Light emitting device

Abstract

A light emitting device (1) includes a plurality of light emitting elements (10) arranged at a predetermined interval, a first phosphor layer (20) made of a phosphor ceramic, and a filling member (30, 30A) covering side surfaces of the plurality of light emitting elements (10) and provided between adjacent light emitting elements (10). The first phosphor layer (20) is a single plate-shaped member covering light exit surfaces of the plurality of light emitting elements (10), and the first phosphor layer (20) is arranged in abutment with the plurality of light emitting elements (10) and the filling member (30, 30A).

Description

Technical Field

[0001] This disclosure relates to light-emitting devices. Background Technology

[0002] In recent years, light-emitting devices that combine light-emitting elements such as light-emitting diodes (LEDs) or laser diodes (LDs) with phosphors have become increasingly popular. Such devices are used as light sources in image display devices such as monitors and projectors, as well as in lighting devices.

[0003] Patent Document 1 discloses a light-emitting device comprising a light-emitting diode and a phosphor layer containing a phosphor. Specifically, the light-emitting device comprises: a light-emitting diode electrically bonded to a circuit board; a housing surrounding the light-emitting diode; and a component for the light-emitting device having a sealing resin layer capable of sealing the light-emitting diode and a phosphor layer formed on the surface of the sealing resin layer.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2012-28666 Summary of the Invention

[0005] In this light-emitting device that combines a light-emitting element and a phosphor, the temperature of the phosphor layer rises due to the heat emitted from the phosphor, which may result in a decrease in luminous intensity over time (temperature quenching). Therefore, heat dissipation of the phosphor layer is necessary to suppress temperature quenching. However, in Patent Document 1, due to the presence of a sealing resin layer with low thermal conductivity between the phosphor layer and the light-emitting diode, heat dissipation of the phosphor layer is insufficient, making it difficult to suppress the temperature quenching of the phosphor.

[0006] This disclosure was made in view of the problems inherent in the prior art. Furthermore, the object of this disclosure is to provide a light-emitting device capable of efficiently dissipating heat from the phosphor layer.

[0007] To address the aforementioned issues, the light-emitting device of this disclosure comprises: a plurality of light-emitting elements arranged at predetermined intervals; a first phosphor layer made of phosphor ceramic; and a filling member covering the sides of the plurality of light-emitting elements and disposed between adjacent light-emitting elements. The first phosphor layer is a plate-shaped member covering the light-emitting surfaces of the plurality of light-emitting elements, and the first phosphor layer is arranged in a manner that abuts against the plurality of light-emitting elements and the filling member. Attached Figure Description

[0008] [ Figure 1A ] Figure 1A This is a cross-sectional view showing an example of the light-emitting device according to the first embodiment.

[0009] [ Figure 1B ] Figure 1B It indicates looking down. Figure 1A A top view of the state of the light-emitting device.

[0010] [ Figure 1C ] Figure 1C It means in Figure 1B A top view of the light-emitting device in which the first phosphor layer has been removed.

[0011] [ Figure 2A ] Figure 2A This is a cross-sectional view used to illustrate the heat dissipation path in the light-emitting device of the first embodiment.

[0012] [ Figure 2B ] Figure 2B This is a top view used to illustrate the heat dissipation path in the light-emitting device of the first embodiment.

[0013] [ Figure 3A ] Figure 3A This is a cross-sectional view showing an example of the light-emitting device according to the second embodiment.

[0014] [ Figure 3B ] Figure 3B It indicates looking down. Figure 3A A top view of the state of the light-emitting device.

[0015] [ Figure 4 ] Figure 4 This is a cross-sectional view showing another example of the light-emitting device according to the second embodiment.

[0016] [ Figure 5 ] Figure 5 This is a cross-sectional view showing an example of the light-emitting device according to the third embodiment.

[0017] [ Figure 6 ] Figure 6 This is a diagram showing the result of the light beam profile in the light-emitting device of Embodiment 1-1.

[0018] [ Figure 7 ] Figure 7 This is a diagram showing the result of the light beam profile in the light-emitting device of Embodiments 1-2.

[0019] [ Figure 8 ] Figure 8 This is a front view showing the overall shape of the analytical model used in the CAE analysis of Example 2.

[0020] [ Figure 9 ] Figure 9 This is a 3D diagram showing the light-emitting module in the analytical model used in CAE analysis.

[0021] [ Figure 10A ] Figure 10AThis is a top view showing the light-emitting module in the analytical model used in CAE analysis.

[0022] [ Figure 10B ] Figure 10B This is a front view showing the light-emitting module in the analytical model used in CAE analysis.

[0023] [ Figure 11 ] Figure 11 This is a schematic diagram showing the light-emitting device in the analytical model used in CAE analysis.

[0024] [ Figure 12 ] Figure 12 This is a top view of the light-emitting device in the analytical model used in CAE analysis, used to illustrate the configuration of the light-emitting elements and dam materials.

[0025] [ Figure 13 ] Figure 13 This is a top view of the luminescent device in the analytical model used in CAE analysis, illustrating the configuration of the phosphor layer, filling components, and dam material.

[0026] [ Figure 14 ] Figure 14 This is a table showing the structure of the light-emitting devices of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3 and the results of CAE analysis.

[0027] [ Figure 15 ] Figure 15 The above is a contour map showing the temperature distribution on the surface of the light-emitting surface of the first phosphor layer in the CAE analysis of the light-emitting devices of Example 2-1, Comparative Example 2-1 and Comparative Example 2-3.

[0028] [ Figure 16 ] Figure 16 It is along Figure 15 The dashed line in the graph shows the relationship between the diagonal distance of the first phosphor layer and the surface temperature of the first phosphor layer.

[0029] [ Figure 17 ] Figure 17 This is a contour map showing the temperature distribution on the light-emitting surface of the first phosphor layer and the temperature distribution on the light-emitting surface of the second phosphor layer in CAE analysis of the light-emitting devices of Examples 2-2, 2-3 and Comparative Example 2-2.

[0030] [ Figure 18 ] Figure 18 It is along Figure 17 The dashed line in the graph shows the relationship between the diagonal distance of the first phosphor layer and the surface temperature of the first phosphor layer.

[0031] [ Figure 19 ] Figure 19 It is along Figure 17 The dashed line in the graph shows the relationship between the diagonal distance of the second phosphor layer and the surface temperature of the second phosphor layer. Detailed Implementation

[0032] The light-emitting device of this embodiment will now be described in detail using the accompanying drawings. Furthermore, for ease of explanation, the scale of the drawings has been exaggerated and may sometimes differ from the actual scale.

[0033] [First Implementation Method] like Figure 1A and Figure 1B As shown, the light-emitting device 1 of this embodiment includes a plurality of light-emitting elements 10, a first phosphor layer 20 made of phosphor ceramic, and a filling member 30 covering the sides of the plurality of light-emitting elements 10.

[0034] Multiple light-emitting elements 10 are mounted on the main surface 41 of a flat substrate 40. Metal wiring for supplying power to the light-emitting elements 10 and electrodes for supplying power to the light-emitting elements 10 from external devices are provided on the substrate 40. The material constituting the substrate 40 is not particularly limited; the substrate 40 may be a ceramic substrate, a resin substrate, a glass substrate, or a metal substrate with an electrically insulating film coated on a metal plate.

[0035] A white substrate with high light reflectivity can also be used as substrate 40. By using a white substrate, the light emitted by the light-emitting element 10 can be reflected on the surface of substrate 40, thereby improving light extraction efficiency. A white ceramic substrate made of alumina can be used as such substrate 40. It should be noted that the shape of substrate 40 when viewed from above is not particularly limited, and can be as follows: Figure 1B The shape shown is rectangular, but it can also be circular or polygonal.

[0036] The multiple light-emitting elements 10 can be light-emitting diodes (LEDs) or laser diodes (LDs). In this embodiment, such as... Figure 1C As shown, four light-emitting elements 10 are mounted on the substrate 40, arranged in two rows in the X-axis direction and two rows in the Y-axis direction. Furthermore, adjacent light-emitting elements 10 are separated from each other and arranged with a predetermined interval. Moreover, as described later, a filler member 30 is provided between adjacent light-emitting elements 10.

[0037] The light-emitting element 10 is a light-emitting surface that emits excitation light from its upper surface 11. Multiple light-emitting elements 10 are electrically connected in a manner that allows them to light up and turn off simultaneously. Specifically, adjacent light-emitting elements 10 are connected in a chip-to-chip manner via power supply bonding wires. Furthermore, the number of light-emitting elements 10 is... Figure 1C There are four in the middle, but there is no special restriction as long as there are multiple.

[0038] The wavelength of the excitation light emitted by the light-emitting element 10 is not particularly limited, but the peak wavelength of the excitation light can be set to 430 nm or more and 460 nm or less, or 445 nm or more and 460 nm or less. By setting the peak wavelength of the excitation light to 430 nm or more, the color rendering of the light emitted by the light-emitting device 1 can be improved. In addition, by setting the peak wavelength of the excitation light to 460 nm or less, the luminous efficiency of the light-emitting device 1 can be improved. Furthermore, the excitation light emitted by the light-emitting element 10 is not limited to blue light, but can also be ultraviolet light, green light, or red light. In addition, multiple light-emitting elements 10 can be combined to emit ultraviolet or green light and blue light, or to emit blue light and red light.

[0039] The first phosphor layer 20 is composed of phosphor ceramic formed by sintering phosphors. The phosphor ceramic is composed only of inorganic materials with excellent thermal conductivity, thus it can dissipate the heat emitted by the phosphor in the phosphor ceramic, suppress the temperature quenching of the phosphor, and achieve high output of light emission.

[0040] Here, for example, (Ga,Sc)₂O₃:Cr 3+ The thermal conductivity of phosphor ceramics, formed by sintering phosphors, is approximately 8.6 W / m·K. This is achieved by combining Gd3Ga2(GaO4)3:Cr... 3+ The thermal conductivity of phosphor ceramics formed by sintering phosphors is approximately 6.5 W / m·K. Additionally, Y3Al5O... 12 Ce 3+ The thermal conductivity of phosphor ceramics, sintered from phosphors, is approximately 10 W / m·K. In contrast, the thermal conductivity of wavelength conversion components, which disperse phosphor particles within transparent materials such as silicone resin, is approximately 0.2 W / m·K. Thus, phosphor ceramics exhibit better thermal conductivity than the aforementioned wavelength conversion components, enabling efficient dissipation of heat emitted from the phosphor.

[0041] The phosphor included in the first phosphor layer 20 is an inorganic phosphor that absorbs excitation light emitted from the light-emitting element 10 and emits fluorescence with a wavelength longer than the excitation light. At least one of blue, green, yellow, and red phosphors can be used as such a phosphor.

[0042] Blue phosphors exhibit emission peaks in the wavelength region of 470 nm to 500 nm, green phosphors in the wavelength region of 500 nm to 540 nm, and yellow phosphors in the wavelength region of 545 nm to 595 nm. Examples of blue phosphors include BaMgAl. 10 O 17 Eu 2+CaMgSi2O6:Eu 2+ Ba3MgSi2O8:Eu 2+ 、Sr 10 (PO4)6Cl2:Eu 2+ Examples of green phosphors include (Ba,Sr)₂SiO₄:Eu. 2+ Ca8Mg(SiO4)4Cl2:Eu 2+ Ca8Mg(SiO4)4Cl2:Eu 2 + Mn 2+ Examples of yellow phosphors include (Sr,Ba)₂SiO₄:Eu 2+ (Y, Gd)3Al5O 12 Ce 3+ Ca-α-SiAlON:Eu 2+ .

[0043] The red phosphor is excited by the emitted light from the light source 10 or at least one of the green and yellow phosphors, emitting red light. The red phosphor has an emission peak in the wavelength region of 600 nm to 650 nm. Examples of red phosphors include Sr₂Si₅N₈:Eu 2+ CaAlSiN3:Eu 2+ (CASN), SrAlSi4N7:Eu 2+ CaS: Eu 2+ La2O2S: Eu 3+ , Y3Mg2 (AlO4) (SiO4) 2: Ce 3+ .

[0044] Alternatively, the phosphor included in the first phosphor layer 20 can also be a near-infrared phosphor. For example, inorganic phosphors with fluorescence peaks in the wavelength range of 750 nm to less than 1500 nm, particularly 780 nm to less than 900 nm, can be used as near-infrared phosphors. Representative examples of such near-infrared phosphors include phosphors activated by transition metal ions and phosphors activated by rare earth ions. Specifically, the near-infrared phosphor can be Cr... 3+ At least one of activated phosphors and rare-earth activated phosphors. Rare-earth activated phosphors may be selected from Tm... 3+ Er 3+ 、Nd 3+ and Yb 3+ At least one activated phosphor.

[0045] In near-infrared phosphors, the preferred fluorescent ion is Cr. 3+ By using Cr 3+As fluorescent ions, near-infrared phosphors readily absorb blue light and convert it into near-infrared light components. Furthermore, depending on the parent ion, the wavelengths of the light absorption peak and / or fluorescence peak can be easily altered, which is beneficial for changing the shape of the excitation and fluorescence spectra.

[0046] Near-infrared phosphors are preferably composed of Cr 3+ A phosphor composed of activated metal composite oxides. Specifically, the near-infrared phosphor is preferably based on at least one of borates, phosphates, silicates, aluminates, gallates, germanates, tungstates, and metal oxides, and is composed of Cr. 3+ Activated phosphors. Such near-infrared phosphors can be selected from CeSc3(BO3)4:Cr 3+ , (La, Y, Sc) 4 (BO3) 4: Cr 3+ LaSc3(BO3)4:Cr 3+ ScBO3:Cr 3+ KInP2O7:Cr 3+ Sr3InP3O 12 Cr 3+ Sr9In(PO4)7:Cr 3+ NaScSi2O6:Cr 3+ Mg2Al4Si5O 18 Cr 3+ La3(Ga,Gd)5GeO 14 Cr 3 + La3(Ga,Al)5SiO 14 Cr 3+ ,LaMgGa 11 O 19 Cr 3+ Mg3Ga2GeO8:Cr 3+ Li(In,Sc)Ge2O6:Cr 3+ Zn3(Ga,Al)Ge2O 10 Cr 3+ LiMg2InGe2O8:Cr 3+ NaCa2GaGe5O 14 Cr 3+ NaGdMgWO6:Cr 3+ (Ga,Sc)₂O₃:Cr 3+ LaLuO3:Cr 3+ Ba3Sc4O9:Cr 3+ Zn2SnO4:Cr 3+ LiIn2SbO6:Cr 3+LiSrAlF6:Cr 3+ At least one of them.

[0047] Near-infrared phosphors are preferably phosphors with a garnet-type crystal structure that have a large number of practical applications. Furthermore, phosphors with a chromium-based crystal structure are preferred. 3+ Activated garnet-type crystalline phosphors, for example, those composed of RE3B'2(AlO4)3:Cr 3+ RE3B'2(GaO4)3:Cr 3+ The general formula is used to represent it. It should be noted that RE represents rare earth elements, and B' is at least one element selected from Al, Ga, and Sc.

[0048] As a near-infrared phosphor, it is preferably at least one of rare-earth aluminum garnet phosphor and rare-earth gallium garnet phosphor. Specifically, the near-infrared phosphor is preferably selected from Y3Al2(AlO4)3:Cr 3+ La3Al2(AlO4)3:Cr 3+ Gd3Al2(AlO4)3:Cr 3+ Y3Ga2(AlO4)3:Cr 3+ La3Ga2(AlO4)3:Cr 3+ Gd3Ga2(AlO4)3:Cr 3+ Y3Sc2(AlO4)3:Cr 3+ La3Sc2(AlO4)3:Cr 3+ Gd3Sc2(AlO4)3:Cr 3+ Y3Ga2(GaO4)3:Cr 3+ La3Ga2(GaO4)3:Cr 3 + Gd3Ga2(GaO4)3:Cr 3+ Y3Sc2(GaO4)3:Cr 3+ La3Sc2(GaO4)3:Cr 3+ Gd3Sc2(GaO4)3:Cr 3+ At least one of them.

[0049] like Figure 1A and Figure 1C As shown, the filling member 30 is formed on the main surface 41 of the substrate 40 to cover the periphery of the plurality of light-emitting elements 10. Specifically, the filling member 30 is arranged to contact and cover the periphery of each light-emitting element 10 when viewed from above. In addition, the filling member 30 is provided to fill the gaps between adjacent light-emitting elements 10.

[0050] The filling member 30 can be formed of any thermally conductive material, and the material is not particularly limited. Furthermore, the filling member 30 preferably contains a reflective material that reflects light. By including a reflective material in the filling member 30, the excitation light emitted from the light-emitting element 10 and the fluorescence emitted from the phosphor are reflected, thereby improving the luminous efficiency of the light-emitting device 1.

[0051] As the filler component 30, a curable white silicone resin can be used, for example. The curable white silicone resin is a resin in which a white pigment is dispersed in a silicone resin. As the white pigment, at least one selected from rare earth oxides such as titanium dioxide, alumina, and yttrium oxide, zinc sulfate, zinc oxide, and magnesium oxide can be used. Furthermore, to improve the strength and thermal conductivity of the cured product, an inorganic filler material can be included in the curable white silicone resin. As the inorganic filler material, at least one selected from fused silica, crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, glass fiber, and antimony trioxide can be used.

[0052] like Figures 1A-1C As shown, a dam material 50 serving as a sidewall is provided on the outer periphery of the filling member 30 disposed around the plurality of light-emitting elements 10. The dam material 50 is erected from the main surface 41 of the substrate 40 toward the Z-axis direction and is formed into a rectangular shape in plan view so as to cover the entire outer periphery of the filling member 30. By providing the dam material 50 on the entire outer periphery of the filling member 30, the filling member 30 can be stably held inside the dam material 50. Furthermore, as Figure 1A As shown, the height of the dam material 50 in the Z-axis direction can be higher than the stack of the filling member 30, the light-emitting element 10, and the first phosphor layer 20.

[0053] The material constituting the dam material 50 is not particularly limited and can be at least one selected from metals, resins, and ceramics. Furthermore, the dam material 50 preferably has light reflectivity, and therefore is more preferably composed of a light reflective material.

[0054] In the light-emitting device 1, a first phosphor layer 20 is stacked on the upper surface 11 of multiple light-emitting elements 10, and is a plate-shaped component covering the light-emitting surfaces of the multiple light-emitting elements 10. That is, as shown... Figure 1B As shown, the first phosphor layer 20 covers not only the light-emitting surfaces of the four light-emitting elements 10, but also the upper surface of the filling member 30A located between adjacent light-emitting elements 10. Furthermore, the first phosphor layer 20 can be directly laminated onto the upper surfaces 11 of the plurality of light-emitting elements 10, or it can be laminated via an adhesive layer. The adhesive layer used to bond the first phosphor layer 20 and the light-emitting elements 10 is not particularly limited; for example, at least one of a transparent inorganic adhesive and an organic adhesive can be used.

[0055] Furthermore, the first phosphor layer 20 abuts against the upper surface 31A of the filling member 30A located between the upper surfaces 11 of the plurality of light-emitting elements 10 and adjacent light-emitting elements 10. That is, the lower surface 21 of the first phosphor layer 20 can also directly contact the upper surfaces 11 of the plurality of light-emitting elements 10 and the upper surface 31A of the filling member 30A. In addition, when the first phosphor layer 20 is bonded to the plurality of light-emitting elements 10 by an adhesive layer, the first phosphor layer 20 can also contact the upper surface 31A of the filling member 30A located between the upper surfaces 11 of the plurality of light-emitting elements 10 and adjacent light-emitting elements 10 via the adhesive layer. In this way, the first phosphor layer 20 abuts against the upper surfaces 11 of the plurality of light-emitting elements 10 and the upper surface 31A of the filling member 30A, thereby dissipating heat generated by the first phosphor layer 20 to the light-emitting elements 10 and the filling member 30A, as described later.

[0056] In the light-emitting device 1, when viewed from above the light-emitting surface of the plurality of light-emitting elements 10, it is preferable that the external dimensions of the first phosphor layer 20 are approximately the same as the external dimensions of the plurality of light-emitting elements 10. Specifically, as follows: Figure 1B and Figure 1C As shown, the Y-axis dimension W1 of the first phosphor layer 20 is preferably approximately the same as the Y-axis dimension W3 of the two light-emitting elements 10 including the filling member 30A. Similarly, the X-axis dimension W2 of the first phosphor layer 20 is preferably approximately the same as the Y-axis dimension W4 of the two light-emitting elements 10 including the filling member 30A. By making the Y-axis dimension of the first phosphor layer 20 approximately the same as the Y-axis dimension of the plurality of light-emitting elements 10, the area of ​​the light-emitting surface of the light-emitting device 1 can be reduced. Therefore, the output light emitted from the light-emitting device 1 is less likely to diffuse, and thus the output light is easily captured by the lens disposed near the light-emitting device 1. As a result, the lens disposed near the light-emitting device 1 can be miniaturized. Furthermore, by miniaturizing the lens, the housing containing the lens and the light-emitting device 1 can also be miniaturized.

[0057] Furthermore, in this specification, "the external dimensions of the first phosphor layer 20 are substantially the same as the external dimensions of the plurality of light-emitting elements 10" means that the difference between the external dimensions of the plurality of light-emitting elements 10 and the external dimensions of the first phosphor layer 20 is ±10% or less. Specifically, this means that the difference between the external dimensions W1 of the first phosphor layer 20 and the external dimensions W3 of the light-emitting elements 10 is ±10%, and the difference between the external dimensions W2 of the first phosphor layer 20 and the external dimensions W4 of the light-emitting elements 10 is ±10%. Moreover, the difference between the external dimensions of the plurality of light-emitting elements 10 and the external dimensions of the first phosphor layer 20 is preferably ±5% or less.

[0058] The operation of the light-emitting device 1 of this embodiment, having such a configuration, will be explained. In the light-emitting device 1 of this embodiment, firstly, when power is applied to the light-emitting element 10, excitation light (primary light) is emitted upward from the light-emitting element 10. The emitted excitation light passes through the first phosphor layer 20, and at this time, a portion of the excitation light is absorbed by the fluorescent ions of the phosphor contained in the first phosphor layer 20. Then, the fluorescent ions are converted into fluorescence through electron energy transitions, and the fluorescence is emitted upward from the phosphor.

[0059] Here, when the wavelength is converted into fluorescence upon absorption of excitation light, the phosphors in the first phosphor layer 20 heat up. However, the phosphors that primarily heat up are those in the region where the excitation light is mainly irradiated. That is, the phosphors that primarily heat up are... Figure 2A and Figure 2B The phosphor in region 22, enclosed by a single-dotted line, specifically refers to the phosphor located directly above the light-emitting element 10. In contrast, in the first phosphor layer 20, there is no phosphor directly above the light-emitting element 10, i.e. Figure 2A and Figure 2B The phosphors in region 23, not enclosed by a single-dotted line, receive less excitation light, resulting in minimal or no heat generation. Therefore, as... Figure 2A and Figure 2B As shown by the arrow, heat conduction occurs from the region 22 with high heat generation to the region 23 with low heat generation.

[0060] The filler member 30A is located directly below the region 23 where heat generation is low, and the upper surface 31A of the filler member 30A abuts against the region 23. Therefore, the heat conducted to the region 23 is conducted from the region 23 to the filler member 30A, and then the heat conducted to the filler member 30A is conducted from the filler member 30A to the substrate 40.

[0061] Furthermore, as described above, the first phosphor layer 20 abuts against the upper surface 11 of the plurality of light-emitting elements 10. Therefore, as... Figure 2A As indicated by the arrow, the heat generated in region 22 of the first phosphor layer 20 is conducted from the first phosphor layer 20 to the light-emitting element 10 directly below it, and then the heat conducted to the light-emitting element 10 is conducted from the light-emitting element 10 to the substrate 40. In addition, the heat conducted to the substrate 40 is dissipated to the outside of the substrate 40.

[0062] Thus, in the light-emitting device 1 of this embodiment, the heat generated in region 22 of the first phosphor layer 20 is conducted to the relatively low-temperature region 23, and then from region 23 to the filling member 30A and then to the substrate 40. Simultaneously, the heat generated in region 22 of the first phosphor layer 20 is conducted to the light-emitting element 10, and then from the light-emitting element 10 to the substrate 40. Therefore, heat dissipation in region 22 of the first phosphor layer 20 is efficiently achieved, thereby suppressing temperature quenching of the phosphor contained in region 22.

[0063] Here, it is assumed that without the filling member 30A located between adjacent light-emitting elements 10, there is an air layer between adjacent light-emitting elements 10. However, the air layer has low thermal conductivity, making it difficult to dissipate the heat conducted to region 23. However, in the light-emitting device 1, since the filling member 30A is provided, the heat of region 23 can be conducted to the substrate 40 via the filling member 30A.

[0064] Furthermore, assuming that there is a gap between the light-emitting element 10 and the first phosphor layer 20, and the excitation light emitted from the light-emitting element 10 extends and irradiates the entire first phosphor layer 20, the entire first phosphor layer 20 will heat up, making it difficult to generate a relatively low-temperature region 23. Therefore, it may not be possible to adequately dissipate heat from the first phosphor layer 20. Thus, in order to generate a relatively low-temperature region 23, the first phosphor layer 20 also needs to be in contact with multiple light-emitting elements 10.

[0065] exist Figure 1A In the illustrated light-emitting device 1, the height of the filling member 30, which covers the entire periphery of the light-emitting element 10, is approximately the same as the height of the plurality of light-emitting elements 10. Therefore, the side surface of the first phosphor layer 20 is not in contact with the filling member 30. However, this embodiment is not limited to this configuration. For example, the height of the filling member 30 may be approximately the same as the height of the stack of the light-emitting element 10 and the first phosphor layer 20, so that the side surface of the first phosphor layer 20 is in contact with the filling member 30. In this way, the side surface of the first phosphor layer 20 is covered by the filling member 30, thereby allowing heat generated by the first phosphor layer 20 to be conducted to the filling member 30 for heat dissipation. Therefore, the heat dissipation performance of the first phosphor layer 20 can be further improved.

[0066] Furthermore, when viewed from above the light-emitting surface of the plurality of light-emitting elements 10, the external dimensions of the first phosphor layer 20 are approximately the same as those of the plurality of light-emitting elements 10. Therefore, the output light emitted from the light-emitting device 1 is difficult to diffuse, and thus the output light can easily enter the lens disposed near the light-emitting device 1, enabling the lens to be miniaturized.

[0067] [Second Implementation] Next, the light-emitting device of the second embodiment will be described in detail. Furthermore, the same reference numerals are used for components identical to those in the first embodiment, and repeated descriptions are omitted.

[0068] like Figure 3A and Figure 3B As shown, the light-emitting device 2 of this embodiment includes a plurality of light-emitting elements 10 arranged at predetermined intervals, a first phosphor layer 20, and a filling member 30.

[0069] Similar to the first embodiment, a plurality of light-emitting elements 10 are mounted on a flat substrate 40 and arranged in two rows in the X-axis direction and two rows in the Y-axis direction. Moreover, adjacent light-emitting elements 10 are separated from each other and arranged with a predetermined interval.

[0070] The first phosphor layer 20 is made of phosphor ceramic sintered from phosphor and is a plate-shaped component covering the light-emitting surfaces of multiple light-emitting elements 10. The filling member 30 is arranged to contact and cover the entire periphery of each light-emitting element 10. Furthermore, the filling member 30 is provided to fill the gaps between adjacent light-emitting elements 10. Additionally, a dam material 50 serving as a sidewall is provided on the outer periphery of the filling member 30 disposed around the multiple light-emitting elements 10.

[0071] In addition to covering the light-emitting surfaces of the four light-emitting elements 10, the first phosphor layer 20 also covers the upper surface of the filling member 30A located between adjacent light-emitting elements 10. Furthermore, the first phosphor layer 20 can be directly laminated onto the upper surface 11 of the multiple light-emitting elements 10, or it can be laminated via an adhesive layer.

[0072] In this embodiment, the light-emitting device 2 further includes a second phosphor layer 60 stacked on the first phosphor layer 20. As explained in the first embodiment, the heat dissipation of the first phosphor layer 20 is improved in the light-emitting device 2. Therefore, even though the second phosphor layer 60, which is a heat source, is stacked on the first phosphor layer 20, the temperature rise of the first phosphor layer 20 can be suppressed. Furthermore, by including a second phosphor layer 60 in addition to the first phosphor layer 20, a light-emitting device capable of emitting fluorescence of multiple wavelengths can be obtained.

[0073] The second phosphor layer 60 can be made of phosphor ceramic formed by sintering a phosphor, or it can be a wavelength conversion component in which phosphor particles are dispersed in a light-transmitting material such as silicone resin. However, the second phosphor layer 60 is preferably made of phosphor ceramic formed by sintering a phosphor. This allows for efficient heat dissipation from the phosphor in the second phosphor layer 60, suppressing the temperature quenching of the phosphor.

[0074] The phosphor contained in the second phosphor layer 60 is not particularly limited, and at least one of blue, green, yellow, red, and near-infrared phosphors can be used. Furthermore, the aforementioned substances can be used for blue, green, yellow, red, and near-infrared phosphors.

[0075] In the light-emitting device 2, the second phosphor layer 60 is stacked on the upper surface 24 of the first phosphor layer 20, and is a plate-like component covering the upper surface 24 of the first phosphor layer 20. Furthermore, the second phosphor layer 60 can be directly stacked on the upper surface 24 of the first phosphor layer 20, or it can be stacked via an adhesive layer. The adhesive layer used to bond the first phosphor layer 20 and the second phosphor layer 60 is not particularly limited; for example, at least one of a transparent inorganic adhesive and an organic adhesive can be used.

[0076] In the light-emitting device 2, when viewed from above the light-emitting surface of the plurality of light-emitting elements 10, it is preferable that the external dimensions of the second phosphor layer 60 are approximately the same as those of the first phosphor layer 20. Specifically, as follows: Figure 3B As shown, the Y-axis dimension W1 of the first phosphor layer 20 is preferably approximately the same as the Y-axis dimension W5 of the second phosphor layer 60. Similarly, the X-axis dimension W2 of the first phosphor layer 20 is preferably approximately the same as the Y-axis dimension W6 of the second phosphor layer 60. By making the dimensions of the first phosphor layer 20 and the second phosphor layer 60 approximately the same, the area of ​​the light-emitting surface of the light-emitting device 2 can be reduced. Therefore, the output light emitted from the light-emitting device 2 is less likely to diffuse, and thus the output light is easily captured by the lens disposed near the light-emitting device 2. As a result, the lens disposed near the light-emitting device 2 can be miniaturized. Furthermore, by miniaturizing the lens, the housing containing both the lens and the light-emitting device 2 can also be miniaturized.

[0077] Furthermore, in this specification, "the external dimensions of the second phosphor layer 60 are approximately the same as the external dimensions of the first phosphor layer 20" means that the difference between the external dimensions of the first phosphor layer 20 and the external dimensions of the second phosphor layer 60 is ±10% or less. Specifically, this means that the difference between the external dimensions W5 of the second phosphor layer 60 and the external dimensions W1 of the first phosphor layer 20 is ±10%, and the difference between the external dimensions W6 of the second phosphor layer 60 and the external dimensions W2 of the first phosphor layer 20 is ±10%. Additionally, the difference between the external dimensions of the first phosphor layer 20 and the external dimensions of the second phosphor layer 60 is preferably ±5% or less.

[0078] The operation of the light-emitting device 2 of this embodiment, having such a configuration, will be explained. In the light-emitting device 2 of this embodiment, firstly, when power is applied to the light-emitting element 10, excitation light (primary light) is emitted upward from the light-emitting element 10. The emitted excitation light passes through the first phosphor layer 20 and the second phosphor layer 60, at which time a portion of the excitation light is absorbed by the fluorescent ions of the phosphor contained in the first phosphor layer 20. Similarly, a portion of the excitation light is absorbed by the fluorescent ions of the phosphor contained in the second phosphor layer 60. Then, the fluorescent ions are converted into fluorescence through electron energy transitions, and the fluorescence is emitted upward from the phosphor. Furthermore, in the light-emitting device 2, the phosphor in the second phosphor layer 60 may also absorb the fluorescence emitted from the phosphor in the first phosphor layer 20 and emit fluorescence of a longer wavelength.

[0079] Here, when the wavelength is converted into fluorescence upon absorption of excitation light, the phosphors in the first phosphor layer 20 and the second phosphor layer 60 heat up. However, the phosphors that primarily heat up are those in the region where the excitation light is mainly irradiated. That is, the phosphors that primarily heat up are... Figure 3A and Figure 3B The phosphor in region 22A, enclosed by a single-dotted line, specifically refers to the phosphor located directly above the light-emitting element 10. In contrast, in the first phosphor layer 20 and the second phosphor layer 60, there is no phosphor directly above the light-emitting element 10, i.e. Figure 3A and Figure 3B The phosphor in region 23A, not enclosed by a single-dotted line, receives less excitation light, resulting in minimal or no heat generation. Therefore, as... Figure 3A and Figure 3B As shown by the arrow, heat conduction occurs from the region 22A with high heat generation to the region 23A with low heat generation.

[0080] The filling member 30A is located directly below the region 23A where heat generation is low, and the upper surface 31A of the filling member 30A abuts against the region 23A. Therefore, heat conducted to the region 23A is conducted from the region 23A to the filling member 30A, and then the heat conducted to the filling member 30A is conducted from the filling member 30A to the substrate 40.

[0081] Furthermore, as described above, the first phosphor layer 20 abuts against the upper surface 11 of the plurality of light-emitting elements 10. Therefore, as... Figure 3A As indicated by the arrow, the heat generated in region 22A of the first phosphor layer 20 is conducted from the first phosphor layer 20 to the light-emitting element 10 directly below it, and then the heat conducted to the light-emitting element 10 is conducted from the light-emitting element 10 to the substrate 40. In addition, the heat conducted to the substrate 40 is dissipated to the outside of the substrate 40.

[0082] Thus, in the light-emitting device 2 of this embodiment, heat generated in region 22A of the first phosphor layer 20 and the second phosphor layer 60 is conducted to the relatively low-temperature region 23A, and then from region 23A to the filling member 30A and then to the substrate 40. Simultaneously, heat generated in region 22A of the first phosphor layer 20 is conducted to the light-emitting element 10, and then from the light-emitting element 10 to the substrate 40. Therefore, heat dissipation in region 22A of the first phosphor layer 20 and the second phosphor layer 60 is efficiently achieved, thereby suppressing temperature quenching of the phosphor contained in region 22A.

[0083] Here, in Figure 3A In the light-emitting device 2 shown, the height of the filling member 30 covering the entire periphery of the light-emitting element 10 is approximately the same as the height of the plurality of light-emitting elements 10. Therefore, the side surfaces of the first phosphor layer 20 and the second phosphor layer 60 are not in contact with the filling member 30. However, this embodiment is not limited to this configuration.

[0084] It can also be like Figure 4 As shown in the light-emitting device 3, the height of the filling member 30 is approximately the same as the height of the stack of the light-emitting element 10, the first phosphor layer 20, and the second phosphor layer 60, such that the sides of the first phosphor layer 20 and the second phosphor layer 60 are in contact with the filling member 30. In this way, the sides of the first phosphor layer 20 and the second phosphor layer 60 are covered by the filling member 30, thereby allowing heat generated by the first phosphor layer 20 and the second phosphor layer 60 to be conducted to the filling member 30 for heat dissipation. Therefore, the heat dissipation performance of the first phosphor layer 20 and the second phosphor layer 60 can be further improved.

[0085] [Third Implementation Method] Next, the light-emitting device of the third embodiment will be described in detail. Furthermore, the same reference numerals are used for components identical to those in the first and second embodiments, and repeated descriptions are omitted.

[0086] like Figure 5 As shown, the light-emitting device 4 of the third embodiment includes a plurality of light-emitting elements 10 arranged at predetermined intervals, a first phosphor layer 20, and filling members 30, 30A. Furthermore, with... Figure 4 The light-emitting device 3 shown is the same, with a second phosphor layer 60 stacked on the first phosphor layer 20, and the sides of the first phosphor layer 20 and the sides of the second phosphor layer 60 are covered by the filling member 30.

[0087] As described in the second embodiment, the heat dissipation of the first phosphor layer 20 and the second phosphor layer 60 is improved in the light-emitting device 2. Therefore, even if a phosphor layer 70 is further stacked on the second phosphor layer 60, the temperature rise of the first phosphor layer 20 and the second phosphor layer 60 can be suppressed. In addition, by including other phosphor layers 70 besides the first phosphor layer 20 and the second phosphor layer 60, a light-emitting device capable of emitting fluorescence of multiple wavelengths can be obtained.

[0088] The third phosphor layer 70 can be composed of phosphor ceramic formed by sintering a phosphor, or it can be a wavelength conversion component in which the phosphor is dispersed within a light-transmitting material. Furthermore, the light-transmitting material used in the wavelength conversion component can be a resin, such as an organosilicon resin. The phosphor included in the third phosphor layer 70 is not particularly limited, and at least one of blue phosphors, green phosphors, yellow phosphors, red phosphors, and near-infrared phosphors can be used. Additionally, the aforementioned materials can be used for blue phosphors, green phosphors, yellow phosphors, red phosphors, and near-infrared phosphors.

[0089] In the light-emitting device 4, the third phosphor layer 70 is laminated on the upper surface 61 of the second phosphor layer 60, and is a plate-like component covering the upper surface 61 of the second phosphor layer 60. Furthermore, the third phosphor layer 70 can be directly laminated on the upper surface 61 of the second phosphor layer 60, or it can be laminated via an adhesive layer. The adhesive layer used to bond the second phosphor layer 60 and the third phosphor layer 70 is not particularly limited; for example, at least one of a transparent inorganic adhesive and an organic adhesive can be used.

[0090] The operation of the light-emitting device 4 of this embodiment, having such a configuration, will be explained. In the light-emitting device 4 of this embodiment, firstly, when power is applied to the light-emitting element 10, excitation light (primary light) is emitted upward from the light-emitting element 10. The emitted excitation light passes through the first phosphor layer 20, the second phosphor layer 60, and the third phosphor layer 70. At this time, a portion of the excitation light is absorbed by the fluorescent ions of the phosphors contained in the first phosphor layer 20 and the second phosphor layer 60. Similarly, a portion of the excitation light is absorbed by the fluorescent ions of the phosphors contained in the third phosphor layer 70. Then, the fluorescent ions are converted into fluorescence through electron energy transitions, and the fluorescence is emitted upward from the phosphors. Alternatively, in the light-emitting device 4, the phosphors of the third phosphor layer 70 may absorb the fluorescence emitted from the phosphors of the first phosphor layer 20 and / or the second phosphor layer 60, emitting fluorescence with a longer wavelength.

[0091] In the light-emitting device 4, the phosphor contained in the first phosphor layer 20 can be (Ga,Sc)₂O₃:Cr, which is a near-infrared phosphor. 3+The phosphor contained in the second phosphor layer 60 is Gd3Ga2(GaO4)3:Cr, which is a near-infrared phosphor. 3+ Furthermore, the phosphor contained in the third phosphor layer 70 can be CaAlSiN3:Eu, which is a red phosphor. 2+ By using such a phosphor, a light-emitting device 4 capable of emitting near-infrared and red light can be obtained. Moreover, such a light-emitting device 4 can be used as a light source for quality inspection of objects using near-infrared and red light.

[0092] In the light-emitting device 4, the third phosphor layer 70 is preferably a wavelength conversion member in which phosphor particles are dispersed within a light-transmitting resin. The refractive index of the light-transmitting resin is intermediate between the refractive index of the second phosphor layer 60, which is composed of phosphor ceramic, and the refractive index of air. That is, when fluorescence transmitted through the second phosphor layer 60 is emitted to the outside of the light-emitting device 4, the third phosphor layer 70 functions as an intermediate refractive index layer between the phosphor ceramic and air. Therefore, the light extraction efficiency from the light-emitting device 4 can be improved.

[0093] (Postscript) Based on the above description of the embodiments, the following technology is disclosed.

[0094] (Technology 1) A light-emitting device comprising: a plurality of light-emitting elements arranged at predetermined intervals; a first phosphor layer made of phosphor ceramic; and a filling member covering the sides of the plurality of light-emitting elements and disposed between adjacent light-emitting elements. The first phosphor layer is a plate-shaped component covering the light-emitting surface of the plurality of light-emitting elements, and the first phosphor layer is configured to abut against the plurality of light-emitting elements and the filling component.

[0095] According to this configuration, heat generated in region 22 of the first phosphor layer 20 is conducted to the relatively low-temperature region 23, and then from region 23 to the filling member 30A and subsequently to the substrate 40. Simultaneously, heat generated in region 22 of the first phosphor layer 20 is conducted to the light-emitting element 10, and then from the light-emitting element 10 to the substrate 40. Therefore, heat dissipation of the first phosphor layer 20 is efficiently achieved, thereby suppressing temperature quenching of the phosphor.

[0096] (Technology 2) According to the light-emitting device of Technology 1, when viewed from above the light-emitting surface of the plurality of light-emitting elements, the external dimensions of the first phosphor layer are approximately the same as the external dimensions of the plurality of light-emitting elements.

[0097] According to this configuration, the output light emitted from the light-emitting device is difficult to diffuse. Therefore, the output light can be easily captured by a lens disposed near the light-emitting device, enabling the lens to be miniaturized. Furthermore, by miniaturizing the lens, the housing containing both the lens and the light-emitting device can also be miniaturized.

[0098] (Technology 3) The light-emitting device according to Technology 1 or 2, wherein a second phosphor layer is further comprising a second phosphor layer stacked on the first phosphor layer.

[0099] Because the heat dissipation of the first phosphor layer 20 is improved in the light-emitting device of this embodiment, even if a second phosphor layer 60 is further stacked on the first phosphor layer 20, the temperature rise of the first phosphor layer 20 can be suppressed. Furthermore, by including a second phosphor layer 60 in addition to the first phosphor layer 20, a light-emitting device that emits fluorescence of multiple wavelengths can be obtained.

[0100] (Technology 4) The light-emitting device according to Technology 3, wherein the second phosphor layer is composed of phosphor ceramic.

[0101] According to this configuration, the heat emitted by the phosphor in the second phosphor layer 60 can be dissipated efficiently, and the temperature quenching of the phosphor can be suppressed.

[0102] (Technology 5) The light-emitting device according to Technology 3 or 4, wherein, when viewed from above the light-emitting surface of the plurality of light-emitting elements, the external dimensions of the second phosphor layer are approximately the same as those of the first phosphor layer.

[0103] According to this configuration, the output light emitted from the light-emitting device is difficult to diffuse. Therefore, the output light can be easily captured by a lens disposed near the light-emitting device, enabling the lens to be miniaturized. Furthermore, by miniaturizing the lens, the housing containing both the lens and the light-emitting device can also be miniaturized.

[0104] (Technology 6) The light-emitting device according to any one of Technology 3 to 5, wherein the second phosphor layer is bonded to the first phosphor layer.

[0105] With this configuration, the first phosphor layer 20 and the second phosphor layer 60 are bonded together, enabling a tight interface between them. Therefore, heat conduction between the first phosphor layer 20 and the second phosphor layer 60 is easily achieved, thus improving the heat dissipation of both layers.

[0106] (Technology 7) The light-emitting device according to any one of Technology 3 to 6, wherein the side surfaces of the first phosphor layer and the side surfaces of the second phosphor layer are covered by the filling member.

[0107] According to this configuration, the heat generated by the first phosphor layer 20 and the second phosphor layer 60 can be conducted to the filling member 30 for heat dissipation. Therefore, the heat dissipation performance of the first phosphor layer 20 and the second phosphor layer 60 can be further improved.

[0108] (Technology 8) The light-emitting device according to any one of Technologies 1 to 7, wherein the filling member comprises a reflective material that reflects light.

[0109] According to this configuration, since the excitation light emitted from the light-emitting element 10 and the fluorescence emitted from the phosphor are reflected, the propagation of light emitted from the light-emitting element 10, the first phosphor layer 20 and the second phosphor layer 60 can be suppressed, and light leakage can be reduced. Therefore, the luminous efficiency of the light-emitting device can be improved.

[0110] (Technology 9) The light-emitting device according to any one of Technologies 3 to 8, wherein it further comprises one or more phosphor layers stacked on the second phosphor layer.

[0111] In this embodiment, the heat dissipation of the first phosphor layer 20 and the second phosphor layer 60 is improved, so even if a phosphor layer 70 is further stacked on the second phosphor layer 60, the temperature rise of the first phosphor layer 20 and the second phosphor layer 60 can be suppressed. Furthermore, by including other phosphor layers 70 besides the first phosphor layer 20 and the second phosphor layer 60, a light-emitting device that emits fluorescence of multiple wavelengths can be obtained.

[0112] (Technology 10) The light-emitting device according to any one of technologies 3 to 9, further comprising a third phosphor layer stacked on the second phosphor layer, The third phosphor layer comprises phosphor particles and a resin for dispersing the phosphor particles.

[0113] Based on this configuration, a light-emitting device that emits fluorescence of multiple wavelengths can be obtained. Furthermore, the third phosphor layer 70 functions as an intermediate refractive index layer between the phosphor ceramic and air, thereby improving the light extraction efficiency from the light-emitting device.

[0114] Example The present embodiment will be described in more detail below through examples and comparative examples, but the present embodiment is not limited to these examples.

[0115] [Example 1] (Preparation of the first fluorophore layer) First, a first phosphor layer for use in the light-emitting device is synthesized using a solid-state reaction synthesis method. The first phosphor constituting the first phosphor layer is a near-infrared phosphor, which is composed of (Ga) 0.59 Cr 0.01 Sc 0.4The oxide phosphor is represented by the compositional formula (Ga,Sc)₂O₃. Additionally, in this specification, (Ga,Sc)₂O₃:Cr 3+ The phosphor is called a "GaSc phosphor".

[0116] The following compound powders were used as the main raw materials in the synthesis of the first phosphor layer.

[0117] Gallium oxide (Ga2O3): Purity 4N, Asia Physical Properties Co., Ltd. Chromium trioxide (Cr2O3): Purity 3N, High Purity Chemical Research Institute, Inc. Scandium oxide (Sc2O3): Purity >3N, High Purity Chemical Research Institute, Inc. In addition, to improve the reactivity of the raw materials, the following compound powders are used as reaction promoters.

[0118] Boric acid (H3BO3): Fujifilm and Koko Pure Chemical Industries Co., Ltd. First, the compound with a stoichiometric composition (Ga) 0.59 Cr 0.01 Sc 0.4 The above raw materials were weighed in the manner of 2O3. Additionally, the weights were measured relative to the target compound (Ga2O3). 0.59 Cr 0.01 Sc 0.4 The reaction accelerator was weighed at a molar ratio of 3% to 2O3. Next, the weighed raw materials and reaction accelerator were added to a cylindrical container, followed by the addition of an appropriate amount of pure water. Then, the container containing the raw materials, reaction accelerator, and pure water was placed in a planetary mill (Fritsch Japan Co., Ltd., PULVERISETTE5) to thoroughly wet mix the raw materials and reaction accelerator. The planetary mill was rotated at 200 rpm for 30 minutes.

[0119] Next, the slurry-like mixture containing the raw materials, reaction promoter, and pure water was transferred to a metal container lined with Naflon (registered trademark) sheets and dried at 150°C for approximately 3 hours using a dryer to evaporate the pure water. Then, the dried mixture was gently pulverized using a mortar and pestle. Finally, coarse particles of the pulverized mixture were removed using a sieve with a mesh size of approximately 512 μm. This yielded the mixture for the first phosphor layer.

[0120] Next, a manual hydraulic press (manufactured by Riken Seiki Co., Ltd.) and a cylindrical mold ( The mixed raw material of the first phosphor layer (13 mm) is molded into a thin cylindrical shape. Additionally, a pressure of approximately 20 MPa is applied to the pressure surface of the sample during molding. This yields a molded body of the mixed raw material.

[0121] Next, the molded body of the mixed raw materials was fired using a box-type atmospheric furnace. The processing temperature was set at 1400℃, and the processing time was set at 4 hours. This yielded the fired body of the mixed raw materials.

[0122] Then, the upper and lower surfaces of the sintered body were ground using a grinding apparatus (DISCO Corporation, DFD6340). The grinding blade used was a 1400 grit. The thickness of the sintered body after grinding was approximately 100 μm. Next, the ground sintered body was cut into thin cuboid shapes using a cutting apparatus (DISCO Corporation, DAD3350). The outer diameter of the cut cuboid, viewed from above, was approximately 3.3 mm long and 2.6 mm wide. This yielded the sintered (Ga,Sc)₂O₃:Cr 3+ The first phosphor layer is formed.

[0123] (Preparation of the second fluorophore layer) Next, a second phosphor layer for use in the light-emitting device was synthesized using a solid-state reaction synthesis method. The second phosphor constituting the second phosphor layer is a near-infrared phosphor, which is based on Gd3(Ga)2+. 0.97 Cr 0.03 )2Ga3O 12 The compositional formula of the oxide phosphor is represented by Gd3Ga2Ga3O. Additionally, in this specification, Gd3Ga2Ga3O is also used. 12 Cr 3+ The phosphor is called a "GGG phosphor".

[0124] The following compound powders were used as the main raw materials in the synthesis of the second phosphor layer.

[0125] Gadolinium oxide (Gd2O3): purity 4N, Japan Yttrium Co., Ltd. Gallium oxide (Ga2O3): Purity 4N, Asia Physical Properties Co., Ltd. Chromium trioxide (Cr2O3): Purity 3N, High Purity Chemical Research Institute, Inc. First, the compound Gd3 (Ga) has a stoichiometric composition. 0.97 Cr 0.03 )2Ga3O 12The raw materials were weighed using the following method. Next, the weighed raw materials and reaction accelerator were added to a cylindrical container, followed by the addition of an appropriate amount of ethanol. Then, the container containing the raw materials, reaction accelerator, and ethanol was placed in a planetary mill (Fritsch Japan Co., Ltd., PULVERISETTE5) to thoroughly wet mix the raw materials and reaction accelerator. The planetary mill was rotated at 200 rpm for 30 minutes.

[0126] Next, the slurry-like mixture containing the raw materials, reaction promoter, and ethanol was transferred to a metal container lined with Naflon sheets and dried at 125°C for approximately 2 hours to evaporate the ethanol. Then, the dried mixture was gently pulverized using a mortar and pestle. Finally, coarse particles of the pulverized mixture were removed using a sieve with a mesh size of approximately 516 μm. This yielded the mixture for the second phosphor layer.

[0127] Next, a manual hydraulic press (manufactured by Riken Seiki Co., Ltd.) and a cylindrical mold ( The mixture of materials for the second phosphor layer (13 mm) is molded into a thin cylindrical shape. Additionally, a pressure of approximately 20 MPa is applied to the pressure surface of the sample during molding. This yields a molded body of the mixture.

[0128] Next, the shaped body of the mixed raw materials was fired using a Taman tube-type atmosphere electric furnace. The firing atmosphere was nitrogen, the processing temperature was 1600℃, and the processing time was 2 hours. In this way, the fired body of the mixed raw materials was obtained.

[0129] Then, the upper and lower surfaces of the sintered body were ground using a grinding apparatus (DISCO Corporation, DFD6340). The grinding blade used was a 1400 grit abrasive. The thickness of the sintered body after grinding was approximately 100 μm. Next, the ground sintered body was cut into thin rectangular parallelepiped shapes using a cutting apparatus (DISCO Corporation, DAD3350). The outer diameter of the cut rectangular parallelepiped, viewed from above, was approximately 3.3 mm long and 2.6 mm wide. This yielded a Gd3Ga2Ga3O4 composite material. 12 Cr 3+ The second phosphor layer is formed by sintering.

[0130] (Density determination of the first and second fluorophores) The densities of the first and second fluorophore layers obtained as described above were determined. Specifically, the weight and volume of the first fluorophore layer were measured, and the density of the first fluorophore layer was evaluated by dividing the measured weight by the measured volume. The evaluation result showed that the density of the first fluorophore layer was 4.59 g / cm³.3 The density of the second fluorophore layer was evaluated using the Archimedes method. The result was that the density of the second fluorophore layer was 6.94 g / cm³. 3 .

[0131] (Calculation of thermal conductivity of the first and second phosphor layers) The specific heat capacity and thermal diffusivity of the first and second phosphor layers were evaluated using a xenon flash analyzer (NETZSCH Japan Co., Ltd., LFA447). The results showed that the specific heat capacities of the first and second phosphor layers were 0.561 J / g / K and 0.352 J / g / K, respectively. Furthermore, the thermal diffusivity of the first and second phosphor layers was 3.36 mm. 2 / s, 2.67mm 2 / s.

[0132] Here, thermal conductivity is the product of density, specific heat capacity, and thermal diffusivity; therefore, this formula is used to calculate the thermal conductivity of the first and second phosphor layers. The results show that the thermal conductivity of the first and second phosphor layers are 8.64 J / s / m / K and 6.52 J / s / m / K, respectively.

[0133] (The creation of the light-emitting device) Using the first phosphor layer and the second phosphor layer obtained as described above, a light-emitting device is fabricated. First, a commercially available multi-chip LED package comprising a substrate, four blue LEDs, and a dam material is prepared.

[0134] Four blue LEDs are mounted on the substrate, such as Figure 1C As shown, they are arranged in two columns along the X-axis and two columns along the Y-axis. Adjacent blue LEDs are arranged at predetermined intervals. Each blue LED has an outer diameter of approximately 1.2mm × 1.5mm, and the interval between adjacent blue LEDs is approximately 0.15mm. The four blue LEDs together have an outer diameter of approximately 2.6 × 3.2mm.

[0135] like Figure 1C As shown, the dam material is set around the entire structure of 4 blue LEDs.

[0136] Next, a white resin, serving as a filler, is applied between the four blue LEDs and the dam material, and between adjacent blue LEDs in the multi-chip LED package, and then cured to form the filler. It should be noted that the white resin used is LED silicone KER-2016WC-A / B manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0137] Next, the first phosphor layer is bonded to the blue LED using an adhesive. It should be noted that the adhesive used is KER-2600-A / B LED silicone manufactured by Shin-Etsu Chemical Co., Ltd.

[0138] Thus, as Figure 1A and Figure 1B As shown, a light-emitting device having a first phosphor layer as described in Example 1-1 is obtained. Furthermore, in this embodiment, the height of the filling member is adjusted such that the side of the first phosphor layer contacts the filling member. Additionally, in the light-emitting device of Example 1-1, the difference between the external dimensions of the four blue LEDs and the external dimensions of the first phosphor layer is 5% or less.

[0139] Furthermore, a second phosphor layer is bonded to the first phosphor layer in the light-emitting device of Example 1-1. It should be noted that the adhesive used is LED silicone KER-2600-A / B manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0140] Thus, as Figure 4 As shown, the light-emitting devices of Examples 1-2, which include a first phosphor layer and a second phosphor layer, are obtained. Furthermore, in this embodiment, the height of the filling member is adjusted such that the sides of the first and second phosphor layers contact the filling member. Additionally, in the light-emitting devices of Examples 1-2, the difference between the external dimensions of the four blue LEDs and the external dimensions of the first phosphor layer is 5% or less. Furthermore, the difference between the external dimensions of the first phosphor layer and the external dimensions of the second phosphor layer is 5% or less.

[0141] (The outline of the light beam from the light-emitting device) The intensity distribution of light emitted from the light-emitting devices of Examples 1-1 and 1-2 was measured using a beam profiler. Figure 6 This shows the luminous intensity distribution of the light-emitting device in Example 1-1. Figure 7 The diagram shows the luminous intensity distribution of the light-emitting devices in Examples 1-2. Furthermore, the near-infrared phosphors in the first and second phosphor layers absorb blue light and convert their wavelength to near-infrared light; therefore, the portion with high luminous intensity can be considered as the portion with high heat generation.

[0142] like Figure 6 As shown, in the light-emitting device of Embodiment 1-1, the luminous intensity and heat generation are both high in the area directly above the blue LEDs. Conversely, the luminous intensity and heat generation are low in the area between the blue LEDs. Furthermore, the luminous intensity and heat generation are also low near the sides of the first phosphor layer.

[0143] In addition, such as Figure 7As shown, the light-emitting devices of Examples 1-2 exhibit high luminous intensity and high heat generation in the area directly above the blue LEDs. Conversely, the luminous intensity and heat generation are low in the area between the blue LEDs. Furthermore, the luminous intensity and heat generation are also low near the sides of the second phosphor layer.

[0144] [Example 2] Next, the temperature distribution of the first phosphor layer and the second phosphor layer in the light-emitting devices of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3 was analyzed using CAE (Computer Aided Engineering).

[0145] (Analytical Model) Figure 8 This shows the overall shape of the analytical model used in CAE parsing. Figure 9 , Figure 10A and Figure 10B The light-emitting module is shown schematically. (Example) Figure 8 As shown, in CAE parsing, the surrounding area 100 is set as... A 450mm spherical region composed of air. The origin is the center of the surrounding region 100, and the direction of gravity is the -Z direction. Furthermore, this spherical region is assumed to be an integrating sphere. The light-emitting module 110 is arranged such that the light-emitting part (light-emitting element) is located at the center of the surrounding region 100.

[0146] The light-emitting module 110 includes an aluminum substrate 111, a heat sink 112, and a fan 113. Furthermore, the light-emitting module 110 does not include a lens or a cylindrical housing. Moreover, the light-emitting module 110 is configured with the light-emitting direction facing upwards (Z direction).

[0147] The aluminum substrate 111 is made of aluminum, and a countersunk hole 111a for holding the light-emitting device 1 is formed on its upper surface. The aluminum substrate 111 has dimensions of 55 mm in the longitudinal (X direction), 55 mm in the transverse (Y direction), and 10 mm in the height (Z direction), and the depth of the countersunk hole is 2 mm. Furthermore, the thermal conductivity of the aluminum substrate 111 is set to 138 W / m·K.

[0148] The heat sink 112 has an aluminum base 111 on its upper surface, which measures 59 mm in length, 59 mm in width, and 30 mm in height. Furthermore, the thermal conductivity of the heat sink 112 is set to 180 W / m·K.

[0149] The fan 113 is cylindrical, with a heat sink 112 mounted on its upper surface. Furthermore, the size of the fan 113 is... 55mm in diameter and 25mm in height. In addition, fan 113 is set to generate only an upward airflow of 2m / s.

[0150] In addition, contact thermal resistance simulating TIM (Thermal Interface Material) material is set between the light-emitting device 1 and the aluminum substrate 111, and between the aluminum substrate 111 and the heat sink 112. The contact thermal resistance has a thickness of 300 μm and a thermal conductivity of 1.5 W / m·K.

[0151] like Figure 10A and Figure 11 As shown, the light-emitting device 1 includes multiple light-emitting elements 10, a first phosphor layer 20, a second phosphor layer 60, a third phosphor layer 70, filling members 30 and 30A, a substrate 40, and a dam material 50. The light-emitting elements 10 are LEDs that are stacked with GaN and Si3N4. The GaN has a thickness of 10 μm, a thermal conductivity of 160 W / m·K, and a heat output of 22.07 W. The Si3N4 has a thickness of 90 μm and a thermal conductivity of 85 W / m·K.

[0152] The first phosphor layer 20 is a phosphor ceramic composed of GaSc phosphors, with a thickness of 100 μm, a thermal conductivity of 8.6 W / m·K, and a calorific value of 8.00 W. The second phosphor layer 60 is a phosphor ceramic composed of GGG phosphors, with a thickness of 100 μm, a thermal conductivity of 6.5 W / m·K, and a calorific value of 1.84 W. The third phosphor layer 70 is a CASN paste formed by dispersing CASN in organosilicon resin, with a thickness of 120 μm, a thermal conductivity of 0.2 W / m·K, and a calorific value of 0.72 W.

[0153] Furthermore, a simulated adhesive contact thermal resistance is set between the substrate 40 and the light-emitting element 10, with a thickness of 20 μm and a thermal conductivity of 57 W / m·K. A simulated adhesive contact thermal resistance is also set between the light-emitting element 10 and the first phosphor layer 20, with a thickness of 10 μm and a thermal conductivity of 0.2 W / m·K. A simulated adhesive contact thermal resistance is also set between the first phosphor layer 20 and the second phosphor layer 60, with a thickness of 10 μm and a thermal conductivity of 0.2 W / m·K.

[0154] The thickness of the filling components 30 and 30A is set to 0.42 mm, and the thermal conductivity is set to 0.2 W / m·K. The dam material 50 is 9 mm long (X direction), 10 mm wide (Y direction), 0.4 mm high (Z direction), and 1 mm wide, with a thermal conductivity set to 0.2 W / m·K. The substrate 40 is made of copper substrate, with dimensions of 15.5 mm long (X direction), 27 mm wide (Y direction), and 1.5 mm high (Z direction). Furthermore, the thermal conductivity of the substrate 40 is set to 398 W / m·K.

[0155] exist Figure 12The image shows the configuration of four light-emitting elements 10 and a dam material 50 mounted on a substrate 40. (As shown...) Figure 12 As shown, four light-emitting elements 10 are arranged in two rows along the X-axis and two rows along the Y-axis, and a dam material 50 is integrally provided around the light-emitting elements. Furthermore, adjacent light-emitting elements 10 are arranged at predetermined intervals. In addition, the external dimensions of the four light-emitting elements 10 in the Y-axis direction are 3.2 mm, and the external dimensions in the X-axis direction are 2.6 mm. Furthermore, the dimensions of a single light-emitting element 10 are set to 1.525 mm × 1.225 mm, and the interval between adjacent light-emitting elements is set to 0.15 mm.

[0156] exist Figure 13 The diagram shows a configuration where filling members 30 and 30A are provided between four light-emitting elements 10 and a dam material 50, and phosphor layers (a first phosphor layer and a second phosphor layer) are stacked on the four light-emitting elements 10. The phosphor layer has a Y-axis dimension of 3.2 mm and an X-axis dimension of 2.6 mm. Furthermore, in... Figure 13 In the analytical model, only the phosphor layer located directly above the light-emitting element 10 is considered as the heating region, while the phosphor layer not located directly above the light-emitting element 10 is considered as the non-heat-emitting region.

[0157] Table 1 summarizes the components and settings of the analytical model of Example 2, and Table 2 summarizes the settings of the contact resistance between each component. Furthermore, as analytical conditions other than the settings in Tables 1 and 2, the ambient temperature of the surrounding area 100 is set to 30°C, the wind speed of the fan 113 is set to 2.0 m / s, the wind direction is set to +Z, and the gravity is set to -Z. Also, the CAE analysis is a steady-state analysis, and the number of cycles is set to 1000.

[0158] (Structure of the light-emitting device in Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3) The structures of the light-emitting devices of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3, for which CAE analysis was performed, are shown below. Figure 14 The light-emitting device of Embodiment 2-1 includes a light-emitting element 10, a first phosphor layer 20, filling members 30 and 30A, a substrate 40, and a dam material 50. The light-emitting devices of Embodiments 2-2 and 2-3 include a light-emitting element 10, a first phosphor layer 20, a second phosphor layer 60, filling members 30 and 30A, a substrate 40, and a dam material 50. Furthermore, in the light-emitting device of Embodiment 2-2, the second phosphor layer 60 located directly above the light-emitting element 10 is used as a heat-generating component. In addition, in the light-emitting device of Embodiment 2-3, the entire surface of the second phosphor layer 60 is used as a heat-generating component.

[0159] Similar to Example 2-1, the light-emitting element of Comparative Example 2-1 includes a light-emitting element 10, a first phosphor layer 20, filling members 30, 30A, a substrate 40, and a dam material 50. However, as Figure 14 As shown, the first phosphor layer 20 is divided into four pieces instead of one plate-like component, and thus is stacked only directly above the four light-emitting elements 10. Therefore, the filling component 30A fills the space between adjacent light-emitting elements 10 and adjacent first phosphor layers 20.

[0160] The light-emitting device of Comparative Example 2-2 includes a light-emitting element 10, a first phosphor layer 20, a second phosphor layer 60, filling members 30 and 30A, a substrate 40, and a dam material 50. However, as Figure 14 As shown, the first phosphor layer 20 is divided into four pieces instead of a single plate-like component, and thus is stacked only directly above the four light-emitting elements 10. Similarly, the second phosphor layer 60 is not a single plate-like component but is divided into four pieces, and thus is stacked only directly above the four light-emitting elements. Therefore, the filling member 30A fills the spaces between adjacent light-emitting elements 10, adjacent first phosphor layers 20, and adjacent second phosphor layers 60.

[0161] The light-emitting device of Comparative Example 2-3 includes a light-emitting element 10, a first phosphor layer 20, a substrate 40, and a dam material 50. That is, the light-emitting device of Comparative Example 2-3 is the configuration after removing the filling members 30 and 30A from the light-emitting device of Example 2-1.

[0162] (CAE parsing results) exist Figure 14 The results of CAE analysis are shown, specifically the temperatures of the light-emitting surfaces of the first phosphor layer 20 and the second phosphor layer 60 in each embodiment and comparative example. Figure 15 In the light-emitting devices of Examples 2-1, 2-1, and 2-3, the temperature distribution (contour plot) of the surface of the light-emitting side of the first phosphor layer 20 is shown. Additionally, in... Figure 15 In Comparative Example 2-1, in addition to the first phosphor layer, the temperature distribution of the filling member present between the first phosphor layers is also shown. Furthermore, in Figure 16 In, it is shown that in Figure 15 The temperature distribution depicts the results of the temperature along the diagonal of the first phosphor layer. Specifically, Figure 16 Along Figure 15 The dashed line in the figure represents the relationship between the diagonal distance and the surface temperature of the first phosphor layer 20.

[0163] like Figure 16As shown, the surface temperature of the first phosphor layer 20 in the light-emitting device of Example 2-1 is generally lower than that in the light-emitting device of Comparative Example 2-3, which does not have a filling member. Furthermore, it is known that the surface temperature of the light-emitting device of Comparative Example 2-1 is low in the diagonal distance of 2 to 2.2 mm where the filling member is present, but the surface temperature of the remaining portions is higher than that of the light-emitting device of Example 2-1.

[0164] In this way, by fabricating the first phosphor layer into a plate-like structure and configuring it to abut against multiple light-emitting elements and filling components, heat conduction is achieved towards the region 23 with low heat generation and the filling component 30A. As a result, heat dissipation from the first phosphor layer is efficiently achieved.

[0165] exist Figure 17 The results of CAE analysis are shown, specifically, in the light-emitting devices of Examples 2-2, 2-3, and Comparative Example 2-2, the temperature distribution (contour plot) of the surfaces on the light-emitting side of the first phosphor layer 20 and the second phosphor layer 60 is shown. Additionally, in Figure 17 In Comparative Example 2-2, in addition to the first phosphor layer, the temperature distribution of the filling material present between the first phosphor layers is also shown. Similarly, in Figure 17 In Comparative Example 2-2, in addition to the second phosphor layer, the temperature distribution of the filling member present between the second phosphor layers is also shown.

[0166] exist Figure 18 In, it is shown that in Figure 17 The temperature distribution depicts the results of the temperature along the diagonal of the first phosphor layer. Specifically, Figure 18 Along Figure 17 The dashed line in the figure represents the relationship between the diagonal distance and the surface temperature of the first phosphor layer 20. Figure 19 In, it is shown that in Figure 17 The temperature distribution depicts the temperature along the diagonal of the second phosphor layer. Specifically, Figure 19 Along Figure 17 The dashed line in the figure represents the relationship between the diagonal distance and the surface temperature of the second phosphor layer 60.

[0167] like Figure 18 As shown, the surface temperature of the light-emitting device of Comparative Example 2-2 is low in the area with a diagonal distance of 2 to 2.2 mm where the first phosphor layer is absent and a filling member is present, but the surface temperature of the remaining portion is higher than that of the light-emitting device of Example 2-2. In particular, the surface temperature of the light-emitting device of Example 2-2 is significantly lower than that of the light-emitting device of Comparative Example 2-2 in the area with a diagonal distance of 1 to 3 mm. Furthermore, the surface temperature of the light-emitting device of Example 2-3 is lower than that of the light-emitting device of Comparative Example 2-2 in the area with a diagonal distance of 1 to 3 mm.

[0168] In addition, such as Figure 19 As shown, the surface temperature of the light-emitting device of Comparative Example 2-2 is low in the area with a diagonal distance of 2 to 2.2 mm where there is no second phosphor layer and a filling member is present, but the overall surface temperature is higher than that of the light-emitting device of Example 2-2. In particular, it is known that the surface temperature of the light-emitting device of Example 2-2 is significantly lower than that of the light-emitting device of Comparative Example 2-2 in the area with a diagonal distance of 1 to 3 mm. In addition, it is known that the surface temperature of the light-emitting device of Example 2-2 is lower than that of the light-emitting device of Comparative Example 2-2 in the area with a diagonal distance of 1 to 3 mm.

[0169] In this way, by treating the first phosphor layer and the second phosphor layer as plate-like components, and configuring the first phosphor layer to abut against multiple light-emitting elements and filling components, heat conduction is generated towards the region 23A with low heat generation and the filling component 30A. As a result, heat dissipation from the first phosphor layer and the second phosphor layer is efficiently achieved.

[0170] Furthermore, according to Figure 15 Based on the CAE analysis results, in the light-emitting device of Example 2-1 and the light-emitting devices of Comparative Examples 2-1 and 2-3, the average value of the decrease in surface temperature of the first phosphor layer and the maximum width of the decrease in surface temperature of the first phosphor layer were determined.

[0171] As shown in Table 3, within the range of 1.01~1.91 mm and 2.25~3.14 mm for the diagonal distance of the first phosphor layer, the surface temperature of the first phosphor layer in the light-emitting device of Example 2-1 was reduced by an average of 2.5 °C compared to the light-emitting device of Comparative Example 2-1. Furthermore, within the range of 1.01~1.91 mm and 2.25~3.14 mm for the diagonal distance, the surface temperature of the first phosphor layer in the light-emitting device of Example 2-1 was reduced by an average of 6.3 °C compared to the light-emitting device of Comparative Example 2-3.

[0172] Furthermore, even across the entire range of diagonal distances from 0.00 to 4.04 mm, the light-emitting device of Example 2-1 experienced an average temperature reduction of 1.1°C compared to the light-emitting device of Comparative Example 2-1, and an average temperature reduction of 7.2°C compared to the light-emitting device of Comparative Example 2-3. Moreover, the maximum surface temperature difference between the first phosphor layer in the light-emitting device of Example 2-1 and the light-emitting device of Comparative Example 2-1 was 6.9°C. Additionally, the maximum surface temperature difference between the first phosphor layer in the light-emitting device of Example 2-1 and the light-emitting device of Comparative Example 2-3 was 26.2°C.

[0173] Thus, it can be seen that by making the first phosphor layer into a plate-like component and configuring the first phosphor layer to abut against multiple light-emitting elements and filling components, heat can be efficiently dissipated from the first phosphor layer as a whole.

[0174] In addition, according to Figure 17 Based on the CAE analysis results, in the light-emitting devices of Example 2-2 and Comparative Example 2-2, the average decrease in surface temperature of the first phosphor layer and the maximum width of the decrease in surface temperature of the first phosphor layer were determined. Similarly, the average decrease in surface temperature of the second phosphor layer and the maximum width of the decrease in surface temperature of the second phosphor layer were also determined.

[0175] As shown in Table 3, within the range of 1.01~1.91 mm and 2.25~3.14 mm for the diagonal distance of the first phosphor layer, the surface temperature of the first phosphor layer in the light-emitting device of Example 2-2 decreased by an average of 4.5 °C compared to the light-emitting device of Comparative Example 2-2. Furthermore, even within the entire range of 0.00~4.04 mm for the diagonal distance, the light-emitting device of Example 2-2 decreased by an average of 2.3 °C compared to the light-emitting device of Comparative Example 2-2. Moreover, the maximum surface temperature difference of the first phosphor layer between the light-emitting device of Example 2-2 and the light-emitting device of Comparative Example 2-2 was 8.6 °C.

[0176] Within the range of 1.01~1.91 mm and 2.25~3.14 mm for the diagonal distance of the second phosphor layer, the surface temperature of the second phosphor layer in the light-emitting device of Example 2-2 decreased by an average of 4.7 °C compared to the light-emitting device of Comparative Example 2-2. Furthermore, even within the entire range of 0.00~4.04 mm for the diagonal distance, the light-emitting device of Example 2-2 decreased by an average of 2.8 °C compared to the light-emitting device of Comparative Example 2-2. Moreover, the maximum surface temperature difference of the second phosphor layer between the light-emitting device of Example 2-2 and the light-emitting device of Comparative Example 2-2 was 9.6 °C.

[0177] Furthermore, according to Figure 17 Based on the CAE analysis results, the average value of the decrease in surface temperature of the first phosphor layer and the maximum width of the decrease in surface temperature of the first phosphor layer were determined in the light-emitting devices of Examples 2-3 and Comparative Example 2-2. Similarly, the average value of the decrease in surface temperature of the second phosphor layer and the maximum width of the decrease in surface temperature of the second phosphor layer were also determined.

[0178] As shown in Table 3, within the range of 1.01~1.91 mm and 2.25~3.14 mm for the diagonal distance of the first phosphor layer, the surface temperature of the first phosphor layer in the light-emitting device of Examples 2-3 decreased by an average of 3.3 °C compared to the light-emitting device of Comparative Example 2-2. Furthermore, even within the entire range of 0.00~4.04 mm for the diagonal distance, the light-emitting device of Examples 2-3 decreased by an average of 2.2 °C compared to the light-emitting device of Comparative Example 2-2. Moreover, the maximum surface temperature difference of the first phosphor layer between the light-emitting device of Examples 2-3 and the light-emitting device of Comparative Example 2-2 was 3.7 °C.

[0179] Within the range of 1.01~1.91 mm and 2.25~3.14 mm for the diagonal distance of the second phosphor layer, the surface temperature of the second phosphor layer in the light-emitting device of Examples 2-3 decreased by an average of 3.5 °C compared to the light-emitting device of Comparative Example 2-2. Furthermore, even within the entire range of 0.00~4.04 mm for the diagonal distance, the light-emitting device of Examples 2-3 decreased by an average of 2.8 °C compared to the light-emitting device of Comparative Example 2-2. Moreover, the maximum surface temperature difference of the second phosphor layer between the light-emitting device of Examples 2-3 and the light-emitting device of Comparative Example 2-2 was 3.8 °C.

[0180] Thus, it can be seen that by treating the first phosphor layer and the second phosphor layer as a plate-like component, and configuring the first phosphor layer to abut against multiple light-emitting elements and filling components, heat can be efficiently dissipated from the entire first phosphor layer and the second phosphor layer.

[0181] The above describes this embodiment, but this embodiment is not limited thereto, and various modifications can be made within the scope of the main idea of ​​this embodiment.

[0182] The entire contents of Japanese Patent Application No. 2023-185424 (application date: October 30, 2023) are quoted here.

[0183] Industrial availability According to this disclosure, a light-emitting device capable of efficiently dissipating heat from the phosphor layer can be provided.

[0184] Explanation of reference numerals in the attached figures 1, 2, 3, 4 Light-emitting devices 10 Light-emitting elements 20 First fluorophore layer 30, 30A Infill Components 60 Second fluorophore layer 70 Third fluorophore layer

Claims

1. A light-emitting device, characterized in that, have: Multiple light-emitting elements arranged at specified intervals; The first phosphor layer is composed of phosphor ceramic; and A filling member covering the sides of the plurality of light-emitting elements and disposed between adjacent light-emitting elements. The first phosphor layer is a plate-shaped component that covers the light-emitting surfaces of the plurality of light-emitting elements. The first phosphor layer is configured to abut against the plurality of light-emitting elements and the filling member.

2. The light-emitting device according to claim 1, wherein, When viewed from above the light-emitting surface of the plurality of light-emitting elements, the external dimensions of the first phosphor layer are approximately the same as those of the plurality of light-emitting elements.

3. The light-emitting device according to claim 1 or 2, wherein, It also has a second phosphor layer stacked on the first phosphor layer.

4. The light-emitting device according to claim 3, wherein, The second phosphor layer is composed of phosphor ceramic.

5. The light-emitting device according to claim 3 or 4, wherein, When viewed from above the light-emitting surface of the plurality of light-emitting elements, the external dimensions of the second phosphor layer are approximately the same as those of the first phosphor layer.

6. The light-emitting device according to any one of claims 3 to 5, wherein, The second phosphor layer is bonded to the first phosphor layer.

7. The light-emitting device according to any one of claims 3 to 6, wherein, The sides of the first phosphor layer and the sides of the second phosphor layer are covered by the filling member.

8. The light-emitting device according to any one of claims 1 to 7, wherein, The filling component contains a reflective material that reflects light.

9. The light-emitting device according to any one of claims 3 to 7, wherein, It also has one or more phosphor layers stacked on the second phosphor layer.

10. The light-emitting device according to any one of claims 3 to 7 and 9, wherein, It also has a third phosphor layer stacked on the second phosphor layer. The third phosphor layer comprises phosphor particles and a resin for dispersing the phosphor particles.

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