> -----Original Message-----
>
>          i'm ramakrishna working with quartz micromachining
> project.
> i need thru hole on this quartz substrate.
>
> T.Ramakrishna,

Hi,

For deep glass etching, you can also consider Powder Blasting. The feature
sizes are only down to 30 micron, but the process is fast and very suitable
for bulk glass etching, especially through holes. For more information on
this subject see:
http://www.el.utwente.nl/tt/projects/blast/

Greets,

Henk



Ir. H. Wensink
EL/TN room T502
MESA+ Research Institute
University of Twente
P.O. Box 217, 7500 AE Enschede
The Netherlands
Phone:  x31-53-4894373 (direct), x31-53-4892751 (secretary),
Fax:  x31-53-4893343
http://www.el.utwente.nl/tt/projects/blast/