INDUCTION COIL HAVING A CONDUCTIVE WINDING FORMED ON A SURFACE OF A MOLDED SUBSTRATE

• US 20150302971A1
• Filed: 04/18/2014
• Published: 10/22/2015
• Est. Priority Date: 04/18/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Jol, Eric S., Kamei, Ibuki, Wagman, Daniel C.
• Granted Patent: US 10,062,492 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 configured to couple an electrical field between a base device and a mobile device in an inductive charging system, the induction coil comprising:

a coil substrate formed by a molding process;

a shield element disposed within the coil substrate, the shield element formed within the coil substrate as part of the molding process; and

a conductive winding formed on a surface of the coil substrate.

2. The induction coil of claim 1, wherein the coil substrate is formed by an injection-molding process.

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

4. The induction coil of claim 1, wherein:

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

the 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 of claim 4, wherein the conductive coating includes a copper plating material.

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

7. The induction coil of claim 1, wherein the induction coil has an external surface that is contoured in shape, and wherein the external surface substantially conforms to a mating surface of the base device.

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

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

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

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

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

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

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

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

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

16. A method of forming a molded induction coil, the method comprising:

inserting a shield element into a cavity of a mold;

forming a coil substrate around the shield element; and

forming one or more winding in a surface of the coil substrate.

17. The method of claim 16, wherein the molded induction coil is configured to couple an electrical field between a base device and a mobile device in an inductive charging system.

18. The method of claim 16, wherein the coil substrate is formed using an injection-molding process comprising:

injecting the a molten material into the cavity of the mold;

immersing the shield element in the molten material; and

curing the molten material to form the coil substrate.

19. The method of claim 16, wherein the coil substrate is formed from a thermoplastic material that is doped with a conductive particulate.

20. The method of claim 16, wherein forming the conductive winding further comprises:

activating a region of the surface of the coil substrate to create a treated region; and

depositing a conductive material on the treated region to form a solid conductive trace.

21. The method of claim 20, wherein activating the region of the surface of the coil substrate is performed using a laser beam that is focused on the surface of the coil substrate.

22. The method of claim 16, further comprising:

installing the molded induction coil into a housing of a mobile device;

charging a battery of the mobile device using the molded induction coil to couple electrical power between the mobile device and a base device.