William K. Borsum wrote:
>
> At 12:15 AM 11/27/99 -0800, you wrote:
> >Related question for the group;  I will have the capability to plate
> >gold onto copper (or nickel or most anything else) pretty soon here;  Is
> >there an etchant that could be used, that would let me use gold as an
> >etch resist?  Ferric Chloride will (if hot at least) eat gold, IIRC,
> >just curious if this is possible;  it's definitely unusual, I know <G>
>
> There was an ammonium persulfate (???) based etchant that was available in
> the hobby market for a while.
> Might try that.  Nitric and sulfuric acids might work too--bit of a
> handling problem though.
>
> I know a number of board houses that do work for HP use gold as a
> resist--and Tin/lead is commonly used as a resist.
> Would like to hear what you learn.
>
> Kelly
>
> William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems
> <borsum@dascor.com> & <www.dascor.com>San Diego, California, USA

<G>  Nitric or sulphuric, a problem?  The mining folks I talk to always
have those on hand, and my dad's a research chemist, WHAT handling
problem?  (A fume hood can be a good idea...)  I could just hand the
boards off to him to etch at work <G>

HF, now, HCN, or SO2, THOSE can be dangerous...

I'll share info, no problem <G>  I've wondered about using EDM machining
for making PCB's, also, but I have more curiousity than time to do
research...  It's so slow, I've passed on it.

  Mark

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