| 摘要 |
PURPOSE:To augment power as well as heat dissipating capacity by a method wherein at least backside of a header is made of base metal as it is but not plating-processed. CONSTITUTION:A lead-frame composed of a lead 2, a header 4 and a guide 7 is made of a copper sheet patterned and bent by means of a precision press machine etc. Besides, the surface side of the header 4 fitted with chip 12 is coated with Ni plated layer 13 while the backside of the same 4 is not coated with the Ni plated layer 13 since the surface side only of the copper sheet is preliminarily Ni plated. In such a leadframe, another chip 11 is fixed on the header 4 using a solder 14 while the wire 12 made of aluminium is connected to the chip 11 by means of supersonic wirebonding process. At this time, the Ni plated layer 13 contributes to the excellent connection while the resin below the header 4 is made thinner to reduce the thermal resistance. |
