SEMICONDUCTOR PACKAGE EQUIPPED WITH THREE-DIMENSIONAL PRINTED BOARD

摘要

PURPOSE:To enable a semiconductor package to be enhanced in number of outer leads without increasing it in external size and lessening the leads in wire width and pitch and surface-mounted on a printed board without causing defective soldering. CONSTITUTION:A metal base board is composed of a metal plate 12 and copper foil layers 14 and 16 which are laminated on the metal plate 12 through the intermediary of insulating layers 13 and 15 and where circuits are provided, and a flange 18 is provided to the peripheral edge of an opening 17 of the metal base board by bending and drawing. The copper foil layers 14 and 16 are so formed as to be exposed like steps at the flange 18 to serve as a correspondent part to outer leads. A semiconductor integrated circuit device 11 is mounted on the metal base board through the opening 17 and connected to the copper layers 14 and 16 with bonding wires 19. When a semiconductor package 10 is surface-mounted on a printed board, the stepped part provided to the flange 18 is made to correspond to pads formed on the printed board.