TW201920555A - Adhesive film for circuit connection and method for manufacturing same, method for manufacturing circuit connection structure, and adhesive tape-containing set - Google Patents

Abstract

An adhesive film 1 for circuit connection, said adhesive film 1 being provided with a first adhesive layer 2 and a second adhesive layer 3 that is laminated on the first adhesive layer 2, wherein: the first adhesive layer 2 is formed of a cured product of a photo-curable composition; the second adhesive layer 3 is formed of a heat-curable composition; and the photo-curable composition comprises a polymerizable compound, conductive particles 4 and a photopolymerization initiator having at least one structure selected from the group consisting of a structure represented by formula (I), a structure represented by formula (II) and a structure represented by formula (III).

Description

Adhesive film for circuit connection and manufacturing method thereof, method for manufacturing circuit connection structure, and adhesive film storage kit

The invention relates to an adhesive film for circuit connection, a method for manufacturing the same, a method for manufacturing a circuit connection structure, and an adhesive film storage kit.

Conventionally, various bonding materials have been used for circuit connection. For example, it is used for connection between a liquid crystal display and a tape carrier package (TCP), connection between a flexible printed wiring board (Flexible Printed Circuit, FPC) and TCP, or connection between FPC and a printed wiring board. As the material, an adhesive film for circuit connection having conductive particles dispersed in the adhesive and having anisotropic conductivity has been used.

In the field of precision electronic equipment using an anisotropic conductive adhesive film for circuit connection, the density of circuits is promoted, and the electrode width and the electrode interval are extremely narrow. Therefore, it is not necessarily easy to efficiently capture conductive particles on a minute electrode and obtain high connection reliability.

In this regard, for example, Patent Document 1 proposes a method in which conductive particles are biased to exist on one side of an anisotropic conductive adhesive sheet, and the conductive particles are separated from each other. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2005/54388

[Problems to be Solved by the Invention] However, in the method of Patent Document 1, conductive particles flow during circuit connection, and thus conductive particles may condense between electrodes to cause a short circuit. In addition, as for the dense and dense distribution of the conductive particles accompanying the flow of the conductive particles, there is a concern not only that the insulation characteristics are reduced, but also that the connection resistance value varies, and there is still room for improvement.

Therefore, an object of the present invention is to provide an adhesive film for circuit connection, which can reduce the connection resistance between opposing electrodes of a circuit connection structure, a method for manufacturing the same, a method for manufacturing a circuit connection structure using the same, and a method including the same. The adhesive film storage kit of this adhesive film. [Means for solving problems]

An adhesive film for circuit connection according to an aspect of the present invention includes a first adhesive layer and a second adhesive layer laminated on the first adhesive layer. The first adhesive layer includes curing of a photocurable composition. The second adhesive layer includes a thermosetting composition, and the photocurable composition includes a polymerizable compound; conductive particles; and a structure selected from the group consisting of the following formula (I) and the following formula (II): A photopolymerization initiator of at least one structure in the group consisting of the structure represented by the structure represented by the following formula (III). [Chemical 1] [Chemical 2] [Chemical 3]

According to such an adhesive film for circuit connection, the connection resistance between the opposing electrodes of the circuit connection structure can be reduced. Furthermore, according to such an adhesive film for circuit connection, a low connection resistance can be maintained in a high-temperature and high-humidity environment (for example, 85 ° C, 85% RH). That is, according to this adhesive film for circuit connection, the connection reliability of a circuit connection structure can be improved.

A method for producing an adhesive film for circuit connection according to an aspect of the present invention includes a preparation step of preparing a first adhesive layer, and a laminating step of laminating a second adhesive containing a thermosetting composition on the first adhesive layer. And the preparation step includes the step of obtaining a first adhesive layer by hardening the photocurable composition by irradiating the layer containing the photocurable composition with light, the photocurable composition containing: a polymerizable compound; conductive particles ; And photopolymerization having at least one structure selected from the group consisting of the structure represented by the formula (I), the structure represented by the formula (II), and the structure represented by the formula (III) Initiator. According to this method, an adhesive film for circuit connection which can reduce the connection resistance between the opposing electrodes of the circuit connection structure can be obtained.

The photopolymerization initiator may have at least one structure selected from the group consisting of a structure represented by the following formula (IV) and a structure represented by the following formula (V) as the formula (II) structure. [Chemical 4] [In formula (IV), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms] [Chem. 5]

The polymerizable compound may be a radical polymerizable compound having a radical polymerizable group.

The photopolymerization initiator may have at least one structure selected from the group consisting of an oxime ester structure, an α-aminobenzoyl ketone structure, and a fluorenylphosphine oxide structure as the formulae (I) to (III) The structure represented.

The thermosetting composition may contain a radical polymerizable compound having a radical polymerizable group.

The thickness of the first adhesive layer may be 0.2 to 0.8 times the average particle diameter of the conductive particles.

A method for manufacturing a circuit connection structure according to an aspect of the present invention includes the steps of interposing the adhesive film for circuit connection described above between a first circuit member having a first electrode and a second circuit member having a second electrode. In between, the first circuit member and the second circuit member are thermocompression-bonded to electrically connect the first electrode and the second electrode to each other. According to this method, a circuit connection structure capable of reducing the connection resistance between the opposed electrodes can be obtained.

An adhesive film storage kit according to an aspect of the present invention includes the above-mentioned adhesive film for circuit connection, and a storage member for accommodating the adhesive film. The storage member has a viewing portion that allows the inside of the storage member to be viewed from the outside. The visible part has a transmittance of 10% or less for light having a wavelength of 365 nm.

However, in general, the environment in which the adhesive film for circuit connection is used is a room called a clean room and the temperature, humidity, and cleanliness of the room are managed at a certain level. When the adhesive film for circuit connection is shipped from the production site, the adhesive film for circuit connection is stored in a storage member such as a packaging bag, so as not to be directly exposed to external air and deteriorated by dust and moisture. Generally, a viewing portion is provided on the storage member, and the viewing portion is formed of a transparent material, so that various information such as a product name, a batch number, and an expiration date attached to the internal adhesive film can be confirmed from the outside of the storage member. .

However, according to research by the present inventors, when the above-mentioned adhesive film for circuit connection is stored in an existing storage member for storage or transportation, the connection resistance of the adhesive film may not be obtained in some cases. Reduce effect. Based on the results of such studies, the present inventors and others conducted further studies, and as a result, it was found that when a compound capable of reacting with a photopolymerization initiator in the photocurable composition is used as the polymerizable compound in the second adhesive layer, The thermosetting composition hardens during storage and transportation of the adhesive film, and the effect of reducing the connection resistance is reduced. Therefore, based on the presumption that the polymerizable compound in the thermosetting composition is polymerized by radicals derived from the photopolymerization initiator remaining in the first adhesive layer, the present inventors and others have further studied, As a result, it has been found that by forming the adhesive film storage kit including the specific storage member, it is possible to suppress the curing of the thermosetting composition during storage or transportation, and to maintain the effect of reducing the connection resistance of the adhesive film. .

That is, according to the adhesive film storage kit of one aspect of the present invention, when a compound capable of reacting with a photopolymerization initiator in the photocurable composition is used as the polymerizable compound in the thermosetting composition, it is possible to suppress When the thermosetting composition is cured during storage or transportation of the adhesive film, the effect of reducing the connection resistance of the adhesive film can be maintained. [Effect of the invention]

According to the present invention, it is possible to provide an adhesive film for circuit connection capable of reducing the connection resistance between opposing electrodes of a circuit connection structure and a method for manufacturing the same. Moreover, according to this invention, the manufacturing method of the circuit connection structure body using such an adhesive film can be provided. In addition, according to the present invention, an adhesive film storage kit including such an adhesive film can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In this specification, the upper limit value and the lower limit value that are individually described can be arbitrarily combined. In the present specification, the "(meth) acrylate" means at least one of an acrylate and a corresponding methacrylate. The same applies to other similar expressions such as "(meth) acrylfluorenyl".

<Adhesive Film for Circuit Connection> FIG. 1 is a schematic cross-sectional view showing an adhesive film for circuit connection according to an embodiment. As shown in FIG. 1, the adhesive film 1 for circuit connection (hereinafter also referred to simply as “adhesive film 1”) includes a first adhesive layer 2 and a second adhesive layer 3 laminated on the first adhesive layer 2. .

(First Adhesive Layer) The first adhesive layer 2 contains a cured product (photocured material) of the photocurable composition. The photocurable composition contains (A) a polymerizable compound (hereinafter also referred to as "(A) component"), (B) a photopolymerization initiator (hereinafter also referred to as "(B) component"), and (C) The conductive particles 4 (hereinafter also referred to as "(C) component"). The photocurable composition may further contain (D) a thermosetting resin (hereinafter also referred to as "(D) component") and / or (E) a thermal polymerization initiator (hereinafter also referred to as "(E) component" ). The first adhesive layer 2 can be obtained, for example, by irradiating a layer containing a photocurable composition with light energy to polymerize the component (A) to harden the photocurable composition. That is, the first adhesive layer 2 includes conductive particles 4 and an adhesive component 5 obtained by curing components other than the conductive particles 4 of the photocurable composition. The first adhesive layer 2 may be a cured product obtained by completely curing the photocurable composition, or may be a cured product obtained by partially curing the photocurable composition. That is, the adhesive component 5 may or may not contain the unreacted (A) component and (B) component (and further (D) component and (E) component).

[(A) Component: Polymerizable Compound] The (A) component is, for example, a compound polymerized by a radical, a cation, or an anion generated by irradiation of light (for example, ultraviolet light) with a photopolymerization initiator. (A) A component may be any of a monomer, an oligomer, or a polymer. As the component (A), one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The component (A) has at least one polymerizable group. The polymerizable group is, for example, a group containing a polymerizable unsaturated double bond (ethylene unsaturated bond). From the viewpoints that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent, the polymerizable group is preferably a radical polymerizable group that reacts with a radical. That is, the (A) component is preferably a radical polymerizable compound. Examples of the radical polymerizable group include a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenyl group, a (meth) acrylfluorenyl group, and a maleimide group. The number of polymerizable groups contained in the component (A) may be two or more from the viewpoint of easily obtaining the physical properties and crosslink density required to reduce the connection resistance after polymerization, and suppress the hardening during polymerization. From the viewpoint of shrinkage, the number may be 10 or less. In terms of obtaining a uniform and stable film (first adhesive layer) after light irradiation, it is preferable to suppress curing shrinkage during polymerization. In this embodiment, in order to achieve a balance between crosslinking density and curing shrinkage, in addition to using a polymerizable compound in which the number of polymerizable groups is within the above range, polymerization in which the number of polymerizable groups is outside the above range may be additionally used. Sexual compounds.

Specific examples of the component (A) include a (meth) acrylate compound, a maleimide compound, a vinyl ether compound, an allyl compound, a styrene derivative, an acrylamide derivative, and Nadiq Nadiimide derivatives, natural rubber, isoprene rubber, butyl rubber, nitrile rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, carboxylated nitrile rubber Wait.

Examples of the (meth) acrylate compound include epoxy (meth) acrylate, (poly) urethane (meth) acrylate, methyl (meth) acrylate, and polyether (meth) Acrylate, polyester (meth) acrylate, polybutadiene (meth) acrylate, silicone acrylate, ethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate , 2-hydroxyethyl (meth) acrylate, isopropyl (meth) acrylate, hydroxypropyl (meth) acrylate, isobutyl (meth) acrylate, isobornyl (meth) acrylate, (formyl) (Isopropyl) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate Ester, tetrahydrofurfuryl (meth) acrylate, 2- (meth) acryloxyethyl phosphate, N, N-dimethylaminoethyl (meth) acrylate, N (meth) acrylate, N-dimethylaminopropyl ester, ethylene glycol diacrylate, diethylene glycol diacrylate Acrylates, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polyethylene glycol di (meth) acrylate, polyalkylene glycol di (methyl) ) Acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isotricyanic acid modified difunctional (meth) acrylate, isotricyanic acid modified trifunctional (meth) acrylate, Tricyclodecyl acrylate, dimethylol-tricyclodecane diacrylate, 2-hydroxy-1,3-dipropenyloxypropane, 2,2-bis [4- (propenyloxymethoxy) Phenyl) phenyl] propane, 2,2-bis [4- (propenyloxypolyethoxy) phenyl] propane, 2,2-bis (meth) propenyloxydiethyl phosphate, 2 -(Meth) acryloxyethyl acid phosphate and the like.

Examples of maleimide compounds include 1-methyl-2,4-bismaleimide benzene, N, N'-m-phenylenemaleimide, and N, N'-p-phenylene Maleimide, N, N'-m-toluenebismaleimide, N, N'-4,4-biphenylbismaleimide, N, N'-4,4- (3, 3'-dimethyl-biphenyl) bismaleimide, N, N'-4,4- (3,3'-dimethyldiphenylmethane) bismaleimide, N, N '-4,4- (3,3'-Diethyldiphenylmethane) bismaleimide, N, N'-4,4-diphenylmethanebismaleimide, N, N '-4,4-Diphenylpropane bismaleimide, N, N'-4,4-diphenyl ether bismaleimide, N, N'-3,3-diphenyl fluorene Bismaleimide, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane, 2,2-bis (3-secondbutyl-4-8 (4 -Maleimide phenoxy) phenyl) propane, 1,1-bis (4- (4-maleimide phenoxy) phenyl) decane, 4,4'-cyclohexylene- Bis (1- (4-maleimidoimidophenoxy) -2-cyclohexyl) benzene, 2,2'-bis (4- (4-maleimidoimidophenoxy) phenyl) hexafluoro Propane and so on.

Examples of the vinyl ether compound include diethylene glycol divinyl ether, dipropylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, and trimethylolpropane trivinyl ether.

Examples of the allyl compound include 1,3-diallyl phthalate, 1,2-diallyl phthalate, and triallyl isocyanurate.

The (A) component is preferably a (meth) acrylate compound from the viewpoint that the curing reaction rate and the physical properties after curing are excellent. From the viewpoint of having both cohesive force for reducing connection resistance and elongation for improving the adhesive force and obtaining more excellent adhesive properties, the (A) component may be (poly) urethane (meth) acrylic acid An ester compound (urethane (meth) acrylate compound or polyurethane (meth) acrylate compound). In addition, from the viewpoint of improving cohesion and further reducing connection resistance, the (A) component may be a (meth) acrylate compound having a high Tg skeleton such as a dicyclopentadiene skeleton.

From the viewpoint of achieving a balance between crosslinking density and curing shrinkage, further reducing connection resistance, and improving connection reliability, the component (A) may be a thermoplastic resin such as an acrylic resin, a phenoxy resin, or a polyurethane resin. A compound in which a polymerizable group such as a vinyl group, an allyl group, or a (meth) acrylfluorenyl group is introduced into a terminal or a side chain (for example, a polyurethane (meth) acrylate). In this case, the weight average molecular weight of the component (A) may be 3,000 or more, may be 5,000 or more, and may be 10,000 or more from the viewpoint of excellent balance between the crosslinking density and curing shrinkage. From the viewpoint of excellent compatibility with other components, the weight average molecular weight of the component (A) may be 1 million or less, may be 500,000 or less, or may be 250,000 or less. The weight average molecular weight refers to a value measured using a calibration curve of a standard polystyrene in accordance with conditions described in the examples using a gel-permeation chromatograph (GPC).

As the (meth) acrylate compound, the component (A) is preferably a radically polymerizable compound containing a phosphate ester structure represented by the following general formula (1). In this case, since the bonding strength to the surface of an inorganic substance (metal, etc.) is improved, it is suitable for bonding electrodes (for example, circuit electrodes) to each other. [Chemical 6] In Formula (1), n represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group.

The radically polymerizable compound having a phosphate ester structure can be obtained, for example, by reacting anhydrous phosphoric acid with 2-hydroxyethyl (meth) acrylate. Specific examples of the radically polymerizable compound having a phosphate ester structure include mono (2- (meth) acryloxyethyl) acid phosphate, and bis (2- (meth) acryloxyethyl) Group) acid phosphate and the like.

From the viewpoint of easily obtaining the crosslink density required to reduce the connection resistance and improve the connection reliability, the content of the (A) component may be 5% by mass or more based on the total mass of the photocurable composition. It may be 10% by mass or more, and may also be 20% by mass or more. From the viewpoint of suppressing curing shrinkage during polymerization, the content of the component (A) may be 90% by mass or less, or 80% by mass or less, or 70% by mass based on the total mass of the photocurable composition. %the following.

[(B) Component: Photopolymerization initiator] (B) The component has a structure selected from the group consisting of the structure represented by the following formula (I), the structure represented by the following formula (II), and the following formula (III) At least one structure in a group of structures. [Chemical 7] [Chemical 8] [Chemical 9]

The component (B) may have a plurality of structures represented by the formulae (I) to (III). Multiple structures may be the same as or different from each other. As component (B), one compound may be used alone, or a plurality of compounds may be used in combination.

The component (B) may be light containing a wavelength in a range of 150 nm to 750 nm, preferably light containing a wavelength in a range of 254 nm to 405 nm, and further preferably light containing a wavelength of 365 nm ( For example, ultraviolet light), a photopolymerization initiator (photo radical polymerization initiator, photocation polymerization initiator, or photoanion polymerization initiator) that generates radicals, cations, or anions will reduce the connection resistance. From the viewpoint of further improvement and more excellent connection reliability, and from the viewpoint of easier curing at low temperature and short time, a photoradical polymerization initiator is preferred.

The structure represented by the formula (I) may be an oxime ester structure, a biimidazole structure, or an acridine structure. That is, the component (B) may have at least one structure selected from the group consisting of an oxime ester structure, a biimidazole structure, and an acridine structure as the structure represented by the formula (I).

As the compound having an oxime ester structure, a compound having a structure represented by the following formula (VI) can be preferably used. [Chemical 10] In formula (VI), R ¹¹ , R ^12, and R ¹³ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group including an aromatic hydrocarbon group.

Specific examples of the compound having an oxime ester structure include 1-phenyl-1,2-butanedione-2- (o-methoxycarbonyl) oxime and 1-phenyl-1,2-propanedione 2- (o-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2 -O-Benzylhydrazine oxime, 1,3-diphenylglycerone-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxyglycerone-2- (o-benzoyl) Fluorenyl) oxime, 1,2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (o-benzophenylideneoxime)], ethyl ketone, 1- [9-ethyl- 6- (2-methylbenzylidene) -9H-carbazol-3-yl]-, 1- (o-acetamidooxime) and the like.

Examples of the compound having a biimidazole structure include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-bis (m-methoxy) Phenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer Substance, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-bis (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer and other 2,4,5-triarylimidazole dimers.

Examples of the compound having an acridine structure include 9-phenylacridine, 1,7-bis (9,9'-acridyl) heptane, and the like.

The structure represented by the formula (II) may be, for example, a structure represented by the following formula (IV) or a structure represented by the following formula (V). That is, the component (B) may have at least one structure selected from the group consisting of a structure represented by the following formula (IV) and a structure represented by the following formula (V) as the formula (II). Structure. From the viewpoint of further improving the connection resistance reduction effect and more excellent connection reliability, the component (B) preferably has at least at least a structure represented by the following formula (IV) and a structure represented by the following formula (V). One. [Chemical 11] In formula (IV), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. [Chemical 12]

The structure represented by the formula (II) may be an α-aminobenzoyl ketone structure, an amine benzophenone structure, or an N-phenylglycine structure. That is, the component (B) may have at least one structure selected from the group consisting of an α-aminobenzoyl ketone structure, an amino benzophenone structure, and an N-phenylglycine structure.

As the compound having an α-aminobenzoyl ketone structure, a compound having a structure represented by the following formula (VII) can be preferably used. [Chemical 13] In formula (VII), R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an organic group containing an aromatic hydrocarbon group, A functional group of the structure represented or a functional group containing a structure represented by the formula (V). At least one of R ²² , R ²³ and R ²⁴ is a functional group containing a structure represented by the formula (IV) or a functional group containing a structure represented by the formula (V).

Specific examples of the compound having an α-aminobenzoyl ketone structure include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinylpropane-1-one, 2 -Benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -butanone-1 and the like.

Examples of the compound having an aminobenzophenone structure include 4,4'-bis (dimethylamino) benzophenone, and 4,4'-bis (diethylamino) benzophenone. , 4-methoxy-4'-dimethylaminobenzophenone and the like.

Examples of the compound having an N-phenylglycine structure include N-phenylglycine.

The structure represented by the formula (III) may be a fluorenylphosphine oxide structure. That is, the (B) component may have a fluorenyl phosphine oxide structure as a structure represented by said Formula (III).

As the compound having a fluorenylphosphine oxide structure, a compound having a structure represented by the following formula (VIII) can be preferably used. [Chemical 14] In formula (VIII), R ³¹ , R ^32, and R ³³ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing a carbonyl group or an aromatic hydrocarbon group.

Specific examples of the compound having a fluorenylphosphine oxide structure include bis (2,6-dimethoxybenzylidene) -2,4,4-trimethyl-pentylphosphine oxide, and bis (2 , 4,6-trimethylbenzylidene) -phenylphosphine oxide, 2,4,6-trimethylbenzylidene-diphenyl-phosphine oxide, and the like.

From the viewpoint of further improving the connection resistance reduction effect and more excellent connection reliability, the component (B) preferably has a composition selected from the group consisting of an oxime ester structure, an α-aminophenanone structure, and a fluorenyl phosphine oxide structure. At least one structure in the group.

From the viewpoint of excellent fast curing properties, and further improvement of connection resistance reduction effect and more excellent connection reliability, the content of the (B) component is preferably 0.1 mass based on the total mass basis of the photocurable composition. % Or more, more preferably 0.3% by mass or more. The content of the component (B) may be 1% by mass or more, 1.5% by mass or more, 2% by mass or more, or 2.5% by mass or more based on the total mass of the photocurable composition. From the viewpoint of improvement in storage stability, further improvement in connection resistance reduction effect, and more excellent connection reliability, the content of the component (B) is preferably 15 mass based on the total mass of the photocurable composition. % Or less, more preferably 10% by mass or less, still more preferably 5% by mass or less. The content of the component (B) may be 3.5 mass% or less, 3 mass% or less, 2.5 mass% or less, 2 mass% or less, 1.5 mass% or less, 1 mass% or less based on the total mass of the photocurable composition. 0.7 mass% or less. From these viewpoints, the content of the component (B) is preferably from 0.1% by mass to 15% by mass, more preferably from 0.1% by mass to 10% by mass based on the total mass of the photocurable composition. 0.3 mass% to 5 mass%. The content of the component (B) may be, for example, 0.1% by mass to 1% by mass, 0.3% by mass to 0.7% by mass, 1.5% by mass to 3.5% by mass, or 2% by mass based on the total mass of the photocurable composition. ～ 3% by mass.

[(C) component: conductive particles] The (C) component is not particularly limited as long as it is conductive particles, and may be metal particles containing metals such as Au, Ag, Ni, Cu, and solder; conductive materials containing conductive carbon Carbon particles and so on. (C) The component may also be coated conductive particles including a core and a covering layer of a covering core, the core including non-conductive glass, ceramic, plastic (polystyrene, etc.), etc., the covering layer including the metal or Conductive carbon. Among these, coated conductive particles including a core including a metal particle or a plastic formed of a hot-melt metal, and a coating layer including a metal or conductive carbon can be preferably used. In this case, it is easy to deform the hardened material of the photocurable composition by heating or pressing. When the electrodes are electrically connected to each other, the contact area between the electrode and the (C) component can be increased, and the The conductivity is further improved.

The component (C) may be an insulating coated conductive particle including the metal particle, the conductive carbon particle, or the coated conductive particle, and an insulating layer that includes an insulating material such as a resin and covers the surface of the particle. If the (C) component is an insulating-coated conductive particle, even when the content of the (C) component is large, the surface of the particle is covered with a resin, so that short circuits caused by contact between the (C) components can be suppressed, and It also improves the insulation between adjacent electrode circuits. The component (C) may be used singly or in combination of two or more of the various conductive particles described above.

(C) The maximum particle diameter of the component needs to be smaller than the minimum distance between electrodes (the shortest distance between adjacent electrodes). From the viewpoint of excellent dispersibility and electrical conductivity, the maximum particle diameter of the component (C) may be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more. From the viewpoint of excellent dispersibility and electrical conductivity, the maximum particle diameter of the component (C) may be 50 μm or less, 30 μm or less, or 20 μm or less. In this specification, the particle size of arbitrary 300 conductive particles (pcs) is measured by observation with a scanning electron microscope (SEM), and the maximum value obtained is defined as the (C) component. Maximum particle size. When the (C) component is not spherical, the particle size of the (C) component is set to the diameter of a circle circumscribed with the conductive particles in the SEM image.

From the viewpoint of excellent dispersibility and electrical conductivity, the average particle diameter of the component (C) may be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more. From the viewpoint of excellent dispersibility and electrical conductivity, the average particle diameter of the component (C) may be 50 μm or less, 30 μm or less, or 20 μm or less. In this specification, the particle size of arbitrary 300 conductive particles (pcs) is measured by observation with a scanning electron microscope (SEM), and the average value of the obtained particle diameters is the average particle diameter.

In the first adhesive layer 2, it is preferable that the component (C) is uniformly dispersed. From the viewpoint of easily obtaining a stable connection resistance, the particle density of the component (C) in the first adhesive layer 2 may be 100 pcs / mm ² or higher, or 1,000 pcs / mm ² or higher, or 2000 pcs / mm ² or more. From the viewpoint of improving the insulation between adjacent electrodes, the particle density of the component (C) in the first adhesive layer 2 may be 100,000 pcs / mm ² or less, or 50,000 pcs / mm ² or less. It is below 10000 pcs / mm ² .

From the viewpoint of further improving the conductivity, the content of the component (C) may be 0.1% by volume or more, or 1% by volume or more, based on the total volume of the first adhesive layer. %the above. From the viewpoint of easily suppressing short circuits, the content of the component (C) may be 50% by volume or less, 30% by volume or less, and 20% by volume or less based on the total volume of the first adhesive layer. . The content of the component (C) based on the total volume of the photocurable composition may be the same as the above range.

[(D) Component: Thermosetting resin] The (D) component is a resin that is hardened by heat, and has at least one or more thermosetting groups. The component (D) is, for example, a compound that reacts with a hardener by heat and crosslinks accordingly. As the component (D), one compound may be used alone, or a plurality of compounds may be used in combination.

From the viewpoint of further improving the connection resistance reduction effect and further improving the connection reliability, the thermosetting group may be, for example, an epoxy group or an oxetanyl group.

Specific examples of the component (D) include bisphenol-type epoxy resins that are reaction products of epichlorohydrin and bisphenol A, bisphenol F, bisphenol AD, and the like; and epichlorohydrin and phenol novolac, cresol Epoxy novolac resins of reaction products such as novolac; naphthalene-based epoxy resins having a naphthalene ring-containing skeleton; various epoxy compounds having two or more glycidyl groups in one molecule such as glycidylamine and glycidyl ether And so on.

The content of the component (D) may be 30% by mass or more and 70% by mass or less based on the total mass of the first adhesive layer.

When the first adhesive layer contains a thermosetting resin, the first adhesive layer may further contain a curing agent for curing the thermosetting resin. The hardener is not particularly limited as long as it is a hardener that generates cationic species by heat, and can be appropriately selected depending on the purpose. Examples of the hardener include sulfonium salts and sulfonium salts. The content of the hardener may be, for example, 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the thermosetting resin.

[(E) component: thermal polymerization initiator] (E) component may be a thermal polymerization initiator (thermal radical polymerization initiator, thermal cationic polymerization initiator) that generates radicals, cations, or anions by heat. Or thermal anionic polymerization initiator), from the viewpoint of further improving the effect of reducing the connection resistance and more excellent connection reliability, a thermal radical polymerization initiator is preferred. As the component (E), one compound may be used alone, or a plurality of compounds may be used in combination.

The thermal radical polymerization initiator is decomposed by heat to generate free radicals. That is, a thermal radical polymerization initiator is a compound which generates a radical by giving thermal energy from the outside. The thermal radical polymerization initiator can be arbitrarily selected from conventionally known organic peroxides and azo compounds. From the viewpoints of stability, reactivity, and compatibility, an organic peroxide having a one-minute half-life temperature of 90 ° C to 175 ° C and a weight average molecular weight of 180 to 1,000 can be preferably used as the thermal radical polymerization initiator. . When the 1-minute half-life temperature is in this range, the storage stability is more excellent, and the radical polymerizability is also high enough to be hardened in a short time.

Specific examples of the component (E) include neodecanoic acid-1,1,3,3-tetramethylbutylperoxide, bis (4-thirdbutylcyclohexyl) dicarbonate, and peroxydidecanoate. Di (2-ethylhexyl) dioxycarbonate, cumyl peroxyneodecanoate, dilauryl peroxide, neocyclodecyl peroxy-1-cyclohexyl-1-methylethyl ester, neodecyl peroxide Tert-hexyl acid, tert-butyl peroxydecanoate, tert-butyl peroxytrimethylacetate, 2-ethylhexanoate-1,1,3,3-tetramethylbutyl peroxy , 2,5-dimethyl-2,5-bis (2-ethylhexylperoxy) hexane, 2-ethylhexanoic acid-tertiary hexyl ester, 2-ethyl peroxide Tertiary butyl hexanoate, tertiary butyl perpeptanoate, tertiary pentyl peroxy-2-ethylhexanoate, di-tertiary butyl hexahydrophthalate, peroxy-3 , 3,5-Trimethylhexanoic acid third amyl ester, neodecanoic acid-3-hydroxy-1,1-dimethylbutyl ester, neodecanoic acid triamyl ester, peroxy-2 -Thirty-pentyl ethylhexanoate, bis (3-methylbenzidine) peroxide, bis (benzidine) peroxide, bis (4-methylbenzidine) peroxide, isopropyl monocarbonate third Ester, tert-butyl peroxymaleate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, 2,5-dimethyl-2, 5-bis (3-methylbenzylideneperoxy) hexane, tert-butyl peroxy-2-ethylhexyl monocarbonate, tert-hexyl peroxybenzoate, 2,5-dimethyl- 2,5-Di (benzylidene peroxy) hexane, tert-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, tert-amyl peroxyoctanoate, isononyl peroxide Organic peroxides such as triamyl ester, triamyl peroxybenzoate; 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis (1- Ethyloxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 4,4'-azobis Azo compounds such as (4-cyanovaleric acid) and 1,1'-azobis (1-cyclohexanecarbonitrile).

From the viewpoint of further improving the connection resistance reduction effect and more excellent connection reliability, the content of the (E) component may be 0.1% by mass or more based on the total mass of the first adhesive layer, and may also be 0.5% by mass. The above may be 1% by mass or more. From the viewpoint of pot life, the content of the (E) component may be 20% by mass or less, or 10% by mass or less, based on the total mass of the first adhesive layer. %the following. The first adhesive layer 2 may not contain (E) component. The content of the (E) component based on the total mass of the photocurable composition may be the same as the above range.

[Other components] The photocurable composition may further contain components other than (A) component, (B) component, (C) component, (D) component, and (E) component. Examples of the other components include a photopolymerization initiator other than the component (B), a thermoplastic resin, a coupling agent, a filler, and the hardener. These components may be contained in the first adhesive layer 2.

Examples of the photopolymerization initiator other than the component (B) include a photopolymerization initiator having a benzophenone dimethyl ketal structure, and a photopolymerization initiator having an α-hydroxybenzophenone structure. The content of the photopolymerization initiator other than the component (B) may be, for example, 1 part by mass or more and 1000 parts by mass or less with respect to 100 parts by mass of the component (B).

Examples of the thermoplastic resin include a phenoxy resin, a polyester resin, a polyamide resin, a polyurethane resin, a polyester urethane resin, and an acrylic rubber. When the photocurable composition contains a thermoplastic resin, the first adhesive layer can be easily formed. In addition, when the photocurable composition contains a thermoplastic resin, it is possible to reduce the stress of the first adhesive layer generated when the photocurable composition is cured. Moreover, when a thermoplastic resin has a functional group, such as a hydroxyl group, the adhesiveness of a 1st adhesive layer is easy to improve. The content of the thermoplastic resin may be, for example, 5% by mass or more and 80% by mass or less based on the total mass of the photocurable composition.

Examples of the coupling agent include a silane coupling agent having an organic functional group such as a (meth) acrylfluorenyl group, a mercapto group, an amine group, an imidazolyl group, or an epoxy group; a silane compound such as a tetraalkoxysilane; and a tetraalkoxytitanic acid Ester derivatives, polydialkyl titanate derivatives, and the like. When the photocurable composition contains a coupling agent, adhesion can be further improved. The content of the coupling agent may be, for example, 0.1% by mass or more and 20% by mass or less based on the total mass of the photocurable composition.

Examples of the filler include non-conductive fillers (for example, non-conductive particles). When the photocurable composition contains a filler, further improvement in connection reliability can be expected. The filler may be either an inorganic filler or an organic filler. Examples of the inorganic filler include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titania particles, and zirconia particles; and inorganic particles such as nitride particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate-butadiene-styrene fine particles, acrylic-silicone fine particles, polyamide fine particles, and polyimide fine particles. These fine particles may have a uniform structure or may have a core-shell type structure. The maximum diameter of the filler is preferably smaller than the minimum particle diameter of the conductive particles 4. The content of the filler may be, for example, 1% by volume or more and 30% by volume or less based on the total volume of the photocurable composition.

The photocurable composition may contain other additives such as a softener, an accelerator, a deterioration inhibitor, a colorant, a flame retardant, and a thixotropic agent. The content of these additives may be, for example, 0.1% by mass to 10% by mass based on the total mass of the photocurable composition. These additives may be contained in the first adhesive layer 2.

The first adhesive layer 2 may contain components derived from a photocurable composition such as unreacted component (A) and component (B). It is presumed that when the adhesive film 1 of this embodiment is stored in an existing storage member for storage and transportation, the unreacted (B) component remains in the first adhesive layer 2 and is therefore stored and transported. In part, a part of the thermosetting composition in the second adhesive layer 3 is hardened, and the effect of reducing the connection resistance of the adhesive film 1 is reduced. Therefore, in a case where the first adhesive layer 2 contains the component (B), the adhesive film 1 is accommodated in a storage member described later, thereby preventing a reduction in the effect of reducing the connection resistance. From the viewpoint that it is difficult to cause hardening of the thermosetting composition and sufficiently reduce the connection resistance, the content of the (B) component in the first adhesive layer 2 may be based on the total mass of the first adhesive layer. It is 15 mass% or less, 10 mass% or less, and 5 mass% or less. The content of the component (B) in the first adhesive layer 2 may be 0.1% by mass or more based on the total mass of the first adhesive layer.

The thickness d1 of the first adhesive layer 2 may be 0.2 times or more the average particle diameter of the conductive particles 4 and may be 0.3 times or more from the viewpoint that the conductive particles 4 are easily captured between the opposing electrodes and the connection resistance can be further reduced. . From the viewpoint that when conductive particles are sandwiched between opposing electrodes during thermocompression, the conductive particles are more easily broken and the connection resistance can be further reduced, the thickness d1 of the first adhesive layer 2 may be the average particle diameter of the conductive particles 4 0.8 times or less, and 0.7 times or less. From these viewpoints, the thickness d1 of the first adhesive layer 2 may be 0.2 to 0.8 times or 0.3 to 0.7 times the average particle diameter of the conductive particles 4. In a case where the thickness d1 of the first adhesive layer 2 and the average particle diameter of the conductive particles 4 satisfy the relationship described above, for example, as shown in FIG. 1, a part of the conductive particles 4 in the first adhesive layer 2 may be It protrudes from the 1st adhesive layer 2 to the 2nd adhesive layer 3 side. In this case, the boundary S between the first adhesive layer 2 and the second adhesive layer 3 is located at a spaced portion between the adjacent conductive particles 4 and the conductive particles 4. The conductive particles 4 may not be exposed on the surface 2 a on the opposite side of the first adhesive layer 2 from the second adhesive layer 3 side, and the surface 2 a on the opposite side may be a flat surface.

The thickness d1 of the first adhesive layer 2 can be appropriately set according to the electrode height and the like of the circuit member to be attached. The thickness d1 of the first adhesive layer 2 may be, for example, 0.5 μm or more, and may be 20 μm or less. When a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 2 (for example, it protrudes to the second adhesive layer 3 side), the first adhesive layer 2 and the second adhesive layer 3 are exposed. The distance from the surface 2a on the opposite side to the boundary S between the first adhesive layer 2 and the second adhesive layer 3 located in the adjacent conductive particles 4 and the separated portions of the conductive particles 4 (indicated by d1 in FIG. 1) Distance) is the thickness of the first adhesive layer 2, and the exposed portion of the conductive particles 4 is not included in the thickness of the first adhesive layer 2. The length of the exposed portion of the conductive particles 4 may be, for example, 0.1 μm or more, and may be 20 μm or less.

(Second Adhesive Layer) The second adhesive layer 3 contains, for example, (a) a polymerizable compound (hereinafter also referred to as (a) component) and (b) a thermal polymerization initiator (hereinafter also referred to as (b) component) ) Thermosetting composition. The thermosetting composition constituting the second adhesive layer 3 is a thermosetting composition that can flow during circuit connection, and is, for example, an uncured thermosetting composition.

[(A) Component: Polymerizable Compound] The (a) component is, for example, a compound polymerized by a radical, cation, or anion generated by heat with a thermal polymerization initiator. As (a) component, the compound exemplified as (A) component can be used. From the viewpoint of easy connection at low temperature and short time, further reduction of connection resistance, and better connection reliability, the component (a) is preferably a radical having a radical polymerizable group that reacts with a radical. Polymerizable compound. Examples of preferable radical polymerizable compounds in the component (a) and combinations of preferable radical polymerizable compounds are the same as the component (A). When the component (a) is a radical polymerizable compound and the component (B) in the first adhesive layer is a photoradical polymerization initiator, the adhesive film is stored in a storage member described later, and there is The tendency of the thermosetting composition to harden during storage or transportation of the adhesive film is significantly suppressed.

(A) A component may be any of a monomer, an oligomer, or a polymer. As component (a), a single compound may be used alone, or a plurality of compounds may be used in combination. The component (a) may be the same as or different from the component (A).

From the viewpoint of easily obtaining the crosslink density required to reduce the connection resistance and improve the connection reliability, the content of the component (a) may be 10% by mass or more based on the total mass of the thermosetting composition. It may be 20% by mass or more, or 30% by mass or more. From the viewpoint of suppressing curing shrinkage during polymerization and obtaining good reliability, the content of the component (a) may be 90% by mass or less based on the total mass of the thermosetting composition, and may also be 80% by mass. Below, it may be 70% by mass or less.

[Component (b): Thermal polymerization initiator] As the component (b), the same thermal polymerization initiator as the component (E) can be used. As component (b), a single compound may be used alone, or a plurality of compounds may be used in combination. The component (b) is preferably a thermal radical polymerization initiator. Examples of the preferable thermal radical polymerization initiator in the component (b) are the same as the component (E).

From the viewpoint of further improving the connection resistance reduction effect and further improving the connection reliability, based on the total mass of the thermosetting composition, the content of the component (b) may be 0.1% by mass or more, and may also be 0.5% by mass. The above may be 1% by mass or more. From the viewpoint of the pot life, the content of the component (b) may be 30% by mass or less, 20% by mass or less, and 10% by mass or less based on the total mass of the thermosetting composition.

[Other components] The thermosetting composition may further contain components other than (a) component and (b) component. Examples of the other components include thermoplastic resins, coupling agents, fillers, softeners, accelerators, deterioration inhibitors, colorants, flame retardants, and thixotropic agents. The details of the other components are the same as those of the other components in the first adhesive layer 2.

The thermosetting composition may contain the same thermosetting resin as the component (D) described above in place of the components (a) and (b), or may contain components other than (a) and (b). The thermosetting resin having the same component (D) as described above. In this case, the thermosetting composition may contain a hardening agent for curing the thermosetting resin as described above. When a thermosetting resin is used in place of the components (a) and (b), for example, based on the total mass of the thermosetting composition, the content of the thermosetting resin in the thermosetting composition may be 20 It may be 80% by mass or more. When the thermosetting resin is used in addition to the components (a) and (b), for example, based on the total mass of the thermosetting composition, the content of the thermosetting resin in the thermosetting composition may be 20% by mass or more and 80% by mass or less. The content of the curing agent may be the same as the range described as the content of the curing agent in the photocurable composition.

The content of the conductive particles 4 in the second adhesive layer 3 may be, for example, 1% by mass or less based on the total mass of the second adhesive layer, and may also be 0% by mass. The second adhesive layer 3 is preferably free of conductive particles 4.

The thickness d2 of the second adhesive layer 3 can be appropriately set according to the electrode height and the like of the circuit member to be attached. The thickness d2 of the second adhesive layer 3 may be 5 μm or more and 200 μm or less from the viewpoint of sufficiently filling the space between the electrodes to seal the electrodes and obtaining better connection reliability. When a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 2 (for example, it protrudes to the second adhesive layer 3 side), the second adhesive layer 3 and the first adhesive layer 2 are exposed. The distance from the surface 3a on the opposite side to the boundary S between the first adhesive layer 2 and the second adhesive layer 3 located in the adjacent conductive particles 4 and the separated portion of the conductive particles 4 (indicated by d2 in FIG. 1 Distance) is the thickness of the second adhesive layer 3.

The ratio of the thickness d1 of the first adhesive layer 2 to the thickness d2 of the second adhesive layer 3 (the first adhesive The thickness d1 of the agent layer 2 / the thickness d2 of the second adhesive layer 3 may be 1 or more, and may be 100 or less.

The thickness of the adhesive film 1 (total thickness of all layers constituting the adhesive film 1; in FIG. 1, the total of the thickness d1 of the first adhesive layer 2 and the thickness d2 of the second adhesive layer 3) may be, for example, 5 μm or more, and may be 200 μm or less.

In the adhesive film 1, the conductive particles 4 are dispersed in the first adhesive layer 2. Therefore, the adhesive film 1 is an anisotropic conductive adhesive film having an anisotropic conductivity. The adhesive film 1 is used between the first circuit member having the first electrode and the second circuit member having the second electrode, and the first circuit member and the second circuit member are thermally compression-bonded so that the first circuit member The first electrode and the second electrode are electrically connected to each other.

According to the adhesive film 1, the connection resistance between the opposing electrodes can be reduced, and the connection reliability can be improved. The reason why such an effect can be obtained is not clear, and the present inventors and others speculated as follows. First, in the adhesive film 1, since the conductive particles 4 are fixed by the cured product of the photocurable composition, the flow of the conductive particles 4 during connection can be suppressed. Therefore, the capturing efficiency of the conductive particles 4 in the electrode can be improved. Furthermore, in this embodiment, the photopolymerization initiator has at least one structure among the structures represented by said Formula (I)-Formula (III). With this photopolymerization initiator, the reactivity of the resin (for example, the reactivity of the resin near the conductive particles) changes, and the crosslinked state and surface state of the resin change, thereby making it easy to obtain conductive particles during compression bonding. The surface is in contact with the electrode surface. Therefore, in this embodiment, the connection resistance can be reduced compared with the case where a photopolymerization initiator having no structure represented by the formulae (I) to (III) is used. For the reasons as described above, the present inventors and others estimated that the above effects can be obtained.

As mentioned above, although the adhesive film for circuit connection of this embodiment was demonstrated, this invention is not limited to the said embodiment.

For example, the adhesive film for circuit connection may include two layers including the first adhesive layer and the second adhesive layer, or may include a layer other than the first adhesive layer and the second adhesive layer (for example, the third adhesive layer). Agent layer) contains three or more layers. The third adhesive layer may be a layer having the same composition as that described above with respect to the first adhesive layer or the second adhesive layer, or may have a composition similar to that described above with respect to the first adhesive layer or the second adhesive layer. The layer is the same thickness as the layer. The adhesive film for circuit connection may further include a third adhesive layer on the surface of the first adhesive layer opposite to the second adhesive layer, for example. That is, the adhesive film for circuit connection is laminated | stacked in the order of a 2nd adhesive layer, a 1st adhesive layer, and a 3rd adhesive layer, for example. In this case, the third adhesive layer contains, for example, a thermosetting composition similarly to the second adhesive layer.

In addition, the adhesive film for circuit connection of the embodiment is an anisotropic conductive adhesive film having anisotropic conductivity, but the adhesive film for circuit connection may be conductive without anisotropic conductivity. Adhesive film.

<Method for Manufacturing Adhesive Film for Circuit Connection> The method for manufacturing the adhesive film 1 for circuit connection in this embodiment includes, for example, a preparation step (first preparation step) for preparing the first adhesive layer 2 described above; and The step of laminating the second adhesive layer 3 described above on the first adhesive layer 2. The method for manufacturing the adhesive film 1 for circuit connection may further include a preparation step (a second preparation step) for preparing the second adhesive layer 3.

In the first preparation step, for example, a first adhesive layer 2 is formed on a substrate to obtain a first adhesive film, thereby preparing the first adhesive layer 2. Specifically, first add other components such as (A) component, (B) component and (C) component, and (D) component and (E) component added to an organic solvent as needed, and mix and mix by stirring The varnish composition is prepared by dissolving or dispersing in a mill or the like. Then, the varnish composition is applied to the substrate subjected to the mold release treatment by using a doctor blade coater, a roll coater, an applicator, a notch wheel coater, a die coater, or the like, and then heated by heating. The organic solvent is volatilized to form a layer containing a photocurable composition on the substrate. Then, the photocurable composition is cured by irradiating the layer containing the photocurable composition with light to form a first adhesive layer 2 on the substrate (curing step). Thus, a first adhesive film was obtained.

The organic solvent used in the preparation of the varnish composition is preferably one having the property of uniformly dissolving or dispersing each component. Examples include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetic acid. Ethyl acetate, propyl acetate, butyl acetate, and the like. These organic solvents may be used alone or in combination of two or more. Stirring, mixing, and kneading in the preparation of the varnish composition can be performed using, for example, a mixer, a mill, a three-roller, a ball mill, a bead mill, or a homogenizer.

The substrate is not particularly limited as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized. For example, oriented polypropylene (OPP), polyethylene terephthalate ( polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, poly Base materials (such as films) such as amine, polyimide, cellulose, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, and liquid crystal polymer.

The heating conditions when the organic solvent is volatilized from the varnish composition applied to the substrate is preferably a condition that the organic solvent is sufficiently volatilized. The heating conditions may be, for example, 40 ° C. or higher and 120 ° C. or lower, and 0.1 minute or longer and 10 minutes or shorter.

In the irradiation of light in the curing step, it is preferable to use irradiation light (for example, ultraviolet light) including a wavelength in a range of 150 nm to 750 nm. Light irradiation can be performed using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a light emitting diode (LED) light source, or the like. The irradiation amount of light is not particularly limited, and may be, for example, 0.01 J / cm ² to 10 J / cm ² as a cumulative light amount of light having a wavelength of 365 nm.

In the second preparation step, a second adhesive is formed on the substrate in the same manner as in the first preparation step, except that the components (a) and (b), other components added as necessary, and no light irradiation are used. Layer 3 to obtain a second adhesive film, thereby preparing a second adhesive layer 3.

In the laminating step, the second adhesive layer 3 can be laminated on the first adhesive layer 2 by laminating the first adhesive film and the second adhesive film, or can be applied by the first adhesive layer 2 The cloth uses a varnish composition obtained by using the component (a) and the component (b) and other components added as necessary, and the organic solvent is volatilized to laminate the second adhesive layer 3 on the first adhesive layer 2.

Examples of a method for bonding the first adhesive film to the second adhesive film include methods such as heat pressing, roll lamination, and vacuum lamination. Lamination can be performed, for example, at a temperature of 0 ° C to 80 ° C.

<Circuit connection structure and its manufacturing method> Hereinafter, the circuit connection structure using the above-mentioned circuit connection adhesive film 1 as a circuit connection material, and its manufacturing method are demonstrated.

FIG. 2 is a schematic cross-sectional view showing a circuit connection structure according to an embodiment. As shown in FIG. 2, the circuit connection structure 10 includes a first circuit member 13 including a first circuit substrate 11 and a first electrode 12 formed on a main surface 11 a of the first circuit substrate 11; and a second circuit substrate 14 And the second circuit member 16 of the second electrode 15 formed on the main surface 14 a of the second circuit board 14; and the first electrode 12 and the second electrode 16 are arranged between the first circuit member 13 and the second circuit member 16. The electrodes 15 are electrically connected to the circuit connection portion 17.

The first circuit member 13 and the second circuit member 16 may be the same as or different from each other. The first circuit member 13 and the second circuit member 16 may be a glass substrate or a plastic substrate on which electrodes are formed, a printed wiring board, a ceramic wiring board, a flexible wiring board, a semiconductor silicon IC chip, and the like. The first circuit substrate 11 and the second circuit substrate 14 may include inorganic substances such as semiconductors, glass, and ceramics, organic substances such as polyimide, polycarbonate, and composites such as glass / epoxy. The first electrode 12 and the second electrode 15 may include gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, indium tin oxide (ITO), and indium. Indium Zinc Oxide (IZO), Indium Gallium Zinc Oxide (IGZO), etc. The first electrode 12 and the second electrode 15 may be circuit electrodes or bump electrodes. At least one of the first electrode 12 and the second electrode 15 may be a bump electrode. In FIG. 2, the second electrode 15 is a bump electrode.

The circuit connection part 17 contains the hardened | cured material of the adhesive film 1 mentioned above. The circuit connection portion 17 includes, for example, a first region 18 on the side of the first circuit member 13 in a direction in which the first circuit member 13 and the second circuit member 16 face each other (hereinafter referred to as "opposing direction"), and includes the light described above A hardened product of components such as (A) component and (B) component other than conductive particles 4 of the curable composition; the second region 19 is located on the side of the second circuit member 16 in the opposite direction, and contains the component (a), ( b) a hardened body of the above-mentioned thermosetting composition such as a component; and conductive particles 4 interposed between at least the first electrode 12 and the second electrode 15 to electrically electrically connect the first electrode 12 and the second electrode 15 to each other. Sexual connection. The circuit connection portion does not need to have two regions like the first region 18 and the second region 19, and may include, for example, a hardened product of components other than the conductive particles 4 of the photocurable composition described above and the above-mentioned thermal curing The hardened material of the sexual composition is a mixed hardened material.

3 (a) and 3 (b) are schematic cross-sectional views showing a method of manufacturing the circuit connection structure 10. As shown in FIGS. 3 (a) and 3 (b), the method for manufacturing the circuit connection structure 10 includes, for example, the following steps: the above-mentioned adhesive film 1 is interposed between the first circuit member 13 having the first electrode 12 The first circuit member 13 and the second circuit member 16 are thermocompression-bonded with the second circuit member 16 having the second electrode 15 to electrically connect the first electrode 12 and the second electrode 15 to each other.

Specifically, as shown in FIG. 3 (a), first, a first circuit member 13 having a first circuit substrate 11 and a first electrode 12 formed on a main surface 11 a of the first circuit substrate 11, and a first circuit member 13 The second circuit board 14 and the second circuit member 16 of the second electrode 15 formed on the main surface 14 a of the second circuit board 14.

Next, the first circuit member 13 and the second circuit member 16 are disposed so that the first electrode 12 and the second electrode 15 face each other, and the adhesive film 1 is disposed between the first circuit member 13 and the second circuit member 16. For example, as shown in FIG. 3 (a), the adhesive film 1 is laminated on the first circuit member 13 so that the first adhesive layer 2 side faces the mounting surface 11 a of the first circuit member 13. Next, a second circuit is arranged on the first circuit member 13 on which the adhesive film 1 is laminated so that the first electrode 12 on the first circuit substrate 11 and the second electrode 15 on the second circuit substrate 14 face each other. Component 16.

Then, as shown in FIG. 3 (b), the first circuit member 13 and the second circuit member 16 are pressed in the thickness direction while heating the first circuit member 13, the adhesive film 1, and the second circuit member 16. Thereby, the first circuit member 13 and the second circuit member 16 are thermocompression-bonded to each other. At this time, as shown by an arrow in FIG. 3 (b), the second adhesive layer 3 contains a non-hardened thermosetting composition that can flow, so that the gap between the second electrode 15 and the second electrode 15 is filled. The pattern flows and is hardened by the heating. Thereby, the first electrode 12 and the second electrode 15 are electrically connected to each other with the conductive particles 4 interposed therebetween, and the first circuit member 13 and the second circuit member 16 are bonded to each other to obtain a circuit connection structure shown in FIG. 2. 10. In the method of manufacturing the circuit connection structure 10 according to this embodiment, the first adhesive layer 2 is a layer that is hardened in advance. Therefore, the conductive particles 4 are fixed to the first adhesive layer 2. In addition, the first adhesive layer 2 is disposed on the substrate. During the thermocompression bonding, there is almost no flow, and the conductive particles are efficiently captured between the opposed electrodes, so that the connection resistance between the opposed electrodes 12 and 15 can be reduced. Therefore, a circuit connection structure having excellent connection reliability can be obtained.

<Adhesive film storage kit> FIG. 4 is a perspective view showing an adhesive film storage kit according to an embodiment. As shown in FIG. 4, the adhesive film storage kit 20 includes an adhesive film for circuit connection 1, a reel 21 around which the adhesive film 1 is wound, and a storage member 22 that accommodates the adhesive film 1 and the reel 21.

As shown in FIG. 4, the adhesive film 1 is, for example, a strip. The strip-shaped adhesive film 1 is produced, for example, by cutting the entire sheet-shaped sheet into a strip shape with a width according to the application. A substrate may be provided on one surface of the adhesive film 1. As the substrate, a substrate such as a PET film described above can be used.

The reel 21 includes a first side plate 24 having a winding core 23 around which the adhesive film 1 is wound, and a second side plate 25 disposed so as to face the first side plate 24 with the winding core 23 interposed therebetween.

The first side plate 24 is, for example, a circular plate made of plastic, and a central portion of the first side plate 24 is provided with an opening having a circular cross section.

The winding core 23 included in the first side plate 24 is a portion where the adhesive film 1 is wound. The core 23 includes, for example, plastic, and is formed in a ring shape having the same thickness as the width of the adhesive film 1. The core 23 is fixed to the inner surface of the first side plate 24 so as to surround the opening of the first side plate 24. A shaft hole 26 is provided in a central portion of the reel 21 as a part into which a rotation shaft of a winding device or an output device (not shown) is inserted. When the rotating shaft is driven in a state where the rotating shaft of the winding device or the output device is inserted into the shaft hole 26, the winding shaft 21 rotates without idling. A desiccant storage container for storing a desiccant may be embedded in the shaft hole 26.

Like the first side plate 24, the second side plate 25 is, for example, a circular plate made of plastic, and a central circular portion is provided with a circular cross-sectional opening portion having the same diameter as the opening portion of the first side plate 24.

The storage member 22 has, for example, a bag shape, and stores the adhesive film 1 and the reel 21. The storage member 22 includes an insertion port 27 for storing (inserting) the adhesive film 1 and the reel 21 into the storage member 22.

The storage member 22 includes a viewing portion 28 that allows the inside of the storage member 22 to be viewed from the outside. The storage member 22 shown in FIG. 4 is configured so that the entire storage member 22 becomes the viewing portion 28.

The visual recognition portion 28 has transmissivity to visible light. For example, when measuring the light transmittance of the visual inspection portion 28 in the range of 450 nm to 750 nm, the average value of the transmittance of at least one light between the wavelengths of 450 nm to 750 nm is 30% or more and the wavelength width is 50 nm area. The light transmittance of the visual inspection portion 28 can be obtained by preparing a sample obtained by cutting the visual inspection portion 28 into a predetermined size, and measuring the light transmittance of the sample using an ultraviolet-visible spectrophotometer. Since the storage member 22 has such a viewing portion 28, various information such as a product name, a batch number, and an expiration date attached to the reel 21 can also be confirmed from the outside of the storage member 22. With this, it is expected to prevent the wrong product from being mixed in and improve the efficiency of the classification operation.

The visible portion 28 has a transmittance of 10% or less for light having a wavelength of 365 nm. The visible portion 28 has a transmittance of 10% or less for light having a wavelength of 365 nm. Therefore, it is possible to suppress the light incident from the outside of the housing member 22 to the inside and the photopolymerization initiator remaining in the first adhesive layer 2. Curing of thermosetting composition. As a result, the effect of reducing the connection resistance of the adhesive film 1 can be maintained, and when the adhesive film 1 is used to connect circuit members to each other, the connection resistance between the opposing electrodes can be reduced. From the viewpoint of further suppressing the generation of active species (such as radicals) from the photopolymerization initiator, the transmittance of the viewing portion 28 to light having a wavelength of 365 nm is preferably 10% or less, more preferably 5% or less, and further preferably It is 1% or less, and particularly preferably 0.1% or less.

From the same viewpoint, the maximum value of the light transmittance of the viewing portion 28 in the wavelength region capable of generating radicals, cations, or anions from the photopolymerization initiator (component (B)) is preferably 10%. Below, more preferably 5% or less, further preferably 1% or less, and particularly preferably 0.1% or less. Specifically, the maximum value of the transmittance of the visible portion 28 for light having a wavelength of 254 nm to 405 nm is preferably 10% or less, more preferably 5% or less, still more preferably 1% or less, and particularly preferably 0.1% or less.

The visual recognition portion 28 (the storage member 22) is formed of, for example, a sheet having a thickness of 10 μm to 5000 μm. The sheet includes a material having a transmittance of the viewing portion 28 of light having a wavelength of 365 nm of 10% or less. Such materials may contain one component or multiple components. Examples of the material include low-density polyethylene, linear low-density polyethylene, polycarbonate, polyester, acrylic resin, polyamide, and glass. These materials may also contain ultraviolet absorbers. The visual recognition part 28 may have a laminated structure formed by laminating a plurality of layers having different light transmission properties. In this case, each of the layers constituting the visual recognition portion 28 may include the materials described above.

In order to prevent the invasion of air from the outside during storage, the insertion port 27 may be closed by, for example, sealing with a sealing machine or the like. In this case, it is preferable to remove the air in the accommodating member 22 in advance before closing the insertion port 27. It is expected that moisture in the storage member 22 will be reduced from the initial stage of storage, and air can be prevented from entering from the outside. In addition, the inner surface of the accommodating member 22 is in close contact with the reel 21 to prevent foreign matter from being generated by friction between the inner surface of the accommodating member 22 and the surface of the reel 21 due to vibration during transportation, and to prevent the side plate 24 and side plates of the reel 21 25 scratches on the outer side.

In the said embodiment, a storage member is comprised so that the whole storage member may become a visual recognition part. In another embodiment, a storage member may have a visual recognition part in a part of a storage member. For example, the accommodating member may have a rectangular viewing portion at substantially the center of the side surface of the accommodating member. In this case, the portion other than the visual recognition portion of the storage member may be black, for example, so as not to transmit ultraviolet light and visible light.

In addition, in the embodiment, the shape of the storage member is a bag shape, and the storage member may be, for example, a box shape. The receiving member is preferably provided with a cutout for opening. In this case, the opening operation at the time of use becomes easy. [Example]

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

<Synthesis of Polyurethane Acrylate (UA1)> In a reaction vessel equipped with a stirrer, a thermometer, a reflux cooling tube having a calcium chloride drying tube, and a nitrogen introduction tube, the polymerization was uniformly added dropwise over 3 hours ( 1,6-hexanediol carbonate) (Trade name: Duranol T5652, manufactured by Asahi Kasei Chemicals Co., Ltd., the number average molecular weight is 1000) 2,500 parts by mass (2.50 mol), and Fluorone diisocyanate (manufactured by Sigma-Aldrich) 666 parts by mass (3.00 mol). Then, after sufficiently introducing nitrogen gas into the reaction vessel, the reaction vessel was heated to 70 ° C to 75 ° C to perform the reaction. Next, 0.53 parts by mass (4.3 mmol) of hydroquinone monomethyl ether (manufactured by Sigma-Aldrich) and 5.53 parts by mass of dibutyltin dilaurate (manufactured by Sigma-Aldrich) were added to the reaction vessel (8.8 mmol), 238 parts by mass (2.05 mol) of 2-hydroxyethyl acrylate (manufactured by Sigma-Aldrich) was added, and the mixture was reacted at 70 ° C. for 6 hours in an air environment. In this way, a polyurethane acrylate (UA1) was obtained. The weight average molecular weight of the polyurethane acrylate (UA1) was 15,000. The weight-average molecular weight was measured by a gel permeation chromatography (GPC) calibration curve using standard polystyrene in accordance with the following conditions. (Measurement conditions) Device: GPC-8020 manufactured by Tosoh Co., Ltd. Detector: RI-8020 manufactured by Tosoh Co., Ltd. Column: Gelpack GLA160S + GLA150S manufactured by Hitachi Chemical Co., Ltd. Sample concentration: 120 mg / 3 mL solvent: tetrahydrofuran injection volume: 60 μL pressure: 2.94 × 10 ⁶ Pa (30 kgf / cm ² ) flow rate: 1.00 mL / min

<Production of Conductive Particles> A layer containing nickel was formed on the surface of the polystyrene particles so that the layer thickness was 0.2 μm. In this manner, conductive particles having an average particle diameter of 4 μm, a maximum particle diameter of 4.5 μm, and a specific gravity of 2.5 were obtained.

<Preparation of varnish (varnish composition) of photocurable composition> The components shown below were mixed with the compounding quantity (mass part) shown in Table 1, and the photocurable composition 1-the photocurable composition 18 were prepared. Varnish. The content (vol%) of the conductive particles and the content (vol%) of the filler described in Table 1 are based on the total volume of the photocurable composition. (Polymerizable compound) A1: Dicyclopentadiene-type diacrylate (trade name: DCP-A, manufactured by Toa Synthesis Co., Ltd.) A2: Polyurethane acrylate (UA1) synthesized as described above A3: 2-methacryloxyethyl acid phosphate (trade name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) (photopolymerization initiator) B1: 1, 2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (O-benzylideneoxime)] (trade name: Irgacure (registered trademark) OXE01, BASF ( (BASF) Co., Ltd.) B2: Ethyl ketone, 1- [9-ethyl-6- (2-methylbenzylidene) -9H-carbazol-3-yl]-, 1- (o-acetamidooxime ) (Brand name: Irgacure (registered trademark) OXE02, manufactured by BASF) B3: 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -Butanone-1 (trade name: Irgacure (registered trademark) 369, manufactured by BASF) B4: 2-methyl-1- [4- (methylthio) phenyl] -2 -Morpholinylpropane-1-one (trade name: Irgacure (registered trademark) 907, BASF (Manufactured by BASF) B5: bis (2,4,6-trimethylbenzylidene) -phenylphosphine oxide (trade name: Irgacure (registered trademark) 279, BASF) (Manufactured) B6: 1-hydroxy-cyclohexyl-phenyl-one (trade name: Irgacure (registered trademark) 184, manufactured by BASF) B7: 2-hydroxy-2-methyl-1 -Phenyl-propane-1-one (trade name: Irgacure (registered trademark) 1173, manufactured by BASF) B8: 1- [4- (2-hydroxyethoxy) -phenyl ] -2-Hydroxy-2-methyl-1-propane-1-one (trade name: Irgacure (registered trademark) 2959, manufactured by BASF) B9: 2-hydroxy-1- { 4- [4- (2-hydroxy-2-methyl-propanyl) -benzyl] -phenyl} -2-methyl-propane (trade name: Irgacure (registered trademark) 127, (Manufactured by BASF) (conductive particles) C1: conductive particles (thermoplastic resin) produced as described above F1: bisphenol A type phenoxy resin (trade name: PKHC, manufactured by Union Carbide) ) (Coupling agent) G1 : 3-Methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) (filler) H1: fine particles of silicon dioxide (trade name: R104, AEROSIL Japan ) Manufactured by Co., Ltd., average particle size (primary particle size): 12 nm) (solvent) I1: methyl ethyl ketone

[Table 1]

<Preparation of varnish (varnish composition) of thermosetting composition> As the polymerizable compound a1 to polymerizable compound a3, the thermoplastic resin f1, the coupling agent g1, the filler h1, and the solvent i1, the photocurable composition is used. Polymerizable compound A1 to polymerizable compound A3, thermoplastic resin F1, coupling agent G1, filler H1, and solvent I1 are the same, and these components and the thermal polymerization initiator described below are formulated in the amounts shown in Table 2. (Parts by mass) were mixed to prepare a varnish of the thermosetting composition 1. The content (vol%) of the fillers described in Table 2 is a content based on the total volume of the thermosetting composition. (Thermal polymerization initiator) b1: benzamidine peroxide (trade name: NYPER) BMT-K40, manufactured by Nippon Oil Co., Ltd.

[Table 2]

(Example 1) [Production of first adhesive film] The varnish of the photocurable composition 1 was applied to a PET film having a thickness of 50 μm using a coating device. Then, hot air drying at 70 ° C. for 3 minutes was performed to form a layer containing the photocurable composition 1 with a thickness (thickness after drying) of 2 μm on the PET film. Next, the layer containing the photocurable composition 1 was subjected to light irradiation using a metal halide lamp so that the cumulative light amount was 3000 mJ / cm ² to polymerize the polymerizable compound. Thereby, the photocurable composition 1 is hardened, and a 1st adhesive layer is formed. By the above operations, a first adhesive film having a first adhesive layer having a thickness of 2 μm on a PET film was obtained. The density of the conductive particles at this time was about 7000 pcs / mm ² . The thickness of the first adhesive layer was measured using a laser microscope OLS4100 manufactured by Olympus Co., Ltd.

[Production of second adhesive film] The varnish of the thermosetting composition 1 was applied to a PET film having a thickness of 50 μm using a coating device. Then, it was dried by hot air at 70 ° C. for 3 minutes to form a second adhesive layer (a layer containing the thermosetting composition 1) having a thickness of 10 μm on the PET film. By the above operations, a second adhesive film including a second adhesive layer on a PET film was obtained.

[Production of Adhesive Film for Circuit Connection] The first adhesive film and the second adhesive film were heated at 40 ° C. together with a PET film as a base material, and laminated with a roll laminator. Thereby, a two-layer adhesive film for circuit connection is formed by laminating the first adhesive layer and the second adhesive layer.

[Fabrication of circuit connection structure] The adhesive film for circuit connection prepared through the spacer was provided with a COF (manufactured by FLEXSEED) with a pitch of 25 μm and a glass substrate including amorphous indium tin oxide ( ITO) thin-film electrode (height: 1200 Å) glass substrate with thin-film electrode (manufactured by Geomatics), using a thermocompression device (heating method: contact heat type, Taiyo Seiki Co., Ltd.) (Manufactured by the company), heated and pressed under conditions of 170 ° C and 6 MPa for 4 seconds, and connected across a width of 1 mm to produce a circuit connection structure (connection structure). In addition, at the time of connection, the adhesive film for circuit connection was arrange | positioned on the glass substrate so that the surface on the side of the 1st adhesive layer in a circuit connection adhesive film might face a glass substrate.

[Evaluation of Circuit Connection Structure] With respect to the obtained circuit connection structure, the connection resistance value between the opposing electrodes immediately after connection and after the high temperature and high humidity test was measured with a multimeter. The high-temperature and high-humidity test was performed by placing the circuit connection structure in a constant temperature and humidity tank at 85 ° C. and 85% RH for 200 hours. The connection resistance value was calculated as the average value of the resistance between the opposing electrodes at 16 points. The results are shown in Table 3.

(Examples 2 to 10 and Comparative Examples 1 to 8) As the photocurable composition, the photocurable composition 2 to the photocurable composition 18 were used, except that the photocurable composition was the same as that of Example 1. An adhesive film for a circuit connection and a circuit connection structure were produced in the same manner, and the circuit connection structure was evaluated in the same manner as in Example 1. The results are shown in Tables 3 to 5.

[table 3]

[Table 4]

[table 5]

It was confirmed that, compared with Comparative Examples 1 to 8, in Examples 1 to 10 using a photopolymerization initiator having a structure represented by Formula (I), Formula (II), or Formula (III), The connection resistance value can be reduced, and the connection reliability of the circuit connection structure is excellent.

1‧‧‧ Adhesive film for circuit connection

2‧‧‧ the first adhesive layer

2a‧‧‧ The surface of the first adhesive layer opposite to the second adhesive layer side

3‧‧‧The second adhesive layer

3a‧‧‧ surface of the second adhesive layer opposite to the first adhesive layer side

4‧‧‧ conductive particles

5‧‧‧ Adhesive ingredients

10‧‧‧Circuit connection structure

11‧‧‧1st circuit board

11a‧‧‧ Main surface of the first circuit board

12‧‧‧Circuit electrode (first electrode)

13‧‧‧The first circuit component

14‧‧‧ 2nd circuit board

14a‧‧‧ Main surface of the second circuit board

15‧‧‧ bump electrode (second electrode)

16‧‧‧The second circuit component

17‧‧‧Circuit Connection

18‧‧‧ Zone 1

19‧‧‧ Zone 2

20‧‧‧ Adhesive Film Containment Kit

21‧‧‧Scrolls

22‧‧‧ Containment element

23‧‧‧ core

24‧‧‧ 1st side plate

25‧‧‧ 2nd side plate

26‧‧‧ Shaft hole

27‧‧‧Inlet

28‧‧‧Inspection Department

d1‧‧‧thickness (distance) of the first adhesive layer

d2‧‧‧thickness of the second adhesive layer (distance)

S‧‧‧ The boundary between the first adhesive layer and the second adhesive layer

FIG. 1 is a schematic cross-sectional view showing an adhesive film for circuit connection according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a circuit connection structure according to an embodiment of the present invention. 3 (a) and 3 (b) are schematic cross-sectional views showing manufacturing steps of a circuit connection structure according to an embodiment of the present invention. FIG. 4 is a perspective view showing an adhesive film storage kit according to an embodiment of the present invention.

Claims (14)

An adhesive film for circuit connection includes a first adhesive layer and a second adhesive layer laminated on the first adhesive layer, and the first adhesive layer includes a photo-curable composition. A cured product, wherein the second adhesive layer includes a thermosetting composition, and the photocurable composition includes: a polymerizable compound; conductive particles; and a structure selected from the group consisting of the following formula (I): A photopolymerization initiator of at least one of the group consisting of a structure represented by formula (II) and a structure represented by the following formula (III), . The adhesive film for circuit connection according to item 1 of the patent application range, wherein the photopolymerization initiator has a structure selected from a structure represented by the following formula (IV) and a structure represented by the following formula (V) At least one structure in the formed group is a structure represented by the formula (II), [In formula (IV), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms] . The adhesive film for circuit connection according to claim 1 or claim 2, wherein the polymerizable compound is a radical polymerizable compound having a radical polymerizable group. The adhesive film for circuit connection according to any one of claims 1 to 3, wherein the photopolymerization initiator has a structure selected from the group consisting of an oxime ester structure, an α-aminobenzophenone structure, and At least one structure in the group consisting of a fluorenylphosphine oxide structure is a structure represented by the formula (I) to the formula (III). The adhesive film for circuit connection according to any one of claims 1 to 4, wherein the thermosetting composition contains a radical polymerizable compound having a radical polymerizable group. The adhesive film for circuit connection according to any one of claims 1 to 5, wherein the thickness of the first adhesive layer is 0.2 to 0.8 times the average particle diameter of the conductive particles. . A method for producing an adhesive film for circuit connection, comprising: a preparing step of preparing a first adhesive layer; and a laminating step of laminating a second adhesive layer containing a thermosetting composition on the first adhesive layer. The preparation step includes a step of hardening the photocurable composition by irradiating light to a layer containing the photocurable composition to obtain the first adhesive layer, and the photocurable composition contains: A polymerizable compound; conductive particles; and having a group selected from the group consisting of a structure represented by the following formula (I), a structure represented by the following formula (II), and a structure represented by the following formula (III) At least one structured photopolymerization initiator, . The method for producing an adhesive film for circuit connection according to item 7 of the scope of patent application, wherein the photopolymerization initiator has a structure selected from the group consisting of a structure represented by the following formula (IV) and a formula (V). At least one structure in the group consisting of the structures of is taken as the structure represented by the formula (II), [In formula (IV), R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms] . The method for producing an adhesive film for circuit connection according to item 7 or item 8 of the scope of the patent application, wherein the polymerizable compound is a radical polymerizable compound having a radical polymerizable group. The method for manufacturing an adhesive film for circuit connection according to any one of claims 7 to 9, wherein the photopolymerization initiator has a material selected from the group consisting of an oxime ester structure and an α-aminophenylphenyl group At least one structure in the group consisting of a ketone structure and a fluorenyl phosphine oxide structure is a structure represented by the formula (I) to the formula (III). The method for producing an adhesive film for circuit connection according to any one of claims 7 to 10, wherein the thermosetting composition contains a radical polymerizable compound having a radical polymerizable group. The method for manufacturing an adhesive film for circuit connection according to any one of claims 7 to 11, wherein the thickness of the first adhesive layer is 0.2 times the average particle diameter of the conductive particles. ~ 0.8 times. A method for manufacturing a circuit connection structure, comprising: interposing the adhesive film for circuit connection according to any one of claims 1 to 6 of a patent application scope between a first circuit member having a first electrode, and And a step of thermally crimping the first circuit member and the second circuit member between the second circuit members having the second electrode to electrically connect the first electrode and the second electrode. An adhesive film storage kit, comprising: the adhesive film for circuit connection according to any one of claims 1 to 6 of the scope of patent application; and a storage member for accommodating the adhesive film. The member has a viewing portion that allows the inside of the storage member to be viewed from the outside, and the viewing portion has a transmittance of light having a wavelength of 365 nm of 10% or less.