Wire bonding dynamics monitoring by wavelet analysis

Aluminum wire bonding was performed on a lab test-bed with PZT transducer device. Vibration behavior of bonder transducer was monitored, and the correlations between bonding pressure, high frequency tool vibrations, and average bond strength were then demonstrated to determine the statistically significant differences among them. Wavelet decomposing, combined with statistics-based data processing, was utilized to explore the details of bonding process and evade inherent bonding uncertainties. Experimental results show that the method is practical and effective even if the interactions between transducer and its bonding target are very small. The obtained time-frequency plots were depicted for identifying un-modeled wire bonding dynamics.