Hi Yenwen,

Stiction and the ways to prevent it are not fully understood yet. It
may happen wherever two surfaces come in contact.
As far as I know, supercritical drying is to prevent surface micro-
machined structures from being pulled down by surface tension of the
diminishing fluid and then come into contact and stick. Supercritical
CO2 has no surface tension.
In devices that rely on contact (like TI's micromirrors), you have to
apply other methods to prevent them from sticking during operation.
Hermetic packages free of contamination and any humidity are critical,
and TI employs special materials and a thin (monolayers) anti-stiction
coat on all free surfaces, applied after sealing the package. Method
and material for this are proprietary, but you may find their patent
or similar methods published by others.

Greetings,
        Frank Berauer
        Senior R&D Engineer
        Hewlett-Packard Singapore


-----Original Message-----
From: Yen-Wen Lu [mailto:ywlu@seas.ucla.edu]
Sent: Friday, December 06, 2002 1:46 PM
To: BERAUER,FRANK (HP-Singapore,ex7)
Subject: RE: [mems-talk] Anti Stiction


Hi, Frank,

Is it CO2 supercritical drying or other ways to prevent the stiction?
It sounds that you may know some methods that TI is using. Would you
mind to share them?
Thank you. Frank.
PS: I enjoy watching your comments regularily.

yenwen

On Wed, 4 Dec 2002, BERAUER,FRANK (HP-Singapore,ex7) wrote:

> There is a lot more experience in this field than you know of,
> because most of it is company confidential. TI has a neat method
> that works well in their DMD chip manufacturing, but they won't
> tell you much about it. Others publish even less.
>
> Greetings,
>       Frank Berauer
>       Senior R&D Engineer
>       Hewlett-Packard Singapore
>
>
> -----Original Message-----
> From: Jephtah Lorch [mailto:Jephtah@flixel.com]
> Sent: Tuesday, December 03, 2002 5:31 PM
> To: mems-talk@memsnet.org
> Subject: [mems-talk] Anti Stiction
>
>
> It seems that there is very little experience with industrializing
> anti-stiction processes namely: achieving repetitive and consistent
> results.
>
> I would appreciate any tips on suppliers and/or experts in this field.
>
> Thks
>
> Jephtah@flixel.com
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