Light emitting unit and display device

• US 8,686,447 B2
• Filed: 02/22/2012
• Issued: 04/01/2014
• Est. Priority Date: 03/01/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tomoda, Katsuhiro, Hirao, Naoki, Biwa, Goshi
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): NGUYEN, SOPHIA T
• Application Number:
  US13/402,137
• Publication Number:
  US 20120223345A1
• Time in Patent Office: 769 Days
• Field of Search: 257/88, 257/89, 257/93, 257/98, 257/95, 257/97, 257/99, 257/100, 345/690
• US Class Current: 257/89
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A light emitting unit including plural kinds of light emitting elements with different light emitting wavelengths, wherein, among the light emitting elements, at least one kind of light emitting element includes a semiconductor layer configured by laminating a first conductive layer, an active layer and a second conductive layer and having a side surface exposed by the first conductive layer, the active layer and the second conductive layer; a first electrode electrically connected to the first conductive layer; a second electrode electrically connected to the second conductive layer; a first insulation layer contacting at least an exposed surface of the active layer in the surface of the semiconductor layer; and a metal layer contacting at least a surface, which is opposite to the exposed surface of the active layer, in the surface of the first insulation layer, and electrically separated from the first electrode and the second electrode.

Claims

1. A light emitting unit comprising:

plural kinds of light emitting elements with different light emitting wavelengths, wherein, among the plural kinds of light emitting elements, at least a first light emitting element includes;

a semiconductor layer configured by laminating a first conductive layer, an active layer and a second conductive layer and having an exposed side surface of the first conductive layer, the active layer and the second conductive layer;

a first electrode electrically connected to the first conductive layer;

a second electrode electrically connected to the second conductive layer;

a first insulation layer contacting at least the exposed side surface of the active layer in the semiconductor layer and contacting at least a portion of a back surface of the first electrode;

a metal layer contacting at least a surface of the first insulating layer, which is opposite to the exposed side surface of the active layer, wherein the metal layer is electrically separated from the first electrode and the second electrode and a peripheral region of the metal layer fully extends beyond an edge of the first electrode and is parallel to the first electrode;

a second insulation layer formed over at least the peripheral region of the metal layer; and

a pad electrode electrically connected to an exposed region of the back surface of the first electrode and formed to extend beyond an edge of the first insulation layer and an edge of the peripheral region of the metal layer.

2. The light emitting unit according to claim 1, wherein the first insulation layer and the metal layer cover at least the entire side surface.

3. The light emitting unit according to claim 2, wherein the first insulation layer is formed by CVD (Chemical Vapor Deposition), deposition, or sputtering.

4. The light emitting unit according to claim 1, wherein the first electrode is a metal electrode that contacts a first surface of the first conductive layer, wherein the first surface is a side of the first conductive layer that is opposite to the active layer, and

wherein the first insulation layer and the metal layer extend from the side surface to a region over the first electrode.

5. The light emitting unit according to claim 4, wherein a first part of the first insulation layer that extends over the first electrode extends beyond the metal layer.

6. The light emitting unit according to claim 5, wherein the pad electrode further extends over an edge of the second insulation layer.

7. The light emitting unit according to claim 5, wherein the pad electrode physically contacts the exposed region of the first electrode.

8. The light emitting unit according to claim 1, wherein the plural kinds of light emitting elements include a light emitting element emitting a blue light, a light emitting element emitting a green light and a light emitting element emitting a red light, and

wherein, among these three kinds of light emitting elements, at least the light emitting element emitting a blue color and the light emitting element emitting a green light have the semiconductor layer, the first electrode, the second electrode, the first insulation layer and the metal layer.

9. The light emitting unit according to claim 1, further comprising an insulating body for surrounding each light emitting element by the same member.

10. A display device comprising:

a display panel having a plurality of light emitting units; and

a driving circuit for driving each light emitting unit based on an image signal,

wherein each light emitting unit has plural kinds of light emitting elements with different light emitting wavelengths, and

wherein, among the plural kinds of light emitting elements, at least a first light emitting element includes;

a semiconductor layer configured by laminating a first conductive layer, an active layer and a second conductive layer and having an exposed side surface of the first conductive layer, the active layer and the second conductive layer;

a first electrode electrically connected to the first conductive layer;

a second electrode electrically connected to the second conductive layer;

a first insulation layer contacting at least the exposed side surface of the active layer in the semiconductor layer and contacting at least a portion of a back surface of the first electrode;

a metal layer contacting at least a surface of the first insulating layer, which is opposite to the exposed side surface of the active layer, wherein the metal layer is electrically separated from the first electrode and the second electrode and a peripheral region of the metal layer fully extends beyond an edge of the first electrode and is parallel to the first electrode;

a second insulation layer formed over at least the peripheral region of the metal layer; and

a pad electrode electrically connected to an exposed re ion of the back surface of the first electrode and formed to extend beyond an edge of the first insulation layer and an edge of the peripheral region of the metal layer.

11. The display device of claim 10, wherein the display panel comprises:

a mounting substrate on which are mounted the plurality of light emitting units; and

a transparent substrate disposed adjacent to the mounting substrate.

12. The display device of claim 11, further comprising a scattering surface disposed across a display region of the display panel.

13. The display device of claim 10, wherein the first insulation layer and the metal layer cover at least the entire side surface.

14. The display device of claim 10, wherein the first electrode is a metal electrode that contacts a first surface of the first conductive layer, wherein the first surface is a side of the first conductive layer that is opposite to the active layer, and

wherein the first insulation layer and the metal layer extend from the side surface to a region over at least a portion of the first electrode.

15. The display device of claim 14, wherein a first part of the first insulation layer that extends over the first electrode extends beyond the metal layer.

16. The display device of claim 15, wherein the pad electrode further extends over an edge of the second insulation layer.

17. The display device of claim 16, wherein the pad electrode and metal layer form a constriction in the second insulation layer adjacent the edge of the peripheral region of the metal layer.

18. The display device of claim 10, wherein the plural kinds of light emitting elements include a light emitting element emitting a blue light, a light emitting element emitting a green light and a light emitting element emitting a red light, and

wherein, among these three kinds of light emitting elements, at least the light emitting element emitting a blue color and the light emitting element emitting a green light have the semiconductor layer, the first electrode, the second electrode, the first insulation layer and the metal layer.