drmail377 wrote:
> This has probably been raised before; but has anyone tried this for putting etch resist on PCB's?
No, but it fits the first requirement -- "it looks like it might work".
I wouldn't use sign vinyl though -- in fact, I'd try and find some form of
photoresist coating for screen-printing. A few years ago I was thumbing
through a catalogue for a British company called "Specialist Crafts", who
supplied all manner of arts-and-crafts products... including screen-printing
equipment. One of the things they sold was a liquid that could be painted on
to silk-screens, left to dry, then exposed to light (probably UV, or maybe
bright sunlight), and then rinsed in water to remove the exposed mask. Once
you'd finished, you cleaned the screen with a solvent to remove the rest of
the mask.
Unfortunately I can't for the life of me remember what this stuff was called,
and it doesn't seem to be on their website either (for that matter, about half
of their product range seems to have vanished)...
Removing the 'track' vinyl whilst leaving the masks for small areas (e.g. dots
inside pads) would probably be quite difficult. I suspect the cost/benefit
ratio would be quite low for something like this... and that's assuming you
could find a screen-printable ink or dye that's resistant to etchant.
Thinking along similar lines, aren't most PCBs "silkscreened" by applying a
photo-resist like coating to the PCB, hitting it with UV light, then
developing with $NASTY_CHEMICAL to remove the areas that were exposed to UV?
Sort of like how solder resist is typically applied?
--
Phil.
ygroups@...http://www.philpem.me.uk/