公开(公告)号：US20180294084A1

公开(公告)日：2018-10-11

申请号：US15915901

申请日：2018-03-08

Applicant: TDK CORPORATION

Inventor： Masahiro KAMIYA ,  Yasuhide YAMASHITA ,  Chiomi SATO ,  Yousuke FUTAMATA ,  Ryoma NAKAZAWA ,  Takeshi TAKAHASHI ,  Hiroyuki ONO

IPC: H01F1/24 ,  H01F1/33 ,  H01F3/08 ,  B22F1/02 ,  H01F41/02 ,  C22C38/02

Abstract: A dust core includes a metal magnetic material, a resin, and an insulation film. The insulation film contacts with a surface of the metal magnetic material and covers the metal magnetic material. The insulation film includes a first film and a second film. The first film contacts with the surface of the metal magnetic material. The second film contacts with a surface of the first film. A density of the first film is higher than a density of the second film.