JPH0977958A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition which has high flame retardancy, good moldability and high resistance to soldering heat and gives a semiconductor device with high reliability. SOLUTION: This resin composition contains an epoxy resin, a curing agent and an inorganic filler, wherein the inorganic filler accounts for 70-97wt.% of the composition and contains 0.1-20wt.% alumina.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition excellent in flame retardancy, solder heat resistance and high temperature reliability, preferably an epoxy resin composition for semiconductor encapsulation and a semiconductor device.

[0002]

2. Description of the Related Art As a method of sealing an electronic circuit portion such as a semiconductor device, a sealing resin composed of an epoxy resin, a curing agent, and an inorganic filler is used in view of the balance between economy, productivity and physical properties. The main focus is on the sealing method. With the recent trend toward thinner and higher-density semiconductor devices, requirements for semiconductor devices such as solder heat resistance and high-temperature reliability have been increasing, and accordingly, requirements for sealing resins have also increased.

[0003] In order to ensure safety, electronic components such as semiconductors are required to have flame retardancy according to UL standards. Therefore, a halogenated polymer such as a brominated epoxy resin as a flame retardant and an antimony compound such as antimony trioxide as a flame retardant have been added to the sealing resin.

[0004]

In recent years, there has been an increasing awareness of environmental issues, and there has been an increasing interest in various compounds used as flame retardants in resins for semiconductor encapsulation.

For example, it has been pointed out that a halogenated polymer flame retardant generates a halogenated gas during combustion. Further, under a high temperature environment, halogenated gas generated from the flame retardant is considered to be a factor that corrodes the wiring of the semiconductor with time and reduces the reliability of the semiconductor device.

When an antimony compound is contained,
There is a concern about the problem of waste treatment of used sealing resin.

Therefore, it is desired that these halogenated polymers and antimony oxide be added to the minimum necessary amount.

As flame retardants other than the above halogenated polymers and antimony oxide, there are hydroxides such as aluminum hydroxide and phosphoric acid ester as shown in JP-A-62-240314, and phosphorus flame retardants. To do. However, when these flame retardants are used in the encapsulating resin, the effect of imparting flame retardancy cannot be obtained unless a large amount is added to the encapsulating resin, resulting in deterioration of the resin properties or decomposition of the flame retardant during molding. Due to foaming, the appearance of the obtained molded product was deteriorated. Due to these various problems, hydroxides and phosphorus-based flame retardants have been used only for special fields as encapsulating resins.

The present invention is characterized in that flame retardancy is imparted by using a specific amount of alumina as a part of the inorganic filler. References compounded in the resin composition include JP-A-63-70446 and JP-A-63-183915, but the purpose of compounding these aluminas is to dissipate heat generated from the semiconductor element. There is no description about flame retardancy.

The present invention addresses the above problems by flame retardance,
An object of the present invention is to provide an epoxy resin composition which is excellent in high-temperature reliability and does not necessarily require a conventional flame retardant, particularly an epoxy resin composition for semiconductor encapsulation.

[0011]

That is, the present invention provides a resin composition containing an epoxy resin (A), a curing agent (B) and an inorganic filler (C), which comprises the inorganic filler (C). The resin composition contains 70 to 97% by weight, and the inorganic filler (C) further contains 0.1 to 50% by weight of alumina.
It is an epoxy resin composition containing, more preferably 70 to 97% by weight of the inorganic filler (C) in the resin composition.
And the inorganic filler (C) contains 0.1 to 0.1% of alumina.
Composition containing 20% by weight or inorganic filler (C)
Is 87 to 97% by weight in the resin composition, and the inorganic filler (C) further contains 0.1 to 50% by weight of alumina.

Furthermore, the present invention is a semiconductor device in which a semiconductor element is sealed with the above epoxy resin composition, and the epoxy resin composition having the above composition is melt-mixed. It is a method of manufacturing a product.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.
In the present invention, weight means mass.

The epoxy resin (A) in the present invention is not particularly limited as long as it has a plurality of epoxy groups in the molecule, and specific examples thereof include biphenyl type epoxy resin, cresol novolac type epoxy resin and phenol novolac. Type epoxy resin, bisphenol A
Type epoxy resins, various novolak type epoxy resins synthesized from bisphenol A, resorcin, and the like, linear aliphatic epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins.

Among these epoxy resins (A), those particularly preferably used in the present invention have a skeleton represented by the following general formula (I) in view of excellent solder heat resistance and moldability. It has the biphenyl type epoxy resin (a) which it has as an essential component.

Embedded image (However, R1 to R8 in the formula are a hydrogen atom, a carbon number 1 to
4 represents an alkyl group or a halogen atom. The epoxy resin (A) is 50% by weight of a biphenyl type epoxy resin having a skeleton represented by the general formula (I).
The above content, particularly 70% by weight or more, is preferable.

A preferred specific example of the epoxy resin skeleton represented by the above formula (I) is 4,4'-bis (2,3-).
Epoxypropoxy) biphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'
Tetramethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetramethyl-2-chlorobiphenyl, 4,4'-bis (2,3-
Epoxypropoxy) -3,3 ', 5,5'-tetramethyl-2-bromobiphenyl, 4,4'-bis (2,3
-Epoxypropoxy) -3,3 ', 5,5'-tetraethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3', 5,5'-tetrabutylbiphenyl, 4,4 '-Bis (2,3-epoxypropoxy) biphenyl and 4,4'-bis (2,3-epoxypropoxy) -3,3', 5,5'-tetramethylbiphenyl, etc. , Or even when used in a mixed system.

The epoxy resin (A) may contain two or more kinds of epoxy resins in combination.

In the present invention, the blending amount of the epoxy resin (A) is usually 0.05 to 25% by weight, preferably 2 to 15% by weight, and more preferably 2 to 15% by weight in the epoxy resin composition from the viewpoint of moldability and adhesiveness. It is 1 to 10% by weight, more preferably 2 to 10% by weight, and further 2 to 8% by weight.

The curing agent (B) in the present invention is not particularly limited as long as it reacts with the epoxy resin (A) and cures. Usually a compound having a phenolic hydroxyl group,
Compounds having acid anhydrides and amines are used. Of these, specific examples of the phenol-based curing agent, that is, the compound having two or more phenolic hydroxyl groups in the molecule, include, for example, phenol novolac resin, cresol novolac resin, phenol aralkyl resin, bisphenol A, and resorcin. Examples include various novolac resins, tris (hydroxyphenyl) methane, dihydrobiphenyl, polyphenol compounds such as phenol p-xylylene copolymer represented by the following formula (II), and polyvinylphenol.

Examples of the compound having an acid anhydride include maleic anhydride, phthalic anhydride and pyromellitic dianhydride. Examples of the amines include aromatic amines such as metaphenylenediamine, di (aminophenyl) methane (commonly called diaminodiphenylmethane), and diaminodiphenylsulfone. For semiconductor encapsulation, a phenol-based curing agent is preferably used from the viewpoint of heat resistance, moisture resistance and storage stability, and two or more curing agents may be used in combination depending on the application.

In the present invention, the content of the curing agent (B) is usually 1 to 20% by weight, preferably 1 to 10% by weight,
Preferably it is 1 to 5% by weight. Furthermore, the compounding ratio of the epoxy resin (A) and the curing agent (B) is such that the chemical equivalent ratio of (B) to (A) is 0.5 to 1.5 from the viewpoint of mechanical properties and moisture resistance reliability. In particular, it is preferably in the range of 0.8 to 1.2.

In the present invention, a curing catalyst may be used to accelerate the curing reaction between the epoxy resin (A) and the curing agent (B). The curing catalyst is not particularly limited as long as it promotes the curing reaction. For example, 2-methylimidazole,
Imidazole compounds such as 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyl Tertiary amine compounds such as dimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0) undecene-7, zirconium tetra Organometallic compounds such as methoxide, zirconium tetrapropoxide, tetrakis (acetylaceto) zirconium, tri (acetylaceto) aluminum and triphenylphosphine, trimethylphosphine, triethylphosphine, trib Le phosphine, tri (p- methylphenyl) phosphine, an organic phosphine compound such as tri (nonylphenyl) phosphine and the like. Among them, an organic phosphine compound is preferably used from the viewpoint of moisture resistance. Two or more of these curing catalysts may be used in combination depending on the application, and the addition amount thereof is preferably in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the epoxy resin (A).

In the present invention, the inorganic filler (C) is contained in the resin composition in an amount of 70 to 97% by weight, and the inorganic filler (C) is further characterized in that it contains alumina in an amount of 0.1 to 50% by weight. However, from the viewpoint of good flame retardancy and moldability, as the first composition, the inorganic filler (C) is used.
Is 70 to 97% by weight in the resin composition, and the inorganic filler (C) contains 0.1 to 20% by weight of alumina, and the inorganic filler (C) is the resin composition as the second composition. The composition is preferably 87 to 97% by weight, and the inorganic filler (C) further contains 0.1 to 50% by weight of alumina.

The alumina referred to herein is aluminum oxide.

From the viewpoint of flame retardancy and moldability, the amount of alumina in the inorganic filler (C) may be the amount shown above, but from the viewpoints of moldability and flame retardancy, it is preferable. , 1 to 20% by weight, further 1 to 18% by weight, still further 1 to 10% by weight, still more preferably 1 to 9% by weight.

The inorganic filler (C) preferably contains silica, that is, silicon dioxide, as the inorganic filler other than alumina. The content of silica in the inorganic filler (C) is 50 to 99.9% by weight, 5
2.9-99% by weight, further 80-99% by weight, further 9
A blending amount of 0 to 99% by weight is preferable.

As such an inorganic filler, those in which alumina and silica coexist in the particles, and particles containing 50% by weight or more of alumina and 50% by weight of silica are used.
A particle mixture in which the particles contained above are used in combination can be used.
Of these, the latter particle mixture form is preferably used from the viewpoint of effects on various properties, and it is more preferable to substantially mix alumina particles containing alumina as a main component and silica particles containing silica as a main component.

As the particles containing alumina as a main component,
Depending on its crystal structure, there are α, γ, δ, θ types, etc., and any one can be used, and a plurality of these may be used in combination, but the thermal / chemical stability and the thermal conductivity of the resin composition can be used. From the viewpoint of properties, α-alumina is preferably used. α-
Any method can be used as the method for producing alumina.
For example, buyer method, detonation of aluminum powder (VM
C: Vaporrized Metal Combustion) method and the like.

Examples of the silica particles include amorphous silica and crystalline silica. Amorphous silica particles are preferably used because they have a large effect of lowering the linear expansion coefficient and are effective in reducing stress. The amorphous silica particles can be produced by any production method. Examples thereof include a method of melting crystalline silica and a method of synthesizing from various raw materials.

The shape and particle size of the inorganic filler and the alumina particles and silica particles to be mixed with the inorganic filler in the present invention are not particularly limited, but spherical particles each having a particle size of 3 μm or more and 40 μm or less are contained in the inorganic filler. The content of 60% by weight or more, more preferably 90% by weight or more is preferable from the viewpoint of fluidity during molding.

The average particle size as used herein means a particle size (median size) at which the cumulative weight becomes 50%.

In the present invention, the proportion of (C) in the inorganic filler is as shown above, but from the viewpoint of flame retardancy, moldability and low stress, it is preferably 80 to 97% by weight, more preferably 85-97% by weight, 87-97% by weight, 8
7 to 95% by weight.

In the present invention, the inorganic filler is surface-treated in advance with a coupling agent such as a silane coupling agent, a titanate coupling agent, an aluminate coupling agent or the like to seal the semiconductor element with the epoxy resin composition. It is preferable in that the reliability of the semiconductor device is improved.

As the silane coupling agent, those in which a hydrolyzable group such as an alkoxy group, a halogen atom and an amino group and an organic group are directly bonded to a silicon atom, and a partial hydrolyzed condensate thereof are generally used. As the hydrolyzable group, an alkoxy group, in particular, a methoxy group and an ethoxy group are preferably used. As the organic group, a hydrocarbon group or a hydrocarbon group substituted with a nitrogen atom, an oxygen atom, a halogen atom, a sulfur atom or the like is used, and a hydrocarbon group substituted with the above atom is preferably used. As the substituted hydrocarbon group, those having an epoxy group and those having an amino group are preferably used. Among them, those having a secondary amino group, and those having a secondary amino group in all amino groups are preferably used. Examples of the silane coupling agent include the following.

As a silane coupling agent having an organic group to which an epoxy group is bonded, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysisilane, γ- (2,3-epoxycyclohexyl) propyltrisilane Methoxysilane.

As those having an amino group, N-β-
(Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl)-
γ-aminopropyltriethylsilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-
(N, N-dimethylamino) propyltrimethoxysilane, γ- (N-phenylamino) propyltrimethoxysilane, γ- (N-phenylamino) propylmethyldimethoxysilane, γ- (N-methylamino) propyltrimethoxy Silane, γ- (N-methylaminopropyl)
Methyldimethoxysilane, γ- (N-ethylamino) propyltrimethoxysilane, and γ- (N-ethylamino) propylmethyldimethoxysilane.

Others include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane.

In the present invention, a bromine compound can be blended although it is not an essential component. The bromo compound is usually added to the epoxy resin composition for semiconductor encapsulation for the purpose of flame retardance, and is not particularly limited.

Preferred specific examples of the bromine compound present are brominated bisphenol A type epoxy resins, brominated epoxy resins such as brominated phenol novolac type epoxy resins, brominated polycarbonate resins, brominated polystyrene resins, brominated polyphenylene oxide. Examples thereof include resins, tetrabromobisphenol A, decabromodiphenyl ether and the like. Among them, brominated epoxy resins such as brominated bisphenol A type epoxy resin and brominated phenol novolac type epoxy resin are particularly preferable from the viewpoint of moldability.

The amount of the bromine compound present in the composition of the present invention is preferably 0.3% by weight or less in view of flame retardancy and high temperature reliability. Particularly preferably, it is 0.1% by weight or less, more preferably 0.05% by weight or less, and further, it is not substantially blended. Focusing on the bromine atom,
It is preferably 2% by weight or less, 0.07% by weight or less, and more preferably 0.04% by weight or less.

Although not an essential component in the present invention, an antimony compound can be added. Usually added to the epoxy resin composition for semiconductor encapsulation as a flame retardant aid,
It is not particularly limited, and may be a known one. Preferred specific examples of the antimony compound include antimony trioxide,
Examples include antimony tetroxide and antimony pentoxide.

The amount of the antimony compound present in the composition of the present invention is preferably 0.3% by weight or less based on the whole amount in view of flame retardancy and high temperature reliability. Particularly preferably, it is 0.1% by weight or less, more preferably 0.05% by weight or less, and further, it is not substantially blended. Focusing on antimony atoms, it is preferable that the order is 0.25% by weight or less, 0.075% by weight or less, and more preferably 0.0375% by weight or less.

In the epoxy resin composition of the present invention,
It is preferable that the oxygen index after curing of the epoxy resin is 42% or more.

Here, the oxygen index is a value calculated according to the following equation from the value obtained by obtaining the volume concentration of each gas at the combustion limit point according to JIS K7201. Oxygen index (%) = [oxygen] / ([oxygen] + [nitrogen]) × 100

Further, in the epoxy resin composition of the present invention, it is preferable that the flame retardancy after curing of the epoxy resin is V-0 in UL standard from the viewpoint of solder heat resistance, and further, it has been described above. The content of bromine atom or the content of antimony atom is preferably V-0.

The epoxy resin composition of the present invention includes carbon black, coloring agents such as iron oxide, ion trapping materials such as hydrotalcite, olefin copolymers, modified nitrile rubbers, modified polybutadiene rubbers and other elastomers, Thermoplastic resins such as polyethylene, long-chain fatty acids, metal salts of long-chain fatty acids, esters of long-chain fatty acids, amides of long-chain fatty acids, mold release agents such as paraffin wax, various silicon compounds, and crosslinking of organic peroxides, etc. The agent can be optionally added.

The epoxy resin composition of the present invention is preferably produced by melt-mixing, and usually 50 by using a known kneading method such as Banbury mixer, kneader, roll, single-screw or twin-screw extruder and cokneader. ~
It is manufactured by melt-kneading at a temperature of 170 ° C, preferably 70 to 150 ° C.

The epoxy resin composition of the present invention is usually used in the form of powder or tablet for encapsulating a semiconductor device. Using a low-pressure transfer molding machine, the epoxy resin composition is applied to the member with the semiconductor element fixed to the substrate,
For example, 120 to 250 ° C, preferably 150 to 200 ° C
By molding at the above temperature to obtain a cured product of the epoxy resin composition, a semiconductor device sealed with the cured product of the epoxy resin composition is manufactured. If necessary, an additional heat treatment (for example, 150 to 200 ° C., 2 to 15 hours) can be performed.

Here, the semiconductor device refers to an electronic circuit (integrated circuit) made by integrating and wiring transistors, diodes, resistors, capacitors, etc. on a semiconductor chip or a substrate, and widely, the epoxy of the present invention. Refers to an electronic component sealed with a resin composition.

[0050]

The present invention will be described below in detail with reference to examples. In addition,% in an Example shows weight%.

The raw materials used in the present invention and the compounding amounts in the composition are as follows. <Epoxy resin I> Orthocresol novolak resin having an epoxy equivalent of 200 (the amount is shown in Table 1) <Epoxy resin II>4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5 '-Tetramethylbiphenyl (compounding amount is described in Table 1) <Curing agent I> Phenol novolak resin having a hydroxyl equivalent of 107 (compounding amount is described in Table 1) <Curing agent II> Phenol compound shown below (compounding amount (See Table 1)

Embedded image (However, containing about 90% by weight of a component in which n is 1 to 3) <Inorganic filler I> Spherical α-alumina having an average particle size of 16 μm (AS-30, manufactured by Showa Denko KK) (compounding amount is shown in Table 1) <Inorganic filler II> Amorphous fused silica having an average particle size of 15 μm (blending amount is shown in Table 1) <Flame retardant> Epoxy equivalent 400, bromine content 50% by weight
Brominated bisphenol A type resin (blending amount shown in Table 1) <Flame retardant aid> Antimony trioxide (blending amount shown in Table 1) <Curing accelerator> Triphenylphosphine (0.1% by weight) < Silane coupling agent> N-phenylaminopropyltrimethoxysilane (1.0 wt%) (Silane coupling agent was previously mixed with the inorganic filler.) <Colorant> Carbon black (0.2 wt% ) <Release Agent> Carbana wax (0.3% by weight) Example Comparative Example Each component was dry blended by a mixer in the composition ratio shown in Table 1. This was heated and kneaded for 5 minutes using a mixing roll having a roll surface temperature of 90 ° C., and then cooled and pulverized to produce an epoxy resin composition for semiconductor encapsulation.

[0052]

[Table 1]

This resin composition was molded by a low-pressure transfer molding method under the conditions of 175 ° C. and a curing time of 2 minutes, post-cured under the condition of 180 ° C. for 5 hours, and each resin composition was measured by the following physical property measuring methods. The physical properties of the product were evaluated. Unless otherwise specified, molding conditions were 175 ° C. and a cure time of 2 minutes, and post cure was 180 ° C. and 5 hours. Solder heat resistance: A simulated element with Al deposited on the surface
20 pieces of 160 pin QFP (quad flat package) with a chip size of 12 × 12 mm were formed, and 85 ° C. /
IR of maximum temperature 245 ° C after humidified at 85% RT for 72 hours
After heat treatment in a reflow furnace, the number of external cracks was checked. Water absorption: The water absorption of the resin composition was measured after 160 pin QFP used for the solder heat resistance test was humidified at 85 ° C./85% RH for 100 hours. High-temperature reliability: A 16-pin DIP (dual in-line package) equipped with a simulated element was used to evaluate high-temperature reliability at 200 ° C., and a time at which the cumulative failure rate reached 63% was determined as a high-temperature characteristic life. Flame retardancy test: A 5 ″ × 1/2 ″ × 1/16 ″ combustion test specimen was molded and post-cured, and evaluated for flame retardancy according to UL94 standard. Oxygen index: 5 ″ × 1/2 ″ × Form 1/8 "test piece
After post-curing, the volume concentration of each gas at the combustion limit point was determined according to JIS K7201. Oxygen index (%) = [oxygen] / ([oxygen] + [nitrogen]) PKG filling property: 160 pin QF used for solder heat resistance test
After molding, P was visually observed and observed with a microscope to check for unfilled voids.

Table 2 shows the evaluation results. As can be seen from the table, the epoxy resin composition of the present invention is excellent in flame retardancy, solder heat resistance, high temperature reliability and PKG filling property.

[0055]

[Table 2]

On the other hand, when the amount of the inorganic filler (C) added is less than 70%, or when the amount of the inorganic filler (C) added is 70% or more and no alumina is contained, flame retardancy is obtained. The sex is inferior.

If the amount of alumina in the inorganic filler (C) is too large, the flame retardancy and filling properties are poor.

When a flame retardant and a flame retardant aid are contained but no alumina is contained, the flame retardancy is excellent, but the high temperature reliability tends to be poor.

[0059]

According to the present invention, by adding a specific amount of alumina to a specific amount of the inorganic filler, flame retardancy is improved, good moldability, high solder heat resistance, and high reliability in the obtained semiconductor device are obtained. Gender.

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Claims (16)

[Claims] 1. A resin composition containing an epoxy resin (A), a curing agent (B), and an inorganic filler (C) containing alumina as an essential component, wherein the inorganic filler (C) is a resin composition. An epoxy resin composition containing 70 to 97 wt% of alumina and 0.1 to 20 wt% of alumina with respect to the inorganic filler (C). 2. The epoxy resin composition according to claim 1, wherein the content of the inorganic filler (C) is 82 to 97% by weight of the whole composition. 3. The epoxy resin composition according to claim 1, wherein the inorganic filler (C) contains silica as an essential component. 4. The method according to claim 1, wherein the content of the silica is inorganic filler (C).
The epoxy resin composition according to claim 3, wherein the content is 80 to 99.9% by weight. 5. The epoxy resin composition according to claim 1, wherein the epoxy resin (A) contains a biphenyl type epoxy resin (a) having a structure of the following formula (I) as an essential component. Embedded image (However, R1 to R8 in the formula are a hydrogen atom, a carbon number 1 to
4 represents an alkyl group or a halogen atom). 6. The epoxy resin composition according to claim 1, wherein the flame retardancy of the epoxy resin composition after the epoxy resin is cured is V-0 in UL94 standard. 7. A resin composition containing an epoxy resin (A), a curing agent (B), and an inorganic filler (C) containing alumina as an essential component, the inorganic filler (C) being a resin composition. An epoxy resin composition containing 87 to 97 wt% of alumina and 0.1 to 50 wt% of alumina with respect to the inorganic filler (C). 8. An inorganic filler (C) having an alumina content.
1 to 50% by weight of the epoxy resin composition according to claim 7. 9. The epoxy resin composition according to claim 7, wherein the inorganic filler (C) further contains silica. 10. The epoxy resin composition according to claim 9, wherein the content of silica is 50 to 99.9% by weight of the inorganic filler (C). 11. The epoxy resin composition according to claim 7, wherein the epoxy resin (A) contains a biphenyl type epoxy resin (a) having a structure of the following formula (I) as an essential component. Embedded image (However, R1 to R8 in the formula are a hydrogen atom, a carbon number 1 to
4 represents an alkyl group or a halogen atom). 12. The epoxy resin composition according to claim 7, wherein the flame retardancy of the epoxy resin composition after curing the epoxy resin is V-0 in UL standard. 13. The epoxy resin composition according to claim 1, which is used for encapsulating a semiconductor. 14. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition according to claim 1. 15. An inorganic filler (C) containing 0.1 to 20% by weight of an epoxy resin (A), a curing agent (B) and alumina (70 to 97% by weight based on the whole resin composition).
A method for producing an epoxy resin composition, which comprises melt-mixing. 16. An inorganic filler (C) containing 0.1 to 50% by weight of an epoxy resin (A), a curing agent (B) and alumina (87 to 97% by weight based on the whole resin composition).
A method for producing an epoxy resin composition, which comprises melt-mixing.