Magnetic sheet, coil module having magnetic sheet, and non-contact power supply device

Patent metadata

Field	Value
Publication number	US-12040112-B2
Application number	US-202016953590-A
Country	US
Kind code	B2
Filing date	Nov 20, 2020
Priority date	Dec 11, 2019
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

A magnetic sheet according to the present invention contains Mn—Zn ferrite as a main component and is comprised of a sheet-shaped sintered body. Besides, a ratio of ZMIN to ZMAX (ZMIN/ZMAX×100) is 90% or more, in which a maximum value of a content of Zn in terms of oxide is set to ZMAX and a minimum value of the content of Zn in terms of oxide is set to ZMIN in a thickness direction of a cross section of the sintered body.

First claim

What is claimed is:

1. A magnetic sheet comprising of a sheet-shaped sintered body,
wherein the sintered body contains Mn—Zn ferrite as a main component,
the Mn—Zn ferrite contains iron oxide in an amount of 51 to 58 mol % in terms of Fe 2 O 3 , zinc oxide in an amount of 3 to 18 mol % in terms of ZnO, and the balance is composed of manganese oxide (MnO), and
a ratio of Z MIN to Z MAX (Z MIN /Z MAX ×100) is 90% or more, in which a maximum value of a content of Zn in terms of oxide is set to Z MAX and a minimum value of the content of Zn in terms of oxide is set to Z MIN in a thickness direction of a cross section of the sintered body.

2. The magnetic sheet according to claim 1 , wherein an average thickness of the sintered body is 2500 μm or less.

3. The magnetic sheet according to claim 1 , wherein a standard deviation of the content of Zn in terms of oxide in the thickness direction of the cross section of the sintered body is 0.3 mol % or less.

4. A coil module comprising the magnetic sheet according to claim 1 .

5. A non-contact power supply device comprising the coil module according to claim 4 .

6. The magnetic sheet according to claim 1 , which has a front surface and a back surface, wherein the front surface or the back surface has an area of 2000 mm 2 or more.

7. The magnetic sheet according to claim 6 , wherein the area is 5000 mm 2 to 10000 mm 2 .

8. The magnetic sheet according to claim 2 , wherein the average thickness is 50 μm to 2500 μm.

9. The magnetic sheet according to claim 8 , wherein the average thickness is 100 μm to 2000 μm.

10. The magnetic sheet according to claim 8 , wherein the average thickness is 100 μm to 1000 μm.

11. The magnetic sheet according to claim 6 , wherein the ratio (area/volume) of an area of the front surface or the back surface to a volume of the magnetic sheet is 0.4 mm −1 or more.

12. The magnetic sheet according to claim 11 , wherein the ratio is 0.5 mm −1 or more.

13. The magnetic sheet according to claim 11 , wherein the ratio is 1 mm −1 or more.

14. The magnetic sheet according to claim 1 , which has an initial permeability μi of 1800 or more.

15. The magnetic sheet according to claim 14 , wherein the initial permeability μi is 2000 or more.

16. The magnetic sheet according to claim 14 , wherein the initial permeability μi is 2200 or more.

17. The magnetic sheet according to claim 1 , which has a magnetic loss of 1000 kW/m 3 or less.

18. The magnetic sheet according to claim 17 , wherein the magnetic loss is 800 kW/m 3 or less.

19. The magnetic sheet according to claim 17 , wherein the magnetic loss is 600 kW/m 3 or less.

Assignees

• Tdk Corp

Inventors

• Kubo Yoshihiro
• Oka Yoshito

Classifications

• C04B35/2658 Primary

  Other ferrites containing manganese or zinc, e.g. Mn-Zn ferrites · CPC title

• C04B2235/6025

  Tape casting, e.g. with a doctor blade · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title

• C04B2235/3239

  Vanadium oxides, vanadates or oxide forming salts thereof, e.g. magnesium vanadate · CPC title

• C04B2235/3251

  Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof · CPC title