Dust core

Patent metadata

Field	Value
Publication number	US-2018294084-A1
Application number	US-201815915901-A
Country	US
Kind code	A1
Filing date	Mar 8, 2018
Priority date	Mar 9, 2017
Publication date	Oct 11, 2018
Grant date	—

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.

First claim

1 . A dust core comprising:
a metal magnetic material; a resin; and an insulation film contacting with a surface of the metal magnetic material and covering the metal magnetic material, wherein the insulation film comprises: a first film contacting with the surface of the metal magnetic material; and a second film contacting with a surface of the first film, and wherein a density of the first film is higher than a density of the second film.

2 . The dust core according to claim 1 , wherein each of the first film and the second film comprises a Si—O based oxide.

3 . The dust core according to claim 2 , wherein the first film and the second film comprise different contrasts from each other observed by TEM.

4 . The dust core according to claim 2 , wherein 1.25<I 1 /I 2 <10.0 is satisfied, where I 1 is a Si detection intensity of the first film, and I 2 is a Si detection intensity of the second film, in TEM-EDS analysis of the first film and the second film.

5 . The dust core according to claim 3 , wherein 1.25<I 1 /I 2 <10.0 is satisfied, where I 1 is a Si detection intensity of the first film, and I 2 is a Si detection intensity of the second film, in TEM-EDS analysis of the first film and the second film.

6 . The dust core according to claim 1 , wherein 0.075<D 1 /D 2 <10.0 is satisfied, where D 1 is a thickness of the first film, and D 2 is a thickness of the second film.

7 . The dust core according to claim 2 , wherein 0.075<D 1 /D 2 <10.0 is satisfied, where D 1 is a thickness of the first film, and D 2 is a thickness of the second film.

8 . The dust core according to claim 3 , wherein 0.075<D 1 /D 2 <10.0 is satisfied, where D 1 is a thickness of the first film, and D 2 is a thickness of the second film.

9 . The dust core according to claim 4 , wherein 0.075<D 1 /D 2 <10.0 is satisfied, where D 1 is a thickness of the first film, and D 2 is a thickness of the second film.

10 . The dust core according to claim 5 , wherein 0.075<D 1 /D 2 <10.0 is satisfied, where D 1 is a thickness of the first film, and D 2 is a thickness of the second film.

11 . The dust core according to claim 1 , wherein the metal magnetic material comprises a main component of Fe.

12 . The dust core according to claim 2 , wherein the metal magnetic material comprises a main component of Fe.

13 . The dust core according to claim 3 , wherein the metal magnetic material comprises a main component of Fe.

14 . The dust core according to claim 4 , wherein the metal magnetic material comprises a main component of Fe.

15 . The dust core according to claim 6 , wherein the metal magnetic material comprises a main component of Fe.

16 . The dust core according to claim 1 , wherein the metal magnetic material comprises a main component of Fe and Si.

17 . The dust core according to claim 2 , wherein the metal magnetic material comprises a main component of Fe and Si.

18 . The dust core according to claim 3 , wherein the metal magnetic material comprises a main component of Fe and Si.

19 . The dust core according to claim 4 , wherein the metal magnetic material comprises a main component of Fe and Si.

20 . The dust core according to claim 6 , wherein the metal magnetic material comprises a main component of Fe and Si.

Assignees

• Tdk Corp

Inventors

• Kamiya Masahiro
• Yamashita Yasuhide
• Sato Chiomi
• FUTAMATA Yousuke
• Nakazawa Ryoma
• Takahashi Takeshi
• Ono Hiroyuki

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• H01F3/08

  made from powder (powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06) · CPC title

• C22C38/02

  containing silicon · CPC title

• H01F1/24 Primary

  the particles being insulated · CPC title

• H01F1/26

  by macromolecular organic substances · CPC title