires, or
> 
> <shrug>
> 
> Terminal blocks are okay and I'd go that way if I were dealing with 
wiring 
> that had to carry nontrivial levels of power (say more than a 
couple of 
> hundred mA or so) but for the most part you won't need it.  Lots of 
potential 
> for error here,  too.
> 
> === Yes.  The error potential is one of the main possible problems 
that I see 
> === with using any kind of single-wire connections, socketed or 
not, although
> === if they're socketed/removable, the errors WOULD be much easier 
to correct,
> === assuming they could be found...
> ===
> === BUT, there ARE "non-trivial" levels of current, in a few 
places. The
> === power amplifier board has to be able to push up to 1.5 Amps, 
through the
> === front panel connectors and on to the device under test (DUT). 
And the 
> === power supply board, obviously, has to supply that juice. In the 
current design,
> === those high-current signals also pass through the main curve 
tracer board, 
> === so they can have their currents and voltages sensed and fed to 
the 
> === instrumentation amplifiers, etc, that then produce the x-y 
outputs to the 
> === scope display. But, with the new front panel PCB, *probably* 
only the 
> === sensing-lines will need to go back to the main board.
> 
> > 7) something similar to #1, but with some as-yet-unknown (to me) 
connector
> > and/or cabling types (I even considered pcb-mountable modular 
phone jacks
> > and cabling).
> 
> Aside from a limited number of conductors these are reasonable,  
and fairly 
> cheap.  Not terribly robust mechanically,  but easy enough to crimp 
those 
> connectors on.  Unless you need to start crossing wires,  etc.  
They're 
> probably cheaper than pin connectors,  but other than that I don't 
see that 
> much of an advantage to going with them.
> 
> === Yes. Easy to crimp. And cheap.  Might've been perfect as a 
cheap, easy
> === source for short 6-wire "jumpers". But, besides being a 
little "weird" in an
> === application like this one, it turns out that their connectors 
would just be 
> === way too BIG to have any hope of fitting onto the boards, as 
they are now.
> 
> > Which of those (probably out of #1 through #4) sound "good"?
> 
> One thing you might consider in terms of using pin connectors is 
the 
> possibility of using off-the-shelf cables,  such as 34 wires ("IDE 
cable") or 
> 50 wires ("SCSI cable"),  etc.
> 
> === Definitely!  See farther below.
> 
> > One immediate "problem" I can foresee, with just adding a second 
side to
> > each pcb and then running traces (on the "new" side of each 
board) to pin
> > headers: Our pcb-making process is rudimentary and does NOT 
include the
> > ability to make plated-through holes. SO, to have headers that are
> > connected to the new top side traces, while the connectors are 
also sitting
> > on the top sides of the boards, I wouldn't be able to solder the 
top side's
> > trace directly to the headers' pins, since the headers sit right 
on the
> > boards. So I'd have to make an extra row of holes next to each 
header row,
> > that could have pins inserted that could be soldered on both 
sides. (I was
> > thinking I might just use a single-row header, upside down with 
the longer
> > pins halfway into the holes. It might be "ugly". But it would 
also provide
> > handy test-points...).
> 
> Test points are good.  But you might also consider using a 
connector that has 
> way more pins than you need and using a bunch of them for grounds.  
This is 
> what's typically the case with a lot of PC internal interconnects,  
and it 
> makes for better performance in terms of crosstalk etc. between the 
wires. 
> Though I don't know how much of a problem that's likely to be in 
the 
> equipment you're talking about.
> 
> === Good point.  There ARE some signals for which I'm planning to 
do that.
> 
> > Many of the switches in the unit just happen to use groups of six
> > connections. So, for many on-board and board-to-board "jumpers", 
short
> > lengths (six or eight inches max, probably) of 6-conductor ribbon 
cables
> > might be handy, although, changing to double-sided boards might 
("should")
> > eliminate that need.
> 
> Smallest connector you'll probably find is 10 pins,  I think,  
unless you get 
> the longer strips and cut them,  but I'm not sure about the cable 
connectors.
> 
> === Actually, many/most of the pin headers go down to 2 pins, I 
think.
> 
> > The primary GOAL is still to make the unit easier, faster, and 
cheaper to
> > assemble. SO, I really don't want to use cabling schemes that 
require a lot
> > of time or expensive equipment, to assemble (IDC?). Socketed 
connections
> > are preferred, so that units can be easily disassembled for 
repairs or
> > board-level upgrades. If ribbon cables are used, I would prefer 
having
> > pre-assembled cables available.
> 
> See above comment on that.  :-)
> 
> === Yup!
> 
> > I did buy a couple-hundred new IDE 40-pin cables (with three 2x20 
sockets
> > each), for $5!  And I got several hundred 40-pin breakable gold-
plated
> > single-row pin headers for about $10. And I got 300 2.5-inch-long 
36-wire
> > ribbon cables that have 36-pin single-row sockets on both ends, 
for $30
> > including shipping, and 200 36-pin single-row gold-plated headers 
for about
> > $5 or $10. (Actually, I got the *300* of the new IDE cables, for 
$5.99 plus
> > $21.42 s/h.)
> 
> There you go...
> 
> === Ebay can be good for that, as can the military surplus 
auctions. But I
> === ALWAYS run into TWO HUGE problems, doing it that way: 1) It 
takes
> === WAY too much time, just to FIND exactly the stuff I need, and 
even 
> === more time to find a large lot that's "a steal".  And, 2) It's a 
nightmare,
> === as far as having a reliable, i.e. repeatable source of supply.  
> ===
> === I've also seen some stuff that looks like it would be PERFECT, 
that was 
> === in fairly large qtys, and was VERY cheap.  But it's stuff that 
I've 
> === NEVER seen anywhere else.  So I definitely don't want to design 
it in...
> 
> > SO, I may end up cutting the IDE cables so they have just two 
sockets with
> > about 8 inches of cable between them, and using those.  Or I may 
use the
> > short 36-pin cables and single-row headers.
> >
> > However, I am ALREADY running into the problem of *possibly* not 
having
> > enough ROOM on the new front-panel PCB, for that many large 
connectors.  SO
> > I *STILL* probably need to find something smaller (fewer 
conductors), for
> > the two smaller boards to use, to connect to the front panel PCB, 
and/or to
> > the other boards.
> 
> Hm.
> 
> > ANOTHER IDEA:  If I could find a very large (and very cheap) 
surplus
> > stockpile of ISA "RISER BOARDS" (or even 8-bit passive backplane 
boards, or
> > somesuch) that have 5 or more slots, those could make PERFECT 
ready-made
> > motherboards, to mount in the bottom of the case, with the slots 
parallel
> > to the front panel. Then ALL of my boards could plug into the 
slots and all
> > be connected together, including the front panel.  Of course, I 
could make
> > my own similar motherboard-type boards, fairly easily, with 
available
> > card-edge connectors. (But the large, new card-edge-connectors 
are usually
> > quite expensive. Maybe I can find a large surplus lot of them...) 
But MAYBE
> > there's a really low-cost stockpile of something similar, 
somewhere, which
> > would certainly make things MUCH easier and faster and cheaper.
> 
> I have a few of those riser cards on hand that I was hoping to find 
a use for 
> some time,  and you're welcome to those,  but I don't know about 
several 
> hundred.  :-)  I had a guy come by with a load of "computer junk" 
the other 
> day and declined to take the one Packard Bell machine that he had 
that was 
> one of those boxes,  probably could've snagged another one,  but...
> 
> === Thanks for the offer.  I just don't want to "design in" 
something that I
> === am not certain of having a large, fairly-reliable supply of.  I 
could probably
> === very-easily buy a few thousand identical PCs, from a military
> === surplus auction or two, probably for about $1000 to $1500 for 
each semi
> === trailer load, which is what I used to see them go for, all the 
time. But,
> === just having to go through the buying and transporting and 
storing and 
> === removing what I wanted and disposing of the rest would almost 
certainly
> === make it uneconomical, not to mention "WAY too much work". (It 
might
> === be different if I could find a decent way to use the whole 
case, and the
> === power supply, AND the motherboard slots, ALL left INTACT, where 
I
> === could just plug in my boards and mount my front panel stuff 
> === somewhere...  Hmm.... Whacky.  But maybe for some other 
product!)
> 
> > There are also several connections to the rear panel, usually 
with only one
> > or two wires, that I need to worry about. I am thinking of using 
either
> > one- and two-wire pin headers and sockets, for those, or small 
terminal
> > blocks of some type.  However, I still would LIKE to have all pre-
assembled
> > cables (i.e. sockets already on both ends of appropriate-length 
cabling.
> 
> For something like that I've seen some commercial gear that used 
different 
> styles of connectors (all 2-pin) so you couldn't mix them up and 
plug 
> something into the wrong place.  You could also handle that issue 
by setting 
> the wire length to be only appropriate for where it's supposed to 
go and 
> similar tricks.  Something to worry about,  anyway.
> 
> === Another very good idea.  Noted!
> 
> > Peak currents in some of the signal conductors could reach 1.5 
Amps.
> > However, most of those waveforms are triangular or sawtooth, 
making the
> > average (DC-equivalent) current only HALF of the peak value.  But 
the main
> > DC power supply rails MAY have to be connected from the separate 
power
> > supply board to the other boards using discrete wiring that's 
screwed into
> > terminal blocks, for that reason (max current-carrying 
capability).
> 
> Or at least something that's heavier-duty than pin connectors,  
though it's of 
> course possible to use several of those pins for this purpose.
> 
> === Even the low-cost pin headers from jameco.com are rated at 1 
amp per
> === pin. In this case, the 1.5 amps is the PEAK. But it's for ramp-
type
> === waveforms. So the average "DC-equivalent" current would only be 
HALF 
> === of the 1.5 Amps.  And yes, the power supply rails (and grounds) 
for 
> === each board were going to be kept separate, anyway. And, as you 
said,
> === I could always run them doubled (or more), for any high-current 
ones.
> 
> The Osborne 1 computer had a weird custom board on their floppy 
drives, which 
> was A and which was B was determined only by where the terminator 
position. 
> This was before twists in cables and similar nonsense.  They also 
ran the 
> power for those drives up through the ribbon cable,  to a card-edge 
> connector.  There were reliability problems with those over time...
> 
> === Is it possible that the newer card-edge connectors are better, 
now?
> === Well, never mind. Wherever I would have wanted to use card-
edge, I
> === can use pin headers and sockets, instead.
> 
> > Sorry to have blathered-on for so long, here!  If there's 
anything you can
> > offer, I'm all ears!
> 
> Hopefully some of what I've kicked out here will be of some help.   
I see a 
> lot of different things being done in commercial gear manufactured 
over a 
> long period of time,  from no connectors at all to a bunch of 
different 
> alternatives.
> 
> === YES.  **QUITE** helpful.  Some great ideas, and stored wisdom! 
And
> === usually it also helps just to hash through it, with someone 
else, anyway.
> ===
> === I DEEPLY appreciate your taking the time and energy to respond,
> === so well, and your willingness to share your knowledge and 
experience.
> 
> If I were building something I think I'd probably tend to favor pin 
connectors 
> for signals and something a little heavier for handling any kind of 
power,  
> maybe a "pin connector" that's larger (0.156 spacing?) and that 
uses the 
> square pins for a better contact.
> 
> === 
> === Sounds right.  I might even use the PC disk-drive-type power 
cables,
> === for the heavier stuff.  (I just missed a chance to get a lot of 
something like
> === 500 brand new "Y"/splitter PC disk-drive power supply cables, 
on ebay,
> === that went for something like $10, total...!  Those could have 
connected
> === all three of the boards...  :-o )
> ===
> === Thanks again, *so* much!  You, and the others on this wonderful 
group,
> === are truly great.  If there's EVER anything that *I* can do, to 
help (any

> === of) YOU, please, just ASK!!
> ===
> === Highest regards,
> ===
> === Tom
> ===
> === Thomas P. (Tom) Gootee
> === tomg(AT)fullnet.com
> === http://www.fullnet.com/u/tomg
> === Jasper, Indiana, USA
> ===
> ===-------------------------------------
> 
> 
> 
> [Non-text portions of this message have been removed]

As at the beginning of your project, month ago, I'm still interested.
Cristian


>Still 500 bucks to those in THIS group, who express interest before
>month's end. And you WILL "see it" before month's end.


  ----------

---
Outgoing mail is certified Virus Free.
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[Non-text portions of this message have been removed]

OK. Yeah.  The Molex "K.K." series has that type of pins.  

I happen to have some of those (or some that are extremely similar) on my desk, right now. Some guy on ebay was selling a "sample" set, with two M headers and two F shells for each size, that included 2, 3, 4, 5, 6, 7, 8, 9, 10, and 12 pins (although I also received two 14-pin F shells, as freebies), along with enough pins to fill all of the female connector shells. And I couldn't resist, since it seemed a lot quicker and easier than trying to order them all separately as free samples from Molex's site, and was pretty inexpensive ($10.50).  They just got here, not more than ten minutes ago.

They *DO* look good. Looking at the latest and greatest Mouser(.com) catalog (#619), I don't see an exact match for them, in the Molex K.K. series.  But they're pretty/very similar, and use almost-exactly the same types of crimp pins, in the female shells. (I guess I'll email the seller, to see if he knows the exact make and model, etc., in case I want to get more of them.)

These say "2510", on all of the F shells. They have M headers that have a basically-flat friction-lock type of "riser", on one side (i.e. parallel to the pins' common axial plane), which also includes detent-type locking "bumps". And the F shells have small "guide rails" that protrude out, most of the way up each edge of the side that contacts the headers' risers, to keep them aligned as they're plugged or unplugged, and to prevent any lateral movement.  They feel pretty SNUG, when connected, even WITHOUT any of the pins installed.  And the pins have basically the same-shape single-wipe contacts as the Molex K.K. series. They are basically flat springs, which come down from the wire/crimp end of the pin, bend about 135 degrees at the bottom, and go about 4 mm before bending back toward the rest of the pin at something less than 180 degrees, and continuing back to the vertical part of the pin, where they actually have a tab that goes THROUGH a small slot in the pin and then is bent, to retain it in the slot.

No time for more, right now. But thanks for all of your other comments, too!

Tom Gootee

http://www.fullnet.com/u/tomg

------------------------------------ ORIGINAL MESSAGE:

   Date: Sun, 22 Aug 2004 11:27:23 -0400

   From: "Roy J. Tellason" <rtellason@...>
Subject: Re: RE: making vias (was: Re: Plating thruholes.)
<snipped>
My preference for high reliability is contacts that have a "wiping" action, 
which can be seen in the "Centronics" style connectors used on the back of a 
printer,  which I've also seen in sizes of 24 and 50 pins and there are 
probably others.  Some "external" connections on SCSI cards seem to offer a 
miniature version of this,  like on my Adaptec 2940uw,  and the SCSI-wide 
connector is similar in a 68-pin version as well.  Some of the pin connectors 
I've seen/used over the years are based on a similar idea,  though I don't 
have part numbers handy.  The one half is a square pin (though sometimes 
round ones are used too),  and the other half is a bit of sheet metal that's 
"folded" several times (think of an "@" character :-) and has some continuous 
spring pressure holding it up against the other half.  This is in sharp 
contrast to a bit of sheet metal that's supposed to wrap itself around a pin.


[Non-text portions of this message have been removed]

On Monday 23 August 2004 03:36 pm, Thomas P. Gootee wrote:
> OK. Yeah.  The Molex "K.K." series has that type of pins.

I couldn't tell you what their designation is as my catalogs with molex stuff 
is pretty well buried someplace right now (got WAY too much stuff in this 
room :-).  But your description sounds to me like we're talking about pretty 
much the same thing...

<...>

> They are basically flat springs, which come down from the wire/crimp end of
> the pin, bend about 135 degrees at the bottom, and go about 4 mm before
> bending back toward the rest of the pin at something less than 180 degrees,
> and continuing back to the vertical part of the pin, where they actually
> have a tab that goes THROUGH a small slot in the pin and then is bent, to
> retain it in the slot.

Yep.  Easy to get out of the shell with a small screwdriver or other tool,  
too.

> No time for more, right now. But thanks for all of your other comments,
> too!

You're welcome,  and I'm glad I could be of some help.

>Still 500 bucks to those in THIS group, who express interest before
>month's end. And you WILL "see it" before month's end.

Expressing interest, expressing interest! :-)

-Johnathan

And I'm still trying very hard to raise the bucks!

Steve

--- In Homebrew_PCBs@yahoogroups.com, Johnathan Corgan <jcorgan@a...>
wrote:

> >Still 500 bucks to those in THIS group, who express interest before
> >month's end. And you WILL "see it" before month's end.
> 
> Expressing interest, expressing interest! :-)
> 
> -Johnathan

(SUCCESS!!)

For those who were interested in my project to redesign the pcbs in my Curve Tracer product, to eliminate the discrete, soldered wiring that connected the pcbs to the front panel, I have come up with what I think is a very good solution.

After deciding that a new PCB was needed, for the front panel controls and connectors to be mounted directly to, so that I could use some type of pluggable multi-conductor connectors, and then also considering the MANY possible interconnection options, and all of the connector types' pros and cons, etc, I finally realized what the solution should be.  (And I don't think anyone else ever suggested it to me, which amazes me. But, in this case, I had to start to "get my hands dirty", before I realized it, too.)

I had three pcboards, in the original unit.  They had wires, soldered to them, that were also soldered to the lugs on the front-panel controls.  And there were MANY wires.  Imagine FIVE rotary switches, with 12 or more solder lugs on each one, plus a few pots and a few 1P2T toggle switches, and some i/o connectors.  Not only did soldering the wires on both ends make it very tedious to ever remove a board, but, all of those wires made it almost impossible to even SEE the boards, or anything else, inside the unit.

After considering many different possible ways to "tame the tangle", and getting MANY good suggestions, and quite an education, from members of this (and other) groups, I started playing with "layout considerations", to try to get an idea of what could and should be done, to facilitate using SOME type of better interconnect strategy.

However, I soon realized that only the MAIN board was really in need of any attention.  The main board had at least SIXTY-something wires that went to the instrument panel's controls and connectors.  The other two boards had only nine, and two, respectively.

Then, it HIT me:  WHY put a whole new PCB in, parallel to the front panel, and change all of the controls to pcb-mount types, and then use that pcb just to run trace-busses to multi-wire connectors, to go to the other boards, when I could...

(gasp!)

just MOVE the whole main board ONTO the new front panel PCB?!!  

*NOW* there are almost NO wires *OR* connectors needed!  And no need to worry about their reliability, or errors made installing the old discrete wiring, etc etc.

The main board was 4x6 inches.  The new "panel" board is about 3 x 9 inches.   Perfect!

It's a *beautiful* thing.  For example: the circuitry that's associated with each rotary switch is built right around each switch's pins.  There was just BARELY enough room, on the board. But I made it all fit, eventually, and even improved it as I did so.  It ended up being almost a total re-layout job, for about two-thirds of it.  But it seems to have been well worth it!  It's definitely the prettiest broad I've ever laid (...er, I meant "board", hehe). I can't wait to actually warm one up and give'er a try.

This will also eliminate about five or six crowded pages of wiring diagrams from the kit-version's assembly instructions (which is good for me, too, since I will now no longer have to maintain those pages' artwork). Plus. I eliminated the cost of including most of the wire, from the cost of each kit (including many on-board wires that were also eliminated), which is probably on the order of 1% to 2% of the total parts cost.

Even better, I estimate that the construction time will be cut by almost ONE THIRD. (There are probably also too many other potential benefits to try to discuss them all, here.)

Thanks again, VERY much, to everyone who shared suggestions, comments, hints, tips,information, etc.

Regards,

Tom Gootee

http://www.fullnet.com/u/tomg


[Non-text portions of this message have been removed]

> (gasp!)
>
> just MOVE the whole main board ONTO the new front panel PCB?!!
>

Oh, sorry, should i have mentioned i do that most of the time? ;-)

Sometimes the circuit is really too complex, and you need more space.
Or you want a "big" machine with small panel area.
(example: tek 7000 scopes... look at the mechanical challenges they solved!
NOBODY could afford that sort of thing today. These guys did some amazing
work.)
where were we? the space...
if you haven't got enough space you can simply place a straight  
header/socket
connector on the PCB and "sandwich" a second board behind he first.
Very rigid still very slim.


ST

> And you WILL "see it" before month's end.

Any pictures yet ?

Steve

I am not an expert in PCB production and despite that I am interested
in circuit layout and design.  About a year ago, not really knowing
anything I delved into this topic and attempted to make my own PCB
board.  

At the time I had an Epson Stylus 600 (I now had the 825 model) and I
bought some Ink Jet transparency paper.  I also built my own 2 sided
UV exposure frame for about 200 bucks. No vacuum, just a piece of
glass and an area sectioned off with double sided window foam to put
the tranparencies and the PCB to expose.  I had 4 UV lights on each
side to expose the board. 

I can honestly say that my first attempt (EVER) was a smashing
success.  My first design was a two layer 8 bit I/O IDE card with
about 7 IC chips on it.  I showed a hardware engineer freind of mine
the results and he was impressed after I gave him the lowdown on how I
did it.  I am thinking the spec was at 7 mils, but please dont quote
me on that, like I said I am no expert.  There is a lot more to tell
about the process but with the equipment I had available it took me
about 1.5 hrs to produce the board including drilling 100 holes.  No
thru-plating or silkscreening at this point.

You may not be able to produce extremely tight tolerances with this
method but I can absolutely attest to the quality of a simple PCB, it
looks pretty professional.  If you are going to do something complex
you are probably going to send it out to a board house anyway.  I
think for the average simple board, this method is very cheap and easy.

Any update on this machine?

--- In Homebrew_PCBs@yahoogroups.com, "ballendo" <ballendo@y...> 
wrote:
> Thomas,
> 
> I understand. <G> (And it's not just the first time you do it<G>)
> 
> I've had to "slip" the 500buck pcb drill/mill a few weeks for just 
> the reasons you've mentioned here... Stuff IS trickling in; This 
week 
> I'll get the 210 stepper motors for the first batch...
> 
> Still 500 bucks to those in THIS group, who express interest 
before 
> month's end. And you WILL "see it" before month's end.
> 
> Re that "Kilobuck" inthe subject heading: The "list" price is 
going 
> to be 995USD. (I'm lining up a distributor who will likely knock 
that 
> back to the 800 I'd mentioned awhile back)
> 
> Ballendo
> 
> P.S. BTW, what you've read about the crimped connectors is EXACTLY 
> right. Do NOT solder a crimped connector, thinking 
you'll "improve" 
> the connection. All you'll really do is increase the chance, and 
> decrease the time, to failure. (this assumes you have proper 
crimping 
> tools. You "may" get better results from soldering than from POOR 
> crimping. But you're still most likely better off with crimped 
only, 
> UNLESS the connector is designed FOR soldering.)
> 
> >"Thomas P. Gootee" <tomg@f...> wrote:
> >Thanks for the thoughtful reply.
> <snip> where they were saying/claiming that crimp-type connectors 
for 
> >discrete wires are one of the most-reliable types (which includes 
> >wires with crimped-on pins that are then inserted/mounted into 
multi-
> >connection sockets or plugs). They also claimed that soldering, 
in 
> >addition to crimping, is not necessary, and should probably even 
be 
> >avoided, since it might do some harm to the connector, or the 
> >wire/insulation, if not done perfectly.<snip>
> 
> >So, *eventually*, I thought to myself, "Hey! OTHER people might 
like 
> >to have one of these, TOO!".  Of course, when a hobbyist designs 
and 
> >builds a piece of electronic equipment, especially if it's 
> >essentially the first time they've done a large self-designed 
> >project, then when it's all "finished", and works "perfectly", 
> >they've still maybe done only about **5%** of the work that's 
needed 
> >to make it into an actual "commercial product".  
> > 
> >Mine's also available in KIT form, which makes it even MORE work, 
in 
> >some ways, since I have to produce (AND keep *updated*) all of 
the 
> >construction diagrams, for component placement, wiring, 
mechanical 
> >stuff, etc, and assembly and alignment instructions, plus 
complete 
> >schematics, detailed parts lists, instrument-panels' artwork, etc 
> >etc. (all in "presentable" forms). And I have to do all of the 
> >sourcing and supplier stuff, keep a large parts and supplies 
> >inventory, make circuit boards, make apply-able instrument panel 
> >artwork, count parts and supplies into nice little multi-
> >compartmented plastic kit-boxes, market and sell them, pack and 
ship 
> >them, support them, etc etc etc.  I'm also working on a "real" 
> >ops/service manual, which, eventually, is intended to be as good 
as 
> >the legendary older Tektronix manuals. (Hmmm...  Maybe I *AM* 
> >crazy...  Hehe...)
> > 
> >And I still have MANY, many things that I'd like to add, and 
change, 
> >in the Curve Tracer product. But, first, I want to "clean up" the 
> >current version, especially since I may eventually have it (or 
parts 
> >of it) mass-produced, maybe by a third party.  I've also got some 
> >other great electronic products "in the pipeline". But I think 
that 
> >I need to "get to the next level", first, so I can hire some 
people, 
> >to hopefully allow ME to spend my time on things where I can 
> >contribute the most, i.e. where any specialized abilities that I 
> >have might make the most difference, instead of on things that 
> >almost anyone could be doing.  I've been trying to "bootstrap" 
this 
> >business, starting with not much capital. But I may end up having 
to 

> >take on some investors, to be able to get where I want to be 
> >(quickly-enough, anyway).
> <snip> 
> >And I am sorry that I blathered-on, for so long, *AGAIN*.  (This 
> >business has basically "taken over my life", as you can probably 
> >tell, hehe.  But it IS *quite* enjoyable...)

Quite true!! I could not get the transparants well: grey-ish, 
striping, etc. I found and read this post and it's now ok. Simply set 
my Epson Stylus 740 to "Glossy Photopaper" and "Color", printed on a 
deskjet transparant. It takes a while but it's perfect, much more 
black than a laserprinter. Great advise, thanks!
Regards,
Dirk

--- In Homebrew_PCBs@yahoogroups.com, mpdickens <md30022@y...> wrote:

> A member of another mailing list I am a member of
> found the following in a archive. Further, he tested
> and it worked as advertised:
> 
> I have been dealing with a development effort for a
> circuit that my company is developing. In order to get
> fast turnaround of boards for testing, I needed a way
> to make high quality circuit boards (multilayer) in
> under 8 hours. Cost from commercial board houses for
> 24 hour turnaround was in the range of $2000-$3000 per
> design.  In my case, I had to also develope plating
> systems and through-hole activation, fast etching, and
> a hot 20 ton press which I built by converting a shop
> press from harbor freight and adding a temperature
> controller and heating elements.  etc.
> 
> For ATM purposes, 2 sided boards can be made for a
> minimal expense.
> 
> Because many on this list make their own circuit
> boards on occassion (for stepper circuits and camera
> circuits), I thought I would share my experience
> with the group.
> 
> I am currently producing 4, 6 and 8 layer circuit
> boards using equipment now in my basement. Granted my
> basement looks like a chamber of horrors, but I
> suspect this is true for many on this list. Eight mil
> traces and lands are now easily doable and I am
> holding +/- 2 mil registration.
> 
> The greatest roadblock to producing good circuit
> boards was getting good artwork on a transparency.  In
> that regard, I have made several discoveries which are
> not immediately intuitive.
> 
> First, getting really good artwork for the spec above
> is not possible with a laser printer. Phase error
> creeps in and even for printers claiming 1200
> DPI the accuracy just isn't there.  I tested this with
> several models of HP printers including the 2000
> series and the 4000 series.
> 
> In addition, the toner is just not dark enough.  You
> end up having to underexpose the photoresist in order
> to get good removal and then you have a problem with
> undercured photoresist that will not tent over holes
> and whose sides are weak. Further the developing
> process just trashes the underexposed resist.
> 
> I finally decided to try an inkjet printer.  After
> some research looking for a printer that supported
> high resolution in black, I purchased a Canon.
> Initially, I purchased the S300 but it turned out that
> clever marketing made is sound like it supported high
> res black.  In reality, the black was only 600 DPI
> like every other printer...  Not enough resolution.  I
> then tried the S800, which did support 2400 x 1200 DPI
> in color and in Black - the only printer that
> supported high resolution black printing. Experiments
> with
> this printer unfortunately revealed the problem that
> most people have with bubble jets.  The black is
> simply not dark enough in UV.  This despite the fact
> that it was a pigment based ink.
> 
> I did have moderate success stacking tranparenies. 
> This allowed me to increase the exposure time, but
> because only the first transparency was ink down (the
> second had to have a full 5 mil separation for the
> thickness of the first transparency, the edges were
> not very clean.
> 
> I then had a brainstorm, I realized that my UV filters
> for my flourescent lighting were amber.  I decided to
> try other colors... I quickly discovered that yellow
> was just as dark (in UV) as black. Disappointed that
> it was not darker, I began thinking about ways I could
> change the formulation of the ink to include a
> coreactive UV blocking chemical. I started searching
> the net when I discovered that ink fading as a result
> of UV is a real problem for photography. To my
> surprise, my printer already contained an ink that
> was UV blocking.  All I had to do was tell the printer
> that it was printing on high resolution photopaper. 
> This automatically switched cartridges to the PC
> (Photo Cyan) and PM (Photomagenta). Yellow remains the
> same because yellow only fades to yellow.
> 
> In any case, once I did that, I was able to fully
> expose the Photoresist. In comparing a foil blocked
> section and a photo ink exposed section there
> was little difference. Moreover, in testing artwork
> created by a real photoplotter (costing $200,000). 
> There was no difference. The only difference was that
> I settled on "GREEN" as being the color that was best.
> This selected the darkness of yellow in UV and the
> chemical UV blocking in Photo Cyan to produce a very
> dark black in UV and a pretty green in visible... :-)
> 
> Perfect exposures!  That along with unbelievable
> resolution of these printers make for a killer
> combination for producing your own artwork and
> consequently your own circuit boards.
> 
> The bottom line is this. You DON'T want a printer with
> a dark black! Forget whether it is pigment based ink
> or dye based ink. That is all irrelavent, none of them
> are going to be dark enough.
> 
> You want a PHOTO printer with PHOTO ink.  Further ALL
> photoprinters have high resolution in color!  Even the
> cheap ones ($100)! Just make sure a photo ink is
> available either from the manufacturer or for an ink
> refiller. All photo ink is, is ink with UV blocking
> added so the photos you print don't fade.
> 
> What will the photoplotter companies do???
> 
> Armed with this information, there is no reason
> everyone on this list does not do steves killer mod
> for the Philips Vesta camera or the many circuits
> for telescope motorization and tracking.
> 
> 
> Best
> 
> Marvin Dickens
> Alpharetta, Georgia
> 
> =====
> Registered Linux User No. 80253
> If you use linux, get counted at: 
> http://www.linuxcounter.org
> 
> 
> 		
> __________________________________
> Do you Yahoo!?
> Yahoo! Mail - 50x more storage than other providers!
> http://promotions.yahoo.com/new_mail

........ I settled on "GREEN" as being the color that was best........

Firstly, thanks for saving a bunch of projects.
Re Green:
This is a dumb question I know but how much green?
The program's color editor can select 0 to 255 green in RGB mode and 0 
to 100% Cyan and Magenta  (a dark green) in CMYK. Is the latter the 
right color?
Terry M

Should have stated the colors in CMYK as Yellow and Cyan.
TM

The RGB green is probably just a "color corrected version" and will have
different percentages (i.e. less ink)

I would guess that the 100% cyan + 100% magenta will give you the most ink.

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/ 

> -----Original Message-----
> From: Terry Mickelson [mailto:tmdslca@...] 
> Sent: Thursday, February 03, 2005 12:26 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: Injet printers, 
> transparencies and UV light...
> 
> 
> 
> ........ I settled on "GREEN" as being the color that was best........
> 
> Firstly, thanks for saving a bunch of projects.
> Re Green:
> This is a dumb question I know but how much green?
> The program's color editor can select 0 to 255 green in RGB 
> mode and 0 
> to 100% Cyan and Magenta  (a dark green) in CMYK. Is the latter the 
> right color?
> Terry M

Every desktop printer driver only accepts RGB data. So if you work in
CMYK and print from it, your program first converts it to RGB.

Add to that, in most programs even if you set it to 100% anything CMYK
it will set it back to what it thinks can be printed.

The key here anyway is to get the -photo- cyan and magenta inks
printing. Those are the ones with UV protectant in them. So a light
green would be better, as it doesn't need to use the lighter photo
inks when printing dark green.

Why not print some strips that shade from dark to light green, and
with differing shades and expose and see what works best?

Steve Greenfield

--- In Homebrew_PCBs@yahoogroups.com, "Dave Hylands" <dhylands@b...>
wrote:
> The RGB green is probably just a "color corrected version" and will have
> different percentages (i.e. less ink)
> 
> I would guess that the 100% cyan + 100% magenta will give you the
most ink.

> 
> --
> Dave Hylands
> Vancouver, BC, Canada
> http://www.DaveHylands.com/ 
> 
> > -----Original Message-----
> > From: Terry Mickelson [mailto:tmdslca@t...] 
> > ........ I settled on "GREEN" as being the color that was best........
> > 
> > Firstly, thanks for saving a bunch of projects.
> > Re Green:
> > This is a dumb question I know but how much green?
> > The program's color editor can select 0 to 255 green in RGB 
> > mode and 0 
> > to 100% Cyan and Magenta  (a dark green) in CMYK. Is the latter the 
> > right color?
> > Terry M

Hi, I have excellent results with a HP DJ960C printing in black
directly from the Boardmaker PCB design program.
The printhead MUST be in excellent condition as stripes are a hell of
a problem.
ELSO


--- In Homebrew_PCBs@yahoogroups.com, "Dirk F Ganzinga" <dfg1955@y...>
wrote:
> 
> Quite true!! I could not get the transparants well: grey-ish, 
> striping, etc. I found and read this post and it's now ok. Simply
set 
> my Epson Stylus 740 to "Glossy Photopaper" and "Color", printed on
a 
> deskjet transparant. It takes a while but it's perfect, much more 
> black than a laserprinter. Great advise, thanks!
> Regards,
> Dirk
> 
> --- In Homebrew_PCBs@yahoogroups.com, mpdickens <md30022@y...>
wrote:

> > A member of another mailing list I am a member of
> > found the following in a archive. Further, he tested
> > and it worked as advertised:
> > 
> > I have been dealing with a development effort for a
> > circuit that my company is developing. In order to get
> > fast turnaround of boards for testing, I needed a way
> > to make high quality circuit boards (multilayer) in
> > under 8 hours. Cost from commercial board houses for
> > 24 hour turnaround was in the range of $2000-$3000 per
> > design.  In my case, I had to also develope plating
> > systems and through-hole activation, fast etching, and
> > a hot 20 ton press which I built by converting a shop
> > press from harbor freight and adding a temperature
> > controller and heating elements.  etc.
> > 
> > For ATM purposes, 2 sided boards can be made for a
> > minimal expense.
> > 
> > Because many on this list make their own circuit
> > boards on occassion (for stepper circuits and camera
> > circuits), I thought I would share my experience
> > with the group.
> > 
> > I am currently producing 4, 6 and 8 layer circuit
> > boards using equipment now in my basement. Granted my
> > basement looks like a chamber of horrors, but I
> > suspect this is true for many on this list. Eight mil
> > traces and lands are now easily doable and I am
> > holding +/- 2 mil registration.
> > 
> > The greatest roadblock to producing good circuit
> > boards was getting good artwork on a transparency.  In
> > that regard, I have made several discoveries which are
> > not immediately intuitive.
> > 
> > First, getting really good artwork for the spec above
> > is not possible with a laser printer. Phase error
> > creeps in and even for printers claiming 1200
> > DPI the accuracy just isn't there.  I tested this with
> > several models of HP printers including the 2000
> > series and the 4000 series.
> > 
> > In addition, the toner is just not dark enough.  You
> > end up having to underexpose the photoresist in order
> > to get good removal and then you have a problem with
> > undercured photoresist that will not tent over holes
> > and whose sides are weak. Further the developing
> > process just trashes the underexposed resist.
> > 
> > I finally decided to try an inkjet printer.  After
> > some research looking for a printer that supported
> > high resolution in black, I purchased a Canon.
> > Initially, I purchased the S300 but it turned out that
> > clever marketing made is sound like it supported high
> > res black.  In reality, the black was only 600 DPI
> > like every other printer...  Not enough resolution.  I
> > then tried the S800, which did support 2400 x 1200 DPI
> > in color and in Black - the only printer that
> > supported high resolution black printing. Experiments
> > with
> > this printer unfortunately revealed the problem that
> > most people have with bubble jets.  The black is
> > simply not dark enough in UV.  This despite the fact
> > that it was a pigment based ink.
> > 
> > I did have moderate success stacking tranparenies. 
> > This allowed me to increase the exposure time, but
> > because only the first transparency was ink down (the
> > second had to have a full 5 mil separation for the
> > thickness of the first transparency, the edges were
> > not very clean.
> > 
> > I then had a brainstorm, I realized that my UV filters
> > for my flourescent lighting were amber.  I decided to
> > try other colors... I quickly discovered that yellow
> > was just as dark (in UV) as black. Disappointed that
> > it was not darker, I began thinking about ways I could
> > change the formulation of the ink to include a
> > coreactive UV blocking chemical. I started searching
> > the net when I discovered that ink fading as a result
> > of UV is a real problem for photography. To my
> > surprise, my printer already contained an ink that
> > was UV blocking.  All I had to do was tell the printer
> > that it was printing on high resolution photopaper. 
> > This automatically switched cartridges to the PC
> > (Photo Cyan) and PM (Photomagenta). Yellow remains the
> > same because yellow only fades to yellow.
> > 
> > In any case, once I did that, I was able to fully
> > expose the Photoresist. In comparing a foil blocked
> > section and a photo ink exposed section there
> > was little difference. Moreover, in testing artwork
> > created by a real photoplotter (costing $200,000). 
> > There was no difference. The only difference was that
> > I settled on "GREEN" as being the color that was best.
> > This selected the darkness of yellow in UV and the
> > chemical UV blocking in Photo Cyan to produce a very
> > dark black in UV and a pretty green in visible... :-)
> > 
> > Perfect exposures!  That along with unbelievable
> > resolution of these printers make for a killer
> > combination for producing your own artwork and
> > consequently your own circuit boards.
> > 
> > The bottom line is this. You DON'T want a printer with
> > a dark black! Forget whether it is pigment based ink
> > or dye based ink. That is all irrelavent, none of them
> > are going to be dark enough.
> > 
> > You want a PHOTO printer with PHOTO ink.  Further ALL
> > photoprinters have high resolution in color!  Even the
> > cheap ones ($100)! Just make sure a photo ink is
> > available either from the manufacturer or for an ink
> > refiller. All photo ink is, is ink with UV blocking
> > added so the photos you print don't fade.
> > 
> > What will the photoplotter companies do???
> > 
> > Armed with this information, there is no reason
> > everyone on this list does not do steves killer mod
> > for the Philips Vesta camera or the many circuits
> > for telescope motorization and tracking.
> > 
> > 
> > Best
> > 
> > Marvin Dickens
> > Alpharetta, Georgia
> > 
> > =====
> > Registered Linux User No. 80253
> > If you use linux, get counted at: 
> > http://www.linuxcounter.org
> > 
> > 
> > 		
> > __________________________________
> > Do you Yahoo!?
> > Yahoo! Mail - 50x more storage than other providers!
> > http://promotions.yahoo.com/new_mail

Printer driver modes make large difference. I found for my Epson 660 the 
quantity of ink output is in following order from most to least.


-------------- MODE 1 -----------------
Matte Heavyweight paper     1440 dpi


-------------- MODE 2 -----------------
Photo Quality Inkjet Paper  1440 dpi
  or
Photo Paper                 1440 dpi
  or
Photo Quality Glossy Film   1440 dpi


-------------- MODE 3 -----------------
Photo Quality Inkjet Paper  720 dpi
  or
Photo Paper                 720 dpi
  or
Photo Quality Glossy Film   720 dpi


-------------- MODE 4 -----------------
Inkjet Transparency         360 dpi





All modes give more then enough UV blocking ability. The first mode 
produces too much ink and sometimes causes ink bleeding and even 
puddling on some transparencies. I use mode 3 without problems. Using 
Genuine Epson Transparency, there is never pin holes. Banding or stripes 
are caused by blocked jets and must be fixed.




elsokwak wrote:

> 
> Hi, I have excellent results with a HP DJ960C printing in black
> directly from the Boardmaker PCB design program.
> The printhead MUST be in excellent condition as stripes are a hell of
> a problem.
> ELSO
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Dirk F Ganzinga" <dfg1955@y...>
> wrote:
> 
>>Quite true!! I could not get the transparants well: grey-ish, 
>>striping, etc. I found and read this post and it's now ok. Simply
> 
> set 
> 
>>my Epson Stylus 740 to "Glossy Photopaper" and "Color", printed on
> 
> a 
> 
>>deskjet transparant. It takes a while but it's perfect, much more 
>>black than a laserprinter. Great advise, thanks!
>>Regards,
>>Dirk
>>
>>--- In Homebrew_PCBs@yahoogroups.com, mpdickens <md30022@y...>
> 
> wrote:
> 
>>>A member of another mailing list I am a member of
>>>found the following in a archive. Further, he tested
>>>and it worked as advertised:
>>>
>>>I have been dealing with a development effort for a
>>>circuit that my company is developing. In order to get
>>>fast turnaround of boards for testing, I needed a way
>>>to make high quality circuit boards (multilayer) in
>>>under 8 hours. Cost from commercial board houses for
>>>24 hour turnaround was in the range of $2000-$3000 per
>>>design.  In my case, I had to also develope plating
>>>systems and through-hole activation, fast etching, and
>>>a hot 20 ton press which I built by converting a shop
>>>press from harbor freight and adding a temperature
>>>controller and heating elements.  etc.
>>>
>>>For ATM purposes, 2 sided boards can be made for a
>>>minimal expense.
>>>
>>>Because many on this list make their own circuit
>>>boards on occassion (for stepper circuits and camera
>>>circuits), I thought I would share my experience
>>>with the group.
>>>
>>>I am currently producing 4, 6 and 8 layer circuit
>>>boards using equipment now in my basement. Granted my
>>>basement looks like a chamber of horrors, but I
>>>suspect this is true for many on this list. Eight mil
>>>traces and lands are now easily doable and I am
>>>holding +/- 2 mil registration.
>>>
>>>The greatest roadblock to producing good circuit
>>>boards was getting good artwork on a transparency.  In
>>>that regard, I have made several discoveries which are
>>>not immediately intuitive.
>>>
>>>First, getting really good artwork for the spec above
>>>is not possible with a laser printer. Phase error
>>>creeps in and even for printers claiming 1200
>>>DPI the accuracy just isn't there.  I tested this with
>>>several models of HP printers including the 2000
>>>series and the 4000 series.
>>>
>>>In addition, the toner is just not dark enough.  You
>>>end up having to underexpose the photoresist in order
>>>to get good removal and then you have a problem with
>>>undercured photoresist that will not tent over holes
>>>and whose sides are weak. Further the developing
>>>process just trashes the underexposed resist.
>>>
>>>I finally decided to try an inkjet printer.  After
>>>some research looking for a printer that supported
>>>high resolution in black, I purchased a Canon.
>>>Initially, I purchased the S300 but it turned out that
>>>clever marketing made is sound like it supported high
>>>res black.  In reality, the black was only 600 DPI
>>>like every other printer...  Not enough resolution.  I
>>>then tried the S800, which did support 2400 x 1200 DPI
>>>in color and in Black - the only printer that
>>>supported high resolution black printing. Experiments
>>>with
>>>this printer unfortunately revealed the problem that
>>>most people have with bubble jets.  The black is
>>>simply not dark enough in UV.  This despite the fact
>>>that it was a pigment based ink.
>>>
>>>I did have moderate success stacking tranparenies. 
>>>This allowed me to increase the exposure time, but
>>>because only the first transparency was ink down (the
>>>second had to have a full 5 mil separation for the
>>>thickness of the first transparency, the edges were
>>>not very clean.
>>>
>>>I then had a brainstorm, I realized that my UV filters
>>>for my flourescent lighting were amber.  I decided to
>>>try other colors... I quickly discovered that yellow
>>>was just as dark (in UV) as black. Disappointed that
>>>it was not darker, I began thinking about ways I could
>>>change the formulation of the ink to include a
>>>coreactive UV blocking chemical. I started searching
>>>the net when I discovered that ink fading as a result
>>>of UV is a real problem for photography. To my
>>>surprise, my printer already contained an ink that
>>>was UV blocking.  All I had to do was tell the printer
>>>that it was printing on high resolution photopaper. 
>>>This automatically switched cartridges to the PC
>>>(Photo Cyan) and PM (Photomagenta). Yellow remains the
>>>same because yellow only fades to yellow.
>>>
>>>In any case, once I did that, I was able to fully
>>>expose the Photoresist. In comparing a foil blocked
>>>section and a photo ink exposed section there
>>>was little difference. Moreover, in testing artwork
>>>created by a real photoplotter (costing $200,000). 
>>>There was no difference. The only difference was that
>>>I settled on "GREEN" as being the color that was best.
>>>This selected the darkness of yellow in UV and the
>>>chemical UV blocking in Photo Cyan to produce a very
>>>dark black in UV and a pretty green in visible... :-)
>>>
>>>Perfect exposures!  That along with unbelievable
>>>resolution of these printers make for a killer
>>>combination for producing your own artwork and
>>>consequently your own circuit boards.
>>>
>>>The bottom line is this. You DON'T want a printer with
>>>a dark black! Forget whether it is pigment based ink
>>>or dye based ink. That is all irrelavent, none of them
>>>are going to be dark enough.
>>>
>>>You want a PHOTO printer with PHOTO ink.  Further ALL
>>>photoprinters have high resolution in color!  Even the
>>>cheap ones ($100)! Just make sure a photo ink is
>>>available either from the manufacturer or for an ink
>>>refiller. All photo ink is, is ink with UV blocking
>>>added so the photos you print don't fade.
>>>
>>>What will the photoplotter companies do???
>>>
>>>Armed with this information, there is no reason
>>>everyone on this list does not do steves killer mod
>>>for the Philips Vesta camera or the many circuits
>>>for telescope motorization and tracking.
>>>
>>>
>>>Best
>>>
>>>Marvin Dickens
>>>Alpharetta, Georgia
>>>
>>>=====
>>>Registered Linux User No. 80253
>>>If you use linux, get counted at: 
>>>http://www.linuxcounter.org
>>>
>>>
>>>		
>>>__________________________________
>>>Do you Yahoo!?
>>>Yahoo! Mail - 50x more storage than other providers!
>>>http://promotions.yahoo.com/new_mail
> 
> 
> 
> 
> 
> 
> 
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs 
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 
>