Light emitting devices and methods

• US 8,648,359 B2
• Filed: 09/08/2011
• Issued: 02/11/2014
• Est. Priority Date: 06/28/2010
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Hussell, Christopher P., Emerson, David T., Britt, Jeffrey C.
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US13/227,961
• Publication Number:
  US 20120127720A1
• Time in Patent Office: 887 Days
• Field of Search: 257/88, 362/249.02, 362/227, 298/25
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• 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 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• 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 2924/12032 Schottky diode
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/60 Reflective 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 33/642 characterized by the shape
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

Light emitting devices and methods such as light emitting diodes (LEDs) are disclosed for use in higher voltage applications. Variable arrangements of LEDs are disclosed herein. Arrangements can include one or more LED chips connected in series, parallel, and/or a combination thereof. LED chips can be disposed in a package body having at least one thermal element and one or more electrical components.

Claims

1. A light emitting device, the device comprising:

a package body;

a leadframe comprising a first lead component and a second lead component;

a thermal element that is thermally and electrically isolated from the first and second lead components via portions of the package body; and

a first group of LEDs arranged over the thermal component, wherein the first group of LEDs comprises a first LED electrically connected in series to a second LED; and

wherein the package body is formed about a portion of the thermal element and a portion of each of the first and second lead components.

2. The light emitting device according to claim 1, wherein the package body comprises a molded plastic body.

3. The light emitting device according to claim 1, wherein the first group of LEDs is electrically connected in parallel to a second group of LEDs.

4. The light emitting device according to claim 3, wherein the second group of LEDs comprises a preceding LED electrically connected in series to a subsequent LED.

5. The light emitting device according to claim 4, wherein the first group comprises LEDs arranged in a first zigzag configuration and the second group comprises LEDs arranged in a second zigzag configuration.

6. An arrangement of light emitting diodes (LEDs), the arrangement comprising:

a first group of LEDs comprising a first LED electrically connected in series to a second LED; and

a second group of LEDs;

wherein the first group of LEDs is electrically connected in parallel to the second group of LEDs; and

wherein the first and second groups of LEDs are electrically connected to first and second lead components.

7. The arrangement according to claim 6, wherein the second group of LEDs comprises a preceding LED electrically connected in series to a subsequent LED.

8. The arrangement according to claim 6, wherein the first and second groups of LEDs are arranged over a thermal element.

9. The arrangement according to claim 8, comprising a package body molded about a portion of each of the first and second lead components wherein the package body is molded about a lateral protrusion of the thermal element, the package body forming a cavity disposed about the first and second groups of LEDs.

10. The arrangement according to claim 9, wherein the package body comprises encapsulant in at least a portion of the cavity.

11. The arrangement according to claim 9, wherein the package body comprises a recess formed in a bottom surface of the package body.

12. A method of arranging light emitting diodes (LEDs) within a package, the method comprising:

providing a package body;

providing a first group of LEDs wherein a first LED in the first group is electrically connected in series to a second LED in the first group;

providing a second group of LEDs;

electrically connecting the first group of LEDs in parallel with the second group of LEDs within the package body; and

encapsulating at least some of the LEDs in the first or second groups of LEDs.

13. The method according to claim 12, wherein providing the second group of LEDs comprises providing a second group of LEDs comprising a preceding LED electrically connected in series to a subsequent LED.

14. The method according to claim 12, further comprising electrically connecting each of the first and second groups of LEDs to first and second lead components.

15. The method according to claim 14, further comprising arranging the first and second group of LEDS within a package body such that each of the first and second groups comprises a zigzag series configuration.

16. The method according to claim 15, wherein the package body comprises molded plastic.

17. The method according to claim 16, further comprising filling at least a portion of the package body with an encapsulant comprising a phosphor.