Hi Nirmal,

There will certainly be differences in bake times.  Glass, for example, takes
much longer to heat compared to Si wafers.  The exact time depends on the glass
size and thickness and the mass of your hot plate.  You can determine how long
it takes for the top surface to reach the required temperature by using a
surface thermocouple to directly measure it.  Bear in mind also that many
plastics, including acrylic, will soften well below the required bake
temperatures.

Another consideration is that non-round substrates will exhibit significant
coating thickness differences, especially in corners, if you are spinning on the
SU8 material.

Brad
_________________________________

Brad Cantos
brad.cantos@holage.com
http://holage.com




On 23 Nov 2010, at 9:28 AM, Nirmal punjabi wrote:

> Hello,
>
> I am working with SU-8 2100, the datasheet gives some Prebake & Postbake
> timings. Till now i was using Silicon wafer as substrate for making SU-8
> structures. I want to use some other material like glass slide or acrylic as
> substrate.
>
> Does substrate material or thickness has effect on prebake or post bake
> time?
>
> If Yes, how to change Baking time with different substrates?
>
> Thank You.