Light Emitting Module

Abstract

To provide a light-emitting module that can improve brightness.SOLUTION: A light-emitting module includes a first wiring board, a plurality of light emitting elements arranged on the first wiring board, a first light-transmitting layer covering the plurality of light emitting elements, a spacer disposed on the first light-transmitting layer, and a second light-transmitting layer disposed on the spacer. An air layer is arranged between the first light-transmitting layer and the second light-transmitting layer. In plan view, the spacer does not overlap with at least one light emitting element of the plurality of light emitting elements.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The embodiment relates to a light emitting module. [Background technology]

[0002] In recent years, light-emitting modules equipped with multiple light-emitting elements have been used as light sources for in-vehicle devices and projectors. A known configuration of such a light-emitting module is one in which multiple light-emitting elements are arranged on a submount, and the submount is further mounted on a wiring board (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-212301 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of an embodiment of the present invention is to provide a light-emitting module capable of improving brightness. [Means for solving the problem]

[0005] A light-emitting module according to an embodiment of the present invention includes a first wiring substrate, a plurality of light-emitting elements arranged on the first wiring substrate, a first transparent layer covering the plurality of light-emitting elements, a spacer arranged on the first transparent layer, and a second transparent layer arranged on the spacer. An air layer is arranged between the first transparent layer and the second transparent layer. In a plan view, the spacer does not overlap at least one light-emitting element of the plurality of light-emitting elements. [Effects of the Invention]

[0006] According to the embodiment of the present invention, a light emitting module capable of improving brightness can be realized. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view schematically showing a light emitting module according to a first embodiment, as viewed obliquely from above. [Figure 2] FIG. 2 is a perspective view of the light emitting module according to the first embodiment, seen obliquely from above, schematically showing the module with part of its configuration omitted. [Figure 3] FIG. 3 is a perspective view schematically showing the light emitting module according to the first embodiment, as viewed obliquely from below. [Figure 4] FIG. 4 is an enlarged plan view schematically showing region IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV shown in FIG. [Figure 6] FIG. 6 is a top view schematically showing the light emitting module according to the first embodiment. [Figure 7] FIG. 7 is a bottom view schematically showing the second light-transmitting layer and the spacers in the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a second light-transmitting layer and a spacer in the first embodiment. [Figure 9A] FIG. 9A is a diagram schematically showing an example of a method for manufacturing the spacer and the second light-transmitting layer in the first embodiment. [Figure 9B] FIG. 9B is a diagram schematically showing an example of a method for manufacturing the spacer and the second light-transmitting layer in the first embodiment. [Figure 9C] FIG. 9C is a diagram schematically illustrating an example of a method for manufacturing the spacer and the second light-transmitting layer according to the first embodiment. [Figure 9D] FIG. 9D is a diagram schematically showing an example of a method for manufacturing the spacer and the second light-transmitting layer in the first embodiment. [Figure 9E] FIG. 9E is a diagram schematically showing an example of a method for manufacturing the spacer and the second light-transmitting layer in the first embodiment. [Figure 10] FIG. 10 is a diagram schematically showing another example of the method for manufacturing the spacer and the second light-transmitting layer in the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view schematically showing a light-emitting module according to the second embodiment. [Figure 12] FIG. 12 is a top view schematically showing the second light-transmitting layer in the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view schematically showing a light-emitting module according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that each drawing is a schematic diagram and is appropriately emphasized or simplified. For example, in some drawings, the light-emitting element is depicted larger than it actually is compared to the light-emitting module. Furthermore, the dimensional ratios of the components are not necessarily consistent between drawings. To avoid overly complicated drawings, some elements may be omitted, or end views showing only the cut surface may be used as cross-sectional views.

[0009] First Embodiment The light-emitting module 1 according to the first embodiment has a rectangular shape in a plan view, and includes a first wiring substrate 20, a plurality of light-emitting elements 30 arranged on the first wiring substrate 20, a first light-transmitting layer 50 covering the plurality of light-emitting elements 30, a spacer 80 arranged on the first light-transmitting layer 50, and a second light-transmitting layer 90 arranged on the spacer 80. An air layer 100 is arranged between the first light-transmitting layer 50 and the second light-transmitting layer 90. In a plan view, the spacer 80 does not overlap at least one light-emitting element 30 of the plurality of light-emitting elements 30.

[0010] FIG. 1 is a perspective view schematically showing a light-emitting module according to this embodiment, as viewed obliquely from above. FIG. 2 is a perspective view of the light emitting module according to this embodiment, seen from diagonally above, schematically showing the module with part of its configuration omitted. FIG. 3 is a perspective view schematically showing the light-emitting module according to this embodiment, as viewed obliquely from below. FIG. 4 is an enlarged plan view schematically showing region IV in FIG. FIG. 5 is a cross-sectional view taken along line VV shown in FIG. FIG. 6 is a top view schematically showing the light emitting module according to this embodiment. FIG. 7 is a bottom view schematically showing the second light-transmitting layer and the spacers in this embodiment. FIG. 8 is a cross-sectional view schematically showing the second light-transmitting layer and the spacer in this embodiment. 2 and 4, the second light-transmitting layer and the spacers are not shown.

[0011] For ease of explanation, this specification employs an XYZ Cartesian coordinate system. The direction from the first wiring substrate 20 toward the second light-transmitting layer 90 is referred to as the "Z direction." The longitudinal direction of the light-emitting module 1 is referred to as the "X direction," and the lateral direction is referred to as the "Y direction." The Z direction is also referred to as "up" and the direction opposite the Z direction is also referred to as "down," but these expressions are also for convenience and are unrelated to the direction of gravity. Furthermore, the expression "planar view" in this specification refers to a view from the Z direction.

[0012] 1 to 5, the light-emitting module 1 of this embodiment includes a first wiring substrate 20, a second wiring substrate 10, a plurality of light-emitting elements 30, a second resin 40, a first light-transmitting layer 50, a plurality of wires 60, a first resin 70, a spacer 80, and a second light-transmitting layer 90. For convenience of illustration, the entire second light-transmitting layer 90, the entire spacer 80, part of the first resin 70, and part of the first light-transmitting layer 50 are omitted in FIG. 2, and part of the wires 60 and part of the light-emitting elements 30 are visualized.

[0013] The first wiring board 20 is, for example, a silicon board with an integrated circuit built in, such as an application specific integrated circuit (ASIC) board. The lower surface of the first wiring board 20 is bonded to the upper surface of the second wiring board 10 (described later) via a bonding member 15. The bonding member 15 may be made of silver paste, sintered silver, solder, or the like. The bonding member 15 is, for example, a silver paste containing a silicone resin. The first wiring board 20 has a rectangular shape in a plan view, and the central portion of the upper surface 21 of the first wiring board 20 is an area where the light emitting element 30 is mounted. Upper surface pads connected to the light emitting element 30 are arranged in this area, and first terminals 22 electrically connected to the upper surface pads are arranged around the periphery of this area.

[0014] The second wiring board 10 is, for example, rectangular in plan view and includes a flat-plate-shaped base 11 and wiring arranged on at least the upper surface of the base 11. The second wiring board 10 may be flat, or may have a recess on its upper surface for accommodating the first wiring board 20. The material for the base 11 is preferably a material with high heat dissipation properties, and more preferably a material with high light-blocking properties and strength. Specifically, the material for the base 11 may be metal such as aluminum (Al) or copper (Cu); ceramics such as aluminum oxide, aluminum nitride, silicon nitride, or mullite; resins such as phenolic resin, epoxy resin, polyimide resin, BT resin (bismaleimide triazine resin), or polyphthalamide (PPA); or a composite material composed of a resin and a metal or ceramics. Examples of materials for the wiring include metals such as copper (Cu), silver (Ag), gold (Au), aluminum (Al), platinum (Pt), titanium (Ti), tungsten (W), palladium (Pd), iron (Fe), or nickel (Ni), or alloys thereof.

[0015] As an example, second wiring board 10 is a laminated board made of a metallic member such as aluminum (Al) or copper (Cu) that constitutes the wiring, and an insulating member such as epoxy resin that constitutes base 11. Wiring is arranged on the surface and inside second wiring board 10. Some of the wiring forms a plurality of second terminals 12 on upper surface 10a of second wiring board 10, and other parts of the wiring form a plurality of lower surface pads 13 on lower surface 10b of second wiring board 10.

[0016] Furthermore, on the upper surface 10a and the lower surface 10b of the second wiring board 10, a metallic member is exposed from the insulating member to form a heat dissipation section 14. In a plan view, the heat dissipation section 14 is disposed in the center of the second wiring board 10, and a plurality of second terminals 12 and a plurality of lower surface pads 13 are disposed on both sides of the heat dissipation section 14, sandwiching the heat dissipation section 14 therebetween. The first wiring board 20 is disposed on the heat dissipation section 14 on the upper surface 10a of the second wiring board 10. The second terminals 12 and the lower surface pads 13 are arranged, for example, along the long side of the second wiring board 10.

[0017] The wires 60 are members for electrically connecting the second wiring board 10 and the first wiring board 20. The wires 60 are connected to the second terminals 12 of the second wiring board 10 and the first terminals 22 of the first wiring board 20. An example of the material for the wires 60 is gold (Au). For example, the number of wires 60 is the same as the number of second terminals 12. The multiple wires 60 are arranged in a row along the outer edge of the first wiring board 20 and are connected to the second wiring board 10 across the outer edge of the first wiring board 20.

[0018] The plurality of light-emitting elements 30 are mounted at the center of the upper surface 21 of the first wiring substrate 20. The light-emitting elements 30 have a substantially rectangular shape in a plan view. The plurality of light-emitting elements 30 are arranged, for example, in a matrix. In one example, the light-emitting elements 30, each having a substantially square upper surface, are arranged in 64 rows and 256 columns, for a total of 16,384 light-emitting elements 30. In one example, the arrangement pitch of the light-emitting elements 30 (e.g., the distance between the centers of adjacent light-emitting elements 30 in the X direction and / or Y direction) is 45 μm to 55 μm, and the length of one side of each light-emitting element 30 is 40 μm to 50 μm. Therefore, the distance between adjacent light-emitting elements 30 is 5 μm to 15 μm. In one example, the thickness of the light-emitting elements 30 is 5 μm to 10 μm. The light-emitting elements 30 are connected to upper surface pads on the upper surface 21 of the first wiring substrate 20. The light-emitting elements 30 are, for example, light-emitting diodes (LEDs) that emit, for example, blue light.

[0019] It should be noted that an element that emits light of any wavelength can be selected as the light emitting element 30. For example, a light emitting element that emits blue or green light can be made of ZnSe, nitride semiconductor (In x Al y Ga 1-x-y N, 0≦x, 0≦y, x+y<1), or GaP can be selected. Furthermore, semiconductors represented by GaAlAs or AlInGaP can be suitably used as the light-emitting element 30 that emits red light. Furthermore, semiconductor light-emitting elements made of materials other than these can also be used. The composition and emitted color of the light-emitting element 30 can be selected appropriately depending on the purpose.

[0020] The second resin 40 has optical reflectivity. The second resin 40 is disposed between adjacent light-emitting elements 30. Furthermore, the second resin 40 may be disposed between the upper surface 21 of the first wiring substrate 20 and the lower surface of the light-emitting element 30. That is, the second resin 40 may expose the upper surface of the light-emitting element 30 and cover the side and lower surfaces of the light-emitting element 30. The second resin 40 may be disposed to cover the entire side surface of the light-emitting element 30, or may be disposed to expose an upper portion of the side surface that is continuous with the upper surface 21 of the light-emitting element 30. By covering the side surface of the light-emitting element 30 with the optically reflective second resin 40, more light emitted from the light-emitting element 30 can be extracted from the upper surface 21. The second resin 40 includes a base material made of a translucent resin and a light-reflective substance contained in the base material. Increasing the content of the light-reflective substance in the second resin 40 can improve the light extraction efficiency from the light-emitting element 30. The concentration of the light-reflecting substance in the second resin 40 is preferably 50% by mass or more and 70% by mass or less, for example, about 60% by mass, from the viewpoint of improving light extraction efficiency and resin fluidity.

[0021] Examples of the translucent resin constituting the base material of the second resin 40 include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, and acrylic resin, as well as hybrid resins containing at least one of these resins. Among these, silicone resin, which has excellent heat resistance and light resistance, is preferred, and dimethyl silicone resin is more preferred. Dimethyl silicone resin has excellent reliability, such as high temperature resistance, and is therefore suitable for use as a material for automotive applications. Examples of the light-reflecting material that can be used include titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass filler. For example, the base material is dimethyl silicone resin, and the light-reflecting material is titanium oxide. The external color of the second resin 40 is, for example, white.

[0022] The first light-transmitting layer 50 is translucent and covers the upper surfaces of the light-emitting elements 30 and the second resin 40. The first light-transmitting layer 50 is in contact with the upper surface of the light-emitting elements 30, the upper portions of the side surfaces of the light-emitting elements 30, and the upper surface of the second resin 40. The first light-transmitting layer 50 is in contact with the upper surface of the first wiring substrate 20 in an area where the light-emitting elements 30 and the second resin 40 are not provided. The first light-transmitting layer 50 includes a base material made of at least a light-transmitting resin, and the base material may contain a phosphor. In one example, the thickness of the first light-transmitting layer 50 covering the light-emitting elements 30 (i.e., the distance from the upper surface of the light-emitting elements 30 to the upper surface of the first light-transmitting layer 50) is 25 μm to 35 μm. The upper surface of the first light-transmitting layer 50 located directly above the plurality of light-emitting elements 30 constitutes the light-emitting surface 38 of the light-emitting module 1.

[0023] The base material of the first light-transmitting layer 50 may be the same as the base material of the second resin 40. The phosphor may be an yttrium-aluminum-garnet phosphor (e.g., (Y,Gd)3(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), CCA-based phosphors (e.g., Ca 10 (PO4)6C l2 :Eu), SAE-based phosphors (e.g., Sr4Al 14 O 25 :Eu), chlorosilicate phosphors (e.g., Ca8MgSiO 16 C l2 :Eu), silicate-based phosphors (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon-based phosphors (e.g., (Si,Al)3(O,N)4:Eu) or α-sialon-based phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 oxynitride phosphors such as (La,Y)3Si6N 11:Ce), BSESN-based phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA-based phosphors (e.g., SrLiAl3N4:Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), etc., nitride-based phosphors, KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1), or fluoride-based phosphors such as MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2), etc. can be used.

[0024] The first resin 70 protects the wire 60 that connects the second wiring substrate 10 and the first wiring substrate 20. In plan view, the shape of the first resin 70 is a rectangular frame shape along the outer edge of the first wiring substrate 20. The first resin 70 covers a part of the upper surface of the second wiring substrate 10 and a part of the upper surface of the first wiring substrate 20. The wire 60 is disposed inside the first resin 70. That is, the first resin 70 covers the second terminal 12 of the second wiring substrate 10, the wire 60, and the first terminal 22 of the first wiring substrate 20. In one example, the height from the upper surface of the first wiring substrate 20 to the top of the first resin 70 is 200 μm to 500 μm. Here, the top of the first resin 70 means the highest position of the first resin in the cross-section passing through the light-emitting surface 38.

[0025] The first resin 70 may be translucent or light-blocking. In particular, the first resin 70 preferably has light-blocking properties, and more preferably has light-reflecting properties. This prevents deterioration or burnout of the first resin 70 due to absorption of external light, even when sunlight and other external light are concentrated near the light-emitting module 1 via an optical system, resulting in a highly reliable light-emitting module 1. For example, the first resin 70 is preferably white or near-white, which is less likely to absorb external light. The first resin 70 preferably includes a base material made of at least a translucent resin, and the base material preferably contains a light-reflecting substance. The base material may be made of the same material as the base material of the second resin 40 described above. The light-reflecting substance may be made of the same material as the light-reflecting substance of the second resin 40 described above. The concentration of the light-reflecting substance in the first resin 70 is preferably 15% by mass or more and 30% by mass or less, for example, approximately 23% by mass, from the viewpoints of reducing light absorption and improving resin fluidity. In one example, the base material is dimethyl silicone resin and the light-reflecting material is aluminum oxide.

[0026] As described above, the first resin 70 preferably has light reflectivity to suppress external light absorption, but the surface preferably has reduced gloss. A glossy surface tends to reflect much of the light emitted from the light-emitting surface 38, which can easily cause stray light (i.e., unnecessary reflection or scattering of light in the optical system). To suppress the gloss of the surface of the first resin 70, for example, the first resin 70 preferably has fine irregularities on its surface. The fine irregularities refer to, for example, a surface roughness Ra of the first resin of 0.10 μm or more and 3.0 μm or less. Such a surface shape can be formed, for example, by hardening a light-reflecting substance contained in the base resin before it settles in the resin. Furthermore, the first resin 70 may contain hollow particles that float easily in the resin as a filler for adjusting the surface shape. Examples of hollow particles include hollow glass, hollow silica, porous silica, fly ash balloons, shirasu balloons, and hollow polymer particles. From the viewpoints of heat resistance, light resistance, and the like, the hollow particles are preferably hollow silica or hollow glass. The first resin may contain a light absorbing material as a filler for adjusting light reflectivity, such as a black pigment such as carbon black, or graphite.

[0027] The second resin 40, the first light-transmitting layer 50, and the first resin 70 may each contain colorants, light diffusing materials, fillers for adjusting viscosity, etc., as needed, and the external colors of each may be different.

[0028] 5, the first resin 70 includes an outer resin frame 71 and a protective resin 73. The outer resin frame 71 is disposed on the second wiring board 10. The protective resin 73 is disposed inside the outer resin frame 71 on the second wiring board 10 and the first wiring board 20. The wires 60 are disposed within the protective resin 73. In this way, the protective resin 73 protects the wires 60.

[0029] Of the upper surface of the first translucent layer 50, an area surrounded by the first resin 70 becomes the light-emitting surface 38 of the light-emitting module 1. In other words, the first resin 70 is arranged so as to surround the light-emitting surface 38. On the light-emitting surface 38, a plurality of light-emitting elements 30 and the second resin 40 are arranged below the first translucent layer 50. Light emitted from the light-emitting elements 30 is reflected by the second resin 40, enters the first translucent layer 50, and is emitted from the light-emitting surface 38.

[0030] As shown in FIGS. 5 to 8 , the spacer 80 is disposed on the first light-transmitting layer 50. The spacer 80 is a member for separating the second light-transmitting layer 90 (described later) from the first light-transmitting layer 50 when the second light-transmitting layer 90 is disposed on the first light-transmitting layer 50. The lower surface of the spacer 80 is in contact with the upper surface of the first light-transmitting layer 50. In plan view, the spacer 80 has a frame shape that surrounds the plurality of light-emitting elements 30. In plan view, the spacer 80 does not overlap with at least one of the plurality of light-emitting elements 30. In this embodiment, the spacer 80 is disposed so as not to overlap with any of the light-emitting elements 30. In other words, in plan view, the spacer 80 surrounds the light-emitting surface 38. The spacer 80 contains, for example, a resin, and is made of, for example, a silicone resin.

[0031] The second light-transmitting layer 90 is disposed on the spacer 80. The second light-transmitting layer 90 has, for example, a rectangular plate shape. An upper surface 91 and a lower surface 92 of the second light-transmitting layer 90 are parallel to each other. The second light-transmitting layer 90 is separated from the first light-transmitting layer 50 via the spacer 80. As a result, an air layer 100 is disposed between the first light-transmitting layer 50 and the second light-transmitting layer 90. In plan view, the air layer 100 is located inside the spacer 80. That is, the air layer 100 is surrounded by the first light-transmitting layer 50, the spacer 80, and the second light-transmitting layer 90. The air layer 100 may be sealed by the first light-transmitting layer 50, the spacer 80, and the second light-transmitting layer 90, or may be in communication with the outside of the light-emitting module 1. The air layer 100 can be in communication with the outside by providing a communication path such as a groove in the spacer 80 and / or the lower surface 92 of the second light-transmitting layer, for example.

[0032] The second light-transmitting layer 90 is translucent. The second light-transmitting layer 90 is disposed on the first light-transmitting layer 50 via a spacer 80. In other words, the second light-transmitting layer 90 is disposed on the first light-transmitting layer 50 via an air layer 100. Light emitted from the first light-transmitting layer 50 enters the second light-transmitting layer 90 via the air layer 100. For this reason, it is preferable to use a material with a refractive index higher than that of air for the second light-transmitting layer 90. This allows light emitted from the light-emitting module 1 to be focused toward the optical system. Examples of materials for the second light-transmitting layer 90 include glass and resin. In particular, it is preferable to use a glass plate for the second light-transmitting layer 90. Examples of glass include borosilicate glass and quartz glass. By providing the second light-transmitting layer 90, the light-emitting module 1 can prevent deterioration of the second light-transmitting layer 90 due to light, heat, and the like emitted from the light-emitting element 30. Furthermore, the light-emitting surface 38 can be protected from adhesion of dust and the like.

[0033] 5, in the Z direction, the upper end of the first resin 70 is at approximately the same position as the upper surface 91 of the second light-transmitting layer 90. As a result, the upper surfaces of the first resin 70 and the second light-transmitting layer 90 form a substantially continuous surface. In one example, the thickness of the second light-transmitting layer 90 is not less than 200 μm and not more than 1 mm, and the thickness of the spacer 80 is not less than 100 μm and not more than 200 μm.

[0034] As shown in FIG. 6 , in a plan view, the second light-transmitting layer 90 is disposed inside the frame-shaped first resin 70. Furthermore, in a plan view, the outer edge of the spacer 80 coincides with the outer edge of the second light-transmitting layer 90. As an example, the side surfaces of the spacer 80 and the second light-transmitting layer 90 form a continuous plane, which is parallel to the Z direction. The side surfaces of the spacer 80 and the second light-transmitting layer 90 contact the protective resin 73 of the first resin 70. The protective resin 73 is disposed between the outer resin frame 71, the spacer 80, and the second light-transmitting layer 90, and is held by the outer resin frame 71, the spacer 80, and the second light-transmitting layer 90. In other words, the side surfaces of the second light-transmitting layer 90 and the side surfaces of the spacer 80 can function as an inner frame corresponding to the outer resin frame 71 (i.e., a member that holds the protective resin 73).

[0035] In this embodiment, in a plan view, the region of the second light-transmitting layer 90 inside the spacer 80 overlaps with the air layer 100, the first light-transmitting layer 50, and the plurality of light-emitting elements 30. That is, the second light-transmitting layer 90 faces the light-emitting surface 38 via the air layer 100. Furthermore, in a plan view, the region of the second light-transmitting layer 90 overlapping with the spacer 80 overlaps with the first light-transmitting layer 50, but does not overlap with the air layer 100 or the light-emitting elements 30. The first light-transmitting layer 50 contacts the first wiring substrate 20 and the spacer 80 around the light-emitting surface 38. Note that in this embodiment, no light-emitting element 30 is disposed between the first wiring substrate 20 and the spacer 80, but electronic components such as light-emitting elements and light-receiving elements that do not constitute the light-emitting surface 38 may be disposed therebetween.

[0036] Next, an example of a method for manufacturing the spacer 80 and the second light-transmitting layer 90 in this embodiment will be described. 9A to 9E are diagrams schematically showing an example of a method for manufacturing the spacer 80 and the second light-transmitting layer 90 in this embodiment.

[0037] First, as shown in Fig. 9A, a disk-shaped glass substrate 90a is prepared. Then, while the glass substrate 90a is being rotated, a resist is ejected onto the glass substrate 90a as a liquid resin material from a nozzle 201. This causes the liquid resin material to spread over the upper surface of the glass substrate 90a. In this manner, a resin film 80a is formed on the glass substrate 90a.

[0038] Next, as shown in FIG. 9B, the resin film 80a is exposed to light through a lattice mask 202. 9C, the resin film 80a is developed, whereby the resin film 80a is selectively removed to form a lattice-shaped resin frame 80b. Next, as shown in FIG. 9D, the resin frame 80b and the glass substrate 90a are cut along the resin frame 80b.

[0039] 9E, the glass substrate 90a is singulated into rectangular plate-shaped second light-transmitting layers 90, and the resin frame 80b is singulated into frame-shaped spacers 80. In this manner, the spacers 80 and the second light-transmitting layers 90 are produced.

[0040] Next, another example of a method for manufacturing the spacer 80 and the second light-transmitting layer 90 in this embodiment will be described. FIG. 10 is a diagram schematically showing another example of a method for manufacturing the spacer 80 and the second light-transmitting layer 90 in this embodiment.

[0041] As shown in FIG. 10, a liquid resin material is discharged from the nozzle 203 while the nozzle 203 is moved relative to the glass substrate 90a, and the resin material is arranged in a lattice pattern on the glass substrate 90a. The resin material is then solidified. This forms a lattice-shaped resin frame 80b on the glass substrate 90a. The subsequent manufacturing method is the same as the manufacturing method described as an example. That is, as shown in FIGS. 9D and 9E, the resin frame 80b and the glass substrate 90a are separated into individual pieces.

[0042] A method for manufacturing the light emitting module 1 according to this embodiment will be described. As shown in FIGS. 1 to 6, a first wiring substrate 20 is prepared, on which a plurality of light-emitting elements 30 are mounted and a second resin 40 is disposed between the plurality of light-emitting elements 30. Next, first wiring board 20 is placed on second wiring board 10 with bonding member 15 interposed therebetween. Next, the second terminals 12 of the second wiring board 10 and the first terminals 22 of the first wiring board 20 are connected by wires 60. Next, the first light-transmitting layer 50 is formed so as to cover the plurality of light-emitting elements 30 and the second resin 40.

[0043] Next, a structure made of the spacers 80 and the second light-transmitting layer 90, for example, produced by the method described above, is placed on the first light-transmitting layer 50. At this time, it is preferable to place the structure so that the spacers 80 are in contact with the uncured first light-transmitting layer 50. This allows the spacers 80 to be bonded to the first wiring substrate 20 using the first light-transmitting layer 50 as an adhesive. Next, outer resin frame 71 is formed on second wiring board 10. Next, a liquid resin material is poured between the outer resin frame 71 and the structure and cured, thereby forming the protective resin 73. In this way, the light emitting module 1 is obtained.

[0044] Next, the operation of the light-emitting module 1 according to this embodiment will be described. When power is supplied to the light-emitting element 30 via the second wiring substrate 10, the wire 60, and the first wiring substrate 20, the light-emitting element 30 emits light. For example, blue light is emitted from the light-emitting element 30. If the first light-transmitting layer 50 contains a phosphor, the phosphor absorbs the blue light emitted from the light-emitting element 30, and yellow light, for example, is emitted. As a result, white light, for example, a mixture of blue light and yellow light, is emitted from the first light-transmitting layer 50 toward the air layer 100.

[0045] Light emitted from the first light-transmitting layer 50 enters the second light-transmitting layer 90 through the air layer 100. At this time, because the refractive index of the glass constituting the second light-transmitting layer 90 is higher than the refractive index of the air layer 100, the light that is obliquely incident on the lower surface 92 of the second light-transmitting layer 90 is refracted at the lower surface 92, and its traveling direction becomes nearly perpendicular to the lower surface 92. This light is emitted to the outside of the light-emitting module 1 from the upper surface 91 of the second light-transmitting layer 90. In this way, by disposing the air layer 100 between the first light-transmitting layer 50 and the second light-transmitting layer 90, the light emitted from the light-emitting module 1 is more likely to be concentrated in the front surface (Z direction) of the light-emitting module 1. As a result, the brightness of the light-emitting module 1 is improved.

[0046] Next, the effects of this embodiment will be described. As described above, the light-emitting module 1 of this embodiment includes the second translucent layer 90, and an air layer 100 is disposed between the first translucent layer 50 and the second translucent layer 90, thereby improving brightness.

[0047] Furthermore, in this embodiment, the second light-transmitting layer 90 is opposed to the first light-transmitting layer 50 via the spacer 80, so that the distance between the first light-transmitting layer 50 and the second light-transmitting layer 90 can be made uniform. This allows for stable improvement in brightness regardless of the light-emitting element 30 that emits light.

[0048] Furthermore, in this embodiment, the second light-transmitting layer 90 covers the first light-transmitting layer 50 and the plurality of light-emitting elements 30, and therefore the first light-transmitting layer 50 and the light-emitting elements 30 can be protected from dust, moisture, etc. Even if foreign matter such as dust adheres to the upper surface 91 of the second light-transmitting layer 90, the foreign matter can be moved away from the light-emitting surface 38, which is the focal position of the optical system, in the Z direction, thereby reducing the effect on the projected image that has passed through the optical system.

[0049] Furthermore, in this embodiment, by holding the side surfaces of the first resin 70 substantially vertically by the spacers 80 and the second light-transmitting layer 90, light that is emitted from the first light-transmitting layer 50 and reflected on the side surfaces of the first resin 70 is less likely to be reflected upward. This makes it less likely that light reflected on the side surfaces of the first resin 70 will enter an external optical system, thereby suppressing stray light.

[0050] <Second embodiment> FIG. 11 is a cross-sectional view schematically showing the light-emitting module according to this embodiment. FIG. 12 is a top view schematically showing the second light-transmitting layer 90 in this embodiment.

[0051] 11 and 12, in the light-emitting module 2 according to this embodiment, the second light-transmitting layer 90 has, on its upper surface 91, a central region 91a having an uneven surface structure and an outer region 91b arranged around the central region 91a and having a smoother surface than the central region 91a. The lower surface 92 of the second light-transmitting layer 90 is entirely smooth. The uneven surface of the central region 91a can be formed using a known method such as blasting or etching. The uneven surface may also be a prismatic surface.

[0052] In a plan view, the outer edge of the central region 91a is located inside the outer edge of the second light-transmitting layer 90 and outside the outer edge of the light-emitting surface 38 on which the multiple light-emitting elements 30 are arranged. In a plan view, the outer edge of the central region 91a may be located outside or inside the inner edge of the spacer 80.

[0053] In this embodiment, the central region 91a of the upper surface 91 of the second light-transmitting layer 90 has an uneven surface, thereby increasing the efficiency of extracting light from the second light-transmitting layer 90. On the other hand, the outer region 91b of the upper surface 91 of the second light-transmitting layer 90 does not have an uneven surface, thereby reducing the first resin 70 from penetrating the outer region 91b into the central region 91a. Other configurations, manufacturing methods, operations, and effects of this embodiment are the same as those of the first embodiment.

[0054] <Third embodiment> FIG. 13 is a cross-sectional view schematically showing the light-emitting module according to this embodiment.

[0055] As shown in FIG. 13 , in the light-emitting module 3 according to this embodiment, the second light-transmitting layer 90 is thicker than that of the light-emitting module 1 according to the first embodiment. Therefore, the second light-transmitting layer 90 is disposed on the first light-transmitting layer 70 so that its upper portion protrudes upward from the first resin 70. In this embodiment, a portion of the side surface of the second light-transmitting layer 90 in the thickness direction, which is continuous with the upper surface 91, may be exposed from the first resin 70, or the entire side surface of the second light-transmitting layer 90 in the thickness direction, which is continuous with the upper surface 91, may be covered with the first resin 70. In particular, it is preferable that almost the entire side surface of the second light-transmitting layer 90 in the thickness direction is covered with the first resin 70. The first resin 70, which covers almost the entire side surface of the second light-transmitting layer 90, is formed by a liquid resin material disposed between the outer resin frame 71 and the structure creeping up the side surface of the second light-transmitting layer 90.

[0056] In this embodiment, by thickening the second light-transmitting layer 90, it is possible to enhance the effect of protecting the light-emitting element 30 and the effect of separating foreign matter from the light-emitting element 30 when the foreign matter adheres to the upper surface 91 of the second light-transmitting layer 90. Other than the above, the configuration, manufacturing method, operation, and effects of this embodiment are the same as those of the first embodiment.

[0057] The above-described embodiments are examples of realizing the present invention, and the present invention is not limited to these embodiments. For example, the present invention also includes embodiments in which some components or steps are added, deleted, or modified in the above-described embodiments. Furthermore, the above-described embodiments can be implemented in combination with each other.

[0058] The embodiments include the following aspects.

[0059] (Appendix 1) a first wiring substrate; a plurality of light-emitting elements arranged on the first wiring substrate; a first transparent layer covering the plurality of light-emitting elements; a spacer disposed on the first light-transmitting layer; a second light-transmitting layer disposed on the spacer; Equipped with an air layer is disposed between the first light-transmitting layer and the second light-transmitting layer; A light-emitting module in which the spacer does not overlap at least one light-emitting element of the plurality of light-emitting elements in a plan view.

[0060] (Appendix 2) 2. The light-emitting module according to claim 1, wherein, in a plan view, the spacer has a frame shape surrounding the plurality of light-emitting elements.

[0061] (Appendix 3) 3. The light-emitting module according to claim 1, wherein, in a plan view, an outer edge of the spacer coincides with an outer edge of the second light-transmitting layer.

[0062] (Appendix 4) 4. The light-emitting module according to claim 1, wherein the spacer is in contact with the first light-transmitting layer.

[0063] (Appendix 5) 5. The light-emitting module according to claim 1, wherein the spacer includes a resin and the second light-transmitting layer includes glass.

[0064] (Appendix 6) 6. The light-emitting module according to claim 1, further comprising a first resin covering at least a part of a side surface of the second light-transmitting layer and a side surface of the spacer.

[0065] (Appendix 7) Further comprising a second wiring substrate; the first wiring substrate is disposed on the second wiring substrate, 7. The light-emitting module according to claim 6, wherein the first resin covers a part of an upper surface of the first wiring substrate and a part of an upper surface of the second wiring substrate.

[0066] (Appendix 8) 8. The light-emitting module according to claim 7, further comprising a wire disposed in the first resin and connecting the first wiring board and the second wiring board.

[0067] (Appendix 9) 9. The light-emitting module according to claim 6, wherein an upper end of the first resin is at the same level as or lower than an upper surface of the second light-transmitting layer.

[0068] (Appendix 10) 10. The light-emitting module according to claim 1, wherein the first light-transmitting layer is in contact with the first wiring substrate. [Industrial Applicability]

[0069] The embodiments of the present invention can be used, for example, in light sources such as vehicle headlights or display devices. [Explanation of symbols]

[0070] 1, 2, 3: Light-emitting modules 10: Second wiring board 10a:Top surface 10b: Bottom surface 11: Base 12: 2nd terminal 13: Bottom pad 14: Heat dissipation part 15: Joint material 20: First wiring board 21:Top surface 22: 1st terminal 30: Light emitting element 38: Light-emitting surface 40: Second resin 50: 1st transparent layer 60: Wire 70: First resin 71: Outer resin frame 73: Protective resin 80: Spacer 80a: Resin film 80b: Resin frame 90: Second transparent layer 90a: Glass substrate 91:Top surface 91a: Central area 91b: External area 92: Bottom surface 100: Air layer 201: Nozzle 202: Mask 203: Nozzle

Claims

1. A first wiring board; A plurality of light emitting elements arranged on the first wiring substrate; a first transparent layer covering the plurality of light emitting elements; A spacer disposed on the first light-transmitting layer; A second light-transmitting layer disposed on the spacer; a first resin covering at least a portion of a side surface of the second light transmitting layer and a side surface of the spacer; Equipped with an air layer is disposed between the first light-transmitting layer and the second light-transmitting layer, In a plan view, the plurality of light emitting elements are arranged in a matrix, In a plan view, the spacer has a frame shape surrounding the plurality of light-emitting elements, In a plan view, the spacer does not overlap any of the plurality of light-emitting elements, an upper end of the first resin is at the same level as or lower than an upper surface of the second light transmitting layer; A light-emitting module in which an upper surface of the first resin is displaced downward as it moves away from the second light-transmitting layer.

2. The light emitting module according to claim 1 , wherein an outer edge of the spacer coincides with an outer edge of the second light transmissive layer in a plan view.

3. The light-emitting module according to claim 1 , wherein the spacer is in contact with the first light-transmitting layer.

4. The light emitting module according to claim 1 , wherein the spacer includes a resin, and the second light transmissive layer includes a glass.

5. The light emitting module according to claim 1 , wherein the first resin has light reflectivity.

6. Further comprising a second wiring substrate; the first wiring board is disposed on the second wiring board, The light emitting module according to claim 1 , wherein the first resin covers a part of an upper surface of the first wiring substrate and a part of an upper surface of the second wiring substrate.

7. The light emitting module according to claim 6 , further comprising a wire disposed in the first resin and connecting the first wiring board and the second wiring board.

8. The light emitting module according to claim 1 , wherein the first light transmitting layer is in contact with the first wiring substrate.

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