JPH08269169A - Epoxy resin composition and resin-encapsulated semiconductor device - Google Patents

Abstract

(57) [Abstract] [Purpose] Epoxy resin composition for semiconductor encapsulation that gives a cured product having low viscosity, high heat resistance and high adhesion, and resin-encapsulated semiconductor device using the same, which is excellent in solder crack resistance. To provide. [Structure] (A) General formula (1) (Here, R ₁ and R ₂ represent hydrogen, a chain or cyclic alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group or a halogen atom. A plurality of R ₁ and R ₂ are the same as each other. Or m may be different. M is an integer of 1 to 5 and n is an integer of 2 to 5) and (B) an epoxy resin curing agent are contained as main components. A characteristic epoxy resin composition for semiconductor encapsulation,
The present invention also relates to a resin-encapsulated semiconductor device in which a semiconductor element is encapsulated with the 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 particularly useful for encapsulating electronic parts and a resin encapsulation type 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
Since the sealing material is exposed to a high temperature of 200 ° C. or higher, the moisture absorbed in the encapsulant expands, causing cracks or peeling at the interface with the die pad.

Therefore, the epoxy resin encapsulant is required to have improved low hygroscopicity, crack resistance and 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.
An encapsulant mainly composed of glycidyl ether of 4,4′-dihydroxybenzophenone has a tentative solder crack resistance. However, since it is not always sufficient in the application where a high level of heat resistance is required as described above, there is a problem in solder crack resistance. It is an object of the present invention to provide an epoxy resin composition for semiconductor encapsulation having a lower viscosity, a higher heat resistance and a higher adhesion, and a resin encapsulation type semiconductor device using the same, which has excellent solder crack resistance. .

[0005]

[Means for Solving the Problems] In view of such circumstances,
As a result of intensive studies, the present inventors have found that a specific epoxy resin composition meets the above-mentioned object, and have completed the present invention. That is, the present invention provides (A) general formula (1)

[0006]

Embedded image (Here, R ₁ and R ₂ represent hydrogen, a chain or cyclic alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group or a halogen atom. A plurality of R ₁ and R ₂ are the same as each other. Or m may be different. M is an integer of 1 to 5 and n is an integer of 2 to 5) and (B) an epoxy resin curing agent are contained as main components. A characteristic epoxy resin composition for semiconductor encapsulation,
The present invention also relates to a resin-encapsulated semiconductor device in which a semiconductor element is encapsulated with the epoxy resin composition.

Specific examples of the substituent R ₁ of the epoxy resin which is the component (A) represented by the general formula (1) used in the present invention include methyl group, ethyl group, propyl group, butyl group, and Examples thereof include 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, in the case of obtaining a highly pure product, a method of reacting in an aprotic solvent as described in JP-A-60-31517 is suitable. Phenols used here have the general formula (2)

[0009]

Embedded image (Here, the meanings of R ₁ , R ₂ and m and n are the same as those of the general formula (1).), And specific examples of the phenols represented by the general formula (2) are as follows. Such compounds can be mentioned.

[0010]

[Chemical 4] In the epoxy resin composition of the present invention, the epoxy resin may be used in combination with another epoxy resin as the epoxy resin. As the other epoxy resin, known products can be used, and examples thereof include novolac-based epoxy resins, which are reaction products of phenols such as phenol and o-cresol, and formaldehyde, phloroglysin, and tris-. (4-hydroxyphenyl)-
Glycidyl ether compounds derived from trivalent or higher phenols such as methane and 1,1,2,2-tetrakis (4-hydroxyphenyl) 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 (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-phenylenediamine, 2,4-toluenediamine, 2,6-toluenediamine, p-xylyl Amine-based epoxy resin derived from diamine, m-xylylenediamine, 1,4-cyclohexanebis (methylamine), 1,3-cyclohexanebis (methylamine), p-oxybenzoic acid, m-oxybenzoic acid Acids, glycidyl ester compounds derived from aromatic carboxylic acids such as terephthalic acid and isophthalic acid, 5,5-
Hydantoin-based epoxy compounds derived from dimethylhydantoin, 2,2-bis (3,4-epoxycyclohexyl) propane, 2,2-bis [4- (2,3-
There are alicyclic epoxy resins such as epoxypropyl) cyclohexyl] propane, vinylcyclohexenedioxide, and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and N, N-diglycidylaniline. One type or two or more types of 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 of these include polyphenols such as phenol novolac, dicyandiamide, diaminodiphenylmethane, amine-based curing agents such as diaminodiphenylsulfone, pyromellitic dianhydride, trimellitic anhydride, acid anhydride curing agents such as benzophenonetetracarboxylic acid. From the viewpoint of moisture resistance, polyhydric phenols are preferably used.

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

[0013]

Embedded image Diols such as compounds represented by

[0014]

[Chemical 6] A dialkoxy compound such as a compound represented by or a formula

[0015]

[Chemical 7] The compound is represented by dihalogens, or a Friedel-Crafts type reaction product of phenols and diolefins such as dicyclopentadiene, dipentene, diisopropenylbenzene, etc., but from the viewpoint of workability and curability Phenol novolac is particularly preferred. 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
The component (B) is preferably 0.7 to 1.2 equivalents relative to the epoxy group of the component (A). If the component (B) is less than 0.7 equivalent or more than 1.2 equivalent to the epoxy group, the curing is incomplete in any case.

When curing the resin composition of the present invention, known curing accelerators 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-diazabicyclo (5,4,0) undecene-7, tertiary amines such as triamylamine, quaternary ammonium salts such as benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide, triethylammonium tetraphenylborate, imidazoles, etc. However, the present invention is not limited thereto. 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 among them, triphenylphosphine is particularly preferable.

The inorganic filler which is the component (C) in the epoxy resin composition of the present invention includes silica, alumina, titanium white, aluminum hydroxide, talc,
Examples thereof include clay and glass fiber, and silica and alumina are particularly preferable. These may be used by increasing the filling amount by mixing those having different shapes (spherical shape or crushed type) or different sizes. The blending ratio of the inorganic filler needs to be 25 to 92% by weight, and preferably 70 to 92% by weight, based on the total amount of the resin composition. When the amount of the filler is small, the moisture resistance is inferior, and when it exceeds 92% by weight, there is a problem in moldability. In the present invention, if necessary, a natural wax, a synthetic wax, a higher fatty acid and a metal salt thereof, a release agent such as paraffin or a colorant such as carbon black, and a surface treatment agent such as a silane coupling agent may be added. You may add.
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 thereof 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.

[0019]

The epoxy resin composition of the present invention has high heat resistance, adhesion, etc., as a sealing material for electronic parts, and is well balanced. Moreover, the resin-sealed semiconductor device using this resin composition is excellent in solder crack resistance.

Further, since this composition has a low viscosity as compared with the glycidyl ether of o-cresol novolac, it is possible to add a large amount of the filler, and as compared with the diglycidyl ether of benzophenone, the heat resistance is higher. Etc. have improved, and the reliability of the produced products is high.

[0021]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. In the examples, the epoxy equivalent is defined as the molecular weight of the epoxy resin per epoxy group.

The evaluation method of the kneaded product and the cured molded product is as follows.・ Gel time: 18 with a gelation tester manufactured by Nisshin Chemical Co., Ltd.
The measurement was performed at 0 ° C. Barcol hardness: measured according to ASTM D-648 with a 935 type hardness meter under the condition of 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-1OT) 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 ℃ / 7 according to EMMI-1-66
It was carried out under the condition of 0 kg / cm ² .・ Frame pull-out strength: Copper and 4 as shown in Fig. 1
2 Transfer molding the molded product on the alloy frame,
The pulling strength was evaluated.・ Solder cracking: Simulated IC (52-pin QFP package: package thickness 2.05mm) at 85 ℃ / 85% R
Immediately after absorbing moisture under the condition of H / 72 hours, 240 ° C
With cracks after dipping in the solder bath for 30 seconds
C population. Number of test individuals 8

Reference Example 1 Synthesis of Epoxy Resin-12,4,4'-trihydroxybenzophenone (0.5 m
ol) 115.1 g and epichlorohydrin 15.1 mol (138
7.5 g) was charged into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a condenser with a separating tube. 10 in the reaction system
While maintaining the temperature at 5 ° C, 118 g of 48.3% caustic soda was continuously added dropwise over 2 hours. During this time, while keeping the temperature at 125 ° C., the azeotropically distilled epichlorohydrin and water are cooled and liquefied,
The organic layer was allowed to react while being returned to the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, a by-product salt and glycidyl ether were dissolved in 465 g of methyl isobutyl ketone, and a by-product was removed by washing with water. After that, methyl isobutyl ketone was distilled off under reduced pressure at 170 ° C. and 10 torr to obtain the desired product. This product was liquid at room temperature, had a melt viscosity of 0.40 P (150 ° C.) and an epoxy equivalent of 154 g / eq (referred to as PRCO-E).

Reference Example 2 Synthesis of epoxy resin-2 4,4'-dihydroxybenzophenone (0.5 mol)
104.2 g was charged into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a condenser with a separating tube, and epichlorohydrin 7.19 mol (661.2 g), dimethyl sulfoxide 255.
It dissolved in 2 g. While maintaining the reaction system at 43 torr, 68.33 g of 48.3% caustic soda was continuously added dropwise at a temperature of 48 ° C 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 the reaction was completed, unreacted epichlorohydrin was removed by vacuum concentration, and glycidyl ether containing a by-product salt and dimethyl sulfoxide was dissolved in 676 g of methyl isobutyl ketone.
The by-product salt and dimethyl sulfoxide were removed by washing with water.
After that, methyl isobutyl ketone was distilled off under reduced pressure at 170 ° C. and 10 torr to obtain the desired product. This product has a melting point of 13
The temperature was 2 ° C., the melt viscosity was 0.12 P (150 ° C.), and the epoxy equivalent was 175 g / eq (PPPP-E).

Examples 1 to 3 and Comparative Examples 1 and 2 Glycidyl ethers obtained in Reference Examples 1 and 2, o-cresol novolac glycidyl ether (trade name: Sumiepoxy ESCN-195, manufactured by Sumitomo Chemical Co., Ltd.) as a curing agent. Phenol novolac (trade name PSM-4261, manufactured by Gunei Chemical Industry Co., Ltd.), triphenylphosphine as a curing accelerator, fused silica (silica grade is shown below) as a filler, carnauba wax as a release agent, coupling agent ( Trade names SH-6040 and SH-6026, manufactured by Toray Dow Corning Silicone) were compounded in the amounts (g) shown in Table 1, and the mixture was heated and kneaded with a roll and transfer molding was performed. In addition, 1
Post-curing was performed for 5 hours in an 80 ° C. oven to obtain a cured molded product. The physical properties of this cured molded product were measured. Table 1 shows the results. Fused silica grade FS-20: Fractured silica (average particle size 5.6 μm) Denka Kagaku Kogyo Co., Ltd. Admafine SOC-2: Spherical silica (average particle size 0.4 μm)
m) Admatech Silstar MK-06: Spherical silica (average particle size 4.9 μm) Nippon Kagaku Kogyo Co., Ltd. Excelica SE-40: Spherical silica (average particle size 40.4 μm) Tokuyama Soda Co., Ltd.

[0026]

[Table 1]

[Brief description of drawings]

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

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

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 23/29 H01L 23/30 23/31

Claims (4)

[Claims] 1. (A) General formula (1): (Here, R ₁ and R ₂ represent hydrogen, a chain or cyclic alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group or a halogen atom. A plurality of R ₁ and R ₂ are the same as each other. Or m may be different. M is an integer of 1 to 5 and n is an integer of 2 to 5) and (B) an epoxy resin curing agent are contained as essential components. A characteristic epoxy resin composition for semiconductor encapsulation. 2. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the epoxy resin curing agent as the component (B) is a polyhydric phenol. 3. In addition to the components (A) and (B), (C)
The epoxy resin composition for semiconductor encapsulation according to claim 1 or 2, comprising an inorganic filler. 4. A resin-encapsulated semiconductor device, which is obtained by encapsulating a semiconductor element using the epoxy resin composition according to claim 1.