Lead frame for semiconductor device

Abstract

Abstract PURPOSE:To obtain a stable workability with low cost by covering a plurality of die bonded regions, a plurality of wire bonded regions and the front and back surfaces of a plurality of the first and second leads with noble metal plating layers. CONSTITUTION:Silver plating layers are formed only on die bonded portions 10, wire bonded portions 14 and tie bar portions 15 and lead wirings 17 of necessary portions as a semiconductor device. When thus partly silver-plated, the silver amount is reduced, thereby supplying an inexpensive lead frame. In resin sealing, since a silver plating layer is not present on the lead frame of the air vent portion of a sealing mold, a suitable air gap of the air vent portion can be readily held, and externally pushing effect for air bubbles in the cavity can be obtained. Since the leads 17 are contacted with the mold, the silver and the resin can be readily separated since the silver and the resin has wrong contacting property. As the silver plating is executed on the entire lead wirings, preferable solderability and corrosion resistance can be obtained even if surface treatment is not performed in the next step, thereby reducing the cost, stabilizing the produciton and improving the quality.

Inventors

• 👤 Shinichi Miki
• 👤 神酒　慎一
• 👤 Shuji Obuchi
• 👤 大「淵」　修司

Bibliographic Details