>From: "Leon Heller" <leon_heller@...>
>Reply-To: Homebrew_PCBs@yahoogroups.com
>To: Homebrew_PCBs@yahoogroups.com
>Subject: Re: [Homebrew_PCBs] Oh no, blank fibreglass again!
>Date: Sat, 26 Apr 2003 18:10:29 +0000
>
>Professional PCB suppliers use a different etching chemistry - I think it's
>based on ammonia, it's alkaline, anyway. Perhaps that doesn't affect the
>tin.
I've just checked the above with a web search, and it's basically correct.
The etchant is ammonia, ammonium chloride and cupric chloride. The excess
copper needs to be removed regularly. This stuff doesn't dissolve tin or
tin/lead, unlike FeCl3 and other acidic etchants.
Leon
--
Leon Heller, G1HSM Tel: +44 1424 423947
Email:
leon_heller@...My web page:
http://www.geocities.com/leon_heller_________________________________________________________________
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