| 摘要 |
PURPOSE:To form high-speed signal wires in a high density in close proximity to each other on a printed circuit board and to prevent both high-speed signal wires from being electromagnetically coupled to each other. CONSTITUTION:A printed circuit board is manufactured into a constitution, wherein the board in provided with dielectric layers 22 which are arranged in close proximity to each other on an earth conductor layer 21, made of a low-dielectric constant material and have roughly a rectangle section, high-speed signal conductors 20 formed in the central parts of the respective layers 22 and a conductor layer 25 which is so formed as to cover the upper surfaces and both side surfaces of the respective layers 22 and has its left and right tails connected to the layer 21. |
