Light emitting device

• US 9,018,656 B2
• Filed: 02/23/2010
• Issued: 04/28/2015
• Est. Priority Date: 02/24/2009
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Murai, Akihiko, Yasuda, Masaharu, Iwahashi, Tomoya, Yamae, Kazuyuki
• Primary Examiner(s): SANDVIK, BENJAMIN P
• Application Number:
  US13/201,853
• Publication Number:
  US 20110297989A1
• Time in Patent Office: 1,890 Days
• Field of Search: 257/79, 257/98, 257/103
• US Class Current: 257/98
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• 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 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

The light emitting device comprises a mounting substrate and an LED chip which comprises an n-type nitride semiconductor layer, a nitride light emission layer on the n-type nitride semiconductor layer, p-type nitride semiconductor layer on the nitride light emission layer, an anode electrode opposite of the nitride light emission layer from the p-type nitride semiconductor layer, and a cathode electrode on the n-type nitride semiconductor layer. The mounting substrate has a patterned conductor which is connected to the cathode electrode through a bump and also connected to the anode electrode through a bump. The LED chip further comprises one or more dielectric layer between the p-type nitride semiconductor layer and the anode electrode to have an arrangement which resembles an island. The p-type nitride semiconductor layer has a first region which is overlapped with the bump. The dielectric layer is not formed within the first region.

Claims

1. A light emitting device comprising:

an LED chip and a mounting substrate,

said LED chip comprising an n-type nitride semiconductor layer, a nitride light emission layer, a p-type nitride semiconductor layer, an anode electrode, and a cathode electrode,

said n-type nitride semiconductor layer having a first surface,

said nitride light emission layer being disposed on said first surface of said n-type nitride semiconductor layer,

said p-type nitride semiconductor layer being disposed on said nitride light emission layer,

said anode electrode being opposite of said nitride light emission layer from said p-type nitride semiconductor layer and covering said p-type nitride semiconductor layer,

said cathode electrode being disposed on said first surface of said n-type nitride semiconductor layer,

said mounting substrate being configured to mount said LED chip,

said mounting substrate having a first patterned conductor which is coupled to said cathode electrode through a cathode bump and a second patterned conductor which is electrically and physically connected to anode bumps, said anode bumps being electrically and physically connected to said anode electrode,

said LED chip comprising dielectric layers which have an arrangement which resembles an island and a light reflective conductive film covering said dielectric layers,

said dielectric layers having a refractive index which is smaller than a refractive index of said p-type nitride semiconductor layer,

said dielectric layers being located between said p-type nitride semiconductor layer and said anode electrode,

said p-type nitride semiconductor layer having first regions which are overlapped with said anode bumps in a planer view, respectively,

said dielectric layers being not overlapped with said first regions,

said light reflective conductive film being located between said anode electrode and said dielectric layers, and

said anode electrode does not penetrate said light reflective conductive film.

2. The light emitting device as set forth in claim 1, wherein

said LED chip further comprises a transparent conductive film,

said transparent conductive film being disposed between the said p-type nitride semiconductor layer and said anode electrode,

said transparent conductive film having a refractive index which is lower than the refractive index of said p-type nitride semiconductor layer,

said light reflective conductive film being disposed between said transparent conductive film and said anode electrode,

said dielectric layers being partially formed on said transparent conductive film,

said dielectric layers having the arrangement which resembles the island, and

said dielectric layers being formed between said transparent conductive film and said light reflective conductive film.

3. The light emitting device as set forth in claim 1, wherein

each of said first regions is a plane which is perpendicular to a thickness direction of said p-type nitride semiconductor layer,

said plane having a circular shape,

said first regions being overlapped with said anode bumps, respectively, in the thickness direction of said p-type nitride semiconductor layer.

4. The light emitting device as set forth in claim 2, wherein

each of said first regions is a plane which is perpendicular to a thickness direction of said p-type nitride semiconductor layer,

said plane having a circular shape,

said first regions being overlapped with said anode bumps, respectively, in the thickness direction of said p-type nitride semiconductor layer.

5. The light emitting device as set forth in claim 1, wherein each of said dielectric layers has a two-layer structure.

6. The light emitting device as set forth in claim 1, wherein each of said dielectric layers includes a silicon oxide layer and a zirconium oxide layer.

7. The light emitting device as set forth in claim 1, wherein each of said first regions is surrounded by said dielectric layers.

8. The light emitting device as set forth in claim 1, wherein said dielectric layers are arranged to be spaced from an adjacent dielectric layer by the same distance.

9. The light emitting device as set forth in claim 7, wherein said dielectric layers are arranged to be spaced from an adjacent dielectric layer by the same distance.

10. A light emitting device comprising:

an LED chip and a mounting substrate,

said LED chip comprising an n-type nitride semiconductor layer, a nitride light emission layer, a p-type nitride semiconductor layer, an anode electrode, and a cathode electrode,

said n-type nitride semiconductor layer having a first surface,

said nitride light emission layer being disposed on said first surface of said n-type nitride semiconductor layer,

said p-type nitride semiconductor layer being disposed on said nitride light emission layer,

said anode electrode being opposite of said nitride light emission layer from said p-type nitride semiconductor layer and covering said p-type nitride semiconductor layer,

said cathode electrode being disposed on said first surface of said n-type nitride semiconductor layer,

said mounting substrate being configured to mount said LED chip,

said mounting substrate having a first patterned conductor which is coupled to said cathode electrode through a cathode bump and a second patterned conductor which is electrically and physically connected to anode bumps, said anode bumps being electrically and physically connected to said anode electrode,

said LED chip comprising a dielectric layer having openings and a light reflective conductive film covering said dielectric layer,

said dielectric layer having a refractive index which is smaller than a refractive index of said p-type nitride semiconductor layer,

said dielectric layer being located between said p-type nitride semiconductor layer and said anode electrode,

in a planer view, said anode bumps overlapping with said openings, respectively, and not overlapping with said dielectric layer,

said anode electrode not directly contacting said p-type nitride semiconductor layer,

said light reflective conductive film being located between said dielectric layer and said anode electrode, and

said anode electrode does not penetrate said light reflective conductive film.

11. The light emitting device as set forth in claim 10, wherein each of said dielectric layers has a two-layer structure.

12. The light emitting device as set forth in claim 10, wherein each of said dielectric layers includes a silicon oxide layer and a zirconium oxide layer.