Underfill material, electronic component device, and method for manufacturing an electronic component device

Abstract

To provide an underfill material that prevents cracking of a solder resist in reflowing, and has excellent temperature cycle resistance.SOLUTION: An underfill material contains (A) an epoxy resin, (B) a curing agent and (C) an inorganic filler. When made into a cured product, the underfill material shows a thermal expansion coefficient of 30 ppm / °C or less, at a glass transition temperature or lower, measured by TMA (thermomechanical analysis), and shows a storage elastic modulus of 0.10 GPa or less, at 240°C, measured by DMA (dynamic mechanical analysis).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an underfill material, an electronic component device, and a method for manufacturing an electronic component device.

Background Art

[0002] Conventionally, in the field of element encapsulation of electronic component devices such as transistors, ICs (Integrated Circuits), and LSIs (Large Scale Integration), a method of encapsulating using an encapsulating material containing a resin has been mainstream from the viewpoints of productivity, cost, etc. As the encapsulating material, an epoxy resin composition is widely used. This is because the epoxy resin has a balance of various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to insert parts.

[0003] In electronic component 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 as an encapsulant. Also, in an electronic component device (flip chip) formed by directly bump-connecting an electronic component such as a semiconductor element onto a wiring board having a substrate such as ceramic, glass epoxy resin, glass imide resin, or polyimide film, an epoxy resin composition is used as an underfill material for filling the gap between the bump-connected electronic component and the wiring board. The underfill material plays an important role in protecting the electronic component from temperature, humidity, and mechanical external forces.

[0004] Here, in order to provide a sealing epoxy resin composition excellent in moisture-resistant adhesive strength and low stress properties, and an electronic component device having high reliability (moisture resistance, thermal shock resistance) with an element sealed thereby, there is disclosed a sealing epoxy resin composition containing (A) a liquid epoxy resin, (B) a curing agent containing a liquid aromatic amine, (C) rubber particles, and (D) an inorganic filler, and an electronic component device having an element sealed with this sealing epoxy resin composition (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the progress of semiconductor technology is remarkable, and the size of semiconductors and wiring boards is increasing, and the wiring boards are becoming thinner. Therefore, in the flip - chip method that performs bump connection, if the elastic modulus of the cured product of the underfill material at the reflow temperature is high, the cured product of the underfill material cannot follow the expansion of the bumps, and stress tends to concentrate on the solder resist formed on the wiring board. When stress concentrates on the solder resist, cracks may occur in the solder resist on the wiring board due to the expansion of the bumps during reflow. The elastic modulus of the cured product of the underfill material can be lowered by reducing the amount of the inorganic filler contained in the underfill material. However, if the amount of the inorganic filler is reduced too much, the coefficient of thermal expansion increases, and problems may occur due to the expansion, contraction, etc. of the cured product of the underfill material in the temperature cycle test.

[0007] As described above, with the progress of semiconductor technology, various problems need to be solved for the underfill material. The present invention has been made in view of such circumstances, and provides an underfill material in which the occurrence of cracks in a solder resist during reflow is suppressed and which has excellent temperature cycle resistance characteristics, as well as a highly reliable electronic component device sealed therewith and a method for manufacturing the same.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have made the composition of the underfill material include (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, and when it is made into a cured product, the coefficient of thermal expansion below the glass transition temperature measured by TMA (thermomechanical analysis) is 30 ppm / °C or less, and the storage elastic modulus at 240°C measured by DMA (dynamic viscoelasticity measurement) is 0.10 GPa or less, and have found that the above object can be achieved, thus completing the present invention.

[0009] The present invention relates to the following. <1> An underfill material containing (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, wherein the coefficient of thermal expansion below the glass transition temperature measured by TMA (thermomechanical analysis) when made into a cured product is 30 ppm / °C or less, and the storage elastic modulus at 240°C measured by DMA (dynamic viscoelasticity measurement) is 0.10 GPa or less. <2> The underfill material according to <1>, wherein the glass transition temperature measured by TMA (thermomechanical analysis) when made into a cured product is 60°C to 150°C. <3> The underfill material according to <1> or <2>, wherein the storage elastic modulus at 25°C measured by DMA (dynamic viscoelasticity measurement) when made into a cured product is 5 GPa to 10 GPa. <4> The underfill material according to any one of <1> to <3>, further containing (D) a flexibilizer. <5> The underfill material according to any one of <1> to <4>, further containing (E) a surfactant. <6> The underfill material according to any one of <1> to <5>, further containing (F) an ion trap agent. <7> The underfill material according to any one of <1> to <6>, further containing (G) a curing accelerator. <8> The underfill material according to any one of <1> to <7>, further containing (H) a coupling agent. <9> The underfill material according to any one of <1> to <8>, further containing (I) an antioxidant. <10> The underfill material according to any one of <1> to <9>, further containing (J) an organic solvent, wherein the content of the organic solvent is 10% by mass or less. <11> The underfill material according to any one of <1> to <10>, wherein the (B) curing agent is an aromatic amine compound. <12> A wiring board, An electronic component disposed on the wiring board and electrically connected to the wiring board via a connection portion, At least a cured product of the underfill material according to any one of <1> to <11> that seals the connection portion between the wiring board and the electronic component, And an electronic component device comprising the same. <13> The electronic component device according to <12>, wherein the connection portion does not contain lead. <14> The electronic component device according to <12> or <13>, wherein the connection portion contains copper. <15> A method for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion, comprising: A supply step of supplying the underfill material according to any one of <1> to <11> to at least one of the surface of the electronic component facing the wiring board and the surface of the wiring board facing the electronic component; A connection step of connecting the electronic component and the wiring board via the connection portion and curing the underfill material. <16> A method for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion, comprising: A filling step of filling a gap between the connected electronic component and the wiring board with the underfill material according to any one of <1> to <11>. A method for manufacturing an electronic component device, comprising a curing step of curing the underfill material.

Advantages of the Invention

[0010] According to the present invention, there are provided an underfill material in which the occurrence of cracks in the solder resist during reflow is suppressed and which has excellent temperature cycle resistance characteristics, a highly reliable electronic component device sealed thereby, and a method for manufacturing the same.

Embodiments for Carrying Out the Invention

[0011] In this specification, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the intended purpose of the step is achieved. In addition, in this specification, a numerical range indicated by using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In this specification, the content rate of each component in the composition means the total content rate of the plurality of substances corresponding to each component in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified. In this specification, the particle diameter of each component in the composition means a value for a mixture of the plurality of types of particles present in the composition when there are a plurality of types of particles corresponding to each component in the composition, unless otherwise specified. In this specification, the term "layer" or "film" includes not only the case where it is formed over the entire region where the layer or film exists but also the case where it is formed only in a part of the region when observing the region where the layer or film exists.

[0012] <Underfill Material> The underfill material of the present disclosure contains (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, and when formed into a cured product, has a coefficient of thermal expansion of 30 ppm / °C or less below the glass transition temperature measured by TMA (thermomechanical analysis) and a storage elastic modulus of 0.10 GPa or less at 240°C measured by DMA (dynamic viscoelasticity measurement).

[0013] Each component constituting the underfill material of the present disclosure will be described below.

[0014] ((A) Epoxy resin) The epoxy resin as component (A) used in the present disclosure is not particularly limited as long as it has one or more epoxy groups in one molecule, and an epoxy resin generally used in underfill materials can be used. The type of epoxy resin used in the present disclosure is not particularly limited. Examples of epoxy resins include glycidyl ether type epoxy resins obtained by reacting bisphenol A, bisphenol F, bisphenol AD, bisphenol S, hydrogenated bisphenol A, naphthalene diol, alkyldiol, etc. with epichlorohydrin, novolac type epoxy resins obtained by epoxidizing novolac resins obtained by condensing or co-condensing phenols and aldehydes typified by orthocresol novolac 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 amine compounds such as aminophenol, diaminodiphenylmethane, and isocyanuric acid with epichlorohydrin, linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid, alicyclic epoxy resins, etc. These may be used alone or in combination of two or more. Among them, from the viewpoint of fluidity, a liquid bisphenol type epoxy resin which is one type of glycidyl ether type epoxy resin is preferable, and a liquid glycidyl amine type epoxy resin is preferable from the viewpoints of heat resistance, adhesiveness, and fluidity.

[0015] Either of the above two epoxy resins may be used alone or in combination of two. The blending ratio is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more based on the total amount of the epoxy resin in order to exhibit its performance. In addition, a solid epoxy resin can also be used in combination with the underfill material of the present disclosure as long as the effects of the present disclosure are achieved. From the viewpoint of the fluidity of the underfill material, the solid epoxy resin used in combination is preferably 20% by mass or less based on the total amount of the epoxy resin.

[0016] In order to make the coefficient of thermal expansion below the glass transition temperature measured by TMA (thermomechanical analysis) of the underfill material as a cured product 30 ppm / °C or less, the proportion of the epoxy resin containing an aromatic ring in the molecule in the total amount of the epoxy resin is preferably 65% by mass or more, and more preferably 70% by mass or more. In order to make the storage elastic modulus at 240°C measured by DMA (dynamic viscoelasticity measurement) of the underfill material as a cured product 0.10 GPa or less, the proportion of the trifunctional or higher epoxy resin in the total amount of the epoxy resin is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

[0017] The liquid epoxy resin means an epoxy resin that is liquid at normal temperature (25°C). Specifically, it means that the viscosity measured with an E-type viscometer at 25°C is 1000 Pa·s or less. Specifically, the above viscosity is measured using an E-type viscometer EHD type (cone angle 3°, cone diameter 28 mm), measurement temperature: 25°C, sample volume: 0.7 ml. After setting the rotation speed according to the assumed viscosity of the sample with reference to the following, the value after 1 minute from the start of measurement is taken as the measured value. (1) When the assumed viscosity is 100 Pa·s to 1000 Pa·s: Rotation speed 0.5 revolutions / min (2) When the assumed viscosity is less than 100 Pa·s: Rotation speed 5 revolutions / min In addition, the solid epoxy resin means an epoxy resin that is solid at normal temperature (25°C).

[0018] The purity of the epoxy resin, particularly the amount of hydrolyzable chlorine, is preferably low because it is related to the corrosion of aluminum wiring on elements such as ICs. In order to obtain an underfill material with excellent moisture resistance, the amount of hydrolyzable chlorine in the epoxy resin is preferably 500 ppm or less. Here, the amount of hydrolyzable chlorine is based on the value obtained by dissolving 1 g of the epoxy resin of the sample in 30 ml of dioxane, adding 5 ml of 1N-KOH methanol solution, refluxing for 30 minutes, and then performing potentiometric titration.

[0019] From the viewpoint of viscosity adjustment, the epoxy equivalent of the epoxy resin is preferably 90 g / eq to 450 g / eq, more preferably 90 g / eq to 350 g / eq, and even more preferably 90 g / eq to 250 g / eq. The epoxy equivalent of the epoxy resin is measured by dissolving the weighed epoxy resin in a solvent such as methyl ethyl ketone, adding acetic acid and tetraethylammonium acetate bromide solution, and then performing potentiometric titration with a perchloric acid acetic acid standard solution. An indicator may be used for this titration.

[0020] The content of the epoxy resin is not particularly limited. For example, as a proportion in the solid content of the underfill material, it is preferably 10% by mass to 50% by mass, more preferably 15% by mass to 45% by mass, and even more preferably 20% by mass to 40% by mass. In the present disclosure, the "solid content" of the underfill material means the remaining components after removing volatile components such as organic solvents from the underfill material.

[0021] ((B) Curing agent) The curing agent of the component (B) used in the present disclosure is not particularly limited. Examples of amines having an aromatic ring (aromatic amine compounds) as a curing agent include diethyltoluenediamine, 1,3,5-triethyl-2,6-diaminobenzene, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane, and the like. These aromatic amine compounds are commercially available as Epikure-W, Epikure-Z (trade names of Mitsubishi Chemical Corporation), Kayahard A-A, Kayahard A-B, Kayahard A-S (trade names of Nippon Kayaku Co., Ltd.), Totaamine HM-205 (trade name of Nippon Steel & Sumikin Chemical Co., Ltd.), Adeka Hardener EH-101 (trade name of Adeka Corporation), Epomic Q-640, Epomic Q-643 (trade names of Mitsui Chemicals, Inc.), DETDA80 (trade name of Lonza), etc., and these may be used alone or in combination of two or more.

[0022] When using an aromatic amine compound as a curing agent, from the viewpoint of the storage stability of the underfill material, for example, 3,3'-diethyl-4,4'-diaminodiphenylmethane and diethyltoluenediamine are preferable as the aromatic amine compound. Examples of diethyltoluenediamine include 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine. When using an aromatic amine compound as a curing agent, those containing 50% by mass or more of 3,3'-diethyl-4,4'-diaminodiphenylmethane or 3,5-diethyltoluene-2,4-diamine are preferable as the curing agent.

[0023] Examples of the hardener include acid anhydrides such as phthalic anhydride, maleic anhydride, methyl hymic anhydride, hymic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, chlorendic anhydride, methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride maleic acid adduct, benzophenonetetracarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, hydrogenated methyl nadic anhydride, trialkyltetrahydrophthalic anhydride obtained by Diels-Alder reaction from maleic anhydride and diene compounds, dodecenyl succinic anhydride, and various other acid anhydrides. These may be used alone or in combination of two or more.

[0024] When an acid anhydride is used as the hardener, from the viewpoint of reducing the viscosity of the underfill material, for example, tetrahydrophthalic anhydride and hexahydrophthalic anhydride are preferable as the acid anhydride. When an acid anhydride is used as the hardener, it is preferable that the hardener contains 50% by mass or more of tetrahydrophthalic anhydride or hexahydrophthalic anhydride.

[0025] In addition, in the underfill material, within the range where the effects of the present disclosure are achieved, in addition to aromatic amine compounds and acid anhydrides, hardeners generally used in underfill materials such as phenolic hardeners can be used in combination. As the hardener, an aromatic amine compound is preferable because the cured product is less likely to be hydrolyzed and has good moisture resistance reliability.

[0026] The equivalent ratio of the equivalent number of epoxy resin to the equivalent number of curing agent (equivalent number of curing agent / equivalent number of epoxy resin) contained in the underfill material is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, and even more preferably 0.9 to 1.1. If the ratio is 0.7 or more, there will be no shortage of curing agent, the amount of epoxy resin not participating in the reaction will decrease, and there will be a tendency for the reliability to be less likely to decrease. On the other hand, if the ratio is 1.3 or less, the excess curing agent will decrease, so the glass transition temperature will not become too high, and the elastic modulus of the cured product at high temperatures will not become too high, so there will be a tendency for warpage at normal temperature and high temperatures to be less likely to occur.

[0027] ((C) Inorganic filler) Examples of the inorganic filler of component (C) used in the present disclosure include silica such as spherical silica and crystalline 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, or beads obtained by spheroidizing these, glass fibers and the like. Furthermore, examples of inorganic fillers having a flame retardant effect include aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate and the like. These inorganic fillers may be used alone or in combination of two or more. Among them, spherical silica is more preferable from the viewpoints of fluidity and penetrability into the fine gaps of the underfill material.

[0028] The average particle size of the inorganic filler is preferably in the range of 0.05 μm to 20 μm, more preferably in the range of 0.2 μm to 10 μm, particularly in the case of spherical silica. If the average particle size is 0.05 μm or more, the dispersibility in the liquid resin is improved and the viscosity is less likely to increase, and the flow characteristics of the underfill material tend to be improved. If the average particle size is 20 μm or less, there is a tendency for sedimentation to be less likely to occur, and the penetrability and fluidity into the fine gaps as the underfill material are improved, and the occurrence of voids and unfilled underfill material is less likely to occur. Here, the average particle size is the particle size corresponding to 50% by volume when a cumulative frequency distribution curve by particle size is obtained with the total volume of the particles being 100%, and it can be measured using a particle size distribution measuring device such as a laser diffraction scattering method.

[0029] The content rate of the inorganic filler is preferably in the range of 20 mass% to 90 mass%, more preferably 30 mass% to 85 mass%, and still more preferably 40 mass% to 80 mass% as the ratio in the solid content of the underfill material. If the content rate is 20 mass% or more, the coefficient of thermal expansion is less likely to decrease, and the underfill material cured product has a tendency to be more excellent in temperature cycle resistance. If it is 90 mass% or less, the viscosity of the underfill material is less likely to increase, and there is a tendency that the fluidity, permeability, and dispensability are less likely to decrease.

[0030] ((D) Flexibilizer) For the underfill material of the present disclosure, various flexibilizers can be blended from the viewpoints of improving heat shock resistance, reducing stress on electronic components such as semiconductor elements, and the like. The flexibilizer is not particularly limited, but rubber particles are preferred. Examples of the rubber particles include rubber particles of silicone rubber and rubber particles of synthetic rubber other than silicone rubber (hereinafter sometimes simply referred to as "synthetic rubber"). Examples of the rubber particles of synthetic rubber include rubber particles of styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), butadiene rubber (BR), urethane rubber (UR), acrylic rubber (AR), and the like. Among them, rubber particles of acrylic rubber are preferred from the viewpoints of heat resistance and moisture resistance, and core-shell type acrylic polymer, that is, core-shell type acrylic rubber particles are more preferred.

[0031] Also, examples of the rubber particles of silicone rubber include silicone rubber particles obtained by crosslinking polyorganosiloxanes such as linear polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane; those in which the surface of the silicone rubber particles is coated with a silicone resin; core-shell polymer particles having a core of solid silicone particles obtained by emulsion polymerization or the like and a shell of a polymer such as an acrylic resin; spherical silicone particles in which the surface of dimethyl-type solid silicone rubber particles is modified with an epoxy group, and the like. These silicone rubber particles can be used regardless of whether they are amorphous or spherical in shape. In order to keep the viscosity related to the moldability of the underfill material low, it is preferable to use spherical ones. Commercially available products of these silicone rubber particles can be obtained from Toray Dow Corning Co., Ltd., Shin-Etsu Chemical Co., Ltd., and the like.

[0032] The average particle size of these flexibilizers is preferably small in order to uniformly modify the underfill material, and it is preferably in the range of 0.05 μm to 10 μm, more preferably in the range of 0.1 μm to 5 μm. If the average particle size is 0.05 μm or more, the dispersibility in the underfill material tends to be excellent, and if it is 10 μm or less, the stress tends to decrease. Furthermore, the permeability and fluidity into the fine gaps as the underfill material are improved, and the occurrence of voids and unfilled underfill material is less likely to occur.

[0033] The content of the flexibilizer is preferably set in the range of 1% by mass to 30% by mass, more preferably 2% by mass to 20% by mass, based on the total amount of the epoxy resin. If the content of the flexibilizer is 1% by mass or more, the effect of reducing stress tends to be improved, and if it is 30% by mass or less, the viscosity of the underfill material is less likely to increase, and the moldability (flow characteristics, etc.) tends to be excellent.

[0034] ((E) Surfactant) In the underfill material of the present disclosure, various surfactants can be blended from the viewpoints of reducing the generation of voids during molding and improving the adhesion by improving the wettability to various adherends. There are no particular restrictions on the surfactant, but nonionic surfactants are preferred. Examples of polyoxyalkylene alkyl ether surfactants such as polyoxyethylene alkyl ether surfactants, sorbitan fatty acid ester surfactants, polyoxyethylene sorbitan fatty acid ester surfactants, polyoxyethylene sorbitol fatty acid ester surfactants, glycerin fatty acid ester surfactants, polyoxyethylene fatty acid ester surfactants, polyoxyethylene alkylamine surfactants, alkyl alkanolamide surfactants, polyether-modified silicone surfactants, aralkyl-modified silicone surfactants, polyester-modified silicone surfactants, polyacrylic surfactants, etc. These surfactants can be used alone or in combination of two or more. Commercially available products of these surfactants can be obtained from companies such as BYK-Chemie Japan Co., Ltd. and Kao Corporation.

[0035] In addition, a silicone-modified epoxy resin can be added as a surfactant. The silicone-modified epoxy resin can be obtained as a reaction product of an organosiloxane having a functional group that reacts with an epoxy group and an epoxy resin. The silicone-modified epoxy resin is preferably liquid at room temperature (25°C). Examples of the organosiloxane having a functional group that reacts with an epoxy group include dimethylsiloxane, diphenylsiloxane, methylphenylsiloxane, etc. having one or more amino groups, carboxy groups, hydroxyl groups, phenolic hydroxyl groups, mercapto groups, etc. in one molecule. The weight average molecular weight of the organosiloxane is preferably in the range of 500 to 5000. If the weight average molecular weight of the organosiloxane is 500 or more, the compatibility with an epoxy resin or the like does not improve too much, and the effect as an additive is likely to be exhibited. If the weight average molecular weight of the organosiloxane is 5000 or less, it is less likely to be incompatible with an epoxy resin or the like. Therefore, when curing the underfill material, the silicone-modified epoxy resin is less likely to separate or ooze out from the underfill material, and there is a tendency that problems such as impairing adhesiveness or appearance are less likely to occur. The weight-average molecular weight of the organosiloxane is determined by conversion using a calibration curve of standard polystyrene from the molecular weight distribution measured using GPC (gel permeation chromatography).

[0036] As the epoxy resin for obtaining the silicone-modified epoxy resin, there is no particular limitation as long as it is compatible with the resin system of the underfill material, and an epoxy resin generally used in the underfill material can be used. Examples of the epoxy resin include glycidyl ether type epoxy resins obtained by the reaction of bisphenol A, bisphenol F, bisphenol AD, bisphenol S, naphthalene diol, hydrogenated bisphenol A, etc. with epichlorohydrin; novolac type epoxy resins obtained by epoxidizing novolac resins obtained by condensing or co-condensing phenols and aldehydes typified by orthocresol novolac type epoxy resins; glycidyl ester type epoxy resins obtained by the reaction of polybasic acids such as phthalic acid and dimer acid with epichlorohydrin; glycidyl amine type epoxy resins obtained by the reaction of amine compounds such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid; alicyclic epoxy resins, etc. These can be used alone or in combination of two or more, but those in a liquid state at normal temperature (25 °C) are preferred.

[0037] The content of the surfactant is preferably 0.01% by mass to 1.5% by mass, more preferably 0.05% by mass to 1% by mass or less, based on the total epoxy resin. If the content of the surfactant is 0.01% by mass or more, a sufficient addition effect is likely to be obtained. If it is 1.5% by mass or less, bleeding of the surfactant from the surface of the cured product is less likely to occur when curing the underfill material, and a decrease in adhesive strength is less likely to occur.

[0038] ((F) Ion trap agent) In the underfill material of the present disclosure, an ion trap agent can be blended as necessary from the viewpoint of improving migration resistance, moisture resistance, and high-temperature storage characteristics, as long as the filling property and fluidity during application to an electronic component device are not impaired. There are no particular restrictions on the ion trap agent, and conventionally known ones can be used. Hydrotalcite represented by the following compositional formula (I) or hydrated bismuth oxide represented by the following compositional formula (II) is preferable.

[0039] Mg 1-X Al X (OH) 2 (CO 3 ) X / 2 ·mH 2 O (I) (In compositional formula (I), 0 < X ≦ 0.5, and m represents a positive number.) BiO a (OH) b (NO 3 ) c (II) (In compositional formula (II), a, b, and c are 0.9 ≦ a ≦ 1.1, 0.6 ≦ b ≦ 0.8, and 0.2 ≦ c ≦ 0.4, respectively.)

[0040] The content of the ion trap agent is preferably 0.1% by mass to 3.0% by mass, more preferably 0.3% by mass to 1.5% by mass, based on the total amount of the epoxy resin. The average particle size of the ion trap agent is preferably 0.1 μm to 3.0 μm, and the maximum particle size is preferably 10 μm or less. The compound represented by the above compositional formula (I) is available as a commercial product under the trade name DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd. The compound represented by the above compositional formula (II) is available as a commercial product under the trade name IXE-500 (manufactured by Toagosei Co., Ltd.). Optionally, other anion exchangers can also be blended as the ion trapping agent. There is no particular limitation on the anion exchanger, and conventionally known ones can be used. Examples of the ion trapping agent include hydrated oxides such as magnesium, aluminum, titanium, zirconium, and antimony, and these can be used alone or in combination of two or more.

[0041] ((G) Curing accelerator) In the underfill material of the present disclosure, various curing accelerators can be blended from the viewpoint of accelerating the curing reaction between the epoxy resin and the curing agent. The curing accelerator is not particularly limited as long as it can accelerate the reaction between the epoxy resin and the curing agent, and conventionally known ones can be used. Examples of the curing accelerator include cycloamidine compounds such as 1,8-diazabicyclo(5.4.0)undecene-7, 1,5-diazabicyclo(4.3.0)nonene, 5,6-dibutylamino-1,8-diazabicyclo(5.4.0)undecene-7; tertiary amine compounds such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; imidazole compounds such as 2-methylimidazole, 2-ethyl-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; organic phosphines such as trialkylphosphines like tributylphosphine, dialkylarylphosphines like dimethylphenylphosphine, alkyldiarylphosphines like methyldiphenylphosphine, triarylphosphines like triphenylphosphine and alkyl group-substituted triphenylphosphine; compounds having intramolecular polarization formed by adding 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, phenyl-1,4-benzoquinone, compounds having a π bond such as diazophenylmethane and phenol resin, and derivatives thereof; and phenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate. These can be used alone or in combination of two or more.In addition, as a curing accelerator having potentiality, there are core-shell particles formed by coating a shell of an epoxy compound that is solid at normal temperature (25°C) with a compound having an amino group that is solid at normal temperature (25°C) as a core. As commercial products, Amicure (trade name, manufactured by Ajinomoto Co., Inc.), Novacure (trade name, manufactured by Asahi Kasei Corporation) in which microencapsulated amine is dispersed in bisphenol A type epoxy resin and bisphenol F type epoxy resin to impart potentiality, etc. can be used.

[0042] Among them, an imidazole derivative is preferable from the viewpoint of the balance between the curing acceleration action and reliability. 2-Phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, which are imidazole derivatives having a phenyl group and a hydroxyl group as substituents, and Novacure (trade name, manufactured by Asahi Kasei Corporation) in which microencapsulated amine is dispersed in bisphenol A type epoxy resin and bisphenol F type epoxy resin to impart potentiality are more preferable, and 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole are even more preferable.

[0043] The content of the curing accelerator is not particularly limited as long as the curing acceleration effect is achieved, but a range of 0.2% by mass to 5% by mass is preferable, and a range of 0.5% by mass to 3% by mass is more preferable, with respect to the mass of the total epoxy resin. If the content of the curing accelerator is 0.2% by mass or more, the addition effect of the curing accelerator is sufficiently exhibited, and as a result, the generation of voids when curing the underfill material can be suppressed, and the warpage reduction effect also tends to be sufficient. If it is 5% by mass or less, it tends to have excellent storage stability.

[0044] ((H) Coupling agent) In the underfill material of the present disclosure, a coupling agent can be blended for the purpose of strengthening the adhesion at the interface between the epoxy resin and the inorganic filler, or between the epoxy resin and the constituent members of the electronic component device. There are no particular restrictions on the coupling agent, and conventionally known ones can be used. Examples of the coupling agent include silane compounds having at least one selected from the group consisting of primary amino groups, secondary amino groups, and tertiary amino groups, various silane-based compounds such as epoxy silane, mercapto silane, alkyl silane, ureido silane, vinyl silane, titanium-based compounds, aluminum chelates, zirconium-based compounds, and the like. Exemplifying these, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, 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,Silane coupling agents such as (N-dibutyl) aminopropylmethyldimethoxysilane, γ-(N-methyl) anilinopropylmethyldimethoxysilane, γ-(N-ethyl) anilinopropylmethyldimethoxysilane, N-(trimethoxysilylpropyl) ethylenediamine, N-(dimethoxymethylsilylisopropyl) ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.; titanate coupling agents such as isopropyltriisostearoyl titanate, isopropyltris (dioctyl pyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, tetraoctylbis (ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl) bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyldiacryl titanate, isopropyltri (dioctyl phosphate) titanate, isopropyltricumylphenyl titanate, tetraisopropylbis (dioctyl phosphite) titanate, etc. may be mentioned, and these may be used alone or in combination of two or more kinds.,

[0045] The content rate of the coupling agent is preferably 0.1 mass% to 10 mass%, more preferably 1 mass% to 5 mass% with respect to the whole epoxy resin.

[0046] ((I) Antioxidant) An antioxidant can be blended in the underfill material of the present disclosure. Conventionally known antioxidants can be used as the antioxidant. As phenolic compound-based antioxidants, as compounds having at least one alkyl group at the ortho position of the phenol nucleus, 2,6-di-t-butyl-4-methylphenol, n-octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-t-butylphenol), 3,9-bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-butylidenebis-(6-t-butyl-3-methylphenol), 4,4'-thiobis(6-t-butyl-3-methylphenol), tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, 2,2'-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], isooctyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 4,6-bis(dodecylthiomethyl)-o-cresol, bis[3,5-di-t-butyl-4-hydroxybenzyl(ethoxy)phosphinate]calcium, 2,4-1-bis[(octylthio)methyl]-o-cresol, 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenz[d,f][1,3,2]dioxaphosphepine, 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6-di-t-pentylphenyl acrylate, 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), 2,6-di-t-butyl-4-ethylphenol, 1,1,3-Tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, triethylene glycol-bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, diethyl [〔3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl〕methyl]phosphonate, 2,5,7,8-tetramethyl-2-(4’,8’,12’-trimethyltridecyl)chroman-6-ol, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine and the like can be mentioned., Examples of the organic sulfur compound-based antioxidant include dilauryl-3,3’-thiodipropionate, dimyristyl-3,3’-thiodipropionate, distearyl-3,3’-thiodipropionate, pentaerythrityl tetrakis(3-laurylthiopropionate), ditridecyl-3,3’-thiodipropionate, 2-mercaptobenzimidazole, 4,4’-thiobis(6-t-butyl-3-methylphenol), 2,2’-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 4,6-bis(dodecylthiomethyl)-o-cresol, 2,4-1-bis[(octylthio)methyl]-o-cresol, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine and the like can be mentioned., Examples of the amine compound-based antioxidant include N,N’-diallyl-p-phenylenediamine, N,N’-di-sec-butyl-p-phenylenediamine, octylated diphenylamine, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine and the like can be mentioned., Among amine compound-based antioxidants, as dicyclohexylamine, products such as D-CHA-T manufactured by Shin Nippon Rika Co., Ltd. are available as commercial products. As its derivatives, dicyclohexylamine nitrite ammonium, N,N-di(3-methyl-cyclohexyl)amine, N,N-di(2-methoxy-cyclohexyl)amine, N,N-di(4-bromo-cyclohexyl)amine, etc. can be mentioned. As phosphorus compound-based antioxidants, tris(nonylphenyl) phosphite, triphenyl phosphite, calcium bis[3,5-di-t-butyl-4-hydroxybenzyl(ethoxy)phosphinate], tris(2,4-di-t-butylphenyl) phosphite, 2-[〔2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl〕oxy]-N,N-bis[2-{〔2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl〕oxy}-ethyl]ethanamine, 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenz[d,f][1,3,2]dioxaphosphepin, diethyl [〔3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl〕methyl]phosphonate, etc. can be mentioned. The antioxidants may be used alone or in combination of two or more. In addition to phenolic hydroxyl groups, as specific examples of antioxidants, there are compounds containing at least one of a phosphorus atom, a sulfur atom, and an amine in the same molecule, but these compounds may be listed repeatedly.

[0047] The content of the antioxidant is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, based on the total amount of the epoxy resin.

[0048] ((J) Organic solvent) The underfill material of the present disclosure can be blended with an organic solvent as needed to reduce the viscosity. In particular, when using a solid epoxy resin and a curing agent, it is preferable to blend an organic solvent in order to obtain a liquid underfill material. There is no particular limitation on the organic solvent, and examples include alcohol solvents such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol; ketone solvents such as acetone and methyl ethyl ketone; glycol ether solvents such as ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol ethyl ether, and propylene glycol methyl ether acetate; lactone solvents such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone; amide solvents such as dimethylacetamide and dimethylformamide; and aromatic solvents such as toluene and xylene. These can be used alone or in combination of two or more. Among these, from the viewpoint of avoiding bubble formation due to rapid volatilization during curing of the underfill material, an organic solvent having a boiling point of 170°C or higher is preferable.

[0049] The blending of the organic solvent is not particularly limited as long as it does not form bubbles during curing of the underfill material, but it is preferably 10% by mass or less, more preferably 5% by mass or less, based on the entire underfill material.

[0050] (Other Additives) As other additives, the underfill material of the present disclosure can be blended with a dye, a colorant such as carbon black, a diluent, a leveling agent, an antifoaming agent, etc. as needed.

[0051] (Physical Properties of Underfill Material) The viscosity of the underfill material is not particularly limited. From the perspective of high fluidity, it is preferably 1 Pa·s to 100 Pa·s at 25°C, and more preferably 3 Pa·s to 70 Pa·s. The viscosity of the underfill material is measured at 25°C using an E-type viscometer (cone angle 3°, rotation speed 10 revolutions / min).

[0052] Also, as an index of the ease of filling when filling the underfill material between narrow gaps of several tens of μm to several hundreds of μm around 100°C to 120°C, the viscosity at 110°C is preferably 0.3 Pa·s or less, and more preferably 0.2 Pa·s or less. The viscosity of the underfill material at 110°C is measured using a rheometer AR2000 (manufactured by TA Instruments, aluminum cone 40 mm, shear rate 32.5 / sec).

[0053] Also, for the underfill material, the thixotropic index [(viscosity at 1.5 revolutions / min) / (viscosity at 10 revolutions / min)], which is the ratio of the viscosity at a rotation speed of 1.5 revolutions / min and the viscosity at a rotation speed of 10 revolutions / min measured at 25°C using an E-type viscometer, is preferably 0.3 to 1.1, and more preferably 0.4 to 1.0. When the thixotropic index is within the above range, the fillet formation property is further improved. The viscosity and thixotropic index of the underfill material can be set within a desired range by appropriately selecting the composition of the epoxy resin, the content of the inorganic filler, etc.

[0054] (Physical properties of the cured product) In the present disclosure, the cured product of the underfill material used for measuring the glass transition temperature and coefficient of thermal expansion by TMA and the storage modulus by DMA is obtained by heating the underfill material at 150°C for 2 hours.

[0055] The coefficient of thermal expansion below the glass transition temperature measured by TMA (Thermomechanical Analysis) when the underfill material is a cured product is 30 ppm / °C or less, preferably 28 ppm / °C or less, and more preferably 26 ppm / °C or less. If the coefficient of thermal expansion below the glass transition temperature is 30 ppm / °C or less, the occurrence of bump cracks during reflow is suppressed, and the temperature cycle resistance characteristics are improved. The coefficient of thermal expansion below the glass transition temperature measured by TMA (Thermomechanical Analysis) may be 15 ppm / °C or more. The storage modulus at 240 °C measured by DMA (Dynamic Viscoelasticity Measurement) when the underfill material is a cured product is 0.10 GPa or less, preferably 0.09 GPa or less, more preferably 0.08 GPa or less, and even more preferably 0.07 GPa or less. If the storage modulus at 240 °C is 0.10 GPa or less, the occurrence of cracks in the solder resist during reflow is suppressed, and the temperature cycle resistance characteristics are improved. The storage modulus at 240 °C measured by DMA (Dynamic Viscoelasticity Measurement) may be 0.02 GPa or more. The glass transition temperature measured by TMA (Thermomechanical Analysis) when the underfill material is a cured product is preferably 60 °C to 150 °C, more preferably 70 °C to 140 °C, and even more preferably 70 °C to 130 °C or less. If the glass transition temperature is 60 °C or higher, the protection of the bumps at high temperatures is high and the occurrence of wire breaks tends to be reduced. Also, when the glass transition temperature is 150 °C or lower, the warpage at room temperature (25 °C) tends not to increase significantly. The storage modulus at 25 °C measured by DMA (Dynamic Viscoelasticity Measurement) when the underfill material is a cured product is preferably 5 GPa to 10 GPa, more preferably 5.5 GPa to 9.5 GPa, and even more preferably 6 GPa to 9 GPa. If the storage modulus at 25 °C is 5 GPa or more, the protection of the bumps at high temperatures is high and the occurrence of wire breaks tends to be reduced. Also, when the elastic modulus at 25 °C is 10 GPa or less, the warpage at room temperature (25 °C) tends not to increase significantly.

[0056] The measurement of TMA can be performed, for example, using a TA4000SA manufactured by TA Instruments. As the measurement conditions, the temperature rising condition can be set to 5°C / min. The measurement of DMA can be performed, for example, using a Q800 manufactured by TA Instruments. As the measurement conditions, the frequency can be set to 1 Hz and the temperature rising condition can be set to 3°C / min.

[0057] (Manufacture of Underfill Material) The underfill material of the present disclosure can be manufactured using any method as long as the above various components can be uniformly dispersed and mixed. As a general method, components at a predetermined blending ratio are weighed and mixed using a kneader, a mixing roll, a planetary mixer, etc., kneaded, and defoamed as necessary to obtain an underfill material.

[0058] <Electronic Component Device> The electronic component device of the present disclosure includes a wiring board, an electronic component disposed on the wiring board and electrically connected to the wiring board via a connection portion, and at least a cured product of the underfill material of the present disclosure that seals the connection portion between the wiring board and the electronic component. The electronic component device of the present disclosure can be obtained by sealing at least the connection portion between the electronic component and the wiring board with the underfill material of the present disclosure. By sealing the electronic component with the underfill material, the electronic component device of the present disclosure is excellent in reliability such as temperature cycle resistance. In order to ensure high conductivity, the connection portion in the electronic component device preferably has a configuration containing copper.

[0059] Examples of the electronic component device include an electronic component device obtained by mounting electronic components such as semiconductor chips, transistors, diodes, thyristors and other active elements, capacitors, resistors, resistor arrays, coils, switches and other passive elements on wiring boards such as lead frames, wired tape carriers, rigid wiring boards, flexible wiring boards, glass, and silicon wafers, and sealing necessary portions with the underfill material of the present disclosure. In particular, it is preferable that a semiconductor device in which a semiconductor element is flip-chip bonded to a rigid wiring board, a flexible wiring board, or wiring formed on glass by bump connection is sealed with the underfill material of the present disclosure. Specific examples of the flip-chip bonded semiconductor device include semiconductor devices such as flip-chip BGA (Ball Grid Array), LGA (Land Grid Array), and COF (Chip On Film).

[0060] The underfill material of the present disclosure is suitable as an underfill material for flip-chip with excellent reliability. The field of flip-chip to which the underfill material of the present disclosure is particularly preferably applied is a field of flip-chip semiconductor components in which the material of the bumps connecting the wiring board and the semiconductor element is not a conventional lead-containing solder but a lead-free solder such as Sn-Ag-Cu based solder. The connection part in the electronic component device may have a lead-free configuration. The underfill material of the present disclosure can maintain good reliability even for a flip-chip with bump connection using a lead-free solder that is physically brittle compared to conventional lead solder. Furthermore, it is suitable for an element with a semiconductor element size of 2 mm or more on the longer side, and also shows good fluidity and filling properties for a flip-chip connection with a distance between the wiring board and the bump connection surface of the semiconductor element constituting the electronic component device of 200 μm or less, and can provide a semiconductor device with excellent reliability such as moisture resistance and heat shock resistance. In recent years, a low dielectric constant interlayer insulating film may be formed on a semiconductor element with the increase in speed of the semiconductor element. These low dielectric constant insulators have weak mechanical strength and are prone to failure due to breakage by external stress. This tendency becomes more prominent as the semiconductor element becomes larger, and reduction of stress by an underfill material is required. The underfill material of the present disclosure can provide excellent reliability even for a flip-chip semiconductor device mounting a semiconductor element having an interlayer insulating film with a semiconductor element size of 2 mm or more on the longer side and a dielectric constant of 3.0 or less.

[0061] <Method for manufacturing an electronic component device> As a method for encapsulating an electronic component device using the underfill material of the present disclosure, a dispensing method, a casting method, a printing method, etc. can be mentioned. The underfill material of the present disclosure is suitably used for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion. For example, the manufacturing method of the first electronic component device of the present disclosure includes a supply step of supplying the underfill material of the present disclosure to at least one of the surface of the electronic component facing the wiring board and the surface of the wiring board facing the electronic component, and a connection step of connecting the electronic component and the wiring board via a connection portion and curing the underfill material. In the manufacturing method of the first electronic component device, the underfill material of the present disclosure can be used as an underfill material of the pre-supply method. Further, the manufacturing method of the second electronic component device of the present disclosure includes a filling step of filling the gap between the connected electronic component and the wiring board with the underfill material of the present disclosure, and a curing step of curing the underfill material. In the manufacturing method of the second electronic component device, the underfill material of the present disclosure can be used as an underfill material of the post-supply method.

Example

[0062] Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[0063] The evaluation methods of various properties and reliability of the underfill material performed in the examples are summarized below.

[0064] The semiconductor element used for the evaluation has a length of 25 mm, a width of 25 mm, and a thickness of 725 μm, the bumps are copper with a height of 30 μm + lead-free solder with a height of 15 μm, the bump pitch is 150 μm, and the number of bumps is 25,921. As the wiring board, E-705 (product name manufactured by Hitachi Chemical Co., Ltd.) with a length of 55 mm, a width of 55 mm, and a thickness of 1 mm was used. The solder resist was AUS703 (product name manufactured by Taiyo Ink Manufacturing Co., Ltd.) with a thickness of 15 μm.

[0065] The electronic component device was fabricated by filling the gap between the semiconductor element and the wiring board, in a state where the semiconductor element and the wiring board are electrically connected via bumps, with an underfill material by a dispensing method and curing it at 150 °C for 2 hours. Also, the curing conditions for various test pieces were carried out under the same conditions.

[0066] (1) Glass transition temperature For the cured product of the underfill material, TMA (Thermomechanical Analysis) was performed using TA4000SA manufactured by TA Instruments, and the intersection of the tangents before and after the inflection point of the obtained chart was defined as the glass transition temperature. The heating rate was 5 °C / min. (2) Coefficient of thermal expansion For the cured product of the underfill material, TMA (Thermomechanical Analysis) was performed using TA4000SA manufactured by TA Instruments, and the value obtained by dividing the slope connecting two points at 10 °C and 30 °C of the obtained chart by the test piece length was defined as the coefficient of thermal expansion. The heating rate was 5 °C / min. (3) Storage modulus For the cured product of the underfill material, DMA (Dynamic Viscoelastic Measurement) was performed using Q800 manufactured by TA Instruments, and the storage modulus at 240 °C was obtained from the measurement results. The frequency was 1 Hz and the heating rate was 3 °C / min. (4) Solder resist crack The electronic component device that had undergone a thermal history of 1 minute or more at a temperature of 240 °C or higher three times was cut so that the bump portion could be observed, and the presence or absence of solder resist cracks was observed with a scanning electron microscope (model name SU1510) manufactured by Hitachi High-Technologies Corporation. (5) Temperature cycle After performing a temperature cycle test with -55 °C / 10 min and 125 °C / 10 min as one cycle, the electronic component device was observed using an ultrasonic microscope (model name IS-350) manufactured by Insight Co., Ltd., and the presence or absence of peeling of the cured product of the underfill material was observed. “>1000” in Table 2 indicates that no peeling occurred at the end of 1000 cycles. Also, <500 indicates that peeling occurred at the end of 500 cycles.

[0067] (Examples 1 to 5 and Comparative Examples 1 and 2) As the epoxy resin of component (A), a liquid diepoxy resin (epoxy resin 1) with an epoxy equivalent of 160 g / eq obtained by epoxidizing bisphenol F, a trifunctional liquid epoxy resin (epoxy resin 2) with an epoxy equivalent of 95 g / eq obtained by epoxidizing aminophenol, a diepoxy resin (epoxy resin 3) with an epoxy equivalent of 140 g / eq obtained by epoxidizing naphthalene diol, and a liquid diepoxy resin (epoxy resin 4) with an epoxy equivalent of 128 g / eq obtained by epoxidizing alkyldiol were used. As the curing agent of component (B), 3,5 - diethyltoluene - 2,4 - diamine with an active hydrogen equivalent of 45 g / eq was used. As the inorganic filler of component (C), spherical silica with an average particle size of 1 μm was used. As the flexibilizer of component (D), spherical silicone particles with an average particle size of 2 μm, in which the surface of dimethyl - type solid silicone rubber particles was modified with epoxy groups, were used. As the surfactant of component (E), a silicone - modified epoxy resin, which is a reaction product of an organosiloxane having a functional group reactive with an epoxy group with a weight - average molecular weight of 1000 and a bisphenol F - type epoxy resin, was used. As the ion trap agent of component (F), a bismuth - based ion trap agent (trade name IXE - 500 manufactured by Toagosei Co., Ltd.) was used. As the curing accelerator of component (G), 2 - phenyl - 4 - methyl - 5 - hydroxymethylimidazole was used. As the coupling agent of component (H), γ - glycidoxypropyltrimethoxysilane was used. As the antioxidant of component (I), 3,9 - bis[2 - [3 - (3 - t - butyl - 4 - hydroxy - 5 - methylphenyl)propionyloxy]-1,1 - dimethylethyl]-2,4,8,10 - tetraoxaspiro[5.5]undecane was used. As the organic solvent of component (J), γ - butyrolactone was used. As the colorant, carbon black (trade name MA - 100 manufactured by Mitsubishi Chemical Corporation) was used. Each of the above components was blended in the composition shown in Table 1 below, kneaded and dispersed using a three-roll mill and a kneader capable of reducing pressure, and underfill materials of Examples 1 to 5 and Comparative Examples 1 and 2 were produced.

[0068]

Table 1

[0069] Note that the unit of the blending amount of each component in Table 1 is parts by mass. Also, in Table 1, "equivalent ratio" represents "equivalent number of curing agent (equivalent number of active hydrogen) / equivalent number of epoxy resin (equivalent number of epoxy groups)".

[0070] The various evaluation results were summarized and shown in Table 2 below.

[0071]

Table 2

[0072] In Examples 1 to 5, the glass transition temperature measured by TMA was 60°C to 150°C, the coefficient of thermal expansion was 30 ppm / °C or less, the storage modulus at 25°C measured by DMA was 5 GPa to 10 GPa, and the storage modulus at 240°C was 0.10 GPa or less. In Comparative Example 1 where the storage modulus at 240°C was 0.40 GPa, although it was excellent in temperature cycle resistance, solder resist cracks occurred. It is considered that when the storage modulus at high temperature is high, the cured product of the underfill material cannot absorb the expansion of the solder at the reflow temperature, and stress is applied to the solder resist. In Comparative Example 2 where the coefficient of thermal expansion was 36 ppm / °C, although no solder resist cracks occurred, delamination was observed after 500 temperature cycles. It is considered that when the coefficient of thermal expansion is large, the amount of expansion and contraction of the cured product of the underfill material due to temperature cycles is large, and the underfill material and the chip interface are delaminated during contraction.

Claims

1. (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler; When cured, the thermal expansion coefficient at or below the glass transition temperature as measured by TMA (thermomechanical analysis) is 30 ppm / °C or less, the storage modulus at 240°C as measured by DMA (dynamic viscoelasticity measurement) is 0.10 GPa or less, and the storage modulus at 25°C as measured by DMA (dynamic viscoelasticity measurement) is 5 GPa to 9.5 GPa, the proportion of the epoxy resin containing an aromatic ring in the molecule in the total amount of the epoxy resin (A) is 65 mass% or more, the proportion of tri- or higher functional epoxy resins in the total amount of the epoxy resin (A) is 0 mass%; The (A) epoxy resin contains a bisphenol-type epoxy resin and a glycidyl ether-type epoxy resin obtained by reacting an alkyldiol with epichlorohydrin, The underfill material, wherein the (B) curing agent is an aromatic amine compound.

2. 2. The underfill material according to claim 1, wherein the cured product has a glass transition temperature of 60° C. to 150° C. as measured by TMA (thermomechanical analysis).

3. The underfill material according to claim 1 or 2, further comprising (D) a flexibilizing agent.

4. The underfill material according to any one of claims 1 to 3, further comprising (E) a surfactant.

5. The underfill material according to any one of claims 1 to 4, further comprising (F) an ion trapping agent.

6. The underfill material according to any one of claims 1 to 5, further comprising (G) a curing accelerator.

7. The underfill material according to any one of claims 1 to 6, further comprising (H) a coupling agent.

8. The underfill material according to any one of claims 1 to 7, further comprising (I) an antioxidant.

9. The underfill material according to any one of claims 1 to 8, further comprising (J) an organic solvent, the content of the organic solvent being 10 mass % or less.

10. A wiring board; an electronic component disposed on the wiring board and electrically connected to the wiring board via a connection portion; A cured product of the underfill material according to any one of claims 1 to 9, which seals at least a connection portion between the wiring board and the electronic component; An electronic component device comprising:

11. The electronic component device of claim 10 , wherein the connection portion is lead-free.

12. The electronic component device according to claim 10 or 11, wherein the connection portion contains copper.

13. A method for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion, comprising the steps of: a supplying step of supplying the underfill material according to any one of claims 1 to 9 to at least one of a surface of the electronic component facing the wiring board and a surface of the wiring board facing the electronic component; a connecting step of connecting the electronic component and the wiring board via the connecting portion and curing the underfill material.

14. A method for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion, comprising the steps of: a filling step of filling a gap between the connected electronic component and the wiring board with the underfill material according to any one of claims 1 to 9; and a curing step of curing the underfill material.

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