TW201641634A - Anisotropic conductive film and connecting method - Google Patents

Abstract

An anisotropic conductive film which comprises: a conductive particle-containing layer that contains particles, a thermosetting resin and a curing agent; and an insulating bonding layer that contains a thermosetting resin and a curing agent. Each of the particles in the conductive particle-containing layer has a conductive core material and an insulating coating film that is on the surface of the conductive core material and contains a photoacid generator which generates an acid by means of an active energy ray having a predetermined wavelength. The thermosetting resin in the conductive particle-containing layer contains a curable resin that is cured by the acid. The curing agent in the conductive particle-containing layer is a curing agent that is not activated by the active energy ray having a predetermined wavelength. The curing agent in the insulating bonding layer is a curing agent that is not activated by the active energy ray having a predetermined wavelength.

Description

Anisotropic conductive film, and connection method

The present invention relates to an anisotropic conductive film and a method of joining the same using the anisotropic conductive film.

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

For example, the anisotropic conductive film is formed on a liquid crystal panel (LCD) by using a flexible printed circuit (FPC) or a terminal (electrode) of an integrated circuit (IC) chip. The case of indium tin oxide (ITO, Indium Tin Oxide) electrode connection on the glass substrate of Liquid Crystal Display is used for the case where various electrodes are connected to each other and electrically connected.

In recent years, electronic components have become more compact and integrated. Therefore, in the electrode of the electronic component, the distance between adjacent electrodes becomes smaller (macro). However, many of the conductive components used for the anisotropic conductive film are spherical, and their sizes are often several μm or more in diameter. When such an anisotropic conductive film is used, it is connected to a small electrode having an electrode pitch which is small in size and integrated, and there is a problem that insulation resistance between adjacent electrodes is insufficient.

Herein, a technique of reducing the risk of short circuit by using conductive particles coated with resin insulation in connection with a macro is proposed. As the resin for the insulating coating, for example, a thermoplastic resin, a thermosetting resin, or the like is exemplified. Although the use of insulating coated conductive particles can reduce the risk of short circuit to a certain extent, the strength of the insulating coating is designed to a certain extent because the conductive particles trapped between the opposing electrodes must be destroyed by the insulating coating. Weakening. Therefore, even if the conductive particles coated with the insulating material are subjected to thermal contraction stress from the element in a state of being interposed between the electrodes, there is a problem that the insulating coating is broken and short-circuited.

In addition to the thermoplastic resin and the thermosetting resin, a technique of using an active energy ray-curable resin has been proposed (for example, refer to Patent Documents 1 and 2). However, even in the technique of these proposals, in the macro connection, it is impossible to simultaneously prevent short-circuit between adjacent electrodes and conduct conduction between the opposing electrodes. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei.

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above-mentioned plurality of problems. That is, an object of the present invention is to provide an anisotropic conductive film capable of simultaneously preventing short-circuiting between adjacent electrodes and conducting conduction between opposing electrodes, and providing a joining method using the anisotropic conductive film. [Means for solving the problem]

The means for solving the above problems is as follows. That is, an anisotropic conductive film comprising: a conductive particle-containing layer containing particles, a thermosetting resin, and a curing agent; and an insulating adhesive layer containing a thermosetting resin and hardening The particle in the conductive particle-containing layer has a conductive core material and an insulating film containing a photoacid generator on the surface of the conductive core material, and the photoacid generator is given a wavelength The active energy ray generates an acid; the thermosetting resin in the conductive particle-containing layer has a curable resin which is cured by the acid; and the hardener in the conductive particle-containing layer cannot be given by the The hardener activated by the active energy ray of the wavelength; and the hardener in the insulating adhesive layer is a hardener that cannot be activated by the active energy ray of the given wavelength. <2> The anisotropic conductive film according to <1>, wherein the conductive particle-containing layer has an average thickness smaller than an average thickness of the insulating adhesive layer. <3> The anisotropic conductive film according to <1>, wherein the conductive particles contain a hardener-based cationic hardener in the layer, and the hardener-based cation in the insulating adhesive layer A hardener. <4> A connection method is a method of connecting a wiring of a substrate through which active energy rays are transmitted and a wiring board having wirings that are inaccessible to the active energy ray, and an electronic component, and the method includes: In the wiring process, the anisotropic conductive film according to any one of <1> to <3> is disposed on the wiring of the wiring substrate; and the second arrangement process is configured to dispose the electron on the anisotropic conductive film a component, the terminal of the electronic component is connected to the anisotropic conductive film; an active energy ray irradiation process, the active energy ray is irradiated from the wiring substrate side to the anisotropic conductive film; and a heating and pressing process is performed by heating Pressurizing the element to heat and pressurize the electronic component; wherein the active energy ray is an active energy ray containing a given wavelength and causing the photoacid generator to generate an acid. <5> The connection method according to <4>, wherein the second configuration process further comprises: a temporary fixing treatment to be smaller than a hardening temperature of the thermosetting resin in the conductive particle-containing layer, and the temperature is the hardening The anisotropic conductive film is heated and pressurized at a temperature of -10 ° C or higher. [Effects of the Invention]

According to the present invention, it is possible to solve the above-mentioned plurality of problems, and to achieve the above object, it is possible to provide an anisotropic conductive film capable of simultaneously preventing short-circuiting between adjacent electrodes and conducting conduction between opposing electrodes, and providing a use of the same A method of joining an anisotropic conductive film.

(Anisotropic Conductive Film) The anisotropic conductive film of the present invention has a conductive particle-containing layer and an insulating adhesive layer, and further has other components as necessary.

<Electrically conductive particle-containing layer> The conductive particle-containing layer contains at least particles, a thermosetting resin, and a curing agent, and further contains other components as necessary.

<<Particle>> This particle has a conductive core material and an insulating film, and has other components as necessary. In the particles, the insulating film is formed on the surface of the conductive core material.

- Conductive core material - The conductive core material is not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include metal particles and metal-coated resin particles.

The metal particles are not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include, for example, nickel, cobalt, silver, copper, gold, palladium, and the like. Among these, one type may be used alone or two or more types may be used in combination. Among these, nickel, silver, and copper are preferred. These metal particles can also be coated with gold or palladium on the surface for the purpose of preventing surface oxidation.

The metal-coated resin particles are not particularly limited as long as they are metal-coated particles, and may be appropriately selected depending on the purpose. For example, the surface of the resin particles may contain at least nickel or copper. Any metal coated particles of gold and palladium. The method of coating the resin particles with the metal is not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include, for example, electroless plating, sputtering, and the like. The material of the resin particles is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include, for example, a styrene-divinylbenzene copolymer, a benzoguanamine resin, a crosslinked polystyrene resin, an acrylic resin, Styrene-cerium oxide composite resin and the like.

-Insulating film - This insulating film contains at least a photoacid generator, and contains other components as necessary. In the non-pressurized state, in the case where a plurality of the particles are in contact, the insulating film preferably has an insulating property to such an extent that the particles do not conduct each other.

- Photoacid generator - The photoacid generator is not particularly limited as long as it is an acid generator which generates an acid by a given wavelength of active energy ray, and can be appropriately selected depending on the purpose, for example, Said, for example, Diazonium Salt, Diazoquinone Sulfonic Acid Amide, Diazoquinone Sulfonic Acid Ester, Diazoquinone Sulfonic Acid Salt, Nitrobenzyl Ester, sulfonium salt, halide, Iodonium salt, halogenated isocyanate, Halogenated Triazine, sulfonium salt, Biarylsulfonyl diazomethane (Bis Arylsulfonyl) Diazomethanes), disulfones, etc.

The photoacid generator absorbs the active energy ray of the given wavelength and produces an acid.

The active energy ray system of the given wavelength may be a single-wavelength active energy ray or an active energy ray having a complex wavelength band.

The content of the photoacid generator in the insulating film is not particularly limited, and can be appropriately selected depending on the purpose.

- Other components - The other components in the insulating film are not particularly limited and may be appropriately selected depending on the purpose, for example, a resin.

The resin is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include, for example, an acrylic resin, an epoxy resin, and the like. The resin may be the same type of resin as the thermosetting resin in the conductive particle-containing layer, or may be a different type of resin.

The average particle diameter of the particles is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 1 μm to 30 μm, more preferably 2 μm to 10 μm, and particularly preferably 3 μm to 6 μm. For example, the average particle diameter can be determined by using a scanning electron microscope (SEM) to measure the particle diameters of 50 particles, and the arithmetic mean thereof.

The average particle diameter of the particles is preferably smaller than the average thickness of the conductive particle-containing layer.

For example, the particle system can be produced by coating a resin composition containing the photoacid generator and the resin on the conductive core material. The method of the coating is not particularly limited, and can be appropriately selected depending on the purpose, and for example, a dry method using physical and chemical changes of mechanical energy, for example. In the apparatus for forming the insulating film on the surface of the conductive core material in the dry manner, for example, Mechano Mill (trade name, manufactured by Deshou Laboratories Co., Ltd.), Hybridizer (shared by Nara Machinery Co., Ltd.) Co., Ltd., trade name: NHS Series). In the dry mode, for example, the conductive core material and the powdery resin composition are treated by the apparatus to obtain the particles.

<<The thermosetting resin>> The thermosetting resin in the electroconductive particle-containing layer contains at least a curable resin which is hardened by the acid (acid derived from the photo-acid generator), and is contained as necessary. Other ingredients.

As the curable resin, for example, an epoxy resin, an Oxetane resin, or the like is exemplified.

The epoxy resin is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic type epoxy resin, and the like. Epoxy resin, etc.

The content of the thermosetting resin in the conductive particle-containing layer is not particularly limited, and can be appropriately selected according to the purpose, but the content of the thermosetting resin is 100 parts by mass based on the conductive particle-containing layer. It is preferably 10 parts by mass to 50 parts by mass, more preferably 20 parts by mass to 40 parts by mass.

<<Curing agent>> The curing agent in the conductive particle-containing layer is not a curing agent that cannot be activated by the active energy ray of a given wavelength and hardens the thermosetting resin. It is particularly limited and can be appropriately selected depending on the purpose, and examples thereof include, for example, a cationic hardener, an anionic hardener, and the like. Among these, it is difficult to react with an acid derived from the photoacid generator to cause hardening inhibition, and the curing agent is preferably a cationic hardener.

Here, the "activation" of the present invention means that the curing agent generates an active material which hardens the thermosetting resin. Since the hardener does not absorb the active energy ray of the given wavelength, the hardener does not generate the active material even when the active energy ray of the given wavelength is irradiated.

The cation hardening agent is not particularly limited as long as it is a cationic species by heat, and the thermosetting resin is cation-hardened, and can be appropriately selected depending on the purpose, for example, aryl diazonium. Salt-based hardener, Aryl Iodonium salt-based hardener, Aaryl Sulfonium salt, Allene-ion complex hardener, metal (for example, aluminum, titanium, zinc, tin, etc.), a chelate-based curing agent such as acetonitrile acetate or diketone. In particular, an arylsulfonium salt-based curing agent is preferably used from the viewpoint of excellent reactivity at low temperature and service life.

The arylsulfonium salt-based hardener is, for example, a structure exemplified by the following formulas (1) to (4).

[Chemical 1]

In the above formula (1), R _a is a hydrogen atom, a COCH ₃ group or a COOCH ₃ group, and each of R _B and R _c is a hydrogen atom, a halogen atom or a C ₁ -C ₄ alkyl group, and R _d is a hydrogen atom. CH ₃ group, OCH ₃ group or halogen atom, R _e is a C ₁ to C ₄ alkyl group, X system is SbF ₆ , AsF ₆ , PF ₆ or BF ₄ .

[Chemical 2]

In the above formula (2), R _f is a hydrogen atom, an ethenyl group, a methoxycarbonyl group, a methyl group, an epoxycarbonyl group, a t-butoxycarbonyl group, a benzamidine group, a phenoxycarbonyl group, a benzyloxycarbonyl group, or the like. 9-Fluorenylmethoxycarbonyl or p-Methoxybenzyl Group, each of R _g and R _h is a hydrogen atom, a halogen atom or a C ₁ -C ₄ alkyl group, R _i and Each of R _j is a hydrogen atom, a methyl group, a methoxy group or a halogen atom, and X is a group of SbF ₆ , AsF ₆ , PF ₆ or BF ₄ .

[Chemical 3]

In the above formula (3), R _k is an ethoxy group, a phenyl group, a phenoxy group, a benzyloxy group, a chloromethyl group, a dichloromethyl group, a trichloromethyl group or a trifluoromethyl group, and R _l and R _m are Each is a hydrogen atom, a halogen atom or a C ₁ -C ₄ alkyl group, R _n is a hydrogen atom, a methyl group, a methoxy group or a halogen atom, R _o is a C ₁ -C ₄ alkyl group, and X is a SbF _{6 group} . AsF ₆ , PF ₆ or BF ₄ .

[Chemical 4]

In the above formula (4), R _p is a hydrogen atom, an ethyl sulfonyl group, a methoxycarbonyl group, a methyl group, an epoxycarbonyl group, a t-butoxycarbonyl group, a benzamyl group, a phenoxycarbonyl group, a benzyloxycarbonyl group, or a 9-fluorene group. Oxycarbonyl or p-methoxybenzyl, R _q and R _r are each a hydrogen atom, a halogen atom or a C ₁ -C ₄ alkyl group, and R _s and R _t are each a methyl group or an ethyl group, and the X system is SbF _{6 .} , AsF ₆ , PF ₆ or BF ₄ .

Commercially available products can also be used as the cationic hardener. For the commercial product, for example, an aryldiazonium salt [for example, PP-33 (made by ADEKA Co., Ltd.)]; an aryl iodonium salt, an aryl sulfonium salt [for example, FC-509, FC) -540 (manufactured by 3M Company), UVE1014 (manufactured by GE Corporation), UVI-6974, UVI-6970, UVI-6990, UVI-6950 (manufactured by Union Carbide), SP-170, SP-150, CP-66, CP -77 (made by ADEKA CORPORATION)]; allene-ion complex (for example, CG-24-61 (manufactured by Ciba-Geigy Co., Ltd.)).

The anion-based curing agent is not particularly limited as long as it is an anion which hardens the thermosetting resin anion by heat, and can be appropriately selected depending on the purpose, for example, an imidazole hardener or a polythiol. Hardener, amine hardener, etc.

The content of the curing agent in the conductive particle-containing layer is not particularly limited, and can be appropriately selected according to the purpose. However, the content of the curing agent is preferably 5 based on 100 parts by mass of the conductive particle-containing layer. The mass fraction is preferably 30 parts by mass, more preferably 10 parts by mass to 20 parts by mass.

<<Other components>> The other components in the conductive particle-containing layer are not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include, for example, a film-forming resin, a decane coupling agent, and the like.

- Film-forming resin - The film-forming resin is not particularly limited and may be appropriately selected depending on the purpose, for example, a phenoxy resin, an unsaturated polyester resin, a saturated polyester resin, or a urethane. Resin, butadiene resin, polyimide resin, polyamide resin, polyolefin resin, and the like. These film-forming resins may be used alone or in combination of two or more. Among these, a phenoxy resin is preferred from the viewpoints of film formability, workability, and connection reliability. The phenoxy resin is, for example, a resin synthesized by bisphenol A or epichlorohydrin, or the like. As the phenoxy resin, a suitably synthesized product or a commercially available product can be used.

The content of the film-forming resin in the conductive particle-containing layer is not particularly limited, and can be appropriately selected according to the purpose. However, the content of the film-forming resin is preferably 100 parts by mass based on the conductive particle-containing layer. It is 10 parts by mass to 50 parts by mass, more preferably 20 parts by mass to 40 parts by mass.

- decane coupling agent - The decane coupling agent is not particularly limited and may be appropriately selected depending on the purpose, for example, an epoxy decane coupling agent, an acrylic decane coupling agent, a thiol decane coupling agent, an amine A decane coupling agent or the like.

The content of the decane coupling agent in the conductive particle-containing layer is not particularly limited, and can be appropriately selected depending on the purpose. However, the content of the decane coupling agent is preferably 100 parts by mass based on the conductive particle-containing layer. It is 0.1 parts by mass to 3.0 parts by mass, more preferably 0.5 parts by mass to 2.0 parts by mass.

The average thickness of the conductive particle-containing layer is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 1 μm to 30 μm, more preferably 3 μm to 10 μm, and particularly preferably 5 μm to 8 μm. The average thickness here is an arithmetic mean value after measuring the thickness of any five positions of the conductive particle-containing layer.

The average thickness of the conductive particle-containing layer is preferably smaller than the average thickness of the insulating adhesive layer from the viewpoint of simultaneously preventing the short circuit between the adjacent electrodes and conducting the conduction between the opposing electrodes. The average thickness of the conductive particle-containing layer and the average thickness difference of the insulating adhesive layer [(average thickness of the insulating adhesive layer) - (average thickness of the conductive particle-containing layer)] are more preferably 2 μm. ~15 μm, particularly preferably 4 μm to 10 μm.

<Insulating Adhesive Layer> The insulating adhesive layer contains at least a thermosetting resin and a curing agent, and further contains other components as necessary.

<<Thermosetting Resin>> The thermosetting resin in the insulating adhesive layer is not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include an epoxy resin and an acrylic resin. Among these, the thermosetting resin is preferably an epoxy resin.

The epoxy resin is, for example, an epoxy resin exemplified in the description of the thermosetting resin containing the conductive particle-containing layer.

The content of the thermosetting resin in the insulating adhesive layer is not particularly limited, and may be appropriately selected depending on the purpose. However, the content of the thermosetting resin is preferably 100 parts by mass based on the insulating adhesive layer. It is 20 parts by mass to 60 parts by mass, more preferably 30 parts by mass to 50 parts by mass.

<<Curing agent>> The curing agent in the insulating adhesive layer is not particularly limited as long as it is a curing agent for curing the thermosetting resin, and can be appropriately selected depending on the purpose, for example, a cationic system. A hardener, an anionic hardener, and the like. Among these, from the viewpoint that the reaction is not easily caused, the hardener is preferably selected from the same reaction system as in the conductive particle-containing layer. In other words, when the conductive particles contain a curing agent-based cationic curing agent in the layer, the curing agent in the insulating adhesive layer is preferably a cationic curing agent, and the conductive particles contain a curing agent in the layer. In the anionic curing agent, the curing agent in the insulating adhesive layer is preferably an anionic curing agent. Among these, the conductive particles contain a hardener-based cationic hardener in the layer, and the insulating adhesive layer can be prevented from simultaneously preventing a short circuit between adjacent electrodes and conducting conduction between the opposing electrodes. The hardener in the middle is preferably a cationic hardener.

The cationic curing agent is not particularly limited as long as it is a cationic species which generates a cationic species by heat, and can be appropriately selected depending on the purpose, for example, the conductive particles. A cationic hardener or the like exemplified in the description of the hardener containing the layer.

The anion-based curing agent is not particularly limited as long as it is an anion which hardens the thermosetting resin anion by heat, and can be appropriately selected depending on the purpose. For example, the conductive particle-containing layer is used. An anionic curing agent or the like exemplified in the description of the curing agent.

The content of the curing agent in the insulating adhesive layer is not particularly limited, and can be appropriately selected depending on the purpose. However, the content of the curing agent is preferably 5 parts by mass based on 100 parts by mass of the insulating adhesive layer. ~30 parts by mass, more preferably 10 parts by mass to 20 parts by mass.

<<Other components>> The other components in the insulating adhesive layer are not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include, for example, a film-forming resin, a decane coupling agent, and the like.

- Film-forming resin - The film-forming resin is not particularly limited, and may be appropriately selected depending on the purpose. For example, the film-forming resin exemplified in the description of the conductive particle-containing layer may be used. The film-forming resin is preferably a phenoxy resin from the viewpoint of film formability, workability, and connection reliability.

The content of the film-forming resin in the insulating adhesive layer is not particularly limited, and can be appropriately selected depending on the purpose. However, the content of the film-forming resin is preferably 5 based on 100 parts by mass of the insulating adhesive layer. The mass portion is -45 parts by mass, more preferably 15 parts by mass to 35 parts by mass.

- decane coupling agent - The decane coupling agent is not particularly limited and may be appropriately selected depending on the purpose, for example, an epoxy decane coupling agent, an acrylic decane coupling agent, a thiol decane coupling agent, an amine A decane coupling agent or the like.

The content of the decane coupling agent in the insulating adhesive layer is not particularly limited and may be appropriately selected depending on the purpose. However, the content of the decane coupling agent is preferably 0.1 based on 100 parts by mass of the insulating adhesive layer. The mass portion is -3.0 parts by mass, more preferably 0.5 parts by mass to 2.0 parts by mass.

The average thickness of the insulating adhesive layer is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 5 μm to 50 μm, more preferably 7 μm to 30 μm, and particularly preferably 10 μm to 15 μm. The average thickness here is an arithmetic mean value after measuring the thickness of any five positions of the insulating backing layer.

The average thickness of the anisotropic conductive film is not particularly limited and can be appropriately selected depending on the purpose.

(Connection Method) The connection method of the present invention includes at least a first configuration process, a second configuration process, an active energy ray irradiation process, and a heating and pressurization process, and further includes other processes as necessary. This connection method is a connection method in which the wiring of the wiring substrate and the terminals of the electronic component are connected by an anisotropic conductive film.

<First Configuration Process> The first arrangement process is not particularly limited as long as it is disposed on the wiring of the wiring substrate, and the anisotropic conductive film of the present invention is disposed, and can be appropriately selected depending on the purpose. In the first arrangement process, it is preferable that the anisotropic conductive film is disposed on the wiring of the wiring substrate, and the conductive particle-containing layer is connected to the wiring.

<<Wiring Substrate>> This wiring board has at least a substrate and wiring, and has other elements as necessary.

- Substrate - The substrate is not particularly limited as long as it is an active energy ray-transparent substrate, and can be appropriately selected depending on the purpose, and examples thereof include, for example, a plastic substrate, a glass substrate, and the like. The shape, size, and structure of the substrate are not particularly limited, and can be appropriately selected depending on the purpose. Here, the "active energy ray penetration" means an active energy ray which is a necessary wavelength for causing the photoacid generator to generate an acid, and is required to penetrate the photoacid generator to generate acid. Yes, the transmittance of the active energy ray at this wavelength need not be 100%.

- Wiring - The wiring is not particularly limited as long as it is a wiring that does not penetrate the active energy ray, and can be appropriately selected depending on the purpose. The wiring system is disposed on the substrate. As the material of the wiring, for example, gold, silver, copper, aluminum, or the like is exemplified. The shape, size, and structure of the wiring are not particularly limited, and can be appropriately selected depending on the purpose. Here, "the active energy ray does not penetrate" means an active energy ray which is a necessary wavelength for causing the photoacid generator to generate an acid, and does not penetrate to such an extent that the photoacid generator does not generate an acid. That is, the transmittance of the active energy ray at this wavelength need not be 0%. However, the transmittance of the active energy ray of the wiring is preferably 0%.

<Second Configuration Process> In the second arrangement process, as long as the electronic component is disposed on the anisotropic conductive film, and the terminal of the electronic component is connected to the anisotropic conductive film, Although it is not particularly limited, it can be appropriately selected according to the purpose, but it is possible to simultaneously prevent the short circuit between the adjacent electrodes and conduct the conduction between the opposing electrodes at the same time, and preferably includes a temporary fixing treatment to be smaller than the conductivity. The anisotropic conductive film is heated and pressurized by the temperature at which the particles contain the thermosetting resin of the layer and at a temperature as high as possible. At this time, it is preferable to pressurize by a pressure higher than usual (for example, 5 MPa to 40 MPa). Further, in terms of heating and pressurizing time, it is preferably from 0.5 second to 2 seconds. Here, the "hardening temperature of the thermosetting resin" is a temperature at which the lowest melt viscosity is exhibited by the rheometer melt viscosity measurement (temperature rising rate: 30 ° C / min). Meanwhile, it is preferable that the curing temperature is less than the curing temperature and the curing temperature is -10 ° C or more, and more preferably less than the curing temperature of the thermosetting resin of the conductive particle-containing layer. The hardening temperature is the hardening temperature of -5 ° C or more.

<<Electronic component>> As for the electronic component, the electronic component having the terminal is not particularly limited as long as it is a connection object, and can be appropriately selected depending on the purpose, for example, an IC chip, a TAB tape, or the like. LCD panel, etc. The IC chip is, for example, a liquid crystal panel control IC chip or the like in a flat panel display (FPD).

<Active energy ray irradiation process> The active energy ray irradiation process is not particularly limited as long as it is a process of irradiating the active energy ray from the wiring substrate side to the anisotropic conductive film, and can be appropriately adapted to the purpose select.

The active energy ray is not particularly limited as long as it contains an active energy ray which generates an acid for the photoacid generator, but it can be appropriately selected according to the purpose, but since the wavelength of the active energy ray is less than 300 nm, It is easy to activate a wide variety of photoacid generators, and in the case where the wavelength of the active energy ray exceeds 450 nm, the kind of photoacid generator which can be activated becomes extremely small, so that only the insulating film is activated as in the present invention. In the photo-acid generator in the middle, the curing agent for the conductive particle-containing layer and the hardener for the insulating resin layer are formed in an inactive composition, and the degree of freedom in selecting the wavelength of the active energy ray is extremely lowered. Therefore, in terms of the active energy ray, it is preferably from 300 nm to 450 nm, more preferably from 350 nm to 420 nm. The irradiation source of the active energy ray is not particularly limited and may be appropriately selected depending on the purpose, and may be, for example, a deep UV lamp, an LED lamp, a YAG laser, a xenon lamp, a halogen lamp, etc., but only activates the insulating film. The photoacid generator is preferably an LED lamp having a narrow wavelength region. The amount of irradiation of the active energy ray is not particularly limited and can be appropriately selected depending on the purpose.

By performing the active energy ray irradiation process and generating an acid by a photo-acid generator in the particles adjacent to the electrodes (between the wirings on the wiring substrate), the conductive particles are contained in the layer, around the particles. The thermosetting resin is hardened. On the other hand, the thermosetting resin around the particles between the counter electrodes (between the wiring of the wiring substrate and the terminals of the electronic component) is not cured. Therefore, when the heating and pressurizing process is performed after the active energy ray irradiation process, the cured resin film formed around the particles adjacent to the electrodes is not broken, so that the insulation between the adjacent electrodes can be maintained. On the other hand, since the insulating film of the particles between the target electrodes is broken, the conductive core material is in contact with the wiring and the terminal, and conduction between the opposing electrodes can be obtained.

<Heating and Pressurization Process> The heat and pressure process is not particularly limited as long as it is a process of heating and pressurizing the electronic component by heating and pressing the member, and can be appropriately selected depending on the purpose.

As the heating and pressurizing member, for example, a pressurizing member having a heating mechanism or the like is exemplified. As the pressurizing member having the heating mechanism, for example, a heating tool or the like. The temperature of the heating is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 130 ° C to 200 ° C. The pressure of the pressurization is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 40 MPa to 100 MPa. The time of the heating and pressurization is not particularly limited and may be appropriately selected depending on the purpose, but is preferably from 3 seconds to 15 seconds.

An example of the connection method of the present invention will be described with reference to Figs. 1A to 1D. First, as shown in FIG. 1A, an anisotropic conductive film having the conductive particle-containing layer 3 and the insulating adhesive layer 4 is disposed on the wiring substrate having the substrate 1 and the wiring 2 (first arrangement process). At this time, the conductive particle-containing layer 3 is placed in contact with the wiring 2 . The conductive particle-containing layer 3 has a thermosetting resin, a curing agent, and particles. This particle has a conductive core material 31 and an insulating film 32 formed on the surface of the conductive core material 31. The insulating film 32 contains a photoacid generator.

Next, as shown in FIG. 1B, on the anisotropic conductive film, the electronic component 5 is placed, and the terminal 6 of the electronic component 5 is connected to the anisotropic conductive film (second configuration process). In this case, it is preferable to include a temporary fixing treatment to heat and press the anisotropic conductive film at a temperature lower than the curing temperature of the thermosetting resin of the conductive particle-containing layer and at a temperature as high as possible.

Next, as shown in FIG. 1C, an active energy ray is irradiated from the wiring substrate side to the anisotropic conductive film (active energy ray irradiation process). Then, an acid is generated from the photo-acid generator in the insulating film 32 of the particles between the adjacent electrodes (between the wires 2 on the wiring substrate), and the thermosetting resin around the particles is cured to form the cured resin film 33. On the other hand, since there is no photoacid generator of the insulating film 32 in the particles between the counter electrodes (between the wiring 2 of the wiring substrate and the terminal 6 of the electronic component 5) to generate an acid, the heat around the particles The hardened resin is not hardened.

Next, as shown in FIG. 1D, the electronic component (heat and pressure process) is heated and pressurized by heating the pressurizing member. Then, the cured resin film 33 in the particles adjacent to the electrodes is not broken, and the insulation between the adjacent electrodes is maintained. On the other hand, the insulating film 32 of the particles between the opposing electrodes is broken when the particles are deformed. Then, the conductive core member 31 is in contact with the wiring 2 and the terminal 6, so that conduction between the opposing electrodes can be obtained. In the case where the same type of thermosetting resin, film forming resin, curing agent, or the like is used for the conductive particle-containing layer and the insulating adhesive layer, the conductive particle-containing layer and the insulating adhesive layer are formed after the heating and pressing process. The interface becomes less obvious and almost integrated.

Since the anisotropic conductive film of the present invention and the connection method of the present invention can simultaneously prevent short-circuiting between adjacent electrodes and conduct conduction between the opposing electrodes, it can be applied to a narrow pitch (referred to as macro) connection between adjacent electrodes. In terms of the pitch, 20 μm or less is also acceptable, and 15 μm is also compatible. [Examples]

Hereinafter, the embodiments of the present invention have been described, but the present invention is not limited by the embodiments.

(Production Example 1) <Preparation of Particles> A particle-based resin composition containing a photoacid generator (LW-S1, manufactured by SAN-APRO Co., Ltd.) having an absorption wavelength of around 360 nm was coated on a conductive core material. To make. Specifically, it is produced as follows. 90 parts by mass of a conductive core material (AUL704, manufactured by Sekisui Chemical Co., Ltd., average particle diameter: 4 μm), 10 parts by mass of a powdery acrylic resin, and 10 parts by mass of a cationic light curing agent were placed in Hybridizer (manufactured by Nara Machinery Co., Ltd.) , trade name: NHS Series), and processing. Further, the treatment conditions in the Hybridizer were a rotation speed of 16,000 rpm and a reaction tank temperature of 60 °C. The obtained particles had an average particle diameter of 4.1 μm.

(Production Example 2) <Preparation of Particles> The particles were obtained in the same manner as in Production Example 1 except that the acrylic resin in Production Example 1 was replaced with an epoxy (meth)acrylic resin. The obtained particles had an average particle diameter of 4.1 μm.

(Production Example 3) <Preparation of particles> 90 parts by mass of a conductive core material (AUL704, manufactured by Sekisui Chemical Co., Ltd., average particle diameter: 4 μm) and 10 parts by mass of a powdery acrylic resin were placed in Hybridizer (Nara Machinery Manufacturing Co., Ltd.) Company system, trade name: NHS Series), and processing. Further, the treatment conditions in the Hybridizer were a rotation speed of 16,000 rpm and a reaction tank temperature of 60 °C. The obtained particles had an average particle diameter of 4.1 μm.

(Example 1) <Preparation of an anisotropic conductive film> - Preparation of a conductive particle-containing layer - 40 parts by mass of a phenoxy resin (product name: YP50, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), epoxy resin (product name: EP828, manufactured by Mitsubishi Chemical Corporation) 40 parts by mass, cationic hardener (product name: San-Aid SI-80L, manufactured by Sanshin Chemical Co., Ltd.) 20 parts by mass, decane coupling agent (product name: A-187 1 part by mass of the particles produced by Momentive Performance Materials, and 35 parts by mass of the particles produced in Production Example 1 were uniformly mixed using a stirring device (rotary revolution agitator, decanting, Taro, manufactured by Thinky Co., Ltd.). The compound after the mixture was dried and applied to a polyethylene terephthalate (PET, Polyethylene Terephthalate) having an average thickness of 5 μm, and dried at 70 ° C for 5 minutes to prepare conductive particles. Floor.

- Preparation of an insulating adhesive layer - 30 parts by mass of phenoxy resin (product name: YP50, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) and epoxy resin (product name: EP828, manufactured by Mitsubishi Chemical Corporation) 40 parts by mass 20 parts by mass of a cationic hardener (product name: San-Aid SI-80L, manufactured by Sanshin Chemical Co., Ltd.) and 1 part by mass of a decane coupling agent (product name: A-187, manufactured by Momentive Performance Materials Co., Ltd.) using a stirring device (Rotating revolution mixer, in addition to soaking Taro, made by Thinky) uniformly mixed. The mixed compound was applied to a permeated polyethylene terephthalate (PET) after being dried to have an average thickness of 15 μm, and dried at 70 ° C for 5 minutes to prepare an insulating back layer. .

The conductive particle-containing layer obtained was bonded to an insulating adhesive layer to obtain an anisotropic conductive film.

<Manufacturing of Bonded Body> COG (Chip on Glass) mounting was carried out by the following method. A glass substrate having a thickness of 0.7 mm formed using ITO comb-shaped wiring was used as the wiring substrate. As the electronic component, a test IC wafer (size: 1.8 mm × 20 mm, thickness: 0.5 mm, size of gold-plated bump: 13 μm × 80 μm, bump height: 15 μm, gap between bumps: 12 μm) was used. An anisotropic conductive film is placed on the wiring of the wiring board, and the conductive particle-containing layer is connected to the wiring. Next, the electronic component was placed on the insulating adhesive layer of the anisotropic conductive film, and a Teflon (trademark registration) sheet having an average thickness of 50 μm was used as a buffer material, and 100 ° C, 10 MPa, by a heating tool. The electronic component was heated and pressurized for 1 second to temporarily fix it. Next, from the wiring substrate side, UV irradiation was performed on the anisotropic conductive film (using a 400 mW × 2 sec irradiation, a UV LED light source manufactured by Omron Corporation, ZUV-C20H, ZUV-H20MC). Next, a Teflon (trademark registration) sheet having an average thickness of 50 μm was used as a buffer material, and the electronic component was heated and pressurized at 200 ° C, 60 MPa, and 5 seconds by a heating tool to obtain a connection. Joint body. Further, although the photoacid generator in the particles generates an acid by UV irradiation, the hardener in the conductive particle-containing layer and the hardener in the insulating adhesive layer are not activated.

<Evaluation> The following evaluations are provided. The results are shown in Table 1-1.

<<Case of occurrence of short circuit>> The resistance value (Ω) between the terminals of 16 ch was measured using a High Resistance Meter (product number: High Resistance Meter 4339B, manufactured by Agilent Co., Ltd.). Specifically, a chor having a resistance value of 10 ⁸ Ω or less when the voltage is 30 V is printed by the two-terminal method is considered to be a short circuit, and is evaluated by the following evaluation criteria. [Evaluation Criteria] ○: The number of chs that have a short circuit is 0 △: The number of chs that have a short circuit is 1-2 ╳: The number of chs that have a short circuit is 3-16

<<Conductive Resistance Value>> The resistance value (Ω) between the terminal-ITO wiring of 30ch was measured using a Digital Multimeter (product number: Digital Multimeter 7555, manufactured by Yokogawa Electric Corporation). Specifically, the resistance value (conductive resistance value, Ω) after 500 hours elapsed at 85 ° C and 85% RH was measured when a current of 1 mA was passed through the 4-terminal method. The evaluation was performed by the following evaluation criteria. [Evaluation Criteria] ○: Less than 10 Ω △: 10 Ω or more and less than 50 Ω ╳: 50 Ω or more

(Examples 2 to 8 and Comparative Examples 1 to 5) <Preparation of an anisotropic conductive film and production of a bonded body> The composition and insulating properties of the conductive particle-containing layer (ACF layer) in Example 1 were followed. The composition of the layer (NCF layer), the average thickness of the two layers, the heating and pressing conditions when the two layers are temporarily fixed, and whether or not the two layers are subjected to UV irradiation are changed as described in Table 1-1 and Table 1-2. In the same manner as in the first embodiment, the production of the anisotropic conductive film and the production of the bonded body were carried out. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1-1 and Table 1-2.

Table 1-1]

Table [1-2] In Table 1-1 and Table 1-2, AUL-704 is a conductive particle (Ni/Au, resin core, manufactured by Sekisui Chemical Co., Ltd., and the average particle diameter is 4 μm). PKHH is a phenoxy resin (manufactured by Ba Chemical Industry Co., Ltd.). JER806 is a bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation). PHX3941HP is an imidazole hardener (made by Asahi Kasei Co., Ltd.). The deep UV irradiation in Comparative Example 5 used SP-9 manufactured by USHIO. In Comparative Example 5, the photo-acid generator in the particles was activated by the deep UV irradiation, and the hardener in the conductive particle-containing layer and the hardener in the insulating adhesive layer were activated.

In the first to eighth embodiments, the occurrence of a short circuit can be prevented at the same time and conduction can be ensured. When the average thickness of the conductive particle-containing layer was 5 μm to 8 μm, particularly excellent results were obtained (see Examples 1 to 2 and Examples 5 to 7). When the average thickness of the electroconductive particle-containing layer exceeds 8 μm, the trapping property of the particles in the counter electrode is slightly deteriorated. At the same time, the active energy ray is diffracted from the side of the wiring to the particles between the counter electrodes, and the thermosetting resin around the counter electrode is also slightly hardened. Then, the active energy ray becomes difficult to reach the farther particles from the substrate. As a result of this, when the average thickness of the conductive particle-containing layer exceeds 8 μm, the prevention of occurrence of short-circuit and the prevention of conduction are worse than the case where the average thickness of the conductive particle-containing layer is 5 μm to 8 μm. In the second arrangement process, the temperature at which the hardening temperature of the thermosetting resin containing the conductive particle-containing layer is lower and the temperature is as high as possible (less than the curing temperature, and the curing temperature is -10 ° C or higher) is used. When the anisotropic conductive film was heated and pressurized (see Examples 1 to 2 and Examples 5 to 7), it was more excellent in the conduction resistance value than in the case where the above operation was not performed (Example 4). In the eighth embodiment, since both the curing agent for the conductive particle-containing layer and the curing agent for the insulating adhesive layer are an anionic curing agent, a part of the acid generated from the photo-acid generator is lost by the active energy ray. As a result of the activity, the effect of preventing the occurrence of a short circuit by the anionic hardener is also lower than when the cationic hardener is selected. At the same time, when heating and pressurizing, the anion species is slightly deactivated by the photoacid generator contained in the insulating film of the conductive particles, and the conductive resistance value of the anionic hardener is selected as the cationic hardener. It is still bad. In Comparative Examples 1 to 4, it was not possible to simultaneously prevent the occurrence of a short circuit and ensure conduction. Even in Comparative Example 3 in which the conductive particles were covered with the conventional insulation, it was impossible to cope with the 12 μm macro, and therefore it was impossible to prevent the occurrence of the short circuit and ensure the conduction. In the comparative example 5, the hardener of the electroconductive particle-containing layer and the hardener of the insulating adhesive layer are activated by the active energy ray (deep UV), and the thermosetting resin and the insulating property of the electroconductive particle-containing layer are continued. The layer of the thermosetting resin is hardened before heating and pressurization, resulting in insufficient conduction resistance. [Industrial availability]

Since the anisotropic conductive film of the present invention and the connection method of the present invention can simultaneously prevent short-circuiting between adjacent electrodes and conduct conduction between the opposing electrodes, it can be applied to a narrow pitch (referred to as a macro) connection between adjacent electrodes. .

1‧‧‧Substrate
2‧‧‧Wiring
3‧‧‧ Conductive particle containing layer
4‧‧‧Insulating adhesive layer
5‧‧‧Electronic components
6‧‧‧ terminals
31‧‧‧Electrical core material
32‧‧‧Insulation film
33‧‧‧ hardened resin film

Fig. 1A is a schematic view showing a first arrangement process for explaining an example of the connection method of the present invention. Fig. 1B is a schematic view for explaining a second arrangement process in an example of the connection method of the present invention. Fig. 1C is a schematic view showing an active energy ray irradiation process in an example of the connection method of the present invention. Fig. 1D is a schematic view for explaining a heating and pressurizing process in an example of the joining method of the present invention.

1‧‧‧Substrate

2‧‧‧Wiring

3‧‧‧ Conductive particle containing layer

4‧‧‧Insulating adhesive layer

5‧‧‧Electronic components

6‧‧‧ terminals

31‧‧‧Electrical core material

32‧‧‧Insulation film

33‧‧‧ hardened resin film

Claims (5)

An anisotropic conductive film comprising: a conductive particle-containing layer containing particles, a thermosetting resin, and a curing agent; and an insulating adhesive layer containing a thermosetting resin and a curing agent; wherein the conductive layer The particle system in the particle-containing layer has a conductive core material and an insulating film containing a photoacid generator on the surface of the conductive core material, and the photoacid generator is produced by an active energy ray of a given wavelength. The thermosetting resin in the conductive particle-containing layer has a curable resin which is cured by the acid; the hardener in the conductive particle-containing layer cannot be used by the active energy ray of the given wavelength. The activated hardener; and the hardener in the insulative adhesive layer are hardeners that are not activated by the active energy ray of the given wavelength. The anisotropic conductive film according to claim 1, wherein the conductive particle-containing layer has an average thickness smaller than an average thickness of the insulating adhesive layer. The anisotropic conductive film according to claim 1, wherein the conductive particles contain a curing agent-based cationic curing agent in the layer, and the curing agent in the insulating adhesive layer is a cationic curing agent. A connection method is a method of connecting a wiring of a substrate through which an active energy ray penetrates and a wiring substrate having a wiring that cannot penetrate the active energy ray to an electronic component, and the method includes: a first configuration process, An anisotropic conductive film according to any one of claims 1 to 3, wherein the electronic component is disposed on the anisotropic conductive film on the wiring of the wiring substrate, and the electronic component is disposed on the wiring The terminal of the component is connected to the anisotropic conductive film; the active energy ray irradiation process irradiates the active energy ray to the anisotropic conductive film from the side of the wiring substrate; and the heating and pressing process is heated by heating and pressing the component And pressurizing the electronic component; wherein the active energy ray is an active energy ray containing a given wavelength and causing the photoacid generator to generate an acid. The connection method according to claim 4, wherein the second configuration process further comprises: a temporary fixing process to be smaller than a hardening temperature of the thermosetting resin in the conductive particle-containing layer, and the temperature is the hardening temperature -10 The anisotropic conductive film is heated and pressurized at a temperature above °C.