Hello,
I am considering using ultrasonic bonding of Al/gold wire to platinum and
copper pads on a device and would appreciate any comments on the
following points:

1> The platinum pad (400 nm) is deposited by evaporation on Si. Since it
is a part of an RTD sensor, using a conducting adhesion layer is not
advisable. Will low adhesion of Pt to Si be a problem for the ultrasonic
wire bonding process. If so, what is the minimum thickness of the adhesion
layer that i can get away with? Which is the preferred material for the
adhesion layer?

2> The copper pads will be deposited by evaporation on PYREX 7740 and the
Al wire will be bonded to the copper pads also by ultrasonic bonding. The
pad does not have to be copper if there are other metals which are
easier/preferable for wire bonding. Any suggestions?

Thank you
Ashish

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Ashish Pattekar                      | Off.      : 610-758-4668
Integrated Microchemical Systems Lab | Res.      : 610-954-9352
Department of Chemical Engineering   | Email     : asp2@lehigh.edu
Lehigh University,                   | Whome     : www.lehigh.edu/~asp2
Bethlehem, PA 18015                  |
http://www.lehigh.edu/~inmifuel/     |
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