Composition containing ga or ga alloy and aluminum nitride filler

Abstract

A composition according to the invention contains: Ga (gallium) or a Ga alloy; and an aluminum nitride filler. The aluminum nitride filler has a property such that, with respect to a spectrum obtained by measuring the aluminum nitride filler by X-ray photoelectron spectroscopy-X-ray excitation Auger electron spectroscopy, the ratio ((PAl-O) / (PAl-N)) of the intensity of a peak (PAl-O) corresponding to an Al-O bond to the intensity of a peak (PAl-N) corresponding to an Al-N bond is 0.3 or more.　According to the present invention, it is possible to provide a composition which contains Ga or a Ga alloy and aluminum nitride and comprises high fluidity.

Description

Composition containing Ga or Ga alloy and aluminum nitride filler

[0001] The present invention relates to a composition comprising Ga or a Ga alloy and an aluminum nitride filler.

[0002] Thermal interface materials are materials used to reduce the thermal resistance of the path through which heat generated by semiconductor elements is released to a heat sink or housing, etc., and are used in a variety of forms, such as sheets, gels, and greases. Known thermal interface materials include compositions in which silicone resin, epoxy resin, or the like is filled with a thermally conductive filler such as a metal filler or ceramic filler.

[0003] For example, in Patent Document 1, the kinematic viscosity at 25°C is 10 to 500,000 mm ２ Patent Document 1 discloses an invention relating to a thermally conductive silicone composition containing an organopolysiloxane having a molecular weight of 1000 to 100000 / s, a thermally conductive filler having an average particle size of 0.01 to 100 μm, gallium or a gallium alloy having a melting point of −20 to 100° C., and an alkoxysilane compound having a specific structure. The thermally conductive filler described in Patent Document 1 is specifically zinc oxide, alumina, boron nitride, aluminum nitride, aluminum hydroxide, magnesium oxide, or the like, and the thermally conductive filler and gallium or gallium alloy mainly serve to improve the thermal conductivity of the silicone composition.

[0004] Japanese Patent Application Laid-Open No. 2023-160267

[0005] In recent years, electronic components have become smaller and denser, requiring better heat dissipation than ever before, and thermal interface materials with high thermal conductivity are in demand. While the thermally conductive silicone composition described in Patent Document 1 above has a certain degree of heat dissipation, it is difficult to significantly improve thermal conductivity because the matrix is ​​an organic silicone resin.

[0006] Ga or Ga alloys, also known as liquid metals, have a relatively low melting point, excellent workability, and a certain thermal conductivity. However, it is difficult to obtain a material with excellent heat dissipation properties using only Ga or Ga alloys. For this reason, it is possible to incorporate a metal filler with high thermal conductivity. However, in this case, the Ga or Ga alloy reacts with the incorporated metal filler, which may adversely affect storage stability and fluidity.

[0007] Therefore, the present inventors have investigated a composition containing Ga (gallium) or a Ga alloy and aluminum nitride, a ceramic with high thermal conductivity. However, it has been found that the simple use of aluminum nitride does not result in a paste-like composition, and fluidity is reduced, resulting in poor operability and workability. In view of this background, an object of the present invention is to provide a composition containing Ga (gallium) or a Ga alloy and aluminum nitride that has high fluidity.

[0008] As a result of extensive research to achieve the above object, the present inventors have found that Ga or Ga alloys and Al—O bond peaks (P Ａｌ－Ｏ ) and the peak of the Al-N bond (P Ａｌ－Ｎ ) and the intensity ratio ((P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The present inventors have found that the above problems can be solved by using a composition containing an aluminum nitride filler having a specific or higher ratio of .alpha.-z to .alpha.-z.beta. ...

[0009] The gist of the present invention is the following [1] to [4]: ​​[1] A composition containing Ga or a Ga alloy and an aluminum nitride filler, wherein the aluminum nitride filler has a peak of Al—O bond (P Ａｌ－Ｏ ) and the peak of the Al-N bond (P Ａｌ－Ｎ ) and the intensity ratio ((P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ)) is 0.3 or more. [2] The composition according to the above item [1], wherein the filling rate of the aluminum nitride filler is 30 to 70 volume %. [3] An electronic component using a thermal interface material comprising the composition according to the above item [1] or [2]. [4] A composition in which, in a spectrum obtained by measurement using X-ray photoelectron spectroscopy-X-ray excited Auger electron spectroscopy, the peak of an Al-O bond (P Ａｌ－Ｏ ) and the peak of the Al-N bond (P Ａｌ－Ｎ ) and the intensity ratio ((P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ )) is 0.3 or more.

[0010] According to the present invention, it is possible to provide a composition containing Ga (gallium) or a Ga alloy and aluminum nitride, which has high fluidity.

[0011] The composition of the present invention contains Ga or a Ga alloy and an aluminum nitride filler, and the aluminum nitride filler has a peak (P Ａｌ－Ｏ ) and the peak of the Al-N bond inside the particle (P Ａｌ－Ｎ ) and the intensity ratio ((P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ )) is 0.3 or more. Each component constituting the composition of the present invention will be described below.

[0012] <Ga or Ga Alloy> The composition of the present invention contains Ga or a Ga alloy. Ga or a Ga alloy has a higher thermal conductivity than resin, and therefore the thermal conductivity of the composition can be made higher than that of conventional compositions in which a thermally conductive filler such as aluminum nitride is filled into a resin.

[0013] The melting point of Ga or Ga alloy is not particularly limited, but is preferably 0 to 40°C, and more preferably 5 to 38°C. When the melting point of Ga or Ga alloy is within the above range, it is easily melted when preparing a composition with an aluminum nitride filler, improving workability. Ga is metallic gallium, and its melting point is 29.8°C. The melting point of the Ga alloy can be adjusted by the composition of the Ga alloy. The melting point can be confirmed, for example, by differential scanning calorimetry (DSC).

[0014] Among Ga or Ga alloys, Ga alloys are preferred from the viewpoint of having a low melting point and increasing the fluidity of the composition. Ga alloys are alloys of Ga and metals other than Ga. The other metals are not particularly limited, but examples include one or more metals selected from the group consisting of In (indium), Sn (tin), Zn (zinc), and Bi (bismuth). Examples of Ga alloys include Ga-In (gallium-indium alloy), Ga-In-Sn (gallium-indium-tin alloy), Ga-Sn-Zn (gallium-tin-zinc alloy), and Ga-In-Bi-Sn (gallium-indium-bismuth-tin alloy). Among these, the alloys having the above-mentioned intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ From the viewpoint of improving fluidity and thermal conductivity when combined with an aluminum nitride filler having a % SiO 2 (SiO 3 ) of 0.3 or more, Ga—In—Sn (gallium-indium-tin alloy) is preferred. The proportion of Ga in the Ga alloy is not particularly limited and may be adjusted appropriately from the viewpoint of adjusting the melting point and thermal conductivity of the Ga alloy, but is, for example, 5% by mass or more, preferably 30% by mass or more, and more preferably 50% by mass or more.

[0015] The amount of Ga or Ga alloy in the composition of the present invention is not particularly limited, but is preferably 30 vol% or more, more preferably 40 vol% or more, and is preferably 70 vol% or less, more preferably 60 vol% or less.

[0016] <Aluminum Nitride Filler> The composition of the present invention contains an aluminum nitride filler together with Ga or a Ga alloy. Since the aluminum nitride filler is a filler with high thermal conductivity, the composition containing the aluminum nitride filler has excellent heat dissipation properties.

[0017] The aluminum nitride filler in the present invention has a peak of Al—O bond (P Ａｌ－Ｏ ) and the peak of the Al-N bond (P Ａｌ－Ｎ ) and the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) is 0.3 or more.

[0018] The strength ratio of the aluminum nitride filler (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ If the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ If the strength ratio (P) is less than 0.3, when the amount of aluminum nitride filler is increased, the composition is no longer in a paste state, the fluidity is reduced, and the workability is deteriorated. Ａｌ－Ｏ ) / (P Ａｌ－Ｎ When an aluminum nitride filler having a ρ of less than 0.3 is used, the amount of aluminum nitride filler to be blended must be reduced, and in this case, it becomes difficult to increase the thermal conductivity of the composition.

[0019] In contrast, the aluminum nitride filler of the present invention has the above strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ When the strength ratio (P) is 0.3 or more, the paste properties can be maintained even when the thermal conductivity of the composition is improved by increasing the filling amount of Ga or Ga alloy, and the paste has high fluidity and good workability. The reason for this is not clear, but it is presumed as follows. That is, Ａｌ－Ｏ ) / (P Ａｌ－Ｎ) is high, this means that the amount of Al—O bonds (bonds between aluminum and oxygen) on the surface of the aluminum nitride particles is large relative to the amount of Al—N bonds (bonds between aluminum and nitrogen), and specifically, this means that the oxide film layer on the surface of the aluminum nitride particles that make up the aluminum nitride filler is thick. It is thought that the presence of this oxide film layer (Al—O bond layer) improves the interaction between the aluminum nitride filler and Ga or Ga alloy, appropriately improving the compatibility between them, and as a result, it is possible to increase the loading amount of the aluminum nitride filler.

[0020] The strength ratio of the aluminum nitride filler (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) is preferably 0.4 or more, more preferably 0.6 or more, and even more preferably 0.8 or more, from the viewpoint of increasing the filling amount with Ga or Ga alloy. In addition, from the viewpoint of thermal conductivity, it is preferable that the thickness of the oxide film layer is set to a certain value or less. Therefore, the above-mentioned strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) is preferably 1.5 or less, more preferably 1.2 or less.

[0021] In the present invention, the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) is a value determined using the peak intensity of a spectrum obtained by X-ray excited Auger electron spectroscopy (hereinafter also referred to as "XAES"), as will be described in detail in the Examples.

[0022] The peak of the Al—O bond on the particle surface by the XAES (P Ａｌ－Ｏ ) and the peak of the Al-N bond inside the particle (P Ａｌ－Ｎ As described in the measurement method in the Examples below, the measurement of the surface roughness (S) of aluminum nitride particles is not a measurement of each individual aluminum nitride particle that constitutes the aluminum nitride filler, but is performed on multiple aluminum nitride particles present in a certain area, and is the average value of the aluminum nitride particles that constitute the aluminum nitride filler.

[0023] In the present invention, the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－ＮThe method for producing an aluminum nitride filler having an intensity ratio (P) of 0.3 or more is not particularly limited. For example, a general aluminum nitride filler (i.e., Ａｌ－Ｏ ) / (P Ａｌ－Ｎ An aluminum nitride filler having an intensity ratio (P) of less than 0.3 is subjected to a heat treatment in an atmosphere containing oxygen, Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) to fall within the above range.

[0024] The optimum conditions for heat treatment of the aluminum nitride filler vary slightly depending on the particle size. However, the optimum conditions are set at 400 to 1000°C, preferably 800 to 900°C, in an air atmosphere with a dew point of -20°C or less, and the strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ It is preferable to treat for a time period in which the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) becomes difficult to adjust.

[0025] Furthermore, it is desirable that the materials of the equipment and jigs used in the heat treatment are metals or dense ceramics with low moisture absorption. If the material of the equipment used in the heat treatment is highly hygroscopic, such as brick, the adsorbed moisture becomes an oxidation source, and the strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) becomes difficult to control.

[0026] A more preferred embodiment of the heat treatment is to evacuate the aluminum nitride filler to 20 Pa or less, preferably 10 Pa or less, before heating it. This embodiment makes it possible to remove moisture and other substances present between the aluminum nitride particles, and to form a dense Al—O bonded layer on the particle surfaces by the subsequent oxidation treatment. Furthermore, it is preferable to recover the aluminum nitride filler from the heating furnace after the heat treatment when its temperature has dropped to 100° C. or less, since this prevents the Al—O bonded layer from being altered by the action of moisture in the air.

[0027] The aluminum nitride filler in the present invention may be obtained by reduction nitridation or direct nitridation, or may consist of aluminum nitride sintered granules obtained by molding aluminum nitride fine powder obtained by reduction nitridation or direct nitridation and sintering the molded product.

[0028] In the composition of the present invention, the above-mentioned intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The filling rate of the aluminum nitride filler having a ρ of 0.3 or more is preferably 30% by volume or more, more preferably 40% by volume or more, and preferably 70% by volume or less, more preferably 60% by volume or less. The filling rate of the aluminum nitride filler means the amount (volume %) of the aluminum nitride filler in the entire composition. When the filling rate of the aluminum nitride filler is equal to or more than these lower limit values, it becomes easy to increase the thermal conductivity of the composition, and when the filling rate of the aluminum nitride filler is equal to or less than these upper limit values, it becomes easy to maintain the paste-like properties of the composition and to improve workability.

[0029] The above-mentioned intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The aluminum nitride filler having a strength ratio (P) of 0.3 or more can be highly filled with Ga or Ga alloy. Ａｌ－Ｏ ) / (P Ａｌ－Ｎ An aluminum nitride filler having a ρ of 0.3 or more can be suitably used as an aluminum nitride filler for filling Ga or a Ga alloy.

[0030] In the present invention, the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－ＮThe average particle size (D50) of the aluminum nitride filler having a D50 of 0.3 or more is not particularly limited, but is preferably 0.7 to 200 μm, more preferably 10 to 150 μm, and even more preferably 15 to 100 μm. When the average particle size (D50) of the aluminum nitride filler is equal to or greater than these lower limits, the thermal conductivity of the composition is easily increased. When the average particle size (D50) of the aluminum nitride filler is equal to or less than these upper limits, the composition can be easily used as a thin thermal interface material. The average particle size of the filler can be measured using a laser diffraction / scattering particle size distribution analyzer. A volume frequency distribution curve is obtained with particle size (μm) on the horizontal axis and volume frequency on the vertical axis, and the particle size (D50) at which the cumulative curve of the measured volume-based particle size distribution reaches 50% is defined as the average particle size. The aluminum nitride filler of the present invention may contain impurities such as alkaline earth metal elements and rare earth elements derived from the raw materials or intentionally added during the synthesis process, up to an upper limit of approximately 5 mass%. Alkaline earth metal elements and rare earth elements are contained in sintering aids, particularly when producing aluminum nitride sintered granules, and when the aluminum nitride filler is in the form of sintered granules, the content of these impurities in the aluminum nitride filler can be 1 to 5 mass%, particularly 2 to 4 mass%. Furthermore, since a large amount of impurities can reduce the crystallinity of aluminum nitride and cause a decrease in thermal conductivity, when the aluminum nitride filler is not in the form of sintered granules, the content of these impurities in the aluminum nitride filler is preferably 1.0 mass% or less, more preferably 0.5 mass% or less, and even more preferably 0.1 mass% or less.

[0031] As described above, in the present invention, the average particle size (D50) is 0.7 to 200 μm, and the intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ It is preferable to use an aluminum nitride filler having an average particle size (D50) and a strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ When a plurality of types are used in combination, the average particle size (D50) and the intensity ratio (P Ａｌ－Ｏ) / (P Ａｌ－Ｎ ) are the average particle size and strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) and the blending amount. In addition to the aluminum nitride filler, other fillers besides aluminum nitride filler may be blended. Examples of other fillers include aluminum oxide, silicon nitride, boron nitride, and silicon dioxide, with aluminum oxide being preferred. The average particle size (D50) of the other filler is not particularly limited, but from the viewpoint of increasing the overall filler loading in the composition, it is preferably less than 5 μm, more preferably 3 μm or less, even more preferably 2 μm or less, and preferably 0.1 μm or more, more preferably 0.2 μm or more.

[0032] When other fillers are used, the average particle size of the other fillers is preferably smaller than that of the aluminum nitride filler, preferably 0.3 times or less, more preferably 0.1 times or less, of the average particle size of the aluminum nitride filler, and preferably 0.005 times or more, more preferably 0.01 times or more, of the average particle size of the aluminum nitride filler.

[0033] When other fillers are used, the volume ratio of the other fillers to the aluminum nitride filler in the composition (other fillers / aluminum nitride filler) is preferably 0.05 to 1, and more preferably 0.1 to 0.5, from the viewpoint of increasing the loading amount in Ga or Ga alloy.

[0034] When a mixed filler containing aluminum nitride filler in combination with other fillers is used, the content of the aluminum nitride filler in the composition is preferably 60% by volume or more, more preferably 70% by volume or more, and preferably 95% by volume or less, more preferably 90% by volume or less, based on the total volume of the filler.

[0035] In the composition of the present invention, the filling rate of all fillers is preferably 30% by volume or more, more preferably 40% by volume or more, and preferably 70% by volume or less, more preferably 60% by volume or less, from the viewpoints of improving the thermal conductivity of the composition and the fluidity of the composition. The filling rate of all fillers means the filling rate of all fillers contained in the composition, and corresponds to the content (volume %) of all fillers in the entire composition.

[0036] <Other Components> The composition of the present invention contains Ga or a Ga alloy, an intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ In addition to the aluminum nitride filler having a % saturation index (SAR) of 0.3 or more, a dispersant or the like may be contained as needed within a range that does not impair the effects of the present invention. The composition of the present invention may also contain an organic substance such as a resin, but from the viewpoint of improving the thermal conductivity and fluidity of the composition, it is preferable that the amount of organic substance be as small as possible. The amount of organic substance in the composition of the present invention is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably 0% by mass.

[0037] <Thermal Conductivity> Compared to materials using a resin such as a conventional silicone resin as a matrix, the composition of the present invention has excellent thermal conductivity because it uses Ga or a Ga alloy as a matrix. The thermal conductivity of the composition of the present invention is, for example, 15 W / m K or more, preferably 30 W / m K or more. The upper limit of the thermal conductivity is not particularly limited, but can be, for example, 150 W / m K or less. The thermal conductivity can be measured by the method described in the examples.

[0038] The composition of the present invention is prepared by mixing the components, and the mixing can be performed using various mixers, etc. When preparing the composition, the composition may be heated, for example, to about 40 to 150°C, as necessary.

[0039] The composition of the present invention has high fluidity, and even when the filling rate of aluminum nitride filler is increased, the composition can maintain its paste properties and exhibit good workability. Furthermore, because the composition of the present invention has high thermal conductivity, it can be suitably used as a thermal interface material with excellent heat dissipation properties for various electronic components.

[0040] EXAMPLES The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0041] [Measurement Methods] Various physical properties in the examples and comparative examples were measured by the following methods.

[0042] (1) Average particle size: This was determined by a laser diffraction / scattering method using a Nikkiso Microtrack-HRA. Aluminum nitride filler was added to a solution of 90 ml of water with a 5% aqueous solution of sodium pyrophosphate, and the resulting solution was dispersed in a homogenizer at an output of 200 mA for 3 minutes, after which measurement was performed. The average particle size was determined from the D50 obtained by the above method. Note that D50 is the particle size at which the cumulative volume of the particles is 50%.

[0043] (2) Intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) Intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) is the peak intensity (P) at an Auger electron energy of 1386.7 eV measured using the following equipment and conditions. Ａｌ－Ｏ ) and the peak intensity of 1388.5 eV (P Ａｌ－Ｎ The intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ For the measurement of ), reference can be made to JP 2020-125228 A.

[0044] Apparatus: X-ray photoelectron spectrometer ESCA5701ci / MC manufactured by ULVAC-PHI, Inc. X-ray source: Mg-Kα ray 14.0 kV-25.7 mA Vacuum degree: 5.0 × 10 －７Pa Aperture diameter (analysis area): Φ800 μm Photoelectron take-off angle: 45 deg. Neutralization gun: A neutralization gun was used to mitigate the effect of sample charging on the XPS-XAES spectrum shape. Charging correction: The carbon C1s peak of the measurement spectrum was adjusted to 284.6 eV to correct the peak shift due to charging. Measurement parameters: For high energy resolution (Multiplex Scan) Pass Energy / eV: 11.75, ΔV / V Interval: 0.05, Interval Time / ms: 50

[0045] (3) Compound Properties The properties of the compositions (compounds) prepared in each Example and Comparative Example were evaluated according to the following criteria: A: Paste-like and fluid. B: Not paste-like, heterogeneous, and partially powdery.

[0046] (4) Thermal Conductivity The composition prepared in the examples was applied to a 10 mm x 10 mm silicon chip, and another 10 mm x 10 mm silicon chip was placed on top of it. The composition was sandwiched between the two silicon chips and crushed with a force of 50 N for 120 seconds using a push-pull gauge (manufactured by Imada Co., Ltd., SVH-1000N) to obtain a sample. The thickness of the sample was then measured using a micrometer (manufactured by Mitutoyo Corporation, high-precision digimatic micrometer MDH-25MB). The thickness of the silicon chip, which had been measured previously, was then subtracted from the thickness of the obtained sample to calculate the thickness of the composition alone. Using this sample, the thermal conductivity at 25 ° C. was measured using a laser flash method (manufactured by NETZSCH, LFA467 HyperFlash). The value obtained by subtracting the thermal conductivity of the silicon chip, which had been measured previously, was used as the thermal conductivity of the composition.

[0047] The Ga alloys and fillers used in the examples and comparative examples are as follows:

[0048] <Ga alloy> Ga-In-Sn (gallium-indium-tin alloy) Composition (mass%): Ga / In / Sn = 62 / 25 / 13 Melting point: 5°C

[0049] <Aluminum nitride filler> The following aluminum nitride fillers were used: AlN-1: "HF-20" manufactured by Tokuyama Corporation, average particle size D50 of 18 μm, strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ) is 0.34 aluminum nitride filler

[0050] AlN-2: Intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ Aluminum nitride filler having a D50 of 30 μm and a strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The mixture was charged into a furnace with a muffle made of SUS310 so that the thickness was 20 mm, and after the pressure inside the furnace was set to 20 Pa, air with a dew point of -20°C was introduced to return the pressure to normal pressure, and the mixture was heat-treated in this atmosphere at 800°C for 5 hours, and the strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ An aluminum nitride filler composed of sintered aluminum nitride granules having a particle size distribution (P / S) adjusted to 0.57 was obtained.

[0051] AlN-3: Intensity ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ Aluminum nitride filler with a D50 of 81 μm and a strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The mixture was charged into a furnace with a muffle made of SUS310 so that the thickness was 20 mm, and after the pressure inside the furnace was set to 20 Pa, air with a dew point of -20°C was introduced to return the pressure to normal pressure, and the mixture was heat-treated under the conditions of 1000°C x 5 hours in this atmosphere, and the strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ An aluminum nitride filler composed of sintered aluminum nitride granules having a molecular weight of 1.2 was obtained.

[0052] AlN-4: Aluminum nitride sintered granules (D50: 18 μm, strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ Aluminum nitride filler consisting of aluminum nitride sintered granules (D50: 81 μm, strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ ): 0.22) aluminum nitride filler

[0053] <Al ２ O ３ Aluminum oxide: "AA-1.5" (average particle size D50 = 1.5 μm) manufactured by Sumitomo Chemical Co., Ltd.

[0054] Example 1 A composition was prepared by mixing an aluminum nitride filler (AlN-1) and a Ga alloy (Ga—In—Sn). The blending ratio was as shown in Table 1, with the aluminum nitride filler (AlN-1) being 25.4 mass% and the Ga alloy being 74.6 mass%. The compound properties and thermal conductivity of the composition were evaluated, and the results are shown in Table 1.

[0055] Examples 2 to 4, Comparative Examples 1 and 2 Compositions were prepared in the same manner as in Example 1, except that the compounding ratios were changed to those shown in Table 1. In Example 4, as shown in Table 1, aluminum nitride filler (AlN-1) and aluminum oxide (Al ２ O ３ The compound properties and thermal conductivity of the composition were evaluated, and the results are shown in Table 1.

[0056]

[0057] The compositions of Examples 1 to 4 are Ga alloys and the strength ratio (P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The composition satisfies the requirements of the present invention and contains an aluminum nitride filler with a strength ratio (P) of 0.3 or more. The composition is pasty, has high fluidity, and is also excellent in thermal conductivity. Ａｌ－Ｏ ) / (P Ａｌ－Ｎ The compositions of the comparative examples that did not contain an aluminum nitride filler having a viscosity of 0.3 or more were not paste-like and had poorer fluidity than the examples. Furthermore, because the compositions of the comparative examples were not paste-like, it was not possible to properly evaluate the thermal conductivity.

Claims

1. A composition comprising Ga or a Ga alloy and an aluminum nitride filler, wherein the aluminum nitride filler has a peak of an Al—O bond (P) in a spectrum obtained by measurement using X-ray photoelectron spectroscopy-X-ray excited Auger electron spectroscopy. Ａｌ－Ｏ ) and the peak of the Al-N bond (P Ａｌ－Ｎ ) and the intensity ratio ((P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ )) is 0.3 or greater.

2. The composition according to claim 1, wherein the loading of the aluminum nitride filler is 30 to 70 volume percent.

3. An electronic component using a thermal interface material comprising the composition of claim 1 or 2.

4. X-ray photoelectron spectroscopy - The spectrum obtained by measuring with X-ray excited Auger electron spectroscopy shows the peak of Al-O bond (P Ａｌ－Ｏ ) and the peak of the Al-N bond (P Ａｌ－Ｎ ) and the intensity ratio ((P Ａｌ－Ｏ ) / (P Ａｌ－Ｎ )) is 0.3 or more.

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