Method for manufacturing light emitting device

Abstract

To provide a method for manufacturing a light emitting device that achieves both reduction in a varistor voltage and improvement in ESD resistance.SOLUTION: A method for manufacturing a light emitting device includes steps of: preparing a substrate having a pair of electrodes; preparing a protective member including resin having a dielectric constant of 3.0 or less and varistor particles; disposing and curing the protective member so as to connect the pair of electrodes; energizing the cured protective member by applying a voltage with a maximum current limited to 3 mA or more and 5 mA or less, or applying a voltage of 8kV or more and 10kV or less in accordance with JEDEC JESD22-A114; and electrically connecting a light emitting element to the pair of electrodes. In the step of preparing the protective member, 70% by weight or more of the varistor particles is included with respect to the entire protective member.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a light emitting device. [Background technology]

[0002] There is known a semiconductor light emitting device in which a semiconductor light emitting element is mounted on a circuit board. For example, Patent Document 1 discloses an LED package in which an LED chip is mounted on a base in which a varistor including a zinc oxide layer and a ceramic base are integrally formed by sintering the ceramic base.

[0003] Furthermore, for example, Patent Document 2 discloses a method for manufacturing a semiconductor light-emitting device in which a semiconductor light-emitting element is flip-chip mounted on a circuit board having electrodes and a protective member against static electricity arranged between the electrodes, in which a paste made by kneading varistor particles and a binder such as silicone resin as the protective member is applied between the electrodes of the circuit board by a printing method or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5698424 [Patent Document 2] JP 2012-109501 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the manufacturing methods of semiconductor light emitting devices described in Patent Documents 1 and 2, as the varistor voltage becomes lower, the device becomes more susceptible to breakdown when a relatively large ESD (Electro Static Discharge) is applied, making it difficult to achieve both a lower varistor voltage and improved ESD resistance.

[0006] An object of one embodiment of the present disclosure is to provide a method for manufacturing a light emitting device that achieves both a lower varistor voltage and improved ESD resistance. [Means for solving the problem]

[0007] A method for manufacturing a light emitting device according to one embodiment of the present disclosure includes the steps of: preparing a base having a pair of electrodes; preparing a protective member containing a resin having a relative dielectric constant of 3.0 or less and varistor particles; arranging and curing the protective member so as to connect the pair of electrodes; applying a voltage to the cured protective member, the maximum current of which is limited to between 3 mA and 5 mA, or applying a voltage of between 8 kV and 10 kV in accordance with JEDEC JESD22-A114, thereby passing a current through the cured protective member; and electrically connecting a light emitting element to the pair of electrodes, wherein in the step of preparing the protective member, the protective member contains 70% by weight or more of the varistor particles relative to the entirety of the protective member. Effect of the Invention

[0008] According to an embodiment of the present disclosure, a light emitting device can be manufactured that achieves both a lower varistor voltage and improved ESD resistance. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic perspective view of a light emitting device according to a first embodiment. [Diagram 2] 1 is a schematic perspective view of a light emitting device according to a first embodiment. [Diagram 3] 1 is a schematic front view of a light emitting device according to a first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. [Diagram 5] 1 is a schematic rear view of the light emitting device according to the first embodiment. [Figure 6] 4 is a flowchart showing the steps of a method for manufacturing the light emitting device according to the first embodiment. [Figure 7] 3 is a front view of a base body in the manufacturing method for the light emitting device according to the first embodiment. FIG. [Figure 8] FIG. 3 is a rear view (part 1) of the base body in the manufacturing method for the light emitting device according to the first embodiment. [Figure 9] FIG. 2 is a rear view (part 2) of the base body in the manufacturing method for the light emitting device according to the first embodiment. [Figure 10] FIG. 11 is a schematic perspective view of a light emitting device according to a second embodiment. [Figure 11] 11 is a schematic plan view of a light emitting device according to a second embodiment with a reflective member and a light-transmitting member removed therefrom. FIG. [Figure 12] FIG. 11 is a schematic plan view of a light emitting device according to a second embodiment. [Figure 13] FIG. 11 is a schematic side view of the light emitting device according to the second embodiment. [Figure 14] 1 shows initial voltage-current characteristics of the light-emitting devices of Examples 5 and 6. [Figure 15] 1 shows voltage-current characteristics after the fabrication of light emitting devices in Examples 5 and 6. [Figure 16] 1 shows voltage-current characteristics of the light emitting devices of Examples 5 and 6 after an additional HBM test. [Figure 17] FIG. 13 is a circuit diagram showing a circuit configuration of a light emitting device according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a description will be given of an embodiment of the invention with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "upper", "lower", and other terms including these terms) will be used as necessary. However, the use of these terms is for the purpose of facilitating understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Furthermore, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or members.

[0011] Furthermore, the embodiments shown below are illustrative of light-emitting devices and the like for embodying the technical ideas of the present invention, and do not limit the present invention to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended to be illustrative, and not to limit the scope of the present invention thereto. Furthermore, the contents described in one embodiment are also applicable to other embodiments and modified examples. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated in order to clarify the explanation. Furthermore, an end view showing only the cut surface may be used as a cross-sectional view.

[0012] First Embodiment [Light emitting device] 1 and 2 are schematic perspective views of the light emitting device according to the first embodiment, Fig. 3 is a schematic front view of the light emitting device according to the first embodiment, Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, and Fig. 5 is a schematic rear view of the light emitting device according to the first embodiment. As shown in Figs. 1 to 5, the light emitting device 10 includes a base 11, a light emitting element 12, a reflective member 15, a protective member 16, and a light-transmitting member 26. The light emitting device 10 according to the first embodiment is a side-emitting type light emitting device, but is not limited thereto, and may be a top-emitting type light emitting device.

[0013] The base 11 includes a base material 17 and a pair of electrodes (n-side electrode and p-side electrode) 18, 19. The pair of electrodes 18, 19 includes a pair of first wirings (n-side first wiring and p-side first wiring) 20, 21, a pair of second wirings (n-side second wiring and p-side second wiring) 22, 23, and third wirings (n-side third wiring and p-side third wiring) 24a, 24b arranged in the pair of through holes, respectively. The base material 17 has a front surface 171 extending in a first direction which is the longitudinal direction and a second direction which is the lateral direction, a back surface 172 located on the opposite side of the front surface 171, a bottom surface 173 adjacent to the front surface 171 and perpendicular to the front surface 171, and an upper surface 174 located on the opposite side of the bottom surface 173. In this specification, perpendicular means 90±3°.

[0014] The material constituting the base material 17 may be an insulating material such as a resin or fiber-reinforced resin, ceramics, or glass. Examples of the resin or fiber-reinforced resin include epoxy, glass epoxy, bismaleimide triazine (BT), polyimide, and the like. Examples of the ceramics include aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, and mixtures thereof. Of these materials, it is particularly preferable to use a material having physical properties close to the linear expansion coefficient of the light-emitting element 12.

[0015] The lower limit of the thickness of the base material 17 can be appropriately selected, but is preferably 0.05 mm or more, and more preferably 0.2 mm or more, from the viewpoint of the strength of the base material 17. Moreover, the upper limit of the thickness of the base material 17 is preferably 0.5 mm or less, and more preferably 0.4 mm or less, from the viewpoint of the thickness (depth) of the light emitting device 10.

[0016] The first wirings 20, 21 are disposed on the front surface 171 of the substrate 17 and are electrically connected to the light emitting element 12. The second wirings 22, 23 are disposed across the flat surface of the back surface 172 of the substrate 17 and the inner wall of the recess 25 provided on the back surface 172 of the substrate 17, and are electrically connected to the first wirings 20, 21 via the third wirings 24a, 24b. That is, the light emitting element 12 is electrically connected to the second wirings 22, 23. The first wirings 20, 21, the second wirings 22, 23, and the third wirings 24a, 24b can be formed of, for example, copper, iron, nickel, tungsten, chromium, aluminum, silver, gold, titanium, palladium, rhodium, or alloys thereof. These metals or alloys may be single-layered or multi-layered. In particular, copper or a copper alloy is preferable from the viewpoint of heat dissipation. In addition, a layer of, for example, silver, platinum, aluminum, rhodium, gold, or an alloy thereof may be disposed on the surface of the first wiring 20, 21 and / or the second wiring 22, 23 from the viewpoint of the wettability, light reflectivity, etc. of the conductive adhesive member.

[0017] The third wirings 24a, 24b are disposed in through holes penetrating the front surface 171 and the back surface 172 of the base material 17, and are in contact with the first wirings 20, 21 and the second wirings 22, 23. The third wirings 24a, 24b in this embodiment are disposed so as to cover the inner surface of the through hole of the base material 17, and a filling member may be disposed in the inner portion surrounded by the third wirings 24a, 24b. As the filling member, a conductive member or an insulating member may be used.

[0018] The base material 17 further has at least one recess 25. The light emitting device 10 can be fixed to a mounting board by a bonding member such as solder formed in the recess 25. In the example shown in Fig. 4, there are two recesses 25. The recesses 25 open to a back surface 172 and a bottom surface 173 of the base material 17.

[0019] 5, the opening shape of the recess 25 on the back surface 172 is preferably semicircular. When the opening shape of the recess 25 is a semicircular shape without corners, stress is less likely to concentrate on the recess 25, and the risk of cracking the base material 17 can be reduced. In this specification, the semicircular shape includes not only a perfect semicircle, but also shapes close to it (for example, an elliptical semicircular shape).

[0020] 5, when there are multiple recesses 25 on the rear surface 172, they are preferably located symmetrically with respect to the center line of the base material 17 that is parallel to the second direction (Y direction). In this way, self-alignment works effectively when the light emitting device 10 is mounted on the mounting board via a bonding member, and the light emitting device 10 can be mounted with high precision within the mounting range.

[0021] In the bottom surface 173, the depth of the recess 25 in the Z direction may be approximately constant, or the depth of the recess 25 may differ between the center and the end. As shown in FIG. 2, it is preferable that the depth of the center of the recess 25 in the bottom surface 173 is the maximum depth of the recess in the Z direction. In this way, the thickness of the base material 17 in the Z direction can be increased at the end of the recess 25 in the X direction in the bottom surface 173, so that the strength of the base material 17 can be improved. In this specification, the center means that a variation of about 5 μm is allowed. The recess 25 can be formed by a known method such as a drill or a laser.

[0022] In addition to the structure of this embodiment, the base 11 can also have a structure in which, for example, a pair of lead terminals formed from a lead frame are used as a pair of electrodes, and the pair of lead terminals are supported by a base material.

[0023] The protective member 16 has a function of protecting the light emitting element 12 from damage due to ESD. The protective member 16 is arranged to connect a pair of electrodes 18, 19, and in this embodiment, is arranged to connect a pair of second wirings 22, 23 of the pair of electrodes 18, 19. The protective member 16 may be arranged to connect a pair of first wirings 20, 21 instead of the pair of second wirings 22, 23. The protective member 16 contains a resin having a relative dielectric constant of 3.0 or less and varistor particles.

[0024] Examples of the resin having a relative dielectric constant of 3.0 or less include dimethyl silicone and phenylmethyl silicone. The content of the resin in the protective member 16 is preferably 7.5% by weight to 29.5% by weight, more preferably 7.5% by weight to 24.5% by weight, and even more preferably 7.5% by weight to 19.5% by weight.

[0025] The varistor particles are ceramics mainly composed of zinc oxide, and preferably further contain at least one selected from bismuth, cobalt, antimony, and manganese. Here, the main component means the component with the largest content among the multiple components constituting the varistor particles. The content of zinc oxide is preferably 70% by weight or more, more preferably 80% by weight or more, and even more preferably 90% by weight or more, based on the varistor particles.

[0026] The content of the varistor particles is 70% by weight or more with respect to the protective member 16. The content of the varistor particles is preferably 70% by weight or more and 90% by weight or less, more preferably 75% by weight or more and 90% by weight or less, and even more preferably 80% by weight or more and 90% by weight or less.

[0027] The particle size of the varistor particles is preferably from 1 μm to 150 μm, more preferably from 3 μm to 100 μm, and even more preferably from 5 μm to 50 μm.

[0028] The protective member 16 preferably contains an insulating filler in an amount of 0.5% by weight to 2.5% by weight based on the protective member 16. Examples of materials constituting the insulating filler include zinc oxide, silicon oxide, and thermoplastic resins such as polystyrene and polymethyl methacrylate, and one of these may be used alone or two or more of these may be used in combination. Among these, the insulating filler preferably contains at least one selected from zinc oxide and silicon oxide. The insulating filler preferably contains at least one selected from porous particles and hollow particles. The particle size of the porous particles and hollow particles is preferably 0.1 μm to 100 μm, more preferably 0.3 μm to 50 μm, and even more preferably 0.5 μm to 10 μm.

[0029] The protective member 16 preferably contains a platinum-based curing catalyst of 4 ppm by weight or more relative to the resin having a relative dielectric constant of 3.0 or less. The content of the platinum-based curing catalyst is preferably 4 ppm by weight or more and 500 ppm by weight or less, more preferably 4 ppm by weight or more and 50 ppm by weight or less, and even more preferably 4 ppm by weight or more and 20 ppm by weight or less, relative to the resin having a relative dielectric constant of 3.0 or less.

[0030] Examples of platinum-based curing catalysts include platinum metal, platinum black, platinum compounds such as chloroplatinic acid or alcohol-modified chloroplatinic acid, and platinum complexes such as a complex of platinum and an olefin, a complex of chloroplatinic acid and an olefin, a platinum diketone complex, a platinum vinylsiloxane complex, or a platinum phosphine complex.

[0031] As shown in FIG. 4, the light emitting element 12 has a mounting surface facing the base 11 and a light extraction surface 122 located on the opposite side of the mounting surface. The light emitting element 12 includes at least a semiconductor laminate 12a, and the semiconductor laminate 12a has positive and negative electrodes 13 and 14 (negative electrode 13 and positive electrode 14) arranged thereon. The positive and negative electrodes 13 and 14 are formed on the same side of the light emitting element 12, and it is preferable that the light emitting element 12 is flip-chip mounted on the base 11. This eliminates the need for wires to supply electricity to the positive and negative electrodes 13 and 14 of the light emitting element 12, allowing the light emitting device 10 to be made smaller. When the light emitting element 12 is flip-chip mounted, the surface opposite to the electrode formation surface on which the positive and negative electrodes 13 and 14 of the light emitting element 12 are located is set as the light extraction surface 122.

[0032] In this embodiment, the light emitting element 12 may have an element substrate, or the element substrate may be removed. When the light emitting element 12 is flip-chip mounted on the base 11, the positive and negative electrodes 13, 14 of the light emitting element are connected to the first wiring 20, 21 via a conductive adhesive member. The positive and negative electrodes 13, 14 may be made of, for example, gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel, or an alloy thereof. As the conductive adhesive member, any one of bumps such as gold, silver, copper, or the like, solder such as gold-tin, and brazing material such as low melting point metal can be used.

[0033] The light emitting element 12 is a semiconductor element that emits light by itself when a voltage is applied, and a known semiconductor element composed of a nitride semiconductor or the like can be used. An example of the light emitting element 12 is an LED chip. The shape of the light emitting element 12 viewed from above is preferably rectangular, particularly a square shape or a rectangular shape that is long in one direction, but may be other shapes, and for example, a hexagonal shape can increase the light emitting efficiency. The side surface 121 of the light emitting element 12 may be perpendicular to the light extraction surface 122, or may be inclined inward or outward.

[0034] The emission peak wavelength of the light emitting element 12 can be selected from the ultraviolet region to the infrared region depending on the semiconductor material and its mixed crystal ratio. As the semiconductor material, it is preferable to use a nitride semiconductor, which is a material capable of emitting light of a short wavelength that can efficiently excite the wavelength conversion particles. Nitride semiconductors are mainly represented by the general formula In x Al y Ga 1-x-y N (0≦x, 0≦y, x+y≦1). From the viewpoints of luminous efficiency, excitation of wavelength converting particles and color mixing with the emission, the emission peak wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less, more preferably 420 nm or more and 490 nm or less, and even more preferably 450 nm or more and 475 nm or less. In addition, InAlGaAs-based semiconductors, InAlGaP-based semiconductors, zinc sulfide, zinc selenide, silicon carbide, etc. can also be used.

[0035] The element substrate of the light emitting element 12 is a crystal growth substrate on which the semiconductor crystals constituting the semiconductor laminate 12a can be grown, but may also be a bonding substrate to be bonded to a semiconductor element structure separated from the crystal growth substrate. The element substrate has light transmissivity, which makes it easy to adopt flip-chip mounting and to improve the light extraction efficiency. Examples of the base material of the element substrate include sapphire, gallium nitride, aluminum nitride, silicon, silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, zinc sulfide, zinc oxide, zinc selenide, and diamond. Among them, sapphire is preferable. The thickness of the element substrate can be appropriately selected, and is, for example, 0.02 mm or more and 1 mm or less, and is preferably 0.05 mm or more and 0.3 mm or less in terms of the strength of the element substrate and / or the thickness of the light emitting device.

[0036] The reflective member 15 covers, for example, the side surface 121 of the light-emitting element 12 and the front surface 171 of the base material 17. By covering the side surface 121 of the light-emitting element 12 with the reflective member 15, the reflective member 15 can reflect light traveling in the X direction and / or Y direction from the light-emitting element 12, thereby increasing the amount of light traveling in the Z direction.

[0037] From the viewpoint of light extraction efficiency in the Z direction, the light reflectance of the reflective member 15 at the emission peak wavelength of the light emitting element 12 is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. The reflective member 15 is preferably white. Therefore, the reflective member 15 preferably contains a white pigment in the base material. The reflective member 15 goes through a liquid state before curing. The reflective member 15 can be formed by transfer molding, injection molding, compression molding, potting, or the like.

[0038] The base material of the reflective member 15 may be a resin, such as a silicone resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, or a modified resin thereof. Among these, silicone resin and modified silicone resin are preferable because they have excellent heat resistance and light resistance. Specific examples of silicone resins include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin.

[0039] The white pigment may be, for example, one of titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, or silicon oxide, which may be used alone or in combination of two or more thereof.

[0040] The shape of the white pigment can be appropriately selected, and may be amorphous or crushed, but is preferably spherical from the viewpoint of fluidity. The particle size of the white pigment can be, for example, about 0.1 μm to 0.5 μm, but the smaller the particle size, the better in order to enhance the light reflection and covering effect. The content of the white pigment can be appropriately selected, but from the viewpoint of light reflectivity and viscosity in a liquid state, it is preferably 10% by weight to 80% by weight, more preferably 20% by weight to 70% by weight, and even more preferably 30% by weight to 60% by weight with respect to the reflective member 15.

[0041] The light emitting device 10 may include a light-transmitting member 26 that covers the light emitting element 12. By covering the light emitting element 12 with the light-transmitting member 26, the light emitting element 12 can be protected from external stress.

[0042] When the light-emitting device 10 includes the light-transmitting member 26, the side surface of the light-transmitting member 26 is preferably covered with the reflecting member 15. In this way, a light-emitting device with high contrast between the light-emitting region and the non-light-emitting region and good visibility can be obtained.

[0043] The light-transmitting member 26 may contain wavelength-converting particles. The wavelength-converting particles are materials that absorb at least a part of the primary light emitted by the light-emitting element 12 and emit secondary light with a wavelength different from the primary light. By containing the wavelength-converting particles in the light-transmitting member 26, it is possible to output mixed-color light in which the primary light emitted by the light-emitting element 12 and the secondary light emitted by the wavelength-converting particles are mixed. For example, if a blue LED is used as the light-emitting element 12 and a phosphor such as YAG is used as the wavelength-converting particles, it is possible to configure a light-emitting device that outputs white light obtained by mixing the blue light of the blue LED and the yellow light emitted by the phosphor when excited by the blue light.

[0044] The wavelength conversion particles may be uniformly dispersed in the light-transmitting member 26, or the wavelength conversion particles may be unevenly distributed closer to the light-emitting element 12 than to the front surface 261 of the light-transmitting member 26. By unevenly distributing the wavelength conversion particles closer to the light-emitting element 12 than to the front surface 261 of the light-transmitting member 26, the base material of the light-transmitting member 26 also functions as a protective layer even if wavelength conversion particles that are sensitive to moisture are used, thereby reducing the risk of the wavelength conversion particles deteriorating.

[0045] 4, light-transmitting member 26 may include layer 26a containing wavelength converting particles and layer 26b containing substantially no wavelength converting particles. In the Z direction, layer 26b containing substantially no wavelength converting particles is located above layer 26a containing wavelength converting particles. In this way, layer 26b containing substantially no wavelength converting particles also functions as a protective layer, thereby reducing deterioration of the wavelength converting particles.

[0046] Examples of wavelength-converting particles that are vulnerable to moisture include manganese-activated fluoride phosphors. Manganese-activated fluoride phosphors are preferable in terms of color reproducibility because they can emit light with a relatively narrow spectral line width. "Substantially free of wavelength-converting particles" means that wavelength-converting particles that are inevitably mixed in are not excluded, and the content of wavelength-converting particles is preferably 0.05% by weight or less.

[0047] The base material of the light-transmitting member 26 may be any material that is translucent to the light emitted from the light-emitting element 12. The term "translucent" means that the light transmittance at the emission peak wavelength of the light-emitting element is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. The base material of the light-transmitting member 26 may be a silicone resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, or a modified resin thereof, or glass. Among them, the silicone resin and the modified silicone resin are preferable because they have excellent heat resistance and light resistance. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. The light-transmitting member 26 may be formed of a single layer of one of these base materials, or a laminate of two or more of these base materials. In this specification, the term "modified resin" includes a hybrid resin.

[0048] The base material of the light-transmitting member 26 may contain various kinds of diffusing particles in the resin or glass. Examples of the diffusing particles include silicon oxide, aluminum oxide, zirconium oxide, and zinc oxide. The diffusing particles may be one of these alone or two or more of these in combination. Silicon oxide, which has a small thermal expansion coefficient, is particularly preferable. In addition, by using nanoparticles as the diffusing particles, it is possible to increase the scattering of light emitted by the light-emitting element and reduce the amount of wavelength conversion particles used. Note that "nanoparticles" are particles with a particle diameter of 1 nm or more and 100 nm or less. In addition, the "particle diameter" in this specification is defined as, for example, D50.

[0049] The wavelength converting particles may be used singly or in combination of two or more of the specific examples shown below.

[0050] As wavelength conversion particles that emit green light, yttrium-aluminum-garnet phosphors (e.g., Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g. Lu3(Al,Ga)5O 12:(Ce), terbium-aluminum-garnet-based phosphor (e.g., Tb3(Al,Ga)5O 12 :Ce)-based phosphor, silicate-based phosphor (e.g., (Ba,Sr)2SiO4:Eu), chlorosilicate-based phosphor (e.g., Ca8Mg(SiO4)4Cl2:Eu), β-sialon-based phosphor (e.g., Si 6-z Al z O z N 8-z :Eu(0 < z < 4.2)), SGS-based phosphor (e.g., SrGa2S4:Eu), alkaline earth aluminate-based phosphor (e.g., (Ba,Sr,Ca)Mg x Al 10 O 16+x :Eu,Mn (where 0 ≦ x ≦ 1)) and the like. As the wavelength conversion particles that emit yellow light, α-sialon-based phosphors (e.g., M z (Si,Al) 12 (O,N) 16 (where 0 < z ≦ 2 and M is a lanthanide element excluding Li, Mg, Ca, Y, and La and Ce) and the like. As the wavelength conversion particles that emit red light, nitrogen-containing calcium aluminosilicate (CASN or SCASN)-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu) and the like. In addition, manganese-activated fluoride-based phosphors (general formula (I) A2[M 1-a Mn a F6] (where in the above general formula (I), A is at least one selected from the group consisting of K, Li, Na, Rb, Cs, and NH4, M is at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and a satisfies 0 < a < 0.2)) and the like.

[0051] The light-transmitting member 26 may cover the light-emitting element 12 via the light-guiding member 27. The light-guiding member 27 is a member that bonds the light-emitting element 12 and the light-transmitting member 26 and guides the light from the light-emitting element 12 to the light-transmitting member 26. The light-guiding member 27 may be located between the light-extraction surface 122 of the light-emitting element 12 and the light-transmitting member 26 to fix the light-emitting element 12 and the light-transmitting member 26, or may cover the side surface 121 of the light-emitting element 12 to fix the light-emitting element 12 and the light-transmitting member 26. The light-guiding member 27 has a higher transmittance of light from the light-emitting element 12 than the reflecting member 15. Therefore, by the light-guiding member 27 covering the side surface 121 of the light-emitting element 12, the light emitted from the side surface 121 of the light-emitting element 12 is easily extracted to the outside of the light-emitting device 10 through the light-guiding member 27, so that the light extraction efficiency can be improved.

[0052] The base material of the light-guiding member 27 may be a silicone resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, or a modified resin thereof. Among them, silicone resin and modified silicone resin are preferable because of their excellent heat resistance and light resistance. Specific examples of silicone resins include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. The base material of the light-guiding member 27 may contain wavelength conversion particles similar to those of the above-mentioned light-transmitting member 26.

[0053] [Manufacturing method of light emitting device] Fig. 6 is a flow chart showing the steps of the method for manufacturing the light emitting device according to the first embodiment, Fig. 7 is a front view of a base in the method for manufacturing the light emitting device according to the first embodiment, Fig. 8 is a rear view (part 1) of the base in the method for manufacturing the light emitting device according to the first embodiment, and Fig. 9 is a rear view (part 2) of the base in the method for manufacturing the light emitting device according to the first embodiment. An example of the method for manufacturing the light emitting device according to the first embodiment will be described with reference to Figs. 6 to 9.

[0054] 6, the manufacturing method of the light emitting device 10 of this embodiment includes a step of preparing a base 11 having a pair of electrodes 18, 19 (step S1), and a step of preparing a protective member 16 containing a resin having a relative dielectric constant of 3.0 or less and varistor particles (step S2). It also includes a step of disposing the protective member 16 so as to connect the pair of electrodes 18, 19 and curing it (step S3), a step of applying a voltage with a maximum current limited to 3 mA or more and 5 mA or less to the cured protective member 16, or a step of applying a voltage of 8 kV or more and 10 kV or less in accordance with JEDEC JESD22-A114 to energize the cured protective member 16 (step S4), and a step of electrically connecting the light emitting element 12 to the pair of electrodes 18, 19 (step S5). In the step of preparing the protective member 16, the protective member 16 contains 70% by weight or more of varistor particles relative to the entirety of the protective member 16.

[0055] According to the above-mentioned manufacturing method of the light emitting device 10, the protective member 16 contains a resin having a relative dielectric constant of 3.0 or less and varistor particles, so that the light emitting device 10 can be manufactured with improved resistance (ESD resistance) against overvoltage such as surge (abnormal voltage) and ESD. It is presumed that if the relative dielectric constant of the resin exceeds 3.0, the resin is more likely to deteriorate when an overvoltage is applied due to the relatively large amount of charge accumulated in the resin. Furthermore, the protective member 16 contains 70% by weight or more of varistor particles relative to the entirety, so that the light emitting device 10 can be manufactured with a lower varistor voltage and improved ESD resistance. Furthermore, by passing a current through the hardened protective member 16, the light emitting device 10 can be manufactured in which the varistor voltage is lowered compared to before the current is passed and the varistor voltage and ESD resistance are stably maintained. As described above, according to the manufacturing method of the light emitting device 10 of this embodiment, a light emitting device can be manufactured that achieves both a lower varistor voltage and improved ESD resistance.

[0056] (Step of Preparing the Base 11) The manufacturing method of the light emitting device 10 of this embodiment includes a step of preparing a base 11 having a pair of electrodes 18, 19, as shown in Figs. 7 and 8. Specifically, the base 11 includes a base material 17 and a pair of electrodes (n-side electrode and p-side electrode) 18, 19 (see Fig. 8). The pair of electrodes 18, 19 includes a pair of first wirings (n-side first wiring and p-side first wiring) 20, 21 (see Fig. 7) arranged on the front surface 171 of the base material 17, a pair of second wirings (n-side second wiring and p-side second wiring) 22, 23 (see Fig. 4), and third wirings (n-side third wiring and p-side third wiring) 24a, 24b arranged in a pair of through holes, respectively. The second wirings 22, 23 are electrically connected to the first wirings 20, 21 via the third wirings 24a, 24b. In the example shown in Figs. 7 and 8, the base 11 is an aggregate circuit board. Details of the base 11 are the same as those of the base 11 in the above-described light-emitting device 10, and therefore a description thereof will be omitted here. Hereinafter, descriptions of members common to the light-emitting device 10 will be omitted, as they are the same as those of the light-emitting device 10. Note that the base 11 may be prepared by manufacturing it, or may be prepared by receiving it from another person.

[0057] In the step of preparing the base 11, the distance L between the pair of second wirings 22, 23, on which the protective member 16 described later is disposed, of the pair of electrodes 18, 19, is preferably 30 μm or more and 70 μm or less. Here, the distance between the pair of electrodes 18, 19 (second wirings 22, 23) means the shortest distance. As a result, the manufacturing method for the light emitting device 10 of this embodiment can manufacture a light emitting device 10 with a lower varistor voltage.

[0058] (Step of Preparing Protective Member 16) The manufacturing method of the light emitting device 10 of this embodiment includes a step of preparing a protective member 16 containing a resin having a relative dielectric constant of 3.0 or less and varistor particles. Specifically, in the step of preparing the protective member 16, a resin having a relative dielectric constant of 3.0 or less is mixed with varistor particles. The mixing can be performed using a mixer such as a dissolver, a roll mill, a rotary mixer, or a twin-shaft mixer. The protective member 16 may be prepared by manufacturing it, or may be prepared by receiving it from another person.

[0059] In the step of preparing the protective member 16, the protective member 16 may be prepared including, in addition to a resin having a relative dielectric constant of 3.0 or less and varistor particles, an insulating filler of 0.5% by weight or more and 2.5% by weight or less relative to the protective member 16. Specifically, in the step of preparing the protective member 16, a resin having a relative dielectric constant of 3.0 or less, varistor particles, and an insulating filler of 0.5% by weight or more and 2.5% by weight or less relative to the protective member 16 are mixed. The mixing can be performed, for example, using the mixer described above.

[0060] The insulating filler preferably contains at least one selected from zinc oxide and silicon oxide, and thus the method for producing the light emitting device 10 of the present embodiment can produce the light emitting device 10 in which the resin contained in the protective member 16 is further prevented from being deteriorated by ESD.

[0061] The insulating filler preferably contains at least one selected from porous particles and hollow particles. As a result, the manufacturing method for the light emitting device 10 of the present embodiment can manufacture the light emitting device 10 in which the resin contained in the protective member 16 is further reduced from being deteriorated by ESD. Specifically, the insulating filler may contain at least one of porous silica particles and hollow silica particles.

[0062] In the step of preparing the protective member 16, the varistor particles are ceramics containing zinc oxide as a main component, and preferably further contain at least one element selected from bismuth, cobalt, antimony, and manganese. As a result, the method for manufacturing the light emitting device 10 of this embodiment can manufacture a light emitting device 10 with an improved nonlinearity coefficient (α).

[0063] In the step of preparing the protective member 16, it is preferable to prepare the protective member 16 containing a resin having a relative dielectric constant of 3.0 or less, varistor particles, and a platinum-based curing catalyst of 4 ppm or more by weight relative to the resin. The platinum-based curing catalyst is a catalyst for curing the resin, but when the varistor particles contain zinc, manganese, or antimony, the zinc, manganese, or antimony inhibits the action of the platinum-based curing catalyst. By preparing the protective member 16 containing a platinum-based curing catalyst of 4 ppm or more by weight relative to the resin in the step of preparing the protective member 16, the manufacturing method of the light-emitting device 10 of this embodiment can manufacture a light-emitting device 10 having a protective member 16 with high mechanical strength, which can reduce the varistor voltage and more stably maintain ESD resistance.

[0064] In the step of preparing the protective member 16, it is preferable to prepare a protective member 16 containing a resin containing dimethyl silicone. As a result, the method for manufacturing the light emitting device 10 of this embodiment can manufacture a light emitting device 10 with a lower varistor voltage and improved ESD resistance.

[0065] Details of the protective member 16 and the resin, varistor particles, and insulating filler contained in the protective member 16 are similar to those of the protective member 16 and the resin, varistor particles, and insulating filler contained in the protective member 16 in the light-emitting device 10 described above, so they will not be described here.

[0066] (Step of placing and hardening protective member 16) The manufacturing method of the light emitting device 10 of the present embodiment includes a step of arranging and curing the protective member 16 so as to connect the pair of second wirings 22, 23 of the pair of electrodes 18, 19. Specifically, in the step of arranging and curing the protective member 16, the protective member 16 prepared in the step of preparing the protective member 16 is applied to the back surface 172 of the base material 17 between the pair of second wirings 22, 23 and the pair of second wirings 22, 23, and the applied protective member 16 is heated to be cured. The method of applying the protective member 16 may be, for example, a transfer molding method, a compression molding method, an injection molding method, a screen printing method, an inkjet method, or the like. In the step of arranging and curing the protective member 16, for example, the protective member 16 can be cured by heating it at a temperature of 100°C or more and 200°C or less for 10 minutes to 6 hours.

[0067] (Step of applying current to the hardened protective member 16) The manufacturing method of the light emitting device 10 of this embodiment includes a step of applying a voltage with a maximum current limited to 3 mA or more and 5 mA or applying a voltage of 8 kV or more and 10 kV or less in accordance with JEDEC JESD22-A114 (HBM (Human Body Method) test) to the cured protective member 16 to pass a current through it. When applying a voltage with a maximum current limited to 3 mA or more and 5 mA or less in the step of passing a current through the cured protective member 16, for example, a curve tracer can be used.

[0068] (Step of electrically connecting the light emitting element 12) The manufacturing method of the light emitting device 10 of this embodiment includes a step of electrically connecting the light emitting element 12 to a pair of second wirings 22, 23 of the pair of electrodes 18, 19. That is, the step of electrically connecting the light emitting element 12 is a step of mounting the light emitting element 12 on the base 11. In the step of electrically connecting the light emitting element 12, the positive and negative electrodes 13, 14 of the light emitting element 12 are connected to the pair of first wirings 20, 21 of the base 11 with a conductive adhesive member. In addition, the pair of first wirings 20, 21 are electrically connected to the pair of second wirings 22, 23 arranged on the back surface 172 of the base material 17 via the third wirings 24a, 24b.

[0069] In the step of electrically connecting the light emitting element 12, the rated current of the light emitting element 12 may be 10 mA or more and 1500 mA or less. As a result, the manufacturing method of the light emitting device 10 of the present embodiment can manufacture a light emitting device 10 suitable as an in-vehicle light emitting device.

[0070] (Step of arranging the light-transmitting member 26) The manufacturing method of the light emitting device 10 of the present embodiment may include a step (step S6) of arranging a light-transmitting member 26 on the light extraction surface 122 of the light emitting element 12 after a step of electrically connecting the light emitting element 12. The step of arranging the light-transmitting member 26 may include a step of arranging a light guide member 27 between the light emitting element 12 and the light-transmitting member 26. Specifically, the step of arranging the light-transmitting member 26 may include a step of arranging the light-transmitting member 26 on the light extraction surface 122 of the light emitting element 12 via the light guide member 27, and curing the light guide member 27 by heat or ultraviolet light.

[0071] (Step of covering with reflective member 15) The manufacturing method of the light emitting device 10 of the present embodiment may include a step (step S7) of covering the light emitting element 12 and the light transmissive member 26 with the reflecting member 15. In the step of covering with the reflecting member 15, the side surface 121 of the light emitting element 12 and the side surface of the light transmissive member 26 are covered with the reflecting member 15. If the side surface 121 of the light emitting element 12 is covered with the light guiding member 27, in the step of covering with the reflecting member 15, at least the light guiding member 27 covering the side surface 121 of the light emitting element 12 and the side surface of the light transmissive member 26 are covered with the reflecting member 15. In the step of covering with the reflecting member 15, the front surface 261 of the light transmissive member 26 may be covered with the reflecting member 15, or other portions may be covered by potting or the like so as not to cover the front surface 261 of the light transmissive member 26.

[0072] (Step of Exposing the Light-Transmitting Member 26) The manufacturing method for light emitting device 10 of the present embodiment may include, in the step of covering with reflective member 15, a step (step S8) of removing reflective member 15 covering front surface 261 of light-transmitting member 26 to expose front surface 261 of light-transmitting member 26, when front surface 261 of light-transmitting member 26 is covered with reflective member 15. Removal of reflective member 15 may be performed by, for example, grinding.

[0073] (Single process) The manufacturing method of the light emitting device 10 of this embodiment may include a step of cutting and individualizing the base 11 along the planned cutting lines 28a, 28b as shown in Figures 7 to 9, when the base 11 is an aggregate circuit board and a plurality of light emitting elements 12 are arranged on the base 11. For example, the cutting can be performed using a cutting blade such as a dicer or a blade, so that the cutting blade passes through the planned cutting lines 28a, 28b.

[0074] <Second embodiment> [Light emitting device] FIG. 10 is a schematic perspective view of the light emitting device according to the second embodiment, FIG. 11 is a schematic plan view of the light emitting device according to the second embodiment with the reflecting member and the light-transmitting member removed, FIG. 12 is a schematic plan view of the light emitting device according to the second embodiment, and FIG. 13 is a schematic side view of the light emitting device according to the second embodiment. The light emitting device 100 according to the second embodiment has a different configuration from the light emitting device 10 according to the first embodiment, but the light emitting device 100 according to the second embodiment can be manufactured by the same method as that of the light emitting device 10 according to the first embodiment. As shown in FIG. 10 to FIG. 13, the light emitting device 100 includes a flat base 41 that is substantially rectangular in plan view, four light emitting elements 42 that are substantially rectangular in plan view and mounted on the upper surface side (Y direction) of the base 41, four light-transmitting members 43 that are substantially rectangular in plan view and provided on the upper surface of each light emitting element 42, a reflecting member 44 that is provided on the upper surface of the base 41 and covers the side surfaces of the light emitting elements 42 and the light-transmitting members 43, and a protective member 47.

[0075] The light emitting device 100 has an external shape of a substantially rectangular parallelepiped, and a part of the upper surface of the base 41 has an area where the reflective member 44 is not provided, and at least a pair of electrodes (n-side electrode and p-side electrode) 45, 46 are disposed in the area as external connection parts that are terminals for connecting to an external power source. That is, the pair of electrodes 45, 46 are partially exposed from the reflective member 44, and the exposed parts serve as external connection parts that are terminals for connecting to the outside.

[0076] An upper surface 431 (surface on the Y-direction side) of the light-transmitting member 43 serves as the light-emitting surface of the light-emitting device 100. The light-emitting device 100 according to the second embodiment includes a plurality of light-emitting elements 42, and further includes one light-transmitting member 43 on each of the upper surfaces of the plurality of light-emitting elements 42. In other words, the light-emitting device 100 includes a plurality of light-emitting surfaces (upper surfaces 431 of the light-transmitting members 43), and a reflective member 44 is disposed between the plurality of light-transmitting members 43 in a plan view. This makes it possible to reduce light leakage between adjacent light-emitting surfaces when the plurality of light-emitting elements 42 are individually turned on.

[0077] 11, the base 41 includes a flat substrate 48 and electrodes 45, 46 arranged on the upper surface of the substrate 48, and the light-emitting element 42 is mounted on the upper surface of the base 41. In this embodiment, five external connection parts (electrodes) are provided, and the electrodes are configured so that the four light-emitting elements 42 mounted on the base 41 can be driven individually by controlling the voltage applied to these external connection parts.

[0078] The protective member 47 has a function of protecting the light emitting element 42 from damage due to ESD. The protective member 47 is arranged to connect the pair of electrodes 45, 46. The protective member 47 is covered with the reflective member 44, and can reduce absorption of light from the light emitting element 42 and the light-transmitting member 43 by the protective member 47. The protective member 47 also contains a resin having a relative dielectric constant of 3.0 or less and varistor particles.

[0079] The materials for the substrate 48, the light-emitting element 42, the light-transmitting member 43, the reflecting member 44, the electrodes 45, 46, and the protective member 47 can be the same as those for the substrate 17, the light-emitting element 12, the light-transmitting member 26, the reflecting member 15, the electrodes 18, 19, and the protective member 16 in the first embodiment, respectively.

[0080] [Manufacturing method of light emitting device] The manufacturing method of the light emitting device 100 of this embodiment includes a step of preparing a base 41 having a pair of electrodes 45, 46, and a step of preparing a protective member 47 containing a resin having a relative dielectric constant of 3.0 or less and varistor particles. The manufacturing method also includes a step of disposing the protective member 47 so as to connect the pair of electrodes 45, 46 and curing it, a step of applying a voltage with a maximum current limited to 3 mA or more and 5 mA or less to the cured protective member 47, or a step of applying a voltage of 8 kV or more and 10 kV or less in accordance with JEDEC JESD22-A114 to energize the cured protective member 47, and a step of electrically connecting the light emitting element 42 to the pair of electrodes 45, 46. In the step of preparing the protective member 47, the protective member 47 contains 70% by weight or more of varistor particles relative to the entirety of the protective member 47.

[0081] The above-described method for manufacturing the light emitting device 100 provides the same effects as the light emitting device 10 according to the first embodiment.

[0082] (Step of Preparing Base 41) 11, the manufacturing method of the light emitting device 100 of this embodiment includes a step of preparing a base 41 having a pair of electrodes 45, 46. Details of the base 41 are similar to those of the base 11 in the above-mentioned light emitting device 10, and therefore a description thereof will be omitted here. Hereinafter, descriptions of members common to the light emitting device 10 will be omitted, as they are similar to those of the light emitting device 100.

[0083] In the step of preparing the base 41, the distance between a pair of adjacent electrodes 45, 46 is preferably 30 μm or more and 70 μm or less. Here, the distance between a pair of adjacent electrodes 45, 46 means the shortest distance. As a result, the method for manufacturing the light emitting device 100 of this embodiment can manufacture the light emitting device 100 with a lower varistor voltage.

[0084] (Step of preparing protective member 47) The process of preparing the protective member 47 is similar to the process of preparing the protective member 16 in the method of manufacturing the light emitting device 10 according to the first embodiment, and therefore a description thereof will be omitted.

[0085] (Step of placing and hardening protective member 47) The manufacturing method of the light emitting device 100 of this embodiment includes a step of arranging and hardening the protective member 47 so as to connect the pair of electrodes 45, 46. In the example shown in Fig. 11, the protective members 47 are arranged in four places so as to connect adjacent electrodes. The method of arranging the protective member 47 and the method of hardening the protective member 47 are similar to the step of arranging and hardening the protective member 16 of the first embodiment, and therefore a description thereof will be omitted.

[0086] (Step of applying current to the hardened protective member 47) The process of passing a current through the hardened protective member 47 is similar to the process of passing a current through the hardened protective member 16 in the method for manufacturing the light emitting device 10 according to the first embodiment, and therefore a description thereof will be omitted.

[0087] (Step of electrically connecting the light emitting element 42) The manufacturing method of the light emitting device 100 of this embodiment includes a step of electrically connecting the light emitting element 42 to the pair of electrodes 45, 46. That is, the step of electrically connecting the light emitting element 42 is a step of mounting the light emitting element 42 on the base 41. In the step of electrically connecting the light emitting element 42, the positive and negative electrodes of the light emitting element 42 and the pair of electrodes 45, 46 of the base 41 are connected with a conductive adhesive member. As the conductive adhesive, the same conductive adhesive as in the first embodiment can be used.

[0088] In the step of electrically connecting the light emitting element 42, the rated current of the light emitting element 42 may be 10 mA or more and 1500 mA or less. As a result, the manufacturing method of the light emitting device 100 of the present embodiment can manufacture the light emitting device 100 suitable as an in-vehicle light emitting device.

[0089] (Step of arranging the light-transmitting member 43) The manufacturing method for the light emitting device 100 of this embodiment may include, after the step of electrically connecting the light emitting elements 42, a step of arranging a light-transmitting member 43 on the light extraction surface 421 of the light emitting elements 42, as shown in Fig. 12 and Fig. 13. The step of arranging the light-transmitting member 43 may include a step of arranging the light-transmitting member 43 on the light extraction surface 421 of the light emitting elements 42 via an adhesive resin and curing the adhesive resin by heat or ultraviolet light.

[0090] The manufacturing method of the light emitting device 100 of the present embodiment can include a step of covering the light emitting element 42 and the light-transmitting member 43 with a reflecting member 44. Furthermore, in the step of covering with the reflecting member 44, if the upper surface 431 of the light-transmitting member 43 is covered with the reflecting member 44, the method can include a step of removing the reflecting member 44 covering the upper surface 431 of the light-transmitting member 43 and exposing the upper surface 431 of the light-transmitting member 43. The step of covering with the reflecting member 44 and the step of exposing the light-transmitting member 43 are similar to the corresponding steps in the first embodiment, and therefore descriptions thereof will be omitted. EXAMPLES

[0091] The embodiment will now be described in more detail with reference to examples.

[0092] First, the substrate shown in FIG. 7 and FIG. 8 was prepared. A BT resin (bismaleimide triazine resin) substrate with a thickness of 0.3 mm was used as the substrate, and the n-side first wiring and the p-side first wiring were formed on the front surface of the substrate, and the n-side second wiring and the p-side second wiring were formed on the back surface of the substrate with copper foil with a thickness of 18 μm, respectively. As a surface treatment, Ni was plated with a thickness of 3 μm, Pd with a thickness of 0.05 μm, and Au with a thickness of 0.15 μm. At this time, the n-side first wiring and the p-side first wiring and the n-side second wiring and the p-side second wiring were electrically connected via the n-side third wiring and the p-side third wiring arranged in the through hole penetrating the front and back surfaces of the substrate. In addition, the distance between the n-side first wiring and the p-side first wiring was set to 0.2 mm, and the shortest distance between the n-side second wiring and the p-side second wiring was set to 50 μm.

[0093] Next, as shown in Table 1, the resin, varistor particles, insulating filler, and platinum-based catalyst were manually stirred for 3 minutes, and then mixed for 3 minutes at 1200 rpm using an automatic revolution mixer (Thinky, product name: ARV-310LED) to prepare a protective member. In Table 1, the resin, varistor particles, and insulating filler are shown as their content relative to the protective member, and the platinum-based catalyst is shown as their content relative to the resin. Details of each raw material shown in Table 1 are as follows.

[0094] (A) Resin A-1: Dimethyl silicone (relative dielectric constant 2.9) containing 10 ppm by weight of platinum as a platinum catalyst A-2: Epoxy resin (dielectric constant 5.0) A-3: Dimethyl silicone containing 2 ppm by weight of platinum as a platinum catalyst (relative dielectric constant 2.7) (B) Varistor particles B-1: Ceramic particles (particle size 20μm to 35μm) whose main component is zinc oxide and contains Bi, Co, Sb, Mn, and Ni as additives. (C) Insulating filler C-1: Zinc oxide particles (particle size 0.2 μm to 0.6 μm) C-2: Porous silica particles (particle size 2.0 μm to 3.0 μm)

[0095] [Table 1]

[0096] Next, a protective material was applied to the back surface of the substrate by screen printing to a thickness of approximately 0.1 mm so as to connect the n-side second wiring and the p-side second wiring, and the applied protective material was hardened by heating at 150°C for 4 hours.

[0097] Then, as shown in FIG. 9, a voltage of 10 kV was applied once in accordance with JEDEC JESD22-A114 between wires 29a and 29b, between wires 29b and 29c, and between wires 29c and 29d, in that order, to pass a current through the hardened protective member (process of passing a current through the protective member).

[0098] Next, the light-emitting element was electrically connected to the n-side electrode and p-side electrode of the base. Specifically, the positive electrode of the light-emitting element was connected to the p-side first wiring, which is the p-side electrode of the base, and the negative electrode of the light-emitting element was connected to the n-side first wiring, which is the n-side electrode of the base, using gold-tin solder. As a result, the light-emitting element was electrically connected to the n-side second wiring, which is the n-side electrode of the base, and the p-side second wiring, which is the p-side electrode of the base, via the through-hole.

[0099] After mounting the light-emitting element on the base as described above, a light-transmitting member was placed on the light extraction surface of the light-emitting element via an adhesive resin as a light-guiding member, and the adhesive resin was cured. As the light-transmitting member, a laminate of a phosphor resin layer made of a silicone resin containing a phosphor and a light-transmitting resin layer made of a resin not containing a phosphor was used. Then, the side surface of the light-emitting element, the outer surface of the light-transmitting member, and the front surface of the base were covered with a reflective member. As the reflective member, a silicone resin containing titanium oxide was used. Then, the reflective member covering the front surface of the light-transmitting member was ground and removed to expose the front surface of the light-transmitting member.

[0100] Finally, the reflective member and the base were cut with a dicer along the planned cutting lines surrounding each light-transmitting member when viewed from the front side of the light-transmitting member to separate them, thereby obtaining a side-emitting light-emitting device.

[0101] The voltage-current characteristics of the obtained light-emitting device were evaluated as follows. The evaluation results are shown in Table 2.

[0102] [Table 2]

[0103] In Table 2 and Table 3 described later, "initial" refers to the stage during the fabrication of the light-emitting device, after the step of disposing and curing the protective member and before the step of passing a current through the protective member, "after fabrication" refers to the stage after the light-emitting device is fabricated, and "5V leakage" refers to the value of leakage current when a voltage of 5V is applied to the light-emitting device.

[0104] As shown in Table 2, the varistor voltage of the light emitting devices of Examples 1 to 4 was reduced by up to 61% compared to the initial value, and the leakage current at 5 V was 6.5 μA or less. From the results of Examples 1 to 4 and Comparative Example 1, it was confirmed that the leakage current at 5 V can be reduced by including an insulating filler in the protective member. On the other hand, although the varistor voltage of the light emitting devices of Comparative Examples 1 and 2 was lower than the initial value, the leakage current at 5 V was up to 3600 μA, which was significantly larger than that of Examples 1 to 4.

[0105] In the protective member of Comparative Example 3, in which the content of the platinum component as a platinum-based catalyst contained in the resin component was 2 ppm by weight, the curing of the resin was inhibited and the protective member was not cured sufficiently. On the other hand, in the protective members of Examples 1 to 4 and Comparative Example 1, in which the content of the platinum component as a platinum-based catalyst contained in the resin component was 10 ppm by weight, the protective member was cured sufficiently.

[0106] Furthermore, it was confirmed that the nonlinear coefficient (α) after fabrication of the light emitting devices of Examples 1 to 4 was maintained or increased from the initial value, and had varistor properties. On the other hand, the nonlinear coefficient of the light emitting devices of Comparative Examples 1 and 2 was greatly reduced from the initial value.

[0107] Next, a light-emitting device was prepared in the same manner as in Example 2 except for the step of passing a current through the protective member, and in the step of passing a current through the protective member, a voltage of 10 kV was applied once in accordance with JEDEC JESD22-A114 to pass a current through the protective member to produce a light-emitting device of Example 5, and a voltage with a maximum current limited to 3 mA or more and 5 mA or less was applied using a curve tracer to pass a current through the protective member to produce a light-emitting device of Example 6, and the voltage-current characteristics of the obtained light-emitting devices were evaluated. The evaluation results are shown in Table 3.

[0108] [Table 3]

[0109] As shown in Table 3, in both the light-emitting devices of Examples 5 and 6, the varistor voltage was reduced by approximately 60% compared to the initial state, and the leakage current at 5 V was 50 μA or less, confirming that sufficient ESD resistance was obtained for practical use.

[0110] For each of the light emitting devices of Examples 5 and 6, a voltage of 2 kV to 10 kV was applied between the n-side electrode and the p-side electrode in 2 kV steps, 20 times for each step, in accordance with JEDEC JESD22-A114 (additional HBM test). Then, the voltage-current characteristics of each light emitting device were evaluated. Figure 14 shows the initial voltage-current characteristics of the light emitting devices of Examples 5 and 6, Figure 15 shows the voltage-current characteristics after the fabrication of the light emitting devices of Examples 5 and 6, and Figure 16 shows the voltage-current characteristics of the light emitting devices of Examples 5 and 6 after the additional HBM test.

[0111] As shown in Figures 14 to 16, no significant changes were observed in the voltage-current characteristics of either the light-emitting device of Examples 5 or 6 even after the additional HBM test, confirming that the voltage-current characteristics after fabrication were stably maintained.

[0112] Next, a light emitting device was produced in the same manner as in Example 2 except for the step of passing a current through the protective member, and a light emitting device of Example 7 was produced in which a voltage of 10 kV was applied once in accordance with JEDEC JESD22-A114 to pass a current through the protective member in the step of passing a current through the protective member, and a light emitting device of Comparative Example 4 was produced in the same manner as in Example 7 except that it did not include a protective member and was not subjected to a current passing process. Note that FIG. 17 is a circuit diagram showing the circuit configuration of the light emitting device of Example 7.

[0113] For the light emitting devices of Example 7 and Comparative Example 4, a voltage of 2 kV to 10 kV was applied in the reverse direction in steps of 2 kV to check for the presence or absence of damage to the light emitting elements due to static electricity, and the evaluation was performed based on the following criteria: A: no damage, B: damage. The results are shown in Table 4.

[0114] [Table 4]

[0115] As shown in Table 4, in the light emitting device of Comparative Example 4, the light emitting element was broken down at an applied voltage of about 2 kV, whereas in the light emitting device of Example 7, the light emitting element was not broken down even at an applied voltage of 10 kV.

[0116] (Embodiments of the present invention) The present invention includes the following aspects. <Aspect 1> providing a substrate having a pair of electrodes; preparing a protective member including a resin having a relative dielectric constant of 3.0 or less and varistor particles; disposing the protective member so as to connect the pair of electrodes and curing the protective member; energizing the cured protective member by applying a voltage with a maximum current limited to 3 mA or more and 5 mA or a voltage of 8 kV or more and 10 kV or less in accordance with JEDEC JESD22-A114; and electrically connecting a light-emitting element to the pair of electrodes. In the method for producing a light emitting device, in the step of preparing the protective member, the protective member contains 70% by weight or more of the varistor particles based on the entirety of the protective member. <Aspect 2> In the step of preparing the protective member, the protective member is prepared, the protective member containing 0.5% by weight or more and 2.5% by weight or less of an insulating filler with respect to the protective member; In the method for producing a light emitting device according to embodiment 1, the insulating filler contains at least one selected from the group consisting of zinc oxide and silicon oxide. <Aspect 3> In the step of preparing the protective member, the protective member is prepared, the protective member containing 0.5% by weight or more and 2.5% by weight or less of an insulating filler with respect to the protective member; 3. The method for producing a light emitting device according to aspect 1 or 2, wherein the insulating filler includes at least one selected from the group consisting of porous particles and hollow particles. <Aspect 4> This is a method for manufacturing a light emitting device according to any one of aspects 1 to 3, wherein in the step of preparing the protective member, the varistor particles are ceramics mainly composed of zinc oxide and further contain at least one selected from bismuth, cobalt, antimony, and manganese. <Aspect 5> In the method for manufacturing a light emitting device according to aspect 4, in the step of preparing the protective member, the protective member is prepared which contains a platinum-based curing catalyst of 4 ppm by weight or more relative to the resin. <Aspect 6> In the method for manufacturing a light emitting device according to any one of Aspects 1 to 5, in the step of preparing the protective member, the protective member contains the resin that contains dimethyl silicone. <Aspect 7> In the method for manufacturing a light emitting device according to any one of Aspects 1 to 6, in the step of electrically connecting the light emitting elements, the rated current of the light emitting elements is 10 mA or more and 1500 mA or less. <Aspect 8> In the method for manufacturing a light emitting device according to any one of aspects 1 to 7, in the step of preparing a base, the distance between the pair of electrodes is not less than 30 μm and not more than 70 μm. [Explanation of symbols]

[0117] 10, 100 Light emitting device 11, 41 Substrate 12, 42 Light emitting element 18, 19, 45, 46 electrodes 16, 47 Protective material 26, 43 Translucent member

Claims

1. providing a substrate having a pair of electrodes; preparing a protective member including a resin having a relative dielectric constant of 3.0 or less and varistor particles; disposing the protective member so as to connect the pair of electrodes and curing the protective member; energizing the cured protective member by applying a voltage with a maximum current limited to 3 mA or more and 5 mA or a voltage of 8 kV or more and 10 kV or less in accordance with JEDEC JESD22-A114; and electrically connecting a light-emitting element to the pair of electrodes. A method for manufacturing a light emitting device, wherein in the step of preparing the protective member, the protective member contains 70% by weight or more of the varistor particles based on the entirety of the protective member.

2. In the step of preparing the protective member, the protective member is prepared, the protective member containing an insulating filler in an amount of 0.5% by weight or more and 2.5% by weight or less with respect to the protective member; The method for manufacturing a light emitting device according to claim 1 , wherein the insulating filler contains at least one selected from the group consisting of zinc oxide and silicon oxide.

3. In the step of preparing the protective member, the protective member is prepared, the protective member containing an insulating filler in an amount of 0.5% by weight or more and 2.5% by weight or less with respect to the protective member; The method for manufacturing a light emitting device according to claim 1 , wherein the insulating filler includes at least one selected from the group consisting of porous particles and hollow particles.

4. 2. The method for manufacturing a light emitting device according to claim 1, wherein in the step of preparing the protective member, the varistor particles are ceramics whose main component is zinc oxide, and further contain at least one element selected from the group consisting of bismuth, cobalt, antimony, and manganese.

5. 2 . The method for manufacturing a light emitting device according to claim 1 , wherein in the step of preparing the protective member, the protective member prepared contains a platinum-based curing catalyst in an amount of 4 ppm by weight or more relative to the resin.

6. The method for manufacturing a light emitting device according to claim 1 , wherein in the step of preparing the protective member, the protective member includes the resin containing dimethyl silicone.

7. 2. The method for manufacturing a light emitting device according to claim 1, wherein in the step of electrically connecting the light emitting elements, the rated current of the light emitting elements is 10 mA or more and 1500 mA or less.

8. 2 . The method for manufacturing a light emitting device according to claim 1 , wherein in the step of preparing the base, the distance between the pair of electrodes is 30 μm or more and 70 μm or less.

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