Wireless power transmission antenna with thermally conductive magnetic shield and method therefor

Patent metadata

Field	Value
Publication number	US-9912187-B2
Application number	US-201514842790-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Sep 1, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A carbon material and a magnetic material are incorporated at a magnetic shield included at a wireless power antenna. The magnetic shield shapes a magnetic flux field proximate to the magnetic shield. The carbon material conducts heat at the magnetic shield.

First claim

What is claimed is:

1. A method comprising:
incorporating a carbon material and a ferrous magnetic material at a magnetic shield immediately adjacent to a wireless power antenna at a wireless power transmission system, the magnetic shield to shape a magnetic flux field proximate to the magnetic shield, the carbon material to provide thermal conductivity at the magnetic shield to conduct heat generated at the wireless power antenna to a heat sink.

2. The method of claim 1 , wherein the carbon material provides orthotropic thermal conductivity and is arranged to conduct heat in a direction parallel to a primary plane of the magnetic shield.

3. The method of claim 1 , wherein the carbon material is arranged to conduct heat in a direction perpendicular to the primary plane of the magnetic shield.

4. The method of claim 1 , wherein the carbon material includes carbon nanotubes.

5. The method of claim 1 , wherein the carbon material includes graphite.

6. The method of claim 1 , wherein incorporating the carbon material at the magnetic shield comprises laminating a first sheet including the ferrous magnetic material and a second sheet including the carbon material, a wireless power inductor to attach to a major surface of the first sheet opposite the second sheet.

7. The method of claim 1 , wherein incorporating the carbon material at the magnetic shield comprises distributing chopped carbon nanotubes and the ferrous magnetic material homogeneously in a binder.

8. The method of claim 1 , wherein incorporating the carbon material at the magnetic shield comprises arranging a plurality of carbon nanotubes in a substantially parallel orientation within a binder, the binder further including a distribution of powdered iron or a powdered ferrite.

9. The method of claim 1 , wherein incorporating the carbon material at the magnetic shield comprises mixing carbon nanotubes in a binder to provide a mixture, and applying the mixture to a first major surface of a sheet of material containing powdered iron or a powdered ferrite, a wireless power inductor to attach to a second major surface opposite the first major surface.

10. A wireless power transmission system including a wireless power antenna device, the wireless power antenna device comprising:
an inductor;
a magnetic shield located immediately adjacent to the wireless power antenna, the magnetic shield including a ferrous magnetic material and a carbon material, the ferrous magnetic material to shape a magnetic flux field at the inductor, the carbon material to provide thermal conductivity at the magnetic shield to conduct heat generated at the inductor to the heat sink; and
a heat sink coupled to the magnetic shield.

11. The device of claim 10 , wherein the carbon material provides orthotropic thermal conductivity and is arranged to conduct heat in a direction parallel to a primary plane of the magnetic shield.

12. The device of claim 10 , wherein the carbon material is arranged to conduct heat in a direction perpendicular to the primary plane of the magnetic shield.

13. The device of claim 10 , wherein the carbon material includes carbon nanotubes.

14. The device of claim 10 , wherein the carbon material includes graphite.

15. The device of claim 10 , wherein the magnetic shield further comprises a lamination of a first sheet including the ferrous magnetic material and a second sheet including the carbon material, the first sheet adjacent to the inductor.

16. The device of claim 10 , wherein the ferrous magnetic material is included in a first sheet and the carbon material, suspended in an adhesive carrier is applied to a primary surface of the first sheet opposite the major surface to which the inductor is attached.

17. The device of claim 10 , wherein the inductor is a wireless power source antenna to transmit power to a target antenna, or a wireless power target antenna to receive power from a wireless power source antenna.

18. The device of claim 10 , wherein the ferrous magnetic material includes powdered iron or a ferrite material.

19. A wireless charging system comprising:
a wireless charging controller; and
a wireless charging antenna assembly coupled to the wireless charging controller, the antenna assembly including:
an inductor; and
a magnetic shield located immediately adjacent to the wireless power antenna, the magnetic shield including a ferrous magnetic material and a carbon material, the ferrous magnetic material to shape a magnetic flux field at the inductor, the carbon material to provide thermal conductivity at the magnetic shield.

20. The wireless charging system of claim 19 , wherein the ferrous magnetic material is included in a first sheet and the carbon material, suspended in an adhesive carrier is applied to a primary surface of the first sheet opposite the major surface to which the inductor is attached.

Assignees

• Dell Products Lp

Inventors

• Sultenfuss Andrew T
• North Travis C

Classifications

• H05K9/00

  Screening of apparatus or components against electric or magnetic fields (devices for absorbing radiation from an antenna H01Q17/00) · CPC title

• H02J50/23

  characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas · CPC title

• H02J50/70 Primary

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

• H01F38/14

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

• H02J7/04

  Regulation of charging current or voltage · CPC title