In my experience dealing with thick SU-8 layers I saw less cracking if I
slowed down the rate of development. Try diluting your developer.

Jennifer Pagan
Senior Process Engineer
WaveguideSolutions, Inc.
Jpagan@WaveguideSolutions.com
Phone: 704-927-0408
Fax: 704-599-3536


-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of Yoon Seung Wook
Sent: Thursday, March 13, 2003 3:00 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Question on crack during SU-8 developing

Dear Members,

I found some cracking issue during SU-8 developing process.
Crack was found at corner area. Our via is square and size is
4mmx4mm.(it is very big)
So it is very hard to control the crack or delamination.

Please share your experience on this issue.
I'm looking forward to hearing your suggestion or recommendation on
SU-8.

Thanks in advance.

------------------------------------------------------------------------
    Seung Wook (Uk) , YOON   Ph.D

  Senior Research Engineer
  MMII, MMC Lab
  Institute of Microelectronics (IME)
  A-Star, Singapore
  11Scenence Park Road,
  Science Part II, Singapore 117685
  Phone (Office) 65-6770-5442
  Fax (Office)     65-6774-5747