Liquid underfill resin composition, electronic component device, and method for manufacturing electronic component device

Abstract

To provide a liquid resin composition for underfill having a low thermal expansion coefficient and low elastic moduli at high temperatures, an electronic component device using the composition, and a method for manufacturing an electronic component device.SOLUTION: A liquid resin composition for underfill contains epoxy resin including bisphenol type epoxy resin, a hardening agent, inorganic filler, and polyester polyol.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a liquid resin composition for underfill, an electronic component device, and a method for manufacturing an electronic component device.

Background Art

[0002] Conventionally, in the field of encapsulating semiconductor elements (hereinafter also referred to as chips) of electronic component devices such as transistors and ICs (Integrated Circuits), resin encapsulation has been the mainstream from the viewpoints of productivity, cost, etc. As an encapsulating material, an epoxy resin composition is widely used. This is because epoxy resin is excellent in balance in various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to insert parts.

[0003] Furthermore, in semiconductor devices with bare chip mounting such as COB (Chip on Board), COG (Chip on Glass), and TCP (Tape Carrier Package), an underfill material is widely used. Also, in a semiconductor device (also referred to as a flip chip) formed by directly bump-connecting a semiconductor element to a wiring board having a substrate such as ceramic, glass epoxy resin, glass imide resin, or polyimide film, a liquid resin composition containing an epoxy resin is used as an underfill material for filling the gap between the bump-connected semiconductor element and the wiring board. These liquid resin compositions containing an epoxy resin play an important role in protecting electronic components from temperature, humidity, mechanical external force, etc.

[0004] As an underfill material containing an epoxy resin, (A-1) 50 to 99 parts by mass of a liquid epoxy resin and / or an epoxy compound having two or more epoxy groups in one molecule, and (A-2) 1 to 50 parts by mass of a monofunctional epoxy compound having a biphenyl structure (however, the total of (A-1) and (A-2) is 100 parts by mass), (B) an amine-based curing agent in an amount such that the molar amount of epoxy groups in component (A) is 0.7 to 1.2 with respect to the molar amount of amino groups in component (B), (C) an inorganic filler in an amount of 50 to 300 parts by mass with respect to 100 parts by mass in total of components (A) and (B), and (D) a silicone microparticle coated with a polyorganosilsesquioxane resin in an amount of 1 to 15 parts by mass with respect to 100 parts by mass in total of components (A) and (B) have been proposed (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When performing flip-chip mounting, since the semiconductor element and the wiring board have different coefficients of thermal expansion, thermal stress is generated at the joint between the semiconductor element and the wiring board, and there is a risk of a decrease in connection reliability. In addition, since the circuit formation surface of the bare chip is not sufficiently protected, moisture, ionic impurities, etc. are likely to penetrate, and there is a risk of a decrease in moisture resistance reliability.

[0007] Also, usually, when sealing the gap between a semiconductor element and a wiring board using an underfill material, a fillet is formed on the side surface of the semiconductor element for protection of the semiconductor element. However, due to the thermal stress caused by the thermal expansion difference between the wiring board and the semiconductor element, there is a risk that cracks may occur in the fillet or the semiconductor element may be destroyed.

[0008] Furthermore, depending on the underfill material selected, the connection may not be sufficiently protected when subjected to repeated thermal shocks during temperature cycles, etc., and the joint may suffer fatigue failure even at low cycles. For example, there is a tendency to improve temperature cycle resistance by lowering the thermal expansion coefficient of the underfill material.

[0009] Against this background, there is an increasing demand for liquid underfill resin compositions with a low thermal expansion coefficient. However, the underfill material described in Patent Document 1 has room for improvement in terms of achieving a low thermal expansion coefficient.

[0010] Furthermore, from the viewpoint of increasing the reflow resistance of the underfill material and improving its resistance to temperature cycles, it is desirable that the modulus of elasticity at high temperatures (for example, 240° C.) be low.

[0011] The present disclosure has been made in consideration of the above circumstances, and aims to provide a liquid underfill resin composition having a low thermal expansion coefficient and a low elastic modulus at high temperatures, an electronic component device using the same, and a method for manufacturing an electronic component device. [Means for solving the problem]

[0012] The means for solving the above problems include the following aspects. <1> an epoxy resin including a bisphenol-type epoxy resin; A hardener; an inorganic filler; A polyester polyol, A liquid resin composition for underfill comprising: <2> The viscosity of the polyester polyol at 75°C is 50 mPa·s to 1500 mPa·s. <1> The liquid resin composition for underfill according to claim 1. <3> The viscosity is 1 Pa·s to 50 Pa·s, measured at 25°C, 10 rpm, and a conversion factor of 0.5 using an EHD rotational viscometer equipped with a cone rotor with a cone angle of 3° and a cone radius of 14 mm. <1> or <2> The liquid resin composition for underfill according to claim 1. <4> The epoxy resin further contains a naphthalene-type diglycidyl ether epoxy resin, and is the liquid resin composition for underfill according to any one of <1> to <3>. <5> The curing agent contains an amine curing agent, and is the liquid resin composition for underfill according to any one of <1> to <4>. <6> The liquid resin composition for underfill according to any one of <1> to <5>, which is used for sealing the connection portion of an electronic component device including an electronic component and a support member electrically connected to the electronic component via a connection portion. <7> An electronic component, a support member electrically connected to the electronic component via a connection portion, and a cured product of the liquid resin composition for underfill according to any one of <1> to <6> that seals the connection portion. An electronic component device comprising: <8> A method for manufacturing an electronic component device, which includes a step of sealing the connection portion between an electronic component and a support member electrically connected to the electronic component via a connection portion with the liquid resin composition for underfill according to any one of <1> to <6>.

Advantages of the Invention

[0013] According to the present disclosure, there are provided a liquid resin composition for underfill having a low coefficient of thermal expansion and a low elastic modulus at high temperature, an electronic component device using the same, and a method for manufacturing an electronic component device.

Embodiments for Carrying Out the Invention

[0014] In the present disclosure, the term "step" includes not only a step independent of other steps but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. In the numerical range indicated by using "~" in the present disclosure, the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple substances corresponding to the component. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, the composition may contain multiple types of particles corresponding to each component. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified. In the present disclosure, "(meth)acrylic" means at least one of acrylic and methacrylic.

[0015] <Liquid resin composition for underfill> The liquid resin composition for underfill (hereinafter also simply referred to as "liquid resin composition") of the present disclosure contains an epoxy resin including a bisphenol-type epoxy resin, a curing agent, an inorganic filler, and a polyester polyol. The underfill liquid resin composition may further contain other components as required.

[0016] In this disclosure, "liquid" means that the material is liquid at room temperature (25°C). Specifically, it means that the viscosity measured with an E-type viscometer at 25°C is 1000 Pa s or less.

[0017] The liquid resin composition of the present disclosure has a low thermal expansion coefficient and a low modulus of elasticity at high temperatures. The reason for this is not entirely clear, but is presumed to be as follows. The liquid resin composition of the present disclosure contains an epoxy resin including a bisphenol-type epoxy resin and a polyester polyol. In the liquid resin composition before curing, the epoxy resin and polyester polyol are in a compatible state, but undergo phase separation upon curing of the liquid resin composition, forming a sea-island phase-separated structure in which the epoxy resin constitutes the sea portion and the polyester polyol constitutes the island portion. It is believed that the dispersion of the polyester polyol in the cured epoxy resin reduces the thermal expansion coefficient and the modulus of elasticity at high temperatures. Note that the above speculation does not limit the present disclosure in any way.

[0018] Hereinafter, each component contained in the liquid resin composition of the present disclosure will be described.

[0019] [Epoxy resin] The liquid resin composition contains an epoxy resin including a bisphenol-type epoxy resin. The epoxy resin may be any commonly used epoxy resin without particular limitation as long as it contains a bisphenol-type epoxy resin, and is preferably an epoxy resin having two or more epoxy groups in one molecule.

[0020] As long as the liquid resin composition as a whole is liquid at room temperature, the epoxy resin may be solid or liquid at room temperature, or a combination of both. From the viewpoint of reducing the viscosity of the liquid resin composition, it is preferable to use an epoxy resin that is liquid at room temperature.

[0021] The liquid resin composition of the present disclosure may contain a solid epoxy resin as long as the desired effects are achieved. In this case, from the viewpoint of fluidity during molding, the content of the solid epoxy resin is preferably 20 mass% or less of the total epoxy resin.

[0022] Examples of bisphenol-type epoxy resins include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol AD-type epoxy resins, bisphenol S-type epoxy resins, etc. From the viewpoint of reducing viscosity, the bisphenol-type epoxy resin is preferably bisphenol F-type epoxy resin. The bisphenol type epoxy resins may be used alone or in combination of two or more.

[0023] The epoxy resin may contain other epoxy resins besides bisphenol-type epoxy resins. Examples of other epoxy resins include diglycidyl ether-type epoxy resins such as hydrogenated bisphenol A; triphenol-type epoxy resins (epoxy resins containing a naphthalene skeleton); epoxidized novolac resins of phenols and aldehydes, such as orthocresol novolac-type epoxy resins; glycidyl ester-type epoxy resins obtained by reacting epichlorohydrin with polybasic acids such as phthalic acid or dimer acid; glycidylamine-type epoxy resins obtained by reacting epichlorohydrin with amine compounds such as p-aminophenol, diaminodiphenylmethane, or isocyanuric acid; linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid; alicyclic epoxy resins; and epoxy resins with a flexible skeleton. The "flexible skeleton" of an epoxy resin refers to a partial structure that imparts flexibility to the epoxy resin, such as an alkylene oxide group, a polyether group, a long-chain alkyl group, an alkylene group, or a siloxane skeleton. The alkylene oxide group includes an ethylene oxide group and an alkylene oxide group. The other epoxy resins may be used alone or in combination of two or more.

[0024] From the viewpoints of heat resistance, adhesiveness, and fluidity, the other epoxy resin preferably includes a liquid glycidyl amine-type epoxy resin. Examples of diglycidyl ether epoxy resins include naphthalene-type diglycidyl ether epoxy resins. Among the naphthalene-type diglycidyl ether epoxy resins, 1,6-bis(glycidyloxy)naphthalene is preferred.

[0025] The glycidylamine type epoxy resin may be bifunctional or trifunctional or higher. From the viewpoint of improving heat resistance after curing, trifunctional or higher glycidylamine type epoxy resins (having three or more epoxy groups in one molecule) are preferred. Examples of bifunctional or higher glycidylamine type epoxy resins include N,N-diglycidylaniline and N,N-diglycidyl-o-toluidine. Examples of trifunctional or higher glycidylamine type epoxy resins include triglycidyl-p-aminophenol and 4,4'-methylenebis[N,N-bis(oxiranylmethyl)aniline]. Among these, triglycidyl-p-aminophenol is preferred from the viewpoint of viscosity at room temperature (e.g., 25°C).

[0026] The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited. From the viewpoint of a balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 70 g / eq to 500 g / eq, more preferably 80 g / eq to 400 g / eq, and even more preferably 90 g / eq to 300 g / eq. In the present disclosure, the epoxy equivalent of the epoxy resin is a value measured by a method in accordance with JIS K 7236:2009.

[0027] The content of the epoxy resin in the liquid resin composition is not particularly limited, but from the viewpoints of viscosity, glass transition temperature, heat resistance, etc., it is preferably 0.5% by mass to 50% by mass, more preferably 2% by mass to 40% by mass, and even more preferably 2% by mass to 30% by mass.

[0028] The content of the bisphenol type epoxy resin in the epoxy resin is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, and even more preferably 70% by mass to 100% by mass, based on the total amount of the epoxy resin.

[0029] When the epoxy resin contains other epoxy resins, for example, when the epoxy resin contains a glycidylamine type epoxy resin, the content of the other epoxy resin or the content of the glycidylamine type epoxy resin is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 40% by mass, and even more preferably 20% by mass to 35% by mass, respectively independently, based on the total epoxy resin.

[0030] [Hardener] The liquid resin composition contains a hardener. As the hardener, a hardener for generally used epoxy resins can be used without particular limitation. For example, amine hardeners, phenol hardeners, acid anhydride hardeners, polymercaptan hardeners, polyaminoamide hardeners, isocyanate hardeners, blocked isocyanate hardeners, etc. can be mentioned. Among them, from the viewpoints of workability and composition properties, at least one selected from the group consisting of amine hardeners, phenol hardeners, and acid anhydride hardeners is preferable, and amine hardeners are more preferable. The hardener may be solid or liquid at room temperature, and is preferably liquid. The hardener may be used alone or in combination of two or more.

[0031] Among them, from the viewpoints of excellent temperature cycle resistance, moisture resistance, etc. and the ability to improve the reliability of electronic component devices, the hardener is preferably an aromatic amine, and more preferably a liquid aromatic amine (also referred to as a liquid aromatic amine) at room temperature. Examples of the liquid aromatic amine include ethyltoluenediamine, diethyltoluenediamine (such as 3,5 - diethyltoluene - 2,4 - diamine and 3,5 - diethyltoluene - 2,6 - diamine), 1 - methyl - 3,5 - diethyl - 2,4 - diaminobenzene, 1 - methyl - 3,5 - diethyl - 2,6 - diaminobenzene, 1,3,5 - triethyl - 2,6 - diaminobenzene, 3,3’ - diethyl - 4,4’ - diaminodiphenylmethane, 3,5,3’,5’ - tetramethyl - 4,4’ - diaminodiphenylmethane, dimethylthiotoluenediamine, etc. The hardener may be used alone or in combination of two or more.

[0032] Among these, from the viewpoint of storage stability, 3,3'-diethyl-4,4'-diaminodiphenylmethane, ethyltoluenediamine, and dimethylthiotoluenediamine are preferred, and the curing agent preferably contains one or a mixture of two or more of these as the main component.

[0033] When a liquid aromatic amine is used as the curing agent, a commonly used curing agent such as a phenolic curing agent, an acid anhydride curing agent, etc. may be used in combination with the liquid aromatic amine. Also, a solid curing agent may be used in combination with the liquid aromatic amine.

[0034] The functional group equivalent of the curing agent is not particularly limited. From the viewpoint of reactivity and composition properties, the functional group equivalent is preferably 30 g / eq to 300 g / eq, and more preferably 35 g / eq to 200 g / eq. The functional group equivalent of the curing agent is a value measured by a method in accordance with JIS K 0070:1992.

[0035] The amount of curing agent to be blended relative to the epoxy resin is not particularly limited. In order to minimize the amount of unreacted components, the equivalent ratio of the epoxy resin to the curing agent, i.e., the ratio of the number of functional groups in the curing agent to the number of epoxy groups in the epoxy resin (number of functional groups in the curing agent / number of epoxy groups in the epoxy resin), is preferably 0.5 to 2.0, more preferably 0.6 to 1.8, and even more preferably 0.7 to 1.5.

[0036] [Inorganic filler] The liquid resin composition contains an inorganic filler. Examples of inorganic fillers include silica (e.g., spherical silica, crystalline silica, fused silica), calcium carbonate, clay, alumina, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, and other powders, as well as beads or glass fibers formed from these. Furthermore, flame-retardant inorganic fillers such as aluminum hydroxide, magnesium hydroxide, zinc borate, and zinc molybdate may also be used. The inorganic fillers may be used alone or in combination of two or more. Among these, silica is preferred from the viewpoints of availability, chemical stability, and material cost. Spherical silica is more preferred from the viewpoints of fluidity and penetration of the liquid resin composition into fine gaps. Examples of spherical silica include silica obtained by a deflagration method and fused silica. The inorganic filler may be surface-treated in advance with various surface treatment agents such as the silane coupling agent described below.

[0037] The volume average particle size of the inorganic filler is not particularly limited. For example, in the case of spherical silica, the volume average particle size is preferably 0.1 μm to 10 μm, more preferably 0.2 μm to 7 μm, even more preferably 0.3 μm to 5 μm, and may be 0.3 μm to 1.3 μm. A volume average particle size of 0.1 μm or more tends to provide excellent dispersibility in the liquid resin composition, to be less likely to impart thixotropy to the liquid resin composition, and to have excellent flow properties. A volume average particle size of 10 μm or less tends to reduce sedimentation of the inorganic filler in the liquid resin composition, to improve the permeability and flowability of the liquid resin composition into fine gaps, and to prevent voids and unfilled particles. The volume average particle size of the inorganic filler can be measured as the particle size (D50) at which the cumulative total from the smallest diameter side reaches 50% in the volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer.

[0038] The content of the inorganic filler is not particularly limited, and is preferably 30% by mass or more of the total liquid resin composition, more preferably 40% by mass or more, even more preferably 50% by mass or more, and may even be 60% by mass or more. Furthermore, the content of the inorganic filler is preferably 80% by mass or less of the total liquid resin composition, preferably 75% by mass or less, and even more preferably 70% by mass or less. When the content of the inorganic filler is 30% by mass or more, the thermal expansion coefficient is easily reduced, and when it is 80% by mass or less, an increase in the viscosity of the liquid resin composition is easily suppressed, and the fluidity, penetration, and dispensability tend to be improved.

[0039] In particular, the content of the inorganic filler is preferably 50% by mass to 75% by mass, and more preferably 55% by mass to 70% by mass, based on the total mass of the liquid resin composition.

[0040] [Polyester polyol] The liquid resin composition contains a polyester polyol. The polyester polyol is not particularly limited as long as it is a compound containing a structural unit derived from a polyester and a structural unit derived from a polyol. The polyester polyol may be, for example, a compound obtained by reacting a polyol with a carboxylic acid or an anhydride thereof. The polyester polyol may or may not contain structural units other than the structural units derived from a polyester and the structural units derived from a polyol.

[0041] From the viewpoint of the fluidity and thermal expansion coefficient of the liquid resin composition, the viscosity of the polyester polyol at 75°C is preferably 50 mPa·s to 1500 mPa·s, more preferably 60 mPa·s to 1000 mPa·s, and even more preferably 80 mPa·s to 500 mPa·s. The viscosity of the polyester polyol is a value measured by a Brookfield viscometer.

[0042] The number average molecular weight of the polyester polyol is not particularly limited and may be, for example, from 1000 to 10000, may be from 1200 to 5000, or may be from 1500 to 2500. The number average molecular weight of the polyester polyol is a value measured by the gel permeation chromatography (GPC) method.

[0043] The content of the polyester polyol is not particularly limited, and is preferably 1% by mass to 20% by mass, more preferably 3% by mass to 17% by mass, and even more preferably 4% by mass to 13% by mass with respect to the whole of the epoxy resin and the curing agent.

[0044] [Coupling agent] The liquid resin composition may contain a coupling agent as needed. When the liquid resin composition contains a coupling agent, the interfacial adhesion between the epoxy resin and the inorganic filler or between the epoxy resin and the constituent members of the electronic component tends to be strengthened. There is no particular limitation on the type of the coupling agent, and conventionally known ones can be used. For example, various silane compounds such as silane compounds having a primary and / or secondary and / or tertiary amino group, epoxy silane, mercapto silane, alkyl silane, ureido silane, vinyl silane, (meth)acrylic silane, titanium compounds, aluminum chelates, aluminum / zirconium compounds, etc. can be mentioned. The coupling agent may be used alone or in combination of two or more.

[0045] As the coupling agent, for example, a monomer or an oligomer may be used. Examples of the monomer coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, glycidoxy octyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, γ-(N,N-dimethyl)aminopropyltrimethoxysilane, γ-(N,N-diethyl)aminopropyltrimethoxysilane, γ-(N,N-dibutyl)aminopropyltrimethoxysilane, γ-(N-methyl)anilinopropyltrimethoxysilane, γ-(N-ethyl)anilinopropyltrimethoxysilane, γ-(N,N-dimethyl)aminopropyltriethoxysilane, γ-(N,N-diethyl)aminopropyltriethoxysilane, γ-(N,N-dibutyl)aminopropyltriethoxysilane, γ-(N-methyl)anilinopropyltriethoxysilane, γ-(N-ethyl)anilinopropyltriethoxysilane, γ-(N,N-dimethyl)aminopropylmethyldimethoxysilane, γ-(N,N-diethyl)aminopropylmethyldimethoxysilane, γ-(N,N-dibutyl)aminopropylmethyldimethoxysilane, γ-(N-methyl)anilinopropylmethyldimethoxysilane, γ-(N-ethyl)anilinopropylmethyldimethoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, Silane coupling agents such as methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, vinyltrimethoxysilane, hexenyltrimethoxysilane, octenyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, methacryloxyoctyltrimethoxysilane, etc.; titanate coupling agents such as isopropyltriisostearoyl titanate, isopropyltris(dioctylpyrophosphate) titanate, isopropyltri(N-aminoethyl-aminoethyl) titanate, tetraoctylbis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl) phosphite titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearyldiacryl titanate, isopropyltri(dioctyl phosphate) titanate, isopropyltricumylphenyl titanate, tetraisopropylbis(dioctyl phosphite) titanate, etc. are included.

[0046] In addition, as the oligomer coupling agent, there are mentioned alkoxy oligomers modified with methyl, methyl / phenyl, propyl / phenyl, epoxy, mercapto, amine, (meth)acrylic, or polyester resin.

[0047] The content rate of the coupling agent in the liquid resin composition is not particularly limited. From the viewpoints of adhesiveness, fluidity, etc., the content rate of the coupling agent is preferably 0.01 mass% to 20 mass%, more preferably 0.01 mass% to 10 mass% with respect to the total amount of the epoxy resin.

[0048] [Other Components] In addition to the above-mentioned components, the liquid resin composition may contain various additives such as a plasticizer, a surfactant, a curing accelerator, an ion exchanger, etc. In addition to the additives exemplified below, the liquid resin composition may also contain various additives known in the art, as needed.

[0049] (flexibilizer) The liquid resin composition may contain various flexible agents from the viewpoints of improving thermal shock resistance and reducing stress on semiconductor elements. The type of flexible agent is not particularly limited, and those commonly used in the relevant field, such as silicone rubber, acrylic elastomer, and phenoxy resin, may be used. Among these, rubber particles are preferred as the flexible agent. Examples of rubber particles include particles of styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), butadiene rubber (BR), urethane rubber (UR), and acrylic rubber (AR). One type of flexible agent may be used alone, or two or more types may be used in combination.

[0050] (surfactant) The liquid resin composition may contain a surfactant. One type of surfactant may be used alone, or two or more types may be used in combination. An example of the surfactant is a silicone-modified epoxy resin. The silicone-modified epoxy resin can be obtained as a reaction product between an organosiloxane having a functional group reactive with an epoxy group and an epoxy resin. The silicone-modified epoxy resin is preferably liquid at room temperature.

[0051] Examples of the organosiloxane having a functional group reactive with an epoxy group include dimethylsiloxane, diphenylsiloxane, methylphenylsiloxane, etc., each having one or more amino groups, carboxyl groups, hydroxyl groups, phenolic hydroxyl groups, mercapto groups, etc. in one molecule. The weight average molecular weight of the organosiloxane having a functional group reactive with an epoxy group is not particularly limited, and is preferably 500 to 5000. When the weight average molecular weight is 500 or more, the compatibility with the resin system does not become too high, and the effect as an additive is easily exhibited. When the weight average molecular weight is 5000 or less, since it is compatible with the resin component, separation, bleeding, etc. are suppressed during the molding of the silicone-modified epoxy resin, and the adhesiveness and appearance tend to be less impaired.

[0052] The epoxy resin for obtaining the silicone-modified epoxy resin is not particularly limited as long as it is compatible with the resin component of the liquid resin composition, and an epoxy resin generally used in the liquid resin composition can be used. Examples of the epoxy resin for obtaining the silicone-modified epoxy resin include glycidyl ether type epoxy resins obtained by reacting bisphenol A, bisphenol F, bisphenol AD, bisphenol S, naphthalene diol, hydrogenated bisphenol A, etc. with epichlorohydrin; novolak type epoxy resins obtained by epoxidizing novolak resins obtained by condensing or co-condensing phenols and aldehydes such as orthocresol novolak type epoxy resins; glycidyl ester type epoxy resins obtained by reacting polybasic acids such as phthalic acid and dimer acid with epichlorohydrin; glycidyl amine type epoxy resins obtained by reacting polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; linear aliphatic epoxy resins obtained by oxidizing an olefin bond with a peracid such as peracetic acid; alicyclic epoxy resins, etc. The epoxy resin for obtaining the silicone-modified epoxy resin may be used alone or in combination of two or more. As the epoxy resin for obtaining the silicone-modified epoxy resin, an epoxy resin that is liquid at room temperature is preferred.

[0053] The content of the surfactant in the liquid resin composition is not particularly limited, and is preferably 0.01% by mass to 1.5% by mass, and more preferably 0.05% by mass to 1% by mass, based on the total mass of the liquid resin composition. If the content is 0.01% by mass or more, the surfactant tends to exert its effect more easily, and if it is 1.5% by mass or less, bleeding from the surface of the cured product during curing tends to be suppressed, and adhesive strength tends to be improved.

[0054] (curing accelerator) The liquid resin composition may contain a curing accelerator as needed. The type of curing accelerator is not particularly limited, and conventionally known accelerators can be used. Examples of the curing accelerator include cycloamidine compounds such as 1,8-diaza-bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, and 5,6-dibutylamino-1,8-diaza-bicyclo[5.4.0]undecene-7; tertiary amine compounds such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; 2-methylimidazole, 2-ethyl imidazolyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine, 2-heptadecylimidazole, and the like. organic phosphines such as trialkyl phosphines such as tributylphosphine, dialkylaryl phosphines such as dimethylphenylphosphine, alkyldiaryl phosphines such as methyldiphenylphosphine, triphenylphosphine, alkyl group-substituted triphenylphosphine, and compounds having intramolecular polarization obtained by adding to these compounds quinone compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, diazophenylmethane, and phenol resins, and compounds having a π bond; phenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate; and derivatives thereof. A latent curing accelerator may also be used. Examples of latent curing accelerators include core-shell particles in which a core is a compound having an amino group that is solid at room temperature and a shell is made of an epoxy compound that is solid at room temperature. Examples of such core-shell particles include commercially available products such as Amicure (trade name, manufactured by Ajinomoto Co., Inc.) and Novacure (trade name, manufactured by Asahi Kasei Chemicals Corporation), in which microencapsulated amine is dispersed in a bisphenol A epoxy resin or a bisphenol F epoxy resin. One type of curing accelerator may be used alone, or two or more types may be used in combination.

[0055] The content of the curing accelerator is not particularly limited as long as it is an amount that achieves the curing acceleration effect, and is preferably 0.1% by mass to 40% by mass, and more preferably 1% by mass to 20% by mass, relative to the epoxy resin. When the content of the curing accelerator is 0.1% by mass or more relative to the epoxy resin, excellent curing properties tend to be obtained even in a short time, while when it is 40% by mass or less, it tends to be easy to control the curing rate and storage stability such as pot life and shell life.

[0056] Furthermore, in order to promote the condensation reaction of the coupling agent and the reaction between the silanol groups in the coupling agent and the silanol groups of an inorganic filler such as silica, thereby improving the dispersibility of the inorganic filler and reducing the viscosity of the liquid resin composition, a catalyst such as an acid that supplies protons, a Lewis acid, or the like may be added. Among these, as the Lewis acid, a chelating agent containing a metal species is preferred from the viewpoint of storage stability. Examples of the chelating agent containing a metal species include chelating agents of aluminum, boron, cobalt, titanium, etc. The content of the Lewis acid is preferably 0.001 to 1.0 part by mass, more preferably 0.002 to 0.8 part by mass, and even more preferably 0.005 to 0.6 part by mass, relative to 100 parts by mass of the inorganic filler.

[0057] (ion exchanger) The liquid resin composition may contain an ion exchanger as necessary. When the liquid resin composition contains an ion exchanger, the migration resistance, moisture resistance, characteristics of being left at body temperature, etc. of semiconductor elements such as ICs tend to be improved. Examples of the ion exchanger include compounds represented by the following compositional formula (I) or (II). Mg 1-X Al X (OH)2(CO3) X / 2 ·mH2O ···(I) (0<X≦0.5, m is a positive number) BiO x (OH) y (NO3) z ···(II) (0.9≦x≦1.1, 0.6≦y≦0.8, 0.2≦z≦0.4)

[0058] As the addition amount of the ion exchanger, 0.1 mass% to 3.0 mass% is preferable, and more preferably 0.3 mass% or more and 1.5 mass% or less. The volume average particle diameter of the ion exchanger is preferably from 0.1 μm to 3.0 μm. The volume average particle diameter of the ion exchanger can be measured as the particle diameter (D50) at which the cumulative from the small diameter side becomes 50% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measuring device. The maximum particle diameter of the ion exchanger is preferably 10 μm.

[0059] Examples of the compound represented by the above formula (I) include DHT-4A (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.), which is a commercially available product. Examples of the compound represented by the above formula (II) include IXE500 (trade name, manufactured by Toagosei Co., Ltd.), which is a commercially available product. Further, other anion exchangers may be added as necessary. The type of the anion exchanger is not particularly limited, and conventionally known ones can be used. For example, hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony, etc. can be mentioned. The ion exchanger may be used alone or in combination of two or more.

[0060] (Other additives) The liquid resin composition may be blended with, as other additives, colorants such as dyes and carbon black, diluents, leveling agents, defoaming agents, etc. as necessary.

[0061] [Method for Preparing Liquid Resin Composition] The resin liquid composition may be prepared by any method as long as various components can be dispersed and mixed with high uniformity. For example, it can be obtained by weighing the components, mixing and kneading them using a kneader, a mixing roll, a planetary mixer, etc., and defoaming as necessary.

[0062] [Physical Properties of Liquid Resin Composition] (Viscosity) The viscosity of the liquid resin composition is not particularly limited. The viscosity of the liquid resin composition at 25°C, 10 rpm, with a conversion coefficient of 0.5, measured using an EHD type rotational viscometer equipped with a cone rotor with a cone angle of 3° and a cone radius of 14 mm, is preferably, for example, from 1 Pa·s to 50 Pa·s, more preferably from 3 Pa·s to 30 Pa·s, and even more preferably from 3 Pa·s to 20 Pa·s from the viewpoint of fluidity.

[0063] Also, from the viewpoint of filling property when filling a liquid resin composition in the vicinity of 100°C to 120°C between narrow gaps for applications such as underfill materials, the viscosity of the liquid resin composition at 110°C is preferably, for example, 0.3 Pa·s or less, and more preferably 0.2 Pa·s or less. The viscosity of the liquid resin composition at 110°C is measured using a rheometer. Specifically, it can be measured by the method described in the examples.

[0064] [Physical Properties of Cured Product of Liquid Resin Composition] In the measurement of the coefficient of thermal expansion, elastic modulus, and glass transition temperature of the cured product of the liquid resin composition described below, the cured product is assumed to be obtained by heating the liquid resin composition at 165°C for 2 hours.

[0065] (Coefficient of Linear Expansion) The linear expansion coefficient of the liquid resin composition when cured is not particularly limited. For example, when the temperature is increased from 0°C to 300°C at a rate of 5°C / min by compression, the linear expansion coefficient (CTE1) is determined as the slope of the tangent from 10°C to 30°C. The linear expansion coefficient (CTE1) is preferably less than 29 ppm / °C, more preferably 28 ppm / °C or less, even more preferably 27 ppm / °C or less, and particularly preferably 26 ppm / °C or less. When the linear expansion coefficient at or below the glass transition temperature is less than 29 ppm / °C, the occurrence of bump cracks during reflow tends to be suppressed and the temperature cycle resistance tends to be improved. The thermal expansion coefficient at or below the glass transition temperature may be 15 ppm / °C or more. The thermal expansion coefficient at or below the glass transition temperature can be measured by TMA (thermomechanical analysis). Specifically, it can be measured by the method described in the Examples.

[0066] Generally, when the elastic modulus of a liquid resin composition decreases, the linear expansion coefficient tends to increase. Therefore, it is generally difficult to suppress the linear expansion coefficient while decreasing the elastic modulus. However, the liquid resin composition of the present disclosure tends to be able to suppress the linear expansion coefficient while decreasing the elastic modulus. Therefore, it is believed that the liquid resin composition of the present disclosure can effectively improve temperature cycle resistance.

[0067] (elastic modulus) The elastic modulus of the liquid resin composition when cured is not particularly limited. From the viewpoint of reflow resistance, the elastic modulus at 240°C of the liquid resin composition of the present disclosure when cured is preferably 0.10 GPa or less, more preferably 0.08 GPa or less, even more preferably 0.06 GPa or less, particularly preferably less than 0.05 GPa, and extremely preferably 0.04 GPa or less. The elastic modulus of the liquid resin composition when cured can be measured by DMA (dynamic viscoelasticity measurement), specifically by the method described in the examples.

[0068] (glass transition temperature) When the liquid resin composition is made into a cured product, the glass transition temperature (Tg) is not particularly limited, preferably 60°C to 150°C, more preferably 70 to 140°C, and even more preferably 80 to 140°C. When the glass transition temperature is 60°C or higher, the protection of bumps at high temperatures is high and the occurrence of wire breaks tends to be less likely. When the glass transition temperature is 150°C or lower, the warpage at room temperature (25°C) tends to be less likely to increase. The glass transition temperature of the cured product can be measured by a thermomechanical analyzer (TMA). Specifically, it can be measured by the method described in the examples.

[0069] [Use of the liquid resin composition] In one embodiment, the liquid resin composition of the present disclosure is used to seal the connection portion of an electronic component device including an electronic component and a support member electrically connected to the electronic component via a connection portion. Details of the configuration and sealing method of the electronic component device will be described later.

[0070] ≪Electronic component device and method for manufacturing an electronic component device≫ The electronic component device of the present disclosure includes an electronic component, a support member electrically connected to the electronic component via a connection portion, and a cured product of the liquid resin composition for underfill of the present disclosure that seals the connection portion. The method for manufacturing an electronic component device of the present disclosure includes a step of sealing the connection portion between an electronic component and a support member electrically connected to the electronic component via a connection portion with the liquid resin composition for underfill of the present disclosure.

[0071] Examples of the electronic component include active elements such as semiconductor chips, transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, resistor arrays, coils, and switches. The size of the electronic component is not particularly limited, and as an example, a semiconductor chip having a length of 20 mm and a width of 20 mm can be mentioned. Further, the liquid resin composition of the present disclosure has excellent reliability as an underfill material even when the size of the semiconductor chip is larger.

[0072] Examples of the support member include a lead frame, a wired tape carrier, a wiring board (rigid or flexible), glass, a silicone wafer, and the like.

[0073] In the electronic component device of the present disclosure, the electronic component and the support member are electrically connected via a connection portion. Examples of the connection portion include bumps. As the bump, for example, a bump using a copper pillar may be used. Packages having bumps using copper pillars have been increasingly used in thinner or higher-density packages. However, generally, defects such as peeling after temperature cycling, cracking, and peeling after moisture absorption heat resistance test tend to occur. However, since the liquid resin composition of the present disclosure is used in the electronic component device of the present disclosure, even a package using copper pillars has excellent temperature cycle resistance.

[0074] Examples of the electronic component device include a flip-chip type semiconductor device obtained by flip-chip bonding an electronic component on a support member by bump connection. Examples of the flip-chip type semiconductor device include BGA (Ball Grid Array), LGA (Land Grid Array), COF (Chip On Film), and the like.

[0075] The electronic component device may be a high-density or large-sized electronic component device. Generally, as the electronic component device becomes higher in density or larger in size, when the size of the electronic component increases, or the diameter of the bump becomes smaller, the pitch becomes narrower, and the gap becomes narrower due to multi-pinning, defects such as peeling and cracking after temperature cycling tend to occur. However, since the liquid resin composition of the present disclosure is used in the electronic component device of the present disclosure, even a high-density or large-sized electronic component device has excellent temperature cycle resistance.

[0076] In the electronic component device of the present disclosure, the connection portion is sealed with a cured product of the liquid resin composition of the present disclosure. The sealing method is not particularly limited, and examples thereof include a dispensing method, a casting method, and a printing method.

Examples

[0077] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0078] <Preparation of Liquid Resin Composition> The components used in the liquid resin compositions of the Examples and Comparative Examples are shown below. <Epoxy resin> Epoxy resin 1: Bisphenol F type liquid epoxy resin with an epoxy equivalent of 160g / eq Epoxy resin 2: Triglycidyl-p-aminophenol, epoxy equivalent: 95g / eq Epoxy resin 3: 1,6-bis(glycidyloxy)naphthalene, epoxy equivalent: 143g / eq Epoxy resin 4: A bifunctional liquid epoxy resin with an epoxy equivalent of 135 g / eq and containing alkylene groups.

[0079] <Amine curing agent> Curing agent 1: Liquid amine resin with an active hydrogen equivalent of 63g / eq Curing agent 2: Liquid amine resin with an active hydrogen equivalent of 45g / eq

[0080] Inorganic filler: silica with a maximum particle size of 25 μm and a volume average particle size of 0.5 μm The volume average particle size of the inorganic filler is the median diameter (D50), and this volume average particle size is a value measured by a laser diffraction scattering particle size distribution analyzer. Colorant: Carbon black Polyester polyol 1 (number average molecular weight: approximately 2000) Polyester polyol 2 (number average molecular weight: approximately 2000) Polyester polyol 3 (number average molecular weight: approximately 2000)

[0081] The components were mixed in the compositions shown in Tables 1 and 2, and the mixture was kneaded and dispersed using a three-roll mill and a vacuum crusher to prepare liquid resin compositions for the Examples and Comparative Examples.

[0082] <Evaluation of flow characteristics> (Viscosity at 25°C) The viscosity at 25°C of the prepared liquid resin composition was determined by rotating an EHD type rotational viscometer at 25°C for 1 minute at predetermined revolutions per minute (10 rpm, 5 rpm, 2.5 rpm, 1 rpm), and multiplying the measured value at that time by a predetermined conversion coefficient. The above-mentioned measured value was obtained using an EHD type rotational viscometer equipped with a cone rotor with a cone angle of 3° and a cone radius of 14 mm for the composition maintained at 25 ± 1°C. The revolutions per minute and the conversion coefficient were determined according to an approximate estimation of the viscosity of the composition to be measured in advance. When the estimated value of the viscosity of the composition to be measured was 0 Pa·s or more and less than 50 Pa·s, the rotation speed was 10 rpm and the conversion coefficient was 0.5; when the estimated value of the viscosity was 50 Pa·s or more and less than 100 Pa·s, the rotation speed was 5 rpm and the conversion coefficient was 1; when the estimated value of the viscosity was 100 Pa·s or more and less than 200 Pa·s, the rotation speed was 2.5 rpm and the conversion coefficient was 2; when the estimated value of the viscosity was 200 Pa·s or more and less than 500 Pa·s, the rotation speed was 1 rpm and the conversion coefficient was 5.

[0083] (Viscosity at 110°C) The viscosity at 110°C of the prepared liquid resin composition was measured using AR2000 (trade name, manufactured by TA Instruments). Measurement was carried out under the conditions of a 40 mm parallel plate and a shear rate of 32.5 (1 / s) to measure the viscosity at 110°C.

[0084] (Evaluation of coefficient of thermal expansion (CTE1)) The liquid resin composition was cured at 165°C for 2 hours. The cured product was cut into a size of φ8 mm × 20 mm to prepare test pieces. Using the test pieces and a thermomechanical analyzer (trade name: TMA2940, manufactured by TA Instruments), heating rate measurement was carried out from 0°C to 300°C at 5°C / min by the compression method, and the slope of the tangent line at 10°C to 30°C was defined as CTE1.

[0085] (Evaluation of elastic modulus) The liquid resin composition was cured at 165°C for 2 hours. The cured product was cut into a size of 60 mm x 10 mm x 2 mm to prepare a test piece. Using the test piece and a viscoelasticity measuring device (trade name: RSAIII, manufactured by TA Instruments), the temperature was raised from 0°C to 300°C at a rate of 3°C / min using a three-point bending method under conditions of a span distance of 40 mm and a frequency of 1 Hz. The storage modulus at 240°C was taken as the high-temperature modulus.

[0086] <Glass transition temperature> The liquid resin composition was cured at 165°C for 2 hours to prepare a test piece. Measurement was carried out using the same equipment and conditions as in the evaluation of the thermal expansion coefficient, and the temperature corresponding to the intersection of the tangent lines at 50°C and 150°C was taken as the glass transition temperature (°C).

[0087] <Flow time evaluation> A flow path measuring 1.5 mm wide and 25 μm high was created by sandwiching a 25 μm thick spacer manufactured by Tokyo Thickness Co., Ltd. between two pieces of glass. After placing this horizontally on a hot plate at 110°C, underfill material was dropped into the opening of the flow path and the time it took for the material to penetrate into the flow path to a depth of 20 mm was measured.

[0088] [Table 1]

[0089] [Table 2]

[0090] The content of the curing agent (equivalent ratio) represents the number of functional groups in the curing agent when the number of epoxy groups in the epoxy resin is taken as 1. The content of the inorganic filler represents the content (% by mass) of the inorganic filler relative to the total amount of the composition. Regarding the content of the polyester polyol, the % by mass relative to the resin component means the % by mass relative to the total of the epoxy resin, curing agent, and polyester polyol.

[0091] As a result of the evaluation, in the examples containing the polyester polyol of the present disclosure with the same combination of epoxy resin and curing agent, a liquid resin composition having a lower CTE1 and modulus of elasticity at 240 °C was obtained than in the comparative examples not containing the polyester polyol.

Claims

1. An epoxy resin containing a bisphenol type epoxy resin, a curing agent, an inorganic filler, a polyester polyol, and contains wherein the number average molecular weight of the polyester polyol is 1000 to 2500, and the content of the polyester polyol is 1% by mass to 20% by mass based on the whole of the epoxy resin and the curing agent, a liquid resin composition for underfill.

2. The liquid resin composition for underfill according to claim 1, wherein the viscosity of the polyester polyol at 75 ° C is 50 mPa·s to 1500 mPa·s.

3. The liquid resin composition for underfill according to claim 1 or claim 2, wherein the viscosity at 25 ° C, 10 rpm, and a conversion coefficient of 0.5, measured using an EHD type rotational viscometer equipped with a cone rotor having a cone angle of 3 ° and a cone radius of 14 mm, is 1 Pa·s to 50 Pa·s.

4. The liquid resin composition for underfill according to any one of claims 1 to 3, wherein the epoxy resin further contains a naphthalene type diglycidyl ether epoxy resin.

5. The liquid resin composition for underfill according to any one of claims 1 to 4, wherein the curing agent contains an amine curing agent.

6. The liquid resin composition for underfill according to any one of claims 1 to 5, which is used for sealing the connection part of an electronic component device including an electronic component and a support member electrically connected to the electronic component via a connection part.

7. An electronic component device comprising an electronic component, a support member electrically connected to the electronic component via a connection part, and a cured product of the liquid resin composition for underfill according to any one of claims 1 to 6 that seals the connection part.

8. A method for manufacturing an electronic component device, comprising a step of sealing the connection part between an electronic component and a support member electrically connected to the electronic component via a connection part with the liquid resin composition for underfill according to any one of claims 1 to 6.

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