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

Tried a couple of things today, I'll lump them together here.

Since modding my GBC to have temperature control, I'd wanted to try
toner transfer again. Today I ran the laminator up to 350 F (the
default was 320 F before, so this is 30 F hotter than my previous TT
attempts). The paper was Pulsar blue, the printer HP 2550N, just like
before. The paper stuck the first time, but I did all four passes
anyway (once in each direction). Got a perfect transfer! Granted,
this board used larger traces than normal (23 mil) but before I'd have
traces just floating away rather than stick. I added the green TRF
with only one pass, it stuck perfectly.

Since it was a SS board (recall that I etch the two sides separately,
then sticky-tape them together), I used some double-sided tape to
stick the board to the end of a stick, and used that to dip it into
the etchant and swirl it around. Handy - I could just lift it out,
inspect, put it back in. Etched fine.

I also tried something new with the UV photofilm. I set the laminator
at 240 F (I'm really liking this temperature control). I went extreme
wet method - after cleaning the board with a scrubbie and some 2000
grit sandpaper, I rinsed it well and dropped it into a container of
water. Yup, fully submerged. I removed the one backing off the film,
rinsed that as well (on a transparency as usual), then submerged that
in the water as well. While both the film and board were underwater,
I swirled them around to make sure there were no air bubbles sticking
to either, lined the two of them up, held one corner together, and
lifted them out of the water. There were some weird creases in the
film (it wasn't sticking yet, so I took it off, looked at it, and
redid it) but otherwise, the film stuck better than it had ever
before. I put the combo on a flat board, covered with transparency,
and squeegied the remaining water out. One pass through the laminator
and, except for the weird creases, it stuck great. I let it sit while
doing the other board, and it's nearly (but not 100%) perfect.

I suspect that warming the water to room temperature might be better
for the film; my cold water is pretty cold.