Juntao,
Actually, since SU-8 is a negative tone material, you actually stand to improve
the uniformity by over exposure. Underexposure would have an increased chance
of adhesion loss, since the material furthest away from the exposure source (and
thus, closest to your silicon surface) will not be fully crosslinked (if at
all).
With the further processing you are performing (i.e., hot embossing), the
temperature you are processing at is probably above the glass transition
temperature (Tg) of un-crosslinked SU-8 (which is 55C), which allows the
material to reflow during the stamping process, and generally weakening the bond
to the silicon.
Best Regards,
Chad Brubaker
EV Group invent * innovate * implement
Technology - Tel: (602) 437-9492, Fax: (602)437-9435 e-mail:
[email protected], www.EVGroup.com
This message and any attachments contain confidential or privileged information,
which is intended for the named addressee(s) only. If you have received it in
error, please notify the sender immediately and then delete this e-mail. Please
note that unauthorized review, copying, disclosing, distributing or otherwise
making use of the information is strictly prohibited.
-----Original Message-----
From: [email protected] [mailto:mems-talk-
[email protected]] On Behalf Of Juntao Xu
Sent: Tuesday, February 03, 2004 12:02 PM
To: [email protected]
Subject: [mems-talk] SU-8 adhension problem
Hi,
I use SU-8 (2000 series) to make multilever mould for PDMS microfludics. I
tried both silicon and glass as the substrate. The SU-8 exposure and
development are fine, the mould looks good. But when I peeled PDMS from the
mould, most of the SU-8 structure are peeled off with PDMS, the mould can't
be reused. It seems the adhension between SU-8 and the substrate is very
poor. Anyone could give me some suggestionon how to improve the adhesion? If
I need underexpose SU-8 to improve the adhension? Thanks!
Juntao
_________________________________________________________________
Tired of spam? Get advanced junk mail protection with MSN 8.
http://join.msn.com/?page=features/junkmail
_______________________________________________
[email protected] mailing list: to unsubscribe or change your list
options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
Hosted by the MEMS Exchange, providers of MEMS processing services.
Visit us at http://www.memsnet.org/
