Composite ceramics, phosphor element, laser lighting device, and method for manufacturing composite ceramics

Abstract

The composite ceramic (1) comprises a sintered body containing a garnet phosphor component (2), a nitride phosphor component (3), and a matrix component (4) comprising at least one selected from the group consisting of MgO and Al2O3. The content of the matrix component is from 31 wt% to 95 wt% of the total components. The matrix component is sintered surrounding the garnet phosphor component and the nitride phosphor component.

Description

[Technical Field]

[0001] The present disclosure relates to a composite ceramic containing a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component, a phosphor element and a laser lighting device including the composite ceramic, and a method for manufacturing the composite ceramic. [Background technology]

[0002] Laser lighting devices are more energy-efficient, compact, and brighter than other lighting devices, and are already being put to practical use as lighting devices for projectors and automobile headlights.In addition, in the home lighting market, laser lighting devices are expected to replace existing LED (light-emitting diode) lighting devices and fluorescent lights, and the laser lighting market is expected to expand rapidly in the future.

[0003] However, composite ceramics that are being put to practical use as phosphors for such laser lighting devices use a YAG (yttrium aluminum garnet) phosphor as the phosphor component, which converts blue light to yellow. For example, Patent Document 1 discloses a ceramic composite that contains a phosphor phase made of YAG containing Ce, a matrix phase made of at least one of Al2O3 and AlN, and impurities in a predetermined range of amounts.

[0004] Meanwhile, in recent years, composite ceramics containing red phosphors that emit red fluorescence have also been developed. For example, Patent Document 2 discloses a composite ceramic in the form of a phosphor molded body produced by sintering a mixture of AlN powder and phosphor powder by spark plasma sintering, melting the AlN powder, and then cooling it. Note that the red phosphor here refers to a phosphor that emits red to orange light. Patent Document 2 also discloses that a nitride phosphor may be used for the phosphor powder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-012215 [Patent Document 2] Japanese Patent Publication No. 2016-180076 Summary of the Invention [Problem to be solved by the invention]

[0006] However, to achieve dense ceramics, the raw materials must be sintered at high temperatures, and high temperatures during sintering can easily cause the properties of nitride-based phosphors in particular to deteriorate. Sintering composite ceramics that use nitride-based phosphors or AlN, which are difficult to sinter, is difficult in the first place. For this reason, composite ceramics containing red phosphors and suitable for high-power excitation that can withstand laser excitation have not yet been developed.

[0007] One aspect of the present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide a composite ceramic containing a red phosphor for laser illumination that can be manufactured relatively easily, a phosphor element and a laser illumination device that include the same, and a method for manufacturing such a composite ceramic. [Means for solving the problem]

[0008] In order to solve the above problems, a composite ceramic according to one embodiment of the present disclosure is a composite ceramic consisting of a sintered body containing a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component, wherein the matrix component is at least one selected from the group consisting of MgO and Al2O3, the content of the matrix component is in the range of 31 wt% or more and 95 wt% or less of all components, and the matrix component is sintered while surrounding the garnet-based phosphor component and the nitride-based phosphor component.

[0009] In order to solve the above problems, a phosphor element according to one aspect of the present disclosure includes the composite ceramic according to one aspect of the present disclosure and a substrate that fixes the composite ceramic.

[0010] In order to solve the above problems, a laser illumination device according to an aspect of the present disclosure includes: a phosphor element according to an aspect of the present disclosure; a laser light source that irradiates excitation light onto the composite ceramic in the phosphor element; and a focusing member that focuses light output from the composite ceramic in the phosphor element.

[0011] In order to solve the above problems, a method for manufacturing a composite ceramic according to one embodiment of the present disclosure includes a mixing step of mixing a first raw material powder including a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component; a first raw material powder containing step of containing the mixed first raw material powder in a molding die; a sintering step of sintering the first raw material powder contained in the molding die by a spark plasma sintering method or a hot press method; and a demolding step of removing the sintered body obtained in the sintering step from the molding die. [Effects of the Invention]

[0012] According to one aspect of the present disclosure, it is possible to provide a composite ceramic containing a red phosphor for laser illumination that can be manufactured relatively easily, a phosphor element and a laser illumination device that include the same, and a method for manufacturing such a composite ceramic. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing an example of the structure of a composite ceramic according to a first embodiment. [Figure 2] 1 is a flowchart showing an example of a method for producing the composite ceramic according to the first embodiment. [Figure 3] FIG. 4 is a cross-sectional view showing an example of the structure of a composite ceramic according to a second embodiment. [Figure 4]FIG. 10 is a cross-sectional view showing an example of the structure of a composite ceramic according to a third embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing an example of the structure of a composite ceramic according to a fourth embodiment. [Figure 6] FIG. 10 is a diagram showing a composite ceramic according to a fifth embodiment, in which an anti-reflection coating film is provided on one of the main surfaces. [Figure 7] FIG. 10 is a cross-sectional view showing an example of a phosphor element according to a fifth embodiment. [Figure 8] 8 is a flowchart showing an example of a method for manufacturing the phosphor element shown in FIG. [Figure 9] FIG. 13 is a cross-sectional view showing an example of a laser illuminator according to a sixth embodiment. [Figure 10] FIG. 2 is a ternary diagram showing the contents of nitride-based phosphor components, matrix components, and garnet-based phosphor components in Examples 1 to 5 and Comparative Examples 1 to 5. [Figure 11] FIG. 1 is a diagram showing an XRD pattern of the composite ceramic obtained in Example 1. [Figure 12] FIG. 2 is a graph showing the laser power dependence of the fluorescent power of the composite ceramic obtained in Example 1. [Figure 13] FIG. 2 is a diagram showing the fluorescence spectrum of the composite ceramic obtained in Example 1. [Figure 14] FIG. 2 is a diagram showing an example of an SEM image of the composite ceramic obtained in Example 2. [Figure 15] FIG. 2 is a diagram showing an XRD pattern of the composite ceramic obtained in Example 2. [Figure 16] FIG. 10 is a graph showing the laser power dependence of the fluorescent power of the composite ceramic obtained in Example 2. [Figure 17] FIG. 1 is a diagram showing the fluorescence spectrum of the composite ceramic obtained in Example 2. [Figure 18] FIG. 10 is a graph showing the laser power dependence of the fluorescent power of the composite ceramic obtained in Example 3. [Figure 19]FIG. 10 is a diagram showing the fluorescence spectrum of the composite ceramic obtained in Example 3. [Figure 20] FIG. 10 is a graph showing the laser power dependence of the fluorescent power of the composite ceramic obtained in Comparative Example 1. [Figure 21] FIG. 1 is a diagram showing the fluorescence spectrum of the composite ceramic obtained in Comparative Example 1. [Figure 22] FIG. 2 is a ternary diagram showing the contents of nitride-based phosphor components, matrix components, and garnet-based phosphor components in Examples 6 and 7 and Comparative Examples 6 to 9. [Figure 23] FIG. 10 is a graph showing the laser power dependence of the fluorescent power of the composite ceramic obtained in Example 6. [Figure 24] FIG. 10 is a diagram showing the fluorescence spectrum of the composite ceramic obtained in Example 6. [Figure 25] FIG. 10 is a graph showing the laser power dependence of the fluorescent power of the composite ceramics obtained in Examples 6 and 7. [Figure 26] FIG. 1 is a ternary diagram showing the contents of nitride-based phosphor components, matrix components, and garnet-based phosphor components in Examples 8 to 12 and Comparative Examples 10 to 13. [Figure 27] FIG. 2 is a ternary diagram showing the contents of nitride-based phosphor components, matrix components, and garnet-based phosphor components in Examples 13 to 18 and Comparative Examples 14 to 17. [Figure 28] FIG. 10 is a graph showing the fluorescent power characteristics of the composite ceramic of Reference Example 12 before and after annealing treatment. [Figure 29] FIG. 10 is a graph showing the fluorescent power characteristics before and after annealing treatment in the composite ceramic of Reference Example 13. [Figure 30] FIG. 10 is a diagram showing the excitation light power resistance of a phosphor element made from the composite ceramic of Example 18. [Figure 31] FIG. 10 is a diagram showing the characteristics of fluorescent power due to continuous irradiation with laser light. DETAILED DESCRIPTION OF THE INVENTION

[0014] Embodiments of the present disclosure are described below. For ease of explanation, components having the same functions as those previously described will be denoted by the same reference numerals, and their description will not be repeated. In addition, in the second and subsequent embodiments, differences from the previously described embodiments will be described. It goes without saying that, even if there is no particular explanation, the second and subsequent embodiments can be modified in the same manner as the previously described embodiments. In addition, hereinafter, the expression "A to B" for two numbers A and B means "greater than or equal to A and less than or equal to B," unless otherwise specified.

[0015] [Embodiment 1] FIG. 1 is a cross-sectional view showing an example of the structure of a composite ceramic 1 according to this embodiment.

[0016] The composite ceramic 1 according to this embodiment is a multi-wavelength luminescent ceramic composite made of a sintered body containing a phosphor component having two or more kinds of luminescent wavelengths and a matrix component.

[0017] The composite ceramic 1 shown in FIG. 1 includes a garnet-based phosphor component 2, a nitride-based phosphor component 3, and a matrix component 4, and has a structure in which the matrix component 4 surrounds and sinters the garnet-based phosphor component 2 and the nitride-based phosphor component 3.

[0018] Therefore, as shown in Figure 1, the composite ceramic 1 has a sea-island structure in which the garnet-based phosphor component 2 and the nitride-based phosphor component 3 are mixed in island-like form within the matrix component 4. In other words, the composite ceramic 1 has a structure in which the garnet-based phosphor component 2 and the nitride-based phosphor component 3 are dispersed in island-like form within the matrix component 4, which appears to be a relatively continuous sea. The matrix component 4 is filled between the garnet-based phosphor component 2 and the nitride-based phosphor component 3.

[0019] The garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4 are fixed to one another.

[0020] The composite ceramic 1 has at least three phases: a first phosphor phase consisting of a garnet-based phosphor component 2, a second phosphor phase consisting of a nitride-based phosphor component 3, and a matrix phase consisting of a matrix component 4.

[0021] Therefore, composite ceramic 1 has a structure in which at least the above three phases are mixed and adjacent phases are bonded together. Here, a structure in which at least the above three phases are mixed and adjacent phases are bonded together refers to a structure in which the above three phases are not dissolved in a solid, but are separated into their respective phase regions in the solid, and adjacent phases are bonded together. This also includes cases in which sintering aids or impurities are present at grain boundaries. Alternatively, even if there is a slight altered phase or molten phase between particles, a composite ceramic is considered to be a material that basically has a solid three-phase structure.

[0022] Among the three or more phases, a solid solution in which at least adjacent phases are dissolved in each other is excluded from the composite ceramics 1. Also excluded from the composite ceramics 1 are a bonded material in which three or more phases are simply bonded directly, and a composition in which at least the three phases are solidified with at least one of inorganic glass and an organic binder.

[0023] (Garnet-based phosphor component 2) In the present disclosure, the garnet-based phosphor component 2 refers to a phosphor having a garnet crystal structure. The garnet-based phosphor component 2 is a phosphor with a large refractive index and excellent fluorescent properties, and emits yellow-to-green yellowish fluorescence when exposed to blue excitation light, for example. Furthermore, the excitation light that does not contribute to the excitation is scattered and transmitted. Therefore, the garnet-based phosphor component 2 outputs blue scattered light and yellowish fluorescence.

[0024] The garnet-based phosphor component 2 has excellent heat resistance, and can suppress deterioration even when irradiated with high-power excitation light LD (laser diode), for example.

[0025] For example, a YAG (yttrium aluminum garnet) phosphor can be used as the garnet phosphor component 2. The YAG phosphor refers to a phosphor that can be attributed to the crystal structure of a YAG phosphor.

[0026] Examples of YAG phosphors include (Ce, Y)3Al5O 12 , (Ce,Lu)3Al5O 12 , (Ce,Lu,Y)3Al5O 12 , (Ce,Lu,Y)3(Al,Ga)5O 12 The composite ceramic 1 can be at least one selected from the group consisting of: When the composite ceramic 1 contains the YAG-based phosphor as the garnet-based phosphor component 2, it is possible to easily realize a composite ceramic 1 that emits yellow to green fluorescence. Furthermore, when the composite ceramic 1 contains the YAG-based phosphor as the garnet-based phosphor component 2, it is possible to obtain a composite ceramic 1 with even more excellent fluorescent properties.

[0027] (Nitride-based phosphor component 3) In the present disclosure, the nitride-based phosphor component 3 refers to a phosphor containing nitrogen. Specific examples of the nitride-based phosphor component 3 include at least one phosphor selected from the group consisting of nitride phosphors and oxynitride phosphors.

[0028] The nitride-based phosphor component 3 is a red-based phosphor with excellent fluorescent properties that emits red-based fluorescence in the red to orange range; for example, it emits red-based fluorescence when exposed to blue excitation light. Furthermore, the excitation light that does not contribute to excitation is scattered and transmitted. Therefore, the nitride-based phosphor component 3 outputs blue scattered light and red-based fluorescence. By including the nitride-based phosphor component 3 in the composite ceramic 1, a ternary composite ceramic that emits incandescent-colored fluorescence can be obtained. Furthermore, by including the nitride-based phosphor component 3 in the composite ceramic 1, a composite ceramic 1 with even more excellent fluorescent properties can be obtained.

[0029] Examples of the nitride phosphor component 3 include at least one nitride phosphor selected from the group consisting of Sr2Si5N8, (Sr,Ba)2Si5N8, and (Ca,Sr,Ba)2Si5N8, each activated with at least one of Eu and Ce. Hereinafter, for convenience of explanation, these nitride phosphors may be referred to as nitride phosphor (A). Eu and Ce are activators and are doped into the crystal. Thus, examples of the nitride-based phosphor component 3 include nitride phosphors (A) such as Eu:Sr2Si5N8, Eu:(Sr,Ba)2Si5N8, Eu:(Ca,Sr,Ba)2Si5N8, Ce:Sr2Si5N8, Ce:(Sr,Ba)2Si5N8, Ce:(Ca,Sr,Ba)Si5N8, (Eu,Ce):Sr2Si5N8, (Eu,Ce):(Sr,Ba)2Si5N8, and (Eu,Ce):(Ca,Sr,Ba)2Si5N8.

[0030] When the composite ceramic 1 contains such alkaline earth silicon nitride as the nitride-based phosphor component 3, it is possible to produce a composite ceramic 1 that emits stable reddish fluorescence.

[0031] In these nitride phosphors (A), at least one of Si and N in the above composition formula may be substituted. When Si is substituted, Si is substituted with Al. When N is substituted, N is substituted with O.

[0032] Therefore, the nitride phosphor component 3 may be a nitride phosphor in which part of Si in Sr2Si5N8, (Sr,Ba)2Si5N8, or (Ca,Sr,Ba)2Si5N8 is substituted with Al, or an oxynitride phosphor in which part of N is substituted with O. It may also be an oxynitride phosphor in which part of Si is substituted with Al and part of N is substituted with O. Examples include (Sr,Ba)2(Si,Al)5N8 and (Sr,Ba)2(Si,Al)5(N,O)8 activated with at least one element of Eu and Ce.

[0033] By including at least one of such nitride phosphors and oxynitride phosphors as the nitride-based phosphor component 3 in the composite ceramic 1, a more reliable composite ceramic 1 can be realized.

[0034] Alternatively, the nitride phosphor component 3 may be at least one nitride phosphor selected from the group consisting of CaAlSiN3 and (Ca,Sr)AlSiN3, each activated with at least one of Eu and Ce. Hereinafter, for convenience of explanation, these nitride phosphors may be referred to as nitride phosphor (B). Eu and Ce are activators and are doped into the crystal. Thus, the nitride phosphor component 3 may be, for example, nitride phosphor (B) such as Eu:CaAlSiN3, Eu:(Ca,Sr)AlSiN3, Ce:CaAlSiN3, Ce:(Ca,Sr)AlSiN3, (Eu,Ce):CaAlSiN3, or (Eu,Ce):(Ca,Sr)AlSiN3.

[0035] Furthermore, as the nitride-based phosphor component 3, in addition to the nitride phosphor (A) and the nitride phosphor (B), for example, Ce-activated (La, Y) 3 Si 6 N 11 For example, the nitride-based phosphor component 3 may be (La)3Si6N activated with at least one element of Eu and Ce. 11、 (La,Y)3Si6N 11、 (La, Y, Lu)3Si6N 11 The nitride-based phosphor component 3 may be at least one selected from the group consisting of (La)3Si6N 11、 (La,Y)3Si6N 11、 (La, Y, Lu)3Si6N 11 At least one nitride-based phosphor component ("La3Si6N 11These nitride phosphors are also called "nitride phosphor components" (also called "nitride phosphor components"), and are nitride phosphor components activated with at least one of Eu and Ce. Hereinafter, for convenience of explanation, these nitride phosphors may be referred to as "nitride phosphor (C)." Eu and Ce are activators and are doped into the crystal.

[0036] These nitride phosphors (A), (B) and (C), as well as nitride phosphors other than these nitride phosphors (A) and (B), may be used separately or may be used in combination as long as they do not form a solid solution or react with each other.

[0037] (Matrix component 4) The matrix component 4 is at least one selected from the group consisting of MgO (magnesium oxide) and Al2O3 (aluminum oxide). The matrix component 4 may be MgO, Al2O3, or a mixture of MgO and Al2O3.

[0038] The composite ceramic 1 according to this embodiment has a thermal conductivity of 0.5 kW / cm 2 The composite ceramic 1 according to this embodiment has the above-mentioned resistance to excitation light power. As described above, the composite ceramic 1 according to this embodiment is a composite ceramic for low color temperatures that has high fluorescence power relative to excitation light power, can withstand laser excitation, and has high resistance to excitation light power. Therefore, according to this embodiment, it is possible to realize a practical phosphor element for lasers that does not saturate fluorescence even at relatively high power.

[0039] The higher the pumping light power tolerance, the more the laser can withstand high-power laser pumping, so the upper limit is not particularly limited. However, based on the pumping light power tolerance (laser power tolerance) of laser light sources or various optical components that can be actually used, the upper limit of the pumping light power tolerance is set to 100 kW / cm. 2 Therefore, the excitation light power tolerance of the composite ceramic 1 according to this embodiment is preferably 0.5 kW / cm 2More preferably, 1 kW / cm 2 More preferably, 3 kW / cm 2 or more, and 100 kW / cm 2 It is desirable that the value is within the following range.

[0040] In this disclosure, the pumping light power tolerance is defined as 1 cm 2 It indicates the value at which the fluorescence power saturates relative to the excitation light power (specifically, laser excitation light power) per unit of wavelength. The excitation light power tolerance can be measured using a phosphor evaluation device equipped with a laser light source, an integrating sphere, and a spectrometer.

[0041] (Content of each component in composite ceramic 1) The content of the matrix component 4 in the composite ceramic 1 is in the range of 31 wt % or more and 95 wt % or less of all the components in the composite ceramic 1.

[0042] Thus, the composite ceramic 1 according to this embodiment is a composite ceramic consisting of a sintered body containing a garnet-based phosphor component 2, a nitride-based phosphor component 3, and a matrix component 4, wherein the matrix component 4 is at least one selected from the group consisting of MgO and Al2O3, the content of the matrix component 4 is in the range of 31 wt% or more and 95 wt% or less of all components, and the matrix component 4 is sintered surrounding the garnet-based phosphor component 2 and the nitride-based phosphor component 3.

[0043] According to this embodiment, it is possible to provide a composite ceramic 1 containing a red phosphor for laser illumination, which can be manufactured relatively easily.

[0044] According to the studies of the present inventors, the pumping light power resistance can be further improved by increasing the content of the matrix component 4 in the composite ceramic 1. Therefore, it is preferable that the content of the matrix component 4 in the composite ceramic 1 is set closer to the upper limit of the above range. For this reason, the content of the matrix component 4 in the composite ceramic 1 is more preferably 45 wt% or more, and even more preferably 60 wt% or more.

[0045] As described above, the content of the matrix component 4 in the composite ceramic 1 is within the range of 31 wt% to 95 wt% of all components, and more preferably within the range of 31 wt% to 90 wt% of all components.

[0046] Therefore, the total content of the garnet-based phosphor component 2 and the nitride-based phosphor component 3 in the composite ceramic 1 is preferably within the range of 5 wt % to 69 wt % of all the components in the composite ceramic 1 .

[0047] As a result, as described above, it is possible to provide a composite ceramic 1 containing a red phosphor for laser illumination, which can be manufactured relatively easily. Furthermore, according to the above configuration, it is possible to obtain a composite ceramic 1 having a structure in which the matrix component 4 surrounds and sinters the garnet-based phosphor component 2 and the nitride-based phosphor component 3, and adjacent phases are fixed together.

[0048] The respective contents of the garnet-based phosphor component 2 and the nitride-based phosphor component 3 in the composite ceramic 1 are not particularly limited, and may be appropriately set so that the total content thereof falls within the above range. By appropriately adjusting the respective contents of the garnet-based phosphor component 2 and the nitride-based phosphor component 3 according to the types of the garnet-based phosphor component 2 and the nitride-based phosphor component 3, a desired emission spectrum can be obtained.

[0049] For example, as described above, the garnet-based phosphor component 2 emits yellow or green fluorescence when exposed to blue excitation light. As described above, the nitride-based phosphor component 3 emits reddish fluorescence when exposed to blue excitation light. These phosphors also scatter and transmit the excitation light that did not contribute to the excitation. Therefore, when blue excitation light is irradiated onto the composite ceramic 1, the composite ceramic 1 outputs reddish warm white light that is a mixture of blue scattered light, yellowish fluorescence, and reddish fluorescence.

[0050] The content of the garnet-based phosphor component 2 in the composite ceramic 1 is preferably within the range of 2 wt% or more and 65 wt% or less of all components in the composite ceramic 1, more preferably within the range of 2 wt% or more and 59 wt% or less, and even more preferably within the range of 4 wt% or more and 59 wt% or less.

[0051] Furthermore, the content of the nitride-based phosphor component 3 in the composite ceramic 1 is preferably within the range of 2 wt% or more and 65 wt% or less of all components in the composite ceramic 1, more preferably within the range of 2 wt% or more and 59 wt% or less, and even more preferably within the range of 4 wt% or more and 59 wt% or less.

[0052] This makes it possible to obtain an incandescent light emission spectrum that also contains red to orange red fluorescence, which is particularly suitable for home lighting devices, lighting devices for projectors, automobile headlights, outdoor lighting, and particularly lighting devices for long-distance lighting.

[0053] However, according to the studies of the present inventors, as the content of the nitride-based phosphor component 3 in the composite ceramic 1 increases, the fluorescent power tends to become saturated with respect to the excitation light power. Therefore, by reducing the content of the nitride-based phosphor component 3 in the composite ceramic 1, it is possible to further improve the resistance to the excitation light power. Therefore, it is preferable that the content of the nitride-based phosphor component 3 in the composite ceramic 1 is set closer to the lower limit within the above range. For this reason, the content of the nitride-based phosphor component 3 in the composite ceramic 1 is more preferably 60 wt% or less, and even more preferably 40 wt% or less.

[0054] Furthermore, in a ternary diagram in which the total content of the nitride-based phosphor component 3, matrix component 4, and garnet-based phosphor component 2 of the composite ceramic 1 is 100 wt%, it is particularly preferable that the respective contents of the nitride-based phosphor component 3, matrix component 4, and garnet-based phosphor component 2 be within the range surrounded by the straight lines connecting points A to D below, as shown, for example, in Figures 10 and 22 below.

[0055] Here, point A indicates the point where the content of the nitride-based phosphor component 3 is 59 wt%, the content of the matrix component 4 is 31 wt%, and the content of the garnet-based phosphor component 2 is 10 wt%.

[0056] Point B indicates the point where the content of the nitride-based phosphor component 3 is 8 wt %, the content of the matrix component 4 is 90 wt %, and the content of the garnet-based phosphor component 2 is 2 wt %.

[0057] Point C indicates the point where the content of the nitride-based phosphor component 3 is 2 wt %, the content of the matrix component 4 is 90 wt %, and the content of the garnet-based phosphor component 2 is 8 wt %.

[0058] Point D indicates the point where the content of the nitride-based phosphor component 3 is 10 wt %, the content of the matrix component 4 is 31 wt %, and the content of the garnet-based phosphor component 2 is 59 wt %.

[0059] This makes it possible to provide a composite ceramic 1 for low color temperatures that has high fluorescent power relative to excitation light power, can withstand laser excitation, has high resistance to excitation light power, and is suitable for use with low color temperatures.

[0060] (Particle size of each component in composite ceramics 1) The particle sizes of the garnet-based phosphor component 2 and the nitride-based phosphor component 3 contained in the composite ceramic 1 may be appropriately set so as to obtain a desired emission spectrum depending on the types of the garnet-based phosphor component 2 and the nitride-based phosphor component 3. Therefore, the particle sizes of the garnet-based phosphor component 2 and the nitride-based phosphor component 3 are not particularly limited.

[0061] However, the raw material powder used as the raw material of the garnet-based phosphor component 2 (in other words, the garnet-based phosphor component before sintering) preferably has a number-average particle size in the range of 3 μm or more and 50 μm or less. If the number-average particle size of the raw material powder of the garnet-based phosphor component 2 is within the above range, it is difficult to react with the matrix component 4 and the nitride-based phosphor component 3.

[0062] Similarly, the raw material powder (i.e., the garnet-based phosphor component before sintering) used as the raw material of the nitride-based phosphor component 3 preferably has a number-average particle size in the range of 3 μm or more and 50 μm or less. When the number-average particle size of the raw material powder of the nitride-based phosphor component 3 is within the above range, it is difficult to react with the matrix component 4 and the garnet-based phosphor component 2.

[0063] The number average particle size of these raw material powders may be measured using a scanning electron microscope (SEM), or may be the specifications listed on the delivery note or catalog when commercially available raw material powders are used as they are.

[0064] Depending on the sintering method, these raw material powders may undergo grain growth during sintering. For this reason, the number-average particle size of the garnet-based phosphor component 2 contained per unit volume of the composite ceramic 1 is preferably, for example, in the range of 3 μm to 50 μm. Similarly, the number-average particle size of the nitride-based phosphor component 3 contained per unit volume of the composite ceramic 1 is preferably, for example, in the range of 3 μm to 50 μm. Note that while these phosphor particles ideally have the size of primary particles, they may also have the size of secondary particles formed by the adhesion of several primary particles.

[0065] As described above, the matrix component 4 is sintered while surrounding the garnet-based phosphor component 2 and the nitride-based phosphor component 3. For this reason, the number average particle size of the raw material powder used as the raw material for the matrix component 4 (in other words, the matrix component before sintering) is preferably smaller than the number average particle size of each raw material powder of the garnet-based phosphor component 2 and the nitride-based phosphor component 3. On the other hand, if the particle size of the raw material powder is too small, problems arise in terms of cost or hygroscopicity.

[0066] Therefore, from the viewpoint of reactivity, the raw material powder used as the raw material of the matrix component 4 is preferably raw material powder having a number average particle size in the range of 0.01 μm or more and 1 μm or less.

[0067] From the viewpoint of reactivity, it is preferable that the number average particle size of the matrix component 4 is smaller than the number average particle sizes of the garnet-based phosphor component 2 and the nitride-based phosphor component 3. As with the raw material powder of the garnet-based phosphor component 2 and the raw material powder of the nitride-based phosphor component 3, the raw material powder of the matrix component 4 may also undergo grain growth during sintering, depending on the sintering method.

[0068] Therefore, the number average particle size of the matrix component 4 contained per unit volume of the composite ceramic 1 is preferably within the range of 0.01 μm or more and 10 μm or less.

[0069] When the number average particle size of the matrix component 4 contained per unit volume of the composite ceramic 1 is within the above range, the sintering temperature can be further reduced, making it easier to produce composite ceramics containing red phosphors over a wide composition range.

[0070] Furthermore, by setting the number-average particle size of the matrix component 4 within the above range, the matrix component 4 penetrates into the gaps between the garnet-based phosphor component 2 and the nitride-based phosphor component 3. This makes it possible to obtain a sintered body with a dense structure. In this way, by setting the number-average particle size of the matrix component 4 within the above range, it is possible to obtain a composite ceramic 1 with a structure in which the matrix component 4 surrounds and sinters the garnet-based phosphor component 2 and the nitride-based phosphor component 3, and the adjacent phases are fixed together.

[0071] Furthermore, by setting the number average particle size of the garnet-based phosphor component 2, the number average particle size of the nitride-based phosphor component 3, and the number average particle size of the matrix component 4 within the above ranges, the phase structure of the composite ceramic 1 can be optimized.

[0072] The number average particle diameters of the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4 can be measured by SEM. The number average particle diameters of the other components described below can also be measured by SEM in the same way.

[0073] In this disclosure, "particle size" refers to the particle size when the component to be measured is a perfect sphere. From the perspective of easy control of luminescence characteristics, it is desirable that the garnet-based phosphor component 2, the nitride-based phosphor component 3, the matrix component 4, and their raw material powders are all spherical. However, these garnet-based phosphor component 2, the nitride-based phosphor component 3, the matrix component 4, and their raw material powders do not necessarily have a perfect spherical shape. If these raw material powders are spherical particles, the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4 contained in the composite ceramic 1 will also be roughly spherical. However, if these raw material powders are, for example, irregular, angular particles, the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4 contained in the composite ceramic 1 will also be irregular, angular particles. Furthermore, depending on the sintering method, the raw material powders may undergo grain growth and change shape during sintering. In this case, when the component to be measured is not a perfect sphere, the "particle size" means the particle size when converted into a perfect sphere of the same volume.

[0074] (sintering aid) The composite ceramic 1 may further contain a sintering aid. When the raw material powders (first raw material powders) including the raw material powders used as raw materials for the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4 contain a sintering aid, the composite ceramic 1 also contains a sintering aid.

[0075] The sintering aid used in the composite ceramic 1 may be at least one selected from the group consisting of Si3N4, SiO2, CaO, MgO, ZnO, Y2O3, LiF, and AlF3. However, when the matrix component 4 is MgO, MgO is excluded from the sintering aids. MgO can be used as a sintering aid when the matrix component is only Al2O3.

[0076] Therefore, when the matrix component 4 is Al2O3, at least one sintering aid selected from the group consisting of Si3N4, SiO2, CaO, MgO, ZnO, Y2O3, LiF, and AlF3 is used. On the other hand, when the matrix component 4 contains at least MgO among MgO and Al2O3, at least one sintering aid selected from the group consisting of Si3N4, SiO2, CaO, ZnO, Y2O3, LiF, and AlF3 is used.

[0077] When the first raw material powder contains a sintering aid, it becomes possible to further lower the sintering temperature, making it easier to produce the composite ceramic 1. This also makes it possible to further reduce the risk of deteriorating the performance of the phosphor.

[0078] The content of the sintering aid in the first raw material powder and the composite ceramic 1 made from the first raw material powder is preferably within a range of 0.05 wt % to 10 wt % inclusive, in order to prevent deterioration of the phosphor characteristics.

[0079] Furthermore, the number average particle size of the sintering aid contained per unit volume of the composite ceramic 1 is preferably in the range of 0.01 μm or more and 1 μm or less, in order to facilitate its effectiveness as a sintering aid. As such, the sintering aid is extremely fine and present in trace amounts compared to the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4, and therefore is not shown in the drawings.

[0080] [Thickness of composite ceramic 1] The thickness of the composite ceramic 1 is not particularly limited, but when used as a phosphor element in a laser illumination device, it is preferably within the range of, for example, 10 μm or more and 10 mm or less.

[0081] When the thickness of the composite ceramic 1 is 10 mm or less, the composite ceramic 1 is not too thick, has excellent heat dissipation properties, and can control the beam pattern by using a light-collecting member (described later) to prevent the beam output from the phosphor element from spreading too much. Also, when the thickness of the composite ceramic 1 is 10 μm or more, the composite ceramic 1 is not too thin, and can maintain the strength required for applying the composite ceramic 1 to a phosphor element.

[0082] Furthermore, by setting the thickness of the composite ceramic 1 within the above range, it is possible to transmit excitation light emitted from an excitation light source such as a laser light source.

[0083] [Light transmittance in composite ceramic 1] It is desirable that the composite ceramic 1 has a large light scattering property. If the fluorescent light or excitation light generated in the composite ceramic propagates laterally to the phosphor element, the beam emitted from the phosphor element will become blurred.

[0084] However, according to this embodiment, a composite ceramic 1 can be obtained in which the linear transmittance of light with a wavelength of 450 nm at a thickness of 100 μm is 0.01% or more and 20% or less. The linear transmittance of light can be measured using a spectrophotometer equipped with an integrating sphere or a light receiver having a laser light source and an aperture.

[0085] A phosphor element using a composite ceramic with such light transmittance reduces the amount of light propagating laterally across the main surface of the phosphor element inside the phosphor element, eliminating blurring of the beam diameter, making it advantageous as a phosphor element for laser illumination.

[0086] [Other properties of Composite Ceramics 1] The object color of Composite Ceramics 1 is L * a * b * It can be displayed in the above L color system. *is the brightness, and the above a * is the chromaticity between red and green, and the above b * is the chromaticity between yellow and blue. Also, the saturation is a * and b * The object color of Composite Ceramic 1 is expressed as the square root of the sum of the squares of L * a * b * It is preferable that the color is expressed within an appropriate range in the color system from the viewpoint of enhancing the fluorescent power of the composite ceramic.

[0087] L * a * b * The object color in the color system can be measured using a known colorimeter. * a * b * The object color in the color system can be adjusted by an annealing treatment, which will be described later.

[0088] The internal quantum efficiency of the composite ceramic 1 is preferably 70% or more and 95% or less.

[0089] [Method for manufacturing composite ceramic 1] Next, a method for producing the composite ceramic 1 will be described.

[0090] FIG. 2 is a flowchart showing an example of a method for manufacturing the composite ceramic 1 according to this embodiment.

[0091] The method for producing the composite ceramic 1 according to this embodiment includes at least the following steps S1 to S4.

[0092] As shown in FIG. 2, in the method for producing the composite ceramic 1, first, a first raw material powder containing a garnet-based phosphor component 2, a nitride-based phosphor component 3, and a matrix component 4 is mixed (step S1, mixing step).

[0093] Here, mixing the first raw material powder means mixing the components contained in the first raw material powder together. At this time, the first raw material powder may contain the sintering aid.

[0094] The first raw material powder is mixed by dry mixing, and any mixer may be used for the mixing as long as it is capable of powder mixing by a dry method.

[0095] Next, the first raw material powder mixed in the mixing step is placed in a molding die (step S2, first raw material powder placing step).

[0096] Next, the first raw material powder contained in the molding die is sintered (step S3, sintering step). At this time, the first raw material powder is sintered using SPS (spark plasma sintering) or hot pressing.

[0097] The SPS method and the hot pressing method are types of solid compression sintering methods, in which the first raw material powder placed in the molding die is press-molded while being heated.

[0098] In the SPS method, the compact is sintered by pulse current heating while being pressed using mechanical pressure. In addition to the thermal and mechanical energy used in regular sintering, the SPS method sinters the compact using a combination of sintering driving forces, including electromagnetic energy from pulse current, self-heating of the compact, and discharge plasma energy generated between each component.

[0099] As a result, the SPS method can sinter by raising the temperature to a high level in a short period of time while applying mechanical pressure, so even for the above-mentioned ternary, difficult-to-sinter green compacts, it is possible to sinter the green compact into a sintered compact in which each component contained in the green compact is bonded uniformly at a high density. Furthermore, the short sintering time of the SPS method makes it possible to suppress the grain growth of each component.

[0100] In the hot press method, sintering is carried out in a pressurized atmosphere, just like in the SPS method. When using the hot press method, the sintering time is longer than in the SPS method. However, the hot press method is excellent for mass production.

[0101] The first raw material powder may also be sintered by a high-speed sintering method.

[0102] The sintering temperature in the sintering step is preferably 1000° C. or higher and 2000° C. or lower. By setting the sintering temperature to 2000° C. or lower, the sintering temperature is not too high, and it is possible to prevent oxides from being generated or the components from dissolving into new compounds, thereby preventing the properties of the components from being lost.

[0103] Furthermore, by setting the sintering temperature to 1000°C or higher, the sintering temperature is not too low, and the primary particles of the above components are likely to be bonded together. As a result, the above components are likely to coexist without forming a solid solution, and adjacent phases are likely to be adhered to each other. This makes it easier to obtain a composite ceramic 1 that has sufficient processing strength as a bulk body and emits suitable warm white fluorescent light.

[0104] The sintering time in the sintering step is not particularly limited, and may be any time, for example, from 5 minutes to 20 hours.

[0105] Next, the sintered body obtained in the sintering step is removed from the molding die (step S4, demolding step), thereby obtaining the composite ceramic 1.

[0106] The method for producing the composite ceramic 1 may further include, after the demolding step, an annealing step (step S5) of annealing the sintered body obtained in the sintering step.

[0107] The annealing temperature is preferably, for example, 800° C. or higher and 1500° C. or lower. By annealing the sintered body at 800° C. or higher and 1500° C. or lower, it is possible to suitably prevent deformation of the composite ceramic 1 due to processing and to control defects in each phase.

[0108] The annealing time is not particularly limited and may be any time, for example, from 5 minutes to 20 hours.

[0109] The annealing is preferably carried out in a reducing atmosphere such as an N2 atmosphere or an H2 and N2 atmosphere (for example, an ammonia-containing gas).

[0110] A heat treatment step such as annealing may be performed in a reducing atmosphere or an inert gas atmosphere during the manufacturing process. This heat treatment step is effective in terms of developing a better object color of the composite ceramic 1, and may be performed at any time during the manufacturing process as long as such an effect can be obtained. This heat treatment step is preferably the annealing treatment described above, and the treatment temperature in the heat treatment step may be the same as the annealing temperature described above. Alternatively, this heat treatment step, unlike the annealing treatment, may be performed between any two of the above-mentioned steps.

[0111] The method for producing the composite ceramic 1 may further include a cutting / polishing step (step S6) of subjecting the sintered body to at least one of cutting and polishing.

[0112] The size of the composite ceramic 1 is not particularly limited, and the sintered body removed from the mold in the demolding step can be used as is as the composite ceramic 1. However, in order to make the composite ceramic 1 into a predetermined size, the obtained sintered body may be subjected to at least one of cutting and polishing as described above.

[0113] The method for cutting the sintered body is not particularly limited, and for example, the sintered body may be sliced ​​(cut) using a wire saw or the like. By cutting the sintered body, a thin composite ceramic 1 can be obtained. Of course, a thin composite ceramic 1 may also be produced without cutting by using a thin molding die or adjusting the amount of first raw material powder contained in the molding die.

[0114] The method for polishing the sintered body is not particularly limited. For example, the surface of the sintered body may be polished by rotating the polishing unit of a polishing device while discharging a polishing liquid from the discharge unit. This makes it possible to smooth the surface while reducing the thickness of the sintered body. Therefore, by polishing, a composite ceramic 1 that is thin and has a smooth surface can be obtained.

[0115] 2, both the annealing step and the cutting / polishing step are performed, but this embodiment is not limited to this. Only one of the annealing step and the cutting / polishing step may be performed. Furthermore, the annealing step may be performed after the cutting / polishing step.

[0116] [Embodiment 2] FIG. 3 is a cross-sectional view showing an example of the structure of the composite ceramic 11 according to this embodiment.

[0117] As shown in FIG. 3, composite ceramic 11 according to this embodiment has the same structure as composite ceramic 1 according to the first embodiment, except that composite ceramic 11 further contains light scattering components 12 .

[0118] The light scattering component 12 may be any light scattering material having a refractive index higher than that of the matrix component 4 by 0.21 or more.

[0119] In this way, when the composite ceramic further contains a light-scattering component 12 in addition to the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4, it is desirable that the total content of the matrix component 4 and the light-scattering component 12 be 31 wt% or more and 95 wt% or less of all components, from the viewpoint described below.

[0120] Conventionally known composite ceramics, when used in, for example, a phosphor element of a laser illumination device, have the problem that the fluorescence or excitation light generated in the composite ceramic propagates laterally through the phosphor element, causing the beam emitted from the phosphor element to become blurred.

[0121] However, according to this embodiment, in addition to the effects described in the first embodiment, it is possible to provide a composite ceramic 11 that has excellent light scattering properties and can efficiently extract the generated fluorescence and excitation light to the outside.

[0122] The light-scattering component 12 may be at least one selected from the group consisting of AlN, cBN, SiC, an AlN-SiC solid solution, and diamond. These light-scattering components have particularly excellent light-scattering properties and can be suitably used as the light-scattering component 12.

[0123] The upper limit of the refractive index difference between light-scattering component 12 used in this embodiment and matrix component 4 is not particularly limited. However, of MgO and Al2O3 used in matrix component 4, Al2O3 has a low refractive index, that is, 1.63, and when the above-exemplified light-scattering component is used as light-scattering component 12, SiC has the highest refractive index, that is, approximately 2.72. Therefore, when the above-exemplified light-scattering component is used as light-scattering component 12, the refractive index difference between light-scattering component 12 and matrix component 4 becomes a maximum of 1.1.

[0124] Furthermore, the number average particle size of the light-scattering component 12 contained per unit volume of the composite ceramic 1 is preferably 0.25 μm or more and 40 μm or less, and more preferably 0.5 μm or more and 20 μm or less. The number average particle size of the light-scattering component 12 may be measured by SEM or may be the specifications listed on the delivery note or catalog. When the number average particle size of the light-scattering component 12 is within the above range, light scattering is maximized due to Mie scattering.

[0125] When the number average particle size of the light-scattering component 12 is within the above range, the maximum light-scattering effect can be obtained.

[0126] Similar to the garnet-based phosphor component 2, the nitride-based phosphor component 3, and the matrix component 4, the first raw material powder contains raw material powder that serves as a raw material for light-scattering component 12, and thus composite ceramic 11 contains light-scattering component 12. Therefore, composite ceramic 11 can be produced by mixing a first raw material powder that further contains raw material powder that serves as a raw material for light-scattering component 12 in the mixing step (step S1).

[0127] Although not shown, it goes without saying that the composite ceramic 11 may also contain the sintering aid.

[0128] [Embodiment 3] FIG. 4 is a cross-sectional view showing an example of the structure of the composite ceramic 21 according to this embodiment.

[0129] 4, the composite ceramic 21 according to this embodiment has a layered structure including a first ceramic layer 22 and a second ceramic layer 23. The first ceramic layer 22 shown in FIG. 4 has the same configuration as the composite ceramic 1 according to the first embodiment.

[0130] The second ceramic layer 23 is made of at least one material selected from the group consisting of MgO and Al 2 O 3 , and is bonded to one main surface of the first ceramic layer 22 .

[0131] Conventionally, composite ceramics for high-power excitation that contain a red phosphor and can withstand laser excitation have not been realized. As described above, according to the first embodiment, it is possible to provide a composite ceramics for laser illumination 1 that contains a red phosphor and can be used for laser illumination using laser excitation. Therefore, the first ceramic layer 22 can be used by itself as a composite ceramics for laser illumination.

[0132] However, as described above, by bonding the second ceramic layer 23 having the above-described configuration onto the first ceramic layer 22, it is possible to suppress burning of the surface of the composite ceramic even when it is strongly excited by laser light. Therefore, according to this embodiment, it is possible to provide a composite ceramic 12 that can suppress surface deterioration due to such burning.

[0133] The thickness of the first ceramic layer 22 is not particularly limited, and can be set to the same thickness as that of the composite ceramic 1 according to the first embodiment, for example.

[0134] The thickness of the second ceramic layer 23 is not particularly limited, but it is desirable that the second ceramic layer 23 be formed thinner than the first ceramic layer 22, since the second ceramic layer 23 does not contain fluorescent components and does not contribute to fluorescent emission, and also from the standpoint of heat dissipation.

[0135] Therefore, it is desirable that the thickness of the second ceramic layer 23 be, for example, 30 μm or less. Also, in order to fully obtain the effect of suppressing burning of the surface of the composite ceramic, it is desirable that the thickness of the second ceramic layer 23 be, for example, 1 μm or more.

[0136] The method for producing the composite ceramic 21 is the same as the method for producing the composite ceramic 1 according to embodiment 1, except for the following points. The method for producing the composite ceramic 21 further includes a second raw material powder containing step of containing a second raw material powder, which is made of at least one material selected from the group consisting of MgO and Al2O3, in an amount smaller than the first raw material powder, in a molding die. Then, in the sintering step (step S3), the first raw material powder and the second raw material powder contained in the molding die are sintered. This forms a sintered body in which a sintered body of the first raw material powder and a sintered body of the second raw material powder, which is thinner than the first raw material powder, are bonded together. This allows the composite ceramic 21 to be produced.

[0137] The second raw material powder containing step may be performed after the first raw material powder containing step (step S2) (i.e., between step S2 and step S3), or may be performed before the first raw material powder containing step (step S2) (i.e., between step S1 and step S2).

[0138] However, considering the influence of stress or raw material shrinkage, it is desirable to perform the second raw material powder containing step twice, once before the first raw material powder containing step and once after the first raw material powder containing step. When the second raw material powder containing step is performed twice, once before and once after the first raw material powder containing step, a sintered body is obtained after the demolding step (step S4), in which the second ceramic layer 23 is formed with the first ceramic layer 22 sandwiched therebetween. That is, a sintered body having a three-layer structure is obtained, in which the second ceramic layer 23 is formed on both the front and back main surfaces of the first ceramic layer 22. In this case, after the demolding step, the second ceramic layer 23 on one main surface of the first ceramic layer 22 may be removed by grinding, polishing, or the like. The removal may be performed in the cutting / polishing step.

[0139] In addition, instead of removing the second ceramic layer 23 on one main surface of the first ceramic layer 22, the sintered body may be sliced ​​(cut) to produce multiple composite ceramics 21 in which the second ceramic layer 23 is formed on one main surface of the first ceramic layer 22.

[0140] Also in this embodiment, an annealing step (step S5) may be performed as necessary after the demolding step (step S4) or after the cutting / polishing step.

[0141] Although not shown, the composite ceramic 21 may also contain the sintering aid.

[0142] 4 illustrates an example in which the first ceramic layer 22 has the same configuration as the composite ceramic 1 according to the first embodiment, but the present embodiment is not limited to this. The first ceramic layer 22 may have the same configuration as the composite ceramic 11 according to the second embodiment.

[0143] [Embodiment 4] FIG. 5 is a cross-sectional view showing an example of the structure of the composite ceramic 31 according to this embodiment.

[0144] As shown in FIG. 5, the composite ceramic 31 according to this embodiment has the same configuration as, for example, the composite ceramic 1 according to the first embodiment, except that the composite ceramic 31 has irregularities 31a formed on one of its main surfaces.

[0145] Therefore, the method for producing the composite ceramic 21 is the same as the method for producing the composite ceramic 1 according to the first embodiment, except that it further includes a step of forming the irregularities 31a on one main surface of the sintered body.

[0146] 5 illustrates an example in which the irregularities 31a are dicer grooves. However, this embodiment is not limited to this. In the irregularity forming step, the irregularities 31a may be formed by, for example, a dicer or laser processing, or by roughening the main surface by polishing.

[0147] According to this embodiment, as described above, by forming the irregularities 31a on one of the main surfaces, it is possible to provide a composite ceramic 31 that can scatter the fluorescence or excitation light generated inside and extract it efficiently.

[0148] As described above, the height of the irregularities 31a on the surface is not particularly limited as long as it can scatter the fluorescent light or excitation light generated inside.

[0149] 5 illustrates an example in which the composite ceramic 31 has a configuration in which the asperities 31a are formed on one main surface of the composite ceramic 11. However, this embodiment is not limited to this. The composite ceramic 31 according to this embodiment may have a configuration in which the asperities 31a are formed on one main surface of the composite ceramic 11. Furthermore, the composite ceramic 31 according to this embodiment may have a configuration in which the asperities 31a are formed on the main surface of the second ceramic layer 23 of the composite ceramic 21 opposite to the first ceramic layer 22.

[0150] [Embodiment 5] FIG. 6 is a diagram showing a composite ceramic 1 according to this embodiment, in which an AR (anti-reflection) coating film 41 is provided on one of the main surfaces.

[0151] As shown in Fig. 6, the AR coating film 41 provided on the main surface of the composite ceramic 1 prevents the excitation light from being reflected from the irradiated surface when the composite ceramic 1 is used as a phosphor element for laser illumination. This reduces the loss of light when the excitation light is absorbed by the composite ceramic 1. Furthermore, the fluorescence or scattered light generated in the phosphor of the composite ceramic 1 can be effectively extracted.

[0152] The AR coating film 41 is made of a dielectric multilayer film of SiO2, TiO2, Si3N4, etc. These can be formed by a film forming method such as ion beam deposition or sputtering.

[0153] Hereinafter, the composite ceramic provided with the AR coating film 41 in this manner may be referred to as an AR-coated composite ceramic. The AR-coated composite ceramic to which the AR coating is applied is suitable for use in, for example, a phosphor element for laser illumination.

[0154] The excitation light power tolerance (element reliability) of the phosphor element is set at 0.5kW / cm from the viewpoint of laser lighting applications. 2 It is preferable that the voltage is 3kW / cm or more. 2 It is more preferable that the resistance to excitation light power of the phosphor element is higher, but an upper limit may be set from the viewpoint of obtaining sufficient effects in laser illumination applications. The element reliability of the phosphor element can be determined in the same way as that of the composite ceramics described above, and can also be adjusted in the same way.

[0155] FIG. 7 is a cross-sectional view showing an example of a phosphor element 50 according to this embodiment.

[0156] A phosphor element 50 shown in FIG. 7 includes the composite ceramic 1 provided with the AR coating film 41 shown in FIG.

[0157] The substrate 51 is a support member that supports the composite ceramic 1. The composite ceramic 1 is fixed on the substrate 51.

[0158] The substrate 51 is not particularly limited as long as it can fix the composite ceramic 1. As an example, the substrate 51 can be made of metal such as SUS, Al, Cu, Mo, Ag, or W. When the substrate 51 is made of these metals, it can suitably reflect excitation light irradiated from an excitation light source such as a laser light source.

[0159] Furthermore, since Al, Cu, Mo, Ag, W, etc. have excellent thermal conductivity, the phosphor element 50 can have excellent thermal conductivity.

[0160] However, the substrate 51 is not limited to such a non-transparent substrate, and may be a transparent substrate such as single crystal sapphire or polycrystalline alumina, for example, represented by Al2O3.

[0161] As shown in FIG. 7, the composite ceramic 1 is fixed to the substrate 51 so that the AR coating film 41 is positioned on the main surface opposite to the substrate 51.

[0162] The mirror 53 is a reflector (mirror body) that reflects light transmitted through the composite ceramic 1. The mirror 53 is provided on the main surface of the composite ceramic 1 that faces the substrate 51. Hereinafter, the main surface of the composite ceramic 1 that faces the substrate 51 may be referred to as the "rear main surface," and the main surface opposite the substrate 51 may be referred to as the "front main surface."

[0163] The mirror 53 is provided on the rear main surface of the composite ceramic 1, and the AR coating film 41 is provided on the front main surface of the composite ceramic.

[0164] By providing the mirror 53 on the back main surface side of the composite ceramic 1 in this manner, when excitation light is irradiated onto the front main surface side of the composite ceramic 1, the light that has passed through the composite ceramic 1 can be reflected by the mirror 53. This makes it possible to improve the light utilization efficiency.

[0165] The mirror 53 is not particularly limited as long as it can reflect light transmitted through the composite ceramic 1, but for example, a silver-based mirror containing silver or a silver alloy, which is a specular reflecting material, is preferably used.

[0166] The adhesive layer 52 is a layer that bonds the composite ceramic 1 on which the mirror 53 is provided and the substrate 51 together.

[0167] The adhesive material used for the adhesive layer 52 is not particularly limited as long as it can bond the composite ceramic 1 provided with the mirror 53 to the substrate 51. Examples of the adhesive material include a silver-based or silver alloy-based inorganic adhesive.

[0168] FIG. 8 is a flowchart showing an example of a method for manufacturing the phosphor element 50 shown in FIG.

[0169] 8, in the manufacturing method of the phosphor element 50, for example, the cutting / polishing step of step S6 includes a cutting step (step S11) of cutting the sintered body and a back main surface polishing step (step S12) of polishing the back main surface of the sintered body. However, as mentioned above, the cutting / polishing step is not essential.

[0170] Next, a mirror 53 is formed on the rear main surface of the sintered body (step S13, mirror forming step), thereby forming a mirror-attached composite ceramic in which the mirror 53 is bonded to one main surface of the composite ceramic 1.

[0171] On the other hand, a substrate 51 is prepared (step S21, substrate preparation step).

[0172] Next, the substrate 51 and the mirror-attached composite ceramic obtained in step S13 are bonded together with an adhesive material that forms the adhesive layer 52 (step S14, bonding step).

[0173] Next, the front main surface of the sintered body is polished (step S15, front main surface polishing step). After that, an AR coating film 41 is formed on the front main surface of the sintered body (step S16, AR coating film forming step). In this way, a phosphor element 50 can be manufactured as shown in FIG.

[0174] 8, the front surface polishing step is performed after the bonding step, but this embodiment is not limited to this. The front surface polishing step may be performed before the bonding step.

[0175] Furthermore, the phosphor element 50 according to this embodiment is not limited to the structure shown in Fig. 7. The phosphor element 50 may include, for example, a composite ceramic 1 and a base material 51 to which the composite ceramic 1 is fixed.

[0176] Moreover, instead of the composite ceramic 1, the composite ceramic 11, the composite ceramic 21, or the composite ceramic 31 may be provided. Also, a composite ceramic formed by combining these may be used.

[0177] [Embodiment 6] As described above, the composite ceramics can be suitably used in phosphor elements for laser illumination (in other words, phosphor elements for laser illumination devices).

[0178] The laser illuminator according to this embodiment includes a phosphor element, a laser light source that irradiates excitation light onto the composite ceramic in the phosphor element, and a focusing member (first focusing member) that focuses the light output from the composite ceramic in the phosphor element.

[0179] FIG. 9 is a cross-sectional view showing an example of a laser illuminator 60 according to this embodiment.

[0180] The laser illuminator 60 shown in Fig. 9 includes, as an example of the phosphor element, the phosphor element 50 shown in Fig. 8. The laser illuminator 60 shown in Fig. 9 also includes a laser light source 61 as the laser light source, and a lens 63 as the first focusing member. The laser illuminator 60 shown in Fig. 9 also includes a lens 62 as a second focusing member that focuses the excitation light output from the laser light source 61.

[0181] The laser light source 61 irradiates the composite ceramic 1 in the phosphor element 50 with excitation light L1 as a first light via a lens 62. Specifically, the excitation light L1 output from the laser light source 61 is condensed by the lens 62, and is irradiated from the lens 62 to the composite ceramic 1 in the phosphor element 50 as condensed excitation light L1 (hereinafter referred to as "excitation light L1'").

[0182] The composite ceramic 1 absorbs at least a portion of the excitation light L1′ and outputs second light including light with a different wavelength from the excitation light L1′ (i.e., light with a different wavelength from the excitation light L1). For example, the garnet-based phosphor component 2 emits, for example, yellowish fluorescence Y in response to the blue light that is the excitation light L1, and the nitride-based phosphor component 3 emits redish fluorescence R in response to the blue light that is the excitation light L1. These phosphors also scatter the blue light that is the excitation light L1 and does not contribute to excitation, transmitting it as blue scattered light B. As a result, when the composite ceramic 1 in the phosphor element 50 is irradiated with blue excitation light L1, the phosphor element 50 outputs blue scattered light B, yellowish fluorescence Y, and reddish fluorescence R, as shown in FIG. 9 . These lights (second lights) output from the phosphor element 50 (specifically, the composite ceramic 1 of the phosphor element 50) are condensed by the lens 63. Then, these lights (i.e., blue scattered light B, yellowish fluorescence Y, and reddish fluorescence R) output from the phosphor element 50 are mixed together, and reddish incandescent light is output as beam L2 through lens 63.

[0183] The phosphor element 50 may include the composite ceramic according to the present disclosure and a substrate 51, as described in the fifth embodiment. The composite ceramic may be any of the composite ceramics according to the first to fourth embodiments, or may be a composite ceramic formed by combining these.

[0184] The laser light source 61 is not particularly limited as long as it can emit the excitation light L1, but an example thereof is a blue semiconductor LD (LD: laser diode) that emits blue light as the excitation light L1 as described above.

[0185] When the phosphor element 50 is equipped with a mirror 53 as described above, or when the substrate 51 is a non-transparent substrate that does not transmit the excitation light L1, the phosphor element 50 is arranged so that the composite ceramic 1 is located on the light emission side of the laser light source 61.

[0186] On the other hand, when the substrate 51 is a transmissive substrate and does not have a reflector such as a mirror 53 on the rear main surface side of the composite ceramic 1, the excitation light L1 is irradiated from the surface of the substrate 51 opposite to the fixing surface of the composite ceramic 1. Note that, even in this case, the second light is output from the front main surface side of the composite ceramic 1.

[0187] 9 shows an example in which both the first and second light collecting members are lenses, but these light collecting members may also be lenses or mirrors.

[0188] [Embodiment 7: Other Forms of Composite Ceramics] The composite ceramic in the embodiment of the present invention may contain the above-mentioned La3Si6N instead of the garnet-based phosphor component within a range in which the effects of the present invention can be obtained. 11 In this case, the "nitride phosphor component" may be La3Si6N 11 The nitride-based phosphor component may be selected from nitride-based phosphor components other than the nitride-based phosphor component.

[0189] That is, the composite ceramic of the seventh embodiment is La3Si6N 11 system phosphor component and La3Si6N 11a composite ceramic comprising a sintered body containing a nitride-based phosphor component other than the La3Si6N-based phosphor component and a matrix component, wherein the matrix component is at least one selected from the group consisting of MgO and Al2O3, and the content of the matrix component is in the range of 31 wt% to 95 wt% of all components, and the matrix component is the La3Si6N-based phosphor component. 11 The nitride-based phosphor component and the nitride-based phosphor component may be surrounded and sintered.

[0190] The composite ceramic of the seventh embodiment uses the above-mentioned La3Si6N instead of the garnet-based phosphor component. 11 The composite ceramic can be constructed, manufactured, and used in the same manner as the composite ceramic of the previous embodiment, except that the garnet-based phosphor component is replaced with La3Si6N 11 The use of a phosphor component based on the lanthanum-based compound is advantageous in terms of easier production of composite ceramics.

[0191] [Embodiment 8: Other Forms of Composite Ceramics] The composite ceramic in the embodiment of the present invention contains substantially La3Si6N as a phosphor component within a range in which the effects of the present invention can be obtained. 11 The composite ceramic of the eighth embodiment may contain only the La3Si6N-based phosphor component (nitride phosphor (C)). 11 a composite ceramic comprising a sintered body substantially containing only a La3Si6N based phosphor component and a matrix component, wherein the matrix component is at least one component selected from the group consisting of Al2O3, a mixture of Al2O3 and MgO, and MgAlO2, and the content of the matrix component is within a range of 31 wt% to 95 wt% of all components, and the matrix component is the La3Si6N 11 The phosphor component may be sintered around the phosphor.

[0192] In this embodiment, the content of the matrix component and the content of the nitride phosphor (C) can be appropriately set from the viewpoint of providing a composite ceramic for low color temperature use that has high fluorescent power and high resistance to excitation light power.

[0193] The composite ceramic of the eighth embodiment is made of La3Si6N instead of the garnet-based phosphor component and the nitride-based phosphor component. 11 The composite ceramic can be constructed, manufactured, and used in the same manner as the composite ceramic of the previous embodiment, except that the phosphor component is substantially La3Si6N. 11 Since the composite ceramics are made of only the phosphor component, it is advantageous from the viewpoint of easier production of the composite ceramics.

[0194] 〔summary〕 A first aspect of the present invention is a composite ceramic comprising a sintered body containing a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component, wherein the matrix component is at least one selected from the group consisting of MgO and Al2O3, the content of the matrix component is in the range of 31 wt% to 95 wt% of all components, and the matrix component is sintered while surrounding the garnet-based phosphor component and the nitride-based phosphor component.

[0195] A second aspect of the present invention is characterized in that, in the first aspect, the number average particle size of the matrix component contained per unit volume of the composite ceramic is in the range of 0.01 μm or more and 10 μm or less.

[0196] A third aspect of the present invention is the second aspect, wherein the garnet-based phosphor component is (Ce,Y)3Al5O 12 , (Ce,Lu)3Al5O 12 , (Ce,Lu,Y)3Al5O 12 , (Ce,Lu,Y)3(Al,Ga)5O 12 The present invention is characterized in that it contains at least one selected from the group consisting of:

[0197] A fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, the nitride-based phosphor component contains at least one selected from the group consisting of Sr2Si5N8, (Sr,Ba)2Si5N8, and (Ca,Sr,Ba)2Si5N8, each activated with at least one element of Eu and Ce.

[0198] A fifth aspect of the present invention is characterized in that in the fourth aspect, at least one of a portion of the Si and a portion of the N is substituted, and when a portion of the Si is substituted, the Si is substituted with Al, and when a portion of the N is substituted, the N is substituted with O.

[0199] A sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the nitride-based phosphor component contains at least one selected from the group consisting of CaAlSiN3 and (Ca,Sr)AlSiN3, each activated with at least one element of Eu and Ce.

[0200] A seventh aspect of the present invention is, in any one of the first to sixth aspects, characterized in that in a ternary diagram in which the total content of the nitride-based phosphor component, the matrix component, and the garnet-based phosphor component is 100 wt%, the respective contents of the nitride-based phosphor component, the matrix component, and the garnet-based phosphor component are as follows: Point A where the content of the nitride-based phosphor component is 59 wt %, the content of the matrix component is 31 wt %, and the content of the garnet-based phosphor component is 10 wt %; Point B, where the content of the nitride-based phosphor component is 8 wt%, the content of the matrix component is 90 wt%, and the content of the garnet-based phosphor component is 2 wt%; Point C, where the content of the nitride-based phosphor component is 2 wt%, the content of the matrix component is 90 wt%, and the content of the garnet-based phosphor component is 8 wt%; The content of the nitride-based phosphor component is 10 wt%, the content of the matrix component is 31 wt%, and the content of the garnet-based phosphor component is 59 wt%. The content is within the range surrounded by a straight line connecting point D, where point D is the content of the nitride-based phosphor component, 10 wt%, the content of the matrix component is 31 wt%, and the content of the garnet-based phosphor component is 59 wt%.

[0201] An eighth aspect of the present invention is characterized in that, in any of the first to seventh aspects, the composition further contains a light-scattering component having a refractive index higher than that of the matrix component by 0.21 or more, and the total content of the matrix component and the light-scattering component is 31 wt% or more and 95 wt% or less of all components.

[0202] A ninth aspect of the present invention is the eighth aspect, characterized in that the light scattering component is at least one selected from the group consisting of AlN, cBN, SiC, an AlN-SiC solid solution, and diamond.

[0203] A tenth aspect of the present invention is characterized in that, in the eighth or ninth aspect, the number average particle size of the light scattering component contained per unit volume of the composite ceramic is 0.25 μm or more and 40 μm or less.

[0204] An eleventh aspect of the present invention is characterized in that, in any one of the first to tenth aspects, the linear transmittance of light with a wavelength of 450 nm at a thickness of 100 μm is 0.01% or more and 20% or less.

[0205] A twelfth aspect of the present invention is the method according to any one of the first to eleventh aspects, further comprising a sintering aid, wherein the sintering aid is When the matrix component is Al2O3, it is at least one selected from the group consisting of Si3N4, SiO2, CaO, MgO, ZnO, and Y2O3, When the matrix component contains at least MgO out of MgO and Al2O3, it is characterized in that it is at least one selected from the group consisting of Si3N4, SiO2, CaO, ZnO and Y2O3.

[0206] A thirteenth aspect of the present invention is characterized in that, in any one of the first to twelfth aspects, it has a laminated structure in which a layer made of at least one selected from the group consisting of MgO and Al2O3 is bonded to one main surface.

[0207] A fourteenth aspect of the present invention is a laser diode according to any one of the first to thirteenth aspects, wherein the pumping light power tolerance is 0.5 kW / cm 2 The present invention is characterized in that:

[0208] A fifteenth aspect of the present invention is characterized in that in any one of the first to fourteenth aspects, one of the main surfaces has projections and recesses formed thereon.

[0209] A sixteenth aspect of the present invention is a phosphor element comprising the composite ceramic of any one of the first to fifteenth aspects and a substrate for fixing the composite ceramic.

[0210] A seventeenth aspect of the present invention is a laser illumination device comprising: the phosphor element of the sixteenth aspect; a laser light source that irradiates excitation light onto the composite ceramic in the phosphor element; and a focusing member that focuses light output from the composite ceramic in the phosphor element.

[0211] An eighteenth aspect of the present invention is a method for producing a composite ceramic, comprising: a mixing step of mixing a first raw material powder including a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component; a first raw material powder containing step of containing the mixed first raw material powder in a molding die; a sintering step of sintering the first raw material powder contained in the molding die by spark plasma sintering or hot pressing; and a demolding step of removing the sintered body obtained in the sintering step from the molding die.

[0212] A nineteenth aspect of the present invention is characterized in that, in the eighteenth aspect, it further includes a second raw material powder containing step of containing, into the molding die, a second raw material powder consisting of at least one kind selected from the group consisting of MgO and Al2O3, in an amount smaller than the first raw material powder, and in the sintering step, the first raw material powder and the second raw material powder contained in the molding die are sintered to form a sintered body in which a sintered body of the first raw material powder and a sintered body of the second raw material powder, which is thinner than the first raw material powder, are joined together.

[0213] A twentieth aspect of the present invention is characterized in that, in the eighteenth or nineteenth aspect, the method further comprises a cutting / polishing step of subjecting the sintered body to at least one of cutting and polishing.

[0214] A twenty-first aspect of the present invention is characterized in that, in any one of the eighteenth to twentieth aspects, the method further comprises a step of forming irregularities on one main surface of the sintered body.

[0215] A twenty-second aspect of the present invention is the twenty-first aspect, characterized in that in the unevenness forming step, the unevenness is formed by a dicer, laser processing, or polishing.

[0216] A twenty-third aspect of the present invention is a (La)3Si6N nitride phosphor according to the first aspect, wherein the nitride phosphor component is activated with at least one element of Eu and Ce. 11、 (La,Y)3Si6N 11、 (La, Y, Lu)3Si6N 11 The present invention is characterized in that it contains at least one selected from the group consisting of:

[0217] A twenty-fourth aspect of the present invention is the fourteenth aspect, wherein the pumping light power tolerance is 1 kW / cm 2 The present invention is characterized in that:

[0218] The twenty-sixth aspect of the present invention is characterized in that, in any of the first to fifteenth aspects and the twenty-third to twenty-fifth aspects, the internal quantum efficiency is 70% or more and 95% or less.

[0219] A thirty-first aspect of the present invention is the sixteenth aspect, wherein the pumping light power tolerance is 0.5 kW / cm 2 The present invention is characterized in that:

[0220] A thirty-first aspect of the present invention is the sixteenth aspect, wherein the pumping light power tolerance is 3 kW / cm 2 17. The phosphor element according to claim 16, wherein the phosphor element is one of the above.

[0221] A thirty-second aspect of the present invention is characterized in that, in any of the eighteenth to twenty-second aspects, the method further comprises a step of heat-treating the sintered body in a reducing atmosphere or an inert gas atmosphere during the manufacturing process.

[0222] A thirty-third aspect of the present invention is the thirty-second aspect, characterized in that the heat treatment step is a step of heat treating the sintered body in an ammonia-containing gas.

[0223] A thirty-fourth aspect of the present invention is La3Si6N 11 system phosphor component and La3Si6N 11 a composite ceramic comprising a sintered body containing a nitride-based phosphor component other than the La3Si6N-based phosphor component and a matrix component, wherein the matrix component is at least one selected from the group consisting of MgO and Al2O3, and the content of the matrix component is in the range of 31 wt% to 95 wt% of all components, and the matrix component is the La3Si6N-based phosphor component. 11 The thirty-fourth aspect may further include any of the features of the second to fifteenth aspects and the twenty-third to twenty-ninth aspects, within the scope of obtaining the effects of the aspect.

[0224] A thirty-fifth aspect of the present invention is La3Si6N 11a composite ceramic comprising a sintered body substantially containing only a La3Si6N based phosphor component and a matrix component, wherein the matrix component is at least one component selected from the group consisting of Al2O3, a mixture of Al2O3 and MgO, and MgAlO2, and the content of the matrix component is within a range of 31 wt% to 95 wt% of all components, and the matrix component is the La3Si6N 11 The thirty-fifth aspect may further include any of the features of the second to fifteenth aspects and the twenty-third to twenty-ninth aspects, to the extent that the effects of the aspect can be obtained.

[0225] [Example] The composite ceramic according to the present disclosure will be specifically described below using examples and comparative examples. However, the composite ceramic according to the present disclosure is not limited to these examples. In the following examples and comparative examples, the raw material powder used was YAG activated with 2 mol% Ce and having a number average particle size of 15 μm. The raw material powder used was Sr2Si5N8 activated with 2 mol% Eu and having a number average particle size of 13 μm (including some aggregated powder). The raw material powder used was Al2O3 with a number average particle size of 0.1 μm. The raw material powder used was MgO with a number average particle size of 0.05 μm. The raw material powder used was AlN with a number average particle size of 1 μm.

[0226] Example 1 As shown in FIG. 10, in Example 1, the raw material powders were mixed so that the contents of the garnet-based phosphor component YAG, the nitride-based phosphor component Sr2Si5N8, and the matrix component Al2O3 were 25 wt%, 25 wt%, and 50 wt%, respectively.

[0227] Next, this raw material powder was filled into a mold and sintered at 1350°C for 3 minutes in a nitrogen atmosphere using the SPS method to produce composite ceramics.

[0228] The composite ceramics thus obtained were subjected to XRD (X-ray diffraction) measurement using a powder X-ray diffractometer manufactured by Rigaku Corp. The results are shown in FIG.

[0229] The laser power dependence of the fluorescence power of the resulting composite ceramics was measured using a phosphor evaluation device equipped with a laser light source, an integrating sphere, and a spectrometer. The excitation laser beam of the laser light source had a diameter of 1 mm, a wavelength of 450 nm, and was continuous light. The results are shown in Figure 12. The arrow in Figure 12 indicates the fluorescence saturation point.

[0230] The composite ceramic was irradiated with excitation light from a laser light source, and the fluorescence spectrum of the beam emitted from the composite ceramic through a lens was measured using a fluorescence spectrometer. More specifically, the emission spectrum was measured at room temperature with the excitation wavelength fixed at 441 nm using a spectrometer manufactured by Ocean Photonics, Inc. The results are shown in Figure 13.

[0231] Example 2 10, in Example 2, the raw material powders were mixed so that the contents of YAG, Sr2Si5N8, and Al2O3 were 15 wt%, 15 wt%, and 70 wt%, respectively. Except for this, in Example 2, a composite ceramic was produced by the same procedure as in Example 1.

[0232] The surface of the composite ceramic was observed at an acceleration voltage of 20 kV using a scanning electron microscope (SEM) manufactured by JEOL Ltd., and an SEM image was obtained. This SEM image is shown in FIG.

[0233] The composite ceramic thus obtained was subjected to XRD measurement using the same X-ray diffractometer as in Example 1. The results are shown in FIG.

[0234] The laser power dependency of the fluorescent power of the resulting composite ceramic was measured using the same phosphor evaluation device as in Example 1. The results are shown in FIG.

[0235] Furthermore, using the same apparatus as in Example 1, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured using the same fluorescence spectrometer as in Example 1. The results are shown in FIG.

[0236] Example 3 10, in Example 3, the raw material powders were mixed so that the contents of YAG, Sr2Si5N8, and Al2O3 were 5 wt%, 5 wt%, and 90 wt%, respectively, and sintered at 1300° C. Except for this, in Example 3, the composite ceramics were produced by the same procedure as in Example 1.

[0237] The laser power dependency of the fluorescent power of the resulting composite ceramic was measured using the same phosphor evaluation device as in Example 1. The results are shown in FIG.

[0238] Then, using the same device as in Example 1, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured using the same fluorescence spectrometer as in Example 1. The results are shown in FIG.

[0239] Example 4 As shown in Figure 10, composite ceramics were manufactured in the same manner as in Example 1, except that the contents of YAG, Sr2Si5N8, and Al2O3 were 34.5 wt%, 34.5 wt%, and 31 wt%, respectively. Furthermore, the laser power dependence of the fluorescence power of the obtained composite ceramics was measured in the same manner as in Example 1. The excitation light power at the fluorescence saturation point was 3 W, and the excitation light power tolerance was / (3.1415 × 0.05 × 0.05) = 0.38 kW / cm 2 Furthermore, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured in the same manner as in Example 1. The peak wavelength was 600 nm.

[0240] Example 5 As shown in Figure 10, composite ceramics were produced in the same manner as in Example 1, except that the contents of YAG, Sr2Si5N8, and Al2O3 were 20 wt%, 10 wt%, and 70 wt%, respectively. Furthermore, the laser power dependence of the fluorescence power of the obtained composite ceramics was measured in the same manner as in Example 1. The excitation light power at the fluorescence saturation point was 10 W, and the excitation light power tolerance was 10 / (3.1415 × 0.05 × 0.05) = 1.3 kW / cm. 2 Furthermore, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured in the same manner as in Example 1. The peak wavelength was 590 nm.

[0241] Comparative Example 1 As shown in Figure 10, in Comparative Example 1, only Sr2Si5N8 was filled into a mold and sintered at 1800°C. Except for this, in Comparative Example 1, the same operations as in Example 1 were carried out to produce a comparative composite ceramic.

[0242] Then, the laser power dependency of the fluorescent power of the obtained composite ceramic was measured using the same phosphor evaluation device as in Example 1. The results are shown in FIG.

[0243] Furthermore, using the same device as in Example 1, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured using the same fluorescence spectrometer as in Example 1. The results are shown in FIG.

[0244] Comparative Example 2 As shown in Figure 10, it is a binary composite ceramic of Sr2Si5N8 red phosphor and Al2O3.

[0245] Comparative Example 3 As shown in Figure 10, it is a binary composite ceramic of YAG and Al2O3.

[0246] Comparative Example 4 As shown in Figure 10, we attempted to manufacture composite ceramics in the same manner as in Example 1, except that the contents of YAG, Sr2Si5N8, and Al2O3 were 15 wt%, 65 wt%, and 20 wt%, respectively, but the sintered body cracked or broke, making it impossible to obtain a composite and to evaluate its characteristics. This is thought to be due to the large content of YAG phosphor particles and Sr2Si5N8 phosphor particles, which are large in size, preventing successful sintering.

[0247] Comparative Example 5 The same investigation was carried out as in Example 5 except for the contents of YAG, Sr2Si5N8 and Al2O3. The state of cracking and breakage was the same as in Comparative Example 4.

[0248] Table 1 shows the laser power dependence and peak wavelength of the output beam for the composite ceramics of Examples 4 and 5.

[0249] [Table 1]

[0250] Example 6 22, in Example 6, MgO was used instead of Al2O3, and the raw material powders were mixed so that the contents of YAG, Sr2Si5N8, and MgO were 15 wt%, 15 wt%, and 70 wt%, respectively, and sintered at 1300° C. Except for this, in Example 6, a composite ceramic was produced using the same procedure as in Example 1.

[0251] The laser power dependency of the fluorescent power of the resulting composite ceramic was measured using the same phosphor evaluation device as in Example 1. The results are shown in FIG.

[0252] Furthermore, using the same apparatus as in Example 1, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured using the same fluorescence spectrometer as in Example 1. The results are shown in FIG.

[0253] Example 7 22, in Example 7, approximately 10% of MgO was replaced with AlN as a light scattering component, and the raw material powders were mixed so that the contents of YAG, Sr2Si5N8, MgO, and AlN were 15 wt%, 15 wt%, 63 wt%, and 7 wt%, respectively. Except for this, in Example 7, a composite ceramic was produced using the same procedure as in Example 1.

[0254] The laser power dependence of the fluorescent power of the obtained composite ceramic was measured using the same phosphor evaluation device as in Example 1. The results are shown in FIG. 25 together with the laser power dependence of the fluorescent power of the composite ceramic obtained in Example 6.

[0255] Comparative Example 6 As shown in FIG. 22, Comparative Example 6 is a composite ceramic made of a binary system of Sr2Si5N8 and MgO.

[0256] Comparative Example 7 As shown in Figure 22, it is a binary composite ceramic made of YAG and MgO.

[0257] Comparative Example 8 As shown in Figure 22, an attempt was made to produce composite ceramics in the same manner as in Example 6, except that the contents of YAG, Sr2Si5N8, and MgO were 65 wt%, 15 wt%, and 20 wt%, respectively. However, the sintered body crumbled or cracked, and no composite ceramics were obtained.

[0258] Comparative Example 9 As shown in Figure 22, an attempt was made to produce composite ceramics in the same manner as in Example 6, except that the contents of YAG, Sr2Si5N8, and MgO were 15 wt%, 65 wt%, and 20 wt%, respectively. However, the sintered body crumbled or cracked, and no composite ceramics were obtained.

[0259] The SEM image shown in Figure 14 is a backscattered electron image of the composite ceramic shown in Example 1. The parts composed of heavy elements appear white, and the parts composed of light elements appear dark. The shape of each component corresponds to the shape of the raw material particles. From the results shown in Figure 14, it was confirmed that the composite ceramic obtained contained YAG, Sr2Si5N8, and Al2O3, and that Al2O3 was sintered surrounding the YAG and Sr2Si5N8.

[0260] 11 and 15, the XRD measurement confirmed the peaks of YAG, Sr2Si5N8, and Al2O3. The XRD measurement results and the diffraction intensities from the database were in good agreement, and no peaks other than those of YAG, Sr2Si5N8, and Al2O3 were observed.

[0261] Furthermore, it has been known that nitrides and oxides are incompatible with each other, as can be seen from the comparative examples in Patent Document 2. However, as shown in Figures 11 and 15, it was confirmed that in the composite ceramic according to the present disclosure, the nitride phosphor component Sr2Si5N8 remains even in the matrix component made of an oxide such as Al2O3.

[0262] Furthermore, from the fluorescence spectra shown in FIGS. 13, 17, 19, and 24, in Examples 1 to 4, the peaks of the fluorescence emitted from YAG and Sr2Si5N8 were observed, respectively.

[0263] Furthermore, from the fluorescence spectrum shown in FIG. 21, in Comparative Example 1, a fluorescence peak was observed only for Sr2Si5N8.

[0264] 12, in Example 1, the fluorescence is saturated when the pumping light power is 5 W, and the saturation point of the fluorescence is 5 W. Therefore, the pumping light power tolerance of Example 1 is 5 / (3.1415×0.05×0.05)=0.64 kW / cm 2 This becomes:

[0265] 16, in Example 2, only pumping light powers up to 7 W were measured, but from Fig. 16, it is estimated that the saturation point of the fluorescence is about 8 W or more. Therefore, if the saturation point of the fluorescence is 8 W, the pumping light power tolerance of Example 2 is 8 / (3.1415 × 0.05 × 0.05) = 1.0 kW / cm 2 This becomes:

[0266] 18, in Example 3, the saturation point of the fluorescence is 10 W. Therefore, the pumping light power tolerance of Example 3 is 10 / (3.1415×0.05×0.05)=1.3 kW / cm 2 This becomes:

[0267] 20, in Comparative Example 1, the saturation point of the fluorescence is 2 W. Therefore, the pumping light power tolerance of Comparative Example 1 is 2 / (3.1415×0.05×0.05)=0.25 kW / cm 2 This becomes:

[0268] 23, in Example 4, only pumping light powers up to 7 W were measured, but from Fig. 23, it is estimated that the saturation point of fluorescence is about 9 W or more. Therefore, if the saturation point of fluorescence is assumed to be 9 W, the pumping light power tolerance of Example 4 is 9 / (3.1415 × 0.05 × 0.05) = 1.1 kW / cm 2 This becomes:

[0269] Therefore, from the results shown in Figures 12, 16, 18, 20, and 23, it can be seen that nitride-based phosphors have low excitation light power resistance (laser power resistance), and that the addition of garnet-based phosphor components and matrix components significantly improves excitation light power resistance.

[0270] Furthermore, from the results shown in FIG. 25, it was confirmed that the fluorescent power can be improved by approximately 10% or more by including, as a light scattering component, for example, AlN with a high refractive index in part of the matrix component.

[0271] Example 8 As shown in Figure 26, composite ceramics were manufactured in the same manner as in Example 1, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 15 wt%, 15 wt%, and 70 wt%, respectively. Furthermore, the laser power dependence of the fluorescence power of the obtained composite ceramics was measured in the same manner as in Example 1. The excitation light power at the fluorescence saturation point was 6 W, and the excitation light power tolerance was 6 / (3.1415 × 0.05 × 0.05) = 0.76 kW / cm. 2 Furthermore, the fluorescence spectrum of the beam output from the composite ceramic after passing through a lens was measured in the same manner as in Example 1. The peak wavelength was 605 nm.

[0272] Example 9 26, composite ceramics were produced in the same manner as in Example 1, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 20 wt%, 10 wt%, and 70 wt%, respectively. In addition, the laser power dependence of the fluorescence power of the obtained composite ceramics was measured in the same manner as in Example 1.

[0273] Example 10 26, composite ceramics were produced in the same manner as in Example 1, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 25 wt%, 5 wt%, and 70 wt%, respectively. In addition, the laser power dependence of the fluorescence power of the obtained composite ceramics was measured in the same manner as in Example 1.

[0274] Example 11 26, composite ceramics were produced in the same manner as in Example 1, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 8 wt%, 2 wt%, and 90 wt%, respectively. In addition, the laser power dependence of the fluorescence power of the obtained composite ceramics was measured in the same manner as in Example 1.

[0275] Example 12 As shown in FIG. 26, composite ceramics were produced in the same manner as in Example 1, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 35 wt%, 33 wt%, and 32 wt%, respectively.

[0276] Comparative Example 10 As shown in Figure 26, an attempt was made to produce composite ceramics in the same manner as in Example 8, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 85 wt%, 15 wt%, and 0 wt%, respectively. However, the sintered body crumbled or cracked, and no composite ceramics were obtained.

[0277] Comparative Example 11 As shown in Figure 26, an attempt was made to produce a composite ceramic in the same manner as in Example 8, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 40 wt%, 40 wt%, and 20 wt%, respectively. However, the sintered body crumbled or cracked, and no composite ceramic was obtained.

[0278] Comparative Example 12 As shown in FIG. 26, composite ceramics were produced in the same manner as in Example 8, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were set to 0 wt%, 30 wt%, and 70 wt%, respectively.

[0279] Comparative Example 13 As shown in FIG. 26, composite ceramics were produced in the same manner as in Example 8, except that the contents of YAG, (BaSr)2Si5N8, and Al2O3 were 30 wt%, 0 wt%, and 70 wt%, respectively.

[0280] Table 2 shows the laser power dependence and peak wavelength of the output beam for the composite ceramics of Examples 8 to 12 and Comparative Examples 10 to 13.

[0281] [Table 2]

[0282] Example 13 As shown in Figure 27, YAG 、C aA lS A composite ceramic was produced in the same manner as in Example 1, except that the contents of iN3 ​​and Al2O3 were 15 wt%, 15 wt%, and 70 wt%, respectively.

[0283] Example 14 As shown in Figure 27, YAG 、C aA lS A composite ceramic was produced in the same manner as in Example 1, except that the contents of iN3 ​​and Al2O3 were 20 wt%, 10 wt%, and 70 wt%, respectively.

[0284] Example 15 As shown in Figure 27, YAG 、C aA lS A composite ceramic was produced in the same manner as in Example 1, except that the contents of iN3 ​​and Al2O3 were 25 wt%, 5 wt%, and 70 wt%, respectively.

[0285] Example 16 As shown in Figure 27, YAG 、C aA lS A composite ceramic was produced in the same manner as in Example 1, except that the contents of iN3 ​​and Al2O3 were 25 wt%, 25 wt%, and 50 wt%, respectively.

[0286] Example 17 As shown in Figure 27, YAG 、C aA lS A composite ceramic was produced in the same manner as in Example 1, except that the contents of iN3 ​​and Al2O3 were 35 wt%, 33 wt%, and 32 wt%, respectively.

[0287] Example 18 As shown in Figure 27, YAG 、C aA lSA composite ceramic was produced in the same manner as in Example 1, except that the contents of iN3 ​​and Al2O3 were 10 wt%, 5 wt%, and 85 wt%, respectively.

[0288] Comparative Example 14 As shown in Figure 27, YAG 、C aA lS Composite ceramics were produced in the same manner as in Example 13, except that the contents of iN3 ​​and Al2O3 were 30 wt%, 0 wt%, and 70 wt%, respectively.

[0289] Comparative Example 15 As shown in Figure 27, YAG 、C aA lS An attempt was made to produce composite ceramics in the same manner as in Example 13, except that the contents of iN3 ​​and Al2O3 were 85 wt%, 15 wt%, and 0 wt%, respectively. However, the sintered body crumbled and no green body could be obtained, and no composite ceramics were obtained.

[0290] Comparative Example 16 As shown in Figure 27, YAG 、C aA lS An attempt was made to produce composite ceramics in the same manner as in Example 13, except that the contents of iN3 ​​and Al2O3 were 40 wt%, 40 wt%, and 20 wt%, respectively. However, the sintered body crumbled and no green body could be obtained, and no composite ceramics were obtained.

[0291] Comparative Example 17 As shown in Figure 27, YAG 、C aA lS Composite ceramics were produced in the same manner as in Example 13, except that the contents of iN3 ​​and Al2O3 were 0 wt%, 30 wt%, and 70 wt%, respectively.

[0292] [Reference example 1] YAG 、C aA lS iN3 and (LaY)3Si6N 11A composite ceramic was produced in the same manner as in Example 11, except that the contents of Al2O3 and Al2O3 were 20 wt%, respectively, and 10 wt% and 70 wt% in total.

[0293] [Reference example 2] YAG 、C aA lS iN3 and (LaY)3Si6N 11 A composite ceramic was produced in the same manner as in Example 11, except that the contents of Al2O3 and Al2O3 were 25 wt%, respectively, and 5 wt% and 70 wt% in total.

[0294] [Reference example 3] YAG 、C aA lS iN3 and (LaY)3Si6N 11 Composite ceramics were produced in the same manner as in Example 11, except that the contents of Al2O3 and Al2O3 were 30 wt%, respectively, and 0 wt% and 70 wt% overall.

[0295] [Reference example 4] (LaY)3Si6N 11 、C aA lS Composite ceramics were produced in the same manner as in Example 11, except that the contents of iN3 ​​and Al2O3 were 20 wt%, 10 wt%, and 70 wt%, respectively.

[0296] [Reference example 5] (LaY)3Si6N 11 、C aA lS A composite ceramic was produced in the same manner as in Example 11, except that the contents of iN3 ​​and Al2O3 were 25 wt%, 5 wt%, and 70 wt%, respectively.

[0297] [Reference example 6] (LaY)3Si6N 11 、C aA lSComposite ceramics were produced in the same manner as in Example 11, except that the contents of iN3 ​​and Al2O3 were 30 wt%, 0 wt%, and 70 wt%, respectively.

[0298] [Reference example 7] (LaY)3Si6N 11 Composite ceramics were produced in the same manner as in Example 1, except that the contents of MgO and Al2O3 were 30 wt%, 0 wt%, and 70 wt%, respectively.

[0299] [Reference example 8] (LaY)3Si6N 11 A composite ceramic was produced in the same manner as in Example 1, except that the contents of MgO and Al2O3 were 30 wt%, 35 wt%, and 35 wt%, respectively.

[0300] [Reference example 9] (LaY)3Si6N 11 Composite ceramics were produced in the same manner as in Example 1, except that the contents of MgO and Al2O3 were 30 wt%, 70 wt%, and 0 wt%, respectively.

[0301] [Reference example 10] (LaY)3Si6N 11 A composite ceramic was produced in the same manner as in Example 1, except that the contents of MgO and Al2O3 were 30 wt%, 60 wt%, and 10 wt%, respectively.

[0302] [Reference example 11] (LaY)3Si6N 11 A composite ceramic was produced in the same manner as in Example 1, except that the contents of MgO and Al2O3 were 10 wt%, 50 wt%, and 40 wt%, respectively.

[0303] [Reference examples 12-16] The composite ceramic of Example 11 was annealed at 1000°C for 3 hours in an ammonia atmosphere to obtain a composite ceramic of Reference Example 12. The composite ceramic of Example 18 was annealed at 1250°C for 2 hours in an ammonia atmosphere to obtain a composite ceramic of Reference Example 13. The composite ceramic of Reference Example 4 was annealed at 1000°C for 3 hours in an ammonia atmosphere to obtain a composite ceramic of Reference Example 14. The composite ceramic of Reference Example 9 was annealed at 1250°C for 2 hours in an ammonia atmosphere to obtain a composite ceramic of Reference Example 15. The composite ceramic of Reference Example 8 was annealed at 1000°C for 3 hours in an ammonia atmosphere to obtain a composite ceramic of Reference Example 16.

[0304] For each of the composite ceramics of Reference Examples 12 to 16, L * a * b * Object color in the color system (L * value, a * value, b * value and saturation) were measured using a colorimeter 。

[0305] Also, Reference Example 12-1 of 6 For each composite ceramic, the fluorescent power was measured before and after annealing, and the ratio of the maximum fluorescent power after annealing to the maximum fluorescent power before annealing was determined. For example, in the case of Reference Example 12, this ratio is the ratio of the maximum fluorescent power after annealing to the saturated fluorescent power before annealing, as shown in FIG. 28. Also, for Reference Example 13, this ratio is the ratio of the saturated fluorescent power after annealing to the saturated fluorescent power before annealing, as shown in FIG. 29. The results are shown in Table 3. In the table, "Ba258" means "(Ba 0.6 Sr 0.4 )2Si5N8" and "CASN" stands for " CaAlSiN 3" and "YAG" stands for Ce-activated "Y3Al5O 12 " represents.

[0306] [Table 3]

[0307] As shown in Table 3, the fluorescent power is further increased by annealing in an ammonia atmosphere. Furthermore, as shown in Figures 28 and 29, the fluorescent power after annealing tends to reach saturation with the excitation light power compared to before annealing. This shows that the annealing also increases the tolerance to excitation light power.

[0308] [Reference example 17] The composite ceramic of Reference Example 8 was annealed by heating at 1150°C for 3 hours in a nitrogen atmosphere to obtain the composite ceramic of Reference Example 17. The composite ceramic of Reference Example 17 turned white, and no fluorescence was observed.

[0309] When phosphor is sintered in a nitrogen atmosphere, , Aya The internal quantum efficiency Also low This is thought to be due to the loss of nitrogen in the composition or the deactivation of the activator. In both the ternary system (two phosphor components and a matrix component) and the binary system (one phosphor component and a matrix component), the fluorescence intensity was further improved by annealing the sintered phosphor in an ammonia atmosphere.

[0310] 〔evaluation〕 The thermal conductivity was measured for each of the composite ceramics of Examples 16 to 18 and Reference Examples 7, 8, and 11. The Vickers hardness was also measured for each of the composite ceramics of Examples 16 to 18 and Reference Examples 7, 8, and 11. The results are shown in Table 4 below.

[0311] [Table 4]

[0312] In the ternary system, both the thermal conductivity and Vickers hardness tend to increase as the amount of matrix increases. In the binary system, both the thermal conductivity and Vickers hardness tend to be sufficiently high. In the binary system results, both the thermal conductivity and Vickers hardness tend to decrease depending on the degree of sintering.

[0313] [Example of phosphor element] Phosphor element A and phosphor element B were prepared using the composite ceramic of Example 18. Phosphor element A was prepared by forming a mirror body on one main surface of the 100 μm thick composite ceramic of Example 21, and bonding the composite ceramic to a copper alloy substrate on the mirror body side with an inorganic adhesive. Phosphor element B was prepared in the same manner as phosphor element A, except that the thickness of the composite ceramic of Example 18 was 50 μm.

[0314] FIG. 30 shows the relationship between the excitation light power and the fluorescent light power when the composite ceramic is irradiated with laser light for each of phosphor element A and phosphor element B.

[0315] In both phosphor element A and phosphor element B, the fluorescent power also increases as the excitation light power increases. Compared to phosphor element A, phosphor element B increases its fluorescent power more as the excitation light power increases. Compared to phosphor element A, phosphor element B converts the excitation light power into fluorescent power more appropriately, and therefore, in Example 18 It can be seen that the composite ceramics emit fluorescence efficiently even though they are thin.

[0316] [Durability] The phosphor element of the present invention was prepared, and the fluorescent power was measured when it was continuously irradiated with laser light. The results are shown in FIG.

[0317] The present disclosure 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 disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Explanation of symbols]

[0318] 1, 11, 12, 21, 31 Composite ceramics 2. Garnet-based phosphor components 3. Nitride-based phosphor components 4 Matrix Components 12 Light scattering component 22 First ceramic layer 23 Second ceramic layer 31a Unevenness 50 Phosphor element 51 Base material 60 Laser lighting device 61 Laser light source 62, 63 Lenses

Claims

1. A composite ceramic comprising a sintered body containing a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component, The matrix components are MgO and Al ２ O ３ At least one selected from the group consisting of the content of the matrix component is within the range of 31 wt % or more and 95 wt % or less of all components, the matrix component is sintered to surround the garnet-based phosphor component and the nitride-based phosphor component, the garnet-based phosphor component contains at least one selected from the group consisting of (Ce,Y)3Al5O12, (Ce,Lu)3Al5O12, (Ce,Lu,Y)3Al5O12, and (Ce,Lu,Y)3(Al,Ga)5O12; The composite ceramics is characterized in that the nitride-based phosphor component contains at least one selected from the group consisting of Sr2Si5N8, (Sr,Ba)2Si5N8, (Ca,Sr,Ba)2Si5N8, CaAlSiN3, (Ca,Sr)AlSiN3, (La)3Si6N11, (La,Y)3Si6N11, and (La,Y,Lu)3Si6N11, each activated with at least one element of Eu and Ce.

2. 2. The composite ceramic according to claim 1, wherein the number average particle size of the matrix component contained per unit volume of the composite ceramic is in the range of 0.01 μm or more and 10 μm or less.

3. At least one of a portion of the Si and a portion of the N is substituted, When a part of the Si is substituted, the Si is substituted with Al, 2. The composite ceramic according to claim 1, wherein when a portion of the N is substituted, the N is substituted with O.

4. In a ternary diagram in which the total content of the nitride-based phosphor component, the matrix component, and the garnet-based phosphor component is 100 wt %, the respective contents of the nitride-based phosphor component, the matrix component, and the garnet-based phosphor component are as follows: Point A, where the content of the nitride-based phosphor component is 59 wt %, the content of the matrix component is 31 wt %, and the content of the garnet-based phosphor component is 10 wt %; Point B, where the content of the nitride-based phosphor component is 8 wt %, the content of the matrix component is 90 wt %, and the content of the garnet-based phosphor component is 2 wt %; Point C, where the content of the nitride-based phosphor component is 2 wt %, the content of the matrix component is 90 wt %, and the content of the garnet-based phosphor component is 8 wt %; The composite ceramic according to claim 1, characterized in that the content of the nitride-based phosphor component is 10 wt %, the content of the matrix component is 31 wt %, and the content of the garnet-based phosphor component is 59 wt %. The composite ceramic is within a range surrounded by a straight line connecting point D, where point D is a point where the content of the nitride-based phosphor component is 10 wt %, a point D is a point D, and the content of the garnet-based phosphor component is 59 wt %.

5. Further comprising a light-scattering component having a refractive index higher than that of the matrix component by 0.21 or more, 2. The composite ceramic according to claim 1, wherein the total content of said matrix component and said light scattering component is 31 wt % or more and 95 wt % or less of all components.

6. 6. The composite ceramic according to claim 5, wherein the light scattering component is at least one selected from the group consisting of AlN, cBN, SiC, an AlN--SiC solid solution, and diamond.

7. 6. The composite ceramic according to claim 5, wherein the number average particle size of the light scattering component contained per unit volume of the composite ceramic is 0.25 μm or more and 40 μm or less.

8. 2. The composite ceramic according to claim 1, wherein the in-line transmittance of light with a wavelength of 450 nm at a thickness of 100 μm is 0.01% or more and 20% or less.

9. further comprising a sintering aid; The sintering aid is The matrix component is Al ２ O ３ If Si ３ N ４ , SiO ２ , CaO, MgO, ZnO and Y ２ O ３ At least one selected from the group consisting of The matrix component is MgO and Al ２ O ３ When at least MgO is contained, Si ３ N ４ , SiO ２ , CaO, ZnO and Y ２ O ３ 2. The composite ceramic according to claim 1, wherein the composite ceramic is at least one selected from the group consisting of:

10. On one main surface, MgO and Al ２ O ３ 2. The composite ceramic according to claim 1, having a laminated structure in which layers made of at least one material selected from the group consisting of:

11. Excitation light power tolerance is 0.5 kW / cm ２ 2. The composite ceramic according to claim 1, wherein:

12. 2. The composite ceramic according to claim 1, wherein one of the main surfaces has an uneven surface.

13. The composite ceramic according to any one of claims 1 to 12, A phosphor element comprising a substrate for fixing the composite ceramic.

14. The phosphor element according to claim 13; a laser light source that irradiates the composite ceramic in the phosphor element with excitation light; a light-collecting member for collecting light output from the composite ceramic of the phosphor element.

15. a mixing step of mixing a first raw material powder containing a garnet-based phosphor component, a nitride-based phosphor component, and a matrix component; a first raw material powder containing step of containing the mixed first raw material powder in a molding die; a sintering step of sintering the first raw material powder contained in the molding die by a spark plasma sintering method or a hot press method; and a demolding step of removing the sintered body obtained in the sintering step from the molding die, the garnet-based phosphor component contains at least one selected from the group consisting of (Ce,Y)3Al5O12, (Ce,Lu)3Al5O12, (Ce,Lu,Y)3Al5O12, and (Ce,Lu,Y)3(Al,Ga)5O12; A method for producing a composite ceramic, characterized in that the nitride-based phosphor component contains at least one selected from the group consisting of Sr2Si5N8, (Sr,Ba)2Si5N8, (Ca,Sr,Ba)2Si5N8, CaAlSiN3, (Ca,Sr)AlSiN3, (La)3Si6N11, (La,Y)3Si6N11, and (La,Y,Lu)3Si6N11, each activated with at least one element of Eu and Ce.

16. MgO and Al ２ O ３ the method further comprises a second raw material powder containing step of containing, into the molding die, second raw material powder that is less than the first raw material powder and that consists of at least one type selected from the group consisting of:

16. The method for producing a composite ceramic according to claim 15, wherein in the sintering step, the first raw material powder and the second raw material powder contained in the molding die are sintered to form a sintered body in which a sintered body of the first raw material powder and a sintered body of the second raw material powder that is thinner than the first raw material powder are joined together.

17. 16. The method for producing a composite ceramic according to claim 15, further comprising a cutting / polishing step of subjecting the sintered body to at least one of cutting and polishing.

18. 16. The method for producing a composite ceramic according to claim 15, further comprising a step of forming irregularities on one main surface of the sintered body.

19. 19. The method for producing a composite ceramic according to claim 18, wherein the unevenness is formed by using a dicer, laser processing, or polishing in the unevenness forming step.

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