JPH10182949A - Epoxy resin composition and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition excellent in stability during its storage. SOLUTION: This epoxy resin composition comprises (A) an epoxy resin, (B) a phenolic resin, (C) a filler composed of at least one kind of acidic metal element compound selected from the group consisting of aluminum oxide, silicon dioxide, silicon carbide, trisilicon tetranitride, boron nitride and boron carbide and satisfying the condition (α) described below: (α) ΔH/mC is 400-1,500kcal (ΔH is the heat of dissociation of the metal element oxide; (m) is the number of cations; C is the number of coordination to oxygen atom), and (D) curing promoter-contg. microcapsules having core/shell structure with its curing promoter core portion coated with polyurea shell portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition having excellent storage stability and a highly reliable semiconductor device using the same.

[0002]

2. Description of the Related Art Generally, semiconductor devices such as transistors, ICs, and LSIs are encapsulated with an epoxy resin composition to form semiconductor devices. This type of epoxy resin composition usually contains various curing agents, curing accelerators, and inorganic fillers in addition to the epoxy resin.

[0003]

However, when the above-mentioned inorganic filler is blended with other components and kneaded to produce an epoxy resin composition, a reaction occurs in the system of the composition and the reaction during storage causes There is a problem that storage stability is poor. When this is used as a semiconductor encapsulating material, there is a problem that it is difficult to obtain a package with uniform resin encapsulation due to unstable fluidity.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an epoxy resin composition having excellent storage stability during storage and a highly reliable semiconductor device obtained by using the same. And

[0005]

In order to achieve the above object, the present invention provides an epoxy resin containing the following components (A) and (B) and containing the following components (C) and (D): A first subject of the present invention is a composition, and a second subject of the present invention is a semiconductor device in which a semiconductor element is sealed using the epoxy resin composition. (A) Epoxy resin. (B) a phenolic resin. (C) A filler comprising an acidic metal element compound having a metal element satisfying the following condition (α). (Α) A value (ΔH / mC) obtained by dividing the heat of dissociation ΔH of the oxide of the metal element by the product of the number m of cations and the coordination number C with respect to oxygen atoms (ΔH / mC) is 400 to 1500 kcal. (D) A hardening accelerator-containing microcapsule having a core / shell structure in which a core made of a hardening accelerator is covered with a shell made of a thermoplastic resin.

[0006] That is, the present inventors have paid attention to the reaction that occurs in the production process of the epoxy resin composition, and have intensively studied to pursue the cause of the reaction. In the course of the study, when various inorganic fillers were kneaded with a filler composed of an acidic metal element compound having a metal element and a curing accelerator, the metal element in the filler and the curing accelerator reacted to cure. It was found that the reaction was delayed. And as a result of continuing research based on this finding, a filler (C component) composed of an acidic metal element compound having the above specific metal element
And a hardening accelerator-containing microcapsule (D component) having a core / shell structure in which a core made of a hardening accelerator is covered with a shell made of a thermoplastic resin, the metal element in the filler It has been found that the reaction between the epoxy resin composition and the curing accelerator can be suppressed and an epoxy resin composition having excellent curing stability even after storage can be obtained, and the present invention has been achieved.

[0007] The acidic metal element compound in the filler (component C) is at least one filler selected from the group consisting of aluminum oxide, silicon dioxide, silicon carbide, trisilicon tetranitride, boron nitride and boron carbide. It has been found that the use of a compound can effectively suppress the reaction between the metal element in the filler and the curing accelerator.

[0008]

Next, embodiments of the present invention will be described in detail.

The epoxy resin composition of the present invention comprises, together with an epoxy resin (A component) and a phenol resin (B component),
Further, it is obtained by using a specific filler (C component) and a microcapsule containing a curing accelerator (D component),
Usually, it is in the form of a powder or a tablet obtained by compressing it.

The epoxy resin (component A) is not particularly limited. For example, cresol novolak epoxy resin, phenol novolak epoxy resin, novolak bisphenol A epoxy resin, bisphenol A epoxy resin, dicyclopentadiene Epoxy resin and the like. Above all, it is preferable to use a biphenyl type epoxy resin represented by the following general formula (1) from the viewpoint of low viscosity and low hygroscopicity.

[0011]

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In the general formula (1), those having a hydrogen atom or a methyl group as R _{1 to} R ₄ are more preferable from the viewpoint of low hygroscopicity and reactivity.

The biphenyl type epoxy resin represented by the general formula (1) includes an epoxy equivalent of 160 to 350,
Those having a softening point of 50 to 150 ° C are preferred.

The phenol resin (component B) used together with the epoxy resin (component A) is not particularly limited, and various phenol resins which function as a curing agent for the epoxy resin are conventionally used. Among them, a phenol aralkyl resin is preferably used, and specifically, a phenol aralkyl resin represented by the following general formula (2) is particularly preferably used.

[0015]

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In the general formula (2), the number of repetitions n
Is preferably in the range of 0 to 40, particularly preferably n =
It is in the range of 0-30.

The phenol aralkyl resin represented by the general formula (2) has a hydroxyl equivalent of 150 to 220 and a softening point of 4
The temperature is preferably from 0 to 110 ° C, more preferably 1 hydroxyl equivalent.
50-200, softening point 50-90 ° C.

The mixing ratio of the epoxy resin (component A) and the phenol resin (component B) is such that the hydroxyl group in the phenol resin is 0.8 to 1.2 equivalents per equivalent of epoxy group in the epoxy resin component. It is preferable to mix them. More preferred is 0.9 to 1.1 equivalents.

As the specific filler (component C) used together with the above-mentioned components A and B, those composed of an acidic metal element compound having a specific metal element are used.
The specific metal element is obtained by dividing the heat of dissociation ΔH (kcal) of the oxide of the metal element by the product of the number m of cations and the coordination number C to the oxygen atom (O ²⁻ ) ( ΔH /
mC) must be 400 to 1500 kcal. That is, in the above metal element, ΔH / mC
Is less than 400 kcal, the acidity is originally low, so that the difference from the case where the microcapsules (D component) containing the curing accelerator are used is not remarkable. Conversely, if the value of ΔH / mC exceeds 1500 kcal, Although the reason is not clear, even if a curing accelerator-containing microcapsule (component D) is used, the delay of the curing reaction is increased. Probably, these acidic metal element compounds coordinate curing accelerators having unpaired electrons, such as nitrogen and phosphorus, and cause curing retardation.

And, it has such a specific metal element.
Examples of the acidic metal element compound include iron oxide (Fe
_TwoO_Three, ΔH / mC = 456 kcal), aluminum oxide
Um (Al_TwoO_Three, ΔH / mC = 456 kcal), acid
Chrome (Cr)_TwoO_Three, ΔH / mC = 456 kca
l), boron oxide (B_TwoO_Three, ΔH / mC = 754 kc
al), silicon dioxide (SiO_Two, ΔH / mC = 777
kcal), phosphorus oxide (P _TwoO_Three, ΔH / mC = 121
4 kcal), silicon carbide (SiC, ΔH / mC = 76)
0 kcal), trisilicon tetranitride (Si_ThreeN_Four, ΔH / m
C = 770 kcal), boron nitride (BN, ΔH / mC)
= 750 kcal), boron carbide (B_FourC, ΔH / mC
= 745 kcal). These alone
Or two or more kinds are used in combination. Of these,
The point that the curing reaction with the curing accelerator can be effectively suppressed
And Al_TwoO_Three, SiO_Two, SiC, Si_ThreeN_Four, B
N, B_FourIt is particularly preferred to use C. Like this charcoal
The oxides and nitrides are acidic because the oxide layer
It seems to be formed.

The average particle size of the above-mentioned specific filler (component C) is preferably 0.5 to 40 μm, particularly preferably 2 to 40 μm.
30 μm. When the filler (component C) is used, it is usual to use a mixture having different average particle sizes. In this case, it is preferable to use a mixture of different types of fillers (component C).

The amount of the specific filler (component C) is as follows:
It is preferably set to 70 to 95% by weight of the entire epoxy resin composition, and particularly preferably 85 to 90% by weight.

The microcapsules containing a curing accelerator (component D) used together with the above components A to C have a core / shell structure in which a core made of a curing accelerator is covered with a shell made of a thermoplastic resin. It is a capsule.

The hardening accelerator included in the core is not particularly limited, and a conventionally known hardening accelerator can be used. In this case, those having a liquid state at normal temperature are preferred from the viewpoint of workability in preparing the microcapsules and characteristics of the obtained microcapsules. The term “liquid at room temperature” includes not only the case where the properties of the curing accelerator itself are liquid at room temperature, but also those which are solid at room temperature but are dissolved or dispersed in any organic solvent or the like to form a liquid.

Examples of the curing accelerator include amine, imidazole, phosphorus, boron, and phosphorus-boron curing accelerators. Specifically, alkyl-substituted guanidines such as ethylguanidine, trimethylguanidine, phenylguanidine, diphenylguanidine, and the like, 3- (3,4-dichlorophenyl)-
3-substituted phenyl-1,1-dimethylureas such as 1,1-dimethylurea, 3-phenyl-1,1-dimethylurea, 3- (4-chlorophenyl) -1,1-dimethylurea, 2-methyl Imidazolines such as imidazoline, 2-phenylimidazoline, 2-undecylimidazoline and 2-heptadecylimidazoline; monoaminopyridines such as 2-aminopyridine; N, N-dimethyl-N- (2
-Hydroxy-3-allyloxypropyl) amine-N '
-Amine imides such as lactoimide, ethyl phosphine, propyl phosphine, butyl phosphine, phenyl phosphine, trimethyl phosphine, triethyl phosphine, tributyl phosphine, trioctyl phosphine, triphenyl phosphine, tricyclohexyl phosphine, triphenyl phosphine / triphenyl borane complex, Organophosphorus compounds such as tetraphenylphosphonium tetraphenylborate, and diazabicycloundecene such as 1,8-diazabicyclo [5,4,0] undecene-7 and 1,4-diazabicyclo [2,2,2] octane And the like. These can be used alone or 2
Used in combination of more than one species. Above all, from the viewpoint of easy production of microcapsules and ease of handling,
The above-mentioned imidazole compounds and organic phosphorus compounds are preferably used.

The organic solvent that can be included in the shell portion (wall film) of the microcapsules (component D) containing the curing accelerator is not particularly limited as long as it is liquid at normal temperature. It is necessary to select a material that does not dissolve the shell portion (wall film). Specifically, ethyl acetate, methyl ethyl ketone, acetone, methylene chloride,
In addition to organic solvents such as xylene, toluene and tetrahydrofuran, oils such as phenylxylylethane and dialkylnaphthalene can be used.

Examples of the thermoplastic resin forming the shell portion (wall film) include polyurea, polyurethane, amino resin, acrylic resin and the like. Among them, polyurea is preferred in consideration of the stability during storage.

As the polyurea, a polymer containing a repeating unit represented by the following general formula (3) as a main component is particularly preferable.

[0029]

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As described above, in the general formula (3), R
₁ and R ₂ are a hydrogen atom or a monovalent organic group, and R is a divalent organic group.

The polymer having a repeating unit represented by the above general formula (3) as a main component is obtained, for example, by a polyaddition reaction between a polyvalent isocyanate and a polyamine. Alternatively, it is obtained by reacting a polyvalent isocyanate with water.

The polyvalent isocyanate may be any compound having two or more isocyanate groups in the molecule. Specific examples thereof include m-phenylene diisocyanate, p-phenylene diisocyanate, and 2,4-tolylene diisocyanate. 2,6-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate,
3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate,
Trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate,
Butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-
Diisocyanates such as 1,4-diisocyanate, p
Phenylenediisothiocyanate, xylylene-1,
Triisocyanates such as 4-diisothiocyanate and ethylidene diisothiocyanate; tetraisocyanates such as 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; hexamethylene diisocyanate and hexanetriol; Addenda,
Adduct of 2,4-tolylene diisocyanate with prenz catechol, adduct of tolylene diisocyanate with hexanetriol, adduct of tolylene diisocyanate with trimethylolpropane, adduct of xylylene diisocyanate with trimethylolpropane, hexa Like adducts of methylene diisocyanate and trimethylolpropane, trimers of aliphatic polyvalent isocyanates such as triphenyldimethylenetriisocyanate, tetraphenyltrimethylenetetraisocyanate, pentaphenyltetramethylenepentaisocyanate, lysine isocyanate, and hexamethylene diisocyanate. And isocyanate prepolymers. These may be used alone or in combination of two or more.

Among the above polyvalent isocyanates, adducts of tolylene diisocyanate and trimethylolpropane and adducts of xylylene diisocyanate and trimethylolpropane are preferable from the viewpoint of film forming property and mechanical strength when preparing microcapsules. It is preferable to use an isocyanate prepolymer represented by polymethylene polyphenyl isocyanate such as triphenyl dimethylene triisocyanate.

On the other hand, the polyamines to be reacted with the polyvalent isocyanates may be compounds having two or more amino groups in the molecule, and specific examples thereof include diethylenetriamine, triethylenetetramine and tetraethylenepentamine. Min, 1,6-hexamethylenediamine, 1,8
-Octamethylenediamine, 1,12-dodecamethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, menthanediamine, bis (4-amino-3-methylcyclohexyl) methane, isophoronediamine, 1,3
-Diaminocyclohexane, spiroacetal diamine and the like. These may be used alone or in combination of two or more.

In the reaction between the polyvalent isocyanate and water, first, an amine is formed by hydrolysis of the polyvalent isocyanate, and this amine reacts with an unreacted isocyanate group (so-called self-polyaddition reaction). Thereby, a polymer having the repeating unit represented by the general formula (3) as a main component is formed.

The curing accelerator-containing microcapsules (D
Component) is not particularly limited as long as it can be microencapsulated, and can be prepared by various conventionally known methods. In particular, it is preferable to form a shell portion (wall film) by using an interfacial polymerization method and microencapsulate the shell portion (wall film) from the viewpoint of homogenizing the shell portion (wall film) and adjusting the thickness of the wall film.

The microcapsules (component D) containing a curing accelerator obtained by the above-mentioned interfacial polymerization method are obtained, for example, as follows. That is, a polyhydric isocyanate is dissolved therein using a liquid curing accelerator as a core component. The solution obtained in this way is oily, and this is dispersed in the water phase as an oil phase in the form of oil droplets to produce an O / W type (oil phase / water phase type) emulsion. At this time, the particle diameter of each dispersed oil droplet is 0.05 to 50 μm, preferably 0.05 to 50 μm.
The thickness is preferably about 10 to 10 μm from the viewpoint of the stability of the emulsion during polymerization.

On the other hand, when a solid curing accelerator is dissolved in an organic solvent to form a core component, an emulsion of S / O / W (solid phase / oil phase / water phase) type is obtained. Also, this emulsion type is when the curing accelerator is lipophilic,
When the curing accelerator has hydrophilicity, it is difficult to form the emulsion type, but in this case, the solubility is adjusted so that an O / O (oil phase / oil phase) emulsion type or S / O Interfacial polymerization may be performed as a / O (solid phase / oil phase / oil phase) emulsion type.

Then, polyhydric amines or polyhydric alcohols are added to the aqueous phase of the emulsion to cause interfacial polymerization with polyvalent isocyanates in the oil phase to carry out a polyaddition reaction. Microcapsules containing a curing accelerator containing a polymer as a shell (wall film) (D
Component) is obtained.

The hardening accelerator-containing microcapsules (component D) thus obtained have a core / shell structure, in which a hardening accelerator is included as a core component in a shell portion. The hardening accelerator-containing microcapsules (D component) can be isolated by a conventionally known means, for example, a method of drying after centrifugation or a method of spray drying. Further, it can be dissolved and mixed in the epoxy resin or the phenol resin. At this time, if necessary, the organic solvent in the microcapsules can be removed by using a means such as drying under reduced pressure.

The curing accelerator-containing microcapsules (D
Component) has an average particle size of 0.05 to 10 in consideration of the shearing force applied during the production of the epoxy resin composition, as described later.
It is preferable to set it in the range of μm, preferably in the range of 0.1 to 4 μm from the viewpoint of the stability and dispersibility of the microcapsules. In the present invention, the shape of the hardening agent-containing microcapsules (component D) is preferably spherical, but may be elliptical. If the microcapsules are not spherical in shape but have a uniform particle size, such as elliptical or flat, the simple average value of the longest and shortest diameters is defined as the average particle size.

The curing accelerator-containing microcapsules (D
In the component), the amount of the included curing accelerator is preferably set to 5 to 70% by weight, particularly preferably 10 to 50% by weight, based on the total amount of the microcapsules. That is, when the encapsulation amount of the curing accelerator is less than 5% by weight, the curing reaction time is too long, resulting in poor reactivity. ) Is too thin, and there is a possibility that the encapsulated curing accelerator (core component) may have poor isolation and mechanical strength.

The ratio of the thickness of the shell portion (wall film) to the particle size of the curing accelerator-containing microcapsules (component D) is preferably set to 3 to 25%, particularly preferably 5 to 25%. Is set. That is, if the ratio is less than 3%, sufficient mechanical strength cannot be obtained with respect to the shearing force (shear) applied in the kneading step in the production of the epoxy resin composition. This is because the release of the agent tends to be insufficient.

The amount of the curing accelerator-containing microcapsules (component D) is preferably set to 0.1 to 30 parts with respect to 100 parts by weight (hereinafter abbreviated as "parts") of the epoxy resin. Particularly preferably, the ratio is 5 to 15 parts. That is, if the amount of the curing accelerator-containing microcapsules (component D) is less than 0.1 part, the curing speed is too slow to cause a decrease in strength, and if it exceeds 30 parts, the curing speed is too fast. Liquidity is impaired.

The epoxy resin composition of the present invention includes:
In addition to the above components A to D, other additives can be appropriately compounded as needed.

Examples of the other additives include a flame retardant, a wax and the like.

Examples of the flame retardant include novolak type brominated epoxy resin, brominated bisphenol A type epoxy resin, antimony trioxide, antimony pentoxide and the like. These may be used alone or in combination of two or more.

Examples of the wax include compounds such as higher fatty acids, higher fatty acid esters, higher fatty acid calcium, and the like. These waxes may be used alone or in combination of two or more.

Further, the epoxy resin composition of the present invention may contain components such as silicone oil, silicone rubber, and synthetic rubber in addition to the above-mentioned other additives to reduce stress and to improve reliability in a moisture resistance reliability test. An ion trapping agent such as hydrotalcites and bismuth hydroxide may be blended for the purpose of improving the properties.

The epoxy resin composition of the present invention is, for example,
It can be manufactured as follows. First, as described above, microcapsules (D component) containing a curing accelerator are prepared by an interfacial polymerization method.

Then, after mixing the remaining other components together with the hardening accelerator-containing microcapsules (component D), the mixture is kneaded in a kneading machine such as a mixing roll machine in a heated state and melt-mixed. At this time, heat and shear force act on the hardening accelerator-containing microcapsules (D component). At this stage, however, the heat stability is good, and the microcapsules easily have a shell portion (wall film) during sealing molding. ) Is used as a shell (wall film) forming material. In particular, as described above, polyurea is suitably used as the thermoplastic resin. Further, with respect to the shearing force applied to the microcapsules, the average particle size of the microcapsules is 0.05 to 10
It is preferable to set it in the range of μm, preferably in the range of 0.1 to 4 μm from the viewpoint of the stability and dispersibility of the microcapsules.

Next, after cooling the mixture at room temperature, it is pulverized by a known means, and if necessary, tableting is carried out to produce the desired epoxy resin composition through a series of steps. it can.

In the present invention, the encapsulation of the semiconductor device using the epoxy resin composition is not particularly limited, and can be performed by a known molding method such as ordinary transfer molding.

The semiconductor device obtained in this manner is characterized in that the hardening accelerator-containing microcapsules (D) and the epoxy resin composition using the filler (component C) made of the acidic metal element compound having the specific metal element are used. Component), a uniform semiconductor package can be obtained by resin sealing with an epoxy resin composition having excellent curing stability without lowering the fluidity during package production.

Next, examples will be described together with comparative examples.

Prior to the examples, hardening accelerator-containing microcapsules were prepared according to the method described below.

[Hardening Accelerator-Containing Microcapsules] The microcapsules were produced by the above-described interfacial polymerization method. More specifically, an oil phase was prepared by uniformly dissolving 10 parts of an adduct of 3 mol of xylylene diisocyanate and 1 mol of trimethylolpropane in 4 parts of triphenylphosphine as a curing agent. Further, an aqueous phase composed of 95 parts of distilled water and 5 parts of polyvinyl alcohol was separately prepared, and the oil phase prepared above was added thereto, and the mixture was homomixed (8000 rpm).
The mixture was emulsified to give an emulsion state, and this was charged into a polymerization reactor equipped with a reflux tube, a stirrer, and a dropping funnel.

On the other hand, 13 parts of an aqueous solution containing 3 parts of triethylenetetramine was prepared, placed in a dropping funnel provided in the polymerization reactor, dropped into the emulsion in the reactor, and polymerized at 70 ° C. for 3 hours. Then, microcapsules were produced. The polyurea shell containing triphenylphosphine as described above (shell thickness ratio to particle size of 20)
%) Structured microcapsules (average particle size 2μ)
m).

On the other hand, the following components were prepared.

[Epoxy resin A1] 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'
-Tetramethylbiphenyl epoxy resin (epoxy equivalent 200)

[Epoxy resin A2] Cresol novolak type epoxy resin (epoxy equivalent 198)

[Phenol resin B1] Phenol novolak resin (hydroxyl equivalent 105)

[Phenol resin B2] The above-mentioned general formula (2)
Phenol aralkyl resin represented by the formula (hydroxyl equivalent 17
5: In the general formula (2), n = 0 to 21)

[Brominated bisphenol A type epoxy resin] An epoxy equivalent of 275 and a bromine content of 36%

[0065]

Examples 1-4, Comparative Examples 1-4 The following Tables 1 and 2
The components shown in Table 1 were blended in the proportions shown in the same table, kneaded and cooled with a mixing roll machine (100 ° C.), and then pulverized to obtain a desired powdery epoxy resin composition. The type and average particle size of the filler used, and (Δ
H / mC) value (kcal) is also shown in Tables 1 and 2.

[0066]

[Table 1]

[0067]

[Table 2]

Using the powdered epoxy resin compositions of Examples and Comparative Examples thus obtained, the following evaluation tests (except for the initial gel time at 175 ° C. and 3
Gel time at 175 ° C. using the powder left at 0 ° C. × 7 days, evaluation of hardness and releasability after 175 ° C. × 60 seconds). The results are shown in Tables 3 and 4 below.

[Gel time at 175 ° C] 175 ° C
Was measured according to a hot plate gel time.

[Gel time at 175 ° C. after standing at 30 ° C. × 7 days] After standing at 30 ° C. × 7 days, the gel time at 175 ° C. was measured in the same manner as described above.

[Hardness after 175 ° C. × 60 seconds] 175 ° C. ×
Immediately after molding under the condition of 60 seconds, the hardness during heating was measured using a Shore D hardness meter.

[Releasability] First, a mold having a three-layer structure (upper die 10, middle die 11, lower die 12) as shown in FIG. 1 was formed under the conditions of 175 ° C. × 60 seconds. The load at the time of mold release in the cured epoxy resin composition was measured. In the figure, 13 is a cull, 14 is a sprue, 15 is a runner, and 16 is a cavity. As shown in FIG. 2, the measurement of the load at the time of releasing the mold is performed by moving the middle mold 11 of the molding
The epoxy resin composition cured body 19 in the middle mold 11 was removed from above from above using a push-pull gauge 18. The load value at this time was measured.

Further, the powdered epoxy resin compositions obtained in the above Examples and Comparative Examples were preformed into tablets (diameter: 24.5 mm × thickness: 20 mm), and the tablets were subjected to a temperature condition of 40 ° C. For 7 days. Then, the semiconductor device [8]
0-pin 4-way flat package: QFP-80 (14
mm x 20 mm x 2.7 mm thickness), lead frame M
F202, semiconductor element (8 mm × 8 mm × thickness 0.37
mm)] by transfer molding (conditions: 175 ° C. × 2
Min).

[Evaluation of Molding Failure] First, the number of molding failures (out of 120) of the obtained semiconductor devices was measured. That is, an automatic molding machine (manufactured by TOWA, VP
In S-40), use the above QFP-80 (14 mm x 20 mm x
(2.7 mm thick) was molded into 10 shots, and the formation of voids was evaluated. The formation of the above voids was measured by a soft X-ray apparatus, and those having a diameter of 0.1 mm or more were determined to be defective. The results are shown in Tables 3 and 4 below.

[0075]

[Table 3]

[0076]

[Table 4]

From the results in Tables 3 and 4, it can be seen that all the products of Examples have a short gel time at 175 ° C. after standing at 30 ° C. × 7 days, and have a high hardness after 175 ° C. × 60 seconds. . In addition, since the mold release property is excellent and the occurrence rate of defective products is 0%, the epoxy resin composition of the example has high storage stability, and is used as a sealing material for semiconductor devices. It turns out that it is suitable for. Accordingly, a semiconductor device having high reliability can be obtained by using the epoxy resin composition of the example as a sealing material for a semiconductor device. On the other hand, the comparative example product has a longer gel time at 175 ° C. after leaving at 30 ° C. × 7 days, and
The hardness after 175 ° C. × 60 seconds is also low.

[0078]

As described above, the epoxy resin composition of the present invention comprises an epoxy resin (A component) and a phenol resin (B
Component) and a filler (component (C)) composed of an acidic metal element compound having a specific metal element and microcapsules (D component) containing a curing accelerator. As described above, as the filler, while using the acidic metal element compound having the specific metal element and using a microencapsulated curing accelerator, the curing of the metal element and the curing accelerator in the filler is performed. The reaction is suppressed, and an epoxy resin composition having excellent curing stability even after storage can be obtained. When the epoxy resin composition having excellent curing stability is used as a sealing material for a semiconductor device, a highly reliable semiconductor device can be obtained. Furthermore, the epoxy resin composition of the present invention is most suitable as a sealing material for a semiconductor device as described above, but is also useful in other fields, for example, fields such as adhesion and paint.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method for molding a cured epoxy resin composition used in a method for evaluating mold release properties.

FIG. 2 is an explanatory view showing a method for measuring a load, which is a method for evaluating releasability.

Continuation of the front page (72) Inventor Sadahito Misumi 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Tsutomu Nishioka 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko stock Within the company (72) Inventor Takeshi Taniguchi 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation

Claims (4)

[Claims] 1. An epoxy resin composition comprising the following components (A) and (B) and components (C) and (D). (A) Epoxy resin. (B) a phenolic resin. (C) A filler comprising an acidic metal element compound having a metal element satisfying the following condition (α). (Α) A value (ΔH / mC) obtained by dividing the heat of dissociation ΔH of the oxide of the metal element by the product of the number m of cations and the coordination number C with respect to oxygen atoms (ΔH / mC) is 400 to 1500 kcal. (D) A hardening accelerator-containing microcapsule having a core / shell structure in which a core made of a hardening accelerator is covered with a shell made of a thermoplastic resin. 2. The epoxy resin composition according to claim 1, wherein the thermoplastic resin constituting the shell part of the microcapsule containing the curing accelerator, which is the component (D), is a polyurea. 3. The method according to claim 1, wherein the acidic metal element compound as the component (C) is aluminum oxide, silicon dioxide, silicon carbide,
3. The method according to claim 1, wherein the at least one is selected from the group consisting of trisilicon tetranitride, boron nitride and boron carbide.
The epoxy resin composition according to the above. 4. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition according to claim 1.