Patent ID: 7936567

Claim:
A wiring board with built-in component, comprising: a core board including a core main surface, a core rear surface and an accommodation hole being open at least at the core rear surface, wherein a core main surface side conductor layer is formed on the core main surface, and a core rear surface side conductor layer is formed on the core rear surface; a component comprised of: a component main body including a component main surface, a component rear surface and a component side face; and a plurality of protruding conductors formed on the component rear surface in a protruding manner, wherein the component is accommodated in the accommodation hole with the core rear surface facing the same side as the component rear surface; a main surface side laminated wiring portion having a laminated structure in which a main surface side interlayer insulating layer and a main surface side conductor layer are laminated on the core main surface, and providing an integrated circuit element mounting region for mounting an integrated circuit element on a surface thereof; and a rear surface side laminated wiring portion having a laminated structure in which a rear surface side interlayer insulating layer and a rear surface side conductor layer are laminated on the core rear surface, and providing a connection terminal portion, which is connectable to a motherboard, on a surface thereof, wherein a surface of the core rear surface side conductor layer and a surface of a top portion of the plurality of protruding conductors are aligned in the same plane, wherein an arithmetic average coarseness of the surface of the core rear surface side conductor layer and the surface of the top portion is rougher than an arithmetic average coarseness of a surface of the core main surface side conductor layer, and wherein the core rear surface side conductor layer is thinner than the core main surface side conductor layer.