Light-emitting module

Abstract

To provide a light-emitting module having high light extraction efficiency.SOLUTION: A light-emitting module 1 includes a wiring substrate 20, a plurality of light-emitting elements 30 each having an upper surface 31, a lower surface 32, and side surfaces 33, the light-emitting elements 30 being mounted on the wiring substrate 20 such that the lower surfaces 32 face the upper surface 31 of the wiring substrate 20, the light-emitting module 1 being disposed between the upper surface 31 of the wiring substrate 20 and the lower surfaces 31 of the light-emitting elements 30 and between the side surfaces of adjacent light-emitting elements 30. And a second resin 50 covering the upper surface 31 of the light emitting element 30 and the upper surface 31 of the first resin 40 and containing a fluorescent material 52, wherein an upper portion of the first resin 40 has a removed surface removed by being sprayed with solid carbon dioxide 500, the upper surface 31 of the first resin 40 is located between the upper surface 31 and the lower surface 32 of the light emitting element 30 between adjacent light emitting elements, and the lateral surface 33 of the light emitting element 30 exposed from the first resin 40 is covered with the second resin 50.SELECTED DRAWING: Figure 5A

Description

[Technical Field]

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

[0002] In recent years, light-emitting modules have been proposed that mount numerous light-emitting elements on a single wiring board and control each element individually. In such light-emitting modules, there is a need to improve the light extraction efficiency of each individual light-emitting element. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-74005 [Overview of the project] [Problems that the invention aims to solve]

[0004] The embodiment aims to provide a light-emitting module with high light extraction efficiency. [Means for solving the problem]

[0005] A method for manufacturing a light-emitting module according to an embodiment includes the steps of: preparing a wiring board on which a plurality of light-emitting elements are placed on its upper surface; placing a first resin containing a light-reflective material outside the region on the upper surface of the wiring board on which the plurality of light-emitting elements are placed; spreading the first resin in the region so that the first resin is placed between the wiring board and the light-emitting elements, and covering the upper surfaces of the plurality of light-emitting elements with the first resin; and removing the first resin from the upper surface of the light-emitting elements by blowing solid carbon dioxide onto the upper surface of the first resin.

[0006] The light-emitting module according to the embodiment comprises a wiring board, a plurality of light-emitting elements mounted on the wiring board, a first resin containing a light-reflective material, and a second resin containing a phosphor that covers the upper surface of the light-emitting elements and the upper surface of the first resin. Each light-emitting element has an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface that slopes so as to widen from the lower surface toward the upper surface. The lower surface of the light-emitting element faces the upper surface of the wiring board. The first resin is arranged between the upper surface of the wiring board and the lower surface of the light-emitting elements, and between the side surfaces of adjacent light-emitting elements. Between adjacent light-emitting elements, the upper surface of the first resin is located between the upper and lower surfaces of the light-emitting elements in the direction toward the second resin from the wiring board. The side surfaces of the light-emitting elements exposed from the first resin are covered with the second resin. [Effects of the Invention]

[0007] According to this embodiment, a light-emitting module with high light extraction efficiency can be realized. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view from diagonally above showing a light-emitting module according to an embodiment. [Figure 2] Figure 2 is a perspective view taken from a diagonal downward side, showing the light-emitting module according to the embodiment. [Figure 3] Figure 3 is an enlarged plan view showing region III in Figure 1. [Figure 4] Figure 4 is a cross-sectional view taken along the line IV-IV shown in Figure 1. [Figure 5A] Figure 5A is an enlarged cross-sectional view showing region VA in Figure 4. [Figure 5B] Figure 5B is an enlarged cross-sectional view showing region VB in Figure 5A. [Figure 6A] Figure 6A is a cross-sectional view showing a method for manufacturing a light-emitting module according to an embodiment. [Figure 6B] Figure 6B is a cross-sectional view showing a method for manufacturing a light-emitting module according to an embodiment. [Figure 6C] FIG. 6C is a cross-sectional view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 7A] FIG. 7A is a cross-sectional view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 7B] FIG. 7B is a cross-sectional view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 7C] FIG. 7C is a cross-sectional view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 8A] FIG. 8A is a plan view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 8B] FIG. 8B is a plan view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 9] FIG. 9 is a perspective view showing a nozzle used in an embodiment. [Figure 10A] FIG. 10A is an enlarged cross-sectional view showing a method of manufacturing a light-emitting module according to an embodiment. [Figure 10B] FIG. 10B is an enlarged cross-sectional view showing a method of manufacturing a light-emitting module according to an embodiment. MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. Since each drawing schematically shows an embodiment, the size, interval, positional relationship, etc. of each member may be exaggerated, a part of the member may be omitted, or an end view showing only a cut surface as a cross-sectional view may be used. In each drawing, the same reference numerals are assigned to the same configurations.

[0010] <Configuration> First, the configuration of the light-emitting module according to the embodiment will be described. FIG. 1 is a perspective view of the light-emitting module according to the present embodiment as viewed obliquely from above. FIG. 2 is a perspective view of the light-emitting module according to the present embodiment as viewed obliquely from below. FIG. 3 is an enlarged plan view showing region III of FIG. 1. Figure 4 is a cross-sectional view taken along the line IV-IV shown in Figure 1. Figure 5A is an enlarged cross-sectional view showing region VA in Figure 4. Figure 5B is an enlarged cross-sectional view showing region VB in Figure 5A.

[0011] As shown in Figures 1 and 2, the light-emitting module 1 according to this embodiment comprises a package substrate 10, a wiring substrate 20, a plurality of light-emitting elements 30, a first resin 40, a second resin 50, a plurality of wires 60, and a third resin 70. In Figure 1, for the sake of illustration, a portion of the third resin 70 and a portion of the second resin 50 are omitted, and a portion of the wires 60 and a portion of the light-emitting elements 30 are made visible.

[0012] The light-emitting module 1 preferably comprises a large number of small light-emitting elements 30, with many of these small elements densely arranged on the wiring board 20 at a narrow pitch. This allows the illumination range to be controlled by a larger number of divisions, making it usable as a light source for a high-resolution lighting system. For example, when the light-emitting module 1 is used in an adaptive driving beam (ADB) headlamp of a car, the light distribution can be controlled to a high degree, and light with higher definition and resolution can be emitted.

[0013] The package substrate 10 includes, for example, a flat substrate 11 and wiring arranged on at least the upper surface of the substrate 11. The substrate 11 is preferably made of a material with high heat dissipation properties, and more preferably a material with high light-shielding properties and strength. Specifically, examples include metals such as aluminum (Al) and copper (Cu), ceramics such as alumina, aluminum nitride, and mullite, resins such as phenolic resin, epoxy resin, polyimide resin, BT resin (bismaleimide triazine resin), and polyphthalamide (PPA), as well as composite materials composed of resin and metal or ceramics. The package substrate 10 may be flat, or it may have a structure with a cavity on its upper surface for housing the wiring substrate 20. Examples of wiring materials include metals or alloys thereof such as copper (Cu), silver (Ag), gold (Au), aluminum (Al), platinum (Pt), titanium (Ti), tungsten (W), palladium (Pd), iron (Fe), and nickel (Ni).

[0014] As an example, the package substrate 10 is constructed by laminating insulating material such as epoxy resin onto a metallic base such as Al or Cu, with wiring arranged on the surface and inside. Some of the wiring forms a plurality of upper surface pads 12 on the upper surface 10a of the package substrate 10, and other parts of the wiring form a plurality of lower surface pads 13 on the lower surface 10b of the package substrate 10.

[0015] In this specification, for the sake of explanation, the XYZ Cartesian coordinate system is used. The longitudinal direction of the package substrate 10 is defined as the "X direction," the transverse direction as the "Y direction," and the thickness direction as the "Z direction." Within the Z direction, the direction from the bottom surface 10b of the package substrate 10 toward the top surface 10a is also referred to as "up," and the opposite direction is also referred to as "down," but this expression is for convenience only and is unrelated to the direction of gravity.

[0016] Furthermore, a metal base is exposed from the insulating material on the upper surface 10a and lower surface 10b of the package substrate 10, forming a heat dissipation section 14. In a plan view, the heat dissipation section 14 is located in the center of the package substrate 10, and multiple upper pads 12 and lower pads 13 are arranged on both sides of the heat dissipation section 14, flanking it. The upper pads 12 and lower pads 13 are arranged, for example, along the long side of the package substrate 10.

[0017] The wiring board 20 is placed on the heat dissipation section 14 of the package board 10. The wiring board 20 is, for example, a silicon substrate with an integrated circuit built in, for example, an Application Specific Integrated Circuit (ASIC) substrate. The lower surface of the wiring board 20 is bonded to the upper surface of the heat dissipation section 14 via a bonding member. Examples of bonding members include silicone silver paste. The central part of the upper surface 21 of the wiring board 20 is provided as a region 38 on which a light-emitting element is placed, and a first pad connected to the light-emitting element 30 is provided therein, while a second pad electrically connected to the first pad is provided around it.

[0018] The wire 60 is a component for electrically connecting the package substrate 10 and the wiring board 20. The wire 60 is connected to the top pad 12 of the package substrate 10 and the second pad of the wiring board 20. For example, the wire 60 may be made of gold (Au). For example, the number of wires 60 is the same as the number of top pads 12.

[0019] As shown in Figures 1, 3 to 5B, multiple light-emitting elements 30 are placed in the center of the upper surface 21 of the wiring board 20. The light-emitting elements 30 have a roughly rectangular shape when viewed from above. The multiple light-emitting elements 30 are arranged, for example, in a matrix. In one example, there are four segments, each with a roughly square upper surface and arranged in 64 rows and 64 columns, for a total of 16,384 light-emitting elements 30. In one example, the arrangement period of the light-emitting elements 30 is 50 μm, and each light-emitting element 30 is roughly square with sides of 45 μm. Therefore, the distance between adjacent light-emitting elements 30 is 5 μm. The light-emitting elements 30 are connected to the first pad on the upper surface 21 of the wiring board 20. The light-emitting elements 30 are, for example, light-emitting diodes (LEDs) that emit, for example, blue light.

[0020] The size of the light-emitting element 30 in the light-emitting module 1 is preferably approximately rectangular with sides of 20 μm to 100 μm when viewed from above, and more preferably approximately rectangular with sides of 30 μm to 100 μm, taking into consideration the mounting accuracy of the light-emitting element 30 and the high resolution of the module. Furthermore, the number of light-emitting elements 30 in the light-emitting module 1 is preferably 5,000 to 100,000, and more preferably 15,000 to 30,000, taking into consideration the miniaturization and high resolution of the light-emitting module.

[0021] The distance between adjacent light-emitting elements 30 is preferably narrower in order to achieve high resolution of the light-emitting module 1. Furthermore, considering the efficient arrangement of the first resin 40, which will be described later, the distance between adjacent light-emitting elements 30 is preferably 2 μm or more and 10 μm or less, and more preferably 3 μm or more and 7 μm or less.

[0022] Furthermore, the light-emitting element 30 can be selected to emit light of any wavelength. For example, for light-emitting elements that emit blue or green light, elements using ZnSe, nitride semiconductors (InXAlYGa1-X-YN, 0≦X, 0≦Y, X+Y≦1), or GaP can be selected. For light-emitting elements 30 that emit red light, semiconductors represented by GaAlAs and AlInGaP can be suitably used. In addition, semiconductor light-emitting elements made of materials other than those listed above can also be used. The composition and emission color of the light-emitting element 30 can be appropriately selected according to the purpose.

[0023] As shown in Figure 5A, the light-emitting element 30 has an upper surface 31, a lower surface 32 opposite to the upper surface 31, and a side surface 33 positioned between the upper surface 31 and the lower surface 32. The side surface 33 is inclined to widen from the lower surface 32 toward the upper surface 31. The upper surface 31 and lower surface 32 of the light-emitting element 30 are, for example, rectangular in plan view, and the side surface 33 is provided on four sides that are continuous with the upper surface 31 and the lower surface 32. That is, the shape of the light-emitting element 30 is approximately an inverted truncated square pyramid. The lower surface 32 of the light-emitting element 30 faces the upper surface 21 of the wiring board 20. The light-emitting element 30 is connected to the first pad via a conductive bonding material 39. For this reason, the lower surface 32 of the light-emitting element 30 is separated from the upper surface 21 of the wiring board 20. The bonding material 39 may be, for example, copper (Cu). The bonding material 39 can be formed, for example, by an electroplating method.

[0024] The first resin 40 is light-reflective and is positioned between the upper surface 21 of the wiring board 20 and the lower surface 32 of the light-emitting element 30, and between the opposing side surfaces 33 of adjacent light-emitting elements 30. In other words, the first resin 40 exposes the upper surface of the light-emitting element 30 and covers the lower part of the side surface 33 and the lower surface 32 of the light-emitting element. This allows more of the light emitted from the light-emitting element 30 to be extracted from the upper surface 21. The first resin 40 comprises a base material 41 made of a light-transmitting resin and a light-reflective substance 42 contained in the base material 41. By increasing the content of the light-reflective substance 42 in the first resin 40, the efficiency of light extraction from the light-emitting element 30 can be increased. The concentration of the light-reflective substance 42 in the first resin 40 is preferably 50% by mass or more and 70% by mass or less, for example, about 60% by mass.

[0025] As the translucent resin of the base material 41, for example, silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, and hybrid resins containing at least one of these resins can be used. Among these, it is preferable to use a silicone resin which has excellent heat resistance and light resistance, and it is even more preferable to use a dimethyl silicone resin. Dimethyl silicone resin has superior reliability in terms of high temperature resistance and other factors, so it can be suitably used as a material for automotive applications.

[0026] Suitable light-reflecting materials include, for example, titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass fillers. As an example, the base material 41 is dimethyl silicone resin, and the light-reflecting material is titanium oxide. The appearance color of the first resin 40 is white.

[0027] The second resin 50 has translucency and covers the upper surface 31 of the light-emitting element 30 and the upper surface 43 of the first resin 40. The second resin 50 is in contact with the upper surface 31 of the light-emitting element 30, the upper part of the side surface 33, and the upper surface 43 of the first resin 40. Here, the upper and lower parts of the side surface 33 are, for example, regions on the upper surface side and the lower surface side in the height direction from the upper surface 31 to the lower surface 32 on the side surface 33. The second resin 50 includes at least a base material 51 made of a translucent resin, and the base material 51 may contain a phosphor 52 therein.

[0028] As the base material 51, the same material as the base material 41 of the first resin 40 described above can be used. As the phosphor 52, yttrium aluminum garnet-based phosphors (for example, Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet-based phosphors (for example, Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet-based phosphors (for example, Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphors (for example, Ca 10 (PO4)6Cl2:Eu), SAE-based phosphors (for example, Sr4Al 14 O 25 :Eu), chlorosilicate-based phosphors (for example, Ca8MgSi4O 16 Cl2:Eu), β-sialon-based phosphors (for example, (Si,Al)3(O,N)4:Eu), α-sialon-based phosphors (for example, Ca(Si,Al) 12 (O,N) 16 :Eu), SLA-based phosphors (for example, SrLiAl3N4:Eu), CASN-based phosphors (for example, CaAlSiN3:Eu) or SCASN-based phosphors (for example, (Sr,Ca)AlSiN3:Eu) and other nitride-based phosphors, KSF-based phosphors (for example, K2SiF6:Mn), KSAF-based phosphors (for example, K2(Si,Al)F6:Mn) or MGF-based phosphors (for example, 3.5MgO·0.5MgF2·GeO2:Mn) and other fluoride-based phosphors, phosphors having a perovskite structure (for example, CsPb(F,Cl,Br,I)3), or quantum dot phosphors (for example, CdSe, InP, AgInS2 or AgInSe2) and the like can be used.

[0029] As shown in Figure 5B, between adjacent light-emitting elements 30, the upper surface 43 of the first resin 40 is located between the upper surface 31 and the lower surface 32 of the light-emitting element 30 in the Z direction, that is, in the direction in which the wiring board 20 and the second resin 50 face each other. As a result, the lower part of the side surface 33 of the light-emitting element 30 is covered by the first resin 40, and the upper part is covered by the second resin 50. In other words, the light-emitting module 1 has a recess between adjacent light-emitting elements 30 defined by the side surface 33 of the light-emitting element 30 and the upper surface 43 of the first resin 40, and the second resin 50 is placed in this recess.

[0030] The third resin 70 protects the wires connecting the package substrate 10 and the wiring board 20. The third resin 70 has a rectangular frame shape in plan view, along the outer edge of the wiring board 20. The third resin 70 is positioned from the top surface of the package substrate 10 to the top surface of the wiring board 20, covering the top surface pad 12 of the package substrate 10, the wires 60, and the external connection pads of the wiring board 20.

[0031] As shown in Figure 4, the third resin 70 includes an outer resin frame 71 provided on the package substrate 10, an inner resin frame 72 provided on the wiring board 20, and a protective resin 73 provided between the outer resin frame 71 and the inner resin frame 72. The third resin 70 may be light-transmitting or light-shielding. The third resin 70 includes a base material made of at least a light-transmitting resin, and the base material may contain a light-reflective substance and / or a light-absorbing substance. As the base material, the same material as the base material 41 of the first resin 40 described above can be used. As the light-reflective substance, the same material as the light-reflective substance of the first resin 40 described above can be used. Examples of light-absorbing substances include carbon black and graphite.

[0032] In one example, the outer resin frame 71 and the inner resin frame 72 are translucent, while the protective resin 73 is light-reflective (light-blocking). The appearance of the protective resin 73 is, for example, white, black, or gray. Furthermore, the first resin 40, the second resin 50, and the third resin 70 may each contain, as necessary, colorants, light diffusing agents, fillers to adjust viscosity, etc.

[0033] <Manufacturing method> Next, a method for manufacturing the light-emitting module 1 according to this embodiment will be described. Figures 6A to 6C and 7A to 7C are cross-sectional views showing the manufacturing method of the light-emitting module according to this embodiment. Figures 8A and 8B are plan views showing the manufacturing method of the light-emitting module according to this embodiment. Figure 9 is a perspective view showing the nozzle used in this embodiment. Figures 10A and 10B are enlarged cross-sectional views showing a method for manufacturing a light-emitting module according to this embodiment. Note that in Figures 6A to 7C, the number of light-emitting elements 30 is depicted as fewer than the actual number in order to simplify the diagrams.

[0034] (Steps to prepare the wiring board 20) First, a wiring board 20 is prepared as shown in Figure 6A. Next, multiple light-emitting elements 30 are placed on the central part of the upper surface 21 of the wiring board 20, excluding the peripheral area. Each of the multiple light-emitting elements 30 is bonded to the wiring board 20 via a bonding material 39. A resist film 101 is placed on the peripheral area of ​​the upper surface 21 of the wiring board 20. The resist film 101 is placed on the wiring board 20 so as to surround the area 38 on which the multiple light-emitting elements 30 are placed. The shape of the resist film 101 is, for example, a rectangular frame, and the thickness of the resist film 101 is approximately the same as the combined thickness of the bonding material 39 and the light-emitting elements 30. In this way, a wiring board 20 with the resist film 101 and multiple light-emitting elements 30 placed on its upper surface 21 is prepared.

[0035] (Step of placing the first resin 40) Next, as shown in Figures 6B and 8A, an uncured first resin 40 is placed outside the region 38 on the upper surface 21 of the wiring board 20 where the multiple light-emitting elements 30 are placed. As described above, the first resin 40 contains a light-reflective substance 42 in a base material 41 made of a translucent resin. For example, the shape of the region 38 is rectangular in plan view, and the first resin 40 is placed on the resist film 101 on one side of the region 38 in the Y direction, along the long side of the region 38. The length of the first resin 40 in the X direction is greater than or equal to the length L of the long side of the region 38.

[0036] Here, the first resin 40 contains a high concentration of light-reflective material as described above. For this reason, the uncured first resin 40 placed on the wiring board 20 is less likely to wet and spread on the wiring board 20, and its shape is easily maintained. For example, the viscosity of the first resin 40 placed on the upper surface of the wiring board 20 is preferably 50 Pa·s or more and less than 200 Pa·s at room temperature (20±5℃). This suppresses unintended spreading into the region 38 when the first resin 40 is placed on the wiring board 20, and makes it easier to control the movement of the first resin into the region 38 in the coating process with the first resin described later.

[0037] (Step of coating with the first resin 40) Next, the uncured first resin 40 is spread into region 38, thereby positioning the first resin 40 between the wiring board 20 and the light-emitting element 30. At this time, the upper surfaces of the multiple light-emitting elements 30 are also covered with the first resin. Then, as the first resin 40 flows through the gaps between adjacent light-emitting elements 30, the sides of the light-emitting elements 30 are covered with the first resin.

[0038] More specifically, a nozzle 200 having an opening of width W is prepared, as shown in Figure 9. The shape of the opening of the nozzle 200 (opening shape) is rectangular, and its width W is greater than or equal to the length L of the long side of the region 38.

[0039] Next, as shown in Figures 6C and 10A, the nozzle 200 is moved in the Y direction, that is, in the direction in which the shorter side of region 38 extends, while spraying the gas 300 from the nozzle 200 almost perpendicularly toward the upper surface of the wiring board 20. By spraying the gas 300 onto the upper surface 21 of the wiring board 20 in this way, the uncured first resin 40 is spread along the Y direction. This movement of the nozzle 200 may be repeated, for example, multiple times. As a result, the first resin 40 can be spread throughout region 38, as shown in Figure 8B.

[0040] At this time, the first resin 40 moves along the upper surface 31 of the light-emitting element 30 in the Y direction, enters the gap between adjacent light-emitting elements 30, and further enters the gap between the wiring board 20 and the light-emitting elements 30. By spraying the gas 300 from the nozzle 200 almost perpendicularly toward the upper surface of the wiring board 20, and slowly moving the nozzle 200 along one direction, the generation of voids in the first resin 40 expanded into region 38 can be suppressed.

[0041] In this embodiment, by blowing gas 300 substantially perpendicularly toward the wiring board 20, the substantially perpendicularly injected gas 300 can be blown onto the first resin 40 along the upper surface of the resist film 101 and / or the wiring board 20. This changes the surface shape of the first resin 40 that was remaining on the resist film 101 due to surface tension, specifically increasing the contact angle between the first resin 40 and the upper surface of the resist film 101, reducing wettability, and allowing it to spread gently in the Y direction. When the first resin 40 that has reached region 38 comes into contact with the light-emitting element 30, the capillary action is used to wet and spread the first resin 40 into the gaps between and beneath the light-emitting elements 30, starting from the contact point.

[0042] By spreading the first resin 40 in this way, the generation of voids can be suppressed. Also, since the thickness of the first resin 40 covering the upper surface of the light-emitting element 30 is reduced, the first resin 40 can be removed more easily in the step of removing the first resin 40 described later. In this way, the first resin 40 is placed between the wiring board 20 and the light-emitting element 30, and between adjacent light-emitting elements 30, and the upper surfaces 31 of the multiple light-emitting elements 30 are covered with the first resin 40. After that, the first resin 40 is cured by, for example, heat treatment. As an example, the thickness of the first resin 40 covering the upper surface of the light-emitting element 30 is about 20 μm. Note that a part of the upper surface of the light-emitting element 30 may be exposed from the first resin 40, but it is preferable that the entire outer edge of the upper surface is covered with the first resin 40.

[0043] In the step of coating with the first resin 40, the movement speed of the nozzle 200 that injects the gas 300 in the Y direction is preferably 0.1 to 0.5 mm / second, for example, preferably 0.2 mm / second. The gas pressure is preferably 0.3 to 0.5 MPa, for example, preferably 0.45 MPa. The number of repetitions of movement of the nozzle 200 is preferably 1 to 5 times, for example, preferably 3 times. The gas 300 is preferably, for example, air, nitrogen gas, or oxygen gas, for example, air.

[0044] (Step to remove the first resin 40) Next, as shown in Figures 7A and 10B, solid carbon dioxide 500 is sprayed from the nozzle 400 onto the upper surface of the first resin 40. The solid carbon dioxide 500 sublimes near the interface between the light-emitting element 30 and the first resin 40, peeling off the portion of the first resin 40 that is positioned on the upper surface 31 of the light-emitting element 30. This allows the first resin 40 to be removed from the upper surface 31 of the light-emitting element 30. At this time, the upper part of the first resin 40 positioned between the light-emitting elements 30 is also removed, exposing the upper part of the side surface 33 of the light-emitting element 30.

[0045] The particle size of the solid carbon dioxide 500 is preferably 5 to 50 μm. The movement speed of the nozzle 400 is preferably 20 to 100 mm / second, for example, preferably 50 mm / second. The pressure at which the solid carbon dioxide 500 is sprayed is preferably 0.1 to 0.35 MPa, for example, preferably 0.3 MPa. The number of times the nozzle 400 moves is preferably 1 to 5 times, for example, 3 times.

[0046] Next, the resist film 101 is removed. The resist film 101 can be removed, for example, by wet etching. As shown in Figure 7B, the intermediate 90, consisting of the wiring substrate 20, multiple light-emitting elements 30, the resist film 101, and the first resin 40, is immersed in the resist stripping solution 102. This allows the resist film 101 to be removed, as shown in Figure 7C.

[0047] (Process of mounting the wiring board 20) Next, as shown in Figures 1 and 4, the wiring board 20 is placed on the package substrate 10. The package substrate 10 can be fixed to the wiring board 20 via a known adhesive member such as metal paste. Examples of adhesive members include silicone silver paste.

[0048] (Step of placing the second resin 50) Next, the uncured or semi-cured second resin 50 is placed on the multiple light-emitting elements 30 and the first resin 40. As described above, the second resin 50 contains a phosphor 52 in the base material 51. The second resin 50 is placed inside the frame-shaped third resin 70, that is, in the region 38 where the multiple light-emitting elements 30 are arranged. The second resin 50 may be placed by spraying, potting, or other methods, or it may be placed in a sheet that has been pre-processed.

[0049] (Process for curing the second resin 50) Next, the second resin 50 is cured by heat treatment. When the second resin 50 is heated to a first temperature, for example 100°C, the second resin 50 liquefies and enters the space above the first resin 40 in the gap between the light-emitting elements 30. This allows the second resin 50 to come into contact with the upper part of the side surface 33 of the light-emitting elements 30. Next, when the second resin 50 is heated to a second curing temperature higher than the first temperature, for example 150°C, the second resin 50 hardens. In this way, the light-emitting module 1 according to this embodiment is manufactured.

[0050] The steps of placing the second resin 50 and curing it may be performed between the peeling step of the resist film 101 shown in Figure 7B and the step of placing the wiring board 20 on the package board 10.

[0051] The manufacturing method of the light-emitting module 1 according to this embodiment may further include steps such as: electrically connecting the wiring board 20 and the package board, connecting the top pad 12 of the package board 10 and the external connection pad of the wiring board 20 with a wire 60; and protecting the wire 60, placing an outer resin frame 71 on the package board 10 and an inner resin frame 72 on the wiring board 20, and placing a protective resin 73 between the outer resin frame 71 and the inner resin frame 72.

[0052] <Effects> In the light-emitting module 1 according to this embodiment, a first resin 40 is placed between the wiring board 20 and the light-emitting element 30. Therefore, light emitted downward from the light-emitting element 30 can be reflected upward. As a result, the light-emitting module 1 has high light extraction efficiency.

[0053] Furthermore, because the concentration of the light-reflective substance 42 in the first resin 40 is high at 50-70% by mass, the light reflectivity of the first resin 40 is high. As a result, the light-emitting module 1 has high light extraction efficiency.

[0054] Furthermore, in the light-emitting module 1, the second resin 50 is in contact with the light-emitting element 30, and there is no adhesive layer or the like interposed between the light-emitting element 30 and the second resin 50. Therefore, the light utilization efficiency is high.

[0055] Furthermore, in the light-emitting module 1, the upper part of the side surface 33 of the light-emitting element 30 is in contact with the second resin 50. By exposing the upper part of the side surface 33 from the first resin 40, the efficiency of light extraction from the light-emitting element 30 is improved. In addition, because the contact area between the light-emitting element 30 and the second resin 50 is large, the adhesion is good.

[0056] Furthermore, according to the manufacturing method of the light-emitting module 1 of this embodiment, by blowing gas toward the upper surface of the wiring board 20 on which the first resin 40 is arranged, the first resin 40 can be reliably arranged between the wiring board 20 and the light-emitting elements 30, and between the light-emitting elements 30, while suppressing the generation of voids. As a result, it becomes possible to arrange the first resin 40 containing a high concentration of light-reflective material in the narrower gaps between the light-emitting elements 30, thereby enabling miniaturization of the light-emitting module 1. In addition, the light reflectivity of the first resin 40 can be improved.

[0057] Furthermore, as shown in Figure 9, the width W of the opening shape of the nozzle 200 is set to be greater than or equal to the longitudinal length L of the region 38. As a result, the first resin 40 moves simultaneously in the short direction of the region 38, allowing it to spread efficiently and uniformly while suppressing the generation of voids.

[0058] Furthermore, by repeatedly moving the nozzle 200, the thickness of the first resin 40 placed on the upper surface 31 of the light-emitting element 30 can be made thinner. This allows the first resin 40 to be removed from the upper surface 31 of the light-emitting element 30 by blowing solid carbon dioxide. Because solid carbon dioxide is soft, it is less likely to damage the light-emitting element 30, and the first resin 40 can be easily peeled off by sublimation near the interface between the light-emitting element 30 and the first resin 40. In addition, by blowing solid carbon dioxide, the upper part of the first resin 40 placed between the light-emitting elements 30 can also be removed, exposing the upper part of the side surface 33 of the light-emitting element 30.

[0059] The embodiments described above are examples that embody the present invention, and the present invention is not limited to these embodiments. For example, the present invention also includes the addition, deletion, or modification of some components or processes in the embodiments described above. [Industrial applicability]

[0060] The present invention can be used, for example, as a light source for vehicle headlights and display devices. [Explanation of symbols]

[0061] 1: Light-emitting module 10: Package substrate 10a:Top surface 10b: Bottom surface 11: Base 12: Top pad 13: Bottom pad 14: Heat dissipation part 20: Wiring board 21:Top surface 30: Light-emitting element 31:Top surface 32: Bottom surface 33: Side view 38: Area 39: Bonding material 40: First resin 41: Base material 42: Light reflective material 43:Top surface 50: Second resin 51: Base material 52: Phosphor 60: Wire 70: Third resin 71: Outer resin frame 72: Inner resin frame 73: Protective resin 90: Intermediate 101: Resist film 102: Resist stripping solution 200: Nozzle 300: Gas 400: Nozzle 500: Solid carbon dioxide L: Length W: Width

Claims

1. Wiring board and A plurality of light-emitting elements are placed on the wiring board, having an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, with the lower surface facing the upper surface of the wiring board. Displaced between the upper surface of the wiring board and the lower surface of the light-emitting element, and between the side surfaces of adjacent light-emitting elements, is a first resin containing a light-reflective material, The upper surface of the light-emitting element and the upper surface of the first resin are covered with a second resin containing a phosphor, Equipped with, The upper part of the first resin has a removal surface from which a portion has been removed by spraying solid carbon dioxide, A light-emitting module in which, between adjacent light-emitting elements, the upper surface of the first resin is located between the upper and lower surfaces of the light-emitting elements, and the side surface of the light-emitting element exposed from the first resin is covered with the second resin.

2. The light-emitting module according to claim 1, wherein the side surface of the light-emitting element is inclined to widen from the lower surface toward the upper surface.

3. The light-emitting module according to claim 1 or 2, wherein the number of the plurality of light-emitting elements is 5,000 or more and 100,000 or less.

4. A headlight for a vehicle comprising the light-emitting module described in any one of claims 1 to 3.

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