METHODS FOR FORMING SHIELD MATERIALS ONTO INDUCTIVE COILS

• US 20170011840A1
• Filed: 09/19/2016
• Published: 01/12/2017
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Graham, Christopher S., Jol, Eric S., Brzezinski, Makiko K.
• Granted Patent: US 10,043,612 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 1/147 Alloys characterised by their composition treatment thereof for enhancing their electromagnetic properties C21D8/12
• CPC Class Codes: H01F 27/02 Casings
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 27/288 Shielding
• 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 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: Y10T 29/49021 Magnetic recording reproducing transducer [e.g., tape head, core, etc.]

Abstract

Methods of and systems for directing flux from a transmit coil to a receive coil within an inductive power transfer system are disclosed. For example, a transmit coil may be shielded with a contoured shield made from a ferromagnetic material. The contoured shield may contour to several surfaces of the transmit coil so as to define a single plane through which flux may be directed to a receive coil.

Claims

1. A shield for an annular coil comprising:

a first portion; and

a second portion coupled to the first portion, wherein the first and second portions are contoured over at least two surfaces of the annular coil.

2. The shield of claim 1 wherein the shield is made from soft magnetic material.

3. The shield of claim 2 wherein the shield is made from at least one of iron, iron silicates, iron-cobalt, manganese-zinc, nickel, or nickel-zinc.

4. The shield of claim 1 wherein the shield is made from a doped material selected from plastic, glass, or composite material.

5. The shield of claim 4 wherein the doped material comprises a dopant made from a metal powder.

6. The shield of claim 1 further comprising a third portion coupled to the first and second portions.

7. The shield of claim 1 further comprising an adhesive layer disposed between the shield and the annular coil.

8. The shield of claim 7 wherein the adhesive layer comprises a heat activated film.

9. The shield of claim 7 wherein the adhesive is made from a doped material comprising a dopant made from a metal powder.

10. The shield of claim 1 wherein:

the annular coil comprises a plurality of windings of an electrical conductor defining an interior coil sidewall, an exterior coil sidewall and a back surface extending between the interior and exterior coil sidewalls;

the first portion is contoured to either the interior or exterior sidewall; and

the second portion comprises a ring contoured to the back surface.

11. The shield of claim 1 wherein the annular coil is contained within a first housing.

12. A shield for an annular coil comprising:

a first portion comprising a plurality of individual petals; and

a second portion comprising a ring and coupled to the first portion, wherein the first and second portions are contoured over at least two surfaces of the annular coil.

13. The shield of claim 12 further comprising a filler material disposed between adjacent individual petals of the plurality of individual petals.

14. The shield of claim 12, further comprising a third portion coupled to the first and second portions, wherein the second portion is disposed between the first and third portions.

15. The shield of claim 14 wherein the third portion comprises a plurality of individual petals positioned across the second portion from the plurality of individual petals of the first portion.

16. The shield of claim 14 further comprising a filler material disposed between adjacent individual petals of the plurality of individual petals.

17. An inductive charging system comprising:

an electronic device comprising;

an annular receive coil; and

a shield contoured over at least two surfaces of the receive coil.

18. The inductive charging system of claim 17 wherein the shield defines a receiving area of the receive coil for concentrating magnetic flux therethrough.

19. The inductive charging system of claim 18 wherein the shield is a first shield, and the inductive charging system further comprises:

an inductive charging device comprising;

a housing comprising an interface surface for receiving the electronic device;

a transmitter coil within the housing and positioned below the interface surface; and

a second shield contoured over at least two surfaces of the transmit coil defining a transmitter area of the receive coil for concentrating magnetic flux therefrom;

wherein;

the transmitting area is oriented to face the interface surface.

20. The inductive charging system of claim 19 wherein the electronic device is received on the interface surface, the receiving area is oriented to face the transmitting area.