| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulating sheet for wiring board that eliminates the need for machining of a via hole, and prevents the misalignment between a wiring circuit layer and a through conductor, and to provide the multilayer wiring board of the insulating sheet, and a manufacturing method of the multilayer wiring board. SOLUTION: A wiring circuit layer 2 where a conductive projection 3 with a specific height is formed is formed on the surface of a transfer sheet 1, at least thermosetting resin 4 is contained, a conductive particle 5 is contained in the ratio of 5 to 30 vol.% in a total amount, the transfer sheet 1 is laminated and pressed onto the surface of an insulating sheet 6 where solder with a low melt point of 240 deg.C or less is contained into the conductive particle 5 by 5-50 vol.%, the transfer sheet 1 is peeled off, the wiring circuit 2 where the conductive projection 3 is formed is transferred to the insulating sheet 6 for forming, at the same time, the conductive projection 3 is buried in the insulating sheet 6 for condensing the conductive particle 5, and the wiring circuit layers 2 formed at both the sides of an insulating layer are mutually and electrically connected to the conductive projection 3 that is provided at one wiring circuit layer 2 via an aggregation section 8 due to the conductive particle 5. |
