MULTILAYER CIRCUIT BOARD, AND MOTOR-DRIVING CIRCUIT BOARD

摘要

Provided is a multilayer circuit substrate having wiring lines arranged to reduce an inductance. A grounded wiring line (22) and a power-source wiring line (33), which are mounted in the multilayer circuit substrate (100), are arranged such that they almost entirely overlap vertically along the longitudinal direction of the board. Electric currents flow in opposite directions at the overlapping portions so that the magnetic fields generated cancel each other. Likewise, a W-phase wiring line (11), a V-phase wiring line (21) and a U-phase wiring line (31) are arranged to overlap partially vertically along the longitudinal direction, so that the magnetic fields to be generated by the electric currents to flow in the vertically overlapping portions cancel each other. Therefore, the inductances of the wiring lines can be decreased by increasing the mutual inductances between those wiring lines.