关键词: IPM模块, 焊接工艺, 金线键合

Abstract: The welding quality and gold wire bonding quality have a direct impact on the performance of IPM modules during the preparation process. In this paper, the influence of welding process parameters on the quality of vacuum reflow soldering of Pb_92.5Sn₅Ag_2.5 and the effect of bonding process parameters on the bonding performance of gold wires are studied. An IPM module is prepared after the welding and gold wire bonding processes are optimized, then, this module is subjected to dual pulse testing. The research results show that the welding parameters such as activation temperature and time, reflow zone heating time, reflow temperature and time, and cooling rate have a regular impact on welding quality. The average porosity of the weld layer is about 3.8% and the average shear strength is 32.15Mpa under the optimized welding process (activation temperature and time of 280 ℃/30 s, reflow zone heating time of 40 s, reflow temperature and time of 350 ℃/40 s, cooling rate of 4 ℃/s), demonstrating good welding quality. Under the optimized gold wire bonding process (ultrasonic power of 80 mA, bonding pressure of 50 gf, bonding time of 20 ms, bonding temperature of 80 ℃), the average size and thickness of the bonding balls are 85.2 µm and 19.1 µm, respectively, the average shear strength is 42.5 gf and the average tensile strength of the gold wires is 21.4 gf, and the bonding points have a full crescent shape, indicating good bonding quality. Furthermore, it is once again proven that the IPM module prepared based on the optimized process described above has good performance after double pulse testing.

Key words: IPM module, welding, gold wire bonding