Thin film light emitting diode
View Patent ↗Light emitting LEDs devices comprised of LED chips that emit light at a first wavelength, and a thin film layer over the LED chip that changes the color of the emitted light. For example, a blue LED chip can be used to produce white light. The thin film layer beneficially consists of a florescent material, such as a phosphor, and/or includes tin. The thin film layer is beneficially deposited using chemical vapor deposition.
1. A light emitting device, comprising:
an LED chip that emits light having a first wavelength, wherein the LED chip includes a first electrical contact and a second electrical contact;
a thin film layer formed over the LED chip, wherein the thin film layer interacts with the light to form light having a second wavelength, and wherein the thin film layer has an opening corresponding to the first electrical contact.
2. The device according to claim 1 , wherein the thin film layer comprises at least one of a fluorescent material, a tin-containing material, and a phosphor.
3. The device according to claim 1 , further comprising a passivation layer between the LED chip and the thin film layer.
4. The device according to claim 3 , wherein the passivation layer comprises at least one of Si, polymers, oxides and nitrides.
5. The device according to claim 3 , further comprising a second passivation layer over the thin film layer.
6. The device according to claim 3 , wherein the passivation layer is disposed over at least one of a side surface and a top surface of the LED chip.
7. The device according to claim 1 , wherein the thickness of the thin film layer is about 10 μm.
8. The device according to claim 1 , wherein the thin film layer is an integral element of the LED chip.
9. A light emitting device comprising:
an LED chip including a semiconductor structure having multi-layers that emits light having a first wavelength, wherein the LED chip includes a first electrical contact and a second electrical contact respectively located at opposite sides of the semiconductor structure;
a passivation layer formed over the LED chip; and
a thin film layer over the passivation layer, wherein the thin film layer interacts with the light to form light having a second wavelength, and wherein at least a portion of the passivation layer is in contact with the thin film layer.
10. The device according to claim 9 , wherein the LED chip is attached to a heat sink.
11. The device according to claim 9 , wherein the thin film layer is formed over the LED chip, and wherein the thickness of the thin film layer is substantially uniform.
12. The device according to claim 9 , wherein the thin film layer comprises at least one of a fluorescent material, a tin-containing material, and a phosphor.
13. The device according to claim 9 , wherein the thickness of the passivation layer is about 1000 Å.
14. The device according to claim 9 , further comprising a reflective layer over the semiconductor structure.
15. The device according to claim 1 , wherein the opening in the thin film layer exposes a top surface of the LED chip.
16. The device according to claim 1 , wherein the thickness of the thin film layer is substantially uniform over at least a portion of a top surface of the LED chip, a side surface of the LED chip, a side of the first electrical contact or a side of the second electrical contact.
17. The device according to claim 16 , wherein the thin film layer is configured to enhance the uniformity of the light having a second wavelength.
18. The device according to claim 1 , wherein the thickness of the thin film layer is substantially uniform over at least a portion of a top surface of the LED chip.
19. The device according to claim 1 , wherein the opening is configured to prevent the thin film layer from contacting a bonding wire bonded to the first electrical contact.
20. The device according to claim 1 , wherein the opening prevents the thin film layer from coming into contacting with the first electrical contact.
21. The device according to claim 1 , wherein the thin film layer is configured to expose the first electrical contact.
22. The device according to claim 1 , wherein the thin film layer has a second opening corresponding to the second electrical contact.
23. The device according to claim 22 further comprises a passivation layer between the LED chip and the thin film layer, the passivation layer having a first opening and a second opening, the first opening in the passivation layer corresponding to the first opening in the thin film layer and the second opening in the passivation layer corresponding to the second opening in the thin film layer, wherein the first and the second openings in the thin film layer and the passivation layer expose at least a portion of the first electrical contact and the second electrical contact, respectively.
24. The device according to claim 3 , wherein the passivation layer comprises an opening corresponding to the opening in the thin film layer.
25. The device according to claim 3 , wherein the opening in the passivation layer and the opening in the thin film layer expose the first electrical contact.
26. The device according to claim 3 , wherein the passivation layer is configured to prevent the thin film layer from coming into contact with the first electrical contact.
27. The device according to claim 3 , wherein at least a portion of the passivation layer prevents the thin film layer from coming into contact with the LED chip.
28. The device according to claim 3 , wherein the passivation layer is disposed on a side surface of the LED chip and extends to at least a portion of a top surface of the LED chip.
29. The device according to claim 9 , wherein the passivation layer comprises at least one of Si, polymers, oxides and nitrides.
30. The device according to claim 9 , further comprising a second passivation layer over the thin film layer.
31. The device according to claim 9 , wherein the passivation layer is configured to expose at least one of the first and the second electrical contacts.
32. The device according to claim 9 , wherein the passivation layer prevents the thin film layer from coming into contact with at least one of the first and the second electrical contacts.
33. The device according to claim 9 , wherein at least a portion of the passivation layer prevents the thin film layer from coming into contact with the LED chip.
34. The device according to claim 9 , wherein the passivation layer is disposed over at least one of a side surface and a top surface of the LED chip.
35. The device according to claim 9 , wherein the passivation layer is disposed on a side surface of the LED chip and extends to at least a portion of a top surface of the LED chip.
36. The device according to claim 11 , wherein the thin film layer is configured to enhance the uniformity of the light having a second wavelength.
37. A light emitting device comprising:
an LED chip that emits light having a first wavelength, wherein the LED chip includes a first electrical contact and a second electrical contact;
a passivation layer over the LED chip, the passivation layer having at least one first opening; and
a thin film layer formed over the passivation layer, the thin film layer having at least one second opening corresponding to the first opening, wherein the thin film layer interacts with the light to form light having a second wavelength, and wherein one of the electrical contacts is aligned with the first and second openings.