雷达微波功率管引脚失效仿真分析与优化

摘要

针对微波功率管在温度循环试验中出现的引脚脱落故障，通过力学仿真进行故障复现和失效机理分析，确定了功率管底座与盒体材料的热膨胀系数不匹配，以及连接方式不合理是造成引脚失效的主要原因。在不改变器件材料的前提下，提出了将功率管与盒体的连接方式从焊接改为螺钉连接的优化设计方案。通过仿真和试验验证，证明了该优化方案能有效解决引脚失效问题。%In this paper,mechanical simulation was applied to fault recurrence and failure mechanism analysis for pins’failure of a radar microwave power transistor in the temperature cycling test.It indicated that the major cause was the inappropriate connection type between foundation of the power transistor and cavity of the power amplifier,so that there was not enough cushion space to release thermal deformation and stress resulted from very different coefficient of thermal expansion.Under the premise of not changing the device materials,an improvement to the connection type was proposed by changing welding to screw fastening.The results of simulation and experiments showed that the solution was effective.