Light-emitting device

Abstract

To simplify a structure of light-emitting devices with luminance distribution on a light-emitting surface.SOLUTION: A light-emitting device according to one embodiment of the present disclosure comprises: a substrate; a light-emitting element having a light-emitting layer placed on the top surface of the substrate; a translucent element without a light-emitting layer that is placed next to the light-emitting element on the top surface of the substrate; and a translucent member covering the top surface of the light-emitting element and the translucent element.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] As a light source for vehicle lamps, semiconductor light-emitting elements such as LEDs (Light Emitting Diodes) are used. Patent Document 1 discloses a light-emitting device including four semiconductor light-emitting elements arranged linearly, wherein the light-emitting area of the semiconductor light-emitting elements inside from both ends is made smaller than the light-emitting area of the semiconductor light-emitting elements at both ends, and the light-emitting surface has a luminance distribution.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to simplify the structure of a light-emitting device having a luminance distribution on a light-emitting surface.

Means for Solving the Problems

[0005] A light-emitting device according to an embodiment of the present disclosure includes a substrate, a light-emitting element disposed on an upper surface of the substrate and including a light-emitting layer, a light-transmissive element disposed adjacent to the light-emitting element on the upper surface of the substrate and not including a light-emitting layer, and a light-transmissive member covering upper surfaces of the light-emitting element and the light-transmissive element.

Effects of the Invention

[0006] According to an embodiment of the present disclosure, the structure of a light-emitting device having a luminance distribution on a light-emitting surface can be simplified.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0008] Hereinafter, with reference to the drawings, the light-emitting device according to the embodiment of the present disclosure will be described in detail. However, the embodiments shown below are examples of light-emitting devices for embodying the technical idea of the embodiments, and are not limited thereto. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to limit the scope of the present disclosure only thereto without specific description, but are merely illustrative examples. Note that the sizes and positional relationships of the members shown in each drawing may be exaggerated for clarity of explanation. In the following description, the same names and reference numerals indicate the same or similar members, and detailed descriptions will be omitted as appropriate. In some cases, an end view showing only the cut surface is used as a cross-sectional view.

[0009] In the figures shown below, the directions may be indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are mutually perpendicular directions. The direction in which the arrow points in the X-axis direction is denoted as the +X direction or the +X side, and the opposite direction of the +X direction is denoted as the -X direction or the -X side. The direction in which the arrow points in the Y-axis direction is denoted as the +Y direction or the +Y side, and the opposite direction of the +Y direction is denoted as the -Y direction or the -Y side. The direction in which the arrow points in the Z-axis direction is denoted as the +Z direction or the +Z side, and the opposite direction of the +Z direction is denoted as the -Z direction or the -Z side. Also, in the terms of the embodiments, the top view means looking at the object from the +Z direction. However, these do not limit the orientation of the light-emitting device during use, and the orientation of the light-emitting device is arbitrary. Also, in the embodiments, the surface in the +Z direction (i.e., the surface of the object when viewed from the +Z direction) is defined as the "upper surface", and the surface in the -Z direction (i.e., the surface of the object when viewed from the -Z direction) is defined as the "lower surface". In the embodiments shown below, along the X-axis, Y-axis, and Z-axis includes the case where the object has an inclination within the range of ±10° with respect to these axes. Also, in the embodiments, orthogonality may include an error within ±10° with respect to 90°.

[0010] Also, in the present disclosure, unless otherwise specified, with respect to polygons such as rectangles, those having shapes with processing such as rounding of corners, chamfering, corner cutting, and rounding at the corners of the polygon are also included in the term "polygon". Also, not limited to the corners (ends of the sides), those having shapes with processing in the middle part of the sides are also similarly referred to as "polygons". That is, shapes with partial processing while leaving the polygon as a base are included in the interpretation of the "polygon" described in the present disclosure.

[0011] Also, not limited to polygons, the same applies to terms representing specific shapes such as trapezoids, circles, and unevenness. Also, the same applies to terms regarding each side forming the shape. That is, even if there is processing at the corner or the middle part of a certain side, the processed part is included in the interpretation of the "side".

[0012] In addition, "covering" or "coating" is not limited to direct contact, but also includes cases where it covers indirectly, for example, via other members. Further, "arranging" is not limited to direct contact, but also includes cases where it arranges indirectly, for example, via other members.

[0013] [First Embodiment] <Overall Configuration Example of Light-Emitting Device 1> With reference to FIGS. 1 to 4, an example of the overall configuration of a light-emitting device 1 according to the first embodiment will be described. FIG. 1 is a schematic top view showing an example of the overall configuration of the light-emitting device 1 according to the first embodiment. FIG. 2 is a schematic partial cross-sectional view of the light-emitting device 1 according to the first embodiment cut along line II-II shown in FIG. 1. FIG. 3 is a schematic top view for explaining the substrate 10 of the light-emitting device 1 according to the first embodiment. FIG. 4 is a schematic partial cross-sectional view of the light-emitting device 1 including a light-transmissive member 40M of another example.

[0014] As shown in FIGS. 1 and 2, the light-emitting device 1 includes a substrate 10, a light-emitting element 20, a light-transmissive element 30, and a light-transmissive member 40. Further, the light-emitting device 1 may include a light guide member 50, a covering member 60, a light reflection film 70, and a conductive member 75. Furthermore, the light-emitting device 1 may include other constituent members such as electronic components mounted on the substrate 10. Examples of the electronic components mounted on the substrate 10 include protection elements such as Zener diodes and varistors, thermistors, capacitors, etc. However, the electronic components mounted on the substrate 10 are not limited thereto.

[0015] <Substrate 10> The configuration of the substrate 10 will be described. The substrate 10 is a plate-like member having a substantially rectangular shape in a top view. However, the substrate 10 may have other shapes such as a substantially circular shape, an elliptical shape, or a substantially polygonal shape in a top view.

[0016] As shown in FIGS. 1 and 2, the substrate 10 has an upper surface 10a, a lower surface 10b opposite to the upper surface 10a, and one or more side surfaces connecting the outer edges of the upper surface 10a and the lower surface 10b. The substrate 10 includes a base material 11 and wiring (upper surface wiring) 12 disposed on at least the upper surface of the base material 11. The wiring 12 may include wiring (lower surface wiring) disposed on the lower surface of the base material 11, wiring (inner layer wiring) disposed inside the base material 11, and the like.

[0017] The base material 11 corresponds to the base material of the substrate 10 and has a substantially rectangular shape in a top view. However, the base material 11 may have other shapes such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape in a top view. The base material 11 is preferably composed of a ceramic with excellent heat dissipation such as aluminum nitride, aluminum oxide, silicon carbide, or silicon nitride, or a resin with excellent heat dissipation such as glass epoxy. However, the material constituting the base material 11 is not limited to these.

[0018] The wiring 12 is electrically connected to an external power source. The wiring 12 is also connected to the light-emitting element 20. Electric power from the external power source is supplied to the light-emitting element 20 through the wiring 12. That is, the wiring 12 functions as a power supply terminal for supplying power to the light-emitting element 20. As an example, the wiring 12 includes a plurality of conductive portions provided separately on the upper surface 10a of the substrate 10.

[0019] A metal material can be used for the wiring 12. For example, a single metal such as gold (Au), silver (Ag), aluminum (Al), nickel (Ni), rhodium (Rh), copper (Cu), titanium (Ti), platinum (Pt), palladium (Pd), molybdenum (Mo), chromium (Cr), tungsten (W), or an alloy containing these metals can be preferably used. However, the material constituting the wiring 12 is not limited to these.

[0020] Specifically, as shown in FIG. 3, the wiring 12 includes a first wiring 121, a second wiring 122, and a third wiring 123. The second wiring 122 and the third wiring 123 may be a continuous single wiring, or may be electrically connected via a conductive member such as a wire 13. Further, when a conductive light reflecting film 70 is disposed on the lower surface 30b of the light transmissive element 30, the second wiring 122 and the third wiring 123 may be electrically connected via the light reflecting film 70. The first wiring 121 is connected to, for example, the p-side electrode 222 among the electrodes 22 included in the light emitting element 20. The third wiring 123 is connected to, for example, the n-side electrode 221 and the n-side electrode 223 among the electrodes 22 included in the light emitting element 20, respectively. One of the first wiring 121 and the second wiring 122 is connected to an external power source. In the example shown in FIG. 3, the second wiring 122 is connected to the external power source. However, the layout of the wiring 12 and the connection relationship with the electrodes 22 are not limited to these. Note that a protection element 28 such as a Zener diode may be electrically connected to the first wiring 121 and the second wiring 122.

[0021] <Light emitting element 20> Next, the configuration of the light emitting element 20 will be described. The light emitting element 20 is a semiconductor light emitting element such as an LED or an LD (Laser Diode). As shown in FIGS. 1 and 2, the light emitting element 20 is disposed on the upper surface 10a of the substrate 10. The light emitting element 20 has an upper surface 20a, a lower surface 20b, and one or more side surfaces connecting the upper surface 20a and the lower surface 20b. The light emitting element 20 is disposed adjacent to the light transmissive element 30 on the upper surface 10a of the substrate 10. Among the one or more side surfaces of the light emitting element 20, the side surface facing the light transmissive element 30 is hereinafter referred to as the "side surface 20c".

[0022] The light emitting element 20 is a plate-like member having a substantially rectangular shape in a top view. The light emitting element 20 shown in FIGS. 1 and 2 has a substantially rectangular shape in a top view. However, the light emitting element 20 may have other shapes such as a substantially square shape or a substantially polygonal shape in a top view.

[0023] The light-emitting element 20 shown in Fig. 1 and Fig. 2 is disposed on the +X side with respect to the light-transmitting element 30. However, the position of the light-emitting element 20 is not limited thereto. For example, the light-emitting element 20 may be disposed on the -X side with respect to the light-transmitting element 30. Moreover, the light-emitting element 20 may be disposed on the +Y side or the -Y side with respect to the light-transmitting element 30. Moreover, the light-emitting element 20 may be disposed in other directions with respect to the light-transmitting element 30.

[0024] The light emitting element 20 includes a semiconductor laminate 21, an electrode 22, and an element substrate 23. Here, the light emitting element 20 includes the electrode 22, the semiconductor laminate 21, and the element substrate 23, which are arranged in the Z direction from the bottom side. The first surface 23a of the element substrate 23 corresponds to the top surface 20a of the light emitting element 20. The bottom surface of the electrode 22 corresponds to the bottom surface 20b of the light emitting element 20. The side surface of the semiconductor laminate 21 facing the light-transmitting element 30 constitutes the side surface 20c of the light emitting element 20. The side surface of the electrode 22 facing the light-transmitting element 30 constitutes the side surface 20c of the light emitting element 20. The side surface of the element substrate 23 facing the light-transmitting element 30 constitutes the side surface 20c of the light emitting element 20.

[0025] The semiconductor stack 21 includes a first semiconductor layer 211, a light emitting layer 212, and a second semiconductor layer 213, which are stacked in this order in the Z direction. The first semiconductor layer 211 and the second semiconductor layer have different conductivity types. The light emitting layer 212 may have a single quantum well (SQW) structure, or a multiple quantum well (MQW) structure including multiple well layers. The semiconductor stack 21 includes multiple semiconductor layers (the first semiconductor layer 211, the light emitting layer 212, and the second semiconductor layer 213) made of nitride semiconductors. The nitride semiconductors include In x Al y Ga 1-x-y The term "luminescence layer 212" includes semiconductors of all compositions in which the composition ratios x and y are changed within the respective ranges in the chemical formula N (0≦x, 0≦y, x+y≦1). The emission peak wavelength of the light-emitting layer 212 can be appropriately selected depending on the purpose. The light-emitting layer 212 is configured to be capable of emitting, for example, visible light or ultraviolet light.

[0026] The semiconductor laminate 21 may include a plurality of light-emitting portions each including a first semiconductor layer 211, a light-emitting layer 212, and a second semiconductor layer 213. When the semiconductor laminate 21 includes a plurality of light-emitting portions, each light-emitting portion may include well layers having different emission peak wavelengths, or may include well layers having the same emission peak wavelength. Note that the case where the emission peak wavelengths are the same includes the case where there is a variation of about several nm. The combination of the emission peak wavelengths of the plurality of light-emitting portions can be appropriately selected. For example, when the semiconductor laminate 21 includes two light-emitting portions, examples of the combination of the light emitted from each light-emitting portion include combinations such as 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 the semiconductor laminate 21 includes three light-emitting portions, an example of the combination of the light emitted from each light-emitting portion is a combination of blue light, green light, and red light. Each light-emitting portion may include one or more well layers having an emission peak wavelength different from that of other well layers.

[0027] The semiconductor laminate 21 emits, for example, blue light. The emission peak wavelength of the semiconductor laminate 21 is preferably 400 nm or more and 530 nm or less, more preferably 420 nm or more and 490 nm or less, and even more preferably 440 nm or more and 460 nm or less, from the viewpoint of the excitation efficiency of the phosphor contained in the light-transmitting member 40. However, the emission peak wavelength of the semiconductor laminate 21 is not limited to these.

[0028] The electrode 22 is disposed on the lower surface of the semiconductor laminate 21. The electrode 22 is connected to the wiring 12. That is, the semiconductor laminate 21 is connected to the wiring 12 via the electrode 22. As shown in FIG. 2, the electrode 22 may be connected to the wiring 12 via the conductive member 75. Note that the electrode 22 may be directly bonded to the wiring 12 without using the conductive member 75. As the conductive member 75, known bonding members such as eutectic solder, conductive paste, and bumps can be used.

[0029] The electrode 22 can be made of a metal material. For example, a single metal such as gold, silver, aluminum, nickel, rhodium, copper, titanium, platinum, palladium, molybdenum, chromium, tungsten, etc., or an alloy containing these metals can be preferably used. Also, the electrode 22 may have a single-layer structure composed of a single metal material, or may have a laminated structure in which a plurality of metal materials are laminated in the Z direction. However, the substance constituting the electrode 22 is not limited to these.

[0030] As shown in FIG. 3, the electrode 22 may include, for example, three electrodes: an n-side electrode 221, a p-side electrode 222, and an n-side electrode 223. Each of the n-side electrodes 221 and 223 is connected to a semiconductor layer corresponding to the n-type semiconductor layer among the first semiconductor layer 211 and the second semiconductor layer 213 provided in the semiconductor laminate 21. The p-side electrode 222 is connected to a semiconductor layer corresponding to the p-type semiconductor layer among the first semiconductor layer 211 and the second semiconductor layer 213 provided in the semiconductor laminate 21.

[0031] The element substrate 23 is a plate-like member having a substantially rectangular shape in a top view. However, the element substrate 23 may have other shapes such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape in a top view. The element substrate 23 has a first surface 23a, a second surface 23b, and one or more side surfaces connecting the first surface 23a and the second surface 23b.

[0032] The first surface 23a is the end face of the element substrate 23 on the +Z side. The first surface 23a faces the light-transmitting member 40. The second surface 23b is the end face of the element substrate 23 on the -Z side. That is, the second surface 23b is the end face on the opposite side of the first surface 23a. The second surface 23b faces the second semiconductor layer 213 of the semiconductor laminate 21.

[0033] The element substrate 23 is disposed between the semiconductor laminate 21 and the light-transmissive member 40. Therefore, the element substrate 23 preferably has light-transmittance. Here, "light-transmittance" means that the transmittance with respect to the light emitted from the semiconductor laminate is 80% or more. As an example of the material constituting the element substrate 23, insulating materials such as sapphire, spinel, and glass, and semiconductor materials such as aluminum nitride and silicon carbide can be mentioned. However, the material constituting the element substrate 23 is not limited to these.

[0034] The element substrate 23 transmits the light emitted from the semiconductor laminate 21. Specifically, the light emitted from the semiconductor laminate 21 enters from the second surface 23b of the element substrate 23, travels inside the element substrate 23, and then exits from the first surface 23a and / or the side surface of the element substrate 23.

[0035] For example, as shown in FIG. 2, the light emitted from the semiconductor laminate 21 includes the light L1 that enters from the second surface 23b of the element substrate 23 and travels toward the first surface 23a of the element substrate 23. After the light L1 exits from the first surface 23a of the element substrate 23, it enters, in a top view, the region of the lower surface 40b of the light-transmissive member 40 that overlaps with the light-emitting element 20. Then, the light L1 passes through the light-transmissive member 40 and exits from the region of the upper surface of the light-transmissive member 40 that overlaps with the light-emitting element 20.

[0036] In addition, the light emitted from the semiconductor laminate 21 includes light L2 that enters from the second surface 23b of the element substrate 23 and travels toward the side surface of the element substrate 23 facing the light-transmissive element 30. That is, the light L2 travels toward the side surface 20c of the light-emitting element 20. Further, after the light L2 exits from the side surface 20c of the light-emitting element 20, it enters the side surface 30c of the light-transmissive element 30. Further, after the light L2 travels inside the light-transmissive element 30, it exits from the upper surface 30a of the light-transmissive element 30. Furthermore, after the light L2 exits from the upper surface 30a of the light-transmissive element 30, in a top view, it enters a region of the lower surface 40b of the light-transmissive member 40 that overlaps with the light-transmissive element 30. Then, the light L2 passes through the light-transmissive member 40 and exits from a region of the upper surface of the light-transmissive member 40 that overlaps with the light-transmissive element 30. Note that the light emitted from the semiconductor laminate 21 may include light traveling in a direction different from the light L1 and the light L2. The light L1 and L2 in FIG. 2 are illustrated with the change in the traveling direction due to the difference in refractive index between members and the like omitted for simplicity of explanation.

[0037] <light-transmissive element 30> Next, the configuration of the light-transmissive element 30 will be described. The light-transmissive element 30 is a plate-like member having a substantially rectangular shape in a top view. The light-transmissive element 30 shown in FIGS. 1 and 2 has a substantially rectangular shape in a top view. However, the light-transmissive element 30 may have other shapes such as a substantially square shape, a substantially circular shape, an elliptical shape, or a substantially polygonal shape in a top view. The light-transmissive element 30 has an upper surface 30a, a lower surface 30b, and one or more side surfaces connecting the upper surface 30a and the lower surface 30b.

[0038] In the light-emitting device 1, it is preferable that the upper surface 30a of the light-transmissive element 30 is positioned at the same height as the upper surface 20a of the light-emitting element 20 with respect to the upper surface 10a of the substrate 10. Thereby, for example, it is possible to easily adjust the light distribution between the light L1 emitted from the upper surface 20a of the light-emitting element 20 and the light L2 emitted from the upper surface 30a of the light-transmissive element 30. In addition, the inclination of the light-transmissive member 40 when the light-transmissive member 40 is arranged can be reduced.

[0039] The light-transmissive element 30 is disposed beside the light-emitting element 20 on the upper surface 10a of the substrate 10. Among one or more side surfaces of the light-transmissive element 30, the side surface facing the light-emitting element 20 is hereinafter referred to as "side surface 30c". In the examples shown in FIGS. 1 and 2, the light-transmissive element 30 is disposed on the -X side with respect to the light-emitting element 20. However, the position of the light-transmissive element 30 is not limited thereto. The light-transmissive element 30 may be disposed, for example, on the +X side with respect to the light-emitting element 20. Further, the light-transmissive element 30 may be disposed on the +Y side or the -Y side with respect to the light-emitting element 20. Further, the light-transmissive element 30 may be disposed in other directions with respect to the light-emitting element 20.

[0040] The light-transmissive element 30 is adjacent to the light-emitting element 20 with a gap therebetween. That is, the side surface 30c of the light-transmissive element 30 is separated from the side surface 20c of the light-emitting element 20. However, the light-transmissive element 30 may be adjacent to the light-emitting element 20 without a gap therebetween. That is, the side surface 30c of the light-transmissive element 30 may be in contact with the side surface 20c of the light-emitting element 20.

[0041] The light-transmissive element 30 and the substrate 10 may be joined via an insulating joining member such as a light-transmissive resin, or may be joined via a conductive joining member such as a eutectic solder, a conductive paste, or a bump. Among these, it is preferable that the light-transmissive element 30 is joined via a conductive joining member in the same manner as the light-emitting element 20. Thereby, the heat dissipation property of the light-emitting device can be improved.

[0042] The light-transmissive element 30 does not have a light-emitting layer. Examples of the material constituting the light-transmissive element 30 include insulating materials such as sapphire, spinel, and glass, and semiconductor materials such as aluminum nitride and silicon carbide. Examples of the glass include borosilicate glass and fused silica. As the material constituting the light-transmissive element 30, glass having a high light transmittance and capable of reducing costs is preferable. Further, by using glass as the material constituting the light-transmissive element 30, light deterioration can be suppressed and mechanical strength can be improved. However, the material constituting the light-transmissive element 30 is not limited to these.

[0043] As shown in FIG. 1, in a top view, the contour C1 surrounding the light-emitting element 20 and the translucent element 30 preferably has a rectangular shape. For example, when viewing the light-emitting device 1 from the +X side or the -X side, it is preferable that the light-emitting element 20 and the translucent element 30 are arranged so as to overlap each other. In a top view, by adjusting the shapes and positional relationships of the light-emitting element 20 and the translucent element 30 so that the contour C1 has a rectangular shape, the light L2 emitted from the side surface 20c of the light-emitting element 20 can reach the translucent element 30 without loss. In the example of FIG. 1, the contour C1 surrounding the light-emitting element 20 and the translucent element 30 is substantially rectangular in a top view, but may be, for example, substantially square.

[0044] <translucent member 40> Next, the configuration of the translucent member 40 will be described. As shown in FIG. 2, the translucent member 40 covers the upper surface 20a of the light-emitting element 20 and the upper surface 30a of the translucent element 30. The translucent member 40 is a plate-like member having a substantially rectangular shape in a top view. However, the translucent member 40 may have other shapes such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape in a top view. The translucent member 40 has an upper surface 40a, a lower surface 40b, and one or more side surfaces 40c connecting the upper surface 40a and the lower surface 40b. The upper surface 40a and the lower surface 40b of the translucent member 40 may have the same area or different areas. When the areas of the upper surface 40a and the lower surface 40b are different, a structure having a step between the upper surface 40a and the lower surface 40b or an inclined surface where the side surface 40c is inclined may be included.

[0045] The light emitted by the light-emitting element 20 is emitted from the upper surface 40a of the translucent member 40. The upper surface 40a of the translucent member 40 corresponds to the light-emitting surface of the light-emitting device 1. The upper surface 40a of the translucent member 40 includes a first light-emitting region 40H that overlaps the light-emitting element 20 and a second light-emitting region 40L that overlaps the translucent element 30 in a top view. From the first light-emitting region 40H, the light L1 that has passed through the upper surface 20a of the light-emitting element 20 is emitted. From the second light-emitting region 40L, the light L2 that has passed through the upper surface 30a of the translucent element 30 is emitted.

[0046] Here, the light L2 emitted from the second light-emitting region 40L is mainly composed of light emitted from the side surface 20c of the light-emitting element 20 and incident on the side surface 30c of the translucent element 30. Further, the translucent element 30 does not include a component corresponding to a light-emitting portion such as a light-emitting layer. Therefore, in a top view, the amount of light of the light L2 emitted from the second light-emitting region 40L is relatively smaller than the amount of light of the light L1 emitted from the first light-emitting region 40H. In other words, the average luminance in the entire first light-emitting region 40H is relatively high, and the average luminance in the entire second light-emitting region 40L is relatively low. Thereby, the light-emitting device 1 including the first light-emitting region 40H and the second light-emitting region 40L having a luminance difference on the light-emitting surface can be provided. For example, in the light-emitting device 1, the average luminance of the second light-emitting region 40L is 20% or more and 80% or less of the average luminance of the first light-emitting region 40H. Hereinafter, the fact that the light-emitting surface of the light-emitting device 1 has a plurality of regions with different average luminances is simply referred to as "having a luminance distribution".

[0047] For example, when the light-emitting device 1 is used as a light source for an automotive headlamp, based on the configuration of the light-emitting device 1, a light distribution pattern having a luminance distribution can be formed on the road surface. Thereby, it becomes possible to simplify a complicated optical system such as a reflector or a lens for distributing the light emitted from the light source, and the headlamp can be downsized. Accordingly, the degree of freedom in design related to the outer shape, internal structure, etc. of the headlamp can be increased.

[0048] Further, on the upper surface 10a of the substrate 10, a luminance distribution can be formed on the upper surface 40a of the translucent member 40 by a simple structure in which the light-emitting element 20 and the translucent element 30 are arranged in a predetermined direction such as the X direction. Therefore, the structure of the light-emitting device 1 can be simplified. Furthermore, the translucent element 30 does not have a light-emitting portion such as a light-emitting layer. Therefore, the power consumption in the light-emitting operation of the light-emitting device 1 can be reduced.

[0049] The light-transmitting member 40 is a member that is disposed on the light-emitting element 20 and transmits the light emitted from the light-emitting element 20 to the outside. The light-transmitting member 40 includes those that transmit 60% or more of the light from the light-emitting element 20 and / or the light whose wavelength has been converted from the light from the light-emitting element 20 (for example, light having an emission peak wavelength in the wavelength range of 320 nm to 850 nm), and those that transmit 80% or more of the light are preferred. The light-transmitting member 40 may be formed of, for example, ceramics such as aluminum nitride, aluminum oxide, yttrium oxide, YAP (yttrium aluminum perovskite), inorganic materials such as glass and sapphire, and organic materials such as resins including one or more of silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, phenolic resin, fluororesin, or hybrid resin.

[0050] The light-transmitting member 40 may contain a phosphor capable of converting at least a part of the light L1 emitted from the light-emitting element 20 and at least a part of the light L2 into light of different wavelengths. Examples of the light-transmitting member 40 containing a phosphor include a sintered body of a phosphor and a light-transmitting base material such as resin, glass, or ceramic containing phosphor powder. The sintered body of the phosphor may be formed by sintering only the phosphor, or may be formed by sintering a mixture of the phosphor and a substance other than the phosphor (for example, a light diffusing substance or a sintering aid). Further, the light-transmitting member 40 may be a member in which a phosphor layer is disposed on the surface of a light-transmitting substrate such as resin, glass, or ceramic. Examples of the phosphor include yttrium aluminum garnet-based phosphors (for example, (Y,Gd)3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet-based phosphors (for example, Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet-based phosphors (for example, Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphors (for example, Ca 10 (PO4)6Cl2:Eu), SAE-based phosphors (for example, Sr4Al 14 O 25 :Eu), chlorosilicate-based phosphors (for example, Ca8MgSi4O 16(Cl2:Eu), silicate phosphors (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu) or α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu), etc., oxynitride phosphors, LSN phosphors (e.g., (La,Y)3Si6N 11 :Ce), BSESN phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA phosphors (e.g., SrLiAl3N4:Eu), CASN phosphors (e.g., CaAlSiN3:Eu) or SCASN phosphors (e.g., (Sr,Ca)AlSiN3:Eu), etc., nitride phosphors, KSF phosphors (e.g., K2SiF6:Mn), KSAF phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1), or fluoride phosphors such as MGF phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2), etc. can be used.

[0051] For example, when the light emitted by the light-emitting element 20 is blue light, the phosphor can preferably use a yttrium aluminum garnet phosphor that converts blue light into yellow light. By mixing the blue light emitted by the light-emitting element 20 and the yellow light wavelength-converted by the phosphor, the light-emitting device 1 can emit white light. However, the phosphor is not limited to a phosphor that converts blue light into yellow light. Also, the light taken out from the light-emitting device 1 is not limited to white light.

[0052] The light-transmitting member 40 may contain fillers such as a light-diffusing substance. Examples of the light-diffusing substance include titanium oxide, barium titanate, aluminum oxide, YAP (yttrium aluminum perovskite), and silicon oxide. However, the light-diffusing substance is not limited to these. Further, the light-transmitting member 40 may have an optical film such as an antireflection film on the upper surface.

[0053] As shown in FIG. 2, the thickness of the light-transmitting member 40 is preferably smaller than the thicknesses of the light-emitting element 20 and the light-transmitting element 30. By the thickness of the light-transmitting member 40 being smaller than the thicknesses of the light-emitting element 20 and the light-transmitting element 30, miniaturization of the light-emitting device 1 can be achieved. Also, the optical path length difference between the light L1 and the light L2 traveling inside the light-transmitting member 40 becomes shorter. Thereby, when the light-transmitting member 40 contains a phosphor, before the chromaticity difference between the light L1 and the light L2 traveling inside the light-transmitting member 40 becomes large, each of the light L1 and the light L2 can be emitted from the upper surface 40a of the light-transmitting member 40. As a result, the chromaticity difference between the light L1 and the light L2 emitted from the upper surface 40a of the light-transmitting member 40 can be reduced.

[0054] In FIG. 2, an example in which the light-transmitting member 40 is composed of one layer containing a phosphor is shown. However, the configuration of the light-transmitting member 40 is not limited to this. For example, the light-transmitting member 40M shown in FIG. 4 has a laminated structure including a light-transmitting substrate 41 and a phosphor layer 42 disposed on the lower surface of the light-transmitting substrate 41.

[0055] Examples of the light-transmitting substrate 41 include molded bodies of light-transmitting materials such as resin, ceramic, and glass, which are described above as the materials of the light-transmitting member 40 described above. Examples of the phosphor layer 42 include those in which phosphor powder is contained in a light-transmitting base material such as resin, glass, and ceramic, and sintered bodies of phosphors.

[0056] The translucent members 40 and 40M shown in FIGS. 2 and 4 are plate-like members that collectively cover the upper surface 20a of the light-emitting element 20 and the upper surface 30a of the translucent element 30. However, the translucent member 40 may include a first translucent member that mainly covers the upper surface 20a of the light-emitting element 20 and a second translucent member that mainly covers the upper surface 30a of the translucent element 30.

[0057] Of the light emitted from the light-emitting element 20, more light enters the first translucent member than the second translucent member. Therefore, it is preferable to make the concentration of the phosphor contained in the first translucent member higher than the concentration of the phosphor contained in the second translucent member. Thereby, the chromaticity difference between the light L1 passing through the first translucent member and the light L2 passing through the second translucent member can be adjusted.

[0058] <Light guide member 50> Next, the configuration of the light guide member 50 will be described. The light guide member 50 is disposed between the light-emitting element 20 and the translucent element 30. The light guide member 50 is translucent to the light emitted from the light-emitting element 20. The light guide member 50 guides the light emitted from the side surface 20c of the light-emitting element 20 to the translucent element 30.

[0059] As shown in FIG. 2, the light guide member 50 covers the side surface 20c of the light-emitting element 20 and the side surface 30c of the translucent element 30 that face each other. The light guide member 50 may cover other regions of the light-emitting element 20, such as the upper surface 20a of the light-emitting element 20. Further, the light guide member 50 may cover other regions of the translucent element 30, such as the upper surface 30a of the translucent element 30.

[0060] The light guide member 50 may be a translucent adhesive member that adheres the light-emitting element 20, the translucent element 30, and the translucent member 40. Examples of the material constituting the light guide member 50 include resins such as epoxy resin, silicone resin, phenol resin, and polyimide resin. However, the material constituting the light guide member 50 is not limited to these.

[0061] <Covering member 60> Next, the configuration of the covering member 60 will be described. As shown in FIG. 2, the covering member 60 exposes the upper surface 40a of the light-transmissive member 40 and covers the side surface 40c of the light-transmissive member 40, the side surface of the light-emitting element 20, and the side surface of the light-transmissive element 30. The covering member 60 is preferably made of an insulating material. Further, the covering member 60 preferably has light-shielding properties. Here, "light-shielding properties" refers to the property of not transmitting light. Examples of the property of not transmitting light include the property of blocking light, the property of absorbing light, and the property of reflecting light. In particular, the covering member 60 preferably has the property of reflecting light. Specifically, it preferably has a reflectance of 60% or more with respect to the light emitted from the light-emitting element 20, and more preferably has a reflectance of 70% or more, 80% or more, or 90% or more.

[0062] The covering member 60 having light-reflecting properties is composed of, for example, light-reflecting particles and a base material. The light-reflecting particles are particles having light-reflecting properties with respect to the light emitted by the light-emitting element 20. The material of the light-reflecting particles is, for example, titanium oxide, zirconium oxide, boron nitride, or aluminum oxide. The light-reflecting particles can contain at least one or more of these. The base material may be composed of an organic material, an inorganic material, or both an organic material and an inorganic material. As the organic material, a resin such as a silicone resin can be used. As the inorganic material, an alkali metal silicate can be used.

[0063] The covering member 60 is composed of, for example, a mixture containing boron nitride and an alkali metal silicate. This mixture can be produced by mixing a mixed powder of boron nitride powder and silicon oxide powder with an alkali solution (for example, potassium hydroxide) and then heat-curing. When the alkali solution is potassium hydroxide, upon heat-curing, silicon oxide reacts with potassium hydroxide to produce potassium silicate, which is an alkali metal silicate. Boron nitride is a member capable of reducing the shrinkage of the mixture during heat-curing. Note that aluminum oxide can be used instead of boron nitride.

[0064] By covering the side surface 40c of the translucent member 40 with the covering member 60, among the light emitted by the light-emitting element 20, the light that reaches the side surface 40c of the translucent member 40 can be reflected toward the upper surface 40a. Further, by covering the side surface of the light-emitting element 20 with the covering member 60, for example, the light that reaches a side surface different from the side surface 20c of the light-emitting element 20 can be reflected toward the translucent member 40. Furthermore, by covering the side surface of the translucent element 30 with the covering member 60, the light that reaches a side surface different from the side surface 30c of the translucent element 30 can be reflected toward the translucent member 40. From these, the light extraction efficiency of the light emitted by the light-emitting element 20 can be improved.

[0065] <Light reflection film 70> The light-emitting device 1 can include a light reflection film 70 that covers the lower surface 30b of the translucent element 30. Examples of the light reflection film 70 include metal films such as silver and aluminum, and dielectric multilayer films such as DBR (Distributed Bragg Reflector). However, the configuration of the light reflection film 70 is not limited to these. The light reflection film 70 may be another optical film having a light reflection function.

[0066] By providing the light-emitting device 1 with the light reflection film 70 disposed on the lower surface 30b of the translucent element 30, among the light incident from the light-emitting element 20 on the translucent element 30, the light that reaches the lower surface 30b of the translucent element 30 can be reflected toward the translucent member 40 side. As a result, more of the light incident on the translucent element 30 can be emitted from the upper surface 30a of the translucent element 30. Consequently, the light extraction efficiency of the light extracted from the upper surface 40a of the translucent member 40 can be improved.

[0067] <Others> Instead of the light-transmissive element 30, another light-emitting element that does not emit light may be disposed adjacent to the light-emitting element 20. The other light-emitting element may include, for example, a semiconductor laminate and a light-transmissive element substrate disposed on the semiconductor laminate, similar to the light-emitting element 20. The semiconductor laminate includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer having a conductivity type opposite to that of the first semiconductor layer. The light L2 emitted by the light-emitting element 20 enters, for example, from the side surface of the element substrate of the other light-emitting element and exits from the upper surface of this element substrate. Further, the light L2 exiting from the upper surface of the element substrate passes through the light-transmissive member 40 and exits from a region overlapping with the other light-emitting element on the upper surface of the light-transmissive member 40. Thereby, similar to the case where the light-emitting device 1 includes the light-transmissive element 30, the luminance of the first light-emitting region 40H and the second light-emitting region 40L can be made different. As a result, the light-emitting device 1 can have a luminance distribution on the light-emitting surface.

[0068] The configuration for preventing the other light-emitting element from emitting light is not limited. As an example, by disposing each of the n-side electrode and the p-side electrode of the other light-emitting element on the second wiring 122 and the third wiring 123 so as to straddle the gap between the second wiring 122 and the third wiring 123, current does not flow through the light-emitting layer, and the other light-emitting element can be prevented from emitting light.

[0069] [Modification Example] Next, a modification example of the light-emitting device according to the first embodiment will be described. Examples of the modification example of the light-emitting device according to the first embodiment include the light-emitting devices 1A to 1D shown in FIG. 5. FIG. 5 is a schematic top view showing an example of the light-emitting devices 1A to 1D according to the modification example of the first embodiment. In FIG. 5, illustration of components other than the light-emitting element 20 and the light-transmissive element 30 among the components included in each of the light-emitting devices 1A to 1D is omitted. However, each of the light-emitting devices 1A to 1D further includes a substrate 10 and a light-transmissive member 40, similar to the light-emitting device 1. Further, each of the light-emitting devices 1A to 1D may include a light guide member 50, a covering member 60, a light reflection film 70, and a conductive member 75, similar to the light-emitting device 1.

[0070] The light-emitting device 1 described with reference to FIGS. 1 to 4 includes one light-emitting element 20 and one translucent element 30. Further, each of the light-emitting element 20 and the translucent element 30 has a substantially rectangular shape in a top view. Furthermore, in the light-emitting device 1, the light-emitting element 20 is disposed on the +X side, and the translucent element 30 is disposed on the -X side.

[0071] On the other hand, the light-emitting device 1A according to the modified example includes a light-emitting element 20 having a substantially square shape in a top view and a translucent element 30 having a substantially rectangular shape in a top view. That is, the light-emitting device 1A includes the light-emitting element 20 and the translucent element 30 having different shapes in a top view. Thereby, the area of the first light-emitting region 40H and the area of the second light-emitting region 40L on the upper surface 40a of the translucent member 40 can be appropriately adjusted. As a result, the luminance distribution on the light-emitting surface can be appropriately adjusted.

[0072] In the light-emitting device 1B, the positional relationship between the light-emitting element 20 and the translucent element 30 is different from that of the light-emitting device 1. Specifically, the light-emitting element 20 is disposed on the -X side, and the translucent element 30 is disposed on the +X side. Further, in a top view, the contour D2 surrounding the light-emitting element 20 and the translucent element 30 is substantially square. In the light-emitting device 1B, the light-emitting element 20 and the translucent element 30 may be arranged along the Y-axis direction. In this case, the light-emitting element 20 may be disposed on the +Y side or the -Y side with respect to the translucent element 30. Thus, by appropriately adjusting the positional relationship between the light-emitting element 20 and the translucent element 30, the position of the first light-emitting region 40H and the position of the second light-emitting region 40L on the upper surface 40a of the translucent member 40 can be appropriately adjusted. When the light-emitting device 1B is used as a light source for a headlight of an automobile, for example, the degree of freedom of the pattern of the light irradiated on the road surface can be improved.

[0073] Next, the light-emitting device 1C includes a light-emitting element 20 and a light-transmissive element 30 that have different numbers from each other. In the example shown in FIG. 5, the light-emitting device 1C includes one light-emitting element 20 and two light-transmissive elements 30. However, the number of the light-emitting elements 20 may be two or more, and the number of the light-transmissive elements 30 may be three or more. By appropriately adjusting the number of the light-emitting elements 20 and the number of the light-transmissive elements 30, the area of the first light-emitting region 40H and the area of the second light-emitting region 40L can be appropriately adjusted. Thereby, the luminance distribution on the light-emitting surface can be adjusted. In the example shown in FIG. 5, the shapes of the light-emitting element 20 and each light-transmissive element 30 in a top view are each substantially square. However, for example, it may include one or more substantially rectangular light-emitting elements 20 and light-transmissive elements 30. Further, in the example shown in FIG. 5, the contour D3 surrounding the light-emitting element 20 and the light-transmissive elements 30 in a top view is substantially rectangular, but it may be substantially square. Further, in the example shown in FIG. 5, one light-emitting element 20 and two light-transmissive elements 30 are arranged along the X-axis direction. However, for example, they may be arranged along the Y-axis direction.

[0074] The light-emitting device 1D includes a light-emitting element 20 and a plurality of translucent elements 30 having different shapes in a top view. In the example shown in FIG. 5, the light-emitting device 1D includes a light-emitting element 20 having a substantially square shape in a top view, a translucent element 30D1 having a substantially rectangular shape in a top view, and a translucent element 30D2 having a substantially square shape in a top view. The translucent element 30D1 is disposed on the -X side with respect to the light-emitting element 20, while the translucent element 30D2 is disposed on the +Y side with respect to the light-emitting element 20. In this way, by arranging a plurality of translucent elements 30 having different shapes in a top view adjacent to the light-emitting element 20 in different directions, the area and shape of the first light-emitting region 40H and the area and shape of the second light-emitting region 40L on the upper surface 40a of the translucent member 40 can be appropriately adjusted. Thereby, when the light-emitting device 1D is used as a light source for a headlight of an automobile, for example, the degree of freedom of the pattern of the light irradiated on the road surface can be improved. In the example shown in FIG. 5, the contour D4 surrounding the light-emitting element 20 and the translucent element 30 is substantially square in a top view, but it may be substantially rectangular.

[0075] The number and the shape in a top view of the light-emitting element 20 and the number and the shape on the upper surface of the translucent element 30 are not limited to those shown in FIG. 5. For example, a light-emitting device including one light-emitting element 20 having a substantially square shape in a top view and one translucent element 30 having a substantially square shape in a top view may be used. In this case, the direction in which the light-emitting element 20 and the translucent element 30 are arranged may be the X-axis direction or the Y-axis direction.

[0076] Further, for example, a light-emitting device including one light-emitting element 20 having a substantially square shape in a top view and one translucent element 30 having a substantially rectangular shape in a top view may be used. In this case, the direction in which the light-emitting element 20 and the translucent element 30 are arranged may be the X-axis direction or the Y-axis direction.

[0077] Furthermore, for example, a light-emitting device may include two light-emitting elements 20 having a substantially square shape in a top view and two light-transmissive elements 30 having a substantially square shape in a top view. In this case, in the top view, the contour surrounding the light-emitting elements 20 and the light-transmissive elements 30 may be substantially square or substantially rectangular. Also, for example, the two light-emitting elements 20 may be arranged with their side surfaces facing each other. The two light-transmissive elements 30 may be arranged with their side surfaces facing each other. However, the positional relationship between the light-emitting elements 20 and the light-transmissive elements 30 is not limited to this.

[0078] [Second Embodiment] [Example of the overall configuration of the light-emitting device 6] Next, with reference to FIGS. 6 and 7, a configuration example of the light-emitting device 6 according to the second embodiment will be described. FIG. 6 is a schematic top view showing an example of the overall configuration of the light-emitting device 6 according to the second embodiment. FIG. 7 is a schematic partial cross-sectional view of the light-emitting device 6 according to the second embodiment taken along line VII-VII shown in FIG. 6.

[0079] The light-emitting device 6 according to the second embodiment is different from the first embodiment in that it includes a light-emitting element 6A including, for example, a first light-emitting portion 610 and a second light-emitting portion 650 adjacent to each other in the X-axis direction. Hereinafter, in the second embodiment, the same reference numerals are given to the same constituent members as those in the first embodiment, and the description will be omitted as appropriate.

[0080] The first light-emitting portion 610 includes a semiconductor laminate 620 and an electrode 630 disposed on the lower surface of the semiconductor laminate 620. The semiconductor laminate 620 includes a first semiconductor layer 621, a light-emitting layer 622, and a second semiconductor layer 623. The first semiconductor layer 621 and the second semiconductor layer 623 have different conductivity types. For example, when the conductivity type of the first semiconductor layer 621 is n-type, the conductivity type of the second semiconductor layer 623 is p-type. Also, when the conductivity type of the first semiconductor layer 621 is p-type, the conductivity type of the second semiconductor layer 623 is n-type.

[0081] The second light-emitting part 650 includes a semiconductor laminate 660 and an electrode 670 disposed on the lower surface of the semiconductor laminate 660. The semiconductor laminate 660 includes a first semiconductor layer 661, a light-emitting layer 662, and a second semiconductor layer 663. The first semiconductor layer 661 and the second semiconductor layer 663 have different conductivity types from each other. For example, when the conductivity type of the first semiconductor layer 661 is n-type, the conductivity type of the second semiconductor layer 663 is p-type. Also, when the conductivity type of the first semiconductor layer 661 is p-type, the conductivity type of the second semiconductor layer 663 is n-type.

[0082] The light-emitting element 6A further includes a light-transmissive element substrate 23 that supports the first light-emitting part 610 and the second light-emitting part 650. The first light-emitting part 610 and the second light-emitting part 650 are arranged adjacent to each other with a gap on the second surface 23b of the element substrate 23. Light L3 that travels upward among the light emitted by the first light-emitting part 610 passes through the element substrate 23 and is emitted from the first surface 23a of the element substrate 23. Light L4 that travels upward among the light emitted by the second light-emitting part 650 passes through the element substrate 23 and is emitted from the first surface 23a of the element substrate 23. Also, light L5 that travels in the lateral direction among the light emitted by the second light-emitting part 650 is emitted from the side surface of the element substrate 23 that faces the light-transmissive element 30. Further, the light L5 is incident on the side surface 30c of the light-transmissive element 30, passes through the light-transmissive element 30, and is emitted from the upper surface 30a of the light-transmissive element 30.

[0083] In this way, since the light-emitting element 6A has the first light-emitting part 610 and the second light-emitting part 650 arranged adjacent to each other on the second surface 23b of the element substrate 23, in a region overlapping the light-emitting element 6A of the light-transmissive member 40 in a top view, a plurality of light-emitting regions can be provided. Thereby, the degree of freedom of the light-emitting mode can be increased, such as creating a luminance difference between the light L3 emitted by the first light-emitting part 610 and the light L4 emitted by the second light-emitting part 650, or driving the first light-emitting part 610 and the second light-emitting part 650 individually.

[0084] The first light-emitting part 610 and the second light-emitting part 650 may be connected in series via a wiring 80 disposed on the upper surface of the base material 11. In this case, the area of the first light-emitting part 610 and the area of the second light-emitting part 650 in a top view may be the same or different. For example, by making the area of the upper surface of the first light-emitting part 610 different from the area of the upper surface of the second light-emitting part 650, the current density flowing through the first light-emitting part 610 and the current density flowing through the second light-emitting part 650 can be made different from each other. As a result, the luminance of the light L3 emitted by the first light-emitting part 610 and the luminance of the light L4 emitted by the second light-emitting part 650 can be made different from each other.

[0085] In the examples shown in FIGS. 6 and 7, the area of the upper surface of the first light-emitting part 610 is smaller than the area of the upper surface of the second light-emitting part 650 disposed on the -X side with respect to the first light-emitting part 610. Further, the light-transmissive element 30 is disposed on the opposite side of the first light-emitting part 610 with the second light-emitting part 650 interposed therebetween. In the examples shown in FIGS. 6 and 7, on the upper surface 10a of the substrate 10, the first light-emitting part 610, the second light-emitting part 650, and the light-transmissive element 30 are arranged in this order from the +X side toward the -X side. However, the direction in which the first light-emitting part 610, the second light-emitting part 650, and the light-transmissive element 30 are arranged is not limited to this.

[0086] By arranging the first light-emitting part 610, the second light-emitting part 650, and the light-transmissive element 30 in this order along a predetermined direction, on the upper surface 40a of the light-transmissive member 40, the light L3 having the highest luminance is emitted from the light emission region 40H1 overlapping the first light-emitting part 610, the light L4 having the next highest luminance is emitted from the light emission region 40H2 overlapping the second light-emitting part 650, and the light L5 having the lowest luminance is emitted from the light emission region 40L1 overlapping the light-transmissive element 30. That is, a plurality of light emission regions on the upper surface 40a of the light-transmissive member 40 can be arranged in order in a predetermined direction such as the X-axis direction according to the luminance of the emitted light. As a result, a luminance distribution that continuously changes in a predetermined direction can be formed on the upper surface 40a of the light-transmissive member 40.

[0087] Next, with reference to FIG. 8, an example of wiring 80 for connecting the first light-emitting unit 610 and the second light-emitting unit 650 in series will be described. FIG. 8 is a schematic top view for explaining a substrate 10 of a light-emitting device 6 according to the second embodiment.

[0088] As shown in FIG. 8, the wiring 80 includes a first wiring 81, a second wiring 82, and a third wiring 83. The first wiring 81 is connected to, for example, the n-side electrodes 631 and 633 among the electrodes 630 included in the first light-emitting unit 610, and the p-side electrode 672 among the electrodes 670 included in the second light-emitting unit 650. The second wiring 82 is connected to the n-side electrodes 671 and 673 among the electrodes 670 included in the second light-emitting unit 650. The third wiring 83 is connected to the p-side electrode 632 among the electrodes 630 of the first light-emitting unit 610. One of the first wiring 81 and the third wiring 83 is connected to an external power source. However, the layout of the wiring 80 and the connection relationship with the electrodes 630 and 670 are not limited thereto.

[0089] Unlike the examples shown in FIGS. 6 to 8, the first light-emitting unit 610 and the second light-emitting unit 650 may be electrically independent. In this case, the wiring 80 includes a plurality of wirings that are electrically independent of each other. Specifically, the wiring 80 includes a wiring for supplying power to the first light-emitting unit 610 and a wiring for supplying power to the second light-emitting unit 650.

[0090] Although the preferred embodiments and the like have been described in detail above, the present invention is not limited to the above-described embodiments and the like, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope described in the claims.

[0091] Aspects of the present disclosure are as follows, for example. <Item 1> A substrate, A light-emitting element disposed on the upper surface of the substrate and including a light-emitting layer, A light-transmissive element disposed adjacent to the light-emitting element on the upper surface of the substrate and not including a light-emitting layer, A light-transmissive member covering the upper surfaces of the light-emitting element and the light-transmissive element, And a light-emitting device comprising the same. <Item 2> Further comprising a light guide member disposed between the light-emitting element and the light-transmissive element and covering the side surfaces of the light-emitting element and the light-transmissive element facing each other. The light-emitting device according to <Item 1>. <Item 3> Further comprising a covering member that exposes the upper surface of the light-transmissive member and covers the side surface of the light-transmissive member, the side surface of the light-emitting element, and the side surface of the light-transmissive element. The light-emitting device according to <Item 1> or <Item 2>. <Item 4> The light-emitting element includes an element substrate having a first surface and a second surface opposite to the first surface, and a semiconductor laminate disposed on the second surface of the element substrate and having a first semiconductor layer, a light-emitting layer, and a second semiconductor layer in this order, and includes a first light-emitting portion and a second light-emitting portion disposed adjacent to each other. The light-emitting device according to <Items 1> to <Item 3>. <Item 5> The area of the light-emitting surface of the first light-emitting portion is smaller than the area of the light-emitting surface of the second light-emitting portion. The substrate includes wiring for connecting the first light-emitting portion and the second light-emitting portion in series. The light-emitting device according to <Item 4>. <Item 6> On the upper surface of the substrate, the light-transmissive element is disposed adjacent to the second light-emitting portion. The light-emitting device according to <Item 5>. <Item 7> Further comprising a light reflection film covering the lower surface of the light-transmissive element. The light-emitting device according to any one of <Items 1> to <Item 6>. <Item 8> The light-transmissive member contains a phosphor. The light-emitting device according to any one of <Items 1> to <Item 7>. <Item 9> The light-transmissive member includes a light-transmissive substrate and a phosphor layer disposed on the lower surface of the substrate. The phosphor layer has a first region disposed on the upper surface of the light-emitting element and a second region disposed on the upper surface of the light-transmissive element. The concentration of the phosphor in the first region is higher than the concentration of the phosphor in the second region. The light-emitting device according to <Item 8>. <Item 10> The thickness of the light-transmitting member is smaller than the thicknesses of the light-emitting element and the light-transmitting element. The light-emitting device according to <Item 8> or <Item 9>. <Item 11> The upper surfaces of the light-emitting element and the light-transmitting element are located at the same height with reference to the upper surface of the substrate. The light-emitting device according to any one of <Item 1> to <Item 10>. <Item 12> The light-transmitting element is glass. The light-emitting device according to any one of <Item 1> to <Item 11>. <Item 13> In a top view, the contour surrounding the light-emitting element and the light-transmitting element has a rectangular shape. The light-emitting device according to any one of <Item 1> to <Item 12>.

Description of Reference Numerals

[0092] 1, 1A, 1B, 1C, 1D, 6 Light-emitting device 10 Substrate 11 Base material 12, 80 Wiring 20 Light-emitting element 21 Semiconductor laminate 22 Electrode 23 Element substrate 30 Light-transmitting element 40, 40M Light-transmitting member 50 Light guide member 60 Coating member 70 Light reflection film 75 Conductive member 610 First light-emitting part 650 Second light-emitting part

Claims

1. A substrate, a light-emitting element disposed on the upper surface of the substrate and including a light-emitting layer, a light-transmissive element disposed adjacent to the light-emitting element on the upper surface of the substrate and not including a light-emitting layer, a light-transmissive member covering the upper surfaces of the light-emitting element and the light-transmissive element, A light-emitting device comprising the above.

2. The light-emitting device according to claim 1, further comprising a light guide member disposed between the light-emitting element and the light-transmissive element and covering side surfaces of the light-emitting element and the light-transmissive element facing each other. The light-emitting device according to claim 1.

3. The light-emitting device according to claim 1 or 2, further comprising a covering member exposing the upper surface of the light-transmissive member and covering side surfaces of the light-transmissive member, the light-emitting element, and the light-transmissive element. The light-emitting device according to claim 1 or 2.

4. The light-emitting element includes an element substrate having a first surface and a second surface opposite to the first surface, and a semiconductor laminate disposed on the second surface of the element substrate and having a first semiconductor layer, a light-emitting layer, and a second semiconductor layer in this order, and includes a first light-emitting portion and a second light-emitting portion disposed adjacent to each other. The light-emitting device according to claim 1 or 2.

5. An area of a light-emitting surface of the first light-emitting portion is smaller than an area of a light-emitting surface of the second light-emitting portion, The substrate includes a wiring for connecting the first light-emitting portion and the second light-emitting portion in series. The light-emitting device according to claim 4.

6. On the upper surface of the substrate, the light-transmissive element is disposed adjacent to the second light-emitting portion. The light-emitting device according to claim 5.

7. The light-emitting device according to claim 1 or 2, further comprising a light reflection film covering a lower surface of the light-transmissive element. The light-emitting device according to claim 1 or 2.

8. The light-transmissive member contains a phosphor. The light-emitting device according to claim 1 or 2.

9. The light-transmissive member includes a light-transmissive substrate and a phosphor layer disposed on a lower surface of the substrate. The phosphor layer has a first region disposed on the upper surface of the light-emitting element and a second region disposed on the upper surface of the light-transmissive element. A concentration of the phosphor in the first region is higher than a concentration of the phosphor in the second region. The light-emitting device according to claim 8.

10. A thickness of the light-transmissive member is smaller than thicknesses of the light-emitting element and the light-transmissive element. The light-emitting device according to claim 8.

11. Upper surfaces of the light-emitting element and the light-transmissive element are located at the same height with reference to the upper surface of the substrate. The light-emitting device according to claim 1 or 2.

12. The light-transmissive element is glass. The light-emitting device according to claim 1 or claim 2.

13. In a top view, the contour surrounding the light-emitting element and the light-transmissive element has a rectangular shape. The light-emitting device according to claim 1 or claim 2.

Images