JP2017067993A - Manufacturing method of substrate, substrate obtained thereby, and manufacturing method of light emitting device - Google Patents

Abstract

A method of manufacturing a substrate capable of easily obtaining a substrate having a light conversion function and capable of producing an LED by simultaneously completing the bonding of the light conversion layer portion of the inorganic material and obtaining the same. And a method for manufacturing the light emitting device.
A method of manufacturing a substrate in which a crystal substrate and a ceramic composite having a structure in which two or more kinds of crystal phases are entangled with each other are laminated, wherein the raw material of the ceramic composite is used above the melting point of the crystal substrate. A raw material adjusting step for adjusting the raw material to be lowered, a raw material laminating step for laminating the crystal substrate and the raw material, and a heating step for heating the raw material so that the raw material is melted and integrated with the crystal substrate; And a cooling step of cooling the melted raw material to obtain a crystallized ceramic composite.
[Selection] Figure 2

Description

  The present invention relates to a method for manufacturing a substrate for a light emitting diode that can be used for a display, illumination, a backlight light source, and the like, a substrate obtained thereby, and a method for manufacturing a light emitting device. Specifically, the present invention relates to a method for manufacturing a substrate for a light emitting diode having a light conversion function and a light scattering function, a substrate obtained thereby, and a method for manufacturing a light emitting device.

  In recent years, white light-emitting diodes (LEDs) that use light-emitting diodes using nitride-based compound semiconductors as light sources have been widely used. White LEDs are excellent light sources from the viewpoint of energy and environment because of high efficiency, long life, light weight, and mercury-free. Furthermore, in recent years, the use of these light sources for lighting of automobile headlights, outdoor stadiums, gymnasiums and the like has been studied. Since these illuminations are required to have higher luminance and higher light intensity than conventional ones, the energy input to the LEDs increases. However, as a result, the heat generation of the LED increases, making it difficult to use resin materials that have been used in the manufacture of conventional LEDs.

  A portion that is particularly affected by heat in a conventional white LED is a portion of a light conversion layer in which a resin and a phosphor powder are mixed. This portion exists directly above the LED element, and is affected by heat generated by the LED element and the light conversion of the phosphor, so that the resin material cannot withstand a high-brightness, high-intensity LED.

  In order to solve this problem, inorganicization of the light conversion layer is effective. As a method for mineralizing the light conversion layer, a light conversion layer in which a phosphor is dispersed in glass (Patent Document 1), a light conversion layer using a ceramic composite (Patent Document 2), and a method using a sintered light conversion layer (Patent Document 3) and the like have been proposed.

Furthermore, it is difficult to use a resin used when the light conversion layer is connected to the LED. As one of the solutions, a method using a substrate obtained by directly bonding an inorganic light conversion layer to a single crystal substrate capable of producing an LED is disclosed. This method can be said to be an excellent method because the heat generation path of the element can be used to release heat generated in the light conversion layer. When an LED is produced using this substrate, it is possible to produce a completely inorganic white LED.
As a method of manufacturing a substrate in which an inorganic light conversion layer is directly bonded to a single crystal substrate capable of producing an LED, for example, a method of bonding by hot pressing (Patent Document 4), a method of activating a surface and bonding (Patent Document) 5) and the like are known, and in each case, a ceramic composite is once produced, and then a method of bonding to a single crystal substrate capable of producing an LED is employed.

JP 2003-258308 A Japanese Patent No. 4609319 JP 2006-5367 A Japanese Patent No. 5029362 JP 2011-216543 A

  However, the methods described in Patent Documents 4 and 5 have a problem that the manufacturing process becomes long and the cost becomes high.

  The present invention has been made in view of the above-described problems, and it is possible to manufacture an LED, not a method of bonding an optical conversion layer to a single crystal substrate on which an LED can be manufactured after manufacturing a light conversion layer of an inorganic material. A method for producing a light conversion layer on a single crystal substrate, that is, a substrate capable of producing an LED with a light conversion function by completing the bonding at the same time as producing the light conversion layer portion of an inorganic material. It is an object of the present invention to provide a method for manufacturing a substrate that can be easily obtained, a substrate obtained thereby, and a method for manufacturing a light emitting device.

  As a result of intensive investigations to achieve the above object, the inventors of the present invention have formed a ceramic composite melt on a single crystal substrate and crystallized the ceramic composite and single crystal substrate. Knowing that it is possible to produce a substrate directly bonded, we found that a ceramic composite layer and a single crystal substrate capable of producing an LED can be produced simultaneously with the production of the ceramic composite layer, The present invention has been reached.

  That is, the present invention is a method for producing a substrate in which a crystal substrate and a ceramic composite having a structure in which two or more kinds of crystal phases are entangled with each other, wherein the raw material of the ceramic composite is used as the raw material of the crystal substrate. A raw material adjusting step for adjusting the raw material to be lower than a melting point; a raw material stacking step for stacking the crystal substrate and the raw material; and heating the raw material so that the raw material is melted and integrated with the crystal substrate. The present invention relates to a substrate manufacturing method comprising: a heating step; and a cooling step of cooling the melted raw material to obtain a crystallized ceramic composite.

  The present invention also relates to a method of manufacturing a substrate in which a crystal substrate and a ceramic composite having a structure in which two or more kinds of crystal phases are entangled with each other, wherein the crystal substrate and the raw material ceramic composite are stacked. A raw material stacking step, a heating step of heating the raw material ceramic composite so that the raw material ceramic composite is melted and integrated with the crystal substrate, and cooling and crystallization of the molten raw material ceramic composite And a cooling step for obtaining a ceramic composite.

  The present invention also relates to a substrate obtained by the method for manufacturing a substrate.

In the present invention, the substrate obtained by the substrate manufacturing method and Ln ₃ Al ₅ O ₁₂ (Ln is at least one element of Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu). ) A method of manufacturing a light emitting device comprising a light emitting element capable of irradiating light excited by a phosphor forming a first crystal phase comprising a phase, comprising the ceramic composite that has been cooled and crystallized. The present invention relates to a method for manufacturing a light emitting device, comprising an element mounting step of mounting the light emitting element on a substrate.

  As described above, according to the present invention, it is possible to easily obtain a substrate having a light conversion function and capable of manufacturing an LED by completing the bonding at the same time as the light conversion layer portion of the inorganic material. A method for manufacturing a substrate, a substrate obtained thereby, and a method for manufacturing a light emitting device can be provided.

  Since the light conversion layer produced on the substrate by the method of the present invention is completely in close contact with the single crystal substrate on which the LED can be produced, heat is easily diffused from the light conversion layer to the single crystal substrate. It is suitable for LEDs that generate heat. Furthermore, when the ceramic composite is formed, since the bonding with the single crystal substrate capable of producing the LED is completed, the process is simplified. Further, when an LED is manufactured using this substrate, for example, it becomes a white LED as it is, which helps to reduce the manufacturing cost.

It is a figure which shows the example of the eutectic phase equilibrium diagram. It is the schematic of the vacuum chamber of the single crystal growth furnace in which the crucible was installed. It is the schematic of the board | substrate produced by the manufacturing method of this invention. It is a figure which shows the result of having performed the pole measurement of the sample center in Example 1. FIG.

<Substrate manufacturing method>
First, the substrate manufacturing method of the present invention will be described.
In the substrate manufacturing method of the present invention, a ceramic composite having a structure in which two or more crystal phases are continuously and three-dimensionally entangled with each other is laminated on a crystal substrate on which a light emitting diode (LED) can be manufactured. This is a method for manufacturing a substrate.

(First embodiment)
Specifically, the manufacturing method according to the first embodiment of the present invention includes a raw material adjustment step of adjusting the raw material of the ceramic composite so as to be lower than the melting point of the crystal substrate, and the crystal substrate and the raw material. A raw material stacking step for laminating, a heating step for heating the raw material so that the raw material is melted and integrated with the crystal substrate, and a cooling step for cooling the melted raw material to obtain a crystallized ceramic composite Is provided.

(Raw material adjustment process)
The raw material of the ceramic composite can be prepared by the following method. First, raw material powders are mixed at a ratio such that a ceramic composite having a desired composition ratio is generated to obtain a raw material mixed powder. At this time, the composition of the raw material mixed powder is adjusted so that the ceramic composite is lower than the melting point of the crystal substrate. If the melting point of the ceramic composite is higher than the melting point of the crystal substrate, the crystal substrate will melt first in the heating step described later, which is not preferable.

Examples of the raw material powder for the ceramic composite used in the present invention include metal oxide powders such as Al ₂ O ₃ and SiO ₂ , Y ₂ O ₃ , Tb ₂ O ₃ , Dy ₂ O ₃ , and Ho ₂ O _3. , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ , Lu ₂ O ₃ and other rare earth metal element oxide powders are preferable. The metal oxide powder is more preferably Al ₂ O ₃ , and the rare earth metal element oxide powder is more preferably Y ₂ O ₃ , Tb ₂ O ₃ , Lu ₂ O ₃ , and particularly preferably Y ₂ O ₃ . Furthermore, additives such as CeO ₂ and Gd ₂ O ₃ can also be used as the raw material powder of the ceramic composite used in the present invention.

  In the present invention, the raw material powder of the ceramic composite may be adjusted in composition so that the crystal phase constituting the resulting ceramic composite includes a crystal phase belonging to a composition system that forms at least one eutectic. preferable. By adjusting the composition of the raw material powder in this manner, the raw material can be melted and integrated with the crystal substrate in the heating step described later.

  There is no special restriction | limiting about the mixing method of raw material powder, Both a dry-type mixing method and a wet-mixing method are employable. As a medium when using the wet mixing method, alcohol such as methanol or ethanol is generally used. When the wet mixing method is adopted, the used medium is removed by a rotary evaporator or the like.

  In addition, the raw material of the ceramic composite can be molded into a sheet instead of powder and fired. As a method for forming the raw material into a sheet, a general method such as mixing a binder and raw material powder and thinly extending the paste-like raw material to produce a sheet can be employed. The sheet containing the raw material and the binder is then fired in an electric furnace, and an unnecessary binder is removed to obtain a raw material sheet for the ceramic composite.

  In the present invention, the crystal phase constituting the ceramic composite includes a crystal phase belonging to a composition system that forms at least one eutectic, and the crystal phase constituting the crystal substrate is a composition system that forms the eutectic. It is preferably a crystal phase having the same composition and crystal structure as any one of the crystal phases to which it belongs. The eutectic is a phenomenon in which a plurality of crystals are simultaneously crystallized when a melt having a uniform molten state at a high temperature falls below the melting point. A composition system (eutectic system) that forms a eutectic is a system that uses the crystal phase that is simultaneously crystallized as an end component. These relationships will be described with reference to FIG. 1 showing an example of a eutectic phase equilibrium diagram. In this case, the crystal phase constituting the crystal substrate is more preferably a single crystal.

  In FIG. 1, for example, a case where a single crystal substrate on which a ceramic composite material having a eutectic composition of components A and B is placed is heated to produce a substrate will be described. The composition of the ceramic composite is the eutectic composition of end components A and B in FIG. 1, and the single crystal substrate used is a single crystal of end component A or B in FIG. As apparent from FIG. 1, the end component forming the eutectic system has a melting point higher than the eutectic temperature. By this relationship, when the single crystal substrate on which the ceramic composite material is placed is heated, it becomes easy to melt the ceramic composite and create a state in which the single crystal substrate is not melted.

  Specifically, when this starting material is heated, the ceramic composite material melts at the eutectic temperature to form a melt. At this time, since the single crystal substrate material has a melting point higher than the eutectic temperature, it hardly melts. However, when the ceramic composite melts, the eutectic composition having a low melting point locally occurs at the interface between the melt and the single crystal substrate, and the single crystal substrate melts slightly.

  This slight melting is most important in the present invention. In the substrate of the present invention, the interface between the ceramic composite and the single crystal substrate is not simply in contact, but both the single crystal substrate and the ceramic composite are melted and solidified. Can be achieved. Such an interface is advantageous in securing a heat conduction path. Such bonding cannot be realized simply by once producing a ceramic composite and bonding it to a single crystal substrate by hot pressing or the like.

  Furthermore, it is also advantageous that a reaction that generates an unnecessary third component does not occur in the reaction with the single crystal substrate when the ceramic composite is melted. When a ceramic composite is melted on a single crystal substrate that is not compositionally related, there is a possibility that a crystal phase harmful to the LED is generated by a chemical reaction. Therefore, it is possible to obtain a bonded substrate without generating a crystal phase other than the ceramic composite at the interface.

  In addition, since the single crystal substrate and the ceramic composite have a common crystal phase and are crystallized from the melted state, they can be solidified while maintaining an epitaxial relationship. For this reason, the ceramic composite can be crystallized in a single crystal state.

  As described above, the composition of the crystal phase constituting the ceramic composite of the present invention is preferably a eutectic composition. The reason is that the melting temperature of the crystal substrate and the melting point of the ceramic composite are farthest from each other, so that the production temperature can be set most easily. However, the composition of the crystal phase constituting the ceramic composite does not necessarily need to match the eutectic composition. Even if the composition of the crystal phase composing the ceramic composite deviates from the eutectic composition, if the melt can be formed in the heating process, the ceramic composite and the crystal substrate can be bonded at the atomic level, and locally co-located. The crystal composition is reached and local melting is possible. When deviating from the eutectic composition, the crystal of the end component of the system crystallizes as the primary crystal, but even in such a state, the interface can reach the eutectic composition locally. It is possible to melt the substrate.

  In the present invention, the crystal phase constituting the crystal substrate is preferably a crystal phase having the same crystal structure as the crystal phase having the highest melting point among the crystal phases constituting the ceramic composite. In this way, temperature conditions can be set most easily when the substrate is manufactured. Moreover, it is because the range of the composition to select becomes wide.

(Raw material lamination process, heating process and cooling process)
Next, the prepared ceramic composite raw material mixed powder or raw material sheet is laid on a crystal substrate, placed in a crucible, placed in an electric furnace, heated and fired to form a ceramic composite melt. Thereafter, the ceramic composite is crystallized on the crystal substrate by cooling.

  The electric furnace can be used without any limitation as long as it can be heated to a temperature higher than the melting point of the ceramic composite and can control the atmosphere. In particular, a single crystal growth furnace such as a Bridgeman apparatus capable of producing a single crystal can be preferably used.

FIG. 2 shows an example of a state in which a crucible is installed in a vacuum chamber of a single crystal growth furnace.
In the single crystal growth furnace used in the present invention, the heater 3 is installed in the chamber 1, and the atmosphere can be controlled. A shaft 7 for moving the crucible 5 up and down is installed inside the heater 3. The crucible 5 is installed on the upper side of the shaft 7, and the raw material mixed powder 9 of the ceramic composite and the crystal substrate 11 are heated and melted therein. The temperature is lowered by pulling out the crucible 5 from the inside of the heater 3, and the ceramic composite material that has been melted is crystallized. When crystallizing while pulling out the crucible 5, unidirectional solidification occurs.

  More specifically, the crucible 5 is loaded with the crystal substrate 11 on which the ceramic composite raw material mixed powder 9 is placed, and then the heater 1 is energized with the inside of the chamber 1 of the single crystal growth furnace set in a desired atmosphere. Start heating up. While confirming that the temperature measured by a thermocouple (not shown) installed outside the crucible 5 directly below the crystal substrate 11 does not exceed the melting point of the crystal phase constituting the crystal substrate 11, the temperature is adjusted and the ceramic composite The raw material mixed powder 9 is melted. The crystal of the ceramic composite can be grown by a method of holding the state for a certain time after melting and then pulling down the crucible 5 or a method of lowering the heating temperature while keeping the position of the crucible 5 constant.

The temperature at which the ceramic composite raw material mixed powder 9 is melted is appropriately set depending on the type of the ceramic composite raw material mixed powder 9. For example, the ceramic composite raw material powder is mixed with Al ₂ O ₃ powder. In the case of a mixture of Y ₂ O ₃ powder and CeO ₂ powder, it may be higher than the eutectic temperature of this system, and is about 1820 to 2000 ° C. Producing near the eutectic temperature can reduce the amount of melting of the substrate, which is suitable for production. In consideration of this point, 1820 to 1900 ° C. is preferable.

  The atmosphere in which the melt is solidified can be any of a pressurized atmosphere, an atmospheric pressure, and a reduced pressure atmosphere. However, in order to suppress the oxidation consumption of the crucible 5 and the constituent members of the single crystal growth furnace, it is preferable to circulate high-purity Ar gas. It is possible even under normal pressure.

  When the crucible 5 is pulled down, the speed is appropriately set depending on the melt composition and melting conditions, but is usually 50 mm / hour or less, preferably 1 to 20 mm / hour. If the heating temperature is lowered, the temperature can be lowered as long as the crystal substrate 11 is not broken.

  Further, the shape of the crucible 5 is not particularly limited as long as the crystal substrate 11 can be installed. For example, a circular or square crucible can be used. The crucible 5 may be made of any material that has heat resistance that does not melt at a temperature equal to or higher than the melting point of the ceramic composite and that does not react with the melt. In particular, molybdenum and alumina are generally used.

  The above example is a manufacturing example in a furnace capable of growing a single crystal, but the substrate of the present invention can also be manufactured in a general electric furnace. In this case, heat escape from the substrate to be manufactured is less likely to be unidirectional, but local unidirectional solidification occurs, and even in this case, a structure in which two or more crystal phases are complicatedly entangled can be obtained. .

  When the melt of the ceramic composite is solidified, the power of the heater is lowered and the furnace is cooled. After cooling, the furnace is opened, the crucible is taken out, and the crystal substrate to which the ceramic composite layer is bonded is taken out. The substrate may be cut and used as an LED manufacturing substrate. In some cases, the substrate may be used as a simple light conversion member instead of an LED manufacturing substrate.

  The thickness of the ceramic composite on the crystal substrate to which the ceramic composite layer is bonded is determined according to the required requirements. The thickness can be controlled by adjusting the amount of the starting material, but it can also be controlled by grinding after production.

(Second Embodiment)
In addition, the manufacturing method according to the second embodiment of the present invention includes a raw material lamination step of laminating a crystal substrate and a raw material ceramic composite, and so that the raw material ceramic composite is melted and integrated with the crystal substrate. A heating step of heating the raw material ceramic composite; and a cooling step of cooling the melted raw material ceramic composite to obtain a crystallized ceramic composite.

(Raw material lamination process)
In the present invention, as a raw material to be laminated on a crystal substrate, not only a raw material mixed powder (first embodiment) that forms a ceramic composite by melting by heating and cooling, but also the ceramic composite itself, specifically, It is also possible to use a solid ceramic composite, a crushed ceramic composite, and a finer powder.

  In the present embodiment, the raw ceramic composite preferably includes a crystal phase belonging to a composition system that forms at least one eutectic. By using such a raw material ceramic composite, the crystal phase constituting the ceramic composite formed through the heating process and the cooling process described later includes a crystal phase belonging to a composition system that forms at least one eutectic. This is preferable.

(Heating process and cooling process)

  Further, in the heating process of the present embodiment, it is considered that when a material obtained by pulverizing a ceramic composite as a raw material ceramic composite and a material made finer and powdered are melted, the raw material ceramic composite Is a mass of a ceramic composite, only the interface may be melted.

<Board>
An outline of the substrate produced by the production method of the present invention as described above is shown in FIG. 11 is a crystal substrate, and 12 is a crystallized ceramic composite.

(Crystal substrate)
The crystal substrate is preferably a single crystal substrate capable of producing an LED, and has a crystal phase having the same crystal structure as any one of crystal phases constituting a ceramic composite belonging to a composition system that forms a eutectic. Particularly preferred. As a crystal capable of forming a eutectic system, Al ₂ O ₃ (sapphire) is suitable.

(Ceramic composite)
The ceramic composite itself used in the present invention is specifically disclosed in, for example, Japanese Patent No. 3216683, Japanese Patent No. 3412381, Japanese Patent No. 4609319, Japanese Patent Laid-Open No. 2000-272955, etc. A known ceramic composite having a structure in which two or more crystal phases are continuously and three-dimensionally entangled with each other is preferably used. This ceramic composite is a ceramic composite that can be suitably used as a high-temperature structural material, a light conversion member, and other functional materials having good mechanical properties at high temperatures.

  The structure in which two or more kinds of oxide phases of this ceramic composite are entangled in a complicated three-dimensional manner is excellent in terms of light mixing. Further, when the ceramic composite has a fluorescence and light transmission function, the excitation light of the LED and the fluorescence emitted from the ceramic composite can be efficiently mixed to obtain another color, for example, white.

  The ceramic composite according to the present invention is a ceramic composite for light conversion in which the first crystal phase is a crystalline phase that emits fluorescence, and a part of the received light is converted into light having a wavelength different from that of the received light. Is preferable because it is suitably used as a substrate having a light conversion layer.

In particular, the ceramic composite according to the present invention is a first crystal composed of an Ln ₃ Al ₅ O ₁₂ (Ln is at least one element of Y, Tb, Dy, Ho, Er, Tm, Yb and Lu) phase. In the case of a ceramic composite composed of a phase and a second crystal phase made of Al ₂ O ₃ , a substrate with light scattering and light mixing properties excellent in mechanical properties at high temperatures can be produced. preferable.

  Further, when Ln is at least one element of Y, Tb, and Lu, and the first crystal phase is a ceramic composite for light conversion that is a crystal phase containing Ce as an activator, the first crystal A crystal substrate capable of producing an LED because blue light received by the phase is converted into yellow light, and the second crystal phase transmits blue light as it is and can emit white light in which yellow light and blue light are mixed. And is particularly suitable as a substrate material for white light emitting diodes.

In addition, when Ln is Y, that is, the ceramic composite according to the present invention includes a first crystal phase composed of a Y ₃ Al ₅ O ₁₂ phase activated by Ce, which is a crystal phase emitting fluorescence, and Al _In the case of a ceramic composite for light conversion having a structure in which the second crystal phase composed of ₂ O ₃ is continuously and three-dimensionally entangled with each other, the internal quantum efficiency is particularly high, so that an LED can be manufactured. It is particularly suitable and preferred as a substrate material for white light emitting diodes by combining with a crystal substrate. Further, the first crystal phase composed of the Y ₃ Al ₅ O ₁₂ phase activated by Ce can contain Gd. When the first crystal phase contains Gd, the wavelength of the fluorescence emitted from the first crystal phase can be increased.

A substrate manufactured by the manufacturing method of the present invention is formed of a crystal phase composed of Al ₂ O ₃ on a crystal substrate on which a light emitting diode can be manufactured, and Ln ₃ Al ₅ O ₁₂ (Ln is Y, Tb, Dy). , Ho, Er, Tm, Yb, and Lu.) A first crystal phase composed of a phase and a second crystal phase composed of Al ₂ O ₃ are continuously and three-dimensionally mutually. In the case of a substrate in which a ceramic composite having an intertwined structure is laminated, the interface between the crystal substrate and the ceramic composite is Ln ₃ Al ₅ O ₁₂ (Ln is Y, Tb, Dy, Ho, Er, Tm, It is at least one element of Yb and Lu). This is peculiar to the substrate produced by the production method of the present invention, and cannot be realized simply by once producing a ceramic composite and bonding it to a crystal substrate.

<Method for manufacturing light emitting device>
The light emitting device manufacturing method of the present invention comprises a light emitting device comprising a substrate obtained by the substrate manufacturing method and a light emitting element capable of irradiating light that excites a phosphor forming the first crystal phase. A manufacturing method, comprising: an element mounting step of mounting the light emitting element on a substrate including the ceramic composite that has been cooled and crystallized.

  Examples of the light emitting element capable of irradiating light excited by the phosphor forming the first crystal phase include an LED element made of a GaN-based semiconductor.

  According to the present invention, it is possible to manufacture a light emitting device (including a substrate to which a light conversion layer is directly bonded). Since the light conversion layer is directly bonded to the substrate, the work process can be shortened, and heat generated from a light emitting element such as an LED can be suitably dissipated from the substrate through the light conversion layer.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, these do not limit the objective of this invention.

Example 1
The α-Al ₂ O ₃ powder (purity 99.99%) and Y ₂ O ₃ powder (purity 99.999%) were mixed at a molar ratio of 82:18, and CeO ₂ powder (purity 99.99%) was added. to _Y 3 _Al 5 _{O 12} 1 mol of product by the reaction of charge oxide were weighed so as to be 0.01 mol. These powders were wet-mixed in ethanol by a ball mill for 16 hours, and then ethanol was removed using an evaporator to obtain a raw material mixed powder.

  Next, an a-axis [11-20] sapphire substrate was placed on the molybdenum crucible, and a green compact of the ceramic composite material mixed powder was placed thereon. Thereafter, similarly to the one shown in FIG. 2, a molybdenum crucible in which a sapphire substrate and raw material mixed powder are installed is set on the crucible shaft of the Bridgeman single crystal growth furnace, and Ar gas is supplied at a pressure of 2 L / min. Was adjusted to a vacuum of 6000 Pa and a heater output was applied. After the heater output and the furnace temperature were stabilized, the crucible shaft was slowly raised. After confirming the melting of the raw material from the observation window at the top of the furnace, the rising of the crucible shaft was stopped and held as it was for 10 minutes. Thereafter, the crucible was lowered at a speed of 5 mm / h to solidify the ceramic composite.

  After cooling, the furnace was opened and the sample was taken out. As for the appearance of the sample, the ceramic composite adhered in layers on sapphire.

When an SEM photograph of the cross section of this substrate was confirmed, it was found that a ceramic composite composed of Al ₂ O ₃ / YAG: Ce was adhered to the upper part of the sapphire substrate. Furthermore, it was confirmed that the crystal phase of the ceramic composite in contact with the sapphire substrate was all YAG phase, and a YAG phase layer was formed at the interface between the sapphire substrate and the ceramic composite.

In order to confirm the crystal orientation of the Al ₂ O ₃ phase and the YAG phase of this ceramic composite, pole measurement at the center of the sample was performed. In the pole measurement, the (300) plane and the YAG (400) plane of Al ₂ O ₃ were measured. As a result, as shown in FIG. 4, only one type of Al ₂ O ₃ (300) plane in the ceramic composite was confirmed, and a plurality of types of YAG (400) plane were confirmed. For the Al ₂ O ₃ phase, a stereo projection was created from the pole figure of Al ₂ O ₃ (300), and the a-axis [11-20] of Al ₂ O ₃ was confirmed. The a-axis [11-20] of Al ₂ O ₃ faces the vertical direction of the sample surface, and from this result, it is considered that the crystal orientation of the sapphire substrate was inherited by melting and solidification of the raw material in the sapphire substrate shape. It is done.
In Example 1, a configuration in which a YAG phase layer is present at the interface between the sapphire substrate and the ceramic composite is shown. However, according to the manufacturing method of the present invention, the ceramic composite is not limited to this structure. It is also possible to obtain a structure in which two or more crystal layers constituting the body are in contact with the substrate.

DESCRIPTION OF SYMBOLS 1 Chamber 3 Heating heater 5 Crucible 7 Axis 9 Raw material mixed powder of ceramic composite 11 Crystal substrate 12 Ceramic composite

Claims (11)

A method of manufacturing a substrate in which a crystal substrate and a ceramic composite having a structure in which two or more kinds of crystal phases are entangled with each other are laminated,
A raw material adjustment step of adjusting the raw material of the ceramic composite so as to be lower than the melting point of the crystal substrate;
A raw material stacking step of stacking the crystal substrate and the raw material;
A heating step of heating the raw material so that the raw material melts and becomes integral with the crystal substrate;
A cooling step of cooling the melted raw material to obtain a crystallized ceramic composite;
A method for manufacturing a substrate, comprising: A method of manufacturing a substrate in which a crystal substrate and a ceramic composite having a structure in which two or more kinds of crystal phases are entangled with each other are laminated,
A raw material lamination step of laminating the crystal substrate and the raw material ceramic composite;
A heating step of heating the raw material ceramic composite so that the raw material ceramic composite is melted and integrated with the crystal substrate;
Cooling the melted raw material ceramic composite to obtain a crystallized ceramic composite;
A method for manufacturing a substrate, comprising: The ceramic composite includes a crystal phase belonging to a composition system forming a eutectic,
3. The substrate manufacturing method according to claim 1, wherein any one of the crystal phases constituting the ceramic composite has the same composition and crystal structure as the crystal phase constituting the crystal substrate.   4. The method for manufacturing a substrate according to claim 1, wherein a crystal phase constituting the crystal substrate is a single crystal.   The crystal phase constituting the crystal substrate is a crystal phase having the same crystal structure as the crystal phase having the highest melting point among the crystal phases constituting the ceramic composite. A method for manufacturing the substrate according to claim 1.   The ceramic composite includes a first crystal phase that emits fluorescence, and is a ceramic composite for light conversion that converts a part of light received by the ceramic composite into light having a wavelength different from that of the received light. The method for manufacturing a substrate according to any one of claims 1 to 5. The ceramic composite includes the first crystal phase including an Ln ₃ Al ₅ O ₁₂ (Ln is at least one element of Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu) phase, and Al. The substrate manufacturing method according to claim 1, comprising a second crystal phase made of ₂ O ₃ . The method for manufacturing a substrate according to claim 1, wherein the crystal substrate is composed of a crystal phase made of Al ₂ O ₃ .   A substrate obtained by the method for manufacturing a substrate according to claim 1. Ln ₃ Al ₅ O ₁₂ (Ln is at least one element of Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu) on a crystal substrate composed of a crystal phase made of Al ₂ O ₃ . A substrate in which a ceramic composite composed of a first crystal phase composed of a phase and a second crystal phase composed of Al ₂ O ₃ is laminated,
The boundary between the crystal substrate and the ceramic composite is composed of an Ln ₃ Al ₅ O ₁₂ (Ln is at least one element of Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu) phase. A substrate characterized by. A light emitting device comprising a substrate obtained by the substrate manufacturing method according to claim 6 and a light emitting element capable of irradiating light excited by a phosphor forming the first crystal phase is manufactured. A method,
A method for manufacturing a light-emitting device, comprising: an element mounting step of mounting the light-emitting element on a substrate including the ceramic composite that has been cooled and crystallized.