| 摘要 |
PURPOSE:To obtain excellent solderability at cost extremely lower than gold, silver and a tin-cobalt alloy by plating a molded conductive semiconductor lead-frame base body with an alloy in which the content of nickel to tin is specified. CONSTITUTION:A lead-frame base body for a semiconductor is molded, and pre-treated. The whole surface including a tie bar 2 is plated by using an alloy at the ratios of 45-85% tin and 55-15% nickel, thus completing a lead frame 1. 55-80% tin and 45-20% nickel are employed as the most preferable ratios on the characteristics of products in an experiment at that time. 0.3-0.4mm are used normally in the frame base body for the semiconductor and approximately 0.25mm is employed in one for an IC as the thickness of the frame base body for the semiconductor, and an electroplating means is used as a plating means. An IC silicon chip 7 is welded to the lead frame 1 completed. Connecting wires 8, 8 such as gold wires, aluminum wires, copper wires or the like each tying the silicon chip 7 and leads 4, 4 on both sides are bonded. |
