TW202033656A - Epoxy resin composition - Google Patents

Abstract

The present invention relates to an epoxy resin composition having low dielectric properties for encapsulating a semiconductor device.

Description

Epoxy resin composition

The present invention relates to an epoxy resin composition with low dielectric properties for packaging semiconductor devices.

With the growth of mobile devices and the Internet of Things (IoT), mobile communication technology standards based on this are also developing rapidly. As the world has recently entered the era of 5G communications, research and development of various technologies that require rapid and accurate transmission of large amounts of information have continued. In the current LTE or 4G communication era, the improvement of the materials that make up the printed circuit board (PCB) used for semiconductor packaging has become the focus of attention. However, in the era of 5G communications, it is not only necessary to improve the circuit board used for semiconductor packaging, but also to improve the semiconductor packaging composition.

A semiconductor packaging material is used to protect the internal circuits of semiconductors from external shocks and contaminants. In recent years, semiconductor packaging materials for mobile devices not only need to have basic required characteristics such as heat dissipation and fluidity, but also have to exhibit low dielectric constant (Dk) and low loss factor (Df) in order to reduce high-frequency signal transmission Transmission loss in the process. Therefore, relevant research is actively underway.

For example, Korean Patent Publication No. 10-2014-0127957 discloses that a low-dielectric epoxy resin composition is formed by reacting a phenolic resin and epihalohydrin under an alkaline catalyst. However, the above epoxy resin composition cannot meet the recent mobile communication technology's demand for low dielectric constant (Dk) and low loss factor (Df) characteristics. Therefore, there is a continuous demand for compositions with low dielectric properties for packaging semiconductor devices.

The present invention provides an epoxy resin composition with low dielectric properties and a semiconductor device encapsulated using the epoxy resin composition.

One aspect of the present invention is to provide an epoxy resin composition including an epoxy resin, a curing agent, and a filler, wherein the curing agent includes an ester-based resin.

An epoxy resin composition according to the present invention does have a low dielectric constant and a low loss factor. When applied to a semiconductor device, it can transmit high-frequency signals while realizing fast information transmission, thereby minimizing transmission loss. In addition, the epoxy resin composition according to the present invention has a low moisture absorption rate, and therefore can effectively protect the internal circuit of the semiconductor.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, it should be understood that these descriptions are not intended to limit the present invention to the following content, and various components can be modified in various ways or alternatively used mutually as necessary. Therefore, the purpose of the present invention is to cover all modifications, equivalents, and alternatives that may be included in the spirit and scope of the present invention.

Epoxy resin composition

An epoxy resin composition according to the present invention includes an epoxy resin, a curing agent, and a filler, wherein the curing agent includes an ester-based resin. Similarly, if necessary, the epoxy resin composition according to the present invention may further include a curing accelerator and additives commonly used in the art. Hereinafter, the composition of the epoxy resin composition of the present invention will be described.

Epoxy resin

The epoxy resin composition according to the present invention contains an epoxy resin as the main resin. The epoxy resin is cured by reacting with the curing agent. After curing, the epoxy resin has a three-dimensional network structure, which is endowed with the characteristics of firmly and firmly adhering to the adherend and heat resistance.

As the epoxy resin, epoxy resins generally used in semiconductor device packaging materials can be used without limitation. Non-limiting examples of usable epoxy resins may include bisphenol A-type epoxy resin, cresol novolac-type epoxy resin, and bisphenol F-type epoxy resin. Epoxy resin (bisphenol F-type epoxy resin), bisphenol S-type epoxy resin, naphthalene-type epoxy resin, anthracene epoxy resin , Biphenyl-type epoxy resin, tetramethyl biphenyl-type epoxy resin, phenol novolac-type epoxy resin, double Bisphenol A novolac-type epoxy resin, bisphenol S novolac-type epoxy resin, biphenyl novolac-type epoxy resin epoxy resin), naphthol novolac-type epoxy resin, naphthol phenol coaxial novolac-type epoxy resin, naphthol phenol coaxial novolac-type epoxy resin, naphthol cresol coaxial novolac-type epoxy resin Naphthol cresol coaxial novolac-type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin-type epoxy resin, triphenyl methane-type epoxy resin type epoxy resin), tetraphenyl ethane-type epoxy resin, dicyclopentadiene-type epoxy resin, dicyclopentadiene-type epoxy resin, dicyclopentadiene phenol addition reaction type ring Dicyclopentadiene phenol addition react ion-type epoxy resin), phenol aralkyl-type epoxy resin, multi-functional phenolic resin and naphthol aralkyl-type epoxy resin epoxy resin), but not limited to one or more.

The epoxy resin can have an epoxy equivalent weight (EEW) between 100 g/eq and 400 g/eq, such as between 150 g/eq and 300 g/eq; the softening point is between 30 ^o C and 150 ^oC Between, for example, between 40 ^o C to 130 ^oC ; viscosity (measured at 150 ^oC ) between 0.01 poise (poise) to 30 poise (poise), for example, between 0.02 poise (poise) to 20 poise (Poise) between. Such epoxy resin has relatively low viscosity characteristics, and therefore, even if it contains a high content of filler, fluidity can be ensured and kneading can be easily performed.

When the epoxy equivalent of the epoxy resin is less than 100 g/eq, the fluidity will be significantly reduced, and when it is greater than 400 g/eq, the glass transition temperature (Tg) may decrease and the thermal expansion coefficient may increase. In addition, when the softening point and viscosity of the epoxy resin exceed the above ranges, the dispersibility may be deteriorated.

Based on the total weight of the epoxy resin composition, the content of the epoxy resin may be between 1 weight percent (wt%) and 20 weight percent (wt%), for example, between 1 wt% and 10 wt%. When the content of the epoxy resin is less than 1 wt%, adhesion, electrical insulation, fluidity, and moldability may be deteriorated. When its content is greater than 20 wt%, the reliability of the semiconductor may be deteriorated due to an increase in moisture absorption, and heat dissipation characteristics may be deteriorated due to a decrease in the relative content of fillers.

Hardener

The epoxy resin composition according to the present invention contains a curing agent. The curing agent promotes the curing of the composition by reacting with the epoxy resin.

The epoxy resin composition according to the present invention contains an ester-based resin as a curing agent. The ester-based resin can be used as long as it is a resin containing an ester bond in the main chain of the constituent molecule, and is not particularly limited. For example, the ester-based resin can be a carboxylic acid compound, a glycol compound, or a carboxylic acid compound under a catalyst and a solvent. It is polymerized with phenolic compounds.

The kind of carboxylic acid compound is not particularly limited. For example, it can be selected from terephthalic acid (terephthalic acid), isophthalic acid (isophthalic acid), 1,4-cyclohexane dicarboxylic acid (1,4-cyclohexane dicarboxylic acid), adipic acid (adipic acid). ), sebacic acid, phthalic anhydride, trimellitic anhydride, benzoic acid, and tetrahydrophthalic anhydride .

The kind of ethylene glycol compound is not particularly limited. For example, it may be selected from ethylene glycol, propylene glycol, 1,2-butylene glycol, neopentyl glycol, 1,6-hexane One or more of 1,6-haxanediol and glycerol.

The kind of phenol compound is not particularly limited. For example, it can be selected from phenol, cresol, pt-butylphenol, 1-naphthol, 2-naphthol, o-benzene One or more of catechol (catechol), resorcinol (resorcinol), and hydroquinone (hydroquinone).

The ester-based resin may have a hydroxyl equivalent (OH) between 50 g/eq and 400 g/eq, for example, between 100 g/eq and 300 g/eq; the softening point is between 25 ^o C and 130 ^o C Between, for example, between 50 ^o C to 100 ^o C; viscosity (measured at 150 ^oC ) between 0.1 poise (poise) to 3 poise (poise), for example, between 0.3 poise (poise) to 1.5 Between poise. When the hydroxyl equivalent (OH) of the ester-based resin is greater than 400 g/eq, the curing density after the curing reaction is reduced, and thus reliability may be deteriorated. When it is less than 50 g/eq, the rate of curing reaction increases, so that the rate of gel formation is high and stability may be deteriorated. When the softening point is higher than 130 ^o C, the viscosity increases and the fluidity deteriorates, which may cause moldability defects. When it is less than 25 ^o C, the dispersibility deteriorates, and the yield may decrease due to agglomeration. When the viscosity is greater than 3 poise, fluidity deteriorates, which may cause moldability defects. When it is less than 0.1 poise, the dispersibility is deteriorated, and the yield may decrease due to agglomeration.

The epoxy resin composition according to the present invention may further include a phenolic resin as a curing agent. Non-limiting examples of usable phenolic resins may include phenol novolac-type resins, cresol novolac-type resins, and phenol alkyl resins. One or more of phenol xylok-type resins and various novolac-type resins synthesized from bisphenol A.

Phenolic resin may have a hydroxyl (OH) equivalent between 50 g/eq and 200 g/eq, for example between 80 g/eq and 150 g/eq; softening point between 50 ^o C and 150 ^o C Between, for example, between 60 ^o C and 100 ^o C; viscosity (measured at 150 ^oC ) between 0.5 poise (poise) to 2.5 poise (poise), for example, between 1.0 poise (poise) to 2.0 poise (Poise) between. When the hydroxyl (OH) equivalent, softening point, and viscosity of the phenol resin exceed the above-mentioned ranges, the dispersibility and fluidity of the epoxy resin composition may deteriorate.

For example, the weight mixing ratio of the ester-based resin and the phenolic resin may be between 1:0.1 and 1:5, for example, between 1:0.1 and 1:3. When the weight mixing ratio of the ester-based resin and the phenolic resin satisfies the above range, the corrosion resistance and adhesion can be improved, and a low dielectric constant and dissipation factor can be ensured.

Based on the total weight of the epoxy resin composition, the content of the curing agent may comprise between 1 wt% and 20 wt%, for example between 1 wt% and 10 wt%. When the content of the curing agent is less than 1 wt%, curability and moldability will become problems. And when it is more than 20wt%, due to the increase in moisture absorption, reliability may be deteriorated, and strength may become relatively low.

Filler

The epoxy resin composition according to the present invention contains a filler. The filler is used to improve the heat dissipation and strength of the packaging material, and reduce the moisture absorption.

It can be used alone or in combination with two or more of its inorganic fillers as fillers, such as silicon dioxide (silica), silicon nitride (silica nitride), alumina (alumina), aluminum nitride (aluminum nitride) , Boron nitride, etc.

For example, the epoxy resin composition according to the present invention can include spherical silica as a filler, and can use, for example, spherical silica with an average particle diameter between 5 μm and 30 μm. When the spherical silica has the above-mentioned average diameter distribution, sufficient processability can be obtained, and at the same time, excellent heat dissipation can be ensured.

Based on the total weight of the epoxy resin composition, the content of the filler may include between 70 wt% and 95 wt%, for example, between 80 wt% and 95 wt%. When the content of the filler is less than 70 wt%, due to an increase in moisture absorption, strength may be deteriorated and adhesiveness may be reduced. When the content of the filler is greater than 95 wt%, processability may deteriorate due to increase in viscosity and deterioration in fluidity.

Curing accelerator

The epoxy resin composition according to the present invention may include a curing accelerator. The curing accelerator is used to promote the curing reaction and improve the high temperature reliability and continuous processability cycle.

The curing accelerator used in the present invention can be used as long as it can promote the curing reaction of the curing agent, and is not particularly limited. For example, the curing accelerator may be selected from such as 2-methylimidazole (2-methylimidazole), 2-ethyl-4-methylimidazole (2-ethyl-4-methylimidazole), 2-phenylimidazole (2-phenylimidazole) ), (4-methyl-2-phenyl-1H-imidazol-5-yl)methanol ((4-methyl-2-phenyl-1H-imidazol-5-yl)methanol) imidazole compounds, such as triethylamine ( triethylamine), tributylamine (tributylamine), benzyldimethylamine (benzyldimethylamine) amine compounds, such as 2-(dimethylaminomethyl)phenol (2-(dimethylaminomethyl)phenol), 2,4,6- Tris (dimethylaminomethyl) phenol (2,4,6-tris (dimethylaminomethyl)phenol), and 1,8-diazebicyclo(5,4,0)undec-7-ene (1,8- diazabicyclo(5,4,0) undec-7-ene) tertiary amine compound, and phenylphosphine, diphenylphosphine, triphenylphosphine, tributyl One or more of tributylphosphine and tri(p-methylphenyl)phosphine.

Based on the total weight of the epoxy resin composition, the content of the curing accelerator may be comprised between 0.01 wt% and 5 wt%, for example between 0.01 wt% and 2 wt%. When the content of the curing accelerator is less than 0.01 wt%, curability may be deteriorated. And when it is more than 5 wt%, fluidity may be deteriorated due to excessive curing.

additive

In addition to the above-mentioned components, if necessary, the epoxy resin composition according to the present invention may further optionally contain additives generally known in the art. Non-limiting examples of additives that can be used in the present invention may include selected from coupling agents, colorants, defoamers, leveling agents, adhesion modifiers, flame retardants, light absorbers, desiccants, moisture absorbents, and One or more of waxes.

The coupling agent is a material for enhancing the adhesiveness of the coating film, and silicon-based compounds such as mercaptoalkylalkoxysilane and gamma-glydoxypropyltrimethoxysilane can be used. It is known in the art that typical colorants such as carbon black, bengala, organic dye, and inorganic dye can be used alone or in combination of two or more of them as colorants . Paraffin wax, natural wax, synthetic wax, or a mixture thereof may be used as the wax. Natural waxes include carnauba wax, and synthetic waxes include polyethylene wax.

Based on the total weight of the epoxy resin composition, the content of the additives is not particularly limited, but may be between 0.1 wt% and 5 wt%.

The manufacturing method of the epoxy resin composition of this invention is not specifically limited, It can manufacture using the method known in this field. For example, a melt-kneading method such as a banbury mixer, a kneader, a drum, a single-shaft or twin-shaft extruder, and a co-kneader can be used. For example, the above-mentioned components are mixed uniformly, and then using a heat kneader to melt-mixing the mixture at a temperature of 100 ^o C to 130 ^o C is. The mixture is then cooled to room temperature and ground into a powder state, and then blended to produce an epoxy resin composition.

Semiconductor device

The present invention provides a semiconductor device encapsulated using the epoxy resin composition. Specifically, a semiconductor device to which the composition of the present invention can be applied refers to an electronic circuit (integrated circuit) made by integrating and wiring transistors, diodes, resistors, capacitors, etc. on a semiconductor chip or substrate.

The method of encapsulating and manufacturing a semiconductor device using the epoxy resin composition of the present invention is not particularly limited. The semiconductor device can be manufactured by packaging by using a molding method such as transfer molding, compression molding, or injection molding.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only descriptions of the present invention, and are not intended to limit the scope of the present invention.

Example 1 to Example 6

According to the composition shown in Table 1 below, the components were mixed using a container mixer, and then pressed into a predetermined size by melt mixing, cooling, grinding, and blending to prepare examples 1 to 6 Epoxy resin composition. The units used in Table 1 below are weight percentages.

Comparative example 1 to comparative example 4

Except for using the composition shown in Table 2 below, the epoxy resin composition of Comparative Example 1 to Comparative Example 4 was prepared in the same manner as in Example 1 to Example 6. The units used in Table 2 below are weight percentages.

Table 1 Example 1 2 3 4 5 6 Epoxy resin 5.91 5.60 5.26 4.60 6.08 6.09 Curing agent 1-1 1.14 2.06 3.12 5.12 0.63 0.6 Curing agent 2 2.67 2.06 1.34 3.01 3.03 Filler 89.5 89.5 89.5 89.5 89.5 89.5 Coupling agent 0.4 0.4 0.4 0.4 0.4 0.4 Colorant 0.2 0.2 0.2 0.2 0.2 0.2 wax 0.1 0.1 0.1 0.1 0.1 0.1 Curing accelerator 0.08 0.08 0.08 0.08 0.08 0.08 total 100 100 100 100 100 100

Table 2 Comparative example 1 2 3 4 Epoxy resin 6.29 4.96 5.6 5.91 Curing agent 1-2 2.26 1.14 Curing agent 1-3 2.26 2.06 Curing agent 2 3.43 0.24 2.06 2.67 Filler 89.5 89.5 89.5 89.5 Coupling agent 0.4 0.4 0.4 0.4 Colorant 0.2 0.2 0.2 0.2 wax 0.1 0.1 0.1 0.1 Curing accelerator 0.08 0.08 0.08 0.08 total 100 100 100 100

Epoxy resin: 4,4-bis(2,3-epoxypropoxy)-3,3,5,5-tetramethyl(1,1-biphenyl) (4,4-bis (2,3 -epoxypropoxy)-3,3,5,5-tetramethyl(1,1-biphenyl)) (YK-4000HK, Mitsubishi Chemical Corporation, epoxy equivalent: 192 g/eq, softening point: 109 ^o C, viscosity (at 150 ^o Measured at C): 0.2 poise)

Curing agent 1-1: ester-based resin (OH equivalent: 209 g/eq, softening point: 78 ^o C, viscosity (measured at 150 ^o C): 0.6 poise)

Curing agent 1-2: ester-based resin (OH equivalent: 185 g/eq, softening point: 135 ^o C, viscosity (measured at 150 ^o C): 1.8 poise)

Curing agent 1-3: ester-based resin (OH equivalent: 169 g/eq, softening point: 152 ^o C, viscosity (measured at 150 ^o C): 1.6 poise)

Curing agent 2: Phenolic resin (phenol polymer with hydroxybenzaldehyde, MEH-7500-3S, Meiwa Kasei Co.), OH equivalent: 103 g/eq, softening point: 83 ^o C, viscosity ( Measured at 150 ^o C): 1.4 poise)

Filler: spherical silica (average particle size is 15 μm)

Coupling agent: 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane (KBM-403, ShinEtsu Co.), specific gravity (25 ^o C): 1.070, flash point: 135 ^o C, refractive index (25 ^o C): 1.429, boiling point ( ^o C/mmHg): 120/2)

Coloring agent: carbon black (MA-600, Mitsubishi Chemical Corporation, maximum cutting size: 20 nm)

Wax: Polyethylene wax (Wax E, Clariant Co., dropping point: 84 ^oC , acid value: 2-7 mgKOH / g)

Curing accelerator: (4-methyl-2-phenyl-1H-imidazol-5-yl) methanol (2P4MHZ-PW, four Shikoku Co., melting point: 240 ^o C, molecular weight: 152 g/mol)

Experimental example-characteristic evaluation

The properties of the epoxy resin composition prepared according to each of Examples 1 to 6 and Comparative Examples 1 to 4 will be measured below, and the results are shown in Table 3 and Table 4 below.

Prepare samples

The epoxy resin composition prepared according to each of Examples 1 to 6 and Comparative Example 1 to Comparative Example 4 was transfer molded at 175 ^o C using a heat transfer molding device for 70 seconds to produce a diameter of 33 mm and 2.5 mm high module, then the module is molded and cured (PMC) at 175 ^o C for 4 hours, and then cooled to room temperature.

Introduce Electric constant ( Dk ) And loss factor ( Df )

Under the conditions of 30 ^o C, 1 Hz and 1.5 V, use a dielectric characteristic measuring device (Impedance Analyzer, Novocontrol Co.) to evaluate the dielectric constant (Dk) and dissipation factor (Df).

Moisture absorption rate ( % )

Under PCT conditions (121 ^o C, 2 atmospheres, 100% relative humidity (%RH)), the moisture absorption rate is evaluated by comparing the weight before and after the sample is left standing for 24 hours.

Spiral flow

Using the EMMI-I-66 standard spiral flow mold, the spiral flow is measured by a heat transfer molding device (pressure: 70 kg/cm ² , temperature: 175 ^o C, curing time: 120 seconds).

Gel time

A small amount of epoxy resin composition prepared according to each of Example 1 to Example 6 and Comparative Example 1 to Comparative Example 4 was evenly spread on a gel timer to measure the gel time of the product.

Thermal expansion coefficient( α Puffy, αα )

Use a sample manufacturing mold (width: 60 mm, length: 10 mm, thickness: 3 mm) in a heat transfer molding device (pressure: 70 kg/cm ² , temperature: 175 ^o C, curing time: 120 seconds) for molding Then, it was molded and cured in an oven at 175 ^o C for 4 hours. After that, the sample was cut to a width of 10 mm, a length of 10 mm, and a thickness of 3 mm, and the thermal expansion coefficient was measured with a thermomechanical analyzer (TMA).

Glass transition temperature

Use a sample manufacturing mold (width: 60 mm, length: 10 mm, thickness: 3 mm) in a heat transfer molding device (pressure: 70 kg/cm ² , temperature: 175 ^o C, curing time: 120 seconds) for molding , And then molded and cured in a 175 ^o C oven for 4 hours. After that, the sample was cut (width 10 mm, length 10 mm, and thickness 3 mm), and the glass transition temperature was measured with a thermomechanical analyzer (TMA).

Flexural modulus

Use a sample manufacturing mold (width: 125 mm, length: 12.5 mm, thickness: 6 mm) in a heat transfer molding device (pressure: 70kg/cm ² , temperature: 175 ^o C, curing time: 120 seconds) for molding, Then it was molded and cured in an oven at 175 ^oC for 4 hours, and then the flexural modulus was measured with a universal testing machine (UTM).

Mold shrinkage

Use a sample manufacturing mold (width: 125 mm, length: 12.5 mm, thickness: 6 mm) in a heat transfer molding device (pressure: 70kg/cm ² , temperature: 175 ^o C, curing time: 120 seconds) for molding, It was then molded and cured in an oven at 175 ^o C for 4 hours, and then the length of the shrink sample was measured using a vernier caliper.

Hot hardness

Immediately after the spiral flow mold, a Shore-D hardness tester was used to measure the hot hardness on the surface of the cured product on the upper part of the mold.

table 3 Example 1 2 3 4 5 6 Dielectric constant (Dk) 4.4 4.5 4.3 4.1 4.7 4.7 Dissipation factor (Df) 0.06 0.02 0.01 0.01 0.1 0.13 Moisture absorption rate (%) 0.31 0.3 0.27 0.25 0.33 0.36 Spiral flow (inch) 45 49 52 79 43 43 Gel time (sec) 70 78 81 154 65 63 Coefficient of thermal expansion (α1) 7.8 8.2 8 8.4 7.6 7.5 Coefficient of thermal expansion (α2) 35 37 38 40 34 34 Glass transition temperature (°C) 161 131 126 124 163 165 Flexural modulus (kgf/mm ² ) 2,260 2,460 2,540 2,710 2,220 2,220 Mold shrinkage (%) 0.03 0.05 0.07 0.08 0.03 0.03 Hot hardness 80 68 67 50 80 80

Table 4 Comparative example 1 2 3 4 Dielectric constant (Dk) 4.9 4.9 4.8 5.1 Dissipation factor (Df) 0.16 0.04 0.03 0.19 Moisture absorption rate (%) 0.45 0.32 0.4 0.4 Spiral flow (inch) 40 48 50 47 Gel time (sec) 60 75 80 73 Coefficient of thermal expansion (α1) 7.3 8.6 8.4 7.9 Coefficient of thermal expansion (α2) 32 38 39 36 Glass transition temperature (°C) 170 119 120 155 Flexural modulus (kgf/mm ² ) 2,200 2,850 2,800 2,300 Mold shrinkage (%) 0.02 0.12 0.11 0.04 Hot hardness 82 65 60 70

As shown in Table 3 and Table 4 above, it is confirmed that the epoxy resin composition prepared according to each of Examples 1 to 6 of the present invention exhibits excellent effects on all measured properties. In particular, compared with the epoxy resin composition prepared in each of Comparative Examples 1 to 4 in which no ester-based resin was used according to the present invention, it was confirmed that the epoxy resin compositions of Examples 1 to 6 have Lower dielectric constant and lower dissipation factor. Furthermore, it was confirmed that the epoxy resin composition according to the present invention can minimize the moisture absorption rate.

no

no

Claims (5)

An epoxy resin composition comprising: an epoxy resin; a curing agent; and a filler; wherein the curing agent comprises an ester-based resin, and the ester-based resin has a hydroxyl (OH) equivalent of 50 g /eq to 400 g/eq and a softening point between 25 ^o C and 130 ^o C. The epoxy resin composition according to claim 1, wherein the curing agent further includes a phenolic resin. The epoxy resin composition according to claim 2, wherein the weight mixing ratio of the ester-based resin and the phenol resin is 1:0.1 to 5. The epoxy resin composition according to claim 1, wherein based on the total weight of the epoxy resin composition, the epoxy resin composition includes: 1 to 20 weight percent of the epoxy resin; 1 to 20 weight percent of the curing agent; and 70 to 95 weight percent of the filler. A semiconductor device characterized by using the epoxy resin composition according to any one of claims 1 to 4 for encapsulation.