HIGH-POWER WHITE LEDS AND MANUFACTURING METHOD THEREOF

• US 20110102883A1
• Filed: 01/10/2011
• Published: 05/05/2011
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Gu, Yimin, Narendran, Nadarajah
• Granted Patent: US 8,031,393 B2
• Time in Patent Office: Days
• US Class Current: 359/326
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light emitting apparatus has a radiation source for emitting short wavelength radiation. A down conversion material receives and down converts at least some of the short wavelength radiation emitted by the radiation source and back transfers a portion of the received and down converted radiation. An optic device adjacent the down conversion material at least partially surrounds the radiation source. The optic device is configured to extract at least some of the back transferred radiation. A sealant substantially seals a space between the radiation source and the optic device.

Claims

1. A light emitting apparatus comprising:

an optic device having a top surface, a bottom surface, and at least one substantially transparent sidewall extending between the top surface and the bottom surface;

a radiation source for emitting short wavelength radiation, the radiation source disposed adjacent the bottom surface of the optic device;

a down conversion material, disposed on the top surface of the optic device and extending from the at least one transparent sidewall, receiving and down converting at least some of the short wavelength radiation emitted by the radiation source and back transferring a portion of the received and down converted radiation;

the optic device disposed between the down conversion material and the radiation source and configured to pass radiation back-transferred from the down conversion material outside of the optic device through the at least one substantially transparent sidewall;

a first reflective surface at least partially surrounding the optic device for reflecting at least some of the radiation extracted from the optic device through the at least one substantially transparent sidewall; and

a second reflective surface at least partially surrounding the radiation source for reflecting at least some of the radiation emitted by the radiation source toward the down conversion material, an end of the second reflective surface extending from a bottom of the first reflective surface.

2. The light emitting apparatus of claim 1, further comprising a well adjacent the optic device, the radiation source being disposed in the well.

3. The light emitting apparatus of claim 2, wherein the second reflective surface forms a portion of the well.

4. The light emitting apparatus of claim 1, wherein the second reflective surface is adjacent the first reflective surface.

5. The light emitting apparatus of claim 1, wherein the first reflective surface and the second reflective surface are formed on a support structure.

6. The light emitting apparatus claim 5, wherein the radiation source is disposed on the support structure.

7. The light emitting apparatus of claim 6, wherein the support structure is a heat sink.

8. The light emitting apparatus of claim 1, further comprising a sealant disposed at least in a space between the radiation source and the optic device.

9. The light emitting apparatus of claim 1, further comprising a sealant disposed at least in a space between the second reflective surface and the radiation source.

10. The light emitting apparatus of claim 1, wherein the first reflective surface comprises a reflective cup having at least one radius of curvature.

11. The light emitting apparatus of claim 1, wherein the first reflective surface comprises a reflective cup having at least a first radius of curvature and a second radius of curvature.

12. The light emitting apparatus of claim 1, wherein the optic device is further configured to pass radiation from the radiation source through the at least one transparent sidewall.

13. The light emitting apparatus of claim 1, wherein the first reflective surface is spaced away from the optic device.

14. A light emitting apparatus comprising:

an optic device having a top surface, a bottom surface, and at least one substantially transparent sidewall extending between the top surface and the bottom surface;

a radiation source for emitting short wavelength radiation, the radiation source disposed adjacent the bottom surface of the optic device;

a down conversion material, disposed on the top surface of the optic device and extending from the at least one transparent sidewall, receiving and down converting at least some of the short wavelength radiation emitted by the radiation source and back transferring a portion of the received and down converted radiation;

the optic device disposed between the down conversion material and the radiation source and configured to receive at least a portion of the radiation back-transferred from the down conversion material and to transfer at least some of the received portion of back-transferred radiation outside the optic device through the at least one substantially transparent sidewall;

a first reflective surface at least partially surrounding the optic device for reflecting at least some of the radiation back-transferred outside the optic device through the at least one substantially transparent sidewall; and

a second reflective surface at least partially surrounding the radiation source for reflecting at least some of the radiation emitted by the radiation source toward the down conversion material, an end of the second reflective surface extending from a bottom of the first reflective surface.

15. The light emitting apparatus of claim 14, wherein the first reflective surface is spaced away from the optic device.