One more method, Powder blasting,
we got the holes drilled in glass(pyrex 500 micron thick) by powder
blasting from external vendor, but the holes are tapered, 200 micron
opening at one side and 500 micron at other side.

for about 40 holes on a wafer one may charge $200.

======================
Ashwini Jambhalikar

On Mon, Sep 26, 2011 at 9:51 PM, Matthieu Nannini, Dr.
 wrote:
> Hi,
>
> Not sure you'll find anything using plasma etch. Average etch rate of glass in
3-4kW ICPs is 0.2-0.3um/min. People had deep etches using a thick electroplatted
Ni mask. Never heard of TGV (thru Glass vias) made by plasma etch, I'm not on
top of the literature though.
>
> Making holes thru glass wafers can be done in several other ways, it all
depends on the size and density of the hole you want to drill:
> - ultrasonic drilling (costs is about 200$ per wafer and there an initial
tooling cost to add)
> - laser drilling
> - manual diamond bit drilling (we do that for process development: time
consuming but cheap and fast to get holes down to 400um in diam)
> - HF:HCl wet etch but you'd need a thick aSi hard mask and holes will be
pretty large
>
> HTH