Preplating of semiconductor small outline no-lead leadframes

摘要

For a leadframe for use with integrated circuit chips, a continuous strip of sheet-like base metal is pre-plated with a layer of nickel fully covering the base metal, further on one surface with a palladium layer in a thickness suitable for bonding wire attachment, and on the opposite surface with a layer of either palladium or lead-free solder in a thickness suitable for parts attachment. The leadframe structure is then stamped from the sheet so that the base metal is exposed at the stamped edges, enhancing adhesion to molding compounds.