Patent ID: 8119920

Claim:
A multilayer printed wiring board comprising: a core substrate having a first surface and a second surface on an opposite side of the first surface; a plurality of first conductive layers formed on the first surface and second surface of the core substrate, respectively; a plurality of interlayer insulation layers formed on the first conductive layers, respectively, and the core substrate; and a plurality of second conductive layers formed on the interlayer insulation layers, respectively, wherein the plurality of first conductive layers on the core substrate includes a plurality of plane conductor layers formed on the first surface and second surface of the core substrate, respectively, the plurality of plane conductor layers of the first conductive layers includes at least one of a power source conductor and a grounding conductor, the core substrate has a through hole penetrating through the core substrate and connecting the first conductive layers on the first and second surfaces of the core substrate, the plurality of second conductive layers includes a plurality of conductor circuits formed on the interlayer insulation layers, respectively, the first conductive layers have a thickness which is larger than a thickness of the second conductive layers on the interlayer insulation layers, and each of the first conductive layers on the core substrate has a side face which is tapered such that an angle, Θ, formed by a straight line connecting the top end and bottom end of the side face of each of the first conductive layers and a horizontal face of the core substrate satisfies 2.8<tan Θ<55.