| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a substrate with a built-in coil having high resonance frequency and being small in size. <P>SOLUTION: A substrate with a built-in coil has a pair of insulating layers 1 with a wiring layer 5 formed; a ferrite magnetic substance layer 2 sandwiched between a pair of the insulating layers 1; a planar coil conductor 3 formed in the ferrite magnetic substance layer 2; and a ground conductor layer 4 formed between at least one of the insulating layers 1 and the ferrite magnetic substance layer 2. The substrate with the built-in coil is such that the ground conductor layer 4 has an opening part 4a, at a part overlapping with the planar coil conductor 3, in plan view. Since the capacitance between the planar coil conductor 3 and the ground conductor layer 4 is reduced by the opening part 4a, the substrate with the built-in coil has a higher resonance frequency. Furthermore, the substrate with the built-in coil further suppresses the influence due to noise radiation from the planar coil conductor 3, due to the shape of the opening part 4a and the corner parts of the planar coil conductor 3. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
