MAGNETIC CORE AND COIL COMPONENT

• US 20200135380A1
• Filed: 10/25/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: TONOYAMA, Kyohei, SATOH, Ken, SAITO, Kentaro, ASAI, Miyuki, OHKUBO, Hitoshi
• Granted Patent: US 11,657,949 B2
• Time in Patent Office: Days
• CPC Class Codes: H01F 1/15333 containing nanocrystallites, e.g. obtained by annealing
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 1/33 mixtures of metallic and non-metallic particles; metallic particles having oxide skin
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 27/324 Insulation between coil and core, between different winding sections, around the coil; Other insulation structures

Abstract

A magnetic core and a coil component with excellent permeability, core loss, DC superimposition property, and withstand voltage. A magnetic core has a metal magnetic powder containing resin including a metal magnetic powder. The metal magnetic powder includes a large size powder, an intermediate size powder, and a small size powder. A particle size of the large size powder is 10 μm or more and 60 μm or less. A particle size of the intermediate size powder is 2.0 μm or more and less than 10 μm. A particle size of the small size powder is 0.1 μm or more and less than 2.0 μm. The large size powder includes a nano crystal. A ratio of the large size powder existing with respect to the metal magnetic powder is 39% or more and 91% or less in terms of an area ratio in a cross section of the magnetic core.

Claims

1. A magnetic core comprising a metal magnetic powder, in which

the metal magnetic powder includes a large size powder, an intermediate size powder, and a small size powder,

a particle size of the large size powder is 10 μ

m or more and 60 μ

m or less,

a particle size of the intermediate size powder is 2.0 μ

m or more and less than 10 μ

m,

a particle size of the small size powder is 0.1 μ

m or more and less than 2.0 μ

m,

the large size powder includes a nano crystal, and

a ratio of the large size powder existing with respect to the metal magnetic powder is 39% or more and 91% or less in terms of an area ratio in a cross section of the magnetic core.

2. The magnetic core according to claim 1, wherein the intermediate size powder includes a nano crystal.

3. The magnetic core according to claim 1, wherein the small size powder includes a permalloy.

4. The magnetic core according to claim 1, wherein the nano crystal is a Fe-based nano crystal.

5. The magnetic core according to claim 4, wherein the Fe-based nano crystal includes Fe and M, and

M is one or more selected from the group consisting of Nb, Hf, Zr, Ta, Mo, W, and V.

6. The magnetic core according to claim 1, wherein the metal magnetic powder has an insulation coating.

7. The magnetic core according to claim 6, wherein an average thickness of the insulation coating is 5 to 45 nm.

8. The magnetic core according to claim 1, wherein a ratio of the intermediate size powder existing with respect to a ratio of the small size powder is 0.73 or more and 5.7 or less in terms of an area ratio in a cross section of the magnetic core.

9. The magnetic core according to the claim 1 including a metal magnetic powder including the nano crystal and also a metal magnetic powder which does not include the nano crystal as the metal magnetic powder, and

a ratio of the metal magnetic powder including the nano crystal with respect to entire magnetic metal powder is 40 wt % to 90 wt % in terms of a weight ratio.

10. A coil component having the magnetic core according to claim 1 and a coil.