JP2671727B2 - Surface-treated silica, method for producing the same, and filler for resin composition for semiconductor encapsulation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a surface-treated silica which can be suitably used as a component for imparting mechanical strength to a composite material such as a resin composition for encapsulating a semiconductor device, a method for producing the same and a surface-treated silica thereof. The present invention relates to a filler for a semiconductor encapsulating resin composition.

[0002]

2. Description of the Related Art
Semiconductor elements such as transistors, ICs, and LSIs are usually sealed with ceramic packages, plastic packages, or the like to be semiconductor devices. In the above ceramic package, the constituent material itself has heat resistance, and
Since it is also excellent in penetration resistance, it is strong against temperature and humidity, and because it is a hollow package, it has high mechanical strength and enables highly reliable sealing.

However, since the constituent material of the ceramic package is relatively expensive and there is a problem in that it is inferior in mass productivity, recently, resin sealing using a plastic package has become mainstream. An epoxy resin composition is mainly used for this resin encapsulation because of its excellent properties. However, technological innovations in the semiconductor field have improved the degree of integration of semiconductor devices, increased the size of elements and miniaturized wiring, and have tended to make packages smaller and thinner. Higher reliability than conventional materials (low stress, moisture resistance reliability,
Improvement of impact resistance, heat resistance, and crack resistance) is required. In order to meet this demand, it has been studied to reduce the thermal stress by modifying the sealing resin with rubber and to increase the amount of the inorganic filler, but few give sufficient reliability to the composite material. Therefore, there is a strong demand for development of a technique capable of improving the reliability in order to cope with the increase in the element size described above.

[0004] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide surface silica that can be suitably used as an inorganic filler to be mixed with a composite material such as a resin composition for encapsulating a semiconductor device, and a production method for obtaining this surface-treated silica.

[0005]

Means and Actions for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor found that the functional group was 1
Silica is mixed with at least one silane coupling agent and stirred to coat the surface of the silica particles with the silane coupling agent, and the silica particles coated with the silane coupling agent are treated with a functional group capable of reacting with the functional group. By mixing and stirring one or more organic compounds and further coating the above-mentioned silica particles with the above-mentioned organic compounds, silica having desired characteristics can be obtained. Further, this surface-treated silica is used as an epoxy resin for semiconductor encapsulation. When compounded into a composite material such as a composition as an inorganic filler, the affinity between the inorganic filler, silica, and the resin matrix is strengthened, resulting in low stress and excellent impact resistance, moisture resistance reliability, and crack resistance. The inventors have found that a cured product can be obtained, and are particularly useful as a filler for a resin composition for semiconductor encapsulation, and have completed the present invention.

The present invention will be described in more detail below. In the surface-treated silica of the present invention, the surface of silica particles is coated with a silane coupling agent having one or more functional groups, and the functional group capable of reacting with the functional groups is further reacted. It is formed by coating with an organic compound having one or more groups.

The type and shape of the above-mentioned surface-treated silica are not particularly limited, and specific examples thereof include fused silica and crystalline silica. The particle size is also not limited, but when used as a filler for the resin composition for semiconductor encapsulation, the average particle size is preferably 5 to 70 μm.

As the silane coupling agent having one or more functional groups used for the above-mentioned silica coupling, known silane coupling agents can be used. For example, γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropylmethyl. Diethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N
-Β- (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, vinylsilylethoxysilane, tri Methoxysilylpropyl nadic acid anhydride and the like can be mentioned.

On the other hand, examples of the organic compound having at least one functional group capable of reacting with the functional group of the silane coupling agent include those having the functional groups shown below, but the functional groups are not limited to these. is not.

[0010]

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Examples of organic compounds having one or more such functional groups include the compounds shown below.
The seeds may be used alone or in combination of two or more.

[0012]

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In order to obtain the surface-treated silica of the present invention, first, the above-mentioned silane coupling agent having one or more functional groups is mixed with silica and stirred, and the surface of silica particles is coated with the above-mentioned silane coupling agent. . In this case, the compounding amount of the silane coupling is preferably 0.01 to 10 parts, particularly 0.1 to 2 parts with respect to 100 parts of silica (parts by weight, the same applies hereinafter).

When the silica and the silane coupling agent are mixed and stirred, in order to strengthen the bond between the silane coupling agent and the silanol group existing on the surface of the silica, a suitable mixture should be prepared before mixing and stirring with the silane coupling agent. It is preferable to perform heat treatment at a temperature for a long time or heat treatment at a high temperature. In this case, it is preferable that the thermal formation temperature is 20 to 50 ° C. for 10 to 50 hours, and the heat treatment is 50 to 200 ° C. for 1 to 8 hours.

The above coating treatment may be carried out in a solvent-free system (dry process), in a solvent (wet process), in a solvent-free system, and then in a solvent. Most preferably, the reaction is carried out in a solvent such as alcohol, alcohol or toluene. In the dry treatment, the surface treatment is carried out using a high-speed stirring device such as Henschel, and in the wet treatment, the solvent and silica are put in a container such as a flask and the coupling agent is added with stirring to carry out the surface treatment. Further, in this coating treatment, silica was kept at 70 to 130 ° C., a silane coupling agent was added while stirring with a stirrer, and the temperature was further adjusted to 70 ° C.
A method such as stirring at ˜130 ° C. for 1 to 5 hours can be adopted. In this case, it is preferable to use a catalyst such as diazabicycloundecene.

In order to further coat the surface of the silica particles whose surface is coated with the silane coupling agent in this way with an organic compound having at least one functional group capable of reacting with the functional group of the silane coupling agent, Preferably temperature 25-1
While maintaining the temperature at 20 ° C., add the above organic compound, and
A method of continuing stirring for a time can be adopted. Also in this case, it is preferable to use a catalyst such as diazabicycloundecene as in the case of mixing with the silane coupling agent.

The ratio of the silane coupling agent to the organic compound is such that the equivalent amount of the silane coupling agent is A,
When the equivalent weight of the organic compound is B, 0.01 ≦ B / A
It is preferable that ≦ 2, especially 0.04 ≦ B / A ≦ 1.2. If this value is less than 0.01, the effect of the above organic compound may not be exhibited due to the large number of functional groups of the above-mentioned unreacted silane coupling agent, and if it exceeds 2, the above-mentioned unreacted organic compound remains. Therefore, when the surface-treated silica is mixed in the composite material, it may adversely affect the resin component.

After the organic solvent is distilled off under reduced pressure from the reaction product treated with the silane coupling agent and the organic compound as described above, the desired surface-treated silica can be obtained. .

When the surface-treated silica of the present invention is mixed with various resin compositions such as conventionally known molding materials and encapsulating materials and the compositions are cured, they have low stress and impact resistance and moisture resistance. A cured product excellent in heat resistance reliability and crack resistance can be provided. Therefore, the surface-treated silica of the present invention is suitably used as a filler for the resin composition for semiconductor encapsulation. In this case, the amount of the surface-treated silica is preferably 100 to 450 parts with respect to 100 parts of the resin.

When the surface-treated silica of the present invention is used as a filler for a composite material, the other components of the composition may have the same composition as the conventionally known composite material component.

[0021]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Example 1] Reflux condenser,
3 kg of silica (average particle size 30 μm) and 2 kg of toluene as a solvent were placed in a four-necked flask having an internal volume of 5 liter equipped with a stirrer and a dropping funnel, and azeotropic dehydration was carried out for 2 hours, and then 112 ° C. while stirring with a stirrer. 15 g of an epoxy group-containing silane coupling agent (γ-glycidoxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd., KBM403) was added dropwise at the temperature of 20 ° C. for 20 minutes and further stirred at the same temperature for 3 hours. Then, while continuing stirring, 7 g of para-aminophenol was added at the same temperature, and stirring was further continued at the same temperature for 3 hours. The solvent was distilled off from the thus obtained reaction product under reduced pressure, followed by drying at 150 ° C. for 4 hours to obtain 3 kg of surface-treated silica.

The surface-treated silica (inorganic filler) and other encapsulating resin components were mixed in a blending ratio shown in Table 1 and melt-kneaded using a Buscon Kneader to produce an epoxy resin composition. Using this epoxy resin composition, a test piece for glass transition temperature (test piece having a diameter of 4 mm and a length of 15 mm), a disk having a diameter of 70 mm, and a semiconductor chip for reliability evaluation, respectively, at 175 ° C., 70 kg / cm ² , molding time. Transfer molding was carried out under the condition of 2 minutes and cured at 180 ° C. for 4 hours to obtain molded products for various reliability evaluation tests.
The thermal shock resistance and crack resistance were evaluated by the following reliability evaluation test methods. Table 2 shows the results.

(Reliability Evaluation Test Method) The glass transition temperature was measured by increasing the temperature of the heat-resistant reliability test piece by 5 ° C. per minute by the TMA method (thermomechanical analysis method). Thermal shock resistance After each sample was heated to 180 ° C. in a constant temperature bath, a destructive test under heat was performed by an impact tester, and the total absorbed energy until the sample was broken was evaluated. Crack resistance Each sample is left in an atmosphere of 121 ° C and 100% RH for 100 hours to absorb moisture, and then placed in a solder bath at a temperature of 240 ° C for 30 hours.
A dipping test was conducted for 2 seconds, and the number of package cracks generated was evaluated.

Example 2 3 kg of silica (average particle size 30 μm) and an amino group-containing silane coupling agent (N-β (aminoethyl) γ-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., were added to a Henschel mixer. KB
After adding 15 g of M603) and mixing for 15 minutes, 120
It heat-processed at 4 degreeC. This was transferred to a four-necked flask similar to that used in Example 1, and 1 kg of toluene was used as a solvent.
And 1 kg of methyl isobutyl ketone are added, and an organic compound YX represented by the following formula at a temperature of 112 ° C. while stirring with a stirrer
22.4 g of 4000H (produced by Yuka Shell Epoxy Co., Ltd.) was added, and stirring was continued at the same temperature for 3 hours. The solvent was distilled off from the reaction product thus obtained under reduced pressure, and then 1
It was dried at 20 ° C. for 4 hours to obtain 3 kg of surface-treated silica.

[0026]

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The surface-treated silica thus obtained and other sealing components were mixed in the mixing ratio shown in Table 1 by the same method as in Example 1 to produce an epoxy resin composition. A similar test piece was prepared and a similar reliability evaluation test was performed. The results are also shown in Table 2.

Example 3 3 kg of silica (average particle size 30 μm) and 15 g of epoxy group-containing silane coupling agent (KBM403) were placed in a Henschel mixer and mixed for 15 minutes, and then a diamine BAPPHG (2, represented by the following formula:
2-bis [4- (4-aminophenoxy p-phenyl]
26.2 g of propane) was added and mixed for another 15 minutes.
The thus obtained product was dried at 120 ° C. for 4 hours to obtain 3 kg of surface silica.

[0029]

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The surface-treated silica thus obtained and other sealing components were mixed in the mixing ratios shown in Table 1 in the same manner as in Example 1, and a test piece similar to that in Example 1 was prepared. The reliability evaluation test was performed. The results are also shown in Table 2.

Example 4 3 kg of silica (average particle size 30 μm) and 2 kg of xylene were placed in a four-necked flask similar to that used in Example 1, and the mixture was stirred at 120 ° C. with a stirrer.
15 g of the acid anhydride-containing silane coupling agent represented by the following formula was added dropwise over 20 minutes at a temperature of the dropping funnel and stirred for 3 hours at the same temperature, and then the diamine used in Example 3 was added while continuing stirring. 18.9g was added, and further at 150 ° C for 6
After drying for 3 hours, 3 kg of surface-treated silica was obtained.

[0032]

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An epoxy resin composition was prepared by mixing the surface-treated silica thus obtained with other sealing components in the same proportions as shown in Table 1 in the same manner as in Example 1.
The same test piece as in Example 1 was prepared and the same reliability evaluation test was performed. The results are also shown in Table 2.

[Comparative Example 1] Untreated silica and other sealing resin components were mixed in the proportions shown in Table 1 in the same manner as in Example 1 to produce an epoxy resin composition, which was the same as in Example 1. A reliability evaluation test was conducted.

[Comparative Example 2] 3 kg of silica and 2 kg of toluene were placed in the same four-necked flask as used in Example 1 and subjected to azeotropic dehydration for 2 hours, and then stirred with a stirrer 11
Epoxy group-containing silane coupling agent with a dropping funnel at a temperature of 2 ° C (Shin-Etsu Chemical Co., Ltd., KBM403)
15 g was added dropwise over 20 minutes, and the mixture was further stirred at the same temperature for 3 hours.

The surface-treated silica thus obtained and other sealing components were mixed in the mixing ratio shown in Table 1 in the same manner as in Example 1 to produce an epoxy resin composition, which was the same as in Example 1. Then, the same reliability evaluation test was performed. The results are also shown in Table 2.

[0037]

[Table 1] * All units are parts by weight

[0038]

[Table 2]

[0039]

EFFECTS OF THE INVENTION According to the present invention, surface-treated silica suitable as a filler for composite materials can be easily and efficiently produced. When this surface-treated silica is compounded with a resin composition, low stress and moisture resistance can be obtained. It gives a cured product with excellent reliability, impact resistance, and heat resistance. Therefore, the silica of the present invention is useful as a filler for a resin composition for semiconductor encapsulation.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takayuki Aoki, No. 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Inside the Silicon Materials Research Laboratory (72) Inventor Shigeki Ino Usui, Gunma Prefecture Gunji, Matsuida-machi, 1-person, Hitomi, Shin-Etsu Chemical Co., Ltd., Silicon Materials Research Laboratory (72) Inventor, Yukiko Wakao, Hitsumi, Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Co., Ltd., Silicon Electronic Materials Research Center

Claims (3)

(57) [Claims] 1. A method comprising coating the surface of silica particles with a silane coupling agent having one or more functional groups, and further coating with an organic compound having one or more functional groups capable of reacting with the above functional groups. Surface treated silica. 2. A silane coupling agent having one or more functional groups and silica are mixed and stirred to coat the surface of the silica particle with the silane coupling agent, and the silica particle coated with the silane coupling agent is treated as described above. A method for producing surface-treated silica, which comprises mixing and stirring an organic compound having one or more functional groups capable of reacting with a functional group, and further coating the silica particles with the organic compound. 3. A filler for a resin composition for semiconductor encapsulation, which comprises the surface-treated silica according to claim 1.