| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a radiated electromagnetic noise caused by a power source system composed of a power source layer and a ground layer when an IC or LSI is switched or operated in a multilayer printed circuit board. SOLUTION: A power source layer 4 of a multilayer printed circuit board 1 is wired so that an inductance element 10 having a structure where flat spiral interconnect lines 6a, 6b, which are spiral in plan view, are disposed in two vertical layers. The two flat spiral interconnect lines 6a, 6b connected to each other at the center is provided near LSI 12a, 12b. Furthermore, an insulating magnetic material is inserted at a position 7 between the upper and lower planar spiral interconnect lines 6a, 6b in layers over the entire substrate to allow the inductance element 10 to have high impedance to a high-frequency current.</p> |
