Light-emitting diode package and method of manufacturing the same

• US 10,644,205 B2
• Filed: 09/12/2018
• Issued: 05/05/2020
• Est. Priority Date: 03/09/2018
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Dong-kuk, Kim, Moon-sub, Ahn, Sung-jin, Yoon, Suk-ho, Lee, Seung-hwan
• Primary Examiner(s): Huynh, Andy
• Application Number:
  US16/129,021
• Publication Number:
  US 20190280162A1
• Time in Patent Office: 601 Days
• Field of Search: 257 99
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/26 Materials of the light emitting region
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/50 Wavelength conversion 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

Abstract

A light-emitting diode (LED) package includes: an LED having a polygonal shape in a plan view; a light-transmissive layer directing light from the LED in an upward direction; a wavelength conversion layer changing a wavelength of the light emitted through the light-transmissive layer; and a coating layer covering the light-transmissive layer and reflecting the light emitted through the light-transmissive layer in the upward direction. In a plan view of the light-transmissive layer, a length from a first point corresponding to a vertex of the LED to a second point corresponding to an end of an extension of a diagonal of the LED is greater than or equal to a length from the first point to a third point corresponding to an end of an extension of a side of the LED.

Claims

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

an LED having an upper surface, a lower surface, and side surfaces connecting the upper surface and the lower surface, and configured to generate and emit light, the LED having a polygonal shape in a plan view of the LED package;

a light-transmissive layer covering the upper surface and at least some portions of the side surfaces of the LED, and configured to direct the light emitted from the LED in an upward direction;

a wavelength conversion layer disposed on the light-transmissive layer, and configured to change a wavelength of the light emitted through the light-transmissive layer; and

a coating layer covering side surfaces of the light-transmissive layer, and configured to reflect the light emitted through the light-transmissive layer in the upward direction at an interface with the light-transmissive layer,

wherein, in a sectional view of the LED package, the side surfaces of the light-transmissive layer are inclined with respect to the side surfaces of the LED, and

wherein, on a top surface of the light-transmissive layer, a length from a first point to a second point is greater than or equal to a length from the first point to a third point,

wherein the first point is positioned vertically above a vertex of the LED in the plan view,

wherein the second point is positioned at an end of a first virtual line on the top surface of the light-transmissive layer which overlaps a diagonal of a top surface of the LED and passes through the first point, the end of the first virtual line being the closest to the first point among both ends of the first virtual line, and

wherein the third point is positioned at an end of a second virtual line on the top surface of the light-transmissive layer which overlaps a side of the top surface of the LED and passes through the first point, the end of the second virtual line being the closest to the first point among both ends of the second virtual line.

2. The LED package of claim 1, wherein, in the plan view of the LED package, the light-transmissive layer has a polygonal shape corresponding to the polygonal shape of the LED and having a greater size than the LED.

3. The LED package of claim 1, wherein the LED comprises a light emitting structure and a light-transmissive substrate having an interface fainted with the light-transmissive layer, and

wherein, the light-transmissive substrate comprises at least one of sapphire (Al₂O₃), gallium nitride (GaN), germanium (Ge), gallium arsenide (GaAs), zinc oxide (ZnO), silicon germanium (SiGe), silicon carbide (SiC), gallium oxide (Ga₂O₃), lithium gallium oxide (LiGaO₂), lithium aluminum oxide (LiAlO₂), and magnesium aluminum oxide (MgAl₂O₄), and

wherein the light-transmissive layer comprises a silicon resin.

4. The LED package of claim 1, wherein the LED comprises a light emitting structure and a light-transmissive substrate having an interface fainted with the light-transmissive layer, and

wherein a refractive index of the light-transmissive substrate is greater than the light-transmissive layer.

5. The LED package of claim 1, wherein, in the plan view, a size of the light-transmissive layer is greater than a size of the LED, and

wherein a size of the wavelength conversion layer is greater than the size of the light-transmissive layer.

6. The LED package of claim 1, further comprising an interlayer as a buffer layer between the light-transmissive layer and the wavelength conversion layer,

wherein the interlayer has a refractive index greater than the wavelength conversion layer and lower than the light-transmissive layer.

7. The LED package of claim 1, wherein a thickness of the coating layer is greater than the light-transmissive layer.

8. The LED package of claim 7, wherein the thickness of the light-transmissive layer ranges 100 μ

m to 350 μ

m, and the thickness of the coating layer ranges 150 μ

m to 500 μ

m.

9. The LED package of claim 1, wherein the coating layer comprises at least one selected from the group consisting of SiO₂, MgF₂, SiN, TiO₂, and Nb₂O₅.

10. The LED package of claim 1, wherein side surfaces of the wavelength conversion layer and side surfaces of the coating layer are coplanar.

11. The LED package of claim 1, wherein the LED comprises a light emitting structure, a light-transmissive substrate disposed thereon, and an electrode pad,

wherein the light emitting structure comprises a first-conductive-type semiconductor layer, a second-conductive-type semiconductor layer, and an active layer interposed therebetween, and

wherein the light-transmissive layer covers entirety of the side surfaces of the light emitting structure and the light-transmissive substrate.

12. The LED package of claim 11, wherein the coating layer covers entirety of side surfaces of the light-transmissive layer forming the interface between the light-transmissive layer and the coating layer and at least some portions of side surfaces of the electrode pad.

13. The LED package of claim 12, further comprising an electrode coating layer covering at least some portions of side surfaces of the electrode pad,

wherein the light-transmissive layer covers at least some portions of side surfaces of the electrode coating layer.

14. A light-emitting diode (LED) package comprising:

an LED having an upper surface, a lower surface, and side surfaces connecting the upper surface and the lower surface, and configured to generate and emit light;

a light-transmissive layer covering the upper surface and the side surfaces of the LED, and configured to direct the light emitted from the LED in an upward direction;

a wavelength conversion layer disposed on the light-transmissive layer, and configured to change a wavelength of the light emitted through the light-transmissive layer; and

a coating layer covering the side surfaces of the light-transmissive layer, and configured to reflect the light emitted through the light-transmissive layer in the upward direction at an interface with the light-transmissive layer,

wherein, in a plan view of the LED package, the LED has a polygonal shape and the light-transmissive layer has a corresponding polygonal shape in the plan view, and

wherein, in a sectional view of the LED package, the side surfaces of the light-transmissive layer are inclined with respect to the side surfaces of the LED, and an angle formed by an edge connecting two adjacent side surfaces of the light-transmissive layer and a corresponding edge of the LED is greater than or equal to an angle formed by a side surface of the light-transmissive layer and a corresponding side surface of the LED.

15. The LED package of claim 14, wherein the LED comprises a light emitting structure and a light-transmissive substrate having an interface formed with the light-transmissive layer,

wherein the light-transmissive substrate comprises at least one of sapphire (Al₂O₃), gallium nitride (GaN), germanium (Ge), gallium arsenide (GaAs), zinc oxide (ZnO), silicon germanium (SiGe), silicon carbide (SiC), gallium oxide (Ga₂O₃), lithium gallium oxide (LiGaO₂), lithium aluminum oxide (LiAlO₂), and magnesium aluminum oxide (MgAl₂O₄), and

wherein the light-transmissive layer comprises a silicon resin.

16. The LED package of claim 15, wherein the coating layer comprises at least one selected from the group consisting of SiO₂, MgF₂., SiN, TiO₂, and Nb₂O₅.

17. The LED package of claim 14, wherein the LED comprises a light emitting structure and a light-transmissive substrate having an interface formed with the light-transmissive layer, and

wherein a refractive index of the light-transmissive substrate is greater than the light-transmissive layer.

18. A light-emitting diode (LED) package comprising:

an LED having an upper surface, a lower surface, and side surfaces connecting the upper surface and the lower surface, and configured to generate and emit light;

a light-transmissive layer covering the upper surface and the side surfaces of the LED;

a wavelength conversion layer disposed on the light-transmissive layer, and configured to change a wavelength of the light emitted through the light-transmissive layer; and

a coating layer covering the side surfaces of the light-transmissive layer, and configured to reflect the light emitted through the light-transmissive layer in an upward direction,

wherein, in a plan view of the LED package, the LED has a polygonal shape and the light-transmissive layer has a corresponding polygonal shape,

wherein, on a top surface of the light-transmissive layer, a length from a first point to a second point is greater than or equal to a length from the first point to a third point,

wherein the first point is positioned vertically above a vertex of the LED in the plan view,

wherein the second point is positioned at an end of a first virtual line on the top surface of the light-transmissive layer which overlaps a diagonal of a top surface of the LED and passes through the first point, the end of the first virtual line being the closest to the first point among both ends of the first virtual line,

wherein the third point is positioned at an end of a second virtual line on the top surface of the light-transmissive layer which overlaps a side of the top surface of the LED and passes through the first point, the end of the second virtual line being the closest to the first point among both ends of the second virtual line, and

wherein, in a sectional view of the LED package, the side surfaces of the light-transmissive layer are inclined with respect to the side surfaces of the LED, and an angle formed by an edge connecting two adjacent side surfaces of the light-transmissive layer and a corresponding edge of the LED is greater than or equal to an angle formed by a side surface of the light-transmissive layer and a corresponding side surface of the LED.

19. The LED package of claim 18, wherein the LED comprises a light emitting structure, a light-transmissive substrate disposed thereon, and an electrode pad,

wherein the light emitting structure comprises a first-conductive-type semiconductor layer, a second-conductive-type semiconductor layer, and an active layer interposed therebetween, and

wherein the light-transmissive layer covers entirety of the side surfaces of the light emitting structure and the light-transmissive substrate.

20. The LED package of claim 18, wherein the coating layer covers entirety of side surfaces of the light-transmissive layer forming an interface between the light-transmissive layer and, the coating layer and at least some portions of side surfaces of the electrode pad.