Magnetic material, electronic component, and method for manufacturing magnetic material

Patent metadata

Field	Value
Publication number	US-11869692-B2
Application number	US-201816009018-A
Country	US
Kind code	B2
Filing date	Jun 14, 2018
Priority date	Jun 26, 2017
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A magnetic material includes a soft magnetic metal grain containing Fe, and a multilayer oxide film covering the surfaces of the soft magnetic metal grain. The multilayer oxide film has a first oxide layer of crystalline nature containing Fe, and a second oxide layer of amorphous nature containing Si. In an embodiment, the silicon oxide film of amorphous nature is formed by dripping, divided into multiple sessions, a treatment solution containing TEOS (tetraethoxy silane), ethanol, and water into a mixed solution containing the soft magnetic metal grain, ethanol, and ammonia water, to mix the solutions.

First claim

We claim:

1. A magnetic material comprising:
a soft magnetic metal grain containing Fe; and;
a multilayer oxide film which has a layered structure of a first oxide layer containing Fe more than Si and a second oxide layer containing Fe and Si throughout the second oxide layer wherein Si is more than Fe, and which multilayer oxide film covers a surface of the soft magnetic metal grain, wherein the first oxide layer is crystalline and the second oxide layer is amorphous, and the first and second oxide layers are in contact with each other, and have a continuous layered structure covering the surface of the soft magnetic metal grain, wherein the second oxide layer has a thickness of 1 nm to 30 nm, which is greater than a thickness of the first oxide layer,
said multilayer oxide film further comprising:
a third oxide layer containing Fe and Cr, and
a fourth oxide layer containing Fe and Si,
wherein:
the third oxide layer is crystalline and the fourth oxide layer is amorphous,
the fourth oxide layer, the third oxide layer, the second oxide layer, and the first oxide layer are layered outwardly in this order from the surface of each soft magnetic metal grain, and
each soft magnetic metal grain is bonded to at least another soft magnetic metal grain by a bonding part which is constituted by a part of the first oxide layer.

2. The magnetic material according to claim 1 , wherein the soft magnetic metal grain is a pure iron powder.

3. The magnetic material according to claim 1 , wherein the soft magnetic metal grain is a soft magnetic alloy grain containing Fe, element L where element L is Si, Zr, or Ti, and element M where element M is not Si, Zr, or Ti, and oxidizes more easily than Fe.

4. An electronic component comprising a magnetic core constituted by an aggregate of the magnetic material according to claim 1 .

5. The magnetic material according to claim 1 , wherein the second oxide layer has a thickness of 5 nm to 25 nm.

6. The magnetic material according to claim 1 , wherein the second oxide layer covers all around the surface of the soft magnetic metal grain.

7. The magnetic material according to claim 1 , wherein the first oxide layer has a thickness of 0.5 nm to 10 nm.

Assignees

• Taiyo Yuden Kk

Inventors

• Orimo Yoko
• Li Xinyu
• Takeoka Shinsuke

Classifications

• H01F1/33 Primary

  mixtures of metallic and non-metallic particles; metallic particles having oxide skin · 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

• H01F1/342

  Oxides (H01F1/36 and H01F1/38 take precedence) · CPC title

• H01F1/38

  amorphous, e.g. amorphous oxides · CPC title

• H01F3/02

  made from sheets · CPC title