Patent ID: 8029626
Filing Date: 2011-10-04
Classification: B22F,C22C,H01F

Abstract:
1. A method for producing a soft magnetic powdered core, comprising: a mixing step for forming a raw powder by adding 0.005 to 1 vol. % of a thermoplastic resin powder having a median size of not more than 50 μm to a soft magnetic powder coated with an electrical insulating film on a surface thereof; the thermoplastic resin powder comprised of a thermoplastic resin; and mixing the thermoplastic resin powder and the soft magnetic powder together; a compacting step for forming a compact by compacting the raw powder into a predetermined shape; a melting and setting step for the thermoplastic resin in which the thermoplastic resin of the compact is melted by heating the compact in one of a nitrogen gas atmosphere and an inert gas atmosphere to at least a melting point of the thermoplastic resin; and setting the melted thermoplastic resin by cooling the melted thermoplastic resin to room temperature; and a recrystallizing step for the thermoplastic resin in which the set thermoplastic resin is heated in an air atmosphere to a temperature range not less than an exothermic onset temperature measured by differential scanning calorimetry (DSC) analysis of the thermoplastic resin and to a temperature range not more than an endothermic onset temperature measured by DSC analysis of the thermoplastic resin, and cooling the set resin to room temperature.