SEMICONDUCTOR PACKAGE AND METHOD FOR FORMING THE SAME

摘要

Semiconductor packages (100) that prevent the leaching of gold from back metal layers (118) into the solder (164) during the die attachment process and methods for fabricating the same are provided. A method in accordance with the invention comprises providing a semiconductor wafer stack (110) including a plurality of metal pads (112). An adhesion/plating layer (115) is formed on a surface (119) of a substrate (116). A layer of gold (118) is plated on a surface of the adhesion/plating layer (115). The layer of gold is etched in a street area (124) using standard photolithography techniques to expose edge portions (128) of the layer of gold (118) and the adhesion/plating layer (115). A layer of barrier metal (130) is deposited to form an edge seal (129) about the exposed edges (128) of the layer of gold (118) the adhesion/plating layer (115). The semiconductor wafer stack (110) is diced in the street area (124) and soldered to a leadframe (162) to form a semiconductor package (100) that provides for an edge seal (128) to prevent the leaching of gold from back metal layers (118) into the solder (162).