关键词: MCU, 浪涌, 热插拔, 瞬态二极管, 失效分析

Abstract: Tested on 3100 boards, 2653 of them had problems, the defect rate reached 86.6%, the fault board could not operate normally after the machine was installed, and the phenomenon of short circuit of power supply appeared. After technical analysis of the faulty board, it was found that the MCU pin was broken down by abnormal voltage and current, resulting in short circuit of the pin to the ground and the power supply end. The customer did not make any corresponding hot-plug protection design for the pins with this problem during the application design. According to the actual application of the customer's board card, the TVS (transient voltage suppressor) is added to the pin line with problems of the board card to reduce the surge impact and make the yield of mass production reach the qualified standard.

Key words: MCU, surge, hotplug, transientvoltagesuppressor, failureanalysis