Sn-3.8Ag-0.7Cu-1.0Er无铅钎料中Sn晶须变截面生长现象  

CROSS SECTION CHANGING GROWTH PHENOMENON OF Sn WHISKER IN Sn-3.8Ag-0.7Cu-1.0Er LEAD-FREE SOLDER

作　　者：郝虎[1] 史耀武[1] 夏志东[1] 雷永平[1] 郭福[1] 李晓延[1] 

机构地区：[1]北京工业大学材料科学与工程学院先进材料加工技术研究所,北京100124

出　　处：《金属学报》2009年第2期199-203,共5页Acta Metallurgica Sinica

基　　金："十一五"国家科技支撑计划重点资助项目2006BAE03B02~~

摘　　要：在Sn-3.8Ag-0.7Cu无铅钎料中添加质量分数为1%的稀土Er会在其内部形成尺寸较大的稀土相ErSn_3.暴露于空气中ErSn_3将发生氧化,同时在其表面会出现Sn晶须的快速生长现象.室温时效条件下,在氧化的ErSn_3表面会生长出少量的杆状Sn晶须,Sn晶须的截面尺寸会发生连续变化;高温时效条件下,在氧化的ErSn_3表面会生长出大量的针状Sn晶须,Sn晶须的截面尺寸会发生阶梯式变化.提出了ErSn_3氧化过程中体积应变能是一个变量的模型,可以解释观察到的现象.Large sized ErSn3 particles precipitated in the Sn-3.8Ag-0.7Cu-1.0Er solder alloy are oxidized when exposed in air, and it was found that Sn whiskers can rapidly grow on the oxidized ErSn3. During aging at room temperature, a few rodlike Sn whiskers were observed and their diameter could be gradually changed. During aging at 150 ℃, a great number of needle-like Sn whiskers were observed and their diameter could be also changed step by step. A model, in which the volume strain energy is not a constant during oxidation of ErSn3, was suggested to explain the observed results.

关 键 词：无铅钎料 稀土 SN晶须 变截面 

分 类 号：TN601[电子电信—电路与系统]