Multi-Layered Magnetic Shields

• US 20140177197A1
• Filed: 12/26/2012
• Published: 06/26/2014
• Est. Priority Date: 12/26/2012
• Status: Abandoned Application

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Lampinen, Harri Armas
• Application Number:
  US13/726,779
• Publication Number:
  US 20140177197A1
• Time in Patent Office: Days
• US Class Current: 361/818
• CPC Class Codes: H01F 2003/106 Magnetic circuits using combinations of different magnetic materials
• 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: H05K 9/0075 Magnetic shielding materials
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A device may include a multiple layer ferrite shield to protect device components during charging of a battery of the device based on magnetic induction. In some examples, the device may include a ferrite shield comprising a first layer and a second layer. The first layer may be composed of a material having first magnetic properties and the second layer may be composed of a material having second magnetic properties. Further, the first magnetic properties may be different from the second magnetic properties.

Claims

1. An apparatus comprising:

a magnetic shield comprising a first layer and a second layer, wherein the first layer comprises a material having a first magnetic permeability and the second layer comprising a material having a second magnetic permeability, wherein the first magnetic permeability is different from the second magnetic permeability and the magnetic shield is configured to reduce exposure of at least one internal component of an electronic device to a magnetic field.

2. The apparatus of claim 1, wherein a thickness of at least one of the first and second layers is non-uniform over a length of the magnetic shield.

3. The apparatus of claim 1, wherein the first magnetic permeability is approximately 130 and the second magnetic permeability is approximately 10,000.

4. The apparatus of claim 1, wherein the first magnetic permeability is approximately 130 and the second magnetic permeability is approximately 500.

5. The apparatus of claim 1, wherein a thickness of the first layer is approximately 200 micrometers.

6. The apparatus of claim 1, wherein a thickness of the second layer is approximately 80 micrometers.

7. The apparatus of claim 1, wherein a thickness of the first layer is approximately 70 micrometers.

8. The apparatus of claim 1, wherein a thickness of the first layer differs from a thickness of the second layer.

9. The apparatus of claim 1, wherein the first layer is composed of a ferrite material.

10. The apparatus of claim 1, wherein the second layer is composed approximately of Fe₇₃Cu₁Nb₃Si₁₆B₇.

11. The apparatus of claim 1, wherein the magnetic shield comprises a third layer.

12. A method comprising:

creating a first layer having a first magnetic permeability and a first thickness;

creating a second layer having a second magnetic permeability and a second thickness; and

creating a magnetic shield by adhering the first layer to the second layer.

13. The method of claim 12, further comprising varying the first thickness over a length of the magnetic shield.

14. The method of claim 12, further comprising varying the second thickness over a length of the magnetic shield.

15. The method of claim 12, wherein the first magnetic permeability differs from the second magnetic permeability.

16. The method of claim 12, further comprising forming one or more of the layers into a an irregular geometric shape.

17. A device comprising:

at least one internal component; and

a magnetic shield comprising a first layer and a second layer, wherein the first layer is composed of a material having a first magnetic permeability and the second layer is composed of a material having a second magnetic permeability, wherein the first magnetic permeability is different from the second magnetic permeability and the magnetic shield is configured to protect the at least one internal component from a magnetic field during charging.

18. The device of claim 17, further comprising a receiving coil configured to receive the magnetic field for charging of a battery.

19. The device of claim 17, wherein the magnetic shield comprises a third layer.

20. The device of claim 17, wherein a thickness of at least one of the first and second layers is non-uniform over a length of the magnetic shield.