Ag or Ag-alloy plated Lead frame for semiconductor package and the method of manufacturing the same

摘要

PURPOSE: A lead frame for semiconductor package using silver plating or silver alloy plating and a method for fabricating the same are provided to reduce a manufacturing cost and prevent generation of cracks by using a small quantity of high-priced palladium-plated layer. CONSTITUTION: A nickel-plated layer(42) is formed on an upper portion of a metallic substrate(41). The nickel-plated layer(42) is formed with nickel or nickel alloy. A gold-plated layer(43) is formed on an upper portion of the nickel alloy-plated layer(42). The gold-plated layer(43) is formed with gold or silver. A silver-plated layer(44) is formed on an upper portion of the gold-plated layer(43). The nickel-plated layer(42) is used for preventing a diffusion phenomenon and an oxidation phenomenon of a base metal included in the metallic substrate(41) to an external plated layer. The gold-plated layer(43) is used for preventing the diffusion phenomenon and the oxidation phenomenon of the nickel-plated layer(42). The silver-plated layer(44) is used for maintaining characteristics of the lower plated layers(43,42).