| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multilayer wiring board which can reduce power supply impedance at an antiresonant frequency while keeping the power supply impedance at a resonant frequency low. <P>SOLUTION: Between a power source and a ground of an IC 50 mounted on a multilayer wiring board 1, one or more (two in Fig. 1) high ESR capacitors 70 each having an ESL of 1 nH or less and an ESR of no fewer than 1.5 Ω nor more than 20 Ω, and one or more (two in Fig. 1) low ESR capacitors 60 each having an ESL of 1 nH or less and an ESR of 100 mΩ or less are connected in parallel. The multilayer wiring board 1 can reduce impedance at an antiresonant frequency less than half (equivalent of -6 dB noise reduction) in comparison with the case provided with only low ESR capacitors 60, while keeping power supply impedance at a resonant frequency low. <P>COPYRIGHT: (C)2012,JPO&INPIT |
