Light-emitting device

Abstract

To make a luminance difference large between a light-emitting element in an illuminating state and a light-emitting element in a non-illuminating state in a light-emitting device which has a plurality of light-emitting elements.SOLUTION: A light-emitting device comprises a plurality of light-emitting elements which can be driven individually or in groups, and a wavelength conversion part which is arranged above the plurality of light-emitting elements, and the wavelength conversion part includes a plurality of first phosphor parts which are arranged above the light-emitting elements respectively, and a second phosphor part which is arranged between adjacent first phosphor parts and also includes an infrared phosphor.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a light emitting device. [Background technology]

[0002] A lighting device is known that includes a plurality of light-emitting elements that emit blue light and a phosphor layer in which phosphors that are excited by the blue light to emit light other than blue are dispersed in a transparent substrate. The phosphor layer is divided into, for example, a red phosphor region in which red phosphors that are excited by the blue light to emit red light are dispersed in the transparent substrate, and a non-red phosphor region in which phosphors that are excited by the blue light to emit light of a color other than red are dispersed in the transparent substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-123918 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure aims to increase the difference in luminance between a light-emitting element that is on and a light-emitting element that is off in a light-emitting device having a plurality of light-emitting elements. [Means for solving the problem]

[0005] A light emitting device according to one embodiment of the present disclosure comprises a plurality of light emitting elements that can be driven individually or in groups, and a wavelength conversion unit arranged above the plurality of light emitting elements, wherein the wavelength conversion unit includes a plurality of first phosphor units arranged above each of the plurality of light emitting elements, and a second phosphor unit arranged between adjacent first phosphor units and including an infrared phosphor. [Effects of the Invention]

[0006] According to an embodiment of the present disclosure, in a light emitting device having a plurality of light emitting elements, it is possible to increase the difference in luminance between the light emitting elements that are lit and the light emitting elements that are turned off. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view schematically illustrating a light emitting device according to an embodiment. [Figure 2] 1 is a perspective view schematically illustrating a light emitting device according to an embodiment, with part of the configuration thereof omitted. [Figure 3] FIG. 1 is a top view schematically illustrating a light emitting device according to an embodiment. [Figure 4] FIG. 4 is a partial cross-sectional view taken along line IV-IV in FIG. [Figure 5A] 5A to 5C are partial cross-sectional views illustrating a manufacturing process of the light emitting device according to the embodiment. [Figure 5B] 5A to 5C are partial cross-sectional views illustrating a manufacturing process of the light emitting device according to the embodiment. [Figure 5C] 5A to 5C are partial cross-sectional views illustrating a manufacturing process of the light emitting device according to the embodiment. [Figure 5D] 5A to 5C are partial cross-sectional views illustrating a manufacturing process of the light emitting device according to the embodiment. [Figure 6] 10 is a partial cross-sectional view schematically showing a light emitting device according to Modification 1. FIG. [Figure 7] FIG. 10 is a partial cross-sectional view schematically showing a light emitting device according to Modification 2. [Figure 8] FIG. 10 is a partial cross-sectional view schematically showing a light emitting device according to Modification 3. [Figure 9] FIG. 10 is a partial top view schematically showing a light emitting device according to Modification 4. [Figure 10] FIG. 11 is a partial cross-sectional view schematically showing a light emitting device according to Modification 5. [Figure 11] FIG. 13 is a partial cross-sectional view schematically showing a light emitting device according to a sixth modification. [Figure 12] FIG. 13 is a partial cross-sectional view schematically showing a light emitting device according to a seventh modification. [Figure 13] 13 is a partial cross-sectional view schematically showing a light emitting device according to Modification 8. FIG. [Figure 14] FIG. 10 is a partial cross-sectional view showing a first modification of the process for fabricating a wavelength conversion portion. [Figure 15] FIG. 13 is a partial cross-sectional view schematically showing a light emitting device according to a ninth modification. [Figure 16] FIG. 10 is a partial cross-sectional view showing a second modification of the process for fabricating a wavelength conversion portion. [Figure 17] FIG. 10 is a partial cross-sectional view showing a third modified example of the process for producing a wavelength conversion portion. DETAILED DESCRIPTION OF THE INVENTION

[0008] A light-emitting device according to the present disclosure (hereinafter, sometimes referred to as a "light-emitting device according to an embodiment") will be described below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present disclosure. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or components.

[0009] Furthermore, the embodiments described below are intended to exemplify light-emitting devices embodying the technical concepts of the present disclosure and are not intended to limit the scope of the present disclosure. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended for illustrative purposes only and are not intended to limit the scope of the present disclosure. Furthermore, the content described in one embodiment may also be applied to other embodiments and modified examples. Furthermore, the size and positional relationships of components shown in the drawings may be exaggerated for clarity. Furthermore, to avoid overly complex drawings, schematic diagrams may be used in which some elements are omitted, or end views may be used as cross-sectional views showing only the cut surface.

[0010] The light emitting device according to the present disclosure comprises a plurality of light emitting elements that can be driven individually or in groups, and a wavelength conversion unit arranged above the plurality of light emitting elements, wherein the wavelength conversion unit includes a plurality of first phosphor units arranged above each of the plurality of light emitting elements, and a second phosphor unit arranged between adjacent first phosphor units and including an infrared phosphor.

[0011] [Light-emitting device 1] As an example of a light emitting device according to the present disclosure, a light emitting device 1 will be described. Fig. 1 is a perspective view schematically showing the light emitting device according to the embodiment. Fig. 2 is a perspective view schematically showing the light emitting device according to the embodiment with part of the configuration omitted. Fig. 3 is a top view schematically showing the light emitting device according to the embodiment. Fig. 4 is a partial cross-sectional view taken along line IV-IV in Fig. 3.

[0012] In each drawing, for reference, mutually orthogonal X-, Y-, and Z-axes are shown as necessary. The direction parallel to the X-axis is called the X-direction, the direction parallel to the Y-axis is called the Y-direction, and the direction parallel to the Z-axis is called the Z-direction. In the X-direction, the direction in which the arrow points is called the +X-direction, and the direction opposite the +X-direction is called the -X-direction. In the Y-direction, the direction in which the arrow points is called the +Y-direction, and the direction opposite the +Y-direction is called the -Y-direction. In the Z-direction, the direction in which the arrow points is called the +Z-direction, and the direction opposite the +Z-direction is called the -Z-direction. However, these do not limit the orientation of the light-emitting device when in use, and the orientation of the light-emitting device is arbitrary. As an example, viewing an object from the +Z-direction toward the -Z-direction is called top view.

[0013] The light emitting device 1 includes, as a minimum configuration, a plurality of light emitting elements 30 and a wavelength converting section 40. In the example of FIGS. 1 to 4, the light emitting device 1 further includes a substrate 10, a package substrate 20, a light blocking member 50, a wire 110, and a covering member 120.

[0014] 1 to 4, the substrate 10 is mounted on the upper surface 20a of the package substrate 20. On the upper surface 10a of the substrate 10, a first terminal 11 is arranged outside the area where the plurality of light-emitting elements 30 are arranged. The package substrate 20 is larger than the substrate 10 in a top view. On the upper surface 20a of the package substrate 20, a second terminal 22 is arranged outside the area where the substrate 10 is mounted. The first terminal 11 of the substrate 10 is electrically connected to the second terminal 22 of the package substrate 20 by a wire 110. The first terminal 11, the second terminal 22, and the wire 110 are covered by a covering member 120 that is arranged on the periphery of the upper surface 10a of the substrate 10 and on the periphery of the upper surface 20a of the package substrate 20. The light-emitting elements 30 and the wavelength converting unit 40 may be located inside the covering member 120 in a top view.

[0015] For convenience of illustration, the entire wavelength converting portion 40 and part of the covering member 120 are omitted in FIG. 2, and only the light emitting element 30 and part of the wire 110 are visible.

[0016] The plurality of light-emitting elements 30 are disposed, for example, on the upper surface 10a of the substrate 10. The electrode 35 of each light-emitting element 30 is electrically connected, for example, to a wiring portion 12 disposed on the upper surface 10a of the substrate 10. The plurality of light-emitting elements 30 can be disposed, for example, in a matrix when viewed from above. The plurality of light-emitting elements 30 can be driven individually or in groups. The plurality of light-emitting elements 30 can be driven individually or in groups, for example, by using the substrate 10 as a semiconductor integrated circuit substrate such as an ASIC (Application Specific Integrated Circuit), or by an electrical circuit provided outside the light-emitting device 1. Note that being able to be driven individually or in groups includes a configuration in which each of the plurality of light-emitting elements can be driven individually, a configuration in which the plurality of light-emitting elements can be divided into groups and driven separately, and a configuration in which some light-emitting elements can be driven individually and some light-emitting elements can be driven separately in groups.

[0017] The wavelength conversion section 40 is disposed above the plurality of light-emitting elements 30. The wavelength conversion section 40 includes a plurality of first phosphor sections 41 and a second phosphor section 42. The plurality of first phosphor sections 41 are disposed above the plurality of light-emitting elements 30, respectively. When the plurality of light-emitting elements 30 are arranged in a matrix when viewed from above, the plurality of first phosphor sections 41 are also similarly arranged in a matrix when viewed from above.

[0018] The second phosphor sections 42 are disposed between adjacent first phosphor sections 41. For example, the second phosphor sections 42 can be disposed in a lattice pattern so as to surround each of the plurality of light-emitting elements 30 when viewed from above. The second phosphor sections 42 may be disposed between all of the first phosphor sections 41 arranged in a matrix, or may be disposed between some of the first phosphor sections 41.

[0019] The first phosphor section 41 converts the light incident from the light emitting element 30 into light of a different wavelength and emits it. The first phosphor section 41 may emit a portion of the incident light without converting it into light of a different wavelength, or may convert all of the incident light into light of a different wavelength and emit it. The thicknesses of the first phosphor sections 41 may or may not be the same. Here, "same thickness" means that the thickness of one first phosphor section is 95% or more and 105% or less of the thickness of the other first phosphor sections.

[0020] The second phosphor section 42 includes an infrared phosphor. Therefore, the second phosphor section 42 can convert light incident from the light-emitting element 30 into infrared light and emit the infrared light. Furthermore, the second phosphor section 42 can convert light converted by the first phosphor section 41 and incident on the second phosphor section 42 into infrared light and emit the infrared light. The second phosphor section 42 may emit a portion of the incident light without converting it to infrared light, or may convert all of the incident light into infrared light and emit the infrared light. The infrared phosphor included in the second phosphor section 42 is, for example, a phosphor with an emission peak wavelength of 850 nm or more and 1100 nm or less. The thicknesses of the second phosphor sections 42 may or may not be the same. Furthermore, the thickness of the second phosphor section 42 may or may not be the same as the thickness of the first phosphor section 41.

[0021] The light-shielding member 50 is preferably disposed between adjacent light-emitting elements 30. The light-shielding member 50 includes, for example, a light-reflective material. The light-shielding member 50 may include a light-absorbing material instead of a light-reflective material. The light-shielding member 50 may continuously cover the side and bottom surfaces of each light-emitting element 30, and may cover the bottom surface of each light-emitting element 30 and the side surfaces of the electrodes 35.

[0022] In the light emitting device 1, the plurality of light emitting elements 30 can be driven individually or in groups, so that there may be cases where one of adjacent light emitting elements 30 is on and the other is off. In this case, light from the on light emitting element 30 that attempts to travel toward the off light emitting element 30 is absorbed by the second phosphor section 42, making it difficult for the light to reach the off light emitting element 30. Furthermore, because the second phosphor section 42 contains an infrared phosphor, the light absorbed by the second phosphor section 42 is converted into infrared light, which is invisible light. This makes it possible to increase the difference in brightness between the on light emitting element 30 and the off light emitting element 30.

[0023] Furthermore, the second phosphor section 42 absorbs light from the light emitting element 30 and emits infrared light. Therefore, compared to when a black resin that does not emit infrared light is arranged between adjacent first phosphor sections 41 instead of the second phosphor section 42, heat generation between adjacent first phosphor sections 41 can be reduced. Also, compared to when a white resin is arranged between adjacent first phosphor sections 41, multiple reflections of light do not occur between the adjacent first phosphor sections 41 and the white resin, and it is possible to reduce the boundary between the first phosphor section 41 and the white resin from appearing to be bright (a bright line) when viewed from above.

[0024] Furthermore, when the light-emitting device 1 is used as a light source for a vehicle headlight, the infrared light emitted by the second phosphor unit 42 can be used as light for a detection sensor for autonomous driving. This allows for a more compact detection system than when a separate infrared light source is provided, and by using the light-emitting device 1 in combination with a separate infrared light source, the output of the infrared light can be increased, making it easier to improve the accuracy of the detection sensor. Furthermore, when the light-emitting device 1 is used as a light source for a vehicle headlight, the infrared light emitted by the second phosphor unit 42 can melt snow that has accumulated on the headlight. In particular, when the infrared phosphor contained in the second phosphor unit 42 is a phosphor with an emission peak wavelength of 850 nm or more and 1100 nm or less, the detection accuracy of the detection sensor is further improved and snow is more likely to melt.

[0025] Furthermore, the light emitting device 1 preferably includes a light-blocking member 50 containing a light-reflective material and disposed between adjacent light emitting elements 30. By including the light emitting device 1 in the light-blocking member 50, it is possible to reduce the amount of light emitted from one light emitting element 30 being emitted toward another adjacent light emitting element 30. This makes it possible to further increase the difference in luminance between the light emitting element 30 that is turned on and the light emitting element 30 that is turned off.

[0026] Each component of the light emitting device 1 will be described below.

[0027] (Substrate 10) The substrate 10 includes a flat support member and a wiring portion disposed on the upper surface side of the support member. The substrate 10 has an element mounting region 10r on its upper surface 10a where a plurality of light-emitting elements 30 are mounted, and a wiring portion 12 is disposed in the element mounting region 10r. The substrate 10 has a plurality of first terminals 11 disposed on the upper surface 10a outside the element mounting region 10r, and the first terminals 11 are electrically connected to the wiring portion 12 disposed in the element mounting region 10r.

[0028] In top view, the substrate 10 and the element mounting region 10r may be, for example, a rectangle having long and short sides. For example, a plurality of light-emitting elements 30 are mounted in a matrix in the element mounting region 10r. The light-emitting elements 30 are electrically connected to one of the first terminals 11. The light-emitting elements 30 may be connected in series or parallel to the first terminals 11 in groups of a predetermined number. For example, the element mounting region 10r may have a long side length of 8 mm or more and 18 mm or less, and a short side length of 2 mm or more and 6 mm or less.

[0029] Each of the first terminals 11 has, for example, a substantially circular, elliptical, or rectangular shape. The first terminals 11 are spaced apart from one another and arranged in a row along opposing long sides of the rectangular element mounting region 10r on the upper surface 10a of the substrate 10, sandwiching the element mounting region 10r. The interval between adjacent first terminals 11 may or may not be constant. The interval between adjacent first terminals 11 can be, for example, 20 μm or more and 100 μm or less. One end of a wire 110 is connected to the first terminal 11.

[0030] The substrate 10 is, for example, a semiconductor substrate such as silicon. On the upper surface 10a of the substrate 10, areas where wiring portions and terminals are not arranged are covered with, for example, an insulating film. Wiring portions may also be arranged inside or on the lower surface of the support member. For example, the substrate 10 may be an integrated circuit substrate on which circuits for individually driving and controlling the plurality of light-emitting elements 30 are integrated.

[0031] Examples of materials for the first terminal 11 and the wiring portion 12 include metals such as Cu, Ag, Au, Al, Pt, Ti, W, Pd, Fe, and Ni, and / or alloys containing at least these metals.

[0032] (Package substrate 20) The package substrate 20 includes a flat base material and a wiring portion disposed at least on the upper surface side of the base material. The package substrate 20 has a substrate mounting area 20r on its upper surface 20a for mounting the substrate 10, and further includes second terminals 22 on the upper surface 20a outside the substrate mounting area 20r. The substrate mounting area 20r is an area on which the substrate 10 is mounted. The substrate mounting area 20r is set as an area having approximately the same area as the shape of the substrate 10 when viewed from above. If the substrate 10 is rectangular when viewed from above, the substrate mounting area 20r can also be rectangular. Here, "approximately the same" is intended to include within an allowable range errors caused by component tolerances and mounting tolerances.

[0033] Each second terminal 22 has, for example, a substantially circular, oval, or rectangular shape. The second terminals 22 are spaced apart from one another on the upper surface 20a of the package substrate 20 and arranged in a row along opposing long sides of the rectangle, sandwiching the substrate mounting region 20r. The interval between adjacent second terminals 22 may or may not be constant. The interval between adjacent second terminals 22 may be, for example, 20 μm or more and 100 μm or less. The other end of the wire 110 is connected to the second terminal 22.

[0034] The base material constituting the package substrate 20 is preferably a material with high heat dissipation properties, and more preferably a material with high light-shielding properties and base material strength. Specific examples include metals such as Al and Cu; ceramics such as aluminum oxide, aluminum nitride, silicon nitride, and mullite; resins such as phenolic resin, epoxy resin, polyimide resin, BT resin (bismaleimide triazine resin), and polyphthalamide (PPA); and composite materials composed of resin and metal or ceramic (e.g., a substrate with a metal component disposed within a resin). The base material may be flat, or may have a recess on its upper surface. In this case, the package substrate 20 has a recess whose bottom serves as a substrate mounting area 20r, and the substrate 10 can be mounted within the recess.

[0035] The package substrate 20 may include a wiring portion on the surface of the substrate mounting region 20r for mounting the substrate 10 thereon.

[0036] (light-emitting element) The light-emitting element 30 may have, for example, a rectangular shape with one side measuring 20 μm to 1000 μm when viewed from above. The light-emitting element 30 has positive and negative electrodes 35 on the same side, and is flip-chip mounted on the substrate 10 with the side having the electrodes 35 facing downward. In this case, the upper surface opposite to the surface on which the electrodes 35 are arranged is the main light extraction surface of the light-emitting element 30.

[0037] In the light-emitting device 1, the light-emitting elements 30 are aligned on the substrate 10 at predetermined intervals in each row and column. The size and number of the light-emitting elements 30 can be appropriately selected depending on the desired configuration of the light-emitting device. The light-emitting device 1 can include, for example, 100 to 2,000,000 light-emitting elements, preferably 1,000 to 500,000 light-emitting elements, and more preferably 3,000 to 150,000 light-emitting elements. When the light-emitting device 1 includes 100 or more light-emitting elements, road projection including simple messaging becomes possible when the light-emitting device 1 is used for road projection illuminated from vehicle headlights. Furthermore, when the light-emitting device 1 includes 2,000,000 or fewer light-emitting elements, high-resolution road projection is realized, the light-emitting device 1 can be made compact, and sufficient illuminance can be emitted when each light-emitting element 30 is individually lit.

[0038] The light-emitting element 30 is, for example, a light-emitting diode. The light-emitting element 30 includes a semiconductor structure. The semiconductor structure 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. The active layer may have a single quantum well (SQW) structure or a multiple quantum well (MQW) structure including multiple well layers. The active layer is configured to be able to emit, for example, visible light or ultraviolet light.

[0039] The semiconductor structure may include multiple light-emitting sections, each including an n-side semiconductor layer, an active layer, and a p-side semiconductor layer. When the semiconductor structure includes multiple light-emitting sections, each light-emitting section may include well layers with different emission peak wavelengths or well layers with the same emission peak wavelength. The same emission peak wavelength also includes cases where the emission peak wavelengths vary by a few nanometers. The combination of emission peak wavelengths of the multiple light-emitting sections can be appropriately selected. For example, when the semiconductor structure includes two light-emitting sections, the combination of light emitted by each light-emitting section may be blue light with blue light, green light with green light, ultraviolet light with ultraviolet light, blue light with green light, blue light with ultraviolet light, or green light with ultraviolet light. For example, when the semiconductor structure includes three light-emitting sections, the combination of light emitted by each light-emitting section may be blue light, green light, and red light. Each light-emitting section may include one or more well layers with emission peak wavelengths different from those of the other well layers.

[0040] As the light emitting element 30, for example, a light emitting element capable of emitting blue light (light having a wavelength of 410 nm or more and 490 nm or less) can be used. However, the color of light emitted by the light emitting element 30 can be selected from any wavelength depending on the application. For example, a light emitting element for blue (light having a wavelength of 410 nm or more and 490 nm or less) or green (light having a wavelength of more than 490 nm and 565 nm or less) can be made of nitride-based semiconductors (In x Al y Ga 1-x-y N (0≦x, 0≦y, x+y≦1), GaP, etc. can be used. As a red light emitting element (light with a wavelength of 610 nm or more and 700 nm or less), GaAlAs, AlInGaP, etc. can be used in addition to nitride-based semiconductor elements.

[0041] The light-emitting element 30 is bonded to the wiring portion 12 arranged in the element mounting region 10r of the substrate 10 by a conductive bonding member. When flip-chip mounting the light-emitting element 30 on the substrate 10, bumps made of a metal material such as Au, Ag, Cu, or Al can be used as the bonding member. Alternatively, solder such as an AuSn-based alloy or Sn-based lead-free solder can be used as the bonding member. Alternatively, a conductive adhesive made of resin containing conductive particles of metal or the like can be used as the bonding member. A plating method may be used to bond the light-emitting element 30 to the substrate 10. Examples of plating materials include Cu and Au. Alternatively, the electrodes 35 of the light-emitting element 30 and the wiring portion 12 of the substrate 10 may be in direct contact without a bonding member.

[0042] (First phosphor part) The first phosphor portion 41 includes, for example, a resin and a phosphor. Examples of the resin include known translucent resins such as silicone resin and epoxy resin. Among them, silicone resin (specifically, translucent resins such as phenyl silicone resin and dimethyl silicone resin) is preferably used, as it has excellent reliability.

[0043] The phosphor is an yttrium-aluminum-garnet phosphor (e.g., (Y,Gd)3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphors (e.g., Ca 10 (PO4)6Cl2:Eu), SAE-based phosphors (e.g., Sr4Al 14 O 25 :Eu), chlorosilicate phosphors (e.g., Ca8MgSiO 16 Cl2:Eu), silicate-based phosphors (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon-based phosphors (e.g., (Si,Al)3(O,N)4:Eu) or α-sialon-based phosphors (e.g., Ca(Si,Al) 12 (O,N)16 : Oxynitride phosphors such as Eu), LSN phosphors (e.g., (La, Y)3Si6N 11 : Ce), BSESN phosphors (e.g., (Ba, Sr)2Si5N8: Eu), SLA phosphors (e.g., SrLiAl3N4: Eu), CASN phosphors (e.g., CaAlSiN3: Eu) or SCASN phosphors (e.g., (Sr, Ca)AlSiN3: Eu) and other nitride phosphors, KSF phosphors (e.g., K2SiF6: Mn), KSAF phosphors (e.g., K2(Si 1-x Al x )F 6-x : Mn where x satisfies 0 < x < 1.) or fluoride phosphors such as MGF phosphors (e.g., 3.5MgO·0.5MgF2·GeO2: Mn), quantum dots having a perovskite structure (e.g., (Cs, FA, MA)(Pb, Sn)(F, Cl, Br, I)3 where FA and MA represent formamidinium and methylammonium, respectively.), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag, Cu)(In, Ga)(S, Se)2) and the like can be used.

[0044] When the light-emitting element 30 can emit blue light, the first phosphor part 41 can contain, for example, a phosphor that can be excited by blue light and emit yellow light. In this case, examples of the phosphor contained in the first phosphor part 41 include yttrium aluminum garnet-based phosphors (e.g., (Y, Gd)3(Al, Ga)5O 12 : Ce). According to such a configuration, white light can be obtained by mixing the blue light that has passed through the first phosphor part 41 and the yellow light emitted by the first phosphor part 41.

[0045] (The second phosphor part) The second phosphor section 42 includes, for example, a resin and an infrared phosphor. The resin may be the same as the resin used for the first phosphor section 41. The second phosphor section 42 may include a light-reflecting material. Examples of the light-reflecting material include titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass filler.

[0046] The width of the second phosphor portion 42 is, for example, 3 μm or more and 80 μm or less, and the infrared phosphor is, for example, a quantum dot phosphor having an average particle size of 50 nm or less. The infrared phosphor is, for example, a quantum dot phosphor containing at least one of Ag and Cu, and at least one of Se and S. By using a quantum dot phosphor with a small particle size as the infrared phosphor, it is possible to increase the filling amount of the infrared phosphor and improve the infrared light output even when the distance between adjacent first phosphor portions 41 is narrow, at 3 μm or more and 80 μm or less.

[0047] The average particle size of the infrared phosphor may be determined, for example, from a transmission electron microscope (TEM) image. Specifically, the particle size of each particle refers to the longest line segment that connects any two points on the periphery of the particle observed in the TEM image and exists within the particle.

[0048] However, when the particle has a rod shape, the length of the minor axis is considered to be the particle size. Here, rod-shaped particles refer to particles that have a minor axis and a major axis perpendicular to the minor axis in a TEM image, and the ratio of the length of the major axis to the length of the minor axis is greater than 1.2. Rod-shaped particles are observed in TEM images as, for example, quadrangular, including rectangular, elliptical, or polygonal shapes. The cross-sectional shape of the rod, which is a plane perpendicular to the major axis, may be, for example, circular, elliptical, or polygonal. Specifically, for rod-shaped particles, the length of the major axis refers to the length of the longest line segment connecting any two points on the periphery of the particle in the case of an elliptical shape; and in the case of a rectangular or polygonal shape, refers to the length of the longest line segment connecting any two points on the periphery of the particle that is parallel to the longest side defining the periphery. The length of the minor axis refers to the length of the longest line segment connecting any two points on the periphery that is perpendicular to the line segment defining the length of the major axis.

[0049] The average particle size of an infrared phosphor is determined by measuring the particle size of all measurable particles observed in a TEM image at magnifications between 50,000x and 150,000x, and then calculating the arithmetic mean of those particle sizes. Here, "measurable" particles are those whose entire outline can be observed in a TEM image. Therefore, particles whose outline is partially not included in the imaging range and thus "cut off" are not measurable. If a single TEM image contains 100 or more measurable particles, that TEM image is used to determine the average particle size. On the other hand, if a single TEM image contains fewer than 100 measurable particles, the imaging location is changed, additional TEM images are acquired, and the particle sizes of 100 or more measurable particles in two or more TEM images are measured to determine the average particle size.

[0050] (Light blocking material) The light-shielding member 50 is preferably made of a soft resin with relatively low elasticity and excellent shape-following ability. Resin materials with good transparency and insulating properties, such as thermosetting resins such as epoxy resins and silicone resins, are preferably used as the material for the light-shielding member 50. Furthermore, the light-shielding member 50 is preferably made of a resin containing a light-reflecting material in its base resin. The light-reflecting material can be preferably the light-reflecting material described above. The light-shielding member 50 may contain a light-absorbing material instead of the light-reflecting material. The light-absorbing material can be preferably a light-absorbing material such as a pigment, carbon black, titanium black, or graphite.

[0051] (wire) The wires 110 can be made of metals such as Au, Ag, Cu, Pt, and Al and / or alloys containing at least these metals. Au, which has excellent thermal resistance, is particularly preferable. The diameter of the wires 110 can be, for example, 15 μm to 50 μm. The wires 110 can be arranged across the long sides of the substantially rectangular substrate 10 in a top view, for example, so as to be substantially perpendicular to the long sides. Furthermore, among the multiple wires 110 arranged in a row along the long sides of the substrate 10, the wires 110 located in the center of the row can be arranged so as to be substantially perpendicular to the long sides of the substrate 10 in a top view, as described above, while the wires 110 located at the ends of the row can be arranged diagonally relative to the long sides of the substrate 10 in a top view. The interval at which the wires 110 are aligned can be 20 μm to 100 μm.

[0052] (Covering material) The covering member 120 is a light-shielding member that covers the wires 110 outside the element mounting region 10r. Note that, as an example, the covering member 120 is arranged in a frame shape in a top view so as to cover the wires 110 and surround the element mounting region 10r.

[0053] The covering member 120 is disposed at a distance from the light emitting element 30 in a top view. The covering member 120 is preferably disposed so that its height is greatest directly above the top of the wire 110. In other words, the covering member 120 is preferably disposed so that the top of the covering member 120 overlaps the top of the wire 110.

[0054] The covering member 120 may be, for example, a resin containing a filler with light-blocking properties. Examples of resins that can be used as the base material include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, and acrylic resin. Examples of fillers with light-blocking properties include the light-reflecting or light-absorbing materials that may be contained in the light-blocking member 50 described above. The exterior color of the covering member 120 may be white, which has excellent light reflectivity, black, which has excellent light absorption, or gray, which has both light reflectivity and light absorption properties. The covering member 120 may also be formed by laminating multiple resin layers. In particular, in consideration of deterioration of the resin due to light absorption, it is preferable that the covering member 120 use a white resin with light reflectivity on at least the outermost surface.

[0055] The light emitting device 1 having the above configuration can be used, for example, as a light source for a vehicle headlight. For example, it can be used as a light source that can select an illumination area and irradiate it with light, such as a headlight equipped with an ADB (Adaptive Driving Beam) function, a road surface projection function, etc. In this case, since the light emitting device 1 can increase the difference in luminance between the light emitting element that is turned on and the light emitting element that is turned off, it is possible to realize a headlight with good contrast using a single light source.

[0056] [Method of manufacturing the light emitting device 1] Hereinafter, each manufacturing step of the manufacturing method of the light emitting device according to the embodiment will be described with reference to the drawings.

[0057] 5A to 5D are partial cross-sectional views illustrating the manufacturing process of the light emitting device according to the embodiment.

[0058] (Step of mounting the light emitting element 30 on the substrate 10) First, as shown in FIG. 5A, a structure is prepared in which a plurality of light-emitting elements 30 are mounted on a substrate 10. Specifically, a substrate 10 is prepared having first terminals 11 and wiring portions 12 on an upper surface 10a side. The substrate 10 can be prepared, for example, by preparing a flat support member made of silicon or the like, and forming the first terminals 11 and wiring portions 12 by plating, sputtering, vapor deposition, or the like. A plurality of light-emitting elements 30 are also prepared. The light-emitting elements 30 can be prepared by undergoing some or all of multiple steps, such as a step of forming a semiconductor laminate and a step of forming electrodes. Note that in the description of the manufacturing method, "preparing" a component does not necessarily mean manufacturing the component, but also includes acquiring the component, such as purchasing or receiving the component.

[0059] Next, the light-emitting elements 30 are mounted on the element mounting region 10r of the substrate 10. The light-emitting elements 30 can be mounted on the element mounting region 10r on the upper surface 10a of the substrate 10 by flip-chip mounting or the like. The electrodes 35 of each light-emitting element 30 are electrically connected to the wiring portion 12 arranged on the upper surface 10a of the substrate 10.

[0060] (Step of placing the light blocking member 50) 5B, after the light emitting elements 30 are placed on the substrate 10, a light blocking member 50 can be placed between adjacent light emitting elements 30 as needed. For example, uncured white resin or the like is caused to flow between adjacent light emitting elements 30 and onto the underside of the light emitting elements 30. Thereafter, the white resin or the like is cured, thereby placing the light blocking member 50.

[0061] (Step of placing the substrate 10 on the package substrate 20) Next, a package substrate 20 is prepared, which has a substrate mounting area 20r on which the substrate 10 is mounted, and second terminals 22 located outside the substrate mounting area 20r, on its upper surface 20a. The package substrate 20 can be prepared, for example, by forming wiring portions such as Cu and the second terminals 22 on a flat support member made of metal, ceramic, or the like by plating, sputtering, vapor deposition, or the like. Next, the substrate 10 on which the light-emitting element 30 is mounted is placed on the substrate mounting area 20r of the package substrate 20. The substrate 10 and the package substrate 20 can be joined via a joining member such as a sintered body containing Ag or a resin material.

[0062] (Process of connecting with wire 110) Next, the first terminal 11 of the substrate 10 and the second terminal 22 of the package substrate 20 are connected by the wire 110. For example, the wire 110 is first connected to the first terminal 11 of the substrate 10, and then connected to the second terminal 22 of the package substrate 20. By connecting the wire 110 in this order, the top of the wire 110 can be positioned closer to the first terminal 11. This allows the wire 110 to be positioned along the step between the substrate 10 and the package substrate 20. Therefore, in the step of arranging the covering member 120, which will be described later, the amount of resin positioned below the wire 110 is reduced, and the risk of the wire 110 being broken due to thermal expansion of the covering member 120 can be reduced.

[0063] (Process for Producing Wavelength Converter 40) Next, as shown in FIG. 5C , a wavelength conversion section 40 including a first phosphor section 41 and a second phosphor section 42 is fabricated. First, as shown in the top row, a sheet-shaped member having a predetermined size is prepared as the first phosphor section 41. Then, as shown in the second row from the top, grooves 41x are formed in the sheet-shaped first phosphor section 41. The grooves 41x can be formed, for example, by irradiating the top surface of the first phosphor section 41 with laser light. For example, an excimer laser can be used to form the grooves 41x. The spot diameter of the laser light on the top surface of the first phosphor section 41 is, for example, 0.3 μm or more and 10 μm or less. Therefore, it is possible to form relatively narrow grooves 41x. Note that a mechanical method such as dicing may be used to form relatively wide grooves 41x. Next, as shown in the third row from the top, the second phosphor section 42 is placed in the grooves 41x. The second phosphor section 42 can be arranged, for example, by dropping uncured resin containing an infrared phosphor into the groove 41x by potting and curing it. The second phosphor section 42 may extend from inside the groove 41x onto the upper surface of the first phosphor section 41. Next, as shown in the fourth row from the top, the upper surface of the second phosphor section 42 is polished to expose the upper surface of the first phosphor section 41. The upper surfaces of the first phosphor section 41 and the second phosphor section 42 become, for example, flush with each other. Next, as shown in the fifth row from the top, the lower surface of the first phosphor section 41 is polished to expose the lower surface of the second phosphor section 42. The lower surfaces of the first phosphor section 41 and the second phosphor section 42 become, for example, flush with each other.

[0064] The step shown in FIG. 5C may be performed before the step shown in FIG. 5A and / or FIG. 5B, or may be performed in parallel with the step shown in FIG. 5A and / or FIG. 5B.

[0065] (Step of placing the wavelength conversion section 40) 5D, the wavelength conversion section 40 is placed on the light emitting element 30 and the light blocking member 50 arranged on the upper surface 10a of the substrate 10. At this time, alignment is performed so that the first phosphor section 41 is placed on the light emitting element 30 and the second phosphor section 42 is placed on the light blocking member 50. The wavelength conversion section 40 can be fixed onto the light emitting element 30 and the light blocking member 50 via a light-transmitting bonding member such as resin, for example.

[0066] (Step of placing the covering member 120) Next, a covering member 120 that covers the first terminals 11, the second terminals 22, and the wires 110 is placed on the outer periphery of the upper surface 10a of the substrate 10 and on the outer periphery of the upper surface 20a of the package substrate 20. The covering member 120 can be placed, for example, by supplying uncured resin to a predetermined position using a dispenser or the like and then curing it. Through the above steps, the light emitting device 1 is completed.

[0067] <Modification> FIG. 6 is a partial cross-sectional view schematically illustrating a light-emitting device according to Modification 1. As in the light-emitting device 1A shown in FIG. 6, the upper surface of the second phosphor section 42 may be convex, and the apex of the convex shape may be higher in the height direction than the upper surface of the first phosphor section 41. When the upper surface of the second phosphor section 42 is convex, the light extraction efficiency of the infrared light is higher than when the upper surface is flat, thereby improving the output of the infrared light. Furthermore, since the second phosphor section 42 can absorb more light emitted laterally from the first phosphor section 41, the difference in brightness between the light-emitting element 30 when it is turned on and the light-emitting element 30 when it is turned off can be increased.

[0068] FIG. 7 is a partial cross-sectional view schematically illustrating a light emitting device according to Modification 2. As in the light emitting device 1B illustrated in FIG. 7, a convex lens 60 may be further provided above the first phosphor section 41. This improves the light extraction efficiency of the light emitted from the light emitting element 30 and the light emitted from the first phosphor section 41. The convex lens 60 may be made of a material that easily transmits visible light, such as glass, silicon, quartz, synthetic quartz, sapphire, or transparent ceramics. The convex lens 60 may be fixed onto the first phosphor section 41 via a translucent bonding member such as resin. Alternatively, the convex lens 60 may be formed on the first phosphor section 41 by die molding.

[0069] FIG. 8 is a partial cross-sectional view schematically illustrating a light-emitting device according to Modification 3. As in light-emitting device 1C shown in FIG. 8, the light-emitting device may further include a flat light-transmitting plate 70 having an upper surface and a lower surface. The light-transmitting plate 70 has, on its lower surface, a plurality of recesses 71 and flat portions 72 located between adjacent recesses 71. The recesses 71 are disposed above each of the first phosphor portions 41, and the flat portions 72 are disposed above the second phosphor portions 42. The upper surface of the light-transmitting plate 70 may be, for example, a flat surface parallel to the flat portions 72.

[0070] The light-transmitting plate 70 can be made of a material that easily transmits infrared light, such as silicon, germanium, zinc sulfide, zinc selenide, chalcogenide glass, etc. The flat portion 72 of the light-transmitting plate 70 can be fixed onto the second phosphor portion 42 via a light-transmitting bonding member such as resin.

[0071] By disposing the light-transmitting plate 70 in this manner, the infrared light that enters the light-transmitting plate 70 from the second phosphor section 42 via the flat section 72 is guided within the light-transmitting plate 70. Then, the infrared light can be emitted from the upper surface of the light-transmitting plate 70, thereby improving the output of the infrared light.

[0072] Furthermore, silicon or the like used as the material for the light-transmitting plate 70 easily transmits infrared light but is semi-transparent and therefore does not easily transmit visible light. On the other hand, the light-transmitting plate 70 has recesses 71 disposed on the first phosphor sections 41, so the thickness of the light-transmitting plate 70 located on the first phosphor sections 41 is reduced. This allows visible light to easily transmit through the recesses 71 of the light-transmitting plate 70.

[0073] Fig. 9 is a partial top view schematically showing a light emitting device according to Modification 4. As in the light emitting device 1D shown in Fig. 9, when viewed from above, there may be an area between adjacent light emitting elements 30 where the second phosphor section 42 is arranged and an area where the second phosphor section 42 is not arranged.

[0074] 9, the light emitting device 1D has two regions R in which the second phosphor section 42 is not arranged. Four light emitting elements 30 indicated by dashed lines are arranged in each region R, and the second phosphor section 42 is not arranged between adjacent light emitting elements 30. In a top view, in each region R, the first phosphor section 41 is arranged between adjacent light emitting elements 30.

[0075] The number of light-emitting elements 30 arranged in the region R is not limited to four, and may be any number equal to or greater than two. The number of light-emitting elements 30 may differ for each region R. The number of regions R in the light-emitting device 1D is not limited to two, and may be any number equal to or greater than one.

[0076] The intensity of the light emitted from the first phosphor element 41 can be increased in the region R. Therefore, when the light emitting device 1D is used as a light source for a vehicle headlight, for example, by arranging the region R in a position corresponding to a high-brightness irradiation pattern such as a high beam, the intensity of the light when the high-brightness irradiation pattern is performed can be increased.

[0077] Fig. 10 is a partial cross-sectional view schematically showing a light emitting device according to Modification 5. As in light emitting device 1E shown in Fig. 10, the light emitting device may further include a third phosphor section 80 that is disposed between adjacent light emitting elements 30 and contains an infrared phosphor. The third phosphor section 80 may continuously cover the side and bottom surfaces of each light emitting element 30, and may cover the bottom surface of each light emitting element 30 and the side surface of the electrode 35.

[0078] The infrared phosphor contained in the third phosphor section 80 is, for example, a phosphor having a higher excitation intensity at the peak wavelength of light emitted by the light emitting element 30 than the excitation intensity at the peak wavelength of light emitted by the phosphor contained in the first phosphor section 41. On the other hand, the infrared phosphor contained in the second phosphor section 42 is, for example, a phosphor having a higher excitation intensity at the peak wavelength of light emitted by the phosphor contained in the first phosphor section 41 than the excitation intensity at the peak wavelength of light emitted by the light emitting element 30. Here, the "light emitted by the phosphor" is not the excitation light from the light emitting element 30, but light emitted by the phosphor after wavelength conversion.

[0079] This allows the second phosphor element 42 and the third phosphor element 80 to efficiently convert into infrared light a large amount of light incident thereon. As a result, in the light emitting device 1E, it is possible to increase the difference in luminance between the light emitting element 30 in a lit state and the light emitting element 30 in an unlit state, and to improve the output of infrared light.

[0080] Fig. 11 is a partial cross-sectional view schematically showing a light-emitting device according to Modification 6. As in the light-emitting device 1F shown in Fig. 11, in one cross-section, the first phosphor element 41 may have a trapezoidal shape with the width of its lower surface being greater than the width of its upper surface, and the second phosphor element 42 may also have a trapezoidal shape with the width of its lower surface being smaller than the width of its upper surface. The first phosphor element 41 may have, for example, a truncated quadrangular pyramid shape with the area of ​​its lower surface being greater than the area of ​​its upper surface, and the second phosphor element 42 may have, for example, a truncated quadrangular pyramid shape with the area of ​​its lower surface being smaller than the area of ​​its upper surface.

[0081] In the light emitting device 1F, by reducing the area of ​​the emission surface side of the first phosphor section 41, the light distribution can be narrowed, thereby improving the brightness. In addition, it is possible to reduce the emission of light from a lit light emitting element 30 toward an adjacent light emitting element 30 that is not lit, thereby increasing the brightness difference between the lit light emitting element 30 and the extinguished light emitting element 30. On the other hand, by increasing the area of ​​the emission surface side of the second phosphor section 42, it is possible to improve the output of infrared light.

[0082] 12 is a partial cross-sectional view schematically illustrating a light emitting device according to Modification 7. As in the light emitting device 1G illustrated in FIG. 12, an anti-reflection film 91 may be further provided on the upper surface of the first phosphor section 41. The anti-reflection film 91 may be made of, for example, silicon dioxide or magnesium fluoride. The anti-reflection film 91 may be disposed on the upper surface of the first phosphor section 41 by, for example, vacuum deposition, sputtering, spraying, or the like.

[0083] In the light emitting device 1G, by disposing an anti-reflection film 91 on the upper surface of the first phosphor element 41, the light extraction efficiency of the light emitted from the first phosphor element 41 can be improved.

[0084] FIG. 13 is a partial cross-sectional view schematically illustrating a light-emitting device according to Modification 8. As in the light-emitting device 1H shown in FIG. 13, a DBR film 92 may be further provided on the side surface of the first phosphor element 41. The DBR film 92 can be formed by alternately laminating films with different refractive indices to a thickness of ¼ wavelength using, for example, atomic layer deposition, vacuum evaporation, or sputtering. The DBR film can be formed by including, for example, at least one oxide or nitride selected from the group consisting of Si, Ti, Zr, Nb, Ta, and Al.

[0085] For example, by disposing, as the DBR film 92, a film that transmits only light of a wavelength that excites the infrared phosphor and reflects light of other wavelengths, it is possible to improve the light extraction efficiency of the light emitted from the first phosphor section 41. Furthermore, by disposing, as the DBR film 92, a film that has a high reflectivity for infrared light, it is possible to improve the light extraction efficiency of the infrared light emitted from the second phosphor section 42.

[0086] FIG. 14 is a partial cross-sectional view showing a first variation of the process for fabricating a wavelength conversion unit. The wavelength conversion unit 40 may be fabricated using the procedure shown in FIG. 14. First, as shown in the top row, a sheet-shaped member having a predetermined size is prepared as the second phosphor unit 42. Then, as shown in the second row from the top, grooves 42x are formed in the sheet-shaped second phosphor unit 42. The grooves 42x can be formed, for example, by irradiating laser light, similar to the grooves 41x. Next, as shown in the third row from the top, the first phosphor unit 41 is placed in the grooves 42x. The first phosphor unit 41 can be placed, for example, by dropping uncured resin containing a phosphor into the grooves 42x by potting and then curing it. The first phosphor unit 41 may extend from within the grooves 42x to the upper surface of the second phosphor unit 42. Next, as shown in the fourth row from the top, the lower surface of the second phosphor unit 42 is polished to expose the lower surface of the first phosphor unit 41. The lower surface of the first phosphor element 41 and the lower surface of the second phosphor element 42 are, for example, flush with each other. Next, as shown in the fifth row from the top, the upper surface of the first phosphor element 41 is polished to expose the upper surface of the second phosphor element 42. The upper surface of the first phosphor element 41 and the upper surface of the second phosphor element 42 are, for example, flush with each other.

[0087] The step shown in the fifth row from the top does not have to be performed. In this case, as in the light-emitting device 1I shown in Fig. 15, the wavelength conversion section 40 fabricated in the step shown in the fourth row from the top in Fig. 14 is turned upside down and placed on the light-emitting element 30 and the light-shielding member 50. At this time, alignment is performed so that the second phosphor section 42 is placed on the light-shielding member 50. The wavelength conversion section 40 can be fixed onto the light-emitting element 30 and the light-shielding member 50 via a light-transmitting bonding member such as resin, for example.

[0088] In the light emitting device 1I, the unseparated first phosphor section 41 is disposed on the lower surface side of the wavelength conversion section 40. This allows the light from the first phosphor section 41 to be uniformly incident on the second phosphor section 42, thereby improving the output of infrared light.

[0089] Fig. 16 is a partial cross-sectional view showing a second modified example of the process for producing a wavelength conversion unit. The wavelength conversion unit 40 may be produced by the procedure shown in Fig. 16. First, as shown in the upper part, a member processed into a sheet shape of a predetermined size is placed as the first phosphor unit 41 on the light-emitting element 30 and the light-shielding member 50 arranged on the upper surface 10a of the substrate 10, and then grooves 41x are formed.

[0090] Specifically, for example, a sheet-shaped member having a predetermined size is prepared as the first phosphor portion 41 and placed on the light-emitting element 30 and the light-shielding member 50. The first phosphor portion 41 may be fixed to the light-emitting element 30 and the light-shielding member 50 via a translucent bonding material such as resin, or may be fixed without a bonding material by utilizing the tackiness of the first phosphor portion 41. Instead of placing a sheet-shaped member, the first phosphor portion 41 may be applied to the light-emitting element 30 and the light-shielding member 50 by spraying or the like. Alternatively, the first phosphor portion 41 may be formed by injection molding using a mold or the like, transfer molding, compression molding, or the like. The grooves 41x can be formed by irradiating a laser beam, as described above. In the example of FIG. 16, the grooves 41x are formed so as not to reach the light-shielding member 50.

[0091] Next, as shown in the lower part, the second phosphor section 42 is placed in the groove 41x. The method for placing the second phosphor section 42 is as described above. If necessary, the upper surface of the wavelength conversion section 40 may be polished and flattened. By this process, an unseparated first phosphor section 41 is placed on the lower surface of the wavelength conversion section 40, similar to the light emitting device 1I shown in FIG. 15. This allows light from the first phosphor section 41 to be uniformly incident on the second phosphor section 42, thereby improving the output of infrared light.

[0092] 17 is a partial cross-sectional view showing a third modification of the process for fabricating a wavelength conversion unit. As shown in Fig. 17, the grooves 41x may penetrate the first phosphor unit 41 and reach the light-shielding member 50. In this structure, the contact area between the second phosphor unit 42 and the light-shielding member 50 is increased compared to the structure shown in Fig. 4, and therefore, the adhesion between the second phosphor unit 42 and the light-shielding member 50 can be improved.

[0093] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0094] In addition to the above-described embodiments, the following supplementary notes are also disclosed. (Appendix 1) a plurality of light emitting elements that can be driven individually or in groups; a wavelength converting unit disposed above the plurality of light emitting elements, The wavelength converting unit is a plurality of first phosphor portions disposed above the plurality of light-emitting elements, respectively; a second phosphor portion disposed between adjacent first phosphor portions and including an infrared phosphor. (Appendix 2) 2. The light-emitting device according to claim 1, further comprising a light-shielding member disposed between adjacent light-emitting elements and containing a light-reflective material. (Appendix 3) a third phosphor portion disposed between adjacent light emitting elements and including an infrared phosphor; the infrared phosphor included in the third phosphor portion is a phosphor having a higher excitation intensity at a peak wavelength of light emitted by the light emitting element than an excitation intensity at a peak wavelength of light emitted by the phosphor included in the first phosphor portion, The light emitting device described in Appendix 1, wherein the infrared phosphor contained in the second phosphor section is a phosphor having a higher excitation intensity at the peak wavelength of light emitted by the phosphor contained in the first phosphor section than at the peak wavelength of light emitted by the light emitting element. (Appendix 4) 4. The light emitting device according to claim 1, wherein the infrared phosphor has an emission peak wavelength of 850 nm or more and 1100 nm or less. (Appendix 5) the width of the second phosphor portion is 3 μm or more and 80 μm or less; 5. The light emitting device according to claim 1, wherein the infrared phosphor is a quantum dot phosphor having an average particle size of 50 nm or less. (Appendix 6) 6. The light emitting device according to claim 5, wherein the infrared phosphor is a quantum dot phosphor containing at least one of Ag and Cu, and at least one of Se and S. (Appendix 7) the upper surface of the second phosphor portion has a convex shape; 7. The light emitting device according to claim 1, wherein an apex of the convex shape is higher in a height direction than an upper surface of the first phosphor element. (Appendix 8) 8. The light emitting device according to claim 1, further comprising a convex lens disposed above the first phosphor portion. (Appendix 9) further comprising a flat light-transmitting plate having an upper surface and a lower surface; the light-transmitting plate has, on the lower surface thereof, a plurality of recesses and flat portions located between adjacent recesses; 8. The light emitting device according to claim 1, wherein the recesses are disposed above the first phosphor portions, and the flat portion is disposed above the second phosphor portions. (Appendix 10) 10. The light emitting device according to any one of claims 1 to 9, having, in a top view, between adjacent light emitting elements, an area in which the second phosphor section is arranged and an area in which the second phosphor section is not arranged. (Appendix 11) In one cross section, the first phosphor portion has a trapezoidal shape with a lower surface width greater than an upper surface width, 11. The light emitting device according to any one of claims 1 to 10, wherein the second phosphor element has a trapezoidal shape with a width of a lower surface smaller than a width of an upper surface. [Explanation of symbols]

[0095] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I Light-emitting device 10 Substrate 10a Top 10r Element mounting area 11 1st terminal 12 Wiring section 20 Package substrate 20a top surface 20r Substrate placement area 22 2nd terminal 30 Light-emitting element 35 electrodes 40 Wavelength conversion unit 41 First phosphor section 41x,42x groove 42 Second phosphor section 50 Light blocking material 60 Convex Lens 70 Translucent plate 71 Recess 72 Flat area 80 Third Phosphor Section 91 Anti-reflective coating 92 DBR membrane 110 Wire 120 Covering material

Claims

1. a plurality of light emitting elements that can be driven individually or in groups; a wavelength converting unit disposed above the plurality of light emitting elements, The wavelength converting portion is a plurality of first phosphor portions disposed above the plurality of light-emitting elements, respectively; a second phosphor portion disposed between adjacent first phosphor portions and including an infrared phosphor.

2. The light emitting device according to claim 1 , further comprising a light blocking member disposed between adjacent light emitting elements and including a light reflective material.

3. a third phosphor portion disposed between adjacent light emitting elements and including an infrared phosphor; the infrared phosphor included in the third phosphor portion is a phosphor having a higher excitation intensity at a peak wavelength of light emitted by the light emitting element than an excitation intensity at a peak wavelength of light emitted by the phosphor included in the first phosphor portion, 2. The light emitting device according to claim 1, wherein the infrared phosphor contained in the second phosphor portion is a phosphor having an excitation intensity at the peak wavelength of the light emitted by the phosphor contained in the first phosphor portion that is higher than the excitation intensity at the peak wavelength of the light emitted by the light emitting element.

4. The light emitting device according to claim 1 , wherein the infrared phosphor has an emission peak wavelength of 850 nm or more and 1100 nm or less.

5. the width of the second phosphor portion is 3 μm or more and 80 μm or less; The light emitting device according to claim 1 , wherein the infrared phosphor is a quantum dot phosphor having an average particle size of 50 nm or less.

6. The light emitting device according to claim 5 , wherein the infrared phosphor is a quantum dot phosphor containing at least one of Ag and Cu, and at least one of Se and S.

7. the upper surface of the second phosphor portion has a convex shape; The light emitting device according to claim 1 , wherein an apex of the convex shape is higher in a height direction than an upper surface of the first phosphor element.

8. The light emitting device according to claim 1 , further comprising a convex lens disposed above the first phosphor portion.

9. further comprising a flat light-transmitting plate having an upper surface and a lower surface; the light-transmitting plate has, on the lower surface thereof, a plurality of recesses and flat portions located between adjacent recesses; The light emitting device according to claim 1 , wherein the recesses are disposed above the first phosphor portions, and the flat portions are disposed above the second phosphor portions.

10. 4. The light emitting device according to claim 1, wherein, when viewed from above, the light emitting device has, between adjacent light emitting elements, an area in which the second phosphor section is arranged and an area in which the second phosphor section is not arranged.

11. In one cross section, the first phosphor portion has a trapezoidal shape in which the width of the lower surface is greater than the width of the upper surface, The light emitting device according to claim 1 , wherein the second phosphor element has a trapezoidal shape with a width of a lower surface smaller than a width of an upper surface.

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