Hitherto, various types of structures of a multilayer printed wiring board including a built-up portion in which a plurality of wiring patterns that are stacked with insulating layers therebetween are electrically connected through via holes provided in the insulating layers have been proposed. For example, in such a multilayer printed wiring board, when a semiconductor device mounted is switched between the on and off states at a high speed, switching noise may be generated, resulting in an instantaneous drop in the electric potential of a power supply line. In order to suppress such an instantaneous drop in the electric potential, connection of a capacitor portion between the power supply line and a ground line to perform decoupling has been proposed. In Patent Document 1, provision of a layered capacitor portion functioning as such a capacitor portion in a multilayer printed wiring board has been proposed.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-68858