High Current, Low Equivalent Series Resistance Printed Circuit Board Coil for Power Transfer Application

• US 20150115732A1
• Filed: 12/30/2014
• Published: 04/30/2015
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zabaco, Jorge
• Granted Patent: US 9,818,527 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/002 Details of via holes for interconnecting the layers
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• 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 50/12 of the resonant type
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An apparatus for a multilayer printed circuit board (PCB) coil, comprising: a first coil layer of a PCB; a plurality of vias coupled to and distributed to cover substantially the surface of the first coil layer within the PCB; and a second coil layer of the PCB and coupled to the vias to cover substantially the surface of the second coil layer, wherein the vias are positioned between the first coil layer and the second coil layer and enable substantially high current and low equivalent series resistance (ESR) for the multilayer PCB coil.

Claims

1. An apparatus for a multilayer printed circuit board (PCB) coil, comprising:

a first coil layer of a PCB;

a plurality of vias coupled to and distributed to cover substantially the surface of the first coil layer within the PCB; and

a second coil layer of the PCB and coupled to the vias to cover substantially the surface of the second coil layer,

wherein the vias are positioned between the first coil layer and the second coil layer and enable substantially high current and low equivalent series resistance (ESR) for the multilayer PCB coil.

2. The apparatus of claim 1 further comprising one or more other circuit components integrated with the first coil layer and the second coil layer on the PCB.

3. The apparatus of claim 1, wherein the multilayer PCB coil is a component used in a wireless charging device.

4. The apparatus of claim 1, wherein the multilayer PCB coil is a component used in a near-field transmission device.

5. The apparatus of claim 1, wherein the vias have a cylindrical shape and are vertical with respect to the surfaces of the first coil layer and the second coil layer.

6. An apparatus for power transfer, comprising:

a multilayer printed circuit board (PCB) coil comprising;

a first coil layer of a PCB;

a plurality of vias coupled to and distributed to cover substantially the surface of the first coil layer within the PCB; and

a second coil layer of the PCB and coupled to the vias to cover substantially the surface of the second coil layer,

wherein the first coil layer, the vias, and the second coil layer are integrated within the PCB,

wherein the multilayer PCB coil is configured to transfer energy with an electric coil using resonant inductive coupling when the multilayer PCB coil is coupled to the electric coil, and

wherein resonant inductive coupling is implemented by tuning the multilayer PCB coil and the electric coil to substantially a same frequency.

7. The apparatus of claim 6, further comprising one or more other circuit components integrated with the first coil layer and the second coil layer on the PCB.

8. The apparatus of claim 6, wherein the multilayer PCB coil is a component used in a wireless charging device.

9. The apparatus of claim 6, wherein the multilayer PCB coil is a component used in a near-field transmission device.

10. The apparatus of claim 6, wherein the vias have a cylindrical shape and are vertical with respect to the surfaces of the first coil layer and the second coil layer.

11. The apparatus of claim 6, wherein the first coil layer and the second coil layer are traces within the PCB, and wherein a trace of the second coil layer mirrors a trace of the first coil layer.

12. The apparatus of claim 11, wherein the thickness of the trace of the first coil layer and the thickness of the trace of the second coil layer determines an equivalent series resistance (ESR) for the multilayer PCB coil.

13. The apparatus of claim 12, wherein the ESR for the multilayer PCB coil determines the energy transfer between the multilayer PCB coil and the electric coil using resonant inductive coupling.

14. The apparatus of claim 12, wherein the thickness of the trace of the first coil layer and the thickness of the trace of the second coil layer are substantially the same.

15. The apparatus of claim 6, wherein the vias electrically connect the first coil layer with the second coil layer, and wherein a ferrite core material is not positioned between the first coil layer and the second coil layer.

16. A method for wireless power transfer, comprising:

resonating a multilayer printed circuit board (PCB) coil at a first frequency; and

receiving a power transfer at the multilayer PCB coil via resonant inductive coupling from a transmitting coil that resonates at a second frequency,

wherein the first frequency and second frequency are substantially the same,

wherein the PCB coil comprises;

a first coil layer of a PCB formed using a PCB winding trace;

a plurality of vias coupled to and distributed along the PCB winding trace; and

a second coil layer of the PCB formed using a second PCB winding trace,

wherein the first coil layer, the vias, and the second coil layer are integrated within the PCB, and

wherein the first coil layer and the second coil layer are joined together using the vias.

17. The method of claim 16, wherein the first PCB winding trace forms a coil pattern within the first coil layer, wherein the second PCB winding trace forms a second coil pattern within the second coil layer, and wherein the coil pattern and the second coil pattern are substantially the same.

18. The method of claim 16, wherein the multilayer PCB coil is located within a radio-frequency identification (RFID) device.

19. The method of claim 18, wherein the RFID device further comprises one or more other circuit components integrated with the first coil layer and the second coil layer on the PCB.

20. The method of claim 16, wherein the first PCB winding trace has a thickness determined to meet a desired equivalent series resistance (ESR) for the multilayer PCB coil.

21. The method of claim 20, wherein the desired ESR for the multilayer PCB coil determines the energy transfer between the multilayer PCB coil and the transmitting coil using resonant inductive coupling.

22. The method of claim 16, wherein the vias electrically couple the first coil layer with the second coil layer, and wherein a number of the vias distributed along the length of the PCB winding trace is determined to meet a desired current flow for the multilayer PCB coil.

23. The method of claim 16, wherein at least some of the vias have different sizes that affect current flow and series resistance in the multilayer PCB coil.

24. The method of claim 16, wherein the vias have a cylindrical shape and are vertical with respect to the surfaces of the first coil layer and the second coil layer.

25. The method of claim 16, wherein the multilayer PCB coil is a component used in a wireless charging application, and wherein a ferrite core material is not located between the first coil layer and the second coil layer.