High-power white LEDs

• US 10,305,001 B2
• Filed: 07/07/2015
• Issued: 05/28/2019
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Narendran, Nadarajah, Gu, Yimin
• Primary Examiner(s): Petkovsek, Daniel
• Application Number:
  US14/793,083
• Publication Number:
  US 20150325754A1
• Time in Patent Office: 1,421 Days
• 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 includes a first radiation source without a dome, a substantially transparent and light transmissive optic device, a lens, a down conversion material, and a heat sink. The optic device is devoid of scattering particles and phosphor, and includes a planar top surface distal the first radiation source, a bottom surface proximal the first radiation sources, and a transparent sidewall extending between the top surface and the bottom surface. The down conversion material includes a flat layer including phosphor that is disposed on the planar top surface of the optic device between the lens and the radiation source. The heat sink, upon which the radiation source is mounted, has a recess formed therein in which an air space is defined between a boundary of the recess and the optic device.

Claims

1. A light emitting apparatus comprising:

a first radiation source without a dome;

an optic device comprising a top surface distal the first radiation source, a bottom surface proximal the first radiation source, and a transparent sidewall connecting the top surface and the bottom surface and through which light radiation from the first radiation source is configured to escape from the transparent sidewall;

a base on which the first radiation source disposed;

a lens disposed on the optic device, and separated from the transparent sidewall of the optic device by an air space which is enclosed by the optic device, the lens, and the base; and

a down conversion material disposed between the lens and the radiation source;

wherein the light emitting apparatus has a maximum height of 2 mm-10 mm in a direction perpendicular to the top surface of the optic device.

2. The light emitting apparatus of claim 1, further comprising a second radiation source,

wherein the first radiation source and the second radiation source are arranged in the optic device.

3. The light emitting apparatus of claim 2, wherein the down conversion material is arranged to continuously cover the first radiation source and the second radiation source.

4. The light emitting apparatus of claim 1, further comprising a sealant between the optic device and the first radiation source.

5. The light emitting apparatus of claim 4, wherein the sealant has a refractive index of 1.5-2.3.

6. The light emitting apparatus of claim 1, wherein the optic device has a refractive index of 1.4-1.7.

7. The light emitting apparatus of claim 1, wherein the bottom surface of the optic device has a widest width smaller than that of the top surface.

8. The light emitting apparatus of claim 1, wherein the transparent sidewall of the optic device comprises a straight portion, a curved portion, or both thereof.

9. The light emitting apparatus of claim 1, wherein the light emitting apparatus is devoid of a bonding wire.

10. The light emitting apparatus of claim 1, wherein the lens has a greatest width greater than that of the first radiation source in a width direction substantially parallel to the bottom surface of the optic device.

11. The light emitting apparatus of claim 1, wherein the lens has a greatest width greater than that of the down conversion material in a width direction substantially parallel to the bottom surface of the optic device.

12. The light emitting apparatus of claim 1, wherein the optic device has a planar top surface.

13. The light emitting apparatus of claim 1, further comprising a reflective surface surrounding the optic device, the phosphor material, and the first radiation source.

14. The light emitting apparatus of claim 1, further comprising a reflective surface under the first radiation source and directing the light extracted from the first radiation source toward the down conversion material.

15. The light emitting apparatus of claim 1, further comprising a reflector surrounding the optic device, the phosphor material, and the first radiation source and having an elevation is not higher than the down conversion material.