Effects of nano-SiO2 additions on wettability and interfacial IMC growth of SAC solder on Ni-xSiO2 composite electroless clad layer

This paper prepares the Ni-SiO₂ composite barrier layer containing different concentration of SiO₂ nanoparticles (0g/L, 3g/L, 6g/L and 9g/L respectively). Moreover, it investigates the different concentration effects on the wettability of ternary eutectic Sn-Ag-Cu(SAC) solder on the Ni layer and the growth of interfacial intermetallic compounds(IMC) between the Sn-Ag-Cu solder and the composite coating. In this study, the Ni-xSiO₂ composite barrier layers with different concentration of SiO₂ nanoparticles were deposited on the surface of pure Cu plate by chemical plating technique. The max wetting Force (Fmax/mN) of SAC solder on the Ni-xSiO₂ surface, microstructure and the IMC growth of solder/Ni-xSiO₂ composite interface under different aging time at 170°C were discussed. In comparison with the Ni barrier without SiO₂, the wettability of SAC solder on the Ni-xSiO₂ surface will increase evidently. Cross-section studies indicate that added SiO₂ nanoparticles can inhibit interfacial IMC growth effectively.