6.5kV SiC MOSFET模块加权优化设计与实验研究

Weighted Optimization Design and Experimental Study of 6.5kV SiC MOSFET Module

针对高压SiC模块的封装关键问题(即绝缘性能、寄生参数、热管理),该文提出多目标加权优化方法,实现6.5kV SiC MOSFET模块多个性能指标的折中和优化。首先,通过建立电、热、力多物理场有限元模型分别对量化指标寄生电容、焊料层热应力以及电场强度进行建模,并对三者进行加权优化,得到最优尺寸参数以保证6.5kV SiC MOSFET模块的整体性能;然后,通过对外壳和端子的设计,保证模块外部绝缘可靠的同时尽可能降低寄生电感,实现模块寄生电感和外部绝缘性能的折中;最后,通过双脉冲实验、耐压测试等验证所研制模块的性能优势及多目标加权优化方法的有效性。结果表明,所提研制模块能够在4 500V/14A的条件下可靠工作;在寄生参数、绝缘性能得到优化的同时,保证了模块整体性能的优越性。

Aiming at the key problems of high voltage Si C module packaging(i.e. insulation performance, parasitic parameters, thermal management), a multi-objective weighted optimization method was proposed in this paper to achieve the trade-off and optimization of multiple performance indexes of 6.5kV SiC MOSFET module. First, the parasitic capacitance, thermal stress of the solder layer and electric field strength were modeled respectively by establishing multi-physics finite element models. The three indexes were weighted and optimized to obtain the optimal dimensional parameters to ensure the overall performance of the 6.5k V Si C MOSFET module. Through the design of the housing and terminals, the parasitic inductance was reduced as much as possible while keeping the external insulation of the module reliable. The parasitic inductance and insulation performance of the module were compromised. Finally, the performance advantages of the developed module and the effectiveness of the multi-objective weighted optimization method were verified through the double pulse test and high potential test. The results show that the developed module can work reliably under the condition of 4 500V/14A. The superiority of the overall performance of the module is guaranteed,while the parasitic parameters and the insulation performance are optimized.