Ditto to Brian. I always use spin-coated PDMS membranes to seal the Si
mold for my molding. You can spin coat PDMS either onto Si or Glass.
But I found it is easier to release with Glass substrates. Typically,
I spin coat at 600 rpm in 40-50s to achieve PDMS thickness of 150-160
um. A curing on a hotplate at 100C in 15 min would be enough to harden
the PDMS membrane. I can even release thinner PDMS membrane without a
problem.

Greetings,
Nam Le, Ritsumeikan University


On Fri, Aug 22, 2008 at 3:51 AM, Brian Stahl  wrote:
> If you want PDMS thinner than 300µm, you could always spin it onto a wafer
> and adjust your spin speed to achieve your desired thickness.
>
> Regards,
> Brian Stahl