Semiconductor leadframes plated with thick nickel, minimum palladium, and pure tin

A leadframe for use with integrated circuit chips comprising:

• a base metal structure having a plated layer of nickel fully covering said base metal;
• a plated layer of matte, coarse grain, pure tin on said nickel layer, selectively covering areas of said leadframe suitable for parts attachment;
• and
• a plated layer of palladium or silver on said nickel layer, selectively covering areas of said leadframe suitable for bonding wire attachment.

A semiconductor device comprising:

• a leadframe comprising a chip mount pad for an integrated circuit chip and a plurality of lead segments, each having a first end near said mount pad and a second end remote from said mount pad;
• said leadframe having a surface layer of nickel;
• said leadframe further having a layer of palladium on said nickel layer, selectively covering said first ends of said lead segments in a thickness suitable for bonding wire attachment;
• an integrated circuit chip attached to said mount pad;
• bonding wires interconnecting said chip and said first ends of said lead segments;
• encapsulation material surrounding said chip, bonding wires and said first ends of said lead segments, while leaving said second ends of said lead segments exposed;
• and
• a layer of matte, coarse grain, pure tin solder on said nickel layer, selectively covering said second ends of said lead segments in a thickness suitable for parts attachment.