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Message-ID: <34ED9BAB.814A4066@advanct.com>
Date: Fri, 20 Feb 1998 10:05:15 -0500
From: "David W. Sherrer" 
Organization: Advanced Coating Technologies
X-Mailer: Mozilla 4.04 [en] (Win95; I)
MIME-Version: 1.0
To: Andrew CAMPITELLI 
Subject: Re: transparent Au etchant...
References: <199802200608.WAA27377@darkstar.isi.edu>
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Andrew,

Potassium Cyanide or Sodium Cyanide  in water will dissolve gold and is
transparent. It is common in the plating industry.  Etching is accelerated with
H2O2, but the bubbling may produce visibility problems if that is a concern. You
can use about 12 -16 oz/gal heated slightly or room temp. Conc. H2O2 is then
added (several tens of ml / gal.)   Be careful in handling as KCN is very
dangerous. Mixture with acids released HCN gas.  Review the MSDS.  Place the
container in a sink as rapid evolution of gas may produce boil-over. If the
solution becomes non-transparent you probably need more cyanide. If there
gassing
stops, add more H2O2.

Good Luck,

David Sherrer
dsherrer@advanct.com
www.advanct.com



Andrew CAMPITELLI wrote:

> Dear Colleagues,
> I am searching for a supplier for a gold etchant that is transparent (clear).
> We are currently using a KI solution, which works well but has the major
> disadvantage of being non-transparent.
> Any suggestions would be greatly appreciated.
> Thank you.
> Andrew
>
>