LED package having an array of light emitting cells coupled in series

• US 8,076,680 B2
• Filed: 10/26/2005
• Issued: 12/13/2011
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Lee, Chung Hoon, Lee, Keon Young, Kim, Hong San, Kim, Dae Won, Choi, Hyuck Jung
• Primary Examiner(s): Nguyen, Cuong Q
• Assistant Examiner(s): TRAN, TRANG Q
• Application Number:
  US11/908,112
• Publication Number:
  US 20090267085A1
• Time in Patent Office: 2,239 Days
• Field of Search: 257/88, 257 98-100, 257/712
• 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 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• 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 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• 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

Abstract

Disclosed is a light emitting diode (LED) package having an array of light emitting cells coupled in series. The LED package comprises a package body and an LED chip mounted on the package body. The LED chip has an array of light emitting cells coupled in series. Since the LED chip having the array of light emitting cells coupled in series is mounted on the LED package, it can be driven directly using an AC power source.

Claims

1. A light emitting diode (LED), comprising:

a package body;

a submount comprising a plurality of recesses and protrusions and electrode patterns being formed corresponding to each recess and protrusion of the submount; and

light emitting cells bonded to the respective electrode patterns of the submount to couple one another in series according to the recess and the protrusion of the electrode patterns,

wherein each of the light emitting cells comprises a first-type semiconductor layer and a second-type semiconductor layer interposed between a portion of the first-type semiconductor layer and the electrode patterns, and

wherein the submount is interposed between the light emitting cells and the package body.

2. The LED of claim 1, wherein the package body comprises a printed circuit board with lead electrodes, and the submount is electrically connected to the lead electrodes.

3. The LED of claim 1, further comprising:

a pair of lead frames spaced apart from each other; and

a heat sink,

wherein the package body supports the pair of lead frames and the heat sink, and comprises an opening for exposing a portion of each of the lead frames and an upper portion of the heat sink, and the submount is mounted on the heat sink.

4. The LED claim 1, wherein the package body comprises ceramic.

5. The LED of claim 1, further comprising:

a rectification bridge unit configured to apply rectified power to the light emitting cells coupled to one another in series.

6. The LED of claim 1, further comprising:

an encapsulant or molding member covering the light emitting cells, and wherein the molding member comprises a first molding member and a second molding member, the second molding member having a higher hardness than the first molding member.

7. The LED of claim 6, wherein the second molding member contains a phosphor.

8. The LED of claim 1, wherein the submount further comprises a submount substrate having a plurality of N-regions and P-regions defined thereon, and a dielectric film formed on the surface of the submount substrate, and wherein each of the electrode patterns connects an adjacent N-region and P-region to each other.

9. The LED of claim 8, wherein the first-type semiconductor layer comprises a P-type semiconductor layer and the second-type semiconductor layer comprises an N-type semiconductor layer.

13. The LED of claim 9, wherein the P-type semiconductor layer is coupled to the recess of the submount and the N-type semiconductor layer is coupled to the protrusion of the submount.

14. The LED of claim 9, further comprising:

a P-type metal bumper disposed between the electrode pattern corresponding to the recess and a P-type electrode layer disposed to the P-type semiconductor layer; and

an N-type metal bumper disposed between the electrode pattern corresponding to the protrusion and the N-type semiconductor layer.

15. The LED of claim 3, wherein the submount is interposed between the light emitting cells and the heat sink.

19. The LED of claim 8, wherein the submount is mounted on the heat sink.

10. A light emitting diode (LED), comprising:

a package body;

a submount comprising a plurality of recesses and a protrusions and a plurality of electrode patterns being formed corresponding to each recess and protrusion of the submount;

light emitting cells bonded to the electrode patterns to couple one another in series according to each recess and the protrusion of the electrode patterns; and

a bridge rectifier mounted on the package body and being arranged between an alternating current (AC) power source and the light emitting cells, wherein a portion of the light emitting cells is connected to the bridge rectifier.

11. The LED of claim 10, further comprising:

at least two arrays of light emitting cells connected in reverse parallel and the AC power is configured to operate a rectification.

12. The LED of claim 10, wherein each light emitting cell comprises a first-type semiconductor layer and a second-type semiconductor layer interposed between a portion of the first-type semiconductor layer and the electrode patterns, and

wherein each light emitting cell comprises a surface exposed to an encapsulant or molding member, the exposed surface being opposite to, and not facing, the submount, and the exposed surface comprises the first-type semiconductor layer or a buffer layer.

16. The LED of claim 11, wherein both ends of the two arrays of light emitting cells are electrically connected, and light emitting cells are driven by currents flowing in opposite directions, and wherein, each anode and cathode of the each of the light emitting cells in each array are respectively arranged in opposite directions.

17. The LED of claim 10 further comprising:

a serial array of light emitting cells and a bridge rectifier comprising diode cells arranged between the AC power source and the serial array of light emitting cells, and between a ground and the serial array, wherein an anode terminal of the serial array of light emitting cells is connected to a node between one set of the diode cells, and a cathode terminal of the serial array is connected to a node between another set of the diode cells.

18. The LED of claim 17 further comprising:

a terminal of the AC power source connected to a node between the one set of the diode cells, and the ground is connected to a node between the another set of the diode cells.