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

Grant,

The UV etch resist ink I use was made by LeaRonal in Freeport, NY but
they are no longer around. They were bought out by another firm but I
can't remember who that was. There are several suppliers who offer
these inks, check out Enthone and MacDermid. If a supplier offers
soldermask, they will usually have the etch resist. I had a gallon of
this ink left over from my commercial shop and even though its date
code had expired it still works good. We thin the ink a bit with a
special solvent for UV inks.

If you are just getting started with screen printing I would suggest
getting the air dry etch resist. This type of resist is inexpensive
and works good. Buy the smallest quantity they offer. These inks will
cover about 3000 square feet per gallon when using a 305 mesh
polyester screen.

If you want to try out the soldermasking process get a single or two
part epoxy soldermask. You can use an old electric kitchen oven to
cure the soldermask. It takes about 30 to 60 minute to cure depending
on the temperature. This really makes your boards look good.

BTW, the screen printing emulsions are negative acting so you will
need positive films emulsion side up.

Tom