LIGHT EMITTING DEVICES AND METHODS

• US 20140217434A1
• Filed: 02/06/2014
• Published: 08/07/2014
• Est. Priority Date: 06/28/2010
• Status: Abandoned Application

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Hussell, Christopher P., Emerson, David T., Britt, Jeffrey Carl
• Application Number:
  US14/174,559
• Publication Number:
  US 20140217434A1
• Time in Patent Office: Days
• US Class Current: 257/89
• 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 component that is physically 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.

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

4. 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.

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

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

7. A method of providing a light emitting device, the method comprising:

providing a package body;

providing a leadframe within a portion of the package body, the leadframe comprising a first lead component and a second lead component;

providing a thermal component within a portion of the package body, the thermal component being physically isolated from the first and second lead components via portions of the package body; and

arranging a first group of LEDs over the thermal component, wherein the first group of LEDs comprises a first LED electrically connected in series to a second LED.

8. The method according to claim 7, further comprising providing a second group of LEDs electrically connected in parallel to the first group of LEDs.

9. The method according to claim 7, further comprising electrically connecting each of the first and second groups of LEDs to the first and second lead components.

10. The method according to claim 7, 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.

11. The method according to claim 7, wherein the package body comprises molded plastic.

12. The method according to claim 7, further comprising filling at least a portion of the package body with an encapsulant comprising a phosphor.

13. A light emitting device comprising:

a surface mount package body comprising an anode and a cathode; and

at least one string of serially connected light emitting diode (LED) chips provided between the anode and the cathode.

14. The light emitting device according to claim 13, wherein each LED chip in the string of LED chips is configured to emit a same color of light.

15. The light emitting device according to claim 13, wherein each LED chip in the string of LED chips is configured to emit at least two different colors of light.

16. The light emitting device according to claim 13, wherein the string of LED chips is configured to emit light that is red, blue, green, or any combination thereof.

17. The light emitting device according to claim 13, wherein the surface mount package body comprises a thermal component that is physically isolated from the anode and cathode.

18. The light emitting device according to claim 17, wherein the string of LED chips is directly attached to the thermal component.

19. The light emitting device according to claim 13, wherein the package body comprises a molded plastic body.

20. The light emitting device according to claim 13, further comprising at least two strings of serially connected LED chips.

21. The light emitting device according to claim 13, wherein the first and second strings are electrically connected in parallel between the anode and the cathode.

22. The light emitting device according to claim 13, further comprising an encapsulant disposed over the string of LED chips.

23. The light emitting device according to claim 22, wherein the encapsulant comprises silicone and a phosphoric material.

24. The light emitting device according to claim 22, wherein the encapsulant comprises silicone.

25. The light emitting device according to claim 13, wherein the package body comprises a cavity, and wherein the string of LED chips is mounted to a surface of the cavity.

26. The light emitting device according to claim 25, wherein the cavity comprises a reflective surface.

27. A method of providing a light emitting device, the method comprising:

providing a surface mount package body comprising an anode and a cathode;

providing one or more light emitting diode (LED) chips; and

serially connecting the LED chips between the anode and the cathode.

28. The method according to claim 27, wherein providing the one or more LED chips comprises providing chips configured to emit a same color of light.

29. The method according to claim 27, wherein providing the one or more LED chips comprises providing chips configured to emit at least two colors of light.

30. The method according to claim 27, wherein providing the one or more LED chips comprises providing LED chips configured to emit light that is red, blue, green, or any combination thereof.

31. The method according to claim 27, further comprising mounting the LED chips over a thermal component that is physically isolated from the anode and cathode.

32. The method according to claim 27, wherein providing the surface mount package body comprises molding a plastic body.

33. The method to claim 27, further comprising serially connecting the LED chips in at least two strings.

34. The method according to claim 33, wherein the two strings are electrically connected in parallel between the anode and the cathode.

35. The method according to claim 27, further comprising encapsulating the string of LED chips.

36. The method according to claim 27, further comprising mounting the string of LED chips within a cavity of the package body.