| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the waveform of signal is disordered and the quality of signal is deteriorated during the transmission of the signal when the signal at several hundreds MHz is transmitted between a mother board and a memory module through a bus wire in a semiconductor memory device. SOLUTION: The positional relationship between a bus wiring layer and a conductive layer such as a power supply layer or a ground layer which is opposed to the bus wiring layer among multilayer wiring layers is substantially kept not only in a mother board but also in the memory module and the multilayer wiring relation is standardized. In consequence, the disorder of feedback current of high-frequency signal applied to the bus wiring layer is reduced, the deterioration of signal waveform due to the disorder of the feedback current is prevented and the radiation of unwanted electromagnetic wave due to the disorder of the feedback current is also prevented. If the positional relationship between the bus wiring layer and the opposed conductive layer can not be maintained in a constant way, the same effect can be obtained also by arranging a by-pass capacitor in proximity to the part where the planes are switched between the bus wiring layer and the conductive layer. COPYRIGHT: (C)2003,JPO
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