Hi Sheela,

In my research group, we use HD Microsystems PI-2616 as a sacrificial
layer for MEMS release. We have measured the complex refractive index to
be n + i*k = 1.69 + i*0.0001 at a wavelength of 1400nm, and have
measured k to be less than 0.001 from 1.2 micrometer to 2.3 micrometer.

We partially cure our polyimide on a hotplate at 130 degrees for 15
minutes, to ensure that we can still wet release it in photoresist
developer- so for your application, the polyimide will get etched and
transfer the pattern of the photoresist.

Jason Milne
Microelectronics Research Group
The University of Western Australia

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of sheeja mathew
Sent: Tuesday, 20 March 2007 5:55 PM
To: mems-talk@memsnet.org
Subject: [mems-talk] polyimide

Hi all,
  Where to get Commercial polyimide having the following properties.
  1) Spin coated and when ppr develops, the polyimide gets etched there
by transfering the pattern from the photoresist.
  2) Transparent to light in the wave length range of 1.3 to
1.55micrometer & with low absorption characteristic.
  3)Curing temperature less than 300C.