| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the noises of a signal efficiently by electrically connecting the electrode terminal of a noise filter and a ground layer through a wiring conductor layer having porosity within a specific range. SOLUTION: A noise filter 6 is mounted on the surface of the wiring board 1, a wiring conductor layer 5 having specific thickness and porosity of 4-25% is buried in the surface layer of the wiring board 1 corresponding to the lower region of the electrode terminal 8 of the side of the noise filter 6 connected to a ground layer 4 in the noise filter 6, and the wiring conductor layer 5 and the electrode terminal 8 of the noise filter 6 are connected by solder 9. The wiring conductor layer 5 and the ground layer 4 are joined directly, and the other electrode terminal 10 is joined with a pad 12 formed to the surface layer of the wiring board 1 by solder 9 through a via-hole conductor 11 from a signal line 3. Accordingly, noises from the signal line 3 can be reduced efficiently.</p> |
