The circular die may be cut using an ultrasonic cutter.  The one I use is
very old and made by Bullen Ultrasonics.  I mount the substrate on a piece
of glass with Stronghold wax before cutting.  Though Bullen no longer
manufactures the equipment, they do provide ultrasonic machining services in
Ohio.  The phone is (937) 456-7133.

I have also seen silicon cut with a similar machine made by Buhler
-----Original Message-----
From: John D. Evans 
To: MEMS@ISI.EDU 
Date: Tuesday, April 27, 1999 7:14 AM
Subject: Dicing into circular quartz dice


>
>MEMS Community,
>
>I am interested in dicing up a 500 um quartz wafer into circular dice,
>roughly 10 mm diameter. I have two questions:
>
>1) What technologies and companies are available to do the cutting
>(preferably in California)?
>
>2) How do you hold the wafer and dice during cutting? If you hold the wafer
>only, then the circular parts will fall into the cutting stream/beam and
>get damaged. Is there a way to hold the individual dice? Is there a
>substrate that doesn't get cut that you can "glue" to both the wafer and
dice?
>
>Any suggestions appreciated.
>
>Thanks,
>
>John D. Evans
>Silicon Waterworks
>