Light emitting device and method for manufacturing the same

Abstract

To improve optical coupling efficiency between a light emitting device and a light guide plate.SOLUTION: A light emitting device 101 includes: a first light emitting element 10 and a second light emitting element 20 arranged along an X direction; a first light-transmissive member 80 and a second light-transmissive member 90 covering the first light emitting element and the second light emitting element, respectively; and a light reflecting member 60. The first light-transmissive member and the second light-transmissive member are located on the upper surface 10a of the first light emitting element and on the upper surface 20a of the second light emitting element 20, respectively. The light reflecting member covers side faces of the first light emitting element, the second light emitting element, the first light-transmissive member and the second light-transmissive member, and includes a first portion covering first side faces of the first light emitting element, the second light emitting element, the first light-transmissive member and the second light-transmissive member, and a second portion covering second side faces thereof. The first portion has a protrusion portion 61T adjacent to an upper surface 80a of the first light-transmissive member and an upper surface 90a of the second light-transmissive member, the protrusion portion extending in the X direction.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] A liquid crystal display device displays an image using a light source such as a backlight. The backlight includes a light emitting device including an LED and a light guide plate, and the light emitted from the light emitting device is incident on a side surface of the light guide plate and is emitted in a planar form from the main surface of the light guide plate. For example, Patent Document 1 discloses an LED package used as a backlight light emitting device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-167396 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to realize a backlight with higher brightness, it is necessary to further improve the optical coupling efficiency between the light emitting device and the light guide plate. [Means for solving the problem]

[0005] A method for manufacturing a light emitting device according to an embodiment of the present disclosure includes a composite substrate having a plurality of light emitting elements, each having an emission surface having a longitudinal direction, arranged two-dimensionally with gaps in the first direction and a second direction perpendicular to the first direction, with the longitudinal direction aligned along a first direction; a plurality of translucent members arranged on the emission surfaces of the plurality of light emitting elements; and a light reflective member arranged between the plurality of light emitting elements and the plurality of translucent members so as to cover at least side surfaces of the plurality of light emitting elements and side surfaces of the plurality of translucent members, the light reflective member including a pair of first portions positioned outside two light emitting elements and two translucent members adjacent to each other in the second direction in the second direction, and a second portion positioned between the two light emitting elements and the two translucent members, the pair of first portions being the second portion having a third upper surface, and the light-transmitting member having a third upper surface, and a step (B) of grinding at least a part of the pair of first portions and the second portion of the light-reflective member and the light-transmitting members of the two light-emitting elements from the exposed first upper surface, second upper surface, and third upper surface to form a convex portion having the first upper surface and extending along the first direction in the first portion, a fourth upper surface in the second portion that is located lower than the first upper surface, and a fifth upper surface in the light-transmitting members of the two light-emitting elements that is located lower than the first upper surface and is at the same height as the fourth upper surface or lower than the fourth upper surface. Effect of the Invention

[0006] According to the embodiments of the present disclosure, a light emitting device with improved optical coupling efficiency to a light guide plate can be provided. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a light emitting device according to a first embodiment, seen from above. [Diagram 2]FIG. 2 is a perspective view of the light emitting device shown in FIG. 1 as viewed from below. [Diagram 3] FIG. 3 is a front view of the light emitting device shown in FIG. [Figure 4] FIG. 4 is a rear view of the light emitting device shown in FIG. [Diagram 5] FIG. 5 is a bottom view of the light emitting device shown in FIG. [Figure 6] FIG. 6 is a right side view of the light emitting device shown in FIG. [Figure 7] 7 is a cross-sectional view of the light emitting device taken along line VII-VII shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view of the light emitting device taken along line VIII-VIII shown in FIG. [Figure 9] FIG. 9 is a schematic side view showing a part of a backlight in which the light emitting device of this embodiment is incorporated. [Figure 10] FIG. 10 is a flowchart showing a method for manufacturing the light emitting device according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing a part of the upper surface of the collective substrate. [Figure 12] FIG. 12 is a diagram showing a part of the lower surface of the collective substrate. [Figure 13] FIG. 13 is a plan view showing one step in a method for manufacturing a light emitting device. [Figure 14] FIG. 14 is a cross-sectional view showing one step in a method for manufacturing a light emitting device. [Figure 15] FIG. 15 is a cross-sectional view showing one step in a method for manufacturing a light emitting device. [Figure 16] FIG. 16 is a cross-sectional view showing one step in a method for manufacturing a light emitting device. [Figure 17A] FIG. 17A is a perspective view showing one step in a method for manufacturing a light emitting device. [Figure 17B] FIG. 17B is a cross-sectional view of the step shown in FIG. 17A in the method for manufacturing a light emitting device. [Figure 18A] FIG. 18A is a perspective view showing one step in a method for manufacturing a light emitting device. [Figure 18B] FIG. 18B is a cross-sectional view of the step shown in FIG. 18A in the manufacturing method of the light emitting device. [Figure 19A] FIG. 19A is a perspective view showing a step in a method for manufacturing a light emitting device. [Figure 19B] FIG. 19B is a cross-sectional view of the step shown in FIG. 19A in the method for manufacturing a light emitting device. [Figure 20A] FIG. 20A is a perspective view showing one step in a method for manufacturing a light emitting device. [Figure 20B] FIG. 20B is a cross-sectional view of the step shown in FIG. 20A in the method for manufacturing the light emitting device. [Figure 21] FIG. 21 is a perspective view of the light emitting device according to the second embodiment as viewed from above. [Figure 22] FIG. 22 is a cross-sectional view of the light emitting device shown in FIG. [Figure 23] FIG. 23 is a cross-sectional view showing a step in the method for manufacturing the light emitting device of the second embodiment. [Figure 24] FIG. 24 is a perspective view of the light emitting device according to the second embodiment as viewed from above. [Diagram 25] FIG. 25 is a cross-sectional view of the light emitting device shown in FIG. [Figure 26] FIG. 26 is a cross-sectional view showing a step in the method for manufacturing the light emitting device of the second embodiment. [Figure 27] FIG. 27 is a perspective view of a light emitting device according to another embodiment, seen from above. [Figure 28] FIG. 28 is a perspective view of the light emitting device shown in FIG. 27 as viewed from below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiments are merely examples, and the light-emitting device according to the present disclosure is not limited to the following embodiments. For example, the numerical values, shapes, materials, steps, and the order of the steps shown in the following embodiments are merely examples, and various modifications are possible as long as no technical contradictions occur. Each embodiment described below is merely an example, and various combinations are possible as long as no technical contradictions occur.

[0009] The dimensions, shapes, etc. of the components shown in the drawings may be exaggerated for clarity and may not reflect the dimensions, shapes, and size relationships between the components in an actual surface light source. In addition, in order to avoid overly complicated drawings, some elements may be omitted and shown in schematic form, or an end view showing only a cut surface may be shown as a cross-sectional view.

[0010] In the following description, components having substantially the same functions are indicated by common reference symbols, and descriptions may be omitted. In the following description, terms indicating a specific direction or position (for example, "upper", "lower", "right", "left" and other terms including these terms) may be used. However, these terms are merely used for the sake of clarity of the relative direction or position in the referenced drawings. As long as the relationship of the relative direction or position by terms such as "upper" and "lower" in the referenced drawings is the same, the arrangement may not be the same as that in the referenced drawings in drawings other than this disclosure, in actual products, manufacturing devices, etc. In this disclosure, "parallel" includes cases where two straight lines, sides, faces, etc. are in the range of about 0° to ±1°, unless otherwise specified. In addition, in this disclosure, "perpendicular" or "orthogonal" includes cases where two straight lines, sides, faces, etc. are in the range of about 90° to ±1°, unless otherwise specified.

[0011] (First embodiment)

[0012] [Structure of light emitting device 101] The light emitting device and the manufacturing method of the light emitting device of the present embodiment will be described. Figures 1 and 2 are perspective views of the light emitting device 101 according to the first embodiment of the present disclosure, as viewed from above and below. Figures 3, 4, 5, and 6 are respectively a front view, a rear view, a bottom view, and a right side view of the light emitting device 101. Figures 7 and 8 are respectively cross-sectional views of the light emitting device 101 taken along lines VII-VII and VIII-VIII shown in Figure 3.

[0013] In these figures, for reference, arrows indicating mutually orthogonal X, Y and Z directions are also shown. The X and Y directions are also referred to as a first direction and a second direction.

[0014] In addition, the relatively positive side in the Z direction is sometimes considered to be "up" or "high" and the negative side is sometimes considered to be "down" or "low" when describing the shape of a component or the positional relationship between components. For example, if a component has two faces perpendicular to the Z direction, the face located on the relatively positive side is sometimes called the top face, and the face located on the relatively negative side is sometimes called the bottom face.

[0015] The light emitting device 101 includes one or more light emitting elements. In this embodiment, as shown in FIG. 7 and FIG. 8, the light emitting device 101 includes a first light emitting element 10 and a second light emitting element 20. The first light emitting element 10 has an upper surface 10a, and the second light emitting element 20 has an upper surface 20a. The upper surface 10a and the upper surface 20a are light emitting surfaces. The upper surface 10a and the upper surface 20a have a longitudinal direction, and the first light emitting element 10 and the second light emitting element 20 are arranged in the longitudinal direction. In the illustrated example, the X direction is the longitudinal direction. Note that FIG. 8 is a cross-sectional view at the position of the first light emitting element 10, but the cross-sectional structure of the first light emitting element 10 and the cross-sectional structure of the second light emitting element 20 are the same. For this reason, for ease of understanding, in FIG. 8, the reference symbols of the structures appearing in the cross section of the second light emitting element 20 are also shown in parentheses.

[0016] The light emitting device 101 further includes a first light-transmissive member 80, a second light-transmissive member 90, and a light-reflective member 60. The first light-transmissive member 80 and the second light-transmissive member 90 are located on the upper surface 10a of the first light emitting element 10 and the upper surface 20a of the second light emitting element 20, respectively. The light-reflective member 60 covers the side surfaces of the first light emitting element 10, the second light emitting element 20, the first light-transmissive member 80, and the second light-transmissive member 90. The light emitting device 101 may further include a substrate 70 to support these components.

[0017] 1 and 2, the light emitting device 101 has, for example, a rectangular parallelepiped shape as a whole. The light emitting device 101 has a front surface 100a, a back surface 100b located opposite the front surface 100a, a top surface 100c, a bottom surface 100d, and side surfaces 100e and 100f. The bottom surface 100d is a surface that faces a substrate that supplies power to the light emitting device 101, such as a mounting substrate.

[0018] 1 and 2, the front surface 100a has a rectangular shape with a longitudinal direction along the X direction, and an upper surface 80a of the first light-transmissive member 80 and an upper surface 90a of the second light-transmissive member 90 are exposed. On the front surface 100a, the first light-transmissive member 80 and the second light-transmissive member 90 each have a longitudinal direction along the X direction, and the first light-transmissive member 80 and the second light-transmissive member 90 are arranged in the longitudinal direction.

[0019] Moreover, on the front surface 100a, the first light-transmissive member 80 and the second light-transmissive member 90 are surrounded by a light-reflective member 60.

[0020] As shown in FIG. 1 and FIG. 2, the light reflective member 60 has a convex portion 61T extending along the X direction on the top surface 100c side of the front surface 100a. As shown in FIG. 8, the convex portion 61T has an upper surface 61Ta, which is located higher than the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90. Therefore, the light that is emitted from the first light-transmissive member 80 and the second light-transmissive member 90 of the light-emitting device 101 and spreads toward the positive side of the Y direction is reflected by the convex portion 61T and travels toward the negative side of the Y direction. This makes it possible for the light emitted from the light-emitting device 101 to be incident on the side surface of the light guide plate with high optical coupling efficiency. The structure of the light-emitting device 101 will be described in detail below.

[0021] [Substrate 70] The substrate 70 is a support member on which the first light-emitting element 10 and the second light-emitting element 20 are mounted. As shown in Figures 1, 2, 7, and 8, the substrate 70 is generally rectangular in shape as a whole. In response to the first light-emitting element 10 and the second light-emitting element 20 being mounted along the X direction, the upper surface 75a of the substrate 70 typically has a rectangular shape that is longer in the X direction compared to the Y direction in the figure.

[0022] The substrate 70 includes a base material 75 having an upper surface 75a and a lower surface 75b located opposite the upper surface 75a, a first wiring 71, a second wiring 72, a third wiring 73, and a conductive member 76. The upper surface 75a of the base material 75 is the upper surface of the substrate 70, and the lower surface 75b of the base material 75 is also the lower surface of the substrate 70. The first wiring 71 and the second wiring 72 are located on the upper surface 75a and the lower surface 75b of the base material 75, respectively. The base material further has a side surface 75d that becomes part of the bottom surface 100d of the light-emitting device 101.

[0023] The base material 75 has a through hole 75h (FIG. 7) and a recess 75r (FIG. 8). The through hole 75h has openings on an upper surface 75a and a lower surface 75b of the base material 75, and is located inside the base material 75. A conductive member 76 is disposed in the through hole 75h, and the conductive member 76 is connected to the first wiring 71 on the upper surface 75a and to the second wiring 72 on the lower surface 75b. This electrically connects the first wiring 71 and the second wiring 72.

[0024] 4, 5, and 8, in this embodiment, the recess 75r is a three-dimensional space obtained by dividing a solid body consisting of a cylinder and a cone located on the upper surface of the cylinder by the axes of the cylinder and the cone. Note that the apex of the cone may not be sharp. The recess 75r has an opening on the side surface 75d and the lower surface 75b, and has a semicircular shape on the lower surface 75b and a pentagonal shape on the side surface 75d. As shown in Fig. 4, the recess 75r is not connected to the through hole 75h and is arranged separately from it.

[0025] In this embodiment, the base material 75 has three recesses 75r. The three recesses 75r are arranged symmetrically with respect to a line that passes through the center of the side surface 75d in the X direction and is perpendicular to the Z direction.

[0026] The third wiring 73 is disposed on the inner wall of the recess 75r, and the third wiring 73 and the second wiring 72 are connected on the lower surface 75b. Solder is disposed in the recess 75r and bonded to the wiring pattern of the mounting board, thereby bonding the light emitting device 101 to the mounting board at the bottom surface 100d. In addition, the wiring pattern of the mounting board is electrically connected to the first wiring 71 via the solder, the third wiring 73, the second wiring 72, and the conductive member 76.

[0027] The substrate 75 is formed of an insulating material such as resin, ceramics, or glass. The substrate 75 may be formed of a composite material such as fiber-reinforced resin, and for example, a glass epoxy substrate may be used for the substrate 75. The base material of the substrate 75 may be epoxy, bismaleimide triazine (BT), polyimide, or the like. As the ceramic, aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, or a mixture of one or more of these may be used. Of these ceramics, it is advantageous to use a material having a linear expansion coefficient close to that of the light emitting element as the material of the substrate 75.

[0028] From the viewpoint of the strength of the base material 75, the thickness of the base material 75 in the Z direction is preferably 0.05 mm or more, more preferably 0.2 mm or more. If the thickness of the base material 75 in the Z direction is 0.6 mm or less, this is advantageous for making the light emitting device thinner. The thickness of the base material 75 in the Z direction is preferably 0.5 mm or less, more preferably 0.4 mm or less.

[0029] The first wiring 71, the second wiring 72, and the third wiring 73 may be made of copper, iron, nickel, tungsten, chromium, aluminum, silver, platinum, gold, titanium, palladium, rhodium, or an alloy containing one or more of these. From the viewpoint of heat dissipation, it is preferable to use copper or a copper alloy as the material of these wirings. The first wiring 71, the second wiring 72, and the third wiring 73 may be formed on the base material 75 in the form of a single layer film, or may be formed on the base material 75 in the form of a laminated film. If the outermost surface of these wirings is formed of silver, platinum, aluminum, rhodium, or gold, or an alloy containing one or more of these, high light reflectivity and good wettability with solder, etc. can be obtained.

[0030] The conductive member 76 may be made of the same material as the first wiring 71, the second wiring 72, or the third wiring 73. The conductive member 76 may occupy the entire inside of the through hole 75h formed in the base material 75, or may be a part of the inside of the through hole 75h, for example, a conductive film disposed on the surface of the through hole 75h. Furthermore, the region surrounded by the conductive film may be filled with an insulating material such as an epoxy resin.

[0031] The substrate 70 may have an insulating layer 77. The insulating layer 77 is made of a thermosetting resin or a thermoplastic resin, and covers a portion of each of the multiple second wirings 72 located on the lower surface 75b of the base material 75. The insulating layer 77 has the effect of preventing short circuits between the second wirings 72.

[0032] [First light-emitting element 10 and second light-emitting element 20] The first light emitting element 10 and the second light emitting element 20 are semiconductor elements that emit light when supplied with a current.

[0033] As shown in FIG. 7 and FIG. 8, the first light emitting element 10 has, for example, a rectangular parallelepiped shape with a longitudinal axis along the X direction. The first light emitting element 10 has an upper surface 10a and a lower surface 10b opposite to the upper surface, each of which has a longitudinal axis along the first direction. The upper surface 10a is a main light emitting surface of the first light emitting element 10. The lower surface 10b is an electrode surface. The first light emitting element 10 further has a first side surface 10c parallel to the X direction, a second side surface 10d located opposite to the first side surface 10c, a third side surface 10e connected to the first side surface 10c and the second side surface 10d, and a fourth side surface 10f located opposite to the third side surface 10e. The first light emitting element 10 also has an electrode 11 located on the lower surface 10b.

[0034] Similarly, the second light emitting element 20 has, for example, a rectangular parallelepiped shape with a longitudinal axis along the X direction. The second light emitting element 20 has an upper surface 20a and a lower surface 20b opposite to the upper surface, each of which has a longitudinal axis along the first direction. The upper surface 20a is a main light emitting surface of the second light emitting element 20. The lower surface 20b is an electrode surface. The second light emitting element 20 further has a first side surface 20c parallel to the X direction, a second side surface 20d located opposite to the first side surface 20c, a third side surface 20e connected to the first side surface 20c and the second side surface 20d, and a fourth side surface 20f located opposite to the third side surface 20e. The second light emitting element 20 also has an electrode 21 located on the lower surface 20b.

[0035] The electrodes 11 and 21 include a pair of a positive electrode and a negative electrode. Examples of materials for the electrodes 11 and 21 include gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel, or an alloy containing one or more of these. The first light-emitting element 10 is mounted on the substrate 70 by connecting and fixing the electrode 11 to the first wiring 71 of the substrate 70 with a bonding member such as solder. Similarly, the second light-emitting element 20 is mounted on the substrate 70 by connecting and fixing the electrode 21 to the first wiring 71 of the substrate 70 with a bonding member such as solder.

[0036] Each of the first light emitting element 10 and the second light emitting element 20 further includes a semiconductor laminate. The semiconductor laminate includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer sandwiched between them. The light emitting layer may have a structure such as a double heterojunction or a single quantum well (SQW), or may have a structure having a group of active layers such as a multiple quantum well (MQW). The semiconductor laminate is configured to be capable of emitting visible light or ultraviolet light. Such a semiconductor laminate including a light emitting layer may be, for example, In x Al y Ga 1-x-y N (0≦x, 0≦y, x+y≦1).

[0037] The semiconductor laminate may have a structure including one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may have a structure in which a structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in order is repeated multiple times. When the semiconductor laminate includes multiple light-emitting layers, the semiconductor laminate may include light-emitting layers having different emission peak wavelengths, or light-emitting layers having the same emission peak wavelength. The same emission peak wavelength includes a case where the emission peak wavelength varies by about several nm. The combination of emission peak wavelengths between multiple light-emitting layers can be appropriately selected. For example, when the semiconductor laminate includes two light-emitting layers, the light-emitting layers can be selected from 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. Each light-emitting layer may include multiple active layers having different emission peak wavelengths, or multiple active layers having the same emission peak wavelength.

[0038] [First translucent member 80, second translucent member 90] The light emitting device 101 includes one or more light transmissive members. In this embodiment, the first light transmissive member 80 and the second light transmissive member 90 are generally plate-shaped members disposed above the first light emitting element 10 and above the second light emitting element 20, respectively. The first light transmissive member 80 and the second light transmissive member 90 function as protective layers for the first light emitting element 10 and the second light emitting element 20. In addition, they convert the wavelength of light emitted from the first light emitting element 10 and the second light emitting element 20, and diffuse the emitted light.

[0039] As shown in FIG. 7 and FIG. 8, the first light-transmissive member 80 has a rectangular parallelepiped shape having a longitudinal direction along the X direction, similar to the first light-emitting element 10. The first light-transmissive member 80 has an upper surface 80a and a lower surface 80b opposite to the upper surface, each having a longitudinal direction along the first direction. The upper surface 80a is an emission surface through which light emitted from the first light-emitting element 10 is emitted to the outside from the light-emitting device 101. The lower surface 80b is located on the upper surface 10a side of the first light-emitting element 10. The first light-transmissive member 80 further has a first side surface 80c parallel to the X direction, a second side surface 80d located opposite to the first side surface 80c, a third side surface 80e connected to the first side surface 80c and the second side surface 80d, and a fourth side surface 80f located opposite to the third side surface 80e.

[0040] Similarly, the second light-transmissive member 90 has a rectangular parallelepiped shape with its longitudinal axis along the X direction, similar to the second light-emitting element 20. The second light-transmissive member 90 has an upper surface 90a and a lower surface 90b opposite to the upper surface, each of which has its longitudinal axis along the first direction. The upper surface 90a is an emission surface through which light emitted from the first light-emitting element 10 is emitted to the outside from the light-emitting device 101. The lower surface 90b is located on the upper surface 10a side of the first light-emitting element 10. The second light-transmissive member 90 further has a first side surface 90c parallel to the X direction, a second side surface 90d located opposite to the first side surface 90c, a third side surface 90e connected to the first side surface 90c and the second side surface 90d, and a fourth side surface 90f located opposite to the third side surface 90e.

[0041] In this embodiment, the first light-transmissive member 80 includes a wavelength conversion section 41 and a light-transmitting section 51. The wavelength conversion section 41 is located on the upper surface 10a side of the first light-emitting element 10, and the light-transmitting section 51 is located above the wavelength conversion section 41. Similarly, the second light-transmitting member 90 includes a wavelength conversion section 42 and a light-transmitting section 52. The wavelength conversion section 42 is located on the upper surface 20a side of the second light-emitting element 20, and the light-transmitting section 52 is located above the wavelength conversion section 42. The first light-transmitting member 80 and the second light-transmitting member 90 each include the wavelength conversion section 41 and the wavelength conversion section 42, but the first light-transmitting member 80 and the second light-transmitting member 90 may not include the wavelength conversion section 41 and the wavelength conversion section 42, and may include only the light-transmitting section 51 and the light-transmitting section 52.

[0042] [Wavelength conversion units 41, 42] The wavelength conversion units 41 and 42 are each a roughly plate-shaped member, and convert the wavelength of a part of the light emitted from the first light emitting element 10 and the second light emitting element 20. The wavelength conversion units 41 and 42 contain a base material and phosphor particles dispersed in the base material. Examples of the base material of the wavelength conversion units 41 and 42 are silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenol resin, polycarbonate resin, trimethylpentene resin, polynorbornene resin, acrylic resin, urethane resin, fluororesin, or resin containing two or more of these. Glass can also be selected as the base material of the wavelength conversion units 41 and 42.

[0043] Known materials can be used as the phosphor dispersed in the wavelength conversion parts 41 and 42. The phosphor is an yttrium-aluminum-garnet phosphor (e.g., Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), CCA phosphors (e.g., Ca 10 (PO4)6Cl2:Eu), SAE phosphors (e.g., Sr4Al 14 O 25:Eu), chlorosilicate phosphors (e.g., Ca8MgSi4O 16 Cl2:Eu), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu), nitride phosphors such as SLA phosphors (e.g., SrLiAl3N4:Eu), CASN phosphors (e.g., CaAlSiN3:Eu), or SCASN phosphors (e.g., (Sr,Ca)AlSiN3:Eu), KSF phosphors (e.g., K2SiF6:Mn), KSAF phosphors (e.g., K2(Si,Al)F6:Mn), or fluoride phosphors such as MGF phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)3), or quantum dot phosphors (e.g., CdSe, InP, AgInS2, or AgInSe2) can be used.

[0044] The KSAF phosphor may have a composition represented by the following formula (I). M2[Si p Al q Mn r F s (I)

[0045] In formula (I), M represents an alkali metal and may contain at least K. Mn may be tetravalent Mn ions. p, q, r, and s may satisfy 0.9 ≦ p + q + r ≦ 1.1, 0 < q ≦ 0.1, 0 < r ≦ 0.2, 5.9 ≦ s ≦ 6.1. Preferably, 0.95 ≦ p + q + r ≦ 1.05 or 0.97 ≦ p + q + r ≦ 1.03, 0 < q ≦ 0.03, 0.002 ≦ q ≦ 0.02 or 0.003 ≦ q ≦ 0.015, 0.005 ≦ r ≦ 0.15, 0.01 ≦ r ≦ 0.12 or 0.015 ≦ r ≦ 0.1, 5.92 ≦ s ≦ 6.05 or 5.95 ≦ s ≦ 6.025. For example, K2[Si 0.946 Al 0.005 Mn 0.049 F 5.995 , K2[Si 0.942 Al 0.008 Mn 0.050 F5.992 ], K2[Si 0.939 Al 0.014 Mn 0.047 F 5.986 Such a KSAF phosphor can provide red light emission with high luminance and a narrow half-width of the emission peak wavelength.

[0046] The wavelength converting sections 41 and 42 may contain different phosphors. Furthermore, the wavelength converting sections 41 and 42 may contain a light diffusing material, which will be described later.

[0047] [Translucent parts 51, 52] The light-transmitting portions 51 and 52 are each formed from a resin material whose base material is, for example, a silicone resin or the like. Typically, the light-transmitting portions 51 and 52 have a transmittance of 60% or more for light having the emission peak wavelengths of the first light-emitting element 10 and the second light-emitting element 20. From the viewpoint of effectively utilizing light, the transmittance of the light-transmitting portions 51 and 52 at the emission peak wavelengths of the first light-emitting element 10 and the second light-emitting element 20 is preferably 70% or more, and more preferably 80% or more.

[0048] In addition to silicone resin, for example, silicone modified resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, polymethylpentene resin, polynorbornene resin, or a material containing two or more of these can be used as the base material of the light-transmitting parts 51 and 52. Glass may be selected as the material of the light-transmitting parts 51 and 52.

[0049] The light-diffusing function may be imparted to the light-transmitting portions 51 and 52 by dispersing a light-diffusing material having a refractive index different from that of the base material in the base material. As the light-diffusing material, for example, particles of a resin having a refractive index different from that of the base material, or particles of silicon oxide, aluminum oxide, zirconium oxide, or zinc oxide can be used. As the light-diffusing material dispersed in the base material, D 50 By using nanoparticles having a particle size, defined as being 1 nm or more and 100 nm or less, scattering in the light-transmitting member can be increased.

[0050] The light-transmitting portions 51 and 52 cover the upper surfaces of the wavelength converting portions 41 and 42, respectively, and thus it is possible to prevent the wavelength converting portions 41 and 42 from being exposed to the external environment and the phosphor from being deteriorated. Furthermore, the light from the first light-emitting element 10 and the second light-emitting element 20 that has been wavelength-converted by the wavelength converting portions 41 and 42 and the light that has not been converted by the wavelength converting portions 41 and 42 enter the light-transmitting portions 51 and 52, and these two types of light are mixed and diffused within the light-transmitting portions 51 and 52, so that unevenness in luminance and chromaticity is suppressed and the mixed light can be emitted to the outside.

[0051] [Joint member 30] The bonding member 30 is located between the first light-emitting element 10 and the first light-transmissive member 80 and between the second light-emitting element 20 and the second light-transmissive member 90, and bonds the first light-transmissive member 80 and the second light-transmissive member 90 to the first light-emitting element 10 and the second light-emitting element 20, respectively. The bonding member 30 may cover a part of the side surface of the first light-emitting element 10 and a part of the side surface of the second light-emitting element 20.

[0052] A resin material containing a transparent resin as a base material can be used as the material of the joining member 30. As the base material, for example, the same material as the base material of the light-transmitting parts 51 and 52 can be used. The joining member 30 may have a light diffusion function by dispersing a light diffusion material having a refractive index different from that of the base material.

[0053] [Light-reflective member 60] The light-reflective member 60 covers the side surfaces of the first light-emitting element 10 and the second light-emitting element 20 and the side surfaces of the first light-transmissive member 80 and the second light-transmissive member 90, thereby preventing light from leaking from the side surfaces of these members and increasing the efficiency of light emission from the front of the light-emitting device 101.

[0054] The light reflective member 60 includes a first portion 61 and a second portion 62. Specifically, the first portion 61 covers at least a part of the first side surface 10c of the first light emitting element 10, the first side surface 80c of the first light transmissive member 80, at least a part of the first side surface 20c of the second light emitting element 20, and the first side surface 90c of the second light transmissive member 90. The second portion 62 covers at least a part of the second side surface 10d of the first light emitting element 10, the second side surface 80d of the first light transmissive member 80, at least a part of the second side surface 20d of the second light emitting element 20, and the second side surface 90d of the second light transmissive member 90. When a bonding member 30 is disposed between the first light emitting element 10 and the first light transmissive member 80 and between the second light emitting element 20 and the second light transmissive member 90, the first portion 61 and the second portion 62 also cover the bonding member 30.

[0055] The light reflective member 60 further includes a third portion 63, a fourth portion 64, and a fifth portion 65. The third portion 63 covers at least a part of the third side surface 10e of the first light emitting element 10, the third side surface 80e of the first light transmissive member 80, and the joining member 30. The fourth portion 64 is located between the first light emitting element 10 and the second light emitting element 20 in the X direction in a plan view. The fourth portion 64 covers at least a part of the fourth side surface 10f of the first light emitting element 10, the fourth side surface 80f of the first light transmissive member 80, at least a part of the third side surface 20e of the second light emitting element 20, the third side surface 90e of the second light transmissive member 90, and the joining member 30. The fifth portion 65 covers at least a part of the fourth side surface 10f of the second light emitting element 20, the fourth side surface 80f of the second light transmissive member 90, and the joining member 30. The light reflective member 60 may further include a sixth portion 66 covering the lower surface 10b of the first light emitting element 10 and the lower surface 20b of the second light emitting element 20. The first portion 61 and the second portion 62 are also disposed adjacent to the third portion 63, the fourth portion 64, and the fifth portion 65.

[0056] In the light reflective member 60, the first portion 61 has a convex portion 61T adjacent to the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90 and extending along the X direction. In this embodiment, the convex portion 61T is also disposed adjacent to the third portion 63, the fourth portion 64, and the fifth portion 65. The convex portion 61T has an upper surface 61Ta, which is located higher than the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90. The height of the upper surface 61Ta relative to the upper surface 90a is, for example, 0.01 mm to 0.06 mm. The second portion 62 has an upper surface 62a located lower than the upper surface 61Ta of the convex portion 61T. In this embodiment, the upper surface 62a is flat and is located at the same height as the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90.

[0057] The third portion 63, the fourth portion 64, and the fifth portion 65 also have upper surfaces that are located at the same height as the upper surfaces 80a of the first light-transmissive member 80 and the upper surfaces 90a of the second light-transmissive member 90, respectively. Therefore, except for the convex portion 61T, on the front surface 100a of the light-emitting device 101, the upper surface of the light-reflective member 60, and the upper surfaces 80a of the first light-transmissive member 80 and 90a of the second light-transmissive member 90 form an integrated flat surface.

[0058] The light reflecting member 60 is an integrally molded body consisting of the first portion 61, the second portion 62, the third portion 63, the fourth portion 64, the fifth portion 65, the sixth portion 66, and the convex portion 61T described above, and covers the upper surface 75a of the substrate 70. However, the convex portion 61T does not have to be an integrally molded body, and may be provided as a separate body on the first portion 61. The light reflecting member 60 is formed, for example, from a resin material in which a light diffusing material is dispersed. For example, silicone resin, modified silicone resin, epoxy resin, urea resin, polycarbonate resin, phenol resin, acrylic resin, urethane resin, fluororesin, or modified resins thereof, or resins containing two or more of these, can be used as the base material of the light reflecting member 60. For example, particles of an inorganic material or an organic material having a higher refractive index than the base material can be used as the light diffusing material. Examples of the light diffusing material are particles of titanium oxide, magnesium oxide, zirconium dioxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, niobium oxide, barium sulfate, silicon oxide, various rare earth oxides (e.g., yttrium oxide, gadolinium oxide), etc. The light reflective member 60 exhibits, for example, white color.

[0059] In this specification, "light reflectivity" refers to a reflectance of 60% or more at the emission peak wavelength of the light emitting element (first light emitting element 10 or second light emitting element 20). The reflectance of the light reflective member 60 is preferably 70% or more, and more preferably 80% or more, at the emission peak wavelength of the light emitting element.

[0060] [Effects of Light Emitting Device 101] The effects of the light emitting device 101 configured as above will be described. Fig. 9 is a schematic side view showing a part of a backlight 301 in which the light emitting device 101 is incorporated. The backlight 301 includes a housing 311, a light guide plate 312, a mounting substrate 313, a support 314, and the light emitting device 101. The light emitting device 101 is mounted on the mounting substrate 313 at the bottom surface 100d, and receives a current supply from the mounting substrate 313.

[0061] The housing 311 supports the light emitting device 101 and the light guide plate 312. The light guide plate 312 is supported by the housing 311 via a support 314 to adjust the height position so that the front surface 100a, which is the emission surface of the light emitting device 101, faces the side surface 312c of the light guide plate 312. As shown in FIG. 9, the upper surface 61Ta of the convex portion 61T contacts the side surface 312c of the light guide plate 312. Therefore, a gap G is formed between the side surface 312c of the light guide plate 312 and the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90.

[0062] Light emitted from the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90 located on the front surface 100a of the light-emitting device 101 enters the light guide plate 312 from the side surface 312c. Since the side surface 312c is not in contact with the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90, and an air layer is interposed between them, total reflection is unlikely to occur for light incident on the side surface 312c of the light guide plate 312, and total reflection is likely to occur for light returning from the side surface 312c of the light guide plate 312 to the light-emitting device 101. This makes it possible to make the light emitted from the light-emitting device 101 enter the light guide plate 312 with high optical coupling efficiency. In addition, light spreading from the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90 to the positive side in the Y direction is reflected by the convex portion 61T and proceeds to the negative side in the Y direction. This allows light that is obliquely emitted from the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90 and moves toward the outside of the side surface 312c while traveling through the gap G to be returned to the side surface 312c. This allows light emitted from the light emitting device 101 to be incident on the side surface of the light guide plate with high optical coupling efficiency. Also, by arranging the light emitting device 101 and the light guide plate 312 with the protrusion 61T in contact with the side surface 312c of the light guide plate 312, it becomes easier to set the interval of the gap G to a constant value.

[0063] (Method of manufacturing a light emitting device) Next, a method for manufacturing the light emitting device according to the present embodiment will be described with reference to the drawings. Fig. 10 is a flow chart showing the method for manufacturing the light emitting device according to the present embodiment.

[0064] The method for manufacturing a light emitting device according to the present embodiment includes a step (A) of preparing a composite substrate, and a step (B) of forming a convex portion of a light reflective member and an upper surface of a light transmissive member. The method for manufacturing a light emitting device according to the present embodiment may further include a step (C) of singulating. Each step will be described in detail below.

[0065] [Step (A) of preparing a composite substrate] First, a composite substrate is prepared on which a plurality of light-emitting elements, a plurality of light-transmitting members, and a light-reflecting member are arranged. This process further includes a step (A1) of arranging a plurality of light-emitting elements, a step (A2) of arranging a plurality of light-transmitting members, a step (A3) of arranging the light-reflecting members, and a step (A4) of exposing the light-transmitting members.

[0066] (1) Step (A1) of arranging a plurality of light-emitting elements An aggregate substrate is prepared, and a plurality of light-emitting elements are arranged two-dimensionally on the aggregate substrate with gaps in the first and second directions. In this embodiment, the substrates 70 shown in Fig. 1, Fig. 3, etc. are arranged two-dimensionally in the X and Y directions, and a plurality of light-emitting elements are arranged on the aggregate substrate connected to each other.

[0067] 11 and 12 show a part of an upper surface 75'a and a lower surface 75'b of such an aggregate substrate 70', respectively. The aggregate substrate 70' includes substrates 75' in which the substrates 75 of the substrates 70 are arranged two-dimensionally in the X direction and the Y direction and connected to each other. As shown in FIG. 11, a first wiring 71' is arranged on the upper surface 75'a. A plurality of recesses 75'r are formed on the lower surface 75'b, and a third wiring 73' is arranged in the recesses 75'r. A second wiring 72' is arranged on the lower surface 75'b so as to cover the periphery of the recess 75'r. The second wirings 72' are connected to each other in the Y direction by a connection portion 72'c. A through hole 75h having an opening on the upper surface 75'a and the lower surface 75'b is provided in the substrate 75', and a conductive member 76 connecting the first wiring 71' and the second wiring 72' is arranged in the through hole 75h. The recess 75'r has a circular opening on the lower surface 75'b. An insulating layer 77' is further provided on the lower surface 75'b to cover a portion of the second wiring 72'.

[0068] The aggregate substrate 70' is a base material 75' having recesses 75'r and conductive members 76 formed therein, and can be obtained by forming a conductive film by plating or the like on both sides of a plate-shaped insulating base material, and then patterning the conductive film.

[0069] Next, a first light emitting element 10 and a second light emitting element 20 are prepared as a plurality of light emitting elements. Here, a plurality of pairs of the first light emitting element 10 and the second light emitting element 20 are prepared, and the first light emitting element 10 and the second light emitting element 20 are two-dimensionally arranged with gaps in the X direction and the Y direction as shown in Fig. 13 and Fig. 14. Specifically, the electrodes 11, 21 of the first light emitting element 10 and the second light emitting element 20 are connected to the first wiring 71' using a conductive bonding member such as solder.

[0070] (2) Step (A2) of arranging a plurality of light-transmitting members A plurality of light-transmissive members are disposed on the emission surfaces of a plurality of light-emitting elements. Specifically, as shown in FIG. 15, an uncured bonding member is disposed on the upper surface 10a of the first light-emitting element 10 and the upper surface 20a of the second light-emitting element 20, and a first light-transmissive member 80' and a second light-transmissive member 90' are disposed on the upper surface 10a and the upper surface 20a. By curing the uncured bonding member, the first light-emitting element 10 and the first light-transmissive member 80' are bonded via the bonding member 30, and the second light-emitting element 20 and the second light-transmissive member 90' are bonded.

[0071] (3) Step (A3) of arranging a light-reflective member A light-reflecting member is disposed to cover the side surfaces of the plurality of light-emitting elements and the side surfaces and upper surfaces of the plurality of light-transmitting members. Specifically, as shown in FIG. 16, an uncured light-reflecting member is disposed on the upper surface 75'a of the assembly substrate 70' so as to cover the side surfaces of the first light-emitting element 10, the side surfaces and upper surface 80'a of the first light-transmitting member 80', the side surfaces of the second light-emitting element 20, the side surfaces and upper surface 90'a of the second light-transmitting member 90', and the bonding member 30. Thereafter, the uncured light-reflecting member is cured to obtain a light-reflecting member 60' that covers the side surfaces of the first light-emitting element 10, the side surfaces and upper surface 80'a of the first light-transmitting member 80', the side surfaces of the second light-emitting element 20, the side surfaces and upper surface 90'a of the second light-transmitting member 90', and the bonding member 30. FIG. 17A is a perspective view showing a part of the composite substrate 201' obtained in this manner, and FIG. 17B is a YZ cross-sectional view at a position crossing the first light-emitting element 10 of the composite substrate 201'. Since the cross section across the second light emitting element 20 also has the same structure, components of the second light emitting element 20 are also shown in parentheses in FIG. 17B.

[0072] (4) Step (A4) of exposing the light-transmitting member In the composite substrate 201', the light reflective member 60' is ground from the upper surface 60'a so that the upper surface 80'a of the first light-transmissive member 80' and the upper surface 90'a of the second light-transmissive member 90' are exposed. Specifically, the entire upper surface 60'a of the light reflective member 60' is ground by a grinding device such as a lapping device. As a result, as shown in Figs. 18A and 18B, a composite substrate 201 is obtained in which the upper surface 80'a of the first light-transmissive member 80' and the upper surface 90'a of the second light-transmissive member 90' are exposed on the main surface 201'a of the composite substrate 201'.

[0073] In the composite substrate 201′, the first light-emitting element 10 and the second light-emitting element 20, which are multiple light-emitting elements, are arranged with their longitudinal directions along the X direction, and as described above, are arranged two-dimensionally with gaps in the X direction and Y direction.

[0074] The light-reflective member 60' is disposed between the first light-emitting element 10, the first light-transmissive member 80', the second light-emitting element 20 and the second light-transmissive member 90' so as to cover the side surface of the first light-emitting element 10, the side surface of the first light-transmissive member 80', the side surface of the second light-emitting element 20 and the side surface of the second light-transmissive member 90'.

[0075] As shown in FIG. 18B, the light reflective member 60' includes a pair of first portions 61' located outside two first light emitting elements 10 and two first light transmissive members 80' adjacent to each other in the Y direction, and a second portion 62' located between the two first light emitting elements 10 and the two first light transmissive members 80'. The pair of first portions 61' each have an upper surface (first upper surface) 61'a, and the second portion 62' has an upper surface (second upper surface) 62'a. In addition, the first light transmissive member 80' has an upper surface (third upper surface) 80'a. Similarly, the light reflective member 60' includes a pair of first portions 61' located outside two second light emitting elements 20 and two second light transmissive members 90' adjacent to each other in the Y direction, and a second portion 62' located between the two second light emitting elements 20 and two second light transmissive members 90'. The pair of first portions 61' each have an upper surface (first upper surface) 61'a, and the second portion 62' has an upper surface (second upper surface) 62'a. The second light-transmissive member has an upper surface (third upper surface) 90'a. That is, by grinding the light-reflective member 60', the upper surface (first upper surface) 61'a of the first portion 61, the upper surface (second upper surface) 62'a of the second portion 62, the upper surface (third upper surface) 80'a of the first light-transmissive member 80', and the upper surface (third upper surface) 90'a of the second light-transmissive member 90' are exposed. The upper surface (first upper surface) 61'a, the upper surface (second upper surface) 62'a, and the upper surfaces (third upper surfaces) 80'a, 90'a are all flat and are located at the same height. Moreover, the top surface (first top surface) 61'a, the top surface (second top surface) 62'a and the top surfaces (third top surfaces) 80'a and 90'a form one continuous flat surface.

[0076] [Step (B) of forming the convex portion of the light-reflective member and the upper surface of the light-transmitting member] Next, at least a portion of the pair of first portions 61' and the second portion 62' of the light-reflective member 60', the first light-transmissive member 80' on the two first light-emitting elements 10, and the second light-transmissive member 90' on the two second light-emitting elements 20 are ground from the exposed top surface (first top surface) 61'a, top surface (second top surface) 62'a, and top surfaces (third top surfaces) 80'a, 90'a.

[0077] 19A and 19B, a rotary grinding blade (rotary wheel) 250 is moved along the X direction relative to the composite substrate 201' to grind the first portion 61', the second portion 62', the first light-transmissive member 80', and the second light-transmissive member 90' from the top surface (first top surface) 61'a, the top surface (second top surface) 62'a, and the top surfaces (third top surfaces) 80'a, 90'a shown in FIGS. 18A and 18B. This results in a composite substrate 201'' shown in FIGS. 20A and 20B.

[0078] As shown in Figures 20A and 20B, this process forms a convex portion 61'T extending in the X direction in a first portion 61' of a light reflective member 60'. The first portion 61' has an upper surface (first upper surface) 61'Ta. The second portion 62' has a new upper surface (fourth upper surface) 62a. Furthermore, a first light-transmissive member 80 and a second light-transmissive member 90 are formed, each having a new upper surface (fifth upper surface) 80a and 90a.

[0079] The upper surface (fourth upper surface) 62a is located lower than the upper surface (first upper surface) 61'Ta, and the upper surfaces (fifth upper surface) 80a and 90a are at the same height as the upper surface (fourth upper surface) 62 or at a lower position than the upper surface (fourth upper surface) 62a. In this embodiment, the upper surfaces (fifth upper surface) 80a and 90a are at the same height as the upper surface (fourth upper surface) 62a and are flat surfaces. In other words, the upper surfaces (fifth upper surface) 80a and 90a and the upper surface (fourth upper surface) 62a form a continuous flat surface.

[0080] The thickness T (width) of the rotary grinding blade 250 (Fig. 19B) may be the same as the interval W between the pair of convex portions 61’T, or may be narrower. If T = W, the above-described structure can be formed by simply moving the rotary grinding blade 250 once in the X direction. On the other hand, when T < W, change the position of the rotary grinding blade 250 in the Y direction and move it in the X direction two or more times. In the Y direction, grinding may be performed across the two first light-emitting elements 10 or the second light-emitting elements 20. That is, the thickness T of the rotary grinding blade 250 may be larger than the center interval between two adjacent first light-emitting elements 10 in the Y direction. For this reason, the number of movements of the rotary grinding blade 250 can be reduced.

[0081] In the present embodiment, the grinding surface 250s of the rotary grinding blade 250 has a linear shape in a cross section including from one end to the other end of the rotation axis of the rotary grinding blade 250. For this reason, the surface formed by grinding becomes a flat surface.

[0082] Note that the upper surface of the light-transmissive member and the upper surface of the light-reflective member do not necessarily have to be in one plane. That is, after the step (A3) of arranging the light-reflective member, the light-reflective member may be ground to a height such that a portion that becomes the convex portion 61T remains, and then the light-reflective member and the light-transmissive member may be ground except for the portion that becomes the convex portion 61T. Further, after the step (A3) of arranging the light-reflective member, without grinding the portion that becomes the convex portion 61T, the light-reflective member and the light-transmissive member may be ground until the upper surface of the light-transmissive member is exposed, and then the portion that becomes the convex portion 61T that has not been ground may be ground. In any method, a light-emitting device can be obtained that includes an upper surface that is higher than the upper surface of the light-transmissive member and has a convex portion extending along the first direction in the first portion of the light-reflective member.

[0083] Furthermore, as another manufacturing method, in the step (A3) of arranging the light reflective member, the light reflective member may be arranged so as to cover the side surfaces of the plurality of light emitting elements and the side surfaces of the plurality of light transmissive members. In other words, in the step (A3) of arranging the light reflective member, the light reflective member may be arranged so as not to cover the upper surfaces of the plurality of light transmissive members. Next, the light reflective member may be provided on the portion that will become the convex portion 61T. Finally, the convex portion 61T may be ground to form the convex portion upper surface 61Ta.

[0084] [Individualization process (C)] Thereafter, as indicated by dashed lines CX1, CX2, and CY in FIGS. 20A and 20B, the obtained composite substrate 201'' is cut in the X direction and the Y direction using a rotary blade or the like so as to include the first light-transmissive member 80 and the second light-transmissive member 90, thereby producing the light-emitting device 101 shown in FIGS. 1 to 8. The cutting of the composite substrate 201'' in the X direction includes a cut CX1 at the first portion 61' and a cut CX2 at the second portion 62'. By cutting the second portion 62, the circular recess 75'r shown in FIG. 12 is divided, and a semicircular recess 75r is formed in the back surface 100b as shown in FIG. 4.

[0085] [Effects of manufacturing method of light-emitting device] According to the manufacturing method of the light emitting device of this embodiment, since the light transmissive member is ground across two light emitting elements in the Y direction, a wide grinding blade can be used, and the light emitting device can be manufactured efficiently. In addition, the grinding blade may be moved in the X direction two or more times by changing the position of the grinding blade in the Y direction. Since the Y direction corresponds to the height direction of the light emitting device to be manufactured, it is possible to manufacture light emitting devices 101 of different heights using the same manufacturing equipment.

[0086] Second embodiment FIG. 21 is a perspective view of the light emitting device 102 of this embodiment seen from above, and FIG. 22 is a YZ cross-sectional view of the light emitting device 102. The light emitting device 102 is different from the light emitting device 101 of the first embodiment in that the upper surface of the light transmissive member is a curved surface. As shown in FIG. 21, in the light emitting device 102, the first light transmissive member 80 and the second light transmissive member 90 have curved upper surfaces 80a and 90a having a curvature in the Y direction. The upper surfaces 80a and 90a have a curved shape having a concave curve toward the first light emitting element 10 and the second light emitting element 20 side in the YZ cross section perpendicular to the X direction. As shown in FIG. 22, the upper surface 62a of the second portion 62 of the light reflective member 60 includes a curved surface that is continuous with the curved surface of the upper surface 80a of the first light transmissive member 80 and the curved surface of the upper surface 90a of the second light transmissive member 90.

[0087] The light emitting device 102 having such a structure can be manufactured, for example, by making the shape of the rotary grinding blade 250 different from that of the rotary grinding blade 250 of the first embodiment. As shown in FIG. 23, the grinding surface 250s of the grinding blade 250 used in this embodiment has a curved shape that is convex toward the workpiece side in a cross section passing through the axis of the rotary grinding blade 250. In particular, it has a curved shape at both ends in the Y direction. By using the rotary grinding blade 250 having such a shape, it is possible to form the first light-transmitting member 80 and the second light-transmitting member 90 having the upper surface 80a and the upper surface 90a of the above-mentioned shape.

[0088] FIG. 24 is a perspective view of another light-emitting device 103 of this embodiment seen from above, and FIG. 25 is a YZ cross-sectional view of the light-emitting device 103. The light-emitting device 103 is also different from the light-emitting device 101 of the first embodiment in that the upper surface of the light-transmissive member is curved. As shown in FIG. 25, in the light-emitting device 103, the upper surface 80a of the first light-transmissive member 80 has a first side 80aL1 adjacent to the first portion 61 and a second side 80aL2 adjacent to the second portion 62 and located lower than the first side 80aL1. In addition, the upper surface 80a has a curved shape having a convex curve toward the first light-emitting element 10 side in the YZ cross-section perpendicular to the X direction. Similarly, the upper surface 90a of the second light-transmissive member 90 has a first side 90aL1 adjacent to the first portion 61 and a second side 90aL2 adjacent to the second portion 62 and located lower than the first side 90aL1. Moreover, the upper surface 90a has a curved shape having a convex curve toward the second light-emitting element 20 side in a YZ cross section perpendicular to the X direction.

[0089] Furthermore, the upper surface 62a of the second portion 62 of the light reflective member 60 includes a curved surface or a flat surface that is continuous with the curved surfaces of the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90.

[0090] The light emitting device 103 can also be manufactured by changing the shape of the rotary grinding blade 250 from that of the rotary grinding blade 250 of the first embodiment. As shown in FIG. 26, the grinding surface 250s of the grinding blade 250 used in this embodiment has a curved shape that is convex toward the workpiece in a cross section passing through the axis of the rotary grinding blade 250. In particular, it has a curved shape at both ends in the Y direction. Also, as shown in the figure, the width T of the rotary grinding blade 250 is larger than the distance W2 between the centers of the first light emitting element 10 and the second light emitting element 20 in the Y direction. By using the rotary grinding blade 250 having such a shape, the first light-transmitting member 80 and the second light-transmitting member 90 having the upper surface 80a and the upper surface 90a of the above-mentioned shape can be formed.

[0091] In the light emitting device 102 and the light emitting device 103, the upper surface 80a of the first light-transmissive member 80 and the upper surface 90a of the second light-transmissive member 90 are curved surfaces, and the spread of emitted light in the Y direction can be adjusted according to the curved surfaces. For example, in the light emitting device 102, it is possible to reduce the spread of light in the Y direction and cause the light to enter the light guide plate.

[0092] (Other forms) Various modifications are possible for the light emitting device and the manufacturing method of the light emitting device of this embodiment. For example, in the first embodiment, the light emitting device 101 has a convex portion 61T on the first portion 61 of the light reflective member 60. In contrast, the light emitting device 104 shown in Figs. 27 and 28 has a convex portion 62T extending along the X direction on the second portion 62 of the light reflective member 60, that is, on the bottom surface 100d side. The light emitting device 104 having such a structure can be manufactured by using a method similar to the manufacturing method of the light emitting device of the first embodiment, and setting the grinding position with the rotary grinding blade 250 so that the convex portion 62T is formed.

[0093] Also, for example, in the second embodiment, the upper surface of the light-transmitting member is a curved surface. In contrast, the grinding blade used in the first embodiment, that is, the grinding surface 250s of the rotary grinding blade 250 has a linear shape in a cross section including one end to the other end of the rotation axis of the rotary grinding blade 250, and the grinding blade is tilted from the Z-axis direction to perform grinding. This makes it possible to obtain a light-emitting device in which the upper surface of the light-transmitting member is flat and the upper surface 80a of the first light-transmitting member 80 has a first side 80aL1 adjacent to the first portion 61 and a second side 80aL2 adjacent to the second portion 62 and located lower than the first side 80aL1. As long as at least the convex portion 61T of the light-reflective member has an upper surface 61Ta, the surface formed by grinding may be a curved surface or a flat surface. In this example, the upper surface of the light-transmitting member has an inclined surface inclined from the XY plane. The inclination angle of the inclined surface from the XY plane may be an angle that exceeds the range of error that may occur in grinding aimed at a desired angle, for example, 1° or more. The upper surface of the light-emitting device may have an inclined surface that is inclined over the entire surface, specifically, an inclined surface that is inclined over the entire surface from the end on the first portion side to the end on the second portion side. In this case, the convex portion is the entire part that is higher in the Z direction from the first side 80aL1 of the translucent member adjacent to the first portion 61 of the convex portion. The upper surface of the convex portion is also flush with the upper surface of the translucent member. By the light-emitting device having such an inclined surface, the traveling direction of the light extracted from the light-emitting device can be adjusted.

[0094] In the above embodiment, the light emitting device includes two light emitting elements, but the light emitting device may include one or three or more light emitting elements. In addition, in the above embodiment, independent light transmissive members are arranged on the light emitting elements, but one light transmissive member provided continuously on two or three or more light emitting elements may be arranged. In addition, the convex portion of the first portion only needs to be located adjacent to at least the light transmissive member, and does not need to be located adjacent to the third portion, the fourth portion, and the fifth portion. [Industrial Applicability]

[0095] The embodiments of the present disclosure are useful for various lighting light sources, in-vehicle light sources, display light sources, etc. In particular, they can be advantageously applied to backlight units for liquid crystal display devices. The light emitting device according to the embodiments of the present disclosure can be advantageously used as a backlight for a display device of a mobile device, which has strict requirements for reducing thickness. [Explanation of symbols]

[0096] 10 First light emitting element 10a, 20a, 61a, 61'a, 61Ta, 62a, 62'a, top 10b, 20b bottom side 10c, 20c, 80c, 90c 1st side 10d, 20d, 80d, 90d 2nd side 10e, 20e, 80e, 90e 3rd side 10f, 20f, 80f, 90f 4th side 11, 21 electrode 20 Second light-emitting element 30 Joining materials 41, 42 Wavelength conversion unit 51, 52 Translucent part 60, 60' Light-reflecting member 61,61' Part 1 61'a 1st top surface 61T, 61'T convex part 62, 62' 2nd part 62T convex part 63 Part 3 64 Part 4 65 Part 5 66 Part 6 70 Substrate 70' Assembly Board 70'a top surface 71,71' 1st wiring 72, 72' 2nd wiring 73,73' 3rd wiring 75,75' Base material 75r hollow 75'r hollow 75a Top side 75b Bottom side 75d side 75h through hole 76 Conductive Materials 77, 77' Insulation layer 80, 80' 1st translucent member 80aL1 Side 1 80aL2 Side 2 90, 90' Second translucent member 90aL1 Side 1 90aL2 Side 2 90b Bottom side 90f 4th side 100a Front 100b back 100c Top 100d bottom 100e Side 100f Side 101~104 Light emitting device 201, 201', 201'' composite board 201'a Main surface 250 Rotating Grinding Blade 250s Grinding surface 301 Backlight 311 Case 312 Light guide plate 312c side 313 Mounting Board 314 Support

Claims

1. A composite substrate including: a plurality of light-emitting elements each having an emission surface having a longitudinal direction, the longitudinal direction of which is aligned along a first direction, the plurality of light-emitting elements being arranged two-dimensionally with a gap in the first direction and a second direction perpendicular to the first direction; a plurality of light-transmitting members arranged on the emission surfaces of the plurality of light-emitting elements; and a light-reflecting member arranged between the plurality of light-emitting elements and the plurality of light-transmitting members so as to cover at least the side surfaces of the plurality of light-emitting elements and the side surfaces of the plurality of light-transmitting members, the light-reflecting member including a pair of first portions positioned outside the two light-emitting elements and the two light-transmitting members adjacent to each other in the second direction in the second direction, and a second portion positioned between the two light-emitting elements and the two light-transmitting members, the pair of first portions each having a first upper surface, the second portion having a second upper surface, and the light-transmitting member having a third upper surface; and a step (A) of preparing a composite substrate in which the first upper surface, the second upper surface, and the third upper surface are exposed on a main surface of the composite substrate; a step (B) of grinding at least a part of the pair of first portions and the second portion of the light reflective member and the light-transmitting members of the two light-emitting elements from the exposed first upper surface, the second upper surface, and the third upper surface, forming a convex portion having the first upper surface and extending along the first direction in the first portion, forming a fourth upper surface in the second portion that is located lower than the first upper surface, and forming a fifth upper surface in the light-transmitting members of the two light-emitting elements that is located lower than the first upper surface and is at the same height as the fourth upper surface or lower than the fourth upper surface; A method for manufacturing a light emitting device, comprising:

2. The method for manufacturing a light emitting device according to claim 1 , wherein the first upper surface, the second upper surface, and the third upper surface are located at the same height as each other.

3. The step (A) A step (A1) of two-dimensionally arranging a plurality of light-emitting elements with gaps in the first direction and the second direction; A step (A2) of arranging the plurality of light-transmitting members on the emission surfaces of the plurality of light-emitting elements; A step (A3) of disposing a light reflective member that covers side surfaces of the plurality of light emitting elements and side surfaces and upper surfaces of the plurality of light transmissive members; a step (A4) of grinding the light reflective member from the upper surface to expose the first upper surfaces of the pair of first portions of the light reflective member, the second upper surfaces of the second portions, and the third upper surface of the light transmissive member; The method for manufacturing the light emitting device according to claim 2 , comprising:

4. In the step (B), the fourth upper surface is a plane; The method for manufacturing a light emitting device according to claim 1 , wherein the fifth upper surface is a flat surface located at the same height as the fourth upper surface.

5. In the step (B), The method for manufacturing a light-emitting device according to claim 1 , wherein each of the two fifth upper surfaces includes a curved surface having a convex curve toward the two light-emitting elements in a cross section perpendicular to the first direction.

6. The method for manufacturing a light emitting device according to claim 5 , wherein at least a part of the fourth upper surface includes a curved surface that is continuous with a curved surface of the fifth upper surface.

7. In the step (B), each of the two fifth upper surfaces is adjacent to the first portion. a curved surface having a first side and a second side adjacent to the second portion and located lower than the first side, the curved surface having a concave curve toward the two light-emitting elements in a cross section perpendicular to the first direction, The method for manufacturing a light emitting device according to claim 1 , wherein the fourth upper surface includes a curved surface that is continuous with a curved surface of the fifth upper surface.

8. the composite substrate further includes a substrate having an upper surface and a lower surface located opposite to the upper surface, the substrate including the plurality of light-emitting elements and the light-reflective member disposed on the upper surface; The method for manufacturing a light emitting device according to claim 1 , wherein the substrate has an opening on the lower surface below the second portion and a plurality of recesses arranged along the second direction.

9. 9. The method for manufacturing a light emitting device according to claim 1, wherein in the step (B), grinding from the exposed first upper surface, the second upper surface, and the third upper surface is performed by moving a grinding blade along the first direction.

10. The method for manufacturing a light emitting device according to claim 9 , wherein in the step (B), the grinding blade has a width larger than a center-to-center distance between the two light emitting elements in the second direction.

11. After the step (B), cutting the light reflective member along the first direction at the pair of first portions and the pair of second portions; The method for manufacturing a light emitting device according to claim 9 or 10, further comprising a step (C) of cutting the light reflective member located at least between the plurality of light emitting elements along the second direction so as to include one or more light emitting elements in the first direction.

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