The HCl is the only ingredient that I can forsee causing me grief.
I'm using a CuCl2 + HCl (1.3 molar). Typically, I'm etching at about
125F with a rotary spray etching machine (my own elaborate creation).
Typical processing is under 1 minute for 1oz boards. Additional
upside is that undercut is really minimized with this setup, however,
the higher temp solution is far more aggressive to the resist, so
timing and resist quality are of the utmost importance.
For anyone aspiring to duplicate this setup, don't try this at home
without a lab type fume hood. HCl at 125F is exceptionally unpleasant
stuff to work with, you'd rather not get a lung full of the fumes.
Dave
--- In Homebrew_PCBs@yahoogroups.com, "jam5411" <mardock@...> wrote:
>
> Using the MS-PRO inks, properly applied and "cured" I find to be an
> excellent resist to freshly mixed HCL/H2O2, which appears to me to be
> a more aggresive etchant than the FeCL I have used.
>
> John