| 摘要 |
PROBLEM TO BE SOLVED: To provide a high density wiring board capable of transmitting a high frequency signal at low loss.SOLUTION: A wiring board consists of an insulating substrate in which an insulating layers 7 of an inner layer is stacked below an insulating layer 7 of a surface layer, a plurality of semiconductor element connection pads 10 having a pair 10P of semiconductor element connection pads for signal formed on the insulating layer 7 of a surface layer, and a pair of belt-like wiring conductors 12P formed on an insulating layer 7 of the inner layer, having a connection edge connected to the pads 10P through a via hole 6 just below semiconductor element connection pads 10P for signal and parallel extension parts 12A extending parallel to each other from a vicinity of the connection edge on the insulating layer 7 of the inner layer. In the pair of belt-like wiring conductor 12P, a width from the connection edge to a part of the parallel extension parts 12A has length less than 1/16 of the length of the signal transmitting the pair 12P of the belt-like wiring conductors and is less than that of a residue. |
