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

having a positive etching problem
I'm using precoated boards, using double pcb masks to
expose boards, sandwiching 2 laser printouts on top of
each other. tried single, but did same thing.

exposure 3 1/2 minutes at 11 inches from uv lamp. developer
step looks sharp, but it may be too thin.
tried 3 minutes with single transparancy but looks the same.

on etching they look porous on most of
the traces. doing 3 circuits at once on one board.

typical exposure setup routine,/board / mask / glass cover
i'm using .040 to .060 traces.

tinit .. made up 2 different batches of this stuff and it
didn't do a thing. mixed it with a digital thermometer too!
ain't nuttin goin right. ha ha. figure worst case I can
drill the boards then flow some solder over the porous sections
then clean out the drill thru's.


using bubbler in etchant ferric cloride
getting agrivated at the junk they sell now days..

Think I may pickup one of those silk screen kits see what it does.
jim
nc4fl