| 摘要 |
<p>A method for improving the high-frequency characteristics of a through-hole via in a multilayer printed circuit board, in which the top and bottom of the through-hole via open to power/ground planes, has been proposed. However, there is the problem that having openings increases the resistance of the power/ground planes, making power supply to the LSI chip difficult. Thus, a multilayer printed circuit board is disclosed, said circuit board comprising: build-up layers (21a) layered on both sides of a core layer (20); a cylindrical external conductor (15) going through the core layer (20); a central conductor (11) formed inside the core layer (20) so as to constitute a coaxial structure together with the external conductor (15); and an insulator (18) between the central conductor (11) and the external conductor (15). Wiring on the build-up layers (21a) is disposed opposite both ends of the central conductor (11). The disclosed multilayer printed circuit board is characterized by the provision of signal vias (12a) at both ends of the central conductor (11), the diameters of said signal vias (12a) being smaller than the diameters of the ends of the central conductor (11).</p> |
