Selective filtering of wavelength-converted semiconductor light emitting devices

• US 6,744,077 B2
• Filed: 09/27/2002
• Issued: 06/01/2004
• Est. Priority Date: 09/27/2002
• Status: Expired due to Term

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Inventors: Trottier, Troy A., Krames, Michael R., Mueller-Mach, Regina B., Mueller, Gerd O.
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): TRAN, MAI HUONG C
• Application Number:
  US10/260,090
• Publication Number:
  US 20040061124A1
• Time in Patent Office: 613 Days
• Field of Search: 257/98, 257/99, 257/100, 257/89
• US Class Current: 257/103
• CPC Class Codes: H01L 2224/14 of a plurality of bump connectors
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/50 Wavelength conversion elements

Abstract

A light emitting device includes a semiconductor light emitting device chip having a top surface and a side surface, a wavelength-converting material overlying at least a portion of the top surface and the side surface of the chip, and a filter material overlying the wavelength-converting material. The chip is capable of emitting light of a first wavelength, the wavelength-converting material is capable of absorbing light of the first wavelength and emitting light of a second wavelength, and the filter material is capable of absorbing light of the first wavelength. In other embodiments, a light emitting device includes a filter material capable of reflecting light of a first wavelength and transmitting light of a second wavelength.

Claims

1. A light emitting device comprising:

a semiconductor light emitting device chip capable of emitting first light having a first wavelength, the semiconductor light emitting device chip having a top surface and a side surface;

a wavelength-converting material capable of absorbing the first light and emitting second light having a second wavelength, the wavelength-converting material overlying at least a portion of the top surface and a portion the side surface; and

a filter material capable of absorbing the first light, the filter material overlying the wavelength-converting material.

2. The light emitting device of claim 1 wherein the filter material is dispersed in an encapsulant.

3. The light emitting device of claim 2 wherein the encapsulant comprises silicone.

4. The light emitting device of claim 1 further comprising a lens overlying the semiconductor light emitting device chip.

5. The light emitting device of claim 4 further comprising a plurality of leads electrically connected to the semiconductor light emitting device chip.

6. The light emitting device of claim 4 wherein the filter material is coated on a surface of the lens facing the semiconductor light emitting device chip.

7. The light emitting device of claim 4 wherein the filter material is coated on a surface of the lens facing away from the semiconductor light emitting device chip.

8. The light emitting device of claim 4 wherein the filter material is incorporated into the lens.

9. The light emitting device of claim 1 wherein the wavelength-converting material substantially conformally coats the semiconductor light emitting device chip.

10. The light emitting device of claim 1 wherein the wavelength-converting material is a phosphor.

11. The light emitting device of claim 10 wherein the phosphor is selected from the group consisting of YAG, YAG:

Ce+Pr, SrS;

Eu, and strontium thiogallate.

12. The light emitting device of claim 1 wherein the filter material comprises an organic dye.

13. The light emitting device of claim 1 wherein the filter material does not emit visible light.

14. A light emitting device comprising:

a semiconductor light emitting device chip capable of emitting first light having a first wavelength;

a wavelength-converting material capable of absorbing the first light and emitting second light having a second wavelength, the wavelength-converting material overlying at a top surface of the chip; and

a filter material capable of reflecting at least a portion of the first light and transmitting the second light, the filter material overlying the wavelength-converting material.

15. The light emitting device of claim 14 wherein the first light is UV light.

16. The light emitting device of claim 14 wherein the first light is blue light.

17. The light emitting device of claim 14 wherein the filter material comprises at least one dielectric layer.

18. The light emitting device of claim 17 further comprising a lens overlying the semiconductor light emitting device chip, wherein the at least one dielectric layer is formed on a surface of the lens.