JP2022048791A - Circuit connection adhesive film, as well as, circuit connection structure and manufacturing method thereof - Google Patents

Abstract

To provide a circuit connection adhesive film capable of sufficiently securing conduction between opposite electrodes of circuit members, and further capable of obtaining a circuit connection structure excellent in peel resistance under a high temperature and high humidity environment, as well as, a circuit connection structure using the adhesive film and its manufacturing method.SOLUTION: An adhesive film for circuit connection comprises conductive particles, in which the conductive particles are unevenly arranged on one surface side of the adhesive film, and the adhesive film includes a region S comprising a thermosetting composition that does not include conductive particles in a thickness direction of the film, the region S includes a region HF1 which is 5 to 50 mass% of a filler in a thickness direction of the film, and a ratio of the width of the region HF1 to the width of the region S is 1 to 26.5%.SELECTED DRAWING: None

Description

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

Conventionally, various adhesive materials have been used for circuit connection. For example, as an adhesive material for connecting a liquid crystal display to a tape carrier package (TCP), a flexible printed wiring board (FPC) to TCP, or an FPC to 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 the 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

By the way, due to the decrease in the adhesive area due to the narrowing of the frame of the liquid crystal display, the level of connection reliability required for the adhesive film for circuit connection is increasing. Therefore, the present inventors investigated the connection reliability of the adhesive film for circuit connection in which conductive particles are unevenly distributed on one side of the adhesive film, and found that the circuit connection structure after connection is in a high temperature and high humidity environment. It has become clear that when used for a long period of time (for example, 85 ° C., 85% RH), peeling may occur between the circuit connection portion and the circuit member. When such peeling occurs, there is a concern that the connection reliability may decrease due to an increase in the connection resistance value and a decrease in the adhesive force.

Therefore, according to the present invention, it is possible to sufficiently secure the conduction between the facing electrodes of the circuit member, and to obtain a circuit connection structure having excellent peeling resistance in a high temperature and high humidity environment. It is an object of the present invention to provide an agent film, a circuit connection structure using the adhesive film, and a method for producing the same.

In order to solve the above problems, one aspect of the present invention is an adhesive film for circuit connection containing conductive particles, in which the conductive particles are unevenly distributed on one side of the adhesive film, and the adhesive film is formed. In the thickness direction of the film, the region S includes a region S made of a thermosetting composition containing no conductive particles, and the region S is a region in which the content of the filler is 5 to 50% by mass in the thickness direction of the film. Provided is an adhesive film for circuit connection, which comprises HF1 and in which the ratio of the width of the region HF1 to the width of the region S is 1 to 26.5%.

Another aspect of the present invention is an adhesive film for circuit connection containing conductive particles, in which the conductive particles are unevenly distributed on one side of the adhesive film, and the adhesive film is formed in the thickness direction of the film. A region S made of a thermosetting composition containing no conductive particles is included, and the region S is filled when the average content of the filler in the region S is Ms (% by mass) in the thickness direction of the film. Provided is an adhesive film for circuit connection, which comprises a region HF2 having a material content of 1.3 Ms mass% or more, and the ratio of the width of the region HF2 to the width of the region S is 1 to 26.5%.

According to the adhesive film for circuit connection on one side surface and the other side surface, it is possible to sufficiently secure the conduction between the facing electrodes of the circuit member, and the circuit has excellent peel resistance in a high temperature and high humidity environment. A connection structure can be obtained. The present inventors infer the reason why such an effect is obtained as follows. First, the region S, which is a thermosetting composition that does not contain conductive particles of the adhesive film for circuit connection, contains the region HF1 or the region HF2 that contains the filler at a high density in a specific range, thereby forming the conductive particles. It is considered that a cured product having a high elastic modulus and a large cohesive force could be formed while avoiding the inhibition of conduction with the electrodes of the circuit member. By including such a cured product having a large cohesive force in the circuit connection portion, the warp of the circuit member caused by long-term use in a high temperature and high humidity environment and the repulsive force of the conductive particles flattened at the time of mounting are exhibited. The present inventors presume that the peeling between the circuit member and the circuit connection portion that occurs due to this can be suppressed.

The circuit-connecting adhesive film on one side and the other side may include a region P containing light containing conductive particles and a photocurable product of a thermosetting resin composition in the thickness direction of the film. good. Further, the area S may be provided adjacent to the area P. In this case, the flow of conductive particles generated during the manufacture of the circuit connection structure can be further suppressed, and the connection resistance between the opposing electrodes can be easily reduced.

The width of the region S may be 5 to 200 μm.

Another aspect of the present invention comprises a first adhesive layer, a second adhesive layer, a third adhesive layer, and a second adhesive layer on top of the first adhesive layer. And a third adhesive layer are laminated in this order or vice versa, and the first adhesive layer contains a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, and conductive particles. The second adhesive layer is made of a heat-curable composition, and the third adhesive layer is made of a heat-curable composition containing a filler. Therefore, the content (% by mass) of the filler in the third adhesive layer is 5 to 50% by mass based on the total mass of the third adhesive layer, and the second adhesive layer and the third adhesive layer. Provided is an adhesive film for circuit connection, wherein the ratio of the thickness of the third adhesive layer to the total thickness of the adhesive layers is 1 to 26.5%.

Another aspect of the present invention comprises a first adhesive layer, a second adhesive layer, a third adhesive layer, and a second adhesive layer on top of the first adhesive layer. And a third adhesive layer are laminated in this order or vice versa, and the first adhesive layer contains a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, and conductive particles. The second adhesive layer is made of a heat-curable composition, and the third adhesive layer is made of a heat-curable composition containing a filler. The content of the filler in the third adhesive layer is 1.3 M when the average content of the filler in the second adhesive layer and the third adhesive layer is M (% by mass). (Mass%) or more, and the ratio of the thickness of the third adhesive layer to the total thickness of the second adhesive layer and the third adhesive layer is 1 to 26.5%, for circuit connection. An adhesive film is provided.

According to the adhesive film for circuit connection on the other side surface, the circuit connection structure can sufficiently secure the conduction between the facing electrodes of the circuit member and has excellent peeling resistance in a high temperature and high humidity environment. Can be obtained. The reason why such an effect is exhibited is that the third adhesive layer acts in the same manner as the above-mentioned region HF1 and region HF2, and the first adhesive layer is separated by the above-mentioned region P and the region P. It is conceivable that it acts in the same manner as the conductive particles formed.

The total thickness of the second adhesive layer and the third adhesive layer may be 5 to 200 μm.

Another aspect of the present invention is to interpose the above-mentioned circuit connection adhesive film between the first circuit member having the first electrode and the second circuit member having the second electrode. Provided is a method for manufacturing a circuit connection structure, comprising a step of thermally crimping a circuit member 1 and a second circuit member to electrically connect the first electrode and the second electrode to each other.

According to the method for manufacturing a circuit connection structure on another side thereof, it is possible to obtain a circuit connection structure having sufficiently small connection resistance between opposing electrodes and having excellent peeling resistance in a high temperature and high humidity environment. can.

Another aspect of the invention is disposed between a first circuit member having a first electrode, a second circuit member having a second electrode, and a first circuit member and a second circuit member. Provided is a circuit connection structure comprising a circuit connection portion for electrically connecting a first electrode and a second electrode to each other, wherein the circuit connection portion contains a cured product of the above-mentioned circuit connection adhesive film. ..

In the circuit connection structure on the other side thereof, the connection resistance between the opposing electrodes is sufficiently small, and even when the circuit connection structure is used for a long period of time in a high temperature and high humidity environment, it is between the circuit connection portion and the circuit member. It is difficult for peeling to occur, and the connection reliability can be excellent.

According to the present invention, it is possible to sufficiently secure the continuity between the facing electrodes of the circuit member, and to obtain a circuit connection structure having excellent peeling resistance in a high temperature and high humidity environment. It is possible to provide an agent film, a circuit connection structure using the adhesive film, and a method for producing the same.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection. FIG. 2 is a schematic cross-sectional view showing an embodiment of a circuit connection structure. FIG. 3 is a schematic cross-sectional view showing a manufacturing process according to an embodiment of a method for manufacturing a circuit connection structure. FIG. 4 is a schematic cross-sectional view showing a manufacturing process according to an embodiment of a method for manufacturing a circuit connection structure. FIG. 5 is a schematic cross-sectional view showing a manufacturing process according to another embodiment of the method for manufacturing a circuit connection structure. FIG. 6 is a schematic cross-sectional view showing a manufacturing process according to another embodiment of the method for manufacturing a circuit connection structure.

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 the numerical range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical range of one step may be replaced with the upper limit value or the lower limit value of the numerical range of another step. Further, in the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In addition, the upper limit value and the lower limit value described individually can be arbitrarily combined. Further, as used herein, the term "(meth) acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth) acryloyl". Further, "(poly)" means both with and without the prefix of "poly". Further, "A or B" may include either A or B, and may include both. Further, unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. The content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as the case may be. However, the present invention is not limited to the following embodiments.

<Adhesive film for circuit connection>
The circuit connection adhesive film of the present embodiment includes a first adhesive layer, a second adhesive layer, and a third adhesive layer, and a second adhesive layer is placed on the first adhesive layer. The adhesive layer and the third adhesive layer are laminated in this order or vice versa.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection according to the present embodiment. The circuit connection adhesive film 1a (hereinafter, also simply referred to as “adhesive film 1a”) shown in FIG. 1 (a) is laminated on the first adhesive layer 2 and the first adhesive layer 2. The second adhesive layer 3 is provided, and the third adhesive layer 6 laminated on the second adhesive layer 2 is provided. The circuit connection adhesive film 1b (hereinafter, also simply referred to as “adhesive film 1b”) shown in FIG. 1 (b) is laminated on the first adhesive layer 2 and the first adhesive layer 2. The third adhesive layer 6 is provided, and the second adhesive layer 3 laminated on the third adhesive layer 6 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 “(C) component”) and (D) conductive particles 4 (hereinafter, also referred to as “(D) component”).

In the first adhesive layer 2, for example, the component (A) is polymerized by irradiating a layer made 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 the conductive particles 4 and the adhesive component 5 obtained by curing components other than the conductive particles 4 of the light and thermosetting composition. The adhesive component 5 contains at least the polymer of the component (A) and the component (C). The adhesive component 5 may or may not contain the unreacted components (A) and (B).

[(A) component: polymerizable compound]
The component (A) is, for example, a compound polymerized by a radical, a cation or an anion 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 may be a radically polymerizable group that reacts with a radical from the viewpoint that the effect of reducing the connection resistance is further improved and the connection reliability is more excellent. That is, the component (A) may be 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 necessary for reducing the connection resistance and the cross-linking 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. 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, tetrahydrofurfuryl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, N, N- Dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylol propanetri (meth) acrylate, tetramethylol methanetetra (meth) acrylate, polyethylene glycol di. (Meta) acrylate, polyalkylene glycol di (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol (Meta) 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- (meth) a Examples thereof include cryloyloxyethyl acid phosphate and the like.

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-diphenylether 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'-cyclohexili Examples thereof include den-bis (1- (4 maleimide phenoxy) -2-cyclohexyl) benzene, 2,2'-bis (4- (4-maleimide phenoxy) phenyl) hexafluoropropane and the like.

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. It's okay. Further, the component (A) may be a (meth) acrylate compound having a high Tg skeleton such as a tricyclodecane 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, may be 5000 or more, and may be 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. The weight average molecular weight is a value measured by a gel permeation chromatograph (GPC) using a calibration curve made of 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 general 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).

式（１）中、ｎは１～３の整数を示し、Ｒは、水素原子又はメチル基を示す。 The component (A) may contain a (meth) acrylate compound represented by the following formula (1) (a (meth) acrylate compound having a phosphoric acid ester structure). 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 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 (meth) acrylate compound represented by the formula (1) further improves the adhesive force to the surface of the inorganic substance (metal or the like), and further improves the adhesive strength between the electrodes (for example, between the circuit electrodes). For example, it may be 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more, based on the total mass of the component (A), and may be 20% by mass or less, 10% by mass or less, or 5% by mass. It may be 0.1 to 20% by mass, 0.5 to 10% by mass, or 1 to 5% by mass.

The content of the component (A) is other than, for example, conductive particles in the light and thermosetting composition from the viewpoint that the crosslink density required for further reducing the connection resistance and further improving the connection reliability can be easily obtained. It may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more based on the total amount of the components of. The content of the component (A) is 90% by mass or less and 80% by mass based on the total amount of the components other than the conductive particles in the light and the thermosetting composition, for example, from the viewpoint of suppressing the curing shrinkage during polymerization. Hereinafter, it may be 70% by mass or less or 60% by mass. From these viewpoints, the content of the component (A) is, for example, 5 to 90% by mass, 10 to 80% by mass, 20 based on the total amount of the components other than the conductive particles in the light and the thermosetting composition. It may be ~ 70% by mass, 30-60% by mass or 40-60% 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 (photoradical polymerization initiator, photocationic polymerization initiator or photoanionic polymerization initiator) that generates a cation or anion. The component (B) is preferably a photoradical polymerization initiator from the viewpoint of facilitating curing at a low temperature in 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, when a photopolymerization initiator having an oxime ester structure is used, the effect of suppressing the flow of conductive particles and the effect of suppressing peeling tend to be further improved.

式（ＶＩ）中、Ｒ^１１、Ｒ^１２及びＲ^１３は、それぞれ独立して、水素原子、炭素数１～２０のアルキル基、又は芳香族系炭化水素基を含む有機基を示す。 Among the compounds having an oxime ester structure, a compound having a structure represented by the following formula (VI) can be used because the above effects can be easily obtained.

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-diphenylpropantrione- 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.

Compounds 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. 2,4,5-Triarylimidazole dimer can be mentioned.

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. May be 0.1% by mass or more, 0.3% by mass or more, 0.45% by mass or more, 0.55% by mass or more, or 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 may be 1.2% by mass or less, 0.9% by mass or less, or 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 0.1 to 0.1 based on the total amount of the components other than the conductive particles in the light and the thermosetting composition. It may be 1.2% by mass, 0.3 to 1.2% by mass, 0.45 to 0.9% by mass, or 0.45 to 0.6% by 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. It may be 0.3% by mass or more, 0.45% by mass or more, 0.55% by mass or more, or 0.85% by mass or more. The content of the component (B) is 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. It may be 9% by mass or less or 0.6% by mass or less. From these viewpoints, the content of the component (B) is 0.3 to 1.2% by mass and 0.45 to 0 based on the total amount of the components other than the conductive particles in the light and the thermosetting composition. It may be 9.9% by mass or 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 anionic 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. The thermal radical polymerization initiator may be an organic peroxide from the viewpoint of further improving the flow suppressing effect of the conductive particles and the peeling suppressing effect, and may be an organic peroxide from the viewpoint of stability, reactivity and compatibility. It may be an organic peroxide having a minute half-life temperature of 90 to 175 ° C. and a weight average molecular weight of 180 to 1000. When the 1-minute half-life temperature of the organic peroxide is in the above range, the storage stability tends to be further excellent, and a sufficiently high radical polymerizable property can be obtained, so that the organic peroxide can be cured 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-hexylperoxyisopropyl 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), etc. Azo compounds and the like can be mentioned.

The content of the component (C) is other than the conductive particles in the light and thermosetting composition from the viewpoint of excellent quick-curing property, flow suppressing effect of conductive particles, and further improvement of peeling suppressing effect. Based on the total amount of the components of, 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) may be 20% by mass or less, and 10% 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 pot life. It may be 5% by mass or less.

[(D) component: conductive particles]
The component (D) is not particularly limited as long as it is conductive particles, such as metal particles made of metal such as Au, Ag, Ni, Cu, and solder, and conductive carbon particles made of conductive carbon. 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 covering the nucleus. good. Among these, when metal particles formed of a thermosetting metal or a core containing a plastic and a coated conductive particle containing a metal or a conductive carbon and having a coating layer covering the core are used, light and heat are used. It becomes easy to deform the cured product of the curable composition by heating or pressurizing. Therefore, when the electrodes are electrically connected to each other, the contact area between the electrodes and the component (D) can be increased, and the conductivity between the electrodes can be further improved.

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 having an insulating layer covering the surface of the particles. good. 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 the resin, so that the component (D) is short-circuited due to contact with each other. The generation can be suppressed, and the insulation between adjacent electrode circuits can be improved. As the component (D), one of the above-mentioned various conductive particles 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 any 300 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 any 300 conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the average value of the obtained particle sizes is taken as the average particle size.

In the first adhesive layer 2, the component (D) is preferably uniformly dispersed. The particle density of the component (D) in the first adhesive layer 2 may be 100 pcs / mm ^{2 or more, 1000 pcs / mm 2 or} more, and 2000 pcs / mm from the viewpoint that stable connection resistance can be easily obtained. It may be mm ² or more. The particle density of the component (D) in the first adhesive layer 2 may be 100,000 pcs / mm ² or less, and may be 50,000 pcs / mm ² or less, from the viewpoint of improving the insulating property between adjacent electrodes. It may be 10000 pcs / mm ² or less.

In the first adhesive layer 2, 70% or more or 90% or more of the conductive particles may be in a state of being separated from other conductive particles. The ratio (monodispersion ratio) in which the conductive particles exist in a state of being separated from other adjacent conductive particles (monodispersion rate) is 200 times the state of the conductive particles in the adhesive layer using a metallurgical microscope. It can be obtained by observing with a magnification and using the following formula.
Single dispersion rate (%) = (number of conductive particles in a monodisperse state in 0.16 mm ² / number of conductive particles in 0.16 mm ² ) × 100

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 may be 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%. The content of the component (D) based on the total product of the light and the thermosetting composition or the cured product thereof may be the same as the above range.

The content of the component (D) is, for example, 5% by mass or more, 15% by mass or more, or 20% by mass or more based on the total mass of the first adhesive layer from the viewpoint of further improving the conductivity. It may be there. The content of the component (D) may be, for example, 80% by mass or less, 70% by mass or less, or 60% by mass or less based on the total mass of the first adhesive layer from the viewpoint of easily suppressing a short circuit. From these viewpoints, the content of the component (D) may be, for example, 5 to 80% by mass, 10 to 70% by mass, or 20 to 60% by mass based on the total mass of the first adhesive layer. The content of the component (D) based on the total mass of the light and the thermosetting composition or the cured product thereof 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). Examples of other components include thermoplastic resins, coupling agents, fillers and the like. 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 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 may be 20% by mass or less, based on the total amount of components other than the conductive particles in the light and the thermosetting composition. .. In addition, in this specification, a silane coupling agent having a polymerizable group such as a (meth) acryloyl group is not included in the polymerizable compound.

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 content of the filler may be, for example, 0 to 50% by mass, or 1 to 10% by mass, based on the total amount of components other than the conductive particles in the light and the thermosetting composition. good.

The light and thermosetting composition may contain other additives such as softeners, accelerators, antioxidants, 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 content of each of the above-mentioned components based on the total mass of the components other than the conductive particles in the first adhesive layer is the total amount of the components other than the conductive particles in the above-mentioned light and thermosetting composition. It may be the same as the standard content range.

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 facing electrodes and the connection resistance can be further reduced. It may be present, 0.2 times or more, and may be 0.3 times or more. The thickness d1 of the first adhesive layer 2 makes it easier for the conductive particles to collapse when the conductive particles are sandwiched between the facing electrodes during thermocompression bonding, and the conductive particles 4 can further reduce the connection resistance. The average particle size of the particles may be 0.8 times or less, and may be 0.7 times or less. 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. 1A, the first adhesive layer 2 A part of the conductive particles 4 inside 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. 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. Similarly, in the case of the circuit connection adhesive film 1b shown in FIG. 1 (b), a part of the conductive particles 4 in the first adhesive layer 2 is formed from the first adhesive layer 2 to the third. May protrude toward the adhesive layer 6 side of the above. In this case, the boundary S between the first adhesive layer 2 and the third adhesive layer 6 is located at the separated portion of the adjacent conductive particles 4 and 4. The conductive particles 4 may not be exposed on the surface 2b of the first adhesive layer 2 on the side opposite to the third adhesive layer 6 side, and the surface 2b on the opposite side may be a flat surface. Due to the presence of the boundary S on the conductive particles along the surface of the conductive particles, the conductive particles P in the first adhesive layer 2 move from the first adhesive layer 2 to the second adhesive layer 3 side. The above relationship may be satisfied without protruding.

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, and may be 20 μm or less. When a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 2 (for example, protruding toward the second adhesive layer 3 or the third adhesive layer 6), the first A first adhesive located at a distance between adjacent conductive particles 4 and 4 from the surfaces 2a and 2b of the adhesive layer 2 opposite to the second adhesive layer 3 or the third adhesive layer 6 side. The distance between the layer 2 and the boundary S between the second adhesive layer 3 or the third adhesive layer 6 (distance indicated by d1 in FIGS. 1A and 1B) is the first adhesive layer 2. The exposed portion of the conductive particles 4 is not included in the thickness of the first adhesive layer 2. The length of the exposed portion of the conductive particles 4 may be, for example, 0.1 μm or more, and may be 20 μm or less.

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 Corporation) 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 (a)) and (b) a thermal polymerization initiator (hereinafter, also referred to as a component (b)). It comprises a first thermosetting composition. The first 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.

[(A) component: polymerizable compound]
The component (a) is, for example, a compound polymerized by a radical, a cation or an anion 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 in a short time, further improving the effect of reducing connection resistance, and improving connection reliability. May be. Examples of the radically polymerizable compound and its combination are the same as those of the component (A).

(A) The component may be any of a monomer, an oligomer or a polymer. (A) As a component, 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, for example, 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.

[Component (b): Thermal polymerization initiator]
As the component (b), the same thermal polymerization initiator as the component (C) can be used. (B) As a component, one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination. The component (b) may be a thermal radical polymerization initiator, and the example of the thermal radical polymerization initiator in the component (b) is the same as that of 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. It's okay. From these viewpoints, the content of the component (b) is, for example, 0.1 to 30% by mass, 0.5 to 20% by mass, or 1 to 10% by mass based on the total mass of the thermosetting composition. It's okay.

[Other ingredients]
The thermosetting composition may further contain other components other than the component (a) and 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 a 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 to cure the thermosetting resin.

The thermosetting resin is a resin that cures by heat and has at least one thermosetting group. The 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 novolak 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 curing agent is not particularly limited as long as it is a curing agent that generates cation species by heat, and can be appropriately selected depending on the intended purpose. Examples of the curing agent include sulfonium salts and iodonium salts.

When a thermosetting resin is used in place 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 80% by mass or more, and may be 80% by mass or less. When a thermosetting resin is used in addition to 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 80% by mass or more, and may be 80% by mass or less. The content of the curing agent may be, for example, 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the thermosetting resin.

When the thermosetting composition contains a filler, the content thereof can be set so as to satisfy a predetermined condition described later in relation to the content of the filler in the third adhesive layer, for example. Based on the total mass of the thermosetting composition (including the filler), it may be 40% by mass or less, 20% by mass or less, 10% by mass or less, and 0.1. It may be up to 20% by mass, or may be 1 to 10% by mass.

The content of the conductive particles in the second adhesive layer 3 may be, for example, 1% by mass or less based on the total mass of the second adhesive layer. The second adhesive layer 3 does not have to contain conductive particles. When the second adhesive layer 3 contains conductive particles, the content based on the total amount of the components other than the conductive particles in the thermosetting composition of each component described above is the thermosetting composition described above. It may be the same as the range of content based on the total mass of the substance.

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. 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 (a) of FIG. 1) is the thickness of the second adhesive layer 3. Further, in the case of the circuit connection adhesive film 1b shown in FIG. 1 (b), the second adhesive layer 3 is formed from the boundary 6b with the third adhesive layer 6 in the second adhesive layer 3. The distance to the surface 3b on the side opposite to the adhesive layer 6 side of No. 3 (distance indicated by d2 in (b) of 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 second adhesive layer can be obtained, for example, by the same method as the method for measuring the thickness d1 of the first adhesive layer 2.

(Third adhesive layer)
The third adhesive layer 6 is, for example, (P) polymerizable compound (hereinafter, also referred to as (P) component), (Q) thermal polymerization initiator (hereinafter, also referred to as (Q) component) and (G). ) The second thermosetting composition containing a filler (hereinafter, also referred to as a component (G)). The second thermosetting composition constituting the third adhesive layer 6 is a thermosetting composition that can flow when connected to a circuit, and is, for example, an uncured thermosetting composition.

[(P) component: polymerizable compound]
The component (P) is, for example, a compound polymerized by a radical, a cation or an anion generated by a thermal polymerization initiator by heat. As the component (P), the compound exemplified as the component (A) can be used. The component (P) is a radically polymerizable compound having a radically polymerizable group that reacts with radicals from the viewpoint of facilitating connection at low temperature in a short time, further improving the effect of reducing connection resistance, and improving connection reliability. It's okay. Examples of the radically polymerizable compound and its combination are the same as those of the component (A).

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

The content of the component (P) 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 (P) 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 (P) may be, for example, 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.

[(Q) component: thermal polymerization initiator]
As the component (Q), the same thermal polymerization initiator as the component (C) can be used. As the component (Q), one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination. The component (Q) may be a thermal radical polymerization initiator, and examples of the thermal radical polymerization initiator are the same as those of the component (C).

The content of the component (Q) 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 (Q) 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. It's okay. From these viewpoints, the content of the component (Q) is, for example, 0.1 to 30% by mass, 0.5 to 20% by mass, or 1 to 10% by mass based on the total mass of the thermosetting composition. It's okay.

[(G) component: filler]
As the component (G), the same filler as those exemplified in the description of the first adhesive layer can be used.

The content of the component (G) may be 5% by mass or more, and 10% by mass or more, based on the total mass of the thermosetting composition (including the filler) from the viewpoint of obtaining the effect of suppressing peeling. It may be present, and may be 15% by mass or more. Further, the content of the component (G) is based on the total mass of the thermosetting composition (including the filler) from the viewpoint of suppressing an increase in the connection resistance due to the inhibition of conduction between the opposing electrodes by the filler. It may be 50% by mass or less, 30% by mass or less, and 25% by mass or less. From these viewpoints, the content of the component (G) may be 5% by mass to 50% by mass, based on the total mass of the thermosetting composition (including the filler), and may be 10% by mass to 30% by mass. It may be 15% by mass to 25% by mass.

Further, the content (% by mass) of the component (G) is the average of the fillers in the second adhesive layer and the third adhesive layer, which is calculated by the following formula from the viewpoint of obtaining the effect of suppressing peeling. When the content is M (mass%), it may be 1.1 M% by mass or more, 1.2 M% by mass or more, or 1.3 M% by mass or more. It may be .4 M% by mass or more, 1.5 M% by mass or more, 2.0 M% by mass or more, or 2.5 M% by mass or more. Further, the content (% by mass) of the component (G) may be 40 M% by mass or less, and may be 30 M% by mass, from the viewpoint of suppressing an increase in the connection resistance due to the inhibition of conduction between the opposing electrodes by the filler. It may be less than or equal to, 20 M% by mass or less, 15 M% by mass or less, 10 M% by mass or less, or 5 M% by mass or less. From these viewpoints, the content (% by mass) of the component (G) may be 1.1 M to 40 M mass%, 1.5 M to 20 M mass%, or 1.5 M to 10 M mass. May be%.
M (mass%) = [(M2 × d2) + (M3 × d3)] / (d2 + d3)
[In the formula, M2 indicates the content (% by mass) of the filler in the second adhesive layer, d2 indicates the thickness (μm) of the second adhesive layer, and M3 indicates the third adhesive layer. The content (% by mass) of the filler in the adhesive layer is shown, and d3 is the thickness (μm) of the third adhesive layer].

The average content M (mass%) of the filler in the second adhesive layer and the third adhesive layer may be 1.0% by mass or more from the viewpoint of obtaining the effect of suppressing peeling. It may be 5% by mass or more by mass% or more. Further, the average content M (mass%) of the filler in the second adhesive layer and the third adhesive layer is from the viewpoint of suppressing an increase in connection resistance due to the inhibition of conduction between the opposing electrodes by the filler. , 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less. , 7.5% by mass or less. From these viewpoints, the average content M (mass%) of the filler in the second adhesive layer and the third adhesive layer may be 1.0 to 40% by mass, or 3 to 20% by mass. It may be 3 to 11% by mass.

[Other ingredients]
The thermosetting composition may further contain other components other than the component (P), the component (Q) and the component (G). Examples of other components include thermoplastic resins, coupling agents, 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 (P) and (Q), or in addition to the components (P) and (Q). In this case, the thermosetting composition may contain a curing agent used for curing the above-mentioned thermosetting resin. When a thermosetting resin is used in place of the component (P) and the component (Q), 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 80% by mass or more, and may be 80% by mass or less. When a thermosetting resin is used in addition to the component (P) and the component (Q), 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 80% by mass or more, and may be 80% by mass or less. The content of the curing agent may be, for example, 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the thermosetting resin.

The content of the conductive particles in the third adhesive layer 6 may be, for example, 1% by mass or less based on the total mass of the third adhesive layer. The second adhesive layer 3 does not have to contain conductive particles. When the third adhesive layer 6 contains conductive particles, the content based on the total amount of the components other than the conductive particles in the thermosetting composition of each component described above is the thermosetting composition described above. It may be the same as the range of content based on the total mass of the substance.

The thickness d3 of the third adhesive layer 6 is 1% or more as a ratio to the total thickness (d2 + d3) of the second adhesive layer and the third adhesive layer from the viewpoint of obtaining the effect of suppressing peeling. It may be 5% or more. Further, from the viewpoint of suppressing the increase in connection resistance due to the inhibition of conduction by the filler, d3 may be 36% or less, and may be 24% or less, as a ratio to (d2 + d3). From these viewpoints, d3 may be 1% to 36% and may be 5% to 24% as a ratio to (d2 + d3). The thickness of the third adhesive layer can be obtained, for example, by the same method as the method for measuring the thickness d1 of the first adhesive layer 2.

The total thickness (d2 + d3) of the second adhesive layer and the third adhesive layer is from the viewpoint of enhancing the adhesive force between the connected circuits by sufficiently filling the inside of the mounted circuit with the adhesive film. It may be 5 to 200 μm, 6 to 25 μm, or 7.5 to 14 μm.

The thickness d3 of the third adhesive layer 6 may be 0.085 to 72 μm, and may be 0, from the viewpoint of obtaining the effect of suppressing peeling while suppressing the increase in connection resistance due to the inhibition of conduction by the filler. .1 to 72 μm, 0.4 to 3 μm, 0.4 to 2 μm.

Thickness of Adhesive Films 1a and 1b (Total thickness of all layers constituting the adhesive films 1a and 1b. In FIGS. 1A and 1B, the thickness of the first adhesive layer 2 The sum of the d1 and the thickness d2 of the second adhesive layer 3 and the thickness d3 of the third adhesive layer 6) may be, for example, 5 μm or more, and may be 200 μm or less.

In the adhesive films 1a and 1b, the conductive particles 4 are dispersed in the first adhesive layer 2. Therefore, the adhesive films 1a and 1b are anisotropically conductive adhesive films having anisotropic conductivity. The adhesive films 1a and 1b are interposed between the first circuit member having the first electrode and the second circuit member having the second electrode, and the first circuit member and the second circuit member are interposed. Is thermally crimped and used to electrically connect the first electrode and the second electrode to each other.

According to the adhesive films 1a and 1b, the flow of conductive particles generated during the manufacture of the circuit connection structure can be suppressed. Further, according to the adhesive films 1a and 1b, it is possible to sufficiently secure the conduction between the facing electrodes of the circuit member, and to obtain a circuit connection structure having excellent peeling resistance in a high temperature and high humidity environment. Can be done.

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

The circuit connection adhesive film of the present embodiment has a structure in which the third adhesive layer is laminated on one of the second adhesive layers, but is laminated on both sides of the second adhesive layer. The second adhesive layer may be divided and laminated in between.

In the former case (third adhesive layer A / second adhesive layer / third adhesive layer B), the content of the filler in the third adhesive layer A and the third adhesive layer B and The thickness of the layer can be set in the same manner as in the third adhesive layer described above. For example, the content of the filler in each of the third adhesive layer A and the third adhesive layer B is determined in the second adhesive layer, the third adhesive layer A, and the third adhesive layer B. When the average content of the filler is Ma (mass%) (Ma is calculated in the same manner as M described above), it can be 1.5 Ma or more, and can be the same as the above range. The total thickness of the third adhesive layer A and the third adhesive layer B is the thickness of the second adhesive layer, the third adhesive layer A, and the third adhesive layer B. It can be 1 to 26.5% of the total, and can be the same as the above range.

In the latter case (second adhesive layer A / third adhesive layer / second adhesive layer B), the content of the filler in the second adhesive layer A and the second adhesive layer B and The thickness of the layer can be set in the same manner as in the second adhesive layer described above. For example, the content of the filler in the third adhesive layer is Mb (mass%) of the average content of the filler in the second adhesive layer A, the second adhesive layer B, and the third adhesive layer. ) (Mb is calculated in the same manner as M described above), it can be 1.5 Mb or more, can be the same as the above range, and the thickness of the third adhesive layer can be increased. , 1 to 26.5% with respect to the total thickness of the second adhesive layer A, the second adhesive layer B and the third adhesive layer, and the same as the above range. be able to.

Further, the circuit connection adhesive film has a fourth adhesive layer on a surface of the first adhesive layer opposite to the side on which the second adhesive and the third adhesive layer are provided. May be further prepared. In this case, the fourth adhesive layer may be made of, for example, a thermosetting composition like the second adhesive layer and the third adhesive layer.

The thickness of the fourth adhesive layer may be appropriately set according to the minimum melt viscosity of the adhesive film, the height of the electrodes of the circuit members to be adhered, and the like. The thickness of the fourth adhesive layer is preferably smaller than the thickness d2 of the second adhesive layer 3. The thickness of the fourth adhesive layer may be 0.2 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. , 3.0 μm or less. The thickness of the fourth adhesive layer can be obtained, for example, by the same method as the method for measuring the thickness d1 of the first adhesive layer 2.

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 does not have anisotropic conductivity. It may be an adhesive film.

Another embodiment of the circuit connection adhesive film is a circuit connection adhesive film containing conductive particles, wherein the conductive particles are unevenly distributed on one side of the adhesive film and are thermally curable without containing the conductive particles. It may include a region S composed of a composition.

The region S includes the region HF1 in which the content of the filler is 5 to 50% by mass in the thickness direction of the film, and the ratio of the width of the region HF1 to the width of the region S is 1 to 26.5%. , Region HF1 can be contained. The ratio of the width of the region HF1 to the width of the region S may be 1 to 26.5%, 4.8 to 19.4%, or 10.5 to 15%. .. The content of the filler in the region HF1 may be 10 to 30% by mass, or 15 to 25% by mass. According to the adhesive film having such conditions, it is possible to sufficiently secure the conduction between the facing electrodes of the circuit member, and obtain a circuit connection structure having excellent peeling resistance in a high temperature and high humidity environment. Will be easy.

The region S contains the region HF2 in which the content of the filler is 1.5 Ms mass% or more when the average content of the filler in the region S is Ms (mass%) in the thickness direction of the film. be able to. Ms in this case is calculated by the following formula. The ratio of the width of the region HF2 to the width of the region S may be 1 to 26.5%, 4.8 to 19.4%, or 10.5 to 15%. .. The content of the filler in the region HF2 may be 1.1 Ms mass% or more, 1.2 Ms mass% or more, or 1.3 Ms mass% or more from the viewpoint of obtaining the effect of suppressing peeling. It may be 1.4 Ms mass% or more, 1.5 Ms mass% or more, 2.0 Ms mass% or more, 2.5 Ms mass% or more. You may. Further, the content of the filler in the region HF2 may be 40 Ms mass% or less, or 30 Ms mass% or less, from the viewpoint of suppressing an increase in the connection resistance due to the inhibition of conduction between the opposing electrodes by the filler. It may be 20 Ms mass% or less, 15 Ms mass% or less, 10 Ms mass% or less, or 5 Ms mass% or less. According to the adhesive film having such conditions, it is possible to sufficiently secure the conduction between the facing electrodes of the circuit member, and obtain a circuit connection structure having excellent peeling resistance in a high temperature and high humidity environment. Will be easy.
Ms (% by mass) = [(M _LF x d _LF ) + (M _HF2 x d _HF2 )] / (d _LF + d _HF2 )
[In the formula, MLF indicates the content (% by mass) of the filler in the region excluding the region _HF2 in the region S, and _dLF indicates the region HF2 in the region S in the thickness direction of the film. The excluded width (μm) is shown, _MHF2 shows the content (% by mass) of the filler in the region HF2, and _dHF2 shows the width (μm) of the region HF2 in the thickness direction of the film. ]

The average content Ms (% by mass) of the filler in the region S may be 1.0% by mass or more, 3% by mass or more, or 5% by mass from the viewpoint of obtaining the effect of suppressing peeling. It may be% or more. Further, the average content Ms of the filler in the region S may be 40% by mass or less, and may be 30% by mass or less, from the viewpoint of suppressing an increase in the connection resistance due to the inhibition of conduction between the opposing electrodes by the filler. It may be 20% by mass or less, 15% by mass or less, 11% by mass or less, 10% by mass or less, and 7.5% by mass. It may be less than or equal to%. From these viewpoints, the average content Ms of the filler in the region S may be 1 to 40% by mass, 3 to 20% by mass, or 3 to 11% by mass.

The content of the filler in the region HF2 may be 5 to 50% by mass, 10% by mass to 30% by mass, or 15% by mass to 25% by mass.

The circuit connection adhesive film according to another embodiment may include a region P containing light containing conductive particles and a photocurable product of a thermosetting resin composition in the thickness direction of the film. Further, the area S may be provided adjacent to the area P. In this case, the flow of conductive particles generated during the manufacture of the circuit connection structure can be further suppressed, and the connection resistance between the opposing electrodes can be easily reduced.

The circuit connection adhesive film according to another embodiment may have the same configuration as the adhesive films 1a and 1b described above. For example, the second adhesive layer and the third adhesive layer in the adhesive films 1a and 1b may be the above-mentioned region S, and the third adhesive layer may be the above-mentioned region HF1 or region HF2. In this case, the width of the region S in the thickness direction of the film can be the same as the sum of the thickness d2 of the second adhesive layer and the thickness d3 of the third adhesive layer described above, and the region HF can be formed. The width of the film in the thickness direction can be the same as the thickness d3 of the third adhesive layer described above.

Further, the first adhesive layer in the adhesive films 1a and 1b may be the region P. In this case, the width of the region P in the thickness direction of the film can be the same as the thickness d1 of the first adhesive layer 2 described above. The monodispersity of the conductive particles can be the same as the range in the first adhesive layer described above. The width of the region P in the thickness direction of the film is defined as the width from one end (end point on the substrate side of the region P) (for example, the boundary with the substrate) of the region P in the thickness direction of the film to the other end (region P). It means the distance to the end point on the side opposite to the base material side (for example, the boundary with the region S). The positions of these ends are between the adjacent conductive particles and the conductive particles.

<Manufacturing method of adhesive film for circuit connection>
The method for manufacturing the circuit connection adhesive films 1a and 1b of the present embodiment is, for example, a preparation step (first preparation step) for preparing the first adhesive layer 2 described above and a first adhesive layer 2. The above-mentioned laminating step of laminating the second adhesive layer 3 and the third adhesive layer 6 described above is provided. The method for manufacturing the adhesive films 1a and 1b for circuit connection is a preparation step for preparing the second adhesive layer 3 (second preparation step) and a preparation step for preparing the third adhesive layer 6 (third preparation step). The preparation process) may be further provided. The order in which the first preparation step and the second preparation step are performed is not limited, and the first preparation step may be performed first, or the second preparation step may be performed first. The order in which the second adhesive layer 3 and the third adhesive layer 6 are laminated may be such that the second adhesive layer 3 may come first, or the third adhesive layer 6 may come first. .. Further, the method for manufacturing the adhesive films 1a and 1b for circuit connection includes a preparation step (fourth preparation step) for preparing a laminate of the second adhesive layer 3 and the third adhesive layer 6. The laminating step may be a step of laminating the laminated body on the first adhesive layer 2.

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 solvent (organic solvent). A varnish composition (varnish-like light and thermosetting composition) is prepared by dissolving or dispersing by stirring and mixing, kneading, or the like. Then, the varnish composition is applied onto the demolding-treated substrate using a knife coater, a roll coater, an applicator, a comma coater, a die coater, etc., and then the solvent is volatilized by heating to form the substrate on 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 substrate. Form (curing step). As a result, the first adhesive film is obtained.

As the solvent used for preparing the varnish composition, a solvent having a property of uniformly dissolving or dispersing each component may be used. Examples of such a solvent include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate and the like. These 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 raider, a three-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 solvent is volatilized. For example, stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, and polyethylene isophthalate are used. , Polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene / vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer, etc. Film) can be used.

The heating conditions for volatilizing the solvent from the varnish composition applied to the substrate may be conditions under which the solvent is sufficiently volatilized. 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.

A part of the solvent may remain in the layer composed of the light and the thermosetting composition without being removed. The content of the solvent in the layer composed of the light and the thermosetting composition may be, for example, 10% by mass or less based on the total mass of the layer composed of the light and the thermosetting composition.

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 irradiation amount of light may be, for example, the integrated light amount of light having a wavelength of 365 nm, which may be 10000 mJ / cm ² or less, 5000 mJ / cm ² or less, or 3000 mJ / cm ² or less.

In the second preparation step, a second varnish composition (varnish-like first thermosetting composition) containing the component (a) and the component (b) and other components added as needed is prepared. A second adhesive film is obtained by forming the second adhesive layer 3 on the substrate, as in the first preparation step, except that it is used and not irradiated with light. The adhesive layer 3 is prepared.

A part of the solvent may remain in the second adhesive layer 3 without being removed. The content of the solvent in the second adhesive layer 3 may be, for example, 10% by mass or less based on the total mass of the second adhesive layer 3.

In the third preparation step, a third varnish composition (varnish-like second thermosetting) containing (P) component, (Q) component and (G) component, and other components added as needed. A third adhesive film is obtained by forming a third adhesive layer 6 on the substrate in the same manner as in the first preparation step, except that the sex composition) is used and light irradiation is not performed. To prepare a third adhesive layer 6.

A part of the solvent may remain in the third adhesive layer 6 without being removed. The content of the solvent in the third adhesive layer 6 may be, for example, 10% by mass or less based on the total mass of the third adhesive layer 6.

In the laminating step, the second adhesive film and the third adhesive film are bonded to the first adhesive film in this order or vice versa, so that the second adhesive film is adhered onto the first adhesive layer 2. The agent layer 3 and the third adhesive layer 6 may be laminated, and one of the second varnish composition and the third varnish composition is applied onto the first adhesive layer 2 to apply a solvent. After volatilizing, the other may be coated on the other to volatilize the solvent, whereby the second adhesive layer 3 and the third adhesive layer 6 may be laminated on the first adhesive layer 2. ..

In the fourth preparation step, the second adhesive film and the third adhesive film obtained in the same manner as in the second preparation step and the third preparation step described above are bonded to each other to form a second adhesive. A laminate of the agent layer 3 and the third adhesive layer 6 may be prepared, and one of the second varnish composition and the third varnish composition is applied onto the substrate to volatilize the solvent. After that, the other may be applied on top of this to volatilize the solvent to form a laminate of the second adhesive layer 3 and the third adhesive layer 6.

Examples of the method of adhering the adhesive films to each other include a method of heat pressing, roll laminating, vacuum laminating and the like. 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 1a 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 a 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. It is arranged between 16 and includes a circuit connection portion 17 that electrically connects the first electrode 12 and the second electrode 15 to each other.

The first circuit member 13 and the second circuit member 16 may be the same as or different from each other. The first circuit member 13 and the second circuit member 16 may be a glass substrate or a plastic substrate on which electrodes are formed, a printed wiring board, a ceramic wiring board, a flexible wiring board, a semiconductor silicon IC chip, 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 oxidation. 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 described above. The circuit connection portion 17 is located, for example, on the side of the first circuit member 13 in the direction in which the first circuit member 13 and the second circuit member 16 face each other (hereinafter referred to as “opposite direction”), and the above-mentioned light 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 heat-curable composition and the second circuit member 16 in the facing direction, and is made of the cured product of the above-mentioned heat-curable 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 1a is interposed, the first circuit member 13 and the second circuit member 16 are thermally pressure-bonded, and the first electrode 12 and the second electrode 15 are electrically connected to each other. To prepare for.

Specifically, as shown in FIG. 3A, first, a first circuit including a first electrode 12 formed on a main surface 11a of a first circuit board 11 and a first circuit board 11. A member 13 and a second circuit member 16 provided with 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 1a is arranged between the circuit member 16 and the circuit member 16. For example, as shown in FIG. 3A, the adhesive film 1a 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. do. Next, the adhesive film 1a 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, the adhesive film 1, and the second circuit member 16 are heated while the first circuit member 13 and the second circuit member 16 are heated. 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.

The temperature and time at the time of thermocompression bonding may be any temperature as long as the adhesive film 1a can be sufficiently cured and the first circuit member 13 and the second circuit member 16 can be adhered to each other. The thermocompression bonding temperature may be, for example, 50 to 90 ° C. The thermocompression bonding pressure may be, for example, 0.5 to 1.5 MPa. The thermocompression bonding time may be, for example, 0.5 to 1.5 seconds.

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 hardly flow during the thermocompression bonding, and the conductive particles are efficiently produced. Since it is 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. Further, the circuit connection structure 10 has a sufficiently small connection resistance between the opposing electrodes, and even when used for a long period of time in a high temperature and high humidity environment, the circuit connection portion and the circuit member are separated from each other. Is unlikely to occur, and the connection reliability can be excellent.

Further, in the method shown in FIG. 3, the third adhesive layer 6 of the circuit connection adhesive film 1a is arranged on the second circuit member 16 side, so that the circuit connection portion 17 and the second circuit are particularly arranged. It becomes easy to improve the peeling resistance between the member 16 and the member 16.

FIG. 4 is a schematic cross-sectional view showing a method of manufacturing the circuit connection structure 10 when the circuit connection adhesive film 1b is used. The method shown in FIG. 4 uses a circuit connection adhesive film 1b instead of the circuit connection adhesive film 1a, except that the third adhesive layer 6 is arranged on the first circuit member 13 side. The circuit connection structure 10 can be manufactured in the same manner as the method shown in FIG. In the method shown in FIG. 4, the third adhesive layer 6 of the circuit connection adhesive film 1b is arranged on the first circuit member 13 side, so that the circuit connection portion 17 and the first circuit member 13 are particularly arranged. It becomes easy to improve the peeling resistance between the two.

By the way, due to the movement to reduce the amount of adhesive film used for the purpose of reducing the manufacturing cost of LCD and the demand for a narrow frame panel design, the adhesive film is first applied to flexible substrates such as COF or FPC. In some cases, a manufacturing method of pasting is adopted. A method for manufacturing a circuit connection structure in such a case is, for example, as shown in FIGS. 5 and 6, a first circuit member 23 having a first electrode 22 and a second circuit member 23 having a second electrode 25. Adhesive film with a substrate (for circuit connection with a substrate) having an adhesive film (adhesive film for circuit connection) 1a or an adhesive film (adhesive film for circuit connection) 1b on the circuit member 26 of The step of preparing the adhesive film) and the step of transferring (laminating) the adhesive film 1a or the adhesive film 1b from the base material onto the surface on which the first electrode 22 of the first circuit member 23 is formed. The first circuit member 23 and the adhesive film 1a or the adhesive film 1b and the second circuit member 26 are arranged in this order so that the first electrode 22 and the second electrode 25 face each other. After that, the first circuit member 23 and the second circuit member 26 are thermally crimped to provide a step of electrically connecting the first electrode 22 and the second electrode 25 to each other.

Examples of the first circuit member 23 include members having a flexible substrate such as COP, FCP, and polyimide. The first electrode 22 may be, for example, copper plated with a metal such as tin. An insulating layer may be formed on the mounting surface 21a where the electrode 22 is not formed.

Examples of the second circuit member 26 include a glass substrate or a plastic substrate whose circuit is formed of ITO, IZO, metal or the like used for a liquid crystal display, a ceramic wiring board, or the like. The second electrode 25 has, for example, a rectangular shape in a plan view, and may have a thickness of, for example, about 100 nm to 1000 nm. The surface of the electrode 25 is one or two selected from, for example, gold, silver, copper, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, indium tin oxide (ITO), and indium zinc oxide (IZO). It may be composed of more than a seed material. Also on the mounting surface 24a, an insulating layer may be formed on a portion where the electrode 25 is not formed.

The base material included in the adhesive film with a base material may be the base material used for producing the above-mentioned adhesive film.

In the method shown in FIG. 5, the circuit connection adhesive film 1a is laminated so that the third adhesive layer 6 is in contact with the mounting surface 21a of the first circuit member 23. In the method shown in FIG. 6, the circuit connection adhesive film 1b is laminated so that the second adhesive layer 3 is in contact with the mounting surface 21a of the first circuit member 23.

The laminating method is not particularly limited, but a roll laminator, a diaphragm type laminator, a vacuum roll laminator, and a vacuum diaphragm type laminator can be adopted. After temporary laminating, crimping may be performed using a thermocompression bonding device. The temperature at the time of laminating (crimping temperature) may be, for example, 50 to 90 ° C. The pressure at the time of laminating (crimping pressure) may be, for example, 0.5 to 1.5 MPa. The laminating time (crimping time) may be, for example, 0.5 to 1.5 seconds.

According to the method shown in FIG. 5, it becomes easy to improve the peel resistance between the first circuit member and the circuit connection portion. According to the method shown in FIG. 6, it becomes easy to improve the peel resistance between the second circuit member and the circuit connection portion.

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 under 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 a gel permeation chromatograph (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 Kasei Co., Ltd.
Sample concentration: 120 mg / 3 mL
Solvent: Tetrahydrofuran Injection amount: 60 μL
Pressure: 2.94 × 10 ⁶ Pa (30 kgf / cm ² )
Flow rate: 1.00 mL / min

<Manufacturing of 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 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. 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. This caused a white precipitate to precipitate. Then, the white precipitate was taken out, washed with water, and vacuum dried to obtain a polyester polyol. After the obtained polyester polyol was sufficiently dried, it was dissolved in MEK (methyl ethyl ketone) and placed in a four-necked flask equipped with a stirrer, a dropping funnel, a reflux condenser and a nitrogen gas introduction tube. Further, dibutyltin dilaurate 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 was added in an amount of 50 parts by mass with respect to 100 parts by mass of the polyester polyol. The target polyester urethane resin was obtained by dissolving it in MEK, adding it with a dropping funnel, and stirring it at 80 ° C. for 4 hours.

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

(Polymerizable compound)
A1: Diacrylate having a tricyclodecane skeleton (trade name: DCP-A, manufactured by Kyoeisha Chemical 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)
(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: Phenoxy resin (trade name: PKHC, manufactured by Union Carbide)
(Coupling agent)
F1: 3-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.)
(Filler)
G1: Silica fine particles (trade name: R104, manufactured by Nippon Aerodil Co., Ltd., average particle size (primary particle size): 12 nm)
(solvent)
H1: Methyl ethyl ketone

<Preparation of varnish (varnish composition) of thermosetting composition 2-1>
As polymerizable compounds a1 to a3, a thermal polymerization initiator c1, a coupling agent F1, a filler G1 and a solvent H1, the polymerizable compounds A1 to A3 in a light and thermosetting composition, a thermal polymerization initiator C1, and a coupling agent. Using the same materials as F1, the filler G1 and the solvent H1, the thermoplastic resin E2 uses the components shown below, and these components are mixed in the blending amounts (parts by mass) shown in Table 2 to form a thermosetting composition 2. A -1 varnish was prepared.

(Thermoplastic resin)
E2: Polyester urethane resin synthesized as described above

<Preparation of varnish (varnish composition) of thermosetting compositions 3-1 to 3-9>
As the polymerizable compounds P1 to P3, the thermal polymerization initiator Q1, the coupling agent F1, the filler G1 and the solvent H1, the polymerizable compounds A1 to A3 in the light and thermosetting composition, the thermal polymerization initiator C1, and the coupling agent. The same materials as F1, the filler G1 and the solvent H1 are used, and the same thermoplastic resin E3 as the above-mentioned thermoplastic resin E2 is used. These components are mixed in the blending amount (part by mass) shown in Table 3 and heated. The varnishes of curable compositions 3-1 to 3-9 were prepared.

(Example 1)
[Preparation of first adhesive film]
The varnish of the light and thermosetting composition 1-1 was applied onto a PET film having a thickness of 50 μm using a coating device. Then, it was dried with hot air at 70 ° C. for 3 minutes to form a layer composed of a light and thermosetting composition having a thickness (thickness after drying) of 4 μm on the PET film. The thickness here was measured using a contact thickness gauge. Next, the layer composed of light and the thermosetting composition 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 was cured to form a first adhesive layer. By the above operation, a first adhesive film having a first adhesive layer having a thickness of 4 μm on the PET film was obtained. The conductive particle density at this time was about 7000 pcs / mm ² . When the thickness of the first adhesive layer is smaller than the thickness (diameter) of the conductive particles, the thickness of the layer is measured using a contact type thickness gauge, and the thickness of the conductive particles is reflected to be conductive. The thickness of the area where the particles are present is measured. Therefore, after producing a circuit-connecting adhesive film having a three-layer structure in which a first adhesive layer, a second adhesive layer, and a third adhesive layer are laminated, adjacent conductivity is applied by the above-mentioned method. The thickness of the first adhesive layer located at the separated portion of the particles was measured.

[Preparation of second adhesive film]
The varnish of the thermosetting composition 2-1 was applied onto a PET film having a thickness of 50 μm using a coating device. Then, it was dried with hot air at 70 ° C. for 3 minutes to form a second adhesive layer (layer composed of the thermosetting composition 2-1) having a thickness of 7 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 a third adhesive film]
The varnish of the thermosetting composition 3-1 was applied onto a PET film having a thickness of 50 μm using a coating device. Then, it was dried with hot air at 70 ° C. for 3 minutes to form a third adhesive layer (layer made of thermosetting composition 3-1) having a thickness of 1.5 μm on the PET film. By the above operation, a third adhesive film having a third adhesive layer on the PET film was obtained.

[Manufacturing adhesive film for circuit connection]
The first adhesive film and the third adhesive film are laminated with a roll laminator while being heated at 40 ° C. together with the PET film as a base material, and the base material of the third adhesive film is peeled off from this surface. The second adhesive film is put together with the PET film, which is a base material, and laminated with a roll laminator while heating at 40 ° C., and the base material of the first adhesive film is peeled off. As a result, a three-layer structure in which the first adhesive layer, the third adhesive layer, and the second adhesive layer are laminated in this order (first adhesive layer / third adhesive layer / An adhesive film for circuit connection of the second adhesive layer) was produced.

[Creation 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: 1200 Å) made of amorphous indium tin oxide (ITO) on a glass substrate via the produced adhesive film for circuit connection. Using a heat-bonding device (heating method: constant heat type, manufactured by Taiyo Kikai Co., Ltd.), the glass substrate with a glass substrate (manufactured by Geomatec) is heated and pressed at 170 ° C. and 6 MPa for 4 seconds. 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 connection resistance value]
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 constant humidity bath at 85 ° C. and 85% RH for 200 hours. The connection resistance value was obtained as the average value of 16 resistance points between the opposing electrodes.

[Evaluation of peel resistance]
The presence or absence of peeling in 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 percentage of the total area of the adhesive film for circuit connection that was peeled off from the glass substrate was determined and evaluated on a three-point scale according to the following criteria.
A: The ratio of the peeled part is less than 5% of the whole (the peeling hardly occurs)
B: The ratio of the peeled part is 5% or more and less than 20% of the whole (a small amount of peeling occurs)
C: The ratio of the peeled part is 20% or more of the whole (peeling has occurred)

(Examples 2 to 6)
As the thermosetting composition forming the third adhesive layer, the same as in Example 1 except that the thermosetting compositions 3-2 to 3-6 were used instead of the thermosetting composition 3-1. In the same manner, an adhesive film for circuit connection and a circuit connection structure were produced, and the circuit connection structure was evaluated in the same manner as in Example 1. The results are shown in Table 4.

(Example 7)
As the thermosetting composition for forming the third adhesive layer by changing the thickness of the second adhesive layer to 5.5 μm, the thermosetting composition 3 replaces the thermosetting composition 3-1. An adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1 except that the thickness of the third adhesive layer was changed to 3 μm using -7, and the same as in Example 1. Then, the circuit connection structure was evaluated. The results are shown in Table 4.

(Example 8)
As the thermosetting composition for forming the third adhesive layer by changing the thickness of the second adhesive layer to 8 μm, the thermosetting composition 3-8 is replaced with the thermosetting composition 3-1. In the same manner as in Example 1 except that the thickness of the third adhesive layer was changed to 0.5 μm, an adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1. Then, the circuit connection structure was evaluated. The results are shown in Table 4.

(Comparative Example 1)
The adhesive film for circuit connection and the circuit connection structure were formed in the same manner as in Example 1 except that the thickness of the second adhesive layer was changed to 8.5 μm and the third adhesive layer was not provided. It was prepared and the circuit connection structure was evaluated in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 2)
As the thermosetting composition for forming the third adhesive layer by changing the thickness of the second adhesive layer to 4.5 μm, the thermosetting composition 3 replaces the thermosetting composition 3-1. An adhesive film for circuit connection and a circuit connection structure were produced in the same manner as in Example 1 except that the thickness of the third adhesive layer was changed to 4 μm using -9, and the same as in Example 1. Then, the circuit connection structure was evaluated. The results are shown in Table 4.

1a, 1b ... Circuit connection adhesive film, 2 ... First adhesive layer, 3 ... Second adhesive layer, 4 ... Conductive particles, 6 ... Third adhesive layer, 10 ... Circuit connection structure, 12, 22 ... 1st electrode, 13, 23 ... 1st circuit member, 15, 25 ... 2nd electrode, 16, 26 ... 2nd circuit member.

Claims (10)

An adhesive film for circuit connection containing conductive particles.
The conductive particles are unevenly distributed on one side of the adhesive film.
The adhesive film contains a region S composed of a thermosetting composition containing no conductive particles in the thickness direction of the film.
The region S includes a region HF1 in which the content of the filler is 5 to 50% by mass in the thickness direction of the film.
An adhesive film for circuit connection, wherein the ratio of the width of the region HF1 to the width of the region S is 1 to 26.5%. An adhesive film for circuit connection containing conductive particles.
The conductive particles are unevenly distributed on one side of the adhesive film.
The adhesive film contains a region S composed of a thermosetting composition containing no conductive particles in the thickness direction of the film.
The region S is a region HF2 in which the content of the filler is 1.3 Ms mass% or more when the average content of the filler in the region S is Ms (mass%) in the thickness direction of the film. Including,
An adhesive film for circuit connection, wherein the ratio of the width of the region HF2 to the width of the region S is 1 to 26.5%. The circuit connection adhesive according to claim 1 or 2, wherein the adhesive film contains a region P containing light containing conductive particles and a photocurable product of a thermosetting resin composition in the thickness direction of the film. the film. The circuit connection adhesive film according to claim 3, wherein the region S is provided adjacent to the region P. The circuit connection adhesive film according to any one of claims 1 to 4, wherein the width of the region S is 5 to 200 μm. A first adhesive layer, a second adhesive layer, and a third adhesive layer are provided.
The second adhesive layer and the third adhesive layer are laminated on the first adhesive layer in this order or vice versa.
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 comprises a thermosetting composition.
The third adhesive layer comprises a thermosetting composition containing a filler.
The content (mass%) of the filler in the third adhesive layer is 5 to 50% by mass based on the total mass of the third adhesive layer.
An adhesive film for circuit connection, wherein the ratio of the thickness of the third adhesive layer to the total thickness of the second adhesive layer and the third adhesive layer is 1 to 26.5%. A first adhesive layer, a second adhesive layer, and a third adhesive layer are provided.
The second adhesive layer and the third adhesive layer are laminated on the first adhesive layer in this order or vice versa.
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 comprises a thermosetting composition.
The third adhesive layer comprises a thermosetting composition containing a filler.
When the content (mass%) of the filler in the third adhesive layer is M (mass%) when the average content of the filler in the second adhesive layer and the third adhesive layer is M (mass%). In addition, it is 1.3M (mass%) or more,
An adhesive film for circuit connection, wherein the ratio of the thickness of the third adhesive layer to the total thickness of the second adhesive layer and the third adhesive layer is 1 to 26.5%. The adhesive film for circuit connection according to claim 6 or 7, wherein the total thickness of the second adhesive layer and the third adhesive layer is 5 to 200 μm. 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. .. A first circuit member having a first electrode and
A second circuit member having a second electrode and
A circuit connection portion that is arranged between the first circuit member and the second circuit member and electrically connects the first electrode and the second electrode to each other.
Equipped with
A circuit connection structure in which the circuit connection portion contains a cured product of the adhesive film for circuit connection according to any one of claims 1 to 8.

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