Manufacturing method of light-emitting device

Abstract

To provide a method for manufacturing a light-emitting device that has high reflectance of a reflection member surrounding light-emitting elements, and can suppress occurrence of stray light.SOLUTION: A manufacturing method of a light-emitting device 100 has: a step of preparing an intermediate having a substrate 10 having a first face and one or more of light-emitting elements 1 arranged on the first face of the substrate 10, and a mixture produced by mixing first resin 51 and a plurality of first hollow particles 52; a step of applying the mixture to the first face of the substrate 10 so as to surround the light-emitting element 1; and a step of curing the mixture to form a first reflection member 41. In the preparing step, the content of the plurality of first hollow particles is 20 parts or more and 50 parts or less for the mass 100 of the first resin, irregularities are formed on the surface of the first reflection member by the first hollow particles after the step of forming the first reflection member, and the surface roughness Ra of the first reflection member is 0.10 μm or more and 3.0 μm or less, and the reflectance is 40% or more.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Various light-emitting devices using light-emitting elements have been developed. For example, Patent Document 1 discloses a light-emitting device in which a frame made of light-reflective resin is formed around the light-emitting element and the inside of the frame is filled with a low-viscosity light-reflective resin. Furthermore, for example, Patent Document 2 discloses a light-emitting device in which the surface of a sealing member that seals the light-emitting element has irregularities formed due to particles of the filler. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5648422 [Patent Document 2] Patent No. 5953736 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a light emitting device in which the reflecting member surrounding the periphery of a light emitting element has high reflectivity and is capable of suppressing the generation of stray light, and a method for manufacturing the same. [Means for solving the problem]

[0005] A light emitting device according to an embodiment of the present disclosure comprises a substrate having a first surface, one or more light emitting elements arranged on the first surface of the substrate, and a first reflective member surrounding the light emitting elements and arranged on the first surface of the substrate, wherein the first reflective member comprises a first resin and a plurality of first hollow particles contained in the first resin, the first hollow particles forming unevenness on the surface of the first reflective member, the surface roughness Ra of the first reflective member being 0.10 μm or more and 3.0 μm or less, and the reflectivity of the first reflective member being 40% or more.

[0006] A method for manufacturing a light emitting device according to an embodiment of the present disclosure includes the steps of preparing an intermediate body having a substrate with a first surface and one or more light emitting elements arranged on the first surface of the substrate, and a mixture of a first resin and a plurality of first hollow particles; applying the mixture to the first surface of the substrate so as to surround the light emitting elements; and curing the mixture to form a first reflecting member, wherein after the step of forming the first reflecting member, the first hollow particles form irregularities on the surface of the first reflecting member, the surface roughness Ra of the first reflecting member is 0.10 μm or more and 3.0 μm or less, and the reflectivity of the first reflecting member is 40% or more. [Effects of the Invention]

[0007] According to the embodiments of the present disclosure, it is possible to realize a light emitting device and a manufacturing method thereof in which the reflectance of the reflective member surrounding the periphery of the light emitting element is high and the generation of stray light can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically illustrating a light emitting device according to an embodiment. [Figure 2] 1 is a plan view schematically showing a light emitting device according to an embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 3 is a plan view schematically showing a first reflecting member, a second reflecting member, and wires in the light emitting device according to the embodiment. FIG. [Figure 8] FIG. 3 is an enlarged cross-sectional view schematically showing a part of a first reflecting member of the light emitting device according to the embodiment. [Figure 9]1 is a graph showing the relationship between surface roughness Ra and matte finish. [Figure 10] 5 is a schematic cross-sectional view for explaining a method for measuring the angle formed between a first surface of the substrate and a first reflecting member. FIG. [Figure 11] 1 is a flowchart illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12A] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12B] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12C] 1A to 1C are enlarged plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12D] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12E] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12F] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12G] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12H] 1A to 1C are plan views schematically illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 13A] 10 is an enlarged cross-sectional view schematically showing a part of a first reflecting member in a first modified example of the embodiment. FIG. [Figure 13B] 10 is an enlarged cross-sectional view schematically showing a part of a first reflecting member in a second modified example of the embodiment. FIG. [Figure 13C] FIG. 11 is an enlarged cross-sectional view schematically showing a part of a first reflecting member in a third modified example of the embodiment. [Figure 13D] 10 is an enlarged cross-sectional view schematically showing a part of a first reflecting member in a fourth modified example of the embodiment. FIG. [Figure 14] FIG. 10 is a cross-sectional view schematically showing a fifth modified example of the embodiment. [Figure 15] FIG. 10 is a partial cross-sectional view of a fifth modified example of the embodiment. [Figure 16]FIG. 13 is an enlarged cross-sectional view schematically showing a part of a sealing member in a fifth modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] <<Embodiment>> Light-emitting devices and manufacturing methods thereof according to embodiments will be described below with reference to the drawings. Note that the size and positional relationships of components shown in each drawing may be exaggerated for clarity. Furthermore, the dimensions and positions of components may not strictly match between plan views and corresponding cross-sectional views. To avoid overly complex drawings, some elements may be omitted, or end views showing only the cut surface may be used as cross-sectional views. Furthermore, in the following description, up, down, left, right, front, and back are relative and do not indicate absolute directions. Furthermore, identical names and symbols generally refer to identical or similar components, and detailed descriptions may be omitted as appropriate. Furthermore, in the embodiments, "coating" and "covering" are not limited to direct contact, but also include indirect covering, for example, via another component. In this specification, a planar view refers to observation from the light extraction surface side of the light-emitting device.

[0010] [Light-emitting device] FIG. 1 is a perspective view schematically showing a light emitting device according to an embodiment. FIG. 2 is a plan view schematically showing a light emitting device according to an embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 2. FIG. 7 is a plan view schematically showing a first reflecting member, a second reflecting member, and a wire in a light emitting device according to an embodiment. FIG. 8 is an enlarged cross-sectional view schematically showing a part of the first reflecting member of a light emitting device according to an embodiment. FIG. 8 schematically shows the portion indicated by symbol A in FIG. 5. FIG. 9 is a graph showing the relationship between surface roughness Ra and matte finish. FIG. 10 is a schematic cross-sectional view for explaining a method for measuring the angle between the first surface of the substrate and the first reflecting member. In the drawings, the first wire 31, the second wire 32, the third wire 33, etc. arranged inside the covering member 40 may not be visible, but for the sake of convenience, the first wire 31, etc. are shown in a form that allows them to be seen.

[0011] The light emitting device 100 includes a substrate 10 having a first surface 10a, one or more light emitting elements 1 arranged on the first surface 10a of the substrate 10, and a first reflecting member 41 arranged on the first surface 10a of the substrate 10 and surrounding the light emitting elements 1. The first reflecting member 41 includes a first resin 51 and a plurality of first hollow particles 52 contained in the first resin 51, and the first hollow particles 52 form unevenness on the surface of the first reflecting member 41, the surface roughness Ra of the first reflecting member 41 being 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflecting member 41 being 40% or more.

[0012] The light emitting device 100 mainly comprises a plurality of light emitting elements 1, a first substrate 10 on which the plurality of light emitting elements 1 are mounted, a second substrate 20 on which the first substrate 10 is mounted, a first wire 31 and a second wire 32 which are wires 130 that electrically connect the first substrate 10 and the second substrate 20, a covering member 40 that covers the wire 130, a first reflecting member 41 that is arranged on the first substrate 10 and in contact with the covering member 40, a second reflecting member 42 that is arranged on the second substrate and in contact with the covering member 40, a third reflecting member 7 that covers the side surfaces of the light emitting elements 1 on the first substrate 10, and a translucent member 5 that covers the top surface of the light emitting elements 1. Each component will be described below.

[0013] (First board) The first substrate 10 includes a flat support member and wiring arranged on the upper surface of the support member. The first substrate 10 has an element mounting region 13 on its upper first surface 10a where multiple light-emitting elements 1 are mounted, and wiring is arranged in the element mounting region 13 to form a predetermined electrical circuit. The first substrate 10 has multiple first terminals 110 as wiring arranged on the upper surface outside the element mounting region 13, and the first terminals 110 are electrically connected to the wiring arranged in the element mounting region 13. The first substrate 10 is a semiconductor substrate made of, for example, silicon, and an area on the upper surface where no wiring is arranged is covered with an insulating film. Wiring may also be arranged inside or on the lower surface of the support member. For example, the first substrate 10 can be an integrated circuit (IC) substrate on which circuits for driving and controlling the multiple light-emitting elements 1 are integrated. In the element mounting region 13, a plurality of light-emitting elements 1 are mounted in a matrix. However, the plurality of light-emitting elements 1 may be arranged not only in a matrix of two rows and / or two or more columns, but also in only one row or only one column. As an example, the element mounting region 13 in a plan view may be a rectangular region. In this case, the element mounting region 13 is rectangular, and the first terminals 110 are arranged in rows along opposing long sides of the rectangle so as to sandwich the element mounting region 13.

[0014] The first terminals 110 include a plurality of first external connection terminals 11 arranged in a row along one long side of the rectangular element mounting region 13 outside the element mounting region 13, and a plurality of second external connection terminals 12 arranged in a row along the other long side opposite to the one long side. The first external connection terminal 11 is a terminal to which one end of a first wire 31 is connected. The second external connection terminal 12 is a terminal to which one end of a second wire 32 is connected. Here, as an example, the plurality of first external connection terminals 11 and the plurality of second external connection terminals 12 are each substantially rectangular and are arranged in a row along the long sides of the element mounting region 13 at a distance from each other.

[0015] Here, as an example, the first substrate 10 includes a plurality of first drive terminals 15 that handle drive signals for turning on or off the light-emitting elements 1. The first drive terminals 15 can be arranged, for example, alternately with the first external connection terminals 11 and in the same row. A third wire 33, which will be described later, is connected to the first drive terminals 15. The plurality of light-emitting elements 1 are placed in a matrix on the first substrate 10 and are electrically connected to one of the first terminals 110 (i.e., the first external connection terminal 11 and the second external connection terminal 12). The plurality of light-emitting elements 1 may be grouped into a predetermined number and connected in series or parallel to the first terminals 110. The wiring can be formed using, for example, metals such as Cu, Ag, Au, Al, Pt, Ti, W, Pd, Fe, Ni, etc., or alloys thereof, etc. Such wiring can be formed by electroplating, electroless plating, vapor deposition, sputtering, etc.

[0016] (Second board) The second substrate 20 includes a flat base material and wiring arranged on at least the upper surface of the base material. The second substrate 20 has a substrate mounting area 23 on its upper surface for mounting the first substrate 10, and further includes second terminals 120 on its upper surface outside the substrate mounting area 23. The substrate mounting area 23 is an area on which the first substrate 10 is mounted via a bonding member. The substrate mounting area 23 is set as an area having an area equivalent to the shape of the first substrate 10 in a plan view. If the first substrate 10 is rectangular in a plan view, the substrate mounting area 23 can also be rectangular. Here, the second terminals 120 include a first wire connecting terminal 21 connected to the first external connection terminal 11 via a wire, and a second wire connecting terminal 22 connected to the second external connection terminal 12 via a wire, and the first wire connecting terminal 21 and the second wire connecting terminal 22 are arranged on the second substrate 20 with the substrate mounting area 23 sandwiched therebetween.

[0017] A plurality of first wire connecting terminals 21 are arranged in a row outside the substrate mounting area 23 along one long side of the rectangular substrate mounting area 23. The first wire connecting terminals 21 are terminals to which one end of a first wire 31, the other end of which is connected to the first external connection terminal 11, is connected. A plurality of second wire connecting terminals 22 are arranged in a row outside the substrate mounting area 23 along the other long side of the rectangular substrate mounting area 23 (i.e., the side located on the opposite side of the substrate mounting area 23 from the one long side mentioned above). The second wire connecting terminal 22 is a terminal to which one end of a second wire 32, one end of which is connected to the second external connection terminal 12, is connected. Here, as an example, the first wire connecting terminals 21 and the second wire connecting terminals 22 are each approximately rectangular, and are arranged spaced apart from each other and aligned in a row along the long side of the substrate mounting area 23.

[0018] The second terminal 120 can be formed, for example, using the same material and method as those for the wiring of the first substrate 10 already described. Here, as an example, the second substrate 20 has, on its upper surface, a plurality of second drive terminals 16 for driving that handle drive signals for turning on or off the light-emitting elements 1. The second drive terminals 16 are arranged, for example, on the upper surface more inward than the first wire connection terminals 21 (i.e., on the substrate placement area 23 side). A third wire 33, which will be described later, is connected to the second drive terminals 16.

[0019] The substrate is preferably made of a material with high heat dissipation properties, and more preferably a material with high light-blocking properties and substrate strength. Specific examples include ceramics such as alumina, aluminum nitride, and mullite; resins such as phenolic resin, epoxy resin, polyimide resin, bismaleimide triazine resin, and polyphthalamide; and composites composed of resin and metal or ceramic. The substrate may be flat, or may have a cavity on its upper surface. In this case, the bottom of the cavity serves as the substrate mounting area for the second substrate 20, and the first substrate 10 can be mounted within the cavity. The second substrate 20 may have wiring on the surface of the substrate mounting area 23 for mounting the first substrate 10. The first substrate 10 and the second substrate 20 can be bonded via a bonding material such as an Ag sintered body, solder, or adhesive resin.

[0020] (wire) Examples of the wire 130 include conductive wires made of metals such as gold, copper, platinum, and aluminum and / or alloys containing at least these metals. Gold, which has excellent thermal resistance, is particularly preferable. The wire diameter may be, for example, 15 μm or more and 50 μm or less. The wire 130 includes a first wire 31 and a second wire 32 connected to the first terminal 110 and the second terminal 120, respectively, and a third wire 33 that handles a drive signal for turning on or off the light-emitting element 1. The third wire 33 is connected to a first drive terminal 15 disposed on the first substrate 10 and a second drive terminal 16 disposed on the second substrate 20. The first wire 31, the second wire 32, and the third wire 33 may be made of the same material, differing only in length. The wires 130 can be arranged to straddle the long sides of the first substrate 10, which is substantially rectangular in plan view, and to be, for example, substantially perpendicular to the long sides.

[0021] (light-emitting element) The light-emitting element 1 has, for example, a substantially rectangular shape in plan view and includes a semiconductor laminate and positive and negative electrodes disposed on the surface of the semiconductor laminate. The light-emitting element 1 has positive and negative electrodes on the same side and is flip-chip mounted on the first substrate 10 with the electrode-equipped surface as the underside. In this case, the upper surface opposite the electrode-equipped surface serves as the main light extraction surface of the light-emitting element 1. In the light-emitting device 100, the light-emitting elements 1 are mounted on the first substrate 10 in a matrix arrangement with a predetermined spacing between them. The size and number of light-emitting elements 1 to be used can be appropriately selected depending on the desired configuration of the light-emitting device. In particular, it is preferable to mount a larger number of smaller light-emitting elements 1 at a higher density. This allows the illumination range to be controlled with a larger number of divisions, making it suitable for use as a light source for a high-resolution lighting system. For example, a configuration may be used in which 1,000 to 20,000 light-emitting elements 1 each having a rectangular shape in plan view and each measuring 40 to 100 μm on a side are mounted in a matrix arrangement to form a rectangle as a whole.

[0022] The light emitting element 1 can be selected from those with any wavelength. For example, blue and green light emitting elements 1 can be made of ZnSe or nitride semiconductors (In X Al Y Ga 1-X-Y N, 0≦X, 0≦Y, X+Y≦1), or GaP can be selected. As the red light emitting element 1, semiconductors represented by GaAlAs and AlInGaP can be suitably used. Furthermore, semiconductor light emitting elements made of materials other than these can also be used. The composition and emitted color of the light emitting element 1 to be used can be appropriately selected depending on the purpose.

[0023] (jointing material) As shown in FIG. 6, the light-emitting element 1 is bonded to wiring arranged in the element mounting region 13 of the first substrate 10 by a conductive bonding material. When flip-chip mounting the light-emitting element 1 on the first substrate 10, bumps made of a metal material such as Au, Ag, Cu, or Al can be used as the bonding material. Alternatively, solder such as an AuSn-based alloy or Sn-based lead-free solder can be used as the bonding material. In this case, the light-emitting element 1 can be bonded to the first substrate 10 by a reflow method. Alternatively, a conductive adhesive made of resin containing conductive particles can be used as the bonding material. The light-emitting element 1 and the first substrate 10 may be bonded by a plating method. An example of the material is copper. Furthermore, the light emitting element 1 and the first substrate 10 may be bonded together by directly bonding the electrodes of the light emitting element 1 to the wiring of the first substrate 10 without using a bonding member.

[0024] (Third reflecting member) As shown in FIG. 6 , the third reflecting member 7 is a member that covers the upper surface of the first substrate 10 and the side surface of the light-emitting element 1. The upper surface of the light-emitting element 1 is exposed from the third reflecting member 7. The third reflecting member 7 may cover the area between the lower surface of the light-emitting element 1 and the first substrate 10. The third reflecting member 7 reflects light emitted from the side surface of the light-emitting element 1 and allows the light to exit from the upper surface of the light-transmitting member 5, which is the light-emitting surface of the light-emitting device 100. This improves the light extraction efficiency of the light-emitting device 100. Furthermore, when the light-emitting elements 1 are individually lit, the boundary between the light-emitting area and the non-light-emitting area can be clearly defined. This improves the contrast ratio between the light-emitting area and the non-light-emitting area. The third reflecting member 7 may be disposed apart from the first reflecting member 41 or in contact with the first reflecting member 41.

[0025] The third reflecting member 7 is preferably made of a soft resin with relatively low elasticity and excellent shape conformability. A resin material with good insulating properties, such as a thermosetting resin such as an epoxy resin or a silicone resin, is preferably used as the material for the third reflecting member 7. The third reflecting member 7 is preferably made of a white resin containing particles of a light-reflecting material in a base resin. Suitable examples of the light-reflecting material include titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass filler. The third reflecting member 7 may also contain a light-absorbing material such as carbon black or graphite.

[0026] (Translucent member) The light-transmitting member 5 is light-transmitting and covers the upper surfaces of the plurality of light-emitting elements 1. The light-transmitting member 5 collectively covers the upper surfaces of the plurality of light-emitting elements 1 and the upper surface of the third reflecting member 7. The upper surface of the light-transmitting member 5 forms the light-emitting surface of the light-emitting device 100. The light-transmitting member 5 may contain a wavelength conversion member. Here, as an example, the light-transmitting member 5 contains a wavelength conversion member, and converts the wavelength of at least a portion of the light emitted from the light-emitting element 1 and emits it to the outside. An example of the wavelength conversion member is a phosphor. The light-transmitting member 5 has a substantially rectangular shape in a plan view, and is disposed so as to cover the upper surfaces of the plurality of light-emitting elements 1.

[0027] The light-transmitting member 5 may be processed into a sheet or plate shape and placed on the light-emitting element 1, or may be applied in the form of a layer on the light-emitting element 1 by spraying or the like. Alternatively, it may be formed by injection molding using a metal mold or the like, transfer molding, compression molding or the like. Examples of the light-transmitting member containing a wavelength conversion member include a sintered body of a phosphor, and a base material such as resin, glass, or other inorganic material containing a phosphor powder. The base material may be a light-transmitting material such as epoxy resin, silicone resin, a mixture of these, or glass. The thickness of the light-transmitting member 5 may be, for example, approximately 20 μm to 100 μm. The light-transmitting member 5 is formed to a size sufficient to cover the entire upper surfaces of the plurality of light-emitting elements 1. The light-transmitting member 5 extends to a position where it abuts against a first reflecting member 41, which will be described later.

[0028] The phosphor is an yttrium-aluminum-garnet phosphor (e.g., Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), nitride-based phosphors such as KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si,Al)F6:Mn), or MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)3), or quantum dot phosphors (e.g., CdSe, InP, AgInS2, or AgInSe2), etc., can be used.

[0029] (Covering material) The covering member 40 is a light-blocking resin that covers the wires 130 (specifically, the first wire 31 and the second wire 32) outside the element mounting region 13. As an example, the covering member 40 is arranged in a frame shape in a plan view so as to cover the first wire 31 and the second wire 32 and surround the element mounting region 13. The covering member 40 is arranged so as to be in contact with a first reflecting member 41, which will be described later. The covering member 40 also covers the third wire 33. The covering member 40 is arranged at a distance from the light-transmitting member 5.

[0030] Furthermore, the covering member 40, which is arranged in a frame shape, has a width greater on the long side of the rectangle of the first substrate 10, which is generally rectangular in plan view, than on the short side. Furthermore, the covering member 40 is arranged so that its height (i.e., the distance from the upper surface of the second substrate 20 to the upper surface of the covering member 40) is greatest directly above the top 130a of the wire 130 (here, the loop top of the wire). In other words, the covering member 40 is arranged so that the top 40a of the covering member 40 overlaps the top 130a of the wire 130. The top 40a of the covering member 40 is arranged so as to be located higher than the top 41a of the first reflecting member 41, which will be described later.

[0031] Examples of the light-blocking covering member 40 include resins containing a filler with light-blocking properties. Examples of the base resin that can be used include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, and acrylic resin. Examples of the light-blocking filler include light-absorbing substances such as pigments, carbon black, and graphite, and light-reflecting substances similar to the light-reflecting substances contained in the third reflecting member described above. Specific examples include white resins with excellent light reflectivity, black resins with excellent light absorption, and gray resins with both light reflectivity and light absorption. Furthermore, the covering member 40 may be formed by laminating multiple layers of these resins. In particular, in consideration of deterioration of the resin due to light absorption, it is preferable that the covering member 40 uses a white resin having light reflectivity at least on the outermost surface.

[0032] (First reflecting member, second reflecting member) The light emitting device 100 has a first reflecting member 41 that is disposed along the element mounting region 13 on the first substrate 10 between the element mounting region 13 and the first terminal 110 and that contacts the covering member 40. Furthermore, the light emitting device 100 has a second reflecting member 42 that is disposed on the upper surface of the second substrate 20, outside the second terminal 120, and that contacts the covering member 40. In other words, the covering member 40 is disposed between the first reflecting member 41 and the second reflecting member 42, spanning from the upper surface of the first substrate 10 to the upper surface of the second substrate 20. The covering member 40 is disposed between a first reflecting member 41 disposed on the first substrate 10 so as to surround the element mounting region 13, and a second reflecting member 42 disposed on the second substrate 20 so as to surround the substrate mounting region 23. Such an arrangement of the covering member 40 can be formed by supplying uncured resin that constitutes the covering member 40 into a frame surrounded by the first reflecting member 41 and the second reflecting member 42. In other words, the first reflecting member 41 and the second reflecting member 42 can be used as a dam to block the flow of uncured resin when the covering member 40 is supplied.

[0033] The first reflecting member 41 and the second reflecting member 42 can be made to a predetermined height by providing a plurality of layers of uncured resin in the height direction. For example, the first reflecting member 41 and the second reflecting member 42 are made to have a predetermined height by disposing resin adjusted to a predetermined viscosity from a nozzle in one layer on the substrate and repeating this process.

[0034] The height of the first reflecting member 41 from the top surface of the first substrate 10 may be the same as or different from the height of the second reflecting member 42 from the top surface of the second substrate 20. If they are different, it is preferable to make the second reflecting member 42 higher than the first reflecting member 41. In this case, the difference between the height from the top surface of the second substrate 20 to the apex of the first reflecting member 41 and the height from the top surface of the second substrate 20 to the apex of the second reflecting member 42 can be made smaller than the thickness of the first substrate 10 (i.e., the distance from the top surface to the bottom surface of the first substrate 10). This makes it possible to prevent the uncured coating member 40 from spilling out of the second reflecting member 42 when the coating member 40 is disposed between the first reflecting member 41 and the second reflecting member 42.

[0035] The first reflecting member 41 is arranged in the shape of a rectangular frame in plan view that surrounds the element mounting region 13. The covering member 40 is arranged so as to be in contact with the top of the first reflecting member 41, for example. The first reflecting member 41 is arranged in a rectangular frame shape in a plan view on the first substrate 10 along the outer periphery of the element mounting region 13. The first reflecting member 41 is arranged between the longitudinal sides of the element mounting region 13 and the plurality of first terminals 110 at a position along the longitudinal direction of the element mounting region 13, and is arranged on the first substrate 10 between the element mounting region 13 and the outer edge of the first substrate 10 at a position along the lateral direction of the element mounting region 13.

[0036] The first reflecting member 41 preferably has an inclined surface that slopes from the first substrate 10 side toward the top of the first reflecting member 41. The inclined surface is preferably a curved surface that is convex outward. Specifically, the first reflecting member 41 is preferably substantially semicircular or substantially semielliptical in a cross section perpendicular to the first surface 10a of the first substrate 10. This allows the surface of the covering member 40 that contacts the first reflecting member 41 to be a curved surface that is convex toward the covering member 40 side. By having the covering member 40 have such a shape, light that is emitted from the light-transmitting member 5, passes through the first reflecting member 41, and heads toward the covering member 40 can be reflected toward the first substrate 10. This prevents unintended leakage light and stray light from traveling upward (toward the light extraction side), thereby providing a light-emitting device with reduced light scattering.

[0037] In this embodiment, the term "approximately semicircle" does not necessarily mean a semicircle in the strict sense, such as a circle divided into two equal parts, but includes shapes that are visually perceived as being close to a semicircle. For example, it may be a semicircle that is distorted or deformed within the tolerance or error range. Specifically, it includes a semicircle that is a circle with a tolerance or error value of 5% or less of the diameter. If the tolerance or error value exceeds 5% of the diameter, it is considered to be an approximately ellipse. Note that the semicircle does not have to be divided into two equal parts. Furthermore, the term "approximately semi-ellipse" in this embodiment does not necessarily mean a shape obtained by bisecting a strict ellipse, which is a locus of points whose sum of distances from two fixed points on a plane is constant, but also includes shapes that are visually perceived as being close to a semi-ellipse. For example, it may be a shape obtained by bisecting an oval shape obtained by extending a circle in one direction, an oval shape, or the shape of an athletics track. In other words, it may be a shape obtained by bisecting an approximately ellipse. The term "approximately ellipse" also includes a shape enclosed by a pair of straight or curved lines extending along the longitudinal or lateral direction and a pair of curved lines connected to the pair of straight or curved lines and curved outward in a convex manner. For example, a shape obtained by connecting the ends of two opposing parallel sides or two opposing curved sides on the same side with arcs of the same diameter (e.g., semicircular arcs) may be mentioned. Note that a semi-ellipse does not have to be bisected strictly.

[0038] As shown in FIG. 8 , the first reflecting member 41 includes a first resin 51 and a plurality of first hollow particles 52 contained in the first resin 51. That is, the first reflecting member 41 contains a plurality of first hollow particles 52. The first hollow particles 52 form irregularities on the surface of the first reflecting member 41. Specifically, the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less. If the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more, light from the light-emitting element 1 that strikes the first reflecting member 41, as well as reflected light from within the device and external light, are diffused, thereby suppressing the generation of stray light. This allows for a desired illumination pattern to be obtained. On the other hand, if the surface roughness Ra of the first reflecting member 41 is 3.0 μm or less, it is easier to form irregularities on the surface of the first reflecting member 41.

[0039] The surface roughness Ra of the first reflecting member 41 is preferably 0.50 μm or more and 2.0 μm or less. If the surface roughness Ra of the first reflecting member 41 is 0.50 μm or more, the generation of stray light is further suppressed. On the other hand, if the surface roughness Ra of the first reflecting member 41 is 2.0 μm or less, it becomes easier to form irregularities on the surface of the first reflecting member 41. The range of the surface roughness Ra was determined with reference to the graph shown in FIG. 9, which shows the relationship between the surface roughness Ra and the matte finish.

[0040] The surface roughness Ra of the first reflecting member 41 can be the value measured over 2000 μm at a speed of 200 μm / s using, for example, a stylus-type step film thickness meter (Alpha-Step-IQ manufactured by KLA Tencor Corporation). In the light emitting device 100, a portion of the first hollow particles 52 is exposed from the first resin 51. However, as will be described later, the first hollow particles 52 may not be exposed from the first resin 51, and the surfaces of the first hollow particles 52 may be coated with the first resin 51. In addition, although the first hollow particles 52 are shown adjacent to each other in FIG. 8, the first hollow particles 52 may be interposed between the first hollow particles 52 with the first resin 51 interposed therebetween. Furthermore, the first hollow particles 52 may be a mixture of adjacent particles and particles interposed with the first resin 51 interposed therebetween.

[0041] The reflectance of the first reflecting member 41 is 40% or more. If the reflectance of the first reflecting member 41 is low, that is, if the transmittance of the first reflecting member 41 is high, light that passes through the first reflecting member 41 may be reflected by the first substrate 10, etc., resulting in the risk of stray light. Furthermore, the interior of the first reflecting member 41 may be visible, deteriorating the appearance. If the reflectance of the first reflecting member 41 is 40% or more, the reflectance of the first reflecting member 41 is excellent, and the above-mentioned problems can be suppressed. The reflectance in this specification is based on the emission peak wavelength of the light-emitting element, but may also be based on light of 450 nm.

[0042] The reflectance of the first reflecting member 41 is preferably 60% or more. If the reflectance of the first reflecting member 41 is 60% or more, the first reflecting member 41 can have better reflectance. There is no particular upper limit for the reflectance of the first reflecting member 41, but it may be, for example, 80% or less, or 90% or less. However, it is more preferable that the reflectance of the first reflecting member 41 be 95% or more.

[0043] The first reflecting member 41 contains a plurality of first hollow particles 52, and due to the difference in refractive index between the outer shell of the first hollow particles 52 and the internal cavity of the first hollow particles 52, the first reflecting member 41 can maintain a white appearance and can also maintain a high level of reflectance.

[0044] Examples of the first hollow particles 52 include hollow glass, hollow silica, porous silica, fly ash balloons, shirasu balloons, hollow polymer particles, etc. From the viewpoint of heat resistance, light resistance, etc., the plurality of first hollow particles 52 are preferably hollow silica or hollow glass.

[0045] The median diameter of the plurality of first hollow particles 52 is preferably 16 μm or more and 65 μm or less. If the median diameter is 16 μm or more, it becomes easier to form irregularities on the surface of the first reflecting member 41, and it becomes easier to control the surface roughness Ra of the first reflecting member 41. On the other hand, if the median diameter is 65 μm or less, the number of first hollow particles 52 contained in the first resin 51 increases, and it becomes easier to control the reflectance of the first reflecting member 41. From the viewpoint of making it easier to control the surface roughness Ra of the first reflecting member 41, the median diameter is more preferably 20 μm or more, and even more preferably 30 μm or more. Furthermore, from the viewpoint of making it easier to control the reflectance of the first reflecting member 41, the median diameter is more preferably 60 μm or less, and even more preferably 40 μm or less.

[0046] The median diameter refers to the particle size (volume median diameter) at which the volume cumulative frequency from the small diameter side reaches 50% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method. The laser diffraction / scattering particle size distribution measurement method can be performed using, for example, a laser diffraction particle size distribution measurement device (product name: MASTER SIZER3000, manufactured by MALVERN).

[0047] The content of the plurality of first hollow particles 52 contained in the first reflecting member 41 is preferably 20 parts or more and 70 parts or less relative to 100 parts by mass of the first resin 51. If the content of the plurality of first hollow particles 52 is 20 parts or more relative to 100 parts by mass of the first resin 51, it becomes easier to form irregularities on the surface of the first reflecting member 41 and to control the surface roughness Ra of the first reflecting member 41. On the other hand, if the content is 70 parts or less, it becomes easier to adjust the viscosity of the first resin 51 and to form the first reflecting member 41. The content of the plurality of first hollow particles 52 is more preferably 20 parts or more and 50 parts or less relative to 100 parts by mass of the first resin 51. If the content is 50 parts or less, it becomes easier to adjust the viscosity of the first resin 51. Furthermore, from the viewpoint of easier control of the surface roughness Ra of the first reflecting member 41, it is more preferably 30 parts or more. Note that "parts" refers to the mass (g) of the additive per 100 g of the resin matrix. In other words, the parts of the first hollow particles per 100 parts of the first resin are the parts by mass of the first hollow particles per 100 parts by mass of the first resin.

[0048] Examples of the first resin 51 include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, alkyd resin, acrylic resin, urethane resin, and hybrid resin containing at least one of these resins.

[0049] It is preferable that the first resin 51 has a higher viscosity than the resin constituting the covering member 40. The viscosity of the first resin 51 can be adjusted by, for example, the amount of viscosity adjusting filler contained in the first resin 51. The viscosity of the first resin 51 is preferably 200 Pa·s or more and 1200 Pa·s or less. If the viscosity of the first resin 51 is 200 Pa·s or more, it becomes easier to form the first reflecting member 41 into the desired shape. On the other hand, if the viscosity is 1200 Pa·s or less, the resin can be quickly discharged from the discharge device, improving workability. From the viewpoint of making it easier to form the first reflecting member 41 into the desired shape, the viscosity of the first resin 51 is more preferably 220 Pa·s or more, and even more preferably 250 Pa·s or more. Furthermore, from the viewpoint of making it easier to discharge the resin, the viscosity of the first resin 51 is more preferably 900 Pa·s or less, and even more preferably 550 Pa·s or less.

[0050] A nanofiller such as Aerosil (registered trademark) may be added to the first resin 51 to increase viscosity and impart thixotropy. In this embodiment, the first resin 51 contains a nanofiller 53. Examples of the nanofiller 53 include nanosilica. If a large amount of nanofiller 53 is added and the viscosity becomes too high, the viscosity can be reduced by adding a solvent. The solvent that can be used is preferably one that is compatible with the base resin. For example, when a silicone resin is used as the base material, aromatic hydrocarbons (xylene or toluene), petroleum hydrocarbons (benzine, petroleum ether, etc.), ethers (diethyl ether, THF, etc.), etc. can be used.

[0051] In the first reflecting member 41, a plurality of first hollow particles 52 are dispersed in the first resin 51. By dispersing the plurality of first hollow particles 52 in the first resin 51, the reflectance of the first reflecting member 41 is improved. In this embodiment, a plurality of first hollow particles 52 are dispersed in first resin 51 when the difference in the proportion of first hollow particles 52 between any two locations of the same area is less than 1.5 when observing a predetermined location on the cross section of first reflecting member 41. Specifically, the proportion (abundance rate) of first hollow particles 52 can be calculated as follows. First, a cross-sectional image of the first reflecting member 41 is captured, and the abundance ratio of the first hollow particles 52 is calculated at any two locations. The two images are captured at the same magnification, and the abundance ratio of the first hollow particles 52 is calculated by dividing the area of ​​the first hollow particles 52 by the area of ​​the resin portion in the cross-sectional image. Each area may be calculated from the cross-sectional image captured with an electron microscope (JSM-IT200 manufactured by JEOL Ltd.) using the measurement function of the electron microscope, or may be calculated from the mass of a cut-out piece of printed paper. The area of ​​the resin portion excludes areas other than the resin portion, such as the substrate, that appear in the photograph.

[0052] In the light emitting device 100, the angle formed between the first surface 10a of the first substrate 10 and the first reflecting member 41 is preferably 60 degrees or more and 135 degrees or less. If the angle is in this range, the first reflecting member 41 is easy to form, and the function of the first reflecting member 41 is further improved. The angle formed between the first surface 10a of the first substrate 10 and the first reflecting member 41 can be calculated by photographing a cross section of the first reflecting member 41 with a microscope (VHX-700F manufactured by Keyence Corporation) and using the measurement function to measure the angle θ between the first surface 10a of the first substrate 10 and the outer periphery of the first reflecting member 41, as shown in Figure 10.

[0053] The second reflecting member 42 is located below the light emitting element 1 and the light-transmitting member 5 in the light emitting device 100. (i.e., the side opposite to the light extraction side). Therefore, the second reflecting member 42 may or may not be translucent to the light emitted from the light-emitting element 1. The second reflecting member 42 can be used as a dam to hold back the uncured covering member 40 in the manufacturing process, similar to the first reflecting member 41. Therefore, it is preferable that the second reflecting member 42 is disposed in the same process as the first reflecting member 41 or in a subsequent process, and from the viewpoint of simplifying the manufacturing method, it is preferable that the second reflecting member 42 be disposed using the same resin as the first resin 51 of the first reflecting member 41.

[0054] The second reflecting member 42 may have a surface roughness Ra of 0.10 μm or more and 3.0 μm or less, and may have a reflectance of 40% or more, similar to the first reflecting member 41. Other configurations may also be similar to those of the first reflecting member 41.

[0055] The light emitting device 100 having the above configuration can be used as a light source for a vehicle headlight, for example. In this case, for example, a configuration is adopted in which light is emitted from the light source to the outside through a lens. In the light emitting device 100, the light emitting elements 1 are turned on by an external power switch. Note that the light emitting device 100 is configured so that some or all of the preset light emitting elements 1 can be individually driven.

[0056] Light-emitting devices have been developed that can change the light distribution of vehicle headlights, for example, and specific examples include those that use an array of multiple LEDs, or LEDs (multi-chip type) that are equipped with multiple light-emitting elements and can be turned on individually. The light emitted from these LEDs is irradiated forward through the lens of the lamp, but for precise light distribution control, the directionality of the light is becoming increasingly important. One known method for manufacturing a light-emitting device involves forming a frame made of reflective resin around the light-emitting element and filling the inside of the frame with a low-viscosity reflective resin. However, this method can cause stray light when diffused light reflected from the headlight or lighting fixture is reflected by the reflective resin. This stray light can then pass through the lens, resulting in an unintended illumination pattern. One way to deal with stray light is to make the resin part black to absorb excess light, but this would reduce the LED output. Also, if sunlight enters the lighting fixture, it could absorb the light and cause the black resin part to burn. Similar concerns arise when fillers that absorb shortwave light, such as titanium oxide, are added. One way to deal with external light reflection on the light-emitting surface and sealing surface is to make the outermost surface uneven, but there was no way to deal with this for the resin frame.

[0057] In contrast, in the light emitting device 100 of this embodiment, the first hollow particles 52 form unevenness on the surface of the first reflecting member 41. Furthermore, since the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less, light striking the first reflecting member 41 is diffused, suppressing the generation of stray light. This allows a desired irradiation pattern to be obtained, and when used in combination with a lens, the optical design of the lens can be easily performed. Furthermore, since the first reflecting member 41 contains a plurality of first hollow particles 52, the reflectance of the first reflecting member 41 can be made 40% or more. This results in excellent reflectance of the first reflecting member 41.

[0058] [Method of manufacturing a light-emitting device] Next, an example of a method for manufacturing the light emitting device according to the embodiment will be described. Fig. 11 is a flowchart illustrating a method for manufacturing a light emitting device according to an embodiment. Figs. 12A to 12H are plan views schematically illustrating the method for manufacturing a light emitting device according to an embodiment. Fig. 12C is an enlarged plan view schematically illustrating the method for manufacturing a light emitting device according to an embodiment. The light emitting elements 1 are placed at predetermined intervals, but the intervals are omitted in the drawings other than the enlarged plan view of Fig. 12C.

[0059] A method for manufacturing light emitting device 100 includes the steps of preparing an intermediate body having substrate 10 with first surface 10a and one or more light emitting elements 1 arranged on first surface 10a of substrate 10, and a mixture of first resin 51 and a plurality of first hollow particles 52, applying the mixture to first surface 10a of substrate 10 so as to surround light emitting element 1, and curing the mixture to form first reflecting member 41. After the step of forming first reflecting member 41, first hollow particles 52 form unevenness on the surface of first reflecting member 41, and after the step of forming first reflecting member 41, first reflecting member 41 has a surface roughness Ra of 0.10 μm or more and 3.0 μm or less, and a reflectance of first reflecting member 41 of 40% or more.

[0060] Furthermore, in the preparation step, a solvent may be further mixed into the mixture, and the solvent in the mixture may be volatilized and the mixture may be hardened in the step of forming first reflecting member 41. In this embodiment, a case where a solvent is mixed into the mixture will be described.

[0061] Specifically, the method for manufacturing the light emitting device 100 includes an intermediate and mixture preparation step S101, a first reflecting member arrangement step S102, a second reflecting member arrangement step S103, and a covering member arrangement step S104. The intermediate and mixture preparing step S101 includes an element placing step S11, a third reflecting member placing step S12, a substrate placing step S13, a wire connecting step S14, a light-transmitting member placing step S15, and a mixture preparing step S16. The first reflecting member placing step S102 includes a mixture applying step S17 and a first reflecting member forming step S18. Each step will be described below. Note that the materials and arrangement of each component are the same as those described above in connection with the light emitting device 100, and therefore will not be described here as appropriate.

[0062] The element mounting step S11 is a step of mounting a plurality of light-emitting elements 1 on the element mounting region 13 of the first substrate 10 (see FIGS. 12A and 12B). In the element mounting step S11, a support substrate is prepared in which a plurality of light-emitting elements 1 are arranged at predetermined intervals, and the plurality of light-emitting elements 1 are attached to the element mounting region 13 of the first substrate 10, and then the support substrate is peeled off. Note that, before performing the element mounting step S11, it is preferable to prepare the first substrate 10 on which wiring such as first terminals 110 is arranged in advance. The first terminals 110 can be formed by attaching a metal foil such as Cu or Al, applying a paste of metal powder such as Cu or Ag, plating with Cu, or the like. Furthermore, wiring electrically connected to the light-emitting elements 1 in the element mounting region 13 can be patterned by etching, printing, or the like. Note that the first substrate 10 may be prepared by purchasing, etc. The light emitting element 1 can be electrically connected to the element mounting region 13 on the first substrate 10 by, for example, plating.

[0063] The third reflecting member arrangement step S12 is a step of covering the side surfaces of the light-emitting elements 1 with the third reflecting member 7 after the light-emitting elements 1 are mounted on the element mounting region 13 of the first substrate 10 (see FIGS. 12B and 12C). Here, after the light-emitting elements 1 are mounted on the first substrate 10, the third reflecting member 7, such as a white resin, is arranged between the light-emitting elements 1. In the third reflecting member arrangement step S12, the upper surface of the light-emitting element 1 is covered with a mask before the third reflecting member 7 is arranged, and the mask is removed after the third reflecting member 7 is arranged, so that the upper surface of the light-emitting element 1 can be exposed from the third reflecting member 7.

[0064] The substrate placement step S13 is a step of placing the first substrate 10 on the substrate placement area 23 of the second substrate 20 (see FIGS. 12D and 12E). Here, the first substrate 10 on which the light-emitting element 1 is placed is placed on the substrate placement area 23 of the second substrate 20 and bonded via a bonding material such as sintered metal, for example, sintered Ag or sintered Cu. Note that, before performing the substrate placement step S13, it is preferable to prepare the second substrate 20 on which wiring such as the second terminal 120 is arranged in advance.

[0065] The wire connection step S14 is a step of connecting the first terminals 110 of the first substrate 10 and the second terminals 120 of the second substrate 20 with wires 130 (see FIG. 12F). Specifically, the first external connection terminals 11 of the first substrate 10 are connected to the first wire connection terminals 21 of the second substrate 20 with a plurality of first wires 31, and the second external connection terminals 12 of the first substrate 10 are connected to the second wire connection terminals 22 of the second substrate 20 with a plurality of second wires 32. The wire connection step S14 also includes a step of connecting the first drive terminal 15 of the first substrate 10 to the second drive terminal 16 of the second substrate 20 with a third wire 33.

[0066] The light-transmitting member arrangement step S15 is a step of arranging a light-transmitting member 5 that covers the plurality of light-emitting elements 1 (see FIG. 12G). The light-transmitting member 5 is prepared in advance in a sheet shape of a predetermined size and is arranged on the light-emitting elements 1. The light-transmitting member 5 may be fixed to the light-emitting elements 1 via a light-transmitting bonding member such as resin, or may be fixed by utilizing the tackiness of the light-transmitting member 5 without using a bonding member.

[0067] The mixture preparation step S16 is a step of preparing a mixture of a first resin 51 and a plurality of first hollow particles 52. Here, a solvent and nanofiller 53 are further mixed. Mixing the solvent makes it easier to mix the components. Furthermore, mixing the nanofiller 53 makes it easier to adjust the viscosity of the mixture. The amount of each component is adjusted appropriately so that the first reflecting member 41 has the desired configuration. The mixture is prepared, for example, by placing each component in a dedicated mixing vessel, mixing by hand with a spatula, and then stirring with a mixer.

[0068] In the preparation step, the content of the solvent in the mixture is preferably 1 part or more and 30 parts or less per 100 parts by mass of first resin 51. If the content is 1 part or more per 100 parts by mass of first resin 51, it becomes easier to mix the components. On the other hand, if the content is 30 parts or less, it becomes easier to volatilize the solvent when the mixture is cured, making it easier to form irregularities on the surface of first reflecting member 41. The mixture preparation step S16 may be performed before the light-transmitting member arrangement step S15. That is, the mixture may be prepared in advance and stirred again immediately before the mixture is applied in the mixture application step S17.

[0069] The first reflecting member arrangement step S102 is a step of arranging a first reflecting member 41 on the upper surface of the first substrate 10 between the element mounting region 13 and the first terminal 110 so as to be aligned with the element mounting region 13 (see FIG. 12H). The first reflecting member arrangement step S102 includes a mixture application step S17 and a first reflecting member formation step S18.

[0070] The mixture application step S17 is a step of applying the mixture to the first surface 10a of the first substrate 10 so as to surround the light emitting element 1. In the mixture application step S17, the uncured mixture for forming the first reflecting member 41 is supplied from the nozzle of a dispenser while the nozzle is moved along the element mounting region 13 to apply the mixture for forming the first reflecting member 41. When applying the mixture, in order to disperse the first hollow particles 52 in the first resin 51, it is preferable to manually stir the mixture, for example, at 1000 rpm or higher for 1 minute or more, and then start application within 30 minutes.

[0071] The first reflecting member forming step S18 is a step of curing the mixture to form first reflecting member 41. The mixture is cured, for example, at a temperature of 140°C or higher and 160°C or lower for 2 hours or higher and 6 hours or lower. In the first reflecting member forming step S18, the solvent volatilizes as the mixture cures, reducing the amount of the mixture, and first hollow particles 52 are arranged on the surface of first reflecting member 41, forming unevenness on the surface of first reflecting member 41.

[0072] After the step of forming the first reflecting member 41, the first hollow particles 52 form unevenness on the surface of the first reflecting member 41, and the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less. After the step of forming the first reflecting member 41, the surface roughness Ra of the first reflecting member 41 is preferably 0.50 μm or more and 2.0 μm or less. Furthermore, after the step of forming the first reflecting member 41, the reflectance of the first reflecting member 41 is 40% or more. After the step of forming the first reflecting member 41, the reflectance of the first reflecting member 41 is preferably 60% or more. Furthermore, after the step of forming the first reflecting member 41, the angle formed between the first surface 10a of the substrate 10 and the first reflecting member 41 is preferably 60 degrees or more and 135 degrees or less. These matters are as described above in the description of the light emitting device 100.

[0073] The second reflecting member arrangement step S103 is a step of arranging the second reflecting member 42 on the upper surface of the second substrate 20, outside the second terminal 120 (see FIG. 12H). Note that it is preferable to use the same material for the first reflecting member 41 and the second reflecting member 42, so that the first reflecting member arrangement step S102 and the second reflecting member arrangement step S103 can be performed as the same step. In the first reflecting member arranging step S102 and the second reflecting member arranging step S103, the second reflecting member 42 may be arranged first in the second reflecting member arranging step S103, and then the first reflecting member 41 may be arranged in the first reflecting member arranging step S102. Furthermore, the first reflecting member arranging step S102 may be performed simultaneously with the second reflecting member arranging step S103, so that the first reflecting member 41 and the second reflecting member 42 are arranged substantially simultaneously.

[0074] The covering member arrangement step S104 is a step of arranging a light-blocking covering member 40 on the outer side of the first reflecting member 41, in contact with the first reflecting member 41, and covering the wire 130. Specifically, this is a step of arranging a light-blocking covering member 40 between the first reflecting member 41 and the second reflecting member 42, the light-blocking covering member 40 having a base material of a resin with a lower viscosity than the first reflecting member 41 and the second reflecting member 42. The covering member 40 is arranged across the first substrate 10 and the second substrate 20. Therefore, the covering member 40 also covers the side surfaces of the first substrate 10.

[0075] Although the present invention has been specifically described above using the preferred embodiments, the scope of the present invention is not limited to these descriptions and should be broadly interpreted based on the claims. Furthermore, various changes and modifications based on these descriptions are also included in the scope of the present invention. The following describes the modified examples. Note that the materials and arrangement of each member are the same as those described in the embodiment, and therefore, the description will be omitted here as appropriate.

[0076] <<Variation>> 13A to 13D are enlarged cross-sectional views schematically showing a portion of the first reflecting member in first to fourth modified examples of the embodiment, respectively. FIG. 14 is a cross-sectional view schematically showing a fifth modified example of the embodiment. FIG. 15 is a partial cross-sectional view in the fifth modified example of the embodiment. FIG. 16 is an enlarged cross-sectional view schematically showing a portion of the sealing member in the fifth modified example of the embodiment. Note that FIG. 16 schematically shows the portion indicated by the symbol B in FIG. 15. Furthermore, the same symbols are used to denote components that have already been described, and descriptions thereof will be omitted, or descriptions will be omitted to avoid repetition of the same description.

[0077] The first hollow particles 52 may be a combination of multiple first hollow particles with different particle sizes. Alternatively, the first hollow particles 52 may be used in combination with one or more of oxide particles containing Ti, Zn, Zr, Al, Si, etc., solid spherical particles, and particles with a refractive index different from that of the first resin 51, such as AlN or MgF. Since the amount of light reflection and transmittance varies depending on the concentration and density of these particles, the amount and density of addition are adjusted according to the shape and size of the light emitting device. The first reflecting member may also contain other particles as fillers, etc. The mixing ratio of each particle contained in the first reflecting member is adjusted to achieve the desired surface roughness Ra and reflectance. Specifically, the first reflecting member may have a configuration as shown in FIGS. 13A to 13C.

[0078] [First Modification] 13A, first reflecting member 41A contains first hollow particles 52a with a large median diameter and first hollow particles 52b with a small median diameter. Even with this configuration, it is possible to increase the reflectance of first reflecting member 41A and suppress the generation of stray light.

[0079] [Second Modification, Third Modification] As shown in FIG. 13B, first reflecting member 41B contains oxide particles . 13C, first reflecting member 41C contains solid spherical particles 55. Examples of spherical particles 55 include silica and glass. The oxide particles 54 and the spherical particles 55 have a smaller median diameter than the first hollow particles 52, and therefore enter the gaps between the first hollow particles 52. This configuration can improve reflectance. The oxide particles 54 and the spherical particles 55 are partially exposed from the first resin 51. However, the oxide particles 54 and the spherical particles 55 may not be exposed from the first resin 51, and the surfaces of the oxide particles 54 and the spherical particles 55 may be covered with the first resin 51.

[0080] [Fourth Modification] 13D, in first reflecting member 41D, first hollow particles 52 are not exposed from first resin 51, and the surfaces of first hollow particles 52 are coated with first resin 51. With this configuration, even if first hollow particles 52 are not exposed from first resin 51 due to the amount of solvent mixed into the mixture or the amount of solvent to be evaporated during production of a light emitting device, for example, it is possible to increase the reflectance of first reflecting member 41D and suppress the generation of stray light.

[0081] [Fifth Modification] The light emitting device 100A has a light emitting element 1A mounted face-up on a substrate 10. The light emitting element 1A has positive and negative electrodes disposed on the surface of a semiconductor laminate electrically connected to the first substrate 10 via element wires 34. The light emitting device 100A further has a sealing member 60 covering the light emitting element 1A on the first surface 10a of the substrate 10, the sealing member 60 having a second resin 61 and a plurality of second hollow particles 62 contained in the second resin 61. The sealing member 60 covers the light emitting element 1A and the element wires 34 in a plan view. The sealing member 60 can protect the light emitting element 1A and the like from external forces, dust, moisture, and the like.

[0082] The sealing member 60 contains a plurality of second hollow particles 62 in a second resin 61. The second hollow particles 62 are preferably unevenly distributed on the surface side of the sealing member 60. By unevenly distributing the second hollow particles 62 on the surface side of the sealing member 60, it is possible to form irregularities on the surface of the sealing member 60. This makes it possible to suppress shine on the sealing member 60 due to external light. The surface roughness Ra of the sealing member 60 is preferably 0.10 μm or more and 3.0 μm or less. If the surface roughness Ra of the sealing member 60 is 0.10 μm or more, shine on the sealing member 60 is further suppressed. On the other hand, if it is 3.0 μm or less, it becomes easier to form irregularities on the surface of the sealing member 60.

[0083] The second hollow particles 62 being unevenly distributed on the surface side of the sealing member 60 means that, when observing a predetermined location on a cross section of the sealing member 60 in a direction perpendicular to the first surface 10a of the first substrate 10, the ratio of the second hollow particles 62 present on the surface side differs by 1.5 times or more from the ratio of the second hollow particles 62 present on the bottom side. Specifically, the ratio (abundance rate) of the second hollow particles 62 can be calculated as follows. First, a cross-sectional image of the sealing member 60 is taken, and the abundance ratio of the second hollow particles 62 is calculated in an image of the front side including the front surface and an image of the bottom side including the bottom surface. The images of the front side and the bottom side are taken at the same magnification, and the abundance ratio of the second hollow particles 62 is calculated by dividing the area of ​​the second hollow particles 62 by the area of ​​the resin portion in the cross-sectional image. The respective areas may be calculated from the cross-sectional image taken with an electron microscope (JSM-IT200 manufactured by JEOL Ltd.) using the measurement function of the electron microscope, or may be calculated from the mass of a cut-out piece of printed paper. The area of ​​the resin portion is the area excluding the non-resin portion of the substrate and other parts shown in the photograph.

[0084] In the light emitting device 100A, a portion of the second hollow particles 62 is exposed from the second resin 61. However, the second hollow particles 62 may not be exposed from the second resin 61, and the surfaces of the second hollow particles 62 may be coated with the second resin 61. In addition, although the second hollow particles 62 are shown adjacent to each other in FIG. 16, the second hollow particles 62 may be interposed between the second hollow particles 62 with the second resin 61 interposed therebetween. Furthermore, the second hollow particles 62 may be interposed between adjacent particles and with the second resin 61 interposed therebetween. The second hollow particles 62 can be the same as the first hollow particles 52. The median diameter of the plurality of second hollow particles 62 is preferably 16 μm or more and 65 μm or less. More preferably, it is 20 μm or more, and even more preferably, it is 30 μm or more. Furthermore, it is more preferably 60 μm or less, and even more preferably, it is 40 μm or less. Furthermore, the plurality of second hollow particles 62 are preferably hollow silica or hollow glass. This is for the same reasons as in the case of the first hollow particles 52. The second resin 61 can be the same as the first resin 51.

[0085] The sealing member 60 may contain nanofillers 53. The plurality of second hollow particles 62 may be a combination of second hollow particles with different particle sizes. As with the first reflecting member, the second hollow particles 62 may be used in combination with one or more of oxide particles 54, solid spherical particles 55, and particles with a refractive index different from that of the second resin 61 base material. The sealing member 60 may also contain other particles as fillers or the like. Furthermore, the sealing member 60 may contain a wavelength conversion member. Examples of wavelength conversion members include phosphors. Examples of phosphors include those exemplified for the light-transmitting member 5 of the light emitting device 100.

[0086] The manufacturing method of the light emitting device 100A may include the steps of disposing the light emitting element 1A on the first surface 10a of the first substrate 10, connecting the element wires 34, forming the first reflecting member 41, and then disposing the sealing member 60 within the frame of the first reflecting member 41. In the step of disposing the sealing member 60, a second resin 61 mixed with second hollow particles 62 is disposed within the frame by, for example, potting or spraying. Thereafter, the second resin 61 is cured at a temperature of, for example, 120°C or higher and 200°C or lower, to form the sealing member 60. Note that it is preferable to adjust the viscosity of the second resin 61 so that the second hollow particles 62 are unevenly distributed on the surface side of the sealing member 60.

[0087] Additionally, although the light emitting device has a plurality of light emitting elements, it may have only one light emitting element. Also, the light emitting device may not have a second reflecting member and a covering member. The method for manufacturing a light emitting device may include other processes between, before, or after the above-described processes, as long as they do not adversely affect the above-described processes. For example, it may include a foreign matter removal process for removing foreign matter that has been mixed in during the manufacturing process. Furthermore, the respective steps may be performed in an order as far as possible. Furthermore, the solvent may not be mixed in the mixture preparation step. [Example]

[0088] Examples will be described below. Nos. A1 to A9 are examples that satisfy the configuration of the embodiment, and Nos. B1 to B3 are comparative examples that do not satisfy the configuration of the embodiment.

[0089] [No.A1] (Resin blending) 10 g of base resin OE-6351 (dimethyl silicone manufactured by DuPont Toray Specialty Materials Co., Ltd.) was placed in a special mixing vessel (High Resist Container BHR-150 manufactured by Kinki Yoki Co., Ltd.), 1 g (10 parts) of nanosilica (RX200 manufactured by Nippon Aerosil Co., Ltd.), 5 g (50 parts) of hollow glass with a median diameter of 20 μm (Glass Bubbles iM16K manufactured by 3M), and 0.5 g (5 parts) of toluene as a solvent were added and mixed thoroughly by hand with a spatula, and then the mixture was stirred uniformly at 1200 pm / 3 minutes using a mixer (Thinky Corporation Awatori Rentaro ARV-310LED).

[0090] (Viscosity measurement of resin) After stirring, the viscosity of the resin was measured at 25°C and 1 rpm using an E-type viscometer (TV-33 manufactured by Toki Sangyo Co., Ltd.).

[0091] (Measurement of transmittance and reflectance of cured products) A frame made of two overlapping 0.18 μm fluororesin tapes was attached to a glass slide. The stirred resin was poured inside the frame, and the thickness was adjusted to the maximum using a squeegee. The resin was then cured at 150°C for 4 hours. The transmittance of the cured sample was measured using a spectrophotometer (U-3900, Hitachi High-Tech Science Corporation) set so that light was incident on the resin surface, and the transmittance spectrum was measured. The value at 470 nm in the resulting transmittance spectrum was recorded as the transmittance. The reflectance was measured using a spectrophotometer (CMS-35SP, Murakami Color Research Institute Co., Ltd.) set so that light was incident on the resin surface, and the reflectance spectrum was measured under conditions including specular reflection. The value at 470 nm in the resulting reflectance spectrum was recorded as the reflectance.

[0092] (Measurement of surface roughness Ra of cured product) The stirred resin was placed in a syringe fitted with a 0.66 mm needle and dispensed in a line onto an alumina ceramic substrate using a dispenser (ML-5000XII manufactured by Musashi Engineering Co., Ltd.), followed by curing at 150°C for 4 hours. The cured product was measured over 2000 μm at a speed of 200 μm / s using a stylus-type step film thickness meter (Alpha-Step-IQ manufactured by KLA Tencor Corporation), and the value measured was taken as the surface roughness Ra.

[0093] (Measurement of the angle between the substrate and the cured product) The resin cured on the ceramic substrate was cut out with a cutter knife, and the cross section was photographed with a microscope (Keyence Corporation VHX-700F). The angle between the surface that was in contact with the substrate and the outer periphery of the cured product was calculated using the measurement function.

[0094] [No.A2] 10 parts of nanosilica (RX200) and 50 parts of hollow glass (Glass Bubbles iM16K) with a median diameter of 20 μm were added to 10 g of base resin OE-6351 and stirred thoroughly, then coated and cured on a ceramic substrate. The resin blending, curing, resin viscosity measurement, and cured product measurement were all performed in the same manner as No. A1.

[0095] [No.A3] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 50 parts of hollow glass (Glass Bubbles S38) with a median diameter of 40μm, and 5 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all carried out in the same manner as No. A1.

[0096] [No.A4] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 30 parts of hollow glass (Glass Bubbles K1) with a median diameter of 65μm, and 30 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all performed in the same manner as No. A1.

[0097] [No.A5] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 25 parts of hollow glass particles (Glass Bubbles iM30K) with a median diameter of 16μm, 25 parts of hollow glass particles (Glass Bubbles S38) with a median diameter of 40μm, and 3 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all performed using the same methods as No. A1.

[0098] [No.A6] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 40 parts of hollow glass (Glass Bubbles S38) with a median diameter of 40μm, 10 parts of solid spherical silica (Adma Fine SO-C2 manufactured by Admatechs Co., Ltd.) with a median diameter of 0.5μm, and 5 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, measurement of resin viscosity, and measurement of the cured product were all carried out using the same methods as No. A1.

[0099] [No.A7] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 40 parts of hollow glass (Glass Bubbles S38) with a median diameter of 40μm, 10 parts of titanium dioxide (R-960 manufactured by Chemours Inc.) with a median diameter of 0.5μm, and 5 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all carried out using the same methods as No. A1.

[0100] [No.A8] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 25 parts of hollow glass particles (Glass Bubbles iM30K) with a median diameter of 16μm, 25 parts of hollow glass particles (Glass Bubbles S38) with a median diameter of 40μm, 10 parts of alumina (Sumicorundum AA-03 manufactured by Sumitomo Chemical Co., Ltd.) with a median diameter of 0.8μm, and 3 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all performed using the same methods as for No. A1.

[0101] [No.A9] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 20 parts of hollow glass (Glass Bubbles K1) with a median diameter of 65μm, and 5 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all carried out in the same manner as No. A1.

[0102] [No.B1] To 10 g of base resin OE-6351, 10 parts of nanosilica (RX200), 100 parts of titanium dioxide (R-960 manufactured by Chemours Inc.) with a median diameter of 0.5 μm, and 10 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, measurement of resin viscosity, and measurement of the cured product were all carried out in the same manner as No. A1.

[0103] [No.B2] To 10 g of base resin OE-6351, 10 parts of nanosilica (RX200), 400 parts of solid spherical silica with a median diameter of 20 μm (Kicross FR-2400TS manufactured by Tatsumori Co., Ltd.), and 10 parts of toluene as a solvent were added and stirred well, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and measurement of the cured product were all carried out in the same manner as No. A1.

[0104] [No.B3] 10 parts of hollow glass (Glass Bubbles S38) with a median diameter of 40 μm was added to 10 g of base resin OE-6351 and stirred thoroughly, then coated and cured on a ceramic substrate. The resin preparation, curing, resin viscosity measurement, and cured product measurements were all performed in the same manner as No. A1.

[0105] These results are shown in Table 1. In Table 1, the values ​​that could not be measured are indicated by "-".

[0106] [Table 1]

[0107] As shown in Table 1, Nos. A1 to A9 satisfied the constitution of the embodiment, and therefore the reflectance and surface roughness of the cured product were good. The detailed results are as follows. No. A1 was prepared by adding a solvent, and had a larger surface roughness Ra than No. A2, which was prepared without adding a solvent. No. A3 and No. A4 had larger median diameters of hollow glass particles than No. A1, and had larger surface roughness Ra than No. A1. However, the reflectance was slightly lower. No. A4 had a larger median diameter of hollow glass particles than No. A3, and had a larger surface roughness Ra than No. A3. However, the reflectance was slightly lower. No. A4 also had a larger amount of hollow glass particles added than No. A9, and had a larger surface roughness Ra and higher reflectance than No. A9.

[0108] No. A5 is a combination of two types of hollow glass with different median diameters, and has a higher reflectance than No. A4. However, the surface roughness Ra is slightly smaller. No. A6 is a combination of hollow glass and solid spherical silica, and has a larger surface roughness Ra than No. A3, but the reflectance is slightly lower. No. A7 was made by replacing the spherical silica of No. A6 with titanium oxide of the same median diameter, and had a higher reflectance than No. A6. No. A7 had the best balance between reflectance and surface roughness Ra. No. A8 is a combination of two types of hollow glass with different median diameters and solid alumina, and has a higher reflectivity than No. A5.

[0109] On the other hand, Nos. B1 to B3 did not satisfy the configuration of the embodiment, and therefore the following results were obtained. No. B1 used titanium oxide instead of hollow particles, so although the reflectance was high, the surface roughness Ra was small. No. B2 used spherical silica instead of hollow particles, so although the surface roughness Ra was large, the reflectance was low. In No. B3, the amount of hollow glass added was small, which resulted in a low viscosity of the resin, making it impossible to form a cured product in the desired shape. As a result, the angle between the cured resin and the substrate was also very small. [Industrial Applicability]

[0110] Light emitting devices according to embodiments of the present disclosure can be used in various light sources such as vehicle headlights and projectors. [Explanation of symbols]

[0111] 1,1A light emitting element 5 Translucent material 7 Third reflecting member 10 First board (board) 10a: First surface of first substrate (substrate) 110 1st terminal 11 First external connection terminal 12 Second external connection terminal 13 Element mounting area 15 First drive terminal 16 Second drive terminal 20 Second board 120 2nd terminal 21 First wire connection terminal 22 Second wire connection terminal 23 Substrate placement area 130 wire 130a Top of wire 31 First Wire 32 Second Wire 33 Third Wire 34 Wire for element 40 Covering material 40a Top of covering member 41a Top of first reflecting member 41, 41A, 41B, 41C, 41D First reflecting member 42 Second reflecting member 51 First Resin 52 1st hollow particle 52a First hollow particle with large median diameter 52b First hollow particles with small median diameter 53 Nanofiller 54 Oxide particles 55 Spherical particles 60 Sealing member 61 Second Resin 62 2nd hollow particle 100,100A light emitting device

Claims

1. a substrate having a first surface; one or more light emitting elements disposed on a first surface of the substrate; a first reflecting member that surrounds the light-emitting element and is disposed on the first surface of the substrate; the first reflecting member includes a first resin and a plurality of first hollow particles contained in the first resin; the first hollow particles form irregularities on the surface of the first reflecting member, A light emitting device, wherein the surface roughness Ra of the first reflecting member is 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflecting member is 40% or more.

2. 2. The light emitting device according to claim 1, wherein the first reflecting member has a surface roughness Ra of 0.50 [mu]m or more and 2.0 [mu]m or less.

3. 3. The light emitting device according to claim 1, wherein the first reflecting member has a substantially semicircular or semielliptical cross section in a direction perpendicular to the first surface of the substrate.

4. 4. The light emitting device according to claim 1, wherein the plurality of first hollow particles have a median diameter of 16 μm or more and 65 μm or less.

5. 5. The light emitting device according to claim 1, wherein the plurality of first hollow particles are hollow silica or hollow glass.

6. 6. The light emitting device according to claim 1, wherein a content of the plurality of first hollow particles is 20 parts or more and 50 parts or less with respect to 100 parts by mass of the first resin.

7. a sealing member for covering the light-emitting element on the first surface of the substrate; 7. The light emitting device according to claim 1, wherein the sealing member comprises a second resin and a plurality of second hollow particles contained in the second resin.

8. The light emitting device according to claim 7 , wherein the second hollow particles are unevenly distributed on the surface side of the sealing member.

9. 9. The light emitting device according to claim 7, wherein the plurality of second hollow particles have a median diameter of 16 μm or more and 65 μm or less.

10. 10. The light emitting device according to claim 7, wherein the plurality of second hollow particles are hollow silica or hollow glass.

11. 11. The light emitting device according to claim 1, wherein the reflectance of the first reflecting member is 60% or more.

12. preparing an intermediate body including a substrate having a first surface and one or more light-emitting elements disposed on the first surface of the substrate, and a mixture obtained by mixing a first resin and a plurality of first hollow particles; applying the mixture to a first surface of the substrate so as to surround the light-emitting element; and curing the mixture to form a first reflective member; after the step of forming the first reflecting member, the first hollow particles form irregularities on the surface of the first reflecting member, A method for manufacturing a light emitting device, wherein the first reflecting member has a surface roughness Ra of 0.10 μm or more and 3.0 μm or less, and the first reflecting member has a reflectance of 40% or more.

13. In the preparing step, a solvent is further mixed into the mixture, The method for manufacturing a light emitting device according to claim 12 , wherein in the step of forming the first reflecting member, the solvent in the mixture is volatilized and the mixture is cured.

14. 14. The method for manufacturing a light emitting device according to claim 13, wherein in the preparing step, the content of the solvent in the mixture is 1 part to 30 parts with respect to 100 parts by mass of the first resin.

15. 15. The method for manufacturing a light emitting device according to claim 12, wherein the first reflecting member has a surface roughness Ra of 0.50 μm or more and 2.0 μm or less after the step of forming the first reflecting member.

16. 16. The method for manufacturing a light emitting device according to claim 12, wherein the reflectance of the first reflecting member after the step of forming the first reflecting member is 60% or more.

17. 17. The method for manufacturing a light emitting device according to claim 12, wherein after the step of forming the first reflecting member, the angle formed between the first surface of the substrate and the first reflecting member is 60 degrees or more and 135 degrees or less.

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