Patent ID: 9711440
Date: 2017-07-18
CPC Classifications: H01L,H05K

Claim:
1. A wiring board, comprising: a core substrate comprising a core insulating layer and a conductor layer formed on a surface of the core insulating layer; and a build-up layer laminated on one side of the core substrate and comprising an inter-layer insulating layer and a conductor layer laminated on the inter-layer insulating layer, wherein the core substrate has an opening portion penetrating through the core insulating layer such that a surface of the conductor layer in the core substrate is forming a bottom surface of the opening portion, the core substrate has a via conductor formed in the opening portion and comprising plating material filling the opening portion, the conductor layer in the core substrate comprises a metal foil and a plating film formed on the metal foil in the core substrate, the conductor layer in the build-up layer comprises a metal foil and a plating film formed on the metal foil in the build-up layer, and the metal foil in the core substrate has a surface in contact with the surface of the core insulating layer such that the surface of the metal foil in the core substrate is set to have a surface roughness which is smaller than a surface roughness of a surface of the metal foil in the build-up layer in contact with the inter-layer insulating layer.