Wireless charging apparatus

• US 9,973,026 B2
• Filed: 07/29/2015
• Issued: 05/15/2018
• Est. Priority Date: 07/29/2014
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Bae, Seok, Song, Ji Yeon, Moon, Won Ha, Lee, Sang Won, Lee, Jong Hyuk, Hyun, Soon Young
• Primary Examiner(s): Bernatz, Kevin M
• Application Number:
  US14/812,536
• Publication Number:
  US 20160036264A1
• Time in Patent Office: 1,021 Days
• Field of Search: None
• CPC Class Codes: H01F 1/15308 based on Fe/Ni H01F1/15325 takes precedence
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

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-yCu_xB_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.

Claims

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-yCu_xB_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-yCu_xB_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.