JP4622221B2 - Epoxy resin composition and semiconductor device - Google Patents

Description

  The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device, and in particular, a semiconductor element is mounted on one side of a printed wiring board or a metal lead frame, and only one side of the mounting surface side is made of resin. It is preferably used for a sealed area mounting type semiconductor device.

  In recent years, electronic devices have become smaller, lighter, and more functional, and as the integration of semiconductors has progressed year by year and the surface mounting of semiconductor devices has been promoted, new area-mounted semiconductor devices have been developed. It has been developed and is beginning to shift from conventional semiconductor devices. Typical area-mounting semiconductor devices are a ball grid array (hereinafter referred to as BGA) or a chip size package (hereinafter referred to as CSP) in pursuit of further miniaturization, but these are conventional quad flat packages (hereinafter referred to as CSP). The surface mount type semiconductor device represented by the small outline package (hereinafter referred to as SOP) has been developed to meet the demand for high pin count and high speed approaching the limit. The structure of the area mounting type semiconductor device includes a hard circuit board represented by bismaleimide triazine (hereinafter referred to as BT) resin / copper foil circuit board or a flexible circuit board represented by polyimide resin film / copper foil circuit board. A semiconductor element is mounted on one side, and only the element mounting surface, that is, one side of the substrate is molded and sealed with a resin composition or the like. In addition, solder balls are two-dimensionally formed in parallel on the surface opposite to the element mounting surface of the substrate, and are joined to a circuit substrate on which a semiconductor device is mounted. Further, as a substrate on which the element is mounted, a structure using a metal substrate such as a lead frame in addition to the organic circuit substrate has been devised.

  These area-mounted semiconductor devices have a single-side sealing configuration in which only the element mounting surface of the substrate is sealed with a resin composition and the solder ball forming surface side is not sealed. Very rarely, a metal substrate such as a lead frame may have a sealing resin layer of about several tens of μm on the solder ball forming surface, but a sealing resin of about several hundred μm to several mm on the device mounting surface. Since the layer is formed, it is substantially single-sided sealed. For this reason, in these semiconductor devices, due to the effects of thermal expansion / shrinkage mismatch between the organic substrate or metal substrate and the cured resin composition, or the effects of cure shrinkage during molding / curing of the resin composition, Warp is likely to occur. In addition, when solder bonding is performed on a circuit board on which these semiconductor devices are mounted, the moisture present in the semiconductor device due to moisture absorption of the cured product of the epoxy resin composition is applied to the semiconductor device due to stress caused by rapid vaporization at a high temperature. Cracks occur. Furthermore, in recent years, the use of lead-free solder having a higher melting point than ever is increasing due to environmental problems, and it is necessary to raise the mounting temperature by about 20 ° C. compared to the prior art by applying this solder. There is a problem in that the property is significantly lower than the current state. For these reasons, the demand for improving the reliability of semiconductor devices by increasing the level of the epoxy resin composition is acceleratingly increasing, and the lower viscosity of the resin and the higher filling of the inorganic filler are progressing.

  In order to maintain low viscosity and high fluidity at the time of molding, use of a resin having a low melt viscosity (see, for example, Patent Document 1) and silane coupling with an inorganic filler in order to increase the amount of the inorganic filler compounded A method of surface treatment with an agent is known (for example, see Patent Document 2). However, many of these satisfy only one of the various required characteristics, and no method has yet been found that can achieve both crack resistance and low viscosity during mounting, with low warpage and excellent crack resistance. Thus, there has been a demand for a further technique that satisfies the reliability by further increasing the blending amount of the inorganic filler, and does not impair the fluidity and curability.

JP-A-7-130919 (pages 2 to 5) JP-A-8-20673 (pages 2 to 4)

  The present invention relates to an epoxy resin composition suitable for area-mounting type semiconductor encapsulating having small warpage after molding or soldering treatment, and excellent fluidity and reliability after soldering treatment, and a semiconductor using the same A device is provided.

The present invention
[1] (A) an epoxy resin represented by the general formula (1), (B) a crystalline epoxy resin represented by the general formula (2), (C) a phenol resin represented by the general formula (3), (D) Curing accelerator, (E) Inorganic filler, and (F) The silane coupling agent represented by the general formula (4) is an essential component, and the weight ratio of the component (A) to the component (B) [ (A) / (B)] is 10/90 to 90/10, and (E) component is contained in an amount of 80 to 94% by weight based on the total epoxy resin composition. object,

(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)

(X is
R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms. m is an integer of 0-4. R2 is hydrogen or a C1-C4 alkyl group, and may be the same or different. )

(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)

(R1 is an organic group having 1 to 12 carbon atoms. R2, R3 and R4 are hydrocarbon groups having 1 to 12 carbon atoms. N is an integer of 1 to 3)

[2] A semiconductor device comprising a semiconductor element sealed with the epoxy resin composition according to the item [1],

[3] A semiconductor element is mounted on one side of the substrate, and is used for sealing only substantially one side of the substrate surface on which the semiconductor element is mounted, and is represented by (A) the general formula (1). (B) a crystalline epoxy resin represented by the general formula (2), (C) a phenol resin represented by the general formula (3), (D) a curing accelerator, (E) an inorganic filler, And (F) the silane coupling agent represented by the general formula (4) is an essential component, and the weight ratio [(A) / (B)] of the component (A) to the component (B) is 10/90 to 90. / 10, and the epoxy resin composition for area mounting type semiconductor encapsulation, comprising (E) component in an amount of 80 to 94% by weight based on the total epoxy resin composition,

(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)

(X is
R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms. m is an integer of 0-4. R2 is hydrogen or a C1-C4 alkyl group, and may be the same or different. )

(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)

(R1 is an organic group having 1 to 12 carbon atoms. R2, R3 and R4 are hydrocarbon groups having 1 to 12 carbon atoms. N is an integer of 1 to 3)

[4] A semiconductor element is mounted on one side of the substrate, and substantially only one side of the substrate side on which the semiconductor element is mounted is sealed with the epoxy resin composition described in the item [3]. Area mounting type semiconductor device, characterized by
It is.

  According to the present invention, it is possible to obtain an epoxy resin composition suitable for area-mounting type semiconductor encapsulation that has small warpage after molding or after soldering and has excellent fluidity and reliability after soldering. .

The present invention, (A) a biphenylene skeleton phenol aralkyl type epoxy resin having, (B) bisphenol type crystalline epoxy resin, (C) a biphenylene skeleton phenol aralkyl resin having, (D) a curing accelerator, (E ) An inorganic filler and (F) a silane coupling agent having a secondary amine are essential components, and the weight ratio [(A) / (B)] of the component (A) to the component (B) is 10/90 to 90/10, and (E) component contains 80 to 94% by weight based on the total epoxy resin composition, so warpage after molding or after soldering is small, and fluidity and reliability after soldering are excellent. In particular, an epoxy resin composition suitable for area mounting type semiconductor encapsulation can be obtained.
Hereinafter, each component will be described in detail.

The epoxy resin represented by the general formula (1) used in the present invention has a hydrophobic and rigid biphenylene skeleton between epoxy groups, and a cured product of an epoxy resin composition using the epoxy resin has a moisture absorption rate. It has a low elastic modulus in a high temperature range exceeding the glass transition temperature (hereinafter referred to as Tg), and is excellent in adhesion to a semiconductor element, an organic substrate, and a metal substrate. Moreover, it has the characteristic that heat resistance is high although a crosslinking density is low.
In the general formula (1), n is an average value and is a positive number of 1 to 5, preferably a positive number of 1 to 3. When n is less than the lower limit, the curability of the epoxy resin composition may be lowered, which is not preferable. If n exceeds the upper limit, the viscosity of the resin will increase, the fluidity of the epoxy resin composition will decrease, and it will become impossible to increase the filling of the inorganic filler to further reduce moisture absorption and warpage. This is not preferable because of its properties. The epoxy resin (A) represented by the general formula (1) includes, for example, a phenol biphenyl aralkyl type epoxy resin, but is not particularly limited as long as it has the structure of the formula (1).

(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)

  The crystalline epoxy resin represented by the general formula (2) used in the present invention is a crystalline solid at room temperature, but becomes a very low-viscosity liquid at a melting point or higher and can be highly filled with an inorganic filler. The epoxy resin composition using the has low warpage and excellent solder resistance. Examples of the crystalline epoxy resin represented by the general formula (2) include a bisphenol A type epoxy resin, but are not particularly limited as long as the structure is the formula (2).

(X is
R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms. m is an integer of 0-4. R2 is hydrogen or a C1-C4 alkyl group, and may be the same or different. )

  The weight ratio [(A) / (B)] of the blend of the epoxy resin (A) represented by the general formula (1) and the epoxy resin (B) represented by the general formula (2) can be adjusted by adjusting this. The best balance between high flow and low moisture absorption can be achieved. In order to bring out this effect, the weight ratio [(A) / (B)] of the blend of the epoxy resin (A) represented by the general formula (1) and the epoxy resin (B) represented by the general formula (2) Is 10/90 to 90/10, preferably 20/80 to 70/30, particularly preferably 30/70 to 50/50. If the weight ratio [(A) / (B)] is lower than the lower limit, the cured product of the epoxy resin composition cannot be reduced in moisture absorption, and solder crack resistance may be lowered, which is not preferable. On the other hand, if the weight ratio [(A) / (B)] exceeds the upper limit value, the fluidity is lowered, and it is impossible to increase the inorganic filler for further lower moisture absorption and lower warpage. This is not preferable.

  In the present invention, other epoxy resins may be used in combination as long as the characteristics of the epoxy resin represented by the general formula (1) and the crystalline epoxy resin represented by the general formula (2) are not impaired. . Examples of the epoxy resin that can be used in combination include monomers, oligomers, and polymers that have an epoxy group in the molecule. For example, phenol novolac type epoxy resin, orthocresol novolak type epoxy resin, naphthol novolak type epoxy resin, phenol aralkyl type epoxy resin having phenylene skeleton, naphthol aralkyl type epoxy resin (having phenylene skeleton, biphenyl skeleton, etc.), dicyclopentadiene Examples include modified phenol type epoxy resins, stilbene type epoxy resins, triphenol methane type epoxy resins, alkyl modified triphenol methane type epoxy resins, triazine nucleus-containing epoxy resins, etc. These may be used alone or in combination of two or more. May be used in combination. As the blending amount when other epoxy resins are used in combination, the total amount of the epoxy resin represented by the general formula (1) and the epoxy resin represented by the general formula (2) is 50 wt. %, More preferably 70% by weight or more is desirable. When the total amount of the epoxy resin represented by the general formula (1) and the epoxy resin represented by the general formula (2) is less than the lower limit value, solder crack resistance and fluidity may be decreased.

The phenol resin represented by the general formula (3) used in the present invention has a hydrophobic and rigid biphenylene skeleton between phenolic hydroxyl groups, and a cured product of an epoxy resin composition using the phenol resin has a low warpage. And has a low moisture absorption rate, a low elastic modulus in a high temperature range exceeding Tg, and excellent adhesion to semiconductor elements, organic substrates, and metal substrates. Moreover, it has the characteristic that heat resistance is high although a crosslinking density is low.
N in General formula (3) is an average value, and is a positive number of 1 to 5, preferably a positive number of 1 to 3. When n is less than the lower limit, the curability of the epoxy resin composition may be lowered. When n exceeds the upper limit, the resin viscosity increases, the fluidity of the epoxy resin composition decreases, and it becomes impossible to increase the inorganic filler for further reducing moisture absorption and warping. Therefore, it is not preferable. The phenol resin represented by the general formula (3) may be used alone or in combination of two or more. Examples of the phenol resin represented by the general formula (3) include a phenol biphenyl aralkyl resin, but are not particularly limited as long as the structure is represented by the formula (3).

(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)

  You may use together other phenol resin in the range which does not impair the characteristic by using the phenol resin shown by General formula (3) used by this invention. When used in combination, it is desirable to use monomers, oligomers, and polymers having a phenolic hydroxyl group in the molecule, and those having as low a viscosity as possible. For example, phenol novolak resins, cresol novolak resins, phenol aralkyl resins (phenylene skeletons) Naphthol aralkyl resin, triphenol methane resin, terpene-modified phenol resin, dicyclopentadiene-modified phenol resin, and the like. These may be used alone or in combination of two or more. In consideration of moisture resistance reliability as an epoxy resin composition for semiconductor encapsulation, it is preferable that Na ions and Cl ions, which are ionic impurities, be as small as possible. As the blending amount when other phenol resins are used in combination, the blending amount of the phenol resin represented by the general formula (3) is 50% by weight or more, more preferably 70% by weight or more with respect to all phenol resins. Is desirable. When the blending amount of the phenol resin represented by the general formula (3) is lower than the lower limit value, an increase in moisture absorption rate, a decrease in adhesion to a base material after soldering and a solder resistance, and a low warpage characteristic are also impaired. There is a fear.

  The equivalent ratio [(number of epoxy groups) / (number of phenolic hydroxyl groups)] of the number of epoxy groups of all epoxy resins and the number of phenolic hydroxyl groups of all phenol resins used in the present invention is preferably 0.5 to 2, particularly preferably. Is 0.7 to 1.5. Outside the above range, it is not preferable because there is a possibility that the curability of the epoxy resin composition is lowered, the glass transition temperature of the cured product is lowered, the moisture resistance reliability is lowered, or the like. When the epoxy resin represented by the general formula (1), the epoxy resin represented by the general formula (2), and the phenol resin represented by the general formula (3) are used in combination, the resistance to soldering after moisture absorption is improved. The highest effect is obtained in terms of cracking properties, warpage, and the like.

  The curing accelerator used in the present invention is one that can be a catalyst for the crosslinking reaction between the epoxy resin and the phenol resin. For example, diazabicyclo such as 1,8-diazabicyclo (5,4,0) undecene-7. Alkenes and their derivatives, amine compounds such as tributylamine and benzyldimethylamine, organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium / tetraphenylborate salts, imidazole compounds such as 2-methylimidazole, etc. It is not limited to. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular about the kind of inorganic filler used for this invention, What is generally used for the sealing material can be used. For example, fused silica, crystalline silica, secondary agglomerated silica, alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber, etc. may be mentioned, and these may be used alone or in combination of two or more. Good. In particular, fused silica is preferable. The fused silica can be used in either a crushed shape or a spherical shape, but it is more preferable to mainly use the spherical silica in order to increase the blending amount and suppress an increase in the melt viscosity of the epoxy resin composition. In order to further increase the blending amount of the spherical silica, it is desirable to adjust the particle size distribution of the spherical silica to be wider. The blending amount of the total inorganic filler needs to be 80 to 94% by weight in the total epoxy resin composition from the balance of moldability and reliability. If the value falls below the lower limit, the shrinkage at the time of molding hardening and the thermal shrinkage from the molding temperature to room temperature increase, so that warpage increases, and the moisture absorption rate increases, so solder crack resistance may decrease, which is not preferable. . Exceeding the upper limit is not preferable because the fluidity is lowered, and there is a risk of incomplete filling during molding or inconvenience such as deformation of the gold wire in the semiconductor device due to high viscosity.

  In the present invention, the silane coupling agent represented by the general formula (4) is essential. When the silane coupling agent represented by the general formula (4) is used, an effect that the viscosity of the epoxy resin composition is lowered and the fluidity is improved is obtained. The silane coupling agent represented by General formula (4) may be used individually by 1 type, or may use 2 or more types together. The blending amount is not particularly limited, but is preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight in the total epoxy resin composition. When the compounding quantity of the silane coupling agent represented by General formula (4) is less than a lower limit, there exists a possibility that the viscosity characteristic and flow characteristic which are expected may not be obtained. If the upper limit is exceeded, curability may be reduced. Further, other coupling agents such as γ-glycidoxypropyltrimethoxysilane may be used in combination as long as the effects of using the silane coupling agent represented by the general formula (4) are not impaired. Absent.

(R1 is an organic group having 1 to 12 carbon atoms. R2, R3 and R4 are hydrocarbon groups having 1 to 12 carbon atoms. N is an integer of 1 to 3)

  In addition to the components (A) to (F), the epoxy resin composition used in the present invention includes inorganic ion exchange such as brominated epoxy resins, antimony oxides, phosphorus compounds and other flame retardants, and bismuth oxide hydrates as necessary. Body, colorant such as carbon black, bengara, low stress components such as silicone oil and silicone rubber, natural wax, synthetic wax, mold release agents such as higher fatty acids and their metal salts or paraffin, and various additives such as antioxidants May be appropriately blended. Further, if necessary, the inorganic filler may be used after being pretreated with a coupling agent, an epoxy resin or a phenol resin. As a treatment method, a method of removing the solvent after mixing with a solvent, There is a method of adding to an inorganic filler and processing using a mixer.

The epoxy resin composition used in the present invention is obtained by mixing the components (A) to (F) and other additives at room temperature using a mixer, melt-kneading with a kneader such as an extruder such as a roll or kneader, and cooling. Obtained by post-grinding.
In order to seal an electronic component such as a semiconductor element and manufacture a semiconductor device using the epoxy resin composition of the present invention, it can be cured by a conventional molding method such as transfer molding, compression molding, injection molding, etc. Good. In particular, the epoxy resin composition of the present invention is optimal for area mounting type semiconductor devices.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The blending ratio is weight%.

Example 1
Biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd. NC3000, epoxy equivalent 274, softening point 58 ° C.) 2.60 parts by weight Bisphenol A type crystalline epoxy resin (Japan Epoxy Resin Co., Ltd. YL6810, epoxy equivalent 171, 2.60 parts by weight Biphenyl aralkyl type phenolic resin (Maywa Kasei Co., Ltd., MEH-7851SS, hydroxyl group equivalent 203, softening point 65 ° C.) 4.75 parts by weight Triphenylphosphine 0.35 parts by weight Spherical melting Silica (average particle size 30 μm) 89.00 parts by weight N-phenyl γ-aminopropyltrimethoxysilane 0.20 parts by weight Carbon black 0.30 parts by weight Carnauba wax 0.20 parts by weight at room temperature using a mixer, Using a biaxial kneader, mix so that the discharge temperature is 100 ° C. The mixture was kneaded under a kneader rotation speed of 120 rpm, cooled and pulverized to obtain an epoxy resin composition. The obtained epoxy resin composition was evaluated by the following methods. The results are shown in Table 1.

Evaluation method Spiral flow: Using a mold for spiral flow measurement according to EMMI-1-66, measurement was performed at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a curing time of 120 seconds. The unit is cm.
Package warpage amount: 352 pBGA (package size 32 mm × 32 mm × thickness 1.2 mm, semiconductor element size 10 mm × under conditions of mold temperature 180 ° C., injection pressure 9.8 MPa, curing time 90 seconds, using transfer molding machine 10 mm) and processed as post-cure at 175 ° C. for 2 hours. After cooling to room temperature, the displacement in the height direction was measured using a surface roughness meter in the diagonal direction from the gate of the package, and the largest value of the displacement difference was taken as the amount of package warpage before soldering. Then, after immersing in a solder bath at 260 ° C. for 10 seconds and cooling to room temperature, measure the displacement in the height direction using a surface roughness meter in the diagonal direction from the gate of the package. Was the amount of package warpage after soldering. The unit is μm.
Gold wire deformation rate: A 352 pBGA package formed by evaluating the amount of warpage of the package was observed with a soft X-ray fluoroscope, and the deformation rate of the gold wire was expressed as a ratio of (flow amount) / (gold wire length). Units%.
Resistance to solder stress: Ten pieces of the above-mentioned 352pBGA molded and treated as post-cure at 175 ° C. for 2 hours are humidified for 168 hours in an environment of 85 ° C. and 60% relative humidity, and then soldered at 260 ° C. It was immersed in the tank for 10 seconds. The presence or absence of internal cracks after the treatment was observed with an ultrasonic flaw detector, and the number of defective packages was counted. When the number of defective packages is n, n / 10 is displayed.

Examples 2-9, Comparative Examples 1-7
According to the composition of Table 1 and Table 2, an epoxy resin composition was produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The evaluation results are shown in Tables 1 and 2. The components used in other than Example 1 are shown below.
Orthocresol novolac epoxy resin (softening point 62 ° C, epoxy equivalent 210)
1-naphthol aralkyl type phenolic resin (softening point 87 ° C., hydroxyl group equivalent 210)
Phenol novolac resin (softening point 81 ° C, hydroxyl group equivalent 105)
γ-glycidoxypropyltrimethoxysilane

  The epoxy resin for encapsulating a semiconductor obtained by the present invention is excellent in fluidity, and a semiconductor device using the epoxy resin has small warpage after molding or after soldering and is excellent in reliability after soldering. Therefore, a semiconductor obtained by the present invention is a semiconductor device mounted on one side of a printed wiring board or a metal lead frame, and a so-called area mounting type semiconductor device in which only one side of the mounting side is resin-sealed. By applying an epoxy resin for sealing, the reliability can be improved.

Claims (6)

(A) an epoxy resin represented by general formula (1), (B) a crystalline epoxy resin represented by general formula (2), (C) a phenol resin represented by general formula (3), (D) A curing accelerator, (E) an inorganic filler, and (F) a silane coupling agent represented by the general formula (4) as essential components, the weight ratio of the component (A) to the component (B) [(A) / (B)] is 10/90 to 90/10,
(E) The epoxy resin composition for semiconductor sealing characterized by including 80 to 94 weight% of components with respect to all the epoxy resin compositions.
(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)
(X is
R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms. m is an integer of 0-4. R2 is hydrogen or a C1-C4 alkyl group, and may be the same or different. )
(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)
(R1 is an organic group having 1 to 12 carbon atoms. R2, R3 and R4 are hydrocarbon groups having 1 to 12 carbon atoms. N is an integer of 1 to 3) The weight ratio [(A) / (B)] between the component (A) and the component (B) is 30/70 to 50/50.
The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein:   A semiconductor device comprising a semiconductor element sealed with the epoxy resin composition according to claim 1. A semiconductor element is mounted on one side of a substrate, and used for sealing substantially only one side of the substrate surface on which the semiconductor element is mounted, and (A) an epoxy resin represented by the general formula (1) (B) a crystalline epoxy resin represented by the general formula (2), (C) a phenol resin represented by the general formula (3), (D) a curing accelerator, (E) an inorganic filler, and (F) ) The silane coupling agent represented by the general formula (4) is an essential component, and the weight ratio [(A) / (B)] of the component (A) to the component (B) is 10/90 to 90/10. And (E) component-containing epoxy resin composition for area-mounting semiconductor sealing, comprising 80 to 94% by weight based on the total epoxy resin composition.
(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)
(X is
R1 may be the same or different and is an alkyl group having 1 to 6 carbon atoms. m is an integer of 0-4. R2 is hydrogen or a C1-C4 alkyl group, and may be the same or different. )
(R1 and R2 are hydrogen or an alkyl group having 1 to 4 carbon atoms and may be the same or different. A is an integer of 0 to 3, b is an integer of 0 to 4. n is an average value, A positive number of 5)
(R1 is an organic group having 1 to 12 carbon atoms. R2, R3 and R4 are hydrocarbon groups having 1 to 12 carbon atoms. N is an integer of 1 to 3)   5. The epoxy resin for semiconductor encapsulation according to claim 4, wherein a weight ratio [(A) / (B)] of the component (A) to the component (B) is 30/70 to 50/50. Composition.   A semiconductor element is mounted on one side of the substrate, and substantially only one side of the substrate surface side on which the semiconductor element is mounted is sealed using the epoxy resin composition according to claim 4 or 5. Area-mounted semiconductor device.