JP2658752B2 - Epoxy resin composition and semiconductor device - Google Patents

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 containing a biphenyl-type epoxy resin as an epoxy resin as a main component and a semiconductor device sealed with a cured product thereof.

[0002]

2. Description of the Related Art
In the semiconductor industry, resin-sealed diodes, transistors, ICs, LSIs, and super LSIs have become mainstream,
Of these, epoxy resins generally have better moldability, adhesiveness, electrical properties, mechanical properties, moisture resistance, etc. than other thermosetting resins, and therefore, semiconductor devices are often sealed with epoxy resin compositions. However, recently, the degree of integration of these semiconductor devices has been increasing, and the chip size has been increasing accordingly. On the other hand, package external dimensions are becoming smaller and thinner with the demand for smaller and lighter electronic devices. Further, in the method of attaching a semiconductor component to a circuit board, surface mounting of the semiconductor component has been widely performed due to a high density of components on the substrate and a reduction in thickness of the substrate.

[0003] However, when a semiconductor device is surface-mounted, it is common to immerse the entire semiconductor device in a solder bath or to pass the semiconductor device through a high-temperature zone in which the solder is melted. Cracks occur in the layer, and peeling occurs at the interface between the lead frame or chip and the sealing resin. Such cracks and peeling become more remarkable when the sealing resin layer of the semiconductor device absorbs moisture before the thermal shock at the time of surface mounting. Therefore, the reliability of the semiconductor device sealed with the epoxy resin composition after mounting may be greatly impaired.

[0004] In particular, recently, attention has been paid to the use of a biphenyl type epoxy resin as an epoxy resin, but there is a demand for a solution to the above problems in an epoxy resin composition using a biphenyl type epoxy resin.

The present invention has been made in view of the above circumstances, and has good fluidity and excellent moldability.
An epoxy resin composition containing a biphenyl-type epoxy resin as a main component, which gives a cured product with a low occurrence of internal voids, a high glass transition temperature, a large elongation, a good adhesion, and a low hygroscopicity. It is an object of the present invention to provide a semiconductor device having high reliability even after thermal shock during surface mounting sealed with a cured product of an epoxy resin composition.

[0006]

The present inventors have made intensive studies to achieve the above object, and have found that an epoxy resin composition containing an epoxy resin, a phenol resin, an inorganic filler, etc. As a resin,
(A) a naphthalene ring-containing epoxy resin represented by the following general formula (1) and (b) a biphenyl type epoxy resin represented by the following general formula (2) in a weight ratio of (a) / (b) = 0.
An epoxy resin used in combination at a ratio of 1 to 1 is used, and (c) a polyfunctional phenol resin represented by the following general formula (3) and (d) a phenol resin represented by the following general formula (4) as a phenol resin. When an aralkyl-type phenol resin is used in combination with a phenol resin obtained by using the aralkyl-type phenol resin at a weight ratio of (c) / (d) = 0.5 to 4, an epoxy resin composition having excellent properties can be obtained. I found it.

That is, conventional epoxy resin compositions containing a biphenyl-type epoxy resin as a main component are not satisfactory in terms of moldability and the rate of occurrence of defects such as internal voids.
On the other hand, the epoxy resin composition of the present invention has good flowability and excellent moldability, has extremely low occurrence rate of defects such as internal voids, has a high glass transition temperature, and has an elastic modulus in a region higher than the glass transition temperature. Have been found to provide a cured product having a low elongation, high elongation, excellent low stress properties, good adhesion, and low hygroscopicity, and have accomplished the present invention.

[0008]

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[0009]

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[0010] Accordingly, the present invention provides (I) (a) a naphthalene ring-containing epoxy resin represented by the above general formula (1) and (b) a biphenyl type epoxy resin represented by the above general formula (2) in a weight ratio. And (a) / (b)
= An epoxy resin used in combination at a ratio of 0.1 to 1; (II) (c) a polyfunctional phenol resin represented by the general formula (3); and (d) an aralkyl represented by the general formula (4). (C) / (d) =
Provided are a phenolic resin used in combination at a ratio of 0.5 to 4, (III) an epoxy resin composition containing an inorganic filler, and a semiconductor device sealed with a cured product of the epoxy resin composition. .

Hereinafter, the present invention will be described in more detail. The epoxy resin composition of the present invention comprises a naphthalene ring-containing epoxy resin, a biphenyl type epoxy resin, a polyfunctional phenol resin having a specific structure, an aralkyl It is obtained by blending a phenolic resin and an inorganic filler.

Here, as the naphthalene ring-containing epoxy resin as the first essential component, a resin represented by the following general formula (1) is used.

[0013]

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Specific examples of such a naphthalene ring-containing epoxy resin include the following compounds. .

[0015]

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[0016]

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As the second essential component, a biphenyl type epoxy resin represented by the following general formula (2) is used. This biphenyl type epoxy resin is used in combination with the above-mentioned naphthalene ring-containing epoxy resin. Thereby, the adhesiveness of the obtained cured product can be significantly improved.

[0018]

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Specific examples of such a biphenyl type epoxy resin include the following compounds.

[0020]

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It is to be noted that among the above-mentioned biphenyl type epoxy resins, the compound of the above formula (5) is particularly capable of lowering the viscosity of the composition and making it possible to reduce the total chlorine content in the composition to 500 ppm or less. It is preferably used from the point of view.

In the present invention, the epoxy resin (a) containing the naphthalene ring of the above formula (1) and the biphenyl type epoxy resin (b) of the formula (2) are used in a weight ratio of (a) / (b). = 0.1-1, preferably 0.2-0.
8 at the same time. If (a) / (b) is less than 0.1, the viscosity becomes too low to cause internal voids, and the glass transition temperature becomes low.
When (b) is more than 1, the adhesiveness is hardly developed, and the melt viscosity of the epoxy resin becomes too high, so that when sealing a multi-pin package or a thin package, there is a problem in moldability and sealing is performed. Later reliability will be reduced.

In the composition of the present invention, other epoxy resins can be used in addition to the above-mentioned epoxy resins. As the other epoxy resins, an epoxy resin having at least two epoxy groups in one molecule is typically used. Resins, specifically, bisphenol A type epoxy resin, phenol novolak type epoxy resin, triphenol alkane type epoxy resin and polymers thereof, dicyclopentadiene type epoxy resin, phenol aralkyl type epoxy resin, glycidyl ester type Epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, halogenated epoxy resins and the like are exemplified.

In this case, the mixing ratio of the naphthalene ring-containing epoxy resin of the above formula (1) and the biphenyl type epoxy resin (b) of the formula (2) is 50% (% by weight, hereinafter) of the whole epoxy resin in the composition. The same applies above, and it is particularly preferable to set the content to 70 to 85% from the viewpoint of maintaining low water absorption, high adhesive strength, and high glass transition temperature.

Next, in the composition of the present invention, as a phenol resin acting as a curing agent for the epoxy resin, a polyfunctional phenol resin represented by the following general formula (3) and (d) a phenol resin represented by the following general formula (3) It is used in combination with the aralkyl-type phenol resin shown in 4). By using the phenolic resins of the formulas (3) and (4) together as a curing agent for the epoxy resins of the formulas (1) and (2), 150
Despite having a glass transition temperature of not less than ° C., remarkable lowering of elasticity can be achieved in a region not lower than the glass transition temperature.

[0026]

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Here, specific examples of the polyfunctional phenol resin of the above formula (3) include the following compounds.

[0028]

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Among these polyfunctional phenol resins, the compound of the above formula (6) is preferably used because it can lower the viscosity of the composition and impart stable moldability and curability. .

Specific examples of the alkenyl-type phenol resin of the above formula (4) include the following compounds.

[0031]

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In the present invention, as the phenol resin, the polyfunctional phenol resin (c) of the above formula (3) and the formula (4)
(C) / (d) = 0.5-4, preferably 1-3, in a weight ratio with the alkenyl type phenol resin (d). When (c) / (d) is less than 0.5, the glass transition temperature becomes too low, and when (c) / (d) exceeds 4, the water absorption increases and good adhesive strength cannot be obtained. Occurs.

As the phenolic resin, in addition to the above-mentioned phenolic resins (c) and (d), a conventionally known phenolic resin, for example, a novolak-type phenolic resin, a resin
Phenol resin, triphenol alkane resin,
A naphthalene ring-containing phenol resin, a dicyclopentadiene-type phenol resin or the like can be added. In addition,
Of these, naphthalene ring-containing phenol resins and dicyclopentadiene-type phenol resins are preferably used.

The mixing ratio of the polyfunctional phenol resin of the formula (3) and the alkenyl phenol resin of the formula (4) is at least 10% of the total phenol resin in the composition.
In particular, it is preferable that the content be 30 to 100% from the viewpoint of achieving a high glass transition temperature, high adhesion, and low moisture absorption.

In the present invention, the ratio of the amount of the epoxy group in the epoxy resin to the amount of the phenolic hydroxyl group in the phenol resin is 0.5 to 0.5.
2, it is particularly preferable to mix so as to be in the range of 0.8 to 1.5, and if the compounding ratio is out of the above range, unreacted epoxy resin or phenol resin remains, or sufficient strength cannot be obtained, May reduce moisture resistance.

In the present invention, other curing agents such as an amine-based curing agent and an acid anhydride-based curing agent can be used in combination with the above-mentioned phenol resin within a range not to impair the object of the present invention.

In the present invention, as the inorganic filler,
What is usually mix | blended with an epoxy resin composition can be used. Specifically, fused silica, silica such as crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fibers, and the like,
Among them, fused silica is preferred.

The average particle size and shape of these inorganic fillers are not particularly limited.
The diameter is preferably 15 to 15 μm, and a spherical one is preferably used in order to increase the packing and reduce the stress on the chip surface. In order to increase the bonding strength between the resin and its surface, it is preferable to use an inorganic filler which has been previously surface-treated with a silane coupling agent or the like. Further, by adding a small amount of fine silica (average particle size of 0.5 to 3 μm), the resin strength can be further improved.

One of the above inorganic fillers may be used alone or two or more of them may be used in combination. The amount of the inorganic filler is not particularly limited. ~ 1000 parts, especially 200 ~
The range is preferably set to 700 parts.

Further, the composition of the present invention may contain a curing catalyst. Examples of the curing catalyst include an imidazole compound, a tertiary amine compound, and a phosphorus-based compound. The amount of the curing catalyst is not particularly limited, but is 0.1 to 100 parts by weight based on 100 parts of the total amount of the epoxy resin and the phenol resin.
It is preferably 2 parts, especially 0.4 to 1.5 parts.

The composition of the present invention may further contain other various additives as required. For example, thermoplastic resins, thermoplastic elastomers, organic synthetic rubbers, low stress agents such as silicones, waxes such as carnauba wax, fatty acids such as stearic acid and metal salts thereof, pigments such as carbon black, cobalt blue, red iron oxide, and oxidation Flame retardants such as antimony and halogen compounds, silane coupling agents such as glycidoxypropyltrimethoxysilane, surface treatment agents such as alkyl titanates, antioxidants, and additives such as halogen trapping agents can be blended. it can. Particularly, the composition of the present invention can be reduced in stress by adding a silicone-modified epoxy resin or phenol resin as an additive, and a thermoplastic resin such as a styrene-butadiene-methyl methacrylate copolymer is added. Thereby, high adhesiveness and impact resistance can be obtained.

The epoxy resin composition of the present invention is prepared by uniformly stirring and mixing predetermined amounts of the above-mentioned components during the production thereof.
It can be obtained by kneading with a kneader, roll, extruder or the like which has been heated to 70 to 95 ° C. in advance, cooling, pulverizing, or the like. Here, there is no particular limitation on the order of compounding the components.

The epoxy resin composition of the present invention thus obtained can be effectively used for sealing semiconductor devices such as SOP, SOJ, TSOP, TQFP, etc. A method such as transfer molding, injection molding, and casting can be employed. The molding temperature of the epoxy resin composition of the present invention is preferably 150 to 180 ° C. for 30 to 180 seconds, and post-curing is preferably performed at 150 to 180 ° C. for 2 to 16 hours.

[0044]

The epoxy resin composition of the present invention has good flowability and excellent moldability, has little occurrence of internal voids and the like, has a high glass transition temperature, has a large elongation, and has good adhesiveness. And gives a cured product having low hygroscopicity. Therefore,
When a full-mold package such as a power transistor or a power IC is sealed with the composition of the present invention, there is no defect such as unfilled, and a highly reliable semiconductor product excellent in heat dissipation and excellent in heat dissipation can be manufactured. can do.

[0045]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. All parts in each example are parts by weight.

The following tests were performed for each example. (A) Spiral flow 175 ° C, 70k using a mold conforming to EMMI standard
g / cm ² . (B) Flexural strength and flexural modulus 175 ° C, 70 kg / cm according to JIS-K6911
^2. A bending test piece of 10 × 4 × 100 mm was molded under the condition of a molding time of 2 minutes, and was subjected to post-curing at 180 ° C. for 4 hours. (C) Expansion coefficient, glass transition temperature Using a test piece having a diameter of 4 mm and a length of 15 mm, the value when the temperature was raised at a rate of 5 ° C. per minute by the TMA method was measured. (D) Solder crack resistance after moisture absorption 80-pin QFP was treated with an epoxy resin composition at 175 ° C and 70 ° C.
Molded under the conditions of kg / cm ² and molding time of 2 minutes, 180 ° C
For 4 hours. 85 ℃ / 85% R
After leaving in an atmosphere of H for 168 hours, IR reflow was performed for 3 hours.
The measurement was performed for 0 seconds, and the number of package cracks was measured. (E) Water absorption A disk having a diameter of 50 mm and a thickness of 2 mm, which was molded under the conditions of a molding time of 175 ° C., 70 kg / cm ² and a molding time of 2 minutes, and post-cured at 180 ° C. for 4 hours, was subjected to 121 ° C./100% R.
It was left in an atmosphere of H for 24 hours, and the water absorption was measured. (F) Adhesiveness A cylindrical molded product having a diameter of 5 mm was formed on a 42 alloy plate at 175 ° C. for 7
Molding under the conditions of 0 kg / cm ² and molding time of 2 minutes, 180
After post-curing at 4 ° C. for 4 hours, the adhesive strength between the molded product and 42 alloy was measured.

Examples and Comparative Examples The following epoxy resin and phenol resin were used in the proportions shown in Table 1, and 1,8-diazabicyclo (5.4.0) undecene-7 was used as a curing catalyst in an amount of 0%. .6 parts, triphenylphosphine 0.5
Parts, 250 parts of fused silica (I), 250 parts of fused silica (II), 50 parts of fused silica (III), 8 parts of antimony trioxide, 1.5 parts of carbon black, 1 part of carnauba wax, and γ 3 parts of glycidoxypropyltrimethoxysilane are uniformly melt-mixed with two rolls of heat, cooled and pulverized to obtain nine types of epoxy resin compositions (Examples 1 to 3).
5, Comparative Examples 1-4) were obtained.

The above-mentioned tests were conducted on the obtained epoxy resin composition. Table 1 shows the results.

[0049]

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[0050]

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Fused silica (I) Spherical silica having a specific surface area of 1.4 m ² / g and an average particle size of 15 μm (II) Spherical silica having a specific surface area of 2.5 m ² / g and an average particle size of 10 μm (III) Specific surface area of 10 m ² / G, average particle size 1.0 μm
Spherical silica

[0052]

[Table 1]

From the results shown in Table 1, it can be seen that the epoxy resin compositions (Examples 1 to 5) have good flowability, have less occurrence of internal voids and the like, are excellent in moldability, have a high glass transition temperature, and have high elongation. It was confirmed that a large cured product having good adhesion and low hygroscopicity was obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location H01L 23/29 H01L 23/30 R 23/31 (72) Inventor Takayuki Aoki Matsuida-machi, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory (72) Inventor Kazutoshi Tomiyoshi Matsuida-cho, Usui-gun, Gunma Pref. 56) References JP-A-4-164917 (JP, A) JP-A-4-173828 (JP, A) JP-A 1-292029 (JP, A)

Claims (2)

(57) [Claims] (I) (a) a naphthalene ring-containing epoxy resin represented by the following general formula (1) and (b) a biphenyl type epoxy resin represented by the following general formula (2) in a weight ratio of (a) / (B) = an epoxy resin used in combination at a ratio of 0.1 to 1, (II) (c) a polyfunctional phenol resin represented by the following general formula (3) and (d) an aralkyl phenol resin represented by the following general formula (4) in a weight ratio of (c) / (d) =
A phenolic resin used in combination at a ratio of 0.5 to 4, (III) An epoxy resin composition comprising an inorganic filler. 2. A semiconductor device sealed with a cured product of the epoxy resin composition according to claim 1.