| abstract |
PROBLEM TO BE SOLVED: To provide a method for reliably and inexpensively plating excellent adhesion on the surface of a lead having a small external shape of a lead frame used for an integrated circuit chip. SOLUTION: A nickel layer 23a completely covering a base material, 23b pre-plates a continuous piece 20 of sheet-like base material, pre-plates one surface with a palladium layer 24 of a thickness suitable for bonding wire attachment, and palladium or metal of a thickness suitable for component attachment. Pre-plate the opposite surface with a layer 25 of lead-free solder. The leadframe structure is then die-cut from the sheet, exposing the base material at the die-cut end to enhance adhesion to the molding compound. |