Light-emitting device, inorganic member, and method for manufacturing light-emitting device

Abstract

To provide a light-emitting device including a light reflective member that has light reflectivity and high heat dissipation properties.SOLUTION: A light-emitting device includes a light emitting element 4 and a light reflective member 5 that includes an inorganic member and reflects light emitted from the light emitting element. The inorganic member includes silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a light-emitting device, an inorganic member, and a method for manufacturing a light-emitting device and a method for manufacturing the same.

Background Art

[0002] Patent Document 1 discloses a light-emitting device having a light-emitting element such as an LED and a light-reflective coating member that covers a part of the light-emitting element. Patent Document 1 discloses, as the light-reflective coating member, a material containing a reflective material containing a white pigment such as titanium oxide, zinc oxide, tantalum oxide, niobium oxide, zirconium oxide, or aluminum oxide in a base material of a heat-resistant resin such as a silicone resin or an inorganic binder.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, such a light-reflective coating member (hereinafter referred to as a light-reflective member) formed by including such an inorganic binder still has room for improvement. As an example, since the coating member that covers the light-emitting element is irradiated with light from the light-emitting element and heat is generated, further improvement in heat dissipation is required.

[0005] Therefore, an object of the present disclosure is to provide a light-emitting device including a light-reflective member having light reflectivity and high heat dissipation, an inorganic member capable of improving the performance of the light-reflective member, and a method for manufacturing a light-emitting device including a light-reflective member having high heat dissipation.

Means for Solving the Problems

[0006] The light-emitting device according to the present disclosure is a light-emitting element, and An inorganic member, and a light-reflective member that reflects light emitted from the light-emitting element, having The inorganic member contains silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal. and contains

[0007] One form of the inorganic member according to the present disclosure contains silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal. Another form of the inorganic member according to the present disclosure contains silicon oxide, an alkali metal, an oxide containing an alkaline earth metal, and water.

[0008] In addition, a method for manufacturing a light-emitting device according to the present disclosure includes a step of preparing a light-emitting element including a semiconductor structure, a step of mixing silicon oxide powder, an oxide containing an alkaline earth metal, and an alkaline solution containing an alkali metal to prepare a mixture, a step of applying the mixture to a region irradiated with light from the light-emitting element, and a step of forming a light-reflective member by curing the mixture by heating.

Advantages of the Invention

[0009] According to the light-emitting device of the present disclosure, it is possible to provide a light-emitting device including a light-reflective member capable of improving heat dissipation. In addition, according to one form of the inorganic member of the present disclosure, it is possible to provide an inorganic member capable of improving the performance of the light-reflective member. Furthermore, according to the method for manufacturing a light-emitting device, it is possible to provide a method for manufacturing a light-emitting device including a light-reflective member with improved performance.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 4A

Figure 4B

Figure 4C

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments and examples for carrying out the present invention will be described with reference to the drawings. The light-emitting device and the manufacturing method of the light-emitting device described below are for embodying the technical idea of the present invention, and unless otherwise specifically described, the present invention is not limited to the following. In the respective drawings, members having the same function may be denoted by the same reference numerals. For the sake of easy explanation or understanding of the gist, they may be shown separately in embodiments or examples for convenience. However, partial substitution or combination of the configurations shown in different embodiments or examples is possible. In the following embodiments and examples, descriptions of matters common to the foregoing are omitted, and only the different points will be described. In particular, for the same operational effects due to the same configuration, they will not be sequentially mentioned for each embodiment or example. The size, positional relationship, etc. of the members shown in each drawing may be exaggerated for clarity of explanation.

[0012] The light-emitting device according to an embodiment of the present disclosure includes a light-emitting element and a light-reflective member that includes an inorganic member and reflects light emitted from the light-emitting element, and the inorganic member includes silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal. Here, the light-reflective member referred to in the present application (1) is a light-reflective member made of an inorganic member, where the inorganic member itself has light reflectivity, and (2) is a light-reflective member that mainly functions as a support and includes a light-reflective material, and is included. For example, (1) the light-reflective member made of an inorganic member is such that the inorganic member itself is, for example, white and has light reflectivity. Also, (2) the light-reflective member including a light-reflective material functions as a light-reflective member by imparting light reflectivity by the light-reflective material even if the inorganic member that is a support has light transmissibility. Furthermore, the inorganic member itself that functions as a support may have light reflectivity. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0013] Embodiment 1 As shown in FIG. 1, the light-emitting device 1 according to the present embodiment includes a light-emitting element 4 and a light-reflective member 5 that covers the light-emitting element 4. Here, the light-emitting device 1 may include a light-transmissive member 6 disposed to cover the upper surface 4a of the light-emitting element 4. In the following Embodiment 1, the light-emitting device 1 including the light-transmissive member 6 will be described. The light-emitting element 4 includes a semiconductor laminate 2 and a pair of electrodes 3 provided on the lower surface side of the semiconductor laminate 2. A part of the surface of the light-transmissive member 6 is exposed from the light-reflective member 5, and the surface exposed from the light-reflective member 5 constitutes the light-emitting surface 1a of the light-emitting device 1. The light-reflective member 5 is disposed so as to cover a part of the side surface and the bottom surface of the light-emitting element 4 (a part of the bottom surface of the semiconductor laminate 2 where the electrode 3 is not formed) and a part of the side surface and the bottom surface of the light-transmissive member 6. Hereinafter, each configuration of the light-emitting device according to Embodiment 1 will be described in detail.

[0014] (Light-emitting element) As the light-emitting element 4, a semiconductor light-emitting element such as a light-emitting diode can be used. The semiconductor laminate 2 included in the light-emitting element 4 includes, for example, an n-type semiconductor layer, a p-type semiconductor layer, and a light-emitting portion disposed between the n-type semiconductor layer and the p-type semiconductor layer. The light-emitting element 4 includes a growth substrate 7 (for example, a sapphire substrate) for growing a semiconductor layer on the surface of the semiconductor laminate 2 opposite to the surface on which the electrode 3 is formed. However, the growth substrate may be removed after the semiconductor layer is formed. The n-type semiconductor layer, the p-type semiconductor layer, and the light-emitting layer are, for example, composed of a nitride semiconductor (In x Al y Ga 1-x-y N (0 ≦ x, 0 ≦ y, x + y ≦ 1)), and visible light or ultraviolet light can be emitted by appropriately setting the composition ratio. The emission peak wavelength of the light-emitting element 4 is, for example, 260 nm or more and 630 nm or less. The light-emitting element 4 emits, for example, ultraviolet light or blue light. The pair of electrodes 3 provided on the lower surface side of the semiconductor laminate 2 are a p-electrode and an n-electrode.

[0015] (Light-transmissive member) The light-transmissive member 6 may contain a resin or may be an inorganic material. If the light-transmissive member 6 is an inorganic material, since it has higher heat resistance than a light-transmissive member containing a resin, a light-emitting device with high heat resistance can be manufactured. As the inorganic material, for example, glass, sapphire, etc. can be used. The light-transmissive member 6 can contain a wavelength conversion material such as a phosphor. When the light-transmissive member 6 is an inorganic material base containing a phosphor, for example, as the phosphor, YAG (yttrium aluminum garnet) can be used, and as the base, alumina or silica can be used. Note that the light-transmissive member 6 does not necessarily have to contain a wavelength conversion material. In this case, the light from the light-emitting element 4 is emitted to the outside from the light-emitting surface 1a without being wavelength-converted.

[0016] (Light-reflective member) In the present embodiment, the light-reflective member 5 exposes the lower surface 3a of the electrode 3 of the light-emitting element 4 and the upper surface 6a of the light-transmissive member 6, and covers the light-emitting element 4 and the light-transmissive member 6. Here, "covering" means not only a state where the light-reflective member 5 is disposed in contact with the light-emitting element 4 and / or the light-transmissive member 6, but also a state where the light-reflective member 5 is disposed with another member or a space (for example, an air layer) interposed between the light-emitting element 4 and / or the light-transmissive member 6. Hereinafter, the same can be said when expressions such as "cover", "coat", "covered" are used in this specification. The upper surface 6a of the light-transmissive member 6 exposed from the light-reflective member 5 is the light-emitting surface 1a of the light-emitting device 1. When the light-transmissive member 6 is not provided, the light-reflective member 5 is disposed, for example, with the upper surface 4a of the light-emitting element 4 and the lower surface 3a of the electrode 3 exposed. In this case, the upper surface 4a of the light-emitting element 4 is the light-emitting surface of the light-emitting device 1.

[0017] The light-reflective member 5 includes an inorganic member 15 and reflects the light emitted from the light-emitting element 4. As schematically shown in FIG. 2, the inorganic member 15 includes a support member 12 containing silicon oxide and an alkali metal, and a hydroxide 11 containing an alkaline earth metal. By including the hydroxide 11, the light-reflective member 5 improves the performance it has. For example, by filling at least a part of the voids generated during the manufacturing process with the hydroxide 11, the porosity is reduced and the thermal conductivity of the light-reflective member 5 is improved. Specifically, when forming a light-reflective member using a raw material containing silicon oxide, an alkali metal, and further an alkaline earth metal, the hydroxide 11 containing the alkaline earth metal is distributed within the inorganic member 15, and compared with the case of forming a light-reflective member containing silicon oxide and an alkali metal without containing an alkaline earth metal, the open porosity can be made lower. For example, the open porosity of the formed light-reflective member can be made 40% or less and 20% or more. Also, the alkali metal ions generated during the manufacturing process can be efficiently removed in the water washing process described later, and the occurrence of ion migration can be suppressed.

[0018] Here, the open porosity is an index indicating the degree of porosity and is defined by the following formula 1.

[0019] Open porosity (%) = [(apparent density - bulk density) / bulk density] × 100 ··· Formula 1

[0020] The "apparent density" in Formula 1 is the density obtained by obtaining the volume V1 of the member to be measured excluding the unevenness and voids connected to the outside and dividing the weight W of the member to be measured by the volume V1. Therefore, the volume V1 includes voids not connected to the outside and is not the true density of the member to be measured. This apparent density can be calculated, for example, based on the weight of the member to be measured in air (weight in air) and the weight of the member to be measured in water (weight in water), taking into account the density of water. Here, the weight in water of the member is the weight measured by submerging the member in water and performing vacuum pumping. The unevenness and voids connected to the outside are filled with water, but the voids not connected to the outside are not filled with water. In addition, the "bulk density" in Formula 1 is the density obtained by dividing the weight W of the member to be measured, which includes unevenness and voids connected to the outside, by the volume V2 of the member to be measured. This bulk density can be calculated, for example, by measuring the volume V2 and weight W of the formed light-reflective member and based on the measured volume V2 and weight W. The volume V2 of the formed light-reflective member can be measured with a laser microscope.

[0021] Moreover, the alkali metal preferably contains potassium or sodium, and more preferably contains potassium. The alkali metal is the metal contained in the alkali solution used in the step of forming the light-reflective member 5. The alkali solution is a solution in which an alkali metal is dissolved in a solvent. As the solvent, for example, water can be used. In that case, the alkali solution is, for example, a potassium hydroxide solution or a sodium hydroxide solution. By the alkali metal containing potassium or sodium, for example, a white light-reflective member 5 having light reflectivity including K2SiO3 or Na2SiO3 can be formed, and for example, the light-reflective member 5 can be formed without including a light-reflective material. Further, when the white light-reflective member 5 having light reflectivity containing potassium includes a light-reflective material, it becomes possible to form a light-reflective member 5 with higher light reflectivity.

[0022] In addition, the alkaline earth metal preferably contains any one of calcium, magnesium, and beryllium. By the alkaline earth metal containing any one of calcium, magnesium, and beryllium, the hydroxide 11 containing the alkaline earth metal can be made white, and the light reflectivity of the light reflecting member 5 can be improved. The hydroxide 11 containing any one of calcium, magnesium, and beryllium is, for example, crystals of Ca(OH), crystals of Mg(OH), or crystals of Be(OH). The alkaline earth metal more preferably contains calcium. By the alkaline earth metal containing calcium, a white hydroxide 11 with higher light reflectivity can be obtained compared to the case where other alkaline earth metals are contained, and the light reflectivity of the light reflecting member 5 can be further improved. In addition, the content of the hydroxide 11 containing the alkaline earth metal in the light reflecting member 5 is preferably 0.1% by weight or more and 8.7% by weight or less. By setting the content of the hydroxide 11 containing the alkaline earth metal in the light reflecting member 5 to 0.1% by weight or more and 8.7% by weight or less, the thermal conductivity of the light reflecting member 5 can be further increased compared to the case where the content of the hydroxide 11 containing the alkaline earth metal is outside the above range.

[0023] The light reflecting member 5 preferably further has a light reflecting material 13 containing at least one of, for example, boron nitride, titanium oxide, zirconium oxide, and aluminum oxide, whereby the light reflectivity of the light reflecting member 5 can be further improved. Here, in addition to the function of reflecting light, boron nitride and aluminum oxide can function as aggregates that suppress the expansion or contraction of the light reflecting member 5 due to the heat generation of the light emitting element 4 when the light emitting device 1 is driven. In addition, titanium oxide and zirconium oxide can function as light scattering materials. For the light reflecting material 13 that functions as an aggregate, it is preferable to use a material having a linear expansion coefficient closer to that of the light emitting element 4 than that of the support member 12 in the light reflecting member 5.

[0024] Further, the weight ratio of the light reflecting material 13 contained in the light reflective member 5 is, for example, 1 time or more and 4 times or less the weight of the silicon oxide contained in the light reflective member 5. Within this range, shrinkage during curing of the mixture can be suppressed. If the weight ratio of the light reflecting material 13 increases, there is a risk that the curability will decrease. On the other hand, if the weight ratio of the silicon oxide increases, shrinkage due to curing becomes large, and there is a risk of cracks occurring during curing. The average particle size of the silicon oxide is, for example, 0.1 μm or more and 10 μm or less. When the average particle size of the silicon oxide is within this range, the density per volume of the raw materials (light reflecting material 13 and silicon oxide) can be improved, so that the strength of the light reflective member 5 can be increased. When the light reflective member 5 contains the light reflecting material 13 that functions as an aggregate, it is desirable that the average particle size of the silicon oxide is smaller than the average particle size of the light reflecting material 13 that functions as an aggregate. Thereby, the silicon oxide can fill the voids formed between the light reflecting materials 13 that function as aggregates during mixing. The average particle size of the silicon oxide is calculated by measuring the particle size distribution of the silicon oxide by the laser diffraction method.

[0025] The light reflecting material 13 that functions as an aggregate is preferably plate-like or flaky particles. The average aspect ratio of the plate-like or flaky light reflecting material 13 that functions as an aggregate is preferably 10 or more, more preferably 10 or more and 70 or less. Thereby, the light reflecting material 13 can function more effectively as an aggregate. As described above, the light reflecting material 13 that is plate-like or flaky particles and functions as an aggregate can suppress the expansion or contraction of the light reflective member 5 due to the heat generation of the light emitting element 4, so that the heat resistance of the light emitting device 1 can be improved. Here, the average aspect ratio of the light reflecting material 13 that functions as an aggregate can be calculated by the following method.

[0026] <Calculation method of average aspect ratio> The average aspect ratio of the light reflecting material 13 is calculated by measuring the thickness and width of the light reflecting material 13 contained in the light reflective member 5 in the cross section of the light emitting device 1. First, expose a cross-section that passes through the center of the light-emitting surface 1a of the light-emitting device 1 and is substantially orthogonal to the light-emitting surface 1a. This cross-section is exposed by cutting the light-emitting device 1.

[0027] Next, mirror-polish the exposed cross-section, photograph the mirror-polished cross-section with a scanning electron microscope (SEM), extract the cross-section of the light-reflecting material 13, and select a measurement region that includes the cross-sections of approximately 1000 light-reflecting materials 13. The number of pixels of the microscope is set to approximately 20 million pixels, and the magnification is set to 500 times to 3000 times.

[0028] Next, use image analysis software to measure the width (the length in the longitudinal direction of the cross-section of the light-reflecting material) and thickness (the length in the short transverse direction of the cross-section of the light-reflecting material) of each cross-section of the extracted light-reflecting material 13 one by one, and calculate the ratio of the width to the thickness. Then, take the average value of the measured values of the light-reflecting material 13 as the average aspect ratio. The average aspect ratio of the light-reflecting material 13 that functions as an aggregate can be appropriately set based on the material quantity that constitutes the light-reflecting material 13. When the light-reflecting material 13 is boron nitride, the average aspect ratio of the light-reflecting material 13 is, for example, 16.5 or more and 19.2 or less. When the light-reflecting material 13 is aluminum oxide, the average aspect ratio of the light-reflecting material 13 is, for example, 10 or more and 70 or less.

[0029] Also, the average particle size of the light-reflecting material 13 is set within a preferable range described later in consideration of the characteristics of the material of the light-reflecting material 13. Here, the average particle size of the light-reflecting material 13 that functions as an aggregate is calculated as follows.

[0030] <Method for calculating average particle size> The particle size of the light-reflecting material 13 that functions as an aggregate is calculated, for example, using a scanning electron microscope "TM3030Plus" manufactured by Hitachi High-Technologies Corporation. First, attach one side of the carbon double-sided tape to the sample stage of the microscope, and then place the light reflecting material 13 on the other side of the double-sided tape. Set the number of pixels of the microscope to, for example, 1.23 million pixels, set the magnification to, for example, 1000 to 2000 times, and acquire images of a predetermined number (for example, 100) of the light reflecting materials 13. Then, measure the particle size of each particle using image analysis software. In this specification, the particle size of the light reflecting material 13 is the maximum diameter of the light reflecting material 13. Next, calculate the median diameter of the measured particles, and use the calculated value as the average particle size of the light reflecting material 13. Also, the particle size of the light reflecting material 13 may be measured and calculated by extracting the cross-section of the coating member with SEM and using image analysis software.

[0031] When the light reflecting material 13 is boron nitride, the average particle size of the light reflecting material 13 is, for example, 0.6 μm or more and 43 μm or less. When the light reflecting material 13 is alumina, the average particle size of the light reflecting material 13 is, for example, 0.6 μm or more and 10 μm or less.

[0032] The light reflecting material 13 having the average particle size and average aspect ratio as described above can effectively suppress the expansion and contraction of the light reflecting member 5 due to the heat generation of the light emitting element 4, and can constitute a light emitting device 1 with high heat resistance. Also, it is preferable that the light reflecting member 5 contains boron nitride as the light reflecting material 13. When the light reflecting material 13 is boron nitride, the light reflecting material 13 can function more effectively as an aggregate.

[0033] The linear thermal expansion coefficient (Coefficient of Terminal Expansion) of the light-reflective member 5 can be set within a preferable range according to the content of the light-reflective material 13 that functions as an aggregate, the average aspect ratio of the light-reflective material 13 that functions as an aggregate, and the average particle size. The linear thermal expansion coefficient of the light-reflective member 5 can be measured, for example, by a TMA (Thermomechanical Analyzer). The linear thermal expansion coefficient of the light-reflective member 5 is preferably 0.05 ppm or more and 5 ppm or less in the temperature range of 40°C to 300°C. Thereby, when the light-emitting device 1 is used, even if the temperature of the light-reflective member 5 rises, the expansion and contraction of the light-reflective member 5 can be suppressed, and the reliability can be improved. The linear thermal expansion coefficient of the light-reflective member 5 is, for example, about 1 ppm at 180°C.

[0034] Further, the light-reflective member 5 may contain a light-reflective material 13 that functions as a scattering material instead of, or in addition to, the light-reflective material 13 that functions as an aggregate. As described above, the light-reflective material 13 that functions as a scattering material is, for example, zirconium oxide or titanium oxide. When the light-emitting element 4 emits ultraviolet light, it is preferable to contain zirconium oxide with little light absorption in the ultraviolet wavelength region. Furthermore, by including the light-reflective material 13 that functions as a scattering material in addition to the light-reflective material 13 that functions as an aggregate in the light-reflective member 5, the light reflectance of the light-reflective member 5 can be improved. Thereby, the luminance difference between the light-emitting surface of the light-emitting device 1 and the upper surface (non-light-emitting surface) of the light-reflective member 5 surrounding the light-emitting surface in a top view can be made steep, and the visibility on the light-emitting surface side of the light-emitting device 1 can be improved.

[0035] The titanium oxide used as the light-scattering material 13 may be simple titanium oxide, or may be one that has been surface-treated such as forming a film containing silicon oxide, aluminum oxide, zirconium oxide, zinc, an organic material, etc. on the surface of titanium oxide. The zirconium oxide used as the light-scattering material 13 may be simple zirconium oxide, or may be one that has been surface-treated such as forming a film containing silicon oxide, aluminum oxide, zinc, an organic material, etc. on the surface of zirconium oxide.

[0036] The average particle size of the light reflecting material 13 that functions as a scattering material to be contained in the light reflecting member 5 is preferably smaller than the average particle size of the light reflecting material 13 that functions as an aggregate. Thereby, for example, the light reflecting material 13 that functions as a scattering material can be disposed in the gaps between the light reflecting materials 13 that function as aggregates, and the light emitted from the light emitting element 4 can be prevented from being emitted to the outside of the light emitting device 1 through the gaps between the light reflecting materials 13 that function as aggregates, and the unevenness on the light emitting surface 1a of the light emitting device 1 can be improved. Here, the average particle size of the light reflecting material 13 that functions as a scattering material is measured by the laser diffraction method.

[0037] The light reflecting member 5 configured as described above includes a support member 12 containing silicon oxide and an alkali metal and a hydroxide 11 containing an alkaline earth metal, so that the voids can be filled with the hydroxide 11 to reduce the porosity, and the thermal conductivity of the light reflecting member 5 can be increased to improve the heat dissipation performance. Further, by containing the light reflecting material 13 that functions as an aggregate in the light reflecting member 5, the expansion and contraction of the light reflecting member 5 due to the heat generation of the light emitting element 4 can be suppressed, and the heat resistance of the light emitting device 1 can be increased.

[0038] The light emitting device 1 of Embodiment 1 configured as described above can suppress the temperature rise of the light emitting device 1 by efficiently dissipating the heat generated by the light emitting element 4 and the like, and can provide a highly reliable light emitting device. Further, in the light emitting device 1 of Embodiment 1, by containing the light reflecting material 13 that functions as an aggregate in the light reflecting member 5, the difference in the linear expansion coefficient between the light reflecting member 5 and the light emitting element 4 can be reduced, the performance deterioration can be reduced even when repeatedly used for a long time, and a highly reliable light emitting device can be provided.

[0039] Embodiment 2 As shown in FIGS. 3A to 3C, the light-emitting device 100 according to Embodiment 2 includes a substrate 35, a light-emitting element 4, and a light-reflective member 55. The light-emitting element 4 and the light-reflective member 55 are disposed on the substrate 35. The light-emitting element 4 includes a semiconductor laminate 2. The side surface of the semiconductor laminate 2 is separated from the light-reflective member 55. The light-emitting device 100 may further include a translucent member 60 and a protective element 80. In FIGS. 3B and 3C, for ease of understanding the configurations of the substrate 35, the light-emitting element 4, and the light-reflective member 55, the translucent member 60 is shown by a dashed line, and the configuration when the translucent member 60 is seen through is shown by a solid line. Hereinafter, each member of the light-emitting device 100 of Embodiment 2 will be described.

[0040] (Substrate) The substrate 35 includes a bottom portion 32 that defines a recess 31 and a wall portion 33. The recess 31 is a space surrounded by the bottom portion 32 and the wall portion 33. The bottom portion 32 and the wall portion 33 may be made of the same material or may be made of different members respectively. The base material 30 of the substrate 35 can be formed of a single material such as an insulating material such as glass, ceramics, resin, wood, pulp, etc., a semiconductor, a conductive material such as a metal (for example, copper, silver, gold, aluminum, etc.), and a composite material thereof. In particular, the base material 30 is preferably a metal, ceramics, etc., and more preferably ceramics which is an inorganic material. Examples of the ceramics include alumina, aluminum nitride, silicon nitride, mullite, etc., and aluminum nitride having particularly high heat dissipation is preferable.

[0041] The substrate 35 includes a conductive member 40. As shown in FIG. 3A, the conductive member 40 includes a wiring layer 41 and an external electrode 42. The wiring layer 41 is disposed on the upper surface 32a of the bottom portion 32 and is electrically connected to an electrode 3 of the light-emitting element 4 described later. The external electrode 42 is disposed on the lower surface 32b of the bottom portion 32 and is electrically connected to an external terminal. The wiring layer 41 and the external electrode 42 are electrically connected through a via (through hole) formed in the bottom portion 32. Further, as shown in FIGS. 3B and 3C, the wiring layer 41 includes an anode-side wiring layer 44 and a cathode-side wiring layer 45.

[0042] The substrate 35 has an identification mark 43 disposed on the upper surface 32a of the bottom portion 32. As shown in FIGS. 3B and 3C, in a top view, the identification mark 43 is exposed from the light-reflective member 55. The light-emitting device 100 can identify the wiring layer 44 on the anode side and the wiring layer 45 on the cathode side by the identification mark 43.

[0043] In the example shown in FIG. 3A, in a cross-sectional view, the thickness of the wall portion 33 of the substrate 35 is constant. The inner surface 33a of the wall portion 33 of the substrate 35 may have a step. Also, as shown in FIGS. 3B and 3C, in a top view, the outer peripheral shape of the wall portion 33 of the substrate 35 is rectangular. Here, the rectangle means a shape including four sides and four corners, and the corners can be a right angle, a rounded shape, or a chamfered shape with an arc shape, etc. Also, the inner peripheral shape of the wall portion 33 of the substrate 35 is rectangular. The shape of the wall portion 33 is not limited to these, and any known shape may be used.

[0044] (Light-transmissive member) In the light-emitting device 100 of Embodiment 2, the configuration of the light-transmissive member 60 will be described with respect to the differences from the light-transmissive member 60 of the light-emitting device 1 of Embodiment 1, and the description of the same configuration will be omitted.

[0045] In the example shown in FIG. 3A, the light-transmissive member 60 is disposed on the upper surface 33c of the wall portion 33 of the substrate 35. The light-transmissive member 60 is, for example, a plate-like member having two main surfaces. One main surface 60a of the light-transmissive member 60 is the upper surface of the light-emitting device 100.

[0046] (Light-emitting element) The light-emitting element 4 is disposed on the bottom portion 32 of the substrate 35 within the recess 31. One light-emitting element 4 may be disposed on the bottom portion 32 of the substrate 35, or two or more light-emitting elements 4 may be disposed on the bottom portion 32 of the substrate 35. In the light-emitting device 100 of Embodiment 2, the configuration other than the arrangement of the light-emitting element 4 is the same as that of Embodiment 1, and the description of the specific configuration will be omitted.

[0047] As shown in FIG. 3A, a pair of electrodes 3 provided on the lower surface of the semiconductor laminate 2 are electrically connected to the wiring layer 41. The pair of electrodes 3 provided on the lower surface of the semiconductor laminate 2 are a p electrode and an n electrode.

[0048] Note that the shape of the light-emitting element 4 in a top view shown in FIGS. 3B and 3C is rectangular. However, the shape of the light-emitting element 4 in a top view may be any known shape.

[0049] (Protective element) The protective element 80 can be disposed on the bottom portion 32 of the substrate 35. The protective element 80 is, for example, a Zener diode. The lower surface of the protective element 80 has a lower electrode. The lower electrode of the protective element 80 is joined to the wiring layer 45 on the cathode side via, for example, solder or a conductive paste, and is electrically connected to the wiring layer 45 on the cathode side. An upper electrode is disposed on the upper surface of the protective element 80. The upper electrode of the protective element 80 is electrically connected to the wiring layer 44 on the anode side via a conductive wire 81. In the example shown in FIG. 3C, the protective element 80 is covered with a light-reflective member 55. By covering the protective element 80 with the light-reflective member 55, it is possible to prevent a decrease in the light extraction efficiency of the light-emitting device 100 due to the light emitted from the light-emitting element 4 being absorbed by the protective element 80.

[0050] (Light-reflective member) In the light-emitting device 100 according to Embodiment 2, the configuration of the light-reflective member 55 will be described with respect to the differences from the light-reflective member 5 of the light-emitting device 1 according to Embodiment 1, and the description of the configuration similar to that of the light-reflective member 5 will be omitted. The light-reflective member 55 reflects the light emitted from the light-emitting element 4 in the light extraction direction. The direction in which the light reflected by the light-reflective member 5 is extracted from the light-emitting device 100 is above the substrate 35. As shown in FIG. 3A, the light-reflective member 55 is disposed on the bottom portion 32 of the substrate 35 along the inner surface 33a of the wall portion 33 of the substrate 35.

[0051] As shown in FIG. 3B, the light-reflective member 55 is continuously arranged so as to surround the entire area around the light-emitting element 4. In the light-emitting device 100, in a top view, the outer peripheral shape of the light-emitting element 4 and the recess 31 are rectangular, and the light-emitting element 4 is arranged in the recess 31 such that the side surfaces of the light-emitting element 4 and the inner side surfaces 33a of the wall portions 33 facing the side surfaces are parallel to each other.

[0052] Further, as shown in FIG. 3A, the light-reflective member 55 is arranged across the inner side surface 33a of the wall portion 33 and the upper surface 32a of the bottom portion 32 so as to have an inclined surface whose height h1 from the upper surface 32a of the bottom portion 32 decreases toward the light-emitting element 4 from the wall portion 33. The end portion P1 on the upper surface 32a side of the bottom portion 32 in the light-reflective member 55 may be at any position between the wall portion 33 and the light-emitting element 4, or may be in contact with the electrode 3 of the light-emitting element 4, but it is preferably arranged at a distance from the side surface 2a of the semiconductor laminate 2. Thereby, the light emitted from the side surface 2a of the semiconductor laminate 2 can be emitted upward by the light-reflective member 55. Here, the inclination angle of the inclined surface of the light-reflective member 55 (the angle with respect to the upper surface 32a of the bottom portion 32 of the recess 31) is set so that the light of the light-emitting device 100 is emitted at a desired light distribution angle.

[0053] In the light-emitting device 100, in the example shown in FIG. 3A, the inclined surface of the light-reflective member 55 shows a case where the shape in a cross-sectional view is a straight line, but it can be appropriately set so that the light of the light-emitting device is emitted with desired light distribution characteristics. For example, the inclined surface of the light-reflective member 55 may have a curved shape that is recessed toward the base 35 side or a curved shape that bulges toward the side surface of the light-emitting element 4 in a cross-sectional view.

[0054] In the light-emitting device 100, in the example shown in FIG. 3A, the light-reflective member 55 is arranged such that the upper end of the light-reflective member 55 is positioned below the upper end of the inner side surface 33a of the wall portion 33, but the light-reflective member 55 may be arranged such that the upper end of the light-reflective member 55 coincides with the upper end of the inner side surface 33a. Further, the light-reflective member 55 may be continuously arranged on the upper surface 33c of the wall portion 33.

[0055] In the light-emitting device 100 according to Embodiment 2 configured as described above, the heat dissipation property of the light-reflective member 55 disposed on the bottom portion 32 of the base body 35 can be enhanced along the inner surface 33a of the wall portion 33 of the base body 35. As a result, the heat generated by the light-emitting element 4 can be efficiently released, the temperature rise of the light-emitting device 1 can be suppressed, and a highly reliable light-emitting device can be provided. That is, although it is preferable that the base body 35 has high heat dissipation property, if the heat dissipation property (thermal conductivity) of the light-reflective member 55 is low even when the heat dissipation property of the base body 35 is enhanced, the heat dissipation property through the base body 35 will decrease. However, by enhancing the heat dissipation property of the light-reflective member 55, heat can be efficiently dissipated through the base body 35. In addition, the light-emitting device 100 according to Embodiment 2 configured as described above can be made inexpensive when applied to, for example, a light-emitting device that emits ultraviolet light. For example, a light-emitting element that emits ultraviolet light has a larger amount of energy of the emitted light than a light-emitting element that emits visible light, and photo-degradation of the resin easily occurs. Therefore, a ceramic base body that is highly durable against light energy is usually used. However, in the light-emitting device 100 according to Embodiment 2 configured as described above, since the portion of the surface of the base body 35 mainly irradiated with the light emitted from the light-emitting element 4 can be covered with the light-reflective member 55, a resin base body 35 can be adopted. Generally, a resin base body is less expensive than a ceramic base body. Therefore, the light-emitting device 100 according to Embodiment 2 can be made inexpensive by adopting the resin base body 35.

[0056] In the light-emitting device 100 of Embodiment 2, the light-reflective members 55 are continuously arranged so as to surround the entire area around the light-emitting element 4. However, they may be arranged separately from each other around the light-emitting element 4. For example, as shown in FIG. 3C, the light-reflective members 55 may be arranged separately from each other at the four corner portions of the inner surface 33a of the wall portion 33. Alternatively, the light-reflective member 55 may be separated into two parts, one part being continuously arranged at two adjacent corner portions out of the four corner portions of the inner surface 33a of the wall portion 33, and the other part being continuously arranged at the remaining two corner portions. In the example of the light-emitting device 100A shown in FIG. 3C, the light-reflective member 55 has a substantially triangular pyramid shape with the corners of the rectangle of the recess 31 as vertices, decreasing in height toward the bottom, and having a substantially isosceles triangle as the bottom surface. Further, as shown in FIG. 3C, in the light-emitting device 100A, in a top view, the four sides of the rectangle that is the outer peripheral shape of the light-emitting element 4 are each non-parallel to any of the sides of the rectangle that is the outer peripheral shape of the base 35. Specifically, the light-emitting element 4 is arranged such that the four side surfaces of the light-emitting element 4 face the light-reflective members 5 arranged at the four corners. That is, the angle formed by the side surface of the light-emitting element 4 and the wall portion 33 in a top view is set to be approximately 45 degrees. Thereby, the light emitted from the side surface of the light-emitting element 4 is effectively reflected by the light-reflective member 55. In the light-emitting device 100 of Embodiment 2, in a top view, the four sides of the rectangle that is the outer peripheral shape of the light-emitting element 4 may each be non-parallel to any of the sides of the rectangle that is the outer peripheral shape of the base 35.

[0057] Embodiment 3 Hereinafter, the manufacturing method of Embodiment 3 according to the present disclosure will be described. The manufacturing method of the embodiment according to the present disclosure is a step of preparing a light-emitting element including a semiconductor structure, a step of preparing a mixture by mixing silicon oxide powder, an oxide containing an alkaline earth metal, and an alkaline solution containing an alkali metal, a step of applying the mixture to a region irradiated with light from the light-emitting element, a step of forming a light-reflective member by curing the mixture by heating. Hereinafter, each step will be specifically described.

[0058] (Step of preparing a light-emitting element) In this process, a light-emitting element 4 including a growth substrate 7 (for example, a sapphire substrate) and a semiconductor laminate 2 provided on the growth substrate 7 is prepared. Here, the semiconductor laminate 2 includes an n-type semiconductor layer, a p-type semiconductor layer, and a light-emitting portion disposed between the n-type semiconductor layer and the p-type semiconductor layer. Further, the light-emitting element 4 includes an electrode 3 on the electrode formation surface of the semiconductor laminate 2 located on the opposite side of the growth substrate 7.

[0059] (Step of preparing a mixture) In this process, a powder of silicon oxide and a mixed powder obtained by mixing an oxide containing an alkaline earth metal are mixed with an alkaline solution containing an alkali metal to prepare a mixture. The mixing of the mixed powder and the alkaline solution is performed, for example, by mixing until a uniform viscosity is obtained and then performing defoaming and stirring with a stirring defoaming machine capable of stirring under reduced pressure. The average particle size of the powder of silicon oxide is, for example, 0.1 μm or more and 10 μm or less. The average particle size of the oxide containing an alkaline earth metal is, for example, 10 μm or more and 35 μm or less. The concentration of the alkaline solution is, for example, 1 mol / L or more and 8 mol / L or less. By setting the concentration of the alkaline solution within this range, the curability during heating described later can be improved. Further, the content of the oxide containing an alkaline earth metal in the mixture is preferably 0.1% by weight or more and 6.6% by weight or less. By setting the content of the oxide containing an alkaline earth metal within this range, a light-reflecting member with a low open porosity and suppressed cracking during heating can be formed.

[0060] Further, the mixture may contain a powder of a light-reflecting material. When the mixture contains a powder of a light-reflecting material, the content of the powder of the light-reflecting material is mixed, for example, at a weight ratio of 1 time or more and 4 times or less with respect to the powder of silicon oxide. The powder of the light-reflecting material is, for example, a powder of boron nitride, titanium oxide, zirconium oxide, or aluminum oxide. When the powder of the light-reflecting material to be contained is boron nitride, the average particle size of the powder of the light-reflecting material is, for example, 0.6 μm or more and 43 μm or less. When the powder of the light-reflecting material to be contained is aluminum oxide, the average particle size of the powder of the light-reflecting material is, for example, 0.6 μm or more and 10 μm or less. Further, when the powder of the light reflecting material to be contained is boron nitride or aluminum oxide, the average aspect ratio of the powder of the light reflecting material is 10 or more, desirably 10 or more and 70 or less. When the powder of the light reflecting material to be contained is, for example, titanium oxide or zirconium oxide, the average particle size of the light reflecting material is, for example, 0.01 μm or more and 70 μm or less. In addition to the light reflecting material powder of boron nitride or aluminum oxide, when containing the light reflecting material powder of boron nitride or aluminum oxide, the average particle size of the light reflecting material powder of boron nitride or aluminum oxide is, for example, smaller than the average particle size of the light reflecting material powder of boron nitride or aluminum oxide. The alkaline solution and the mixed powder are mixed, for example, at a weight ratio of 1.0:1.3 or more and 1.0:2.6 or less. By setting the weight ratio of the alkaline solution to the mixed powder within the above range, the mixed powder can be easily and uniformly mixed, and a highly strong light reflecting member can be easily formed.

[0061] (Step of applying the mixture) This step is a step of applying the mixture to a region corresponding to the region where the light reflecting member 5 shown in FIG. 1 and the light reflecting members 55 shown in FIGS. 3A to 3C are provided, and will be specifically described in the manufacturing method of the light emitting device according to Embodiment 1 and the manufacturing method of the light emitting device according to Embodiment 2 described later.

[0062] (Step of forming the light reflecting member) In this process, a mixture applied to the area irradiated with light from the light-emitting element is cured by heating to form a light-reflective member with light reflectivity. By heating, the alkali metal and silicon oxide contained in the mixture react to form a light-reflective member containing alkali metal ions. This process includes, for example, a pre-curing process of curing the mixture at a first temperature T1 and a main-curing process of curing the mixture at a second temperature T2 higher than the first temperature T1. The pre-curing process is carried out, for example, at a first temperature T1 of 80°C or higher and 100°C or lower for 10 minutes or more and 2 hours or less. The main-curing process is carried out, for example, at a second temperature T2 of 150°C or higher and 250°C or lower for 10 minutes or more and 3 hours or less. By carrying out the pre-curing process at a temperature lower than the main-curing process in this way, cracks are less likely to occur in the formed light-reflective members 5,55. Furthermore, by carrying out the pre-curing process and the main-curing process while applying pressure, the voids in the formed light-reflective member can be reduced, and the light reflectivity and thermal conductivity of the light-reflective member 5,55 can be increased. The pressure applied in the main-curing process is, for example, 1 MPa.

[0063] According to the manufacturing method of the embodiment according to the above disclosure, since a light-reflective member with excellent heat dissipation can be formed in the area irradiated with light from the light-emitting element, the temperature rise of the light-emitting device can be suppressed, and a highly reliable light-emitting device can be manufactured.

[0064] (Step of washing with water) The manufacturing method of the light-emitting device 1 of this embodiment can include a step of washing the light-reflective member 5,55 with water after the step of forming the light-reflective member 5,55. In the step of forming the light-reflective member, as described above, alkali metal ions are generated. Therefore, by washing with water, the alkali metal ions attached to the surface of the light-emitting device 1 can be removed. Thereby, a highly reliable light-emitting device 1 can be manufactured.

[0065] The manufacturing method of the light-emitting device 1 of this embodiment can include a step of drying the light-reflective member 5,55 after the step of washing with water.

[0066] Next, a method for manufacturing the light-emitting device 1 according to Embodiment 1 and a method for manufacturing the light-emitting device 100 according to Embodiment 2 will be described. In the following description, the steps of preparing a light-emitting element, preparing a mixture, preparing a mixture, and heating the mixture to cure it to form a light-reflective member are the same as those described above, and the description of these steps will be omitted or simplified.

[0067] <First Manufacturing Method> With reference to FIGS. 4A to 4C, an example (first manufacturing method) of a method for manufacturing the light-emitting device 1 according to Embodiment 1 will be described.

[0068] (Step of Mounting a Light-Emitting Element on a Mounting Substrate) First, a plurality of light-emitting elements 4 each having a light-transmissive member 6 disposed on its upper surface 4a are prepared. The light-transmissive member 6 contains a phosphor. Next, the prepared light-emitting elements 4 are mounted on a mounting substrate 20 at a predetermined interval as shown in FIG. 4A.

[0069] (Step of Applying a Mixture to the Light-Emitting Element) In this step, the mixture 50 prepared by the step of preparing the mixture described above is applied onto the mounting substrate 20 so as to cover the plurality of light-emitting elements 4 as shown in FIG. 4B. When applying the mixture 50 onto the mounting substrate 20 or after applying it, it is preferable to vibrate the mounting substrate 20, for example, in the vertical direction and / or the horizontal direction, whereby the mixture 50 can be uniformly applied.

[0070] Also, before applying the mixture 50, a protective film may be formed on the electrode 3 and / or the wiring electrodes of the mounting substrate 20, thereby suppressing the electrode 3 and / or the wiring electrodes of the mounting substrate 20 from being damaged, such as corrosion, by the alkaline solution contained in the mixture 50. Further, by forming a protective film on the electrode 3 and / or the wiring electrodes of the mounting substrate 20, it is possible to suppress damage caused by corrosive gases in the atmosphere or the like while the manufactured light-emitting device 1 is in use. That is, the gas barrier property of the light-emitting device 1 can be improved. The above-mentioned protective film can be formed using the atomic layer deposition (ALD) method.

[0071] Also, after the mixture 50 is disposed on the mounting substrate 20, for example, the mixture disposed on the mounting substrate 20 can be pressed using a glass plate to form the upper surface of the mixture 50 into a flat shape.

[0072] Also, before applying the mixture 50, a film of silicon oxide or aluminum oxide may be formed on the mounting substrate 20, thereby improving the adhesion between the mounting substrate 20 and the mixture 50.

[0073] Next, the mixture 50 is cured by the step of forming the above-described light-reflective member to form the light-reflective member 5.

[0074] (Step of exposing the light-transmissive member) Next, as shown in FIG. 4C, the light-reflective member 5 covering the upper surface 6a of the light-transmissive member 6 is removed, for example, by grinding to expose the upper surface 6a of the light-transmissive member 6. At this time, the exposed upper surface 6a of the light-transmissive member 6 becomes the light-emitting surface 1a of the light-emitting device 1. In this way, an intermediate body is formed including the mounting substrate 20, the plurality of light-emitting elements 4, the plurality of light-transmissive members 6 respectively disposed on the upper surfaces 4a of the respective light-emitting elements 4, and the light-reflective member 5.

[0075] (Dicing step) Next, the light-reflective member 5 is cut along a predetermined cutting position CL so as to include one light-emitting element 4, and the intermediate body is fragmented to obtain the light-emitting device 1. The fragmentation is carried out using, for example, a blade.

[0076] In the first manufacturing method, in the step of applying the mixture, the mixture 50 is applied covering the upper surface 6a of the light-transmissive member 6, and the upper surface 6a of the light-transmissive member 6 is exposed in the subsequent step of exposing the light-transmissive member. However, in the step of applying the mixture, the mixture 50 may be disposed on the mounting substrate 20 with the upper surface 6a of the light-transmissive member 6 exposed. Thereby, the step of exposing the light-transmissive member can be omitted.

[0077] Thus, it is desirable to form a groove 90 in the mixture 50 as shown in FIG. 5 after the step of applying the mixture and before the heating step. The groove 90 is desirably arranged along the cutting position CL in the fragmentation step. Also, it is desirable that the covering member is divided by the formation of the groove 90. Thereby, since the contraction stress generated during curing is directed from the location where the groove 90 is formed toward the light-emitting element 4 side, it is possible to prevent the light-emitting element 4 and the mixture 50 from peeling off during curing. As a result, the adhesion strength between the light-reflective member 5 formed by curing the mixture 50 and the light-emitting element 4 can be increased. The formation of the groove 90 is carried out using, for example, a blade. When forming the groove 90 before the heating step, in the step of applying the mixture 50 before that, it is preferable to expose the upper surface 6a of the light-transmissive member 6 and apply the mixture 50 because it is easy to maintain the shape of the groove 90 formed in the mixture 50.

[0078] It has been described above that in the fragmentation step, fragmentation is carried out such that one light-emitting device includes one light-emitting element. However, it is not limited to this, and fragmentation can also be carried out such that one light-emitting device includes two or more light-emitting elements. The same applies to the second manufacturing method described later.

[0079] <Second Manufacturing Method> Next, with reference to FIGS. 6A to 6D, another example of the manufacturing method of the light-emitting device 1 according to Embodiment 1 (Second manufacturing method) will be described.

[0080] (Step of preparing a light-transmissive member assembly) Here, as shown in FIG. 6A, a light-transmissive member assembly supported by a mixture 50 with the upper and lower surfaces of a plurality of light-transmissive members 6 exposed is prepared. The light-transmissive member assembly is prepared, for example, as follows. First, a plurality of light-transmissive members 6 are prepared, and a mixture 50 is prepared in the same manner as in the first manufacturing method. Next, the prepared mixture 50 is formed in a layer on, for example, a support substrate, and a plurality of through-holes for arranging the light-transmissive members 6 are provided in the layered mixture 50, and the light-transmissive members 6 are respectively arranged in the through-holes. Then, the support substrate is removed to prepare a light-transmissive member assembly supported by the mixture 50 with the upper and lower surfaces of the plurality of light-transmissive members 6 shown in FIG. 6A exposed. The obtained light-transmissive member assembly can support the light-transmissive members 6 by the thixotropy of the mixture 50 containing the above-described materials.

[0081] (Step of mounting a light-emitting element on a light-transmissive member) Next, as shown in FIG. 6B, a plurality of light-emitting elements 4 are respectively mounted on the light-transmissive members 6. Here, the surface of the light-emitting element 4 opposite to the surface on which the electrode 3 is formed is defined as the upper surface 4a. Also, the surface of the light-transmissive member 6 opposite to the surface on the light-emitting element side is defined as the upper surface 6a. The light-emitting element 4 will be mounted on the lower surface of the light-transmissive member 6.

[0082] (Step of applying a mixture to a light-emitting element) Next, as shown in FIG. 6C, the mixture 50 is applied onto the light-transmissive member assembly so as to cover the light-emitting elements 4. When applying this, it is desirable to vibrate the mixture 50 in the same manner as in the first manufacturing method. Also, in the same manner as in the first manufacturing method, in this manufacturing method, a protective film may be disposed on the surface of the electrode 3 using atomic layer volume method before and / or after applying the mixture 50.

[0083] (Step of forming a light-reflective member) Next, in the same manner as in the first manufacturing method, the mixture 50 is heated and cured to form the light-reflective member 5.

[0084] (Step of exposing the electrode) Next, as shown in FIG. 6D, the cured light-reflective member 5 is ground to expose the lower surface 3a of the electrode 3 of the light-emitting element 4. Here, the surface of the electrode 3 opposite to the surface on the light-emitting element 4 side is defined as the lower surface 3a. In this way, an intermediate body is formed including a plurality of light-emitting elements 4, a plurality of light-transmissive members 6 respectively disposed on the upper surfaces 4a of the respective light-emitting elements 4, and the light-reflective member 5.

[0085] (Step of singulation) Next, the light-reflective member 5 is cut along a predetermined cutting position CL so as to include one light-emitting element 4, and the intermediate body is singulated to obtain the light-emitting device 1. Singulation is performed, for example, using a blade.

[0086] Hereinafter, a method for manufacturing the light-emitting device 100 according to Embodiment 2 will be described. In the following description, the steps of preparing the light-emitting element, preparing the mixture, preparing the mixture, and forming the light-reflective member by heating and curing the mixture are the same as those described above, and the description of these steps will be omitted or simplified.

[0087] (Step of preparing the substrate) A substrate 35 having a bottom portion 32 and a wall portion 33 that define a recess is prepared. When the base material 30 of the substrate 35 is formed of a resin material, the bottom portion 32 and the wall portion 33 can be integrally formed, for example, by injection molding or the like. When the base material 30 of the substrate 35 is formed of a ceramic material, it can be manufactured by either a so-called post-fire method or a co-fire method. Even when the base material 30 of the substrate 35 is formed of either a resin material or a ceramic material, the bottom portion 32 and the wall portion 33 can be formed separately and then joined using an adhesive or the like.

[0088] (Step of disposing the light-emitting element) The light-emitting element 4 including the growth substrate 7 and the semiconductor laminate 2 is disposed on the bottom 32 of the substrate 35 within the recess 31. The light-emitting element 4 is mounted by connecting the electrode 3 to the wiring layer 41 via soldering or the like.

[0089] Prepare a mixture in the same manner as in the first manufacturing method. Here, in this manufacturing method, by adjusting the fluidity (viscosity) of the mixture, an inclined region R1 in which the surface is inclined at a desired angle or curved into a desired shape from the wall portion 33 toward the light-emitting element 4 can be formed in the step of disposing the mixture. The fluidity (viscosity) of the mixture can be adjusted, for example, by adding and mixing a volatile solvent.

[0090] (Step of disposing the mixture) Dispose the mixture on the bottom 32 of the substrate 35 within the recess 31. The mixture is disposed at a distance from the side surface 2a of the semiconductor laminate 2. The mixture is disposed so as to include a region where the height decreases from the wall portion 33 toward the light-emitting element 4. The mixture is disposed, for example, by coating with a dispenser. The mixture is, for example, simultaneously coated on the wall portion 33 and the bottom 32, or coated on the inner surface 33a of the wall portion 33. Thereby, an inclined region can be formed. Also, by simultaneously coating the mixture on the wall portion 33 and the bottom 32, or coating the mixture on the inner surface 33a of the wall portion 33, the mixture can be disposed at a position away from the light-emitting element 4, and it is possible to suppress the side surface 2a of the semiconductor laminate 2 from being covered with the mixture.

[0091] (Step of heating the mixture to form a light-reflective member / Heating step) In the same manner as in the first manufacturing method, the mixture is heated and cured to form the light-reflective member 55.

[0092] As described above, the light-emitting device 100 according to Embodiment 2 can be formed. Note that the step of arranging the light-emitting element may be before the step of arranging the mixture, or may be after the step of heating the mixture to form the light-reflective member. Further, the light-emitting devices 100 may be manufactured individually, or may be obtained by forming a plurality of them integrally and then separating them into individual pieces. Specifically, a collective substrate including a bottom surface and a plurality of walls is prepared, a light-emitting element and a mixture are arranged in each of a plurality of recesses formed by the bottom surface and the plurality of walls, the mixture is heat-cured, and they are separated into individual light-emitting devices.

[0093] Examples and Comparative Examples Examples and comparative examples will be described below. In Comparative Example 1 and Examples 1 to 3, the light-emitting device 1 of Embodiment 1 was used to form a light-reflective member by changing the composition of the mixture when forming the light-reflective member, and the thermal resistance Rj-a of each light-reflective member was measured. Table 1 shows the raw materials of the mixture for forming the light-reflective member, the ratio of the raw materials, and the thermal resistance Rj-a of the formed light-reflective member in Comparative Example 1 and Examples 1 to 3.

[0094]

Table 1

[0095] Here, the average particle size of the silicon dioxide (SiO2) used as the raw material is the median diameter, which is 0.4 μm, the average particle size of the powder of the light-reflective material made of boron nitride (BN) that also functions as an aggregate is 10 μm, and the average aspect ratio is 20. The average particle size of the powder of the light-reflective material made of titanium dioxide (TiO2) that also functions as a light-scattering material is 2.5 μm. The average particle size of the calcium oxide (CaO) used as the raw material is 15 μm. The mixture was cured by heating the mixture 50 at 90 °C under a pressure of 1 MPa for 0.5 hours for pre-curing, and then heating at 200 °C under a pressure of 1 MPa for 1 hour to be cured. Further, for each of the light-emitting devices in which the light-reflective members of Reference Example 1 and Examples 1 to 3 were formed, transient thermal resistance measurement using the heating method (dynamic method) was performed, and the measured thermal resistance values were compared and evaluated.

[0096] As shown in Table 1, it was confirmed that the thermal resistance could be lowered by including calcium oxide (CaO) in the mixture.

[0097] Next, based on Example 3, Reference Examples 2 and 3 in which the content ratios of boron nitride and calcium oxide in the mixture were changed were prepared, and the cured light-reflective members were evaluated. Table 2 shows the ratio of the mixed powder in the mixture. The ratios of the mixed powder and potassium hydroxide in Reference Examples 2 and 3 are the same as those in Example 3, and potassium hydroxide is not described in Table 2. Also, Example 3 is described in Table 2.

[0098]

Table 2

[0099] Here, CaO (wt%) shown in Table 2 indicates the content rate of the alkaline earth oxide containing CaO with respect to the mixture. As shown in Table 2, no cracks were confirmed in the cured light-reflective member in Example 3, whereas cracks were confirmed in the cured light-reflective members in Reference Examples 2 and 3. Thus, it is not preferable if the content rate of the alkaline earth oxide with respect to the mixture becomes too large. Therefore, the content rate of the alkaline earth oxide with respect to the mixture is preferably adjusted to, for example, 6.6 wt% or less.

[0100] Note that the embodiments disclosed this time are illustrative in all respects and are not a basis for limiting interpretation.

[0101] The light-emitting device and the method for manufacturing the light-emitting device of the present disclosure include the following aspects. [Item 1] A light-emitting element, A light-reflective member that includes an inorganic member and reflects light emitted from the light-emitting element, having, wherein the inorganic member, contains silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal, A light-emitting device. [Item 2] The light-emitting device according to Item 1, wherein the alkali metal includes potassium or sodium. [Item 3] The light-emitting device according to Item 1 or 2, wherein the alkaline earth metal includes any one of calcium, magnesium, and beryllium. [Item 4] The light-emitting device according to any one of Items 1 to 3, wherein the alkali metal includes potassium. [Item 5] The light-emitting device according to any one of Items 1 to 4, wherein the alkaline earth metal includes calcium. [Item 6] The light-emitting device according to any one of Items 1 to 5, wherein the light-reflective member further has a light-reflective material including at least one of boron nitride, titanium oxide, zirconium oxide, and aluminum oxide. [Item 7] The light-emitting device according to Item 6, wherein the light-reflective material includes boron nitride. [Item 8] The light-emitting device according to any one of Items 1 to 7, wherein the light-reflective member has a content rate of the hydroxide containing the alkaline earth metal of 0.1% by weight or more and 8.7% by weight or less. [Item 9] The light-emitting device according to any one of Items 1 to 7, wherein the light-reflective member has an open porosity of 20% or more and 40% or less. [Item 10] An inorganic member including silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal. [Item 11] An inorganic member including silicon oxide, an alkali metal, an oxide containing an alkaline earth metal, and water. [Item 12] A step of preparing a light-emitting element including a semiconductor structure, A step of preparing a mixture by mixing silicon oxide powder, an oxide containing an alkaline earth metal, and an alkaline solution containing an alkali metal; A step of applying the mixture to an area irradiated with light from the light-emitting element; A method for manufacturing a light-emitting device, comprising a step of forming a light-reflective member by curing the mixture by heating. [Item 13] The method for manufacturing a light-emitting device according to claim 12, wherein in the step of preparing the mixture, the content of the oxide containing the alkaline earth metal in the mixture is 0.1% by weight or more and 6.6% by weight or less.

Explanation of reference numerals

[0102] 1, 100, 100A Light-emitting device 1a, 100a Light-emitting surface 2 Semiconductor laminate 2a Side surface 3 Electrode 3a Bottom surface 4 Light-emitting element 4a Top surface 5, 55 Light-reflective member 6 Translucent member 6a Top surface 7 Growth substrate 11 Hydroxide 12 Support member 13 Light-reflective material 14 Void 15 Inorganic member 30 Base material 31 Recess 32 Bottom 32a Top surface 32b Bottom surface 33 Wall portion 33a Inner surface 35 Substrate 40 Conductive member 41 Wiring layer 42 External electrode 43 Identification mark 44 Wiring layer on the anode side 45 Wiring layer on the cathode side 50 Mixture 80 Protection element 81 Conductive wire 90 Groove P1 End

Claims

1. A light-emitting element, an inorganic member, and a light-reflective member that includes the inorganic member and reflects light emitted from the light-emitting element, wherein the light-reflective member has, the inorganic member includes, silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal, a light-emitting device.

2. The light-emitting device according to claim 1, wherein the alkali metal includes potassium or sodium.

3. The light-emitting device according to claim 1, wherein the alkaline earth metal includes any one of calcium, magnesium, and beryllium.

4. The light-emitting device according to claim 1, wherein the alkali metal includes potassium.

5. The light-emitting device according to claim 1, wherein the alkaline earth metal includes calcium.

6. The light-emitting device according to any one of claims 1 to 5, wherein the light-reflective member further has a light-reflective material including at least one of boron nitride, titanium oxide, zirconium oxide, and aluminum oxide.

7. The light-emitting device according to claim 6, wherein the light-reflective material includes boron nitride.

8. The light-emitting device according to claim 1, wherein the light-reflective member has a content of the hydroxide containing the alkaline earth metal of 0.1% by weight or more and 8.7% by weight or less.

9. The light-emitting device according to claim 1, wherein the light-reflective member has an open porosity of 20% or more and 40% or less.

10. An inorganic member including silicon oxide, an alkali metal, and a hydroxide containing an alkaline earth metal.

11. An inorganic member including silicon oxide, an alkali metal, an oxide containing an alkaline earth metal, and water.

12. A step of preparing a light-emitting element including a semiconductor structure, a step of mixing a powder of silicon oxide, an oxide containing an alkaline earth metal, and an alkaline solution containing an alkali metal to prepare a mixture, a step of applying the mixture to a region where light from the light-emitting element is reflected, a step of forming a light-reflective member by curing the mixture by heating, a method for manufacturing a light-emitting device.

13. The method for manufacturing a light-emitting device according to claim 12, wherein in the step of preparing the mixture, the mixture has a content of the oxide containing the alkaline earth metal of 0.1% by weight or more and 6.6% by weight or less.

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