I hope this would help you.

SU-8 is composed of three components; an EPON epoxy resin, an organic
solvent, and a photoinitiator [1].  The chemical formula of EPON resin SU-8
is a multifunctional glycidyl ether derivative of bisphenol-A novolac used
to provide high-resolution patterning for semiconductor devices.  The second
one is  gamma-butyrolactone (GBL), an organic solvent.  The quantity of the
solvent determines the viscosity of the solvent, which determines final
thickness of the spin-coated film.  Along with GBL, cyclopentanone is also
used as a solvent for later products of SU-8 (SU-8 2000 series).  And the
third one is triarylium-sulfonium salts (CYRACURE® UVI from Union Carbide),
a photoinitiator which is approximately 10 wt % of EPON SU-8.  Epoxy resins
could be cationically polymerized by utilizing a photoinitiator which
generates strong acid upon exposure to ultraviolet light (365 to 436 nm) and
the acid facilitates polymeric cross-linking during post-exposure bake.


[1] J. M. Shaw, J. D. Galore, N. C. La Bionic, W. E. Coney, S. J. Holmes,
"Negative photoresists for optical lithography," IBM Journal of Research &
Development, vol. 41 No. ½-Optical lithography, 1997.


Best regards.

Daniel Sang-Won Park
Graduate Research Assistant
UTD MiNDS (http://www.utdallas.edu/~jblee/research/index.html) Lab
[Cell] 214-952-8649, [Fax] 972-883-6839
[E-mail] spark@utdallas.edu
[Web] http://www.utdallas.edu/~spark



----- Original Message -----
From: "Jung-Sik KIM" 
To: 
Sent: Wednesday, June 23, 2004 2:13 PM
Subject: [mems-talk] SU-8 chemical composition


> Dear MEMS COMMUNITY,
>
> This is Jungsik Kim in the University of Birmingham.
>
> I have been used GTA(Thermogravimetric analysis) for SU-8 under Nitrogen
> atmosphere and ambient air conditions.
> Under N-gas, nearly 20% mass of SU-8(mostly Carbon) remained, but under
> air with Oxygen, almost all of them were burned out.
>
> Therefore, I'm searching for help.
> Has anyone knows chemical composition of SU-8?
>
> If yes, please let me know that.
>
> Best wishes,
>
> Jungsik Kim
>
> =========================================
> Mr. Jung-Sik, Kim
> School of Manufacturing and Mechanical Engineering
> The University of Birmingham
> Edgbaston, Birmingham B15 2TT
> Tel:  44 (0)121 414 4245
> Fax: 44 (0)121 414 3958
> =========================================
>
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