Dear friends

I am trying to use SU-8 with the thickness around 30um. But during the
development in PGMEA, I found cracks created in the SU-8 . Mostly these
cracks are originated from the corner of developed region and extend long
into the SU-8.

I am wondering if someone can give me a comment why these cracks generated
and how to optimize the process.

Thank you very much

Zhiyan