Slurry composition

Abstract

To provide a slurry composition which includes spherical silica particles excellent in flowability in a narrow space.SOLUTION: A slurry composition contains spherical silica particles in which, of particles having 1 μm or more and 30 μm or less as detected by a Coulter counter, the frequency in number of the particles having 3 μm or more is 300 ppm or more and 50000 ppm or less and the frequency in number of the particles having 5 μm or more is 100 ppm or less and which have a specific surface area measured by a BET method of 5.0 m2 / g or more and 20.0 m2 / g or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a slurry composition comprising spherical silica particles dispersed in a dispersion medium, in particular, a slurry composition in which, among particles having a size of 1 μm or more and 30 μm or less as detected by a Coulter counter, the number frequency of particles having a size of 3 μm or more is 300 ppm or more and 50,000 ppm or less, and the number frequency of particles having a size of 5 μm or more is 100 ppm or less, and the specific surface area measured by the BET method is 5.0 m 2 / g or more 20m 2 The present invention relates to a slurry composition in which spherical silica particles having excellent fluidity due to a viscosity of 1 / g or less are dispersed in a dispersion medium. [Background technology]

[0002] In recent years, semiconductor packages used in electronic components, communication devices, and other devices have become increasingly smaller and thinner. This has led to a growing need for finer substrate materials, such as semiconductor encapsulants and insulating layers for package substrates. To enhance mechanical strength and reduce warpage, these semiconductor components typically use resin compositions containing fillers to control their linear expansion coefficient. Methods for producing such resin compositions include kneading dried filler with a matrix resin using a kneader or a three-roll mill. Other methods include dispersing the filler 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 containing the filler dispersed in the resin material (see Patent Document 4). This method offers advantages over direct kneading of the filler and resin, such as the ability to uniformly disperse the filler in the resin material.

[0003] As described above, the slurry composition or filler used in semiconductor peripheral components has been investigated from various viewpoints such as fluidity, packing property, and dispersibility.

[0004] For example, Patent Document 1 proposes that in order to obtain high fluidity of a resin composite composition as described above, the particle size distribution and specific surface area of ​​the amorphous silica powder contained in the resin composite composition be appropriately adjusted. More specifically, in the particle size frequency distribution, the most frequent diameter is in the range of 1 to 10 μm, the frequency of particles with a particle size of less than 0.50 μm is 1.0% or more, and the frequency of particles with a particle size of 1 to 12 μm is 1.0% or more. 2 The present invention discloses an amorphous silica powder characterized by having a specific surface area of ​​1000 nm / g.

[0005] Furthermore, Patent Document 2 relates to a method for producing spherical inorganic fine powder by thermally spraying raw material powder into a flame to make it spherical, and proposes a method for preventing the resulting powder (particles) from becoming coarse and achieving a particle size within a desired range. More specifically, it discloses that by mixing a dispersion surface treatment agent with inorganic raw material powder of a specific average particle size and then thermally spraying it, it is possible to prevent particle size increase during thermal spraying due to aggregation of the raw material powder.

[0006] Furthermore, Patent Document 3 discloses a spherical silica powder that includes a step of forming spherical silica particles by a sol-gel method, firing the spherical silica particles, and then crushing the fired particles.

[0007] However, further improvements in the properties of resin composite compositions or inorganic particle-containing slurry compositions used in semiconductor peripheral components are required. In particular, with the recent trend toward miniaturization of semiconductor packages, there is a demand for smaller particle sizes of fillers used in semiconductor encapsulants and substrate materials. On the other hand, the smaller particle sizes have led to problems such as reduced fluidity of the slurry composition, which in turn has led to poor workability and performance degradation of the resin composition. Specifically, there have been problems such as reduced permeability in narrow spaces, such as glass cloth, and poor dispersion of the filler in the resin composition. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-037681 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-015884 [Patent Document 3] Japanese Patent Application Publication No. 2022-90679 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-285003 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a slurry composition containing spherical silica particles that has excellent fluidity in a narrow space. [Means for solving the problem]

[0010] The present inventors have found that the above-mentioned problems can be solved by precisely cutting out coarse particles in the particle size distribution of the spherical silica particles contained in the slurry, more specifically by limiting the number of coarse particles having a specific particle size or larger.

[0011] Based on the above findings, the gist of the present invention is as follows.

[0012] [1] A slurry composition comprising spherical silica particles and a dispersion medium, wherein the spherical silica particles have a particle size of 1 μm or more and 30 μm or less, and a particle size of 3 μm or more, the particle size being detected by a Coulter counter, and the particle size being 300 ppm or more and 50,000 ppm or less, and the particle size being 5 μm or more, the particle size being 100 ppm or less, and the specific surface area measured by the BET method is 5.0 m 2 / g or more 20.0m 2 / g or less. [2] The slurry composition according to [1], wherein the spherical silica particles are surface-treated with a silane coupling agent. [3] The slurry composition according to [1] or [2], wherein the spherical silica particles have a D50 measured by a laser diffraction scattering method of 0.4 μm or more and 3.0 μm or less. [4] The slurry composition according to any one of [1] to [3], wherein the spherical silica particles have a circularity of 0.85 or more. [5] The slurry composition according to any one of [1] to [4], wherein, among the number of particles of 1 μm or more and 30 μm or less detected by a Coulter counter, the spherical silica particles have a particle number frequency of 1 to 2 μm as A and a particle number frequency of 2 to 30 μm as B, where 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 the spherical silica particles have less than 10 ppm of particles having a size of 1 μm or more and 30 μm or less as detected by a Coulter counter. [7] The slurry composition according to any one of [1] to [6], wherein when a glass cloth having a thickness of 0.09 mm and an 8 cm square is immersed in 5 mL of the slurry for 30 seconds, pulled out, and dried at 180°C for 1 hour, the weight of the glass cloth increases by 0.1 g or more. [8] The slurry composition according to any one of [1] to [7], further comprising at least one inorganic filler selected from amorphous spherical silica particles, crystalline spherical silica particles, alumina particles, titania particles, magnesia particles, aluminum nitride particles, boron nitride particles, barium titanate particles, calcium titanate particles, and carbon fibers. [9] The slurry composition according to any one of [1] to [8], wherein the dispersion medium has a relative dielectric constant of 5 to 30. [Effects of the Invention]

[0013] The spherical silica particle-containing slurry composition and the resin composite composition prepared using the same according to the present invention have a particle size distribution of the spherical silica particles, particularly the number frequency of particles 3 μm or larger and the number frequency of particles 5 μm or larger, controlled within specific ranges. Therefore, the slurry composition does not contain coarse particles and has excellent fluidity and permeability in narrow spaces. As a result, the defect rate can be reduced in recent small or thin semiconductor products or circuit board insulating layers. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of a mold for measuring fluidity. DETAILED DESCRIPTION OF THE INVENTION

[0015] The spherical silica particles constituting the slurry composition of the present invention are Among particles between 1 μm and 30 μm detected by a Coulter counter, the number frequency of particles 3 μm or larger is between 300 ppm and 50,000 ppm, the number frequency of particles 5 μm or larger is 100 ppm or smaller, and the specific surface area measured by the BET method is 5.0 m 2 / g or more 20.0m 2 / g or less.

[0016] The Coulter Counter measures particles using an electrical resistance method known as the Coulter Principle, and is free from errors in particle surface morphology, internal structure, refractive index, color, etc., which can be seen in optical measurement methods, resulting in high measurement accuracy. In particular, the particle size obtained by this method can be expressed as a number distribution, making it possible to precisely control the particle size distribution.

[0017] 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 (Ultra Sonic Homogenizer UH-300, manufactured by SMT Corporation). This dispersion was then added to the electrolyte prepared in another beaker to adjust the concentration. The particle size of each spherical silica particle in the adjusted dispersion was measured using a Coulter counter (Multisizer 3, manufactured by Beckman Coulter) with an aperture diameter of 50 μm. The number of particles measured per measurement was approximately 100,000, and the same sample was measured three times. Of the particles between 1 μm and 30 μm in size detected by the Coulter counter, the number of particles with diameters of 3, 5, and 10 μm or larger was calculated, and this was used as the frequency (ppm) of coarse particles relative to the total number measured.

[0018] Measurement using this Coulter counter reveals that the number frequency of particles 3 μm or larger relative to the total number of spherical silica particles 1 μm or larger and 30 μm or smaller is 300 ppm or larger and 50,000 ppm or smaller, and the number frequency (proportion) of coarse particles 5 μm or larger is 100 ppm or smaller. For example, 100 ppm or smaller means that, out of 100,000 particles 1 μm or larger and 30 μm or smaller, there are 10 or fewer particles 5 μm or larger. The present inventors have found that if the number frequency of coarse particles 5 μm or larger exceeds 100 ppm, such coarse particles clog the narrow spaces between the mounting substrate and the chip, reducing fluidity, and as a result, reducing the defect rate of semiconductor products filled with the particles.

[0019] The lower the number frequency of coarse particles of 5 μm or more, the better the fluidity, so this number frequency may be 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, or 50 ppm or less. The number frequency of coarse particles of 5 μm or more may be 0 ppm, but completely eliminating these coarse particles, i.e., achieving 0 ppm, can be difficult due to the large burden on manufacturing management, so it may be set to several ppm, specifically 1 ppm or more, or 5 ppm or more. The lower limit of this number frequency may be adjusted depending on the actual application and the tolerance range of the target yield, for example, it may be set to 10 ppm or more, 20 ppm or more, or 30 ppm or more.

[0020] On the other hand, the number frequency of coarse particles of 3 μm or more needs to be controlled to ensure the fluidity of the resin composite composition. If the number frequency is less than 300 ppm, the number of particles with a large specific surface area of ​​less than 3 μm increases, resulting in increased viscosity and reduced fluidity. On the other hand, if the number frequency exceeds 50,000 ppm, it becomes difficult to prevent the inclusion of particles of 5 μm or more, causing clogging in the narrow space between the mounting substrate and the chip, resulting in reduced fluidity. The preferred upper limit of the number frequency is 30,000 ppm, more preferably 20,000 ppm. The preferred lower limit of the number frequency is 500 ppm, more preferably 1,000 ppm, and even more preferably 2,000 ppm.

[0021] Furthermore, among particles of 1 μm to 30 μm in size detected by a Coulter counter, the number frequency of particles of 10 μm or larger is preferably less than 10 ppm. The lower the number frequency of coarse particles of 10 μm or larger, the better the fluidity, and therefore it is preferable. If the number frequency of coarse particles of 10 μm or larger is 10 ppm or higher, such coarse particles will clog the narrow spaces 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.

[0022] Furthermore, among the number of particles measuring 1 μm to 30 μm in size as detected by a Coulter counter, if the frequency of 1-2 μm particles is A and the frequency of 2-30 μm particles is B, the ratio B / A is preferably 0.002 to 0.20. This means that it is preferable to contain an excess of 1-2 μm particles relative to the 2-30 μm particles, but if there are too many 1-2 μm particles with large surface areas, fluidity may be impaired. By setting the ratio within this range, the fluidity of the resin composite composition is appropriately ensured and the filling (blending) effect of the filler is fully exhibited. The lower limit of B / A is more preferably 0.01, more preferably 0.03, more preferably 0.05, and even more preferably 0.10. On the other hand, the upper limit of B / A is more preferably 0.19.

[0023] The spherical silica particles used in the slurry composition of the present invention exhibit the effects of the invention regardless of the crystallinity. However, since amorphous silica has a lower thermal expansion coefficient than crystalline silica, in order to more effectively reduce the thermal expansion coefficient of the resin composition, the crystallinity is preferably 20% or less, more preferably 10% or less, even more preferably 5% or less, even more preferably 1% or less, and even more preferably 0.1% or less. Here, "crystallinity" refers to the ratio of amorphous to crystalline silica in spherical silica particles. Crystallinity can be determined by XRD. When measuring with XRD, the ratio of the crystalline phase can be calculated using the following formula from the sum of the integrated intensities of the crystalline peaks (Ic) and the integrated intensity of the amorphous halo (Ia). X (crystal phase ratio) = Ic / (Ic+Ia) × 100 (%) In the present invention, XRD measurements were performed in the range of 2Θ = 10° to 90°. The crystalline phase ratio was determined from the sum of the crystalline peak intensities appearing in the 2Θ measurement range and the integrated intensity of the broad halo portion caused by amorphous matter appearing around 2Θ = 22°. In the present invention, an X-ray diffraction device "D2 PHASER" (manufactured by Bruker) was used.

[0024] The spherical silica particles used in the slurry composition of the present invention can be produced by methods such as thermal spraying. In this method, natural silica powder, which has been pulverized to a desired particle size, is passed through a flame, where the particles melt and become spherical due to surface tension. This thermal spraying method can produce spherical silica particles with a circularity of 0.80 or more, preferably 0.85 or more. They can also be produced by burning metals. For example, a mixture of metal powders, such as silicon powder, is mixed with a carrier gas to form a chemical flame in an oxygen-containing atmosphere, and the desired silica (SiO2) microparticles are obtained in this chemical flame. The crystallinity can be controlled by the conditions of heat treatment (particle melting, cooling, etc.) during the spherical silica particle production process.

[0025] Classification may be performed to obtain spherical silica particles with a desired particle size distribution. Classification can be performed using a conventionally known method, including either wet classification or dry classification. Gravitational field classification, inertial field classification, or centrifugal field classification may also be used. In the case of centrifugal field classification, either a free vortex type or a forced vortex type may be used. A preferred example is a method using a precision air classifier (also called an "air classifier") to separate the coarse and fine particles. However, in the present invention, the number frequency is measured using a Coulter counter for classification control, and precise control of the particle size distribution contributes to the excellent properties of the slurry composition of the present invention, such as fluidity in a narrow space.

[0026] The spherical silica particles may be mixed with other inorganic fillers to the extent that desired properties are obtained. Here, other inorganic fillers include those of different types, such as alumina powder, magnesia powder, titania powder, etc., as well as those with different particle size distributions. The types of other inorganic fillers will be described later.

[0027] In one embodiment of the present invention, the spherical silica particles may have a D50 of 0.4 μm or more and 3.0 μm or less as measured by a laser diffraction scattering method.

[0028] The particle size distribution of spherical silica particles can also be measured by laser diffraction scattering, using a particle size distribution analyzer such as the "Mastersizer 3000" (Malvern). For the measurement, the refractive index of the water solvent is set to 1.33, and the refractive index of the powder is determined by taking into account the refractive index of the powder material. For example, the refractive index of amorphous silica is set to 1.54.

[0029] D50 (median diameter) is the particle diameter at which the cumulative volume is 50% in the cumulative particle size distribution of spherical silica particles. D100 (maximum particle diameter) is the particle diameter at which the cumulative volume is 100% in the cumulative particle size distribution of spherical silica particles.

[0030] If D50 is less than 0.4 μm, the particle size is small, and the viscosity of a slurry composition containing the particles and an encapsulant, which is a type of resin composite composition, using the same may be too high. On the other hand, if D50 is more than 3.0 μm, problems may occur in which particles settle during storage, filling, or curing of the slurry or encapsulant, or the inclusion of large amounts of particles 5 μm or larger may cause particles to get caught in the narrow spaces between the mounting substrate and the chip, resulting in poor fluidity of the encapsulant and reduced moldability. A more preferred lower limit is 1.0 μm. On the other hand, a more preferred upper limit is 2.0 μm.

[0031] The spherical silica particles used in the slurry composition of the present invention have a specific surface area of ​​5.0 m2 as measured by the BET method. 2 / g or more 20.0m 2 / g or less.

[0032] The specific surface area of ​​the spherical silica particles can also be measured by the BET method, using a specific surface area measuring device manufactured by Mountech Co., Ltd., under the trade name "Macsorb Model HM-1208."

[0033] The specific surface area of ​​spherical silica particles is 5.0m 2If the specific surface area is less than 7.9 m / g, the particles will be less likely to form a close-packed structure, which may reduce the fluidity of the slurry composition of the present invention or the sealing material containing the slurry composition. 2 / g or more, and 2 On the other hand, the specific surface area of ​​the spherical silica particles may be 20.0 m / g or more. 2 If the specific surface area is more than 17.0 m / g, the tendency for particles to aggregate increases, which may also reduce the fluidity of the slurry composition or the sealing material. 2 / g or less, and 2 / g or less.

[0034] In one embodiment of the present invention, the spherical silica particles may have a circularity of 0.85 or more. The higher the circularity of the spherical silica particles, the lower the viscosity of the resin composite composition containing the particles and the more improved the moldability. The circularity may be 0.90 or more, or 0.93 or more. Theoretically, the upper limit of the circularity is 1.0, but from the viewpoint of production control, it may be 0.98 or less, or 0.95 or less.

[0035] Circularity can be measured using an electron microscope or optical microscope and an image analyzer, 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 of 100 or more particles is measured, and the average value is taken as the circularity of the powder.

[0036] <Dispersion medium> The dispersion medium used in the slurry composition of the present invention preferably has a dielectric constant in the range of 5 to 30, with more preferred lower limits of the dielectric constant being 8, 10, or 12, and more preferred upper limits being 25 or 20. Using a dispersion medium with a dielectric constant in the above ranges allows for a slurry composition with high affinity between the spherical silica particles and the dispersion medium, excellent fluidity in a narrow space, and excellent dispersion stability. Examples of suitable dispersion mediums include cyclohexanone (dielectric constant: 18.3 (20°C)), methyl ethyl ketone (dielectric constant: 18.5 (20°C)), acetone (dielectric constant: 20.7), methyl isobutyl ketone (dielectric constant: 13.1 (20°C)), tetrahydrofuran (dielectric constant: 7.6 (25°C)), ethanol (dielectric constant: 24.6 (25°C)), cyclohexane (dielectric constant: 20.1 (20°C)), and 2-propanol (dielectric constant: 19.9 (25°C)).

[0037] <Method of preparing slurry> The slurry composition of the present invention can be prepared by dispersing the powder of the spherical silica particles by a known dispersion method, specifically, using equipment such as a triple roll mill, a bead mill, a ball mill, an ultrasonic disperser, various mixers, a kneader, or a high-pressure wet atomizer.

[0038] The content of spherical silica particles in the slurry composition is preferably 30 to 95 wt%. If the filler content is less than 30 wt%, the viscosity of the slurry composition will be low and the settling stability of the filler in the slurry composition will be low, which is undesirable. If the content of spherical silica particles is more than 95 wt%, the viscosity will be high and the flowability will be impaired.

[0039] <Surface treatment of spherical silica particles> The spherical silica particles contained in the slurry composition of the present invention are preferably treated with a silane compound, such as a compound having at least one functional group selected from alkyl groups such as methyl, ethyl, propyl, and butyl, alkenyl groups such as vinyl, ethenyl, and propenyl, phenyl, amino, phenylamino, acrylic, methacrylic, epoxy, and styryl groups, a silane coupling agent, or a silazane. 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 a silane compound improves the affinity between the filler and the dispersion medium, thereby improving fluidity. In addition, for resin compositions produced using the slurry composition, improved adhesion to the matrix resin improves high loading properties, etc. The surface treatment method may be a method in which a filler-containing slurry composition of the present invention is prepared using a filler that has been previously subjected to the above treatment, or, depending on the surface treatment agent, a method in which the surface treatment is performed simultaneously with the preparation of the slurry composition. On the other hand, when the spherical silica particles are not surface-treated, the strength of the resin composition is excellent and the production flow is simple, which is preferable from the viewpoints of cost and production control.

[0040] <Dispersant> In addition to the silane compound, 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] The dispersant may be, for example, a dispersant containing at least one selected from a nonionic dispersant and a cationic dispersant. The nonionic dispersant is not particularly limited, and known dispersants can be used. Examples include polymeric compounds having a polyoxyethylene chain. Examples of polymeric compounds having a polyoxyethylene chain include alkyl polyoxyethylene ethers, alkyl polyoxyethylene-polyoxypropylene ethers, alkyl polyoxypropylene-polyoxyethylene ethers, polyoxyethylene-polyoxypropylene ethers (polyoxyethylene-polyoxypropylene 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), and acetylene glycol ethylene oxide adducts. Examples of alkyl polyoxyethylene ethers include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl ether, polyoxyethylene cetyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene nonylphenyl ether. Examples of fatty acid polyoxyethylene sorbitan esters include polyoxyethylene sorbitan monolaurate.

[0042] The cationic dispersant is not particularly limited, and known dispersants can be used. Examples include alkylamine salts, acylamine salts, quaternary ammonium salts, ammonium salts having an amide bond, an ester bond, or an ether bond, imidazoline, imidazolium salts, and amine derivatives. The cationic dispersant may be a low-molecular-weight compound or a high-molecular-weight compound, but high-molecular-weight compounds are preferred from the viewpoint of silica particle dispersibility. 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 an oxyethylene group-containing polymer compound. Examples of copolymers of vinylpyridine, (meth)acrylic acid, and an oxyethylene group-containing polymer compound include copolymers of vinylpyridine, (meth)acrylic acid, and polyoxyethylene. Among these, amine-type high-molecular-weight dispersants are preferred from the viewpoint of silica particle dispersibility.

[0043] The dispersant may be a known surface treatment agent, which can improve the dispersibility of the spherical silica particles in the dispersion medium in the slurry composition, the dispersibility or affinity of the spherical silica particles with the resin in the resin composite composition, and the dispersibility of the spherical silica particles in the cosmetic composition. Examples include compounds having at least one functional group selected from alkyl groups such as methyl, ethyl, propyl, and butyl, alkenyl groups such as vinyl, ethenyl, and propenyl, phenyl, amino, phenylamino, acrylic, methacrylic, epoxy, and styryl groups, silane coupling agents, and silazanes. More preferred are silane coupling agents having SiH, SiOH, and SiOR (R is a hydrocarbon group) and silazane containing hexamethylenedisilazane. 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 excellent reactivity, silazane compounds are more preferred. Hexamethyldisilazane and trimethylsilane are more preferred.

[0044] The content of spherical silica in the slurry composition (when the slurry composition contains an "inorganic filler" or "other fillers" described below, the total content of these) can be adjusted appropriately depending on the intended use of the slurry composition. Typically, the content is 50 to 95 wt% from the viewpoint of exerting the effects of the spherical silica particles. 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] <Dispersion in matrix resin and molding of molded product> The slurry composition of the present invention is used to disperse a filler in a matrix resin when molding a resin composite composition. Specifically, a matrix resin is added to the slurry composition and mixed uniformly. The dispersion medium is then removed by heating or other treatment to prepare a resin composite composition in which the filler is uniformly dispersed in the resin.

[0046] When producing the resin composite composition, for example, in addition to the spherical silica particles and the matrix resin, a curing agent, a curing accelerator, a flame retardant, a silane coupling agent, etc. may be blended as needed, and the resulting composite may be formed by a known method such as kneading, etc. Then, the composite may be molded into pellets, films, etc. depending on the intended use.

[0047] In addition, when producing the resin composite composition, other inorganic fillers may be blended in addition to the spherical silica particles and resin. Examples of the inorganic fillers include amorphous spherical silica particles, crystalline spherical silica particles, alumina particles, titania particles, magnesia particles, aluminum nitride particles, boron nitride particles, barium titanate particles, calcium titanate particles, and carbon fibers. The blending ratio of the inorganic fillers can be adjusted appropriately depending on the application of the resin composite composition, but from the viewpoint of exerting the effects of the spherical silica particles of the present invention, it is preferable that the blending ratio of the spherical silica particles to the other inorganic fillers is 95:5 to 60:40.

[0048] Furthermore, when the resin composite composition is cured to produce a resin composite, for example, the resin composite composition can be melted by applying heat, processed into a shape according to the intended use, and then completely cured by applying heat higher than that used for melting. In this case, known methods such as transfer molding and compression molding can be used.

[0049] For example, when manufacturing semiconductor-related materials such as package substrates and interlayer insulating films, known resins can be used as the resin for the resin composite composition, but epoxy resins are preferred. The epoxy resin is not particularly limited, but examples include bisphenol A epoxy resins, bisphenol F epoxy resins, biphenyl epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, naphthalene epoxy resins, and phenoxy epoxy resins. One of these resins can be used alone, or two or more resins with different molecular weights can be used in combination. Among these, epoxy resins having two or more epoxy groups per molecule are preferred from the standpoints of curability, heat resistance, and the like. Specific 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 of bisphenol A, bisphenol F, bisphenol S, etc., glycidyl ester acid epoxy resins obtained by reacting polybasic acids such as phthalic acid or dimer acid with epochlorohydrin, linear aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, alkyl-modified multifunctional 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 per molecule, bisphenol A-type epoxy resins are particularly preferred.

[0050] In addition, resins other than epoxy resins can also be used in resin composite compositions for applications other than semiconductor encapsulation composites, such as prepregs for printed circuit boards and various engineering plastics. Specific examples of resins that can be used in addition to epoxy resins include silicone resins, phenolic resins, melamine resins, urea resins, unsaturated polyesters, fluororesins, polyamides such as polyimides, polyamideimides, and polyetherimides; 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.

[0051] The curing agent used in the resin composite composition may be any known curing agent for curing the resin, such as a phenol-based curing agent, such as a phenol novolac resin, an alkylphenol novolac resin, or a polyvinylphenol, which may be used alone or in combination.

[0052] The amount of the phenolic curing agent blended is preferably such that the equivalent ratio to the epoxy resin (phenolic hydroxyl group equivalent / epoxy group equivalent) is 0.1 or more and less than 1.0, thereby eliminating any unreacted phenolic curing agent residue and improving moisture absorption and heat resistance.

[0053] The amount of spherical silica particles added to the resin composite composition is preferably large from the viewpoints of heat resistance and thermal expansion coefficient. Typically, it is 70% by mass to 95% by mass, preferably 80% by mass to 95% by mass, and more preferably 85% by mass to 95% by mass. This is because if the amount of spherical silica particles is too small, it is difficult to obtain the effects of improving the strength of the sealing material and suppressing thermal expansion. Conversely, if the amount is too large, segregation due to aggregation of the 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, making it difficult to use as a sealing material. When the aforementioned "other filler" is used in combination, the preferred amount added to the resin composite composition is the total amount of the spherical alumina particles and the "other filler."

[0054] A method for producing spherical silica particles contained in a slurry composition according to one embodiment of the present invention may include a step of introducing natural silica stone into a flame to melt it, followed by a step of cooling it to spheroidize it, and a step of classifying it using a classifier (e.g., a precision air classifier) ​​and / or a sieve after the spheroidization step. This production method can produce spherical silica particles having a particle size of 1 μm or more and 30 μm or less, a particle size of 3 μm or more being 300 ppm or more and 50,000 ppm or less, a particle size of 5 μm or more being 100 ppm or less, and a specific surface area of ​​5.0 m2 measured by the BET method. 2 / g or more 20.0m 2 It is possible to produce spherical silica particles with a density of 1 / g or less. [Example]

[0055] The present invention will be described below with reference to examples and comparative examples, but the present invention should not be construed as being limited to the following examples.

[0056] <Filler manufacturing method> Natural silica stone was crushed, and the crushed material was fed into a high-temperature flame formed by the combustion of LPG and oxygen, where it was melted and spheroidized to obtain spherical silica particles. The flame formation conditions, raw material particle size, raw material feed rate, classification conditions, and mixing conditions were adjusted to produce spherical silica particles A to E shown in Table 1. Specifically, the particle size distribution was adjusted by adjusting the raw material particle size and by subjecting the powder after the spheroidization treatment to multistage sieving and classification, with classification using a precision air classifier as the final step. The number frequencies of particles 3, 5, and 10 μm or larger among particles 1 μm to 30 μm in size detected by a Coulter counter, D50 (or mode diameter) by laser diffraction scattering, specific surface area and circularity measured by the BET method, the ratio B / A of the number frequencies measured by the Coulter counter (where A is the number frequency of particles 1 to 2 μm and B is the number frequency of particles 2 to 30 μm), and the number frequency of particles 10 μm or larger measured by a Coulter counter were adjusted by adjusting the amounts of the several powders obtained by the above procedures. For example, the number frequencies and their ratios were adjusted by mixing particles with known number frequencies in appropriate ratios, the specific surface area was adjusted by adding ultrafine powders with various particle sizes and specific surface areas, and the circularity was controlled by adjusting the flame formation conditions and the feed rate of the raw material.

[0057] Table 1 shows the physical properties of the spherical silica particles used.

[0058] [Table 1]

[0059] Method for producing a slurry composition Example 1 A slurry was prepared by dispersing 70 parts by mass of the spherical silica particles A obtained in the above step, 0.7 parts by mass of hexamethyldisilazane (HMDS) as a surface treatment agent, and 30 parts by mass of methyl ethyl ketone (MEK) as a dispersion medium using a disperser. Example 2 A slurry was prepared in the same manner as in Example 1, except that spherical silica particles B were used as the filler. Example 3 A slurry was prepared in the same manner as in Example 2, except that no surface treatment agent was added. Example 4 A slurry was prepared in the same manner as in Example 1, except that spherical silica particles B were used as a filler, no surface treatment agent was added, and ethanol was used as a dispersion medium. (Comparative Example 1) A slurry was prepared in the same manner as in Example 1, except that spherical silica particles C were used as the filler. (Comparative Example 2) A slurry was prepared in the same manner as in Comparative Example 1, except that no surface treatment agent was added. (Comparative Example 3) A slurry was prepared in the same manner as in Comparative Example 2, except that ethanol was used as the dispersion medium. Comparative Example 4 A slurry was prepared in the same manner as in Example 1, except that spherical silica particles D were used as the filler. (Comparative Example 5) A slurry was prepared in the same manner as in Example 1, except that spherical silica particles E were used as the filler.

[0060] [Table 2]

[0061] The methods for measuring the various physical properties are described below.

[0062] (Measured using the Coulter counter method) 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 (Ultra Sonic Homogenizer UH-300, manufactured by SMT Corporation). This dispersion was then added to the electrolyte solution prepared in another beaker to adjust the concentration. The particle size of each spherical silica particle was measured using a Coulter counter (Multisizer 3, manufactured by Beckman Coulter) with an aperture diameter of 50 μm. The number of particles measured per measurement was approximately 100,000, and the same sample was measured three times. The number of particles with particle sizes of 3, 5, and 10 μm or larger was calculated, and this was taken as the coarse particle frequency (ppm) for each particle relative to the total number measured. Similarly, the particle frequency A for particles with particle sizes of 1 to 2 μm and the particle frequency B for particles with particle sizes of 2 to 30 μm were also measured.

[0063] (D50 by laser diffraction scattering method) Measurements were made using a particle size distribution analyzer, "Mastersizer 3000" (Malvern). The refractive index of the solvent, water, was set to 1.33, and the refractive index of the powder was determined by taking into account the refractive index of the powder material. For example, amorphous silica was measured using a refractive index of 1.54.

[0064] (specific surface area) The specific surface area (BET value) was determined by applying the BET theory to the adsorption isotherm measured by the gas adsorption method (BET method). The specific surface area was measured using a Mountec Co., Ltd. product name "Macsorb Model HM-1208" specific surface area measuring device.

[0065] (Circularity) Circularity can be measured using an electron microscope or optical microscope and an image analyzer, 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 of 100 or more particles is measured, and the average value is taken as the circularity of the powder.

[0066] (Fluidity (Narrow area fluidity)) The length of the flow of the slurry composition containing spherical silica particles into the slit was measured using a mold for measuring fluidity in narrow sections, which had a slit with a groove width of 1 cm and a groove depth of 5 μm, as shown in Figure 1. The longer this length, the better the fluidity into the narrow section. A long length (2.5 cm or more) was marked ○ (Excellent), a length of 1.5 cm or more but less than 2.5 cm was marked △ (Good), and a short length (less than 1.5 cm) was marked × (Not Good).

[0067] (permeability) A 0.09mm thick, 8cm square glass cloth was immersed in 5mL of slurry for 30 seconds, then removed and dried at 180℃ for 1 hour. The greater the weight gain of the glass cloth after drying, the more filler it contained and the better its permeability. A weight change of 0.15g or more was evaluated as ○, 0.10g or more but less than 0.15g as △, and less than 0.10g as ×.

[0068] The above-mentioned fluidity (narrow section fluidity) and permeability were measured for the spherical silica particle slurry compositions of Examples 1 to 4 and Comparative Examples 1 to 5. The measurement results are shown in Table 2. It was confirmed that good fluidity, rated ○ (Excellent) or △ (Good), was obtained for the slurry compositions within the scope of the present invention. [Industrial Applicability]

[0069] The spherical silica particle slurry composition of the present invention and the resin composite composition containing the same exhibit good fluidity and can be used not only as a semiconductor encapsulation material but also for other applications, such as prepregs for printed circuit boards and various engineering plastics.

Claims

1. A slurry composition comprising spherical silica particles and a dispersion medium, wherein the spherical silica particles have a particle size of 1 μm or more and 30 μm or less, and the particle size of 3 μm or more is 300 ppm or more and 50,000 ppm or less, and the particle size of 5 μm or more is 100 ppm or less, among particles having a size of 1 μm or more and 30 μm or less, as detected by a Coulter counter, and a specific surface area of ​​5.0 m2 measured by a BET method. ２ / g or more 20.0m ２ / g or less.

2. The slurry composition according to claim 1 , wherein the spherical silica particles are surface-treated with a silane coupling agent.

3. 2. The slurry composition according to claim 1, wherein the spherical silica particles have a D50 of 0.4 μm or more and 3.0 μm or less as measured by a laser diffraction scattering method.

4. The slurry composition according to claim 1 , wherein the spherical silica particles have a circularity of 0.85 or more.

5. 2. The slurry composition according to claim 1, wherein, among the number of particles of 1 μm or more and 30 μm or less detected by a Coulter counter, the particle number frequency of 1 to 2 μm is A and the particle number frequency of 2 to 30 μm is B, and the ratio B / A is 0.002 or more and 0.20 or less.

6. 2. The slurry composition according to claim 1, wherein the spherical silica particles have a particle size of 10 μm or more and a particle size of 1 μm or more and 30 μm or less detected by a Coulter counter, and the particle size of 10 μm or more is less than 10 ppm.

7. 2. The slurry composition according to claim 1, wherein a glass cloth having a thickness of 0.09 mm and an 8 cm square is immersed in 5 mL of the slurry for 30 seconds, pulled out, and dried at 180°C for 1 hour, and the weight of the glass cloth increases by 0.1 g or more.

8. 2. The slurry composition according to claim 1, further comprising at least one inorganic filler selected from the group consisting of amorphous spherical silica particles, crystalline spherical silica particles, alumina particles, titania particles, magnesia particles, aluminum nitride particles, boron nitride particles, barium titanate particles, calcium titanate particles, and carbon fibers.

9. 2. The slurry composition according to claim 1, wherein the dispersion medium has a relative dielectric constant of 5 to 30.

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