Light-emitting device and method for manufacturing the same

Abstract

To provide a light-emitting device and a manufacturing method thereof that can reduce color unevenness.SOLUTION: A light-emitting device 100 includes a light emitting element 10 having a first surface 10a, a second surface 10b, and a side surface 10c, a wavelength conversion member 20 having at least a first lower surface 20a, an upper surface 20b, a first side surface 20c, a second side surface 20d, and a second lower surface 20e, and a light guide member 30, and in a plan view, the outer edge of the upper surface 20b of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light emitting element 10, and the light guide member 30 is arranged continuously on the side surface 10c of the light emitting element 10, the first side surface 20c of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20.SELECTED DRAWING: Figure 1D

Description

[Technical Field]

[0001] This disclosure relates to a light-emitting device and a method for manufacturing the same. [Background technology]

[0002] Light-emitting devices are known that include a wavelength conversion member on the upper surface of a light-emitting element and a light guide member on the side surface of the light-emitting element. For example, Patent Document 1 discloses a light-emitting device in which an uncured transparent material is placed on the upper surface of a light-emitting element, a plate-shaped optical layer is placed on the transparent material, the light-emitting element and the plate-shaped optical layer are superimposed, and then a fillet in contact with the side surface of the light-emitting element is formed to cure the transparent material. For such light-emitting devices, there is a need to further reduce color unevenness in the emission observation direction. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2012-004303 [Overview of the project] [Problems that the invention aims to solve]

[0004] The object of this disclosure is to provide a light-emitting device and a method for manufacturing the same that can reduce color unevenness. [Means for solving the problem]

[0005] The light-emitting device according to an embodiment of the present disclosure includes a light-emitting element having a first surface serving as a light extraction surface, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface, a wavelength conversion member disposed on the first surface of the light-emitting element, and a light guide member that guides light of the light-emitting element. The wavelength conversion member has at least a first lower surface facing the first surface of the light-emitting element, an upper surface opposite to the first lower surface and having an area larger than that of the first lower surface, a first side surface connected to the first lower surface, a second side surface connected to the upper surface and located outside the first side surface, and a second lower surface connecting the first side surface and the second side surface. In a plan view, an outer edge of the upper surface of the wavelength conversion member is located outside an outer edge of the first surface of the light-emitting element, and the light guide member is continuously disposed on the side surface of the light-emitting element, the first side surface of the wavelength conversion member, and the second side surface of the wavelength conversion member.

[0006] A method for manufacturing a light-emitting device according to an embodiment of the present disclosure includes a step of preparing a light-emitting element having a first surface serving as a light extraction surface, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface, and a wavelength conversion member having at least a first lower surface facing the first surface of the light-emitting element, an upper surface opposite to the first lower surface and having an area larger than that of the first lower surface, a first side surface connected to the first lower surface, a second side surface connected to the upper surface and located outside the first side surface, and a second lower surface connecting the first side surface and the second side surface; a step of disposing the light-emitting element on the first lower surface of the wavelength conversion member so that the first surface of the light-emitting element faces the first lower surface; and a step of disposing a light guide member continuously on the side surface of the light-emitting element, the first side surface of the wavelength conversion member, and the second side surface of the wavelength conversion member. The step of preparing includes preparing the wavelength conversion member having a size such that an outer edge of the upper surface of the wavelength conversion member is located outside an outer edge of the first surface of the light-emitting element in a plan view.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to provide a light-emitting device capable of reducing color unevenness and a method for manufacturing the same.

Brief Description of the Drawings

[0008] [Figure 1A] It is a perspective view schematically showing the whole light-emitting device according to the first embodiment. [Figure 1B] It is a plan view schematically showing the whole light-emitting device according to the first embodiment. [Figure 1C] It is a cross-sectional view taken along the IC-IC line in FIG. 1B. [Figure 1D] It is an enlarged cross-sectional view obtained by enlarging a part of FIG. 1C. [Figure 2A] It is a cross-sectional view illustrating a first modification example of the light guide member. [Figure 2B] It is a cross-sectional view illustrating a second modification example of the light guide member. [Figure 3] It is a flowchart showing a manufacturing method of the light-emitting device according to the first embodiment. [Figure 4A] It is a cross-sectional view schematically showing a step of preparing a wavelength conversion member in the manufacturing method of the light-emitting device according to the first embodiment. [Figure 4B] It is a cross-sectional view schematically showing a step of preparing a wavelength conversion member in the manufacturing method of the light-emitting device according to the first embodiment. [Figure 4C] It is a cross-sectional view schematically showing a step of preparing a wavelength conversion member in the manufacturing method of the light-emitting device according to the first embodiment. [Figure 5A] In the manufacturing method of the light-emitting device according to the first embodiment, it is a cross-sectional view schematically showing a state where a wavelength conversion member is disposed on a support member. [Figure 5B] In the manufacturing method of the light-emitting device according to the first embodiment, it is a cross-sectional view schematically showing a state where a light-emitting element is disposed on a first lower surface of the wavelength conversion member. [Figure 5C] In the manufacturing method of the light-emitting device according to the first embodiment, it is a cross-sectional view schematically showing a state where a light guide member is disposed on a side surface of the light-emitting element and a side surface of the wavelength conversion member. [Figure 5D] In the manufacturing method of the light-emitting device according to the first embodiment, it is a cross-sectional view schematically showing a state where a light reflection member covering the light-emitting element is formed. [Figure 5E]This is a schematic cross-sectional view showing a state in which the electrodes of the light-emitting element are exposed from the light-reflecting member in a method for manufacturing a light-emitting device according to the first embodiment. [Figure 5F] This is a schematic cross-sectional view showing a state in which a conductive member is placed on the electrode of a light-emitting element in a method for manufacturing a light-emitting device according to the first embodiment. [Figure 6A] This is a schematic plan view showing the entire light-emitting device according to the second embodiment. [Figure 6B] Figure 6A is a cross-sectional view along the VIB-VIB line. [Figure 6C] This is an enlarged cross-sectional view, showing a portion of Figure 6B. [Figure 7A] This is a schematic perspective view showing the entire light-emitting device according to the third embodiment. [Figure 7B] Figure 7A is a cross-sectional view along the VIIB-VIIB line. [Figure 8A] This is a cross-sectional view illustrating the distance (optical path length) over which light from a light-emitting element passes through a wavelength conversion member in a light-emitting device. [Figure 8B] This is a graph showing the directional characteristics of a light-emitting device. [Figure 9A] This is a cross-sectional view illustrating the distance (optical path length) over which light from a light-emitting element passes through a wavelength conversion member in a light-emitting device according to the first embodiment. [Figure 9B] This is a graph showing the directional characteristics of the light-emitting device according to the first embodiment. [Modes for carrying out the invention]

[0009] The light-emitting device and its manufacturing method will be described below with reference to the drawings. However, the embodiments shown below are illustrative examples of the light-emitting device and its manufacturing method for realizing the technical concept related to this disclosure, and are not limited to those described below. Furthermore, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this disclosure are merely illustrative and not intended to limit the scope of the present invention unless otherwise specified. Note that the size and positional relationships of the members shown in each drawing may be exaggerated or simplified for clarity of explanation. Also, "covering" is not limited to direct contact, but also includes indirect covering, for example, through other members. Similarly, "arranging" is not limited to direct contact, but also includes indirect arrangement, for example, through other members.

[0010] <First Embodiment> [Light-emitting device] A light-emitting device 100 according to an embodiment will be described with reference to Figures 1A to 1D. Figure 1A is a schematic perspective view showing the entire light-emitting device according to the first embodiment. Figure 1B is a schematic plan view showing the entire light-emitting device according to the first embodiment. Figure 1C is a cross-sectional view along the IC-IC line in Figure 1B. Figure 1D is an enlarged cross-sectional view showing a part of Figure 1C.

[0011] The light-emitting device 100 includes a light-emitting element 10 having a first surface 10a which serves as a light extraction surface, a second surface 10b which is opposite to the first surface 10a, and a side surface 10c which connects the first surface 10a and the second surface 10b; a wavelength conversion member 20 which is positioned on the first surface 10a of the light-emitting element 10; and a light-guiding member 30 which guides the light from the light-emitting element 10. The wavelength conversion member 20 has at least a first lower surface 20a facing the first surface 10a of the light-emitting element 10, an upper surface 20b on the opposite side of the first lower surface 20a and having a larger area than the first lower surface 20a, a first side surface 20c connected to the first lower surface 20a, a second side surface 20d connected to the upper surface 20b and located outside the first side surface 20c, and a second lower surface 20e connecting the first side surface 20c and the second side surface 20d. In a plan view, the outer edge of the upper surface 20b of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light-emitting element 10, and the light guide member 30 is continuously arranged on the side surface 10c of the light-emitting element 10, the first side surface 20c of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20.

[0012] In a plan view, the outer edge of the first lower surface 20a of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light-emitting element 10, and the light guide member 30 is continuously arranged on the side surface 10c of the light-emitting element 10, the first lower surface 20a of the wavelength conversion member 20, the first side surface 20c of the wavelength conversion member 20, the second lower surface 20e of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20. As an example, the light-emitting device 100 will be described as further comprising a light-reflecting member 40 covering the side surface of the light-guiding member 30 and a conductive member 50 arranged on the element electrode 90 of the light-emitting element 10. The various components of the light-emitting device 100 will be described below.

[0013] (light-emitting element) The light-emitting element 10 is formed, for example, in a rectangular parallelepiped shape by a first surface 10a which serves as the light extraction surface, a second surface 10b which serves as the bottom surface (back surface) opposite to the first surface 10a, and a side surface 10c which serves as the surface connecting the first surface 10a and the second surface 10b, and the element electrode 90 is provided on the second surface 10b. The light-emitting element 10 comprises a semiconductor structure. The semiconductor structure includes an n-side semiconductor layer, a p-side semiconductor layer, and an active layer sandwiched between the n-side semiconductor layer and the p-side semiconductor layer. The active layer may be 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 semiconductor is In x Al y Ga 1-x-y The semiconductor comprises all compositions in which the composition ratios x and y are varied within their respective ranges in the chemical formula N (0 ≤ x, 0 ≤ y, x + y ≤ 1). The emission peak wavelength of the active layer can be appropriately selected depending on the purpose. The active layer is configured to emit, for example, visible light or ultraviolet light.

[0014] A semiconductor structure may include multiple light-emitting sections, each containing an n-side semiconductor layer, an active layer, and a p-side semiconductor layer. When a semiconductor structure includes multiple light-emitting sections, each light-emitting section may include well layers with different emission peak wavelengths, or well layers with the same emission peak wavelength. Note that "same emission peak wavelength" includes variations of 5 nm or less. The combination of emission peak wavelengths of the multiple light-emitting sections can be selected as appropriate. For example, when a semiconductor structure includes two light-emitting sections, possible combinations of light emitted by each section include blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light. For example, when a semiconductor structure includes three light-emitting sections, possible combinations of light emitted by each section include blue light, green light, and red light. Each light-emitting section may include one or more well layers with an emission peak wavelength different from that of the other well layers. The element electrodes 90 of the light-emitting element 10 consist of a first element electrode 91 and a second element electrode 92, which are arranged on the second surface 10b with a gap between them.

[0015] (Conductive material) The conductive member 50 is placed on the element electrode 90 and electrically connects the element electrode 90 of the light-emitting element 10 to the wiring of the mounting substrate on which the light-emitting device 100 is mounted, thereby creating electrical conductivity between the light-emitting element 10 and the mounting substrate. In this example, the conductive member 50 includes a first conductive member 51 placed on the first element electrode 91 and a second conductive member 52 placed on the second element electrode 92. Each of the first conductive member 51 and the second conductive member 52 is arranged to have an area equal to or greater than the area of ​​the first element electrode 91 and the second element electrode 92, respectively. The first conductive member 51 and the second conductive member 52 are arranged, for example, to form a flattened, substantially rectangular parallelepiped, with all four sides formed by flat vertical surfaces or curved surfaces. This conductive member 50 can be made of a conductive metal, such as Cu, Au, or alloys thereof. For example, the conductive member 50 is arranged such that its height h is in the range of 25 nm to 100 μm. Although the conductive member 50 is shown here as being located on the element electrode 90, it may also be located on the wiring of the mounting substrate instead.

[0016] (Wavelength conversion component) The wavelength conversion member 20 absorbs at least a portion of the light from the light-emitting element 10 and converts it to a different wavelength. The wavelength conversion member 20 includes, for example, a wavelength conversion material such as a phosphor or a quantum dot. The following describes the case in which a phosphor is used as the wavelength conversion material. As an example, the wavelength conversion member 20 is formed in the shape of a rectangle or a square in a plan view. The wavelength conversion member 20 has a first lower surface 20a facing the first surface 10a of the light-emitting element 10, an upper surface 20b opposite to the first lower surface 20a and having a larger area than the first lower surface 20a, a first side surface 20c connected to the first lower surface 20a, a second side surface 20d connected to the upper surface 20b and located outside the first side surface 20c, and a second lower surface 20e connecting the first side surface 20c and the second side surface 20d. That is, the wavelength conversion member 20 has a step at its outer edge and is formed in a convex shape that points downward toward the first surface 10a of the light-emitting element 10, and the first lower surface 20a, which is the upper surface of the convex part, is positioned to face the first surface 10a of the light-emitting element 10. Because the wavelength conversion member 20 is formed in a convex shape, it has a protrusion 21 that protrudes from the first side surface 20c in the outer peripheral direction of the light-emitting device 100. The protruding portion 21 is formed by the second lower surface 20e, the second side surface 20d, and a part of the upper surface 20b.

[0017] The first lower surface 20a of the wavelength conversion member 20 has a larger area than the first surface 10a of the light-emitting element 10. Also, the upper surface 20b of the wavelength conversion member 20 has a larger area than the first lower surface 20a. In other words, the wavelength conversion member 20 is positioned such that, in a plan view, the outer edge of the upper surface 20b of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light-emitting element 10, and the outer edge of the first lower surface 20a of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light-emitting element 10.

[0018] Preferably, the wavelength conversion member 20 has a first side surface 20c and a second side surface 20d arranged substantially parallel to each other, and a first lower surface 20a and a second lower surface 20e arranged substantially parallel to each other. With such a configuration, the light emitted from the first side surface 20c and the second side surface 20d of the wavelength conversion member 20 is more likely to be emitted in the same direction, and the light emitted from the first lower surface 20a and the second lower surface 20e of the wavelength conversion member 20 is also more likely to be emitted in the same direction. As a result, as will be described later, the difference in the distance (optical path length) that light from the light-emitting element 10 travels through the wavelength conversion member 20 between the light traveling from the top surface of the light-emitting element 10 toward the top surface of the wavelength conversion member 20 and the light traveling diagonally from the top surface of the light-emitting element 10 toward the side surface of the wavelength conversion member 20 is reduced, thereby reducing color unevenness of the light from the light-emitting device.

[0019] "Approximately parallel" does not mean strictly parallel, but rather means that a variation of ±5° from parallel is acceptable. Similarly, "approximately perpendicular" does not mean strictly perpendicular, but rather means that a variation of ±5° from perpendicular is acceptable. The first side surface 20c and the second side surface 20d of the wavelength conversion member 20 are approximately parallel, and the first lower surface 20a, the second lower surface 20e, and the upper surface 20b of the wavelength conversion member 20 are approximately parallel. Furthermore, the first side surface 20c of the wavelength conversion member 20 and the second side surface 20d of the wave are approximately perpendicular to the first lower surface 20a of the wavelength conversion member 20.

[0020] As shown in Figure 1D, it is preferable that the horizontal distance D1 of the second lower surface 20e is greater than the maximum values ​​of the heights H1 and H2 of the first side surface 20c and the second side surface 20d of the wavelength conversion member 20. With this configuration, as will be described later, the reflection of light from the light-emitting element 10 by the light-reflecting member 40 covering the side surface of the light-guiding member 30 is suppressed, so that the difference in the distance (optical path length) that light from the light-emitting element 10 travels through the wavelength conversion member 20 between light traveling from the top surface of the light-emitting element 10 toward the top surface of the wavelength conversion member 20 and light traveling diagonally from the top surface of the light-emitting element 10 toward the side surface of the wavelength conversion member 20 is reduced, and the color unevenness of the light from the light-emitting device can be reduced.

[0021] The height H1 of the first side surface 20c of the wavelength conversion member 20 refers to the distance perpendicular to the first bottom surface 20a from the point of contact between the first bottom surface 20a and the first side surface 20c of the wavelength conversion member 20 to the second bottom surface 20e of the wavelength conversion member 20 or its extension. The height H2 of the second side surface 20d of the wavelength conversion member 20 refers to the distance perpendicular to the first lower surface 20a from the point of contact between the second lower surface 20e and the second side surface 20d of the wavelength conversion member 20 to the upper surface 20b of the wavelength conversion member 20 or its extension. Furthermore, the maximum value of height H1 refers to the highest point on the first side surface 20c of the wavelength conversion member 20 around its entire circumference, and the maximum value of height H2 refers to the highest point on the second side surface 20d of the wavelength conversion member 20 around its entire circumference. The horizontal distance D1 of the second lower surface 20e of the wavelength conversion member 20 refers to the horizontal distance from the point of contact between the first side surface 20c and the second lower surface 20e of the wavelength conversion member 20 to the second side surface 20d of the wavelength conversion member 20 or its extension, relative to the first lower surface 20a. For example, it is the horizontal distance from the outer edge of the first lower surface 20a of the wavelength conversion member 20 to the outer edge of the upper surface 20b of the wavelength conversion member 20 in a plan view.

[0022] As shown in Figure 1B, in a plan view, the horizontal distance D2 from the outer edge of the first surface 10a of the light-emitting element 10 to the outer edge of the first lower surface 20a of the wavelength conversion member 20 is preferably 25 μm or more and 200 μm or less. If the horizontal distance D2 is 25 μm or more, the type and amount of phosphor contained in the wavelength conversion member 20 can be increased to increase the luminous flux of the light-emitting device and to widen the range of chromaticity in which light can be emitted. The horizontal distance D2 is more preferably 50 μm or more. On the other hand, if the horizontal distance D2 is 200 μm or less, the light-emitting device 100 can be miniaturized. The horizontal distance D2 is more preferably 150 μm or less. Note that horizontal means approximately parallel to the first lower surface 20a.

[0023] In a plan view, the horizontal distance D3 from the outer edge of the first lower surface 20a of the wavelength conversion member 20 to the outer edge of the upper surface 20b of the wavelength conversion member 20 is preferably 25 μm or more and 200 μm or less. If the horizontal distance D3 is 25 μm or more, the type and amount of phosphor contained in the wavelength conversion member 20 can be increased to increase the luminous flux of the light-emitting device or to widen the range of chromaticity in which light can be emitted. The horizontal distance D3 is more preferably 50 μm or more. On the other hand, if the horizontal distance D3 is 200 μm or less, the light-emitting device 100 can be miniaturized. The horizontal distance D3 is more preferably 150 μm or less.

[0024] As shown in Figure 1D, the vertical thickness T1 from the first lower surface 20a to the upper surface 20b of the wavelength conversion member 20 is preferably 25 μm or more and 400 μm or less at its thickest point. If the thickness T1 is 25 μm or more, it becomes easier to increase the amount of phosphor and widen the chromaticity range of the emission. The thickness T1 is more preferably 100 μm or more. On the other hand, if the thickness T1 is 400 μm or less, the light-emitting device 100 can be made thinner. The thickness T1 is more preferably 300 μm or less.

[0025] The vertical thickness T1 of the wavelength conversion member 20 from the first lower surface 20a to the upper surface 20b is greater than the vertical thickness T2 of the wavelength conversion member 20 from the second lower surface 20e to the upper surface 20b. More specifically, it is preferable that the difference between thickness T1 and thickness T2 is 25 μm or more and 200 μm or less. If the difference between thickness T1 and thickness T2 is within this range, the balance between thickness T1 and thickness T2 becomes more appropriate, making it easier to manufacture the wavelength conversion member 20. It also makes it easier to adjust the shape of the light guide member 30. Furthermore, it is preferable that the vertical thickness T2 of the wavelength conversion member 20 from the second lower surface 20e to the upper surface 20b is 20 μm or more and 395 μm or less at its thickest point. If the thickness T2 is 20 μm or more, it becomes easier to increase the amount of phosphor and widen the chromaticity range of the emission. More preferably, the thickness T2 is 50 μm or more. On the other hand, if the thickness T2 is 395 μm or less, the light-emitting device 100 can be made thinner. In addition, heat dissipation can be improved. More preferably, it is 300 μm or less.

[0026] The wavelength conversion member 20 can contain only a phosphor, or it can be molded by mixing the phosphor with a translucent material such as resin, glass, or inorganic material as a binder. Examples of binders include epoxy resin, silicone resin, phenolic resin, polyimide resin, and glass. As the phosphor, for example, a yttrium-aluminum-garnet phosphor (YAG phosphor) can be used. When the light-emitting device 100 is capable of emitting white light, the concentration of the phosphor contained in the wavelength conversion member 20 is adjusted so that it can emit white light. When a binder is used, the concentration of the phosphor is preferably about 5% to 50%.

[0027] Furthermore, the light-emitting device 100 can not only emit white light, but can also emit incandescent-colored light by using a blue light-emitting element in the light-emitting element 10 and using, for example, a YAG-based phosphor and a nitride-based phosphor with a high red component as the phosphor.

[0028] The YAG-based phosphor contains Y and Al and is a phosphor activated with at least one element selected from rare earth elements, and emits light when excited by the light emitted from the light-emitting element 10. As the YAG-based phosphor, for example, (Re 1-x Sm x )3(Al 1-y Ga y )5O 12 :Ce (0≦x<1, 0≦y≦1, provided that Re is at least one element selected from the group consisting of Y, Gd, and La) etc. can be used.

[0029] [[ID=1④]]In addition, the nitride-based phosphor is a phosphor containing at least one or more rare earth elements selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Lu, at least one or more Group II elements selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn, at least one or more Group IV elements selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf, and N. Note that O may be included in the composition of this nitride phosphor. The nitride-based phosphor preferably contains at least one selected from the group consisting of a first nitride phosphor having a composition represented by the following formula (1A) and a second nitride phosphor having a composition represented by the following formula (1B). M 1 2Si5N8:Eu (1A) (In formula (1A), M 1 is an alkaline earth metal element containing at least one selected from the group consisting of Ca, Sr, and Ba.) Sr q Ca s ​​​​​​​​​​​​​​In the formula representing the composition of the phosphor, the part before the colon (:) represents the molar ratio of each element in 1 mole of the host crystal and the composition of the phosphor, and the part after the colon (:) represents the activating element. The phosphor preferably contains at least one selected from the group consisting of a first fluoride phosphor represented by the following formula (1C) and a second fluoride phosphor having a composition represented by the following formula (1C') different in composition from the formula (1C). A c [M 2 1-b Mn 4+ b F d (1C) (In the formula (1C), A includes at least one selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4 + , and among them, K + is preferable. M 2 includes at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and among them, Si and Ge are preferable. b satisfies 0 < b < 0.2, and c is the absolute value of the charge of the [M 2 1-b Mn 4+ b F d ion, and d satisfies 5 < d < 7.) A’ c’ [M 2 ’ 1-b’ Mn 4+ b’ F d’ (1C’) (In the formula (1C’), A’ includes at least one selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4 + , and among them, K + is preferable. M <00' contains at least one element selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements, among which Si and Al are preferred. b' satisfies 0 < b' < 0.2, c' is 2 ' 1-b’ Mn 4+ b’ F d’ the absolute value of the charge of the ion, and d' satisfies 5 < d' < 7. )

[0031] Although the example in which the wavelength conversion member 20 is composed of a single layer containing a phosphor has been shown, two or more single layers may be stacked. For example, as disclosed in JP-A-2018-172628, a sintered body containing a YAG-based phosphor can also be used as the wavelength conversion member 20. Further, a light diffusing substance may be added to the wavelength conversion member 20 as necessary. When the phosphor concentration of the wavelength conversion member 20 is increased, color unevenness is likely to occur, but by including a light diffusing substance in the wavelength conversion member 20, color unevenness and further luminance unevenness can be suppressed. As the light diffusing substance, for example, titanium oxide, barium titanate, aluminum oxide, silicon oxide, etc. can be used.

[0032] (Light guide member) The light guide member 30 is a member that guides light from the light emitting element 10 to the outside of the light emitting device 100. As the light guide member 30, it is preferable to use a translucent material that can effectively guide the light emitted from the light emitting element 10 to the wavelength conversion member 20 and can optically connect the light emitting element 10 and the wavelength conversion member 20. As the translucent material, for example, epoxy resin, silicone resin, phenol resin, polyimide resin, etc. can be used, and it is preferable to use silicone resin.

[0033] As an example, the light guide member 30 includes a first fillet 31 disposed on the side surface 10c of the light emitting element 10 and the first lower surface 20a of the wavelength conversion member 20, a second fillet 32 disposed on the first side surface 20c and the second lower surface 20e of the wavelength conversion member 20, and a third fillet 33 disposed on the second side surface 20d of the wavelength conversion member 20. The first fillet 31 and the second fillet 32 ​​are connected outside the corner formed by the first lower surface 20a and the first side surface 20c of the wavelength conversion member 20. The second fillet 32 ​​and the third fillet 33 are connected outside the corner formed by the second lower surface 20e and the second side surface 20d of the wavelength conversion member 20. In other words, the first fillet 31, the second fillet 32, and the third fillet 33 are continuous outside these corners. By positioning the light guide member 30 at these corner locations, the luminous flux can be improved. The first fillet 31 and the second fillet 32 ​​are separated by the dashed line A1 in Figure 1D, and the second fillet 32 ​​and the third fillet 33 are separated by the dashed line A2 in Figure 1D. The dashed lines A1 and A2 are lines that bisect the aforementioned corner, and in this case, they are lines at a 45° angle to the first lower surface 20a and the second lower surface 20e of the wavelength conversion member 20, respectively. By separating the first fillet 31 to the third fillet 33, it becomes easier to adjust the inclination angle of the side surface for each fillet, thereby improving the light extraction efficiency.

[0034] The first fillet 31, the second fillet 32, and the third fillet 33 have a shape in which their sides (outer surfaces) are inclined such that, in a cross-sectional view, their width widens from the second surface 10b side of the light-emitting element 10 toward the upper surface 20b side of the wavelength conversion member 20. Specifically, it is preferable that at least one of the first fillet 31 to the third fillet 33 is formed in a substantially triangular shape in a cross-sectional view. With this shape, light traveling laterally from the light-emitting element 10 is more easily reflected upward, thereby further improving the light extraction efficiency.

[0035] The term "approximately triangular" is not limited to triangles in the strict sense, but includes shapes that are visually recognizable as being close to a triangle. For example, it includes shapes where one or more of the three sides are curved rather than straight. It also includes shapes where one or more of the three corners of the triangle are not acute or obtuse, but are arc-shaped. As mentioned above, since the light guide member 30 is positioned at the corner of the wavelength conversion member 20, this part does not form a triangle in the fillet. However, such shapes are also included in the definition of an approximate triangle.

[0036] The cross-sectional shapes of the sides of the first fillet 31, the second fillet 32, and the third fillet 33 may be straight or curved. For example, if the sides of the first fillet 31, the second fillet 32, and the third fillet 33 in cross-sectional view are curved, the curved shape may be a curved shape that is recessed towards the light reflecting member 40, or a curved shape that is recessed towards the light-emitting element 10.

[0037] The upper surface 30a of the third fillet 33 (the upper surface 30a of the light guide member 30) is preferably flush with the upper surface 20b of the wavelength conversion member 20. With this configuration, the direction of the light emitted from the upper surface of the light-emitting device 100 can be made more uniform, and color unevenness can be reduced. Furthermore, "being flush" means that the upper surfaces of each component are located in approximately the same plane within an angle range of ±5°.

[0038] The light guide member 30 preferably contains a wavelength-converting material. The inclusion of a wavelength-converting material in the light guide member 30 reduces the difference in color uniformity between light emitted via the wavelength-converting member 20 (without passing through the light guide member 30) and light emitted via the light guide member 30, and also contributes to improving the luminous flux. Examples of wavelength-converting materials include phosphors.

[0039] (Light-reflecting material) The light-reflecting member 40 is positioned to cover the side surface of the light-guiding member 30. Furthermore, the light-reflecting member 40 is positioned to expose the upper surface 20b of the wavelength-converting member 20 and the upper surface 30a of the light-guiding member 30. This light-reflecting member 40 is intended to reflect light from the light-emitting element 10. The light-reflecting member 40 allows light emitted from the light-emitting element 10 to be incident on the wavelength-converting member 20. More specifically, the light-reflecting member 40 is positioned on the side surfaces of the first fillet 31, the second fillet 32, and the third fillet 33, as well as on the second surface 10b of the light-emitting element 10, the side surface of the first element electrode 91, and the side surface of the second element electrode 92.

[0040] As the light-reflecting member 40, an insulating material is preferably used, or a thermosetting resin, thermoplastic resin, etc., can be used to ensure a certain degree of strength. The light-reflecting member 40 can be formed using a resin or hybrid resin containing one or more of the following: silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, phenolic resin, bismaleimidotriazine resin, polyphthalamide resin, and a light-reflecting material. Among these, a resin containing silicone resin as a base polymer, which has excellent heat resistance, electrical insulation properties, and flexibility, is preferred. Examples of light-reflecting materials include titanium dioxide, silicon dioxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium hydroxide, calcium silicate, zinc oxide, barium titanate, potassium titanate, alumina, aluminum nitride, boron nitride, mullite, etc. Among these, titanium dioxide is preferred because it is relatively stable to moisture and has a high refractive index.

[0041] [Operation of the light-emitting device] When the light-emitting device 100 is driven, current is supplied to the light-emitting element 10 from an external power source, causing the light-emitting element 10 to emit light. Light traveling upward from the light-emitting element 10 has its wavelength converted by the wavelength conversion member 20 and is emitted to the outside as, for example, white light. Light traveling laterally from the light-emitting element 10 is emitted to the outside via the light guide member 30. The wavelength conversion member 20 has a stepped shape formed by having a first side surface 20c and a second bottom surface 20e, and the light guide member 30 covers the first side surface 20c and the second side surface 20d of the wavelength conversion member 20. Therefore, as will be described later, the difference in the distance (optical path length) that light from the light-emitting element 10 travels through the wavelength conversion member 20 is reduced between light traveling from the top surface of the light-emitting element 10 towards the top surface of the wavelength conversion member 20 and light traveling diagonally from the top surface of the light-emitting element 10 towards the side surface of the wavelength conversion member 20. As a result, the light from the light-emitting device has less color unevenness.

[0042] [Differentiation] Next, modified examples of the light guide member 30 will be described with reference to Figures 2A and 2B. Figures 2A and 2B are cross-sectional views showing modified example 1 and modified example 2 of the state of the light guide member of the light-emitting device according to the first embodiment, respectively. Components that have already been described are denoted by the same reference numerals and their description is omitted.

[0043] [Example 1] The light guide member 30A of the modified example 1 further includes a fourth fillet 34a positioned on the periphery of the second surface 10b of the light-emitting element 10. In other words, the light guide member 30A includes a first fillet 31, a second fillet 32, a third fillet 33, and a fourth fillet 34a. This improves the wettability (adhesion) of the resin contained in the light-reflecting member 40. This is because the wettability of the light guide member 30A and the resin forming the light-reflecting member 40 is better than the wettability of the second surface 10b of the light-emitting element 10, which is mainly made of semiconductor material, because they are made of the same resin material. Therefore, for example, the presence of the fourth fillet 34a reduces the risk of defects such as voids occurring in the resin of the light-reflecting member 40, which would reduce the reflection efficiency of the light-reflecting member 40. In addition, it makes it easier to position the light guide member 30A.

[0044] The first fillet 31 and the fourth fillet 34a are connected on the outside of the corner formed by the side surface 10c and the second surface 10b of the light-emitting element 10. By positioning the light guide member 30A at this corner, the light from the light-emitting element 10 can be guided, thereby improving the luminous flux of the light-emitting device 100. The first fillet 31 and the fourth fillet 34a are separated by the dashed line A3 in Figure 2A. The dashed line A3 is a line that bisects the aforementioned corner, and in this case, it is a line at a 45° angle to the second surface 10b of the light-emitting element 10. The fourth fillet 34a is positioned to cover a portion of one side of the element electrode 90. This fourth fillet 34a is positioned on a portion of the side of the element electrode 90 in three directions that are on the outer edge side of the light-emitting element 10. Specifically, the three sides of the first element electrode 91 and the three sides of the second element electrode 92. The fourth fillet 34a may be positioned so as not to cover the side of the element electrode 90.

[0045] [Differentiation 2] In the modified example 2, the light guide member 30B has a fourth fillet 34b positioned at the periphery of the second surface 10b of the light-emitting element 10 such that it covers one side of the element electrode 90 with the thickness of the element electrode 90. Otherwise, it is the same as in the modified example 1. With this configuration, the light reflecting member 40 does not come into contact with the second surface 10b of the light-emitting element 10 at the location where the fourth fillet 34b is present, and as described above, the wettability (adhesion) of the resin contained in the light reflecting member 40 is improved. In addition, the light guide member 30B is easier to position.

[0046] [Manufacturing method for light-emitting devices] Next, a method for manufacturing the light-emitting device according to the first embodiment will be described with reference to Figures 3 to 5F. Figures 1A to 1D will also be referenced as appropriate. Figure 3 is a flowchart showing a method for manufacturing a light-emitting device according to the first embodiment. Figures 4A to 4C are schematic cross-sectional views illustrating the process of preparing the wavelength conversion member. Figure 5A is a schematic cross-sectional view illustrating the state in which the wavelength conversion member is placed on the support member. Figure 5B is a schematic cross-sectional view illustrating the state in which a light-emitting element is placed on the first lower surface of the wavelength conversion member. Figure 5C is a schematic cross-sectional view illustrating the state in which light-guiding members are placed on the side surface of the light-emitting element and the side surface of the wavelength conversion member. Figure 5D is a schematic cross-sectional view illustrating the state in which a light-reflecting member covering the light-emitting element has been formed. Figure 5E is a schematic cross-sectional view illustrating the state in which the electrodes of the light-emitting element are exposed from the light-reflecting member. Figure 5F is a schematic cross-sectional view illustrating the state in which a conductive member is placed on the electrodes of the light-emitting element. Figures 4A to 5F schematically show the manufacturing process of one light-emitting device 100 when multiple light-emitting devices 100 are manufactured simultaneously.

[0047] A method for manufacturing the light-emitting device 100 includes a light-emitting element 10 having a first surface 10a which is a light extraction surface, a second surface 10b which is opposite to the first surface 10a, and a side surface 10c which connects the first surface 10a and the second surface 10b, and a first lower surface 20a facing the first surface 10a of the light-emitting element 10, an upper surface 20b which is opposite to the first lower surface 20a and has a larger area than the first lower surface 20a, a first side surface 20c which is connected to the first lower surface 20a, a second side surface 20d which is connected to the upper surface 20b and is located outside the first side surface 20c, and the first side surface 20c and the second side The process includes: preparing a wavelength conversion member 20 having at least a second lower surface 20e connecting to surface 20d (preparation step S11); arranging a light-emitting element 10 such that its first surface 10a faces the first lower surface 20a of the wavelength conversion member 20 (arranging light-emitting element step S12); and arranging a light-guiding member 30 so as to be continuous with the side surface 10c of the light-emitting element 10, the first side surface 20c of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20 (arranging light-guiding member step S13). Then, in preparation step S11, a wavelength conversion member 20 is prepared such that, in a plan view, the outer edge of the upper surface 20b of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light-emitting element 10.

[0048] In the manufacturing method of the light-emitting device 100, the preparation step S11 involves preparing a wavelength conversion member 20 such that, in a plan view, the outer edge of the first lower surface 20a of the wavelength conversion member 20 is located outside the outer edge of the first surface 10a of the light-emitting element 10. The light-guiding member placement step S13 involves placing the light-guiding member 30 continuously on the side surface 10c of the light-emitting element 10, the first lower surface 20a of the wavelength conversion member 20, the first side surface 20c of the wavelength conversion member 20, the second lower surface 20e of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20.

[0049] Furthermore, the manufacturing method of the light-emitting device 100 will be described as including the following steps after the step S13 of arranging the light-guiding member: arranging a light-reflecting member 40 to cover the side surface of the light-guiding member 30 (step S14 of arranging the light-reflecting member); arranging a conductive member 50 on the element electrode 90 after the step S14 of arranging the light-reflecting member (step S15 of arranging the conductive member); and framing the light-emitting device 100 into individual pieces after the step S15 of arranging the conductive member (step S16 of framing). The materials and arrangement of each component are as described in the above-mentioned description of the light-emitting device 100, so further explanation will be omitted here as appropriate.

[0050] (Preparation process) Preparation step S11 is the step of preparing a light-emitting element 10 having an element electrode 90 on the second surface 10b of the light-emitting element 10, and a wavelength conversion member 20. In preparation step S11, a wavelength conversion member 20 of a predetermined size and shape is prepared.

[0051] In preparation step S11, a wavelength conversion member 20 having a first side surface 20c and a second bottom surface 20e is prepared using two types of blades with different widths. Specifically, first, the wider blade is used to cut the plate-shaped wavelength conversion member 25 partway at a desired position to form a wavelength conversion member 26 with a recess 27. Next, the narrower blade is used to cut the remaining portion of the wavelength conversion member 26 at a desired position in the recess 27 to separate the wavelength conversion member 26 into individual pieces. In this way, a wavelength conversion member 20 of the desired size and shape is obtained. Rotary blades such as dicing saws or cutters such as die-cutting blades can be used for these blades.

[0052] (The process of arranging the light-emitting elements) Step S12 for arranging the light-emitting elements is the step of arranging the light-emitting elements 10 such that the first surface 10a of the light-emitting element 10 faces the first lower surface 20a of the wavelength conversion member 20. In step S12 for arranging the light-emitting elements, first, the wavelength conversion member 20 is placed on a support member 60, for example, a heat-resistant sheet, so that the upper surface 20b of the wavelength conversion member 20 faces the support member 60. Next, the light-emitting elements 10 are picked up and placed on the first lower surface 20a of each wavelength conversion member 20, for example, via an adhesive member, while pressing with a predetermined pressing force, and then dried.

[0053] (Step of arranging the light guide member) Step S13, which involves arranging the light guide member, is a step in which the light guide member 30 is arranged continuously on the side surface 10c of the light-emitting element 10, the first lower surface 20a of the wavelength conversion member 20, the first side surface 20c of the wavelength conversion member 20, the second lower surface 20e of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20. In step S13, which involves arranging the light guide member, an uncured resin that will become the light guide member 30 is applied to the side surface 10c of the light-emitting element 10, the first lower surface 20a, the first side surface 20c, the second lower surface 20e, and the second side surface 20d of the wavelength conversion member 20, for example, by potting or spraying. For example, an appropriate amount of resin is dropped to the desired position using a supply device equipped with a nozzle. If the light guide member 30 contains a wavelength conversion substance, the uncured resin may also contain a phosphor as the wavelength conversion substance. The resin is then cured to form the light guide member 30. Since the upper surface 20b of the wavelength conversion member 20 faces the support member 60, arranging the light guide member 30 on the support member 60 makes it easier to position the light guide member 30 so that its upper surface 30a is flush with the upper surface 20b of the wavelength conversion member 20.

[0054] (Step of arranging light-reflecting members) Step S14, which involves arranging the light-reflecting members, is a step in which light-reflecting members 40 cover the sides of the light-guiding members 30. In step S14, which involves arranging the light-reflecting member, first, uncured resin constituting the light-reflecting member 40 is arranged to cover the entire light-emitting element 10, including the element electrode 90, the entire wavelength conversion member 20, and the entire light-guiding member 30. The arrangement of the resin can be done, for example, by filling the resin using a resin dispensing device that can be moved (moved) vertically or horizontally relative to the support member 60, located above the fixed support member 60. It is also possible to arrange the resin by compression molding, transfer molding, etc. After that, the resin is cured to form the light-reflecting member 40. Next, a portion of the light-reflecting member 40 on the element electrode 90 side is removed so as to expose the element electrode 90 of the light-emitting element 10. The removal of the light-reflecting member 40 can be done, for example, by grinding, polishing, blasting, etc.

[0055] (Process of arranging conductive materials) Step S15, which involves arranging the conductive member, is the step of arranging the conductive member 50 on the element electrode 90. The conductive member 50 can be arranged by, for example, plating, screen printing, etc. After that, the assembly of the light-emitting device and the support member 60 are separated.

[0056] (The process of separating the pieces) Step S16, which involves separating the assembly of light-emitting devices into individual pieces, is a process that separates the assembly into individual pieces. In the fragmentation process S16, the light-reflecting member 40 is cut for each set of light-emitting element 10, wavelength conversion member 20, and conductive member 50, thereby fragmenting the assembly of light-emitting devices. Multiple light-emitting devices 100 are obtained by fragmenting the assembly.

[0057] <Second Embodiment> Next, the light-emitting device 100A according to the second embodiment will be described with reference to Figures 6A to 6C. Figure 6A is a schematic plan view showing the entire light-emitting device according to the second embodiment. Figure 6B is a cross-sectional view taken along the line VIB-VIB in Figure 6A. Figure 6C is an enlarged cross-sectional view showing a part of Figure 6B. Components that have already been described will be given the same reference numerals and their descriptions will be omitted as appropriate.

[0058] Compared to the configuration of the light-emitting device 100 of the first embodiment, the light-emitting device 100A has a configuration in which, in a plan view, the outer edge of the first lower surface 20a of the wavelength conversion member 20 is located at the outer edge of the first surface 10a of the light-emitting element 10. Furthermore, the light guide member 30C is arranged continuously on the side surface 10c of the light-emitting element 10, the first side surface 20c of the wavelength conversion member 20, the second lower surface 20e of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20. Specifically, in the light-emitting device 100A, the light guide member 30C is arranged continuously on the side surface of the light-emitting element 10 and the side surface of the wavelength conversion member 20 as a single fillet, without being distinguished as a first fillet, a second fillet, and a third fillet.

[0059] Furthermore, the light-emitting device 100A can be manufactured by performing steps S11 to S16 as described above. In this process, in preparation step S11, a wavelength conversion member 20 is prepared such that, in a plan view, the outer edge of the first lower surface 20a of the wavelength conversion member 20 is positioned at the outer edge of the first surface 10a of the light-emitting element 10. In step S13, where the light guide members are placed, the light guide members 30C are placed continuously on the side surface 10c of the light-emitting element 10, the first side surface 20c of the wavelength conversion member 20, the second lower surface 20e of the wavelength conversion member 20, and the second side surface 20d of the wavelength conversion member 20.

[0060] <Third Embodiment> Next, the light-emitting device 100B according to the third embodiment will be described with reference to Figures 7A and 7B. Figure 7A is a schematic perspective view showing the entire light-emitting device according to the third embodiment. Figure 7B is a cross-sectional view taken along the line VIIB-VIIB in Figure 7A. Components already described will be given the same reference numerals and their descriptions will be omitted as appropriate.

[0061] Compared to the configuration of the light-emitting device 100 of the first embodiment, the light-emitting device 100B has a lens 70 provided on the upper surface of the wavelength conversion member 20 facing the light-emitting element 10. The lens 70 will be described below. The lens 70 is positioned on the upper surface of the wavelength conversion member 20, the upper surface of the light guide member 30, and the upper surface of the light reflecting member 40. The lens 70 is formed as a hemispherical plano-convex lens with an upwardly convex curved surface. The lens 70 consists of a hemispherical convex lens portion 71 and a flat flange portion 72 connected to the lower end of the convex lens portion 71. The lens center of the lens 70 is positioned to align with the element center of the light-emitting element 10. The flange portion 72 is formed as a rectangle or square in plan view, is larger than the convex lens portion 71, and is sized to approximately match the shape of the light-emitting device 100B excluding the lens 70 in plan view. The lens 70 can concentrate and emit the mixed-color light from the light-emitting element 10 and the wavelength conversion member 20 through the convex lens portion 71 to the outside of the light-emitting device 100B.

[0062] Examples of materials for the lens 70 include weather-resistant translucent resins such as polycarbonate resin, acrylic resin, epoxy resin, urea resin, and silicone resin, as well as glass. The lens 70 is a translucent component or a transparent body. The lens 70 may contain fillers such as diffusers. By containing fillers in the lens 70, changes in light distribution can be reduced. Examples of fillers include barium titanate, titanium oxide, aluminum oxide, and silicon oxide. The lens 70 may contain a coloring agent. For example, by containing a blue coloring agent, a green coloring agent, or a red coloring agent, a light-emitting device 100B that emits blue light, a light-emitting device 100B that emits green light, and a light-emitting device 100B that emits red light can be made. By using these light-emitting devices 100B, a light source device capable of full-color display can be manufactured.

[0063] As colorants, for example, copper phthalocyanates, CI pigment green 36, and N,N'-dimethyl-3,4:9,10-perylene bisdicarboimide can be used. Alternatively, a colorant containing either a pigment or a dye may be used. While there are no particular limitations on the type of pigment, examples include those made from inorganic or organic materials. Ideally, the pigments and dyes should not convert the light from the light-emitting element 10 to a different wavelength, in order to avoid affecting the wavelength-converting material. Lens 70 may contain a light stabilizer. Examples of light stabilizers include benzotriazoles, benzophenones, salicylates, cyanoacrylates, and hindered amines.

[0064] Furthermore, in the manufacturing method of the light-emitting device 100B, the step of arranging the lens is performed after the step of arranging the light-reflecting member S14. The lens placement process involves placing a lens 70, which has an upwardly convex curved surface, on the upper surface of the wavelength conversion member 20. In this process, the lower surface of the flange portion 72 of the lens 70 is bonded to the upper surface of the wavelength conversion member 20, the upper surface of the light guide member 30, and the upper surface of the light reflecting member 40 via a translucent adhesive. After this process is completed, a piece-forming process S16 is performed, and the light-emitting device 100B is manufactured by cutting each lens 70 into individual pieces.

[0065] [Effects and Effects of Light-Emitting Devices] The effects of the light-emitting device will be explained using the light-emitting device 100 as an example, with reference to Figures 8A to 9B. Figure 8A is a cross-sectional view illustrating the distance (optical path length) that light from the light-emitting element passes through the wavelength conversion member in the light-emitting device 1000. Figure 8B is a graph showing the directional characteristics of the light-emitting device 1000. Figure 9A is a cross-sectional view illustrating the distance (optical path length) that light from the light-emitting element passes through the wavelength conversion member in the light-emitting device 100. Figure 9B is a graph showing the directional characteristics of the light-emitting device 100.

[0066] In the light-emitting device 1000, some of the light that travels diagonally from the top surface of the light-emitting element 10 towards the side of the wavelength conversion member 200 is reflected by the light-reflecting member 400 that covers the side of the light guide member 300, and this light passes through the wavelength conversion member 200, which can increase the distance (optical path length) that the light travels through the wavelength conversion member 20.

[0067] For example, as shown in Figure 8A, in the light-emitting device 1000, the light L1A traveling from the top surface of the light-emitting element 10 toward the top surface of the wavelength conversion member 200 has a short transmission distance through the wavelength conversion member 200, resulting in a stronger high color temperature (blue). On the other hand, the light L2A1 and L2A2 traveling diagonally from the top surface of the light-emitting element 10 toward the side surface of the wavelength conversion member 200 have a longer transmission distance through the wavelength conversion member 200 due to reflection by the light-reflecting member 40, resulting in a stronger low color temperature (yellow). In other words, in the light-emitting device 1000, the difference in the distance (optical path length) that the light from the light-emitting element 10 travels through the wavelength conversion member 200 is large between the light L1A traveling from the top surface of the light-emitting element 10 toward the top surface of the wavelength conversion member 200 and the light L2A1 and L2A2 traveling diagonally from the top surface of the light-emitting element 10 toward the side surface of the wavelength conversion member 200. Therefore, wavelength conversion by the phosphor is not performed to roughly the same degree for each emission observation direction, and this is thought to be one of the causes of color unevenness in the emission observation direction of light from the light emission device 1000.

[0068] Specifically, as shown in Figure 8B, in terms of directional characteristics, for example, the difference in correlated color temperature (Tcp) is large between light traveling upwards in directions around ±15° from 0° (central axis) in directional angle, and light traveling diagonally to the sides in directions around 60° to 90° and -60° to -90° in directional angle.

[0069] In contrast, the light-emitting device 100 has a wavelength conversion member 20, which is placed on top of a light-emitting element 10 that emits blue light and contains a phosphor that emits yellow light. The wavelength conversion member 20 is formed in a convex shape with a step at its outer edge, and the first lower surface 20a, which is the upper surface of the convex part, is positioned to face the first surface 10a of the light-emitting element 10. Furthermore, in the light-emitting device 100, the light guide member 30 covers from the side surface of the light-emitting element 10 to the side surface of the wavelength conversion member 20.

[0070] With such wavelength conversion member 20 and light guide member 30, for example as shown in Figure 9A, reflection by the light reflecting member 40 covering the side surface of the light guide member 30 is reduced. As a result, the difference in the distance (optical path length) that light from the light-emitting element 10 travels through the wavelength conversion member 20 is reduced between light L1B traveling from the top surface of the light-emitting element 10 towards the top surface of the wavelength conversion member 20 and light L2B1, L2B2 traveling diagonally from the top surface of the light-emitting element 10 towards the side surface of the wavelength conversion member 20. Therefore, wavelength conversion by the phosphor is performed to approximately the same extent for each emission observation direction, which reduces color unevenness in the emission observation direction of light from the light-emitting device 100.

[0071] Specifically, as shown in Figure 9B, in terms of directional characteristics, for example, the difference in correlated color temperature (Tcp) becomes smaller between light traveling upwards in directions around ±15° from 0° (central axis) in directional angle, and light traveling diagonally to the sides in directions around 60° to 90° and -60° to -90° in directional angle.

[0072] Similarly, in light-emitting devices 100A and 100B, the difference in the distance (optical path length) that light from the light-emitting element 10 travels through the wavelength conversion member 20 is reduced between the light traveling from the top surface of the light-emitting element 10 toward the top surface of the wavelength conversion member 20 and the light traveling diagonally from the top surface of the light-emitting element 10 toward the side surface of the wavelength conversion member 20. As a result, the light from the light-emitting element 10 has less color unevenness.

[0073] Although the embodiments for carrying out the invention have been described in more detail above, the spirit of the present invention is not limited to these descriptions and must be interpreted broadly based on the claims. Furthermore, various modifications and alterations based on these descriptions are also included in the spirit of the present invention. For example, the wavelength conversion member is given a shape with one step at its outer edge, but it may also be given a shape with two or more steps at its outer edge. Also, the connection between the first lower surface and the first side surface of the wavelength conversion member, and the connection between the second lower surface and the second side surface, are not limited to being at an angle where the horizontal and vertical lines intersect, but may be a rounded arc shape or a flat shape with chamfered corners. Furthermore, the connection between the second lower surface and the first side surface is not limited to being at an angle where the horizontal and vertical lines intersect, but may also be a rounded arc shape or a flat shape. In addition, the first fillet, second fillet, and third fillet are made continuous by being connected outside the corner of the wavelength conversion member, but they may not be continuous if the light guide member does not cover the corner. Also, the light-emitting element and the wavelength conversion member may be circular or other shapes in a plan view, in addition to being rectangular or square. [Industrial applicability]

[0074] The light-emitting device described herein can be used in various lighting fixtures, backlight sources for liquid crystal displays, indoor displays, and various display devices such as advertisements and destination signs. [Explanation of symbols]

[0075] 100, 100A light-emitting device 10 light-emitting elements 10a First surface (light extraction surface) 10b Second surface (back side of element) 10c side 20, 25, 26 wavelength conversion components 20a 1st bottom surface 20b Top surface 20c 1st side 20d 2nd side 20e 2nd bottom surface 21 Protrusion 27 recess 30, 30A, 30B, 30C Light guide members 31 First fillet 32 Second fillet 33 Third Fillet 34a, 34b Fourth fillet 30a top surface 40 Light-reflecting member 50 Conductive members 51 First conductive member 52 Second conductive member 60 Support member 70 lenses 71 Convex lens section 72 Guard section 90-element electrode 91 First Element Electrode 92 Second Element Electrode

Claims

1. A light-emitting element having a first surface that serves as a light extraction surface, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface, A wavelength conversion member is disposed on the first surface of the light-emitting element, It comprises a light guide member that guides the light of the light-emitting element, The wavelength conversion member has at least a first lower surface facing the first surface of the light-emitting element, an upper surface opposite the first lower surface and having a larger area than the first lower surface, a first side surface connected to the first lower surface, a second side surface connected to the upper surface and located outside the first side surface, and a second lower surface connecting the first side surface and the second side surface. In a plan view, the outer edge of the upper surface of the wavelength conversion member is located outside the outer edge of the first surface of the light-emitting element. The light guide member is arranged continuously on the side surface of the light-emitting element, the first side surface of the wavelength conversion member, and the second side surface of the wavelength conversion member, and in a cross-sectional view, the outer surface of the portion of the wavelength conversion member that is arranged on the first side surface is inclined such that the width of the portion arranged on the first side surface widens from the second side surface of the light-emitting element toward the upper side surface of the wavelength conversion member, and in a cross-sectional view, the outer surface of the portion of the wavelength conversion member that is arranged on the second side surface is inclined such that the width of the portion arranged on the second side widens from the second side surface of the light-emitting element toward the upper side surface of the wavelength conversion member, in a light-emitting device.

2. In a plan view, the outer edge of the first lower surface of the wavelength conversion member is located outside the outer edge of the first surface of the light-emitting element. The light-emitting device according to claim 1, wherein the light-guiding member is continuously arranged on the side surface of the light-emitting element, the first lower surface of the wavelength conversion member, the first side surface of the wavelength conversion member, the second lower surface of the wavelength conversion member, and the second side surface of the wavelength conversion member.

3. The light guide member comprises a portion disposed on the side surface of the light-emitting element and the first lower surface of the wavelength conversion member, and a portion disposed on the first side surface and the second lower surface of the wavelength conversion member. The light-emitting device according to claim 2, wherein the portion disposed on the side surface of the light-emitting element and the first lower surface of the wavelength conversion member, and the portion disposed on the first side surface and the second lower surface of the wavelength conversion member are connected outside the corner formed by the first lower surface and the first side surface of the wavelength conversion member.

4. The light guide member comprises a portion disposed on the first side surface and the second lower surface of the wavelength conversion member, and a portion disposed on the second side surface of the wavelength conversion member. The light-emitting device according to claim 2 or 3, wherein the portion disposed on the first side surface and the second lower surface of the wavelength conversion member, and the portion disposed on the second side surface of the wavelength conversion member, are connected outside the corner formed by the second lower surface and the second side surface of the wavelength conversion member.

5. The light-emitting device according to claim 4, wherein the upper surface of the portion disposed on the second side surface of the wavelength conversion member is flush with the upper surface of the wavelength conversion member.

6. In a plan view, the outer edge of the first lower surface of the wavelength conversion member is located at the outer edge of the first surface of the light-emitting element. The light-emitting device according to claim 1, wherein the light-guiding member is arranged continuously on the side surface of the light-emitting element, the first side surface of the wavelength conversion member, the second lower surface of the wavelength conversion member, and the second side surface of the wavelength conversion member.

7. The light-emitting device according to any one of claims 2 to 5, wherein, in a plan view, the horizontal distance from the outer edge of the first surface of the light-emitting element to the outer edge of the first lower surface of the wavelength conversion member is 25 μm or more and 200 μm or less.

8. The light-emitting device according to any one of claims 1 to 7, wherein, in a plan view, the horizontal distance from the outer edge of the first lower surface of the wavelength conversion member to the outer edge of the upper surface of the wavelength conversion member is 25 μm or more and 200 μm or less.

9. The light-emitting device according to any one of claims 1 to 8, wherein the vertical thickness of the wavelength conversion member from the first lower surface to the upper surface of the wavelength conversion member is 25 μm or more and 400 μm or less at its thickest point.

10. The light-emitting device according to any one of claims 1 to 9, wherein the vertical thickness from the first lower surface to the upper surface of the wavelength conversion member is greater than the vertical thickness from the second lower surface to the upper surface of the wavelength conversion member, and the vertical thickness from the second lower surface to the upper surface of the wavelength conversion member is 20 μm or more and 395 μm or less at its thickest point.

11. The light-emitting device according to any one of claims 1 to 10, wherein the first side surface of the wavelength conversion member and the second side surface of the wavelength conversion member are arranged substantially parallel to each other, and the first lower surface of the wavelength conversion member and the second lower surface of the wavelength conversion member are arranged substantially parallel to each other.

12. The light-emitting device according to any one of claims 1 to 11, wherein the horizontal distance of the second lower surface is greater than the maximum height of the first side surface and the second side surface of the wavelength conversion member.

13. The light-emitting device according to any one of claims 1 to 12, wherein the light-guiding member includes a wavelength-converting material.

14. The light-emitting device according to any one of claims 1 to 13, further comprising a light-reflecting member covering the side surface of the light-guiding member.

15. A light-emitting element having a first surface that serves as a light extraction surface, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface; and a wavelength conversion member having at least a first lower surface facing the first surface of the light-emitting element, an upper surface opposite to the first lower surface and having a larger area than the first lower surface, a first side surface connected to the first lower surface, a second side surface connected to the upper surface and located outside the first side surface, and a second lower surface connecting the first side surface and the second side surface; The steps include: arranging the light-emitting element on the first lower surface of the wavelength conversion member such that the first surface of the light-emitting element faces the first lower surface of the light-emitting element; The process includes arranging a light guide member so as to be continuous with the side surface of the light-emitting element, the first side surface of the wavelength conversion member, and the second side surface of the wavelength conversion member, The preparation step described above involves preparing a wavelength conversion member such that, in a plan view, the outer edge of the upper surface of the wavelength conversion member is located outside the outer edge of the first surface of the light-emitting element. A method for manufacturing a light-emitting device, wherein, in a cross-sectional view, the outer surface of the portion of the wavelength conversion member that is positioned on the first side surface of the light-guiding member is inclined such that the width of the portion positioned on the first side surface increases from the second side surface of the light-emitting element toward the upper side surface of the wavelength conversion member, and in a cross-sectional view, the outer surface of the portion of the wavelength conversion member that is positioned on the second side surface is inclined such that the width of the portion positioned on the second side surface increases from the second side surface of the light-emitting element toward the upper side surface of the wavelength conversion member.

16. The preparation step described above involves preparing a wavelength conversion member such that, in a plan view, the outer edge of the first lower surface of the wavelength conversion member is located outside the outer edge of the first surface of the light-emitting element. The method for manufacturing a light-emitting device according to claim 15, wherein the step of arranging the light guide member is to arrange the light guide member continuously on the side surface of the light-emitting element, the first lower surface of the wavelength conversion member, the first side surface of the wavelength conversion member, the second lower surface of the wavelength conversion member, and the second side surface of the wavelength conversion member.

17. The preparation step described above involves preparing a wavelength conversion member such that, in a plan view, the outer edge of the first lower surface of the wavelength conversion member is positioned at the outer edge of the first surface of the light-emitting element. The method for manufacturing a light-emitting device according to claim 15, wherein the step of arranging the light guide member is to arrange the light guide member continuously on the side surface of the light-emitting element, the first side surface of the wavelength conversion member, the second lower surface of the wavelength conversion member, and the second side surface of the wavelength conversion member.

18. A method for manufacturing a light-emitting device according to any one of claims 15 to 17, further comprising the step of arranging a light-reflecting member to cover the side surface of the light-guiding member after the step of arranging the light-guiding member.

19. A method for manufacturing a light-emitting device according to any one of claims 15 to 18, wherein in the step of arranging the light-guiding member, the light-guiding member includes a wavelength conversion material.

20. The method for manufacturing a light-emitting device according to any one of claims 15 to 19, wherein the step of arranging the light-guiding member is to arrange the light-guiding member such that the upper surface of the light-guiding member is flush with the upper surface of the wavelength conversion member.

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