Sn-Zn-Cu/Cu界面反应及剪切强度

为探讨Cu的加入对Sn-Zn钎料性能的影响,研究了Sn-Zn-xCu与Cu箔钎焊界面处金属间化合物(IM C)成分、形貌及剪切强度.试验结果表明,含0~1%Cu时,Sn-Zn-xCu钎料与Cu母材钎焊界面处IM C主要为层状Cu5Zn8相;在含2%~6%Cu时,为Cu6Sn5相和Cu5Zn8相共同组成;在含8%Cu时,为Cu6Sn5相.这是由于合金基体中生成的Cu-Zn化合物阻碍了Zn向Cu界面处扩散,进而使得界面处IM C由层状Cu5Zn8逐渐向扇贝状Cu6Sn5转变.另外,随着Sn-Zn钎料中Cu含量的增加,Sn-Zn-xCu/Cu接头剪切强度因界面IM C类型的变化以及钎料合金自身强度的提高而使得钎焊接头剪切强度明显提高.

Interfacial reaction and shear strength of Sn-Zn-Cu/Cu joints

In order to study the effects of Cu on the property of the Sn-Zn solder,the compositions,morphologies of the intermetallic compounds(IMC) of the Sn-Zn-xCu/Cu joints and their shear strength were investigated.The results indicate that the IMC of Sn-Zn-xCu/Cu joint is mainly Cu_5Zn_8 when the content of Cu is 0-1%;when the content of Cu is 2%-6%,the IMC is Cu_6Sn_5 and Cu_5Zn_8 together;when the content of Cu is 8%,the IMC is Cu_6Sn_5.With the addition of Cu,the Cu-Zn compound formed in the solder matrix prevents Zn atoms diffusing to Cu foil,which lets the planar Cu_5Zn_8 IMC at the interface change into scallop Cu_6Sn_5 IMC.With the increasing of Cu in the Sn-Zn-xCu solder,the shear strength of the Sn-Zn-xCu/Cu solder joint is enhanced obviously because of the transformation of IMC type at the interface and the improving of solder strength.