| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a multilayer printed circuit board, which can suppress electromagnetic noise radiated from power and grounding layers when an IC or LSI is switched or is operating. SOLUTION: In the multilayer printed circuit board, two or more sorts of insulator magnetic material layers 6a and 6b are formed between power and grounding layers 4 and 3. The insulator magnetic material contain magnetic powder and resin. The powder contains two or more kinds of substances, powder volume ratios, mean particle diameters, etc. The power layer 4 is wired so that an inductor element 10 is present near LSIs 12a and 12b. An insulator magnetic material of two or more sorts of substances or having two or more sorts of volume ratios and mean particle diameters may be inserted between the power and grounding layers 4 and 3.</p> |
