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 multiple light-emitting elements on a single wiring board and individually control the light-emitting elements. In such light-emitting modules, there is a demand for improving the light extraction efficiency of each light-emitting element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-74005 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the embodiment is 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 having a plurality of light-emitting elements mounted on its upper surface, placing a first resin containing a light-reflective material on the upper surface of the wiring board outside the area where the plurality of light-emitting elements are mounted, spreading the first resin over the area to position the first resin between the wiring board and the light-emitting elements and to coat 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 spraying solid carbon dioxide onto the upper surface of the first resin.

[0006] A light-emitting module according to an embodiment includes 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, which coats the upper surfaces of the light-emitting elements and the upper surface of the first resin. The light-emitting elements have an upper surface, a lower surface opposite the upper surface, and a side surface between the upper surface and the lower surface that slopes 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 disposed 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. 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 from the wiring board toward the second resin. 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 the embodiment, a light emitting module with high light extraction efficiency can be realized. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a light emitting module according to an embodiment, as viewed obliquely from above. [Figure 2] FIG. 2 is a perspective view showing the light emitting module according to the embodiment, as viewed obliquely from below. [Figure 3] FIG. 3 is an enlarged plan view showing region III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. [Figure 5A] FIG. 5A is an enlarged cross-sectional view showing area VA in FIG. [Figure 5B] FIG. 5B is an enlarged cross-sectional view showing region VB of FIG. 5A. [Figure 6A] FIG. 6A is a cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment. [Figure 6B] FIG. 6B is a cross-sectional view showing a method for manufacturing the light emitting module according to the embodiment. [Figure 6C] FIG. 6C is a cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment. [Figure 7A] FIG. 7A is a cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment. [Figure 7B] FIG. 7B is a cross-sectional view showing a method for manufacturing the light emitting module according to the embodiment. [Figure 7C] FIG. 7C is a cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment. [Figure 8A] FIG. 8A is a plan view showing a method for manufacturing a light emitting module according to an embodiment. [Figure 8B] FIG. 8B is a plan view showing a method for manufacturing the light emitting module according to the embodiment. [Figure 9] FIG. 9 is a perspective view showing a nozzle used in the embodiment. [Figure 10A] FIG. 10A is an enlarged cross-sectional view showing a method for manufacturing a light-emitting module according to an embodiment. [Figure 10B] FIG. 10B is an enlarged cross-sectional view showing a method for manufacturing the light-emitting module according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes the embodiments with reference to the drawings. Each drawing is a schematic representation of the embodiment, and therefore the size, spacing, or positional relationship of each component may be exaggerated, some components may be omitted, or end views showing only the cut surface may be used as cross-sectional views. Note that the same reference numerals are used for the same components in each drawing.

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

[0011] 1 and 2, the light-emitting module 1 according to this embodiment includes 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. For convenience of illustration, part of the third resin 70 and part of the second resin 50 are omitted in Fig. 1, and part of the wires 60 and part of the light-emitting elements 30 are visualized.

[0012] The light-emitting module 1 preferably includes a large number of small light-emitting elements 30 as the plurality of light-emitting elements 30, and more small light-emitting elements 30 are densely arranged at a narrow pitch on the wiring substrate 20. This allows the illumination range to be controlled with a larger number of divisions, and the light-emitting module 1 can be used as a light source for a high-resolution illumination system. For example, when the light-emitting module 1 is used in an adaptive driving beam (ADB) headlamp for a vehicle, the light distribution can be highly controlled, and light with higher definition and resolution can be emitted.

[0013] The package substrate 10 includes, for example, a flat base 11 and wiring disposed on at least the upper surface of the base 11. The base 11 is preferably made of a material with high heat dissipation properties, and more preferably a material with high light-shielding properties and strength. Specific examples of the material 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), and composites of resin and metal or ceramic. The package substrate 10 may be flat, or may have a structure with a cavity on the upper surface for accommodating the wiring substrate 20. 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), and nickel (Ni), as well as alloys thereof.

[0014] As an example, the package substrate 10 has an insulating member such as epoxy resin laminated on a metallic base such as Al or Cu, and has wiring arranged on the surface and inside thereof. 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] For ease of explanation, this specification uses an XYZ Cartesian coordinate system. The longitudinal direction of the package substrate 10 is referred to as the "X direction," the lateral direction as the "Y direction," and the thickness direction as the "Z direction." Within the Z direction, the direction from the bottom surface 10b toward the top surface 10a of the package substrate 10 is also referred to as "up," and the opposite direction as "down," but these expressions are also for convenience and are unrelated to the direction of gravity.

[0016] Furthermore, on the top surface 10a and bottom surface 10b of the package substrate 10, a metal base is exposed from the insulating member to form 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 top surface pads 12 and multiple bottom surface pads 13 are located on both sides of the heat dissipation section 14, sandwiching the heat dissipation section 14. The top surface pads 12 and bottom surface pads 13 are arranged, for example, along the long sides of the package substrate 10.

[0017] The wiring board 20 is disposed on the heat dissipation section 14 of the package substrate 10. The wiring board 20 is, for example, a silicon substrate with an integrated circuit built in, such as an application specific integrated circuit (ASIC) board. The lower surface of the wiring board 20 is bonded to the upper surface of the heat dissipation section 14 via a bonding material. An example of the bonding material is silicone silver paste. A first pad connected to the light emitting element 30 is provided in the center of the upper surface 21 of the wiring board 20 as an area 38 where the light emitting element 30 is mounted, and second pads electrically connected to the first pads are provided in the peripheral area.

[0018] The wires 60 are members for electrically connecting the package substrate 10 and the wiring substrate 20. The wires 60 are connected to the upper surface pads 12 of the package substrate 10 and the second pads of the wiring substrate 20. The wires 60 may be made of gold (Au), for example. For example, the number of wires 60 is the same as the number of upper surface pads 12.

[0019] As shown in FIGS. 1 and 3 to 5B, a plurality of light-emitting elements 30 are mounted in the center of the upper surface 21 of the wiring substrate 20. The light-emitting elements 30 have a substantially rectangular shape when viewed from above. The plurality of light-emitting elements 30 are arranged, for example, in a matrix. In one example, four segments are provided, each of which has a substantially square upper surface and is 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 has a substantially square shape with a side length of 45 μm. Therefore, the distance between adjacent light-emitting elements 30 is 5 μm. The light-emitting elements 30 are connected to first pads on the upper surface 21 of the wiring substrate 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 elements 30 included in the light emitting module 1 is preferably a substantially rectangular shape with a side length of 20 μm to 100 μm when viewed from above, taking into consideration the mounting accuracy of the light emitting elements 30 and high definition of the module. Furthermore, the number of light emitting elements 30 included in the light emitting module 1 is preferably 5,000 to 100,000, more preferably 15,000 to 30,000, taking into consideration the miniaturization and high definition of the light emitting module.

[0021] The distance between adjacent light-emitting elements 30 is preferably narrower in order to achieve higher definition in the light-emitting module 1. Furthermore, in consideration of efficient arrangement of the first resin 40 described below, 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] The light-emitting element 30 can be selected to emit light of any wavelength. For example, a light-emitting element using ZnSe, a nitride semiconductor (InXAlYGa1-X-YN, 0≦X, 0≦Y, X+Y≦1), or GaP can be selected to emit blue or green light. Furthermore, a semiconductor represented by GaAlAs or AlInGaP can be suitably used to emit red light. Furthermore, a semiconductor light-emitting element made of a material other than these can also be used. The composition and emitted color of the light-emitting element 30 to be used can be appropriately selected depending on the purpose.

[0023] As shown in FIG. 5A , the light-emitting element 30 has an upper surface 31, a lower surface 32 opposite the upper surface 31, and side surfaces 33 disposed between the upper surface 31 and the lower surface 32. The side surfaces 33 are inclined so as to widen from the lower surface 32 toward the upper surface 31. The upper surface 31 and the lower surface 32 of the light-emitting element 30 are, for example, rectangular in plan view, and the four side surfaces 33 are provided so as to be continuous with the upper surface 31 and the lower surface 32. That is, the shape of the light-emitting element 30 is a substantially inverted trapezoidal pyramid. The lower surface 32 of the light-emitting element 30 faces the upper surface 21 of the wiring substrate 20. The light-emitting element 30 is connected to the first pad via a conductive bonding material 39. Therefore, the lower surface 32 of the light-emitting element 30 is spaced apart from the upper surface 21 of the wiring substrate 20. The bonding material 39 can be, for example, copper (Cu). The bonding material 39 can be formed, for example, by electrolytic plating.

[0024] The first resin 40 is optically reflective and is disposed between the upper surface 21 of the wiring substrate 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 surface 32 and the lower portion of the side surface 33 of the light-emitting element 30. This allows more light emitted from the light-emitting element 30 to be extracted from the upper surface 21. The first resin 40 includes a base material 41 made of a translucent resin and a light-reflecting substance 42 contained in the base material 41. Increasing the content of the light-reflecting substance 42 in the first resin 40 can increase the light extraction efficiency from the light-emitting element 30. The concentration of the light-reflecting substance 42 in the first resin 40 is preferably 50% by mass or more and 70% by mass or less, for example, approximately 60% by mass.

[0025] Examples of the translucent resin for the base material 41 include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, and 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.

[0026] Suitable examples of the light-reflecting material include titanium oxide, aluminum oxide, zinc oxide, barium carbonate, barium sulfate, boron nitride, aluminum nitride, and glass filler. For example, the base material 41 is a dimethyl silicone resin, and the light-reflecting material is titanium oxide. The first resin 40 has a white appearance.

[0027] The second resin 50 is translucent 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 portions of the side surfaces 33, and the upper surface 43 of the first resin 40. The upper and lower portions of the side surfaces 33 refer to, for example, the upper surface region and the lower surface region of the side surfaces 33 in the height direction from the upper surface 31 to the lower surface 32. The second resin 50 includes at least a base material 51 made of a translucent resin, and the base material 51 may include a phosphor 52.

[0028] The base material 51 may be the same as the base material 41 of the first resin 40. The phosphor 52 may be an yttrium-aluminum-garnet phosphor (e.g., Y(Al,Ga)O 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)6Cl2:Eu), SAE-based phosphors (e.g., Sr4Al 14 O 25 :Eu), chlorosilicate phosphors (e.g., Ca8MgSiO 16 Cl2:Eu), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu), SLA-based phosphors (e.g., SrLiAlN:Eu), CASN-based phosphors (e.g., CaAlSiN:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN:Eu); fluoride-based phosphors such as KSF-based phosphors (e.g., KSiF:Mn), KSAF-based phosphors (e.g., K(Si,Al)F:Mn), or MGF-based phosphors (e.g., 3.5MgO·0.5MgF·GeO:Mn); phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)); or quantum dot phosphors (e.g., CdSe, InP, AgInS, or AgInSe).

[0029] 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, i.e., in the direction in which the wiring substrate 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 with the first resin 40, and the upper part is covered with the second resin 50. In other words, the light-emitting module 1 has a recess between adjacent light-emitting elements 30 that is 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 disposed in this recess.

[0030] The third resin 70 protects the wires that connect the package substrate 10 and the wiring board 20 . The third resin 70 has a rectangular frame shape in plan view that follows the outer edge of the wiring substrate 20. The third resin 70 is disposed from the upper surface of the package substrate 10 to the upper surface of the wiring substrate 20, and covers the upper surface pads 12 of the package substrate 10, the wires 60, and the external connection pads of the wiring substrate 20.

[0031] As shown in FIG. 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 substrate 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-blocking. 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. The base material may be the same material as the base material 41 of the first resin 40 described above. The light-reflective substance may be the same material as the light-reflective substance of the first resin 40 described above. Examples of the light-absorbing substance include carbon black and graphite.

[0032] In one example, the outer resin frame 71 and the inner resin frame 72 are translucent, and the protective resin 73 is light reflective (light blocking). The external appearance of the protective resin 73 is, for example, white, black, or gray. The first resin 40, the second resin 50, and the third resin 70 may each contain a colorant, a light diffusing material, a filler for adjusting viscosity, or the like, as needed.

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

[0034] (Process of Preparing the Wiring Board 20) First, as shown in FIG. 6A , a wiring substrate 20 is prepared. Next, a plurality of light-emitting elements 30 are placed in the central portion of the upper surface 21 of the wiring substrate 20, excluding the peripheral portion. The plurality of light-emitting elements 30 are bonded to the wiring substrate 20 via bonding material 39. A resist film 101 is placed in the peripheral portion of the upper surface 21 of the wiring substrate 20. The resist film 101 is placed on the wiring substrate 20 so as to surround the region 38 where the plurality of 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 manner, a wiring substrate 20 is prepared, on whose upper surface 21 the resist film 101 and a plurality of light-emitting elements 30 are placed.

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

[0036] Here, as described above, first resin 40 contains a high concentration of a light-reflective material. Therefore, uncured first resin 40 disposed on wiring substrate 20 is less likely to wet and spread over wiring substrate 20, and is more likely to maintain its shape as it is. For example, the viscosity of first resin 40 disposed on the upper surface of wiring substrate 20 is preferably 50 Pa·s or more and less than 200 Pa·s at room temperature (20±5°C). This prevents unintended spreading of first resin 40 into region 38 when disposed on wiring substrate 20, and makes it easier to control the migration of first resin to region 38 in the step of coating with the first resin, which will be described later.

[0037] (Step of covering with first resin 40) Next, the uncured first resin 40 is spread over the region 38, thereby disposing the first resin 40 between the wiring substrate 20 and the light-emitting elements 30. At this time, the top surfaces of the plurality of light-emitting elements 30 are also covered with the first resin. Then, the first resin 40 flows through the gaps between adjacent light-emitting elements 30, thereby covering the side surfaces of the light-emitting elements 30 with the first resin.

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

[0039] 6C and 10A, gas 300 is sprayed from nozzle 200 substantially perpendicularly toward the upper surface of wiring substrate 20, while nozzle 200 is moved in the Y direction, i.e., in the direction along which the short sides of region 38 extend. By spraying gas 300 toward upper surface 21 of wiring substrate 20 in this manner, uncured first resin 40 is stretched and spread along the Y direction. This movement of nozzle 200 may be repeated, for example, multiple times. As a result, first resin 40 can be spread over region 38, as shown in FIG. 8B.

[0040] At this time, the first resin 40 moves in the Y direction on the upper surface 31 of the light-emitting element 30, and also enters the gap between adjacent light-emitting elements 30, and further enters the gap between the wiring substrate 20 and the light-emitting element 30. By spraying the gas 300 from the nozzle 200 substantially perpendicularly toward the upper surface of the wiring substrate 20 while moving the nozzle 200 slowly in one direction, it is possible to suppress the generation of voids in the first resin 40 spread in the region 38.

[0041] In this embodiment, by spraying the gas 300 substantially perpendicularly toward the wiring substrate 20, the gas 300 sprayed substantially perpendicularly can be sprayed onto the first resin 40 along the upper surface of the resist film 101 and / or the wiring substrate 20. This changes the surface shape of the first resin 40 that has remained on the resist film 101 due to surface tension; specifically, it increases the contact angle between the first resin 40 and the upper surface of the resist film 101, thereby reducing wettability and allowing the first resin 40 to spread gently in the Y direction. Then, the first resin 40 that has reached the region 38 comes into contact with the light-emitting element 30, and by utilizing capillary action starting from the contact point, the first resin 40 can be wetted and spread into the gaps between and below the light-emitting element 30.

[0042] By spreading the first resin 40 in this manner, the occurrence of voids can be suppressed. Furthermore, since the thickness of the first resin 40 covering the upper surfaces of the light-emitting elements 30 is reduced, the first resin 40 can be more easily removed in the process of removing the first resin 40, which will be described later. In this manner, the first resin 40 is disposed between the wiring substrate 20 and the light-emitting elements 30 and between adjacent light-emitting elements 30, and the upper surfaces 31 of the plurality of light-emitting elements 30 are covered with the first resin 40. The first resin 40 is then cured, for example, by heat treatment. As an example, the thickness of the first resin 40 covering the upper surfaces of the light-emitting elements 30 is approximately 20 μm. While a portion of the upper surface of the light-emitting element 30 may be exposed from the first resin 40, it is preferable that the entire outer edge of the upper surface be covered with the first resin 40.

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

[0044] (Step of removing the first resin 40) Next, as shown in FIGS. 7A and 10B, solid carbon dioxide 500 is sprayed from a 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 located on the upper surface 31 of the light emitting element 30. This makes it possible to remove the first resin 40 from the upper surface 31 of the light emitting element 30. At this time, the upper portions of the first resin 40 that are located between the light emitting elements 30 are also removed, making it possible to expose the upper portions of the side surfaces 33 of the light emitting elements 30.

[0045] The particle diameter 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 / sec, for example, 50 mm / sec. The pressure at which the solid carbon dioxide 500 is sprayed is preferably 0.1 to 0.35 MPa, for example, 0.3 MPa. The number of repetitions of the movement of the nozzle 400 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 by, for example, wet etching. As shown in FIG. 7B, the intermediate body 90 consisting of the wiring substrate 20, the plurality of light-emitting elements 30, the resist film 101, and the first resin 40 is immersed in a resist remover solution 102. This allows the resist film 101 to be removed as shown in FIG. 7C.

[0047] (Process of Mounting the Wiring Board 20) 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 a metal paste. Examples of the adhesive member 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 plurality of light-emitting elements 30 and the first resin 40. As described above, the second resin 50 contains phosphor 52 in the base material 51. The second resin 50 is placed inside the frame-shaped third resin 70, i.e., in the region 38 where the plurality of light-emitting elements 30 are arranged. The second resin 50 may be placed by spraying or potting, or may be placed in a sheet form in advance.

[0049] (Step of curing the second resin 50) Next, the second resin 50 is cured by heat treatment. At this time, when the second resin 50 is heated to a first temperature, for example, 100°C, the second resin 50 is liquefied and enters the spaces above the first resin 40, which are the gaps between the light emitting elements 30. This allows the second resin 50 to come into contact with the upper parts of the side surfaces 33 of the light emitting elements 30. Next, when the second resin 50 is heated to a second main curing temperature higher than the first temperature, for example, 150°C, the second resin 50 is cured. In this manner, the light emitting module 1 according to this embodiment is manufactured.

[0050] The step of disposing and curing the second resin 50 may be performed between the step of peeling off the resist film 101 shown in FIG. 7B and the step of placing the wiring substrate 20 on the package substrate 10.

[0051] The manufacturing method of the light-emitting module 1 according to this embodiment may further include a step of electrically connecting the wiring board 20 and the package board by connecting the upper surface pads 12 of the package board 10 to the external connection pads of the wiring board 20 with wires 60, and a step of protecting the wires 60 by 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, the first resin 40 is disposed between the wiring substrate 20 and the light-emitting element 30. This allows the light emitted downward from the light-emitting element 30 to be reflected upward. This provides the light-emitting module 1 with high light extraction efficiency.

[0053] Furthermore, the concentration of the light-reflecting substance 42 in the first resin 40 is as high as 50 to 70 mass %, so the light reflectance of the first resin 40 is high. This allows the light-emitting module 1 to have 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 no adhesive layer or the like is interposed between the light-emitting element 30 and the second resin 50. This results in high light utilization efficiency.

[0055] Furthermore, in the light-emitting module 1, the upper portions of the side surfaces 33 of the light-emitting elements 30 are in contact with the second resin 50. The upper portions of the side surfaces 33 are exposed from the first resin 40, thereby improving the efficiency of extracting light from the light-emitting elements 30. Furthermore, the large contact area between the light-emitting elements 30 and the second resin 50 provides good adhesion.

[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 substrate 20 on which the first resin 40 is arranged, it is possible to reliably arrange the first resin 40 between the wiring substrate 20 and the light-emitting elements 30, and between the light-emitting elements 30, while suppressing the occurrence of voids. This makes it 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 the miniaturization of the light-emitting module 1. Furthermore, the light reflectivity of the first resin 40 can be improved.

[0057] 9, the width W of the opening shape of the nozzle 200 is set to be equal to or greater than the length L in the longitudinal direction of the region 38. This allows the first resin 40 to move simultaneously in the lateral direction of the region 38, thereby enabling the first resin 40 to spread efficiently and uniformly while suppressing the occurrence of voids.

[0058] Furthermore, by repeating the movement of the nozzle 200 multiple times, the thickness of the first resin 40 arranged on the upper surface 31 of the light-emitting element 30 can be made thinner. As a result, by spraying solid carbon dioxide, the first resin 40 can be removed from the upper surface 31 of the light-emitting element 30. Because solid carbon dioxide is soft, it is less likely to damage the light-emitting element 30, and it easily peels off the first resin 40 by sublimating near the interface between the light-emitting element 30 and the first resin 40. Furthermore, by spraying solid carbon dioxide, the upper part of the first resin 40 arranged between the light-emitting elements 30 is also removed, and the upper part of the side surface 33 of the light-emitting element 30 can be exposed.

[0059] The above-described embodiment is an example of realizing the present invention, and the present invention is not limited to this embodiment. For example, the present invention also includes any embodiment in which some components or steps are added, deleted, or modified. [Industrial Applicability]

[0060] The present invention can be used, for example, as a headlight for a vehicle and a light source for a display device. [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 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 stripper 200: Nozzle 300: Gas 400: Nozzle 500: Solid carbon dioxide L: Length W: Width

Claims

1. A wiring board; a plurality of light-emitting elements each having an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, the light-emitting elements being mounted on the wiring substrate such that the lower surface faces the upper surface of the wiring substrate; a first resin disposed between an upper surface of the wiring substrate and a lower surface of the light-emitting element and between the side surfaces of adjacent light-emitting elements, the first resin including a light-reflecting material; a second resin that covers an upper surface of the light-emitting element and an upper surface of the first resin and includes a phosphor; Equipped with an upper portion of the first resin has a removal surface that has been partially removed by spraying solid carbon dioxide thereon; An optical 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 surfaces of the light-emitting element are inclined so as to widen from the lower surface toward the upper surface.

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

4. A vehicle headlamp comprising the light emitting module according to any one of claims 1 to 3.

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