老化试验条件下的IGBT失效机理分析

Analysis of IGBT Failure Mechanism Based on Ageing Experiments

IGBT模块失效机理是变流器可靠性状态监测的基础,通过分析模块老化失效机理,得到饱和压降Uce补偿模型和结温Tj计算模型,建立IGBT模块功率循环实验平台,验证模块失效的物理过程和机理,得到IGBT模块在老化过程中电气和热参数的变化趋势,并建立热阻的退化模型,分析不同工作条件下对模块老化的影响。试验结果表明,模块在交变温度下焊接层失效是模块的主要失效方式,失效过程中其特征参数热阻满足参数退化模型,结温差越大模块越容易发生失效。通过IGBT模块的老化实验分析器件的老化机理,为变流器的状态监测和运行可靠性评估奠定一定基础,也为功率器件的可靠性设计提供决策支持。

Failure mechanism of IGBT modules is the foundation of the reliability condition of monitoring for converters. By analyzing the ageing failure mechanism of modules, the Uce compensation model and Tj computing model were obtained, and the power cycle experiment rig was established for IGBT modules. Firstly, the physical process and failure mechanism of IGBT were validated and the electrical and thermal parameters were obtained. In addition, according to the experimental data the model of thermal resistor degradation were found. Finally the effects on power modules were analyzed under different -test conditions. It is indicated that the solder fatigue is the main failure of the module during junction temperature cycling and the ageing velocity is proportional to the temperature difference. Therefore, according to the experimental data, the mechanism of ageing was discussed and analyzed which could make the foundation for the development of condition monitoring and the design of power device reliability.