| 摘要 |
PROBLEM TO BE SOLVED: To provide a wiring board which reduces a size of the wiring board in a thickness direction and also reduces costs.SOLUTION: In a wiring board, multiple wiring layers and insulation layers formed of resin are laminated. The wiring board includes: a first insulation layer having one surface forming a surface of the wiring board and the other surface located at the opposite side of the one surface; a first pad that is provided with its surface exposed on the one surface of the first insulation layer; a first wiring line provided on the other surface of the first insulation layer and located adjacent to the first pad; an opening provided at the first insulation layer and exposing a rear surface of the first pad; a via that is provided in the opening and has one end connected with the rear surface of the first pad and the other end integrally provided with the first wiring line; and other insulation layers and other wiring layers that are laminated on the other surface side of the first insulation layer. The first insulation layer disposed between the first pad and the first wiring line is thinner than the insulation layers disposed between adjacent wiring lines at all insulation layers excluding the first insulation layer. |
