Homebrew PCBs

"Peter Johansson rockets4kids@... [Homebrew_PCBs]"
<Homebrew_PCBs@yahoogroups.com> writes:
> 1.  30% HCl works brilliantly for cleaning any tarnish off a board.
> Just wipes it right off like magic.

That's because the tarnish is copper *oxide*, and as I mentioned
earlier, HCl needs an oxidizer - so it etches the copper oxide but can't
etch the copper.  Be careful, though, HCl is a nasty chemical to work
around.  Note that copper oxide is also one of the possible starters for
a CuCl etchant - which *will* etch copper.

Me, I use a green scrubbie.  Prepping a board for TT or UV is more than
just cleaning the copper - you need to make a mechanically rough surface
for the toner to cling, and the scrubbie does that.  Toner won't stick
well (or at all) to a mirror finish (which is why it releases from
transparencies).

> 2.  It is ridiculously easy to tin your entire board using nothing
> more than a broad-tipped iron.

Unless you're doing fine-pitch surface mount parts, in which case the
uneven surface of the solder messes you up a lot.

Liquid tin is a lot easier to do, too, and you don't risk lifting the
copper traces off the pcb.