| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a coil built-in substrate which incorporates a coil that suppresses occurrence of unwanted magnetic flux to provide an excellent electrical characteristic as an inductor. <P>SOLUTION: A coil conductor 9 is formed at a part of a first magnetic material layer 61 and a second magnetic material layer 62 as well as at a predetermined ferrite sheet in an intermediate non-magnetic material layer 60. In the coil conductor 9, an outer coil conductor 9L which has a large diameter and an inner coil conductor 9S whose diameter is smaller than the outer coil conductor, are alternately stacked through the magnetic material layer or the intermediate non-magnetic material layer. The coil conductors 9 are connected together in series in the order of stacking, to form a coil. The outer coil conductor 9L and the inner cool conductor 9S are alternately arranged. Between layers of the coil conductors 9L adjoining each other along the stacking direction, as well as between layers of the coil conductors 9S, a low magnetic permeability region 80 is provided respectively. With this configuration, an invalid magnetic flux ϕs that passes between the coil conductors 9 adjoining each other is hard to occur, and valid magnetic flux ϕm which is essentially required increases. <P>COPYRIGHT: (C)2012,JPO&INPIT |
