| 摘要 |
<p>PURPOSE:To form a six-plane shielded structure with a less man-hour by mounting parts of six-plane shielded structure on the surface of a board of the first layer, and shielding them with dedicated small frame-shaped shielding cases. CONSTITUTION:Parts of six-plane shielded structure are placed in the wiring pattern 12a on a board 21 of the first layer together with other electronic parts in the same assembling process. The parts of six-plane shielded structure are mounted in a way that they penetrate boards 22, 23 of the second and third layers and extend to the underside of a board 24 of the fourth layer, and are soldered there. Small frame-shaped shielding cases 13, 13 dedicated to the six- plane shielded structures, are mounted on the first layer board 21 in a way that they penetrate the second and third layer boards 22, 23 and extend to the underside of the fourth layer board 24. The shielding cases are soldered there. The resultant four-layered wiring board is installed in a frame-shaped chassis base. A lid is placed on the opening at the top of the chassis base. The lid also functions as lids of the shielding cases 13, 13, and thus covers the opening at the top of the shielding cases 13, 13. This makes it possible to shield six planes using the lid, the shielding cases 13, and the first earth pattern 12b on the second layer board 22.</p> |
