JPH06179736A - Liquid epoxy resin composition for sealing semiconductor and its production - Google Patents

Abstract

(57) [Summary] (Modified) [Structure] Epoxy resin (A), curing agent (B), filler (C), silane coupling agent (D) and solvent (E)
A liquid epoxy resin composition comprising: the epoxy resin (A), wherein the epoxy resin (A) is a biphenyl type epoxy resin (a).
As an essential component, the curing agent (B) contains a biphenol compound (b) as an essential component, and the solvent (E) is 5 to 30 wt% of the entire liquid epoxy resin composition.
The residual component accounts for 70 to 95% by weight, the proportion of the filler (C) is 75 to 95% by weight of the residual component, and the proportion of the silane coupling agent (D) is the residual component. A liquid epoxy resin composition for semiconductor encapsulation of 0.3 to 3.0% by weight and a method for producing the same. [Effect] It is excellent in moist heat resistance, temperature cycle resistance reliability and workability, especially in preventing sedimentation of solids.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid epoxy resin composition for semiconductor encapsulation, which is excellent in workability, reliability in humidity and heat resistance after mounting, and reliability in temperature cycle resistance, and a method for producing the same.

[0002]

2. Description of the Related Art As a method for sealing electronic circuit parts such as semiconductor devices, hermetic sealing using metal or ceramics and resin sealing using phenol resin, silicone resin, epoxy resin or the like have been proposed. Above all,
Epoxy resin encapsulation by transfer molding is the main focus from the standpoint of balancing economic efficiency, productivity, and physical properties.
On the other hand, recently, electronic wrist watches, cameras, calculators, IC cards,
As electronic devices such as word processors and LCD TVs are becoming lighter, thinner, smaller, smaller, and more sophisticated, the packaging of semiconductor elements, which is the core of the products, is changing.

The film carrier (TAB) mounting method is as follows.
This is in line with the trend of increasing the number of terminals of semiconductor elements and increasing the density of mounting, and is used for mounting in the above products,
Future expansion is expected. One of the reasons why the TAB mounting method has been recognized as being useful in various applications, but has been delayed in full-scale use in memory applications, etc.
The reason is that the AB sealing resin has not yet been provided to the market.

The reason why the reliability of the liquid encapsulating material for TAB is inferior to that of the encapsulating material for transfer molding is that there is a limit to the combination of resin and solvent that can be used as the liquid encapsulating material, and the temperature cycle resistance. Due to manufacturing method problems such as high concentration of inorganic filler that is effective in improving reliability and difficulty in good dispersion, liquid encapsulation is used in the component composition of transfer molding encapsulation material that has excellent reliability. It is difficult to make it into a material.

Conventionally, as liquid encapsulating materials for TAB, an epibis type epoxy resin, an organic silicon compound having three methoxy groups in one molecule, a resol type phenol resin curing agent, an organic pigment or an inorganic pigment and an organic solvent are used. Liquid epoxy resin as a component has been proposed (Japanese Patent Publication No. 1-36).
984). Further, in the method for producing the liquid sealing material for TAB, the resin component is dissolved or dispersed in a solvent, and then other components such as an inorganic filler are blended to prepare a kneader, a planetary mixer, a three-roll roll, a uniaxial or A known method of kneading using a twin-screw extruder is used.

[0006]

The semiconductor element encapsulated by the encapsulant based on these prior arts is more reliable than the semiconductor element encapsulated by the encapsulant for transfer molding. Although it is inferior, it has already been put to practical use in the field of consumer products such as calculators and liquid crystal displays, where the reliability requirements are not as severe as for memory applications.

However, in order for the TAB encapsulant to be widely used in industrial fields including memory applications, it is necessary to develop a TAB liquid encapsulant having higher reliability. .

The object of the present invention is to have the same level of moisture and heat resistance and temperature cycle reliability as the encapsulating resin for transfer molding, and to suppress the sedimentation of the composition during storage, and to apply the composition by a dispenser. A liquid epoxy resin composition for TAB having excellent properties and a method for producing the same.

[0009]

Means for Solving the Problems The present inventors have further improved reliability in comparison with conventionally proposed encapsulating materials for TAB, and suppress the precipitation of the composition during storage. In order to obtain a novel liquid encapsulating material for TAB which is excellent in coating workability with a dispenser, as a result of intensive studies, the present invention described below was achieved.

That is, the present invention relates to an epoxy resin (A),
A liquid epoxy resin composition comprising a curing agent (B), a filler (C), a silane coupling agent (D) and a solvent (E), wherein the epoxy resin (A) is represented by the following general formula ( I)

[Chemical 4] (In the formula, R ^{1 to} R ⁸ represent a hydrogen atom, a halogen atom or a C _{1 to} C ₄ lower alkyl group.) The biphenyl type epoxy resin (a) represented by The agent (B) has the following general formula (II)

[Chemical 5] (However, in the formula, R ^{9 to} R ¹⁶ are hydrogen atoms, or C _{1 to} C ₄
Is a lower alkyl group. ) Contains a biphenol compound (b) as an essential component, and the solvent (E) accounts for 5 to 30% by weight of the entire liquid epoxy resin composition,
The residual component accounts for 70 to 95% by weight, and the proportion of the filler (C) is 75 to 95% by weight of the residual component,
A liquid epoxy resin composition for semiconductor encapsulation, wherein the ratio of the silane coupling agent (D) is 0.3 to 3.0% by weight of the remaining component, and the present invention further provides the silane coupling agent (D). And the epoxy resin (A) and the curing agent (B) treated with the above are kneaded under the condition that the epoxy resin (A) and the curing agent (B) exist in a molten state. A semiconductor encapsulation characterized in that after a mixture containing a product obtained by partially reacting a resin (A) with the curing agent (B) is obtained, the solvent (E) is added and further kneaded to liquefy. A method for producing a liquid epoxy resin composition for use.

The present invention will be described in detail below.

It is important that the epoxy resin (A) in the present invention contains the biphenyl type epoxy resin (a) represented by the above formula (I) as an essential component. When the biphenyl type epoxy resin (a) is not contained, the wet heat resistance and the temperature cycle resistance are inferior.

In the above formula (I), preferred examples of R ^{1 to} R ⁸ are hydrogen atom, chlorine atom, bromine atom,
Examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group and a tert-butyl group.

Preferred specific examples of the epoxy resin (a) in the present invention include 4,4'-bis (2,3-epoxypropoxy) biphenyl and 4,4'-bis (2,3-).
Epoxypropoxy) -3,3 ', 5,5'-tetramethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3', 5,5'-tetramethyl-2-
Chlorobiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetramethyl-2
-Bromobiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetraethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-Tetrabutylbiphenyl and the like are mentioned, and 4,4′-bis (2,3-epoxypropoxy) biphenyl, 4,4′-bis (2,3-epoxypropoxy) -3,3 ′ , 5,5'-Tetramethylbiphenyl is particularly preferred.

The epoxy resin (A) in the present invention may contain an epoxy resin other than the biphenyl type epoxy resin (a) in combination with the above biphenyl type epoxy resin (a). Other epoxy resins that can be used in combination include, for example, cresol novolac type epoxy resins, phenol novolac type epoxy resins, various novolac type epoxy resins synthesized from bisphenol A and resorcin, bisphenol A type epoxy resins,
Examples thereof include linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, halogenated epoxy resin and the like.

In the present invention, the biphenyl type epoxy resin (a) is contained in the epoxy resin (A) in an amount of 50 to 100% by weight, preferably 70 to 100% by weight.

In the present invention, the compounding amount of the epoxy resin (A) is usually 4 to 20% by weight, preferably 6 to 18% by weight, of the remaining components excluding the solvent (E) from the entire liquid epoxy resin composition. is there.

It is important that the curing agent (B) in the present invention contains the biphenol compound (b) represented by the following formula (II) as an essential component. When the biphenol compound (b) is not contained, the moist heat resistance and temperature cycle resistance are inferior.

The curing agent (B) in the present invention is preferably used in combination with a polyfunctional curing agent other than the above biphenol compound (b). As a curing agent that can be used in combination,
For example, phenol novolac resin, cresol novolac resin, various novolac resins synthesized from bisphenol A and resorcin, the following general formula (III)

[Chemical 6] (In the formula, n is an integer of 0 or 1 or more, R ^{17 to} R ²³ are hydrogen atoms, aryl groups or C _{1 to} C ₄ lower alkyl groups.) A polyphenol compound having a skeleton (b ′), Maleic anhydride, pyromellitic dianhydride,
Examples thereof include acid anhydrides such as phthalic anhydride, and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone. Among them, phenol novolac resin,
The polyphenol compound (b ') is preferable, and the polyphenol compound (b') is particularly preferable.

The ratio of the biphenol compound (b) contained in the curing agent (B) is not particularly limited, and if the biphenol compound (b) is contained as an essential component, good wet heat resistance and temperature cycle resistance can be obtained. Although the reliability is obtained, the biphenol compound (b) is usually contained in the curing agent (B) in an amount of 5 to 90% by weight, and preferably 15 to 50, in order to obtain more excellent reliability in moist heat and temperature cycle.
It is necessary to contain it by weight%.

In the present invention, the compounding amount of the curing agent (B) is usually such that the total amount of the liquid epoxy resin composition is the solvent (E).
1 to 20% by weight of the remaining components excluding
It is 5% by weight. Furthermore, the compounding ratio of the epoxy resin (A) and the curing agent (B) is usually 0.5 to 0.5 hydroxyl groups per epoxy group from the viewpoint of mechanical properties, reliability against moist heat and temperature cycle reliability. 1.5, especially 0.8-
It is preferably in the range of 1.2.

Further, in the present invention, the epoxy resin (A)
A curing catalyst may be used to accelerate the curing reaction of the curing agent (B). The curing catalyst is not particularly limited as long as it accelerates the curing reaction, and for example, 2-methylimidazole, 2
-Imidazole compounds such as phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-
3 such as diazabicyclo (5,4,0) undecene-7
Primary amine compounds, triphenylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine,
Examples thereof include organic phosphine compounds such as tri (nonylphenyl) phosphine, triphenylphosphine / triphenylborane, and tetraphenylphosphonium / tetraphenylborate. Above all, from the viewpoint of moist heat resistance,
Organic phosphine compounds are preferable, and triphenylphosphine and tetraphenylphosphonium tetraphenylborate are particularly preferable.

Two or more kinds of these curing catalysts may be used in combination depending on the use, and the addition amount thereof is the epoxy resin (A).
The range of 0.1 to 10 parts by weight is preferable with respect to 100 parts by weight. Examples of the filler (C) in the present invention include fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, asbestos and glass fiber. Among them, fused silica has a large effect of lowering the coefficient of linear expansion and is effective in lowering stress, and is therefore preferably used.

In the present invention, the compounding amount of the filler (C) is usually from the entire liquid epoxy resin composition to the solvent (E).
It is necessary that the content is 75 to 95% by weight of the remaining components excluding. The filler (C) is particularly preferably spherical fused silica having an average particle size of 20 μm or less from the viewpoint of temperature cycle resistance reliability. Here, the average particle size is a cumulative weight of 50.
It means the particle size (median) in%.

In the present invention, the surface treatment of the filler (C) with the silane coupling agent (E) is preferable from the viewpoint of dispersion stability and reliability of the filler (C). Epoxy silane as the silane coupling agent,
Aminosilane, mercaptosilane, etc. can be used,
γ-anilinopropyltrimethoxysilane, γ- (2-
Aminoethyl) aminopropyltrimethoxysilane, γ
It is particularly preferable to use one kind or a mixture of two or more kinds of-(2-aminoethyl) aminopropylmethyldimethoxysilane.

The amount of the silane coupling agent (E) used is
Usually, it is necessary to be 0.3 to 3.0% by weight of the residual component excluding the solvent (E) from the entire liquid epoxy resin composition. The amount of silane coupling agent (E) used is 0.3
If it is less than 3.0%, the dispersion stability and reliability of the filler (C) are inferior, and if it is used in excess of 3.0%, the effect does not change.

Solvent (E) that can be used in the present invention
Can be selected from a wide range in consideration of the application method and curing conditions of the liquid epoxy resin composition to be finally obtained. Examples of preferably used include, but are not limited to, methyl cellosolve, ethyl cellosolve, ethyl carbitol, γ-butyl lactone, xylene, toluene, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol, and the like. is not.

The solvent (E) accounts for 5 to 30% by weight of the entire liquid epoxy resin composition. When it is less than 5%, the viscosity of the liquid epoxy resin composition becomes too high, and when it is more than 30%, the viscosity of the liquid epoxy resin composition becomes too low, resulting in poor workability in any case.

In the liquid epoxy resin composition of the present invention, a halogen compound such as a halogenated epoxy resin, a flame retardant such as a phosphorus compound, a flame retardant aid such as antimony trioxide, carbon black, iron oxide and the like, if necessary. Functionalizing agents such as colorants can be added as appropriate.

In producing the liquid epoxy resin composition of the present invention, first, the filler (C) treated with the silane coupling agent (D), the epoxy resin (A) and the curing agent (B) are epoxy. It is important to knead the resin (A) and the curing agent (B) in a molten state to obtain a mixture containing a product obtained by partially reacting the epoxy resin (A) and the curing agent (B). Is. The kneading temperature is not particularly limited as long as it is a temperature at which the filler (C) treated with the silane coupling agent (D), the epoxy resin (A) and the curing agent (B) exist in a molten state, but usually room temperature ~ 15
0 ° C., preferably resin component, that is, epoxy resin (A)
And the softening point of the curing agent (B) is 120 ° C. Then, after that, it is important to add the solvent (E) and further knead to liquefy.

Conditions in which the filler (C) treated with the silane coupling agent (D), the epoxy resin (A) and the curing agent (B) are present in the molten state of the epoxy resin (A) and the curing agent (B). By kneading underneath, the surface of the filler (C) is a resin component composed of a mixture of epoxy resin (A), curing agent (B) and partial reaction products thereof,
As a result of being well wetted and the filler (C) being stably dispersed and included, by adding the solvent (E) and further kneading to liquefy, the liquefaction is facilitated and Sedimentation / precipitation of the filler (C) can be prevented. As a result, according to the method of the present invention, the resin component comprising the epoxy resin (A) and the curing agent (B) is dissolved or dispersed in the solvent (E) in advance, and then the other remaining components are added and kneaded. It is possible to increase the compounding amount of the filler (C) to 90% or more, which cannot be obtained by the above method, and the obtained liquid epoxy resin composition has workability, resistance to heat and humidity, and temperature cycle resistance reliability. A liquid epoxy resin composition excellent in any of the above can be obtained.

When the temperature at the time of melt-kneading is too low and the resin component consisting of the epoxy resin (A) and the curing agent (B) is not melted, no partial reaction occurs and the filler (C) Since the surface is not wetted by the resin component, only a liquid epoxy resin composition having poor workability, heat resistance to moisture and temperature cycle reliability can be obtained even if the solvent (E) is subsequently added and kneaded again. If the temperature at the time of melt-kneading is too high, the reaction between the epoxy resin (A) and the curing agent (B) proceeds too much, and in some cases, gelation occurs, and then liquefaction by adding the solvent (E). Is not possible or the viscosity is so high that only a liquid epoxy resin composition which cannot be coated with a dispenser can be obtained. When the resin component made of the epoxy resin (A) and the curing agent (B) is dissolved or dispersed in the solvent (E) in advance, and then the other remaining components are added and kneaded, the resin component Could not be prevented from precipitating and settling due to crystallization, and the filler (C) could not be dispersion-stabilized or had very poor dispersion stability, resulting in poor storage stability, wet heat resistance, and temperature cycle reliability. Only a liquid epoxy resin composition can be obtained.

A kneading method for kneading the filler (C) treated with the silane coupling agent (D), the epoxy resin (A) and the curing agent (B) in a molten state, and then adding the solvent (E). As the kneading method for kneading again, a known kneading method such as a kneader, planetary mixer, three rolls, single-screw or twin-screw extruder can be applied.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples.

Examples 1 to 4 and Comparative Examples 1 to 5 Liquid epoxide resin compositions for TAB were obtained using the raw materials shown in Table 1 and the composition ratios and the production methods shown in Table 2.

In the production method A, the components excluding the solvent were blended with a mixer. Roll surface temperature 90
The mixture was heated and melted and kneaded for 5 minutes using a mixing roll at ℃, and then cooled and pulverized to obtain a secondary raw material. Next, a solvent was added to this secondary raw material and mixed at room temperature, followed by kneading at room temperature using a triple roll to obtain a liquid epoxy resin composition for TAB.

In the production method B, after dissolving the resin components in the solvent in the composition ratios shown in Table 2, the remaining components were added and mixed at room temperature, and then the mixture was kneaded at room temperature using a three-roll mill, TA
A liquid epoxy resin composition for B was obtained.

[0038]

[Table 1]

[0039]

[Table 2]

The following tests were carried out using each of these compositions.

Moisture and heat resistance reliability test: Single-sided type film carrier ("Kapton" film thickness 50 μm, adhesive thickness 20)
Pseudo element (chip size 10 mm × 10 mm, line width, line spacing 8 μm, with silicon nitride film, pin number 248)
To 30 at 110 ℃.
Min, heated at 150 ° C. for 3 hours to be cured to obtain a test sample. The PCT test (12
The temperature was 1 ° C. and the relative humidity was 100%), and the continuity check was performed every 50 hours to check the time until a poor continuity occurred.

Temperature proof cycle reliability test: T using a test sample prepared in the same manner as for the wet heat reliability test.
CT test (-65 ° C x 30 minutes to room temperature x 5 minutes to 150 ° C x
(30 minutes / 1 cycle) was conducted, and the continuity check was conducted every 100 cycles, and the time until occurrence of poor continuity was examined.

Filler dispersibility check: Coating on a slide glass using a bar coater, and 110 ° C. for 30 minutes, 1
A check sample was obtained by heating at 50 ° C. for 3 hours for curing. The back surface of the check sample was observed with a microscope to examine the presence / absence of coagulation / precipitation of the filler depending on the dispersibility.

Solid content sedimentation test: A syringe for injection (inner diameter: 50 mm, effective length: 60 mm) was filled, left standing vertically at room temperature for 24 hours, and then extruded by applying air pressure. The composition was divided. Separated liquid composition was dried (150 ×
The solid content concentration was measured for 3 hours), and the presence or absence of solid content sedimentation during standing was examined.

The results are shown in Table 3.

[0046]

[Table 3]

[0047]

The liquid epoxy resin composition for semiconductor encapsulation of the present invention contains a specific epoxy resin, a specific curing agent, and a specific silane coupling agent, and is manufactured by a specific manufacturing method. Excellent in reliability, temperature cycle reliability and workability, especially prevention of sedimentation of solids.

Claims (4)

[Claims] 1. A liquid epoxy resin composition comprising an epoxy resin (A), a curing agent (B), a filler (C), a silane coupling agent (D) and a solvent (E), which comprises: The epoxy resin (A) has the following general formula (I): (In the formula, R ^{1 to} R ⁸ represent a hydrogen atom, a halogen atom or a C _{1 to} C ₄ lower alkyl group.) The biphenyl type epoxy resin (a) represented by The agent (B) has the following general formula (II): (However, in the formula, R ^{9 to} R ¹⁶ are hydrogen atoms, or C _{1 to} C ₄
Is a lower alkyl group. ) Contains a biphenol compound (b) as an essential component, and the solvent (E) accounts for 5 to 30% by weight of the entire liquid epoxy resin composition,
The residual component accounts for 70 to 95% by weight, and the proportion of the filler (C) is 75 to 95% by weight of the residual component,
A liquid epoxy resin composition for semiconductor encapsulation, wherein the ratio of the silane coupling agent (D) is 0.3 to 3.0% by weight of the remaining components. 2. The curing agent (B) is a biphenol compound (b) and the following general formula (III): (However, in the formula, n is an integer of 0 or 1 or more, R ^{17 to} R ²³ are a hydrogen atom, an aryl group or a C _{1 to} C ₄ lower alkyl group.) A polyphenol compound having a skeleton (b The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, further comprising ??? 3. The silane coupling agent (D) is γ-anilinopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane and γ-.
The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, which is one kind or a mixture of two or more kinds selected from (2-aminoethyl) aminopropylmethyldimethoxysilane. 4. A filler (C) treated with a silane coupling agent (D), an epoxy resin (A) and a curing agent (B).
And the epoxy resin (A) and the curing agent (B)
Is kneaded under the condition of being present in a molten state to obtain a mixture containing a product obtained by partially reacting the epoxy resin (A) with the curing agent (B), and then adding the solvent (E). The kneading is further performed to liquefy the mixture.
A method for producing the liquid epoxy resin composition for semiconductor encapsulation as described above.