A contact detection algorithm of the z-axis of a wire bonder

A new design of contact detection algorithm is proposed for the z-axis of a wire bonder that interconnects between pads and leads in semiconductor manufacturing processes. The proposed test parameter for contact detection is statistically designed using the relation between Kalman filter propagations, and it has a simple process for defining probability of false alarm. Fast and stable contact detection of the z  -axis is extremely important for maintaining proper quality in the fine pitch gold wire bonding process, which has a small pad size of below 70μm. Experimental results are presented to demonstrate the advantages of the proposed algorithm.