I've tried out Chucks's suggested paper, and a couple
of other re-purposed alternatives. they certainly
work, but it took a while to soak off, and I always
had trouble cleaning off the paper residue that
remains stuck. For a while even I tried working with
the "Press'N Peel Blue" plastic transfer film (more
costly, but at the time it was on the boss's nickel).
But I was convinced on the spot the first time I used
the Pulsar paper stuff and saw it just float off the
board in about a minute, leaving nothing but toner and
clean copper behind - ready to pop directly into the
etch bath.
The raw deposited toner has some porosity and pitting
can be seen under magnification. Not nearly enough to
be damaging unless traces are really thin. Recently
I've started using the"Toner Reactive Foil" product as
well and find a much cleaner surface to the un-etched
copper and ability to get consistent traces down under
10 mils. The foil pretty much eliminates the pitting.
Now, for DIY, I just about never use traces smaller
than 15 mils, but some of the text legends and such
that I'll etch for ID will have lines of 6 or 8 mils,
and they usually come out clean.
If you were going to do a "mini mass production" of
maybe a few dozen boards (I did that once for a club
kit - never again, the drilling was a drudge - hi), a
more economical alternative paper is not a bad idea.
But nowadays my DIY boards are just about always
one-off, Then if it turns out to be a useful project
that others might have interest in, off it goes to a
fab house. Nick and I will talk about the "gotchas"
for that process. There aren't many, but they are
important..... ask me how I know :^))
If you like Pittsburg style, or SMT, where drilling
can be mostly avoided, the DIY route is really
attractive, even for modest quantities.
Jim, N5IB
