TDICCD相机成像系统片式电阻失效分析

Failure analysis for chip resistor of TDICCD camera imaging system

为了判断TDICCD相机成像系统在温度循环试验中出现的故障原因,通过故障模式影响及危害性分析,建立了故障树。经排查分析和测试,判断故障部位是地址线表面贴装片式电阻。元器件可靠性中心通过电测和DPA,对该片式电阻进行了失效分析。检查结果表明,该片式电阻是由使用过程中的异常外力造成片式电阻器端电极局部脱落,并排除了该器件存在批次性缺陷的可能。异常外力的来源是电装操作人员在返修过程中焊接时间过长,热应力导致片式电阻器端电极局部脱落。改进措施为严格控制片式电阻焊接时间小于2s。该故障定位准确,机理清楚,经试验验证,措施有效。

In order to determine the fault reason of TDI CCD camera imaging system during temperature cycle experimentation,the failure tree is established through fault mode effect and harm analysis.Through detail checking and testing,the fault is located in the region where the surface mount resistor is mounted for address.The failure analysis of this chip resistor is done in the components reliability center through electric test and DPA.Checking results show that exceptional stress causes terminal break off of the resistor during operation.The lot default probability is also precluded.The exceptional stress is derived from long time soldering during the repair by the soldering people.This thermal stress causes the terminal break off of the resistor.The fault is located correctly.The improved measure is limiting the soldering time of chip resistors strictly no more than 2s.The principle is also clear.The solution is effective after experimental validation.