Homebrew PCBs

Hi all,
	I was just wondering how many people here would like to make their own 
plated through hole double sided boards. How far are hobbyists willing 
to go ? The main question is if this extra step is worth the amount of 
chemicals and equipment needed to make plated through. I had the desire 
to make plated boards for a long time but only because I find both the 
chemistry and electronics side interesting. From what I have found with 
experiments, is that the process can be done at home if you are prepared 
to put in the effort. There is a lot setting up with the equipment such 
as plating tanks, etching tanks, making holes conductive, applying dry 
film photoresists and then there is the equipment for analyzing the 
chemistry, not to mention the learning curve. About the only good news 
is that the chemistry is relatively low cost and the toxicity is about 
the same as conventional copper etching solutions (copper is a toxic 
heavy metal). The ultimate aim would be 4 layer boards, but that raises 
a whole new set of hurdles.

reagrds,

Adam

In a message dated 12/9/2002 1:56:21 PM Central Standard Time, 
adam_seychell@... writes:


> I was just wondering how many people here would like to make their own 
> plated through hole double sided boards. How far are hobbyists willing to 
> go ?

Adam:  I do one-off double-sided boards all the time, but without PTH, this 
is relatively easy.  I have a professional PCB-house do jobs requiring ten or 
more PTH "same board", or, where a relatively complex "one-off" job requires 
relatively many PTH holes "under IC's", etc.   Using tiny rivets to "make 
your own" PTH's is cumbersome from several aspects, of course, and I do that 
only when there are relatively few, on ONE board, and "just soldering 
jumpers" won't do.  

So, yes, were it relatively easy to set-up---even if it WOULD require a 
ten-amp DC supply???---I'd be very interested!  

I asked that "local PCB house" if they'd plate-through "blanks" I had already 
drilled, and as this was such a difficult thing for them to COMPREHEND (Why 
would anyone WANT drilled blanks plated-through, and no further 
processing???), they quoted me a price-per that made it more attractive to 
just let them do the "whole thing".  But no "solder-mask" nor silk-screening, 
of course!

I will be VERY interested to follow this question!  GO for it!              

I have another question for this group, while I'm "here":  I "rough-cut" FR-4 
on a bandsaw, using 14-TPI "woodworking" blades.  If fresh, a cut of just 1" 
through that will "total" a blade for woodworking.  I do this actually too 
infrequently to warrant looking at carbide- or "bimetal" blade-stock. 
HOWEVER, it is a royal pain in the gluteæ to hafta change blades!  Does 
anyone have a suggestion for BETTER rough-cutting FR-4 ("glass") stock?  I do 
not mean "shearing", as that requires expensive equipment and space.  I 
"edge-sand" to bring the band-sawn blanks to final size, on a disc-sander.  
For "fancy shapes", I use solid-carbide "rotary files" or mill-bits in a 
vertical mill, with PC-stock fastened to HARDWOOD scrap with "double-stick 
tape". (for drilling, I use a home-brew CNC X-Y drill.  If anyone must see a 
pic of that, I have that digitized, "on-computer", and can upload, if 
wanted).

Jan Rowland


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

JanRwl@... wrote:
> In a message dated 12/9/2002 1:56:21 PM Central Standard Time, 
> adam_seychell@... writes:
> 
> 
> 
>>I was just wondering how many people here would like to make their own 
>>plated through hole double sided boards. How far are hobbyists willing to 
>>go ?
> 
> 
> Adam:  I do one-off double-sided boards all the time, but without PTH, this 
> is relatively easy.  I have a professional PCB-house do jobs requiring ten or 
> more PTH "same board", or, where a relatively complex "one-off" job requires 
> relatively many PTH holes "under IC's", etc.   Using tiny rivets to "make 
> your own" PTH's is cumbersome from several aspects, of course, and I do that 
> only when there are relatively few, on ONE board, and "just soldering 
> jumpers" won't do.  
> 
> So, yes, were it relatively easy to set-up---even if it WOULD require a 
> ten-amp DC supply???---I'd be very interested!  
> 
> I asked that "local PCB house" if they'd plate-through "blanks" I had already 
> drilled, and as this was such a difficult thing for them to COMPREHEND (Why 
> would anyone WANT drilled blanks plated-through, and no further 
> processing???), they quoted me a price-per that made it more attractive to 
> just let them do the "whole thing".  But no "solder-mask" nor silk-screening, 
> of course!
> 
> I will be VERY interested to follow this question!  GO for it!              
> 
> I have another question for this group, while I'm "here":  I "rough-cut" FR-4 
> on a bandsaw, using 14-TPI "woodworking" blades.  If fresh, a cut of just 1" 
> through that will "total" a blade for woodworking.  I do this actually too 
> infrequently to warrant looking at carbide- or "bimetal" blade-stock. 
> HOWEVER, it is a royal pain in the glute\ufffd to hafta change blades!  Does 
> anyone have a suggestion for BETTER rough-cutting FR-4 ("glass") stock?  I do 
> not mean "shearing", as that requires expensive equipment and space.  I 
> "edge-sand" to bring the band-sawn blanks to final size, on a disc-sander.  
> For "fancy shapes", I use solid-carbide "rotary files" or mill-bits in a 
> vertical mill, with PC-stock fastened to HARDWOOD scrap with "double-stick 
> tape". (for drilling, I use a home-brew CNC X-Y drill.  If anyone must see a 
> pic of that, I have that digitized, "on-computer", and can upload, if 
> wanted).

Try a scroll saw if you can find a carbide cutter. The cutter is much
smaller (and cheaper) than a bandsaw blade and you can do more intricate
shapes. It's difficult to get a nice smooth edge like a guillotine.
I use a small 18" guillotine and it's the ultimate for doing pcb
off-cuts. It's very small, about the area of an A3 paper guillotine.

At 05:56 PM 12/9/02 -0500, JanRwl@... wrote:

>I have another question for this group, while I'm "here":  I "rough-cut" FR-4
>on a bandsaw, using 14-TPI "woodworking" blades.  If fresh, a cut of just 1"
>through that will "total" a blade for woodworking.  I do this actually too
>infrequently to warrant looking at carbide- or "bimetal" blade-stock.
>HOWEVER, it is a royal pain in the gluteæ to hafta change blades!  Does
>anyone have a suggestion for BETTER rough-cutting FR-4 ("glass") stock?

Before we got a shear, we used a radial arm saw with a carbide tipped blade 
(still do for ripping 4' x 3' sheet stock down to a size that the shear is 
happy with).  Before that, it was a strictly manual process using an Olfa 
'P Cutter'.  This is a cutter shaped something like a lino knife, except 
with a smaller blade that is replaceable.  The blade can also be 
re-sharpened many times.

In use, just use a metal straight edge as a guide and pull the knife along 
several times.  The blade material is tough enough to score glass epoxy PCB 
material with no problem.  I recall that I'd take 4 or 5 heavy passes 
before snapping the boards apart.

One advantage is that it generates only a little dust.

dwayne



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

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Adam and the group,

If you want to make plated through boards you should consider asking  
a board fabricator to sell you some of their existing chemistry. The 
cost of this stuff is higher than you would think because of the 
minimum quantities that must be purchased when starting new. These 
chemical baths require almost daily testing and replenishment with 
the main culprit being the catalyst and electroless copper baths. 
Some systems don't require an electroless copper bath and use a super 
activated palladium catalyst which is a little easier to maintain.

After taking on something like this you should just go into the 
business and get as much work as you can to make it worth doing. One 
thing to consider is that 15 years ago there were about 3000 shops in 
the USA and earlier today while I was talking with a drilling machine 
supplier he said there were less than 200 shops left in the USA. Many 
of the big guys from earlier years all went broke.

On one hand there is a glut of used equipment available really cheap 
right now which means you can setup a shop without much cash. For 
example, when I closed my PWB plant I sold my best Excellon drilling 
and routing machine for $6500. This machine was in excellent shape 
and cost $146,000 new. One of your biggest expenses will be just 
MOVING all of this equipment and setting it in place. 

On the other hand the business climate in the PWB industry is soft 
with mucho foreign competition so its a tough call on what to do. It 
is a fascinating technical business but there isn't much money in it 
anymore. Printed circuits are a commodity now days with low selling 
prices.

One thing to consider is trying to find some small plating tanks for 
your electrolytic plating and do the through hole sensitizing using 
pyrex trays on hot plates. This will work on a small scale. A small 
spray etcher with sodium persulfate will handle the etching part. If 
you wanted reflowed solder you could modify a donut fryer to get it 
up to 475 degrees F and you would be all set to reflow the tin/lead 
plating.

The rectifier for acid copper plating should be capable of at least 
30 amps per square foot per side. The solder plating requires 
somewhat less current at around 20 amps per square foot. If you use a 
CAM program to setup your films they will tell you the total square 
inches of copper traces and pads for plating. 

When I closed my plant I kept one photoplotter for making precision 
films,a smaller drilling machine, pin router and silk screening 
equipment. Now I just make boards for the instruments and control 
systems that I make. Everything is single sided except for one RF 
board with only four through holes which I bond with eyelets. There 
are times when I miss the plated through capabilities but I manage 
without it and doing fine.

If anyone wants more information on how the plated through process 
works I would be glad to write up something on it. I did it for 
twenty four years and learned it from the ground up.

Tom










--- In Homebrew_PCBs@yahoogroups.com, adam Seychell 
<adam_seychell@y...> wrote:
> Hi all,
> 	I was just wondering how many people here would like to make 
their own 
> plated through hole double sided boards. How far are hobbyists 
willing 
> to go ? The main question is if this extra step is worth the amount 
of 
> chemicals and equipment needed to make plated through. I had the 
desire 
> to make plated boards for a long time but only because I find both 
the 
> chemistry and electronics side interesting. From what I have found 
with 
> experiments, is that the process can be done at home if you are 
prepared 
> to put in the effort. There is a lot setting up with the equipment 
such 
> as plating tanks, etching tanks, making holes conductive, applying 
dry 
> film photoresists and then there is the equipment for analyzing the 
> chemistry, not to mention the learning curve. About the only good 
news 
> is that the chemistry is relatively low cost and the toxicity is 
about 
> the same as conventional copper etching solutions (copper is a 
toxic 
> heavy metal). The ultimate aim would be 4 layer boards, but that 
raises 

> a whole new set of hurdles.
> 
> reagrds,
> 
> Adam

Jan,
About cutting FR4.... I had the same experience using using cutting
blades even when labeled for metal cutting.
I did find a solution, but requires some work.
I use Junior Hacksaw blades, I have to grind them to fit by scroll saw
length. As the portion of the blade that does the cutting is limited to
about 1/2" on my scroll saw I also grind down the width of the blade,
this helps in steering the FR4 while cutting.
The effort does pay off, one Junior Hacksaw blade will cut several
"feet" of FR4.
Form some time I looked for Junior Hacksaw blades in my local hardware
store, and even a specialist store and could not find them ! I finally
ended up getting family to buy the in the UK and ship them here.... A
few weeks ago I had a plumbing problem and ended up at Home Depot in the
plumbing department only to notice that's where Junior Hacksaw bladed
and saws are sold ! They are not called Junior Hacksaw in this country !
The Stanley Part number (form UK) is 3-15-905  I seem to remember they
called them mini hacksaw at Home Depot.

If you need me to post a photo of a prepared blade, let me know.

About Through Hole plating:
I discussed this process used by my favorite PCB shop and it does NOT
involve electro plating.
They simply "activate" the holes with a solution (I'm working on finding
the formula) and after that the board is place in another solution
containing copper. The process does not involve electroplating at all.

As soon as I have the formula for both solutions, I'll test and
publish...

Hans W

Adam,
I just posted a message about  solutions, and would like to know what is
in the "super activated palladium catalyst" and "electroless copper
bath" ?
Also what is the "daily process" for testing and maintaining them ?
How long can these solution be stored ?
How does one get rid of used solutions?
Hans W


"twb8899 " wrote:

>  Adam and the group,
>
> If you want to make plated through boards you should consider asking
> a board fabricator to sell you some of their existing chemistry. The
> cost of this stuff is higher than you would think because of the
> minimum quantities that must be purchased when starting new. These
> chemical baths require almost daily testing and replenishment with
> the main culprit being the catalyst and electroless copper baths.
> Some systems don't require an electroless copper bath and use a super
> activated palladium catalyst which is a little easier to maintain.


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

Hello Hans,
I didn't give any details on the process I was using only because I 
haven't got it working good as I like and it would take me all day to 
write up :). Basically I'm using a variation of the proprietary 
BLACKHOLE process by Macdermid. Search the web for "blackhole pcb". 
Macdermid hold the exact chemistry a secret but I've managed to get some 
good results by investigating all the patents on the subject. A long 
time ago I looked into electroless copper and found it was an expensive 
and difficult process to run, so I didn't bother with it. Electroless 
copper is widely used by platers and has been around since 40's (I 
think) so you won't have trouble finding info in a good library.

Tom is absolutely right in that most chemicals are only available in 
bulk. A bulk quantity for hobbyist is 25 kg, but that's about a minimum 
sale for any chemical from any chemical supplier. I was lucky enough to 
get some of my chemicals in small quantity. Others such as 98% sulfuric 
acid, and 25% aqua ammonia I could get in 25 liter, fortunately these 
are cheap.

Waste disposal is discussed in many plating books. The carbon black 
solutions are non-toxic and I regularly dump them on the garden with 
zero effect to the plants (just makes the soil a bit blacker :).

If you want to do electroless copper then your best bet is to contact 
your local plating supplier and ask them to supply you with the 
chemicals. They know exactly how their chemicals behave and how to use 
them so all the hard work is done for you. You will find it difficult 
obtaining all the individual ingredients and trying to make it work for 
your self.

The bottom line is that if you don't like handing chemicals and not 
interested in the chemistry then I think it would be a waste of time for 
anyone trying to make through hole boards as part of their hobby.
The electroless is only a fraction of the whole process. It took me a 
about year before I could successfully plate copper and tin on PCBs. 
Each step in the process is completely different to learn and 
understand. Unfortunately PCB making involves so many of these steps.

If you are still interested in making holes platable then I'd be happy 
to sometime write about the carbon black process. But it won't be of 
much use unless you can also do dry film photoresist lamination, hot 
soak cleaning, acid copper plating, acid tin plating, persulfate micro 
etching and alkaline ammonia etching and photoresists stripping.


Hans Wedemeyer wrote:

> Adam,
> I just posted a message about  solutions, and would like to know what is
> in the "super activated palladium catalyst" and "electroless copper
> bath" ?
> Also what is the "daily process" for testing and maintaining them ?
> How long can these solution be stored ?
> How does one get rid of used solutions?
> Hans W
> 
> 
> "twb8899 " wrote:
> 
> 
>> Adam and the group,
>>
>>If you want to make plated through boards you should consider asking
>>a board fabricator to sell you some of their existing chemistry. The
>>cost of this stuff is higher than you would think because of the
>>minimum quantities that must be purchased when starting new. These
>>chemical baths require almost daily testing and replenishment with
>>the main culprit being the catalyst and electroless copper baths.
>>Some systems don't require an electroless copper bath and use a super
>>activated palladium catalyst which is a little easier to maintain.
> 
> 
> 
> [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
> 
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
> 
>  
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 
> 
>

In a message dated 12/9/2002 7:01:15 PM Central Standard Time, 
rjshaw@... writes:


> It's difficult to get a nice smooth edge like a guillotine.  I use a small 
> 18" guillotine and it's the ultimate for doing pcb
> off-cuts. It's very small, about the area of an A3 paper guillotine.

I take it this "guilotine" is the European word for "paper cutter" such as is 
used in offices and schools?  What kind of KNIFE - edges would you use?  
Seems the HSS (if that!) blades those COME with wouldn't stay sharp past half 
a dozen cuts!

(Once I had 'em rough-cut (1 mm oversize), I'd disk-sand 'em to exact shape.)

Yes, papercutters are readily available and cheap.  I'd call that "shearing 
to size".  But one would have to use some kind of hold-fast technique a bit 
more reliable than three or four left fingers on the piece laying on the 
board!  Say, double-stick tape AND those fat left-hand fingers?  

I have a paper-cutter, but that's here in the office, FOR office-work.  I 
will have to go BUY a cheap one and try that!

Thanks!   Jan Rowland


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

In a message dated 12/9/2002 7:10:06 PM Central Standard Time, 
twb8899@... writes:


> If anyone wants more information on how the plated through process 
> works I would be glad to write up something on it.

Tom!  Yes, I, at least, would LOVE to read that!          Jan Rowland


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

JanRwl@... wrote:
> In a message dated 12/9/2002 7:01:15 PM Central Standard Time, 
> rjshaw@... writes:
> 
>>It's difficult to get a nice smooth edge like a guillotine.  I use a small 
>>18" guillotine and it's the ultimate for doing pcb
>>off-cuts. It's very small, about the area of an A3 paper guillotine.
> 
> 
> I take it this "guilotine" is the European word for "paper cutter" such as is 
> used in offices and schools?  What kind of KNIFE - edges would you use?  
> Seems the HSS (if that!) blades those COME with wouldn't stay sharp past half 
> a dozen cuts!

It's a *real* guillotine with upper and lower shearing edges made from
hard 10mm thick ground steel. It can cut 1/16" soft materials like brass
and copper and 1/32" harder things like steel. It is all metal construction.
IIRC, there's small guillotines like this in Farnell or Radio Spares
catalogues. Mine was hand made by an engineer with nothing else to do;)

Adam,
Thanks for the description and insight. I have been talking to my
favorite PCB shop and they may sell me a small quantity of the activator
they use.
I expect they can tell me how long the shelf life is for such chemicals.

Best Regards
Hans W

adam Seychell wrote:

>  Hello Hans,
> I didn't give any details on the process I was using only because I
> haven't got it working good as I like and it would take me all day to
> write up :). Basically I'm using a variation of the proprietary
> BLACKHOLE process by Macdermid. Search the web for "blackhole pcb".
> Macdermid hold the exact chemistry a secret but I've managed to get
> some
> good results by investigating all the patents on the subject. A long
> time ago I looked into electroless copper and found it was an
> expensive
> and difficult process to run, so I didn't bother with it. Electroless
> copper is widely used by platers and has been around since 40's (I
> think) so you won't have trouble finding info in a good library.
>
> Tom is absolutely right in that most chemicals are only available in
> bulk. A bulk quantity for hobbyist is 25 kg, but that's about a
> minimum
> sale for any chemical from any chemical supplier. I was lucky enough
> to
> get some of my chemicals in small quantity. Others such as 98%
> sulfuric
> acid, and 25% aqua ammonia I could get in 25 liter, fortunately these
> are cheap.
>
> Waste disposal is discussed in many plating books. The carbon black
> solutions are non-toxic and I regularly dump them on the garden with
> zero effect to the plants (just makes the soil a bit blacker :).
>
> If you want to do electroless copper then your best bet is to contact
> your local plating supplier and ask them to supply you with the
> chemicals. They know exactly how their chemicals behave and how to use
>
> them so all the hard work is done for you. You will find it difficult
> obtaining all the individual ingredients and trying to make it work
> for
> your self.
>
> The bottom line is that if you don't like handing chemicals and not
> interested in the chemistry then I think it would be a waste of time
> for
> anyone trying to make through hole boards as part of their hobby.
> The electroless is only a fraction of the whole process. It took me a
> about year before I could successfully plate copper and tin on PCBs.
> Each step in the process is completely different to learn and
> understand. Unfortunately PCB making involves so many of these steps.
>
> If you are still interested in making holes platable then I'd be happy
>
> to sometime write about the carbon black process. But it won't be of
> much use unless you can also do dry film photoresist lamination, hot
> soak cleaning, acid copper plating, acid tin plating, persulfate micro
>
> etching and alkaline ammonia etching and photoresists stripping.
>
>
> Hans Wedemeyer wrote:
> > Adam,
> > I just posted a message about  solutions, and would like to know
> what is
> > in the "super activated palladium catalyst" and "electroless copper
> > bath" ?
> > Also what is the "daily process" for testing and maintaining them ?
> > How long can these solution be stored ?
> > How does one get rid of used solutions?
> > Hans W
> >
> >
> > "twb8899 " wrote:
> >
> >
> >> Adam and the group,
> >>
> >>If you want to make plated through boards you should consider asking
>
> >>a board fabricator to sell you some of their existing chemistry. The
>
> >>cost of this stuff is higher than you would think because of the
> >>minimum quantities that must be purchased when starting new. These
> >>chemical baths require almost daily testing and replenishment with
> >>the main culprit being the catalyst and electroless copper baths.
> >>Some systems don't require an electroless copper bath and use a
> super
> >>activated palladium catalyst which is a little easier to maintain.
> >
> >
> >
> > [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
> >
> > To unsubscribe from this group, send an email to:
> > Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
>
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


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

Hi Jan,

    For the last 30 years I have used a regular paper cutter to cut the glass board. I would recommend one with at least a 18" handle i.e.. a 12"x12" cutter. Contrary to what you would expect, it doesn't seem to bother the blade. The board will want to be pushed out a small amount by the blade as it comes down. Most of the time I just press down very firmly on the board and hold it tight to the guide and press the handle uniformly and quickly down and the board just jumps apart. It works fine. If I wanted to be sure that it cut perfectly square I would clamp a thin piece of wood or metal to the surface of the cutter and use it to hold the PVC back against the guide so it couldn't be pushed out. Of course, you would still want to hold it down by hand as it was cut.

     You can find used paper cutters on eBay - search "paper cutter" - for $20 or so - not much more than one good bandsaw blade.

    Hope that this is of help. 

Jack Greene

----- Original Message ----- 
  From: JanRwl@... 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Monday, December 09, 2002 3:56 PM
  Subject: Re: [Homebrew_PCBs] plated through holes


  In a message dated 12/9/2002 1:56:21 PM Central Standard Time, 
  adam_seychell@... writes:


  > I was just wondering how many people here would like to make their own 
  > plated through hole double sided boards. How far are hobbyists willing to 
  > go ?

  Adam:  I do one-off double-sided boards all the time, but without PTH, this 
  is relatively easy.  I have a professional PCB-house do jobs requiring ten or 
  more PTH "same board", or, where a relatively complex "one-off" job requires 
  relatively many PTH holes "under IC's", etc.   Using tiny rivets to "make 
  your own" PTH's is cumbersome from several aspects, of course, and I do that 
  only when there are relatively few, on ONE board, and "just soldering 
  jumpers" won't do.  

  So, yes, were it relatively easy to set-up---even if it WOULD require a 
  ten-amp DC supply???---I'd be very interested!  

  I asked that "local PCB house" if they'd plate-through "blanks" I had already 
  drilled, and as this was such a difficult thing for them to COMPREHEND (Why 
  would anyone WANT drilled blanks plated-through, and no further 
  processing???), they quoted me a price-per that made it more attractive to 
  just let them do the "whole thing".  But no "solder-mask" nor silk-screening, 
  of course!

  I will be VERY interested to follow this question!  GO for it!              

  I have another question for this group, while I'm "here":  I "rough-cut" FR-4 
  on a bandsaw, using 14-TPI "woodworking" blades.  If fresh, a cut of just 1" 
  through that will "total" a blade for woodworking.  I do this actually too 
  infrequently to warrant looking at carbide- or "bimetal" blade-stock. 
  HOWEVER, it is a royal pain in the gluteæ to hafta change blades!  Does 
  anyone have a suggestion for BETTER rough-cutting FR-4 ("glass") stock?  I do 
  not mean "shearing", as that requires expensive equipment and space.  I 
  "edge-sand" to bring the band-sawn blanks to final size, on a disc-sander.  
  For "fancy shapes", I use solid-carbide "rotary files" or mill-bits in a 
  vertical mill, with PC-stock fastened to HARDWOOD scrap with "double-stick 
  tape". (for drilling, I use a home-brew CNC X-Y drill.  If anyone must see a 
  pic of that, I have that digitized, "on-computer", and can upload, if 
  wanted).

  Jan Rowland


  [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

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

Hey guys, The plated through holes is interesting, yet it sounds 
costly and burdomsome, as well as risky disposal issues. I have never 
had the need to made a quantity amout of boards, just 2 or 3 of the 
same footprint. I have never used plated through holes, but I have 
used little tiny metal insert sleeves I saw in a catalog. I was 
already placing an order anyway so nix the shipping fees for just the 
sleeves. I used these on a realatively small board ( probably less 
than 100 holes), and everything worked out great. 

I am not a seasoned vet at this. I just like to tinker. This worked 
for me, but I am wondering - did I just get lucky? Did I do something 
totally taboo? Or is plated through holes something totally different?

...just a newbie trying to fit in,
                                  -OpryStar

Thanks for the "paper cutter reply"   I will gawk at Office Despot (nearby).


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

Opry:

There is no POINT in fussing with plated-through-holes for just a few holes 
that "must" be "plated through" or a few boards with a few such holes!  The 
"tiny rivets" are the way to do those, where a "PTH" "MUST" go under an IC, 
etc.  On those holes for resistors, etc., one can simply solder on the top 
AND bottom, and not need even the rivets.  

The only thing "magic" about PTH is, done professionally with 
"solder-plating", and all, they "wick" the solder nicely, so solder-joints 
are neater and use much less solder, and are electrically much, much more 
secure.  But that's actually kinda "academic" if everything else is done 
neatly!

Jan Rowland


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

JanRwl@... wrote:
> Opry:
> 
> There is no POINT in fussing with plated-through-holes for just a few holes 
> that "must" be "plated through" or a few boards with a few such holes!  The 
> "tiny rivets" are the way to do those, where a "PTH" "MUST" go under an IC, 
> etc.  On those holes for resistors, etc., one can simply solder on the top 
> AND bottom, and not need even the rivets.  
> 
> The only thing "magic" about PTH is, done professionally with 
> "solder-plating", and all, they "wick" the solder nicely, so solder-joints 
> are neater and use much less solder, and are electrically much, much more 
> secure.  But that's actually kinda "academic" if everything else is done 
> neatly!

The main reason i'm interested in PTH is for joining to inner layers
of multilayer boards when i eventually get something working.

Hi Jan,

some choices are diamond saws and your big clunky chop saw.

my chop saw has a sever wobble and will not do any fine work so it is 
OK for roughing big sheets.

Harbor Freight sells a diamond tile saw for less than $100.00. tiny 
blade, but you can get a great cut, very accuratly. and you will not 
wear out that blade.

another choice it to clamp it on your mill and use a Vee point cutter 
to mill a slot.  both sides then break at the line and topuch up with 
a file.

Dave


--- In Homebrew_PCBs@yahoogroups.com, Dwayne Reid <dwayner@p...> 
wrote:
> At 05:56 PM 12/9/02 -0500, JanRwl@A... wrote:
> 
> >I have another question for this group, while I'm "here":  
I "rough-cut" FR-4
> >on a bandsaw, using 14-TPI "woodworking" blades.  If fresh, a cut 
of just 1"
> >through that will "total" a blade for woodworking.  I do this 
actually too
> >infrequently to warrant looking at carbide- or "bimetal" blade-
stock.
> >HOWEVER, it is a royal pain in the gluteæ to hafta change blades!  
Does
> >anyone have a suggestion for BETTER rough-cutting FR-4 ("glass") 
stock?
> 
> Before we got a shear, we used a radial arm saw with a carbide 
tipped blade 
> (still do for ripping 4' x 3' sheet stock down to a size that the 
shear is 
> happy with).  Before that, it was a strictly manual process using 
an Olfa 
> 'P Cutter'.  This is a cutter shaped something like a lino knife, 
except 
> with a smaller blade that is replaceable.  The blade can also be 
> re-sharpened many times.
> 
> In use, just use a metal straight edge as a guide and pull the 
knife along 
> several times.  The blade material is tough enough to score glass 
epoxy PCB 
> material with no problem.  I recall that I'd take 4 or 5 heavy 
passes 

> before snapping the boards apart.
> 
> One advantage is that it generates only a little dust.
> 
> dwayne
> 
> 
> 
> --
> Dwayne Reid   <dwayner@p...>
> Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
> (780) 489-3199 voice          (780) 487-6397 fax
> 
> Celebrating 18 years of Engineering Innovation (1984 - 2002)
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