JPH10212394A - Epoxy resin composition for semiconductor sealing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin compsn. for semiconductor sealing which can reduce voids occurring in a molded item and has an improved resistance to soldering crack by compounding an epoxy resin, a phenol resin curative, a cure accelerator, an inorg. filler, and a silicone oil having alkoxysilane or alkoxy groups, alcoholic hydroxyl groups, and polyether groups. SOLUTION: At least one silicone oil selected from among silicone oils represented by formulas I, II, III, and IV is used. The variables and constants of these formulas are shown by formulas V and VI, and in these formulas, R1 is a 1-30C alkylene; R2 and R3 are each methyl or ethyl; R4 is a 1-30C alkylene or a 1-30C hydrocarbon group contg. ether bonds; R5 is a 1-5C alkyl; and d+e>=1. Pref. the compsn. further contains at least one silane coupling agent selected from among silane coupling agents represented by formulas VII and VIII.

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 for semiconductor encapsulation which has no voids in a molded product and has excellent reliability, particularly excellent solder crack resistance.

[0002]

2. Description of the Related Art Semiconductor packages have come to take various forms in order to make electronic products lighter and thinner, smaller, denser, more functional, and less expensive. In particular, in recent years, various improvements have been made to epoxy resin compositions for encapsulating semiconductor elements (hereinafter referred to as resin compositions) for surface mounting. The resin composition containing epoxy resin, phenolic resin curing agent, curing accelerator, and inorganic filler as main components needs to be made to have low water absorption especially for the above-mentioned surface mounting. 90 in the resin composition
Weight percent. However, when the amount of the inorganic filler increases, it becomes difficult to uniformly disperse the resin component and the inorganic filler. As a result, when a semiconductor element is sealed with such a resin composition, there is a disadvantage that many voids are generated in a molded product.

As a technique for uniformly dispersing a resin component and an inorganic filler, a method of adding a silicone oil (Japanese Patent Publication No. 2-36148) has been considered as an effective means. However, these methods alone are insufficiently dispersed, and as a result, in a resin composition which is highly filled with an inorganic filler, generation of voids in a molded article cannot be completely solved. In addition, the means of adding silicone oil causes a decrease in adhesive strength and a decrease in strength at the time of heating.

[0004]

SUMMARY OF THE INVENTION The present invention provides a highly reliable epoxy resin composition for semiconductor encapsulation capable of reducing voids generated in a molded product during molding and improving solder crack resistance. It is.

[0005]

The present invention comprises (A) an epoxy resin, (B) a phenolic resin curing agent, (C) a curing accelerator, (D) an inorganic filler, and (E) an alkoxysilane group or an alkoxysilane. Group, an epoxy resin composition for semiconductor encapsulation characterized by comprising a silicone oil having an alcoholic hydroxyl group and a polyether group as an essential component,
Particularly, the epoxy resin composition for semiconductor encapsulation, wherein the silicone oil of (E) is one or more silicone oils selected from the formulas (1), (2), (3) and (4). .

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[0006]

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[0007]

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[0008]

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[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The epoxy resin used in the present invention refers to all monomers, oligomers and polymers having an epoxy group. For example, bisphenol type epoxy compound, orthocresol novolak type epoxy resin, biphenyl type epoxy compound, phenol novolak type epoxy resin,
Examples include a triphenolmethane-type epoxy compound, an alkyl-modified triphenolmethane-type epoxy compound, a triazine nucleus-containing epoxy resin, a dicyclopentadiene-modified epoxy resin, and a stilbene-type epoxy compound. The melting point, softening point, and epoxy equivalent of the epoxy resin are not particularly limited. These may be used alone or as a mixture. It is desirable that these epoxy resins contain as little ionic impurities as chlorine ions and sodium ions for moisture resistance reliability.

The phenolic resin curing agent used in the present invention refers to all monomers, oligomers and polymers having a phenolic hydroxyl group. For example, a phenol novolak resin, a cresol novolak resin, a dicyclopentadiene-modified phenol resin, a xylylene-modified phenol resin, a triphenolmethane-type phenol compound, or the like can be used. The melting point, softening point, and hydroxyl equivalent of the phenol resin are not particularly limited. These may be used alone or as a mixture. It is desirable that these phenolic resins contain as little ionic impurities as chlorine ions and sodium ions for moisture resistance reliability.

The curing accelerator used in the present invention includes:
Any material that promotes the reaction between the epoxy group and the phenolic hydroxyl group may be used, and those generally used as a sealing material can be widely used. For example, 1,8-
Examples thereof include diazabicyclo (5,4,0) undecene-7, triphenylphosphine, tetraphenylphosphonium / tetraphenylborate, dimethylbenzylamine, and tetraphenylphosphonium / tetranaphthoic acid borate. These curing accelerators may be used alone or as a mixture. Also, these curing accelerators
It may be used by being melt-mixed in advance with a phenol resin or the like,
It may be simply mixed at the time of producing the resin composition.

The inorganic filler used in the present invention includes:
For example, fused silica powder, spherical silica powder, crystalline silica powder, secondary aggregated silica powder, porous silica powder, silica powder obtained by pulverizing secondary aggregated silica powder or porous silica powder, alumina and the like can be mentioned. The shape of the inorganic filler may be crushed or spherical. Further, these inorganic fillers may be used alone or in combination. In general, it is preferable to use spherical fused silica powder having an excellent balance of flow characteristics, mechanical strength, and thermal characteristics.

The silicone oil having an alkoxysilane group or an alkoxy group, an alcoholic hydroxyl group and a polyether group used in the present invention will be described in detail because it is an important technical point in the present invention. As described above, when the compounding amount of the inorganic filler is about 90% by weight in the whole resin composition, it is difficult to obtain a uniform resin composition by the conventional means. In order to solve these problems, in the present invention, a uniform resin composition is obtained by using a silicone oil having an alkoxysilane group or an alkoxy group, an alcoholic hydroxyl group and a polyether group (hereinafter, referred to as a surface treatment agent A). It is. The alkoxysilane group or alkoxy group in the surface treatment agent A used in the present invention is a functional group that chemically bonds to the surface of the inorganic filler, and the alcoholic hydroxyl group and the polyether group have excellent compatibility with the resin component. It is a functional group. In general, when only a silane coupling agent is used, the surface energy is small, so that it is not efficiently dispersed on the surface of the inorganic filler, and there is no sufficient effect for improving the conformation at the interface. On the other hand, when the surface treating agent A of the present invention is used, it is efficiently dispersed on the surface of the inorganic filler, and the effect of improving the conformation at the interface is sufficiently exerted.

As the surface treatment agent A, in particular, the formula (1):
What is shown by the structure of Formula (2), Formula (3), and Formula (4) is preferable. In formulas (1), (2), (3) and (4), the alkoxysilane group is more preferably methoxysilane or ethoxysilane, and the alkoxy group is more preferably methoxy or ethoxy. As the polyether group in the formulas (1), (2), (3) and (4), polyethylene oxide or polypropylene oxide, or a copolymer of polyethylene oxide and polypropylene oxide is preferable. Further, the average degree of polymerization N (N = n + a + b + c + 2) in the main chain of the silicone oil is 5
When ≦ N ≦ 300 and N is less than 5, a high proportion of silicone oil containing no alkoxysilane group or alkoxy group, no alcoholic hydroxyl group and no polyether group is present, and the reactivity to the inorganic filler and It is not preferable because the compatibility with the resin component is impaired and the number of voids in the molded product increases during molding. On the other hand, if it exceeds 300, it cannot be uniformly dispersed on the surface of the inorganic filler, so that the effect of improving adaptation to the resin is insufficient, and the effect of reducing voids is undesirably reduced.

The amount of the surface treatment agent A is determined by the amount of the inorganic filler 10
0.01 to 5 parts by weight with respect to 0 parts by weight is preferred. 0.
When it is less than 01, the effect of addition as a surface treatment agent is small, and the effect of reducing voids is small. If it exceeds 5 parts by weight, the water absorption increases, and the solder crack resistance is remarkably reduced. The silicone oil having an alkoxysilane group, an alcoholic hydroxyl group and a polyether group in the formula (1) or the silicone oil having an alkoxy group, an alcoholic hydroxyl group and a polyether group may be used alone or in combination. The same applies to the silicone oils of the formulas (2), (3) and (4). One or more silicone oils selected from the formulas (1), (2), (3) and (4) may be used as a mixture. Furthermore, the silicone oil represented by the formula (1), the formula (2), the formula (3) and the formula (4) and the silane coupling agent represented by the formula (5) and the formula (6) (hereinafter referred to as a surface treatment agent) B). The combined use improves the strength and solder crack resistance of the molded product. When used in combination, the ratio between the surface treatment agent A and the surface treatment agent B is not particularly limited, but the surface treatment agent A1
It is desirable that the amount of the surface treatment agent B be 1000 parts by weight or less based on 00 parts by weight. If it exceeds 1000 parts by weight, the water absorption increases,
Solder crack resistance is reduced. The method of adding the surface treatment agent A and the surface treatment agent B is not particularly limited. The reaction rate of the surface treating agent A or a mixture of the surface treating agent A and the surface treating agent B with the inorganic filler is not particularly limited.

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[0016]

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The resin composition of the present invention comprises the components (A) to (E) or the components (A) to (F) as essential components. Various additives such as a flame retardant such as antimony oxide and hexabromobenzene, a colorant such as carbon black and red iron, and a release agent may be appropriately blended. Further, the resin composition of the present invention comprises the components (A) to (E), or the components (A) to (F),
After sufficiently mixing the other additives uniformly using a mixer or the like, the mixture can be melt-kneaded with a hot roll or a kneader or the like, cooled, and pulverized, followed by production. These resin compositions can be applied to sealing, coating, insulating and the like of electronic parts or electric parts.

[0018]

The present invention will be described below by way of examples. The unit of the compounding ratio is parts by weight. Example 1 Biphenyl type epoxy compound (YX4000 H manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 195) 9.6 parts by weight Phenol aralkyl resin (XL-225LL manufactured by Mitsui Toatsu Chemicals, Inc., hydroxyl equivalent) 175) 7.4 parts by weight 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 0.2 part by weight Spherical silica (average particle diameter 20 μm) 79.8 parts by weight Silicone oil S- 1 0.2 part by weight Brominated phenol novolak type epoxy resin 1.0 part by weight Antimony trioxide 1.0 part by weight Carbon black 0.3 part by weight Carnauba wax 0.5 part by weight is mixed at room temperature with a mixer, The mixture was kneaded at 130 ° C. using a biaxial roll, cooled, pulverized, and tabletted to obtain a resin composition. This resin composition is molded using a low-pressure transfer molding machine (molding conditions: 175 ° C., 70 kg)
f / cm ² , 120 seconds).
It was post-cured in 8 hours and evaluated by the method shown below. Table 2 shows the results. Table 1 shows the structure of the silicone oil S-1. The basic structures of Formulas (1) to (4) in Table 1 are as described above.

Evaluation method Void: 160p using a low pressure transfer molding die
A QFP molding test was performed. Molding temperature 175 ° C, pressure 7
Observation of voids of the package molded at 0 kgf / cm ² and curing time of 120 seconds using an ultrasonic flaw detector.
The evaluation was made in three stages of x. Solder crack resistance: 175 ° C, pressure 70kgf / c
80pQFP (1.5mm m ^{2, and} the curing time 120 seconds
Thickness, chip size 9 × 9 mm) package was obtained.
Post-curing was performed at 5 ° C. for 8 hours to obtain eight packages. This package was left in a thermo-hygrostat at 85 ° C. and a relative humidity of 60% for 168 hours, and then subjected to an IR reflow process at 240 ° C. The peeling inside the package after the treatment was observed using an ultrasonic flaw detector, and the solder crack resistance was evaluated based on the number of cracked packages in the eight packages.

Examples 2 to 20, Comparative Examples 1 to 3 Resin compositions were prepared in the same manner as in Example 1 with the formulations shown in Tables 4 to 6, and evaluated in the same manner as in Example 1. Table 4 shows the results
To # 6. The structures of the silicone oils used in Examples 2 to 20 and Comparative Examples 1 to 3 are shown in Tables 1 to 3. The basic structures of Formulas (1) to (4) in Tables 1 to 3 are as described above. The silane coupling agents used in Examples 13 to 16 are represented by Formulas (7) to (10) below.

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[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

[Table 5]

[0026]

[Table 6]

[0027]

By using the resin composition of the present invention, it is possible to obtain a highly reliable semiconductor device having little void property and excellent solder crack resistance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/31

Claims (3)

[Claims] 1. An epoxy resin, (B) a phenolic resin curing agent, (C) a curing accelerator, (D) an inorganic filler, and (E) an alkoxysilane or alkoxy group, an alcoholic hydroxyl group and a polyether. An epoxy resin composition for semiconductor encapsulation, comprising a silicone oil having a group as an essential component. 2. An alkoxysilane group or an alkoxy group,
The epoxy for semiconductor encapsulation according to claim 1, wherein the silicone oil having an alcoholic hydroxyl group and a polyether group is at least one selected from formulas (1), (2), (3) and (4). Resin composition. Embedded image Embedded image Embedded image Embedded image 3. An epoxy resin, (B) a phenol resin curing agent, (C) a curing accelerator, (D) an inorganic filler,
(E) a silicone oil having at least one alkoxysilane or alkoxy group selected from formulas (1), (2), (3) and (4), an alcoholic hydroxyl group and a polyether group, and F) An epoxy resin composition for semiconductor encapsulation, comprising at least one silane coupling agent selected from formulas (5) and (6) as an essential component. Embedded image Embedded image