Hi Matt
I am Jan Newman working with the EVGroup.in the UK and
Ireland.
have a look at our website there are a lot of technical papers on SU-8
processing there.
I would suggest putting an alignment mark on the substrate prior to any
deposition then aligning both layers to that.
Alternatively we can use high mag objectives with shallow field of view
to pick out the interface between the two layers.
Regards
Jan
newman@optimim.demon.co.uk
>Hi all
>
>Iâm trying to find out if there is an easy method for seeing developed
>SU-8 through another layer of SU-8. We are trying to make devices
>requiring double depth processing and the aligning of the photomask for
>the second layer is very difficult as we are currently unable to see the
>developed SU-8 on the bottom layer. At the moment we need to
>overdevelop the bottom SU-8 layer until cracks appear at which point we
>can see the cracks through the top layer of SU-8.
>
>Any suggestions would be much appreciated.
>
>Thanks all
>
>Matt Davies
>STRC, University of Hertfordshire
>
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newman