Paul,

I believe that the topic of black wax has come up before. You might
check this discussion group's archives. I think someone has provided an
address for a supplier.

Regards,
Mike Mattes
Medtronic, Inc.

>>> Mario Robles  01/03/00 12:45PM >>>
Hello Paul,

Just to clarify, are you etching the individual die or the whole wafer?
 I am not familiar with KOH etch but I believe you may be able to use a
special tape to protect the front side of the wafer or maybe even the
die during the etch process.  It is normally used during the backgrind
process, but it may work for your etch process.  I would think the tape
would be much easier to use than wax.

Mario Robles
650-966-8001 phone
650-966-1881 fax
www.dicingblades.com



-----Original Message-----
From:   BostonMicro@aol.com [SMTP:BostonMicro@aol.com]
Sent:   Friday, December 03, 1999 6:10 AM
To:     MEMS@ISI.EDU
Subject:        Black Wax


I was wondering if anyone new a vendor of Black Wax. I need to KOH etch
the
back side a chip, but don't want to destroy my devices on the front.

Thanks in advance,

Paul Bierden

President
BMC
Boston Micromachines Corporation