| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a package board without causing a malfunction or error even when an IC chip in a high-frequency range, in particular, an IC chip which exceeds 3 GHz is mounted. <P>SOLUTION: A multilayer printed wiring board 10 includes a plurality of through-holes 36 for connecting the front and back sides thereof to each other, wherein interlayer insulation layers 50, 150 and conductor layers 158 are formed on a multilayer core board 30 of three or more layers having front and back conductor layers 34 and a conductor layer 16 of an inner layer. The plurality of through-holes 36 are constituted of through-holes 36P for power, through-holes 36E for the grounding and through-holes for signals which are connected to a power circuit, grounding circuit or signal circuit of an IC chip 90; and at least the through-hole, immediately under the IC out of the through-holes 36P for power does not include a conductor circuit that is extended, when penetrating a grounding conductor layer 16E of the inner layer. The present invention is improved, in particular, first and second voltage drops out of voltage drops occurring after turning on a switch. <P>COPYRIGHT: (C)2011,JPO&INPIT |
