durusmail: mems-talk: very thick layer of SU-8
very thick layer of SU-8
2008-11-26
2008-11-26
2008-11-26
2008-11-27
2008-11-27
2008-12-01
very thick layer of SU-8
Michael Riss
2008-11-27
Hi,

there is also resist casting. You pour a defined amount of SU-8
on top of the substrate so that the whole surface is covered and
*without spinning* you let the solvent evaporate.
That way you can get quite thick layers.

You have to check the viscosity table in the data sheet for
the relation between solids and solvent in the different types of
SU-8 resists. Then you have to calculate how much SU-8 resist you
have to use in order to get the right thickness after the solvent
has evaporated. You can use e.g. a syringe for measuring the SU-8.

There is a catch however: The hotplate has to be *very level* to get
a uniform thickness. That was the point that failed in my case. :-\

And you will need a lot of time for the softbaking - I would calculate
with at least one night. Also I would give it several hours at 65 deg.
before ramping up the temperature to 95 deg, else the surface might
become bumpy.

Good luck!

cu
Michi

A. AhmadShukri wrote:
> Hi all--
>
> I am wondering if anyone knows how I can deposit a 2mm (yes, 2,00um) layer
> of SU-8 and pattern it.
>


--
Michael Riss
Parc Científic de B., Ed. Helix, IBEC
Universitat Politècnica de Catalunya
C/ Baldiri Reixac 15-21
08028 Barcelona, Spain

EMail: mriss@pcb.ub.es
Tel. +34 93 40 20 213
Fax. +34 93 40 20 183

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