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WO2018173172A1 - Procédé de production de nitrure d'aluminium - Google Patents

Procédé de production de nitrure d'aluminium Download PDF

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Publication number
WO2018173172A1
WO2018173172A1 PCT/JP2017/011539 JP2017011539W WO2018173172A1 WO 2018173172 A1 WO2018173172 A1 WO 2018173172A1 JP 2017011539 W JP2017011539 W JP 2017011539W WO 2018173172 A1 WO2018173172 A1 WO 2018173172A1
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Prior art keywords
raw material
aluminum oxide
aluminum nitride
heating
carbon
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English (en)
Japanese (ja)
Inventor
博治 小林
和希 飯田
義政 小林
大和田　巌
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NGK Insulators Ltd
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NGK Insulators Ltd
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Priority to JP2019506811A priority Critical patent/JP6739623B2/ja
Priority to PCT/JP2017/011539 priority patent/WO2018173172A1/fr
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  • This specification discloses the technique regarding the manufacturing method of aluminum nitride.
  • Patent Document 1 Aluminum nitride having a high aspect ratio (average length L / average thickness D) and a method for producing the same are disclosed in Japanese Patent Application Laid-Open No. 2010-138056 (hereinafter referred to as Patent Document 1).
  • Patent Document 1 a mixture obtained by mixing aluminum oxide particles having an aspect ratio of 3 or more and a carbon source (solid carbon) is heated to 1200 ° C. or more under a nitrogen stream to produce aluminum nitride particles having an aspect ratio of 3 or more.
  • the technology is disclosed.
  • Patent Document 1 discloses, as a specific example, an example in which aluminum nitride is manufactured by heating to 1600 ° C. at a temperature rising rate of 200 ° C./hr and holding at 1600 ° C. for 24 hours or 35 hours.
  • Patent Document 1 performs a reductive nitridation reaction using carbon to generate a large number of aluminum nitride crystal nuclei on the surface of the raw material (aluminum oxide particles), thereby maintaining the shape of the raw material (aluminum oxide particles). Manufactures high aspect ratio aluminum nitride particles.
  • Patent Document 1 produces aluminum nitride particles by generating a large number of aluminum nitride crystal nuclei on the surface of a raw material. That is, Patent Document 1 manufactures polycrystalline aluminum nitride particles. This can also be confirmed from the X-ray chart of Patent Document 1.
  • Patent Document 1 uses aluminum nitride particles as a thermally conductive filler such as a semiconductor sealing resin. Therefore, the aluminum nitride particles to be manufactured may be polycrystalline.
  • the present specification provides a technique for producing single crystal aluminum nitride particles having a high aspect ratio.
  • This specification discloses a method for producing single-crystal aluminum nitride having an aspect ratio of 3 or more.
  • a raw material containing aluminum oxide having a plate shape and an aspect ratio of 3 or more and a carbon source may be heated in an atmosphere containing a nitrogen source. Further, when heating the raw material, the raw material may be heated from 900 ° C. to the nitriding temperature at a heating rate of 150 ° C./hr or less.
  • the raw material is heated from 900 ° C. to the nitriding temperature at a heating rate of 150 ° C./hr or less. That is, the rate of temperature rise from when the raw material reaches 900 ° C. until it reaches the nitriding temperature (eg, 1200 ° C. or higher) is controlled to 150 ° C./hr or lower.
  • the nitriding reaction proceeds slowly.
  • the raw material is heated from 900 ° C.
  • the “nitriding temperature” is a temperature for causing the generation of aluminum nitride to proceed, and is a holding time maintained for a predetermined time.
  • the reaction from aluminum oxide to aluminum nitride proceeds as shown in the following formula (1).
  • the raw material When heating, the raw material may be heated under conditions that increase the contact area of the raw material with the nitrogen source as compared with the case where the surface of the raw material is smoothed.
  • the above formula (1) can easily proceed.
  • the manufacturing time of aluminum nitride can be shortened.
  • a large amount of raw materials can be reacted at once. That is, a large amount of aluminum nitride can be produced at a time.
  • it can suppress that reaction shown by following formula (2) advances by increasing the contact area of a raw material and a nitrogen source.
  • aluminum oxide and nitrogen source do not react. Al 2 O 3 + 3C ⁇ Al 2 O + 2CO (2)
  • the raw material may be heated in a state in which the surface of the raw material is provided with irregularities.
  • the surface area of the raw material increases, and the contact area between the raw material and the nitrogen source increases.
  • the contact area between the raw material and the nitrogen source increases.
  • the nitrogen source can easily move to the inside of the raw material through the gap between the raw material and the container (a partition plate separating the inside of the container). As a result, the contact area between the raw material and the nitrogen source increases.
  • the carbon source may be a solid containing carbon or a gas such as a hydrocarbon gas.
  • the carbon source When the carbon source is a solid, the raw material may be heated in a state where the carbon source is mixed with the raw material. By mixing, the carbon source comes into good contact with the raw material, and the reaction represented by the above formula (1) easily proceeds.
  • a carbon source when a carbon source is a gas, compared with the case where a carbon source is a solid, a carbon source contacts a raw material further better.
  • a part containing carbon is arranged in an atmosphere for producing aluminum nitride, and the raw material may be heated in a state where the part is in contact with the raw material. That is, separately from the above-described carbon source (a solid carbon source mixed with a raw material or a gaseous carbon source), or as a carbon source as described above, a carbon part exists in the reaction atmosphere, and the carbon part Heating may be performed in a state where the raw materials are in contact with each other. Also in this case, the reaction shown in the above formula (1) proceeds using a carbon component as a carbon source.
  • the container for storing the raw material during heating may be a carbon part.
  • separates the inside of a container into several compartments may be components made from carbon.
  • the nitrogen source may be nitrogen gas or ammonia gas.
  • ammonia gas as a nitrogen source can shorten the nitriding time (the retention time at the nitriding temperature) compared to the case of using nitrogen gas. It was.
  • a space may be provided below the placement surface on which the raw material is placed.
  • aluminum nitride is generated by the reaction shown in the above formula (1). That is, with the production of aluminum nitride, carbon monoxide is also produced.
  • the generated carbon monoxide moves to the space below. Carbon monoxide can be moved away from the periphery of aluminum nitride, and the reaction represented by the above formula (1) easily proceeds. That is, the nitriding time can be shortened.
  • a schematic diagram of an aluminum nitride manufacturing environment is shown.
  • the top view of an aluminum oxide raw material when a hollow is provided in the surface of the aluminum oxide raw material is shown.
  • Sectional drawing of an aluminum oxide raw material when a hollow is provided in the aluminum oxide raw material is shown.
  • positioned in a container is shown.
  • positioned in a container is shown.
  • An example is shown in which a space is provided below the aluminum oxide raw material. The conditions and results of the examples are shown.
  • Aluminum nitride can be manufactured by heating a raw material containing aluminum oxide and a carbon source in an atmosphere containing a nitrogen source. Specifically, aluminum nitride is produced by a reaction represented by the following formula (1). Al 2 O 3 + 3C + N 2 ⁇ 2AlN + 3CO (1)
  • the raw material containing aluminum oxide only needs to contain aluminum oxide in the raw material, and may be a single aluminum oxide (excluding inevitable impurities) that does not contain other substances, or it may contain other substances in the raw material. May be.
  • the raw material containing aluminum oxide may contain 70% by mass or more of aluminum oxide, may contain 80% by mass or more of aluminum oxide, and contains 90% by mass or more of aluminum oxide. It may contain 95% by mass or more of aluminum oxide.
  • the crystal structure of aluminum oxide may be ⁇ -type, ⁇ -type, ⁇ -type, ⁇ -type, ⁇ -type, etc., and in particular, ⁇ -type and ⁇ -type. In particular, good reactivity can be obtained by using ⁇ alumina, ⁇ alumina, boehmite or the like as aluminum oxide.
  • a raw material containing aluminum oxide is simply referred to as an aluminum oxide raw material.
  • the shape of the aluminum oxide raw material may be a plate shape and may have a high aspect ratio.
  • the aspect ratio may be 3 or more, 5 or more, 10 or more, 30 or more, 50 or more, 70 or more, 100 or more. It may be 120 or more.
  • aluminum nitride having a high aspect ratio aluminum nitride particles
  • an aluminum oxide raw material having a high aspect ratio (aspect ratio of 3 or more).
  • Plate-like high aspect ratio aluminum nitride (aluminum nitride particles) can be oriented by using a doctor blade or the like, and is suitably used as a raw material for products that require control of the crystal axis direction (crystal orientation). be able to.
  • the length L in the plane direction may be 0.2 ⁇ m or more, 0.6 ⁇ m or more, 2 ⁇ m or more, 5 ⁇ m or more, 10 ⁇ m or more. It may be 15 ⁇ m or more. Further, the length L may be 50 ⁇ m or less, 20 ⁇ m or less, 18 ⁇ m or less, or 15 ⁇ m or less.
  • the thickness D may be 0.05 ⁇ m or more, 0.1 ⁇ m or more, 0.3 ⁇ m or more, 0.5 ⁇ m or more, or 0.8 ⁇ m or more. .
  • the thickness D may be 2 ⁇ m or less, 1.5 ⁇ m or less, or 1.0 ⁇ m or less.
  • the size of the aluminum oxide raw material is reflected in the size of the aluminum nitride after synthesis. Therefore, the size of the aluminum oxide raw material can be appropriately selected according to the application of the aluminum nitride to be manufactured.
  • the aspect ratio is indicated by (length L / thickness D).
  • the carbon source is used as a reducing agent for aluminum oxide.
  • the carbon source only needs to be in contact with the aluminum oxide raw material in an environment in which aluminum nitride is synthesized (the aluminum oxide is heated).
  • the carbon source may be a solid mixed with the aluminum oxide raw material.
  • the carbon source may be a hydrocarbon gas supplied in an environment (in a synthesis atmosphere) where aluminum nitride is generated.
  • the carbon source may be a fluoride such as fluorocarbon (CF 4 ) or fluorinated hydrocarbon (CH 3 F 4 ).
  • the carbon source may be a carbon-made component that comes into contact with the aluminum oxide raw material in a synthetic atmosphere, such as a container containing the aluminum oxide raw material, a jig disposed in the container.
  • Carbon black, graphite or the like can be used as a solid carbon source to be mixed with the aluminum oxide raw material.
  • Carbon black, acetylene black, etc. which are obtained by a furnace method, a channel method, etc. can be used for carbon black.
  • the particle size of the carbon black is not particularly limited, but may be 0.001 to 200 ⁇ m.
  • synthetic resin condensates such as phenol resin, melamine resin, epoxy resin, and furan phenol resin, hydrocarbon compounds such as pitch and tar, and organic compounds such as cellulose, sucrose, polyvinylidene chloride, and polyphenylene are used. May be.
  • carbon black is particularly useful from the viewpoint of good reactivity.
  • the aluminum oxide raw material and the solid carbon source When mixing the aluminum oxide raw material and the solid carbon source, a mixture of water, methanol, ethanol, isopropyl alcohol, acetone, toluene, xylene, or the like may be used. The contact state between the aluminum oxide raw material and the carbon source can be improved. Note that after mixing, the mixed raw material may be dried using an evaporator or the like.
  • hydrocarbon gas linear hydrocarbons such as methane, ethane, propane, butane, and ethylene, alcohols such as methanol, ethanol, and propanol, aromatic hydrocarbons such as benzene and naphthalene, and the like can be used.
  • Straight chain hydrocarbons are particularly useful because of their ease of thermal decomposition.
  • hydrocarbon gas as a carbon source, the aluminum oxide raw material and the carbon source are in good contact with each other, and the production time of aluminum nitride can be shortened.
  • nitrogen source nitrogen gas, ammonia gas, and a mixed gas thereof can be used.
  • Ammonia gas is particularly useful as a nitrogen source because it is inexpensive and easy to handle. Further, by using ammonia gas as a nitrogen source, the reactivity is improved and the manufacturing time of aluminum nitride can be shortened.
  • the nitriding temperature (holding temperature) may be 1200 ° C. or higher, 1300 ° C. or higher, 1400 ° C. or higher, 1500 ° C. or higher, or 1600 ° C. or higher. Prolongation of production time and remaining of unreacted aluminum oxide can be prevented.
  • the nitriding temperature may be 1900 ° C. or lower, may be 1800 ° C. or lower, and may be 1700 ° C. or lower. Mismatch of crystal orientation (that is, polycrystallization of aluminum nitride) can be prevented.
  • the nitriding time (holding time) may be 3 hours or longer, 5 hours or longer, or 8 hours or longer from the viewpoint of preventing the remaining unreacted aluminum oxide from remaining.
  • the nitriding time may be 20 hours or less, 15 hours or less, or 10 hours or less from an industrial viewpoint.
  • the temperature increase rate from the temperature at which the reduction nitriding reaction of aluminum oxide starts (900 ° C.) to the nitriding temperature may be 150 ° C./hr or less.
  • the temperature is raised from 900 ° C. to 1600 ° C. at 150 ° C./hr or less, and then maintained at 1600 ° C. for a predetermined time.
  • the temperature increase rate to 900 degreeC may be faster than 150 degreeC / hr.
  • the temperature is increased at a first temperature increase rate (over 150 ° C./hr), and from 900 ° C. to nitriding time, the temperature is increased at a second temperature increase rate (150 ° C./hr or less) Good.
  • a first temperature increase rate over 150 ° C./hr
  • a second temperature increase rate 150 ° C./hr or less
  • the post heat treatment temperature may be 500 ° C. or higher, 600 ° C. or higher, or 700 ° C. or higher from the viewpoint of reliably removing residual carbon. Further, the post-heat treatment temperature may be 900 ° C. or less and may be 800 ° C. or less from the viewpoint of suppressing oxidation of the surface of aluminum nitride.
  • the post heat treatment time can be appropriately selected according to the post heat treatment temperature, and may be, for example, 3 hours or more.
  • aluminum nitride is prepared by placing a container 8 containing an aluminum oxide raw material (or a mixture of an aluminum oxide raw material and a carbon source) 10 in the heating furnace 2, and in the heating furnace 2 from the gas inlet 4.
  • a nitrogen source (or a nitrogen source and a carbon source) is introduced into the aluminum oxide raw material, and the aluminum oxide raw material 10 is heated while discharging the generated gas from the gas discharge port 11.
  • Aluminum nitride is produced by the reaction shown in the above formula (1). Therefore, by increasing the contact area between the aluminum oxide raw material and the carbon source and / or the aluminum oxide raw material and the nitrogen source, the reaction of the formula (1) can easily proceed and the manufacturing time can be shortened.
  • the aluminum oxide raw material and the carbon source and / or the aluminum oxide raw material By heating (nitriding reaction) in an environment where the contact area with the nitrogen source increases, aluminum nitride can be produced in a short time.
  • the contact between aluminum oxide raw materials (particles) can be relatively suppressed by increasing the contact area between the aluminum oxide raw material and the gas (nitrogen source, carbon source). By suppressing contact between the aluminum oxide particles, aggregation of the particles can be suppressed.
  • reaction represented by the following formula (2) reaction in which aluminum nitride is not generated
  • reaction represented by the following formula (2) aluminum oxide remains in the produced aluminum nitride, or a longer reaction time (heating time) is required.
  • a recess 10 a is provided on the surface of the aluminum oxide raw material 10 to increase the area of the aluminum oxide raw material 10 exposed to the furnace space 6 (FIG. 1) (hereinafter referred to as the surface area of the aluminum oxide raw material). It shows the state that was made to.
  • the depression 10a can be created using a rod-shaped jig after the container 8 is filled with the aluminum oxide raw material 10.
  • the recess 10a may be created using a carbon rod-shaped jig, and aluminum nitride synthesis (heating of the aluminum oxide raw material) may be performed while the carbon jig is placed in the recess 10a.
  • a carbon jig can be used as the carbon source of the above formula (1).
  • the area of the surface of the aluminum oxide raw material 10 becomes large, so that there are many hollows 10a.
  • the number and size of the recesses 10a may be adjusted so that the area of the surface of the aluminum oxide raw material 10 becomes twice or more as compared with the case where no recess is provided on the surface of the aluminum oxide raw material 10.
  • a stripe-like or lattice-like groove may be formed on the surface of the aluminum oxide raw material 10. That is, irregularities may be formed on the surface of the aluminum oxide raw material 10.
  • FIGS. 4 and 5 show a state in which a partition plate 12 for separating the inside of the container into a plurality of sections is arranged in the container 8.
  • the aluminum oxide raw material 10 is separated into a plurality in the container 8 by the partition plate 12.
  • the nitrogen source when the carbon source is a gas, the nitrogen source and the carbon source
  • the partition plate 12 By disposing the partition plate 12 in the container 8, the nitrogen source (when the carbon source is a gas, the nitrogen source and the carbon source) pass through the gap between the aluminum oxide raw material 10 and the partition plate 12, and the aluminum oxide raw material 10. Move to the inside (deep part).
  • the aluminum oxide raw material 10 and the nitrogen source (or the nitrogen source and the carbon source) are in good contact, and aluminum nitride can be produced in a short time. This method is particularly useful when the amount of aluminum nitride produced is large.
  • the partition plate 12 can be used as a part of carbon source of the said Formula (1) by using the partition plate 12 made from carbon.
  • FIG. 6 shows a state where the furnace gas is introduced into the container 8 through the gas introduction pipe 14 and the aluminum oxide raw material 10 is suspended.
  • the aluminum oxide raw material 10 and the nitrogen source or the nitrogen source and the carbon source
  • the same effect can be obtained by spraying a nitrogen source (or a nitrogen source and a carbon source) on the surface of the aluminum oxide raw material 10 to float the aluminum oxide raw material 10.
  • the same effect can be obtained even when the aluminum oxide raw material 10 is heated while floating using a heating kiln such as a rotary kiln whose inner wall rotates.
  • FIG. 7 shows a state in which the partition plate 16 is disposed in the container 8 and a space 20 is formed below the container 8.
  • a communication port 18 that communicates with the space 20 is provided on the side surface of the container 8.
  • the upper and lower portions (space 20) of the partition plate 16 are configured so that the gas can move.
  • the aluminum oxide raw material 10 is filled in the container 8 on the partition plate 16. That is, the partition plate 16 constitutes a placement surface on which the aluminum oxide raw material 10 is placed.
  • carbon monoxide generated by the reaction shown in the above formula (1) moves to the space 20 and the carbon monoxide concentration around the aluminum oxide raw material 10 decreases. As a result, the reaction shown in the above formula (1) is promoted, and aluminum nitride can be produced in a short time.
  • the partition plate 16 may be made of carbon.
  • Shortening the manufacturing time has a positive effect on the shape of the aluminum nitride produced, in addition to industrial efficiency. For example, by shortening the production time, aggregation of aluminum nitride particles (flat aluminum nitride) can be suppressed. For example, generation of voids or the like in the aluminum nitride particles can be suppressed by shortening the manufacturing time.
  • the aluminum nitride particles can be maintained in a desired shape. That is, aluminum nitride particles can be produced while maintaining the shape of the aluminum oxide particles.
  • Example 1 First, 200 g of plate-shaped aluminum oxide (Kinsei Matec Co., Ltd.), 100 g of carbon black (Mitsubishi Chemical Co., Ltd.), 2000 g of alumina cobblestone (2 mm ⁇ ), 700 mL of IPA (isopropyl alcohol: Tokuyama Co., Ltd., Tokso IPA) The mixture was pulverized and mixed at 30 rpm for 240 minutes to obtain a mixture. Aluminum oxide having an average particle diameter of 5 ⁇ m, an average thickness of 0.07 ⁇ m, and an aspect ratio of 70 was used. The alumina cobblestone was removed from the resulting mixture, and the mixture was dried using a rotary evaporator.
  • IPA isopropyl alcohol: Tokuyama Co., Ltd., Tokso IPA
  • the remaining mixture (synthetic raw material) was lightly pulverized in a mortar, and 200 g was filled into a carbon crucible (outer diameter ⁇ 250 mm, inner diameter ⁇ 240 mm, height 55 mm). Thereafter, the crucible filled with the raw material for synthesis was placed in a heating furnace and heated at 1600 ° C. under a nitrogen gas flow of 3 L / min. In addition, the sample produced 3 samples (heating time 10 hours, 15 hours, 20 hours) from which heating time (1600 degreeC holding time) differs. The temperature raising conditions were 200 ° C./hr from room temperature to 900 ° C., and 150 ° C./hr from 900 ° C. to 1600 ° C.
  • the sample was naturally cooled, a sample was taken out from the crucible, and heat treated (post-heated) at 650 ° C. for 10 hours in an oxidizing atmosphere using a muffle furnace to obtain a plate-like aluminum nitride powder.
  • the post heat treatment was performed to remove carbon remaining in the sample.
  • the shape (average particle diameter, average thickness, aspect ratio) of the aluminum nitride powder is the raw material (plate-like oxidation) Aluminum).
  • the crystallization form and the reaction rate (nitriding rate of aluminum oxide) were evaluated by the method demonstrated below.
  • the crystal form was evaluated on the front or back surface of aluminum nitride. That is, the crystal form was evaluated for the surface (front surface or back surface) orthogonal to the thickness direction of the aluminum nitride powder and having the largest area among the surfaces constituting the aluminum nitride powder. Specifically, the front surface (or back surface) of aluminum nitride was mapped for each crystal orientation, and the ratio (area ratio) of the (001) plane in the whole was calculated to determine whether it was single crystal or polycrystal. When the area ratio was 80% or more, it was judged as a single crystal (crystal orientation was uniform), and when it was less than 80%, it was judged as polycrystal (crystal orientation was not uniform). The results are shown in FIG.
  • XRD X-ray diffractometer
  • a case where the reaction rate reaches 100% is shown as an evaluation C, and a case where the reaction is rejected is also shown as a evaluation D.
  • the aluminum nitride powder obtained in this example was a single crystal. It was also confirmed that the reaction rate reached 100% by heating for 20 hours.
  • Example 2 Examination of nitrogen source
  • the same raw material (synthetic raw material) as in Example 1 was prepared, ammonia gas was circulated in the heating furnace instead of nitrogen gas, the same heating conditions and post heat treatment as in Example 1 were performed, and samples (3 samples) were produced. .
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. It was also confirmed that the reaction rate reached 100% by heating for 15 hours. That is, it was confirmed that the reaction rate (reaction rate) was improved by using ammonia gas as a nitrogen source (see Example 1 for comparison).
  • Example 3 Examination of carbon source
  • 200 g of the plate-like aluminum oxide used in Example 1 was filled in the crucible used in Example 1, and the same heating conditions and post-heating treatment as in Example 1 were performed to prepare samples (3 samples). That is, the raw material for synthesis does not contain carbon black but is aluminum oxide itself.
  • ethylene gas hydrocarbon gas
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. It was also confirmed that the reaction rate reached 100% by heating for 15 hours. That is, it was confirmed that the reaction rate (reaction rate) was improved by using ethylene gas as the carbon source (see Example 1 for comparison).
  • Comparative Examples 1, 2 and 3 differ from Examples 1, 2 and 3 in that the temperature rising rate was 200 ° C./hr from room temperature to 1600. That is, Comparative Examples 1 to 3 have a higher temperature increase rate after 900 ° C. than Examples 1 to 3.
  • the samples of Comparative Examples 1 to 3 were all polycrystalline with heating times of 10 hours, 15 hours, and 20 hours. Even when the nitrogen source was changed from nitrogen gas to ammonia gas (Comparative Examples 1 and 2) and the carbon source was changed from carbon to ethylene gas (Comparative Examples 1 and 3), no improvement in the reaction rate was observed. . That is, in Comparative Examples 1 to 3, even when heated for 20 hours, alumina remained in the sample, and the reaction rate was unacceptable.
  • Example 4 Study of synthesis environment 1
  • the same mixture (synthetic raw material) as in Example 1 was prepared, and while the nitrogen gas was blown onto the synthetic raw material, the same heating conditions and post-heating treatment as in Example 1 were performed to prepare samples (3 samples). That is, aluminum nitride was synthesized while the synthesis raw material was suspended.
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. Moreover, it was confirmed that the reaction rate becomes 100% by heating for 10 hours. That is, it was confirmed that the reaction rate (reaction rate) was improved by performing the synthesis while floating the synthesis raw material and increasing the contact area between the aluminum oxide and the nitrogen source.
  • Example 5 Study of synthesis environment 2
  • Example 5 Study of synthesis environment 2
  • the same raw material for synthesis as in Example 1 is filled in the same crucible as in Example 1, depressions of ⁇ 15 mm and depth of 20 mm are formed at 20 locations on the surface of the raw material for synthesis.
  • Heat treatment was performed to prepare samples (3 samples).
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. It was also confirmed that the reaction rate reached 100% by heating for 10 hours. Confirmed that the reaction rate (reaction rate) is improved by forming a depression on the surface of the raw material for synthesis, increasing the surface area of the raw material for synthesis, and increasing the contact area between the aluminum oxide and the nitrogen source. It was done.
  • Example 6 Examination of synthesis environment 3
  • a carbon partition plate that partitions the inside of the crucible into approximately 50 mm squares is disposed, and the same raw materials for synthesis as in Example 1 are filled in the partitioned crucible.
  • the same heating conditions and post-heating treatment were performed to prepare samples (3 samples).
  • the height of the partition plate was 50 mm.
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. It was also confirmed that the reaction rate reached 100% by heating for 10 hours.
  • reaction rate reaction rate
  • carbon (partition plate) in contact with alumina increases and the reaction rate (reaction rate) is improved by heating in a state where the carbon partition plates are arranged.
  • Example 7 Study of synthesis environment 4
  • Four carbon cubes (10 mm cube shape) are arranged in the crucible used in Example 1, a carbon setter having a diameter of 200 mm and a thickness of 10 mm is arranged on the cube, and the same as Experimental Example 1 on the setter.
  • the raw materials for synthesis were placed, and the same heating conditions and post-heating treatment as in Example 1 were performed to prepare samples (3 samples). That is, the synthesis raw material was heated (synthesized) with a space provided below the synthesis raw material.
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal.
  • reaction rate reached 100% by heating for 10 hours. That is, by forming a space below the synthesis raw material and keeping the carbon monoxide generated in the above formula (1) away from the periphery of the synthesis raw material, the reaction of the above formula (1) can easily proceed and the reaction rate ( It was confirmed that the reaction rate was improved.
  • Example 8 Examination of synthesis environment 5
  • Example 6 a carbon partition plate that partitions the inside of the crucible into approximately 50 mm squares was placed in the crucible used in Example 1.
  • 200 g of the plate-like aluminum oxide used in Example 1 was filled in the crucible as it was, and the same heating conditions and post-heating treatment as in Example 1 were performed to prepare samples (3 samples).
  • no carbon source carbon black
  • no gaseous carbon source hydrogen is supplied to the synthetic raw material.
  • Carbon sources are only crucibles and partition plates.
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG.
  • Example 9 Study of synthesis environment 6
  • a carbon partition plate was placed in the crucible, and 200 g of plate-like aluminum oxide was filled in the crucible as it was, and the same heating conditions and post-heating treatment as in Example 1 were performed.
  • Samples (3 samples) were prepared.
  • ammonia gas was circulated in the heating furnace instead of nitrogen.
  • the evaluation result of the obtained sample is shown in FIG.
  • FIG. 8 it was confirmed that the obtained aluminum nitride powder was a single crystal.
  • the reaction rate reached 100% by heating for 15 hours. That is, the reaction rate was improved by using ammonia gas instead of nitrogen (see comparative example 8). Also from this example, it was confirmed that the reaction rate (reaction rate) was improved by using ammonia gas as the nitrogen source.
  • Example 10 Study of synthesis environment 7
  • a carbon partition plate was placed in the crucible, 200 g of plate-like aluminum oxide was filled as it was, and the same heating conditions and post-heating treatment as in Example 1 were performed.
  • Samples (3 samples) were prepared.
  • ethylene gas was added as a carbon source.
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. It was also confirmed that the reaction rate reached 100% by heating for 15 hours. That is, the reaction rate was improved by adding ethylene gas (see Example 8 for comparison).
  • Example 11 Study of synthesis environment 8
  • 200 g of plate-like aluminum oxide was filled in the crucible as it was, and the same heating conditions and post-heating treatment as in Example 1 were performed to prepare samples (3 samples).
  • no partition plate is disposed in the crucible. Instead of arranging the partition plate, heating was performed while blowing nitrogen gas to the raw material.
  • the evaluation result of the obtained sample is shown in FIG. As shown in FIG. 8, it was confirmed that the obtained aluminum nitride powder was a single crystal. Further, as in Example 10, it was also confirmed that the reaction rate reached 100% by heating for 15 hours. That is, it was confirmed that the reaction rate (reaction rate) was improved by increasing the contact area between the raw material and nitrogen gas (nitriding source).
  • Example 12 to 15 Examination of nitrogen source 2
  • ammonia gas was used in place of nitrogen as the nitriding source of Examples 4, 5, 6, and 7, respectively.
  • the synthesis environment, heating conditions, post-heating treatment, and the like of Examples 12 to 15 are the same as those of Examples 4 to 7, respectively.
  • FIG. 8 it was confirmed that the obtained aluminum nitride powder was a single crystal and that the reaction rate was 100% by heating for 10 hours.
  • reaction rate is reduced by heating under conditions where the contact area between the synthetic raw material and the nitrogen source is increased compared to the case where the synthetic raw material is simply filled in the crucible (the surface of the synthetic raw material is smooth). Increased (Example 1 and Examples 4-7, Example 2 and Examples 12-15, Example 3 and Example 11).
  • reaction rate increased when ammonia gas was used as a nitrogen source rather than nitrogen gas (Examples 1 and 2, Examples 8 and 9). Further, the reaction rate was increased by supplying hydrocarbon gas as a carbon source rather than mixing carbon in the synthetic raw material (Examples 1 and 3). That is, it was confirmed that aluminum nitride was generated by supplying a hydrocarbon gas to aluminum oxide without preparing a synthetic raw material by mixing aluminum oxide and carbon.

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Abstract

L'invention concerne un procédé de production de nitrure d'aluminium monocristallin ayant un rapport d'aspect d'au moins 3. Dans ce procédé de production, une source de carbone et une matière première contenant de l'oxyde d'aluminium qui est sous forme de plaque et a un rapport d'aspect d'au moins 3 sont chauffées dans une atmosphère contenant une source d'azote. Pendant le chauffage, la matière première est portée de 900 °C jusqu'à la température de nitruration, à une vitesse d'élévation de température inférieure ou égale à 150 °C/h.
PCT/JP2017/011539 2017-03-22 2017-03-22 Procédé de production de nitrure d'aluminium Ceased WO2018173172A1 (fr)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63151605A (ja) * 1986-12-16 1988-06-24 Nippon Light Metal Co Ltd 窒化アルミニウム粉体の製造方法
JPH01100006A (ja) * 1987-10-14 1989-04-18 Nippon Light Metal Co Ltd 窒化アルミニウム粉体の製造方法
JPH01160812A (ja) * 1987-12-16 1989-06-23 Nippon Light Metal Co Ltd 窒化アルミニウム粉体の製造法
JPH05330807A (ja) * 1991-04-26 1993-12-14 Nippon Light Metal Co Ltd 焼結用窒化アルミニウム粉末体及びその製造法
JP2005132699A (ja) * 2003-10-31 2005-05-26 Ngk Insulators Ltd 窒化アルミニウム単結晶の製造方法
JP2006045047A (ja) * 2004-07-08 2006-02-16 Ngk Insulators Ltd 窒化アルミニウム単結晶の製造方法
JP2010138056A (ja) * 2008-12-15 2010-06-24 Mitsubishi Chemicals Corp 高アスペクト比を有する窒化アルミニウム、その製造方法、それを用いた樹脂組成物

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63151605A (ja) * 1986-12-16 1988-06-24 Nippon Light Metal Co Ltd 窒化アルミニウム粉体の製造方法
JPH01100006A (ja) * 1987-10-14 1989-04-18 Nippon Light Metal Co Ltd 窒化アルミニウム粉体の製造方法
JPH01160812A (ja) * 1987-12-16 1989-06-23 Nippon Light Metal Co Ltd 窒化アルミニウム粉体の製造法
JPH05330807A (ja) * 1991-04-26 1993-12-14 Nippon Light Metal Co Ltd 焼結用窒化アルミニウム粉末体及びその製造法
JP2005132699A (ja) * 2003-10-31 2005-05-26 Ngk Insulators Ltd 窒化アルミニウム単結晶の製造方法
JP2006045047A (ja) * 2004-07-08 2006-02-16 Ngk Insulators Ltd 窒化アルミニウム単結晶の製造方法
JP2010138056A (ja) * 2008-12-15 2010-06-24 Mitsubishi Chemicals Corp 高アスペクト比を有する窒化アルミニウム、その製造方法、それを用いた樹脂組成物

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