Method for manufacturing a 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 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 that seals 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. Irregularities 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] A method for manufacturing a light-emitting device according to the embodiment of the present disclosure comprises the steps of: preparing an intermediate having 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 with 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 reflective member, wherein 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. [Effects of the Invention]

[0007] According to the embodiments of this disclosure, it is possible to realize a light-emitting device and a method for manufacturing the same in which the reflectivity of the reflective member surrounding the light-emitting element is high and the generation of stray light can be suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view showing the light-emitting device according to the embodiment. [Figure 2] This is a schematic plan view showing a light-emitting device according to an embodiment. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4] This is a cross-sectional view along line IV-IV in Figure 2. [Figure 5] Figure 2 is a cross-sectional view along the VV line. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 2. [Figure 7] This is a schematic plan view showing a first reflective member, a second reflective member, and a wire in a light-emitting device according to an embodiment. [Figure 8] This is a schematic enlarged cross-sectional view showing a part of the first reflective member of the light-emitting device according to the embodiment. [Figure 9]It is a graph showing the relationship between surface roughness Ra and dulling. [Figure 10] It is a schematic cross-sectional view for explaining a method of measuring an angle formed by a first surface of a substrate and a first reflecting member. [Figure 11] It is a flowchart for explaining a method of manufacturing a light-emitting device according to an embodiment. [Figure 12A] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12B] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12C] It is an enlarged plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12D] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12E] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12F] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12G] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 12H] It is a plan view schematically showing a method of manufacturing a light-emitting device according to an embodiment. [Figure 13A] In a first modification of the embodiment, it is an enlarged cross-sectional view schematically showing a part of the first reflecting member. [Figure 13B] In a second modification of the embodiment, it is an enlarged cross-sectional view schematically showing a part of the first reflecting member. [Figure 13C] In a third modification of the embodiment, it is an enlarged cross-sectional view schematically showing a part of the first reflecting member. [Figure 13D] In a fourth modification of the embodiment, it is an enlarged cross-sectional view schematically showing a part of the first reflecting member. [Figure 14] It is a cross-sectional view schematically showing a fifth modification of the embodiment. [Figure 15] It is a partial cross-sectional view in a fifth modification of the embodiment. [Figure 16]This is an enlarged cross-sectional view schematically showing a part of the sealing member in a fifth modified example of the embodiment. [Modes for carrying out the invention]

[0009] 《Embodiment》 The following description of the light-emitting device and its manufacturing method according to the embodiment will be explained with reference to the drawings. Note that the size and positional relationships of the components shown in each drawing may be exaggerated for clarity of explanation. Also, the dimensions and placement of each component may not strictly match between the plan view and the corresponding cross-sectional view. In order to avoid making the drawings excessively complex, some elements may be omitted from the illustration, 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. In principle, the same name and reference numerals indicate the same or similar components, and detailed explanations may be omitted as appropriate. Also, in the embodiments, "covering" or "covering" is not limited to direct contact, but also includes indirect covering, for example, through other components. In this specification, a plan view means observation from the light extraction surface side of the light-emitting device.

[0010] [Light-emitting device] Figure 1 is a schematic perspective view showing a light-emitting device according to an embodiment. Figure 2 is a schematic plan view showing a light-emitting device according to an embodiment. Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 2. Figure 5 is a cross-sectional view taken along line VV in Figure 2. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 2. Figure 7 is a schematic plan view showing the first reflective member, the second reflective member, and a wire in the light-emitting device according to an embodiment. Figure 8 is a schematic enlarged cross-sectional view showing a part of the first reflective member of the light-emitting device according to an embodiment. Note that Figure 8 schematically shows the part indicated by reference numeral A in Figure 5. Figure 9 is a graph showing the relationship between surface roughness Ra and matte finish. Figure 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 reflective member. Note that in the drawings, the first wire 31, second wire 32, third wire 33, etc., which are arranged inside the covering member 40, may not be visible, but for the sake of explanation, they are shown in a form in which the first wire 31, etc., are visible.

[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 reflective member 41 surrounding the light-emitting elements 1 and arranged on the first surface 10a of the substrate 10. The first reflective member 41 has a first resin 51 and a plurality of first hollow particles 52 contained in the first resin 51, and the surface of the first reflective member 41 is uneven due to the first hollow particles 52, the surface roughness Ra of the first reflective member 41 is 0.10 μm or more and 3.0 μm or less, and the reflectance of the first reflective member 41 is 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 wires 130, a first reflective member 41 disposed on the first substrate 10 and in contact with the covering member 40, a second reflective member 42 disposed on the second substrate and in contact with the covering member 40, a third reflective member 7 that covers the sides of the light-emitting elements 1 on the first substrate 10, and a light-transmitting member 5 that covers the upper surface of the light-emitting elements 1. The following describes each component.

[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 surface, the first surface 10a, on which a plurality of light-emitting elements 1 are mounted, and wiring is arranged in the element mounting region 13 so as to constitute a predetermined electrical circuit. The first substrate 10 has a plurality of 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 such as silicon, and the area on the upper surface where no wiring is arranged is covered with an insulating film. Wiring may also be arranged inside the support member or on the lower surface. For example, the first substrate 10 can be an integrated circuit (IC) substrate in which circuits for driving and controlling a plurality of light-emitting elements 1 are integrated. Multiple light-emitting elements 1 are arranged in a matrix within the element mounting area 13. However, the multiple light-emitting elements 1 are not limited to being arranged in a matrix of two rows and / or two or more columns; they may also be arranged in only one row or only one column. In plan view, the element mounting area 13 can be, for example, a rectangular area. In this case, the element mounting area 13 is rectangular, and the first terminals 110 are arranged in a row along the opposing long sides of the rectangle, flanking the element mounting area 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 first long side. The first external connection terminals 11 are terminals to which one end of the first wire 31 is connected. The second external connection terminals 12 are terminals 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 approximately rectangular in shape, and each is spaced apart from the others and arranged in a row along the long side of the element mounting area 13.

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

[0016] (Second board) The second substrate 20 includes a flat substrate and wiring arranged on at least the upper surface of the substrate. The second substrate 20 has a substrate mounting area 23 on its upper surface on which the first substrate 10 is placed, and further has a second terminal 120 on its upper surface outside the substrate mounting area 23. The substrate mounting area 23 is the area on which the first substrate 10 is mounted via a bonding member. This substrate mounting area 23 is set to have an area equivalent to the planar shape of the first substrate 10. If the first substrate 10 is rectangular in planar view, the substrate mounting 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 mounting area 23 in between.

[0017] The first wire connection terminals 21 are arranged in a row along one of the longer sides of the rectangular substrate mounting area 23, outside the substrate mounting area 23. The first wire connection terminals 21 are terminals to which the other end of the first wire 31, one end of which is connected to the first external connection terminal 11, is connected. The second wire connection 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 (that is, the side located on the opposite side of the substrate mounting area 23 from the aforementioned long side). The second wire connection terminals 22 are terminals to which the other end of the 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 connection terminals 21 and the second wire connection terminals 22 are each approximately rectangular in shape, spaced apart from each other, and arranged 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 materials and forming methods as those used for the wiring of the first substrate 10, as described earlier. The second substrate 20, as an example, is provided with a plurality of second drive terminals 16 on its upper surface for handling drive signals for turning the light-emitting element 1 on or off. The second drive terminals 16 are located, for example, on the upper surface inward from the first wire connection terminal 21 (i.e., on the substrate mounting area 23 side). The third wire 33, which will be described later, is connected to these 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 shielding properties and substrate strength. Specifically, 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 composite materials composed of resin and metal or ceramics. The substrate can be a flat plate, or a substrate with a cavity on its upper surface can be used. In this case, the second substrate 20 can have the bottom of the cavity used as a substrate mounting area, and the first substrate 10 can be placed inside 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 joined together 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. In particular, it is preferable to use gold, which has excellent thermal resistance. The diameter of the wire can 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, and a third wire 33 that handles the driving signal for turning the light-emitting element 1 on or off. The third wire 33 is connected to a first drive terminal 15 located on the first substrate 10 and a second drive terminal 16 located on the second substrate 20. The first wire 31, the second wire 32, and the third wire 33 can each be made of equivalent materials, differing only in length. The wire 130 can be positioned to straddle the longer side of the first substrate 10, which is roughly rectangular in plan view, for example, so as to be approximately perpendicular to the longer side.

[0021] (light-emitting element) The light-emitting element 1, for example, has a substantially rectangular shape in plan view and comprises a semiconductor laminate and positive and negative electrodes arranged 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 side with the electrodes facing downwards. In this case, the upper surface opposite to the side with the electrodes 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 on the first substrate 10 at predetermined intervals in the matrix direction. The size and number of light-emitting elements 1 used can be appropriately selected depending on the form of the light-emitting device to be obtained. In particular, it is preferable to mount more small light-emitting elements 1 at a higher density. This makes it possible to control the illumination range with a larger number of divisions and allows it to be used as a light source for a high-resolution illumination system. For example, 1,000 to 20,000 rectangular light-emitting elements 1 with sides of 40 to 100 μm in plan view are used and arranged in a matrix so that the whole thing forms a rectangle.

[0022] The light-emitting element 1 can be selected to have any wavelength. For example, blue or green light-emitting elements 1 can be made of ZnSe or nitride semiconductors (In X Al Y Ga 1-X-Y A semiconductor element using N (0 ≤ X, 0 ≤ Y, X + Y ≤ 1) or GaP can be selected. Furthermore, for the red light-emitting element 1, semiconductors represented by GaAlAs and AlInGaP can be suitably used. In addition, 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 can be appropriately selected according to the purpose.

[0023] (Jointing member) As shown in Figure 6, the light-emitting element 1 is bonded to the wiring arranged in the element mounting area 13 of the first substrate 10 by a conductive bonding member. When the light-emitting element 1 is flip-chip mounted on the first substrate 10, bumps made of metallic materials such as Au, Ag, Cu, and Al can be used as bonding members. Alternatively, solder such as an AuSn alloy or Sn-based lead-free solder may be used as bonding members. In this case, the light-emitting element 1 can be bonded to the first substrate 10 by reflow soldering. Alternatively, a conductive adhesive containing conductive particles in resin can be used as a bonding member. The bond between the light-emitting element 1 and the first substrate 10 may also be formed by plating. Copper is an example of such material. Furthermore, the bonding between the light-emitting element 1 and the first substrate 10 may be achieved by direct bonding between the electrodes of the light-emitting element 1 and the wiring of the first substrate 10, without the use of a bonding member.

[0024] (Third reflective member) As shown in Figure 6, the third reflective 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 reflective member 7. The third reflective member 7 may also cover the space between the lower surface of the light-emitting element 1 and the first substrate 10. The third reflective member 7 reflects the light emitted from the side surface of the light-emitting element 1 and causes 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. This improves the light extraction efficiency of the light-emitting device 100. In addition, 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. Furthermore, the third reflective member 7 may be positioned at a distance from the first reflective member 41, or it may be positioned in contact with the first reflective member 41.

[0025] Furthermore, it is preferable to use a soft resin with relatively low elasticity and excellent shape conformability for the third reflective member 7. Suitable materials for the third reflective member 7 include resin materials with good insulating properties, such as thermosetting resins like epoxy resin and silicone resin. It is also preferable to use a white resin in which particles of a light-reflective substance are contained in the base resin of the third reflective member 7. Suitable light-reflective substances include, for example, titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass fillers. The third reflective member 7 may also contain light-absorbing substances such as carbon black and graphite.

[0026] (Translucent member) The light-transmitting member 5 is light-transmitting and covers the upper surfaces of the multiple light-emitting elements 1. The light-transmitting member 5 covers the upper surfaces of the multiple light-emitting elements 1 and the upper surface of the third reflective member 7 together. The upper surface of the light-transmitting member 5 constitutes 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 elements 1 before emitting it to the outside. Examples of wavelength conversion members include phosphors. The light-transmitting member 5 is approximately rectangular in plan view and is arranged to cover the upper surfaces of the multiple 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 it may be applied in layers on the light-emitting element 1 by spraying or the like. Alternatively, it may be formed by injection molding using a mold, transfer molding, compression molding, or the like. Examples of translucent members containing wavelength conversion members include sintered phosphors and those containing phosphor powder in a base material such as resin, glass, or other inorganic material. Translucent materials such as epoxy resin, silicone resin, a mixture thereof, or glass can be used as the base material. The thickness of the translucent member 5 can be, for example, about 20 μm to 100 μm. The translucent member 5 is formed to cover the entire upper surface of the multiple light-emitting elements 1. In this case, the translucent member 5 extends to a position where it contacts the first reflective member 41, which will be described later.

[0028] Examples of phosphors include yttrium aluminum garnet phosphors (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 Nitride-based phosphors such as (Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), fluoride-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), perovskite-structured phosphors (e.g., CsPb(F,Cl,Br,I)3), or quantum dot phosphors (e.g., CdSe, InP, AgInS2, or AgInSe2) can be used.

[0029] (Covering material) The covering member 40 is a light-shielding resin that covers the wires 130 (specifically the first wire 31 and the second wire 32) outside the element mounting area 13. For example, the covering member 40 is arranged in a frame shape in plan view, covering the first wire 31 and the second wire 32 and surrounding the element mounting area 13. The covering member 40 is positioned in contact with the first reflective member 41, which will be described later. The covering member 40 also covers the third wire 33. The covering member 40 is positioned away from the light-transmitting member 5.

[0030] Furthermore, the frame-shaped covering member 40 has a wider width on the longer side of the rectangle of the roughly rectangular first substrate 10 than on the shorter side. In addition, the covering member 40 is positioned such that its height (i.e., the distance from the top surface of the second substrate 20 to the top surface of the covering member 40) is 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 positioned so that its top 40a overlaps with the top 130a of the wire 130. Note that the position of the top 40a of the covering member 40 is positioned above the top 41a of the first reflective member 41, which will be described later.

[0031] Examples of light-shielding coating members 40 include resins containing light-shielding fillers. Examples of base resins include silicone resins, modified silicone resins, epoxy resins, modified epoxy resins, acrylic resins, etc. Examples of light-shielding fillers include light-absorbing substances such as pigments, carbon black, and graphite, and light-reflective substances similar to those contained in the third reflective member described above. Specifically, examples include white resins with excellent light reflectivity, black resins with excellent light absorption, and gray resins with both light reflectivity and light absorption. The coating member 40 may also consist of multiple laminated layers of these resins. In particular, considering the degradation of the resin due to light absorption, it is preferable that the covering member 40 be made of a white resin that has light reflectivity at least on its outermost surface.

[0032] (First reflective member, second reflective member) The light-emitting device 100 has a first reflective member 41 positioned along the element mounting area 13 on the first substrate 10 between the element mounting area 13 and the first terminal 110, and in contact with the covering member 40. Furthermore, the light-emitting device 100 has a second reflective member 42 positioned outside the second terminal 120 on the upper surface of the second substrate 20, and in contact with the covering member 40. In other words, the covering member 40 is positioned between the first reflective member 41 and the second reflective member 42, extending from the upper surface of the first substrate 10 to the upper surface of the second substrate 20. The covering member 40 is positioned between a first reflective member 41, which is arranged on the first substrate 10 to surround the element mounting area 13, and a second reflective member 42, which is arranged on the second substrate 20 to surround the substrate mounting area 23. This arrangement of the covering member 40 can be formed by supplying the uncured resin constituting the covering member 40 into a frame enclosed 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 to block 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 made to a predetermined height by arranging multiple layers of uncured resin in the height direction. For example, the first reflective member 41 and the second reflective member 42 are made to a predetermined height by placing a layer of resin adjusted to a predetermined viscosity from a nozzle onto a substrate and repeating this process.

[0034] The height of the first reflective member 41 from the top surface of the first substrate 10 may be the same as or different from the height of the second reflective member 42 from the top surface of the second substrate 20. If they are different, it is preferable to make the second reflective member 42 taller than the first reflective member 41. In this case, the difference between the height from the top surface of the second substrate 20 to the top of the first reflective member 41 and the height from the top 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 (i.e., the distance from the top surface to the bottom surface of the first substrate 10). This makes it possible to suppress the uncured coating member 40 from overflowing to the outside of the second reflective member 42 when the coating member 40 is placed between the first reflective member 41 and the second reflective member 42.

[0035] The first reflective member 41 is arranged in a rectangular frame shape in plan view that surrounds the element mounting area 13. The covering member 40 is, for example, arranged to be in contact with the top of the first reflective member 41. The first reflective member 41 is arranged on the first substrate 10 in a rectangular frame shape in plan view, along the outer circumference of the element mounting area 13. When the first reflective member 41 is positioned along the longitudinal direction of the element mounting area 13, it is positioned between the longitudinal side of the element mounting area 13 and the plurality of first terminals 110, and when the first reflective member 41 is positioned along the short direction of the element mounting area 13, it is positioned on the first substrate 10 between the element mounting area 13 and the outer edge of the first substrate 10.

[0036] Furthermore, it is preferable that the first reflective member 41 has an inclined surface that slopes from the first substrate 10 side toward the top of the first reflective member 41. The inclined surface is preferably a curved surface that is convex outward. Specifically, it is preferable that the first reflective member 41 is substantially semicircular or substantially semielliptical in a cross-sectional view perpendicular to the first surface 10a of the first substrate 10. This allows the surface of the covering member 40 that contacts the first reflective member 41 to be a curved surface that is convex toward the covering member 40 side. Because the covering member 40 has such a shape, light emitted from the light-transmitting member 5, transmitted through the first reflective member 41 and toward the covering member 40 can be reflected toward the first substrate 10 side. This suppresses unintended leakage light and stray light from going upward (towards the light extraction side), and thus a light-emitting device with suppressed light scattering can be obtained.

[0037] In this embodiment, a semicircle is not limited to a semicircle in the strict sense, such as a perfect circle divided in two, but includes shapes that are visually close to a semicircle. For example, a circle that is distorted or deformed within the tolerance or error range may be considered a semicircle. Specifically, it includes a circle with a tolerance or error value of 5% or less relative to its diameter that has been considered a semicircle. If the value exceeds 5% relative to the diameter, it will be considered an ellipse. Note that a semicircle does not have to be a perfect division in two. Furthermore, the term "approximately semi-ellipse" in this embodiment is not limited to a strictly defined ellipse, which is the locus of points whose sum of distances from two fixed points on a plane is constant, divided into two equal parts. It also includes shapes that are visually perceived as being close to a semi-ellipse. For example, it may be an oval shape, a small oval shape, or the shape of an athletics track, which are obtained by stretching a circle in one direction, and then dividing them into two equal parts. In other words, it may be an approximately ellipse divided into two equal parts. An approximately ellipse also includes a shape enclosed by a pair of straight lines or curves extending along the longitudinal or transverse direction, and a pair of curves connected to this pair of straight lines or curves and curving outward in a convex shape. For example, a shape can be obtained by connecting the same ends of two opposing parallel sides or two opposing curved sides with circular arcs of the same diameter (for example, semicircular arcs). Note that the semi-ellipse does not have to be a strictly defined bisection.

[0038] As shown in Figure 8, the first reflective member 41 has a first resin 51 and a plurality of first hollow particles 52 contained in the first resin 51. That is, the first reflective member 41 contains a plurality of first hollow particles 52. The first reflective member 41 has irregularities formed on its surface by the first hollow particles 52. Specifically, the surface roughness Ra of the first reflective member 41 is 0.10 μm or more and 3.0 μm or less. If the surface roughness Ra of the first reflective member 41 is 0.10 μm or more, the light from the light-emitting element 1 that hits the first reflective member 41, as well as reflected light from inside the device and external light, are diffusely reflected, and the generation of stray light is suppressed. This makes it possible to obtain a desired irradiation pattern. On the other hand, if the surface roughness Ra of the first reflective member 41 is 3.0 μm or less, it becomes easier to form irregularities on the surface of the first reflective member 41.

[0039] The surface roughness Ra of the first reflective member 41 is preferably 0.50 μm or more and 2.0 μm or less. If the surface roughness Ra of the first reflective 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 reflective member 41 is 2.0 μm or less, it becomes easier to form irregularities on the surface of the first reflective member 41. The range of surface roughness Ra was determined by referring to the graph in Figure 9, which shows the relationship between surface roughness Ra and matte finish.

[0040] The surface roughness Ra of the first reflective member 41 can be determined, for example, by measuring 2000 μm at a speed of 200 μm / s using a stylus-type step thickness gauge (Alpha-Step-IQ manufactured by KLA Tencor). In the light-emitting device 100, a portion of the first hollow particles 52 are 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. Also, although the first hollow particles 52 are shown adjacent to each other in Figure 8, the first resin 51 may be interposed between the first hollow particles 52. Furthermore, the first hollow particles 52 may be arranged in a mixture of adjacent and interposed states.

[0041] The reflectivity of the first reflective member 41 is 40% or higher. If the reflectivity of the first reflective member 41 is low, that is, if the transmittance of the first reflective member 41 is high, light transmitted through the first reflective member 41 may be reflected by the first substrate 10, etc., potentially generating stray light. In addition, the interior of the first reflective member 41 may become visible, resulting in a poor appearance. If the reflectivity of the first reflective member 41 is 40% or higher, the reflectivity of the first reflective member 41 is excellent, and the aforementioned problems can be suppressed. In this specification, the reflectivity is based on the emission peak wavelength of the light-emitting element, but it may also be based on light at 450 nm.

[0042] The reflectivity of the first reflective member 41 is preferably 60% or higher. If the reflectivity of the first reflective member 41 is 60% or higher, it can be made into a first reflective member 41 with superior reflectivity. There is no particular upper limit specified for the reflectivity of the first reflective member 41, but for example it may be 80% or less, or 90% or less. However, it is more preferable that the reflectivity of the first reflective member 41 is 95% or higher.

[0043] The first reflective member 41 contains a plurality of first hollow particles 52, and due to the effect of the refractive index difference between the outer shell of the first hollow particle 52 and the cavity inside the first hollow particle 52, it is possible to maintain a white appearance and also maintain a high level of reflectivity.

[0044] Examples of the first hollow particles 52 include hollow glass, hollow silica, porous silica, fly ash balloons, shirasu balloons, and hollow polymer particles. From the viewpoint of heat resistance, light resistance, etc., it is preferable that the multiple first hollow particles 52 are hollow silica or hollow glass.

[0045] The multiple 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 reflective member 41, making it easier to control the surface roughness Ra of the first reflective 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, making it easier to control the reflectance of the first reflective member 41. From the viewpoint of making it easier to control the surface roughness Ra of the first reflective 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 reflective 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 at which the volume accumulation frequency from the smaller diameter side reaches 50% in the volume-based particle size distribution measured by laser diffraction scattering particle size distribution analysis (volume median diameter). Laser diffraction scattering particle size distribution analysis can be performed using, for example, a laser diffraction particle size distribution analyzer (product name: MASTER SIZER3000, manufactured by MALVERN).

[0047] The content of the plurality of first hollow particles 52 contained in the first reflective member 41 is preferably 20 parts or more and 70 parts or less per 100 units of mass of the first resin 51. If the content of the plurality of first hollow particles 52 is 20 parts or more per 100 units of mass of the first resin 51, it becomes easier to form irregularities on the surface of the first reflective member 41, and it becomes easier to control the surface roughness Ra of the first reflective 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 reflective member 41. The content of the plurality of first hollow particles 52 is more preferably 20 parts or more and 50 parts or less per 100 units of 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. Furthermore, from the viewpoint of making it easier to control the surface roughness Ra of the first reflective member 41, it is more preferably 30 parts or more. Note that "parts" refers to the mass (g) of the additive relative to 100g of the resin base material. In other words, parts of the first hollow particles relative to 100g of the first resin is equivalent to parts by mass of the first hollow particles relative to 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 resins containing at least one of these resins.

[0049] It is preferable to use a first resin 51 with 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 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 the desired shape. On the other hand, if it is 1200 Pa·s or less, the resin can be discharged from the discharge device quickly, improving work efficiency. From the viewpoint of making it easier to form the first reflective 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] The first resin 51 may contain nanofillers such as Aerosil® to increase its viscosity and impart thixotropy. In this embodiment, the first resin 51 contains nanofillers 53. Examples of nanofillers 53 include nanosilica. If the viscosity becomes too high due to excessive filling with nanofillers 53, a solvent can be added to reduce the viscosity. The solvent that can be used is preferably one that is compatible with the base resin. For example, when using a silicone resin as the base material, aromatic hydrocarbons (xylene and toluene), petroleum hydrocarbons (benzine, petroleum ether, etc.), ethers (diethyl ether, THF, etc.) can be used.

[0051] The first reflective member 41 has multiple first hollow particles 52 dispersed in the first resin 51. The dispersion of multiple first hollow particles 52 in the first resin 51 improves the reflectivity of the first reflective member 41. In this embodiment, the dispersion of multiple first hollow particles 52 in the first resin 51 means that, when observing a predetermined location in the cross-section of the first reflective member 41, the difference in the proportion of first hollow particles 52 in any two locations of the same area is less than 1.5 times. Specifically, the calculation of the proportion (abundance) of first hollow particles 52 can be performed as follows. First, a cross-sectional image of the first reflective member 41 is taken, and the abundance of the first hollow particle 52 is calculated at any two locations. The two images are taken at the same magnification, and the abundance of the first hollow particle 52 is calculated as "area of ​​the first hollow particle 52 ÷ 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 (JEOL Ltd. JSM-IT200) using the measurement function of the electron microscope, or they may be calculated from the mass of a piece cut out of printed paper. The area of ​​the resin portion is the area excluding parts other than the resin portion, such as the substrate, shown in the photograph.

[0052] In the light-emitting device 100, it is preferable that the angle between the first surface 10a of the first substrate 10 and the first reflective member 41 is between 60 degrees and 135 degrees. If the angle is within this range, the first reflective member 41 is easier to form, and the function of the first reflective member 41 is further improved. The angle between the first surface 10a of the first substrate 10 and the first reflective member 41 can be calculated by taking a photograph of the cross-section of the first reflective 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 circumference of the first reflective member 41 using the measurement function, as shown in Figure 10.

[0053] The second reflective member 42 is located below the light-emitting element 1 and the light-transmitting member 5 in the light-emitting device 100. It is positioned on the side opposite to the light extraction side. For this reason, the second reflective member 42 may or may not be transparent to light emitted from the light-emitting element 1. In the manufacturing process, the second reflective member 42 can be used as a dam to block the uncured coating member 40, similar to the first reflective member 41. For this reason, it is preferable that it be positioned in the same process as the first reflective member 41 or in a continuous process, 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 reflective member 41.

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

[0055] The light-emitting device 100 having the above configuration can be used, for example, as a light source for the headlights of a vehicle. In this case, for example, the light source is configured to emit light to the outside through a lens. The light-emitting device 100 lights up the light-emitting element 1 using an external power switch. The light-emitting device 100 is configured to allow some or all of the pre-set light-emitting elements 1 to be driven individually.

[0056] As for light-emitting devices, for example, those that can change the light distribution of vehicle headlights have been developed. Specifically, these include devices that use multiple LEDs arranged in a row, or LEDs (multi-chip type) that have multiple light-emitting elements and can be individually lit. The light emitted from these LEDs is projected forward through the lens of the lamp, but for fine control of the light distribution, the directionality of the light is becoming even more important. A known method for manufacturing light-emitting devices involves forming a frame around a light-emitting element with a light-reflective resin and filling the inside with a low-viscosity light-reflective resin. However, with this method, stray light can occur when light diffusely reflected within the headlight or lighting fixture is reflected by the light-reflective resin portion. This stray light then passes through the lens, resulting in an unintended illumination pattern. One possible solution to stray light is to blacken the resin part to absorb excess light, but this would reduce the LED output. Furthermore, if sunlight enters the light fixture, the black resin part may absorb the light and burn out. Similar concerns exist if fillers that absorb short-wave light, such as titanium dioxide, are added. While external light reflection on the light-emitting and sealing surfaces can be addressed by creating irregularities on the outermost surface, there was no way to address the resin frame portion.

[0057] In contrast, in the light-emitting device 100 of this 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 between 0.10 μm and 3.0 μm, the light hitting the first reflecting member 41 is diffusely reflected, suppressing the generation of stray light. This makes it possible to obtain a desired irradiation pattern and facilitates the optical design of the lens when used in combination with a lens. Furthermore, by containing multiple first hollow particles 52 in the first reflecting member 41, 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] [Manufacturing method for light-emitting devices] Next, an example of a method for manufacturing a light-emitting device according to the embodiment will be described. Figure 11 is a flowchart illustrating the manufacturing method of the light-emitting device according to the embodiment. Figures 12A to 12H are schematic plan views showing the manufacturing method of the light-emitting device according to the embodiment. Figure 12C is a schematic enlarged plan view showing the manufacturing method of the light-emitting device according to the embodiment. The light-emitting elements 1 are placed at predetermined intervals, but the intervals are omitted in all figures except the enlarged plan view of Figure 12C.

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

[0060] Furthermore, in the preparation step, a solvent may be added to the mixture, and in the step of forming the first reflective member 41, the solvent in the mixture may be evaporated to cure the mixture. In this embodiment, the case in which a solvent is added to 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 reflective member placement step S102, a second reflective member placement step S103, and a coating member placement step S104. The intermediate and mixture preparation step S101 includes the element placement step S11, the third reflective member placement step S12, the substrate placement step S13, the wire connection step S14, the light-transmitting member placement step S15, and the mixture preparation step S16. The first reflective member placement step S102 includes the mixture coating step S17 and the first reflective member formation step S18. The following describes each step. Note that the materials and arrangement of each component are as described in the above-mentioned description of the light-emitting device 100, so further explanation will be omitted 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 area 13 of the first substrate 10 (see Figures 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 after attaching the plurality of light-emitting elements 1 to the element mounting area 13 of the first substrate 10, the support substrate is peeled off. It is preferable to prepare the first substrate 10 with wiring such as the first terminal 110 already arranged before performing the element mounting step S11. The first terminal 110 can be formed by attaching metal foil such as Cu or Al, applying a paste of metal powder such as Cu or Ag, or plating with Cu or the like. In addition, the wiring that is electrically connected to the light-emitting elements 1 in the element mounting area 13 can be patterned by etching or printing. The first substrate 10 may be prepared by purchase or other means. The light-emitting element 1 can be electrically connected to the element mounting region 13 on the first substrate 10, for example, by a plating method.

[0063] The third reflective member placement step S12 is a step in which the side surface of the light-emitting element 1 is covered with the third reflective member 7 after the light-emitting element 1 has been placed on the element mounting area 13 of the first substrate 10 (see Figures 12B and 12C). Here, after the light-emitting element 1 is placed on the first substrate 10, the third reflective member 7, for example, a white resin, is placed between the light-emitting elements 1. In the third reflective member placement step S12, the top surface of the light-emitting element 1 is covered with a mask before placing the third reflective member 7, and the mask is removed after placing the third reflective member 7, thereby exposing the top surface of the light-emitting element 1 from the third reflective member 7.

[0064] The substrate mounting step S13 is the step of mounting the first substrate 10 onto the substrate mounting area 23 of the second substrate 20 (see Figures 12D and 12E). Here, the first substrate 10 on which the light-emitting element 1 is mounted is placed on the substrate mounting area 23 of the second substrate 20 and bonded to it via a bonding material such as sintered metal, sintered Ag, or sintered Cu. It is preferable to prepare the second substrate 20 with wiring such as the second terminal 120 already arranged on it before performing the substrate mounting step S13.

[0065] The wire connection process S14 is a process 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 Figure 12F). Specifically, multiple first external connection terminals 11 of the first substrate 10 and multiple first wire connection terminals 21 of the second substrate 20 are connected with multiple first wires 31, and multiple second external connection terminals 12 of the first substrate 10 and multiple second wire connection terminals 22 of the second substrate 20 are connected with multiple second wires 32. The wire connection process S14 also includes a process of connecting the first drive terminal 15 of the first substrate 10 and the second drive terminal 16 of the second substrate 20 with a third wire 33.

[0066] The translucent member placement step S15 is a step of placing translucent members 5 that cover a plurality of light-emitting elements 1 (see Figure 12G). The translucent members 5 are prepared in advance as sheets of a predetermined size and placed on the light-emitting elements 1. The translucent members 5 may be fixed on the light-emitting elements 1 via a translucent bonding member such as resin, or they may be fixed without a bonding member by utilizing the tackiness of the translucent members 5.

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

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

[0069] The first reflective member placement step S102 is a step of placing the first reflective member 41 on the upper surface of the first substrate 10 between the element mounting area 13 and the first terminal 110, so as to be aligned with the element mounting area 13 (see Figure 12H). The first reflective member placement step S102 includes a mixture coating step S17 and a first reflective member formation step S18.

[0070] The mixture coating step S17 is a step of coating the mixture onto the first surface 10a of the first substrate 10 so as to surround the light-emitting element 1. In the mixture coating step S17, the mixture for forming the first reflective member 41 is coated by supplying the uncured mixture for forming the first reflective member 41 from the nozzle of the dispenser and moving the nozzle along the element mounting area 13. When coating the mixture, in order to disperse the first hollow particles 52 in the first resin 51, it is preferable to stir the mixture by hand, then stir it at, for example, 1000 rpm or more for 1 minute or more, and then start coating within 30 minutes.

[0071] The first reflective member forming step S18 is a step in which the mixture is cured to form the first reflective member 41. The curing of the mixture is carried out, for example, at a temperature of 140°C to 160°C for 2 hours to 6 hours. In the first reflective member forming step S18, the amount of the mixture decreases as the solvent evaporates during curing, and the first hollow particles 52 are arranged on the surface of the first reflective member 41, forming irregularities on the surface of the first reflective member 41.

[0072] After the process of forming the first reflective member 41, irregularities are formed on the surface of the first reflective member 41 by the first hollow particles 52, and the surface roughness Ra of the first reflective member 41 is 0.10 μm or more and 3.0 μm or less. Preferably, after the process of forming the first reflective member 41, the surface roughness Ra of the first reflective member 41 is 0.50 μm or more and 2.0 μm or less. Also, after the process of forming the first reflective member 41, the reflectance of the first reflective member 41 is 40% or more. Preferably, after the process of forming the first reflective member 41, the reflectance of the first reflective member 41 is 60% or more. Also, after the process of forming the first reflective member 41, it is preferable that the angle between the first surface 10a of the substrate 10 and the first reflective member 41 is 60 degrees or more and 135 degrees or less. These matters are as described in the above description of the light-emitting device 100.

[0073] The second reflective member placement step S103 is the step of placing the second reflective member 42 on the upper surface of the second substrate 20, outside the second terminal 120 (see Figure 12H). It is preferable that the first reflective member 41 and the second reflective member 42 are made of the same material, which allows the first reflective member placement step S102 and the second reflective member placement step S103 to be performed as the same step. Furthermore, in the first reflective member placement step S102 and the second reflective member placement step S103, the second reflective member 42 may be placed first in the second reflective member placement step S103, and then the first reflective member 41 may be placed in the first reflective member placement step S102. In addition, the first reflective member placement step S102 may be performed simultaneously with the second reflective member placement step S103, so that the first reflective member 41 and the second reflective member 42 are placed substantially simultaneously.

[0074] The covering member placement step S104 is a step of placing a light-shielding covering member 40 that is outside the first reflective member 41, in contact with the first reflective member 41, and covering the wire 130. Specifically, it is a step of placing a light-shielding covering member 40, which has a resin base material with lower viscosity than the first reflective member 41 and the second reflective member 42, between the first reflective member 41 and the second reflective member 42. The covering member 40 is placed 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] Although the invention has been specifically described above in terms of embodiments for carrying it out, the spirit of the present invention is not limited to these descriptions and should be interpreted broadly based on the claims. Furthermore, various modifications and alterations based on these descriptions are also included in the spirit of the present invention. The following describes modified examples. Note that the materials and arrangement of each component are as described in the description of the embodiment, so their explanation will be omitted here as appropriate.

[0076] Variant form Figures 13A to 13D are schematic enlarged cross-sectional views showing a portion of the first reflective member in the first to fourth modified examples of the embodiment, respectively. Figure 14 is a schematic cross-sectional view showing the fifth modified example of the embodiment. Figure 15 is a partial cross-sectional view in the fifth modified example of the embodiment. Figure 16 is an enlarged cross-sectional view showing a portion of the sealing member in the fifth modified example of the embodiment. Note that Figure 16 schematically shows the part indicated by reference numeral B in Figure 15. Furthermore, components that have already been described are either denoted by the same reference numerals and their description is omitted, or they are omitted to avoid repetition of the same description.

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

[0078] [First variation] As shown in Figure 13A, the first reflective member 41A contains a first hollow particle 52a with a large median diameter and a first hollow particle 52b with a small median diameter. Even with this configuration, the reflectivity of the first reflective member 41A can be increased while suppressing the generation of stray light.

[0079] [Second variation, third variation] As shown in Figure 13B, the first reflective member 41B contains oxide particles 54. As shown in Figure 13C, the first reflective member 41C contains non-hollow spherical particles 55. Examples of spherical particles 55 include silica and glass. Since the oxide particles 54 and spherical particles 55 have a smaller median diameter than the first hollow particles 52, they fit into the gaps of the first hollow particles 52. With this configuration, the reflectivity can be improved. In addition, a portion of the oxide particles 54 and spherical particles 55 are exposed from the first resin 51. However, the oxide particles 54 and spherical particles 55 may not be exposed from the first resin 51, and the surfaces of the oxide particles 54 and spherical particles 55 may be covered with the first resin 51.

[0080] [Fourth variation] As shown in Figure 13D, in the first reflective 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. With this configuration, for example, when manufacturing a light-emitting device, even if the first hollow particles 52 are not exposed from the first resin 51 due to the amount of solvent mixed into the mixture or the amount of solvent to be evaporated, the reflectivity of the first reflective member 41D can be increased and the generation of stray light can be suppressed.

[0081] [Fifth variation] 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 located on the surface of a semiconductor laminate that are electrically connected to the first substrate 10 via element wires 34. The light-emitting device 100A also has a sealing member 60 on the first surface 10a of the substrate 10 that covers the light-emitting element 1A. The sealing member 60 has a second resin 61 and a plurality of second hollow particles 62 contained in the second resin 61. In a plan view, the sealing member 60 covers the light-emitting element 1A and the element wires 34. The sealing member 60 can protect the light-emitting element 1A and the like from external forces, dust, moisture, etc.

[0082] The sealing member 60 contains a plurality of second hollow particles 62 in the second resin 61. Preferably, the second hollow particles 62 are unevenly distributed on the surface side of the sealing member 60. The uneven distribution of the second hollow particles 62 on the surface side of the sealing member 60 allows for the formation of irregularities on the surface of the sealing member 60. This suppresses glossiness of the sealing member 60 caused by external light. Preferably, the surface roughness Ra of the sealing member 60 is 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, glossiness of 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 are said to be unevenly distributed on the surface side of the sealing member 60 if, when observing a predetermined location in the cross-section of the sealing member 60 in a direction perpendicular to the first surface 10a of the first substrate 10, the proportion of second hollow particles 62 present on the surface side and the proportion of second hollow particles 62 present on the bottom side differ by 1.5 times or more. Specifically, the proportion (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 of the second hollow particle 62 is calculated from the image of the surface side including the surface and the image of the bottom side including the bottom surface. The image of the surface side and the image of the bottom side are taken at the same magnification, and the abundance of the second hollow particle 62 is calculated as "area of ​​the second hollow particle 62 ÷ area of ​​the resin part" in the cross-sectional image. The respective areas may be calculated from the cross-sectional image taken with an electron microscope (JEOL Ltd. JSM-IT200) using the measurement function of the electron microscope, or they may be calculated from the mass of a piece cut out of printed paper. The area of ​​the resin part is the part excluding the parts other than the resin part, such as the substrate, that are shown in the photograph.

[0084] In the light-emitting device 100A, a portion of the second hollow particles 62 are exposed from the second resin 61. However, the second hollow particles 62 may not be exposed from the second resin 61, and their surfaces may be covered with the second resin 61. Also, although Figure 16 shows the second hollow particles 62 adjacent to each other, the second resin 61 may be interposed between the second hollow particles 62. Furthermore, the second hollow particles 62 may be arranged in a mixture of adjacent and interposed states. The second hollow particles 62 can be the same as those used for the first hollow particles 52. Preferably, the multiple second hollow particles 62 have a median diameter of 16 μm or more and 65 μm or less. More preferably, it is 20 μm or more, and even more preferably 30 μm or more. Furthermore, it is even more preferably 60 μm or less, and even more preferably 40 μm or less. Also, the multiple second hollow particles 62 are preferably hollow silica or hollow glass. The reasons for this are the same as those for the first hollow particles 52. The second resin 61 can be the same as that used for the first resin 51.

[0085] The sealing member 60 may contain nanofiller 53. Furthermore, multiple second hollow particles 62 can be used in combination, each having a different particle size. Also, similar to the first reflective member, one or more of the oxide particles 54, non-hollow spherical particles 55, and particles with a refractive index different from that of the base material second resin 61 can be used in combination with the second hollow particles 62. Additionally, the sealing member 60 may contain other particles as fillers, etc. Furthermore, the sealing member 60 may contain a wavelength conversion member. Examples of wavelength conversion members include phosphors. Examples of phosphors include those exemplified in the light-transmitting member 5 of the light-emitting device 100.

[0086] The manufacturing method for the light-emitting device 100A involves placing a light-emitting element 1A on the first surface 10a of the first substrate 10, connecting element wires 34 to form a first reflective member 41, and then placing a sealing member 60 within the frame of the first reflective member 41. In the step of placing the sealing member 60, for example, a second resin 61 mixed with second hollow particles 62 is placed within the frame by potting or spraying. Then, for example, the second resin 61 is cured at a temperature of 120°C to 200°C 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] Furthermore, although the light-emitting device is described as having multiple light-emitting elements, it may also be a light-emitting device with only one light-emitting element. Additionally, it may be a light-emitting device without a second reflective member and a covering member. The method for manufacturing the light-emitting device may include other steps between or before / after each of the aforementioned steps, as long as they do not adversely affect the aforementioned steps. For example, it may include a foreign matter removal step to remove foreign matter that has been mixed in during the manufacturing process. Furthermore, the order of each step may be adjusted to the extent possible. Also, the solvent may not be mixed in the mixture preparation step. [Examples]

[0088] The following describes some examples. Nos. A1 to A9 are examples that satisfy the configuration of the embodiment, while Nos. B1 to B3 are comparative examples that do not satisfy the configuration of the embodiment.

[0089] [No.A1] (Resin compounding) 10g of base resin OE-6351 (dimethyl silicone manufactured by DuPont-Toray Specialty Materials Co., Ltd.) was placed in a dedicated stirring container (High Resist Container BHR-150 manufactured by Kinki Container 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 thoroughly mixed by hand with a spatula. The mixture was then uniformly stirred at 1200 ppm / 3 minutes using a stirrer (Awatori Rentaro ARV-310LED manufactured by Thinky Co., Ltd.).

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

[0091] (Measurement of transmittance and reflectance of cured material) A frame made by layering two 0.18 μm fluororesin tapes was attached to a glass slide. Stirred resin was poured into the inside of the frame and the thickness was adjusted to the brim using a squeegee. The resin was then cured at 150°C for 4 hours. The transmittance of the cured sample was measured by setting a spectrophotometer (Hitachi High-Tech Science Co., Ltd. U-3900) so that light entered from the resin surface, and the transmission spectrum was measured. The value at 470 nm of the obtained transmission spectrum was taken as the transmittance. The reflectance was measured by setting a spectrophotometer (Murakami Color Research Institute Co., Ltd. CMS-35SP) so that light struck the resin surface, and the reflection spectrum was measured under conditions including specular reflection. The value at 470 nm of the obtained reflection spectrum was taken as the reflectance.

[0092] (Measurement of surface roughness Ra of the cured material) The stirred resin was placed in a syringe fitted with a needle with an inner diameter of 0.66 mm, and dispensed in a linear fashion onto an alumina ceramic substrate using a dispenser (ML-5000XII, manufactured by Musashi Engineering Co., Ltd.). The resin was cured at 150°C for 4 hours. The cured material was measured using a stylus-type step thickness gauge (Alpha-Step-IQ, manufactured by KLA Tencor) at a speed of 200 μm / s over a distance of 2000 μm. The surface roughness Ra was defined as the value obtained at this measurement.

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

[0094] [No.A2] To 10 g of base resin OE-6351, 10 parts of nanosilica (RX200) and 50 parts of hollow glass (glass bubbles iM16K) with a median diameter of 20 μm were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0095] [No.A3] To 10 g of base resin OE-6351, 10 parts of nanosilica (RX200), 50 parts of hollow glass (glass bubbles S38) with a median diameter of 40 μm, and 5 parts of toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0096] [No.A4] To 10 g of base resin OE-6351, 10 parts of nanosilica (RX200), 30 parts of hollow glass (glass bubbles K1) with a median diameter of 65 μm, and 30 parts of toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0097] [No.A5] To 10 g of base resin OE-6351, 10 parts nanosilica (RX200), 25 parts hollow glass with a median diameter of 16 μm (glass bubbles iM30K), 25 parts hollow glass with a median diameter of 40 μm (glass bubbles S38), and 3 parts toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0098] [No.A6] To 10g of base resin OE-6351, 10 parts nanosilica (RX200), 40 parts hollow glass (Glass Bubbles S38) with a median diameter of 40μm, 10 parts non-hollow spherical silica (AdmaFine SO-C2, manufactured by Admatex Co., Ltd.) with a median diameter of 0.5μm, and 5 parts toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0099] [No.A7] To 10 g of base resin OE-6351, 10 parts nanosilica (RX200), 40 parts hollow glass (Glass Bubbles S38) with a median diameter of 40 μm, 10 parts titanium dioxide (R-960, manufactured by Chemours Co., Ltd.) with a median diameter of 0.5 μm, and 5 parts toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

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

[0101] [No.A9] To 10 g of base resin OE-6351, 10 parts of nanosilica (RX200), 20 parts of hollow glass (glass bubbles K1) with a median diameter of 65 μm, and 5 parts of toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0102] [No.B1] To 10 g of base resin OE-6351, 10 parts nanosilica (RX200), 100 parts titanium dioxide (R-960, manufactured by Chemours Co., Ltd.) with a median diameter of 0.5 μm, and 10 parts toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0103] [No.B2] To 10g of base resin OE-6351, 10 parts of nanosilica (RX200), 400 parts of non-hollow spherical silica (Kicross FR-2400TS, manufactured by Ryusen Co., Ltd.) with a median diameter of 20μm, and 10 parts of toluene as a solvent were added and thoroughly mixed. The mixture was then coated onto a ceramic substrate and cured. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0104] [No.B3] To 10 g of base resin OE-6351, 10 parts of hollow glass (glass bubbles S38) with a median diameter of 40 μm were added and thoroughly mixed, then coated and cured on a ceramic substrate. The resin preparation, curing, measurement of resin viscosity, and measurement of cured product were performed using the same method as in No. A1.

[0105] These results are shown in Table 1. Note that in Table 1, values ​​where measurement was not possible are indicated with "-".

[0106] [Table 1]

[0107] As shown in Table 1, Nos. A1 to A9 satisfy the configuration of the embodiment, resulting in good reflectivity and surface roughness of the cured product. The detailed results are as follows. No. A1 had a solvent added, and compared to No. A2, which did not have a solvent added, it had a higher surface roughness Ra. No. A3 and No. A4 had a larger median diameter in the hollow glass compared to No. A1, and therefore had a higher surface roughness Ra. However, their reflectivity was slightly lower. No. A4 had a larger median diameter of hollow glass compared to No. A3, and therefore a higher surface roughness Ra compared to No. A3. However, its reflectivity was slightly lower. Also, No. A4 had a higher amount of hollow glass added compared to No. A9, resulting in a higher surface roughness Ra and higher reflectivity compared to No. A9.

[0108] No. A5 uses two types of hollow glass with different median diameters, resulting in a higher reflectivity compared to No. A4. However, the surface roughness Ra was slightly lower. No. A6 uses a combination of hollow glass and non-hollow spherical silica, resulting in a higher surface roughness (Ra) compared to No. A3. However, its reflectivity was slightly lower. No. A7 was created by replacing the spherical silica in No. A6 with titanium oxide of the same median diameter, resulting in higher reflectivity compared to No. A6. No. A7 offered the best balance between reflectivity and surface roughness (Ra). No. A8 uses two types of hollow glass with different median diameters in combination with solid alumina, and has a higher reflectivity compared to No. A5.

[0109] On the other hand, since Nos. B1 to B3 do not satisfy the configuration of the embodiment, the following results were obtained. Because No. B1 used titanium dioxide instead of hollow particles, it had high reflectivity but low surface roughness (Ra). Because No. B2 used spherical silica that was not hollow instead of hollow particles, it had a high surface roughness Ra but low reflectivity. In No. B3, the amount of hollow glass added was insufficient, resulting in low resin viscosity and the inability to form a cured product with the desired shape. Consequently, the angle between the cured resin and the substrate was also very small. [Industrial applicability]

[0110] The light-emitting device according to the embodiment of this disclosure can be used as a light source for various purposes, such as vehicle headlights or projectors. [Explanation of Symbols]

[0111] 1,1A Light-emitting element 5 Translucent material 7. Third reflective member 10. First circuit board (circuit board) 10a First surface of the 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 mounting area 130 wires 130a wire top 31. First wire 32. Second wire 33 Third wire 34-element wire 40 Covering member 40a Top of the covering member 41a Top of the first reflective member 41, 41A, 41B, 41C, 41D First reflective member 42 Second reflective member 51 First resin 52 1st hollow particle 52a First hollow particle with a large median diameter 52b First hollow particle with small median diameter 53 Nanofillers 54 Oxide particles 55 Spherical particles 60 Sealing member 61 Second resin 62 2nd hollow particle 100, 100A Light-emitting device

Claims

1. A step of preparing an intermediate having a substrate having a first surface and one or more light-emitting elements disposed on the first surface of the substrate, and 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 element, The process includes a step of curing the mixture to form a first reflective member, In the preparation step described above, the content of the plurality of first hollow particles is 20 parts or more and 50 parts or less per 100 mass of the first resin. After the process of forming the first reflective member, the first hollow particles have formed irregularities on the surface of the first reflective member. A method for manufacturing a light-emitting device, wherein 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.

2. In the preparation step described above, a solvent is further mixed into the mixture. A method for manufacturing a light-emitting device according to claim 1, wherein in the step of forming the first reflective member, the solvent in the mixture is volatilized and the mixture is cured.

3. The method for manufacturing a light-emitting device according to claim 2, wherein in the preparation step, the content of the solvent in the mixture is 1 part or more and 30 parts or less per 100 mass of the first resin.

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

5. A method for manufacturing a light-emitting device according to any one of claims 1 to 4, wherein, after the step of forming the first reflective member, the surface roughness Ra of the first reflective member is 0.50 μm or more and 2.0 μm or less.

6. A method for manufacturing a light-emitting device according to any one of claims 1 to 5, wherein, after the step of forming the first reflective member, the reflectance of the first reflective member is 60% or more.

7. A method for manufacturing a light-emitting device according to any one of claims 1 to 6, wherein, after the step of forming the first reflective member, the angle between the first surface of the substrate and the first reflective member is 60 degrees or more and 135 degrees or less.

8. A method for manufacturing a light-emitting device according to any one of claims 1 to 6, further comprising the step of arranging a sealing member having a second resin and a plurality of second hollow particles contained in the second resin within the frame of the first reflective member after the step of forming the first reflective member.

9. The method for manufacturing a light-emitting device according to claim 8, wherein, in the step of arranging the sealing member, the plurality of second hollow particles are unevenly distributed on the surface side of the sealing member.

10. The method for manufacturing a light-emitting device according to claim 8 or 9, wherein in the step of arranging the sealing member, the plurality of second hollow particles have a median diameter of 16 μm or more and 65 μm or less.

11. A method for manufacturing a light-emitting device according to any one of claims 8 to 10, wherein, after the step of arranging the sealing member, the surface roughness Ra of the sealing member is 0.10 μm or more and 3.0 μm or less.

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