PRINTED CIRCUIT BOARD COIL

• US 20090085706A1
• Filed: 09/24/2008
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Duckworth, Paul, Baarman, David W., Schwannecke, Joshua K., Wahl, Richard A., Guthrie, Warren E.
• Granted Patent: US 7,973,635 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/34 Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
• 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 5/003 Printed circuit coils
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/097 Alternating conductors, e.g. alternating different shaped pads, twisted pairs; Alternating components

Abstract

A multilayer printed circuit board (“PCB”) coil that simulates a coil formed from litz wire. The PCB includes a plurality of alternating conductor and insulating layers interconnected to cooperatively form the coil. Each conductor layer includes a trace that follows the desired coil shape and is divided into a plurality of discrete conductor segments. The segments are electrically connected across layers to provide a plurality of current flow paths (or filaments) that undulate between the layers in a regular, repeating pattern. The coil may be configured so that each filament spends a substantially equal amount of time in proximity to the paired coil and therefore contributes substantially equally to the self or mutual inductance of the coil. Each conductor layer may include a plurality of associated traces and intralayer connector that interconnected so that each filament undulates not only upwardly/downwardly, but also inwardly/outwardly in a regular, repeating pattern.

Claims

1. A printed circuit board coil for use with a paired coil comprising:

a substrate;

a plurality of conductor layers, each conductor layer including a plurality of discrete coil segments; and

a plurality of interlayer connectors electrically interconnecting coil segments of different layers to define a plurality of discrete filaments, each of said filaments following substantially identical, but offset, undulations through said plurality of layers.

2. The printed circuit board of claim 1 wherein each of said filaments follows substantially identical, but offset, regular, repeating undulations through said plurality of layers.

3. The printed circuit board of claim 1 wherein said coil is paired with a second coil;

and

wherein said segments and said interlayer connectors are configured so that each filament spends a substantially equal amount of time in proximity to the paired coil, whereby the printed circuit board coil simulates a coil of litz wire.

4. The printed circuit board coil of claim 1 further including an insulator layer disposed between adjacent pairs of said conductor layers.

5. The printed circuit board coil of claim 1 wherein each of said plurality of conductor layers includes a spiral trace.

6. The printed circuit board coil of claim 5 wherein each of said traces includes an interchange, said interlayer connectors including a plurality of vias selectively routed through said interchanges.

7. The printed circuit board coil of claim 1 wherein each said spiral trace includes an innermost end and an outermost end, each of said segments including an inner end toward said innermost end of said spiral trace and an outer end toward said outermost end of said spiral trace;

and

wherein each of said filaments is defined by electrically connecting said inner end of one of said segments with said outer end of another of said segments in a continuous chain from said outermost end of said trace to said innermost end of said trace.

8. The printed circuit board coil of claim 1 wherein said plurality of segments defines a first spiral trace and a second spiral trace on each conductor layer;

and

further including a plurality of intralayer connectors for electrically connecting said segments from said first spiral trace with said segments of said second spiral trace within a single one of said conductor layers, said interlayer connectors and said intralayer connectors cooperatively defining said filaments following substantially identical, but offset, undulations within each of said layers and through each of said plurality of layers.

9. The printed circuit board coil of claim 1 wherein a first one of said conductor layers includes a spiral trace having a plurality of loops and wherein each segment of said trace of said first conductor layer is spaced apart from said segments of any adjacent loops of said first conductor layer to define a space;

and

wherein a second one of said conductor layers includes a spiral trace having a plurality of loops and wherein each segment of said trace of said second conductor layer is positioned to overlap said space of said first conductor layer.

10. A printed circuit board assembly comprising:

an insulative substrate;

a first conductor layer disposed on said substrate, said first conductor layer including a first trace having a plurality of discrete conductor segments;

a second conductor layer disposed on said substrate on a side opposite said first conductor layer, said second conductor layer including a second trace having a plurality of discrete conductor segments; and

a plurality of interlayer connectors interconnecting said segments of said first layer with said segments of said second in a predetermined pattern, wherein said interconnected segments define at least two filaments that undulate in a predetermined pattern between said first conductor layer and said second conductor layer.

11. The printed circuit board coil assembly of claim 10 further including:

a second insulative substrate positioned adjacent said first insulative substrate;

a third conductor layer disposed on said second substrate, said third conductor layer having a third trace including a plurality of discrete conductor segments;

a fourth conductor layer disposed on said second substrate on a side opposite said third conductor layer, said fourth conductor layer including a fourth trace having a plurality of discrete conductor segments; and

a plurality of interlayer connectors electrically interconnecting said segments of said first layer, said segments of said second layer, said segments of said third layer and said segments of said fourth layer in a predetermined pattern, wherein said interconnected segments define at least two filaments that undulate in a predetermined pattern between said first conductor layer, said second conductor layer, said third conductor layer and said fourth conductor layer.

12. The printed circuit board coil assembly of claim 10 wherein said first conductor layer includes a second trace having a plurality of discrete conductor segments;

and

further including a plurality of intralayer connectors electrically connecting said segments of said first trace with said segments of said third trace, whereby said filaments undulate in a predetermined pattern between said first conductor layer and said second conductor layer and between said first trace and said third trace.

13. The printed circuit board coil assembly of claim 12 wherein said second conductor layer includes a fourth trace having a plurality of conductor segments;

and

further including a plurality of intralayer connectors electrically connecting said segments of said second trace with said segments of said fourth trace, whereby said filaments undulate in a predetermined pattern between said first conductor layer and said second conductor layer and between said first trace and said third trace and between said second trace and said fourth trace.

14. The printed circuit board coil assembly of claim 10 wherein said filaments follow substantially parallel, but offset, paths undulating about said coil in a regular, repeating pattern.

15. The printed circuit board coil assembly of claim 10 wherein the coil has an innermost end and an outermost end;

each of said segments of said first trace having an inner end and an outer end, each of said segments of said second trace having an inner end and an outer end, each of said filaments being defined by a plurality of said segments interconnected by electrically connecting an inner end of one of said segments with an outer end of another of said segments in a continuous chain from said outer end of said coil to said inner end of said coil.

16. A multilayer electromagnetic coil for a wireless power connection comprising:

a first conductor layer having a plurality of discrete conductor segments;

a second conductor layer disposed adjacent to said first conductor layer, said second conductor layer including a plurality of discrete conductor segments; and

a plurality of connectors interconnecting said segments of said first layer with said segments of said second layer in a predetermined pattern, wherein said interconnected segments define at least two filaments that undulate in a predetermined pattern between said first conductor layer and said second conductor layer.

17. The multilayer coil of claim 16 wherein said segments and said connectors are arranged such that each of said filaments are substantially uniformly distributed throughout the coil, whereby each of said filaments contributes substantially equally to an inductance of the coil.

18. The multilayer coil of claim 16 further including a third conductor layer disposed adjacent to said second conductor layer, said third conductor layer including a plurality of discrete conductor segments;

and

said plurality of connectors interconnecting said segments of said first conductor layer, said second conductor layer and said third conductor layer in a predetermined pattern, wherein said interconnected segments define at least three filaments that undulate in a predetermined pattern through said first conductor layer, said second conductor layer and said third conductor layer, whereby each of said filaments contributes substantially equally to an inductance of the coil.

19. The multilayer coil of claim 16 in combination with a second inductive coil, said second inductive coil being inductive coupled with the coil, wherein said segments and said connectors are arranged such that each of said filaments are substantially uniformly distributed throughout the coil, whereby each of said filaments receives substantially uniform amounts of magnetic flux from said second coil.

20. The multilayer coil of claim 16 in combination with a second inductive coil, said second inductive coil being inductive coupled with the coil;

and

further including a third conductor layer disposed adjacent to said second conductor layer, said third conductor layer including a plurality of discrete conductor segments, said plurality of connectors interconnecting said segments of said first conductor layer, said second conductor layer and said third conductor layer in a predetermined pattern, wherein said interconnected segments define at least three filaments that undulate in a predetermined pattern through said first conductor layer, said second conductor layer and said third conductor layer, whereby each of said filaments receives substantially uniform amounts of magnetic flux from said second coil.

21. The multilayer coil of claim 16 wherein said conductor segments of said first layer define a first traces and a second trace, and

wherein said plurality of connectors interconnect said segments of said first trace and said second trace with said segments of said second layer in a predetermined pattern, wherein said interconnected segments define at least two filaments that undulate in a predetermined pattern between said first trace of said first conductor layer, said second trace of said first conductor layer and said second conductor layer.

22. The multilayer coil of claim 16 wherein both of said first and second conductive layers are equal average distance from said paired coil.

23. The printed circuit board of claim 16 wherein each of said first and second conductive layers transmit or receive a uniform amount of flux.

24. A multilayer electromagnetic coil for a wireless power connection comprising:

a first conductor layer having a first conductor segment and a second conductor segment;

a second conductor layer disposed adjacent to said first conductor layer, said second conductor layer including a first conductor segment, a second conductor segment and a third conductor segment;

a third conductor layer disposed adjacent to said second conductor layer, said third conductor layer including a first conductor segment, a second conductor segment and a third conductor segment;

a fourth conductor layer disposed adjacent to said third conductor layer, said fourth conductor layer including a first conductor segment and a second conductor segment;

a first interchange interconnecting said first segment of said first conductive layer with said second segment of said second conductive layer;

a second interchange interconnecting said second segment of said first conductive layer with said first segment of said second conductive layer;

a third interchange interconnecting said first segment of said third conductive layer with said second segment of said fourth conductive layer;

a fourth interchange interconnecting said second segment of said third conductive layer with said first segment of said fourth conductive layer;

a fifth interchange interconnecting said second segment of said second conductive layer with said third segment of said third conductive layer;

a sixth interchange interconnecting said third segment of said second conductive layer with said second segment of said third conductive layer.

25. The multilayer electromagnetic coil of claim 24 wherein said second segment of said first conductive layer and said second segment of said fourth conductive layer each include a plurality of voids that keep said fifth interchange and said sixth interchange from interconnecting with said second segment of said first conductive layer and said second segment of said fourth conductive layer.

26. The multilayer electromagnetic coil of claim 24 wherein said first conductive layer, said second conductive layer, said third conductive layer, and said fourth conductive layer are stacked on top of one another.

27. The multilayer electromagnetic coil of claim 24 wherein each of said conductive layers are equal average distance from a paired coil.

28. The multilayer electromagnetic coil of claim 24 wherein each of said conductive layers transmit or receive a uniform amount of flux.