| 摘要 |
PROBLEM TO BE SOLVED: To provide a build-up multilayer printed wiring board where the amount of wiring is enhanced. SOLUTION: A build-up multilayer printed wiring board comprises core boards 21 and 22 which are stacked through an insulating layer 23 (a first insulating layer) and have build via holes 2 filled up with the insulating layer and blocked with pads 2a, a build-up insulating layer 25 (a second insulating layer) which are made on the surface of the core substrate 21, a base-piercing via hole 3 which pierces the core boards 21 and 22 and connect them electrically and is filled up with a third insulating layer 3, and a micro via hole 1 which is provided in the build-up insulating layer 25 and is made by plating in the opening reaching the pad 2a of the blind via hole 2. |
