Homebrew PCBs

On 26 Dec 2016 11:13:09 -0800, you wrote:

>Your traces are awfully wide.   I would like to see experiments with more narrow traces.
>
>This stuff looks interesting for transfers for things like silk layers and labeling project boxes.
>
>But from my reading it looks like you now have 2 transfers to worry about. One for the toner, one for the foil.    What is the advantage here other than some cool colors?

The green foil is used to seal the toner for microscopic holes.  It
does work, and is a bit harder than just the toner, although it can be
scratched.  It won't rub off as easily as toner might.

The same approach may be used after etching (and gluing the boards
together if you do that).  Print the silk screen layer on the paper
you use (or directly print it on the board... if you do), then use the
white TRF foil to simulate a silk screen.

It (at least, the pulsar version), is thicker and comes off in pieces.
I use masking tape (not aggressive) to pick up the remnants.  The part
bonded to the toner generally stays, the free floating parts don't.

I have not yet tried color toner to make a multi-colored board,
although that is a possibility.

I've stopped doing silk screen layers, though.

My board preparation is generally scrubbing with bon-ami (or an
abrasive cleanser that has some metal brighteners in it), then
roughing up with 1000 or 1200 grit paper.  Force air dry it with a
hair dryer (it may discolor, depending on your water, never had a
problem), then an acetone rub with a lint free cloth.

Toner transfer as usual.  (I go from laminator to water directly, it
seems to minimize cracking).  When the board is still wet, dry it off
with a hair dryer, it will be somewhat warm, which is ok.  Then put on
the green TRF.  Allow that to cool completely.  The parts of the TRF
over the toner should transfer completely.

Etch, tin plate if desired, drill pilot holes, epoxy the bottom to the
top, allow to completely cure, drill holes, mount parts.

Harvey