Power light emitting diode and method with uniform current density operation

• US 10,553,754 B2
• Filed: 05/29/2018
• Issued: 02/04/2020
• Est. Priority Date: 09/18/2009
• Status: Active Grant

• Current Assignee: Korrus Incorporated (MKD Electric, Inc.)
• Original Assignee: Soraa, Inc.
• Inventors: Katona, Thomas M., Raring, James W., D'Evelyn, Mark P., Krames, Michael R., David, Aurelien J. F.
• Primary Examiner(s): Vu, Jimmy T
• Application Number:
  US15/991,951
• Publication Number:
  US 20190067517A1
• Time in Patent Office: 616 Days
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]

Abstract

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

Claims

1. An LED optical device comprising:

plurality of dies, each die of said plurality comprising a bulk GaN substrate and an active region over said substrate, said active region having an active region area,

said plurality of dies defining a cumulative active region area, said cumulative active region area being the total of said active region area for said each die for all of said plurality of dies;

a mixture comprising wavelength-converting material overlaying said plurality of dies to define a light-emitting outer surface, said light-emitting outer surface having a light-emitting outer surface area; and

wherein a ratio of said light-emitting outer surface area to said cumulative active region area is greater than 10.

2. The LED of claim 1, wherein said ratio is from 10:

1 to 100;

1.

3. The LED of claim 1, wherein said LED is configured to emit at least 300 lumens of white light from said light-emitting outer surface.

4. The LED of claim 1, wherein said LED is configured to operate at a power density great than 2 W/mm2 of active region.

5. The LED of claim 1, wherein said active region emits light having a wavelength of 405 nm to 430 nm, 385 nm to 415 nm, 385 nm to 480 nm, 390 nm to 430 nm, 390-415 nm, 415-440 nm, or 440-470 nm.

6. The LED of claim 1, wherein said plurality of dies is an array of dies.

7. The LED of claim 1, wherein a first portion of said plurality of dies s emits light having a wavelength of 405 nm to 430 and a second portion of said plurality of dies emits light having a wavelength of 440-470 nm.

8. The LED of claim 1, wherein a first portion of said plurality of dies emits violet light and a second portion of said plurality of dies emits blue light.

9. The LED of claim 1, said each die has an active region area of about 250 um×

250 um.

10. An LED optical device comprising:

plurality of dies, each die of said plurality comprising a bulk GaN substrate and an active region over said substrate, said active region having an active region area, said plurality of dies defining a cumulative active region area, said cumulative active region area being the total of said active region area for said each die for all of said plurality of dies;

a mixture comprising wavelength-converting material overlaying said plurality of dies die to define a light-emitting outer surface, said light-emitting outer surface having a light-emitting outer surface area;

wherein a first portion of said plurality of dies emits violet light and a second portion of said plurality of dies emits blue light; and

wherein a ratio of said light-emitting outer surface area to said cumulative active region area is greater than 5.

11. The LED of claim 10, wherein said ratio is from 10:

1 to 100;

1.

12. The LED of claim 10, wherein said LED is configured to emit at least 300 lumens of white light from said light-emitting outer surface.

13. The LED of claim 10, wherein said LED is configured to operate at a power density great than 2 W/mm2 of active region.

14. The LED of claim 10, wherein said plurality of dies is an array of dies.

15. The LED of claim 10, said each die has an active region area of about 250 um×

250 um.