TW202029221A - Adhesive composition - Google Patents

Abstract

The adhesive composition according to the present invention, which is capable of realizing low-temperature quick-curing properties, conductive properties, shelf life properties, and adhesive strength that are practical not only for COG mounting, but also for FOG mounting and FOP mounting, contains a cation-polymerizable component, a cation polymerization initiator, an elastomer, and a film-forming component. The cation-polymerizable component is an alicyclic epoxy compound or a low-polarity oxetane compound, and the cation polymerization initiator is a quaternary ammonium salt thermal acid generator. With respect to the total mass of the cation-polymerizable component, elastomer, and film-forming component, the cation-polymerizable component content is 10-40 mass%, the elastomer content is 10-40 mass%, and the film-forming component content is 40-80 mass%.

Description

Adhesive composition

The present invention relates to an adhesive composition that can be preferably used for anisotropic conductive films.

When using an anisotropic conductive film to mount an IC (Integrated Circuit) chip on a glass substrate (ie, COG (Chip On Glass) mounting), in order to alleviate the thermal shock to the IC chip, To improve the productivity of installation, it is required to use an anisotropic conductive film that exhibits low-temperature rapid curing. Previously, as a polymerization system for this kind of anisotropic conductive film, it was proposed to combine an alicyclic epoxy compound with a low-polarity oxetane compound, which has a higher cationic polymerization reactivity than the commonly used glycidyl ether epoxy compound, and Among the cationically polymerizable components, a quaternary ammonium salt-based thermal acid generator that generates protons by heat is used as a cationic polymerization initiator that does not inhibit polymerization due to oxygen and exhibits dark reactivity (Patent Document 1) . [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-152354

[The problem to be solved by the invention]

However, with regard to the anisotropic conductive film disclosed in Patent Document 1, in the case of COG mounting, good adhesion strength, practical storage life characteristics, and good conduction characteristics are achieved. However, when the flexible circuit board (FPC ) When it is installed on a glass substrate or a plastic substrate (FOG (Film On Glass) installation or FOP (Film On Plastic) installation), due to the bending or tensile stress, shearing and shearing applied to the FPC after installation Shear stress, peeling stress, etc., not only the inability to obtain practical bonding strength, but also the reduction of conduction characteristics such as on-resistance value or the reduction of storage life characteristics. In addition, for anisotropic conductive films, it is also required to suppress or omit the use of expensive low-polar oxetane compounds.

The subject of the present invention relates to a cationic polymerizable adhesive composition using cationic polymerizable components such as alicyclic epoxy compounds and a quaternary ammonium salt-based thermal acid generator, especially an anisotropic conductive adhesive. In COG installation, but also in FOG installation or FOP installation, it can also achieve practical low-temperature rapid hardening, conduction characteristics, storage life characteristics, and adhesive strength. [Technical means to solve the problem]

The inventors discovered that an adhesive composition containing cationic polymerizable components represented by alicyclic epoxy compounds, a quaternary ammonium salt-based thermal acid generator as a cationic polymerization initiator, and film-forming components In this method, an elastomer is formulated, and the contents of the cationically polymerizable component, the elastomer, and the film-forming component are adjusted to specific ranges, respectively, to solve the problem of the present invention and complete the present invention.

That is, the present invention provides an adhesive composition containing a cationic polymerizable component, a cationic polymerization initiator, an elastomer, and a film-forming component, and The cationic polymerizable component is an alicyclic epoxy compound or a low polar oxetane compound, The cationic polymerization initiator is a quaternary ammonium salt series thermal acid generator, The content of the cationic polymerizable component is 10-40% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components, The content of the elastomer is 10-40% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components, and The content of the film-forming components is 40 to 80% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components.

In addition, the adhesive composition of the present invention, regardless of whether it contains conductive particles, can be used to combine first electronic parts such as FPC, IC chip, IC module, and second electronic parts such as plastic substrates, glass substrates, rigid substrates, ceramic substrates, and FPCs. It can be applied when making connections, preferably when making electrical connections (especially when making anisotropic conductive connections). In particular, it can be preferably used in a connection structure using FPC, and can be more preferably used in a connection structure using FPC for the first electronic component. Therefore, the present invention also provides a connection structure for connecting a first electronic component and a second electronic component, preferably an electrical connection (preferably anisotropic conductive connection) using the above-mentioned adhesive composition, and its manufacture method. [Effects of Invention]

In the adhesive composition of the present invention, among cationically polymerizable components represented by alicyclic epoxy compounds, quaternary ammonium salt-based thermal acid generators as cationic polymerization initiators, and film-forming components, Furthermore, the elastomer is formulated, and the contents of the cationically polymerizable component, the elastomer, and the film-forming component are adjusted to specific ranges, respectively. Therefore, when the adhesive composition of the present invention contains conductive particles for anisotropic conductive connection, it can ensure the same low-temperature rapid curing properties, conduction characteristics, and storage life characteristics as before, and can be installed in FOG or FOP It can also achieve practical bonding strength.

Hereinafter, an example of the present invention will be described in detail.

＜Adhesive composition＞ The adhesive composition of the present invention contains a cationic polymerizable component, a cationic polymerization initiator, an elastomer, and a film-forming component. Hereinafter, these components are explained in detail. Furthermore, the adhesive composition of the present invention can take various forms such as a liquid adhesive, a paste adhesive, a film adhesive, and a granular adhesive. Among them, an anisotropic conductive film can be exemplified as a preferable film-like adhesive.

(Cationically polymerizable component) The cationically polymerizable component is a component that hardens the adhesive composition, and contains at least any one of alicyclic epoxy compounds or low-polarity oxetane compounds with higher reactivity than commonly used glycidyl ether epoxy compounds As an epoxy compound. These can also be used in combination. It is preferable to use only an alicyclic epoxy compound as a cationically polymerizable component.

Regarding the content of the cationic polymerizable component, in order to achieve good low-temperature quick-curing properties, the total mass of the cationic polymerizable component, elastomer, and film-forming component should be 10% by mass or more, preferably 15% by mass or more. The content of the elastomer is relatively maintained at a certain level or more to achieve good adhesion, and is 40% by mass or less of the total mass of the cationic polymerizable component, elastomer, and film-forming component, preferably 35% by mass or less.

(Alicyclic epoxy compound) The reason for using the alicyclic epoxy compound is to use its higher reactivity than the commonly used glycidyl ether type epoxy compound to give the anisotropic conductive film good low-temperature rapid curing properties. As such an alicyclic epoxy compound, those which have 2 or more epoxy groups in a molecule|numerator are mentioned suitably. These may be liquid or solid. Specifically, examples include: diglycidyl hexahydrobisphenol A, 3',4'-epoxycyclohexenecarboxylic acid 3,4-epoxycyclohexenyl methyl ester, and diepoxybicyclohexane Wait. Among them, diglycidyl hexahydrobisphenol A, especially diepoxybicyclohexane can be preferably used in terms of ensuring the light transmittance of the cured product and the excellent quick curing properties.

(Low polar oxetane compound) In the present invention, a low-polarity oxetane compound may be used in place of the alicyclic epoxy compound or together with the alicyclic epoxy compound. The low-polarity oxetane compound is an oxetane compound with a dipole moment of 3.0 d or less. The surface tension is relatively low, and it can impart good leveling properties to the anisotropic conductive film, resulting in improved anisotropy The storage life of the heterogeneous conductive film. Furthermore, when using a low-polarity oxetane compound as a cationic polymerizable component, compared with the case of using an alicyclic epoxy compound, there is an anisotropic conductive film using a differential scanning calorimeter (DSC) The measured tendency of the reaction starting temperature to rise, but it is also the range of practical low-temperature rapid hardening. Examples of such low-polarity oxetane compounds include 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxy Etidine, bis[1-ethyl(3-oxetanyl)] methyl ether, 4,4'-bis[(3-ethyl-3-oxetanyl) methoxymethyl ] Biphenyl etc. Among them, in terms of low surface tension and excellent wettability, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane is preferred, and 4,4 is particularly preferred. '-Bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl.

As a cationically polymerizable component, when an alicyclic epoxy compound and a low-polarity oxetane compound are used in combination, the mixing ratio of these (alicyclic epoxy compound: low-polarity oxetane compound) On a quality basis, it is preferably 25:75 to 60:40, more preferably 45:55 to 60:40, and particularly preferably 50:50 to 55:45. If the blending amount of the low-polarity oxetane compound is increased from this range, the reaction initiation temperature tends to rise, and if it is decreased, the storage life tends to decrease. Therefore, by adjusting the mixing ratio of the alicyclic epoxy compound and the low-polarity oxetane compound, the reaction start temperature of the anisotropic conductive film can be controlled, and the reaction end temperature can be controlled, and furthermore, it can also be adjusted by The reaction time is controlled by the rate of temperature increase during the reaction.

(Cationic polymerization initiator) The adhesive composition of the present invention contains a quaternary ammonium salt-based thermal acid generator instead of a sulfonate-based thermal acid generator as a cationic polymerization initiator. The reason is that the storage life can be increased. Here, the "storage life" refers to the period during which the adhesive composition is stored without any practical problems in its properties. Examples of such quaternary ammonium salt-based thermal acid generators include: quaternary ammonium cation, hexafluoroantimonate anion, hexafluorophosphate anion, trifluoromethanesulfonic acid anion, perfluorobutanesulfonic acid anion, dinonyl Naphthalenesulfonic acid anion, p-toluenesulfonic acid anion, dodecylbenzenesulfonic acid anion, or salt of tetrakis (pentafluorophenyl) borate anion, etc. Moreover, as a quaternary ammonium cation, the cation represented by [NR ₁ R ₂ R ₃ R ₄ ] ⁺ can be mentioned. Here, R ₁ , R ₂ , R ₃ and R ₄ are linear, branched or cyclic alkyl or aryl groups having 1 to 12 carbons, and may have hydroxyl, halogen, alkoxy, or amino groups, respectively. , Ester group, etc.

Specific examples of quaternary ammonium salt-based thermal acid generators include: CXC-1612, CXC-1733, CXC-1738, TAG-2678, CXC-1614, TAG-2689, TAG- manufactured by King Industries, Inc. 2690, TAG-2700, CXC-1802-60, CXC-1821, etc. These can be obtained from Nanben Chemical Co., Ltd.

Regarding the content of the cationic polymerization initiator, in order to achieve good low-temperature quick-curing properties, relative to 100 parts by mass of the cationic polymerizable component, it is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, and in order to suppress storage life The reduction in the reduction or the deterioration of the migration (corrosion) of the terminal or the electrode is preferably 20 parts by mass or less, more preferably 10 parts by mass or less.

(Elastomer) In order to achieve good adhesive strength, the adhesive composition of the present invention contains an elastomer. Here, the so-called elastomer refers to a polymer that exhibits rubber elasticity at room temperature. Specifically, it is a polymer exhibiting a Young's modulus of 1-40 Mpa at 20-70°C, and may also be thermosetting, usually thermoplastic. In addition, the elastomer applicable to the present invention has a glass transition temperature (Tg) of preferably -100 to 0°C, and a weight average molecular weight of preferably 20,000 to 2,000,000.

Examples of such elastomers include: natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-butadiene rubber Ene-styrene rubber (SBS), styrene-ethylene-butene-styrene rubber (SEBS), styrene-isoprene-styrene rubber (SIS), chloroprene rubber (CR), acrylonitrile Butadiene rubber (NBR), acrylic rubber (ACM), etc. It is preferable to select one that shows good compatibility with the polymer of the cationic polymerizable component from these. Since the cationically polymerizable component contains at least either an alicyclic epoxy compound or a low-polarity oxetane compound, it can be preferably used for acrylic rubbers with ester bonds in the polymer chain.

The acrylic rubber may have various functional groups such as a hydroxyl group, a carboxyl group, an amide group, and an epoxy group. Among them, an acrylic rubber having a hydroxyl group as a functional group expected to further increase the affinity for the polymer of the cationically polymerizable component in the present invention can be preferably used. For example, copolymers of hydroxyethyl acrylate and the like with ethyl acrylate, hydroxybutyl acrylate, methoxyethyl acrylate, etc. can be cited.

Regarding the content of the elastomer, in order to impart good adhesiveness to the adhesive composition, it is 10% by mass or more of the total mass of the cationic polymerizable component, elastomer, and film-forming component, preferably 20% by mass or more. The content of the cationic polymerization component is relatively maintained at a certain level or more to achieve good adhesion, and is 40% by mass or less, preferably 30% by mass or less of the total mass of the cationic polymerizable component, elastomer, and film-forming component.

(Ingredients for film formation) The film-forming component is a component for filming (filming) the adhesive composition, and is a component having film-forming ability. Examples of such film-forming components include phenoxy resins, unsaturated polyester resins, saturated polyester resins, urethane resins, butadiene resins, polyimide resins, polyamide resins, Polyolefin resin etc. can also use together 2 or more types of these. Among these, phenoxy resins can be preferably used from the viewpoints of film forming properties, processability, and connection reliability.

Regarding the content of the film-forming components, in order to provide good film-forming properties to the adhesive composition, it is 40% by mass or more of the total mass of the cationic polymerizable component, elastomer, and film-forming components, preferably 50% by mass Above, in order to keep the content of the elastomer relatively constant to achieve good adhesiveness, the total mass of the cationic polymerizable component, elastomer, and film-forming component should be 80% by mass or less, preferably 70% by mass the following.

(Conductive particles) In order to achieve conductive connection, preferably anisotropic conductive connection, the adhesive composition of the present invention preferably contains conductive particles. As the conductive particles, it is possible to appropriately select and use from users of previously known conductive films or conductive pastes, or anisotropic conductive films or anisotropic conductive pastes. Examples include metal particles such as nickel, cobalt, silver, copper, gold, and palladium, alloy particles such as solder, and metal-coated resin particles. Two or more types can also be used in combination.

As the state of existence of the conductive particles in the adhesive composition of the present invention, there can be mentioned: when the composition is formed into a film, the state is randomly dispersed in the composition in a plan view, and the composition is conductive The state where the particles are separated from each other, the state where the conductive particles are regularly arranged in the composition film, etc. (refer to Japanese Patent Laid-Open 2016-066573, Japanese Patent Laid-Open 2016-103476, etc.).

The average particle diameter of the conductive particles is not particularly limited, and may be appropriately selected according to the purpose. As an example, it may be 1 μm or more and 30 μm or less. In order to cope with the difference in wiring height, and to suppress the increase of on-resistance and the generation of short circuit, it is preferably 2.5 μm or more and 30 μm or less, and more preferably 3 μm or more and 9 μm or less. The particle size of the conductive particles can be measured by a normal particle size distribution measuring device, and the average particle size can also be determined using a particle size distribution measuring device. As an example, an image-type particle size distribution measuring device FPIA-3000 (manufactured by Malvern Panalytical) can be cited.

Furthermore, when the conductive particles are metal-coated resin particles, in order to obtain good connection reliability, the particle hardness (20% K value, compression elastic deformation characteristic K ₂₀ ) of the resin core particles is preferably 100 to 1000 kgf/ mm ² , more preferably 200～500 kgf/mm ² . The compression elastic deformation characteristic K ₂₀ can be measured at a measurement temperature of 20° C. using, for example, a micro compression tester (MCT-W201, manufactured by Shimadzu Corporation).

The amount of conductive particles in the adhesive composition of the present invention can be considered based on the connection layout of the width or area of the terminal to be connected to isotropic or anisotropic conductive connection, and the distance between the terminals to suppress the reduction of the capturing efficiency of conductive particles. , And decided to suppress the occurrence of short circuit. When applied to anisotropic conductive connection, it is preferably 50 or more and 100,000 or less, and more preferably 200 or more and 70,000 or less per 1 square mm. The measurement of the abundance can be performed by observing a thin film of the material using an optical microscope such as a known metal microscope or an electron microscope. The thickness of the film can be measured in the form of the thickness used for connection (it can be measured with a commercially available digital thickness gauge, etc.). Furthermore, before the anisotropic conductive connection, it may be difficult to observe the conductive particles in the adhesive composition with an optical microscope or the like. In this case, the adhesive composition after anisotropic conductive connection can also be observed. In this case, the amount can be calculated by considering the change in the thickness of the adhesive composition before and after the connection.

Furthermore, the amount of conductive particles present in the adhesive composition can also be expressed on a mass basis. When applied to the case of anisotropic conductive connection, its amount is when the total mass of the adhesive composition is set to 100 parts by mass, and it is preferably 1 part by mass or more and 30 parts by mass in 100 parts by mass. Hereafter, it is more preferable to be 3 mass parts or more and 10 mass parts or less.

(Other ingredients) The adhesive composition of the present invention may optionally contain other curable resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, and these modified epoxy resins. Oxygen resins, silane coupling agents, fillers, softeners, accelerators, anti-aging agents, colorants (pigments, dyes), organic solvents, ion traps, etc. Furthermore, if necessary, a (meth)acrylate compound and a radical polymerization initiator may be contained. Here, as the (meth)acrylate compound, a previously known (meth)acrylate monomer can be used. For example, a monofunctional (meth)acrylate-based monomer and a multifunctional (meth)acrylate-based monomer with more than difunctionality can be used. Here, (meth)acrylate includes acrylate and methacrylate. Moreover, as a radical polymerization initiator, a well-known radical polymerization initiator, such as organic peroxide and azobisisobutyronitrile, can be contained.

(Preparation of Adhesive Composition) In the adhesive composition of the present invention, the above-mentioned cationic polymerizable component, cationic polymerization initiator, elastomer, and film-forming components (conductive particles and other components as necessary) can be used to make the content of the cationic polymerizable component , The content of the elastomer and the content of the film-forming components are respectively 10-40% by mass, 10-40% by mass, and 40-80% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components The blending amount can be prepared by uniformly mixing with toluene and other solvents as needed.

Furthermore, when the adhesive composition is used as an anisotropic conductive film, it can be produced by filming the adhesive composition (coating) prepared containing conductive particles and a solvent using a known filming method. .

Furthermore, such an anisotropic conductive film may be a single layer, or an insulating resin layer containing no conductive particles may be laminated. As such an insulating resin layer, it is preferable to have a lower minimum melt viscosity and relatively lower fluidity than a layer containing conductive particles. Regarding the lowest melt viscosity ratio, the conductive particle-containing layer is preferably 2 times or more of the insulating resin layer, more preferably 5 times or more, and still more preferably 8 times or more. If the layer containing conductive particles has a relatively high viscosity, the flow of conductive particles that are not needed during connection can be suppressed, the trapping performance can be improved, and short circuits can be suppressed. Regarding the minimum melt viscosity, as an example, a rotary rheometer (manufactured by TA Instruments) can be used to determine the measurement pressure with a fixed pressure of 5 g and a measurement plate with a diameter of 8 mm. More specifically, it can be obtained by Since the temperature range is 30 to 200°C, the temperature rise rate is 10°C/min, the measurement frequency is 10 Hz, and the load variation of the measurement plate is 5 g. In this case, the anisotropic conductive film has a two-layer structure of a conductive particle-containing layer and an insulating resin layer. It can also be set to 3 or more layers as needed. Such an insulating resin layer can be formed of a composition that is basically the same as the adhesive composition of the present invention.

When the adhesive composition of the present invention is an anisotropic conductive film, the layer thickness can be appropriately set according to the purpose of use, etc., and is preferably 3-50 μm thick, more preferably 5-20 μm thick. Whether it is a single layer containing only a layer containing conductive particles or a layer containing conductive particles and an insulating resin are laminated, it refers to the overall thickness. The thickness ratio of the conductive particle-containing layer and the insulating resin layer can be appropriately set according to the purpose of use.

＜Connected structure＞ Regardless of whether the adhesive composition of the present invention contains conductive particles, it can be used to connect the first electronic component and the second electronic component, preferably when performing electrical connection (especially when performing anisotropic conductive connection). The first electronic part and the second electronic part can be the same kind of electronic parts, or they can be different from each other. As the second electronic part, it is better to choose the same or higher rigidity as the first electronic part Components. In addition, when the first electronic part and the second electronic part are clamped between the crimping tool and the pressure plate for connection, when the first electronic part is arranged on the side of the crimping tool, it is preferable as the second electronic part To select electronic parts with a horizontal surface that can be easily placed on the platen. Examples of the first electronic component include FPC, IC chip, IC module, etc., and examples of the second electronic component include plastic substrates, glass substrates, rigid substrates, ceramic substrates, FPC, and the like. In the case of anisotropic conductive connection, as the first electronic component, FPC can be preferably selected, and the first electronic component can be selected as FPC and the second electronic component is a relatively rigid plastic substrate or glass. In the case of substrates, hard substrates, and ceramic substrates. It is more preferable to select a plastic substrate or a glass substrate (that is, FOP or FOG) that has rigidity as the substrate itself of the second electronic component and can undergo shape deformation (a small amount of warpage is likely to be a problem) as described above. The situation). The reason is that the adhesive composition of the present invention can be constituted by a formulation that can maintain the bent state of the first electronic component after anisotropic conductive connection. Furthermore, using the adhesive composition of the present invention, regardless of whether it contains conductive particles, the first electronic component and the second electronic component are connected, preferably a connection structure for electrical connection, and the first electronic component is connected to the The manufacturing method of the connection structure in which the second electronic component is connected, preferably electrically connected, is also a part of the present invention. Especially when the adhesive composition of the present invention containing conductive particles is used as an anisotropic conductive adhesive (preferably an anisotropic conductive film), in the present invention, such an anisotropic conductive adhesive is used to The manufacturing method of the connecting structure in which the first electronic component and the second electronic component are anisotropically conductively connected, and the connecting structure in which the first electronic component and the second electronic component are anisotropically conductively connected are also part of the present invention. Furthermore, as a method of connecting electronic parts using the adhesive composition of the present invention, a known method can be used. [Example]

Hereinafter, the present invention will be explained in more detail with examples.

Examples 1-11, Comparative Examples 1-7 According to the formulation in Table 1, diepoxybicyclohexane (Celloxide 8000, Daicel (stock)) as alicyclic epoxy compound, 4,4'-bis[( 3-Ethyl-3-oxetanyl)methoxymethyl]biphenyl (OXBP, Ube Industries Co., Ltd.), hydroxyl-containing acrylic rubber as an elastomer (SG-80H, Nagase chemteX ( Stock)), thermal cationic polymerization initiator (quaternary ammonium salt-based thermal acid generator, trade name CXC-1612, Kusumoto Chemical (stock)), phenoxy resin (YP-50, Nippon Steel Chemical & Materials (stock) )), and conductive particles (Ni/Au-plated resin particles, AUL704, Sekisui Chemical Co., Ltd.) with an average particle size of 4 μm were added to toluene so that the solid content became 50% by mass to prepare an adhesive composition.

The obtained adhesive composition was applied to a polyethylene terephthalate release film (PET release film) with a thickness of 50 μm so that the dry thickness became 6 μm, and dried in an oven at 60°C for 5 minutes , Thereby forming a single-layer anisotropic conductive film.

Examples 12-14 In order to evaluate the adhesive composition without conductive particles, the conductive particles were removed from the adhesive compositions prepared in Examples 1, 3, and 5, except that the same operations as in Example 1 were repeated to produce Insulating adhesive film.

＜＜Evaluation 1＞＞ Using the anisotropic conductive films obtained in each of Examples 1 to 11 and Comparative Examples 1 to 7, a connection structure was produced as described below, and "adhesive strength", "DSC reaction start temperature", and "Storage "Life", "Initial on-resistance" and "On-resistance after reliability test" are tested or measured and evaluated respectively.

＜Production of connection structure＞ The test FPC (printed circuit with electrodes (8 μm thick Cu/Sn plating) formed on one side of 38 μm thick polyimide at 200 μm pitch (L/S=100 μm/100 μm)), and single A 0.5 mm thick test glass substrate with an indium titanium oxide film (10 Ω/□) on the surface, and an anisotropic conductive film made in the example or the comparative example with the release film removed therebetween (2.0 mm×50.0 mm short strip shape), anisotropic conductive connection is performed under the conditions of 130°C, 3 MPa, 5 seconds (tool width: 2.0 mm) to obtain a connection structure.

＜Adhesion strength＞ Fix the glass substrate of the above-obtained connection structure on a tensile testing machine (RTC1225A, A&D (share)), and set the test FPC (cut to a length of 1 cm) at room temperature (25°C) 50 mm/sec. The speed is pulled in the direction of 90 degrees, and the force required for peeling is set as the adhesive strength (N), and the evaluation is performed according to the following criteria. The results obtained are shown in Table 1.

(Adhesive strength evaluation criteria) A (very good): The bonding strength is 10 N or more B (Good): Adhesion strength is 5 N or more and less than 10 N C (Poor): Adhesion strength does not reach 5 N

＜DSC reaction starting temperature＞ The 5 mg sample cut from the anisotropic conductive film was stored in aluminum PAN (TA Instruments Inc.), and placed in a DSC measuring device (Q2000, TA Instruments Inc.) at a temperature increase rate of 10℃/min. A differential scanning calorimeter measurement was performed at 30°C to 250°C, and the rising temperature of the heat dissipation peak was read from the obtained DSC chart as the reaction starting temperature. The results obtained are shown in Table 1. The lower the reaction initiation temperature, the better the low-temperature rapid hardening property. In terms of practicality, it is desirable that the reaction initiation temperature is 100°C or lower.

＜Storage life characteristics＞ As described below, test evaluations of storage life 1 to 3 are performed. For storage life 1, it is expected that it is 10 days or more, for storage life 2, it is expected that it is 7 days or more, and for storage life 3, it is expected that it is 7 days or more. Practically, as long as it satisfies at least one of storage life 1 to 3, it is preferable to satisfy both, and it is more preferable to satisfy all. Furthermore, from the viewpoint of evaluation of the storage life of the adhesive composition, it is desirable to satisfy storage life 1 (DSC peak).

＜Storage life 1＞ The anisotropic conductive film with the PET peeling film substrate was put into a constant temperature and humidity chamber set at a humidity of 40% and a temperature of 25°C or 30°C, and samples were taken every 24 hours after being put in. For the sampled anisotropic conductive film, make a sample under the above-mentioned connection structure manufacturing conditions and perform DSC measurement, and calculate the number of days that the peak intensity is maintained at a constant temperature and humidity room for more than 70% before being put into use, and the number of days that will be maintained Set the storage life.

＜Storage life 2＞ Regarding the anisotropic conductive film sampled in the same manner as in the storage life 1, the on-resistance value was measured as described below, and the number of days to maintain less than 5 Ω was calculated, and the number of days that could be maintained was the storage life.

＜Storage life 3＞ With respect to the anisotropic conductive film sampled in the same manner as in the storage life 1, the adhesive strength was measured as described above, and the number of days to maintain 5 N or more was calculated, and the number of days that could be maintained was the storage life.

＜Initial on-resistance, on-resistance after reliability test＞ Use a digital multimeter (digital multimeter 7555, Yokogawa Measurement Co., Ltd.) to measure the on-resistance value (initial on-resistance value) of the connecting structure immediately after fabrication and 85°C using the four-terminal method (when 1 mA is energized).・The on-resistance value after the damp heat test of 85%RH for 500 hours (the on-resistance value after the reliability test) is evaluated according to the following evaluation criteria. The results obtained are shown in Table 1.

(Initial on-resistance and on-resistance evaluation criteria after reliability test) OK (good): The initial on-resistance value does not reach 2 Ω, and the on-resistance value after the reliability test does not reach 5 Ω NG (bad): The initial on-resistance value is 2 Ω or more, and the on-resistance value after the reliability test is 5 Ω or more

[Table 1] Ingredient name (parts by mass) Comparative example Example Comparative example Example Comparative example Example Comparative example Example Comparative example 1 1 2 3 4 5 2 6 3 4 7 8 9 (4) (1) 5 6 (4) (2) 10 (6) 11 7 Alicyclic epoxy compound (a) 5 10 20 25 30 40 50 0 10 25 10 30 25 30 10 10 30 30 20 10 0 10 5 Low-polarity oxetane compounds (b) 0 0 0 0 0 0 0 20 20 0 0 0 0 0 0 0 0 0 0 20 20 0 0 Elastomer (c) 25 40 30 25 30 10 10 10 0 5 10 20 25 30 40 50 40 30 30 10 10 10 5 Phenoxy resin (d) 70 50 50 50 40 50 40 70 70 70 80 50 50 40 50 40 30 40 50 60 70 80 90 Quaternary ammonium salt series thermal acid generator (e) 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Conductive particles (f) 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 (a＋b)×100/(a＋b＋c＋d)[mass%] 5 10 20 25 30 40 50 20 30 25 10 30 25 30 10 10 30 30 20 30 20 10 5 c×100/(a＋b＋c＋d)[mass%] 25 40 30 25 30 10 10 10 0 5 10 20 25 30 40 50 40 30 30 10 10 10 5 d×100/(a＋b＋c＋d)[mass%] 70 50 50 50 40 50 40 70 70 70 80 50 50 40 50 40 30 40 50 60 70 80 90 ＜Evaluation result＞ Then strength evaluation B B A A A B B B C B A A A A B B B A A A B A B DSC reaction starting temperature (℃) 83 80 77 75 73 70 69 100 80 75 80 73 75 73 80 80 73 73 77 80 100 80 83 Storage life 1 (day) 20 15 13 13 13 10 7 20 15 15 15 13 13 13 15 15 13 13 13 15 20 15 20 Storage life 2 (days) 20 15 13 13 13 10 7 20 15 15 15 13 13 13 15 15 13 13 13 15 20 15 20 Storage life 3 (days) ＞20 ＞15 ＞13 ＞13 ＞13 ＞10 ＞7 ＞20 ＞15 ＞15 ＞15 ＞13 ＞13 ＞13 ＞15 ＞15 ＞13 ＞13 ＞13 ＞15 ＞20 ＞15 ＞20 Evaluation of initial on-resistance NG OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK NG On-resistance evaluation after reliability test NG OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK NG

＜＜Discussion of Evaluation Results 1＞＞ From the results of Comparative Example 1, Examples 1 to 5 and Comparative Example 2 in Table 1, it can be seen that the preferred blending amount of the alicyclic epoxy compound or the low polar oxetane compound as the cationic polymerizable component is cationic polymerization 10-40% by mass of the total mass of the sexual components, elastomers, and phenoxy resin used as film-forming components. Also, from the results of Comparative Examples 3, 4, Examples 1, 4, 7-9, and Comparative Example 5, it can be seen that the preferred blending amounts of elastomers are cationically polymerizable components, elastomers, and benzene as film-forming components. 10-40% by mass of the total mass of oxy resin. Furthermore, from the results of Comparative Example 6, Examples 2, 4, 6, 10, 11, and Comparative Example 7, it can be seen that the contents of the film-forming components are cationically polymerizable components, elastomers, and phenoxy as the film-forming components. 40~80% by mass of the total mass of the base resin.

＜＜Evaluation 2＞＞ Using the adhesive films obtained in Examples 12 to 14 without conductive particles, a connection structure was produced under the same conditions as in <<Evaluation 1>>, and the "adhesion strength" was measured and evaluated. As a result, Example 12 was used The adhesive strength of the connection structure produced by the adhesive film of and 14 was 5 N or more (B evaluation), and the adhesive strength of the connection structure produced using the adhesive film of Example 13 was 10 N or more (A evaluation). All are practically problem-free adhesive strength. [Industrial availability]

The adhesive composition of the present invention is not only used in COG installation, but also in FOG installation or FOP installation, and can also achieve practical low-temperature quick-curing properties, conduction characteristics, storage life characteristics, and adhesive strength, and is therefore industrially useful.

Claims (11)

An adhesive composition containing a cationic polymerizable component, a cationic polymerization initiator, an elastomer, and a film-forming component, and The cationic polymerizable component is an alicyclic epoxy compound or a low polar oxetane compound, The cationic polymerization initiator is a quaternary ammonium salt series thermal acid generator, The content of the cationic polymerizable component is 10-40% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components, The content of the elastomer is 10-40% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components, and The content of the film-forming components is 40 to 80% by mass of the total mass of the cationic polymerizable component, elastomer, and film-forming components. The adhesive composition of claim 1, wherein the cationically polymerizable component contains diglycidyl hexahydrobisphenol A or diepoxybicyclohexane as the alicyclic epoxy compound. The adhesive composition of claim 1, wherein the cationically polymerizable component contains 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane or 4,4'-bis[(3- Ethyl-3-oxetanyl)methoxymethyl]biphenyl is used as a low-polarity oxetane compound. The adhesive composition according to any one of claims 1 to 3, wherein the quaternary ammonium salt-based thermal acid generator is a quaternary ammonium cation, a hexafluoroantimonate anion, a hexafluorophosphate anion, and a trifluoromethanesulfonic acid anion , Perfluorobutanesulfonic acid anion, dinonylnaphthalenesulfonic acid anion, p-toluenesulfonic acid anion, dodecylbenzenesulfonic acid anion, or tetrakis (pentafluorophenyl) borate anion. The adhesive composition of claim 4, wherein the quaternary ammonium cation is a cation represented by [NR ₁ R ₂ R ₃ R ₄ ] ⁺ , and R ₁ , R ₂ , R ₃ and R ₄ are linear, branched or A cyclic alkyl or aryl group with 1 to 12 carbon atoms. The adhesive composition according to any one of claims 1 to 5, wherein the elastomer is acrylic rubber and the film-forming component is phenoxy resin. The adhesive composition according to any one of claims 1 to 6, which further contains conductive particles. A connection structure which uses the adhesive composition according to any one of claims 1 to 7 to connect a first electronic component and a second electronic component. A method of manufacturing a connection structure, which uses the adhesive composition according to any one of claims 1 to 7 to connect a first electronic component and a second electronic component. A connection structure which uses the adhesive composition of claim 7 which functions as an anisotropic conductive adhesive to connect a first electronic component and a second electronic component anisotropically. A method of manufacturing a connection structure, which uses the adhesive composition of claim 7 that functions as an anisotropic conductive adhesive to connect a first electronic component and a second electronic component anisotropically.