Side emitting LED device and method of fabrication

• US 20060091418A1
• Filed: 11/04/2004
• Published: 05/04/2006
• Est. Priority Date: 11/04/2004
• Status: Abandoned Application

• Current Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Chew, Tong Fatt
• Application Number:
  US10/981,042
• Publication Number:
  US 20060091418A1
• Time in Patent Office: Days
• US Class Current: 257/100
• CPC Class Codes: H01L 33/54 having a particular shape

Abstract

In one embodiment, a light emitting diode (LED) device comprises an LED die for generating output light and an encapsulant sealing the LED die, the encapsulant comprising a conical structure extending away from the LED die and positioned above the LED die, wherein a profile of the conical structure causes a cone of light centered around an axis of symmetry of the LED die to experience total internal reflection.

Claims

1. A light emitting diode (LED) device, comprising:

an LED die for generating output light; and

an encapsulant sealing said LED die, said encapsulant comprising a conical structure extending away from said LED die and positioned above said LED die, wherein a profile of said conical structure causes a cone of light centered around an axis of symmetry of said LED die to experience total internal reflection.

2. The LED device of claim 1 wherein said encapsulant causes said LED device to operate as a side emission device.

3. The LED device of claim 1 wherein said conical structure is disposed within a depression of said encapsulant.

4. The LED device of claim 3 wherein light incident on said depression is refracted away from said axis of symmetry.

5. The LED device of claim 1 wherein said encapsulant comprises multiple layers including a mold cup layer.

6. The LED device of claim 1 wherein said mold cup layer comprises said conical structure.

7. A method of fabricating a light emitting diode (LED) device, comprising:

providing a mold defining an encapsulant profile;

dispensing liquid encapsulant material into said mold;

providing an LED die; and

curing said liquid encapsulant to encapsulate said LED die, wherein said cured encapsulant possesses a conical structure above and extending away from said LED die, wherein a profile of said conical structure causes a cone of light centered around an axis of symmetry of said LED die to experience total internal reflection.

8. The method of claim 7 wherein said dispensing is performed according to injection molding.

9. The method of claim 7 wherein said dispensing is performed according to transfer molding.

10. The method of claim 7 further comprising:

removing said mold after performing said curing.

11. The method of claim 7 wherein said mold is integrated with said cured encapsulant upon completion of said LED device.

12. The method of claim 7 wherein said conical structure is disposed within a depression of said cured encapsulant.

13. The method of claim 12 wherein light incident upon said depression is refracted away from said axis of symmetry.

14. A liquid crystal display (LCD), comprising:

a liquid crystal panel;

a backlighting module for illuminating said liquid crystal panel that comprises a plurality of light emitting diode (LED) devices, wherein each LED device comprises an encapsulant sealing an LED die, said encapsulant comprising a conical structure extending away from said LED die and positioned above said LED die, wherein a profile of said conical structure causes a cone of light centered around an axis of symmetry of said LED die to experience total internal reflection.

15. The LCD of claim 14 wherein said encapsulant causes said LED device to operate as a side emission device.

16. The LCD of claim 14 wherein said conical structure is disposed within a depression of said encapsulant.

17. The LCD of claim 16 wherein light incident on said depression is refracted away from said axis of symmetry.

18. The LCD of claim 14 wherein said encapsulant comprises multiple layers including a mold cup layer.

19. The LCD of claim 14 wherein said mold cup layer comprises said conical structure.

20. The LCD of claim 14 wherein said liquid crystal panel comprises a diffusing layer.