Wireless charging pad and wireless charging apparatus

1. A wireless charging pad comprising:

a ferrite plate;

a coil disposed on the ferrite plate; and

a resonance tank comprising a flat type capacitor, the flat type capacitor being configured to reduce an impedance of the coil,

wherein the flat type capacitor comprises:

a first capacitor that is connected electrically in series with the coil, and

a second capacitor that is connected electrically in series with the first capacitor, and

wherein the first capacitor and the second capacitor have a flat shape and are arranged on a common plane.

2. The wireless charging pad of claim 1 , wherein the flat type capacitor is disposed vertically below the ferrite plate.

3. The wireless charging pad of claim 2 , wherein the ferrite plate defines a hole that penetrates a top surface of the ferrite plate and a bottom surface of the ferrite plate, and

wherein the flat type capacitor is electrically connected with the coil by a first wire inserted through the hole.

4. The wireless charging pad of claim 3 , wherein the ferrite plate defines a groove at the bottom surface, and

wherein the flat type capacitor is electrically connected with an external device by a second wire disposed in the groove.

5. The wireless charging pad of claim 4 , wherein:

the first capacitor is connected electrically in series with the coil by the first wire; and

the second capacitor is connected electrically in series with the first capacitor and connected with the external device by the second wire.

6. The wireless charging pad of claim 2 , further comprising:

an aluminum plate disposed vertically below the ferrite plate; and

an insulation sheet disposed between the aluminum plate and the flat type capacitor.

7. The wireless charging pad of claim 1 , wherein the ferrite plate comprises a plurality of ferrite plates, and

wherein the flat type capacitor is disposed between any two of the plurality of ferrite plates.

8. The wireless charging pad of claim 1 , further comprising a case that is disposed below the first capacitor and the second capacitor and has a surface defining the common plane.

9. The wireless charging pad of claim 7 , wherein the coil comprises a plurality of sub-coils,

wherein the flat type capacitor comprises a plurality of capacitors, and

wherein the plurality of sub-coils and the plurality of capacitors are alternately connected electrically in series in which one capacitor of the plurality of capacitors is connected between two sub-coils of the plurality of sub-coils.

10. The wireless charging pad of claim 7 , wherein each of the plurality of ferrite plates has:

two straight sides, each straight side extending from a first end to a second end;

a first arc side that connects the first ends of the two straight sides and that has a first radius of curvature; and

a second arc side that connects the second ends of the two straight sides and that has a second radius of curvature greater than the first radius of curvature.

11. A wireless charging pad comprising:

a first ferrite plate disposed at a first layer of the wireless charging pad;

a second ferrite plate disposed at a second layer of the wireless charging pad, the second ferrite plate being disposed vertically above or below the first ferrite plate; and

a coil that is wound around the first ferrite plate and that is disposed vertically above or below the second ferrite plate,

wherein the second ferrite plate comprises a plurality of sub-magnetic bodies that are arranged on a common plane and spaced apart from one another by a separation distance to thereby define an accommodation space between the plurality of sub-magnetic bodies.

12. The wireless charging pad of claim 11 , wherein at least a part of the second ferrite plate is in contact with at least a part of the first ferrite plate.

13. The wireless charging pad of claim 12 , wherein the first ferrite plate and the second ferrite plate are configured to define a continuous magnetic path passing the first ferrite plate and the second ferrite plate.

14. The wireless charging pad of claim 11 , wherein the accommodation space is configured to accommodate an electronic component.

15. The wireless charging pad of claim 14 , wherein at least a part of the first ferrite plate overlaps with the accommodation space.

16. The wireless charging pad of claim 14 , wherein the coil is disposed at the first layer.

17. The wireless charging pad of claim 16 , wherein the electronic component is disposed at the second layer, and

wherein the electronic component comprises at least one of a converter, an inverter, a rectifier, or a resonance tank.

18. The wireless charging pad of claim 14 ,

wherein the coil comprises a lead-in wire and a lead-out wire that are disposed in a gap defined between the plurality of sub-magnetic bodies.

19. The wireless charging pad of claim 18 , wherein the second ferrite plate is configured to, based on the electronic component being disposed in the accommodation space of the second ferrite plate, define a first internal impedance of the lead-in wire and the lead-out wire to be less than a second internal impedance of the lead-in wire and the lead-out wire defined without the electronic component disposed in the accommodation space.

20. The wireless charging pad of claim 11 , further comprising an insulator disposed between the first ferrite plate and the coil.