Light emitting diode device having advanced light extraction efficiency and preparation method thereof

• US 20070018186A1
• Filed: 07/18/2006
• Published: 01/25/2007
• Est. Priority Date: 07/19/2005
• Status: Abandoned Application

• Current Assignee: Hanbeam Co., Ltd.
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Yu, Min, Choi, Min Ho, Lee, Jae, Kang, Jong, Shin, Hyun, Ha, Duk, Shin, Bu
• Application Number:
  US11/488,183
• Publication Number:
  US 20070018186A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83001 involving a temporary auxiliary member not forming part of the bonding apparatus
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 2924/12036 PN diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/15787 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

Disclosed is an LED device, a method for manufacturing the same, and a light emitting apparatus having the same. The LED device includes (a) a light emitting diode unit and (b) an adjustment layer laminated on a light emitting surface of the light emitting diode unit, a fine pattern having being formed on the adjustment layer by repeating a shape in a light emission direction. The adjustment layer is (i) at least one layer formed by aligning transparency adjustment particles having a shape or (ii) a polymer film layer having a fine pattern imprinted on the polymer film layer so as to adjust transparency. A fine pattern adjustment layer having various shapes and an adjustable size is introduced on the light emitting surface of the LED unit. As a result, the light extraction efficiency of the surface of the LED unit improves together with ease of manufacturing and secured uniformity.

Claims

1. A light emitting diode device comprising:

(a) a light emitting diode unit and

(b) an adjustment layer laminated on a light emitting surface of the light emitting diode unit, a fine pattern having being formed on the adjustment layer by repeating a shape in a light emission direction, wherein the adjustment layer is

(i) at least one layer formed by aligning transparency adjustment particles having a shape or

(ii) a polymer film layer having a fine pattern imprinted on the polymer film layer so as to adjust transparency.

2. The light emitting diode device as claimed in claim 1, wherein the adjustment layer has a refractive index larger than a refractive index of a molding portion introduced on the light emitting diode unit.

3. The light emitting diode device as claimed in claim 1, wherein each pattern element formed on the adjustment layer has a shape of a sphere, a cone, or a polyhedron with at least four faces.

4. The light emitting diode device as claimed in claim 1, wherein a ratio d/w of depth d to line width w of each pattern element formed on the adjustment layer is equal to or larger than 1.

5. The light emitting diode device as claimed in claim 1, wherein the adjustment layer has a thickness of 500-10,000 mm.

6. The light emitting diode device as claimed in claim 1, wherein the adjustment layer (i) is a single layer formed by transparency adjustment particles having a shape of a sphere, a cone, or a polyhedron with at least four faces.

7. The light emitting diode device as claimed in claim 1, wherein the transparency adjustment particles are at least one kind of metal oxide selected from the group consisting of titanium, tungsten, zinc, aluminum, indium, and tin oxide.

8. The light emitting diode device as claimed in claim 1, wherein the transparency adjustment particles comprise white particles or at least one kind of phosphor selected from the group consisting of blue phosphor, green phosphor, yellow phosphor, and red phosphor.

9. The light emitting diode device as claimed in claim 1, wherein the transparency adjustment particles have a size of 10 nm-100 μ

m.

10. The light emitting diode device as claimed in claim 1, wherein the adjustment layer (ii) is formed by hardening a UV-curable or heat-curable polymer.

11. The light emitting diode device as claimed in claim 10, wherein the UV-curable or heat-curable polymer is at least one kind of resin selected from the group consisting of epoxy resin, urea resin, phenolic resin, silicon resin, and acrylic resin.

12. The light emitting diode device as claimed in claim 1, wherein the adjustment layer (ii) contains transparency adjustment particles inside the polymer film layer.

13. The light emitting diode device as claimed in claim 12, wherein a polymer film adjustment layer containing the transparency adjustment particles is obtained by compressing a mixture of the transparency adjustment particles and a transparent polymer with a stamp having a fine pattern carved on a surface and curing the mixture with UV rays or heat so that a fine pattern is imprinted.

14. The light emitting diode device as claimed in claim 12, wherein a polymer film adjustment layer containing the transparency adjustment particles is obtained by using transparency adjustment particles having a size smaller than half a light emission wavelength (λ

/2) and a transparent polymer so that a fine pattern having a size larger than half the light emission wavelength (λ

/2) is formed.

15. The light emitting diode device as claimed in claim 1, wherein the light emitting diode unit contains a gallium nitride-based compound.

16. The light emitting diode device as claimed in claim 1, wherein the light emitting diode unit is formed in a laser liftoff method.

17. The light emitting diode device as claimed in claim 1, wherein the light emitting diode unit has a p-type layer, an active layer, an n-type layer, and a transparency adjustment layer formed on top of the n-type layer.

18. A light emitting apparatus having the light emitting diode device as defined in claim 1.

19. A method for manufacturing a light emitting diode device having a transparency adjustment layer formed on a light emitting surface of a light emitting diode unit, the method comprising the steps of:

(a) applying a slurry to a substrate, the slurry containing a transparent polymer or the polymer and transparency adjustment particles;

(b) compressing a surface of the substrate, the slurry having been applied to the surface, by using a stamp having a fine pattern carved on a surface;

(c) shaping a fine pattern by means of hardening based on UV rays or heat and separating a film from the stamp, a fine pattern having been imprinted on the film; and

(d) attaching a polymer film, the fine pattern having been imprinted on the polymer film, or a film containing the polymer and the transparency adjustment particles to a light emitting surface of a light emitting diode unit.

20. A method for manufacturing a light emitting diode device having a transparency adjustment layer formed on a light emitting surface of a light emitting diode unit, the method comprising the steps of:

(a) preparing a transparent polymer substrate with or without transparency adjustment particles;

(b) compressing a surface of the substrate by using a stamp having a fine pattern carved on a surface;

(c) shaping a fine pattern by means of hardening based on UV rays or heat so that the fine pattern is imprinted on a surface of the substrate; and

(d) attaching the polymer substrate to a light emitting surface of a light emitting diode unit, the substrate having the fine pattern imprinted on the surface and containing a polymer or the polymer and the transparency adjustment particles.

21. A polymer film or substrate with or without transparency adjustment particles, comprising:

(a) a film or substrate having a fine pattern imprinted on a surface so as to adjust a surface structure of a light emitting diode unit, the film or substrate containing a polymer or the polymer and transparency adjustment particles, and

(b) a polymer film with no fine pattern or a release film removably attached to a surface of the substrate.