Modelling of ultrasonic bonding process and parameter effect on gold wire balloons

In this study, for the interfacial mechanical properties of the gold wire ball bonding process in microelectronic packaging, a three-dimensional finite element model is constructed based on the ABAQUS platform to systematically investigate the influence mechanism of bonding pressure on the interfacial stress distribution. The dynamic contact behavior during the bonding process is simulated by establishing a multi-component coupling model of cleaver- golden wire ball-pad, adopting elastic-plastic intrinsic relationship to describe the material properties, and combining ultrasonic vibration and vertical pressure composite loading. It is found that the bonding pressure significantly changes the stress distribution pattern of the interface: the low pressure condition shows the ring-like delamination characteristics, and gradually evolves to the centralized distribution with the increase of pressure. Although the pressure increase can enhance the interfacial bonding strength, it will lead to the increase of stress concentration effect, which affects the reliability of the bonded structure.