JP2003261746A - Resin composition for sealing and sealed electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing resin composition having excellent soldering heat-resistance and high flame retardance and provide a sealed electronic device produced by using the composition. <P>SOLUTION: The resin composition for sealing contains (A) an epoxy resin containing a component of general formula (1) ((n) is zero or an integer of ≥1), (B) a phenolic resin curing agent, (C) a polysiloxane, (D) an amino-type silane coupling agent and (E) an inorganic filler. The invention further provides a sealed electronic device produced by using the composition. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sealing resin composition used as a sealing material for electronic components such as semiconductors, and an electronic component sealing device using the same.

[0002]

2. Description of the Related Art Conventionally, it has been widely practiced to seal electronic parts such as semiconductors with a thermosetting resin. Such sealing resin material is based on epoxy resin,
A composition in which a curing agent, a curing accelerator, an inorganic filler such as silica powder, a pigment, and the like are added to this is generally used in terms of reliability, moldability, and price.

By the way, in recent years, in the field of semiconductor integrated circuits, along with the high integration of chips, the chip size has become larger and the number of poles has increased. On the other hand, the package design is also a conventional pin insertion type DIP (Dual-In Line). Packag
e), surface mount type SOP (Small Outline Packag)
e), QFP (Quad Flat Package), SOJ (Small Ou)
tline J-lead Package), TSOP (Thin SOP),
LQFP (Large QFP), TQFP (Thin QFP)
Is changing.

With such a change in the mounting method, cracks occur in the sealing resin portion of the package during mounting (solder process), or peeling occurs between the chip and the sealing resin or between the substrate and the sealing resin. The problem is occurring. This is because in the surface mount type package, the entire package is directly immersed in a high temperature (230 to 270 ℃) solder bath during mounting, so the sealing resin material has more severe solder heat resistance than the pin insertion type. Is required. That is, the conventional epoxy resin composition was slightly insufficient in solder heat resistance to be applied to the surface mount type package.

Therefore, there is a demand for the development of an epoxy resin composition having excellent solder heat resistance which does not cause cracks or peeling as described above even when applied to a surface mount type package.

On the other hand, this type of sealing resin material is required to have flame retardancy according to the UL standard from the viewpoint of safety.

Conventionally, in an epoxy resin composition, it is common to use a halogen-based flame retardant containing a halogen element such as chlorine or bromine and an antimony compound (usually antimony trioxide) for flame retardation. However, these halogen-based flame retardants and antimony compounds have a problem of reducing the reliability of electronic parts. In addition, recently these environmental impacts have begun to be pointed out.

For this reason, development of flame retardant technology not containing a halogen flame retardant and an antimony compound, such as the combined use of a phosphorus flame retardant and a metal hydrate, is underway. However, conventional halogen flame retardants and antimony are not used. There is a problem that long-term moisture resistance reliability is reduced as compared with the combined use of compounds.

[0009]

As described above, there is a demand for an epoxy resin composition having excellent soldering heat resistance as the mounting method is changed from the pin insertion type to the surface mounting type. Further, in such an epoxy resin composition, development of a highly reliable flame retardant technique which is an alternative to the combined use of a halogen-based flame retardant and an antimony compound has been demanded in consideration of the environment.

The present invention has been made in view of such conventional circumstances, and a sealing resin having excellent solder heat resistance which does not cause cracks or peeling even when applied to a surface mount type package. An object is to provide a composition and an electronic component sealing device using the same. Further, the present invention provides a resin composition for encapsulation, which is excellent in flame retardancy, retains good moisture resistance for a long period of time, and has no environmental problem, and an electronic component encapsulation device using the same. The purpose is to do.

[0011]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that an epoxy resin having a specific structure is used in combination with an amino silane coupling agent and a polysiloxane. According to the present invention, the solder heat resistance of the epoxy resin composition can be improved, and the epoxy resin composition can be provided with excellent flame retardancy without using a flame retardant. Is.

That is, the encapsulating resin composition of the present invention is
(A) The following general formula (1)

[Chemical 4] (However, in the formula, n represents 0 or an integer of 1 or more), an epoxy resin containing a component, (B) a phenol resin curing agent, (C) polysiloxane, (D) an amino silane coupling agent, and (E) is characterized by containing an inorganic filler.

Here, the polysiloxane of the component (C) is
It may contain an amino-modified polysiloxane having an amine equivalent weight of 500 to 8000.

Further, the phenol resin curing agent of the component (B) is represented by the following general formula (2)

[Chemical 5] (However, in the formula, n represents 0 or an integer of 1 or more).

Further, the epoxy resin as the component (A) is represented by the following general formula (3)

[Chemical 6] (However, in the formula, R1 to R4 each represent a hydrogen atom or a methyl group).

Further, the content of the inorganic filler of the component (D) is
It may be 80 to 92% by weight.

In the encapsulating resin composition having the above structure,
By using an amino-based silane coupling agent and polysiloxane in combination with an epoxy resin having a specific structure,
It has excellent solder heat resistance that can be sufficiently applied to surface mount type packages, and also has excellent flame retardancy.

The encapsulating resin composition of the present invention is characterized in that the encapsulating resin composition of the above invention contains substantially no flame retardant.

In such a sealing resin composition,
Since the flame retardant is not substantially contained, it is possible to reduce the deterioration of the moisture resistance reliability and the influence on the environment due to the use of the flame retardant.

The electronic component sealing device of the present invention is characterized in that the electronic component is sealed with the cured product of the sealing resin composition of the present invention.

In the electronic component sealing device of the present invention, since the electronic component is sealed by the cured product of the sealing resin composition having excellent solder heat resistance and flame retardancy, any mounting is possible. Even with this method, highly reliable mounting is possible, and flame resistance is also provided.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The encapsulating resin composition of the present invention comprises (A) an epoxy resin containing a component represented by the following general formula (1):
(B) Phenolic resin curing agent, (C) Polysiloxane,
It contains (D) an amino-based silane coupling agent and (E) an inorganic filler as essential components.

[Chemical 7] (However, in the formula, n represents 0 or an integer of 1 or more)

As the epoxy resin represented by the general formula (1), those having an epoxy equivalent of 200 to 350 are preferable, and those having an epoxy equivalent of 250 to 320 are more preferable. Further, those having a softening temperature in the range of 40 to 100 ° C are preferable, and those having a softening temperature in the range of 50 to 75 ° C are more preferable. Further, it is preferable that the melt viscosity (150 ° C.) measured by an ICI viscometer (cone & plate type) is in the range of 0.01 to 0.3 Pa · s, and the melt viscosity (150 ° C.) is 0.01 to 0.15 Pa · s.
Those in the s range are preferred. Specifically, NC-3000P (trade name; epoxy equivalent 273, softening temperature 57 ° C, melt viscosity (150 ° C) 0.07 Pa · s) manufactured by Nippon Kayaku Co., Ltd., NC-30
00S (trade name; epoxy equivalent 282, softening temperature 59 ° C., melt viscosity (150 ° C.) 0.09 Pa · s) and the like are preferably used.

In the present invention, other epoxy resins can be used in combination, if necessary. Examples of the epoxy resin used in combination include phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, triphenol methane type epoxy resin, heterocyclic type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin. , Stilbene type epoxy resin, condensed ring aromatic hydrocarbon modified epoxy resin and the like. These may be used alone or in combination of two or more.

In the present invention, the biphenyl type epoxy resin represented by the following general formula (3) is preferable, and the epoxy equivalent thereof is particularly in the range of 140 to 220, preferably in the range of 150 to 200, Softening temperature is 80-180 ℃
, Preferably in the range of 95 to 170 ° C., or in the range of 0.001 to 0.05 Pa · s in melt viscosity (150 ° C.) measured by an ICI viscometer (cone & plate type), preferably Is preferably in the range of 0.005 to 0.05 Pa · s. Specifically, YX-40 manufactured by Japan Epoxy Co., Ltd.
00H (trade name; epoxy equivalent 193, melting point 108 ° C., melt viscosity (150 ° C.) 0.02 Pa · s) and the like are preferably used.

[Chemical 8] (However, in the formula, R1 to R4 represent a hydrogen atom or a methyl group)

When such an epoxy resin is used in combination,
The blending amount thereof is preferably in the range of 5 to 50% by weight based on the total weight of the epoxy resin. More preferably, it is in the range of 10 to 40% by weight based on the total weight of the epoxy resin.

The (B) phenolic resin curing agent is (A)
As long as it has two or more phenolic hydroxyl groups capable of reacting with the epoxy group of the epoxy resin in the molecule, it is used without particular limitation, and examples thereof include phenol novolac resin, cresol novolac resin, and dicyclopentadiene-modified phenol. Resin, para-xylene-modified phenol resin, condensate of phenol and benzaldehyde, naphthylaldehyde, etc., triphenolmethane compound,
Examples thereof include polyfunctional phenolic resins. These are 1
The seeds may be used alone or in combination of two or more.

In the present invention, the phenol resin represented by the following general formula (2) is preferable, and the phenolic hydroxyl group equivalent is 170 to 230, preferably 190 to 2
Those having a range of 20 or having a softening temperature of 40 to 100 ° C., preferably 55 to 90 ° C. are preferable. Specifically, MEH-7851H manufactured by Meiwa Kasei Co. (hydroxyl equivalent 19
9, softening temperature 82 ℃, MEH-7851M (hydroxyl equivalent 1
99, softening temperature 76 ° C.), MEH-7851SS (hydroxyl group equivalent 198, softening temperature 66 ° C.) (all of which are trade names) are preferably used.

[Chemical 9]

When the other phenol resin is used in combination with the phenol resin represented by the general formula (2), a para-xylene-modified phenol resin is preferable. Specific examples of the para-xylene-modified phenol resin include XL-225-3L (hydroxyl group equivalent 174, softening temperature 70 ° C.), XLC-LL (hydroxyl group equivalent 17) manufactured by Mitsui Chemicals, Inc.
6, softening temperature 79 ° C), XLC-3L (hydroxyl group equivalent 172, softening temperature 72 ° C), XLC-4L (hydroxyl group equivalent 167, softening temperature 63 ° C), MEH-7800M manufactured by Meiwa Kasei (hydroxyl equivalent 175, softening) Temperature 80 ℃), MEH-7800S (hydroxyl group equivalent 175, softening temperature 75 ℃), MEH-7800SS
(Hydroxyl equivalent 175, softening temperature 65 ° C), HE100C-10 manufactured by Sumikin Chemical Co. (hydroxyl equivalent 168, softening temperature 68)
℃), HE100C-15 (hydroxyl group equivalent 170, softening temperature 7
5 ° C), HE100C-30 (hydroxyl group equivalent 170, softening temperature
80 ° C.) (these are all trade names) and the like.

The mixing ratio of the epoxy resin (A) and the phenol resin curing agent (B) is such that the phenolic hydroxyl group contained in the phenol resin curing agent (B) / the epoxy group contained in the epoxy resin (A) (equivalent ratio Is preferably in the range of 0.5 to 1.0, and more preferably in the range of 0.6 to 1.0.
When the equivalent ratio of the phenolic hydroxyl group of the phenol resin curing agent to the epoxy group of the epoxy resin is less than 0.5, moldability, curability and mold releasability decrease, and when it exceeds 1.0, reflow resistance decreases.

The polysiloxane (C) is preferably an amino-modified polysiloxane, or a combination of an amino-modified polysiloxane and one or more kinds of other modified polysiloxanes. Examples of the modified polysiloxane other than the amino-modified polysiloxane include epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, phenol-modified polysiloxane, mercapto-modified polysiloxane, methacryl-modified polysiloxane, and polyether-modified polysiloxane. , Alkyl-modified polysiloxane, and the like. Modified polysiloxanes other than such amino-modified polysiloxanes include
It is preferably 30% by weight or less based on the total weight of the polysiloxane. More preferably, it is in the range of 20% by weight or less based on the total weight of polysiloxane.

The amino-modified polysiloxane is preferably a siloxane skeleton having an amino group introduced at one end, both ends or side chains, preferably both ends or side chains, and more preferably both ends. Those in which the side chain is substituted with a phenyl group are more preferable because the dispersibility is improved. The amine equivalent of this amino-modified polysiloxane is preferably 500 to 8000, and more preferably 1500 to 6500. If the amine equivalent is less than 500, moldability and mold releasability will be insufficient, and conversely, if the amine equivalent exceeds 8,000, the adhesiveness will decrease.

The compounding amount of this polysiloxane (C) is
The range of 0.01 to 1.0% by weight of the total composition is preferred, 0.05
~ 0.8 wt% is more preferable, 0.1 ~ 0.5
It is even more preferable to be in the range of% by weight. Compounding amount
If it is less than 0.01% by weight, the effect of improving or improving the adhesiveness is small, and if the compounding amount exceeds 1.0% by weight, moldability and releasability are deteriorated.

Examples of the amino-based silane coupling agent (D) include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and N-β- (aminoethyl) -γ-aminopropylmethyldimethoxy. Examples thereof include silane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-ureidopropyltriethoxysilane. These can be used alone or in combination of two or more. Of these, N-phenyl-γ-aminopropyltrimethoxysilane and γ-ureidopropyltriethoxysilane are preferable in the present invention.

In the present invention, a silane coupling agent other than the amino silane coupling agent may be used in combination, if necessary. As the silane coupling agent used in combination, γ- (methacrylopropyl) trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy Examples thereof include propylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, imidazolesilane and vinyltriacetoxysilane. These may be used alone or in combination of two or more. When a silane coupling agent other than such an amino silane coupling agent is used in combination, the compounding amount thereof is preferably in the range of 50% by weight or less based on the total weight of the silane coupling agent. A more preferred range is 25% by weight or less based on the total weight of the silane coupling agent.

The inorganic filler (E) is added for the purpose of improving and improving the properties such as the thermal expansion coefficient, thermal conductivity, water absorption and elastic modulus of the cured product. Fused silica, crystalline silica Powder of alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, etc.
Examples thereof include spherical beads, single crystal fibers, glass fibers and the like. These can be used alone or in combination of two or more. In the present invention, among these, powdery ones having a maximum particle size of 100 μm or less and an average particle size of 1 to 50 μm are suitable, and a maximum particle size of 75 μm or less and an average particle size of 5 to 25 μm. And more preferable. If the maximum particle size exceeds 100 μm or the average particle size exceeds 50 μm, it becomes difficult not only to fill the narrow portion but also the dispersibility decreases and the molded product becomes non-uniform. The average particle size is 1
If it is less than μm, the viscosity increases and the moldability becomes poor. Further, it is more preferable that the shape of these powders be as spherical as possible from the viewpoint of fluidity, moldability, mold abrasion resistance, and the like. Fused silica is suitable for applications requiring low thermal expansion, and crystalline silica or alumina is suitable for applications requiring high thermal conductivity.

The content of the inorganic filler (E) is preferably 80 to 92% by weight, and 82 to 90% by weight based on the total weight of the composition.
Is more preferable, and the range of 83 to 88% by weight is even more preferable. If the blending amount is less than 80% by weight, the effect of improving and improving the properties such as the above-mentioned thermal expansion coefficient is small. On the contrary, if the blending amount exceeds 92% by weight, the fluidity of the composition is lowered and the moldability is deteriorated. It becomes defective and practically difficult.

In the encapsulating resin composition of the present invention, in addition to the above-mentioned components, a curing accelerator, carbon black, and Add colorants such as cobalt blue, surface treatment agents such as alkyl titanates, mold release agents such as synthetic wax and natural wax, halogen trap agents, stress reducing agents such as silicone oil and silicone rubber, etc. You can

As the curing accelerator, 1,8-diazabicyclo
[5,4,0] Undecene-7 (DBU), triethylenediamine, benzyldimethylamine, triethanolamine,
Tertiary amines such as dimethylaminoethanol, tris (dimethylaminomethyl) phenol, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, tributylphosphine, diphenylphosphine, triphenylphosphine And other organic phosphines, tetraphenylphosphonium tetraphenylborate, tetraphenylboron salts such as triphenylphosphine tetraphenylborate, and the like. These can be used alone or in combination of two or more.

In preparing the encapsulating resin composition of the present invention, the above components are thoroughly mixed (dry blended) with a mixer or the like, then melt-kneaded with a hot roll or kneader, and cooled and then pulverized. You can do this.

The electronic component sealing device of the present invention can be manufactured by sealing various electronic components using the above sealing resin composition. Examples of electronic components for sealing include integrated circuits, large-scale integrated circuits, transistors, thyristors, and diodes. As a sealing method, a low-pressure transfer method is generally used, but sealing by injection molding, compression molding, casting or the like is also possible. After encapsulating with the encapsulating resin composition, it is heated and cured, and finally an electronic component encapsulating device encapsulated by the cured product is obtained. The heating temperature for post-curing is preferably 150 ° C. or higher.

[0042]

EXAMPLES Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

Examples 1 to 18 and Comparative Examples 1 to 4 Epoxy resin, phenol resin curing agent, polysiloxane, amino silane coupling agent, and
Inorganic filler with a maximum particle size of 75 μm, average particle size of 16 μm, specific surface area of 4.6 m ² / g fused spherical silica, γ-as a curing accelerator
Using glycidoxypropyltrimethoxysilane, carnauba wax as a release agent, and carbon black as a colorant, resin compositions for encapsulation were produced by a conventional method at the compounding ratios shown in Tables 1 and 2. That is, each component was mixed at room temperature, heated and kneaded at a resin temperature of 70 to 90 ° C., cooled, and then pulverized to an appropriate size to produce a sealing resin composition through a screen having a diameter of 3 mm. Epoxy resin A: Epoxy resin represented by the general formula (1)
(Nippon Kayaku Co., Ltd., trade name NC-3000P, epoxy equivalent 273) Epoxy resin B: epoxy resin represented by the general formula (3)
(Japan Epoxy Resin Co., Ltd. product name YX-4000H, epoxy equivalent 193) Phenolic resin: Phenolic resin represented by the general formula (2) (Meiwa Chemical Co., Ltd. product name MEH-7851S, hydroxyl equivalent 198) Polysiloxane A: both ends Is modified with an amine (amine equivalent 5700) Polysiloxane B: Polydimethylsiloxane with amine modified at both ends and phenyl groups introduced into the side chain (amine equivalent 2200) Polysiloxane C: Side chain is an amine Polydimethylsiloxane modified with (amine equivalent 3800) Polysiloxane D: Polydimethylsiloxane modified with amines at both ends (amine equivalent 450) Polysiloxane E: Polydimethylsiloxane modified with side chains with amine (amine equivalent 11000) Silane coupling agent A: γ-aminopropyltriethoxysilane silane coupling B: N-phenyl-γ-aminopropyltrimethoxysilane silane coupling agent C: γ-ureidopropyltriethoxysilane silane coupling agent D: γ-glycidoxypropyltrimethoxysilane In each of the above Examples and Comparative Examples. Various characteristics of the obtained sealing resin composition were evaluated by the methods described below.

[Water Absorption] The sealing resin composition was heated at 175 ° C. and 90%.
Transfer molding under conditions of 2 seconds, then post-curing at 175 ° C for 8 hours to obtain a disk-shaped cured product with a diameter of 50 mm and a thickness of 3 mm, which is placed in saturated steam at 127 ° C and 2.5 atm for 24 hours. Upon standing, the increased weight was determined.

[Burcol hardness] 17 resin compositions for sealing
Transfer molding was performed into a disk shape having a diameter of 50 mm and a thickness of 3 mm under the condition of 5 ° C. for 90 seconds, and the hardness of the molded product was measured by a Barcol hardness meter immediately after the mold was opened.

[Spiral flow] 1 according to EMMI-I-66
The measurement was performed at 75 ° C. for 120 seconds.

[Moisture resistance reliability] Using a sealing resin composition, a silicon chip having two aluminum wirings
2 Adhesion to an alloy frame, transfer molding at 175 ° C for 90 seconds and post-curing at 175 ° C for 8 hours, then the resulting molded product was tested for humidity resistance (PCT) in saturated steam at 127 ° C and 2.5 atmospheres. ) Was performed and the time until 50% disconnection failure due to aluminum corrosion occurred was measured, and the failure occurrence rate after 100 hours, 200 hours, 400 hours and 1000 hours was examined.

[Reflow resistance] Using the encapsulating resin composition, transfer molding was carried out at 175 ° C. for 90 seconds and at 175 ° C. for 8 seconds.
QFP package (14mm × 14mm × 1.
4mm, chip size: 6.0mm x 6.0mm, copper frame) is made, and 85 ℃, 85% RH, 48, 72, 96,
After performing moisture absorption treatment for 168 hours respectively, IR at 260 ° C
After performing reflow three times and cooling, the presence or absence of peeling (peeling area 10% or more) was observed by an ultrasonic flaw detector, and the occurrence rate was examined.

[Amount of package warp] Transfer molding at 175 ° C. for 2 minutes and 175 ° C. using the resin composition for sealing
BGA package (30mm x 30mm after post-curing for 8 hours)
X 1.2 mm, chip size: 10 mm x 10 mm) was prepared and measured with a non-contact laser measuring machine.

[Flame-retardant] A sealing resin composition was heated at 175 ° C. for 90
120 mm x 12 mm x 0.8 mm and 120 mm x 1 after transfer molding under conditions of 1 second and then post-curing at 175 ° C for 8 hours.
A 2 mm x 3.2 mm cured product was obtained and a combustion test based on the UL-94 flame resistance test standard was performed.

The results are shown in Tables 3 and 4.

[0052]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[0053]

As described above, according to the present invention,
It is possible to obtain a sealing resin composition having excellent solder heat resistance that does not cause cracking or peeling even when applied to a surface mount type package, and an electronic component sealing device using the same.

Further, according to the present invention, a resin composition for encapsulation which is excellent in flame retardancy, retains good moisture resistance for a long period of time, and has no environmental problem, and an electronic component encapsulation using the same. A stop device can be obtained.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 83/04 C08L 83/04 H01L 23/29 H01L 23/30 R 23/31 F term (reference) 4J002 CC043 CC053 CC063 CD052 CD062 CD071 CD072 CE003 CP054 CP094 CP104 CP164 CP184 DE117 DE137 DE147 DE237 DJ007 DJ017 DJ047 DK007 EX076 FD017 FD150 FD204 FD206 GQ05 4J036 AA05 AD04 AD07 AD12 AE05 DA02 DC06 DC12 DC13 DC41 DC46 DD07 FA03 FA05 FA06 FB06 FB07 GA04 GA23 JA07 4M109 AA01 CA21 EB06 EB18

Claims (7)

[Claims] 1. (A) The following general formula (1): (However, in the formula, n represents 0 or an integer of 1 or more), an epoxy resin containing a component, (B) a phenol resin curing agent, (C) polysiloxane, (D) an amino silane coupling agent, and (E) An encapsulating resin composition containing an inorganic filler. 2. The encapsulating resin composition according to claim 1, wherein the polysiloxane as the component (C) contains an amino-modified polysiloxane having an amine equivalent of 500 to 8000. 3. A phenol resin curing agent as component (B),
The following general formula (2): (However, in the formula, n represents 0 or an integer of 1 or more). The encapsulating resin composition according to claim 1, comprising a component represented by the formula. 4. The epoxy resin of component (A) has the following general formula (3): The resin composition for encapsulation according to claim 1, further comprising a component represented by the formula (wherein R 1 to R 4 represent a hydrogen atom or a methyl group). 5. The content of the inorganic filler as the component (E) is 80 to
The encapsulating resin composition according to any one of claims 1 to 4, wherein the encapsulating resin composition is 92% by weight. 6. The epoxy resin composition according to claim 1, which is substantially free of a flame retardant. 7. An electronic component encapsulating device, wherein an electronic component is encapsulated with the cured product of the encapsulating resin composition according to any one of claims 1 to 6.