[mems-talk] Bonding gold wires to gold electrode

[Michael D Martin]

Hi Jeffrey, 
   You are quite likely to have problems.  In the past we have tried to wire bond to platinum pads (200nm thick) atop 6 um polyimide. It was not possible to produce reliable wirebonds until the polyimide thickness was reducded to 3 um.  One significant source of problems was delamination of the metal layer due to the ultrasonic energy.  We got around this by lowering the energy to 2.0-2.5 on a ball bonder (max of 10).  I think SU-8 is a bit harder than polyimide so maybe you will have fewer problems. 

-Michael 
 U. of Louisville 

>>> "Yue Mun Pun, Jeffrey" <g0500396 at nus.edu.sg> 5/11/2007 9:30 AM >>>
Hi,
I need to bond gold wires to gold electrode.  Typically, how thick should the gold electrode be and what should the surface area of the electrode be for a good bond?  
Also, will there be any impact if the gold electrode is sitting on a film of SU-8, for if ultrasound is used in the bonding process, I'm afraid that the underlying SU-8 might crack due to the high energy of the ultrasound.