Patent ID: 8319111

Claim:
A wiring board, comprising: a core board in which a through-hole conductor is formed along an inner wall of a through-hole which penetrates a plate-like core material in the thickness direction of the core board and a filler that is charged inside the through-hole conductor formed along the inner wall of the through-hole; a flange conductor formed at an open end of the through-hole and surrounding the filler inside the through-hole conductor, wherein said flange conductor electrically connects said stacked via to the through-hole conductor, a first wiring laminate portion formed in such a manner that a plurality of conductor layers and a plurality of layer-shaped interlayer insulating material forming resin insulating layers are alternately laminated on a first major plane of the core board, and a plurality of via conductors used for an electrical connection between the conductor layers are embedded in the interlayer insulating material of the resin insulating layers, wherein the via conductors embedded in the interlayer insulating material of the resin insulating layers are stacked in a series of four or more layers in the thickness direction of the core board and constituting a stacked via which is electrically connected to the through-hole conductor, said stacked via located in an area not on the through-hole, wherein the interlayer insulating material is made of a resin material having a linear thermal expansion coefficient of 35 ppm/K or more to 50 ppm/K or less, wherein the core material is made of a resin material having a linear thermal expansion coefficient of 20 ppm/K or more to 30 ppm/K or less, and wherein the filler is made of a resin material having a linear thermal expansion coefficient of 20 ppm/K or more to 35 ppm/K or less.