| 摘要 |
PURPOSE:To provide a lead frame having enough shear strength by a method wherein a copper oxide film is provided to the surface of a part of the lead frame which is sealed up with molding resin, and the main structure of the copper oxide film is formed of a needle crystal aggregate provided with voids. CONSTITUTION:A copper alloy plate material composed of 2.0% Sn, 0.2% Ni, and the residual % of Cu is patterned into the shape of a lead frame 1 through a conventional etching method. A die pad 2 and the tips of inner leads 3 serving as an Ag plating section 4 located on a die pad side are covered with synthetic rubber photoresist, and a copper oxide film 9 of structure composed of needle crystal aggregate provided with voids is formed. An anodizing process is carried out under such conditions that an electrolytic solution is set to 0.6M potassium hydroxide and 0.3M magnesium hydroxide in composition, an anodizing current is set to 0.3M/dm<2> in density, and a temperature is set to 55 deg.C. A part where the copper oxide film 9 has been formed is covered with a protective body of silicon rubber, and an Ni base plating and an Ag plating are provided. |
