JPH05320320A - Epoxy resin composition and resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin composition excellent in low moisture absorption and toughness in heating and having good balance of heat resistance and curing properties and prepare a high-performance resin-sealed semiconductor device improved in crack resistance to soldering, etc., by using the epoxy resin composition. CONSTITUTION:The epoxy resin composition consists essentially of a polyhydric phenol which is a condensation product of a phenol such as m-cresol and a naphthoaldehyde such as 1-naphthoaldehyde and an epoxy resin such as o-cresol novolak resin having >=2 epoxy groups in one molecule. The resin-sealed semiconductor device is prepared by using this epoxy resin composition.

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 useful for encapsulating electronic parts and a resin-encapsulated semiconductor device using the same.

[0002]

2. Description of the Related Art Recently, LSIs, ICs, transistors, etc.
Transfer molding with an economically useful epoxy resin is performed for sealing a semiconductor. Especially recently
The surface mounting of LSIs is performed, and the number of cases in which they are directly immersed in a solder bath is increasing. At that time, the sealing material is 2
Since it is exposed to a high temperature of 00 ° C. or higher, the moisture absorbed in the encapsulant expands, causing cracks and peeling at the interface with the die pad. Therefore, the resin encapsulant is required to have improved crack resistance and adhesion, and is required to have low hygroscopicity and toughness when heated. At present, the encapsulant using glycidyl ether of o-cresol novolac as the epoxy resin and phenol novolac as the curing agent is the mainstream, but it has the above problems and is practically used in moisture-proof packaging. ing.

[0003]

The encapsulating material mainly composed of glycidyl ether of o-cresol novolac and phenol novolac is tentatively balanced in terms of heat resistance and hygroscopicity, but it is high as described above. It is not always sufficient in applications where low level of hygroscopicity is required,
Since the toughness at the time of heating is also insufficient, there is a problem in the solder cracking property. In view of such circumstances, the present inventors diligently studied an epoxy resin composition having lower hygroscopicity and toughness when heated, and having a well-balanced heat resistance and curability, as a result, as an epoxy resin curing agent. The inventors have found that a composition using a specific polyhydric phenol meets the above-mentioned object, and completed the present invention.

[0004]

That is, the present invention is
An epoxy resin composition containing (a) an epoxy resin having two or more epoxy groups in the molecule and (b) a polyhydric phenol obtained by condensation of a phenol and a naphthaldehyde as main components. The present invention relates to a resin-encapsulated semiconductor device in which a semiconductor element is encapsulated with the resin and the epoxy resin composition.

Phenols which are raw materials of the polyhydric phenol which is the component (b) used in the present invention include phenol, 1-naphthol or 2-naphthol and chlorine atom, bromine atom or fluorine atom as a substituent. Having a halogen atom, an alkyl group having 1 to 9 carbon atoms or an aryl group, 1-naphthol or 2
Mention may be made of each isomer and derivative of naphthol.

Specifically, phenol, cresol, xylenol, n-propylphenol, isopropylphenol, n-butylphenol, isobutylphenol, t-butylphenol, amylphenol, hexylphenol, cyclohexylphenol, methyl-cyclohexylphenol, methylbutylphenol, Examples thereof include phenylphenol, 1-naphthol, and 2-naphthol (those having isomers include those isomers). These phenols can be used not only alone but also as a mixture of two or more kinds. Among these, cresol and xylenol are particularly preferable from the viewpoint of curability and hygroscopicity.

The naphthaldehydes, which are the other raw material of the polyhydric phenols used in the present invention, are specifically 1-naphthaldehyde, 2-naphthaldehyde, methylnaphthaldehyde, ethylnaphthaldehyde, butylnaphthaldehyde. Can be illustrated. In addition, a halogen atom such as a chlorine atom, a bromine atom or a fluorine atom,
It includes various isomers and derivatives of the above-mentioned naphthaldehyde having an alkyl group or an aryl group having 1 to 9 carbon atoms as a substituent. These naphthaldehydes can be used not only alone but also as a mixture of two or more kinds.

The naphthaldehydes of the present invention may be mixed with other aldehydes to the extent that the effects of the present invention are not impaired. Other aldehydes include formaldehyde, acetaldehyde, benzaldehyde, acrolein, crotonaldehyde, cinnamic aldehyde, glyoxal and the like (including various derivatives).

The condensation reaction between these phenols and naphthaldehydes is carried out by using an inorganic acid such as HCl or H ₂ SO _4, an organic acid such as acetic acid, p-toluenesulfonic acid or thioglycolic acid, or an acidic catalyst such as Lewis acid. Or in the presence of an ion-exchange resin, condensation is performed at a temperature of 40 to 150 ° C., and post-treatment such as washing with water and distilling off unreacted phenols is carried out by a known method. The condensate of phenols and naphthaldehydes thus obtained can be represented by the following general formula (1).

[0010]

[Chemical 1] (In the formula, Ar ₁ is a structure derived from the above phenols,
Ar ₂ also represents a structure derived from the above naphthaldehydes. n is the average number of repeating units. )

The average number of repeating units n can be adjusted by the synthesis conditions such as the molar ratio of the phenols and naphthaldehydes charged and the amount of catalyst. When n is 0, the melting point and melt viscosity of the target product are the lowest, making it easy to handle. However, considering the balance of the physical properties of the cured product, it may be a mixture containing a polyfunctional component with n exceeding 0. If it is from 0 to 3, preferably from 0 to 1.5, the object of the present invention is satisfied. If n exceeds 3, the softening point and melt viscosity of the target product increase, which is difficult to handle, which is not preferable. Further, the unreacted phenols remaining can be used as the polyhydric phenols used in the present invention, or the unreacted phenols are intentionally left for adjusting the softening point and the melt viscosity. It is also possible to adjust and use.

As the epoxy resin which is the component (a) used in the composition of the present invention, known products can be used. For example, phenol, o-
Novolac-based epoxy resin, which is a reaction product of phenol such as cresol and formaldehyde, phloroglysin, tris- (4-hydroxyphenyl) -methane,
Glycidyl ether compounds derived from trihydric or higher phenols such as 1,1,2,2, -tetrakis (4-hydroxyphenyl) ethane, dihydric phenols such as bisphenol A, bisphenol F, hydroquinone and resorcin, or tetra Diglycidyl ether compounds derived from halogenated bisphenols such as brombisphenol A, glycidyl ether compounds of polyhydric phenols obtained by condensation reaction of phenols and aromatic carbonyl compounds, p-aminophenol, m-aminophenol , 4-aminometacresol, 6-aminometacresol, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-
Diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy)
Benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis (4-aminophenoxyphenyl) propane, p-phenylenediamine, m-phenylene Diamine, 2,4-toluenediamine, 2,6-toluenediamine, p-xylylenediamine, m-xylylenediamine, 1,4-cyclohexanebis (methylamine),
Amine-based epoxy resin derived from 1,3-cyclohexanebis (methylamine), p-oxybenzoic acid,
Glycidyl ester compounds derived from aromatic carboxylic acids such as m-oxybenzoic acid, terephthalic acid and isophthalic acid, hydantoin epoxy compounds derived from 5,5-dimethylhydantoin, 2,2-bis (3,2)
4-epoxycyclohexyl) propane, 2,2-bis [4- (2,3-epoxypropyl) cyclohexyl]
Propane, vinylcyclohexenedioxide, 3,4
There are alicyclic epoxy resins such as epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, N, N-diglycidylaniline and the like, and one or more kinds of these epoxy resins are used.

When a bifunctional epoxy resin is used among these epoxy resins, it is preferable that the number of functional groups of the polyhydric phenols to be combined is 3 or more. A combination of a bifunctional epoxy resin and a trifunctional or higher polyhydric phenol has excellent curability when used as a sealing material. From the above reasons and from the viewpoint of moisture resistance, novolac type epoxy resins such as o-cresol novolac and glycidyl ethers of polyhydric phenols obtained by condensation reaction of phenols and aromatic carbonyl compounds are preferable for sealing material applications. .. Of these, novolac type epoxy resin is more preferable.

In the composition of the present invention, an ordinary curing agent for epoxy resin may be used in combination with the polyhydric phenol which is the component (b). Examples of these curing agents include bisphenol A, tetrabromobisphenol A, bisphenol F, bisphenol S, bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) ethane, 1,3,3-trimethyl-1- m-hydroxyphenylindan-5 or 7-ol, 1,
Polyphenol compounds such as 3,3-trimethyl-1-p-hydroxyphenylindan-6-ol, resorcin, hydroquinone, catechol and phenol, phenols such as o-cresol and phenols, which are reaction products of formaldehyde, and novolac resins, Polycarboxylic acids such as maleic acid, phthalic acid, nadic acid, methyl-tetrahydrophthalic acid and methyl nadic acid and their anhydrides, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether, phenylenediamine, diaminodicyclohexylmethane, xylylenediamine, toluenediamine. , Dichloro-diaminodiphenylmethane (including isomers), ethylenediamine, hexamethylenediamine and other polyamine compounds, and further dicyandiene Bromide, tetramethyl guanidine,
Examples thereof include active hydrogen-containing compounds capable of reacting with an epoxy group. Of these, phenolic novolac resins are preferable from the viewpoint of curability.

The blending ratio of the epoxy resin and the polyhydric phenol of the composition of the present invention will be described. The amount of the polyhydric phenol used is 0.7 to 1.2 equivalents based on the epoxy group. If the amount is less than 0.7 equivalent or more than 1.2 equivalent to the epoxy group, curing is incomplete and low hygroscopicity is not obtained.

When curing the resin composition of the present invention, known curing accelerators may be used. In particular, it is desirable to use it in order to obtain fast curing property in the application of semiconductor encapsulating material. Examples of such curing accelerators include organic phosphine compounds such as triphenylphosphine, tri-4-methylphenylphosphine, tri-4-methoxyphenylphosphine, tributylphosphine, trioctylphosphine, tri-2-cyanoethylphosphine, and triphenylphosphine. Tertiary amines such as butylamine, triethylamine, 1,8-diazabicyclo (5,4,0) undecene-7 and triamylamine, quaternary ammonium such as benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide, and triethylammonium tetraphenylborate. Examples thereof include salts and imidazoles, but are not limited to these. Among these, organic phosphine compounds, 1,8-diazabicyclo (5,4,0) undecene-7 and triethylammonium tetraphenylborate are preferable from the viewpoint of moisture resistance and curability, and among them, triphenylphosphine is particularly preferable.

An inorganic filler may be added to the resin composition of the present invention. As the filler, silica,
Alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber and the like can be mentioned, with silica and alumina being particularly preferred. These may be used by increasing the filling amount by mixing those having different shapes (spherical shape or crushed type) or different sizes. When used for sealing a semiconductor, the blending ratio of the inorganic filler is 25 to 90% by weight, preferably 60 to 85% by weight, based on the total amount of the resin composition. If the amount of the filler is less than 25% by weight, the moisture resistance is poor, and if it exceeds 90% by weight, the moldability becomes a problem.

In the composition of the present invention, if necessary, a natural wax, a synthetic wax, a higher fatty acid and its metal salt, a releasing agent such as paraffin or a coloring agent such as carbon black, and a silane coupling agent. You may add surface treatment agents etc. of these. Further, a flame retardant such as antimony trioxide, a phosphorus compound and a brominated epoxy resin may be added. It is particularly preferable to use a brominated epoxy resin in order to obtain a flame retardant effect.

In order to reduce the stress, various elastomers may be added or reacted in advance and used. Specific examples of the elastomer include polybutadiene, butadiene-acrylonitrile copolymer, addition type or reaction type elastomer of silicone rubber, silicone oil and the like. Semiconductors and the like using the resin composition of the present invention,
In order to seal the electronic component and manufacture the resin-sealed semiconductor device, it may be cured and molded by a conventionally known molding method such as transfer molding, compression molding, injection molding or the like.

[0020]

The epoxy resin composition of the present invention has lower hygroscopicity and is well balanced in heat resistance, toughness when heated, and adhesiveness, especially as a sealing material for electronic parts.
Moreover, the resin-sealed semiconductor device using this composition is excellent in solder cracking property.

[0021]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. In the examples, the hydroxyl equivalent is defined as the molecular weight of the resin per hydroxyl group. The average number of repeating units n was determined from GPC (TRIROTOR SR-II manufactured by JASCO Corporation). The evaluation of the kneaded product and the cured molded product is as follows. -Gel thyme The kneaded materials obtained in Examples and Comparative Examples were 1
0.5 g was taken in the concave portion of the hot plate at 80 ° C., and the time until gelation was measured.・ Glass transition temperature thermomechanical analyzer (SHIMADZ
It was measured using UDT-30). -Burcol hardness 93 according to ASTM D-648
It was measured with a type 5 under the condition of 175 ° C./2 minutes. -Hot bending strength, hot bending elastic modulus, hot bending flexure (scale of toughness) Instron universal material testing machine (SHIMADZU IS-10) according to JISK-6911.
T) at 240 ° C. The flexural flexure ratio during heating was calculated from the following formula. Flexural Deflection During Heat = 6 x Sample Thickness x Maximum Deflection /
(Distance between fulcrums) ² (Source: Plastic Test Handbook) -Water Absorption Rate Weight change was measured under the conditions of 85 ° C / 85% RH using a constant temperature and constant humidity chamber (TABAI PR-2).・ Spiral flow 17 according to EMMI-1-66
It was performed under the conditions of 5 ° C./70 kg / cm ² . -Adhesive strength A molded product was transfer-molded on an aluminum foil, and the peel strength was evaluated.・ Solder cracking property Simulated IC (52-pin QFP package: package thickness 2.05 mm) is 85 ℃ / 85
240% immediately after absorbing moisture under the condition of% RH / 72 hours
The number of cracked ICs after immersion in a solder bath at ℃ for 30 seconds. Number of test individuals 10

Reference Example 1 40-5.8 g (3.75 mo) of m-cresol was placed in a four-necked flask equipped with a stirrer, a thermometer and a condenser.
l), 1-naphthaldehyde 78.1 g (0.50 mo
l) Toluene 341 g and p-toluenesulfonic acid
1.33 g of monohydrate was charged and dissolved with stirring. The internal temperature was raised to a reflux temperature of 130 ° C., and water produced by the reaction was distilled off from the reaction system through an azeotropic dehydration tube. The reaction is 1
It was carried out at 30 ° C. for 4 hours. After completion of the reaction, the mixture was neutralized with an aqueous sodium hydroxide solution, 600 g of methyl isobutyl ketone was added, and washing with water and separation of layers were repeated. Then, the organic layer was concentrated by a rotary evaporator to obtain 168.2 g of a target polyhydric phenol (referred to as MCNAN). This product has a softening point of 117.5 ° C. and a hydroxyl equivalent of 183.
g / equivalent, n was 0.31.

Reference Example 2 In Reference Example 1, 405.8 g (3.75 mol) of o-cresol was used instead of m-cresol, and 78.1 g (0.50 mo) of 1-naphthaldehyde was charged.
l) and p-toluenesulfonic acid monohydrate were replaced by 0.95 g, and the same reaction was carried out to obtain 170.0 g of a target polyphenol (referred to as OCNAN). According to the FD-MASS spectrum of this product, 354,6
Fragments 00, 846, 1092, 1338, 1584 were detected. The softening point was 111 ° C., the hydroxyl group equivalent was 181 g / equivalent, and n was 0.14.

Reference Example 3 Bisphenolcyclohexane: Antigen W (trade name, manufactured by Sumitomo Chemical Co., Ltd.) 160.8 was placed in a 1-liter four-necked flask equipped with a stirrer, a thermometer and a condenser.
g (0.6 mol), 1-naphthaldehyde 28.1 g
(0.18 mol), isoamyl alcohol 241.2
g and p-toluenesulfonic acid monohydrate 3.42 g
Was charged and dissolved by stirring. The internal temperature was raised to a reflux temperature of 80 ° C. under a reduced pressure of 70 Torr, and water produced by the reaction was distilled off from the reaction system through an azeotropic dehydration tube. The reaction is
It carried out at 80 degreeC for 6 hours. After completion of the reaction, neutralization and liquid separation with an aqueous solution of sodium hydroxide were followed by washing with water and liquid separation. The organic layer was concentrated by a rotary evaporator to obtain 181.7 g of a target polyphenol (PHCH
NA). However, the hydroxyl group equivalent was 154 g / equivalent, the softening point was 110 ° C., and n was 0.75.

Reference Example 4 115.4 g of 1-naphthol (0.8 g) was placed in a 1 liter four-necked flask equipped with a stirrer, a thermometer and a condenser.
mol), 1-naphthaldehyde 62.4 g (0.4 m
ol), 267 g of toluene, and 1.37 g of p-toluenesulfonic acid monohydrate were charged and dissolved with stirring. The internal temperature was raised to a reflux temperature of 115 ° C., and water produced by the reaction was distilled off from the reaction system through an azeotropic dehydration tube. The reaction was carried out at 115 ° C. for 8 hours. After completion of the reaction, neutralization and liquid separation with an aqueous solution of sodium hydroxide were followed by washing with water and liquid separation. The organic layer was concentrated with a rotary evaporator to obtain 149 g of a target polyhydric phenol (NA
NAN). The softening point of this product was 114 ° C., the hydroxyl equivalent was 216 g / equivalent, and n was 0.39.

Examples 1 to 4 Polyhydric phenols obtained in Reference Examples 1 to 4 above were used as a curing agent, and glycidyl ether of o-cresol novolac was used as an epoxy resin; Sumiepoxy ESCN-
195 (trade name, manufactured by Sumitomo Chemical Co., Ltd .: epoxy equivalent 201 g / equivalent, hydrolyzable chlorine 330 ppm) and glycidyl ether of polyphenol obtained by condensation of phenols and hydroxybenzaldehyde; Sumiepoxy ESX-221 (trade name, Sumitomo Chemical Co., Ltd.
Made: Epoxy equivalent 213 g / equivalent, hydrolyzable chlorine 20
0 ppm), triphenylphosphine as a curing accelerator, fused silica (FS-891 Denki Kagaku Kogyo KK) as a filler, carnauba wax as a release agent, coupling agent (trade name, SH-6040 Toray Dow). Corning Silicone Co., Ltd. was blended in an amount (g) shown in Table 1, kneaded by heating with a roll, and transfer molding was performed (curing time 3 minutes). Further, post-curing was performed in an oven at 180 ° C. for 5 hours to obtain a cured molded product.

Comparative Examples 1-2 Phenol novolac as a curing agent (trade name, Tamanor 759, manufactured by Arakawa Chemical Co., Ltd., OH equivalent 110 g / eq)
A cured molded article was obtained in the same manner as in the example except that was used. The formulation is shown in Table 1.

Gel time, spiral flow, barcol strength, glass transition temperature, water absorption rate, hot bending strength, hot bending elastic modulus of the cured moldings obtained in Examples and Comparative Examples,
The flexural flexure at the time of heating, the adhesive force, and the solder cracking property were measured. The results are shown in Table 2.

[0029]

[Table 1]

[0030]

[Table 2]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Noriaki Saito 6 Kitahara, Tsukuba-shi, Ibaraki, Sumitomo Chemical Co., Ltd. (72) Inventor Takashi Morimoto 6, Kitahara, Tsukuba-shi, Ibaraki, Sumitomo Chemical Co., Ltd.

Claims (4)

[Claims] 1. A main component containing (a) an epoxy resin having two or more epoxy groups in a molecule and (b) a polyhydric phenol obtained by condensation of a phenol and a naphthaldehyde. And an epoxy resin composition. 2. The epoxy resin composition according to claim 1, wherein the epoxy resin is a novolac type epoxy resin. 3. The epoxy resin composition according to claim 1, wherein the polyhydric phenol is a condensate of a monohydric phenol and a naphthaldehyde. 4. A resin-encapsulated semiconductor device, wherein a semiconductor element is encapsulated with the epoxy resin composition according to claim 1.