Dear Leow,

If you can gain access to a Dynatex International Scriber/Breaker equipped
with the "non-contact option it should do a nice job for you.  This will
allow you to subdice the chip without touching the topside.

Glenn B. Guilford
212 Whitetail Lane
Clarks Summit, PA 18411-9095
+ 570.587.0940
[email protected]