Homebrew PCBs

Hi all,

Been a silent member for a while. Just picked up an old HP 6L laser
printer to start my project. Glad I read up on the laser printer
process first in this group, as I made the guy put in a toner
cartridge that actually printed out dark black not gray as the first
one did. Score one for the group!

The project is an electric truck. It has 104 12v batterys. It needs a
bit of overvoltage regulation to prevent it from toasting 104 $60
batterys. So that means the potential of making 104 pcb's plus spares.
It's fairly simple with all the parts on just one side, and smt at that.

It looks like since I originally joined, that using a heat press for
doing badges and such has become quite helpful. Not sure what you call
the machine. I will look into that as well. I planned on using just a
standard teflon coated clothes iron to press the toner to the pcb. But
after printing out the pcb's in a 4 pcb x 5 pcb pattern, it occured to
me that the 12 mil traces are too narrow for this type of pcb
manufacturing. The pcb is about 2.3 x 2.8 or so. So far 20 of them fit
on an 8 1/2 x 11 sheet. Seems that the rolling press might pay for
itself over 104+ pcb's. More research. Any brands that stand out? At
this point I'll take any tips you guys have.

Thanks,

Mike

Mike Phillips wrote:

> So that means the potential of making 104 pcb's plus spares.
> It's fairly simple with all the parts on just one side, and smt at that.

Wouldn't you consider farming out the production of 100+
boards?  I'd be hard pressed to do better on price or
quality compared with a commercial board house for this
quantity.  Aside from fabing the blank board, assembly
also may get a bit old after the first dozen or so boards.

-- 
uhmgawa@...        www.gnu.org

On Wed, 13 Jul 2005 21:17:01 +0200, Mike Phillips <mikep_95133@...>  
wrote:

> Hi all,
> Been a silent member for a while. Just picked up an old HP 6L laser
> printer to start my project. Glad I read up on the laser printer
> process first in this group, as I made the guy put in a toner
> cartridge that actually printed out dark black not gray as the first
> one did. Score one for the group!
> The project is an electric truck. It has 104 12v batterys. It needs a
> bit of overvoltage regulation to prevent it from toasting 104 $60
> batterys. So that means the potential of making 104 pcb's plus spares.
> It's fairly simple with all the parts on just one side, and smt at that.
> It looks like since I originally joined, that using a heat press for
> doing badges and such has become quite helpful. Not sure what you call
> the machine. I will look into that as well. I planned on using just a
> standard teflon coated clothes iron to press the toner to the pcb. But
> after printing out the pcb's in a 4 pcb x 5 pcb pattern, it occured to
> me that the 12 mil traces are too narrow for this type of pcb
> manufacturing. The pcb is about 2.3 x 2.8 or so. So far 20 of them fit
> on an 8 1/2 x 11 sheet. Seems that the rolling press might pay for
> itself over 104+ pcb's. More research. Any brands that stand out? At
> this point I'll take any tips you guys have.
> Thanks,
> Mike


that rolling press is called a laminator, and it is much better than using  
an iron (more consistent results).
There are brands that are known to work, but i use a old fuser from a  
copier so i dunno.
Others will surely comment.


For such a large number of PCBs even i would consider a commercial  
service, as they are incredibly cheap now, esp. if yoou need more than 20  
PCBs or so. look in the links section, and i know futurlec is pretty cheap  
too, though it takes a while.

ST

Ah yes, a laminator. It does sound appealing. 

Part of the problem is seeing if the circuit does it's job over time.
If I have to change the layout, then it would be cheaper to do it
myself, I think. I will look up some vendors just to have a more
complete idea.

Maybe using the toner method would be better for proof of concept for
maybe 1 or 2 dozen boards, then later decide what route to take. I
don't mind soldering the boards myself. 

Any thoughts on routing a couple dozen or so boards? Anyone tried that
many with a cnc?

Mike



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Wed, 13 Jul 2005 21:17:01 +0200, Mike Phillips <mikep_95133@y...>  
> wrote:
> 
> > Hi all,
> > Been a silent member for a while. Just picked up an old HP 6L laser
> > printer to start my project. Glad I read up on the laser printer
> > process first in this group, as I made the guy put in a toner
> > cartridge that actually printed out dark black not gray as the first
> > one did. Score one for the group!
> > The project is an electric truck. It has 104 12v batterys. It needs a
> > bit of overvoltage regulation to prevent it from toasting 104 $60
> > batterys. So that means the potential of making 104 pcb's plus spares.
> > It's fairly simple with all the parts on just one side, and smt at
that.
> > It looks like since I originally joined, that using a heat press for
> > doing badges and such has become quite helpful. Not sure what you call
> > the machine. I will look into that as well. I planned on using just a
> > standard teflon coated clothes iron to press the toner to the pcb. But
> > after printing out the pcb's in a 4 pcb x 5 pcb pattern, it occured to
> > me that the 12 mil traces are too narrow for this type of pcb
> > manufacturing. The pcb is about 2.3 x 2.8 or so. So far 20 of them fit
> > on an 8 1/2 x 11 sheet. Seems that the rolling press might pay for
> > itself over 104+ pcb's. More research. Any brands that stand out? At
> > this point I'll take any tips you guys have.
> > Thanks,
> > Mike
> 
> 
> that rolling press is called a laminator, and it is much better than
using  
> an iron (more consistent results).
> There are brands that are known to work, but i use a old fuser from a  
> copier so i dunno.
> Others will surely comment.
> 
> 
> For such a large number of PCBs even i would consider a commercial  
> service, as they are incredibly cheap now, esp. if yoou need more
than 20  
> PCBs or so. look in the links section, and i know futurlec is pretty
cheap  

> too, though it takes a while.
> 
> ST

After looking at Futurlec, maybe I should have not purchased the laser
printer :) They were very cheap.

I really like doing stuff my self. Maybe a couple cnc protos is a
better was to start.

Mike



--- In Homebrew_PCBs@yahoogroups.com, uhmgawa <uhmgawa@m...> wrote:
> Mike Phillips wrote:
> 
> > So that means the potential of making 104 pcb's plus spares.
> > It's fairly simple with all the parts on just one side, and smt at
that.

> 
> Wouldn't you consider farming out the production of 100+
> boards?  I'd be hard pressed to do better on price or
> quality compared with a commercial board house for this
> quantity.  Aside from fabing the blank board, assembly
> also may get a bit old after the first dozen or so boards.
> 
> -- 
> uhmgawa@m...        www.gnu.org

well, a laser printer isn't totally a waste...

I would proto with toner transfer and then when you've got it right,
use a board house to make your 100+ boards (make a bunch of spares). 
Also, you may find interest from others and be able to a larger batch
to share the costs and thus reduce the per board cost.  Also, don't
forget drilling time/tedium.  even with a cnc set up it will take time
to drill 100+ boards.

If you use a board house that will allow you to panelize you may get
significant savings.  A number of them will and some wont.

I did a project where I did 50 boards via TT.  It was actually 8
panels of 7 individual boards so it wasn't that hard.  and it was
mostly surface mount so there wasn't a lot of drilling.

Phil

--- In Homebrew_PCBs@yahoogroups.com, "Mike Phillips"
<mikep_95133@y...> wrote:

> After looking at Futurlec, maybe I should have not purchased the laser
> printer :) They were very cheap.
> 
> I really like doing stuff my self. Maybe a couple cnc protos is a
> better was to start.
> 
> Mike
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, uhmgawa <uhmgawa@m...> wrote:
> > Mike Phillips wrote:
> > 
> > > So that means the potential of making 104 pcb's plus spares.
> > > It's fairly simple with all the parts on just one side, and smt at
> that.
> > 
> > Wouldn't you consider farming out the production of 100+
> > boards?  I'd be hard pressed to do better on price or
> > quality compared with a commercial board house for this
> > quantity.  Aside from fabing the blank board, assembly
> > also may get a bit old after the first dozen or so boards.
> > 
> > -- 
> > uhmgawa@m...        www.gnu.org

Sounds like a plan. I'll thicken up the traces and then give the toner
transfer a try. Are 12 mil traces that difficult?

Mike



--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:

> well, a laser printer isn't totally a waste...
> 
> I would proto with toner transfer and then when you've got it right,
> use a board house to make your 100+ boards (make a bunch of spares). 
> Also, you may find interest from others and be able to a larger batch
> to share the costs and thus reduce the per board cost.  Also, don't
> forget drilling time/tedium.  even with a cnc set up it will take time
> to drill 100+ boards.
> 
> If you use a board house that will allow you to panelize you may get
> significant savings.  A number of them will and some wont.
> 
> I did a project where I did 50 boards via TT.  It was actually 8
> panels of 7 individual boards so it wasn't that hard.  and it was
> mostly surface mount so there wasn't a lot of drilling.
> 
> Phil
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Mike Phillips"
> <mikep_95133@y...> wrote:
> > After looking at Futurlec, maybe I should have not purchased the laser
> > printer :) They were very cheap.
> > 
> > I really like doing stuff my self. Maybe a couple cnc protos is a
> > better was to start.
> > 
> > Mike
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, uhmgawa <uhmgawa@m...> wrote:
> > > Mike Phillips wrote:
> > > 
> > > > So that means the potential of making 104 pcb's plus spares.
> > > > It's fairly simple with all the parts on just one side, and smt at
> > that.
> > > 
> > > Wouldn't you consider farming out the production of 100+
> > > boards?  I'd be hard pressed to do better on price or
> > > quality compared with a commercial board house for this
> > > quantity.  Aside from fabing the blank board, assembly
> > > also may get a bit old after the first dozen or so boards.
> > > 
> > > -- 
> > > uhmgawa@m...        www.gnu.org

I typically use 12 mil.  I can make 10 mil traces as well but 12 mil
is a little more forgiving.

--- In Homebrew_PCBs@yahoogroups.com, "Mike Phillips"
<mikep_95133@y...> wrote:
> Sounds like a plan. I'll thicken up the traces and then give the toner
> transfer a try. Are 12 mil traces that difficult?
> 
> Mike
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
> > well, a laser printer isn't totally a waste...
> > 
> > I would proto with toner transfer and then when you've got it right,
> > use a board house to make your 100+ boards (make a bunch of spares). 
> > Also, you may find interest from others and be able to a larger batch
> > to share the costs and thus reduce the per board cost.  Also, don't
> > forget drilling time/tedium.  even with a cnc set up it will take time
> > to drill 100+ boards.
> > 
> > If you use a board house that will allow you to panelize you may get
> > significant savings.  A number of them will and some wont.
> > 
> > I did a project where I did 50 boards via TT.  It was actually 8
> > panels of 7 individual boards so it wasn't that hard.  and it was
> > mostly surface mount so there wasn't a lot of drilling.
> > 
> > Phil
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Mike Phillips"
> > <mikep_95133@y...> wrote:
> > > After looking at Futurlec, maybe I should have not purchased the
laser
> > > printer :) They were very cheap.
> > > 
> > > I really like doing stuff my self. Maybe a couple cnc protos is a
> > > better was to start.
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, uhmgawa <uhmgawa@m...> wrote:
> > > > Mike Phillips wrote:
> > > > 
> > > > > So that means the potential of making 104 pcb's plus spares.
> > > > > It's fairly simple with all the parts on just one side, and
smt at

> > > that.
> > > > 
> > > > Wouldn't you consider farming out the production of 100+
> > > > boards?  I'd be hard pressed to do better on price or
> > > > quality compared with a commercial board house for this
> > > > quantity.  Aside from fabing the blank board, assembly
> > > > also may get a bit old after the first dozen or so boards.
> > > > 
> > > > -- 
> > > > uhmgawa@m...        www.gnu.org

Hi Phil,

Don't be hung up on very thin traces. Having wide
traces means less copper to etch away. Only use the
thinnest to get the circuit laid out.

You my want to post a photo of the pcb or else the
layout for comments.

Myc

--- Phil <phil1960us@...> wrote:

> I typically use 12 mil.  I can make 10 mil traces as
> well but 12 mil
> is a little more forgiving.
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Mike
> Phillips"
> <mikep_95133@y...> wrote:
> > Sounds like a plan. I'll thicken up the traces and
> then give the toner
> > transfer a try. Are 12 mil traces that difficult?
> > 
> > Mike
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Phil"
> <phil1960us@y...> wrote:
> > > well, a laser printer isn't totally a waste...
> > > 
> > > I would proto with toner transfer and then when
> you've got it right,
> > > use a board house to make your 100+ boards (make
> a bunch of spares). 
> > > Also, you may find interest from others and be
> able to a larger batch
> > > to share the costs and thus reduce the per board
> cost.  Also, don't
> > > forget drilling time/tedium.  even with a cnc
> set up it will take time
> > > to drill 100+ boards.
> > > 
> > > If you use a board house that will allow you to
> panelize you may get
> > > significant savings.  A number of them will and
> some wont.
> > > 
> > > I did a project where I did 50 boards via TT. 
> It was actually 8
> > > panels of 7 individual boards so it wasn't that
> hard.  and it was
> > > mostly surface mount so there wasn't a lot of
> drilling.
> > > 
> > > Phil
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "Mike
> Phillips"
> > > <mikep_95133@y...> wrote:
> > > > After looking at Futurlec, maybe I should have
> not purchased the
> laser
> > > > printer :) They were very cheap.
> > > > 
> > > > I really like doing stuff my self. Maybe a
> couple cnc protos is a
> > > > better was to start.
> > > > 
> > > > Mike
> > > > 
> > > > 
> > > > 
> > > > --- In Homebrew_PCBs@yahoogroups.com, uhmgawa
> <uhmgawa@m...> wrote:
> > > > > Mike Phillips wrote:
> > > > > 
> > > > > > So that means the potential of making 104
> pcb's plus spares.
> > > > > > It's fairly simple with all the parts on
> just one side, and
> smt at
> > > > that.
> > > > > 
> > > > > Wouldn't you consider farming out the
> production of 100+
> > > > > boards?  I'd be hard pressed to do better on
> price or
> > > > > quality compared with a commercial board
> house for this
> > > > > quantity.  Aside from fabing the blank
> board, assembly
> > > > > also may get a bit old after the first dozen
> or so boards.
> > > > > 
> > > > > -- 
> > > > > uhmgawa@m...        www.gnu.org
> 
> 
> 



		
____________________________________________________
Start your day with Yahoo! - make it your home page 
http://www.yahoo.com/r/hs

I posted a panel of the pcb for my truck project. It's in the folder
labeled Mikep_95133's.

Glad to know that 12 mil is not so bad.

Mike



--- In Homebrew_PCBs@yahoogroups.com, Mycroft2152 <mycroft2152@y...>
wrote:

> Hi Phil,
> 
> Don't be hung up on very thin traces. Having wide
> traces means less copper to etch away. Only use the
> thinnest to get the circuit laid out.
> 
> You my want to post a photo of the pcb or else the
> layout for comments.
> 
> Myc
> 
> --- Phil <phil1960us@y...> wrote:
> 
> > I typically use 12 mil.  I can make 10 mil traces as
> > well but 12 mil
> > is a little more forgiving.
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Mike
> > Phillips"
> > <mikep_95133@y...> wrote:
> > > Sounds like a plan. I'll thicken up the traces and
> > then give the toner
> > > transfer a try. Are 12 mil traces that difficult?
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "Phil"
> > <phil1960us@y...> wrote:
> > > > well, a laser printer isn't totally a waste...
> > > > 
> > > > I would proto with toner transfer and then when
> > you've got it right,
> > > > use a board house to make your 100+ boards (make
> > a bunch of spares). 
> > > > Also, you may find interest from others and be
> > able to a larger batch
> > > > to share the costs and thus reduce the per board
> > cost.  Also, don't
> > > > forget drilling time/tedium.  even with a cnc
> > set up it will take time
> > > > to drill 100+ boards.
> > > > 
> > > > If you use a board house that will allow you to
> > panelize you may get
> > > > significant savings.  A number of them will and
> > some wont.
> > > > 
> > > > I did a project where I did 50 boards via TT. 
> > It was actually 8
> > > > panels of 7 individual boards so it wasn't that
> > hard.  and it was
> > > > mostly surface mount so there wasn't a lot of
> > drilling.
> > > > 
> > > > Phil
> > > > 
> > > > --- In Homebrew_PCBs@yahoogroups.com, "Mike
> > Phillips"
> > > > <mikep_95133@y...> wrote:
> > > > > After looking at Futurlec, maybe I should have
> > not purchased the
> > laser
> > > > > printer :) They were very cheap.
> > > > > 
> > > > > I really like doing stuff my self. Maybe a
> > couple cnc protos is a
> > > > > better was to start.
> > > > > 
> > > > > Mike
> > > > > 
> > > > > 
> > > > > 
> > > > > --- In Homebrew_PCBs@yahoogroups.com, uhmgawa
> > <uhmgawa@m...> wrote:
> > > > > > Mike Phillips wrote:
> > > > > > 
> > > > > > > So that means the potential of making 104
> > pcb's plus spares.
> > > > > > > It's fairly simple with all the parts on
> > just one side, and
> > smt at
> > > > > that.
> > > > > > 
> > > > > > Wouldn't you consider farming out the
> > production of 100+
> > > > > > boards?  I'd be hard pressed to do better on
> > price or
> > > > > > quality compared with a commercial board
> > house for this
> > > > > > quantity.  Aside from fabing the blank
> > board, assembly
> > > > > > also may get a bit old after the first dozen
> > or so boards.
> > > > > > 
> > > > > > -- 
> > > > > > uhmgawa@m...        www.gnu.org
> > 
> > 
> > 
> 
> 
> 
> 		
> ____________________________________________________
> Start your day with Yahoo! - make it your home page 
> http://www.yahoo.com/r/hs

On Thu, 14 Jul 2005 00:04:16 +0200, Mike Phillips <mikep_95133@...>  
wrote:

>
> Maybe using the toner method would be better for proof of concept for
> maybe 1 or 2 dozen boards, then later decide what route to take. I
> don't mind soldering the boards myself.


That's what i'd do.

ST

On Thu, 14 Jul 2005 02:47:30 +0200, Mike Phillips <mikep_95133@...>  
wrote:

> Sounds like a plan. I'll thicken up the traces and then give the toner
> transfer a try. Are 12 mil traces that difficult?
> Mike


nah you can make 8 mil if it really must be, but wider is certainly more  
mistake-tolerant.

ST

I'm not sure how you got "hung up" out of my comments.  Maybe you got
confused - I'm not the OP. 

However, I wouldn't focus on using fat traces for avoiding copper
removal.  I think that would be the hard way to do it.  I much prefer
to create a ground polygon that encompasses the entire board and then
let the layout software figure out the actual shape.  In eagle, I put
a ground poly on both the top and bottom with isolate set to 24 mil. 
Then I route the board.  The only places eagle will take copper is for
isolation and "orphaned" copper areas (not connected to ground).
Look at http://www.geocities.com/pcbs4less/boardtop.gif for an example
of this. Red and green are copper areas/traces.  As you can see, this
design keeps much more copper than one using just fat traces.  It
seems much cleaner and makes for a quieter board, noise-wise, because
of the extensive ground areas.

Besides, thin traces just look more professional to me  :)

Phil

--- In Homebrew_PCBs@yahoogroups.com, Mycroft2152 <mycroft2152@y...>
wrote:

> Hi Phil,
> 
> Don't be hung up on very thin traces. Having wide
> traces means less copper to etch away. Only use the
> thinnest to get the circuit laid out.
> 
> You my want to post a photo of the pcb or else the
> layout for comments.
> 
> Myc

On Thu, 14 Jul 2005 09:55:36 +0200, Phil <phil1960us@...> wrote:

>
> However, I wouldn't focus on using fat traces for avoiding copper
> removal.  I think that would be the hard way to do it.  I much prefer
> to create a ground polygon that encompasses the entire board and then
> let the layout software figure out the actual shape.  In eagle, I put
> a ground poly on both the top and bottom with isolate set to 24 mil.
> Then I route the board.  The only places eagle will take copper is for
> isolation and "orphaned" copper areas (not connected to ground).
> Look at http://www.geocities.com/pcbs4less/boardtop.gif for an example
> of this. Red and green are copper areas/traces.  As you can see, this
> design keeps much more copper than one using just fat traces.  It
> seems much cleaner and makes for a quieter board, noise-wise, because
> of the extensive ground areas.
> Besides, thin traces just look more professional to me
> Phil


I agree, reasonably thin looks better.
I also make groud planes, but i always wondered about islands. You say you  
don't leave the copper there, which i only partially understand (though i  
do the same, i just don't know exactly why).

How bad are they? I mean i can imagine they could potentially provide more  
capacitive coupling between signals which is unwanted, but is that really  
an issue?
Have you any information about that?

Sometimes those gaps don't look right, and i'm tempted to leave them.

I usually use 10mil for signal traces and 20 mil for power, but i've also  
made boards with 1mm traces for customers if they want, where 10mil would  
have been plenty, and it doesn't look bad if the components are right for  
it (only throughhole, not many ICs, ..) Esp. if all traces are that wide  
and none are thinner it looks ok.

ST

I should have some time today to get copper clad board from Halted.

Has anyone tried using copper pot and pan paste for cleaning bare
copper? I wonder how that would work over an abrasive pad?

I have a gallon of Muratic acid. Not sure of the strength, but I
bought it years ago from a wholesaler. It is typically used to help
deoxidize brass when soldering car radiators. I poured some on a
driveway stain one time. It makes kind of a yellow smoke. I thought I
remember the guy telling me it was pure Muratic. Can it be used for
etching? 

Mike



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:

> On Thu, 14 Jul 2005 00:04:16 +0200, Mike Phillips <mikep_95133@y...>  
> wrote:
> 
> >
> > Maybe using the toner method would be better for proof of concept for
> > maybe 1 or 2 dozen boards, then later decide what route to take. I
> > don't mind soldering the boards myself.
> 
> 
> That's what i'd do.
> 
> ST

The reson my pcb has no ground plane is because I initially was going
the cnc route. But have been thinking that cnc may not be worth it
labor wise compared to Toner Transfer.

Mike

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Thu, 14 Jul 2005 09:55:36 +0200, Phil <phil1960us@y...> wrote:
> 
> >
> > However, I wouldn't focus on using fat traces for avoiding copper
> > removal.  I think that would be the hard way to do it.  I much prefer
> > to create a ground polygon that encompasses the entire board and then
> > let the layout software figure out the actual shape.  In eagle, I put
> > a ground poly on both the top and bottom with isolate set to 24 mil.
> > Then I route the board.  The only places eagle will take copper is for
> > isolation and "orphaned" copper areas (not connected to ground).
> > Look at http://www.geocities.com/pcbs4less/boardtop.gif for an example
> > of this. Red and green are copper areas/traces.  As you can see, this
> > design keeps much more copper than one using just fat traces.  It
> > seems much cleaner and makes for a quieter board, noise-wise, because
> > of the extensive ground areas.
> > Besides, thin traces just look more professional to me
> > Phil
> 
> 
> I agree, reasonably thin looks better.
> I also make groud planes, but i always wondered about islands. You
say you  
> don't leave the copper there, which i only partially understand
(though i  
> do the same, i just don't know exactly why).
> 
> How bad are they? I mean i can imagine they could potentially
provide more  
> capacitive coupling between signals which is unwanted, but is that
really  
> an issue?
> Have you any information about that?
> 
> Sometimes those gaps don't look right, and i'm tempted to leave them.
> 
> I usually use 10mil for signal traces and 20 mil for power, but i've
also  
> made boards with 1mm traces for customers if they want, where 10mil
would  
> have been plenty, and it doesn't look bad if the components are
right for  
> it (only throughhole, not many ICs, ..) Esp. if all traces are that
wide  

> and none are thinner it looks ok.
> 
> ST

On Thu, 14 Jul 2005 17:15:59 +0200, Mike Phillips <mikep_95133@...>  
wrote:

> I should have some time today to get copper clad board from Halted.
> Has anyone tried using copper pot and pan paste for cleaning bare
> copper? I wonder how that would work over an abrasive pad?
> I have a gallon of Muratic acid. Not sure of the strength, but I
> bought it years ago from a wholesaler. It is typically used to help
> deoxidize brass when soldering car radiators. I poured some on a
> driveway stain one time. It makes kind of a yellow smoke. I thought I
> remember the guy telling me it was pure Muratic. Can it be used for
> etching?
> Mike


You could measure the strength of the acid but i'm pretty sure it will  
work.
It's surely not "pure" hydrochloric acid, those sales guys always try to  
fool you.
When you remove the cap, do you see smoke? if you just see a tiny hint of  
smoke escaping it is around 32%, well at least in this climate.

To use it for etching you need to get some hydrogen peroxide (H2O2),  
ideally around 30%. (The 3% medical stuff has so much water that you can't  
really regenerate your etchant, because it gets diluted too much, but it  
is ok for one-time use).
Alternatively, you can use a bubbling system and air oxygen instead of the  
H2O2, but settle in for some wait.

Not sure about the pot paste. In the end you need a clean, grease-free  
surface (real clean), how you get there shouldn't matter. Let us know if  
you try.


ST

Hi Stefan,
    It is my understanding that the copper islands or orphaned copper is 
removed to help with  EMC  (or do they call it FCC in the US) approval.

You are probably right in that a fat copper island will not do any harm. 
However at very high frequencies
these isolated (in a DC sense) pieces of copper may just have the right 
shape to form L's and C's that become resonant
and hey - presto , you got yourself an antenna.

Although the chances of  a floating piece of copper  being resonant is 
probably pretty slim, when designing for EMC you take all the free runs 
that you can get

Also - When I say very high frequencies -  the signal cycle times do not 
have to be high frequencys - they just need fast transition times.


Cheers,
David




Stefan Trethan wrote:

>On Thu, 14 Jul 2005 09:55:36 +0200, Phil <phil1960us@...> wrote:
>
>  
>
>>However, I wouldn't focus on using fat traces for avoiding copper
>>removal.  I think that would be the hard way to do it.  I much prefer
>>to create a ground polygon that encompasses the entire board and then
>>let the layout software figure out the actual shape.  In eagle, I put
>>a ground poly on both the top and bottom with isolate set to 24 mil.
>>Then I route the board.  The only places eagle will take copper is for
>>isolation and "orphaned" copper areas (not connected to ground).
>>Look at http://www.geocities.com/pcbs4less/boardtop.gif for an example
>>of this. Red and green are copper areas/traces.  As you can see, this
>>design keeps much more copper than one using just fat traces.  It
>>seems much cleaner and makes for a quieter board, noise-wise, because
>>of the extensive ground areas.
>>Besides, thin traces just look more professional to me
>>Phil
>>    
>>
>
>
>I agree, reasonably thin looks better.
>I also make groud planes, but i always wondered about islands. You say you  
>don't leave the copper there, which i only partially understand (though i  
>do the same, i just don't know exactly why).
>
>How bad are they? I mean i can imagine they could potentially provide more  
>capacitive coupling between signals which is unwanted, but is that really  
>an issue?
>Have you any information about that?
>
>Sometimes those gaps don't look right, and i'm tempted to leave them.
>
>I usually use 10mil for signal traces and 20 mil for power, but i've also  
>made boards with 1mm traces for customers if they want, where 10mil would  
>have been plenty, and it doesn't look bad if the components are right for  
>it (only throughhole, not many ICs, ..) Esp. if all traces are that wide  
>and none are thinner it looks ok.
>
>ST
>
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>If Files or Photos are running short of space, post them here:
>http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>
> 
> ** ACCEPT: CRM114 PASS Markovian Matcher ** 
>CLASSIFY succeeds; success probability: 1.0000  pR: 75.3676
>Best match to file #0 (nonspam.css) prob: 1.0000  pR: 75.3676  
>Total features in input file: 7075
>#0 (nonspam.css): features: 1444288, hits: 289711, prob: 1.00e+00, pR:  75.37 
>#1 (spam.css): features: 554608, hits: 88467, prob: 4.29e-76, pR: -75.37 
> 
>
>-=-Extra Stuff-=-
>
>  From sentto-4505361-9835-1121335815-yahoo=dcureton.com@... Thu Jul 14 20:10:50 2005
>Return-path: <sentto-4505361-9835-1121335815-yahoo=dcureton.com@...>
>Envelope-to: yahoo@...
>Delivery-date: Thu, 14 Jul 2005 20:10:50 +1000
>Received: from n10.bulk.dcn.yahoo.com ([216.155.201.63])
>	by whitetail with smtp (Exim 4.34)
>	id 1Dt0g5-0004wZ-6G
>	for yahoo@...; Thu, 14 Jul 2005 20:10:49 +1000
>Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys
>DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=lima; d=yahoogroups.com;
>	b=Lb4DZCCehu3oAy78nYfZeu+7BDSrOiZZrHZQ5hCwm4hl4xridI2icJdqPe3ctklw2D4hKWCqeQr/ezqKR2yZdMhfQ83Vb6EH43qSLCDE1Mn8ldxv4QsahkJpW9jJf9Yo;
>Received: from [216.155.201.65] by n10.bulk.dcn.yahoo.com with NNFMP; 14 Jul 2005 10:10:15 -0000
>Received: from [66.218.69.3] by mailer2.bulk.dcn.yahoo.com with NNFMP; 14 Jul 2005 10:10:15 -0000
>Received: from [66.218.66.29] by mailer3.bulk.scd.yahoo.com with NNFMP; 14 Jul 2005 10:10:15 -0000
>X-Yahoo-Newman-Property: groups-email
>X-Sender: stefan_trethan@...
>X-Apparently-To: Homebrew_PCBs@yahoogroups.com
>Received: (qmail 22942 invoked from network); 14 Jul 2005 10:10:14 -0000
>Received: from unknown (66.218.66.216)
>  by m23.grp.scd.yahoo.com with QMQP; 14 Jul 2005 10:10:14 -0000
>Received: from unknown (HELO mail.gmx.net) (213.165.64.20)
>  by mta1.grp.scd.yahoo.com with SMTP; 14 Jul 2005 10:10:13 -0000
>Received: (qmail invoked by alias); 14 Jul 2005 10:08:01 -0000
>Received: from v211-056.vps.tuwien.ac.at (EHLO tu-x2pj5qeyp2u4) [128.131.211.56]
>  by mail.gmx.net (mp008) with SMTP; 14 Jul 2005 12:08:01 +0200
>X-Authenticated: #9664799
>To: Homebrew_PCBs@yahoogroups.com
>References: <db55po+ei0u@...>
>Message-ID: <op.stwefmsbmg0lsf@tu-x2pj5qeyp2u4>
>In-Reply-To: <db55po+ei0u@...>
>User-Agent: Opera M2/8.01 (Win32, build 7642)
>X-Y-GMX-Trusted: 0
>>X-eGroups-Msg-Info: 1:12:0
> From: "Stefan Trethan" <stefan_trethan@...>
>X-Yahoo-Profile: stefan_trethan
>Sender: Homebrew_PCBs@yahoogroups.com
>MIME-Version: 1.0
>Mailing-List: list Homebrew_PCBs@yahoogroups.com; contact Homebrew_PCBs-owner@yahoogroups.com
>Delivered-To: mailing list Homebrew_PCBs@yahoogroups.com
>List-Id: <Homebrew_PCBs.yahoogroups.com>
>Precedence: bulk
>List-Unsubscribe: <mailto:Homebrew_PCBs-unsubscribe@yahoogroups.com>
>Date: Thu, 14 Jul 2005 12:08:00 +0200
>Subject: Re: [Homebrew_PCBs] Re: Another rookie starts a high volume pcb project.
>Reply-To: Homebrew_PCBs@yahoogroups.com
>Content-Type: text/plain; charset=iso-8859-15
>Content-Transfer-Encoding: 7bit
>
>On Thu, 14 Jul 2005 09:55:36 +0200, Phil <phil1960us@...> wrote:
>
>  
>
>>However, I wouldn't focus on using fat traces for avoiding copper
>>removal.  I think that would be the hard way to do it.  I much prefer
>>to create a ground polygon that encompasses the entire board and then
>>let the layout software figure out the actual shape.  In eagle, I put
>>a ground poly on both the top and bottom with isolate set to 24 mil.
>>Then I route the board.  The only places eagle will take copper is for
>>isolation and "orphaned" copper areas (not connected to ground).
>>Look at http://www.geocities.com/pcbs4less/boardtop.gif for an example
>>of this. Red and green are copper areas/traces.  As you can see, this
>>design keeps much more copper than one using just fat traces.  It
>>seems much cleaner and makes for a quieter board, noise-wise, because
>>of the extensive ground areas.
>>Besides, thin traces just look more professional to me
>>Phil
>>    
>>
>
>
>I agree, reasonably thin looks better.
>I also make groud planes, but i always wondered about islands. You say you  
>don't leave the copper there, which i only partially understand (though i  
>do the same, i just don't know exactly why).
>
>How bad are they? I mean i can imagine they could potentially provide more  
>capacitive coupling between signals which is unwanted, but is that really  
>an issue?
>Have you any information about that?
>
>Sometimes those gaps don't look right, and i'm tempted to leave them.
>
>I usually use 10mil for signal traces and 20 mil for power, but i've also  
>made boards with 1mm traces for customers if they want, where 10mil would  
>have been plenty, and it doesn't look bad if the components are right for  
>it (only throughhole, not many ICs, ..) Esp. if all traces are that wide  
>and none are thinner it looks ok.
>
>ST
>
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>If Files or Photos are running short of space, post them here:
>http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>
> 
>  
>  
> -0-0-0- 
>  
>

I'm not expert on this but I saw (somewhere) a discussion of
capacitive coupling as an issue.  Especially at higher frequencies. 
  
Phil

--- In Homebrew_PCBs@yahoogroups.com, David Cureton <yahoo@d...> wrote:
> Hi Stefan,
>     It is my understanding that the copper islands or orphaned
copper is 
> removed to help with  EMC  (or do they call it FCC in the US) approval.
> 
> You are probably right in that a fat copper island will not do any
harm. 
> However at very high frequencies
> these isolated (in a DC sense) pieces of copper may just have the right 
> shape to form L's and C's that become resonant
> and hey - presto , you got yourself an antenna.
> 
> Although the chances of  a floating piece of copper  being resonant is 
> probably pretty slim, when designing for EMC you take all the free runs 
> that you can get
> 
> Also - When I say very high frequencies -  the signal cycle times do
not 

> have to be high frequencys - they just need fast transition times.
> 
> 
> Cheers,
> David
> 
> 
>

You were correct. The bottle is labeled 32.something percent. Where
might I generally find 30% Hydrogen Peroxide? I wonder a bottle from
Radio Shack would be easier?

Mike



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Thu, 14 Jul 2005 17:15:59 +0200, Mike Phillips <mikep_95133@y...>  
> wrote:
> 
> > I should have some time today to get copper clad board from Halted.
> > Has anyone tried using copper pot and pan paste for cleaning bare
> > copper? I wonder how that would work over an abrasive pad?
> > I have a gallon of Muratic acid. Not sure of the strength, but I
> > bought it years ago from a wholesaler. It is typically used to help
> > deoxidize brass when soldering car radiators. I poured some on a
> > driveway stain one time. It makes kind of a yellow smoke. I thought I
> > remember the guy telling me it was pure Muratic. Can it be used for
> > etching?
> > Mike
> 
> 
> You could measure the strength of the acid but i'm pretty sure it will  
> work.
> It's surely not "pure" hydrochloric acid, those sales guys always
try to  
> fool you.
> When you remove the cap, do you see smoke? if you just see a tiny
hint of  
> smoke escaping it is around 32%, well at least in this climate.
> 
> To use it for etching you need to get some hydrogen peroxide (H2O2),  
> ideally around 30%. (The 3% medical stuff has so much water that you
can't  
> really regenerate your etchant, because it gets diluted too much,
but it  
> is ok for one-time use).
> Alternatively, you can use a bubbling system and air oxygen instead
of the  
> H2O2, but settle in for some wait.
> 
> Not sure about the pot paste. In the end you need a clean, grease-free  
> surface (real clean), how you get there shouldn't matter. Let us
know if  

> you try.
> 
> 
> ST

On Thu, 21 Jul 2005 16:44:33 +0200, Mike Phillips <mikep_95133@...>  
wrote:

> You were correct. The bottle is labeled 32.something percent. Where
> might I generally find 30% Hydrogen Peroxide? I wonder a bottle from
> Radio Shack would be easier?
> Mike


i go to a shop that sells chemicals, there is get everything i want really  
cheap and they even refill bottles etc. so you only pay per weight.
There are swimming pool chemicals here that are 20% H2O2, but more  
expensive than the 30% stuff from the shop.

ST

--- In Homebrew_PCBs@yahoogroups.com, "Mike Phillips"
<mikep_95133@y...> wrote:
> I posted a panel of the pcb for my truck project. It's in the folder
> labeled Mikep_95133's.
> 
> Glad to know that 12 mil is not so bad.
> 
> Mike
> 

Just going thru the old posts (still looking for the best paper these
days. I remember when it changed weekly on this list....)

Anyway, the posted file with multiple boards looks nice, but a comment
I would make is to pack them more tightly together.  There may not be
room for this project, but typically board houses charge for size and
there is a huge gap between boards that migh increase the total cost
by 50%.  

I do understand that most of us have specific sized boards to work
with and scrap cannot be helped, so this may not apply to this
project, so, this may be more of comment for others.

Also, Home Depot sells a wet diamond tle saw for under $100 so you can
cut the boards very closely.  Some people like to shear them with a
different type tool but the one benifit of the saw is in doing notches
in corners.

Dave