Dust core

Patent metadata

Field	Value
Publication number	US-10811176-B2
Application number	US-201815913964-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Mar 9, 2017
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A dust core includes a metal magnetic material, a resin, an insulation film, and an intermediate layer. The insulation film covers the metal magnetic material. The intermediate layer exists between the insulation film and the metal magnetic material and contacts therebetween. The metal magnetic material includes 85 to 99.5 wt % of Fe, 0.5 to 10 wt % of Si, and 0 to 5 wt % of other elements, with respect to 100 wt % of the entire metal magnetic material. The intermediate layer includes a Fe—Si—O based oxide. The insulation film includes a Si—O based oxide.

First claim

The invention claimed is:

1. A dust core comprising:
a metal magnetic material;
a resin;
an insulation film covering the metal magnetic material; and
an intermediate layer existing between the insulation film and the metal magnetic material and contacting therebetween,
wherein the metal magnetic material comprises 85 to 99.5 wt % of Fe, 0.5 to 10 wt % of Si, and 0 to 5 wt % of other elements, with respect to 100 wt % of the entire metal magnetic material,
wherein the intermediate layer comprises a Fe—Si—O based oxide, and
wherein the insulation film comprises a Si—O based oxide.

2. The dust core according to claim 1 , wherein 6.0<W Fe /W si <9.0 is satisfied, where W Fe (wt %) is a Fe content of the intermediate layer, and W Si (wt %) is a Si content of the intermediate layer, provided that a total of the Fe content and the Si content of the intermediate layer is 100 wt %.

3. The dust core according to claim 1 , wherein 0<D<50 nm is satisfied, where “D” (nm) is a thickness of the intermediate layer.

4. The dust core according to claim 2 , wherein 0<D<50 nm is satisfied, where “D” (nm) is a thickness of the intermediate layer.

5. The dust core according to claim 1 , wherein the metal magnetic material is present in an amount of 90 wt % to 98 wt %, and the resin is present in an amount of 2 wt % to 10 wt %.

6. The dust core according to claim 1 , wherein 6.1≤W Fe /W si ≤8.9.

7. The dust core according to claim 1 , wherein 6.3≤W Fe /W si ≤8.6.

Assignees

• Tdk Corp

Inventors

• FUTAMATA Yousuke
• Nakazawa Ryoma
• Takahashi Takeshi
• Shimamura Junichi

Classifications

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• B22F1/16

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

• H01F1/26 Primary

  by macromolecular organic substances · CPC title

• H01F1/24 Primary

  the particles being insulated · CPC title

• H01F1/14766 Primary

  Fe-Si based alloys · CPC title