DUST CORE AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a dust core having a low cost and excellent inductance DC superposition characteristics and a method for manufacturing the same.SOLUTION: The method for manufacturing dust core comprises: mixing a pure iron powder sieved with an opening of 70μm or less and an insulating resin to form an insulating coating in the periphery of the pure iron powder; pressure molding the pure iron powder having the formed insulating coating into a predetermined form in the state that a lubricant is added; and heat-treating the molding in a non-oxidizing atmosphere. In the pressure molding, the insulating coating formed on the surface of the pure iron powder constituting the molding is maintained to be a quality factor of 10 or more when a current of 100 kHz is supplied to a reactor using the completed dust core. The crush of the insulating coating formed on the surface of the pure iron powder constituting the molding stays within 100μm from the surface of the molding.