DUST CORE FOR HIGH FREQUENCY AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide an ideal dust core constitution having a specific resistance of larger than or equal to 2Ωcm and a further reduced iron loss, and a method for manufacturing the dust core. SOLUTION: A dust core is manufactured by the use of magnetic metal powder coated with insulating films formed through chemical conversion coating, using a phosphate and a thermosetting resin powder. The thickness of the insulating films coating the metal powder is adjusted to 10-100 nm, and the dust core contains the metal powder at a rate higher than or equal to 84 vol.% and the thermosetting resin powder at a rate higher than or equal to >=1 wt.%, so that the specific resistance of the dust core is formed larger than or equal to 2Ωcm.