MULTILAYER CIRCUIT BOARD

PROBLEM TO BE SOLVED: To overcome a problem that simultaneous noise and EMI noise are increased in a multilayer circuit board mounting electronic components which operate at high speed. SOLUTION: In this multilayer circuit substrate 1, a plurality of integrated capacitors having different resonant frequencies are arranged in an insulation substrate 2, and the composed impedance value at an antiresonant frequency is set to be not larger than a prescribed value. Power supply wiring layers or ground wiring layers 4-6 are surrounded by annular magnetic body layers 11-13 formed on their outsides. EMI noise generating in the multilayer wiring substrate 1 can be adsorbed by the annular magnetic body layers 11-13. By connecting the annular magnetic body layers 11-13 each other by using through- magnetic bodies 14, EMI noise radiated from between the power supply wiring layers or ground wiring layers 4-6 to the outside can be adsorbed to reduce the noise effectively, and additionally, by setting the distance between the through-magnetic bodies 14 to be not longer than 1/4 of the operating signal wavelength in a semiconductor element 9, the EMI noise can be drastically reduced. COPYRIGHT: (C)2003,JPO