In my experience SU-8 2000 series can develop really large edge beads,
especially on small substrates.  I imagine that only spinning at 800 rpm
can't help much either.

-Alex

On Wed, Dec 1, 2010 at 12:30 PM, Nirmal punjabi wrote:

> Hi,
>
> I need a thickness of around 400um of SU-8, i am spin coating SU-8 2100 at
> 800rpm for 60 sec.
>
> But the final structure formed has uneven surface.
>
> Can anyone help me on this matter?
>
> Thank you.
>
> Nirmal.