| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To restrain core layer vias from inducing high impedance by narrowing an interval between core layer vias. <P>SOLUTION: In this method for manufacturing a multilayer printed wiring board, the core layer vias having a cylindrical conductive layer are so formed that conductive parts contact with each other, and then hole-punch working is performed along an axis of symmetry of the four core layer vias while penetrating a core substrate, to form through holes having a predetermined diameter, thereby the core layer vias 11, 11, ... separated from each other are formed. The through hole is filled with an insulator. Along a center axis of the through hole filled with the insulator, hole-punch working is so performed as to penetrate the core substrate to form through holes having a predetermined diameter smaller than that of the former through hole. A conductive layer is formed on the inner wall surface of the through hole to form a core layer via 9. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
