| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer wiring board, in which the density of a signal layer can be increased, because it is superior in high-frequency characteristics and a noise-resistant properties, and which hardly influences the matching of a characteristic impedance. SOLUTION: In the multilayer wiring board comprising a structure in which a ground layer 1 or a power supply layer and the signal layer 3 are arranged via an insulation layer 2, the insulation layer 2 is constituted of a porous layer whose porosity is different in its thickness direction, and a face 2a on a side on which the porosity of the porous film is high is arranged on the side of the signal layer 3. |
