JP6374192B2 - Anisotropic conductive film, connection method, and joined body - Google Patents

Description

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

  An anisotropic conductive film electrically connects, for example, terminals of a flexible printed circuit (FPC) or IC (Integrated Circuit) chip and electrodes formed on a glass substrate of an LCD (Liquid Crystal Display) panel. It is used when various terminals are bonded together and electrically connected to each other.

  Conventionally, in connection with an anisotropic conductive film, if it is performed at 160 ° C. or higher, thermal damage may occur depending on the member, and if it is performed at 4 MPa or higher, physical damage may occur depending on the member. If it carries out above, there is a problem that production efficiency is not so good.

  Therefore, in recent years, in the connection using an anisotropic conductive film, there is an increasing demand for suppression of heat and physical damage to members and improvement of production efficiency. Therefore, in a low temperature of about 140 ° C., a low pressure of about 3 MPa, and a short time of about 5 seconds, the connection reliability is excellent, the adhesive strength is high, the degree of crushing of the conductive particles is good, and the anisotropy from the substrate There is a demand for connection with an anisotropic conductive film that does not lift the conductive film.

  As an adhesive for circuit connection, a technique for improving the adhesive force by using an adhesive having an acid equivalent of 5 KOHmg / g to 500 KOHmg / g has been proposed (for example, see Patent Document 1). However, in this proposed technique, circuit connection is performed at 4 MPa (high pressure) and 20 seconds (long time), so that there is a problem that physical damage is given to the member and the production efficiency is not good.

  A technique for circuit connection at a low pressure by making the space between the opposing electrodes narrower than the diameter of the conductive particles, so that the conductive particles are crushed by the opposing electrodes and ensuring conduction between the electrodes. Has been proposed (see, for example, Patent Document 2). However, in this proposed technique, circuit connection is performed at 170 ° C. (high temperature), so that there is a problem that the member is thermally damaged.

By using a radical curable adhesive composition containing a thermoplastic resin, a radical polymerizable compound and a radical polymerization initiator as an adhesive composition, it is possible to connect anisotropic conductive films in a short time. Techniques have been proposed (see, for example, Patent Document 3). However, in this proposed technique, since the connection by the anisotropic conductive film is performed at 160 ° C. (high temperature), there is a problem that the member is thermally damaged.

  In addition, by using an adhesive composition containing a thermoplastic resin, a radical polymerizable compound, a radical generator, and a silane coupling agent having a solubility parameter of 9.0 or more, it is strong against an inorganic substrate. A technique for obtaining adhesive strength has been proposed (see, for example, Patent Document 4). However, in this proposed technique, circuit connection is performed at 175 ° C. (high temperature) and 15 seconds (long time), so that there is a problem that the member is thermally damaged and the production efficiency is not good.

  Therefore, in these proposed techniques, the connection reliability is excellent, the adhesive strength is high, and the conductive particles have a low temperature of about 140 ° C., a low pressure of about 3 MPa, and a short time of about 5 seconds. There is a problem that it is not possible to realize connection using an anisotropic conductive film that is well crushed and does not lift from the substrate.

  Accordingly, an anisotropic conductive film that has excellent connection reliability, high adhesive strength, good crushing state of conductive particles, and can be connected without floating from the substrate at low temperature, low pressure, and in a short time. At present, there is a demand for a connection method and a joined body using an anisotropic conductive film.

JP 2007-169632 A JP2012-067211 International Publication No. 07/046189 Pamphlet JP 2007-177204 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention is an anisotropic conductive film that has excellent connection reliability, high adhesive strength, good crushing of conductive particles, and can be connected without floating from the substrate at low temperature, low pressure, and in a short time. It is another object of the present invention to provide a connection method using the anisotropic conductive film, and a joined body.

Means for solving the problems are as follows. That is,
<1> Polyester urethane (A) having a number average molecular weight of 20,000 or less and a glass transition temperature of less than 60 ° C .;
Polyester urethane (B) having a number average molecular weight of 20,000 to 30,000 and a glass transition temperature of 60 ° C. to 100 ° C .;
A radical polymerizable substance;
An anisotropic conductive film comprising an organic peroxide.
<2> The anisotropic conductive film according to <1>, wherein a 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) and the number average molecular weight [Mn (B)] of the polyester urethane (B) is 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. .
<4> The radical polymerizable substance contains a bifunctional (meth) acrylate and a trifunctional (meth) acrylate,
The mass ratio of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate [bifunctional (meth) acrylate: trifunctional (meth) acrylate] is 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. It is.
<5> The anisotropic conductive film according to any one of <1> to <4>, which contains imidazolesilane.
<6> A connection method for anisotropically conductively connecting 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 <1> to <5> on a terminal of the substrate;
A placing step of placing the electronic component on the anisotropic conductive film;
A heating and pressing step of heating and pressing the electronic component with a heating and pressing member,
The connection method according to claim 1, wherein the pressing in the heating and pressing step is 1 MPa to 3 MPa.
<7> A joined body produced using the connection method according to <6>.

  According to the present invention, the conventional problems can be solved and the object can be achieved, and the connection reliability is excellent at a low temperature, a low pressure, and in a short time, and the adhesive strength is high. And an anisotropic conductive film capable of being connected without rising from the substrate, a connection method using the anisotropic conductive film, and a joined body can be provided.

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

<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 more preferably 10,000 or more and 15,000. The following are particularly preferred: If the number average molecular weight of the polyester urethane (A) exceeds 20,000, the conductive particles cannot be sufficiently crushed and the connection becomes unstable.
As a glass transition temperature of the said polyester urethane (A), it is less than 60 degreeC, and 40 degreeC or more and less than 60 degreeC are preferable. When the glass transition temperature of the polyester urethane (A) is 60 ° C. or higher, the conductive particles cannot 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.

<Polyester urethane (B)>
The number average molecular weight of the polyester urethane (B) is from 20,000 to 30,000, preferably from 22,000 to 28,000. When the number average molecular weight of the polyester urethane (B) is less than 20,000, the connection reliability may not be excellent, and when it exceeds 30,000, the conductive particles cannot be sufficiently crushed and the connection is not good. It becomes stable.
As a glass transition temperature of the said polyester urethane (B), they are 60 degreeC or more and 100 degrees C or less, and 65 degreeC or more and 85 degrees C or less are preferable. When the glass transition temperature of the polyester urethane (B) is less than 60 ° C, the connection reliability is not excellent, and when it exceeds 100 ° C, the adhesiveness is not excellent.

  The number average molecular weights 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 for the calibration curve.

  The glass transition temperature of the said polyester urethane (A) and the said polyester urethane (B) can be calculated | required by differential scanning calorimetry (DSC), for example. In the DSC, for example, a 5 mg sample housed in an aluminum pan is used, and the temperature is increased from 20 ° C. to 150 ° C. at a temperature increase rate of 10 ° C./min.

In the anisotropic conductive film, the method for confirming that the polyester urethane (A) and the polyester urethane (B) are used in combination is not particularly limited and can be appropriately selected according to the purpose. The following methods are mentioned.
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).
In the measurement result, when two peaks (bimodality) are obtained, fractionation is performed based on the peaks to obtain two resin components. For each of the obtained two resin components, the number average molecular weight and the glass transition temperature are measured by the method described above. It should be noted that bimodality is also determined when two peaks are close and one is seen as the other shoulder.
Moreover, when the molecular weights of the polyester urethane (A) and the polyester urethane (B) are close, and two peaks are not clearly obtained in the HPLC measurement results, separation by a difference in solvent solubility is performed. Distinguishing between the polyester urethane (A) and the polyester urethane (B) by separating using the specific gravity difference, analyzing the bottom half of the first half and the latter half of the GPC chart. Can do.

The mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) is preferably 30:70 to 80:20, and more preferably 40:60 to 60:40. In the mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B), when the ratio of the polyester urethane (A) is less than 30:70, adhesive strength and connection reliability are obtained. It may not be excellent, and if it exceeds 80:20, the adhesive strength and 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 is, for example, a method of calculating from a blending amount, the polyester urethane (A) and the above The method of calculating | requiring from the mass of the said polyester urethane (A) and the said polyester urethane (B) fractionated in the confirmation method that the polyester urethane (B) is used together is mentioned.

  As the ratio [Mn (B) / Mn (A)] of the number average molecular weight [Mn (A)] of the polyester urethane (A) and the number average molecular weight [Mn (B)] of the polyester urethane (B) 1.0 or 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) and the number average molecular weight [Mn (B)] of the polyester urethane (B) is If it is less than 1.0, the connection reliability may not be excellent, and if it exceeds 3.0, the conductive particles may 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% by mass to 75% by mass, and more preferably 30% by mass to 65% by mass. When the total content of the polyester urethane (A) and the polyester urethane (B) is less than 18% by mass, adhesion may be insufficient. It may not be reliable.

<Radically polymerizable substances>
There is no restriction | limiting in particular as said radically polymerizable substance, According to the objective, it can select suitably, For example, monofunctional (meth) acrylate, bifunctional (meth) acrylate, trifunctional (meth) acrylate, tetrafunctional ( Examples include meth) acrylate, pentafunctional (meth) acrylate, and hexafunctional (meth) acrylate.
The (meth) acrylate in the present invention means “at least one of acrylate and methacrylate”.

There is no restriction | limiting in particular as said monofunctional (meth) acrylate, According to the objective, it can select suitably, For example, polyethyleneglycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate Etc.
The bifunctional (meth) acrylate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 1,4-butanediol di (meth) acrylate and 1,6-hexanediol di (meth). Acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, ethylene glycol di (meth) acrylate, isocyanuric acid ethylene oxide modified di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) Acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, etc. It is below.
The trifunctional (meth) acrylate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, and propionic acid-modified diacid Examples include pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, and tris (acryloyloxyethyl) isocyanurate.
The tetrafunctional (meth) acrylate is not particularly limited and may be appropriately selected depending on the intended 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 depending on the intended purpose. Examples thereof include dipentaerythritol penta (meth) acrylate and propionic acid-modified dipentaerythritol penta (meth) acrylate. Can be mentioned.
The hexafunctional (meth) acrylate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. It is done.
The radically polymerizable substance may be used alone or in combination of two or more thereof, may be appropriately synthesized, or may be a commercially available product.

The total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate in the anisotropic conductive film is preferably 18% by mass to 75% by mass, more preferably 30% by mass to 65% by mass. preferable. In the anisotropic conductive film, the total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate is less than 18 wt%, resulting in hardness of shortage, excellent connection reliability In some cases, if it exceeds 75% by mass, adhesion may be insufficient.

<Organic peroxide>
The organic peroxide is not particularly limited and may be appropriately selected depending on the intended purpose. For example, lauroyl peroxide, butyl peroxide, benzyl peroxide, dilauroyl peroxide, dibutyl peroxide, peroxide Examples include carbonate and benzoyl peroxide. These may be used individually by 1 type, may use 2 or more types together, may synthesize | combine suitably, and may be a commercial item.

  There is no restriction | limiting in particular as content of the said organic peroxide in the said anisotropic conductive film, Although it can select suitably according to the objective, It is preferable that it is 0.1 mass%-5 mass%. .

<Other ingredients>
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, silanes such as imidazole series, epoxy series, methacryloxy series, amino series, vinyl series, mercapto sulfide series, ureido series, etc. Examples include coupling agents, inorganic fillers such as silica, talc, titanium oxide, calcium carbonate and magnesium oxide, softeners such as thermoplastic resins and rubber components, etc., but imidazole silane in terms of improving adhesion to glass. Is preferred.

(Connection method)
The connection method of the present invention includes a pasting step, a placing step, and a heating and pressing step, and further includes other steps as necessary.
The connection method is a connection method in which the terminals of the substrate and the terminals of the electronic component are anisotropically conductively connected.

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

<< Board >>
There is no restriction | limiting in particular as said board | substrate, According to the objective, it can select suitably, For example, a glass substrate, a plastic substrate, a ceramic substrate, a flexible printed circuit board etc. are mentioned.

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

<< Electronic parts >>
The electronic component is not particularly limited as long as it is an electronic component having a terminal that is an object of anisotropic conductive connection, and can be appropriately selected according to the purpose. For example, an IC chip, a TAB tape, A liquid crystal panel, a flexible substrate, etc. are mentioned.
Examples of the IC chip include a liquid crystal screen control IC chip in a flat panel display (FPD).

<Heat pressing process>
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.
There is no restriction | limiting in particular as said heating press member, According to the objective, it can select suitably, For example, the press member etc. which have a heating mechanism are mentioned. There is no restriction | limiting in particular as a press member which has the said heating mechanism, According to the objective, it can select suitably, For example, a heat tool etc. are mentioned.
There is no restriction | limiting in particular as the temperature of the said heating, Although it can select suitably according to the objective, 130 to 150 degreeC is preferable and 130 to 140 degreeC is more preferable.
The pressing pressure is 1 MPa to 5 MPa, preferably 1 MPa to 3 MPa.
There is no restriction | limiting in particular as time of the said heating and a press, Although it can select suitably according to the objective, 2 seconds-5 seconds are preferable.

(Joint)
The joined body of the present invention is manufactured by the connection method of the present invention.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Preparation of anisotropic conductive film>
Polyester urethane (A) (trade name: UR4410, manufactured by Toyobo Co., Ltd., number average molecular weight: 10,000, glass transition temperature: 56 ° C.) 40 parts by mass, polyester urethane (B) (trade name: UR8200, Toyobo Co., Ltd.) Manufactured, number average molecular weight: 25,000, glass transition temperature: 73 ° C. 10 parts by mass, bifunctional acrylate (trade name: M-1600, manufactured by Toagosei Co., Ltd., urethane acrylate) 25 parts by mass, trifunctional acrylate (Trade name: M-315, manufactured by Toagosei Co., Ltd., isocyanuric acid EO-modified di- and triacrylate) 25 parts by mass, initiator 1 (trade name: Parroyl L, manufactured by NOF Corporation, aliphatic diacyl peroxide ) 2 parts by mass, the initiator 2 (trade name: NYPER BW, NOF Corporation, benzoyl peroxide) 2 parts by mass, 1.5 parts by mass of a pulling agent (trade name: IM-1000, manufactured by JX Nippon Oil & Energy Corporation, imidazole silane) and conductive particles (Au—Ni plated resin particles, trade name: Micropearl AU, average grain) An anisotropic conductive composition containing 2 parts by mass of 4 μm in diameter and Sekisui Chemical Co., Ltd.) was obtained.
The obtained anisotropic conductive composition was coated on release PET (polyethylene terephthalate, size 250 mm, average thickness 50 μm), dried at 80 ° C., and anisotropy having an average thickness of 25 μm on the release PET. A conductive film was obtained.

<Manufacture of joined body>
The joined body was manufactured by the following method.
As an electronic component, a glass substrate on which an ITO thin film was formed was used.
A flexible printed circuit board (copper wiring: line / space = 100 μm / 100 μm) was used as the substrate.
The anisotropic conductive film (film width 2.0 mm) was disposed on the substrate. Subsequently, the electronic component was placed on the anisotropic conductive film. Subsequently, the electronic component was heated and pressed under conditions of 140 ° C., 2 MPa, and 5 seconds to obtain a joined body.

<Measurement of conduction resistance>
About each joined body, the conduction | electrical_connection resistance value after an initial stage and reliability (temperature 85 degreeC, humidity 85% RH, after 250hr injection | throwing-in) was measured using the digital multimeter (34401A, Agilent Technologies, Inc.). As a measuring method, a 4-terminal method was used, and a current of 1 mA was passed.
Evaluation was made according to the following criteria. The results are shown in Table 1-1.
○: Less than 2Ω △: 2Ω or more and less than 10Ω ×: 10Ω or more

<Measurement of adhesive strength>
A tensile tester (product number: RTC1201, manufactured by AND) is used for the adhesion strength of the glass substrate and COF (Chip On Film) bonded body at the initial stage and after reliability (temperature 85 ° C., humidity 85% RH, after 250 hours). And measured. The adhesive strength was measured when the measurement speed was 50 mm / min and the COF was pulled up in the 90 degree direction.
Evaluation was made according to the following criteria. Table 1-1 shows the initial and post-reliability results.
◎: 10 N / cm or more ○: 5 N / cm or more and less than 10 N / cm Δ: 3 N / cm or more and less than 5 N / cm ×: less than 3 N / cm

<Condition of conductive particles>
About the electroconductive particle contained in an anisotropic conductive film, the crushing condition of the said electroconductive particle after conjugate | zygote preparation was observed using the metal microscope (brand name: MX50, Olympus company make). When obvious deformation of the conductive particles was observed, it was determined that the conductive particles were crushed.
Evaluation was made according to the following criteria. The results are shown in Table 1-1.
○: Conductive particles are crushed ×: Conductive particles are not crushed

<Float resistance>
Using a metal microscope (trade name: MX50, manufactured by Olympus Corporation), the floating resistance of the anisotropic conductive film to the substrate after initial and reliability (temperature 85 ° C., humidity 85% RH, after 250 hours) was observed. .
Evaluation was made according to the following criteria. Table 1-1 shows the initial and post-reliability results.
○: 0/10 floating in a microscope (in 10 samples)
Δ: Floating 1/10 with a microscope
X: Floating 2 or more with a microscope / 10

(Examples 2-15, Comparative Examples 1-10)
In Example 1, except that the kind of material and the blending amount were changed as shown in Table 1-1 to Table 1-5, in the same manner as in Example 1, production of an anisotropic conductive film, and joined body Was manufactured.
Moreover, the same evaluation as Example 1 was performed. The results are shown in Table 1-1 to Table 1-5.

ポリエステルウレタンＡ ：ＵＲ４４１０、東洋紡株式会社製（数平均分子量；１０，０００、ガラス転移温度；５６℃）
ポリエステルウレタンＡ’ ：ＵＲ５５３７、東洋紡株式会社製（数平均分子量；２０，０００、ガラス転移温度；３４℃）
ポリエステルウレタンＢ ：ＵＲ８２００、東洋紡株式会社製（数平均分子量；２５，０００、ガラス転移温度；７３℃）
ポリエステルウレタンＢ’ ：ＵＲ４１２５、東洋紡株式会社製（数平均分子量；２０，０００、ガラス転移温度；６７℃）
ポリエステルウレタンＣ ：ＵＲ１３５０、東洋紡株式会社製（数平均分子量；３０，０００、ガラス転移温度；４６℃）
ポリエステルウレタンＤ ：ＵＲ８４００、東洋紡株式会社製（数平均分子量；２５，０００、ガラス転移温度；１０６℃）
ポリエステルウレタンＥ ：ＵＲ１７００、東洋紡株式会社製（数平均分子量；１６，０００、ガラス転移温度；９２℃）
ポリエステルウレタンＦ ：ＵＲ１４００、東洋紡株式会社製（数平均分子量；４０，０００、ガラス転移温度；８３℃）
２官能アクリレート ：Ｍ−１６００、東亞合成株式会社製
３官能アクリレート ：Ｍ−３１５、東亞合成株式会社製
開始剤１ ：パーロイルＬ、日油株式会社製
開始剤２ ：ナイパーＢＷ、日油株式会社製
カップリング剤 ：ＩＭ−１０００、ＪＸ日鉱日石エネルギー株式会社製
導電性粒子 ：Ａｕ−Ｎｉめっき樹脂粒子、商品名：ミクロパールＡＵ、平均粒径４μｍ、積水化学工業株式会社製

Polyester urethane A: UR4410, manufactured by Toyobo Co., Ltd. (number average molecular weight; 10,000, glass transition temperature; 56 ° C.)
Polyester urethane A ′: UR5537, manufactured by Toyobo Co., Ltd. (number average molecular weight: 20,000, glass transition temperature: 34 ° C.)
Polyester urethane B: UR8200, manufactured by Toyobo Co., Ltd. (number average molecular weight; 25,000, glass transition temperature; 73 ° C.)
Polyester urethane B ′: UR4125, manufactured by Toyobo Co., Ltd. (number average molecular weight: 20,000, glass transition temperature: 67 ° C.)
Polyester urethane C: UR1350, manufactured by Toyobo Co., Ltd. (number average molecular weight: 30,000, glass transition temperature: 46 ° C.)
Polyester urethane D: UR8400, manufactured by Toyobo Co., Ltd. (number average molecular weight; 25,000, glass transition temperature; 106 ° C.)
Polyester urethane E: UR1700, manufactured by Toyobo Co., Ltd. (number average molecular weight; 16,000, glass transition temperature; 92 ° C.)
Polyester urethane F: UR1400, manufactured by Toyobo Co., Ltd. (number average molecular weight; 40,000, glass transition temperature; 83 ° C.)
Bifunctional acrylate: M-1600, manufactured by Toagosei Co., Ltd. Trifunctional acrylate: M-315, manufactured by Toagosei Co., Ltd. Initiator 1: Parroyl L, manufactured by NOF CORPORATION Initiator 2: NIPER BW, manufactured by NOF Corporation Coupling agent: IM-1000, manufactured by JX Nippon Oil & Energy Corporation, conductive particles: Au-Ni plated resin particles, trade name: Micropearl AU, average particle size 4 μm, manufactured by Sekisui Chemical Co., Ltd.

  By using an anisotropic conductive film containing two kinds of specific polyester urethanes, a joined body could be obtained at 140 ° C. (low temperature), 2 MPa (low pressure), and 5 seconds (short time).

  With the anisotropic conductive film of the present invention, it is possible to achieve a connection that is excellent in connection reliability, has high adhesive strength, has a good degree of crushing of conductive particles, and does not float from the substrate at low temperature, low pressure, and in a short time. .

Claims (8)

Polyester urethane (A) having a number average molecular weight of 20,000 or less and a glass transition temperature of less than 60 ° C .;
Polyester urethane (B) having a number average molecular weight of 20,000 to 30,000 and a glass transition temperature of 60 ° C. to 100 ° C .;
A radical polymerizable substance;
Containing organic peroxides ,
The ratio [Mn (B) / Mn (A)] of the number average molecular weight [Mn (A)] of the polyester urethane (A) and the number average molecular weight [Mn (B)] of the polyester urethane (B) is 2.0 or 3.0 anisotropic conductive film characterized in der Rukoto below. The anisotropic conductive film according to claim 1, wherein the total content of the polyester urethane (A) and the polyester urethane (B) is 18% by mass to 75% by mass. Polyester urethane (A) having a number average molecular weight of 20,000 or less and a glass transition temperature of less than 60 ° C .;
Polyester urethane (B) having a number average molecular weight of 20,000 to 30,000 and a glass transition temperature of 60 ° C. to 100 ° C .;
A radical polymerizable substance;
Containing organic peroxides,
The radical polymerizable substance contains a bifunctional (meth) acrylate and a trifunctional (meth) acrylate,
The mass ratio of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate [bifunctional (meth) acrylate: trifunctional (meth) acrylate] is 30:70 to 80:20, An anisotropic conductive film. The anisotropic conductive film according to claim 3, wherein a total content of the bifunctional (meth) acrylate and the trifunctional (meth) acrylate is 18% by mass to 75% by mass. The anisotropic conductive film according to any one of claims 1 to 4, wherein a mass ratio (A: B) of the polyester urethane (A) and the polyester urethane (B) is 30:70 to 80:20. The anisotropic conductive film according to claim 1, which contains imidazole silane. A connection method for anisotropic conductive connection between a terminal of a substrate and a terminal of an electronic component,
A sticking step of attaching the anisotropic conductive film according to any one of claims 1 to 6 on a terminal of the substrate;
A placing step of placing the electronic component on the anisotropic conductive film;
A heating and pressing step of heating and pressing the electronic component with a heating and pressing member,
The connection method, wherein the pressing in the heating and pressing step is 1 MPa to 3 MPa. A joined body in which a substrate and an electronic component are anisotropically conductively connected via a cured product of the anisotropic conductive film according to any one of claims 1 to 6.