金属间化合物的形成引发Sn-Bi晶须的生长  

Sn-Bi Whisker Growth Induced by Intermetallic Compound Formation

作　　者：何洪文[1] 徐广臣[1] 郝虎[1] 郭福[1] 

机构地区：[1]北京工业大学,北京100124

出　　处：《稀有金属材料与工程》2010年第A01期200-203,共4页Rare Metal Materials and Engineering

基　　金：教育部新世纪优秀人才支持计划资助项目

摘　　要：电流密度为3×103A/cm2和环境温度100℃的实验条件下,在Cu/共晶SnBi焊点/Cu焊点的阴极和阳极Cu基板上都发现了晶须的生长。经EDX检测可知,其成分为Sn-Bi的混合物。抛光后发现,大量的Cu6Sn5金属间化合物附着在Cu基板上。结果表明:随着通电时间的延长,SnBi钎料在电迁移的作用下发生了扩散迁移,在Cu基板上形成了薄薄的钎料层。在焦耳热和环境温度的作用下,钎料层中的Sn与Cu基板中的Cu反应生成了大量的Cu6Sn5金属间化合物。这些金属间化合物的形成导致在钎料层的内部形成了压应力。为了释放压应力,Sn-Bi钎料以晶须的形式被挤出。Whiskers were observed on both the anodic and cathodic Cu substrate with current density of 3×10^3A/cm^2 at 100℃ in Cu/eutectic SnBi/Cu solder joint. EDX compositional analyses indicate that these whiskers were composed of Sn and Bi. After polishing, plenty of Cu6Sn5 intermetallic compounds were found on the Cu substrate surface. Experimental results show that with stressing time increasing, SnBi solder started to diffuse and migrate towards the Cu substrate by electromigration force, which formed a thin film layer on the Cu substrate. With the dual effect of Joule heating and circumstance temperature, Sn reacted with Cu to form Cu6Sn5 intermetallic compounds resulting in compressive stress formation in the thin film layer. To relieve the compressive stress, Sn-Bi whiskers were extruded out.

关 键 词：品须 金属间化合物 电迁移 焦耳热 压应力 

分 类 号：TG425[金属学及工艺—焊接]