TWI588235B - Anisotropic conductive film, connecting method, and joined structure - Google Patents

Description

Anisotropic conductive film, connection method thereof and joint body thereof

The present invention relates to an anisotropic conductive film, a method of joining the same, and a bonded body thereof.

Conventionally, a strip-shaped bonding material (for example, an anisotropic conductive film (ACF)) which applies a thermosetting resin in which conductive particles are dispersed to a release film is used as a connection between an electronic component and a substrate. means.

For example, the anisotropic conductive film is formed by a terminal of a flexible printed circuit (FPC) or an IC (Integrated Circuit) chip, and is formed on a liquid crystal panel (LCD, Liquid Crystal Display). The case where the electrodes are connected to the glass substrate is used for the case where the various terminals are connected to each other and electrically connected.

In recent years, there has been a problem that the substrate is likely to be warped after the substrate is connected to the electronic component because the substrate to be connected by the anisotropic conductive film is reduced in thickness and the use area of the substrate is increased. If the substrate is warped, for example, there is a case where a color unevenness is generated in the LCD panel.

Therefore, in order to reduce the warpage of the substrate, a method of alleviating the stress applied to the substrate has been proposed.

For example, an anisotropic conductive film which is an anisotropic conductive film obtained from a thermosetting acrylic resin composition containing at least (A) a heat hardener and (B) a heat hardening has been proposed. a component (C) a hydroxyl group-containing acrylic rubber, (D) an organic fine particle, and (E) conductive particles; wherein the (B) thermosetting component contains (b1) a phosphorus-containing acrylate; the (C) contains The weight average molecular weight of the hydroxy acrylic rubber is 1,000,000 or more. The (D) organic fine particles contain (d1) polybutadiene-containing fine particles (for example, refer to JP-A-2008-274019).

In addition, an acrylic rubber is used for the anisotropic conductive film for the purpose of improving the adhesiveness and the like (for example, refer to JP-A-2007-80522 and International Publication No. 2001/82363). Since this acrylic rubber is a rubber material, it can be expected to relieve stress.

However, in the anisotropic conductive film, a material which relaxes the stress such as the acrylic rubber generally causes a problem that the connection reliability is lowered.

Therefore, there is a demand for an anisotropic conductive film which can prevent warpage of a substrate and which can provide excellent connection reliability, a connection method using the anisotropic conductive film, and a bonded body using the anisotropic conductive film.

The object of the present invention is to solve the above problems and achieve the following objects. That is, an object of the present invention is to provide an anisotropic conductive film which can prevent warpage of a substrate and obtain excellent connection reliability, and provides a connection method using the anisotropic conductive film, and using the respective directions A bonded body of an anisotropic conductive film.

The method for solving this problem is as follows. that is:

<1> An anisotropic conductive film, comprising: a film forming resin, a curable resin, a curing agent, a carboxyl group-containing acrylic rubber, and conductive particles; The carboxyl group-containing acrylic rubber has a glass transition temperature of 18 ° C or less and a weight average molecular weight of 75,000 or more.

<2> The anisotropic conductive film according to <1>, wherein the carboxyl group-containing acrylic rubber has an acid value of 5 mgKOH/g to 40 mgKOH/g, a glass transition temperature of -30 ° C to 15 ° C, and a weight average molecular weight. It is 100,000~900,000.

The anisotropic conductive film according to any one of <1> to <2> wherein the content of the carboxyl group-containing acrylic rubber is relative to the film forming resin, the curable resin, the hardener, and the content The total amount of the carboxyl group acrylic rubber is from 1% by mass to 15% by mass.

<4> A connection method for connecting an end of a substrate to an anisotropic conductive connection of a terminal of an electronic component, comprising: a first arrangement step of arranging the <1> to <3> on a terminal of the substrate An anisotropic conductive film according to any one of the preceding claims, wherein the electronic component is disposed on the anisotropic conductive film such that a terminal of the electronic component is in contact with the anisotropic conductive film; The heating and pressurizing step heats and pressurizes the electronic component by heating the pressing member.

<5> A bonded body comprising a substrate including a terminal, an electronic component including the terminal, and an anisotropic conductive electrode interposed between the substrate and the electronic component and electrically connecting the terminal of the substrate to the terminal of the electronic component The anisotropic conductive film of any one of <1> to <3>.

According to the present invention, it is possible to provide an anisotropic conductive film which can solve various problems in the prior art, achieve the above object, prevent substrate warpage and obtain excellent connection reliability, and provide an anisotropic conductive film using the anisotropic conductive film. A joining method, and a joined body using the anisotropic conductive film.

1‧‧‧ glass substrate

2‧‧‧ hardened material

3‧‧‧Electronic parts

4‧‧‧ probe

Fig. 1 is a schematic view for explaining a method of measuring the amount of warpage.

(anisotropic conductive film)

The anisotropic conductive film of the present invention contains at least a film-forming resin, a curable resin, a curing agent, a carboxyl group-containing acrylic rubber, and conductive particles, and may contain other components as needed.

The anisotropic conductive film is an anisotropic conductive film in which the terminals of the substrate are anisotropically electrically connected to the terminals of the electronic component.

<Film forming resin>

The film-forming resin is not particularly limited and may be appropriately selected depending on the purpose, for example, a phenoxy resin, an unsaturated polyester resin, a saturated polyester resin, an urethane resin, a butadiene resin, and a polyfluorene. Imine resin, polyamide resin, polyolefin resin, and the like. The film-forming resin may be used alone or in combination of two or more. Among these resins, a phenoxy resin is preferred from the viewpoints of film formability, workability, and connection reliability.

The phenoxy resin is, for example, a resin synthesized from bisphenol A and epichlorohydrin.

As the phenoxy resin, a suitable synthesizer can be used, and a commercially available product can also be used.

The content of the film-forming resin is not particularly limited and may be appropriately selected depending on the purpose.

<curable resin>

The curable resin is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include an epoxy resin and an acrylate resin.

- epoxy resin -

The epoxy resin is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a novolac type epoxy resin, and the like. Epoxy resin, alicyclic epoxy resin, etc. These resins may be used alone or in combination of two or more.

-Acrylate resin -

The acrylate resin is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, and ethylene glycol. Diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy-1,3- Dipropenyl methoxypropane, 2,2-bis[4-(propylene decyloxymethoxy)phenyl]propane, 2,2-bis[4-(propylene decyloxy ethoxy) benzene Propane, dicyclopentenyl acrylate, tricyclodecyl acrylate, tris(propylene decyloxyethyl) isocyanurate, urethane acrylate, and the like. These compounds may be used alone or in combination of two or more.

In addition, for example, the acrylate may be used alone or in combination of two or more.

The content of the curable resin is not particularly limited and may be appropriately selected depending on the purpose.

<hardener>

The curing agent is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include an imidazole, an organic peroxide, an anionic curing agent, and a cationic curing agent.

Examples of the imidazoles include 2-ethyl 4-methylimidazole.

As the organic peroxide, for example, lauryl peroxide, butyl peroxide, Benzyl peroxide, dilauroyl peroxide, dibutyl peroxide, Peroxydicarbonate, benzamidine peroxide, and the like.

As the anion-based curing agent, for example, an organic amine or the like can be mentioned.

Examples of the cationic curing agent include a phosphonium salt, a phosphonium salt, and an aluminum chelating agent.

The combination of the curable resin and the curing agent is not particularly limited and may be appropriately selected depending on the purpose, but it is preferably a combination of the epoxy resin and the cationic curing agent, and the acrylate resin and the organic resin. A combination of oxides.

<Carboxy-containing acrylic rubber>

The carboxyl group-containing acrylic rubber is not particularly limited as long as it has a glass transition temperature of 18° C. or less and a weight average molecular weight of 75,000 or more, and can be appropriately selected depending on the purpose.

The carboxyl group-containing acrylic rubber is an acrylic rubber having a carboxyl group.

The acrylic rubber is, for example, a polymer containing constituent units derived from acrylic acid, acrylate, methacrylic acid, methyl acrylate, carboxyl group-containing acrylate, carboxyl group-containing methyl acrylate, and the like. Derivatives, etc.

The acrylic rubber is, for example, a rubber containing acrylate as a main constituent component.

As the copolymerizable monomer constituting the polymer, for example, acrylic acid, methacrylic acid, butyl acrylate, methyl butyl acrylate, ethyl acrylate, methyl methacrylate, methyl acrylate, methacrylic acid Ester, acrylonitrile, and the like.

The carboxyl group in the carboxyl group-containing acrylic rubber may be a carboxyl group derived from acrylic acid or methacrylic acid, or a carboxyl group derived from another carboxyl group-containing copolymerizable monomer. Examples of the other carboxyl group-containing copolymerizable monomer include 2-propenylmethoxyethyl succinic acid, 2-methylpropenyloxyethyl succinic acid, and 2-acryl decyloxy B. Phthalic acid, 2-methylpropenyloxyethyl phthalic acid, 2-propenyl methoxyethyl hexahydrate phthalic acid, 2-methylpropenyl methoxyethyl hexahydrate benzene Formic acid, isaconic acid, fumaric acid, maleic acid, and the like.

The acid value of the carboxyl group-containing acrylic rubber is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 mgKOH/g or more, more preferably 3 mgKOH/g to 40 mgKOH/g, still more preferably 5 mgKOH. /g~40 mgKOH/g, particularly preferably 5 mgKOH/g~30 mgKOH/g. When the acid value is in this particularly preferable range, there is an advantage that the substrate warpage and the connection reliability can be highly improved.

The acid value can be measured, for example, according to Japanese Industrial Standard "JIS K 2501-2003 Petroleum Products and Lubricating Oil - Neutralization Value Test Method".

The glass transition temperature of the carboxyl group-containing acrylic rubber is not particularly limited as long as it is 18 ° C or lower, and may be appropriately selected depending on the purpose, but is preferably -40 ° C to 15 ° C, more preferably -30 ° C to 15 ° C. Very good is -30 ° C ~ 5 ° C. When the glass transition temperature is within this particularly preferable range, there is an advantage that the substrate warpage and the connection reliability can be highly improved.

The glass transition temperature can be obtained, for example, using a theoretical glass transition temperature calculation formula (FOX type). Specifically, according to the FOX formula (TGFox, Bull. Am. Physics Soc., Vol. 1, No. 3, p. 123 (1956)), Tgn of individual polymers constituting various monomers constituting a polymer is used. It is obtained by the following formula (1).

1/Tg=Σ(Wn/Tgn) (1)

In the formula (1), Tgn is a glass transition temperature Tg of a single polymer of each monomer component, Wn is a weight fraction of each monomer component, and Tg is a glass transition temperature of the copolymer. The temperature in the formula (1) is an absolute temperature.

The weight average molecular weight of the carboxyl group-containing acrylic rubber is not particularly limited as long as it is 75,000 or more, and may be appropriately selected depending on the purpose, but is preferably 100,000 to 1,000,000, more preferably 100,000 to 900,000, and particularly preferably 700,000 to 900,000. When the weight average molecular weight is in this particularly preferable range, it has an advantage of being able to highly prevent the warpage of the substrate and the reliability of the connection.

The weight average molecular weight can be measured by a gel permeation chromatography (GPC, Gel Permeation Chromatography). For example, measurement was performed using Shodex GPC (manufactured by Showa Denko Co., Ltd.). The calibration curve is made using standard polystyrene.

The content of the carboxyl group-containing acrylic rubber is not particularly limited, and may be appropriately selected depending on the purpose, but the total amount of the resin, the curable resin, the curing agent, and the carboxyl group-containing acrylic rubber is formed with respect to the film. It is preferably from 1% by mass to 15% by mass, more preferably from 3% by mass to 10% by mass, particularly preferably from 3% by mass to 5% by mass. When the content is in this particularly preferable range, there is an advantage that the substrate warpage and the connection reliability can be highly improved.

<Electrically conductive particles>

The conductive particles are not particularly limited, and may be appropriately selected depending on the purpose, and examples thereof include metal particles and metal-coated resin particles.

The metal particles are not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include nickel, cobalt, silver, copper, gold, palladium, and solder. These metals may be used alone or in combination of two or more.

Among these metals, nickel, silver, and copper are preferable. These metal particles are intended to prevent oxidation of the surface, and gold or palladium may be applied to the surface. Further, it is also possible to use a metal protrusion on the surface or to apply an insulating film to an organic substance.

The metal-coated resin particles are not particularly limited as long as the surface of the resin particles is coated with a metal, and may be appropriately selected depending on the purpose. For example, the surface of the resin particles is made of nickel, silver, solder, copper, or gold. And particles coated with at least one of palladium and the like. Further, it is also possible to use a metal protrusion on the surface or an insulation film by an organic substance. In the case of considering the connection of low resistance, particles in which the surface of the resin particle is coated with silver are preferable.

The method of coating the resin particles with the metal is not particularly limited, and may be appropriately selected depending on the purpose, for example, an electroless plating method, a sputtering method, or the like.

The material of the resin particles is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include a styrene-divinylbenzene copolymer, a Benzoguanamine resin, a crosslinked polystyrene resin, and acrylic acid. Resin, styrene-cerium oxide composite resin, and the like.

The conductive particles may have conductivity when they are anisotropically conductively connected. For example, even if the particles of the insulating film are applied to the surface of the metal particles, the particles may be deformed to cause the metal particles to be exposed when they are anisotropically conductively connected.

The average particle diameter of the conductive particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 μm to 50 μm, more preferably 2 μm to 25 μm, and particularly preferably 2 μm to 10 μm. The average particle diameter is an average value of the particle diameters of any of the ten conductive particles measured. The particle diameter can be measured, for example, by observation with a scanning electron microscope.

<Other ingredients>

The other component is not particularly limited and may be appropriately selected depending on the purpose, for example, a decane coupling agent, a filler, a softening agent, a curing accelerator, an antioxidant, a coloring agent (pigment, dye), an organic solvent, and an ion supplement. Collecting agents, etc.

The content of the other component is not particularly limited and may be appropriately selected depending on the purpose.

<Substrate>

The substrate is not particularly limited as long as it has a terminal and is an object of anisotropic conductive connection using the anisotropic conductive film, and may be appropriately selected depending on the purpose, for example, a glass substrate having a terminal, A plastic substrate having a terminal or the like.

Examples of the glass substrate having the terminal include an indium tin oxide (ITO) glass substrate, an indium zinc oxide (IZO, Indium Zinc Oxide) glass substrate, and other glass pattern substrates.

Among these substrates, an ITO glass substrate and an IZO glass substrate are preferable.

The material and structure of the plastic substrate having the terminal are not particularly limited, and may be appropriately selected depending on the purpose, for example, a rigid substrate having a terminal, a flexible substrate having a terminal, or the like.

The average thickness of the substrate is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 0.1 mm to 1.0 mm, more preferably 0.2 mm to 0.8 mm.

The average thickness is an average value when the thickness of any 10 places of the substrate is set.

<electronic parts>

The electronic component is not particularly limited as long as it has a terminal and is an object of anisotropic conductive connection using the anisotropic conductive film, and may be appropriately selected depending on the purpose, and may be, for example, Integrated circuit (IC), Tape Automated Bonding (TAP), liquid crystal panel, etc. As the IC, for example: flat panel display (FPD, Flat) LCD chip for LCD screen control in Panel Display).

The shape of the electronic component is not particularly limited, and may be appropriately selected depending on the purpose, and for example, a rectangular shape, a square shape, or the like in a plan view.

The combination of the substrate and the electronic component is not particularly limited, and may be appropriately selected depending on the purpose, and may be, for example, soft glass bonding (FOG, Flex-on-Glass) or wafer glass bonding (COG, Chip-on). -Glass), Chip-on-Flex (COF), Soft-Board (FOB), Flex-on-Board (FOF, Flex-on-Flex), etc. The combination of the substrate and the electronic component of the method.

The average thickness of the anisotropic conductive film is not particularly limited and may be appropriately selected depending on the purpose, and is preferably 5 μm to 100 μm, more preferably 10 μm to 60 μm, and particularly preferably 15 μm to 30 μm.

The method for producing the anisotropic conductive film is not particularly limited, and may be appropriately selected depending on the purpose, for example, the film forming resin, the curable resin, the curing agent, the carboxyl group-containing acrylic rubber, and the conductive material. A method of applying an anisotropic conductive composition obtained by mixing particles to a polyethylene terephthalate (PET) film subjected to release treatment.

(connection method)

The connecting method of the present invention comprises at least a first configuration step, a second configuration step, a heating and pressurizing step, and further includes other steps according to requirements.

This connection method is a method of anisotropically electrically connecting the terminals of the substrate to the terminals of the electronic component.

The substrate and the electronic component are not particularly limited, and may be appropriately selected depending on the purpose, and are, for example, a substrate and an electronic component exemplified in the description of the anisotropic conductive film of the present invention.

<First Configuration Step>

The first configuration step is as long as the anisotropic conductive thin of the present invention is disposed on the terminal of the substrate The step of the film is not particularly limited and may be appropriately selected depending on the purpose.

<Second configuration step>

In the second arrangement step, the step of disposing the electronic component on the anisotropic conductive film so that the terminal of the electronic component contacts the anisotropic conductive film is not particularly limited. Appropriate choice according to the purpose.

<heating and pressurizing step>

The heating and pressurizing step is not particularly limited as long as it is a step of heating and pressurizing the electronic component by a heating and pressing member, and may be appropriately selected depending on the purpose.

The heating and pressing member is, for example, a pressing member having a heating mechanism or the like. As a pressurization member which has this heating means, a heater etc. are mentioned, for example.

The temperature of the heating is not particularly limited and may be appropriately selected depending on the purpose, but is preferably from 100 ° C to 180 ° C.

The pressure to be pressurized is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 0.5 MPa to 100 MPa.

The time for the heating and pressurization is not particularly limited and may be appropriately selected depending on the purpose, but is preferably from 0.5 second to 10 seconds.

(joined body)

The bonded body of the present invention has at least a substrate, an electronic component, and a cured product of an anisotropic conductive film, and may have other members depending on the demand.

The substrate and the electronic component are not particularly limited, and may be appropriately selected depending on the purpose, and for example, the substrate and the electronic component exemplified in the description of the anisotropic conductive film of the present invention.

The anisotropic conductive film is an anisotropic conductive film of the present invention.

a cured product of the anisotropic conductive film interposed between the substrate and the electronic component to make the base The terminal of the board is electrically connected to the terminal of the electronic component.

The joined body can be produced, for example, by the joining method of the present invention.

[Examples]

Hereinafter, the examples of the invention are described, but the invention is not limited by the examples.

(Manufacturing Examples 1 to 15) <Synthesis of carboxyl group-containing acrylic rubber No. 1 to 15>

The (meth) acrylate monomer, 2-(meth) propylene decyl oxyethyl succinic acid, is mixed at a specific mixing ratio in such a manner that the obtained acrylic rubber forms a desired acid value and glass transition temperature. a carboxyl group-containing (meth) acrylate such as 2-(methyl) propylene decyloxyethyl phthalic acid or 2-(methyl) propylene decyloxyethyl hexahydrate phthalic acid, and water, and These materials were placed in a reaction vessel, and a sufficient nitrogen substitution was performed while stirring. Next, a specific amount of a peroxide (activator) is supplied to the mixture so that the obtained acrylic rubber forms a desired weight average molecular weight to carry out polymerization.

The acid value, glass transition temperature and weight average molecular weight of the synthesized carboxyl group-containing acrylic rubber are shown in Tables 1 to 4. Further, the acid value, the glass transition temperature, and the weight average molecular weight were determined in the following manner.

<acid price>

The acid value is measured in accordance with the Japanese Industrial Standard "JIS K 2501-2003 Petroleum Products and Lubricants - Neutralization Test Method".

<glass transition temperature>

The glass transition temperature (Tg) was determined using a theoretical glass transition temperature calculation formula (FOX type).

Specifically, according to the FOX formula (TGFox, Bull. Am. Physics Soc., Vol. 1, No. 3, p. 123 (1956)), the Tgn of the individual polymer constituting each monomer of the polymer is used, The following formula (1) is obtained.

1/Tg=Σ(Wn/Tgn) (1)

In the formula (1), Tgn is a glass transition temperature Tg of a single polymer of each monomer component, Wn is a weight fraction of each monomer component, and Tg is a glass transition temperature of the copolymer. The temperature in the formula (1) is an absolute temperature.

<weight average molecular weight>

The weight average molecular weight is determined by gel permeation chromatography (GPC). The measurement was performed using Shodex GPC (manufactured by Showa Denko Co., Ltd.). A calibration curve is made using standard polystyrene.

(Example 1) <Production of anisotropic conductive film>

The following materials were mixed in the blending amounts shown in Table 1 to obtain a composition: phenoxy resin (trade name: YP-50, manufactured by Nippon Steel Chemical Co., Ltd., film-forming resin), bisphenol A type Epoxy resin (trade name: EP-828, manufactured by Mitsubishi Chemical Corporation, curable resin), decane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.), cationic curing agent (trade name) : SI-60L, manufactured by Sanshin Chemical Industry Co., Ltd.) and the carboxyl group-containing acrylic rubber No. 1 obtained in Production Example 1. Conductive particles (trade name: AUL704, manufactured by Sekisui Chemical Co., Ltd.) were dispersed in the obtained composition to obtain an anisotropic conductive composition. The dispersion of the conductive particles in the obtained anisotropic conductive film was 50,000 particles/mm ² .

The obtained anisotropic conductive composition was applied onto a polyethylene terephthalate film so as to have an average thickness of 20 μm to obtain an anisotropic conductive film.

<Manufacture of bonded body and evaluation of joined body>

The joined body was produced by the following method, and the following evaluation was performed. The results are shown in Table 1.

An ITO wiring board having an average thickness of 0.5 mm patterned with an ITO (Indium Tin Oxide) film was used as a glass substrate.

An IC wafer (1.8 mm × 20 mm, t (thickness) = 0.5 mm, Au-coated bump 30 μm × 85 μm, h (height) = 15 μm) was used as an electronic component.

The anisotropic conductive film was cut into a specific width and attached to the ITO wiring board. In After the IC wafer was temporarily fixed thereto, a heater coated with Teflon (registered trademark) having an average thickness of 50 μm was used as a buffer material, and joined under the bonding conditions of "160 ° C, 60 MPa, and 5 seconds" to Finish the joint.

<<Connection reliability (on resistance)>>

The initial resistance value of the obtained joined body and the resistance value after a 500-hour temperature humidity test (TH test, Thermal Humidity Test) at 85 ° C and 85% RH were measured by the following methods. The results are shown in Table 1.

A multi-digit multimeter (product name and serial number: Digital multi-meter 7555, manufactured by Yokogawa Electric Co., Ltd.) was used, and the resistance value at a current of 1 mA was set by a four-point probe measurement method.

<<The amount of warpage>>

For the measurement of the amount of warpage, a probe type surface roughness meter (trade name: SE-3H, manufactured by Kosaka Research Co., Ltd.) was used. As shown in Fig. 1, the surface of the glass substrate 1 to which the electronic component 3 is not connected is placed on the upper side of the cured product 2 of the anisotropic conductive film in the bonded body, and the plane of the glass substrate 1 is horizontal. Joint body. Next, as shown in FIG. 1, the probe 4 of the probe type surface roughness is used to scan the surface of the glass substrate 1 on the side opposite to the surface on which the electronic component 3 is connected. The probe 4 scans the surface in the longitudinal direction of the electronic component 3 from a side located at one side of the electronic component 3 to a distance of 20 mm from the other side opposite to the side. Next, when scanning with the probe 4, the displacement in the vertical direction was measured and used as the amount of warpage. The amount of warpage was measured for 10 samples, and the amount of warpage was obtained from the average value. The results are shown in Table 1.

Further, in the case where the warpage is convex, the amount of warpage is represented by a positive numerical value, and when the warpage is concave, the amount of warpage is represented by a negative numerical value.

(Examples 2 to 24 and Comparative Examples 1 to 3)

An anisotropic conductive film was produced in the same manner as in Example 1 except that the blending of the anisotropic conductive composition was changed to the blending shown in Tables 1 to 4 in Example 1.

The same evaluation as in Example 1 was carried out on the obtained anisotropic conductive film. The results are shown in Tables 1 to 4.

The relative proportions of the blending amounts in Tables 1 to 4 correspond to the relative proportions of the contents of the respective components in the anisotropic conductive film.

The film-forming resin used in Example 22 was Epikote 1256 (manufactured by Nippon Steel Chemical Co., Ltd.).

The curable resin used in Example 23 was YD-128 (manufactured by Mitsubishi Chemical Corporation).

The hardener used in Example 24 was SI-100L (manufactured by Sanshin Chemical Industry Co., Ltd.).

In Examples 1 to 24, the amount of warpage of the substrate was 15.0 μm or less, and under 85 ° C and 85% RH, the on-resistance after 500 hours passed was 10.0 Ω or less, which was able to prevent warpage of the substrate and excellent. Connection reliability.

In particular, the acid value of the carboxyl group-containing acrylic rubber is 5 mgKOH/g to 30 mgKOH/g, the glass transition temperature is -30 ° C to 5 ° C, the weight average molecular weight is 700,000 to 900,000, and the content of the carboxyl group-containing acrylic rubber is relative to When the total amount of the film-forming resin, the curable resin, the curing agent, and the carboxyl group-containing acrylic rubber is 3% by mass to 5% by mass, the amount of warpage of the substrate is 13.0 μm or less, and is 85 ° C and 85% RH. When the on-resistance after 500 hours has elapsed is 5.0 Ω or less, the warpage of the substrate can be prevented and the connection reliability can be ensured (for example, refer to Examples 2-6, 10, and 12).

On the other hand, in the case where the glass transition temperature of the carboxyl group-containing acrylic rubber is 20 ° C (Comparative Example 1), the weight average molecular weight is 50,000 (Comparative Example 2), or the anisotropic conductive film does not have carboxyl group-containing acrylic acid In the case of rubber (Comparative Example 3), at least one of the following cases was formed: the warpage of the substrate exceeded 15.0 μm; and at 85 ° C and 85% RH, the on-resistance after 500 hours passed exceeded 10.0 Ω, so It also prevents substrate warpage and excellent connection reliability.

[Industrial use possibilities]

The anisotropic conductive film of the present invention is suitable for connection to a substrate and an electronic component because it can prevent warpage of the substrate and obtain excellent connection reliability.

1‧‧‧ glass substrate

2‧‧‧ hardened material

3‧‧‧Electronic parts

4‧‧‧ probe

Claims (7)

An anisotropic conductive film which is an anisotropic conductive film which is anisotropically electrically connected to a terminal of a substrate and a terminal of an electronic component, and comprises: a film forming resin, a curable resin, a hardener, a carboxyl group-containing acrylic rubber, and a conductive film. a particle-containing acrylic rubber having a glass transition temperature of 18 ° C or less and a weight average molecular weight of 75,000 or more, wherein the content of the carboxyl group-containing acrylic rubber is relative to a film-forming resin, a curable resin, a hardener, and the like. The total amount of the carboxyl group acrylic rubber is from 1% by mass to 15% by mass. The anisotropic conductive film according to claim 1, wherein the carboxyl group-containing acrylic rubber has an acid value of 5 mgKOH/g to 40 mgKOH/g, a glass transition temperature of -30 ° C to 15 ° C, and a weight average molecular weight of 100,000~900,000. The anisotropic conductive film according to claim 1, wherein the content of the carboxyl group-containing acrylic rubber is based on the total amount of the film-forming resin, the curable resin, the curing agent, and the carboxyl group-containing acrylic rubber. 1% by mass to 10% by mass. The anisotropic conductive film according to claim 1, wherein the content of the carboxyl group-containing acrylic rubber is based on the total amount of the film-forming resin, the curable resin, the curing agent, and the carboxyl group-containing acrylic rubber. 3% by mass to 5% by mass. An anisotropic conductive film which is an anisotropic conductive film which anisotropically conducts a carboxy group of a terminal of a substrate and a terminal of an electronic component, and comprises: a film forming resin, a curable resin, a hardener, a carboxyl group-containing acrylic rubber, and a conductive particle; the carboxyl group-containing acrylic rubber has a glass transition temperature of 18 ° C or less and a weight average molecular weight of 75,000 or more, wherein The acid value of the carboxyl group-containing acrylic rubber is 5 mgKOH/g to 40 mgKOH/g. A connection method is a connection method for anisotropic conductive connection between a terminal of a substrate and a terminal of an electronic component, comprising: a first configuration step of disposing at a terminal of the substrate as in any one of claims 1 to 5 of the patent application scope The anisotropic conductive film according to the item; the second step of disposing the electronic component on the anisotropic conductive film so that the terminal of the electronic component is in contact with the anisotropic conductive film; In the pressing step, the electronic component is heated and pressurized by heating the pressing member. A bonded body comprising a substrate including a terminal, an electronic component including the terminal, and a cured product of an anisotropic conductive film interposed between the substrate and the electronic component and electrically connecting the terminal of the substrate to the terminal of the electronic component The anisotropic conductive film is an anisotropic conductive film according to any one of claims 1 to 5.