高温功率循环下绝缘栅双极型晶体管失效特征及机理分析  

Failure Characteristics and Mechanism Analysis of IGBT Modules under High-Temperature Power Cycling

作　　者：陈明 

机构地区：[1]海军驻广州四二七厂军事代表室,广州510715

出　　处：《西安交通大学学报》2014年第4期119-126,共8页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金重点资助项目(50737004)

摘　　要：结合绝缘栅双极型晶体管(IGBT)模块结构和工作的不同阶段,分析了IGBT失效类型及其失效机理。深入分析了影响IGBT工作寿命的3种封装失效类型及失效机理。高结温、大温度梯度极端工作方式下主要的封装失效类型是键合引线失效,由某一根或几根过载引起电流分配不均引发,失效前压降大,热阻基本不变。通过分析得到IGBT模块的寿命值近似服从Weibull分布。实验过程中结合各类显微镜和红外热像仪得出的失效特征分布规律表明:经过功率循环后的芯片表面中心区域、边缘绝缘保护环原胞结构均由规则点阵变化为点阵中出现小的黑圈、空穴、裂纹,变得不再规则;各物理层接触面间的缺陷由芯片向下呈递减趋势;IGBT模块各物理层不平整度由基板向上呈递减趋势。通过实际实验发现,可将压降的突变位置作为IGBT可靠性评估的标准。Failure types and mechanism of IGBT modules according to the module structure and different operation stages are analyzed, and three types of package failure mechanism affecting the lifetime of IGBT are discussed. The package failure types and modes are concerned with the lift- off and meltdown of bonded-wires, solder fatigue, and reconstruction of metallization. The failures of bonded-wires are generally caused by a great change in junction temperature and high temperature gradient. The detection and inspection of the failure process of bonded-wires, the structure of chip surface, and the delamination and cracks and voids in solder layers by means of the instruments demonstrate that the main failure mode of high junction temperature and temperature gradient is the lift-off and meltdown of bonded-wires. The overload of one or more bonded-wires leads to an unbalanced distribution of the current. When VcE gradually becomes big, then a sharp jump happens before failure, the junction-case thermal resistance remains steady, and the value of IGBT lifetime is approximate to that of Weibull distribution. By investigating various microscopes and infrared thermal imaging, the failure characteristics are obtained. Failure characteristic distribution show that after power cycle, the central area of the chip surface, insulating protective ring of the original cell structure become no longer symmetrywith small black circles, downwardly. From basep a decreasing trend. The evaluation standard. holes, and cracks. The defects of the contact late to chip surface, IGBT module flatness of th sharp jump position of VcE can be considered physical layer decrease e physical layer exhibits as the IGBT reliability

关 键 词：绝缘栅双极型晶体管 功率循环 失效 键合引线 焊料层 

分 类 号：TN32[电子电信—物理电子学]