High efficiency light emitting diode package suitable for wafer level packaging

• US 9,318,671 B2
• Filed: 04/18/2014
• Issued: 04/19/2016
• Est. Priority Date: 04/18/2014
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Toshiba Corporation
• Inventors: Liu, Kai, Lin, Chao-Kun
• Primary Examiner(s): Stultz, Jessica
• Assistant Examiner(s): Vu, Vu A
• Application Number:
  US14/256,715
• Publication Number:
  US 20150303359A1
• Time in Patent Office: 732 Days
• Field of Search: 257/98
• US Class Current: 1/1
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An LED package and method for LED packaging is disclosed. In one embodiment, an LED package includes a carrier substrate having a predefined surface area, an LED device bonded to the carrier substrate, the LED device having a footprint area of at least fifty percent of the predefined surface area of the carrier substrate, and an encapsulant lens having a top surface inclined inwardly at an angle in the range of about 10° to about 140°. In one embodiment, the top surface of the encapsulant lens layer has a concave cone shape. In one embodiment, a wafer level packaging process includes forming an encapsulant lens layer portion having a top surface inclined inwardly at an angle in the range of about 10° to about 140° on each of a plurality of LED devices bonded to a carrier substrate wafer.

Claims

1. A light emitting diode (LED) package comprising:

a carrier substrate having a predefined surface area;

an LED device bonded to the carrier substrate, the LED device having a top surface, a footprint area of at least fifty percent of the predefined surface area of the carrier substrate, and a sidewall having a set back distance from a sidewall of the carrier substrate, wherein the set back distance is between one quarter of one percent and fifteen percent of a width of the carrier substrate; and

an encapsulant lens formed over the LED device, the encapsulant lens having a top surface inclined inwardly toward the top surface of the LED device and having a thickness at an interior portion of at least ten percent of a thickness at a peripheral portion relative to the top surface of the LED device.

2. The LED package of claim 1, wherein the top surface of the encapsulant lens is inclined inwardly at an angle in the range of about 10°

to about 140°

.

3. The LED package of claim 2, wherein the angle is in the range of about 10°

to about 90°

.

4. The LED package of claim 2, wherein the top surface of the encapsulant lens has a concave shape.

5. The LED package of claim 4, wherein the concave shape is a cone.

6. The LED package of claim 2, wherein the top surface of the encapsulant lens has a plurality of concave shapes.

7. The LED package of claim 6, wherein each of the plurality of concave shapes is a cone.

8. The LED package of claim 1, further comprising a phosphor-containing layer disposed on a top surface of the LED device.

9. The LED package of claim 1, wherein the LED device has a footprint area of about ninety-five percent of the predefined surface area of the carrier substrate.

10. The LED package of claim 1, wherein the encapsulant lens has a footprint area substantially the same as the predefined surface area of the carrier substrate.

11. The LED package of claim 1, wherein the set back distance is in the range of ten μ

m and fifty μ

m.

12. A light emitting diode (LED) package comprising:

a carrier substrate having a predefined surface area;

an LED device bonded to the carrier substrate, the LED device having a footprint area of at least fifty percent of the predefined surface area of the carrier substrate, and a side wall having a set back distance from a side wall of the carrier substrate, wherein the set back distance is between one quarter of one percent and fifteen percent of a width of the carrier substrate; and

an encapsulant lens formed over the LED device, the encapsulant lens having a top surface shaped in such a way that the LED package is capable of emitting at least 81 percent of light emitted by the LED device.

13. The LED package of claim 12, wherein the top surface of the encapsulant lens is shaped in such a way that the LED package is capable of emitting at least about 83 percent of light emitted by the LED device.

14. The LED package of claim 12, wherein the encapsulant lens has a top surface inclined inwardly at an angle in the range of about 10°

to about 140°

.

15. The LED package of claim 14, wherein the angle is in the range of about 10°

to about 90°

.

16. The LED package of claim 12, wherein the top surface of the encapsulant lens has a concave shape.

17. The LED package of claim 16, wherein the concave shape is a cone.

18. The LED package of claim 12, wherein the top surface of the encapsulant lens has a plurality of concave shapes.

19. The LED package of claim 18, wherein each of the plurality of concave shapes is a cone.

20. The LED package of claim 12, further comprising a phosphor-containing layer disposed on a top surface of the LED device.

21. The LED package of claim 12, wherein the LED device has a footprint area of about ninety-five percent of the predefined surface area of the carrier substrate.

22. The LED package of claim 12, wherein the encapsulant lens has a footprint area substantially the same as the predefined surface area of the carrier substrate.

23. The LED package of claim 12, wherein the set back distance is in the range of ten μ

m and fifty μ

m.

24. A method for packaging a light emitting diode (LED) device, comprising:

forming an encapsulant lens layer on a carrier substrate wafer having a plurality of LED devices disposed thereon, the encapsulant lens layer including a plurality of portions, each portion disposed over one of the plurality of LED devices and each portion of the encapsulant lens layer having a top surface inclined inwardly toward the top surface of the LED device and having a thickness at an interior portion of at least ten percent of a thickness at a peripheral portion relative to the top surface of the LED device; and

dicing the carrier substrate wafer into a plurality of LED packages such that each LED package includes an LED device with a footprint area of at least fifty percent of a surface area of a carrier substrate, and a side wall having a set back distance from a side wall of the carrier substrate, the set back distance being between one quarter of one percent and fifteen percent of a width of the carrier substrate.

25. The method of claim 24, wherein forming an encapsulant lens layer includes compression molding a transparent silicone material.

26. The method of claim 24, wherein forming an encapsulant lens layer includes injection molding a transparent silicone material.

27. The method of claim 24, wherein forming an encapusulant lens layer includes each portion of the encapsulant lens layer having a top surface inclined inwardly at an angle in the range of about 10°

to about 140°

.

28. The method of claim 24, wherein forming an encapsulant lens layer includes each portion of the encapsulant lens layer having a top surface inclined inwardly at an angle in the range of about 10°

to about 90°

.

29. The method of claim 24, further comprising dicing the carrier substrate wafer into a plurality of LED packages such that each LED package includes an LED device with a footprint area that is about ninety-five percent of the surface area of a carrier substrate.

30. The method of claim 24, further comprising:

bonding a carrier substrate wafer to a device wafer, the device wafer comprising a plurality of LED devices built on a growth substrate; and

removing the growth substrate from the plurality of LED devices to produce the carrier substrate wafer having the plurality of LED devices disposed thereon.

31. The method of claim 24, the encapsulant lens having a footprint area substantially the same as the predefined surface area of the carrier substrate.

32. The method of claim 24, wherein the set back distance is in the range of ten μ

m and fifty μ

m.