TW201920554A - Adhesive film for circuit connections and manufacturing method thereof, manufacturing method of circuit connection structure, and adhesive film housing set - Google Patents

Abstract

This adhesive film 1 for circuit connections is provided with a first adhesive layer 2 containing conductive particles 4, and a second adhesive layer 3 laminated on said first adhesive layer 2, wherein the ratio of the melt viscosity of the first adhesive layer 2 at the temperature at which the second adhesive layer 3 exhibits the lowest melt viscosity, to said lowest melt viscosity of the second adhesive layer 3 is greater than or equal to 10.

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. Specifically, a circuit connection portion formed of an adhesive film for circuit connection is used to connect circuit members to each other, and electrodes on the circuit members are electrically connected to each other via conductive particles in the circuit connection portion, thereby obtaining Circuit connection structure.

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, when a circuit connection structure obtained by using an existing adhesive film for circuit connection is placed in a high temperature and high humidity environment (for example, 85 ° C, 85% RH), there are circuit components and Peeling may occur between circuit connection portions. Such peeling causes a reduction in connection reliability of the circuit connection structure.

Therefore, an object of the present invention is to provide an adhesive film for circuit connection, which can obtain a circuit connection structure body in which peeling between a circuit member and a circuit connection portion is difficult to occur under a high temperature and high humidity environment, and a method for producing the same, and using the adhesive film A method for manufacturing a circuit connection structure and an adhesive film storage kit including the 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 containing conductive particles and a second adhesive layer laminated on the first adhesive layer, and the second adhesive layer exhibits the lowest melting. The ratio of the melt viscosity of the first adhesive layer to the minimum melt viscosity of the second adhesive layer at a viscosity temperature is 10 or more.

According to the adhesive film for circuit connection, it is possible to obtain a circuit connection structure in which a peeling between a circuit member and a circuit connection portion is unlikely to occur in a high-temperature and high-humidity environment (for example, 85 ° C., 85% RH). In other words, according to the adhesive film for circuit connection, the adhesion between the circuit member and the circuit connection portion in a high temperature and high humidity environment can be improved. Furthermore, according to this adhesive film for circuit connection, the connection resistance of the opposing electrodes of the circuit connection structure can be reduced, and the connection resistance can also be maintained low 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 including a second curable composition on the first adhesive layer. And a preparation step including a step of hardening the first curable composition by light irradiation or heating of the layer containing the first curable composition containing conductive particles to obtain a first adhesive layer, and a curing step The first hardenable composition is hardened such that the ratio of the melt viscosity of the first adhesive layer to the minimum melt viscosity of the second adhesive layer at a temperature at which the second adhesive layer exhibits the lowest melt viscosity is 10 or more. . According to this method, an adhesive film for circuit connection can be obtained, which can obtain a circuit connection structure in which peeling between a circuit member and a circuit connection portion is unlikely to occur in a high temperature and high humidity environment.

The first adhesive layer may include a cured product of the first curable composition, and the first curable composition may contain a radical polymerizable compound having a radical polymerizable group.

The second adhesive layer may contain a second curable composition, and the second curable 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, it is possible to obtain a circuit connection structure in which peeling between a circuit member and a circuit connection portion is unlikely to occur in a high temperature and high humidity environment.

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, it has been found that when the above-mentioned adhesive film for circuit connection is used after being stored or transported in an existing storage member, it may be easily generated in a high temperature and high humidity environment. Defects such as peeling between the circuit member and the circuit connection portion, and a reduction in the effect of reducing the connection resistance of the adhesive film occur. Based on the results of such studies, the present inventors and others conducted further studies, and as a result, it was found that when the first adhesive layer contains a cured product of the photocurable composition, the second adhesive layer includes In the case of the curable composition of the polymerizable compound in which the photopolymerization initiator reacts during the curing, the second adhesive layer is hardened during storage and transportation of the adhesive film, and the above-mentioned problem occurs. Therefore, based on the assumption that the polymerizable compound in the second adhesive agent layer is polymerized by radicals derived from the photopolymerization initiator remaining in the first adhesive agent layer, the present inventors and others have further studied, As a result, it was found that by forming the adhesive film storage kit including the specific storage member, it is possible to suppress the hardening of the second adhesive layer during storage or transportation, and to suppress the occurrence of the problem.

That is, according to the adhesive film storage kit according to an aspect of the present invention, when a compound capable of reacting with the photopolymerization initiator in the first adhesive layer is used as the polymerizable compound in the second adhesive layer, it can be suppressed. The hardening of the second adhesive layer during storage or transportation of the adhesive film can prevent peeling between the circuit member and the circuit connection part easily in a high temperature and high humidity environment, and reduce the reduction effect of the connection resistance of the adhesive film. The occurrence of adverse conditions. [Effect of the invention]

According to the present invention, it is possible to provide an adhesive film for circuit connection, which can obtain a circuit connection structure body in which peeling between a circuit member and a circuit connection portion is difficult to occur under a high temperature and high humidity environment, a method for manufacturing the same, and a circuit using the same A method for manufacturing a connection structure and an adhesive film storage kit including the adhesive film.

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. . The first adhesive layer 2 contains conductive particles 4.

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.

In this embodiment, the ratio of the melt viscosity X of the first adhesive layer 2 to the minimum melt viscosity Y of the second adhesive layer 3 (X / Y at the temperature Ty at which the second adhesive layer 3 shows the lowest melt viscosity Y) ) Is 10 or more. Therefore, according to the adhesive film 1, it is possible to obtain a circuit connection structure in which a peeling between a circuit member and a circuit connection portion is unlikely to occur in a high temperature and high humidity environment (for example, 85 ° C, 85% RH).

Furthermore, according to the adhesive film 1, the connection resistance of the opposing electrodes of the circuit connection structure can be reduced, and the connection resistance can be maintained low even in a high-temperature and high-humidity environment (for example, 85 ° C, 85% RH). That is, the adhesive film 1 can improve the connection reliability of the circuit connection structure. The reason why such an effect can be obtained is not clear, and the present inventors speculate that the following two aspects play an advantageous role. The first aspect is advantageous in that, in this embodiment, the ratio of the melt viscosity (X / Y) of the adhesive film 1 is 10 or more. Therefore, the conductive particles 4 are separated by the first adhesive layer 2. It is fixed to suppress the flow of the conductive particles 4 during connection, and as a result, the capture efficiency of the conductive particles 4 in the electrode is improved. The second aspect is an advantageous effect that, in this embodiment, the ratio of the melt viscosity (X / Y) of the adhesive film 1 is 10 or more. Therefore, when it is formally crimped, it is in contact with the second adhesive layer. 3, the flow of the first adhesive layer 2 is suppressed to a greater extent. For example, in a short-term pressure bonding at 170 ° C. for 5 seconds, in the case of a general adhesive (such as a two-layer adhesive), the two layers of the two laminated layers are simultaneously flowed and hardened. At this time, at the interface between the adhesive layer and the circuit member, the adhesive constituting the adhesive layer is hardened while the adhesive flows while flowing, so that strain or internal stress easily occurs. On the other hand, in this embodiment, the flow and hardening of the second adhesive layer 3 occur, but the flow and hardening of the first adhesive layer 2 hardly occur. Therefore, it is difficult to generate strain or internal stress between the circuit member and the first adhesive layer 2, and it is estimated that the adhesion between the circuit member and the circuit connection portion in a high-temperature and high-humidity environment can be improved. As a result, connection reliability can be improved.

In addition, the adhesive film 1 may be cut into a narrow width in a state of an adhesive film with a base material formed on one surface of the base material, and then wound around a winding core, whereby the Form storage and use. This adhesive reel is required to have good blocking resistance, that is, when an adhesive film with a substrate is output from the adhesive reel, the adhesive film 1 is not easily peeled from the substrate. However, in the case of the conventional adhesive film, when it is cut into a narrow width of about 0.4 mm to 1.0 mm, it may be difficult to obtain good blocking resistance. On the other hand, in the adhesive film 1 of this embodiment, the ratio (X / Y) of the melt viscosity is 10 or more, so that the adhesion (adhesion) between the first adhesive layer 2 and the substrate can be suppressed. Therefore, since the base material is provided on the surface of the second adhesive layer 3 on the opposite side to the first adhesive layer 2, even when cut to the narrow width as described above, good blocking resistance can be obtained. Propensity. The blocking resistance can be evaluated by, for example, a test of confirming whether or not the adhesive roll can be pulled out without any problem after leaving the adhesive reel in an environment of 30 ° C. for 24 hours.

From the viewpoint of improving the adhesion with the circuit member, the melt viscosity ratio (X / Y) is preferably 10 or more, more preferably 20 or more, still more preferably 50 or more, and particularly preferably 100 or more. From the viewpoint of wettability of the circuit member, the melt viscosity ratio (X / Y) may be 10,000 or less, may be 5,000 or less, and may be 1,000 or less. From these viewpoints, the ratio of melt viscosity (X / Y) may be 10 to 10,000, 20 to 5000, 50 to 5000, or 100 to 1,000. The melt viscosity X and the minimum melt viscosity Y can be obtained by measuring the melt viscosity of the first adhesive layer 2 and the second adhesive layer 3 by the method described in the examples. Specifically, first, the minimum melt viscosity Y of the second adhesive layer 3 (and the temperature Ty showing the minimum melt viscosity Y of the second adhesive layer) is determined by measuring the melt viscosity of the second adhesive layer 3, The melt viscosity X of the first adhesive layer 2 at the temperature Ty is determined by measuring the melt viscosity of the first adhesive layer 2. The measurement of the melt viscosity may be performed after the adhesive film 1 is obtained.

(First Adhesive Layer) The first adhesive layer 2 contains, for example, a cured product of a first curable composition. The first curable composition may be a photocurable composition, a thermosetting composition, or a mixture of a photocurable composition and a thermosetting composition. The first curable composition contains (A) a polymerizable compound (hereinafter also referred to as "(A) component"), (B) a polymerization initiator (hereinafter also referred to as "(B) component"), and (C ) Conductive particles 4 (hereinafter also referred to as "(C) component"). When the first curable composition is a photocurable composition, the first curable composition contains a photopolymerization initiator as the component (B), and when the first curable composition is a thermosetting composition Hereinafter, the first curable composition contains a thermal polymerization initiator as a component (B). Such a first adhesive layer 2 can be obtained, for example, by curing the first curable composition by polymerizing the component (A) by irradiating or heating the layer containing the first curable composition. That is, the first adhesive layer 2 may include conductive particles 4 and an adhesive component 5 obtained by hardening components other than the conductive particles 4 of the first curable composition. The first adhesive layer 2 may be a cured product obtained by completely curing the first curable composition, or may be a cured product obtained by partially curing the first curable composition. That is, when the (A) component and (B) component are contained in a 1st curable composition, the adhesive agent component 5 may contain unreacted (A) component and (B) component, and may not contain it. The first adhesive layer 2 may include a resin composition other than the cured product of the curable composition. For example, the first adhesive layer may include a resin composition containing resin components such as a phenoxy resin such as PKHC, a polyester urethane resin, a polyurethane resin, and an acrylic rubber. By using such a resin component, the melt viscosity at a temperature at which the second adhesive layer exhibits the lowest melt viscosity (for example, 100 ° C.) can be adjusted to about 100,000 Pa · s to 10000000 Pa · s, and the melt viscosity ratio ( X / Y) is set to 10 or more.

[(A) Component: Polymerizable Compound] The (A) component is, for example, a radical generated by a polymerization initiator (photopolymerization initiator or thermal polymerization initiator) by irradiation with light (for example, ultraviolet light) or heating. , Cationic or anionic polymerized compounds. (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 viewpoint of easily obtaining a desired melt viscosity, the viewpoint that peeling between a circuit member and a circuit connection portion is unlikely to occur in a high-temperature and high-humidity environment, and a viewpoint 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. Regarding the number of polymerizable groups contained in the component (A), from the viewpoint of easily obtaining a desired melt viscosity after polymerization, the viewpoint that peeling between a circuit member and a circuit connection portion is unlikely to occur in a high-temperature and high-humidity environment, and connection resistance. From the viewpoint of further improving the effect of reducing the temperature and more excellent connection reliability, it may be two or more, and from the viewpoint of suppressing curing shrinkage during polymerization, it may be 10 or less. In addition, 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, a polymerizable compound outside the above range may be additionally used.

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.

From the viewpoint of easily obtaining a desired melt viscosity, the viewpoint that peeling between a circuit member and a circuit connection portion is unlikely to occur in a high-temperature and high-humidity environment, and a viewpoint that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent, The (A) component is preferably a (meth) acrylate compound. The (A) component may be a (poly) urethane (meth) acrylate compound (urethane (meth) acrylate compound or poly (urethane) (Urethane (meth) acrylate compounds). Moreover, (A) component can be a (meth) acrylic acid ester compound which has a high Tg skeleton, such as a dicyclopentadiene skeleton, from a viewpoint of obtaining the said adhesive characteristic more excellent.

From the viewpoint of easily obtaining a desired melt viscosity, the viewpoint that peeling between a circuit member and a circuit connection portion is unlikely to occur in a high-temperature and high-humidity environment, and a viewpoint that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent, The component (A) may be a polymerizable group such as a vinyl group, an allyl group, or a (meth) acrylfluorenyl group introduced into a terminal or side chain of a thermoplastic resin such as an acrylic resin, a phenoxy resin, or a polyurethane resin. Compounds (such as polyurethane (meth) acrylates). 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 1] [Wherein 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 a desired melt viscosity, the viewpoint that peeling between a circuit member and a circuit connection portion is unlikely to occur in a high-temperature and high-humidity environment, and a viewpoint that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent, The content of the component (A) may be 5 mass% or more, may be 10 mass% or more, and may be 20 mass% or more on the basis of the total mass of the first curable composition. 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% based on the total mass of the first curable composition. Mass% or less.

[(B) component: polymerization initiator] (B) component may be light containing a wavelength in a range of 150 to 750 nm, preferably light containing a wavelength in a range of 254 to 405 nm, A photopolymerization initiator (photoradical polymerization initiator, photocationic polymerization initiator, or photoanionic polymerization) that generates radicals, cations, or anions by irradiation with light having a wavelength of 365 nm (for example, ultraviolet light) is further preferred. Initiator), or a thermal polymerization initiator (thermal radical polymerization initiator, thermal cationic polymerization initiator, or thermal anionic polymerization initiator) that generates free radicals, cations, or anions by heat. From the viewpoint that it is easy to obtain a desired melt viscosity, that the effect of reducing the connection resistance is further improved, and that the connection reliability is more excellent, and from the viewpoint that the hardening at a low temperature and a short time is easier, the component (B) is preferably a radical Polymerization initiator (photo radical polymerization initiator or thermal radical polymerization initiator). As component (B), one compound may be used alone, or a plurality of compounds may be used in combination. For example, the first curable composition may contain both a photopolymerization initiator and a thermal polymerization initiator as the (B) component.

The photo radical polymerization initiator is decomposed by light to generate free radicals. That is, a photoradical polymerization initiator is a compound which generates a radical by giving light energy from the outside. Examples of the photo-radical polymerization initiator include an oxime ester structure, a biimidazole structure, an acridine structure, an α-aminobenzoyl ketone structure, an amine benzophenone structure, and an N-phenylglycine acid structure. Compounds having a fluorenylphosphine oxide structure, a benzophenone dimethyl ketal structure, and an α-hydroxybenzoalkyl ketone structure. From the viewpoint that the desired melt viscosity is easily obtained and the effect of reducing the connection resistance is more excellent, it is preferred that the photoradical polymerization initiator has a structure selected from the group consisting of an oxime ester structure and an α-aminobenzoyl ketone structure. And at least one structure in the group consisting of a fluorenyl phosphine oxide structure.

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.

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-morpholinylphenyl-butanone-1 and the like.

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.

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 organic peroxide include neodecanoic acid-1,1,3,3-tetramethylbutyl peroxy, bis (4-tert-butylcyclohexyl) peroxydicarbonate, 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 First Trihexyl ester, tert-butyl peroxymaleate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, 2,5-dimethyl- 2,5-bis (3-methylbenzylideneperoxy) hexane, 2-ethylhexyl third ethyl butyl monocarbonate, third hexyl peroxybenzoate, 2,5-dimethyl -2,5-Di (benzylidene peroxy) hexane, tert-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, tert-amyl peroxyn-octanoate, peroxy Tert-amyl isononanoate, tert-amyl peroxybenzoate and the like.

Specific examples of the azo compound include 2,2'-azobis-2,4-dimethylvaleronitrile, and 1,1'-azobis (1-acetamido-1-phenyl) Ethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 4,4'-azobis (4-cyanovaleric acid), 1,1'-azobis (1-cyclohexanecarbonitrile) and the like.

From the viewpoint of excellent rapid hardening properties and the viewpoint of excellent connection resistance reduction effects, the content of the component (B) may be 0.1% by mass or more based on the total mass of the first curable composition, and may also be 0.5. Above mass%. From the viewpoint of improving the storage stability and the effect of reducing the connection resistance, the content of the (B) component may be 15% by mass or less based on the total mass of the first curable composition, and may also be 10 Mass% or less may be 5 mass% or less.

From the viewpoint of easily obtaining a desired viscosity, the first curable composition preferably contains at least one of a photopolymerization initiator and a thermal polymerization initiator as the (B) component, and an adhesive for circuit connection. From the viewpoint that the production of the film is easy, the first curable composition more preferably contains a photopolymerization initiator.

[(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 first hardenable composition by heating or pressing. Therefore, when the electrodes are electrically connected to each other, the contact area between the electrode and the (C) component can be increased to make the electrodes between the electrodes. 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 obtaining stable connection resistance, the particle density of the component (C) in the first adhesive layer 2 may be 100 pcs / mm ² or more, or 1,000 pcs / mm ² or more, and may be 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 (C) component in the first curable composition (based on the total volume of the first curable composition) may be the same as the above range.

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

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 first curable composition contains a thermoplastic resin, the first adhesive layer can be easily formed. In addition, when the first curable composition contains a thermoplastic resin, the stress of the first adhesive layer generated when the first curable composition is cured can be alleviated. 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 first curable 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 first curable composition contains a coupling agent, the adhesiveness 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 first curable composition.

Examples of the filler include non-conductive fillers (for example, non-conductive particles). When the first curable 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, 0.1% by volume or more and 50% by volume or less based on the total volume of the first curable composition.

The first curable 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 first curable composition. These additives may be contained in the first adhesive layer 2.

The first curable composition may contain a thermosetting resin instead of the components (A) and (B), or may contain a thermosetting resin in addition to the components (A) and (B). The thermosetting resin is a resin that is cured by heat, and has at least one thermosetting group. The thermosetting resin is, for example, a compound that reacts with a curing agent by heat and crosslinks it accordingly. As the thermosetting resin, one compound may be used alone, or a plurality of compounds may be used in combination.

The thermosetting group may be, for example, an epoxy group, an oxetanyl group, or an isocyanate group from the viewpoint that a desired melt viscosity is easily obtained, and the effect of reducing the connection resistance is further improved and the connection reliability is more excellent. Wait.

Specific examples of the thermosetting resin include bisphenol-type epoxy resins that are reaction products of epichlorohydrin and bisphenol A, bisphenol F, bisphenol AD, and the like; and epichlorohydrin, phenol novolac, and 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.

When a thermosetting resin is used in place of the components (A) and (B), for example, based on the total mass of the first curable composition, the content of the thermosetting resin in the first curable composition may be It is 20% by mass or more, and may be 80% by mass or less. When using a thermosetting resin other than (A) component and (B) component, for example, content of the thermosetting resin in a 1st curable composition is based on the total mass of a 1st curable composition. It may be 30% by mass or more, and may be 70% by mass or less.

When the first curable composition contains a thermosetting resin, the first curable composition may also contain a curing agent for the thermosetting resin described above. Examples of the curing agent of the thermosetting resin include a thermal radical generator, a thermal cation generator, and a thermal anion generator. The content of the hardener may be, for example, 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the thermosetting resin.

The first adhesive layer 2 may contain components derived from the first curable 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 second curable composition in the second adhesive layer 3 is hardened, and the peeling between the circuit member and the circuit connection portion easily occurs in a high-temperature and high-humidity environment, and the connection resistance of the adhesive film 1 is reduced Reduction of other adverse conditions. Therefore, from the viewpoint of suppressing the occurrence of the above-mentioned problems, based on the total mass of the first adhesive layer, the content of the component (B) in the first adhesive layer 2 may be 15% by mass or less. It may be 10 mass% or less, and may be 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. When the first adhesive layer 2 includes a photopolymerization initiator as the component (B), the adhesive film 1 can be stored in a storage member described later to prevent the occurrence of the above-mentioned problems.

From the standpoint that peeling is less likely to occur, the melt viscosity X of the first adhesive layer 2 at a temperature Ty at which the second adhesive layer 3 exhibits the lowest melt viscosity Y may be 1,000 Pa · s or more, and may also be 10,000 Pa · s or more may be 50,000 Pa · s or more. From the viewpoint of excellent wettability to the substrate, the melt viscosity X may be 10,000,000 Pa · s or less, or 1,000,000 Pa · s or less, or 500,000 Pa · s or less. The melt viscosity X can be adjusted by changing the composition of the first curable composition, changing the curing conditions of the first curable composition, and the like.

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 or 0.3 times or more from the viewpoint that the conductive particles 4 are easily captured between the 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 second curable composition. The second curable composition contains, for example, (a) a polymerizable compound (hereinafter also referred to as (a) component) and (b) a polymerization initiator (hereinafter also referred to as (b) component). The second curable composition may be a thermosetting composition containing a thermal polymerization initiator as component (b), or a photocurable composition containing a photopolymerization initiator as component (b), or may be A mixture of a thermosetting composition and a photocurable composition. The second curable composition constituting the second adhesive layer 3 is an uncured curable composition that can flow during circuit connection, and is, for example, an uncured curable composition.

[(A) component: polymerizable compound] (a) component is, for example, a radical generated by a polymerization initiator (photopolymerization initiator or thermal polymerization initiator) by irradiation with light (for example, ultraviolet light) or heating. , Cationic or anionic polymerized compounds. As (a) component, the compound exemplified as (A) component can be used. From the viewpoints of easy connection at low temperature and short time, easy to obtain desired melt viscosity, and further improvement of connection resistance reduction effect and more excellent connection reliability, the component (a) preferably has a free radical A radically polymerizable compound that reacts with a radically polymerizable group. 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 second curable 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 a crosslink density required to reduce connection resistance and improve connection reliability, the content of (a) component may be 10% by mass or more based on the total mass of the second curable composition. It may be 20% by mass or more, and may also be 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 second curable composition, and may also be 80% by mass. % Or less, or 70% by mass or less.

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

From the viewpoint of easier connection at a low temperature for a short time, and a viewpoint of more excellent connection reliability, the content of the component (b) may be 0.1% by mass or more based on the total mass of the second curable composition. It may be 0.5 mass% or more, and may be 1 mass% or more. From the standpoint of pot life, the content of the component (b) may be 30% by mass or less, or 20% by mass or less, based on the total mass of the second curable composition. Mass% or less.

[Other Components] The second curable 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 second curable composition may contain a thermosetting resin instead of the components (a) and (b), or may contain a thermosetting resin in addition to the components (a) and (b). When the second curable composition contains a thermosetting resin, the second curable composition may contain a curing agent for curing the thermosetting resin. As the thermosetting resin and curing agent, the same thermosetting resin and curing agent as the thermosetting resin and curing agent exemplified as the other components in the first curable composition can be used. When a thermosetting resin is used instead of the components (a) and (b), for example, based on the total mass of the second curable composition, the content of the thermosetting resin in the second curable composition may be It is 20% by mass or more, and may be 80% by mass or less. When using a thermosetting resin other than (a) component and (b) component, for example, content of the thermosetting resin in a 2nd curable composition is based on the total mass of a 2nd curable composition. It 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 first curable 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.

From the viewpoint of obtaining excellent blocking resistance, the minimum melt viscosity Y of the second adhesive layer 3 may be 50 Pa · s or higher, 100 Pa · s or higher, or 300 Pa · s or higher. . From the viewpoint of obtaining excellent inter-electrode filling properties (resin filling properties), the minimum melt viscosity Y may be 100,000 Pa · s or less, may be 10,000 Pa · s or less, and may be 5,000 Pa · s or less. The minimum melt viscosity Y can be adjusted by changing the composition of the second curable composition and the like.

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 that the space between the electrodes can be sufficiently filled to seal the electrodes and obtain better 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 1,000 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.

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. A layer having the same physical properties (for example, melt viscosity) as described above may be a layer having the same thickness as described above with respect to the first adhesive layer or the second adhesive 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 second curable composition (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, (A) component, (B) component, (C) component, and other components added as needed are added to an organic solvent, and a varnish composition is prepared by dissolving or dispersing by stirring, mixing, kneading, etc. Thing. 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 the first curable composition on the substrate. Then, the first curable composition is cured by irradiating or heating the layer containing the first curable composition 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.

As the substrate, when the first curable composition is hardened by light, there is no particular limitation as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized. When the first curable composition is cured, there is no particular limitation as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized and the heating conditions when the first curable composition is cured. As the substrate, for example, oriented polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, and polyethylene can be used. Butyl terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene-vinyl acetate copolymer, polyvinyl chloride, poly Substrates (such as films) such as vinylidene chloride, synthetic rubbers, and liquid crystal polymers.

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, or the like. The amount of light irradiation can be adjusted so that the melt viscosity ratio (X / Y) becomes 10 or more. The irradiation amount of light may be, for example, 100 mJ / cm ² or more, or 200 mJ / cm ² or more, or 300 mJ / cm ² or more, as a cumulative light amount of light having a wavelength of 365 nm. The irradiation amount of light may be, for example, 10,000 mJ / cm ² or less, or 5,000 mJ / cm ² or less, or 3,000 mJ / cm ² or less, as a cumulative light amount of light having a wavelength of 365 nm. The larger the amount of light irradiation (the cumulative amount of light), the greater the melt viscosity X, and the greater the melt viscosity ratio (X / Y).

The heating conditions in the hardening step can be adjusted so that the melt viscosity ratio (X / Y) becomes 10 or more. The heating conditions may be, for example, 30 ° C. to 300 ° C., 0.1 minutes to 5,000 minutes, or 50 ° C. to 150 ° C., 0.1 minutes to 3,000 minutes. The higher the heating temperature, the higher the melt viscosity X, and the higher the melt viscosity ratio (X / Y). In addition, as the heating time is longer, the melt viscosity X tends to be larger, and the melt viscosity ratio (X / Y) tends to be larger.

The second preparation step is the same as the first preparation step, except that the components (a) and (b) and other components added as necessary are not used, and the curing step is not performed (light irradiation and heating are not performed). A second adhesive agent layer 3 is formed on a substrate to obtain a second adhesive agent film, thereby preparing a second adhesive agent 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, under heating conditions 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 portion 17 is formed of the adhesive film 1 described above. The circuit connection part 17 contains the hardened | cured material of the adhesive film 1, for example. 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 first section described above. 1 hardened composition of conductive particles other than components (A), (B), and other components; the second region 19 is located on the second circuit member 16 side in the opposite direction, and contains the component (a), (B) the hardened body of the second hardenable composition as described above; and the conductive particles 4 interposed between the first electrode 12 and the second electrode 15 at least between the first electrode 12 and the second electrode 15 Are electrically connected to each other. 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 cured product of components other than the conductive particles 4 of the first curable composition described above and the first described above. 2 The hardened | cured material of hardened composition is a hardened | cured material mixed.

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. In addition, for example, the adhesive film 1 may be laminated on the second circuit member 16 so that the first adhesive layer 2 side faces the mounting surface 14 a of the second circuit member 16. In this case, the first electrode 12 on the first circuit substrate 11 and the second electrode 15 on the second circuit substrate 14 face each other so that the first electrode 12 is laminated on the second circuit member 16 on which the adhesive film 1 is laminated. 1 电路 机构 13。 1 circuit member 13.

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, the adhesive film 1 is heated to a temperature Ty at which the second adhesive layer 3 exhibits the lowest melt viscosity Y. In this embodiment, the melt viscosity ratio (X / Y) of the adhesive film 1 is 10 or more. Therefore, the second adhesive layer 3 can flow during the thermocompression bonding. On the other hand, the first adhesive layer 2 Hardly flows. As a result, as shown by an arrow in FIG. 3 (b), the second adhesive layer flows so as to fill the gap between the second electrode 15 and the second electrode 15, 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 conductive particles 4 are fixed to the first adhesive layer 2 and the first adhesive layer 2 hardly flows during the thermocompression bonding, so that the opposing direction can be reduced. The connection resistance between the electrodes 12 and 15 of. Therefore, a circuit connection structure having excellent connection reliability can be obtained. When the second curable composition contains a photocurable composition, instead of thermal compression bonding by heating, pressurization and light irradiation may be performed, or pressurization and heating and light irradiation may be performed. The first circuit member 13 and the second circuit member 16 are bonded together.

<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, in the case where a photopolymerization initiator is used as the (B) component, the light and the light incident from the outside to the inside of the storage member 22 can be suppressed. 1 The second curable composition is hardened by the photopolymerization initiator remaining in the adhesive layer 2. As a result, it is possible to suppress the occurrence of undesirable conditions such as easy peeling between the circuit member and the circuit connection portion under a high temperature and high humidity environment, and a reduction in the connection resistance of the adhesive film. 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 the first varnish (varnish composition) of the first curable composition> The components shown below were mixed at the compounding amount (parts by mass) shown in Table 1 to prepare the varnish of the first curable composition 1 and the first Varnish of the curable composition 2. 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 first curable composition. (Polymerizable compound) A1: Dicyclopentadiene-type diacrylate (trade name: Light Acrylate DCP-A, manufactured by Toa Synthesis Co., Ltd.) A2: Polyaminomethyl synthesized as described above Ester Acrylate (UA1) A3: 2-Methacryloxyethyl Ethyl Phosphate (Trade Name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) (Initiation of polymerization Agent) B1: 1,2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (O-benzylideneoxime)] (trade name: Irgacure (registered Trademark) OXE01, manufactured by BASF) B2: benzamyl peroxide (trade name: NYPER) BMT-K40, manufactured by Nippon Oil Co., Ltd. (conductive particles) C1: produced as described above Conductive particles (thermoplastic resin) D1: bisphenol A type phenoxy resin (trade name: PKHC, manufactured by Union Carbide) (coupling agent) E1: 3-methacryloxypropyltrimethyl Oxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) (filler) F1: Silicon dioxide fine particles (trade name: R104, manufactured by Japan Aerosil Corporation), average particle size (primary particle size): 12 nm, specific gravity: 2) (solvent) G1: methyl ethyl ketone

[Table 1]

<Preparation of varnish (varnish composition) of the second curable composition> As the polymerizable compound a1 to polymerizable compound a3, the polymerization initiator b1, the thermoplastic resin d1, the coupling agent e1, the filler f1, and the solvent g1, use The polymerizable compounds A1 to A3, the polymerization initiator B2, the thermoplastic resin D1, the coupling agent E1, the filler F1, and the solvent G1 in the first curable composition are the same as those in Table 2 The blending amounts (parts by mass) shown were mixed to prepare a varnish of the second curable composition 1. The content (vol%) of the fillers described in Table 2 is a content based on the total volume of the second curable composition.

[Table 2]

(Example 1) [Production of first adhesive film] A varnish of the first curable 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 layer containing the first curable composition 1 with a thickness (thickness after drying) of 2 μm on the PET film. Next, the layer containing the first curable composition 1 was irradiated with light using a metal halide lamp so that the accumulated light amount was 300 mJ / cm ² to polymerize the polymerizable compound. Thereby, the 1st curable composition 1 is hardened, and the 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 second curable 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 including the second curable 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.

[Measurement of Melt Viscosity] The melt viscosity of the first adhesive layer and the minimum melt viscosity of the second adhesive layer at a temperature at which the second adhesive layer exhibited the lowest melt viscosity were measured by the following methods. Specifically, first, the first adhesive film and the second adhesive film were each heated at 40 ° C. so as to have a thickness of 200 μm, and simultaneously laminated with a roll laminator. Then, it cut | disconnected to 0.8 cmf, and obtained the test piece. Next, the obtained test piece was subjected to melt viscosity measurement using a melt viscosity measurement device (trade name: ARES-G2, manufactured by TA Instruments). The measurement conditions were a measurement temperature: 0 ° C to 200 ° C, a temperature increase rate: 10 ° C / min, a frequency: 10 Hz, and a strain: 0.5%.

The temperature (temperature Ty) at which the second adhesive layer showed the lowest melt viscosity was 103 ° C. The melt viscosity (melt viscosity X) of the first adhesive layer at the temperature Ty was 6 × 10 ⁴ Pa · s. The minimum melt viscosity (lowest melt viscosity Y) of the second adhesive layer was 1 × 10 ³ Pa · s. From these results, the melt viscosity ratio (X / Y) was 60. In the measurement, the thickness of the first adhesive film and the second adhesive film is 200 μm, but the thickness of the adhesive film is not particularly limited, and may be, for example, 100 μm to 1000 μm.

[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 base material-equipped adhesive film for circuit connection including a two-layered circuit connection adhesive film including a first adhesive layer and a second adhesive layer is produced.

[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 pressurized 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 including a circuit connection portion formed by an adhesive film for circuit connection ( 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.

[Peel Evaluation] Using an optical microscope, the connection appearance of the obtained circuit connection structure immediately after connection and the connection appearance after the high-temperature and high-humidity test were observed, and peel evaluation was performed. Specifically, the area (peeling area) where peeling occurred between this glass substrate and a circuit connection part was measured from the glass substrate side with a thin-film electrode. The high-temperature and high-humidity test was performed by leaving it in a constant temperature and humidity tank at 85 ° C. and 85% RH for 200 hours. The results are shown in Table 3.

[Evaluation of blocking resistance] The prepared adhesive film for circuit connection with a substrate was cut to 0.6 mm to obtain a tape-shaped adhesive film with a substrate. A reel for adhesive tape including a core and an annular side plate having a width of 0.7 mm, an inner diameter of 40 mm, and an outer diameter of 65 mm was prepared. The annular side plates were provided at both ends of the core. One sheet (two sheets in total), with a thickness of 2 mm, an inner diameter of 40 mm, an outer diameter of 125 mm, and containing plastic so that the side of the adhesive film side is the inner side, and the adhesive tape with the substrate is applied The film is wound on a roll for this adhesive tape. In the manner described above, an adhesive reel obtained by winding an adhesive film with a substrate having a length of 50 m and a width of 0.6 mm around a winding core was obtained.

The obtained adhesive reel was left in a thermostatic bath at 30 ° C. for 24 hours, and then it was confirmed whether the adhesive film was pulled out without any problem. A case where it was pulled out without problems was evaluated as A, and a case where problems such as adhesion (adhesion) to the base material occurred when it was pulled out was evaluated as B. The results are shown in Table 3.

(Example 2) In the production of the first adhesive film, light irradiation was performed so that the cumulative light amount was 2000 mJ / cm ^2. Except that, an adhesive film for circuit connection was produced in the same manner as in Example 1 and The circuit-connected structure was subjected to melt viscosity measurement, peeling evaluation, and blocking resistance evaluation in the same manner as in Example 1. The results are shown in Table 3.

(Example 3) The first curable composition 2 was used instead of the first curable composition 1, and when the first adhesive film was produced, the layer containing the first curable composition 2 was heated at 100 ° C. Except that heating was performed for 20 minutes instead of light irradiation to harden, an adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1, and the melt viscosity was performed in the same manner as in Example 1. Measurement, peel evaluation and blocking resistance evaluation. The results are shown in Table 3.

(Example 4) The first curable composition 2 was used in place of the first curable composition 1, and when the first adhesive film was produced, the layer containing the first curable composition 2 was heated at 100 ° C. Except that heating was performed for 180 minutes instead of light irradiation to harden, except that an adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1, and the melt viscosity was performed in the same manner as in Example 1. Measurement, peel evaluation and blocking resistance evaluation. The results are shown in Table 3.

(Example 5) The first curable composition 2 was used in place of the first curable composition 1, and when the first adhesive film was produced, the layer containing the first curable composition 2 was heated at 100 ° C. Except that heating was performed for 5 minutes instead of light irradiation to harden, except that an adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1, and melt viscosity was performed in the same manner as in Example 1. Measurement, peel evaluation and blocking resistance evaluation. The results are shown in Table 3.

(Comparative Example 1) The first curable composition 2 was used instead of the first curable composition 1, and no light was irradiated during the production of the first adhesive film (the first curable composition 2 was not made). Except for layer hardening), an adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1, and melt viscosity measurement, peeling evaluation, and blocking resistance were performed in the same manner as in Example 1. Evaluation. The results are shown in Table 4.

(Comparative Example 2) In the production of the first adhesive film, light irradiation was performed so that the accumulated light amount was 50 mJ / cm ^2. Except that, an adhesive film for circuit connection was produced in the same manner as in Example 1 and The circuit-connected structure was subjected to melt viscosity measurement, peeling evaluation, and blocking resistance evaluation in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 3) The first curable composition 2 was used in place of the first curable composition 1, and when the first adhesive film was produced, the layer containing the first curable composition 2 was heated at 60 ° C. Except that heating was performed for 30 minutes instead of light irradiation to harden, except that an adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1, and the melt viscosity was performed in the same manner as in Example 1. Measurement, peel evaluation and blocking resistance evaluation. The results are shown in Table 4.

[table 3]

[Table 4]

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 (10)

An adhesive film for circuit connection includes a first adhesive layer containing conductive particles and a second adhesive layer laminated on the first adhesive layer, and the second adhesive layer exhibits the lowest melting. The ratio of the melt viscosity of the first adhesive layer to the minimum melt viscosity of the second adhesive layer at a viscosity temperature is 10 or more. The adhesive film for circuit connection according to item 1 of the scope of patent application, wherein the first adhesive layer contains a cured product of a first curable composition, and the first curable composition contains a radical polymerizable polymer. Radical polymerizable compound. The adhesive film for circuit connection according to claim 1 or claim 2, wherein the second adhesive layer includes a second curable composition, and the second curable composition includes a radical polymerizer. Radical polymerizable compound. The adhesive film for circuit connection according to any one of claims 1 to 3, 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 manufacturing 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 containing a second curable composition on the first adhesive layer. A layer, the preparation step includes a hardening step of hardening the first curable composition by light irradiation or heating of the layer containing the first curable composition containing conductive particles to obtain the first adhesive Layer, in the hardening step, the melt viscosity of the first adhesive layer at a temperature at which the second adhesive layer exhibits the lowest melt viscosity relative to When the ratio is 10 or more, the first curable composition is cured. The method for producing an adhesive film for circuit connection according to claim 5 in the patent application scope, wherein the first curable composition contains a radical polymerizable compound having a radical polymerizable group. The method for producing an adhesive film for circuit connection according to claim 5 or claim 6, wherein the second curable 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 5 to 7, 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 4 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 4 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.