Ni-Sn-Ni焊点界面金属间化合物的微观形貌演变研究

Microscopic Morphological Evolution of Intermetallic Compounds at Ni-Sn-Ni Solder Joint Interface

【目的】研究Ni-Sn-Ni微焊点在固液反应条件下界面金属间化合物(Intermetallic Compounds,IMCs)的生长及形貌变化。【方法】采用精密夹具调控的Ni-Sn(20μm)-Ni作为样品,通过SEM观察等温条件下Ni-Sn-Ni不同时间点横截面的微观组织结构,并通过EDX对界面处生成的IMCs进行分析。【结果】在Ni-Sn反应的界面处仅生成一种单相IMCs,为Ni_3Sn_4,该界面IMCs的生长速度由快变慢最后趋于平缓。此外,界面IMCs的形貌随时间由针状转变为棒状后再转变为块状。【结论】在Ni-Sn固液反应中,界面IMCs的生长速度及形貌随键合时间的增加发生显著变化。

[Purposes]In this paper,the growth and morphology changes of interfacial intermetallic com-pounds(IMCs)in Ni-Sn-Ni micro-solder joints under solid-liquid reaction conditions were studied.[Methods]In this experiment,Ni-Sn(20μm)-Ni regulated by precision fixtures were used as the sample,the microstructure of the cross-section of Ni-Sn-Ni at different time points under isothermal conditions was observed by SEM,and the IMCs generated at the interface were analyzed by EDX.[Find-ings]Only a single-phase IMCs Ni3Sn4 was formed at the interface of Ni-Sn reaction,and the growth rate of IMCs at the interface changed from fast to slow and finally flattened.In addition,the morphology of interfacial IMCs changes from needle-like to rod-like and then to bulk-like with time.[Conclusions]During the Ni-Sn solid-liquid reaction,the growth rate and morphology of interfacial IMCs changed sig-nificantly with the increase in bonding time.