JP7645676B2 - Aluminum nitride sintered granules - Google Patents
Aluminum nitride sintered granules Download PDFInfo
- Publication number
- JP7645676B2 JP7645676B2 JP2021049076A JP2021049076A JP7645676B2 JP 7645676 B2 JP7645676 B2 JP 7645676B2 JP 2021049076 A JP2021049076 A JP 2021049076A JP 2021049076 A JP2021049076 A JP 2021049076A JP 7645676 B2 JP7645676 B2 JP 7645676B2
- Authority
- JP
- Japan
- Prior art keywords
- aluminum nitride
- powder
- granules
- particles
- specific
- 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.)
- Active
Links
Landscapes
- Ceramic Products (AREA)
Description
本発明は、新規な窒化アルミニウム焼結顆粒に関する。詳しくは、樹脂やグリース、接着剤、塗料等に充填して放熱性を向上させるための放熱材料用フィラーとして有用な窒化アルミニウム焼結顆粒に関するものである。 The present invention relates to novel sintered aluminum nitride granules. More specifically, the present invention relates to sintered aluminum nitride granules that are useful as a filler for heat dissipation materials to be filled into resins, greases, adhesives, paints, etc. to improve heat dissipation.
近年、電子部品の高集積化・高密度化が進み、放熱材料に対する要求性能が高まっている。窒化アルミニウムは電気絶縁性に優れ、かつ高熱伝導性を有することから、その粉末をフィラーとして充填した樹脂シートやグリース、接着剤、塗料等は、高熱伝導性、高電気絶縁性を有する放熱材料として期待される。 In recent years, electronic components have become increasingly highly integrated and dense, raising the demands on heat dissipation materials. Aluminum nitride has excellent electrical insulation and high thermal conductivity, so resin sheets, greases, adhesives, paints, etc. that contain aluminum nitride powder as a filler are expected to serve as heat dissipation materials with high thermal conductivity and electrical insulation.
上記放熱材料の熱伝導率を向上させるためには、高熱伝導率のフィラーを用いることに加え、放熱材料中で熱伝導経路を多く形成させることが重要である。一般にはフィラーを高充填し、フィラー粒子間の接触頻度を高めることにより熱伝導経路を増加させる。そのため、充填性に優れた窒化アルミニウム粉末が強く要望されている。このような粉末として、窒化アルミニウム粉末を顆粒状に成形した後に焼結した、焼結顆粒が知られている（例えば、特許文献１、２、３参照）。焼結顆粒は球形度が高く、平滑な表面を有するため、充填性に優れ、放熱材料に高熱伝導性を付与できる。 In order to improve the thermal conductivity of the above-mentioned heat dissipation material, it is important to use a filler with high thermal conductivity and to form many heat conduction paths in the heat dissipation material. In general, the heat conduction paths are increased by highly filling the filler and increasing the frequency of contact between the filler particles. For this reason, there is a strong demand for aluminum nitride powder with excellent filling properties. As such a powder, sintered granules are known, which are formed by molding aluminum nitride powder into granules and then sintering them (see, for example, Patent Documents 1, 2, and 3). Sintered granules have high sphericity and a smooth surface, so they have excellent filling properties and can impart high thermal conductivity to the heat dissipation material.
しかしながら、従来の窒化アルミニウム焼結顆粒は球状であるため、不定形状粒子からなる粉末等と比較した場合、充填性に優れる一方で粒子間の接触面積が小さく、充填率向上による熱伝導経路の形成効率が低いことが課題であった。 However, because conventional sintered aluminum nitride granules are spherical, they have excellent packing properties compared to powders and other materials made up of irregularly shaped particles, but the contact area between particles is small, which poses an issue of low efficiency in forming heat conduction paths when the packing rate is increased.
本発明者らは、上記課題を解決すべく鋭意研究を行った結果、窒化アルミニウム焼結顆粒の粒子表面に、熱伝導性が高い無機物よりなり、且つ、特定の高さを有する凸部を特定の頻度で形成せしめることにより、焼結顆粒の特長である高充填性を維持したまま、粒子間の接触面積を拡大でき、これを樹脂に充填することで、得られる放熱材料に高い熱伝導性を付与できることを見出し、本発明を提案するに至った。 The inventors conducted extensive research to solve the above problems, and discovered that by forming protrusions of a specific height made of a highly thermally conductive inorganic material on the particle surfaces of aluminum nitride sintered granules at a specific frequency, it is possible to increase the contact area between particles while maintaining the high packing properties that are a characteristic of sintered granules, and by filling this with resin, it is possible to impart high thermal conductivity to the resulting heat dissipation material, which led to the proposal of the present invention.
即ち、本発明によれば、球形度が０．８０以上、粒子径が２０～１５０μｍの範囲にある窒化アルミニウム焼結顆粒であって、高さが３～１０μｍの範囲にあり、且つ、理論熱伝導率が４０Ｗ／ｍ・Ｋ以上の無機物よりなる凸部を２．０×１０－３個／μｍ２以上の頻度で表面に有することを特徴とする窒化アルミニウム焼結顆粒（以下、特定窒化アルミニウム焼結顆粒ともいう）が提供される。 That is, according to the present invention, there is provided aluminum nitride sintered granules having a sphericity of 0.80 or more and a particle size in the range of 20 to 150 μm, characterized in that the aluminum nitride sintered granules have a height in the range of 3 to 10 μm and have protrusions made of an inorganic substance having a theoretical thermal conductivity of 40 W/m·K or more on their surface at a frequency of 2.0× 10-3 / μm2 or more (hereinafter, also referred to as specific aluminum nitride sintered granules).
また、本発明によれば、特定窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末よりなる樹脂用フィラーが提供される。 The present invention also provides a filler for resins made of aluminum nitride powder containing specific aluminum nitride sintered granules.
更に、本発明によれば、前記樹脂用フィラーを６０容量％以上の充填率で充填することにより、極めて高い熱伝導率を実現可能な樹脂組成物をも提供する。 Furthermore, the present invention also provides a resin composition that can achieve extremely high thermal conductivity by filling the resin filler at a filling rate of 60 volume % or more.
本発明の特定窒化アルミニウム顆粒は、焼結顆粒の球形度は維持したまま、表面に凸部を形成した形状を成しているため、樹脂中に高充填でき、かつ粒子間の接触面積が大きい粒子であり、単独で、或いは、他の窒化アルミニウム粒子と組み合わせて構成される窒化アルミニウム粉末は、樹脂に充填して得られる樹脂組成物に高い熱伝導性を付与できる。 The specific aluminum nitride granules of the present invention have a shape with convex portions formed on the surface while maintaining the sphericity of sintered granules, so they can be highly filled into resin and have a large contact area between particles. Aluminum nitride powder, either alone or in combination with other aluminum nitride particles, can impart high thermal conductivity to the resin composition obtained by filling it into resin.
以下、本発明の実施形態について詳細に説明する。 The following describes an embodiment of the present invention in detail.
本発明の特定窒化アルミニウム焼結顆粒は、球形度が０．８０以上、粒子径が２０～１５０μｍの範囲にある窒化アルミニウム焼結顆粒であって、理論熱伝導率が４０Ｗ／ｍ・Ｋ以上の無機物よりなり、高さが３～１０μｍの範囲にある凸部を２．０×１０－３個／μｍ２以上の頻度で表面に有することを特徴とする。 The specific aluminum nitride sintered granules of the present invention are characterized in that they have a sphericity of 0.80 or more and a particle size in the range of 20 to 150 μm, are made of an inorganic substance with a theoretical thermal conductivity of 40 W/m·K or more, and have convex portions with heights in the range of 3 to 10 μm on their surface at a frequency of 2.0× 10-3 /μm2 or more .
尚、本発明において、原則的には、「顆粒」、「粒子」は、粒子単体を、また、「粉末」は、粒子単体の集合体を言う。 In principle, in the present invention, "granules" and "particles" refer to individual particles, and "powder" refers to an aggregate of individual particles.
〔球形度〕
本発明の特定窒化アルミニウム焼結顆粒の球形度は０．８０以上、好ましくは０．８５以上、さらに好ましくは０．９０以上である。球形度が０．８０未満であると、樹脂への高充填化が困難となる。球形度は粒子の短径／粒子の長径により求められ、１に近くなるほど球に近くなり、樹脂やグリースに高充填し易くなる。
[Sphericity]
The sphericity of the specific aluminum nitride sintered granules of the present invention is 0.80 or more, preferably 0.85 or more, and more preferably 0.90 or more. If the sphericity is less than 0.80, it is difficult to highly fill the resin. The sphericity is calculated by dividing the minor axis of the particle by the major axis of the particle, and the closer it is to 1, the closer it is to a sphere, and the easier it is to highly fill resin or grease.
尚、後述するように、本発明の特定窒化アルミニウム焼結顆粒は、略球状の形状を主とする焼結顆粒に凸部が形成されるため、得られる窒化アルミニウム焼結顆粒は、殆ど前記球形度を有するものとなる。 As described below, the specific sintered aluminum nitride granules of the present invention are sintered granules that are primarily spherical in shape, and thus have convex portions formed thereon, so that the resulting sintered aluminum nitride granules have almost the above-mentioned sphericity.
〔粒子径〕
本発明の特定窒化アルミニウム焼結顆粒の粒子径は、２０～１５０μｍ、好ましくは２５～１００μｍの範囲にある。この範囲にあるものが樹脂に充填した際の凸部による粒子間の接触が効果的に行われ、また、他の粒子との併用による高充填化がし易い。
[Particle size]
The particle size of the specific aluminum nitride sintered granules of the present invention is in the range of 20 to 150 μm, preferably 25 to 100 μm. When the particles are filled into a resin, the contact between the particles is effectively achieved by the protrusions, and the particles can be easily packed in high density by using the particles in combination with other particles.
〔表面の凸部〕
本発明の特定窒化アルミニウム焼結顆粒の表面凸部の高さは、３～１０μｍ、好ましくは４～９μｍである。凸部の高さがこの範囲より小さいと、樹脂組成物に充填した粒子間の接触面積が小さくなり、高熱伝導率を付与できない。また、１０μｍを超える凸部は形成が困難であるばかりでなく、かかる凸部が存在する場合、粒子間の立体的な障害が大きくなり充填性が低下することが懸念される。
[Convex parts on the surface]
The height of the surface projections of the specific aluminum nitride sintered granules of the present invention is 3 to 10 μm, preferably 4 to 9 μm. If the height of the projections is smaller than this range, the contact area between the particles filled in the resin composition becomes small, and high thermal conductivity cannot be imparted. In addition, not only is it difficult to form projections exceeding 10 μm, but if such projections exist, there is a concern that the three-dimensional obstacles between the particles will become large and the filling property will be reduced.
尚、凸部の測定方法は後述するが、かかる測定方法における研磨の位置によっては、凸部の最高部の高さが観察されない場合もある。しかし、測定位置での高さが３μｍを超えていれば、凸部の最高部の高さ（凸部の頂部）はそれ以上の高さである。 The method for measuring the convex portion will be described later, but depending on the polishing position in this measurement method, the height of the highest part of the convex portion may not be observed. However, if the height at the measurement position exceeds 3 μm, the height of the highest part of the convex portion (the top of the convex portion) is higher than that.
本発明の特定窒化アルミニウム焼結顆粒において、前記凸部の個数は２．０×１０－３個／μｍ２以上、好ましくは３．０×１０－３～１．０×１０－２個、更に好ましくは３．５×１０－３～９．５×１０－３個である。表面凸部の個数がこの範囲より少ないと、凸部による接触面積の増加効果が十分でなく、樹脂組成物に充填した粒子間の接触面積が小さくなり、高熱伝導率を付与できない。凸部の個数がこの範囲より多いと、粒子の比表面積が高く、樹脂配合時に高粘度化するため、粉末の充填性が低下する傾向がある。 In the specific aluminum nitride sintered granules of the present invention, the number of the protrusions is 2.0×10 −3 /μm 2 or more, preferably 3.0×10 −3 to 1.0×10 −2 , and more preferably 3.5×10 −3 to 9.5×10 −3 . If the number of surface protrusions is less than this range, the effect of increasing the contact area by the protrusions is insufficient, the contact area between the particles filled in the resin composition becomes small, and high thermal conductivity cannot be imparted. If the number of protrusions is more than this range, the specific surface area of the particles is high, and the viscosity increases during resin compounding, so that the powder filling property tends to decrease.
本発明の粒子表面凸部を形成する物質としては、理論熱伝導率が４０Ｗ／ｍ・Ｋ以上、好ましくは、１００Ｗ／ｍ・Ｋ以上の無機物が特に限定されることなく使用される。上記無機物としては、例えば、窒化アルミニウム、窒化ケイ素、炭化ケイ素、酸化アルミニウム、酸化マグネシウム、酸化亜鉛などの熱伝導率が高く、凸部を形成し易い非扁平な形状を有するものが好適である。そのうち、熱伝導率が高い、窒化ケイ素、窒化アルミニウムが、特に窒化アルミニウムが好適である。 As the material for forming the protrusions on the particle surface of the present invention, any inorganic material with a theoretical thermal conductivity of 40 W/m·K or more, preferably 100 W/m·K or more, is used without any particular limitation. As the above-mentioned inorganic material, for example, aluminum nitride, silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, zinc oxide, and other materials with high thermal conductivity and non-flat shape that makes it easy to form protrusions are suitable. Among these, silicon nitride and aluminum nitride, which have high thermal conductivity, are particularly suitable, with aluminum nitride being particularly preferred.
本発明の特定窒化アルミニウム焼結顆粒は、後述する製造方法によって、特定窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末として得られる。かかる窒化アルミニウム粉末は、僅かに存在する小粒径の粒子を除く殆どの粒子、具体的には、９０容量％以上、特に、９５容量％以上が特定窒化アルミニウム焼結顆粒として存在する。 The specific aluminum nitride sintered granules of the present invention are obtained as aluminum nitride powder containing specific aluminum nitride sintered granules by the manufacturing method described below. Most of the particles of this aluminum nitride powder, excluding a small number of small particles, specifically 90% by volume or more, and particularly 95% by volume or more, are present as specific aluminum nitride sintered granules.
本発明の特定窒化アルミニウム焼結顆粒は、製造により得られた窒化アルミニウム粉末の状態で使用することもできるが、これに、粒径の異なる特定窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末、粒径が同じか異なる、粒子表面凸部を持たない窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末、粒径が異なり、窒化アルミニウム焼結顆粒を含まない窒化アルミニウム粉末などを適宜組み合わせて混合した窒化アルミニウム粉末として使用することができる。 The specific aluminum nitride sintered granules of the present invention can be used in the form of aluminum nitride powder obtained by production, but can also be used as aluminum nitride powder obtained by appropriately combining and mixing aluminum nitride powders containing specific aluminum nitride sintered granules of different particle sizes, aluminum nitride powders containing aluminum nitride sintered granules of the same or different particle sizes that do not have protrusions on the particle surface, aluminum nitride powders of different particle sizes that do not contain aluminum nitride sintered granules, etc.
特に、樹脂フィラーとして本発明の窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末を使用する場合は、樹脂への充填率を上げるため、径の異なるものを混合した窒化アルミニウム粉末として使用することが好ましい。径の異なる窒化アルミニウム粉末として、例えば、サブミクロン～数ミクロンの大きさの窒化アルミニウム粉末は樹脂への充填率を上げるために好適に使用される。 In particular, when using aluminum nitride powder containing the aluminum nitride sintered granules of the present invention as a resin filler, it is preferable to use aluminum nitride powder with a mixture of particles of different diameters in order to increase the filling rate in the resin. As aluminum nitride powder with different diameters, for example, aluminum nitride powder with a size of submicrons to several microns is preferably used in order to increase the filling rate in the resin.
上述した組合せにより調製される窒化アルミニウム粉末において、本発明の特定窒化アルミニウム焼結顆粒の割合が５０容量％以上、好ましくは、６０容量％以上の割合となるように混合比率を調整することが、特定窒化アルミニウム焼結顆粒の機能を十分発揮させるために好ましい。 In the aluminum nitride powder prepared by the above combination, it is preferable to adjust the mixing ratio so that the proportion of the specific aluminum nitride sintered granules of the present invention is 50% by volume or more, preferably 60% by volume or more, in order to fully exert the functions of the specific aluminum nitride sintered granules.
［窒化アルミニウム焼結顆粒の製造方法］
本発明の窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末の製造方法は、特に限定されるものではないが、例えば、本発明の窒化アルミニウム焼結顆粒を高含有率で再現性良く製造するための方法として、窒化アルミニウム粉末を２０～２００μｍ程度の顆粒状に成形した顆粒状成形体と、凸部を形成せしめるための、平均粒径が３～１０μｍであり、理論熱伝導率が４０Ｗ／ｍ・Ｋ以上の無機粉末とよりなる混合粉を、空気雰囲気下で脱脂した後に、窒素雰囲気下で焼結する方法が挙げられる。
[Method of manufacturing sintered aluminum nitride granules]
The method for producing aluminum nitride powder containing the aluminum nitride sintered granules of the present invention is not particularly limited, but an example of a method for producing the aluminum nitride sintered granules of the present invention at a high content with good reproducibility is a method in which a mixed powder consisting of a granular compact obtained by molding aluminum nitride powder into granules of about 20 to 200 μm and an inorganic powder having an average particle size of 3 to 10 μm and a theoretical thermal conductivity of 40 W/m K or more, for forming convex portions, is degreased in an air atmosphere and then sintered in a nitrogen atmosphere.
上記製造方法により、殆どの粒子が窒化アルミニウム焼結顆粒より構成される窒化アルミニウム粉末が得られる。 The above manufacturing method produces aluminum nitride powder in which most of the particles are composed of sintered aluminum nitride granules.
以下に詳細に説明する。 Details are explained below.
・窒化アルミニウム顆粒状成形体
本発明の窒化アルミニウム粉末の原料となる窒化アルミニウム顆粒状成形体は、平均球形度０．８以上を有し、１８５０℃以下の焼成により焼結し、緻密体が得られるものがすべて使用可能である。製造方法は特に限定されるものではないが、例えば、窒化アルミニウム粉末、焼結助剤粉末、バインダー、分散剤及び溶媒の混合物を混合してスラリーを調整し、次いで、上記スラリーをスプレードライ乾燥することにより製造することができる。
-Aluminum nitride granular molded body The aluminum nitride granular molded body that is the raw material for the aluminum nitride powder of the present invention can be any aluminum nitride granular molded body that has an average sphericity of 0.8 or more and can be sintered to obtain a dense body by firing at 1850° C. or less. The production method is not particularly limited, but it can be produced, for example, by mixing a mixture of aluminum nitride powder, sintering aid powder, binder, dispersant and solvent to prepare a slurry, and then spray-drying the slurry.
上記製造方法において、原料の窒化アルミニウム粉末は、特に限定されないが、平均一次粒子径が０．４～１．２μｍのものを使用することが好ましい。平均一次粒子径がこの範囲より小さいと、スラリー中で窒化アルミニウム粉末が凝集しやすく、顆粒構造の偏りが発生する。平均一次粒子径がこの範囲より大きいと、焼結しにくくなり、焼結後の顆粒に焼結不足による空隙が残存する。空隙が残存すると樹脂充填時に増粘して高充填出来ない。 In the above manufacturing method, the aluminum nitride powder used as the raw material is not particularly limited, but it is preferable to use one with an average primary particle size of 0.4 to 1.2 μm. If the average primary particle size is smaller than this range, the aluminum nitride powder is likely to aggregate in the slurry, causing deviations in the granular structure. If the average primary particle size is larger than this range, sintering becomes difficult, and voids remain in the granules after sintering due to insufficient sintering. If voids remain, the resin will thicken when filled, making it impossible to fill it highly.
前記製造方法において、焼結助剤は特に限定されないが、希土類金属酸化物を使用することが好ましい。かかる希土類酸化物については特に限定されないが、熱伝導率の観点からイットリウム化合物、特には酸化イットリウムを使用することが好ましい。また、焼結助剤の添加量は熱伝導率、及び焼結促進効果の観点から、窒化アルミニウムに対して２～６重量部であることが好ましい。添加量がこの範囲より少ないと焼結が進みにくく、焼結後の顆粒に焼結不足による空隙が残存する。添加量がこの範囲より多いと焼結時に窒化アルミニウムの純化が起こりにくく、焼結顆粒の熱伝導率が低下する。また、焼結助剤により顆粒間の焼結が起きやすくなり、凝集粉末が増加する。 In the above manufacturing method, the sintering aid is not particularly limited, but it is preferable to use a rare earth metal oxide. The rare earth oxide is not particularly limited, but it is preferable to use an yttrium compound, especially yttrium oxide, from the viewpoint of thermal conductivity. In addition, the amount of sintering aid added is preferably 2 to 6 parts by weight based on the aluminum nitride from the viewpoint of thermal conductivity and sintering promotion effect. If the amount added is less than this range, sintering does not proceed easily, and voids due to insufficient sintering remain in the granules after sintering. If the amount added is more than this range, purification of the aluminum nitride during sintering does not occur easily, and the thermal conductivity of the sintered granules decreases. In addition, the sintering aid makes it easier for granules to sinter, and the amount of agglomerated powder increases.
前記製造方法において、溶媒は公知のものを特に制限なく使用できるが、例えば、アセトン、ケトン類、エタノール、プロパノール等のアルコール類、ベンゼン、トルエン等の芳香族炭化水素類等が好適に使用される。 In the above-mentioned manufacturing method, any known solvent can be used without particular limitation, but for example, acetone, ketones, alcohols such as ethanol and propanol, and aromatic hydrocarbons such as benzene and toluene are preferably used.
・凸部形成用粉末
本発明の窒化アルミニウム粒子の表面凸部を形成するための凸部形成用粉末は、理論熱伝導率が４０Ｗ／ｍ・Ｋ以上、好ましくは１００Ｗ／ｍ・Ｋ以上の無機物の粉末であり、前記例示した無機物の粉末が好適に使用される。尚、物質によっては窒化アルミニウムと異物質間で焼結しにくいことがあるが、その場合も窒化アルミニウム顆粒が含有する焼結助剤を介して顆粒表面に結合される。
Powder for forming convex portions The powder for forming convex portions on the surface of the aluminum nitride particles of the present invention is an inorganic powder having a theoretical thermal conductivity of 40 W/m·K or more, preferably 100 W/m·K or more, and the inorganic powders exemplified above are preferably used. Note that, depending on the substance, it may be difficult to sinter aluminum nitride with a different substance, but even in that case, the aluminum nitride granules will bond to the granule surface via the sintering aid contained in the aluminum nitride granules.
凸部形成用粉末の粒子径は３～１０μｍのものが利用できる。粒子径がこの範囲より小さいと、焼結時に顆粒と一体化してしまい、十分な高さの凸部を形成し難く、粒子径がこの範囲より大きいと、凸部による粒子間の立体的な障害が大きくなり、粉末の充填性が低下する。また、凸部形成用粉末を構成する粒子は凝集しておらず、一次粒子として３～１０μｍであることが好ましい。凝集粉であると焼結後に凸部内に空孔が残存し、凸部の強度が低下したり、樹脂充填時に増粘したりする傾向がある。 The particle size of the powder for forming the protrusions can be 3 to 10 μm. If the particle size is smaller than this range, it will be integrated with the granules during sintering, making it difficult to form protrusions of sufficient height, and if the particle size is larger than this range, the protrusions will cause large three-dimensional obstacles between the particles, reducing the powder's packing ability. In addition, it is preferable that the particles that make up the powder for forming the protrusions are not agglomerated, and that the primary particles are 3 to 10 μm. If the powder is agglomerated, voids will remain in the protrusions after sintering, reducing the strength of the protrusions and causing the resin to thicken when filled.
・原料混合
本発明の製造方法において、混合方法は窒化アルミニウム顆粒の形状が崩壊せず、窒化アルミニウム顆粒と凸部形成用粉末が均一に混合できるものがすべて使用できる。混合装置は特に限定されないが、例えばＶ字混合機、Ｗ型混合機、ドラム型混合機等が利用できる。
In the manufacturing method of the present invention, any mixing method can be used that does not destroy the shape of the aluminum nitride granules and can uniformly mix the aluminum nitride granules and the powder for forming the convex portions. There are no particular limitations on the mixing device, but for example, a V-shaped mixer, a W-shaped mixer, a drum-type mixer, etc. can be used.
窒化アルミニウム顆粒と凸部形成用粉末の混合比は窒化アルミニウム顆粒１００重量部に対して、凸部形成用粉末を５～３０重量部添加することが好ましい。添加量がこの範囲より少ないと、焼結後粒子表面に形成される凸部が少なくなり、樹脂組成物に充填した粒子間の接触面積が小さく、高熱伝導率を付与できない。添加量がこの範囲より多いと、添加量がこの範囲より多いと、焼結後粒子表面に形成される凸部が多くなり、樹脂配合時に高粘度化するため、粉末の充填性が低下する。 The preferred mixing ratio of aluminum nitride granules and powder for forming convex portions is 5 to 30 parts by weight of powder for forming convex portions to 100 parts by weight of aluminum nitride granules. If the amount added is less than this range, fewer convex portions will be formed on the particle surfaces after sintering, the contact area between the particles filled in the resin composition will be small, and high thermal conductivity will not be achieved. If the amount added is more than this range, more convex portions will be formed on the particle surfaces after sintering, and the viscosity will increase when the resin is mixed, reducing the filling ability of the powder.
・焼結
上記混合粉末を空気雰囲気下で焼成し、バインダー及び分散剤を除去した後に、窒素雰囲気下、１７００℃～１８５０℃の温度範囲で、１～１０時間焼結することで、本発明の窒化アルミニウム粒子を得ることができる。上記焼成温度が範囲より低いと窒化アルミニウム顆粒部分の緻密化及び、顆粒部分への凸部形成用粉末の焼結が不十分になる傾向がある。焼成温度が範囲より高いと窒化アルミニウム顆粒表面に凸部形成用粉末が焼結するだけでなく、窒化アルミニウム顆粒間が焼結した粒子が生成する傾向がある。
上記焼成後、表面に凸部を有する窒化アルミニウム粒子間でわずかに融着が発生する。融着があると樹脂への充填性が低下するため、軽度な解砕処理をして融着を除去する。解砕方法は特に限定されないが、回転ミル、ジェットミル、振動ミル等が利用できる。解砕処理により表面凸部を形成していた粒子が一部脱落する場合は、篩分け、気流分級等により除去できる。
Sintering The above mixed powder is sintered in an air atmosphere to remove the binder and dispersant, and then sintered in a nitrogen atmosphere at a temperature range of 1700°C to 1850°C for 1 to 10 hours to obtain the aluminum nitride particles of the present invention. If the sintering temperature is lower than the above range, the densification of the aluminum nitride granule portion and the sintering of the powder for forming the convex portions to the granule portion tend to be insufficient. If the sintering temperature is higher than the above range, not only the powder for forming the convex portions is sintered to the surface of the aluminum nitride granules, but also particles in which the aluminum nitride granules are sintered between each other tend to be generated.
After the above-mentioned firing, slight fusion occurs between the aluminum nitride particles having the protrusions on the surface. If fusion occurs, the filling ability into the resin decreases, so the fusion is removed by a light crushing treatment. The crushing method is not particularly limited, but a rotary mill, a jet mill, a vibration mill, etc. can be used. If some of the particles that formed the protrusions on the surface fall off due to the crushing treatment, they can be removed by sieving, air flow classification, etc.
〔用途〕
本発明の特定窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末は、窒化アルミニウムの性質を生かした種々の用途、特に放熱シート、放熱グリース、放熱接着剤、塗料、熱伝導性樹脂などの放熱材料用フィラーとして広く用いることができる。
[Application]
Aluminum nitride powder containing the specific aluminum nitride sintered granules of the present invention can be widely used in various applications that make use of the properties of aluminum nitride, particularly as a filler for heat-dissipating materials such as heat-dissipating sheets, heat-dissipating greases, heat-dissipating adhesives, paints, and thermally conductive resins.
ここで放熱材料のマトリックスとなる樹脂、グリースは、エポキシ樹脂、フェノール樹脂等の熱硬化性樹脂や、ポリエチレン、ポリプロピレン、ポリアミド、ポリカーボネート、ポリイミド、ポリフェニレンサルファイド等の熱可塑性樹脂、またシリコーンゴム、ＥＰＲ、ＳＢＲ等のゴム類、シリコーンオイルが挙げられる。 The resins and greases that serve as the matrix of the heat dissipation material include thermosetting resins such as epoxy resins and phenolic resins, thermoplastic resins such as polyethylene, polypropylene, polyamide, polycarbonate, polyimide, and polyphenylene sulfide, rubbers such as silicone rubber, EPR, and SBR, and silicone oil.
これらのうち、放熱材料のマトリックスとしては、例えばエポキシ系樹脂、シリコーン系樹脂が好適であり、高柔軟性放熱部材とするには付加反応型液状シリコーンゴムが望ましい。 Of these, epoxy resins and silicone resins are suitable as matrices for heat dissipation materials, and addition reaction type liquid silicone rubber is preferable for making highly flexible heat dissipation components.
放熱材料の熱伝導性を向上させるため、樹脂、ゴム又はオイルに対し６０容量％以上、好ましくは７０容量％以上、より好ましくは８０容量％以上充填するのが良い。このような放熱材料には、本発明の特定窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末以外に、アルミナ、酸化亜鉛、炭化珪素、グラファイトなどのフィラーを一種、あるいは数種類充填しても良く、放熱材料の特性や用途に応じて、フィラーの形状、粒径を選択すれば良い。それ以外のフィラーを配合する場合は本発明の窒化アルミニウム焼結顆粒の比率を５０容量％以上、好ましくは６０容量％以上にするのが良い。また、これらのフィラーは、例えばシランカップリング剤やリン酸又はリン酸塩などで表面処理したものを用いても良い。また、放熱材料には、可塑剤、加硫剤、硬化促進剤、離形剤等の添加剤をさらに添加しても良い。 In order to improve the thermal conductivity of the heat dissipation material, it is preferable to fill the resin, rubber, or oil with 60% by volume or more, preferably 70% by volume or more, and more preferably 80% by volume or more. In addition to the aluminum nitride powder containing the specific aluminum nitride sintered granules of the present invention, such a heat dissipation material may be filled with one or more types of fillers such as alumina, zinc oxide, silicon carbide, graphite, etc., and the shape and particle size of the filler may be selected according to the characteristics and use of the heat dissipation material. When other fillers are blended, the ratio of the aluminum nitride sintered granules of the present invention is preferably 50% by volume or more, preferably 60% by volume or more. In addition, these fillers may be surface-treated with, for example, a silane coupling agent, phosphoric acid, or phosphate. In addition, additives such as a plasticizer, a vulcanizing agent, a hardening accelerator, and a release agent may be further added to the heat dissipation material.
上記の樹脂組成物は、ブレンダーやミキサーで混合することによって製造することができ、また放熱材料は、プレス成形法、押出成形法、ドクターブレード法によって樹脂組成物を成形し、それを加熱硬化することによって製造することができる。 The above resin composition can be produced by mixing in a blender or mixer, and the heat dissipation material can be produced by molding the resin composition using press molding, extrusion molding, or doctor blade methods, and then heating and curing it.
以下、本発明を更に具体的に説明するが、本発明はこれらの実施例に限定されるものではない。実施例および比較例における各種物性は、下記の方法により測定した。 The present invention will be described in more detail below, but the present invention is not limited to these examples. Various physical properties in the examples and comparative examples were measured by the following methods.
（１）粒径、真球度、粒子表面凸部の高さ及び個数
試料の窒化アルミニウム粉末をエポキシ樹脂に充填し、該樹脂を金型に注型し、熱プレスにより硬化させ、厚さ５００μｍのシートを作製した。上記窒化アルミニウム粉末を充填したシートを５μｍ間隔で削り、それぞれ研削面において電子顕微鏡写真を撮影した。
(1) Particle size, sphericity, height and number of protrusions on particle surface The aluminum nitride powder sample was filled into epoxy resin, the resin was poured into a mold, and cured by hot pressing to prepare a sheet with a thickness of 500 μm. The sheet filled with the aluminum nitride powder was ground at 5 μm intervals, and an electron microscope photograph was taken of each ground surface.
上記研磨面の電子顕微鏡の写真像からの情報に基づき、スケールを用いて粒子像の長径（ＤＬ）と短径（ＤＳ）を測定し、その比（ＤＳ／ＤＬ）を真球度とした。また、上記長径の値を粒子の粒子径とした。 Based on information from the electron microscope photograph of the polished surface, the long diameter (DL) and short diameter (DS) of the particle image were measured using a scale, and the ratio (DS/DL) was taken as the sphericity. The long diameter value was taken as the particle size of the particle.
また、上記研磨面の電子顕微鏡の写真像からの情報に基づき、粒子の表面凸部の個数及び表面からの高さを求めた。また、上記凸部の高さ（ｈ）は図３に示すように、粒子の断面について倍率５０００倍の画像より観察される粒子の輪郭線において、凸部の両端に存在する谷部の最低点を結んだ直線から凸部の頂点までの垂直距離を凸部の高さとした。前記研磨面の電子顕微鏡の写真像からの情報に基づき、粒子毎に、凸部の高さが３～１０μｍの凸部の個数を粒子の表面積で除して表面凸部頻度（個／μｍ２）を算出した。また、凸部の平均高さも併せて算出した。 Based on the information from the electron microscope photograph of the polished surface, the number of surface convexities of the particles and their height from the surface were obtained. As shown in FIG. 3, the height (h) of the convexities was determined as the vertical distance from the straight line connecting the lowest points of the valleys present at both ends of the convexity to the apex of the convexity on the contour line of the particle observed from the image of the cross section of the particle at a magnification of 5000 times. Based on the information from the electron microscope photograph of the polished surface, the number of convexities with a height of 3 to 10 μm was divided by the surface area of the particle to calculate the frequency of surface convexities (pieces/μm 2 ) for each particle. The average height of the convexities was also calculated.
（２）窒化アルミニウム粉末中の特定窒化アルミニウム焼結粒子の割合
前記（１）の研磨面の電子顕微鏡の写真像からの任意の１００粒子の計測情報に基づき、球形度が０．８０以上、粒子径（ＤＬ）が２０～１５０μｍの範囲にあり、凸部の高さが３～１０μｍの範囲にある粒子の体積割合を求め、特定窒化アルミニウム焼結顆粒の割合（容量％）とした。
(2) Proportion of specific aluminum nitride sintered particles in aluminum nitride powder Based on the measurement information of 100 random particles from the electron microscope photograph of the polished surface in (1) above, the volume percentage of particles having a sphericity of 0.80 or more, a particle diameter (DL) in the range of 20 to 150 μm, and a convex height in the range of 3 to 10 μm was determined, and this was taken as the percentage (volume %) of the specific aluminum nitride sintered granules.
（３）窒化アルミニウム粉末の比表面積
窒化アルミニウム粉末の比表面積は、流動式表面積自動測定装置（島津製作所製 フローソーブ２３００形）を用いて窒素吸着によるＢＥＴ法により求めた。
(3) Specific Surface Area of Aluminum Nitride Powder The specific surface area of the aluminum nitride powder was determined by the BET method using nitrogen adsorption with a flow type automatic surface area measuring device (Shimadzu Corporation, Flowsorb 2300 model).
（４）窒化アルミニウム粉末の平均粒子径
窒化アルミニウム粉末の平均粒子径（Ｄ５０）は、試料をホモジナイザーにてピロリン酸ソーダ中に分散させ、レーザー回折粒度分布装置（日機装株式会社製ＭＩＣＲＯＴＲＡＣ ＭＴ３３００）にて測定した。
(4) Average Particle Diameter of Aluminum Nitride Powder The average particle diameter (D 50 ) of aluminum nitride powder was measured by dispersing a sample in sodium pyrophosphate using a homogenizer and using a laser diffraction particle size distribution analyzer (MICROTRAC MT3300 manufactured by Nikkiso Co., Ltd.).
（５）樹脂成形体の熱伝導率
試料のシート体について熱物性測定装置（京都電子工業株式会社製 ＴＰＳ２５００）を用いて、ホットディスク法により測定した。
(5) Thermal Conductivity of Resin Molded Article The thermal conductivity of a sample sheet was measured by a hot disk method using a thermal property measuring device (TPS2500 manufactured by Kyoto Electronics Manufacturing Co., Ltd.).
実施例１
平均粒子径１．０μｍの窒化アルミニウム粉末と酸化イットリウム粉末を１００：５の割合で混合し、さらに界面活性剤としてヘキサグリセリンモノオレート１．０重量部、結合剤としてメタクリル酸ブチル２．５重量部、トルエン溶媒１００重量部を投入して、十分にボールミル混合し、スラリーを得た。こうして得られたスラリーをスプレードライヤーで噴霧乾燥し、平均粒径４０．５μｍの窒化アルミニウム顆粒状成形体を得た。
Example 1
Aluminum nitride powder with an average particle size of 1.0 μm and yttrium oxide powder were mixed in a ratio of 100:5, and 1.0 part by weight of hexaglycerin monooleate as a surfactant, 2.5 parts by weight of butyl methacrylate as a binder, and 100 parts by weight of toluene solvent were added and thoroughly mixed in a ball mill to obtain a slurry. The slurry thus obtained was spray-dried with a spray dryer to obtain an aluminum nitride granular compact with an average particle size of 40.5 μm.
この窒化アルミニウム顆粒状成形体と凸部形成用粉末として平均粒子径４．６μｍの窒化アルミニウム（理論熱伝導率３２０Ｗ／ｍ・Ｋ）粉末を１００：１０の割合で混合した。該混合粉末を空気雰囲気下、６００℃の温度で５時間焼成し、顆粒中の有機物を除去した後、窒素雰囲気下、１７５０℃の温度で５時間焼成した。焼成後塊状になった窒化アルミニウム粒子を回転ボールミルで処理して粒子間の凝集を解き、特定窒化アルミニウム焼結顆粒（表では「特定ＡｌＮ顆粒」と示す。）を表１に示す割合で有する特定窒化アルミニウム粉末（表では「特定ＡｌＮ粉末」と示す。）を得た。 This aluminum nitride granular compact was mixed with aluminum nitride powder (theoretical thermal conductivity 320 W/m·K) having an average particle size of 4.6 μm as a powder for forming the protrusions in a ratio of 100:10. The mixed powder was fired in an air atmosphere at 600°C for 5 hours to remove organic matter in the granules, and then fired in a nitrogen atmosphere at 1750°C for 5 hours. The aluminum nitride particles that had become clumpy after firing were treated in a rotary ball mill to break up the agglomerations between the particles, and a specific aluminum nitride powder (referred to as "specific AlN powder" in the table) having specific aluminum nitride sintered granules (referred to as "specific AlN granules" in the table) in the ratio shown in Table 1 was obtained.
上記特定窒化アルミニウム粉末の比表面積、平均粒径、上記特定窒化アルミニウム粉末に含まれる特定窒化アルミニウム焼結顆粒のうち、平均粒径近傍の径を有する粒子について、真球度、表面凸部最高高さ、３～１０μｍの表面凸部頻度等の物性を測定した結果を表１に示す。 The specific surface area and average particle size of the specific aluminum nitride powder, and the physical properties of the specific aluminum nitride sintered granules contained in the specific aluminum nitride powder that have a diameter close to the average particle size, such as sphericity, maximum height of surface protrusions, and frequency of surface protrusions of 3 to 10 μm, were measured and are shown in Table 1.
また、前記特定窒化アルミニウム粉末とＤ５０が０．８μｍの市販の窒化アルミニウム粉末を８：２の容量比で混合した窒化アルミニウム混合粉末（特定窒化アルミニウム焼結顆粒の割合：７６容量％）を、シリコーン樹脂（ダウ・東レ株式会社製 ＣＹ５２－２７６Ａ，Ｂ）に充填量が８０容量％になるように配合した。シリコーン樹脂への配合は東洋精機製作所製ラボプラストミルを使用して１５分間混錬することにより行い、得られた樹脂組成物を金型に充填し、８０℃×１時間、１ｔｏｎの熱ブレスを行って厚み６ｍｍのシート体を得、熱伝導率を測定した。結果を表１に併せて示す。 In addition, the specific aluminum nitride powder and a commercially available aluminum nitride powder having a D50 of 0.8 μm were mixed in a volume ratio of 8:2 to obtain an aluminum nitride mixed powder (ratio of specific aluminum nitride sintered granules: 76% by volume) in a silicone resin (CY52-276A, B manufactured by Dow Toray Co., Ltd.) so that the filling amount was 80% by volume. The silicone resin was mixed by kneading for 15 minutes using a Labo Plastomill manufactured by Toyo Seiki Seisakusho, and the resulting resin composition was filled into a mold and subjected to a hot press of 80 ° C. x 1 hour and 1 ton to obtain a sheet body having a thickness of 6 mm, and the thermal conductivity was measured. The results are also shown in Table 1.
実施例２
原料として１０１．２μｍのＡｌＮ顆粒を用いた以外は実施例１と同様にして、特定窒化アルミニウム粉末を得た。図１は得られた特定窒化アルミニウム粉末の電子顕微鏡写真であるが、球形度が高く、表面に４μｍ程度の凹凸を持つ粒子であることがわかる。
Example 2
A specific aluminum nitride powder was obtained in the same manner as in Example 1, except that 101.2 μm AlN granules were used as the raw material. Figure 1 is an electron microscope photograph of the specific aluminum nitride powder obtained, and it can be seen that the particles have a high degree of sphericity and have irregularities of about 4 μm on the surface.
得られた特定窒化アルミニウム粉末の比表面積、平均粒径、上記特定窒化アルミニウム粉末に含まれる特定窒化アルミニウム焼結顆粒のうち、平均粒径近傍の径を有する粒子について、真球度、表面凸部最高高さ、３～１０μｍの表面凸部頻度等の物性を測定した結果を表１に示す。 The specific surface area and average particle size of the obtained specific aluminum nitride powder, and the physical properties of the specific aluminum nitride sintered granules contained in the specific aluminum nitride powder that have a diameter close to the average particle size, such as sphericity, maximum height of surface protrusions, and frequency of surface protrusions of 3 to 10 μm, were measured and the results are shown in Table 1.
上記特定窒化アルミニウム粉末と、実施例１で得られた特定窒化アルミニウム粉末、Ｄ５０が０．８μｍの市販の窒化アルミニウム粉末を１：１：１の容量比で混合した窒化アルミニウム混合粉末（特定窒化アルミニウム焼結顆粒の割合：６４容量％）を用いて、実施例１と同様にしてシート体を得、熱伝導率を測定した。結果を表１に併せて示す。 The specific aluminum nitride powder, the specific aluminum nitride powder obtained in Example 1, and a commercially available aluminum nitride powder with a D50 of 0.8 μm were mixed in a volume ratio of 1:1:1 to obtain an aluminum nitride mixed powder (ratio of specific aluminum nitride sintered granules: 64 volume %) in the same manner as in Example 1, and the thermal conductivity was measured. The results are also shown in Table 1.
実施例３
凸部形成用粉末として平均粒子径９．８μｍの窒化アルミニウム粉末を用いた以外は実施例１と同様にして窒化アルミニウム粉末を得た。得られた窒化アルミニウム粉末の比表面積、平均粒径、表面凸部高さ、表面凸部頻度の測定結果を表１に示す。さらに得られた特定窒化アルミニウム粉末を用い、実施例１と同様に窒化アルミニウム混合粉末を調製し、また、これを使用したシート体を得、熱伝導率を測定した。結果を表１に併せて示す。
Example 3
An aluminum nitride powder was obtained in the same manner as in Example 1, except that an aluminum nitride powder having an average particle diameter of 9.8 μm was used as the powder for forming the convex portion. The measurement results of the specific surface area, average particle diameter, surface convex portion height, and surface convex portion frequency of the obtained aluminum nitride powder are shown in Table 1. Furthermore, using the obtained specific aluminum nitride powder, an aluminum nitride mixed powder was prepared in the same manner as in Example 1, and a sheet body was obtained using this, and the thermal conductivity was measured. The results are also shown in Table 1.
実施例４
窒化アルミニウム顆粒と凸部形成用粉末の混合比を１００：２０にした以外は実施例１と同様にして窒化アルミニウム粉末を得た。得られた窒化アルミニウム粉末の比表面積、平均粒径、表面凸部高さ、表面凸部頻度の測定結果を表１に示す。さらに得られた特定窒化アルミニウム粉末は、実施例１と同様に窒化アルミニウム混合粉末を調製し、また、これを使用したシート体を得、熱伝導率を測定した。結果を表１に併せて示す。
Example 4
An aluminum nitride powder was obtained in the same manner as in Example 1, except that the mixing ratio of the aluminum nitride granules and the powder for forming the convex portion was 100:20. The measurement results of the specific surface area, average particle size, surface convex portion height, and surface convex portion frequency of the obtained aluminum nitride powder are shown in Table 1. Furthermore, the obtained specific aluminum nitride powder was used to prepare an aluminum nitride mixed powder in the same manner as in Example 1, and a sheet body was obtained using this, and the thermal conductivity was measured. The results are also shown in Table 1.
比較例１
原料に凸部形成用粉末を添加しない以外は実施例１と同様にして、窒化アルミニウム粉末を得た。得られた窒化アルミニウム粉末の比表面積、平均粒径、表面凸部高さ、表面凸部頻度の測定結果を表１に示す。さらに得られた窒化アルミニウム粉末を用いて、実施例１と同様に窒化アルミニウム混合粉末を調製し、また、これを使用したシート体を得、熱伝導率を測定した。結果を表２に併せて示す。
Comparative Example 1
An aluminum nitride powder was obtained in the same manner as in Example 1, except that no powder for forming convex portions was added to the raw materials. The results of measuring the specific surface area, average particle size, surface convex portion height, and surface convex portion frequency of the obtained aluminum nitride powder are shown in Table 1. Furthermore, using the obtained aluminum nitride powder, an aluminum nitride mixed powder was prepared in the same manner as in Example 1, and a sheet body was obtained using this, and the thermal conductivity was measured. The results are also shown in Table 2.
比較例２
原料に凸部形成用粉末を添加しない以外は実施例２と同様にして、窒化アルミニウム粉末を得た。図２は得られた窒化アルミニウム粉末の電子顕微鏡写真であるが、表面に３μｍ以下の微細な凹凸を持つ粒子であることがわかる。得られた窒化アルミニウム粉末の比表面積、平均粒径、表面凸部高さ、表面凸部頻度の測定結果を表２に示す。さらに得られた窒化アルミニウム粉末と比較例１で得られた窒化アルミニウム粉末と、Ｄ５０が０．８μｍの市販の窒化アルミニウム粉末を１：１：１の容量比で混合して窒化アルミニウム混合粉末とし、これを用いて実施例１と同様にしてシート体を得、熱伝導率を測定した。結果を表２に併せて示す。
Comparative Example 2
Aluminum nitride powder was obtained in the same manner as in Example 2, except that no powder for forming convex portions was added to the raw material. FIG. 2 is an electron microscope photograph of the obtained aluminum nitride powder, and it can be seen that the particles have fine irregularities of 3 μm or less on the surface. The measurement results of the specific surface area, average particle size, surface convexity height, and surface convexity frequency of the obtained aluminum nitride powder are shown in Table 2. Furthermore, the obtained aluminum nitride powder, the aluminum nitride powder obtained in Comparative Example 1, and a commercially available aluminum nitride powder having a D 50 of 0.8 μm were mixed in a volume ratio of 1:1:1 to obtain an aluminum nitride mixed powder, which was used to obtain a sheet body in the same manner as in Example 1, and the thermal conductivity was measured. The results are also shown in Table 2.
比較例３
窒化アルミニウム顆粒と凸部形成用粉末の混合比を１００：３にした以外は実施例１と同様にして窒化アルミニウム粉末を得た。得られた窒化アルミニウム粉末の比表面積、平均粒径、表面凸部高さ、表面凸部頻度の測定結果を表２に示す。さらに得られた窒化アルミニウム粉末は、実施例１と同様に窒化アルミニウム混合粉末を調製し、また、これを使用したシートを作製し、熱伝導率を測定した。結果を表２に示す。
Comparative Example 3
Aluminum nitride powder was obtained in the same manner as in Example 1, except that the mixing ratio of aluminum nitride granules and powder for forming convex portions was 100:3. The results of measuring the specific surface area, average particle size, surface convex portion height, and surface convex portion frequency of the obtained aluminum nitride powder are shown in Table 2. Furthermore, the obtained aluminum nitride powder was used to prepare an aluminum nitride mixed powder in the same manner as in Example 1, and a sheet was made using this, and the thermal conductivity was measured. The results are shown in Table 2.
本発明で得られる特定窒化アルミニウム焼結顆粒を含む窒化アルミニウム粉末は、フィラーに適した形状、粒径を有していることから、単独で、又は他の窒化アルミニウム粉末と混合して使用することで、樹脂やグリースなどのマトリックスに対して高充填することができ、かつ粒子間の接触面積が大きい。そのため熱伝導率の高い放熱シート、放熱グリース、放熱接着剤等を得ることができる。 The aluminum nitride powder containing the specific aluminum nitride sintered granules obtained by the present invention has a shape and particle size suitable for use as a filler, and therefore can be used alone or in a mixture with other aluminum nitride powders to achieve high filling in matrices such as resins and greases, and to achieve a large contact area between particles. This makes it possible to obtain heat dissipation sheets, heat dissipation greases, heat dissipation adhesives, etc., with high thermal conductivity.
１ 粒子の輪郭線
２ 凸部の頂点
３ 谷部の最低点
４ 谷部の最低点
1 Particle contour line 2 Peak of convex part 3 Lowest point of valley part 4 Lowest point of valley part
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021049076A JP7645676B2 (en) | 2021-03-23 | 2021-03-23 | Aluminum nitride sintered granules |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021049076A JP7645676B2 (en) | 2021-03-23 | 2021-03-23 | Aluminum nitride sintered granules |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2022147702A JP2022147702A (en) | 2022-10-06 |
| JP7645676B2 true JP7645676B2 (en) | 2025-03-14 |
Family
ID=83462458
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2021049076A Active JP7645676B2 (en) | 2021-03-23 | 2021-03-23 | Aluminum nitride sintered granules |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7645676B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024219229A1 (en) | 2023-04-18 | 2024-10-24 | 日本特殊陶業株式会社 | Holding device |
| CN119841646B (en) * | 2025-02-18 | 2025-12-02 | 厦门芯华特瓷新材料有限公司 | A method for preparing aluminum nitride thermally conductive filler with high sphericity |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016037438A (en) | 2014-08-12 | 2016-03-22 | 株式会社トクヤマ | Aluminum nitride particles and method for producing the same |
| JP2019108236A (en) | 2017-12-18 | 2019-07-04 | 株式会社トクヤマ | Aluminum nitride granular powder |
| JP2020147474A (en) | 2019-03-15 | 2020-09-17 | 株式会社トクヤマ | Composite filler and resin composition |
-
2021
- 2021-03-23 JP JP2021049076A patent/JP7645676B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016037438A (en) | 2014-08-12 | 2016-03-22 | 株式会社トクヤマ | Aluminum nitride particles and method for producing the same |
| JP2019108236A (en) | 2017-12-18 | 2019-07-04 | 株式会社トクヤマ | Aluminum nitride granular powder |
| JP2020147474A (en) | 2019-03-15 | 2020-09-17 | 株式会社トクヤマ | Composite filler and resin composition |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2022147702A (en) | 2022-10-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5607928B2 (en) | Mixed boron nitride composition and method for producing the same | |
| CN1307047C (en) | High solid content hexagonal boron nitride slurry, paste, spherical particle powder, and their preparation and use methods | |
| JP4998744B2 (en) | Spherical zinc oxide particle powder and highly heat conductive composition | |
| JP6704271B2 (en) | Hexagonal boron nitride primary particle aggregate, resin composition and use thereof | |
| JP7079378B2 (en) | Boron nitride powder and its manufacturing method, as well as composite materials and heat dissipation members | |
| JP7645676B2 (en) | Aluminum nitride sintered granules | |
| KR20130138759A (en) | Aluminum nitride powder and process for manufacturing same | |
| CN113227238B (en) | Inorganic powder for heat-dissipating resin composition, heat-dissipating resin composition using same, and method for producing same | |
| JP2021506730A (en) | A powder composition containing first and second aggregates of inorganic particles, and a polymer composition containing a polymer and a powder composition. | |
| JP7292941B2 (en) | Aluminum nitride composite filler | |
| JP3937494B2 (en) | Alumina-filled resin or rubber composition | |
| CN113677648A (en) | Filler, molded body, and heat dissipating material | |
| JP7540834B2 (en) | Aluminum nitride granular powder | |
| JP3458196B2 (en) | High thermal conductive resin composition | |
| JP7506278B1 (en) | Aluminum nitride powder and resin composition | |
| JP3572692B2 (en) | α-Alumina powder-containing resin composition and rubber composition | |
| JP2023049232A (en) | Production method of spherical aluminum nitride powder | |
| KR102049600B1 (en) | method for manufacturing ceramics nano fused compositee heat-release film | |
| KR20220139422A (en) | Insulating filler and manufacturing method therefor, insulating material containing the insulating filler, and manufacturing method thereof | |
| JP7804810B1 (en) | Boron nitride powder, inorganic filler, and method for producing boron nitride powder | |
| JP2020158355A (en) | Composite structure made of aluminum nitride | |
| TW202547780A (en) | Boron nitride powder and resin composition | |
| JP2025066995A (en) | Boron nitride aggregate particles, sheet member, and method for producing boron nitride aggregate particles | |
| JP2025075815A (en) | Composite material and its manufacturing method | |
| WO2024190205A1 (en) | Magnesium oxide particle fused body and method for producing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20240116 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20241031 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20241112 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20241217 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20250204 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20250304 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7645676 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |