CN116635495A

CN116635495A - Adhesive film for circuit connection, method for producing same, and method for producing circuit connection structure

Info

Publication number: CN116635495A
Application number: CN202180075294.2A
Authority: CN
Inventors: 伊藤彰浩; 大当友美子; 工藤直
Original assignee: Lishennoco Co ltd
Current assignee: Lishennoco Co ltd
Priority date: 2020-09-15
Filing date: 2021-09-13
Publication date: 2023-08-22
Also published as: WO2022059647A1; KR20230068406A; JPWO2022059647A1; TW202223028A

Abstract

An adhesive film (1) for circuit connection, which comprises a 1 st adhesive layer (2) and a 2 nd adhesive layer (3) laminated on the 1 st adhesive layer (2), wherein the 1 st adhesive layer (2) comprises a cured product of a light and a thermosetting composition, and the 2 nd adhesive layer (3) comprises a thermosetting composition, and the light and thermosetting composition comprises a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, conductive particles (4) and a thiol compound.

Description

Adhesive film for circuit connection, method for producing same, and method for producing circuit connection structure

Technical Field

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

Background

Conventionally, various adhesive materials have been used for circuit connection. For example, as an adhesive material used for connection of a liquid crystal display and a Tape Carrier Package (TCP), connection of a flexible printed circuit board (FPC) and TCP, or connection of an FPC and a printed circuit board, an adhesive film for circuit connection having anisotropic conductivity in which conductive particles are dispersed in an adhesive is used.

The adhesive film for circuit connection is usually stored in a state of being laminated on a substrate. Therefore, when the circuit-connecting adhesive film is used to connect the circuit members, it is first necessary to transfer the circuit-connecting adhesive film to the circuit members. In this case, if the transferability of the adhesive film for circuit connection is insufficient, there is a possibility that productivity is lowered due to a longer transfer time, connection resistance is raised due to insufficient adhesion between circuits, and adhesion force is lowered, and therefore, the adhesive film for circuit connection needs to have sufficient transferability.

In the field of precision electronic devices using an adhesive film for circuit connection having anisotropic conductivity, the density of circuits has been increased, and the electrode width and electrode spacing have become extremely narrow. Therefore, it is not necessarily easy to efficiently capture conductive particles on the minute electrode and obtain high connection reliability. In contrast, for example, patent document 1 proposes a method in which conductive particles are separated from each other by being offset to one side of an anisotropic conductive adhesive sheet.

Technical literature of the prior art

Patent literature

Patent document 1: international publication No. 2005/54388

Disclosure of Invention

Technical problem to be solved by the invention

However, in the method of patent document 1, since the conductive particles flow at the time of circuit connection, there is a possibility that the conductive particles are aggregated between the electrodes and short-circuit occurs. The dense distribution of the conductive particles formed in accordance with the flow of the conductive particles may not only cause a decrease in insulation characteristics but also cause a variation in connection resistance value, leaving room for improvement.

In contrast, the inventors of the present invention have found, as a result of diligent studies, that by photocuring an adhesive agent in advance in a region where conductive particles are present, the flow of conductive particles at the time of circuit connection can be suppressed, but this method does not obtain sufficient transferability, and peeling may occur at the interface between a circuit member and an adhesive film.

Accordingly, an object of the present invention is to provide an adhesive film for circuit connection, which has sufficient transferability and can suppress the flow of conductive particles generated at the time of manufacturing a circuit connection structure, a method for manufacturing the same, and a method for manufacturing a circuit connection structure using the adhesive film.

Means for solving the technical problems

One aspect of the present invention relates to an adhesive film for circuit connection shown below.

An adhesive film for circuit connection, comprising a 1 st adhesive layer and a 2 nd adhesive layer laminated on the 1 st adhesive layer, wherein the 1 st adhesive layer comprises a cured product of a light and a thermosetting composition, and the 2 nd adhesive layer comprises a thermosetting composition, and the light and thermosetting composition comprises a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, conductive particles and a thiol compound.

[2] The adhesive film for circuit connection according to [1], wherein,

the polymerizable compound includes a radical polymerizable compound.

[3] The adhesive film for circuit connection according to [2], wherein,

the radically polymerizable compound includes a (meth) acrylate compound.

[4] The adhesive film for circuit connection according to any one of [1] to [3], wherein,

the thiol compound is contained in an amount of 0.05 to 5.0 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition.

[5] The adhesive film for circuit connection according to any one of [1] to [4], wherein,

the thermosetting composition comprises a free radical polymerizable compound.

[6] The adhesive film for circuit connection according to any one of [1] to [5], wherein,

The thickness of the 1 st adhesive layer is 0.1 to 0.8 times the average particle diameter of the conductive particles.

According to the adhesive film for circuit connection of the above aspect, the flow of conductive particles generated at the time of manufacturing the circuit connection structure can be suppressed, and peeling at the interface of the circuit member and the adhesive film due to insufficient transferability can also be suppressed.

According to the adhesive film for circuit connection of the above aspect, peeling at the interface between the circuit member and the circuit connection portion, which occurs when the circuit connection structure is used for a long period of time in a high-temperature and high-humidity environment (for example, 85 ℃ and 85% rh), tends to be suppressed.

[7] A method for producing an adhesive film for circuit connection according to any one of [1] to [6], comprising a step of forming the 1 st adhesive layer by irradiating the layer containing the light and the thermosetting composition with light and curing the light and the thermosetting composition.

[8] A method for manufacturing a circuit connection structure includes:

a step of preparing a 1 st circuit member having a 1 st electrode, a 2 nd circuit member having a 2 nd electrode, and the adhesive film for circuit connection with a substrate having the adhesive film for circuit connection of any one of [1] to [6] on a substrate; a step of transferring the circuit-connecting adhesive film from the base material to a surface of the 1 st circuit member on which the 1 st electrode is formed; and a step of thermally bonding the 1 st circuit member and the 2 nd circuit member to electrically connect the 1 st electrode and the 2 nd electrode after the 1 st circuit member, the adhesive film for circuit connection, and the 2 nd circuit member are sequentially arranged so that the 1 st electrode and the 2 nd electrode face each other.

Effects of the invention

According to the present invention, it is possible to provide an adhesive film for circuit connection, which has sufficient transferability and can suppress the flow of conductive particles generated at the time of manufacturing a circuit connection structure, a method for manufacturing the same, and a method for manufacturing a circuit connection structure using the adhesive film.

Drawings

Fig. 1 is a schematic cross-sectional view showing an adhesive film for circuit connection according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing a circuit connection structure according to an embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view showing a process for manufacturing a circuit connection structure according to an embodiment of the present invention.

Detailed Description

In the present specification, the numerical ranges shown in "to" are ranges including the numerical values before and after "to" as the minimum value and the maximum value, respectively. In the numerical ranges described in the present specification in stages, the upper limit value or the lower limit value of the numerical range in one stage may be replaced with the upper limit value or the lower limit value of the numerical range in another stage. In the numerical ranges 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 embodiment. The upper limit and the lower limit described individually can be arbitrarily combined. In the present specification, "(meth) acrylate" means at least one of an acrylate and a methacrylate corresponding thereto. The same applies to other similar expressions such as "(meth) acryl". "(poly)" refers to both cases where there is a "poly" prefix and cases where there is no "poly" prefix. "A or B" may include either or both of A and B. The materials exemplified below may be used alone or in combination of 1 or 2 or more, unless otherwise specified. The content of each component in the composition means the total amount of a plurality of substances present in the composition, unless otherwise specified, in the case where the plurality of substances corresponding to each component are present in the composition.

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

Adhesive film for circuit connection

Fig. 1 is a schematic cross-sectional view showing an adhesive film for circuit connection according to an embodiment. As shown in fig. 1, an adhesive film 1 for circuit connection (hereinafter, simply referred to as "adhesive film 1") includes a 1 st adhesive layer 2 and a 2 nd adhesive layer 3 laminated on the 1 st adhesive layer 2.

(1 st adhesive layer)

The 1 st adhesive layer 2 contains a cured product (for example, a photo-cured product) of a photo-and thermosetting composition. The 1 st adhesive layer 2 is composed of, for example, a photo-cured product of a photo-curable and thermosetting composition. Wherein the 1 st adhesive layer 2 is further curable by heating. Thus, the 1 st adhesive layer 2 can be said to have thermosetting properties. The 1 st adhesive layer 2 can also be modified to be a cured product of a layer containing a light and a thermosetting composition (for example, a layer composed of a light and a thermosetting composition). The photo-and thermosetting composition contains (a) a polymerizable compound (hereinafter, also referred to as "(a) component"), (B) a photopolymerization initiator (hereinafter, also referred to as "(B) component"), (C) a thermal polymerization initiator (hereinafter, also referred to as "(C) component"), (D) conductive particles (hereinafter, also referred to as "(D) component") and (E) a thiol compound.

For example, the 1 st adhesive layer 2 is obtained by irradiating a layer containing light and a thermosetting composition with light energy to polymerize the component (a) and curing (photo-curing) the light and the thermosetting composition. Therefore, the 1 st adhesive layer 2 includes, for example, the conductive particles 4 and the adhesive component 5 obtained by curing components other than the conductive particles 4 in the light and thermosetting composition. The binder component 5 includes, for example, a polymer of component (a) and component (C). The binder component may comprise the component (a) or the reaction product of the polymer of the component (a) and the component (E). That is, when the component (A) is polymerized, the component (E) reacts with the component (A) or the polymer of the component (A), whereby the component (E) can be incorporated into the polymer of the component (A). The binder component 5 may or may not contain unreacted component (a), component (B) and component (E).

[ (A) component: polymerizable Compound

(A) The components are compounds which polymerize, for example, by free radicals, cations or anions. Thus, the component (A) is polymerized when the photopolymerization initiator generates radicals, cations or anions by irradiation with light (e.g., ultraviolet light). (A) The component may be any of monomers, oligomers or polymers. As the component (a), 1 kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

(A) The component (a) has at least one polymerizable group. The polymerizable group may be a polymerizable group by a radical reaction (i.e., a radical polymerizable group) from the viewpoint of further improving the effect of reducing the connection resistance and obtaining more excellent connection reliability. That is, the component (A) may be a radical polymerizable compound. Examples of the radical polymerizable group include a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenylene group, a (meth) acryl group, a (meth) acryloyloxy group, and a maleimide group.

The number of polymerizable groups in component (a) may be 2 or more from the viewpoint of easily obtaining physical properties and crosslinking density required for reducing the connection resistance after polymerization. The number of polymerizable groups in the component (a) may be 10 or less from the viewpoint of suppressing cure shrinkage during polymerization. In view of obtaining a uniform and stable film (1 st adhesive layer) after irradiation with light, it is preferable to suppress curing shrinkage at the time of polymerization. In the present embodiment, in order to maintain the balance between the crosslinking density and the curing shrinkage, a polymerizable compound having a number of polymerizable groups outside the above range may be additionally used in addition to a polymerizable compound having a number of polymerizable groups within the above range.

Specific examples of the component (a) include (meth) acrylate compounds, maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, imide (Nadiimide) derivatives, natural rubber, isoprene rubber, butyl rubber, nitrile rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, carboxylated nitrile rubber, and the like.

Examples of the (meth) acrylate compound include epoxy (meth) acrylate, (poly) urethane (meth) acrylate, (meth) acrylate methyl ester, polyether (meth) acrylate, polyester (meth) acrylate, polybutadiene (meth) acrylate, polysiloxaneacrylate, ethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, N-hexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, isopropyl (meth) acrylate, hydroxypropyl (meth) acrylate, isobutyl (meth) acrylate, isobornyl (meth) acrylate, 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-dimethylaminoethyl (meth) acrylate, N, n-dimethylaminopropyl (meth) acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polyethylene glycol di (meth) acrylate, polyalkylene glycol di (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol (meth) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid modified 2-functional (meth) acrylate, isocyanuric acid modified 3-functional (meth) acrylate, tricyclodecane acrylate, dimethylol-tricyclodecane diacrylate, 2-hydroxy-1, 3-acryloxypropane, 2-bis [4- (acryloxymethoxy) phenyl ] propane, 2-bis (meth) acryloxydiethyl phosphate, 2- (meth) acryloxyethyl acid phosphate, and the like.

Examples of the maleimide compound include 1-methyl-2, 4-bismaleimide benzene, N ' -m-phenylene bismaleimide, N ' -p-phenylene bismaleimide, N ' -m-toluene bismaleimide, N, N ' -4, 4-biphenylene bismaleimide, N ' -4,4- (3, 3' -dimethyl-biphenylene) bismaleimide, N ' -4,4- (3, 3' -dimethyl-diphenyl methane) bismaleimide, N ' -4,4- (3, 3' -diethyl-diphenyl methane) bismaleimide, N, N ' -4, 4-diphenylmethane bismaleimide, N ' -4, 4-diphenylpropane bismaleimide, N ' -4, 4-diphenylether bismaleimide, N, N ' -3, 3-diphenylsulfone bismaleimide, 2-bis (4- (4-maleimidophenoxy) phenyl) propane, 2-bis (3-sec-butyl-4-8 (4-maleimidophenoxy) phenyl) propane, 1-bis (4- (4-maleimidophenoxy) phenyl) decane, 4' -cyclohexylidene-bis (1- (4-maleimidophenoxy) -2-cyclohexyl) benzene, 2,2' -bis (4- (4-maleimidophenoxy) 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 diallyl 1, 3-phthalate, diallyl 1, 2-phthalate, and triallyl isocyanurate.

The component (a) may contain a (meth) acrylate compound from the viewpoint of excellent balance between the curing reaction rate and the physical properties after curing.

The component (a) may contain a (poly) urethane (meth) acrylate compound from the viewpoint of achieving both of the cohesive force for reducing the connection resistance and the elongation for improving the adhesive force, and obtaining more excellent transferability and more excellent adhesive properties. From the viewpoint of obtaining more excellent transferability and more excellent adhesive properties, the content of the (poly) urethane (meth) acrylate compound may be 30 mass% or more, 50 mass% or more, or 70 mass% or more, 96 mass% or less, 93 mass% or less, or 90 mass% or less, or 30 to 96 mass%, 50 to 93 mass%, or 70 to 90 mass% based on the total mass of the component (a).

The component (a) may contain a (meth) acrylate compound having a high Tg skeleton such as a tricyclodecane skeleton from the viewpoint of improving the cohesive force and reducing the connection resistance, and obtaining more excellent transferability. The (meth) acrylate compound having a high Tg skeleton preferably has 2 or more (meth) acryloyloxy groups, more preferably 2 (i.e., is a diacrylate). From the viewpoint of further improving the cohesive force and further reducing the connection resistance and obtaining further excellent transferability, the content of the (meth) acrylate compound having a high Tg skeleton may be 3 mass% or more, 6 mass% or more, or 9 mass% or more, 30 mass% or less, 20 mass% or less, or 15 mass% or less, or 3 to 30 mass%, 6 to 20 mass%, or 9 to 15 mass% based on the total mass of the component (a).

The component (a) may contain a compound (for example, urethane (meth) acrylate) having a polymerizable group such as a vinyl group, an allyl group, or a (meth) acryloyloxy group introduced into the terminal or side chain of a thermoplastic resin such as an acrylic resin, a phenoxy resin, or a urethane resin, from the viewpoint of maintaining the balance between the crosslinking density and the curing shrinkage, further reducing the connection resistance, improving the connection reliability, and obtaining more excellent transferability.

The weight average molecular weight of the compound having a polymerizable group introduced into the terminal or side chain of the thermoplastic resin may be 3000 or more, 5000 or more, or 1 ten thousand or more, from the viewpoint of excellent balance between the crosslinking density and the curing shrinkage. The weight average molecular weight of the compound having a polymerizable group introduced into the terminal or side chain of the thermoplastic resin may be 100 ten thousand or less, 50 ten thousand or less or 25 ten thousand or less from the viewpoint of excellent compatibility with other components (e.g., component (E)). In addition, the weight average molecular weight in the present specification refers to a value measured by Gel Permeation Chromatography (GPC) and using a calibration curve based on standard polystyrene.

From the viewpoint of further reducing the connection resistance and further improving the connection reliability and obtaining further excellent transferability, the content of the compound having a radical polymerizable group introduced into the terminal or side chain of the thermoplastic resin may be 30 mass% or more, 50 mass% or more or 70 mass% or more, 96 mass% or less, 93 mass% or less or 90 mass% or less, or 30 to 96 mass%, 50 to 93 mass% or 70 to 90 mass% based on the total mass of the component (a).

(A) The component (c) may contain a (meth) acrylate compound represented by the following formula (1) (a (meth) acrylate compound having a phosphate structure). In this case, the adhesive strength with the surface of the inorganic substance (metal or the like) is improved, and the adhesion of the electrodes (for example, the circuit electrodes) to each other is improved.

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

The (meth) acrylate compound represented by the formula (1) is obtained, for example, by reacting phosphoric anhydride with 2-hydroxyethyl (meth) acrylate. Specific examples of the (meth) acrylate compound represented by the formula (1) include mono (2- (meth) acryloyloxyethyl) acid phosphate and the like, di (2- (meth) acryloyloxyethyl) acid phosphate and the like.

From the viewpoint of further improving the adhesion to the surface of an inorganic substance (metal or the like) and further improving the adhesion strength between electrodes (for example, between circuit electrodes), the content of the (meth) acrylate compound represented by the formula (1) may be 0.1 mass% or more, 0.5 mass% or more, or 1 mass% or more, 20 mass% or less, 10 mass% or less, or 5 mass% or less, or 0.1 to 20 mass%, 0.5 to 10 mass%, or 1 to 5 mass% based on the total mass of the component (a).

The content of the component (a) may be 5 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, or 40 mass% or more based on the total amount of components other than the conductive particles in the light and thermosetting composition, from the viewpoint of easily obtaining a cross-linking density necessary for further reducing the connection resistance and further improving the connection reliability and further suppressing the flow of the conductive particles. The content of the component (a) may be 90 mass% or less, 80 mass% or less, 70 mass% or less, or 60 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition, from the viewpoint of suppressing curing shrinkage at the time of polymerization and obtaining further excellent transferability. From these viewpoints, the content of the component (a) may be 5 to 90 mass%, 10 to 80 mass%, 20 to 70 mass%, 30 to 60 mass%, or 40 to 60 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition. The "total amount of components other than the conductive particles in the light and thermosetting composition" does not include the amount of the solvent used for forming the layer.

[ (B) component: photopolymerization initiator ]

(B) The component may be a photo radical polymerization initiator, a photo cation polymerization initiator or a photo anion polymerization initiator. (B) The component generates radicals, cations, and anions by, for example, irradiating light having a wavelength in the range of 150 to 750nm, preferably light having a wavelength in the range of 254 to 405nm, and more preferably light having a wavelength of 365nm (e.g., ultraviolet light). The component (B) may be a photo radical polymerization initiator from the viewpoint of easy curing in a short time at low temperature. As the component (B), 1 kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The photo radical polymerization initiator is decomposed by light and generates free radicals. That is, the photo radical polymerization initiator is a compound that generates radicals by applying light energy from the outside. Examples of the photo-radical polymerization initiator include photopolymerization initiators having an oxime ester structure, a bisimidazole structure, an acridine structure, an α -aminoalkylbenzophenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethyl ketal structure, and an α -hydroxyalkylbenzophenone structure.

As the component (B), a photopolymerization initiator having a structure represented by the following formula (I) may be used from the viewpoint of further improving the flow suppressing effect of the conductive particles and the peeling suppressing effect after transfer.

The photopolymerization initiator may have a plurality of structures represented by formula (I). The structure represented by formula (I) may be an oxime ester structure, a bisimidazole structure or an acridine structure. That is, the photo-and thermosetting composition may contain at least one photopolymerization initiator selected from the group consisting of a photopolymerization initiator having an oxime ester structure, a photopolymerization initiator having a bisimidazole structure, and a photopolymerization initiator having an acridine structure. Among them, 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 after transfer tend to be further improved.

In the case of using a compound having a structure represented by the following formula (VI) among compounds having an oxime ester structure, the above-mentioned effect tends to be more remarkably obtained.

In the formula (VI), R ¹¹ 、R ¹² R is R ¹³ Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an organic group containing an aromatic hydrocarbon group.

Specific examples of the compound having an oxime ester structure include 1-phenyl-1, 2-butanedione-2- (o-methoxycarbonyl) oxime, 1-phenyl-1, 2-propanedione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-1, 2-propanedione-2-o-benzoyloxime, 1, 3-diphenylpropanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxypropanetrione-2- (o-benzoyl) oxime, 1, 2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (o-benzoyl oxime) ], ethanone, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -,1- (o-acetyloxime) and the like.

Examples of the compound having a bisimidazole structure include 2,4, 5-triarylimidazole dimers such as 2- (o-phenyl) -4, 5-diphenylimidazole dimer, 2- (o-phenyl) -4, 5-bis (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-bis (p-methoxyphenyl) -5-phenylimidazole dimer, and 2- (2, 4-dimethoxyphenyl) -4, 5-diphenylimidazole dimer.

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

The content of the photopolymerization initiator having the structure represented by the above formula (I) may be 0.1 mass% or more, 0.3 mass% or more, 0.45 mass% or more, 0.55 mass% or more, or 0.85 mass% or more based on the total amount of components other than the conductive particles in the light and thermosetting composition, from the viewpoint of further improving the flow inhibiting effect of the conductive particles. The content of the photopolymerization initiator having the structure represented by the above formula (I) may be 1.2 mass% or less, 0.9 mass% or less, or 0.6 mass% or less based on the total amount of components other than the conductive particles in the light and thermosetting composition, from the viewpoint of further improving the peeling inhibiting effect after transfer. From these viewpoints, the content of the photopolymerization initiator having the structure represented by the above formula (I) may be 0.1 to 1.2 mass%, 0.3 to 1.2 mass%, 0.45 to 0.9 mass%, or 0.45 to 0.6 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition.

From the viewpoint of further improving the flow suppressing effect of the conductive particles, the content of the component (B) (the total of the contents of photopolymerization initiators) may be 0.3 mass% or more, 0.45 mass% or more, 0.55 mass% or more, or 0.85 mass% or more based on the total amount of the components other than the conductive particles in the light and thermosetting composition. The content of the component (B) may be 1.2 mass% or less, 0.9 mass% or less, or 0.6 mass% or less based on the total amount of the components other than the conductive particles in the light and thermosetting composition, from the viewpoint of further improving the peeling inhibiting effect after transfer. From these viewpoints, the content of the component (B) may be 0.3 to 1.2 mass%, 0.45 to 0.9 mass%, or 0.45 to 0.6 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition.

[ (C) component: thermal polymerization initiator ]

(C) The component may be a polymerization initiator (thermal radical polymerization initiator, thermal cationic polymerization initiator, or thermal anionic polymerization initiator) that generates radicals, cations, or anions from heat. The component (C) may be a thermal radical polymerization initiator from the viewpoint of further improving the effect of reducing the connection resistance and further improving the connection reliability. As the component (C), 1 kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The thermal radical polymerization initiator is decomposed by heat and generates 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 may be 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 inhibition effect of the conductive particles and the peeling inhibition effect after transfer, and may be an organic peroxide having a half-life temperature of 90 to 175 ℃ in 1 minute and a weight average molecular weight of 180 to 1000 from the viewpoint of improving stability, reactivity and compatibility. In the case where the 1-minute half-life temperature of the organic peroxide is in the above range, the storage stability tends to be more excellent, and sufficiently high radical polymerizability is obtained, so that curing can also be performed in a short time.

As a specific example of the component (C), examples of the compounds include 1, 3-tetramethylbutyl peroxyneodecanoate, bis (4-t-butylcyclohexyl) peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylpivalate, 1, 3-tetramethylbutyl peroxy-2-ethylhexanoate, 2, 5-dimethyl-2, 5-bis (2-ethylhexanoate) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate tert-butyl neoheptanoate, tert-amyl peroxy-2-ethylhexanoate, di-tert-butyl hexahydroterephthalate, tert-amyl peroxy-3, 5-trimethylhexanoate, 3-hydrocarbyl-1, 1-dimethylbutyl neodecanoate, tert-amyl neodecanoate, bis (3-methylbenzoyl) peroxide, dibenzoyl peroxide, bis (4-methylbenzoyl) peroxide, tert-hexyl peroxyisopropyl monocarbonate, tert-butyl peroxymaleic acid, tert-butyl peroxy-3, 5-trimethylhexanoate, tert-butyl peroxylauric acid, 2, 5-dimethyl-2, 5-bis (3-methylbenzoyl) peroxy) hexane, organic peroxides such as t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoic acid, 2, 5-dimethyl-2, 5-di (benzoyl peroxide) hexane, t-butylperoxybenzoic acid, dibutyl peroxytrimethyl adipate, t-amyl peroxy n-octanoic acid, t-amyl peroxyisononanoate, and t-amyl peroxybenzoic acid; azo compounds such as 2,2 '-azobis-2, 4-dimethylvaleronitrile, 1' -azobis (1-acetoxy-1-phenylethane), 2 '-azobisisobutyronitrile, 2' -azobis (2-methylbutyronitrile), 4 '-azobis (4-cyanovaleryl), and 1,1' -azobis (1-cyclohexane carbonitrile).

The content of the component (C) may be 0.1 mass% or more, 0.5 mass% or more, or 1 mass% or more based on the total amount of binder components (components other than the conductive particles in the cured product of the light and thermosetting composition) from the viewpoint of excellent rapid curability and further improving the flow inhibition effect of the conductive particles and the peeling inhibition effect after transfer. From the viewpoint of pot life, the content of the component (C) may be 20 mass% or less, 10 mass% or less, or 5 mass% or less based on the total amount of binder components (components other than the conductive particles in the cured product of the light and thermosetting composition). The content of the component (C) based on the total amount of the components other than the conductive particles in the light and thermosetting composition may be the same as the above range, or the content of the component (C) based on the total amount of the components other than the conductive particles in the 1 st adhesive layer may be the same as the above range.

[ (D) component: conductive particles ]

The component (D) is not particularly limited as long as it is a particle having conductivity, and may be a metal particle composed of a metal such as Au, ag, ni, cu or solder, a conductive carbon particle composed of conductive carbon, or the like. (D) The component (c) may be coated conductive particles having a core made of non-conductive glass, ceramic, plastic (polystyrene, etc.), or a coating layer made of the metal or conductive carbon and covering the core. When using coated conductive particles having a core containing metal particles or plastic made of a heat-fusible metal and a coating layer containing metal or conductive carbon and coating the core, the cured product of the light and thermosetting composition is more easily deformed by heating or pressing. 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.

(D) The component (c) may be an insulating coated conductive particle including the metal particle, a conductive carbon particle, or a coated conductive particle, and an insulating layer containing an insulating material such as a resin and coating the surface of the particle. 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 occurrence of a short circuit due to contact between the components (D) can be suppressed, and the insulation between adjacent electrode circuits can be improved. (D) The component (c) may be used alone or in combination of 1 or more than 2 of the above-mentioned various conductive particles.

(D) The maximum particle size of the composition is preferably smaller than the minimum spacing of the electrodes (shortest distance between adjacent electrodes). The maximum particle diameter of the component (D) may be 1.0 μm or more, may be 2.0 μm or more, or may be 2.5 μm or more from the viewpoint of excellent dispersibility and conductivity. The maximum particle diameter 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 electrical conductivity. From these viewpoints, the maximum particle diameter of the component (D) may be 1.0 to 50. Mu.m, 2.0 to 30. Mu.m, or 2.5 to 20. Mu.m. In this specification, for any 300 (pcs) conductive particles, the particle diameter was measured by observation using a Scanning Electron Microscope (SEM), and the obtained maximum value was taken as the maximum particle diameter of the component (D). In addition, when the component (D) is not spherical due to the presence of a protrusion or the like, the particle diameter of the component (D) is the diameter of a circle circumscribed to the conductive particles in the SEM image.

The average particle diameter of the component (D) may be 1.0 μm or more, may be 2.0 μm or more, or may be 2.5 μm or more from the viewpoint of excellent dispersibility and conductivity. The average particle diameter 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 electrical conductivity. From these viewpoints, the average particle diameter of the component (D) may be 1.0 to 50. Mu.m, 2.0 to 30. Mu.m, or 2.5 to 20. Mu.m. In this specification, for any 300 (pcs) conductive particles, the particle size was measured by observation using a Scanning Electron Microscope (SEM), and the average value of the obtained particle sizes was taken as the average particle size.

In the 1 st adhesive layer 2, the (D) component may be uniformly dispersed. The particle density of the (D) component in the 1 st adhesive layer 2 may be 100pcs/mm from the viewpoint of easy obtaining of stable connection resistance ² The above can be 1000pcs/mm ² Above, 2000pcs/mm may also be used ² The above. The particle density of the (D) component in the 1 st adhesive layer 2 may be 100000pcs/mm from the viewpoint of improving the insulation between adjacent electrodes ² Hereinafter, the flow rate may be 50000pcs/mm ² Hereinafter, 10000pcs/mm may be used ² The following is given.

The content of the component (D) may be 5 mass% or more, 15 mass% or more, or 20 mass% or more based on the total mass of the light and the thermosetting composition, from the viewpoint of further improving the electrical conductivity. The content of the component (D) may be 50 mass% or less, 40 mass% or less, or 30 mass% or less based on the total mass of the light and the thermosetting composition, from the viewpoint of easy short circuit inhibition. From these viewpoints, the content of the component (D) may be 5 to 50 mass%, 10 to 40 mass%, or 20 to 30 mass% based on the total mass of the light and the thermosetting composition. The content of the component (D) based on the total mass of the cured product of the light and the thermosetting composition may be the same as the above range, or the content of the component (D) based on the total mass of the 1 st adhesive layer may be the same as the above range.

The content of the component (D) may be 0.1% by volume or more, 1% by volume or more, or 5% by volume or more based on the total volume of the cured product of the light-and heat-curable composition, from the viewpoint of further improving the electrical conductivity. The content of the component (D) may be 50% by volume or less, 30% by volume or less, or 20% by volume or less based on the total volume of the cured product of the light-and heat-curable composition, from the viewpoint of easy short circuit inhibition. The content of the component (D) based on the total volume of the light and the thermosetting composition may be the same as the above range, and the content of the component (D) based on the total volume of the 1 st adhesive layer may be the same as the above range.

[ (E) component: thiol Compound

(E) The component (a) is a compound having at least one thiol group. By using the component (E), both sufficient transferability and suppression of the flow of the conductive particles can be achieved.

The reason for obtaining the above-mentioned effects is not clear, but one of the reasons is presumed to be that the light and thermosetting composition can be cured to such an extent that the flow of the conductive particles can be suppressed without impairing the transferability, as a result of the light and thermosetting composition being rapidly and sufficiently cured by the action of the component (E) as the accelerator for the polymerization reaction of the component (a).

(E) The component (c) may be a monomer or an oligomer. The component (E) may be used alone or in combination of 1 or more. For example, as the component (E), a monomer and an oligomer may be used together.

(E) The component (c) may be a thiol compound having 1 thiol group (monofunctional thiol compound), or may be a thiol compound having a plurality of thiol groups (polyfunctional thiol compound). In particular, when the component (E) is a polyfunctional thiol compound, the component (E) functions as a crosslinking agent during curing ((A) component polymerization), and a crosslinked structure (-C-S-C-) derived from the component (E) is formed. Therefore, when a polyfunctional thiol compound is used as the component (E), a cured product having a high crosslinking density tends to be obtained, which has flexibility that does not interfere with transferability and further suppresses the flow of conductive particles. From the viewpoint of easy achievement of such effects, the number of alcohol groups may be 1 or more, 2 or more, or 4 or more. On the other hand, the number of thiol groups may be 12 or less or 10 or less from the viewpoint of facilitating more excellent transferability. From these viewpoints, the number of thiol groups may be 1 to 12, 2 to 10, or 4 to 10.

(E) The thiol group of the component may be a primary thiol group, a secondary thiol group, or a tertiary thiol group. The thiol group of the component (E) may be a secondary thiol group or a tertiary thiol group (a thiol group having a secondary or tertiary carbon atom as a bonded carbon atom) from the viewpoint of more excellent balance between transferability and suppression of flow of the conductive particles. (E) In the case where the component is a polyfunctional thiol compound, all thiol groups may be secondary thiol groups or tertiary thiol groups from the viewpoint of more excellent balance between transferability and suppression of flow of conductive particles.

Examples of the monofunctional thiol compound include 2-mercaptobenzothiazole, 2-methyl-4, 5-dihydrofuran-3-thiol, 3-mercapto-1-hexanol, mercaptomethylbutanol, 3-mercapto-2-methylpentanol, 3-mercapto-3-methylbutanol, 4-ethoxy-2-methyl-2-butanethiol, hexanethiol, isobutylthiol, 1-dimethylheptanethiol, 2-ethylhexyl-3-thiopropionate, n-octyl-3-thiopropionate, methoxybutyl-3-thiopropionate, stearyl-3-thiopropionate, and the like.

Examples of the polyfunctional thiol compound include pentaerythritol (3-mercaptobutyrate), ethanedithiol, 1, 3-butanedithiol, 1, 4-butanedithiol, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (3-mercaptobutyrate), tris- [ (3-mercaptopropionyloxy) -ethyl ] -isocyanate, tris- [ (3-mercaptobutyryloxy) -ethyl ] -isocyanate, tetraethyleneglycol-bis (3-mercaptopropionate), and 1, 4-bis (3-mercaptobutyryloxy) butane.

The component (E) may have a pentaerythritol skeleton represented by the following formula (2) from the viewpoint of further improving the flexibility of the cured product and easily obtaining more excellent transferability.

The component (E) having a pentaerythritol skeleton may be a compound represented by the following formula (3) from the viewpoint of more excellent balance between transferability and flow inhibition of conductive particles.

In the formula (3), R ²¹ 、R ²² 、R ²³ R is R ²⁴ Each independently represents an alkyl group which may be substituted by a thiol group. Wherein R is ²¹ 、R ²² 、R ²³ R is R ²⁴ At least one of them has a thiol group bonded to a carbon atom having 0, 1 or 2 hydrogen atoms bonded thereto. All R ²¹ 、R ²² 、R ²³ R is R ²⁴ May have thiol groups bonded to carbon atoms having a number of bonded hydrogen atoms of 0, 1 or 2. The number of carbon atoms of the alkyl group is, for example, 1 to 10. Specific examples of the alkyl group which may be substituted with a thiol group include a 2-mercaptoethyl group, a 2-mercaptopropyl group, a 2-mercapto-2-methyl-propyl group, a 3-mercaptobutyl group, and the like.

Specific examples of the compound represented by the formula (3) include pentaerythritol tetrakis (3-mercaptobutyrate).

The component (E) may be a compound represented by the following formula (4) from the viewpoint of further improving the flexibility of the cured product and easily obtaining more excellent transferability.

In formula (4), L represents a linking group. The linking group is, for example, a hydrocarbon group having a valence of 2, and is preferably an alkylene group (also referred to as an alkanediyl group). The number of carbon atoms of the 2-valent hydrocarbon group is, for example, 1 to 10, preferably 3 to 6. Specific examples of the 2-valent hydrocarbon group include ethylene, propylene, butylene, and hexylene.

In the formula (4), R ³¹ R is R ³² Each independently represents an alkyl group which may be substituted by a thiol group. Wherein R is ³¹ R is R ³² At least one of them has a thiol group bonded to a carbon atom having 0, 1 or 2 hydrogen atoms bonded thereto. R is R ³¹ R is R ³² Both may have thiol groups bonded to carbon atoms having a number of bonded hydrogen atoms of 0, 1 or 2. The number of carbon atoms of the alkyl group is, for example, 1 to 10. Specific examples of the alkyl group which may be substituted with a thiol group include a 2-mercaptoethyl group, a 2-mercaptopropyl group, a 2-mercapto-2-methyl-propyl group, a 3-mercaptobutyl group, and the like.

Specific examples of the compound represented by the formula (3) include tetraethyleneglycol-bis (3-mercaptopropionate) and 1, 4-bis (3-mercaptobutyryloxy) butane.

When the resin composition is used as a film-like adhesive, the molecular weight of the component (E) may be 150 or more, 200 or more or 250 or more from the viewpoint of suppressing volatilization in the drying step in the production process. The molecular weight of the component (E) may be 5000 or less, 3000 or less, or 1500 or less from the viewpoint of better compatibility with other components. From these viewpoints, the molecular weight of the component (E) may be 150 to 5000, 200 to 3000 or 250 to 1500.

The content of the component (E) may be 0.05 mass% or more, 0.5 mass% or more, 1.0 mass% or more, or 1.5 mass% or more based on the total amount of components other than the conductive particles in the light and thermosetting composition, from the viewpoint of further improving the flow inhibiting effect of the conductive particles. The content of the component (E) may be 5.0 mass% or less, 3.0 mass% or less, 2.5 mass% or less, or 2.0 mass% or less from the viewpoint of further improving the transferability and further improving the peeling-inhibiting effect after the high temperature and high humidity test. From these viewpoints, the content of the component (E) may be 0.05 to 5.0 mass%, 0.05 to 3.0 mass%, 0.5 to 2.0 mass%, 1.0 to 2.0 mass%, or 1.5 to 2.0 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition.

From the viewpoint of more excellent balance between transferability and flow inhibition of the conductive particles, the total mole number of thiol groups in the component (E) contained in the light and thermosetting composition may be 0.05 or more, 0.1 or more, or 0.15 or more, 0.5 or less, 0.4 or less, or 0.3 or less, or 0.05 to 0.5, 0.1 to 0.4, or 0.15 to 0.3, relative to the total mole number of polymerizable groups in the component (a) (e.g., the total mole number of (meth) acryloyloxy groups in the component (a)).

[ other Components ]

The light and heat curable composition may further contain other components than the above components. Examples of the other component include thermoplastic resins, coupling agents, and fillers. These may be contained in the 1 st adhesive layer 2.

Examples of the thermoplastic resin include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester polyurethane resin, and acrylate rubber. When the light and thermosetting composition contains a thermoplastic resin, the 1 st adhesive layer can be easily formed. Even when the photo-setting and thermosetting composition contains a thermoplastic resin, the stress of the 1 st adhesive layer generated when the photo-setting and thermosetting composition is cured can be relaxed. When the thermoplastic resin has a functional group such as a hydroxyl group, the adhesion of the 1 st adhesive layer is easily improved. From these viewpoints, a phenoxy resin can be used as the thermoplastic resin. The thermoplastic resin may be contained in an amount of 5 mass% or more, 80 mass% or less, or 5 to 80 mass% based on the total amount of components other than the conductive particles in the light and heat-curable composition.

Examples of the coupling agent include silane coupling agents having an organic functional group such as a (meth) acryloyl group, a mercapto group, an amino group, an imidazolyl group, and an epoxy group (e.g., 3- (meth) acryloxypropyl trimethoxysilane), silane compounds such as tetraalkoxysilane, tetraalkoxy titanate derivatives, and polydialkyl titanate derivatives. In the case where the light and thermosetting composition contains a coupling agent, the adhesion can be further improved. The content of the coupling agent may be 0.1 mass% or more and 20 mass% or less based on the total amount of components other than the conductive particles in the light and thermosetting composition. In the present specification, a silane coupling agent having a polymerizable group such as a (meth) acryloyloxy group is not included in the polymerizable compound.

Examples of the filler include a nonconductive filler (nonconductive particles, etc.). When the light and thermosetting composition contains a filler, further improvement in connection reliability can be expected. The filler may be any of an inorganic filler and an organic filler. Examples of the inorganic filler include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titania particles, and zirconia particles; inorganic particles such as nitride particles. Examples of the organic filler include organic particles such as silicone particles, methacrylate-butadiene-styrene particles, acrylic-silicone particles, polyamide particles, and polyimide particles. These particles may have a uniform structure or may have a core-shell structure. The maximum diameter of the filler material may be smaller than the minimum particle diameter of the conductive particles 4. The filler may be contained in an amount of 1% by volume or more, 30% by volume or less, or 1 to 30% by volume based on the total volume of the light and the thermosetting composition.

The light and heat curable composition may contain other additives such as softeners, accelerators, deterioration inhibitors, colorants, flame retardants, thixotropic agents, and the like. The content of these additives may be 0.1 to 10 mass% based on the total amount of components other than the conductive particles in the light and thermosetting composition. These additives may be contained in the 1 st adhesive layer 2.

The thickness d1 of the 1 st adhesive layer 2 may be 0.1 times or more, 0.2 times or more, or 0.3 times or more the average particle diameter of the conductive particles 4, from the viewpoint that the conductive particles 4 can be easily trapped between the opposing electrodes, and the connection resistance can be further reduced. The thickness d1 of the 1 st adhesive layer 2 may be 0.8 times or less or 0.7 times or less the average particle diameter of the conductive particles 4 from the viewpoint that the conductive particles are more likely to be crushed and the connection resistance can be further reduced when the conductive particles are sandwiched between the opposing electrodes at the time of thermocompression bonding. From these viewpoints, the thickness d1 of the 1 st adhesive layer 2 may be 0.1 to 0.8 times, 0.2 to 0.8 times, or 0.3 to 0.7 times the average particle diameter of the conductive particles 4. The thickness d1 of the 1 st adhesive layer 2 is the thickness of the 1 st adhesive layer located at the separated portion of the adjacent conductive particles 4, 4.

When the thickness d1 of the 1 st adhesive layer 2 and the average particle diameter of the conductive particles 4 satisfy the above relationship, as shown in fig. 1, a part of the conductive particles 4 in the 1 st adhesive layer 2 may protrude from the 1 st adhesive layer 2 to the 2 nd adhesive layer 3 side. In this case, the boundary S between the 1 st adhesive layer 2 and the 2 nd adhesive layer 3 is located at the separated portion of the adjacent conductive particles 4, 4. By providing the boundary S on the conductive particles (along the surface of the conductive particles), the conductive particles 4 in the 1 st adhesive layer 2 may not protrude from the 1 st adhesive layer 2 to the 2 nd adhesive layer 3 side, and the above-described relationship may be satisfied. The conductive particles 4 are not exposed on the surface 2a of the 1 st adhesive layer 2 opposite to the 2 nd adhesive layer 3 side, and the surface 2a on the opposite side may be a flat surface.

The relationship between the thickness d1 of the 1 st adhesive layer 2 and the maximum particle diameter of the conductive particles 4 may be the same as the relationship between the thickness d1 of the 1 st adhesive layer 2 and the average particle diameter of the conductive particles 4. The thickness d1 of the 1 st adhesive layer 2 may be 0.1 to 0.8 times, 0.2 to 0.8 times, or 0.3 to 0.7 times the maximum particle diameter of the conductive particles 4.

The thickness d1 of the 1 st adhesive layer 2 may be appropriately set according to the height of the electrode of the circuit member to be adhered, and the like. The thickness d1 of the 1 st adhesive layer 2 may be 0.5 μm or more or 20 μm or less. In addition, when a part of the conductive particles 4 is exposed from the surface of the 1 st adhesive layer 2 (for example, protrudes toward the 2 nd adhesive layer 3 side), the distance from the surface 2a on the opposite side from the 2 nd adhesive layer 3 side in the 1 st adhesive layer 2 to the boundary S between the 1 st adhesive layer 2 and the 2 nd adhesive layer 3 located at the separated portion of the adjacent conductive particles 4, 4 (the distance indicated by d1 in fig. 1) is the thickness of the 1 st adhesive layer 2, and the exposed portion of the conductive particles 4 (the portion not covered by the 1 st adhesive layer 2) is not included in the thickness of the 1 st adhesive layer 2. The length of the exposed portion of the conductive particle 4 may be 0.1 μm or more, 20 μm or less, or 0.1 to 20 μm.

The thickness of the adhesive layer can be measured by the following method. First, the adhesive film was sandwiched between 2 sheets of glass (thickness: about 1 mm). Next, injection molding was performed using a resin composition formed of 100g of bisphenol A type epoxy resin (product name: JER811, mitsubishi Chemical Corporation) and 10g of a curing agent (product name: EPOMUNT curing agent, manufactured by Refine Tec Ltd.). Thereafter, the thickness of each adhesive layer was measured by a scanning electron microscope (SEM, product name: SE-8020, manufactured by Hitachi High-Tech Science Corporation) while polishing the cross section by using a grinder.

(2 nd adhesive layer)

The 2 nd adhesive layer 3 contains, for example, a thermosetting composition containing (a) a polymerizable compound (hereinafter, also referred to as component (a)) and (b) a thermal polymerization initiator (hereinafter, also referred to as component (b)). The 2 nd adhesive layer 3 is composed of, for example, a thermosetting composition. The thermosetting composition constituting the 2 nd adhesive layer 3 is a thermosetting composition capable of flowing at the time of circuit connection, for example, an uncured thermosetting composition.

[ (a) component: polymerizable Compound

(a) The component (c) is a compound polymerized by, for example, radicals, cations or anions generated by a thermal polymerization initiator. As the component (a), a compound exemplified as the component (a) can be used. The component (a) may be a radical polymerizable compound having a radical polymerizable group by radical reaction, from the viewpoint of easy connection at a low temperature in a short time, further improved effect of reducing connection resistance, and more excellent connection reliability. Examples of the radical polymerizable compound and the combination thereof are the same as those of the component (A).

(a) The component may be any of monomers, oligomers or polymers. As the component (a), 1 kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination. (a) The component (A) may be the same as or different from the component (A).

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

[ (b) component: thermal polymerization initiator ]

As the component (b), a thermal polymerization initiator exemplified as the component (C) can be used. As the component (b), 1 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 from the viewpoint of further improving the effect of reducing the connection resistance and further improving the connection reliability. (b) Examples of the thermal radical polymerization initiator in the component (C) are the same as those in the component (C).

The content of the component (b) may be 0.1 mass% or more, 0.5 mass% or more, or 1 mass% or more based on the total mass of the thermosetting composition, from the viewpoint of further improving the effect of reducing the connection resistance and further improving the connection reliability. From the standpoint of pot life, based on the total mass of the thermosetting composition,

(b) The content of the component (c) may be 30 mass% or less, 20 mass% or less, or 10 mass% or less. From these viewpoints, the content of the component (b) may be 0.1 to 30 mass%, 0.5 to 20 mass%, or 1 to 10 mass% based on the total mass of the thermosetting composition.

[ other Components ]

The thermosetting composition may further contain other components than the component (a) and the component (b). Examples of the 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 those of the 1 st adhesive layer 2.

The 2 nd adhesive layer 3 (thermosetting composition) may not contain the photopolymerization initiator and the conductive particles 4. The content of the photopolymerization initiator in the 2 nd adhesive layer 3 may be 1 mass% or less, 0.1 mass% or less, or 0 mass% based on the total mass of the 2 nd adhesive layer 3. The content of the conductive particles 4 in the 2 nd adhesive layer 3 may be 1 mass% or less or 0 mass% based on the total mass of the 2 nd adhesive layer.

The thickness d2 of the 2 nd adhesive layer 3 may be appropriately set according to the height of the electrode of the circuit member to be bonded, and the like. The thickness d2 of the 2 nd adhesive layer 3 may be 5 μm or more, 200 μm or less, or 5 to 200 μm from the viewpoint of sufficiently filling the space between the electrodes to seal the electrodes, and obtaining more excellent connection reliability. In addition, when a part of the conductive particles 4 is exposed from the surface of the 1 st adhesive layer 2 (for example, protrudes toward the 2 nd adhesive layer 3), the distance from the surface 3a of the 2 nd adhesive layer 3 on the opposite side from the 1 st adhesive layer 2 side to the boundary S between the 1 st adhesive layer 2 and the 2 nd adhesive layer 3 located at the separated portion of the adjacent conductive particles 4, 4 (the distance indicated by d2 in fig. 1) is the thickness of the 2 nd adhesive layer 3.

From the viewpoint of sufficiently filling the space between the electrodes to seal the electrodes and obtaining more excellent reliability, the ratio of the thickness d1 of the 1 st adhesive layer 2 to the thickness d2 of the 2 nd adhesive layer 3 (the thickness d1 of the 1 st adhesive layer 2/the thickness d2 of the 2 nd adhesive layer 3) may be 1 or more, 100 or less, or 1 to 100.

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

In the adhesive film 1, the conductive particles 4 are dispersed in the 1 st adhesive layer 2. Thus, the adhesive film 1 is an anisotropically conductive adhesive film having anisotropically conductivity. The adhesive film 1 is interposed between a 1 st circuit member having a 1 st electrode and a 2 nd circuit member having a 2 nd electrode, and thermally presses the 1 st circuit member and the 2 nd circuit member so that the 1 st electrode and the 2 nd electrode are electrically connected to each other.

According to the adhesive film 1, the flow of conductive particles generated at the time of manufacturing the circuit connection structure can be suppressed. According to the adhesive film 1, peeling at the interface of the circuit member and the adhesive film 1 due to insufficient transferability can also be suppressed. According to the adhesive film 1, peeling at the interface between the circuit member and the circuit connecting portion, which occurs when the circuit connecting structure is used for a long period of time under a high-temperature and high-humidity environment, can be suppressed.

The adhesive film of the present embodiment has been described above, but the present invention is not limited to the above embodiment.

For example, the adhesive film for circuit connection may be composed of, for example, two layers of the 1 st adhesive layer and the 2 nd adhesive layer, or may be composed of three or more layers including layers other than the 1 st adhesive layer and the 2 nd adhesive layer (for example, the 3 rd adhesive layer). The 3 rd adhesive layer may have the same composition as the 1 st adhesive layer or the 2 nd adhesive layer, or may have the same thickness as the 1 st adhesive layer or the 2 nd adhesive layer.

The adhesive film for circuit connection of the above embodiment is an anisotropic conductive adhesive film having anisotropic conductivity, but the adhesive film for circuit connection may be a conductive adhesive film having no anisotropic conductivity.

Method for producing adhesive film for circuit connection

The method for producing the adhesive film 1 for circuit connection according to the present embodiment includes, for example: a preparation step (1 st preparation step) of preparing the 1 st adhesive layer 2; and a lamination step of laminating the 2 nd adhesive layer 3 on the 1 st adhesive layer 2. The method for producing the adhesive film 1 for circuit connection may further include a preparation step (preparation step 2) of preparing the 2 nd adhesive layer 3. The order of performing the 1 st preparation step and the 2 nd preparation step is not particularly limited, and the 1 st preparation step may be performed first, or the 2 nd preparation step may be performed first.

In the 1 st preparation step, for example, the 1 st adhesive layer 2 is prepared by forming the 1 st adhesive layer 2 on the substrate to obtain a 1 st 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 a solvent (organic solvent), and dissolved or dispersed by stirring, mixing, kneading, or the like, to prepare a varnish composition (varnish-like light and thermosetting composition). Thereafter, the varnish composition is applied to the substrate subjected to the release treatment using a blade coater, roll coater, applicator, comma coater, die coater, or the like, and then the solvent is volatilized by heating to form a layer containing the light and the thermosetting composition on the substrate. Subsequently, the layer containing the light and the thermosetting composition is irradiated with light to cure (photocure) the light and the thermosetting composition, thereby forming the 1 st adhesive layer 2 on the substrate (curing step). Thus, the 1 st adhesive film was obtained.

As the solvent used for preparing the varnish composition, a solvent having a property of being able to uniformly dissolve or disperse each component can be used. Examples of such solvents include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, and the like. These solvents can be used singly or in combination of 2 or more. The stirring and mixing in the preparation of the varnish composition and the mixing can be performed by using, for example, a stirrer, a grinder, a three-roll, a ball mill, a bead mill, and a homogenizing and dispersing machine.

The substrate is not particularly limited as long as it has heat resistance capable of withstanding the heating conditions at the time of volatilizing the solvent, and for example, a substrate (e.g., film) made of stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer, or the like can be used.

The heating conditions for evaporating the solvent from the varnish composition applied to the substrate may be conditions sufficient to evaporate the solvent. The heating condition may be 40 ℃ to 120 ℃ inclusive and 0.1 minutes to 10 minutes inclusive.

A portion of the solvent may not be removed and remain on the layer comprising the light and the thermosetting composition. The content of the solvent in the layer containing the light and the thermosetting composition may be 10 mass% or less based on the total mass of the layer containing the light and the thermosetting composition.

The irradiation of light in the curing step may be performed by using irradiation light (for example, ultraviolet light) in the range of 150 to 750 nm. The irradiation of light 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 may be 100mJ/cm based on the cumulative light amount of light having a wavelength of 365nm ² The above may be 200mJ/cm ² Above, 300mJ/cm may also be used ² The above. The light irradiation amount can be 10000mJ/cm based on the cumulative light amount of 365nm wavelength light ² Hereinafter, the ratio may be 5000mJ/cm ² May also be 3000mJ/cm ² The following is given.

In the 2 nd preparation step, the 2 nd adhesive layer 3 is prepared by forming the 2 nd adhesive layer 3 on the base material to obtain a 2 nd adhesive film in the same manner as in the 1 st preparation step except that the (a) component and the (b) component, and other components added as needed, and not performing light irradiation are used.

A part of the solvent may remain on the 2 nd adhesive layer 3 without being removed. The content of the solvent in the 2 nd adhesive layer 3 may be 10 mass% or less based on the total mass of the 2 nd adhesive layer 3.

In the lamination step, the 1 st adhesive film and the 2 nd adhesive film may be laminated to form the 2 nd adhesive layer 3 on the 1 st adhesive layer 2, or a varnish composition obtained by using the component (a) and the component (b) and other components added as needed may be applied to the 1 st adhesive layer 2 to volatilize a solvent, and the 2 nd adhesive layer 3 may be laminated to the 1 st adhesive layer 2.

Examples of the method for bonding the 1 st adhesive film and the 2 nd adhesive film include hot pressing, roll lamination, vacuum lamination, and the like. Lamination may be carried out at a temperature of 0 to 80 ℃.

Circuit connection structure and method for manufacturing the same

The circuit connection structure using the adhesive film 1 for circuit connection as a circuit connection material and a method for manufacturing the same will be described below.

Fig. 2 is a schematic cross-sectional view showing a circuit connection structure according to an embodiment. As shown in fig. 2, the circuit connection structure 10 includes: a 1 st circuit member 13 having a 1 st electrode 12 formed on the 1 st circuit substrate 11 and a main surface 11a of the 1 st circuit substrate 11; a 2 nd circuit member 16 having a 2 nd electrode 15 formed on the 2 nd circuit substrate 14 and the main surface 14a of the 2 nd circuit substrate 14; and a circuit connection portion 17 disposed between the 1 st circuit member 13 and the 2 nd circuit member 16 so that the 1 st electrode 12 and the 2 nd electrode 15 are electrically connected to each other.

The 1 st circuit member 13 and the 2 nd circuit member 16 may be the same as each other or may be different from each other. The 1 st circuit member 13 and the 2 nd 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 1 st circuit board 11 and the 2 nd circuit board 14 may be formed of an inorganic material such as a semiconductor, glass, or ceramic, an organic material such as polyimide, polycarbonate, or a composite material such as glass/epoxy. The 1 st electrode 12 and the 2 nd electrode 15 may be formed of gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, indium Tin Oxide (ITO), indium Zinc Oxide (IZO), indium Gallium Zinc Oxide (IGZO), or the like. The 1 st electrode 12 and the 2 nd electrode 15 may be circuit electrodes or bump electrodes. At least one of the 1 st electrode 12 and the 2 nd electrode 15 may be a bump electrode. In fig. 2, the 2 nd electrode 15 is a bump electrode.

The circuit connection portion 17 includes a cured product of the adhesive film 1. The circuit connection unit 17 includes, for example: the 1 st region 18, which is located on the 1 st circuit member 13 side in a direction in which the 1 st circuit member 13 and the 2 nd circuit member 16 face each other (hereinafter, referred to as "facing direction"), is formed of a cured product of a component other than the conductive particles 4 of the light and thermosetting composition; a 2 nd region 19 which is located on the 2 nd circuit member 16 side in the opposing direction and is formed of the thermosetting composition; and conductive particles 4 interposed at least between the 1 st electrode 12 and the 2 nd electrode 15 so that the 1 st electrode 12 and the 2 nd electrode 15 are electrically connected to each other. The circuit connection portion does not need to have 2 regions like the 1 st region 18 and the 2 nd region 19. The circuit connection portion may include a region where the cured product of the component other than the conductive particles 4 in the light and thermosetting composition and the cured product of the thermosetting composition are mixed.

The method for manufacturing the circuit connection structure 10 described above includes, for example: a step of preparing a 1 st circuit member 13 having a 1 st electrode 12, a 2 nd circuit member 16 having a 2 nd electrode 15, and a base material-provided adhesive film (base material-provided adhesive film for circuit connection) of preparing an adhesive film (adhesive film for circuit connection) 1 on a base material; a step of transferring (laminating) the adhesive film 1 from the base material to the surface of the 1 st circuit member 13 on which the 1 st electrode 12 is formed; and a step of arranging the 1 st circuit member 13, the adhesive film 1 and the 2 nd circuit member 16 in this order so that the 1 st electrode 12 and the 2 nd electrode 15 face each other, and thereafter thermally pressing the 1 st circuit member 13 and the 2 nd circuit member 16 to electrically connect the 1 st electrode 12 and the 2 nd electrode 15 to each other.

Specifically, first, a 1 st circuit member 13 having a 1 st electrode 12 formed on a 1 st circuit substrate 11 and a main surface 11a of the 1 st circuit substrate 11, a 2 nd circuit member 16 having a 2 nd electrode 15 formed on a 2 nd circuit substrate 14 and a main surface 14a of the 2 nd circuit substrate 14, and a base-provided adhesive film having an adhesive film 1 on a base material are prepared. The substrate of the adhesive film with a substrate may be a substrate for producing the adhesive film.

Next, the adhesive film 1 is transferred (laminated) from the base material onto the surface of the 1 st circuit member 13 on which the 1 st electrode 12 is formed. Specifically, for example, the 1 st adhesive layer 2 side is opposed to the main surface (mounting surface) 11a of the 1 st circuit member 13, and the adhesive film 1 is laminated on the 1 st circuit member 13.

The lamination method is not particularly limited, but a roll laminator, a diaphragm laminator, a vacuum roll laminator, and a vacuum diaphragm laminator can be used. After the temporary lamination, crimping may be performed using a thermocompression bonding device.

The lamination conditions may be appropriately set according to the type of laminator, substrate, 1 st circuit member 13, 2 nd circuit member 16, etc. used. The temperature at the time of lamination (pressure bonding temperature) may be 50 to 90 ℃. The pressure (pressure of press bonding) at the time of lamination may be 0.5 to 1.5MPa. The lamination time (press-bonding time) may be 0.5 to 1.5 seconds.

Next, as shown in fig. 3 (a), the 2 nd circuit member 16 is disposed on the 1 st circuit member 13 on which the adhesive film 1 is laminated so that the 1 st electrode 12 and the 2 nd electrode 15 face each other.

As shown in fig. 3 (b), the 1 st circuit member 13, the adhesive film 1, and the 2 nd circuit member 16 are heated, and the 1 st circuit member 13 and the 2 nd circuit member 16 are pressurized in the thickness direction, whereby the 1 st circuit member 13 and the 2 nd circuit member 16 are thermally pressed against each other. At this time, as shown by the arrow in fig. 3 (b), the 2 nd adhesive layer 3 contains a flowable uncured thermosetting composition, and is cured by the above-mentioned heating while flowing so as to fill the gap between the 2 nd electrodes 15, 15. Thus, the 1 st electrode 12 and the 2 nd electrode 15 are electrically connected to each other via the conductive particles 4, and the 1 st circuit member 13 and the 2 nd circuit member 16 are bonded to each other, whereby the circuit connection structure 10 shown in fig. 2 can be obtained. In the method for manufacturing the circuit connection structure 10 according to the present embodiment, since the 1 st adhesive layer 2 is a layer cured in advance, the conductive particles 4 hardly flow during the thermocompression bonding, and the conductive particles are efficiently trapped between the opposing electrodes, so that the connection resistance between the opposing electrodes (between the 1 st electrode 12 and the 2 nd electrode 15) can be reduced. Thus, a circuit connection structure excellent in connection reliability can be obtained.

The temperature and time at the time of thermocompression bonding may be any temperature at which the adhesive film 1 is sufficiently cured and the 1 st circuit component 13 and the 2 nd circuit component 16 can be bonded. The thermocompression bonding temperature may be 150 to 200 ℃. The thermocompression bonding time may be 4 to 7 seconds.

Examples

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

< Synthesis of polyurethane acrylate (UA 1) >)

To a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser having a zirconium chloride drying tube, and a nitrogen inlet tube, 2500 parts by mass (2.50 mol) of poly (1, 6-hexanediol carbonate) (product name: DURANATE T5652, manufactured by ASAHI KASEI CORPORATION, number average molecular weight 1000) and 666 parts by mass (3.00 mol) of isophorone diisocyanate (manufactured by Sigma-Aldrich Co.LLC) were uniformly dropped over 3 hours. Next, after sufficiently introducing nitrogen gas into the reaction vessel, the reaction vessel was heated to 70 to 75℃to react the nitrogen gas. Subsequently, 0.53 parts by mass (4.3 mmol) of hydroquinone monomethyl ether (manufactured by Sigma-Aldrich Co.LLC) and 5.53 parts by mass (8.8 mmol) of dibutyltin dilaurate (manufactured by Sigma-Aldrich Co.LLC) were added to the reaction vessel, 238 parts by mass (2.05 mol) of 2-hydroxyethyl acrylate (manufactured by Sigma-Aldrich Co.LLC) was added thereto, and the mixture was reacted under an air atmosphere at 70℃for 6 hours. Thus, a polyurethane acrylate (UA 1) was obtained. The weight average molecular weight of the polyurethane acrylate (UA 1) was 15000. In addition, the weight average molecular weight was measured by Gel Permeation Chromatography (GPC) and using a calibration curve based on standard polystyrene according to the following conditions.

(measurement conditions)

The device comprises: TOSOH CORPORATION GPC-8020

A detector: TOSOH CORPORATION RI-8020

Chromatographic column: hitachi Chemical Company Gelpack GLA160S+GLA150S, ltd

Sample concentration: 120mg/3mL

Solvent: tetrahydrofuran (THF)

Injection amount: 60 mu L

Pressure: 2.94×10 ⁶ Pa(30kgf/cm ² )

Flow rate: 1.00mL/min

< preparation of conductive particles >)

On the surface of the polystyrene particles, a layer formed of nickel was formed so that the thickness of the layer became 0.2 μm. Thus, conductive particles having an average particle diameter of 4 μm, a maximum particle diameter of 4.5 μm and a specific gravity of 2.5 were obtained.

Preparation method of polyester polyurethane resin

48 parts by mass of isophthalic acid and 37 parts by mass of neopentyl glycol were charged into a stainless steel autoclave equipped with a stirrer, a thermometer, a capacitor, a vacuum generator and a nitrogen inlet tube and 0.02 part by mass of tetrabutoxytitanate as a catalyst was charged. Next, the temperature was raised to 220℃under a nitrogen stream, and the mixture was stirred directly for 8 hours. Thereafter, the pressure was reduced to atmospheric pressure (760 mmHg), and cooled to room temperature. Thereby, a white precipitate was precipitated. Next, the white precipitate was taken out, washed with water, and then vacuum-dried, whereby a polyester polyol was obtained. The obtained polyester polyol was sufficiently dried, dissolved in MEK (methyl ethyl ketone), and put into a four-necked flask equipped with a stirrer, a dropping funnel, a reflux cooler, and a nitrogen inlet tube. The target polyester polyurethane resin was obtained by charging dibutyltin dilaurate as a catalyst in an amount of 0.05 parts by mass per 100 parts by mass of the polyester polyol, dissolving 4,4' -diphenylmethane diisocyanate in an amount of 50 parts by mass per 100 parts by mass of the polyester polyol in MEK and charging with a dropping funnel, and stirring at 80 ℃ for 4 hours.

< preparation of varnish composition 1 (varnish-like light and thermosetting composition)

The following components were mixed in the blending amounts (parts by mass) shown in table 1 to prepare varnish compositions 1 to 9. The "content of thiol compound" shown in table 1 is a content based on the total amount of the conductive particles and the components other than the solvent in the varnish composition.

[ polymerizable Compound ]

A1: diacrylates having a tricyclodecane skeleton (product name: DCP-A, KYOEISHA CHEMICAL Co., LTD.)

A2: polyurethane acrylate (UA 1) synthesized as described above

A3: 2-Methacryloxyethyl acid phosphate (product name: LIGHT ESTER P-2M, KYOEISHA CHEMICAL Co., LTD.)

[ photopolymerization initiator ]

B1:1, 2-octanedione, 1- [4- (phenylthio) phenyl-, 2- (o-benzoyloxime) ] (product name: irgacure (registered trademark) OXE01, manufactured by BASF corporation)

[ thermal polymerization initiator ]

C1: benzoyl peroxide (product name: NYPER BMT-K40, manufactured by NOF CORPORATION)

[ conductive particles ]

D1: conductive particles produced as described above

[ thiol Compound ]

E1 pentaerythritol tetrakis (3-mercaptobutyrate) (product name: karenz MTPE1 ("Karenz MT" is a registered trademark. The same applies hereinafter), showa Denko K.K.)

E2:1, 4-bis (3-mercaptobutyryloxy) butane (product name: karenz MTBD1, manufactured by Showa Denko K.K.)

[ thermoplastic resin ]

F1: phenoxy resin (product name: PKHC, manufactured by Union Carbide Corporation)

(coupling agent)

G1: 3-methacryloxypropyl trimethoxysilane (product name: KBM503, shin-Etsu Chemical Co., ltd.)

[ filling Material ]

H1: silica fine particles (product name: R104, NIPPON AEROSIL CO., LTD. Average particle diameter (primary particle diameter): 12 nm)

[ solvent ]

I1: methyl ethyl ketone [ Table 1]

< preparation of varnish composition (varnish-like thermosetting composition) >)

As the polymerizable compounds A1 to A3, the thermal polymerization initiator b1, the coupling agent d1, the filler e1 and the solvent f1, the same materials as the polymerizable compounds A1 to A3, the thermal polymerization initiator C1, the coupling agent G1, the filler H1 and the solvent I1 in the photo-and thermosetting composition were used, and the thermoplastic resin C1 was prepared by mixing these components in the blending amounts (parts by mass) shown in table 2 using the following components.

(thermoplastic resin)

c1: polyester polyurethane resin synthesized as described above

TABLE 2

Example 1 >

[ production of the 1 st adhesive film ]

The 1 st varnish composition 1 was coated on a PET film having a thickness of 50. Mu.m, using a coating apparatus. Subsequently, the PET film was dried with hot air at 70℃for 3 minutes to form a layer of the light-and-thermosetting composition having a thickness (thickness after drying) of 4. Mu.m. The thickness here was measured using a contact thickness gauge. Next, the layer formed of the light and the thermosetting composition was irradiated with light using a metal halide lamp so that the cumulative light amount became 1500mJ/cm ² And polymerizing the polymerizable compound. Thus, the light and thermosetting composition was cured to form the 1 st adhesive layer. By the above operation, a 1 st adhesive film having a 1 st adhesive layer (thickness of a region where conductive particles exist: 4 μm) on a PET film was obtained. The density of the conductive particles at this time was about 7000pcs/mm ² . In addition, when the thickness of the 1 st adhesive layer is smaller than the thickness (diameter) of the conductive particles, the layer is measured using a contact thickness gaugeWhen the thickness is measured, the thickness of the conductive particles is reflected, and the thickness of the region where the conductive particles exist is measured. Therefore, after the adhesive film for circuit connection having a two-layer structure in which the 1 st adhesive layer and the 2 nd adhesive layer are laminated was produced, the thickness of the 1 st adhesive layer located in the separated portion of the adjacent conductive particles was measured by a method described later.

[ production of the 2 nd adhesive film ]

The 2 nd varnish composition 1 was coated on a PET film having a thickness of 50. Mu.m, using a coating apparatus. Subsequently, hot air drying was performed at 70℃for 3 minutes, and a 2 nd adhesive layer (layer formed of a thermosetting composition) having a thickness of 8 μm was formed on the PET film. By the above operation, the 2 nd adhesive film having the 2 nd adhesive layer on the PET film was obtained.

[ production of adhesive film for Circuit connection ]

The 1 st adhesive film and the 2 nd adhesive film are disposed so that the adhesive layers face each other, and laminated by a roll laminator while being heated at 40 ℃ together with the PET film as a base material. Thus, a circuit-connecting adhesive film with PET film having a circuit-connecting adhesive film with a two-layer structure in which the 1 st adhesive layer and the 2 nd adhesive layer are laminated was produced.

The thickness of the 1 st adhesive layer of the produced adhesive film for circuit connection was measured by the following method. First, an adhesive film for circuit connection was sandwiched between 2 sheets of glass (thickness: about 1 mm), and injection-molded using a resin composition comprising 100g of bisphenol A type epoxy resin (product name: JER, manufactured by Mitsubishi Chemical Corporation) and 10g of curing agent (product name: EPOMUNT curing agent, manufactured by Refine Tec Ltd.). Thereafter, cross-sectional polishing was performed using a grinder, and the thickness of the 1 st adhesive layer located in the separated portion of the adjacent conductive particles was measured by a scanning electron microscope (SEM, product name: SE-8020, manufactured by Hitachi High-Tech Science Corporation). The thickness of the 1 st adhesive layer was 2. Mu.m.

[ evaluation of transferability ]

The glass substrate was provided with a layer made of amorphous Indium Tin Oxide (ITO)) The thin film electrode (height:) Is produced by Geomatec Co., ltd.). Next, the PET film on the 1 st adhesive layer side of the PET film-attached adhesive film for circuit connection obtained as described above was peeled off, and the adhesive film for circuit connection was transferred onto the glass substrate with the film electrode. Specifically, the surface of the 1 st adhesive layer side of the adhesive film for circuit connection was bonded to the surface of the film electrode side of the glass substrate with the film electrode by a width of 1mm by using a thermocompression bonding apparatus (heating system: constant heat type, manufactured by TAIYO KIKAI Ltd) and heating and pressurizing at 80 ℃ under 1MPa for 1 second. Then, the PET film on the 2 nd adhesive layer side was peeled off, and the interface between the glass substrate and the circuit-connecting adhesive film was observed from the glass substrate side by a microscope, whereby the transfer state of the circuit-connecting adhesive film to the glass substrate was evaluated in 3 steps. The ratio of peeling from the glass substrate in the entire area of the adhesive film for circuit connection was determined, and the ratio of substantially no peeling (the ratio of peeled portions is less than 5% of the entire area) was a, the ratio of a small amount of peeling (the ratio of peeled portions is 5% or more and less than 20% of the entire area) was B, and the ratio of peeling (the ratio of peeled portions is 20% or more of the entire area) was C. The results are shown in Table 3.

[ production of Circuit connection Structure ]

COF (flexseedco., ltd.) having a pitch of 25 μm and a thin film electrode (height:) Is manufactured by GEOMATEC co., ltd.) using a thermocompression bonding apparatus (heating system: constant heat type, TAIYO KIKAI Ltd.) was heated and pressurized at 170℃under 6MPa for 4 seconds, and connected with each other at a width of 1mm, to produce a circuit connection structure (connection structure). In addition, when connecting, so that the adhesive film for circuit connectionThe 1 st adhesive layer side surface of the above is laminated on the glass substrate with the circuit connecting adhesive film facing the glass substrate. The laminate was subjected to lamination using a thermocompression bonding apparatus (heating method: constant heat type, manufactured by TAIYO KIKAI Ltd) at 80℃under 1MPa for 1 second.

[ evaluation of particle flowability ]

The obtained circuit connection structure was evaluated for the particle flow state of the resin oozed portion of the adhesive film for circuit connection by using a microscope (product name: ECLIPSE L200, manufactured by Nikon Corporation). Specifically, the produced circuit connection structure was observed from the glass substrate side by a microscope, and the particle state of the portion oozing outside the width of the adhesive film for circuit connection was evaluated in 3 steps. The result is shown in table 3, in which the state where particles are not substantially moved and particles are not present in the exuded portion is 1, the state where particles are not found to be connected to each other is 2, the state where particles are flowed and particles are found to be connected to each other is 3.

[ peeling evaluation ]

Using a microscope (product name: ECLIPSE L200, manufactured by Nikon Corporation), whether or not the circuit connection portion of the circuit connection structure was peeled off after the high temperature and high humidity test was evaluated. Specifically, first, the circuit connection structure fabricated as described above was placed in a constant temperature and humidity tank at 85 ℃ and 85% rh for 200 hours, and then subjected to a high temperature and high humidity test. Next, from the glass substrate side, the circuit connection portion of the circuit connection structure after the high temperature and high humidity test was observed by a microscope, and the peeled state at the interface of the glass substrate and the adhesive film for circuit connection was evaluated in 3 stages. The ratio of peeling from the glass substrate in the entire area of the adhesive film for circuit connection was determined, and the ratio of substantially no peeling (the ratio of peeled portions is less than 5% of the entire area) was a, the ratio of a small amount of peeling (the ratio of peeled portions is 5% or more and less than 20% of the entire area) was B, and the ratio of peeling (the ratio of peeled portions is 20% or more of the entire area) was C. The results are shown in Table 3.

Examples 2 to 7 and comparative examples 1 to 2

In the same manner as in example 1 except that the 1 st varnish compositions 2 to 9 were used in place of the 1 st varnish composition 1, the production of the adhesive film for circuit connection and the circuit connection structure, the transfer property evaluation, the particle flowability evaluation, and the peeling evaluation were performed. The results are shown in Table 3.

TABLE 3

Symbol description

1-adhesive film for circuit connection, 2-1 st adhesive layer, 3-2 nd adhesive layer, 4-conductive particles, 10-circuit connection structure, 12-circuit electrode (1 st electrode), 13-1 st circuit member, 15-bump electrode (2 nd electrode), 16-2 nd circuit member.

Claims

1. An adhesive film for circuit connection, comprising:

a 1 st adhesive layer; a kind of electronic device with high-pressure air-conditioning system

A 2 nd adhesive layer laminated on the 1 st adhesive layer,

the 1 st adhesive layer comprises a cured product of a light-curable composition,

the 2 nd adhesive layer comprises a thermosetting composition,

the photo-and thermosetting composition contains a polymerizable compound, a photopolymerization initiator, a thermal polymerization initiator, conductive particles, and a thiol compound.

2. The adhesive film for circuit connection according to claim 1, wherein,

the polymerizable compound includes a radical polymerizable compound.

3. The adhesive film for circuit connection according to claim 2, wherein,

the radically polymerizable compound includes a (meth) acrylate compound.

4. The adhesive film for circuit connection according to any one of claim 1 to 3, wherein,

5. The adhesive film for circuit connection according to any one of claims 1 to 4, wherein,

the thermosetting composition comprises a free radical polymerizable compound.

6. The adhesive film for circuit connection according to any one of claims 1 to 5, wherein,

7. A method for producing the adhesive film for circuit connection according to any one of claims 1 to 6, comprising:

and (2) a step of forming the 1 st adhesive layer by irradiating the layer containing the light and the thermosetting composition with light to cure the light and the thermosetting composition.

8. A method for manufacturing a circuit connection structure includes:

a step of preparing a 1 st circuit member having a 1 st electrode, a 2 nd circuit member having a 2 nd electrode, and a base material-provided adhesive film having the adhesive film for circuit connection according to any one of claims 1 to 6 on a base material;

a step of transferring the circuit-connecting adhesive film from the base material to a surface of the 1 st circuit member on which the 1 st electrode is formed; a kind of electronic device with high-pressure air-conditioning system

And a step of thermally bonding the 1 st circuit member and the 2 nd circuit member to electrically connect the 1 st electrode and the 2 nd electrode after sequentially disposing the 1 st circuit member, the adhesive film for circuit connection, and the 2 nd circuit member so that the 1 st electrode and the 2 nd electrode face each other.