The effect of laser-soldering parameters on the Sn-Ag-Cu/Cu interfacial reaction

The effect of the fiber laser soldering parameters, laser-soldering output power and laser-soldering scanning speed, respectively, on the Sn-Ag-Cu/Cu interfacial reaction was investigated in this paper. When the output energy was very low, the Cu₆Sn₅ IMC was in scallop type with smooth surface; as the energy increased, the Cu₆Sn₅ grains showed the morphology of scallop type grains with faceted surface; further grew the energy, the scallop-type of Cu₆Sn₅ would be replaced by the prism-type Cu₆Sn₅; the Cu₆Sn₅ grains which were bottom closely arranged with a convex on the top can be found if the laser soldering energy was up again; when the laser soldering energy increased again, the plate-like Cu₆Sn₅ can be observed at the interface between the solder and Cu substrate.