JPH10231355A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition effective for decreasing the generation of voids in a molded article in molding and improving the soldering crack resistance by adding a specific silicone oil to an epoxy resin composition. SOLUTION: This epoxy resin composition contains, as essential components, (A) an epoxy resin (e.g. a biphenyl-type epoxy compound), (B) a phenolic resin curing agent (e.g. a phenolic novolac resin), (C) a cure accelerator [e.g. 1,8- diazabicyclo(5,4,0)undecene-7], (D) an inorganic filler (e.g. spherical silica powder) and (E) a silicone oil having alkoxysilane group or alkoxy group, epoxy group and polyether group. The silicone oil E is especially preferably expressed by the formula I [(n), (a), (b) and (C) are each >=1; 5<=n+a+b+c+2(=N)<=300; A is a group of the formula II (1<=x<=3; R1 is a 1-3C alkylene; R2 and R3 are each CH3 , etc.); B is a group of the formula III; C is a group of the formula IV (d+e>=1); R4 is a 1-30C alkylene, etc.; R5 is a 1-5C alkyl], the formula V, the formula VI, etc.

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 moisture absorption especially for the above 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 group, and an epoxy resin composition for semiconductor encapsulation characterized by having a silicone oil having a polyether group as an essential component,
The epoxy resin composition for semiconductor encapsulation wherein the silicone oil of (E) is at least one silicone oil 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, biphenyl type epoxy compound, stilbene type epoxy compound,
Orthocresol novolak epoxy resin, phenol novolak epoxy resin, triphenolmethane epoxy resin, alkyl-modified triphenolmethane epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene-modified epoxy resin, and the like. 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 resin, or the like can be used. Melting point, softening point,
The hydroxyl group equivalent is 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,
They may be simply mixed during the production of 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 or alkoxy group, an epoxy 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, the content of the inorganic filler is 90% by weight in the total resin composition.
In such a case, it is becoming difficult to obtain a uniform resin composition by 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 epoxy group, and a polyether group (hereinafter, referred to as a surface treatment agent A). It is. The alkoxysilane group or the alkoxy group in the surface treatment agent A used in the present invention is a functional group chemically bonded to the surface of the inorganic filler, and the epoxy group and the polyether group have excellent compatibility with the resin component. Things. 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 preferably methoxysilane or ethoxysilane, and the alkoxy group is more preferably methoxy or ethoxy. The epoxy group in the formulas (1), (2), (3) and (4) preferably has a structure of B in the structural formula, and the polyether group includes polyethylene oxide or Polypropylene oxide, and more preferably a copolymer of polyethylene oxide and polypropylene oxide, is preferred. Further, the average degree of polymerization N in the main chain of the silicone oil (N = n
+ A + b + c + 2) is 5 ≦ N ≦ 300, and if N is less than 5, a high proportion of silicone oil containing no alkoxysilane group or alkoxy group, epoxy group and polyether group is present, and inorganic filler This is not preferred because the reactivity with the resin and the compatibility with the resin component are impaired, and voids in the molded article increase 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 compatibility with the resin component 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 the amount exceeds 5 parts by weight, the moisture absorption rate increases, and the solder crack resistance remarkably decreases. The silicone oil having an alkoxysilane group, an epoxy group, and a polyether group in the formula (1) or the silicone oil having an alkoxy group, an epoxy group, and a polyether group may be used alone or as a mixture. 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. Further, equation (1),
Using the silicone oils represented by the formulas (2), (3) and (4) in combination with the silane coupling agents represented by the formulas (5) and (6) (hereinafter referred to as surface treatment agent B) May be. The combined use improves the strength and solder crack resistance of the molded product. When used in combination, surface treatment agent A
The ratio between the surface treatment agent B and the surface treatment agent B is not particularly limited, but the surface treatment agent B is desirably 1,000 parts by weight or less based on 100 parts by weight of the surface treatment agent A. If it exceeds 1000 parts by weight, the moisture absorption rate tends to increase, and the solder crack resistance tends to decrease. 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 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) 79.5 parts by weight Silicone oil S- 1 0.5 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 was mixed at room temperature using a mixer, The mixture was kneaded at 50 to 130 ° C. using a biaxial roll, cooled, pulverized, and tabletted to obtain a resin composition. This resin composition was evaluated by the following method. Table 4 shows the results. Silicone oil S
Table 1 shows the structure of -1. Equations (1) to (4) in Table 1
Is 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 cracking resistance: Using a low-pressure transfer molding die, a package of 80 pQFP (1.5 mm thick, chip size 9 × 9 mm) was molded at a molding temperature of 175 ° C., a pressure of 70 kgf / cm ² , and a curing time of 120 seconds. After curing for 8 hours, 8 packages were obtained. Place this package in a thermo-hygrostat at 85 ° C and 60% relative humidity.
After standing for 68 hours, an IR reflow treatment at 240 ° C. was performed. 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 21 and Comparative Examples 1 to 4 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. Tables 1 to 3 show the structures of the silicone oils used in Examples 2 to 21 and Comparative Examples 1 to 3. The basic structures of Formulas (1) to (4) in Tables 1 to 3 are as described above. The structures of (I) to (V) in Tables 1 to 3 are shown below. The silane coupling agents used in Examples 14 to 17 are shown in the following formulas (7) to (10). The silicone oil S-17 used in Comparative Example 4 is shown in the following formula (S-17).

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

[Table 5]

[0025]

[Table 6]

[0026]

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[0027]

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[0028]

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[0029]

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.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 83/06 C08L 83/06 H01L 23/29 H01L 23/30 R 23/31

Claims (3)

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