| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a multilayer substrate device allowing a circuit device that is mounted on a multilayer substrate to reduce the effects of noise in the relationship with a ground layer. <P>SOLUTION: A second field-effect transistor 112 and capacitors 102 and 106 of a power system constituting a power supply circuit arranged in a wiring board 131 are grounded to a power system ground layer 104. On the other hand, a DC-DC converter control IC 115 and an external LSI 123 that are arranged on the wiring board 131 and are other circuits for mainly processing signals are connected with a general ground layer 119 as a layer different from the power system ground layer 104. The power system ground 104 and the general ground layer 119 are connected by a fourth via-hole 118 at the position where loop current 145 is hard to affect the circuits for processing signals. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
