Light emitting device and method for manufacturing same

Abstract

A light-emitting device (100) is provided with: a substrate (110); a light-emitting element (120) that is provided on the substrate (110) and that emits first light (L1); a wavelength converting layer (130) that is provided on the light-emitting element (120) and that contains a plurality of wavelength converting particles (131) for emitting second light (L2) by wavelength-converting a portion of the first light (L1); a light-transmitting plate (140) provided above the wavelength converting layer (130); and a wall (150) that surrounds the wavelength converting layer (130) and the light-transmitting plate (140), that has an inner surface 150b in contact with a lateral surface (140c) of the light-transmitting plate, and that contains a light reflecting material. An upper section of the wavelength converting layer (130) has irregularities due to the wavelength converting particles (131). An air layer (130k) is provided between the wavelength converting layer (130) and the light-transmitting plate (140).

Description

[Technical Field]

[0001] The embodiments relate to a light emitting device and a method for manufacturing the same. [Background technology]

[0002] A light-emitting device has been known that includes a substrate, a light-emitting element provided on the substrate, a wavelength conversion layer provided on the light-emitting element, and a wall that includes a light-reflective material and surrounds the wavelength conversion layer. In such a light-emitting device, there is a need to suppress light propagation through the wall and leakage of the light propagated through the wall from an upper surface of the wall. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-195758 Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments aim to provide a light emitting device that can suppress light leakage from the upper surface of a wall, and a method for manufacturing the same. [Means for solving the problem]

[0005] The light emitting device according to the embodiment includes a substrate, a light emitting element provided on the substrate and emitting a first light, a wavelength conversion layer provided on the light emitting element and containing a plurality of wavelength converting particles that convert the wavelength of a portion of the first light and emit a second light, a light-transmitting plate provided above the wavelength conversion layer, and a wall that surrounds the wavelength conversion layer and the light-transmitting plate, the inner surface of which is in contact with a side surface of the light-transmitting plate and contains a light-reflective material, wherein the upper part of the wavelength conversion layer has unevenness caused by the wavelength converting particles, and an air layer is provided between the wavelength conversion layer and the light-transmitting plate.

[0006] A method for manufacturing a light-emitting device according to an embodiment includes the steps of: placing a light-emitting element that emits first light on a substrate; arranging a wavelength conversion layer on the light-emitting element, the wavelength conversion layer having a plurality of wavelength conversion particles that convert the wavelength of a portion of the first light and emit second light, such that the upper portion has unevenness caused by the wavelength conversion particles; arranging a light-transmitting plate above the wavelength conversion layer such that an air gap is formed between the wavelength conversion layer and the light-transmitting plate; providing uncured light-reflecting material so as to surround the wavelength conversion layer and the light-transmitting plate; and forming a wall by curing the light-reflecting material. [Effects of the Invention]

[0007] According to the embodiment, it is possible to provide a light emitting device that can suppress light leakage from the upper surface of a wall, and a method for manufacturing the same. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a top view showing a light emitting device according to a first embodiment. [Figure 2A] FIG. 2 is a diagram showing an example of an end face taken along line II-II in FIG. [Figure 2B] 2 is a diagram showing another example of the end face taken along line II-II in FIG. 1. FIG. [Figure 3] 2B is an enlarged end view showing a part of the light emitting element, a part of the wavelength conversion layer, and a part of the light-transmitting plate in FIG. 2A. FIG. [Figure 4A] 2 is an end view illustrating an example of a light path on an end surface taken along line II-II in FIG. 1. FIG. [Figure 4B] 2B is an enlarged end view illustrating the path of light in a part of the light emitting element, part of the wavelength conversion layer, and part of the light-transmitting plate in FIG. 2A. FIG. [Figure 5A] 3A to 3C are diagrams illustrating a method for manufacturing the light emitting device according to the first embodiment. [Figure 5B] 3A to 3C are diagrams illustrating a method for manufacturing the light emitting device according to the first embodiment. [Figure 5C] 3A to 3C are diagrams illustrating a method for manufacturing the light emitting device according to the first embodiment. [Figure 5D] 3A to 3C are diagrams illustrating a method for manufacturing the light emitting device according to the first embodiment. [Figure 5E] 3A to 3C are diagrams illustrating a method for manufacturing the light emitting device according to the first embodiment. [Figure 6A] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a reference example. [Figure 6B] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a reference example. [Figure 7] FIG. 4 is an end view showing a light emitting device according to a second embodiment. [Figure 8] 5A to 5C are diagrams illustrating a method for manufacturing a light emitting device according to a second embodiment. [Figure 9] FIG. 10 is an end view showing a light emitting device according to a third embodiment. [Figure 10] FIG. 10 is an end view showing a light emitting device according to a fourth embodiment. [Figure 11A] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a fourth embodiment. [Figure 11B] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a fourth embodiment. [Figure 12] FIG. 10 is an end view showing a light emitting device according to a fifth embodiment. [Figure 13A] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a fifth embodiment. [Figure 13B] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a fifth embodiment. [Figure 13C] 10A to 10C are diagrams illustrating a method for manufacturing a light emitting device according to a fifth embodiment. [Figure 14] FIG. 10 is an end view showing a light emitting device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The light emitting device according to the embodiment includes a substrate, a light emitting element provided on the substrate and emitting a first light, a wavelength conversion layer provided on the light emitting element and containing a plurality of wavelength converting particles that convert the wavelength of a portion of the first light and emit a second light, a light-transmitting plate provided above the wavelength conversion layer, and a wall that surrounds the wavelength conversion layer and the light-transmitting plate, the inner surface of which is in contact with a side surface of the light-transmitting plate and contains a light-reflective material, wherein the upper part of the wavelength conversion layer has unevenness caused by the wavelength converting particles, and an air layer is provided between the wavelength conversion layer and the light-transmitting plate.

[0010] A method for manufacturing a light-emitting device according to an embodiment includes the steps of: placing a light-emitting element that emits first light on a substrate; arranging a wavelength conversion layer on the light-emitting element, the wavelength conversion layer having a plurality of wavelength conversion particles that convert the wavelength of a portion of the first light and emit second light, such that the upper portion has unevenness caused by the wavelength conversion particles; arranging a light-transmitting plate above the wavelength conversion layer such that an air gap is formed between the wavelength conversion layer and the light-transmitting plate; providing uncured light-reflecting material so as to surround the wavelength conversion layer and the light-transmitting plate; and forming a wall by curing the light-reflecting material.

[0011] The specific configuration of the light emitting device according to each embodiment will be described below. For ease of explanation, an XYZ Cartesian coordinate system will be used in this specification. As shown in FIGS. 1 and 2A, the direction from the substrate 110 toward the light emitting element 120 is referred to as the "Z direction." The Z direction is also referred to as the "upward direction." The opposite direction to the Z direction is also referred to as the "downward direction." A direction perpendicular to the Z direction is referred to as the "X direction." A direction perpendicular to the Z direction and the X direction is referred to as the "Y direction." Directions perpendicular to the Z direction, such as the X direction and the Y direction, are also referred to as the "lateral direction."

[0012] First Embodiment First, a light emitting device 100 according to the first embodiment will be described. FIG. 1 is a top view showing a light emitting device according to this embodiment. FIG. 2A is a diagram showing an example of an end face taken along line II-II in FIG. FIG. 2B is a diagram showing another example of the end face taken along line II-II in FIG. As shown in FIGS. 1 and 2A, the light emitting device 100 includes a substrate 110, a light emitting element 120, a wavelength conversion layer 130, a light-transmitting plate 140, and a wall 150.

[0013] As shown in FIG. 2A , the light-emitting element 120 is provided on the substrate 110 and emits a first light L1. The wavelength conversion layer 130 is provided on the light-emitting element 120. The wavelength conversion layer 130 includes a plurality of wavelength conversion particles 131 that convert the wavelength of a portion of the first light L1 and emit a second light L2. The light-transmitting plate 140 is provided above the wavelength conversion layer 130. The wall 150 surrounds the wavelength conversion layer 130 and the light-transmitting plate 140. An inner surface 150b of the wall 150 is in contact with a side surface 140c of the light-transmitting plate 140. The wall 150 includes a light-reflective material.

[0014] The upper part of the wavelength conversion layer 130 has unevenness due to the wavelength conversion particles 131. An air layer 130k is provided between the wavelength conversion layer 130 and the light-transmitting plate 140. Each part of the light emitting device 100 will be described in detail below.

[0015] The substrate 110 is, for example, a wiring board in which wiring connected to the light emitting element 120 is provided in a base material made of a resin material. However, the base material of the substrate 110 is not limited to this, and ceramics or the like may also be used.

[0016] As shown in Fig. 2A, the surface of the substrate 110 includes an upper surface 110a and a lower surface 110b. The upper surface 110a and the lower surface 110b are flat surfaces and are approximately parallel to the X direction and the Y direction. As shown in Fig. 1, the shape of the substrate 110 when viewed from above is quadrangular. However, the shape of the substrate 110 when viewed from above is not limited to this.

[0017] Three light-emitting elements 120 are mounted on the upper surface 110a of the substrate 110. The three light-emitting elements 120 are arranged along the X direction. However, the number of light-emitting elements 120 provided on the substrate 110 is not particularly limited as long as it is one or more. Furthermore, when a plurality of light-emitting elements 120 are provided in the light-emitting device 100, the plurality of light-emitting elements 120 may be arranged not only in the X direction but also in the Y direction. The shape of each light-emitting element 120 when viewed from above is quadrangular. However, the shape of the light-emitting element 120 is not limited to this.

[0018] 2A, in this embodiment, the light emitting elements 120 are LEDs (Light Emitting Diodes) in which the front surface side of a semiconductor layer stacked on a growth substrate of the light emitting elements 120 is mounted on the substrate 110 (FD (Face Down) mounting). A conductive bonding member 160 is provided between each light emitting element 120 and the substrate 110. Each light emitting element 120 is bonded to the substrate 110 by the bonding member 160.

[0019] The light emitting element 120 emits blue light as the first light L1, but the color of the first light L1 is not limited to blue.

[0020] A light-shielding layer 170 is provided between each light-emitting element 120 and the substrate 110. The light-shielding layer 170 includes a base material made of a resin material and a plurality of fillers dispersed in the base material. The resin material may be a thermosetting resin such as a silicone resin or an epoxy resin. The filler may be a light-reflective material such as titanium oxide (TiO2). However, the light-shielding layer 170 does not necessarily have to be provided between each light-emitting element 120 and the substrate 110.

[0021] FIG. 3 is an enlarged end view of a part of the light emitting element, a part of the wavelength conversion layer, and a part of the light-transmitting plate in FIG. 2A. A wavelength conversion layer 130 is provided on the upper surface of each light emitting element 120. The wavelength conversion layer 130 has a plurality of wavelength conversion particles 131. The upper portion of the wavelength conversion layer 130 has projections and depressions due to the plurality of wavelength conversion particles 131.

[0022] The wavelength converting particles 131 may be made of a yellow phosphor that absorbs the blue first light L1 and emits the yellow second light L2. The wavelength converting layer 130 emits the second light L2 and transmits a portion of the first light L1. Therefore, the light emitting device 100 emits white light that is a mixture of the first light L1 and the second light L2.

[0023] However, the wavelength conversion particles 131 do not have to be yellow phosphors. The wavelength conversion particles 131 may be a red phosphor that converts the wavelength of the first light L1 to emit red light, or a green phosphor that converts the wavelength of the first light L1 to emit green light. In this case, the light emitting device 100 can emit white light by mixing the red light emitted by the red phosphor, the green light emitted by the green phosphor, and the blue light of the first light L1. The light emitting device 100 may also emit a single color other than white.

[0024] The wavelength converting particles 131 are covered with a glass layer 132. The glass layer 132 is made of silica (SiO2). The glass layer 132 bonds the wavelength converting particles 131 to each other and to the light emitting element 120 and the wavelength converting particles 131, thereby holding the wavelength converting particles 131 within the wavelength converting layer 130. The glass layer 132 also protects the wavelength converting particles 131 from moisture in the air and the like. Air layers 130k (gaps) are formed between the wavelength converting particles 131 and the light-transmitting plate 140, between the wavelength converting particles 131, and between the light emitting element 120 and the wavelength converting particles 131.

[0025] Below are examples of the dimensions of each part. The wavelength converting layer 130 has a thickness of, for example, 20 to 200 μm. The wavelength converting particles 131 have a diameter of, for example, 2 to 23 μm, e.g., 5 to 15 μm. The glass layer 132 has a thickness of, for example, 1 to 5 μm.

[0026] The configuration of the wavelength conversion layer 130 is not limited to the above, as long as at least the upper portion has unevenness due to the wavelength conversion particles 131. For example, the wavelength conversion particles 131 do not need to be covered with the glass layer 132. In this case, the wavelength conversion particles 131 may be held within the wavelength conversion layer 130 by binding each other and the light emitting element 120 and the wavelength conversion particles 131 with a binder made of a resin material such as silicone resin. Alternatively, the wavelength conversion particles 131 may be held within the wavelength conversion layer 130 by bonding each other and the light emitting element 120 and the wavelength conversion particles 131 with electrostatic adhesion without using a binder.

[0027] As shown in FIG. 2A , a light-transmitting plate 140 is provided above the wavelength conversion layer 130. The light-transmitting plate 140 protects the wavelength conversion layer 130 from dust, moisture in the air, and the like. The light-transmitting plate 140 is translucent to the second light L2 emitted from the wavelength conversion layer 130. "Light-transmitting" means that 40% or more, preferably 60% or more, and more preferably 80% or more of the second light L2 is transmitted through the light-transmitting plate 140. The light-transmitting plate 140 can be made of a light-transmitting material such as glass, sapphire, or a silicone molded body.

[0028] The light-transmitting plate 140 has a rectangular parallelepiped shape. The surface of the light-transmitting plate 140 includes an upper surface 140a, a lower surface 140b, and a side surface 140c. The upper surface 140a is flat. The upper surface 140a is parallel to the upper surface 110a of the substrate 110. "Parallel" does not mean strictly parallel, but includes variations in the manufacturing process, and it is sufficient if the surfaces are substantially parallel.

[0029] The lower surface 140b is located opposite the upper surface 140a and faces the wavelength conversion layer 130. The lower surface 140b is flat and parallel to the upper surface 110a of the substrate 110. The side surface 140c is located between the upper surface 140a and the lower surface 140b and is in contact with the upper surface 140a and the lower surface 140b. In this embodiment, the lower surface 140b is separated from the wavelength conversion layer 130. However, as shown in FIG. 2B , a portion of the lower surface 140b may be in contact with the wavelength conversion layer 130.

[0030] The side surface 140c is perpendicular to the top surface 140a. The term "perpendicular" does not mean strictly perpendicular, but includes variations in the manufacturing process, and it is sufficient if the side surface 140c is substantially perpendicular.

[0031] 1 and 2A, in this embodiment, the light emitting element 120, the wavelength conversion layer 130, and the light-transmitting plate 140 are surrounded by a wall 150. The wall 150 has a cylindrical shape.

[0032] The wall 150 includes a base material made of a resin material and a plurality of fillers made of a light-reflecting material. The resin material of the wall 150 may be a thermosetting resin such as a silicone resin or an epoxy resin. The light-reflecting material of the wall 150 may be silicon oxide (SiO2), titanium oxide (TiO2), aluminum (Al), silver (Ag), or the like.

[0033] The surfaces of the wall 150 include an upper surface 150a, an inner surface 150b, an outer surface 150c, and a lower surface 150d.

[0034] The upper surface 150a is flat and parallel to the upper surface 110a of the substrate 110. The upper surface 150a is in contact with the inner surface 150b and the outer surface 150c. The upper surface 150a is flush with the upper surface 140a of the light-transmitting plate 140.

[0035] In this embodiment, the inner surface 150b surrounds the light-emitting element 120, the wavelength conversion layer 130, and the light-transmitting plate 140. The inner surface 150b is in contact with the side surfaces of the light-emitting element 120, the lateral ends of the wavelength conversion layer 130, and the side surface 140c of the light-transmitting plate 140. A region of the inner surface 150b that includes at least the uppermost end 150t is in contact with the side surface 140c of the light-transmitting plate 140 and is therefore perpendicular to the upper surface 110a of the substrate 110.

[0036] The outer surface 150c is provided around the periphery of the upper surface 150a. The outer surface 150c is perpendicular to the upper surface 110a of the substrate 110. However, the shape of the outer surface 150c is not particularly limited. For example, the outer surface 150c may be inclined with respect to the Z axis.

[0037] The lower surface 150d is located on the opposite side of the upper surface 150a and is in contact with the upper surface 110a of the substrate 110 in this embodiment.

[0038] The wall 150 surrounds the light-transmitting plate 140 provided above the wavelength conversion layer 130. Therefore, the upper surface 150a is located higher than the upper surface 130a of the wavelength conversion layer 130. The distance between the upper surface 130a of the wavelength conversion layer 130 and the upper surface 150a of the wall 150 is preferably 50 μm or more and 2000 μm or less. The "distance between the upper surface 130a of the wavelength conversion layer 130 and the upper surface 150a of the wall 150" refers to the shortest distance in the Z direction between the upper surface 130a of the wavelength conversion layer 130 and the upper surface 150a of the wall 150.

[0039] In this embodiment, the upper surface 150a is parallel to the upper surface 110a of the substrate 110, and the region of the inner surface 150b including the upper end 150t is perpendicular to the upper surface 110a of the substrate 110. Therefore, the angle θ of the corner c between the upper surface 150a and the inner surface 150b is 90 degrees. However, the angle θ of the corner c is not limited to this.

[0040] Next, the operation of the light emitting device 100 according to this embodiment will be described. FIG. 4A is a diagram illustrating an example of a light path on an end face taken along line II-II in FIG. The wall 150 is provided around the light emitting element 120 and the wavelength conversion layer 130. Therefore, when the light emitting element 120 is turned on, a part of the first light L1 emitted from the light emitting element 120 and a part of the second light L2 emitted from the wavelength conversion layer 130 are reflected by the wall 150.

[0041] In particular, the brightness of the incident second light L2 increases toward a region of the inner surface 150b of the wall 150 that is adjacent to the wavelength conversion layer 130. Therefore, the second light L2 is more likely to propagate into the wall 150 from a region of the inner surface 150b of the wall 150 that is adjacent to the wavelength conversion layer 130. In this embodiment, the wall 150 surrounds the light-transmitting plate 140 provided above the wavelength conversion layer 130 such that the upper surface 140a of the light-transmitting plate 140 and the upper surface 150a of the wall 150 are flush with each other, and is located above the upper surface 130a of the wavelength conversion layer 130. Therefore, even if the second light L2 propagates into the wall 150 from a region of the inner surface 150b of the wall 150 that is adjacent to the wavelength conversion layer 130, the propagated second light L2 is attenuated within the wall 150, and the second light L2 is prevented from emitting from the upper surface 150a of the wall 150. As a result, the second light L2 propagated into the wall 150 can be prevented from leaking from the upper surface 150a of the wall 150.

[0042] Furthermore, in this embodiment, the angle θ of the corner c is 90 degrees. Therefore, compared to when the angle θ of the corner c is less than 90 degrees, the thickness t of the corner c (the distance between the upper surface 140a near the corner c and the inner surface 150b) can be made thicker. As a result, even if the second light L2 propagates into the wall 150 from a region of the inner surface 150b of the wall 150 near the corner c, the propagated second light L2 can be attenuated inside the wall 150, and leakage of the second light L2 from the upper surface 150a can be suppressed.

[0043] In this way, suppressing light leakage from the upper surface 150a of the wall 150 can prevent the peripheral region S2 surrounding the region S1 directly above the light-emitting element 120 and the wavelength conversion layer 130 from becoming brighter. This increases the contrast between the region S1 directly above the light-emitting element 120 and the wavelength conversion layer 130 and the peripheral region S2.

[0044] Furthermore, in this embodiment, an area including the upper end 150t on the inner surface 150b of the wall 150 is perpendicular to the upper surface 110a of the substrate 110. This allows the light distribution angle to be narrow, thereby improving the brightness of the light emitting device 100.

[0045] FIG. 4B is an enlarged view of an end surface illustrating a part of the light emitting element, a part of the wavelength conversion layer, and a part of the light-transmitting plate in FIG. 2A, illustrating an example of a light path. In this embodiment, the wavelength conversion particles 131 are covered with the glass layer 132. Therefore, when the first light L1 emitted from the light emitting element 120 and the second light L2 emitted from the wavelength conversion layer 130 attempt to enter the glass layer 132 through the air layer 130k in the wavelength conversion layer 130, there is a high probability that these lights will be reflected at the interface between the air layer 130k and the glass layer 132. This prevents the first light L1 and the second light L2 from propagating laterally in the wavelength conversion layer 130, and they are emitted from the region directly above the light emitting element 120 and the wavelength conversion layer 130. This increases the contrast between the region S1 directly above the light emitting element 120 and the wavelength conversion layer 130 and the surrounding region S2.

[0046] Next, a method for manufacturing the light emitting device 100 according to this embodiment will be described. 5A to 5E are diagrams showing a method for manufacturing a light emitting device according to this embodiment.

[0047] 5A, the light emitting element 120 is placed on the substrate 110. In this embodiment, the light emitting element 120 is bonded to the substrate 110 with a conductive bonding member 160. In this embodiment, a light blocking layer 170 is provided between the light emitting element 120 and the substrate 110.

[0048] 5B, a wavelength conversion layer 130 is disposed on the light emitting element 120. The wavelength conversion layer 130 is disposed by spraying a slurry material containing a plurality of wavelength conversion particles 131.

[0049] Specifically, a mask material is provided around the light-emitting element 120, a slurry material is sprayed onto the light-emitting element 120, and the mask material is then removed. The slurry material contains polysilazane, a plurality of wavelength-converting particles 131, and an organic solvent. The organic solvent may be, for example, heptane or dibutyl ether. The organic solvent may not be included. The slurry material does not contain a resin material. Next, the substrate onto which the slurry material has been sprayed is heated or left at room temperature to convert the polysilazane into silica, covering the wavelength-converting particles 131 with a glass layer 132 containing silica and forming air layers 130k between the wavelength-converting particles 131. In this way, the wavelength-converting layer 130 is formed on the light-emitting element 120.

[0050] The method for disposing the wavelength conversion layer is not limited to the above. For example, the sprayed slurry may contain a binder made of a resin material such as a silicone resin, without containing polysilazane. The wavelength conversion layer may also be disposed by electrostatic adhesion between wavelength conversion particles and between the wavelength conversion particles and the light-emitting element.

[0051] 5C , a light-transmitting plate 140 is placed on the wavelength conversion layer 130. The light-transmitting plate 140 is held by a holder 141 and is not bonded to the wavelength conversion layer 130 with an adhesive or the like. That is, the light-transmitting plate 140 is placed with an air layer 130k interposed between it and the wavelength conversion layer 130.

[0052] The light-transmitting plate 140 is disposed so that its upper surface 140a and lower surface 140b are parallel to the upper surface 110a of the substrate 110. The light-transmitting plate 140 is disposed at a position overlapping the wavelength conversion layer 130 and the three light-emitting elements 120 in a top view. With the light-transmitting plate 140 disposed on the wavelength conversion layer 130, the light-emitting elements 120 and the wavelength conversion layer 130 can be seen from above the light-transmitting plate 140. This makes it easy to position the light-transmitting plate 140 relative to the light-emitting elements 120 and the wavelength conversion layer 130.

[0053] Next, as shown in FIG. 5D, uncured light reflecting material 150F is provided so as to surround wavelength conversion layer 130 and light-transmitting plate 140.

[0054] The uncured light-reflecting material 150F includes a base material made of an uncured resin material and a filler made of a light-reflecting material. The resin material of the light-reflecting material 150F may be a thermosetting resin such as a silicone resin or an epoxy resin. The light-reflecting material of the light-reflecting material 150F may be silicon oxide (SiO2), titanium oxide (TiO2), aluminum (Al), silver (Ag), or the like. The light-reflecting material 150F may further include a thickener. "Uncured" means that the light-reflecting material 150F is at least not completely cured and is flexible enough to be deformed to fit the shape of the light-transmitting plate 140. "Cured light-reflecting material 150F" means that the light-reflecting material 150F is completely cured, and corresponds to the wall 150.

[0055] When providing the light-reflecting material 150F, a frame member 180 that surrounds the light-transmitting plate 140 and the wavelength conversion layer 130 may be provided at a position away from the light-transmitting plate 140 and the wavelength conversion layer 130, and the light-reflecting material 150F may be provided between the light-transmitting plate 140 and the wavelength conversion layer 130 and the frame member 180.

[0056] When the upper end of the inner surface 150Fb of the uncured light reflecting material 150F is located lower than the upper end of the side surface 140c of the light-transmitting plate 140, the uncured light reflecting material 150F wets and spreads upward on the side surface 140c, and the upper surface 150Fa of the uncured light reflecting material 150F is recessed in the direction approaching the substrate 110. In this case, the angle θ of the corner c of the cured light reflecting material 150F (i.e., the wall 150) becomes smaller than 90 degrees. Therefore, in this embodiment, the uncured light reflecting material 150F is provided so that the upper end of the inner surface 150Fb of the uncured light reflecting material 150F is at the same position in the up-down direction as the upper end of the upper surface 140a of the light-transmitting plate 140. This makes it possible to prevent the angle θ of the corner c from becoming less than 90 degrees.

[0057] Furthermore, in this embodiment, the upper surface 150Fa of the uncured light reflecting material 150F is flush with the upper surface 150a of the light-transmitting plate 140 and the upper surface 180a of the frame member 180. This allows the upper surface 150a of the cured light reflecting material 150F (i.e., the wall 150) to be parallel to the upper surface 110a of the substrate 110. Note that if it is expected that the upper surface 150a of the cured light reflecting material 150F will be pulled closer to the substrate 110 than the upper surface 150Fa of the uncured light reflecting material 150F, the uncured light reflecting material 150F may be provided so that the upper surface 150Fa of the uncured light reflecting material 150F is convex in a direction away from the substrate 110. In this case, the upper surface 150Fa may be flattened by polishing or the like after the light reflecting material 150F is cured.

[0058] Next, the light reflecting material 150F is cured. If the base material constituting the light reflecting material 150F is a thermosetting resin, the light reflecting material 150F is cured by being heated. The heating temperature is, for example, 150°C or higher and 200°C or lower. However, the curing method can be selected appropriately depending on the material constituting the light reflecting material 150F. For example, the resin in the light reflecting material 150F may be made of an ultraviolet curing resin and cured by ultraviolet light.

[0059] 5E, the holder 141 and the frame member 180 are removed from the substrate 110. As a result, the light-emitting device 100 is formed in which the upper part of the wavelength conversion layer 130 has unevenness due to the wavelength converting particles 131 and an air layer 130k is interposed between the wavelength conversion layer 130 and the light-transmitting plate 140.

[0060] 6A and 6B are diagrams showing a method for manufacturing a light emitting device according to a reference example. 6A , in the manufacturing method of a light-emitting device according to the reference example, an adhesive 190 is placed on the wavelength conversion layer 130, and then the light-transmitting plate 140 is placed on the wavelength conversion layer 130. Therefore, the light-transmitting plate 140 is bonded to the wavelength conversion layer 130 by the adhesive 190. However, when the light-transmitting plate 140 is pressed against the wavelength conversion layer 130 to bond the light-transmitting plate 140 to the wavelength conversion layer 130, the adhesive 190 is crushed, and the plurality of wavelength conversion particles 131 may protrude from between the light-transmitting plate 140 and the light-emitting element 120 together with the adhesive 190.

[0061] Therefore, when the light reflecting material 150F is provided, as shown in FIG. 6B , depressions 150Fk are formed on the inner surface 150Fb of the light reflecting material 150F due to portions of the wavelength converting particles 131 that protrude from between the light-transmitting plate 140 and the light-emitting element 120 together with the adhesive 190. These depressions 150Fk remain even after the light reflecting material 150F is cured. Thus, when the adhesive 190 is provided, some of the wavelength converting particles 131 arranged on the light-emitting element 120 move to positions outside the area directly above the light-emitting element 120. This reduces the number of wavelength converting particles 131 arranged on the light-emitting element 120, thereby reducing the light extraction efficiency. Furthermore, when such depressions 150Fk are provided on a wall, the second light L2 emitted from the wavelength converting particles 131 located within the depressions 150Fk may propagate into the wall and then exit from the upper surface of the wall.

[0062] In contrast, in this embodiment, the adhesive 190 is not disposed between the light-transmitting plate 140 and the wavelength conversion layer 130 during manufacturing. Therefore, by disposing the light-transmitting plate 140, it is possible to prevent some of the wavelength conversion particles 131 disposed on the light-emitting element 120 from migrating to positions outside the region directly above the light-emitting element 120. As a result, it is possible to improve the light extraction efficiency. Because the adhesive 190 is not disposed between the light-transmitting plate 140 and the wavelength conversion layer 130 during manufacturing, an air layer 130k is interposed between the wavelength conversion layer 130 and the light-transmitting plate 140 in the light-emitting device 100 thus formed.

[0063] Next, the effects of this embodiment will be described. In the light-emitting device 100 according to this embodiment, the wall 150 surrounds the wavelength conversion layer 130 and the light-transmitting plate 140. Therefore, the upper surface 150a of the wall 150 is located higher than the upper surface 130a of the wavelength conversion layer 130. This makes it possible to provide a light-emitting device 100 that can suppress light leakage from the upper surface 150a of the wall 150. This also makes it possible to increase the contrast between the region S1 directly above the light-emitting element 120 and the wavelength conversion layer 130 and the surrounding region S2.

[0064] In this embodiment, the upper portion of the wavelength conversion layer 130 has irregularities due to the wavelength conversion particles 131, and an air layer 130k is provided between the wavelength conversion layer 130 and the light-transmitting plate 140. Therefore, the first light L1 and the second light L2 are likely to be reflected at the interface between the irregularities due to the wavelength conversion particles 131 on the upper portion of the wavelength conversion layer 130 and the air layer 130k. This inhibits the first light L1 and the second light L2 from propagating laterally within the wavelength conversion layer 130, causing them to exit from the region directly above the light-emitting element 120 and the wavelength conversion layer 130. This increases the contrast between the region S1 directly above the light-emitting element 120 and the wavelength conversion layer 130 and the surrounding region S2. Furthermore, no adhesive 190 is provided between the wavelength conversion layer 130 and the light-transmitting plate 140. Therefore, when the light-transmitting plate 140 is disposed on the wavelength conversion layer 130 during manufacturing, the wavelength converting particles 131 can be prevented from spilling out from between the light-transmitting plate 140 and the light-emitting element 120. This improves the light extraction efficiency. Furthermore, since the air layer 130k is provided between the wavelength conversion layer 130 and the light-transmitting plate 140, the upper and / or lower surfaces of the light-transmitting plate 140 can be surface-treated to have a convex, concave, or uneven shape. Having two surfaces, the upper and lower surfaces, that can be surface-treated facilitates optical control.

[0065] Furthermore, the side surface 140c of the light-transmitting plate 140 is perpendicular to the upper surface 110a of the substrate 110. This further increases the contrast between the region S1 directly above the light-emitting element 120 and wavelength conversion layer 130 and the surrounding region S2.

[0066] Furthermore, the upper surface 150a of the wall 150 is parallel to the upper surface 110a of the substrate 110. Therefore, the thickness t of the corner portion c can be made thicker than when the upper surface 150a of the wall 150 is concave in the direction approaching the upper surface 110a of the substrate 110. This makes it possible to suppress light leakage from the upper surface 150a of the wall 150.

[0067] The wavelength conversion layer 130 also has a glass layer 132 that covers the surfaces of the wavelength conversion particles 131. The wavelength conversion particles 131 are bonded to each other via the glass layer 132, and air layers 130k are formed between the wavelength conversion particles 131. This further increases the contrast between the region S1 directly above the light emitting element 120 and the wavelength conversion layer 130 and the surrounding region S2.

[0068] In addition, in the manufacturing method of the light emitting device 100 according to this embodiment, first, a light emitting element 120 that emits a first light is placed on a substrate. Next, a wavelength conversion layer 130 having a plurality of wavelength conversion particles 131 that convert the wavelength of a portion of the first light L1 and emit a second light L2 is disposed on the light emitting element 120 so that the upper portion has unevenness due to the wavelength conversion particles 131. Next, a light-transmitting plate 140 is disposed above the wavelength conversion layer 130 so that an air layer 130k is formed between the wavelength conversion layer 130 and the light-transmitting plate 140. Next, an uncured light-reflecting material 150F is provided so as to surround the wavelength conversion layer 130 and the light-transmitting plate 140. Next, a wall 150 is formed by curing the light-reflecting material 150F. This makes it possible to realize a light emitting device 100 that improves light extraction efficiency while suppressing light leakage from the upper surface 150a of the wall 150.

[0069] Furthermore, in the manufacturing method for the light emitting device 100 according to this embodiment, in the step of providing the light reflecting material 150F, the light reflecting material 150F is provided so that the upper end of the inner surface 150Fb is at the same position in the up-down direction as the upper end of the side surface 140c of the light-transmitting plate 140. Therefore, the angle θ of the corner c between the upper surface 150a and the inner surface 150b of the hardened light reflecting material 150F (wall 150) can be made 90 degrees or more.

[0070] <Second embodiment> Next, a second embodiment will be described. FIG. 7 is an end view showing the light emitting device according to this embodiment. The light emitting device 200 according to this embodiment differs from the light emitting device 100 according to the first embodiment in that the upper surface 250a of the wall 250 is not parallel to the upper surface 110a of the substrate 110. In the following description, in principle, only the differences from the first embodiment will be described. Matters other than those described below are the same as those in the first embodiment.

[0071] The configuration of the wall 250 is similar to that of the wall 150 in the first embodiment, except for the shape of the upper surface 250a. The upper surface 250a of the wall 250 is a curved surface that is convex in a direction away from the substrate 110. In this case, the angle θ of the corner c between the upper surface 250a and the inner surface 250b of the wall 250 is greater than 90 degrees and less than 180 degrees. Here, the angle θ is the angle between the inner surface 250b and a tangent L to the upper surface 250a that passes through the upper end 250t of the inner surface 250b. As such, the angle θ may be greater than 90 degrees. In this case, the thickness t of the corner c can be further increased. Therefore, even if the second light L2 propagates into the wall 250 from a region of the inner surface 250b of the wall 250 near the corner c, the propagated second light L2 can be attenuated, and leakage of the second light L2 from the upper surface 250a can be suppressed.

[0072] Next, a method for manufacturing the light emitting device 200 according to this embodiment will be described. FIG. 8 is a diagram showing a method for manufacturing a light emitting device according to this embodiment. The method for manufacturing the light emitting device 200 according to this embodiment differs from the method for manufacturing the light emitting device 100 according to the first embodiment in the step of providing a light reflecting material 250F.

[0073] After providing the light-transmitting plate 140 as shown in FIG. 5C, as shown in FIG. 8, an uncured light-reflecting material 250F is provided so that its upper surface 250a after curing is convex in a direction away from the upper surface 110a of the substrate 110. Like the light-reflecting material 150F in the first embodiment, the uncured light-reflecting material 250F includes a base material made of an uncured resin material and a filler made of a light-reflective material. Specifically, the uncured light-reflecting material 250F is provided so that its upper surface 250Fa is convex in a direction away from the upper surface 110a of the substrate 110 due to surface tension. As a result, the upper surface 250a of the light-reflecting material 250F after curing is convex in a direction away from the upper surface 110a of the substrate 110. The subsequent procedures are the same as those in the first embodiment.

[0074] Next, the effects of this embodiment will be described. In this embodiment, the upper surface 250a of the wall 250 is convex in a direction away from the substrate 110. Therefore, the thickness t of the corner c can be made even thicker. As a result, even if the second light L2 propagates into the wall 250 from a region of the inner surface 250b of the wall 250 near the corner c, the propagated second light L2 can be attenuated, and leakage of the second light L2 from the upper surface 250a can be suppressed.

[0075] <Third embodiment> Next, a third embodiment will be described. FIG. 9 is an end view showing the light emitting device according to this embodiment. The light emitting device 300 according to this embodiment differs from the light emitting device 100 according to the first embodiment in the configuration of the wall 350.

[0076] The wall 350 has a main body portion 351 and a filling portion 352 . The main body 351 includes a base material made of a resin material and a filler made of a light-reflecting material. The resin material may be a thermosetting resin such as a silicone resin or an epoxy resin. The filler may be a light-reflecting material such as silicon oxide (SiO2), titanium oxide (TiO2), aluminum (Al), or silver (Ag). The main body 351 surrounds the light-emitting element 120, the wavelength conversion layer 130, and the light-transmitting plate 140.

[0077] The surface of the main body 351 includes an upper surface 351a, an inner surface 351b, an outer surface 351c, and a lower surface 351d.

[0078] The upper surface 351a is a curved surface that is concave in the direction approaching the upper surface 110a of the substrate 110. In this embodiment, the inner surface 351b surrounds the light-emitting element 120, the wavelength conversion layer 130, and the light-transmitting plate 140. The inner surface 351b is in contact with the side surfaces of the light-emitting element 120, the lateral ends of the wavelength conversion layer 130, and the side surface 140c of the light-transmitting plate 140. A region of the inner surface 351b that includes at least the uppermost end 351t is in contact with the side surface 140c of the light-transmitting plate 140 and is therefore perpendicular to the upper surface 110a of the substrate 110.

[0079] The outer surface 351c is provided around the periphery of the upper surface 351a. The outer surface 351c is perpendicular to the upper surface 110a of the substrate 110. However, the shape of the outer surface 351c is not particularly limited. For example, the outer surface 351c may be inclined with respect to the Z axis.

[0080] The lower surface 351d is located on the opposite side of the upper surface 351a and is in contact with the upper surface 110a of the substrate 110 in this embodiment.

[0081] Filling portion 352 fills a recess in upper surface 351a of main body 351. Filling portion 352 includes a base material made of a resin material and a filler dispersed in the base material. The resin material may be a thermosetting resin such as silicone resin or epoxy resin. The filler may be a light-reflecting material such as silicon oxide (SiO2), titanium oxide (TiO2), aluminum (Al), or silver (Ag), or a light-absorbing material such as carbon particles made of carbon powder.

[0082] An upper surface 352a of the filling portion 352 is parallel to an upper surface 110a of the substrate 110. However, the filling portion 352 may be convex in a direction away from the substrate 110. Even with this configuration, the angle θ of the corner c between the upper surface 352a and the inner surface 351b of the wall 350 can be set to be equal to or greater than 90 degrees and less than 180 degrees.

[0083] When the filler in the filling portion 352 is a light-reflective material, the density of the filler contained in the filling portion 352 is preferably higher than the density of the filler contained in the main body portion 351. This can further prevent the second light L2 propagated into the wall 350 from leaking out from the upper surface 352a.

[0084] Furthermore, when the filler in the filling portion 352 is a light-absorbing material, the filler in the filling portion 352 can absorb the second light L2 that has propagated into the wall 350. This further prevents the second light L2 that has propagated into the wall 350 from leaking out from the upper surface 352a.

[0085] <Fourth embodiment> Next, a fourth embodiment will be described. FIG. 10 is an end view showing the light emitting device according to this embodiment. The light emitting device 400 according to this embodiment differs from the light emitting device 100 according to the first embodiment in the configuration of the wall 450.

[0086] The wavelength conversion layer 130 is surrounded by a wall 450. The wall 450 has a cylindrical shape. The wall 450 has a first portion 451 and a second portion 452. Each of the first portion 451 and the second portion 452 includes a base material made of a resin material and a plurality of fillers made of a light-reflecting material. The resin material of the wall 450 can be a thermosetting resin such as a silicone resin or an epoxy resin. The light-reflecting material of the wall 450 can be silicon oxide (SiO), titanium oxide (TiO), aluminum (Al), silver (Ag), or the like.

[0087] The density of the filler in the first portion 451 differs from the density of the filler in the second portion 452. The "density of the filler" refers to the mass of the filler contained per unit volume of each of the portions 451 and 452.

[0088] In this embodiment, the first portion 451 surrounds both the light emitting element 120 and the wavelength conversion layer 130. The surface of the first portion 451 includes an inner surface 451a, an outer surface 451b, and a lower surface 451c.

[0089] The inner surface 451a surrounds the light emitting element 120, the wavelength conversion layer 130, and a lower region of the side surface 140c of the light-transmitting plate 140, and is in contact with the side surface of the light emitting element 120, the lateral end of the wavelength conversion layer 130, and the lower region of the side surface 140c of the light-transmitting plate 140. Therefore, the uppermost end 451t of the inner surface 451a is located between the upper surface 130a of the wavelength conversion layer 130 and the upper surface 140a of the light-transmitting plate 140.

[0090] Outer surface 451b is provided around inner surface 451a and is in contact with inner surface 451a and lower surface 451c. Outer surface 451b becomes more distant from inner surface 451a as it goes downward. However, an upper surface may be located between inner surface 451a and outer surface 451b. In this case, outer surface 451b may be perpendicular to upper surface 110a of substrate 110. Lower surface 451c is in contact with upper surface 110a of substrate 110.

[0091] The second portion 452 is provided on and around the first portion 451. The density of the filler contained in the first portion 451 is higher than the density of the filler contained in the second portion 452. Therefore, the light reflectance of the first portion 451 is higher than the light reflectance of the second portion 452.

[0092] The surface of the second portion 452 includes an upper surface 452a, an inner surface 452b, an outer surface 452c, and a lower surface 452d. In this embodiment, the upper surface 452a is a flat surface parallel to the upper surface 110a of the substrate 110. The upper surface 452a is flush with the upper surface 140a of the light-transmitting plate 140. However, the upper surface 452a may be convex in a direction away from the substrate 110.

[0093] The inner surface 452b includes a first region 452s1 located between the upper surface 452a and the upper end 451t, and a second region 452s2 located between the upper end 451t and the lower surface 452d. The first region 452s1 surrounds the light-transmitting plate 140. The first region 452s1 is in contact with the side surface 140c of the light-transmitting plate 140 and is therefore perpendicular to the upper surface 110a of the substrate 110. The second region 452s2 is in contact with the outer surface 451b of the first portion 451.

[0094] The outer surface 452c is provided around the periphery of the upper surface 452a and is in contact with the upper surface 452a and the lower surface 452d. The outer surface 452c is perpendicular to the upper surface 110a of the substrate 110. However, the outer surface 452c may be inclined with respect to the Z axis. The lower surface 452d is in contact with the upper surface 110a of the substrate 110.

[0095] Thus, an upper surface 450a of the entire wall 450 is made up of an upper surface 452a of the second portion 452. An inner surface 450b of the entire wall 450 is made up of an inner surface 451a of the first portion 451 and a first region 452s1 of the second portion 452. An outer surface 450c of the entire wall 450 is made up of an outer surface 452c of the second portion 452. A lower surface 450d of the entire wall 450 is made up of a lower surface 451c of the first portion 451 and a lower surface 452d of the second portion 452.

[0096] In this embodiment, the upper surface 450a is parallel to the upper surface 110a of the substrate 110, and a region (first region 452s1) of the inner surface 450b including the upper end 452t is perpendicular to the upper surface 110a of the substrate 110. Therefore, the angle θ of the corner c between the upper surface 450a and the inner surface 450b is 90 degrees. However, the upper surface 450a may be a curved surface that is convex in a direction away from the substrate 110. In other words, the angle θ may be greater than 90 degrees and less than 180 degrees.

[0097] Next, the operation of the light emitting device 400 according to this embodiment will be described. The brightness of the incident second light L2 increases in a region on the inner surface 450b of the wall 450 that is closer to the wavelength conversion layer 130. Therefore, the second light L2 is more likely to propagate through the portion of the wall 450 that is adjacent to the wavelength conversion layer 130. In this embodiment, the reflectance of the first portion 451 adjacent to the wavelength conversion layer 130 is higher than the reflectance of the second portion 452. Therefore, the second light L2 can be prevented from propagating through the first portion 451 that is adjacent to the wavelength conversion layer 130.

[0098] Next, a method for manufacturing the light emitting device 400 according to this embodiment will be described. 11A and 11B are diagrams showing a method for manufacturing a light emitting device according to this embodiment.

[0099] First, as shown in FIG. 5C, a light-transmitting plate 140 is placed above the wavelength conversion layer 130, and then, as shown in FIGS. 11A and 11B, an uncured light-reflecting material 450F is provided to surround the wavelength conversion layer 130 and the light-transmitting plate 140.

[0100] Uncured light reflecting material 450F includes a first member 451F and a second member 452F. First member 451F and second member 452F each include a base material made of an uncured resin material and a filler made of a light-reflective material. First member 451F and second member 452F have different filler concentrations. First member 451F is a portion that will become first portion 451 of wall 450 when cured. Second member 452F is a portion that will become second portion 452 of wall 450 when cured.

[0101] 11A , a first member 451F is provided to surround the wavelength conversion layer 130 and the lower region of the side surface 140c of the light-transmitting plate 140 and to be in contact with the lower region of the side surface 140c of the light-transmitting plate 140. The viscosity of the uncured first member 451F is preferably such that the uncured first member 451F does not flow into the wavelength conversion layer 130 after being provided around the wavelength conversion layer 130 and the light-transmitting plate 140. The viscosity of the uncured first member 451F is preferably, for example, 450 Pa·s or more and 1000 Pa·s or less. This allows the inner surface 451Fb of the uncured first member 451F to be in contact with the lower region of the side surface 140c of the light-transmitting plate 140, while preventing the first member 451F from flowing into the wavelength conversion layer 130.

[0102] Next, the first member 451F is semi-cured. Note that the first member 451F does not necessarily have to be semi-cured.

[0103] 11B, second member 452F is provided on first member 451F and around first member 451F. The viscosity of uncured second member 452F is lower than the viscosity of uncured first member 451F. There are no particular limitations on the method for making the viscosity of second member 452F lower than the viscosity of first member 451F. Examples include a method of making the concentration of filler contained in second member 452F lower than the concentration of filler contained in first member 451F, or a method of adding a smaller amount of thickener to second member 452F than the amount of thickener added to first member 451F.

[0104] The viscosity of the uncured second member 452F is preferably such that the second member 452F can flow along the side surface 140c of the light-transmitting plate 140. The viscosity of the second member 452F is preferably, for example, 5 Pa·s or more and 250 Pa·s or less. When providing the second member 452F, a frame member 180 that surrounds the light-transmitting plate 140 and the first member 451F may be provided at a position away from the light-transmitting plate 140 and the first member 451F, and the second member 452F may be provided between the light-transmitting plate 140 and the frame member 180.

[0105] In this embodiment, the second member 452F is provided so that the upper surface 450a after curing is parallel to the upper surface 110a of the substrate 110. Specifically, the uncured second member 452F is provided so that the upper end of the inner surface 452Fb of the uncured second member 452F is at the same position as the upper end of the side surface 140c of the light-transmitting plate 140 in the up-down direction.

[0106] As described above, the first member 451F contacts the lower region of the side surface 140c of the light-transmitting plate 140 and surrounds the wavelength conversion layer 130. Therefore, the first member 451F prevents the second member 452F from flowing into the wavelength conversion layer 130, while allowing the second member 452F to flow in accordance with the side surface 140c of the light-transmitting plate 140.

[0107] Next, the light reflecting material 450F (first member 451F and second member 452F) is cured. Next, the holder 141 and the frame member 180 are removed from the substrate 110. As a result, the light emitting device 400 in which the first portion 451 and the second portion 452 are provided on the wall 450 is formed.

[0108] Next, the effects of this embodiment will be described. In the light-emitting device 400 according to this embodiment, the wall 450 includes a base material made of a resin material and a filler made of a light-reflective material dispersed in the base material. The wall 450 has a first portion 451 surrounding the wavelength conversion layer 130 and a second portion 452 provided on the first portion 451 and around the first portion 451. The density of the filler contained in the first portion 451 is higher than the density of the filler contained in the second portion 452. This allows the reflectance of the first portion 451 to be higher than the reflectance of the second portion 452. As a result, propagation of the second light L2 into the first portion 451 adjacent to the wavelength conversion layer 130 can be suppressed.

[0109] Furthermore, in the manufacturing method of the light emitting device 400 according to this embodiment, the light reflecting material 450F has a first member 451F provided to surround the wavelength conversion layer 130, and a second member 452F provided on the first member 451F and around the first member 451F. The viscosity of the first member 451F is higher than the viscosity of the second member 452F. Therefore, the first member 451F prevents the second member 452F from flowing into the wavelength conversion layer 130, while allowing the second member 452F to easily flow in accordance with the shape of the side surface 140c of the light-transmitting plate 140.

[0110] <Fifth embodiment> Next, a fifth embodiment will be described. FIG. 12 is an end view showing the light emitting device according to this embodiment. The light emitting device 500 according to this embodiment differs from the light emitting device 400 according to the fourth embodiment in the configuration of the wall 550. In the following description, in principle, only the differences from the fourth embodiment will be described. The matters other than those described below are the same as those in the fourth embodiment.

[0111] The wall 550 has a first portion 551, a second portion 552, and a third portion 553. The first portion 551 surrounds both the light-emitting element 120 and the wavelength conversion layer 130. The second portion 552 is provided on and around the first portion 551. The third portion 553 is provided on and around the second portion 552.

[0112] Each of the first portion 551, the second portion 552, and the third portion 553 includes a base material made of a resin material and a filler made of a light-reflective material. The density of the filler included in the first portion 551 is higher than the density of the filler included in the second portion 552. The density of the filler included in the second portion 552 is higher than the density of the filler included in the third portion 553. Therefore, the light reflectance of the first portion 551 is higher than the light reflectance of the second portion 552, and the light reflectance of the second portion 552 is higher than the light reflectance of the third portion 553.

[0113] The surface of the first portion 551 includes an inner surface 551a, an outer surface 551b, and a lower surface 551c. The inner surface 551a surrounds the light emitting element 120, the wavelength conversion layer 130, and a lower region of the side surface 140c of the light-transmitting plate 140, and is in contact with the side surface of the light emitting element 120, the lateral end of the wavelength conversion layer 130, and the lower region of the side surface 140c of the light-transmitting plate 140. Therefore, an upper end 551t, which is the uppermost part of the inner surface 551a, is located between the upper surface 130a of the wavelength conversion layer 130 and the upper surface 140a of the light-transmitting plate 140.

[0114] Outer surface 551b is provided around inner surface 551a and is in contact with inner surface 551a and lower surface 551c. Outer surface 551b becomes more distant from inner surface 551a as it goes downward. However, an upper surface may be located between inner surface 551a and outer surface 551b. In this case, outer surface 551b may be perpendicular to upper surface 110a of substrate 110. Lower surface 551c is in contact with upper surface 110a of substrate 110.

[0115] The surface of the second portion 552 includes an inner surface 552a, an outer surface 552b, and a lower surface 552c. The inner surface 552a surrounds the light-transmitting plate 140 and the first portion 551. An upper end 552t, which is the uppermost end of the inner surface 552a, is located higher than an upper end 551t of the first portion 551. The inner surface 552a has a first region 552s1 located between the upper end 552t and the upper end 551t of the first portion 551, and a second region 552s2 located between the upper end 551t and the lower surface 552c. The first region 552s1 is in contact with the side surface 140c of the light-transmitting plate 140. The second region 552s2 is in contact with the outer surface 551b of the first portion 551.

[0116] The outer surface 552b is provided around the inner surface 552a and is in contact with the inner surface 552a and the lower surface 552c. The upper surface may be located between the inner surface 552a and the outer surface 552b. The lower surface 552c is in contact with the upper surface 110a of the substrate 110.

[0117] The third portion 553 is provided on and around the second portion 552. The surface of the third portion 553 includes an upper surface 553a, an inner surface 553b, an outer surface 553c, and a lower surface 553d. The upper surface 553a is parallel to the upper surface 110a of the substrate 110. However, the upper surface 553a may be convex in a direction away from the substrate 110.

[0118] An upper end 553t of the inner surface 553b, which is located at the uppermost position, is located higher than an upper end 552t of the second portion 552. The inner surface 553b includes a third region 553s1 located between the upper ends 553t and 552t, and a fourth region 553s2 located between the upper end 552t and the lower surface 553d. The third region 553s1 surrounds the light-transmitting plate 140 and is in contact with the side surface 140c of the light-transmitting plate 140. The fourth region 553s2 is in contact with the outer surface 552b of the second portion 552.

[0119] The outer surface 553c is provided around the periphery of the upper surface 553a and is in contact with the upper surface 553a and the lower surface 553d. The outer surface 553c is perpendicular to the upper surface 110a of the substrate 110. However, the outer surface 553c may be inclined with respect to the Z axis. The lower surface 553d is in contact with the upper surface 110a of the substrate 110.

[0120] Thus, upper surface 550a of entire wall 550 is made up of upper surface 553a of third portion 553. Inner surface 550b of entire wall 550 is made up of inner surface 551a of first portion 551, first region 552s1 of second portion 552, and third region 553s1 of third portion 553. Outer surface 550c of entire wall 550 is made up of outer surface 553c of third portion 553. Lower surface 550d of entire wall 550 is made up of lower surface 551c of first portion 551, lower surface 552c of second portion 552, and outer surface 553c of third portion 553.

[0121] In this embodiment, the upper surface 550a is parallel to the upper surface 110a of the substrate 110, and a region (third region 553s1) of the inner surface 550b including the upper end 553t is perpendicular to the upper surface 110a of the substrate 110. Therefore, the angle θ of the corner c between the upper surface 550a and the inner surface 550b is 90 degrees. However, the upper surface 550a may be a curved surface that is convex in the direction away from the substrate 110. In other words, the angle θ may be greater than 90 degrees and less than 180 degrees.

[0122] Next, a method for manufacturing the light emitting device 500 according to this embodiment will be described. 13A to 13C are diagrams showing a method for manufacturing a light emitting device according to this embodiment. The manufacturing method according to this embodiment differs from the manufacturing method for the light emitting device 400 according to the fourth embodiment in the step of providing a light reflecting material 550F.

[0123] The light reflecting material 550F has a first member 551F, a second member 552F, and a third member 553F. Each of the first member 551F, the second member 552F, and the third member 553F includes a base material made of an uncured resin material and a filler made of a light-reflective material. The first member 551F, the second member 552F, and the third member 553F have different filler concentrations. The first member 551F is a portion that becomes a first portion 551 of the wall 550 when cured. The second member 552F is a portion that becomes a second portion 552 of the wall 550 when cured. The third member 553F is a portion that becomes a third portion 553 of the wall 550 when cured. A method of providing the light reflecting material 550F will be described in detail below.

[0124] First, as shown in FIG. 13A, similar to the fourth embodiment, a first member 551F is provided to surround the wavelength conversion layer 130 and the lower region of the side surface 140c of the light-transmitting plate 140 and to be in contact with the lower region of the side surface 140c of the light-transmitting plate 140.

[0125] Next, the first member 551F is semi-cured. Note that the first member 551F does not necessarily have to be semi-cured.

[0126] 13B, the second member 552F is provided on and around the first member 551F. The viscosity of the uncured second member 552F is lower than the viscosity of the uncured first member 551F. Therefore, the first member 551F can prevent the second member 552F from flowing into the wavelength conversion layer 130, while allowing the second member 552F to be in sufficient contact with the side surface 140c of the light-transmitting plate 140.

[0127] Next, the second member 552F is semi-cured. Note that the second member 552F does not necessarily have to be semi-cured.

[0128] Next, as shown in FIG. 13C , a third member 553F is provided on and around the second member 552F. At this time, the third member 553F is provided so that an upper surface 550a thereof after curing is parallel to the upper surface 110a of the substrate 110. The third member 553F may also be provided so that an upper surface 550a thereof after curing is convex in a direction away from the upper surface 110a of the substrate 110. The viscosity of the uncured third member 553F is lower than the viscosity of the uncured second member 552F. Therefore, the third member 553F flows to match the shape of the side surface 140c of the light-transmitting plate 140.

[0129] As described above, before the third member 553F is provided, the first member 551F and the second member 552F are in contact with the side surface 140c of the light-transmitting plate 140 and cover the wavelength conversion layer 130. Therefore, both the first member 551F and the second member 552F can suppress the third member 553F from flowing into the wavelength conversion layer 130, while allowing the third member 553F to deform to fit the side surface 140c of the light-transmitting plate 140.

[0130] Next, the first member 551F, the second member 552F, and the third member 553F are hardened. The subsequent procedures are the same as those in the fourth embodiment.

[0131] Next, the effects of this embodiment will be described. In the light emitting device 500 according to this embodiment, the wall 550 further includes a third portion 553 provided on and around the second portion 552. The density of the filler contained in the third portion 553 is lower than the density of the filler contained in the second portion 552. This makes it possible to make the reflectance of the second portion 552 located closer to the wavelength conversion layer 130 higher than the reflectance of the third portion 553. This further reduces the propagation of the second light L2 through the wall 550.

[0132] Furthermore, the viscosity of the uncured second member 552F during manufacturing is higher than the viscosity of the uncured third member 553F. Therefore, both the first member 551F and the second member 552F can suppress the third member 553F from flowing into the wavelength conversion layer 130, while allowing the third member 553F to deform to fit the side surface 140c of the light-transmitting plate 140.

[0133] In the above embodiment, an example has been described in which the wall 550 has three portions 551, 552, and 553 with different filler densities, but the wall 550 may have four or more portions with different filler densities.

[0134] Sixth Embodiment Next, a sixth embodiment will be described. FIG. 14 is an end view showing the light emitting device according to this embodiment. The light emitting device 600 of this embodiment differs from the light emitting device 100 of the first embodiment in that the light emitting element 620 is an LED in which the growth substrate side of the light emitting element 620 is mounted on the substrate 110 (FU (Face-up) mounting).

[0135] The light-emitting element 620 is placed on the substrate 110. An electrode on the top surface of the light-emitting element 620 is connected to one end of a wire 660. The other end of the wire 660 is connected to an electrode on the substrate 110 (not shown). A light-shielding layer 670 is provided around the light-emitting element 620.

[0136] The light-shielding layer 670 is in contact with the upper surface 110a of the substrate 110. The light-shielding layer 670 includes a base material made of a resin material and a filler dispersed in the base material. The base material of the light-shielding layer 670 may be a thermosetting resin such as a silicone resin or an epoxy resin. The filler of the light-shielding layer 670 may be a light-reflective material such as titanium oxide (TiO2). The wall 650 is provided on the light-shielding layer 670, and has a portion of the wire 660 buried therein.

[0137] In this way, the light emitting element 620 may be FU-mounted. Furthermore, the wall 650 only needs to surround at least the wavelength conversion layer 130, and does not necessarily have to surround the light emitting element 620.

[0138] The embodiments of the present disclosure can be used for various lighting light sources, vehicle-mounted light sources, and the like. [Explanation of symbols]

[0139] 100, 200, 300, 400, 500, 600: Light-emitting device 110: Substrate 110a:Top surface 110b: Bottom surface 120, 620: Light-emitting element 130: Wavelength conversion layer 130a:Top surface 130k: air layer 131: Wavelength conversion particles 132: Glass layer 140: Translucent plate 140a:Top surface 140b: Bottom surface 140c: Side 141: Holder 150, 250, 350, 450, 550: Wall 150a, 250a, 450a, 550a: Top 150b, 250b, 450b, 550b: inner surface 150c, 450c, 550c: External surface 150d, 450d, 550d: Bottom surface 150t, 250t: Upper end 150F, 250F, 450F, 550F: Light reflection material 150Fa, 250Fa: Upper surface 150Fb: Inner surface 150Fk: Depression 160: Joining member 170: Light shielding layer 180: Frame member 180a: Upper surface 190: Adhesive 351: Main body part 351a: Upper surface 351b: Inner surface 351c: Outer surface 351d: Lower surface 351t: Upper end 352: Filling part 352a: Upper surface 451, 551: First part 451a, 551a: Inner surface 451b, 551b: Outer surface 451c, 551c: Lower surface 451t, 551t: Upper end 451F, 551F: First member 451Fb: Inner surface[[ID=4,7]] 452, 552: Second part 452a: Upper surface 452b, 552a: Inner surface 452c, I552b: Outer surface 452d, 552c: Lower surface 452s1, 552s1: First region 452s2, 552s2: Second region 452t, 552t: Upper end 452F, 552F: Second member 452Fa: Upper surface 452Fb: Inner surface 553: Third part 553a: Upper surface 553b: Inner surface 553c: Outer surface 553d: Lower surface 553s1: Third region 553s2: Fourth region 553t: Upper end 553F: Third member 660: Wire 670: Light blocking layer L: Tangent L1: 1st light L2: Second light S1: Area directly above the transparent plate S2: Peripheral area c: corner t: Thickness θ: Angle

Claims

1. A substrate; a light emitting element provided on the substrate and configured to emit a first light; a wavelength conversion layer provided on the light emitting element, the wavelength conversion layer including a plurality of wavelength conversion particles configured to convert a wavelength of a portion of the first light and emit a second light; a light-transmitting plate provided above the wavelength conversion layer; a wall surrounding the wavelength conversion layer and the light-transmitting plate, the inner surface of the wall being in contact with a side surface of the light-transmitting plate, the wall including a light-reflecting material; Equipped with an upper portion of the wavelength conversion layer has irregularities due to the wavelength conversion particles; an air layer is provided between the wavelength conversion layer and the light-transmitting plate, the wall includes a base material made of a resin material, and a filler made of the light-reflective material dispersed in the base material; the wall has a first portion surrounding the wavelength conversion layer, a second portion provided on and around the first portion, and a third portion provided on and around the second portion, The density of the filler contained in the first portion is higher than the density of the filler contained in the second portion, A light emitting device, wherein a density of the filler contained in the third portion is lower than a density of the filler contained in the second portion.

2. A substrate; a light emitting element provided on the substrate and configured to emit a first light; a wavelength conversion layer provided on the light emitting element, the wavelength conversion layer including a plurality of wavelength conversion particles configured to convert a wavelength of a portion of the first light and emit a second light; a light-transmitting plate provided above the wavelength conversion layer; a wall surrounding the wavelength conversion layer and the light-transmitting plate, the inner surface of the wall being in contact with a side surface of the light-transmitting plate, the wall including a light-reflecting material; Equipped with an upper portion of the wavelength conversion layer has irregularities due to the wavelength conversion particles; an air layer is provided between the wavelength conversion layer and the light-transmitting plate, the wall includes a base material made of a resin material, and a filler made of the light-reflective material dispersed in the base material; the wall has a first portion surrounding the wavelength conversion layer and a second portion disposed on and around the first portion; The density of the filler contained in the first portion is higher than the density of the filler contained in the second portion, The first portion is in contact with the wavelength conversion layer, and the second portion is in contact with the light-transmitting plate.

3. the wall further includes a third portion disposed on and around the second portion; The light emitting device according to claim 2 , wherein a density of the filler contained in the third portion is lower than a density of the filler contained in the second portion.

4. 4. The light emitting device according to claim 1, wherein the side surface of the light-transmitting plate is perpendicular to the upper surface of the substrate.

5. 5. The light emitting device according to claim 1, wherein the upper surface of the wall is convex in a direction away from the substrate.

6. 5. The light emitting device according to claim 1, wherein an upper surface of the wall is parallel to an upper surface of the substrate.

7. the wavelength-converting layer further comprises a glass layer covering surfaces of the wavelength-converting particles, the wavelength-converting particles are bonded to each other via the glass layer, 7. The light emitting device according to claim 1, wherein an air layer is formed between the wavelength conversion particles.

8. 8. The light emitting device according to claim 1, wherein at least one of the upper and lower surfaces of the light-transmitting plate is subjected to a surface treatment.

9. a step of placing a light emitting element that emits a first light on a substrate; a step of disposing a wavelength conversion layer having a plurality of wavelength conversion particles that convert a wavelength of a part of the first light and emit a second light on the light emitting element, such that an upper portion of the wavelength conversion layer has unevenness due to the wavelength conversion particles; placing a light-transmitting plate above the wavelength conversion layer so as to have an air gap between the light-transmitting plate and the wavelength conversion layer; providing an uncured light reflecting material to surround the wavelength conversion layer and the light transmitting plate; forming a wall by hardening the light reflecting material; Equipped with The light reflecting material is A first member provided to surround the wavelength conversion layer; a second member provided on and around the first member; a third member provided on and around the second member; and having The viscosity of the first member is higher than the viscosity of the second member, A method for manufacturing a light emitting device, wherein the viscosity of the third member is lower than the viscosity of the second member.

10. a step of placing a light emitting element that emits a first light on a substrate; a step of disposing a wavelength conversion layer having a plurality of wavelength conversion particles that convert a wavelength of a part of the first light and emit a second light on the light emitting element, such that an upper portion of the wavelength conversion layer has unevenness due to the wavelength conversion particles; placing a light-transmitting plate above the wavelength conversion layer so as to have an air gap between the light-transmitting plate and the wavelength conversion layer; providing an uncured light reflecting material to surround the wavelength conversion layer and the light transmitting plate; forming a wall by hardening the light reflecting material; Equipped with The light reflecting material is A first member provided to surround the wavelength conversion layer; a second member provided on and around the first member; having The viscosity of the first member is higher than the viscosity of the second member, The first member is in contact with the wavelength conversion layer, and the second member is in contact with the light-transmitting plate.

11. The light reflecting material further includes a third member provided on the second member and around the second member, The method for manufacturing a light emitting device according to claim 10 , wherein the third member has a lower viscosity than the second member.

12. A method for manufacturing a light-emitting device described in any one of claims 9 to 11, wherein in the process of providing the light-reflecting material, the light-reflecting material is provided so that the upper end of its inner surface is at the same position in the vertical direction as the upper end of the side surface of the light-transmitting plate.

13. The step of disposing the wavelength conversion layer includes:

13. The method for manufacturing a light emitting device according to claim 9, further comprising the step of spraying a slurry material containing the plurality of wavelength conversion particles onto the light emitting element.

14. The slurry material further includes polysilazane, The step of disposing the wavelength conversion layer includes:

14. The method for manufacturing a light-emitting device according to claim 13, further comprising the step of converting the polysilazane into silica by heating or leaving at room temperature the substrate onto which the slurry material has been sprayed, thereby coating the wavelength-converting particles with a glass layer containing the silica and forming an air layer between the wavelength-converting particles.

15. 15. The method for manufacturing a light emitting device according to claim 9, wherein at least one of the upper and lower surfaces of the light transmitting plate is subjected to a surface treatment.

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