Analysis and Optimization of Wire Bonding Parameters for Die with Thick Aluminum Pad Based on Orthogonal Experiment

The quality of the bonding directly determines the reliability and life of the circuit. The die with the top aluminum thickness of 2.5 microns is taken as the research object, and an automatic aluminum wire bonder is used to carry out the process experiment. Through the orthogonal experiment, the influence of different bonding parameters (ultrasonic power, bonding force, and bonding time) on the bondpad peeling is studied, and a suitable combination of bonding parameters is found to solve the problem. The experiment results show that for the aluminum bondpad peeling, the order of influence of the bonding parameters is ultrasonic power, bonding time and bonding force, but the bonding force and bonding time need to be increased appropriately. For aluminum-silicon wire with a diameter of 32 microns, combining the experiment results and the actual wire bonding effect, the suitable parameter range is ultrasonic power 80±5(0.29 watts~0.33 watts), bonding time 25ms~30ms, and bonding force 25g~28g. The experiment results also show that, for the influence on the strength of the wire neck, ultrasonic power plays a dominant role, and the influence of bonding force is greater than that of bonding time.