JP2016079368A - Low thermal expandable resin composition and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition consisting of an inorganic filler having excellent low thermal expandable property and an organic resin independent from specific organic resin matrix species.SOLUTION: The low thermal expandable resin composition is a resin composition by uniformly dispersing an ultra fine inorganic filler having average primary particle diameter of 1 to 50 nm (B) at its primary particle diameter level and further dispersing an inorganic filler having average particle diameter of 0.3 to 50 μm in an organic resin matrix (A) consisting of a curable resin (A1) or a thermoplastic resin (A2), where the blended amount of the ultra fine inorganic filler (B) is 2 to 30 mass% based on the resin matrix (A) and the total amount of the inorganic component combining the ultra fine inorganic filler (BI) and the inorganic filler (C) is 60 to 95 mass% of the resin composition.SELECTED DRAWING: None

Description

  The present invention relates to a material that exhibits low linear expansion by a mixture of an organic resin and an inorganic filler among various materials having low linear expansion characteristics.

  Typical semiconductor devices such as diodes, transistors, ICs, LSIs, and the like are manufactured as semiconductor devices by sealing members such as semiconductor chips and substrates with an organic resin sealing material made of a thermosetting resin. . The combination of an organic resin matrix for expressing moldability and a large amount of inorganic filler that can ignore thermal deformation even at high temperatures is intended to reduce the thermal expansion of the entire resin composition (for example, patents) Reference 1).

  However, even such a low thermal expansion resin composition has been found to cause various troubles due to the magnitude of thermal expansion when placed in a severer high temperature environment. As an easy-to-understand example, a semiconductor element incorporated in a large current circuit typified by a power transistor also generates a large amount of heat during driving, and the entire semiconductor device is exposed to high temperatures. Therefore, while measures to increase heat dissipation are required for the encapsulant composition, measures to reduce thermal expansion deformation of the encapsulant due to the amount of heat accumulated in the semiconductor device itself due to imbalance between the amount of heat generated and the amount of heat released. Is also required. In fact, due to thermal deformation, which is mainly caused by the thermal expansion of the organic resin matrix in the organic resin encapsulant, peeling or cracking occurs at the interface between the semiconductor element and the organic resin matrix component, and the effect of moisture The effect will be reduced.

  There are two ways to suppress thermal expansion deformation in a high temperature environment. The chemical structure of the resin matrix component is selected from the most rigid ones and at the same time the crosslink density is increased (for example, see Patent Document 2), and the use of semiconductor devices. A large amount of an inorganic component having an extremely low thermal expansion coefficient under the environment is filled (see, for example, Patent Documents 3 and 4). However, the selection of the former must also take into account other characteristics that require countermeasures from the chemical structural aspect, such as improving moldability and tracking resistance. On the other hand, as for inorganic filling, the filling amount is almost at the upper limit from the balance with moldability and other factors, and the degree of design freedom of the low thermal expansion resin composition is not necessarily high. Although the linear expansion coefficient reduction by the inorganic nanoparticle polymer composite is reported as the direction of modification, the effect of the nanoparticle combination is limited, and there is still room for further improvement (Non-patent Document 1). ). There is a need for a technique for expressing superior low thermal expansion characteristics while maintaining the flexibility of selection of various resin matrix species.

JP 2000-327884 A JP 2012-62448 A JP-A-10-158366 JP 2013-127710 A

Published by Toray Research Center "Organic-inorganic hybrid and organization (2005)"

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a resin composition having more excellent low thermal expansion characteristics without depending on a specific organic resin matrix species.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a resin composition having low thermal expansion characteristics by allowing nano-order ultrafine inorganic fillers to coexist with conventional micron-order inorganic particles. I found out that it can be provided.
That is, the present invention comprises the following technical means.

[1] A resin composition comprising an inorganic filler and an organic resin,
In the organic resin matrix (A) made of the curable resin (A1) or the thermoplastic resin (A2), the ultrafine inorganic filler (B) having an average primary particle size of 1 to 50 nm is uniform at the primary particle size level. An organic resin composition in which an inorganic filler (C) having an average particle size of 0.3 to 50 μm is dispersed, and the blending amount of the ultrafine inorganic filler (B) is a resin. It is 2-30 mass% with respect to a matrix (A), and the sum total of the inorganic component combined with the ultrafine inorganic filler (B) and the inorganic filler (C) is 60-95 mass% of the said resin composition. A low thermal expansion resin composition characterized by being.
[2] Primary particles of the ultrafine inorganic filler (B) and / or inorganic filler (C) constitute a curable resin (A1) or a thermoplastic resin (A2) that forms the organic resin matrix (A). One or more of chemical structure and electrostatic interaction, van der Waals interaction, hydrogen bonding interaction, π / π stacking interaction, coordination bond force, charge transfer interaction and hydrophobic effect The low thermal expansion resin composition according to claim 1, further comprising a surface treatment portion capable of generating an attractive force through interaction.
[3] The fine inorganic filler (B) having an average primary particle size of 1 to 50 nm is mixed and uniformly dispersed in a solution in which the monomer that forms the curable resin (A1) is dissolved in a solvent. Thereafter, a fine inorganic filler-containing organic resin matrix is obtained by pulverizing the solid material from which the solvent has been removed to form a powder, and the curable resin (A1) is formed on the fine inorganic filler-containing organic resin matrix. A monomer that forms a curable resin different in kind from the curable resin (A1), an inorganic filler (C) having an average particle diameter of 3 to 50 μm, and a curing catalyst are added, melt-mixed, and then molded. A method for producing a low thermal expansion resin composition.
[4] In a solution obtained by dissolving the thermoplastic resin (A2) in a solvent, the fine inorganic filler (B) having an average primary particle diameter of 1 to 50 nm is mixed and uniformly dispersed, and then the solvent is added. A fine inorganic filler-containing organic resin matrix is formed by pulverizing the removed solid material into a powder form, and the fine inorganic filler-containing organic resin matrix has an inorganic filler having an average particle diameter of 0.3 to 50 μm ( A method for producing a low thermal expansion resin composition, comprising adding C) and the additional thermoplastic resin (A2), mixing in a molten state, and then molding.
A method for producing an expandable resin composition.

  By using an inorganic filler having two kinds of large and small average particle diameters and applying an appropriate surface treatment to each, the organic resin composition is formed, so that the thermal expansion characteristics are extremely small after molding, and the heat resistance is excellent. An encapsulant can be obtained. Applications that require such performance, especially power semiconductor encapsulants that require a large amount of heat and high heat resistance, as well as resin encapsulated diodes, transistors, ICs, LSIs, super LSIs, and other packages It can be used suitably.

  Hereinafter, the low thermal expansion resin composition of the present invention will be described in detail.

[Organic resin matrix (A) (curable resin or thermoplastic resin)]
The curable resin (A1) used in the present invention is not particularly limited. What is necessary is that polymerization is started by an external trigger such as heat and light, the molecular weight is increased, and a resin is formed. For example, acrylic resin, methacrylic resin, phenol resin, urea resin, melamine resin, polyurethane resin, epoxy resin and the like can be exemplified.
As the organic resin matrix, an epoxy resin having a great track record in the semiconductor field among these can be said to be suitable for the present invention.
Examples of the epoxy resin include novolak type epoxy resin, cresol novolak type epoxy resin, triphenolalkane type epoxy resin, aralkyl type epoxy resin, biphenyl skeleton-containing aralkyl type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, Multifunctional epoxy resin, heterocyclic epoxy resin, naphthalene ring-containing epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, stilbene type epoxy resin, etc. are used, and one or more of these are used in combination May be.

When the curable resin (A1) is used as the organic resin matrix (A), a curing agent may be necessary. What is necessary is just to use each hardening | curing agent normally used for curable resin as a hardening | curing agent.
Examples of curing agents combined with epoxy resins include phenol novolac resins, naphthalene ring-containing phenol resins, phenol aralkyl type phenol resins, aralkyl type phenol resins, biphenyl skeleton-containing aralkyl type phenol resins, biphenyl type phenol resins, dicyclopentadiene. Type phenol resin, alicyclic phenol resin, heterocyclic phenol resin, phenol resin containing naphthalene ring, phenol resin such as bisphenol A, bisphenol F, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, Examples include acid anhydrides such as methylhymic anhydride, and one or more of these may be used in combination.
Although there is no restriction | limiting in particular about the compounding ratio of an epoxy resin and a hardening | curing agent, The molar ratio of the phenolic hydroxyl group or acid anhydride group contained in a hardening | curing agent is 0 with respect to 1 mol of epoxy groups contained in an epoxy resin. It is desirable to be in the range of .5 to 1.5, preferably 0.8 to 1.2. Furthermore, you may add a hardening accelerator suitably.

  The thermoplastic resin (A2) used in the present invention is not particularly limited, but the melt processing temperature affects the purpose of use (for example, the structure and characteristics of the semiconductor element itself and the lead wire in the case of a semiconductor sealing material). It is necessary to select the most appropriate one in consideration of the influence. Specific examples include polyester resins, polyamide resins, polycarbonate resins, polycarbonate resins, polyether resins, and the like. It is desirable to appropriately adjust the molecular weight of the thermoplastic resin (A2) in consideration of uniform mixing with the ultrafine inorganic filler (C) described later.

[Ultra fine inorganic filler (B)]
Although the ultrafine inorganic filler (B) used for this invention is not specifically limited, The primary particle diameter needs to exist in the range of 5-50 nm, Furthermore, it is 5-15 nm. desirable. The primary particle diameter means the minimum unit constituting the geometric form of the ultrafine inorganic filler (B) dispersed in a powder or a solvent. For example, the arbitrary particle size of the low thermal expansion resin composition molded article of the present invention It is evaluated by a peak top value by direct measurement of a particle image in a transmission electron microscope (TEM) observation on a cross section of the particle size or measurement of particle size distribution based on dynamic light scattering. The ultrafine inorganic filler (B) may have a spherical shape or a polyhedron shape, or may have an anisotropic form such as a fiber shape or a scale shape (sheet shape) on a spindle. In the case of an anisotropic form, the primary particle diameter in the present invention is represented by the short axis diameter of the ultrafine inorganic filler (B) exposed on the observation surface. Regardless of the shape, the primary particle diameter of 100 ultrafine inorganic fillers (B) exposed on the observation surface is read and defined by the arithmetic average thereof.

  Specific examples of the ultrafine inorganic filler (B) include silica, alumina, zinc oxide, yttria, tin oxide, titania, iron oxide (hematite), copper oxide, cobalt oxide, selenium oxide, bismuth oxide (bismite), and the like. There can be mentioned metal oxide materials which can form fine particles synthetically. Silica and alumina are preferably used from the viewpoint of availability and particle size control.

  The ultrafine inorganic filler (B) material needs to be uniformly dispersed in the organic resin matrix (A) of the low thermal expansion resin composition of the present invention. Uniform dispersion means that the raw material primary particle diameter is maintained and mixed in the matrix without forming an aggregate, and to obtain the effect of the present invention, the primary particle diameter is uniformly dispersed. is necessary. In such a state, the surface area of the entire ultrafine inorganic particles (B) becomes extremely large, and the interfacial contact area with the resin component is large, while the average interparticle distance is also shortened. It can be expected that molecular motion is restrained and thermal expansibility is greatly reduced.

The ultrafine inorganic filler (B) is preferably modified on the surface thereof with a chemical group having some attractive interaction with the organic resin matrix component (A) of the low thermal expansion resin composition. Although the kind of such chemical groups is not limited, the chemical structure of the molecule constituting the curable resin (A1) or the thermoplastic resin (A2) constituting the resin matrix component (A), electrostatic interaction, fan It is necessary to be a chemical group that interacts with any one of Delwals interaction, hydrogen bonding interaction, π / π stacking interaction, coordination bond force, charge transfer interaction, or hydrophobic effect.
Specific interactive groups include alkyl groups, branched alkyl groups, long chain alkyl groups, phenyl groups, carbonyl groups (carboxyl groups, ester groups, aldehyde groups, ketone groups), acetal groups, hydroxyl groups, amino groups (amides) Group), imino group, nitrile group, phenyl group, cyclohexyl group, quaternary ammonium group, epoxy group, acid anhydride group, sulfonic acid group, thiol group, sulfide group, nitrile group, azo group, etc. It is a chemical group or salt having at least one of these.

  On the other hand, in order to modify the interaction group on the surface of the ultrafine inorganic filler (B), the surface of the ultrafine inorganic filler (B) on the side opposite to the interaction group with the organic resin matrix (A). It is necessary to have a chemical structure that can be bound to. For this purpose, a silane coupling agent having a methoxy group or an ethoxy group is preferably used. When surface modification with a silane coupling agent is carried out, it is made to react with the ultrafine inorganic filler (B) according to various known procedures. In order to easily control the reaction at the primary particle level, the silane cup is used. A method in which an aqueous solution in which a ring agent is sufficiently hydrolyzed in advance is prepared and mixed with a filler, followed by sufficient stirring and coating is preferable. Thereafter, the filler is collected by filtration, and if possible, it may be made into a sol using an appropriate solvent so that it can be easily used when preparing the low thermal expansion resin composition described later.

  The surface coating of the ultrafine inorganic filler (B) with such a chemical group is desirably covered with a thickness equivalent to one chemical group, and if the thickness is more than that, the effect of the present invention is hardly exhibited. On the other hand, when the coating amount is excessively small, it becomes difficult to uniformly disperse the ultrafine inorganic filler (B) in the resin matrix (A) with a primary particle size.

[Inorganic filler (C)]
Although the inorganic filler (C) used for this invention is not specifically limited, The particle diameter needs to exist in the range of 0.3-50 micrometers, and it is desirable that it is 5-15 micrometers further. . The shape may be a spherical shape or a polyhedron, or may be an anisotropic form such as a fiber shape or a scale shape (sheet shape) on a spindle. The geometric shape of the raw material powder or the inorganic filler (C) present in the sol can be directly observed with a scanning electron microscope (SEM) or the like. The average particle diameter in the present invention is a value that can be measured as a cumulative mass average value (or median diameter) in the dynamic light scattering particle size distribution measurement.

Specific examples of the inorganic filler (C) include silicas such as amorphous silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitrite, titanium oxide, glass fiber, and the like. Silicas and alumina are preferably used from the viewpoint of particle size control.
The inorganic filler (C) may be uniformly mixed with a composition in which the organic resin matrix (A) and the ultrafine inorganic filler (B) of the low thermal expansion resin composition of the present invention are uniformly dispersed. is necessary. Homogeneous mixing means mixing with the matrix without forming aggregates. In such a state, the inorganic particle component ratio is uniform regardless of the portion of the low thermal expansion resin composition, and the volume of the organic resin matrix (A) component existing between the inorganic particle components is reduced. The entire low thermal expansion resin composition can be uniformly thermally deformed, and as a result, the observed overall thermal expansion is also reduced.

The inorganic filler (C) is preferably modified on its surface with a chemical group having some attractive interaction with the organic resin matrix (A) component of the low thermal expansion resin composition. Although the kind of such chemical groups is not limited, the chemical structure of the molecule constituting the curable resin (A1) or the thermoplastic resin (A2) constituting the resin matrix component (A), electrostatic interaction, fan It is necessary to be a chemical group that interacts with any one of Delwals interaction, hydrogen bonding interaction, π / π stacking interaction, coordination bond force, charge transfer interaction, or hydrophobic effect.
Specific interactive groups include alkyl groups, branched alkyl groups, long chain alkyl groups, phenyl groups, carbonyl groups (carboxyl groups, ester groups, aldehyde groups, ketone groups), acetal groups, hydroxyl groups, amino groups (amides) Group), imino group, nitrile group, phenyl group, cyclohexyl group, quaternary ammonium group, epoxy group, acid anhydride group, sulfonic acid group, thiol group, sulfide group, nitrile group, azo group, etc. It is a chemical group or salt having at least one of these.

  For modification of the surface of the inorganic filler (C) with the interaction group, which is performed as necessary, the surface of the inorganic filler (C) on the side opposite to the interaction group with the organic resin matrix (A) It is made by a chemical group with a chemical structure that can be bound. For this purpose, a silane coupling agent having a methoxy group or an ethoxy group is preferably used. When surface modification with a silane coupling agent is carried out, it is made to react with the ultrafine inorganic filler (B) according to various known procedures. In order to easily control the reaction at the primary particle level, the silane cup is used. A method in which an aqueous solution in which a ring agent is sufficiently hydrolyzed in advance is prepared and mixed with a filler, followed by sufficient stirring and coating is preferable. Thereafter, the filler is collected by filtration, dried, and coarsely pulverized, and used in the preparation of a low thermal expansion resin composition described below.

  The surface coating of the inorganic filler (C) with such a chemical group is desirably covered with a thickness equivalent to one chemical group, and if the thickness is larger than that, the effect of the present invention is hardly exhibited. On the other hand, when the coating amount is excessively small, the adhesiveness between the inorganic filler (C) and the resin matrix (A) is lowered, and the effects of the present invention are hardly exhibited.

[Low thermal expansion resin composition]
In the low thermal expansion resin composition of the present invention, the ultrafine inorganic filler (B) is blended in an amount of 2 to 30% by mass with respect to the organic resin matrix (A), and an inorganic material combined with the inorganic filler (C). It is necessary that the total amount of the components is 60 to 95% by mass of the resin composition. If the blending amount of the ultrafine inorganic filler (B) is less than 2% by mass, the effect of low thermal expansion cannot be obtained by blending the ultrafine inorganic filler (B). Since the fluidity | liquidity of a fine inorganic filler containing organic resin matrix (A) component falls so that the mixing process with (C) will be obstructed, it is unpreferable. Further, if the total amount of inorganic components including the inorganic filler (C) is less than 60% by mass, the effect of reducing the thermal expansion of the entire low thermal expansion resin composition becomes insufficient, and the ultrafine inorganic filler (B) is not blended. The difference with the conventional product becomes scarce. On the other hand, if it exceeds 95% by mass, the moldability due to the organic component is lowered, and it is not preferable because it becomes difficult to form a molded product of the low thermal expansion resin composition.

[Other ingredients]
In the low linear expansion resin composition of the present invention, additives can be blended as necessary within a range not impairing the characteristics. Examples of the additive include an antioxidant, an ultraviolet absorber, a stabilizer, a light stabilizer, a compatibilizer, an adhesion aid, a fluidity modifier, and a lubricant.

  Examples of the antioxidant preferably used in the present invention include 2,6-di-tert-butyl-4-methylphenol and n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4-hydroxy). Phenyl) propionate, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), triethylene glycol-bis- [3- (3-tert-butyl-4hydroxy-5-methylphenyl) propionate], 3,9- Bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2, , 8,10-tetraoxaspiro [5,5] undecane, 4-4-thiobis- (2-tert-butyl-5-methylphenol), 2,2-methylenebis- (6-tert-butylmethylphenol), 4,4-methylenebis- (2,6-di-t-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene , Trisnonylphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, distearyl pentaerythritol phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol phosphite, Bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol phosphite, 2,2-methylenebis (4,6-di-t-butylphenol) L) Octyl phosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thio Dipropionate, pentaerythritol tetrakis (3-laurylthiopropionate), 2,5,7,8-tetramethyl-2- (4,8,12-trimethyldecyl) chroman-2-ol, 5,7 -Di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one, 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl]- 4,6-dipentylphenyl acrylate, 2-t-pentylphenyl) ethyl] -4,6-dipentylphenyl acrylate, 2-t-butyl-6- (3-t-butyl 2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, tetrakis (methylene) -3- (dodecylthiopropionate) methane, and the like.

  Stabilizers preferably used in the present invention include lithium stearate, magnesium stearate, calcium stearate, barium stearate, zinc stearate, calcium laurate, barium laurate, zinc laurate, calcium linoleate, barium ricinoleate, Metal soaps such as zinc ricinoleate, other organic tin stabilizers such as laurate, malate and mercapro, lead stabilizers such as lead stearate and tribasic lead sulfate, epoxy compounds such as epoxidized vegetable oil, Phosphite compounds such as alkyl allyl phosphites and trialkyl phosphites, β-diketone compounds such as dibenzoylmethane and dehydroacetic acid, polyols such as sorbitol, mannitol, pentaerythritol, hydrotalcites and zeora Mention may be made of a door class.

In the present invention, various alkoxysilanes, silane coupling agents, titanate coupling agents and the like are suitably used as the adhesion assistant. As the fluidity improver, silicic acid, calcium carbonate, titanium oxide, carbon black, kaolin clay, calcined clay, aluminum silicate, magnesium silicate, calcium silicate and the like may be used.
Moreover, when the combination which consists of an epoxy resin and a hardening | curing agent is selected as curable resin (A1) of this invention, in order to accelerate hardening reaction, it is desirable to use a hardening accelerator. There are no particular restrictions on the curing accelerator, but examples include triphenylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, triphenylphosphine / triphenylborane, tetraphenylphosphine / tetraphenyl. Phosphorus compounds such as borate, tertiary amine compounds such as triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo (5,4,0) undecene-7, 2-methylimidazole, 2- Imidazole compounds such as phenylimidazole and 2-phenyl-4-methylimidazole are preferably used.

  The amount of the curing accelerator may be a catalytic amount, but the curing reaction of the phosphorus compound, tertiary amine compound, imidazole compound or the like epoxy resin with a curing agent (for example, phenol resin or acid anhydride). In this case, the curing accelerator may be about 0.1 to 5 parts by mass when the total amount of the epoxy resin and the curing agent is 100 parts by mass.

  When a combination of an epoxy resin and a curing agent is selected as the curable resin (A1) of the present invention, various additives can be blended as necessary. For example, a thermoplastic resin, a thermoplastic elastomer, an organic synthetic rubber, a silicone-based low stress agent, a colorant such as carbon black, an additive such as a halogen trap agent, and a known release agent can be used as appropriate.

[Preparation of low thermal expansion resin composition]
When preparing the low thermal expansion resin composition of this invention with respect to curable resin (A1), it is desirable to pass through two processes. As the first step, a monomer species that forms a uniform dispersion with the ultrafine inorganic filler (B) is selected from one or more monomers constituting the curable resin (A1), and the monomer species is previously dissolved in a solvent. Then, the entire ultrafine inorganic filler (B) contained in the low thermal expansion resin composition is dispersed to prepare a mixed dispersion in which both coexist. Thereafter, the solid material from which the solvent has been removed is pulverized to obtain a fine inorganic filler-containing organic resin matrix.

  Here, the compounding quantity of the ultrafine inorganic filler (B) mixed with curable resin (A1) is 2-30 mass% with respect to the ultrafine inorganic filler containing organic resin matrix, 5-25 If it is the range of the mass%, a favorable result is given in terms of the workability of this process and the performance of the low thermal expansion resin composition.

  As described above, the monomer constituting the curable resin (A1) is not particularly limited as long as the polymerization is started by an external trigger such as heat and light, the molecular weight is increased, and the resin is formed. For example, acrylic resin, methacrylic resin, phenol resin, urea resin, melamine resin, polyurethane resin, epoxy resin and the like can be exemplified. Among these, it can be said that an organic resin matrix composed of an epoxy resin and a curing agent, which have many uses in the semiconductor field, is suitable for the present invention.

  Although it does not receive a restriction | limiting in particular as a solvent used in this process, At least 1 or more types of the monomer which comprises curable resin (A1) is melt | dissolved favorably, In addition, an ultrafine inorganic filler (B) is also included. It must be capable of being well dispersed. Examples of such solvents include hydrocarbons, halogenated hydrocarbons, alcohols, phenols, ethers, acetals, ketones, fatty acids, acid anhydrides, esters, nitrogen compounds, sulfur compounds, cellosolves, etc. A low-melting-point compound having a plurality of functional groups may be mentioned, and it may be appropriately selected in consideration of solubility and workability.

As a subsequent second step, a monomer that forms the curable resin, or a monomer that forms a different type of curable resin from the curable resin (A1), an average particle diameter, in the fine inorganic filler-containing organic resin matrix described above After adding the inorganic filler (C) having a particle diameter of 3 to 50 μm and a curing catalyst, the mixture is melt-mixed, and then melt-mixed with a hot roll, kneader, extruder, etc., then cooled and solidified, and pulverized to an appropriate size. Thus, a molding material can be obtained.
The low thermal expansion resin composition of the present invention is polymerized by a thermosetting reaction in a thermoforming step when finally molding a package of a semiconductor device, and is molded into a predetermined shape.

  In this process, the inorganic filler (C) mixed with the fine inorganic filler-containing organic resin matrix is composed of the total amount of inorganic components combined with the ultrafine inorganic filler (B) described above, and the low thermal expansion resin composition of the present invention. Since it is necessary to mix | blend so that it may become 60-95 mass%, it selects suitably in the range of 30-93 mass%. The content is preferably 40 to 80% by mass, and gives desirable results in terms of moldability and performance of the low thermal expansion resin composition.

  There are no particular restrictions on the distribution ratio of the monomers that form the curable resin (A1) or the curable resin (A1) different in kind from these two steps, but the curable resin is composed of only one type of monomer. If (A1) is formed, the weight ratio may be adjusted as appropriate based on 1: 1. In the case where the curable resin is formed from two or more types of monomers, the entire amount of the curable resin (A1) monomer that can be dissolved in the solvent in the first step is used, and the remaining amount of the monomer is determined in the second step. What is necessary is just to make it mix. The blending ratio of these two types of monomers may be appropriately increased or decreased in consideration of curability based on the equimolar reaction.

  On the other hand, also when preparing the low thermal expansion resin composition of this invention with respect to a thermoplastic resin (A2), it is desirable to pass through two processes. As the first step, the entire amount of the ultrafine inorganic filler (B) and a part of the thermoplastic resin (A2) are mixed in a solvent to prepare a uniform dispersion, and then the solvent is distilled off, followed by drying and grinding. Thus, an organic resin matrix containing ultrafine inorganic particles obtained by uniformly mixing the thermoplastic resin (A2) and the ultrafine inorganic filler is obtained.

  Here, the compounding quantity of the ultrafine inorganic filler (B) mixed with the thermoplastic resin (A2) is 2-30 mass% with respect to the ultrafine inorganic filler-containing organic resin matrix, and 5-25 If it is the range of the mass%, a favorable result is given in terms of the workability of this process and the performance of the low thermal expansion resin composition.

  The thermoplastic resin (A2) is not particularly limited, but the influence of the melt processing temperature on the intended use (for example, the structure and characteristics of the semiconductor element itself and the lead wire in the case of a semiconductor sealing material) is also considered. It is necessary to select the most appropriate one as appropriate. Specific examples include polyester resins, polyamide resins, polycarbonate resins, polycarbonate resins, polyether resins, and the like.

  Although it does not receive a restriction | limiting in particular as a solvent used in this process, It should melt | dissolve a thermoplastic resin (A2) satisfactorily and can also disperse | distribute a super fine inorganic filler (B) favorably. is necessary. Examples of such solvents include hydrocarbons, halogenated hydrocarbons, alcohols, phenols, ethers, acetals, ketones, fatty acids, acid anhydrides, esters, nitrogen compounds, sulfur compounds, cellosolves, etc. A low-melting-point compound having a plurality of functional groups may be mentioned, and it may be appropriately selected in consideration of solubility and workability.

  In the subsequent second step, the above-mentioned fine inorganic filler-containing organic resin matrix is blended with the remaining thermoplastic resin (A2) and all of the inorganic filler (C) at a predetermined composition ratio, and this is blended. After sufficiently uniformly mixing, etc., a melt mixing process using a hot roll, a kneader, an extruder or the like is performed, then cooled and solidified, and pulverized to an appropriate size to obtain a molding material.

  In this process, the inorganic filler (C) mixed with the fine inorganic filler-containing organic resin matrix is composed of the total amount of inorganic components combined with the ultrafine inorganic filler (B) described above, and the low thermal expansion resin composition of the present invention. Since it is necessary to mix | blend so that it may become 60-95 mass%, it selects suitably in the range of 30-93 mass%. The content is preferably 40 to 80% by mass, and gives desirable results in terms of moldability and performance of the low thermal expansion resin composition.

  The low thermal expansion resin composition thus obtained can be suitably molded by transfer molding as long as it is a molding material prepared for the curable resin (A1). On the other hand, if it is the molding material prepared with respect to the thermoplastic resin (A2), it will be suitably shape | molded by injection molding, extrusion molding, etc.

  The low thermal expansion resin composition of the present invention is effective for applications in the semiconductor field such as a semiconductor encapsulating material and an interlayer insulating film, applications in the industrial machine field such as gears, etc. because of its excellent dimensional stability.

Hereinafter, the present invention will be specifically described by way of examples.
Example 1
The thermosetting resin forming the organic resin matrix is YX4000 (Epoxy equivalent eq = 180-192, center value 186, melting point 105 ° C.), which is a biphenyl type epoxy resin as an epoxy resin, a curing agent. As the above, PSM4261 (epoxy equivalent eq = 105, softening point 80 to 84 ° C.) made by Gunei Chemical Co., which is a phenol novolac resin, was weighed.
Among these, the total amount of PSM 4261 weighed in advance for PSM 4261 was dissolved in methyl ethyl ketone at room temperature (20% by mass), and nanosilica dispersion as an ultrafine inorganic filler corresponding to 15% by mass of the total amount of YX4000 and PSM 4261. A uniform liquid was prepared by dropping a predetermined amount of organosilica sol MEK-AC-2140Z (surface modified grade, particle size 10 to 15 nm, dispersion solvent methyl ethyl ketone, silica solid content concentration 30%) manufactured by Kagaku Kogyo Co., Ltd.
Thereafter, in order to remove methyl ethyl ketone, the solvent was distilled off by a rotary evaporator (40 ° C.), followed by vacuum drying (40 ° C., 24 hours). The collected mixture of PSM4261 and nanosilica can be easily pulverized. After pulverization in a mortar, the mixture was used as a PSM4261 / silica mixed powder.
Next, the entire weighed amount of YX4000 and PSM4261 / nanosilica mixed powder was put into a kneader preheated to 120 ° C. and kneaded. Furthermore, Nippon Steel & Sumikin Materials Co., Ltd., an inorganic filler (micron silica) with an average particle size of 0.3 to 50 μm, whose blending amount was adjusted so that the total amount of silica component was 60% by mass relative to the organic resin matrix component “HS203” (spherical silica, top cut grade, d50 particle size 10.5 μm) manufactured by Micron Company was added, and these were heated and kneaded at 120 ° C. using a biaxial roll, and finally triphenylphosphine ( 1 wt% of TPP) was mixed, and the mixture was immediately recovered, cooled, and pulverized using a small pulverizer (Wonder Blender-WB-1), and the low thermal expansion resin composition of the present invention (uncured powder) ) Was prepared.
Furthermore, a predetermined amount of the low thermal expansion resin composition (uncured powder) was placed in a stainless steel mold having a thickness of 500 μm and a 50 mm × 50 mm cavity, and hot press molded. For molding, using a vacuum press machine (high precision hot press machine SA-401A with a vacuum chamber manufactured by Tester Sangyo), curing is performed under reduced pressure at 175 ° C. for 1 hour under 5 MPa pressure, and then transferred to an oven at 175 ° C. Curing was continued for 5 hours to obtain a sheet molded body of the low thermal expansion resin composition.

(Example 2)
In the same manner as in Example 1, a mixed powder of YX4000 and PSM4261 / nanosilica (corresponding to 15 parts by mass) was prepared, put into a kneader and kneaded. On the other hand, a predetermined amount of inorganic filler (micron silica) HS203 is added to 1% by weight aqueous solution of KBM-903 (3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Silicone Co., Ltd. The amino-treated inorganic filler, which was recovered from the organic resin matrix component, was adjusted so that the total amount of the silica component was 80% by mass with respect to the organic resin matrix component, After kneading with a shaft roll, TPP was added and recovered and pulverized to prepare a low thermal expansion resin composition (uncured powder) of the present invention. Subsequent molding and curing steps were performed in the same manner as in Example 1 to obtain a sheet molded body of the low thermal expansion resin composition.

(Example 3)
In the same manner as in Example 1, a mixed powder of YX4000 and PSM4261 / nanosilica (corresponding to 15 parts by mass) was prepared, put into a kneader and kneaded. Then, the amino-treated inorganic filler prepared according to Example 2 was adjusted so that the amount of silica component was 80% by mass with respect to the organic resin matrix component, and after kneading with a biaxial roll, After adding TPP, it was recovered and ground to prepare a low thermal expansion resin composition (uncured powder) of the present invention. Subsequent molding and curing steps were performed in the same manner as in Example 1 to obtain a sheet molded body of the low thermal expansion resin composition.

Example 4
The YX4000 and PSM4261 / nanosilica mixed powder was prepared in the same manner as in Example 1 except that the amount of ultrafine inorganic filler (nanosilica) dispersed in the methyl ethyl ketone solution of PSM4261 in advance was changed to 20% by mass of the total amount of YX4000 and PSM4261. Prepared, put into a kneader and kneaded.
Next, after adding inorganic filler (micron silica) HS203, the blending amount of which was adjusted so that the total amount of silica component was 60% by mass with respect to the organic resin matrix component, kneading with a biaxial roll, and then adding TPP The recovered and pulverized product was prepared to prepare a low thermal expansion resin composition (uncured powder) of the present invention. Subsequent molding and curing steps were performed in the same manner as in Example 1 to obtain a sheet molded body of the low thermal expansion resin composition.

(Example 5)
In the same manner as in Example 3, a mixed powder of YX4000 and PSM4261 / nanosilica (corresponding to 20 parts by mass) was prepared, put into a kneader and kneaded. Then, inorganic filler (micron silica) HS203, which was adjusted in the blending amount so that the total amount of silica component is 80% by mass with respect to the organic resin matrix component, was added, kneaded with a biaxial roll, and recovered after adding TPP. The mixture was pulverized to prepare a low thermal expansion resin composition (uncured powder) of the present invention. Subsequent molding and curing steps were performed in the same manner as in Example 1 to obtain a sheet molded body of the low thermal expansion resin composition.

(Example 6)
Sumitex LG21 manufactured by Sumitomo Chemical Co., Ltd. was used as the methacrylic resin for the thermoplastic resin serving as the organic resin matrix.
A predetermined amount of MEK-AC-2140Z containing 50 parts by mass of Sumipex LG21 in methyl ethyl ketone (20 wt%) and further containing an ultrafine inorganic filler (nanosilica) corresponding to 10% by mass with respect to 100 parts of Sumipex LG21 Was dropped to prepare a uniform solution.
Thereafter, in order to remove methyl ethyl ketone, the solvent was distilled off by a rotary evaporator (40 ° C.), followed by vacuum drying (40 ° C., 24 hours). The collected mixture of Sumipex LG21 and nanosilica was pulverized in a mortar and then used as a Sumipex LG21 / nanosilica mixed powder.
Next, to the remaining 50 parts by mass of Sumipex LG21 that has already been weighed, an inorganic filler (micron silica) HS203 whose blending amount is adjusted so that the total amount of silica components is 60% by mass with respect to 100 parts by mass of methacrylic resin, After heat-kneading at 260 ° C. using a twin-screw kneader (Toyo Seiki Seisakusho Lab Plast Mill), add the entire amount of the Sumipex LG21 / Nanosilica mixed powder and knead and immediately collect, cool, and pulverize the mixture. A low thermal expansion resin composition of the present invention was prepared by pulverization using a machine (Wonder Blender-WB-1).
Furthermore, a predetermined amount of the low thermal expansion resin composition was placed in a stainless steel mold having a thickness of 500 μm and a cavity of 50 mm × 50 mm, and hot press molded. For molding, using a vacuum press machine (high precision hot press machine SA-401A with a vacuum chamber manufactured by Tester Sangyo), pressurizing at 260 ° C. for 30 minutes under reduced pressure, taking out from the mold after cooling, and having a low thermal expansion resin composition A sheet molded product of the product was obtained.

(Comparative Example 1)
The epoxy resin YX4000 used in Example 1 and the phenol novolac resin PSM4261 which is a curing agent are weighed in an equivalent amount, 1% by mass of the curing catalyst TPP is mixed, put in a glass beaker and heated to 120 ° C., and all organic components are After melting, the mixture was stirred with a glass rod and then gradually cooled. The cured resin returned to room temperature was taken out and pulverized using a small pulverizer (Wonder Blender-WB-1) to prepare a cured resin (uncured powder).
Furthermore, a predetermined amount of the cured resin (uncured powder) was placed in a stainless steel mold having a thickness of 500 μm and a 50 mm × 50 mm cavity, and hot press molded. For molding, using a vacuum press machine (high precision hot press machine SA-401A with a vacuum chamber manufactured by Tester Sangyo), curing is performed under reduced pressure at 175 ° C. for 1 hour under 5 MPa pressure, and then transferred to an oven at 175 ° C. Curing was continued for 5 hours to obtain a cured resin sheet molded body.

(Comparative Example 2)
The YX4000 and PSM4261 / nanosilica mixed powder was prepared in the same manner as in Example 1 except that the amount of the ultrafine inorganic filler (nanosilica) dispersed in the methyl ethyl ketone solution of PSM4261 in advance was changed to 60% by mass of the total amount of YX4000 and PSM4261. It was prepared and put into a kneader to try kneading. However, the kneader stopped in the process of sequentially feeding the mixed powder into the kneader, and it was not possible to process all the mixed powder.
Since the low thermal expansion resin composition (uncured powder) of the present invention was not obtained, the study of Comparative Example 2 was interrupted.

(Comparative Example 3)
A mixed powder of YX4000 and PSM4261 / nanosilica in the same manner as in Example 1 except that the amount of the ultrafine inorganic filler (nanosilica) dispersed in the methyl ethyl ketone solution of PSM4261 in advance was changed to 1.5% by mass of the total amount of YX4000 and PSM4261. The body was prepared, put into a kneader and kneaded.
Next, after adding inorganic filler (micron silica) HS203, the blending amount of which was adjusted so that the total amount of silica component was 60% by mass with respect to the organic resin matrix component, kneading with a biaxial roll, and then adding TPP The recovered and pulverized product was prepared to prepare a low thermal expansion resin composition (uncured powder) of the present invention. Subsequent molding and curing steps were performed in the same manner as in Example 1 to obtain a sheet-molded body of the thermally expandable resin composition.

(Comparative Example 4)
A predetermined amount of Sumipex LG21 pellets was placed in a stainless steel mold having a thickness of 500 μm and a 50 mm × 50 mm cavity, and hot press molded. For molding, using a vacuum press machine (high precision hot press machine SA-401A with a vacuum chamber manufactured by Tester Sangyo), pressurizing at 260 ° C. for 30 minutes under reduced pressure, taking out from the mold after cooling, a sheet of thermoplastic resin A molded body was obtained.

(Comparative Example 5)
50 parts by mass of Sumipex LG21 was previously dissolved in methyl ethyl ketone (20 wt%), and MEK-AC-2140Z containing an ultrafine inorganic filler (nanosilica) corresponding to 1.5% by mass with respect to 100 parts of Sumipex LG21. A predetermined amount was dropped to prepare a uniform solution.
Thereafter, in order to remove methyl ethyl ketone, the solvent was distilled off by a rotary evaporator (40 ° C.), followed by vacuum drying (40 ° C., 24 hours). The collected mixture of Sumipex LG21 and nanosilica was pulverized in a mortar and then used as a Sumipex LG21 / nanosilica mixed powder.
Next, to the remaining 50 parts by mass of Sumipex LG21 that has already been weighed, an inorganic filler (micron silica) HS203 whose blending amount is adjusted so that the total amount of silica components is 60% by mass with respect to 100 parts by mass of methacrylic resin, After heat-kneading at 260 ° C. using a twin-screw kneader (Toyo Seiki Seisakusho Lab Plast Mill), add the entire amount of the Sumipex LG21 / Nanosilica mixed powder and knead and immediately collect, cool, and pulverize the mixture. The thermoplastic resin composition of the present invention was prepared by pulverization using a machine (Wonder Blender-WB-1).
Further, a predetermined amount of the thermoplastic resin composition was placed in a stainless steel mold having a thickness of 500 μm and a 50 mm × 50 mm cavity, and hot press molded. For molding, using a vacuum press machine (high precision hot press machine SA-401A with a vacuum chamber manufactured by Tester Sangyo), pressurizing at 260 ° C. for 30 minutes under reduced pressure, taking out from the mold after cooling, a thermoplastic resin composition A sheet compact was obtained.

  Tables 1 and 2 collectively show the results of evaluation of the blending compositions in Examples 1 to 6 and Comparative Examples 1 to 5 and the physical properties of the resin compositions. In Tables 1 and 2, the magnitude of the interaction between the inorganic fine particles and the organic resin is distinguished in three stages, ◯, Δ, and X. Within the scope of the present invention, the combination with the largest interaction is indicated by ◯, the combination at which no interaction can be expected is indicated by ×, and the middle thereof is indicated by △. The properties of the molded sheets of the resins and resin compositions obtained in the above Examples and Comparative Examples were evaluated by the methods shown below.

1. Linear expansion coefficient Test pieces cut into a width of 5 mm and a length of 14 mm, respectively, from the sheet molded body were subjected to a linear expansion coefficient under the condition of a heating rate of 5.0 ° C./min using a TMA apparatus (Thermo Plus Thermo Plus 8310 type). It was measured. The results are shown in Table 1.

2. Formability In a hot press for producing a sheet compact, the occupied state of the molded product in the cavity under the press conditions (curing system is 175 ° C. for 1 hour, thermoplastic system is 260 ° C. for 30 minutes) is visually observed, and the following determination is made. Evaluated by criteria.
○: The cavity is sufficiently filled with the resin or the resin composition.
Δ: A part of the cavity is not filled with the resin or the resin composition.
X: The fluidity | liquidity of resin or a resin composition is scarce, it is not filled, or fluidity | liquidity is not seen in resin or a resin composition.
-: "-" In Comparative Example 2 means that the resin composition was not made.

As can be seen from Table 1, all of Examples 1 to 5 having a curable resin as an organic resin matrix had a low coefficient of linear expansion. In particular, when the raw materials subjected to surface treatment for both nano silica and micro silica were used, the linear expansion coefficient was significantly reduced. On the other hand, when the amount of nanosilica added increased, the moldability tended to be slightly inferior, but it was judged that any of the prepared cases had sufficient moldability. Similar behavior was confirmed in the thermoplastic resin composition.
On the other hand, in the case where no nanosilica is blended (Comparative Example 1) or the blending amount is small (Comparative Example 3), the reduction of the linear expansion coefficient is insufficient. Moreover, when there was too much nano silica, the desired cured resin composition was not able to be prepared.
A similar behavior was confirmed in the thermoplastic resin composition, and it was considered to be a universal behavior regardless of the properties of the organic resin matrix.

While the organic-inorganic composite material of the present invention can greatly reduce the linear expansion coefficient of thermosetting resins and thermoplastic resins, it has sufficient moldability and is suitable as an organic resin sealing material for semiconductor devices and the like. Can be used.

Claims (4)

A resin composition comprising an inorganic filler and an organic resin,
In the organic resin matrix (A) made of the curable resin (A1) or the thermoplastic resin (A2), the ultrafine inorganic filler (B) having an average primary particle size of 1 to 50 nm is uniform at the primary particle size level. An organic resin composition in which an inorganic filler (C) having an average particle size of 0.3 to 50 μm is dispersed, and the blending amount of the ultrafine inorganic filler (B) is a resin. It is 2-30 mass% with respect to a matrix (A), and the sum total of the inorganic component combined with the ultrafine inorganic filler (B) and the inorganic filler (C) is 60-95 mass% of the said resin composition. A low thermal expansion resin composition characterized by being.   The primary particles of the ultrafine inorganic filler (B) and / or the inorganic filler (C) are molecules of the curable resin (A1) or the thermoplastic resin (A2) forming the organic resin matrix (A). Through one or more of the following: chemical structure and electrostatic interaction, van der Waals interaction, hydrogen bonding interaction, π / π stacking interaction, coordination bond force, charge transfer interaction and hydrophobic effect The low thermal expansion resin composition according to claim 1, further comprising a surface treatment portion capable of generating attraction.   The fine inorganic filler (B) having an average primary particle diameter of 1 to 50 nm is mixed in a solution in which a monomer that forms the curable resin (A1) is dissolved in a solvent, and the solvent is uniformly dispersed. A fine inorganic filler-containing organic resin matrix formed by pulverizing the solid material from which the solid has been removed to form a powder, and forming the curable resin (A1) on the fine inorganic filler-containing organic resin matrix or the curable resin A monomer that forms a different type of curable resin from the resin (A1), an inorganic filler (C) having an average particle diameter of 3 to 50 μm, and a curing catalyst are added, melt-mixed, and then molded. A method for producing a low thermal expansion resin composition. The solution obtained by dissolving the thermoplastic resin (A2) in a solvent is mixed with the fine inorganic filler (B) having an average primary particle diameter of 1 to 50 nm, uniformly dispersed, and then the solid from which the solvent is removed A fine inorganic filler-containing organic resin matrix that is pulverized to form a powder, and the inorganic inorganic filler (C) having an average particle size of 0.3 to 50 μm in the fine inorganic filler-containing organic resin matrix; A method for producing a low thermal expansion resin composition, wherein the additional thermoplastic resin (A2) is added, mixed in a molten state, and then molded.