Dear Deepak

I have been simulating pull-in for the square diaphragm using Intellisuite. I
have a paper from MSM99 entitled Energy based solution method for Global
behaviour of Diaphragm under pneumatic and electrostatic pressure. This paper
discusses that pull-in can be greater than 1/3 of the gap. Please, go thorugh
the paper and in case you have trouble finding it I can send you the pdf of the
same.

I hope this helps.

Best wishes

Anurekha
Department of Electronic Science
Kurukshetra University

Quoting deepak agrawal :

> Hi all,
>           I am working on the Coventorware software. In the structure I have
> the Si3N4 membrane, which is at the 1.2µm above from the substrate. The
> membrane looks like a rectangle type structure. It has the central plate of
> 30 x 30 µm2, which is supported by the four beams of 20 x 5 µm2. The
other
> ends of the beam are fixed.
>
>           First I optimized the meshing such that I got the same results for
> two different meshing. After that I did the pull in analysis in this
> software. I am getting the deflection more the 1/2 (0.64 µm) of the
original
> gape at the pull in voltage, while it should be around 1/3 (0.4µm) of the
> original gape. I am facing this problem not only for this structure for
> other structures also. The fix-fix beam of the size of 70 x 30 µm2 , I am
> getting the deflection correspond to pull in voltage is 0.773µm.