PURPOSE: To remarkably lessen a printed wiring board in cross talk noise by a method wherein a part where a grounding wire connected to a ground layer through a plated through-hole is provided to another layer separate from a signal wire by an insulating layer in parallel with and adjacent to the signal wire is provided.
CONSTITUTION: A printed wiring board is provided with a signal wire 1, a ground wire 2, an insulating layer 3, a through-hole 4 used for electrical conduction, a ground layer 5, and a power supply layer 6, where the signal wire 1 and the ground wire 2 are provided onto different layers separated from each other by the insulating layer 3 adjacent to and in parallel with each other. The signal wire 1 and the ground wire 2 are formed through such a manner that a conductive metal foil is laminated on an insulating layer, resists is provided to the required part of the metal foil, and the disused part of the metal foil is removed by etching or the surface of an insulating layer is selectively electroless-plated to form a wiring circuit on the insulating layer. By this setup, a printed wiring board of this design can be enhanced in shield effect and lessened in cross-talk noise.
NAKADA KENICHI
OKANO SHINICHI
YOSHITOMI YASUNOBU
YOKOSUKA HIROJI
