PLATING LAYER USING W-CO AND SN-CO AND METHOD FOR PLATING THE SAME

摘要

A plating method for forming a plating layer with excellent corrosion resistance, acid resistance, chemical resistance, hardness, abrasion resistance, adhesive property, and adhesion by electroplating W-Co and Sn-Co on a metal substrate is provided, and the plating layer formed by the plating method is provided. A plating method comprises the steps of: mixing water with a tungsten cobalt(W-Co) composition comprising 0.02 to 0.15 mol/L of cobalt sulfate, 0.01 to 0.3 mol/L of sodium tungstate, boric acid, monoboron phosphoric acid, or phosphoric acid, 0.01 to 0.5 mol/L of citric acid, sodium citrate, or ammonium citrate, 0.01 to 0.5 mol/L of a Rochelle salt, and 0 to 15 g/L of an additive to form a first electroplating layer on a substrate; and mixing water with a tin cobalt(Sn-Co) composition comprising 0.068 to 0.226 mol/L of tin chloride, 0.605 to 0.908 mol/L of potassium pyrophosphate, and 0.063 to 0.210 mol/L of cobalt chloride to form a second electroplating layer on the first electroplating layer. The substrate is metal. The plating method further comprises the step of electroplating a copper layer on the substrate. The tungsten cobalt(W-Co) comprises 30 to 60 wt.% of tungsten(W).