Simulation of displacement response of capillary and feature extraction for wire bonding process monitoring

摘要

This paper investigated vibration displacement responses of capillary in ultrasonic wire bonder and feature extraction method for the bond failure monitoring and quality control during bonding process. The free and forced vibration displacement responses were simulated using finite element method to have a comprehensive understanding of vibration behaviors and their impacts on the bonding quality. Loads with different frequencies were applied to the horn to analyze the changes of the response waveforms during the bonding process. Since the bonding process is a typical transient process, in which the waveform of capillary response varies quickly, a feature extraction method based on the Hilbert-Huang transform was introduced to analyze the displacement responses. Examples were demonstrated to show the practicability and validity of the proposed method.