Patent attributes
The present disclosure is directed to a lead frame design that includes a copper alloy base material coated with an electroplated copper layer, a precious metal, and an adhesion promotion compound. The layers compensate for scratches or surface irregularities in the base material while promoting adhesion from the lead frame to the conductive connectors, and to the encapsulant by coupling them to different layers of a multilayer coating on the lead frame. The first layer of the multilayer coating is a soft electroplated copper to smooth the surface of the base material. The second layer of the multilayer coating is a thin precious metal to facilitate a mechanical coupling between leads of the lead frame and conductive connectors. The third layer of the multilayer coating is the adhesion promotion compound for facilitating a mechanical coupling to an encapsulant around the lead frame.