Hi everyone,

I would like to create 20-30 um thick SU8 features with sufficient
mechanical integrity to allow me to release them from the substrate (through
manual peeling) without destroying them in the process. I have managed to do
this in the past, however, recently the films seem to disintegrate (i.e.
crack into into flakes) when I try to peel them off.

I used a different composition of SU8 in the past and was just wondering if
the change from SU8 50 to SU8 2050 may have something to do with the
problem. Another possibility is that the flaking is due to over/under
exposure. I am not sure whether over or under exposure would lead to the
flaking that I am experiencing - has anyone experienced this problem before?
As there were no white residues present during development, I assumed
exposure was sufficient. Could extreme over exposure imporve the film's
properties by maximising the number of crosslinks, or is there a limit
beyond which too much crosslinking degrades the film's mechanial integrity?

Any information would be greatly appreciated.

Regards,

Michael

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