JP2002037620A - Spherical silica particle bulk materials and method of preparing it and resin composition using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide spherical silica particle bulk materials which comprises the non-adhesive/non-agglomerative spherical silica particles and has the wide distribution area of particle diameter and is suitable as a silica filler or the like for a semiconductor sealing material, and to provide a method of preparing the same and a resin composition including the same. SOLUTION: This spherical silica particle bulk materials comprise the non- adhesive/non-agglomerative spherical silica particles having adhesion ratio of 0.1% or less (<=0.1%) and have mean particle diameter of 0.6-6 μm, particle diameter distribution area of 0.3-10 μm, and particle size distribution dispersion degree (CV value) of >=10% (10% or more). In this preparing method, the silica particle bulk materials are prepared effectively. The resin composition include the silica particle bulk materials of 10-90 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a spherical silica particle aggregate, a method for producing the same, and a resin composition using the same. More specifically, the present invention relates to a silica filler composed of non-coalesced and non-agglomerated spherical silica particles, having a wide particle size distribution range, and a silica filler suitable for a semiconductor encapsulant, particularly a flip chip underfill material. A spherical silica particle aggregate suitable as, for example, a method for efficiently producing the same, in which the degree of dispersion (CV value) of the particle size distribution can be controlled, and a semiconductor encapsulant containing the above spherical silica particle aggregate It relates to a resin composition used as such.

[0002]

2. Description of the Related Art Spherical silica particles have been used as fillers for resin encapsulants for semiconductors. In recent years, as the degree of integration of semiconductors has increased, resin encapsulants highly filled with silica particles have been required. It has become.

Incidentally, a chip-on-board method has conventionally been used as a mounting method for electronic components. This chip-on-board method includes a pin grid array, a ball grid array, etc., in which a chip is bonded to a substrate, the chip and the substrate are electrically connected by wire bonding, and the chip is sealed with a resin. is there.

[0004] Conventional chip-on-board resins contain an inorganic filler typified by silica powder in order to reduce stress strain caused by a difference in thermal expansion coefficient between the substrate and the resin. Because the place to do is on the chip,
There was no problem even if the particle size of silica was not specified.

However, in recent years, a flip-chip system, which is a mounting system in which a chip and a substrate are electrically connected by bumps and the space between the chip and the substrate is sealed with a resin, has been adopted.
Along with this, the following problems have arisen. That is, in this flip chip method,
When sealing a chip, the distance between the chip and the substrate is 100 μm
Because of the narrowness below, conventional resin for chip-on-board using silica having a particle size of 50 μm or more has poor filling property of the resin between the chip and the substrate, and cannot be used for sealing.

In particular, recently, the gap between the substrate and the chip has been reduced to about 10 to 20 μm, and the gap tends to be narrower in the future, and a sealing material having an excellent filling property (flowability) is required. In this case, the viscosity of the sealing material itself,
Filler size is important.

[0007] Further, in order to achieve low thermal expansion and high thermal conductivity of the sealing material, high filling of the filler is desired. For this purpose, a filler having a small particle size (submicron to several micron level) is required. Become. Furthermore, as the shape of the filler, problems such as local stress, deformation of the gold wire during low pressure transfer molding due to increase in melt viscosity during high filling,
From the viewpoint of cutting problems and the like, true spherical fillers are preferred.

On the other hand, memory cells have been reduced in size and miniaturized with higher integration, and measures against soft errors have become more important, and lower α-rays have been required. The main cause of the generation of α-rays is uranium and thorium contained in the silica particles, which are presently at a level of 0.1 ppm, but further reduction is desired, and the amount of ionic impurities is small. Is desired.

For the spherical silica particles, various techniques have been used so far, for example, (1) fine fused spherical silica and its production method (Japanese Patent Publication No. 6-96445), (2) high-purity spherical silica and its production method ( Kaihei 7-69617
And (3) a method for producing monodispersed spherical silica (JP-A-6-87608), and (4) a method for producing spherical silicone fine particles (Japanese Patent Publication No. 5-88889).

However, the fine fused spherical silica of the above (1) has a uranium and thorium content of 1 ppb or less and an average particle size of 10 μm or less, but has a wide particle size distribution range and a particle size distribution of 0.2 μm or less. Fine particles, especially 10 μm
Many of these particles are present. The high-purity spherical silica (2) has a high purity, such as a radioactive substance content of 1 ppb or less, an ionic impurity of 1 ppm or less, and an electric conductivity of the boiling leached extraction water of 10 μS / cm or less. However, according to the production method, it is difficult to control the particle size distribution, and there is a possibility that agglomerated / coalesced particles may be present. According to the method (3) for producing monodispersed spherical silica, it is possible to control the particle size and narrow the particle size distribution by selecting the reaction conditions, but it is not possible to control the particle size distribution as it is. It is possible. In addition, looking at the shape of the particle size distribution,
From the peak centered on the particle size to the smaller or larger one, the distribution has a long tail, and there are ultrafine particles of 0.3 μm or less and coarse particles of 10 μm or more. According to the method (4) for producing spherical silicone fine particles, particles having a narrow particle size distribution or particles having a high CV value are obtained by high stirring, but control of the particle size distribution is not always easy.

The present inventors have previously proposed a method for producing polyorganosiloxane fine particles using an anionic surfactant (Japanese Patent Laid-Open No. 11-181095). However, the silica fine particles obtained by this method have a small CV value and are suitable for a liquid crystal spacer in which particles having a narrow particle size distribution are required. However, when manufacturing the particles, an anionic surfactant is used. Because it is used, it is easy to mix ionic impurities, it is not suitable as a filler for semiconductor encapsulant,
In addition, it is not suitable as a filler for semiconductor encapsulant from the viewpoint of a decrease in fluidity of the encapsulant.

[0012]

SUMMARY OF THE INVENTION Under such circumstances, the present invention provides a silica for semiconductor encapsulant comprising non-coalesced and non-agglomerated spherical silica particles, having a wide particle size distribution range. Filler, especially a spherical silica particle aggregate suitable as a silica filler suitable for an underfill material for flip chip, a method for efficiently producing the same, the CV value of which can be controlled, and the spherical silica particle aggregate It is an object of the present invention to provide a resin composition which is used for a semiconductor sealing material.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have a coalescence rate of a certain value or less, and have an average particle size and a distribution width of the particle size. It has been found that a spherical silica particle aggregate having a specific range and a CV value not less than a certain value can be suitable for the purpose as a silica filler for a semiconductor sealing material.

Further, the concentration of the nonionic surfactant or anionic surfactant and the concentration of ammonia as a hydrolysis catalyst are controlled to hydrolyze and condense the alkoxysilane compound or its partially hydrolyzed condensate to form a polyorgano-organic compound. After producing siloxane particles, by performing a washing treatment, a drying treatment and a baking treatment at a specific temperature in the presence of oxygen,
It has been found that the CV value can be easily controlled, and a spherical silica particle aggregate having desired properties can be easily obtained.

The present invention has been completed based on such findings. That is, according to the present invention, (1) the coalescence rate is 0.5.
An aggregate of non-coalesced and non-agglomerated spherical silica particles of 1% or less, having an average particle size of 0.6 to 6 µm, a particle size distribution range of 0.3 to 10 µm, and a degree of particle size distribution ( CV value) of 10% or more,

(2) (A) An aqueous solution containing 1 × 10 ^-2 to 1 × 10 ^-4 % by weight of a nonionic surfactant or an anionic surfactant is mixed with a compound of the formula (I) R ¹ nSi (OR ² _4-n (I) wherein R ¹ is a non-hydrolyzable group and has 1 to 2 carbon atoms.
An alkyl group having 0 alkyl group, a (meth) acryloyloxy group or an epoxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl having 7 to 20 carbon atoms group, R ² is an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 to 3, R ¹
There when there are a plurality, each R ¹ may be different from one another identical, if OR ² there are a plurality, each OR ² may be different even identical to each other. )) And / or a partially hydrolyzed condensate thereof is added and dissolved, and the ammonia concentration is adjusted to 0.25.
Aqueous ammonia is added so as to be from × 10 ^{−3 to} 150 × 10 ⁻³ mol / l, and the organosilicon compound and / or its partially hydrolyzed condensate is hydrolyzed and condensed. And then aging by adding ammonia and / or amine, (B) a step of washing the particles obtained in step (A), and (C) a step of (B) (D) drying the particles obtained in step (C) in the presence of oxygen,
Baking at a temperature of 1100 ° C., a method for producing a spherical silica particle aggregate, and

(3) A resin composition characterized by containing 10 to 90% by weight of the aggregate of spherical silica particles of the above (1).

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The spherical silica particle aggregate of the present invention is an aggregate (powder) of non-coalesced and non-agglomerated spherical silica particles, the coalescence rate of which is 0.1%. It is as follows. With an aggregate having a coalescence rate of more than 0.1%, the object of the present invention cannot be sufficiently achieved, and the performance as a silica filler for semiconductor encapsulation, in particular, an underfill material for flip chips becomes insufficient.

The aggregate has a particle size distribution width of 0.3.
It needs to be in the range of 10 to 10 μm. Particle size is 0.
When particles less than 3 μm are present, when used as a silica filler for semiconductor encapsulation, the viscosity of the resin encapsulant increases,
It causes a decrease in fluidity. On the other hand, the particle size is 10 μm
Particles may be larger than the gap between the substrate and the chip, making the particles unsuitable for flip-chip underfill materials. In order to keep the particle size distribution width within the above range, it is necessary to control the average particle size of the aggregate in the range of 0.6 to 6 μm. If the average particle size is out of this range, it becomes difficult to obtain a desired particle size distribution width.

Further, the spherical silica particle aggregate of the present invention has a degree of dispersion (CV value) of particle size distribution of 10% or more.
When the CV value is less than 10%, the aggregate approaches monodispersion. In this case, if the particle size of the particles is small, the filling rate can be increased, but the viscosity of the resin sealing material increases, and the fluidity decreases. descend. On the other hand, when the particle diameter is large, the increase in viscosity of the resin sealing material can be suppressed, but the filling rate decreases. Therefore, in the present invention, by increasing the CV value to 10% or more and broadening the distribution, the filling rate is improved and the increase in viscosity is suppressed. A preferred CV value is in the range of 10 to 40%, particularly preferably in the range of 10 to 25%.

The degree of dispersion (CV value) of the particle size distribution is determined by the following equation. CV value (%) = (standard deviation of particle size / average particle size) × 100 In the spherical silica particle aggregate of the present invention, 3%
The water absorption when held in an atmosphere of 0 ° C. and RH 90% for 48 hours is preferably 1.5% by weight or less. If the water absorption exceeds 1.5% by weight, the performance as a silica filler for semiconductor encapsulation becomes insufficient, which is not preferable. More preferably, the water absorption is 1% by weight or less, further preferably 0.6% by weight or less.

Further, the aggregate preferably has a total content of uranium and thorium of 0.5 ppb or less, and a content of ionic impurities of 1 ppm or less. Uranium and thorium are α-ray emitting materials, and if their total content exceeds 0.5 ppb, it causes soft errors, especially in high-density integrated circuit electronic components.
A more preferred total content of uranium and thorium is 0.1.
2 ppb or less.

Also, alkali metals such as Na, K and Li, alkaline earth metals such as Ca and Mg, and ionic impurities such as Cl cause corrosion of aluminum wiring. The content of the ionic impurities is preferably 1 ppm or less, more preferably 0.5 ppm or less.

The spherical silica particle aggregate according to the present invention includes a compound represented by the following general formula (I): R ¹ nSi (OR ² ) _4-n (I) wherein R ¹ is a non-hydrolyzable group. And carbon number 1-2
An alkyl group having 0 alkyl group, a (meth) acryloyloxy group or an epoxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl having 7 to 20 carbon atoms group, R ² is an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 to 3, R ¹
There when there are a plurality, each R ¹ may be different from one another identical, if OR ² there are a plurality, each OR ² may be different even identical to each other. The polyorganosiloxane particle aggregate obtained by hydrolyzing and condensing the organosilicon compound represented by the formula (1) is preferably fired in the presence of oxygen.

In R ¹ in the above general formula (I),
Examples of the alkyl group having 1 to 20 carbon atoms include 1 to 10 carbon atoms.
And the alkyl group may be linear, branched or cyclic. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, cyclopentyl. Group, cyclohexyl group and the like. As the alkyl group having 1 to 20 carbon atoms having a (meth) acryloyloxy group or an epoxy group, an alkyl group having 1 to 10 carbon atoms having the above substituent is preferable, and the alkyl group is linear, branched,
Any of a ring shape may be sufficient. Examples of the alkyl group having the substituent include a γ-acryloyloxypropyl group, a γ-methacryloyloxypropyl group, a γ-glycidoxypropyl group, and a 3,4-epoxycyclohexyl group. The alkenyl group having 2 to 20 carbon atoms is preferably an alkenyl group having 2 to 10 carbon atoms, and the alkenyl group may be linear, branched or cyclic. Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a hexenyl group, an octenyl group and the like. The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. The aralkyl group having 7 to 20 carbon atoms is preferably an aralkyl group having 7 to 10 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a phenylpropyl group, and a naphthylmethyl group.

On the other hand, the alkyl group having 1 to 6 carbon atoms represented by R ² may be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group and an n-propyl group. Group, isopropyl group, n-butyl group, isobutyl group,
sec-butyl group, tert-butyl group, pentyl group,
Examples include a hexyl group, a cyclopentyl group, and a cyclohexyl group.

Examples of the organosilicon compound represented by the general formula (I) include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane. Silane, propyltriethoxysilane, butyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane , Γ-methacryloyloxypropyltrimethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane and the like. Of these, methyltrimethoxysilane and vinyltrimethoxysilane are particularly preferred.
One of these organosilicon compounds may be used alone, or two or more thereof may be used in combination.

According to the method of the present invention, the spherical silica particle aggregate of the present invention having the above-mentioned properties can be prepared as follows: (A) a process for producing polyorganosiloxane particles, (B) a washing process, and (C) a drying process. By performing the treatment step and the firing treatment step (D), efficient production can be achieved.

Next, each step will be described. Step (A) In this step (A), the organosilicon compound represented by the general formula (I) and / or its hydrolyzed condensate is hydrolyzed in an aqueous solution containing a surfactant in the presence of ammonia. This is a step of producing polyorganosiloxane particles by decomposition and condensation.

In this step, a nonionic surfactant or an anionic surfactant is used as the surfactant. Here, as the nonionic surfactant, those having an HLB value in the range of 8 to 20 are preferably used. This HLB is an index indicating the balance between hydrophilicity and lipophilicity, and the smaller the value, the higher the lipophilicity.
If the HLB value is out of the above range, the effects of the present invention will not be sufficiently exhibited. In order to further exert the effects of the present invention, those having an HLB value in the range of 10 to 17 are preferable.

As the nonionic surfactant, HLB is used.
The value is not particularly limited as long as it is within the above range, and for example, oxidation of polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolin derivative, alkylphenol formalin condensate Ether type nonionic surfactants such as ethylene derivatives, polyoxyethylene polyoxypropylene block polymers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene glycerin fatty acid esters, polyoxyethylene castor oil and hydrogenated castor oil, polyoxyethylene Sorbitan fatty acid esters,
Ether-type nonionic surfactants such as polyoxyethylene sorbitol fatty acid esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, and ester nonionic surfactants such as sucrose fatty acid esters; Examples include nitrogen-containing nonionic surfactants such as polyoxyethylene fatty acid amides, polyoxyethylene alkylamines, and alkylamine oxides. Among them, ether-type surfactants are preferable, and polyoxyethylene alkylphenyl ether is particularly preferable. is there. These nonionic surfactants may be used alone or in combination of two or more.

On the other hand, as the anionic surfactant, H
Those having an LB value in the range of 18 to 42 are preferably used. If the HLB value is out of the above range, the effects of the present invention will not be sufficiently exhibited. Such anionic surfactant may have an HLB value in the range of 18 to 42, and is not particularly limited. Examples thereof include alkyl aryl sulfonates, alkyl sulfates, fatty acid alkali salts, alkyl phosphates, and the like. And alkyl phosphonates. Among these, an alkylaryl sulfonate having an alkyl group having 8 to 18 carbon atoms, an alkyl group having 8 carbon atoms
To 18 alkyl sulfates, wherein the alkyl group has 8 to 1 carbon atoms
Preferred are fatty acid alkali salts of No. 8, particularly preferred are sodium dodecyl sulfate, dodecyl benzene sulfonate and potassium oleate. The anionic surfactant may be used alone or in combination of two or more.

When comparing the nonionic surfactant with the anionic surfactant, it is advantageous to use the nonionic surfactant rather than the anionic surfactant in view of mixing of ionic impurities. is there. In the step (A), first, an aqueous solution containing 1 × 10 ⁻² to 1 × 10 ⁻⁴ wt% of the nonionic or anionic surfactant is prepared. If the concentration of the surfactant is out of the above range, particles having a low CV value are generated, and particles having a CV value of 10% or more are not generated, and the object of the present invention cannot be achieved.

The aqueous solution containing a nonionic surfactant or an anionic surfactant is prepared by dissolving the surfactant in water or an aqueous solvent comprising a mixed solvent of water and a water-miscible organic solvent. Solution. Here, examples of the water-miscible organic solvent include lower alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, dimethyl ketone and methyl ethyl ketone, and ethers such as diethyl ether and dipropyl ether. .

Next, the organic silicon compound represented by the general formula (I) and / or a portion thereof is added to the aqueous solution containing a predetermined concentration of a nonionic surfactant or an anionic surfactant. The hydrolysis-condensation product is added in an amount of preferably 0.01 to 0.3 part by weight with respect to 1 part by weight of the aqueous medium, and dissolved by stirring to obtain a transparent solution.
At this time, if the amount of the organosilicon compound or its hydrolyzed condensate is less than the above range, the production efficiency is poor and impractical. If the amount is more than the above range, gelation may occur and particles may not be formed.

The clear solution is then added to the clear solution,
Aqueous ammonia at a concentration of 5 to 2 mol / l is added so that the NH ₃ concentration becomes 0.25 × 10 ^{−3 to} 150 × 10 ⁻³ mol / l, and the mixture is slowly stirred to add the organosilicon compound or a hydrolyzate thereof. The decomposition condensate is hydrolyzed and condensed. At this time, NH ₃ concentration is hydrolyzed with less than 0.25 × 10 ^-3 mol / liter, hardly condensation reaction proceeds to may not precipitated particles is more than 0.99 × 10 ^-3 mol / liter if Adhered particles and aggregated particles are generated, and the object of the present invention cannot be achieved. That is, by performing synthesis within this concentration range, true spherical particles can be obtained.

The reaction temperature at this time depends on the type of the raw material organosilicon compound and its hydrolysis-condensation product.
Generally, it is selected in the range of 0 to 60 ° C. As the hydrolysis and condensation reactions proceed, particles are precipitated, and the precipitated particles grow. After completion of the grain growth, aging is performed by adding ammonia and / or amine. In this case, as the amine, for example, monomethylamine, dimethylamine, monoethylamine, diethylamine, ethylenediamine and the like can be preferably mentioned.

The amount of ammonia or amine to be added is not particularly limited, but is preferably selected so that the pH of the reaction system is in the range of 9.0 to 12.0. The aging temperature may be the same as that in the above-mentioned reaction, or may be performed after slightly raising the temperature. The aging time depends on the reaction temperature and the pH, and cannot be unconditionally determined.
About an hour is enough. In this way, non-coalesced, non-agglomerated, spherical polyorganosiloxane particles having a large degree of dispersion (CV value) in particle size distribution can be obtained.

Step (B) Step (B) is a step of washing the polyorganosiloxane particles obtained in step (A). The washing treatment of the particles in this step is not particularly limited,
According to a conventional method, a sufficient washing treatment is performed using a lower alcohol such as methanol. After the washing treatment, if necessary, a classification treatment may be performed to remove the maximum particles or the minimum particles, and the drying step of the next step may be performed. The classification method is not particularly limited, but a wet classification method in which classification is performed by utilizing the fact that the sedimentation speed varies depending on the particle size is preferable.

Step (C) The step (C) is a step of drying the polyorganosiloxane particles obtained by washing in the above (B) and, if necessary, further classifying. The drying treatment in this step is usually performed at a temperature in the range of 100 to 200C.

Step (D) Step (D) is a step of firing the polyorganosiloxane particles dried in step (C) in the presence of oxygen. This firing process is performed in the presence of oxygen,
It is advantageous to fire in air from the viewpoint of economy. The firing temperature ranges from 350 to 1100 ° C. This temperature is 3
If the temperature is lower than 50 ° C., the sintering is insufficient.
It is not necessary to bake at a temperature higher than 1 ° C., and baking can be performed sufficiently at a temperature of 1100 ° C. or less. preferable. There is no particular limitation on the firing apparatus, and an electric furnace, a rotary kiln, or the like can be used. Thus, the spherical silica particle aggregate of the present invention having the above-mentioned properties can be efficiently produced.

The present invention also provides a resin composition containing 10 to 90% by weight of the spherical silica particle aggregate of the present invention having the above-mentioned properties, particularly a resin composition used for a semiconductor resin sealing material. I do. Examples of the resin composition used for the semiconductor resin encapsulant include (a) an epoxy resin, (b) a curing agent, (c) the aggregate of spherical silica particles of the present invention, and other various kinds. Including additives,
Further, there can be mentioned a composition in which the content of the component (C) is 10 to 90% by weight.

In the resin composition, the epoxy resin used as the component (a) may be a curable epoxy resin having two or more epoxy groups in one molecule, and is not particularly limited. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, novolak type epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, etc., which are low in chloride ion and sodium ion Is preferred. These epoxy resins can be used alone or in combination of two or more. In addition to these epoxy resins, phenol novolak type epoxy resin, cresol novolak type epoxy resin, heterocyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, aliphatic epoxy resin, aromatic, aliphatic or alicyclic An epoxy resin obtained by reacting the carboxylic acid of the formula with epichlorohydrin, a spiro ring-containing epoxy resin, and the like can be appropriately used in combination.

The curing agent used as the component (b) is preferably an acid anhydride, for example, phthalic anhydride-type derivatives such as methylhexahydrophthalic acid and methyltetrahydrophthalic acid, and methylnadic anhydride. These can be used alone or in combination of two or more.

The spherical silica particle aggregate of the present invention used as the component (c) is as described above. The content of the component (c) is selected in the range of 10 to 90% by weight, preferably 30 to 90% by weight, and more preferably 50 to 90% by weight.

The resin composition may contain, if necessary, other various additives such as a coloring agent, a stress relieving agent, a defoaming agent, a leveling agent, and a coupling agent within a range that does not impair the object of the present invention. , A flame retardant, a curing accelerator and the like can be appropriately compounded.

The resin composition of the present invention can be produced by thoroughly mixing the above-mentioned components, kneading with, for example, a three-roll mill, and then defoaming under reduced pressure according to a conventional method. The resin composition thus obtained is suitable as a semiconductor resin sealing material, particularly for flip chip sealing.

[0048]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 In a 300 ml plastic container set in a thermostat at 30 ° C., polyoxyethylene alkyl aryl ether “Neugen EA” as a nonionic surfactant adjusted to various concentrations shown in Table 1. -157 (HLB
15) "(Daiichi Kogyo Seiyaku Co., Ltd.) ion exchange aqueous solution 200
Methyltrimethoxysilane (MTMS) in milliliter
20 g was added, and the mixture was stirred with a magnetic stirrer until a clear homogeneous solution was obtained. Then, 1 mol /
One liter of aqueous ammonia was added so that the concentration of the aqueous ammonia with respect to the ion-exchanged water was 1.0 ml / liter, and the mixture was stirred at about 50 rpm. After the particles precipitate and grow and the solution becomes cloudy, the particle growth is observed with an optical microscope.
Two milliliters of 5% by weight ammonia water was added, and the mixture was aged overnight.

After completion of the reaction, the stirring was stopped, the particles and the solvent were separated by a centrifugal separator, the supernatant was discarded, and methanol was further added to disperse the particles again. Repeat the particle separation by centrifugal separator and the particle washing by adding methanol again.
Repeated times. Finally, methanol was removed, and drying treatment was performed at 120 ° C. for 1 hour in an oven to obtain polymethylsilsesquioxane (PMSO) particles.

The obtained particles after drying are white powders which are water-repellent and excellent in fluidity.
00 measurements were made to determine the average particle size and its CV value. The particle size distribution of the obtained particles was measured using the entire peak as a measurement range. As a result, as shown in Table 1, the CV value differs depending on the surfactant concentration. In Experiments 3 to 7, the CV value was 10%. PMSO particles having the above broad peak were obtained. In addition, as a result of observation with a scanning electron microscope (SEM) at the same time, the particles were truly spherical, monodisperse particles having no coalescence or aggregation. In addition, fine particles of less than 0.3 μm or 10 μm
No coarse particles of m or more were also present.

[0052]

[Table 1]

Example 2 The concentration of the nonionic surfactant "Neugen EA-157" was as shown in Table 2, and 1 mol / l of ammonia water was added to the ion-exchanged water at a concentration of 2.5 ml. Per liter except that the PMS was dried.
O particles were obtained. The average particle size and CV value were measured using a Coulter counter in the same manner as in Example 1. As shown in Table 2, the CV value differs depending on the surfactant concentration.
From 11 to 13, PMSO particles having a broad peak with a CV value of 10% or more were obtained. In addition, as a result of observation with a scanning electron microscope (SEM) at the same time, the particles were truly spherical, monodisperse particles having no coalescence or aggregation. Also, 0.3μ
There were no fine particles smaller than m or coarse particles larger than 10 μm.

[0054]

[Table 2]

Example 3 Except that the concentration of the nonionic surfactant "Neugen EA-157" was 1 × 10 ^-3 % by weight and the concentration of 1 mol / l ammonia water with respect to ion-exchanged water was as shown in Table 3. The same operation as in Example 1 was performed, and PMS after drying was performed.
O particles were obtained. As a result of measuring the average particle size and the CV value with a Coulter counter in the same manner as in Example 1, as shown in Table 3, broad particles having a particle size distribution with a CV value of 10% or more were obtained. In addition, as a result of observation with a scanning electron microscope (SEM) at the same time, the particles were truly spherical, monodisperse particles having no coalescence or aggregation. Also, there were no fine particles smaller than 0.3 μm or coarse particles larger than 10 μm.

[0056]

[Table 3]

Example 4 500 g of MTMS was added to 5000 ml of an EA-157 ion exchange aqueous solution adjusted to a concentration of 1 × 10 ⁻³ wt% in a 5000 ml separable flask set in a thermostat at 30 ° C. Then, the mixture was stirred with a stirring blade until a clear homogeneous solution was obtained. Next, 1 mol / l ammonia water was added thereto so that the concentration of the ammonia water with respect to the ion-exchanged water was 1.0 ml / l, followed by stirring at 30 rpm. After the particles were precipitated and grown and the solution became cloudy, the particles were observed for growth with an optical microscope.
10 ml of 5% by weight aqueous ammonia was added, and the mixture was aged overnight.

After completion of the reaction, the stirring was stopped, and the particles and the solvent were separated by a centrifugal separator. The supernatant was discarded, and methanol was further added to disperse the particles again. Repeat the particle separation by centrifugal separator and the particle washing by adding methanol again.
Repeated times. Finally, methanol was removed, and drying treatment was performed at 120 ° C. for 1 hour in an oven to obtain PMSO particles.

The resulting dried white powder was measured for 50,000 particles using a Coulter counter, and the average particle size and its CV value were measured. The particle size distribution of the obtained particles was measured using the entire peak as a measurement range, and as a result, the average particle size was 1.64.
PMSO particles having a broad peak of μm and a CV value of 13.1% were obtained.

At the same time, a scanning electron microscope (SEM)
As a result, it was found that the particles were truly spherical and monodispersed without coalescence or aggregation. In addition, fine particles of less than 0.3 μm or 10
No coarse particles exceeding μm were also present. The obtained white powder was once held at 400 ° C. for 24 hours while blowing air at a flow rate of 4 ml / min, and then calcined at 800 ° C. for 9 hours.

The powder obtained after calcination was a white powder which was easily dispersed in water, had excellent fluidity, and had no agglomerates.
As a result of measuring 50,000 pieces with a Coulter counter, the average particle diameter was 1.37 μm and the CV value was 13.4%.
PMSO particles having a broad peak were obtained.
At the same time, as a result of observation with a scanning electron microscope (SEM), the particles were truly spherical, monodisperse particles without coalescence or aggregation. Also, there were no fine particles smaller than 0.3 μm or coarse particles larger than 10 μm.

After the firing, the particles were measured by IR. As a result, it was found that the methyl group as an organic component was completely decomposed. Further, as a result of examining the contents of uranium and thorium by ICP-MS, it was found that uranium was 0.1 ppb and thorium was 0.04 ppb, each of which was 0.1 ppb or less and high purity. In addition, as a result of measurement by a flameless atomic absorption method, Fe was 0.3 ppm,
K was 0.04 ppm and Ca was 0.07 ppm. As a result of measurement by ion chromatography after the extraction of the ionic components, Cl ^- ion was found to have a detection limit of 1 pp.
m or less, indicating high purity. Next, 30
The water absorption after holding for 48 hours in an atmosphere of 90 ° C. and RH 90% was 0.54%. FIG. 1 shows a scanning electron micrograph of the fired PMSO particles, and FIG. 2 shows a Coulter chart of the fired PMSO particles.

Comparative Example 1 The same operation as in Example 1 was carried out except that the concentration of the nonionic surfactant “Neugen EA-157” was as shown in Table 4, to obtain dried PMSO particles. As a result of measuring the average particle size and the CV value using a Coulter counter in the same manner as in Example 1, as shown in Table 4, PMV particles having a small CV value and a very uniform particle size were obtained.

[0064]

[Table 4]

FIG. 3 shows a scanning electron micrograph of the dried PMSO particles obtained in Experiment No. 1 of Comparative Example 1.

Comparative Example 2 The same operation as in Example 1 was carried out except that the concentration of 1 mol / l aqueous ammonia was as shown in Table 5, and the dried P
MSO particles were obtained. However, in Experiment No. 4, no particles were precipitated, and PMSO particles were not obtained. The average particle diameter and the CV value were measured by a Coulter counter in the same manner as in Example 1. As a result, PMSO particles having a broad CV value and a broad peak were obtained as shown in Table 5. On the other hand, as a result of observation with a scanning electron microscope (SEM) at the same time, as a result, there were particles which were truly spherical, had coalescence and aggregation, and also had aggregates exceeding 10 μm.

[0067]

[Table 5]

FIG. 4 is a scanning electron micrograph of the dried PMSO particles obtained in Experiment No. 7 of Comparative Example 2. In Experiments Nos. 17, 20, 23, and 25 of Example 3 and Experiments Nos. 5 to 7 of Comparative Example 2, the number of coalesced particles was measured by SEM photograph observation after washing the particles with a centrifugal separator. And the following equation: Cohesion rate (%) = (Number of coalesced particles / Number of all particles measured) × 1
00, the coalescence rate was calculated. Table 6 shows the results.

[0069]

[Table 6]

[0070]

The spherical silica particle aggregate of the present invention comprises non-coalesced and non-agglomerated spherical silica particles, has a wide particle size distribution range, and is a silica filler for semiconductor encapsulants, especially for flip chips. It is suitable as a silica filler suitable for an underfill material. Further, according to the method of the present invention, the aggregate of spherical silica particles can be efficiently produced.

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph of fired PMSO particles obtained in Example 4.

FIG. 2 is a Coulter chart of fired PMSO particles obtained in Example 4.

FIG. 3 shows dry PMSO obtained in Experiment No. 1 of Comparative Example 1.
FIG. 3 is a scanning electron micrograph of particles.

FIG. 4 shows dry PMSO obtained in Experiment No. 7 of Comparative Example 2.
FIG. 3 is a scanning electron micrograph of particles.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/29 H01L 23/30 R 23/31 F term (Reference) 4G072 AA25 BB05 DD04 DD05 HH30 JJ23 LL06 MM02 MM21 MM22 MM23 MM31 MM36 PP05 QQ06 RR05 RR12 TT01 TT02 TT21 UU01 UU09 4H017 AA27 AA39 AE05 4J002 CD021 CD051 CD061 CD131 DJ016 FA086 4J037 AA17 AA18 CA18 CB16 DD05 DD17 DD24 EE19 EE14 EE33

Claims (9)

[Claims] 1. An aggregate of non-coalesced and non-agglomerated spherical silica particles having a coalescence rate of 0.1% or less, and having an average particle diameter of 0.1%.
A true spherical silica particle aggregate having a particle size distribution of 6 to 6 μm, a particle size distribution width of 0.3 to 10 μm, and a particle size distribution dispersion (CV value) of 10% or more. 2. Under an atmosphere of 30 ° C. and 90% RH, 48
2. The spherical silica particle aggregate according to claim 1, wherein the water absorption when held for a time is 1.5% by weight or less. 3. The total content of uranium and thorium is 0.5 ppb or less, and the content of ionic impurities is 1
The spherical silica particle aggregate according to claim 1 or 2, which is not more than ppm. 4. Formula (I) R ¹ nSi (OR ² ) _4-n ... (I) wherein R ¹ is a non-hydrolyzable group and has 1 to 2 carbon atoms.
An alkyl group having 0 alkyl group, a (meth) acryloyloxy group or an epoxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl having 7 to 20 carbon atoms group, R ² is an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 to 3, R ¹
There when there are a plurality, each R ¹ may be different from one another identical, if OR ² there are a plurality, each OR ² may be different even identical to each other. 4. The spherical silica particle aggregate according to claim 1, 2 or 3, wherein the polyorganosiloxane particle aggregate obtained by hydrolyzing and condensing the organosilicon compound represented by the formula) is fired in the presence of oxygen. . 5. An organosilicon compound represented by the general formula (I) in an aqueous solution containing (A) a nonionic surfactant or an anionic surfactant in an amount of 1 × 10 ⁻² to 1 × 10 ⁻⁴ % by weight. And / or after adding and dissolving the partially hydrolyzed condensate, the ammonia concentration is 0.25 × 10 ^{−3 to} 150.
Aqueous ammonia is added so that the concentration becomes × 10 ⁻³ mol / l, the organosilicon compound and / or its partially hydrolyzed condensate is hydrolyzed and condensed, and then the precipitated particles are grown. (B) a step of washing the particles obtained in the above step (A), and (C) a step of washing the particles obtained in the above step (A). A step of drying and a step of (D) baking the particles obtained in the step (C) at a temperature of 350 to 1100 ° C. in the presence of oxygen. How to make the body. 6. The method according to claim 1, wherein in the step (D), 350 to 350
The method according to claim 5, wherein the calcination is performed at a temperature of 1100 ° C. 7. The method according to claim 5, wherein in the step (D), a calcination treatment is performed at a temperature at which organic components are completely decomposed and removed. 8. A resin composition comprising 10 to 90% by weight of the aggregate of spherical silica particles according to any one of claims 1 to 4. 9. The resin composition according to claim 8, which is used for a semiconductor resin sealing material.