JP2002284855A - Thermosetting resin composition, epoxy resin molding material using the same, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition and an epoxy resin molding material excellent in hardenability, flowability, and preservability, and highly reliable in moisture resistance, and a semiconductor device using the same. SOLUTION: The thermosetting resin composition mandatorily contains (A) a compound having two or more epoxy groups in a molecule, (B) a compound having two or more phenolic hydroxyl groups in a molecule, and (C) a phosphonium compound of a specified structure; the epoxy resin molding material contains said thermosetting resin composition; and the semiconductor device is sealed in said epoxy resin molding material as hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition having good curability and preservability and useful in the field of electric and electronic materials, an epoxy resin molding material using the same, and a cured product thereof. The present invention relates to a semiconductor device sealed by the above.

[0002]

2. Description of the Related Art In recent years, electric and electronic materials, particularly IC encapsulating materials, have been required to have a rapid curing property for the purpose of improving production efficiency and a storage property for improving handling properties during distribution and storage. , Is being asked.

Heretofore, epoxy resins for the field of electronics have been used as curing catalysts in various forms such as amines, imidazole compounds, nitrogen-containing heterocyclic compounds such as diazabicycloundecene, quaternary ammonium and phosphonium compounds. The compound has been used.

[0004] These commonly used curing catalysts often exhibit a curing acceleration effect at relatively low temperatures. This causes a decrease in quality as a product, such as an increase in viscosity during production and storage of the resin composition, a decrease in fluidity, and a variation in curability.

In order to solve this problem, in recent years, a so-called latent curing accelerator which suppresses a change with time in viscosity and fluidity at a low temperature and causes a curing reaction only by heating during shaping and molding has been developed. Research is being actively pursued. As a means for protecting the active site of the curing accelerator with an ion pair, studies have been made to develop latentness.
In JP-A-41290, a latent curing accelerator having a salt structure of various organic acids and phosphonium ions is proposed. However, since this phosphonium salt is relatively easily affected by the external environment of the ion pair, a semiconductor encapsulating material using a relatively low-viscosity curing agent such as a recent low-molecular epoxy resin or a phenol aralkyl resin has a problem. There is a problem that the fluidity and the preservability deteriorate.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a thermosetting resin composition having good curability, fluidity and preservability, which is useful in the field of electric and electronic materials, and an epoxy resin molding material using the same. And a semiconductor device sealed with a cured product thereof.

[0007]

Means for Solving the Problems The present inventors use a phosphonium compound having a specific structure together with a compound having two or more epoxy groups in one molecule and a compound having two or more phenolic hydroxyl groups in one molecule. As a result, it has been found that a resin composition and an epoxy resin molding material having excellent curability, fluidity, and preservability are obtained at the same time, and the present invention has been completed.

That is, the present invention provides a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a compound represented by the general formula (1): A thermosetting resin composition comprising the represented phosphonium compound (C) as an essential component.

[0009]

Embedded image (However, R ₁ , R ₂ , R ₃ and R ₄ are a monovalent organic group or a monovalent aliphatic group having an aromatic ring or a heterocyclic ring, and may be the same or different. R ₅ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X represents a divalent hydrocarbon group having 1 to 6 carbon atoms, and m is an integer of 1 to 3 And n represents an integer of 3 to 7.)

The present invention also provides a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a compound represented by the general formula (1). An epoxy resin molding material comprising a phosphonium compound (C) and an inorganic filler (D) as essential components, and a semiconductor device sealed with a cured product thereof.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The compound (A) having two or more epoxy groups in one molecule used in the present invention is not limited as long as it is a compound having two or more epoxy groups in one molecule. Epoxy resins, epoxy compounds, etc. produced by reacting epichlorohydrin with hydroxyl groups such as biphenols, phenolic resins such as biphenol, phenolic resins, naphthols, etc., biphenyl type epoxy resin, novolak type epoxy resin, naphthalene type epoxy resin, etc. It is. Other examples include an epoxy resin such as an alicyclic epoxy resin, which is obtained by oxidizing an olefin with a peracid and epoxidized, and a compound obtained by epoxidizing a dihydroxybenzene such as hydroquinone with epichlorohydrin.

The compound (B) having two or more phenolic hydroxyl groups in one molecule used in the present invention acts as a curing agent for the compound (A) having two or more epoxy groups in one molecule. is there. Specifically, a phenol novolak resin, a cresol novolak resin, an alkyl-modified novolak resin (including a resin in which a double bond of a cycloalkene is reacted with a phenol by a Friedel-Crafts type reaction and cocondensed), a phenol aralkyl resin, a naphthol Such as a resin obtained by co-condensing phenols and phenols with a carbonyl group-containing compound, and a compound in which two or more hydrogen atoms bonded to an aromatic ring in one molecule are substituted with a phenolic hydroxyl group. I just need.

The phosphonium compound (C) used in the present invention
Is a salt that functions as a curing accelerator and is represented by the general formula (1) and is formed of an ion pair of a phosphonium cation and an anion obtained by releasing one proton from a cyclic phenol derivative.

As the phosphonium cation forming such a structure, a tetra-substituted phosphonium ion having a substituted or unsubstituted aryl group or alkyl group as a substituent is preferable since it is stable against heat and hydrolysis, and Specifically, triarylmonoalkyl originated from phosphonium halides synthesized from tetraaryl-substituted phosphoniums such as tetraphenylphosphonium and tetratolylphosphonium, triarylphosphines such as methyltriphenylphosphonium and ethyltriphenylphosphonium and alkyl halides Examples thereof include tetraalkyl-substituted phosphonium such as phosphonium, tetrabutylphosphonium, and tetraoctylphosphonium.

As a cyclic phenol derivative which releases one proton in the molecule and forms the anion part of the phosphonium compound (C), a p-alkyl-substituted phenol represented by the general formula (2) and formaldehyde are used at a high temperature. General calix [n] arenes obtained by reacting under severe conditions of high alkali concentration (n = 4 to
8) Also, a polyfunctional cyclic phenol obtained by using a substituted or unsubstituted catechol, resorcinol, or pyrogallol as a phenol source and similarly reacting with an aldehyde under high temperature and high alkali conditions is typical. An example is given.

[0016]

Embedded image (Y represents a divalent hydrocarbon group having 1 to 6 carbon atoms,
R ₆ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms. p represents an integer of 1 to 3, and q represents an integer of 4 to 8. )

From the viewpoint of the stability of the phosphonium compound and the balance of the curability, fluidity, preservability and physical properties of the cured resin, examples of particularly preferred combinations include tetraphenylphosphonium, ethyltriphenylphosphonium,
Phosphonium cations such as benzyltriphenylphosphonium and tetrabutylphosphonium, calix [n] arenes (n = 4-8), 4-t-butylcalix [n] arenes (n = 4-8), C-methyl Examples include combinations of calix [4] resorcinol arene and C-methyl calix [4] pyrogallol arene with anions that release one proton of a phenolic hydroxyl group.

The phosphonium compound (C) is prepared by converting a cyclic phenol derivative and a base which ultimately assists dehydrohalogenation, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, to an alcohol, tetrahydrofuran, N, N -Dissolved in a solvent such as dimethylformamide, followed by adding and reacting the halide of the tetra-substituted phosphonium dissolved in an appropriate solvent, and finally taking out as a solid by an operation such as recrystallization or reprecipitation. Can be synthesized.

The phosphonium compound (C) used in the present invention
Is that the interaction between the ionic molecule of the phosphonium cation and the cyclic phenol-type anion is stronger than that of a general phosphonium phenoxide salt, and does not easily exhibit activity at a temperature lower than the molding temperature, but is high in the actual shaping stage. Expresses activity and imparts so-called latency.

The phosphonium compound (C) used in the present invention
Is 100% by weight of the total weight of the compound (A) having two or more epoxy groups in one molecule and the compound (B) having two or more phenolic hydroxyl groups in one molecule, which functions as a curing agent. When the amount is about 0.2 to about 10 parts by weight, the curability, the storability, and other characteristics are well balanced and suitable.

The compounding ratio of the compound (A) having two or more epoxy groups in one molecule to the compound (B) having two or more phenolic hydroxyl groups in one molecule is as follows. The phenolic hydroxyl group of the compound (B) having two or more phenolic hydroxyl groups in one molecule and the phenolic hydroxyl group contained in the molecular compound (C) per 1 mol of the epoxy group of the compound (A) having two or more compounds. When used in a molar ratio of about 0.5 to 2 mol, preferably about 0.8 to 1.2 in total, the curability, heat resistance, electric characteristics, and the like are further improved.

The inorganic filler (D) used in the present invention is not particularly limited, and those generally used as a sealing material can be used. For example, fused crushed silica powder, fused spherical silica powder, crystalline silica powder, secondary agglomerated silica powder, alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber, etc., are particularly preferred, and fused spherical silica powder is particularly preferred. . These shapes are
It is preferable that the particles have an infinitely spherical shape, and the amount of the particles can be increased by mixing particles having different particle sizes.

The compounding amount of the inorganic filler is 100 (total) of the compound (A) having two or more epoxy groups in one molecule and the compound (B) having two or more phenolic hydroxyl groups in one molecule. 200 to 2400 per part by weight
Parts by weight are preferred. If the amount is less than 200 parts by weight, the reinforcing effect of the inorganic filler may not be sufficiently exerted.
If the amount is more than 00 parts by weight, the fluidity of the resin composition may be reduced, and poor filling may occur during molding. In particular, the compounding amount of the inorganic filler is 10% in total of the components (A) and (B).
If the amount is 250 to 1400 parts by weight per 0 parts by weight, the moisture absorption of the cured product of the molding material is reduced, and the occurrence of solder cracks in the cured product sealing the semiconductor device can be prevented. Further, since the viscosity of the molding material at the time of melting in the encapsulation molding of the semiconductor device is reduced, there is no possibility of causing a gold wire deformation inside the semiconductor device, which is more preferable. It is preferable that the inorganic filler is sufficiently mixed in advance.

The epoxy resin composition and the epoxy resin molding material of the present invention may further comprise, if necessary, γ in addition to the essential components (A) to (C) and components (A) to (D). Coupling agents such as glycidoxypropyltrimethoxysilane, coloring agents such as carbon black, brominated epoxy resins, antimony oxide, flame retardants such as phosphorus compounds, low-stress components such as silicone oil and silicone rubber, natural waxes, Various additives such as synthetic waxes, higher fats or metal salts thereof, release agents such as paraffin, antioxidants and the like can be blended, and properties of the phosphonium compound (C) which functions as a curing accelerator in the present invention. To the extent that triphenylphosphine is not impaired,
There is no problem when used in combination with other known catalysts such as 1,8-diazabicyclo (5,4,0) -7-undecene and 2-methylimidazole.

The epoxy resin composition and the epoxy resin molding material of the present invention are prepared by mixing respective essential components and other additives at room temperature with a mixer,
It is obtained by kneading with a kneading machine such as an extruder, cooling and pulverizing.

Using the epoxy resin molding material of the present invention,
In order to manufacture a semiconductor device by encapsulating an electronic component such as a semiconductor, curing and molding can be performed by a molding method such as transfer molding, compression molding, and injection molding.

The semiconductor device sealed with the cured product of the epoxy resin molding material of the present invention is included in the technical scope of the present invention and exhibits excellent moisture resistance.

[0028]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited by these examples.

[Synthesis of Compound (C)] (Synthesis Example 1) 300 mL with a cooling device and a stirring device
9. Calix [4] arene in a three-necked flask
6 g (0.025 mol), methanol 30 mL and N, N-dimethylformamide 10 mL were charged, and 60
The mixture was dissolved by stirring at ℃, and a solution in which 1.0 g (0.025 mol) of sodium hydroxide was previously dissolved in 10 mL of methanol was added while stirring. Then, 10.5 g of tetraphenylphosphonium bromide (0.025
mol) was dissolved in 40 mL of methanol. After stirring for a while, add 1 ml to the solution in the flask.
00 mL of pure water was added dropwise with stirring to obtain a pale yellow precipitate. After filtering the precipitate and washing with pure water and acetone,
Drying yielded 15.8 g of a pale yellow powder. This compound is
Let it be 1. As a result of analyzing C1 by NMR, mass spectrum, and elemental analysis, it was confirmed that C1 was the target compound represented by the chemical formula (3). The yield of the synthesis was 83%.

(Synthesis Example 2) Calix [4] arene, which is a starting material of Synthesis Example 1, was replaced with C-methyl calix [4].
All the basic operations were performed in the same manner as in Synthesis Example 1 except that the amount was changed to 13.6 g (0.025 mol) of resorcin arene, and 18.8 g of a pale yellow powder was obtained. This compound is designated as C2. As a result of analysis by NMR, mass spectrum, and elemental analysis, it was confirmed that the target compound was represented by the chemical formula (4). The yield of the synthesis was 85%.

(Synthesis Example 3) Calix [4] arene, which is a starting material of Synthesis Example 1, was replaced with C-methyl calix [4].
Pyrogallol arene 15.2 g (0.025 mol)
All the basic operations were carried out in the same manner as in Synthesis Example 1 except for changing to, to obtain 21.3 g of pale red powder. This compound is converted to C3
And As a result of analysis by NMR, mass spectrum, and elemental analysis, it was confirmed that the target compound was represented by the chemical formula (5). The yield of the synthesis was 90%.

(Synthesis Example 4) Tetraphenylphosphonium bromide, which is a starting material of Synthesis Example 1, was replaced with 9.3 g (0.025 mol) of ethyltriphenylphosphonium bromide.
1) In calix [4] arene, calix [6]
Except for changing the arene to 15.9 g (0.025 mol), all basic operations were performed in the same manner as in Synthesis Example 1 to obtain 20.4 g of a pale yellow powder. This compound is designated as C4.
As a result of analysis by NMR, mass spectrum, and elemental analysis, it was confirmed that the target compound was represented by the chemical formula (6). The yield of the synthesis was 88%.

(Synthesis Example 5) 9.7 g of benzyltriphenylphosphonium chloride (0.025 m
ol) was added to calix [4] arene in 32.4 g of 4-t-butylcalix [8] arene (0.025mo).
Except for changing to l), all the basic operations were carried out in the same manner as in Synthesis Example 1 to obtain 34.6 g of a pale yellow powder. This compound is designated as C5. As a result of analysis by NMR, mass spectrum, and elemental analysis, it was confirmed that the target compound was represented by the chemical formula (7). The yield of the synthesis was 86%.

[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[Evaluation of Thermosetting Resin Composition] The compound (C) synthesized above was compounded with a compound (A) having two or more epoxy groups in one molecule and a compound (A) having two phenolic hydroxyl groups in one molecule. In addition to compound (B) having the above and mixing,
After melt-kneading at 00 ° C. for 5 minutes on a hot plate, the mixture was pulverized by cooling to prepare a sample of the composition, which was evaluated. The evaluation method is as follows.

(1) Curing Torque (Evaluation of Curability) Using a resin composition prepared by the above sample preparation method, a curast meter (JS, manufactured by Orientec Co., Ltd.)
R Curastometer PS) at 175 ° C
The torque after 5 seconds was determined. Torque in a curast meter is a parameter of curability, and a larger value indicates higher curability.

(2) Residual rate of heat generation after curing (evaluation of storage stability) Using the resin composition prepared by the above-mentioned sample preparation method, initial heat generation after curing immediately after preparation, and curing after storage treatment at 40 ° C. for 3 days. The calorific value was measured, and the curing calorific value after storage treatment (mJ / mg) relative to the initial curing calorific value (mJ / mg)
/ Mg) was calculated. In addition, the measurement of the calorific value of the curing was performed by differential thermal analysis under the condition of a heating rate of 10 ° C./min. The larger the value, the smaller the change over time in the amount of heat generated by curing, and the better the storage stability.

(Examples 1 to 8 and Comparative Examples 1 to 6) Samples of the compositions were prepared and evaluated according to the above-mentioned methods by the formulations shown in Tables 1 and 2. In Comparative Examples 1 to 6, triphenylphosphine, 1,8-diazabicyclo [5.4.0] -7-undecene, and 2-methylimidazole, which are known curing accelerators, are used in place of the compound (C) in Examples. And tetraphenylphosphonium tetraphenylborate. Tables 1 and 2 show the evaluation results of the obtained compositions.
Shown in

[0043]

[Table 1]

[0044]

[Table 2]

In Examples 1 to 8, which are the thermosetting resin compositions of the present invention, both the curability and the preservability were good, whereas in Comparative Examples 1 to 6, the preservability was poor and the curability was low. 1
-8 showed inferior results.

[Evaluation of Epoxy Resin Molding Material] (Example 9) Biphenyl-type epoxy resin (YX-4000H made by Yuka Shell Epoxy) 52 parts by weight Phenol aralkyl resin (XL225-LL made by Mitsui Chemicals) 48 parts by weight Compound C1 3.0 Parts by weight Fused spherical silica (average particle size 15 μm, manufactured by Denki Kagaku Kogyo) 500 parts by weight Carbon black (average particle size 18 μm, manufactured by Mitsubishi Chemical) 2 parts by weight 2 parts by weight of carnauba wax were mixed, kneaded at 95 ° C. for 8 minutes using a hot roll, cooled and pulverized to obtain an epoxy resin molding material. The obtained epoxy resin molding material was evaluated by the following method. Table 3 shows the results.

Evaluation Method (1) Spiral flow was measured using a mold for measuring spiral flow according to EMMI-I-66.
The measurement was performed at 5 ° C., an injection pressure of 6.8 MPa, and a curing time of 2 minutes. Spiral flow is a parameter of liquidity,
The larger the value, the better the fluidity.

(2) Curing torque was measured using a curameter (JSR Curameter manufactured by Orientec Co., Ltd.)
(IV PS type), and the torque was measured at 175 ° C. for 45 seconds. The larger the value, the better the curability.

(3) The residual flow rate was 30 ° C. immediately after preparation.
The spiral flow value after storage for one week was measured and expressed as a percentage of the value after storage relative to the spiral flow value immediately after preparation.

(4) Moisture resistance reliability was determined by transfer molding using a mold temperature of 175 ° C., an injection pressure of 6.8 MPa,
A 16pDIP was molded with a curing time of 2 minutes, and
After curing at 75 ° C for 8 hours, 125 ° C, relative humidity of 10
In 0% water vapor, a voltage of 20 V was applied to 16 pDIP, and a disconnection defect was examined. Of the 15 packages,
The time until a defect appeared in eight or more pieces was defined as a defect time.
The unit is time. Note that the measurement time was 500 hours at the maximum, and when the number of defective packages was less than 8 at that time, the defective time was indicated as 500 hours or more. The longer the failure time, the better the moisture resistance reliability.

Examples 10 to 12 and Comparative Examples 7 to 10 Tables 3 to 10 for Examples 10 to 12 and Comparative Examples 7 to 10
According to the composition of No. 4, an epoxy resin molding material was prepared and evaluated in the same manner as in Example 9. The results are shown in Tables 3 and 4.

[0052]

[Table 3]

[0053]

[Table 4]

The epoxy resin molding materials of the present invention of Examples 9 to 12 have extremely good curability, fluidity, and preservability. Further, the semiconductor device sealed with the cured product of this epoxy resin molding material is It can be seen that the moisture resistance reliability is good. In Comparative Examples 7 to 10, curability, fluidity,
Storage stability and humidity resistance reliability could not be satisfied at the same time.

[0055]

The thermosetting resin composition and the epoxy resin molding material of the present invention have excellent curability and storage properties, and the semiconductor device sealed with the cured product of the epoxy resin molding material has a high moisture resistance. Excellent reliability and useful.

Claims (3)

[Claims] 1. A compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and phosphonium represented by the general formula (1) A thermosetting resin composition comprising the compound (C) as an essential component. Embedded image (However, R ₁ , R ₂ , R ₃ and R ₄ are a monovalent organic group or a monovalent aliphatic group having an aromatic ring or a heterocyclic ring, and may be the same or different. R ₅ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X represents a divalent hydrocarbon group having 1 to 6 carbon atoms, and m is an integer of 1 to 3 And n represents an integer of 3 to 7.) 2. A compound having two or more epoxy groups in one molecule (A), a compound having two or more phenolic hydroxyl groups in one molecule (B), a phosphonium compound represented by the general formula (1): An epoxy resin molding material characterized by comprising C) and an inorganic filler (D) as essential components. Embedded image (However, R ₁ , R ₂ , R ₃ and R ₄ are a monovalent organic group or a monovalent aliphatic group having an aromatic ring or a heterocyclic ring, and may be the same or different. R ₅ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, X represents a divalent hydrocarbon group having 1 to 6 carbon atoms, and m is an integer of 1 to 3 And n represents an integer of 3 to 7.) 3. A semiconductor device sealed with a cured product of the epoxy resin molding material according to claim 2.