Homebrew PCBs

On Sun, 29 May 2016 00:01:43 -0700, you wrote:

>>
>Harvy -
>
>You really need to get the Adam Sechelle (sp?) article on CuCl etching.  
>It explains the chemistry involved in removing the copper.  Just putting 
>salt (NaCl) in water won't release free Cl ions.  When the copper is 
>removed, it has to go somewhere, and that is into solution as CuCl.  The 
>etching (removal of the copper)***/relies /*on the formation of CuCl and 
>the reversible reaction between CuCl+ and CuCl++.  I know this isn't 
>what you want to hear, but the chemistry is factual.

Ok, so then the ammonium persulphate etching works (obviously)
different.  I'm trying to duplicate *that* process without having to
buy expensive ammonium persulphate, or if I do, then figure out a way
to regenerate it.

It's the free hydrogen ions (I guess) that do in the plastic, or
perhaps the chlorine ions.

With ammonium persulphate, I'm guessing ammonium sulphate and lots of
free oxygen, which suggests copper sulphate as a possible outcome. In
which case we get oxidized copper somehow or somewhere.  Guess I'd
better look up the chemistry on that one.

Harvey

>
>Norm