I have an equation for SU-8 thinning.
You have SU-8 2025, so the thinner may be the cyclopentanone.

the equation is:
(Starting Solids Content/Required Solids Content) * Volume of sample to be
diluted = Final diluted volume
Therefore Final Diluted Volume - Volume of sample to be diluted = Addition
of solvent

example
SU-8 2002 (Thickness 2um at 3000 rpm) Solid contents 29%
Target SU-8 2001 (Thickness 1um at 3000 rpm) Solid contents 22%

Formulation
(29/22) X 100 = 131.81
131.81-100 = 31.81 ml is the additional of CP

So, you have to find out the solid content of SU-8 2025. And the target
contet can be 29% of SU-8 2002.

I also want to dilute the SU-8, but I don't know the solid content of SU-8
2035 which I have.

I hope this helps,

Lee, Duhyun

========================================
duhyun@skku.edu
Technology Innovation Center(TIC)
Dep. of Advanced Materials Eng.
Sungkyunkwan University, KOREA
Tel +82-31-290-5645
Fax +82-31-290-5644
========================================
----- Original Message -----
From: "Yeswanth Rao" 
To: 
Sent: Friday, June 25, 2004 1:00 AM
Subject: [mems-talk] SU 8 Photoresist


> Dear All,
>
>
>
> I would like to use SU 8 photoresist to get a uniform coating of 1.7
> micron on Si and Si/Cr. I have SU-8 2025 photoresist and SU 8 thinner.
> Would it be possible to use this thinner to reduce the viscosity of the
> 2025 resist to get down to 1.7 micron thickness? If that is possible,
> would anyone be able to able to guide me as to what should be ratio of
> this mixture to achieve this thickness. Thanks in advance
>
>
>
> Yeswanth L Rao
>
> Graduate Research Assistant
>
> Micro/Nano Fabrication Laboratory
>
> Driftmier Engineering Center
>
> University of Georgia
>
> Athens, GA 30602
>
>
>