WO2021079793A1 - Ceramic composite and production method for ceramic composite - Google Patents

Abstract

[Problem] To provide: a ceramic composite that can have a reduced size or thickness, and can efficiently dissipate heat; and a production method for the ceramic composite. [Solution] This ceramic composite is produced by: a step for preparing a melt comprising at least aluminum oxide and yttrium oxide; a step for bringing either sapphire crystal or ruby crystal into contact with the melt to melt a crystal portion thereof which is in contact with the melt, and to, as a result of the melting, integrate an Al₂O₃ phase of the crystal and an Al₂O₃ phase of the aluminum oxide together without a junction interface thereof; and a step for cooling the melt. The produced ceramic composite has at least two oxide phases, i.e., a Y₃Al₅O₁₂ phase and an Al₂O₃ phase, as a lamellar structure, wherein an Al₂O₃ phase, and an Al₂O₃ phase of either the sapphire crystal or the ruby crystal, are integrated together without a junction interface thereof.

Description

Ceramic composite and method for manufacturing ceramic composite

The present invention relates to a ceramic complex and a method for producing a ceramic complex.

Currently, a light emitting diode (LED: Light Emitting Diode) or a semiconductor laser that emits blue light is used as a light source, and a part of the blue light is wavelength-converted to yellow light by a wavelength conversion member, and a mixture of blue light and yellow light is used. Lighting devices that irradiate white light are widespread. In such lighting apparatus, using a _{YAG (Y 3 Al 5 O 12} ) based phosphor material of the wavelength conversion member, which is containing a phosphor powder in a resin or glass is proposed.

Further, Patent Documents 1 _{and 2 propose a ceramic composite having a lamellar structure in which the Y 3} Al ₅ O ₁₂ phase and the Al 2 O ₃ phase are continuously three-dimensionally entangled with each other as eutectic. The ceramic composite according to such Patent Documents 1 and _2, the blue light in Y ₃ Al _{5 O 12} phase with wavelength conversion into yellow _light, of Y ₃ Al _{5 O 12} phase and the _Al 2 _{O 3} phase Blue light and yellow light are scattered at the interface, and white can be obtained by mixing colors.

Japanese Patent No. 4609319 Japanese Patent No. 5246376

The YAG of the ceramic composite has a thermal conductivity of only about one-fourth that of sapphire, for example, and tends to generate heat more easily than a crystal material (for example, the sapphire crystal) conventionally used for lighting devices such as LEDs. There is. Therefore, when the ceramic composite is made thicker, the amount of heat generated increases and the heat dissipation property deteriorates. Therefore, the ceramic composite used for a lighting device or the like is required to be miniaturized or thinned.

On the other hand, various shapes are required for lighting equipment depending on the application. In order to secure the degree of freedom in shape design, the ceramic composite incorporated in the lighting device is required to be miniaturized or thinned.

However, as the ceramic complex becomes smaller or thinner, the transmission of blue light concentrates on a specific part of the ceramic complex. Further, a large amount of light is required depending on the application of the lighting device. Therefore, as the ceramic composite becomes smaller or thinner, heat is more likely to be generated from the ceramic composite, and the heat generating portion is concentrated on a specific portion of the ceramic composite, which causes a failure or malfunction of the lighting device.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a ceramic composite capable of achieving miniaturization or thinning and efficiently dissipating heat, and a method for producing the same.

The above object is achieved by the following invention. That is, the ceramic composite of the present invention has at least _{two oxide phases of Y 3} Al ₅ O ₁₂ phase and Al ₂ O ₃ phase as a lamellar structure, and also has Al ₂ O ₃ phase and sapphire crystal or ruby crystal. _{It is characterized in that the Al 2} O ₃ phases of any of the crystals are integrated with each other without a bonding interface.

Further, the ceramic composite of the present invention is provided with at least two crystals, and is sandwiched between the two crystals to _{form an Al 2} O ₃ phase of the _{crystal and an Al 2} O ₃ phase of the ceramic composite. It is characterized in that it is integrated with each other without a bonding interface.

Further, the ceramic composite of the present invention is characterized in that the gap between the crystals in which the ceramic composite is sandwiched is 0.01 mm or more and 1 mm or less.

Further, in the ceramic composite of the present invention, a stop hole or a through hole is formed in the crystal, and the ceramic composite is inserted into the stop hole or the through hole, so that the Al ₂ O ₃ phase of the crystal and the ceramic composite are formed. It is characterized in that the Al ₂ O ₃ phases of the body are integrated with each other without a bonding interface.

Further, the ceramic composite of the present invention is characterized in that the diameter of the stop hole or the through hole is 0.1 mm or more and 3 mm or less.

Further, the method for producing a ceramic composite of the present invention includes a step of preparing a melt composed of at least aluminum oxide and yttrium oxide, and contacting a crystal of either sapphire crystal or ruby crystal with the melt to form a melt. to melt the the contacted crystalline portion, and Al ₂ O ₃ phase of the crystal, and a step of integrating the bonding interface without each other by melting the Al ₂ O ₃ phase of aluminum oxide, in that it has a step of cooling the melt It is a feature.

Further, the method for producing a ceramic composite of the present invention includes a step of preparing at least two crystals and stacking them on each other, a step of putting a raw material containing at least aluminum oxide and yttrium oxide into the crucible, and a step of heating the crucible. The process of melting the raw material in a crucible to prepare a melt, and the process of bringing the crystals into contact with the melt and allowing the melt to infiltrate into the gaps between the overlapping crystals by capillarity, sandwiching the melt between the crystals. is brought into contact with the melt, to melt the crystalline portion in contact with the melt, and Al ₂ O ₃ phase of the crystal, and a step of integrating without bonding interface to each other by melting the Al ₂ O ₃ phase of aluminum oxide, It is characterized by further having a step of taking out the crystal from the melt and cooling the melt integrated with the crystal.

Further, the method for producing a ceramic composite of the present invention is characterized in that the gap between crystals is 0.01 mm or more and 1 mm or less.

Further, the method for producing a ceramic composite of the present invention is characterized in that the longitudinal direction of the gap between crystals is orthogonal to the plane direction of the liquid surface of the melt.

Further, the method for producing a ceramic composite of the present invention includes a step of forming a stop hole or a through hole in a crystal, and a stop in which the melt is infiltrated into the stop hole or the through hole by a capillary phenomenon and brought into contact with the melt. to melt the crystalline portion in the hole or through hole, and wherein the Al ₂ O ₃ phase of the crystal, further comprising the step of bonding interface are integrated without each other by melting the Al ₂ O ₃ phase of aluminum oxide.

Further, the method for producing a ceramic composite of the present invention is characterized in that the diameter of a stop hole or a through hole is 0.1 mm or more and 3 mm or less.

According to the ceramic composite and the method for producing a ceramic composite according to the present invention, it is possible to achieve miniaturization or thinning, and to realize a ceramic composite capable of efficiently dissipating heat, and such a ceramic composite. The body can be manufactured.

(a) It is a front view which shows typically an example of the ceramic complex which concerns on embodiment of this invention. (b) It is a bottom view of FIG. 1 (a). (c) It is a right side view of FIG. 1 (a). It is a perspective view of FIG. (a) It is a front view schematically showing another example of the ceramic complex which concerns on embodiment of this invention. (b) It is a bottom view of FIG. 3 (a). (c) It is a right side view of FIG. 3 (a). It is an enlarged view of the circle A portion in FIG. It is a perspective view schematically showing still another example of the ceramic complex which concerns on embodiment of this invention. It is explanatory drawing which shows typically the process of the manufacturing method of the ceramic complex which concerns on embodiment of this invention. It is explanatory drawing which shows typically another process of the manufacturing method of the ceramic complex which concerns on embodiment of this invention. It is a side view which shows typically the ceramic composite which concerns on embodiment of this invention manufactured through the process of FIG. 6 and FIG. It is a schematic block diagram which shows the manufacturing apparatus which manufactures the ceramic composite which concerns on embodiment of this invention. It is a micrograph which shows the cross section of the ceramic complex manufactured by the manufacturing method which concerns on this invention. It is a perspective view schematically showing still another example of the ceramic complex which concerns on embodiment of this invention. It is a side view which shows typically the state in which the ceramic complex and the crystal of FIG. 11 are laminated. It is a side view which shows typically the state in which the ceramic composite of FIG. 12 was melted and resolidified. It is a perspective view schematically showing still another example of the ceramic complex which concerns on embodiment of this invention. FIG. 6 is a side view schematically showing a state in which the ceramic complex and crystals of FIG. 14 are laminated. FIG. 5 is a side view schematically showing a state in which the ceramic composite of FIG. 15 is melted and resolidified. It is a schematic block diagram which shows the manufacturing apparatus of the ceramic complex by the EFG method. (a) It is a top view which shows typically an example of the die which concerns on embodiment of this invention. (b) It is a front view of FIG. 18 (a). (c) It is a side view of the figure (a). (a) It is explanatory drawing which shows an example of the seed crystal which concerns on embodiment of this invention. (b) It is explanatory drawing which shows the other example of the seed crystal which concerns on embodiment of this invention. (c) It is explanatory drawing which shows still another example of the seed crystal which concerns on embodiment of this invention. It is a perspective view which shows typically the positional relationship between a seed crystal and a partition plate in embodiment of this invention. (a) It is a front view schematically showing the positional relationship between the seed crystal and the partition plate in the embodiment of the present invention. (b) It is a front view which shows the state of melting a part of a seed crystal in embodiment of this invention. (a) In the seed crystal according to the embodiment of the present invention, it is explanatory drawing which shows the seed crystal which the lower side has the shape of a comb tooth. (b) It is explanatory drawing which shows the seed crystal which the lower side has a saw shape in the seed crystal which concerns on embodiment of this invention. It is a perspective view which shows typically the spreading process of the ceramic complex which concerns on embodiment of this invention. FIG. 5 is a perspective view partially showing a plurality of ceramic complexes according to an embodiment of the present invention obtained by the EFG method. It is a perspective view which shows another form of the growth process of the ceramic complex by the EFG method.

The first feature of this embodiment is that it has at least _{two oxide phases of Y 3} Al ₅ O ₁₂ phase and Al ₂ O ₃ phase as a lamella structure, and also has Al ₂ O ₃ phase and a sapphire crystal or a ruby crystal. _{The Al 2} O ₃ phases of any of the crystals are integrated into a ceramic composite having no bonding interface with each other.

The second feature of the present embodiment is the step of preparing a melt composed of at least aluminum oxide and yttrium oxide, and contacting either a sapphire crystal or a ruby crystal with the melt to bring it into contact with the melt. crystal portions to melt, and Al ₂ O ₃ phase of the crystal, and a step of integrating the bonding interface without each other by melting the Al ₂ O ₃ phase of aluminum oxide, the ceramic composite having a step of cooling the melt It was a manufacturing method. Only the crystal part that comes into contact with the melt is melted, and the other crystal parts are not melted.

A third feature of the present embodiment, together with the crystal are provided at least two, are sandwiched by the two crystals, and Al ₂ O ₃ phase of the crystal, Al ₂ O ₃ phase of the ceramic composite However, it is a ceramic composite that is integrated without a bonding interface.

The fourth feature of the present embodiment is a step of preparing at least two crystals and stacking them on top of each other, a step of putting a raw material containing at least aluminum oxide and yttrium oxide into the pit, and a step of heating the pit to prepare the raw material. The process of melting in a pit to prepare a melt, and the crystals are brought into contact with the melt, and the melt is infiltrated into the gaps between the overlapping crystals by a capillary phenomenon, and the melt is sandwiched between the crystals to melt the crystals. contacting the liquid, to melt the crystalline portion in contact with the melt, and Al ₂ O ₃ phase of the crystal, and a step of integrating the bonding interface without each other by melting the Al ₂ O ₃ phase of aluminum oxide, the crystal This is a method for producing a ceramic composite having a step of removing the melt from the melt and cooling the melt integrated with the crystals.

The fifth feature of the present embodiment is that a stop hole or a through hole is formed in the crystal, and a ceramic complex is inserted into the stop hole or the through hole to form an Al ₂ O ₃ phase of the crystal and ceramic. The Al ₂ O ₃ phases of the complex are integrated into a ceramic complex without a bonding interface.

The sixth feature of the present embodiment is a step of forming a stop hole or a through hole in the crystal, and a stop hole or a stop hole in which the melt is infiltrated into the stop hole or the through hole by a capillary phenomenon and brought into contact with the melt. to melt the crystalline portion of the through hole, and the Al ₂ O ₃ phase of the crystal, the method for producing a ceramic composite body further comprising a step of bonding interface are integrated without each other by melting the Al ₂ O ₃ phase of aluminum oxide It is a thing.

According to these configurations and the manufacturing method, the Al ₂ O ₃ phase of either crystal sapphire crystal or ruby crystal, Al ₂ O ₃ phase with each other directly of the ceramic composite, there is no mutually bonding interface by the molten state It is formed by being integrated with. Therefore, even if heat is generated from the ceramic composite, the heat is quickly conducted to the crystal, so that a ceramic composite capable of efficiently dissipating heat can be realized.

Furthermore, since the Al ₂ O ₃ phases are integrated with each other without a bonding interface, the Al ₂ O ₃ phases are firmly bonded to each other to prevent separation, and the ceramic joint also has high impact resistance. Can be given and reliability is improved.

Furthermore, by entering the melt in the crystal by capillary action, quickly it becomes possible to produce ceramic composite integral with Al ₂ O ₃ phase of the crystal, thereby improving mass productivity.

The seventh feature of the present embodiment is that the ceramic composite has a gap of 0.01 mm or more and 1 mm or less between crystals sandwiching the ceramic composite.

The eighth feature of this embodiment is that the method for producing a ceramic complex has a gap between crystals of 0.01 mm or more and 1 mm or less.

The ninth feature of this embodiment is that the diameter of the stop hole or through hole is 0.1 mm or more and 3 mm or less as a ceramic composite.

The tenth feature of the present embodiment is that the diameter of the stop hole or the through hole is 0.1 mm or more and 3 mm or less as a method for manufacturing a ceramic composite.

According to these configurations and manufacturing methods, in addition to the above-mentioned effects, it is possible to achieve miniaturization or thinning of the ceramic composite. Further, as the ceramic complex becomes smaller or thinner, heat is generated from the ceramic complex, and even if the heat generating portion is concentrated on a specific part of the smaller or thinner ceramic composite, the Al ₂ O ₃ phases are generated. Since they are directly fused and integrated without a bonding interface, heat is quickly dissipated.

Furthermore, since the melt can be uniformly infiltrated into the gaps between crystals, the stop holes, or the through holes by the capillary phenomenon, unevenness in the thickness of the ceramic complex is prevented, and uniform white light is obtained over the entire in-plane. Things will be possible.

The eleventh feature of the present embodiment is that the method for producing a ceramic complex is such that the longitudinal direction of the gap between the crystals is orthogonal to the plane direction of the liquid surface of the melt.

According to this manufacturing method, in addition to the above effects, the capillary phenomenon can be performed most quickly.

Hereinafter, the ceramic complex according to the first embodiment of the present invention and the method for producing the same will be described with reference to FIGS. 1 to 10.

As shown in FIGS. 1 to 5, the ceramic composite 2 according to the present invention has at least _{two oxide phases, Y 3} Al ₅ O ₁₂ phase and Al ₂ O ₃ phase, as a lamella structure, and Al _{2 thereof.} and O ₃ phase, either crystalline 6 or 9 Al ₂ O ₃ phase of the sapphire crystal or ruby crystals are integrated in a state bonded interface is not another.

FIG. 10 is a photomicrograph showing a cross section of the ceramic complex 2. As shown in FIG. 10, the ceramic composite 2 of the present embodiment has at least two oxides of _{a YAG (Y 3} Al ₅ O ₁₂ ) phase, which is the first phase, and an Al ₂ O _{3 phase, which is the second phase.} It is a solidified body having a lamellar structure in which the phases exist as eutectics and the first and second phases are continuously and sterically entwined with each other.

The structure of the lamellar structure in which the two oxide phases of the first phase and the second phase are continuously and three-dimensionally entangled with each other is oxidized because there is no boundary phase such as amorphous between each oxide phase. It is an organization in which physical phases are in direct contact with each other. In FIG. 10, the region shown in dark color (black portion) is the Y ₃ Al ₅ O ₁₂ phase, and the region shown in light color (white portion) is the Al ₂ O ₃ phase. The first phase and the second phase are rarely separated in an island shape independently, and have continuous regions in the three-dimensional direction (three-dimensional direction). Further, when the obtained solidified ceramic complex 2 was confirmed with the naked eye of the manufacturer, it was yellow.

_{The composition ratio of the Y 3} Al ₅ O ₁₂ phase contained in the ceramic complex 2 is 19.72 ± 2.00 mol% in the vicinity of the eutectic composition. If _{the composition ratio of the Y 3} Al ₅ O ₁₂ phase is out of this range, it is difficult to uniformly form a lamellar structure by eutectic _{with the Al 2} O _{3 phase.}

Further, it is more desirable to contain Ce in the Y ₃ Al ₅ O _{12 phase.} The reason is that the Y of the Y ₃ Al ₅ O ₁₂ phase is partially replaced by Ce, so that the Y ₃ Al ₅ O ₁₂ phase functions as a phosphor material and absorbs blue light, which is the primary light. This is because the yellow light of the secondary light is emitted and the white light can be obtained.

The content of Ce in the Y ₃ Al ₅ O ₁₂ phase is preferably in the range of 0.01 mol% or more and 5.0 mol% or less. By Y ₃ Al ₅ O ₁₂ phase of Y is substituted partially _Ce, Y ₃ Al _{5 O 12} phase functions as a phosphor material, the secondary light by absorbing blue light is the primary light It emits yellow light. In the Y ₃ Al ₅ O ₁₂ phase, the absorption wavelength and the emission wavelength change depending on the Ce concentration, but the ceramic composite of the present embodiment has a uniformly fine lamellar structure even if the Ce content is relatively high, as will be described later. Can be formed.

_{Here, the Y 3} Al ₅ O ₁₂ phase activated by Ce is shown as the first phase, but a part of Y may be replaced with Lu. Substitution amount of Lu is possible to set the above 1.0 mol% 10.0 mol% or less is preferable in terms of Y ₃ Al ₅ O ₁₂ phase emits yellow light of the secondary light by absorbing blue light is the primary light .. Further, when a part of Y is replaced with Lu, the Y ₃ Al ₅ O ₁₂ phase may be activated in the range of 0.01 mol% or more and 5.0 mol% or less in Ce.

Cr may also be added to the ceramic complex. The amount to be added can be arbitrarily selected, but for example, when it is desired to emit red fluorescent light from the ceramic complex, 0.01 mol% or more and 0.5 mol% or less is desirable.

Further, the ceramic complex 2 contains MgO in the range of 10 ppm or more and 500 ppm or less. By containing MgO in this range, the conversion efficiency from blue light to white light can be enhanced, and the emission intensity of white light can be increased.

Further, in the ceramic complex 2 of the present embodiment, in the lamellar structure of _{the Y 3} Al ₅ O ₁₂ phase and the Al ₂ O _{3 phase, the average value of the lamellar intervals in the Y 3} Al ₅ O ₁₂ phase is 0.5 μm or more and 20 μm or less. is there. Here _Y 3 The _Al 5 lamellar spacing _{O 12} phase, and the width of the _Y 3 _Al 5 _{O 12} phase sandwiched _Al 2 _{O 3} phase, longitudinal continuous _Y 3 _Al 5 _{O 12} phase Shows the width across. If lamellar spacing is less than 0.5μm, the size of Y ₃ Al ₅ O ₁₂ phase becomes several times the wavelength of blue light, uniformly turned blue light into difficult to wavelength-converted into yellow light It ends up. Further, when the lamellar spacing is larger than 20 μm, the lamellar structure becomes insufficiently dense, and the interface _{between the Y 3} Al ₅ O ₁₂ phase and the Al ₂ O _{3 phase is performed while blue light is transmitted through the ceramic composite 2.} The number of times the light is incident on the surface is reduced, the light is not sufficiently scattered, and the efficiency of wavelength conversion and color mixing is reduced.

Further, the ceramic complex 2 is manufactured by using a crucible 5 (see FIG. 9) described later. Therefore, the raw material melt in which molybdenum (Mo) or tungsten (W), which is the material of the crucible 5, melts the raw material of the ceramic composite 2 in the crucible 5 (hereinafter, simply referred to as “melt” if necessary). In 17, it dissolves in a small amount and is incorporated into the ceramic composite 2. Therefore, the ceramic complex 2 contains a small amount of Mo or W in addition to the _{Y 3} Al ₅ O ₁₂ phase and the Al ₂ O _{3 phase, MgO, Ce, and Lu and Cr.}

The amount of Mo or W contained in the ceramic composite 2 is preferably in the range of 1.0 mol · ppm or more and 30,000 mol · ppm or less, and more preferably in the range of 100 mol · ppm or more and 3000 mol · ppm or less. In the production of the ceramic complex 2 using the EFG (Edge-defined Film-fed. Growth) method, it is impossible to completely prevent the material of the crucible 5 from dissolving in the melt 17, and Mo or W. It is very difficult to make the content of the crucible less than 1.0 mol · ppm. Further, if the Mo or W content is increased to exceed 30,000 mol · ppm, _{the crystallinity of the Y 3} Al ₅ O ₁₂ phase and the Al ₂ O ₃ phase deteriorates, and the wavelength conversion efficiency deteriorates, which is not preferable. When the Mo or W content is set to 100 mol · ppm or more and 3000 mol · ppm or less, these problems can be solved and the amount of white light emitted can be increased by uniformly scattering the primary light and the secondary light. Therefore, it is the most desirable. Therefore, by setting the content of Mo or W contained in the ceramic composite 2 to at least 1.0 mol · ppm or more and 30,000 mol · ppm or less, a fine lamellar structure is formed to uniformly scatter light, and the emission intensity is increased. Uniformity and conversion efficiency can be improved.

When a material other than Mo or W is used for the crucible 5, the amount of the material of the crucible 5 dissolved in the melt 17 increases because the melting point is low, and the element content derived from the crucible 5 contained in the ceramic complex 2 increases. It is not preferable because it does. Further, it is not preferable to use a material having a high melting point other than Mo or W as the material constituting the crucible 5 because there are problems such as reactivity with the melt 17 of the raw material and moldability of the crucible 5. Therefore, in order to manufacture the ceramic complex 2 and _{refine the lamellar structure of the Y 3} Al ₅ O ₁₂ phase and the Al ₂ O ₃ phase, Mo or W is contained in the ceramic complex 2 in the above range. Things are important.

As described above, the ceramic composite 2 of the present embodiment has at least _{two oxide phases of Y 3} Al ₅ O ₁₂ phase and Al ₂ O ₃ phase as a lamellar structure, and Y ₃ Al ₅ O ₁₂ The average value of the lamellar spacing in the phase is 0.5 μm or more and 20 μm or less, and MgO is contained in an amount of 10 ppm or more and 500 ppm or less. Further, since Mo or W is contained, it is possible to uniformly scatter the primary light and the secondary light to improve the wavelength conversion efficiency.

In the ceramic complex 2 of the present embodiment, the Ce content is adjusted in the range of 0.01 mol% or more and 5.0 mol% or less as described above. Therefore, the lamellar structure contains _{the interfaces of the Y 3} Al ₅ O ₁₂ phase and the Al ₂ O ₃ phase at a density of 30 pieces / mm or more and 800 pieces / mm or less. If the number of interfaces is less than 30 / mm, the lamellar structure is not sufficiently dense, and the interface between the Y ₃ Al ₅ O ₁₂ phase and the Al ₂ O ₃ phase while blue light is transmitted through the ceramic composite 2 The number of times the light is incident on the surface is reduced, the light is not sufficiently scattered, and the efficiency of wavelength conversion and color mixing is reduced. If the interface is greater than 800 / mm, since the size of Y ₃ Al ₅ O ₁₂ phase becomes several times the wavelength of the smaller becomes the blue light, uniformly possible to wavelength convert blue light into yellow light May become difficult.

As the crystal integrated with such a ceramic complex 2, two crystals are provided as shown in FIGS. 1 to 4 (crystals 6 and 6), or a pipe-shaped crystal 9 shown in FIG. 5 is provided. There is. A stop hole or a through hole is formed in the crystal 9 of FIG. Note that FIG. 5 illustrates an embodiment having a through hole 9a.

In the embodiment in which two flat plate-shaped crystals 6 are provided as shown in FIGS. 1 to 4, the surfaces of the crystals 6 are joined by direct contact without using an adhesive or a joining material.

The melt 17 is infiltrated into the minute gaps between the bonded surfaces of the crystals 6 to be bonded by a capillary phenomenon described later, and is sandwiched between the two crystals (6, 6). _{Therefore, the Al 2} O ₃ phase of the ceramic complex 2 _{is integrated with the Al 2} O ₃ phase of the crystal 6 on both sides thereof without a bonding interface. The gap between the crystals (6, 6) in which the ceramic composite is sandwiched is set to 0.01 mm or more and 1 mm or less.

If the gap between the crystals (6, 6) is less than 0.01 mm, the ceramic complex 2 formed in the gap is excessively thinned, so that the influence of the thickness due to the manufacturing error and the influence of the thickness unevenness in the plane are affected. As the size increases, it becomes difficult to obtain white light uniformly over the entire in-plane area. On the other hand, since the thermal conductivity of the _{Y 3} Al ₅ O ₁₂ phase contained in the ceramic composite 2 is _{only about 1/4 of that of the Al 2} O ₃ phase, if the gap between the crystals (6, 6) becomes large, The ceramic composite 2 formed in the gap is also thickened, the heat dissipation is deteriorated, and a temperature difference between the surface and the inside is likely to occur. Therefore, when the gap between the crystals (6, 6) is larger than 3 mm, a temperature difference between the outside and the inside is likely to occur, which may impair the uniformity of the lamella spacing, which is not preferable. The desirable gap for preventing a temperature difference between the surface and the inside is 1 mm or less.

When it is desired to form a gap between crystals (6, 6) in the range of 0.01 mm to 1 mm, which is relatively large in the vicinity of 1 mm, the melt 17 is impregnated into the direct bonding surface between the crystals 6 by a capillary phenomenon to form the gap. Is formed, the gap between the direct joint surfaces is expanded as the melt 17 infiltrates. Therefore, it is not preferable because the bonded state cannot be maintained and peeling may occur. Therefore, as shown in FIG. 4, it is preferable to separately provide a slit with a step 6c on the joint surface with a width W and allow the melt 17 to penetrate into the slit to form the ceramic complex 2. The width W is a desired width of the ceramic complex 2 to be formed, and is less than the width of the crystal 6. The thickness of the slit due to the step 6c is such that the melt 17 that has penetrated into the slit is held in the slit by its surface tension and does not drip or drip out of the slit. The upper limit of the thickness of the slit may be 1 mm, which is the upper limit of the gap between the crystals (6, 6).

The size of the crystal 6 in the plane direction is not particularly limited, but from the viewpoint of preventing deterioration of workability, a square shape having a width of 0.5 mm or more and 300 mm or less and a length of 10 mm or more and 1000 mm or less is desirable.

On the other hand, as shown in FIG. 5, in the embodiment in which the pipe-shaped crystal 9 in which the stop hole or the through hole is formed is provided, the ceramic composite 2 is inserted into the stop hole or the through hole, and the ceramic composite 2 is inserted. and _Al 2 _{O 3} phase of the crystal 9, _Al 2 _{O 3} phase of the ceramic composite 2 are integrated in a state bonded interface is not another. Further, by setting the diameter of the stop hole or the through hole to 0.1 mm or more and 3 mm or less, the melt 17 can be infiltrated into the stop hole or the through hole by the capillary phenomenon.

If the diameter of the stop hole or through hole is less than 0.1 mm, the diameter of the ceramic composite 2 portion becomes too small, and it becomes difficult to obtain white light uniformly. On the other hand, if it exceeds 3 mm, the ceramic complex 2 becomes too thick, the heat dissipation property deteriorates, and the uniformity of the lamella spacing may be impaired, which is not preferable.

Although FIG. 5 shows an embodiment having a through hole 9a, it may be a stop hole. The diameter of the crystal 9 is not particularly limited as long as a stop hole or a through hole (hole 9a in FIG. 5) having a diameter of 0.1 mm or more and 3 mm or less can be formed.

Crystal 6 or 9 is composed of either sapphire crystal or ruby crystal. Examples of the crystal 6 or 9 include a single crystal, a polycrystal, and a crystal having an intermediate structure between them. However, since a single crystal has high thermal conductivity and high transparency, it is most preferable especially for lighting equipment applications.

As described above, according to the ceramic composite 2 according to the first embodiment of the present invention, the Al ₂ O ₃ phase of the crystal 6 or 9 of either the sapphire crystal or the ruby crystal and the Al 2 O of the ceramic composite _{2 The three} phases are directly integrated by melting, which will be described later, without a bonding interface. Therefore, even if heat is generated from the ceramic complex 2, the heat is quickly conducted to the crystals 6 or 9, so that the ceramic complex 2 capable of efficiently dissipating heat can be realized.

Furthermore, since the Al ₂ O ₃ phases are integrated with each other without a bonding interface, the Al ₂ O ₃ phases are firmly bonded to each other to prevent separation, and the ceramic bonded body 2 also has high impact resistance. Gender can be imparted and reliability is improved.

Further, the ceramic complex 2 is sandwiched between two crystals (6, 6) (0.01 mm or more and 1 mm or less) to reduce the thickness, or the crystal 9 has a stop hole or a through hole (diameter 0.1). It is inserted into (mm or more and 3 mm or less) to reduce the size (smaller diameter). Therefore, it is possible to achieve miniaturization or thinning of the ceramic composite 2.

Further, as the ceramic complex 2 becomes smaller or thinner, heat is generated from the ceramic complex 2, and even if the heat generating portion is concentrated on a specific portion of the smaller or thinner ceramic complex 2, the crystal (6 or) Since 9) and the Al ₂ O ₃ phases of the ceramic complex 2 are directly integrated by melting without a bonding interface, heat is quickly dissipated.

Therefore, even if the ceramic complex 2 is used for the lighting device, it is possible to prevent the lighting device from malfunctioning or malfunctioning.

Further, a method for producing the ceramic complex 2 according to the first embodiment of the present invention will be described with reference to FIGS. 6 to 9. As shown in FIG. 9, the manufacturing apparatus 1 of the ceramic complex 2 is composed of a crucible 5 as a container 3 for manufacturing the ceramic complex 2 and a pulling container 4.

The container 3 includes a crucible 5, a crucible drive unit 18, a heater 7, an electrode 8, and a heat insulating material 10. The crucible 5 is made of molybdenum (Mo) or tungsten (W) and melts the raw material of the ceramic complex 2. The crucible drive unit 18 rotates the crucible 5 about its vertical direction. The heater 7 heats the crucible 5. Further, the electrode 8 energizes the heater 7. The heat insulating material 10 surrounds the crucible 5 and the heater 7.

Further, the container 3 is provided with an atmospheric gas introduction port 11 and an atmospheric gas exhaust port 12. The atmosphere gas introduction port 11 is an introduction port for introducing, for example, argon gas as an atmosphere gas into the container 3, and prevents oxidative consumption of the crucible 5 and the heater 7. On the other hand, the exhaust port 12 is provided for exhausting the atmospheric gas in the container 3.

The pull-up container 4 includes a shaft 13, a shaft drive unit 14, a gate valve 15, and an entrance / exit 16 of the ceramic complex 2. The shaft 13 holds a separately prepared crystal 6. Further, the shaft drive unit 14 raises and lowers the shaft 13 toward the crucible 5, and rotates the shaft 13 about the raising and lowering direction. The gate valve 15 separates the container 3 and the pull-up container 4. Further, the entrance / exit 16 allows the ceramic composite according to the present invention to be taken in and out.

Next, the manufacturing process of the ceramic complex 2 using the manufacturing apparatus 1 will be described. As a first step, it contains granulated raw material powder (for example, 64.71% by weight of aluminum oxide, 35.02% by weight of yttrium oxide, 0.003% by weight of magnesium oxide, 0.27% by weight of cerium oxide, which is the raw material of the ceramic composite 2. A predetermined amount of powder) is added to the crucible 5 and filled. The raw material powder may contain compounds and elements other than the above depending on the purity or composition of the ceramic complex 2 to be produced, but at least aluminum oxide and yttrium oxide are contained.

Subsequently, in order not to oxidatively consume the crucible 5 and the heater 7, the inside of the container 3 is replaced with argon gas, and the oxygen concentration is set to a predetermined value or less.

As the next step, the raw material powder is melted by heating with the heater 7 to bring the crucible 5 to a predetermined temperature. The heating temperature of the crucible 5 is above the melting point of the ceramic composite 2 and below the melting point of aluminum oxide, sapphire crystals, or ruby crystals. Since the melting point of the ceramic complex 2 is about 1820 ° C. to 1870 ° C., the heating temperature of the crucible 5 is set to be about 50 ° C. higher than the melting point of the ceramic complex 2 as an example. The melting point of aluminum oxide, sapphire crystal, or ruby crystal is about 2050 ° C to 2072 ° C. When the crucible 5 is heated to such a temperature, the raw material powder is melted shortly after heating, and the raw material melt 17 (see FIG. 6) is prepared. The temperature of the melt 17 is set above the melting point of the ceramic composite 2 and below the melting point of aluminum oxide, sapphire crystals, or ruby crystals.

As the next step, the shaft 13 is lowered and the crystals are immersed in the melt 17 and brought into contact with each other. The crystals to be immersed in the melt 17 are either two crystals (6, 6) directly bonded to each other as described above, or a pipe-shaped crystal 9 shown in FIG. A stop hole or a through hole is formed in advance in the crystal 9 of FIG. 5 by drilling or the like. 6 to 9 show, as an example of the manufacturing method according to the present invention, the immersed state of the crystals (6, 6) directly bonded by the step of superimposing the flat crystal-shaped crystals 6 shown in FIGS. 1 to 4 in advance. Is shown.

FIG. 7 shows a state in which crystals (6, 6) are immersed in the melt 17, and a part of the melt 17 infiltrates into the gap 6b of the joint surface between the crystals 6 by capillary action. In FIGS. 6 to 8, the gap 6b is exaggerated for the sake of clarity. Due to the infiltration, a part of the melt 17 is sandwiched between the crystals (6, 6), and the melt 17 and the crystals (6, 6) are brought into contact with each other. The crystal 9 of FIG. 5 may be immersed in the melt 17, and the melt 17 may be immersed in the stop hole or the through hole by a capillary phenomenon to bring the melt 17 into contact with the crystal 9.

The crystalline portion in contact with the melt 17 is melted. _{The applicant has found that by concentrating the Al 2} O ₃ phase of the crystal 6 on the contact surface with the melt 17, only the contact surface is preferentially melted even if the temperature is lower than the melting point of the crystal 6. And _Al 2 _{O 3} phase of the crystal (6,6) by its melting, _Al 2 _{O 3} phase of aluminum oxide melt is integrated in a state bonded interface is not another. _{In the case of FIG. 7, the Al 2} O ₃ phase of aluminum oxide of the melt 17 is formed on the surfaces of the two crystals (6, 6) forming the gap 6b, the other surface in contact with the melt 17, and the end portion. Be integrated.

When the crystal 9 of FIG. 5 is immersed in the melt 17, the crystal portion in the stop hole or the through hole is melted by the temperature of the melt 17. And _Al 2 _{O 3} phase of the crystal (6,6) by its melting, _Al 2 _{O 3} phase of aluminum oxide melt is integrated in a state bonded interface is not another. Further, when the crystal 9 is immersed in the melt 17, the end of the crystal 9 in contact with the melt 17 and the side surface of the crystal 9 are also integrated with _{the Al 2} O _{3 phase of aluminum oxide of the melt 17.} ..

After that, the shaft 13 is raised to take out the crystal (6, 6) or 9 from the melt 17, and the melt 17 integrated with the crystal (6, 6) or 9 is cooled to cool the ceramic composite which is a solidified body. Form body 2. It is the ceramic composite 2 of the solidified body is formed, the crystal (6,6) or the _Al 2 _{O 3} phase 9, _Al 2 _{O 3} phase of the ceramic composite body 2, together with the state bonding interface is not mutually To be transformed.

After immersing the crystal in the melt 17, the crystal is immediately taken out from the melt 17 as soon as it is confirmed that the melt 17 has penetrated into the gap 6b of the joint surface, the stop hole or the through hole. Then, the melted portion of the crystal (6,6) or 9 is limited to the contact portion with the melt 17, and the heating of the crystal (6,6) or 9 as a whole is suppressed, and the crystal (6,6) or 9 is suppressed. When 9 is a single crystal in particular, it is possible to maintain the crystal structure in a single phase state, which is desirable.

After that, the obtained ceramic complex 2 is allowed to cool, the gate valve 15 is opened, the gate valve 15 is moved to the pull-up container 4, and the ceramic composite 2 is taken out from the doorway 16.

Since the ceramic complex integrated on the surface of the crystal (6, 6) or 9 is not required other than the ceramic complex 2 formed in the gap 6b or in the stop hole or through hole after being taken out from the doorway 16. It may be removed by polishing (see FIG. 8).

By controlling the temperature of the liquid surface of the melt 17 to be constant at the time of contact with the crystal, the crystal formation conditions of the ceramic composite 2 in the capillary phenomenon can be kept the same over the width direction, and the ceramic can be maintained. A uniform lamellar structure can be formed over the entire area of the complex 2.

As described above, in the present invention, it has been found that a capillary phenomenon occurs in the melt 17 of the ceramic composite 2. Therefore, by infiltrating the melt into the crystal by the capillary phenomenon, the Al ₂ O ₃ phase of the crystal is promptly generated. It has become possible to manufacture the ceramic composite 2 integrated with the above, and the mass productivity can be improved.

Further, due to the capillary phenomenon, the melt 17 can be uniformly infiltrated into the gap 6b of the joint surface between the crystals (6, 6) and the stop hole or through hole of the crystal 9, so that the thickness of the ceramic composite 2 can be increased. Unevenness is prevented, and uniform white light can be obtained over the entire in-plane of the ceramic composite 2.

Further, the longitudinal direction of the gap 6b between the crystals (6, 6) (the vertical direction of FIG. 7 or 8) is orthogonal to the surface direction of the liquid surface of the melt 17 (horizontal direction of FIG. 7 or FIG. 8). Then, the crystals (6, 6) are immersed in the liquid surface of the melt 17 in the vertical direction. Alternatively, the longitudinal direction of the stop hole or the longitudinal direction of the through hole is orthogonal to the surface direction of the liquid surface of the melt 17, and the stop hole or the through hole is immersed in the liquid surface of the melt 17 in the vertical direction. By such immersion, the capillary phenomenon can be performed most quickly.

Crystals 6 or 9 may be produced by using a known method. As the sapphire crystal and the ruby crystal, those grown and grown by the EFG method, the kilopros method, the Choclas Lucy method, the Verneuil method, the vertical Bridgeman method and the like are used.

Next, the ceramic complex according to the second embodiment of the present invention and the method for producing the same will be described with reference to FIGS. 11 to 25. In addition, the same withdrawal number is assigned to the part overlapping with the first embodiment, and the duplicated description will be omitted or simplified.

In the embodiment of FIGS. 11 to 13, two crystals (6, 6) are provided, a step 6c is provided only in the lower crystal 6, and the ceramic composite 2 is arranged in the step 6c to form a crystal (6). , 6) sandwiches the crystal (6, 6) Al ₂ O ₃ phase and the ceramic composite 2 Al ₂ O ₃ phase.

In the embodiments of FIGS. 11 to 13, the planar shapes of the two crystals (6, 6) are circular with each other having orifra, and the diameter is 1 inch (25.4 mm) to 8 inches (203.2 mm). The thickness is 1 mm. The height of the step 6c is 0.01 mm or more and less than the thickness of the crystal 6, and the width is less than the diameter of the crystal 6.

The embodiment of FIGS. 14 to 16 includes three crystals 6, and a through hole 6a is provided only in the middle crystal 6 which is sandwiched between the upper and lower crystals (6, 6) and has a relatively small diameter. .. The ceramic composite 2 is inserted or arranged in the through hole 6a and between the upper and lower crystals (6, 6) sandwiching the middle crystal 6, and the Al ₂ O ₃ phase of each of the three crystals 6 and the ceramic. _{The Al 2} O ₃ phase of the complex 2 is integrated.

The shape of the three crystals 6 in the plane direction is a circular shape having orientation flare with each other, and each is formed to a thickness of 1 mm. The diameters of the upper and lower crystals (6, 6) are 1 inch (25.4 mm) to 8 inches (203.2 mm), and only the diameter of the middle crystal 6 is set to be smaller than the diameter of the upper and lower crystals (6, 6). .. Further, the diameter of each through hole 6a is 0.1 mm or more and 3 mm or less. Further, each through hole 6a is formed in the middle crystal 6 in advance by drilling or the like.

Further, a method for producing the ceramic complex 2 according to each embodiment of FIGS. 11 to 16 will be described. First, a method for producing the ceramic complex 2 arranged in the crystal 6 in FIGS. 11 or 14 will be described with reference to FIGS. 17 to 25. 17 to 24 are views for explaining a method for producing a plurality of ceramic composites.

As shown in FIG. 17, the ceramic complex manufacturing apparatus 19 is composed of a container 20 for growing the ceramic complex 2 and a pulling container 4 for pulling up the grown ceramic complex 2, and the ceramic complex 2 is formed by the EFG method. Nurture and grow.

The container 20 includes a crucible 5, a crucible drive unit 18, a heater 7, an electrode 8, a die 22, and a heat insulating material 10. The crucible 5 is made of molybdenum or tungsten and melts the raw material. The crucible drive unit 18 rotates the crucible 5 about its vertical direction. The heater 7 heats the crucible 5. Further, the electrode 8 energizes the heater 7. The die 22 is installed in the crucible 5 and determines the liquid level shape of the raw material melt (hereinafter, simply referred to as “melt” if necessary) 17 when pulling up the ceramic complex 2. The heat insulating material 10 surrounds the crucible 5, the heater 7, and the die 22.

Further, the container 20 is provided with an atmosphere gas introduction port 11 and an exhaust port 12. The atmosphere gas introduction port 11 is an introduction port for introducing, for example, argon gas as an atmosphere gas into the container 20, and prevents oxidative consumption of the crucible 5, the heater 7, and the die 22. On the other hand, the exhaust port 12 is provided for exhausting the inside of the container 20.

The pull-up container 4 includes a shaft 13, a shaft drive unit 14, a gate valve 15, and a substrate entrance / exit 16, and pulls up a plurality of flat plate-shaped ceramic complexes 2 grown and grown from the seed crystal 23. The shaft 13 holds the seed crystal 23. Further, the shaft drive unit 14 raises and lowers the shaft 13 toward the crucible 5, and rotates the shaft 13 about the raising and lowering direction. The gate valve 15 separates the container 20 and the pull-up container 4. Further, the substrate entrance / exit 16 takes in and out the seed crystal 23.

The manufacturing apparatus 19 also has a control unit (not shown), which controls the rotation of the crucible drive unit 18 and the shaft drive unit 14.

Next, the die 22 will be described. The die 22 is made of molybdenum and has a large number of dividers 24 as shown in FIG. FIG. 18 shows a case where 30 partition plates 24 are formed and 15 dies 22 are formed as an example of dies. The partition plates 24 have the same flat plate shape and are arranged in parallel with each other so as to form a minute gap (slit) 25 to form one die 22. The slit 25 is provided over almost the entire width of the die 22. Further, since the plurality of dies 22 have the same shape and are arranged in parallel at predetermined intervals so that their longitudinal directions are parallel to each other, a plurality of slits 25 are provided. A slope 29 is formed on the upper portion of each partition plate 24, and an acute-angled opening 31 is formed by arranging the slopes 29 facing each other. Further, the slit 25 has a role of raising the melt 17 from the lower end of each die 22 to the opening 31 by a capillary phenomenon.

The raw material put into the crucible 5 melts (raw material melt) based on the temperature rise of the crucible 5 to become the melt 17. A part of the melt 17 penetrates into the slit 25 of the die 22, rises in the slit 25 based on the capillary phenomenon as described above, is exposed from the opening 31, and the raw material melt pool 30 is exposed at the opening 31. Is formed (see FIG. 21 (a)). In the EFG method, the ceramic complex 2 grows according to the shape of the melt surface formed by the raw material melt pool (hereinafter, referred to as “melt pool” if necessary) 30. In the die 22 shown in FIG. 18, since the shape of the melt surface is an elongated rectangle, a flat plate-shaped ceramic composite 2 is manufactured.

Next, the seed crystal 23 will be described. As shown in FIGS. 17, 20, and 21, in this embodiment, a flat plate-shaped ceramic composite substrate is used as the seed crystal 23. Further, the seed crystal 23 is arranged so that the plane direction of the seed crystal 23 and the longitudinal direction of the die 22 are orthogonal to each other at an angle of 90 °. Further, since the seed crystal 23 and the ceramic complex 2 are also orthogonal to each other at an angle of 90 °, FIG. 17 shows the side surface of the ceramic complex 2.

If the contact area of the lower part of the shaft 13 with the substrate holder (not shown) is large, the seed crystal 23 will be deformed due to stress due to the difference in the coefficient of thermal expansion and will be damaged in some cases. On the contrary, the fixation of the seed crystal 23 may be loosened due to the difference in the coefficient of thermal expansion. Therefore, it is preferable that the contact area between the seed crystal 23 and the substrate holder is small. Further, the seed crystal 23 needs to have a substrate shape that can be securely fixed to the substrate holder.

FIG. 19 is a diagram showing an example of the substrate shape of the seed crystal 23. Of these, in FIGS. (A) and (b), a notch 26 is provided in the upper part of the seed crystal 23. Using this notch 26, for example, a U-shaped substrate holder can be inserted from the lower side of two notches 26 to reliably hold the seed crystal 23 while reducing the contact area. Become.

Further, as shown in FIG. 19 (c), a notch hole 27 may be provided inside the seed crystal 23. Using this notch hole 27, for example, a locking claw is inserted into two notch holes 27 to securely hold the seed crystal 23 while reducing the contact area between the substrate holder and the seed crystal 23. It becomes possible.

Next, a method of manufacturing the ceramic complex 2 using the manufacturing apparatus 19 will be described. First, granulated raw material powder (as an example, powder containing 64.71% by weight of aluminum oxide, 35.02% by weight of yttrium oxide, 0.003% by weight of magnesium oxide, 0.27% by weight of cerium oxide), which is the raw material of the ceramic composite, is used. A predetermined amount is put into the crucible 5 in which the die 22 is stored and filled. The raw material powder may contain compounds and elements other than the above, depending on the purity or composition of the ceramic complex to be produced.

Subsequently, in order not to oxidatively consume the crucible 5, the heater 7, or the die 22, the inside of the container 20 is replaced with argon gas, and the oxygen concentration is set to a predetermined value or less.

Next, the crucible 5 is heated to a predetermined temperature by heating with the heater 7, and the raw material powder is melted. The heating temperature of the crucible 5 is above the melting point of the ceramic composite 2 and below the melting point of aluminum oxide, sapphire crystals, or ruby crystals. Since the melting point of the ceramic complex 2 is about 1820 ° C. to 1870 ° C., the heating temperature of the crucible 5 is set to be about 50 ° C. higher than the melting point of the ceramic complex 2 as an example. After a while after heating the crucible 5, the raw material powder melts and the raw material melt 17 is prepared. The temperature of the melt 17 is set above the melting point of the ceramic composite 2 and below the melting point of aluminum oxide, sapphire crystals, or ruby crystals. Further, a part of the melt 17 rises through the slit 25 of the die 22 due to the capillary phenomenon and reaches the surface of the die 22, and a melt pool 30 is formed on the upper portion of the slit 25.

Next, as shown in FIGS. 20 and 21, the seed crystal 23 is lowered while being held at an angle perpendicular to the longitudinal direction of the melt pool 30 above the slit 25, and the seed crystal 23 is melted in the melt pool 30. Contact the liquid surface. The seed crystal 23 is introduced into the pull-up container 4 from the substrate entrance / exit 16 in advance. In FIG. 20, in order to give priority to the visibility of the slit 25 and the opening 31, the melt 17 and the melt pool 30 are not shown.

FIG. 20 is a diagram showing the positional relationship between the seed crystal 23 and the partition plate 24. As described above, by making the plane direction of the seed crystal 23 orthogonal to the longitudinal direction of the partition plate 24, it is possible to reduce the contact area between the seed crystal 23 and the melt 17. Therefore, the contact portion of the seed crystal 23 becomes familiar with the melt 17, and crystal defects are less likely to occur in the ceramic complex 2 to be grown and grown.

When the seed crystal 23 is brought into contact with the melt surface, the lower part of the seed crystal 23 may be brought into contact with the upper part of the partition plate 24 to be melted. FIG. 21 (b) is a diagram showing a state in which a part of the seed crystal 23 is melted. By melting a part of the seed crystal 23 in this way, the temperature difference between the seed crystal 23 and the melt 17 can be quickly eliminated, and the occurrence of crystal defects in the ceramic composite 2 can be further reduced. It will be possible.

Subsequently, the substrate holder is pulled up at a predetermined ascending speed, and the seed crystal 23 is started to be pulled up. Specifically, the shaft 13 raises the substrate holder at a predetermined speed.

In addition, in order to facilitate the alignment of the seed crystal with respect to the opening 31 of the die 22, unevenness may be provided on the lower side of the seed crystal 23. FIG. 22 is a diagram illustrating the shape of the lower side of the seed crystal 23. FIG. 22A shows a case where the lower side has a comb tooth shape, and FIG. 22B shows a case where the lower side has a sawtooth shape.

The spacing between the irregularities is adjusted to the spacing of the openings 31, and the convex portion is aligned with the center of the melt pool 30. By providing the convex portion, the convex portion can be used as the growth start point of the ceramic complex 2, and the ceramic complex 2 can be formed more easily. The shape of the unevenness is not limited to that shown in FIG. 22, and may be, for example, a corrugated uneven shape.

The substrate holder is raised at a predetermined speed, and the ceramic complex 2 is crystal-grown around the seed crystal 23 so as to widen in the longitudinal direction of the die 22 as shown in FIG. 23 (spreading). When the ceramic complex 2 is widened to the full width of the die 22 (the end of the partition plate 24) (full spread), a flat plate-shaped ceramic complex 2 having a width similar to the full width of the die 22 is grown. (Straight body process). FIG. 23 is a schematic view showing how the width of the ceramic complex 2 is expanded by the spreading step. By obtaining the wide ceramic composite 2, the yield of the ceramic composite product is improved.

After growing the ceramic complex 2 to the full width of the die 22 by the spreading step, as shown in FIG. 24, the flat plate-shaped straight body portion 28 having a constant width similar to the full width of the die 22 is subjected to a predetermined speed. In, a pulling step of pulling up to a predetermined length (straight body length) is carried out to obtain a flat plate-shaped ceramic composite 2.

During the period of the pulling process, the temperature is controlled by using a heater 7 or the like so that the interface temperature of the melt 17 in the melt pool 30 formed in the upper part of the slit 25 becomes constant. The ceramic complex 2 grows when the melt 17 that has risen to the melt pool 30 is cooled while being pulled up in contact with the seed crystal 23. Therefore, by controlling the temperature of the melt pool 30 to be constant, the crystal growth conditions can be kept the same during the growth period of the ceramic complex 2, and a uniform lamellar structure can be formed over the entire ceramic complex 2. Can be done.

The pulling speed of the seed crystal 23 in the pulling step is preferably in the range of 0.9 mm / hour or more and 400 mm / hour or less. More preferably, it is in the range of 50 mm / hour or more and 200 mm / hour or less. By setting the pulling speed of the seed crystal 23 to 50 mm / hour or more, it is possible to prevent the introduction of cracks into the ceramic complex 2. Further, by setting the pulling speed to 200 mm / hour or less, the growing state of the ceramic complex 2 can be further stabilized.

When the pulling speed is less than 0.9 mm / hour, the size of the lamellar structure fluctuates greatly with respect to the error of the pulling speed, and it becomes difficult to control the size of the lamellar structure. Therefore, the emission intensity of the white light of the grown and grown ceramic complex 2 is lowered. In addition, the slow growth rate reduces productivity. When the pulling speed is larger than 400 mm / hour, it becomes difficult to control the temperature of the melt pool 30, and therefore it becomes difficult to control the size of the lamellar structure. Further, if the pulling speed is too high, the melt 17 of the melt pool 30 is likely to be separated from the seed crystal 23 and the straight body portion 28, and the growth is likely to be interrupted, which is not preferable.

After that, the obtained ceramic complex 2 is allowed to cool, the gate valve 15 is opened, the gate valve 15 is moved to the pulling container 4, and the ceramic composite 2 is taken out from the substrate entrance / exit 16. The appearance of the obtained flat plate-shaped ceramic complex 2 is shown in FIG. The length of the straight body is not particularly limited, but is preferably 2 inches or more (50.8 mm or more).

Further, as shown in FIG. 25, the total width of the die 22 and the width of the seed crystal 23 may be the same, and the ceramic complex 2 may be grown and grown with the same width as the total width of the seed crystal 23. In FIG. 25, the melt 17 and the melt pool 30 are not shown in order to give priority to the visibility of the slit 25.

By using the manufacturing apparatus 19, the seed crystal 23, and the die 22 as described above, it is possible to simultaneously manufacture a plurality of ceramic complexes 2 from the common seed crystal 23.

The die 22 including the seed crystal 23 and the partition plate 24 needs to be precisely positioned. Therefore, as shown in FIG. 17, the manufacturing apparatus 19 is provided with a crucible drive unit 18 for rotating the crucible 5 on which the die 22 is installed, and a control unit (not shown) for controlling the rotation thereof. Further, the shaft 13 is also provided with a shaft drive unit 14 that rotates the shaft 13 and a control unit (not shown) that controls the rotation thereof. That is, the positioning of the seed crystal 23 with respect to the die 22 is adjusted by rotating the shaft 13 or the crucible 5 by the control unit. Precise positioning of the seed crystal 23 and the die 22 can also be performed by using the die 22 in which a part of the slope 29 of each partition plate 24 is cut out.

As described above, the solidified ceramic composite 2 is prepared in advance. Further, in the embodiment of FIGS. 11 to 13, the prepared ceramic composite 2 of the solidified body is arranged on the step 6c. Next, only the ceramic composite 2 of the solidified body arranged in the step 6c is melted, and a melt composed of at least aluminum oxide and yttrium oxide is prepared and spread in the step 6c which is a gap between the crystals (6, 6). Go.

The melting method of only the ceramic complex 2 is performed by utilizing the difference between the melting point of the ceramic complex 2 and the melting point of the crystal 6. Specifically, the ceramic complex 2 and crystals (6, 6) in the state shown in FIG. 12 are heated in a heating furnace or the like. The heating temperature at that time may be higher than the melting point of the ceramic composite 2 and lower than the melting point of the aluminum oxide, sapphire crystal, or ruby crystal. As an example, the heating temperature is about 50 ° C. above the melting point of the ceramic complex 2.

Only the upper and lower crystal (6, 6) portions in contact with the melt spread in the step 6c are melted. As described above, the _{applicant has found that by collecting the Al 2} O ₃ phase of the crystal 6 on the contact surface with the melt, only the contact surface is preferentially melted even if the temperature is lower than the melting point of the crystal 6. And _Al 2 _{O 3} phase of each crystal (6,6) by its melting, _Al 2 _{O 3} phase of aluminum oxide melt is integrated in a state bonded interface is not another.

After that, by allowing the melt and the melted portion of each crystal (6, 6) to cool and cool, the solidified ceramic composite 2 is formed in the step 6c as shown in FIG. 13, and the upper and lower crystals (6) are formed. , and _Al 2 _{O 3} phase 6), _Al 2 _{O 3} phase of the ceramic composite body 2, are integrated in a state bonded interface is not another.

On the other hand, in the embodiment of FIGS. 14 to 16, the prepared ceramic composite 2 of the solidified body is placed on the surface of the lower substrate 6, and then only the ceramic complex 2 is melted in the heating furnace or the like to at least. Prepare a melt composed of aluminum oxide and yttrium oxide. The heating temperature of the ceramic composite 2 is above the melting point of the ceramic composite 2 and below the melting point of aluminum oxide, sapphire crystals, or ruby crystals. As an example, the heating temperature is about 50 ° C. above the melting point of the ceramic complex 2.

The melt spreads on the main surface of each of the middle and lower crystals 6, comes into contact with each main surface, and is also infiltrated into each through hole 6a by a capillary phenomenon, and the crystal portion in each through hole 6a. Is in contact with the melt. Further, the melt passes through each through hole 6a, spreads on the other main surface of the crystal 6 in the middle and on the main surface of the crystal 6 on the upper side, and comes into contact with each main surface.

Only the main surface and the crystal 6 parts of the through hole 6a of each of the three crystal 6 in contact with the melt, is melted by the melt, and Al ₂ O ₃ phase of each crystal 6, Al ₂ O aluminum oxide melt _{The three} phases are integrated without a bonding interface with each other.

After that, by allowing the melt and the melted portion of each crystal 6 to cool and cool, the upper and lower crystals (6, 6) sandwich the middle crystal 6 and further cover the middle crystal 6 as shown in FIG. The solidified ceramic composite 2 is formed as described above. Accordingly, the Al ₂ O ₃ phase of the crystal 6 parts in three main surface and the through hole 6a of each crystal 6, Al ₂ O ₃ phase of the ceramic composite body 2, are integrated in a state bonded interface is not mutually .. Further, the ceramic complex 2 is sandwiched between the upper and lower crystals (6, 6).

The gap between the upper and lower crystals (6, 6) in FIG. 16 is the thickness (1 mm) of the middle crystal 6.

The shape of each crystal 6 in FIGS. 11 to 16 in the plane direction may be a square shape. Further, the arrangement position of the ceramic complex 2 shown in FIGS. 14 and 15 may be changed between the upper crystal 6 main surface and the middle crystal 6 main surface. Further, each through hole 6a may be a stop hole.

Examples 1 and 2 of the present invention will be described below, but the present invention is not limited to the following examples. In Examples 1 and 2, a sapphire single crystal was used as the crystal. The sapphire single crystal had a rectangular outer shape, had external dimensions of 44.5 mm × 100 mm, a diagonal length of 109 mm, and a thickness of 1 mm. Further, only in Example 2, a slit composed of a step (6c in FIGS. 3 and 4) was formed on the joint surface with W = 30 mm and a thickness of 0.01 mm.

As the raw material of the ceramic composite, a raw material powder containing 64.71% by weight of aluminum oxide, 35.02% by weight of yttrium oxide, 0.003% by weight of magnesium oxide, and 0.27% by weight of cerium oxide is melted in the crucible to prepare a melt. did. Further, Ce was contained in 0.3 mol% in Example 1 and 0.1 mol% in Example 2.

The crucible used was made by Mo. Therefore, Mo was contained in the melt in an amount of 1.0 mol · ppm or more and 30,000 mol · ppm or less.

After filling the crucible with the raw material powder, the crucible was heated to form a melt. After the formation of the melt, the directly bonded sapphire single crystal was immersed in the melt up to 30 mm in Example 1 and up to 50 mm in Example 2 out of the external dimensions of 100 mm. The longitudinal direction of the gap between the sapphire single crystals is orthogonal to the surface direction of the liquid surface of the melt, the sapphire single crystal is immersed in the melt, and the melt is poured into the gap or slit of the joint surface by capillarity. Infiltrated.

Sapphire single crystal portion in contact with the melt by the infiltration is melted, and Al ₂ O ₃ phase of the sapphire single crystal, Al ₂ O ₃ phase of aluminum oxide ceramic composite 2 material are integrated by melting. After that, it was cooled and polished to form a ceramic complex composed of a solidified body. Both ceramic composite body of each example, the Al ₂ O ₃ phase of the duplex, Al ₂ O ₃ phase of the sapphire single crystal, it was confirmed that it is integrated in a state bonded interface is not another. Moreover, the obtained ceramic complex was yellow.

It was also confirmed that the gap between the crystals was formed as thin as 0.01 mm in both examples. In Example 2, it was confirmed that the melt was infiltrated only within the range of the slit width W = 30 mm to form the ceramic composite.

When the ceramic complex was irradiated with blue light from the outside of the sapphire single crystal, it was confirmed that it was converted to white light in both examples.

1, 19 Ceramic composite manufacturing equipment 2 Ceramic composite 3, 20 container 4 Lifting container 5 Crucible 6 Crystal 6a Hole 6b Gap between crystals 6c Step 7 Heater 8 Electrode 9 Pipe-shaped crystal 9a Hole 10 Insulation material 11 Atmospheric gas inlet 12 Atmospheric gas exhaust port 13 Shaft 14 Shaft drive 15 Gate valve 16 Ceramic composite inlet / outlet 17 Melt 18 Crucible drive 22 Die 23 Species crystal 24 Partition plate 25 Slit 26 Notch 27 Notch Hole 28 Straight body 29 Slope 30 Crucible pool 31 Opening W Width of step 6c

Claims (11)

1. At least _Y 3 _Al 5 _O two oxide phases ₁₂ phase and _Al 2 _{O 3} phase and having a lamellar structure, the _Al 2 _{O 3} phase and, _Al 2 _{O 3} of any of the crystals of sapphire crystal or ruby crystals A ceramic composite in which the phases are integrated without a bonding interface.
2. Wherein with crystal are provided at least two, are sandwiched by the two said crystal, said Al ₂ O ₃ phase of the crystal, said ceramic composite body the Al ₂ O ₃ phase is mutually bonding interface The ceramic composite according to claim 1, which is integrated without any shavings.
3. The ceramic composite according to claim 2, wherein the gap between the crystals in which the ceramic composite is sandwiched is 0.01 mm or more and 1 mm or less.
4. A stop hole or a through hole is formed in the crystal, and the ceramic composite is inserted into the stop hole or the through hole to form the Al ₂ O ₃ phase of the crystal and the ceramic composite. The ceramic composite according to claim 1, wherein the Al ₂ O ₃ phases are integrated without a bonding interface with each other.
5. The ceramic composite according to claim 4, wherein the diameter of the stop hole or the through hole is 0.1 mm or more and 3 mm or less.
6. At least the process of preparing a melt consisting of aluminum oxide and yttrium oxide,
   One crystal of sapphire crystal or ruby crystal in contact with the melt, to melt the said crystalline portion in contact with the melt, and Al ₂ O ₃ phase of the crystal, Al ₂ O ₃ of the aluminum oxide The process of integrating the phases without a bonding interface by melting,
   A method for producing a ceramic complex, which comprises a step of cooling the melt.
7. A step of preparing at least two of the crystals and stacking them on top of each other.
   A step of putting a raw material containing at least the aluminum oxide and the yttrium oxide into the crucible, and
   A step of heating the crucible and melting the raw material in the crucible to prepare the melt.
   The crystals are brought into contact with the melt, the melt is infiltrated into the gaps between the stacked crystals by a capillary phenomenon, the melt is sandwiched between the crystals, and the crystals are brought into contact with the melt. the crystalline portion in contact with the melt to melt, and the Al ₂ O ₃ phase of the crystal, a step of the mutually bonding interface by melting the Al ₂ O ₃ phase of the aluminum oxide are integrated without
   The method for producing a ceramic complex according to claim 6, further comprising a step of removing the crystals from the melt and cooling the melt integrated with the crystals.
8. The method for producing a ceramic complex according to claim 7, wherein the gap between the crystals is 0.01 mm or more and 1 mm or less.
9. The method for producing a ceramic complex according to claim 7 or 8, wherein the longitudinal direction of the gap between the crystals is orthogonal to the surface direction of the liquid surface of the melt.
10. The step of forming a stop hole or a through hole in the crystal and
    The melt is infiltrated into the stop hole or the through hole by a capillary phenomenon to melt the crystal portion in the stop hole or the through hole in contact with the melt, and the Al ₂ O of the crystal. _The method for producing a ceramic composite according to claim 6, further comprising a step of integrating the _{three phases and the Al 2} O 3 phase of the aluminum oxide with each other without a bonding interface by melting.
11. The method for producing a ceramic composite according to claim 10, wherein the diameter of the stop hole or the through hole is 0.1 mm or more and 3 mm or less.

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