Light emitting device having multiple light emitting elements

Patent metadata

Field	Value
Publication number	US-2021050488-A1
Application number	US-202017086975-A
Country	US
Kind code	A1
Filing date	Nov 2, 2020
Priority date	Dec 22, 2017
Publication date	Feb 18, 2021
Grant date	—

Abstract

A light emitting device includes a first light emitting element including a rectangular first light extraction surface, a second light emitting element including a rectangular second light extraction surface and emitting light having an emission peak wavelength different from an emission peak wavelength of the first light emitting element, and a light-transmissive member covering the first light extraction surface and the second light extraction surface. The light-transmissive member includes a first light-transmissive layer facing the first light extraction surface and the second light extraction surface, a wavelength conversion layer located on the first light-transmissive layer, and a second light-transmissive layer located on the wavelength conversion layer. The first light-transmissive layer contains a first matrix and first diffusive particles. The wavelength conversion layer contains a second matrix and wavelength conversion particles. The second light-transmissive layer contains a third matrix and second diffusive particles.

First claim

What is claimed is:

1 . A light emitting device, comprising:
a first light emitting element including a rectangular first light extraction surface, a first electrodes formation surface located opposite to the first light extraction surface, a first lateral surface located between the first light extraction surface and the first electrodes formation surface, and a pair of first electrodes formed on the first electrodes formation surface; a second light emitting element including a rectangular second light extraction surface, a second electrodes formation surface located opposite to the second light extraction surface, a second lateral surface located between the second light extraction surface and the second electrodes formation surface, and a pair of second electrodes formed on the second electrodes formation surface, the second light emitting element emitting light having an emission peak wavelength different from an emission peak wavelength of the first light emitting element, a shorter side of the first light extraction surface and a shorter side of the second light extraction surface facing each other; a light guide member continuously covering the first light extraction surface, the first lateral surface, the second light extraction surface and the second lateral surface; a light-transmissive member covering the first light extraction surface and the second light extraction surface via the light guide member; and a first reflective member covering the first lateral surface and the second lateral surface via the light guide member; wherein: the light-transmissive member includes a wavelength conversion layer located above the light guide member, and a first light-transmissive layer located on the wavelength conversion layer; the first light-transmissive layer contains a first matrix and first diffusive particles; and the wavelength conversion layer contains a second matrix and wavelength conversion particles; and the first light extraction surface of the first light emitting element and the second light extraction surface of the second light emitting element have different heights from each other as seen in a cross-sectional view.

2 . The light emitting device of claim 1 , wherein the first light-transmissive layer and the light guide member are substantially free of a wavelength conversion particle.

3 . The light emitting device of claim 1 , wherein
the first light emitting element emits light having an emission peak wavelength of 430 nm or longer and shorter than 490 nm, and the second light emitting element emits light having an emission peak wavelength of 490 nm or longer and shorter than 570 nm; and the first light extraction surface of the first light emitting element is positioned lower than the second light extraction surface of the second light emitting element as seen in a cross-sectional view.

4 . The light emitting device of claim 1 , wherein
the first light emitting element emits light having an emission peak wavelength of 430 nm or longer and shorter than 490 nm, and the second light emitting element emits light having an emission peak wavelength of 490 nm or longer and shorter than 570 nm; and the first light extraction surface of the first light emitting element is positioned higher than the second light extraction surface of the second light emitting element as seen in a cross-sectional view.

5 . The light emitting device of claim 3 , wherein the wavelength conversion particles emit light having an emission peak wavelength of 580 nm or longer and shorter than 680 nm.

6 . The light emitting device of claim 4 , wherein the wavelength conversion particles emit light having an emission peak wavelength of 580 nm or longer and shorter than 680 nm.

7 . The light emitting device of claim 1 , wherein a shorter side of the first light extraction surface of the first light emitting element and a shorter side of the second light extraction surface of the second light emitting element have different lengths from each other.

8 . The light emitting device of claim 7 , wherein
the first light emitting element emits light having an emission peak wavelength of 430 nm or longer and shorter than 490 nm, and the second light emitting element emits light having an emission peak wavelength of 490 nm or longer and shorter than 570 nm; and the shorter side of the first light extraction surface is longer than the shorter side of the second light extraction surface.

9 . The light emitting device of claim 7 , wherein
the first light emitting element emits light having an emission peak wavelength of 430 nm or longer and shorter than 490 nm, and the second light emitting element emits light having an emission peak wavelength of 490 nm or longer and shorter than 570 nm; and the shorter side of the first light extraction surface is shorter than the shorter side of the second light extraction surface.

10 . The light emitting device of claim 1 , wherein the light-transmissive member further includes a second light-transmissive layer containing a third matrix and second diffusive particles, the second light-transmissive layer being located between the light guide member and the wavelength conversion layer.

11 . The light emitting device of claim 1 , wherein the wavelength conversion particles contain a manganese-activated fluoride phosphor.

12 . The light emitting device of claim 10 , wherein the wavelength conversion particles contain a manganese-activated fluoride phosphor.

13 . The light emitting device of claim 1 , further comprising a first cover member containing third diffusive particles, the first cover member covering the second light extraction surface.

14 . The light emitting device of claim 1 , further comprising a second reflective member covering the first electrodes formation surface and the second electrodes formation surface.

15 . The light emitting device of claim 1 , further comprising a third reflective member provided between the light guide member and the first reflective member.

16 . The light emitting device of claim 1 , further comprising a substrate on which the first light emitting element and the second light emitting element are placed.

17 . The light emitting device of claim 1 , further comprising a third light emitting element including a third light extraction surface, a third electrodes formation surface located opposite to the third light extraction surface, a third lateral surface located between the third light extraction surface and the third electrodes formation surface, and a pair of third electrodes formed on the third electrodes formation surface;
wherein: the light guide member continuously covers the third light extraction surface and the third lateral surface; the light-transmissive member covers the third light extraction surface via the light guide member; and the first reflective member covers the third lateral surface via the light guide member.

18 . The light emitting device of claim 17 , wherein the second light emitting element is located between the first light emitting element and the third light emitting element as seen in a front view.

19 . The light emitting device of claim 17 , wherein the third light emitting element emits light having an emission peak wavelength same as the emission peak wavelength of the first light emitting element.

20 . The light emitting device of claim 2 , wherein the first light emitting element emits light having an emission peak wavelength of 430 nm or longer and shorter than 490 nm, an

Assignees

• Nichia Corp

Inventors

• Nakabayashi Takuya
• Ikeda Tadaaki
• Hashimoto Toru
• Yokote Yukiko

Classifications

• H10W90/00 Primary

  Package configurations · CPC title

• H10H20/851

  Wavelength conversion means · CPC title

• H10H20/882

  Scattering means (H10H20/82 takes precedence) · CPC title

• H10H20/8585

  being an interconnection · CPC title

• H10H20/857

  Interconnections, e.g. lead-frames, bond wires or solder balls · CPC title