Method for manufacturing a light-emitting device

Abstract

The present invention provides a method for manufacturing a light-emitting device that can improve the reliability of the device. [Solution] The device substrate has a pair of mounting electrodes formed on the upper surface of a flat substrate, and the device substrate has a pair of mounting electrodes formed on the upper surface of the substrate. The device substrate has a pair of mounting electrodes formed on the upper surface of the substrate, and the device substrate has a pair of mounting electrodes that bond a light-emitting element that emits ultraviolet light to the pair of mounting electrodes to form a mounting substrate. The device substrate has a light-transmitting seal made of amorphous fluororesin that seals the light-emitting element on the substrate. The seal formation step includes a first step of forming a resin layer made of amorphous fluororesin on the upper surface of the substrate and on the surface of the light-emitting element, and a second step of holding the substrate in a holding mold so that its bottom surface is in contact with the holding mold, arranging amorphous fluororesin pellets on the periphery of the recess of the molding mold, and softening the resin layer and amorphous fluororesin pellets by heating, and closing the holding mold and the molding mold, thereby pressing the substrate against the amorphous fluororesin pellets and deforming the amorphous fluororesin pellets to cover the resin layer and form a seal.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a light-emitting device including a semiconductor light-emitting element.

Background Art

[0002] A method for manufacturing a light-emitting device including a light-emitting element that emits ultraviolet light has been disclosed. For example, Patent Document 1 discloses a method for manufacturing a light-emitting device including a step of mounting an ultraviolet light-emitting element on a flat submount, a step of forming a coating resin made of an amorphous fluororesin on the surface of the ultraviolet light-emitting element, and a step of forming a lens made of an amorphous fluororesin that covers the ultraviolet light-emitting element and the coating resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ultraviolet light-emitting device disclosed in Patent Document 1, for example, when an amorphous fluororesin having a non-reactive terminal functional group is used as the material of the coating resin or the lens that covers the ultraviolet light-emitting element, when the resin material that becomes the lens is brought into contact with the surface of the coating resin during manufacturing, the resin material moves greatly, resulting in poor molding or poor adhesion of the lens to the coating resin.

[0005] In such a case, for example, the output of the emitted light of the light-emitting device 100 may decrease due to poor molding of the lens, or poor sealing of the ultraviolet light-emitting element may occur due to poor adhesion of the lens to the coating resin. That is, the reliability of the light-emitting device may decrease.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide a method for manufacturing a light-emitting device that can improve the reliability of the device. [Means for solving the problem]

[0007] The present invention relates to a method for manufacturing a light-emitting device, comprising: a light-emitting element bonding step to form an element-bonded mounting substrate by bonding a light-emitting element that emits ultraviolet light to a pair of mounting electrodes of a device substrate having a flat substrate and a pair of mounting electrodes formed on the upper surface of the substrate; and a sealing body forming step to form a translucent sealing body made of amorphous fluororesin that seals the light-emitting element on the device substrate, wherein the sealing body forming step comprises: a first step of forming a resin layer made of amorphous fluororesin over the upper surface of the device substrate and the surface of the light-emitting element; and a second step, after the first step, of holding the element-bonded mounting substrate in a holding mold so that its bottom surface is in contact with the holding mold, arranging amorphous fluororesin pellets on the periphery of the recess of a molding die having a recess, softening the resin layer and amorphous fluororesin pellets by heating, and closing the holding mold and the molding die to press the element-bonded mounting substrate against the amorphous fluororesin pellets, deforming the amorphous fluororesin pellets to cover the resin layer and form a sealing body. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the light-emitting device according to Example 1. [Figure 2] This is a top view of the light-emitting device according to Example 1. [Figure 3] This is a cross-sectional view of the light-emitting device according to Example 1. [Figure 4] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 5] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 6] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 7] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 8] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 9] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 10] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 11] This is a cross-sectional view showing an example of the manufacturing process of the light-emitting device according to Example 1. [Figure 12] This is a cross-sectional view showing another example of the manufacturing process of the light-emitting device according to Example 1. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In the drawings, identical components are denoted by the same reference numerals, and descriptions of redundant components are omitted. [Examples]

[0010] The configuration of the light-emitting device 100 according to Embodiment 1 will be explained using Figures 1 to 3. Figure 1 is a perspective view of the light-emitting device 100. Figure 2 is a top view of the light-emitting device 100. Figure 3 is a cross-sectional view of the light-emitting device 100 shown in Figure 2 along line 3-3. In Figure 3, the vertical direction is the height direction of the light-emitting device 100, and the horizontal direction is the width direction of the light-emitting device 100.

[0011] [Overview of the light-emitting device 100] The light-emitting device 100 is composed of a device substrate 11, a light-emitting element 13 provided on the device substrate 11, and a sealing body 15 that covers and seals the light-emitting element 13 on the device substrate 11.

[0012] Note that in Figure 2, the sealing body 15 is omitted to avoid complexity in the illustration. Also, in Figure 2, the center line CL is shown as a line segment that passes through the center of the upper surface of the device substrate 11 and bisects the width of the device substrate 11 in the left-right direction in the figure.

[0013] [Device Substrate 11] First, the structure of the device substrate 11 will be described. The device substrate 11 is a double-sided wiring substrate composed of a flat base material 17 and wiring patterns provided on both main surfaces of the base material 17.

[0014] The base material 17 is a plate-shaped body having a rectangular upper surface shape. In the light-emitting device 100 of the present embodiment, the base material 17 is made of an insulating ceramic made of aluminum nitride (AlN) with excellent heat dissipation properties having a thermal conductivity of 150 to 220 (W / mK). Note that ceramics having ultraviolet resistance properties such as alumina (Al2O3) and silicon nitride (Si3N4) may be used for the base material 17.

[0015] Here, the wiring pattern provided on the base material 17 will be described. An element mounting electrode 18 and an annular member 21 are formed on the upper surface of the base material 17. Also, a mounting electrode 23 is formed on the lower surface of the base material 17.

[0016] The element mounting electrode 18 is a pair of electrodes provided on the upper surface of the base material 17 so as to be separated from each other with the center line CL interposed therebetween at substantially the center of the upper surface. The element mounting electrode 18 is composed of a first element mounting electrode 18A and a second element mounting electrode 18B each having a rectangular upper surface shape and the same size as each other. The first element mounting electrode 18A and the second element mounting electrode 18B are provided on the upper surface of the base material 17 such that their long sides face each other.

[0017] The region connecting the outer edges of the first element mounting electrode 18A and the second element mounting electrode 18B serves as an element mounting region for mounting and bonding the light-emitting element 13. The element mounting electrode 18 has a base material made of copper (Cu), and nickel (Ni) and gold (Au) as a protective layer are laminated in this order on its upper surface (surface).

[0018] The annular member 21 is an annular member having an annular upper surface shape. The annular member 21 is provided on the upper surface of the base material 17 such that its inner circle and outer circle are concentric circles in a plan view when the device substrate 11 is viewed from above. That is, the annular member 21 has a uniform bandwidth.

[0019] The annular member 21 surrounds the element mounting electrode 18 while maintaining a distance from it. In other words, the element mounting electrode 18 is positioned in the region of the upper surface of the base material 17 that is surrounded by the annular member 21.

[0020] The annular member 21 is formed by laminating Ni and Au as protective layers on the upper surface of Cu, with Cu being the base material. Alternatively, the annular member 21 may consist only of Cu, the base material, without the protective layers. Furthermore, the annular member 21 is not limited to a circular shape; it can also have an ellipse with a center of rotational symmetry, a petal shape with arcs radiating outwards, or a polygon with four or more sides.

[0021] The mounted electrodes 23 are formed on the lower surface of the substrate 17 at a distance from each other, and each electrode is a pair having a rectangular upper surface shape. The mounted electrodes 23 are electrically connected to the element mounting electrode 18 via conductive vias 24 made of conductive metal that penetrate the substrate 17 in the vertical direction in Figure 2.

[0022] Specifically, the mounting electrode 23 consists of a first mounting electrode 23A that is electrically connected to the first element mounting electrode 18A via a conductive via 24, and a second mounting electrode 23B that is electrically connected to the second element mounting electrode 18B via a conductive via 24.

[0023] In the light-emitting device 100 of this embodiment, the mounted electrode 23 has a base material of Cu, with Ni and Au laminated in that order on its underside (surface) as protective layers. The conductive via 24 is made of Cu only as the base material.

[0024] Furthermore, in addition to Cu, other metals such as aluminum (Al) and tungsten (W) can be selected as the base material for each of the element mounting electrodes 18, annular member 21, mounting electrode 23, and conductive via 24 described above. In addition, a combination of titanium (Ti) and Au, or a combination of chromium (Cr) and Au can be selected as the protective layer.

[0025] [Light-emitting element 13] Next, the configuration of the light-emitting element 13 will be described. The light-emitting element 13 is an element that is bonded to the element mounting electrode 18 of the device substrate 11. Here, as described above, the element mounting electrode 18 is located approximately in the center of the substrate 17 in a plan view. Therefore, the light-emitting element 13 is located approximately in the center of the device substrate 11 in a plan view.

[0026] As shown in Figure 3, the light-emitting element 13 is a light-emitting diode (LED) composed of an element substrate 26, a semiconductor structural layer 27 including a light-emitting layer, and p electrodes 28 and n electrodes 29 electrically connected to the semiconductor structural layer 27.

[0027] The element substrate 26 is a flat, translucent substrate with a rectangular top surface. In the light-emitting device 100 of this embodiment, the element substrate 26 is made of an AlN single crystal with a wurzite structure. A sapphire (Al2O3) single crystal can also be used for the element substrate 26.

[0028] The semiconductor structure layer 27 is a semiconductor crystal layer of aluminum gallium nitride (AlGaN) crystal system formed across the lower surface of the device substrate 26. The semiconductor structure layer 27 is constructed by stacking an n-type semiconductor layer, an emissive layer, and a p-type semiconductor layer (none of which are shown) in that order on the lower surface of the device substrate 26. The exposed surface of the semiconductor structure layer 27 is protected by a protective film of silicon dioxide (SiO2), Al2O3, etc.

[0029] When the light-emitting element 13 is energized, ultraviolet light with a peak wavelength of 265 nm is emitted from the light-emitting layer of the semiconductor structure layer 27. Note that each of the p-type semiconductor layer, light-emitting layer, and n-type semiconductor layer of the semiconductor structure layer 27 may include a superlattice layer, quantum well layer, barrier layer, etc.

[0030] The p-electrode 28 and n-electrode 29 are electrodes electrically connected to the p-type semiconductor layer and n-type semiconductor layer of the semiconductor structure layer 27, respectively. Each of the p-electrode 28 and n-electrode 29 is bonded to the first element mounting electrode 18A and the second element mounting electrode 18B, respectively, via a gold-tin (Au-Sn) bonding member 31. In other words, the light-emitting element 13 is flip-chip bonded to the device substrate 11.

[0031] In the light-emitting device 100, the first element mounting electrode 18A and the first mounting electrode 23A act as anode electrodes, and the second element mounting electrode 18B and the second mounting electrode 23B act as cathode electrodes.

[0032] When current is applied to the p electrode 28 and n electrode 29 of the light-emitting element 13, ultraviolet light emitted from the light-emitting layer of the semiconductor structural layer 27 is emitted to the outside of the light-emitting element 13 from the top and side surfaces of the element substrate 26. In other words, the top surface of the element substrate 26 is the light-emitting surface of the light-emitting element 13.

[0033] The upper surface of the element substrate 26 of the light-emitting element 13 is a -c plane (non-metallic surface) with nitrogen (N) atoms arranged on its surface. The lower surface of the element substrate 26 is a +c plane (metallic surface) with Al atoms arranged on its surface. Here, the Al atoms in the +c axis direction are polarized to δ+, and the N atoms in the -c axis direction are polarized to δ-.

[0034] In other words, the upper surface of the element substrate 26, which is the light-emitting surface of the light-emitting element 13, is a -c plane (non-metallic plane) where δ-polarized N atoms are arranged, and is a crystal plane (N atom plane) where dangling bonds (unbonded hands) of N atoms are exposed. Furthermore, the side surfaces of the element substrate 26 of the light-emitting element 13 are a plane and m plane or higher-order crystal planes having dangling bonds of Al atoms and N atoms.

[0035] [Sealing body 15] Next, the sealant 15 will be described. The sealant 15 is a transparent member that covers the upper surface of the device substrate 11. The sealant 15 seals and protects the light-emitting element 13, and at the same time transmits the light emitted from the light-emitting element 13, guiding the emitted light to the outside of the light-emitting device 100.

[0036] The encapsulant 15 is composed of a first encapsulant 15A and a second encapsulant 15B that covers the first encapsulant 15A. The first encapsulant 15A is a thin, transparent resin layer that covers the upper surface of the substrate 17, the wiring pattern provided on the substrate 17, and the surface of the light-emitting element 13.

[0037] Specifically, as shown in Figure 3, the first sealing member 15A tightly adheres (bonds) to the upper surface of the substrate 17, the surfaces of the element mounting electrodes 18, the surface of the light-emitting element 13 (top surface, side surface, and part of the bottom surface), and the surface of the annular member 21, following their respective shapes. The first sealing member 15A also fills the area between the upper surface of the device substrate 11 and the bottom surface of the light-emitting element 13.

[0038] The second sealing member 15B is a transparent member that covers the entire first sealing member 15A and has a bullet-shaped form that is convex upwards. In other words, the second sealing member 15B has a semi-ellipsoidal shape obtained by rotating a semi-ellipse with its major axis in the vertical direction in Figure 3.

[0039] The second sealing member 15B seals the light-emitting element 13 while adhering closely to (bonding) the first sealing member 15A on the device substrate 11. Here, the first sealing member 15A functions as an auxiliary adhesive layer for providing the second sealing member 15B on the device substrate 11.

[0040] Furthermore, the annular member 21 is completely covered by the first sealing member 15A, which provides an anchoring effect that physically holds the sealing body 15 to the device substrate 11 when external forces are applied from the left-right direction in the figure, for example, after the manufacturing of the light-emitting device 100. In other words, it can withstand external forces from the left-right direction in the figure via the first sealing member 15A that is in close contact (adhered) to the annular member 21. Such a configuration is particularly effective when using amorphous fluororesin with weak adhesion.

[0041] The second sealing member 15B functions as a convex lens with the major axis of the semi-ellipsoid described above as its optical axis. In a plan view of the light-emitting device 100 from above, the centers of the light-emitting element 13, the annular member 21, and the second sealing member 15B are arranged to overlap each other.

[0042] Therefore, the light emitted from the light-emitting element 13 has a directional characteristic in which it is focused along the optical axis of the second sealing member 15B and emitted to the outside. Furthermore, if the second sealing member 15B is hemispherical or semi-ellipsoidal in shape obtained by rotating a semi-ellipse with the vertical direction as the minor axis in Figure 3, the half-angle of the emitted light from the light-emitting device 100 can be widened.

[0043] The encapsulant 15 is made of a thermoplastic amorphous fluororesin (thermoplastic resin) that transmits the light emitted from the light-emitting element 13. The encapsulant 15 is, for example, the S-type of Cytop® manufactured by AGC Inc.

[0044] Specifically, the amorphous fluororesin used as the constituent material of the encapsulant 15 is formed by cyclopolymerization of the main chain perfluoro(4-vinyloxy-1-butene) (hereinafter also referred to as BVE), as shown in Chemical Formula 1 below, and the terminal functional group is a trifluoromethyl group (-CF3), which has high light resistance to ultraviolet light at the emission wavelength of 265 nm of the light-emitting element 13. Amorphous fluororesins modified at the ends or in the middle of the main chain with such perfluorocarbon-based functional groups have high light resistance to ultraviolet light at wavelengths of 220 nm to 300 nm. On the other hand, they have weak adhesion to other substances.

[0045] [ka]

[0046] Furthermore, this amorphous fluororesin has a refractive index of 1.34 and a transmittance of 90% or more for ultraviolet light. The light output of the light-emitting device 100 using this amorphous fluororesin as the sealant 15 is improved by more than 1.5 times compared to the light output of a light-emitting device sealed using, for example, a glass cap with a convex space in which the light-emitting element 13 is housed in that space.

[0047] In this embodiment, the light-emitting device 100 uses a wurtzite-structured single-crystal AlN substrate as the element substrate 26 of the light-emitting element 13, thereby improving adhesion (chemical bonding) with amorphous fluororesin having terminal functional groups of -CF3.

[0048] In detail, the light-emitting element 13 is configured such that its upper surface, i.e., the light-emitting surface (upper surface) of the element substrate 26, is a -c plane (non-metallic surface) where dangling bonds (unbonded bonds) of δ-polarized N atoms are arranged. This provides good adhesion (chemical bonding) or affinity between the upper surface of the light-emitting element 13 and the amorphous fluororesin obtained by cyclization polymerization of BVE with terminal functional groups of -CF3.

[0049] Furthermore, since dangling bonds of N atoms exist on the sides of the element substrate 26 (for example, the a-face and m-face), the adhesion (chemical bonding) or affinity between the sides of the element substrate 26 and the amorphous fluororesin obtained by cyclization polymerization of BVE with terminal functional groups of -CF3 is good.

[0050] Furthermore, in the light-emitting device 100 of this embodiment, since dangling bonds of N atoms are also present on the surface of the AlN polycrystalline ceramic material of the substrate 17 of the device substrate 11, the adhesion (chemical bonding) or affinity between the surface of the device substrate 11 and the amorphous fluororesin obtained by cyclization polymerization of BVE with terminal functional groups of -CF3 is good.

[0051] In this embodiment, the light-emitting device 100 does not necessarily have an annular member 21 formed on the upper surface of the substrate 17, and the first sealing member 15A may cover the upper surface of the substrate 17 and the surface of the light-emitting element 13.

[0052] [Manufacturing method for light-emitting device 100] The manufacturing method of the light-emitting device 100 will be described below with reference to Figures 4 to 11. Each of Figures 4 to 11 is a cross-sectional view showing an example of the manufacturing process of the light-emitting device 100.

[0053] The light-emitting device 100 is manufactured by a procedure that includes a device substrate preparation step of preparing a device substrate 11, an element bonding step of bonding a light-emitting element 13 to the device substrate 11, a first sealing member formation step of forming a first sealing member 15A on the device substrate 11, and a second sealing member formation step of forming a second sealing member 15B on the first sealing member 15A.

[0054] [Device board preparation process] First, as shown in Figure 4, a device substrate 11 is prepared, on which an element mounting electrode 18, an annular member 21, mounting electrode 23, and conductive via 24 are formed on a base material 17. Note that there are as many device substrates 11 as there are light-emitting devices 100 to be manufactured at one time, but only one of them is shown in Figure 4.

[0055] In the manufacturing of the device substrate 11, each of the element mounting electrode 18, annular member 21, mounting electrode 23, and conductive via 24 is formed by sequentially patterning various metals on the upper and lower surfaces of the substrate 17 using a film deposition method such as sputtering, electroless plating, or electrolytic plating.

[0056] In the light-emitting device 100 of this embodiment, the size and thickness of the base material 17 of the device substrate 11 are set to 3.6 mm square on each side and 0.5 mm thick. In addition, in the light-emitting device 100 of this embodiment, the inner diameter of the annular member 21 is set to 2.7 mm.

[0057] [Element bonding process] Next, as shown in Figure 5, the light-emitting element 13 is bonded to the upper surface of the device substrate 11. In the light-emitting device 100 of this embodiment, the dimensions and thickness of the light-emitting element 13 are 0.95 mm on the long side, 0.75 mm on the short side, and 0.11 mm in thickness.

[0058] Specifically, first, a solder paste containing 22wt% fine particles of Au-Sn, which will become a bonding member 31 after heating, is applied to the surface of the element mounting electrode 18 of the device substrate 11 by screen printing or potting. Next, the light-emitting element 13 is placed on the element mounting electrode 18 to which the solder paste has been applied, such that the p electrode 28 and n electrode 29 overlap.

[0059] Subsequently, the solder paste is heated to 300°C in a reflow oven to melt and solidify the 20wt% Au-Sn fine particles contained in the solder paste, causing the paste components other than Au-Sn to volatilize, and the light-emitting element 13 is bonded to the device substrate 11 via the bonding member 31. This process forms a mounting substrate with the light-emitting element bonded. For bonding the light-emitting element 13, bump bonding, thermocompression bonding, etc., can be selected.

[0060] [First sealing member formation process] Next, a first sealing member 15A is formed within the sealing body 15, covering the upper surface of the substrate 17, the element mounting electrode 18, the annular member 21, and the light-emitting element 13, respectively.

[0061] First, as shown in Figure 6, an amorphous fluororesin solution AC (hereinafter referred to as resin solution AC), which is an amorphous fluororesin that will become the first sealing member 15A, is applied to the entire upper surface of the device substrate 11 using, for example, a spray nozzle SN.

[0062] Subsequently, the apparatus substrate 11, onto which the resin solution AC has been dropped, is placed on a hot plate, and the underside of the apparatus substrate 11 is heated at 230°C for 60 minutes to evaporate the solvent in the resin solution AC and dry it (volatilization process).

[0063] After the solvent in the resin solution AC is evaporated, heating is continued at 230°C for 60 minutes (additional heat treatment step). This causes the dried fluororesin to soften and spread continuously, wetting and coating the surface of the light-emitting element 13 to the edge of the upper surface of the substrate 17. In this way, the adhesion of the first sealing member 15A to the device substrate 11 and the light-emitting element 13 is improved.

[0064] As a result of these operations, a first sealing member 15A, which is a thin film of amorphous fluororesin, is formed on the upper surface of the device substrate 11, extending across the surface of the light-emitting element 13 and the upper surface of the substrate 17, as shown in Figure 7.

[0065] [Second sealing member formation process] Next, a second sealing member 15B is formed to cover the first sealing member 15A of the sealing body 15. As described above, the second sealing member 15B is formed by compression molding using a pair of molds consisting of a first mold M1 and a second mold M2.

[0066] The first mold M1 has a flat plate shape and functions as a holding mold that holds the object to be formed as a resin body in compression molding and applies pressure to the second mold M2 while holding the object.

[0067] The second mold M2 has a downwardly convex, bullet-shaped recess CA, and functions as a mold that molds a resin body into a desired shape while receiving pressure from the first mold M1 during compression molding.

[0068] First, as shown in Figure 8, the device substrate 100A with the light-emitting element bonded to it, on which the first sealing member 15A is formed, is fixed to the first mold M1 in such a manner that the upper surface of the device substrate 11, i.e., the surface on which the light-emitting element 13 is formed, faces downward in the figure.

[0069] Furthermore, as shown in Figure 8, one amorphous fluororesin pellet RP (hereinafter referred to as resin pellet RP), which will serve as the second sealing member 15B, is placed on the peripheral edge of the recess CA of the second mold M2. In other words, the resin pellet RP is placed so as to cover the recess CA of the second mold M2. The resin pellet RP used in the manufacture of this light-emitting device 100 is a rectangular prism shape with a top and bottom surface that has sides of 1.8 mm and a height of 1.7 mm.

[0070] Furthermore, the shape of the resin pellet RP that will become the second sealing member 15B is not limited to a rectangular prism, but can also be a polygonal prism such as a hexagonal or octagonal prism, a cylinder, or a concentric polygonal prism or cylinder. In short, the resin pellet RP has a shape on its surface that contacts the upper surface of the light-emitting element 13, and it is sufficient that it can be held by the second mold M2 to the extent that it does not wobble when it contacts the upper surface of the light-emitting element 13.

[0071] For example, the resin pellet RP may be in the form of a pyramidal or conical shape with a bottom surface that contacts the top surface of the light-emitting element 13, or the resin pellet RP may be held in the second mold M2 in such a manner that its side surface and the edge of the recess CA are in contact. In short, the resin pellet RP only needs to have a shape such that its bottom surface (the top side in Figure 8) can enclose the top and side surfaces of the light-emitting element 13.

[0072] Next, the first mold M1 and the second mold M2 are heated to 180°C each under atmospheric conditions. As a result, heat is transferred from the first mold M1 and the second mold M2 to the first sealing member 15A and the resin pellet RP, respectively, causing the first sealing member 15A and the resin pellet RP to soften. The method of heating and softening the resin is not limited to changing the ambient temperature or directly heating the first sealing member 15A and the resin pellet RP with a radiant heater.

[0073] Next, as shown in Figure 9, while continuing to heat at 180°C, the first mold M1 is lowered as indicated by the arrow in the figure, and the light-emitting element bonded device substrate 100A on which the first sealing member 15A is formed is pressed against the softened resin pellet RP. In this embodiment, the load applied during pressing is 40 kgf.

[0074] This operation causes the softened resin pellet RP to deform within the recess CA due to pressure from the device substrate 100A with the light-emitting element bonded to it, embedding the resin pellet RP so as to enclose the light-emitting element 13. At this time, the softened resin pellet RP is molded to a shape that conforms to the recess CA of the second mold M2. In other words, the resin pellet RP is molded as a bullet-shaped resin body that covers the light-emitting element 13.

[0075] In this way, by placing the resin pellets RP in each of the recesses of the second mold M2, in the initial stages of the descent of the first mold M1, the bottom surface of the resin pellets RP encloses the top surface, sides, and substrate surface of the bonding base of the light-emitting element 13, while first adhering to them. Then, as the descent of the first mold M1 progresses, the resin pellets PR deform, and the adhesion progresses from the areas that have been enclosed to the periphery of the device substrate 11. In other words, a sealant 15 with excellent adhesion to the light-emitting element 13 and the device substrate 11 can be formed.

[0076] Furthermore, during the process in which the resin pellets RP soften and flow to cover the first sealing member 15A, they form a weldable adhesive surface with the first sealing member 15A. In other words, the softened resin pellets RP adhere well (bond) to the first sealing member 15A.

[0077] Furthermore, because the softened resin pellets RP adhere well to the first sealing member 15A, air bubbles are less likely to remain at the interface between the first sealing member 15A and the second sealing member 15B after the sealing body 15 is formed. As a result, the light-emitting element 13 and the entire sealing body 15 can be firmly adhered together while suppressing air bubbles within the sealing body 15, and especially in the region close to the interface between the sealing body 15 and the light-emitting element 13.

[0078] Furthermore, by providing the annular member 21 on the upper surface of the base material 17, the outflow of softened resin pellets RP can be suppressed (the internal pressure of the annular member 21 can be increased), thereby improving the adhesion (bonding) between the resin pellets RP and the inside of the annular member 21.

[0079] When the gap including the recess CA between the first mold M1 and the second mold M2 is filled with resin pellets RP, the descent of the first mold M1 stops, resulting in the configuration shown in Figure 10. Holding it in this state for 5 to 10 minutes improves the adhesion between the first sealing member 15A and the second sealing member 15B.

[0080] Finally, as shown in Figure 11, the temperatures of the first mold M1 and the second mold M2 are cooled to a temperature below the softening point of the amorphous fluororesin, for example, to about 50-80°C, and the temperature of the first mold M1 is raised as indicated by the arrow in the figure.

[0081] This operation causes the second sealing member 15B to be removed from the second mold M2 while remaining in close contact with the first sealing member 15A. As a result, a device substrate 100A with the light-emitting element bonded to it, on which the first sealing member 15A and the second sealing member 15B are formed, is obtained.

[0082] For example, if multiple resin pellets RP are placed in the recess CA of the second mold M2, air is more likely to be trapped between the first sealing member 15A and the second sealing member 15B, which may cause air bubbles to form at the interface between the first sealing member 15A and the second sealing member 15B after the light-emitting device 100 is manufactured. Therefore, in order to prevent the formation of such air bubbles, it is preferable that only one resin pellet RP is placed in the second mold M2.

[0083] [Singulation process] As the final step, the device substrate 11, which consists of the same number of light-emitting devices 100 to be manufactured at one time, is divided into individual pieces using a dicer so that each piece becomes a light-emitting device 100 having a single light-emitting element 13. This completes the manufacturing of the light-emitting devices 100. The annular member 21 prevents the cutting stress of the dicer from propagating to the inside of the annular member 21 during the piece-making process. Therefore, a highly reliable light-emitting device can be manufactured in which the sealant 15 does not peel off.

[0084] In this embodiment, the amorphous fluororesin, which is the material of the sealant 15 constituting the light-emitting device 100, has excellent light resistance (e.g., resistance to yellowing) and light transmittance to ultraviolet light in the wavelength range of 220 nm to 300 nm, but on the other hand, it has the characteristic of having low adhesion (chemical bonding) or affinity to other substances.

[0085] Therefore, even if one attempts to simply form the first sealing member 15A and then form the second sealing member 15B to cover it, because there is almost no tackiness between the surfaces of the first sealing member 15A and the resin pellets RP, when the resin pellets RP are brought into contact with the surface of the first sealing member 15A during the formation of the second sealing member 15B, the resin pellets RP may move significantly, which may result in the second sealing member 15B not being properly molded or poor adhesion of the second sealing member 15B to the first sealing member 15A.

[0086] When this occurs, the center of the second sealing member 15B and the light-emitting center of the light-emitting element 13 become misaligned in a top-down view of the light-emitting device 100, which may reduce the output of light emitted from the light-emitting device 100. Furthermore, in addition to the molding defect of the second sealing member 15B, the aforementioned poor adhesion may lead to a sealing defect of the light-emitting element 13. In other words, the reliability of the light-emitting device may decrease.

[0087] Therefore, in the manufacturing of the light-emitting device 100 of this embodiment, as described above, after the formation of the first sealing member 15A, the second sealing member 15B is formed by compression molding using a mold with preheating and press-fitting.

[0088] In this invention, by forming the second sealing member 15B using a method that involves preheating before molding, molding defects of the second sealing member 15B are prevented, and good adhesion between the second sealing member 15B and the first sealing member 15A is achieved. This improves the reliability of the light-emitting device.

[0089] Furthermore, according to the manufacturing method of the light-emitting device 100 of this embodiment, since multiple second sealing members 15B can be formed at once, the manufacturing time can be shortened compared to, for example, the case in which precursor resins that will become second sealing members 15B are placed one by one on the first sealing member 15A to form the second sealing members 15B.

[0090] In the manufacturing method of the light-emitting device 100 of this embodiment, for example, as shown in Figure 12, an air injection hole H may be provided in the second mold M2 on the periphery of the recess CA. This allows gas to be released from the recess CA through the air injection hole H. By adjusting the pressure of this gas release, the pressure inside the recess CA when the first sealing member 15A and the second sealing member 15B are in close contact can be controlled.

[0091] Furthermore, by introducing air through the air injection holes H after the formation of the second sealing member 15B, the second sealing member 15B can be easily removed from the second mold M2. Note that the configuration of the air injection holes H is not limited to this; for example, multiple air injection holes H may be provided in the second mold M2.

[0092] The light-emitting device 100 described in the above-mentioned embodiment can be used as a light source for various devices. For example, the light-emitting device 100 can be used as a light source for a resin curing device, a light source for a sterilization / disinfection / sterilization device, or a sensor light source for a distance measuring device. [Explanation of Symbols]

[0093] 100 Light-emitting devices 11. Device circuit board 13 Light-emitting element 15 Sealing member 15A 1st sealing member 15B Second sealing member 18 Element Mounting Electrodes 21 Annular member 23. Mounted electrodes

Claims

1. An element bonding step to form an element-bonded mounting substrate by bonding a light-emitting element that emits ultraviolet light to the pair of mounting electrodes of a device substrate having a flat substrate and a pair of mounting electrodes formed on the upper surface of the substrate, The process includes forming a sealant on the substrate of the apparatus, in which a translucent sealant made of amorphous fluororesin is formed to seal the light-emitting element, The above sealing body forming step is, A first step is to form a resin layer made of amorphous fluororesin over the upper surface of the apparatus substrate and the surface of the light-emitting element, A second step is to hold the element-bonded mounting substrate in a holding mold so that its bottom surface is in contact with the holding mold, place amorphous fluororesin pellets on the periphery of the recess in a molding die having a recess, soften the resin layer and the amorphous fluororesin pellets by heating, and then close the holding mold and the molding die to press the element-bonded mounting substrate against the amorphous fluororesin pellets, deforming the amorphous fluororesin pellets so as to cover the resin layer and form the seal, A method for manufacturing a light-emitting device, characterized by including the following:

2. The method for manufacturing a light-emitting device according to claim 1, characterized in that the first step includes a volatilization step of applying a solution obtained by dissolving amorphous fluororesin in a solvent over the upper surface of the device substrate and the surface of the light-emitting element, and volatilizing the solvent of the applied solution by heat treatment.

3. The method for manufacturing a light-emitting device according to claim 2, characterized in that the first step includes an additional heat treatment step of subsequently performing heat treatment after the volatilization step.

4. The method for manufacturing a light-emitting device according to any one of claims 1 to 3, characterized in that the recess of the mold has a bullet shape.

5. The terminal functional group of the amorphous fluororesin constituting the sealant is -CF ３ A method for manufacturing a light-emitting device according to any one of claims 1 to 3, characterized in that it is such.

6. The method for manufacturing a light-emitting device according to any one of claims 1 to 3, characterized in that the light-emitting element emits ultraviolet light with a wavelength of 200 nm to 300 nm.

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