WO2023136286A1

WO2023136286A1 - Adhesive composition, adhesive film for circuit connection, and method for producing connection structure

Info

Publication number: WO2023136286A1
Application number: PCT/JP2023/000595
Authority: WO
Inventors: 敏光森谷; 裕太山崎; 和憲石川; 亮太小林; つばさ伊藤
Original assignee: 株式会社レゾナック; シーカ・ハマタイト株式会社
Priority date: 2022-01-12
Filing date: 2023-01-12
Publication date: 2023-07-20
Also published as: TW202341186A; WO2023136274A1; TW202336201A; WO2023136272A1; WO2023136273A1

Abstract

An adhesive composition that contains (A) an epoxy resin and (B) a curing agent, in which a pyridinium salt is included as the (B) component, the pyridinium salt includes a pyridinium cation and an anion, the pyridinium cation has a benzyl group at the 1-position and an electron-attracting group at the 2-position, the benzyl group has an electron-donating group, and the anion is B(C6F5)4 - or B(C6H3(CF3)2)4 - (wherein the CF3 group is substituted at the 3- and 5-positions of a phenyl group).

Description

ADHESIVE COMPOSITION, ADHESIVE FILM FOR CIRCUIT CONNECTION, AND METHOD FOR MANUFACTURING CONNECTED STRUCTURE

The present disclosure relates to an adhesive composition, an adhesive film for circuit connection, and a method for manufacturing a connection structure.

As a circuit connection material that heats and presses opposing circuit members to electrically connect electrodes in the direction of pressure, for example, an adhesive for circuit connection having anisotropic conductivity in which conductive particles are dispersed in the adhesive. Films are known (see, for example, Patent Documents 1 to 4 below). Such an adhesive film is used for connection between a liquid crystal display (LCD) panel and a tape carrier package (TCP: Tape Carrier Package) or a chip on flex (COF: Chip On Flex) on which a semiconductor for driving the LCD is mounted, Alternatively, it is widely used for electrical connection between a printed wiring board and TCP or COF.

Recently, even when semiconductors are directly mounted face-down on LCD panels or printed wiring boards, flip-chip mounting, which is advantageous for thinning and narrow-pitch connection, has been adopted instead of the conventional wire bonding method. A circuit-connecting adhesive film having anisotropic conductivity is used as a circuit-connecting material.

JP-A-60-191228 JP-A-1-251787 JP-A-7-90237 JP 2019-104869 A

In recent years, from the viewpoint of display weight reduction and design, the frame of the display has become narrower, and the demand for products with almost no display frame, such as smartphones, is increasing. In addition, the locations where electronic components such as driver ICs and TCP for driving displays are mounted are becoming narrower, and especially in displays with a narrow frame, electronic components are sometimes mounted in the vicinity of the display section. If the members of the display section have low heat resistance, the members of the display section may be damaged by the heat generated during the mounting of the electronic components. Therefore, there is a need for adhesive compositions that can be cured at low temperatures. Moreover, from the viewpoint of improving production efficiency, it is required to cure the adhesive composition at a lower temperature.

Furthermore, in recent years, the level of demand for panel quality reliability has increased from the market. Therefore, it is necessary to realize excellent connection resistance.

Therefore, an object of the present disclosure is to provide an adhesive composition that can be cured at a low temperature (115°C) and that can achieve excellent connection resistance. Another object of the present disclosure is to provide an adhesive film for circuit connection, a connection structure, and a method for producing a connection structure using the adhesive composition. Another object of the present disclosure is to provide a pyridinium salt used in the adhesive composition.

One aspect of the present disclosure includes the following [1] to [7].
[1] containing (A) an epoxy resin and (B) a curing agent,
As the component (B), a pyridinium salt is included,
The pyridinium salt comprises a pyridinium cation and an anion,
the pyridinium cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position;
the benzyl group has an electron donating group,
the anion is B(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (provided that CF ₃ groups are substituted at the 3,5-positions of the phenyl group); adhesive composition.
[2] The adhesive composition according to [1], further containing conductive particles.
[3] An adhesive film for circuit connection, having a region formed from the adhesive composition according to [1] or [2].
[4] comprising a first region containing a first adhesive component and a second region containing a second adhesive component provided adjacent to the first region;
An adhesive film for circuit connection, wherein one or both of the first region and the second region are formed from the adhesive composition according to [1] or [2].
[5] a first circuit member having a first electrode;
a second circuit member having a second electrode;
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;
with
A connection structure, wherein the connection part contains a cured product of the circuit connection adhesive film according to [3] or [4].
[6] Between the first circuit member having the first electrode and the second circuit member having the second electrode, the adhesive film for circuit connection according to [3] or [4] is interposed. and thermocompression bonding the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other.
[7] A pyridinium salt containing a pyridinium cation and an anion,
the pyridinium cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position;
the benzyl group has an electron donating group,
the anion is B(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (provided that CF ₃ groups are substituted at the 3,5-positions of the phenyl group); pyridinium salt.

According to the present disclosure, it is possible to provide an adhesive composition that can be cured at a low temperature (115°C) and that can achieve excellent connection resistance. Further, according to the present disclosure, it is possible to provide an adhesive film for circuit connection, a connection structure, and a method for producing a connection structure using the adhesive composition. Also, according to the present disclosure, it is possible to provide a pyridinium salt for use in the adhesive composition.

1 is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection; FIG. 1 is a schematic cross-sectional view showing an embodiment of an adhesive film for circuit connection; FIG. It is a schematic cross section which shows one Embodiment of a connection structure. FIG. 4 is a schematic cross-sectional view showing a method of manufacturing the connection structure of FIG. 3; 4 shows the DSC measurement results of the circuit-connecting adhesive film of Example 1. FIG. 4 shows the DSC measurement results of the circuit-connecting adhesive film of Example 1. FIG. 4 shows the DSC measurement results of the circuit-connecting adhesive film of Example 2. FIG. 4 shows the DSC measurement results of the circuit-connecting adhesive film of Example 2. FIG.

Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments.

In the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the values shown in the examples. Also, the lower and upper limits of a numerical range can be arbitrarily combined with the lower and upper limits of other numerical ranges, respectively. In the notation of a numerical range “A to B”, both numerical values A and B are included in the numerical range as lower and upper limits, respectively. In this specification, for example, the description "10 or more" means 10 and a numerical value exceeding 10, and this also applies when the numerical values are different. Further, for example, the description "10 or less" means 10 and less than 10, and the same applies when the numerical values are different. In addition, each component and material exemplified in this specification may be used singly or in combination of two or more unless otherwise specified. As used herein, the content of each component in the composition refers to the total amount of the multiple substances present in the composition when there are multiple substances corresponding to each component in the composition, unless otherwise specified. means Moreover, in this specification, "(meth)acrylate" means at least one of acrylate and methacrylate corresponding thereto. Further, in this specification, the term "epoxy group" includes a substituent containing an epoxy group in its structure, such as a glycidyl group and a glycidyloxy group.

<Adhesive composition>
The adhesive composition of the present embodiment contains at least (A) an epoxy resin (hereinafter also referred to as (A) component) and (B) a curing agent (hereinafter also referred to as (B) component).

(Epoxy resin)
The adhesive composition of the present embodiment may contain, as the component (A), for example, an aromatic epoxy resin exceeding 90% by mass based on the total amount of the component (A), and as the aromatic epoxy resin, for example, ( A1) A polyfunctional epoxy resin having a skeleton represented by the following general formula (1) (hereinafter also referred to as component (A1)) may be included.

In formula (1), X ¹ represents an oxygen atom, a sulfur atom, or an alkylene group having 1 to 10 carbon atoms. From the viewpoint of peeling resistance, X ¹ may be -CH ₂ -.

(Epoxy resin)
First, the (A1) component will be described.

As the component (A1), a polyfunctional epoxy resin represented by the following general formula (2) can be used.

[In formula (2 ⁾ , X ¹ represents an oxygen atom, a sulfur atom, or an alkylene group having 1 to ¹⁰ carbon atoms; group, m and n each represent an integer of 1 to 7, and m+n is 2 or more. ]

From the viewpoint of peel resistance, a polyfunctional epoxy resin represented by the following general formula (3) can be used as the component (A1).

[In Formula (3), R ¹¹ , R ¹² , R ²¹ and R ²² each independently represent a hydrogen atom, a glycidyl group or a glycidyloxy group, and two of R ¹¹ , R ¹² , R ²¹ and R ²² The above is a glycidyl group or a glycidyloxy group. ]

In formula (3), R ¹¹ and R ²² are a glycidyl group or a glycidyloxy group, R ¹² and R ²¹ may be hydrogen atoms, and all of R ¹¹ , R ¹² , R ²¹ and R ²² are glycidyl or a glycidyloxy group.

Commercially available products such as "HP4700" and "HP4770" (manufactured by DIC Corporation, trade names) can be used as the (A1) component.

The (A1) component can be used singly or in combination of two or more.

The adhesive composition of the present embodiment can contain a second aromatic epoxy resin (hereinafter also referred to as (A2) component) other than the (A1) component.

As the second aromatic epoxy resin, bisphenol A type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, tetramethyl Bisphenol A type epoxy resin, 3′,4′-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate (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 the like. The second aromatic epoxy resin is at least one selected from the group consisting of bisphenol A type epoxy resin, tetramethylbisphenol A type epoxy resin, dicyclopentadiene dimethanol diglycidyl ether, and xylene-novolac type glycidyl ether. good.

From the viewpoint of making it easier to achieve excellent connection resistance even after the HAST test, a polyfunctional epoxy resin (an epoxy resin having a trisphenolmethane structure) represented by the following general formula (7) is used as the component (A2). be able to.

[In formula (7), R ⁷¹ , R ⁷² and R ⁷³ each independently represent a hydrogen atom or an organic group, and at least one of R ⁷¹ , R ⁷² and R ⁷³ is an epoxy represents an organic group having a group, ^R74 represents a hydrogen atom or an alkyl group, and ^R75 represents a hydrogen atom or an organic group. ]

Examples of organic groups represented by R ⁷¹ , R ⁷² and R ⁷³ include alkyl groups, alkyl ether groups and alkenyl groups. These organic groups may have a substituent. The number of carbon atoms in the organic group may be, for example, 2 or more, or 3 or more, or 8 or less, 6 or less, or 4 or less. At least one of R ⁷¹ , R ⁷² and R ⁷³ may be an organic group having a glycidyl group or an organic group having a glycidyloxy group. R ⁷¹ , R ⁷² and R ⁷³ may be the same or different. R ⁷¹ , R ⁷² , and R ⁷³ may all be an organic group having a glycidyl group, or an organic group having a glycidyloxy group, from the viewpoint of more easily realizing excellent connection resistance even after the HAST test. There may be.

When R ⁷⁴ is an alkyl group, the alkyl group can be, for example, a methyl group, an ethyl group, or a propyl group. The alkyl group may have a substituent. ^R74 may be a hydrogen atom from the viewpoint of easily achieving excellent connection resistance even after the HAST test.

The organic group represented by R ⁷⁵ may be, for example, an alkyl group, an alkyl ether group, or an alkenyl group. The organic group may have a substituent. R ⁷⁵ may be an alkyl group, an alkyl group having a substituent, or an alkyl having a phenyl group from the viewpoint of more easily realizing excellent connection resistance even after the HAST test. good. A phenyl group may have a substituent, for example, an epoxy group, a glycidyl group, or a glycidyloxy group. ^R75 may be an alkyl group having a phenyl group having a glycidyloxy group from the viewpoint of more easily achieving excellent connection resistance even after the HAST test.

The number of epoxy groups possessed by the polyfunctional epoxy resin represented by formula (7) 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.

The epoxy equivalent of the polyfunctional epoxy resin represented by formula (7) may be, for example, 100-300 g/eq, or 150-250 g/eq. Epoxy equivalent means a value measured according to JIS K7236.

Specifically, the polyfunctional epoxy resin represented by Formula (7) may be a compound represented by Formula (7A) below.

[In formula (7A), n represents an integer of 1 to 3. ]

The adhesive composition of the present embodiment may contain other epoxy resins than the aromatic epoxy resin as the (A) component. Other epoxy resins include aliphatic epoxy resins and cycloaliphatic epoxy resins. From the viewpoint of further improving low-temperature curability, the component (A) may contain an alicyclic epoxy resin. Moreover, from the viewpoint of easily achieving both low-temperature curability and good storage stability, the component (A) does not need to contain an alicyclic epoxy resin.

The adhesive composition of the present embodiment may contain a resin other than the epoxy resin, for example, it may contain a cationically polymerizable compound in addition to the epoxy resin. Examples of cationic polymerizable compounds include oxetane compounds. The adhesive composition of the present embodiment may use a cationic polymerizable compound instead of the epoxy resin. That is, another embodiment of the present disclosure contains a cationic polymerizable compound and a curing agent, the curing agent contains a pyridinium salt, the pyridinium salt contains a pyridinium cation and an anion, and pyridinium the cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position, the benzyl group has an electron-donating group, and the anion is B(C ₆ F ₅ ) ₄ ⁻ , or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (provided that the CF ₃ group is substituted at the 3,5-position of the phenyl group) is an adhesive composition.

Examples of oxetane compounds include xylylenebisoxetane, 2-ethylhexyloxetane, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxy methyl-3-n-butyloxetane, 3-hydroxymethyl-3-phenyloxetane, 3-hydroxymethyl-3-benzyloxetane, 3-hydroxyethyl-3-methyloxetane, 3-hydroxyethyl-3-ethyloxetane, 3- Hydroxyethyl-3-propyloxetane, 3-hydroxyethyl-3-phenyloxetane, 3-hydroxypropyl-3-methyloxetane, 3-hydroxypropyl-3-ethyloxetane, 3-hydroxypropyl-3-propyloxetane, 3- Hydroxypropyl-3-phenyloxetane, 3-hydroxybutyl-3-methyloxetane, 4,4′-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, and 3-ethyl-3{[(3- ethyloxetan-3-yl)methoxy]methyl}oxetane and the like.

From the viewpoint of ensuring the curability of the adhesive composition, the content of component (A) is 10% by mass or more, 20% by mass or more, 30% by mass or more, or 35% by mass or more, based on the total mass of the adhesive composition. % by mass or more. From the viewpoint of ensuring the formability of the adhesive composition, the content of component (A) is 70% by mass or less, 60% by mass or less, 50% by mass or less, or 45% by mass or less, based on the total mass of the adhesive composition. % by mass or less.

The content of the component (A) is 50% by mass or more based on the total mass of the cationically polymerizable compound, from the viewpoint of making it easier to achieve an excellent appearance even after the HAST test and from the viewpoint of better sticking properties. It may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more. The content of component (A) in the cationically polymerizable compound may be substantially 100% by mass (an embodiment in which the cationically polymerizable compound is composed of component (A)).

The content of the polyfunctional epoxy resin represented by the formula (7) in the component (A) is, from the viewpoint of easily realizing an excellent appearance even after the HAST test and from the viewpoint of better adhesion, the content of the (A) It may be 20% or more, 30% or more, 40% or more, or 45% or more by weight based on the total weight of the ingredients. The content of the polyfunctional epoxy resin represented by formula (7) in component (A) is 80% by mass or less, 70% by mass or less, 60% by mass or less, or 55% by mass, based on the total mass of component (A). % by mass or less.

(curing agent)
The adhesive composition of the present embodiment contains (B1) an onium-based compound (hereinafter also referred to as (B1) component) as the (B) component.

As component (B1), onium salts such as sulfonium salts, pyridinium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts can be used. Onium salt anions include BF ₄ ⁻ , BR ₄ ⁻ (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ^- and the like.

The (B1) component can be used singly or in combination of two or more.

From the viewpoint of low-temperature curability, the (B1) component may be a pyridinium salt or a sulfonium salt.

As the pyridinium salt, a pyridinium salt having a benzyl group at the 1-position, an electron-withdrawing group at the 2-position, and the benzyl group having an electron-donating group (hereinafter also referred to as "pyridinium salt A") is used. be able to. In other words, pyridinium salt A has a pyridine ring and a benzene ring, with an electron-withdrawing group located ortho to the nitrogen atom of the pyridine ring, with the benzene ring having an electron-donating group.

The pyridinium salt A may be a compound composed of a pyridinium cation and an anion. In addition, in this specification, the 1-position of a pyridinium salt or a pyridinium cation means the position of the nitrogen atom in the pyridine ring of a pyridinium salt or a pyridinium cation.

Pyridinium salt A may be, for example, a compound represented by the following general formula (4).

[In formula (4), R ³¹ represents an electron-withdrawing group, R ³² represents an electron-donating group, and X ^- represents an anion. ]

Examples of the electron-withdrawing group that the pyridinium salt A has at the 2-position include a cyano group, a halogeno group, a nitro group, a carbonyl group, a carboxy group, a sulfo group, and the like. The halogeno group includes a fluoro group, a chloro group, a bromo group, an iodo group and the like. The electron-withdrawing group may be a cyano group or a halogeno group, or a cyano group or a chloro group, from the viewpoint of enhancing the activity of the curing agent and curing the adhesive composition in a shorter time. good. Pyridinium salt A may contain an electron withdrawing group other than the voltage withdrawing group located at the 2-position. The number of electron-withdrawing groups that the pyridinium salt A has may be 3 or less, 2 or less, or 1.

Examples of the electron-donating group of the benzyl group located at the 1-position of the pyridinium salt A include an alkyl group, an alkoxy group, a hydroxyl group, an amino group, and an alkylamino group. The alkyl group includes methyl group, ethyl group, normal propyl group, isopropyl group and the like. The alkoxy group includes a methoxy group, an ethoxy group, and the like. The electron-withdrawing group may be an alkyl group or an alkoxy group, or may be a methyl group or a methoxy group, from the viewpoint of increasing the activity of the curing agent and curing the adhesive composition in a shorter time. . The benzene ring may contain a plurality of electron-donating groups, and the number of electron-donating groups possessed by the benzyl group located at the 1-position of the pyridinium salt A may be 1 or more, 2 or more, or 3 or more. The benzyl group placed at the 1-position of pyridinium salt A is the 4-position (4-position when the bonding position of the benzyl group to the pyridine ring is the 1-position. The para-position to the bonding position of the benzyl group to the pyridine ring ) may have at least one electron donating group.

When the number of electron-donating groups possessed by the benzyl group located at the 1-position of pyridinium salt A is 3, any of the three electron-donating groups may be an alkyl group or a methyl group. . The pyridinium salt A may have an alkyl group as an electron donating group at each of the 2-, 4- and 6-positions of the benzyl group when the bonding position of the benzyl group to the pyridine ring is the 1-position. The curing agent contains a pyridinium salt in which the benzyl group located at the 1-position of the pyridinium salt A has 3 electron-donating groups, and the electron-donating groups are all alkyl groups (or methyl groups), An adhesive film using such a curing agent has excellent physical properties (eg, elastic modulus). Therefore, an adhesive film using such a curing agent can achieve, for example, both excellent adhesion to circuit members and excellent releasability of the base material from the adhesive film. In addition, the adhesive film using such a curing agent, for example, has excellent storage stability, and even when the adhesive film is stored for a certain period of time (for example, 15 hours at 40 ° C.), it is excellent for circuit members. It is easy to maintain good adhesion and excellent releasability of the substrate from the adhesive film. The reason for this is that the number of electron-donating groups of the benzyl group located at the 1-position of the pyridinium salt A is 3, so that the low-temperature curability can be maintained for a certain period of time (for example, 15 hours at 40° C.). This is thought to be due to the well-balanced structure that prevents deterioration during storage (excellent storage stability).

Pyridinium cations of pyridinium salt A include 2-cyano-1-(4-methoxybenzyl)pyridinium cation, 2-chloro-1-(4-methoxybenzyl)pyridinium cation, 2-bromo-1-(4-methoxybenzyl) ) pyridinium cation, 2-cyano-1-(4-methylbenzyl)pyridinium cation, 2-chloro-1-(4-methylbenzyl)pyridinium cation, 2-bromo-1-(4-methylbenzyl)pyridinium cation, 2 -cyano-1-(2,4,6-trimethylbenzyl)pyridinium cation, 2-chloro-1-(2,4,6-trimethylbenzyl)pyridinium cation, 2-bromo-1-(2,4,6- trimethylbenzyl)pyridinium cation and the like. The pyridinium cation of pyridinium salt A is 2-cyano-1-(4-methoxybenzyl) pyridinium cation, 2-chloro-1-(4-methoxy at least selected from the group consisting of benzyl)pyridinium cation, 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium cation, and 2-chloro-1-(2,4,6-trimethylbenzyl)pyridinium cation may be of one type.

The anions of pyridinium salt A are SbF ₆ ⁻ , PF ₆ ⁻ , PF _X (CF ₃ ) _6-X ⁻ (where X is an integer of 1 to 5), BF ₄ ⁻ , B(C ₆ F ₅ ) ₄ ⁻ , RSO ₃ ⁻ (where R is an alkyl group having 1 to 3 carbon atoms or a substituted or unsubstituted aryl group), C(SO ₂ CF ₃ ) ₃ ⁻ , B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ^- (wherein CF ₃ groups are substituted at the 3,5-positions of the phenyl group; tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion) and the like. The anion of pyridinium salt A is B(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (where CF ₃ groups may be substituted at the 3,5 positions of the phenyl group). That is, another embodiment of the present disclosure is a pyridinium salt comprising a pyridinium cation and an anion, wherein the pyridinium cation has a benzyl group at the 1-position and an electron withdrawing group at the 2-position. and the benzyl group has an electron donating group, and the anion is BB(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (wherein the CF ₃ group is phenyl It is a pyridinium salt that is substituted at the 3,5-position of the group). Further, when the anion of pyridinium salt A is B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (provided that CF ₃ groups are substituted at the 3,5-positions of the phenyl group), the anion of pyridinium salt A is B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (wherein CF ₃ groups are substituted at the 3 and 5-positions of the phenyl group) achieves excellent connection resistance after the HAST test. easier.

The pyridinium salt A may be a compound in which the above pyridinium cation and the above anion are combined. Pyridinium salt A is 2-cyano-1-(4-methoxybenzyl)pyridinium tetrakis(pentafluorophenyl)borate, 2-chloro-1- (4-Methoxybenzyl)pyridinium tetrakis(pentafluorophenyl)borate, 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium tetrakis(pentafluorophenyl)borate, 2-chloro-1-(2 ,4,6-trimethylbenzyl)pyridinium tetrakis(pentafluorophenyl)borate, 2-cyano-1-(4-methoxybenzyl)pyridinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, 2- Chloro-1-(4-methoxybenzyl)pyridinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium tetrakis(3, from the group consisting of 5-bis(trifluoromethyl)phenyl)borate and 2-chloro-1-(2,4,6-trimethylbenzyl)pyridinium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate It may be at least one selected.

The adhesive composition of the present embodiment contains a pyridinium cation and an anion as component (B), wherein the pyridinium cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position. and the benzyl group has an electron-donating group, and the anion is B(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (wherein the CF ₃ group is a phenyl group substituted at the 3,5-positions of (hereinafter also referred to as "pyridinium salt A1"). With such pyridinium salt A1, the adhesive composition can be cured at a low temperature (115° C.), and excellent connection resistance can be achieved. That is, another embodiment of the present disclosure is a pyridinium salt comprising a pyridinium cation and an anion, wherein the pyridinium cation has a benzyl group at the 1-position and an electron withdrawing group at the 2-position. and the benzyl group has an electron donating group, and the anion is B(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (wherein the CF ₃ group is phenyl It is a pyridinium salt that is substituted at the 3,5-position of the group).

Another embodiment of the present disclosure is a curing agent containing pyridinium salt A1. The content of pyridinium salt A1 in the curing agent may be 80% by mass or more, 90% by mass or more, or 95% by mass or more, based on the total mass of the curing agent, and may be 100% by mass (substantially the curing agent is composed of pyridinium salt A1).

The curing agent may contain a pyridinium salt other than pyridinium salt A1 (hereinafter this pyridinium salt is also referred to as "pyridinium salt B") and an onium compound other than pyridinium salt (for example, a sulfonium salt described later).

Pyridinium salt B includes, for example, a pyridinium cation having a benzyl group at the 1-position and an electron-withdrawing group at the 2-position, the benzyl group having an electron-donating group, and SbF ₆ ⁻ , PF ₆ ⁻ , PF _X (CF ₃ ) _6-X ⁻ (where X is an integer of 1 to 5), BF ₄ ⁻ , RSO ₃ ⁻ (where R is an alkyl group having 1 to 3 carbon atoms, or a substituted or unsubstituted aryl group) , C(SO ₂ CF ₃ ) ₃ ^- , N(SO ₂ CF ₃ ) ₂ ^- , and at least one anion selected from the group consisting of O(SO ₂ CF ₃ ) ^- good.

Pyridinium salt B has, for example, a borate ion having a 3,5-bis(trifluoromethyl)phenyl structure as an anion (excluding tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion). It may be a pyridinium salt (hereinafter also referred to as "pyridinium salt B1"). By including pyridinium salt B1, the curing agent can achieve excellent connection resistance even after the HAST test. The anion of pyridinium salt B1 may have, for example, a structure represented by the following general formula (6).

[In Formula (6), R ⁶³ , R ⁶⁴ and R ⁶⁵ each independently represent a monovalent organic group, and a, b and c each independently represent an integer of 0 to 3. However, tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion is excluded. ]

R ⁶³ , R ⁶⁴ and R ⁶⁵ are each independently, for example, a methyl group, an ethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a pentafluoromethyl group, and a perfluoroalkyl group. good. Any of R ⁶³ , R ⁶⁴ and R ⁶⁵ may be a trifluoromethyl group from the viewpoint of easily achieving excellent connection resistance even after the HAST test.

a, b, and c may each independently be 1 or more, 2 or more, or 2 or less. Each of a, b, and c may be 2 from the viewpoint of stabilizing the structure of pyridinium salt A. When a, b, and c are 1, R ⁶³ , R ⁶⁴ , and R ⁶⁵ are at the 4-position (4-position when the bonding position of the benzyl group to boron is the 1-position. position), and the trifluoromethyl group may be placed at the 4-position of the benzyl group. When a, b, and c are 2, R ⁶³ , R ⁶⁴ , and R ⁶⁵ are at the 3-position and 5-position (3-position and 5-position when the bonding position of the benzyl group to boron is the 1-position. (meta-position relative to the bonding position of the group to boron).

When the curing agent contains pyridinium salt A1 and pyridinium salt B, the ratio of the content of pyridinium salt A1 to the content of pyridinium salt B in the curing agent (content of pyridinium salt A1 / content of pyridinium salt B) is It may be 0.1 or more, 0.2 or more, or 0.5 or more, and may be 10 or less, 5 or less, or 2 or less.

The curing agent containing pyridinium salt A1 is, for example, at least one of a pyridine compound having an electron-withdrawing group at the 2-position, a benzyl chloride compound having an electron-donating group, or a benzyl bromide compound having an electron-donating group, and an alkali metal A step of reacting an iodide salt (e.g., sodium iodide) of (e.g., sodium iodide) in a solvent (e.g., acetonitrile) to obtain a pyridinium iodide having a pyridine ring and a benzene ring; (for example, dichloromethane) to obtain pyridinium salt A1.

The pyridine compound having an electron withdrawing group at the 2-position may be a pyridine compound having the above electron withdrawing group at the 2-position, such as 2-cyanopyridine and 2-chloropyridine.

The benzyl chloride compound having an electron donating group may be the above benzyl chloride compound having an electron donating group, such as 4-methoxybenzyl chloride and 2,4,6-trimethylbenzyl chloride. The benzyl bromide compound having an electron donating group may be the benzyl bromide compound having an electron donating group as described above, such as 4-methoxybenzyl bromide and 2,4,6-trimethylbenzyl bromide.

_The anion salt may be _any ^compound _capable of introducing the anion possessed by _the pyridinium salt A1 _. It may be a lithium salt, sodium salt, potassium salt or cesium salt of (CF ₃ ) ₂ ) ₄ ⁻ (wherein the CF ₃ groups are substituted at the 3,5-positions of the phenyl group).

In the step of obtaining pyridinium iodide, the reaction may be carried out, for example, at room temperature (20-30°C). The reaction time can be, for example, 10-50 hours or 20-30 hours. After completion of the reaction, the solvent used may be removed by washing the resulting pyridinium iodide with acetone, distilled water, or the like, and vacuum drying.

In the step of obtaining pyridinium iodide, the yield of pyridinium iodide may be 40% or higher, 55% or higher, 70% or higher, or 80% or higher. The yield of pyridinium iodide is the ratio of the amount actually obtained to the maximum amount of pyridinium iodide obtainable from the raw materials used in the synthesis of pyridinium iodide.

In the step of obtaining pyridinium salt A1, the reaction may be carried out, for example, at room temperature (20-30°C). The reaction time can be, for example, 1-15 hours or 1-5 hours. After completion of the reaction, the solvent used may be removed by washing the resulting pyridinium salt A1 with acetone, distilled water, or the like, and drying it under vacuum.

In the step of obtaining pyridinium salt A1, the yield of pyridinium salt A1 may be 70% or more, 80% or more, or 85% or more. The yield of pyridinium salt A1 is the ratio of the amount actually obtained to the maximum amount of pyridinium salt A1 obtainable from the pyridinium iodide used in the synthesis of pyridinium salt A1.

The fact that pyridinium salt A1 was obtained can be confirmed by measuring the obtained compound by nuclear magnetic resonance spectroscopy ( ¹ H-NMR). Specifically, it can be confirmed by the method described in Examples below.

The curing agent may contain, for example, a sulfonium salt represented by the following general formula (5).

[In the formula (5), R ⁴¹ represents a phenyl group, a 1-naphthyl group, a 2-naphthyl group, or a phenyl group having a substituent at the o, m, or p position, and R ⁴² and R ⁴³ are electron donating group and ^Y- represents an anion. ]

Examples of substituents of a phenyl group having a substituent include a methyl group, a cyano group, a halogeno group, a nitro group, an acetyl group, a carbonyl group, a carboxy group, and a sulfo group. The halogeno group includes a fluoro group, a chloro group, a bromo group, an iodo group and the like.

Examples of electron-donating groups include amino groups, hydroxyl groups, and methyl groups.

Y ⁻ includes SbF ₆ ⁻ , PF ₆ ⁻ , PF _X (CF ₃ ) _6-X ⁻ (where X is an integer of 1 to 5), BF ₄ ⁻ , B(C ₆ F ₅ ) ₄ ⁻ , RSO ₃ ^- (wherein R is an alkyl group having 1 to 3 carbon atoms, or a substituted or unsubstituted aryl group), C(SO ₂ CF ₃ ) ₃ ^- , B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ^- ( However, the CF ₃ group is substituted at the 3,5-position of the phenyl group) and the like.

As the sulfonium salt, commercially available products such as 1-naphthylmethylmethyl-p-hydroxyphenylsulfonium hexafluoroantimonate (manufactured by Sanshin Chemical Industry Co., Ltd., trade name "San-Aid SI-60") can be used.

From the viewpoint of sufficiently promoting the curing reaction, the content of component (B) in the adhesive composition is 1% by mass or more, 2% by mass or more, 3% by mass or more, based on the total mass of the adhesive composition. It may be 4% by mass or more, or 5% by mass or more. From the viewpoint of improving the physical properties of the cured product, the content of component (B) in the adhesive composition is 20% by mass or less, 15% by mass or less, 10% by mass or less, based on the total mass of the adhesive composition. It may be 8% by mass or less, or 6% by mass or less. From these viewpoints, the content of component (B) in the adhesive composition may be 1 to 20% by mass based on the total mass of the adhesive composition. The content of pyridinium salt A1 in the adhesive composition may be within the above range.

From the viewpoint of sufficiently accelerating the curing reaction, the content of the component (B) in the adhesive composition is 1% by mass or more, 3% by mass or more, 5% by mass or more, based on the total mass of the adhesive composition excluding the conductive particles. % by mass or more, or 7% by mass or more. From the viewpoint of improving the physical properties of the cured product, the content of the component (B) in the adhesive composition is 30% by mass or less, 25% by mass or less, 20% by mass or less, based on the total mass of the adhesive composition excluding the conductive particles. % by mass or less, 15% by mass or less, or 10% by mass or less. From these points of view, the content of component (B) in the adhesive composition may be 1 to 30% by mass based on the total mass of the adhesive composition excluding the conductive particles. The content of pyridinium salt A1 in the adhesive composition may be within the above range.

From the viewpoint of sufficiently accelerating the curing reaction, the content of component (B) in the adhesive composition is 1% by mass or more and 3% by mass, based on the total mass of the adhesive composition excluding conductive particles and fillers. 5% by mass or more, or 7% by mass or more. From the viewpoint of improving the physical properties of the cured product, the content of component (B) in the adhesive composition is 30% by mass or less and 25% by mass, based on the total mass of the adhesive composition excluding conductive particles and fillers. Below, it may be 20 mass % or less, 15 mass % or less, or 10 mass % or less. From these viewpoints, the content of component (B) in the adhesive composition may be 1 to 30% by mass based on the total mass of the adhesive composition excluding the conductive particles and filler. The content of pyridinium salt A1 in the adhesive composition may be within the above range.

From the viewpoint of sufficiently accelerating the curing reaction, the content of component (B) in the adhesive composition is 1 part by mass or more, 5 parts by mass or more, 8 parts by mass or more, based on 100 parts by mass of component (A). It may be 10 parts by mass or more, or 12 parts by mass or more. From the viewpoint of improving the physical properties of the cured product, the content of component (B) in the adhesive composition is 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, based on 100 parts by mass of component (A). It may be 18 parts by mass or less, or 16 parts by mass or less. From these points of view, the content of component (B) in the adhesive composition may be 1 to 40 parts by mass based on 100 parts by mass of component (A). The content of pyridinium salt A1 in the adhesive composition may be within the above range.

(film-forming component)
The adhesive composition of the present embodiment may contain a thermoplastic resin (component (C)). By containing a thermoplastic resin, the adhesive composition can be easily formed into a film. Examples of thermoplastic resins include phenoxy resins, epoxy resins, polyester resins, polyamide resins, polyurethane resins, polyester urethane resins, acrylic rubbers, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types. If the epoxy equivalent of the epoxy resin is 400 g/eq or more, it shall be treated as a thermoplastic resin.

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 is measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve.

The content of the thermoplastic resin 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 content of the thermoplastic resin 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.

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 component (A). 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 component (A).

The adhesive composition may contain conductive particles. The conductive particles are not particularly limited as long as they are conductive particles. Metal particles composed of metals such as gold, silver, palladium, nickel, copper, and solder; conductive carbon particles composed of conductive carbon. coated conductive particles comprising a core containing non-conductive glass, ceramic, plastic (polystyrene, etc.), etc., and a coating layer containing the metal or conductive carbon described above and covering the core; The conductive particles are easily deformed by heating and/or pressurization, and when the electrodes are electrically connected to each other, the contact area between the electrodes and the conductive particles is increased to improve the conductivity between the electrodes. It may be coated conductive particles from the viewpoint of further improvement.

The average particle size of the 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 size of the 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 size of the 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.

The average particle size of the conductive particles is obtained by observing 300 conductive particles contained in the adhesive composition using a scanning electron microscope (SEM), measuring the particle size of each conductive particle, and determining the average particle size of 300 conductive particles. It is the average value of particle diameters. When the conductive particles are not spherical, the particle diameter of the conductive particles is the diameter of a circle circumscribing the conductive particles in the observation image using the SEM.

The particle density of the conductive particles in the adhesive composition may be 100/mm ² or more, 1000/mm ² or more, or 3000/mm ² or more from the viewpoint of obtaining stable connection resistance. The particle density of the conductive particles in the adhesive composition may be 100000/ ^mm2 or less, 50000/ ^mm2 or less, or 30000/mm2 ^or less from the viewpoint of ensuring insulation between adjacent electrodes. . From these points of view, the particle density of the conductive particles in the adhesive composition may be from 100 to 100,000/mm ² , from 1,000 to 50,000/mm ² , or from 3,000 to 30,000/mm ² .

The content of the 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 the conductive particles may be 50 wt% or less, 40 wt% or less, or 35 wt% or less based on the total weight of the adhesive composition.

The content of the conductive particles may be 10 parts by mass or more, 30 parts by mass or more, 50 parts by mass or more, or 70 parts by mass or more based on 100 parts by mass of component (A). The content of the 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 component (A).

The adhesive composition may further contain a coupling agent. The adhesive composition can further improve adhesiveness by containing 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-isocyanatopropyltriethoxysilane, and , and condensates thereof. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The content of the coupling agent 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 content of the coupling agent may be 15 wt% or less, 10 wt% or less, or 5 wt% or less based on the total weight of the adhesive composition.

The content of the coupling agent may be 1 part by mass or more, 3 parts by mass or more, or 5 parts by mass or more based on 100 parts by mass of component (A). 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 8 parts by mass or less based on 100 parts by mass of component (A).

The adhesive composition may further contain a filler. The adhesive composition can further improve connection reliability by containing a filler. Fillers include non-conductive fillers (eg, non-conductive particles). The filler may be either an inorganic filler or an organic filler.

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 by 1 type, and may be used in combination of 2 or more types.

Examples of organic fillers include silicone particles, methacrylate/butadiene/styrene particles, acrylic/silicone particles, polyamide particles, and polyimide particles. These may be used individually by 1 type, and may be used in combination of 2 or more types.

The filler may be an inorganic filler or silica particles from the viewpoint of improving the film formability and the reliability of the connected structure. The silica particles may be crystalline silica particles or amorphous silica particles, and these silica particles may be synthetic. A method for synthesizing silica may be a dry method or a wet method. The silica particles may contain at least one selected from the group consisting of fumed silica particles and sol-gel silica particles.

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

Alkoxysilane compounds include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, dimethoxydiphenylsilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, 3,3,3-trifluoropropyltrimethoxy Silane etc. are mentioned.

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, 1,3-divinyl-1,1,3,3-tetramethyldisilazane and the like.

Examples of siloxane compounds include tetradecamethylcycloheptasiloxane, decamethylcyclopentasiloxane, hexaphenylcyclosiloxane, octadecamethylcyclononasiloxane, hexadecamethylcyclooctasiloxane, dodecamethylcyclohexasiloxane, octaphenylcyclotetrasiloxane, hexa methylcyclotrisiloxane, heptaphenyldisiloxane, tetradecamethylhexasiloxane, dodecamethylpentasiloxane, hexamethyldisiloxane, 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-glycidyloxypropyl)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-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, octaphenyloctasilasilsesquioxane and the like.

Silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane. Silane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl )-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl- 3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane , 3-trimethoxysilylpropyl succinic anhydride and the like.

Silica particles surface-treated with a silane compound or a silane coupling agent are treated with 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, trimethoxyphenyl in order to further hydrophobize the hydroxyl group residues on the silica particle surface. The surface may be treated with a silane compound such as silane to make it more hydrophobic.

When the adhesive composition is used as an adhesive film for circuit connection, the surface-treated silica particles have a viewpoint that the fluidity is easily controlled when the adhesive film for circuit connection is pressure-bonded, and the connection structure after pressure-bonding. From the viewpoint of improving the mechanical properties and water resistance of the body, the reaction product (hydrolysis product) of silica and trimethoxyoctylsilane, the reaction product of silica and dimethylsiloxane, silicon dioxide or silica and dichloro (dimethyl ) a reaction product with silane, a reaction product (hydrolysis product) between silica and bis(trimethylsilyl)amine, and a reaction product between silica and hexamethyldisilazane. At least one selected from the group consisting of a reaction product of silica and trimethoxyoctylsilane and a reaction product of silica and bis(trimethylsilyl)amine may be included.

The content of the filler 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. The filler content may be 50 wt% or less, 40 wt% or less, or 35 wt% or less based on the total weight of the adhesive composition.

The content of the filler may be 1 part by mass or more, 5 parts by mass or more, or 10 parts by mass or more based on 100 parts by mass of component (A). The content of the filler may be 200 parts by mass or less, 150 parts by mass or less, or 100 parts by mass or less based on 100 parts by mass of component (A).

The adhesive composition may further contain components other than the above components. Other ingredients may include stabilizers, colorants, antioxidants, and the like. The adhesive composition may further contain a radical polymerizable compound and a radical polymerization initiator.

Examples of radically polymerizable compounds include acrylic compounds. Examples of acrylic compounds include (meth)acrylic acid compounds, (meth)acrylate compounds, and imide compounds thereof. These may be used in the form of monomers or oligomers, or may be used in combination of monomers and oligomers. A radically polymerizable compound may be used alone or in combination of two or more.

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; 2-hydroxy-1,3-diacryloxypropane, 2,2-bis[4-(acryloxymethoxy)phenyl]propane, 2,2-bis[4-(acryloxypoly aryloxy-hydroxyalkyl (meth)acrylate compounds such as ethoxy)phenyl]propane; dicyclopentenyl acrylate, tricyclodecanyl acrylate, and tris(acryloyloxyethyl) isocyanurate;

The radical polymerization initiator may generate free radicals by light or heat. Examples of radical polymerization initiators include organic peroxides and azo compounds. Organic peroxides include peroxyesters, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, peroxyketals, hydroperoxides, and silyl peroxides. A radical polymerization initiator may be used alone or in combination of two or more.

Peroxy esters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2- ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, L-hexylperoxy-2-ethylhexanoate, L-butylperoxy-2-ethylhexanoate t-Butylperoxyisobutyrate, 1,1-bis(t-butylperoxy)cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate , t-butyl peroxylaurate, 2,5-dimethyl-2,5-di(m-toluoylperoxy)hexane, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate , t-hexyl peroxybenzoate, and t-butyl peroxyacetate.

Dialkyl peroxides include α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butyl cumyl peroxide and the like. Examples of hydroperoxides include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

Diacyl peroxides include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, and benzoyl peroxide. peroxytoluene, benzoyl peroxide, and the like.

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

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, 2,2-bis(t-butylperoxy)decane and the like.

Specific examples of silyl peroxide include t-butyltrimethylsilyl peroxide, bis(t-butyl)dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis(t-butyl)divinylsilyl peroxide, tris(t -butyl)vinylsilyl peroxide, t-butyltriallylsilyl peroxide, bis(t-butyl)diallylsilyl peroxide, tris(t-butyl)allylsilyl peroxide, and the like.

<Adhesive film for circuit connection>
The circuit-connecting adhesive film of this embodiment has a region formed from the above-described adhesive composition of this embodiment. The regions may be films or layers. That is, another embodiment of the present disclosure is an adhesive film for circuit connection containing component (A) and component (B). The circuit-connecting adhesive film may contain conductive particles.

When the adhesive composition of the present embodiment contains conductive particles, the particle density of the conductive particles in the adhesive film for circuit connection is 100 particles/mm2 or ^more , 1000 particles/mm, from the viewpoint of obtaining stable connection resistance. It may be ² or more, or 3000/mm ² or more. The particle density of the conductive particles in the adhesive film for circuit connection is 100,000 particles/mm ² or less, 50,000 particles/mm ² or less, or 30,000 particles/mm ^{2 or} less from the viewpoint of ensuring insulation between adjacent electrodes. you can From these viewpoints, the particle density of the conductive particles in the adhesive film for circuit connection may be 100 to 100000/mm ² , 1000 to 50000/mm ² or 3000 to 30000/mm ² .

The content of the 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 circuit connection adhesive film. The content of the conductive particles may be 50% by mass or less, 40% by mass or less, or 35% by mass or less based on the total mass of the circuit-connecting adhesive film.

From the viewpoint of ensuring the curability of the circuit-connecting adhesive film, the content of the component (A) in the circuit-connecting adhesive film is 10% by mass or more and 20% by mass, based on the total mass of the circuit-connecting adhesive film. % by mass or more, 25% by mass or more, or 30% by mass or more. From the viewpoint of ensuring the formability of the circuit-connecting adhesive film, the content of component (A) in the circuit-connecting adhesive film is 60% by mass or less, 50% by mass or less, based on the total mass of the circuit-connecting adhesive film. % by mass or less, 45% by mass or less, or 40% by mass or less. From these viewpoints, the content of component (A) in the circuit-connecting adhesive film may be 10 to 60% by mass based on the total mass of the circuit-connecting adhesive film.

From the viewpoint of sufficiently accelerating the curing reaction, the content of the component (B) in the adhesive film for circuit connection is 1% by mass or more, 2% by mass or more, 3% by mass or more, based on the total mass of the adhesive film for circuit connection. % by mass or more, 4% by mass or more, or 5% by mass or more. From the viewpoint of improving the physical properties of the cured product, the content of the component (B) in the circuit-connecting adhesive film is 20% by mass or less, 15% by mass or less, 10% by mass or less, based on the total mass of the circuit-connecting adhesive film. % by mass or less, 8% by mass or less, or 6% by mass or less. From these viewpoints, the content of the component (B) in the circuit-connecting adhesive film may be 1 to 20% by mass based on the total mass of the circuit-connecting adhesive film.

From the viewpoint of sufficiently accelerating the curing reaction, the content of the component (B) in the circuit-connecting adhesive film is 1% by mass or more and 3% by mass, based on the total mass of the circuit-connecting adhesive film excluding the conductive particles. % or more, 5 mass % or more, or 7 mass % or more. From the viewpoint of improving the physical properties of the cured product, the content of the component (B) in the circuit-connecting adhesive film is 30% by mass or less and 25% by mass, based on the total mass of the circuit-connecting adhesive film excluding the conductive particles. % or less, 20 mass % or less, 15 mass % or less, or 10 mass % or less. From these viewpoints, the content of the component (B) in the circuit-connecting adhesive film may be 1 to 30% by mass based on the total mass of the circuit-connecting adhesive film excluding the conductive particles.

The content of the component (B) in the circuit-connecting adhesive film is 1% by mass or more, based on the total mass of the circuit-connecting adhesive film excluding conductive particles and fillers, from the viewpoint of sufficiently promoting the curing reaction. , 3% by mass or more, 5% by mass or more, or 7% by mass or more. The content of the component (B) in the circuit-connecting adhesive film is 30% by mass or less, based on the total mass of the circuit-connecting adhesive film excluding conductive particles and fillers, from the viewpoint of improving the physical properties of the cured product. , 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less. From these viewpoints, the content of the component (B) in the circuit-connecting adhesive film may be 1 to 30% by mass based on the total mass of the circuit-connecting adhesive film excluding the conductive particles and the filler. good.

The content of the thermoplastic resin in the circuit-connecting 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-connecting adhesive film. The content of the thermoplastic resin in the circuit-connecting 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-connecting adhesive film.

The content of the coupling agent in the circuit-connecting adhesive film is 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-connecting adhesive film. good too. The content of the coupling agent in the circuit-connecting adhesive film may be 10% by mass or less, 5% by mass or less, or 3% by mass or less based on the total mass of the circuit-connecting adhesive film.

The content of the filler in the circuit-connecting 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-connecting adhesive film. The content of the filler in the circuit-connecting adhesive film may be 50% by mass or less, 40% by mass or less, or 35% by mass or less based on the total mass of the circuit-connecting adhesive film.

The content of each component in the adhesive film for circuit connection based on 100 parts by mass of component (A) is the same as the content of each component based on 100 parts by mass of component (A) in the above adhesive composition. may be within the range.

The circuit-connecting adhesive film may be a single layer or may have a multi-layer structure in which multiple layers are laminated. When the circuit-connecting adhesive film has a multilayer structure, the circuit-connecting adhesive film includes, for example, a first adhesive layer containing component (A) and component (B), and a first adhesive layer. A second adhesive layer other than the adhesive layer may be provided. That is, the circuit-connecting adhesive film 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 component (A), component (B), and conductive particles. When the circuit-connecting adhesive film 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.

The circuit-connecting adhesive film may have multiple regions with different component types and contents. The circuit-connecting adhesive film may comprise, for example, a first region and a second region disposed on the first region, the first region comprising components (A) and (B ) component and the region containing the . That is, the adhesive film for circuit connection includes a first region which is a region formed from a first adhesive composition containing the component (A) and the component (B), and the first region and a second region, which is a region formed from a second adhesive composition disposed thereon. When the circuit-connecting adhesive film has a plurality of regions, the content of each of the above components in each region may be within the above content range based on the total mass of each region.

The circuit connection adhesive film may be provided on a substrate (for example, PET film) or the like. The substrate-attached adhesive film for circuit connection is produced, 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. can do.

FIG. 1 is a schematic cross-sectional view showing a circuit-connecting adhesive film according to one embodiment. As shown in FIG. 1, the circuit-connecting adhesive film 1 is, in one embodiment, 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 the components (A) and (B) described above. The circuit-connecting adhesive film 1 may be in an uncured state or in a partially cured state.

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

In one embodiment, the circuit connecting adhesive film comprises a first region comprising a first adhesive component and a second region comprising a second adhesive component adjacent to the first region. and one or both of the first region and the second region may be formed of the adhesive composition of the present embodiment described above. Each of the first region and the second region may be a layer.

In one embodiment, the circuit-connecting adhesive film may have a multilayer structure having two or more layers, for example, as shown in FIG. (First adhesive layer consisting of adhesive component 2A and conductive particles 3A dispersed in adhesive component 2A) 1A and layer not containing conductive particles (second adhesive layer consisting of adhesive component 2B layer) 1B. In this case, the first adhesive layer 1A is a layer made of an adhesive composition (first adhesive composition) containing at least the above-described components (A) and (B), and conductive particles. It can be. The second adhesive layer 1B may be a layer made of an adhesive composition (second adhesive composition) containing at least the components (A) and (B) described above. The kind, content, etc. of each component contained in the second adhesive layer 1B may be the same as or different from those in the first adhesive layer 1A. The first adhesive layer 1A and the second adhesive layer 1B of the circuit-connecting adhesive film 1 may each be in an uncured state or in a partially cured state.

The thickness of the first adhesive layer 1A may be, for example, 1 µm or more or 3 µm or more, and may be 15 µm or less or 10 µm or less. The thickness of the second adhesive layer 1B may be, for example, 1 μm or more or 3 μm or more, and may be 20 μm or less or 15 μm or less. The thickness of the first adhesive layer 1A may be the same as or different from the thickness of the second adhesive layer 1B. 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) is 0.1. or more, or 0.3 or more, and may be 1.5 or less, or 0.5 or less.

The circuit connection adhesive film may be an anisotropic conductive adhesive film (anisotropic conductive film) or a conductive adhesive film without anisotropic conductivity.

<Connection structure>
Another embodiment of the present disclosure includes a first circuit member having a first electrode, a second circuit member having a second electrode, and disposed between the first circuit member and the second circuit member. and a connecting portion for electrically connecting the first electrode and the second electrode to each other, wherein the connecting portion contains the cured adhesive film for circuit connection.

FIG. 3 is a schematic cross-sectional view showing one embodiment of the connection structure. As shown in FIG. 3 , the structure 10 includes a first circuit member 4 and a second circuit member 5 facing each other, and a first circuit member 4 and a first circuit member 5 between the first circuit member 4 and the second circuit member 5 . A connecting portion 6 that connects the circuit member 4 and the second circuit member 5 is provided.

The first circuit member 4 includes a first circuit board 41 and a first electrode 42 formed on the main surface 41 a of the first circuit board 41 . The second circuit member 5 includes a second circuit board 51 and second electrodes 52 formed on the main surface 51 a of the second circuit board 51 .

The first circuit member 4 and the second circuit member 5 are not particularly limited as long as they are formed with electrodes that require electrical connection. Examples of members (circuit members, etc.) on which electrodes are formed include inorganic substrates such as semiconductors, glass, and ceramics; polyimide substrates such as TCP, FPC, and COF; electrodes on films such as polycarbonate, polyester, and polyethersulfone; A printed wiring board or the like is used, and a plurality of these may be used in combination.

The connection part 6 contains the cured product of the adhesive film 1 for circuit connection, and contains the insulating substance 7 which is the cured product of the adhesive component 2 and the conductive particles 3 . The conductive particles 3 are placed not only between the opposing first electrode 42 and the 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. may be placed. 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 .

In the structure 10, the first electrode 42 and the second electrode 52 facing each other are electrically connected via the conductive particles 3, as described above. Therefore, the connection resistance between the first electrode 42 and the second electrode 52 is sufficiently reduced. Therefore, the current flow between the first electrode 42 and the second electrode 52 can be made smooth, and the functions of the first circuit member 4 and the second circuit member 5 can be fully exhibited. can be done.

<Method for manufacturing connection structure>
Another embodiment of the present disclosure is to interpose the circuit connection adhesive film between a first circuit member having a first electrode and a second circuit member having a second electrode, A method of manufacturing a connection structure, comprising the step of thermally compressing a first circuit member and a second circuit member to electrically connect the first electrode and the second electrode to each other.

FIG. 4 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a connection structure. As shown in FIG. 4(a), first, a first circuit member 4 and a circuit-connecting adhesive film 1 are prepared. Next, the circuit-connecting adhesive film 1 is placed on the main surface 41 a of the first circuit member 4 . When the circuit-connecting adhesive film 1 is laminated on a substrate (not shown), the circuit-connecting adhesive film 1 side of the substrate is directed toward the first circuit member 4, A laminate is placed on the first circuit member 4 . When the adhesive film 1 for circuit connection has a first adhesive layer 1A and a second adhesive layer 1B as shown in FIG. Therefore, it is preferable to arrange the adhesive layer (first adhesive layer 1A) containing the conductive particles so as to be in contact with the main surface 41a of the first circuit member 4 .

Then, the circuit-connecting adhesive film 1 is pressurized in the directions of arrows A and B in FIG. 4(a) to temporarily connect the circuit-connecting adhesive film 1 to the first circuit member 4 (FIG. reference). At this time, heating may be performed together with the pressurization.

Subsequently, as shown in FIG. 4( c ), on the circuit-connecting adhesive film 1 placed on the first circuit member 4 , the second electrode 52 side is directed toward the first circuit member 4 . (that is, in a state in which the first electrode 42 and the second electrode 52 are arranged to face each other, and the circuit connection adhesive is placed between the first circuit member 4 and the second circuit member 5 A second circuit member 5 is further arranged (with the film 1 interposed). When the circuit-connecting adhesive film 1 is laminated on a substrate (not shown), the substrate is peeled off and then the second circuit member 5 is arranged on the circuit-connecting adhesive film 1. .

Then, the circuit-connecting adhesive film 1 is thermocompression bonded in the directions of arrows A and B in FIG. 4(c). As a result, the circuit-connecting adhesive film 1 is cured, and final connection is established to electrically connect the first electrode 42 and the second electrode 52 to each other. As a result, a structure 10 as shown in FIG. 3 is obtained.

In the structure 10 obtained as described above, it is possible to bring the conductive particles 3 into contact with both the first electrode 42 and the second electrode 52 facing each other. The connection resistance between the electrodes 52 can be sufficiently reduced.

By applying pressure while heating the adhesive film 1 for circuit connection, the adhesive component 2 is cured to become the insulating material 7 while the distance between the first electrode 42 and the second electrode 52 is sufficiently reduced. , the first circuit member 4 and the second circuit member 5 are firmly connected via the connecting portion 6 . In addition, in the structure 10, a sufficiently high adhesive strength is maintained for a long period of time. Therefore, in the structure 10, the change over time of the distance between the first electrode 42 and the second electrode 52 is sufficiently suppressed, and the long-term reliability of the electrical characteristics between the first electrode 42 and the second electrode 52 is maintained. is superior.

The present disclosure will be specifically described below with reference to examples. However, the present disclosure is not limited only to the following examples.

<Synthesis of pyridinium salt (curing agent B1)>
100 mL of acetonitrile and a stirrer tip were placed in a 300 mL Erlenmeyer flask and placed on a magnetic stirrer. 2-cyanopyridine 12.5 g (120 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), 2,4,6-trimethylbenzyl chloride 16.8 g (100 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), and sodium iodide 17.8 g (119 mmol , manufactured by Tokyo Chemical Industry Co., Ltd.) was added to acetonitrile in a 300 mL Erlenmeyer flask and allowed to react at room temperature (25° C.) for 24 hours to obtain crystals. The obtained crystals were filtered through a glass filter, and the crystals on the glass filter were washed with acetone and distilled water, and dried in a vacuum to obtain 29.1 g of 2-cyano-1-(2,4,6-trimethylbenzyl). ) gave pyridinium iodide (80% yield).

200 mL of dichloromethane and a stirrer tip were placed in a 500 mL Erlenmeyer flask and placed on a magnetic stirrer. 3.6 g (10 mmol) of the resulting 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium iodide was added to a 500 mL Erlenmeyer flask and suspended in dichloromethane in the 500 mL Erlenmeyer flask. 72 g (10.2 mmol, manufactured by Nippon Shokubai Co., Ltd.) of sodium tetrakis(pentafluorophenyl)borate aqueous solution (10% solid content) and 50 mL of distilled water are added to a 500 mL Erlenmeyer flask and stirred at room temperature (25° C.) for 3 hours. performed a salt exchange reaction. After stirring, the organic layer was washed with distilled water, concentrated, and dried under vacuum to obtain 8.0 g of the compound (88% yield). The resulting compound was used as curing agent B1.

The obtained compound was measured by nuclear magnetic resonance spectroscopy (1H-NMR, manufactured by JEOL Ltd., JNM-ECX400II), and the following spectral data were obtained. Measurement by ¹ H-NMR confirmed that the obtained compound was 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium tetrakis(pentafluorophenyl)borate having the following structure.
¹ H-NMR (400 MHz, CD ₃ OD), δ: 2.26 (s, 6H), 2.32 (s, 3H), 6.10 (s, 2H), 7.08 (s, 2H), 8.25 (td, 1H, J = 3.2, 6.4Hz) 8.43 (d, 1H, J = 6.4Hz) 8.77-8.82 (m, 2H)

<Synthesis of pyridinium salt (curing agent B3)>
100 mL of acetonitrile and a stirrer tip were placed in a 300 mL Erlenmeyer flask and placed on a magnetic stirrer. 2-cyanopyridine 12.5 g (120 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), 2,4,6-trimethylbenzyl chloride 16.8 g (100 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), and sodium iodide 17.8 g (119 mmol , manufactured by Tokyo Chemical Industry Co., Ltd.) was added to acetonitrile in a 300 mL Erlenmeyer flask and allowed to react at room temperature (25° C.) for 24 hours to obtain crystals. The obtained crystals were filtered through a glass filter, and the crystals on the glass filter were washed with acetone and distilled water, and dried in a vacuum to obtain 29.1 g of 2-cyano-1-(2,4,6-trimethylbenzyl). ) gave pyridinium iodide (80% yield).
200 mL of dichloromethane and a stirrer tip were placed in a 500 mL Erlenmeyer flask and placed on a magnetic stirrer. 3.6 g (10 mmol) of the resulting 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium iodide was added to a 500 mL Erlenmeyer flask and suspended in dichloromethane in the 500 mL Erlenmeyer flask. Tetrakis [3,5-bis (trifluoromethyl) phenyl] sodium borate hydrate 9.2 g (10.2 mmol, manufactured by Tokyo Kasei Kogyo Co., Ltd.) and distilled water 100 m were added to a 500 mL Erlenmeyer flask, room temperature (25 ° C. ) for 3 hours to carry out a salt exchange reaction. After stirring, the organic layer was washed with distilled water, concentrated and dried under vacuum to obtain 8.2 g of the compound (yield 75%). The resulting compound was used as curing agent B3.

The obtained compound was measured by nuclear magnetic resonance spectroscopy ( ¹ H-NMR, manufactured by JEOL Ltd., JNM-ECX400II), and the following spectral data were obtained. 2-cyano-1-(2,4,6-trimethylbenzyl)pyridinium tetrakis[3,5-bis(trifluoromethyl)phenyl] having the following structure from the measurement by ¹ H-NMR. Confirmed to be borate.
¹ H-NMR (400 MHz, (CD ₃ ) ₂ O), δ: 2.34 (s, 9H), 6.31 (s, 2H), 7.14 (s, 2H), 7.68 (s, 4H), 7.80 (s, 8H), 8.57 (t, 1H, J = 6.4Hz), 8.71 (d, 1H, J = 6.4Hz) 9.03-9.08 (m , 2H)

<Synthesis of phenoxy resin a>
4,4′-(9-Fluorenylidene)-diphenol in a 3000 mL 3-necked flask equipped with a Dimroth condenser, a calcium chloride tube, and a Teflon stir bar connected to a stirring motor. 45 g (manufactured by Sigma-Aldrich Japan Co., Ltd.) and 50 g of 3,3',5,5'-tetramethylbiphenol diglycidyl ether (trade name: YX-4000H, manufactured by Mitsubishi Chemical Corporation) were dissolved in 1000 mL of N-methylpyrrolidone. was used as the reaction solution. 21 g of potassium carbonate was added to this reaction liquid, and the mixture was stirred for 3 hours while being heated to 110° C. with a mantle heater. The reaction solution after stirring was dropped into a beaker containing 1000 mL of methanol, and suction filtration was performed to collect the generated precipitate by filtration. The filtered precipitate was further washed with 300 mL of methanol three times to obtain 75 g of phenoxy resin a. The molecular weight of the obtained phenoxy resin a was measured by a high-performance liquid chromatograph (manufactured by Tosoh Corporation, GP8020, columns: Gelpack GL-A150S and GLA160S manufactured by Hitachi Chemical Co., Ltd., eluent: tetrahydrofuran, flow rate: 1.0 mL/min). Mn = 15769, Mw = 38045 and Mw/Mn = 2.413 in terms of polystyrene.

<Production of conductive particles>
A layer of nickel was formed on the surface of the crosslinked polystyrene particles so that the layer thickness was 0.15 μm. Thus, conductive particles having an average particle size of 3.3 μm, a maximum particle size of 3.5 μm, and a specific gravity of 2.7 were obtained.

<Preparation of adhesive film for circuit connection>
The first adhesive composition that forms the first adhesive layer by mixing each component in the blending amount (unit: parts by mass) shown in Table 1, and the second adhesive that forms the second adhesive layer A formulation composition was prepared. The details of each component in Table 1 are as follows, and the blending amount of each component in the table represents the blending amount of the non-volatile matter.
・ Epoxy resin A2: Tetrafunctional naphthalene skeleton epoxy resin (trade name: HP4700, manufactured by DIC Corporation)
A6: Bifunctional bisphenol F type epoxy resin (trade name: YL983U, manufactured by Mitsubishi Chemical Corporation)
A7: Polyfunctional trisphenolmethane type epoxy resin (trade name: jER1032H60, manufactured by Mitsubishi Chemical Corporation)
Curing agent B1: Pyridinium salt synthesized above B3: Pyridinium salt synthesized above Thermoplastic resin C1: Phenoxy resin a synthesized above
C3: Epoxy resin (trade name: jER1010, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 3000 to 5000 g/eq)
Filler D1: surface-treated silica particles (hydrolysis product of silica and bis(trimethylsilyl)amine)
D2: Surface-treated silica fine particles (hydrolysis product of trimethoxyoctylsilane and silica, trade name: Aerosil R805, manufactured by Evonik Industries AG, diluted with an organic solvent to a non-volatile content of 10% by mass) use)
D3: Silica particles (manufactured by Admatechs Co., Ltd., trade name: Admafine SE2050)
Coupling agent E1: 3-glycidoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)
Conductive particles F1: Conductive particles prepared above Stabilizer G: 4-hydroxyphenyldimethylsulfonium sulfate (manufactured by Tokyo Chemical Industry Co., Ltd.)

A second adhesive composition was applied onto the substrate (PET film) to form a second adhesive layer on the substrate. Furthermore, the first adhesive composition is applied on the second adhesive layer to form the first adhesive layer, the first adhesive layer, the second adhesive layer, the substrate were laminated in this order to prepare an adhesive film for circuit connection. The thickness of the first adhesive layer of each circuit-connecting adhesive film of Examples 1 and 2 was 7 μm, and the thickness of the second adhesive layer was 7 μm.

<Production of connection structure>
AlNd (100 nm)/Mo (50 nm)/AlNd (100 nm)/Mo (50 nm)/ An ITO (100 nm) wiring pattern (pattern width: 19 μm, inter-electrode space: 5 μm) was prepared. As a second circuit member, an IC chip in which bump electrodes are arranged in two rows in a zigzag pattern (outer shape: 0.9 mm × 20.3 mm, thickness: 0.3 mm, size of bump electrode: 70 µm × 12 µm, bump electrode space: 12 μm, bump electrode thickness: 8 μm).

Using the adhesive films for circuit connection of Examples 1 and 2, connection structures were produced. First, the first adhesive layer of the circuit connecting adhesive film was placed on the first circuit member. Using a thermocompression bonding device (LD-06, manufactured by Ohashi Seisakusho Co., Ltd.) consisting of a ceramic heater stage and a tool (8 mm × 50 mm), under the conditions of 50 ° C. and 0.98 MPa (10 kgf / cm ² ). Heat and pressure were applied for 2 seconds to attach the circuit connecting adhesive film to the first circuit member. Next, the base material on the opposite side of the circuit-connecting adhesive film to the first circuit member was peeled off, and the bump electrodes of the first circuit member and the circuit electrodes of the second circuit member were aligned. Then, using a heat tool (8 mm × 45 mm), a PTFE sheet with a thickness of 50 µm is used as a cushioning material on a pedestal heated to 90 ° C. and heated at 115 ° C. for 5 seconds at 40 MPa. , the second adhesive layer of the circuit-connecting adhesive film was adhered to the second circuit member to prepare a connection structure. The mounting temperature was the measured maximum temperature of the adhesive film for circuit connection, and the pressure was a value calculated with respect to the total area of the surfaces of the bump electrodes of the second circuit member facing the first circuit member. .

<Evaluation of connection resistance>
Immediately after mounting and after the high temperature and high humidity test (after the HAST test), the connection resistance was measured at 14 locations by the four-terminal measurement method, and the average value of the connection resistance values was evaluated. The HAST test was performed by placing the connection structure in an accelerated life tester (manufactured by HIRAYAMA, trade name "PC-242HSR2", conditions: 110°C/85% RH/150 hours). The connection resistance was evaluated as A when the connection resistance was less than 10 Ω, B when 10 Ω or more and less than 20 Ω, C when 20 Ω or more and less than 25 Ω, D when 25 Ω or more and less than 30 Ω, and E when 30 Ω or more. Table 2 shows the evaluation results.

<DSC measurement>
For each circuit connection adhesive film of Examples 1 and 2, using a differential scanning calorimeter (trade name: DSC Q1000) manufactured by TA Instruments Japan Co., Ltd., under a nitrogen atmosphere, the temperature was increased at a rate of 10 ° C./ Differential scanning calorimetry (DSC) was performed under the conditions of minutes and a measurement temperature range of 50 to 300°C. DSC measurement was performed on the sample immediately after collection and the sample after storage at 40°C for 15 hours. FIG. 5 shows the DSC measurement results of the sample immediately after collection in Example 1, FIG. 6 shows the DSC measurement result of the sample in Example 1 after storage at 40° C. for 15 hours, FIG. 7 shows the DSC measurement results, and FIG. 8 shows the DSC measurement results of the sample of Example 2 after storage at 40° C. for 15 hours. In FIGS. 5-8, the dashed lines show the measured results of heat flow, and the solid lines show the measured results of derivative heat flow.

As shown in Table 2, the pyridinium cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position, the benzyl group has an electron-donating group, and the anion is B(C ₆ F ₅ ) ₄ ⁻ or B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (wherein the CF ₃ groups are substituted at the 3,5-positions of the phenyl group), an adhesive composition containing a pyridinium salt It was confirmed that the article can be cured at low temperature (115° C.) and achieve excellent connection resistance. Furthermore, when the anion of the pyridinium salt is B(C ₆ H ₃ (CF ₃ ) ₂ ) ₄ ⁻ (wherein the CF ₃ groups are substituted at the 3,5-positions of the phenyl group), excellent It has been confirmed that the connection resistance can be realized.

DESCRIPTION OF SYMBOLS 1... Adhesive film for circuit connection 1A... First adhesive layer 1B... Second

adhesive layer

2, 2A, 2B...

Adhesive component

3, 3A... Conductive particles 4... First circuit Member 5 Second circuit member 6 Connecting part 7 Insulating substance 10 Structure 41 First circuit board 42 First electrode 51 Second circuit board 52 … the second electrode.

Claims

(A) an epoxy resin and (B) a curing agent,
As the component (B), a pyridinium salt is included,
The pyridinium salt comprises a pyridinium cation and an anion,
the pyridinium cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position;
the benzyl group has an electron donating group,
the anion is B(C 6 F 5 ) 4 − or B(C 6 H 3 (CF 3 ) 2 ) 4 − (provided that CF 3 groups are substituted at the 3,5-positions of the phenyl group); adhesive composition.
The adhesive composition according to claim 1, further containing conductive particles.
An adhesive film for circuit connection, having a region formed by the adhesive composition according to claim 1 or 2.
a first region containing a first adhesive component and a second region adjacent to the first region containing a second adhesive component;
An adhesive film for circuit connection, wherein one or both of the first region and the second region are formed from the adhesive composition according to claim 1 or 2.
a first circuit member having a first electrode;
a second circuit member having a second electrode;
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;
with
A connection structure, wherein the connection portion contains the cured adhesive film for circuit connection according to claim 3 .
The adhesive film for circuit connection according to claim 3 is interposed between a first circuit member having a first electrode and a second circuit member having a second electrode, and the first circuit A method of manufacturing a connected structure, comprising the step of thermally compressing the member and the second circuit member to electrically connect the first electrode and the second electrode to each other.
A pyridinium salt comprising a pyridinium cation and an anion,
the pyridinium cation has a benzyl group at the 1-position and an electron-withdrawing group at the 2-position;
the benzyl group has an electron donating group,
the anion is B(C 6 F 5 ) 4 − or B(C 6 H 3 (CF 3 ) 2 ) 4 − (provided that CF 3 groups are substituted at the 3,5-positions of the phenyl group); pyridinium salt.