Light-emitting device

Abstract

To provide a light-emitting device excellent in heat dissipation.SOLUTION: A light-emitting device has: a light-emitting part having a light-emitting element and an insulative first coating member which is disposed on a lateral face of the light-emitting element; a substrate on which the light-emitting part is disposed; and a second coating member which is disposed so as to come into contact with the periphery of the first coating member on the substrate. The second coating member has: an insulative first layer; and a second layer, disposed on the first layer, which contains metal particles.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, light emitting devices having a covering member disposed on the side surface of a light emitting element to increase the light extraction efficiency from the light emitting element have been known. For example, Patent Document 1 discloses a light emitting device having a first covering member disposed on the side surface of a light emitting element and a translucent member, and a second covering member disposed around the first covering member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-168374 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the embodiment of the present disclosure is to provide a light emitting device with excellent heat dissipation properties. [Means for solving the problem]

[0005] A light emitting device according to an embodiment of the present disclosure has a light emitting section including a light emitting element and a first covering member having insulating properties and arranged on a side of the light emitting element, a substrate on which the light emitting element is arranged, and a second covering member arranged in contact with the periphery of the first covering member on the substrate, the second covering member having a first layer having insulating properties and a second layer containing metal particles and arranged on the first layer. Effect of the Invention

[0006] According to the embodiments of the present disclosure, a light emitting device with excellent heat dissipation properties can be provided. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic top view of a light emitting device according to a first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is an enlarged view of the periphery of the light-emitting portion in FIG. [Figure 4] FIG. 6 is a schematic top view of a light emitting device according to a second embodiment. [Diagram 5] 5 is a schematic cross-sectional view taken along line VV in FIG. 4. [Figure 6A] FIG. 1 is a first diagram showing a method for manufacturing a light emitting device according to a second embodiment. [Figure 6B] FIG. 2 is a second diagram showing the method for manufacturing the light emitting device according to the second embodiment. [Figure 6C] FIG. 3 is a third diagram showing the method for manufacturing the light emitting device according to the second embodiment. [Figure 7] FIG. 11 is a schematic cross-sectional view of a light emitting device according to a third embodiment. [Figure 8] FIG. 11 is a schematic cross-sectional view of a light emitting device according to a fourth embodiment. [Figure 9A] FIG. 13 is a first diagram showing a method for manufacturing a substrate provided in a light emitting device according to a fourth embodiment. [Figure 9B] FIG. 2 is a second diagram showing the method for manufacturing the substrate included in the light emitting device according to the fourth embodiment. [Figure 9C] FIG. 13 is a third diagram showing a method for manufacturing a substrate provided in the light emitting device according to the fourth embodiment. [Figure 9D] FIG. 4 is a fourth diagram showing a method for manufacturing a substrate provided in the light emitting device according to the fourth embodiment. [Figure 10] FIG. 13 is a schematic top view of a light emitting device according to a fifth embodiment. [Figure 11] 11 is a schematic cross-sectional view taken along line XI-XI in FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The light-emitting device according to the embodiment of the present disclosure will be described in detail with reference to the drawings. However, the following embodiments are merely illustrative of the light-emitting device for embodying the technical idea of ​​the present embodiment, and are not limited to the following. Furthermore, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments are merely illustrative examples, and are not intended to limit the scope of the present disclosure, unless otherwise specified. The sizes, positional relationships, etc. of the components shown in each drawing may be exaggerated to clarify the explanation. Furthermore, in the following explanation, the same names and symbols indicate the same or similar components, and detailed explanations will be omitted as appropriate.

[0009] In addition, in the following description, terms indicating specific directions or positions (for example, "upper", "lower", and other terms including these terms) may be used. These terms are used merely to make relative directions or positions in the reference drawings easier to understand. In addition, end views showing only the cut surface may be used as cross-sectional views. In the following description, "higher" used to describe positional relationships means that the object is located above a reference object, and "lower" used to describe positional relationships means that the object is located below a reference object.

[0010] In each drawing, a Cartesian coordinate system having an X-axis, a Y-axis, and a Z-axis is used to express directions. The X-axis, the Y-axis, and the Z-axis are mutually orthogonal. The Z direction along the Z-axis indicates a direction along a normal to a light-emitting surface of the light-emitting device according to the embodiment.

[0011] The direction in which the arrow points in the X direction is denoted as the +X side, and the opposite direction to the +X side is denoted as the -X side. The direction in which the arrow points in the Y direction is denoted as the +Y side, and the opposite direction to the +Y side is denoted as the -Y side. The direction in which the arrow points in the Z direction is denoted as the +Z side, and the opposite direction to the +Z side is denoted as the -Z side. In this specification, "upper" corresponds to the +Z side, and "lower" corresponds to the -Z side. A top view refers to viewing an object from above, that is, the +Z side. However, these do not limit the orientation of the light-emitting device according to the embodiment when it is used, and the orientation of the light-emitting device according to the embodiment is arbitrary.

[0012] In the following embodiments, "along the X-axis, Y-axis, and Z-axis" includes an object having a tilt within a range of ±10° with respect to these axes. In the embodiments, "orthogonal" may include an error within ±10° with respect to 90°.

[0013] In addition, in this specification or claims, when there are multiple elements of a certain type and each element needs to be expressed with a distinction, the elements may be distinguished by adding "first," "second," etc. to the beginning of the element. In addition, the objects to be distinguished may differ between this specification and the claims. Therefore, even if an element with the same notation as this specification is described in the claims, the object identified by this element may not be the same between this specification and the claims.

[0014] For example, when there are elements distinguished by the notation "first", "second", and "third" in this specification, and the elements marked with "first" and "third" in this specification are described in the claims, or when the elements marked with "first" and the elements not marked with a specific ordinal number are described in the claims, the elements may be distinguished by the notation "first" and "second" in the claims for the sake of readability. In this case, the elements marked with "first" and "second" in the claims refer to the elements marked with "first" and "third" in this specification, or the elements not marked with a specific ordinal number, respectively. Note that this rule is not limited to the application of elements, and can be applied rationally and flexibly to other objects as well.

[0015] [First embodiment] <Configuration of the Light Emitting Device According to the First Embodiment> The configuration of a light emitting device 100 according to a first embodiment will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a schematic top view showing an example of the light emitting device 100. Fig. 2 is a schematic cross-sectional view showing an example of the light emitting device 100 taken along line II-II in Fig. 1. Fig. 3 is an enlarged view of the periphery of the light emitting section 1 in Fig. 2.

[0016] As shown in Fig. 1 and Fig. 2, the light emitting device 100 has a light emitting section 1 including a light emitting element 11 and a first covering member 12 having insulating properties and disposed on a side surface 111 of the light emitting element 11. The light emitting device 100 also has a substrate 2 on which the light emitting section 1 is disposed, and a second covering member 3 disposed in contact with the periphery of the first covering member 12 on the substrate 2. The second covering member 3 includes a first layer 31 having insulating properties, and a second layer 32 that is disposed on the first layer 31 and contains metal particles. In the example of Fig. 1 and Fig. 2, the light emitting device 100 also has a light-transmitting member 13 disposed on the light emitting element 11.

[0017] The light emitting device 100 can emit light L to the +Z side from the light emitting surface 10 in response to a drive current applied to the light emitting element 11. In the example shown in Fig. 2, a portion of the light L emitted from the light emitting surface 10 is represented by an arrow.

[0018] In the light emitting device 100, by covering the periphery of the light emitting section 1 with the second layer 32, heat generated from the light emitting element 11 in response to light emission is transferred to the second covering member 3 through the first covering member 12, and is easily dissipated to the outside via the metal particles contained in the second covering member 3. As a result, in this embodiment, it is possible to provide a light emitting device 100 with excellent heat dissipation properties. In addition, by disposing the first layer 31 having insulating properties between the second layer 32 containing metal particles and the substrate 2, it is possible to reduce short circuits between the metal particles and the substrate 2. Note that in this embodiment, the form in which the periphery of the light emitting section 1 is covered with the second layer 32 in a plan view includes a form in which the side surface 121 of the light emitting section 1 (i.e., the side surface of the first covering member 12) is discontinuously surrounded by the second layer 32, and a form in which the side surface 121 of the light emitting section 1 is continuously surrounded by the second layer 32. From the viewpoint of heat dissipation, it is preferable that the entire side surface 121 of the light emitting section 1 is in contact with the second layer 32 and is continuously surrounded by the second layer 32.

[0019] The substrate 2 is a member for mounting the light emitting unit 1. The substrate 2 is a plate-like member having a substantially circular shape when viewed from above. However, the shape of the substrate 2 when viewed from above may be substantially elliptical or rectangular, or may be a polygon such as substantially triangular or substantially hexagonal.

[0020] The substrate 2 is preferably made of an insulating material as a base material, and is preferably made of a material that is less permeable to the light L emitted from the light emitting unit 1 and external light. The substrate 2 is also preferably made of a material having a certain strength. Specifically, the substrate 2 can be made of ceramics such as alumina, aluminum nitride, mullite, and silicon nitride, and resins such as phenol resin, epoxy resin, polyimide resin, BT resin (bismaleimide triazine resin), and polyphthalamide as a base material.

[0021] The light emitting unit 1 is mounted on the surface (in other words, the upper surface) of the substrate 2 on the +Z side. The light emitting surface 10 refers to the main light extraction surface of the light emitting unit 1. In the example shown in FIG. 1, the light emitting unit 1 has a substantially rectangular shape when viewed from above. However, the shape of the light emitting unit 1 when viewed from above may be substantially circular or elliptical, or may be substantially triangular, hexagonal, or other polygonal shape. The light emitting unit 1 includes an LED (Light Emitting Diode). The light L emitted by the light emitting unit 1 is preferably white light, but may be monochromatic light. The wavelength and chromaticity of the light L emitted by the light emitting unit 1 can be appropriately selected depending on the use of the light emitting device 100. The light emitting unit 1 may include an LD (Laser Diode).

[0022] 1, the light-emitting surface 10 has a substantially rectangular shape when viewed from above. However, the shape of the light-emitting surface 10 when viewed from above may be substantially circular or elliptical, or may be a polygon such as substantially triangular or substantially hexagonal.

[0023] The light emitting element 11 preferably includes various semiconductors such as III-V group compound semiconductors and II-VI group compound semiconductors. X Al Y Ga 1-X-YIt is preferable to use a nitride-based semiconductor such as InN (0≦X, 0≦Y, X+Y≦1), and InN, AlN, GaN, InGaN, AlGaN, InGaAlN, etc. can also be used. The light-emitting element 11 is, for example, an LED or an LD. From the viewpoints of luminous efficiency and excitation of a wavelength conversion material described later, the emission peak wavelength of the light-emitting element 11 is preferably 400 nm or more and 530 nm or less, more preferably 420 nm or more and 490 nm or less, and even more preferably 450 nm or more and 475 nm or less. As shown in FIG. 3, it is preferable that the light-emitting element 11 is provided with at least a pair of positive and negative electrodes 14 (or at least a pair of an anode electrode and a cathode electrode) on the surface opposite to the light-emitting surface 10 (i.e., the lower surface).

[0024] The light-transmitting member 13 has, for example, a substantially rectangular shape in top view. The light-transmitting member 13 is provided so as to cover the upper surface of the light-emitting element 11. The light-transmitting member 13 can be formed using a light-transmitting resin material or an inorganic material such as ceramics or glass. As the resin material, a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, an epoxy-modified resin, or a phenolic resin can be used. In particular, a silicone resin or a modified resin thereof having excellent light resistance and heat resistance is preferable. Note that the light-transmitting property here preferably means that 60% or more of the light from the light-emitting element 11 is transmitted. In addition, the light-transmitting member 13 can be a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a methylpentene resin, or a polynorbornene resin. Furthermore, the light-transmitting member 13 may contain a light diffusing material or a wavelength conversion material that converts the wavelength of at least a part of the light from the light-emitting element 11 in the above resin. For example, the light-transmitting member 13 may be a resin material, a ceramic, a glass, or the like containing a wavelength conversion material, or a sintered body of a wavelength conversion material. Furthermore, the light-transmitting member 13 may be a multi-layer member in which a resin layer containing a wavelength converting material or a light diffusing material is disposed on the ±Z side surfaces of a molded body of resin, ceramics, glass, or the like.

[0025] The wavelength conversion material contained in the light-transmitting member 13 is, for example, an yttrium-aluminum-garnet phosphor (e.g., (Y,Gd)3(Al,Ga)5O 12:Ce), lutetium-aluminum-garnet-based phosphor (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium-aluminum-garnet-based phosphor (e.g., Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphor (e.g., Ca 10 (PO4)6Cl2:Eu), SAE-based phosphor (e.g., Sr4Al 14 O 25 :Eu), chlorosilicate-based phosphor (e.g., Ca8MgSi4O 16 Cl2:Eu), silicate-based phosphor (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon-based phosphor (e.g., (Si,Al)3(O,N)4:Eu) or α-sialon-based phosphor (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu) and other oxynitride-based phosphors, LSN-based phosphor (e.g., (La,Y)3Si6N 11 :Ce), BSESN-based phosphor (e.g., (Ba,Sr)2Si5N8:Eu), SLA-based phosphor (e.g., SrLiAl3N4:Eu), CASN-based phosphor (e.g., CaAlSiN3:Eu) or SCASN-based phosphor (e.g., (Sr,Ca)AlSiN3:Eu) and other nitride-based phosphors, KSF-based phosphor (e.g., K2SiF6:Mn), KSAF-based phosphor (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1.), or fluoride-based phosphors such as MGF-based phosphor (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively.), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2) can be used. The above wavelength conversion substances are particles. Also, one of these wavelength conversion substances can be used alone, or two or more of these wavelength conversion substances can be used in combination.

[0026] The light emitting device 100 uses a blue light emitting element as the light emitting element 11, and the light transmissive member 13 contains a wavelength conversion material that converts the wavelength of the light emitted from the light emitting element 11 to yellow, thereby enabling the light L, which is white light, to be emitted. Examples of the light diffusing material contained in the light transmissive member 13 include titanium oxide, barium titanate, aluminum oxide, and silicon oxide.

[0027] 2 and 3, the first covering member 12 is disposed on each of the side surface 111 of the light-emitting element 11 and the side surface 131 of the light-transmitting member 13. The first covering member 12 directly or indirectly covers each of the side surface 111 of the light-emitting element 11 and the side surface 131 of the light-transmitting member 13. The upper surface of the light-transmitting member 13 is exposed from the first covering member 12 and constitutes the light-emitting surface 10 of the light-emitting section 1. Note that when the light-emitting section 1 does not have the light-transmitting member 13, the upper surface of the light-emitting element 11 constitutes the light-emitting surface 10.

[0028] The first covering member 12 is preferably made of a material having a high light reflectance in order to improve the light extraction efficiency. The first covering member 12 may be made of a resin material containing a light reflecting substance such as a white pigment. Examples of the light reflecting substance include titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, and silicon oxide. It is preferable to use one of these materials alone or two or more of these materials in combination. In addition, it is preferable to use a resin material containing a thermosetting resin such as an epoxy resin, an epoxy-modified resin, a silicone resin, a silicone-modified resin, or a phenolic resin as a base material as a resin material. The first covering member 12 may be a member having translucency to visible light as necessary. The first covering member 12 may be a member (black member) having light absorbing properties by containing carbon black or the like.

[0029] 1 to 3, the light emitting section 1 including the light emitting element 11 and the first covering member 12 is flip-chip mounted on the substrate 2. As shown in FIG. 3, the substrate 2 has wiring 21 arranged on its surface. The substrate 2 may further have wiring 21 inside. The light emitting element 11 and the substrate 2 are electrically connected by connecting the wiring 21 of the substrate 2 to at least a pair of positive and negative electrodes 14 provided on the lower surface of the light emitting element 11 via a conductive member 22.

[0030] The conductive member 22 may be, for example, a eutectic solder mainly composed of gold and tin, or tin, silver, copper, etc., a conductive paste containing silver, gold, palladium, etc., or a bump containing silver or gold, etc. The light emitting element 11 may be electrically connected to the wiring 21 of the substrate 2 by a wire. The configuration, size, etc. of the wiring 21 of the substrate 2 are set according to the configuration and size of the electrode 14 of the light emitting unit 1.

[0031] The wiring 21 can be made of at least one of copper, iron, nickel, tungsten, chromium, aluminum, silver, gold, titanium, palladium, rhodium, alloys of these, etc. In addition, a layer of silver, platinum, aluminum, rhodium, gold, alloys of these, etc. may be provided on the surface layer of the wiring 21 from the viewpoint of at least one of the wettability and light reflectivity of the conductive member 22.

[0032] In the case of the light emitting unit 1 that is flip-chip mounted, there may be a gap between the substrate 2 and the light emitting unit 1. A first layer 31 provided in the second covering member 3 may be disposed between the first covering member 12 and the substrate 2. When covering the side surface 111 of the light emitting element 11 with the first covering member 12, the first covering member 12 may be in direct contact with the side surface 111, or the first covering member 12 may be in contact with the side surface 111 via a member.

[0033] In FIG. 2, the first layer 31 of the second covering member 3 can be composed of a thermosetting resin such as silicone resin, silicone modified resin, epoxy resin, epoxy modified resin, or phenol resin. The second layer 32 of the second covering member 3 can be composed of a resin containing heat dissipating particles. The above-mentioned thermosetting resins can be used as the resin. The heat dissipating particles can be copper, silver, or resin coated with copper, silver, or the like. At least one of the first layer 31 and the second layer 32 may contain a light reflecting material such as a white pigment. When the first covering member 12 is in contact with the first layer 31 and the second layer 32, the light from the light emitting unit 1 can be reflected at the interface between the first covering member 12 and the first layer 31 and the second layer 32, and can be directed upward from the light emitting unit 1. This improves the front brightness of the light emitting device 100.

[0034] By providing the second covering member 3, the light emitting device 100 can improve the heat dissipation as described above. In addition, when the first covering member 12 and the second covering member 3 contain a light reflective material of a similar color, the outline of the light emitting section 1, for example the outline of the first covering member 12, can be made less noticeable when viewed from above. This can improve the aesthetic appearance of the light emitting device 100. From the viewpoint of improving aesthetics, it is preferable to align the height of the light emitting section 1 and the height of the second covering member 3. In this embodiment, the "height" used to express the positional relationship means the upward distance from the upper surface of the substrate 2 according to the embodiment.

[0035] [Second embodiment] Next, a light emitting device according to a second embodiment will be described. Note that the same names and symbols as those in the already described embodiments indicate the same or similar members or components, and detailed descriptions will be omitted as appropriate. This also applies to the following embodiments.

[0036] <Configuration of the Light Emitting Device According to the Second Embodiment> The configuration of a light emitting device 100a according to the second embodiment will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a schematic top view showing an example of the light emitting device 100a. Fig. 5 is a schematic cross-sectional view showing an example of the light emitting device 100a taken along line VV in Fig. 5.

[0037] As shown in Figures 4 and 5, in the light-emitting device 100a, the substrate 2 has a mounting surface 23 on which the light-emitting section 1 is disposed, and a wall portion 24 connected to the mounting surface 23 and surrounding the light-emitting element 11, and the second layer 32 is disposed in contact with both the side surface 121 of the first covering member 12 and the wall portion 24, which is a main difference from the first embodiment.

[0038] In the example shown in FIG. 5, height t1 represents the height of the light-emitting unit 1, and height t2 represents the height of the wall portion 24. Height t3 represents the height of the portion of the second covering member 3 that contacts the light-emitting unit 1. Height t4 represents the height of the portion of the second covering member 3 that contacts the wall portion 24. In FIG. 5, in detail, height t1 represents the height of the side surface 121 of the light-emitting unit 1, and height t2 represents the height of the inner surface 27 of the wall portion 24. Height t3 represents the height of the portion of the second covering member 3 that contacts the side surface 121 of the light-emitting unit 1. Height t4 represents the height of the portion of the second covering member 3 that contacts the inner surface 27 of the wall portion 24. The surface of the second layer 32 forms a concave surface between the light-emitting unit 1 and the wall portion 24.

[0039] In the light emitting device 100a, one annular wall portion 24 surrounds the light emitting element 11. In other words, the inner surface 27 of the wall portion 24 facing the light emitting element 11 is continuous. Since the substrate 2 has such a wall portion 24, when the second covering member 3 is disposed in contact with the periphery of the first covering member 12 on the substrate 2, the second layer 32 comes into contact with the light emitting unit 1 and the inner surface 27 of the wall portion 24, which makes it easier to conduct heat from the light emitting unit 1 to the wall portion 24 side.

[0040] In the light emitting device 100a, it is preferable that the height t2 of the wall 24 is higher than the height t1 of the light emitting unit 1, and the height t4 of the second covering member 3 at the portion in contact with the wall 24 is higher than the height t3 of the portion in contact with the light emitting unit 1. That is, in the light emitting device 100a, it is preferable that the height t2 of the inner surface 27 of the wall 24 is higher than the height t1 of the side surface 121 of the light emitting unit 1, and the height t4 of the second covering member 3 at the portion in contact with the inner surface 27 of the wall 24 is higher than the height t3 of the portion in contact with the side surface 121 of the light emitting unit 1. With this configuration, the second layer 32 located near the inner surface 27 of the wall 24 has an inclined surface facing the light emitting unit 1 side, so that the light L1 directed toward the wall 24 out of the light L emitted from the light emitting unit 1 is reflected by the surface of the second layer 32, and the reflected light L1 can be collected above the light emitting unit 1. This can increase the light extraction efficiency of the light emitting device 100a.

[0041] 5 shows a state in which light L1 emitted from the light-emitting surface 10 and reflected by the surface of the second layer 32 is collected above the light-emitting unit 1. Note that, in FIG. 5, an example is shown in which the height t4 of the second covering member 3 in contact with the inner surface 27 of the wall portion 24 is approximately the same as the height t2 of the inner surface 27 of the wall portion 24, and the height t3 of the part of the second covering member 3 in contact with the side surface 121 of the light-emitting unit 1 is approximately the same as the height t1 of the side surface 121 of the light-emitting unit 1; however, this is not limiting, and the height t4 of the second covering member 3 in contact with the inner surface 27 of the wall portion 24 may be lower than the height t2 of the inner surface 27 of the wall portion 24, and the height t3 of the part of the second covering member 3 in contact with the side surface 121 of the light-emitting unit 1 may be lower than the height t1 of the side surface 121 of the light-emitting unit 1.

[0042] In the light-emitting device 100a, the surface of the second layer 32 forms a concave surface between the light-emitting unit 1 and the wall portion 24, so that the light L1 reflected on the surface of the second layer 32 can be collected above the light-emitting unit 1 with high efficiency. However, the surface of the second layer 32 is not limited to a concave surface. For example, the surface of the second layer 32 between the light-emitting unit 1 and the wall portion 24 may be an inclined surface with a substantially constant inclination angle, in which the height t4 is higher than the height t3. Even with such an inclined surface, the light-emitting device 100a can collect the light L1 reflected on the surface of the second layer 32 above the light-emitting unit 1, and can increase the light extraction efficiency.

[0043] <Example of Manufacturing Method of Light Emitting Device 100a> 6A to 6C are diagrams showing an example of a method for manufacturing the light emitting device 100a, each diagram showing a cross section of the light emitting device 100a in each of three steps in the method for manufacturing the light emitting device 100a.

[0044] First, as shown in Fig. 6A, a structure is prepared that includes a light-emitting section 1 and a substrate 2 that includes a wall section 24. The wall section 24 and the substrate 2 may be separate members. Fig. 6A shows a state before the second covering member 3 is placed. In the state shown in Fig. 6A, the second covering member 3 is not placed between the light-emitting section 1 and the wall section 24 on the mounting surface 23.

[0045] Next, as shown in FIG. 6B, a first layer 31 of the second covering member 3 is disposed between the light emitting unit 1 and the wall portion 24 on the mounting surface 23 by a potting method. In FIG. 6B, the nozzle Nz1 can discharge droplets Q1 of an insulating resin to dispose the insulating resin between the light emitting unit 1 and the wall portion 24 on the mounting surface 23. At this time, the insulating resin may enter between the lower surface of the light emitting unit 1 and the upper surface of the mounting surface 23. In addition, the nozzle Nz1 can discharge the droplets Q1 while moving in each of the X direction, the Y direction, and the Z direction. Since the substrate 2 has the wall portion 24, the droplets Q1 in a fluid state can be blocked by the wall portion 24. This can prevent the droplets Q1 from flowing out of the substrate 2. After being disposed between the light emitting unit 1 and the wall portion 24 on the mounting surface 23, the insulating resin is heated by a heater or the like to harden, and the first layer 31 is formed. However, the first layer 31 may be formed by using an ultraviolet-curable resin as the insulating resin and curing the resin by irradiating it with ultraviolet light.

[0046] Next, as shown in FIG. 6C, the second layer 32 of the second covering member 3 is disposed between the light-emitting section 1 and the wall section 24 on the first layer 31 by the potting method. In FIG. 6C, the nozzle Nz2 can discharge droplets Q2 of a resin containing metal particles to dispose the resin containing metal particles between the light-emitting section 1 and the wall section 24 on the first layer 31. In addition, the nozzle Nz2 can discharge the droplets Q2 while moving in each of the X direction, the Y direction, and the Z direction. Since the substrate 2 has the wall section 24, the droplets Q2 in a fluid state can be blocked by the wall section 24. This can prevent the droplets Q2 from flowing out of the substrate 2. After the resin containing metal particles is disposed between the light-emitting section 1 and the wall section 24 on the first layer 31, it is cured by heating with a heater or the like to form the second layer 32. However, an ultraviolet-curable resin containing metal particles may be used, and the resin may be cured by irradiating ultraviolet rays to form the second layer 32.

[0047] In disposing the second layer 32, the surface of the second layer 32 can be made concave by utilizing the fact that the resin containing metal particles, in a fluid state, creeps up the side surface 121 of the light-emitting section 1 and the inner surface 27 of the wall section 24 due to surface tension, and the resin shrinks when the resin hardens. Alternatively, resins with different viscosities are prepared for forming the second layer 32, and a resin with a higher viscosity is disposed near the inner surface 27 of the wall section 24 and the side surface 121 of the light-emitting section 1, and a resin with a lower viscosity is disposed away from the inner surface 27 of the wall section 24 and the side surface 121 of the light-emitting section 1 so as to straddle the resin with a higher viscosity disposed near the inner surface 27 of the wall section 24 and the side surface 121 of the light-emitting section 1, respectively, to make the surface of the second layer 32 concave. Furthermore, by disposing low-viscosity resin A across high-viscosity resin disposed near inner surface 27 of wall 24 and low-viscosity resin B disposed near side surface 121 of light-emitting section 1, the surface of second layer 32 can be made into an inclined surface in which height t4 of the portion contacting wall 24 is higher than height t3 of the portion contacting light-emitting section 1. Alternatively, by preparing resins with different viscosities for forming second layer 32, disposing low-viscosity resin on first layer 31, and then disposing high-viscosity resin in a ring shape on low-viscosity resin and near inner surface 27 of wall 24, an inclined surface of second layer 32 can be formed on inner surface 27 side of wall 24.

[0048] In this embodiment, it is preferable to first form the first layer 31, and then form the second layer 32 on the first layer 31. This makes it possible to prevent the resin constituting the first layer 31 and the resin constituting the second layer 32 from mixing with each other, and also makes it possible to easily form a concave or inclined surface on the surface of the second layer 32.

[0049] In this manner, the light emitting device 100a can be manufactured.

[0050] [Third embodiment] Next, a light emitting device according to a third embodiment will be described with reference to Fig. 7. Fig. 7 is a schematic cross-sectional view showing an example of a light emitting device 100b according to a third embodiment. Fig. 7 shows a schematic cross-section of the light emitting device 100b taken along a line corresponding to line II-II in Fig. 1.

[0051] The present embodiment differs from the second embodiment mainly in that it further includes a third coating member 5 having insulating properties and disposed on the second coating member 3. By further including the third coating member 5, the light emitting device 100b can reduce exposure of the second coating member 3 to the outside air. This can reduce oxidation or sulfurization of metal particles such as copper and silver contained in the second coating member 3.

[0052] The third covering member 5 can be formed containing a resin such as silicon oxide, aluminum oxide, phenyl silicone, etc. The third covering member 5 has light-transmitting properties. Note that the light-transmitting properties here preferably allow 60% or more of the light from the light-emitting element 11 to pass through.

[0053] The third covering member 5 can be disposed on the second covering member 3 by using a potting method, a sputtering method, an atomic layer deposition method (ALD: Atomic Layer Deposition), or the like. By using the atomic layer deposition method, the film thickness can be controlled at the atomic layer level, and a flat and dense third covering member 5 can be disposed on the second covering member 3.

[0054] A case where a resin that becomes the third coating member 5 is arranged by the potting method will be described. Here, phenyl silicone resin is taken as an example of the resin that becomes the third coating member 5. First, a resin containing metal particles is arranged on the first layer 31 of the second coating member 3 and cured to form the second layer 32. After the second layer 32 is formed, it is preferable to arrange a phenyl silicone resin on the second layer 32 and cure it to form the third coating member 5. This can prevent the resin containing metal particles before curing from mixing with the phenyl silicone resin. However, after the resin containing metal particles is arranged on the first layer 31 of the second coating member 3, the phenyl silicone resin may be arranged on the resin containing metal particles before curing the resin containing metal particles, and then the resin containing metal particles and the phenyl silicone resin may be heated and cured in parallel to form the second layer 32 and the third coating member 5 in parallel. By forming the second layer 32 and the third coating member 5 in parallel, the manufacturing time of the light emitting device 100b can be shortened and the manufacturing efficiency of the light emitting device 100b can be increased. However, when the resin containing metal particles and the phenyl silicone resin are cured in parallel, it is preferable to make the viscosity of the resin containing metal particles different from that of the phenyl silicone resin, and it is preferable that the viscosity of the resin containing metal particles is higher than that of the phenyl silicone resin. This can reduce the mixing of the resin constituting the second layer 32 and the resin constituting the third coating member 5 before curing.

[0055] [Fourth embodiment] Next, the configuration of the light emitting device according to the fourth embodiment will be described with reference to Fig. 8. Fig. 8 is a schematic cross-sectional view showing an example of the light emitting device 100c according to the fourth embodiment. Fig. 8 shows a schematic cross-section of the light emitting device 100c taken along a line corresponding to line II-II in Fig. 1.

[0056] In this embodiment, the main difference from the second embodiment is that the substrate 2 has a laminated structure of a copper-containing layer 25 and a resin-containing layer 26. In the light emitting device 100c, the substrate 2 has the copper-containing layer 25, which has high heat dissipation properties, thereby increasing the heat dissipation efficiency of the substrate 2 and improving the heat dissipation of the light emitting device 100c.

[0057] 9A to 9D are diagrams showing a method for manufacturing the substrate 2 included in the light emitting device 100c, and each diagram shows a cross section of the substrate 2 in each of four steps in the method for manufacturing the substrate 2 included in the light emitting device 100c.

[0058] 9A, a wiring board 241 is prepared, which has a laminated structure of a copper-containing layer 25 and a resin-containing layer 26 and has wiring of a predetermined pattern formed thereon. The wiring of the predetermined pattern is provided on the surface of the wiring board 241. The wiring of the predetermined pattern may also be provided inside the wiring board 241.

[0059] Next, as shown in Fig. 9B, a plurality of wiring boards 241 are stacked on the prepared wiring board 241. The number of stacked wiring boards 241 is not limited to two as shown in Fig. 9B, and may be three or more. The height of the wall portion 24 is determined by the number of stacked wiring boards 241, etc. Note that the wiring board 241 may be a single board rather than stacked.

[0060] 9C, a through hole 242 is formed by drilling or the like in a structure obtained by stacking a plurality of wiring boards 241, thereby obtaining a wall portion 24 having an inner surface 27. The through hole 242 has a substantially circular shape when viewed from above. In this case, the wall portion 24 has a substantially circular annular shape when viewed from above, and the inner surface 27 also has a circular annular shape. Note that the shapes of the through hole 242, the wall portion 24, and the inner surface 27 when viewed from above are not limited to a substantially circular shape, and may be an ellipse, a polygon, or the like.

[0061] Next, as shown in FIG. 9D, the wall portion 24 obtained by the process shown in FIG. 9C is placed at a predetermined position on the mounting surface 23 of the substrate 2 where the wall portion 24 is not provided, and is adhered to the mounting surface 23 by an adhesive material or the like.

[0062] In this manner, the substrate 2 included in the light emitting device 100c can be manufactured.

[0063] [Fifth embodiment] Next, a light emitting device according to a fifth embodiment will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a schematic top view showing an example of a light emitting device 100d according to the fifth embodiment. Fig. 11 is a schematic cross-sectional view taken along line XI-XI in Fig. 10.

[0064] This embodiment differs from the second embodiment in that it further includes a lens 4 that transmits light L from the light emitting element 11. In this embodiment, the light emitting device 100d having high light extraction efficiency can be provided by irradiating light L from the light emitting element 11 through the lens 4.

[0065] 11, by making the height t4 of the second covering member 3 at the portion in contact with the wall portion 24 greater than the height t3 of the portion in contact with the light-emitting portion 1, it is possible to allow the light L1 reflected on the surface of the second layer 32, out of the light L from the light-emitting element 11, to enter the lens 4. This makes it possible to increase the light extraction efficiency of the light-emitting device 100d.

[0066] In the example shown in FIG. 11, the lens 4 includes a Fresnel lens. The lens 4 has a Fresnel lens on a light incident surface facing the light emitting unit 1. After the second layer 32 shown in FIG. 6C is formed, the lens 4 is placed on the +Z side surface of the wall portion 24 and adhered to the substrate 2 by an adhesive member 41. The adhesive member 41 may be a double-sided tape, a resin, or the like. The lens 4 is not limited to a Fresnel lens, and may include a plano-convex lens, a plano-concave lens, a biconvex lens, a biconcave lens, a meniscus lens, a diffractive lens, a metalens, or the like. The configuration of the portion where the lens 4 is adhered to the wall portion 24 can be appropriately changed depending on the use of the light emitting device 100d, etc.

[0067] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0068] For example, any two or more of the above-described first to fifth embodiments may be combined.

[0069] The ordinal numbers, quantities, and other numbers used in the description of the embodiments are all provided as examples to specifically explain the technology of the present disclosure, and the present disclosure is not limited to the illustrated numbers. Furthermore, the connection relationships between the components are provided as examples to specifically explain the technology of the present disclosure, and do not limit the connection relationships that realize the functions of the present disclosure.

[0070] The light emitting device according to the embodiment of the present disclosure has excellent heat dissipation properties and can be suitably used as a flash light source or a light source for a headlight with variable light distribution as a vehicle lamp. In addition, the light emitting device according to the embodiment of the present disclosure can be used as a backlight light source for a liquid crystal display, various lighting fixtures, a large display, various display devices such as advertisements and destination guides, and further, an image reading device in a digital video camera, a facsimile, a copier, a scanner, a projector device, etc. However, the light emitting device according to the present disclosure is not limited to these applications.

[0071] Aspects of the present disclosure are, for example, as follows. <Item 1> A light emitting device comprising: a light emitting section including a light emitting element; and a first covering member having insulating properties and disposed on a side surface of the light emitting element; a substrate on which the light emitting section is disposed; and a second covering member disposed on the substrate in contact with a periphery of the first covering member, the second covering member including a first layer having insulating properties, and a second layer containing metal particles and disposed on the first layer. <Item 2> The light-emitting device described in <Item 1>, wherein the substrate has a mounting surface on which the light-emitting portion is arranged and a wall portion connected to the mounting surface and surrounding the light-emitting element, and the second layer is arranged in contact with both a side surface of the first covering member and the wall portion. <Item 3> The light-emitting device described in <Item 2>, wherein the height of the wall portion is greater than the height of the light-emitting portion, and the height of the portion of the second covering member that contacts the wall portion is greater than the height of the portion of the second covering member that contacts the light-emitting portion. <Item 4> The light emitting device according to any one of <Item 1> to <Item 3>, further comprising a third covering member disposed on the second covering member and having insulating properties. <Item 5> The light emitting device according to any one of <Item 1> to <Item 4>, wherein the substrate has a laminated structure of a layer containing copper and a layer containing resin. <Item 6> The light emitting device according to any one of <Item 1> to <Item 5>, further comprising a lens that transmits light from the light emitting element. [Explanation of symbols]

[0072] 1 Light emitting unit 10 Light-emitting surface 11 Light emitting element 111 Side 12 First covering member 121 Side 13 Translucent material 131 Side 14 electrodes 2. Board 21 Wiring 22 Conductive materials 23 Mounting surface 24 Wall 241 Wiring Board 242 Through hole 25 Copper-containing layer 26 Resin-containing layer 27 Inner surface 3 Second covering member 31 1st layer 32 2nd layer 4 Lenses 41 Adhesive materials 5. Third covering member 100, 100a, 100b, 100c, 100d Light-emitting device L light L1 reflected light Nz1, Nz2 nozzles Q1 Insulating resin droplet Q2 Resin droplets containing metal particles t1 Height of the light emitting part t2 wall height t3 Height of the part of the second covering member that comes into contact with the light-emitting part t4 Height of the part of the second covering member that comes into contact with the wall

Claims

1. A light emitting unit including a light emitting element and a first covering member having insulating properties and disposed on a side surface of the light emitting element; A substrate on which the light emitting portion is disposed; a second covering member disposed on the substrate in contact with a periphery of the first covering member, The second covering member is A first layer having insulating properties; a second layer disposed over the first layer, the second layer containing metal particles.

2. The substrate is a mounting surface on which the light emitting portion is disposed, and a wall portion connected to the mounting surface and surrounding the light emitting element; The light emitting device according to claim 1 , wherein the second layer is disposed in contact with both a side surface of the first covering member and the wall portion.

3. The height of the wall portion is greater than the height of the light-emitting portion, The light emitting device according to claim 2 , wherein a height of the second covering member at a portion in contact with the wall portion is greater than a height of a portion in contact with the light emitting portion.

4. The light emitting device according to claim 1 , further comprising a third covering member disposed on the second covering member and having insulating properties.

5. The light emitting device according to claim 1 , wherein the substrate has a laminated structure of a layer containing copper and a layer containing resin.

6. The light emitting device according to claim 1 , further comprising a lens that transmits light from the light emitting element.

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