Hello Shramik,

Using GE RTV615 (1:10 v/v), I achieved thicknesses ranging from about
33um-7um with spins of 3000rpm-8000rpm on a blank 4" wafer. Thinner layers
might be possible with solvents, but that yielded poor results in my
experience.

Andrew Fung

-----Original Message-----
From: Shramik Sengupta
Subject: [mems-talk] spinning on thin layer of PDMS


I have a question with regard to spinnning on thin (~10 micron) layer of
PDMS.

I have previously spun on layers ~100 micron thick. But I recall that even
that required fairly high RPMs on a standard spin coater. I also came across
some article that mentioned that using 8000 RPM to obtain 40 micron thick
layers.

I wonder if any of you have been able to spin on the thicknesses that I am
looking for (~ 10 micron). Does making modifications like using high
temperatures and/or certain solvents help ?

Also, since we are looking to create (what essentially boils down to) a very
thin shim around an area of interest, we are also open to using other
materials - provided they can be bonded to another similar surface. I'd
welcome any suggestion on this point, too.