Light emitting die (LED) packages and related methods

Patent metadata

Field	Value
Publication number	US-10256385-B2
Application number	US-201113187232-A
Country	US
Kind code	B2
Filing date	Jul 20, 2011
Priority date	Oct 31, 2007
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

LED packages and related methods are provided. The LED packages can include a submount having a top and bottom surface and a plurality of top electrically conductive elements on the top surface of the submount. An LED can be disposed on one of the top electrically conductive elements. The LED can emit a dominant wavelength generally between approximately 600 nm and approximately 650 nm, and more particularly between approximately 610 nm and approximately 630 nm when an electrical signal is applied to the top electrically conductive elements. A bottom thermally conductive element can be provided on the bottom surface and is not in electrical contact with the top electrically conductive elements. A lens can be disposed over the LED. The LED packages can have improved lumen performances, lower thermal resistances, improved efficiencies, and longer operational lifetimes.

First claim

What is claimed is:

1. A light-emitting die (LED) package comprising:
a ceramic submount comprising a top surface, a bottom surface, and a plurality of side edges;
a bottom thermally conductive element disposed on the bottom surface of the submount for conducting heat from the submount;
an LED having a multi-quantum well and disposed on the submount, the LED operable for emitting a dominant wavelength between approximately 610 nm and approximately 630 nm, the LED having a luminous flux that is approximately 100 lm or greater, such that a minimum luminous flux to footprint ratio for the LED package is greater than approximately 5.8 lm/mm 2 of a footprint of the LED package when an electrical signal comprises a current of approximately 350 mA;
a flux eutectic LED die attachment attaching the LED to the submount;
a lens molded over the LED and the submount; and
a protective layer substantially disposed over the top surface of the ceramic submount between the ceramic submount and the lens;
wherein a polarity of the LED is such that an N-cladding of the LED is below the multi-quantum well and a P-cladding of the LED is above the multi-quantum well; and

wherein each of the plurality of side edges of the ceramic submount is substantially flush with a corresponding side edge of the protective layer,
wherein the LED package generates a light output of approximately 120 lumens/watt or greater.

2. The LED package of claim 1 , wherein the submount comprises aluminum nitride.

3. The LED package of claim 1 , wherein the LED package is configured to generate a light output of approximately 130 lumens/watt or greater.

4. The LED package of claim 1 , wherein the LED package is configured to have a predicted L70 lifetime of at least 50,000 hours or greater at 350 milliamps and 85° C.

5. The LED package of claim 1 , wherein the lens is of a radius size of approximately 1.275 mm or greater.

6. The LED package of claim 1 wherein the LED package comprises:
a plurality of top electrically conductive elements on the top surface of the submount; and
the LED disposed on at least one of the top electrically conductive elements.

7. The LED package of claim 6 , wherein the submount comprises aluminum nitride.

8. The LED package of claim 1 , wherein the protective layer is substantially disposed over an entirety of the top surface of the ceramic submount between the ceramic submount and the lens.

9. A light-emitting die (LED) package comprising:
a ceramic submount comprising a top surface, a bottom surface, and a plurality of side edges;
a bottom thermally conductive element disposed on the bottom surface of the submount for conducting heat from the submount;
an LED having a multi-quantum well and disposed on the submount, the LED operable for emitting a dominant wavelength between approximately 610 nm and approximately 630 nm, the LED having a luminous flux that is approximately 100 lm or greater, such that a minimum luminous flux to footprint ratio for the LED package is greater than approximately 5.8 lm/mm 2 of a footprint of the LED package when an electrical signal comprises a current of approximately 350 mA;
a flux eutectic LED die attachment attaching the LED to the submount;
a lens molded over the LED and the submount; and
a protective layer substantially disposed over the top surface of the ceramic submount between the ceramic submount and the lens;
wherein a polarity of the LED is such that an N-cladding of the LED is below the multi-quantum well and a P-cladding of the LED is above the multi-quantum well; and
wherein each of the plurality of side edges of the ceramic submount is substantially flush with a corresponding side edge of the protective layer,
wherein the LED package generates a light output of approximately 120 lumens/watt or greater.

10. The LED package of claim 9 , wherein the submount comprises aluminum nitride.

11. The LED package of claim 9 , wherein the LED package is configured to generate a light output of approximately 130 lumens per watt or greater.

12. The LED package of claim 9 , wherein the LED package is configured to have a predicted L70 lifetime of at least 50,000 hours or greater at 350 milliamps and 85° C.

13. The LED package of claim 9 , wherein the lens is of a radius size of approximately 1.275 mm or greater.

14. The LED package of claim 9 wherein the LED package comprises:
a plurality of top electrically conductive elements on the top surface of the submount; and
the LED disposed on one of the top electrically conductive elements.

15. The LED package of claim 14 , wherein the submount comprises aluminum nitride.

16. A light-emitting die (LED) package comprising:
a submount comprising aluminum nitride comprising a top surface, a bottom surface, and a plurality of side edges;
a bottom thermally conductive element disposed on the bottom surface of the submount for conducting heat from the submount;
an LED having a multi-quantum well and disposed on the submount, the LED operable for emitting a dominant wavelength between approximately 610 nm and approximately 630 nm, the LED having a luminous flux that is approximately 100 lm or greater, such that a minimum luminous flux to footprint ratio for the LED package is greater than approximately 5.8 lm/mm 2 of a footprint of the LED package when an electrical signal comprises a current of approximately 350 mA;
a flux eutectic LED die attachment attaching the LED to the submount;
a lens molded over the LED and the submount; and
a protective layer substantially disposed over the top surface of the submount between the submount and the lens;
wherein a polarity of the LED is such that an N-cladding of the LED is below the multi-quantum well and a P-cladding of the LED is above the multi-quantum well; and
wherein each of the plurality of side edges of the ceramic submount is substantially flush with a corresponding side edge of the protective layer,
wherein the LED package generates a light output of approximately 120 lumens/watt or greater.

17. A method of operating a light-emitting die (LED) package comprising:
providing an LED package comprising:
a ceramic submount comprising a top surface, a bottom surface, and a plurality of side edges;
a bottom thermally conductive element disposed on the bottom surface of the submount for conducting heat from the submount;
an LED disposed on the submount, the LED having a multi-quantum well with a polarity such that an N-cladding of the LED is below the multi-quantum well and a P-cladding of the LED is above the multi-quantum well, the LED operable for emitting a dominant wavelength between approximately 610 nm and approximately 630 nm, the LED having a luminous flux that is approximately 100 lm or greater, such that a minimum luminous flux to footprint ratio for the LED package is greater than approximately 5.8 lm/mm 2 of a footprint of the LED package when an electrical signal comprises a current of approximately 350 mA;
a flux eutectic LED die attachment attaching the LED to the submount;
a lens molded over the LED and the submount;
wherein each of the plurality of side edges of the ceramic submount is substantially flush with a corresponding side edge of the protective layer;

applying an electrical signal to the LED package; and
generating a light output from the LED in the LED package that is approximately 120 lumens per watts or greater.

18. The method of claim 17 , wherein the LED package is configured to have a predicted L70 lifetime of at least 50,000 hours or greater at 350 milliamps and 85

Assignees

• Britt Jeffrey Carl
• Fu Yankun
• Cree Inc

Inventors

• Britt Jeffrey Carl
• Stanton Brandon
• Fu Yankun

Classifications

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W90/754

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/59

  Bond pads specially adapted therefor · CPC title

• H10W72/075

  of bond wires · CPC title