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

 

[Johnboy]

There is a pink liquid that I have used back in the '60's to do what
you want. I used it many years ago for quality testing of our plants
PC board mfg. process. We would dissolve the board, pick out the
traces from the glass residue and then examine these them for
undercutting. Nowadays there are far superior methods than this
awkward process. There might be a chance that the product is still
around, look on PCB quality control industrial web sites.

<antony@INVALID.com> wrote in message
news:bqa357$20fe5k$1@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

 

[Al]

In article <bqa357$20fe5k$1@ID-50260.news.uni-berlin.de>,
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.

You can buy what you want from a distributer. Here is the web site for
the manufacturer of epoxy strippers:

http://www.dynaloy.com/INDepox.htm

The problem with epoxies is that they really don't dissolve well. They
swell and break up.

Tetramethyl Guanidine works as a good solvent, but it is nasty stuff.

Al

--
There's never enough time to do it right the first time.......

 

[Gary Tait]

On 29 Nov 2003 12:24:08 GMT, 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.

Thanks!
Antony

Why not silkscreen?
How about laset cutting the stencil material?