Fritz and Mike,
     I did a significant amount of work on a polyimide curing
process about 3 years ago.  We were using a polyimide from
HDMicrosystems.  We tried curing in tube furnaces and box
furncaces while purging with very little success.  The
partial pressure of oxygen in the systems was still too
high.  We finally built a hot plate that mounts inside a
vacuum chamber.  We would cure up to 300C in room air and
then set a bell jar down over the sample and hot plate and
pull vacuum to 100 mTorr.  We would then leave a N2 purge on
that would leave the chamber pressure ~ 1 Torr, with the pump
on.  The programmable hot plate would continue up to 450 C in
the N2 ambient.  We machined the hot plate from aluminum and
bought a heating element from Omega.  We ran all of our
wiring through feed throughs and used a solid state relay and
a programmable controller to operate the hot plate.  The
chamber only had one mechanical pump on it.  The system was
rather simple but gave us great results.  The films did not
turn dark red like they did when they were cured in air and
the electrical properties were much better.  We could acheive
~ 400 V/um of breakdown strength.  Hopefully some of this
information can help you.

---- Original message ----
>Date: Fri, 16 Jul 2004 15:27:53 -0400
>From: "Michael D Martin" 
>Subject: Re: [mems-talk] Polyimide Curing Tool
>To: 
>
>Hi Fritz,
>  We use a two "tool" process 50 deg C - 200 deg C on a
hotplate, then
>into a tube furnace purged with nitrogen from 200-350 deg C.
>
>-Mike
>
>
>>>> kub@nrl.navy.mil 7/16/2004 12:59:48 PM >>>
>We are in the process of purchasing a tool for for
controlled
>3-temperature step nitrogen-ambient curing of polyimide
films?  Could
>someone describe the preferred tool either homemade or
commercial?
>
>Fritz Kub
>Naval Research Laboratory
>--

Nels Ostrom
ostrom@uiuc.edu
Graduate Research Assistant
Optical Physics and Engineering
Dept. of Electrical and Computer Engineering