Induction coil having a conductive winding formed on a surface of a molded substrate

• US 10,062,492 B2
• Filed: 04/18/2014
• Issued: 08/28/2018
• Est. Priority Date: 04/18/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wagman, Daniel C., Jol, Eric S., Kamei, Ibuki
• Primary Examiner(s): Chan, Tsz
• Application Number:
  US14/256,603
• Publication Number:
  US 20150302971A1
• Time in Patent Office: 1,593 Days
• Field of Search: 336200, 336232
• CPC Class Codes: B29C 45/14467 Joining articles or parts of a single article B29C45/14377, B29C45/14385, B29C45/14581, B29C45/14614 and B29C45/006 take precedence
• CPC Class Codes: B29C 45/14639 for obtaining an insulating effect, e.g. for electrical components
• CPC Class Codes: B29K 2105/16 Fillers
• CPC Class Codes: B29K 2995/0005 Conductive
• CPC Class Codes: B29L 2031/3481 Housings or casings incorporating or embedding electric or electronic elements
• CPC Class Codes: H01F 27/2804 Printed windings
• 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: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• 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 7/0042 characterised by the mechanical construction

Abstract

The following examples and embodiments are directed to an induction coil that can be used in a variety of applications, including, for example, induction charging systems. In one example, an induction coil is configured to couple an electrical field between a base device and a mobile device in an inductive charge system. The induction coil includes a coil substrate formed by a molding process. The induction coil also includes a shield element disposed within the coil substrate. The shield element may be formed within the coil substrate as part of the molding process. A conductive winding is also formed within a surface of the coil substrate. In some cases, the coil substrate is formed by an injection-molding process.

Claims

1. An induction coil assembly, comprising:

an electrically insulative coil substrate;

a shield element encapsulated within the electrically insulative coil substrate; and

an electrically conductive winding configured to couple an electrical field between a base device and a mobile device in an inductive charging system, the electrically conductive winding extending across an external surface of the electrically insulative coil substrate,

wherein the shield element extends beneath a larger portion of the external surface than the electrically conductive winding occupies.

2. The induction coil assembly of claim 1, wherein the electrically conductive winding is formed from a single conductive trace having a continuous spiral shape.

3. The induction coil assembly of claim 1, wherein the electrically insulative coil substrate is formed from a thermoplastic material that is doped with a conductive particulate.

4. The induction coil assembly of claim 1, wherein:

the electrically insulative coil substrate is formed from a thermoplastic material that is configured to be laser activated, and

the electrically conductive winding is formed by activating a region of the thermoplastic material and depositing a conductive coating on the region to form a solid conductive trace.

5. The induction coil assembly of claim 4, wherein the conductive coating includes a copper plating material.

6. The induction coil assembly of claim 1, wherein the external surface of the electrically insulative coil substrate having the electrically conductive winding formed thereon is contoured in shape.

7. The induction coil assembly of claim 1, wherein the external surface substantially conforms to a mating surface of the base device.

8. The induction coil assembly of claim 7, wherein the mating surface of the base device is an internal surface of a housing device.

9. The induction coil assembly of claim 1, wherein the shield element is an electromagnetic shield of the induction coil assembly.

10. The induction coil assembly of claim 1, further comprising:

a plurality of shield elements arranged in a circular pattern, wherein each shield element is formed within the electrically insulative coil substrate as part of an injection-molding process, and wherein each of the shield elements has semi-circle shape.

11. The induction coil assembly of claim 1, wherein the shield element is formed from a ferromagnetic material.

12. The induction coil assembly of claim 1, wherein the shield element is formed from an electrical steel laminate material.

13. The induction coil assembly of claim 1, wherein the shield element is configured to substantially shield electrical components from electromagnetic fields generated by the induction coil assembly.

14. The induction coil assembly of claim 1, wherein the induction coil is disposed within a housing of the base device.

15. The induction coil assembly of claim 1, wherein the induction coil is disposed within a housing of the mobile device.

16. An electronic device comprising:

a housing having a non-planar interface surface; and

an induction coil assembly positioned within the housing and having a non-planar shape that corresponds to the non-planar interface surface the induction coil assembly being configured to couple an electrical field between the electronic device and a separate device in an inductive charging system, the induction coil assembly comprising;

an electrically insulative coil substrate having a non-planar external surface;

a shield element encapsulated within the electrically insulative coil substrate; and

an induction coil comprising an electrically conductive winding extending across the non-planar external surface of the electrically insulative coil substrate.

17. The electronic device of claim 16, wherein:

the electronic device is a wearable device; and

the non-planar external surface of the electrically insulative coil substrate has a convex shape.

18. The electronic device of claim 16, wherein:

the electronic device is a base device that is configured to provide a charge for the separate device; and

the non-planar external surface has a concave shape.

19. The electronic device of claim 16, wherein the non-planar interface surface is configured to receive a mating interface surface of the separate device.

20. An induction coil assembly, comprising:

a coil substrate formed from a thermoplastic material; and

a shield element encapsulated within the coil substrate; and

an induction coil comprising a conductive winding formed on an external surface of the coil substrate, the induction coil configured to couple an electric field between a first device and a second device for the inductive transference of electrical energy,

wherein the shield element extends beneath a larger portion of the external surface than the conductive winding occupies.

21. The induction coil assembly of claim 20, wherein:

the induction coil assembly is positioned within a housing of the first device;

the housing has a non-planar surface; and

the external surface of the coil substrate has a shape that corresponds to the non-planar surface of the housing.

22. The induction coil of claim 21, wherein the first device is a base device that is configured to receive AC power and provide wireless charging to the second device.