Bobo,
     It depends upon the pretreatment of the surface before the Shipley is
applied.  As an example if I used a bake plus a later HMDS treatment about 15
minutes was the maximum.  I was etching 17,000 Angstroms of Sio2.  With a vacuum
vapor prime treatment it seemed to be limitless.  Bill Moffat.

-----Original Message-----
From: bobo [mailto:xuemengchen@mail.sim.ac.cn]
Sent: Monday, May 19, 2003 1:44 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] how long can Shipley 4620 survive in BHF


Hi, everyone,

who knows how long can Shipley 4620 survive in BHF whithout be peel off? Thanks