热处理工艺对锡须的形成与长大影响

Effect of Heat Treatment on the Formation and Growth of Tin Whisker

用扫描电镜观察分析、研究了不同热处理工艺对共晶Sn-Cu电镀层上锡须的形成与生长影响。结果表明,高温高湿处理易促使锡须的形成与长大,经过一定的时间后,锡须生长速度减缓;循环热处理或室温处理对锡须的形成与长大影响较小;施加恒定拉力后进行室温处理,锡须的形成完全受到抑制,其形成与长大是由于电镀层中存在压应力,促使镀层中的锡再结晶并长大成锡须。

The effect of heat treatment on the formation and growth of tin whisker from eutectic Sn-Cu electroplated coating was investigated by use of scanning electron microscopy（SEM）.It is shown that the unbiased temperature ＆ humidity accelerates the formation and growth of tin whisker.However,thermal shock or ambient temperature storage do not obviously promote the formation and growth of tin whisker.When adding tensile stress in ambient temperature storage,the formation of tin whisker is completely inhibited.The compressive stress is necessary condition leading to recrystallization and tin whisker growth.