JP2020186397A - Underfill material, electronic component device, and method of manufacturing electronic component device - Google Patents

Abstract

To provide an underfill material which suppresses the occurrence of cracks of a solder resist during reflow and is excellent in temperature cycle resistance characteristics.SOLUTION: The underfill material contains (A) epoxy resins, (B) a curing agent, (C) an inorganic filler, and (I) an antioxidant. A cured product of the underfill material has a thermal expansion coefficient at a glass transition temperature or lower measured by TMA (thermomechanical analysis) of 30 ppm/°C or less and a storage modulus at 240°C measured by DMA (dynamic viscoelasticity measurement) of 0.10 GPa or less. The proportion of an epoxy resin having an aromatic ring in the molecule in the total amount of the epoxy resins (A) is 65 mass% or more. The proportion of a tri- or higher functional epoxy resin in the total amount of the epoxy resins (A) is 80 mass% or less. The curing agent (B) is an aromatic amine compound.SELECTED DRAWING: None

Description

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

Conventionally, in the field of element encapsulation of electronic component devices such as transistors, ICs (Integrated Circuits), and LSIs (Large Scale Integration), encapsulation materials containing resin are used for encapsulation from the viewpoints of productivity, cost, and the like. The method of doing is the mainstream. An epoxy resin composition is widely used as a sealing material. The reason for this is that the epoxy resin has a good balance of various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to insert products.

An underfill material is widely used as a sealing material in a bare chip mounted electronic component device such as COB (Chip on Board), COG (Chip on Glass), and TCP (Tape Carrier Package).
Further, in an electronic component device (flip chip) in which electronic components such as semiconductor elements are directly bump-connected on a wiring board whose substrate is ceramic, glass epoxy resin, glassimide resin, polyimide film, etc., the bump-connected electronic components An epoxy resin composition is used as an underfill material that fills a gap between the and the wiring board. Underfill materials play an important role in protecting electronic components from temperature and humidity and mechanical external forces.

Here, an epoxy resin composition for sealing having excellent moisture-resistant adhesive strength and low stress resistance, and an electronic component device having high reliability (moisture resistance, heat-impact resistance) including an element sealed by the composition are provided. Therefore, 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 this sealing. An electronic component device including an element sealed with an epoxy resin composition for use is disclosed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2001-270976

However, advances in semiconductor technology have been remarkable, and semiconductors and wiring boards have become larger and thinner. Therefore, in the flip-chip method of 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 bump, and the solder resist formed on the wiring board. Stress tends to concentrate on. When stress is concentrated on the solder resist, cracks may occur in the solder resist on the wiring board due to the expansion of 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, but if the amount of the inorganic filler is reduced too much, the coefficient of thermal expansion increases and in the temperature cycle test. Problems may occur due to expansion and contraction of the cured product of the underfill material.

As described above, with the progress of semiconductor technology, underfill materials are required to solve various problems.
The present invention has been made in view of such circumstances, and the underfill material which suppresses the occurrence of cracks in the solder resist during reflow and has excellent temperature-resistant cycle characteristics, and the reliability sealed thereby. An object of the present invention is to provide an expensive electronic component device and a method for manufacturing the same.

As a result of diligent studies to solve the above problems, the present inventors have determined that the composition of the underfill material includes (A) epoxy resin, (B) curing agent and (C) inorganic filler, and cures. The thermal expansion coefficient below the glass transition temperature measured by TMA (thermomechanical analysis) was set to 30 ppm / ° C or less, and the storage elastic modulus at 240 ° C measured by DMA (dynamic viscoelasticity measurement) was 0. It has been found that the above object can be achieved by setting the value to 10 GPa or less, and the present invention has been completed.

The present invention relates to the following.
<1> Contains (A) epoxy resin, (B) curing agent and (C) inorganic filler.
When a cured product is used, 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 Underfill material with 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 stored elastic modulus at 25 ° C. measured by DMA (Dynamic Viscoelasticity Measurement) when prepared as a cured product is 5 GPa to 10 GPa.
<4> The underfill material according to any one of <1> to <3>, which further contains (D) a flexible agent.
<5> The underfill material according to any one of <1> to <4>, which further contains (E) a surfactant.
<6> The underfill material according to any one of <1> to <5>, which further contains (F) an ion trapping agent.
<7> The underfill material according to any one of <1> to <6>, which further contains (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>, which further contains (J) an organic solvent and has a content of the organic solvent of 10% by mass or less.
<11> The underfill material according to any one of <1> to <10>, wherein the curing agent (B) is an aromatic amine compound.
<12> Wiring board and
An electronic component that is arranged on the wiring board and is electrically connected to the wiring board via a connection portion.
At least, the cured product of the underfill material according to any one of <1> to <11>, which seals the connection portion between the wiring board and the electronic component.
Electronic component device equipped with.
<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.
The under item according to any one of <1> to <11> on at least one surface of the electronic component on the side facing the wiring board and the surface of the wiring board facing the electronic component. The supply process for supplying fill materials and
A method for manufacturing an electronic component device, comprising 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.
A filling step of filling the 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.

According to the present invention, an underfill material that suppresses the occurrence of cracks in the solder resist during reflow and has excellent temperature-resistant cycle characteristics, and a highly reliable electronic component device sealed thereby and a method for manufacturing the same are provided. Provided.

In the present specification, the term "process" is included in this term not only as an independent process but also as long as the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. ..
In addition, the numerical range indicated by using "-" in the present specification indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present 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 another numerical range described stepwise. Good. Further, in the numerical range described in the present 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 the present specification, the content of each component in the composition is the total of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means the content rate of.
In the present specification, the particle size of each component in the composition is a mixture of the plurality of particles existing in the composition unless otherwise specified, when a plurality of particles corresponding to each component are present in the composition. Means a value for.
In the present specification, the term "layer" or "membrane" refers to a part of the region in addition to the case where the layer or the membrane is formed in the entire region when the region where the layer or the membrane exists is observed. The case where only is formed is also included.

<Underfill material>
The underfill material of the present disclosure contains (A) epoxy resin, (B) curing agent and (C) inorganic filler, and is equal to or lower than the glass transition temperature measured by TMA (thermomechanical analysis) when prepared as a cured product. The thermal expansion coefficient 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.

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

((A) Epoxy resin)
The epoxy resin of the 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 for an underfill material may be used. it can.
The type of epoxy resin used in the present disclosure is not particularly limited. Examples of the epoxy resin include glycidyl ether type epoxy resin and orthocresol novolac type epoxy obtained by reacting bisphenol A, bisphenol F, bisphenol AD, bisphenol S, hydrogenated bisphenol A, naphthalenediol, alkyldiol and the like with epichlorohydrin. Obtained by the reaction of epichlorohydrin with a novolak-type epoxy resin obtained by condensing or co-condensing phenols typified by a resin and aldehydes with a novolak-type epoxy resin obtained by epoxidizing a novolak resin, and polybasic acids such as phthalic acid and dimer acid. A glycidyl amine type epoxy resin obtained by reacting an amine compound such as aminophenol, diaminodiphenylmethane, or isocyanuric acid with epichlorohydrin, and an olefin bond obtained by oxidizing an olefin bond with a peracid such as peracetic acid. Examples thereof include linear aliphatic epoxy resins and alicyclic epoxy resins, which may be used alone or in combination of two or more.
Among them, a liquid bisphenol type epoxy resin, which is one kind of glycidyl ether type epoxy resin, is preferable from the viewpoint of fluidity, and a liquid glycidylamine type epoxy resin is preferable from the viewpoint of heat resistance, adhesiveness and fluidity.

The above two types of epoxy resins may be used alone or in combination, but the blending ratio is 20 mass in total with respect to the total amount of epoxy resin in order to exhibit its performance. % Or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more.
Further, the underfill material of the present disclosure may be used in combination with a solid epoxy resin as long as the effects of the present disclosure can be 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.

In order to reduce the coefficient of thermal expansion below the glass transition temperature measured by TMA (thermomechanical analysis) to 30 ppm / ° C or less when the underfill material is a cured product, an aromatic ring is included in the molecule, which accounts for the total amount of epoxy resin. The proportion of the epoxy resin contained is preferably 65% by mass or more, and more preferably 70% by mass or more.
In order to reduce the storage elastic modulus at 240 ° C. measured by DMA (Dynamic Mechanical Analysis) to 0.10 GPa or less when the underfill material is a cured product, a trifunctional or higher functional epoxy resin accounts for the total amount of epoxy resin. The ratio of the above is preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 60% by mass or less.

The liquid epoxy resin means a liquid epoxy resin at room temperature (25 ° C.). Specifically, it means that the viscosity measured by the 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, and the number of rotations is sampled with reference to the following. After setting according to the expected viscosity of, the value 1 minute after the start of measurement is used as the measured value.
(1) When the assumed viscosity is 100 Pa · s to 1000 Pa · s: Rotation speed 0.5 rpm (2) When the expected viscosity is less than 100 Pa · s: Rotation speed 5 rpm The epoxy resin means that it is a solid epoxy resin at room temperature (25 ° C.).

The purity of the epoxy resin, especially the amount of hydrolyzable chlorine, is preferably small because it is related to the corrosion of the aluminum wiring on the element such as the IC, and in order to obtain an underfill material having excellent moisture resistance, the hydrolyzability of the epoxy resin is obtained. The amount of chlorine is preferably 500 ppm or less. Here, the amount of hydrolyzable chlorine is measured by dissolving 1 g of the sample epoxy resin in 30 ml of dioxane, adding 5 ml of a 1N-KOH methanol solution, refluxing for 30 minutes, and then measuring the value obtained by potentiometric titration. is there.

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 90 g / eq to 250 g / eq from the viewpoint of viscosity adjustment. Is even more preferable.
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 a tetraethylammonium bromide acetic acid solution, and then potentiometric titration with an acetic acid perchlorate standard solution. An indicator may be used for this titration.

The content of the epoxy resin is not particularly limited, and for example, the proportion of the underfill material in the solid content is preferably 10% by mass to 50% by mass, and is 15% by mass to 45% by mass. Is more preferable, and 20% by mass to 40% by mass is further preferable.
In the present disclosure, the "solid content" of the underfill material means the remaining components obtained by removing volatile components such as organic solvents from the underfill material.

((B) Hardener)
The curing agent for component (B) used in the present disclosure is not particularly limited.
Examples of the curing agent include amines having an aromatic ring (aromatic amine compounds): 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 can be mentioned.
These aromatic amine compounds are commercially available products such as Epicure-W, Epicure-Z (trade name manufactured by Mitsubishi Chemical Corporation), Kayahard AA, Kayahard AB, and Kayahard AS (manufactured by Nippon Steel & Sumikin Co., Ltd.). Product name), Totoamine HM-205 (Product name manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Adeka Hardener EH-101 (Product name manufactured by ADEKA Corporation), Epomic Q-640, Epomic Q-643 (Product name manufactured by Mitsui Chemicals Co., Ltd.) Name), DETDA80 (trade name manufactured by London) and the like are available, and these may be used alone or in combination of two or more.

When an aromatic amine compound is used as the curing agent, the aromatic amine compounds include, for example, 3,3'-diethyl-4,4'-diaminodiphenylmethane and diethyltoluenediamine from the viewpoint of storage stability of the underfill material. Is preferable. Examples of the diethyltoluenediamine include 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine. When an aromatic amine compound is used as the curing agent, the curing agent contains 50% by mass or more of 3,3'-diethyl-4,4'-diaminodiphenylmethane or 3,5-diethyltoluene-2,4-diamine. Is preferable.

Examples of the curing agent are acid anhydrides, phthalic anhydride, maleic anhydride, methylhymic acid anhydride, hymic acid anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and chlorendic anhydride. , Methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride maleic anhydride, benzophenonetetracarboxylic anhydride, trimellitic anhydride, pyrochloride Examples thereof include merit acid, methylnadic hydride anhydride, trialkyltetrahydrophthalic anhydride obtained by the deal alder reaction from maleic anhydride and a diene compound, and various acid anhydrides such as dodecenyl succinic anhydride. These may be used alone or in combination of two or more.

When an acid anhydride is used as the curing agent, for example, tetrahydrophthalic anhydride and hexahydrophthalic anhydride are preferable as the acid anhydride from the viewpoint of reducing the viscosity of the underfill material. When an acid anhydride is used as the curing agent, the curing agent preferably contains 50% by mass or more of tetrahydrophthalic anhydride or hexahydrophthalic anhydride.

Further, as the underfill material, in addition to the aromatic amine compound and the acid anhydride, a curing agent generally used in the underfill material such as a phenolic curing agent can be used as long as the effects of the present disclosure can be achieved. Can be used together.
As the curing agent, an aromatic amine compound having good moisture resistance and reliability is preferable because the cured product is not easily hydrolyzed.

The equivalent ratio between the equivalent number of the epoxy resin contained in the underfill material and the equivalent number of the curing agent (equivalent number of the curing agent / equivalent number of the epoxy resin) is preferably 0.7 to 1.3, and is 0. It is more preferably .8 to 1.2, and even more preferably 0.9 to 1.1. When the ratio is 0.7 or more, the curing agent is not insufficient, the epoxy resin that does not participate in the reaction is reduced, and the reliability tends to be less likely to be lowered. On the other hand, when the ratio is 1.3 or less, the glass transition temperature does not become too high because the excess curing agent decreases, and the elastic modulus of the cured product at a high temperature does not become too high. Warp tends to be less likely to occur.

((C) Inorganic filler)
Examples of the inorganic filler of the component (C) used in the present disclosure include spherical silica, silica such as crystalline silica, calcium carbonate, clay, alumina, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, and the like. Examples thereof include powders of aluminum nitride, berylia, zirconia, zircone, fosterite, steatite, spinel, mulite, titania and the like, or spherical beads and glass fibers thereof.
Further, examples of the inorganic filler 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. Of these, spherical silica is more preferable from the viewpoint of fluidity and permeability of the underfill material into the fine gaps.

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. When the average particle size is 0.05 μm or more, the dispersibility in the liquid resin is improved, the viscosity is less likely to be increased, and the flow characteristics of the underfill material tend to be improved. When the average particle size is 20 μm or less, sedimentation tends to occur easily, and the permeability and fluidity of the underfill material into the fine gaps are improved, so that voids and the underfill material are less likely to be unfilled. is there.
Here, the average particle size is a particle size corresponding to a volume of 50% when the cumulative frequency distribution curve by the particle size is obtained with the total volume of the particles as 100%, and the particle size distribution is measured by the laser diffraction scattering method. It can be measured with a device or the like.

The content of the inorganic filler is preferably in the range of 20% by mass to 90% by mass, more preferably 30% by mass to 85% by mass, still more preferably, as a ratio to the solid content of the underfill material. It is 40% by mass to 80% by mass. If the content is 20% by mass or more, the coefficient of thermal expansion is unlikely to decrease, and the temperature cycle resistance of the cured product of the underfill material tends to be more excellent. If it is 90% by mass or less, the viscosity of the underfill material tends to be better. Is less likely to increase and tends to be less likely to cause a decrease in fluidity, permeability and dispensability.

((D) Flexible agent)
Various flexible agents can be added to the underfill material of the present disclosure from the viewpoints of improving thermal shock resistance and reducing stress on electronic components such as semiconductor elements.
The flexible agent is not particularly limited, but rubber particles are preferable. Examples of the rubber particles include rubber particles of silicone rubber and rubber particles of synthetic rubber other than silicone rubber (hereinafter, may be simply referred to as "synthetic rubber").
Examples of rubber particles of synthetic rubber include rubber particles such as styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), butadiene rubber (BR), urethane rubber (UR), and acrylic rubber (AR). .. Among them, acrylic rubber rubber particles are preferable from the viewpoint of heat resistance and moisture resistance, and a core-shell type acrylic polymer, that is, a core-shell type acrylic rubber particles are more preferable.

To give an example of the rubber particles of silicone rubber, the surface of the silicone rubber particles obtained by cross-linking polyorganosiloxanes such as linear polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane, and the surface of the silicone rubber particles are coated with silicone resin. Core-shell polymer particles having a core of solid silicone particles obtained by emulsion polymerization and a shell of a polymer such as acrylic resin, and spherical solid silicone rubber particles whose surface is modified with an epoxy group. Examples include silicone particles. The shape of these silicone rubber particles can be used regardless of whether they are amorphous or spherical. In order to keep the viscosity of the underfill material related to moldability low, it is preferable to use a spherical material. Commercially available products of these silicone rubber particles are available from Toray Dow Corning Co., Ltd., Shin-Etsu Chemical Co., Ltd., and the like.

The average particle size of these flexible agents is preferably small in order to uniformly modify the underfill material, and the average particle size is preferably in the range of 0.05 μm to 10 μm, and 0.1 μm to 5 μm. It is more preferable that the range is. 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, and further, penetration into the fine gaps as the underfill material. The property and fluidity are improved, and it tends to be difficult to cause unfilling of voids and underfill materials.

The content of the flexible agent is preferably set in the range of 1% by mass to 30% by mass, and more preferably 2% by mass to 20% by mass with respect to the entire epoxy resin. If the content of the flexible agent is 1% by mass or more, the effect of reducing stress tends to improve, and if it is 30% by mass or less, the viscosity of the underfill material is unlikely to increase, and moldability (flow characteristics, etc.) ) Tends to be excellent.

((E) Surfactant)
Various surfactants can be added to the underfill material of the present disclosure from the viewpoint of reducing the generation of voids during molding and improving the adhesive force by improving the wettability to various adherends.
The surfactant is not particularly limited, but a nonionic surfactant is preferable, and a polyoxyalkylene alkyl ether-based surfactant such as a polyoxyethylene alkyl ether-based surfactant and a sorbitan fatty acid ester-based surfactant are used. , Polyoxyethylene sorbitan fatty acid ester-based surfactant, polyoxyethylene sorbitol fatty acid ester-based surfactant, glycerin fatty acid ester-based surfactant, polyoxyethylene fatty acid ester-based surfactant, polyoxyethylene alkylamine-based surfactant , Alkyl alkanolamide-based surfactants, polyether-modified silicone-based surfactants, aralkyl-modified silicone-based surfactants, polyester-modified silicone-based surfactants, polyacrylic-based surfactants, and other surfactants. May be used alone or in combination of two or more. Commercially available products of these surfactants are available from Big Chemie Japan Co., Ltd., Kao Corporation, and the like.

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 epoxy resin and an organosiloxane having a functional group that reacts with an epoxy group. The silicone-modified epoxy resin is preferably liquid at room temperature (25 ° C.). Here, to give an example of an organosiloxane having a functional group that reacts with an epoxy group, dimethylsiloxane, diphenylsiloxane, methylphenyl having at least one amino group, carboxy group, hydroxyl group, phenolic hydroxyl group, mercapto group, etc. in one molecule. Examples include siloxane. The weight average molecular weight of the organosiloxane is preferably in the range of 500 to 5000. When the weight average molecular weight of the organosiloxane is 500 or more, the compatibility with the epoxy resin or the like is not excessively improved, and the effect as an additive tends to be easily exhibited. If the weight average molecular weight of the organosiloxane is 5000 or less, it is unlikely to be incompatible with the epoxy resin or the like, so that the silicone-modified epoxy resin is unlikely to separate or exude from the underfill material when the underfill material is cured, and is adhered. It tends to be less prone to problems that impair sex or appearance.
The weight average molecular weight of the organosiloxane is determined by converting the molecular weight distribution measured by GPC (gel permeation chromatography) using a standard polystyrene calibration curve.

The epoxy resin for obtaining the silicone-modified epoxy resin is not particularly limited as long as it is compatible with the resin system of the underfill material, and an epoxy resin generally used for the underfill material can be used. Typical epoxy resins include glycidyl ether type epoxy resin and orthocresol novolac type epoxy resin obtained by reacting bisphenol A, bisphenol F, bisphenol AD, bisphenol S, naphthalenediol, hydrogenated bisphenol A and the like with epichlorohydrin. A novolak-type epoxy resin obtained by condensing or co-condensing a novolak resin obtained by condensing or co-condensing the phenols and aldehydes, and a glycidyl ester obtained by reacting a polybasic acid such as phthalic acid or dimer acid with epichlorohydrin. A glycidylamine type epoxy resin obtained by reacting an amine compound such as a type epoxy resin, diaminodiphenylmethane or isocyanuric acid with epichlorohydrin, or a linear aliphatic epoxy obtained by oxidizing an olefin bond with a peracid such as peracetic acid. Examples thereof include resins and alicyclic epoxy resins, and these may be used alone or in combination of two or more, but those liquid at room temperature (25 ° C.) are preferable.

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 entire epoxy resin. If the content of the surfactant is 0.01% by mass or more, a sufficient addition effect tends to be easily obtained, and if it is 1.5% by mass or less, the surface of the cured product is cured when the underfill material is cured. Since the surface active agent is less likely to seep out, the adhesive strength tends to be less likely to decrease.

((F) Ion trap agent)
The underfill material of the present disclosure has a viewpoint of improving migration resistance, moisture resistance and high temperature standing characteristics of an ion trap agent as necessary within a range that does not impair the filling property and fluidity when applied to electronic component devices. Can be blended from.
The ion trapping agent is not particularly limited, and conventionally known ones can be used, and hydrotalcite represented by the following composition formula (I) or bismuth hydrous oxide represented by the following composition formula (II) can be used. preferable.

Mg _1-X Al _X (OH) ₂ (CO ₃ ) _{X / 2}・ mH ₂ O (I)
(In the composition formula (I), 0 <X ≦ 0.5, and m represents a positive number.)
BiO _a (OH) _b (NO ₃ ) _c (II)
(In the composition formula (II), a, b and c are 0.9 ≦ a ≦ 1.1, 0.6 ≦ b ≦ 0.8 and 0.2 ≦ c ≦ 0.4, respectively.)

The content of the ion trap agent is preferably 0.1% by mass to 3.0% by mass, and more preferably 0.3% by mass to 1.5% by mass with respect to the entire 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 composition formula (I) is available as a commercial product under the trade name DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd. Further, the compound represented by the above composition formula (II) is available as a commercially available product as IXE-500 (trade name manufactured by Toagosei Co., Ltd.).
Further, if necessary, another anion exchanger can be blended as an ion trapping agent. The anion exchanger is not particularly limited, and conventionally known ones can be used. Examples of the ion trapping agent include hydrous oxides such as magnesium, aluminum, titanium, zirconium, and antimony, and these can be used alone or in combination of two or more.

((G) Curing accelerator)
Various curing accelerators can be added to the underfill material of the present disclosure 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 promotes the reaction between the epoxy resin and the curing agent, and conventionally known ones can be used. As the curing accelerator, 1,8-diaza-bicyclo (5.4.0) undecene-7, 1,5-diaza-bicyclo (4.3.0) nonene, 5,6-dibutylamino-1,8 -Diaza-bicyclo (5.4.0) Undecene-7 and other cycloamidin compounds, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol and other tertiary amine compounds, 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- Imidazole compounds such as heptadecylimidazole, trialkylphosphine such as tributylphosphine, dialkylarylphosphine such as dimethylphenylphosphine, alkyldiarylphosphine such as methyldiphenylphosphine, triphenylphosphine, triarylphosphine such as alkyl group substituted triphenylphosphine, etc. Organic phosphines, these compounds include maleic anhydride, 1,4-benzoquinone, 2,5-torquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy. Addition of quinone compounds such as -5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, and compounds having a π bond such as diazophenylmethane and phenol resin. Examples thereof include compounds having intramolecular polarization, derivatives thereof, and phenylborone salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholintetraphenylborate, which are used alone. It may be used or a combination of two or more types may be used. Further, as a curing accelerator having potential, core-shell particles formed by coating a shell of a solid epoxy compound at room temperature (25 ° C) with a compound having an amino group solid at room temperature (25 ° C) as a core. As commercial products, Amicure (trade name manufactured by Ajinomoto Co., Ltd.) and Novacure (product manufactured by Asahi Kasei Co., Ltd.) in which microencapsulated amines are dispersed in bisphenol A type epoxy resin and bisphenol F type epoxy resin to impart potential. First name) etc. can be used.

Of these, imidazole derivatives are preferable from the viewpoint of balancing curing promoting action and reliability, and 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-, which are imidazole derivatives having a phenyl group and a hydroxyl group as substituents, are preferable. Novacure (trade name manufactured by Asahi Kasei Co., Ltd.), which imparts potential by dispersing methyl-5-hydroxymethylimidazole and microencapsulated amine in bisphenol A type epoxy resin and bisphenol F type epoxy resin, is more preferable, and 2- Phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole are more preferred.

The content of the curing accelerator is not particularly limited as long as the curing promoting effect is achieved, but is preferably in the range of 0.2% by mass to 5% by mass with respect to the mass of the total epoxy resin. The range of 0.5% by mass to 3% by mass is more preferable. When the content of the curing accelerator is 0.2% by mass or more, the effect of adding the curing accelerator is sufficiently exhibited, and as a result, the generation of voids when curing the underfill material can be suppressed, and at the same time, it becomes possible to suppress the generation of voids. The warp reduction effect tends to be sufficient, and if it is 5% by mass or less, the storage stability tends to be excellent.

((H) Coupling agent)
The underfill material of the present disclosure may be blended with an epoxy resin and an inorganic filler, or a coupling agent for the purpose of strengthening the adhesion between the epoxy resin and the constituent members of the electronic component device. The coupling agent is not particularly limited, and conventionally known ones can be used. Various coupling agents include silane compounds having at least one selected from the group consisting of primary amino groups, secondary amino groups and tertiary amino groups, epoxysilanes, mercaptosilanes, alkylsilanes, ureidosilanes, vinylsilanes and the like. Examples thereof include silane compounds, titanium compounds, aluminum chelate compounds, and zirconium compounds.
Examples of these are vinyl trichlorosilane, vinyl triethoxysilane, vinyl tris (β-methoxyethoxy) silane, γ-methacryloxypropyl trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-gly. Sidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyl Triethoxysilane, 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) anilinopropyl Trimethoxysilane, 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, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane , Silane coupling agents such as γ-mercaptopropylmethyldimethoxysilane, isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) tita Nate, tetraoctylbis (ditridecylphosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecylphosphite) titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyro) Phosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyldiacrylic titanate, isopropyltri (dioctylphosphate) titanate, isopropyltricylphenyl titanate, tetraisopropylbis (phosphate) Examples thereof include titanate-based coupling agents such as dioctyl phosphite) titanate, and these may be used alone or in combination of two or more.

The content of the coupling agent is preferably 0.1% by mass to 10% by mass, more preferably 1% by mass to 5% by mass, based on the entire epoxy resin.

((I) Antioxidant)
An antioxidant can be added to the underfill material of the present disclosure. As the antioxidant, conventionally known ones can be used.
Examples of the phenol compound antioxidant include 2,6-di-t-butyl-4-methylphenol and n-octadecyl-3- (3,5) as compounds having at least one alkyl group at the ortho position of the phenol nucleus. -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-methylphenylacrylate, 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-4hydroxybenzyl) 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.
Examples of the organosulfur compound-based antioxidant include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, and pentaerythrityl. Tetrax (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, etc. Can be mentioned.
Examples of the amine compound antioxidant include N, N'-diallyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, octylated diphenylamine, and 2,4-bis- (n-). Octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine and the like can be mentioned.
Among the amine compound-based antioxidants, as dicyclohexylamine, trade name D-CHA-T manufactured by Shin Nihon Rika Co., Ltd. is available as a commercially available product, and its derivatives include dicyclohexylamine ammonium nitrite, N, N. Examples thereof include −di (3-methyl-cyclohexylamine) amine, N, N-di (2-methoxy-cyclohexylamine) amine, N, N-di (4-bromo-cyclohexylamine) amine and the like.
Examples of phosphorus compound antioxidants include trisnonylphenylphosphite, triphenylphosphite, bis [3,5-di-t-butyl-4-hydroxybenzyl (ethoxy) phosphinate] calcium, and tris (2,4-di). -T-Butylphenyl) phosphite, 2-[[2,4,8,10-tetrakis (1,1-dimethylether) dibenzo [d, f] [1,3,2] dioxaphosfepin- 6-Il] Oxy] -N, N-bis [2-{[2,4,8,10-tetrakis (1,1 dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphospene Pin-6-yl] oxy} -ethyl] ethaneamine, 6- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-t-butyldibenz Examples thereof include [d, f] [1,3,2] dioxaphosphepine, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate and the like.
The antioxidants may be used alone or in combination of two or more. As a specific example of the antioxidant, there are compounds containing at least one of a phosphorus atom, a sulfur atom and an amine in the same molecule in addition to the phenolic hydroxyl group, but these compounds may be mentioned in duplicate. is there.

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 entire epoxy resin.

((J) Organic solvent)
An organic solvent can be added to the underfill material of the present disclosure as needed to reduce the viscosity. In particular, when a solid epoxy resin and a curing agent are used, it is preferable to add an organic solvent in order to obtain a liquid underfill material.
The organic solvent is not particularly limited, and alcohol-based solvents such as methyl alcohol, ethyl alcohol, propyl alcohol and butyl alcohol, ketone solvents such as acetone and methyl ethyl ketone, ethylene glycol ethyl ether, ethylene glycol methyl ether and ethylene glycol butyl ether, Glycol ether solvents such as 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, dimethylacetamide and dimethyl Examples thereof include amide solvents such as formamide and aromatic solvents such as toluene and xylene, and these may be used alone or in combination of two or more. Among these, an organic solvent having a boiling point of 170 ° C. or higher is preferable from the viewpoint of avoiding the formation of bubbles due to rapid volatilization when the underfill material is cured.

The amount of the organic solvent to be blended is not particularly limited as long as it does not form bubbles when the underfill material is cured, but it is preferably 10% by mass or less, preferably 5% by mass or less, based on the entire underfill material. More preferably.

(Other additives)
Other additives such as dyes, colorants such as carbon black, diluents, leveling agents, and antifoaming agents can be added to the underfill material of the present disclosure, if necessary.

(Physical properties of underfill material)
The viscosity of the underfill material is not particularly limited. Above all, from the viewpoint 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 rotations / minute).

Further, as an index of ease of filling when filling an underfill material in a narrow gap of several tens of μm to several hundreds of μm in the vicinity of 100 ° C to 120 ° C, the viscosity at 110 ° C is 0.3 Pa · s or less. It is preferably 0.2 Pa · s or less, and more preferably 0.2 Pa · s or less. The viscosity of the underfill material at 110 ° C. is measured by a rheometer AR2000 (manufactured by TA Instrument, aluminum cone 40 mm, shear rate 32.5 / sec).

The underfill material has a fluctuation index [, which is the ratio of the viscosity at a rotation speed of 1.5 rotations / minute and the viscosity at a rotation speed of 10 rotations / minute measured at 25 ° C. using an E-type viscometer. (Viscosity at 1.5 rpm) / (Viscosity at 10 rpm)] is preferably 0.3 to 1.1, more preferably 0.4 to 1.0. When the fluctuation index is in the above range, the fillet forming property is further improved. The viscosity and fluctuation index of the underfill material can be set in a desired range by appropriately selecting the composition of the epoxy resin, the content of the inorganic filler, and the like.

(Physical properties of cured product)
In the present disclosure, the cured product of the underfill material used for the measurement of the glass transition temperature and the coefficient of thermal expansion by TMA and the measurement of the storage elastic modulus by DMA was obtained by heating the underfill material at 150 ° C. for 2 hours. It is a thing.

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 lower, preferably 28 ppm / ° C or lower, and 26 ppm / ° C or lower. It is more preferable to have. When 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 resistance cycle characteristics are improved. The coefficient of thermal expansion below the glass transition temperature measured by TMA (thermomechanical analysis) may be 15 ppm / ° C. or higher.
The storage elastic 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, and 0.08 GPa or less. It is more preferable that the value is 0.07 GPa or less. When the storage elastic 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 resistance cycle characteristics are improved. The storage elastic 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 further preferably 70 ° C. to 130 ° C. or lower. .. When the glass transition temperature is 60 ° C. or higher, the protection of bumps at high temperatures is high and disconnection tends to be less likely to occur. Further, when the glass transition temperature is 150 ° C. or lower, the warp at room temperature (25 ° C.) tends to be less likely to increase.
The storage elastic 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, and more preferably 5.5 GPa to 9.5 GPa. It is preferably 6 GPa to 9 GPa, and more preferably 6 GPa to 9 GPa. When the storage elastic modulus at 25 ° C. is 5 GPa or more, the bump protection at high temperature is high and disconnection tends to be less likely to occur. Further, when the elastic modulus at 25 ° C. is 10 GPa or less, the warp at room temperature (25 ° C.) tends to be less likely to increase.

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

(Manufacturing of underfill material)
The underfill material of the present disclosure can be produced by any method as long as the above-mentioned various components can be uniformly dispersed and mixed. As a general method, an underfill material is obtained by weighing the components having a predetermined mixing ratio, mixing them using a raker, a mixing roll, a planetary mixer, etc., kneading them, and defoaming them if necessary. Can be done.

<Electronic component equipment>
The electronic component device of the present disclosure includes a wiring board, an electronic component arranged on the wiring board and electrically connected to the wiring board via a connection portion, and at least the wiring board and the electronic component. A cured product of the underfill material of the present disclosure that seals a connection portion is provided. 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. Since the electronic component is sealed with the underfill material, the electronic component device of the present disclosure is excellent in reliability such as temperature cycle resistance.
The connection portion in the electronic component device is preferably configured to contain copper in order to ensure high conductivity.

Electronic component devices include lead frames, pre-wired tape carriers, rigid wiring boards, flexible wiring boards, glass, silicon wafers and other wiring boards, semiconductor chips, transistors, diodes, thyristors and other active elements, capacitors, and resistors. Examples thereof include electronic component devices obtained by mounting electronic components such as passive elements such as resistance arrays, coils, and switches, 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 by bump connection to a rigid wiring board, a flexible wiring board, or wiring formed on glass 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).

The underfill material of the present disclosure is suitable as an underfill material for flip chips having excellent reliability. In the field of flip chips to which the underfill material of the present disclosure is particularly preferably applied, the material of the bump connecting the wiring board and the semiconductor element is not the conventional lead-containing solder, but lead-free such as Sn-Ag-Cu. This is the field of flip-chip semiconductor components using solder.
The connection portion in the electronic component device may have a lead-free configuration. The underfill material of the present disclosure can maintain good reliability even for flip chips in which bump connections are made using lead-free solder, which is physically fragile as compared with conventional lead solder. Further, it is suitable for an element having a semiconductor element size of 2 mm or more on the longer side, and a flip chip connection in which the distance between the wiring substrate constituting the electronic component device and the bump connection surface of the semiconductor element is 200 μm or less. It is possible to provide a semiconductor device which exhibits good fluidity and filling property and is excellent in reliability such as moisture resistance and thermal shock resistance. Further, in recent years, as the speed of semiconductor elements has increased, an interlayer insulating film having a low dielectric constant may be formed on the semiconductor element, and these low dielectric constant insulators have weak mechanical strength and are broken by external stress. Is likely to occur. This tendency becomes more remarkable as the size of the semiconductor element becomes larger, and it is required to reduce the stress by the underfill material. The underfill material of the present disclosure is also excellent for a flip-chip semiconductor device equipped with a semiconductor element having an interlayer insulating film having a semiconductor element size of 2 mm or more on the longer side and a dielectric constant of 3.0 or less. Can provide reliability.

<Manufacturing method of electronic component equipment>
Examples of the method for sealing the electronic component device using the underfill material of the present disclosure include a dispensing method, a casting method, a printing method and the like.
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, in the method of manufacturing the first electronic component device of the present disclosure, at least one surface of the electronic component on the side facing the wiring board and the surface of the wiring board facing the electronic component are under the present disclosure. It has a supply step of supplying a fill material and a connection step of connecting an electronic component and a wiring board via a connecting portion and curing the underfill material. In the first method for manufacturing an electronic component device, the underfill material of the present disclosure can be used as a pre-supply type underfill material.
Further, the second method of manufacturing the 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. Have. In the second method for manufacturing an electronic component device, the underfill material of the present disclosure can be used as a post-supply type underfill material.

Next, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

The methods for evaluating various properties and reliability of the underfill material performed in the examples are summarized below.

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 + 15 μm lead-free solder, the bump pitch is 150 μm, and the number of bumps is 25921. As the wiring board, E-705 (trade name manufactured by Hitachi Chemical Co., Ltd.) having a length of 55 mm, a width of 55 mm, and a thickness of 1 mm was used. The solder resist was AUS703 (trade name manufactured by Taiyo Ink Mfg. Co., Ltd.) having a thickness of 15 μm.

In the electronic component device, the underfill material is filled in 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 by a dispense method, and the electronic component device is cured at 150 ° C. for 2 hours. I made it. In addition, the curing conditions of various test pieces were the same.

(1) Glass transition temperature TMA (thermomechanical analysis) was performed on the cured product of the underfill material using TA4000SA manufactured by TA Instruments, and the intersection of the tangents before and after the inflection point of the obtained chart was the glass transition temperature. And said. The heating rate was 5 ° C./min.
(2) Coefficient of thermal expansion TMA (thermomechanical analysis) was performed on the cured product of the underfill material using TA4000SA manufactured by TA Instruments, and the slope connecting the two points of 10 ° C and 30 ° C on the obtained chart. Was divided by the length of the test piece to obtain the coefficient of thermal expansion. The heating rate was 5 ° C./min.
(3) Storage elastic modulus The cured product of the underfill material was subjected to DMA (Dynamic Viscoelasticity Measurement) using Q800 manufactured by TA Instruments Co., Ltd., and the storage elastic 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 A scanning electron microscope manufactured by Hitachi High-Technologies Co., Ltd. (device name) is cut by cutting an electronic component device that has undergone a thermal history of 1 minute or more three times at a temperature of 240 ° C or higher so that the bump portion can be observed. The presence or absence of solder resist cracks was observed in SU1510).
(5) Temperature cycle An ultrasonic microscope (device name IS-350) manufactured by Insight Co., Ltd. is used as an electronic component device after performing a temperature cycle test with a temperature cycle of -55 ° C / 10 minutes and 125 ° C / 10 minutes as one cycle. It was observed using 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. Further, <500 indicates that peeling occurred at the end of 500 cycles.

(Examples 1 to 5 and Comparative Examples 1 and 2)
As the epoxy resin of the component (A), a liquid diepoxy resin (epoxy resin 1) having an epoxy equivalent of 160 g / eq obtained by epoxidizing bisphenol F and a trifunctional epoxy equivalent of 95 g / eq obtained by epoxyizing aminophenol. A liquid epoxy resin (epoxy resin 2), a diepoxy resin (epoxy resin 3) having an epoxy equivalent of 140 g / eq obtained by epoxidizing naphthalene diol, and a liquid die epoxy resin having an epoxy equivalent of 128 g / eq obtained by epoxidizing an alkyl diol. (Epoxy resin 4) was used.
As the curing agent for the component (B), 3,5-diethyltoluene-2,4-diamine having an active hydrogen equivalent of 45 g / eq was used.
Spherical silica having an average particle size of 1 μm was used as the inorganic filler for the component (C).
As the flexible agent for the component (D), spherical silicone particles having an average particle size of 2 μm in which the surface of the dimethyl solid silicone rubber particles was modified with an epoxy group were used.
As the surfactant of the component (E), a silicone-modified epoxy resin which is a reaction product of an organosiloxane having a functional group reacting with an epoxy group having a weight average molecular weight of 1000 and a bisphenol F type epoxy resin was used.
A bismuth-based ion trapping agent (trade name IXE-500 manufactured by Toagosei Co., Ltd.) was used as the ion trapping agent for the component (F).
2-Phenyl-4-methyl-5-hydroxymethylimidazole was used as a curing accelerator for the component (G).
Gamma-glycidoxypropyltrimethoxysilane was used as the coupling agent for the component (H).
As the antioxidant of the 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.
Γ-Butyrolactone was used as the organic solvent for the component (J).
Carbon black (trade name MA-100 manufactured by Mitsubishi Chemical Corporation) was used as the colorant.
Each of the above components is blended in the composition shown in Table 1 below, kneaded and dispersed using a three-roll roll and a squid that can reduce the pressure to prepare underfill materials of Examples 1 to 5 and Comparative Examples 1 and 2. did.

The unit of the blending amount of each component in Table 1 is a mass part. In addition, "equivalent ratio" in Table 1 represents "equivalent number of curing agent (equivalent number of active hydrogen) / equivalent number of epoxy resin (equivalent number of epoxy group)".

The results of various evaluations are summarized in Table 2 below.

In Examples 1 to 5, the glass transition temperature measured by TMA is 60 ° C. to 150 ° C., the coefficient of thermal expansion is 30 ppm / ° C. or less, the storage elastic modulus at 25 ° C. measured by DMA is 5 GPa to 10 GPa, and 240 ° C. The storage elastic modulus was 0.10 GPa or less.
In Comparative Example 1 having a storage elastic modulus of 0.40 GPa at 240 ° C., although the temperature cycle resistance was excellent, solder resist cracks were generated. It is probable that if the storage elastic 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 having a coefficient of thermal expansion of 36 ppm / ° C., although solder resist cracks did not develop, peeling was observed at a temperature cycle of 500 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 the temperature cycle is large, and the chip interface and the underfill material are peeled off during the contraction.

Claims (14)

Contains (A) epoxy resin, (B) curing agent, (C) inorganic filler and (I) antioxidant.
When a cured product is used, 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 It is 0.10 GPa or less,
The proportion of the epoxy resin containing an aromatic ring in the molecule in the total amount of the epoxy resin (A) is 65% by mass or more.
The ratio of the trifunctional or higher functional epoxy resin to the total amount of the (A) epoxy resin is 80% by mass or less.
An underfill material in which the curing agent (B) is an aromatic amine compound. The underfill material according to claim 1, wherein the glass transition temperature measured by TMA (thermomechanical analysis) when made into a cured product is 60 ° C. to 150 ° C. The underfill material according to claim 1 or 2, wherein the stored elastic modulus at 25 ° C. measured by DMA (dynamic viscoelasticity measurement) when made into a cured product is 5 GPa to 10 GPa. The underfill material according to any one of claims 1 to 3, further comprising (D) a flexible agent. The underfill material according to any one of claims 1 to 4, further containing (E) a surfactant. The underfill material according to any one of claims 1 to 5, further comprising (F) an ion trapping agent. The underfill material according to any one of claims 1 to 6, further comprising (G) a curing accelerator. The underfill material according to any one of claims 1 to 7, further comprising (H) a coupling agent. The underfill material according to any one of claims 1 to 8, further comprising (J) an organic solvent and having a content of the organic solvent of 10% by mass or less. Wiring board and
An electronic component that is arranged on the wiring board and is electrically connected to the wiring board via a connection portion.
At least, the cured product of the underfill material according to any one of claims 1 to 9, which seals the connection portion between the wiring board and the electronic component.
Electronic component device equipped with. The electronic component device according to claim 10, wherein the connection portion does not contain lead. The electronic component device according to claim 10 or 11, wherein the connection portion contains copper. A method for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion.
The undercoat according to any one of claims 1 to 9, wherein at least one surface of the electronic component on the side facing the wiring board and the surface of the wiring board facing the electronic component The supply process for supplying fill materials and
A method for manufacturing an electronic component device, comprising a connection step of connecting the electronic component and the wiring board via the connection portion and curing the underfill material. A method for manufacturing an electronic component device in which an electronic component and a wiring board are electrically connected via a connection portion.
A filling step of filling the gap between the connected electronic component and the wiring board with the underfill material according to any one of claims 1 to 9.
A method for manufacturing an electronic component device, comprising a curing step of curing the underfill material.