JPH08198941A - Epoxy resin composition and device for sealing semiconductor - Google Patents

Abstract

PURPOSE: To obtain an epoxy resin composition having excellent water vapor resistance and solder heat resistance and thermal conductivity, comprising a specific epoxy resin, a phenol resin, a specific silane coupling agent, a specific ratio of chamfered crystal silica powder and a curing promoter as essential components. CONSTITUTION: This composition comprises (A) an epoxy resin of formula I [(n) is an integer of 0 or >=1), (B) a phenol resin, (C) a silane coupling agent containing an epoxy of the formula R<1> -Cn H2n -Si(OR<2> )3 (R<1> is an epoxy-containing atomic group; R<2> is methyl or ethyl) (e.g. a compound of formula II), containing a very small amount of an organic base, (D) chamfered silica powder having <=100μm maximum particle diameter and (E) a curing promoter as essential components. The amount of the component D is preferably 25-90 pts.wt. based on the whole amount of the resin composition. Dimethylamine or pyridine may be cited as the organic base to be added in the component B and its blending ratio is preferably 0.05-5% based on the silane coupling agent.

Description

Detailed Description of the Invention

[0001]

The present invention relates to moisture resistance, solder heat resistance,
The present invention relates to an epoxy resin composition having excellent moldability and thermal conductivity and a semiconductor encapsulation device.

[0002]

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

[0003]

A conventional semiconductor device sealed with a resin composition comprising an epoxy resin such as a novolac type epoxy resin, a novolac type phenolic resin and an inorganic filler is subjected to solder bath dipping of the entire device. There is a drawback that the moisture resistance is lowered. In particular, when a semiconductor device that has absorbed moisture is dipped, peeling between the encapsulating resin and the semiconductor chip, or the encapsulating resin and the lead frame, and internal resin cracking cause significant deterioration in moisture resistance, causing disconnection and moisture due to electrode corrosion. As a result, there is a drawback that a semiconductor device cannot guarantee long-term reliability.

Further, by highly filling the inorganic filler, the proportion of the resin component is reduced, and the moisture absorption of the resin composition can be reduced. Since the interface between the component and the inorganic filler increases, there is a drawback that the internal resin crack propagates along the interface to the external resin crack.

Further, due to the increase in the amount of heat generated by the semiconductor element due to high integration, a material having a high thermal conductivity is being demanded not only for the package structure but also for the sealing resin.
Since crystalline silica has a higher thermal conductivity than fused silica and the like, a composition using this as a filler can be expected to have high thermal conductivity, but sharply crushed crystalline silica has a high thermal conductivity. There was a drawback that good fluidity could not be obtained.

The present invention has been made in order to solve the above-mentioned drawbacks and is less affected by moisture absorption, and is particularly excellent in moisture resistance after solder bath immersion, solder heat resistance, moldability, fluidity, and high thermal conductivity. , Long-term reliability is guaranteed without peeling between the encapsulating resin and the semiconductor chip or between the encapsulating resin and the lead frame, no internal resin cracks, no wire breakage due to electrode corrosion, and no leakage current due to moisture. It is intended to provide an epoxy resin composition and a semiconductor encapsulation device that can be used.

[0007]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above object, the present inventor has found that moisture resistance can be improved by using a specific epoxy resin, a specific silane coupling agent and a specific filler. It was found that a resin composition having excellent properties, solder heat resistance, moldability, etc. can be obtained, and the present invention has been completed.

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

[0009]

Embedded image (In the formula, n represents 0 or an integer of 1 or more) (B) Phenolic resin, (C) Silane coupling agent having an epoxy group represented by the following general formula, to which an organic base is added in a very small amount,

[0010]

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 corner-taken crystalline silica powder having a maximum particle size of 100 μm or less and (E) a curing accelerator are essential components, and For the resin composition, the above-mentioned (D) chamfered crystalline silica powder
The epoxy resin composition is characterized by containing 90% by weight. A semiconductor encapsulation device is obtained by encapsulating a semiconductor chip with a cured product of this epoxy resin composition.

The present invention will be described in detail below.

As the epoxy resin (A) used in the present invention, the one represented by the above general formula 5 is used. In addition, a novolac-based epoxy resin, an epibis-based epoxy resin, and other known epoxy resins can be used in combination with this epoxy resin.

The (B) phenol resin 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 groups of the epoxy resin (A). As a specific compound, for example,

[0014]

[Chemical 7] (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]

[Chemical 9] (However, n represents 0 or an integer of 1 or more)

[0017]

[Chemical 10] (However, n represents 0 or an integer of 1 or more)

[0018]

[Chemical 11] (However, n represents 0 or an integer greater than or equal to 1) etc., These can be used individually or in mixture.

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

[0020]

[Chemical 12]

[0021]

[Chemical 13] Etc., and these can be used alone or in combination.

It is important to add a very small amount of organic base to the silane coupling agent. The hydrolyzability can be increased 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 in combination of two or more. The blending ratio of the organic base is preferably 0.05 to 5% by weight based on the silane coupling agent. If the content 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 decreases, which is not preferable.

The (D) chamfered crystalline silica powder used in the present invention is preferably a chamfered crystalline 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. If the average particle size exceeds 30 μm, the moisture resistance and the moldability are deteriorated, which is not preferable. The blending ratio of the chamfered crystalline silica powder is preferably 25 to 90% by weight based on the total resin composition. When the proportion is less than 25% by weight, the hygroscopicity of the resin composition is high and the moisture resistance after solder immersion is poor, and when it exceeds 90% by weight, the fluidity is extremely deteriorated and the moldability is poor, which is not preferable. If an organic base is added to the silane coupling agent to the chamfered crystalline silica powder 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.

As the curing accelerator (E) used in the present invention, a phosphorus curing accelerator, an imidazole curing accelerator, and D
A wide range of BU-based curing accelerators and other curing accelerators can be used. These can be used alone or in combination of two or more kinds. It is desirable that the curing accelerator is blended in an amount of 0.01 to 5% by weight based on the total 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 characteristics will be poor, and if it exceeds 5% by weight, the fluidity will be extremely poor and the moldability will be poor.
Furthermore, the electrical characteristics are 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, phenolic resin, specific silane coupling agent, chamfered crystalline silica powder and curing accelerator as essential components. As long as it does not conflict, and if necessary, for example, natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, esters, release agents such as paraffins, flame retardants such as antimony trioxide, A colorant such as carbon black, a rubber-based or silicone-based low stress imparting agent, and the like can be appropriately added and blended.

When the epoxy resin composition of the present invention is prepared as a molding material, the general method is to compound the specific silane coupling agent and the organic base into the chamfered crystalline silica powder for surface treatment, Epoxy resin, phenolic resin, chamfered crystalline silica powder treated with a specific silane coupling agent, and a curing accelerator and other components are mixed and sufficiently mixed with a mixer or the like, and then melt-mixing treatment with a heat roll or It is possible to perform a mixing treatment with a kneader or the like, then cool and solidify and pulverize to a suitable size to obtain a molding material. When the molding material thus obtained is applied to sealing, coating, insulation, 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 above molding material. 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 method of sealing 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. For curing by heating, it is desirable to heat and cure at 150 ° C or higher.

[0028]

The epoxy resin composition and the semiconductor encapsulation device of the present invention are synergistically prepared by using a specific epoxy resin, a phenolic resin, a specific silane coupling agent, a chamfered crystalline silica powder and a curing accelerator. It reduces water absorption of the composition, improves moldability, fluidity, thermomechanical properties and low stress, eliminates resin cracking after solder immersion and solder reflow, and reduces deterioration in moisture resistance. .

[0029]

EXAMPLES 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 Square-cut crystalline silica powder (average particle size: 20 μm, maximum particle size: 100)
74%, fine fused spherical silica (average particle size 0.5
μm) 10% into a Henschel mixer, and while stirring, add 0.4% of the silane coupling agent of the above chemical formula 12 and 4 × 10 ^-4 % of diethylamine to the surface treatment of the square-shaped crystalline silica powder and fine fused spherical silica. did. Next, the epoxy resin containing the dicyclopentadiene skeleton of the above chemical formula 7.
1%, 1.2% of the above-mentioned phenolic resin of Chemical formula 7, 2.9% of the above-mentioned phenolic resin of Chemical formula 8, triphenylphosphine
0.2%, carnauba wax 0.4%, carbon black
0.3% and antimony trioxide 2.0% were mixed at room temperature, further kneaded and cooled at 70 to 100 ° C., and then pulverized to produce a molding material (A).

Example 2 Square-trimmed crystalline silica powder (average particle size 20 μm, maximum particle size 100
74%, fine fused spherical silica (average particle size 0.5
μm) 10% into a Henschel mixer, and while stirring, add 0.4% of the above-mentioned silane coupling agent of Chemical formula 13 and 4 × 10 ^-4 % of diethylamine to the surface treatment of the chamfered crystalline silica powder and fine fused spherical silica. did. Next, the epoxy resin containing the dicyclopentadiene skeleton of the above chemical formula 7.
1%, tetrabromobisphenol A type epoxy resin 1.
5%, 1.2% of the above-mentioned phenol resin of Chemical formula 7, 2.9% of the above-mentioned phenol resin of Chemical formula 8, triphenylphosphine
0.2%, carnauba wax 0.4%, carbon black
0.3% and antimony trioxide 2.0% were mixed at room temperature, further kneaded and cooled at 70 to 100 ° C., and then pulverized to produce a molding material (B).

Example 3 Square-powdered crystalline silica powder (average particle size: 20 μm, maximum particle size: 100)
74%, fine fused spherical silica (average particle size 0.5
μm) 10% into a Henschel mixer, and while stirring, add 0.4% of the silane coupling agent of the above chemical formula 12 and 4 × 10 ^-4 % of diethylamine to the surface treatment of the square-shaped crystalline silica powder and fine fused spherical silica. did. Next, the epoxy resin containing the dicyclopentadiene skeleton of the above chemical formula 7.
1%, tetrabromobisphenol A type epoxy resin 1.
5%, 1.2% of the above-mentioned phenol resin of Chemical formula 7, 2.9% of the above-mentioned phenol resin of Chemical formula 9, triphenylphosphine
0.2%, carnauba wax 0.4%, carbon black
0.3% and antimony trioxide 2.0% were mixed at room temperature, further kneaded and cooled at 70 to 100 ° C., and then pulverized to produce a molding material (C).

Comparative Example 1 70% of chamfered crystalline silica powder (average particle size 20 μm) and 10% of fine fused spherical silica (average particle size 0.5 μm) were placed in a Henschel mixer, and the silane cup of Chemical formula 12 above was stirred while stirring. 0.4% of a ring agent was added to the surface of the rounded crystalline silica powder and fine fused spherical silica. Next, 2.0% of tetrabromobisphenol A type epoxy resin, 8.1% of o-cresol novolac type epoxy resin, 2.0% of phenol compound of the above chemical formula 7, 4.6% of phenol resin of the above chemical formula 8, 0.2% of triphenylphosphine, carnauba wax. 0.4%, carbon black 0.3% and antimony trioxide 2.0% were mixed at room temperature, further kneaded and cooled at 70 to 100 ° C., and then pulverized to produce a molding material (D).

Comparative Example 2 74% of chamfered crystalline silica powder (average particle size 20 μm) and 10% of fine fused spherical silica (average particle size 0.5 μm) were placed in a Henschel mixer, and the silane cup of the above chemical formula 12 was stirred while stirring. Crystallized silica powder with 0.4% ring agent
Surface treatment of fine fused spherical silica was performed. Next, tetrabromobisphenol A-type epoxy resin 1.5%, o-cresol novolac-type epoxy resin 6.2%, the above-mentioned phenol resin 1.5%, and the above-mentioned chemical resin 8
3.5%, triphenylphosphine 0.2%, carnauba wax 0.4%, carbon black 0.3%, antimony trioxide 2.0% are mixed at room temperature, further kneaded and cooled at 70-100 ° C, and then crushed to form molding material (E). Was manufactured.

Comparative Example 3 74% of chamfered crystalline silica powder (average particle size 20 μm) and 10% of fine fused spherical silica (average particle size 0.5 μm) were placed in a Henschel mixer, and the silane cup of Chemical formula 12 above was stirred while stirring. 0.4% of a ring agent was added to the surface of the rounded crystalline silica powder and fine fused spherical silica. Next, the epoxy resin containing the dicyclopentadiene skeleton of the above chemical formula 5
7.1%, tetrabromobisphenol A type epoxy resin
1.5%, 1.2% of the above-mentioned phenol resin of Chemical formula 7, 2.9% of the above-mentioned phenol resin of Chemical formula 8, 2.9% of triphenylphosphine, 0.4% of carnauba wax, 0.3% of carbon black, 2.0% of antimony trioxide are mixed at room temperature. After further kneading and cooling at 70 to 100 ° C., the mixture was pulverized to produce a molding material (F).

Molding materials (A) to (F) produced in this way
Was used to transfer transfer 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 encapsulation devices, and the results are shown in Table 1. The epoxy resin composition and the semiconductor encapsulation device of the present invention are excellent in moisture resistance, solder heat resistance, and moldability. Therefore, the remarkable effect of the present invention could be confirmed.

[0037]

[Table 1] * 1: Spiral flow measurement (175 ° C) according to EMMI-I-66. * 2: Higher flow viscosity (175 ° C). * 3: Prepare a molded product (test piece) obtained by transfer molding at 175 ° C, 80 kg / cm ² for 2 minutes, and
Post-curing was carried out at 8 ° C. for 8 hours, and the test was conducted according to JIS-K-6911. * 4: A molded product similar to * 3 was prepared, post-cured at 175 ° C for 8 hours, and a test piece of appropriate size was measured using a thermomechanical analyzer. * 5: A 100 mm diameter, 25 mm thick molded product was made and measured using a thermal conductivity meter. * 6, * 7: VQFP 80pin (12x
12 x 1.4mm) Package and use molding material for 175
After transfer molding at ℃ for 2 minutes, post-curing was performed at 175 ℃ for 8 hours. The semiconductor encapsulation device thus obtained
After moisture absorption treatment at 85% for 48 hours at ℃, it was calculated by the increased weight. In addition, this is an air reflow machine (M
ax 240 ℃) and inspected for external and internal cracks.

[0038]

As is clear from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulation device of the present invention synergistically have excellent moisture resistance, solder heat resistance, moldability, and high thermal conductivity. Further, it is also excellent in filling properties such as a thin package, less affected by moisture absorption, and it is possible to remarkably reduce the occurrence of wire breakage due to electrode corrosion and leakage current due to moisture.
Moreover, reliability can be guaranteed for a long period of time.

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Claims (2)

[Claims] 1. An epoxy resin represented by the following general formula (A): (However, in the formula, n represents 0 or an integer of 1 or more) (B) Phenolic resin, (C) Silane coupling agent having an epoxy group represented by the following general formula, to which an organic base is added in a very small amount: 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 corner-taken crystalline silica powder having a maximum particle size of 100 μm or less and (E) a curing accelerator are essential components, and For the resin composition, the above-mentioned (D) chamfered crystalline silica powder
An epoxy resin composition comprising 90% by weight. 2. An epoxy resin represented by the following general formula (A): (However, in the formula, n represents 0 or an integer of 1 or more) (B) Phenolic resin, (C) Silane coupling agent having an epoxy group represented by the following general formula, to which an organic base is added in a very small amount: 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 corner-taken crystalline silica powder having a maximum particle size of 100 μm or less and (E) a curing accelerator are essential components, and For the resin composition, the above-mentioned (D) chamfered crystalline silica powder
A semiconductor encapsulation device, wherein a semiconductor chip is encapsulated with a cured product of an epoxy resin composition contained in a proportion of 90% by weight.