Ni含量对SnBi36Ag0.5/Cu焊点界面化合物层形貌与厚度的影响

Influence of Ni content on morphology and thickness of interfacial compound layers in SnBi36Ag0.5/Cu solder joint

通过制备SnBi36Ag0.5Nix(x=0,0.01,0.03,0.05,0.07,0.09)/Cu焊点样品,采用加速老化的方法,将焊点样品在120℃下等温时效500,1 000,2 000 h。使用光学显微镜、扫描电镜能谱(SEM-EDS)分析Ni元素对焊点界面化合物层形貌与厚度的影响。结果表明:随着等温时效时间的延长,界面层变得均匀连续,厚度逐渐增加,在2 000 h达到峰值;界面层由Cu_(6)Sn_(5)和Cu_(3)Sn构成,与界面层相交的富Bi相会促进Cu_(6)Sn_(5)层增厚;Ni元素的最优添加量为0.01%,在该含量下,Cu_(3)Sn层的生长受到抑制,界面层的总厚度控制在较低水平。