Novak,

According to CRC's Handbook of Metal Etchants (pg. 198), an aqueous Ferric
Chloride solution may work. To quote: "Solution used as a general etch for
metals to include irons, steel, and nickel." The concentration is annoyingly
given in terms of density (30-35 Baume). Temperature is "RT to hot."

I know you can get this stuff cheaply in most PCB etching kits, so no
problem there. As for what it will do to magnesium diboride though... no
idea.

If that turns out to be problematic, perhaps try an electrochemical etch
instead?

Kevin Paul Nichols
MESA+ Institute for Nanotechnology
Mesoscale Chemical Systems
Meander 151
University of Twente
Postbus 217
7500 AE Enschede
The Netherlands

Office: +31 (0)53 489 26 31
Mobile: +31 (0)6 49 312 471
Fax   : +31 (0)53 489 35 95
Email : k.p.nichols@utwente.nl
Web   : http://mcs.tnw.utwente.nl/


> From: Novak Farrington 
> Reply-To: General MEMS discussion 
> Date: Fri, 2 May 2008 18:17:02 +0100
> To: 
> Cc: 
> Subject: [mems-talk] Wet chemical etch for 316L stainless steel
>
> Hi All,
>
> Does anyone know of a wet chemical etch for 316L stainless steel? We're
> trying to uniformly etch away, or at least thin, 100um of stainless steel
> from a magnesium diboride core. It would be nice if the magnesium diboride
> core was not etched, or at least etched at a much slower rate than the
> stainless steel.