JPH0535682B2 - - Google Patents
Info
- Publication number
- JPH0535682B2 JPH0535682B2 JP63198800A JP19880088A JPH0535682B2 JP H0535682 B2 JPH0535682 B2 JP H0535682B2 JP 63198800 A JP63198800 A JP 63198800A JP 19880088 A JP19880088 A JP 19880088A JP H0535682 B2 JPH0535682 B2 JP H0535682B2
- Authority
- JP
- Japan
- Prior art keywords
- alumina
- powder
- particle size
- aln
- mixture
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 72
- 239000000843 powder Substances 0.000 claims description 57
- 239000002245 particle Substances 0.000 claims description 35
- 239000002243 precursor Substances 0.000 claims description 28
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 26
- 229910052799 carbon Inorganic materials 0.000 claims description 25
- 239000000203 mixture Substances 0.000 claims description 24
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 10
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims description 7
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 claims description 7
- 238000005121 nitriding Methods 0.000 claims description 6
- 230000001590 oxidative effect Effects 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 239000012298 atmosphere Substances 0.000 claims description 4
- 238000010304 firing Methods 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 description 18
- 238000009826 distribution Methods 0.000 description 13
- 230000007704 transition Effects 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 229910001593 boehmite Inorganic materials 0.000 description 5
- 239000006185 dispersion Substances 0.000 description 5
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 5
- 230000006911 nucleation Effects 0.000 description 5
- 238000010899 nucleation Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 230000002159 abnormal effect Effects 0.000 description 4
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 4
- 239000007858 starting material Substances 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 239000003513 alkali Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000005261 decarburization Methods 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 229910018626 Al(OH) Inorganic materials 0.000 description 1
- 229910002706 AlOOH Inorganic materials 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- -1 aluminum alkoxide Chemical class 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000008394 flocculating agent Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 239000008240 homogeneous mixture Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Description
〔産業上の利用分野〕
本発明は、高純度かつ微細で易焼結性の窒化ア
ルミニウム粉末の製造方法に関し、さらに詳しく
は窒化アルミニウム粉末の粒径の制御が可能で粒
度分布を狭くすることができると共に、再現性が
よく、窒化アルミニウム粉末中に残存する炭素も
少なくすることができる方法に関するものであ
る。
〔従来の技術〕
窒化アルミニウム（以下AlNと記す）は、そ
の優れた機械的特性、化学的耐用性の故に耐熱材
料として用いられるだけでなく、その高熱伝導
性、高電気絶縁性、低誘電率等の故に半導体関係
の放熱材料としても期待されている。AlNは一
部薄膜の形態で利用される場合もあるが、多くの
場合焼結体で用いられている。
このようなAlN焼結体の焼結性および特性は、
出発原料であるAlN粉末の特性および焼結助剤
に強く影響されることが知られている。すなわ
ち、AlN粉末としては、高純度で、粒径が均一
かつ微細であり、適当な焼結助剤をAlN粉末中
に均一に分散し得ることが望ましい。
AlN粉末は、従来、金属アルミニウムの直接
窒化法またはアルミナの還元窒化法で製造されて
いる。還元窒化法では微細で均一な粒径の高純度
アルミナを出発原料とすることにより直接窒化法
より若干優れたAlN粉末が得られやすいが、所
望の粉末とは言い難い。
上記方法を改良し、高純度で、微細、均一粒径
のAlN粉末を得る方法として、アルミニウムア
ルコキシドと炭素との分散液に水を加え、アルコ
キシドの加水分解を行わせ水酸化アルミニウムと
炭素との混合物を得る方法、および水溶性アルミ
ニウム塩と炭素とを含む水溶性にアルカリを加
え、中和沈殿法により水酸化アルミニウムと炭素
との混合物を得る方法（特開昭61−6105、特公昭
61−26485）、さらに分散性、分散液の安定性に優
れるベーマイト（AlOOH）または、凝ベーマイ
ト粉を用い、炭素源物質との均一な分散液を作製
し、この均一分散状態を保つたまま固化させ、均
一な混合物を得る方法（特開昭61−283206）が提
案されている。
これらの方法によつて得た混合物は、前記した
アルミナと炭素との混合物に比べ均一に混合され
ているため、これを窒素を含む非酸化性雰囲気中
で焼成することにより、従来より均一で、微細な
AlN粉を得ることができるようになつた。
しかし、これらの改良法においても下記問題点
が残されていた。すなわち、水酸化アルミニウム
など、昇温によつてα−アルミナを生成する物質
（以下α−アルミナ前駆体と呼ぶ）は、α−アル
ミナへの相転移時に粒径の異常成長が起こる。こ
のため、例えば、超微粉のベーマイトを出発原料
として用いても粗大なα−アルミナとなつてしま
う場合があり、環元窒化後のAlN粉末にも1μm以
上の粗大なものが認められたり、AlN粉末の粒
度分布が変動する場合も見られ、微細で粒度分布
範囲の狭い良質のAlN粉末を再現性よく製造す
る際の問題点の１つとして残されていた。さらに
上記の相転移の際に粒成長が極めて急激に起こる
ために、共存する炭素源物質がアルミナ粒内に多
数トラツプされ、環元窒化反応後も多量に残留す
ることが分つた。この粒内残留炭素は環元窒化反
応後の酸化脱炭工程でも酸化除去するのが難し
く、最終的に得られるAlN粉末中の残留炭素が
比較的高い場合が多いという問題がある。
〔発明が解決しようとする問題点〕
本発明は高純度で微細な、焼結性にすぐれた
AlN粉末の製造法に関する上記開示をさらに発
展させ、粒度分布範囲が狭く、微細で、残留炭素
の少ないAlN粉末を再現性よく製造する方法を
提供しようとするものである。
〔問題点を解決するための手段〕
高純度で微細な、優れた焼結性を有するAlN
粉末を安定に再現性よく製造する方法として、本
発明は次の技術手段から成る。
(1) アルミニウム塩、水酸化アルミニウム、準安
定相アルミナ（γ−アルミナ、θ−アルミナな
ど）などの加熱によつてα−アルミナに変化す
るα−アルミナ前駆体（ベーマイトを除く）と
炭素源物質を均一に混合し、この混合物にアル
ミナ前駆体に対して、0.01〜50重量％のα−ア
ルミナ粉末を加える。
上記の順序の他、α−アルミナ前駆体にα−
アルミナを加えた後、炭素源物質と混合するな
ど混合の順序はいずれでもよいが、α−アルミ
ナ添加の効果を十分に発揮させるには、α−ア
ルミナ前駆体とのα−アルミナの混合を十分に
行うことが重要である。
α−アルミナの粒径は得ようとするAlN粉
末の粒径によつて変え、微細なAlN粉末を得
ようとする場合には、微細なα−アルミナ粉末
を用いる。
(2) α−アルミナ前駆体と混合する炭素源物質の
量はα−アルミナ前駆体に対して0.2〜3.0の重
量比になるようにする。
(3) 混合物を均一性を保持したまま固化させ、乾
燥した後、窒素を含む非酸化性雰囲気中で1350
〜1800℃で焼成する。
混合物の均一性を保持したまま固化させるに
は、加熱による水分の除去、遠心脱水機等によ
る分離、混合物の酸、アルカリによるゲル化等
により行う。
本発明はα−アルミナ前駆体（ベーマイトを除
く）にα−アルミナをα−アルミナ前駆体に対し
て、0.01〜50重量％となるように添加し、均一に
混合する。この混合物と炭素源物質を所定の割合
で加え、均一に混合する。この混合物を均一性を
保持したまま固化させ、乾燥させた後、窒素を含
む非酸化性雰囲気中で1350〜1800℃で焼成して
AlN粉を得る。
上記混合物を均一性を保持したまま、固化させ
る手段としては次の(イ)〜(ニ)の４通りが代表的であ
る。
(イ) 長時間混練する
(ロ) 混練しながら加熱等により水を蒸発させ
る。
(ハ) 酸、遠心脱水機等により、強制的に水を除
去する。
(ニ) 酸、アルカリ、種々のイオン、高分子凝集
剤等を添加する。
〔作用〕
α−アルミナ前駆体は焼成における昇温時に、
一旦α−アルミナ相に転移し、この転移の際に粒
子の異常成長が起こるが、微粉のα−アルミナ粉
末を添加しておくと、添加したα−アルミナ粉末
はα−アルミナ前駆体からα−アルミナへの転移
に際し核生成サイトとして作用し、粒子の異常成
長を防ぐことができる。
アルミナにはα−アルミナの他に、γ−アルミ
ナ等の準安定相があるが、準安定相のアルミナに
は上記の核生成サイトとしての作用が認められな
いばかりでなく、昇温時にα−アルミナ相に転移
する時にα−アルミナ前駆体と同様に粒子が異常
成長し、その結果AlNの粗粒を生じ、本発明の
効果を挙げることはできない。
α−アルミナ前駆体と炭素源物質との混合物に
含有させるα−アルミナ粉末の量は、α−アルミ
ナ前駆体に対し0.01〜50重量％とする。0.01重量
％未満では核生成サイト数が不十分で、前記転移
に伴う急激な粒成長を抑制できず、50重量％を越
えると、分散性が良く、かつ微細な粒径を有する
α−アルミナ前駆体を用いる利点が殆どなく、α
−アルミナ粉末を出発原料とする従来の技術と実
質的に同じものになる。
本発明に用いられるα−アルミナ粉末の粒度は
平均粒径2μm以下とする。これはα−アルミナ前
駆体からα−アルミナへの転移に際し、添加した
α−アルミナが核生成サイトとなるものであり、
多数の核生成サイトを持ち込んで微粉のAlN粉
末を生じさせるため、また、添加したα−アルミ
ナ粉末も炭素源物質と窒素とによつて環元窒化さ
れてAlN粉末を生じるので製造しようとする
AlN粉末より粒径の小さいものが望ましく、α
−アルミナ粉末の平均粒径を選択することによ
り、粒度分布の狭いAlN粉末を製造するために
必要である。
また、本発明においては、α−アルミナ前駆体
からα−アルミナへの相転移において粒の異常成
長を生じないので、炭素源物質がα−アルミナ粒
内に多数トラツプされることがなくなり、酸化脱
炭工程における炭素の酸化除去が容易となり、
AlN粉末製品中の残留炭素を減少させることが
できる
〔実施例〕
実施例 １
第１表に示した〜の配合でAlN粉末製造
用の混合物を作製し、窒素雰囲気中で1600℃、５
時間焼成したのち、650℃で３時間脱炭処理し、
AlN粉末を得た。α−アルミナ前駆体には水酸
化アルミニウムAl（OH）3を用いた。第１表中，
，，，は本発明の製造条件に適合する実
施例であり、，，，は比較例である。
これ等の混合物は、全て以下の手順で作製し
た。
水中に分散させた濃度20重量％のα−アルミナ
前駆体と、固体炭素粉に分散剤と水を加えポツト
ミルで10時間混練して得た炭素濃度15重量％の分
散体とを予め作製した。
両者を炭素とα−アルミナ前駆体との重量比が
１となるように混合したのち、水中に分散させ、
濃度10重量％のα−アルミナ粉末（平均粒径
0.3μm）を所定量添加混合し、加熱によつて水を
除去し、ゲル化させた後乾燥した。
以上のAlN粉末製造試験は各条件でそれぞれ
５回行つた。
上記〜の９種類のAlN粉末の粒度分布の
平均値を第１図に示した。第１図および走査型電
子顕微鏡による観察から以下のことを確認でき
た。
比較例，，，では粒径分布が広く、平
均粒径も大きいだけでなく、5μm以上まで異常成
長した粒が散見された。
実施例，，，，では比較例，，
，に比べ、粒径が小さく、粒度分布が狭く、
異常成長した粒は認められず、かつ５回の試験の
間の粒径のばらつきも小さい。
実施例 ２
α−アルミナ前駆体として塩化アルミニウム
AlCl3を用いて、第１表に示した〜の配合で
AlN粉末製造用の混合物を作製し、窒素雰囲気
中で1600℃、５時間焼成したのち、650℃で３時
間脱炭処理し、AlN粉末を得た。第１表中，
，，，は本発明の製造条件に適合する実
施例であり、，，，は比較例である。
これ等の混合物を、実施例１と同じ手順によつ
てAlN粉末を作製した。以上のAlN粉末製造試
験は各条件でそれぞれ５回行つた。
上記〜の９種類のAlN粉末の粒度分布の
平均値を第２図に示した。第２図および走査型電
子顕微鏡による観察から以下のことを確認でき
た。
比較例，，，では粒径分布が広く、平
均粒径も大きいだけでなく、5μm以上まで異常成
長した粒が散見された。
実施例，，，，では比較例，，
，に比べ、粒径が小さく、粒度分布が狭く、
異常成長した粒は認められず、かつ５回の試験の
間の粒径のばらつきも小さい。
[Industrial Application Field] The present invention relates to a method for producing aluminum nitride powder that is highly pure, fine, and easily sinterable, and more specifically, the present invention relates to a method for producing aluminum nitride powder that is highly pure, fine, and easy to sinter. The present invention relates to a method that is capable of producing aluminum nitride powder, has good reproducibility, and can reduce the amount of carbon remaining in aluminum nitride powder. [Prior Art] Aluminum nitride (hereinafter referred to as AlN) is not only used as a heat-resistant material because of its excellent mechanical properties and chemical durability, but also because of its high thermal conductivity, high electrical insulation, and low dielectric constant. For these reasons, it is also expected to be used as a heat dissipation material for semiconductors. Although AlN is sometimes used in the form of a thin film, it is often used in the form of a sintered body. The sinterability and properties of such AlN sintered bodies are
It is known that this is strongly influenced by the properties of the starting material AlN powder and the sintering aid. That is, it is desirable that the AlN powder has high purity, uniform and fine particle size, and that an appropriate sintering aid can be uniformly dispersed in the AlN powder. AlN powder has conventionally been produced by direct nitriding of metal aluminum or reductive nitriding of alumina. In the reductive nitriding method, AlN powder that is slightly better than the direct nitriding method is easily obtained by using high-purity alumina with fine and uniform particle size as a starting material, but it is difficult to say that it is the desired powder. As a method to improve the above method and obtain AlN powder with high purity, fine, and uniform particle size, water is added to a dispersion of aluminum alkoxide and carbon, and the alkoxide is hydrolyzed to form a mixture of aluminum hydroxide and carbon. A method for obtaining a mixture, and a method for obtaining a mixture of aluminum hydroxide and carbon by adding an alkali to a water-soluble solution containing a water-soluble aluminum salt and carbon and using a neutralization precipitation method (Japanese Patent Laid-Open No. 61-6105,
61-26485), use boehmite (AlOOH) or coagulated boehmite powder, which has excellent dispersibility and stability of the dispersion liquid, to create a uniform dispersion liquid with the carbon source material, and solidify it while maintaining this uniform dispersion state. A method has been proposed (Japanese Patent Application Laid-open No. 283206/1983) to obtain a homogeneous mixture. The mixtures obtained by these methods are more uniformly mixed than the above-mentioned mixtures of alumina and carbon, so by firing them in a non-oxidizing atmosphere containing nitrogen, they are more uniform than before. minute
It is now possible to obtain AlN powder. However, even in these improved methods, the following problems remain. That is, in substances such as aluminum hydroxide that produce α-alumina upon temperature elevation (hereinafter referred to as α-alumina precursors), abnormal growth in particle size occurs during phase transition to α-alumina. For this reason, for example, even if ultrafine boehmite powder is used as a starting material, it may turn into coarse α-alumina, and coarse particles of 1 μm or more may be observed in AlN powder after ring nitridation, or AlN In some cases, the particle size distribution of the powder fluctuated, which remained one of the problems in producing fine, high-quality AlN powder with a narrow particle size distribution range with good reproducibility. Furthermore, it was found that because grain growth occurs extremely rapidly during the above-mentioned phase transition, a large number of coexisting carbon source substances are trapped within the alumina grains, and a large amount remains even after the ring element nitridation reaction. This intragranular residual carbon is difficult to oxidize and remove even in the oxidative decarburization step after the ring element nitriding reaction, and there is a problem that the residual carbon in the finally obtained AlN powder is often relatively high. [Problems to be solved by the invention] The present invention provides highly pure and fine particles with excellent sinterability.
The present invention further develops the above-mentioned disclosure regarding the method for producing AlN powder, and attempts to provide a method for producing AlN powder that has a narrow particle size distribution range, is fine, and has little residual carbon with good reproducibility. [Means to solve the problem] High purity, fine AlN with excellent sinterability
As a method for stably producing powder with good reproducibility, the present invention consists of the following technical means. (1) α-alumina precursors (excluding boehmite) and carbon source substances that are converted into α-alumina by heating, such as aluminum salts, aluminum hydroxide, metastable phase alumina (γ-alumina, θ-alumina, etc.) are mixed uniformly, and 0.01 to 50% by weight of α-alumina powder is added to the mixture based on the alumina precursor. In addition to the above order, α-alumina precursor
Any order of mixing may be used, such as adding alumina and then mixing with the carbon source material, but in order to fully demonstrate the effect of adding α-alumina, it is necessary to mix α-alumina with the α-alumina precursor sufficiently. It is important to do so. The particle size of α-alumina is changed depending on the particle size of the AlN powder to be obtained, and if fine AlN powder is to be obtained, fine α-alumina powder is used. (2) The amount of carbon source material to be mixed with the α-alumina precursor is adjusted to a weight ratio of 0.2 to 3.0 to the α-alumina precursor. (3) After solidifying the mixture while maintaining its homogeneity and drying, it was heated at 1350 °C in a non-oxidizing atmosphere containing nitrogen.
Bake at ~1800℃. In order to solidify the mixture while maintaining its homogeneity, removal of moisture by heating, separation using a centrifugal dehydrator or the like, gelling of the mixture with acid or alkali, etc. are performed. In the present invention, α-alumina is added to an α-alumina precursor (excluding boehmite) in an amount of 0.01 to 50% by weight based on the α-alumina precursor, and mixed uniformly. This mixture and the carbon source material are added at a predetermined ratio and mixed uniformly. This mixture is solidified while maintaining its uniformity, dried, and then calcined at 1350-1800℃ in a non-oxidizing atmosphere containing nitrogen.
Obtain AlN powder. The following four methods (a) to (d) are typical for solidifying the above mixture while maintaining its uniformity. (a) Knead for a long time (b) Evaporate water by heating while kneading. (c) Forcibly remove water using acid, centrifugal dehydrator, etc. (d) Adding acids, alkalis, various ions, polymer flocculants, etc. [Function] When the α-alumina precursor is heated during firing,
Once it transitions to the α-alumina phase, abnormal particle growth occurs during this transition, but if fine α-alumina powder is added, the added α-alumina powder will change from the α-alumina precursor to the α- It acts as a nucleation site during the transition to alumina, and can prevent abnormal growth of particles. In addition to α-alumina, alumina has metastable phases such as γ-alumina, but metastable alumina not only does not function as the above-mentioned nucleation site, but also has α-alumina when heated. During the transition to the alumina phase, particles grow abnormally like the α-alumina precursor, resulting in coarse AlN particles, making it impossible to achieve the effects of the present invention. The amount of α-alumina powder contained in the mixture of α-alumina precursor and carbon source material is 0.01 to 50% by weight based on the α-alumina precursor. If it is less than 0.01% by weight, the number of nucleation sites is insufficient and the rapid grain growth accompanying the transition cannot be suppressed, and if it exceeds 50% by weight, the α-alumina precursor has good dispersibility and a fine particle size. There is almost no advantage of using the body, α
- It becomes substantially the same as the conventional technology using alumina powder as a starting material. The particle size of the α-alumina powder used in the present invention is set to an average particle size of 2 μm or less. This is because the added α-alumina becomes a nucleation site during the transition from α-alumina precursor to α-alumina.
In order to produce fine AlN powder by introducing a large number of nucleation sites, the added α-alumina powder is also cyclically nitrided by the carbon source material and nitrogen to produce AlN powder.
It is desirable that the particle size is smaller than that of AlN powder, and α
- By selecting the average particle size of the alumina powder, it is necessary to produce AlN powder with a narrow particle size distribution. In addition, in the present invention, since abnormal grain growth does not occur during the phase transition from α-alumina precursor to α-alumina, a large number of carbon source substances are not trapped within α-alumina grains, and oxidative desorption occurs. It becomes easier to remove carbon by oxidation in the charcoal process,
Residual carbon in AlN powder products can be reduced [Example] Example 1 A mixture for producing AlN powder was prepared using the formulations shown in Table 1, and the mixture was heated at 1600°C for 50 minutes in a nitrogen atmosphere.
After firing for an hour, decarburization treatment was performed at 650℃ for 3 hours.
AlN powder was obtained. Aluminum hydroxide Al(OH) 3 was used as the α-alumina precursor. In Table 1,
, , are examples that meet the manufacturing conditions of the present invention, and , , are comparative examples. All of these mixtures were prepared using the following procedure. An α-alumina precursor dispersed in water with a concentration of 20% by weight and a dispersion with a carbon concentration of 15% by weight obtained by adding a dispersant and water to solid carbon powder and kneading the mixture in a pot mill for 10 hours were prepared in advance. After mixing both of them so that the weight ratio of carbon and α-alumina precursor is 1, they are dispersed in water,
α-alumina powder with a concentration of 10% by weight (average particle size
A predetermined amount of 0.3 μm) was added and mixed, water was removed by heating, the mixture was gelatinized, and then dried. The above AlN powder production test was conducted five times under each condition. The average value of the particle size distribution of the above nine types of AlN powders is shown in FIG. The following things were confirmed from FIG. 1 and observation using a scanning electron microscope. In Comparative Examples, the particle size distribution was wide, and not only was the average particle size large, but some particles were found to have abnormally grown to 5 μm or more. Example, Comparative example,
Compared to , the particle size is smaller and the particle size distribution is narrower.
No abnormally grown grains were observed, and the variation in grain size among the five tests was small. Example 2 Aluminum chloride as α-alumina precursor
Using AlCl 3 , with the composition shown in Table 1
A mixture for producing AlN powder was prepared, fired at 1600°C for 5 hours in a nitrogen atmosphere, and then decarburized at 650°C for 3 hours to obtain AlN powder. In Table 1,
, , are examples that meet the manufacturing conditions of the present invention, and , , are comparative examples. Using these mixtures, AlN powder was produced using the same procedure as in Example 1. The above AlN powder production test was conducted five times under each condition. The average value of the particle size distribution of the above nine types of AlN powders is shown in FIG. The following was confirmed from FIG. 2 and observation using a scanning electron microscope. In Comparative Examples, the particle size distribution was wide, and not only was the average particle size large, but some particles were found to have abnormally grown to 5 μm or more. Example, Comparative example,
Compared to , the particle size is smaller and the particle size distribution is narrower.
No abnormally grown grains were observed, and the variation in grain size among the five tests was small.
本発明によつて、微細で、均一粒径のAlN粉
末を極めて再現性よく製造することが可能になつ
た。
このAlN粉末を用いることにより、高密度で、
高熱伝導性、高強度のAlN焼結体を製造するこ
とが容易となり、高温構造材料、IC（集積回路）
基板等への利用に貢献するところが大である。
The present invention has made it possible to produce fine AlN powder with uniform particle size with extremely high reproducibility. By using this AlN powder, high density,
It is now easy to produce high thermal conductivity and high strength AlN sintered bodies, which can be used as high-temperature structural materials and IC (integrated circuits).
This greatly contributes to its use in substrates, etc.
第１図はα−アルミナ前駆体として水酸化アル
ミニウムを用いて種々の方法で作製したAlN粉
末の粒度分布を示すグラフ、第２図はα−アルミ
ナ前駆体として塩化アルミニウムを用いて種々の
方法で作製したAlN粉末の粒度分布を示すグラ
フである。
Figure 1 is a graph showing the particle size distribution of AlN powder prepared by various methods using aluminum hydroxide as an α-alumina precursor, and Figure 2 is a graph showing the particle size distribution of AlN powder prepared by various methods using aluminum chloride as an α-alumina precursor. It is a graph showing the particle size distribution of the produced AlN powder.
Claims (1)
アルミナ及びγ−アルミナから選択された、加熱
によつてα−アルミナに変化するα−アルミナ前
駆体と炭素源物質とを混合し、乾燥した後、窒素
を含む非酸化性雰囲気中で焼成する窒化アルミニ
ウム粉末の製造方法において、該α−アルミナ前
駆体と該炭素源物質との混合物に平均粒径2μm以
下のα−アルミナ粉末を、該α−アルミナ前駆体
のα−アルミナ換算量に対して0.01〜50重量％添
加することを特徴とする窒化アルミニウム粉末の
製造方法。 ２ 前記α−アルミナ前駆体とα−アルミナ粉末
をあらかじめ均一に混合した後、炭素源物質と混
合することを特徴とする請求項１記載の窒化アル
ミニウム粉末の製造方法。[Claims] 1. Aluminum salt, aluminum hydroxide, θ-
Nitriding is performed by mixing an α-alumina precursor selected from alumina and γ-alumina that changes into α-alumina by heating with a carbon source material, drying the mixture, and then firing it in a non-oxidizing atmosphere containing nitrogen. In the method for producing aluminum powder, α-alumina powder with an average particle size of 2 μm or less is added to the mixture of the α-alumina precursor and the carbon source material, and the α-alumina precursor is added at a rate of 0.01 to the α-alumina equivalent amount of the α-alumina precursor. A method for producing aluminum nitride powder, characterized by adding ~50% by weight. 2. The method for producing aluminum nitride powder according to claim 1, wherein the α-alumina precursor and α-alumina powder are uniformly mixed in advance and then mixed with a carbon source material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19880088A JPH0248408A (en) | 1988-08-11 | 1988-08-11 | Production of aluminum nitride powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19880088A JPH0248408A (en) | 1988-08-11 | 1988-08-11 | Production of aluminum nitride powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0248408A JPH0248408A (en) | 1990-02-19 |
| JPH0535682B2 true JPH0535682B2 (en) | 1993-05-27 |
Family
ID=16397122
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19880088A Granted JPH0248408A (en) | 1988-08-11 | 1988-08-11 | Production of aluminum nitride powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0248408A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPWO2021161883A1 (en) * | 2020-02-10 | 2021-08-19 |
-
1988
- 1988-08-11 JP JP19880088A patent/JPH0248408A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0248408A (en) | 1990-02-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4780299A (en) | Method for producing aluminum nitride powder | |
| EP3502052B1 (en) | Method for preparing spherical aluminum nitride powder | |
| CN112110424B (en) | Preparation method of superfine aluminum nitride powder | |
| CN111825452B (en) | Low-thermal-conductivity high-entropy aluminate ceramic and preparation method thereof | |
| JPS61151006A (en) | Production of aluminum nitride powder | |
| JP3636370B2 (en) | Aluminum nitride powder and method for producing the same | |
| JPH0535682B2 (en) | ||
| JPH0323206A (en) | Aluminum nitride powder and its production | |
| JPH01122964A (en) | Zirconia stabilized by yttrium and its production | |
| JP7361633B2 (en) | aluminum nitride particles | |
| JPS63139008A (en) | Production of powdery aluminum nitride | |
| KR900000036B1 (en) | Method for sintering ceramic-body | |
| JPH0466806B2 (en) | ||
| JPS61155210A (en) | Preparation of easily sinterable aluminum nitride powder | |
| JP2577378B2 (en) | Manufacturing method of aluminum nitride sintered body | |
| CA1270365A (en) | Method for producing aluminum nitride powder | |
| JPS5918106A (en) | Preparation of silicon aluminum oxynitride type powdery raw material | |
| JPH0465003B2 (en) | ||
| KR102510280B1 (en) | High Purity and High Density Yttrium Aluminum Garnet Sintered Body And Manufacturing Method Thereof | |
| JPH02160610A (en) | Production of aluminum nitride powder | |
| JPS62167208A (en) | Production of aluminum nitride powder | |
| JPS62246812A (en) | Production of aluminum nitride powder | |
| JPH0459609A (en) | Production of aluminum nitride powder | |
| JPS61155209A (en) | Preparation of easily sinterable aluminum nitride powder | |
| JPH03279263A (en) | Production of aluminum nitride powder |