Once upon a time (in undergrad), we had to make some SU-8 molds for PDMS
molding but our exposure tool was refusing to load wafers.  So we
spin-coated the SU-8 onto the wafers, pre-baked them normally, taped our
transparency masks on top of the wafers, enclosed them in petri dishes and
took them outside to expose in the sunlight.  Resolution wasn't great
because of the lack of hard contact and all the ambient light, but it worked
surprisingly well.

--
Brian C. Stahl
Graduate Student Researcher
UCSB Materials Research Laboratory
brian.stahl@gmail.com / bstahl@mrl.ucsb.edu
Cell: (805) 748-5839
Office: MRL 3117A


On Fri, Oct 23, 2009 at 8:12 AM, Bill Moffat
wrote:

> Photo resist is sensitive to U.V. light.  There is about 2% U.V. in
> normal white light which makes resist sensitive to white light.  If you
> use normal precautions you can expose resist with white light just
> expect a long exposure time.  Bill Moffat