WO2020184583A1

WO2020184583A1 - Adhesive film for circuit connection, manufacturing method thereof, manufacturing method of circuit connection structure, and adhesive film accommodating set

Info

Publication number: WO2020184583A1
Application number: PCT/JP2020/010385
Authority: WO
Inventors: 友美子大當; 直工藤; 伊藤　彰浩
Original assignee: 日立化成株式会社
Priority date: 2019-03-13
Filing date: 2020-03-10
Publication date: 2020-09-17
Also published as: CN113613892A; TW202045650A; KR20210141953A; JPWO2020184583A1

Abstract

An adhesive film 1 for circuit connection comprises a first adhesive layer 2 and a second adhesive layer 3 laminated on the first adhesive layer 2, wherein the first adhesive layer 2 is composed of a photocured product of a photocurable thermosetting composition including a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, and conductive particles 4, and the second adhesive layer 3 is composed of a thermosetting composition.

Description

Adhesive film for circuit connection and its manufacturing method, manufacturing method of circuit connection structure, and adhesive film accommodating set

The present invention relates to an adhesive film for circuit connection and a method for manufacturing the same, a method for manufacturing a circuit connection structure, and an adhesive film accommodating set.

Conventionally, various adhesive materials have been used for circuit connection. For example, as an adhesive material for connecting a liquid crystal display and a tape carrier package (TCP), a flexible printed wiring board (FPC) and TCP, or a connection between FPC and a printed wiring board, conductive particles in an adhesive. An adhesive film for circuit connection having an anisotropic conductivity in which is dispersed is used.

In the field of precision electronic devices in which an adhesive film for circuit connection having anisotropic conductivity is used, the density of circuits is increasing, and the electrode width and electrode spacing are extremely narrow. Therefore, it is not always easy to efficiently capture conductive particles on microelectrodes and obtain high connection reliability.

On the other hand, for example, Patent Document 1 proposes a method in which conductive particles are unevenly distributed on one side of an anisotropic conductive adhesive sheet to separate the conductive particles from each other.

International Publication No. 2005/54388

However, in the method of Patent Document 1, since the conductive particles flow when the circuit is connected, the conductive particles may aggregate between the electrodes and a short circuit may occur. Further, the distribution of the density of the conductive particles due to the flow of the conductive particles may not only reduce the insulating characteristics but also cause variations in the connection resistance value, and there is still room for improvement.

Therefore, the present invention relates to a circuit connection adhesive film capable of suppressing the flow of conductive particles generated during the manufacture of the circuit connection structure and a method for manufacturing the same, a method for manufacturing the circuit connection structure using the adhesive film, and It is an object of the present invention to provide an adhesive film accommodating set including the adhesive film.

The circuit-connecting adhesive film on one side of the present invention comprises a first adhesive layer and a second adhesive layer laminated on the first adhesive layer, and the first adhesive. The layer is composed of a photocurable product of a light and thermosetting composition containing a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, and conductive particles, and the second adhesive layer is thermally. It consists of a curable composition.

According to the circuit connection adhesive film on the side surface, the flow of conductive particles generated during the manufacture of the circuit connection structure can be suppressed. According to such an adhesive film for circuit connection, the connection resistance between the opposing electrodes of the circuit connection structure can be reduced, and further, even in a high temperature and high humidity environment (for example, 85 ° C., 85% RH). Low connection resistance can be maintained. That is, according to this circuit connection adhesive film, the connection reliability of the circuit connection structure can be improved.

By the way, the adhesive film for circuit connection is peeled off from the circuit member even when the circuit connection structure is used for a long period of time in a high temperature and high humidity environment (for example, 85 ° C., 85% RH) after the circuit member is connected. It is required not to. According to the above-mentioned adhesive film for circuit connection, peeling at the interface between the circuit member and the circuit connection portion formed by the adhesive film, which occurs when the circuit connection structure is used in a high temperature and high humidity environment, is also suppressed. There is a tendency to be able to do it.

The method for producing an adhesive film for circuit connection on one aspect of the present invention includes a preparation step of preparing a first adhesive layer and a second adhesive composed of a thermosetting composition on the first adhesive layer. A laminating step of laminating the layers is provided, and the preparation step is to prepare a layer composed of a light and a thermosetting composition containing a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, and conductive particles. It comprises a step of curing the light and thermosetting composition by irradiating it with light to obtain a first adhesive layer. According to this method, it is possible to obtain an adhesive film for circuit connection capable of suppressing the flow of conductive particles generated during the manufacture of the circuit connection structure.

The polymerizable compound may be a radically polymerizable compound having a radically polymerizable group, and may contain a radically polymerizable compound having a phosphoric acid ester structure represented by the following formula (1).

[In formula (1), n represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group. ]

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

The photopolymerization initiator may have a structure represented by the following formula (I).

The structure represented by the above formula (I) may be an oxime ester structure, a bisimidazole structure or an acridine structure.

The photopolymerization initiator may contain a compound having a structure represented by the following formula (VI).

[In the formula (VI), R ¹¹ , R ¹² and R ¹³ each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group. ]

The thickness of the first adhesive layer may be 0.1 to 0.8 times the average particle size of the conductive particles.

In the method for manufacturing the circuit connection structure on one side of the present invention, the above-mentioned circuit connection bonding is performed between the first circuit member having the first electrode and the second circuit member having the second electrode. A step of electrically connecting the first electrode and the second electrode to each other by heat-pressing the first circuit member and the second circuit member with an agent film interposed therebetween.

The adhesive film accommodating set on one side of the present invention includes the above-mentioned adhesive film for circuit connection and an accommodating member accommodating the adhesive film, and the accommodating member can visually recognize the inside of the accommodating member from the outside. It has a visible portion, and the transmittance of light having a wavelength of 365 nm in the visible portion is 10% or less.

By the way, in general, the environment in which the adhesive film for circuit connection is used is a room called a clean room where the temperature, humidity, and cleanliness of the room are controlled at a certain level, and when shipped from the production site, it is directly exposed to the outside air. The circuit connection adhesive film is housed in a housing member such as a packing bag so as not to be exposed and cause quality deterioration due to dust and moisture. Normally, this accommodating member is made of a transparent material so that various information such as the product name, lot number, and expiration date affixed to the internal adhesive film can be confirmed from outside the accommodating member. A part is provided.

However, when the above-mentioned adhesive film for circuit connection is housed in a conventional housing member and used after being stored or transported, the above-mentioned effects of the adhesive film may not be obtained. Revealed by. As a result of further studies by the present inventors based on such study results, a compound capable of reacting with light and a photopolymerization initiator in the thermosetting composition was used as the polymerizable compound in the thermosetting composition. In some cases, it was revealed that the thermosetting composition was cured during storage and transportation of the adhesive film, and the effect of reducing the connection resistance was reduced. Therefore, the present inventors further investigated based on the speculation that the polymerization of the polymerizable compound in the thermosetting composition is proceeding by the radicals derived from the photopolymerization initiator remaining in the first adhesive layer. As a result, by forming an adhesive film accommodating set provided with the above-mentioned specific accommodating member, it is possible to suppress curing of the thermosetting composition during storage or transportation, and reduce the connection resistance of the adhesive film. We found that the effect could be maintained.

That is, according to the adhesive film containing set on one aspect of the present invention, when a compound capable of reacting with light and a photopolymerization initiator in the thermosetting composition is used as the polymerizable compound in the thermosetting composition. , Curing of the thermosetting composition during storage or transportation of the adhesive film can be suppressed, and the effect of reducing the connection resistance of the adhesive film can be maintained.

According to the present invention, it is possible to provide a circuit connection adhesive film capable of suppressing the flow of conductive particles generated during the manufacture of a circuit connection structure, and a method for manufacturing the same. Further, according to the present invention, it is possible to provide a method for manufacturing a circuit connection structure using such an adhesive film. Further, according to the present invention, it is possible to provide an adhesive film accommodating set including such an adhesive film.

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. FIG. 3 is a schematic cross-sectional view showing a manufacturing process of the circuit connection structure according to the embodiment of the present invention. FIG. 4 is a perspective view showing an adhesive film accommodating set according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings in some cases. In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. In addition, the upper limit value and the lower limit value described individually can be arbitrarily combined. Further, in the present specification, "(meth) acrylate" means at least one of acrylate and the corresponding methacrylate. The same is true for other similar expressions such as "(meth) acryloyl". In addition, "(poly)" means both with and without the prefix of "poly".

<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 circuit connection adhesive film 1 (hereinafter, also simply referred to as “adhesive film 1”) is laminated on the first adhesive layer 2 and the first adhesive layer 2. A second adhesive layer 3 is provided.

(First adhesive layer)
The first adhesive layer 2 is composed of a cured product (photo-cured product) of a light and thermosetting composition. The light and thermosetting composition includes (A) a polymerizable compound (hereinafter, also referred to as “(A) component”), (B) a photopolymerization initiator (hereinafter, also referred to as “(B) component”), and the like. It contains (C) a thermal polymerization initiator (hereinafter, also referred to as “component (C)”) and (D) conductive particles 4 (hereinafter, also referred to as “component (D)”).

In the first adhesive layer 2, for example, the component (A) is polymerized by irradiating a layer composed of light and a thermosetting composition with light energy to cure the light and the thermosetting composition (light). It is obtained by curing). That is, the first adhesive layer 2 is composed of conductive particles 4 and an adhesive component 5 obtained by photocuring light and a thermosetting composition. The adhesive component 5 contains at least a polymer of the component (A). The adhesive component 5 may or may not contain the unreacted components (A) and (B).

[Component (A): Polymerizable compound]
The component (A) is, for example, a compound polymerized by radicals, cations or anions generated by a photopolymerization initiator by irradiation with light (for example, ultraviolet light). The component (A) 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 preferably a radically polymerizable group that reacts with radicals from the viewpoint of further improving the effect of reducing the connection resistance and improving the connection reliability. That is, the component (A) is preferably a radically polymerizable compound. Examples of the radically polymerizable group include a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenylene group, a (meth) acryloyl group, a maleimide group and the like. The number of polymerizable groups contained in the component (A) may be 2 or more from the viewpoint that the physical properties required for reducing the connection resistance and the crosslink density can be easily obtained after the polymerization, and the curing shrinkage during the polymerization is suppressed. From the viewpoint, it may be 10 or less. From these viewpoints, the number of polymerizable groups contained in the component (A) may be 2 to 10. Suppressing the curing shrinkage during polymerization is preferable in that a uniform and stable film (first adhesive layer) can be obtained after light irradiation. In the present embodiment, in order to balance the crosslink density and the curing shrinkage, a polymerizable compound having a number of polymerizable groups within the above range is used, and then a polymerizable compound having a number of polymerizable groups outside the above range is used. May be used additionally.

Specific examples of the component (A) include (meth) acrylate compound, maleimide compound, vinyl ether compound, allyl compound, styrene derivative, acrylamide derivative, nadiimide derivative, natural rubber, isoprene rubber, butyl rubber, nitrile rubber, butadiene rubber, and styrene-. Examples thereof include butadiene rubber, acrylonitrile-butadiene rubber, and carboxylated nitrile rubber.

Examples of the (meth) acrylate compound include epoxy (meth) acrylate, (poly) urethane (meth) acrylate, methyl (meth) acrylate, polyether (meth) acrylate, polyester (meth) acrylate, polybutadiene (meth) acrylate, and 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 ( Meta) acrylate, 2-hydroxyethyl (meth) acrylate, isopropyl (meth) acrylate, hydroxypropyl (meth) acrylate, isobutyl (meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, tetrahydrofurfreel (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, N, N -Dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethyl propantri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, polyethylene glycol Di (meth) acrylate, polyalkylene glycol di (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, penta Elythritol (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid-modified bifunctional (meth) acrylate, isocyanuric acid-modified trifunctional (meth) acrylate, tricyclodecanyl acrylate, dimethylol-tricyclodecanediacrylate, 2 -Hydroxy-1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2,2 -Di (meth) acryloyloxydiethyl phosphate, 2- (meta) ) Acryloyloxyethyl acid phosphate and the like can be mentioned.

Maleimide compounds include 1-methyl-2,4-bismaleimidebenzene, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide, N, N'-m-toluylene bismaleimide. , N, N'-4,4-biphenylene bismaleimide, N, N'-4,4- (3,3'-dimethyl-biphenylene) bismaleimide, N, N'-4,4- (3,3' -Dimethyldiphenylmethane) bismaleimide, N, N'-4,4- (3,3'-diethyldiphenylmethane) bismaleimide, N, N'-4,4-diphenylmethane bismaleimide, N, N'-4,4- Diphenylpropane bismaleimide, N, N'-4,4-diphenyl ether bismaleimide, N, N'-3,3-diphenylsulfone bismaleimide, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane, 2,2-bis (3-s-butyl-4-8 (4-maleimidephenoxy) phenyl) propane, 1,1-bis (4- (4-maleimidephenoxy) phenyl) decane, 4,4'-cyclohexyli Examples thereof include den-bis (1- (4 maleimide phenoxy) -2-cyclohexyl) benzene and 2,2'-bis (4- (4-maleimide phenoxy) phenyl) hexafluoropropane.

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

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

The component (A) is preferably a (meth) acrylate compound from the viewpoint of excellent balance between the curing reaction rate and the physical properties after curing. The component (A) is a (poly) urethane (meth) acrylate compound from the viewpoint of achieving both cohesive force for reducing connection resistance and elongation for improving adhesive force and obtaining better adhesive properties. You can. Further, the component (A) may be a (meth) acrylate compound having a high Tg skeleton such as a dicyclopentadiene skeleton from the viewpoint of improving the cohesive force and further reducing the connection resistance.

The component (A) is the terminal or side of a thermoplastic resin such as an acrylic resin, a phenoxy resin, or a polyurethane resin from the viewpoint of balancing the crosslink density and the curing shrinkage, further reducing the connection resistance, and improving the connection reliability. It may be a compound (for example, polyurethane (meth) acrylate) in which a polymerizable group such as a vinyl group, an allyl group, or a (meth) acryloyl group is introduced into the chain. In this case, the weight average molecular weight of the component (A) may be 3000 or more, 5000 or more, or 10,000 or more from the viewpoint of excellent balance between the crosslink density and the curing shrinkage. Further, the weight average molecular weight of the component (A) may be 1 million or less, 500,000 or less, or 250,000 or less from the viewpoint of excellent compatibility with other components. From these viewpoints, the weight average molecular weight of the component (A) may be 30 to 1,000,000, 5,000 to 500,000, or 10,000 to 250,000. The weight average molecular weight refers to a value measured from a gel permeation chromatograph (GPC) using a calibration curve using standard polystyrene according to the conditions described in Examples.

The component (A) preferably contains, as the (meth) acrylate compound, a radically polymerizable compound having a phosphoric acid ester structure represented by the following formula (1). In this case, since the adhesive strength to the surface of the inorganic substance (metal or the like) is improved, it is suitable for adhesion between electrodes (for example, circuit electrodes).

In formula (1), n represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group.

The radically polymerizable compound having the above phosphoric acid 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 phosphoric acid ester structure include mono (2- (meth) acryloyloxyethyl) acid phosphate, di (2- (meth) acryloyloxyethyl) acid phosphate and the like.

The content of the component (A) is the total of the components other than the conductive particles in the light and thermosetting composition from the viewpoint that the crosslink density required for reducing the connection resistance and improving the connection reliability can be easily obtained. Based on the amount, it may be 5% by mass or more, 10% by mass or more, and 20% by mass or more. The content of the component (A) may be 90% by mass or less based on the total amount of the components other than the conductive particles in the light and the thermosetting composition from the viewpoint of suppressing curing shrinkage during polymerization, and may be 80%. It may be 70% by mass or less, and may be 70% by mass or less. From these viewpoints, the content of the component (A) may be 5 to 90% by mass and 10 to 80% by mass based on the total amount of the components other than the conductive particles in the light and the thermosetting composition. It may be 20 to 70% by mass.

[Component (B): Photopolymerization Initiator]
The component (B) is radicalized by irradiation with light having a wavelength in the range of 150 to 750 nm, preferably light having a wavelength in the range of 254 to 405 nm, and more preferably light having a wavelength in the range of 365 nm (for example, ultraviolet light). , A photopolymerization initiator that generates a cation or an anion (photoradical polymerization initiator, photocationic polymerization initiator or photoanionic polymerization initiator). The component (B) is preferably a photoradical polymerization initiator from the viewpoint of facilitating curing at a low temperature for a short time. As the component (B), one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The photoradical polymerization initiator is decomposed by light to generate free radicals. That is, the photoradical polymerization initiator is a compound that generates radicals by applying light energy from the outside. Examples of the photoradical polymerization initiator include an oxime ester structure, a bisimidazole structure, an acrydin structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethylketal structure, and an α-hydroxy Examples thereof include a photopolymerization initiator having a structure such as an alkylphenone structure.

As the component (B), a photopolymerization initiator having a structure represented by the following formula (I) is preferably used from the viewpoint of further improving the effect of suppressing the flow of conductive particles and the effect of suppressing peeling. The photopolymerization initiator may have a plurality of structures represented by the following formula (I).

The structure represented by the above formula (I) may be an oxime ester structure, a bisimidazole structure or an acridine structure. That is, the light and thermosetting composition comprises a photopolymerization initiator having at least one structure selected from the group consisting of an oxime ester structure, a bisimidazole structure and an acridine structure as the structure represented by the above formula (I). It may be contained. Among these, a photopolymerization initiator having an oxime ester structure is preferably used from the viewpoint of further improving the flow suppressing effect of the conductive particles and the peeling suppressing effect.

As the compound having an oxime ester structure, a compound having a structure represented by the following formula (VI) is preferably used.

In formula (VI), R ¹¹ , R ¹² and R ¹³ each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group.

Specific examples of the compound having an oxime ester structure include 1-phenyl-1,2-butandion-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-benzoyloxime, 1,3-diphenylpropanthrion- 2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxypropanetrione-2- (o-benzoyl) oxime, 1,2-octanedione, 1- [4- (phenylthio) phenyl-, 2-( o-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (o-acetyloxime) and the like.

Examples of the compound having a bisimidazole structure include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer and 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer. , 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4, 5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, etc. Included are 2,4,5-triarylimidazole dimers.

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

The content of the photopolymerization initiator having the structure represented by the above formula (I) is the total amount of the components other than the conductive particles in the light and the thermosetting composition from the viewpoint of further improving the flow suppressing effect of the conductive particles. Is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.45% by mass or more, and particularly preferably 0.55% by mass or more. , Very preferably 0.85% by mass or more. The content of the photopolymerization initiator having the structure represented by the above formula (I) is based on the total amount of components other than the conductive particles in the light and the thermosetting composition from the viewpoint of further improving the effect of suppressing peeling. It is preferably 1.2% by mass or less, more preferably 0.9% by mass or less, and further preferably 0.6% by mass or less. From these viewpoints, the content of the photopolymerization initiator having the structure represented by the above formula (I) is preferably 0, based on the total amount of components other than the conductive particles in the light and the thermosetting composition. It is 1 to 1.2% by mass, more preferably 0.3 to 1.2% by mass, still more preferably 0.45 to 0.9% by mass, and particularly preferably 0.45 to 0.6% by mass. It is mass%.

The content of the component (B) (total content of the photopolymerization initiator) is the total amount of the components other than the conductive particles in the light and the thermosetting composition from the viewpoint of further improving the flow suppressing effect of the conductive particles. Is preferably 0.3% by mass or more, more preferably 0.45% by mass or more, still more preferably 0.55% by mass or more, and particularly preferably 0.85% by mass or more. .. The content of the component (B) is preferably 1.2% by mass or less based on the total amount of the components other than the conductive particles in the light and the thermosetting composition from the viewpoint of further improving the effect of suppressing peeling. Yes, more preferably 0.9% by mass or less, still more preferably 0.6% by mass or less. From these viewpoints, the content of the component (B) is preferably 0.3 to 1.2% by mass, based on the total amount of the components other than the conductive particles in the light and the thermosetting composition. It is preferably 0.45 to 0.9% by mass, and more preferably 0.45 to 0.6% by mass.

[Component (C): Thermal polymerization initiator]
The component (C) may be a thermal polymerization initiator (thermal radical polymerization initiator, thermal cationic polymerization initiator or thermal anion polymerization initiator) that generates radicals, cations or anions by heat, and has an effect of reducing connection resistance. A thermal radical polymerization initiator is preferable from the viewpoint of further improvement and superior connection reliability. As the component (C), one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The thermal radical polymerization initiator decomposes by heat to generate free radicals. That is, the thermal radical polymerization initiator is a compound that generates radicals by applying thermal energy from the outside. The thermal radical polymerization initiator can be arbitrarily selected from conventionally known organic peroxides and azo compounds. As the thermal radical polymerization initiator, an organic peroxide is preferable from the viewpoint of further improving the effect of suppressing the flow of conductive particles and the effect of suppressing peeling, and from the viewpoint of stability, reactivity and compatibility, it is halved for 1 minute. More preferably, an organic peroxide having a period temperature of 90 to 175 ° C. and a weight average molecular weight of 180 to 1000. When the half-life temperature for 1 minute is in this range, the storage stability is further excellent, the radical polymerization property is sufficiently high, and the curing can be performed in a short time.

Specific examples of the component (C) include 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate, and di (2-ethylhexyl) peroxy. Dicarbonate, cumylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate , T-Butylperoxypivalate, 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) Hexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate , Di-t-butylperoxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, t-amylper Oxyneodecanoate, di (3-methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methylbenzoyl) peroxide, t-hexyl peroxyisopropyl monocarbonate, t-butylperoxymaleic acid, t- Butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (3-methylbenzoylperoxy) hexane, t-butylperoxy- 2-Ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dibutylperoxytrimethyl adipate, t-amylperoxynormal Organic peroxides such as octoate, t-amylperoxyisononanoate, t-amylperoxybenzoate; 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis (1-acetoxy) -1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 4,4'-azobis (4-cyanovaleric acid), 1,1 '-Azobis (1-cyclohexanecarbonitrile) And the like, azo compounds and the like.

The content of the component (C) is other than the conductive particles in the first adhesive layer from the viewpoint of excellent quick-curing property, the flow suppressing effect of the conductive particles, and the further improving the peeling suppressing effect. Based on the total amount of the components, it may be 0.1% by mass or more, 0.5% by mass or more, and 1% by mass or more. The content of the component (C) is 20 based on the total mass of the first adhesive layer or the total amount of the components other than the conductive particles in the first adhesive layer from the viewpoint of pot life. It may be 10% by mass or less, may be 10% by mass or less, and may be 5% by mass or less. From these viewpoints, the content of the component (C) may be 0.1 to 20% by mass, 0.5 to 20% by mass, based on the total amount of the components other than the conductive particles in the first adhesive layer. It may be 10% by mass, and may be 1 to 5% by mass. The content of the component (C) based on the total amount of the components other than the conductive particles in the light and the thermosetting composition may be the same as the above range.

[(D) component: conductive particles]
The component (D) is not particularly limited as long as it is a conductive particle, and is a metal particle made of a metal such as Au, Ag, Ni, Cu, or solder, a conductive carbon particle made of conductive carbon, or the like. It may be. The component (D) may be a coated conductive particle containing a nucleus containing non-conductive glass, ceramic, plastic (polystyrene, etc.) and the like, and a coating layer containing the metal or conductive carbon and coating the nucleus. Good. Among these, coated conductive particles including metal particles formed of a heat-meltable metal or a core containing plastic and a coating layer containing metal or conductive carbon and coating the core are preferably used. In this case, since it is easy to deform the cured product of the light and thermosetting composition by heating or pressurizing, the contact area between the electrodes and the component (D) is set when the electrodes are electrically connected to each other. It can be increased to further improve the conductivity between the electrodes.

The component (D) may be an insulating coated conductive particle including the above-mentioned metal particles, conductive carbon particles or coated conductive particles, and an insulating material such as a resin and covering the surface of the particles. .. When the component (D) is an insulating coated conductive particle, even when the content of the component (D) is large, the surface of the particle is coated with a resin, so that a short circuit due to contact between the components (D) occurs. Occurrence can be suppressed, and the insulation between adjacent electrode circuits can be improved. As the component (D), one of the various conductive particles described above may be used alone or in combination of two or more.

The maximum particle size of the component (D) needs to be smaller than the minimum distance between the electrodes (the shortest distance between adjacent electrodes). The maximum particle size of the component (D) 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 conductivity. The maximum particle size of the component (D) may be 50 μm or less, 30 μm or less, or 20 μm or less from the viewpoint of excellent dispersibility and conductivity. From these viewpoints, the maximum particle size of the component (D) may be 1.0 to 50 μm, 2.0 to 30 μm, or 2.5 to 20 μm. In the present specification, the particle size of 300 arbitrary conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the largest value obtained is the maximum particle size of the component (D). And. When the component (D) is not spherical such as having protrusions, the particle size of the component (D) is the diameter of a circle circumscribing the conductive particles in the SEM image.

The average particle size of the component (D) 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 conductivity. The average particle size of the component (D) may be 50 μm or less, 30 μm or less, or 20 μm or less from the viewpoint of excellent dispersibility and conductivity. From these viewpoints, the average particle size of the component (D) may be 1.0 to 50 μm, 2.0 to 30 μm, or 2.5 to 20 μm. In the present specification, the particle size of 300 arbitrary conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the average value of the obtained particle sizes is defined as the average particle size.

In the first adhesive layer 2, the component (D) is preferably uniformly dispersed. Particle density of the component (D) first in the adhesive layer 2, the stable connection resistance is easily obtained standpoint, may be at 100pcs / mm ² or more, may be at 1000pcs / mm ² or more, 2000pcs / It may be mm ² or more. Particle density of the component (D) first in the adhesive layer 2, from the viewpoint of improving the insulating property between adjacent electrodes may be at 100000pcs / mm ² or less, may be at 50000pcs / mm ² or less, It may be 10000 pcs / mm ² or less. From these viewpoints, the particle density of the component (D) in the first adhesive layer 2 may be 100 to 100,000 pcs / mm ² , 1000 to 50,000 pcs / mm ² , and 2,000 to 10,000 pcs / mm ^2. It may be.

The content of the component (D) may be 0.1% by volume or more based on the total volume in the first adhesive layer from the viewpoint of further improving the conductivity, and is 1% by volume or more. It may be 5% by volume or more. The content of the component (D) may be 50% by volume or less, 30% by volume or less, and 20% by volume based on the total volume in the first adhesive layer from the viewpoint of easily suppressing a short circuit. It may be less than or equal to%. From these viewpoints, the content of the component (D) may be 0.1 to 50% by volume or 1 to 30% by volume based on the total volume in the first adhesive layer. It may be up to 20% by volume. The content of the component (D) based on the total product of the light and the thermosetting composition may be the same as the above range.

[Other ingredients]
The light and thermosetting composition may further contain other components other than the component (A), the component (B), the component (C) and the component (D). Other components include, for example, thermoplastic resins, coupling agents, fillers and thermosetting resins. These components may be contained in the first adhesive layer 2.

Examples of the thermoplastic resin include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester urethane resin, acrylic rubber and the like. When the light and thermosetting composition contains a thermoplastic resin, the first adhesive layer can be easily formed. Further, when the light and thermosetting composition contains a thermoplastic resin, the stress of the first adhesive layer generated during the curing of the light and thermosetting composition can be relieved. Further, when the thermoplastic resin has a functional group such as a hydroxyl group, the adhesiveness of the first adhesive layer is likely to be improved. The content of the thermoplastic resin may be, for example, 5% by mass or more, 80% by mass or less, based on the total amount of components other than the conductive particles in the light and the thermosetting composition. It may be up to 80% by mass.

Examples of the coupling agent include a silane coupling agent having an organic functional group such as a (meth) acryloyl group, a mercapto group, an amino group, an imidazole group and an epoxy group, a silane compound such as tetraalkoxysilane, a tetraalkoxy titanate derivative and a polydialkyl. Examples thereof include titanate derivatives. When the light and thermosetting 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 amount of components other than the conductive particles in the light and the thermosetting composition. , 0.1 to 20% by mass.

Examples of the filler include non-conductive fillers (for example, non-conductive particles). When the light and thermosetting 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 fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles; and inorganic fine particles such as nitride fine 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 less than the minimum particle size of the conductive particles 4. The content of the filler may be, for example, 1% by volume or more, 30% by volume or less, and 1 to 30% by volume based on the total volume of the light and the thermosetting composition. ..

The thermosetting resin is a resin that is cured by heat and has at least one thermosetting group. A thermosetting resin is, for example, a compound that crosslinks by reacting with a curing agent by heat. As the thermosetting resin, one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The thermosetting group may be, for example, an epoxy group, an oxetane group, or the like from the viewpoint of further improving the effect of reducing the connection resistance and improving the connection reliability.

Specific examples of the thermosetting resin include bisphenol type epoxy resin which is a reaction product of epichlorohydrin and bisphenol A, F, AD and the like, and epoxy which is a reaction product of epichlorohydrin and phenol novolac, cresol novolac and the like. Examples thereof include novolak resins, naphthalene-based epoxy resins having a skeleton containing a naphthalene ring, and epoxy resins such as various epoxy compounds having two or more glycidyl groups in one molecule such as glycidylamine and glycidyl ether.

The content of the thermosetting resin may be 30% by mass or more, 70% by mass or less, and 30 to 70% based on the total amount of components other than the conductive particles in the first adhesive layer. It may be% by mass.

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

The light and thermosetting composition may contain other additives such as softeners, accelerators, anti-deterioration agents, colorants, flame retardants, thixotropic agents and the like. The content of these additives may be, for example, 0.1 to 10% by mass based on the total amount of components other than the conductive particles in the light and the thermosetting composition. These additives may be contained in the first adhesive layer 2.

The first adhesive layer 2 may contain an unreacted component (B). When the adhesive film 1 of the present embodiment is housed in a conventional storage member and stored and transported, the unreacted component (B) remains in the first adhesive layer 2 during storage and transportation. It is presumed that a part of the thermosetting composition in the second adhesive layer 3 is cured, and the effect of reducing the connection resistance of the adhesive film 1 is reduced. Therefore, when the first adhesive layer 2 contains the component (B), it is possible to prevent a decrease in the effect of reducing the connection resistance by accommodating the adhesive film 1 in the accommodating member described later.

The thickness d1 of the first adhesive layer 2 is 0.1 times or more the average particle size of the conductive particles 4 from the viewpoint that the conductive particles 4 are easily captured between the electrodes facing each other and the connection resistance can be further reduced. It may be 0.2 times or more, and may be 0.3 times or more. The thickness d1 of the first adhesive layer 2 is such that the conductive particles are more easily crushed when the conductive particles are sandwiched between the electrodes facing each other during thermocompression bonding, and the connection resistance can be further reduced. It may be 0.8 times or less, and 0.7 times or less, the average particle size of. From these viewpoints, the thickness d1 of the first adhesive layer 2 may be 0.1 to 0.8 times, and 0.2 to 0.8 times, the average particle size of the conductive particles 4. It may be 0.3 to 0.7 times. The thickness d1 of the first adhesive layer 2 refers to the thickness of the first adhesive layer located at the separated portion of the adjacent

conductive particles

4 and 4.

When the thickness d1 of the first adhesive layer 2 and the average particle size of the conductive particles 4 satisfy the above relationship, for example, as shown in FIG. 1, the conductive particles in the first adhesive layer 2 A part of 4 may protrude from the first adhesive layer 2 toward the second adhesive layer 3. In this case, the boundary S between the first adhesive layer 2 and the second adhesive layer 3 is located at the separated portion of the adjacent

conductive particles

4 and 4. Due to the presence of the boundary S on the conductive particles along the surface of the conductive particles, the conductive particles 4 in the first adhesive layer 2 are moved from the first adhesive layer 2 to the second adhesive layer 3 side. The above relationship may be satisfied without protruding. The conductive particles 4 may not be exposed on the surface 2a of the first adhesive layer 2 opposite to the side of the second adhesive layer 3, and the surface 2a on the opposite side may be a flat surface.

The relationship between the thickness d1 of the first adhesive layer 2 and the maximum particle size of the conductive particles 4 may be the same as described above. For example, the thickness d1 of the first adhesive layer 2 may be 0.1 to 0.8 times, 0.2 to 0.8 times, the maximum particle size of the conductive particles 4, and may be 0. It may be 3 to 0.7 times.

The thickness d1 of the first adhesive layer 2 may be appropriately set according to the height of the electrodes of the circuit member to be adhered. The thickness d1 of the first adhesive layer 2 may be, for example, 0.5 μm or more, 20 μm or less, and 0.5 to 20 μm. When a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 2 (for example, protruding toward the second adhesive layer 3), the second adhesive layer 2 in the first adhesive layer 2 The shortest distance from the surface 2a on the side opposite to the adhesive layer 3 side to the boundary S between the first adhesive layer 2 and the second adhesive layer 3 located at the separated portions of the adjacent

conductive particles

4 and 4. (Distance indicated by d1 in FIG. 1) 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, 20 μm or less, and 0.1 to 20 μm.

The thickness of the adhesive layer can be measured by the following method. First, the adhesive film is sandwiched between two pieces of glass (thickness: about 1 mm). Next, a resin composition consisting of 100 g of a bisphenol A type epoxy resin (trade name: JER811, manufactured by Mitsubishi Chemical Co., Ltd.) and 10 g of a curing agent (trade name: Epomount curing agent, manufactured by Refine Tech Co., Ltd.) is cast. .. Then, the cross section is polished using a polishing machine, and the thickness of each adhesive layer is measured using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Co., Ltd.).

(Second adhesive layer)
The second adhesive layer 3 contains, for example, (a) a polymerizable compound (hereinafter, also referred to as (a) component) and (b) a thermal polymerization initiator (hereinafter, also referred to as (b) component). It consists of a thermosetting composition. The thermosetting composition constituting the second adhesive layer 3 is a thermosetting composition that can flow when connected to a circuit, and is, for example, an uncured thermosetting composition.

[Component (a): polymerizable compound]
The component (a) is, for example, a compound polymerized by radicals, cations or anions generated by a thermal polymerization initiator by heat. As the component (a), the compound exemplified as the component (A) can be used. The component (a) is a radically polymerizable compound having a radically polymerizable group that reacts with radicals from the viewpoint of facilitating connection at low temperature for a short time, further improving the effect of reducing connection resistance, and improving connection reliability. Is preferable. Examples of the preferred radically polymerizable compound in the component (a) and the combination of the preferred radically polymerizable compound are the same as those in the component (A). When the component (a) is a radically polymerizable compound and the component (B) in the first adhesive layer is a photoradical polymerization initiator, it is adhered by accommodating the adhesive film in an accommodating member described later. Curing of the thermosetting composition during storage or transportation of the agent film tends to be significantly suppressed.

The component (a) 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) may be the same as or different from the component (A).

The content of the component (a) is 10% by mass or more based on the total mass of the thermosetting composition from the viewpoint that the crosslink density required for reducing the connection resistance and improving the connection reliability can be easily obtained. It may be 20% by mass or more, and may be 30% by mass or more. The content of the component (a) may be 90% by mass or less based on the total mass of the thermosetting composition from the viewpoint that curing shrinkage during polymerization can be suppressed and good reliability can be obtained. It may be 80% by mass or less, and may be 70% by mass or less. From these viewpoints, the content of the component (a) may be 10 to 90% by mass, 20 to 80% by mass, and 30 to 70% by mass based on the total mass of the thermosetting composition. It may be.

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

The content of the component (b) may be 0.1% by mass or more based on the total mass of the thermosetting composition, and may be 0, from the viewpoint of further improving the effect of reducing the connection resistance and improving the connection reliability. It may be 5.5% by mass or more, and may be 1% by mass or more. The content of the component (b) may be 30% by mass or less, 20% by mass or less, and 10% by mass or less based on the total mass of the thermosetting composition from the viewpoint of pot life. You can. From these viewpoints, the content of the component (b) may be 0.1 to 30% by mass or 0.5 to 20% by mass based on the total mass of the thermosetting composition. It may be up to 10% by mass.

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

The thermosetting composition may contain the above-mentioned thermosetting resin in place of the components (a) and (b), or in addition to the components (a) and (b). In this case, the thermosetting composition may contain a curing agent used for curing the thermosetting resin described above. When a thermosetting resin is used instead of the component (a) and the component (b), the content of the thermosetting resin in the thermosetting composition is, for example, 20 based on the total mass of the thermosetting composition. It may be 0% by mass or more, 80% by mass or less, and 20 to 80% by mass. When a thermosetting resin is used in addition to the components (a) and (b), the content of the thermosetting resin in the thermosetting composition is, for example, 20 based on the total mass of the thermosetting composition. It may be 0% by mass or more, 80% by mass or less, and 20 to 80% by mass. The content of the curing agent may be the same as the range described as the content of the curing agent in the light and thermosetting composition.

The content of the conductive particles 4 in the second adhesive layer 3 may be, for example, 1% by mass or less, or 0% by mass, based on the total mass of the second adhesive layer. The second adhesive layer 3 preferably does not contain the conductive particles 4.

The thickness d2 of the second adhesive layer 3 may be appropriately set according to the height of the electrodes of the circuit member to be adhered. The thickness d2 of the second adhesive layer 3 may be 5 μm or more from the viewpoint that the space between the electrodes can be sufficiently filled to seal the electrodes and better connection reliability can be obtained. , 200 μm or less, and may be 5 to 200 μm. When a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 2 (for example, protruding toward the second adhesive layer 3), the first in the second adhesive layer 3 The distance from the surface 3a on the side opposite to the adhesive layer 2 side to the boundary S between the first adhesive layer 2 and the second adhesive layer 3 located at the separated portions of the adjacent conductive particles 4 and 4 ( The distance indicated by d2 in FIG. 1) 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 (thickness d1 of the first adhesive layer 2 1 / thickness d2 of the second adhesive layer 3) May be 1 or more, and may be 100 or less, from the viewpoint that the space between the electrodes can be sufficiently filled to seal the electrodes and better reliability can be obtained.

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

In the adhesive film 1, the conductive particles 4 are dispersed in the first adhesive layer 2. Therefore, the adhesive film 1 is an anisotropically conductive adhesive film having anisotropic conductivity. The adhesive film 1 is interposed between the first circuit member having the first electrode and the second circuit member having the second electrode, and heats the first circuit member and the second circuit member. It is crimped and used to electrically connect the first and second electrodes to each other.

According to the adhesive film 1, the flow of conductive particles generated during the manufacture of the circuit connection structure can be suppressed. Further, according to the adhesive film 1, peeling at the interface between the circuit member and the circuit connection portion formed by the adhesive film, which occurs when the circuit connection structure is used in a high temperature and high humidity environment, is suppressed. There is a tendency to be able to do it.

Although the circuit connection adhesive film of the present embodiment has been described above, the present invention is not limited to the above embodiment.

For example, the adhesive film for circuit connection may be composed of two layers, a first adhesive layer and a second adhesive layer, other than the first adhesive layer and the second adhesive layer. It may be composed of three or more layers including a layer (for example, a third adhesive layer). The third adhesive layer may be a layer having the same composition as that described above for the first adhesive layer or the second adhesive layer, and may be the first adhesive layer or the second adhesive layer. It may be a layer having the same thickness as the above-mentioned thickness. The circuit connection adhesive film may further include, for example, a third adhesive layer on the opposite surface of the second adhesive layer in the first adhesive layer. That is, the circuit connection adhesive film is formed by, for example, laminating a second adhesive layer, a first adhesive layer, and a third adhesive layer in this order. In this case, the third adhesive layer is made of, for example, a thermosetting composition like the second adhesive layer.

Further, the circuit connection adhesive film of the above embodiment is an anisotropically conductive adhesive film having anisotropic conductivity, but the circuit connection adhesive film is conductive and does not have anisotropic conductivity. It may be an adhesive film.

<Manufacturing method of adhesive film for circuit connection>
The method for manufacturing the circuit connection adhesive film 1 of the present embodiment is, for example, a preparation step for preparing the first adhesive layer 2 described above (first preparation step) and a method for producing the adhesive film 1 for circuit connection on the first adhesive layer 2. It includes a laminating step of laminating the second adhesive layer 3 described above. The method for manufacturing the circuit connection adhesive film 1 may further include a preparation step (second preparation step) for preparing the second adhesive layer 3.

In the first preparation step, for example, the first adhesive layer 2 is prepared by forming the first adhesive layer 2 on the base material to obtain the first adhesive film. Specifically, first, the component (A), the component (B), the component (C), and the component (D), and other components added as needed are added to the organic solvent and mixed by stirring. A varnish composition (a varnish of a light and thermosetting composition) is prepared by dissolving or dispersing by kneading or the like. Then, the varnish composition is applied onto the release-treated substrate using a knife coater, roll coater, applicator, comma coater, die coater, etc., and then the organic solvent is volatilized by heating to form the substrate. Form a layer of light and thermosetting composition. Subsequently, the light and the thermosetting composition are cured (photocured) by irradiating the layer composed of the light and the thermosetting composition with light, and the first adhesive layer 2 is formed on the base material. Form (curing step). As a result, the first adhesive film is obtained.

The organic solvent used for preparing the varnish composition preferably has the property of uniformly dissolving or dispersing each component, and for example, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate and the like. Can be mentioned. These organic solvents can be used alone or in combination of two or more. Stirring and mixing and kneading in the preparation of the varnish composition can be carried out by using, for example, a stirrer, a raft machine, a triple roll, a ball mill, a bead mill or a homodisper.

The base material is not particularly limited as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized. For example, stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, and polyethylene iso Substrate made of phthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene / vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer, etc. For example, film) can be used.

The heating conditions for volatilizing the organic solvent from the varnish composition applied to the base material are preferably conditions in which the organic solvent volatilizes sufficiently. The heating conditions may be, for example, 40 ° C. or higher and 120 ° C. or lower for 0.1 minute or longer and 10 minutes or shorter.

For the irradiation of light in the curing step, it is preferable to use irradiation light (for example, ultraviolet light) having a wavelength in the range of 150 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, an LED light source, or the like. The irradiation amount of light is not particularly limited, and for example, the integrated light amount of light having a wavelength of 365 nm may be 100 mJ / cm ² or more, 200 mJ / cm ² or more, and 300 mJ / cm ² or more. Good. The dose of light, for example, an accumulated light quantity of the wavelength 365nm light, may be at 10000 mJ / cm ² or less, may be at 5000 mJ / cm ² or less, may be at 3000 mJ / cm ² or less.

In the second preparation step, the same as in the first preparation step, except that the components (a) and (b) and other components added as needed are used and no light irradiation is performed. The second adhesive layer 3 is prepared by forming the second adhesive layer 3 on the base material to obtain the second adhesive film.

In the laminating step, the second adhesive layer 3 may be laminated on the first adhesive layer 2 by laminating the first adhesive film and the second adhesive film, and the first A varnish composition (thermosetting composition varnish) obtained by using the components (a) and (b) and other components added as needed is applied onto the adhesive layer 2 and is organic. The second adhesive layer 3 may be laminated on the first adhesive layer 2 by volatilizing the solvent. The laminating step may be performed in the middle of the first preparation step. For example, after forming a layer composed of a light and a thermosetting composition, a laminating step is performed to obtain a layer composed of the light and a thermosetting composition (a precursor of the first adhesive layer 2) and a thermosetting composition. A laminated body including a layer made of (second adhesive layer 3) may be obtained. In this case, the obtained laminate may be irradiated with light to cure the layer composed of the light and the thermosetting composition, and the first preparation step may be completed.

Examples of the method of adhering the first adhesive film and the second adhesive film include methods such as heat pressing, roll laminating, and vacuum laminating. Lamination may be performed, for example, under temperature conditions of 0 to 80 ° C.

<Circuit connection structure and its manufacturing method>
Hereinafter, a circuit connection structure using the above-mentioned circuit connection adhesive film 1 as a circuit connection material and a method for manufacturing the same will be described.

FIG. 2 is a schematic cross-sectional view showing a circuit connection structure of one embodiment. As shown in FIG. 2, the circuit connection structure 10 includes a first circuit member 13 having a first electrode 12 formed on the main surface 11a of the first circuit board 11 and the first circuit board 11. , A second circuit member 16 having a second electrode 15 formed on the main surface 14a of the second circuit board 14 and the second circuit board 14, and the first circuit member 13 and the second circuit member. A circuit connecting portion 17 which is arranged between 16 and electrically connects the first electrode 12 and the second electrode 15 to each other is provided.

The first circuit member 13 and the second circuit member 16 may be the same 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, or the like. The first circuit board 11 and the second circuit board 14 may be formed of an inorganic substance such as semiconductor, glass or ceramic, an organic substance such as polyimide or polycarbonate, or a composite such as glass / epoxy. The first electrode 12 and the second electrode 15 are gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, indium tin oxide (ITO), and indium zinc oxide. It may be made of a substance (IZO), indium gallium zinc oxide (IGZO), or the like. 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 made of a cured product of the adhesive film 1 described above. The circuit connection portion 17 is located, for example, 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, “opposing direction”), and the above-mentioned light and It is located on the side of the first region 18 made of a cured product of a component other than the conductive particles 4 of the thermosetting composition and the second circuit member 16 in the opposite direction, and is composed of the cured product of the above-mentioned thermocurable composition. It has a second region 19 and conductive particles 4 that are interposed between at least the first electrode 12 and the second electrode 15 and electrically connect the first electrode 12 and the second electrode 15 to each other. .. The circuit connection portion does not have to have two regions as in the first region 18 and the second region 19, for example, components other than the conductive particles 4 of the above-mentioned light and thermosetting composition. It may consist of a cured product in which the cured product and the cured product of the above-mentioned thermosetting composition are mixed.

FIG. 3 is a schematic cross-sectional view showing a method of manufacturing the circuit connection structure 10. As shown in FIG. 3, a method of manufacturing the circuit connection structure 10 is, for example, between a first circuit member 13 having a first electrode 12 and a second circuit member 16 having a second electrode 15. The above-mentioned adhesive film 1 is interposed, the first circuit member 13 and the second circuit member 16 are thermocompression bonded, and the first electrode 12 and the second electrode 15 are electrically connected to each other. To be equipped.

Specifically, as shown in FIG. 3A, first, a first circuit including the first circuit board 11 and the first electrode 12 formed on the main surface 11a of the first circuit board 11. A member 13 and a second circuit member 16 having a second electrode 15 formed on the main surface 14a of the second circuit board 14 and the second circuit board 14 are prepared.

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

Then, as shown in FIG. 3B, the first circuit member 13 and the second circuit member 16 are heated while heating the first circuit member 13, the adhesive film 1 and the second circuit member 16. By pressurizing in the thickness direction, the first circuit member 13 and the second circuit member 16 are thermocompression bonded to each other. At this time, as shown by an arrow in FIG. 3B, since the second adhesive layer 3 is made of a flowable uncured thermosetting composition, it is between the

second electrodes

15 and 15. It flows so as to fill the voids and is cured by the above heating. As a result, the first electrode 12 and the second electrode 15 are electrically connected to each other via the conductive particles 4, and the first circuit member 13 and the second circuit member 16 are adhered to each other. The circuit connection structure 10 shown in 2 is obtained. In the method for manufacturing the circuit connection structure 10 of the present embodiment, since the first adhesive layer 2 is a pre-cured layer, the conductive particles 4 are fixed in the first adhesive layer 2 and also. Since the first adhesive layer 2 hardly flows during the thermocompression bonding and the conductive particles are efficiently captured between the facing electrodes, the connection resistance between the facing

electrodes

12 and 15 is reduced. Therefore, a circuit connection structure having excellent connection reliability can be obtained.

<Adhesive film storage set>
FIG. 4 is a perspective view showing an adhesive film accommodating set of one embodiment. As shown in FIG. 4, the adhesive film accommodating set 20 includes an adhesive film 1 for circuit connection, a reel 21 around which the adhesive film 1 is wound, and an accommodating member 22 accommodating the adhesive film 1 and the reel 21. And.

As shown in FIG. 4, the adhesive film 1 is, for example, in the form of a tape. The tape-shaped adhesive film 1 is produced, for example, by cutting a sheet-shaped raw fabric into a long length with a width suitable for the intended use. A base material may be provided on one surface of the adhesive film 1. As the base material, a base material such as the PET film described above can be used.

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

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

The winding core 23 of the first side plate 24 is a portion around which the adhesive film 1 is wound. The winding core 23 is made of, for example, plastic, and has an annular shape having a thickness similar to the width of the adhesive film 1. The winding core 23 is fixed to the inner side surface of the first side plate 24 so as to surround the opening of the first side plate 24. Further, a shaft hole 26, which is a portion into which a rotating shaft of a winding device or a feeding device (not shown) is inserted, is provided in the central portion of the reel 21. When the rotating shaft is driven with the rotating shaft of the winding device or the feeding device inserted into the shaft hole 26, the reel 21 rotates without idling. A desiccant container containing a desiccant may be fitted in the shaft hole 26.

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

The accommodating member 22 has a bag shape, for example, and accommodates the adhesive film 1 and the reel 21. The accommodating member 22 has an insertion port 27 for accommodating (inserting) the adhesive film 1 and the reel 21 inside the accommodating member 22.

The accommodating member 22 has a visual recognition portion 28 that makes the inside of the accommodating member 22 visible from the outside. The accommodating member 22 shown in FIG. 4 is configured such that the entire accommodating member 22 serves as a visual recognition portion 28.

The visual recognition unit 28 has transparency to visible light. For example, when the light transmittance in the visual recognition unit 28 is measured in the wavelength range of 450 to 750 nm, the average value of the light transmittance is 30% or more between the wavelengths of 450 to 750 nm, and the wavelength width is 50 nm. There is at least one region. The light transmittance of the visual recognition unit 28 is obtained by preparing a sample obtained by cutting the visual recognition unit 28 to a predetermined size and measuring the light transmittance of the sample with an ultraviolet-visible spectrophotometer. Since the accommodating member 22 has such a visual recognition portion 28, various information such as a product name, a lot number, and an expiration date affixed to the reel 21 inside the accommodating member 22 can be confirmed from the outside of the accommodating member 22. be able to. This can be expected to prevent mixing of different products and to improve the efficiency of sorting work.

The transmittance of light having a wavelength of 365 nm in the visual recognition unit 28 is 10% or less. Since the transmission of light having a wavelength of 365 nm in the visual recognition unit 28 is 10% or less, it is caused by the light incident from the outside to the inside of the accommodating member 22 and the photopolymerization initiator remaining in the first adhesive layer 2. It is possible to suppress the curing of the thermosetting composition. As a result, the effect of reducing the connection resistance of the adhesive film 1 can be maintained, and when the adhesive film 1 is used for connecting the circuit members, the connection resistance between the opposing electrodes can be reduced. From the viewpoint of further suppressing the generation of radicals from the photopolymerization initiator, the transmittance of light having a wavelength of 365 nm in the visual recognition unit 28 is preferably 10% or less, more preferably 5% or less, still more preferably 1% or less. Particularly preferably, it is 0.1% or less.

From the same viewpoint, the maximum value of the light transmittance in the wavelength region in which the above-mentioned photopolymerization initiator (component (B)) can generate radicals, cations or anions in the visual recognition unit 28 is preferable. It is 10% or less, more preferably 5% or less, still more preferably 1% or less, and particularly preferably 0.1% or less. Specifically, the maximum value of the light transmittance in the viewing unit 28 at a wavelength of 254 to 405 nm is preferably 10% or less, more preferably 5% or less, still more preferably 1% or less, and particularly preferably 0.1%. It is as follows.

The visual recognition portion 28 (accommodating member 22) is formed of, for example, a sheet having a thickness of 10 to 5000 μm. The sheet is made of a material having a transmittance of light having a wavelength of 365 nm in the visual recognition unit 28 of 10% or less. Such a material may consist of one type of component or may consist of a plurality of types of components. Examples of the material include low-density polyethylene, linear low-density polyethylene, polycarbonate, polyester, polyacrylate, polyamide, glass and the like. These materials may contain UV absorbers. The visual recognition unit 28 may have a laminated structure formed by laminating a plurality of layers having different light transmission characteristics. In this case, each layer constituting the visual recognition unit 28 may be made of the above-mentioned material.

The insertion port 27 may be sealed by, for example, being closed by a sealing machine or the like in order to prevent air from entering from the outside during accommodation. In this case, it is preferable to suck and remove the air in the accommodating member 22 before closing the insertion port 27. It can be expected that the humidity inside the accommodating member 22 will be reduced from the initial stage of accommodating, and that air will be prevented from entering from the outside. Further, when the inner surface of the accommodating member 22 and the reel 21 are in close contact with each other, the inner surface of the accommodating member 22 and the surface of the reel 21 rub against each other due to vibration during transportation to generate foreign matter, and the side plate 24 of the

reel

21 , 25 can be prevented from being scratched on the outer surface.

In the above embodiment, the accommodating member is configured so that the entire accommodating member serves as a visible portion, but in another embodiment, the accommodating member has a visible portion as a part of the accommodating member. May be good. For example, the accommodating member may have a rectangular visible portion substantially in the center of the side surface of the accommodating member. In this case, the portion of the accommodating member other than the visible portion may be black, for example, so as not to transmit ultraviolet light and visible light.

Further, in the above embodiment, the shape of the accommodating member is bag-shaped, but the accommodating member may be, for example, box-shaped. The accommodating member preferably has a notch for opening. In this case, the opening work at the time of use becomes easy.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples.

<Synthesis of polyurethane acrylate (UA1)>
Poly (1,6-hexanediol carbonate) (trade name: Duranol T5652, manufactured by Asahi Kasei Chemicals Co., Ltd.) in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser having a calcium chloride drying tube, and a nitrogen gas introduction tube. , 2500 parts by mass (2.50 mol) with a number average molecular weight of 1000) and 666 parts by mass (3.00 mol) of isophorone diisocyanate (manufactured by Sigma Aldrich) were uniformly added dropwise over 3 hours. Then, after sufficiently introducing nitrogen gas into the reaction vessel, the inside of the reaction vessel was heated to 70 to 75 ° C. for reaction. Next, 0.53 parts by mass (4.3 mmol) of hydroquinone monomethyl ether (manufactured by Sigma-Aldrich) and 5.53 parts by mass (8.8 mmol) of dibutyltin dilaurate (manufactured by Sigma-Aldrich) were added to the reaction vessel. After that, 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 atmosphere. As a result, 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 gel permeation chromatography (GPC) using a standard polystyrene calibration curve according to the following conditions.
(Measurement condition)
Equipment: GPC-8020 manufactured by Tosoh Corporation
Detector: RI-8020 manufactured by Tosoh Corporation
Column: Gelpack GLA160S + GLA150S manufactured by Hitachi Chemical Company, Ltd.
Sample concentration: 120 mg / 3 mL
Solvent: Tetrahydrofuran Injection volume: 60 μL
Pressure: 2.94 x 10 ⁶ Pa (30 kgf / cm ² )
Flow rate: 1.00 mL / min

<Making conductive particles>
A layer made of nickel was formed on the surface of the polystyrene particles so that the thickness of the layer was 0.2 μm. In this way, conductive particles having an average particle size of 4 μm, a maximum particle size of 4.5 μm, and a specific gravity of 2.5 were obtained.

<Preparation method of polyester urethane resin>
48 parts by mass of isophthalic acid and 37 parts by mass of neopentyl glycol were put into a heated stainless steel autoclave equipped with a stirrer, a thermometer, a condenser, a vacuum generator and a nitrogen gas introduction tube, and tetrabutoxytitanate as a catalyst was added. 0.02 parts by mass was charged. Then, the temperature was raised to 220 ° C. under a nitrogen stream, and the mixture was stirred as it was for 8 hours. Then, the pressure was reduced to atmospheric pressure (760 mmHg), and the mixture was cooled to room temperature. As a result, a white precipitate was precipitated. Then, the white precipitate was taken out, washed with water, and vacuum dried to obtain a polyester polyol. The obtained polyester polyol was sufficiently dried, then dissolved in MEK (methyl ethyl ketone), and placed in a four-necked flask equipped with a stirrer, a dropping funnel, a reflux cooler and a nitrogen gas introduction tube. Further, dibutyltin laurate was added as a catalyst in an amount of 0.05 parts by mass with respect to 100 parts by mass of the polyester polyol, and 4,4'-diphenylmethane diisocyanate in an amount of 50 parts by mass with respect to 100 parts by mass of the polyester polyol was added. It was dissolved in MEK, charged with a dropping funnel, and stirred at 80 ° C. for 4 hours to obtain the desired polyester urethane resin.

<Preparation of varnish (varnish composition) of light and thermosetting composition>
The components shown below were mixed in the blending amounts (parts by mass) shown in Table 1 to prepare varnishes for light and thermosetting compositions 1 to 8.

(Polymerizable compound)
A1: Dicyclopentadiene type diacrylate (trade name: DCP-A, manufactured by Toagosei Co., Ltd.)
A2: Polyurethane acrylate synthesized as described above (UA1)
A3: 2-methacryloyloxyethyl acid phosphate (trade name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.)
(Photopolymerization initiator)
B1: 1,2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (O-benzoyloxime)] (trade name: Irgacure (registered trademark) OXE01, manufactured by BASF)
B2: Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (o-acetyloxime) (trade name: Irgacure (registered trademark) OXE02, BASF Made by the company)
(Thermal polymerization initiator)
C1: Benzoyl peroxide (trade name: Niper BMT-K40, manufactured by NOF CORPORATION)
(Conductive particles)
D1: Conductive particles (thermoplastic resin) prepared as described above
E1: Polyester urethane resin (coupling agent) synthesized as described above
F1: 3-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.)
(Filler)
G1: Silica fine particles (trade name: R104, manufactured by Nippon Aerosil Co., Ltd., average particle size (primary particle size): 12 nm)
(solvent)
H1: Methyl ethyl ketone

<Preparation of thermosetting composition varnish (varnish composition)>
As polymerizable compounds a1 to a3, thermal polymerization initiator b1, coupling agent f1, filler g1 and solvent h1, the polymerizable compounds A1 to A3 in the light and thermosetting composition, the thermal polymerization initiator C1, and the coupling agent. Using the same materials as F1, the filler G1 and the solvent H1, the thermoplastic resin e1 uses the components shown below, and these components are mixed in the blending amounts (parts by mass) shown in Table 2, and the thermosetting composition 1 is used. Varnish was prepared.
(Thermoplastic resin)
e1: Phenoxy resin (trade name: PKHC, manufactured by Union Carbide)

(Example 1)
[Preparation of the first adhesive film]
The varnish of the light and thermosetting composition 1 was applied onto a PET film having a thickness of 50 μm using a coating device. Next, hot air drying was performed at 70 ° C. for 3 minutes to form a layer composed of light and a thermosetting composition 1 having a thickness (thickness after drying) of 4 μm on the PET film. The thickness here was measured using a contact type thickness gauge. When a contact type thickness gauge is used, the size of the conductive particles is reflected, and the thickness of the region where the conductive particles are present is measured. Therefore, after laminating the second adhesive layer to prepare an adhesive film for circuit connection having a two-layer structure, the thickness of the first adhesive layer located at the separated portion of the adjacent conductive particles is obtained by the method described later. Was measured.

Next, the layer composed of light and the thermosetting composition 1 was irradiated with light using a metal halide lamp so that the integrated light amount was 1500 mJ / cm ² , and the polymerizable compound was polymerized. As a result, the light and thermosetting composition 1 was cured to form a first adhesive layer. By the above operation, a first adhesive film having a first adhesive layer on the PET film (thickness of the region where the conductive particles are present: 4 μm) was obtained. The conductive particle density at this time was about 7000 pcs / mm ² .

[Preparation of second adhesive film]
The varnish of the thermosetting composition 1 was applied onto a PET film having a thickness of 50 μm using a coating device. Next, hot air drying was performed at 70 ° C. for 3 minutes to form a second adhesive layer (layer composed of the thermosetting composition 1) having a thickness of 8 μm on the PET film. By the above operation, a second adhesive film having a second adhesive layer on the PET film was obtained.

[Preparation of adhesive film for circuit connection]
The first adhesive film and the second adhesive film were arranged so that their respective adhesive layers faced each other, and were laminated with a roll laminator while being heated at 40 ° C. together with a PET film as a base material. As a result, a circuit connection adhesive film having a two-layer structure in which the first adhesive layer and the second adhesive layer were laminated was produced.

The thickness of the first adhesive layer of the produced adhesive film for circuit connection was measured by the following method. First, an adhesive film for circuit connection is sandwiched between two pieces of glass (thickness: about 1 mm), 100 g of bisphenol A type epoxy resin (trade name: JER811, manufactured by Mitsubishi Chemical Co., Ltd.) and a curing agent (trade name: Epomount). It was cast with a resin composition consisting of 10 g of a curing agent (manufactured by Refine Tech Co., Ltd.). After that, the cross section is polished using a polishing machine, and a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Co., Ltd.) is used to perform the first first located at a separated portion of adjacent conductive particles. The thickness of the adhesive layer was measured. The thickness of the first adhesive layer was 2 μm.

[Manufacturing of circuit connection structure]
A thin film electrode provided with a COF (manufactured by FLEXSEED) having a pitch of 25 μm and a thin film electrode (height: 1200Å) made of non-crystalline indium tin oxide (ITO) on a glass substrate via the produced adhesive film for circuit connection. The width of the glass substrate with a glass substrate (manufactured by Geomatec) is heated and pressurized at 170 ° C. and 6 MPa for 4 seconds using a heat crimping device (heating method: constant heat type, manufactured by Taiyo Kikai Co., Ltd.). A circuit connection structure (connection structure) was produced by connecting over 1 mm. At the time of connection, the circuit connection adhesive film was arranged on the glass substrate so that the surface of the circuit connection adhesive film on the first adhesive layer side faced the glass substrate.

<Evaluation of circuit connection structure>
[Evaluation of particle fluidity]
With respect to the obtained circuit connection structure, the particle flow state of the resin exuded portion of the circuit connection adhesive film was evaluated using a microscope (trade name: ECLIPSE L200, manufactured by Nikon Corporation). Specifically, the produced circuit connection structure was observed from the glass substrate side with a microscope, and the particle state of the portion exuded outside the width of the circuit connection adhesive film was evaluated in three stages. The state where the particles hardly move and there are no particles in the exuded part 1. The state where the particles move a little but the particles are not connected to each other 2. The state where the particles flow and the particles are connected to each other. Was set to 3.

[Evaluation of connection resistance]
With respect to the obtained circuit connection structure, the connection resistance value between the opposing electrodes immediately after the connection and after the high temperature and high humidity test was measured with a multimeter. The high temperature and high humidity test was carried out by leaving it in a constant temperature and humidity chamber at 85 ° C. and 85% RH for 200 hours. The connection resistance value was determined as the average value of 16 resistance points between the opposing electrodes.

[Peeling evaluation]
The presence or absence of peeling at the circuit connection portion of the circuit connection structure after the high temperature and high humidity test was evaluated using a microscope (trade name: ECLIPSE L200, manufactured by Nikon Corporation). Specifically, the circuit connection structure produced as described above was observed from the glass substrate side with a microscope, and the peeled state between the glass substrate and the circuit connection adhesive film was evaluated in three stages. The ratio of peeling from the glass substrate in the total area of the adhesive film for circuit connection was calculated, and the one with almost no peeling (the ratio of the peeled part was less than 5% of the total) was A, and a small amount of peeling occurred. (The ratio of the peeled portion is 5% or more and less than 20% of the whole) is designated as B, and the peeled portion (the ratio of the peeled portion is 20% or more of the whole) is designated as C.

(Examples 2 to 7 and Comparative Example 1)
An adhesive film for circuit connection and a circuit connection structure were prepared and carried out in the same manner as in Example 1 except that the light and thermosetting compositions 2 to 8 were used as the light and thermosetting compositions. The circuit connection structure was evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4.

1 ... Circuit connection adhesive film, 2 ... First adhesive layer, 3 ... Second adhesive layer, 4 ... Conductive particles, 10 ... Circuit connection structure, 12 ... Circuit electrode (first electrode), 13 ... 1st circuit member, 15 ... Bump electrode (2nd electrode), 16 ... 2nd circuit member, 20 ... Adhesive film accommodating set, 22 ... Accommodating member, 28 ... Visible part.

Claims

A first adhesive layer and a second adhesive layer laminated on the first adhesive layer are provided.
The first adhesive layer comprises a photocurable product of a light and thermosetting composition containing a polymerizable compound, a photopolymerization initiator, a thermopolymerization initiator, and conductive particles.
The second adhesive layer is an adhesive film for circuit connection, which is made of a thermosetting composition.
The circuit connection adhesive film according to claim 1, wherein the polymerizable compound is a radically polymerizable compound having a radically polymerizable group.
The adhesive film for circuit connection according to claim 1 or 2, wherein the polymerizable compound contains a radically polymerizable compound having a phosphoric acid ester structure represented by the following formula (1).

[In formula (1), n represents an integer of 1 to 3, and R represents a hydrogen atom or a methyl group. ]
The circuit connection adhesive film according to any one of claims 1 to 3, wherein the thermosetting composition contains a radically polymerizable compound having a radically polymerizable group.
The circuit connection adhesive film according to any one of claims 1 to 4, wherein the photopolymerization initiator has a structure represented by the following formula (I).
The circuit connection adhesive film according to claim 5, wherein the structure represented by the formula (I) is an oxime ester structure, a bisimidazole structure, or an acridine structure.
The circuit connection adhesive film according to any one of claims 1 to 6, wherein the photopolymerization initiator contains a compound having a structure represented by the following formula (VI).

[In the formula (VI), R 11 , R 12 and R 13 each independently represent an organic group containing a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group. ]
The adhesive film for circuit connection according to any one of claims 1 to 7, wherein the thickness of the first adhesive layer is 0.1 to 0.8 times the average particle size of the conductive particles. ..
The preparation process for preparing the first adhesive layer and
A laminating step of laminating a second adhesive layer made of a thermosetting composition on the first adhesive layer is provided.
In the preparation step, the light is irradiated by irradiating a layer composed of a light containing a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, and conductive particles and a thermosetting composition. A method for producing an adhesive film for circuit connection, which comprises a step of curing the thermosetting composition to obtain the first adhesive layer.
The method for producing an adhesive film for circuit connection according to claim 9, wherein the polymerizable compound is a radically polymerizable compound having a radically polymerizable group.
The method for producing an adhesive film for circuit connection according to claim 9 or 10, wherein the thermosetting composition contains a radically polymerizable compound having a radically polymerizable group.
The adhesive film for circuit connection according to any one of claims 9 to 11, wherein the thickness of the first adhesive layer is 0.1 to 0.8 times the average particle size of the conductive particles. Manufacturing method.
The circuit connection adhesive film according to any one of claims 1 to 8 is interposed between the first circuit member having the first electrode and the second circuit member having the second electrode. A method for manufacturing a circuit connection structure, comprising a step of thermally crimping the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other. ..
The circuit connecting adhesive film according to any one of claims 1 to 8 and an accommodating member for accommodating the adhesive film are provided.
The accommodating member has a visual recognition portion that makes the inside of the accommodating member visible from the outside.
An adhesive film accommodating set in which the transmittance of light having a wavelength of 365 nm in the visible portion is 10% or less.