外部应力型晶须抑制方法的研究

当电子工业中完全实现无铅化时，晶须问题成为新的悬念。关于Sn晶须的成长机理和抑制方法的研究已经遍及全世界。晶须发生和成长被认为是Sn镀层上的压缩应力引起的。晶须分为内部和外部应力型。文章通过压缩负荷试验研究了外部应力型晶须的抑制方法。这种方法是Sn表面镀层和Cu上的Ni基底镀层之间介入薄Au镀层。结果发现镀Sn以后不久就形成了金属间化合物AuSn4，Au镀层有效地减轻了Sn晶须的数量，缩短了Sn晶须的长度。

Study on Restriction Method for External Stress Whisker

As the Pb-free activity has been completing in the electronic industry, Sn whisker is a new cause for concern. Many researches for the Sn whisker growth mechanium and the mitigation method have been continued worldwidely. Whisker generation and grouth are considered to be attributed to the compressive stress on Sn ;tale. Whiskers are classified into internal and external stress types. In the paper, the mitigation method for the external stress type whisker was studied through compressive load test. This method is thin Au plating between Sn surface plating and Ni underplating on Cu. As the results, the intermetallic compound AuSn was found to be formed Soonafter Sn plating and Au plating was effective to reduce the number and to shorten the length of Sn whiskes.