Adhesive composition, adhesive film for circuit connection, connection structure, and method for manufacturing the connection structure.

Abstract

To provide an adhesive composition that can produce an adhesive film for circuit connections having superior properties compared to conventional adhesives. [Solution] An adhesive composition containing a cationic polymerizable compound and a curing agent, wherein the curing agent is a salt of a nitrogen-containing cation and an anion represented by the following general formula (1). TIFF2026148813000010.tif15149 [In formula (1), R 1 [where m represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, m represents 0 or 1, and n represents an integer from 1 to 4.]

Description

[Technical Field]

[0001] This disclosure relates to a curing agent, an adhesive composition, an adhesive film for circuit connection (anisotropic conductive adhesive film or conductive adhesive film), a connection structure, and a method for manufacturing the connection structure. [Background technology]

[0002] Conventionally, adhesive films have been used to electrically connect electrodes in the direction of pressure by heating and pressurizing opposing circuit components. As such adhesive films for circuit connection applications, for example, adhesive films for circuit connection in which conductive particles are dispersed in the adhesive are known (see, for example, Patent Documents 1 to 4 below). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 60-191228 [Patent Document 2] Japanese Patent Application Publication No. 1-251787 [Patent Document 3] Japanese Patent Application Publication No. 7-90237 [Patent Document 4] Japanese Patent Publication No. 2019-104869 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In recent years, the market has been demanding increasingly higher levels of reliability in fields such as semiconductors and liquid crystal displays. Consequently, there is a growing need for superior properties in adhesive films used for fixing electronic components and connecting circuits.

[0005] An object of the present disclosure is to provide an adhesive composition capable of obtaining an adhesive film for circuit connection having properties superior to those of conventional products. Another object of the present disclosure is to provide an adhesive film for circuit connection, a connection structure, and a method for producing the connection structure using the adhesive composition.

Means for Solving the Problems

[0006] The present disclosure includes the following [1] to

[18] . [1] An adhesive composition comprising a cationically polymerizable compound and a curing agent, wherein the curing agent is a salt of a nitrogen-containing cation and an anion represented by the following general formula (1).

Chemical Formula

[10] An adhesive composition according to any one of [1] to [9], wherein the reaction rate when heat-treated at 40°C for 15 hours is 10% or less.

[11] An adhesive composition according to any one of [1] to

[10] , wherein the elastic modulus of the reactant obtained by heating at 180°C for 1 hour is 0.100 GPa or more at a measurement temperature of 300°C. A circuit connection adhesive film comprising an adhesive layer formed by any one of the adhesive compositions described in

[12] [1] to

[11] . A circuit connection adhesive film comprising an adhesive layer formed by the adhesive composition described in

[13] [4] or [5], wherein the conductive particles are arranged in a predetermined pattern in a plan view of the circuit connection adhesive film.

[14] A circuit connection adhesive film comprising a first adhesive layer and a second adhesive layer laminated on the first adhesive layer, wherein at least one of the first adhesive layer and the second adhesive layer is a layer formed of the adhesive composition described in any one of [1] to

[11] .

[15] A connection structure comprising: a first circuit member having a first electrode; a second circuit member having a second electrode; and a connecting portion disposed between the first circuit member and the second circuit member for electrically connecting the first electrode and the second electrode, wherein the connecting portion includes a cured product of a circuit connection adhesive film according to any one of

[12] to

[14] .

[16] A method for manufacturing a connection structure, comprising the steps of interposing a circuit connection adhesive film according to any one of

[12] to

[14] between a first circuit member having a first electrode and a second circuit member having a second electrode, and then heat-pressing the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other. [Effects of the Invention]

[0007] This disclosure provides an adhesive composition that can produce an adhesive film for circuit connections having superior properties compared to conventional adhesives. Furthermore, this disclosure provides an adhesive film for circuit connections using the adhesive composition, a connection structure, and a method for manufacturing the connection structure. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connections. [Figure 2] This is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connections. [Figure 3] This is a schematic cross-sectional view showing one embodiment of the connecting structure. [Figure 4] This is a schematic cross-sectional view showing the manufacturing method of the connecting structure shown in Figure 3. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the embodiments described below.

[0010] In the numerical ranges described herein, the upper or lower limits of the range may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range may be arbitrarily combined with the lower or upper limits of other numerical ranges. In the notation "A~B" for a numerical range, the numbers A and B at both ends are included in the range as the lower and upper limits, respectively. In this specification, for example, "10 or more" means 10 and numbers greater than 10, and this applies even if the numbers are different. Similarly, for example, "10 or less" means 10 and numbers less than 10, and this applies even if the numbers are different. Also, unless otherwise specified, each component and material exemplified herein may be used alone or in combination of two or more. In this specification, the content of each component in a composition means the total amount of multiple substances present in the composition, unless otherwise specified, when multiple substances corresponding to each component exist in the composition. Furthermore, in this specification, "(meth)acrylate" means at least one of acrylate and the corresponding methacrylate.

[0011] <Adhesive composition> One embodiment of the present disclosure is an adhesive composition containing a cationic polymerizable compound and a curing agent, wherein the curing agent is a salt of a nitrogen-containing cation and an anion represented by the following general formula (1). Hereinafter, the curing agent which is a salt of a nitrogen-containing cation and an anion represented by the following general formula (1) will be referred to as curing agent A. According to the adhesive composition of one embodiment, an adhesive film for circuit connections having superior properties (e.g., corrosion resistance, heat resistance) compared to conventional adhesives can be obtained. [ka] [In formula (1), R 1 [where m represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, m represents 0 or 1, and n represents an integer from 1 to 4]

[0012] [Cationically polymerizable compounds] The cationic polymerizable compound may be, for example, a compound that crosslinks when heated in response to curing agent A. Examples of cationic polymerizable compounds include epoxy compounds, vinyl ether compounds, and oxetane compounds. The cationic polymerizable compound may contain epoxy compounds. The cationic polymerizable compound may be used alone or in combination of two or more. The cationic polymerizable compound does not have to contain vinyl ether compounds. The cationic polymerizable compound does not have to contain oxetane compounds.

[0013] Examples of epoxy compounds include bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, tetramethylbisphenol A type epoxy resin, 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (bi-7-oxabicyclo[4,1,0]heptane), 3,4-epoxycyclohexylmethyl (meth)acrylate, (3,3',4,4'-diepoxy)bicyclohexyl, dicyclopentadiene dimethanol diglycidyl ether, xylene novolac type glycidyl ether, and biphenyl type epoxy resin. The epoxy compound may contain at least one selected from the group consisting of bisphenol A type epoxy resin, tetramethylbisphenol A type epoxy resin, dicyclopentadiene dimethanol diglycidyl ether, xylene-novolac type glycidyl ether, and alicyclic epoxy resin. The epoxy compound may also contain a glycidyl ether compound. The epoxy compound may also contain an alicyclic epoxy resin from the viewpoint of achieving better low-temperature curability, storage stability, and connection resistance. The epoxy compound does not have to contain an alicyclic epoxy resin.

[0014] The epoxy compound may be a polyfunctional epoxy resin, from the viewpoint of achieving better low-temperature curing properties, storage stability, and connection resistance. The number of epoxy groups in the epoxy compound may be 1 or more, 2 or more, or 3 or more, and may be 15 or less, 12 or less, or 10 or less.

[0015] The epoxy equivalent of the epoxy compound may be 100-300 g / eq or 150-250 g / eq, from the viewpoint of achieving better low-temperature curing properties, storage stability, and connection resistance. The epoxy equivalent refers to the value measured in accordance with JIS K7236.

[0016] As an oxetane compound, any compound having one or more oxetane ring structures in its molecule can be used without particular restriction. The cationic polymerizable compound may contain an oxetane compound from the viewpoint of achieving better low-temperature curability, storage stability, and connection resistance. The cationic polymerizable compound may contain only one of the epoxy compound and the oxetane compound from the viewpoint of achieving better low-temperature curability, storage stability, and connection resistance. Cases in which only one of the epoxy compound and the oxetane compound is included when one selected from the epoxy compound and the oxetane compound is used alone as the cationic polymerizable compound, and when one selected from the epoxy compound and the oxetane compound is used in combination with a cationic polymerizable compound such as a vinyl ether compound. The cationic polymerizable compound may contain an epoxy compound and an oxetane compound.

[0017] From the viewpoint of ensuring the curability of the adhesive composition, the content of the cationic polymerizable compound may be 10% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more, based on the total mass of the adhesive composition. From the viewpoint of ensuring the formation properties of the adhesive composition, the content of the cationic polymerizable compound may be 70% by mass or less, 65% by mass or less, or 50% by mass or less, based on the total mass of the adhesive composition. From these viewpoints, the content of the cationic polymerizable compound may be 10 to 70% by mass, based on the total mass of the adhesive composition.

[0018] The epoxy compound content in the cationic polymerizable compound may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more, and may also be 100% by mass or less, 95% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0019] The content of the oxetane compound in the cationic polymerizable compound may be 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more, and may be 100% by mass or less, 95% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0020] [Hardening agent A] The curing agent A is a salt of a nitrogen-containing cation and an anion represented by the following general formula (1). By containing curing agent A in the adhesive composition, it is possible to obtain a circuit connection adhesive film with superior properties (e.g., corrosion resistance, heat resistance) compared to conventional adhesives using the adhesive composition. [ka] [In formula (1), R 1 [where m represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, m represents 0 or 1, and n represents an integer from 1 to 4.]

[0021] In formula (1), the fluoroalkyl group may be a perfluoroalkyl group, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance. The number of carbon atoms in the fluoroalkyl group may be 5 or less, 4 or less, 3 or less, or 2 or less, or 1 or more, or 2 or more, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0022] In formula (1), examples of the aryl group in the fluoroaryl group include phenyl groups and naphthyl groups. The fluoroaryl group may also be a perfluoroaryl group, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0023] In formula (1), the fluoroalkyl-substituted aryl group is an aryl group having a fluoroalkyl group. The fluoroalkyl-substituted aryl group may also be a perfluoroalkyl-substituted aryl group, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0024] The number of carbon atoms in the alkyl group of a fluoroalkyl-substituted aryl group may be 5 or less, 4 or less, or 3 or less, or 1 or more, or 2 or more. The aryl group in a fluoroalkyl-substituted aryl group may be a phenyl group or a naphthyl group. The number of fluoroalkyl groups in a fluoroalkyl-substituted aryl group may be 5 or less, 4 or less, 3 or less, or 2 or less, or 1 or more, or 2 or more, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0025] In formula (1), n ​​may be 2 to 4, 3 to 4, or 4, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0026] Anions represented by formula (1) include tetrafluorogallium anion, tetrakis(pentafluorophenyl)gallium anion, tetrakis[fluorophenyl]gallium anion such as tetrakis(4-fluorophenyl)gallium anion, tetrakis[difluorophenyl]gallium anion such as tetrakis(3,5-difluorophenyl)gallium anion, tris(pentafluorophenyl)fluorogallium anion, bis(pentafluorophenyl)difluorogallium anion, (pentafluorophenyl)trifluorogallium anion, tetrakis(fluoroalkylphenyl)gallium anion such as tetrakis[4-(trifluoromethyl)phenyl]gallium anion, tetrakis[bis(fluoroalkyl)phenyl]gallium anion such as tetrakis[3,5-bis(trifluoromethyl)phenyl]gallium anion, and tris[4-(trifluoromethyl)phenyl] Examples include tris(fluoroalkyl)phenyl]fluorogallium acid anions such as ologalium acid anions; tris[bis(fluoroalkyl)phenyl]fluorogallium acid anions such as tris[3,5-bis(trifluoromethyl)phenyl]fluorogallium acid anions; bis[(fluoroalkyl)phenyl]difluorogallium acid anions such as bis[4-(trifluoromethyl)phenyl]difluorogallium acid anions; bis[bis(fluoroalkyl)phenyl]difluorodifluorogallium acid anions such as bis[3,5-bis(trifluoromethyl)phenyl]difluorogallium acid anions; [(fluoroalkyl)phenyl]trifluorogallium acid anions such as [4-(trifluoromethyl)phenyl]trifluorogallium acid anions; and [bis(fluoroalkyl)phenyl]trifluorogallium acid anions such as [3,5-bis(trifluoromethyl)phenyl]trifluorogallium acid anions. The anion represented by formula (1) may also be a tetrakis(pentafluorophenyl)gallium acid anion, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0027] The nitrogen-containing cation may be, for example, an ammonium cation, anilinium cation, or pyridinium cation. The nitrogen-containing cation may also be anilinium cation, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0028] The nitrogen-containing cation may be, for example, a cation represented by the following general formula (2). [ka] [In formula (2), R 21 , R 22 , and R 23 Each of these independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a substituted or unsubstituted heterocyclic group.

[0029] Examples of alkyl groups in formula (2) include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, n-pentyl, n-hexyl, n-heptyl, and aralkyl groups. Examples of aralkyl groups include phenylmethyl, phenylethyl, naphthylmethyl, and cinnamyl groups. These alkyl groups may have substituents.

[0030] Examples of aryl groups in formula (2) include phenyl groups, naphthyl groups, and biphenyl groups. These aryl groups may have substituents.

[0031] Examples of alkenyl groups in formula (2) include propenyl, 2-butenyl, 2-pentanyl, and 2-hexanyl groups. These alkenyl groups may have substituents.

[0032] In formula (2), examples of the alkoxyl group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and the like. These alkoxyl groups may have a substituent.

[0033] In formula (2), examples of the aryloxy group include a 4-phenylmethoxy group, a 4-phenylethoxy group, a 4-phenyloxycarbonylmethyl group, and the like. These aryloxy groups may have a substituent.

[0034] In formula (2), examples of the heterocyclic group include a pyridinyl group, a 4-cyclohexane oxide group, and the like. These heterocyclic groups may have a substituent.

[0035] Examples of the substituent in the alkyl group or the like of formula (2) include: alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a hexyl group; aryl groups such as a phenyl group and a naphthyl group; alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group; acyloxy groups such as an acetoxy group, a propionyloxy group, a decylcarbonyloxy group, and a dodecylcarbonyloxy group; alkoxycarbonyl groups such as a methoxycarbonyl group, an ethoxycarbonyl group, and a benzoyloxy group; a phenylthio group; halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a cyano group; a nitro group; and a hydroxy group.

[0036] In formula (2), the benzene ring bonded to the nitrogen atom may or may not have a substituent.

[0037] From the viewpoint of achieving more excellent low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance, R 21 , R 22 , and R 23 may each independently be a substituted or unsubstituted alkyl group, and at least one of R 21 , R 22 , and R 23 may be an aralkyl group.

[0038] A nitrogen-containing cation is a cation containing at least one nitrogen atom. From the viewpoint of achieving superior low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance, the nitrogen-containing cation may also be a cation represented by the following general formula (3). [ka] [In formula (3), R 31 , and R 33 Each of these independently represents a substituted or unsubstituted alkyl group, and R 32 R represents a substituted or unsubstituted alkylene group. 34 This represents an electron-donating base.

[0039] R 31 , and R 33 These may be unsubstituted alkyl groups, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance. 31 , and R 33 This group may be a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, n-pentyl group, n-hexyl group, n-heptyl group, or aralkyl group, and may be a methyl group from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0040] R 32 These may be unsubstituted alkylene groups, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance. 32 This group may be a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, or an isobutylene group, and a methylene group may be preferred from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0041] Electron child donor (R 34Examples of alkyl groups include alkyl groups, alkoxy groups, hydroxyl groups, amino groups, alkylamino groups, etc. Examples of alkyl groups include methyl groups, ethyl groups, n-propyl groups, isopropyl groups, etc. Examples of alkoxy groups include methoxy groups, ethoxy groups, etc. Electron-withdrawing groups (R 34 ) may be an alkyl group or alkoxy group, or a methyl group or a methoxy group, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance. 34 The benzene ring to which R is bonded may contain multiple electron-donating groups, 34 The number of electron-donating groups on the benzyl group to which it is bonded may be 3 or less, 2 or less, or 1. 34 The benzyl group to which it is attached is at position 4 (R 34 The R of the benzyl group to which it is bonded 32 The 4th position when the bond position with is considered the 1st position. 34 The R of the benzyl group to which it is bonded 32 It may have at least one electron-donating group in the para position relative to the bond position with the other atom.

[0042] In formula (3), the benzene ring bonded to the nitrogen atom may or may not have substituents.

[0043] Examples of cations represented by formula (3) include (4-methylbenzyl)dimethylanilinium cation, (4-methoxybenzyl)dimethylanilinium cation, (4-hydroxybenzyl)dimethylanilinium cation, (4-aminobenzyl)dimethylanilinium cation, (4-ethylbenzyl)dimethylanilinium cation, (4-ethoxybenzyl)dimethylanilinium cation, (4-methylbenzyl)methylethylanilinium cation, (4-methoxybenzyl)methylethylanilinium cation, (4-hydroxybenzyl)methylethylanilinium cation, (4-aminobenzyl)methylethylanilinium cation, (4-methylbenzyl)diethylanilinium cation, (4-hydroxybenzyl)diethylanilinium cation, and (4-aminobenzyl)diethylanilinium cation. The cation represented by formula (3) may also be a (4-methylbenzyl)dimethylanilinium cation, from the viewpoint of achieving better low-temperature curability, storage stability, corrosion resistance, heat resistance, and connection resistance.

[0044] The content of curing agent A in the adhesive composition may be 1% by mass or more, 2% by mass or more, or 3% by mass or more, based on the total mass of the adhesive composition, from the viewpoint of sufficiently promoting the curing reaction. The content of curing agent A in the adhesive composition may be 20% by mass or less, 17% by mass or less, or 15% by mass or less, based on the total mass of the adhesive composition, from the viewpoint of improving the physical properties of the cured product. From these viewpoints, the content of curing agent A in the adhesive composition may be 1 to 20% by mass, 3 to 17% by mass or 5 to 15% by mass, based on the total mass of the adhesive composition. The content of curing agent A in the adhesive composition may be 4% by mass or more, 4.5% by mass or more, or 5% by mass or more, based on the total mass of the adhesive composition, and may also be 13% by mass or less, 11% by mass or less, 9% by mass or less, 7% by mass or less, or 5% by mass or less, based on the total mass of the adhesive composition.

[0045] From the viewpoint of sufficiently promoting the curing reaction, the content of curing agent A in the adhesive composition may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total mass of the adhesive composition excluding conductive particles. From the viewpoint of improving the physical properties of the cured product, the content of curing agent A in the adhesive composition may be 20% by mass or less, 17% by mass or less, or 15% by mass or less, based on the total mass of the adhesive composition excluding conductive particles. From these viewpoints, the content of curing agent A in the adhesive composition may be 1 to 20% by mass, 3 to 17% by mass or 5 to 15% by mass, based on the total mass of the adhesive composition excluding conductive particles. The content of curing agent A in the adhesive composition may be 4% by mass or more, 4.5% by mass or more, or 5% by mass or more, based on the total mass of the adhesive composition excluding conductive particles, and may also be 13% by mass or less, 11% by mass or less, 9% by mass or less, 7% by mass or less, or 5% by mass or less.

[0046] From the viewpoint of sufficiently promoting the curing reaction, the content of curing agent A in the adhesive composition may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total mass of the adhesive composition excluding conductive particles and fillers. From the viewpoint of improving the physical properties of the cured product, the content of curing agent A in the adhesive composition may be 30% by mass or less, 27% by mass or less, 25% by mass or less, 22% by mass or less, or 20% by mass or less, based on the total mass of the adhesive composition excluding conductive particles and fillers. From these viewpoints, the content of curing agent A in the adhesive composition may be 1 to 30% by mass, 3 to 27% by mass, or 5 to 20% by mass, based on the total mass of the adhesive composition excluding conductive particles and fillers. The content of curing agent A in the adhesive composition may be 6% by mass or more, 7% by mass or more, or 7.5% by mass or more, based on the total mass of the adhesive composition excluding conductive particles and fillers, and may also be 18% by mass or less, 16% by mass or less, 14% by mass or less, 12% by mass or less, 10% by mass or less, or 8% by mass or less.

[0047] From the viewpoint of sufficiently promoting the curing reaction, the content of curing agent A in the adhesive composition may be 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound. From the viewpoint of improving the physical properties of the cured product, the content of curing agent A in the adhesive composition may be 40 parts by mass or less, 37 parts by mass or less, 34 parts by mass or less, 31 parts by mass or less, 28 parts by mass or less, 25 parts by mass or less, 22 parts by mass or less, or 20 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound. From these viewpoints, the content of curing agent A in the adhesive composition may be 3 to 40 parts by mass, more than 3 parts by mass and 40 parts by mass or less, more than 5 parts by mass and 40 parts by mass or less, 5 to 37 parts by mass, or 10 to 20 parts by mass, based on 100 parts by mass of the cationic polymerizable compound. The content of curing agent A in the adhesive composition may be 11 parts by mass or more, 12 parts by mass or more, 13 parts by mass or more, or 14 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound, and may also be 18 parts by mass or less, 17 parts by mass or less, 16 parts by mass or less, or 15 parts by mass or less.

[0048] If the adhesive composition contains an epoxy compound, the content of curing agent A in the adhesive composition may be 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more, based on 100 parts by mass of the epoxy compound, from the viewpoint of sufficiently promoting the curing reaction. The content of curing agent A in the adhesive composition may be 40 parts by mass or less, 37 parts by mass or less, 34 parts by mass or less, 31 parts by mass or less, 28 parts by mass or less, 25 parts by mass or less, 22 parts by mass or less, or 20 parts by mass or less, based on 100 parts by mass of the epoxy compound, from the viewpoint of improving the physical properties of the cured product. From these viewpoints, the content of curing agent A in the adhesive composition may be 3 to 40 parts by mass, 5 to 37 parts by mass, or 10 to 20 parts by mass, based on 100 parts by mass of the epoxy compound. The content of curing agent A in the adhesive composition may be 11 parts by mass or more, 12 parts by mass or more, 13 parts by mass or more, or 14 parts by mass or more, based on 100 parts by mass of epoxy compound, and may also be 18 parts by mass or less, 17 parts by mass or less, 16 parts by mass or less, or 15 parts by mass or less.

[0049] If the adhesive composition contains an oxetane compound, the content of curing agent A in the adhesive composition may be 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more, based on 100 parts by mass of the oxetane compound, from the viewpoint of sufficiently promoting the curing reaction. The content of curing agent A in the adhesive composition may be 40 parts by mass or less, 37 parts by mass or less, 34 parts by mass or less, 31 parts by mass or less, 28 parts by mass or less, 25% by mass or less, 22% by mass or less, or 20 parts by mass or less, based on 100 parts by mass of the oxetane compound, from the viewpoint of improving the physical properties of the cured product. From these viewpoints, the content of curing agent A in the adhesive composition may be 3 to 40 parts by mass, 5 to 37 parts by mass, or 10 to 20 parts by mass, based on 100 parts by mass of the oxetane compound. The content of curing agent A in the adhesive composition may be 11 parts by mass or more, 12 parts by mass or more, 13 parts by mass or more, or 14 parts by mass or more, based on 100 parts by mass of the oxetane compound, and may also be 18 parts by mass or less, 17 parts by mass or less, 16 parts by mass or less, or 15 parts by mass or less.

[0050] [Conductive particles] The adhesive composition may further contain conductive particles. The conductive particles are not particularly limited as long as they are conductive particles, and examples include metal particles composed of metals such as gold, silver, palladium, nickel, copper, and solder; conductive carbon particles composed of conductive carbon; and coated conductive particles comprising a core containing non-conductive glass, ceramic, or plastic (such as polystyrene), and a coating layer containing the above-mentioned metal or conductive carbon that covers the core. The conductive particles may be coated conductive particles because they are easily deformable by heating and / or pressurizing, and when electrically connecting electrodes, they can increase the contact area between the electrodes and the conductive particles, thereby further improving conductivity between the electrodes. The conductive particles may also be solder particles because they provide a stronger connection between electrodes.

[0051] The solder particles may contain at least one selected from the group consisting of tin, tin alloys, indium, and indium alloys, from the viewpoint of achieving both connection strength and a low melting point. Furthermore, the solder particles may contain at least one selected from the group consisting of In-Bi alloys, In-Sn alloys, In-Sn-Ag alloys, Sn-Au alloys, Sn-Bi alloys, Sn-Bi-Ag alloys, Sn-Ag-Cu alloys, and Sn-Cu alloys, from the viewpoint of obtaining higher reliability during high-temperature, high-humidity tests and thermal shock tests.

[0052] The average particle diameter of conductive particles may be 1 μm or more, 2 μm or more, or 2.5 μm or more, from the viewpoint of excellent dispersibility and conductivity. The average particle diameter of conductive particles may be 20 μm or less, 15 μm or less, 10 μm or less, 8 μm or less, 6 μm or less, 5.5 μm or less, or 5 μm or less, from the viewpoint of ensuring insulation between adjacent electrodes. From these viewpoints, the average particle diameter of conductive particles may be 1 to 20 μm, 1 to 15 μm, 1 to 10 μm, 1 to 8 μm, or 1 to 6 μm.

[0053] The average particle diameter of conductive particles is determined by observing 300 conductive particles contained in the adhesive composition using a scanning electron microscope (SEM), measuring the particle diameter of each conductive particle, and taking the average of the particle diameters of the 300 conductive particles. If the conductive particles are not spherical, the particle diameter of the conductive particle is defined as the diameter of the circle circumscribing the conductive particle in the SEM observation image.

[0054] The particle density of conductive particles in the adhesive composition is set to 100 particles / mm² from the viewpoint of obtaining stable connection resistance. 2 More than 1000 pieces / mm 2 or more, or 3000 pieces / mm 2 The above may be sufficient. The particle density of conductive particles in the adhesive composition should be 100,000 particles / mm² from the viewpoint of ensuring insulation between adjacent electrodes. 2 Below, 50000 pieces / mm 2 The following, or 30,000 pieces / mm 2 The following may apply: From these viewpoints, the particle density of conductive particles in the adhesive composition is 100 to 100,000 particles / mm². 2, 1000~50000 pieces / mm 2 , or 3000-30000 pieces / mm 2 That's fine.

[0055] The content of conductive particles may be 10% by mass or more, 20% by mass or more, or 25% by mass or more, based on the total mass of the adhesive composition. The content of conductive particles may be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the total mass of the adhesive composition.

[0056] The content of conductive particles may be 10 parts by mass or more, 30 parts by mass or more, 50 parts by mass or more, 70 parts by mass or more, or 90 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound. The content of conductive particles may be 200 parts by mass or less, 150 parts by mass or less, 120 parts by mass or less, or 100 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound.

[0057] If the adhesive composition contains conductive particles, the content of curing agent A in the adhesive composition may be 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, 10 parts by mass or more, 11 parts by mass or more, 12 parts by mass or more, 13 parts by mass or more, or 14 parts by mass or more, based on 100 parts by mass of conductive particles. The content of curing agent A in the adhesive composition may be 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 27 parts by mass or less, 25 parts by mass or less, 22 parts by mass or less, 20 parts by mass or less, 18 parts by mass or less, 17 parts by mass or less, 16 parts by mass or less, or 15 parts by mass or less, based on 100 parts by mass of conductive particles. The content of curing agent A in the adhesive composition may be 3 to 40 parts by mass, 10 to 40 parts by mass, 3 to 30 parts by mass, or 5 to 30 parts by mass, based on 100 parts by mass of conductive particles.

[0058] [Thermoplastic resin] The adhesive composition may further contain a thermoplastic resin. The inclusion of a thermoplastic resin makes it easier to form the adhesive composition into a film. Examples of thermoplastic resins include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester urethane resin, and acrylic rubber. These may be used individually or in combination of two or more.

[0059] The weight-average molecular weight (Mw) of the thermoplastic resin may be, for example, 5000 or more, 10000 or more, 20000 or more, or 40000 or more, and may be 200000 or less, 100000 or less, 80000 or less, or 60000 or less. The weight-average molecular weight of the thermoplastic resin shall be measured by gel permeation chromatography (GPC) and converted using a calibration curve with standard polystyrene.

[0060] The thermoplastic resin content may be 5% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more, based on the total mass of the adhesive composition. The thermoplastic resin content may be 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less, based on the total mass of the adhesive composition.

[0061] The content of the thermoplastic resin may be 10 parts by mass or more, 30 parts by mass or more, 50 parts by mass or more, or 60 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound. The content of the thermoplastic resin may be 100 parts by mass or less, 80 parts by mass or less, 60 parts by mass or less, 40 parts by mass or less, or 20 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound.

[0062] If the adhesive composition contains a thermoplastic resin, the content of curing agent A in the adhesive composition may be 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, 10 parts by mass or more, 12 parts by mass or more, 14 parts by mass or more, 16 parts by mass or more, 18 parts by mass or more, or 20 parts by mass or more, based on 100 parts by mass of the thermoplastic resin. The content of curing agent A in the adhesive composition may be 150 parts by mass or less, 130 parts by mass or less, 100 parts by mass or less, 80 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less, based on 100 parts by mass of the thermoplastic resin.

[0063] [Coupling agent] The adhesive composition may further contain a coupling agent. The adhesive properties of the adhesive composition can be further improved by the inclusion of a coupling agent. The coupling agent may be a silane coupling agent, such as vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, and condensates thereof. These may be used individually or in combination of two or more.

[0064] The coupling agent content may be 0.5% by mass or more, 1% by mass or more, or 2% by mass or more, based on the total mass of the adhesive composition. The coupling agent content may be 15% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total mass of the adhesive composition.

[0065] The content of the coupling agent may be 1 part by mass or more, 4 parts by mass or more, or 6 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound. The content of the coupling agent may be 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, or 6 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound.

[0066] If the adhesive composition contains a coupling agent, the content of curing agent A in the adhesive composition may be 25 parts by mass or more, 30 parts by mass or more, 40 parts by mass or more, 60 parts by mass or more, 80 parts by mass or more, 100 parts by mass or more, 120 parts by mass or more, 140 parts by mass or more, 160 parts by mass or more, 180 parts by mass or more, or 200 parts by mass or more, based on 100 parts by mass of the coupling agent. The content of curing agent A in the adhesive composition may be 300 parts by mass or less, 270 parts by mass or less, 250 parts by mass or less, or 200 parts by mass or less, based on 100 parts by mass of the coupling agent.

[0067] [Filling material] The adhesive composition may further contain a filler. The adhesive composition can further improve connection reliability by containing a filler. Examples of fillers include non-conductive fillers (e.g., non-conductive particles). The filler may be either an inorganic filler or an organic filler.

[0068] Examples of inorganic fillers include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titania particles, and zirconia particles; and metal nitride particles. These may be used individually or in combination of two or more types.

[0069] Examples of organic fillers include silicone particles, methacrylate-butadiene-styrene particles, acrylic-silicone particles, polyamide particles, and polyimide particles. These may be used individually or in combination of two or more types.

[0070] The filler may be an inorganic filler, or silica particles, from the viewpoint of improving film moldability and the reliability of the connecting structure. The silica particles may be crystalline silica particles or amorphous silica particles, and these silica particles may be synthetic products. The silica may be synthesized by a dry method or a wet method. The silica particles may include at least one selected from the group consisting of fumed silica particles and sol-gel silica particles.

[0071] The silica particles may be surface-treated silica particles from the viewpoint of excellent dispersibility in adhesive components. Surface-treated silica particles are obtained by hydrophobizing the hydroxyl groups on the surface of the silica particles with a silane compound or a silane coupling agent. Surface-treated silica particles may be silica particles surface-treated with a silane compound such as an alkoxysilane compound, a disilazane compound, or a siloxane compound, or silica particles surface-treated with a silane coupling agent.

[0072] Examples of alkoxysilane compounds include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, dimethoxydiphenylsilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and 3,3,3-trifluoropropyltrimethoxysilane.

[0073] Examples of disilazane compounds include 1,1,1,3,3,3-hexamethyldisilazane, 1,3-diphenyltetramethyldisilazane, 1,3-bis(3,3,3,-trifluoropropyl)-1,1,3,3,-tetramethyldisilazane, and 1,3-divinyl-1,1,3,3-tetramethyldisilazane.

[0074] Siloxane compounds include tetradecamethylcycloheptasiloxane, decamethylcyclopentasiloxane, hexaphenylcyclosiloxane, octadecamethylcyclononasiloxane, hexadecamethylcyclooctasiloxane, dodecamethylcyclohexasiloxane, octaphenylcyclotetrasiloxane, hexamethylcyclotrisiloxane, heptaphenyldisiloxane, tetradecamethylhexasiloxane, dodecamethylpentasiloxane, hexame Til disiloxane, decamethyltetrasiloxane, hexamethoxydisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, 1,3-vinyltetramethyldisiloxane, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane, 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane, 1,3-dimethyl-1,3-diphenyl-1,3- Divinyldisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 1,1,1,3,5,5,5-heptamethyl-3-(3-glycidoyloxypropyl)trisiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, 1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy]trisiloxane, 1,3,-bis[2-(7 Examples include -oxabicyclo[4.1.0]heptan-3-yl)ethyl]-1,1,3,3,-tetramethyldisiloxane, 1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]-3-vinyltrisiloxane, 3-[[dimethyl(vinyl)silyl]oxy]-1,1,5,5,-tetramethyl-3-phenyl-1,5-vinyltrisiloxane, octavinyloctasilsesquioxane, octaphenyloctasilsesquioxane, etc.

[0075] Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(Ammyl Examples include (noethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, and 3-trimethoxysilylpropyl succinic anhydride.

[0076] Silica particles surface-treated with a silane compound or silane coupling agent may be further surface-treated with silane compounds such as 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, or trimethoxyphenylsilane to further hydrophobize the hydroxyl group residues on the surface of the silica particles.

[0077] Surface-treated silica particles may contain at least one selected from the group consisting of reaction products of silica and trimethoxyoctylsilane (hydrolysis products), reaction products of silica and dimethylsiloxane, reaction products of silicon dioxide or silica and dichloro(dimethyl)silane, reaction products of silica and bis(trimethylsilyl)amine (hydrolysis products), and reaction products of silica and hexamethyldisilazane, from the viewpoint of easily controlling fluidity when the adhesive film is pressed together when the adhesive composition is used as an adhesive film for circuit connection, and from the viewpoint of improving the mechanical properties and water resistance of the connected structure after pressing. They may also contain at least one selected from the group consisting of reaction products of silica and trimethoxyoctylsilane and reaction products of silica and bis(trimethylsilyl)amine.

[0078] The filler content may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total mass of the adhesive composition. The filler content may be 50% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total mass of the adhesive composition.

[0079] The content of the filler may be 10 parts by mass or more, 25 parts by mass or more, or 40 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound. The content of the filler may be 100 parts by mass or less, 60 parts by mass or less, or 40 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound.

[0080] If the adhesive composition contains a filler, the content of curing agent A in the adhesive composition may be 5 parts by mass or more, 8 parts by mass or more, 10 parts by mass or more, 12 parts by mass or more, 14 parts by mass or more, 16 parts by mass or more, 18 parts by mass or more, or 20 parts by mass or more, based on 100 parts by mass of the filler. The content of curing agent A in the adhesive composition may be 120 parts by mass or less, 100 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less, based on 100 parts by mass of the filler.

[0081] [Hardening inhibitor] The adhesive composition may further contain a curing inhibitor. Examples of curing inhibitors include amides having a lactam ring. By including an amide having a lactam ring in the adhesive composition, it becomes easier to maintain excellent adhesion even when the adhesive composition is stored in contact with air, and it becomes easier to ensure connection reliability even when the connected structure is exposed to a high temperature and high humidity environment (e.g., 85°C, 85%RH) for a long period of time after the components are connected with the adhesive composition.

[0082] The amide having a lactam ring may have 3 to 12 carbon atoms constituting the lactam ring. The number of carbon atoms constituting the lactam ring may be 3 to 10, 3 to 8, 3 to 7, or 3 to 6, from the viewpoint of ensuring connection reliability even when the connecting structure is exposed to high temperature and high humidity environments (e.g., 85°C, 85%RH) for a long period of time.

[0083] Amides having a lactam ring may have functional groups bonded to the lactam ring. Examples of functional groups include carboxyl groups, carboxylic acid bases, hydroxyl groups, alkoxy groups, alkyl groups, ester groups, sulfo groups, sulfonic acid bases, carbonyl groups, amino groups, amide groups, carboxamide groups, nitro groups, cyano groups, halogen atoms, and the like.

[0084] The lactam ring amide may include at least one selected from the group consisting of 2-azetidinone, 2-pyrrolidinone (2-pyrrolidone), 2-piperidinone, ε-caprolactam, capryloractam, and laurolactam (ω-laurinlactam), and may include ε-caprolactam, from the viewpoint of maintaining excellent adhesion even when the adhesive composition is stored in contact with air, and from the viewpoint of ensuring connection reliability even when the connecting structure is exposed to high temperature and high humidity environments (e.g., 85°C, 85%RH) for a long period of time.

[0085] The content of lactam ring-containing amides may be 0.001% by mass or more, 0.003% by mass or more, or 0.005% by mass or more, based on the total mass of the adhesive composition, from the viewpoint of maintaining excellent adhesion even when the adhesive composition is stored in contact with air, and from the viewpoint of ensuring connection reliability even when the connected structure is exposed to high temperature and high humidity environments (e.g., 85°C, 85%RH) for a long period of time. From these viewpoints, the content of lactam ring-containing amides may be 0.001 to 2% by mass, 0.003 to 1% by mass, or 0.005 to 0.8% by mass, based on the total mass of the adhesive composition.

[0086] The content of the amide having a lactam ring may be 0.001 parts by mass or more, 0.005 parts by mass or more, or 0.01 parts by mass or more, based on 100 parts by mass of the cationic polymerizable compound. The content of the amide having a lactam ring may be 1 part by mass or less, 0.5 parts by mass or less, or 0.1 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound.

[0087] If the adhesive composition contains an amide having a lactam ring, the content of curing agent A in the adhesive composition may be 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more, based on 0.01 parts by mass of the amide having a lactam ring. The content of curing agent A in the adhesive composition may be 20 parts by mass or less, 10 parts by mass or less, 5 parts by mass or less, or 4 parts by mass or less, based on 0.01 parts by mass of the amide having a lactam ring. The content of curing agent A in the adhesive composition may be 1 to 20 parts by mass, 2 to 10 parts by mass, or 3 to 5 parts by mass, based on 0.01 parts by mass of the amide having a lactam ring.

[0088] [Other ingredients] The adhesive composition may further contain other components besides those listed above. These other components may include stabilizers, colorants, antioxidants, solvents, and curing agents other than curing agent A. The adhesive composition may further contain a radical polymerizable compound and a radical polymerization initiator.

[0089] Examples of radical polymerizable compounds include acrylic compounds. Examples of acrylic compounds include (meth)acrylic acid compounds, (meth)acrylate compounds, and their imide compounds. These may be used in monomer or oligomer form, or in combination. Radical polymerizable compounds may be used individually or in combination of two or more.

[0090] Specific examples of acrylic compounds include alkyl (meth)acrylate compounds such as methyl acrylate, ethyl acrylate, isopropyl acrylate, and isobutyl acrylate; polyol poly(meth)acrylate compounds such as ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, and tetramethylolmethane tetraacrylate; aryloxy-hydroxyalkyl (meth)acrylate compounds such as 2-hydroxy-1,3-diacryloxypropane, 2,2-bis[4-(acryloxymethoxy)phenyl]propane, and 2,2-bis[4-(acryloxypolyethoxy)phenyl]propane; and dicyclopentenyl acrylate, tricyclodecanyl acrylate, and tris(acryloyloxyethyl) isocyanurate.

[0091] Radical polymerization initiators may generate free radicals upon exposure to light or heat. Examples of radical polymerization initiators include organic peroxides and azo compounds. Examples of organic peroxides include peroxyesters, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, peroxyketals, hydroperoxides, and silyl peroxides. Radical polymerization initiators may be used individually or in combination of two or more.

[0092] Examples of peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanonate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethylhexanonate, L-hexyl peroxy-2-ethylhexanonate, L Examples include t-butyl peroxy-2-ethylhexanonate, t-butyl peroxyisobutyrate, 1,1-bis(t-butyl peroxy)cyclohexane, t-hexyl peroxyisopropyl monocarbonate, t-butyl peroxy-3,5,5-trimethylhexanonate, t-butyl peroxylaurate, 2,5-dimethyl-2,5-di(m-toluyl peroxy)hexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, and t-butyl peroxyacetate.

[0093] Examples of dialkyl peroxides include α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and t-butylcumyl peroxide. Examples of hydroperoxides include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

[0094] Examples of diacyl peroxides include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl peroxytoluene, and benzoyl peroxide.

[0095] Examples of peroxydicarbonates include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, di(2-ethylhexylperoxy)dicarbonate, dimethoxybutyl peroxydicarbonate, and di(3-methyl-3-methoxybutylperoxy)dicarbonate.

[0096] Specific examples of peroxyketals include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-(t-butylperoxy)cyclododecane, and 2,2-bis(t-butylperoxy)decane.

[0097] Specific examples of silyl peroxides include t-butyltrimethylsilyl peroxide, bis(t-butyl)dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis(t-butyl)divinylsilyl peroxide, tris(t-butyl)vinylsilyl peroxide, t-butyltrialylsilyl peroxide, bis(t-butyl)diallylsilyl peroxide, and tris(t-butyl)allylsilyl peroxide.

[0098] In an adhesive composition, when differential scanning calorimetry (DSC) is performed under conditions of a nitrogen atmosphere, a heating rate of 10°C / min, and a measurement temperature range of 40 to 300°C, multiple endothermic peaks may occur, or only one endothermic peak may occur. When multiple endothermic peaks occur, the area ratio (first peak / second peak) between the first endothermic peak (first peak) and the second endothermic peak (second peak) may be 2 or more, 3 or more, or 5 or more, or 20 or less, 17 or less, or 15 or less.

[0099] In an adhesive composition, when differential scanning calorimetry (DSC) is performed under nitrogen atmosphere, heating rate of 10°C / min, and measurement temperature range of 40 to 300°C, the amount of heat generated from the area of ​​the first endothermic peak may be 50 J / g or more, 80 J / g or more, or 100 J / g or more, and may be 400 J / g or less, 350 J / g or less, or 300 J / g or less.

[0100] The reaction rate when the adhesive composition is heat-treated at 40°C for 15 hours may be 10% or less. The reaction rate was calculated using differential scanning calorimetry (DSC) from the first endothermic peak (first peak) that occurs, using the following formula. Response rate (%) = 100 × (1 - b / a) In the formula, a and b are as follows: a: Total heat generation of unreacted material (unit: J / g) b: Total heat generated by the reactants after heat treatment (unit: J / g)

[0101] The elastic modulus of the reactant obtained by heating the adhesive composition at 180°C for 1 hour may be 0.01 GPa or higher, 0.05 GPa or higher, or 0.1 GPa or higher, and may be 5 GPa or lower, 3 GPa or lower, or 1 GPa or lower. The elastic modulus at 300°C refers to the storage modulus at 300°C obtained by laminating the adhesive composition to a thickness of 100 to 200 μm, preparing a cured film for evaluation by heating it in a constant temperature bath at 180°C for 1 hour, and then performing a DMA measurement on the cured film using a dynamic viscoelasticity measuring device (e.g., E4000 manufactured by UBM Co., Ltd.) at a heating rate of 10°C / min from 40 to 350°C.

[0102] <Adhesive film for circuit connections> The adhesive composition may be in the form of a film. That is, another embodiment of the present disclosure is a circuit connection adhesive film containing a cationic polymerizable compound and a curing agent A. The circuit connection adhesive film may contain conductive particles.

[0103] The content of cationic polymerizable compounds in the circuit connection adhesive film may be 10% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, based on the total mass of the circuit connection adhesive film, from the viewpoint of ensuring the curability of the circuit connection adhesive film. The content of cationic polymerizable compounds in the circuit connection adhesive film may be 70% by mass or less, 50% by mass or less, 40% by mass or less, or 35% by mass or less, based on the total mass of the circuit connection adhesive film, from the viewpoint of ensuring the formation of the circuit connection adhesive film. From these viewpoints, the content of cationic polymerizable compounds in the circuit connection adhesive film may be 10 to 70% by mass, based on the total mass of the circuit connection adhesive film.

[0104] The content of curing agent A in the circuit connection adhesive film may be 1% by mass or more, 2% by mass or more, or 3% by mass or more, based on the total mass of the circuit connection adhesive film, from the viewpoint of sufficiently promoting the curing reaction. The content of curing agent A in the circuit connection adhesive film may be 20% by mass or less, 17% by mass or less, or 15% by mass or less, based on the total mass of the circuit connection adhesive film, from the viewpoint of improving the physical properties of the cured product. From these viewpoints, the content of curing agent A in the circuit connection adhesive film may be 1 to 20% by mass, 2 to 17% by mass or 3 to 15% by mass, based on the total mass of the circuit connection adhesive film. The content of curing agent A in the circuit connection adhesive film may be 4% by mass or more, 4.5% by mass or more, or 5% by mass or more, based on the total mass of the circuit connection adhesive film, and may also be 13% by mass or less, 11% by mass or less, 9% by mass or less, 7% by mass or less, or 5% by mass or less, based on the total mass of the circuit connection adhesive film.

[0105] From the viewpoint of sufficiently promoting the curing reaction, the content of curing agent A in the circuit connection adhesive film may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total mass of the circuit connection adhesive film excluding conductive particles. From the viewpoint of improving the physical properties of the cured product, the content of curing agent A in the circuit connection adhesive film may be 20% by mass or less, 17% by mass or less, or 15% by mass or less, based on the total mass of the circuit connection adhesive film excluding conductive particles. From these viewpoints, the content of curing agent A in the circuit connection adhesive film may be 1 to 20% by mass, 3 to 17% by mass or 5 to 15% by mass, based on the total mass of the circuit connection adhesive film excluding conductive particles. The content of curing agent A in the circuit connection adhesive film may be 4% by mass or more, 4.5% by mass or more, or 5% by mass or more, based on the total mass of the circuit connection adhesive film excluding conductive particles, and may also be 13% by mass or less, 11% by mass or less, 9% by mass or less, 7% by mass or less, or 5% by mass or less.

[0106] From the viewpoint of sufficiently promoting the curing reaction, the content of curing agent A in the circuit connection adhesive film may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total mass of the circuit connection adhesive film excluding conductive particles and fillers. From the viewpoint of improving the physical properties of the cured product, the content of curing agent A in the circuit connection adhesive film may be 30% by mass or less, 27% by mass or less, 25% by mass or less, 22% by mass or less, or 20% by mass or less, based on the total mass of the circuit connection adhesive film excluding conductive particles and fillers. From these viewpoints, the content of curing agent A in the circuit connection adhesive film may be 1 to 30% by mass, 3 to 27% by mass, or 5 to 20% by mass, based on the total mass of the circuit connection adhesive film excluding conductive particles and fillers. The content of curing agent A in the adhesive film for circuit connections may be 6% by mass or more, 7% by mass or more, or 7.5% by mass or more, based on the total mass of the adhesive film for circuit connections excluding conductive particles and fillers, and may also be 18% by mass or less, 16% by mass or less, 14% by mass or less, 12% by mass or less, 10% by mass or less, or 8% by mass or less.

[0107] The conductive particles may be arranged in a predetermined pattern in a plan view of the adhesive film for circuit connection. For example, the conductive particles may be arranged regularly in a plan view of the adhesive film for circuit connection, or they may be arranged regularly and at approximately equal intervals in a plan view of the adhesive film for circuit connection. The position and number of conductive particles can be set according to, for example, the shape, size, and pattern of the electrodes to be connected. It can be confirmed, for example, that at least some of the conductive particles are arranged in a predetermined pattern by observing the main surface of the adhesive film for circuit connection from above using an electron microscope or the like. As a method for regularly arranging conductive particles in a plan view of the adhesive film for circuit connection, for example, a substrate is prepared having a plurality of recesses on its surface, the recesses of which are regularly arranged in a predetermined pattern (for example, a pattern corresponding to the electrode pattern of a circuit member), conductive particles are placed in the recesses, and then the conductive particles are transferred to the adhesive film.

[0108] The particle density of conductive particles in the adhesive film for circuit connections should be 100 particles / mm² from the viewpoint of obtaining stable connection resistance. 2 More than 1000 pieces / mm 2 or more, or 3000 pieces / mm 2 The above is acceptable. The particle density of conductive particles in the adhesive film for circuit connections should be 100,000 particles / mm² from the viewpoint of ensuring insulation between adjacent electrodes. 2 Below, 50000 pieces / mm 2 The following, or 30,000 pieces / mm 2 The following is acceptable. From these perspectives, the particle density of conductive particles in the adhesive film for circuit connections is 100 to 100,000 particles / mm². 2 , 1000~50000 pieces / mm 2 , or 3000-30000 pieces / mm 2 That's fine.

[0109] The content of conductive particles may be 10% by mass or more, 20% by mass or more, or 25% by mass or more, based on the total mass of the adhesive film for circuit connection. The content of conductive particles may be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the total mass of the adhesive film for circuit connection.

[0110] The thermoplastic resin content in the circuit connection adhesive film may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total mass of the circuit connection adhesive film. The thermoplastic resin content in the circuit connection adhesive film may be 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total mass of the circuit connection adhesive film.

[0111] The coupling agent content in the circuit connection adhesive film may be 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, based on the total mass of the circuit connection adhesive film. The coupling agent content in the circuit connection adhesive film may be 10% by mass or less, 5% by mass or less, or 2% by mass or less, based on the total mass of the circuit connection adhesive film.

[0112] The filler content in the adhesive film for circuit connections may be 5% by mass or more, 10% by mass or more, or 12% by mass or more, based on the total mass of the adhesive film for circuit connections. The filler content in the adhesive film for circuit connections may be 30% by mass or less, 20% by mass or less, or 15% by mass or less, based on the total mass of the adhesive film for circuit connections.

[0113] The content of each component of the circuit connection adhesive film, based on 100 parts by mass of cationic polymerizable compounds, may be within the same range as the content of each component of the cationic polymerizable compounds, based on 100 parts by mass of cationic polymerizable compounds, in the above-mentioned adhesive composition.

[0114] The adhesive film for circuit connections may be a single layer or may have a multilayer structure in which multiple layers are laminated. When the adhesive film for circuit connections has a multilayer structure, it may comprise, for example, a first adhesive layer containing a cationic polymerizable compound and a curing agent A, and a second adhesive layer other than the first adhesive layer. That is, the adhesive film for circuit connections may comprise a first adhesive layer and a second adhesive layer laminated on the first adhesive layer. At least one of the first adhesive layer and the second adhesive layer may contain a cationic polymerizable compound, a curing agent A, and conductive particles. When the adhesive film for circuit connections has a multilayer structure, the content of each of the above components in each layer may be within the above content range based on the total mass of each layer, or within the above content range based on the total mass of each layer.

[0115] The adhesive film for circuit connections may have multiple regions with different types and contents of components. The adhesive film for circuit connections may, for example, comprise a first region and a second region located on the first region, where the first region may contain a cationic polymerizable compound and a curing agent A. That is, the adhesive film for circuit connections may have a first region formed from a first adhesive composition containing a cationic polymerizable compound and a curing agent A, and a second region formed from a second adhesive composition located on the first region. When the adhesive film for circuit connections has multiple regions, the contents of each component in each region may be within the above-mentioned content range based on the total mass of each region, or within the above-mentioned content range based on the total mass of each region.

[0116] The adhesive film for circuit connections may be provided on a substrate (e.g., a PET film). The adhesive film for circuit connections with a substrate can be manufactured, for example, by applying an adhesive composition containing conductive particles onto the substrate using a knife coater, roll coater, applicator, comma coater, die coater, or the like.

[0117] Figure 1 is a schematic cross-sectional view showing an adhesive film for circuit connection according to one embodiment. As shown in Figure 1, in one embodiment, the adhesive film 1 for circuit connection is composed of a single layer consisting of an adhesive component 2 and conductive particles 3 dispersed in the adhesive component 2. In one embodiment, the adhesive component 2 contains at least a cationic polymerizable compound and a curing agent A. The adhesive film 1 for circuit connection may be in an uncured state or may be partially cured.

[0118] The thickness of the circuit connection adhesive film 1 may be, for example, 3 μm or more or 10 μm or more, and 30 μm or less or 20 μm or less.

[0119] In one embodiment, the adhesive film for circuit connection may have a multilayer structure having two or more layers. For example, as shown in Figure 2, the adhesive film for circuit connection 1 may have a two-layer structure comprising a layer containing conductive particles 3A (a first adhesive layer consisting of adhesive component 2A and conductive particles 3A dispersed in adhesive component 2A) 1A, and a layer not containing conductive particles (a second adhesive layer consisting of adhesive component 2B) 1B. In this case, the first adhesive layer 1A may be a layer made of an adhesive composition (first adhesive composition) containing a cationic polymerizable compound, a curing agent A, and conductive particles. The second adhesive layer 1B may be a layer made of an adhesive composition (second adhesive composition) containing a cationic polymerizable compound and a curing agent A. The types and contents of each component contained in the second adhesive layer 1B may be the same as or different from those of the first adhesive layer 1A. The first adhesive layer 1A and the second adhesive layer 1B of the adhesive film for circuit connection 1 may be in an uncured state, or they may be partially cured.

[0120] The thickness of the first adhesive layer 1A may be, for example, 3 μm or more or 5 μm or more, and 15 μm or less or 10 μm or less. The thickness of the second adhesive layer 1B may be, for example, 3 μm or more or 10 μm or more, and 20 μm or less or 15 μm or less. The thickness of the first adhesive layer 1A may be the same as the thickness of the second adhesive layer 1B, or it may be different. The ratio of the thickness of the first adhesive layer 1A to the thickness of the second adhesive layer 1B (thickness of the first adhesive layer 1A / thickness of the second adhesive layer 1B) may be 0.1 or more or 0.3 or more, and 1.5 or less or 0.5 or less.

[0121] The above-mentioned adhesive film for circuit connection may be an anisotropic conductive adhesive film (anisotropic conductive film), or it may be a conductive adhesive film that does not have anisotropic conductivity.

[0122] <Connection Structure> Another embodiment of the present disclosure is a connecting structure comprising a first circuit member having a first electrode, a second circuit member having a second electrode, and a connecting portion disposed between the first circuit member and the second circuit member and electrically connecting the first electrode and the second electrode to each other, wherein the connecting portion includes a cured product of the above-mentioned adhesive film for circuit connection.

[0123] Figure 3 is a schematic cross-sectional view showing one embodiment of the connecting structure. As shown in Figure 3, the structure 10 comprises a first circuit member 4 and a second circuit member 5 facing each other, and a connecting portion 6 that connects the first circuit member 4 and the second circuit member 5 between them.

[0124] The first circuit member 4 comprises a first circuit board 41 and a first electrode 42 formed on the main surface 41a of the first circuit board 41. The second circuit member 5 comprises a second circuit board 51 and a second electrode 52 formed on the main surface 51a of the second circuit board 51.

[0125] The first circuit member 4 and the second circuit member 5 are not particularly limited as long as they are members on which electrodes requiring electrical connection are formed. Examples of members on which electrodes are formed (circuit members, etc.) include inorganic substrates such as semiconductors, glass, and ceramics; polyimide substrates represented by TCP, FPC, COF, etc.; substrates on which electrodes are formed on films such as polycarbonate, polyester, and polyethersulfone; and printed wiring boards. Multiple of these may be used in combination.

[0126] The connection portion 6 contains a cured product of the circuit connection adhesive film 1, an insulating substance 7 which is a cured product of the adhesive component 2, and conductive particles 3. The conductive particles 3 may be arranged not only between the opposing first electrode 42 and second electrode 52, but also between the main surface 41a of the first circuit board 41 and the main surface 51a of the second circuit board 51. In the structure 30, the first electrode 42 and the second electrode 52 are electrically connected via the conductive particles 3. That is, the conductive particles 3 are in contact with both the first electrode 42 and the second electrode 52.

[0127] In structure 10, as described above, the opposing first electrode 42 and second electrode 52 are electrically connected via the conductive particle 3. Therefore, the connection resistance between the first electrode 42 and the second electrode 52 is sufficiently reduced. Consequently, it is possible to facilitate the flow of current between the first electrode 42 and the second electrode 52, and the functions of the first circuit member 4 and the second circuit member 5 can be fully performed.

[0128] <Method for manufacturing a connecting structure> Another embodiment of the present disclosure is a method for manufacturing a connection structure, comprising the steps of interposing the above-mentioned circuit connection adhesive film between a first circuit member having a first electrode and a second circuit member having a second electrode, and then heat-pressing the first circuit member and the second circuit member together to electrically connect the first electrode and the second electrode.

[0129] Figure 4 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a connection structure. As shown in Figure 4(a), first, a first circuit member 4 and a circuit connection adhesive film 1 are prepared. Next, the circuit connection adhesive film 1 is placed on the main surface 41a of the first circuit member 4. If the circuit connection adhesive film 1 is laminated on a substrate (not shown), the laminate is placed on the first circuit member 4 such that the side of the substrate with the circuit connection adhesive film 1 faces the first circuit member 4. If the circuit connection adhesive film 1 has a first adhesive layer 1A and a second adhesive layer 1B as shown in Figure 2, it is preferable to place the adhesive layer containing conductive particles (first adhesive layer 1A) in contact with the main surface 41a of the first circuit member 4, from the viewpoint of improving the number of conductive particles trapped between opposing electrodes.

[0130] Then, the circuit connection adhesive film 1 is pressed in the directions of arrows A and B in Figure 4(a) to temporarily connect the circuit connection adhesive film 1 to the first circuit member 4 (see Figure 4(b)). At this time, heating may be performed along with the pressurization.

[0131] Next, as shown in Figure 4(c), the second circuit member 5 is further placed on the circuit connection adhesive film 1 placed on the first circuit member 4, with the second electrode 52 facing the first circuit member 4 (i.e., the first electrode 42 and the second electrode 52 are positioned facing each other, with the circuit connection adhesive film 1 interposed between the first circuit member 4 and the second circuit member 5). If the circuit connection adhesive film 1 is laminated on a substrate (not shown), the substrate is peeled off before placing the second circuit member 5 on the circuit connection adhesive film 1.

[0132] Then, the circuit connection adhesive film 1 is heat-pressed in the directions of arrows A and B in Figure 4(c). This hardens the circuit connection adhesive film 1, and the main connection is made, electrically connecting the first electrode 42 and the second electrode 52 to each other. As a result, a structure 10 as shown in Figure 3 is obtained.

[0133] In the structure 10 obtained as described above, it is possible to bring the conductive particles 3 into contact with both the opposing first electrode 42 and the second electrode 52, and the connection resistance between the first electrode 42 and the second electrode 52 can be sufficiently reduced.

[0134] By heating and pressurizing the circuit connection adhesive film 1, the adhesive component 2 hardens into an insulating material 7 while the distance between the first electrode 42 and the second electrode 52 is sufficiently reduced, and the first circuit member 4 and the second circuit member 5 are firmly connected via the connection part 6. Furthermore, in the structure 10, a sufficiently high adhesive strength is maintained over a long period of time. Therefore, in the structure 10, changes in the distance between the first electrode 42 and the second electrode 52 over time are sufficiently suppressed, and the long-term reliability of the electrical characteristics between the first electrode 42 and the second electrode 52 is excellent. [Examples]

[0135] The present disclosure will be specifically described below with reference to examples. However, the present disclosure is not limited to the examples described below.

[0136] <Preparation of adhesive film for circuit connection> The components were mixed in the amounts shown in Table 1 (unit: parts by mass) to prepare a first adhesive composition for forming the first adhesive layer and a second adhesive composition for forming the second adhesive layer. The details of each component in Table 1 are as follows, and the amounts of each component in the table represent the amounts of non-volatile components. • Cationic polymerized compounds A1: Alicyclic epoxy resin (product name: CEL8010, manufactured by Daicel Corporation) A2: Oxetane compound (Trade name: OXBP, manufactured by Ube Industries, Ltd.) A3: Epoxy resin (Product name: JER1007, manufactured by Mitsubishi Chemical Corporation) • Hardener B1: Hardener synthesized in Synthesis Example 1 B2: Hardener synthesized in Synthesis Example 2 ·Thermoplastic resin C: Phenoxy resin a synthesized in Synthesis Example 3 • Coupling agent D: Silane coupling agent (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBM-403) ·Filling material E1: Surface-treated silica particles (hydrolysis product of trimethoxyoctylsilane and silica, manufactured by Evonik Industries AG, trade name: Aerosil R805, used after dilution with organic solvent to 10% by mass of nonvolatile content) E2: Surface-treated silica particles (hydrolysis product of silica and bis(trimethylsilyl)amine) • Conductive particles F: Conductive particles prepared as described below • Curing inhibitor G: ε-caprolactam

[0137] <Synthesis Example 1> (Synthesis of N,N-dimethyl,N-(4-methoxybenzyl)anilinium tetrakis(pentafluorophenyl)borate) [Process 1] A 200 mL Erlenmeyer flask was prepared with a stirrer tip placed on a magnetic stirrer. 100 mL of anhydrous acetone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 3.11 g of 4-methoxybenzyl chloride (20 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 6.00 g of sodium iodide (40 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in the flask and stirred at room temperature for 2 hours. After stirring, the precipitate was filtered, and the filtrate was washed three times each with 100 mL of hexane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 50 mL of water. 20 g of sodium sulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the organic layer to dehydrate it. By distillation off the organic solvent, 4.61 g (yield 99%) of 4-methoxybenzyliodide was obtained as a pale yellow liquid.

[0138] [Process 2] A 200 mL Erlenmeyer flask was prepared with a stirrer tip placed on a magnetic stirrer, and 100 mL of hexane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 4.61 g (19 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) of 4-methoxybenzyl iodide were mixed. 2.30 g (19 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) of N,N-dimethylaniline mixed with 5 mL of hexane was added dropwise to the Erlenmeyer flask, and the mixture was stirred at room temperature for 30 minutes. After stirring, 50 mL of methanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reaction mixture, and the methanol layer was washed three times with 100 mL of hexane. The methanol was then removed by distillation to obtain 6.00 g (yield 85%) of N,N-dimethyl,N-(4-methoxybenzyl)anilinium iodide.

[0139] [Process 3A] A 200 mL Erlenmeyer flask was prepared with a stirrer tip placed on a magnetic stirrer, and 50 mL of ethyl acetate and 1.85 g (5.0 mmol) of N,N-dimethyl,N-(4-methoxybenzyl)anilinium iodide were mixed. 38.61 g (5.0 mmol, manufactured by Nippon Shokubai Co., Ltd., TE-PB-NA-10-W) of a 10% aqueous solution of sodium tetrakis(pentafluorophenyl)borate was added dropwise to the Erlenmeyer flask, and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was washed once with 50 mL of saturated sodium bicarbonate aqueous solution, three times with 50 mL of water, and once with saturated brine, and the organic layer was dried over 20 g of sodium sulfate. After that, the organic solvent was removed by distillation, and the mixture was dried under reduced pressure to obtain 2.16 g (yield 47%) of N,N-dimethyl,N-(4-methoxybenzyl)anilinium tetrakis(pentafluorophenyl)borate.

[0140] <Synthesis Example 2> (Synthesis of N,N-dimethyl,N-(4-methoxybenzyl)anilinium tetrakis(pentafluorophenyl)gallate) N,N-dimethyl,N-(4-methoxybenzyl)anilinium-tetrakis(pentafluorophenyl)gallate was synthesized in the same manner as in Synthesis Example 1, except that the 10% aqueous solution of sodium tetrakis(pentafluorophenyl)borate in step 3A was replaced with an aqueous solution of sodium sodium tetrakis(pentafluorophenyl)gallate.

[0141] <Synthesis Example 3> <Synthesis of phenoxy resin a> In a 3000 mL three-necked flask equipped with a Liebig condenser, a calcium chloride tube, and a Teflon® stirring rod connected to a stirring motor, 45 g of 4,4'-(9-fluorenylidene)-diphenol (manufactured by Sigma-Aldrich Japan Co., Ltd.) and 50 g of 3,3',5,5'-tetramethylbiphenol diglycidyl ether (product name: YX-4000H, manufactured by Mitsubishi Chemical Corporation) were dissolved in 1000 mL of N-methylpyrrolidone to prepare the reaction solution. 21 g of potassium carbonate was added to this reaction solution, and the mixture was stirred for 3 hours while heating to 110 °C with a mantle heater. The reaction solution after stirring was added dropwise to a beaker containing 1000 mL of methanol, and the precipitate formed was collected by suction filtration. The filtered precipitate was further washed three times with 300 mL of methanol to obtain 75 g of phenoxy resin a. The molecular weight of the obtained phenoxy resin a was measured using a high-performance liquid chromatograph (Tosoh Corporation, GP8020; columns: Showa Denko Materials Co., Ltd. Gelpack GL-A150S and GLA160S; eluent: tetrahydrofuran; flow rate: 1.0 mL / min). The results, in polystyrene equivalent, were Mn = 15769, Mw = 38045, and Mw / Mn = 2.413.

[0142] <Preparation of conductive particles> Conductive particles with an average particle diameter of 3.0 μm were obtained by forming a nickel layer with a thickness of 0.15 μm on the surface of cross-linked polystyrene particles.

[0143] A second adhesive composition was applied onto a substrate (PET film) to form a second adhesive layer on the substrate. Furthermore, the first adhesive composition was applied on the second adhesive layer to form a first adhesive layer, thereby creating a circuit connection adhesive film in which the first adhesive layer, the second adhesive layer, and the substrate were laminated in this order. In each of the circuit connection adhesive films in Example 1 and Comparative Examples 1-2, the thickness of the first adhesive layer was 7 μm, and the thickness of the second adhesive layer was also 7 μm.

[0144] <Fabrication of connecting structures> As the first circuit component, an alkali-free glass substrate (OA-11, manufactured by Nippon Electric Glass Co., Ltd., external dimensions: 38 mm x 28 mm, thickness: 0.3 mm) was prepared with a wiring pattern of AlNd (100 nm) / Mo (50 nm) / ITO (100 nm) formed on its surface (pattern width: 19 μm, inter-electrode spacing: 5 μm). As the second circuit component, an IC chip was prepared with bump electrodes arranged in a staggered pattern in two rows (external dimensions: 0.9 mm x 20.3 mm, thickness: 0.3 mm, bump electrode size: 70 μm x 12 μm, inter-bump electrode spacing: 12 μm, bump electrode thickness: 8 μm).

[0145] A connection structure was fabricated using the circuit connection adhesive film obtained in each example and comparative example. First, the first adhesive layer of the circuit connection adhesive film was placed on the first circuit member. A thermocompression bonding apparatus (manufactured by Ohashi Seisakusho Co., Ltd.), consisting of a ceramic heater stage and a tool (8 mm x 50 mm), was used at 60°C and 0.98 MPa (10 kgf / cm²). 2Under the conditions of ), heating and pressurizing were performed for 1 second to bond the adhesive film for circuit connection to the first circuit member. Next, the substrate on the side of the adhesive film for circuit connection opposite to the first circuit member was peeled off, and position alignment between the bump electrodes of the first circuit member and the circuit electrodes of the second circuit member was performed. Then, using a heat tool (8 mm × 45 mm), via a 50 μm-thick PTFE sheet as a buffer material, heating and pressurizing were performed at 145° C. under 60 MPa for 5 seconds on a pedestal heated to 60° C., thereby bonding the second adhesive layer of the adhesive film for circuit connection to the second circuit member to produce a connected structure. The temperature was defined as the actually measured maximum reached temperature of the adhesive film for circuit connection, and the pressure was defined as a value calculated with respect to the total area of the surface of the bump electrodes of the second circuit member facing the first circuit member.

[0146]

Table 1

[0147] <DSC Measurement> For the adhesive films for circuit connection obtained in each of the examples and comparative examples, differential scanning calorimetry (DSC) was performed using a differential scanning calorimeter (trade name: DSC2500, manufactured by TA Instruments Japan Inc.) under the conditions of a nitrogen atmosphere, a temperature increase rate of 10° C. / min, and a measurement temperature range of 40 to 300° C. From the DSC measurement results, the first occurring endothermic peak was defined as the first peak, and the endothermic peak occurring subsequent to the first peak was defined as the second peak. The presence or absence of the second peak and the area ratio of the first peak to the second peak (first peak / second peak) were calculated. Additionally, the calorific value was calculated from the area of the first peak. The calculation results are shown in Table 2.

[0148] <Evaluation of Reaction Rate> After the adhesive films for circuit connection obtained in each of the examples and comparative examples were stored in a constant temperature bath at 40° C. for 15 hours, DSC measurement was performed in the same manner as described above, and the reaction rate was calculated from the following formula using the measured calorific value. For the evaluation of the reaction rate, a reaction rate of less than 10% was rated as Evaluation A, and a reaction rate of 10% or more was rated as Evaluation B. The evaluation results are shown in Table 2. Reaction rate (%) = 100 × (1 - b / a) In the formula, a and b are as follows: a: Total heat generation of unreacted material (unit: J / g) b: Total heat generated by the reactants after heat treatment (unit: J / g)

[0149] <Measurement of elastic modulus> Using the adhesive compositions obtained in each example and comparative example, laminates were prepared so that the layer formed by the first adhesive composition and the layer formed by the second adhesive composition were of the same thickness, with a total thickness of 100-200 μm. These laminates were then heated in an oven at 180°C for 1 hour to produce a cured film for evaluation. Subsequently, the cured film was subjected to DMA measurements from 40 to 350°C using a dynamic viscoelasticity analyzer (product name: E-4000) manufactured by UBM Co., Ltd., at a heating rate of 10°C / min, and the storage modulus at 300°C was calculated.

[0150] <Evaluation of connection resistance> Using a connection structure, the connection resistance at 14 locations was measured using the four-terminal measurement method, and the maximum value of the connection resistance after the high-temperature and high-humidity test was evaluated. The high-temperature and high-humidity test was performed by storing the connection structure for 250 hours in constant temperature and humidity chambers set to 110°C and 85%RH, 85°C and 85%RH, and 65°C and 95%RH, respectively. A multimeter (MLR21, ETAC Corporation) was used to measure the connection resistance. The connection resistance was evaluated as follows: less than 1Ω was rated A, 1Ω or more and less than 2Ω was rated B, and 2Ω or more was rated C. The evaluation results are shown in Table 2.

[0151] <Evaluation of corrosion resistance using artificial sweat solution> After storing the connection structures, which had been immersed in artificial sweat solution, in a constant temperature and humidity chamber at 55°C and 93% RH for 72 hours, the wiring sections of the connection structures were observed under a microscope to check for corrosion. Corrosion was considered to have occurred if corrosion was observed in more than 5% of the total area of ​​the wiring section. For the evaluation of corrosion resistance, the corrosion occurrence rate at a total of 35 locations was calculated by observing seven wiring sections of each of the five connection structures under a microscope. The calculation results are shown in Table 2.

[0152] [Table 2] [Explanation of Symbols]

[0153] 1... Adhesive film for circuit connection, 1A... First adhesive layer, 1B... Second adhesive layer, 2, 2A, 2B... Adhesive components, 3, 3A... Conductive particles, 4... First circuit member, 5... Second circuit member, 6... Connection part, 7... Insulating material, 10... Structure, 41... First circuit board, 42... First electrode, 51... Second circuit board, 52... Second electrode.

Claims

1. It contains a cationic polymerizable compound and a curing agent, An adhesive composition wherein the curing agent is a salt of a nitrogen-containing cation and an anion represented by the following general formula (1). 【Chemistry 1】 [In formula (1), R １ [where m represents a fluoroalkyl group, a fluoroaryl group, or a fluoroalkyl-substituted aryl group, m represents 0 or 1, and n represents an integer from 1 to 4.]

2. The adhesive composition according to claim 1, wherein the nitrogen-containing cation is an ammonium cation, anilinium cation, or pyridinium cation.

3. The adhesive composition according to claim 1, wherein the content of the curing agent is more than 5 parts by mass and 40 parts by mass or less, based on 100 parts by mass of the cationic polymerizable compound.

4. The adhesive composition according to claim 1, further containing conductive particles.

5. The adhesive composition according to claim 4, wherein the content of the curing agent is 5 to 30 parts by mass based on 100 parts by mass of the conductive particles.

6. The adhesive composition according to claim 1, further comprising an amide having a lactam ring.

7. The adhesive composition according to claim 6, wherein the content of the curing agent is 1 to 20 parts by mass, based on 0.01 parts by mass of the lactam ring-containing amide.

8. The adhesive composition according to claim 1, wherein the cationic polymerizable compound comprises an epoxy compound.

9. When differential scanning calorimetry (DSC) is performed under nitrogen atmosphere conditions, with a heating rate of 10°C / min, and a measurement temperature range of 40-300°C, multiple endothermic peaks are generated, and the ratio of the first endothermic peak (first peak) to the second endothermic peak (second peak) (first peak / second peak) is 3 or greater, or The adhesive composition according to claim 1, wherein one endothermic peak is generated.

10. The adhesive composition according to claim 1, wherein the reaction rate when heat-treated at 40°C for 15 hours is 10% or less.

11. The adhesive composition according to claim 1, wherein the elastic modulus of the reactant obtained by heating at 180°C for 1 hour is 0.1 GPa or more at 300°C.

12. A circuit connection adhesive film comprising an adhesive layer formed by the adhesive composition according to any one of claims 1 to 11.

13. A circuit connection adhesive film comprising an adhesive layer formed by the adhesive composition according to claim 4 or 5, A circuit connection adhesive film in which the conductive particles are arranged in a predetermined pattern when viewed in plan view of the circuit connection adhesive film.

14. It comprises a first adhesive layer and a second adhesive layer laminated on the first adhesive layer, A circuit connection adhesive film in which at least one of the first adhesive layer and the second adhesive layer is a layer formed by the adhesive composition described in any one of claims 1 to 11.

15. A first circuit member having a first electrode, A second circuit member having a second electrode, A connecting portion is provided between the first circuit member and the second circuit member, and electrically connects the first electrode and the second electrode to each other. Equipped with, A connection structure wherein the connection portion includes a cured product of the circuit connection adhesive film described in claim 12.

16. A method for manufacturing a connection structure, comprising the steps of interposing a circuit connection adhesive film according to claim 12 between a first circuit member having a first electrode and a second circuit member having a second electrode, and then heat-pressing the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other.

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