微量Ge对Sn-0.7Cu高温钎焊界面组织的影响

测试了Sn-0.7Cu和Sn-0.7Cu-0.012Ge钎料在不同钎焊温度下的润湿性,研究了Ge元素对老化过程中钎焊界面金属间化合物(IMC)层生长速率的影响。结果表明:2种钎料的润湿性相差不大,但添加了Ge元素的Sn-0.7Cu-0.012Ge钎料在不同钎焊温度下的漫流性得到了明显的改善,相应提高了约4.00%~5.00%;250℃和350℃钎焊温度下,Sn-0.7Cu/Cu钎焊界面IMC在150℃的老化条件下的生长速率分别为3.24×10-18m2/s和2.50×10-17m2/s,Sn-0.7Cu-0.012Ge/Cu钎焊界面IMC的生长速率分别为2.66×10-18m2/s和1.48×10-17m2/s。Ge元素在钎焊界面处富集,提高了界面IMC的致密性,阻碍了原子的扩散,在一定程度上抑制了界面IMC层的粗化与增厚。

Effect of trace Ge on interfacial IMC of Sn-0.7Cu solder under high soldering temperature

The wettability of Sn-0.7Cu and Sn-0.7Cu-0.012Ge solders were measured under different soldering temperature,and the influence of trace Ge on interfacial IMC growth rate during aging process was also investigat-ed. The results show that,Sn-0.7Cu-0.012Ge and Sn-0.7Cu solders have no obvious difference in their wettabili-ty,but the overflow property of Sn-0.7Cu-0.012Ge solder is significantly improved by about 4.00%-5.00%with the addition of Ge element. During the aging test at the temperature of 150℃,the interfacial IMC growth rate of Sn-0.7Cu/Cu at the soldering temperature of 250℃and 350℃are 3.24×10-18 m2/s and 2.50×10-17 m2/s,respec-tively,while Sn-0.7Cu-0.012Ge/Cu are 2.66×10-18 m2/s and 1.48×10-17 m2/s,respectively. The accumulation of Ge element in soldering interface can effectively improve the density of the interfacial IMC,hinder the diffusion of atoms,thus inhibit the interfacial IMC layer coarsen and thicken to a certain extent.