JP2011026501A - Epoxy resin composition for sealing semiconductor and semiconductor device having semiconductor element sealed by using the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing a semiconductor, which has excellent fluidity when melted and excellent warp resistance of a package. <P>SOLUTION: The epoxy resin composition for sealing the semiconductor contains an epoxy resin of 2-15 mass% of the total mass of the epoxy resin composition and a flexibilizer of 0.8-4.5 mass% of the total mass thereof. The epoxy resin contains a bisphenol A type epoxy resin which is shown by formula (1) and is of 30-100 mass% of the total mass of the epoxy resin. The flexibilizer contains amino-modified silicone which is shown by formula (2) and is of 50-100 mass% of the total mass of the flexibilizer. The epoxy resin composition for sealing the semiconductor has the excellent fluidity when melted and the excellent warp resistance of the package. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition for semiconductor sealing used for sealing a semiconductor element mounted on a substrate for mounting a semiconductor element, and a semiconductor device in which a semiconductor element is sealed using the composition.

  Conventionally, an epoxy resin composition is widely known as a material used for sealing a semiconductor element (chip) mounted on a semiconductor element mounting substrate. Generally this epoxy resin composition contains a hardening | curing agent, an inorganic filler, a flexible agent, etc. other than an epoxy resin (refer patent document 1). A semiconductor device in which a semiconductor element is sealed and protected using this resin composition is called a package, and is mounted on a printed wiring board. The package is usually manufactured by transfer molding using a mold.

  In transfer molding, the epoxy resin composition is injected under pressure into a cavity in a molten state. A substrate on which a semiconductor element is mounted is placed in the cavity. The substrate and the semiconductor element are already electrically connected (wire bonding) with a gold wire. The molten epoxy resin composition flows in the cavity while wrapping the semiconductor element on the substrate, and fills the cavity. After several hours of post-curing (post cure), the mold is opened and the molding or package is removed.

  In recent years, along with the downsizing and thinning of electronic devices, thinning of gold wires for electrically connecting a substrate and a semiconductor element has become remarkable. As a result, a wire sweep is likely to occur in which the gold wire is deformed by receiving pressure from the molten epoxy resin composition flowing in the cavity during transfer molding. In order to reduce this wire sweep, it is proposed to increase the fluidity of the molten epoxy resin composition during transfer molding. Therefore, it is known to use a bisphenol A type epoxy resin having a relatively low viscosity when melted for an epoxy resin composition for semiconductor encapsulation (Patent Document 2).

Japanese Patent Laid-Open No. 11-1000048 (paragraphs 0009 and 0011) JP 2006-176595 A (paragraphs 0014 and 0015)

  By the way, with the downsizing and thinning of electronic devices, the surface mount type that is mounted on the surface of a printed wiring board has become the mainstream. Among surface mount packages, BGA (Ball Grid Array), which is an area mount type with a high mounting density, is widely used. Since BGA is a single-side sealed package in which only one side of a substrate on which a semiconductor element is mounted is sealed with an epoxy resin composition, the difference in thermal expansion coefficient between the substrate and the epoxy resin composition (the heat of the epoxy resin composition) There is a problem of warping of the package due to the expansion coefficient being larger than the thermal expansion coefficient of the substrate (especially easily occurring at the time of cooling after molding or reflowing exposed to a high temperature).

  If a bisphenol A type epoxy resin having a relatively low viscosity at the time of melting is used to reduce wire sweep at the time of transfer molding, the thermal expansion coefficient of the epoxy resin composition becomes larger, and the warpage of the package is reduced. The problem of increasing problems arises.

  The present invention addresses the above problems in the epoxy resin composition for semiconductor encapsulation, while using a bisphenol A type epoxy resin having a relatively low viscosity at the time of melting in order to reduce wire sweep, It is an object of the present invention to provide an epoxy resin composition for semiconductor encapsulation that can suppress package warpage.

  That is, this invention is an epoxy resin composition for semiconductor encapsulation containing an epoxy resin and a flexible agent, the epoxy resin is contained in 2 to 15% by mass in the total amount of the epoxy resin composition, and the flexible agent is an epoxy resin. The resin composition contains 0.8 to 4.5% by mass in the total amount of the resin composition, and the epoxy resin contains 30 to 100% by mass of the bisphenol A type epoxy resin represented by the following formula (1) in the total epoxy resin. The above-mentioned flexible agent is an epoxy resin composition for semiconductor encapsulation, which contains 50 to 100% by mass of the amino-modified silicone represented by the following formula (2) in the total flexible agent.

  In this invention, it is preferable to contain 70-90 mass% of inorganic fillers further in an epoxy resin composition whole quantity.

  Moreover, this invention is a semiconductor device with which the semiconductor element mounted in the board | substrate for semiconductor element mounting is sealed with said epoxy resin composition for semiconductor sealing.

  ADVANTAGE OF THE INVENTION According to this invention, the epoxy resin composition for semiconductor sealing excellent in the fluidity | liquidity at the time of a fusion | melting and the curvature resistance of a package is provided. As a result, there is an effect that wire sweep reduction during transfer molding and suppression of package warpage can be achieved at the same time.

The present invention is characterized by the following points in an epoxy resin composition for semiconductor encapsulation containing an epoxy resin and a flexible agent.
(A) 2-15 mass% of epoxy resins are contained in the total amount of the epoxy resin composition.
(B) The said epoxy resin contains 30-100 mass% of bisphenol A type epoxy resins shown by following formula (1) in all the epoxy resins.
(C) A flexible agent is contained in an amount of 0.8 to 4.5% by mass in the total amount of the epoxy resin composition.
(D) The said flexible agent contains 50-100 mass% of amino modified silicone shown by following formula (2) in all the flexible agents.

  First, (a) and (b) will be described. The bisphenol A type epoxy resin represented by the formula (1) (hereinafter simply referred to as “epoxy resin of the formula 1”) has a property that the viscosity at the time of melting is relatively low. Therefore, by using the epoxy resin of Formula 1, the fluidity of the molten epoxy resin composition at the time of transfer molding is enhanced, and the wire sweep at the time of transfer molding is reduced.

As the epoxy resin of Formula 1, for example, the following are commercially available and can be suitably used in the present invention.
"YL6810" (Viscosity (25 ° C) (P / Gardner Holt): 40 to 55, Epoxy equivalent: 165 to 180) manufactured by Japan Epoxy Resin Co., Ltd.

  In the present invention, the content of the epoxy resin in the total amount of the epoxy resin composition is 2 to 15% by mass, preferably 3 to 15% by mass, more preferably 6 to 15% by mass. The content of the epoxy resin in all epoxy resins is 30 to 100% by mass, preferably 50 to 100% by mass, and more preferably 70 to 100% by mass. In terms of this, in the present invention, the content of the epoxy resin of Formula 1 in the total amount of the epoxy resin composition is 0.6 to 15% by mass, preferably 0.9 to 15% by mass, more preferably 1.8. ˜15 mass%. By setting each of the above contents within the above range, the fluidity at the time of melting of the epoxy resin composition is reliably increased, and a better result can be obtained from the viewpoint of reducing wire sweep at the time of transfer molding.

  In the present invention, a conventionally known epoxy resin can be used as an epoxy resin used in combination with the epoxy resin of formula 1, and as such an epoxy resin, for example, an epoxy of formula 1 such as a bisphenol F type epoxy resin can be used. Bisphenol type epoxy resin other than resin, Cresol novolak type epoxy resin such as O-cresol novolak type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, phenylene type epoxy resin, Examples include phenol novolac type epoxy resins, stilbene type epoxy resins, triphenolmethane type epoxy resins, phenol aralkyl type epoxy resins, and triphenylmethane type epoxy resins. These may be used singly or in combination of two or more. Of these, bisphenol type epoxy resins, biphenyl type epoxy resins, and triphenylmethane type epoxy resins are particularly preferable.

  Next, (c) and (d) will be described. The amino-modified silicone represented by formula (2) (hereinafter simply referred to as “flexible agent of formula 2”) has the property of improving the flexibility of the epoxy resin composition. Therefore, by using the flexible agent of Formula 2, the cured epoxy resin composition follows the expansion and contraction of the substrate well, and the warpage of the package is suppressed.

  Here, the flexible agent of formula 2 is dimethyl (aminoethylaminopropyl) methylsiloxane, and in the above formula (2), m and n are integers of 1 or more. The amino equivalent is adjusted to a value in the range of 200 to 10,000. Specifically, for example, m is 100 to 1000, preferably 300 to 800, more preferably 500, and n is 1 to 50, preferably 5 to 20, and more preferably 10.

As the flexible agent of Formula 2, for example, the following are commercially available, and any of them can be suitably used in the present invention.
“Shin-Etsu Chemical Co., Ltd.” “KF-861” (viscosity (25 ° C.): 3500 mm ² / s, specific gravity (25 ° C.): 0.98, amino equivalent: 2000)
-"BY16-849" manufactured by Toray Dow Corning (viscosity (25 ° C): 1300 mm ² / s, specific gravity (25 ° C): 0.98, amino equivalent: 600)

  In the present invention, the content of the flexible agent in the total amount of the epoxy resin composition is 0.8 to 4.5% by mass, preferably 1 to 4.5% by mass, more preferably 2 to 4.5% by mass. In that case, the content of the flexible agent of Formula 2 in the total flexibility is 50 to 100% by mass, preferably 60 to 100% by mass, and more preferably 70 to 100% by mass. In terms of this, in the present invention, the content of the flexible agent of Formula 2 in the total amount of the epoxy resin composition is 0.4 to 4.5% by mass, preferably 0.5 to 4.5% by mass. Preferably it is 1 to 4.5 mass%. By setting each of the above contents within the above range, the cured epoxy resin composition reliably follows the expansion and contraction of the substrate, and a better result is obtained from the viewpoint of suppressing the warpage of the package.

  In the present invention, a conventionally known flexible agent can be used as a flexible agent used in combination with the flexible agent of Formula 2, and examples of such a flexible agent include epoxy-modified silicone and carboxyl-modified silicone. Alternatively, silicone oil other than the flexible agent of formula 2, such as carbinol-modified silicone, silicone elastomer, silicone gel, silicone rubber, and the like can be given. These may be used singly or in combination of two or more. Of these, silicone oil is particularly preferred.

  In the present invention, by using a combination of the epoxy resin of the formula 1 and the flexible agent of the formula 2, there is provided an epoxy resin composition for semiconductor encapsulation which is excellent in both fluidity at the time of melting and warping resistance of the package. Is done. On the other hand, when the epoxy resin of Formula 1 and a flexible agent other than the flexible agent of Formula 2 are used in combination, not only the warpage resistance of the package is lowered, but also melting. At the same time, the fluidity is also reduced (see Example 3 and Comparative Example 3 in Table 1 described later). In addition, when an epoxy resin other than the epoxy resin of formula 1 and the flexible agent of formula 2 are used in combination, not only the fluidity at the time of melting is lowered but also the warping resistance of the package. The properties also decrease at the same time (see also Example 6 and Comparative Example 6). In other words, by using the epoxy resin of formula 1 and the flexible agent of formula 2 in combination, when the epoxy resin of formula 1 and a flexible agent other than the flexible agent of formula 2 are used in combination, The synergistic effect of improving both the fluidity at the time of melting and the warping resistance of the package can be obtained as compared with the case where the epoxy resin other than the epoxy resin 1 is used in combination with the flexible agent of the formula 2.

  The reason is not necessarily clear, but the epoxy resin of Formula 1 has the property of improving the flexibility of the epoxy resin composition as well as the property of relatively low viscosity when melted, and / or Alternatively, since the flexibility of Formula 2 has the property of improving the flexibility of the epoxy resin composition and the property of relatively low viscosity at the time of melting, the epoxy resin of Formula 1 and Formula 2 When used in combination with a flexible agent, they interact with each other, and it is considered that the fluidity at the time of melting and the warpage resistance of the package, which are superior to each other, are combined.

  Moreover, in this invention, you may make an epoxy resin composition contain an inorganic filler other than an epoxy resin and a flexible agent. Since the inorganic filler has a relatively small coefficient of thermal expansion, the inclusion of the inorganic filler in the epoxy resin composition reduces the coefficient of thermal expansion of the epoxy resin composition, which is advantageous in terms of warping resistance of the package. work. However, when an inorganic filler is contained in a large amount in the epoxy resin composition, there is a disadvantage that the fluidity at the time of melting of the epoxy resin composition is lowered. Therefore, the content of the inorganic filler in the total amount of the epoxy resin composition is 70 to 90% by mass, preferably 70 to 85% by mass, more preferably from the viewpoint of the balance between the fluidity at the time of melting and the warpage resistance of the package. Is 70-80 mass%. By setting the content within the above range, better results can be obtained from the viewpoint of the balance between the fluidity during melting and the warpage resistance of the package.

  In the present invention, conventionally known inorganic fillers can be used. Examples of such inorganic fillers include fused silica, crystalline silica, alumina, and silicon nitride. These may be used singly or in combination of two or more. Of these, fused silica is particularly preferable from the viewpoint of fluidity. Further, spherical ones, those close to true spheres, and those having an average particle size of 7 to 15 μm and a maximum particle size of 74 μm are more preferable.

  In the present invention, conventionally known curing agents can be used. Examples of such curing agents include various types of phenol novolak resins, cresol novolak resins, phenol aralkyl resins, biphenyl aralkyl resins, naphthol aralkyl resins, and the like. And polyhydric phenol compounds or naphthol compounds. These may be used singly or in combination of two or more.

  In the present invention, the content of the curing agent in the epoxy resin composition is not particularly limited, but in terms of the blending ratio with the epoxy resin, the total epoxy resin / total curing agent (equivalent ratio of epoxy equivalent and hydroxyl equivalent) ) = 0.8 to 1.4, preferably 0.9 to 1.2. If this blending ratio is excessively small, the curing agent tends to be excessive, which tends to be economically disadvantageous. If the blending ratio is excessively large, the curing agent tends to be insufficient, resulting in insufficient curing.

  In the present invention, conventionally known curing accelerators, mold release agents, silane coupling agents, colorants, flame retardants, ion trapping agents and the like may be further contained in the epoxy resin composition.

  The curing accelerator is for accelerating the reaction (curing reaction) between the epoxy group of the epoxy resin and the hydroxyl group of the curing agent. For example, organic compounds such as triphenylphosphine, tributylphosphine, tetraphenylphosphonium / tetraphenylborate Phosphines, tertiary amines such as 1,8-diaza-bicyclo (5,4,0) undecene-7 (DBU), triethylenediamine, benzyldimethylamine, 2-methylimidazole, 2-ethyl-4- Imidazoles such as methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole can be used. These may be used singly or in combination of two or more.

  As for content of the hardening accelerator to an epoxy resin composition, 0.4-3 mass% is preferable with respect to all the resin components (total amount of all the epoxy resins and all the hardening | curing agents). When there is less content of a hardening accelerator than this, there exists a tendency for a hardening acceleration effect to be insufficient, and when more than this, there exists a tendency for a malfunction to arise in a moldability.

  Examples of the release agent that can be used in the present invention include high melting point waxes such as carnauba wax and montan wax, higher fatty acids such as stearic acid and salts and esters thereof, and carboxyl group-containing polyolefins. These may be used singly or in combination of two or more. Content of the mold release agent to an epoxy resin composition is 0.1-0.5 mass% in the epoxy resin composition whole quantity, for example.

  As the silane coupling agent, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and the like can be used. As the colorant, for example, carbon black or various pigments can be used. As the halogen-free or antimony-free flame retardant, for example, metal hydroxide (metal hydrate) such as magnesium hydroxide, aluminum hydroxide, or calcium hydroxide can be used.

  The epoxy resin composition for semiconductor encapsulation of the present invention is prepared, for example, as follows. That is, an epoxy resin, a curing agent, an inorganic filler, a flexible agent, and other components are blended in predetermined amounts, mixed uniformly with a mixer or blender, and then kneaded while heating with a kneader or roll. And it cools and solidifies after kneading | mixing, It grind | pulverizes as needed and it is set as a powdery or granular epoxy resin composition.

  The semiconductor device of the present invention is manufactured, for example, as follows. That is, after mounting a semiconductor element on a semiconductor element mounting substrate and electrically connecting the substrate and the semiconductor element with a gold wire (wire bonding), the semiconductor element on the substrate is made of the epoxy resin composition for semiconductor encapsulation of the present invention. Seal. To perform this sealing, transfer molding using a mold can be employed. That is, after a substrate on which a semiconductor element is mounted and wire-bonded is placed in a cavity of a mold, a molten epoxy resin composition is injected into the cavity with a predetermined pressure to fill the cavity. The injection pressure at this time is set to, for example, 4 to 7 MPa, the mold temperature is set to, for example, 160 to 190 ° C., and the molding time is set to, for example, 45 to 300 seconds (according to the type of epoxy resin composition or semiconductor device). Can be changed as appropriate). Next, after the mold is closed, post-curing is performed, and then the mold is opened to take out a molded product, that is, a semiconductor device (package). The post-curing conditions at this time are set to, for example, 2 to 8 hours at 160 to 190 ° C. (can be appropriately changed according to the type of the epoxy resin composition and the semiconductor device).

  Hereinafter, the present invention will be described more specifically through examples, but the present invention is not limited to these examples.

  In the formulation (% by mass) shown in Table 1, each component such as an epoxy resin, a curing agent, an inorganic filler, and a flexible agent is mixed and homogenized for 30 minutes with a blender, and then melted with two rolls heated to 80 ° C. The mixture was kneaded while being extruded, extruded, cooled, and then pulverized to a predetermined particle size by a pulverizer to prepare a powdery epoxy resin composition for semiconductor encapsulation.

The materials used in Examples 1 to 7 and Comparative Examples 1 to 7 are as follows.
(Epoxy resin 1)
-Epoxy resin of formula 1: “YL6810” (epoxy equivalent 175) manufactured by Japan Epoxy Resin Co., Ltd.
(Epoxy resin 2)
Biphenyl type epoxy resin: “YX4000H” (epoxy equivalent 195) manufactured by Japan Epoxy Resin Co., Ltd.
(Epoxy resin 3)
Bisphenol type epoxy resin: “YSLV-80XY” (epoxy equivalent 195) manufactured by Tohto Kasei Co., Ltd.
(Curing agent)
Phenol novolac resin: “DL-92” (hydroxyl equivalent: 105) manufactured by Meiwa Kasei Co., Ltd.
(Inorganic filler)
Spherical fused silica: “FB820” manufactured by Denki Kagaku Kogyo Co., Ltd. (average particle size: 15 μm, maximum particle size: 74 μm)
(Flexible agent 1)
-Flexifier of Formula 2: “BY16-849” manufactured by Toray Dow Corning (viscosity (25 ° C.): 1300 mm ² / s, specific gravity (25 ° C.): 0.98, amino equivalent: 600)
(Flexible agent 2)
Epoxy-modified silicone: “BY16-876” manufactured by Toray Dow Corning (viscosity (25 ° C.): 2500 mm ² / s, specific gravity (25 ° C.): 1.03, functional group (glycidyl) equivalent: 2800)
(Coupling agent)
Γ-glycidoxypropyltrimethoxysilane: “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.
(Release agent)
Carnauba wax: “F1-100” manufactured by Dainichi Chemical Co., Ltd.
(Coloring agent)
Carbon black: “40B” manufactured by Mitsubishi Chemical Corporation
(Curing accelerator)
・ Triphenylphosphine: “TPP” manufactured by Hokuko Chemical Co., Ltd.

By using each epoxy resin composition for semiconductor encapsulation prepared as described above and performing transfer molding under the following conditions, a PBGA package (sealing size: 29 mm × 29 mm × 35 mm × 35 mm × 0.5 mm substrate thickness) A thickness of 1.17 mm, a BT substrate, and a resist PSR4000) were produced.
-Mold temperature: 175 ° C
・ Injection pressure: 6.9 MPa
-Molding time: 90 seconds-Post-curing: 175 ° C x 6 hours

  In Comparative Example 1, the content of all epoxy resins is excessively increased, and the content of the flexible agent 1 (flexible agent of Formula 2) and the content of the inorganic filler are excessively decreased. Comparative Example 2 did not contain a flexible agent. Comparative Example 3 uses only the flexible agent 2 without using the flexible agent 1 (the flexible agent of Formula 2), and serves as a control for Example 3. In Comparative Example 4, the content of the flexible agent 1 (the flexible agent of Formula 2) is excessively increased. Comparative Example 5 uses only the epoxy resin 2 without using the epoxy resin 1 (epoxy resin of formula 1). In Comparative Example 6, the epoxy resin 1 (epoxy resin of the formula 1) was not used, but only the epoxy resin 3 was used, which is a control of Example 6. In Comparative Example 7, the inorganic filler content is excessively increased, and the total epoxy resin content is excessively decreased.

The following evaluation was performed about each epoxy resin composition for semiconductor sealing prepared as mentioned above.
(Spiral flow)
Using a spiral flow measurement mold according to ASTM D3123, the flow distance (cm) of the epoxy resin composition was measured and evaluated according to the following criteria. The target value is 140 cm or more.
◎: 180 cm or more ○: 140 cm or more to less than 180 cm Δ: 100 cm or more to less than 140 cm ×: less than 100 cm

The following evaluation was performed about each PBGA package produced as mentioned above.
(Warpage amount)
Using “Shadow Moire (PS200)” manufactured by AKROMETRIX, the amount of warpage (coplanarity) at room temperature of 25 ° C. was measured and evaluated according to the following criteria. The target value is 0 to less than 100 μm.
: 0 to less than 50 μm ○: 50 μm or more to less than 100 μm Δ: 100 μm or more to less than 150 μm ×: 150 μm or more

The results are shown in Table 1.

  As is apparent from the results of Table 1, the epoxy resin of formula 1 (epoxy resin 1) and the flexible agent of formula 2 (flexible agent 1) are used in combination, and the epoxy resin of formula 1 is used in all epoxy resins. 30-100% by mass, 50-100% by mass of the flexible agent of Formula 2 in the total flexible agent, 2-15% by mass of the epoxy resin in the total amount of the epoxy resin composition, Examples 1 to 7 containing 0.8 to 4.5% by mass in the total amount of the epoxy resin composition are excellent in both the fluidity of the epoxy resin composition and the warpage resistance of the package. The evaluation cleared the target value.

  On the other hand, at least one of (a) content of epoxy resin, (b) content of epoxy resin of formula 1, (c) content of flexible agent, and (d) content of flexible agent of formula 2 In Comparative Examples 1 to 7, which are outside the above preferred range, the evaluation of either the fluidity of the epoxy resin composition or the warpage resistance of the package did not clear the target value.

  Interestingly, in Comparative Example 3 which is a control of Example 3, only the flexible agent 1 (flexible agent of Formula 2) is replaced with the flexible agent 2, but the warpage resistance of the package is lowered. Not only was the amount of warpage (71 μm increased to 185 μm), the fluidity at the time of melting also decreased (spiral flow 190 cm decreased to 176 cm). Also, interestingly, Comparative Example 6 which is a control of Example 6 is that only the epoxy resin 1 (epoxy resin of Formula 1) and the epoxy resin 2 are replaced with the epoxy resin 3, but the flow at the time of melting Not only did the properties decrease (spiral flow 154 cm decreased to 148 cm), but also the warpage resistance of the package also decreased (the amount of warpage 38 μm increased to 154 μm). Thus, in the present invention, by using a combination of the epoxy resin of formula 1 (epoxy resin 1) and the flexible agent of formula 2 (flexible agent 1), the fluidity at the time of melting and the warpage resistance of the package. It can be seen that there is a synergistic effect that improves both.

  In addition, using the flexible agent 1 (flexible agent of Formula 2) and the flexible agent 2, the content in the total amount of the epoxy resin composition of the total flexible agent and the flexible agent 1 (possible of Formula 2) The content of all the flexing agents in the flexing agent was varied within the above-mentioned preferable range, and an epoxy resin composition was prepared in the same manner as described above, and a package was produced in the same manner as described above and evaluated. But the results were similar.

Claims (3)

An epoxy resin composition for semiconductor encapsulation containing an epoxy resin and a flexible agent,
2-15 mass% of epoxy resin is contained in the total amount of the epoxy resin composition,
Containing a flexible agent in the total amount of the epoxy resin composition in an amount of 0.8 to 4.5% by mass;
The said epoxy resin contains 30-100 mass% of bisphenol A type epoxy resins shown by following formula (1) in all the epoxy resins,
An epoxy resin composition for encapsulating a semiconductor, wherein the flexible agent contains 50 to 100% by mass of an amino-modified silicone represented by the following formula (2) in the total flexible agent.

  2. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the inorganic filler is contained in an amount of 70 to 90% by mass in the total amount of the epoxy resin composition.   A semiconductor device, wherein a semiconductor element mounted on a semiconductor element mounting substrate is sealed with the semiconductor sealing epoxy resin composition according to claim 1.