Light emitting device having a pluralilty of light emitting cells and package mounting the same

• US 8,536,612 B2
• Filed: 06/03/2011
• Issued: 09/17/2013
• Est. Priority Date: 12/14/2004
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Lee, Chung Hoon, Yves, Lacroix, Yoon, Hyung Soo, Lee, Young Ju
• Primary Examiner(s): Lee, Cheung
• Assistant Examiner(s): JOY, JEREMY J
• Application Number:
  US13/152,566
• Publication Number:
  US 20110233574A1
• Time in Patent Office: 837 Days
• Field of Search: 257/88, 257/43, 257/98, 257/77, 257/E33.045, 257/E29.068, 257/E21.002, 257/E33.013, 257/100, 438/34
• US Class Current: 257/99
• 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 25/0753 the devices being arranged next to each other
• 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 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding

Abstract

Disclosed is a light emitting device having a plurality of light emitting cells and a package having the same mounted thereon. The light emitting device includes a plurality of light emitting cells which are formed on a substrate and each of which has an N-type semiconductor layer and a P-type semiconductor layer located on a portion of the N-type semiconductor layer. The plurality of light emitting cells are bonded to a submount substrate. Accordingly, heat generated from the light emitting cells can be easily dissipated, so that a thermal load on the light emitting device can be reduced. Meanwhile, since the plurality of light emitting cells are electrically connected using connection electrodes or electrode layers formed on the submount substrate, it is possible to provide light emitting cell arrays connected to each other in series. Further, it is possible to provide a light emitting device capable of being directly driven by an AC power source by connecting the serially connected light emitting cell arrays in reverse parallel to each other.

Claims

1. A light emitting diode package, comprising:

a substrate;

a plurality of nitride semiconductor light emitting cells arranged on the substrate, a top surface of each of the plurality of nitride semiconductor light emitting cells comprising an n-type nitride semiconductor layer or an un-doped nitride semiconductor layer, a bottom surface of each of the plurality of nitride semiconductor light emitting cells comprising a p-type nitride semiconductor layer and a partially exposed n-type nitride semiconductor layer;

a first metal layer arranged between the substrate and each of the plurality of nitride semiconductor light emitting cells, the first metal layer contacting the bottom surface of each of the plurality of nitride semiconductor light emitting cells;

a second metal layer contacting the partially exposed n-type nitride semiconductor layers;

a molding member arranged on the nitride semiconductor light emitting cells;

a first bonding pad connected to the first metal layer of a first nitride semiconductor light emitting cell of the plurality of nitride semiconductor light emitting cells, the first bonding pad penetrating through the substrate;

a second bonding pad connected to the second metal layer of a second nitride semiconductor light emitting cell of the plurality of nitride semiconductor light emitting cells; and

a plurality of connection electrodes respectively electrically connecting the n-type nitride semiconductor layers and the p-type nitride semiconductor layers of adjacent nitride semiconductor light emitting cells,

wherein the first bonding pad is electrically connected to a first metal lead arranged outside of a region directly under the nitride semiconductor light emitting cells,

wherein the second bonding pad penetrates through the substrate,

wherein the second bonding pad is electrically connected to a second metal lead, and portions of the first bonding pad and the second bonding pad are disposed at the bottom surface of the substrate,

wherein the top surfaces of the nitride semiconductor light emitting cells are free from a growth substrate thereof,

wherein the molding member covers portions of the first metal lead and the second metal lead,

wherein the molding member covers side surfaces of the substrate, and

wherein the connection electrodes contact the substrate.

2. The light emitting device of claim 1, further comprising a passivation layer arranged between the substrate and the nitride semiconductor light emitting cells,

wherein the passivation layer comprises SiO₂, MgO, or SiN.

3. The light emitting device of claim 1, further comprising an additional first metal layer arranged between the first metal layer and the first bonding pad, wherein the additional first metal layer comprises Ti, Ni, Ag, Zn, Cd, Bi, Cu, Ge, Au, Sn, or Pb.

4. The light emitting device of claim 1, wherein the first metal layer comprises a reflective film.

5. The light emitting device of claim 3, further comprising an additional second metal layer.

6. The light emitting device of claim 1, wherein the second metal layer contacts the n-type nitride semiconductor layer or is adjacent to the p-type nitride semiconductor layer.

7. The light emitting device of claim 5, wherein the additional second metal layer comprises Ti, Ni, Ag, Zn, Cd, Bi, Cu, Ge, Au, Sn, or Pb.

8. The light emitting device of claim 5, wherein the additional second metal layer comprises an electrode layer.

9. The light emitting device of claim 1,

wherein the connection electrodes connect the nitride semiconductor light emitting cells in parallel.

10. The light emitting device of claim 1, wherein

the connection electrodes connect the nitride semiconductor light emitting cells in series.

11. The light emitting device of claim 3, wherein the additional first metal layer is arranged on the n-type nitride semiconductor layer, and connects the n-type nitride semiconductor layer to the bottom surface of the substrate.

12. The light emitting device of claim 1, further comprising a fluorescent substance disposed between the molding member and the plurality of nitride semiconductor light emitting cells.

13. The light emitting device of claim 1, further comprising a heat sink, wherein the substrate is arranged on the heat sink.

14. The light emitting device of claim 1, wherein the molding member comprises a lens shape.

15. A light emitting diode package, comprising:

a substrate;

a plurality of nitride semiconductor light emitting cells arranged on the substrate, a top surface of each of the plurality of nitride semiconductor light emitting cells comprising an n-type nitride semiconductor layer or an un-doped nitride semiconductor layer, a bottom surface of each of the plurality of nitride semiconductor light emitting cells comprising a p-type nitride semiconductor layer and a partially exposed n-type nitride semiconductor layer;

a passivation layer arranged between the substrate and each of the plurality of nitride semiconductor light emitting cells;

a first metal layer arranged between the substrate and each of the plurality of nitride semiconductor light emitting cells, the first metal layer contacting the bottom surface of each of the plurality of nitride semiconductor light emitting cells;

a molding member arranged on the nitride semiconductor light emitting cells;

a first bonding pad connected to the first metal layer of a first nitride semiconductor light emitting cell of the plurality of nitride semiconductor light emitting cells, the first bonding pad penetrating through the substrate;

a second bonding pad connected to a second metal layer of a second nitride semiconductor light emitting cell of the plurality of nitride semiconductor light emitting cells;

a plurality of connection electrodes respectively electrically connecting the n-type nitride semiconductor layers and the p-type nitride semiconductor layers of adjacent nitride semiconductor light emitting cells; and

a heat sink, wherein the substrate is arranged on the heat sink,

wherein the first bonding pad is electrically connected to a first metal lead arranged outside of a region directly under the nitride semiconductor light emitting cells,

wherein the second bonding pad penetrates through the substrate,

wherein the second bonding pad is electrically connected to a second metal lead, and portions of the first bonding pad and the second bonding pad are disposed at the bottom surface of the substrate,

wherein a top surface of the first bonding pad and a top surface of the second bonding pad are co-planer with a top surface of the substrate,

wherein the molding member covers portions of the first metal lead and the second metal lead,

wherein the molding member covers side surfaces of the substrate, and

wherein the connection electrodes contact the substrate.

16. A light emitting diode package, comprising:

a substrate;

a plurality of nitride semiconductor light emitting cells arranged on the substrate, a top surface of each of the plurality of nitride semiconductor light emitting cells comprising an n-type nitride semiconductor layer or an un-doped nitride semiconductor layer, a bottom surface of each of the plurality of nitride semiconductor light emitting cells comprising a p-type nitride semiconductor layer and a partially exposed n-type nitride semiconductor layer;

a first metal layer arranged between the substrate and each of the plurality of nitride semiconductor light emitting cells, the first metal layer contacting the bottom surface of each of the plurality of nitride semiconductor light emitting cells;

a second metal layer contacting the partially exposed n-type nitride semiconductor layers;

a molding member arranged on the nitride semiconductor light emitting cells;

a first bonding pad connected to the first metal layer of a first nitride semiconductor light emitting cell of the plurality of nitride semiconductor light emitting cells, the first bonding pad penetrating through the substrate;

a second bonding pad connected to the second metal layer of a second nitride semiconductor light emitting cell of the plurality of nitride semiconductor light emitting cells; and

a plurality of connection electrodes respectively electrically connecting the n-type nitride semiconductor layers and the p-type nitride semiconductor layers of adjacent nitride semiconductor light emitting cells,

wherein the first bonding pad is electrically connected to a first metal lead arranged outside of a region directly under the nitride semiconductor light emitting cells,

wherein the second bonding pad penetrates through the substrate,

wherein the second bonding pad is electrically connected to a second metal lead, and portions of the first bonding pad and the second bonding pad are disposed at the bottom surface of the substrate,

wherein the top surfaces of the nitride semiconductor light emitting cells are free from a growth substrate thereof,

wherein the molding member covers portions of the first metal lead and the second metal lead,

wherein the molding member covers side surfaces of the substrate, and

wherein the connection electrodes contact the substrate, but are not bonded thereto.