Light-emitting device

Abstract

To provide a light-emitting device with minimal brightness unevenness. [Solution] The light-emitting device comprises a substrate and wiring arranged on the upper surface of the substrate, a light-emitting element 20 flip-chip mounted on the wiring via a plurality of bumps 40, and a light-transmitting member arranged on the light-emitting element. The plurality of bumps include a plurality of first bumps 40a arranged in a first region R1 that includes a virtual line passing through the midpoints of the two long sides of the upper surface of the light-emitting element in a top view, a plurality of second bumps 40b arranged in a second region R2 adjacent to one side of the first region in the direction in which the long sides extend, and a plurality of third bumps 40c arranged in a third region R3 adjacent to the other side of the first region in the direction in which the long sides extend, wherein the number of second bumps and the number of third bumps are greater than the number of first bumps, and the first bumps, second bumps and third bumps are arranged symmetrically with respect to the virtual line in a top view.

Description

[Technical Field]

[0001] This disclosure relates to a light-emitting device. [Background technology]

[0002] A light-emitting device equipped with multiple light-emitting elements is known as a light source for vehicle headlights such as headlamps (Patent Document 1). This light-emitting device is configured to include two light-emitting elements mounted on a mounting substrate, and a light-transmitting member extends across the two light-emitting elements along the direction of arrangement of the two light-emitting elements, forming a rectangular light-emitting surface. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-97139 [Overview of the project] [Problems that the invention aims to solve]

[0004] This disclosure aims to provide a light-emitting device with minimal brightness unevenness. [Means for solving the problem]

[0005] A light-emitting device according to one embodiment of the present disclosure comprises a substrate, a wiring arranged on the upper surface of the substrate, a light-emitting element flip-chip mounted on the wiring via a plurality of bumps, and a translucent member arranged on the light-emitting element, wherein the upper surface of the translucent member is a rectangle with an aspect ratio of 1:3 or more and 1:5 or less (ratio of short side to long side), the upper surface of the light-emitting element is a rectangle with a smaller aspect ratio than the upper surface of the translucent member, and the plurality of bumps are, in a top view, two of the upper surfaces of the light-emitting element The system includes a plurality of first bumps arranged in a first region containing imaginary lines passing through the midpoints of each of the long sides of the system, a plurality of second bumps arranged in a second region adjacent to one side of the first region in the direction in which the long sides extend, and a plurality of third bumps arranged in a third region adjacent to the other side of the first region in the direction in which the long sides extend, wherein the number of second bumps and the number of third bumps are greater than the number of first bumps, and the first bumps, second bumps and third bumps are arranged symmetrically with respect to the imaginary lines in a top view. [Effects of the Invention]

[0006] According to one embodiment of this disclosure, a light-emitting device with less brightness unevenness can be provided. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic perspective view showing the light-emitting device according to this embodiment. [Figure 2] This is a cross-sectional view along line II-II in Figure 1. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] This is a schematic top view showing the substrate constituting the light-emitting device according to this embodiment. [Figure 5] This is a schematic bottom view showing the substrate constituting the light-emitting device according to this embodiment. [Figure 6] This is a schematic top view (1) illustrating the arrangement of bumps constituting the light-emitting device according to this embodiment. [Figure 7]This is a schematic top view (2) illustrating the arrangement of bumps constituting the light-emitting device according to this embodiment. [Figure 8] This is a schematic perspective view showing the translucent members constituting the light-emitting device according to this embodiment. [Figure 9] This is a schematic top view showing the translucent member and light-emitting element that constitute the light-emitting device according to this embodiment. [Figure 10] This is a schematic bottom view showing the light-emitting element that constitutes the light-emitting device according to this embodiment. [Figure 11] Figure 10 is a cross-sectional view along the line XI-XI. [Modes for carrying out the invention]

[0008] Hereinafter, the light-emitting device according to this disclosure (which may be referred to as the "light-emitting device according to the embodiment") will be described with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "up," "down," and other terms including these terms) will be used as needed. However, the use of these terms is for the purpose of facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Furthermore, the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components.

[0009] In addition, the embodiments described below exemplify a light-emitting device or the like for embodying the technical idea of the present invention, and do not limit the present invention thereto. Further, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention only thereto, but are intended to be illustrative unless otherwise specified. Also, the content described in one embodiment is applicable to other embodiments and modifications. Also, the sizes and positional relationships of the members shown in the drawings may be exaggerated for clarity of explanation. Furthermore, in order to avoid making the drawings overly complex, schematic drawings with some elements omitted or end views showing only the cut surface as a cross-sectional view may be used. Also, even when some members change in size or shape due to processing or change in size or shape due to pressing, they may be described using the same name.

[0010] <Light-emitting device 1 according to this embodiment> FIG. 1 is a perspective view schematically showing the light-emitting device according to this embodiment. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1. FIGS. 2 and 3 show a cross-section of the light-emitting device 1 cut by a plane perpendicular to the upper surface 20a of the light-emitting element 20. The same applies to the following cross-sectional views. FIG. 4 is a top view schematically showing the substrate constituting the light-emitting device according to this embodiment. FIG. 5 is a bottom view schematically showing the substrate constituting the light-emitting device according to this embodiment.

[0011] In each of the drawings, for reference purposes, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are shown as needed. The direction parallel to the X-axis is referred to as the first direction X, the direction parallel to the Y-axis is referred to as the second direction Y, and the direction parallel to the Z-axis is referred to as the third direction Z. Also, in the first direction X, the direction in which the arrow points is referred to as the +X direction, and the opposite direction of the +X direction is referred to as the -X direction. In the second direction Y, the direction in which the arrow points is referred to as the +Y direction, and the opposite direction of the +Y direction is referred to as the -Y direction. In the third direction Z, the direction in which the arrow points is referred to as the +Z direction, and the opposite direction of the +Z direction is referred to as 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 during use is arbitrary. Also, viewing the object from the +Z direction to the -Z direction is referred to as a top view.

[0012] As shown in FIGS. 1 to 5, the light-emitting device 1 has at least one substrate 10, one light-emitting element 20, one translucent member 60, and a plurality of bumps 40. Note that the light-emitting device 1 may further have a protective element 30, a bonding member 50, and a covering member 70.

[0013] The substrate 10 has a base material 11 and wirings 12 disposed on the upper surface 11a of the base material 11. The substrate 10 may further have wirings 13 disposed on the lower surface 11b of the base material 11. The wiring 12 may include a first wiring 12a and a second wiring 12b. The wiring 13 may include a third wiring 13a, a fourth wiring 13b, a fifth wiring 13c, and a sixth wiring 13d.

[0014] The light-emitting element 20 has an upper surface 20a, a plurality of side surfaces 20c continuous with the upper surface 20a, and a lower surface 20b opposite to the upper surface 20a. The plurality of side surfaces 20c are continuous with the upper surface 20a and the lower surface 20b. In other words, each of the plurality of side surfaces 20c has an outer edge that is continuous with the outer edge of the upper surface 20a and the outer edge of the lower surface 20b. The light-emitting element 20 can emit light from the upper surface 20a, the lower surface 20b, and the side surfaces 20c.

[0015] The light-emitting element 20 has an external shape that is approximately a rectangular parallelepiped. That is, the top surface 20a and the bottom surface 20b of the light-emitting element 20 are rectangular, and the four sides 20c of the light-emitting element 20 are rectangular or square. For example, the two long sides of the top surface 20a of the light-emitting element 20 are parallel to the first direction X, and the two short sides are parallel to the second direction Y. Also, the normal to the top surface 20a is parallel to the third direction Z.

[0016] The light-emitting element 20 includes a first region R1 containing a virtual line V passing through the midpoints of the two long sides on the upper surface 20a of the rectangle, a second region R2 adjacent to one side of the first region R1 in the direction in which the long sides extend, and a third region R3 adjacent to the other side of the first region R1 in the direction in which the long sides extend.

[0017] The light-emitting element 20 is positioned on the substrate 10. The light-emitting element 20 is flip-chip mounted on the wiring 12 of the substrate 10 via a plurality of bumps 40, with its lower surface 20b facing the substrate 10. Specifically, in the light-emitting device 1, the light-emitting element 20 is flip-chip mounted on the substrate 10 via a plurality of bumps 40 such that the first region R1 faces the first wiring 12a, and the second region R2 and third region R3 face the second wiring 12b.

[0018] The upper surface 20a of the light-emitting element 20 is a rectangle with a smaller aspect ratio than the upper surface 61 of the light-transmitting member 60. The upper surface 20a of the light-emitting element 20 may be a rectangle with an aspect ratio of 1:2 or more and 1:4 or less, which is the ratio of the short side to the long side. The length of the long side of the upper surface 20a of the light-emitting element 20 may be, for example, 1000 μm or more and 3000 μm or less.

[0019] The joining member 50 is positioned between the lower surface 62 of the light-transmitting member 60 and the upper surface 20a of the light-emitting element 20, and joins the light-transmitting member 60 and the light-emitting element 20. The joining member 50 covers at least a portion of the side surface 20c and the upper surface 20a of the light-emitting element 20. Specifically, the joining member 50 covers the entire upper surface 20a of the light-emitting element 20 and at least a portion of the upper end side (i.e., the outer edge side connected to the upper surface 20a) of each side surface 20c. The joining member 50 has a side surface 50c that connects the side surface 20c of the light-emitting element 20 and the lower surface 62 of the light-transmitting member 60.

[0020] The joining member 50 preferably covers a larger area of ​​each side surface 20c of the light-emitting element 20, and more preferably covers the entire surface 20c of each side surface 20c. That is, the side surface 50c of the joining member 50 preferably contacts the side surface 20c of each side surface 20c of the light-emitting element 20 at a position close to the lower end (i.e., the side connected to the bottom surface 20b), and more preferably contacts the lower end of each side surface 20c. Specifically, on each side surface 20c of the light-emitting element 20, it is preferable that the joining member 50 covers an area of ​​75% to 100% in the height direction from the upper end, and more preferably that the joining member 50 covers an area of ​​90% to 100%.

[0021] The bonding member 50 is transparent to light emitted from the light-emitting element 20. Light emitted from the light-emitting element 20 enters the transparent member 60 via the bonding member 50 and exits to the outside via the transparent member 60. The bonding member 50 may contain light-scattering particles as an additive. By having the bonding member 50 containing light-scattering particles cover a larger area of ​​the side surface 20c of the light-emitting element 20, more of the light emitted from the side surface 20c of the light-emitting element 20 can be guided to the lower surface 62 side of the transparent member 60.

[0022] The translucent member 60 is placed on the light-emitting element 20. Specifically, the translucent member 60 is placed on the upper surface 20a of the light-emitting element 20 via a bonding member 50. The upper surface 61 of the translucent member 60 constitutes a part of the upper surface of the light-emitting device 1 as the main light-emitting surface of the light-emitting device 1. The upper surface 61 of the translucent member 60 is a rectangle with an aspect ratio of 1:3 or more and 1:5 or less, which is the ratio of the short side to the long side. The translucent member 60 is placed on the light-emitting element 20 via a bonding member 50 placed on the upper surface 20a of the light-emitting element 20, such that the lower surface 62 of the translucent member 60 faces the upper surface 20a of the light-emitting element 20. The translucent member 60 is placed so that the lower surface 62 of the translucent member 60 is substantially parallel to the upper surface 20a of the light-emitting element 20. Preferably, the shape of the lower surface 62 of the translucent member is similar to the shape of the upper surface 20a of the light-emitting element. For example, if the upper surface 20a of the light-emitting element is rectangular, it is preferable that the lower surface 62 of the light-transmitting member is also rectangular.

[0023] The covering member 70 exposes the upper surface 61 of the light-transmitting member 60 and covers the side surface 20c of the light-emitting element 20. The covering member 70 may directly cover the side surface 20c of the light-emitting element 20, or it may cover it via the joining member 50. The covering member 70 may also cover the surfaces of the first wiring 12a and the second wiring 12b exposed from the bump 40, and may further cover the upper surface 11a of the base material 11 exposed from the first wiring 12a and the second wiring 12b. The covering member 70 may also cover the lower surface 20b of the light-emitting element 20. If the light-emitting device 1 has a protective element 30, it is preferable that the covering member 70 covers the upper surface and side surface of the protective element 30.

[0024] Figure 6 is a schematic top view (1) illustrating the arrangement of bumps constituting the light-emitting device according to this embodiment, and shows the light-emitting element and the bumps from above. In Figure 6, a dashed line V is shown passing through the midpoints of the two long sides of the top surface 20a of the light-emitting element 20. The dashed line V is parallel to the second direction Y.

[0025] As shown in Figure 6, the multiple bumps 40 include multiple first bumps 40a located in a first region R1 containing a virtual line V in a top view. In the example in Figure 6, the center of each first bump 40a is located on the virtual line V in a top view. The multiple bumps 40 also include multiple second bumps 40b located in a second region R2 adjacent to one side of the first region R1 in a first direction X extending from the long side of the top surface 20a in a top view. The multiple bumps 40 also include multiple third bumps 40c located in a third region R3 adjacent to the other side of the first region R1 in the first direction X in a top view.

[0026] The number of second bumps 40b and third bumps 40c is greater than the number of first bumps 40a. Preferably, the first bumps 40a, second bumps 40b, and third bumps 40c are arranged symmetrically with respect to the imaginary line V when viewed from above. This allows the rectangular light-emitting element 20 to be bonded to the substrate 10 with equivalent bonding strength on one side and the other. In the example in Figure 6, there are 3 first bumps 40a and 16 second bumps 40b and 16 third bumps 40c, but the method is not limited to this.

[0027] The multiple bumps 40 may include multiple bumps arranged in a row parallel to the imaginary line V when viewed from above. In the example in Figure 6, the multiple first bumps 40a are arranged in a row parallel to the imaginary line V. The multiple second bumps 40b and the multiple third bumps 40c are arranged in a 4x4 matrix when the first direction X is the row direction and the second direction Y is the column direction.

[0028] The bump 40 may be circular or non-circular in top view. In the example shown in Figure 6, the bump 40 is elliptical in top view, with its major axis in the first direction X, where the long side of the top surface 20a extends. With this shape, the area in contact with the bump 40 in the longitudinal direction of the substrate 10 and the light-emitting element 20 increases, allowing the rectangular light-emitting element 20 to be bonded more firmly to the substrate 10.

[0029] Figure 7 is a schematic top view (2) illustrating the arrangement of bumps constituting the light-emitting device according to this embodiment, and is a top view of the bumps and substrate. As shown in Figure 7, the first wiring 12a is connected to the first bump 40a, and the second wiring 12b is connected to the second bump 40b and the third bump 40c. The multiple bumps 45 are bumps that connect the protective element 30 and the wiring 12. The multiple bumps 45 include bumps connected to the first wiring 12a and bumps connected to the second wiring 12b.

[0030] Figure 8 is a perspective view showing a translucent member constituting the light-emitting device according to this embodiment. Figure 9 is a top view showing the translucent member and light-emitting element constituting the light-emitting device according to this embodiment. As shown in Figures 8 and 9, the translucent member 60 may have a convex shape that protrudes toward the upper surface 61. The translucent member 60 includes an upper surface 61, a lower surface 62 which is the opposite surface of the upper surface 61, a first side surface 63a connected to the upper surface 61, a second side surface 63b connected to the lower surface 62, and a second upper surface 64 located between the first side surface 63a and the second side surface 63b.

[0031] In the light-transmitting member 60, the upper surface 61 and the lower surface 62 are planes parallel to each other. The area of ​​the upper surface 61 is smaller than the area of ​​the lower surface 62. The first side surface 63a includes an inclined surface toward the second side surface 63b. The inclined surface is, for example, a curved surface. The second side surface 63b is a plane perpendicular to the lower surface 62. The aspect ratio of the upper surface 61 is greater than the aspect ratio of the lower surface 62. The aspect ratio of the lower surface 62 may be the same as the aspect ratio of the upper surface 20a of the light-emitting element 20. The height from the lower surface 62 to the second upper surface 64 is lower than the height from the second upper surface 64 to the upper surface 61.

[0032] The longer side of the upper surface 20a of the light-emitting element 20 is located between the first side surface 63a and the second side surface 63b of the light-transmitting member 60 when viewed from above. In other words, the longer side of the upper surface 20a of the light-emitting element 20 is located in a position that overlaps with the second upper surface 64 of the light-transmitting member 60 when viewed from above.

[0033] By making the translucent member 60 a convex shape as shown in Figures 8 and 9, the light emitted from the upper surface 20a of the light-emitting element 20, which has a smaller aspect ratio than the upper surface 61 of the translucent member 60, can be efficiently incident from the lower surface 62. Then, the light incident from the lower surface 62 can be emitted from the upper surface 61, which has a larger aspect ratio than the lower surface 62.

[0034] In the light-emitting device 1, when current is supplied to the light-emitting element 20 from an external power source, the light-emitting element 20 emits light. Of the light emitted by the light-emitting element 20, the light that travels upward (i.e., towards the lower surface of the translucent member) is taken out of the light-emitting device 1 via the bonding member 50 and the translucent member 60. Also, of the light emitted by the light-emitting element 20, the light that travels downward is reflected by the covering member 70 and the substrate 10 and taken out of the light-emitting device 1 via the light-emitting element 20, the bonding member 50 and the translucent member 60. Furthermore, of the light emitted by the light-emitting element 20, the light that travels laterally is reflected at the interface between the side surface 20c of the bonding member 50 and the covering member 70 and taken out of the light-emitting device 1 via the bonding member 50 and the translucent member 60.

[0035] Thus, the light-emitting device 1 comprises one substrate, one light-emitting element 20, and one translucent member 60 placed on the light-emitting element 20. The upper surface 20a of the light-emitting element 20 and the upper surface 61 of the translucent member 60 are rectangles with a large aspect ratio (specifically, 1:3 or more) between the short side and the long side. This makes it possible to reduce brightness unevenness on the light-emitting surface in a light-emitting device having a horizontally elongated light-emitting surface with a large aspect ratio between the short side and the long side.

[0036] When attempting to obtain a light-emitting device having a horizontally elongated light-emitting surface with a large aspect ratio between the short side and the long side, one possible configuration is to place a single translucent member on top of multiple light-emitting elements, such as a square light-emitting surface. However, in this case, the area directly above the region corresponding to the space between each light-emitting element will have lower brightness compared to the area directly above the light-emitting element, making it easy for brightness unevenness to occur on the light-emitting surface. On the other hand, in a configuration such as the light-emitting device 1 according to this embodiment, in which a single translucent member 60 is placed on top of a single light-emitting element 20, brightness unevenness is less likely to occur. Furthermore, in a light-emitting device having a single light-emitting surface, a configuration in which multiple light-emitting elements are mounted on a single substrate results in a large amount of power being supplied to the multiple light-emitting elements. In contrast, in a configuration such as the light-emitting device 1, in which one light-emitting element 20 is mounted on a single substrate, the power supplied can be reduced compared to the above configuration. A light-emitting device 1 having such a horizontally elongated light-emitting surface can easily form a light distribution pattern suitable for low-beam light distribution patterns and can be suitably used as a light source for vehicle headlights.

[0037] It is known that when manufacturing light-emitting elements such as LEDs and laser diodes, if a compound semiconductor layer with a different coefficient of thermal expansion than the substrate is formed on the substrate, the resulting light-emitting element will warp. For example, when a semiconductor layer such as gallium nitride (GaN) is formed on a sapphire substrate, the difference in the coefficients of thermal expansion between the substrate and the semiconductor layer causes warping in the individual light-emitting elements, where the central part is convex toward the semiconductor layer. For this reason, light-emitting elements 20 with a large aspect ratio (i.e., a large ratio of the long side to the short side) tend to have the central part in the longitudinal direction convex toward the semiconductor layer relative to both ends in the longitudinal direction. Furthermore, the effect of warping increases as the length of the long side increases.

[0038] If the light-emitting element 20 has a curvature that is convex toward the semiconductor layer, a light-emitting element 20 with a large aspect ratio will have a larger curvature, with both sides in the longitudinal direction curving away from the substrate 10 relative to the center in the longitudinal direction. Therefore, in the light-emitting device 1, the upper surface 20a of the light-emitting element 20 is made into a rectangle with a smaller aspect ratio than the upper surface 61 of the light-transmitting member 60. By making the aspect ratio of the upper surface 20a of the light-emitting element 20 smaller than that of the upper surface 61 of the light-transmitting member 60, the curvature of the light-emitting element 20 can be reduced compared to the case where it has the same aspect ratio as the upper surface 61 of the light-transmitting member 60. On the other hand, by making the upper surface 61 of the light-transmitting member 60 into a rectangle with a larger aspect ratio than the upper surface 20a of the light-emitting element 20, a light-emitting surface with a desired aspect ratio (for example, a horizontally elongated rectangle suitable for the low beam of a headlight) can be made. By making the translucent member 60 a convex shape as shown in Figures 8 and 9, the shape of the upper surface 61 of the translucent member 60 can be changed, making it easier to realize a light-emitting device having a light-emitting surface with a desired aspect ratio.

[0039] Furthermore, since the upper surface 20a of the light-emitting element 20 is rectangular, the tendency for both sides in the longitudinal direction to warp away from the substrate 10 remains unchanged. Therefore, the light-emitting device 1 includes a plurality of first bumps 40a arranged in a first region R1 including the imaginary line V, a plurality of second bumps 40b arranged in a second region R2, and a plurality of third bumps 40c arranged in a third region R3. The number of second bumps 40b and third bumps 40c is greater than the number of first bumps 40a, and the first bumps 40a, second bumps 40b, and third bumps 40c are arranged symmetrically with respect to the imaginary line V in a top view. In other words, more bumps are arranged on both sides in the longitudinal direction of the light-emitting element 20, where the warping is greater. This allows the light-emitting element 20 to be bonded to the substrate 10 while correcting the warping of the light-emitting element 20 by pressing during bonding. Although stress due to warping correction remains after bonding, by placing more bumps on both sides in the longitudinal direction, the effect of stress on each bump can be reduced, and the bonding strength between the substrate 10 and the light-emitting element 20 can be improved. This arrangement of bumps is particularly effective for relatively large light-emitting elements where the aspect ratio of the upper surface 20a of the light-emitting element 20 is rectangular (1:2 to 1:4) and the length of the long side of the upper surface 20a is 1000 μm to 3000 μm, as these elements tend to exhibit greater warping.

[0040] As described above, the light-emitting element 20 has a tendency to bend in the direction away from the substrate 10 (i.e., the Z direction) on both sides in the longitudinal direction of the light-emitting element 20. For this reason, in the light-emitting device 1, the light-emitting element 20 is flip-chip mounted on the substrate 10 such that the gap between the first wiring 12a and the second wiring 12b is located on the central side in the longitudinal direction of the light-emitting element 20. When the light-emitting device 1 is equipped with a covering member 70, as shown in Figure 2, the thickness of the covering member 70 positioned between the lower surface 20b of the light-emitting element 20 and the substrate 10 is greater for the covering member 70 positioned on the gap between the first wiring 12a and the second wiring 12b than for the covering member 70 positioned on the first wiring 12a and the second wiring 12b. For this reason, by positioning the gap between the first wiring 12a and the second wiring 12b on the central side in the longitudinal direction of the light-emitting element 20, the stress on both sides in the longitudinal direction of the light-emitting element 20 that tries to lift the light-emitting element 20 in the Z direction due to the expansion of the covering member 70 can be reduced compared to the stress on the central side in the longitudinal direction. This makes it possible to improve the bonding strength between the light-emitting element 20 and the substrate 10.

[0041] Furthermore, when the light-emitting element 20 is flip-chip mounted on the first wiring 12a and the second wiring 12b, the gap between the first wiring 12a and the second wiring 12b is located on the central side in the longitudinal direction of the light-emitting element 20. As a result, the current density on the central side becomes higher, and when the light-emitting element 20 is illuminated, the sides in the longitudinal direction tend to be darker, while the central side tends to be brighter. Therefore, in this embodiment, the bump density located on the central side in the longitudinal direction of the light-emitting element is reduced, and the bump density on both sides in the longitudinal direction is increased, thereby increasing the current density flowing on both sides in the longitudinal direction. This reduces the decrease in brightness on both sides in the longitudinal direction, making it possible to realize a light-emitting device with less brightness unevenness.

[0042] The light-emitting device 1 can be used, for example, in the headlights of an automobile. The light-emitting device 1, with its rectangular light-emitting surface, can be suitably adopted in automobiles equipped with the horizontally elongated headlights that are a recent trend. That is, by arranging the longitudinal direction of the light-emitting device 1 to correspond to the left-right direction of the headlight's light distribution pattern, it is possible to illuminate a wider area of ​​the road surface in the left-right direction compared to a light-emitting device with a square light-emitting surface or a light-emitting device with a rectangular light-emitting surface that has a relatively small aspect ratio. In addition, it is possible to brightly illuminate the road surface far from the vehicle, and the road surface close to the vehicle is less likely to be illuminated more brightly than necessary, thereby reducing the occurrence of glare due to road surface reflection.

[0043] The following describes in detail each element constituting the light-emitting device 1 according to the embodiment.

[0044] (Circuit board 10) The substrate 10 is a component on which the light-emitting element 20 is arranged. The base material 11 is, for example, a roughly rectangular parallelepiped or roughly cubic shape. It is preferable to use a material for the base material 11 that is an insulating material and does not easily transmit light emitted from the light-emitting element 20 or ambient light. Examples of materials for the base material 11 include ceramics such as aluminum oxide, aluminum nitride, silicon nitride, and mullite; resins such as epoxy resin, silicone resin, modified epoxy resin, urethane resin, phenolic resin, polyimide resin, BT resin, and polyphthalamide; semiconductors such as silicon; and single materials and composite materials thereof of metals such as copper and aluminum. Among these, ceramics with excellent heat dissipation properties can be suitably used as the material for the base material 11.

[0045] The first wiring 12a and the second wiring 12b, which constitute wiring 12, are electrically connected to the light-emitting element 20 and the protective element 30. Of the third wiring 13a, fourth wiring 13b, fifth wiring 13c, and sixth wiring 13d, which constitute wiring 13, any two are the anode electrode and cathode electrode connected to an external power supply, and the other two are heat dissipation terminals electrically independent from the anode electrode and cathode electrode. Wiring 13 does not necessarily have to include heat dissipation terminals. One of the anode electrode and cathode electrode is connected to the first wiring 12a via relay wiring provided inside and / or on the side of the substrate 11, and the other is connected to the second wiring 12b.

[0046] Wiring 12 and wiring 13 can be made of metals such as iron, copper, nickel, aluminum, gold, silver, platinum, titanium, tungsten, palladium, or alloys containing at least one of these. The outermost surface of wiring 12 and wiring 13 is preferably gold. The thickness of wiring 12 and wiring 13 is, for example, about 50 μm.

[0047] The substrate 10 does not necessarily have wiring 13. In this case, an anode electrode and a cathode electrode electrically connected to an external power supply may be arranged on the top or side surface. The substrate 10 may have a recess on its top surface. In this case, the light-emitting device 1 may have a structure in which the light-emitting element 20 is arranged at the bottom of the recess of the substrate 10.

[0048] Furthermore, the substrate 10 may use leads (specifically, thin metal plates) as wiring. In this case, the substrate 10 has leads as wiring and a resin molded body that holds the leads as a base material. The leads can be those that have been processed into a predetermined shape using the aforementioned metal or alloy by rolling, punching, extrusion, etching by wet or dry etching, or a combination thereof.

[0049] (Bump 40) The bump 40 includes a first bump 40a, a second bump 40b, and a third bump 40c. The shape and size of the multiple bumps 40 can be set as appropriate. For example, the multiple bumps 40 can be circles or ellipses, triangles, quadrilaterals, hexagons, and other polygons in a plan view, with circles or ellipses being preferred. The size can be adjusted as appropriate depending on the size of the semiconductor laminate, the required light emission output of the light-emitting element, etc. For example, a diameter of several tens of micrometers to several hundred micrometers can be used. The first bump 40a, the second bump 40b, and the third bump 40c may all or part be the same shape and / or size, or they may have different shapes and / or sizes. Also, the first bump 40a may all or part be the same shape and / or size as the second bump 40b and the third bump 40c, or they may have different shapes and / or sizes. In the light-emitting device 1, the number of second bumps 40b and third bumps 40c is greater than the number of first bumps 40a. In the light-emitting device 1, the second bumps 40b and third bumps 40c are arranged symmetrically with respect to the imaginary line V of the light-emitting element 20. For example, gold, silver, copper, aluminum, tin, platinum, zinc, nickel, or alloys thereof can be used for the bumps 40.

[0050] (Light-emitting element 20) The light-emitting element 20 can preferably be a semiconductor light-emitting element such as a light-emitting diode (LED) chip or a semiconductor laser (LD) chip. Specific examples of the light-emitting element 20 are shown in Figures 10 and 11. Figure 10 is a schematic bottom view showing the light-emitting element constituting the light-emitting device according to this embodiment. In Figure 10, for convenience, the position where the element electrode 24 contacts the bump 40 is shown by a dashed line. Figure 11 is a cross-sectional view taken along the line XI-XI in Figure 10. As shown in Figures 10 and 11, the light-emitting element 20 may include a support substrate 21, a semiconductor laminate 22, an insulating film 23, and an element electrode 24.

[0051] The support substrate 21 can be, for example, a substrate on which a semiconductor layer can be epitaxially grown as a growth substrate for a semiconductor layer. Examples of materials for such a growth substrate include insulating substrates such as sapphire (Al2O3) and spinel (MgA12O4). The light-emitting element 20 does not necessarily have to be provided with a support substrate 21.

[0052] The semiconductor laminate 22 includes a first semiconductor layer 22a, a second semiconductor layer 22b, and an active layer 22c located between the first semiconductor layer 22a and the second semiconductor layer 22b. The semiconductor laminate 22 further has a plurality of exposed portions 22x on the inner side of the outer periphery of the second semiconductor layer 22b, where the second semiconductor layer 22b and the active layer 22c are removed along the entire thickness direction, and the first semiconductor layer 22a is exposed from the second semiconductor layer 22b and the active layer 22c.

[0053] In the semiconductor stack 22, the first semiconductor layer 22a is, for example, an n-type semiconductor layer, and the active layer 22c and the second semiconductor layer 22b are, for example, p-type semiconductor layers. Examples of semiconductors for the first semiconductor layer 22a, the active layer 22c, and the second semiconductor layer 22b include various semiconductors such as III-V compound semiconductors and II-VI compound semiconductors. Specifically, In X Al Y Ga 1-X-Y Examples of nitride-based semiconductor materials include N(0≦X, 0≦Y, X+Y≦1), and materials such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN can be used. The thickness and layer structure of each layer can be those known in the art.

[0054] The insulating film 23 covers the surface of the semiconductor laminate 22 on the side of the second semiconductor layer 22b, and has a first opening 23x on the element electrode 24 side of a portion of the second semiconductor layer 22b, and a second opening 23y on the element electrode 24 side of the exposed portion 22x. The insulating film 23 is made of a material known in the art, in a material and thickness that can ensure electrical insulation. Specifically, metal oxides and metal nitrides can be used for the insulating film 23, and for example, at least one oxide or nitride selected from the group consisting of Si, Ti, Zr, Nb, Ta, and Al can be suitably used. The insulating film 23 can be formed by methods such as sputtering or vapor deposition.

[0055] The element electrode 24 is positioned on the lower surface 20b side of the light-emitting element 20. Specifically, the element electrode 24 is positioned on the -Z side of the semiconductor laminate 22. The element electrode 24 includes a first element electrode 24a, a second element electrode 24b, and a third element electrode 24c. The first element electrode 24a is connected to the second semiconductor layer 22b, and the second element electrode 24b and the third element electrode 24c have the same polarity and are each connected to the first semiconductor layer 22a. The first element electrode 24a is positioned in the first region R1 shown in Figure 6, the second element electrode 24b is positioned in the second region R2 shown in Figure 6, and the third element electrode 24c is positioned in the third region R3 shown in Figure 6. In the example shown in Figure 10, the second element electrode 24b and the third element electrode 24c are positioned in a continuous line surrounding the first element electrode 24a.

[0056] In detail, the first element electrode 24a is electrically connected to the second semiconductor layer 22b at a first opening 23x, and a portion of it is located on the -Z side of the second semiconductor layer 22b via an insulating film 23. The second element electrode 24b and the third element electrode 24c are electrically connected to the first semiconductor layer 22a at a second opening 23y, and a portion of them is located on the -Z side of the second semiconductor layer 22b via an insulating film 23. The first element electrode 24a, the second element electrode 24b, and the third element electrode 24c have a first surface 24x, a second surface 24y, and a third surface 24z, which are located at the same height as the second semiconductor layer 22b.

[0057] In this embodiment, it is preferable that the bumps are connected to the first surface 24x of the first element electrode 24a, the second surface 24y of the second element electrode 24b, and the third surface 24z of the third element electrode 24c. This ensures that the load when the light-emitting element 20 is flip-chip mounted is applied to the first bump 40a, the second bump 40b, and the third bump 40c in approximately equal proportions, thereby reducing the load imbalance on the first and second semiconductor layers during mounting. As a result, stable flip-chip mounting becomes possible.

[0058] The element electrode 24 can be formed by methods such as sputtering or vapor deposition. The element electrode 24 can be composed of a single layer or multilayer film of a metal or alloy thereof, such as Au, Pt, Pd, Rh, Ni, W, Mo, Cr, Ti, Al, Cu, etc. Specifically, the element electrode 24 can be composed of a multilayer film such as Ti / Rh / Au, Ti / Pt / Au, W / Pt / Au, Rh / Pt / Au, Ni / Pt / Au, Al-Cu alloy / Ti / Pt / Au, Al-Si-Cu alloy / Ti / Pt / Au, or Ti / Rh from the semiconductor layer side. From the viewpoint of simplifying the manufacturing process, it is preferable that the first element electrode 24a, the second element electrode 24b, and the third element electrode 24c are composed of the same material.

[0059] The light-emitting element 20 may further include a light-reflective electrode 28 interposed between the first element electrode 24a and the second semiconductor layer 22b, and a protective layer 29 covering the light-reflective electrode 28. The first semiconductor layer 22a and the second semiconductor layer 22b and the element electrode 24 may be in direct contact, or they may be electrically connected via a conductive layer such as the light-reflective electrode 28.

[0060] The light-reflective electrode 28 can be made of a metallic material that has both conductivity and light reflectivity. For example, Ag, Al, Ti, Pt, or an alloy mainly composed of any of these metals can be used. Among these, Ag or an Ag alloy that has high light reflectivity to light emitted from the active layer is more preferred. If the light-reflective electrode 28 contains Ag, it is preferable that the protective layer 29 covers all of the top and side surfaces of the light-reflective electrode 28 in order to prevent Ag migration.

[0061] The protective layer 29 may be formed from conductive materials such as metals and alloys commonly used as electrode materials, or it may be formed from an insulating material. Examples of conductive materials include single-layer or multilayer films containing metals such as Al, Cu, and Ni. Examples of insulating materials include materials similar to those used for the insulating film 23 described above.

[0062] Furthermore, the light-emitting element 20 may include a transparent conductive film such as ITO (Indium Tin Oxide), ZnO (Zinc Oxide), or In2O3 (Indium Oxide) between the second semiconductor layer 22b and the light-reflective electrode 28, from the viewpoint of reducing unevenness in the current density distribution.

[0063] The light-emitting element 20 may have an optical thin film such as an anti-reflective film on its upper surface, or an optical film such as a reflective film on its side surface, in order to improve light extraction.

[0064] (Protection element 30) The light-emitting device 1 may include other electronic components besides the light-emitting element 20, such as a protective element 30. The protective element 30 is, for example, a Zener diode. However, the light-emitting device 1 may also be configured without the protective element 30.

[0065] (Jointing member 50) As described above, the bonding member 50 is light-transmitting and guides the light emitted from the light-emitting element 20 to the light-transmitting member 60. By covering the side surface 20c of the light-emitting element 20 with the bonding member 50, it becomes easier to guide the light emitted from the side surface 20c of the light-emitting element 20 to the light-transmitting member 60, thereby improving the light extraction efficiency in the light-emitting device 1. The bonding member 50 is positioned to cover the top surface 20a and each of the side surfaces 20c of the light-emitting element 20.

[0066] As the bonding member 50, for example, a translucent resin can be used. Examples of translucent resins include thermosetting resins such as epoxy resin, modified epoxy resin, silicone resin, and modified silicone resin. Among these, silicone resin, which has high heat resistance, is preferably used. When using silicone resin for the bonding member 50, dimethyl silicone resin or phenylmethyl silicone resin may be used. Since phenylmethyl silicone resin has a higher refractive index than dimethyl silicone resin, it can improve the light extraction efficiency of the light-emitting device 1. Alternatively, a silicon alcoholate such as polysilazane, which has better heat resistance, may be used as the bonding member 50. The bonding member 50 may or may not contain light-scattering particles such as silicon dioxide, titanium dioxide, aluminum oxide, or barium titanate.

[0067] (Translucent member 60) The light-transmissive member 60 is disposed on the light-emitting element 20 and transmits the light emitted from the light-emitting element 20 to the outside. The light-transmissive member 60 transmits 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 in the wavelength range of 320 nm to 850 nm), and preferably transmits 70% or more of the light. The light-transmissive member 60 may be composed of, for example, an inorganic material such as glass, ceramic, sapphire, etc., or an organic material such as a resin containing one or more of silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, phenolic resin, fluororesin, or a hybrid resin. The light-transmissive member 60 may contain a phosphor capable of wavelength-converting at least a part of the incident light. Examples of the light-transmissive member 60 containing a phosphor include a sintered body of a phosphor and a material obtained by containing phosphor powder in the above-described material. Further, the light-transmissive member 60 may be one in which a phosphor layer such as a resin layer containing a phosphor or a glass layer containing a phosphor is disposed on the surface of a light-transmissive plate which is a molded body of resin, glass, ceramic, etc. Further, the light-transmissive member 60 may contain a filler such as light-scattering particles according to the purpose. When containing a filler such as light-scattering particles, the light-transmissive member 60 may be one obtained by containing a filler in resin, glass, ceramic or other inorganic substances. Alternatively, the light-transmissive member 60 may be one in which a light-scattering layer such as a resin layer containing a filler such as light-scattering particles or a glass layer containing a filler is disposed on the surface of a light-transmissive plate which is a molded body of resin, glass, ceramic, etc.

[0068] 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 phosphors (e.g., 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) and other 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) and other nitride phosphors, KSF phosphors (e.g., K2SiF6:Mn), KSAF phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1.), or fluoride phosphors such as MGF phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2) can be used.

[0069] As the light scattering particles, the same light scattering particles as those exemplified in the joining member 50 can be used.

[0070] When a resin is used as the binder for the phosphor layer or the light scattering layer, examples of the resin include thermosetting resins such as epoxy resins, modified epoxy resins, silicone resins, and modified silicone resins.

[0071] ]]Furthermore, in order to improve light extraction, the light-transmitting member 60 may have an optical thin film such as an anti-reflective film on its upper and / or lower surface, and may also have an optical film such as a reflective film on its side surface.

[0072] (Covering member 70) The coating member 70 preferably has a reflectance of 60% or more with respect to light emitted from the light-emitting element 20, and more preferably has a reflectance of 70% or more, 80% or more, or 90% or more. It is preferable to use an insulating material for the coating member 70. The coating member 70 is, for example, a member containing particles of a light-reflective substance and a base material. Examples of base materials used for the coating member 70 include resins or hybrid resins containing one or more of the following: silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, acrylic resin, phenolic resin, bismaleimidotriazine resin, and polyphthalamide resin. Among these, it is particularly preferable to use a silicone resin that has excellent light resistance, heat resistance, electrical insulation properties, and flexibility. The base material may also be composed of an inorganic material such as an alkali metal silicate. Examples of light-reflecting materials include titanium oxide, silicon oxide, aluminum oxide, zirconium oxide, magnesium oxide, potassium titanate, barium titanate, zinc oxide, silicon nitride, aluminum nitride, boron nitride, calcium carbonate, calcium hydroxide, calcium silicate, and combinations thereof. Among these, titanium oxide, which has a relatively high refractive index, is preferred from the viewpoint of light reflection. The coating member 70 may be composed of a single member or of multiple members.

[0073] <Method for manufacturing a light-emitting device according to an embodiment> A method for manufacturing a light-emitting device according to an embodiment may include, for example, the steps of preparing a light-emitting element, preparing a wiring board, arranging a light-emitting element on the wiring board, arranging a bonding member, preparing a light-transmitting member, curing the bonding member, and arranging a covering member.

[0074] The following describes each manufacturing process that may be included in the manufacturing method of the light-emitting device according to the embodiment.

[0075] (Process for preparing the light-emitting element) First, a light-emitting element 20 is prepared, which has an upper surface 20a, a lower surface 20b, and a plurality of side surfaces 20c connected to the upper surface 20a and the lower surface 20b, and has element electrodes 24 including a first element electrode 24a, a second element electrode 24b, and a third element electrode 24c on the lower surface 20b side. In addition, a protective element 30 is prepared as needed. The light-emitting element 20 can be prepared by going through some or all of a plurality of steps, such as a step of forming a semiconductor laminate and a step of forming electrodes. In the description of the manufacturing method, "prepare" a component is not limited to manufacturing the component, but also includes acquiring the component by purchasing it, receiving the component, etc.

[0076] (Process of preparing the wiring board, process of arranging light-emitting elements on the wiring board) Next, the substrate 10 is prepared, and the light-emitting element 20 is placed on the substrate 10. Specifically, first, the substrate 10 is prepared, which has a base material 11, wiring 12 provided on the upper surface 11a of the base material 11, and wiring 13 provided on the lower surface 11b of the base material 11. Then, the light-emitting element 20 is placed on the upper side of the substrate 10. Here, a protective element 30 is placed together with the light-emitting element 20. The light-emitting element 20 and the protective element 30 are flip-chip mounted on the substrate 10.

[0077] Specifically, first, a plurality of bumps 40, including a first bump 40a, a second bump 40b, and a third bump 40c, are placed on the wiring 12 of the substrate 10 at the positions shown in Figure 7. The plurality of bumps 40 can be formed, for example, by stud bumps known in the art. Stud bumps can be formed by a stud bump bonder, wire bonding apparatus, etc. Alternatively, the bumps 40 may be formed by methods known in the art, such as electroplating, electroless plating, vapor deposition, sputtering, etc. The plurality of bumps 40 are, for example, gold bumps. At this point, each bump 40 is not elliptical in plan view, but for example, circular in plan view. Next, the light-emitting element 20 is placed on the substrate 10 such that the first element electrode 24a, second element electrode 24b, and third element electrode 24c of the light-emitting element 20 are in contact with the first bump 40a, second bump 40b, and third bump 40c, respectively. Next, for example, the light-emitting element 20 is heated while being pressed against the substrate 10, and ultrasonic vibrations are applied in the longitudinal direction of the upper surface 20a of the light-emitting element 20, thereby electrically and mechanically joining the substrate 10 and the light-emitting element 20 via a plurality of bumps 40. Due to the pressing during joining, the light-emitting element 20 is joined to the substrate 10 in a state where its warping is corrected. Also, due to the pressing during joining, the bumps 40 are crushed, and when viewed from above, they take on an elliptical shape with the major axis in the direction in which the long side of the upper surface 20a of the light-emitting element 20 extends. Furthermore, by arranging a plurality of bumps 45, the substrate 10 and the protective element 30 can be electrically and mechanically joined via a plurality of bumps 45 in the same manner as described above.

[0078] (Step of arranging the joining members) Next, an uncured bonding member is placed on the upper surface 20a of the light-emitting element 20 using a nozzle or the like. The uncured bonding member, upon curing, constitutes a bonding member 50 that joins the light-transmitting member 60 and the light-emitting element 20 in the light-emitting device 1. The material described above can be used as the material for the bonding member 50 as the uncured bonding member. Note that "uncured" refers to the state before the curing reaction proceeds, that is, the state before any operation is performed to advance the curing reaction. Operations to advance the curing reaction include heating or light irradiation. Note that the curing reaction may proceed slightly before any operation is performed to advance the curing reaction, but the uncured state includes such a state.

[0079] (Process of preparing light-transmitting material) Next, a translucent member 60 with a convex shape that protrudes toward the upper surface 61 is prepared, for example, as shown in Figure 8. Then, the translucent member 60 is placed on the upper surface 20a of the light-emitting element 20 via the uncured bonding member. The lower surface 62 of the translucent member 60 is in contact with the uncured bonding member.

[0080] (Process for hardening the joining members) Next, the bonding member is pressed against the light-emitting element 20 side on the lower surface 62 of the translucent member 60 to cure the uncured bonding member. This forms the bonding member 50, and the translucent member 60 and the light-emitting element 20 are bonded together via the bonding member 50. Curing can be performed by known methods, such as heating in an oven. The bonding member 50 covers at least the entire area of ​​the lower surface 62 of the translucent member 60 that faces the upper surface 20a of the light-emitting element 20. Furthermore, it is preferable that the bonding member 50 covers a larger area of ​​the lower surface 62 of the translucent member 60.

[0081] (Step of arranging the covering material) Next, the upper surface 61 of the translucent member 60 is exposed, and a covering member 70 is placed to cover the side surface of the translucent member 60 and the side surface 20c of the light-emitting element 20. Specifically, an uncured covering member is placed on the substrate 10. The uncured covering member can be placed on the substrate 10 by, for example, potting. Alternatively, the resin can be placed by compression molding, transfer molding, etc. After that, the uncured covering member is cured. This places the covering member 70, and the light-emitting device 1 is obtained. If necessary, the height of the formed covering member 70 may be adjusted by cutting the upper surface, or the upper surface of the covering member 70 may be processed into a desired shape.

[0082] Furthermore, the manufacturing method of the light-emitting device according to this embodiment allows for the simultaneous manufacture of multiple light-emitting devices 1. In this case, in the step of preparing the wiring board, a composite substrate is prepared that includes multiple regions which will become the substrates 10 of each individual light-emitting device 1 after individualization. Then, the light-emitting elements 20 and protective elements 30 are placed in each region of the prepared composite substrate, and after the above-described steps, an individualization step is performed to separate each region, thereby obtaining the light-emitting device 1 shown in Figure 1.

[0083] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0084] In addition to the embodiments described above, the following further notes are disclosed. (Note 1) A substrate having a base material and wiring disposed on the upper surface of the base material, A single light-emitting element is flip-chip mounted on the aforementioned wiring via a plurality of bumps, It comprises a light-transmitting member disposed on the light-emitting element, The upper surface of the light-transmitting member is a rectangle with an aspect ratio of 1:3 or more and 1:5 or less, where the ratio of the short side to the long side is 1:3 or more. The upper surface of the light-emitting element is a rectangle with a smaller aspect ratio than the upper surface of the light-transmitting member. The plurality of bumps include, in a top view, a plurality of first bumps arranged in a first region that includes a virtual line passing through the midpoints of the two long sides of the upper surface of the light-emitting element; a plurality of second bumps arranged in a second region adjacent to one side of the first region in the direction in which the long sides extend; and a plurality of third bumps arranged in a third region adjacent to the other side of the first region in the direction in which the long sides extend. The number of the second bump and the number of the third bump are greater than the number of the first bump. The first bump, the second bump, and the third bump are arranged symmetrically with respect to the imaginary line in a top view, in a light-emitting device. (Note 2) The light-emitting device as described in Appendix 1, wherein the upper surface of the light-emitting element is a rectangle with an aspect ratio of 1:2 or more and 1:4 or less. (Note 3) The light-emitting device according to Appendix 1 or 2, wherein the length of the long side of the upper surface of the light-emitting element is 1000 μm or more and 3000 μm or less. (Note 4) The light-emitting device according to any one of appendices 1 to 3, wherein the area of ​​the upper surface of the light-transmitting member is smaller than the area of ​​the lower surface. (Note 5) The light-emitting device according to Appendix 4, wherein the aspect ratio of the upper surface of the light-transmitting member is greater than the aspect ratio of the lower surface of the light-transmitting member. (Note 6) The light-emitting device according to Appendix 4 or 5, wherein the aspect ratio of the lower surface of the light-transmitting member is the same as the aspect ratio of the upper surface of the light-emitting element. (Note 7) The light-transmitting member includes a lower surface which is the opposite surface to the upper surface, a first side surface which is connected to the upper surface, and a second side surface which is connected to the lower surface. The light-emitting device according to any one of appendices 4 to 6, wherein the long side of the upper surface of the light-emitting element is located between the first side and the second side when viewed from above. (Note 8) The light-emitting device according to Appendix 7, wherein the light-transmitting member includes a second upper surface located between the first side surface and the second side surface, and the height from the lower surface to the second upper surface is lower than the height from the second upper surface to the upper surface. (Note 9) The light-emitting element includes a semiconductor laminate comprising a first semiconductor layer, a second semiconductor layer, and an active layer located between the first and second semiconductor layers, and an element electrode disposed on the lower surface of the semiconductor laminate and comprising a first element electrode located in the first region, a second element electrode located in the second region, and a third element electrode located in the third region. The light-emitting device according to any one of appendices 1 to 8, wherein the first element electrode is connected to the first semiconductor layer, and the second element electrode and the third element electrode are connected to the second semiconductor layer. (Note 10) The light-emitting device according to any one of appendices 1 to 9, wherein the plurality of bumps include a plurality of bumps arranged in a row parallel to the imaginary line when viewed from above. (Note 11) The light-emitting device according to any one of appendices 1 to 10, wherein the bump has an elliptical shape in a top view, with its major axis in the direction in which the long side extends. (Note 12) The light-emitting device according to any one of appendices 1 to 11, further comprising a covering member that exposes the upper surface of the light-transmitting member and covers the side surface of the light-transmitting member and the side surface of the light-emitting element. (Note 13) The wiring includes a first wiring connected to the first bump, and a second wiring connected to the second bump and / or the third bump. The light-emitting device according to Appendix 12, wherein the covering member covers the upper surface of the substrate that is exposed from the first wiring and the second wiring. (Note 14) The light-emitting device according to any one of appendices 1 to 13, further comprising a joining member for joining the light-transmitting member and the light-emitting element. [Explanation of symbols]

[0085] 1. Light-emitting device 10 circuit boards 11 Base material 11a Top surface 11b Bottom side 12 Wiring 12a First wiring 12b Second wiring 13 Wiring 13a Third wiring 13b Fourth wiring 13c Fifth Wiring 13d Wiring No. 6 20 Light-emitting elements 20a top surface 20b Bottom side 20c side 21 Support substrate 22 Semiconductor Stacks 22a First semiconductor layer 22b Second semiconductor layer 22c active layer 22x exposed area 23 Insulating film 23x 1st opening 23y 2nd opening 24-element electrode 24a First element electrode 24b Second element electrode 24c Third Element Electrode 24x 1st surface 24y 2nd surface 24z 3rd surface 28 Light reflective electrode 29 Protective layer 30 protective elements 40,45 Bump 40a First bump 40b Second bump 40c Third Bump 50 Joining members 50c side 60 Translucent material 61 Top surface 62 Bottom surface 63a 1st side 63b Second side 64 2nd top surface 70 Covering member R1 1st area R2 2nd area R3 3rd area

Claims

1. A substrate having a base material and wiring disposed on the upper surface of the base material, A single light-emitting element is flip-chip mounted on the aforementioned wiring via a plurality of bumps, It comprises a light-transmitting member disposed on the light-emitting element, The upper surface of the light-transmitting member is a rectangle with an aspect ratio of 1:3 or more and 1:5 or less, where the ratio of the short side to the long side is 1:3 or more. The upper surface of the light-emitting element is a rectangle with a smaller aspect ratio than the upper surface of the light-transmitting member. The plurality of bumps include, in a top view, a plurality of first bumps arranged in a first region that includes a virtual line passing through the midpoints of the two long sides of the upper surface of the light-emitting element; a plurality of second bumps arranged in a second region adjacent to one side of the first region in the direction in which the long sides extend; and a plurality of third bumps arranged in a third region adjacent to the other side of the first region in the direction in which the long sides extend. The number of the second bump and the number of the third bump are greater than the number of the first bump. The first bump, the second bump, and the third bump are arranged symmetrically with respect to the imaginary line in a top view, in a light-emitting device.

2. The light-emitting device according to claim 1, wherein the upper surface of the light-emitting element is a rectangle with an aspect ratio of 1:2 or more and 1:4 or less.

3. The light-emitting device according to claim 1 or 2, wherein the length of the long side of the upper surface of the light-emitting element is 1,000 μm or more and 3,000 μm or less.

4. The light-emitting device according to claim 1 or 2, wherein the area of ​​the upper surface of the light-transmitting member is smaller than the area of ​​the lower surface.

5. The light-emitting device according to claim 4, wherein the aspect ratio of the upper surface of the light-transmitting member is greater than the aspect ratio of the lower surface of the light-transmitting member.

6. The light-emitting device according to claim 4, wherein the aspect ratio of the lower surface of the light-transmitting member is the same as the aspect ratio of the upper surface of the light-emitting element.

7. The light-transmitting member includes a lower surface which is the opposite surface to the upper surface, a first side surface which is connected to the upper surface, and a second side surface which is connected to the lower surface. The light-emitting device according to claim 4, wherein the long side of the upper surface of the light-emitting element is located between the first side and the second side when viewed from above.

8. The light-emitting device according to claim 7, wherein the light-transmitting member includes a second upper surface located between the first side surface and the second side surface, and the height from the lower surface to the second upper surface is lower than the height from the second upper surface to the upper surface.

9. The light-emitting element includes a semiconductor laminate comprising a first semiconductor layer, a second semiconductor layer, and an active layer located between the first and second semiconductor layers, and an element electrode disposed on the lower surface of the semiconductor laminate and comprising a first element electrode located in the first region, a second element electrode located in the second region, and a third element electrode located in the third region. The light-emitting device according to claim 1 or 2, wherein the first element electrode is connected to the first semiconductor layer, and the second element electrode and the third element electrode are connected to the second semiconductor layer.

10. The light-emitting device according to claim 1 or 2, wherein the plurality of bumps include a plurality of bumps arranged in rows parallel to the imaginary line when viewed from above.

11. The light-emitting device according to claim 1 or 2, wherein the bump has an elliptical shape in a top view, with its major axis in the direction in which the long side extends.

12. The light-emitting device according to claim 1 or 2, further comprising a covering member that exposes the upper surface of the light-transmitting member and covers the side surface of the light-transmitting member and the side surface of the light-emitting element.

13. The wiring includes a first wiring connected to the first bump, and a second wiring connected to the second bump and / or the third bump. The light-emitting device according to claim 12, wherein the covering member covers the upper surface of the substrate that is exposed from the first wiring and the second wiring.

14. The light-emitting device according to claim 1 or 2, further comprising a joining member for joining the light-transmitting member and the light-emitting element.

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