US Patent 7692300 Printed circuit board and circuit structure for power supply

In a printed circuit board, a semiconductor including plural power supply terminals and a semiconductor chip is mounted onto a mounting surface of a printed wiring board, and a bypass capacitor for reducting a power ground noise is provided. Another bypass capacitor, which is connected to the bypass capacitor only within an IC chip is provided to inhibit the power ground noise from causing not only a variation in timing of the IC chip and a malfunction thereof but also a malfunction of another IC chip and the generation of an EMI noise in a case where the power ground noise propagates to a power supply side.