Dissolve epoxy glass but not copper?

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

Thanks!
Antony

 

[CWatters]

Would a 35u thick stencil be any use?


<antony@INVALID.com> wrote in message
news:bqa359$20fe5k$4@ID-50260.news.uni-berlin.de...

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

Thanks!
Antony

 

[Baphomet]

<antony@INVALID.com> wrote in message
news:bqa359$20fe5k$4@ID-50260.news.uni-berlin.de...

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

Thanks!
Antony

I have a sneaking suspicion that if this could be done, it would turn out to
be a very expensive way to make a stencil.

 

[Ian Stirling]

antony@invalid.com wrote:

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

I'd suggest that you get a working news program that crossposts, rather

than posting the same message to many groups.
Perhaps heat.
300C or so will degrade epoxy so you can just lift the copper off.

 

[Ross Mac]

<antony@INVALID.com> wrote in message
news:bqa359$20fe5k$4@ID-50260.news.uni-berlin.de...

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

Thanks!
Antony

If all you need is a copper stencil you might do best just to have a circuit
board shop print and etch some copper for you....you might get a little bit
of etch back, but am not sure what kind of detail you are attempting
here....good luck, Ross

 

[Ross Mac]

"CWatters" <colin.watters@pandoraBOX.be> wrote in message
news:rw0yb.50293$yO2.1718407@phobos.telenet-ops.be...

Would a 35u thick stencil be any use?


antony@INVALID.com> wrote in message
news:bqa359$20fe5k$4@ID-50260.news.uni-berlin.de...

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

Thanks!
Antony



Good question, that equates to, I believe, 1 ounce per square of copper on

FR4 material....just over a mil.....darn thing would be a wrinkle looking
for a place to happen!

 

[Richard Crowley]

<antony@INVALID.com> wrote ...-

Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

We used to use Acetone or Methyl-Ethyl-Ketone as solvents for
various polyester and epoxy resins used in the fiberglass biz.

I'm trying to find a cheap way for making stencils.

Um, dissolving a fully set-up (hardened) board to make a stencil
is a really bad idea IMHO. It would take forever to dissolve the
epoxy, you'd end up with a sticky mess, and (as has already been
observed) you'd likely end up with a "stencil" too thin to be
used practically. This is why screen-printing was invented!

 

[Ross Mac]

<antony@INVALID.com> wrote in message
news:bqa359$20fe5k$4@ID-50260.news.uni-berlin.de...

Hi!
Is there any chemical substance capable of completely dissolving
epoxy glass, 1.6 mm thick, but not dissolving at all the 35 uM
copper that coats it? (it's a photoetched printed circuit board)

I'm trying to find a cheap way for making stencils.

Thanks!
Antony

I believe the chemical that is used in the PCB biz to disolve fiberglass/FR4

is called Permanganate....A nasty dark purple chemistry. They use it to
clean out drilled holes before the electroless copper process. I don't think
you would want to go here but ....what the heck...that's how it's
done.....Ross