关键词: 运算放大器, 参数测试, 静电放电, 失效分析

Abstract: In view of the problem of unqualified test of a certain type of operational amplifier after plastic packaging and fixation in the debugging process of a certain system, the failure mechanism of a certain type of operational amplifier is explored by formulating a failure analysis plan. The electrical parameters of the failed samples are tested, and the output voltage is found to be abnormal, and the parameters such as bias current and input offset voltage are out of tolerance, and the failure mechanism is preliminarily determined to be electrostatic damage. The I-V characteristic curve testing and comparative analysis are carried out to confirm that the second input port is open to the positive power port. Through X-ray inspection and particle collision noise inspection, the possible defects and movable excess objects that may exist inside the device packaging are investigated, and the device is opened and the internal structure and layout are observed, and it is found that there are obvious breakdown marks at Pin5. With the maximum withstand voltage as the starting voltage and the step of 100 V, the electrostatic discharge test of the human body model is carried out on the qualified samples, and the failure mechanism of the operational amplifier caused by electrostatic discharge resulting in transistor breakdown and burnout is verified.

Key words: operational amplifier, parameter testing, electrostatic discharge, failure analysis