The interfacial reaction of Cu/rnultilayer Sn -Cu -Sn / Cu joint in soldering

In this paper, multilayer interfacial linear solder joints were prepared by dip soldering. The effects of soldering temperature, soldering time, soldering distance and soldering layer number on IMC growth of Cu / multilayer Sn-Cu-Sn / Cu solder joints were studied. The linear solder joint of multilayer interface was obtained by dip soldering at 250°C for 30s. And then reflowing at 250°C, 300°C, 320°C for 30s, 60s, 120s, 5min, 10min, 30min. EPMA results show that there are Cu
3
Sn and Cu
6
Sn
5
phases at the interface of each layer between solder and Cu substrates. At the same time, both reflow temperature and reflow time have effect on the interfacial compound, and the size of the interfacial compound increases with the increase of reflow temperature; With the increase of reflow time, the size of interfacial compound also increases; While decreases with the increase of dip soldering distance, the IMC of the sample with larger distance is thicker than small distance.