Light-emitting device

Abstract

To provide a light-emitting device and a manufacturing method thereof, in which the reflectance of a reflective member surrounding a light emitting element is high and the generation of stray light can be suppressed.SOLUTION: A light-emitting device 100 includes a substrate 10 having a first side, one or more light emitting elements 1 arranged on the first surface of the substrate 10, a first reflecting member 41 surrounding the light emitting element 1 and arranged on the first surface of the substrate 10, and the first reflecting member 41 includes a first resin, and a plurality of first hollow particles contained in the first resin, and concavities and convexities are formed on the surface of the first reflecting member 41 by the first hollow particles, and the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflecting member 41 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 Art

[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 is formed of a light-reflective resin around a light-emitting element, and a low-viscosity light-reflective resin is filled inside the frame. Further, for example, Patent Document 2 discloses a light-emitting device in which the surface of a sealing member for sealing a light-emitting element has irregularities formed due to particles of a filler.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a light-emitting device and a method for manufacturing the same, in which a reflectance of a reflecting member surrounding a light-emitting element is high and generation of stray light can be suppressed.

Means for Solving the Problems

[0005] A light-emitting device according to an embodiment of the present disclosure includes a substrate having a first surface, one or more light-emitting elements disposed on the first surface of the substrate, and 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. Concavities and convexities are formed on the surface of the first reflecting member by the first hollow particles, a surface roughness Ra of the first reflecting member is 0.10 μm or more and 3.0 μm or less, and a reflectance of the first reflecting member is 40% or more.

[0006] The manufacturing method of a light-emitting device according to an embodiment of the present disclosure includes an intermediate body having a substrate with a first surface and one or more light-emitting elements disposed on the first surface of the substrate, and a step of preparing a mixture of a first resin and a plurality of first hollow particles, a step of applying the mixture to the first surface of the substrate so as to surround the light-emitting elements, and a step of curing the mixture to form a first reflective member. After the step of forming the first reflective member, irregularities are formed on the surface of the first reflective member by the first hollow particles, the surface roughness Ra of the first reflective member is 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflective member is 40% or more.

Advantages of the Invention

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

Brief Description of the Drawings

[0008]

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Mode for Carrying Out the Invention

[0009] 《Embodiment》 Hereinafter, a light-emitting device and a method for manufacturing the same according to an embodiment will be described with reference to the drawings. Note that the sizes and positional relationships of the members shown in the respective drawings may be exaggerated for clarity of explanation. Also, the dimensions and arrangement positions of the members may not exactly match between the plan view and the corresponding cross-sectional view. To avoid making the drawings overly complex, there are cases where the illustration of some elements is omitted or an end view showing only the cut surface is used as a cross-sectional view. Further, in the following description, up, down, left, right, front, and rear are relative and do not indicate absolute directions. And for the same names and reference numerals, in principle, the same or similar members are indicated, and detailed descriptions may be appropriately omitted. Also, for the embodiment, "coating" and "covering" include not only the case of direct contact but also the case of indirectly covering, for example, via other members. In this specification, a plan view means observing 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 the light-emitting device according to the embodiment. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. FIG. 5 is a cross-sectional view taken along line V-V of FIG. 2. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 2. FIG. 7 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. 8 is an enlarged cross-sectional view schematically showing a part of the first reflecting member of the light-emitting device according to the embodiment. Note that FIG. 8 schematically shows a portion denoted by reference sign A in FIG. 5. FIG. 9 is a graph showing the relationship between surface roughness Ra and matting. FIG. 10 is a schematic cross-sectional view for explaining a method of measuring an angle formed by the first surface of the substrate and the first reflecting member. In the drawings, although the first wire 31, the second wire 32, the third wire 33, etc. disposed inside the covering member 40 may not be visible, for convenience of explanation, the first wire 31, etc. are shown in a visible form.

[0011] The light-emitting device 100 includes a substrate 10 having a first surface 10a, one or more light-emitting elements 1 disposed on the first surface 10a of the substrate 10, and a first reflecting member 41 that surrounds the light-emitting element 1 and is disposed on the first surface 10a of the substrate 10. The first reflecting member 41 includes a first resin 51 and a plurality of first hollow particles 52 contained in the first resin 51. Concavities and convexities are formed on the surface of the first reflecting member 41 by the first hollow particles 52. The surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflecting member 41 is 40% or more.

[0012] The light-emitting device 100 mainly includes a plurality of light-emitting elements 1, a first substrate 10 on which the plurality of light-emitting elements 1 are placed, a second substrate 20 on which the first substrate 10 is placed, a first wire 31 and a second wire 32 which are the first 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 disposed on the first substrate 10 and contacts the covering member 40, a second reflecting member 42 that is disposed on the second substrate and contacts the covering member 40, a third reflecting member 7 that covers the side surface of the light-emitting element 1 on the first substrate 10, and a light-transmitting member 5 that covers the upper surface of the light-emitting element 1. Hereinafter, each component will be described.

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

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

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

[0016] (The second substrate) The second substrate 20 includes a flat base material and wiring disposed on at least the upper surface of the base material. The second substrate 20 has a substrate mounting area 23 on the upper surface for mounting the first substrate 10, and further includes a second terminal 120 on the upper surface outside the substrate mounting area 23. The substrate placement area 23 is an area where the first substrate 10 is placed via a joining member. This substrate placement area 23 is set as an area having the same area as the planar shape of the first substrate 10. If the first substrate 10 is rectangular in plan view, the substrate placement area 23 can also be rectangular. Here, the second terminal 120 includes a first wire connection terminal 21 connected to the first external connection terminal 11 via a wire and a second wire connection terminal 22 connected to the second external connection terminal 12 via a wire, and the first wire connection terminal 21 and the second wire connection terminal 22 are arranged on the second substrate 20 with the substrate placement area 23 therebetween.

[0017] A plurality of the first wire connection terminals 21 are arranged in a row along one long side of the rectangular substrate placement area 23 outside the substrate placement area 23. The first wire connection terminal 21 is a terminal to which the other end of a first wire 31 having one end connected to the first external connection terminal 11 is connected. A plurality of the second wire connection terminals 22 are arranged in a row along the other long side of the rectangular substrate placement area 23 (that is, the side located on the opposite side across the substrate placement area 23 from the aforementioned one long side) outside the substrate placement area 23. The second wire connection terminal 22 is a terminal to which the other end of a second wire 32 having one end connected to the second external connection terminal 12 is connected. Here, as an example, each of the first wire connection terminal 21 and the second wire connection terminal 22 is substantially rectangular, and they are spaced apart from each other and arranged in a single row along the long side of the substrate placement area 23.

[0018] The second terminal 120 can be formed, for example, by the same material and formation method as the wiring of the first substrate 10 already described. Here, as an example, the second substrate 20 includes a plurality of second drive terminals 16 for handling drive signals for turning on or off the light-emitting element 1 on its upper surface. The second drive terminals 16 are arranged, for example, on the upper surface inside (that is, on the substrate placement area 23 side) of the first wire connection terminal 21. A third wire 33 described later is connected to the second drive terminal 16.

[0019] The base material preferably uses a material with high heat dissipation, and more preferably, a material having high light-shielding properties and base material strength. Specifically, ceramics such as alumina, aluminum nitride, and mullite, resins such as phenolic resin, epoxy resin, polyimide resin, bismaleimide triazine resin, and polyphthalamide, and further, composite materials composed of resin and metal or ceramics, etc. may be mentioned. As the base material, a flat plate-like one can be used, or a base material having a cavity on the upper surface may be used. In this case, the second substrate 20 can place the first substrate 10 in the cavity with the bottom of the cavity as the substrate placement area. The second substrate 20 may be provided with wiring for placing the first substrate 10 on the surface of the substrate placement area 23. The first substrate 10 and the second substrate 20 can be joined via a joining 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 those metals. In particular, it is preferable to use gold, which is excellent in thermal resistance and the like. The diameter of the wire is, for example, 15 μm or more and 50 μm or less. Note that the wire 130 includes a first wire 31 and a second wire 32 connected to the first terminal 110 and the second terminal 120, and a third wire 33 for handling 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 can be formed of equivalent members only with different lengths. The wire 130 can be arranged so as to straddle the long side of the first substrate 10, which is substantially rectangular in plan view, and be substantially orthogonal to the long side, for example.

[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 surface side, and is flip-chip mounted on the first substrate 10 with the surface having the electrodes as the lower surface. In this case, the upper surface on the opposite side of the surface where the electrodes are disposed becomes the main light extraction surface of the light-emitting element 1. In the light-emitting device 100, the light-emitting elements 1 are arranged and mounted on the first substrate 10 at predetermined intervals in a matrix direction. The size and number of the light-emitting elements 1 to be used can be appropriately selected according to the form of the light-emitting device to be obtained. Among them, it is preferable to mount more of the smaller light-emitting elements 1 at a higher density. Thereby, the irradiation range can be controlled with a larger number of divisions, and it can be used as a light source for a high-resolution lighting system. For example, there is an example in which 1,000 to 20,000 light-emitting elements 1 having a rectangular shape in plan view with a side length of 40 to 100 μm are used and arranged in a matrix so as to form a rectangle as a whole.

[0022] The light-emitting element 1 can select an object of any wavelength. For example, as the blue or green light-emitting element 1, those using ZnSe or a nitride semiconductor (In X Al Y Ga 1-X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1), or GaP can be selected. Also, as the red light-emitting element 1, a semiconductor represented by GaAlAs or AlInGaP can be preferably used. Furthermore, semiconductor light-emitting elements made of materials other than these can also be used. The composition and emission color of the light-emitting element 1 to be used can be appropriately selected according to the purpose.

[0023] (Bonding member) As shown in FIG. 6, the light-emitting element 1 is joined to a wiring disposed in the element mounting region 13 of the first substrate 10 by a conductive joining member. 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, Al, etc. can be used as the joining member. Also, as the joining member, solders such as AuSn-based alloys and Sn-based lead-free solders may be used. In this case, the light-emitting element 1 can be joined to the first substrate 10 by the reflow method. Further, as the joining member, a conductive adhesive containing conductive particles in a resin can also be used. The joining between the light-emitting element 1 and the first substrate 10 may be formed using a plating method. Examples of the material include copper. Also, the joining between the light-emitting element 1 and the first substrate 10 may be such that the electrode of the light-emitting element 1 and the wiring of the first substrate 10 are directly joined without passing through a joining 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 space between the lower surface of the light-emitting element 1 and the first substrate 10. The third reflecting member 7 can reflect the light emitted from the side surface of the light-emitting element 1 and cause it to be emitted from the upper surface of the translucent member 5 which is the light-emitting surface of the light-emitting device 100. Therefore, the light extraction efficiency of the light-emitting device 100 can be increased. Also, when the light-emitting element 1 is individually lit, the boundary between the light-emitting area and the non-light-emitting area can be made clear. As a result, the contrast ratio between the light-emitting area and the non-light-emitting area is improved. Further, the third reflecting member 7 may be disposed at a distance from the first reflecting member 41, or may be disposed in contact with the first reflecting member 41.

[0025] Note that it is preferable to use a soft resin with relatively low elasticity and excellent shape followability for the third reflecting member 7. As the material of the third reflecting member 7, a resin material having good insulation properties, for example, a thermosetting resin such as an epoxy resin or a silicone resin can be preferably used. Further, it is preferable to use a white resin in which particles of a light-reflective substance are contained in the resin serving as the base for the third reflecting member 7. As the light-reflective substance, for example, titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, glass filler, etc. can be preferably used. Note that the third reflecting member 7 may contain a light-absorbing substance such as carbon black or graphite.

[0026] (Light-transmissive member) The light-transmissive member 5 has light-transmitting properties and covers the upper surfaces of the plurality of light-emitting elements 1. The light-transmissive member 5 covers the upper surfaces of the plurality of light-emitting elements 1 and the upper surface of the third reflecting member 7 collectively. The upper surface of the light-transmissive member 5 constitutes the light-emitting surface of the light-emitting device 100. The light-transmissive member 5 may contain a wavelength conversion member. Here, as an example, the light-transmissive member 5 contains a wavelength conversion member and wavelength-converts at least a part of the light emitted from the light-emitting element 1 and emits it to the outside. Examples of the wavelength conversion member include phosphors. The light-transmissive member 5 is substantially rectangular in plan view and is arranged so as to cover the upper surfaces of the plurality of light-emitting elements 1.

[0027] The light-transmissive member 5 may be arranged on the light-emitting element 1 in a form processed into a sheet shape or a plate shape, or may be applied in a layer on the light-emitting element 1 by means of a spray or the like. Alternatively, it may be formed by injection molding using a mold or the like, a transfer molding method, compression molding, or the like. Examples of the light-transmissive member containing the wavelength conversion member include a sintered body of a phosphor, and a material in which phosphor powder is contained in a base material such as a resin, glass, or other inorganic substance. As the base material, a light-transmissive material such as an epoxy resin, a silicone resin, a resin obtained by mixing these, or glass can be used. The thickness of the light-transmissive member 5 can be, for example, about 20 μm or more and 100 μm or less. Note that the light-transmissive member 5 is formed to have a size that covers the entire upper surface of the plurality of light-emitting elements 1. Further, the light-transmissive member 5 is provided so as to extend to a position where it abuts on a first reflecting member 41 described later here.

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

[0029] (Coating member) The covering member 40 is a light-shielding resin that covers the wire 130 (specifically, the first wire 31 and the second wire 32) outside the element mounting area 13. Note that, as an example, the covering member 40 is arranged in a frame shape in plan view so as to cover the first wire 31 and the second wire 32 and surround the element mounting area 13. The covering member 40 is arranged to be in contact with a first reflecting member 41 described later. Note that 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] In addition, the covering member 40 arranged in a frame shape has a wider width on the long side of the rectangular first substrate 10 in plan view than in the short-side region. Further, the covering member 40 is arranged such that the height of the covering member 40 (that is, the distance from the upper surface of the second substrate 20 to the upper surface of the covering member 40) is the highest 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 such that the top 40a of the covering member 40 overlaps with the top 130a of the wire 130. Note that the position of the top 40a of the covering member 40 is arranged to be above the top 41a of the first reflecting member 41 described later.

[0031] Examples of the light-shielding covering member 40 include resins containing a light-shielding filler. As the base resin, for example, silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, etc. can be used. Examples of the light-shielding 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. Specifically, white resins excellent in light reflectivity, black resins excellent in light absorption, and gray resins having both light reflectivity and light absorption can be mentioned. Also, the covering member 40 may have a plurality of these resin layers laminated. Among them, in consideration of the 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 Reflective Member, Second Reflective Member) The light-emitting device 100 has a first reflective member 41 disposed along the element mounting region 13 and in contact with the covering member 40 on the first substrate 10 between the element mounting region 13 and the first terminal 110. Further, the light-emitting device 100 has a second reflective member 42 disposed outside the second terminal 120 and in contact with the covering member 40 on the upper surface of the second substrate 20. That is, the covering member 40 is disposed between the first reflective member 41 and the second reflective member 42 across 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 reflective member 41 disposed so as to surround the element mounting region 13 on the first substrate 10 and a second reflective member 42 disposed so as to surround the substrate mounting region 23 on the second substrate 20. Such an arrangement of the covering member 40 can be formed by supplying uncured resin that constitutes the covering member 40 into the frame surrounded by the first reflective member 41 and the second reflective member 42. In other words, the first reflective member 41 and the second reflective member 42 can be used as dams for blocking the flow of the uncured resin when the covering member 40 is supplied.

[0033] The first reflective member 41 and the second reflective member 42 can be set to a predetermined height by providing a plurality of them to overlap in the height direction. For example, the first reflective member 41 and the second reflective member 42 are arranged in a single layer on the substrate with resin adjusted to a predetermined viscosity from a nozzle, and this operation is repeated to achieve a predetermined height.

[0034] The height of the first reflective member 41 from the upper surface of the first substrate 10 may be the same as or different from the height of the second reflective member 42 from the upper surface of the second substrate 20. When they are different, it is preferable to make the second reflective member 42 higher than the first reflective member 41. In this case, the difference between the height from the upper surface of the second substrate 20 to the top of the first reflective member 41 and the height from the upper surface of the second substrate 20 to the top of the second reflective member 42 can be made smaller than the thickness of the first substrate 10 (that is, the distance from the upper surface to the lower surface of the first substrate 10). Thereby, when the covering member 40 is disposed between the first reflective member 41 and the second reflective member 42, it is possible to suppress the uncured covering member 40 from overflowing outside the second reflective member 42.

[0035] The first reflective member 41 is arranged in a rectangular frame shape surrounding the element placement region 13 in a plan view. As an example, the covering member 40 is arranged so as to contact the top of the first reflective member 41. The first reflective member 41 is arranged on the first substrate 10 along the outer periphery of the element placement region 13 in a rectangular frame shape in a plan view. In the position along the longitudinal direction of the element placement region 13, the first reflective member 41 is disposed between the side in the longitudinal direction of the element placement region 13 and the plurality of first terminals 110. In the position along the short side direction of the element placement region 13, the first reflective member 41 is disposed on the first substrate 10 between the element placement region 13 and the outer edge of the first substrate 10.

[0036] Note that the first reflective member 41 preferably has an inclined surface that inclines from the first substrate 10 side toward the top of the first reflective member 41. The inclined surface is preferably a convex curved surface on the outside. Specifically, the first reflective member 41 is preferably substantially semi-circular or substantially semi-elliptical in a cross-sectional view perpendicular to the first surface 10a of the first substrate 10. Thereby, the surface of the covering member 40 that contacts the first reflective member 41 can be a convex curved surface on the covering member 40 side. Since the covering member 40 has such a shape, the light emitted from the light-transmitting member 5, transmitted through the first reflective member 41, and directed toward the covering member 40 can be reflected toward the first substrate 10 side. Thereby, unintended leakage light and stray light are suppressed from going upward (the light extraction side), so that a light-emitting device with suppressed light scattering can be obtained.

[0037] In addition, the substantially semi-circular shape in this embodiment does not refer only to a semi-circle in the strict sense of dividing a perfect circle into two equal parts, but includes a shape that can be visually recognized as being close to a semi-circle. For example, a circle distorted or deformed within the range of tolerances and errors may be regarded as a semi-circle. Specifically, it includes those in which a circle with a tolerance or error value within 5% of the length of the diameter is regarded as a semi-circle. When the value exceeds 5% of the length of the diameter, it is regarded as a substantially elliptical shape. Note that the semi-circle does not have to be an exact bisect. In addition, the substantially semi-elliptical shape in this embodiment does not refer only to the case of bisecting an elliptical shape in the strict sense, which is the locus of points where the sum of the distances from two fixed points on a plane is constant, but includes a shape that can be visually recognized as being close to a semi-ellipse. For example, it may be a shape obtained by bisecting an oval shape, a oval coin shape, or a track shape for track and field events obtained by stretching a circle in one direction. That is, it may be a shape obtained by bisecting a substantially elliptical shape. The substantially elliptical shape also includes a shape surrounded by a pair of straight lines or curves extending along the longitudinal direction or the short transverse direction, and a pair of curves connected to the pair of straight lines or curves and convexly curved outward. For example, a shape in which the same-side ends of two parallel sides facing each other or two curved sides facing each other are connected by circular arcs of the same diameter (for example, the arcs of a semi-circle) can be cited. Note that the semi-ellipse does not have to be an exact bisect.

[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 surface of the first reflecting member 41 has irregularities formed by the first hollow particles 52. 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, the light from the light-emitting element 1 hitting the first reflecting member 41, the reflected light inside the device, and the external light are diffusely reflected, and the generation of stray light is suppressed. Thereby, a desired irradiation pattern can be obtained. On the other hand, if the surface roughness Ra of the first reflecting member 41 is 3.0 μm or less, it becomes easy 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, generation of stray light is more 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. Note that the range of the surface roughness Ra was determined with reference to a graph showing the relationship between the surface roughness Ra and the matting shown in FIG. 9.

[0040] The surface roughness Ra of the first reflecting member 41 can be, for example, a value measured at a speed of 200 μm / s for 2000 μm using a stylus type step thickness meter (Alpha-Step-IQ manufactured by KLA Tencor). In the light emitting device 100, a part 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 surface of the first hollow particles 52 may be covered with the first resin 51. Further, in FIG. 8, the first hollow particles 52 are described as being adjacent to each other, but the first resin 51 may be interposed between the first hollow particles 52. Furthermore, the first hollow particles 52 may be a mixture of a state where adjacent ones are interposed with the first resin 51 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, the light transmitted through the first reflecting member 41 may be reflected by the first substrate 10 or the like, and stray light may be generated. Also, the inside of the first reflecting member 41 becomes visible through, and the appearance deteriorates. If the reflectance of the first reflecting member 41 is 40% or more, the reflectance of the first reflecting member 41 becomes excellent, and the above-described problems can be suppressed. The reflectance in this specification is based on the emission peak wavelength of the light emitting element, but may be based on light of 450 nm.

[0042] The reflectivity of the first reflecting member 41 is preferably 60% or more. If the reflectivity of the first reflecting member 41 is 60% or more, the first reflecting member 41 with more excellent reflectivity can be obtained. There is no particular limitation on the upper limit of the reflectivity of the first reflecting member 41, but for example, it may be 80% or less, or 90% or less. However, the reflectivity of the first reflecting member 41 is more preferably 95% or more.

[0043] By containing a plurality of first hollow particles 52, the first reflecting member 41 can maintain white as an appearance due to the effect of the refractive index difference between the outer shell of the first hollow particles 52 and the cavity inside the first hollow particles 52, and can further maintain a high level in terms of reflectivity.

[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 viewpoints of heat resistance, light resistance, etc., the plurality of first hollow particles 52 are preferably hollow silica or hollow glass.

[0045] The plurality of first hollow particles 52 preferably have a median diameter of 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 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 the first hollow particles 52 contained in the first resin 51 increases, and it becomes easier to control the reflectivity of the first reflecting member 41. From the viewpoint of easily controlling the surface roughness Ra of the first reflecting member 41, the median diameter is more preferably 20 μm or more, and still more preferably 30 μm or more. Also, from the viewpoint of easily controlling the reflectivity of the first reflecting member 41, the median diameter is more preferably 60 μm or less, and still more preferably 40 μm or less.

[0046] The median diameter refers to the particle diameter (volume median diameter) at which the volume cumulative frequency from the smaller diameter side in the volume-based particle size distribution by the laser diffraction scattering method reaches 50%. For the laser diffraction scattering method of measuring particle size distribution, it can be measured using, for example, a laser diffraction particle size distribution measuring 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 with respect 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 with respect 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 it becomes easier to control the surface roughness Ra of the first reflecting member 41. On the other hand, if it is 70 parts or less, it becomes easier to adjust the viscosity of the first resin 51, and it becomes easier 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 with respect to 100 parts by mass of the first resin 51. If it is 50 parts or less, it becomes easier to adjust the viscosity of the first resin 51. Also, from the viewpoint of making it easier to control the surface roughness Ra of the first reflecting member 41, it is more preferably 30 parts or more. Note that "parts" corresponds to the mass (g) of the additive with respect to 100 g of the resin base material. That is, the parts of the first hollow particles with respect to 100 parts by mass of the first resin is, in other words, the parts by mass of the first hollow particles with respect to 100 parts by mass of the first resin.

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

[0049] It is preferable to use the first resin 51 having a higher viscosity than the resin constituting the coating member 40. The viscosity of the first resin 51 can be adjusted, for example, by the amount of the 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 reflective member 41 into a desired shape. On the other hand, if it is 1200 Pa·s or less, the resin can be discharged from the discharge device quickly, and workability is improved. From the viewpoint of making it easier to form the first reflective member 41 into a 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. Also, from the viewpoint of facilitating the discharge of 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] In order to increase the viscosity and impart thixotropy to the first resin 51, nanofillers such as Aerosil (registered trademark) may be added. In the present embodiment, the first resin 51 contains a nanofiller 53. Examples of the nanofiller 53 include nanosilica. Also, when a large amount of the nanofiller 53 is filled and the viscosity becomes too high, a solvent can be added to lower the viscosity. The solvent that can be used is preferably compatible with the base resin. For example, when a silicone resin is used as the base material, aromatic hydrocarbons (xylene, toluene, etc.), petroleum hydrocarbons (benzine, petroleum ether, etc.), ethers (diethyl ether, THF, etc.) can be used.

[0051] In the first reflective member 41, a plurality of first hollow particles 52 are dispersed in the first resin 51. By dispersing a plurality of first hollow particles 52 in the first resin 51, the reflectivity of the first reflective member 41 is improved. In the present embodiment, the fact that a plurality of first hollow particles 52 are dispersed in the first resin 51 means that when a predetermined location in the cross-section of the first reflective member 41 is observed, at two locations with the same area, in any location, the difference in the ratio of the first hollow particles 52 is less than 1.5 times. The calculation of the ratio (abundance) of the first hollow particles 52 can be specifically performed as follows. First, a cross-sectional image of the first reflecting member 41 is taken, and the abundance ratio of the first hollow particles 52 is calculated at any two locations. The two images are taken at the same magnification, and the abundance ratio of the first hollow particles 52 is calculated as "the area of the first hollow particles 52 ÷ the area of the resin portion" in the cross-sectional image. Each area 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 obtained by cutting out the printed paper. Note that the area of the resin portion is the portion excluding the portions other than the resin portion of the substrate or the like shown in the photograph.

[0052] It is preferable that the angle formed by the first surface 10a of the first substrate 10 and the first reflecting member 41 is 60 degrees or more and 135 degrees or less. If the angle is within this range, it is easy to form the first reflecting member 41, and the function of the first reflecting member 41 is further improved. As shown in FIG. 10, the angle formed by the first surface 10a of the first substrate 10 and the first reflecting member 41 can be calculated by taking a cross-section of the first reflecting member 41 with a microscope (VHX-700F manufactured by KEYENCE CORPORATION) and measuring the angle θ between the first surface 10a of the first substrate 10 and the outer peripheral portion of the first reflecting member 41 using the measurement function.

[0053] The second reflecting member 42 is disposed below the light-emitting element 1 and the translucent member 5 (that is, on the side opposite to the light extraction side) in the light-emitting device 100. Therefore, the second reflecting member 42 may or may not have translucency with respect to the light emitted from the light-emitting element 1. In the manufacturing process, the second reflecting member 42 can be used as a dam for blocking the uncured coating member 40, similarly to the first reflecting member 41. For this reason, it is preferably disposed in the same process as or in a continuous process with the first reflecting member 41, and from the viewpoint of simplifying the manufacturing method, it is preferable to use 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 also have a reflectance of 40% or more, similar to the first reflecting member 41. Other configurations may also be the same as 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 irradiated from the light source to the outside through a lens. The light-emitting device 100 turns on the light-emitting element 1 by an external power switch. Note that the light-emitting device 100 is configured to be able to individually drive some or all of the light-emitting elements 1 set in advance.

[0056] As a light-emitting device, for example, a device capable of varying the light distribution of a vehicle headlight has been developed. Specifically, examples include those in which a plurality of LEDs are arranged, and those using an LED (multi-chip type) on which a plurality of light-emitting elements are mounted and can be individually lit. The light emitted from these LEDs is irradiated forward through the lens of the lamp unit. However, for fine light distribution control, the directivity of light is becoming more important. As a method for manufacturing a light-emitting device, a method is known in which a frame is formed around a light-emitting element with a light-reflective resin, and the inside is filled with a low-viscosity light-reflective resin. However, in this method, stray light may be generated when the light diffusely reflected inside the lamp unit of a headlight or lighting device is reflected by the light-reflective resin portion. Then, when the stray light exits through the lens, an unintended irradiation pattern is formed. As a countermeasure against stray light, it is conceivable to blacken the resin portion to absorb extra light. However, in this case, the output of the LED is reduced. In addition, when sunlight enters the lamp unit, the light may be absorbed, and there is a risk that the black resin portion will burn out. The same concern also exists when a filler that absorbs short-wavelength light, such as titanium oxide, is added. Regarding external light reflection on the light-emitting surface and the sealing surface, it is conceivable to take measures by providing irregularities on the outermost surface, but there was no method for dealing with the resin frame portion.

[0057] In contrast, in the light-emitting device 100 of the present embodiment, the first hollow particles 52 are used to form irregularities on the surface of the first reflecting member 41. Since the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less, the light hitting the first reflecting member 41 is diffusely reflected, and the generation of stray light is suppressed. As a result, a desired irradiation pattern can be obtained, and when used in combination with a lens, the optical design of the lens can be easily performed. Further, since the first reflecting member 41 contains a plurality of first hollow particles 52, the reflectance of the first reflecting member 41 can be set to 40% or more. Thereby, the reflectance of the first reflecting member 41 becomes excellent.

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

[0059] The method for manufacturing the light-emitting device 100 includes a step of preparing an intermediate body having a substrate 10 having a first surface 10a and one or more light-emitting elements 1 disposed on the first surface 10a of the substrate 10, and a mixture obtained by mixing a first resin 51 and a plurality of first hollow particles 52, a step of applying the mixture to the first surface 10a of the substrate 10 so as to surround the light-emitting element 1, and a step of curing the mixture to form the first reflecting member 41. After the step of forming the first reflecting member 41, irregularities are formed on the surface of the first reflecting member 41 by the first hollow particles 52. After the step of forming the first reflecting member 41, the surface roughness Ra of the first reflecting member 41 is 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflecting member 41 is 40% or more.

[0060] Also, in the step of preparing, a solvent may be further mixed into the mixture, and in the step of forming the first reflective member 41, the solvent in the mixture may be volatilized and the mixture may be cured. In this embodiment, the case where a solvent is mixed into the mixture will be described.

[0061] Specifically, the manufacturing method of the light-emitting device 100 includes an intermediate and mixture preparation step S101, a first reflective member arrangement step S102, a second reflective member arrangement step S103, and a covering member arrangement step S104. The intermediate and mixture preparation step S101 includes an element placement step S11, a third reflective member arrangement step S12, a substrate placement step S13, a wire connection step S14, a light-transmissive member arrangement step S15, and a mixture preparation step S16. The first reflective member arrangement step S102 includes a mixture coating step S17 and a first reflective member formation step S18. Hereinafter, each step will be described. Note that, regarding the material, arrangement, etc. of each member, since they are as described in the description of the above-described light-emitting device 100, the description will be omitted here as appropriate.

[0062] The element placement step S11 is a step of placing a plurality of light-emitting elements 1 on the element placement region 13 of the first substrate 10 (see FIGS. 12A and 12B). In the element placement step S11, a plurality of light-emitting elements 1 arranged on a support substrate at a predetermined interval are prepared, and after the plurality of light-emitting elements 1 are attached to the element placement region 13 of the first substrate 10, the support substrate is peeled off. Note that, before performing the element placement step S11, it is preferable to prepare the first substrate 10 on which wirings such as the first terminal 110 are previously arranged. The first terminal 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 such as Cu, or the like. Further, the wiring electrically connected to the light-emitting element 1 in the element placement region 13 can be patterned by an etching method, a printing method, or the like. Note that the first substrate 10 may be prepared by purchase or the like. The light-emitting element 1 can be electrically connected to the element placement region 13 on the first substrate 10, for example, by a plating method.

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

[0064] The substrate mounting step S13 is a step of mounting the first substrate 10 on the substrate mounting region 23 of the second substrate 20 (see FIGS. 12D and 12E). Here, the first substrate 10 on which the light emitting element 1 is mounted is arranged on the substrate mounting region 23 of the second substrate 20 and joined via a bonding material such as a sintered metal, for example, sintered Ag, sintered Cu, etc. It is preferable to prepare the second substrate 20 on which wirings such as the second terminals 120 are arranged in advance before performing the substrate mounting step S13.

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

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

[0067] The mixture preparation step S16 is a step of preparing a mixture by mixing the first resin 51 and a plurality of first hollow particles 52. Here, further, a solvent and a nanofiller 53 are mixed. By mixing the solvent, it becomes easier to mix each member. Also, by mixing the nanofiller 53, it becomes easier to adjust the viscosity of the mixture. The amounts of the respective members are appropriately adjusted so that the first reflective member 41 has a desired configuration. The preparation of the mixture is performed, for example, by putting each member into a dedicated stirring container, manually mixing with a spatula, and then stirring using a stirrer.

[0068] In the step of preparation, the content of the solvent in the mixture is preferably 1 part or more and 30 parts or less with respect to 100 parts by mass of the first resin 51. If it is 1 part or more with respect to 100 parts by mass of the first resin 51, it becomes easier to mix each member. On the other hand, if it is 30 parts or less, it becomes easier to volatilize the solvent when curing the mixture, and it becomes easier to form irregularities on the surface of the first reflective member 41. Note that the mixture preparation step S16 may be performed before the light-transmissive member arrangement step S15. That is, the mixture may be prepared in advance and stirred again immediately before applying the mixture in the mixture application step S17.

[0069] The first reflective member arrangement step S102 is a step of arranging the first reflective member 41 along the element placement region 13 between the upper surface of the first substrate 10 and the first terminal 110 in the element placement region 13 (see FIG. 12H). The first reflective member arrangement step S102 includes a mixture application step S17 and a first reflective 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, while supplying the uncured mixture for forming the first reflecting member 41 from the nozzle of the dispenser, the nozzle is moved along the element placement 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, after manually stirring the mixture, for example, it is preferably stirred at 1000 rpm or more for 1 minute or more and then the application is started within 30 minutes.

[0071] The first reflecting member forming step S18 is a step of curing the mixture to form the first reflecting member 41. The curing of the mixture is performed, for example, under the conditions of 140°C or more and 160°C or less for 2 hours or more and 6 hours or less. In the first reflecting member forming step S18, when the mixture is cured, the amount of the mixture decreases due to the volatilization of the solvent, the first hollow particles 52 are arranged on the surface of the first reflecting member 41, and irregularities are formed on the surface of the first reflecting member 41.

[0072] After the step of forming the first reflecting member 41, irregularities are formed on the surface of the first reflecting member 41 by the first hollow particles 52, 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. Further, 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. Also, after the step of forming the first reflecting member 41, the angle formed by 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 in the description of the above-described light-emitting device 100.

[0073] The second reflecting member arranging step S103 is a step of arranging the second reflecting member 42 outside the second terminal 120 on the upper surface of the second substrate 20 (see FIG. 12H). It is preferable that the first reflecting member 41 and the second reflecting member 42 are made of the same material, so that the first reflecting member arranging step S102 and the second reflecting member arranging step S103 can be performed as the same step. In addition, in the first reflecting member arranging step S102 and the second reflecting member arranging step S103, first, the second reflecting member 42 may be arranged by the second reflecting member arranging step S103, and then the first reflecting member 41 may be arranged by the first reflecting member arranging step S102. Further, 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 arranging step S104 is a step of arranging a light-shielding covering member 40 that contacts the first reflecting member 41 and covers the wire 130 outside the first reflecting member 41. Specifically, it is a step of arranging a light-shielding covering member 40 made of a resin having a lower viscosity than the first reflecting member 41 and the second reflecting member 42 between 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 surface of the first substrate 10.

[0075] As described above, the embodiments for carrying out the invention have been specifically described. However, the gist of the present invention is not limited to these descriptions and should be broadly interpreted based on the descriptions in the claims. Also, various changes and modifications based on these descriptions are included in the gist of the present invention. Hereinafter, modified examples will be described. Note that since the materials and arrangements of the respective members are as described in the description of the embodiment, the description will be omitted here as appropriate.

[0076] 《Modified Example》 Figs. 13A to 13D are enlarged cross-sectional views schematically showing a part of the first reflecting member in the first to fourth modified examples of the embodiment, respectively. Fig. 14 is a cross-sectional view schematically showing the 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 part of the sealing member in the fifth modified example of the embodiment. Note that Fig. 16 schematically shows the part of the symbol B in Fig. 15. In addition, the components already described are denoted by the same reference numerals and the description is omitted, or the description is omitted in order not to repeat the same description.

[0077] A plurality of first hollow particles 52 can also be used by combining a plurality of first hollow particles having different particle sizes. In addition, one or more of oxide particles containing Ti, Zn, Zr, Al, Si, etc., non-hollow spherical particles, and particles having a refractive index different from that of the first resin 51 of the base material such as AlN and MgF can be used in combination with the first hollow particles 52. Since the amount of light reflected and transmitted differs depending on the content concentration and density of these particles, the addition amount and density are adjusted according to the shape and size of the light-emitting device. In addition, the first reflecting member may contain other particles as fillers or the like. The mixing ratio of each particle contained in the first reflecting member is adjusted so as to obtain a desired surface roughness Ra and reflectance. Specifically, the first reflecting member may have a configuration as shown in Figs. 13A to 13C.

[0078] [First Modified Example] As shown in Fig. 13A, the first reflecting member 41A contains first hollow particles 52a having a large median diameter and first hollow particles 52b having a small median diameter. Even with such a configuration, the reflectance of the first reflecting member 41A can be increased and the generation of stray light can be suppressed.

[0079] [Second Modified Example, Third Modified Example] As shown in Fig. 13B, the first reflecting member 41B contains oxide particles 54. As shown in Fig. 13C, the first reflecting member 41C contains non-hollow spherical particles 55. Examples of the spherical particles 55 include silica and glass. Since the oxide particles 54 and the spherical particles 55 have a smaller median diameter than the first hollow particles 52, they enter the gaps between the first hollow particles 52. According to these configurations, it is possible to improve the reflectance. Note that a part of the oxide particles 54 and the spherical particles 55 is 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 Example] As shown in FIG. 13D, in the first reflection member 41D, the first hollow particles 52 are not exposed from the first resin 51, and the surface of the first hollow particles 52 is covered with the first resin 51. According to such a configuration, for example, when manufacturing a light-emitting device, even when the first hollow particles 52 are not exposed from the first resin 51 due to factors such as the amount of solvent mixed in the mixture and the amount of solvent to be volatilized, it is possible to increase the reflectance of the first reflection member 41D and suppress the generation of stray light.

[0081] [Fifth Modification Example] The light-emitting device 100A has a light-emitting element 1A mounted face-up on a substrate 10. In the light-emitting element 1A, positive and negative electrodes disposed on the surface of a semiconductor laminate are electrically connected to the first substrate 10 via element wires 34. The light-emitting device 100A has a sealing member 60 that further covers the light-emitting element 1A on the first surface 10a of the substrate 10. The sealing member 60 includes 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 the second resin 61. The second hollow particles 62 are preferably unevenly distributed on the surface side of the sealing member 60. By the uneven distribution of the second hollow particles 62 on the surface side of the sealing member 60, unevenness can be formed on the surface of the sealing member 60. Thereby, the glare of the sealing member 60 due to external light can be suppressed. 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, the glare of the sealing member 60 is more suppressed. On the other hand, if it is 3.0 μm or less, it becomes easier to form unevenness on the surface of the sealing member 60.

[0083] The uneven distribution of the second hollow particles 62 on the surface side of the sealing member 60 means that when observing a predetermined location in a cross-section in a direction perpendicular to the first surface 10a of the first substrate 10 in the sealing member 60, the ratio of the second hollow particles 62 existing on the surface side and the ratio of the second hollow particles 62 existing on the bottom side are different by 1.5 times or more. The calculation of the ratio (existence rate) of the second hollow particles 62 can be specifically performed as follows. First, a cross-sectional image of the sealing member 60 is taken, and the existence rate of the second hollow particles 62 is calculated in the image on the surface side including the surface and the image on the bottom side including the bottom. The images on the surface side and the bottom side have the same magnification, and the existence rate of the second hollow particles 62 is calculated by "the area of the second hollow particles 62 ÷ the area of the resin portion" in the cross-sectional image. Each area may be calculated by the measurement function of the electron microscope from the cross-sectional image taken by the electron microscope (JSM-IT200 manufactured by JEOL Ltd.), or may be calculated from the mass obtained by cutting out the printed paper. Note that the area of the resin portion is the portion excluding the portions other than the resin portion of the substrate or the like shown in the photograph.

[0084] In the light-emitting device 100A, a part 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 surface of the second hollow particles 62 may be covered with the second resin 61. Further, in FIG. 16, the second hollow particles 62 are described as being adjacent to each other, but the second resin 61 may be interposed between the second hollow particles 62. Furthermore, the second hollow particles 62 may be a mixture of a state where adjacent ones and the second resin 61 are 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 still more preferably, it is 30 μm or more. Also, more preferably, it is 60 μm or less, and still more preferably, it is 40 μm or less. Further, the plurality of second hollow particles 62 are preferably hollow silica or hollow glass. These are 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 the nanofiller 53. Further, the plurality of second hollow particles 62 can be used in combination of a plurality of second hollow particles having different particle sizes. Also, similar to the first reflective member, one or more of the oxide particles 54, non-hollow spherical particles 55, and particles having a refractive index different from that of the base second resin 61 can be used in combination with the second hollow particles 62. Further, the sealing member 60 may contain other particles as fillers or the like. Furthermore, the sealing member 60 may contain a wavelength conversion member. Examples of the wavelength conversion member include phosphors. Examples of the phosphor include those exemplified by the light-transmitting member 5 of the light-emitting device 100.

[0086] The manufacturing method of the light-emitting device 100A may include a step of disposing the light-emitting element 1A on the first surface 10a of the first substrate 10, connecting the element wire 34, forming the first reflective member 41, and then disposing the sealing member 60 within the frame of the first reflective member 41. In the step of disposing the sealing member 60, for example, the second resin 61 mixed with the second hollow particles 62 is disposed within the frame by potting, spraying, or the like. Then, for example, the second resin 61 is cured at a temperature of 120°C or higher and 200°C or lower to form the sealing member 60. 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] In addition, although the light-emitting device is assumed to have a plurality of light-emitting elements, the light-emitting device may have only one light-emitting element. Further, a light-emitting device that does not include the second reflective member and the covering member may also be used. The manufacturing method of the light-emitting device may include other steps during or before and after the above-described steps, as long as it does not adversely affect the above-described steps. For example, it may include a foreign matter removing step of removing foreign matter mixed during manufacturing. Also, within a possible range, the steps may be rearranged. Further, in the mixture preparation step, a solvent may not be mixed.

Example

[0088] Hereinafter, examples will be described. No.A1 to A9 are examples that satisfy the configuration of the embodiment, and No.B1 to B3 are comparative examples that do not satisfy the configuration of the embodiment.

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

[0090] (Measuring resin viscosity) 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 material) A frame made by stacking two 0.18 μm fluororesin tapes was attached onto a glass slide, and the stirred resin was poured inside the frame, and the thickness was adjusted to the maximum using a squeegee, and curing was performed at 150 ° C / 4 hr. The transmittance of the cured sample was measured by setting it so that light enters from the resin surface in a spectrophotometer (U-3900 made by Hitachi High-Tech Science Co., Ltd.), and the value at 470 nm of the obtained transmission spectrum was taken as the transmittance. For the reflectance, a spectrophotometer (CMS-35SP made by Murakami Color Research Institute Co., Ltd.) was set so that light hits the resin surface, and the reflection spectrum was measured under conditions including regular reflection light. The value at 470 nm of the obtained reflection spectrum was taken as the reflectance.

[0092] (Measurement of surface roughness Ra of cured product) The stirred resin was placed in a syringe equipped with a needle with an inner diameter of 0.66 mm, and discharged in a line shape onto an alumina ceramic substrate using a dispenser (ML-5000XII manufactured by Musashi Engineering Co., Ltd.), and cured 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 thickness gauge (Alpha-Step-IQ manufactured by KLA Tencor Corporation), and the value measured was taken as the surface roughness Ra.

[0093] (Measurement of the Angle Formed by the Substrate and the Cured Product) The resin cured on the above-mentioned ceramic substrate was cut out with a cutter knife, and the cross-section was photographed with a microscope (VHX-700F manufactured by Keyence Corporation), and the angle between the surface in contact with the substrate and the outer peripheral portion of the cured product was calculated using the measurement function.

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

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

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

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

[0098] [No.A6] To 10 g of the base resin OE-6351, 10 parts of nanosilica (RX200), 40 parts of hollow glass with a median diameter of 40 μm (Glass Bubbles S38), 10 parts of non-hollow spherical silica with a median diameter of 0.5 μm (Admatechs Co., Ltd.'s Admafin SO-C2), and 5 parts of toluene as a solvent were added, and the mixture was stirred well and then applied and cured on a ceramic substrate. The preparation, curing, measurement of the resin viscosity, and measurement of the cured product were carried out in the same manner as in No. A1.

[0099] [No.A7] To 10 g of the base resin OE-6351, 10 parts of nanosilica (RX200), 40 parts of hollow glass with a median diameter of 40 μm (Glass Bubbles S38), 10 parts of titanium oxide with a median diameter of 0.5 μm (R-960 manufactured by Kemers Co., Ltd.), and 5 parts of toluene as a solvent were added, and the mixture was stirred well and then applied and cured on a ceramic substrate. The preparation, curing, measurement of the resin viscosity, and measurement of the cured product were carried out in the same manner as in No. A1.

[0100] [No.A8] To 10 g of the base resin OE-6351, 10 parts of nanosilica (RX200), 25 parts of hollow glass with a median diameter of 16 μm (Glass Bubbles iM30K), 25 parts of hollow glass with a median diameter of 40 μm (Glass Bubbles S38), 10 parts of alumina with a median diameter of 0.8 μm (Sumitomo Chemical Co., Ltd.'s Sumikolandum AA-03), and 3 parts of toluene as a solvent were added, and the mixture was stirred well and then applied and cured on a ceramic substrate. The preparation, curing, measurement of the resin viscosity, and measurement of the cured product were carried out in the same manner as in No. A1.

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

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

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

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

[0105] These results are shown in Table 1. In Table 1, those for which measurement could not be performed are indicated by "-".

[0106]

Table 1

[0107] As shown in Table 1, for No.A1 to A9 which satisfy the configuration of the embodiment, the reflectance of the cured product and the surface roughness of the cured product resulted in good results. Specifically, the following results were obtained. No.A1 had a solvent added, and compared with No.A2 which had no solvent added, the surface roughness Ra was larger. For No.A3 and No.A4, the median diameter of the hollow glass was larger than that of No.A1, and compared with No.A1, the surface roughness Ra was larger. However, the reflectance decreased slightly. For No.A4, the median diameter of the hollow glass was larger than that of No.A3, and compared with No.A3, the surface roughness Ra was larger. However, the reflectance decreased slightly. Also, for No.A4, the addition amount of the hollow glass was more than that of No.A9, and compared with No.A9, the surface roughness Ra was larger and the reflectance was higher.

[0108] No.A5 used two types of hollow glass with different median diameters in combination, and compared with No.A4, the reflectance was higher. However, the surface roughness Ra became slightly smaller. No.A6 used a combination of hollow glass and non-hollow spherical silica, and compared with No.A3, the surface roughness Ra was larger. However, the reflectance decreased slightly. No.A7 changed the spherical silica of No.A6 to titanium oxide with the same median diameter, and compared with No.A6, the reflectance was higher. No.A7 had the best balance between reflectance and surface roughness Ra. No.A8 used a combination of two types of hollow glass with different median diameters and non-hollow alumina, and compared with No.A5, the reflectance was higher.

[0109] On the other hand, for No.B1 to B3 which do not satisfy the configuration of the embodiment, the following results were obtained. Since No.B1 used titanium oxide without using hollow particles, although the reflectance was high, the surface roughness Ra was small. Since No.B2 used non-hollow spherical silica without using hollow particles, although the surface roughness Ra was large, the reflectance was low. Since the addition amount of the hollow glass in No.B3 was small, the viscosity of the resin became low, and a cured product with a desired shape could not be formed. Therefore, the angle formed by the cured resin and the substrate was also very small.

Industrial Applicability

[0110] The light-emitting device according to the embodiment of the present disclosure can be used for various light sources such as vehicle headlights and projectors.

Explanation of Signs

[0111] 1,1A Light-emitting element 5 Translucent member 7 Third reflecting member 10 First substrate (substrate) 10a First surface of the first substrate (substrate) 110 First 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 substrate 120 Second terminal 21 First wire connection terminal 22 Second wire connection terminal 23 Substrate mounting area 130 Wire 130a Top of the wire 31 First wire 32 Second wire 33 Third wire 34 Element wire 40 Coating member 40a Top of the coating member 41a Top of the first reflecting member 41,41A,41B,41C,41D First reflecting member 42 Second reflecting member 51 First resin 52 First hollow particles 52a First hollow particles with a large median diameter The first hollow particle with a small median diameter of 52b 53 Nanofiller 54 Oxide particle 55 Spherical particle 60 Sealing member 61 Second resin 62 Second hollow particle 100, 100A Light-emitting device

Claims

1. A substrate having a first surface, One or more light-emitting elements disposed on the 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 has a first resin and a plurality of first hollow particles contained in the first resin, The content of the plurality of first hollow particles is 20 parts or more and 50 parts or less with respect to 100 of the mass of the first resin, Unevenness is formed on the surface of the first reflecting member by the first hollow particles, A light-emitting device in which 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. The light-emitting device according to claim 1, wherein the surface roughness Ra of the first reflecting member is 0.50 μm or more and 2.0 μm or less.

3. The first reflecting member is substantially semi-circular or substantially semi-elliptical in a cross-sectional view perpendicular to the first surface of the substrate, The substantially semi-circular shape is obtained by bisecting a perfect circle, or a circle that is distorted or deformed within a tolerance or error range of 5% or less with respect to the length of the diameter and is regarded as a semi-circle, The substantially semi-elliptical shape is obtained by bisecting an elliptical shape which is the locus of points where the sum of the distances from two fixed points on a plane is constant, an oval shape obtained by extending a circle in one direction, a oval shape, or a shape obtained by bisecting a track shape for land racing, a pair of straight lines or curves extending along the longitudinal direction or the short transverse direction, and a pair of curves connected to the pair of straight lines or curves and curved convexly outward, or a shape obtained by bisecting a shape in which the same-side ends of two mutually opposing parallel sides or two mutually opposing curved sides are connected by arcs of the same diameter respectively. The light-emitting device according to claim 1 or claim 2.

4. The light-emitting device according to any one of claims 1 to 3, wherein the plurality of first hollow particles have a median diameter of 16 μm or more and 65 μm or less.

5. The light-emitting device according to any one of claims 1 to 4, wherein the plurality of first hollow particles are hollow silica or hollow glass.

6. On the first surface of the substrate, there is further a sealing member that covers the light-emitting element, The light-emitting device according to any one of claims 1 to 5, wherein the sealing member has a second resin and a plurality of second hollow particles contained in the second resin.

7. The light-emitting device according to claim 6, wherein the plurality of second hollow particles are unevenly distributed on the surface side of the sealing member.

8. The light-emitting device according to claim 6 or 7, wherein the plurality of second hollow particles have a median diameter of 16 μm or more and 65 μm or less.

9. The light-emitting device according to any one of claims 6 to 8, wherein the plurality of second hollow particles are hollow silica or hollow glass.

10. The light-emitting device according to any one of claims 1 to 9, wherein the reflectance of the first reflecting member is 60% or more.

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