I also only have experience of SU-8 but another possibility is insufficient exposure dose. Negative resists expose from the "top down" and not enough energy can lead to everything lifting off. Maybe your lamp is getting old? On Fri, Feb 12, 2010 at 16:34, Yifan Wuwrote: > Paul, > > As my experience on SU-8, thermal shock is one reason for peeling off. I > don't know about BPR100, but it might be the cause. > > Yifan