| 摘要 |
PURPOSE:To reduce the thickness of a printed circuit board forming a recess on a chip placing portion on the board to become lower than the other portion, and directly placing a semiconductor chip in the recess, thereby forming the resin- sealed surface in the same plane as a laminated board as much as possible. CONSTITUTION:A circuit pattern 2a except a semiconductor chip placing portion is formed on a copper-lined laminated board, a recess 1a is formed by mechanical cutting, and a circuit pattern 2b is formed in the recess 1a to conduct between the external circuit patterns 2a and a semiconductor chip bonding. A semiconductor chip 3 is placed on the recess circuit pattern 2b obtained in this manner, wire bonded at 4, resin-sealed at 5. Thus, further reduced thickness than the normal chip-on board can be performed. Since the anxiety of unnecessarily flowing out sealing resin can be eliminated, it is not necessary to mount a frame, to increase the density and is advantageous in the cost and working steps. |
