Mechanism Analysis of Process Parameters Effects on Bondability in Ultrasonic Ball Bonding

Optimization of ultrasonic bonding process is a time consuming work and still remains a great technological challenge in microelectronic packaging industry due to poor understanding of the mechanism of process parameters effects. In this work, ultrasonic gold ball bonding on aluminum pad was carried out to study the effect of process parameters including bonding power and bonding force on bondability and bond pattern. The evolution of bond pattern and slip area was attributed to the variation of bondability. It is shown that the effects of process parameters on bondability can be explained by the mechanism proposed in this study.