Lanzy,

I have never been successful in wet etching glass substrates
for any considerable time (ie more than a few tens of microns)
without the masking material degrading.  The best masking
layer I have used was chrome with an adhesion layer of gold,
but even this had a limited lifetime.

However, there are other techniques that I have used with
successful including:

-using a high speed drill
-ultrasonic drilling
-electro-discharge machining

The last one is a cheap and dirty solution but can be
done in-house.

-Michael











>Dear all,
>I want to etch through the 7740 glass wafer which is 0.5mm thick.
>What kind of material can I use as the mask for etching? I tried PR
>and Gold but both failed. I wonder whether you have some expirience
>to share with me.
>Thank you so much.
>
>Best regards,
>Lanzy
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