微波电路中In/Au合金焊点的失效分析

本文针对微波电路元件焊接脱落问题,分析了In/Au合金焊点的微观结构及成分, 研究了In/Au芯片焊接的失效模式.找出了焊点脱落的主要原因:温度控制不当引起焊点的过热吃金或焊料的氧化引起的浸润不良,导致焊点的结合强度不够,致使焊点脱落.根据分析提出了严格控制温度及焊接时使用氮气保护的改进意见,较好的解决了In/Au合金焊接脱落问题,支撑了微波电路的生产工艺.

Failure Analysis of In/Au Solder Joints in Microwave Circuit

Aimed at the problem of In/Au solder joints in microwave circuit,the microstructure and components of In/Au solder joints were analyzed and the failure modes for die bonding by In/Au were documented.The failure causes were discussed and preventive measures were suggested.Non-control of temperature and oxidation of solder lead to decrement of the die shear strength:if the bonding temperature is too high,all gold would be form Au/In alloy with indium and no Gold layer left;if the solder are oxided,which is responsible for local non-wetting between gold and indium.According to the analysis we suggested that it would be better to control temperature precise and use the protective atmosphere of nitrogen,experiment results significantly favored the processing of microwave circuit.