Coil assembly

1. A coil assembly, comprising:

a connection substrate comprising a coil pad and an accommodating portion, the accommodating portion being adjacent to the coil pad and including a space; and

a coil portion comprising a spiral wiring and end portions bonded to the coil pad, at least a portion of the coil portion being in the accommodating portion,

wherein the coil pad comprises a first coil pad inside the coil portion and a second coil pad outside the coil portion,

wherein one of the end portions disposed at a central side of the coil portion is connected to the first coil pad, and another one of the end portions disposed at an outer side of the coil portion is connected to the second coil pad,

wherein each of the end portions comprises a first section bonded to the coil pad and a second section extending from each of both sides of the first section and being at least partially in the space, and

wherein the end portions are sections disposed to oppose the coil pad and the accommodating portion.

2. The coil assembly of claim 1 , wherein the first section has a thickness that is less than a thickness of the second section.

3. The coil assembly of claim 1 , wherein the accommodating portion is on opposing sides of the coil pad.

4. The coil assembly of claim 1 , wherein the accommodating portion includes through-hole passing through the connection substrate.

5. The coil assembly of claim 1 , wherein the connection substrate further comprises:

a connection pad; and

a connection wiring connecting the connection pad to the coil pad.

6. The coil assembly of claim 5 , wherein

the coil portion further comprises an insertion groove being opposite to the connection wiring, and

at least a portion of the connection wiring is in the insertion groove.

7. The coil assembly of claim 1 , wherein

the coil portion further comprises coil strands, the coil strands being in parallel and spirally wound, and

the coil strands are electrically connected to each other.

8. The coil assembly of claim 7 , wherein

each of the coil strands comprises a conductor line, an insulating coating surrounding the conductor line, and an adhesive layer outside the insulating coating, and

the coil strands are integrated by the adhesive layer.

9. The coil assembly of claim 7 , wherein the coil portion further comprises a stepped portion along a pressure line, which is in a radial direction of the coil portion.

10. The coil assembly of claim 7 , wherein the coil strands are on a same plane.

11. The coil assembly of claim 1 , further comprising:

a supporting substrate to which the coil portion is attached,

wherein the supporting substrate comprises a substrate combining portion to which the connection substrate is bonded.

12. The coil assembly of claim 11 , wherein the end portions are on the substrate combining portion.

13. The coil assembly of claim 1 , wherein the coil portion is configured to perform any one of transmission and reception of electric power for wireless charging, a radio frequency identification (RFID) function, a near field communication (NFC) function, and a magnetic security transmission (MST) function.

14. A coil assembly, comprising:

a connection substrate comprising a coil pad and an accommodating portion, the accommodating portion being adjacent to the coil pad and including a space; and

a coil portion comprising coil strands, end portion, and at least one stepped portion, the coil strands being in parallel and being in a spiral shape in a single layer, the end portions bonded to the coil pad, and the at least one stepped portion along a pressure line, which is in a radial direction of the coil portion,

wherein at least a portion of the coil portion is in the accommodating portion, wherein the coil pad comprises a first coil pad inside the coil portion and a second coil pad outside the coil portion,

wherein one of the end portions disposed at a central side of the coil portion is connected to the first coil pad, and another one of the end portions disposed at an outer side of the coil portion is connected to the second coil pad,

wherein each of the end portions comprises a first section bonded to the coil pad and a second section extending from each of both sides of the first section and being at least partially in the space, and

wherein the end portions are sections disposed to oppose the coil pad and the accommodating portion.

15. A coil assembly, comprising:

a connection substrate comprising a coil pad, a connection wiring extended from the coil pad and an accommodating portion being adjacent to the coil pad and including a space; and

a coil portion comprising coil strands disposed in parallel to form a spiral shape, end portions bonded to the coil pad, and an insertion groove disposed in a position opposing the connection wiring,

wherein at least a portion of the connection wiring is disposed in the insertion groove,

wherein at least a portion of the coil portion is disposed in the accommodating portion,

wherein the coil pad comprises a first coil pad inside the coil portion and a second coil pad outside the coil portion,

wherein one of the end portions disposed at a central side of the coil portion is connected to the first coil pad, and another one of the end portions disposed at an outer side of the coil portion is connected to the second coil pad,

wherein each of the end portions comprises a first section bonded to the coil pad and a second section extending from each of both sides of the first section and being at least partially in the space, and

wherein the end portions are sections disposed to oppose the coil pad and the accommodating portion.

16. The coil assembly of claim 15 , wherein the insertion groove is in the coil strands and extends in a radial direction of the coil portion.

17. The coil assembly of claim 15 , wherein a thickness of the insertion groove is substantially equal to a thickness of the connection wiring.

18. A coil assembly, comprising:

a flat spiral-shaped coil member composed of coil strands, the flat spiral-shaped coil member including an insertion groove defined thereon and extending across the flat spiral-shaped coil member, the flat spiral-shaped coil member including an end portion bonded to a coil pad; and

a connection substrate comprising,

a connection pad configured to be connected to an external component,

the coil pad including,

a first coil pad being inside the flat spiral-shaped coil member, being at a central side of the flat spiral-shaped coil member, and connected to a first end portion of the flat spiral-shaped coil member, and

a second coil pad being outside the flat spiral-shaped coil member, being at an outer side of the flat spiral-shaped coil member, and connected to a second end portion of the flat spiral-shaped coil member,

a first connection wiring connecting the first coil pad to the connection pad, and being in the insertion groove,

a second connection wiring connecting the second coil pad to the connection pad, and

an accommodating portion being adjacent to a corresponding one of the first coil pad and the second coil pad, and including a space,

wherein each of the first end portion and the second end portion includes a first section bonded to the corresponding one of the first coil pad and the second coil pad and a second section extending from each of both sides of the first section and being at least partially in the space, and

wherein the first and second end portions are sections disposed to oppose the first coil pad, the second coil pad, and the accommodating portion.

19. The coil assembly of claim 18 , wherein a thickness of the insertion groove is substantially equal to a thickness of the first connection wiring.

20. The coil assembly of claim 18 , wherein the insertion groove is defined by a portion of the coil strands having a reduced thickness.

21. The coil assembly of claim 18 , wherein a thickness of the at the flat spiral-shaped coil member in a region of the insertion groove is less than a thickness of the flat spiral-shaped coil member in a region adjacent to the insertion groove.