Light emitting device and method for manufacturing light emitting device

Abstract

Disclosed is a light emitting device (1) which comprises: a light emitting element (20); a first covering member (61) that includes, as a base material, a resin that covers the lower surface and / or the side surface of the light emitting element (20); a second covering member (62) that is positioned above the first covering member (61) and composed of an inorganic material; and granular members (70) that are disposed between the first covering member (61) and the second covering member (62). The granular members (70) include inorganic particles (75) that are in contact with both the first covering member (61) and the second covering member (62).

Description

Light emitting device and method for manufacturing the same

[0001] The present disclosure relates to a light emitting device and a method for manufacturing a light emitting device.

[0002] Light emitting devices having multiple covering members are known. For example, Patent Document 1 discloses a light emitting device including a semiconductor chip, a phosphor layer onto which light emitted from the semiconductor chip is incident, a resin layer surrounding the semiconductor chip, and an insulating member covering the phosphor layer and the resin layer, in which the resin layer and the insulating member are made of different materials.

[0003] JP 2017-55038 A

[0004] The present disclosure aims to improve adhesion between cover members in a light emitting device having a plurality of cover members.

[0005] A light emitting device according to one embodiment of the present disclosure includes a light emitting element, a first coating member having a resin base material that covers the bottom and / or side surfaces of the light emitting element, a second coating member that is positioned above the first coating member and is made of an inorganic material, and a granular member that is disposed between the first coating member and the second coating member, wherein the granular member contains inorganic particles that are in contact with both the first coating member and the second coating member.

[0006] According to an embodiment of the present disclosure, in a light emitting device having a plurality of covering members, the adhesion between the covering members can be improved.

[0007] FIG. 2 is a top view schematically showing the light emitting device according to the first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a partial cross-sectional view schematically showing the vicinity of the interface between the first covering member and the second covering member shown in FIG. 2. FIG. 4 is a cross-sectional view (part 4) illustrating a manufacturing process of the light emitting device according to the first embodiment. FIG. 5 is a cross-sectional view (part 6) illustrating a manufacturing process of the light emitting device according to the first embodiment. FIG. 6 is a cross-sectional view (part 7) illustrating a manufacturing process of the light emitting device according to the first embodiment. FIG. 8 is a cross-sectional view (part 8) illustrating a manufacturing process of the light emitting device according to the first embodiment. FIG. 9 is a cross-sectional view (part 1) illustrating a manufacturing process of the light emitting device according to the first embodiment. FIG. 10 is a cross-sectional view (part 3) illustrating a manufacturing process of a light-emitting device according to Modification 1 of the first embodiment. FIG. 11 is a cross-sectional view (part 4) illustrating a manufacturing process of a light-emitting device according to Modification 1 of the first embodiment. FIG. 12 is a cross-sectional view (part 5) illustrating a manufacturing process of a light-emitting device according to Modification 1 of the first embodiment. FIG. 13 is a cross-sectional view (part 6) illustrating a manufacturing process of a light-emitting device according to Modification 1 of the first embodiment. FIG. 14 is a cross-sectional view (part 7) illustrating a manufacturing process of a light-emitting device according to Modification 1 of the first embodiment. FIG. 15 is a cross-sectional view schematically illustrating a light-emitting device according to a second embodiment.

[0008] Hereinafter, an embodiment of the invention will be described 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 invention. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or components.

[0009] Furthermore, the embodiments shown below are intended to exemplify light-emitting devices and the like embodying the technical concepts of the present invention, and are not intended to limit the present invention thereto. 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 invention. Furthermore, the content described in one embodiment may also be applicable 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] First Embodiment (Light Emitting Device 1) Fig. 1 is a top view schematically showing a light emitting device according to a first embodiment, and Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1 .

[0011] 1 and 2 , the light emitting device 1 includes a wiring substrate 10, a light emitting element 20, a protective element 30, a light guide member 40, a light-transmitting member 50, a first covering member 61, a second covering member 62, and a granular member 70. The first covering member 61 covers the lower surface 20b and / or the side surface 20c of the light emitting element 20. The first covering member 61 has a resin as its base material. The second covering member 62 is located above the first covering member 61 and is made of an inorganic material. The granular member 70 is disposed between the first covering member 61 and the second covering member 62. The granular member 70 includes inorganic particles that contact both the first covering member 61 and the second covering member 62.

[0012] When the first coating member 61 and the second coating member 62 are made of different materials, such as when the base material of the first coating member 61 is a resin and the second coating member is made of an inorganic material, it may be difficult to obtain sufficient adhesion depending on the combination of materials. Therefore, in the light emitting device 1, the granular member 70 contains inorganic particles 75 that contact both the first coating member 61 and the second coating member 62, and therefore the anchor effect of the granular member 70 can improve the adhesion between the first coating member 61 and the second coating member 62.

[0013] 1 and 2 , the light emitting device 1 has a configuration including a wiring substrate 10, a protective element 30, a light guiding member 40, and a light-transmitting member 50. However, the configuration is not limited to this, and the light emitting device 1 may have a configuration that does not include one or more of the wiring substrate 10, the protective element 30, the light guiding member 40, and the light-transmitting member 50.

[0014] In the light emitting device 1, the light emitting element 20 is disposed on the wiring substrate 10. The light emitting element 20 has an upper surface 20a, a lower surface 20b opposite the upper surface 20a, and a plurality of side surfaces 20c continuous with the upper surface 20a and the lower surface 20b. In the light emitting element 20, light is emitted from the upper surface 20a and the side surfaces 20c. Light may also be emitted from the lower surface 20b of the light emitting element 20, or an insulating reflective film (e.g., a dielectric multilayer film) may be disposed on the lower surface 20b of the light emitting element 20 to prevent light from being emitted from the lower surface 20b. Furthermore, in the light emitting device 1, a protective element 30 may be disposed on the wiring substrate 10.

[0015] The light-guiding member 40 may cover a portion of the side surface 20c of each of the light-emitting elements 20, or may cover substantially the entirety of the side surface 20c of each of the light-emitting elements 20. In the example shown in Fig. 2, the light-guiding member 40 covers at least a portion of the upper end side (i.e., the side continuous with the upper surface 20a) of the light-emitting element 20. The light-guiding member 40 may or may not cover the upper surface 20a of the light-emitting element 20.

[0016] The light-transmitting member 50 can be disposed on the light-emitting element 20 and on the light-guiding member 40. The light-transmitting member 50 has an upper surface 50a, a lower surface 50b opposite the upper surface 50a, and a plurality of side surfaces 50c continuous with the upper surface 50a and the lower surface 50b. The upper surface 50a of the light-transmitting member 50 constitutes a part of the upper surface of the light-emitting device 1 as a light extraction surface of the light-emitting device 1. The outer peripheral region of the lower surface 50b of the light-transmitting member 50 is covered by the light-guiding member 40. In the example shown in FIG. 2 , the area of ​​the lower surface 50b of the light-transmitting member 50 is larger than the area of ​​the upper surface 20a of the light-emitting element 20. In this case, the light-guiding member 40 can cover the area of ​​the lower surface 50b of the light-transmitting member 50 that does not face the upper surface 20a of the light-emitting element 20.

[0017] The first covering member 61 covers the bottom surface 20b and / or the side surface 20c of the light-emitting element 20. That is, the first covering member 61 may cover only the bottom surface 20b of the light-emitting element 20, only the side surface 20c, or both the bottom surface 20b and the side surface 20c. The first covering member 61 may directly cover the bottom surface 20b and / or the side surface 20c of the light-emitting element 20, or may cover them via a gap or another member. The first covering member 61 may cover part or all of the side surface 50c of the light-transmitting member 50, or may not cover it at all. In the example shown in FIG. 2 , the first covering member 61 is disposed on the wiring substrate 10 and directly covers the bottom surface 20b and the side surface 20c of the light-emitting element 20. In the example shown in FIG. 2 , the first covering member 61 includes a portion that directly covers the side surface 20c of the light-emitting element 20 and a portion that covers it via the light-guiding member 40. Furthermore, in an area of ​​the lower surface 50b of the light-transmitting member 50 that does not face the upper surface 20a of the light-emitting element 20, the first covering member 61 covers the lower surface 50b of the light-transmitting member 50 via the light-guiding member 40. The first covering member 61 is made of resin as a base material.

[0018] The second covering member 62 is positioned above the first covering member 61. The second covering member 62 may cover a portion of the side surface 20c of the light-emitting element 20, or may not cover it at all. The second covering member 62 may cover a portion of, all of, or not at all of the side surface 50c of the light-transmitting member 50. In the example shown in FIG. 2 , the second covering member 62 covers the entire side surface 50c of the light-transmitting member 50. The second covering member 62 is made of an inorganic material. It is preferable to select a material with excellent thermal conductivity as the inorganic material constituting the second covering member 62. As a result, by having the second covering member 62 cover the side surface 50c of the light-transmitting member 50, heat from the light-transmitting member 50 can be efficiently dissipated toward the wiring substrate 10. The second covering member 62 does not have to be disposed in contact with the wiring substrate 10 as shown in FIG. 2 , or may be disposed in contact with the wiring substrate 10 outside the first covering member 61.

[0019] The granular member 70 is disposed between the first covering member 61 and the second covering member 62. The granular member 70 includes a plurality of inorganic particles 75. The inorganic particles 75 may be primary particles or secondary particles formed by agglomerations of two or more primary particles. A mixture of primary and secondary particles may also be present. The granular member 70 includes inorganic particles 75 that contact both the first covering member 61 and the second covering member 62. When the first covering member 61 covers a portion of the side surface 50c of the light-transmitting member 50 or does not cover the side surface 50c of the light-transmitting member 50 at all, the granular member 70 can be disposed in the portion of the side surface 50c of the light-transmitting member that is not covered by the first covering member 61. Thus, for example, by using a material with excellent thermal conductivity as the inorganic particles 75, heat generated in the light-transmitting member 50 can be efficiently dissipated toward the wiring substrate 10.

[0020] 1 and 2 , a second covering member 62 covers the first covering member 61. The second covering member 62 exposes the upper surface 50a of the light-transmitting member 50 and covers the side surface 50c of the light-transmitting member 50. The second covering member 62 forms part of the outer surface of the light-emitting device 1.

[0021] In the light emitting device 1, when a current is supplied from an external power source to the light emitting element 20, light is emitted from the light emitting element 20. Of the light emitted from the light emitting element 20, light traveling upward (i.e., toward the lower surface 50b of the light-transmitting member 50) is extracted to the outside of the light emitting device 1 via the light-transmitting member 50. Furthermore, of the light emitted from the light emitting element 20, a portion of the light traveling in the horizontal direction is reflected at the interface between the light guiding member 40 and the first covering member 61, and extracted to the outside of the light emitting device 1 via the light guiding member 40 and the light-transmitting member 50. Of the light emitted from the light emitting element 20, another portion of the light traveling in the horizontal direction is reflected at the interface between the light emitting element 20 and the first covering member 61, and extracted to the outside of the light emitting device 1 via the light-transmitting member 50.

[0022] In the light emitting device 1, the granular member 70 contains inorganic particles 75 that contact both the first covering member 61 and the second covering member 62, and therefore the anchor effect of the granular member 70 can improve the adhesion between the first covering member 61 and the second covering member 62. In other words, the inorganic particles 75 act as a link between the first covering member 61 and the second covering member 62, and the contact area between the first covering member 61 and the second covering member 62 can be reduced, thereby improving the adhesion between the first covering member 61 and the second covering member 62.

[0023] FIG. 3 is a partial cross-sectional view schematically illustrating the vicinity of the interface between the first coating member and the second coating member shown in FIG. 2 . As shown in FIG. 3 , the granular member 70 is preferably arranged along the interface 60i between the first coating member 61 and the second coating member 62 and includes a plurality of inorganic particles 75a in contact with both the first coating member 61 and the second coating member 62. This can further improve adhesion between the first coating member 61 and the second coating member 62. Note that "arranged along the interface" does not necessarily mean being arranged in contact with the interface 60i and substantially parallel to the interface 60i, but also includes being spaced apart from the interface 60i and substantially parallel to the interface 60i, as described below. Furthermore, when the plurality of inorganic particles 75 are arranged along the interface 60i, the plurality of inorganic particles 75 may be arranged spaced apart from each other or in contact with each other.

[0024] The granular member 70 preferably further includes a plurality of inorganic particles 75b arranged in the first covering member 61 along the interface 60i between the first covering member 61 and the second covering member 62. That is, the granular member 70 preferably includes a plurality of inorganic particles 75b in the first covering member 61 located below the interface 60i in the vicinity of the interface 60i. This allows the region in which the inorganic particles 75 are distributed to spread in the thickness direction of the first covering member 61 (the vertical direction in FIG. 3 ) along the interface 60i, thereby enabling heat generated in the light-emitting element 20 and / or the light-transmitting member 50 to be efficiently dissipated.

[0025] Each component included in the light emitting device 1 will be described in detail below.

[0026] (Wiring Board 10) The wiring board 10 is a component on which the light-emitting elements 20 are disposed. The wiring board 10 includes wiring for supplying power to the light-emitting elements 20 from the outside and a substrate 11 supporting the wiring. As an example, the wiring board 10 includes upper surface wiring 12 disposed on the upper surface on which the light-emitting elements 20 are disposed, and lower surface wiring 13 disposed on the lower surface opposite the upper surface. The substrate 11 has, for example, a substantially rectangular parallelepiped or cubic shape. The substrate 11 is preferably made of an insulating material that is not easily transmitted by light emitted from the light-emitting elements 20 or external light. Examples of materials for the substrate 11 include ceramics such as aluminum oxide, aluminum nitride, silicon nitride, and mullite; resins such as epoxy resin, silicone resin, modified epoxy resin, urethane resin, phenolic resin, polyimide resin, BT resin, and polyphthalamide; semiconductors such as silicon; and metals such as copper and aluminum, as well as composites thereof. Among these, ceramics, which have excellent heat dissipation properties, are preferably used as the material for the substrate 11.

[0027] The upper wiring 12 includes wiring electrically connected to the light-emitting element 20 and wiring electrically connected to the protective element 30. The lower wiring 13 includes an external connection terminal electrically connected to an external power supply. The upper wiring 12 and the lower wiring 13 can be made of, for example, metals such as iron, copper, nickel, aluminum, gold, silver, platinum, titanium, tungsten, and palladium, or alloys containing at least one of these metals. Furthermore, the wiring substrate 10 may include relay wiring inside and / or on the side of the base material 11 for connecting the upper wiring 12 and the lower wiring 13.

[0028] The wiring substrate 10 does not need to have the bottom surface wiring 13. In this case, an external connection terminal can be disposed on the top surface of the base material 11 at an end of the top surface wiring 12 opposite to the end electrically connected to the light emitting element 20.

[0029] The upper surface of the wiring substrate 10 may be flat or may include a recess. The light emitting device 1 may have a structure in which the light emitting element 20 is disposed on the bottom surface of the wiring substrate 10 that defines the recess.

[0030] (Light-emitting element 20) A semiconductor light-emitting element such as a light-emitting diode (LED) chip or a semiconductor laser (LD) chip can be suitably used as the light-emitting element 20. The shape, size, etc. of the light-emitting element 20 can be selected arbitrarily. In the example shown in FIG. 2 , the light-emitting element 20 has a plurality of electrodes 25 on its lower surface 20b. The light-emitting element 20 is disposed on the wiring substrate 10. The light-emitting element 20 is flip-chip mounted on the wiring substrate 10 with the lower surface 20b having the electrodes 25 facing the wiring substrate 10. The plurality of electrodes 25 of the light-emitting element 20 are electrically connected to the upper surface wiring 12. The plurality of electrodes 25 of the light-emitting element 20 and the upper surface wiring 12 can be connected using known members such as eutectic solder, conductive paste, or bumps.

[0031] The light-emitting element 20 includes, for example, a semiconductor structure and a support substrate that supports the semiconductor structure. The semiconductor structure includes an n-side semiconductor layer, a p-side semiconductor layer, and a light-emitting layer sandwiched between the n-side semiconductor layer and the p-side semiconductor layer. The light-emitting layer may have a single quantum well (SQW) structure or a multiple quantum well (MQW) structure including multiple well layers. The semiconductor structure includes multiple semiconductor layers made of nitride semiconductors. The nitride semiconductors include In ｘ Al ｙ Ga １－ｘ－ｙ The term "light-emitting layer" includes semiconductors of all compositions in which the composition ratios x and y in the chemical formula N (0≦x, 0≦y, x+y≦1) are varied within the respective ranges. The emission peak wavelength of the light-emitting layer can be appropriately selected depending on the purpose. The light-emitting layer is configured to be able to emit, for example, visible light or ultraviolet light.

[0032] The light-emitting element 20 may have one semiconductor structure on one support substrate, or may have multiple semiconductor stacks on one support substrate. Furthermore, one semiconductor structure may have only one light-emitting layer, or may have multiple light-emitting layers. The structure of a semiconductor structure having multiple light-emitting layers may be a structure including multiple light-emitting layers between one n-side semiconductor layer and one p-side semiconductor layer, or a structure including an n-side semiconductor layer, a light-emitting layer, and a p-side semiconductor layer in that order, repeated multiple times.

[0033] In the light emitting device 20, a plurality of electrodes 25 are disposed on the semiconductor structure. The electrodes 25 include an n-electrode connected to the n-side semiconductor layer and a p-electrode connected to the p-side semiconductor layer. The p-electrode and the n-electrode may be disposed on different surfaces of the semiconductor laminate, or may be disposed on the same surface. In this case, the plurality of electrodes 25 including the p-electrode and the n-electrode are disposed on the same surface of the semiconductor structure, and the side on which the plurality of electrodes 25 are disposed constitutes the lower surface 20b of the light emitting device 20, and the surface of the support substrate opposite to the surface on which the semiconductor structure is disposed constitutes the upper surface 20a of the light emitting device 20. The support substrate may be made of sapphire or spinel (MgAl ２ O ４ Examples of the substrate include an insulating substrate such as a silicon nitride (SiN) or a nitride-based semiconductor substrate such as gallium nitride. In order to extract light emitted from the light-emitting layer through the support substrate, it is preferable that the support substrate be made of a light-transmitting material. The light-emitting element 20 does not necessarily have to include a support substrate.

[0034] (Protective element 30) The light emitting device 1 can include a protective element 30. The protective element 30 is a component for improving electrostatic breakdown voltage. The protective element 30 is, for example, a Zener diode. The protective element 30 is disposed on the wiring substrate 10. When the first covering member 61 is made of a material having better insulating properties than the second covering member 62, it is preferable that the protective element 30 be covered by the first covering member 61.

[0035] (Light-guiding member 40) The light-guiding member 40 is a member that guides light emitted from the light-emitting element 20 to the light-transmitting member 50. By having the light-guiding member 40 cover the side surface of the light-emitting element 20, it becomes easier to guide the light emitted from the side surface of the light-emitting element 20 to the light-transmitting member 50, and it is possible to improve the light extraction efficiency of the light-emitting device 1. Furthermore, the light-guiding member 40 can be used as an adhesive member that bonds the light-emitting element 20 and the light-transmitting member 50 together.

[0036] In the example shown in FIG. 2 , the light-guiding member 40 is arranged so as to cover each side surface 20 c of the light-emitting element 20. The light-guiding member 40 may or may not be arranged so as to cover the upper surface 20 a of the light-emitting element 20. For example, a light-transmitting resin can be used as the light-guiding member 40. Examples of the light-transmitting resin include thermosetting resins such as epoxy resin, modified epoxy resin, silicone resin, and modified silicone resin. Among them, silicone resin, which has high heat resistance, is preferably used. The light-guiding member 40 may contain at least one of a light-diffusing material and a phosphor, which will be described later, or may contain neither a light-diffusing material nor a phosphor.

[0037] (Light-transmitting member 50) The light-transmitting member 50 is a member disposed on the light-emitting element 20, which transmits light emitted from the light-emitting element 20 and releases it to the outside. The light-transmitting member 50 may transmit 60% or more of the light from the light-emitting element 20 and / or light obtained by wavelength conversion of the light from the light-emitting element 20 (for example, light having a peak wavelength in the range of 320 nm to 850 nm), and preferably transmits 70% or more of the light.

[0038] The light-transmitting member 50 can contain a wavelength converting material that can convert the wavelength of at least a portion of the incident light, which facilitates chromaticity adjustment of the light-emitting device 1. The light-transmitting member 50 may contain one type of wavelength converting material or multiple types of wavelength converting materials.

[0039] The light-transmitting member 50 may be made of a wavelength converting material and a base material, or may be made of only the wavelength converting material.

[0040] When the light-transmitting member 50 is composed of a wavelength converting material and a base material, the wavelength converting material may be contained in the base material or may be disposed on the surface of the base material. When the wavelength converting material is disposed on the surface of the base material, the wavelength converting material can be disposed on the surface of the base material that faces the light-emitting element 20. Furthermore, only the wavelength converting material may be disposed on the surface of the base material, or a resin containing the wavelength converting material may be disposed.

[0041] When the wavelength converting material is contained in a base material, the wavelength converting material may be dispersed or unevenly distributed in the base material.

[0042] Examples of materials for the base material include inorganic materials such as glass, ceramic, and sapphire, and organic materials such as resins or hybrid resins containing one or more of silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, phenolic resin, and fluororesin.

[0043] The light-transmitting member 50 may contain a light diffusing material depending on the purpose.

[0044] Known phosphors can be used as the wavelength conversion material. The phosphors include yttrium aluminum garnet phosphors (e.g., (Y, Gd) ３ (Al, Ga) ５ O １２ :Ce), lutetium aluminum garnet phosphors (e.g., Lu ３ (Al, Ga) ５ O １２ :Ce), terbium aluminum garnet phosphors (e.g., Tb ３ (Al, Ga) ５ O １２ :Ce), CCA-based phosphors (e.g., Ca １０ (P.O. ４ ) ６ Cl ２ :Eu), SAE-based phosphors (e.g., Sr ４ Al １４ O ２５ :Eu), chlorosilicate phosphors (e.g., Ca ８ MgSi ４ O １６ Cl ２ :Eu), silicate-based phosphors (e.g., (Ba, Sr, Ca, Mg) ２ SiO ４ :Eu), β-sialon-based phosphors (e.g., (Si, Al) ３ (O, N) ４ :Eu) or α-sialon-based phosphor (e.g., Ca(Si,Al) １２ (O, N) １６ oxynitride phosphors such as (La,Y) ３ Si ６ N １１:Ce), BSESN-based phosphors (e.g., (Ba, Sr) ２ Si ５ N ８ :Eu), SLA-based phosphors (e.g., SrLiAl ３ N ４ :Eu), CASN-based phosphors (e.g., CaAlSiN ３ :Eu) or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN ３ nitride-based phosphors such as KSF-based phosphors (e.g., K ２ SiF ６ :Mn), KSAF-based phosphors (e.g., K ２ (Si １－ｘ Al ｘ ) F ６－ｘ :Mn where x satisfies 0<x<1) or MGF-based phosphor (for example, 3.5MgO.0.5MgF ２ GeO ２ Fluoride-based phosphors such as (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I) and quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I) ３ Here, FA and MA represent formamidinium and methylammonium, respectively.), II-VI quantum dots (e.g., CdSe), III-V quantum dots (e.g., InP), or quantum dots with a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se) ２ ) etc. can be used.

[0045] As the light diffusing material, any material known in the art can be used, such as titanium oxide, silicon oxide, aluminum oxide, barium titanate, etc.

[0046] (First covering member 61) The first covering member 61 can be, for example, a light-reflective member including a first light-reflecting material. The first light-reflecting material is preferably a material that can suitably reflect light emitted from the light-emitting element 20. The first covering member 61 preferably has a reflectance of 60% or more with respect to light emitted from the light-emitting element 20, and more preferably has a reflectance of 70% or more, 80% or more, or 90% or more.

[0047] The first covering member 61 is preferably made of an insulating material. The first covering member 61 is, for example, a member obtained by impregnating a first light-reflecting material into a translucent resin. The first covering member 61 can reflect light from the light-emitting element 20 by utilizing the difference in refractive index between the first light-reflecting material and the translucent resin. Examples of resins used for the first covering member 61 include resins or hybrid resins containing one or more of silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, acrylic resin, phenolic resin, bismaleimide triazine resin, and polyphthalamide resin. Among these, it is particularly preferable to use silicone resin, which has excellent light resistance, heat resistance, electrical insulation, and flexibility.

[0048] Examples of the first light-reflecting material include titanium oxide, silicon oxide, aluminum oxide, zirconium oxide, magnesium oxide, potassium titanate, barium titanate, zinc oxide, silicon nitride, aluminum nitride, boron nitride, calcium carbonate, calcium hydroxide, calcium silicate, and combinations thereof. Among these, from the viewpoint of light reflection, it is preferable to use titanium oxide, which has a relatively high refractive index.

[0049] The first covering member 61 can be made of a material with better insulating properties than the second covering member 62 described below. In this case, the first covering member 61 preferably covers the upper surface wiring 12 of the wiring substrate 10. This results in a structure in which the upper surface wiring 12 of the wiring substrate 10 is covered by the first covering member 61 and separated from the second covering member 62. This ensures insulation between the light-emitting element 20 and the second covering member 62. As a result, for example, the occurrence of leakage current can be reduced. Furthermore, the first covering member 61 preferably covers the electrode 25 of the light-emitting element 20 on the lower surface 20b of the light-emitting element 20. This reduces the occurrence of leakage current compared to when the electrode 25 of the light-emitting element 20 is covered by the second covering member 62.

[0050] The first covering member 61 can be made of a material having a higher reflectance for light emitted from the light emitting element 20 than the second covering member 62 described below. In this case, the first covering member 61 preferably covers the side surface 20c of the light emitting element 20. This allows more of the light emitted from the light emitting element 20 that travels laterally to be reflected toward the light guide member 40 and the light-transmitting member 50.

[0051] (Second coating member 62) The second coating member 62 may be a light-reflective member containing, for example, a second light-reflecting material, silicon oxide, and an alkali metal. The second coating member 62 may be obtained by, for example, curing a mixture of powder of the second light-reflecting material, powder of silicon oxide, and an alkaline solution.

[0052] The second light-reflecting material is, for example, plate-shaped (including scale-shaped) particles. Specifically, the second light-reflecting material is, for example, boron nitride or aluminum oxide. These materials can reflect light of the peak wavelength from the light-emitting element 20.

[0053] The second light-reflecting material may be a primary particle or a secondary particle formed by an aggregation of two or more primary particles. A mixture of primary particles and secondary particles may also be used. The average particle size of the second light-reflecting material is, for example, 0.6 μm or more and 43 μm or less. The particle size of the second light-reflecting material can be calculated using, for example, a scanning electron microscope "TM3030Plus" manufactured by Hitachi High-Technologies Corporation.

[0054] The weight ratio of silicon oxide to the second light-reflecting material contained in the second coating member 62 is, for example, 1:4 or more and 1:1 or less. That is, the weight of the second light-reflecting material contained in the second coating member 62 is, for example, 1 to 4 times the weight of the silicon oxide contained in the second coating member 62. Within this range, shrinkage of the mixture during curing can be reduced. If the amount of the second light-reflecting material is too large, there is a risk of reduced curability. On the other hand, if the amount of silicon oxide is too large, shrinkage due to curing increases, and cracks may occur during curing.

[0055] The average particle size of the silicon oxide is, for example, 0.1 μm to 10 μm, inclusive. Within this range, the density per volume of the raw materials (second light-reflecting material and silicon oxide) can be improved, thereby ensuring the strength of second covering member 62.

[0056] The average particle size of the silicon oxide powder is preferably smaller than the average particle size of the second light-reflecting material. This allows the silicon oxide powder to fill gaps that form between the second light-reflecting materials during mixing. The average particle size of the silicon oxide powder can be calculated by measuring the particle size distribution of the silicon oxide powder using laser diffraction. The average particle size of the silicon oxide is a value measured before mixing with the alkaline solution. Because the silicon oxide powder melts when mixed with the alkaline solution, it is difficult to confirm the particle size from the second coating member 62. Note that the content ratio of silicon oxide to the second light-reflecting material from the second coating member 62 may be calculated, for example, by observing a cross-section of the second coating member 62 extracted using an SEM and based on the occupancy rate of silicon oxide and the second light-reflecting material.

[0057] The alkali metal is the alkali metal contained in the alkaline solution, for example, potassium and / or sodium.

[0058] The second light-reflecting material functions as an aggregate of the second covering member 62 when the second covering member 62 is heated by heat generated from the light-emitting element 20. This suppresses shrinkage of the second covering member 62 due to the heat of the light-emitting element 20, making it possible to obtain a light-emitting device 1 with high heat resistance. Such a light-emitting device 1 has a long service life. Furthermore, the second covering member 62 can reflect light from the light-emitting element 20 by utilizing the difference in refractive index between the second light-reflecting material and silicon oxide.

[0059] Furthermore, by obtaining the second covering member 62 in this way, which is suppressed from shrinking due to the heat of the light emitting element 20, it becomes possible to use the light emitting device 1 even under conditions in which a large amount of heat is generated from the light emitting element 20 (for example, when a large amount of power is supplied to the light emitting element 20). By being able to increase the amount of power supplied to the light emitting element 20, the amount of light emitted by the light emitting device can be increased.

[0060] The linear thermal expansion coefficient of the second covering member 62 is preferably 0.05 ppm / °C or more and 5 ppm / °C or less in the temperature range of 40°C or more and 300°C or less. This makes it possible to reduce the expansion of the second covering member 62 and improve reliability even if the temperature of the second covering member 62 rises when the light emitting device 1 is used. The linear thermal expansion coefficient of the second covering member 62 can be, for example, about 1 ppm.

[0061] Furthermore, the second covering member 62 preferably contains a light scattering material, such as titanium oxide or zirconium oxide.

[0062] The light scattering material may be titanium oxide alone, or titanium oxide whose surface has been subjected to one of various surface treatments such as silicon oxide, aluminum oxide, zirconium oxide, zinc, or organic materials. The light scattering material may be zirconium oxide alone, or zirconium oxide whose surface has been subjected to one of various surface treatments such as silicon oxide, aluminum oxide, zinc, or organic materials. Stabilized zirconium oxide to which calcium, magnesium, yttrium, aluminum, or the like has been added, or partially stabilized zirconium oxide, may also be used.

[0063] When a light scattering material is added to the second covering member 62, the light scattering material is dispersed in the silicon oxide. The average particle size of the light scattering material is preferably smaller than the average particle size of the second light reflecting material. This allows the light scattering material to be disposed in the gaps between the second light reflecting materials, making it difficult for light emitted from the light emitting element 20 to be emitted to the outside of the light emitting device 1 through the gaps between the second light reflecting materials. As a result, the parting at the light extraction surface of the light emitting device 1 is improved. The average particle size of the light scattering material is measured by laser diffraction.

[0064] (Granular member 70) The inorganic particles 75 contained in the granular member 70 can be made of a material with excellent thermal conductivity. For example, oxides, nitrides, and silicates can be used. Examples of oxides include titanium oxide, magnesium oxide, zirconium oxide, zinc oxide, silicon oxide, and aluminum oxide. Examples of nitrides include boron nitride. Examples of silicates include wollastonite and potassium silicate. These can be used alone or in combination of two or more. The inorganic particles can be particles that do not contain organic materials, or particles that contain organic materials.

[0065] The shape of the inorganic particles 75 may be spherical or non-spherical. Examples of non-spherical shapes include plate-shaped (including scale-shaped) and needle-shaped. Examples of plate-shaped inorganic particles include boron nitride. Examples of spherical inorganic particles include aluminum oxide. Examples of needle-shaped inorganic particles include wollastonite. Compared to spherical inorganic particles, scale-shaped inorganic particles can reduce the number of inorganic particles that sink into the uncured first coating member 61 when placed on the first coating member 61. As a result, as shown in FIG. 3 , multiple inorganic particles 75a are arranged along the interface 60i between the first coating member 61 and the second coating member 62 and are in contact with both the first coating member 61 and the second coating member 62. Furthermore, due to some of the inorganic particles sinking into the first coating member 61, multiple inorganic particles 75b are arranged within the first coating member 61 located below the interface 60i. As a result, both adhesion and heat dissipation effects can be achieved.

[0066] The inorganic particles 75 may have an average particle size of 0.5 μm or more and approximately 45 μm. The inorganic particles 75 contained in the granular component 70 may have a substantially uniform average particle size, or particles of different average particle sizes may be mixed. The average particle size of the inorganic particles 75 may be measured using a scanning electron microscope "TM3030Plus" manufactured by Hitachi High-Technologies Corporation.

[0067] The presence of even one inorganic particle 75 in contact with both the first coating member 61 and the second coating member 62 can have the effect of improving the adhesion between them. However, it is preferable that the coverage of the inorganic particles 75 with respect to the interface between the first coating member 61 and the second coating member 62 be a certain level or higher. Specifically, the coverage of the inorganic particles 75 with respect to the interface between the first coating member 61 and the second coating member 62 is preferably 5% or higher, and more preferably 30% or higher. This can further improve the adhesion between the first coating member 61 and the second coating member 62. The coverage can be calculated using the following formula. First, a scanning electron microscope is used to observe cross sections of the first coating member 61, the inorganic particles 75, and the second coating member 62. The length (L1) of the interface between the first coating member 61 and the inorganic particles 75a and the second coating member 62, and the length (L2) of the portion of the inorganic particles 75 exposed from the first coating member 61 at the interface between the first coating member 61 and the inorganic particles 75a and the second coating member 62 are measured. Next, the coverage (%) is calculated using the following formula (X).

[0068] (L2 / L1)×100 (X) When the above-described calculation method is used, the coverage rate in the example shown in Fig. 3 is 39.5%. Note that the coverage rate may be calculated from observation of the entire interface, or may be calculated from observation of an arbitrary region of the interface.

[0069] The inorganic particles 75 arranged on the upper surface of the first covering member 61 may be evenly dispersed or unevenly distributed. When the inorganic particles 75 are unevenly distributed, for example, it is preferable to distribute the inorganic particles 75 unevenly toward the light-emitting element 20 on the upper surface of the first covering member 61. This allows heat generated by the light-emitting element 20 and / or the light-transmitting member 50 to be dissipated more efficiently toward the wiring substrate 10.

[0070] The interface between the first covering member 61 and the second covering member 62 preferably has an inclined surface that is inclined with respect to the upper surface 20a of the light-emitting element 20. This allows a larger amount of inorganic particles 75 to be arranged at the interface compared to when the interface between the first covering member 61 and the second covering member 62 is parallel to the upper surface 20a of the light-emitting element 20 in a cross-sectional view, thereby improving adhesion between the first covering member 61 and the second covering member 62. In a cross-sectional view, the interface between the first covering member 61 and the second covering member 62 may be linear, curved, or stepped. In the example shown in FIG. 2 , the interface between the first covering member 61 and the second covering member 62 slopes downward (toward the wiring substrate 10) with increasing distance from the outer edge of the upper surface 20a of the light-emitting element 20. In other words, the thickness of the first covering member 61 at the portion in contact with the second covering member 62 is thickest on the side closest to the light-emitting element 20 and becomes thinner with increasing distance from the light-emitting element 20. As a result, the granular member 70 is closer to the wiring board 10 at positions where the first covering member 61 is thin, so that heat generated in the light-emitting element 20 and / or the translucent member 50 when the light-emitting device 1 is in use can be efficiently dissipated to the wiring board 10 via the granular member 70.

[0071] <Method for manufacturing light-emitting device according to the first embodiment> The method for manufacturing the light-emitting device according to the first embodiment includes the steps of preparing a light-emitting element having a bottom surface, a top surface, and side surfaces, arranging a first coating member having a resin as a base material on the bottom surface and / or side surfaces of the light-emitting element, arranging a granular member on the first coating member, and arranging a second coating member made of an inorganic material on the first coating member and the granular member.

[0072] In the manufacturing method of the light-emitting device according to the first embodiment, the step of placing the first coating member may further include a step of placing an uncured first coating member and curing the uncured first coating member after the step of placing the granular member and before the step of placing the second coating member.

[0073] In the manufacturing method of the light-emitting device of the first embodiment, the method further includes a step of placing a translucent member on the light-emitting element before the step of placing the first covering member, and in the step of placing the second covering member, the second covering member can be placed on the side of the translucent member.

[0074] Hereinafter, each manufacturing step of the method for manufacturing the light emitting device according to the first embodiment will be described with reference to the drawings.

[0075] 4A to 4H are cross-sectional views illustrating the manufacturing process of the light emitting device according to the first embodiment.

[0076] 4A shows a process for preparing a light-emitting element. In this process, a light-emitting element 20 is prepared, which has an upper surface 20a, a lower surface 20b, and a plurality of side surfaces 20c continuous with the upper surface 20a and the lower surface 20b. In the example shown in FIG. 4A, the light-emitting element 20 has a plurality of electrodes 25 on the lower surface 20b. The light-emitting element 20 may be prepared by fabrication or by purchase.

[0077] 4B shows a step of arranging a light-emitting element on a wiring substrate. In this step, a light-emitting element 20 is arranged on the wiring substrate 10. In the example of FIG. 4B , the wiring substrate 10 has a base material 11, upper surface wiring 12, and lower surface wiring 13. The light-emitting element 20 is flip-chip mounted on the wiring substrate 10, for example, with the surface on which each electrode 25 is arranged facing the upper surface wiring 12. If the light-emitting device 1 has a protective element 30, the protective element 30 is arranged on the wiring substrate 10 together with the light-emitting element 20.

[0078] 4B , a plurality of light-emitting elements 20 are arranged on the wiring substrate 10. In the example shown in Fig. 4B , the plurality of light-emitting elements 20 are arranged in one direction. However, this is not limiting, and the plurality of light-emitting elements 20 may be arranged in a matrix or a staggered pattern when viewed from above.

[0079] 4C shows a process of placing a light-transmitting member on a light-emitting element. In the example of FIG. 4C , the light-transmitting member 50 has an upper surface 50a, a lower surface 50b opposite the upper surface 50a, and a plurality of side surfaces 50c continuous with the upper surface 50a and the lower surface 50b. In this process, the light-transmitting member 50 is placed on the upper surface 20a of the light-emitting element 20. At this time, the light-guiding member 40 can be used to bond the light-emitting element 20 and the light-transmitting member 50 together.

[0080] 4B and 4C illustrate an example in which the light-emitting element 20 is disposed on the wiring substrate 10, and then the light-transmitting member 50 is disposed on the upper surface 20a of the light-emitting element 20. However, the present invention is not limited to this, and the light-emitting element 20 with the light-transmitting member 50 disposed thereon can be disposed on the wiring substrate 10 after the light-transmitting member 50 is disposed on the upper surface 20a of the light-emitting element 20.

[0081] 4D shows a process of placing a first covering member made of resin on the side surface of the light-emitting element. In this process, an uncured first covering member 61 made of resin is placed on the wiring substrate 10. At this time, the first covering member 61 covers the bottom surface 20b and the side surface 20c of the light-emitting element 20. The uncured first covering member 61 can be placed on the wiring substrate 10 by, for example, potting, spraying, or printing. In the example shown in FIG. 4D, the top surface of the first covering member 61 placed between adjacent light-emitting elements 20 has a curved surface that is recessed toward the wiring substrate 10.

[0082] 4D , the upper surface of the wiring substrate 10 located between adjacent light-emitting elements 20 is covered with a first covering member 61. However, this is not limiting, and a portion of the upper surface of the wiring substrate 10 located between adjacent light-emitting elements 20 may not be covered with the first covering member 61. In this case, the area on the upper surface of the wiring substrate 10 that is not covered with the first covering member 61 can be covered with a second covering member 62.

[0083] FIG. 4E illustrates a process of disposing granular members on the first coating member 61. In this process, for example, the granular members 70 are sprinkled from above the first coating member 61 to dispose the granular members 70 on the uncured first coating member 61. Because the first coating member 61 is uncured when the granular members 70 are disposed, the inorganic particles 75 of the granular members 70 sink into the first coating member 61. At this time, some inorganic particles 75 are partially submerged in the first coating member 61 (i.e., partially exposed from the first coating member 61). In addition to some inorganic particles 75 partially submerged in the first coating member 61, some inorganic particles 75 may be entirely submerged in the first coating member 61. In the example illustrated in FIG. 3, the inorganic particles 75 entirely submerged in the first coating member 61 are located near the interface 60i side of the first coating member 61. The degree to which the inorganic particles 75 sink depends on the shape and density of the inorganic particles 75, the viscosity of the first coating member 61, and other factors.

[0084] The method of disposing the granular material 70 is not limited to sprinkling the granular material 70 from above the first covering member 61, and the granular material 70 may be disposed by spraying.

[0085] After the granular member 70 is disposed on the first coating member 61, some of the inorganic particles 75 contained in the granular member 70 can be removed by, for example, blowing air. The inorganic particles 75 to be removed here are the inorganic particles 75 that are disposed on top of the inorganic particles 75 and are not in contact with the first coating member 61. By removing the inorganic particles 75 that are not in contact with the first coating member 61, only the inorganic particles 75 that are in contact with the first coating member 61 can be disposed on the first coating member 61. As a result, the inorganic particles 75 are in contact with both the first coating member 61 and the second coating member 62, and therefore, the adhesion between the first coating member 61 and the second coating member 62 can be improved.

[0086] The granular members 70 may be arranged in one step or in two steps. When the granular members 70 are arranged in two steps, the second step can be arranged in areas on the upper surface of the first covering member 61 where the inorganic particles 75 were not arranged in the first step, and / or in areas where the inorganic particles 75 arranged in the first step have completely sunk into the first covering member 61. The granular members 70 may be arranged in three or more steps.

[0087] The granular members 70 may or may not be disposed on the upper surface 50a of the light-transmitting member 50. When the granular members 70 are disposed on the upper surface 50a of the light-transmitting member 50, they can be removed, for example, by air blowing before hardening the first covering member 61 described below or before disposing the second covering member described below.

[0088] After the granular members 70 are placed on the first coating member 61, the uncured first coating member 61 can be cured. The uncured first coating member 61 is cured, for example, at a temperature of 100° C. or higher and 200° C. or lower for 1 hour or higher and 10 hours or lower.

[0089] In addition, it is not limited to placing the granular member 70 on the first coating member 61 and then curing the uncured first coating member 61, but the granular member 70 may also be placed on the first coating member 61 while the first coating member 61 is curing.

[0090] 4F shows a process of placing a second coating member made of an inorganic material on the first coating member and the granular members. In this process, a second coating member 62 made of an inorganic material is placed on the first coating member 61 and the granular members 70. In the example shown in FIG. 4F, the second coating member 62 covers the upper surface 50a and the side surface 50c of the light-transmitting member 50. However, the second coating member 62 does not have to cover the upper surface 50a of the light-transmitting member 50. In this case, the process shown in FIG. 4G, which will be described later, can be omitted.

[0091] The process of FIG. 4F will be described in detail. First, an uncured second coating member 62 is prepared. The uncured second coating member 62 can be produced, for example, by mixing a mixed powder of a second light-reflecting material powder and a silicon oxide powder with an alkaline solution. The mixed powder and the alkaline solution are mixed, for example, until a uniform viscosity is achieved, and then degassed and stirred using a stirring / degassing machine capable of stirring under reduced pressure. Next, the uncured second coating member 62 is placed on the first coating member 61 and the granular member 70, as well as on the upper surface 50a and side surface 50c of the light-transmitting member 50. The uncured second coating member 62 can be placed, for example, by potting, spraying, or printing.

[0092] Thereafter, the uncured second covering member 62 is cured. The process of curing the uncured second covering member 62 may include a provisional curing process of provisionally curing the second covering member 62 at a first temperature T1 and a full curing process of curing the second covering member 62 at a second temperature T2 higher than the first temperature T1. The provisional curing process is performed, for example, at a first temperature T1 of 80°C or higher and 100°C or lower for 10 minutes to 2 hours. The full curing process is performed, for example, at a second temperature T2 of 150°C or higher and 250°C or lower for 10 minutes to 3 hours.

[0093] By carrying out the pre-curing step at a lower temperature than the main curing step before the main curing step in this way, cracks are less likely to occur in the cured second covering member 62. Furthermore, the pre-curing step and the main curing step can be carried out while applying pressure. This can increase the light reflectance of the cured second covering member 62. This is thought to be because the uncured second covering member 62 is pressurized, causing the second light reflecting material inside to harden in a more densely packed state. The pressure applied during the main curing step is, for example, 1 MPa. The pre-curing step may be carried out as needed, or may be omitted.

[0094] Here, an example has been described in which the first coating member 61 is cured first, and then the second coating member 62 is cured. However, this is not limiting, and the first coating member 61 and the second coating member 62 can be cured by heating them at one time. That is, after the granular member 70 is placed on the uncured first coating member 61, the second coating member 62 is placed without applying heat to cure the first coating member 61. Then, the first coating member 61 and the second coating member 62 can be heated and cured simultaneously.

[0095] 4G shows a step of exposing the upper surface of the light-transmitting member 50. In this step, the second covering member 62 covering the upper surface 50a of the light-transmitting member 50 is removed to expose the upper surface 50a of the light-transmitting member 50. Grinding, for example, can be used as a method for removing the second covering member 62 covering the upper surface 50a of the light-transmitting member 50. The upper surfaces of the second covering member 62 and the upper surface 50a of the light-transmitting member 50 can be flush with each other, for example. The upper surface 50a of the light-transmitting member 50 exposed from the second covering member 62 serves as the light extraction surface of the light-emitting device 1.

[0096] 4H shows the singulation step. In this step, the plurality of light emitting elements 20 arranged on the wiring substrate 10 are singulated into individual light emitting elements 20. This allows a plurality of light emitting devices 1 to be obtained. As a method for singulation, cutting with a dicing saw, cutting with laser light, or the like can be used. The singulation is performed at the center position between adjacent light emitting elements 20.

[0097] The steps of placing the light-emitting element on the wiring substrate, placing the light-transmitting member on the light-emitting element, exposing the top surface of the light-transmitting member, and singulating may be performed as needed or may be omitted.

[0098] Furthermore, although the above describes an example of a process for manufacturing a plurality of light emitting devices 1, it is also possible to use a process for manufacturing a single light emitting device 1. In this case, the light emitting device 1 can also be obtained by the same manufacturing method as described above.

[0099] <Modification> FIG. 5 is a cross-sectional view schematically illustrating a light-emitting device according to Modification 1 of the first embodiment. As shown in FIG. 5, the light-emitting device 1A differs from the light-emitting device 1 in that it does not include a wiring substrate 10. Furthermore, the light-emitting device 1A differs from the light-emitting device 1 in the direction of inclination of the interface between the first covering member 61 and the second covering member 62. The interface between the first covering member 61 and the second covering member 62 inclines upward (toward the upper surface 50a of the translucent member 50) with increasing distance from the outer edge of the upper surface 20a of the light-emitting element 20. In other words, the thickness of the first covering member 61 at the portion in contact with the second covering member 62 is thinnest on the side closest to the light-emitting element 20 and increases with increasing distance from the light-emitting element 20. The light-emitting device 1A may include a protective element. The light-emitting device 1A may not include the light-guiding member 40 or the translucent member 50.

[0100] Like the light emitting device 1, the light emitting device 1A has granular members 70 containing inorganic particles 75 that are in contact with both the first covering member 61 and the second covering member 62. Therefore, the light emitting device 1A has the same effects as the light emitting device 1.

[0101] <Method of Manufacturing Light-Emitting Device According to Modification 1 of First Embodiment> FIGS. 6A to 6G are cross-sectional views illustrating the manufacturing process of a light-emitting device according to Modification 1 of the first embodiment.

[0102] First, the step of preparing the light-emitting element shown in Fig. 4A is carried out. That is, a light-emitting element 20 having an upper surface 20a, a lower surface 20b, and a plurality of side surfaces 20c continuous with the upper surface 20a and the lower surface 20b is prepared. In the example shown in Fig. 4A, the light-emitting element 20 has a plurality of electrodes 25 on the lower surface 20b. The light-emitting element 20 may be prepared by fabrication or by purchase.

[0103] 6A shows a process of placing a light-transmitting member on a support body. In this process, first, a support body 300 made of resin, metal, or the like is prepared. Next, a light-transmitting member 50 is prepared. In the example of FIG. 6A , the light-transmitting member 50 has an upper surface 50a, a lower surface 50b opposite the upper surface 50a, and a plurality of side surfaces 50c continuous with the upper surface 50a and the lower surface 50b. Then, the light-transmitting member 50 is placed on the support body 300.

[0104] 6A, a plurality of light-transmitting members 50 are arranged on a support body 300. In the example shown in Fig. 6A, the plurality of light-transmitting members 50 are arranged in one direction. However, this is not limiting, and the plurality of light-transmitting members 50 may be arranged in a matrix or a staggered pattern when viewed from above.

[0105] 6B shows a step of arranging the light-emitting element on the light-transmitting member. In this step, the light-emitting element 20 is arranged on the lower surface 50b of the light-transmitting member 50. The light-emitting element 20 is arranged on the support body 300 with the upper surface 20a facing the lower surface 50b of the light-transmitting member 50. At this time, the light-guiding member 40 can be used to bond the light-emitting element 20 and the light-transmitting member 50.

[0106] 6A and 6B illustrate an example in which the light-transmitting member 50 is disposed on the support body 300, and then the light-emitting element 20 is disposed on the lower surface 50b of the light-transmitting member 50. However, the present invention is not limited to this, and the light-emitting element 20 may be disposed on the support body 300 after the light-transmitting member 50 is disposed on the lower surface 50b of the light-transmitting member 50.

[0107] FIG. 6C illustrates a process of placing a second covering member made of an inorganic material on the support. In this process, a second covering member 62 made of an inorganic material is placed on the support 300. In the example illustrated in FIG. 6C , the second covering member 62 covers the entire side surface 50 c of the light-transmitting member 50. However, the second covering member 62 does not necessarily cover a portion of the side surface 50 c of the light-transmitting member 50. Furthermore, the second covering member 62 may cover a portion of the side surface 20 c of the light-emitting element 20, or may not cover the side surface at all. In the example illustrated in FIG. 6C , the upper surface of the second covering member 62 placed between adjacent light-transmitting members 50 has a curved surface that is recessed toward the support 300. Note that the details of this process can be the same as those in the first embodiment.

[0108] 6C , the upper surface of the support 300 located between adjacent light-transmitting members 50 is covered with the second covering member 62. However, this is not limiting, and a portion of the upper surface of the support 300 located between adjacent light-transmitting members 50 may not be covered with the second covering member 62. In this case, the region on the upper surface of the support 300 that is not covered with the second covering member 62 can be covered with the first covering member 61.

[0109] 6D shows the step of placing a granular member on the second coating member. In this step, a granular member 70 is placed on the uncured second coating member 62. Because the second coating member 62 is uncured when the granular member 70 is placed, the inorganic particles 75 of the granular member 70 sink into the second coating member 62. At this time, some inorganic particles 75 are partially submerged in the second coating member 62 (i.e., partially exposed from the second coating member 62). In addition to some inorganic particles 75 partially submerged in the second coating member 62, some inorganic particles 75 may be completely submerged in the second coating member 62. The method for placing the granular member 70 is as described in the first embodiment. After the granular member 70 is placed on the second coating member 62, the uncured second coating member 62 can be cured.

[0110] 6E shows a process of placing a first coating member made of a resin on the second coating member and the granular members. In this process, an uncured first coating member 61 made of a resin is placed on the cured second coating member 62 and the granular members 70. The method for placing the uncured first coating member 61 is as described in the first embodiment. Then, the uncured first coating member 61 is cured.

[0111] In the example shown in Fig. 6E, the first covering member 61 covers the end surfaces of the electrodes 25 of the light-emitting element 20. However, the first covering member 61 does not have to cover the end surfaces of the electrodes 25. In this case, the step of Fig. 6F described below can be omitted.

[0112] Here, an example has been described in which the second coating member 62 is cured first, followed by the first coating member 61. However, this is not limiting, and the first coating member 61 and the second coating member 62 can be cured by heating them at one time. That is, after the granular member 70 is placed on the uncured second coating member 62, the first coating member 61 is placed without applying heat to cure the second coating member 62. Then, the first coating member 61 and the second coating member 62 can be heated and cured simultaneously.

[0113] 6F shows a step of exposing the end faces of the electrodes of the light-emitting element. In this step, the first covering member 61 covering the end faces of the electrodes 25 of the light-emitting element 20 is removed to expose the end faces of the electrodes 25. Grinding, for example, can be used as a method for removing the first covering member 61 covering the end faces of the electrodes 25. The top surface of the first covering member 61 and the end faces of the electrodes 25 can be flush with each other, for example.

[0114] 6G shows the singulation step. In this step, the plurality of light-emitting elements 20 arranged on the support 300 are singulated into individual light-emitting elements 20, and then the support 300 is removed. This allows a plurality of light-emitting devices 1A to be obtained. The singulation method is as described in the first embodiment. After the support 300 is removed, the plurality of light-emitting elements 20 may be singulated into individual light-emitting elements 20.

[0115] Although the above describes an example of a process for manufacturing a plurality of light emitting devices 1A, it is also possible to use a process for manufacturing a single light emitting device 1A. In this case, the light emitting device 1A can be obtained by the same manufacturing method as described above.

[0116] Second Embodiment Fig. 7 is a cross-sectional view schematically illustrating a light emitting device according to a second embodiment. As shown in Fig. 7, the light emitting device 2 includes a wiring substrate 10, a light emitting element 20, a light guide member 40, a light-transmitting member 50, a first covering member 61, a second covering member 62, and a granular member 70. The light emitting device 2 may include a protective element. The light emitting device 2 may not include the light guide member 40 or the light-transmitting member 50.

[0117] The light emitting device 2 differs from the light emitting device 1 in that the first covering member 61 and the second covering member 62 are disposed on the wiring substrate 10 at a distance from the light emitting element 20, the light guide member 40, and the light-transmitting member 50. In the light emitting device 2, the first covering member 61 and the second covering member 62 are members that cover the wiring substrate 10.

[0118] The first covering member 61 and the second covering member 62 can be arranged, for example, in a ring-like or rectangular shape when viewed from above so as to surround the light-emitting element 20 and the light-transmitting member 50. Because the first covering member 61 and the second covering member 62 are light-reflective, light emitted from the light-emitting element 20 and the light-transmitting member 50 can be reflected by the inner surfaces of the first covering member 61 and the second covering member 62 and efficiently extracted to the outside of the light-emitting device 2.

[0119] Similar to the light emitting device 1, the light emitting device 2 includes granular members 70 containing inorganic particles 75 that are in contact with both the first covering member 61 and the second covering member 62. Therefore, similar to the light emitting device 1, the light emitting device 2 can improve the adhesion between the first covering member 61 and the second covering member.

[0120] In the light-emitting device 2, for example, the light-emitting element 20 emits ultraviolet light. In this case, if the coating member is composed only of a first coating member 61 made of a resin, there is a risk of the first coating member 61 being deteriorated by ultraviolet light. Furthermore, if the coating member is composed only of a second coating member 62 made of an inorganic material, deterioration of the second coating member 62 due to ultraviolet light is reduced. However, if the second coating member 62 has lower insulating properties than the first coating member 61, contact between the second coating member 62 and the wiring substrate 10 may result in leakage current. In contrast, if the coating member is configured as shown in FIG. 7 , in which the second coating member 62 is disposed on top of the first coating member 61, the first coating member 61, which has higher insulating properties than the second coating member 62, is disposed on the wiring substrate 10 side of the coating member, thereby reducing current leakage. Furthermore, since the second coating member 62 is disposed on top of the first coating member 61, deterioration of the second coating member 62 due to ultraviolet light is reduced.

[0121] 7 , the second covering member 62 is disposed on the first covering member 61, but not on the wiring board 10. However, this is not limiting, and the second covering member 62 may be disposed on the wiring board 10 and cover the top and side surfaces of the first covering member 61. Also, the second covering member 62 may be disposed on the wiring board 10 and cover the top and inner surfaces of the first covering member 61. Also, the second covering member 62 may be disposed on the wiring board 10 and cover the top and outer surfaces of the first covering member 61.

[0122] 7 , the light emitting device 2 has one light emitting element 20 in an area surrounded by the first covering member 61 and the second covering member 62. However, this is not limiting, and the light emitting device 2 may have multiple light emitting elements 20 in an area surrounded by the first covering member 61 and the second covering member 62.

[0123] The preferred embodiments have been described above in detail. However, 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.

[0124] In addition to the above embodiments, the following supplementary notes are further disclosed. (Supplementary Note 1) A light-emitting device comprising: a light-emitting element; a first covering member having a resin as a base material and covering a bottom surface and / or side surfaces of the light-emitting element; a second covering member positioned above the first covering member and made of an inorganic material; and a granular member disposed between the first covering member and the second covering member, wherein the granular member includes inorganic particles in contact with both the first covering member and the second covering member. (Supplementary Note 2) The light-emitting device according to Supplementary Note 1, wherein the granular member is disposed along the interface between the first covering member and the second covering member and includes a plurality of inorganic particles in contact with both the first covering member and the second covering member. (Supplementary Note 3) The light-emitting device according to Supplementary Note 2, wherein the granular member includes a plurality of inorganic particles disposed within the first covering member along the interface between the first covering member and the second covering member. (Supplementary Note 4) The light-emitting device according to any one of Supplements 1 to 3, wherein the granular member includes scale-like inorganic particles. (Appendix 5) The light emitting device according to any one of Appendices 1 to 4, wherein the first covering member is a light reflective member containing a first light reflecting material, and the second covering member is a light reflective member containing a second light reflecting material, silicon oxide, and an alkali metal. (Appendix 6) The light emitting device according to any one of Appendices 1 to 5, further comprising a light-transmitting member disposed on the light emitting element, and the second covering member covering a side surface of the light-transmitting member. (Appendix 7) The light emitting device according to Appendices 6, wherein the light-transmitting member includes a wavelength converting material. (Appendix 8) The light emitting device according to any one of Appendices 1 to 7, further comprising a wiring board having wiring to which the light emitting element is electrically connected, and the first covering member covering the wiring. (Appendix 9) The light emitting device according to any one of Appendices 1 to 8, wherein an interface between the first covering member and the second covering member has an inclined surface that is inclined with respect to an upper surface of the light emitting element. (Appendix 10) A method for manufacturing a light emitting device, comprising the steps of: preparing a light emitting element having a bottom surface, a top surface, and side surfaces; arranging a first coating member having a resin as a base material on the bottom surface and / or side surfaces of the light emitting element; arranging a granular member on the first coating member; and arranging a second coating member made of an inorganic material on the first coating member and the granular member.(Supplementary Note 11) The method for manufacturing a light emitting device according to Supplementary Note 10, further comprising the step of: arranging the first covering member while the first covering member is uncured; and curing the uncured first covering member after the step of arranging the granular member and before the step of arranging the second covering member. (Supplementary Note 12) The method for manufacturing a light emitting device according to Supplementary Note 10 or 11, further comprising the step of arranging a translucent member on the light emitting element before the step of arranging the first covering member; and in the step of arranging the second covering member, the second covering member is arranged on a side surface of the translucent member.

[0125] This international application claims priority based on Japanese Patent Application No. 2023-108171, filed on June 30, 2023, the entire contents of which are incorporated herein by reference.

[0126] REFERENCE SIGNS LIST 1, 1A, 2 Light emitting device 10 Wiring substrate 11 Base material 12 Upper surface wiring 13 Lower surface wiring 20 Light emitting element 20a Upper surface 20b Lower surface 20c Side surface 25 Electrode 30 Protective element 40 Light guiding member 50 Light-transmitting member 50a Upper surface 50b Lower surface 50c Side surface 60i Interface 61 First covering member 62 Second covering member 70 Granular member 75, 75a, 75b Inorganic particles 300 Support

Claims

1. A light-emitting device comprising: a light-emitting element; a first coating member having a resin as a base material and covering a bottom surface and / or a side surface of the light-emitting element; a second coating member located above the first coating member and made of an inorganic material; and a granular member disposed between the first coating member and the second coating member, the granular member including inorganic particles in contact with both the first coating member and the second coating member.

2. The light-emitting device of claim 1, wherein the granular member includes a plurality of inorganic particles arranged along the interface between the first coating member and the second coating member and in contact with both the first coating member and the second coating member.

3. The light emitting device according to claim 2, wherein the granular member comprises a plurality of inorganic particles disposed within the first coating member along an interface between the first coating member and the second coating member.

4. The light emitting device according to claim 1, wherein the granular material includes scale-like inorganic particles.

5. A light-emitting device described in any one of claims 1 to 4, wherein the first coating member is a light-reflective member containing a first light-reflecting material, and the second coating member is a light-reflective member containing a second light-reflecting material, silicon oxide, and an alkali metal.

6. The light emitting device according to any one of claims 1 to 5, further comprising a translucent member disposed on the light emitting element, the second covering member covering a side surface of the translucent member.

7. The light emitting device according to claim 6, wherein the light-transmitting member includes a wavelength converting material.

8. The light emitting device according to any one of claims 1 to 7, further comprising a wiring board having wiring to which the light emitting element is electrically connected, the first covering member covering the wiring.

9. The light emitting device according to any one of claims 1 to 8, wherein the interface between the first covering member and the second covering member has an inclined surface that is inclined with respect to the upper surface of the light emitting element.

10. A method for manufacturing a light-emitting device, comprising the steps of: preparing a light-emitting element having a bottom surface, a top surface and a side surface; arranging a first coating member having a resin as a base material on the bottom surface and / or side surface of the light-emitting element; arranging a granular member on the first coating member; and arranging a second coating member made of an inorganic material on the first coating member and the granular member.

11. A method for manufacturing a light-emitting device as described in claim 10, wherein the step of placing the first coating member further includes a step of placing an uncured first coating member, and curing the uncured first coating member after the step of placing the granular member and before the step of placing the second coating member.

12. A method for manufacturing a light-emitting device as described in claim 10 or 11, further comprising a step of placing a translucent member on the light-emitting element prior to the step of placing the first covering member, and in the step of placing the second covering member, the second covering member is placed on a side surface of the translucent member.

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