Sn-9Zn-xAg钎料在Cu基材上润湿性能及界面组织的研究

The effect of Ag addition in Sn-9Zn solder on its microstructure and wettability was investigated, and interfacial structure of solder/Cu was also examined. Results show that, when the addition of Ag is lower than 0.3%, the needle-like Zn-rich phases decrease gradually. But when the content of Ag is between 0.5% and 1%, Ag-Zn intermetallic compounds appear in the solders. When the content of Ag is 0.3%, the solder presents the best wettability. When the content of Ag reaches 0.5%-1%, the wettability decreases. Intermetallic compound formed at the Sn-Zn/Cu interface is a planar layer (Cu5Zn8). As for the Sn-Zn-0.3Ag/Cu interface, additional nodules (AgZn3) are visible beside the aforementioned planar layer. And the additional nodules grow up to a scalloped layer gradually as the content of Ag increases.