Wavelength conversion sintered body and white light-emitting element

Abstract

To provide a wavelength conversion sintered body and a white light-emitting element capable of improving luminous efficiency of white light and reducing chromaticity difference with respect to an emission angle.SOLUTION: A wavelength conversion sintered body (10) includes: a phosphor material (11) represented by a general formula Y3-x-yBaxAl5-xSixO12:Cey (where x+y<3, x<5, x>0, y>0); and particles (12) dispersed in the phosphor material (11). The fine particles (12) are a composite oxide of Ba, Si, and Al.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wavelength conversion sintered body and a white light emitting device. [Background technology]

[0002] Conventionally, white light sources that combine YAG phosphor with a blue LED (Light Emitting Diode) chip have been widely known. However, as the brightness of light sources has increased, thermal quenching has occurred due to heat concentration caused by wavelength conversion (Stokes loss) in the YAG phosphor, resulting in a decrease in the efficiency of the white light source. To address this issue, we have developed a YAG phosphor that is a solid solution of Ba and Si. 3-x-y Ba x Al 5-x Si x O 12 :Ce y A (BS-YAG) phosphor has been proposed (see Patent Document 1). This BS-YAG phosphor has the characteristics of having a higher wavelength conversion efficiency at high temperatures than general YAG phosphors and a wider chromaticity range of emission wavelengths. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-119163 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the blue light emitted by a blue LED chip has a high directivity in the direction perpendicular to the chip surface, so a wavelength conversion material made of YAG phosphor or BS-YAG phosphor is attached to the chip surface. In the wavelength conversion material, the primary blue light that reaches the phosphor material is wavelength-converted into secondary yellow light, and white light is emitted by mixing the blue and yellow light. In this case, the yellow light wavelength-converted by the phosphor material has an isotropic Lambertian light distribution.

[0005] However, when the wavelength conversion material has high light transmittance, the blue light from the blue LED chip has high vertical directivity and is extracted vertically from the surface of the wavelength conversion material. In contrast, yellow light has a Lambertian light distribution and is easily guided laterally through the wavelength conversion material, which can lead to chromaticity differences in the white light depending on the emission angle. Furthermore, the yellow light wavelength-converted by the phosphor material cannot be mixed well with the blue light, making it difficult to improve luminous efficiency.

[0006] Therefore, the present invention has been made in consideration of the above-mentioned conventional problems, and aims to provide a wavelength conversion sintered body and a white light-emitting element that can improve the luminous efficiency of white light and reduce the chromaticity difference with respect to the normal incidence angle. [Means for solving the problem]

[0007] In order to solve the above problems, the wavelength-converting sintered body of the present invention has the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y (where x+y<3, x<5, x>0, y>0) and fine particles dispersed in the phosphor material, wherein the fine particles are a composite oxide of Ba, Si, and Al.

[0008] In such a wavelength-converting sintered body of the present invention, fine particles of a composite oxide of Ba, Si, and Al are dispersed in the phosphor material, which scatters the secondary light wavelength-converted by the phosphor material with the fine particles, increasing the proportion of yellow light extracted from the surface, thereby improving the luminous efficiency of white light and reducing the chromaticity difference at normal angles.

[0009] In one aspect of the present invention, the fine particles are composited in the phosphor material.

[0010] In one aspect of the present invention, the composite oxide is represented by the general formula BaAl2Si z O2z+4 (where z=1,2,3···).

[0011] In one embodiment of the present invention, the fine particles have an average particle size in the range of 0.1 μm to 5 μm.

[0012] In one embodiment of the present invention, the composite oxide is contained in an amount of 1% to 5% by volume.

[0013] In one embodiment of the present invention, the material is formed into a plate shape with a thickness in the range of 0.01 mm to 0.5 mm.

[0014] In order to solve the above problems, the present invention provides a white light emitting device comprising any one of the above wavelength conversion sintered bodies bonded to a light emitting diode that emits blue light. [Effects of the Invention]

[0015] The present invention can provide a wavelength conversion sintered body and a white light emitting device that can improve the luminous efficiency of white light and reduce the chromaticity difference with respect to normal incidence angles. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view illustrating the structure of a wavelength conversion sintered body 10 according to a first embodiment and a white light emitting device 100 using the same. [Figure 2] 1 is a schematic diagram illustrating a method for measuring the luminous color and luminous intensity of a white light emitting element 100. FIG. [Figure 3] 1 is a graph showing the chromaticity measurement results of the white light emitting devices 100 of the comparative example and examples 1-5. [Figure 4] 1 is a cross-sectional SEM image of a wavelength conversion sintered body 10 of Example 1. [Figure 5] 5A and 5B are graphs showing the luminous efficiency ratio of the white light emitting device 100, where FIG. 5A shows the dependency on the volume ratio of the complex oxides, and FIG. 5B shows the dependency on the plate thickness of the wavelength converting sintered body 10. [Figure 6]10 is a graph showing the chromaticity measurement results of the white light emitting device 100 using the comparative example and examples 6-10. DETAILED DESCRIPTION OF THE INVENTION

[0017] (First embodiment) A first embodiment of the present invention will be described in detail below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant descriptions will be omitted where appropriate. FIG. 1 is a schematic cross-sectional view illustrating the structure of a wavelength-converting sintered body 10 according to this embodiment and a white light-emitting device 100 using the same. As shown in FIG. 1, the white light-emitting device 100 according to this embodiment has the wavelength-converting sintered body 10 bonded to the upper surface of the LED chip 20. In the example shown in FIG. 1, the LED chip 20 is mounted on a reflector 30. The wavelength-converting sintered body 10 also has a sintered phosphor material 11 and fine particles 12 dispersed in the phosphor material 11.

[0018] The wavelength-converting sintered body 10 includes a phosphor material 11 and microparticles 12 made of a composite oxide, and emits yellow light when excited by blue light. The wavelength-converting sintered body 10 is made of ceramic and sintered into a plate shape. The thickness of the plate-shaped wavelength-converting sintered body 10 is preferably in the range of 0.01 mm to 0.5 mm. If the thickness of the wavelength-converting sintered body 10 is thinner than the above range, the mechanical strength of the wavelength-converting sintered body 10 will be insufficient, making it difficult to handle, which is undesirable. If the thickness of the wavelength-converting sintered body 10 is thicker than the above range, the wavelength conversion efficiency will decrease, which is undesirable. Hot isostatic pressing (HIP) can be used to form the wavelength-converting sintered body 10 into a ceramic plate.

[0019] The method for bonding the wavelength-converting sintered body 10 to the LED chip 20 is not limited, and it is possible to use a method of bonding the wavelength-converting sintered body 10 to the semiconductor layer (GaN) or growth substrate (sapphire) of the LED chip 20 by room temperature bonding. Alternatively, an adhesive may be applied between the wavelength-converting sintered body 10 and the LED chip 20 to bond them together.

[0020] The phosphor material 11 is represented by the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y where x+y<3, x<5, x>0, y>0 are satisfied. Such phosphor material 11 is excited by blue light emitted by LED chip 20 and having a peak wavelength in the range of 430 nm to 480 nm, and emits yellow light having a peak wavelength of 530 nm to 580 nm. For simplicity, FIG. 1 illustrates an example in which a portion of phosphor material 11 is circled, but in fact most of the volume of wavelength-converting sintered body 10 is made up of phosphor material 11, and fine particles 12 are dispersed in continuous phosphor material 11.

[0021] The particles 12 are composed of a composite oxide of Ba, Si, and Al, and are particles that scatter light when dispersed in the phosphor material 11. Preferably, the particles 12 are composited in the phosphor material 11 and have a general formula of BaAl2Si z O 2z+4 (where z=1, 2, 3...). The particles 12 are formed by precipitating excess Ba, Si, and Al contained in the raw material as a composite oxide when sintering the phosphor material 11. There is no particular limitation on the method for precipitating the composite oxide as the particles 12. For example, a compound represented by the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y For example, the amount of raw materials Ba, Si, and Al is increased to about 1.01 to 1.06 times the stoichiometric ratio for sintering the phosphor material 11 expressed as x+y<3, x<5, x>0, and y>0.

[0022] Furthermore, the particles 12 preferably have an average particle size in the range of 0.1 μm to 5 μm. If the average particle size of the particles 12 is smaller than the above range, light scattering due to the difference in refractive index at the interface between the particles 12 and the phosphor material 11 is unlikely to occur, which is undesirable. If the average particle size of the particles 12 is larger than the above range, light reaching the particles 12 is blocked, which is undesirable as it reduces the luminous efficiency of the white light-emitting element 100.

[0023] The composite oxide microparticles 12 contained in the wavelength converting sintered body 10 preferably have a volume percentage content of 1% to 5%. If the volume percentage of the microparticles 12 is smaller than the above range, light scattering by the microparticles 12 is unlikely to occur, which is undesirable. On the other hand, if the volume percentage of the microparticles 12 is larger than the above range, the light that reaches the microparticles 12 is blocked, which is undesirable as it reduces the luminous efficiency of the white light emitting device 100.

[0024] The LED chip 20 is a semiconductor light-emitting element that emits blue light and corresponds to a light-emitting diode in the present invention. The LED chip 20 has an anode electrode (not shown) and a cathode electrode (not shown). When a voltage is applied to both electrodes, a current is injected and the LED chip 20 emits blue light. The LED chip 20 has a structure formed by stacking multiple semiconductor layers and has an internal light-emitting layer. The semiconductor material that constitutes the LED chip 20 is not limited, but a GaN-based semiconductor material with a band gap that allows it to emit blue light can be used. The structure of the LED chip 20 is also not limited, and it may have a known layer structure such as a growth substrate, cladding layer, current diffusion layer, contact layer, etc.

[0025] The LED chip 20 emits blue light by emitting and recombining current injected into the LED chip 20 in the light-emitting layer. In this embodiment, the blue light emitted by the LED chip 20 has a peak wavelength in the range of 430 nm to 480 nm. The semiconductor material constituting the light-emitting layer of the LED chip 20 is not limited, but InGaN can be used as an example. The light-emitting layer may also have a known layer structure such as a quantum well structure, a multiple quantum well structure, or an overflow suppression layer.

[0026] The reflector 30 is a member that mounts the LED chip 20 and reflects light from the LED chip 20 and the wavelength converting sintered body 10. The specific configuration of the reflector 30 is not limited, and it may be a resin plate with a reflective film formed on its surface, or a metal with recesses formed by processing. While FIG. 1 shows an example in which the LED chip 20 is mounted on the reflector 30, the LED chip 20 may be directly mounted on a wiring substrate or a submount or other member. When a submount substrate is used, it is preferable to use a material with good thermal conductivity, such as a single-crystal substrate such as AlN or Si, or a ceramic substrate. Furthermore, electrodes and wiring for supplying current to the LED chip 20 may be formed on the reflector 30 or the wiring substrate.

[0027] In the white light-emitting element 100 shown in FIG. 1, blue light (primary light) emitted from the light-emitting layer of the LED chip 20 enters the wavelength-converting sintered body 10, and the phosphor material 11 converts a portion of the blue light into yellow light (secondary light). The blue light that has not been wavelength-converted passes through the wavelength-converting sintered body 10 and is extracted from the top surface. The wavelength-converted yellow light spreads isotropically within the wavelength-converting sintered body 10 and travels not only upward but also sideways and downward. The yellow light that enters the composite oxide microparticles 12 is scattered due to the difference in refractive index with the phosphor material 11, increasing the amount of light traveling upward. This improves the luminous efficiency of the white light extracted upward from the white light-emitting element 10 and reduces color unevenness.

[0028] (Comparative Example) The wavelength-converting sintered body 10 according to the comparative example has the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y The ceramic is composed of a BS-YAG phosphor, which satisfies the following conditions: x + y < 3, x < 5, x > 0, y > 0. First, powdered raw materials were prepared: Y2O3 (99.9% by Kojundo Chemical Laboratory Co., Ltd.), CeO2 (99.99% by Kojundo Chemical Laboratory Co., Ltd.), BaCO3 (99.9% by Kanto Chemical Co., Ltd.), α-Al2O3 (99.99% by Kojundo Chemical Laboratory Co., Ltd.), and SiO2 (SE-8, 99.9% by Tokuyama Corporation). Each powdered raw material was then weighed to a molar ratio of Y:Ce:Ba:Al:Si = 2.91:0.05:0.04:4.96:0.04, and mixed and pulverized in a mortar to obtain a mixed powder.

[0029] The resulting mixed powder was filled into a mold with a thickness of 1 mm and a diameter of 15 mm, and pressure was applied to obtain a primary compact. The primary compact was then compression-molded using CIP at a molding pressure of 250 MPa to obtain a secondary compact. The secondary compact was then placed in an alumina crucible (Nikkato Corporation, SSA-S B1) and heated in air at 1550°C for 4 hours. After cooling, the secondary compact was further pressure-sintered using HIP (Kobe Steel, Ltd., ultra-high-pressure HIP) under conditions of 100 MPa and 1550°C in an Ar atmosphere for 2 hours to obtain a plate-shaped, translucent ceramic wavelength-converting sintered body 10. The resulting wavelength-converting sintered body 10 was polished to a thickness of 0.2 mm, cut into a square of 1 mm, and room-temperature bonded to an LED chip 20 to obtain a comparative white light-emitting device 100.

[0030] Example 1 The wavelength-converting sintered body 10 according to Example 1 is a compound represented by the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce yThe ceramic is formed by dispersing composite oxide particles 12 made of BaAl2Si2O8 in a BS-YAG phosphor that satisfies the following conditions: x+y<3, x<5, x>0, y>0. A wavelength-converting sintered body 10 was obtained using the same manufacturing method as in the comparative example, except that the molar ratio of the powder raw materials was set to Y:Ce:Ba:Al:Si=2.91:0.05:0.07:5.02:0.10, and thus a white light-emitting device 100 of Example 1 was obtained.

[0031] Example 2 The wavelength-converting sintered body 10 according to Example 2 is a compound represented by the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y The ceramic is formed by dispersing composite oxide particles 12 made of BaAl2Si2O8 in a BS-YAG phosphor that satisfies the following conditions: x+y<3, x<5, x>0, y>0. A wavelength-converting sintered body 10 was obtained using the same manufacturing method as in Example 1, except that the molar ratio of the powder raw materials was Y:Ce:Ba:Al:Si=2.91:0.05:0.05:4.98:0.06, and thus a white light-emitting device 100 of Example 2 was obtained.

[0032] Example 3 The wavelength-converting sintered body 10 according to Example 3 is a compound represented by the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y The ceramic is formed by dispersing composite oxide particles 12 made of BaAl2Si2O8 in a BS-YAG phosphor that satisfies the following conditions: x+y<3, x<5, x>0, y>0. A wavelength-converting sintered body 10 was obtained using the same manufacturing method as in Example 1, except that the molar ratio of the powder raw materials was Y:Ce:Ba:Al:Si=2.91:0.05:0.09:5.06:0.14, and a white light-emitting device 100 of Example 3 was obtained.

[0033] Example 4 A white light emitting device 100 of Example 4 was obtained in the same manner as in Example 1, except that the wavelength converting sintered body 10 was polished to a thickness of 0.05 mm.

[0034] Example 5 The white light emitting device 100 of Example 5 was obtained in the same manner as in Example 1, except that the wavelength converting sintered body 10 was polished to a thickness of 0.5 mm.

[0035] FIG. 2 is a schematic diagram illustrating a method for measuring the luminous color and luminous intensity of the white light-emitting element 100. As shown in FIG. 2, in this embodiment, a measuring device (MCPD1000 manufactured by Otsuka Electronics Co., Ltd.) having a light-receiving unit 40 and a spectrometer 50 was used to measure the chromaticity and luminous intensity of the white light-emitting element 100 placed on a stage ST. The white light-emitting element 100 was positioned with the LED chip 20 facing the stage ST, and the wavelength-converting sintered body 10 facing the light-receiving unit 40. For the measurement, a current of 500 mA was applied to the white light-emitting element 100 for 10 minutes, and the light-receiving unit 40 was placed 5 cm above the center of the wavelength-converting sintered body 10. When the luminous intensity of the comparative example was taken as 1, the relative luminous intensities were 1.1 for Example 1, 1.05 for Example 2, 1.00 for Example 3, 1.05 for Example 4, and 1.00 for Example 5.

[0036] Fig. 3 is a graph showing the chromaticity measurement results of the white light-emitting elements 100 of the comparative example and Examples 1-5. The measurement device and method shown in Fig. 2 were used for measuring the chromaticity. The solid line frame shown in the graph indicates the chromaticity range of a vehicle headlamp. All of Examples 1-5 were within the chromaticity range of a vehicle headlamp.

[0037] FIG. 4 is a cross-sectional SEM image of the wavelength-converting sintered body 10 of Example 1. The white areas in FIG. 4 are phosphor material 11 made of BS-YAG, and the gray areas dispersed in the phosphor material 11 are particles 12 made of a composite oxide of Ba, Si, and Al. Thirty particles 12 were randomly selected from this cross-sectional SEM image, and their particle sizes were measured. The particle sizes were found to be between 0.1 μm and 5 μm. Furthermore, analysis of the particles 12 using an energy-dispersive X-ray spectroscopy (EDX) device revealed that the particles 12 were a composite oxide made of BaAl2Si2O8. Furthermore, the molar and weight ratios of the phosphor material 11 made of BS-YAG and the particles 12 made of BaAl2Si2O8 were calculated from the EDX analysis, and the volume percentage of the particles 12 in the wavelength-converting sintered body 10 was calculated based on the specific gravity of BaAl2Si2O8, which is 3.37.

[0038] Table 1 shows the results of the molar ratio, weight ratio, volume ratio, plate thickness, luminous efficiency ratio, and chromaticity evaluation of the particles 12 in the comparative example and Examples 1-5. [Table 1]

[0039] 5A and 5B are graphs showing the luminous efficiency ratio of the white light emitting element 100, where FIG. 5A shows the dependency on the volume ratio of the complex oxides, and FIG. 5B shows the dependency on the plate thickness of the wavelength converting sintered body 10.

[0040] The horizontal axis of Fig. 5(a) shows the volume ratio of the microparticles 12 in the wavelength converting sintered body 10, and the vertical axis shows the relative luminous efficiency when the luminous intensity of the comparative example is set to 1. In Fig. 5(a), the measurement results of Examples 1-3 are plotted to form an approximate curve, and the luminous efficiency is improved compared to BS-YAG alone when the volume percentage is in the range of 1% to 5%.

[0041] In addition, the horizontal axis of Fig. 5(b) represents the plate thickness of the polished wavelength conversion sintered body 10, and the vertical axis represents the relative luminous efficiency when the luminous intensity of the comparative example is set to 1. In Fig. 5(b), the measurement results of Examples 1, 4, and 5 are plotted to form an approximate curve, and the luminous efficiency is improved compared to BS-YAG alone in the plate thickness range of 0.01 mm or more and 0.5 mm or less.

[0042] Example 6 The wavelength-converting sintered body 10 according to Example 6 was formed by 3-x-y Ba x Al 5-x Si x O 12 :Ce y The ceramic is formed by dispersing composite oxide particles 12 made of BaAlSiO in a BS-YAG phosphor that satisfies the following conditions: x+y<3, x<5, x>0, y>0. A wavelength-converting sintered body 10 was obtained using the same manufacturing method as in Example 1, except that the molar ratio of the powder raw materials was Y:Ce:Ba:Al:Si=2.91:0.05:0.07:5.02:0.07, and a white light-emitting device 100 of Example 6 was obtained.

[0043] Example 7 The wavelength-converting sintered body 10 according to Example 7 was a compound represented by the general formula Y 3-x-y Ba x Al 5-x Si x O 12 :Ce y The ceramic is formed by dispersing composite oxide particles 12 made of BaAlSiO in a BS-YAG phosphor that satisfies the following conditions: x+y<3, x<5, x>0, y>0. A wavelength-converting sintered body 10 was obtained using the same manufacturing method as in Example 1, except that the molar ratio of the powder raw materials was Y:Ce:Ba:Al:Si=2.91:0.05:0.05:4.98:0.05, and thus a white light-emitting device 100 of Example 7 was obtained.

[0044] Example 8 The wavelength-converting sintered body 10 according to Example 8 was formed by 3-x-y Ba x Al 5-x Si x O 12:Ce y The ceramic is formed by dispersing composite oxide particles 12 made of BaAlSiO in a BS-YAG phosphor that satisfies the following conditions: x+y<3, x<5, x>0, y>0. A wavelength-converting sintered body 10 was obtained using the same manufacturing method as in Example 1, except that the molar ratio of the powder raw materials was Y:Ce:Ba:Al:Si=2.91:0.05:0.10:5.08:0.10, and thus a white light-emitting device 100 of Example 8 was obtained.

[0045] Example 9 The white light emitting device 100 of Example 9 was obtained in the same manner as in Example 6, except that the wavelength converting sintered body 10 was polished to a thickness of 0.05 mm.

[0046] Example 10 The white light emitting device 100 of Example 10 was obtained in the same manner as in Example 6, except that the wavelength converting sintered body 10 was polished to a thickness of 0.5 mm.

[0047] As in Examples 1-5, the chromaticity and luminous intensity of the white light-emitting devices 100 of Examples 6-10 were measured using the measuring device shown in Fig. 2. The relative luminous intensity, assuming that the luminous intensity of the comparative example was 1, was 1.1 for Example 6, 1.05 for Example 7, 1.00 for Example 8, 1.05 for Example 9, and 1.00 for Example 10.

[0048] Fig. 6 is a graph showing the chromaticity measurement results of the white light-emitting element 100 using the comparative example and examples 6-10. The measurement device and measurement method shown in Fig. 2 were used for measuring the chromaticity. The solid line frame shown in the graph indicates the chromaticity range of the vehicle headlamp. All of examples 6-10 were within the chromaticity range of the vehicle headlamp.

[0049] Similarly to Examples 1-5, cross-sectional SEM images of the wavelength-converting sintered bodies 10 of Examples 6-10 were taken (not shown). Thirty particles 12 were randomly selected from the cross-sectional SEM images, and the particle sizes were measured. These measurements were found to be between 0.1 μm and 5 μm. EDX analysis revealed that the particles 12 of Examples 6-10 were composite oxides made of BaAl2SiO6. From the EDX analysis, the molar ratio and weight ratio of the phosphor material 11 made of BS-YAG and the particles 12 made of BaAl2SiO8 were calculated, and the volume percentage of the particles 12 in the wavelength-converting sintered body 10 was calculated based on the specific gravity of BaAl2SiO8, which is 2.38.

[0050] Table 2 shows the results of the molar ratio, weight ratio, volume ratio, plate thickness, luminous efficiency ratio, and chromaticity evaluation of the particles 12 in the comparative example and Examples 6-10. [Table 2]

[0051] As described above, in the wavelength conversion sintered body 10 and white light emitting element 100 of the present invention, the particles 12 which are a composite oxide of Ba, Si, and Al are dispersed in the phosphor material 11, so that the secondary light wavelength-converted by the phosphor material 11 is scattered by the particles 12, increasing the proportion of yellow light extracted from the surface, thereby improving the luminous efficiency of white light and reducing the chromaticity difference with respect to the normal angle of incidence.

[0052] (Second embodiment) Next, a second embodiment of the present invention will be described. Details that overlap with the first embodiment will not be described. In the first embodiment, an example was shown in which a plate-shaped wavelength-converting sintered body 10 was bonded to an LED chip 20 at room temperature, but the plate-shaped wavelength-converting sintered body 10 may be disposed at a distance from the LED chip 20.

[0053] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0054] 100...White light emitting element 10... Wavelength conversion sintered body 11...Phosphor material 12...Fine particles 20...LED chip 30…Reflector 40...Light receiving section 50...Spectrometer

Claims

1. General formula Y ３－ｘ－ｙ Ba ｘ Al ５－ｘ Si ｘ O １２ : Ce ｙ (where x+y<3, x<5, x>0, y>0) and a phosphor material represented by having fine particles dispersed in the phosphor material, The wavelength-converting sintered body is characterized in that the fine particles are a composite oxide of Ba, Si, and Al.

2. 2. The wavelength conversion sintered body according to claim 1, The wavelength conversion sintered body is characterized in that the fine particles are composited in the phosphor material.

3. 2. The wavelength conversion sintered body according to claim 1, The composite oxide has the general formula BaAl ２ Si ｚ O ２ｚ＋４ (where z=1, 2, 3, . . . ).

4. 2. The wavelength conversion sintered body according to claim 1, The wavelength-converting sintered body is characterized in that the fine particles have an average particle size in the range of 0.1 μm to 5 μm.

5. 2. The wavelength conversion sintered body according to claim 1, The wavelength-converting sintered body is characterized in that the composite oxide is contained in an amount of 1% to 5% by volume.

6. 2. The wavelength conversion sintered body according to claim 1, 1. A wavelength-converting sintered body formed into a plate shape and having a thickness in the range of 0.01 mm to 0.5 mm.

7. A wavelength-converting sintered body according to any one of claims 1 to 6; A white light emitting element characterized by having a light emitting diode that emits blue light attached thereto.

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