| 摘要 |
[Problem] To provide, with a good yield, a multilayer printed wiring board that enables manufacturing cost to be reduced and makes it possible for the density to be increased with ease. [Solution] A sticky protective film (4) is affixed to a laminate board (3) clad with metal foil on one side; the sticky protective film (4) and an insulating resin film (1) are partially removed to form bottomed via holes (5), and an electroconductive paste (6) is packed in the bottomed via holes (5); and the sticky protective film (4) is peeled off, a part of the electroconductive paste (6) is allowed to protrude, and a wiring substrate (10) is produced. An adhesive protective layer (17) is formed so as to cover the patterned metal foil (12) of a laminate board (14) clad with metal foils on both sides; the adhesive protective layer (17) and an insulating resin film (11) are partially removed to form bottomed stepped via holes (18a), and an electroconductive paste (19) is packed therein; and a protective film (16) is peeled off, a part of the electroconductive paste (19) is allowed to to protrude, and a wiring substrate (20) is produced. The wiring substrate (10) and the wiring substrate (20) are laminated so that the protrusions (6a) of the electroconductive paste (6) and the protrusions (19a) of the electroconductive paste (19) are in contact with each other. |
