| 摘要 |
PURPOSE:To provide a multilayer printed wiring board capable of reducing EMI caused by radiation of electromagnetic waves from side faces of the board. CONSTITUTION:Circuit patterns 3a and 3b are formed on a multilayer printed wiring board 5A. A power source layer 1a set to a source potential and ground layer 2 are oppositely on both sides of a dielectric layer 6. An end dielectric layer 10 having a less dielectric const. than that of the layer 6 is formed at the fringe of the layer 6. Electromagnetic waves induced over the layers 1a and 2 at the fringe of the board 5A are attenuated by the layer 10 disposed at the fringe of the dielectric disposed between the layers 1a and 2. |
