Patent ID: 8110750
Filing Date: 2012-02-07
Classification: H01L,H05K

Abstract:
1. A multilayer printed wiring board comprising: a core substrate; an interlayer insulation layer formed over the core substrate; a plurality of conductive layers formed over the core substrate; and a via hole for providing electrical connection between the conductive layers, wherein the plurality of conductive layers includes: a plane conductive layer formed on the core substrate and under the interlayer insulation layer, the plane conductive layer comprising a metal foil layer and a plurality of plated layers formed on the metal foil layer, and wherein the plane conductive layer formed on the core substrate has a side face in a form of rounded taper tapering toward the core substrate, and at least one conductive layer formed over the insulating layer; wherein the side face of the plane conductive layer formed on the core substrate and comprising a metal foil makes an angle, θ, formed by a horizontal face of the core substrate and a straight line connecting a top end and a bottom end of the side face of the plane conductive layer, and the angle, θ, satisfies 2.8<tan θ<55; wherein the plane conductive layer formed on the core substrate and comprising a metal foil has a thickness which is larger than a thickness of one of the conductive layers formed on the interlayer insulation layer.