Common optical element for an array of phosphor converted light emitting devices

• US 8,748,912 B2
• Filed: 11/03/2011
• Issued: 06/10/2014
• Est. Priority Date: 11/12/2004
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Philips Lumileds Lighting Company LLC (Apollo Global Management, Inc.)
• Inventors: Camras, Michael D., Imler, William R., Wall, Franklin J. Jr., Steranka, Frank M., Krames, Michael R., Ticha, Helena, Tichy, Ladislav, Alferink, Robertus G.
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US13/288,291
• Publication Number:
  US 20120043564A1
• Time in Patent Office: 950 Days
• Field of Search: 257/666, 257/88, 438/22, 438/27, 438/28, 438/30
• US Class Current: 257/88
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced.

Claims

1. An apparatus comprising:

a submount;

a plurality of light emitting device dice mounted to the submount; and

a single optical element attached to the plurality of light emitting device dice, wherein the single optical element is attached to the plurality of light emitting device dice by bonding the single optical element to a surface of each of the plurality of light emitting device dice.

2. The apparatus of claim 1, further comprising contact elements that are on at least one of the top surface of the submount and the bottom surfaces of the light emitting device dice, the light emitting device dice being electrically coupled to the submount through the contact elements.

3. The apparatus of claim 2, wherein the contact elements are formed from a material that includes at least one of Au and AuSn.

4. The apparatus of claim 1, further comprising a coating of wavelength converting material over the single optical element.

5. The apparatus of claim 1, further comprising a layer of wavelength converting material between the single optical element and at least a plurality of the light emitting device dice.

6. The apparatus of claim 1, wherein the submount and the single optical element are formed from materials with approximately the same coefficient of thermal expansion.

7. The apparatus of claim 6, wherein the light emitting device dice have coefficients of thermal expansion that are approximately the same as the coefficient of thermal expansion of the submount.

8. The apparatus of claim 1, further comprising a layer of a bonding material between the single optical element and each of the light emitting device dice, the bonding layer comprising an inorganic material.

9. The apparatus of claim 1, wherein each of the light emitting device dice comprise a stack of semiconductor layers, at least one of which is an active region that emits lights, and a first contact and a second contact electrically coupled to apply a voltage across the active region;

the first contact and the second contact disposed on a same side of the stack.

10. A device comprising:

a semiconductor light emitting device comprising a stack of semiconductor layers including an active region;

an optical element bonded to the semiconductor light emitting device, wherein the optical element comprises a material selected from the group of aluminum oxynitride, spinel, and transparent alumina;

a bonding layer disposed between the optical element and the semiconductor light emitting device, wherein the bonding layer comprises an oxide of tellurium; and

a submount electrically connected to the light emitting device.

11. The device of claim 10, wherein the submount comprises a ceramic.

12. The device of claim 10, wherein the submount comprises a material selected from the group of AIN, alumina, and Si.

13. The device of claim 10, further comprising contact elements that electrically connect the submount to the light emitting device, wherein the contact elements are formed from a material that includes at least one of Au and AuSn.

14. A device comprising:

-4- Ser. No. 13/288,291 a semiconductor light emitting device comprising a stack of semiconductor layers including an active region;

an optical element bonded to the semiconductor light emitting device, wherein the optical element comprises a material selected from the group of aluminum oxynitride, spinel, and transparent alumina; and

a bonding layer disposed between the optical element and the semiconductor light emitting device, wherein the bonding layer comprises a material selected from the group of an oxide of lead, an oxide of tungsten, and an oxide of zinc.

15. The device of claim 14, further comprising a submount electrically connected to the light emitting device.

16. The device of claim 15, wherein the submount comprises a ceramic.

17. The device of claim 15, wherein the submount comprises a material selected from the group of AIN, alumina, and Si.

18. The device of claim 15, further comprising contact elements that electrically connect the submount to the light emitting device, wherein the contact elements are formed from a material that includes at least one of Au and AuSn.