Slurry composition and resin composite composition containing the same

Abstract

To provide a slurry composition that has good adhesion to resin materials and dispersion stability, regardless of whether or not the filler (inorganic particles) are surface-treated. [Solution] A slurry composition comprising spherical silica particles and a dispersion medium, The average sedimentation velocity of the spherical silica particles measured at a concentration of 45-75 wt% was 0.1-20.0 μm / sec. A slurry composition characterized in that the value of the following formula (1) is greater than 3.0 and less than or equal to 20.0. Equation (1) Average particle diameter of spherical silica particles (μm) × Specific surface area of ​​spherical silica particles (m²) 2 / g)

Description

[Technical Field]

[0001] The present invention relates to slurry compositions, particularly slurry compositions comprising silica particles and a solvent, and resin composite compositions containing the same. [Background technology]

[0002] In recent years, semiconductor packages used in electronic components and communication equipment have become smaller and thinner, and consequently, there is a growing need for miniaturization of substrate materials such as semiconductor encapsulants and insulating layers of package substrates. For these semiconductor components, it is common to use resin compositions in which fillers (inorganic particles) are filled into resin materials to control the coefficient of linear expansion in order to provide mechanical strength and suppress warping. Methods for manufacturing such resin compositions include kneading dried fillers with a matrix resin using a kneader or a three-roll kneader, as well as dispersing the fillers in a dispersion medium, mixing the resulting slurry with the matrix resin, and removing the dispersion medium by heat treatment to obtain a resin composition in which the fillers are dispersed in the resin material. This method has advantages over methods in which fillers and resins are directly kneaded, such as being able to uniformly disperse the fillers in the resin material.

[0003] Therefore, slurry compositions or their fillers used in semiconductor peripheral components and the like have been studied from various perspectives, including fluidity or filling properties during sealing, adhesion to resin materials, and dispersion stability of the filler within the slurry.

[0004] For example, it is preferable to have a small amount of dispersion medium in the resin composition obtained by mixing a slurry composition into a resin material, and there is a demand for high-concentration inorganic particle slurries. Patent Document 1 discloses a method for producing a high-concentration slurry composition, in which the dispersion medium is removed after preparing a slurry composition of relatively low concentration to increase the concentration.

[0005] Furthermore, when using a slurry mixed with a resin material, defects often occur due to insufficient adhesion between the inorganic particles in the slurry and the resin. Patent Document 2 describes improving adhesion to inorganic particles through surface treatment. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-025722 [Patent Document 2] Patent No. 6347644 [Overview of the project] [Problems that the invention aims to solve]

[0007] As described above, the slurry composition or its fillers have been studied from various perspectives, but there is still room for further performance improvement.

[0008] For example, Patent Document 1 presents a method for producing a high-concentration slurry composition, but generally, the dispersibility of fillers can be a problem with high-concentration slurry compositions. Specifically, even if a slurry composition containing a high concentration of fillers can be prepared, if the dispersion is insufficient, the fillers will exist as aggregates in the high-concentration slurry composition. These aggregates, being large particles, will settle quickly, creating a concentration gradient and resulting in insufficient stability over time.

[0009] Furthermore, while Patent Document 2 proposes improving adhesion to inorganic particles through surface treatment, surface treatment alone is often insufficient to improve adhesion, and uneven or excessive treatment can worsen adhesion.

[0010] In view of this, the object of the present invention is to provide a slurry composition and a resin composite composition containing the same, which have good adhesion to a resin material and dispersion stability, regardless of whether or not the filler (inorganic particles) are surface-treated. [Means for solving the problem]

[0011] First, the inventors discovered that increasing the specific surface area of ​​fillers (inorganic particles) can increase the adhesive interface area between particles and resin, thereby improving adhesion. On the other hand, increasing the specific surface area of ​​particles can sometimes worsen the dispersion stability of particles in slurry. However, by evaluating the sedimentation velocity of particles in slurry in its raw state, the inventors found that it is possible to achieve both adhesion and dispersion stability if the slurry has a sedimentation velocity within a specific range.

[0012] Based on these findings, the gist of the present invention is as follows. [1] A slurry composition comprising spherical silica particles and a dispersion medium, The specific surface area of ​​the aforementioned spherical silica particles is 18.4 m². 2 It is less than, The average sedimentation velocity of the spherical silica particles measured at a concentration of 45-75 wt% was 0.1-20.0 μm / sec. A slurry composition characterized in that the value of the following formula (1) is greater than 3.0 and less than or equal to 20.0. Equation (1) Average particle diameter of spherical silica particles (μm) × Specific surface area of ​​spherical silica particles (m²) 2 / g) [2] The slurry composition according to [1], wherein the value of formula (1) is 3.21 or greater and less than 6.27. [3] The slurry composition according to [1] or [2], wherein the spherical silica particles have an average particle diameter (D50) of 0.1 μm or more and 3.0 μm or less as determined by laser diffraction scattering. [4] The slurry composition according to any one of [1] to [3], wherein the circularity of the spherical silica particles is 0.85 or greater. [5] When the number frequency of particles of 1 to 2 μm is A and the number frequency of particles of 2 to 30 μm is B among the number of particles of 1 μm or more and 30 μm or less detected by a Coulter counter for the spherical silica particles, the slurry composition according to any one of [1] to [4], wherein B / A is 0.002 or more and 0.20 or less. [6] The slurry composition according to any one of [1] to [5], wherein, among the particles of 1 μm or more and 30 μm or less detected by a Coulter counter for the spherical silica particles, the particles of 10 μm or more are less than 10 ppm. [7] The slurry composition according to any one of [1] to [6], wherein the relative dielectric constant of the dispersion medium is 5 to 30. [8] A resin composite composition comprising the slurry composition according to any one of [1] to [7].

Advantages of the Invention

[0013] The slurry composition according to the present invention is excellent in dispersion stability, and in the resin composite composition containing the slurry composition, the adhesion between the resin and the spherical silica particles (silica filler) is excellent. Further, a resin composite composition containing the slurry composition can be obtained.

Modes for Carrying Out the Invention

[0014] A slurry composition, which is one embodiment of the present invention, is a slurry composition containing spherical silica particles and a dispersion medium.

[0015] 〈Specific Surface Area of Spherical Silica Particles〉 The spherical silica particles have a specific surface area of less than 18.4 m 2 / g.

[0016] The specific surface area of the spherical silica particles can also be measured by the BET method in which the BET theory is applied to the adsorption isotherm measured by the gas adsorption method, and can be measured using the product name “Macsorb Model HM-1208” manufactured by Mountech Co., Ltd. as a specific surface area measuring machine.

[0017] Generally, as the specific surface area of spherical silica particles increases, the tendency for aggregation between particles increases, and the fluidity of the slurry composition or resin composite composition (such as a sealing material) may decrease, or the adhesion to the resin may decrease. Therefore, the specific surface area of the spherical silica particles is less than 18.4 m 2 / g. It is expected that the smaller the specific surface area, the more the tendency for aggregation between particles is suppressed, and the decrease in fluidity and adhesion is also suppressed. Therefore, the specific surface area may be 18.0 m 2 / g or less, 17.0 m 2 / g or less, or 16.9 m 2 / g or less. The lower limit of the specific surface area is not particularly limited, but if it is too small, it becomes difficult for the particles to form a closest packing structure, so the fluidity and adhesion of the slurry composition of the present invention or the resin composite composition (such as a sealing material) containing the slurry composition may decrease. Also, if the specific surface area is too small, the interfacial area where the resin and the particles adhere decreases, and it may be difficult to obtain sufficient adhesion strength. Therefore, the specific surface area of the spherical silica particles may be 1.0 m 2 / g or more, preferably more than 3.0 m 2 / g, more than 3.8 m 2 / g or more, 4.0 m 2 / g or more, or more than 4.0 m 2 / g.

[0018] 〈Average sedimentation rate of spherical silica particles〉 The average sedimentation rate of spherical silica particles measured in a state where the concentration of spherical silica particles is 45 to 75 wt% is 0.1 to 20.0 μm / sec.

[0019] The slurry composition contains spherical silica particles and a dispersion medium. Generally, when the slurry composition contains spherical silica particles at a high concentration, if the dispersion of the spherical silica particles is insufficient, the spherical silica particles as fillers exist as aggregates in the high-concentration slurry composition, and the aggregates as large particles settle rapidly, resulting in a concentration gradient and insufficient stability over time. Also, a high-concentration slurry may have high viscosity and be difficult to handle. From these viewpoints, in the present embodiment, the upper limit of the concentration of spherical silica particles is 75 wt%.

[0020] The above problems can sometimes be avoided by lowering the concentration of spherical silica particles. However, in that case, the content ratio of the dispersion medium is high, reducing the interaction (contact and interference) between particles, leading to rapid sedimentation, a concentration gradient, and insufficient stability over time. Also, depending on the application, generally, increasing the concentration of silica particles reduces the relative amount of solvent, improving drying efficiency and allowing for effective handling of a large amount of silica particles with a small amount of slurry (or solvent). High-concentration slurry suitable for such applications cannot be obtained under conditions of low silica particle concentration. From these viewpoints, the lower limit of the concentration of spherical silica particles in this embodiment is set to 45 wt%.

[0021] The inventors evaluated the sedimentation velocity of spherical silica particles in a slurry composition in its raw state (high-concentration slurry) and found that a slurry composition with a sedimentation velocity within a specific range can achieve both adhesion and dispersion stability. Based on this, in this embodiment, the average sedimentation velocity of spherical silica particles was measured in a silica composition with a concentration of spherical silica particles of 45-75 wt%, and the average sedimentation velocity was 0.1-20.0 μm / sec. When the average sedimentation velocity is within this range, the dispersion stability of spherical silica particles in the slurry composition is excellent. A sedimentation velocity greater than 20.0 μm / sec indicates weak inter-particle interaction in the silica, which may lead to deterioration of dispersion stability over time. Conversely, a sedimentation velocity less than 0.1 μm / sec indicates strong inter-particle interaction in the silica, resulting in low fluidity of the slurry composition, which may lead to poor dispersibility in the matrix resin or the formation of coarse, aggregated particles.

[0022] In this embodiment, the sedimentation velocity is measured by filling the measurement cell of a centrifugal sedimentation analyzer (LUMiSizer, manufactured by LUM Japan) with the slurry composition to be measured, either in its original state or after being adjusted to a predetermined concentration, under the following conditions: rotation speed: 2,000 rpm, number of profiles: 1,000, measurement interval: 10 seconds, light intensity LF1. The sedimentation velocity distribution and average sedimentation velocity are calculated from the obtained sedimentation profile using dedicated software.

[0023] <Average particle diameter of spherical silica particles (μm) × Specific surface area of ​​spherical silica particles (m²) 2 / g)〉 Spherical silica particles have a value greater than 3.0 and less than or equal to 20.0 in the following formula (1). Equation (1) Average particle diameter of spherical silica particles (μm) × Specific surface area of ​​spherical silica particles (m²) 2 / g)

[0024] When the value of equation (1) is greater than 3.0 and less than or equal to 20.0, the adhesion between the spherical silica particles and the matrix resin is excellent. Furthermore, although we do not wish to be bound by a specific theory, it is thought that the adhesion can be improved by increasing the specific surface area of ​​the spherical silica particles, which are the filler, thereby increasing the adhesive interface area between the particles and the resin. On the other hand, if we focus only on the specific surface area, particles with extreme particle size distributions may be included. For example, it is possible that particles with very small particle size and very large specific surface area are included, and conversely, particles with very large particle size and very small specific surface area are included, and the average value of the specific surface area of ​​all particles may fall within a range that is considered appropriate. Particles with such extreme particle size distributions may result in poor fluidity and dispersibility of the slurry composition. By keeping the value of equation (1) within the above range, such a decrease in fluidity and dispersibility is suppressed. The lower or upper limit of equation (1) may be adjusted as appropriate within the above range, and by doing so, it is expected that the effect of improving adhesion or the effect of suppressing the decrease in fluidity and dispersibility will be enhanced. The lower limit of equation (1) may be greater than 3.20, 3.21 or greater, 3.28 or greater, or 3.56 or greater. The upper limit of equation (1) may be less than 7.18, less than 6.27, 6.00 or less, 5.94 or less, or 5.73 or less. The range of equation (1) may be defined by the lower or upper limits described above, and for example, the value of equation (1) may be greater than 3.20 and less than 6.27, 3.21 or greater and less than 6.27, or 3.21 or greater and 6.0 or less.

[0025] <Average particle size of spherical silica particles> The spherical silica particles may have an average particle diameter (D50) of 0.1 to 3.0 μm.

[0026] The average particle size of spherical silica particles can be determined from the particle size distribution of those particles. The particle size distribution can be measured using a dynamic light scattering particle size distribution analyzer, such as the ZETASIZER NANO manufactured by Malvern.

[0027] The average particle diameter refers to the particle diameter at which the cumulative volume accounts for 50% of the cumulative particle size distribution of spherical silica particles, and is sometimes referred to as D50 (median diameter). D100 (maximum particle size) refers to the particle diameter at which the cumulative volume accounts for 100% of the cumulative particle size distribution of spherical silica particles.

[0028] If the average particle size (D50) is less than 0.1 μm, the particle size is small, and the viscosity of the slurry composition containing these particles, and the encapsulant which is a form of resin composite composition using the same, may become too high. On the other hand, if the average particle size (D50) is greater than 3.0 μm, there will be a large amount of particles with a particle size of 3.0 μm or larger, and these particles may get stuck in the narrow space between the mounting substrate and the chip, which may reduce the fluidity of the encapsulant and decrease its moldability. The preferred lower limit is 0.20, 0.30, 0.40, or 0.50 μm. The more preferred lower limit is 1.00 μm. On the other hand, the more preferred upper limit is 2.00 μm, 1.50 μm, or 1.10 μm.

[0029] <Circularity of spherical silica particles> The spherical silica particles may have a circularity of 0.85 or higher.

[0030] The higher the circularity of the spherical silica particles, the lower the viscosity of the resin composite composition containing those particles, and the improved moldability. The circularity may be 0.90 or higher, or 0.93 or higher. Theoretically, the upper limit of circularity is 1.0, but from a manufacturing control perspective, it may be 0.98 or lower, or 0.95 or lower.

[0031] Circularity can be measured using an electron microscope or optical microscope and an image analysis device, such as the FPIA manufactured by Sysmex Corporation. These devices are used to measure the circularity of particles (perimeter of the equivalent circle / perimeter of the projected image of the particle). The circularity is measured for 100 or more particles, and the average value is taken as the circularity of the powder.

[0032] <Particle size distribution of spherical silica particles as measured by a Coulter counter> Among the spherical silica particles, if the Coulter counter detects particles between 1 μm and 30 μm in size, and the particle count frequency of 1-2 μm is A, and the particle count frequency of 2-30 μm is B, then the B / A ratio may be between 0.002 and 0.20. This means that there are more 1-2 μm particles than 2-30 μm particles, but if there are too many 1-2 μm particles, which have a large surface area, the fluidity may deteriorate. By keeping it within this range, the fluidity of the resin composite composition is appropriately ensured, and the filler filling (blending) effect is fully expressed. A more preferable lower limit for B / A is 0.01, more preferably 0.03, more preferably 0.05, and even more preferably 0.10. On the other hand, a more preferable upper limit for B / A is 0.19.

[0033] Furthermore, among the particles between 1 μm and 30 μm detected by the Coulter counter, the number frequency of particles 10 μm or larger may be less than 10 ppm. Less than 10 ppm means, for example, that when there are 1 million particles between 1 μm and 30 μm, there are fewer than 10 particles 10 μm or larger. A lower number frequency of coarse particles 10 μm or larger is preferable because it improves fluidity. If the number frequency of coarse particles 10 μm or larger is 10 ppm or higher, such coarse particles will clog in the narrow space between the mounting substrate and the chip, reducing fluidity. More preferably, it is less than 5 ppm, even more preferably less than 1 ppm, even more preferably less than 0.1 ppm, and most preferably zero.

[0034] The Coulter counter measures particles using an electrical resistance method called the Coulter principle. Unlike optical measurement methods, it avoids errors related to particle surface morphology, internal structure, refractive index, and color, resulting in high measurement accuracy. In particular, the particle size obtained by this method can be expressed as a number distribution, enabling precise control of particle size distribution.

[0035] Spherical silica particles and 150 mL of electrolyte were placed in a 200 mL glass beaker and dispersed for 30 seconds using an ultrasonic homogenizer (SMT, ULTRA SONIC HOMOGENIZER UH-300). This dispersion was then added to electrolyte prepared in another beaker to adjust the concentration. The individual particle sizes of the spherical silica particles were measured using a Coulter counter (Beckman Coulter, Multisizer 3) with an aperture diameter of 50 μm. Approximately 100,000 particles were measured per measurement, and the same sample was measured three times. Of the particles detected by the Coulter counter between 1 μm and 30 μm, the number of particles with particle sizes of 1, 2, and 10 μm or larger (or greater) was calculated and expressed as the coarse particle frequency (ppm) relative to the total number of particles measured.

[0036] <Surface treatment of spherical silica particles> The spherical silica particles contained in the slurry composition may or may not be surface-treated. Typically, they may be treated with a silane compound. Specifically, examples include compounds having at least one functional group selected from alkyl groups such as methyl, ethyl, propyl, and butyl groups, alkenyl groups such as vinyl, ethenyl, and propenyl groups, phenyl, amino, phenylamino, acrylic, methacrylic, epoxy, and styryl groups, silane coupling agents, and silazanes. Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. Examples of alkoxysilane compounds include hexyltrimethoxysilane, octyltriethoxysilane, and phenyltriethoxysilane. Examples of silazane compounds include hexamethyldisilazane and trimethylsilane. Treatment with silane compounds improves the affinity between the filler and the dispersion medium, resulting in good fluidity. In addition, resin composite compositions produced using slurry compositions also show improved high-filling properties due to improved adhesion with the matrix resin. As a surface treatment method, the filler-containing slurry composition of the present invention may be prepared using a filler that has undergone the above treatment in advance, or, depending on the surface treatment agent, it may be performed simultaneously with the preparation of the slurry composition. On the other hand, if the spherical silica particles are not surface-treated, the resin composite composition has superior strength, and the manufacturing flow is simpler, which is preferable from the standpoint of cost and production management.

[0037] <Dispersion medium> The dispersion medium used in the slurry composition is not particularly limited as long as it is a solvent capable of dispersing the spherical silica particles described above.

[0038] The dielectric constant of the dispersion medium is preferably in the range of 5 to 30, with more preferable lower limits being 8, 10, and 12, and more preferable upper limits being 25 and 20. By using a dispersion medium with a dielectric constant within the above range, a slurry composition with high affinity between spherical silica particles and the dispersion medium and excellent fluidity can be obtained, and dispersion stability may also be further improved. Typical dispersion media include cyclohexanone (relative permittivity: 18.3 (20°C)), methyl ethyl ketone (relative permittivity: 18.5 (20°C)), acetone (relative permittivity: 20.7), methyl isobutyl ketone (relative permittivity: 13.1 (20°C)), tetrahydrofuran (relative permittivity: 7.6 (25°C)), ethanol (relative permittivity: 24.6 (25°C)), cyclohexane (relative permittivity: 20.1 (20°C)), and 2-propanol (relative permittivity: 19.9 (25°C)).

[0039] <Method for preparing slurry> The slurry composition can be prepared by dispersing the above-mentioned spherical silica particle powder in a dispersion medium using a known dispersion method. Specifically, this can be done using equipment such as a three-roll mill, bead mill, ball mill, ultrasonic disperser, various mixers, kneader, and high-pressure wet atomizer.

[0040] <Dispersant> In addition to spherical silica particles and a dispersion medium, a dispersant may be added to the slurry composition to provide dispersion stability. One type of dispersant may be used, or multiple dispersants may be used in combination.

[0041] Examples of dispersants include those comprising at least one selected from nonionic dispersants and cationic dispersants. There are no particular limitations on the nonionic dispersant, and known dispersants can be used. Examples include polymer compounds having polyoxyethylene chains. Examples of polymer compounds having polyoxyethylene chains include alkyl polyoxyethylene ethers, alkyl polyoxyethylene-polyoxypropylene ethers, alkyl polyoxypropylene-polyoxyethylene ethers, polyoxyethylene-polyoxypropylene ethers (polyoxyethylene oxypropylene block copolymers), fatty acid polyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters, fatty acid polyoxyethylene sorbitol esters, polyoxyethylene sorbitan monoalkyl ethers, polyoxyethylene alkyl ether sulfate esters, polyoxyethylene castor oil (hydrogenated castor oil), acetylene glycol ethylene oxide adducts, etc. Examples of alkyl polyoxyethylene ethers include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl ether, polyoxyethylene cetyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, etc. Examples of fatty acid polyoxyethylene sorbitan esters include polyoxyethylene sorbitan monolaurate.

[0042] There are no particular limitations on the cationic dispersant, and known ones can be used. Examples include alkylamine salts, acylamine salts, quaternary ammonium salts, ammonium salts having amide, ester, or ether bonds, imidazoline, imidazolium salts, and amine derivatives. The cationic dispersant may be a low molecular weight compound or a high molecular weight compound, but from the viewpoint of dispersibility of silica particles, a high molecular weight compound is preferred. Examples of such high molecular weight dispersants include polyethyleneimine, aminoalkyl (meth)acrylate copolymers, polyvinylimidazoline, polyvinylpyridine derivatives, polyoxyethylene alkylamines, and polyoxyethylene alkylamides. Examples of polyvinylpyridine derivatives include copolymers of vinylpyridine and (meth)acrylic acid, and copolymers of vinylpyridine, (meth)acrylic acid, and oxyethylene group-containing high molecular weight compounds. Examples of copolymers of vinylpyridine, (meth)acrylic acid, and oxyethylene group-containing high molecular weight compounds include copolymers of vinylpyridine and (meth)acrylic acid and polyoxyethylene. Of these, amine-type high molecular weight dispersants are preferred from the viewpoint of dispersibility of silica particles.

[0043] Furthermore, known surface treatment agents can be used as dispersants. Including a surface treatment agent improves the dispersibility between spherical silica particles and the dispersion medium in the slurry composition, as well as the dispersibility or affinity with the resin in the resin composite composition. Examples include compounds having at least one functional group selected from alkyl groups such as methyl, ethyl, propyl, and butyl groups, alkenyl groups such as vinyl, ethenyl, and propenyl groups, phenyl, amino, phenylamino, acrylic, methacrylic, epoxy, and styryl groups, silane coupling agents, and silazanes. More preferably, silane coupling agents having SiH, SiOH, or SiOR (where R is a hydrocarbon group) and silazanes of hexamethylenedisilazanes. Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. Examples of alkoxysilane compounds include hexyltrimethoxysilane, octyltriethoxysilane, and phenyltriethoxysilane. Examples of silazane compounds include hexamethyldisilazane and trimethylsilane. From the viewpoint of superior reactivity, silazane compounds are more preferred. More preferably, they are hexamethyldisilazane and trimethylsilane.

[0044] The content of spherical silica in the slurry composition (or the combined content of "inorganic fillers" or "other fillers" described later, if applicable) can be adjusted as appropriate depending on the application of the slurry composition. Typically, from the viewpoint of exhibiting the effect of spherical silica particles, it is 50 to 95 wt%. A more preferred lower limit is 55 wt%, more preferably 60 wt%, more preferably 65 wt%, and more preferably 70 wt%. A more preferred upper limit is 93 wt%, more preferably 90 wt%, and more preferably 85 wt%.

[0045] <Resin composite composition containing slurry composition> In one embodiment of the present invention, a resin composite composition comprising a slurry composition is provided.

[0046] A resin composite composition contains a slurry composition and a resin (matrix resin), and is a composite composition formed by the combination of the slurry composition and the resin (matrix resin). The slurry composition is used to disperse spherical silica particles as fillers in the matrix resin during the molding of the resin composite composition. Specifically, the matrix resin is added to the slurry composition and mixed uniformly. Subsequently, by removing the dispersion medium through treatment such as heating, a resin composite composition in which the fillers are uniformly dispersed in the resin can be prepared.

[0047] When manufacturing the aforementioned resin composite composition, for example, in addition to spherical silica particles and matrix resin, curing agents, curing accelerators, flame retardants, silane coupling agents, etc., may be added as needed and compounded by known methods such as kneading. The composite can then be molded into pellets, films, or other forms depending on the application.

[0048] Furthermore, when manufacturing the resin composite composition, other inorganic fillers may be added in addition to the spherical silica particles and resin. Examples of such inorganic fillers include amorphous or crystalline silica particles other than the spherical silica particles mentioned above, alumina particles, titania particles, magnesia particles, aluminum nitride particles, boron nitride particles, barium titanate particles, calcium titanate particles, and carbon fiber. The blending ratio of the inorganic fillers can be appropriately adjusted depending on the application of the resin composite composition, but from the viewpoint of exhibiting the effect of the spherical silica particles included in one embodiment of the present invention, it is preferable that (weight of spherical silica particles):(weight of other inorganic fillers) = 95:5 to 60:40.

[0049] Furthermore, when curing the resin composite composition to produce a resin composite, for example, the resin composite composition can be heated and melted, processed into a shape suitable for the application, and then completely cured by applying a higher heat than that used during melting. In this case, known methods such as the transfer molding method or the compression molding method can be used.

[0050] For example, when manufacturing semiconductor-related materials such as packaging substrates and interlayer insulating films, known resins can be used as the resin in the resin composite composition, but epoxy resins are preferred. The epoxy resin is not particularly limited, but for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthalene type epoxy resin, phenoxy type epoxy resin, etc., can be used. One of these can be used alone, or two or more with different molecular weights can be used in combination. Among these, epoxy resins having two or more epoxy groups in one molecule are preferred from the viewpoint of curability, heat resistance, etc. Specifically, examples include biphenyl-type epoxy resins, phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, epoxidized novolac resins of phenols and aldehydes, glycidyl ethers such as bisphenol A, bisphenol F, and bisphenol S, glycidyl ester epoxy resins obtained by the reaction of polybasic acids such as phthalic acid and dimer acid with epochlorohydrin, linear aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, alkyl-modified polyfunctional epoxy resins, β-naphthol novolac-type epoxy resins, 1,6-dihydroxynaphthalene-type epoxy resins, 2,7-dihydroxynaphthalene-type epoxy resins, bishydroxybiphenyl-type epoxy resins, and epoxy resins into which halogens such as bromine have been introduced to impart flame retardancy. Among these epoxy resins having two or more epoxy groups in one molecule, bisphenol A-type epoxy resins are particularly preferred.

[0051] Furthermore, resins other than epoxy resins can be used in applications other than composite materials for semiconductor encapsulants, such as prepregs for printed circuit boards and various engineering plastics. Specifically, in addition to epoxy resins, other resins include silicone resins, phenolic resins, melamine resins, urea resins, unsaturated polyesters, fluororesins, polyimides, polyamide-imides, polyetherimides and other polyamides; polyesters such as polybutylene terephthalate and polyethylene terephthalate; polyphenylene sulfide, aromatic polyesters, polysulfones, liquid crystal polymers, polyethersulfones, polycarbonates, maleimide-modified resins, ABS resins, AAS (acrylonitrile-acrylic rubber-styrene) resins, and AES (acrylonitrile-ethylene-propylene-diene rubber-styrene) resins.

[0052] As a curing agent used in a resin composite composition, any known curing agent can be used to cure the resin. For example, a phenolic curing agent can be used. As phenolic curing agents, phenol novolac resins, alkylphenol novolac resins, polyvinylphenols, etc., can be used individually or in combination of two or more. In addition, from the viewpoint of reducing water absorption, an active ester curing agent can be used. As an active ester curing agent, compounds having two or more highly reactive ester groups in one molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, can be preferably used.

[0053] The amount of curing agent blended is preferably such that its equivalent ratio (hydroxyl group equivalent / epoxy group equivalent) with the epoxy resin is 0.1 or more and less than 1.0. This eliminates the residue of unreacted curing agent, improving moisture absorption, heat resistance, and water absorption properties.

[0054] The amount of spherical silica particles added to the resin composite composition is preferably high from the viewpoint of heat resistance and thermal expansion coefficient, but is usually appropriate to be 50% to 95% by mass, preferably 60% to 90% by mass, and more preferably 65% ​​to 85% by mass. This is because if the amount of spherical silica particles is too low, it is difficult to obtain effects such as improving the strength of the sealing material and suppressing thermal expansion, and conversely, if it is too high, segregation due to aggregation of spherical silica particles is likely to occur in the composite material regardless of the surface treatment of the spherical silica particles, and the viscosity of the composite material becomes too high, which can make it difficult to use as a sealing material. When the aforementioned "other fillers" are used in combination, the preferred amount added to the resin composite composition is the total amount of spherical alumina particles and "other fillers".

[0055] One embodiment of the present invention is a method for producing spherical silica particles contained in a slurry composition, which may include a step of melting natural silica in a flame and then cooling it to form spherical particles, and a step of classifying the particles after the spheroidizing step using a classifier (e.g., a precision wind classifier) ​​and / or a sieve. This method can produce spherical silica particles with an average particle diameter of 0.1 to 3.0 μm. Furthermore, the specific surface area and circularity measured by the BET method can be adjusted as appropriate. [Examples]

[0056] The present invention will be described through the following examples and comparative examples. However, the present invention is not limited to the following examples.

[0057] <Manufacturing of spherical silica particles> Natural silica was crushed, and the crushed material was fed into a high-temperature flame formed by the combustion of LPG and oxygen to undergo melting and spheroidization treatment to obtain spherical silica particles. Spherical silica particles A to K shown in Table 1 were produced by adjusting the flame formation conditions, raw material particle size, raw material supply amount, classification conditions, and mixing conditions. Specifically, the particle size distribution was adjusted by adjusting the raw material particle size and by multi-stage sieving and classification operations of the powder after spheroidization treatment, and as a final step, classification was performed using a precision wind classifier. The average particle size measured by a dynamic light scattering particle size distribution analyzer and the specific surface area measured by the BET method were adjusted by adjusting the mixing amounts of several types of powders obtained in the above operations. For example, the average particle size was adjusted by mixing particles with known average particle sizes in appropriate proportions, and the specific surface area was adjusted by adding ultrafine powders with various particle sizes and specific surface areas.

[0058] The following physical properties of the obtained spherical silica particles were measured according to the procedure described below.

[0059] [Average particle diameter of spherical silica particles] The particle size distribution was measured using a dynamic light scattering particle size analyzer (ZETASIZER NANO, Malvern). Spherical silica particles listed in Table 1 were placed in a polypropylene container with MEK to a concentration of 0.1 volume% to prepare a silica dispersion. The silica dispersion was adjusted to a volume of 20 mL. Then, 31 g of zirconia beads (media diameter: 2 mm) were added to the polypropylene container and stirred for 1 minute using a rotary-orbiting stirrer (SK-350G, Photo Chemical Co., Ltd.) at a rotational speed of 800 rpm and a rotational speed of 622 rpm. The treated silica dispersion was placed in a glass cell, and the average particle size was measured with the refractive index of the solvent set to 1.38 and the refractive index of amorphous silica set to 1.46. The results are shown in Table 1.

[0060] [Specific surface area of ​​spherical silica particles] The specific surface area (BET value) was determined using a surface area analyzer (Mountec, MacSorp Model HM-1208) by applying the BET theory to the adsorption isotherms measured by the gas adsorption method. The results are shown in Table 1.

[0061] [Table 1]

[0062] <Manufacturing of spherical silica particles> Spherical silica particles were added to the dispersion medium to obtain a slurry composition with the specifications listed in Table 2.

[0063] [Settling velocity of spherical silica particles in slurry composition] The obtained slurry composition was filled into the measurement cell of a centrifugal sedimentation analyzer (LUMiSizer, manufactured by LUM Japan) either in its original state or after being adjusted to a predetermined concentration. The sedimentation velocity was measured under the following conditions: rotation speed: 2,000 rpm, number of profiles: 1,000, measurement interval: 10 seconds, light intensity LF1. The sedimentation velocity distribution and average sedimentation velocity were calculated from the obtained sedimentation profiles using dedicated software. The results are shown in Table 2.

[0064] <Manufacturing of resin composite compositions> By adding a matrix resin to the slurry composition and mixing it uniformly, a resin composite composition with the specifications listed in Table 2 was obtained.

[0065] Furthermore, epoxy resin or polyimide was used as the matrix resin. Epoxy resin was added to the slurry composition and mixed to obtain a resin composite composition. Polyimide was prepared as a varnish according to the following procedure, then added to the slurry composition and mixed to obtain a resin composite composition.

[0066] <Preparation of polyimide varnish> A 500 mL four-necked flask equipped with a nitrogen inlet tube, stirrer, thermocouple, Dean-Stark trap, and condenser was charged with 38.45 g of BTDA (0.119 mol), 31.50 g of DDA (0.059 mol), 20.47 g of BAFL (0.059 mol), 127 g of NMP, and 84 g of xylene. The mixture was stirred at 40°C for 30 minutes to prepare a polyamic acid solution. This polyamic acid solution was heated to 180°C and stirred for 4 hours, and the distilled water and xylene were removed from the system. The mixture was then cooled to 100°C, 51 g of xylene was added and stirred, and the mixture was further cooled to 30°C to complete the imidation process and prepare a soluble polyimide varnish (1) (solid content: 31.0 wt%, weight-average molecular weight: 70,086).

[0067] [Number of aggregated particles in the resin composite composition] The obtained resin composite composition was uniformly applied to a thickness of 40 μm, and the number of visible aggregates (aggregates of spherical silica particles) present in a 20 cm × 30 cm area was counted. The results are shown in Table 2.

[0068] <Manufacturing of copper-clad laminates> A copper-clad laminate was manufactured to evaluate the adhesion between the matrix resin and spherical silica particles in a resin composite composition. The copper-clad laminate was obtained by coating the resin composite composition obtained above onto copper foil (1) and drying it. Detailed manufacturing conditions are described below.

[0069] (Example 1) 54 parts by mass of spherical silica particles A and 46 parts by mass of MEK were placed in a polypropylene container and stirred for 2 minutes using a rotary-rotating stirrer (Shinsha Kagaku Co., Ltd. SK-350G) at a rotational speed of 1,340 rpm and a rotational speed of 1,060 rpm. Then, zirconia beads (media diameter: 2 mm) were added to the polypropylene container and stirred for 5 minutes using the rotary-rotating stirrer (Shinsha Kagaku Co., Ltd. SK-350G) at a rotational speed of 800 rpm and a rotational speed of 622 rpm. After stirring, the zirconia beads were filtered to obtain slurry composition 1.

[0070] 66 parts by mass of slurry composition 1, 3.7 parts by mass of ESN-475V, 3.7 parts by mass of ZX-1059, 3.5 parts by mass of BRG-557, 0.15 parts by mass of DMAP, and 3.5 parts by mass of YP-50S were weighed and placed in a polypropylene container. The mixture was then stirred twice for 2 minutes each time using a rotary-rotating agitator (SK-350G, Photo Chemical Co., Ltd.) at a rotational speed of 1,340 rpm and a rotational speed of 1,060 rpm to obtain resin composite composition 1 (epoxy resin). Details of the raw material samples (ESN-475V, etc.) mentioned above will be explained in detail later. The obtained resin composite composition 1 (epoxy resin) was coated onto copper foil (1) to a thickness of 50 μm, and then dried in a hot air oven at 100°C for 5 minutes to obtain a single-sided copper-clad laminate 1 (epoxy resin).

[0071] Furthermore, 30 parts by mass of slurry composition 1 and 21.5 parts by mass of soluble polyimide varnish (1) were weighed and placed in a polypropylene container. The mixture was then stirred twice for 2 minutes each time using a rotary-rotating agitator (Shashin Kagaku Co., Ltd. SK-350G) under conditions of rotation at 1,340 rpm and rotation at 1,060 rpm to obtain resin composite composition 1 (polyimide resin). The obtained resin composite composition 1 (polyimide resin) was then coated onto copper foil (1) to a thickness of 50 μm, and dried in a hot air oven at 100°C for 5 minutes to obtain a single-sided copper-clad laminate 1 (polyimide resin).

[0072] (Examples 2-12, Comparative Examples 1-6) Slurry compositions 2-17, resin composite compositions 2-17, and single-sided copper-clad laminates 2-17 were prepared in the same manner as in Example 1, except that the amounts of spherical silica particles, MEK, slurry composition, matrix resin, etc., were changed as shown in Table 2.

[0073] [Evaluation of adhesion of spherical silica particles in resin composite compositions] Adhesive tape with an adhesive strength of 0.23 kN / m was applied to the resin side of a single-sided copper-clad laminate and peeled off to evaluate the detachment of spherical silica particles. A × indicated that almost the entire area of ​​the adhesive tape peeled off, a △ indicated that only a portion peeled off, and a ○ indicated that no peeling occurred. The evaluation results are shown in Table 2. Adhesive strength 0.23kN / m: 3M (trademark) ultra-high molecular weight polyethylene tape; 5360T; manufactured by 3M Company.

[0074] [Table 2]

[0075] [Table 3]

[0076] [Table 4]

[0077] [Table 5]

[0078] [Table 6]

[0079] [Table 7]

[0080] <Regarding raw material samples> The raw material samples used in the preparation of slurry compositions, resin composite compositions, and double-sided copper-clad laminates are shown below. Spherical silica particles: Spherical silica particles manufactured by thermal spraying. MEK: Methyl ethyl ketone Epoxy resin: ESN-475V Epoxy resin: ZX-1059 Epoxy resin hardener: BRG-557 Phenoxy resin: YP-50S Curing accelerator: DMAP (4-dimethylaminopyridine) NMP:N-methyl-2-pyrrolidone xylene BTDA:3,3',4,4'-benzophenonetetracarboxylic dianhydride BAFL: 9,9-bis(4-aminophenyl)fluorene DDA: A 36-carbon aliphatic diamine (manufactured by Croda Japan Co., Ltd., trade name: PRIAMINE1074, amine value: 205 mg KOH / g, mixture of cyclic and chain-structured dimer amines, dimer component content: 95% by weight or more) Copper foil (1): CF-T9DA-SV-12: Manufactured by Fukuda Metal Foil and Powder Industries Co., Ltd.

[0081] Examples 1 to 12 all demonstrated good adhesion and excellent dispersion stability, with average sedimentation velocities ranging from 0.1 to 20.0 μm / sec. Comparative Example 1 has a spherical silica particle concentration of 40 wt%, and its average sedimentation velocity exceeds 20.0 μm / sec, indicating poor dispersion stability. Comparative Examples 2 and 3 had average sedimentation velocities exceeding 20.0 μm / sec, indicating poor dispersion stability, and in addition, their adhesion to epoxy resin composite compositions was poor. Comparative Examples 4 and 5 have a specific surface area of ​​18.4 m² for spherical silica particles. 2 The concentration was above / g, and the adhesion when used as an epoxy resin composite composition was poor (×). Comparative Example 6 had a spherical silica particle concentration of 78 wt%, resulting in a high viscosity of the slurry, which made it impossible to perform measurements and other operations.

Claims

1. A slurry composition comprising spherical silica particles and a dispersion medium, The specific surface area of ​​the aforementioned spherical silica particles is 18.4 m². ２ It is less than, A slurry composition characterized in that the average settling velocity of the spherical silica particles measured at a concentration of 45 to 75 wt% is 0.1 to 20.0 μm / sec, and the value of the following formula (1) is greater than 3.0 and less than or equal to 20.

0. Equation (1) Average particle diameter of spherical silica particles (μm) × Specific surface area of ​​spherical silica particles (m²) ２ / g)

2. The slurry composition according to claim 1, wherein the value of formula (1) is 3.21 or more and less than 6.

27.

3. The slurry composition according to claim 1, wherein the spherical silica particles have an average particle diameter (D50) of 0.1 μm or more and 3.0 μm or less as determined by laser diffraction scattering.

4. The slurry composition according to claim 1, wherein the circularity of the spherical silica particles is 0.85 or greater.

5. The slurry composition according to claim 1, wherein, of the spherical silica particles, if the number of particles between 1 μm and 30 μm detected by a Coulter counter is A for the number of particles between 1 and 2 μm and B for the number of particles between 2 and 30 μm, then B / A is 0.002 or more and 0.20 or less.

6. The slurry composition according to claim 1, wherein, of the spherical silica particles, among the particles of 1 μm to 30 μm detected by a Coulter counter, the number of particles of 10 μm or larger is less than 10 ppm.

7. The slurry composition according to claim 1, wherein the relative permittivity of the dispersion medium is 5 to 30.

8. A resin composite composition comprising the slurry composition according to any one of claims 1 to 7.

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