HK1189389A1

HK1189389A1 - Anisotropic conductive connection material, film laminate, connection method, and connection structure

Info

Publication number: HK1189389A1
Application number: HK14102534.3A
Authority: HK
Inventors: 阿久津恭志
Original assignee: Dexerials Corporation
Priority date: 2011-05-12
Filing date: 2012-05-11
Publication date: 2014-06-06
Also published as: WO2012153849A1; TWI539470B; KR20140035391A; CN103502379B; TW201301300A; KR101973823B1; JP5816456B2; JP2011204685A; CN103502379A

Abstract

To improve connection strength and conduction reliability. This anisotropic conductive connection material is obtained by dispersing conductive particles (5) in an adhesive (4). The adhesive (4) contains a film-forming material, an acrylic resin, an organic peroxide and an amine compound, and the amine compound is a cyclic tertiary amine compound.

Description

Anisotropic conductive connecting material, film laminate, connecting method, and connecting structure

Technical Field

The present invention relates to an anisotropic conductive connecting material used when mounting electronic components such as a flexible printed wiring board and a semiconductor element on a wiring board, a film laminate in which an anisotropic conductive connecting layer is formed on a release film, a connecting method for connecting an electronic component and a wiring board with an anisotropic conductive connecting layer, and a connection structure obtained by the connecting method.

This application claims priority based on japanese patent application No. 2011-107457 filed in japan on 12/5/2011, which is incorporated herein by reference.

Background

In recent years, the liquid crystal display screen has been becoming larger, as represented by a large-screen television device.

Under such circumstances, when an electronic component and a wiring board are connected by an anisotropic conductive film, low-temperature curing for suppressing the influence of thermal stress and shortening of the tact time for improving productivity are required. A low temperature, short duration of 160-4 sec has now been achieved. However, a low temperature of 140 ℃ to 4sec is also required.

In order to satisfy such a demand, connection between an electronic component and a wiring board is performed using an acrylic anisotropic conductive film that connects and conducts the wiring board and the electronic component by radical polymerization of an acrylate with an organic peroxide.

The acrylic anisotropic conductive film mainly contains a radical polymerizable substance (meth) acrylate as a curing component, a polymer material as a film component, an organic peroxide as a curing catalyst, and conductive particles. For example, there is an anisotropic conductive film containing an epoxy acrylate oligomer as a radical polymerizable material, a bisimidazole group which generates an active radical by light irradiation, and conductive particles (see, for example, patent document 1). Such acrylic anisotropic conductive films have a problem that, unlike epoxy anisotropic conductive films, they react with each other, and thus, a hydroxyl group capable of obtaining adhesiveness is not generated in the reaction process, thereby reducing adhesiveness.

Therefore, in the acrylic anisotropic conductive film, an acrylic ester or urethane acrylate containing a phosphoric group is added as a curing component to improve the adhesive strength (for example, see patent document 2).

However, when an acrylic acid ester containing a phosphoric acid group is added, adhesion to polyimide, metal wiring, and the like is improved, but impurities or phosphoric acid generated by decomposition corrode the wiring.

Therefore, only a small amount of acrylic ester containing phosphoric groups can be added to the acrylic anisotropic conductive film, and a sufficient effect cannot be obtained in terms of adhesion and conductivity between the electronic component and the wiring board.

In addition, when urethane acrylate is added, urethane acrylate having a large molecular weight is often used in the usual urethane acrylate in consideration of stress relaxation property, but if the molecular weight is large, the viscosity becomes high.

As shown in fig. 5(a), an anisotropic conductive film 42 is generally bonded to a wiring board 41 on which terminals 40 are formed, and electronic components 43 are mounted on the anisotropic conductive film 42. Then, as shown in fig. 5(B), the electronic component 43 is heated and pressed to cure the anisotropic conductive film 42, and the terminals 40 of the wiring board 41 and the terminals 45 of the electronic component 43 can be electrically connected by the conductive particles 44.

On the other hand, in the anisotropic conductive film 46 to which urethane acrylate is added, as shown in fig. 6, the adhesion and the conductivity between the wiring board 41 and the electronic component 43 are insufficient. As shown in fig. 6(a), when the anisotropic conductive film 46 is bonded to the wiring board 41 on which the terminals 40 are formed, the electronic component 43 is mounted on the anisotropic conductive film 46, and the electronic component 43 is heated and pressed against the wiring board 41, there is a problem of pre-curing in which the adhesive of the anisotropic conductive film 46 is solidified before the electrical connection is formed between the terminals 40 of the wiring board 41 and the terminals 45 of the electronic component 43. Thus, the adhesive cannot be excluded from between the terminals 40 of the wiring board 41 and the terminals 45 of the electronic component 43, and conduction between the terminals cannot be obtained. Therefore, when urethane acrylate having a small molecular weight is used, the adhesion between the wiring board 41 and the electronic component 43 cannot be improved, and a sufficient effect cannot be obtained.

Therefore, a method for connecting a wiring board and an electronic component with an acrylic anisotropic conductive film capable of realizing low-temperature curing and improvement in productivity is required to be a method capable of connecting with high reliability in connection strength and conduction.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2009-283985

Patent document 2: japanese patent laid-open No. 2003-313533.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to provide an anisotropic conductive connecting material capable of improving connection strength and conduction reliability in connection between a substrate and an electronic component, a film laminate in which an anisotropic conductive connecting layer is formed on a release film, a connection method for connecting an electronic component and a wiring board with an anisotropic conductive connecting layer, and a connection structure obtained by the connection method.

Means for solving the problems

The anisotropic conductive connecting material of the present invention for achieving the above object is characterized in that the anisotropic conductive connecting material is obtained by dispersing conductive particles in an adhesive, the adhesive contains a film-forming material, an acrylic resin, an organic peroxide and an amine compound, and the amine compound is a cyclic tertiary amine compound.

The film laminate according to the present invention for achieving the above object is characterized in that an anisotropic conductive connection layer in which conductive particles are dispersed in an adhesive is formed on a release film, the adhesive contains a film-forming material, an acrylic resin, an organic peroxide, and an amine compound, and the amine compound is a cyclic tertiary amine compound.

A connection method according to the present invention for achieving the above object is a method for connecting a terminal of a substrate and a terminal of an electronic component with an anisotropic conductive connection layer, the method including: an adhesive layer forming step of forming an anisotropic conductive connection layer in which conductive particles are dispersed in an adhesive on a terminal of a substrate; a mounting step of mounting an electronic component on a substrate through an anisotropic conductive connection layer so that a terminal of the electronic component and a terminal of the substrate face each other; and a connection step of heating and pressing the electronic component from the upper surface of the electronic component by a pressing head, pressing the mounted electronic component against the substrate, and electrically connecting the terminals of the substrate and the terminals of the electronic component via the conductive particles of the anisotropic conductive connection layer; the adhesive for the anisotropic conductive connection layer contains a film-forming material, an acrylic resin, an organic peroxide, and an amine compound, and the amine compound is a cyclic tertiary amine compound.

The connection structure of the present invention for achieving the above object is a connection structure for electrically connecting a substrate and an electronic component by allowing an anisotropic conductive connection layer to be present between terminals of the substrate and terminals of the electronic component, wherein the anisotropic conductive connection layer is formed by dispersing conductive particles in an adhesive, the adhesive contains a film-forming material, an acrylic resin, an organic peroxide and an amine compound, and the amine compound is a cyclic tertiary amine compound.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, by containing a film-forming material, an acrylic resin, an organic peroxide, and an amine compound, and further containing a cyclic tertiary amine compound as the amine compound, in the adhesive of the anisotropic conductive connecting material or the anisotropic conductive connecting layer, the adhesive strength can be improved without increasing the on-resistance.

Drawings

Fig. 1 is a sectional view of a film laminate to which the present invention is applied.

Fig. 2 is a cross-sectional view of a connection structure in which a substrate and an IC chip are connected by an anisotropic conductive film.

FIG. 3 is a perspective view of a connection structure used for measuring the on-resistance of the example.

FIG. 4 is a perspective view of a connection structure used in an adhesion strength test of an example.

Fig. 5 is a cross-sectional view illustrating a method of connecting an electronic component and a wiring board by a general acrylic anisotropic conductive film, wherein (a) is a cross-sectional view showing a state where the electronic component is mounted on the anisotropic conductive film attached to the wiring board and heated and pressed, and (B) is a cross-sectional view showing a state where the wiring board and the electronic component are bonded by the anisotropic conductive film.

Fig. 6 is a cross-sectional view illustrating a method of connecting an electronic component and a wiring board by an anisotropic conductive film containing urethane acrylate, wherein (a) is a cross-sectional view showing a state where the electronic component is mounted on the anisotropic conductive film attached to the wiring board and heated and pressed, and (B) is a cross-sectional view showing a state where the wiring board and the electronic component are not electrically connected by the anisotropic conductive film.

Detailed Description

Embodiments of the anisotropic conductive connecting material, the film laminate, the connecting method, and the connecting structure used in the present invention (hereinafter referred to as "the present embodiment") will be described in detail in the following order with reference to the drawings.

1. Anisotropic conductive connecting material ･ film laminate

2. Connection structure ･ connection method

3. Examples are given.

< 1. Anisotropic conductive connecting Material ･ film laminate >

The anisotropic conductive connecting material is present between, for example, a terminal of the substrate and a terminal of the electronic component, and connects the substrate and the electronic component to conduct electricity. Such an anisotropic conductive connecting material is a film-like anisotropic conductive adhesive film containing conductive particles or a paste-like anisotropic conductive adhesive paste. In the present application, the anisotropic conductive adhesive film or the anisotropic conductive adhesive paste is defined as "anisotropic conductive connecting material". The following description will be given by taking an anisotropic conductive adhesive film as an example.

As shown in fig. 1, the film laminate 1 is generally a laminate in which an anisotropic conductive film 3 as an anisotropic conductive connection layer is laminated on a release film 2 as a base material.

The release film 2 is formed by coating a release agent such as silicone on PET (polyethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methyl-1-pentene (Poly-4-methyl-pentane-1)), PTFE (Polytetrafluoroethylene), or the like. The anisotropic conductive film 3 maintains its shape by the release film 2.

The anisotropic conductive film 3 is a film in which conductive particles 5 are dispersed in an adhesive (binder) 4, and the adhesive 4 contains at least a film forming material, an acrylic resin as a curing component, an organic peroxide as a curing agent, and an amine compound. The anisotropic conductive film 3 is formed in a film shape on the release film 2.

The film-forming resin is preferably a resin having an average molecular weight of about 10000 to 80000. Examples of the film-forming resin include various resins such as phenoxy resin, polyester urethane resin, polyester resin, polyurethane resin, acrylic resin, polyimide resin, and butyral resin. Among them, phenoxy resins are particularly preferable from the viewpoints of film formation state, connection reliability, and the like. The content of the film-forming resin is usually 30 to 80 parts by mass, preferably 40 to 70 parts by mass, per 100 parts by mass of the adhesive 4.

The curing component is a radical polymerizable resin, and an acrylic resin is used as the thermosetting resin. The acrylic resin is not particularly limited, and an acrylic compound, a liquid acrylate, and the like may be appropriately selected according to the purpose. Examples thereof may include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy-1, 3-diacryloyloxypropane, 2-bis [4- (acryloyloxymethyl) phenyl ] propane, 2-bis [4- (acryloyloxyethoxy) phenyl ] propane, dicyclopentenyl acrylate, tricyclodecane acrylate, tris (acryloyloxyethyl) isocyanurate, urethane acrylate and epoxy acrylate. In addition, compounds in which an acrylate is replaced with a methacrylate may also be used.

The curing component may be used alone or in combination of two or more. The content of the curing component is usually 10 to 60 parts by mass, preferably 20 to 50 parts by mass, per 100 parts by mass of the adhesive 4.

The adhesive 4 does not contain an epoxy resin as a curing component. This is because the adhesive 4 contains an amine compound to improve the adhesive strength as described below, and therefore, if an epoxy resin is contained, the epoxy group reacts and the viscosity increases, so that the substrate and the electronic component cannot be normally connected, the adhesive strength decreases, and the on-resistance increases.

As the curing agent, an organic peroxide as a radical polymerization initiator is used. Examples of the organic peroxide include lauroyl peroxide, butyl peroxide, benzyl peroxide, dilauroyl peroxide, dibutyl peroxide, benzyl peroxide, dicarbonate peroxide, and benzoyl peroxide. The content of the curing agent is usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of the adhesive 4.

The amine compound improves the adhesion of the adhesive 4. As the amine compound, an amine compound which is not modified with a silanol group, a vinyl group, or the like is used. Specifically, the amine compound is a cyclic tertiary amine compound, and examples thereof include an imidazole compound. The cyclic tertiary amine compound is preferably an imidazole compound, particularly preferably an imidazole compound having a cyano group, and in the case of an imidazole compound having a cyano group, the polarity is increased, and therefore the adhesive strength can be further improved. The amount of the amine compound to be blended is preferably 0.1 to 5 parts by mass with respect to 30 parts by mass of the acrylic resin, and when it is less than 0.1 part by mass, the adhesive strength of the anisotropic conductive film 3 cannot be sufficiently improved, while when it is more than 5 parts by mass, the connection reliability is lowered. When an imidazole compound is used as the amine compound, the content of the imidazole compound is preferably 0.5 to 5 parts by mass relative to 30 parts by mass of the acrylic resin, because the adhesive strength can be further improved.

It can be said that the addition of the amine compound to the adhesive 4 formed as described above generally improves the metal adhesion due to its polarity, but does not contain a material that initiates polymerization by the action of the amine compound, so that steric hindrance after the reaction is less likely to occur, and the amine compound can be effectively used, thereby improving the adhesion of the anisotropic conductive film 1.

In addition, when an amine compound is used as a catalyst in the adhesive 4, it can be used without affecting the product life of the anisotropic conductive film 3 even when 2-methylimidazole is used, which has a high reactivity, undergoes a curing reaction, and thus affects the storage stability of the adhesive 4 before use, or has a shortened product life.

The adhesive 4 may contain a silane coupling agent. The silane coupling agent is not particularly limited, and examples thereof include amino group-based, mercapto group ･ thioether-based, and urea-based. By adding the silane coupling agent, the adhesiveness at the interface between the organic material and the inorganic material can be improved.

The conductive particles 5 contained in the adhesive 4 may be any known conductive particles used for the anisotropic conductive film 3. Examples of the conductive particles 5 include particles of various metals or metal alloys such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, and gold, conductive particles obtained by coating a metal on the surface of particles of metal oxide, carbon, graphite, glass, ceramic, and plastic, and conductive particles obtained by further coating an insulating film on the surface of these particles. AS the conductive particles 5, conductive particles obtained by coating the surfaces of resin particles with a metal may be used, and examples of the resin particles include particles of epoxy resin, phenol resin, acrylic resin, acrylonitrile ･ styrene (AS) resin, benzoguanamine resin, divinylbenzene-based resin, styrene-based resin, and the like.

From the viewpoint of connection reliability, the average particle diameter of the conductive particles 5 is preferably 1 to 20 μm, and more preferably 2 to 10 μm. In addition, from the viewpoint of connection reliability and insulation reliability, the average particle density of the conductive particles 5 in the adhesive 4 is preferably 1000 to 50000 particles/mm²More preferably 3000 to 30000 pieces/mm²。

The film laminate 1 formed by such a constitution can be manufactured by the following method: the adhesive 4 is dissolved in a solvent such as toluene or ethyl acetate to prepare an adhesive solution in which conductive particles 5 are dispersed, the adhesive solution is applied to a release film 2 having releasability to a desired thickness, and the solvent is dried and removed to form an anisotropic conductive film 3.

The Film laminate 1 is not limited to the configuration in which the anisotropic Conductive Film 3 is formed on the release Film 2, and an insulating resin layer (NCF: insulating Film) layer) composed only of the adhesive 4 may be laminated on the anisotropic Conductive Film 3.

The film laminate 1 may be configured such that a release film is provided also on the opposite surface side of the anisotropic conductive film 3 from the surface on which the release film 2 is laminated.

The anisotropic conductive film 3 of the film laminate 1 formed in the above-described configuration is a radical-based anisotropic conductive film, contains a phenoxy resin, a urethane resin, or the like as a film-forming resin, an acrylic resin as a curing component, an organic peroxide as a radical polymerization initiator, and an amine compound that improves the adhesive strength of the adhesive 4, and thus can obtain high adhesive strength without increasing the electrical resistance.

In the anisotropic conductive film 3 of the film laminate 1, the adhesive 4 does not contain an epoxy resin that is anionically polymerized by an amine compound such as an imidazole compound, and an amine compound is not used as a radical polymerization initiator, and therefore, the adhesive 4 can be improved and the effect of the amine compound can be exerted.

<2 > connection Structure ･ connection method >

Next, a connection method for connecting and connecting terminals of a substrate and terminals of an electronic component by using the anisotropic conductive film 3 and a connection structure formed by the method will be described.

The connection structure 10 shown in fig. 2 is a connection structure in which a rigid wiring board 11 as a substrate and an IC chip 12 as an electronic component are mechanically and electrically connected and fixed by an anisotropic conductive film 3, for example. In this connection structure 10, the terminals 13 of the rigid wiring board 11 and the terminals 14 of the IC chip 12 are electrically connected by the conductive particles 5.

The method for manufacturing the connection structure 10 includes: an adhesive layer forming step of attaching the anisotropic conductive film 3 as an anisotropic conductive connection layer to the terminal 13 of the rigid wiring board 11; a mounting step of mounting the IC chip 12 on the rigid wiring board 11 with the terminal 14 of the IC chip 12 facing the terminal 13 of the rigid wiring board 11 via the anisotropic conductive film 3; and a connection step of heating and pressing the IC chip 12 from the upper surface of the IC chip 12 by a pressing head, heating and pressing the loaded IC chip 12 against the rigid wiring board 11, and electrically connecting the terminals 13 of the rigid wiring board 11 and the terminals 14 of the IC chip 12 via the conductive particles 5 of the anisotropic conductive film 3.

First, in the adhesive layer forming step, the anisotropic conductive film 3 of the film laminate 1 is placed at a position on the rigid wiring board 11 where the terminals 13 are connected to the terminals 14 of the IC chip 12, and the peeling film 2 is peeled off and removed to leave only the anisotropic conductive film 3, and then the anisotropic conductive film 3 is attached to the terminals 13. The pasting is performed at a temperature at which the thermosetting resin component contained in the anisotropic conductive film 3 is not cured, and is heated at a temperature of about 70 to 100 ℃ for about 0.5 to 2 seconds, for example, while being slightly pressurized. Thereby, the anisotropic conductive film 3 is positioned and fixed on the terminals 13 of the rigid wiring board 11.

Next, a mounting step of mounting the IC chip 12 on the anisotropic conductive film 3 is performed. In the mounting step, the alignment state of the anisotropic conductive film 3 is checked, and when no misalignment or the like occurs, the IC chip 12 is mounted on the rigid wiring board 11 via the anisotropic conductive film 3 such that the terminals 14 of the IC chip 12 are positioned on the anisotropic conductive film 3 and the terminals 13 of the rigid wiring board 11 face the terminals 14 of the IC chip 12.

Next, a connection step of mechanically and electrically connecting the rigid wiring board 11 and the IC chip 12 is performed. In the connection step, the IC chip 12 is pressed against the rigid wiring board 11 from above the IC chip 12 by a pressing head capable of heating and pressing, the anisotropic conductive film 3 is cured, the terminals 13 of the rigid wiring board 11 and the terminals 14 of the IC chip 12 are electrically connected by the conductive particles 5, and the rigid wiring board 1 and the IC chip 12 are mechanically connected by the anisotropic conductive film 3.

The conditions of the connection process are: the heating temperature is a temperature equal to or higher than the curing temperature of the thermosetting resin contained in the anisotropic conductive film 3, and the pressure capable of sandwiching the conductive particles 5 is applied by excluding the adhesive 4 from between the terminals 13 and 14. Thereby, the rigid board 11 and the IC chip 12 are electrically and mechanically connected through the anisotropic conductive film 3. Specific conditions of the temperature and the pressure include a temperature of about 130 to 150 ℃ and a pressure of about 1 to 100 MPa.

The connection structure 10 produced as described above contains a phenoxy resin, a urethane resin, or the like as a film-forming resin in the anisotropic conductive film 3, an acrylic resin as a curing component, an organic peroxide as a radical polymerization initiator, and an amine compound that improves the adhesion of the adhesive 4, and therefore not only is the adhesive strength of the anisotropic conductive film 3 high, but also the mechanical connection strength of the rigid wiring board 11 and the IC chip 12 high, and also the electrical connection strength of the terminals 13 of the rigid substrate 11 and the terminals 14 of the IC chip 12 high.

In this connection structure 10, since the anisotropic conductive film 3 does not contain an epoxy resin, the anisotropic conductive film 13 does not increase in viscosity, and a connection failure between the rigid wiring board 11 and the IC chip 12 can be prevented. Therefore, in the connection structure 10, the rigid wiring board 11 and the IC chip 12 have high connection strength and high conduction reliability.

The substrate of the connection structure 10 is not limited to the rigid wiring board 11, and may be any insulating substrate having terminals, such as a glass substrate provided with terminals, a plastic substrate, and a glass-reinforced epoxy substrate.

The electronic component is not limited to the IC chip 12, and may be another electronic component. Examples thereof include semiconductor elements such as semiconductor chips other than IC chips such as LSI (Large Scale Integration) chips and Chip capacitors, Flexible printed circuit boards (FPCs), and semiconductor mounting materials for liquid crystal driving (COFs) such as Chip On Film (Chip On Film).

The present embodiment has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the technical spirit of the present invention.

Examples

< 3. example >

Next, specific examples of the present invention will be described based on results of experiments actually carried out, but the present invention is not limited to these examples.

< production of film laminate >

First, a mixed solution was prepared by using ethyl acetate and toluene as organic solvents, and dissolving the film-forming materials, curing components, organic peroxides, and amine compounds shown in tables 1 and 2 below in the organic solvents so that the solid content became 50%. Subsequently, the mixed solution was coated on a polyethylene terephthalate film having a thickness of 50 μm, and dried at 70 ℃ for 5 minutes to prepare a film-shaped film laminate sample. The anisotropic conductive film materials in examples 1 to 6 and comparative examples 1 to 3 were blended as shown in tables 1 and 2. In addition, in the following evaluation, the use of the adjustment to the thickness of 20 u m samples.

[ Table 1]

[ Table 2]

The anisotropic conductive films of examples 1 to 6 and comparative examples 1 to 3 were subjected to on-resistance measurement and adhesion strength test.

< measurement of on-resistance >

In the test of on-resistance measurement, the connection structure 20 shown in fig. 3 was produced as follows, and the on-resistance was measured. First, a transparent conductive film (ITO film) 21a was attached to a glass having a thickness of 0.7mm, the anisotropic conductive films 22 of examples and comparative examples were attached to the obtained ITO glass 21, and a flexible printed circuit board (FPC)23 was mounted thereon. The flexible wiring board 23 used was a device for evaluating characteristics for measurement in which a wiring for measuring conduction was formed at a pitch of 50 μm with a size of 20mm × 40mm × 46 μm in total thickness and PI/Cu of 38 μm/8 μm. Next, the flexible wiring substrate 23 was heated by a pressure head toward the ITO glass 21 side under a temperature of 160 ℃ and a pressure of 4MPa while being pressurized for 4 seconds, and the anisotropic conductive film 22 was cured, thereby forming the connection structure 20 in which the printed wiring substrate 23 and the ITO glass 21 were electrically connected.

Then, the connection structure 20 of each of the examples and comparative examples was evaluated for the on-resistance value after being left for 500 hours (after aging) in an environment of 60 ℃/95% RH. The on-resistance value was measured by a 4-terminal method using a digital multimeter while a current of 1mA was passed. When the on-resistance value after aging is 5 Ω or less, the resistance is considered to be low.

< adhesion Strength test >

The connection structure 30 shown in fig. 4 was manufactured and subjected to an adhesion strength test. The connection structure 30 uses the ITO glass 31 and the flexible printed wiring board 32 having the same configuration as the above-described on-resistance measurement. The anisotropic conductive films 33 of the examples and comparative examples were interposed between the ITO glass 31 and the flexible printed wiring board 32, and the ITO glass and the flexible printed wiring board 32 were mechanically and electrically connected under the same temperature and heating conditions as those of the on-resistance measurement described above, to prepare the connection structure 30. Then, the connection structure 30 of each of the examples and comparative examples was cut out to a width of 10mm at the center of the flexible printed wiring board 32, and the anisotropic conductive film 33 exposed from the cut-out portion was pulled up at a peeling speed of 50 mm/min and 90 degrees (Y-axis direction) by a tensile tester (TENSILON, manufactured by orlistat (オリエンテック)), to measure the adhesive strength. When the adhesive strength is 4N/cm or more, the adhesive strength is considered to be high.

As is clear from the results shown in table 1, in examples 1 to 6 in which the anisotropic conductive film contains an imidazole compound, the adhesive strength of the anisotropic conductive film is increased due to the polarity of imidazole, the adhesive force between the ITO glass and the flexible printed wiring board is increased, and the adhesive strength is as high as 4N/cm or more. In addition, in examples 2 and 3 containing an imidazole compound having a cyano group, the adhesive strength was high, and as shown in example 2, even when the imidazole content was as small as 0.5 part by weight, the adhesive strength was high.

On the other hand, in comparative example 1, since the anisotropic conductive film contains the epoxy resin, the imidazole compound is consumed as the curing agent, the adhesive strength is reduced, and the electric resistance is increased, and in comparative example 2, since the bifunctional primary amine is used as the amine compound, the adhesive strength is not sufficiently improved, and the electric resistance is increased. In comparative example 3, since a linear tertiary amine compound was used as the amine compound, the adhesive strength was not sufficiently improved.

Description of the symbols

1 film laminate, 2 release film, 3 anisotropic conductive film, 4 adhesive, 5 conductive particles, 10 connection structure, 11 rigid wiring board, 12 IC chip, 13 terminal, 14 terminal.

Claims

1. An anisotropic conductive connecting material comprising conductive particles dispersed in an adhesive, characterized in that,

the adhesive contains a film-forming material, an acrylic resin, an organic peroxide and an amine compound,

the amine compound is a cyclic tertiary amine compound.

2. The anisotropic conductive connecting material according to claim 1, wherein the cyclic tertiary amine compound is an imidazole compound.

3. The anisotropic conductive connecting material according to claim 2, wherein the imidazole compound has a cyano group.

4. The anisotropic conductive connecting material according to any one of claims 1 to 3, wherein the content of the cyclic tertiary amine compound is 0.1 to 5 parts by mass with respect to 30 parts by mass of the acrylic resin.

5. The anisotropic conductive connecting material according to any one of claims 1 to 4, wherein the anisotropic conductive connecting material is formed in a film shape.

6. A film laminate comprising a release film and an anisotropic conductive connection layer formed of conductive particles dispersed in an adhesive,

the amine compound is a cyclic tertiary amine compound.

7. A connection method for connecting a terminal of a substrate and a terminal of an electronic component via an anisotropic conductive connection layer, comprising:

an adhesive layer forming step of forming an anisotropic conductive connection layer in which conductive particles are dispersed in an adhesive on a terminal of the substrate;

a mounting step of mounting the electronic component on the substrate through the anisotropic conductive connection layer so that a terminal of the electronic component faces a terminal of the substrate; and

a connection step of heating and pressing the electronic component from the upper surface of the electronic component by a pressing head, pressing the electronic component mounted on the substrate, and electrically connecting the terminals of the substrate and the terminals of the electronic component via the conductive particles of the anisotropic conductive connection layer;

the adhesive for the anisotropic conductive connection layer contains a film-forming material, an acrylic resin, an organic peroxide, and an amine compound, and the amine compound is a cyclic tertiary amine compound.

8. A connection structure in which an anisotropic conductive connection layer is present between a terminal of a substrate and a terminal of an electronic component to connect and conduct the substrate and the electronic component,

the anisotropic conductive connection layer is formed by dispersing conductive particles in an adhesive,

the amine compound is a cyclic tertiary amine compound.