LIGHT-EMITTING DEVICE AND BACKLIGHT INCLUDING LIGHT-EMITTING DEVICE

• US 20170040301A1
• Filed: 08/01/2016
• Published: 02/09/2017
• Est. Priority Date: 08/04/2015
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: ONO, Keiko, MARUYAMA, Tomokazu, YAMAMOTO, Atsushi, YAMAMOTO, Saiki, MORIKAWA, Takeshi, AKAGAWA, Seitaro
• Granted Patent: US 10,529,695 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• 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 25/0753 the devices being arranged next to each other
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• 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

Abstract

The light-emitting device includes a first light-emitting element having an emission peak wavelength of 430 nm or more and less than 490 nm, a second light-emitting element having an emission peak wavelength of 490 nm or more and 570 nm or less, a support body at which the first light-emitting element and the second light-emitting element are disposed, and a light-transmissive member containing a red phosphor and covering the first light-emitting element and the second light-emitting element. A content density of the red phosphor in the light-transmissive member in a space between the first and second light-emitting elements is higher in a part below an upper surface of the second light-emitting element than in a part above the upper surface thereof.

Claims

1. A light-emitting device, comprising:

a first light-emitting element having an emission peak wavelength of 430 nm or more and less than 490 nm;

a second light-emitting element having an emission peak wavelength of 490 nm or more and 570 nm or less;

a support body at which the first light-emitting element and the second light-emitting element are disposed; and

a light-transmissive member containing a red phosphor and covering the first light-emitting element and the second light-emitting element, wherein

a content density of the red phosphor in the light-transmissive member located in a space between the first and second light-emitting elements is higher in a part below an upper surface of the second light-emitting element than in a part above the upper surface thereof.

2. The light-emitting device according to claim 1, wherein the red phosphor is at least one of a phosphor with the composition represented by the general formula (I) below and a phosphor with the composition represented by

3.5MgO.0.5MgF₂.GeO₂:

Mn⁴⁺;

A₂MF₆;

Mn⁴⁺ 

 

(I)

where, in the general formula (I), A is at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH⁴⁺; and

M is at least one element selected from the group consisting of Group 4 elements and Group 14 elements.

3. The light-emitting device according to claim 1, wherein the first and second light-emitting elements are alternately arranged in a longitudinal direction and a lateral direction at an element mounting surface of the support body.

4. The light-emitting device according to claim 1, wherein a ratio of a light output from the second light-emitting element to that from the first light-emitting element is in a range of 0.3 or more and 0.7 or less.

5. The light-emitting device according to claim 1, wherein an upper surface of the second light-emitting element is positioned closer to a light extraction surface of the light-emitting device, compared to an upper surface of the first light-emitting element.

6. The light-emitting device according to claim 1, wherein the first light-emitting element and the second light-emitting element are nitride semiconductor light-emitting elements.

7. The light-emitting device according to claim 1, wherein one of positive and negative electrodes of the first light-emitting element is connected to one of positive and negative electrodes of the second light-emitting element via a wire.

8. A backlight comprising:

the light-emitting device according to claim 1; and

a light guide plate having a light input portion at a side surface thereof, wherein

the light extraction surface of the light-emitting device and the light input portion are disposed facing each other.