Gareth,

out of interest, what sort of etch rates do you get for sodalime glass with
that etchant?

thanks,

Paul

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Gareth Jenkins
Sent: 09 May 2006 14:17
To: General MEMS discussion
Subject: Re: [mems-talk] Ammonium fluoride


Rupesh Sawant wrote:

> Hi,
>    I want to make NH4F (Ammonium fluoride) in my lab for etching
> glass. The concentration of Ammonium Fluoride required is 40%.


I assume this is to buffer a solution containing HF.
Are you talking about semiconductor grade? Standard (non-semiconductor
grade) is fine for microfluidics and isn't expensive.
You could also consider using an aqueous solution with 2% conc. HF + 2%
conc. HNO3 instead. This gives very nice results for soda-lime glass.

Gareth