| 摘要 |
PROBLEM TO BE SOLVED: To reduce the dielectric constant of an adhesive insulation board inserted between printed wiring boards, thereby promoting high-speed processing signals to flow on conductive foils which are to be signal wirings provided on the printed wiring boards. SOLUTION: The multilayer printed wiring board is formed by heating and pressing laminated printed wiring boards 12, having conductive foils 11 for forming wirings in a multiple layer on at least one surface of an insulation board 10 via adhesive insulation boards 13, having an adhesive function. Hollow parts 13a are provided in a part of the adhesive insulation board 13; hollow parts 13a are provided in corresponding portions of the adhesive insulation board 13 to the peripheries of the conductive foils 11 to be signal wirings provided on the printed wiring boards 12; or if conductive foils 11 to be signal wirings are provided on the printed wiring board 12 at high density, hollow parts 13a are provided at random in the adhesive insulation board 13, thus forming a multilayer printed wiring board 14. |
