超低银SAC钎料焊点界面显微组织演化

Microstructures evolution of low silver SnAgCu solder joint

摘要: 研究了复合添加Ga/Nd元素的超低银Sn-0.3Ag-0.7Cu钎料在长期时效过程中的微焊点界面组织演化情况. 结果表明，复合添加适量Ga/Nd元素可以显著改善时效后微焊点界面组织，抑制微焊点界面附近大块状金属间化合物以及稀土相的生成. 经720 h时效后，即使在含有过量Nd元素的微焊点界面仍没有发现明显的Ag₃Sn相和稀土相，取而代之的是小块状的新相，结合EDS和XRD分析结果推测该相含有Ga₂Nd与Cu₆Sn₅. 经过长期时效处理后，微焊点抗剪力接近Sn-3.8Ag-0.7Cu焊点抗剪力的90%，具有较好的力学性能.

Abstract: The effect of Ga/Nd multi-addition on microstructure of Sn–0.3Ag–0.7Cu solder in the course of aging treatment was investigated. The results indicated that the multi-addition of Ga/Nd could significantly refine the interfacial microstructure of solder joint and inhibit the formation of intermetallic compounds after aging treatment. After aging treatment over 720 h, no evident rare earth phase Ag₃Sn was found in Sn–0.3Ag–0.7Cu–0.5Ga–1Nd solder joints, instead, new phase was formed near the interface of solder joint And the results of EDS and XRD indicated that the new phase should contain Ga₂Nd and Cu₆Sn₅. The shear force of Sn–0.3Ag–0.7Cu solder joint after aging treatment reached 90% of Sn–3.8Ag–0.7Cu solder joint.