JPH10292095A - Epoxy resin composition and semiconductor sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin compsn. excellent in moldability and resistances to moisture and soldering heat by compounding a bisphenol epoxy resin, a phenol resin, an epoxidized silane coupling agent contg. a minute amt. of an org. base, a specified amt. of a fused silica powder having a specified max. particle size, and a cure accelerator as the essential ingredients. SOLUTION: An epoxy resin represented by the formula is used. A phenol resin having at least two phenolic hydroxyl groups is used. A silane coupling agent represented by the formula: R<1> Cn H2n Si(OR<2> )2 (wherein R<1> is an epoxidized group; R<2> is methyl or ethyl; and (n) is 0 or 1) is used. The org. base is contained pref. in an amt. of 0.05-5 wt.% in the coupling agent. A fused silica powder having a max. particle size of 100 μm or lower is used in an amt. of 25-90 wt.% of the compsn.

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 excellent in moisture resistance, solder heat resistance, and moldability, and a semiconductor sealing device.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductor integrated circuits,
At the same time as the development of high integration and high reliability technologies, automation of the mounting process of semiconductor devices has been promoted. For example, when a flat package type semiconductor device is mounted on a circuit board, soldering has conventionally been performed for each lead pin, but recently, a solder immersion method or a solder reflow method has been adopted.

[0003]

A semiconductor device sealed with a resin composition comprising a conventional epoxy resin such as a novolak type epoxy resin, a novolak type phenol resin and an inorganic filler is subjected to solder bath immersion of the entire device. There is a disadvantage that the moisture resistance is reduced. In particular, when a semiconductor device that has absorbed moisture is immersed, peeling between the sealing resin and the semiconductor chip, or between the sealing resin and the lead frame, and cracking of the internal resin occur, causing significant deterioration in moisture resistance, causing disconnection and moisture due to electrode corrosion. The semiconductor device has a drawback that long-term reliability cannot be guaranteed.

[0004] Further, by filling the inorganic filler at a high level, the proportion of the resin component is reduced, and the resin composition can be made to have a low moisture absorption. There is a drawback that the internal resin crack propagates along the interface to the external resin crack because the interface between the inorganic filler and the inorganic filler increases.

The present invention has been made to solve the above-mentioned drawbacks, and has a small influence of moisture absorption. In particular, it has excellent moisture resistance after solder bath immersion, excellent solder heat resistance, moldability, fluidity, and a sealing resin. Epoxy resin composition that guarantees long-term reliability without peeling between semiconductor chip or encapsulation resin and lead frame, no internal resin cracks, no disconnection due to electrode corrosion, and no leak current due to moisture An object and a semiconductor sealing device are provided.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, by using a specific epoxy resin and a specific silane coupling agent, moisture resistance and solder heat resistance have been improved. It has been found that a resin composition having excellent properties and moldability can be obtained, and the present invention has been completed.

That is, the present invention provides (A) an epoxy resin represented by the following structural formula:

[0008]

Embedded image (B) a phenolic resin, (C) a silane coupling agent having an epoxy group represented by the following general formula and containing a trace amount of an organic base,

[0009]

Embedded image ^{_{R 1 -C n H 2n -Si (}} OR 2) 3 ( wherein R ¹ is an atomic group having an epoxy group, R ²
Represents a methyl group or an ethyl group, and n represents an integer of 0 or 1 or more.) (D) A fused silica powder having a maximum particle size of 100 μm or less and (E) a curing accelerator are essential components, and the entire resin composition An epoxy resin composition comprising the fused silica powder (D) in an amount of 25 to 90% by weight based on the weight of the epoxy resin composition. A semiconductor sealing device is characterized in that a semiconductor chip is sealed with a cured product of the epoxy resin composition.

Hereinafter, the present invention will be described in detail.

As the epoxy resin (A) used in the present invention, those represented by the above structural formula (5) are used. In addition, a novolak epoxy resin, an epibis epoxy resin, and other known epoxy resins can be used in combination with the epoxy resin.

The phenolic resin (B) used in the present invention is not particularly limited as long as it has two or more phenolic hydroxyl groups capable of reacting with the epoxy group of the epoxy resin (A). As a specific compound, for example,

[0013]

Embedded image (However, n represents 0 or an integer of 1 or more)

[0014]

Embedded image (However, n represents 0 or an integer of 1 or more)

[0015]

Embedded image (However, n represents 0 or an integer of 1 or more)

[0016]

Embedded image (However, n represents 0 or an integer of 1 or more)

[0017]

Embedded image (Where n represents 0 or an integer of 1 or more), and these can be used alone or in combination.

As the silane coupling agent having an epoxy group (C) used in the present invention, those represented by the above-mentioned general formula (6) are used. Specifically, for example,

[0019]

Embedded image

[0020]

Embedded image And the like, and these can be used alone or as a mixture.

It is important to add a very small amount of an organic base to the silane coupling agent. Hydrolysis can be enhanced by treating with an organic base.
Examples of the organic base to be treated here include cyclic organic bases such as dimethylamine, diethylamine, pyridine, quinoline and piperidine, and these can be used alone or as a mixture of two or more. The compounding ratio of the organic base is desirably used within the range of 0.05 to 5% by weight based on the silane coupling agent. If the amount is less than 0.05% by weight, the hydrolysis of the silane coupling agent cannot be sufficiently promoted, and if it exceeds 5% by weight, the moisture resistance reliability is undesirably lowered.

As the fused silica powder (D) used in the present invention, a fused silica powder having a low impurity concentration, a maximum particle size of 100 μm or less and an average particle size of 30 μm or less is preferably used. If the average particle size exceeds 30 μm, the moisture resistance and the moldability are poor, which is not preferable. The compounding ratio of the fused silica powder is preferably 25 to 90% by weight based on the entire resin composition. If the proportion is less than 25% by weight, the resin composition has a high hygroscopicity, is inferior in moisture resistance after solder immersion, and
If it exceeds 90% by weight, the fluidity becomes extremely poor and the moldability is poor, which is not preferred. When an organic base is added to these fused silica powders as a silane coupling agent and immediately treated with a Henschel mixer, a super mixer, or the like, the surface can be uniformly treated, and the effect can be sufficiently exhibited.

The (E) curing accelerator used in the present invention includes a phosphorus-based curing accelerator, an imidazole-based curing accelerator, and D
BU-based curing accelerators and other curing accelerators can be widely used. These can be used alone or in combination of two or more. It is desirable that the curing accelerator is blended so as to contain 0.01 to 5% by weight based on the whole resin composition. If the proportion is less than 0.01% by weight, the gel time of the resin composition will be long and the curing properties will be poor. If it exceeds 5% by weight, the fluidity will be extremely poor and the moldability will be poor.
Further, the electrical properties are also poor, and the moisture resistance is poor, which is not preferable.

The epoxy resin composition of the present invention contains the above-mentioned specific epoxy resin, phenol resin, specific silane coupling agent, fused silica powder, and curing accelerator as essential components, but does not violate the object of the present invention. At the limit,
If necessary, for example, natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters,
A release agent such as paraffin, a flame retardant such as antimony trioxide, a coloring agent such as carbon black, a rubber-based or silicone-based low-stress imparting agent, and the like can be appropriately added and blended.

A general method for preparing the epoxy resin composition of the present invention as a molding material is to blend a specific silane coupling agent and an organic base into a fused silica powder, perform a surface treatment, and apply the above-mentioned specific epoxy resin. , Phenolic resin,
After blending the fused silica powder treated with the silane coupling agent, the curing accelerator, and other components and mixing them sufficiently uniformly using a mixer, etc., they are further melt-mixed using a hot roll or mixed using a kneader, and then cooled and solidified. And pulverized to an appropriate size to obtain a molding material. If the molding material thus obtained is applied to sealing, coating, insulating, etc. of electronic parts or electric parts such as semiconductor devices, excellent properties and reliability can be imparted.

The semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor chip using the molding material described above. The semiconductor chip to be sealed is not particularly limited to, for example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like. The most common sealing method is a low pressure transfer molding method, but sealing by injection molding, compression molding, casting, or the like is also possible. After sealing with a molding material, it is heated and cured, and finally a semiconductor sealing device sealed with this cured product is obtained. The curing by heating is desirably performed by heating to 150 ° C. or more.

[0027]

The epoxy resin composition and the semiconductor encapsulation device of the present invention use a specific epoxy resin, a phenol resin, a specific silane coupling agent, a fused silica powder and a curing accelerator to obtain a water absorbing property of the resin composition. This improves moldability, fluidity, thermomechanical properties and low stress, eliminates resin cracks after solder immersion and solder reflow, and reduces moisture resistance deterioration.

[0028]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, “%” means “% by weight”.

Example 1 84% of a fused silica powder (maximum particle size of 100 μm or less) was put into a Henschel mixer, and 0.4% of the above-mentioned silane coupling agent of Chemical Formula 12 and 4 × 10 ^{-4 of} diethylamine were stirred with stirring.
% Of the surface of the fused silica powder. Next, 6.4% of the bisphenol-based epoxy resin of the above formula 5, 1.5% of a tetrabromobisphenol A type epoxy resin, 1.4% of the phenol novolak resin of the above formula 7, 3.4% of the phenol aralkyl resin of the above formula 8, and 0.2 of triphenylphosphine %, Carnauba waxes 0.4%, carbon black 0.3% and antimony trioxide 2.0% were mixed at room temperature, kneaded and cooled at 90-100 ° C., and pulverized to produce a molding material (A).

Example 2 84% of a fused silica powder (maximum particle diameter of 100 μm or less) was put into a Henschel mixer, and 0.4% of the above-mentioned silane coupling agent of Chemical Formula 12 and 4 × 10 ^{-4 of} diethylamine were stirred with stirring.
% Of the surface of the fused silica powder. Next, 6.4% of the bisphenol-based epoxy resin of the above formula 5, 1.5% of a tetrabromobisphenol A type epoxy resin, 1.4% of the phenol novolak resin of the above formula 7, 3.4% of the dicyclopentadiene phenol resin of the above formula 9, and triphenyl Phosphine 0.2%, carnauba wax 0.4
%, Carbon black 0.3%, and antimony trioxide
2.0% was mixed at room temperature, kneaded and cooled at 90-100 ° C, and then pulverized to produce a molding material (B).

Example 3 84% of a fused silica powder (maximum particle diameter of 100 μm or less) was put into a Henschel mixer, and 0.4% of the above-mentioned silane coupling agent of Chemical Formula 13 and 4 × 10 ^{-4 of} diethylamine were stirred with stirring.
% Of the surface of the fused silica powder. Next, 6.4% of the bisphenol-based epoxy resin of the above formula 5, 1.5% of a tetrabromobisphenol A type epoxy resin, 1.4% of the phenol novolak resin of the above formula 7, 3.4% of the phenol aralkyl resin of the above formula 8, and 0.2 of triphenylphosphine %, Carnauba waxes 0.4%, carbon black 0.3%, and antimony trioxide 2.0% were mixed at room temperature, kneaded and cooled at 90-100 ° C, and pulverized to obtain a molding material (C).

COMPARATIVE EXAMPLE 1 80% of fused silica powder (maximum particle size 100 μm or less) was put into a Henschel mixer, and 0.4% of the above-mentioned silane coupling agent of Chemical formula 12 was added thereto with stirring to subject the fused silica powder to a surface treatment. . Next, 2.0% of tetrabromobisphenol A type epoxy resin, 8.1% of o-cresol novolak type epoxy resin, and the above-mentioned phenol novolak resin of formula 7
2.0%, phenol aralkyl resin 4.6
%, Triphenylphosphine 0.2%, carnauba waxes 0.4%, carbon black 0.3%, and antimony trioxide 2.0% are mixed at room temperature, kneaded and cooled at 90-100 ° C, and then ground to form a molding material (D). Was manufactured.

Comparative Example 2 84% of a fused silica powder (maximum particle size of 100 μm or less) was put into a Henschel mixer, and 0.4% of the above-mentioned silane coupling agent of Chemical Formula 12 was added thereto with stirring to subject the fused silica powder to a surface treatment. . Next, 1.5% of tetrabromobisphenol A type epoxy resin, 6.2% of o-cresol novolak type epoxy resin, and phenol novolak resin
1.5%, 3.5 phenol aralkyl resin of the above formula
%, Triphenylphosphine 0.2%, carnauba waxes 0.4%, carbon black 0.3% and antimony trioxide 2.0% are mixed at room temperature, kneaded and cooled at 90-100 ° C, and then ground to form a molding material (E). Was manufactured.

Comparative Example 3 84% of a fused silica powder (maximum particle size of 100 μm or less) was put into a Henschel mixer, and 0.4% of the above-mentioned silane coupling agent of Chemical formula 12 was added thereto with stirring to subject the fused silica powder to a surface treatment. . Next, 6.2% of the above-mentioned biphenyl type epoxy resin of the chemical formula 5, 1.5% of the tetrabromobisphenol A type epoxy resin, 1.5% of the phenol novolak resin of the above chemical formula 7, and the phenol aralkyl resin of the above chemical formula 3.
5%, triphenylphosphine 0.2%, carnauba waxes 0.4%, carbon black 0.3% and antimony trioxide 2.0% were mixed at room temperature, kneaded and cooled at 90-100 ° C, and then ground to form a molding material (F ) Manufactured.

The molding materials (A) to (F) thus produced
Was transferred into a mold heated to 170 ° C., and the semiconductor chip was sealed and cured to manufacture a semiconductor sealing device. Various tests were conducted on these semiconductor sealing devices, and the results are shown in Table 1. The epoxy resin composition and the semiconductor sealing device of the present invention have excellent water absorption, solder heat resistance, and moldability. Thus, a remarkable effect of the present invention could be confirmed.

[0036]

[Table 1] * 1: Spiral flow measurement (175 ° C.) according to EMMI-I-66. * 2: Koka type flow viscosity (175 ° C). * 3: A molded product (specimen) obtained by transfer molding at 175 ° C, 80 kg / cm ² for 2 minutes is prepared, post-cured at 175 ° C for 8 hours, and tested according to JIS-K-6911. did. * 4: A molded article similar to * 3 was prepared, post-cured at 175 ° C for 8 hours, a test piece of appropriate size was measured using a thermomechanical analyzer. * 5, * 6: 5.3 × 5.3 mm chip is placed in a VQFP (12 × 12 × 1.4 mm thick) package, transfer molded at 175 ° C for 2 minutes using molding materials, and after 175 ° C for 8 hours. Curing was performed. The semiconductor encapsulation device thus obtained was subjected to a moisture absorption treatment at 85 ° C. and 85% for 48 hours, and then calculated based on the increased weight. In addition, this was passed through an air reflow machine (Max 240 ° C) to check for external and internal cracks.

[0037]

As is apparent from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulation device of the present invention are excellent in moisture resistance, solder heat resistance, moldability, and filling of thin packages and the like. It is also excellent in performance, is less affected by moisture absorption, can significantly reduce disconnection due to electrode corrosion, generation of leak current due to moisture, and the like, and can guarantee reliability for a long period of time.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 61/06 C08L 61/06 H01L 23/29 H01L 23/30 R 23/31

Claims (2)

[Claims] (A) an epoxy resin represented by the following structural formula: (B) a phenolic resin, (C) a silane coupling agent having an epoxy group and having an extremely small amount of an organic base and having an epoxy group represented by the following general formula: R ¹ -C _n H _2n -Si (OR ² ) ₃ (wherein, R ¹ represents an atomic group having an epoxy group, R ²
Represents a methyl group or an ethyl group, and n represents an integer of 0 or an integer of 1 or more.) (D) Fused silica powder having a maximum particle size of 100 μm or less and (E) a curing accelerator as essential components; An epoxy resin composition comprising the fused silica powder of (D) in a proportion of 25 to 90% by weight based on the composition. (A) an epoxy resin represented by the following structural formula: (B) a phenolic resin, (C) a silane coupling agent having an epoxy group and having an extremely small amount of an organic base and having an epoxy group represented by the following formula: R ¹ -C _n H _2n -Si (OR ² ) ₃ (wherein, R ¹ represents an atomic group having an epoxy group, R ²
Represents a methyl group or an ethyl group, and n represents an integer of 0 or 1 or more.) (D) A fused silica powder having a maximum particle size of 100 μm or less and (E) a curing accelerator are essential components, and the entire resin composition A semiconductor sealing device, wherein a semiconductor chip is sealed with a cured product of an epoxy resin composition containing the fused silica powder of (D) in a ratio of 25 to 90% by weight based on a product.