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
Would a 35u thick stencil be any use?
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.
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.
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
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!
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We used to use Acetone or Methyl-Ethyl-Ketone as solvents for various polyester and epoxy resins used in the fiberglass biz.
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!
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
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