| 摘要 |
PURPOSE: A four layer plating method is provided to obtain a plating layer which does not have almost no hydrogen brittleness and hair crack, and is flexible, particularly superior corrosion resistance on an Fe-Ni alloy material. CONSTITUTION: In a method for plating a palladium plating layer or a palladium alloy plating layer on an Fe-Ni alloy material, the plating method for improving corrosion resistance and crack resistance of an Fe-Ni alloy material comprises the processes of first substrate plating before plating a palladium layer or palladium alloy layer on a material to be plated so that a tin plating layer, a tin-lead alloy plating layer or a tin-bismuth alloy plating layer is formed on the material to be plated; second substrate plating thereon so that a copper plating layer or a copper-bismuth alloy plating layer is formed; and third substrate plating thereon so that a nickel plating layer is formed, wherein the material to be plated of the Fe-Ni alloy material is a semiconductor lead frame, and the palladium alloy layer is formed of an alloy selected from the group consisting of palladium-gold, palladium-silver and palladium-bismuth.
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