JP2021059740A - Surface-treated silica filler, production method thereof, and resin composition containing surface-treated silica filler - Google Patents

Abstract

To provide a surface-treated silica filler for suppressing an increase in viscosity when added to a resin composition used for applications such as a semiconductor sealing material, and a resin composition containing the surface-treated silica filler.SOLUTION: The surface-treated silica filler of the present invention is surface-treated with a basic substance having an acid dissociation constant (pKa) of its conjugate acid of 9.4 or more.SELECTED DRAWING: None

Description

The present invention is a surface treatment compounded in a semiconductor encapsulant, a one-component adhesive used in the manufacture of electronic parts, and a resin composition used as an adhesive film used as an NCF (Non Conductive Film) in semiconductor mounting. The present invention relates to a silica filler and a resin composition containing the surface-treated silica filler.

With the miniaturization, weight reduction, and high performance of electronic devices, the mounting form of semiconductors is changing from the wire bond type to the flip chip type.
The flip-chip type semiconductor device has a structure in which an electrode portion on a substrate and a semiconductor element are connected via bump electrodes. In a semiconductor device having this structure, when heat is applied such as a temperature cycle, stress is applied to the bump electrode due to the difference in the coefficient of thermal expansion between the substrate made of an organic material such as epoxy resin and the semiconductor element, and the bump electrode The problem is that defects such as cracks occur. In order to suppress the occurrence of this defect, a semiconductor encapsulant called underfill is used to seal the gap between the semiconductor element and the substrate, and both are fixed to each other to improve the thermal cycle resistance. Is widely practiced.

As a method of supplying the underfill material, after connecting the semiconductor element and the electrode portion on the substrate, the underfill material is applied (dispensed) along the outer periphery of the semiconductor element, and the capillary phenomenon is utilized. A capillary flow in which an underfill material is injected into the gap between the two is common. After injecting the underfill material, the underfill material is heat-cured to reinforce the connection portion between the two.

The underfill material is required to be excellent in injectability, adhesiveness, curability, storage stability and the like. Further, the portion sealed with the underfill material is required to have excellent moisture resistance, thermal cycle resistance, and the like.

In order to satisfy the above requirements, an underfill material containing an epoxy resin as a main component is widely used.
In order to improve the moisture resistance and thermal cycle resistance of the part sealed with the underfill material, particularly the thermal cycle resistance, a filler made of an inorganic substance (hereinafter referred to as "inorganic filler") is referred to as an underfill material. It is known that it is effective to control the difference in thermal expansion coefficient between the substrate made of an organic material such as epoxy resin and the semiconductor element and to reinforce the bump electrode by adding it to. See Patent Document 1).
As the inorganic filler added for this purpose, a silica filler is preferably used because of its high electrical insulating property and low coefficient of thermal expansion.

However, there is a problem that the silica filler tends to aggregate in the semiconductor encapsulant, is non-uniform, and has a high viscosity, resulting in low fluidity and the inability to further improve moldability.
In order to solve the above problem, Patent Document 2 proposes to treat the surface of the silica filler with a basic substance or a basic mixture. In Patent Document 2, one or more of the above basic substances or basic mixtures are selected from a cyclic compound containing ammonia, organic amines, silazanes, nitrogen or a solution thereof, an amine-based silane coupling agent or a solution thereof. Among these, silazanes are preferable, and hexamethyldisilazane (HMDS) is particularly preferable.

Japanese Unexamined Patent Publication No. 10-173103 Patent No. 5220981

Patent Document 2 does not specify the reason for treating the surface of the silica filler with a basic substance or a basic mixture, but it is presumed to be the following reason.
Since acidic silanol groups are present on the surface of the silica filler, the following problems may occur when added to the semiconductor encapsulant.

(1) The silanol group on the surface of the silica filler acts as an acid catalyst, and homopolymerization of the epoxy resin contained in the semiconductor encapsulant proceeds, so that the semiconductor encapsulant may be thickened or unintentionally cured.

(2) Generally, in order to increase the amount of filler blended in the semiconductor encapsulant, the silica filler may be surface-treated with a silane coupling agent and used. In this case, the filler itself acts as an acid catalyst and the silane coupling agent. Deterioration of silane is promoted, and agglomeration of filler and deterioration of handleability may occur. The silane coupling agent can also be used by directly blending it with the resin, but in this case as well, the acidic silanol groups present on the surface of the silica filler promote the hydrolysis of the silane coupling agent, and a large amount of alcohol is produced. Therefore, there is a risk that problems such as thickening will become noticeable.

In addition to semiconductor encapsulants, silica fillers are also added to one-component adhesives used in the manufacture of electronic components and adhesive films used as NCFs (Non Conductive Films) when mounting semiconductors. However, there are concerns about the problems (1) and (2) described above.

In Patent Document 2, it is presumed that the above problems (1) and (2) are prevented by neutralizing the acidic silanol group existing on the surface of the silica filler with a basic substance or a basic mixture. ..
Specifically, the above problems (1) and (2) are prevented by chemically adsorbing a basic substance or a basic mixture on an acidic silanol group existing on the surface of the silica filler and neutralizing the group. I guess there is.

However, it has been found that the treatment method described in Patent Document 2 cannot always exert the action and effect of the neutralization treatment.
As a result of diligent studies on this point, the inventor of the present application has found that the action and effect of the neutralization treatment are impaired during the pre-drying performed prior to the use of the silica filler.

Since the silica filler may absorb moisture during storage and there is a concern about the adverse effect of the moisture when using the silica filler, pre-drying is often performed prior to use. In the case of silica filler, pre-drying is carried out at a temperature of about 150 ° C. for about 4 hours.
During this pre-drying, the basic substance or basic mixture chemically adsorbed on the acidic silanol groups present on the surface of the silica filler may be desorbed by the neutralization treatment, and the effect of the neutralization treatment may not be exhibited. I found that there is. During the pre-drying, the basic substance or basic mixture chemically adsorbed on the acidic silanol groups present on the surface of the silica filler is desorbed from the surface of the silica filler before and after the heat treatment in the examples described later. It is confirmed by the change in pH of.

In order to solve the above-mentioned problems in the prior art, the present invention is a surface-treated silica filler that suppresses an increase in viscosity when added to a resin composition used for applications such as semiconductor encapsulants, and the surface treatment. An object of the present invention is to provide a resin composition containing a silica filler.

In order to achieve the above object, the present invention provides a surface-treated silica filler characterized by surface-treating with a basic substance having an acid dissociation constant (pKa) of a conjugate acid of 9.4 or more.

In the surface-treated silica filler of the present invention, the basic substances having a pKa of 9.4 or more are benzylamine, 2-methoxyethylamine, 3-amino-1-propanol, 3-aminopentane, 3-methoxypropylamine, and cyclohexyl. At least one selected from the group consisting of amines, n-butylamines, dimethylamines, diisopropylamines, piperidines, pyrrolidines, and 1,8-diazabicyclo [5.4.0] -7-undecene (DBU). Is preferable.

In the surface-treated silica filler of the present invention, the silica filler is a group consisting of a spherical silica powder obtained by reacting metallic silicon with oxygen, a spherical silica powder obtained by melting pulverized silica, and a pulverized silica product. It is preferable that it is at least one selected from.

Further, in the surface-treated silica filler of the present invention, it is preferable that the silica filler is obtained by at least one method selected from the group consisting of a sol-gel method, a precipitation method, and an aqueous solution wet method.

Further, the surface-treated silica filler of the present invention is preferably surface-treated with a basic substance having a pKa of 9.4 or more, and then further surface-treated with a silane coupling agent.

Further, in the surface-treated silica filler of the present invention, the silane coupling agent is selected from the group consisting of an epoxy-based silane coupling agent, an amine-based silane coupling agent, a vinyl-based silane coupling agent, and an acrylic-based silane coupling agent. It is preferable that the amount is at least one.

The present invention also provides a resin composition containing the surface-treated silica filler of the present invention.

The present invention also provides a semiconductor encapsulant containing the resin composition of the present invention.

The present invention also provides a one-component adhesive containing the resin composition of the present invention.

The present invention also provides an adhesive film produced by using the resin composition of the present invention.

The surface-treated silica filler of the present invention is surface-treated with a basic substance to neutralize the acidic silanol groups present on the surface of the silica filler. Since a basic substance having a pKa of 9.4 or more is used in the surface treatment of the silica filler, the basic substance that was chemically adsorbed on the acidic silanol groups present on the surface of the silica filler during the preliminary drying of the silica filler. Desorption of substances is suppressed.
Therefore, the pre-drying of the silica filler does not impair the action and effect of the neutralization treatment. As a result, it is possible to suppress an increase in viscosity when added to a resin composition used for applications such as semiconductor encapsulants. In addition, deterioration of the treated layer when the silica filler is surface-treated with a silane coupling agent can be suppressed.

FIG. 1 is a graph showing the relationship between the heat treatment time and pH at 150 ° C. heat treatment for silica fillers surface-treated with different basic substances. FIG. 2 is a graph showing the relationship between the heat treatment temperature and pH of silica fillers surface-treated with different basic substances. FIG. 3 is a graph showing the relationship between the heat treatment time and the pH in the 150 ° C. heat treatment when the initial pH is an acidic condition (pH is less than 7) for the silica filler surface-treated with different basic substances. is there.

Hereinafter, the present invention will be described in detail.
<Surface treatment silica filler>
The surface-treated silica filler of the present invention is surface-treated with a basic substance having an acid dissociation constant (pKa) of a conjugate acid of 9.4 or more.
The silica filler to be surface-treated is not particularly limited, and is used in applications such as semiconductor encapsulants, one-component adhesives used in the manufacture of electronic parts, and adhesive films used as NCF in semiconductor mounting. It can be widely applied to silica fillers added to the resin composition for the purpose of lowering the thermal expansion coefficient. Details of the silica filler to be surface-treated will be described later.

In the surface-treated silica filler of the present invention, the surface treatment with a basic substance is to neutralize the acidic silanol groups present on the surface of the silica filler with the basic substance. When the surface is treated with a basic substance, the basic substance is chemically adsorbed on the acidic silanol groups existing on the surface of the silica filler, and the silanol groups are neutralized.
In the surface-treated silica filler of the present invention, a basic substance having an acid dissociation constant (pKa) of 9.4 or more of the conjugate acid is used as the basic substance.
As a result of diligent studies on the ease of desorption of a basic substance chemically adsorbed on a silanol group during heating such as pre-drying of a silica filler, the inventor of the present application has found that the pKa of the basic substance has an effect. I found it. That is, it was found that a basic substance having a smaller pKa is more likely to be desorbed from a silanol group during heating, and a basic substance having a larger pKa is less likely to be desorbed from a silanol group during heating.

Then, it was found that in the case of the above-mentioned pre-drying condition of the silica filler, if the pKa is a basic substance of 9.4 or more, the elimination from the silanol group is suppressed.
Examples of basic substances having a pKa of 9.4 or more include benzylamine, 2-methoxyethylamine, 3-amino-1-propanol, 3-aminopentane, 3-methoxypropylamine, cyclohexylamine, n-butylamine and dimethyl. Included are amines, diisopropylamine, piperidine, pyrrolidine, 1,8-diazabicyclo [5.4.0] -7-undecene (DBU). Only one kind of these basic substances may be used, or two or more kinds thereof may be used in combination.
Among these, 3-methoxypropylamine, n-butylamine and pyrrolidine are preferable because they are liquid at room temperature and have appropriate volatility, and 3-methoxypropylamine and n-butylamine are more preferable.

The surface treatment method using a basic substance is appropriately selected according to the basic substance to be used. All of the basic substances exemplified above are liquids or gases at room temperature. Therefore, in a state where the basic substance and the silica filler are present in the same atmosphere, the atmosphere is heated to vaporize the basic substance, so that the basic substance is brought into contact with the surface of the silica filler in a gas phase to bring the silica filler into contact with the silica filler. Is preferable because it can be surface-treated.
When the basic substance is brought into contact with the surface of the silica filler in the gas phase according to the above procedure, the atmosphere is further heated, specifically, to the condition of pre-drying the silica filler described above. As a result, it is possible to remove the basic substance that has not been chemically adsorbed on the silanol group existing on the surface of the silica filler.
However, the above procedure shows an example of the surface treatment procedure with a basic substance, and the surface treatment procedure with a basic substance is not limited to this, and can be appropriately selected according to the basic substance to be used. it can. For example, when a basic substance having a large molecular weight and difficult to vaporize such as DBU is used, the surface of the silica filler surface may be surface-treated by immersing the silica filler in a solution containing the basic substance. Further, the surface of the silica filler may be surface-treated by spraying a solution containing a basic substance onto the silica filler.

The surface-treated silica filler of the present invention is preferably surface-treated with a basic substance and then further surface-treated with a silane coupling agent. Since a basic substance with a pKa of 9.4 or more is chemically adsorbed on the acidic silanol group existing on the surface of the silica filler, when the silica filler surface-treated with a silane coupling agent is heat-treated, the silanol group becomes basic. Desorption of substances is suppressed. Therefore, the silanol groups on the surface of the silica filler act as a catalyst to promote the hydrolysis of the alkoxide of the silane coupling agent and the cleavage of the epoxy groups contained in the epoxy-based silane coupling agent, and the effect of the surface treatment is impaired. There is no fear.

The silane coupling agent used for the surface treatment is not particularly limited, and is selected from the group consisting of an epoxy-based silane coupling agent, an amine-based silane coupling agent, a vinyl-based silane coupling agent, and an acrylic-based silane coupling agent. At least one can be used.
Among these, the epoxy-based silane coupling agent is preferable because of its affinity with the epoxy resin that is the main component of the semiconductor resin composition when the silica filler is added to the semiconductor resin composition and used.
Only one of these silane coupling agents may be used, or two or more of these silane coupling agents may be used in combination.

The surface treatment method with a silane coupling agent is not particularly limited, and can be carried out by, for example, a stirring method, a wet method, a dry method or the like.
The stirring method is a method in which a silane coupling agent and a silica filler are charged in a stirring device in advance and stirred under appropriate conditions. The stirring device includes a mixer capable of stirring and mixing at high speed, such as a Henschel mixer. It can be used, but is not particularly limited.
In the wet method, a silane coupling agent in an amount sufficient for the surface area of the silica filler to be surface-treated is dissolved in water or an organic solvent to prepare a surface treatment solution. Silica filler is added to the obtained surface treatment solution, and the mixture is stirred so as to form a slurry. After the silane coupling agent and the silica filler are sufficiently reacted by stirring, the silica filler is separated from the surface treatment solution by a method such as filtration or centrifugation, and dried by heating.
The dry method is a method in which a stock solution or a solution of a silane coupling agent is uniformly dispersed in a silica filler that is agitated at high speed by a stirrer. As the stirring device, a mixer capable of stirring and mixing at high speed such as a Henschel mixer can be used, but the stirring device is not particularly limited.
In addition to the above-mentioned stirring method, wet method, and dry method, for example, a silane coupling agent is directly added to a silica filler dispersion liquid in which a silica filler is dispersed in a resin or a solvent to modify the surface of the silica filler. The integral blending method can also be preferably used.

Hereinafter, the surface-treated silica filler of the present invention will be further described.
(Silica filler)
The silica filler to be surface-treated is not limited by the manufacturing method. Examples thereof include spherical silica powder obtained by reacting metallic silicon with oxygen, spherical silica powder obtained by melting pulverized silica, and pulverized silica.
Moreover, the silica filler obtained by the sol-gel method, the sedimentation method, and the aqueous solution wet method is exemplified.
Only one kind of these silica fillers may be used, or two or more kinds thereof may be used in combination.

The shape of the silica filler to be surface-treated is not particularly limited, and may be in any form such as granular, powdery, or shard. When the shape of the silica filler is other than granular, the average particle size of the silica filler means the average maximum diameter of the silica filler.
However, forming a substantially spherical shape with a sphericity of 0.8 or more improves the dispersibility of the silica filler in the liquid encapsulant and the injectability of the liquid encapsulant, and at the same time, the silica filler can be used. It is preferable from the viewpoint of getting closer to the most densely packed state. As used herein, "sphericity" is defined as "the ratio of the minimum diameter to the maximum diameter of a particle". For example, as a result of observation with a scanning electron microscope (SEM), the ratio of the minimum diameter to the maximum diameter observed may be 0.8 or more. The silica filler of the component (C) preferably has a sphericity of 0.9 or more.

The size of the surface-treated silica filler is not particularly limited, and as described below, it can be appropriately selected depending on the use of the surface-treated silica filler.

When a surface-treated silica filler is added to a resin composition and used as a semiconductor encapsulant, the average particle size of the silica filler is 0.05 to 80 μm, which means that the viscosity of the semiconductor encapsulant can be adjusted and the semiconductor. It is preferable from the viewpoint of injectability of the sealing material, prevention of void generation, etc., more preferably 0.1 to 15 μm, and further preferably 0.1 to 3 μm.
Further, in addition to the average particle size in the above range, it is more preferable to use one having an extremely uniform particle size distribution. Specifically, it is more preferable to use one having an average particle size of ± 0.2 μm and a particle size distribution of 90% or more of the whole.

When a surface-treated silica filler is added to the resin composition and used as a one-component adhesive used in the manufacture of electronic parts, the average particle size of the silica filler is preferably 0.007 to 10 μm. More preferably, it is 0.1 to 6 μm.

When the surface-treated silica filler is added to the resin composition and the adhesive film prepared by using the resin composition is used as NCF, the average particle size of the silica filler is 0.01 to 1 μm. Is preferable for the reason of spreadability to a narrow gap and transparency, and more preferably 0.05 to 0.3 μm.

<Resin composition>
Since the resin composition of the present invention is used as a semiconductor encapsulant, a one-component adhesive used in the manufacture of electronic components, and an adhesive film used as an NCF (Non Conductive Film) in semiconductor mounting, the above-mentioned surface Contains treated silica filler as an essential component.

The resin composition of the present invention contains a thermosetting resin because it is used as a semiconductor encapsulant, a one-component adhesive used in the manufacture of electronic components, and an adhesive film used as an NCF in semiconductor mounting. Is preferable.
The thermosetting resin contained in the resin composition of the present invention is not particularly limited, but is preferably liquid at room temperature (25 ° C.). Examples of the thermosetting resin include epoxy resin, (meth) acrylic resin, and maleimide resin.

The epoxy resin is a compound having one or more epoxy groups in the molecule, and the epoxy groups react with each other by heating to form a three-dimensional network structure and can be cured. From the viewpoint of cured product properties, it is preferable that two or more epoxy groups are contained in one molecule.

Epoxy resins include bisphenol compounds such as bisphenol A, bisphenol E, and bisphenol F or derivatives thereof (for example, alkylene oxide adducts), hydrogenated bisphenol A, hydrogenated bisphenol E, hydrogenated bisphenol F, cyclohexanediol, and cyclohexanedi. A bifunctional epoxy resin obtained by epoxidizing a diol having an alicyclic structure such as methanol or cyclohexanediethanol or a derivative thereof, an aliphatic diol such as butanediol, hexanediol, octanediol, nonanediol or decanediol or a derivative thereof. Trifunctional epoxy resin having a trihydroxyphenylmethane skeleton and an aminophenol skeleton; Examples thereof include polyfunctional epoxy resins obtained by epoxidizing phenol novolac resin, cresol novolac resin, phenol aralkyl resin, biphenyl aralkyl resin, naphthol aralkyl resin and the like. However, it is not limited to these.

The epoxy resin is preferably liquid at room temperature (25 ° C.) and can be liquid at room temperature alone or as a mixture. It can also be made liquid by using a reactive diluent, and examples of the reactive diluent include monofunctional aromatic glycidyl ethers such as phenylglycidyl ether and cresyl glycidyl ether, and aliphatic glycidyl ethers. Can be mentioned.

As the thermosetting resin, a (meth) acrylic resin can be used. The (meth) acrylic resin can be a compound having a (meth) acryloyl group in the molecule, and can be cured by forming a three-dimensional network structure by reacting the (meth) acryloyl group. Examples of the (meth) acrylic resin include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tarsal butyl (meth) acrylate, isodecyl (meth) acrylate, and lauryl (meth). Meta) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isoamyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. Alkyl (meth) acrylate, cyclohexyl (meth) acrylate, tertiary butylcyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (Meta) Acrylate, Trimethylol Propanetri (Meta) Acrylate, Zincmono (Meta) Acrylate, Zincdi (Meta) Acrylate, Dimethylaminoethyl (Meta) Acrylate, Diethylaminoethyl (Meta) Acrylate, Neopentyl Glycol (Meta) Acrylate, Tri Fluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 2,2,3,3,4,4-hexafluorobutyl (meth) acrylate, perfluorooctyl (meth) acrylate , Perfluorooctyl ethyl (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-Nonandiol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, methoxyethyl (meth) Acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxypolyalkylene glycol mono (meth) acrylate, octoxypolyalkylene glycol mono (meth) acrylate, lauroxypolyalkylene glycol mono (meth) acrylate, stearoxy Polyalkylene glycol mono (meth) acrylate, a Liloxypolyalkylene glycol mono (meth) acrylate, nonylphenoxypolyalkylene glycol mono (meth) acrylate, di (meth) acryloyloxymethyltricyclodecane, N- (meth) acryloyloxyethylmaleimide, N- (meth) acryloyloxy Examples thereof include ethylhexahydrophthalimide and N- (meth) acryloyloxyethylphthalimide. N, N'-methylenebis (meth) acrylamide, N, N'-ethylenebis (meth) acrylamide, 1,2-di (meth) acrylamide Ethylene glycol (meth) acrylamide can also be used. It is also possible to use vinyl compounds such as n-vinyl-2-pyrrolidone, styrene derivatives, and α-methylstyrene derivatives.

As the (meth) acrylic resin, poly (meth) acrylate can be used. As the poly (meth) acrylate, a copolymer of (meth) acrylic acid and (meth) acrylate or a copolymer of (meth) acrylate having a hydroxyl group and (meth) acrylate having no polar group is preferable. ..

Examples of the (meth) acrylic resin include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl (meth). Meta) acrylate, 4-hydroxybutyl (meth) acrylate, 1,2-cyclohexanediol mono (meth) acrylate, 1,3-cyclohexanediol mono (meth) acrylate, 1,4-cyclohexanediol mono (meth) acrylate, 1 , 2-Cyclohexanedimethanol mono (meth) acrylate, 1,3-cyclohexanedimethanol mono (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 1,2-cyclohexanediethanol mono (meth) acrylate, 1,3-Cyclohexanediethanol mono (meth) acrylate, 1,4-cyclohexanediethanol mono (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate, trimethylol propane mono (meth) acrylate, trimethyl propane Di (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, neopentyl glycol mono (meth) acrylate and other (meth) acrylates having hydroxyl groups and these hydroxyl groups. A (meth) acrylate having a carboxy group obtained by reacting a (meth) acrylate having a carboxy group with a dicarboxylic acid or a derivative thereof can also be used. Examples of the dicarboxylic acids that can be used here include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, and tetrahydrophthalic acid. , Hexahydrophthalic acid and derivatives thereof.

Maleimide resin can be used as the thermosetting resin. The maleimide resin is a compound containing one or more maleimide groups in one molecule, and the maleimide groups react with each other by heating to form a three-dimensional network structure and can be cured. For example, N, N'-(4,4'-diphenylmethane) bismaleimide, bis (3-ethyl-5-methyl-4-maleimidephenyl) methane, 2,2-bis [4- (4-maleimidephenoxy) phenyl. ] Examples include bismaleimide resins such as propane. More preferable maleimide resins are compounds obtained by the reaction of diamine dimerate with maleic anhydride, and compounds obtained by the reaction of maleimided amino acids such as maleimide acetic acid and maleimide caproic acid with polyols. The maleimided amino acid is obtained by reacting maleic anhydride with aminoacetic acid or aminocaproic acid, and the polyol is preferably a polyether polyol, a polyester polyol, a polycarbonate polyol, or a poly (meth) acrylate polyol, and has an aromatic ring. Those that do not contain are particularly preferable. Since the maleimide group can react with the allyl group, it is also preferable to use it in combination with the allyl ester resin. The allyl ester resin is preferably an aliphatic one, and particularly preferably a compound obtained by transesterification of a cyclohexanediallyl ester and an aliphatic polyol.

The resin composition of the present invention may contain the following components as optional components.

(Hardener)
The resin composition of the present invention may contain a curing agent for a thermosetting resin. Examples of the curing agent for the thermosetting resin include aliphatic amines, aromatic amines, dicyandiamides, dihydrazide compounds, acid anhydrides, phenol resins, etc., and when an epoxy resin is used as the thermosetting resin, it is suitable. Can be used.

Examples of the aliphatic amine include aliphatic polyamines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, m-xylenediamine and 2-methylpentamethylenediamine, isophoronediamine and 1,3-bisamino. Alicyclic polyamines such as methylcyclohexane, bis (4-aminocyclohexyl) methane, norbornenediamine, 1,2-diaminocyclohexane, N-aminoethylpiperazine, 1,4-bis (2-amino-2-methylpropyl) piperazine Examples thereof include piperazine-type polyamines such as. Examples of the aromatic amine include aromatic polyamines such as diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis (4-aminobenzoate), and polytetramethylene oxide-di-p-aminobenzoate. Can be mentioned.
Examples of the dihydrazide compound include carboxylic acid dihydrazides such as adipic acid dihydrazide, dodecanoic acid dihydrazide, isophthalic acid dihydrazide, and p-oxybenzoic acid dihydrazide. Acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenyl succinic anhydride, maleic anhydride and polybutadiene reactants, and maleic anhydride and styrene. Examples include polymers. As the phenol resin, a compound having two or more phenolic hydroxyl groups in one molecule can be used from the viewpoint of cured product characteristics, and the number of preferable phenolic hydroxyl groups is 2 to 5. When the range of the phenolic hydroxyl group is within this range, the viscosity of the resin composition can be controlled within an appropriate range. A more preferable number of phenolic hydroxyl groups in one molecule is two or three. Examples of such compounds include bisphenol F, bisphenol A, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol S, dihydroxydiphenyl ether, dihydroxybenzophenone, tetramethyl biphenol, etylidene bisphenol, and methyl ethilidenebis (methylphenol). ), Cyclohexylidene bisphenols, bisphenols such as biphenols and their derivatives, trifunctional phenols such as tri (hydroxyphenyl) methane and tri (hydroxyphenyl) ethane and their derivatives, phenols such as phenol novolac and cresol novolac. Examples of the compound obtained by reacting with formaldehyde include those having a main dinuclear body or trinuclear body and derivatives thereof.

A polymerization initiator such as a thermal radical polymerization initiator can be used as the curing agent for the thermosetting resin, and when a (meth) acrylic resin is used as the thermosetting resin, it can be preferably used. As the polymerization initiator, known ones can be used. Specific examples of the thermal radical polymerization initiator include methyl ethyl ketone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetone peroxide, and 1,1-bis (t-butyl peroxy) 3,3,5-trimethylcyclohexane. , 1,1-bis (t-hexyl peroxy) cyclohexane, 1,1-bis (t-hexyl peroxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,5-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, n-butyl 4,4-bis (t-butylperoxy) ) Valerate, 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, t-butylhydroperoxide, P-menthanhydroperoxide, 1 , 1,3,3-Tetramethylbutylhydroperoxide, t-hexylhydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, α, α' -Bis (t-butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexin-3, iso Butylyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, silicate peroxide, m-toluoil peroxide, benzoyl peroxide, diisopropylperoxydicarbonate, bis ( 4-t-Butylcyclohexyl) peroxydicarbonate, di-3-methoxybutylperoxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-sec-butylperoxydicarbonate, di (3-methyl-3) -Methoxybutyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, α, α'-bis (neodecanoyle peroxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1 , 3,3, -Tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneoate Decanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate , T-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5 5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylper Oxyacetate, t-hexyl peroxybenzoate, t-butyl peroxy-m-tolu oil benzoate, t-butyl peroxybenzoate, bis (t-butyl peroxy) isophthalate, t-butyl peroxyallyl monocarbonate, 3 , 3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone and the like. These may be used alone or in combination of two or more.

(Curing accelerator)
The resin composition of the present invention may contain a curing accelerator for a thermosetting resin. When an epoxy resin is used as the thermosetting resin, examples thereof include salts of imidazoles, triphenylphosphine and tetraphenylphosphine. Among them, 2-methylimidazole, 2-ethylimidazole 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole. , 2-C ₁₁ H ₂₃ -imidazole, imidazole compounds such as an adduct of 2-methylimidazole and 2,4-diamino-6-vinyltriazine are preferred. A modified imidazole compound can also be used, and an epoxy-imidazole adduct compound or an acrylate-imidazole adduct compound can be used. Commercially available epoxy-imidazole adduct compounds include, for example, Ajinomoto Fine-Techno's "Amicure PN-23", the company's "Amicure PN-40", Asahi Kasei's "Novacure HX-3721", and Fuji Kasei Kogyo. Examples thereof include "Fuji Cure FX-1000" manufactured by Fuji Cure. Examples of commercially available acrylate-imidazole adduct-based compounds include "EH2021" manufactured by ADEKA Corporation. "Novacure HX-3088" manufactured by Asahi Kasei Corporation can also be used.

The resin composition of the present invention may further contain components other than the above, if necessary.
Specific examples of such components include (silane coupling agents), metal complexes, leveling agents, colorants, ion trap agents, defoamers, antioxidants, flame retardants, colorants, boric acid compounds and the like. Agents and the like can be blended. When the resin composition of the present invention is used as an adhesive film, in addition to the above, a surface conditioner, a rheology adjuster, a plasticizer, a dispersant, a sedimentation inhibitor, an elastomer component and the like can be blended. The type and amount of each compounding agent are as usual.

The resin composition of the present invention can be produced by a conventional method. Specifically, the above-mentioned components are mixed and stirred to prepare. Mixing and stirring can be performed using a kneader, a Henschel mixer, a roll mill, a ball mill, or the like, but of course, the mixing and stirring is not limited to this. Even if each component is mixed at the same time, some components may be mixed first and the remaining components may be mixed later.
When the resin composition of the present invention is used as an adhesive film, the resin composition prepared in the above procedure is diluted with a solvent to form a varnish, which is applied to at least one side of a support, dried, and then supported. It can be provided as an adhesive film attached to the body or an adhesive film peeled off from the support.

The resin composition of the present invention has a problem that the PCT resistance is lowered when it is used as a semiconductor encapsulant, a one-component adhesive, or an adhesive film because the silica filler surface-treated by the above procedure is added. Can be prevented.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Surface treatment with a basic substance was carried out according to the following procedure.
A basic substance (3.6 mmol) is added to a silica filler (trade name: Admafine SO-E2 (Admatex Co., Ltd., average particle size: 0.5 μm); 2000 g) and heated in a container with a lid (basic). The temperature from the boiling point of the substance to 20 ° C. lower than the boiling point is a guide).
However, when the basic substance was ammonia, aqueous ammonia (2.0 mL) was added to the silica filler (2000 g), the lid was closed, and the mixture was heated for 1 hour. After that, the lid was opened and further heated to remove water and excess ammonia, and the pH was adjusted to the desired pH.
When the basic substance is DBU, a silica filler (2000 g) is dispersed in isopropanol, DBU (3.6 mmol) is added, and then centrifugation is performed, the supernatant is removed, and the precipitate is dried to obtain a sample. It was.
When the silica filler was trade name Sciqas (Sakai Chemical Industry Co., Ltd., average particle size 0.1 μm), the amount of the basic substance to be added was 10.0 mmol with respect to 2000 g of the silica filler.
The treated silica filler was placed in another container that was not sealed, heated in a dryer at 150 ° C. for a specified time, and the pH of the suspended water in which the silica filler was suspended in water was measured.
The pH was measured using a LAQUA Twin compact pH meter (HORIBA, Ltd.) after calibrating at two points. The silica filler sample and pure water were directly suspended in the flat surface sensor, and the values were read when they were stable. This was repeated 3 times and the average value was adopted as data.

（１）：水中の値、化学便覧基礎編 改定五版より
（２）：サンアプロ株式会社ホームページより
表および図１における記号は以下を意味する。
ＨＭＤＳ ：１，１，１，３，３，３−ヘキサメチルジシラザン
３ＭＯＰＡ：３−メトキシプロピルアミン
ＤＢＵ ：１，８−ジアザビシクロ［５．４．０］−７−ウンデセン
未処理と比較すると、塩基性物質で表面処理したサンプルは、シリカフィラーのｐＨが高くなった。但し、ｐＫａが９．４よりもはるかに低いアニリン、ピリジンで表面処理したサンプルは、表面処理直後でもシリカフィラーのｐＨが低く中和処理の効果が不十分だった。ｐＫａが９．４未満のアンモニア、ＨＭＤＳで表面処理したサンプルは、表面処理直後のシリカフィラーのｐＨは７以上であり中和処理の効果が確認されたが、１５０℃で２時間ないし４時間の加熱処理後のシリカフィラーのｐＨが著しく低下しており、加熱処理によりシラノール基から塩基性物質が脱離したことが確認された。
一方、ｐＫａが９．４以上のベンジルアミン、３ＭＯＰＡ、ｎ−ブチルアミン、ピロリジン、ＤＢＵで表面処理したサンプルは、１５０℃で２時間ないし４時間の加熱処理後でもシリカフィラーのｐＨの低下が少なく、加熱処理時におけるシラノール基からの塩基性物質の脱離が抑制されていることが確認された。なお、ピロリジンで表面処理したサンプルは、表面処理直後のシリカフィラーのｐＨが７よりも若干低いが、中和処理の効果は十分である。
シリカフィラーとしてＳｃｉｑａｓを使用したサンプルについては、塩基性物質として、ｐＫａが９．４未満のアンモニア、ｐＫａが９．４以上の３ＭＯＰＡで表面処理したが、上記と同様の関係が確認された。 The results are shown in Table 1 and FIG. 1 below.

(1): Values in water, from the 5th revised edition of the Basics of Chemistry Handbook (2): From the website of Sun Appro Co., Ltd.
HMDS: 1,1,1,3,3,3-hexamethyldisilazane 3MOPA: 3-methoxypropylamine DBU: 1,8-diazabicyclo [5.4.0] -7-Undecene Base compared to untreated Samples surface-treated with a sex substance had a higher pH of the silica filler. However, in the sample surface-treated with aniline and pyridine having a pKa much lower than 9.4, the pH of the silica filler was low even immediately after the surface treatment, and the effect of the neutralization treatment was insufficient. In the sample surface-treated with ammonia and HMDS having a pKa of less than 9.4, the pH of the silica filler immediately after the surface treatment was 7 or more, and the effect of the neutralization treatment was confirmed. It was confirmed that the pH of the silica filler after the heat treatment was remarkably lowered, and that the basic substance was desorbed from the silanol group by the heat treatment.
On the other hand, the samples surface-treated with benzylamine, 3MOPA, n-butylamine, pyrrolidine, and DBU having a pKa of 9.4 or more showed little decrease in the pH of the silica filler even after heat treatment at 150 ° C. for 2 to 4 hours. It was confirmed that the desorption of the basic substance from the silanol group during the heat treatment was suppressed. In the sample surface-treated with pyrrolidine, the pH of the silica filler immediately after the surface treatment is slightly lower than 7, but the effect of the neutralization treatment is sufficient.
The sample using Sciqas as the silica filler was surface-treated with ammonia having a pKa of less than 9.4 and 3MOPA having a pKa of 9.4 or more as basic substances, and the same relationship as described above was confirmed.

For untreated and surface-treated samples with ammonia, 3MOPA, pyrrolidine, and DBU, the heat treatment temperature was changed to 150 ° C., 165 ° C., and 180 ° C. for 2 hours, and the pH before and after the heat treatment was applied. Was measured. The results are shown in Table 2 and FIG. 2 below. In Table 2 and FIG. 2 below, those described as unheated in the heat treatment column indicate the pH before the heat treatment. In this case as well, the same relationship as above was confirmed.

For untreated and surface-treated samples with ammonia, 3MOPA, and pyrrolidine, the pH of the silica filler immediately after the surface treatment is acidic (pH is 7) in order to eliminate the influence of the difference in pH of the silica filler immediately after the surface treatment. It was adjusted to be less than (less than), and heat treatment at 150 ° C. was carried out. The results are shown in Table 3 below. In this case as well, the same relationship as above was confirmed.

ｐＫａが９．４未満のアンモニア、ＨＭＤＳで表面処理したサンプルは、１５０℃４時間加熱処理後のシリカフィラーのｐＨが低く、加熱処理後のエポキシ基残存率も低かった。
一方、ｐＫａが９．４以上のベンジルアミン、３ＭＯＰＡ、ｎ−ブチルアミン、ピロリジン、ＤＢＵと接触させたサンプル、および、シリカフィラーとしてＳｃｉｑａｓを使用し、３ＭＯＰＡと接触させたサンプルは、１５０℃４時間加熱処理後のシリカフィラーのｐＨが高く、加熱処理後のエポキシ基残存率も高かった。 For samples surface-treated with ammonia, HMDS, benzylamine, 3MOPA, n-butylamine, pyrrolidine, DBU, and samples surface-treated with 3MOPA using Sciqas as a silica filler, a silane coupling agent is further followed in the following procedure. Surface treatment was carried out with.
A silica filler (2000 g) in contact with a basic substance is placed in a mixer, and an isopropanol solution of an epoxy-based silane coupling agent is added while stirring at high speed (Shin-Etsu Chemical Co., Ltd. KBM-403 (3-glycidoxypropyltrimethoxysilane)). 20.0 g was dissolved in 32.0 g of isopropanol before use) was sprayed.
This was transferred to a vat and heated with appropriate stirring to remove isopropanol to obtain a sample surface-treated with a silane coupling agent.
The obtained sample was heated in a dryer at 150 ° C. for 4 hours, and the pH when suspended in water was measured.
In addition, the residual rate of epoxy groups on the surface of the silica filler before and after the heat treatment was calculated by the procedure shown below.
The number of moles of epoxy groups present on the surface per 1 g of the silica filler was determined in accordance with JIS-K-7236 "How to determine the epoxy equivalent of an epoxy resin". The epoxy group residual ratio after the heat treatment was the ratio of the amount of epoxy groups before and after the heat treatment at 150 ° C. for 4 hours.
The results are shown in Table 4 below.

In the sample surface-treated with ammonia and HMDS having a pKa of less than 9.4, the pH of the silica filler after the heat treatment at 150 ° C. for 4 hours was low, and the residual rate of the epoxy group after the heat treatment was also low.
On the other hand, a sample contacted with benzylamine having a pH of 9.4 or more, 3MOPA, n-butylamine, pyrrolidine, and DBU, and a sample contacted with 3MOPA using Sciqas as a silica filler were heated at 150 ° C. for 4 hours. The pH of the silica filler after the treatment was high, and the residual rate of epoxy groups after the heat treatment was also high.

(Non-silane coupling agent surface treatment filler compounding system (integral blend method))
For the silica filler surface-treated with ammonia, HMDS, 3MOPA, and DBU, a sample heat-treated at 150 ° C. for 4 hours was blended as a preliminary drying, and a silane coupling agent was separately added (integral blend method) to prepare a resin composition. did.
The mixing ratio of each component is as shown below.
Epoxy resin: 35.3 wt. %
(Bisphenol F type epoxy resin, product name YDF-8170, Nippon Steel & Sumikin Chemical Co., Ltd.)
Hardener: 14.2 wt. %
(Amine-based curing agent, product name KAYAHARD AA, Nippon Kayaku Co., Ltd.)
Non-silane coupling agent Surface treatment Silica filler: 50.0 wt. %
Silane coupling agent: 0.5 wt. %
(Product name KBM-403, Shin-Etsu Chemical Co., Ltd.)
Total: 100.0 wt. %
After mixing and dispersing each component with a hybrid mixer, vacuum defoaming was performed to prepare a resin composition for evaluation.
Further, for the untreated silica filler which has not been surface-treated with a basic substance, a resin composition was prepared by the above procedure.
For untreated silica fillers that have not been surface-treated with basic substances and samples that have been surface-treated with 3MOPA, methacrylic silane coupling agents (product name KBM) are used instead of KBM-403 as silane coupling agents. A resin composition containing −503 (3-methacrylopropylmethoxysilane), Shin-Etsu Chemical Co., Ltd.) was prepared.

(Silane coupling agent surface treatment filler compounding system)
The silica filler surface-treated with ammonia, HMDS, 3MOPA, and DBU was surface-treated with a silane coupling agent according to the above procedure, and a resin composition containing a sample heat-treated at 150 ° C. for 4 hours was prepared as pre-drying. ..
The mixing ratio of each component is as shown below.
Epoxy resin: 35.3 wt. %
(Bisphenol F type epoxy resin, product name YDF-8170, Nippon Steel & Sumikin Chemical Co., Ltd.)
Hardener: 14.2 wt. %
(Amine-based curing agent, product name KAYAHARD AA, Nippon Kayaku Co., Ltd.)
Silane coupling agent Surface treatment Silica filler: 50.5 wt. %
Total: 100.0 wt. %
After mixing and dispersing each component with a hybrid mixer, vacuum defoaming was performed to prepare a resin composition for evaluation.
Further, the untreated silica filler which has not been surface-treated with a basic substance is also surface-treated with a silane coupling agent according to the above procedure, and a resin composition containing a silica filler which has been heat-treated at 150 ° C. for 4 hours as pre-drying. Was prepared.
For untreated silica fillers that have not been surface-treated with basic substances and samples that have been surface-treated with 3MOPA, methacrylic silane coupling agents (product name KBM) are used instead of KBM-403 as silane coupling agents. A resin composition containing −503 (3-methacrylopropylmethoxysilane), Shin-Etsu Chemical Co., Ltd.) was prepared.

（１）：樹脂組成物の増粘が著しく、粘度計の上限を超えてしまったために測定不可。

非シランカップリング剤表面処理フィラーを配合し、シランカップリング剤を別添加（インテグラルブレンド法）した樹脂組成物、およびシランカップリング剤表面処理フィラーを配合した樹脂組成物、どちらの樹脂組成物においても、ｐＫａが９．４未満のアンモニアやＨＭＤＳで表面処理したサンプルは、塩基性物質で表面処理していない未処理のシリカフィラーを配合した樹脂組成物のように粘度が高くなった。これに対し、ｐＫａが９．４以上の３ＭＯＰＡやＤＢＵで表面処理したサンプルは、塩基性物質で表面処理していない未処理のシリカフィラーを配合した樹脂組成物に比べて、樹脂組成物の粘度が大幅に低減された。この点については、メタクリル系シランカップリング剤（ＫＢＭ−５０３）で表面処理したサンプルも同様である。 The evaluation shown below was carried out using the obtained resin composition for evaluation. The results are shown in Table 5 below.
The pH in Table 5 shows the value of the pH when each silica filler used for preparing the resin composition was suspended in water.
(Viscosity of resin composition)
With a rotational viscometer (Brookfield viscometer DV-1), the measurement was performed at a liquid temperature of 25 ° C. while rotating the spindle at 50 rpm.

(1): The thickening of the resin composition was remarkable, and the measurement was not possible because the upper limit of the viscometer was exceeded.

A resin composition containing a non-silane coupling agent surface treatment filler and separately added with a silane coupling agent (integral blend method), or a resin composition containing a silane coupling agent surface treatment filler. In addition, the sample surface-treated with ammonia having a pKa of less than 9.4 or HMDS had a high viscosity like a resin composition containing an untreated silica filler which had not been surface-treated with a basic substance. On the other hand, the sample surface-treated with 3MOPA or DBU having a pKa of 9.4 or more has a viscosity of the resin composition as compared with the resin composition containing an untreated silica filler which has not been surface-treated with a basic substance. Was significantly reduced. In this regard, the same applies to the sample surface-treated with the methacrylic silane coupling agent (KBM-503).

The present invention is a surface treatment compounded in a semiconductor encapsulant, a one-component adhesive used in the manufacture of electronic parts, and a resin composition used as an adhesive film used as an NCF (Non Conductive Film) in semiconductor mounting. The present invention relates to a silica filler, a method for producing the same , and a resin composition containing the surface-treated silica filler.

In order to achieve the above object, in the present invention, the acid dissociation constant (pKa) of the conjugated acid is 9.4 or more, and the acidic silanol group existing on the surface of the silica filler is subjected to the surface treatment with the pKa. Is a surface-treated silica filler on which a basic substance of 9.4 or more is chemically adsorbed, and the pH of the surface of the silica filler surface after heating the surface-treated silica filler at 150 ° C. for 4 hours is 5.3 to 7.8. Provided is a surface-treated silica filler.

In the surface-treated silica filler of the present invention, the basic substances having a pKa of 9.4 or more are benzylamine, 2-methoxyethylamine, 3-amino-1-propanol, 3-aminopentane, 3-methoxypropylamine, and cyclohexyl. At least one selected from the group consisting of amines, n-butylamines, dimethylamines, diisopropylamines, piperidines, pyrrolidines, and 1,8-diazabicyclo [5.4.0] -7-undecene (DBU). Is preferable, and at least one selected from the group consisting of benzylamine, 3-methoxypropylamine, and pyrrolidine is more preferable.

Further, in the surface-treated silica filler of the present invention, the sphericity of the silica filler is preferably 0.8 or more.
Further, the surface-treated silica filler of the present invention is preferably mixed with the resin after pre-drying.

The present invention also provides a method for producing a surface-treated silica filler of the present invention, in which the surface treatment is performed with a basic substance having a pKa of 9.4 or more, and then the surface is further treated with a silane coupling agent.
In the method for producing a surface-treated silica filler of the present invention, the silane coupling agent comprises a group consisting of an epoxy-based silane coupling agent, an amine-based silane coupling agent, a vinyl-based silane coupling agent, and an acrylic-based silane coupling agent. It is preferably at least one selected.

Claims (10)

A surface-treated silica filler characterized in that the acid dissociation constant (pKa) of a conjugate acid is surface-treated with a basic substance of 9.4 or more. The basic substances having a pKa of 9.4 or more are benzylamine, 2-methoxyethylamine, 3-amino-1-propanol, 3-aminopentane, 3-methoxypropylamine, cyclohexylamine, n-butylamine, dimethylamine, and the like. The surface-treated silica according to claim 1, which is at least one selected from the group consisting of diisopropylamine, piperidine, pyrrolidine, and 1,8-diazabicyclo [5.4.0] -7-undecene (DBU). Filler. The silica filler is at least one selected from the group consisting of spherical silica powder obtained by reacting metallic silicon with oxygen, spherical silica powder obtained by melting pulverized silica, and pulverized silica product. , The surface-treated silica filler according to claim 1 or 2. The surface-treated silica filler according to any one of claims 1 to 3, wherein the silica filler is obtained by at least one method selected from the group consisting of a sol-gel method, a sedimentation method, and an aqueous solution wet method. The surface-treated silica filler according to any one of claims 1 to 4, wherein the surface treatment is performed with a basic substance having a pKa of 9.4 or more, and then the surface is further treated with a silane coupling agent. 5. The silane coupling agent is at least one selected from the group consisting of an epoxy-based silane coupling agent, an amine-based silane coupling agent, a vinyl-based silane coupling agent, and an acrylic-based silane coupling agent. The surface-treated silica filler described in 1. A resin composition containing the surface-treated silica filler according to any one of claims 1 to 6. A semiconductor encapsulant containing the resin composition according to claim 7. A one-component adhesive containing the resin composition according to claim 7. An adhesive film containing the resin composition according to claim 7.

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