JPH09255852A - Epoxy resin composition for sealing material and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition for a sealing material, excellent in adhesion between a lead frame and a cured resin product and moldability, useful in semiconductor devices by formulating a silane coupling agent having a specific structure to a specifically composed sealing resin. SOLUTION: This resin composition comprises (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler and (D) a silane coupling agent. The component A contains 40-100 pts.wt. of a dicyclopenta-diene type epoxy resin in 100 pts.wt. of the whole epoxy resin. The component C is contained in this composition in an amount of 70-95 pts.wt. in 100 pts.wt. of said composition. As a component D, a formulation containing a silane of formula I (R<1> , R<3> and R<4> are each H, a 1-12C monovalent hydrocarbon; R2 is a 1-12C divalent hydrocarbon; n is an integer of 1-3) and a silane of formula II (R<5> is a 1-12C divalent hydrocarbon; R<6> and R<7> are each H a 1-12C monovalent hydrocarbon; m is an integer of 1-3). The amount of the component D is preferably 0.05-1.5 pt.wt. per 100 pts.wt. of the component C, respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition for an encapsulant used for encapsulating a semiconductor or the like and a semiconductor device using the same.

[0002]

2. Description of the Related Art As a method for sealing electronic components such as semiconductor devices, a method using ceramic or thermosetting resin has been conventionally used. Among them, encapsulation with an epoxy resin composition is more preferable than the balance between economic efficiency and performance,
Widely used. A semiconductor device encapsulated with this epoxy resin composition for encapsulant (hereinafter referred to as encapsulating resin) is, for example, a semiconductor element mounted on a lead frame metal, and the semiconductor element and the lead frame are bonded with a bonding wire or the like. They are electrically connected to each other, and the entire semiconductor element and a part of the lead frame are sealed with a sealing resin.

As the lead frame, a lead frame made of a copper alloy is generally used because of its electric conductivity, and a lead frame made of 42 alloy is generally used because of its thermal expansion coefficient. Since these lead frames have low adhesiveness with bonding wires such as gold wires, the parts of the lead frame that are to be connected to the bonding wires are silver-plated or gold-plated in advance, and then connected to the bonding wires. Methods of improving reliability are being investigated.

Further, when a cured product of the sealing resin (hereinafter referred to as a cured resin) absorbs moisture, the absorbed moisture rapidly expands due to a thermal shock of soldering when mounting an electronic component on a mother board, and the resin absorbs moisture. In some cases, a crack may occur inside the cured product, resulting in a decrease in reliability. Therefore, as an improvement of moisture absorption solder heat resistance, a method of reducing the moisture absorption of the resin cured product by reducing the proportion of the epoxy resin, which is a component that easily absorbs moisture in the sealing resin, by filling the sealing resin with an inorganic filler, A method using an epoxy resin or the like having a low moisture absorption rate, a method using an inorganic filler whose surface is treated with a silane coupling agent or the like are being studied.

As a method of using the epoxy resin having a low moisture absorption rate, a method of using a dicyclopentadiene type epoxy resin has been studied.

However, if the sealing resin contains a high proportion of the inorganic filler and the dicyclopentadiene type epoxy resin contains a high proportion of the total epoxy resin to improve the moisture absorption solder heat resistance, the moldability is improved. Of the lead frame and the cured resin due to the temperature cycle exposed when the semiconductor device is actually used. It is presumed that the adhesiveness of these is low, but cracks were sometimes generated. Therefore, even if the sealing resin contains a high proportion of the inorganic filler and the dicyclopentadiene type epoxy resin contains a high proportion of the total epoxy resin, the moldability is excellent, and the lead frame and the resin are cured. There is a demand for a sealing resin that can be sealed with high adhesiveness to objects.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, in which a sealing resin contains a high proportion of an inorganic filler and a dicyclopentadiene type epoxy resin. It is an object of the present invention to provide an encapsulating resin which is a high-encapsulating encapsulating resin in all epoxy resins and which is excellent in both the adhesiveness between the lead frame and the cured resin and the moldability. Another object of the present invention is to provide a semiconductor device having excellent adhesiveness and moldability between a lead frame using this sealing resin and a cured resin product.

[0008]

A sealing resin (epoxy resin composition for a sealing material) according to claim 1 of the present invention comprises an epoxy resin, a curing agent, an inorganic filler and a silane coupling agent. Which is 70 to 95 parts by weight of the inorganic filler in 100 parts by weight of the sealing resin, and 40 to 100 parts of the dicyclopentadiene type epoxy resin in 100 parts by weight of the total epoxy resin. In the encapsulating resin which is contained by weight, the following formula (a) is used as a silane coupling agent.
And a silane compound represented by the following formula (b) are blended.

[0009]

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[0010]

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The sealing resin according to a second aspect of the present invention is the sealing resin according to the first aspect, wherein the inorganic filler contains silica.

A semiconductor device according to claim 3 of the present invention is obtained by encapsulating a semiconductor element mounted on a lead frame using the encapsulating resin according to claim 1 or 2.

According to the present invention, since the silane coupling agent represented by the above formula (a) and the above formula (b) is compounded in the sealing resin, the inorganic filler is added in 100 parts by weight of the sealing resin. 70 to 95 parts by weight and total epoxy resin 1
Even in a sealing resin containing 40 to 100 parts by weight of a dicyclopentadiene type epoxy resin in 00 parts by weight, these silane coupling agents have an adhesive force between an inorganic filler and a lead frame, and moldability. In order to improve the above, it is possible to perform sealing with excellent adhesiveness and moldability between the lead frame and the cured resin.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The encapsulating resin of the present invention comprises a silane compound represented by the above formula (a) and the above formula as at least a dicyclopentadiene type epoxy resin, a curing agent, an inorganic filler and a silane coupling agent. It is prepared by blending the silane compound represented by (b). It is important that the silane compound represented by the above formula (a) and the silane compound represented by the above formula (b) are blended together. If these silane coupling agents are not blended or only one of them is blended. When it is mixed, the adhesiveness with the lead frame is lowered and the formability is lowered. Among the silane compounds represented by the above formula (a), N-phenyl-γ represented by the following formula (c)
-When using aminopropyltrimethoxysilane and using γ-mercaptopropyltrimethoxysilane represented by the following formula (d) among the silane compounds represented by the above formula (b), adhesiveness and moldability are improved. The effect of improvement is large and preferable.

[0015]

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[0016]

[Chemical 6]

The silane coupling agent represented by the above formula (a) and the silane coupling agent represented by the above formula (b) are each contained in an amount of 0.05 to 1 with respect to 100 parts by weight of the inorganic filler. 0.5 parts by weight, more preferably 0.1-1.
It is preferable that 0 part by weight is blended. When the amount is less than 0.05 parts by weight, the effect of improving the adhesiveness and moldability is small, and when the amount is more than 1.5 parts by weight, the strength of the cured resin product decreases, which is a problem.

The silane coupling agent is not limited to the one containing only the silane compound represented by the above formula (a) and the silane compound represented by the above formula (b). If necessary, an aminosilane other than the compound represented by the above formula (a), such as γ-ureidopropyltrimethoxysilane, or an epoxysilane such as γ-glycidoxypropyltrimethoxysilane may be added. Good. In addition, these silane coupling agents,
Although it may be added directly to the sealing resin, the inorganic filler can be directly sprayed onto the inorganic filler, or the inorganic filler can be immersed in a solution in which the silane coupling agent is dissolved by a silane coupling agent. After the treatment, the method of adding to the encapsulating resin surely improves the adhesiveness between the resin cured product and the lead frame and the effect of improving the moldability as compared with the case of directly adding to the encapsulating resin. It is possible to obtain and is preferable.

The inorganic filler used in the present invention is not particularly limited, and examples thereof include crystalline silica, amorphous silica, alumina, magnesia, titanium oxide, calcium carbonate, magnesium carbonate, silicon nitride, talc, calcium silicate. Etc. The inorganic filler may be used alone or in combination of two or more. It is important that the inorganic filler is contained in 70 to 95 parts by weight in 100 parts by weight of the sealing resin. If the amount of the inorganic filler is less than 70 parts by weight, the amount of moisture absorption of the cured resin may increase and the heat resistance of the moisture-absorbing solder may decrease, which is a problem. If it exceeds 95 parts by weight, the viscosity of the encapsulating resin increases, Formability at the time of sealing is lowered, which is a problem. It is preferable to use silica such as crystalline silica or amorphous silica as the inorganic filler because the linear expansion coefficient of the cured resin becomes small and approaches the linear expansion coefficient of the semiconductor element.

As the epoxy resin used in the present invention, it is important that the dicyclopentadiene type epoxy resin is contained in an amount of 40 to 100 parts by weight based on 100 parts by weight of the total epoxy resin. If it is less than 40 parts by weight, the moisture absorption rate may increase and the moisture absorption solder heat resistance may decrease. Examples of the dicyclopentadiene type epoxy resin include compounds represented by the following formulas (e) and (f). In addition, p in Formula (e) represents 0 or a positive number, and q in Formula (f) represents 0 or a positive number. In addition, the epoxy resin represented by the following formula (e) is preferable because it has a great effect of improving the moisture absorption solder heat resistance.

[0021]

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[0022]

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The epoxy resin used in the present invention is not limited to the dicyclopentadiene type epoxy resin, but the dicyclopentadiene type epoxy resin may be contained in an amount of 40 parts by weight or more based on 100 parts by weight of the total epoxy resin. When blended, for example, cresol novolac type epoxy resin, bisphenol A type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, etc. can be used in combination. They may be used alone or in combination of two or more. In addition, it is preferable to use a biphenyl type epoxy resin in combination, because the moisture absorption solder heat resistance is further improved.

The curing agent used in the present invention is not particularly limited as long as it can be cured by reacting with an epoxy resin, and examples thereof include phenol novolac resin, cresol novolac resin, naphthol novolac resin and aralkyl type phenol resin. Various novolak resins, acid anhydrides such as phthalic anhydride and pyromellitic anhydride, aromatic amines such as diaminodiphenylmethane and metaphenylenediamine. The above curing agents may be used alone or in combination of two or more, and the compounding amount thereof is usually 0.5 to 1.
It is mixed in the range of 5. When the aralkyl-type phenol resin represented by the following formula (g) is used, the moisture absorption of the resin becomes low, and the moisture absorption solder heat resistance is improved, which is preferable. In the formula (g), r represents 0 or a positive integer. The aralkyl-type phenol resin is a resin obtained by reacting phenols such as phenol and cresol with aralkyl ethers.

[0025]

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Further, the phenol portion of the aralkyl type phenol resin represented by the above formula (g) is used as a curing agent in α-
When a phenol resin represented by the following formula (h) is contained instead of naphthol, the moisture absorption rate of the resin is lowered, and the moisture absorption solder heat resistance is improved, which is preferable. In the formula (h), s represents 0 or a positive integer.

[0027]

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If necessary, the encapsulating resin of the present invention may contain a curing accelerator, a release agent, a coloring agent, a stress reducing agent, a flame retardant and the like. Examples of the curing accelerator include
1,8-diaza-bicyclo (5,4,0) undecene-
7, tertiary amine compounds such as triethylenediamine and benzyldimethylamine, imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, triphenylphosphine And organic phosphine compounds such as tributylphosphine.
Examples of the release agent include carnauba wax, stearic acid, montanic acid, carboxyl group-containing polyolefin and the like. Examples of the colorant include carbon black and titanium oxide. Examples of the stress reducing agent include silicone gel, silicone rubber, silicone oil and the like. Examples of the flame retardant include antimony trioxide, halogen compounds, phosphorus compounds and the like. Two or more kinds of these curing accelerators, release agents, colorants, stress reducing agents, flame retardants and the like can be used in combination.

The sealing resin of the present invention is preferably uniformly mixed and kneaded. As a method of kneading, for example, a sealing resin is manufactured by heating using a roll, a kneader, a mixer, or the like, and then cooling, pulverizing, or the like.

[0030]

【Example】

(Examples 1 to 7 and Comparative Examples 1 to 3) As sealing resins, the following three types of epoxy resins, three types of curing agents, three types of silane coupling agents, inorganic fillers, curing accelerators, and colorants. The flame retardant and the release agent were blended in the weight ratios shown in Tables 1 and 2.

Epoxy resin a: a dicyclopentadiene type epoxy resin represented by the above formula (e) and having an epoxy equivalent of 260 [manufactured by Dainippon Ink and Chemicals, HP7200]. Epoxy resin a: Epoxy equivalent of 192. Biphenyl type epoxy resin [Yuka 4000, trade name YX4000
H] -Epoxy resin C: Tetrabromobisphenol A type epoxy resin having an epoxy equivalent of 400-Curing agent f: Hydroxyl equivalent 17 represented by the above formula (g)
0 aralkyl type phenol resin [Mitsui Toatsu Chemicals,
Product name Milex XL-225-3L] -Curing agent K: Hydroxyl equivalent 21 represented by the above formula (h)
0 phenolic resin [Nippon Steel Chemical Co., Ltd., trade name SN18
0] -Curing agent C: Phenol novolac resin having a hydroxyl equivalent of 105 [Arakawa Chemical Co., Ltd., trade name Tamanol 752] -Silane coupling agent: N represented by the above formula (c)
-Phenyl-γ-aminopropyltrimethoxysilane [manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM573] Silane coupling agent Si: γ represented by the above formula (d)
-Mercaptopropyltrimethoxysilane [Toshiba Silicone, trade name TSL8380E] -Silane coupling agent: epoxy silane [Toray Dow Corning, trade name SH6040] -Inorganic filler: amorphous silica [Denki Kagaku Kogyo Co., Ltd. Product name: FB74] -Curing accelerator: triphenylphosphine-Colorant: carbon black-Flame retardant: antimony trioxide-Release agent: carnauba wax

[0032]

[Table 1]

[0033]

[Table 2]

The above-mentioned silane coupling agent was blended after being directly sprayed directly on the inorganic filler for surface treatment. After mixing each of the above raw materials, the mixture was kneaded with a heating roll at a temperature of 85 ° C. for 5 minutes and then cooled. Then, it was pulverized to obtain a sealing resin.

(Evaluation) Using the sealing resins obtained in Examples 1 to 7 and Comparative Examples 1 to 3, an evaluation sample was prepared by the following method, and the adhesion and moldability of the evaluation sample were evaluated. ,
Moisture absorption Solder heat resistance and moisture absorption were measured by the following methods.

The adhesion was measured by molding a pudding-type evaluation sample on one surface of a 0.5 mm-thick copper plate plated with silver on the entire surface at a temperature of 170 ° C. for 90 seconds using a transfer molding machine, and then 175 It was made by post-curing at a temperature of ° C for 6 hours. Next, this evaluation sample was pulled in the shearing direction using a push-pull gauge, and the strength at the time of breaking was determined.

The moldability is 15 × after a semiconductor element of 9.6 × 9.6 × 0.4 mm is bonded to a lead frame made of silver-plated copper alloy having a thickness of 150 μm with a silver paste.
A 19 × 1.8 mm 60-pin QFP type evaluation sample (semiconductor device) was prepared in the same manner as the adhesion evaluation sample. Next, the residual air bubbles inside the 10 evaluation samples were analyzed by an ultrasonic probe (manufactured by Canon Inc., M-70).
0II) and observed bubbles having a diameter of 0.3 mm or more remained as defective.

Regarding the heat resistance to moisture-absorbed solder, a 60-pin QFP type evaluation sample similar to the moldability evaluation sample was prepared. Then, 10 of these evaluation samples were used at 85 ° C /
After treating for 72 hours under the condition of 85% RH, it was immersed in solder at 250 ° C. for 10 seconds. Next, the evaluation sample was cut in half, the cut surface was polished, and the size of cracks was observed with a microscope. Those having a crack size of 75 μm or more were determined as defective.

Regarding the moisture absorption rate, a disk-type evaluation sample having a diameter of 50 mm and a thickness of 3 mm was prepared in the same manner as the adhesion evaluation sample, dried at a temperature of 125 ° C. for 16 hours, and then 85 ° C./85% RH. After treating for 72 hours under the conditions of
The increase rate was calculated by calculating the difference from the weight immediately after drying at a temperature of 125 ° C. for 16 hours.

(Results) As shown in Tables 1 and 2, the adhesion of each Example is better than that of Comparative Example 1, and each Example is compared with Comparative Examples 2 and 3. By comparison, it was confirmed that the moldability was good. That is, it was confirmed that each Example had good adhesiveness and moldability. Further, it was confirmed that each of the examples has the same or slightly better moisture absorption solder heat resistance and moisture absorption rate as compared with each comparative example.

[0041]

The encapsulating resin according to claims 1 and 2 of the present invention comprises the silane coupling agent represented by the above formula (a) and the above formula (b) in the encapsulating resin. Therefore, even if the sealing resin contains a high proportion of the inorganic filler in the sealing resin and the dicyclopentadiene type epoxy resin in a high proportion of the total epoxy resin, When used for sealing, a sealed product having excellent adhesiveness between the lead frame and the cured resin and moldability is obtained.

The semiconductor device according to the third aspect of the present invention is a semiconductor device which is excellent in both the adhesiveness between the lead frame and the resin cured product and the moldability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 23/31

Claims (3)

[Claims] 1. An epoxy resin composition for a sealing material, which comprises an epoxy resin, a curing agent, an inorganic filler and a silane coupling agent, the epoxy resin composition for a sealing material 10.
70 to 95 parts by weight of an inorganic filler is contained in 0 parts by weight,
In addition, in the epoxy resin composition for encapsulant containing 40 to 100 parts by weight of dicyclopentadiene type epoxy resin in 100 parts by weight of total epoxy resin, it is represented by the following formula (a) as a silane coupling agent. An epoxy resin composition for a sealing material, which comprises a silane compound and a silane compound represented by the following formula (b). Embedded image (In the formula, R ¹ , R ³ and R ⁴ are hydrogen or a monovalent hydrocarbon group having 1 to 12 carbon atoms, R ² is a divalent hydrocarbon group having 1 to 12 carbon atoms, and n is an integer of 1 to 3 Is represented.) (In the formula, R ⁵ is a divalent hydrocarbon group having 1 to 12 carbon atoms,
R ⁶ and R ⁷ represent hydrogen or a monovalent hydrocarbon group having 1 to 12 carbon atoms, and m represents an integer of 1 to 3. ) 2. The epoxy resin composition for a sealing material according to claim 1, wherein the inorganic filler contains silica. 3. A semiconductor device obtained by encapsulating a semiconductor element mounted on a lead frame using the epoxy resin composition for encapsulant according to claim 1 or 2.