CN118867087A

CN118867087A - Light-emitting device

Info

Publication number: CN118867087A
Application number: CN202410506964.7A
Authority: CN
Inventors: 林达也; 大仓信也
Original assignee: Nichia Corp
Current assignee: Nichia Corp
Priority date: 2023-04-27
Filing date: 2024-04-25
Publication date: 2024-10-29

Abstract

The present invention provides a light-emitting device having a high brightness area and a low brightness area in a light-emitting surface. The device comprises: a light-emitting element having a light-emitting surface; a wavelength conversion layer having a lower surface and an upper surface located on the opposite side of the lower surface, and arranged on the light-emitting element in a manner that the lower surface is opposite to the light-emitting surface; the wavelength conversion layer comprises a first layer and a second layer, the first layer comprises first phosphor particles, the second layer comprises second phosphor particles and light-reflecting particles, and the upper surface and the lower surface of the wavelength conversion layer comprise the first layer and the second layer.

Description

Light emitting device

Technical Field

The present disclosure relates to light emitting devices.

Background

In recent years, LEDs have been used as light sources for vehicle lamps such as headlamps. For example, patent document 1 discloses a light emitting device having a light distribution suitable for a headlight by combining a plurality of light emitting elements having different light emitting areas.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2017-01259

Disclosure of Invention

Technical problem to be solved by the invention

The technical problem to be solved by the present disclosure is to provide a light emitting device having a high luminance region and a low luminance region in a light emitting surface.

Technical scheme for solving technical problems

The light emitting device of the embodiment of the present disclosure includes: a light emitting element having a light emitting surface; a wavelength conversion layer having a lower surface and an upper surface located on the opposite side from the lower surface, the lower surface being disposed on the light emitting element so as to face the light emitting surface; the wavelength conversion layer includes a first layer including first phosphor particles and a second layer including second phosphor particles and light reflection particles, and upper and lower surfaces of the wavelength conversion layer include the first layer and the second layer.

Advantageous effects

According to the embodiments of the present disclosure, a light emitting device having a high luminance region and a low luminance region in a light emitting surface can be provided.

Drawings

Fig. 1 is a perspective view schematically showing a light-emitting device according to embodiment 1.

Fig. 2 is a plan view schematically showing a light-emitting device according to embodiment 1.

Fig. 3A is a cross-sectional view taken along line A-A of fig. 2.

Fig. 3B is a cross-sectional view of a modification at line A-A of fig. 2.

Fig. 4A is a plan view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 4B is a cross-sectional view at line B-B of fig. 4A.

Fig. 5A is a plan view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 5B is a cross-sectional view at line C-C of fig. 5A.

Fig. 6A is a plan view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 6B is a cross-sectional view taken along line D-D of fig. 6A.

Fig. 7A is a plan view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 7B is a cross-sectional view taken along line E-E of fig. 7A.

Fig. 8 is a cross-sectional view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 9 is a cross-sectional view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 10 is a cross-sectional view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 11 is a cross-sectional view schematically showing an example of a process in the method for manufacturing the light-emitting device according to embodiment 1.

Fig. 12 is a perspective view schematically showing a light-emitting device according to embodiment 2.

Fig. 13 is a plan view schematically showing a light-emitting device according to embodiment 2.

Fig. 14 is a cross-sectional view taken along line F-F of fig. 13.

Fig. 15 is a plan view schematically showing the light emitting element 2 of the light emitting device of embodiment 2.

Fig. 16 is a plan view schematically showing a wiring board 50 of the light-emitting device according to embodiment 2.

Fig. 17 is a perspective view schematically showing a light-emitting device according to embodiment 3.

Fig. 18 is a cross-sectional view schematically showing a light-emitting device according to embodiment 3.

Description of the reference numerals

100. 200, 300: A light emitting device;

r: a light emitting region;

R1: a first light emitting region;

r2: a second light emitting region;

1. 2: a light emitting element;

1a: a light emitting surface of the light emitting element;

1e, 2e11, e221: an element electrode;

L1: a semiconductor structure;

L21: a first semiconductor structure;

l22: a second semiconductor structure;

s1, S2: a support substrate;

21: a first light emitting section;

22: a second light emitting section;

2e12p, 2e22p: a p electrode;

2e11n, 2e21n: an n-electrode;

10. 70: a wavelength conversion layer;

11. 71, M11: a first layer;

12. 72, M12: a second layer;

73: a third layer;

15. M15: a light-transmitting member;

17: an engagement member;

40: a wiring board;

41: a substrate;

42. 52: wiring;

421. 521: a first wiring;

422. 522: a second wiring;

523: a third wiring;

524: a fourth wiring;

525: a fifth wiring;

526: a sixth wiring;

30: an electronic component;

60: and a cladding member.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments described below are illustrative of a light emitting device and a method for manufacturing the light emitting device for realizing the technical idea of the present embodiment, and are not limited to the following. The dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention to these examples unless specifically described. The sizes, positional relationships, and the like of the components shown in the drawings may be exaggerated or simplified for clarity of description. In order to avoid the complexity of the drawings, some elements may be omitted from illustration, or an end view showing only a cross section may be used as a cross section. The term "cover" is not limited to the case of direct contact, but includes the case of indirect arrangement with other members interposed therebetween, for example. The term "disposed" is not limited to the case of direct contact, but includes the case of indirect disposition via other members, for example. In the present specification, the term "plan view" refers to a drawing from the light emitting surface side of the light emitting device.

The light emitting device of the embodiment of the present disclosure includes: a light emitting element having a light emitting surface; and a wavelength conversion layer having a lower surface and an upper surface located on the opposite side from the lower surface, the lower surface being disposed on the light emitting element so as to face the light emitting surface of the light emitting element.

Further, the wavelength conversion layer includes a first layer including first phosphor particles and a second layer including second phosphor particles and light reflection particles, and the upper and lower surfaces of the wavelength conversion layer include the first layer and the second layer.

In the light-emitting device configured as described above, the upper surface and the lower surface of the wavelength conversion layer include the first layer including the first phosphor particles and the second layer including the second phosphor particles and the light reflection particles, and thus light of different brightness can be emitted from the upper surface of the wavelength conversion layer.

That is, as described in detail later, light of different brightness can be emitted from the upper surface of the first layer and the upper surface of the second layer on the upper surface of the wavelength conversion layer based on the kind and content of the first phosphor particles contained in the first layer, the kind and content of the second phosphor particles and the light reflection particles contained in the second layer, and the like.

In this specification, unless otherwise specified, the upper surface refers to a surface on the emission side of the main light in the light-emitting device, and the lower surface refers to a surface on the opposite side from the upper surface.

In the light-emitting device according to the embodiment, light having a different emission spectrum may be emitted from the upper surface of the first layer and the upper surface of the second layer, based on the type and content of the first phosphor particles included in the first layer, the type and content of the second phosphor particles and the light-reflecting particles included in the second layer, and the like.

Hereinafter, embodiments will be described by way of specific configurations of the light emitting device of the present disclosure.

Embodiment 1

Fig. 1 is a perspective view of a light-emitting device according to embodiment 1. Fig. 2 is a top view of the light-emitting device according to embodiment 1 as viewed from above. Fig. 3A is a cross-sectional view taken along line A-A of fig. 2.

As shown in fig. 3A and the like, the light-emitting device of embodiment 1 includes a wiring board 40, a light-emitting element 1 disposed on the wiring board 40, and a wavelength conversion layer 10 disposed on the light-emitting element 1. The wavelength conversion layer 10 has a lower surface and an upper surface located on the opposite side from the lower surface, and is disposed on the light emitting element 1 so that the lower surface faces the light emitting surface 1a of the light emitting element. In the light-emitting device according to embodiment 1, the wavelength conversion layer 10 is bonded to the light-emitting surface 1a of the light-emitting element on the lower surface thereof by the light-transmissive bonding member 17. A light-transmitting member 15 is disposed on the upper surface of the wavelength conversion layer 10. In addition, the light emitting element 1, the wavelength conversion layer 10, and the side surfaces of the light transmissive member 15 are covered with the covering member 60 on the wiring board 40, except for the upper surface of the light transmissive member 15 (light emitting surface of the light emitting device 100).

In the light emitting device 100 of embodiment 1, the wavelength conversion layer 10 includes the first layer 11 and the second layer 12, the first layer 11 includes the first phosphor particles, the second layer 12 includes the second phosphor particles and the light reflection particles, and the upper surface and the lower surface of the wavelength conversion layer 10 include the first layer 11 and the second layer 12. That is, the lower surface of the wavelength conversion layer 10 includes the lower surface of the first layer 11 (hereinafter, there is a case called a first lower surface) and the lower surface of the second layer 12 (hereinafter, there is a case called a second lower surface), and the first lower surface and the second lower surface are disposed so as to face the light emitting surface 1a of the light emitting element 1, respectively, and the light of the light emitting element 1 is incident on the first layer 11 and the second layer 12 from the first lower surface and the second lower surface, respectively. The upper surface of the wavelength conversion layer 10 includes an upper surface of the first layer 11 (hereinafter, there is a case of being referred to as a first upper surface) and an upper surface of the second layer 12 (hereinafter, there is a case of being referred to as a second upper surface), and light having undergone wavelength conversion in the first layer 11 and the second layer 12 is emitted from the first upper surface and the second upper surface, respectively. Then, the light emitted from the first upper surface and the second upper surface is emitted from the first light-emitting region R1 and the second light-emitting region R2, which are part of the upper surface of the light-transmissive member 15 (i.e., the light-emitting region R of the light-emitting device 100), respectively.

Here, the light emitted from the first light-emitting region R1 and the second light-emitting region R2 can emit light having a luminance based on the type and content of the first phosphor particles contained in the first layer, the type and content of the second phosphor particles and the light-reflecting particles contained in the second layer, and the like, respectively. Thus, light of different brightness can be emitted from the first light-emitting region R1 and the second light-emitting region R2.

For example, a part of the light emitted from the light-emitting element 1 into the first layer 11 from the first lower surface is wavelength-converted into first converted light by the first phosphor particles included in the first layer, and the other part is emitted from the first upper surface without being converted. Thereby, the first converted light and the light of the light emitting element 1 are emitted from the first upper surface. A part of the light emitted from the light emitting element 1 in the second layer 12 from the lower surface of the second layer is wavelength-converted by the second phosphor particles included in the second layer to be second converted light, and the other part is not converted and emitted from the second upper surface. At this time, in the second layer 12, the second converted light and the light not converted by the second phosphor particles are scattered by the light reflecting particles contained in the second layer 12. Since the light quantity of the light emitted from the second upper surface can be reduced by scattering of the light generated in the second layer, the luminance of the second upper surface, that is, the luminance of the second light-emitting region R2 can be reduced. A part of the light scattered by the light-reflecting particles is incident on the first layer 11, for example, and is emitted from the first upper surface of the first layer 11. This can increase the amount of light emitted from the first upper surface, and can increase the luminance of the first light-emitting region R1. In this way, in the light-emitting device 100, the first light-emitting region R1 can be set to a high-luminance region, and the second light-emitting region R2 can be set to a low-luminance region that emits light having a lower luminance than the first light-emitting region R1.

When the light-emitting device 100 having the first light-emitting region R1 and the second light-emitting region R2 having a luminance difference on the light-emitting surface is used for a vehicle-mounted headlamp, a high-luminance region can be arranged in a desired region of the irradiation region. Therefore, a desired light distribution can be easily obtained without using a complicated optical design such as a mirror or a lens. Thus, the size of the headlamp can be reduced, and the design of the headlamp can be improved.

The first phosphor particles of the first layer 11 and the second phosphor particles of the second layer 12 preferably comprise the same phosphor material. This makes it possible to make the emission peak wavelengths of the first converted light and the second converted light identical, and to emit light having the same emission color from the first upper surface of the first layer 11 and the second upper surface of the second layer 12. Even when the first phosphor particles and the second phosphor particles contain the same phosphor material, light having different emission colors can be emitted from the first upper surface of the first layer 11 and the second upper surface of the second layer 12 by adjusting the content of each of the contained phosphor materials. The first phosphor particles of the first layer 11 and the second phosphor particles of the second layer 12 may contain different phosphor materials, and thus light having different emission colors can be easily emitted from the first upper surface of the first layer 11 and the second upper surface of the second layer 12.

In the wavelength conversion layer 10, the first layer 11 and the second layer 12 may be either in contact or separated. Among them, in the wavelength conversion layer 10, it is preferable that opposite sides of the first layer 11 and the second layer 12 are in contact with each other.

In the wavelength conversion layer 10, the first layer 11 is disposed in contact with the second layer 12, and thus, in the light-emitting region R of the light-emitting device 100, the first light-emitting region R1 and the second light-emitting region R2 having different luminance and/or chromaticity can be disposed adjacently.

At this time, the interface between the first layer 11 and the second layer 12 is made to be a surface substantially perpendicular to the upper surface of the wavelength conversion layer 10, so that the difference in luminance between the light emitted from the first upper surface and the light emitted from the second upper surface in the vicinity of the interface between the first layer 11 and the second layer 12 can be increased. In other words, the change in luminance in the vicinity of the boundary between the first layer 11 and the second layer 12 can be made abrupt.

In addition, as shown in fig. 3B, in the wavelength conversion layer 10, when the first layer 11 and the second layer 12 are in contact, the boundary between the first layer 11 and the second layer 12 is inclined with respect to the upper surface of the wavelength conversion layer 10, so that a rapid change in luminance in the vicinity of the boundary can be reduced.

That is, by appropriately adjusting the structure in the vicinity of the boundary between the first layer 11 and the second layer 12 according to the specification, the change in luminance in the vicinity of the boundary can be set. Here, the inclined boundary between the first layer 11 and the second layer 12 may be curved as shown in fig. 3B or may be a flat plane.

As described above, in the light-emitting device according to embodiment 1, the wavelength conversion layer 10 includes the first layer 11 and the second layer 12, and the first layer 11 includes the first phosphor particles and the second layer 12 includes the second phosphor particles and the light reflection particles, so that light having different brightness can be emitted from the first light-emitting region R1 and the second light-emitting region R2.

In the light-emitting device according to embodiment 1, the wavelength conversion layer 10 includes the first layer 11 and the second layer 12, and the first layer 11 includes the first phosphor particles and the second layer 12 includes the second phosphor particles and the light reflection particles, so that light of the same emission color or light of different emission colors can be emitted from the first emission region R1 and the second emission region R2.

Hereinafter, each structure of the light-emitting device of embodiment 1 will be described in detail.

[ Light-emitting element 1]

The light emitting element 1 has a light emitting surface 1a, a lower surface located on the opposite side of the light emitting surface 1a, and a side surface connected to the light emitting surface 1a and the lower surface. The light emitting element 1 can use a light emitting diode. The light-emitting element 1 includes a semiconductor structure L1 and at least one pair of positive and negative element electrodes 1e. In the present specification, the term "element electrode 1 e" is used without distinction between positive and negative in the description, and terms such as p-electrode and n-electrode are used in the case where distinction between positive and negative is required. The semiconductor structure L1 includes an n-side semiconductor layer, a p-side semiconductor layer, and an active layer sandwiched between the n-side semiconductor layer and the p-side semiconductor layer, and is disposed on the support substrate S1, for example. The active layer may be a Single Quantum Well (SQW) structure or a Multiple Quantum Well (MQW) structure including a plurality of well layers. The semiconductor structure includes, for example, a plurality of semiconductor layers made of nitride semiconductor. The nitride semiconductor includes semiconductors of all compositions In which the composition ratios x and y are varied within respective ranges In a chemical formula composed of In _xAl_yGa_1－x－y N (0.ltoreq.x, 0.ltoreq.y, x+y.ltoreq.1). The emission peak wavelength of the active layer can be appropriately selected according to the purpose. The active layer is configured to emit, for example, visible light or ultraviolet light.

In embodiment 1, the semiconductor structure has one light emitting portion including an n-side semiconductor layer, an active layer, and a p-side semiconductor layer, but may have a plurality of light emitting portions including an n-side semiconductor layer, an active layer, and a p-side semiconductor layer, respectively, as in the embodiments described later. The same emission peak wavelength includes a case where there is a variation of about several nm. The combination of the emission peak wavelengths of the plurality of light emitting units can be appropriately selected. For example, when the semiconductor structure includes two light emitting portions, a combination of blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or a combination of green light and red light can be given as a combination of light emitted from the respective light emitting portions. For example, when the semiconductor structure includes three light emitting portions, a combination of blue light, green light, and red light can be given as a combination of light emitted from the respective light emitting portions. Each light emitting portion may include one or more well layers having a different emission peak wavelength from other well layers. The shape, size, etc. of the light emitting element 1 can be variously selected according to the purpose.

The light emitting element 1 may include a support substrate S1 for supporting the semiconductor structure L1. The support substrate S1 includes an insulating substrate such as sapphire or spinel (MgAl ₂O₄), and a nitride semiconductor substrate such as InN, alN, gaN, inGaN, alGaN, inGaAlN. When light emitted from the light emitting portion is extracted through the support substrate (that is, when the support substrate forms the light emitting surface 1 a), a material having light transmittance is preferably used for the support substrate.

The light-emitting element 1 includes an element electrode disposed on at least a lower surface of the light-emitting element. The element electrodes are disposed on the same surface side of the semiconductor structure, for example, a pair of positive and negative element electrodes. The positive and negative element electrodes can be arranged in consideration of the wiring positions of the wiring board 40. The element electrode of the light-emitting element 1 is connected to the wiring of the wiring board 40 via, for example, a conductive bonding member. As the conductive bonding member, a eutectic solder, a conductive paste such as a metal, a bump, or the like can be used. The element electrode of the light-emitting element 1 and the wiring may be directly connected by bonding without via a conductive member.

[ Wavelength conversion layer 10]

As described above, the wavelength conversion layer 10 includes the first layer 11 and the second layer 12, the first layer 11 includes the first phosphor particles, and the second layer 12 includes the second phosphor particles and the light reflection particles. The wavelength conversion layer 10 has an upper surface and a lower surface, the upper surface of the wavelength conversion layer comprising the upper surface of the first layer 11 and the upper surface of the second layer 12, and the lower surface of the wavelength conversion layer 10 comprising the lower surface of the first layer 11 and the lower surface of the second layer 12. In other words, the wavelength conversion layer 10 includes: a first layer 11 containing first phosphor particles; and a second layer 12 disposed adjacent to the first layer and including second phosphor particles and light reflecting particles. The first phosphor particles and the second phosphor particles convert at least a part of the wavelength of light from the light emitting element 1 into different wavelengths in the first layer 11 and the second layer 12.

As the wavelength conversion layer 10, for example, a layer in which a light-transmitting material such as a resin, glass, or an inorganic substance is used as a binder, a phosphor as first phosphor particles and the light-transmitting material are mixed in the first layer 11, and a phosphor as second phosphor particles, a light-reflecting member as light-reflecting particles, and the light-transmitting material are mixed in the second layer is used. As the light-transmitting material, for example, an organic resin material such as an epoxy resin, a silicone resin, a phenol resin, or a polyimide resin, or an inorganic material such as glass or ceramic is used.

In the wavelength conversion layer 10, the first phosphor particles in the first layer may be dispersed or partially biased. For example, in the first layer, the first phosphor particles may be disposed so as to be offset to the lower surface side (i.e., the light emitting element side in the light emitting device 100). Similarly, the second phosphor particles and the light reflecting particles in the second layer may be disposed in a dispersed manner or may be disposed in an offset manner. For example, in the second layer, the second phosphor particles may be disposed so as to be offset to the lower surface side (i.e., the light emitting element side in the light emitting device 100), and the light reflecting particles may be disposed so as to be offset to the upper surface side (i.e., the light emitting surface side in the light emitting device 100).

As the phosphor, yttrium aluminum garnet-based phosphor (for example, (Y, gd) ₃(Al,Ga)₅O₁₂: ce), lutetium aluminum garnet-based phosphor (for example, lu ₃(Al,Ga)₅O₁₂: ce), terbium aluminum garnet-based phosphor (for example, tb ₃(Al,Ga)₅O₁₂: ce), and the like can be used, CCA-based phosphors (e.g., ca ₁₀(PO₄)₆Cl₂: eu), SAE-based phosphors (e.g., sr ₄Al₁₄O₂₅: eu), chlorosilicate-based phosphors (e.g., ca ₈MgSi₄O₁₆Cl₂: eu), silicate-based phosphors (e.g., (Ba, nitrogen oxide-based phosphors such as Sr, ca, mg) ₂SiO₄ Eu, beta-sialon-based phosphors (e.g., (Si, al) ₃(O,N)₄: eu), or alpha-sialon-based phosphors (e.g., ca (Si, al) ₁₂(O,N)₁₆: eu), LSN-based phosphors (e.g., (La, Y) ₃Si₆N₁₁: ce), BSESN-based phosphors (e.g., (Ba, sr) ₂Si₅N₈: eu), SLA-based phosphors (e.g., srLiAl ₃N₄: eu), CASN-based phosphors (e.g., (CaAlSiN ₃: eu)) or SCASN-based phosphors (e.g., (Sr, ca) AlSiN ₃: eu), KSF (for example, K ₂SiF₆: mn), KSAF (for example, K ₂(Si_1－xAl_x)F_6－x: mn, where x satisfies 0< x < 1). ) Or a fluoride-based fluorescent material such as an MGF-based fluorescent material (e.g., 3.5MgO.0.5 MgF ₂·GeO₂: mn), a quantum dot having a perovskite structure (e.g., cs, FA, MA) (Pb, sn) (F, cl, br, I) ₃, wherein FA and MA represent formamidinium and methylammonium, respectively), a group II-VI quantum dot (e.g., CdSe), group III-V quantum dots (e.g., inP), or quantum dots having a jamesonite structure (e.g., (Ag, cu) (In, ga) (S, se) ₂), and the like.

Examples of the light-reflective material include titanium oxide, silicon oxide, zirconium oxide, aluminum oxide, magnesium oxide, calcium carbonate, calcium hydroxide, calcium silicate, zinc oxide, barium titanate, potassium titanate, aluminum nitride, boron nitride, mullite, and combinations thereof. Among them, titanium oxide is preferable because it is relatively stable against moisture and has a high refractive index.

The first phosphor particles and the second phosphor particles can be appropriately selected according to the specifications of the light emitting device 100 required for the phosphor described above.

For example, as a phosphor capable of emitting yellow light of white mixed light in combination with a blue light emitting element, an yttrium aluminum garnet phosphor (for example, (Y, gd) ₃Al₅O₁₂:ce) in which a part of Y is substituted with Gd can be preferably used. In the case of the light-emitting device 100 capable of emitting white light, the type and concentration of the first phosphor particles included in the first layer 11 are adjusted so as to emit white light of a desired color temperature from the first layer 11 at a desired intensity, and the type and concentration of the second phosphor particles included in the second layer 12 and the type and concentration of the light-reflecting particles are adjusted so as to emit white light of a desired color temperature from the second layer 12 at a desired intensity.

The wavelength conversion layer 10 is configured by disposing a light-transmitting member 15 such as a glass plate, which will be described later, on the surface of the light-transmitting member 15. The wavelength conversion layer 10 can be disposed on the light-transmitting member 15 by potting, printing, spraying, or the like. When the wavelength conversion layer 10 includes a resin, the wavelength conversion layer 10 (i.e., the first layer 11 and the second layer 12) is supported by the light-transmitting member 15, and therefore, the first layer 11 and the second layer 12 can be easily disposed adjacent to each other with a predetermined film thickness. The thicknesses (i.e., the shortest length from the upper surface to the lower surface) of the first layer 11 and the second layer 12 in the wavelength conversion layer 10 are preferably the same thickness. Thus, since the thickness of one wavelength conversion layer 10 is substantially constant, it is easy to dispose the wavelength conversion layer 10 on the light emitting element 1 in the manufacturing process. The thickness of the wavelength conversion layer 10 is set in consideration of the relationship between the type and concentration of the first phosphor particles, the type and concentration of the second phosphor particles, and the type and concentration of the light reflection particles, so that light of a desired chromaticity is emitted from each of the first layer 11 and the second layer 12 at a predetermined intensity. For example, in view of downsizing of the light emitting device 100, mechanical strength of the wavelength conversion layer 10, and the like, the thickness of the wavelength conversion layer 10 is set to 20 μm or more and 300 μm or less, preferably 50 μm or more and 150 μm or less.

[ Light-transmitting Member 15]

The light-transmitting member 15 is formed by molding a light-transmitting material such as resin, glass, or inorganic material into a plate shape. The light-transmitting member 15 is disposed so that the lower surface thereof is in contact with the upper surface of the wavelength conversion layer 10 in a size equivalent to that of the wavelength conversion layer 10 in plan view. Here, the same size means that the difference between the area of the lower surface of the light-transmitting member 15 and the area of the upper surface of the wavelength conversion layer 10 is within ±5% of one or the other. As the glass, borosilicate glass, quartz glass, or the like can be used, and as the resin, silicone resin, epoxy resin, or the like can be used, for example. Among them, glass is preferably used for the light-transmitting member 15 in view of being less likely to be degraded by light, mechanical strength, and the like. The light-transmitting member 15 may contain a light-diffusing member. By including the light-transmitting member 15 with a light-diffusing member, chromaticity unevenness and luminance unevenness can be suppressed. As the light diffusion member, for example, titanium oxide, barium titanate, aluminum oxide, silicon oxide, or the like can be used.

The light-transmitting member 15 may be disposed on the wavelength conversion layer 10 via another member such as a light-transmitting adhesive layer. The light-transmitting member 15 may be disposed on the wavelength conversion layer 10 with an optical layer such as a dielectric multilayer film interposed therebetween. The dielectric multilayer film is, for example, a DBR (Distributed BraggReflector: distributed bragg reflection film).

[ Wiring Board 40]

The wiring board 40 is a plate-like member including a base material 41 and wiring 42 disposed on an upper surface of the base material 41.

The base material 41 is made of, for example, an insulating material such as glass epoxy resin, or ceramic, a semiconductor material such as silicon, or a conductive material such as metal. Among them, ceramics having high heat resistance and light resistance can be preferably used. Examples of the ceramics include alumina, aluminum nitride, silicon nitride, and LTCC. In addition, composite materials of these insulating materials, semiconductor materials, and conductive materials can also be used. When a conductive material such as a semiconductor material or a metal is used as the base 41, the wiring 42 can be arranged on the upper surface and the lower surface of the base 41 via an insulating layer.

The wiring 42 includes at least a first wiring 421 and a second wiring 422 disposed on the upper surface of the substrate 41. The wiring 42 may further include an external connection terminal disposed on a lower surface opposite to the upper surface. In this case, the first wiring 421 and the second wiring 422 disposed on the upper surface of the base material 41 may be connected to external connection terminals via, for example, relay wirings disposed inside and on the side surfaces of the base material 41. Examples of the material of the wiring 42 include metals such as Fe, cu, ni, al, ag, au, pt, ti, W, pd and alloys containing at least one of these metals.

[ Electronic component 30]

The electronic component 30 is, for example, a protection element. The protection element is, for example, a zener diode. The electronic component 30 is connected to the first wiring 421 and the second wiring 422 through conductive members, for example. The light-emitting device 100 may not include the electronic component 30.

[ Coating Member 60]

The cover member 60 exposes the upper surface of the light-transmitting member 15 on the wiring board 40, and covers the side surface of the light-transmitting member 15, the side surface of the wavelength conversion layer 10, and the side surface of the light-emitting element 1. When the light-emitting device 100 includes the electronic component 30, the cover member 60 preferably covers the electronic component 30.

The cover member 60 preferably has light shielding properties (specifically, light reflecting properties and/or light absorbing properties), and among these, light reflecting properties are preferable. Further, the cover member 60 is preferably made of an insulating material. As the covering member 60, for example, a thermosetting resin, a thermoplastic resin, or the like can be used. Specifically, the coating member 60 may be a resin containing particles of a light-reflective material. The resin may be one or more resins selected from the group consisting of silicone resins, modified silicone resins, epoxy resins, modified epoxy resins, acrylic resins, phenolic resins, bismaleimide triazine resins, and polyphthalamide resins, or a mixture of resins. Among them, a resin containing a silicone resin having excellent heat resistance, electrical insulation and flexibility as a base polymer is preferable. As the light-reflective substance, a material selected from materials exemplified as the material of the wavelength conversion layer 10 can be used. The coating member 60 may further contain particles of a light absorbing substance such as pigment, carbon black, titanium black, or graphite. In the coating member 60 having light reflectivity and/or light absorptivity, particles of the light reflectivity substance and/or light absorptivity substance are preferably dispersed in the resin.

The concentration of the light-reflective material of the covering member 60 is preferably 60% by mass or more and 70% by mass or less, for example. The concentration of the light-reflective material indicates the proportion of the light-reflective material in the cover member 60 containing the light-reflective material. The reflectance of the cover 60 is, for example, preferably 70% or more, and more preferably 80% or more. The reflectance is a reflectance at the emission peak wavelength of the light emitted from the light emitting element 1.

Hereinafter, a method for manufacturing the light-emitting device according to embodiment 1 will be described.

The method for manufacturing a light-emitting device according to embodiment 1 includes:

(1) A step ST1 of preparing the light emitting element 1;

(2) A step ST2 of preparing a collective substrate;

(3) A step ST3 of preparing the wavelength conversion layer 10;

(4) A step ST4 of disposing the light emitting element 1;

(5) A step ST5 of disposing the wavelength conversion layer 10;

(6) A step ST6 of disposing the covering member;

(7) And step ST7 of singulating the light emitting devices.

The step ST3 of preparing the wavelength conversion layer 10 includes:

A step ST31 of preparing a first resin and a second resin;

A step ST32 of disposing a first layer on the light-transmitting member;

ST33 of disposing the second layer on the light-transmitting member;

Step ST34 of singulating each wavelength conversion layer 10.

Hereinafter, each step will be described.

(1) Step ST1 of preparing light-emitting element 1

In step ST1 of preparing the light-emitting element 1, the light-emitting element 1 is prepared, and the light-emitting element 1 includes a support substrate, a semiconductor structure including at least one light-emitting portion, and at least one pair of positive and negative element electrodes. Specifically, in the light emitting element 1, the semiconductor structure is disposed on the support substrate, and at least one pair of positive and negative element electrodes is disposed on a surface of the semiconductor structure opposite to the support substrate. Here, the light emitting surface of the light emitting element is a surface on the support substrate side, and a wavelength conversion layer described later is disposed on the support substrate. The light emitting element 1 can be prepared through part or all of the manufacturing process such as the semiconductor growth process. Alternatively, the light emitting element 1 may be prepared by purchase, transfer, or the like.

(2) Step ST2 of preparing a collective substrate

In step ST2 of preparing the aggregate substrate, the aggregate substrate including a plurality of substrate regions serving as wiring substrates of the light emitting device 100 is prepared. The plurality of substrate regions are arranged in a matrix, for example. For the preparation of the aggregate substrate, first, a plate-like base material (i.e., an aggregate of the base materials 41) such as glass epoxy, resin, ceramic, or the like is prepared. Then, first and second wirings are formed in each substrate region of the base material. The first wiring and the second wiring can be formed by a known method such as plating, vapor deposition, or sputtering. The aggregate substrate may be prepared by preparing a substrate on which wiring is arranged in advance, for example, by purchasing or transferring the substrate.

(3) Step ST3 of preparing wavelength conversion layer 10

In step ST3 of preparing the wavelength conversion layer 10, a wavelength conversion layer in which a first layer using a first resin and a second layer using a second resin are arranged is prepared. Here, as the wavelength conversion layer 10, the wavelength conversion layer 10 disposed on the light-transmitting member is prepared.

For example, the step ST3 of preparing the wavelength conversion layer 10 includes: a step ST31 of preparing a first resin and a second resin; a step ST32 of disposing a first layer on the light-transmitting member; ST33 of disposing the second layer on the light-transmitting member; step ST34 of singulating the wavelength conversion layers.

In step ST31 of preparing the first resin and the second resin, the first resin containing the first phosphor particles and the second resin containing the second phosphor particles and the light reflecting particles are prepared.

In step ST32 of disposing the first layer on the light-transmissive member, as shown in fig. 4A and 4B, the first layer M11 is formed in a stripe shape on the flat plate-like light-transmissive member M15, for example. Here, the light-transmitting member M15 is an aggregate including a plurality of regions that become the light-transmitting members 15 of the respective light-emitting devices 100 after singulation. The first layer M11 includes a plurality of first layers 11 that constitute wavelength conversion layers of the respective light emitting devices 100 after singulation. The same applies to the second layer M12. Here, the first layer M11 is shown as being formed in a stripe shape, but the first layer M is not limited to the stripe shape, and may be formed in a lattice shape or the like, or may be formed in an island shape. The first layer can be formed on the light-transmitting member M15 by, for example, printing using a mask.

In step ST33 of disposing the second layer on the light-transmitting member, the second layer M12 is formed in a stripe shape between the first layers M11 by printing using a mask, for example, in the same manner as in step S32 of forming the first layer described above. The present step is not limited to printing, and for example, as shown in fig. 5A and 5B, after the frame F12 surrounding the first layer M11 is formed on the light-transmitting member M15, the second layer M12 may be formed between the first layers M11 by potting or the like as shown in fig. 6A and 6B. The second layer M12 may be formed in an island shape.

Next, in step ST34 of singulating each wavelength conversion layer 10, as shown in fig. 7A and 7B, the first layer M11, the second layer M12, and the light-transmitting member 15 are divided so that the singulated wavelength conversion layer 10 includes the first layer 11 and the second layer 12 (for example, along a separation line indicated by a broken line DL1 in fig. 7B), thereby obtaining the wavelength conversion layer 10 disposed on the light-transmitting member 15.

Through the above steps, the wavelength conversion layer 10 including the first layer 11 and the second layer 12, which is disposed on the light-transmitting member 15, is prepared.

(4) Step ST4 of disposing light-emitting element 1

In step ST4 of disposing the light emitting elements 1, the light emitting elements 1 are disposed in the substrate regions of the aggregate substrate. As shown in fig. 8, for example, the light-emitting element 1 is arranged at a predetermined position in the substrate region such that the element electrodes 1e face the wirings 42. The wiring 42 and the element electrode 1e are bonded by, for example, a conductive bonding member. The electronic component 30 is also disposed at a predetermined position as needed.

The member denoted by reference numeral M40 in fig. 8 and the like is a mask provided to expose the wiring 42 from the covering member 60.

(5) Step ST5 of disposing wavelength conversion layer 10

In step ST5 of disposing the wavelength conversion layer 10, as shown in fig. 9, the wavelength conversion layer 10 is disposed so as to face the light emission surface of the light emitting element 1 disposed on the aggregate substrate. The light emitting element 1 and the wavelength conversion layer 10 are bonded by, for example, a bonding member having light transmittance. Although the wavelength conversion layer 10 is disposed together with the light-transmitting member 15 in the above example, the wavelength conversion layer 10 may be disposed on the light-emitting element 1 alone. In addition, the light-transmitting member 15 may be removed after the wavelength conversion layer 10 is disposed together with the light-transmitting member 15. In the following description, an example of a light-emitting device including the light-transmitting member 15 will be described.

(6) Step ST6 of disposing the coating Member

In step ST6 of disposing the cover member, as shown in fig. 10, the cover member 60 is disposed so as to cover the side surfaces of the light emitting element 1, the wavelength conversion layer 10, and the light transmissive member 15 disposed on the aggregate substrate and expose the upper surface of the light transmissive member 15, which is the light emitting surface of the light emitting device. The cover member 60 is disposed by, for example, coating an uncured resin including a light-reflective material so as to cover the side surfaces of the light-emitting element 1, the wavelength conversion layer 10, and the light-transmissive member 15, and then curing the resin. The upper surface of the light-transmissive member 15 can be exposed from the covering member by, for example, applying an uncured resin to a region other than the upper surface of the light-transmissive member 15.

After the placement of the sheathing member 60 (after curing), the mask M40 is removed as shown in fig. 11. The mask M40 may be removed after singulation, which will be described later.

In the step of disposing the sheathing member, the wall for holding the sheathing member may be disposed on the collective substrate without using the mask M40. For example, a resin having a higher hardness than the resin forming the coating member can be used as the wall. The wall may be a part of the base material, and the wiring board may have a structure having a concave portion in which the light emitting element is disposed, for example.

(7) Step of singulating each light emitting device

In the step of singulating the individual light emitting devices, the collective substrate is separated for each light emitting device 100 by a blade or the like along the outer edge of each substrate region (for example, a separation line indicated by a broken line DL2 in fig. 11).

Through the above steps, the light-emitting device 100 of embodiment 1 was manufactured.

In the method for manufacturing the light-emitting device 100 according to embodiment 1, various parameters such as chromaticity and emission spectrum of light emitted from the upper surface of the first layer 11, chromaticity and emission spectrum of light emitted from the upper surface of the second layer 12, luminance in the first light-emitting region R1, and luminance in the second light-emitting region R2 are set by selecting appropriate materials for the type of the light-emitting element 1, the material of the wavelength conversion layer, and the like, and further, by appropriately setting the film thickness of the wavelength conversion layer.

Hereinafter, a material selection and a setting example of relevant parameters in the method of manufacturing the light-emitting device 100 according to embodiment 1 will be described.

In the method for manufacturing the light-emitting device 100 according to embodiment 1, the materials of the light-emitting element 1, the first phosphor particles, and the second phosphor particles are selected so that light having a predetermined emission spectrum is emitted from the first emission region R1 and the second emission region R2 of the light-emitting device 100, respectively.

For example, when light having the same emission spectrum is emitted from the first and second light-emitting regions R1 and R2, for example, the first and second phosphor particles are preferably selected from the same material. Even when the first phosphor particles and the second phosphor particles are made of the same material, the emission spectrum of the emitted light is affected by the content of the phosphor particles contained in the first layer 11 and the second layer 12, but the content of the phosphor particles contained in the first layer 11 and the second layer 12 can be set more easily than when different materials are selected as the first phosphor particles and the second phosphor particles. As understood from the above description, even when the same material is selected as the first phosphor particles and the second phosphor particles, the emission spectrum of the light emitted from the first light emitting region R1 can be made different from the emission spectrum of the light emitted from the second light emitting region R2 by appropriately adjusting the content or the like of the phosphor particles included in the first layer 11 and the second layer 12.

In the method for manufacturing the light-emitting device 100 according to embodiment 1, when the luminance of the upper surface of the first layer 11 and the luminance of the upper surface of the second layer 12 are set to predetermined luminances, for example, the content of the first phosphor particles in the first resin, the content of the second phosphor particles and the light-reflecting particles in the second resin, the thickness of the first layer 11, the thickness of the second layer 12, and the like are set to predetermined luminances, respectively.

For example, when the first phosphor particles and the second phosphor particles are made of the same phosphor material, light can be emitted from the first light-emitting region R1 and the second light-emitting region R2 at different luminances by appropriately adjusting the content of the first phosphor particles included in the first layer, the types and the content of the second phosphor particles and the light-reflecting particles included in the second layer, and the like. For example, if the content of the light reflective particles included in the second layer 12 is increased, the light after wavelength conversion in the second layer 12 and the light incident into the second layer 12 from the light emitting element are scattered more, and therefore the light quantity of the light emitted from the second upper surface can be reduced. In addition, light scattered by the second layer 12 enters the first layer 11, and thus the amount of light emitted from the first upper surface of the first layer 11 increases, and the amount of light emitted from the first upper surface can be increased.

The arrangement of the first phosphor particles in the first layer 11, the second phosphor particles in the second layer 12, and the light reflection particles may be adjusted. For example, by disposing the light reflective particles on the upper surface side of the second layer 12, the ratio of light wavelength-converted in the second layer 12 to light incident on the first layer 11 from the light emitting element into the second layer 12 can be adjusted, and the luminance difference between the first light emitting region R1 and the second light emitting region R2 can be adjusted. The adjustment of the arrangement position of each particle in each layer can be set by appropriately adjusting the type and particle diameter of each particle.

As described above, according to the method of manufacturing the light-emitting device 100 of embodiment 1, by appropriately selecting the type of the light-emitting element 1 and the phosphor material and appropriately setting parameters related to the content of phosphor particles and the like of the first layer 11 and the second layer 12, the film thickness and the like, it is possible to manufacture a light-emitting device capable of emitting light of a predetermined emission color from each of the first light-emitting region R1 and the second light-emitting region R2 at a predetermined luminance. In the method for manufacturing the light-emitting device 100 according to embodiment 1, parameters in each step may be set using a database storing the relationship between the types of the light-emitting elements 1, the types of the phosphor materials, the content of phosphor particles in the first layer 11 and the second layer 12, the film thickness, and the like, and the emission color and the luminance of the light emitted from the first light-emitting region R1 and the second light-emitting region R2, respectively.

Embodiment 2

The light emitting device 200 according to embodiment 2 of the present disclosure is different from the light emitting device 100 according to embodiment 1 in that the light emitting element 2 includes a first light emitting portion 21 and a second light emitting portion 22, and light emitted from the first light emitting portion 21 is incident on the first layer 11 of the wavelength conversion layer 10 and light emitted from the second light emitting portion 22 is incident on the second layer 12 of the wavelength conversion layer 10. The light emitting element 2 includes the first light emitting portion 21 and the second light emitting portion 22, and thus the wiring structure of the wiring board is also different.

Hereinafter, the light emitting device 200 of embodiment 2 will be described mainly with respect to points different from the light emitting device 100 of embodiment 1.

Here, fig. 12 is a perspective view of a light-emitting device 200 according to embodiment 2. Fig. 13 is a top view of the light-emitting device according to embodiment 2. Fig. 14 is a cross-sectional view taken along line F-F of fig. 13. Fig. 15 is a plan view showing the electrode arrangement of the light emitting element 2, and fig. 16 is a plan view showing the wiring of the wiring board 50.

In the light-emitting device 200 according to embodiment 2, the light-emitting element 2 includes the first light-emitting portion 21 and the second light-emitting portion 22 on the support substrate S2. The first light emitting unit 21 includes a first semiconductor structure L21 disposed on the support substrate S2 and an element electrode 2e11 provided on the first semiconductor structure L21. The second light emitting section 22 includes a second semiconductor structure L22 provided on the support substrate S2 and an element electrode 2e21 provided on the second semiconductor structure L22. Here, the first semiconductor structure L21 and the second semiconductor structure L22 are provided separately on the support substrate S2, for example.

Here, for example, the first light emitting portion and the second light emitting portion, in other words, the first semiconductor structure L21 and the second semiconductor structure L22 may have the same semiconductor structure or may have different semiconductor structures. By providing the element electrodes separately in the first semiconductor structure L21 and the second semiconductor structure L22, the individual lighting can be achieved. The first light-emitting portion and the second light-emitting portion may be connected in series to each other by the element electrodes, and may be lighted together. Even when the first semiconductor structure L21 and the second semiconductor structure L22 emit light having the same emission color, light having different emission colors can be emitted from the first emission region R1 and the second emission region R2 by adjusting the content of the phosphor material, the first phosphor particles, the second phosphor particles, the light reflecting material particles, and the like in the first layer 11 and the second layer 12 in the wavelength conversion layer 10.

In the light-emitting device 200 according to embodiment 2, as shown in fig. 15, for example, the electrodes of the light-emitting element 2 may be provided with p electrodes 2e12p and 2e22p in the central portions of the first semiconductor structure L21 and the second semiconductor structure L22, and n electrodes 2e11n and 2e21n may be provided on both sides of the p electrodes 2e12p and 2e22p, respectively. Here, although fig. 15 shows an example in which the first semiconductor structure L21 and the second semiconductor structure L22 are separated, the first semiconductor structure L21 and the second semiconductor structure L22 may have a structure in which the active layers are separated and the p-side semiconductor layer or the n-side semiconductor layer is connected.

In the light emitting device 200 according to embodiment 2, the wiring 52 in the wiring board 50 includes, for example, as shown in fig. 16, a first wiring 521, a second wiring 522, and a third wiring 523 connected to the first light emitting section 21, and a fourth wiring 524, a fifth wiring 525, and a sixth wiring 526 connected to the second light emitting section 22.

The third wiring 523 is disposed at a position facing the p-electrode 2e12p in the region where the first light emitting portion 21 is mounted. The first wiring 521 is provided so as to include an internal connection portion disposed at a position facing the n-electrode 2e11n of the first light emitting portion 21, that is, on both sides of the third wiring 523, and a first external connection portion extending from the mounting portion to an end portion. The second wiring 522 is provided in the first external connection portion in parallel to one end of the wiring board. Here, the second wiring 522 and the third wiring 523 are connected to each other so as not to be electrically connected to the first wiring 521 by a conductive member such as a wire or a relay wiring provided on a substrate.

The fourth wiring 524, the fifth wiring 525, and the sixth wiring 526 are also provided in the region where the second light emitting portion 22 is mounted, similarly to the first wiring 521, the second wiring 522, and the third wiring 523, respectively.

While the first wiring 521 and the fourth wiring 524, and the third wiring 523 and the sixth wiring 526 are each electrically separated from each other and disposed on the substrate, the first wiring 521 and the fourth wiring 524, or the third wiring 523 and the sixth wiring 526 may be electrically connected to each other.

The light emitting element 2 is mounted on the wiring board 50 configured as described above, so that the p-electrode 2e12p of the first semiconductor structure L21 is connected to the third wiring 523, the n-electrode 2e11n is connected to the first wiring 521, the p-electrode 2e22p of the second semiconductor structure L22 is connected to the sixth wiring 526, and the n-electrode 2e21n is connected to the fourth wiring 524.

In the light-emitting device 200 according to embodiment 2, the wavelength conversion layer is configured in the same manner as the light-emitting device 100 according to embodiment 1, the first layer 11 is positioned above the first light-emitting portion 21 via the support substrate S2, and the second layer 12 is positioned above the second light-emitting portion 22 via the support substrate S2.

In the light-emitting device 200 of embodiment 2 configured as described above, the wavelength conversion layer 10 includes the first layer 11 and the second layer 12, and the first layer 11 includes the first phosphor particles and the second layer 12 includes the second phosphor particles and the light reflection particles, so that light of different brightness can be emitted from the first light-emitting region R1 and the second light-emitting region R2.

In the light-emitting device 200 according to embodiment 2, the wavelength conversion layer 10 includes the first layer 11 and the second layer 12, and the first layer 11 includes the first phosphor particles and the second layer 12 includes the second phosphor particles and the light reflection particles, and therefore, light having the same emission color or light having a different emission color can be emitted from the first emission region R1 and the second emission region R2 in the same manner as the light-emitting device 100 according to embodiment 1.

In particular, the light-emitting device 200 according to embodiment 2 can select the emission color and the emission intensity of the first light-emitting portion 21 and the second light-emitting portion 22 as desired, and thus can easily increase the difference in luminance and the difference in emission color between the first light-emitting region R1 and the second light-emitting region R2.

Further, since the first light emitting portion 21 and the second light emitting portion 22 can be independently turned on, the luminance of the first light emitting region R1 or the second light emitting region R2 can be made substantially zero.

Further, since the light emission color and the light emission intensity of the first light emitting portion 21 and the light emission color and the light emission intensity of the second light emitting portion 22 can be variously selected, the light emitting device having the first region R1 and the second region R2 of the desired light emission color and light emission intensity can be obtained.

Embodiment 3

The light emitting device 300 according to embodiment 3 of the present disclosure is different from the light emitting device 100 according to embodiment 1 in that the wavelength conversion layer 70 includes a third layer 73 between the first layer 71 and the second layer 72 in addition to the first layer 71 and the second layer 72.

Here, the third layer 73 contains third phosphor particles and light reflecting particles, and the concentration of the light reflecting particles in the third layer 73 is smaller than that in the second layer 72.

The third phosphor particles included in the third layer 73 may be the same as or different from either the first phosphor particles or the second phosphor particles.

The light reflecting particles contained in the third layer 73 may be the same as or different from the light reflecting particles contained in the second layer 72.

Thus, the light emitting device 300 can be formed as the light emitting device 300 having the third light emitting region R3 (middle luminance region) between the first light emitting region R1 (high luminance region) and the second light emitting region R2 (low luminance region). In the light emitting device 300, the luminance of the middle luminance region is greater than the luminance of the low luminance region, and the luminance of the high luminance region is smaller.

Since the light emitting device 300 includes the middle luminance region, the luminance difference between the high luminance region and the low luminance region can be relaxed.

The light-emitting device according to the embodiment of the present disclosure includes, for example, the following embodiments.

Scheme 1

A light-emitting device, comprising:

a light emitting element having a light emitting surface;

A wavelength conversion layer having a lower surface and an upper surface located on the opposite side from the lower surface, the lower surface being disposed on the light emitting element so as to face the light emitting surface;

the wavelength conversion layer comprises a first layer comprising first phosphor particles and a second layer comprising second phosphor particles and light reflecting particles,

The upper and lower surfaces of the wavelength conversion layer include the first layer and the second layer.

Scheme 2

The light-emitting device according to claim 1, comprising a light-transmitting member disposed on the wavelength conversion layer.

Scheme 3

The light-emitting device according to any one of aspects 1 to 2, wherein the first phosphor particles of the first layer and the second phosphor particles of the second layer contain the same phosphor material.

Scheme 4

The light-emitting device according to any one of claims 1 to 3, wherein the first layer is in contact with the second layer at the wavelength conversion layer.

Scheme 5

The light-emitting device according to claim 4, wherein a boundary between the first layer and the second layer is inclined with respect to an upper surface of the wavelength conversion layer.

Scheme 6

The light-emitting device according to any one of claims 1 to 5, further comprising a cladding member that covers a side surface of the light-emitting element and a side surface of the wavelength conversion layer.

Scheme 7

The light-emitting device according to any one of claims 1 to 6, wherein the light-emitting element includes a support substrate and a plurality of light-emitting portions arranged separately on the support substrate.

Scheme 8

The light-emitting device according to claim 7, wherein a boundary between the first layer and the second layer is located between adjacent light-emitting portions in a plan view.

Scheme 9

The light-emitting device according to claim 7 or 8, wherein the plurality of light-emitting portions are independently controllable.

Scheme 10

The light-emitting device according to any one of claims 1 to 9,

The wavelength conversion layer further comprises a third layer comprising third phosphor particles and light reflecting particles,

The concentration of light reflecting particles in the third layer is greater than the concentration of light reflecting particles in the second layer.

[ Industrial Applicability ]

The light emitting device according to the embodiment of the present disclosure is applicable to vehicle illumination such as a headlight. The light emitting device according to the embodiment of the present disclosure can be used for a backlight light source of a liquid crystal display, various lighting devices, a large display, various display devices such as advertisement and destination guidance, and an image reading device, a projection device, and the like in a digital video camera, a facsimile machine, a copier, a scanner, and the like.

Claims

1. A light emitting device, comprising:

A light emitting element having a light emitting surface;

a wavelength conversion layer having a lower surface and an upper surface located on the opposite side of the lower surface, and arranged on the light emitting element in such a manner that the lower surface faces the light emitting surface;

The wavelength conversion layer includes a first layer and a second layer, the first layer includes first phosphor particles, and the second layer includes second phosphor particles and light reflecting particles.

The upper surface and the lower surface of the wavelength conversion layer include the first layer and the second layer.

2. The light emitting device according to claim 1, wherein:

The invention also includes a light-transmitting component arranged on the wavelength conversion layer.

3. The light emitting device according to claim 1, wherein:

The first phosphor particles of the first layer and the second phosphor particles of the second layer include the same phosphor material.

4. The light emitting device according to claim 1, wherein:

In the wavelength conversion layer, the first layer is in contact with the second layer.

5. The light emitting device according to claim 4, wherein:

In the wavelength conversion layer, a boundary between the first layer and the second layer is inclined relative to an upper surface of the wavelength conversion layer.

6. The light emitting device according to claim 1, wherein:

The invention further includes a covering member, which covers the side surfaces of the light emitting element and the side surfaces of the wavelength conversion layer.

7. The light emitting device according to claim 1, wherein:

The light emitting element includes a supporting substrate and a plurality of light emitting portions separately arranged on the supporting substrate.

8. The light emitting device according to claim 7, wherein:

In a plan view, a boundary between the first layer and the second layer is located between adjacent light-emitting portions.

9. The light emitting device according to claim 7, wherein:

The plurality of light emitting units can be independently controlled.

10. The light emitting device according to claim 1, wherein:

The wavelength conversion layer further comprises a third layer including third phosphor particles and light reflecting particles.

The concentration of light-reflective particles in the third layer is greater than the concentration of light-reflective particles in the second layer.