PRE-PLATED LEAD FRAME FOR COPPER WIRE BONDING

摘要

A pre-plated lead frame comprises a substrate comprising copper or a copper alloy which has a first side and a second side opposite to the first side. A first plating layer comprising nickel is plated on the first and second sides of the substrate and a second plating layer comprising palladium is plated onto the first plating layer on the first and second sides of the substrate. A third plating layer comprising gold is then plated onto the second plating layer on the second side of the substrate, the third plating layer on the second side of the substrate having a thickness of more than 3 nm. On the first side of the substrate, there is either no gold plated onto the second plating layer, or a third plating layer comprising gold plated onto the second plating layer which has a thickness of 1.5 nm or less.