KR20110095172A - Epoxy resin composition - Google Patents

Abstract

PURPOSE: An epoxy resin composition is provided to ensure high fluidity even in low viscosity, excellent pot life for a long time, and to enable the use as an underfill material in the flip chip mounting. CONSTITUTION: An epoxy resin composition comprises an epoxy compound(A), hardener(B), curing accelerator(C), inorganic filler(D) and silane coupling agent(E). The epoxy compound comprises: 20-80 weight% of a cyclic diepoxy compound represented by chemical formulas I or II; and 80-20 weight% of an epoxy compound excluding the cyclic diepoxy compound. The inorganic filler is inorganic particles surface-treated by the silane coupling agent.

Description

Epoxy resin composition {EPOXY RESIN COMPOSITION}

FIELD OF THE INVENTION The present invention relates to epoxy resin compositions, and more particularly to epoxy resin compositions which are preferred as underfill materials in semiconductor resin sealing materials, particularly in flip chip mounting.

In recent years, with the spread of small electronic devices such as digital cameras and mobile phones, there is a demand for downsizing of LSI devices. Therefore, a mounting method called flip chip mounting has become widespread in order to minimize the mounting area by face-downing semiconductor chips instead of wire bonding mounting and mounting them directly on a circuit board.

In flip chip mounting, the surface where the pad for connection of the chip is formed is connected to the lower side, and the pad for connection is electrically and mechanically connected by solder bumps to the opposing package or the surface electrode of the printed wiring board (PCB). At this time, since the space | gap by a solder bump generate | occur | produces between a mounting board | substrate and a chip | tip, the resin composition called an underfill material which seals between a mounting board | substrate and a chip | tip is injected into this space | gap. The underfill material usually contains an epoxy resin and a silica filler. The underfill material not only fills the voids, but also seals the electrical contacts using the solder bumps to protect them from the surroundings (prevents the ingress of moisture in the air), and at the same time the excessive force is applied to the solder bump joints, which are mechanical joints. It also has the purpose of preventing (improving the bonding strength).

In recent years, the high filling property of underfill is strongly requested | required by narrowing the gap and soldering pitch of the solder bump of flip chip mounting. In order to solve this problem, attention was paid to silica filler, which is one of the components of the underfill material, to blend fillers of different particle diameters (Japanese Patent Laid-Open No. 2007-204511), and to perform surface treatment (Japanese Patent Laid-Open). Japanese Patent Laid-Open No. 2002-146233, Japanese Patent Laid-Open No. 2003-238141, Japanese Patent Laid-Open No. 2006-193595, Japanese Patent Laid-Open No. 2007-254543, Japanese Patent Laid-Open No. 2008-297373), etc. Attempts have been made to increase the flowability of the materials.

In addition, there is a viscosity as one of the physical properties associated with the fluidity of the underfill material described above. Reducing the viscosity of the underfill material can be expected to increase the fluidity. However, when the silica particle content, which is a large factor for determining the viscosity, is decreased, the content of the resin component is relatively increased, and the linear expansion becomes large in the state after the underfill material curing, and the reliability is lowered.

As another method for achieving the low viscosity of an underfill material, the method of lowering the viscosity of the resin itself which comprises an underfill material is also considered. However, the glycidyl type epoxy compound generally mentioned as an available epoxy resin has a high viscosity. An alicyclic epoxy is mentioned as an epoxy compound which is low viscosity and can be obtained easily. For example, Japanese Patent No. 4322047 discloses an epoxy resin composition containing an alicyclic diepoxy compound having a specific structure.

Japanese Patent Laid-Open No. 2007-204511 Japanese Patent Laid-Open No. 2002-146233 Japanese Patent Laid-Open No. 2003-238141 Japanese Patent Laid-Open No. 2006-193595 Japanese Patent Laid-Open No. 2007-254543 Japanese Patent Laid-Open No. 2008-297373 Japanese Patent No. 4322047

However, the alicyclic epoxy is very reactive and thickens when mixed with silica. The epoxy resin composition containing an alicyclic epoxy and silica has a problem in the storage stability.

Therefore, the objective of this invention is providing the epoxy resin composition which is low viscosity, has high fluidity, and is excellent in storage stability. In particular, it is an object of the present invention to provide an epoxy resin composition which is suitable as an underfill material in flip chip mounting having low viscosity and high flowability and excellent storage stability. Moreover, the objective of this invention is providing the semiconductor package in which the said epoxy resin composition was used as an underfill material.

The present invention includes the following inventions.

(1) It is an epoxy resin composition containing an epoxy compound (A), a hardening | curing agent (B), a hardening accelerator (C), an inorganic filler (D), and a silane coupling agent (E),

The epoxy compound (A) is 20 to 80% by weight of an alicyclic diepoxy compound (a1) represented by the following formula (I) or (II), and an epoxy compound (a2) other than the alicyclic diepoxy compound (a1) 80 to Including 20% by weight,

The said inorganic filler (D) is an epoxy resin composition which is inorganic fine particles surface-treated with the silane coupling agent.

<Formula I>

(Wherein R ₁ to R ₁₈ may be the same or different, respectively, and represent a hydrocarbon group which may include a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent)

<Formula II>

(Wherein R ₂₁ to R ₃₈ may each be the same or different and represent a hydrocarbon group which may include a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent)

(2) The said (1), The compounding ratio of the said hardening | curing agent (B) is 0.6-1.05 equivalent with respect to 1 equivalent of (A) component,

The compounding ratio of the said hardening accelerator (C) is 0.1-10 weight part with respect to 100 weight part of (A) component,

The compounding ratio of the said inorganic filler (D) is 30-80 weight% based on the total amount of (A), (B), (C), and (D) component,

The epoxy resin composition of the said silane coupling agent (E) is 0.1-5 weight part with respect to 100 weight part of (A) component.

(3) In the above (1) or (2), the alicyclic diepoxy compound (a1) is a compound wherein R ₁ to R ₁₈ are hydrogen atoms in the formula (I), and / or R ₂₁ to R in the formula (II) _The epoxy resin composition whose compound is ₃₁ is a hydrogen atom.

(4) The epoxy resin composition according to any one of (1) to (3), wherein the inorganic fine particles are silica fine particles, alumina fine particles, or titanium oxide fine particles.

(5) The epoxy resin composition according to any one of (1) to (4), wherein the silane coupling agent for surface treating the inorganic fine particles is an epoxy group-containing silane coupling agent or an amino group-containing silane coupling agent.

(6) The epoxy resin composition as described in any one of said (1)-(5) whose average particle diameter of the said inorganic fine particle is 0.1-50 micrometers.

(7) The area according to any one of (1) to (6), wherein at least a part of the silane coupling agent is chemically bonded to the inorganic fine particle, and the chemically bonded silane coupling agent covers the surface of the fine particle. The proportion is 10% or more based on the total surface area of the fine particles.

(8) The epoxy resin composition for underfill materials in any one of said (1)-(7).

(9) A semiconductor package comprising a mounting substrate and semiconductor chips disposed on the mounting substrate via bumps,

The gap between the said mounting substrate and the said semiconductor chip is sealed by the hardened | cured material of the epoxy resin composition in any one of said (1)-(8).

Since the epoxy resin composition of this invention contains the said specific alicyclic diepoxy compound as a resin component, and contains the inorganic fine particle surface-treated with the silane coupling agent as an inorganic filler, it is near room temperature (for example, 5-30 degreeC). ) Has low viscosity and high fluidity, and excellent storage stability (pot life: pot life) for a long time. In addition, the epoxy resin composition of the present invention is also excellent in stability over time of the cured product.

The epoxy resin composition of the present invention has a low viscosity and high fluidity at room temperature and is excellent in storage stability (availability time) for a long time, so that the underfill material is filled in the gap between the mounting substrate and the semiconductor chip in flip chip mounting. Very preferred.

That is, the epoxy resin composition of the present invention has a low viscosity and high fluidity in the vicinity of the room temperature at which the underfill injection operation is performed, so that even when the mounting substrate and the semiconductor chip are narrowed or narrowed, the entire injection surface is very short. Underfill injection can be performed homogeneously.

Moreover, the epoxy resin composition of this invention is excellent in pot life, and low viscosity and high fluidity in room temperature vicinity are maintained over a long time. Therefore, there is an advantage that the workability of underfill injection is greatly improved. When the viscosity of the epoxy resin composition as an underfill material is high, the method of generally raising the temperature of the said resin composition and reducing the viscosity at the time of injection is used. However, when the temperature of the said resin composition is raised, the hardening reaction of an epoxy resin composition will also be accelerated | stimulated and a viscosity will rise further as a result. In some cases, it may be cured before the resin composition flows into the entire injection surface. According to the epoxy resin composition of the present invention, since the pot life is excellent and low viscosity and high fluidity at room temperature are maintained for a long time, it is not necessary to adjust the viscosity by heating during the underfill injection operation, and it is stable and homogeneous. Underfill injection can be performed.

Moreover, since the semiconductor package (semiconductor device) sealed by the epoxy resin composition of this invention is inject | poured a homogeneous underfill material, it is highly reliable.

The epoxy resin composition of this invention contains an epoxy compound (A), a hardening | curing agent (B), a hardening accelerator (C), an inorganic filler (D), and a silane coupling agent (E).

The epoxy compound (A) includes an alicyclic diepoxy compound (a1) represented by the following general formula (I) or the following general formula (II), and an epoxy compound (a2) other than the alicyclic diepoxy compound (a1).

<Formula I>

(Wherein R ₁ to R ₁₈ may be the same or different, respectively, and represent a hydrocarbon group which may include a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent)

<Formula II>

(Wherein R ₂₁ to R ₃₈ may each be the same or different and represent a hydrocarbon group which may include a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent)

As said alicyclic diepoxy compound (a1), any of the alicyclic diepoxy compound represented by the said general formula (I) and the alicyclic diepoxy compound represented by the said general formula (II) may be used, and both may be used together. The alicyclic diepoxy compound (a1) has a low viscosity near room temperature (for example, 5 to 30 ° C) and can impart high fluidity to the epoxy resin composition.

Examples of the halogen atom represented by R ₁ to R ₁₈ in the formula (I) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of the hydrocarbon group represented by R ₁ to R ₁₈ include lower alkyl groups having 1 to 10 carbon atoms, and specific examples thereof include linear alkyl groups such as methyl group, ethyl group and hexyl group, isopropyl group, neopentyl group and 2-ethylhexyl group. A branched alkyl group etc. are mentioned. The hydrocarbon group may contain an oxygen atom or a halogen atom. Examples of the halogen atom include the same ones as described above. The case where an oxygen atom is included means the case where it has an OH group and a carboxyl group as a substituent.

As an alkoxy group which R <_1> -R <_18> represents, a C1-C10 lower alkoxy group is mentioned, A methoxy group, an ethoxy group, a propanoxy group, butoxy group etc. are mentioned as a specific example. The alkoxy group may have a substituent and a lower alkoxy group, a halogen atom, etc. are mentioned as a substituent, for example.

In the present invention, a compound (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate) wherein R ₁ to R ₁₈ in the formula (I) is a hydrogen atom is preferable. 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate is available, for example, as a ceoxide CEL-2021P manufactured by Daicel Chemical Industries, Ltd., and ERL4221 manufactured by Union Carbide.

Examples of the halogen atom represented by R ₂₁ to R ₃₈ in the formula (II) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the hydrocarbon group represented by R ₂₁ to R ₃₈ include lower alkyl groups having 1 to 10 carbon atoms, and specific examples thereof include linear alkyl groups such as methyl group, ethyl group and hexyl group, isopropyl group, neopentyl group and 2-ethylhexyl group. A branched alkyl group etc. are mentioned. The hydrocarbon group may contain an oxygen atom or a halogen atom. Examples of the halogen atom include the same ones as described above. The case where an oxygen atom is included means the case where it has an OH group and a carboxyl group as a substituent.

As an alkoxy group which R <_21> -R <_38> represents, a C1-C10 lower alkoxy group is mentioned, A methoxy group, an ethoxy group, a propanoxy group, butoxy group etc. are mentioned as a specific example. The alkoxy group may have a substituent and a lower alkoxy group, a halogen atom, etc. are mentioned as a substituent, for example.

In the present invention, a compound (bicyclohexyl-3,3'-diepoxide) in which R ₂₁ to R ₃₈ in the formula (II) is a hydrogen atom is preferable.

The compounds of formula (II) are, for example, unsaturated compounds having a bicyclohexyl-3,3'-diene skeleton and oxidizing agents, in particular organic percarboxylic acids (performic acid, peracetic acid, perbenzoic acid, perisobutyric acid, trifluoro Low peracetic acid and the like). Among the organic percarboxylic acids, peracetic acid is a preferred epoxidizing agent in view of reactivity and stability. For the preparation of the compound of Formula II, Japanese Patent No. 4322047 can be referred to.

As the epoxy compound (a2) other than the alicyclic diepoxy compound (a1), any one can be used as long as it has two or more epoxy groups in one molecule, but in particular bisphenol A and F type epoxy resins, phenol novolac type epoxy resins, A naphthalene type epoxy resin, a biphenyl type epoxy resin, a cyclopentadiene type epoxy resin, etc. are illustrated. Among these, bisphenol A and F-type epoxy resins are preferable for low viscosity.

In this invention, 20-80 weight% of said alicyclic diepoxy compounds (a1) and 80-20 weight% of epoxy compounds (a2) other than the said alicyclic diepoxy compound (a1) are mix | blended as said epoxy compound (A). . The total amount of the compound (a1) and the compound (a2) is 100% by weight. If the compounding quantity of a compound (a1) is less than 20 weight%, the fluidity | liquidity provision effect with respect to an epoxy resin composition will become weak. On the other hand, when the compounding quantity of a compound (a1) exceeds 80 weight%, the hardened | cured material of an epoxy resin composition will become weak, and impact resistance will fall. Preferable compounding quantities are 25 to 75 weight% of compound (a1), 75 to 25 weight% of compound (a2), and more preferable compounding amounts are 30 to 70 weight% of compound (a1) and 70 to 30 weight% of compound (a2).

By setting the epoxy compound (A) as described above, an epoxy resin composition having a low viscosity and high fluidity around room temperature is obtained. In addition, an epoxy compound (A) is called the epoxy resin in many cases.

As a hardening | curing agent (B) which hardens the said epoxy compound (A), a phenol resin, an acid anhydride, and an amine compound can be used. Among these, an acid anhydride is preferable from a viewpoint of low viscosity of a composition.

Examples of the acid anhydride as the curing agent (B) include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, alkylated methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhymic anhydride, dodecenyl succinic anhydride and the like.

As for the compounding ratio of the said acid anhydride (B), it is preferable that the said acid anhydride equivalent becomes 0.60-1.05 per 1 equivalent of epoxy group in the said epoxy compound (A), More preferably, it is 0.80-1.00 equivalent. If the blending amount of the acid anhydride (B) is less than 0.60 equivalent, the curability may be insufficient. On the other hand, if it exceeds 1.05 equivalent, a large amount of unreacted acid anhydride may be present, leading to a decrease in the glass transition temperature of the obtained cured product. have. In addition, about the equivalence relationship of an epoxy compound (A) and an acid anhydride (B), let 1 equivalent be the case where there is one acid anhydride group in an acid anhydride with respect to one epoxy group in a compound (A). By using the said hardening | curing agent (B) in the compounding quantity of the said range, especially the balance of curability and fluidity becomes excellent. These hardeners may be used independently and may be used together 2 or more types.

Phenolic resin as a hardening | curing agent (B) is a compound containing two or more phenolic hydroxyl groups, Novolak-type phenol resins, such as a phenol novolak resin and a cresol novolak resin, a triphenol methane type phenol resin, a triphenol propane type phenol resin Modified phenol resins such as terpene-modified phenol resins and dicyclopentadiene-modified phenol resins, phenol aralkyl resins having a phenylene and / or biphenylene skeleton, naphthol aralkyl resins having a phenylene and / or biphenylene skeleton Aralkyl type phenol resins, bisphenol compounds, etc. are mentioned.

The amine compound as the curing agent (B) is a compound containing two or more primary amines or secondary amines, and diethylenetriamine, triethylenetetramine, tetraethylenepentamine, m-xylylenediamine, and trimethylhexamethylene Aliphatic polyamines such as diamine and 2-methylpentamethylenediamine, isophoronediamine, 1,3-bisaminomethylcyclohexane, bis (4-aminocyclohexyl) methane, norbornenediamine, 1,2-diaminocyclohexane Aromatic polyamines, such as alicyclic polyamine and m-phenylenediamine, etc. are mentioned.

The blending ratio in the case of using a phenol resin or an amine compound can be such that the OH group equivalent (active hydrogen equivalent) of the phenol resin and the amine group equivalent (active hydrogen equivalent) of the amine compound are 0.60 to 1.05 per equivalent of epoxy group. have.

A hardening accelerator (C) is mix | blended with the composition of this invention.

As said hardening accelerator (C), although what is used as hardening accelerator of epoxy resins, such as an imidazole series, a tertiary amine type, and a phosphorus compound type, is mentioned, It does not specifically limit. For example, imidazole type, such as 2-methylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole; Tertiary amines such as benzyldimethylamine, trisdimethylaminomethylphenol and triethylenediamine; Quaternary ammonium salts such as tetrabutylammonium bromide; Organic acid salts of diazabicyclo undecene (DBU) or DBU; Phosphorus compound systems, such as a triphenylphosphine and a phosphate ester, etc. are mentioned. It is also possible to use the latent ones such as microcapsule coating and complex salt formation. These may be used independently and may use 2 or more types together according to hardening conditions.

It is preferable to set it as 0.1-10 weight part with respect to 100 weight part of said epoxy compounds (A), and, as for the compounding quantity of the said hardening accelerator (C), it is more preferable to set it as 0.5-5 weight part. If the compounding quantity of a hardening accelerator (C) is less than 0.1 weight part, hardening acceleration effect will be hard to be acquired. On the other hand, if a compounding quantity exceeds 10 weight part, hardening reaction will become too fast. By using the said hardening accelerator (C) in the compounding quantity of the said range, hardening advances rapidly and the improvement of the throughput of a sealing process can be expected.

Inorganic filler (D) is mix | blended with the composition of this invention. The said inorganic filler (D) is inorganic fine particles surface-treated with the silane coupling agent. The inorganic fine particles are selected from silica fine particles, alumina fine particles, titanium oxide fine particles and the like. Among these, silica is preferable in that the coefficient of linear expansion is low. By containing silica in a composition, the linear expansion coefficient after hardening of an epoxy resin composition can be made small. Accordingly, when the epoxy resin composition is used as the underfill material of the semiconductor package, the linear expansion coefficient of the underfill material after curing can be made close to the linear expansion coefficient of the semiconductor chip or the substrate, and as a result, stress concentration at the solder bump junction can be avoided. The connection reliability at the time of the heat cycle process can be improved.

The said inorganic fine particles as said inorganic filler (D) are surface-treated with the silane coupling agent. As for the silane coupling agent here, an epoxy group containing silane coupling agent or an amino group containing silane coupling agent is preferable. Examples of the epoxy group-containing silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3 -Glycidoxy propyl triethoxysilane, etc. are mentioned. As an amino-group containing silane coupling agent, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2-, for example (Aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butyly Den) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, hydrochloride of N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane, etc. are mentioned.

It is preferable that it is spherical as a shape of the said inorganic fine particle, Especially it is preferable from a viewpoint of fluidity that it is fused silica and is close to a true spherical particle. Moreover, it is preferable that it is fused alumina and is close to a true sphere among alumina. 0.1-50 micrometers is preferable and, as for the average particle diameter of the said inorganic fine particle, 0.5-5 micrometers is more preferable. By using particles such as silica having an average particle diameter in such a range, penetration into a narrow gap can be ensured. Here, the average particle diameter is shown the median diameter d _50.

As a surface treatment method of the said inorganic fine particle, Drying method which sprays a silane coupling agent, blows in a vapor state, stirring an inorganic fine particle, and heat-processes as needed; The wet method of disperse | distributing an inorganic fine particle in a solvent, diluting a silane coupling agent in water or an organic solvent, stirring and stirring both in slurry form, and removing a solvent after that is mentioned. The treatment in which the silane coupling agent is chemically bonded to the silica surface is preferred.

The theoretical addition amount (the amount of the silane coupling agent for covering the total surface area of silica) of the silane coupling agent used in the surface treatment of the said inorganic fine particle is represented by following formula (1). Hereinafter, the case of silica is demonstrated. The same applies to other inorganic particles.

&Quot; (1) &quot;

Theoretical addition amount (g) of a silane coupling agent = [silica weight (g) x silica specific surface area (m <2> / g)] / minimum covering area of a silane coupling agent (m <2> / g)

The minimum covering area of each silane coupling agent is calculated as follows.

When the functional group is a trialkoxysilane, Si (O) ₃ obtained by hydrolysis is 1 Si atom containing a spherical radius of 2.10 angstroms, 3 O atoms containing a spherical radius of 1.52 angstroms, and a bonding distance of Si-O 1.51. Assuming an angstrom, tetrahedral angle of 109.5 ° and assuming that all three O atoms in the model react with silanol groups on the silica surface, the minimum circular area that can cover the three O atoms is calculated. As a result, the covering area per molecule is 13.3 × 10 ⁻²⁰ m 2 / molecule. For example, for 3-glycidoxypropyltrimethoxysilane (molecular weight: 236.3) the minimum coating area is 330 m 2 / g. When the calculated minimum covering area is applied to the above equation (1), the theoretical addition amount of the silane coupling agent is obtained.

The minimum coating area of the silane coupling agent is represented by the following equation.

<Equation 2>

Minimum Coverage Area of the Silane Coupling Agent (m 2 /g)=[6.02×10 ²³ × 13.3 × 10 ^-20 ] / Molecular Weight of the Silane Coupling Agent

In the present invention, the ratio of the amount of the silane coupling agent chemically bonded to the silica surface to the theoretical addition amount of the silane coupling agent, that is, the amount of silica coated by the silane coupling agent chemically bonded to the silica surface to the total surface area of the silica. It is preferable that the area ratio of surface area (this is called "chemical bonding surface treatment rate" in this specification) is 10% or more.

This chemical bond surface treatment rate can be analyzed using differential thermal analysis (DTA).

Silica particles surface-treated with a silane coupling agent are added to thermogravimetric / differential thermal analysis (TG / DTA) and the temperature is raised from around room temperature to 800 ° C.

A weight reduction of the silica particles is observed near the boiling point of the silane coupling agent used. This weight loss is attributable to the fact that the silane coupling agent, which was physically or chemically attached to the silica particle surface rather than a chemical bond, was scattered at a temperature near its boiling point.

When the temperature is raised to 800 ° C over the temperature near the boiling point, a further decrease in the weight of the silica particles is observed. This weight reduction is due to the thermal decomposition of the silane coupling agent that was bonded to the surface of the silica particles via a Si—O—Si chemical bond due to high temperature, and the organic portion of the silane coupling agent disappeared.

Thus, by measuring the weight loss of the silica particles in the temperature range of (boiling point of the silane coupling agent + 30 ° C) to 800 ° C depending on the boiling point of the silane coupling agent used, the chemical bond by the following equation (3) Surface treatment rate (%) is calculated.

&Quot; (3) &quot;

Chemical bonding surface treatment rate (%) = [weight loss per gram of silica (g) / gram of silane coupling agent per gram of silica (g) per gram of silica at boiling point + 30 ° C. to 800 ° C.) of silane coupling agent] × 100

The boiling point of the silane coupling agent exemplified above is 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (molecular weight: 246.4, boiling point: 310 ° C), 3-glycidoxypropyltrimethoxy Since it is a silane (molecular weight: 236.3, boiling point: 290 ° C), in this case, the weight loss of the silica at 350 ° C to 800 ° C can be measured substantially.

In the present invention, it is preferable to use inorganic fine particles such as silica having a chemical bond surface treatment rate of 10% or more, more preferably 30% or more of inorganic fine particles, more preferably 60% or more of inorganic fine particles, Most preferably, 80% or more of inorganic fine particles are used. By using inorganic fine particles such as silica having such chemical bonding surface treatment rate, the affinity with the resin component is improved, and acidic (for example, silanol groups) on the surface of the inorganic fine particles such as silica are reduced, thereby preserving stability of the epoxy resin composition. Can be improved, and the viscosity rise is suppressed.

It is preferable to make the compounding ratio of the said inorganic filler (D) into 30 to 80 weight% based on the total amount of the said (A), (B), (C) and (D) component, and to make it as 35 to 80 weight% It is more preferable, and it is still more preferable to set it as 45 to 75 weight%. If the compounding ratio of an inorganic filler (D) is less than 30 weight%, a resin component will increase relatively and the linear expansion coefficient of the hardened | cured material obtained will become large easily. On the other hand, when the compounding ratio of an inorganic filler (D) exceeds 80 weight%, the viscosity of a composition rises and there exists a tendency for fluidity to fall.

A silane coupling agent (E) is mix | blended with the composition of this invention.

As the silane coupling agent (E), known ones can be used, for example, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxy Epoxy group-containing silane coupling agents such as propylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane; For example, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3- Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- It is preferable to use amino group-containing silane coupling agents such as hydrochloride of phenyl-3-aminopropyltrimethoxysilane and N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane. Although the same kind as the thing used as the surface treating agent of the said inorganic filler (D) can also be used, A different thing can also be used.

It is preferable to set it as 0.1-5 weight part with respect to 100 weight part of said epoxy compounds (A), and, as for the compounding ratio of the said silane coupling agent (E), it is more preferable to set it as 0.5-3 weight part. By setting it as such a range, adhesiveness with respect to the surface of a silicon chip or a board | substrate becomes high and reliability can be improved.

In the epoxy resin composition of the present invention, in addition to the components (A) to (E) described above, pigments, dyes, modifiers, thixotropic agents, anti-colorants, and oxidation in a range that does not violate the object of the present invention. Additives, such as an inhibitor, a mold release agent, surfactant, and a diluent, can be mix | blended.

The epoxy resin composition of this invention can mix and manufacture each component (A)-(E) in predetermined ratio. Mixing can be performed at normal temperature (for example, 5-30 degreeC) using well-known things, such as a rotating revolving mixer, a dry blender, a ribbon blender, and a Henschel mixer.

The prepared epoxy resin composition can be used for various applications including adhesives. When using as an underfill material of a semiconductor package, an epoxy resin composition is inject | poured into the clearance gap between a mounting board | substrate and the semiconductor chip arrange | positioned through bump on the said mounting board | substrate. Injection can be performed at room temperature (5-30 degreeC). Thereafter, the curing time 30 to 600 minutes, preferably 45 to 540 minutes, more preferably at a desired curing condition, for example, temperature 100 to 200 ℃, preferably 100 to 190 ℃, more preferably 100 to 180 ℃ Preferably for 60 to 480 minutes. The curing temperature may be raised or lowered in stages.

Since the epoxy resin composition of the present invention has a low viscosity and high fluidity around room temperature at which the underfill injection operation is performed, it is not necessary to warm the epoxy resin composition and adjust the viscosity prior to injection, thereby narrowing the mounting substrate and the semiconductor chip. Even when the pitch is narrowed, underfill injection can be performed homogeneously (without leaving gaps or bubbles with each member) throughout the injection surface in a very short time.

In addition, the epoxy resin composition of the present invention is suitable not only for use as an underfill material but also for use for bonding objects (members) to be bonded to each other disposed with a narrow gap. For example, it can use suitably also for adhesion | attachment of the lens holder and a lens in the imaging lens unit used for a small imaging device, an optical sensor, a portable module camera, etc.

Although the material used for the lens holder in an imaging lens unit is not specifically limited, For example, liquid crystal polymers: Thermoplastics, such as LCP (liquid crystal polymer (black)), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), etc. Thermosetting resins, such as resin and a phenol resin, are mentioned. As the material of the optical lens, silicon; Glass; The resin composition obtained by superposing | polymerizing and crosslinking the organic monomer which has reactivity, such as an epoxy group, a vinyl group, and a (meth) acryloyl group, is mentioned.

In the manufacture of the imaging lens unit, there is a narrow gap between the lens holder and the lens. The epoxy resin composition of this invention is inject | poured into this clearance gap. Since the epoxy resin composition of this invention has a low viscosity and a high fluidity | liquidity, it penetrates uniformly in the said gap in a short time. Thereafter, when curing is performed under the above-described curing conditions, the lens holder and the lens are firmly adhered to each other.

[Example]

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further more concretely, this invention is not limited by these Examples. First, it shows about each measuring method.

Example 1

3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate as an alicyclic diepoxy compound (manufactured by Daicel Chemical Industries, Inc., Celoxide 2021P, R ₁ to R ₁₈ = H in Formula I) 10.0 2 parts by weight, 20.0 parts by weight of bisphenol F-type epoxy resin (manufactured by Nippon Kayaku Co., RE-303L) and methylhexahydro phthalic anhydride (manufactured by Shin-Nippon Chemical Co., Ltd., MH700, equivalent to about 168) as a curing agent. Γ-glycidoxypropyltrimethoxysilane (manufactured by Tokyo Kasei Co., Ltd.) 0.4 parts by weight of an imidazole epoxy resin adduct curing agent (manufactured by Asahi Kasei Imaterials, Novacure HX-3088), and a silane coupling agent. Silica SC4500-SQ (a spherical fused silica surface-treated with γ-aminopropyltriethoxysilane manufactured by Admatecs, Inc., with a mean particle size of 1.0 μm, specific surface area of 4.0 m 2 / g) as a weight part and a filler 67.4 weight To call Stirred at room temperature for a ball type mixer, and mixed to obtain an adhesive composition.

[Example 2]

As a filler, instead of silica SC4500-SQ, a spherical spherical surface treated with silica SC4500-SEJ (manufactured by Admatech Co., Ltd., average particle diameter 1.0 μm, specific surface area 4.0 m 2 / g, γ-glycidoxypropyltrimethoxysilane) Fused Silica) An adhesive composition was obtained in the same manner as in Example 1, except that 67.4 parts by weight was used.

Example 3

3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate as an alicyclic diepoxy compound (manufactured by Daicel Chemical Industries, Inc., Celoxide 2021P, R ₁ to R ₁₈ = H in Formula I) 10.0 An adhesive composition was obtained in the same manner as in Example 2 except that 10.0 parts by weight of bicyclohexyl-3,3'-diepoxide (R ₂₁ to R ₃₈ = H in Formula II) was used instead of parts by weight.

Comparative Example 1

67.4 parts by weight of silica SC-C3 (manufactured by Adematech Co., Ltd., 1.0 μm, specific surface area 4.0 m 2 / g, spherical fused silica without surface treatment) was used instead of silica SC4500-SQ as a filler. In the same manner as in Example 1, an adhesive composition was obtained.

Comparative Example 2

Except for using 20.0 parts by weight of bisphenol F-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-303L) without using 10.0 parts by weight of an alicyclic diepoxy compound ceoxide 2021P (manufactured by Daicel Chemical Industries, Ltd.) In the same manner, an adhesive composition was obtained.

The compounding composition of the composition of each Example and a comparative example is shown in Table 1. In Table 1, each compounding quantity shows a weight part.

The used raw material is as follows.

<Alicyclic diepoxy compound>

3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (made by Daicel Chemical Industries, Celoxide 2021P, R ₁ to R ₁₈ = H in Formula I)

Bicyclohexyl-3,3'-diepoxide (R ₂₁ to R ₃₈ = H in Formula II)

<Epoxy resin>

Bisphenol F-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE-303L)

<Hardener>

Methylhexahydro phthalic anhydride (Shin-Nippon Chemical Co., Ltd., MH700, acid anhydride equivalent: about 168)

<Hardening accelerator>

Epoxy resin adduct hardener of imidazole (manufactured by Asahi Kasei Imatrials, Novacure HX-3088)

<Filler>

SC4500-SQ (a spherical fused silica surface treated with Admatech Co., Ltd., average particle diameter of 1.0 μm, specific surface area of 4.0 m 2 / g, gamma -aminopropyltriethoxysilane)

The weight loss rate at 350 ° C to 800 ° C by TG / DTA was 0.40%.

Silica SC4500-SEJ (manufactured by Kabushiki Kaisha Admatecs, average particle diameter 1.0 μm, specific surface area 4.0 m 2 / g, spherical fused silica surface-treated with γ-glycidoxypropyltrimethoxysilane)

The weight loss rate at 350 ° C to 800 ° C by TG / DTA was 1.01%.

Silica SC-C3 (manufactured by Kawasaki Co., Ltd., Inc., with an average particle diameter of 1.0 µm, specific surface area of 4.0 m 2 / g, and surface-treated spherical fused silica)

The weight loss rate at 350 ° C to 800 ° C by TG / DTA was 0.17%.

<Silane coupling agent>

Γ-glycidoxypropyltrimethoxysilane (manufactured by Tokyo Kasei Co., Ltd.)

[Assessment Methods]

(Chemical bond surface treatment rate of silica)

For each silica SC4500-SQ, SC4500-SEJ, SC-C3, the sample was heated from room temperature to 800 ° C using TG / DTA (EXSTAR6300, manufactured by Seiko Instruments Co., Ltd.) (heating rate: 20 ° C / min), 350 The weight loss at 캜 to 800 캜 was measured to calculate the weight loss rate as described above.

In addition, about SC4500-SQ and SC4500-SEJ surface-treated with the silane coupling agent, the chemical bond surface treatment rate was computed from the following formula (4).

<Equation 4>

Chemical bonding surface treatment rate (%) = [theoretical addition amount of silane coupling agent per gram of silica (g) / g of silica at 350 ° C. to 800 ° C.] × 100

About each composition obtained by the Example and the comparative example, the viscosity and permeability were evaluated as follows. Evaluation was performed about the composition (initial stage) immediately after manufacture, and the composition (after 24 hours) which was left to stand for 24 hours after manufacture in the environment of the temperature of 25 degreeC, and 50% of humidity. The results are shown in Table 2.

(Viscosity)

It was calculated | required from the average of the viscosity of the shear rate 15-25 s- ¹ area | region at 25 degreeC using the rheometer (PHYSICA, UDS200 / Paar, the product made by Fijika Co., Ltd.) (unit Pa.S).

(permeability)

The time until the composition (room temperature) is injected into one side and the gap is filled in the state while maintaining the Matsunami immersion plate (18 × 18 mm, clearance 70 μm, manufactured by Matsunami Glass Co., Ltd.) at 50 ° C. ( Seconds) were measured.

(Chargeability)

In the said permeability test, the glass plate after inject | pouring a composition was visually observed and (circle) that there was no bubble was made into (circle) and a thing with bubble was made into x.

From Table 2, the epoxy resin compositions of Examples 1 and 2 were low in viscosity, very excellent in permeability and filling properties, showed good results even after 24 hours, and were also excellent in storage stability. The epoxy resin composition of Example 3 had a very low initial viscosity of 0.8 Pa · s. These epoxy resin compositions can be used suitably as an underfill material of a semiconductor package.

Example 4

The adhesive composition of Example 1 was subjected to a semiconductor device model (3 cm × 4 cm) with a device size of 1 mm × 1 mm, bump pitch: 200 μm, gap (gap): 43 to 45 μm at 60 ° C. Injected into the gap, penetrated, and then cured by heating at 100 ° C. for 1 hour and then at 150 ° C. for 2 hours. As observed after the curing, the penetration state of the adhesive composition into the device test article was good, and no defects such as non-penetrating portions and residual bubbles of the adhesive composition were observed in the device test article. Moreover, when the apparatus test product after hardening was used for the heat cycle test for 30 minutes at -50 degreeC, and 30 degreeC at 125 degreeC, the adhesive surface did not peel even after 200 cycles, and the curvature also stopped to the extent which does not interfere practically.

Moreover, the adhesive composition itself of Example 1 was hardened on the same conditions as the above, and it was set as the hardened | cured material sample. The glass transition temperature (Tg) of the obtained hardened | cured material sample was 171 degreeC, and it was confirmed that the hardened | cured material sample has favorable heat resistance.

Example 5

Except having used the adhesive composition of Example 2 instead of the adhesive composition of Example 1, the injection, hardening, and a heat cycle test were done similarly to Example 4 using the semiconductor device model (3 cm x 4 cm). As observed after the curing, the penetration state of the adhesive composition into the device test article was good, and no defects such as non-penetrating portions of the adhesive composition and residual bubbles were observed in the device test article. Moreover, even after 200 cycles, the adhesive surface did not peel, and the curvature also stopped to the extent that it does not interfere with practical use.

In addition, the adhesive composition itself of Example 2 was hardened on the same conditions as the above, and it was set as the hardened | cured material sample. The glass transition temperature (Tg) of the obtained hardened | cured material sample was 165 degreeC, and it was confirmed that the hardened | cured material sample has favorable heat resistance.

Example 6

As a model of an imaging lens unit used for a small imaging device, an optical sensor, a portable module camera, etc., adhesion was performed using black LCP (liquid crystal polymer) as a representative lens holder member and a silicon convex lens as a lens.

The lens was attached onto the lens holding portion (cylindrical rib projecting from the holder inner surface in the cylinder) in a cylindrical lens holder made of black LCP to position the center of the lens with the center of the holder. At this time, a gap of about 100 μm was present between the inner circumferential surface of the holder and the peripheral end surface of the lens. Then, the adhesive composition of Example 1 was injected from the gap, and the adhesive composition was filled in the gap between the inner surface of the holder and the gap between the rib and the outer lens and immediately heated at 100 ° C. for 1 hour, and then at 150 ° C. for 2 hours. It hardened and the lens holder was obtained. After visually observing the holder with the lens after curing and evaluating the permeability and filling properties of the adhesive composition, the adhesive composition spreads evenly on the inner surface of the holder and the gap between the ribs and the outer peripheral portion of the lens. No residue of was observed. Thus, good permeability and filling properties were shown.

In addition, when the holder with a lens obtained here was used for a heat cycle test for 30 minutes at -50 degreeC and 30 minutes at 125 degreeC, the lens was firmly adhere | attached to a holder even after 100 cycles passed, and showed favorable adhesiveness.

Claims (9)

It is an epoxy resin composition containing an epoxy compound (A), a hardening | curing agent (B), a hardening accelerator (C), an inorganic filler (D), and a silane coupling agent (E),
The epoxy compound (A) is 20 to 80% by weight of an alicyclic diepoxy compound (a1) represented by the following formula (I) or (II), and an epoxy compound (a2) other than the alicyclic diepoxy compound (a1) 80 to Including 20% by weight,
The said inorganic filler (D) is an epoxy resin composition which is inorganic fine particles surface-treated with the silane coupling agent.
<Formula I>

(Wherein R ₁ to R ₁₈ may be the same or different, respectively, and represent a hydrocarbon group which may include a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent)
<Formula II>

(Wherein R ₂₁ to R ₃₈ may each be the same or different and represent a hydrocarbon group which may include a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent) The compounding ratio of the said hardening | curing agent (B) is 0.6-1.05 equivalent with respect to 1 equivalent of (A) component,
The compounding ratio of the said hardening accelerator (C) is 0.1-10 weight part with respect to 100 weight part of (A) component,
The compounding ratio of the said inorganic filler (D) is 30-80 weight% based on the total amount of (A), (B), (C), and (D) component,
The epoxy resin composition of the said silane coupling agent (E) is 0.1-5 weight part with respect to 100 weight part of (A) component. The epoxy according to claim 1, wherein the alicyclic diepoxy compound (a1) is a compound in which R ₁ to R ₁₈ are hydrogen atoms in Formula I, and / or a compound in which R ₂₁ to R ₃₁ are hydrogen atoms in Formula II. Resin composition. The epoxy resin composition of claim 1, wherein the inorganic fine particles are silica fine particles, alumina fine particles, or titanium oxide fine particles. The epoxy resin composition according to claim 1, wherein the silane coupling agent for surface treating the inorganic fine particles is an epoxy group-containing silane coupling agent or an amino group-containing silane coupling agent. The epoxy resin composition of claim 1, wherein the average particle diameter of the inorganic fine particles is 0.1 to 50 µm. The method of claim 1, wherein at least a portion of the silane coupling agent is chemically bonded to the inorganic fine particles, and the area ratio of the chemically bonded silane coupling agent covering the surface of the fine particles is 10 based on the total surface area of the fine particles. Epoxy resin composition which is more than%. The epoxy resin composition of Claim 1 for underfill materials. A semiconductor package comprising a mounting substrate and a semiconductor chip disposed through the bump on the mounting substrate,
The semiconductor package in which the clearance gap between the said mounting substrate and the said semiconductor chip is sealed by the hardened | cured material of the epoxy resin composition of Claim 1.