| 摘要 |
[PROBLEMS] To provide a multilayer printed wiring board for obtaining fine pitch. [MEANS FOR SOLVING PROBLEMS] In a build-up wiring layer, a heat resistant substrate (30) is incorporated in a multilayer printed wiring board (10), an interlayer resin insulating layer (50) and a conductor layer (58) are alternately laminated on the heat resistant substrate, and conductor layers are connected by via holes (60). Since the heat resistant substrate composed of a Si substrate (20) is used, a wiring thinner than that formed on an uneven resin substrate can be formed by making via holes (48) on the surface of the mirror-finished Si substrate, and thus, fine pitch is obtained. Furthermore, by forming a wiring on the mirror-finished surface, variance of the wiring is reduced and fluctuation of impedance is reduced. |
