| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dust core that fully suppresses noise without increasing the content of insulating material for improved mechanical hardness and strength. <P>SOLUTION: A dust core 10 contains large-diameter soft magnetic metal powders with a weight average particle diameter d<SB>w1</SB>ranging from 20 μm to 100 μm and small-diameter soft magnetic metal powders with a minimum particle diameter smaller than 20 μm and a weight average particle diameter d<SB>w2</SB>smaller than 20 μm. In addition, magnetic powders containing small-diameter soft magnetic metal powders of 10-80% by weight are coated by the insulating material and bonding agent and then press-molded and hardened in a predetermined form, so that noise under excitation due to an AC magnetic field can be fully suppressed without increasing the content of insulating material to increase mechanical hardness and strength. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
