| 摘要 |
PURPOSE:To reduce the using amount of a noble metal by coating the sides of holes with nonconductive films when opening a plurality of holes at a metal lead frame and providing a noble metal plating layer on an island and the ends of inner leads, thereby preventing a plating layer from creeping to the side. CONSTITUTION:Resin films 7 which have holes at the portions 8 to be etched are provided on the front and back surfaces of a metal lead frame 6, etched and opened with a plurality of holes 9 passing the frame 6 at th frame 6. Then, nonconductive films 10 are bonded by electrodepositing painting only onto the sides 5 of the holes 9, and partially plating layers 11 made of silver are coated on the islands 13 of the separated frame 6 and on the ends 14 of the inner leads. Thus, the layers 11 do not creep to the holes 9, and the silver amount which forms the layers 11 can be reduced by that much. |
