车用碳化硅功率模块的电热性能优化与评估

Electro-thermal Performance Optimization and Evaluation of Automotive SiC Power Module

由于在开关速度、温度特性和耐压能力等方面的优势,SiC(silicon carbide)功率模块开始逐步应用于电动汽车的电机控制器。电机控制器是电动汽车的核心部件,对功率模块的电热特性要求较高,因此对SiC封装提出了很大的挑战。以主流的HybridPACK Drive模块封装为例,优化设计了模块的驱动回路和DBC(direct bonded copper)布局,并引入了铜线键合技术,协同优化了模块的电热性能和可靠性。此外,采用响应面法优化了椭圆形Pin-Fin散热基板,提升了模块的散热性能。最后,分别制造了优化前、后的SiC功率模块样机作为对比,搭建了双脉冲和功率对拖实验平台,评估了2种方案的电热性能。实验结果显示,当芯片交错距离为芯片宽度的1/2时,所优化的功率模块可以在兼顾电性能的同时,实现更优异的热性能。

Owing to their advantages in switching speed,temperature characteristics and voltage withstand capability,silicon carbide(SiC)power modules are gradually applied in the motor controllers of electric vehicles.As a core component of electric vehicles,the motor controller demands high electro-thermal characteristics of power modules,posing a significant challenge to SiC packaging.In this paper,the mainstream HybridPACK Drive module packaging is taken as an example,the driver and direct bonded copper(DBC)layout are optimized,and the copper wire bonding technology is introduced to balance the module’s electro-thermal performance and reliability.In addition,the response surface methodology is used to optimize the elliptical Pin-Fin heat sink,thereby enhancing the module’s heat dissipation performance.Finally,prototypes of SiC power modules before and after optimization were fabricated for comparison,and a double-pulse test setup and a power back-to-back test setup were established respectively to evaluate the electro-thermal performance of the two approaches.Experimental results indicate that when the chip spacing was equal to half the die width,the optimized power module can achieve a superior thermal performance while maintaining the electrical characteristics.