| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring substrate having three wiring layers for a package which can be adapted to high density mounting, can particularly reduce the total thickness of a substrate thinner, and can solve the problem of the power loss of the input and output of a high frequency signal with excellent productivity as compared with a conventional wiring layer of a four-layer build-up multilayer wiring substrate. SOLUTION: The three-layer wiring substrate includes a three-layer wiring layer having only one of wiring layers 123, 121 formed by a subtractive method on both front and back surfaces of a core wiring substrate having one-layer wiring layer 122A in a resin substrate layer 110. In the three-layer wiring substrate, a conductive part formed by plating is provided in a through hole 146B of a resin substrate layer formed by a laser, the through hole 146B is formed electrically connecting wirings of the wiring layers of the front and back surfaces of the core wiring substrate, a conductive part 193B formed by plating is provided in the hole of the resin substrate layer formed by the laser, and a blind via 145B is formed for electrically connecting the wirings of the wiring layers of the front and back surfaces of the core wiring substrate to the wiring of an internal wiring layer. COPYRIGHT: (C)2005,JPO&NCIPI |
