(中国科学院上海冶金研究所,上海 200050)
摘 要: 研究了电镀Ni层和化学镀Ni-P合金层对Sn-Ag/Cu焊点扩散行为的影响,电子探针分析表明:化学镀Ni-P合金层能很好地阻止Sn-Ag/Cu焊点在焊接过程中的Cu,Sn互扩散和相互反应;而电镀Ni层则不能阻止Sn-Ag/Cu焊点在焊接过程中的Cu,Sn互扩散和相互反应,界面反应产物仍以Cu6Sn5为主。应用化学镀Ni-P合金作为Sn-Ag/Cu之间的扩散阻挡层可大大减少Sn/Cu金属间化合物的生成,有利于提高焊点的可靠性。
关键字: 扩散;电子器件封装;镍镀层;金属间化合物
(Shanghai Institute of Metallurgy, Chinese Academy of Sciences, Shanghai 200050, P.R.China)
Abstract:The effects of electroplated Ni layer and electroless plated Ni-P layer on the diffusion behavior in Sn-Ag/Cu solder joint were studied. The results by EPMA analysis showed that the electroless plated Ni-P layer acted as a good diffusion barrier between Sn-Ag solder and Cu substrate. However, the electroplated Ni layer can not hinder the inter-diffusion and reaction between molten Sn-Ag solder and Cu substrate when reflowing, and there was a layer of IMC (Cu6Sn5) at interface of Sn-Ag/C u solder joint. Electrolessly plated Ni-P layer can obviously decrease the generation of Sn-Cu IMC at the interface of Sn-Ag/Cu, which is beneficial to improve the reliability of solder joint.
Key words: diffusion; electronic packing; nickel-plated layer; intermetallic compounds