Light emitting device packages with improved heat transfer

• US 9,123,874 B2
• Filed: 12/02/2013
• Issued: 09/01/2015
• Est. Priority Date: 01/12/2009
• Status: Active Grant

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Hussell, Christopher P., Joo, Sung Chul
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US14/094,341
• Publication Number:
  US 20140159088A1
• Time in Patent Office: 638 Days
• Field of Search: 257/88, 257/99, 257/E21.499, 257/E33.056
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/642 characterized by the shape
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

Packages containing one or more light emitting devices, such as light emitting diodes (LEDs), are disclosed. In one embodiment, LED package can include a thermal element having improved solder reliability to improve heat dissipation capacity of the LED package. LED package can include a molded plastic body having one or more LEDs attached to one or more electrical elements. The LEDs can be connected to an upper surface of the thermal element. The thermal element can include a bottom surface which can extend further away in distance from a body of the LED package than a bottom surface of the electrical element. This configuration can result in an improved connection between the LED package and an external circuitry source, thereby increasing heat transfer ability of the LED package.

Claims

1. A light emitting device package, the package comprising:

a body comprising at least a portion of a thermal element and at least a portion of an electrical element, the electrical element contained between lateral sides of the body without extending beyond the lateral sides of the body;

at least one light emitting device mounted on a top surface of the body; and

both the thermal element and the electrical element extending from a bottom surface of the body wherein a bottom surface of the electrical element extends away from the body a first distance, and a bottom surface of the thermal element extends away from the body a second distance that is greater than the first distance.

2. The light emitting device package according to claim 1, further comprising a lens.

3. The light emitting device package according to claim 1, wherein the second distance is greater than the first distance by from about 0 μ

m to about 100 μ

m.

4. The light emitting device package according to claim 1, wherein the second distance is greater than the first distance by greater than about 100 μ

m.

5. The light emitting device package according to claim 1, wherein the body comprises an insulating material.

6. The light emitting device package of claim 1, wherein the electrical element extends to a first plane and the thermal element extends to a second plane which is lower than the first plane.

7. The light emitting device package of claim 1, wherein the body comprises a reflector cavity.

8. A light emitting device package, the package comprising:

a body comprising at least a portion of a thermal element and at least a portion of an electrical element, the electrical element and the thermal element both contained between lateral sides of the body without extending beyond the lateral sides of the body;

at least one light emitting device thermally connected with the thermal element; and

both the thermal element and the electrical element extending from a bottom surface of the body wherein a bottom surface of the electrical element extends away from the body a first distance, and a bottom surface of the thermal element extends away from the body a second distance that is greater than the first distance.

9. The light emitting device package according to claim 8, further comprising a lens.

10. The light emitting device package according to claim 8, wherein the second distance is greater than the first distance by from about 0 μ

m to about 100 μ

m.

11. The light emitting device package according to claim 8, wherein the second distance is greater than the first distance by greater than about 100 μ

m.

12. The light emitting device package according to claim 8, wherein the body comprises an insulating material.

13. The light emitting device package of claim 8, wherein the electrical element extends to a first plane and the thermal element extends to a second plane which is lower than the first plane.

14. The light emitting device package of claim 8, wherein the body comprises a reflector cavity.

15. A light emitting device package, the package comprising:

a body comprising a first surface and a second surface;

at least one light emitting device mounted on the first surface of the body;

an electrical element contained between lateral sides of the body without extending beyond the lateral sides of the body, wherein at least a portion of the electrical element is exposed on the second surface of the body;

the electrical element having an electrical element bottom surface that is disposed along a first plane; and

a thermal element with a thermal element bottom surface that is disposed along a second plane that is different from the first plane.

16. The light emitting device package of claim 15, wherein the portion of the electrical element exposed on the second surface is flush with the second surface.

17. The light emitting device package of claim 15, wherein the portion of the electrical element exposed on the second surface extends away from the second surface a distance that is less than a distance the thermal element extends away from the second surface.

18. A light emitting device package, the package comprising:

a body comprising a first surface and a second surface;

at least one light emitting device electrically connected to an anode and a cathode on the first surface of the body;

at least one electrical element on the second surface of the body that is electrically connected to at least one of the anode and cathode;

a thermal element on the second surface of the body; and

wherein the at least one electrical element extends away from the second surface of the body a first distance and the thermal element extends away from the second surface of the body a second distance that is greater than the first distance.