FREE-NICKEL MULTI-LAYERED PLATING LAYER AND METHOD OF FORMING THE FREE-NICKEL MULTI-LAYERED PLATING LAYER

摘要

A free-nickel multi-layered plating layer and a forming method thereof are provided to form a plating layer in which precious metal is laminated on the top and bottom of silver, thereby improving corrosion resistance, abrasion resistance and thermal stability without nickel-plating. A free-nickel multi-layered plating layer comprises a first plating layer(120) 0.01~0.5mum thick, a second plating layer(130) 0.5~5mum thick, a third plating layer(140) 0.01~0.5mum thick, and a Cr^3+ plating layer(150). The first plating layer comprises palladium, platinum based metal, or gold. The second plating layer comprises silver. The third plating layer comprises palladium, platinum based metal, or gold. The first through third plating layers are laminated in the structure of palladium/silver/palladium, palladium/silver/gold, or gold/silver/gold. An alloy plating layer including two or more selected from the group consisting of copper, tin and zinc is formed on the bottom of the first plating layer.