Production method of laminating double-side circuit board and multi-layer printed circuit board using it

The present invention comprises a plurality of laminating double-side circuit boards and a plurality sheets of prepreg for interlayer connection that are placed one on another. Via holes extend from the circuit on one side of each laminating double-side circuit board to the circuit on the other side thereof. Each via hole is filled with electro-conductive material to connect the circuits on both sides of the laminating double-side circuit board. The pad on a laminating double-side circuit board and the pad on another laminating double-side circuit board are laminated via a sheet of prepreg for interlayer connection so that the respective pads are opposed to each other via the through hole filled with electro-conductive material formed through the sheet of prepreg for interlayer connection. Thereby, the respective pads on the laminating double-side wiring circuit boards are electrically connected with one another. Thus, the present invention can provide a multilayer printed wiring board having shorter production time, excellent reliability, and high yield.