[labnetwork] Strasbaugh 7AA Grinder failure advice

[Sarice Jones]

Dear Lab Network, particularly members who've had to coax 80s tools back to
life,

At the University of Washington's WNF, we have a Strasbaugh 7AA grinder via
Axus that is failing. The wafer thickness measurement, which gates
initializing and processing, has been corrupted (we believe somewhere in
the G&L board cage, the signal is accurate up to there) and the tool can't
proceed.

Specifics on the behavior we're seeing:
- 0 measurement brings back 6560 microns
- thickness measurements are nonlinearly subtracted rather than added to
this: e.g. expected measurement of 600 brings back 5460
- bottoms out at about 2640

Getting replacement boards is going slowly and we're interested in a
workaround that's preferably a step above manual mode. Is anyone familiar
with the Strasbaugh 7AA or similar tools who has advice? Some of our ideas
include:
- Reset EPROM board/chips
- Force the tool to accept an initialization sequence (wafer thickness can
be backfilled as long as the initialization is accepted)
- Get into the ladder logic of the tool

Any advice or experience is much appreciated. Regards,

Sarice
-- 


Sarice B. Jones

Facilities Engineer, Washington Nanofabrication Facility (WNF)

University of Washington, Fluke Hall 115

(206) 685-7757
sbjones at uw.edu
http://www.wnf.washington.edu/
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