SnAgCuCe/Er无铅钎料表面锡晶须的形态及特性

Morphologies and characteristics of tin whiskers on surface of SnAgCuCe/Er lead-free solder

关键词:  SnAgCu合金  稀土  锡晶须  形貌特征

Key words:  SnAgCu alloy  rare earth  tin whiskers  morphologies

摘要:

在Sn-3.8Ag-0.7Cu无铅钎料中添加1%(质量分数)的稀土铈或铒会在其内部形成尺寸较大的稀土相CeSn₃和ErSn₃.暴露于空气中的CeSn₃和ErSn₃将发生氧化,同时在其表面会出现锡晶须的快速生长现象.文中研究了稀土相CeSn₃与ErSn₃表面锡晶须的生长行为.结果表明,在CeSn₃与ErSn₃表面形成了大量的传统圆柱状锡晶须,同时,在其表面还出现了一些特殊形态的锡晶须,如带纹状的锡晶须、扭曲状的锡晶须、变截面的锡晶须、锡晶须的分枝、合并及搭接现象等。

Abstract:

Large sized CeSn₃ and ErSn₃ phases precipitated in the Sn-3.8Ag-0.7Cu1.0Ce/Er solder alloy are oxidized when they are exposed in air, and tin whiskers can rapidly grow on the surface of the oxidized CeSn₃ and ErSn₃ phase. The growth behavior of tin whiskers formed on the surface of the oxidized CeSn₃ and ErSn₃ phases was investigated.The results indicate that not only traditional cylinder-like tin whiskers but also some special ones are observed on the surface of the oxidized CeSn₃ and ErSn₃ phases, such as stripelike tin whiskers, distorted tin whiskers, tin whisekrs with variable cross sections, branch-type tin whiskers, merging-type tin whiskers and jointing-type tin whiskers and so on.