In this paper they observed SU-8 swelling during development:
http://www.springerlink.com/content/96nbm7g2e5pplyb7/
They indicated they were going to study it further so it may be worth
looking at subsequent papers from their group.


On Thu, Dec 16, 2010 at 01:23, Tsoll Doiiu  wrote:

> Hello everybody!
>
> Please, help me to solve the question.
>
> I need to make two PDMS covers - top and bottom,
> like this: ___----___ and ---__---, with the same length and width (heigth
> does not matter).
>
> For this I've tried to make THB and SU8 molds, using same size opposite
> masks .
> But after preparing PDMS I've figure out that real dimensions are totally
> different (bigger for "top" and smaller for "bottom"), means that during
> UV/Developing actual size of masked PR is decreasing.
>
> I want PDMS like this: ___----___ and ----__----, but I;ve got  _--------_
> and -----_-----.
>
> Could somebody advise me a formula, how to calculate real change of size
>  in mask/UV/developing steps?
>
> Or provide the solution of preparing equal opposite patterns?