LED packages with mushroom shaped lenses and methods of manufacturing LED light-emitting devices

• US 20070241357A1
• Filed: 04/27/2007
• Published: 10/18/2007
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: LED Engin, Inc. (Ams-Osram AG)
• Original Assignee: Ledengin, Inc. (Ams-Osram AG)
• Inventors: Yan, Xiantao
• Granted Patent: US 8,816,369 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/48 characterised by the semiconductor body packages
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements

Abstract

Methods of fabricating a light-emitting device are provided. A light-emitting device can be formed from bonding a lens including a plug and a cap to an LED package including a socket configured to receive the plug. The lens can be fabricated using an injection mold formed from a well secured to the LED package and injecting a material into the injection mold to cure into a shape of the lens. The lens can also be fabricated using a blank about the shape of the lens and machining the blank to produce the plug and the cap of the lens. The lens can be bonded to the LED package using a convex bead of adhesive deposited on the surface of the LED package and spreading the adhesive between the lens and the LED package.

Claims

1. A light-emitting device comprising:

a package including

a light-emitting side,

an encapsulated LED configured to emit light toward the light-emitting side of the package, and

a socket including a sidewall and a bottom surface, the socket disposed on the light-emitting side of the package; and

a lens including a cap and a plug, the plug disposed within the socket.

2. The light-emitting device of claim 1, wherein an angle defined between the sidewall and the bottom surface is between about 45 degrees to about 140 degrees.

3. The light-emitting device of claim 1, wherein an angle defined between a sidewall of the plug and a lower surface of the lens is between about 45 degrees to about 140 degrees.

4. The light-emitting device of claim 1, wherein the shape of the lens comprises a mushroom shape.

5. The light-emitting device of claim 1, wherein the package further includes a plurality of layers.

6. The light-emitting device of claim 5, wherein a layer of the plurality of layers includes aluminum nitride.

7. The light-emitting device of claim 5, wherein the plurality of layers includes a thermal insulation layer.

8. The light-emitting device of claim 5, wherein the plurality of layers includes an alignment layer.

9. The light-emitting device of claim 1, further including an adhesive layer disposed between the lens and the package.

10. The light-emitting device of claim 9, wherein the adhesive layer includes silicone.

11. The light-emitting device of claim 1, wherein the lens in plan view describes a figure including a first diameter in a first axis and a second diameter in a second axis, the second diameter greater than the first diameter.

12. The light-emitting device of claim 11, wherein a ratio of the first diameter to the second diameter is about 9 to 16.

13. The light-emitting device of claim 1, wherein the lens in plan view describes a generally rectangular figure.

14. The light-emitting device of claim 1, wherein a material of the lens comprises a plastic.

15. The light-emitting device of claim 1, wherein a shape of the cap includes a hemisphere.

16. The light-emitting device of claim 1, wherein a shape of the cap includes a convex spherical section having a radius greater than a radius of the plug.

17. A method of fabricating a light-emitting device, the method comprising:

providing a package including an encapsulated LED configured to emit light toward a light-emitting side of the package, and a socket disposed on the light-emitting side of the package;

providing a lens including a plug and a cap;

depositing an adhesive within the socket; and

attaching the lens to the light-emitting side of the package, such that the plug is disposed within the socket.

18. The method of claim 17, wherein providing the lens comprises machining a lens blank to form the plug of the lens.

19. The method of claim 18, wherein machining the lens blank comprises turning the lens blank.

20. The method of claim 19, wherein the lens blank comprises glass.

21. A method of fabricating a light-emitting device, the method comprising:

providing a package including an encapsulated LED configured to emit light toward a light-emitting side of the package, and a socket disposed on the light-emitting side of the package;

placing a mold over the socket, the mold defining a shape of a cap;

flowing a material into a space formed by the mold and the socket; and

curing the material.

22. The method of claim 21, wherein the material comprises plastic.

23. The method of claim 21, wherein the material comprises silicone.

24. A method of attaching an LED lens to an LED package to form a light-emitting device, the method comprising:

introducing a bead of adhesive having a convex surface and a viscosity of about 2000 to 4000 centipoise onto a surface of the LED package;

contacting a point on the convex surface of the bead of adhesive with a surface of the LED lens; and

spreading the adhesive between the surface of the LED package and the surface of the LED lens.

25. The method of claim 24, wherein the contacted point on the convex surface of the bead of adhesive is at about an apex of the convex surface of the bead of adhesive.

26. The method of claim 24, wherein a width of the bead of adhesive is between about 30 percent to about 55 percent of a length of the surface of the LED package.

27. The method of claim 24, wherein a height of the bead of adhesive is between about 20 percent to about 35 percent of a width of the bead of adhesive.

28. The method of claim 24, wherein the bead of adhesive includes silicone.