Hi everyone,

I got 2mm diameter holes drilled in a pyrex glass
plate (which is 1mm thick), by sending a jet of alumina
powder. After that, to make the glass stress-free, I
annealed it at 570 C for 48 hours. But any subsequent
processing (e.g. heating it to about 490 C and application
of 700 volts) cracks the glass.

Can anyone suggest a better method for removing stress
from the glass piece?
Thanking all in advance,

Debjani Pal

Research Scholar (Semiconductor Group)
Department of Physics                 Ph: (080)309-2316
Indian Institute of Science           Fax:(080)334-1683
Bangalore - 560012