Light-emitting device

Patent metadata

Field	Value
Publication number	US-11637226-B2
Application number	US-202117302248-A
Country	US
Kind code	B2
Filing date	Apr 28, 2021
Priority date	May 31, 2017
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A light-emitting device includes: a set of layers including (i) a light-transmissive member having a top surface, a bottom surface, and a lateral surface contiguous with the top surface and the bottom surface, (ii) a first phosphor layer disposed below the bottom surface, and (iii) a dielectric multilayer film between the light-transmissive member and the first phosphor layer; a cover layer disposed on a lateral surface of the set of layers; and a light-emitting element disposed below the first phosphor layer. The light-emitting element emits blue light. The first phosphor layer absorbs at least a portion of the blue light and emits yellow-red to red light. The cover layer is either: a second phosphor layer that absorbs at least a portion of the blue light emitted by the light-emitting element and emits yellow-red to red light, or a pigment layer that presents yellow-red to red light.

First claim

What is claimed is:

1. A light-emitting device comprising:
a set of layers comprising (i) a light-transmissive member having a top surface, a bottom surface opposite the top surface, and a lateral surface contiguous with the top surface and the bottom surface, (ii) a first phosphor layer disposed below the bottom surface of the light-transmissive member, and (iii) a dielectric multilayer film between the light-transmissive member and the first phosphor layer;
a cover layer disposed on a lateral surface of the set of layers, the lateral surface of the set of layers comprising a lateral surface of the first phosphor layer, a lateral surface of the dielectric multilayer film, and the lateral surface of the light-transmissive member; and
a light-emitting element disposed below the first phosphor layer,
wherein:
the light-emitting element emits blue light,
the first phosphor layer absorbs at least a portion of the blue light emitted by the light-emitting element and emits yellow-red to red light, and

the cover layer is either:
a second phosphor layer that absorbs at least a portion of the blue light emitted by the light-emitting element and emits yellow-red to red light, or
a pigment layer that presents yellow-red to red light.

2. The light-emitting device of claim 1 ,
wherein the light-transmissive member has a flat-plate shape.

3. The light-emitting device of claim 1 ,
wherein the first phosphor layer and the light-emitting element are directly bonded to each other.

4. The light-emitting device of claim 1 ,
wherein the first phosphor layer and the light-emitting element are bonded together via a bonding member.

5. The light-emitting device of claim 4 ,
wherein the light-emitting element has a top surface, a bottom surface opposite the top surface of the light-emitting element, and a lateral surface contiguous with the top and bottom surfaces of the light-emitting element, and
wherein the top surface of the light-emitting element faces the first phosphor layer, and wherein the bonding member is disposed over the top surface and the lateral surface of the light-emitting element.

6. The light-emitting device of claim 5 ,
wherein the bonding member bonds the light-emitting element to the phosphor layer and to the cover layer.

7. The light-emitting device of claim 6 ,
wherein the light-emitting element has an area smaller than an area of the first phosphor layer in plan view.

8. The light-emitting device of claim 6 ,
wherein the bonding member has a portion located over the lateral surface of the light-emitting element and having a substantially triangular shape in a cross section.

9. The light-emitting device of claim 1 ,
wherein the size of the light-emitting element is the same as or smaller than the size of the first phosphor layer in plan view.

10. The light-emitting device of claim 1 ,
wherein the second phosphor layer contains a phosphor which absorbs the portion of the blue light emitted by the light-emitting element and emits the yellow-red to red light and whose density is less than a density of a phosphor of the first phosphor layer.

11. The light-emitting device of claim 1 ,
wherein the cover layer is spaced apart from the light-emitting element in a direction in which the first phosphor layer, the dielectric multilayer film, and the light-transmissive member are arranged.

12. The light-emitting device of claim 1 ,
wherein the cover layer is adjacent to the light-emitting element in a direction in which the first phosphor layer, the dielectric multilayer film, and the light-transmissive member are arranged.

13. A light-emitting device comprising:
a set of layers comprising (i) a light-transmissive member having a top surface, a bottom surface opposite the top surface, and a lateral surface contiguous with the top surface and the bottom surface, (ii) a first phosphor layer disposed above the top surface of the light-transmissive member, and (iii) a dielectric multilayer film between the light-transmissive member and the first phosphor layer;
a cover layer disposed on a lateral surface of the set of layers, the lateral surface of the set of layers comprising a lateral surface of the first phosphor layer, a lateral surface of the dielectric multilayer film, and the lateral surface of the light-transmissive member; and
a light-emitting element disposed below the light-transmissive member,
wherein:
the light-emitting element emits blue light,
the first phosphor layer absorbs at least a portion of the blue light emitted by the light-emitting element and emits yellow-red to red light, and
the cover layer is either:
a second phosphor layer that absorbs at least a portion of the blue light emitted by the light-emitting element and emits yellow-red to red light, or
a pigment layer that presents yellow-red to red light.

Assignees

• Nichia Corp

Inventors

• Yuasa Taiki
• Iwakura Daisuke

Classifications

• H10W72/30

  Die-attach connectors · CPC title

• H10W72/07351

  characterised by changes in properties of the die-attach connectors during connecting · CPC title

• H10H20/0361

  of wavelength conversion means · CPC title

• H10H20/851

  Wavelength conversion means · CPC title

• H10H20/84

  Coatings, e.g. passivation layers or antireflective coatings · CPC title