Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

OK, so I got interested and burned some google cycles... forgive me
if this is old stuff that goes nowhere.

It seems that inkjet printers use pretty standard water-based inks.
They carry the pigment (called colorants) to paper. These are
particles in suspension. While the formulations are some what
special for viscosity and surface tension, they are pretty standard.
So spraying down a non-water based ink is probably out but it does
seem possible to lay down a water based ink pattern on copper. The
big issue is what happens once it hits the etch tank - the inks tend
to run.

Now what if there was an additive/pigment that consisted of particles
of a solid, water insoluable substance that had a melting point below
the melting point of PCB substrate materials. Then you could print
the pattern and put it in the oven to cause the resist particles to
melt and fuse. Removal would be via a solvent.

Or, I know that there are water based polyurathane paints, I think
that these cure to be reasonably water resistant and thus could form
a resist. It would have to be thinned a lot, of course. There are
also companies that makes the poly additive so it could just be added
to a standard inkjet formulation. There are solvents that clean this
stuff up after it has dried/cured.

Finally, what about an ink that is a UV sensitive component (like the
coatings of presensitized PCBs). Print and expose to UV to cure.

Thoughts?


maybe that acetone is worse than I though... LOL