Effect of electroless plating Ni–Cu–P layer on the wettability between cemented carbides and soldering tins

Abstract

Electroless plating method was adopted to prepare Ni–Cu–P layer on the surface of YT15 cemented carbide. The effect of electroless plating parameters (pH values, copper sulfate concentration, and reaction temperature) on the wettability between the cemented carbides and soldering tins was investigated by measuring the spreading area of the soldering tin on the cemented carbides surface and comparing it with that of cemented carbides without the Ni–Cu–P layer. The surface microstructure of the layer was analyzed using a scanning electronic microscope. The results show that the cemented carbides without the plating layer have extremely poor wettability with the soldering tin, and the soldering tin cannot spread on the cemented carbides surface. The electroless plating Ni–Cu–P layer apparently improves the wettability between the cemented carbides and soldering tins. In addition, the electroless plating parameters significantly affect the wettability between the cemented carbides surface and the soldering tin. At pH 11, 90°C plating temperature, and 1.25g/L copper sulfate concentration, the soldering tin exhibits an improved spreading property, and the surface Ni–Cu–P layer on the cemented carbides shows the optimum wettability with the soldering tin.