Patent ID: 8033015

Claim:
A method of suppressing power supply noise of a printed wiring board, said method comprising: providing a predetermined free area on a signal layer interposed between a respective power supply layer and a respective ground layer, such that the predetermined free area on said signal layer is substantially overlapped by one of said power supply layer and said respective ground layer; and providing at least one of a wiring region for power supply connections and a wiring region for ground connections in said predetermined free area of the signal layer, wherein a component surface of said printed wiring board including a plurality of electrodes is configured to mount a semiconductor device having a bottom surface facing said component surface; said component surface of said printed wiring board includes a plurality of pads for being connected with said electrodes of said semiconductor device, respectively, and through holes connected to said pads, respectively, are arranged in a periphery side of said semiconductor device with respect to said pads; and said wiring region on the signal layer corresponding to said predetermined free area extends in the form of a cross corresponding to vertical and horizontal center lines of said bottom surface of said semiconductor device.