Magnetic field shielding sheet and wireless power charging apparatus including the same

• US 9,853,487 B2
• Filed: 06/08/2016
• Issued: 12/26/2017
• Est. Priority Date: 10/13/2015
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Song, Yeong Hwan, Lee, Hyun Jung, Jang, Jae Hyuk
• Primary Examiner(s): Bernatz, Kevin M
• Application Number:
  US15/176,888
• Publication Number:
  US 20170104358A1
• Time in Patent Office: 566 Days
• Field of Search: None
• CPC Class Codes: H01F 27/08 Cooling heat-transfer elements F28F; Ventilating structural details of casings H01F27/02
• CPC Class Codes: H01F 27/22 Cooling by heat conduction through solid or powdered fillings
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• 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 50/10 using inductive coupling
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A magnetic field shielding sheet and a wireless power charging apparatus including the same are provided. A magnetic field shielding sheet includes a magnetic field shielding area including magnetic field shielding layers disposed on a surface of a coil part configured to provide a wireless power charging function to shield a magnetic field generated from the coil part and an adhesive layer bonding the magnetic field shielding layers to each other, and heat radiation fillers disposed within the adhesive layer.

Claims

1. A magnetic field shielding sheet, comprising:

a magnetic field shielding area comprising magnetic field shielding layers, disposed on a surface of a coil part configured to provide a wireless power, to shield a magnetic field generated from the coil part and an adhesive layer bonding the magnetic field shielding layers to each other; and

heat radiation fillers disposed within the adhesive layer, wherein a volume ratio of the heat radiation fillers within a first portion of the adhesive layer is different from a volume ratio of the heat radiation fillers within a second portion of the adhesive layer farther away from the coil part.

2. The magnetic field shielding sheet of claim 1, wherein a volume ratio taken up by the heat radiation fillers within the adhesive layer ranges from 0.05 to 0.8.

3. The magnetic field shielding sheet of claim 2, wherein the volume ratio of the heat radiation fillers within the second portion of the adhesive layer distal from the coil part is larger than the volume ratio of the heat radiation fillers within the first portion of the adhesive layer closer to the coil part than the first portion.

4. The magnetic field shielding sheet of claim 2, wherein the volume ratio of the heat radiation fillers within the first portion of the adhesive layer adjacent to the coil part is larger than the volume ratio of the heat radiation fillers within the second portion of the adhesive layer farther away from the coil part than the first portion.

5. The magnetic field shielding sheet of claim 1, wherein a diameter of each of the heat radiation fillers ranges from 0.05 μ

m to 10 μ

m.

6. The magnetic field shielding sheet of claim 1, further comprising a heat radiation layer disposed on at least one of an upper surface and a lower surface of the magnetic field shielding area.

7. The magnetic field shielding sheet of claim 6, wherein the heat radiation layer comprises different materials from the adhesive layer.

8. The magnetic field shielding sheet of claim 6, wherein a portion of the heat radiation fillers are disposed within the heat radiation layer.

9. The magnetic field shielding sheet of claim 1, wherein the heat radiation filler comprises at least one selected from the group consisting of graphite, graphene, alumina, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, and silicon nitride.

10. The magnetic field shielding sheet of claim 1, wherein the magnetic field shielding layers comprise at least one selected from the group consisting of ferrite, an amorphous metal ribbon, a nano-crystalline ribbon, and a metal polymer sheet.

11. The magnetic field shielding sheet of claim 1, wherein the magnetic field shielding sheets are split into pieces, and the adhesive layer is disposed between a portion of the pieces.

12. A wireless power charging apparatus, comprising:

a coil part comprising a first surface on which a conductive pattern is disposed and a second surface opposing the first surface;

a power circuit configured to charge a secondary cell battery by using power induced into the coil part;

a magnetic field shielding area comprising magnetic field shielding layers, disposed on the second surface, to absorb a magnetic field generated from the conductive pattern and an adhesive layer bonding the magnetic field shielding layers to each other; and

heat radiation fillers disposed within the adhesive layer, wherein a volume ratio of the heat radiation fillers within a first portion of the adhesive layer is different from a volume ratio of the heat radiation fillers within a second portion of the adhesive layer farther away from the coil part.

13. The wireless power charging apparatus of claim 12, wherein a volume ratio taken up by the heat radiation fillers within the adhesive layer ranges from 0.05 to 0.8.

14. The wireless power charging apparatus of claim 13, wherein the volume ratio of the heat radiation fillers within the second portion of the adhesive layer distal from the coil part is larger than the volume ratio of the heat radiation fillers within the first portion of the adhesive layer closer to the coil part than the first portion.

15. The wireless power charging apparatus of claim 13, wherein the volume ratio of the heat radiation fillers within the first portion of the adhesive layer adjacent to the coil part is larger than the volume ratio of the heat radiation fillers within the second portion of the adhesive layer farther away from the coil part than the first portion.

16. The wireless power charging apparatus of claim 12, further comprising a heat radiation layer disposed between the coil part and the magnetic field shielding area, wherein a thickness of the heat radiation layer ranges from 25% to 200% of that of at least one of the magnetic field shielding layers.