Patent ID: 11869691
Assignee: SUMITOMO ELECTRIC SINTERED ALLOY, LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B | IPC H

Claim 0:
1. A powder magnetic core comprising
a compact including soft magnetic powder;
a phosphate coating in a surface layer of the compact; and
an insulating-resin coating that covers a portion of a surface of the surface layer of the compact, the insulating-resin coating being situated on the phosphate coating,
wherein a ratio of an area of the insulating-resin coating to a surface area of the compact is greater than or equal to 32% and lower than or equal to 85%, and wherein a maximum depth of unevenness on a surface of the insulating-resin coating is greater than or equal to 7 μm and smaller than or equal to 20 μm,
wherein a film thickness of the phosphate coating is greater than or equal to 2 μm and less than or equal to 7 μm,
wherein a dielectric breakdown voltage across the insulating-resin coating is higher than or equal to 800 V, and
wherein a surface of the insulating-resin coating is free of a pinhole having a diameter of 100 μm or greater.