Printed wiring board

摘要

An insulative magnetic layer is disposed between a power source conductor layer and a ground conductor layer of a printed-wiring board. Two pieces of conductors are formed by cutting out a part of the power source conductor layer. Another two pieces of conductors are formed by cutting out a part of the ground conductor layer. The former conductors and the latter conductors are connected by five viaholes. A spiral coil inductor of a spiral form is formed in this way. This inductor has the strengthened inductance owing to the insulative magnetic layer provided therein. <IMAGE>