Homebrew PCBs

On Monday 03 March 2003 12:06 am, rolanyang <rolan@...> 
wrote:
> I had a chance to play around with some CuCl2 (Cupric Chloride)
> etching last Friday and performed a test etch with a small segment
> of PCB created using the "cheap paper laser toner-transfer method".
> The traces are 10 mil in width.
>
> You can see check out some pics at
>
> http://www.techfreakz.org/~rolan/mypics/cucl2/
>
> The neat thing about using CuCl2 is that the byproduct
> of the etching process generates more CuCl2. And because of
> this, the etchant solution can be used over and over.

No, the etching reaction (a reduction reaction) generates CuCl . 

Cu + CuCl2 => 2 CuCl

People do regenerate the etchant using oxidizers (like chlorine gas or 
hydrogen peroxide).

2 CuCl + H202 + 2 HCl => 2 CuCl2 + 2 H2O

2CuCl + Cl2 => 2 CuCl2

-- 
Ned Konz
http://bike-nomad.com
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