Patent ID: 8334463

Claim:
A wiring board, comprising: a first rigid wiring board comprising a substrate having a penetrating hole, a first insulation layer formed on the substrate and covering an opening of the penetrating hole, and a first wiring layer formed on the first insulation layer; a second rigid wiring board accommodated in the penetrating hole, the second rigid wiring board comprising a second wiring layer on a surface of the second rigid wiring board and a fourth wiring layer on a surface opposite the surface on which the second wiring layer is formed; a first connection conductor connecting the first wiring layer and the second wiring layer; and a first interlayer insulation layer formed on the first wiring layer, wherein the second rigid wiring board comprises a second substrate and an inner wiring layer formed on the second substrate, and the second wiring layer and the fourth wiring layer are electrically connected to each other through the inner wiring layer formed on the second substrate; wherein the first rigid wiring board has a second insulation layer formed on the substrate to cover the other opening of the penetrating hole, and a third wiring layer formed on the second insulation layer; and the wiring board further comprises a second connection conductor which connects the third wiring layer and the fourth wiring layer, and a second interlayer insulation layer formed on the third wiring layer.