JP3104566B2 - Epoxy resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in permeability into a gap between a semiconductor element and a substrate, has little voids inside and on the surface of a cured product, and has good adhesion to various bases. In particular, the present invention relates to an epoxy resin composition that can be suitably used for bonding a semiconductor element to a substrate by a flip chip method.

[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 or using in a state of high thixotropy.

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

On the other hand, recently, a flip chip method has been widely used as a method for connecting a semiconductor element to a substrate. In this method, since the resin must be poured into a very narrow space between the semiconductor element and the substrate, the conventional liquid epoxy resin composition has a problem in filling property.

In order to reduce voids, fluorine-based surfactants such as Florad FC-170C, FC-430, FC-431 (manufactured by Sumitomo 3M), and KF35
It is well known to use silicone-based surfactants such as 1, KF945, 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, the flip chip method has not yet been sufficiently studied, and only measures to reduce the viscosity 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 problems, and has excellent permeability into a gap between a semiconductor element and a substrate, has a small generation of internal and surface voids, and can be applied to various substrates. An object of the present invention is to provide an epoxy resin composition which gives a cured product having good adhesiveness.

[0008]

Means for Solving the Problems and Actions The present inventors have made intensive studies to achieve the above object, and as a result, an epoxy resin composition containing an epoxy resin, a curing agent and an inorganic filler has the following structural formula ( By compounding the compound containing fluorine and silicon atoms shown in I), the permeability to the gap between the semiconductor element and the substrate is very good, and a sufficient defoaming and defoaming effect is exhibited, and the surface is also improved. The tension is reduced, and therefore, the generation of voids inside and on the surface of the cured product can be sufficiently reduced, and the adhesiveness to various substrates is also good. The present inventors have found that the method can be suitably used for connecting a semiconductor element to a substrate by a method, and have accomplished the present invention.

[0009]

Embedded image (Wherein, R is an organic group, M is a hydrogen atom or carbon number 1 to
6 is a monovalent hydrocarbon group, n is a positive integer, m is 0, 1
Or 2, p is 2 or 3, and q is a positive integer. )

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 (I) in an amount of 0.1 parts by weight based on 100 parts by weight of the total amount of the epoxy resin and the curing agent.
The present invention provides an epoxy resin composition, which is contained in an amount of from 0.01 to 5 parts 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 Examples thereof include an F-type epoxy resin, a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, a naphthalene-type epoxy resin, a biphenyl-type epoxy resin, and a cyclopentadiene-type epoxy resin.

When a liquid epoxy resin composition is used,
Among them, 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. Phenol novolak resin, cresol novolak resin, phenol aralkyl resin, naphthalene-type phenol resin, cyclopentadiene-type phenol resin and the like are preferably used. The amount of the curing agent to be used is preferably such that the hydroxyl group of the phenol resin is 0.5 to 2 mol, particularly 0.8 to 1.3 mol, per 1 mol of the epoxy group of 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.

In the case of a liquid epoxy resin composition, the curing agent is preferably an acid anhydride in general 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. 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 amount is less than 0.01 part by weight, the curability may decrease. If the amount exceeds 10 parts by weight, the curability may be excellent but the preservability 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 inorganic fillers conventionally known 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 element is an element generating a large amount of heat, it is preferable to use alumina, boron nitride, aluminum nitride, silicon nitride, or the like having a large thermal conductivity and a small expansion coefficient among these elements. 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.

The amount of the inorganic filler used is 100 to 1000 parts by weight based on 100 parts by weight of the total amount of the epoxy resin and the curing agent.
Parts by weight are preferred.

In the present invention, a compound containing a fluorine atom and a silicon atom represented by the following structural formula (I) is blended with the epoxy resin composition containing the epoxy resin, the curing agent and the inorganic filler.

[0026]

Embedded image (Wherein, R is an organic group, M is a hydrogen atom or carbon number 1 to
6 is a monovalent hydrocarbon group, n is a positive integer, m is 0, 1
Or 2, p is 2 or 3, and q is a positive integer. )

R in the above formula (I) is preferably an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, specifically, an alkyl group such as a methyl group, an ethyl group or a butyl group; Examples include an aryl group such as a phenyl group and a halogen-substituted alkyl group such as a 3,3,3-trifluoropropyl group.
M represents a hydrogen atom, a methyl group, an ethyl group, a butyl group,
Examples include an alkyl group such as a propyl group, and a phenyl group. n is specifically preferably from 0 to 2, particularly preferably from 0 to 1, and q
Is preferably 1 to 100, particularly preferably 1 to 50.

Specific examples of such a compound of the formula (I) include the following compounds.

[0029]

Embedded image

[0030]

Embedded image

The compound of the above formula (I) has a surface tension of 19 to 25 dyne / cm, particularly 19 to 25 dyne at room temperature.
/ Cm and a surface tension of 19
If it is less than dyne / cm, a satisfactory effect may not be obtained. If it exceeds 25 dyne / cm, defoaming properties may be insufficient and foaming may be easily caused.

The amount of the compound of formula (I) used is 0.0 to 100 parts by weight of the total amount of the epoxy resin and the curing agent.
1 to 5 parts by weight, preferably 0.03 to 2 parts by weight,
If it is less than 0.01 part by weight, there is no sufficient defoaming and foam breaking effect,
In addition, since the surface tension of the composition cannot be reduced, the permeability into narrow gaps is insufficient. If the composition exceeds 5 parts by weight, foaming properties will be produced, and the 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.

In order to reduce the viscosity, the composition of the present invention may contain a compound such as n-butyl glycidyl ether, phenyl glycidyl ether, styrene oxide, t-butyl phenyl glycidyl ether or dicyclopentadiene diepoxide. A suitable diluent can be added.

Further, in addition to the above-mentioned silane coupling agent and titanium-based coupling agent, a coupling agent such as an aluminum-based coupling agent, a coloring agent such as carbon black, and a surfactant other than the compound of the above formula (I) 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 necessary, and adding an inorganic filler to the mixture of the above formula ( It can be obtained by adding, mixing, stirring, and dispersing the compound of I) 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 (I) and the like with a high-speed stirring device and kneading the mixture with a hot double roll or a continuous kneading device. 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 element 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 connecting a semiconductor element to a substrate by a flip chip method.

[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. All parts in each example are parts by weight.

Examples 1 to 8 and Comparative Examples 1 to 4 As shown in Table 1, bisphenol A type epoxy resin (RE310: manufactured by Nippon Kayaku Co., Ltd.) as a liquid epoxy resin and acid anhydride (MH700: Shin Nippon Rika Co., Ltd., fused silica (SE15: Tokuyama Soda Co., Ltd.), silane coupling agent (KBM403: Shin-Etsu Chemical Co., Ltd.), curing catalyst (UC
AT5002: manufactured by Asahi Kasei Corporation) and a compound containing fluorine and a silicon atom represented by the following structural formula were blended to produce an epoxy resin composition.

[0042]

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Various properties of the obtained epoxy resin composition were measured by the following methods. The results are also shown in Table 1. 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 rpm for 10 minutes, air was drawn into the inside, and then poured into an aluminum petri dish having a diameter of 50 mm and a depth of 15 mm. After curing at 150 ° C. for 2 hours, the number of surface voids was counted.

From the results shown in Table 1, 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.

[0045]

[Table 1]

Example 9, Comparative Example 5 Epoxy cresol novolak resin (EOCN1020, manufactured by Nippon Kayaku Co., Ltd.)
167.9 parts, phenol resin (TD2093, manufactured by Dainippon Ink and Chemicals) 90.6 parts, brominated epoxy resin (BR
EN-S, 36.6 parts, manufactured by Nippon Kayaku Co., Ltd., fused silica (R
D8, manufactured by Tatsumorisha) 678.9 parts, carbon black 3
Parts, carnauba wax 3 parts, silane coupling agent (K
BM403, 3 parts by Shin-Etsu Chemical Co., Ltd., curing catalyst (TP
P, manufactured by Hokuko Chemical Co., Ltd.) 2.4 parts, compound 0.3 part of the compound of the above formula (1) as a fluorine-based surfactant was mixed, mixed with a high-speed stirrer, and kneaded with a continuous kneader to perform transfer molding. An epoxy resin composition for use (Example 9) was obtained.

Also, kneading was performed in the same manner as in Example 9 except that no fluorine-based surfactant was used, to obtain an epoxy resin composition for transfer (Comparative Example 5).

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 FIG. The results are also shown in Table 2. Spiral flow : measured using a mold conforming to the EMMI standard. 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 2, it was found that the epoxy resin composition of the present invention has less internal voids.

[0050]

[Table 2]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiromasa Yamaguchi 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside the Silicone Electronics Materials Research Laboratory Shin-Etsu Chemical Co., Ltd. (72) Kazumasa Sumida, Usui-gun, Gunma Prefecture Shinoda Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory (72) Inventor Sachi Wakao 1-10 Matsuida Town, Hatsumi-gun, Gunma Pref. (56) References JP-A-1-144438 (JP, A) JP-A-5-262961 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 63/00-63 / 10 C08K 5/541-5/5419

Claims (2)

(57) [Claims] (1) an epoxy resin, (B) a curing agent,
(C) an inorganic filler, (D) 0.01 to 5 parts by weight of a fluorine and silicon atom-containing compound represented by the following structural formula (I) based on 100 parts by weight of the total amount of the epoxy resin and the curing agent. An epoxy resin composition characterized by comprising: Embedded image (Wherein, R is an organic group, M is a hydrogen atom or carbon number 1 to
6 is a monovalent hydrocarbon group, n is a positive integer, m is 0, 1
Or 2, p is 2 or 3, and q is a positive integer. ) 2. The epoxy resin composition according to claim 1, wherein the compound of the structural formula (I) has a surface tension of 19 to 25 dyne / cm at room temperature.