Magnetic core, magnetic component and electronic device

Patent metadata

Field	Value
Publication number	US-12569910-B2
Application number	US-202117411898-A
Country	US
Kind code	B2
Filing date	Aug 25, 2021
Priority date	Aug 25, 2020
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

A magnetic core including a magnetic powder. A total area ratio of particles of the magnetic powder in a cross section of the magnetic core is 75% or more and 90% or less. An average circularity of large size particles is 0.70 or more when the large size particles are particles extracted from the particles of the magnetic powder in the cross section of the magnetic core in the order of size from the largest size until a cumulative area ratio of the extracted particles reaches a smallest area ratio exceeding 20% of the total area ratio of the particles of the magnetic powder.

First claim

What is claimed is:

1 . A magnetic core comprising a magnetic powder, wherein
a total area ratio of particles of the magnetic powder in a cross section of the magnetic core is 75% or more and 90% or less, an average circularity of large size particles is 0.71 or more and 0.98 or less when the large size particles are particles extracted from the particles of the magnetic powder in the cross section of the magnetic core in the order of size from the largest size until a cumulative area ratio of the extracted particles reaches a smallest area ratio exceeding 20% of the total area ratio of the particles of the magnetic powder, and the magnetic core has a voltage resistance×relative permeability of 2132 V/mm or more, and 3504 V/mm or less, wherein voltage resistance was measured with electrodes at a distance between them of 8 mm.

2 . The magnetic core according to claim 1 , wherein an average circularity of the large size particles in the cross section of the magnetic core is 0.80 or more.

3 . The magnetic core according to claim 1 , wherein particle sizes of the large size particles in the cross section of the magnetic core are 5 μm or more and 50 μm or less.

4 . The magnetic core according to claim 1 , wherein an average elliptic circularity of the particles of the magnetic powder in the cross section of the magnetic core is 0.90 or more.

5 . The magnetic core according to claim 1 , wherein the large size particles have amorphous structures in the cross section of the magnetic core.

6 . The magnetic core according to claim 1 , wherein the large size particles in the cross section of the magnetic core have nanohetero structures in which a fine crystal having a crystal size of 0.3 nm or more and less than 5 nm exists in an amorphous phase.

7 . The magnetic core according to claim 1 , wherein the large size particles in the cross section of the magnetic powder have structures made of nanocrystals having crystal sizes of 5 nm or more and 50 nm less.

8 . The magnetic core according to claim 1 further comprising a resin.

9 . A magnetic component comprising the magnetic core according to claim 1 .

10 . An electronic device comprising the magnetic core according to claim 1 .

Assignees

• Tdk Corp

Inventors

• Yoshidome Kazuhiro
• Matsumoto Hiroyuki

Classifications

• B22F1/08

  Metallic powder characterised by particles having an amorphous microstructure · 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

• B22F2304/10

  Micron size particles, i.e. above 1 micrometer up to 500 micrometer · CPC title

• B22F9/082

  atomising using a fluid (using centrifugal force B22F9/10) · CPC title

• B22F2009/0872

  by water · CPC title