Effect of in Addition on Thermodynamic Properties, Wettability, Interface Microstructure, and Soldering Performance of SnBiAg–xIn/Cu Solder Joints

In this experiment, a Sn35Bi0.3Ag–xIn (x = 0, 0.5, 1.0, 1.5) alloy solder was prepared by electromagnetic induction heating furnace. The effects of on the thermodynamic properties, wettability, interface microstructure, and soldering performance Sn35Bi0.3Ag–xIn/Cu joints were studied synchrotron thermal analyzer (DSC), contact-angle measuring instrument, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), universal tensile testing machine. research showed that adding small amount reduced solid–liquid temperature improved wettability solder. At SnBiAg–xIn/Cu joint, it found atoms replaced part Sn atoms, forming Cu6 (Sn, In)5 phase scallop-like Cu3 In) phase. When 0.5% 1.0% elements, Bi appeared side layer, which hindered growth intermetallic compound (IMC) thickness IMC layer. Among them, layer SnBiAg–1.0In/Cu joint smallest, shear strength highest, 55.1 MPa. addition, fracture morphology observed, mode brittle fracture, fractured from side.