KR20150111278A - Anisotropic conductive film, connection method, and joined structure - Google Patents

Abstract

The present invention relates to an anisotropic conductive film, which contains: polyester urethane (A) having transition temperature less than 60°C and the average molecular weight less than or equal to 20,000; polyester urethane (B) having transition temperature greater than or equal to 60°C and less than or equal to 100°C and the average molecular weight more than or equal to 20,000 and less than or equal to 30,000; radically polymerized compounds; and organic peroxide compounds.

Description

TECHNICAL FIELD [0001] The present invention relates to an anisotropic conductive film, an anisotropic conductive film, a connection method,

The present invention relates to an anisotropic conductive film, a connection method using the anisotropic conductive film, and a junction body manufactured using the connection method.

The anisotropic conductive film is used for a case in which terminals of a flexible printed circuit board (FPC) or an IC (Integrated Circuit) chip are electrically connected to electrodes formed on a glass substrate of an LCD (Liquid Crystal Display) And is used in a case where various terminals are bonded together and electrically connected to each other.

Conventionally, in connection with the anisotropic conductive film, if the operation is carried out at 160 캜 or more, thermal damage may occur depending on the member. If the operation is carried out at 4 MPa or more, physical damage may occur depending on the member. Sec, there is a problem that the production efficiency is not so good.

Thus, in connection with the connection using an anisotropic conductive film in recent years, there has been an increasing demand for suppressing heat and physical damage to the member and improving the production efficiency. Therefore, it is possible to provide a semiconductor device which has excellent connection reliability, high bonding strength, good degree of crushing of the conductive particles and low anisotropic conductivity from the substrate at a low temperature of about 140 ° C, a low pressure of about 3 MPa, A connection by an anisotropic conductive film without lifting of the film is required.

A technique has been proposed in which an adhesive having an acid amount of 5 KOHmg / g to 500 KOHmg / g is used as an adhesive for circuit connection (for example, see JP-A 2007-169632). However, in the proposed technique, since the circuit connection is performed at 4 MPa (high pressure) for 20 seconds (for a long time), there is a problem that physical damage is given to the member and the production efficiency is further lowered.

A technique has been proposed in which circuit connection is carried out at a low pressure by making the space between opposing electrodes narrower than the diameter of the conductive particles so that the conductive particles are pushed against the opposing electrodes and ensuring conduction between the electrodes Japanese Unexamined Patent Application Publication No. 2007-169632). However, in this proposed technique, there is a problem that heat dissipation is given to the member because the circuit connection is performed at 170 DEG C (high temperature).

There has been proposed a technique which makes it possible to connect an anisotropic conductive film in a short time by using a radical-curing adhesive composition containing a thermoplastic resin, a radical polymerizing compound and a radical polymerization initiator as an adhesive composition (see, for example, 07/046189). However, in this proposed technique, since the connection by the anisotropic conductive film is carried out at 160 DEG C (high temperature), there is a problem that thermal damage is given to the member.

Further, there has been proposed a technique of obtaining a strong adhesive strength to an inorganic substrate by using an adhesive composition containing a thermoplastic resin, a radically polymerizable compound, a radical generator, and a silane coupling agent having a solubility parameter of 9.0 or more See, for example, Japanese Patent Laid-Open No. 2007-177204). However, in the proposed technique, since the circuit connection is carried out at 175 ° C (high temperature) for 15 seconds (for a long time), there is a problem that thermal damage is given to the member and the production efficiency is further lowered.

Therefore, in these proposed techniques, the connection reliability is excellent, the bonding strength is high, and the degree of crushing of the conductive particles is low, that is, the bonding reliability is high, the low temperature of about 140 캜, the low pressure of about 3 MPa, There is a problem in that connection using an anisotropic conductive film free from lifting from the substrate can not be realized.

Therefore, it is an object of the present invention to provide an anisotropic conductive film which is excellent in connection reliability, high in bonding strength, good in crushing degree of conductive particles, Methods and assemblies are required.

It is an object of the present invention to solve the above-mentioned conventional problems and to achieve the following objects. That is, an object of the present invention is to provide an anisotropic conductive film which is excellent in connection reliability, high in bonding strength, good in crushing degree of conductive particles, And to provide a connection method using a film and a bonded body.

Means for solving the above problems are as follows. In other words,

(1) A polyester urethane (A) having a number average molecular weight of 20,000 or less and a glass transition temperature of less than 60 占 폚,

A polyester urethane (B) having a number average molecular weight of 20,000 or more and 30,000 or less and a glass transition temperature of 60 占 폚 or more and 100 占 폚 or less,

A radical polymerizable material,

And is an anisotropic conductive film characterized by containing an organic peroxide.

<2> The anisotropic conductive film according to <1>, wherein the mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) is 30:70 to 80:20.

<3> The ratio [Mn (B) / Mn (A)] of the number average molecular weight [Mn (A)] of the polyester urethane (A) to the number average molecular weight [Mn (B)] of the polyester urethane 2.0 or more and 3.0 or less,

The anisotropic conductive film according to any one of <1> to <2>, wherein the total content of the polyester urethane (A) and the polyester urethane (B) is 18% by mass to 75% by mass.

&Lt; 4 >, wherein the radical polymerizable substance contains a bifunctional (meth) acrylate and a trifunctional (meth) acrylate,

(Meth) acrylate: trifunctional (meth) acrylate] in a weight ratio of the bifunctional (meth) acrylate to the trifunctional (meth) acrylate is from 30:70 to 80:20,

The anisotropic conductive film according to any one of <1> to <3>, wherein the total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate is 18% by mass to 75% by mass.

<5> An anisotropic conductive film according to any one of <1> to <4>, which contains imidazole silane.

&Lt; 6 > A connection method for anisotropic conductive connection between a terminal of a substrate and a terminal of an electronic component,

An attaching step of attaching the anisotropic conductive film described in any one of < 1 > to < 5 > onto a terminal of the substrate;

A mounting step of placing the electronic component on the anisotropic conductive film,

And a heating and pressing step of heating and pressing the electronic component with a heating and pressing member,

And the pressing in the heating and pressing step is 1 MPa to 3 MPa.

&Lt; 7 > A bonded body produced by using the connection method according to the above-mentioned < 6 >.

According to the present invention, it is possible to solve the above-mentioned conventional problems and to achieve the above object, and to provide a conductive paste which has excellent reliability of connection at a low temperature, a low pressure and a short time, And an anisotropic conductive film which can be connected without hesitation from the substrate, and a connection method and a junction body using the anisotropic conductive film.

(Anisotropic conductive film)

The anisotropic conductive film of the present invention contains at least a polyester urethane (A), a polyester urethane (B), a radically polymerizable substance and an organic peroxide, and further contains other components as required.

&Lt; Polyester urethane (A) >

The number average molecular weight of the polyester urethane (A) is 20,000 or less, preferably 8,000 or more and 20,000 or less, more preferably 10,000 or more and 20,000 or less, and particularly preferably 10,000 or more and 15,000 or less. When the number average molecular weight of the polyester urethane (A) exceeds 20,000, the conductive particles can not be sufficiently crushed and the connection becomes unstable.

The glass transition temperature of the polyester urethane (A) is preferably less than 60 占 폚, and more preferably 40 占 폚 or more and less than 60 占 폚. If the glass transition temperature of the polyester urethane (A) is 60 占 폚 or higher, the conductive particles can not be sufficiently crushed and the connection becomes unstable.

In the present invention, the polyester urethane is a polymer having an ester bond and a urethane bond.

&Lt; Polyester urethane (B)

The number average molecular weight of the polyester urethane (B) is 20,000 or more and 30,000 or less, preferably 22,000 or more and 28,000 or less. When the number average molecular weight of the polyester urethane (B) is less than 20,000, the connection reliability may not be excellent. When the number average molecular weight is more than 30,000, the conductive particles can not be sufficiently crushed and the connection becomes unstable.

The glass transition temperature of the polyester urethane (B) is preferably 60 占 폚 to 100 占 폚, and preferably 65 占 폚 to 85 占 폚. If the glass transition temperature of the polyester urethane (B) is less than 60 캜, the connection reliability is not excellent, and if it exceeds 100 캜, the adhesion is not excellent.

The number average molecular weight of the polyester urethane (A) and the polyester urethane (B) can be determined, for example, by gel permeation chromatography (GPC). In the GPC, standard polystyrene is used as the calibration curve.

The glass transition temperature of the polyester urethane (A) and the polyester urethane (B) can be determined, for example, by differential scanning calorimetry (DSC). In the above DSC, for example, 5 mg sample contained in an aluminum pan is used and the temperature is raised from 20 캜 to 150 캜 at a temperature raising rate of 10 캜 / minute to carry out the measurement.

In the anisotropic conductive film, a method for confirming whether the polyester urethane (A) and the polyester urethane (B) are used in combination is not particularly limited and may be appropriately selected depending on the purpose. For example, And the like.

A resin component (a mixture of the polyester urethane (A) and the polyester urethane (B)) is extracted from the anisotropic conductive film using THF (tetrahydrofuran). The extracted resin component is measured by high performance liquid chromatography (HPLC).

When two peaks (bimodal) are obtained in the measurement results, they are separated and collected based on the peaks to obtain two resin components. The number average molecular weight and the glass transition temperature are measured for each of the obtained two resin components by the above-mentioned method. Further, even if two peaks are close to each other and one side is seen as the shoulder of the other, it is judged to be bending.

In the case where the molecular weights of the polyester urethane (A) and the polyester urethane (B) are close to each other and the two peaks can not be clearly obtained in the HPLC measurement results, separation by the difference in solvent solubility is carried out (A) and the polyester urethane (B) by, for example, separating the polyester urethane (A) and the polyester urethane (B) by separating using a specific gravity difference, Can be distinguished.

The mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) is preferably from 30:70 to 80:20, and more preferably from 40:60 to 60:40. When the ratio of the polyester urethane (A) to the polyester urethane (A) in the mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) is less than 30: 70, If it exceeds 80: 20, the adhesive strength and the connection reliability may not be excellent.

The mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) in the anisotropic conductive film can be calculated, for example, And the polyester urethane (B) are used in combination, the mass of the polyester urethane (A) and the polyester urethane (B) taken separately may be used.

The ratio [Mn (B) / Mn (A)] of the number average molecular weight [Mn (A)] of the polyester urethane (A) to the number average molecular weight [Mn (B)] of the polyester urethane Or more, more preferably 2.0 or more and 3.0 or less. The ratio [Mn (B) / Mn (A)] of the number average molecular weight [Mn (A)] of the polyester urethane (A) to the number average molecular weight [Mn (B)] of the polyester urethane , The connection reliability may not be excellent. On the other hand, if it is more than 3.0, the conductive particles can not be sufficiently crushed and the connection may become unstable.

The total content of the polyester urethane (A) and the polyester urethane (B) in the anisotropic conductive film is preferably 18 mass% to 75 mass%, more preferably 30 mass% to 65 mass% . If the total content of the polyester urethane (A) and the polyester urethane (B) is less than 18% by mass, adhesion may be insufficient. If the total content exceeds 75% by mass, It may not be excellent.

<Radical Polymerizable Substance>

The radically polymerizable material is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include monofunctional (meth) acrylate, bifunctional (meth) acrylate, trifunctional (meth) acrylate, (Meth) acrylate, 5-functional (meth) acrylate, and 6-functional (meth) acrylate.

The (meth) acrylate in the present invention means "at least one of acrylate and methacrylate".

The monofunctional (meth) acrylate is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, phenoxyethyl Methacrylate, and the like.

The bifunctional (meth) acrylate is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) (Meth) acrylate, neopentyl glycol adipate di (meth) acrylate, ethylene glycol di (meth) acrylate, isocyanuric acid ethylene oxide modified di (meth) acrylate, (Meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl (meth) acrylate, ethylene oxide modified di (meth) acrylate, allylcyclohexyl (Meth) acrylate, and the like.

The trifunctional (meth) acrylate is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, (Meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylol propane tri (meth) acrylate, and tris (acryloyloxyethyl) isocyanurate. have.

The tetrafunctional (meth) acrylate is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate .

The pentafunctional (meth) acrylate is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include dipentaerythritol penta (meth) acrylate, propionic acid-modified dipentaerythritol penta (meth) acrylate And the like.

The hexafunctional (meth) acrylate is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate And the like.

The radically polymerizable substance may be used alone, or two or more kinds may be used in combination, or may be appropriately synthesized or commercially available products.

The total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate in the anisotropic conductive film is preferably 18 mass% to 75 mass%, more preferably 30 mass% to 65 mass% desirable. When the total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate in the anisotropic conductive film is less than 18 mass%, insufficient curing may occur and connection reliability may not be excellent, If it exceeds 75% by mass, adhesion may be insufficient.

<Organic peroxide>

The organic peroxide is not particularly limited and may be appropriately selected according to the purpose. Examples of the organic peroxide include lauroyl peroxide, butyl peroxide, benzyl peroxide, dilauryl peroxide, dibutyl peroxide, peroxydicarbonate, Benzoyl peroxide, and the like. These may be used alone, or two or more of them may be used in combination, or may be synthesized appropriately, or may be commercially available products.

The content of the organic peroxide in the anisotropic conductive film is not particularly limited and may be appropriately selected depending on the purpose, and it is preferably 0.1% by mass to 5% by mass.

&Lt; Other components >

The other components are not particularly limited and may be appropriately selected according to the purpose. Examples thereof include an imidazole-based, epoxy-based, methacryloxime, amino-based, vinyl-based, mercapto- Inorganic fillers such as silica, talc, titanium oxide, calcium carbonate and magnesium oxide, and softeners such as thermoplastic resins and rubber components. From the viewpoint of improving the adhesion to glass, A disazosilane is preferred.

(Connection method)

The connecting method of the present invention includes an attaching step, a placing step, and a heating and pressing step, and further includes other steps as necessary.

The connection method is a connection method for anisotropic conductive connection between a terminal of a substrate and a terminal of an electronic part.

<Attachment process>

The attaching step is not particularly limited as long as it is a step of attaching the anisotropic conductive film on the terminal of the substrate, and can be appropriately selected according to the purpose.

<< Substrate >>

The substrate is not particularly limited and may be appropriately selected according to the purpose. Examples of the substrate include a glass substrate, a plastic substrate, a ceramic substrate, and a flexible printed substrate.

<Wit process>

The placing step is not particularly limited as long as it is a step of placing the electronic part on the anisotropic conductive film, and can be appropriately selected according to the purpose.

<< Electronic Components >>

The electronic component is not particularly limited as long as it is an electronic component having a terminal to be subjected to anisotropic conductive connection. The electronic component can be appropriately selected according to the purpose. For example, an IC chip, a TAB tape, a liquid crystal panel, .

Examples of the IC chip include a liquid crystal screen control IC chip in a flat panel display (FPD).

<Heating and pressing step>

The heating and pressing step is not particularly limited as long as it is a step of heating and pressing the electronic component with a heating and pressing member, and can be appropriately selected according to the purpose.

The heating and pressing member is not particularly limited and may be appropriately selected according to the purpose. For example, a pressing member having a heating mechanism can be given. The pressing member having the heating mechanism is not particularly limited and can be appropriately selected in accordance with the purpose. For example, a heat tool and the like can be mentioned.

The heating temperature is not particularly limited and may be appropriately selected depending on the purpose. The heating temperature is preferably 130 ° C to 150 ° C, more preferably 130 ° C to 140 ° C.

The pressurizing pressure is 1 MPa to 5 MPa, preferably 1 MPa to 3 MPa.

The heating and pressurizing time is not particularly limited and may be appropriately selected depending on the purpose, and is preferably 2 seconds to 5 seconds.

(Bonded body)

The joined body of the present invention is manufactured by the above connecting method of the present invention.

Example

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Example 1)

&Lt; Preparation of anisotropic conductive film &

40 parts by mass of polyester urethane (A) (trade name: UR4410, manufactured by Toyobo Co., Ltd., number average molecular weight: 10,000; glass transition temperature: 56 캜), 40 parts by mass of polyester urethane (B) (trade name: UR8200, , 25 parts by mass of a bifunctional acrylate (trade name: M-1600, manufactured by Toagosei Co., Ltd., urethane acrylate), 10 parts by mass of a trifunctional acrylate (trade name: 25 parts by mass of an isocyanuric acid (trade name: M-315, manufactured by TOAGOSEI CO., LTD., Isocyanuric acid EO-modified di- and triacrylate) and 2 parts by mass of Initiator 1 (trade name: PEROIL L, manufactured by Nichiyu Corporation, aliphatic diacyl peroxide) , 2 parts by mass of Initiator 2 (trade name: NIPPER BW, manufactured by Nisshin Oil Co., Ltd., benzoyl peroxide), 1.5 parts by mass of a coupling agent (trade name: IM-1000, manufactured by JX Nikko Seiki Energy Co., Ltd., imidazole silane)Here (Au-Ni-plated resin particles, trade name: Micro Pearl AU, average particle size 4 ㎛, Sekisui Chemical Co., Ltd.) 2 parts by mass of the formulation to obtain the anisotropic conductive composition.

The obtained anisotropic conductive composition was coated on a release PET (polyethylene terephthalate, size 250 mm, average thickness 50 탆) and dried at 80 캜 to obtain an anisotropic conductive film having an average thickness of 25 탆 on the releasing PET.

&Lt; Preparation of a conjugate &

A bonded body was produced by the following method.

A glass substrate on which an ITO thin film was formed as an electronic component was used.

As a substrate, a flexible printed substrate (copper wiring: line / space = 100 占 퐉 / 100 占 퐉) was used.

On the substrate, the anisotropic conductive film (film width: 2.0 mm) was disposed. Subsequently, the electronic component was placed on the anisotropic conductive film. Subsequently, the electronic component was heated and pressed under the conditions of 140 占 폚, 2 MPa, and 5 seconds to obtain a bonded body.

&Lt; Measurement of continuity resistance &

The conduction resistance values at initial and after reliability (after the temperature 85 ° C and the humidity 85% RH for 250 hours) were measured for each junction body using a digital multimeter (34401A, manufactured by Agilent Technologies, Inc.). As a measurement method, a current of 1 mA was flowed using a four-terminal method.

And evaluated according to the following criteria. The results are shown in Table 1-1.

○: Less than 2 Ω

△: 2 Ω or more and less than 10 Ω

×: 10 Ω or more

<Measurement of Adhesive Strength>

A tensile tester (product number: RTC1201, manufactured by AND Co.) was used to measure the adhesive strength of the bonded body of the glass substrate and the COF (Chip On Film) after initial and reliability (after the temperature was 85 ° C and humidity 85% Respectively. The measurement was carried out at a measuring speed of 50 mm / min, and the bonding strength was measured when the COF was pulled up in the direction of 90 degrees.

And evaluated according to the following criteria. The results after initial and reliability are shown in Table 1-1.

?: 10 N / cm or more

?: 5 N / cm or more and less than 10 N / cm

?: 3 N / cm or more and less than 5 N / cm

X: less than 3 N / cm

&Lt; Degree of crushing of conductive particles &

With respect to the conductive particles contained in the anisotropic conductive film, the degree of crushing of the conductive particles after the production of the bonded body was observed using a metal microscope (trade name: MX50, manufactured by Olympus Corporation). When a clear deformation of the conductive particles was observed, it was judged that the conductive particles were crushed.

And evaluated according to the following criteria. The results are shown in Table 1-1.

○: The conductive particle is crushed

X: Conductive particles are not crushed

<My Delight>

An exothermic property of the anisotropic conductive film on the substrate after the initial and reliability (after the addition of the temperature of 85 캜 and the humidity of 85% RH for 250 hours) was observed using a metal microscope (trade name: MX50, manufactured by Olympus Corporation).

And evaluated according to the following criteria. The results after initial and reliability are shown in Table 1-1.

○: 0/10 (0 out of 10 samples) is observed with a microscope.

?: One-tenth of the sample was observed with a microscope (1 out of 10 samples).

×: More than 2/10 (more than 2 out of 10 samples) are observed with a microscope.

(Examples 2 to 15 and Comparative Examples 1 to 10)

Production of an anisotropic conductive film and production of a bonded body were carried out in the same manner as in Example 1, except that the kind and blending amount of the materials were changed as shown in Tables 1-1 to 1-5.

The same evaluation as in Example 1 was carried out. The results are shown in Tables 1-1 to 1-5.

[Table 1-1]

[Table 1-2]

[Table 1-3]

[Table 1-4]

[Table 1-5]

Polyester urethane A: UR4410, manufactured by TOYOBO CO., LTD. (Number average molecular weight: 10,000, glass transition temperature: 56 캜)

Polyester urethane A ': UR5537, manufactured by TOYOBO CO., LTD. (Number average molecular weight: 20,000, glass transition temperature: 34 캜)

Polyester urethane B: UR8200, manufactured by Toyobo Co. (number average molecular weight: 25,000, glass transition temperature: 73 캜)

Polyester urethane B ': UR4125, manufactured by Toyobo Co., Ltd. (number average molecular weight: 20,000, glass transition temperature: 67 캜)

Polyester urethane C: UR1350, manufactured by TOYOBO CO., LTD. (Number average molecular weight: 30,000, glass transition temperature: 46 DEG C)

Polyester urethane D: UR8400, manufactured by Toyobo Co. (number average molecular weight: 25,000, glass transition temperature: 106 占 폚)

Polyester urethane E: UR1700, manufactured by TOYOBO CO., LTD. (Number average molecular weight: 16,000, glass transition temperature: 92 DEG C)

Polyester urethane F: UR1400, manufactured by Toyo Boseki Co., Ltd. (number average molecular weight: 40,000, glass transition temperature: 83 占 폚)

Bifunctional acrylate: M-1600, manufactured by Toagosei Co., Ltd.

Trifunctional acrylate: M-315, manufactured by Toagosei Co., Ltd.

Initiator 1: Peroil L, manufactured by Nichiyu Co., Ltd.

Initiator 2: manufactured by Nippon BW, Nichiyu Co., Ltd.

Coupling agent: IM-1000, JX manufactured by Nikko Seiki Energy Co., Ltd.

Conductive particles: Au-Ni plated resin particles, trade name: Micropearl AU, average particle diameter 4 mu m, manufactured by Sekisui Chemical Co., Ltd.

Using the anisotropic conductive film containing two kinds of specific polyester urethane, a bonded body could be obtained at 140 캜 (low temperature) and 2 MPa (low pressure) for 5 seconds (short time).

With the anisotropic conductive film of the present invention, connection reliability is high, bonding strength is high, the degree of crushing of the conductive particles is good, and the connection is kept unobtainable from the substrate at a low temperature, a low pressure and a short time.

Claims (7)

A polyester urethane (A) having a number average molecular weight of 20,000 or less and a glass transition temperature of less than 60 占 폚,
A polyester urethane (B) having a number average molecular weight of 20,000 or more and 30,000 or less and a glass transition temperature of 60 占 폚 or more and 100 占 폚 or less,
A radical polymerizable material,
An anisotropic conductive film characterized by containing an organic peroxide. The method according to claim 1,
Wherein the mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) is 30:70 to 80:20. The method according to claim 1,
The ratio [Mn (B) / Mn (A)] of the number average molecular weight [Mn (A)] of the polyester urethane (A) to the number average molecular weight [Mn (B)] of the polyester urethane (B) Or less,
The total content of the polyester urethane (A) and the polyester urethane (B) is 18% by mass to 75% by mass. The method according to claim 1,
Wherein the radical polymerizable substance contains a bifunctional (meth) acrylate and a trifunctional (meth) acrylate,
(Meth) acrylate: trifunctional (meth) acrylate] in a weight ratio of the bifunctional (meth) acrylate to the trifunctional (meth) acrylate is from 30:70 to 80:20,
Wherein the total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate is 18% by mass to 75% by mass. The method according to claim 1,
An anisotropic conductive film containing an imidazole silane. A connection method for anisotropic conductive connection between a terminal of a substrate and a terminal of an electronic component,
An attaching step of attaching the anisotropic conductive film according to any one of claims 1 to 5 onto a terminal of the substrate;
A mounting step of placing the electronic component on the anisotropic conductive film,
And a heating and pressing step of heating and pressing the electronic component with a heating and pressing member,
Wherein the pressing in the heating and pressing step is 1 MPa to 3 MPa. A bonded body produced by using the connection method according to claim 6.