The copper stud bump bonding process analysis based on thermal-solid coupled simulation

With electronic production tending to be large scale integration, digital, lightweight, small-lot and diversification, the traditional bumping fabrication technologies aren´t compatible with the electronic production such as the personalized, medical implants, military and new product development and so on for cost problem. And then the single chip bumping technology is introduced, among which the stud bumping technology becomes one the most important technologies due to compatible with wire bonding machine, no UBM, flexible and fine pitch fabrication advantages. However because of the narrow process window of copper stud bumping, easily Si crater and Al sputtering in bonding process, so reasonable setting process parameters is critical. In this paper, based on the explicit finite element copper stud bump shaping three dimension model, which has been verified, the design of experiment of bonding pressure, ultrasonic energy and ultrasonic amplitude are developed, and the effects of bonding pressure, ultrasonic energy and ultrasonic amplitude on stress, strain and temperature during the copper stud bump shaping are also investigated to determine the key process parameter, so it can lay the foundation for the follow-up quality control.