Low AC resistance conductor designs
View Patent ↗Described herein are improved configurations for providing a stranded printed circuit board trace comprising, a plurality of conductor layers, a plurality of individual conductor traces on each of the said conductor layers, and a plurality of vias for connecting individual conductor traces on different said conductor layers, the vias located on the outside edges of the stranded trace. The individual conductor traces of each layer may be routed from vias on one side of the stranded printed circuit board trace to vias on the other side in a substantially diagonal direction with respect to the axis of the stranded printed circuit board trace. In embodiments, the stranded printed circuit board trace configuration may be applied to a wireless power transfer system.
1. An inductor, comprising:
a plurality of conductor layers forming a part of a printed circuit board;
a plurality of conductor traces on at least two of the plurality of conductor layers; and
a plurality of vias that connect conductor traces on different ones of the plurality of conductor layers,
wherein each of the plurality of conductor traces is characterized by a cross-sectional dimension, and
wherein each of the plurality of conductor traces is routed along a path having a substantially similar design, and
wherein the path of at least one of the plurality of conductor traces on one conductor layer is linearly offset from the conductor path it is electrically connected to on at least one other conductor layer and wherein each of the plurality of conductor traces is formed, at least in part, of conductor material.
2. The inductor of claim 1 wherein the conductor traces comprise copper.
3. The inductor of claim 1 wherein the conductor traces comprise silver.
4. The inductor of claim 1 wherein the conductor traces comprise platinum.
5. The inductor of claim 1 wherein the conductor trace cross-sectional dimension is less than 200 micrometers.
6. The inductor of claim 1 wherein the conductor trace cross-sectional dimension is less than 100 micrometers.
7. The inductor of claim 1 wherein the conductor trace cross-sectional dimension is less than one skin depth of the conductor material at an operating frequency.
8. The inductor of claim 1 wherein the routed path of at least one conductor trace comprises a 90 degree bend.
9. The inductor of claim 1 wherein the path of at least one conductor trace comprises a bend with an angle less than 90 degrees.
10. The inductor of claim 1 wherein the path of at least one of the plurality of conductor traces comprises an arc.
11. The inductor of claim 1 , wherein at least one of the plurality of conductor traces on a layer form a stranded trace.
12. The inductor of claim 11 , wherein the ratio of the width of the stranded trace to a thickness of the plurality of conductor layers that form the inductor is greater than 1.
13. The inductor of claim 11 , wherein the ratio of the width of the stranded trace to a thickness of the plurality of conductor layers that form the inductor is greater than 4.
14. The inductor of claim 11 wherein an AC resistance of the stranded trace is less than twice the DC resistance of the stranded trace.
15. The inductor of claim 1 wherein a magnetic material resides within a loop formed by the stranded trace.
16. A wireless power source comprising:
an inductor, comprising:
a plurality of conductor layers forming a part of a printed circuit board;
a plurality of conductor traces on at least two of the plurality of conductor layers; and
a plurality of vias that connect conductor traces on different ones of the plurality of conductor layers,
wherein each of the plurality of conductor traces is characterized by a cross-sectional dimension, and
wherein each of the plurality of conductor traces is routed along a path having a substantially similar design, and
wherein the path of at least one of the plurality of conductor traces on one conductor layer is linearly offset from the conductor path it is electrically connected to on at least one other conductor layer.
17. The wireless power source of claim 16 , further comprising a power supply.
18. The wireless power source of claim 17 , wherein the inductor is driven with a substantially single frequency oscillating drive signal.
19. The wireless power source of claim 18 , wherein the frequency of the drive signal is greater than 10 kHz and less than 100 MHz.
20. The wireless power source of claim 17 , wherein the inductor is driven by a waveform generated in a processor.
21. The wireless power source of claim 16 , further comprising at least one high-Q capacitor to form a magnetic resonator.
22. A wireless power device comprising:
an inductor, comprising:
a plurality of conductor layers forming a part of a printed circuit board;
a plurality of conductor traces on at least two of the plurality of conductor layers; and
a plurality of vias that connect conductor traces on different ones of the plurality of conductor layers,
wherein each of the plurality of conductor traces is characterized by a cross-sectional dimension, and
wherein each of the plurality of conductor traces is routed along a path having a substantially similar design, and
wherein the path of at least one of the plurality of conductor traces on one conductor layer is linearly offset from the conductor path it is electrically connected to on at least one other conductor layer.
23. The wireless power device of claim 22 , further comprising a rectification circuit.
24. The wireless power device of claim 22 , further comprising at least one high-Q capacitor to form a magnetic resonator.
25. The wireless power device of claim 23 , wherein the output of the rectification circuit supplies power to a device or a battery.