JPH09100339A - Epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition which is lowly viscous, can give a cured product having low hygroscopicity and high adhesion and is useful for sealing especially electronic components by using a specified epoxy resin. SOLUTION: This epoxy resin composition essentially consists of an epoxy resin represented by formula I (wherein R1 is H, a 1-6C acyclic or cyclic alkyl, a (substituted) phenyl or a halogen; X is a group of formula II, III, IV or V; and (n) is 0-4) and an epoxy resin curing agent. This epoxy resin is obtained by reacting a phenol with an epihalohydrin in the presence of an alkali. The epoxy resin curing agent used is desirably a polyhydric phenol. The amount of the epoxy resin curing agent used is usually desirably 0.7-1.2 equivalents per equivalent of the epoxy groups. This composition desirably contains 25-92wt.%, based on the entire resin composition, inorganic filler.

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, which is particularly 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 of an economically useful epoxy resin composition is performed for sealing a semiconductor. In particular, recently, surface mounting of LSIs has been carried out, and the number of cases in which they are directly immersed in a solder bath is increasing. At that time, the sealing material is 20
Since the sealant is exposed to a high temperature of 0 ° C. or higher, the moisture absorbed in the encapsulant expands, causing cracks or peeling at the interface with the die pad.

[0003] For this reason, epoxy resin sealing materials are required to have low hygroscopicity, crack resistance and improved adhesion. Further, for the purpose of obtaining low hygroscopicity, a low-viscosity epoxy resin that can be filled with a filler at a high density is desired. At present, a sealant using glycidyl ether of o-cresol novolac as the epoxy resin and phenol novolac as the curing agent is the mainstream, but there is the above problem when moisture is absorbed during storage, and in order to avoid this, practically Is used in a moisture-proof package.

[0004]

The encapsulant mainly composed of glycidyl ether of o-cresol novolac has a good balance in terms of heat resistance and moldability, but at the high level as described above. There is a problem in solder cracking properties because it is not always sufficient in applications where low hygroscopicity is required. An object of the present invention is to provide an epoxy resin composition that gives a cured product having low viscosity, low hygroscopicity, and high adhesion, and a resin-encapsulated semiconductor device using the same.

[0005]

In view of the above circumstances, the inventors of the present invention have conducted extensive studies and, as a result, have found that a specific epoxy resin composition is suitable for the above purpose and completed the present invention. That is, the present invention provides (A) general formula (1)

[0006]

Embedded image (In the formula, R ₁ represents a hydrogen atom, a chain or cyclic alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group or a halogen atom, and R ₁ may be the same or different from each other. Good, and X is an expression

Embedded image Is a group represented by n shows the integer value of 0-4. ) An epoxy resin composition containing an epoxy resin represented by the formula (4) and a curing agent as main components, and a resin-encapsulated mold characterized by encapsulating a semiconductor element using the epoxy resin composition. The present invention relates to a semiconductor device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The general formula (1) used in the present invention
Substituent R ₁ of the epoxy resin which is the component (A) represented by
When specifically exemplified, a methyl group, an ethyl group,
Examples thereof include a propyl group, a butyl group, an amyl group, a hexyl group, a cyclohexyl group, a phenyl group, a tolyl group, a xylyl group (including each isomer), a chlorine atom and a bromine atom.

The epoxy resin used in the present invention can be obtained by a well-known method of glycidyl etherifying phenols. That is, it is a method of reacting phenols with epihalohydrin in the presence of an alkali such as caustic soda. In particular, when a highly pure product is obtained, the reaction in an aprotic solvent is suitable as in the method described in JP-A-60-31517.

The phenols used here are represented by the general formula (2)

Embedded image (In the formula, the meanings of R ₁ , X and n are the same as those of the general formula (1).) As specific examples of the phenols represented by the general formula (2), the following compounds can be mentioned. Can be given.

[0010]

Embedded image

[0011]

Embedded image

In the composition of the present invention, the epoxy resin may be used in combination with the other epoxy resin. As these epoxy resins, known ones can be used, but if these are exemplified,
Novolac-based epoxy resin, which is a reaction product of phenols such as phenol and o-cresol, with formaldehyde, phloroglysin, tris- (4-hydroxyphenyl) -methane, 1,1,2,2, -tetrakis (4-hydroxy) Glycidyl ether compound derived from trivalent or higher phenols such as phenyl) ethane, bisphenol A,
Dihydric phenols such as bisphenol F, tetramethylbiphenol, hydroquinone, resorcin, 4,4′-thiodi (2,6-dimethylphenol), dihydroxynaphthalene, bis (hydroxyphenyl) dicyclopentane and bis (hydroxyphenyl) menthane Or a diglycidyl ether compound derived from halogenated bisphenols such as tetrabromobisphenol 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 ( Four
-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-phenylenediamine, 2,4-toluenediamine, 2,6-toluenediamine, p-xylylenediamine, m-xylylenediamine, 1,4-cyclohexane From amine-based epoxy resins derived from bis (methylamine), 1,3-cyclohexanebis (methylamine), etc., aromatic carboxylic acids such as p-oxybenzoic acid, m-oxybenzoic acid, terephthalic acid, isophthalic acid, etc. Derived glycidyl ester compounds, hydantoin epoxy compounds derived from 5,5-dimethylhydantoin, etc., 2 , 2-bis (3,4
-Epoxycyclohexyl) propane, 2,2-bis [4
Alicyclic epoxy resin such as-(2,3-epoxypropyl) cyclohexyl] propane, vinylcyclohexenedioxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, N, N-
There is diglycidyl aniline and the like, and one or more of these epoxy resins are used.

As the epoxy resin curing agent which is the component (B) used in the present invention, known ones can be used. Examples thereof include polyphenols such as phenol novolak, amine-based curing agents such as dicyandiamide, diaminodiphenylmethane, diaminodiphenylsulfone, and acid anhydride curing agents such as pyromellitic anhydride, trimellitic anhydride, and benzophenonetetracarboxylic acid. Although polyhydric phenols are preferably used from the viewpoint of moisture resistance.

To further exemplify the above-mentioned polyhydric phenols, one or more phenols such as phenol, various alkylphenols and naphthol, and formaldehyde, acetaldehyde, acrolein, glyoxal, benzaldehyde, naphthaldehyde, hydroxybenzaldehyde and the like can be mentioned. Polycondensates with aldehydes or ketones such as cyclohexanone and acetophenone, vinyl-polymerized polyphenols such as polyvinylphenol and polyisopropenylphenol, and phenols and formulas

[0015]

Embedded image Diols such as compounds represented by

[0016]

Embedded image A dialkoxy compound such as a compound represented by or a formula

[0017]

Embedded image The compound is a Friedel-Crafts type reaction product of a dihalogen such as a compound or a phenol with a diolefin such as dicyclopentadiene or diisopropenylbenzene, but from the viewpoint of workability and curability, phenol novolak Is particularly preferable. In addition, these curing agents may be used alone or in combination of two or more.

The mixing ratio of the epoxy resin as the component (A) and the curing agent for the epoxy resin as the component (B) is usually preferably 0.7 to 1.2 equivalents relative to the epoxy group. If the amount is less than 0.7 equivalent or more than 1.2 equivalent to the epoxy group, the curing will be incomplete.

When curing the resin composition of the present invention, a known curing accelerator may be used. Examples of such a curing accelerator include triphenylphosphine and tri-
Organic phosphine compounds such as 4-methylphenylphosphine, tri-4-methoxyphenylphosphine, tributylphosphine, trioctylphosphine and tri-2-cyanoethylphosphine and their tetraphenylborate salts, tributylamine, triethylamine, 1,8
Examples include tertiary amines such as diazabicyclo (5,4,0) undecene-7, triamylamine, quaternary ammonium salts such as benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide, triethylammonium tetraphenylborate, and imidazoles. However, the present invention is not limited to these. Among these, organic phosphine compounds, 1,8-diazabicyclo (5,4,0) undecene-7, and imidazoles are preferable from the viewpoint of moisture resistance and curability, and triphenylphosphine is particularly preferable.

Further, (C) in the resin composition of the present invention
As the inorganic filler as a component, silica, alumina, titanium white, aluminum hydroxide, talc, clay,
Examples thereof include glass fiber, and silica and alumina are particularly preferable. These are their shapes (spherical or crushed),
Alternatively, different sizes may be mixed to increase the filling amount and used. The blending ratio of the inorganic filler is preferably 25 to 92% by weight, and more preferably 70 to 92% by weight based on the total amount of the resin composition. When the amount of the filler is less than 70% by weight, the moisture resistance is poor, and when it exceeds 92% by weight, the moldability becomes a problem. In the present invention, if necessary, a release agent such as natural wax, synthetic wax, higher fatty acid and metal salts thereof, or paraffin or a coloring agent such as carbon black, and a surface treatment agent such as a silane coupling agent, etc. May be added. Further, a flame retardant such as antimony trioxide, a phosphorus compound, and a brominated epoxy resin may be added. A brominated epoxy resin is particularly preferable for producing a flame retardant effect. Further, in order to reduce the stress, various elastomers may be added or reacted in advance and used. Specific examples include addition-type or reaction-type elastomers such as polybutadiene, butadiene-acrylonitrile copolymer, silicone rubber, and silicone oil. In order to produce a resin-encapsulated semiconductor device by encapsulating an electronic component such as a semiconductor using the resin composition according to the present invention, curing molding by a conventionally known molding method such as transfer molding, compression molding, injection molding, etc. do it.

[0021]

The epoxy resin composition of the present invention gives a cured product having low viscosity, low hygroscopicity and high adhesion. Moreover, the resin-sealed semiconductor device using this resin composition is excellent in solder crack resistance.

Since this composition has a lower viscosity than glycidyl ether of o-cresol novolac, it is possible to add a large amount of filler, the hygroscopicity is improved, and the reliability of the produced product is also increased. be able to.

[0023]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In the examples, the epoxy equivalent is defined as the molecular weight of the epoxy resin per epoxy group. Further, with hydrolyzable chlorine, an epoxy resin is dissolved in dioxane, an alcohol solution of potassium hydroxide is added, and chlorine ions desorbed when heated for 30 minutes under reflux are back-titrated with an aqueous silver nitrate solution, Ppm in compound
It is represented by

The kneaded product and the cured molded product are evaluated as follows.・ Gel time: 18 with a gelation tester manufactured by Nisshin Chemical Co., Ltd.
The measurement was performed at 0 ° C. -Burcol hardness: measured according to ASTM D-648 with a 935 type hardness meter at 175 ° C / 90 seconds.・ Glass transition temperature: Thermomechanical analyzer (SHIMADZU DT-3
0). Bending strength and flexural modulus: Measured with a tensile tester (SHIMADZU IS-10T) according to JIS K-6911.・ Moisture absorption rate: Constant temperature and humidity chamber (Advantech Toyo AGX-326)
Was used to measure the weight change under the conditions of 85 ° C./85% RH.・ Spiral flow: 175 ℃ / 70kg / according to EMMI-1-66
It was carried out under the conditions of cm ^2.・ Frame pull-out strength: Copper and 42 as shown in FIG.
The molded product was transfer-molded on the alloy frame, and the pulling strength was evaluated.・ Solder cracking: Simulated IC (52-pin QFP package:
The number of ICs with cracks after the package thickness (2.05mm) was made to absorb moisture under the conditions of 85 ° C / 85% RH / 72 hours and immediately immersed in a solder bath at 240 ° C for 30 seconds. Number of test individuals 8
Pieces.

Reference Example 1 Synthesis of Raw Material Phenol A p-hydroxyacetophenone 136.2 was placed in a 3 liter four-necked flask equipped with a thermometer, a stirrer and a condenser.
g (1.0 mol), p-hydroxybenzaldehyde 122.1 g (1.0 mol) and methanol 600
g was charged and dissolved. 97% H ₂ SO ₂ 51.0 g
(0.50 mol) was added, the temperature was raised to 60 ° C., the reaction was carried out at this temperature for 13 hours, and then the reaction solution was poured into 2400 g of water,
Crystallized. The crystals were filtered off, washed with 1000 g of water four times,
Then vacuum dried at 80 ° C. for 5 hours to give reddish brown crystals 210
g was obtained (denoted as DHCNP). The melting point of this product is DS
It was 164 degreeC by C measurement.

Reference Example 2 Synthesis of Raw Material Phenol A 3 liter four-necked flask was charged with 136.2 g (1.0 mol) of m-hydroxyacetophenone, 122.1 g (1.0 mol) of p-hydroxybenzaldehyde and 640 g of methanol and dissolved. . 97% H2 SO
After adding 451.0 g (0.50 mol), the temperature was raised to 60 ° C., and after reacting at this temperature for 10 hours, the reaction solution was added with water (2400).
It was poured into g and crystallized. After separating the crystals by filtration, 1000 g of water
It was washed with water 4 times, and then vacuum dried at 80 ° C. for 5 hours to obtain 164 g of reddish brown crystals (designated as DHCNM). The melting point of this product was 181 ° C. according to DSC measurement.

Reference Example 3 Synthesis of raw material phenol In a 3 liter four-necked flask, 122.1 g (1.0 mol) of p-hydroxybenzaldehyde, 49.1 g (0.5 mol) of cyclohexanone and 400 ethanol.
g was charged and dissolved. 36% hydrochloric acid 50.8 g (0.5
(mol) was added, the temperature was raised to 80 ° C. and the reaction was performed for 6 hours.
The crystals precipitated by the reaction were separated by filtration, washed with 1000 g of water four times, and then vacuum dried at 80 ° C. for 5 hours to obtain 132.0 g of brown crystals (referred to as DHCH).

Reference Example 4 Synthesis of Epoxy Resin 120.0 g of phenol DHCNP obtained in Reference Example 1
Was charged into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a condenser with a separation tube, and epichlorohydrin 64 was charged.
It was dissolved in 7.5 g and 323.8 g of dimethyl sulfoxide. While keeping the reaction system at 43 torr, the temperature is 48 ° C.
Then, 82.82 g of 48.3% caustic soda was continuously added dropwise over 5 hours. During this period, while keeping the temperature at 48 ° C., the azeotropically distilled epichlorohydrin and water were cooled and liquefied, and the reaction was carried out while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, glycidyl ether containing a by-product salt and dimethyl sulfoxide was dissolved in 413 g of methyl isobutyl ketone, and the by-product salt and dimethyl sulfoxide were removed by washing with water. Then 17
Methyl isobutyl ketone was distilled off under reduced pressure at 0 ° C. and 10 torr to obtain the desired product (designated as DHCAP-E). This product has a melting point of 106 ° C and a melt viscosity of 0.22P (150
C.) and the epoxy equivalent was 190 g / eq.

Reference Example 5 Synthesis of Epoxy Resin Phenol obtained in Reference Example 2, DHCNM120.0
g into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a condenser with a separation tube, and epichlorohydrin 64
It was dissolved in 7.5 g and 323.8 g of dimethyl sulfoxide. While keeping the reaction system at 43 torr, the temperature is 48 ° C.
Then, 82.82 g of 48.3% caustic soda was continuously added dropwise over 5 hours. During this period, while keeping the temperature at 48 ° C., the azeotropically distilled epichlorohydrin and water were cooled and liquefied, and the reaction was carried out while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, glycidyl ether containing a by-product salt and dimethyl sulfoxide was dissolved in 413 g of methyl isobutyl ketone, and the by-product salt and dimethyl sulfoxide were removed by washing with water. Then 17
Methyl isobutyl ketone was distilled off under reduced pressure at 0 ° C. and 10 torr to obtain the target product (designated as DHCAM-E). It is liquid at room temperature and has a viscosity of 0.42 at 150 ° C.
P and epoxy equivalent were 186 g / eq.

Reference Example 6 Synthesis of Epoxy Resin 120.0 g of DHCH obtained in Reference Example 3 was charged into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a condenser with a separating tube, and epichlorohydrin 507.3 g and dimethyl sulfoxide 253. It was dissolved in 7 g. While maintaining the inside of the reaction system at 43 torr, at a temperature of 48 ° C., 48.3%
64.88 g of caustic soda was continuously added dropwise over 5 hours.
During this period, while keeping the temperature at 48 ° C., the azeotropically distilled epichlorohydrin and water were cooled and liquefied, and the reaction was carried out while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, and by-product salt and dimethyl sulfoxide were removed by washing with water. After that 170 ℃, 10
Methyl isobutyl ketone was distilled off under reduced pressure at torr to obtain the desired product (designated as DHCH-E). Its melting point is 1
The temperature was 25 ° C., the melt viscosity was 0.33 P (150 ° C.), and the epoxy equivalent was 224.6 g / eq. The structure of DHCH-E is shown below.

[0031]

Embedded image

Examples 1 to 5 and Comparative Examples 1 to 2 Various glycidyl ethers obtained in Reference Examples 4, 5 and 6, o-cresol novolac glycidyl ether (trade name: Sumiepoxy ESCN-195, manufactured by Sumitomo Chemical Co., Ltd., melt viscosity 2.6P (150 ° C.), softening point 65.6 ° C., epoxy equivalent 195 g / eq, phenol novolac (trade name PSM-4261, manufactured by Gunei Chemical Industry Co., Ltd.) as a curing agent,
(Softening point 81 ° C.), triphenylphosphine as a curing accelerator, fused silica as a filler (the content of each trade name is shown below), carnauba wax as a release agent, coupling agent (trade name SH-6040, Toray Dow) Corning Silicone) was blended in the amount (g) shown in Table 1, heated and kneaded with a roll, and then transfer molded. Further, post-curing was performed in an oven at 180 ° C. for 5 hours to obtain a cured molded product. The physical properties of the cured molded product were measured. Table 1 shows the results. The content of each trade name of fused silica is as follows. FS-891: Fractured silica (average particle size 13 μm), manufactured by Denki Kagaku Kogyo FS-20: Fractured silica (average particle size 5.6 μm), Denki Kagaku Kogyo FB-74: Spherical silica (Average particle size 30 μm), manufactured by Denki Kagaku Co., Ltd. Admafine SOC-2: Spherical silica (average particle size 0.4 μm
m), manufactured by Admatech Co., Ltd. Sylstar MK-06: Spherical silica (average particle size 4.9μ)
m), Nippon Kagaku Kogyo Co., Ltd. Excelica SE-40: Spherical silica (average particle size 40.4 μm), manufactured by Tokuyama Soda Co., Ltd.

[0033]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a plan view of a pull-out strength measuring frame.

[Explanation of reference numerals] 1: Place where a resin cured product is formed (hatched portion) 2: Extraction piece 3, 4: Holding part for performing extraction operation

Front Page Continuation (72) Inventor Noriaki Saito 6 Kitahara, Tsukuba City, Ibaraki Prefecture Sumitomo Chemical Co., Ltd.

Claims (4)

[Claims] (A) General formula (1) (In the formula, R ₁ represents a hydrogen atom, a chain or cyclic alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group or a halogen atom, and when R ₁ is plural in the same or different rings, They may be the same or different from each other, and X is of the formula Is a group represented by n shows the integer value of 0-4. ) An epoxy resin composition comprising an epoxy resin represented by the formula (4) and an epoxy resin curing agent (B) as essential components. 2. The epoxy resin composition according to claim 1, wherein the epoxy resin curing agent as the component (B) is a polyphenol. 3. The epoxy resin composition according to claim 1, which further comprises (C) an inorganic filler in addition to the components (A) and (B). 4. A resin-encapsulated semiconductor device in which a semiconductor element is encapsulated with the epoxy resin composition according to claim 1.