Magnetic compact and inductor

Patent metadata

Field	Value
Publication number	US-12315661-B2
Application number	US-202117486789-A
Country	US
Kind code	B2
Filing date	Sep 27, 2021
Priority date	Sep 30, 2020
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A magnetic compact includes first magnetic particles, second magnetic particles with larger particle sizes than the first magnetic particles, and a resin. The area ratios calculated for multiple regions of the magnetic compact have a standard deviation of 0.40 or less, where area ratio=(total area of first magnetic particles)/(total area of second magnetic particles).

First claim

What is claimed is:

1. A magnetic compact comprising:
first magnetic particles;
second magnetic particles with larger particle sizes than the first magnetic particles; and
a resin,
wherein area ratios of the first and second magnetic particles calculated at a plurality of predetermined regions of the magnetic compact have a standard deviation of 0.40 or less, where
area ratio=(total area of the first magnetic particles)/(total area of the second magnetic particles),
the second magnetic particles have a particle size of from 10 to 28 μm, and
the first and second magnetic particles are iron-based particles,
wherein each of the predetermined regions is a region 10×D in length and 7.5×D in width, where D is a particle size corresponding to a bottom value representing a minimum particle frequency between a first peak value of the first magnetic particles and a second peak value of the second magnetic particles in a particle size distribution indicating a correlation between a particle frequency and a particle size.

2. The magnetic compact according to claim 1 , wherein
the standard deviation is 0.34 or less.

3. The magnetic compact according to claim 1 , wherein
the first magnetic particles and the second magnetic particles are metal magnetic particles.

4. The magnetic compact according to claim 3 , wherein
the metal magnetic particles contain at least one selected from the group consisting of Fe, an alloy containing Fe and Ni, an alloy containing Fe and Co, an alloy containing Fe and Si, an alloy containing Fe, Si, and Cr, an alloy containing Fe, Si, B, and Cr, and an alloy containing Fe, P, Cr, Si, B, Nb, and C.

5. The magnetic compact according to claim 1 , wherein
the resin is a thermosetting resin.

6. An inductor comprising:
a coil conductor; and
the magnetic compact according to claim 1 , which defines a winding core of the coil conductor.

7. The magnetic compact according to claim 2 , wherein
the resin is a thermosetting resin.

8. The magnetic compact according to claim 3 , wherein
the resin is a thermosetting resin.

9. The magnetic compact according to claim 4 , wherein
the resin is a thermosetting resin.

10. An inductor comprising:
a coil conductor; and
the magnetic compact according to claim 2 , which defines a winding core of the coil conductor.

11. An inductor comprising:
a coil conductor; and
the magnetic compact according to claim 3 , which defines a winding core of the coil conductor.

12. An inductor comprising:
a coil conductor; and
the magnetic compact according to claim 4 , which defines a winding core of the coil conductor.

13. An inductor comprising:
a coil conductor; and
the magnetic compact according to claim 5 , which defines a winding core of the coil conductor.

Assignees

• Murata Manufacturing Co

Inventors

• Ishida Keiichi
• Muneuchi Keita
• Fujisawa Nobuyuki
• Kimura Yoshinobu
• Hattori Yoshihiko

Classifications

• H01F2017/048

  with encapsulating core, e.g. made of resin and magnetic powder · CPC title

• H01F17/04 Primary

  with magnetic core · CPC title

• Y10T428/32

  Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• H01F27/255

  made from particles (H01F27/26 takes precedence) · CPC title