| abstract |
First to fourth power wiring conductors and first to fourth ground wiring conductors are arranged on first to fourth insulating layers, respectively, and a first signal wiring conductor is arranged on the first or second insulating layer and a second signal wiring conductor is arranged on the third or fourth insulating layer. In a multilayer circuit board of the invention, the first to fourth insulating layers are sequentially overlaid in the following manner: each of wiring conductors on the same insulating layer is arranged substantially in parallel to each other, each set of the first power wiring conductor and the second ground wiring conductor, the first ground wiring conductor and the second power wiring conductor, the third power wiring conductor and the fourth ground wiring conductor, and the third ground wiring conductor and the fourth power wiring conductor is arranged so that two wiring conductors are opposed to each other nearly in parallel while interposing the insulating layer therebetween, and each wiring on the first and second insulating layers and each wiring on the third and fourth insulating layers intersect at a right angle, and wherein the first to fourth power wiring conductors and the first to fourth ground wiring conductors are connected via thorough conductors disposed through the insulating layers. The inventive multilayer circuit board ensures a uniform characteristic impedance on the signal wiring conductor to enable a stable power supply to a semiconductor device. |