We've run into a similar problem.  The only solution is to design your
own.  We've designed one that works really well but is proprietary.  One
thing I can tell you is to look into using an custom o-ring with SS
plates.  You can get the flatness if the fixture is designed correctly.

Good luck,
Selso Luanava

-----Original Message-----
From: WLODEK KAPLAN -1023 [mailto:[email protected]]
Sent: Thursday, February 04, 1999 12:25 AM
To: [email protected]
Subject: shadow masks


Hello,

We are using shadow contact masks made of Si for one of the
metalization processes. They are fabricated by cutting holes wih
laser in thin silicon wafers, so they can be very easily damaged
during the alignment procedure. The alternative substrate for mask
fabrication would be metal but the problem is the flatness of the
mask after fabrication because we need around 100 holes on 100 mm
wafer.

Does anyone have experience with shadow masks and/or know the
supplier of shadow masks made of metal?

Wlodek Kaplan

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