LEAD FRAME AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A method for forming a lead frame is provided to prevent a plate layer from being lifted or cracked by nodules on a thin film material, by eliminating the nodules which obstruct wire-bonding in forming a semiconductor device and solder wettability in surface mounting process. CONSTITUTION: The surface of the thin film material is electrolyzed and degreased. The degreased thin film material is electrolyzed and polished. Inclusion on the polished thin film material is eliminated. The thin film material is cleaned in an acid solution. A plurality of plate layers are formed on the cleaned thin film material. When the inclusion is nonconductive, supersonic waves are irradiated to the surface of the thin film material to remove the inclusion.