PURPOSE: To obtain a lead frame having a plated layer being resistive to oxidation in the desired thickness by providing a solder plated layer to a circuit mounting surface directly or through a metal layer.
CONSTITUTION: A lead frame 1 has three leads 2. The center lead (for collector) is longest having a header 5 which provides a circuit element mounting surface 4 for fixing circuit element at the other end. The header 5 is supported by a frame 6 in both sides. The lead frame 1 can be obtained by punching a copper plate 8 with a press and then patterning it. The surface is coated by a nickel plated film 9. The circuit element mounting region of header 5 is formed with a solder plated film 10. A tin plated film is formed on the film 10 as a non- oxidized metal protection film 11 in order to prevent oxidation of solder plated film 10.
YAMAGUCHI MASAO
INABA KEIZOU
AKEYAMA KENJI
IKEZAWA RIYUUICHI
