Magnetic compact and inductor

Patent metadata

Field	Value
Publication number	US-2022102036-A1
Application number	US-202117486789-A
Country	US
Kind code	A1
Filing date	Sep 27, 2021
Priority date	Sep 30, 2020
Publication date	Mar 31, 2022
Grant date	—

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).

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 magnetic compact has a bottom value representing a minimum particle frequency between any two of peak values in a particle size distribution indicating a correlation between a particle frequency and a particle size, the first magnetic particles have particle sizes smaller than a particle size corresponding to the bottom value, and the second magnetic particles have particle sizes larger than the particle size corresponding to the bottom value.

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

5 . The magnetic compact according to claim 4 , 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.

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

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

8 . The magnetic compact according to claim 2 , wherein
the magnetic compact has a bottom value representing a minimum particle frequency between any two of peak values in a particle size distribution indicating a correlation between a particle frequency and a particle size, the first magnetic particles have particle sizes smaller than a particle size corresponding to the bottom value, and the second magnetic particles have particle sizes larger than the particle size corresponding to the bottom value.

9 . The magnetic compact according to claim 2 , wherein
the first magnetic particles and the second magnetic particles are metal magnetic particles.

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

11 . The magnetic compact according to claim 8 , wherein
the first magnetic particles and the second magnetic particles are metal magnetic particles.

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

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

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

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

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

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

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

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

20 . An inductor comprising:
a coil conductor; and the magnetic compact according to claim 6 , 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

• H01F1/26

  by macromolecular organic substances · CPC title

• H01F17/04 Primary

  with magnetic core · CPC title

• H01F2017/048

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

• H01F27/255

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

• H01F41/0246

  Manufacturing of magnetic circuits by moulding or by pressing powder (magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36) · CPC title