贴片电阻银离子迁移失效分析及工艺优化

Analysis and Process Optimization of Silver Ion Migration Failure of SMT Resistor

对失效的凸轮轴位置传感器进行解剖、SEM分析,确认银离子迁移导致贴片电阻阻值变大。设计实验验证了胶水在与助焊剂、酒精、水交叉融合后固化,出现湿软、拉丝现象是造成银离子迁移的主要原因。因此,在保证现有产线产能和设备利用率的情况下,制定了一种改进银离子偏移的工艺方法。

The failure camshaft position sensor was dissected and analyzed by SEM.It was confirmed that the silver ion migration led to the increase of the chip resistance.The design experiment verified that the main reason of silver ion migration was that the glue solidified after cross fusion with flux,alcohol and water,and the phenomenon of wet soft and wire drawing appeared.Therefore,under the condition of ensuring the capacity and equipment utilization of the existing production line,a process method to improve the silver ion migration is developed.