Abstract: A wiring board including a core substrate made of an insulative material and having a penetrating portion, a first interlayer insulation layer formed on the surface of the core substrate, a first conductive circuit formed on the surface of the first interlayer insulation layer, a first via conductor formed in the first interlayer insulation layer, and an electronic component accommodated in the penetrating portion of the core substrate and including a semiconductor element, a bump body mounted on the semiconductor element, a conductive circuit connected to the bump body, an interlayer resin insulation layer formed on the conductive circuit, and a via conductor formed in the interlayer resin insulation layer. The first via conductor has a tapering direction which is opposite of a tapering direction of the via conductor in the electronic component.

Abstract: A printed wiring board including an insulation layer made of a resin material and having first and second surfaces, the insulation layer having an opening portion opened on the second surface, a conductive circuit having first and second surfaces, the conductive circuit being embedded in the insulation layer such that the first surface of the conductive circuit is formed flush with the first surface of the insulation layer and that the second surface of the conductive circuit is exposed through the opening portion of the insulation layer, a first surface-treatment film formed on the conductive circuit and facing the first surface of the conductive circuit, and a second surface-treatment film formed on the conductive circuit and facing the second surface of the conductive circuit and in the opening portion of the insulation layer.