IGBT动态过电压失效的研究

绝缘栅型双极晶体管（IGBT）过电压击穿是一种常见的失效形式。由于电路中存在杂散电感，关断时会产生瞬间的高电压而引起动态雪崩击穿。通常误认为发生雪崩击穿是造成IGBT过压失效的根本原因。针对此问题，基于IGBT基本结构和PN结雪崩击穿原理，利用SilvacO软件仿真IGBT正向阻断以及关断瞬态时的电流密度分布，并从能量的角度深入分析得出过电压击穿的本质是结温过高引起的热失效，并从理论上给出了几种改进措施，为IGBT的正确使用与工艺改进提供理论参考。

Study on Dynamic Over-voltage Failure of IGBT

transistor Over-voltage failure is one of the common failure mechanisms to insulated gate bipolar （IGBT）. As distributing induction existing in the circuit and a peak voltage brought to IGBT during switching transient,causing avalanche breakdown.Mistakenly thinking of that a high inducted peak voltage is taken on, over-voltage breakdown could bring to IGBT. Aimed to this ideal, based on the structure of IGBT and principle of PN junction avalanche breakdown,use the computer simulation software of Silvaco to study the current density distribution of forward blocking and switching transient of IGBT. I found that the essence in over-voltage breakdown failure was thermal failure induced by cumulated heat inducing junction temperature rise through the view of energy,and put forward several improvement measures in theory, in order to improve the technology and proper application.