JP2018170208A - Anisotropically conductive film, connection structure, and method for manufacturing connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anisotropically conductive film which enables both of low-temperature fast curing and storage with stability, and enables the achievement of satisfactory connection reliability and a good adhesive force.SOLUTION: An anisotropically conductive film is interposed between circuit electrodes opposed to each other, and used to press the circuit electrodes and thus, electrically connect between the electrodes in a pressurizing direction. The anisotropically conductive film comprises an adhesive layer including: a film-forming material (a); an epoxy or oxetane compound (b); a thiol compound (c); and a hardening agent (d) which produces a base by light. In the anisotropically conductive film, the hardening agent (d) which produces a base by light includes a carboxylate represented by the general formula (1) below. [In the general formula (1), R represents CHor H, X represents a base selected from amidines, guanidines, and phosphazene derivatives.]SELECTED DRAWING: None

Description

  The present invention relates to an anisotropic conductive film, a connection structure, and a method for manufacturing the connection structure.

  Conventionally, for example, for connection between a liquid crystal display and a tape carrier package (TCP), connection between a flexible printed circuit board (FPC) and TCP, or connection between an FPC and a printed wiring board, conductive particles are dispersed in an adhesive film. An anisotropic conductive film is used. In addition, when a semiconductor silicon chip is mounted on a substrate, so-called chip-on-glass (COG) in which the semiconductor silicon chip is directly mounted on the substrate is used instead of the conventional wire bonding. An adhesive film is used.

  In recent years, in the field of precision electronic equipment, the density of circuits has been increasing, and the electrode width and electrode interval have become extremely narrow. For this reason, the conventional connection conditions of circuit adhesives using epoxy resin systems have problems such as wiring dropping, peeling, and misalignment. COG is caused by the difference in thermal expansion between the chip and the substrate. There is a problem that warping occurs. Furthermore, there is a need to improve the throughput in order to reduce the cost, and an adhesive that can be cured at a low temperature (100 to 170 ° C.) and in a short time (within 10 seconds), in other words, an adhesive that can be cured at a low temperature is required. Has been.

  An epoxy resin polymerization system capable of rapid curing at low temperature includes cation curing of an epoxy resin. In this case, as the cationic polymerization initiator, for example, a polymerization initiator of a cationic polymerizable substance having a latent property mainly composed of a sulfonium salt is widely used (see Patent Document 1).

However, in the cationic polymerization initiator mainly composed of a sulfonium salt, SbF ₆ , AsF ₆ , PF ₆ , and BF ₄ are used as the counter anion. However, these cationic polymerization initiators each have a fluorine atom of the counter anion as boron. Since they are directly bonded to atoms, phosphorus atoms, and antimony atoms, they lose stability when exposed to high temperatures or high humidity, and fluorine ions are likely to be separated and generated. Therefore, the sulfonium salt complex has a problem in that a large amount of fluorine ions are generated when exposed to a high temperature and high humidity state during cationic polymerization and after mounting, and corrodes metal wiring, ITO wiring and connection pads.

  On the other hand, as an epoxy resin polymerization system having excellent corrosion resistance, adhesive strength and connection reliability, anionic curing of epoxy resins can be mentioned. In this case, dicyandiamide, an amine salt, a modified imidazole compound and the like have been proposed as an anionic polymerization initiator having a potential. In addition, studies have been made to impart latency to the curing agent by reacting the surface of the powdery amine compound with isocyanate to inactivate the surface of the amine compound (see Patent Document 2). Furthermore, a microcapsule type curing agent has also been proposed in which a powdered amine compound is encapsulated by reacting with an isocyanate in an epoxy resin to form a single component (see Patent Document 3).

  However, in the case of conventional anionic polymerization initiators, those having excellent storage stability have low curability, while curing requires high temperature or long time, while those having high curability have low storage stability, for example It needs to be stored at a low temperature such as -20 ° C.

  Further, studies have been made to cure the epoxy resin by generating a base by the action of light. In this case, if the light such as ultraviolet rays is not irradiated, the storage stability of the resin composition is excellent, and no corrosive substance is generated like the cationic polymerization initiator (see Patent Documents 4 and 5).

JP 2004-217551 A Japanese Patent Publication No.58-55970 JP-A-1-70523 JP 2005-264156 A JP 2009-280785 A

  However, it has been difficult to satisfy the corrosion resistance, the storage stability, and the low-temperature rapid curability at the same time by the conventionally provided methods. In particular, in the method of curing the epoxy resin by generating a base by the action of light, although the corrosion resistance and the storage stability are relatively good, the wavelength of ultraviolet rays for activating the curing agent is limited to a short wavelength. Good low temperature fast curability is obtained because of the fact that there is a limit to the strength of the base that can be generated, and the reaction that generates the base by the action of light is not performed rapidly. There was a problem that it was difficult.

  The present invention has been made in view of the above-described problems of the prior art, and can achieve both low temperature rapid curing and storage stability, and can provide good connection reliability and good adhesive strength. It aims at providing the manufacturing method of a film, a connection structure, and a connection structure.

  In view of the above problems, the present inventors conducted various studies, and as a result, an anisotropic conductive film containing a specific curing agent that generates a base by light together with an epoxy compound or an oxetane compound and a thiol compound, The present inventors have found that the problem can be solved and have completed the present invention.

［一般式（１）中、ＲはＣＨ_３又はＨを示し、Ｘはアミジン類、グアニジン類、又はホスファゼン誘導体から選ばれる塩基類を示す。］ That is, the present invention is an anisotropic conductive film that is interposed between opposing circuit electrodes and is used to pressurize the circuit electrodes and electrically connect the electrodes in the pressurizing direction, An adhesive layer containing a film-forming material, (b) an epoxy compound or oxetane compound, (c) a thiol compound, and (d) a curing agent that generates a base by light, and (d) by the light Provided is an anisotropic conductive film in which a curing agent that generates a base contains a carboxylate represented by the following general formula (1).

[In General Formula (1), R represents CH ₃ or H, and X represents a base selected from amidines, guanidines, or phosphazene derivatives. ]

  Since the anisotropic conductive film of the present invention has the above-described configuration, it has both low-temperature short-time curability (low-temperature fast-curability) and storage stability, and has anisotropic conductivity with excellent connection reliability and adhesive strength. Realization of a film becomes possible.

The amidines are compounds represented by the following formula (2), the guanidines are compounds represented by the following formula (3-1) or the formula (3-2), and the phosphazene derivatives. Is preferably a compound represented by the following formula (4-1), formula (4-2), formula (4-3), or formula (4-4). When these compounds are used, since the base generated by ultraviolet irradiation has high basicity, low temperature fast curability can be expected, and the cured product of the anisotropic conductive film has high adhesive strength. A connection structure in which circuit members are more firmly bonded can be obtained.

  The (c) thiol compound is preferably a polythiol compound having three or more thiol groups. When the polythiol compound is used, a three-dimensional crosslinked structure can be formed, and the physical properties of the anisotropically conductive film after curing can be improved and a reduction in resistance can be expected.

  Moreover, content of the hardening | curing agent which generate | occur | produces a base by the said (d) light in the said adhesive bond layer is 0.5 with respect to a total of 100 mass parts of (b) epoxy compound or oxetane compound, and (c) thiol compound. It is preferably ~ 30 parts by mass. (D) By containing a curing agent that generates a base by light within the above range, (b) both rapid curing properties of the epoxy compound or oxetane compound and thiol compound and cured properties of cured products of these compounds Is possible.

  In the anisotropic conductive film of the present invention, the adhesive layer contains conductive particles, and the total volume of the (a) film-forming material, the (b) epoxy compound or oxetane compound, and the (c) thiol compound is 100 volumes. It is preferable to contain 0.1-50 volume part with respect to a part. In this case, when the connection structure is produced using the anisotropic conductive film, it becomes easy to connect the circuit electrodes with a low connection resistance while preventing a short circuit of the circuit.

  The present invention also provides a first circuit member provided with bump electrodes and a second circuit provided with circuit electrodes corresponding to the bump electrodes, using the cured anisotropic conductive film of the present invention. Provided is a connection structure in which a member is bonded and the bump electrode and the circuit electrode are electrically connected.

  The present invention also provides a difference between the main surface of the first circuit member provided with the bump electrode and the main surface of the second circuit member provided with the circuit electrode corresponding to the bump electrode. An anisotropic conductive film is disposed, and the anisotropic conductive film is heated and pressurized via the first circuit member and the second circuit member, and further cured by irradiating ultraviolet rays from the back surface of the second circuit member. And connecting the first circuit member and the second circuit member via a cured product of the anisotropic conductive film, and electrically connecting the bump electrode and the circuit electrode. A method for manufacturing a body is provided.

  According to the manufacturing method of the connection structure, the anisotropic conductive film is heated and pressurized through the first circuit member and the second circuit member, and further, ultraviolet rays are irradiated from the back surface of the second circuit member. Therefore, the manufacturing time of the connection structure is equivalent to the case where only heating and pressurization are performed. Therefore, even if an ultraviolet irradiation step is added, it is possible to manufacture a connection structure without causing a decrease in throughput.

  The present invention further corresponds to the above circuit electrode after the anisotropic conductive film of the present invention is disposed on the second circuit member provided with the circuit electrode and irradiated with ultraviolet rays from the anisotropic conductive film. A first circuit member provided with a bump electrode is disposed on the anisotropic conductive film, and the anisotropic conductive film is heated and pressurized via the first circuit member and the second circuit member. Curing and bonding the first circuit member and the second circuit member via a cured product of the anisotropic conductive film, and electrically connecting the bump electrode and the circuit electrode A method for manufacturing a structure is provided.

  According to this method for manufacturing a connection structure, since ultraviolet rays are applied from above the anisotropic conductive film attached to the second circuit member, the first circuit member is placed and crimped. It is possible to uniformly irradiate ultraviolet rays even on a glass member or plastic member having a metal wiring circuit that shields, and even when a light-blocking circuit member such as polyimide is used, the adhesion surface between circuit members It becomes possible to irradiate ultraviolet rays.

  According to the present invention, there is provided an anisotropic conductive film, a connection structure, and a method for manufacturing the connection structure that can achieve both low-temperature rapid curing and storage stability and can obtain good connection reliability and good adhesion. Can be provided. By using the anisotropic conductive film of the present invention, connection reliability between facing circuit members can be ensured even when mounted at low temperature. Furthermore, the method for manufacturing a connection structure of the present invention can produce a connection structure satisfactorily even when a substrate having metal wiring and a substrate having light shielding properties are used.

It is a typical sectional view showing one embodiment of a connection structure concerning the present invention. It is a typical sectional view showing one embodiment of an anisotropic conductive film concerning the present invention. It is typical sectional drawing which shows other one Embodiment of the anisotropically conductive film which concerns on this invention. It is typical sectional drawing which shows the manufacturing process of the connection structure shown in FIG. FIG. 5 is a schematic cross-sectional view showing a step subsequent to FIG. 4.

  Hereinafter, preferred embodiments of an anisotropic conductive film and a connection structure according to the present invention and a method for manufacturing the connection structure will be described with reference to the drawings.

[Configuration of connection structure]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a connection structure according to the present invention. As shown in the figure, the connection structure 1 includes a first circuit member 2 and a second circuit member 3 that face each other, and a cured product 4 of an anisotropic conductive film that connects these circuit members 2 and 3. And is configured.

  The first circuit member 2 is, for example, a tape carrier package (TCP), a printed wiring board, a semiconductor silicon chip, or the like. The first circuit member 2 has a plurality of bump electrodes 6 on the mounting surface 5 a side of the main body 5. The bump electrode 6 has, for example, a rectangular shape in plan view, and has a thickness of, for example, 3 μm or more and less than 18 μm. For example, Au or the like is used as a material for forming the bump electrode 6, which is more easily deformed than the conductive particles P contained in the cured product 4 of the anisotropic conductive film. Note that an insulating layer may be formed on a portion of the mounting surface 5a where the bump electrode 6 is not formed.

  The second circuit member 3 is, for example, a glass substrate or a plastic substrate, a flexible printed circuit board (FPC), a ceramic wiring board, or the like on which a circuit is formed of ITO, IZO, or metal used for a liquid crystal display. As shown in FIG. 1, the second circuit member 3 has a plurality of circuit electrodes 8 corresponding to the bump electrodes 6 on the mounting surface 7 a side of the main body 7. The circuit electrode 8 has a rectangular shape, for example, in plan view, like the bump electrode 6, and has a thickness of, for example, about 100 nm. The surface of the circuit electrode 8 is, for example, one selected from gold, silver, copper, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, indium tin oxide (ITO), and indium zinc oxide (IZO) or It is composed of two or more materials. In the mounting surface 7a, an insulating layer may be formed in a portion where the circuit electrode 8 is not formed.

  The anisotropic conductive film cured product 4 is a layer formed using an anisotropic conductive film 11 (see FIG. 2) described later, and is a first region 9 formed by curing the conductive adhesive layer 13. And the second region 10 formed by curing the insulating adhesive layer 14. In this embodiment, the 1st field 9 is located in the 2nd circuit member 3 side, and the 2nd field 10 is located in the 1st circuit member 2 side. In this embodiment, for convenience of explanation, the layer in which the conductive particles P are dispersed is referred to as a conductive adhesive layer, and the layer in which the conductive particles P are not dispersed is referred to as an insulating adhesive layer. The constituting adhesive component itself is non-conductive.

  The conductive particles P are interposed between the bump electrodes 6 and the circuit electrodes 8 in a state where the conductive particles P are slightly flattened by pressure bonding. Thereby, electrical connection between the bump electrode 6 and the circuit electrode 8 is realized. In addition, the conductive particles P are separated between the adjacent bump electrodes 6 and 6 and between the adjacent circuit electrodes 8 and 8, so that the adjacent bump electrodes 6 and 6 and between the adjacent circuit electrodes 8 and 8 are separated. The electrical insulation is realized.

[Configuration of anisotropic conductive film]
FIG. 2 is a schematic cross-sectional view showing an embodiment of the anisotropic conductive film according to the present invention, and shows the anisotropic conductive film used in the connection structure shown in FIG. As shown in the figure, the anisotropic conductive film 11 includes a release film 12, a conductive adhesive layer 13 composed of an adhesive layer in which conductive particles P are dispersed, and an adhesive in which the conductive particles P are not dispersed. The insulating adhesive layer 14 composed of layers is laminated in this order.

  FIG. 3 is a schematic cross-sectional view showing another embodiment of the anisotropic conductive film according to the present invention. As shown in FIG. 3, the anisotropic conductive film 21 includes a release film 12 and a conductive adhesive layer 13 including an adhesive layer in which conductive particles P are dispersed. As shown in FIG. 3, the anisotropic conductive film of the present invention may have only one layer of the conductive adhesive layer 13 without the insulating adhesive layer 14 as the adhesive layer. Here, the composition of the conductive adhesive layer 13 in the anisotropic conductive film 21 shown in FIG. 3 is the same as the composition of the conductive adhesive layer 13 in the anisotropic conductive film 11 shown in FIG. However, the thickness of the conductive adhesive layer 13 in the anisotropic conductive film 21 shown in FIG. 3 is the same as that of the conductive adhesive layer 13 and the insulating adhesive layer 14 in the anisotropic conductive film 11 shown in FIG. It is the same as the total thickness. In addition, when the connection structure is formed using the anisotropic conductive film 21 shown in FIG. 3, the cured product 4 of the anisotropic conductive film shown in FIG. 1 cures the conductive adhesive layer 13. It is comprised only by the 1st area | region 9 which becomes.

  Hereinafter, each component of the anisotropic conductive film shown in FIGS. 2 and 3 will be described in detail.

  The release film 12 is made of, for example, polyethylene terephthalate (PET), polyethylene, polypropylene, or the like. The release film 12 may contain an arbitrary filler. Further, the surface of the release film 12 may be subjected to a mold release process or a plasma process.

  The adhesive layers that form the conductive adhesive layer 13 and the insulating adhesive layer 14 are at least (a) a film-forming material (hereinafter also referred to as “component (a)”), and (b) an epoxy. A compound or oxetane compound (hereinafter also referred to as “component (b)”), (c) a thiol compound (hereinafter also referred to as “component (c)”), and (d) a curing agent that generates a base by light (hereinafter referred to as “component”). , "(D) component").

  (A) The film-forming material has an effect of facilitating handling of a composition having a low viscosity containing the (b) epoxy compound or oxetane compound, (c) a thiol compound, and (d) a curing agent that generates a base by light. It is a polymer having By using the film-forming material, it is possible to obtain an anisotropic conductive film that can be easily handled by suppressing the film from being easily torn, broken or sticky.

  As the film-forming material of component (a), a thermoplastic resin is preferably used. A phenoxy resin, a polyvinyl formal resin, a polystyrene resin, a polyvinyl butyral resin, a polyester resin, a polyamide resin, a xylene resin, a polyurethane resin, a polyacrylic resin, Polyester urethane resin etc. are mentioned. Furthermore, these polymers may contain siloxane bonds or fluorine substituents. These resins can be used alone or in admixture of two or more. Among the above resins, a phenoxy resin is preferably used from the viewpoints of adhesive strength, compatibility, heat resistance, and mechanical strength.

  As the molecular weight of the thermoplastic resin used as the component (a) is larger, the film-forming property is more easily obtained, and the melt viscosity that affects the fluidity of the anisotropic conductive film can be set in a wide range. The molecular weight of the thermoplastic resin is preferably 5000 to 150,000 in weight average molecular weight, and particularly preferably 10,000 to 80,000. When the weight average molecular weight is 5000 or more, good film formability is easily obtained, and when it is 150,000 or less, good compatibility with other components is easily obtained.

In the present invention, the weight average molecular weight is a value measured from a gel permeation chromatograph (GPC) using a standard polystyrene calibration curve according to the following conditions.
(Measurement condition)
Device: GPC-8020 manufactured by Tosoh Corporation
Detector: RI-8020 manufactured by Tosoh Corporation
Column: Hitachi Chemical Co., Ltd. Gelpack GLA160S + GLA150S
Sample concentration: 120 mg / 3 mL
Solvent: Tetrahydrofuran Injection volume: 60 μL
Pressure: 2.94 × 106 Pa (30 kgf / cm ² )
Flow rate: 1.00 mL / min

  In addition, the content of the (a) film-forming material is the component (a), the component (b), the component (c), and the component (d) independently in the conductive adhesive layer 13 and the insulating adhesive layer 14. It is preferable that it is 5 mass%-80 mass% on the basis of the total amount of, and it is more preferable that it is 15 mass%-70 mass%. When the content is 5% by mass or more, good film formability is easily obtained, and when the content is 80% by mass or less, the adhesive composition when forming the adhesive layer has good fluidity. Tend to show.

As the epoxy compound of component (b), one of epichlorohydrin and bisphenol type epoxy resin derived from at least one selected from the group consisting of bisphenol A, bisphenol F, bisphenol AD, etc., one of epichlorohydrin, phenol novolak and cresol novolak Or an epoxy novolac resin derived from both, a naphthalene epoxy resin having a skeleton containing a naphthalene ring, and two or more glycidyl groups in one molecule such as glycidylamine, glycidyl ether, biphenyl, alicyclic, etc. Various epoxy compounds etc. can be used individually or in combination of 2 or more types. As the epoxy resin, it is preferable to use a high-purity product in which impurity ions (Na ⁺ , Cl ^{− and the} like), hydrolyzable chlorine and the like are reduced to 300 ppm or less from the viewpoint of preventing electromigration.

  Among the above epoxy resins, a bifunctional or higher polyfunctional epoxy resin is preferable in that good curability can be obtained. Among these, bisphenol-type epoxy and trifunctional or higher functional epoxy resins are particularly preferable from the viewpoints of molecular weight control and cured product properties of the resulting cured product.

  In addition, the oxetane compound as the component (b) preferably includes an oxetane compound having 1 to 4 oxetane rings in the molecule.

  Examples of the oxetane compound having one oxetane ring include compounds represented by the following general formula (5).

In the general formula (5), R ⁵ represents a hydrogen atom, a methyl group, an ethyl group, a propyl group or a butyl group, such as an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, or an allyl group. An aryl group, a furyl group or a thienyl group. R ⁶ represents an alkyl group having 1 to 6 carbon atoms such as methyl group, ethyl group, propyl group or butyl group, 1-propenyl group, 2-propenyl group, 2-methyl-1-propenyl group, 2-methyl- C2-C6 alkenyl group such as 2-propenyl group, 1-butenyl group, 2-butenyl group or 3-butenyl group, phenyl group, benzyl group, fluorobenzyl group, methoxybenzyl group or phenoxyethyl group A group having an aromatic ring, an alkylcarbonyl group having 2 to 6 carbon atoms such as an ethylcarbonyl group, a propylcarbonyl group or a butylcarbonyl group, an alkylcarbonyl group having 2 to 6 carbon atoms such as an ethoxycarbonyl group, a propoxycarbonyl group or a butoxycarbonyl group; Alkoxycarbonyl group, ethylcarbamoyl group, propylcarbamoyl group, butylcarbamo And an N-alkylcarbamoyl group having 2 to 6 carbon atoms such as an yl group or a pentylcarbamoyl group.

  Examples of the oxetane compound having two oxetane rings include a compound represented by the following general formula (6).

In the general formula (6), R ⁵ is the same group as that in the general formula (5). R ⁷ is, for example, a linear or branched poly (alkyleneoxy) such as a linear or branched alkylene group such as an ethylene group, a propylene group or a butylene group, a poly (ethyleneoxy) group or a poly (propyleneoxy) group. ) Group, propenylene group, methylpropenylene group or butenylene group or other linear or branched unsaturated hydrocarbon group, carbonyl group, alkylene group containing carbonyl group, alkylene group containing carboxyl group or alkylene group containing carbamoyl group Etc.

R ⁷ may be a polyvalent group selected from the groups represented by the following general formulas (7) to (19). Among these, the group represented by the formula (14) is preferable from the viewpoint of curability and peeling prevention.

In the general formula (7), R ⁸ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a methoxy group, an ethoxy group, a propoxy group or a butoxy group. An alkoxy group having 1 to 4 carbon atoms, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group.

In the general formula (8), R ⁹ is an oxygen atom, a sulfur atom, a methylene group, an amino group, a sulfonyl group, a bis (trifluoromethyl) methylene group, or a dimethylmethylene group.

In the general formula (9), R ¹⁰ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a methoxy group, an ethoxy group, a propoxy group or a butoxy group. An alkoxy group having 1 to 4 carbon atoms, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group.

In the general formula (10), R ¹¹ is an oxygen atom, a sulfur atom, a methylene group, an amino group, a sulfonyl group, a bis (trifluoromethyl) methylene group, a dimethylmethylene group, a phenylmethylmethylene group, or a biphenylmethylene group. .

In General Formula (11) and General Formula (12), R ¹² represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, a methoxy group, an ethoxy group, or a propoxy group. An alkoxy group having 1 to 4 carbon atoms such as a group or a butoxy group, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group or a carbamoyl group. Further, R ¹² may be substituted at 2 to 4 positions of the naphthalene ring.

Preferable examples other than the compounds described above for the oxetane compound having two oxetane rings include compounds represented by the following general formula (20). In general formula (20), R ⁵ is the same group as in general formula (5).

  Examples of the oxetane compound having 3 to 4 oxetane rings include compounds represented by the following general formula (21).

In General Formula (21), R ⁵ is the same group as in General Formula (5), and m is 3 or 4. Examples of R ¹³ include a branched alkylene group having 1 to 12 carbon atoms such as groups represented by the following general formula (22), formula (23), and formula (24), and the following general formula (25). And branched poly (alkyleneoxy) groups such as groups.

一般式（２２）において、Ｒ^１４はメチル基、エチル基又はプロピル基等の低級アルキル基である。

In the general formula (22), R ¹⁴ is a lower alkyl group such as a methyl group, an ethyl group, or a propyl group.

一般式（２５）において、ｐは１〜１０の整数である。

In General formula (25), p is an integer of 1-10.

  Preferable specific examples of the oxetane compound used in the present invention include a compound represented by the following formula (26).

  Moreover, as an oxetane compound, the oxetane compound which has the comparatively high molecular weight 1-4 oxetane ring of molecular weight about 1,000-5,000 other than what was mentioned above is mentioned. Furthermore, as a polymer containing oxetane, a polymer having an oxetane ring in the side chain can be used similarly. In the present invention, one oxetane compound can be used alone, or two or more oxetane compounds can be used in combination.

43-1000 are preferable, as for the oxetane equivalent of an oxetane compound, 50-800 are more preferable, and 73-600 are especially preferable. When the oxetane equivalent is less than 43 or exceeds 1000, the adhesive strength between the electrodes tends to decrease. For these oxetane compounds, it is preferable to use a high-purity product in which impurity ions (Na ⁺ , Cl ^−, etc.) and hydrolyzable chlorine are reduced to 300 ppm or less.

  The content of the epoxy compound and the oxetane compound is 5 to 50 parts by mass with respect to 100 parts by mass of the total mass of each adhesive layer independently in the conductive adhesive layer 13 and the insulating adhesive layer 14. Preferably, it is 20-40 mass parts. When the content of the epoxy resin and the oxetane compound is 5 parts by mass or more, there is a tendency that a decrease in the fluidity of the anisotropic conductive film can be suppressed when the circuit members are pressure-bonded. Sometimes, there is a tendency that deformation of the anisotropic conductive film can be suppressed. In addition, the epoxy compound and the oxetane compound may be used in combination, and two or more types may be selected and blended.

  As the thiol compound of component (c), a polythiol compound having two or more thiol groups is preferably used. For example, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2 , 3-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,10-decanedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 4, 4′-thiobisbenzenethiol, 4,4′-biphenyldithiol, 1,5-dimercaptonaphthalene, 4,5-bis (mercaptomethyl) -ortho-xylene, 1,3,5-benzenetrithiol, 1, 4-butanediol bis (thioglycolate), dithioethitol, 3,6-dioxa-1, -Octanedithiol, 3,7-dithia-1,9-nonanedithiol, bis (2-mercaptoethyl) sulfide, ethylene glycol bis (mercaptoacetate), ethylene glycol bis (3-mercaptopropionate), ethylene glycol bis ( 3-mercaptobutyrate), ethylene glycol bis (3-mercaptoisobutyrate), butanediol bis (mercaptoacetate), butanediol bis (3-mercaptopropionate), butanediol bis (3-mercaptobutyrate), Butanediol bis (3-mercaptoisobutyrate), pentaerythritol tri (mercaptoacetate), pentaerythritol tri (3-mercaptopropionate), pentaerythritol tri (3-mercaptobutyrate) ), Pentaerythritol tris (3-mercaptoisobutyrate), pentaerythritol tetrakis (mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptoisobutyrate), trimethylolethane (mercaptoacetate), trimethylolethane (3-mercaptopropionate), trimethylolethane (3-mercaptobutyrate), trimethylolethane (3-mercaptoisobutyrate) ), Trimethylolpropane tris (mercaptoacetate), trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (3-methyl) Lucaptobutyrate), trimethylolpropane tris (3-mercaptoisobutyrate), dipentaerythritol hexakis (mercaptoacetate), dipentaerythritol hexakis (3-mercaptopropionate), dipentaerythritol hexakis (3 -Mercaptobutyrate), dipentaerythritol hexakis (3-mercaptoisobutyrate), 1,4-bis (3-mercaptopropyloxy) butane, 1,4-bis (3-mercaptobutyryloxy) butane, , 3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, tris [(3-mercaptopropionyloxy) ethyl] isocyanate Nurate, tetraethylene glycol bis (3- Le mercaptopropionate) thiol group and the like polythiol compound having 2 to 5. Of these, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) in consideration of reactivity and ease of handling ) -Trione, tris [(3-mercaptopropionyloxy) ethyl] isocyanurate is preferably used. These thiol compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the thiol compound is independently in each of the conductive adhesive layer 13 and the insulating adhesive layer 14 (b) thiol equivalent (SH equivalent): epoxy equivalent (or oxetane equivalent) with respect to the epoxy compound or oxetane compound. ) = 2: 8 to 8: 2 is preferable, and a ratio of 3: 7 to 7: 3 is more preferable. If this ratio is in the range of 2: 8 to 8: 2, it is possible to prevent a large amount of unreacted thiol group and epoxy group (or oxetane group) from remaining in the cured product, and the mechanical properties of the cured product. There is a tendency to be able to suppress the decrease of the.

  The curing agent that generates a base by light as the component (d) includes a carboxylate represented by the following general formula (1).

一般式（１）中、ＲはＣＨ_３又はＨを示し、Ｘはアミジン類、グアニジン類、又はホスファゼン誘導体から選ばれる塩基類を示す。

In the general formula (1), R represents CH ₃ or H, and X represents a base selected from amidines, guanidines, or phosphazene derivatives.

一般式（２７）中のＲはＣＨ_３又はＨを示す。本実施形態で用いるカルボン酸の例としては、式（２７）の化合物のＲがＣＨ_３である、２−（９−オキソキサンテン−２−イル）プロピオン酸を好適に用いることができる。この化合物は、光照射によって脱炭酸を引き起こすカルボン酸の中で高い光脱炭酸効率を有しており、３６５ｎｍにおいても波長吸収領域を有している。よって、カルボン酸として、２−（９−オキソキサンテン−２−イル）プロピオン酸を用いることで、極めて高効率に塩基を発生させることができる。 The carboxylate represented by the general formula (1) is composed of a carboxylic acid that is decarboxylated by light irradiation represented by the following general formula (27) and a base composed of any of amidines, guanidines, and phosphazene derivatives. A compound comprising a carboxylate.

R in the general formula (27) represents CH ₃ or H. As an example of the carboxylic acid used in the present embodiment, 2- (9-oxoxanthen-2-yl) propionic acid in which R of the compound of the formula (27) is CH ₃ can be suitably used. This compound has high photodecarboxylation efficiency among carboxylic acids that cause decarboxylation by light irradiation, and also has a wavelength absorption region at 365 nm. Therefore, a base can be generated with extremely high efficiency by using 2- (9-oxoxanthen-2-yl) propionic acid as the carboxylic acid.

Examples of amidines that can be used as bases include compounds represented by the following formula (2).

Moreover, as a guanidine which can be used as bases, the compound shown by following formula (3-1) or formula (3-2) can be used, for example.

Furthermore, examples of the phosphazene derivative that can be used as a base include compounds represented by the following formula (4-1), formula (4-2), formula (4-3), or formula (4-4). Can be used.

  These bases have high acid dissociation constants (pKa), and the compounds represented by formula (2) are generally 12 to 13, formulas (3-1) to (3-2), and formulas (4-1) to The compound represented by (4-4) exceeds 13.5, has very high basicity, and high reactivity can be expected.

  Accordingly, in 2- (9-oxoxanthen-2-yl) propionic acid and formula (2), formula (3-1) to (3-2), or formula (4-1) to (4-4) A curing agent composed of a salt with the indicated base can obtain high reactivity when irradiated with light.

  (D) The content of the curing agent that generates a base by light is determined independently between (b) the epoxy compound or oxetane compound and (c) the thiol compound in the conductive adhesive layer 13 and the insulating adhesive layer 14. It is preferable that it is 0.5-30 mass parts with respect to a total of 100 mass parts. When the content of the component (d) is 0.5 parts by mass or more, the (b) epoxy compound or oxetane compound can be sufficiently reacted, and a good cured product tends to be obtained stably. . When the content of the component (d) is 30 parts by mass or less, good physical properties of the cured product tend to be obtained. In addition, although high reactivity will be obtained when content of (d) component exceeds 30 mass parts, it is preferable to set it as 30 mass parts or less from the point of the physical property of hardened | cured material. In order to achieve both curability and good cured properties, the content of the component (d) is more preferably 1 to 30 parts by mass, further preferably 3 to 25 parts by mass, and 5 to 15 parts by mass. It is particularly preferable that

  The adhesive layer forming the conductive adhesive layer 13 and the insulating adhesive layer 14 is composed of a base proliferating agent, a filler, a softening agent, an accelerator, an anti-aging agent, a coloring agent, a flame retardant, a thixotropic. May further contain an agent, a coupling agent, a phenol resin, a melamine resin, isocyanates, and the like.

  When the adhesive layer contains a filler, further improvement in connection reliability can be expected. The maximum diameter of the filler is preferably less than the particle diameter of the conductive particles. Content of a filler is 5 volume with respect to a total of 100 volume parts of (a) component, (b) component, and (c) component each independently with the conductive adhesive layer 13 and the insulating adhesive layer 14. It is preferable that it is a part-60 volume part. If this content exceeds 60 parts by volume, the effect of improving reliability may be saturated, and if it is less than 5 parts by volume, the effect of addition is small.

  The anisotropic conductive film may contain conductive particles P. In the anisotropic conductive films 11 and 21, the conductive particles P are contained in the conductive adhesive layer 13.

  Examples of the conductive particles P include metal particles such as Au, Ag, Ni, Cu, and solder, and carbon. In order to obtain sufficient storage stability, the surface layer is not a transition metal such as Ni or Cu. Au, Ag and platinum group noble metals are preferred, and Au is more preferred. Further, the surface of a transition metal such as Ni may be coated with a noble metal such as Au. Further, non-conductive glass, ceramics, plastics and the like coated with a conductive material such as the above metal can be used. In this case, the outermost layer is preferably a noble metal.

  If conductive particles such as non-conductive plastic coated with conductive material or hot-melt metal particles are used, these conductive particles are deformed by heat and pressure, increasing the contact area with the electrode during connection. However, it is preferable because the thickness variation of the circuit terminals of the circuit member is absorbed and the connection reliability tends to be improved.

  The thickness of the noble metal coating layer is preferably 10 nm or more from the viewpoint of obtaining good resistance. On the other hand, when a noble metal layer is provided on a transition metal such as Ni, free radicals are generated due to redox action caused by a deficiency in the noble metal layer and a deficiency in the noble metal layer generated when the conductive particles P are mixed and dispersed. Since the storage stability tends to be lowered, the thickness of the coating layer is preferably 30 nm or more from the viewpoint of preventing this. In addition, although the upper limit of the thickness of a coating layer is not restrict | limited in particular, Since the effect acquired is saturated, it is preferable to set it as 1 micrometer or less.

  The content of the conductive particles P is preferably 0.1 to 50 parts by volume with respect to a total of 100 parts by volume of the component (a), the component (b), and the component (c). It is preferable to adjust accordingly. In addition, it is more preferable that the content is 0.1 to 40 parts by volume from the viewpoint of preventing a short circuit of an adjacent circuit due to the presence of excessive conductive particles.

  A sensitizer can be added to the adhesive layer of the anisotropic conductive film of this embodiment in order to expand the photosensitive wavelength region and increase the sensitivity. The sensitizer that can be used is not particularly limited. For example, benzophenone, p, p′-tetramethyldiaminobenzophenone, p, p′-tetraethylaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, anthracene. , Pyrene, perylene, phenothiazine, benzyl, acridine orange, benzoflavin, cetoflavin-T, 9,10-diphenylanthracene, 9-fluorenone, acetophenone, phenanthrene, 2-nitrofluorene, 5-nitroacenaphthene, benzoquinone, 2-chloro -4-nitroaniline, N-acetyl-p-nitroaniline, p-nitroaniline, N-acetyl-4-nitro-1-naphthylamine, picramide, anthraquinone, 2-ethylanthraquinone, 2 tert-butylanthraquinone, 1,2-benzanthraquinone, 3-methyl-1,3-diaza-1,9-benzanthrone, dibenzalacetone, 1,2-naphthoquinone, 3,3′-carbonyl-bis (5 , 7-dimethoxycarbonylcoumarin) or coronene. These sensitizers may be used alone or in combination of two or more.

  A silane coupling agent can be added to the adhesive layer of the anisotropic conductive film of this embodiment from the viewpoint of improving the adhesion of the circuit board. Examples of the silane coupling agent include ketimine groups, vinyl groups, acrylic groups, amino groups, epoxy groups, and isocyanate group-containing silane coupling agents. These can be used individually by 1 type or in combination of 2 or more types. When the silane coupling agent is contained in the adhesive layer, the content is 100 parts by weight of the total of the component (a), the component (b) and the component (c), and the addition effect and the ability to form the adhesive layer. From the viewpoint of coexistence, it is preferably 0.5 to 30 parts by mass, and more preferably 1 to 20 parts by mass.

  In the anisotropic conductive film, the thickness of the conductive adhesive layer 13 is preferably 2 μm to 10 μm, preferably 3 μm to 8 μm, from the viewpoint of obtaining good connection reliability by particles captured between the opposing circuits. It is more preferable.

  The thickness of the insulating adhesive layer 14 can be set as appropriate. The total thickness of the conductive adhesive layer 13 and the insulating adhesive layer 14 is preferably, for example, 5 μm to 30 μm. Also, usually, the total thickness of the conductive adhesive layer 13 and the insulating adhesive layer 14 and from the mounting surface 5a of the first circuit member 2 to the mounting surface 7a of the second circuit member 3 in the connection structure 1. The difference from the above distance (a value obtained by subtracting the distance from the total thickness) is preferably 0 μm to 10 μm. From the viewpoint of filling the space between the first and second circuit members 2 and 3 with the cured product 4 of the anisotropic conductive film, the above difference is preferably 0.5 μm to 8.0 μm, and 1.0 μm to More preferably, the thickness is 5.0 μm.

[Method of manufacturing connection structure]
Next, an embodiment of a method for manufacturing a connection structure according to the present invention will be described. In the following description, a case where the connection structure 1 shown in FIG. 1 is manufactured using the anisotropic conductive film 11 shown in FIG. 2 will be described as an example.

  FIG. 4 is a schematic cross-sectional view showing a manufacturing process of the connection structure shown in FIG. In forming the connection structure 1, first, the release film 12 is peeled from the anisotropic conductive film 11, and the anisotropic conductive film 11 is then placed so that the conductive adhesive layer 13 side faces the mounting surface 7 a. Is laminated on the circuit member 3. Next, as shown in FIG. 5, the first circuit member 2 is arranged on the second circuit member 3 on which the anisotropic conductive film 11 is laminated so that the bump electrode 6 and the circuit electrode 8 face each other. To do. And while heating the anisotropic conductive film 11, the 1st circuit member 2 and the 2nd circuit member 3 are pressurized in the thickness direction, and also ultraviolet rays are applied to the back surface of the second circuit member 3 (second circuit member). 3 is irradiated from the surface opposite to the anisotropic conductive film 11.

  Thereby, the adhesive component of the anisotropic conductive film 11 flows, the conductive adhesive layer 13 and the insulating adhesive are in a state where the distance between the bump electrode 6 and the circuit electrode 8 is reduced and the conductive particles P are engaged. Layer 14 is cured. By curing the conductive adhesive layer 13 and the insulating adhesive layer 14, the bump electrode 6 and the circuit electrode 8 are electrically connected, and the adjacent bump electrodes 6, 6 and the adjacent circuit electrodes 8, 8 are mutually connected. The cured product 4 of the anisotropic conductive film is formed in a state where is electrically insulated, and the connection structure 1 shown in FIG. 1 is obtained. In the obtained connection structure 1, the cured product 4 of the anisotropic conductive film sufficiently prevents the change in the distance between the bump electrode 6 and the circuit electrode 8 over time, and the long-term reliability of the electrical characteristics. Can also be secured.

  In addition, it is preferable that the heating temperature of the anisotropic conductive film 11 is more than the temperature which superposition | polymerization of an epoxy compound or an oxetane compound and a thiol compound advances with the base generate | occur | produced with the ultraviolet-ray. This heating temperature is, for example, 30 ° C to 200 ° C, and preferably 40 ° C to 180 ° C. The heating time is, for example, 0.1 second to 30 seconds, preferably 1 second to 20 seconds. When the heating temperature is less than 30 ° C, the curing rate is slow, and when it exceeds 180 ° C, unwanted side reactions tend to proceed. Further, if the heating time is less than 0.1 seconds, the curing reaction does not proceed sufficiently, and if it exceeds 30 seconds, the productivity of the cured product is lowered, and further unwanted side reactions are likely to proceed.

Irradiation with ultraviolet rays may be started simultaneously with pressurization of the first circuit member 2 and the second circuit member 3 in the thickness direction, but in terms of causing the adhesive component of the anisotropic conductive film 11 to flow. The irradiation start time is preferably after the heating and pressing start time and delayed by 0.1 to 4 seconds from the heating and pressing start time. When the irradiation start time is delayed by 4 seconds or more, the resin may flow excessively and a gap may be formed between the first circuit member 2 and the second circuit member 3, resulting in a decrease in adhesiveness and connection reliability. It may cause a decrease in. Furthermore, the irradiation start time is preferably delayed by 1 to 3 seconds from the heating and pressurization start time. In this case, the meshing state of the conductive particles becomes good. Further, the ultraviolet irradiation amount is not particularly limited as long as (d) the irradiation amount sufficient to generate a base from a curing agent that generates a base by light, and since it differs depending on the type and content of the curing agent, Although it cannot be said, it is 50-2000 mJ / cm < ² > normally, Preferably it is 100-1000 mJ / cm < ² >.

  Next, other embodiment of the manufacturing method of the connection structure of the present invention is described. When the connection structure 1 shown in FIG. 1 is formed by the manufacturing method of the present embodiment, first, as shown in FIG. 4, the release film 12 is peeled from the anisotropic conductive film 11, and the conductive adhesive layer 13. After the anisotropic conductive film 11 is laminated on the second circuit member 3 so that the side faces the mounting surface 7a, ultraviolet rays are irradiated. Although the base is generated from the curing agent that generates a base by (d) light in the anisotropic conductive film 11 by irradiation of ultraviolet rays, since heating is not performed, in this state, the anisotropic conductive film 11 Curing does not proceed. Next, as shown in FIG. 5, the first circuit member 2 is arranged on the second circuit member 3 on which the anisotropic conductive film 11 is laminated so that the bump electrode 6 and the circuit electrode 8 face each other. To do. Then, the first circuit member 2 and the second circuit member 3 are pressed in the thickness direction while heating the anisotropic conductive film 11.

  Thereby, the adhesive component of the anisotropic conductive film 11 flows, the conductive adhesive layer 13 and the insulating adhesive are in a state where the distance between the bump electrode 6 and the circuit electrode 8 is reduced and the conductive particles P are engaged. Layer 14 is cured. By curing the conductive adhesive layer 13 and the insulating adhesive layer 14, the bump electrode 6 and the circuit electrode 8 are electrically connected, and the adjacent bump electrodes 6, 6 and the adjacent circuit electrodes 8, 8 are mutually connected. The cured product 4 of the anisotropic conductive film is formed in a state where is electrically insulated, and the connection structure 1 shown in FIG. 1 is obtained. In the obtained connection structure 1, the cured product 4 of the anisotropic conductive film sufficiently prevents the change in the distance between the bump electrode 6 and the circuit electrode 8 over time, and the long-term reliability of the electrical characteristics. Can also be secured.

  In addition, it is preferable that the heating temperature of the anisotropic conductive film 11 is more than the temperature which superposition | polymerization of an epoxy compound or an oxetane compound and a thiol compound advances with the base generate | occur | produced with the ultraviolet-ray. This heating temperature is, for example, 30 ° C to 200 ° C, and preferably 40 ° C to 180 ° C. The heating time is, for example, 0.1 second to 30 seconds, preferably 1 second to 20 seconds. When the heating temperature is less than 30 ° C, the curing rate is slow, and when it exceeds 180 ° C, unwanted side reactions tend to proceed. Further, if the heating time is less than 0.1 seconds, the curing reaction does not proceed sufficiently, and if it exceeds 30 seconds, the productivity of the cured product is lowered, and further unwanted side reactions are likely to proceed.

Further, the ultraviolet irradiation amount is not particularly limited as long as (d) the irradiation amount sufficient to generate a base from a curing agent that generates a base by light, and since it differs depending on the type and content of the curing agent, Although it cannot be said, it is 50-2000 mJ / cm < ² > normally, Preferably it is 100-1000 mJ / cm < ² >.

[Method of manufacturing anisotropic conductive film]
The anisotropic conductive film can be produced by applying an adhesive paste as a material for forming the conductive adhesive layer 13 on the release film 12 and drying it.

  The viscosity of the adhesive paste can be varied depending on the application and application method, but it is usually preferably 10 mPa · s to 10000 mPa · s. From the viewpoint of suppressing the separation of the compound in the adhesive paste and improving the compatibility, it is more preferably 50 mPa · s to 5000 mPa · s. Moreover, it is preferable to set it as 100 mPa * s-3000 mPa * s for the external appearance improvement of an anisotropic conductive film.

  A known method can be used as a method for applying the adhesive paste. For example, spin coating method, roller coating method, bar coating method, dip coating method, micro gravure coating method, curtain coating method, die coating method, spray coating method, doctor coating method, kneader coating method, flow coating method, screen printing method, casting Law. A bar coating method, a die coating method, a micro gravure coating method and the like are suitable for producing an anisotropic conductive film, and the die coating method is particularly suitable from the viewpoint of the accuracy of the film thickness.

  The drying temperature of the adhesive paste is preferably 20 ° C to 100 ° C, for example. If the temperature is lower than 20 ° C, drying may be insufficient. If the temperature is higher than 100 ° C, the compound in the anisotropic conductive film may cause an unexpected reaction.

  After the formation of the conductive adhesive layer 13, an anisotropic conductive film having a two-layer structure in which an insulating adhesive layer 14 produced separately is laminated on the conductive adhesive layer 13 may be used. For laminating the insulating adhesive layer 14, for example, a hot roll laminator can be used. Further, the present invention is not limited to laminating, and an adhesive paste as a material for the insulating adhesive layer 14 may be applied and dried on the conductive adhesive layer 13.

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

  For example, in the anisotropic conductive film 11 shown in FIG. 2, the arrangement of the conductive adhesive layer 13 and the insulating adhesive layer 14 may be reversed. That is, the insulating adhesive layer 14 and the conductive adhesive layer 13 may be laminated on the release film 12 in this order.

  Moreover, in the anisotropic conductive film 11 shown in FIG. 2, only one adhesive layer of the conductive adhesive layer 13 and the insulating adhesive layer 14 is the component (a) and the component (b) described above. , (C) and a layer containing the component (d) may be used.

  Further, the anisotropic conductive film may be composed of a release film 12 and an insulating adhesive layer 14 formed on the release film 12.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

<Synthesis of a curing agent that generates a base by light (photobase generator)>
(Synthesis Example 1)
To a tetrahydrofuran solution (20 mL) of 5.36 g (20.0 mmol) of 2- (9-oxoxanthen-2-yl) propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1,8-diazabicyclo [5,4,0] undeca- A tetrahydrofuran solution (20 mL) of 7-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) in an amount of 3.04 g (20.0 mmol) was added dropwise and stirred at room temperature for 1 hour. Then, the solvent was distilled off under reduced pressure, impurities were extracted and removed using diethyl ether as a poor solvent and tetrahydrofuran as a good solvent, and 2,8-diazabicyclo [5]-(9-oxoxanthen-2-yl) propionic acid was removed. , 4,0] Undec-7-ene salt (photobase generator 1) was obtained in an amount of 4.38 g (yield 52%).

(Synthesis Example 2)
To a tetrahydrofuran solution (20 mL) of 5.36 g (20.0 mmol) of 2- (9-oxoxanthen-2-yl) propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1,5,7-triazabicyclo [4,4, 0] A tetrahydrofuran solution (20 mL) of 2.78 g (20.0 mmol) of deca-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise and stirred at room temperature for 1 hour. Thereafter, the solvent was distilled off under reduced pressure, and impurities were extracted and removed using diethyl ether as a poor solvent and tetrahydrofuran as a good solvent, and 2,5- (9-oxoxanthen-2-yl) propionic acid 1,5,7-tria was obtained. 5.06 g (yield 62%) of zabicyclo [4,4,0] dec-5-ene salt (photobase generator 2) was obtained.

(Synthesis Example 3)
To a tetrahydrofuran solution (20 mL) of 5.36 g (20.0 mmol) of 2- (9-oxoxanthen-2-yl) propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 7-methyl-1,5,7-triazabicyclo [ A tetrahydrofuran solution (20 mL) of 3.06 g (20.0 mmol) of 4,4,0] dec-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise and stirred at room temperature for 1 hour. Thereafter, the solvent was distilled off under reduced pressure, impurities were extracted and removed using diethyl ether as a poor solvent and tetrahydrofuran as a good solvent, and 7-methyl-1,5- (9-oxoxanthen-2-yl) propionate. , 7-triazabicyclo [4,4,0] dec-5-ene salt (photobase generator 3) was obtained in an amount of 4.12 g (yield 49%).

(Synthesis Example 4)
To a tetrahydrofuran solution (10 mL) of 5.36 g (20.0 mmol) of 2- (9-oxoxanthen-2-yl) propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), tert-butylimino-tris (dimethylamino) phosphorane (SIGMA-ALDRICH) (Product) 2.34 g (10.0 mmol) of a tetrahydrofuran solution (10 mL) was added dropwise, and the mixture was stirred at room temperature for 1 hour. Thereafter, the solvent was distilled off under reduced pressure, and impurities were extracted and removed using diethyl ether as a poor solvent and tetrahydrofuran as a good solvent, and tert-butylimino-tris 2-dimethyl (9-oxoxanthen-2-yl) propionate (dimethyl). 1.90 g (yield 38%) of amino) phosphorane salt (photobase generator 4) was obtained.

(Synthesis Example 5)
To a tetrahydrofuran solution (20 mL) of 5.08 g (20.0 mmol) of 2- (3-benzoylphenyl) propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1,5,7-triazabicyclo [4,4,0] deca- A tetrahydrofuran solution (20 mL) of 2.78 g (20.0 mmol) of 5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise and stirred at room temperature for 1 hour. Thereafter, the solvent was distilled off under reduced pressure, and impurities were extracted and removed using diethyl ether as a poor solvent and tetrahydrofuran as a good solvent, and 2,5- (3-benzoylphenyl) propionic acid 1,5,7-triazabicyclo [4 , 4,0] dec-5-ene salt (photobase generator 5) was obtained 4.56 g (yield 58%).

<Production of anisotropic conductive film>
Example 1
As a film-forming material, phenoxy resin (product name: YP-70, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), as an epoxy compound, bisphenol A type epoxy resin (product name: 828, manufactured by Mitsubishi Chemical Corporation), as a thiol compound, penta Erythritol tetrakis (3-mercaptobutyrate) (product name: Karenz MT PE1, manufactured by Showa Denko KK), photobase generator 1 synthesized in Synthesis Example 1 as photobase generator, 3-methacryloxy as silane coupling agent Propyltrimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) was used. As conductive particles, 35 parts by volume of Ni-plated polystyrene particles (average particle size: 3 μm) was used. Each component was mix | blended so that it might become the mixing ratio shown in Table 1, and the adhesive composition was prepared. The thickness of the adhesive layer (conductive adhesive layer) is obtained by applying the adhesive composition to a PET film having a thickness of 50 μm on one surface using a coating apparatus and drying it with hot air at 70 ° C. for 5 minutes. An anisotropic conductive film of 20 μm was obtained.

(Example 2)
As a thiol compound, 1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (product name: Karenz MT NR1 An anisotropic conductive film was obtained in the same manner as in Example 1 except that Showa Denko) was used.

(Example 3)
An anisotropic conductive film was obtained in the same manner as in Example 1 except that a polyfunctional epoxy resin (product name: 1032H60, manufactured by Mitsubishi Chemical Corporation) was used as the epoxy compound.

Example 4
As a thiol compound, 1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (product name: Karenz MT NR1 An anisotropic conductive film was obtained in the same manner as in Example 3 except that Showa Denko) was used.

(Example 5)
An anisotropic conductive film was obtained in the same manner as in Example 2 except that biphenylenebisoxetane (product name: OXBP, manufactured by Ube Industries) was used as the oxetane compound.

(Example 6)
An anisotropic conductive film was obtained in the same manner as in Example 4 except that the photobase generator 2 synthesized in Synthesis Example 2 was used as the photobase generator.

(Example 7)
An anisotropic conductive film was obtained in the same manner as in Example 4 except that the photobase generator 3 synthesized in Synthesis Example 3 was used as the photobase generator.

(Example 8)
An anisotropic conductive film was obtained in the same manner as in Example 4 except that the photobase generator 4 synthesized in Synthesis Example 4 was used as the photobase generator.

(Examples 9 to 12)
An anisotropic conductive film was obtained in the same manner as in Example 4 except that the amount of the epoxy compound was as shown in Table 1.

(Comparative Example 1)
As an epoxy compound, anisotropic conductivity was obtained in the same manner as in Example 1 except that 50 parts by mass of bisphenol A type epoxy resin (product name: 828, manufactured by Mitsubishi Chemical Corporation) was used and no thiol compound was added. A film was obtained.

(Comparative Example 2)
As Example 1, except that 50 parts by mass of pentaerythritol tetrakis (3-mercaptobutyrate) (product name: Karenz MT PE1, manufactured by Showa Denko) was used as the thiol compound and no epoxy compound was blended. Thus, an anisotropic conductive film was obtained.

(Comparative Example 3)
An anisotropic conductive film was obtained in the same manner as in Example 4 except that the photobase generator 5 synthesized in Synthesis Example 5 was used as the photobase generator.

(Comparative Example 4)
Instead of the photobase generator, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate (product name: PI-2074, manufactured by Rhodia) was used as the photoacid generator. Except for this, an anisotropic conductive film was obtained in the same manner as in Example 1.

  In Table 1, each numerical value represents part by mass, excluding conductive particles. The numerical value of the conductive particles represents a volume part relative to 100 parts by volume in total of the film forming material, the epoxy compound or the oxetane compound, and the thiol compound.

(Evaluation of storage stability)
The anisotropic conductive films of Examples 1 to 12 and Comparative Examples 1 to 4 were left in a thermostat at 40 ° C. for 5 days. After standing, the infrared absorption spectrum of each anisotropic conductive film was measured, and the conversion rate of the cyclic ether of the epoxy compound (or oxetane compound) was calculated. The results are shown in Tables 2 to 4, where the conversion rate of the cyclic ether is less than 5%, ◯ is 5% or more and less than 10%, and 10% or more is x.

(Production of connection structure (production method A))
As a first circuit member, an IC chip having a straight arrangement structure in which bump electrodes are arranged in a line (outer dimensions 2 mm × 20 mm, thickness 0.55 mm, bump electrode size 100 μm × 30 μm, distance between bump electrodes 8 μm, bump electrode thickness 15 μm) was prepared. In addition, as a second circuit member, an ITO wiring pattern (pattern width 21 μm, interelectrode space 17 μm) formed on the surface of a glass substrate (Corning Inc .: # 1737, 38 mm × 28 mm, thickness 0.3 mm) Got ready.

For the connection between the IC chip and the glass substrate, a thermocompression bonding apparatus comprising a quartz stage (150 mm × 150 mm) made of a ceramic heater, a tool (3 mm × 20 mm), and an LED light source that generates ultraviolet light having a wavelength of 365 nm was used. First, the surface on the side of the conductive adhesive layer of the anisotropic conductive films (2.5 mm × 25 mm) according to Examples 1 to 12 and Comparative Examples 1 to 4 is applied to a glass substrate at 80 ° C. and 0.98 MPa (10 kgf / cm). ^The film was pasted by heating and pressing for 2 seconds under the condition ² ).

Next, after peeling the release film on the conductive adhesive layer of the anisotropic conductive film and aligning the bump electrode of the IC chip with the circuit electrode of the glass substrate, the actual measurement of the anisotropic conductive film The conductive adhesive layer is formed as an IC chip by heating for 5 seconds under the conditions of an ultimate temperature of 80 ° C., an ultraviolet intensity of 200 mW / cm ² , and an area-converted pressure of 70 MPa at the bump electrode, and ultraviolet irradiation from the glass stage side. Pasted on. Here, the ultraviolet irradiation was carried out for 3 seconds starting 2 seconds after the heating and pressing start time.

(Production of connection structure (production method B))
As a first circuit member, an IC chip having a straight arrangement structure in which bump electrodes are arranged in a line (outer dimensions 2 mm × 20 mm, thickness 0.55 mm, bump electrode size 100 μm × 30 μm, distance between bump electrodes 8 μm, bump electrode thickness 15 μm) was prepared. In addition, as a second circuit member, an aluminum wiring pattern (pattern width 21 μm, interelectrode space 17 μm) formed on the surface of a glass substrate (manufactured by Corning: # 1737, 38 mm × 28 mm, thickness 0.3 mm) Got ready.

For the connection between the IC chip and the glass substrate, a thermocompression bonding apparatus comprising a quartz stage (150 mm × 150 mm) made of a ceramic heater, a tool (3 mm × 20 mm), and an LED light source that generates ultraviolet light having a wavelength of 365 nm was used. First, the surface on the side of the conductive adhesive layer of the anisotropic conductive films (2.5 mm × 25 mm) according to Examples 1 to 12 and Comparative Examples 1 to 4 is applied to a glass substrate at 80 ° C. and 0.98 MPa (10 kgf / cm). ^The film was pasted by heating and pressing for 2 seconds under the condition ² ).

Next, after peeling off the release film on the conductive adhesive layer of the anisotropic conductive film and irradiating 300 mJ / cm ² ultraviolet rays from the upper surface of the anisotropic conductive film, the bump electrode of the IC chip and the circuit of the glass substrate The alignment with the electrode was performed. Thereafter, the insulating adhesive layer was attached to the IC chip by heating and pressurizing for 5 seconds under the conditions of an actually measured maximum temperature of 80 ° C. of the anisotropic conductive film and an area conversion pressure of 70 MPa at the bump electrode.

(Production of connection structure (production method C))
As a first circuit member, an IC chip having a straight arrangement structure in which bump electrodes are arranged in a line (outer dimensions 2 mm × 20 mm, thickness 0.55 mm, bump electrode size 100 μm × 30 μm, distance between bump electrodes 8 μm, bump electrode thickness 15 μm) was prepared. In addition, as a second circuit member, a substrate (38 mm × 28 mm, base material thickness 0.125 mm) on which a polyimide film (manufactured by Toray DuPont, Kapton 50EN) is attached on a film base material and subjected to SiO ₂ oxide film treatment ) Having an aluminum wiring pattern (pattern width 21 μm, inter-electrode space 17 μm) was prepared.

For the connection between the IC chip and the film substrate, a thermocompression bonding apparatus comprising a quartz stage (150 mm × 150 mm) made of a ceramic heater, a tool (3 mm × 20 mm), and an LED light source that generates ultraviolet light having a wavelength of 365 nm was used. First, the surface on the side of the conductive adhesive layer of the anisotropic conductive films (2.5 mm × 25 mm) according to Examples 1 to 12 and Comparative Examples 1 to 4 is applied to a glass substrate at 80 ° C. and 0.98 MPa (10 kgf / cm). ^The film was pasted by heating and pressing for 2 seconds under the condition ² ).

Next, after peeling off the release film on the conductive adhesive layer of the anisotropic conductive film and irradiating 300 mJ / cm ² ultraviolet rays from the upper surface of the anisotropic conductive film, the bump electrode of the IC chip and the circuit of the glass substrate The alignment with the electrode was performed. Thereafter, the insulating adhesive layer was attached to the IC chip by heating and pressurizing for 5 seconds under the conditions of an actually measured maximum temperature of 80 ° C. of the anisotropic conductive film and an area conversion pressure of 70 MPa at the bump electrode.

(Evaluation of connection resistance)
In the connection structures obtained by using the anisotropic conductive films of Examples 1 to 12 and Comparative Examples 1 to 4, the resistance value between the bump electrode and the circuit electrode was evaluated. The resistance value was evaluated by a four-terminal measurement method, and an average value of 14 measurements was used. Bad connection was marked with x. Moreover, the resistance value (maximum value among 14 terminals measured) after the high-temperature and high-humidity test in which a load was applied for 500 hours under the conditions of 85 ° C. and 85% RH was also measured. The results are shown in Tables 2-4.

(Measurement of adhesive strength)
The die shear strength test was done about the connection structure produced by the said production method A using the anisotropic conductive film of Examples 1-12 and Comparative Examples 1-4. Bad connection was marked with x. The results are shown in Tables 2-4. The die shear strength was measured using a Dage bond tester Dage-Series-4000 and a load cell DS100.

  As shown in Tables 2 to 4, the anisotropic conductive films obtained in Examples 1 to 12 achieved both low-temperature curability and storage stability, and good adhesive strength and connection reliability were obtained.

  On the other hand, as shown in Comparative Examples 1 and 2, when the epoxy compound or thiol compound was not blended, the first circuit member and the second circuit member could not be connected.

  Moreover, as shown in Comparative Example 3, when the chemical structure of the photobase generator was different, the first circuit member and the second circuit member could not be connected.

  Furthermore, as shown in Comparative Example 4, when an acid generator is used, a connection structure can be produced when ultraviolet irradiation and heating / pressurization are simultaneously performed in the production of the connection structure (production method A). However, the adhesive strength was low, and the resistance value increased after the moisture resistance test. The connection structure produced by heating and pressurizing after ultraviolet irradiation (Production Methods B and C) could not connect the first circuit member and the second circuit member. Furthermore, storage stability deteriorated.

  DESCRIPTION OF SYMBOLS 1 ... Connection structure, 2 ... 1st circuit member, 3 ... 2nd circuit member, 6 ... Bump electrode, 8 ... Circuit electrode, 11, 21 ... Anisotropic conductive film, 12 ... Release film, 13 ... Conductivity Adhesive adhesive layer, 14 ... insulating adhesive layer, P ... conductive particles.

Claims (10)

An anisotropic conductive film interposed between circuit electrodes facing each other and used to pressurize the circuit electrodes and electrically connect the electrodes in the pressurizing direction,
(A) a film forming material;
(B) an epoxy compound or an oxetane compound;
(C) a thiol compound;
(D) a curing agent that generates a base by light;
An adhesive layer containing
(D) The anisotropic conductive film in which the hardening | curing agent which generate | occur | produces a base by light contains the carboxylate shown by following General formula (1).

[In General Formula (1), R represents CH ₃ or H, and X represents a base selected from amidines, guanidines, or phosphazene derivatives. ] The anisotropic conductive film according to claim 1, wherein the amidine is a compound represented by the following formula (2).

The anisotropic conductive film according to claim 1 or 2, wherein the guanidine is a compound represented by the following formula (3-1) or formula (3-2).

The phosphazene derivative is a compound represented by the following formula (4-1), formula (4-2), formula (4-3), or formula (4-4). The anisotropic conductive film as described in the item.

  The anisotropic conductive film according to any one of claims 1 to 4, wherein the (c) thiol compound is a polythiol compound having three or more thiol groups.   The content of the curing agent that generates a base by (d) light in the adhesive layer is 0.5-30 with respect to a total of 100 parts by mass of (b) the epoxy compound or oxetane compound and (c) thiol compound. The anisotropic conductive film as described in any one of Claims 1-5 which is a mass part.   The adhesive layer contains 0.1 to 50 parts by volume of conductive particles with respect to a total of 100 parts by volume of the (a) film-forming material and the (b) epoxy compound or oxetane compound and the (c) thiol compound. The anisotropic conductive film as described in any one of Claims 1-6 to contain.   The hardened | cured material of the anisotropic conductive film as described in any one of Claims 1-7 was provided with the 1st circuit member provided with the bump electrode, and the circuit electrode corresponding to the said bump electrode. A connection structure in which a second circuit member is bonded and the bump electrode and the circuit electrode are electrically connected.   8. The system according to claim 1, wherein a main surface of the first circuit member provided with the bump electrode and a main surface of the second circuit member provided with the circuit electrode corresponding to the bump electrode are disposed. The anisotropic conductive film described in the above is disposed, the anisotropic conductive film is heated and pressurized via the first circuit member and the second circuit member, and further ultraviolet rays are emitted from the back surface of the second circuit member. Irradiating and curing, bonding the first circuit member and the second circuit member through the cured product of the anisotropic conductive film, and electrically connecting the bump electrode and the circuit electrode A method for manufacturing a connection structure.   The anisotropic conductive film according to any one of claims 1 to 7 is disposed on a second circuit member provided with a circuit electrode, and the circuit is irradiated with ultraviolet rays from the anisotropic conductive film. A first circuit member provided with a bump electrode corresponding to an electrode is disposed on the anisotropic conductive film, and the anisotropic conductive film is heated via the first circuit member and the second circuit member. And pressurizing and curing, bonding the first circuit member and the second circuit member through a cured product of the anisotropic conductive film, and electrically connecting the bump electrode and the circuit electrode The manufacturing method of the connection structure which connects.

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