军用DC/DC电源模块失效分析研究  

Failure Analysis Study of Military DC/DC Power Module

作　　者：李鹏 张竹风 王自成 刘红 赵国发 LI Peng;ZHANG Zhufeng;WANG Zicheng;LIU Hong;ZHAO Guofa(Xi’an Modern Control Technology Research Institute,Xi’an 710065,China)

机构地区：[1]西安现代控制技术研究所,西安710065

出　　处：《电子与封装》2025年第4期31-38,共8页Electronics & Packaging

摘　　要：针对某武器系统研制过程中出现的2只DC/DC电源模块输出异常问题,通过制定失效分析方案探究其失效机理。对失效模块进行外观检查,各管脚均存在不同程度的绝缘子破裂现象;进行电性能和I-V特性曲线测试,并与合格样品进行对比,发现2只失效模块的Pin3与Pin5之间分别存在二极管特性异常和连接性异常现象,初步确定失效部位;通过X射线检测设备对模块内部基板和引线架进行检查,发现1#模块的2处VDMOS键合丝断裂,断面呈熔球状;进一步将模块物理开封进行内部检查,观察到1#模块的VDMOS芯片中间部位存在高温引起的变色现象,2#模块的管脚焊接点存在明显裂缝。对失效原因进行排查和分析,结果表明,电源端过电应力导致1#模块的VDMOS烧毁,焊接不良造成2#模块的输出异常。Aiming at the abnormal output problem of two DC/DC power modules in the process of developing a weapon system,the failure mechanism is studied through the formulation of a failure analysis scheme.Visual inspection of the failed modules shows varying degrees of insulator breakage in each pin.Electrical performance and I-V characteristic curves are tested and compared with the qualified samples,and it is found that there are abnormal diode characteristics and connectivity between Pin3 and Pin5 of the two failed modules respectively,and the failure sites are preliminarily determined.The internal substrates and lead frames of the modules are examined by X-ray testing equipment,and it is found that the bonding wires of two VDMOS chips in module 1 are broken,and the cross section is like a melting ball.The modules are further physically opened for internal inspection,and the discoloration caused by high temperature in the middle of VDMOS chips in module 1 and the obvious cracks in the weld point of the pins in module 2 are observed.The causes of failure are investigated and analyzed,and the results show that the overstress at the power supply terminal causes the VDMOS burnout of module 1 and the bad welding causes the output abnormality of module 2.

关 键 词：DC/DC电源模块 失效分析 VDMOS烧毁 焊接不良 

分 类 号：TN386.1[电子电信—物理电子学]