Wireless charging apparatus

Patent metadata

Field	Value
Publication number	US-9973026-B2
Application number	US-201514812536-A
Country	US
Kind code	B2
Filing date	Jul 29, 2015
Priority date	Jul 29, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Disclosed are a soft magnetic alloy and a wireless charging apparatus including the soft magnetic alloy. The soft magnetic alloy has a chemical formula expressed as Fe 100-x-y Cu x B y (wherein x ranges from 0.1 at % to 1.7 at % and y ranges from 2.3 at % to 9.6 at %). Without adding any expensive alloying element, only iron (Fe), copper (Cu), and boron (B) are used to obtain a nanocrystalline soft magnetic alloy that has a low coercive force and a high saturation magnetic flux density. The nanocrystalline soft magnetic alloy is applied to a wireless power transmitter and a wireless power receiver. Thereby, it is possible to make a shield member thin and increase a power transmission capacity. The soft magnetic alloy is easily processed into a flake form. The soft magnetic alloy processed in this way is applied to the shield member. Thereby, it is possible to increase permeability in a surface direction.

First claim

What is claimed is:

1. A wireless charging apparatus comprising:
a soft magnetic material; and
a coil disposed on the soft magnetic material,
wherein the soft magnetic material includes a soft magnetic alloy that has a chemical formula expressed as Fe 100-x-y Cu x B y , where x ranges from 0.1 at % to 1.7 at % and y ranges from 2.3 at % to 3.9 at %, and grains with a size from 10 nm to 99 nm;
wherein the soft magnetic alloy has a saturation magnetic flux density of 1.7 T to 1.9 T and a coercive force of 30 Oe to 40 Oe, and
wherein the soft magnetic alloy has a saturation magnetization of 190 emu/g to 200 emu/g in absolute value when a magnetic field with a strength exceeding ±7500 Oe is applied to the soft magnetic alloy.

2. The wireless charging apparatus of claim 1 , wherein the soft magnetic alloy has a flake form.

3. The wireless charging apparatus of claim 2 , wherein the soft magnetic alloy is processed into the flake form through a ball milling process.

4. The wireless charging apparatus of claim 2 , wherein the soft magnetic alloy is subjected to a heat treatment process in the flake form to remove residual stress.

5. The wireless charging apparatus of claim 4 , wherein the heat treatment process is performed at a temperature of 250° C. to 450° C.

6. The wireless charging apparatus of claim 2 , wherein the flake form has an aspect ratio of 10 or more.

7. The wireless charging apparatus of claim 1 , wherein the grains are formed in an amorphous matrix made by solidifying the Fe—Cu—B alloy in a molten state using a water quenching method.

8. The wireless charging apparatus of claim 7 , wherein the Fe—Cu—B alloy for the grains is heated to a temperature of 1700° C. or more for the molten state.

9. The wireless charging apparatus of claim 1 , wherein the grains are each formed in such a manner that Fe and B are bonded to Cu acting as a crystalline nucleus.

10. A wireless charging apparatus comprising:
a wireless power transmitter that includes a soft magnetic core containing a first soft magnetic alloy and a transmission coil; and
a wireless power receiver that includes a soft magnetic sheet containing a second soft magnetic alloy and a reception coil;
wherein at least one of the first soft magnetic alloy and the second magnetic alloy has a chemical formula expressed as Fe 100-x-y Cu x B y , where x ranges from 0.1 at % to 1.7 at % and y ranges from 2.3 at % to 3.9 at %, and grains with a size from 10 nm to 99 nm;
wherein at least one of the first soft magnetic alloy and the second soft magnetic alloy has a saturation magnetic flux density of 1.7 T to 1.9 T and a coercive force of 30 Oe to 40 Oe, and
wherein at least one of the first soft magnetic alloy and the second soft magnetic alloy has a saturation magnetization of 190 emu/g to 200 emu/g in absolute value when a magnetic field with a strength exceeding ±7500 Oe is applied to the soft magnetic alloy.

11. The wireless charging apparatus of claim 10 , wherein a permanent magnet is disposed on the soft magnetic core.

12. The wireless charging apparatus of claim 10 , wherein a near field communication (NFC) antenna is disposed on the soft magnetic sheet.

Assignees

• Lg Innotek Co Ltd

Inventors

• Bae Seok
• Song Ji Yeon
• Moon Won Ha
• Lee Sang Won
• Lee Jong Hyuk
• Hyun Soon Young

Classifications

• H02J50/12 Primary

  of the resonant type · CPC title

• H02J50/10

  using inductive coupling · CPC title

• H01F1/15308

  based on Fe/Ni (H01F1/15325 takes precedence) · CPC title

• H01F38/14 Primary

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title

• H02J50/70

  involving the reduction of electric, magnetic or electromagnetic leakage fields · CPC title