US Patent 7594105 Multilayer print circuit board

This invention effectively prevents potential fluctuation in the power supply terminal of a semiconductor device, that is, noise from flowing out to a main power supply wiring. A multilayer print circuit board includes a first power supply via hole which connects to the power supply terminal of a semiconductor integrated circuit on a first surface layer and extends from the first surface layer to a second surface layer, a ground via hole which connects to a ground conductive layer, extends from the ground conductive layer to the second surface layer, and connects to the first power supply via hole on the second surface layer through a bypass capacitor, a first clearance hole which is formed in a power supply conductive layer, and a second clearance hole which is formed in the ground conductive layer. The first clearance hole is larger than the second clearance hole.