Structural design and optimization of rectifier module based on copper-clip bonding technology

The traditional wire bond packaging technology has the problems of uneven distribution of temperature and stress and large parasitic inductance, which is easy to cause failure modes such as bond point breakage and falling off, which seriously affects the reliability of the rectifier module and restricts the electrical properties of the rectifier module. Compared with the traditional wire bonding technology, copper clip bonding has higher current transmission capacity and heat conduction capacity, lower on-resistance and parasitic inductance, moreover its process is simple, the comprehensive cost is relatively low. Based on cooper-clip bonding technology, this paper uses copper sheets instead of bond wires to achieve electrical interconnection and conducts structural design and optimization analysis of the 100V/400A rectifier module. The highest temperature and stress of the chip are selected as the key evaluation indicators, and the difference between the copper-clip package structure and the traditional wire bonding structure is compared using the electric-thermal-mechanical multi-physics coupling simulation analysis. The simulation results show that the maximum temperature and maximum stress of the chip using copper-clip bonding technology and the overall parasitic inductance of the module is 3%, 40.3% and 1.4% respectively, lower than that of the wire bonding rectifier module. Finally, the effects of different width of the copper sheet, the thickness of the copper sheet, the thickness of copper sheet soldering layer and the soldering area ratio of copper sheet on chip maximum temperature, stress and parasitic inductance value were obtained by simulation, and some suggestion of the design of copper-clip rectifier module was given.