A design of touch detection algorithm for bonding tip of wire bonder machine

This paper describes a design of touch detection algorithm of bonding tip in gold wire bonding process. It contains a new design of a detection algorithm for capillary contact on pad and lead in the wire bonding process of interconnection between pads and leads. The design method is developed by a systematic approach from the viewpoint of handling the risk of false detection based on not trial and error but on statistical analysis. The paper shows a systematic approach to the design of a velocity estimator and touch detection algorithm for a bonding tip by introducing the concept of the optimal estimator. The statistical approach provides more convenient and powerful tools for managing the risk of false contact detection or velocity estimate, which leads to more stable detection time and finally more stable bonding quality. Real wire bonding experimental results are presented to demonstrate the advantages of the proposed algorithm.