"Zoran A. Scepanovic" wrote:
> Hello Adam,
>
> Friday, April 19, 2002, 5:04:15 AM, you wrote:
>
> AS> Has anyone out there done copper etching with ammonia
> AS> hydroxide and copper sulfate solution ? I'm interested in
> AS> learning new ways of making the ammonical etching tank for
> AS> hobbyist. Currently I have a working etching tank based on
> AS> this chemistry. The major problem witht his type of etchant
> AS> is ammonia fumes. The way I solved this was to build a
> AS> sealed tank and have a slotted opening on the lid for
> AS> inserting the PCB. When the tank is not in use the slot is
> AS> sealed with a rubber strip leaving the tank almost air
> AS> tight. I would like to here what others have done.
>
> AS> Adam S
>
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> And I replied:
>
> Why ammonia? For homemade PCB's good results can be achieved using
> combination of CuCl and HCl. No fumes and can be bubble assisted.
>
> --
Thanks Zoran for your reply. It so happens that I need to selectively etch copper
and not attack tin metal. Ammonia/sulfate etchant can magically do this (I would
love to know the reasons why). Even aluminum and iron are safe in this solution.
Its unfortunate that almost zero literature exists on the subject.
How is your success with CuCl2 + HCl ? What are the concentrations used ? This
sounds like a good etchant I could use for normal PCB's.