Light emitting device, display apparatus with an array of light emitting devices, and display apparatus method of manufacture

• US 6,800,996 B2
• Filed: 08/14/2003
• Issued: 10/05/2004
• Est. Priority Date: 07/21/2000
• Status: Expired due to Term

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Izuno, Kunihiro, Nagai, Yoshifumi, Fujiwara, Yuichi
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US10/640,672
• Publication Number:
  US 20040046222A1
• Time in Patent Office: 418 Days
• Field of Search: 313/512, 313/498, 313/499, 313/112, 313/113, 313/116, 313/52-504, 315/169.3, 345/36, 345/45, 345/76, 428/690, 428/917, 362/355, 362/310, 362/311, 362/800, 257/89, 257/103, 257/98-101, 257/17, 257/72-74
• US Class Current: 313/512
• 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 24/45 of an individual wire connector
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/12041 LED
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light emitting device and display apparatus using a plurality of light emitting devices can drastically reduce contrast loss due to light from an external source. The light emitting device has (a) light emitting chip(s) and a first layer covering the light emitting chip(s). A second layer including a light scattering material is provided at least over the first layer, and the surface of second layer has a plurality of protrusions which follow the topology of the light scattering material. The display apparatus is formed by disposing these light emitting devices in an array on a substrate.

Claims

1. A light emitting device comprising:

a package having a cavity which is formed by side-walls of said package; and

a light emitting chip disposed on a surface at the base of the cavity;

wherein, a layer including light scattering material is formed at least over upper surfaces of the side-walls of said package, and

wherein a film thickness of the layer including the light scattering material is less than a particle diameter of the light scattering material, and at least a surface of the layer including the light scattering material formed over the upper surfaces of the side-walls of said package has protrusions that follow the topology of the light scattering material.

2. The light emitting device according to claim 1, wherein the light scattering material includes at least one of fluorescent material and pigment.

3. The light emitting device according to claim 2, wherein the light scattering material is made up of at least one of the fluorescent material and the pigment covered with transparent material.

4. The light emitting device according to claim 3, wherein the transparent material is made of organic material.

5. The light emitting device according to claim 2, wherein the fluorescent material is a yttrium-aluminum oxide family of fluorescent materials.

6. The light emitting device according to claim 2, wherein the fluorescent material is selected from the group consisting of a yttrium-aluminum oxide family of fluorescent materials and a fluorescent material wherein part or all of the yttrium in the yttrium-aluminum oxide family is replaced by at least one other element.

7. The light emitting device according to claim 5, wherein the yttrium in the yttrium-aluminum oxide family of fluorescent materials includes at least one of the elements selected from the group consisting of Ba, Sr, Mg, Ca, and Zn, or the yttrium in the yttrium-aluminum oxide family of fluorescent materials includes Si.

8. The light emitting device according to claim 1, wherein at least the film thickness of the layer including the light scattering material formed over the upper surfaces of the side-walls of said package is 1-10 μ

m, and the particle diameter of the light scattering material therein is 10-20 μ

m.

9. The light emitting device according to claim 6, wherein the at least one element which replaces part or all of the yttrium in the yttrium-aluminum oxide family of fluorescent materials is selected from the group consisting of Lu, Sc, La, Gd, and Sm.