JPH11217486A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition which can give a cured product reduced in the formation of internal and surface voids, being excellent in fillability into a semiconductor device and having good adhesion to various substrates and can be desirably used e.g. for sealing semiconductor devices by potting or the COB system. SOLUTION: This composition comprises (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) 5×10<-6> -1×10<-1> pt.wt., per 100 pts.wt. total of components A and B, fluorine-containing and silicon-containing compound represented by the formula (wherein R and R<1> are each independently an unsubstituted or substituted monovalent hydrocarbon group; k is an integer of 10-80; m is an integer of 1-20; and n is an integer of 1-10). It is desirable that the compound of the formula has a surface tension of 10-30 dyn/cm at room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a cured product which has little voids inside and on the surface, has excellent permeability to semiconductor devices, and has good adhesiveness to various substrates, and uses a potting or COB method. The present invention relates to an epoxy resin composition that can be suitably used for sealing a semiconductor device and the like.

[0002]

BACKGROUND OF THE INVENTION Epoxy resin compositions are used not only in the electric and electronic fields but also in all fields due to their excellent cured physical properties. At present, it is used under various flow characteristics, such as extremely lowering the viscosity or using it with a high thixotropic property.

[0003] For this reason, in the epoxy resin composition, air bubbles due to entrapment at the time of potting or dripping cannot be removed to the outside during the curing process, remain as voids inside or on the surface of the cured product, or during the transfer molding. It has been pointed out that there are problems with air bubbles, such as air entrained when flowing into the cavity from the gate is not exhausted but remains as an internal void and becomes a defective product.

On the other hand, recently, potting and the COB method have been widely used as a sealing method of a semiconductor device. In this method, the resin must be poured into a very narrow space between the gold wires extending from the semiconductor element, so that the conventional liquid epoxy resin composition has a problem in filling property.

In this case, to reduce voids, Florad FC-170C, FC-430 and FC-431 are used.
(Sumitomo 3M Co., Ltd.) and other fluorine-based surfactants and K
It is well known to use silicone-based surfactants such as F351, KF945, and KF618 (manufactured by Shin-Etsu Chemical Co., Ltd.).

However, at present, even when these surfactants are used, the effect of preventing the generation of voids has not yet been satisfactory. Further, potting and COB methods have not yet been sufficiently studied, and only measures to reduce the viscosity of the resin or to reduce the thixotropy of the resin have been made to improve the filling property.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is a cured product having little internal and surface voids, having excellent permeability to semiconductor devices, and having good adhesion to various substrates. It is an object of the present invention to provide an epoxy resin composition which gives the following.

[0008]

Means for Solving the Problems and Embodiments of the Invention The present inventors have made intensive studies to achieve the above object, and as a result, have found that an epoxy resin composition containing an epoxy resin, a curing agent and an inorganic filler has: By blending a fluorine-containing and silicon-containing compound represented by the following structural formula (1) in an appropriate amount, the permeability to a semiconductor device becomes very good, and a sufficient defoaming and defoaming effect is exhibited. In addition, the surface tension is reduced, and therefore, the occurrence of voids inside and on the surface of the cured product can be sufficiently reduced, and the adhesion to various substrates is also good. The present inventors have found that they can be suitably used for encapsulating a semiconductor device by potting or the COB method, and have accomplished the present invention.

[0009]

Embedded image (Wherein, R and R ¹ are each independently an unsubstituted or substituted monovalent hydrocarbon group, k is an integer of 10 to 80, and m is 1
Is an integer of 1 to 20, and n is an integer of 1 to 10. )

Accordingly, the present invention provides (A) an epoxy resin,
(B) a curing agent, (C) an inorganic filler, and (D) a fluorine and silicon atom-containing compound represented by the above structural formula (1) in an amount of 5 × with respect to 100 parts by weight of the total amount of the epoxy resin and the curing agent.
Provided is an epoxy resin composition characterized by containing 10 ^-6 to 1 × 10 ^-1 part by weight.

Hereinafter, the present invention will be described in more detail. The epoxy resin composition of the present invention contains an epoxy resin, a curing agent, an inorganic filler and the like.

Here, as the epoxy resin used in the present invention, any epoxy resin having two or more epoxy groups in one molecule can be used. In particular, bisphenol A type epoxy resin, bisphenol A Bisphenol type epoxy resin such as F type epoxy resin, phenol novolak type epoxy resin, novolak type epoxy resin such as cresol novolak type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, triphenol alkane type epoxy resin, phenol aralkyl Epoxy resin, cyclopentadiene epoxy resin and the like.

When a liquid epoxy resin composition is used,
Among the above, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin are typically used.

When the composition is used for transfer molding, any curing agent can be used as long as it is a phenol resin having two or more phenolic hydroxyl groups in one molecule. Novolak type phenolic resins such as phenol novolak resin, cresol novolak resin, phenol aralkyl resin, triphenol alkane type resin, naphthalene type phenol resin,
Cyclopentadiene-type phenol resin and the like are preferably used. The amount of the curing agent used is preferably such that the phenolic hydroxyl group in the phenolic resin is 0.5 to 2 mol, particularly 0.8 to 1.3 mol, per 1 mol of the epoxy group in the epoxy resin. .

In this case, as a curing accelerator, for example, a phosphorus-based, imidazole derivative, cycloamidine-based derivative or the like can be blended. The amount of these curing accelerators added is 100% by weight of the total amount of the epoxy resin and the curing agent. It is preferably 0.05 to 10 parts by weight based on parts.

When the liquid epoxy resin composition is used, the curing agent is preferably an acid anhydride such as methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhymic anhydride. used. When such an acid anhydride is used as a curing agent, 0.3 to 0.7 mol, particularly 0.4 to 0.6 mol, of the acid anhydride is blended with respect to 1 mol of the epoxy group in the epoxy resin. It is desirable that the compounding amount is 0.
If the amount is less than 3 mol, the curability may be insufficient.
If it exceeds 7 moles, unreacted acid anhydride remains, which may lower the glass transition temperature.

Further, when an acid anhydride is used as a curing agent, 2-methylimidazole, 2-methylimidazole,
Ethyl-4-methylimidazole, 1-cyanoethyl-
An imidazole derivative such as 2-methylimidazole and 2-phenyl-4,5-dihydroxymethylimidazole can be blended.

These imidazole derivatives can be used both as a curing accelerator for an acid anhydride-based curing agent and as a curing agent for an epoxy resin. However, when used as a curing accelerator, the epoxy resin and the curing agent can be used. Total amount of 100
0.01 to 10 parts by weight, especially 0.5 to 5 parts by weight based on parts by weight
It is preferable to add in the range of parts by weight. If the addition amount is less than 0.01 part by weight, the curability may decrease. If the addition amount exceeds 10 parts by weight, the curability is excellent, but the storage stability tends to decrease.

As the curing agent, carboxylic acid hydrazides such as dicyandiamide, adipic hydrazide and isophthalic hydrazide can be used in addition to the above.

In the present invention, various conventionally known inorganic fillers can be added for the purpose of reducing the expansion coefficient. As the inorganic filler, for example, fused silica, crystalline silica, alumina, boron nitride, aluminum nitride, silicon nitride, magnesia, magnesium silicate and the like are used. When the semiconductor device is an element generating a large amount of heat, it is desirable to use alumina, boron nitride, aluminum nitride, silicon nitride, or the like, which has as high a thermal conductivity as possible and has a small expansion coefficient among these, and May be used by blending with fused silica or the like.

The particle size distribution of the inorganic filler is such that the average particle size is 2
Those having a maximum particle size of not more than 30 μm and not more than 74 μm are desirable. If the average particle diameter is smaller than 2 μm, the viscosity becomes high and a large amount of the particles may not be filled. If the average particle diameter exceeds 30 μm, the coarse particle diameter increases, and there is a possibility that the gate is clogged or a thin needle of a dispenser is blocked.

The shape of the filler is not particularly limited.
Flake-like, dendritic, spherical and other fillers can be used alone or in combination. In addition, ultrafine silica such as Aerosil can be added to impart thixotropy.

It is preferable to use those fillers which have been previously surface-treated with a coupling agent such as a silane coupling agent or a titanium-based coupling agent.

When an inorganic filler is used, 100 to 10 parts by weight of the total amount of the epoxy resin and the curing agent is used.
00 parts by weight is preferred.

In the present invention, the epoxy resin composition containing the epoxy resin, the curing agent and the inorganic filler is added to a fluorine- and silicon-atom-containing compound represented by the following structural formula (1) (that is, a perfluoroalkylethyl group-containing compound). (Diorganopolysiloxane).

[0026]

Embedded image (Wherein, R and R ¹ are each independently an unsubstituted or substituted monovalent hydrocarbon group, k is an integer of 10 to 80, and m is 1
Is an integer of 1 to 20, and n is an integer of 1 to 10. )

R and R ¹ in the above formula (1) are each independently the same or different, unsubstituted or substituted monovalent hydrocarbon groups, preferably having 1 to 10 carbon atoms. A monovalent hydrocarbon group, more preferably an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms excluding an aliphatic unsaturated group, specifically, a methyl group, an ethyl group, a propyl group, Alkyl groups such as isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, cyclohexyl group, and octyl group, aryl groups such as phenyl group, tolyl group, xylyl group, and naphthyl group, vinyl group, allyl group, and propenyl group Groups, alkenyl groups such as isopropenyl group, butenyl group, isobutenyl group, hexenyl group, aralkyl groups such as benzyl group and phenylethyl group, and 3,3,3-trifluoropropyl group Include a halogen-substituted alkyl group, particularly a methyl group, a propyl group, a phenyl group are preferable. Further, a plurality of R and R ¹ may be each independently the same or different groups.
In particular, those in which 70 to 100 mol% are methyl groups are preferred. k is an integer of 10 to 80, m is an integer of 1 to 20, preferably 2 to 12, more preferably 2 to 8, and n is 1 to 1.
It is an integer of 0, preferably 3 to 8, and more preferably 6 to 8.

Such a compound of the formula (1) is a linear diorganopolysiloxane in which both ends of the molecular chain are blocked with a trimethylsiloxy group and the number of silicon atoms (or degree of polymerization) in the molecule is 122 or less. Has 1 to 20 perfluoroalkylethyl group-containing siloxane units randomly in a siloxane chain, and is usually liquid (oil-like) at normal temperature (25 ° C.). Can be exemplified by the following perfluoroalkylethyl group-containing organopolysiloxane compounds.

[0029]

Embedded image (Where k and m have the same meanings as above).

[0030]

Embedded image (Wherein, R and R ¹ have the same meanings as described above.)

The compound of the above formula (1) has a surface tension of 10 to 30 dyne / cm at room temperature (25 ° C.), especially 16 to 2 dyne / cm.
It is preferable to have a property of 3 dyne / cm. If the surface tension is less than 10 dyne / cm, a satisfactory effect may not be obtained. If the surface tension is more than 30 dyne / cm, defoaming properties may be insufficient and foaming may be easily caused. There is.

The amount of the compound of the above formula (1) is 5 × 1 with respect to 100 parts by weight of the total amount of the epoxy resin and the curing agent.
0 ^-6 to 1 × 10 ^-1 parts by weight, preferably 5 × 10 ^{-5 to} 5 ×
^10-3 parts by weight and, 5 × 10 ^-6 sufficient defoaming is less than parts by weight, no foam breaking effect, also the permeability to narrow gaps from the inability to lower the surface tension of the composition If it is insufficient, if it exceeds 1 × 10 ^-1 part by weight, on the contrary, foamability will be obtained and adhesiveness will be reduced.

The epoxy resin composition of the present invention may contain a silicone rubber, a silicone oil, a silicone-modified resin, a liquid polybutadiene rubber, or the like for the purpose of reducing stress in addition to the above components.

For the purpose of lowering the viscosity, the composition of the present invention contains a conventionally known n-butyl glycidyl ether, phenyl glycidyl ether, styrene oxide, t-butylphenyl glycidyl ether or dicyclopentadiene diepoxide. Such diluents can be added.

Further, in addition to the silane coupling agent and the titanium coupling agent, a coupling agent such as an aluminum coupling agent, a coloring agent such as carbon black, and a surfactant other than the compound of the above formula (1). In some cases, a nonionic surfactant, a fluorine surfactant, a wetting enhancer such as silicone oil, an antifoaming agent, and the like can be added. In addition, the addition amount of these additives,
The amount can be a usual amount within a range not to impair the effects of the present invention.

The epoxy resin composition of the present invention is prepared, for example, by stirring, dissolving, mixing and dispersing the epoxy resin and the curing agent simultaneously or separately while adding a heat treatment as required, and adding an inorganic filler to the above-mentioned formula ( It can be obtained by adding, mixing, stirring, and dispersing the compound of 1) and other additives. Mixing, stirring, dispersion and other devices are not particularly limited, stirring, a raikai machine equipped with a heating device,
A three-roll, ball mill, planetary mixer or the like can be used.

When an epoxy resin for transfer molding is used, the epoxy resin and a curing agent, an inorganic filler,
The compound can be produced by uniformly mixing the compound of the formula (1) or the like with a high-speed stirrer, and kneading the mixture with a hot double roll or a continuous kneader. Further, these devices may be used in appropriate combination.

The epoxy resin composition of the present invention can be easily cured by heating, and the curing conditions are not particularly limited. However, it is usually desirable to set the temperature at 100 to 190 ° C. for 0.5 to 10 hours.

[0039]

Industrial Applicability The epoxy resin composition of the present invention has excellent filling properties in the gap between a semiconductor device and a substrate, has little internal and surface voids, and has good adhesiveness to various substrates. It gives a cured product, and can be suitably used for potting, sealing of a semiconductor device by a COB method, and the like.

[0040]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following formulas, Me represents a methyl group and Ph represents a phenyl group, and all parts in each example are parts by weight.

Examples 1 to 8, Comparative Examples 1 to 4 Tables 1 and 2
As shown in the figure, bisphenol A is used as a liquid epoxy resin.
Type epoxy resin (RE310S: manufactured by Nippon Kayaku Co., Ltd.), acid anhydride as a curing agent (Ricassid MH700: manufactured by Nippon Rika Co., Ltd.), fused silica (SE15 (average particle size: 15 μm):
Tokuyama Soda Co., Ltd.), silane coupling agent (γ-glycidoxypropyltrimethoxysilane KBM403: manufactured by Shin-Etsu Chemical Co., Ltd.), curing catalyst (UCAT5002: manufactured by Asahi Kasei Corporation), containing fluorine and silicon atoms represented by the following structural formulas Compounds (perfluoroalkylethyl group-containing silicone oils (i) to (iv)) were blended to produce an epoxy resin composition.

[0042]

Embedded image

[0043]

Embedded image

Various properties of the obtained epoxy resin composition were measured by the following methods. The results are shown in Tables 1 and 2. Measurement method of various properties Viscosity: Measured at room temperature using a Brookfield viscometer. Permeability: A glass plate is placed on an alumina substrate with a gap of 70 μm, and an epoxy resin composition heated to 60 ° C. is dropped on the edge of the glass plate, and the resin naturally fills the gap between the glass and alumina by surface tension. The penetration speed at the time of penetration was determined. Surface void: 5 completely degassed in 1 liter flask
100 g of the resin composition was added, the stirring rod was rotated at a speed of 120 revolutions / minute for 10 minutes, air was entrapped inside, and then poured into an aluminum petri dish having a diameter of 50 mm and a depth of 15 mm, and then at 100 ° C. for 1 hour. After curing at 150 ° C. for 2 hours, the number of surface voids was counted. Bubble generation amount: Only 5 g of the resin components of the resin compositions shown in Tables 1 and 2 that were completely defoamed were placed in a 300 cc beaker, and the pressure was reduced to 750 mmHg, and the amount of bubble generation at that time was measured.

From the results shown in Tables 1 and 2, it was confirmed that the epoxy resin composition of the present invention was excellent in permeability and the generation of surface voids of the cured product was extremely small.

[0046]

[Table 1]

[0047]

[Table 2]

Example 9, Comparative Example 5 Epoxycresol novolak resin (EOCN1020: manufactured by Nippon Kayaku Co., Ltd.)
167.9 parts, phenol novolak resin (TD209
3: 90.6 parts of Dainippon Ink and 36.6 parts of a brominated epoxy resin (BREN-S: manufactured by Nippon Kayaku), fused silica (RD8 (average particle size: 8 μm): manufactured by Tatsumori) 67
8.9 parts, carbon black 3 parts, carnauba wax 3
Part, silane coupling agent (γ-glycidoxypropyltrimethoxysilane KBM403: manufactured by Shin-Etsu Chemical Co., Ltd.)
3 parts, 2.4 parts of a curing catalyst (triphenylphosphine TPP: manufactured by Hokuko Chemical Co., Ltd.), and 0.29 parts of a perfluoroalkylethyl group-containing silicone oil of the above formula (i) as a compound containing fluorine and silicon atoms, After mixing with a high-speed mixing device, the mixture was kneaded with a continuous kneading device to obtain an epoxy resin composition for transfer molding (Example 9).

An epoxy resin composition for transfer molding (Comparative Example 5) was obtained by kneading in the same manner as in Example 9 except that no compound containing fluorine and silicon atoms was used.

After curing the epoxy resin compositions of Example 9 and Comparative Example 5 at a temperature of 175 ° C. and a molding pressure of 70 kg / cm ² for 2 minutes, the spiral flow and the occurrence of internal voids were determined as follows. The evaluation was performed according to the method shown in Table 3 shows the results. Spiral flow: Measured using a mold in accordance with EMMI Tsuki. Internal void: 1 with 8mm square silicone chip
After sealing the 00-pin QFP package under the above conditions, the number of internal voids in the package was measured with a soft X-ray device. The number of voids is the number in 10 packages.

From the results shown in Table 3, it was found that the epoxy resin composition of the present invention has less internal voids.

[0052]

[Table 3]

Claims (2)

[Claims] (1) an epoxy resin, (B) a curing agent,
(C) an inorganic filler, (D) a fluorine and silicon atom-containing compound represented by the following structural formula (1) in an amount of 5 × 10 ⁻⁶ to 1 × 1 based on 100 parts by weight of the total amount of the epoxy resin and the curing agent.
An epoxy resin composition comprising 0 to ¹ part by weight. Embedded image (Wherein, R and R ¹ are each independently an unsubstituted or substituted monovalent hydrocarbon group, k is an integer of 10 to 80, and m is 1
Is an integer of 1 to 20, and n is an integer of 1 to 10. ) 2. The epoxy resin composition according to claim 1, wherein the compound of the structural formula (1) has a surface tension of 10 to 30 dyne / cm at room temperature.