Light emitting device having cantilever electrode, LED display panel and LED display apparatus having the same

1. A light emitting device, comprising:

at least one LED stack configured to emit light;

electrode pads disposed on the at least one LED stack and electrically connected to the at least one LED stack; and

cantilever electrodes disposed on the electrode pads and electrically connected to the electrode pads, respectively,

wherein each of the cantilever electrodes has a fixed edge that is fixed to one of the electrode pads and a free standing edge that is spaced apart from the one of the electrode pads.

2. The light emitting device of claim 1 , wherein

the free standing edge of the cantilever electrode is bent in a direction away from the at least one LED stack.

3. The light emitting device of claim 1 , wherein the cantilever electrode includes at least two metal layers having different thermal expansion coefficients from each other.

4. The light emitting device of claim 1 , wherein:

the at least one LED stack comprises:

a first LED stack, a second LED stack, and a third LED stack;

a first bonding layer interposed between the first LED stack and the second LED stack; and

a second bonding layer interposed between the second LED stack and the third LED stack;

the first, second, and third LED stacks are configured to emit light having different wavelengths; and

the electrode pads are electrically connected to the first, second, and third LED stacks to individually drive the first, second, and third LED stacks.

5. The light emitting device of claim 1 , wherein the light emitting device has a width of about 10 μm or less.

6. A display panel, comprising:

a circuit board having pads;

light emitting devices electrically connected to the pads and arranged on the circuit board; and

an adhesive layer disposed between the circuit board and the light emitting devices to adhere the circuit board and the light emitting devices, wherein:

each of the light emitting devices comprises:

at least one LED stack configured to emit light;

electrode pads disposed on the at least one LED stack and electrically connected to the at least one LED stack; and

cantilever electrodes disposed on the electrode pads and electrically connected to the electrode pads, respectively;

each of the cantilever electrodes has a fixed edge that is fixed to one of the electrode pads and a free standing edge that is spaced from the one of the electrode pads; and

the free standing edge is electrically connected to one of the pads of the circuit board.

7. The display panel of claim 6 , wherein the light emitting devices are disposed at a pitch of about 50 μm or less.

8. The display panel of claim 6 , wherein the light emitting devices are disposed at a pitch of about 10 μm or less.

9. The display panel of claim 6 , wherein at least one free standing edge of the cantilever electrodes extends outwardly beyond an area of the at least one LED stack.

10. The display panel of claim 6 , wherein the cantilever electrode includes at least two metal layers having different thermal expansion coefficients from each other.

11. The display panel of claim 10 , wherein the metal layers include at least one of Ni, Co, Cu, Ti, Al, Ti, and Pt.

12. The display panel of claim 6 , wherein:

the at least one LED stack comprises:

a first LED stack, a second LED stack, and a third LED stack;

a first bonding layer interposed between the first LED stack and the second LED stack; and

a second bonding layer interposed between the second LED stack and the third LED stack;

the first, second, and third LED stacks are configured emit light having different wavelengths; and

the electrode pads are electrically connected to the first, second, and third LED stacks to individually drive the first, second, and third LED stacks.

13. The display panel of claim 12 , wherein the light emitting devices are configured to emit light generated from the first, second, and third LED stacks through the third LED stack.

14. The display panel of claim 13 , wherein the third LED stack does not include a growth substrate.

15. The display panel of claim 12 , wherein the adhesive layer partially covers a side surface of the light emitting device.

16. The display panel of claim 15 , wherein the adhesive layer includes a curable resin.

17. A display apparatus, comprising:

a display panel comprising:

a circuit board having pads;

light emitting devices electrically connected to the pads and arranged on the circuit board; and

an adhesive layer disposed between the circuit board and the light emitting devices to adhere the circuit board and the light emitting devices, wherein:

each of the light emitting devices comprises:

at least one LED stack configured to emit light;

electrode pads disposed on the at least one LED stack and electrically connected to the at least one LED stack; and

cantilever electrodes disposed on the electrode pads and electrically connected to the electrode pads, respectively;

each of the cantilever electrodes has a fixed edge that is fixed to one of the electrode pads and a free standing edge that is spaced from the one of the electrode pads; and

the free standing edge is electrically connected to one of the pads of the circuit board.

18. The display apparatus of claim 17 , wherein the light emitting devices are disposed at a pitch of about 10 μm or less.

19. The display apparatus of claim 17 , wherein each of the cantilever electrodes includes at least two metal layers having different thermal expansion coefficients from each other.

20. The display apparatus of claim 17 , wherein:

each of the light emitting devices includes a first LED stack, a second LED stack, and a third LED stack;

the first, second, and third LED stacks are configured to emit light having different wavelengths; and

the light emitting devices are configured to emit light generated from the first, second, and third LED stacks through the third LED stack.