Light emitting device and method for manufacturing light emitting device

Abstract

To provide a light emitting device capable of increasing light emission intensity to the side, and to provide a method of manufacturing the light emitting device.SOLUTION: The light emitting device includes a light emitting element, a light-transmissive member disposed on an upper surface and lateral surfaces of the light emitting element, and a light-diffusing member disposed on the upper surface of the light-transmissive member, wherein the lateral surfaces of the light-transmissive member are exposed from the light-diffusing member, a distance between the upper surface of the light emitting element and the upper surface of the light-transmissive member is greater than a distance between the lateral surfaces of the light emitting element and the lateral surfaces of the light-transmissive member, the upper surface of the light-transmissive member includes at least one first protrusion, and the light-diffusing member is in contact with a surface of the at least one first protrusion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] For example, Patent Document 1 discloses a light emitting device having a batwing-type light distribution characteristic. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-154204 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a light emitting device capable of increasing the lateral light emission intensity, and a method for manufacturing the light emitting device. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, a light-emitting device includes a light-emitting element, a translucent member arranged on an upper surface and a side surface of the light-emitting element, and a light-diffusing member arranged on the upper surface of the light-transmitting member, wherein the side surface of the light-transmitting member is exposed from the light-diffusing member, the distance between the upper surface of the light-emitting element and the upper surface of the light-transmitting member is longer than the distance between the side surface of the light-emitting element and the side surface of the light-transmitting member, the upper surface of the light-transmitting member has one or more first convex portions, and the light-diffusing member contacts the surfaces of the one or more first convex portions.

[0006] According to one aspect of the present disclosure, a method for manufacturing a light emitting device includes the steps of: preparing a first structure having a plurality of light emitting elements and a first light-transmissive member in a cured state covering upper and side surfaces of the light emitting elements; preparing a second structure having a second light-transmissive member in an uncured state and a light diffusing member in a cured state disposed on an upper surface of the second light-transmissive member, the upper surface of the second light-transmissive member having one or more first convex portions and the light diffusing member contacting a surface of the one or more first convex portions; overlapping the first structure and the second structure such that the first light-transmissive member of the first structure and the second light-transmissive member of the second structure face each other, and curing the second light-transmissive member to form a third structure; and cutting the third structure at a position where no light emitting element is disposed in a top view, thereby singulating the third structure into a plurality of light emitting devices. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a light emitting device capable of increasing the lateral light emission intensity, and a method for manufacturing a light emitting device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic top view of a light emitting device according to an embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a schematic top view of a light-transmitting member in the light-emitting device according to the embodiment. [Figure 4] FIG. 10 is a schematic cross-sectional view of a light emitting device according to a first modified example of the embodiment. [Figure 5] FIG. 10 is a schematic cross-sectional view of a light emitting device according to a second modified example of the embodiment. [Figure 6] FIG. 10 is a schematic top view of a light-transmitting member according to a second modified example of the embodiment. [Figure 7] FIG. 10 is a schematic cross-sectional view of a light emitting device according to a third modified example of the embodiment. [Figure 8] FIG. 10 is a schematic top view of a light-transmitting member according to a third modified example of the embodiment. [Figure 9] FIG. 10 is a schematic cross-sectional view of a light emitting device according to a fourth modified example of the embodiment. [Figure 10] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 11] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 12] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 13] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 14] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 15] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 16] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 17] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 18] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 19] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 20] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 21A] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 21B] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 21C] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. [Figure 21D] 5A to 5C are schematic cross-sectional views illustrating a step in a method for manufacturing a light emitting device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a light-emitting device according to an embodiment will be described with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to be limiting unless otherwise specified, and are merely illustrative examples. Note that the size and positional relationship of components shown in each drawing may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate the same or similar components, and detailed description will be omitted as appropriate. Furthermore, as cross-sectional views, end views showing only the cut surface may be used.

[0010] In the following description, terms indicating specific directions or positions (e.g., "above," "below," and other terms including these terms) may be used. However, these terms are used merely to facilitate understanding of relative directions or positions in the referenced drawings. As long as the relative direction or position relationship indicated by terms such as "above" and "below" in the referenced drawings is the same, drawings other than those disclosed herein, actual products, etc. may not have the same arrangement as in the referenced drawings. In this specification, the positional relationship expressed as "above (or below)" includes, for example, when two components are assumed to exist, a case in which the two components are in contact with each other, and a case in which the two components are not in contact with each other and one component is located above (or below) the other component.

[0011] In the figures shown below, directions may be indicated by the mutually orthogonal X-axis, Y-axis, and Z-axis. For example, in this specification, the direction of the X-axis is referred to as the first direction X, the direction of the Y-axis as the second direction Y, and the direction of the Z-axis as the third direction Z. Furthermore, the arrow direction of the Z-axis (positive direction) is referred to as relatively upward, and the opposite direction to the arrow direction (negative direction) is referred to as relatively downward. The first direction X side or the second direction Y side may be referred to as the "side." Furthermore, "top view" and "top view" refer to viewing an object from the arrow direction of the Z-axis.

[0012] In this specification, the "unreacted state" of a resin refers to a state in which the resin has not been heated and the curing reaction has not yet begun. The "uncured state" of a resin refers to a state in which the resin has been heated and the curing reaction has occurred, and the resin is in the A-stage or B-stage. The "cured state" of a resin refers to a state in which the resin has completely cured, and the resin is in the C-stage. The A stage, B stage, and C stage, which indicate the curing state of the resin, are defined as follows according to the JISK6800 standard. Stage A: The initial stage of the thermosetting resin production reaction. Resin in this state is still soluble in certain solvents and melts when heated. B stage: The intermediate curing state of thermosetting resin. Resin in this state softens when heated and swells when exposed to certain solvents, but does not completely melt or dissolve. C stage: The final stage of the thermosetting resin curing reaction. The resin in this stage is insoluble and infusible.

[0013] [Light-emitting device] A light emitting device 100 according to an embodiment will be described with reference to FIGS.

[0014] 1, the shape of the light emitting device 100 in top view is a rectangle having two sides extending in a first direction X and two sides extending in a second direction Y. The length of each side of the light emitting device 100 is, for example, 0.8 mm or more and 2.5 mm or less. The thickness of the light emitting device 100 is, for example, 0.8 mm or more and 3.0 mm or less.

[0015] Fig. 2 is a schematic cross-sectional view taken along line II-II in Fig. 1. The light emitting device 100 includes a light emitting element 11, a light-transmitting member 20, and a light diffusing member 30.

[0016] <Light-emitting element> 1, the shape of light emitting element 11 in top view is rectangular. In top view, each side of light emitting element 11 is parallel to each side of light emitting device 100. The length of each side of light emitting element 11 is, for example, not less than 640 μm and not more than 1300 μm. As shown in FIG. 2, the light emitting element 11 has an upper surface 11A, a lower surface 11B, and a side surface 11C.

[0017] The light emitting element 11 is, for example, an LED (Light Emitting Diode) element. The light emitting element 11 has a semiconductor structure. The semiconductor structure has an n-side semiconductor layer, a p-side semiconductor layer, and a light emitting layer located between the n-side semiconductor layer and the p-side semiconductor layer. The n-side semiconductor layer contains n-type impurities. The p-side semiconductor layer contains p-type impurities. The light emitting layer has a double heterojunction, a single quantum well (SQW), or a multiple quantum well (MQW) including multiple well layers. Each of the n-side semiconductor layer, the light emitting layer, and the p-side semiconductor layer is a semiconductor layer made of, for example, a nitride semiconductor. The nitride semiconductor is, for example, 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.

[0018] When a structure including an n-side semiconductor layer, a p-side semiconductor layer, and a light-emitting layer is formed as a single stack, the semiconductor structure can include multiple stacks. In this case, the multiple stacks are stacked in the third direction Z. In the semiconductor structure, the light-emitting layers of each of the multiple stacks may include well layers with different emission peak wavelengths or well layers with the same emission peak wavelength. Note that the same emission peak wavelength also includes cases where there is a variation of about several nanometers. The combination of emission peak wavelengths between the multiple active layers can be selected appropriately. For example, when the semiconductor structure includes two stacks, the combination of light emitted by the light-emitting layers of each stack can be blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light. For example, when the semiconductor structure includes three stacks, the combination of light emitted by the light-emitting layers of each stack can be blue light, green light, and red light.

[0019] The light emitting element 11 further has element electrodes. The element electrodes are located on the lower surface 11B side of the light emitting element 11 and include an n-side element electrode electrically connected to the n-side semiconductor layer and a p-side element electrode electrically connected to the p-side semiconductor layer. Furthermore, the light emitting element 11 may or may not have an element substrate such as sapphire on the upper surface side of the semiconductor structure.

[0020] <Translucent member> 3 is a schematic top view of the upper surface of the light-transmitting member 20 in the light-emitting device 100 according to this embodiment. The cross section of the light-transmitting member 20 shown in FIG. 2 is taken along line II-II in FIG.

[0021] The light-transmitting member 20 is disposed on the upper surface 11A and the side surface 11C of the light-emitting element 11. Light emitted by the light-emitting element 11 enters the light-transmitting member 20 from the upper surface 11A and the side surface 11C of the light-emitting element 11.

[0022] The light-transmitting member 20 includes a first base material and a wavelength converting material that converts the wavelength of the light emitted by the light-emitting element 11. The first base material is transparent to the light emitted by the light-emitting element 11. For example, a resin having excellent heat resistance, weather resistance, and light resistance can be used as the first base material. For example, a silicone resin, an epoxy resin, a urea resin, a phenolic resin, an acrylic resin, a urethane resin, or a fluororesin, or a thermosetting resin containing two or more of these resins can be used as the resin of the first base material.

[0023] For example, a phosphor can be used as the wavelength conversion material. For example, an yttrium-aluminum-garnet phosphor (e.g., Y3(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), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu), SLA-based phosphors (e.g., SrLiAlN:Eu), CASN-based phosphors (e.g., CaAlSiN:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN:Eu); fluoride-based phosphors such as KSF-based phosphors (e.g., KSiF:Mn), KSAF-based phosphors (e.g., K(Si,Al)F:Mn), or MGF-based phosphors (e.g., 3.5MgO·0.5MgF·GeO:Mn); phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)); or quantum dot phosphors (e.g., CdSe, InP, AgInS, or AgInSe).

[0024] The wavelength converting material contained in the light-transmitting member 20 may be one type of wavelength converting material or multiple types of wavelength converting materials. When multiple types of wavelength converting materials are used, the multiple types of wavelength converting materials may be disposed throughout the entire light-transmitting member 20, or the light-transmitting member 20 may be divided into multiple layers, with the multiple types of wavelength converting materials disposed in each layer. For example, when two types of wavelength converting materials are disposed in two layers, the light-transmitting member 20 may include a first layer disposed on the side surface 11C and upper surface 11A of the light-emitting element 11 and containing a first wavelength converting material, and a second layer disposed on the outer side surface and upper surface of the first layer and containing a second wavelength converting material.

[0025] The light-transmitting member 20 may or may not contain a wavelength converting material.

[0026] 3, the light-transmitting member 20 has a rectangular shape when viewed from above, and has four side surfaces 20A. In the example shown in FIG. 2, all of the four side surfaces 20A of the light-transmitting member 20 are not covered by the light diffusing member 30 and are exposed from the light diffusing member 30.

[0027] The upper surface of the light-transmitting member 20 has one or more first protrusions 21. In the example shown in Fig. 2 and Fig. 3, the upper surface of the light-transmitting member 20 has a plurality of first protrusions 21. In the example shown in Fig. 3, the plurality of first protrusions 21 are regularly arranged in the first direction X and the second direction Y such that the distances between the centers of adjacent first protrusions 21 are the same.

[0028] For example, the surface of the first convex portion 21 is curved. In the example shown in FIGS. 2 and 3, the first convex portion 21 has a hemispherical shape in a cross-sectional view and a circular shape in a top view. The top surface of the light-transmitting member 20 has a flat portion 23 parallel to the top surface 11A of the light-emitting element 11 in an area other than the first convex portions 21. The flat portion 23 has an outer flat portion 23B surrounding the first convex portions 21 that are arranged at the outermost periphery among the multiple first convex portions 21 in a top view. The flat portion 23 also has an inner flat portion 23A located between adjacent first convex portions 21 in a direction inclined with respect to the first direction X and the second direction Y. In the example shown in FIGS. 2 and 3, the inner flat portion 23A is not provided between adjacent first convex portions 21 in the first direction X. The inner flat portion 23A is also not provided between adjacent first convex portions 21 in the second direction Y. However, this is not limiting, and the inner flat portion 23A may be provided between the first convex portions 21 adjacent to each other in the first direction X. Also, the inner flat portion 23A may be provided between the first convex portions 21 adjacent to each other in the second direction Y.

[0029] In a top view, the ratio of the area of ​​the upper surface of the light-transmitting member 20 that is occupied by the first convex portions 21 to the area that overlaps with the upper surface 11A of the light-emitting element 11 is preferably 50% or more and 100% or less. This makes it possible to increase the amount of light that is refracted by the first convex portions 21 toward the side surface 30A of the light diffusing member 30 out of the light emitted upward from the light-emitting element 11.

[0030] <Light diffusing material> The light diffusing member 30 is disposed on the upper surface of the light-transmitting member 20. In the example shown in Fig. 1, the light diffusing member 30 has a rectangular shape when viewed from above. The light diffusing member 30 has four side surfaces 30A that are continuous with the four side surfaces 20A of the light-transmitting member 20 in the third direction Z. In addition, in the example shown in Fig. 2, the upper surface 30B of the light diffusing member 30 is a flat surface.

[0031] The light diffusing member 30 contacts the surfaces of the first convex portions 21 of the light-transmitting member 20. The light diffusing member 30 also contacts the surfaces of the flat portions 23 of the light-transmitting member 20. The interfaces between the light-transmitting member 20 and the light diffusing member 30 are located on the surfaces of the first convex portions 21 and the flat portions 23.

[0032] The light diffusing member 30 includes a second base material and a first light reflecting material. The second base material is transparent to the light emitted by the light emitting element 11 and the light whose wavelength has been converted by the wavelength converting material of the light-transmitting member 20. For example, the resins listed as the first base material of the light-transmitting member 20 can be used as the second base material.

[0033] For example, particles of silicon oxide, titanium oxide, aluminum oxide, barium titanate, or the like can be used as the first light-reflecting material contained in light diffusing member 30. Light diffusing member 30 may contain a filler for adjusting viscosity in addition to the light-reflecting material.

[0034] Of the light emitted by the light emitting element 11, the light that has not been wavelength-converted by the wavelength converting material and the light that has been wavelength-converted by the wavelength converting material are incident on the light diffusing member 30 from the upper surface of the light-transmitting member 20. The light diffusing member 30 diffuses the light that has entered from the upper surface of the light-transmitting member 20.

[0035] The refractive index of the second base material of the light diffusing member 30 is higher than the refractive index of the first base material of the light-transmitting member 20. This reduces reflection of light incident on the light diffusing member 30 from the light-transmitting member 20 at the interface between the first base material and the second base material, thereby improving the light extraction efficiency of the light emitting device 100.

[0036] The second base material of the light diffusing member 30 can be, for example, a phenyl silicone resin. In this case, the first light reflecting material is preferably silicon oxide. The difference in refractive index between the phenyl silicone resin and silicon oxide can be smaller than the difference in refractive index between the phenyl silicone resin and titanium oxide. By reducing the difference in refractive index between the second base material and the first light reflecting material in the light diffusing member 30, it is possible to reduce the amount of returning light that is reflected at the interface between the second base material and the first light reflecting material and returns into the light-transmitting member 20.

[0037] The light emitting surface of the light emitting device 100 includes the upper surface 30B of the light diffusing member 30, the side surface 30A of the light diffusing member 30, and the side surface 20A of the light-transmitting member 20. Light that is a mixture of light emitted by the light emitting element 11 that has not been wavelength-converted by the wavelength converting material and light that has been wavelength-converted by the wavelength converting material is emitted from the upper surface 30B of the light diffusing member 30, the side surface 30A of the light diffusing member 30, and the side surface 20A of the light-transmitting member 20.

[0038] In the example shown in FIG. 2 , the side surfaces of the light-emitting device 100 (i.e., the side surface 20A of the light-transmissive member 20 and the side surface 30A of the light diffusing member 30) are perpendicular to the top surface of the light-emitting device 100 (i.e., the top surface 30B of the light diffusing member 30). However, this is not limiting, and the side surfaces of the light-emitting device 100 may be surfaces that are inclined with respect to the top surface of the light-emitting device 100. When the side surfaces of the light-emitting device 100 are inclined with respect to the top surface of the light-emitting device 100, for example, the side surfaces of the light-emitting device 100 can be inclined so that the width of the light-emitting device 100 in the first direction X narrows from the bottom end to the top end of the side surfaces of the light-emitting device 100.

[0039] In the example shown in Figure 2, in the third direction Z, there is no step between the side surface 20A of the light-transmitting member 20 and the side surface 30A of the light-diffusing member 30, and the side surface 20A of the light-transmitting member 20 and the side surface 30A of the light-diffusing member 30 are continuous in the same plane.

[0040] The light emitting device 100 according to the embodiment may or may not further include the components described below.

[0041] <Electrode> In the example shown in FIG. 2 , two electrodes 12 are disposed on the underside of the light-emitting element 11. The electrodes 12 are electrically connected to the aforementioned device electrodes of the light-emitting element 11. One of the two electrodes 12 functions as an anode electrode, and the other functions as a cathode electrode. The light-emitting element 11 is electrically connected to a wiring substrate or the like via the electrodes 12. Examples of materials that can be used for the electrodes 12 include Cu, Ni, Ru, Au, Ag, Pt, Fe, and Su. The electrode 12 can have a first portion electrically connected to the device electrodes and surrounded by the light-reflective member 40 described below, and a second portion electrically connected to the first portion and disposed on the underside of the light-reflective member 40. When the light-emitting device 100 includes the electrodes 12, the electrodes 12 function as external connection terminals of the light-emitting device 100. When the light-emitting device 100 does not include the electrodes 12, the device electrodes of the light-emitting element 11 function as external connection terminals of the light-emitting device 100.

[0042] <Light-reflective material> The light-reflective member 40 is disposed on the lower surface 11B of the light-emitting element 11 and the lower surface of the light-transmitting member 20. The light-reflective member 40 also covers the side surfaces of the electrodes 12. The lower surfaces of the electrodes 12 are exposed from the light-reflective member 40.

[0043] The light-reflective member 40 has reflectivity for light emitted by the light-emitting element 11 that has not been wavelength-converted by the wavelength converting material, and for light that has been wavelength-converted by the wavelength converting material. The light-reflective member 40 reflects light that has traveled downward from the light-emitting element 11 and the light-transmitting member 20, toward the upper side of the light-reflective member 40. This increases the amount of light from the light-emitting surface (the upper surface 30B of the light-diffusing member 30, the side surface 30A of the light-diffusing member 30, and the side surface 20A of the light-transmitting member 20) of the light-emitting device 100.

[0044] The light-reflective member 40 includes a third base material and a second light-reflecting material. The third base material may be, for example, a resin listed as the first base material of the light-transmitting member 20. The second light-reflecting material may be, for example, a material listed as the first light-reflecting material of the light-diffusing member 30. The second light-reflecting material may be the same material as the first light-reflecting material, or may be a different material. The concentration of the second light-reflecting material in the light-reflective member 40 is higher than the concentration of the first light-reflecting material in the light-diffusing member 30. For example, the concentration of the second light-reflecting material in the light-reflective member 40 is 60 wt %, and the concentration of the first light-reflecting material in the light-diffusing member 30 is 4.72 wt %.

[0045] The thickness t3 of the light-reflecting member 40 is thinner than the thickness t1 of the light-transmitting member 20 and the thickness t2 of the light-diffusing member 30. The thickness t1 of the light-reflecting member 40 is, for example, not less than 0.015 mm and not more than 0.06 mm.

[0046] The light-emitting device 100 can have a light distribution characteristic (so-called batwing-type light distribution characteristic) in which a first luminous intensity peak, which is greater than the luminous intensity when the light distribution angle is 0°, is present within the light distribution angle range of 0° to −90° (excluding 0° and −90°) shown in FIG. 2 , and a second luminous intensity peak, which is greater than the luminous intensity when the light distribution angle is 0°, is present within the light distribution angle range of 0° to 90° (excluding 0° and 90°). The light distribution angle, as shown in FIG. 2 , refers to an angle α that represents the spread of light emitted from the light-emitting element 11 with respect to the optical axis L. As shown in the example of FIG. 2 , the light distribution angle α is expressed as +α° when the light is tilted in a first direction X (the direction of the arrow on the X-axis) with respect to the optical axis L, and as −α° when the light is tilted in a direction opposite to the first direction X (the direction of the arrow on the X-axis) with respect to the optical axis L. Here, the optical axis L refers to a normal line passing through the center of the upper surface 11A of the light-emitting element 11.

[0047] The refractive index of the second base material of the light diffusing member 30 is higher than the refractive index of the first base material of the light-transmitting member 20. Therefore, when the first convex portions 21 are arranged on the upper surface of the light-transmitting member 20, which is the interface between the light-transmitting member 20 and the light diffusing member 30, the light-emitting device 100 can refract light emitted by the light-emitting element 11 in a wider angle direction with respect to the optical axis L at the interface between the light-transmitting member 20 and the light diffusing member 30, compared to a light-emitting device in which the interface between the light-transmitting member 20 and the light diffusing member 30 is flat (hereinafter, this may be referred to as the "light-emitting device of Reference Example 1"). As a result, the light-emitting device 100 can increase the amount of light emitted from the side surface 30A of the light diffusing member 30, compared to the light-emitting device of Reference Example 1, and can increase the lateral light emission intensity of the light-emitting device 100. As a result, the light distribution characteristics of the light-emitting device 100 are such that the first luminous intensity peak is shifted to the -90° side and the second luminous intensity peak is shifted to the 90° side, compared to the light-emitting device of Reference Example 1.

[0048] By using the light-emitting device 100 as a light source for a lamp, for example, it is possible to reduce uneven brightness on the light-emitting surface of the lamp, even when the distance from the light-emitting device 100 to the light-emitting surface of the lamp is short due to the thinning of the lamp. Also, it is possible to make the light-emitting device 100 less likely to cause a spot-like glare to a person who has the light-emitting surface of the lamp in their field of vision. As a result, it is possible to make a lamp equipped with the light-emitting device 100 thinner, and to reduce the weight of the lamp due to the thinning.

[0049] Furthermore, the light-emitting device 100 in which the upper surface of the light-transmitting member 20 has the first convex portion 21 can increase the lateral light emission intensity in the light-emitting device 100 compared to a light-emitting device in which the upper surface of the light-transmitting member 20 does not have the first convex portion 21 and the upper surface 30B of the light-diffusing member 30 has a convex portion (a light-emitting device having a configuration in which the upper surface of the light-transmitting member 20 shown in FIG. 3 is replaced with the upper surface of the light-diffusing member 30). This is because the upper surface of the light-transmitting member 20, which is closer to the light-emitting element 11 in the third direction Z than the upper surface 30B of the light-diffusing member 30, can refract light from the light-emitting element 11 to the side of the light-emitting device 100, and the amount of light emitted from the side surface of the light-emitting device 100 can be increased.

[0050] Furthermore, in the light-emitting device 100 according to the embodiment, the side surface 20A of the light-transmissive member 20 is not covered by the light diffusing member 30 but is exposed from the light diffusing member 30. Alternatively, a light-emitting device having a configuration in which the side surface of the light-transmissive member 20 is covered by the light diffusing member 30 can be considered. For the same external size, in a light-emitting device having a configuration in which the side surface of the light-transmissive member 20 is covered by the light diffusing member 30, the distance between the side surface of the light-emitting element 11 and the side surface 20A of the light-transmissive member 20 is shorter than in the light-emitting device 100 according to the embodiment, thereby reducing the margin for misalignment of the light-emitting element 11 relative to the light-transmissive member 20. According to the light-emitting device 100 according to the embodiment, the distance d2 between the side surface of the light-emitting element 11 and the side surface 20A of the light-transmissive member 20 can be longer than in a light-emitting device having a configuration in which the side surface of the light-transmissive member 20 is covered by the light diffusing member 30, thereby reducing chromaticity unevenness in the light-emitting device 100 due to misalignment of the light-emitting element 11. According to the present embodiment, a light-emitting device 100 having a desired chromaticity distribution can be provided.

[0051] Furthermore, according to this embodiment, as shown in the example of FIG. 2, the distance d1 between the top surface 11A of the light-emitting element 11 and the top surface of the light-transmitting member 20 is longer than the distance d2 between the side surface 11C of the light-emitting element 11 and the side surface 20A of the light-transmitting member 20. The distance d1 represents the maximum distance along the third direction Z between the top surface 11A of the light-emitting element 11 and the top surface of the light-transmitting member 20. The distance d2 represents the maximum distance along the first direction X or the second direction Y between the side surface 11C of the light-emitting element 11 and the side surface 20A of the light-transmitting member 20. The distance d1 is, for example, not less than 220 μm and not more than 640 μm. The distance d2 is, for example, not less than 170 μm and not more than 360 μm.

[0052] The light emitted from the light-emitting element 11 includes a directly-above light component emitted from the top surface 11A of the light-emitting element 11 and a side light component emitted from the side surface 11C of the light-emitting element 11. The directly-above light component is greater than the side light component. By making the distance d1 longer than the distance d2, a relatively large amount of wavelength converting material is wavelength-converted by the directly-above light component, which is greater than the side light component, and a relatively small amount of wavelength converting material is wavelength-converted by the side light component, which is less than the directly-above light component. This reduces the variation in the ratio of wavelength-converted light to wavelength-converted light directly above and to the side of the light-emitting element 11, and makes it easier to reduce the variation in chromaticity directly above and to the side of the light-emitting device 100.

[0053] 2, the thickness t2 of the light diffusing member 30 is greater than the thickness t1 of the light-transmitting member 20. This increases the amount of mixed light of wavelength-converted light and wavelength-converted light that is emitted from the side surface 30A of the light diffusing member 30, thereby increasing the lateral light emission intensity in the light emitting device 100. Furthermore, the light emitting device 100 can be obtained with reduced chromaticity unevenness.

[0054] The thickness t1 of the light-transmitting member 20 represents the maximum thickness along the third direction Z between the lower surface and the upper surface of the light-transmitting member 20. The thickness t2 of the light-diffusing member 30 represents the maximum thickness along the third direction Z between the lower surface and the upper surface of the light-diffusing member 30. The thickness t1 of the light-transmitting member 20 is, for example, 0.36 mm or more and 0.91 mm or less. The thickness t2 of the light-diffusing member 30 is, for example, 0.63 mm or more and 1.46 mm or less. For example, the thickness t2 of the light-diffusing member 30 is 1.1 times or more and 2.0 times or less the thickness t1 of the light-transmitting member 20.

[0055] Furthermore, according to this embodiment, the total area of ​​the four side surfaces 20A of the light-transmitting member 20 and the four side surfaces 30A of the light diffusing member 30 is larger than the area of ​​the top surface 30B of the light diffusing member 30. This allows the amount of light emitted from all the side surfaces of the light-emitting device 100 to be greater than the amount of light emitted from the top surface, thereby increasing the lateral light emission intensity of the light-emitting device 100.

[0056] Furthermore, according to this embodiment, the ratio of the overall thickness H of light emitting device 100 to one side of light emitting device 100 in a top view can be 1.01 or more and 1.24 or less. The overall thickness H of light emitting device 100 shown in Fig. 2 is calculated by subtracting the maximum height h of first convex portions 21, which will be described later, from the sum of the thickness t1 of light-transmitting member 20, the thickness t2 of light diffusing member 30, and the thickness t3 of light-reflective member 40.

[0057] As in the light-emitting device 100A according to a first modification of the embodiment shown in FIG. 4, the upper surface of the light-transmissive member 20 can have a first convex portion 21 and a first concave portion 22. The first concave portion 22 is, for example, located outside the first convex portion 21 and is disposed so as to surround the first convex portion 21 in a top view. The light from the light-emitting element 11 is refracted by the first concave portion 22 toward the wide-angle side with respect to the optical axis L (i.e., toward the side of the light-emitting device 100A), and is refracted by the first concave portion 22 toward the low-angle side with respect to the optical axis L (i.e., toward the upper side of the light-emitting device 100A). As a result, the light emission intensity at a desired luminous intensity distribution angle can be increased.

[0058] When the upper surface of the light-transmitting member 20 has the flat portion 23, the surfaces of the first convex portions 21 are located above the flat portion 23 in the third direction Z. Furthermore, the surfaces of the first concave portions 22 are located below the flat portion 23 in the third direction Z. On the other hand, when the upper surface of the light-transmitting member 20 does not have the flat portion 23, the uppermost ends of the first convex portions 21 are located above a line connecting both ends of the interface between the light-transmitting member 20 and the light diffusing member 30 in a cross-sectional view. Furthermore, the lowermost ends of the first concave portions 22 are located below a line connecting both ends of the interface between the light-transmitting member 20 and the light diffusing member 30 in a cross-sectional view.

[0059] The upper surface of the light-transmitting member 20 is not limited to having a plurality of first convex portions 21, and may have one first convex portion 21. One first convex portion 21 can be disposed in a central portion that is a portion that includes at least the center of the upper surface of the light-transmitting member 20 when viewed from above.

[0060] In a top view, it is preferable that the center of the first convex portion 21 overlaps with the center of the light-emitting element 11. This reduces deviation in the light distribution characteristics. Here, deviation in the light distribution characteristics refers to a decrease in symmetry between the light distribution characteristics on the first direction X side (the arrow direction side of the X axis) with respect to the optical axis L and the light distribution characteristics on the opposite side of the first direction X with respect to the optical axis L.

[0061] In a cross-sectional view, the maximum width w of the first convex portion 21 (or the first concave portion 22) is, for example, 1 / 20 or more and 1 / 5 or less of the width of the light-transmitting member 20.

[0062] The maximum height h of the first convex portion 21 (or the first concave portion 22) is, for example, 0.5 to 2 times the maximum width w of the first convex portion 21 (or the first concave portion 22). The maximum height h of the first convex portion 21 (or the first concave portion 22) corresponds to the distance between the upper end and the lower end of the first convex portion 21 (or the first concave portion 22) in the third direction Z.

[0063] Consider the inclination angle θ of the oblique line 21S between the upper and lower ends of the first convex portion 21 in a cross-sectional view (if the oblique line 21S is curved, the inclination angle θ of the tangent line to the oblique line 21S). The inclination angle θ is based on a line connecting both ends of the interface between the light-transmitting member 20 and the light diffusing member 30 in a cross-sectional view. When the inclination angle θ is 45° or more and 76° or less, h is preferably 0.5 times or more and 2 times or less than w. When the inclination angle θ is 50° or more and 70° or less, h is preferably 0.6 times or more and 1.3 times or less than w.

[0064] Moreover, the inclination angle θ is preferably equal to or greater than 45°, which allows the amount of light refracted by the surface of the first convex portion 21 and directed toward the side surface 30A of the light diffusing member 30 to be increased.

[0065] 2 and 3, the surface of first convex portion 21 is curved. As a result, light from light-emitting element 11 is refracted in all directions in top view by first convex portion 21. As a result, the light distribution characteristic of light-emitting device 100 can be shifted in all circumferential directions in top view, with the first luminous intensity peak of the light distribution characteristic in each direction shifted to the -90° side and the second luminous intensity peak shifted to the 90° side, compared to the light distribution characteristic of the light-emitting device of Reference Example 1.

[0066] Fig. 5 is a schematic cross-sectional view of a light-emitting device 100B according to a second modified example of the embodiment. Fig. 6 is a schematic top view of the upper surface of the light-transmitting member 20 in the light-emitting device 100B according to the second modified example. The cross section of the light-transmitting member 20 shown in Fig. 5 is taken along line VV in Fig. 6.

[0067] In the light emitting device 100B according to the second modification, the shape of the first protrusion 21 is a quadrangular pyramid. The shape of the first protrusion 21 in a cross-sectional view is a triangle. In the example shown in FIG. 6, a plurality of first protrusions 21 are aligned in the first direction X and the second direction Y. Furthermore, the sides of the rectangle that defines the outer shape of the quadrangular pyramid of the first protrusion 21 in a top view are inclined with respect to the sides of the rectangle that is the shape of the light-transmitting member 20 in a top view. For example, the first protrusion 21 has two sides parallel to one of two diagonals of the rectangle of the light-transmitting member 20 in a top view and two sides parallel to the other diagonal.

[0068] The first convex portion 21 has two sides parallel to one of two diagonals of the rectangle of the light-transmitting member 20 in a top view and two sides parallel to the other diagonal. This allows the light emitted by the light-emitting element 11 to be refracted in a wide-angle direction with respect to the optical axis L at the interface between the light-transmitting member 20 and the light diffusing member 30 in the direction of line BB shown in FIG. 1 . This increases the amount of light emitted from the side surface of the light diffusing member 30 in the direction of line BB of the light-emitting device 100B. Furthermore, compared to the light-emitting device of Reference Example 1, the light-emitting device 100B can reduce the difference in luminous intensity between the direction passing through the center of the light-emitting device in a top view toward the corner of the light-emitting device (the direction of line BB shown in FIG. 1 ) and the direction passing through the center of the light-emitting device in a top view perpendicular to the side surface of the light-emitting device (the directions of line AA and line CC shown in FIG. 1 ), thereby reducing luminous intensity unevenness.

[0069] 6, the upper surface of the light-transmitting member 20 has flat portions 23 in areas other than the first convex portions 21. The flat portions 23 have outer flat portions 23B that surround the first convex portions 21 that are arranged at the outermost periphery among the multiple first convex portions 21 in a top view. The flat portions 23 also have inner flat portions 23A that are located between adjacent first convex portions 21 in a direction inclined with respect to the first direction X and the second direction Y.

[0070] In the light emitting device 100B, the upper surface of the light-transmitting member 20 is not limited to having the first convex portion 21 in a quadrangular pyramid shape. That is, the upper surface may have the first convex portion 21 in a quadrangular pyramid shape and the first concave portion in a quadrangular pyramid shape. Furthermore, the sides of the rectangle that defines the outer shape of the quadrangular pyramid of the first convex portion 21 in a top view are not limited to being inclined with respect to the sides of the rectangle that is the shape of the light-transmitting member 20 in a top view. That is, the sides of the rectangle that defines the outer shape of the quadrangular pyramid of the first convex portion 21 in a top view may be parallel to the sides of the rectangle of the light-transmitting member 20 in a top view.

[0071] 2 to 6, the upper surface of the light-transmitting member 20 has a plurality of first protrusions 21. The maximum height h of each of the first protrusions 21 is the same.

[0072] A light emitting device 100C according to a third modified example of the embodiment will be described with reference to Fig. 7 and Fig. 8. The cross section of the light-transmissive member 20 shown in Fig. 7 is taken along line VII-VII in Fig. 8.

[0073] The light emitting device 100C according to the third modification has a plurality of first protrusions 21, similar to the light emitting device 100. As shown in FIGS. 7 and 8 , the plurality of first protrusions 21, in a top view, have a central first protrusion 21A located in the center of the upper surface of the light-transmissive member 20 and outer first protrusions 21B located outward from the central first protrusion 21A. The maximum height of the central first protrusion 21A is greater than the maximum height of the outer first protrusions 21B. This reduces the amount of light refracted by the central first protrusion 21A and heading toward the side surface 30A of the light diffusing member 30 from being incident on the outer first protrusion 21B and heading toward the upper surface 30B of the light diffusing member 30 due to refraction by the outer first protrusion 21B.

[0074] In the example shown in FIG. 7, the central first protrusion 21A is composed of a first protrusion 21a located on the optical axis L and first protrusions 21b located on both sides of the first protrusion 21a, and the outer first protrusion 21B is composed of first protrusions 21c located on both sides of the central first protrusion 21A. When the central first protrusion 21A is composed of the first protrusion 21a and the first protrusion 21b, the maximum height of the first protrusion 21a may be higher than or the same as the maximum height of the first protrusion 21b. Note that the central first protrusion 21A is not limited to being composed of the first protrusion 21a and the first protrusion 21b. In other words, the central first protrusion 21A may be composed of only one first protrusion 21a. In this case, the outer first protrusion 21B is composed of the first protrusion 21b and the first protrusion 21c.

[0075] The plurality of first protrusions 21 may be arranged concentrically or radially with respect to the center of the upper surface 11A of the light emitting element 11 in a top view.

[0076] A light emitting device 100D according to a fourth modified example of the embodiment will be described with reference to Fig. 9. In the light emitting device 100D according to the fourth modified example, the upper surface 30B of the light diffusing member 30 has second recesses 32. The surface of the second recesses 32 is in contact with air, and light traveling inside the light diffusing member 30 is likely to be totally reflected at the interface between the second recesses 32 and the air. As a result, light that has been refracted by the first convex portions 21 and traveled toward the upper surface 30B of the light diffusing member 30 can be directed toward the side surface 30A by reflection at the interface between the second recesses 32 and the air.

[0077] For example, the shape of the second recess 32 is the inverted shape of the first protrusion 21 in the third direction Z. Furthermore, the second recess 32 is located at a position overlapping the first protrusion 21 in top view. The second recess 32 overlaps with the center of the upper surface 11A of the light-emitting element 11 in top view.

[0078] 9, the upper surface 30B of the light diffusing member 30 has a second recess 32 and a flat portion. The surface of the second recess 32 is located lower than the flat portion in the third direction Z.

[0079] Each of the light emitting devices 100, 100A to 100D includes one light emitting element 11. However, this is not limiting, and each of the light emitting devices 100, 100A to 100D may include multiple light emitting elements 11. In this case, it is preferable that the center of the first convex portion 21 overlaps with the center of the upper surface 11A of each of the multiple light emitting elements 11 when viewed from above. This allows the first convex portion 21 to refract the directly upward light component emitted from the upper surface 11A of each light emitting element 11 laterally.

[0080] In each of the light emitting devices 100, 100A to 100D, the light emitting element 11 is arranged on a substrate having a wiring layer, and the element electrode arranged on the upper surface 11A side of the light emitting element 11 can be electrically connected to the wiring layer of the substrate by, for example, a wire.

[0081] [Method of manufacturing a light-emitting device] A method for manufacturing the light emitting device 100 according to this embodiment will be described with reference to FIGS. 10 to 21D.

[0082] <Step of preparing the first structure> The manufacturing method of the light emitting device 100 according to the embodiment includes a step of preparing a first structure 200 shown in Fig. 14. The first structure 200 has a plurality of light emitting elements 11 and a first light-transmissive member 121 that covers an upper surface 11A (the surface on the support member 401 side in Fig. 14) and a side surface 11C of the light emitting elements 11.

[0083] The first structure 200 can be prepared, for example, by the steps shown in FIGS.

[0084] 10, a first light-transmissive member 121 is prepared. For example, a sheet-like first light-transmissive member 121 is formed by a coating device. The first light-transmissive member 121 is supported on a support member 401 via, for example, an adhesive member 402. The support member 401 is a metal plate such as stainless steel.

[0085] The first light-transmissive member 121 becomes part of the light-transmissive member 20 of the light-emitting device 100 described above through the process described below. Therefore, the first light-transmissive member 121 includes a first base material and a wavelength converting material. The first base material is, for example, a silicone resin, which is a thermosetting resin. In the process of preparing the first light-transmissive member 121 shown in FIG. 10, the resin of the first base material of the first light-transmissive member 121 is in an uncured state. The resin of the first base material of the first light-transmissive member 121 is, for example, in a B-stage state. Alternatively, in the process of preparing the first light-transmissive member 121, the resin of the first base material of the first light-transmissive member 121 may be in an A-stage state.

[0086] After preparing the sheet-like first light-transmissive member 121, a plurality of recesses 121A are formed in the first light-transmissive member 121 as shown in FIG. 11. The recesses 121A can be formed, for example, by pressing a mold to a predetermined depth from the upper surface of the first light-transmissive member 121 (i.e., the surface of the first light-transmissive member 121 opposite the surface on the adhesive member 402 side). The recesses 121A do not penetrate the first light-transmissive member 121. The depth D2 of the recesses 121A shown in FIG. 11 can be, for example, the distance D1 from the upper surface 11A to the lower surface 11B in the third direction Z of the light-emitting element 11 shown in FIG. 2. Furthermore, the width W2 of the recesses 121A shown in FIG. 11 may be the same as or longer than the distance W1 in the first direction X of the light-emitting element 11 shown in FIG. 2.

[0087] 12, a light emitting element 11 is placed in each of the recesses 121A, and the first light transmissive member 121 is then heated to harden the resin of the first base material to the C stage. By placing the light emitting element 11 in the recess 121A and then hardening the resin of the first base material of the first light transmissive member 121 to the C stage, it is possible to reduce misalignment of the light emitting element 11 with respect to the first light transmissive member 121.

[0088] In the step of placing the light emitting element 11 in the recess 121A of the first light-transmissive member 121, the upper surface 11A of the light emitting element 11 faces the bottom surface that defines the recess 121A. At this time, the surface of the light emitting element 11 on which the electrode 12 is to be placed is exposed from the first light-transmissive member 121. In the step of placing the light emitting element 11 in the recess 121A, the electrode 12 is placed on the lower surface 11B of the light emitting element 11. The lower surface 11B of the light emitting element 11 and the electrode 12 are exposed from the first light-transmissive member 121.

[0089] In the step of curing the resin of the first base material of the first light-transmissive member 121 to C stage, the heating temperature is, for example, about 150° C., and the heating time is about 6 hours.

[0090] After the resin of the first base material of the first light-transmissive member 121 is cured to C-stage, a light-reflective member 40 is formed on the lower surface 11B of the light-emitting element 11 so as to cover the electrode 12, as shown in FIG. 13. One method for forming the light-reflective member 40 is compression molding, for example. Thereafter, by grinding the front surface side of the light-reflective member 40, the surface of the electrode 12 located opposite the light-emitting element 11 is exposed from the light-reflective member 40, as shown in FIG. 14. Through the above steps, the first structure 200 can be prepared. Note that the formation of the electrode 12 and the light-reflective member 40 may be omitted.

[0091] <Step of preparing the second structure> 18 , the manufacturing method of the light emitting device 100 according to the embodiment includes a step of preparing a second structure 300. The second structure 300 has a second light-transmissive member 122 and a light diffusing member 30 disposed on the upper surface of the second light-transmissive member 122. The second light-transmissive member 122, together with the first light-transmissive member 121 described above, constitutes the light-transmissive member 20 of the light emitting device 100.

[0092] The second structure 300 can be prepared, for example, by the steps shown in FIGS.

[0093] The step of preparing the second structure 300 includes the steps of preparing an upper mold 501, a transfer sheet 504, and a lower mold 502 shown in FIG. 15. The upper surface of the lower mold 502 is flat, and a transfer sheet 504 is placed on the upper surface of the lower mold 502. A space 505 is defined by the upper mold 501 and the transfer sheet 504. If necessary, a release sheet 503 can be placed on the surface of the upper mold 501 facing the transfer sheet 504 across the space 505. In the example shown in FIG. 15, a plurality of fourth protrusions 504A and flat portions 504B located between the plurality of fourth protrusions 504A are placed on the upper surface of the transfer sheet 504 that contacts the space 505.

[0094] A mixture of unreacted resin and a light reflecting material, which will serve as the second base material of the light diffusing member 30, is supplied into a space 505 between the upper mold 501 and the transfer sheet 504, and compression molded within the space 505. As a result, as shown in FIG. 16 , a plurality of third recesses 31, each having the inverse shape of the fourth convex portions 504A of the transfer sheet 504, are formed on the surface of the light diffusing member 30 facing the transfer sheet 504. Furthermore, flat portions 33 are formed on the surface of the light diffusing member 30 facing the transfer sheet 504 at positions that contact the flat portions 504B of the transfer sheet 504. Furthermore, the surface of the light diffusing member 30 opposite the surface on which the third recesses 31 and flat portions 33 are formed is composed entirely of a flat surface. Hereinafter, the surface of the light diffusing member 30 on which the third recesses 31 are formed may be referred to as the lower surface of the light diffusing member 30. Furthermore, the surface of the light diffusing member 30 opposite the surface on which the third recesses 31 are formed may be referred to as the upper surface of the light diffusing member 30.

[0095] The second base material of the light diffusing member 30 is cured to the C stage in the space 505. For example, the second base material is first cured to the B stage at a heating temperature of about 125°C, a heating time of about 50 seconds, and a clamping force of about 700 kN. Then, the second base material is heated at about 150°C to be cured to the C stage.

[0096] After forming a light diffusing member 30 having a third recess 31 on its lower surface, as shown in FIG. 17, a second light-transmitting member 122 in an uncured state (A stage) is placed opposite the lower surface of the light diffusing member 30, and as shown in FIG. 18, the second light-transmitting member 122 in an uncured state is placed on the lower surface of the light diffusing member 30.

[0097] The upper surface of the uncured second light-transmissive member 122 contacts the lower surface of the light diffusing member 30, and first convex portions 21 that contact the third concave portions 31 of the light diffusing member 30 are formed on the upper surface of the second light-transmissive member 122. Furthermore, flat portions 23 that contact the flat portions 33 of the light diffusing member 30 are formed on the upper surface of the second light-transmissive member 122. In the second structure 300, the upper surface of the second light-transmissive member 122 has the first convex portions 21 and the flat portions 23, and the light diffusing member 30 contacts the surfaces of the first convex portions 21 and the flat portions 23.

[0098] Through the above steps, it is possible to prepare the second structure 300. In the second structure 300, the light diffusion member 30 is in a cured state (C stage), and the second light-transmissive member 122 is in an uncured state. In the second structure 300, the uncured second light-transmissive member 122 is not limited to being in the A stage, and may be in the B stage.

[0099] In the step of preparing the second structure 300, the transfer sheet 504 can have fourth convex portions and fourth concave portions. In this case, third concave portions having the inverse shape of the fourth convex portions are formed on the lower surface of the light diffusing member 30, and first convex portions having the inverse shape of the third concave portions are formed on the upper surface of the second light-transmissive member 122. Furthermore, third convex portions having the inverse shape of the fourth concave portions are formed on the lower surface of the light diffusing member 30, and first concave portions having the inverse shape of the third convex portions are formed on the upper surface of the second light-transmissive member 122.

[0100] In the step of preparing the second structure 300, the upper surface of the lower mold 502 is not limited to being flat, and the upper surface of the lower mold 502 may have a fourth convex portion. When the lower mold 502 has a fourth convex portion on the upper surface of the lower mold 502, the transfer sheet 504 can be omitted. Furthermore, the third concave portion and / or the third convex portion may be formed on the lower surface of the light diffusing member 30 by laser processing or etching processing without using a mold.

[0101] <Step of forming third structure> The method for manufacturing the light emitting device 100 according to this embodiment includes the step of forming a third structure 600 shown in FIG.

[0102] 19 and 20 , the first structure 200 and the second structure 300 are overlapped such that the cured first light-transmissive member 121 of the first structure 200 faces the uncured second light-transmissive member 122 of the second structure 300, and the second light-transmissive member 122 is cured to C-stage, thereby forming a third structure 600. After the surface 121S of the first light-transmissive member 121 facing the second structure 300 and the surface 122S of the second light-transmissive member 122 facing the first structure 200 are overlapped, the second light-transmissive member 122 is cured to C-stage by heating at a temperature of approximately 150° C. for approximately six hours, for example. The first light-transmissive member 121 and the second light-transmissive member 122 are bonded to form an integrated light-transmissive member 20.

[0103] In the process of forming the third structure 600, after the first structure 200 and the second structure 300 are stacked, a pressing force can be applied to the first structure 200 and the second structure 300 before heating. For example, as shown in the example of FIG. 21A , a structure 1000 formed by stacking the first structure 200 and the second structure 300 is placed in a lower mold 701, and an upper mold 702 having a pressing mechanism 800 on its underside is placed above the structure 1000. For example, silicone rubber can be used for the pressing mechanism 800. Thereafter, as shown in the examples of FIGS. 21B to 21D , the pressing mechanism 800 is inflated to press the structure 1000. The range over which the pressing force acts expands from the center of the structure 1000 toward the outer periphery when viewed from above. This makes it less likely for air bubbles to get into the bonding surface between the first light-transmissive member 121 and the second light-transmissive member 122 than when the range over which the pressing force acts expands from the outer periphery toward the center of the structure 1000 when viewed from above.

[0104] 21A, the structure 1000 is placed in the lower mold 701 so that the first structure 200 faces the lower mold 701. In this case, the second structure 300 is pressed by the pressing mechanism 800. However, this is not limiting, and the structure 1000 may be placed in the lower mold 701 so that the second structure 300 faces the lower mold 701. In this case, the first structure 200 is pressed by the pressing mechanism 800.

[0105] The pressing mechanism 800 can be arranged on the upper surface of the lower mold 701 in addition to the lower surface of the upper mold 702. In this way, the two pressing mechanisms 800 press the structure 1000 from both the first structure 200 side and the second structure 300 side.

[0106] For example, as Reference Example 2, a manufacturing method can be considered in which a light-emitting element-side structure is prepared by forming a light-transmissive member 20 so as to cover a plurality of light-emitting elements 11, and a light diffusing member 30 is bonded to the upper surface of the light-transmissive member 20 of the structure to form a third structure 600. In contrast, the present embodiment is a method in which a first light-transmissive member 121 of a first structure 200 and a second light-transmissive member 122 of a second structure 300 are bonded to form the third structure 600. Compared to Reference Example 2, this embodiment can reduce the force applied to the light-emitting element 11 during bonding, thereby reducing damage to the light-emitting element 11. This can improve the reliability of the light-emitting device 100.

[0107] Furthermore, in the manufacturing method of Reference Example 2, the light-transmissive member 20 is heated and cured to a thickness greater than that of the first light-transmissive member 121 and the second light-transmissive member 122, and therefore heat is not transmitted to the center of the light-transmissive member 20 in the thickness direction, which may result in uneven curing. In contrast, in the present embodiment, the first light-transmissive member 121 and the second light-transmissive member 122 are heated and cured separately. Therefore, the first light-transmissive member 121 and the second light-transmissive member 122 are heated and cured in a state where they are thinner than the light-transmissive member 20. This reduces uneven curing of the first light-transmissive member 121 and the second light-transmissive member 122, and improves the reliability of the light-emitting device 100.

[0108] The above describes a case where the first light-transmissive member 121 is in a cured state and the second light-transmissive member 122 is in an uncured state in the step of joining the first light-transmissive member 121 and the second light-transmissive member 122. However, this is not limiting, and the first light-transmissive member 121 may be in an uncured state and the second light-transmissive member 122 may be in a cured state in the step of joining the first light-transmissive member 121 and the second light-transmissive member 122.

[0109] Furthermore, in the step of bonding the first light-transmissive member 121 and the second light-transmissive member 122, it is not necessary that either one of the first light-transmissive member 121 or the second light-transmissive member 122 is in an uncured state. That is, in the step of bonding the first light-transmissive member 121 and the second light-transmissive member 122, both the first light-transmissive member 121 and the second light-transmissive member 122 may be in an uncured state. When either the first light-transmissive member 121 or the second light-transmissive member 122 is in an uncured state, misalignment between the first structure 200 and the second structure 300 is less likely to occur, and air bubbles are less likely to be trapped at the bonding surface between the first light-transmissive member 121 and the second light-transmissive member 122, compared to when both are in an uncured state.

[0110] Furthermore, if the first light-transmissive member 121 covering the plurality of light-emitting elements 11 is in a hardened state as in this embodiment, the positional deviation of each light-emitting element 11 relative to the first light-transmissive member 121 in the first structure 200 can be reduced, and therefore the first light-transmissive member 121 and the second light-transmissive member 122 can be bonded with high precision in the process of bonding them together.

[0111] In the step of joining the first light-transmissive member 121 and the second light-transmissive member 122, the first light-transmissive member 121 may be in an uncured state, and the second light-transmissive member 122 may be in a cured state.

[0112] The surface roughness of the surface 121S of the first light-transmissive member 121 of the first structure 200, which faces the second structure 300, is preferably smaller than the surface roughness of the surface 122S of the second light-transmissive member 122 of the second structure 300, which faces the first structure 200. By making the surface 121S of the first light-transmissive member 121 in a cured state flatter than the surface 122S of the second light-transmissive member 122 in an uncured state, misalignment is less likely to occur when the first light-transmissive member 121 and the second light-transmissive member 122 are joined. Furthermore, when the first light-transmissive member 121 and the second light-transmissive member 122 are joined, the surface 122S of the uncured second light-transmissive member 122 is joined so as to conform to the flatter surface 121S of the first light-transmissive member 121 in a cured state, which makes it less likely for air bubbles to be trapped at the joint surface between the first light-transmissive member 121 and the second light-transmissive member 122.

[0113] In the step of preparing the second structure 300, the thickness of the second light-transmissive member 122 is preferably thinner than the thickness of the light diffusing member 30. This allows the position of the first convex portion 21 located at the interface between the second light-transmissive member 122 and the light diffusing member 30 to be closer to the light emitting element 11, making it easier to direct the refracted light at the first convex portion 21 toward the side surface 30A of the light diffusing member 30.

[0114] <Step of Slicing the Third Structure into Multiple Light-Emitting Devices> The method for manufacturing the light emitting device 100 according to the embodiment includes a step of forming the third structure 600 and then dividing the third structure 600 into a plurality of light emitting devices 100.

[0115] The third structure 600 is cut at a position where no light emitting element 11 is arranged when viewed from above, and the third structure 600 is divided into a plurality of light emitting devices 100. This results in the light emitting devices 100 shown in Figures 1 and 2. For example, the third structure 600 can be cut using a blade or laser light.

[0116] For example, the third structure 600 is cut at the position of the flat portion 23 at the interface between the light diffusing member 30 and the light-transmitting member 20, and the third structure 600 is separated into a plurality of light emitting devices 100. In this case, it is easy to identify the cutting positions.

[0117] 4, when the upper surface of the light-transmitting member 20 has a first recess 22, the third structure 600 may be cut at the position of the upper end of the first recess 22, and the third structure 600 may be cut at the position of the upper end of the first recess 22, and the third structure 600 may be cut into the plurality of light-emitting devices 100.

[0118] If the upper surface 30B of the light diffusing member 30 is a flat surface, when transporting the light emitting device 100 after singulation, it becomes easy to pick up the light emitting device 100 by vacuum suction or adsorption of the upper surface 30B of the light diffusing member 30.

[0119] Embodiments of the present disclosure may include the following light emitting device and method for manufacturing the light emitting device.

[0120] [Section 1] A light-emitting element; a light-transmitting member disposed on an upper surface and a side surface of the light-emitting element; a light diffusing member disposed on an upper surface of the light-transmitting member; Equipped with a side surface of the light-transmitting member is exposed from the light diffusing member; a distance between an upper surface of the light-emitting element and an upper surface of the light-transmitting member is longer than a distance between a side surface of the light-emitting element and a side surface of the light-transmitting member; the upper surface of the light-transmitting member has one or more first convex portions, The light emitting device, wherein the light diffusing member is in contact with a surface of one or more of the first convex portions. [Section 2] Item 2. The light emitting device according to item 1, wherein the thickness of the light diffusing member is greater than the thickness of the light-transmitting member. [Section 3] Item 3. The light emitting device according to item 1 or 2, wherein the surface of the first convex portion is a curved surface. [Section 4] 3. The light emitting device according to item 1 or 2, wherein the first convex portion has a quadrangular pyramid shape. [Section 5] the light-transmitting member has a rectangular shape in a top view, Item 5. The light emitting device according to item 4, wherein the sides of the rectangle that defines the outer shape of the quadrangular pyramid in the top view of the first convex portion are inclined or parallel to the sides of the rectangle of the translucent member. [Section 6] 6. The light emitting device according to any one of items 1 to 5, wherein the center of the first convex portion and the center of the light emitting element overlap in top view. [Section 7] 7. The light emitting device according to any one of items 1 to 6, wherein the maximum width of the first convex portion is 1 / 20 to 1 / 5 of the width of the light-transmitting member in a cross-sectional view. [Section 8] Item 8. The light emitting device according to any one of items 1 to 7, wherein the maximum height of the first convex portion is 0.5 to 2 times the maximum width of the first convex portion. [Section 9] Item 9. The light emitting device according to any one of items 1 to 8, wherein the upper surface of the light diffusing member has second recesses at positions that overlap the first protrusions in a top view. [Section 10] the upper surface of the light-transmitting member has a plurality of the first convex portions, the plurality of first convex portions include a central first convex portion located at the center of the upper surface of the light-transmitting member in a top view, and outer first convex portions located outside the central first convex portion, Item 10. The light emitting device according to any one of items 1 to 9, wherein the maximum height of the central first convex portion is greater than the maximum height of the outer first convex portion. [Section 11] preparing a first structure having a plurality of light-emitting elements and a first light-transmissive member in a hardened state that covers upper and side surfaces of the light-emitting elements; preparing a second structure including an uncured second light-transmitting member and a cured light diffusing member disposed on an upper surface of the second light-transmitting member, wherein the upper surface of the second light-transmitting member has one or more first convex portions, and the light diffusing member is in contact with a surface of the one or more first convex portions; forming a third structure by stacking the first structure and the second structure such that the first light-transmissive member of the first structure and the second light-transmissive member of the second structure face each other and curing the second light-transmissive member; cutting the third structure at a position where the light emitting element is not arranged in a top view, and dividing the third structure into a plurality of light emitting devices; A method for manufacturing a light emitting device, comprising: [Section 12] The step of preparing the second structure includes: forming a plurality of third recesses and / or third protrusions on the lower surface of the uncured light diffusing member using a mold; curing the light diffusing member; placing the uncured second light-transmitting member on the lower surface of the light diffusing member; Item 12. A method for producing a light-emitting device according to item 11, comprising: [Section 13] Item 13. The method for manufacturing a light emitting device according to item 11 or 12, wherein in the step of preparing the second structure, the second light-transmissive member has a thickness smaller than a thickness of the light diffusing member. [Section 14] Item 14. The method for manufacturing a light emitting device according to any one of items 11 to 13, wherein a surface roughness of the first structure, of the first light-transmissive member, facing the second structure, is smaller than a surface roughness of the second structure, of the second light-transmissive member, facing the first structure. [Section 15] In the step of forming the third structure, After the first structure and the second structure are stacked, a pressing force is applied to the first structure and the second structure; Item 15. The method for manufacturing a light emitting device according to any one of items 11 to 14, wherein the range in which the pressing force acts expands from the center of the first structure and the second structure toward the outer periphery when viewed from above. [Section 16] Item 16. The method for manufacturing a light emitting device according to any one of items 11 to 15, wherein in the step of singulating the third structure into a plurality of the light emitting devices, the third structure is cut at the position of a lower end of the first convex portion. [Section 17] In the step of preparing the second structure, the upper surface of the second light-transmissive member has a flat portion parallel to the upper surface of the light-emitting element between adjacent first convex portions, Item 16. The method for manufacturing a light emitting device according to any one of items 11 to 15, wherein in the step of dividing the third structure into a plurality of the light emitting devices, the third structure is cut at the position of the flat portion.

[0121] The embodiments of the present disclosure have been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. All forms that can be implemented by a person skilled in the art through appropriate design modifications based on the above-described embodiments of the present disclosure also fall within the scope of the present disclosure, as long as they include the gist of the present disclosure. In addition, within the scope of the concept of the present disclosure, a person skilled in the art may come up with various modifications and alterations, and these modifications and alterations also fall within the scope of the present disclosure. [Explanation of symbols]

[0122] 11...light-emitting element, 12...electrode, 20...light-transmitting member, 21, 21a, 21b, 21c...first convex portion, 21A...central first convex portion, 21B...outer first convex portion, 21S...diagonal line of first convex portion, 22...first recessed portion, 23...flat portion, 30...light diffusing member, 31...third recessed portion, 32...second recessed portion, 33...flat portion, 40...light-reflective member, 100, 100A to 100D...light-emitting device, 121...first light-transmitting member, 122...second light-transmitting member, 200...first structure, 300...second structure, 501...upper mold, 502...lower mold, 503...release sheet, 504...transfer sheet, 504A...fourth convex portion, 600...third structure, 701...lower mold, 702...upper mold, 800...pressing mechanism

Claims

1. A light-emitting element; a light-transmitting member disposed on an upper surface and a side surface of the light-emitting element; a light diffusing member disposed on an upper surface of the light-transmitting member; Equipped with a side surface of the light-transmitting member is exposed from the light diffusing member; a distance between an upper surface of the light-emitting element and an upper surface of the light-transmitting member is longer than a distance between a side surface of the light-emitting element and a side surface of the light-transmitting member; an upper surface of the light-transmitting member has one or more first convex portions; The light emitting device, wherein the light diffusing member is in contact with a surface of one or more of the first convex portions.

2. The light emitting device according to claim 1 , wherein the thickness of the light diffusing member is greater than the thickness of the light transmissive member.

3. The light emitting device according to claim 1 , wherein the first convex portion has a curved surface.

4. The light emitting device according to claim 1 , wherein the first convex portion has a quadrangular pyramid shape.

5. the light-transmitting member has a rectangular shape in a top view, The light emitting device according to claim 4 , wherein the first protrusion has a rectangular shape that defines a quadrangular pyramid in a top view, and the rectangular side of the first protrusion is inclined or parallel to the rectangular side of the light-transmitting member.

6. The light emitting device according to claim 1 , wherein a center of the first convex portion and a center of the light emitting element overlap each other in a top view.

7. The light emitting device according to claim 1 , wherein the maximum width of the first convex portion is 1 / 20 to 1 / 5 of the width of the light-transmitting member in a cross-sectional view.

8. The light emitting device according to claim 1 , wherein the maximum height of the first convex portion is 0.5 to 2 times the maximum width of the first convex portion.

9. The light emitting device according to claim 1 , wherein the upper surface of the light diffusing member has second recesses at positions overlapping the first protrusions in a top view.

10. the upper surface of the light-transmitting member has a plurality of the first convex portions, the plurality of first convex portions include a central first convex portion located at the center of the upper surface of the light-transmitting member in a top view, and outer first convex portions located outside the central first convex portion, The light emitting device according to claim 1 , wherein the maximum height of the central first convex portion is greater than the maximum height of the outer first convex portion.

11. preparing a first structure having a plurality of light-emitting elements and a first light-transmissive member in a hardened state that covers upper and side surfaces of the light-emitting elements; preparing a second structure including an uncured second light-transmitting member and a cured light-diffusing member disposed on an upper surface of the second light-transmitting member, wherein the upper surface of the second light-transmitting member has one or more first convex portions, and the light-diffusing member is in contact with a surface of the one or more first convex portions; forming a third structure by stacking the first structure and the second structure such that the first light-transmissive member of the first structure and the second light-transmissive member of the second structure face each other and curing the second light-transmissive member; cutting the third structure at a position where the light emitting element is not arranged in a top view, and dividing the third structure into a plurality of light emitting devices; A method for manufacturing a light emitting device, comprising:

12. The step of preparing the second structure includes: forming a plurality of third recesses and / or third protrusions on the lower surface of the uncured light diffusing member using a mold; curing the light diffusing member; placing the second light-transmitting member in an uncured state on the lower surface of the light diffusing member; The method for manufacturing a light emitting device according to claim 11 , comprising:

13. 13. The method for manufacturing a light emitting device according to claim 11, wherein in the step of preparing the second structure, a thickness of the second light-transmissive member is thinner than a thickness of the light diffusing member.

14. 13. The method for manufacturing a light-emitting device according to claim 11, wherein a surface roughness of the first structure, of the first light-transmissive member, that faces the second structure, is smaller than a surface roughness of the second structure, of the second light-transmissive member, that faces the first structure.

15. In the step of forming the third structure, applying a pressing force to the first structure and the second structure after the first structure and the second structure are overlapped; The method for manufacturing a light-emitting device according to claim 11 , wherein the pressing force acts over a range that expands from the center of the first structure and the second structure toward the outer periphery in a top view.

16. The method for manufacturing a light-emitting device according to claim 11 , wherein in the step of dividing the third structure into the plurality of light-emitting devices, the third structure is cut at the position of a lower end of the first convex portion.

17. In the step of preparing the second structure, the upper surface of the second light-transmitting member has a flat portion parallel to the upper surface of the light-emitting element between adjacent first convex portions, The method for manufacturing a light-emitting device according to claim 11 , wherein in the step of dividing the third structure into the plurality of light-emitting devices, the third structure is cut at the position of the flat portion.

Images