WO2017014414A1 - Composition for anisotropic conductive film, anisotropic conductive film, and display device using same - Google Patents

Abstract

An embodiment of the present invention relates to a composition for an anisotropic conductive film, the composition containing: a copolymerized compound of a fluorene-based compound and a bisphenol type epoxy compound; an epoxy resin having an epoxy equivalent of 150 g/eq or less; a curing agent; and conductive particles. Another embodiment of the present invention relates to an anisotropic conductive film comprising: a copolymerized compound of a fluorene-based compound and a bisphenol type epoxy compound; and conductive particles, wherein the film has a particle capturing rate, according to equation 1, of 30% or more and an adhesive strength of 10 MPa or more, which are measured after the film is preliminarily compressed in conditions of 1.0-3.0 Mpa at 50-80℃ for 1-3 seconds and mainly compressed in conditions of 60-80 Mpa at 120-160℃ for 3-6 seconds. [Equation 1] Particle capturing rate (%) = (number of conductive particles per unit area (mm²) in a contact site after preliminary compression and main compression) / (number of conductive particles per unit area (mm²) of anisotropic conductive film before preliminary compression) × 100

Description

Composition for anisotropic conductive film, anisotropic conductive film and display device using same

The present invention relates to a composition for an anisotropic conductive film, an anisotropic conductive film and a display device using the same.

Anisotropic conductive film (ACF) generally refers to a film-like adhesive in which conductive particles are dispersed in a resin such as epoxy. The film is electrically conductive in the film thickness direction and insulated in the plane direction. It means a polymer film having anisotropy and adhesion. After placing the film between the circuits to which the anisotropic conductive film is to be connected and subjecting to heating and pressing under a certain condition, the circuit terminals are electrically connected by conductive particles, and an insulating adhesive resin is provided between adjacent electrodes. By filling, the conductive particles are present independently of each other to impart high insulation.

Recently, as thinning and high resolution of display panels have progressed, techniques for capturing the maximum number of conductive particles in the minimum connection area have been studied. In order to improve the capture rate of the conductive particles, a method of increasing the density of the conductive particles or suppressing the flow of the fluid has been studied, which causes deterioration of the insulation resistance between adjacent electrodes or deterioration in adhesion due to an increase in modulus after curing. There was this.

Accordingly, there is a need to develop an anisotropic conductive film that is excellent in insulation resistance and has a low risk of short circuit between electrodes while effectively suppressing the flow of a fluid.

The present invention is to provide an anisotropic conductive film capable of low-temperature rapid curing, but excellent in particle capture rate, adhesion and connection resistance properties.

In one embodiment of the present invention, a copolymer compound of a fluorene-based compound and a bisphenol-type epoxy compound; Epoxy resins having an epoxy equivalent weight of 150 g / eq or less; Curing agent; And the composition for anisotropic conductive films containing electroconductive particle is provided.

In another embodiment of the present invention, an anisotropic conductive film comprising a copolymer of a fluorene-based compound and a bisphenol-type epoxy compound, and conductive particles, the film is 50 ℃ to 80 ℃, for 1 to 3 seconds and 1.0 MPa to 3.0 Pressurized under the conditions of MPa, and after the main compression under 120 ° C to 160 ° C for 3 to 6 seconds and under the pressure conditions of 60 MPa to 80 MPa, the particle capture rate according to the following formula 1 is 30% or more, the adhesive force is 10 MPa or more, An anisotropic conductive film is provided.

[Equation 1]

Particle capture rate (%) = (number of conductive particles per unit area (mm ² ) of the connection site after pressing and main compression / number of (mm ² ) conductive particles per unit area of the anisotropic conductive film before pressing) × 100

In another embodiment of the present invention, a first connected member containing a first electrode; A second to-be-connected member containing a second electrode; And a display device connected by the anisotropic conductive film described herein, which is located between the first to-be-connected member and the second to-be-connected member to connect the first electrode and the second electrode.

Composition for anisotropic conductive film or anisotropic conductive film according to an embodiment of the present invention, the flowability is controlled at a high temperature to improve the capture rate of the conductive particles, low temperature fast curing is possible, adhesion, connection resistance and reliability This has an excellent advantage.

1 shows a first to-be-connected member 50 including a first electrode 70, a second to-be-connected member 60 including a second electrode 80, and the first to-be-connected member and the first to-be-connected member. A display apparatus according to an embodiment of the present invention, comprising an anisotropic conductive film 10 including conductive particles 3 positioned between two connected members to connect the first electrode and the second electrode. 30) is a cross-sectional view.

Hereinafter, the present invention will be described in more detail. Content not described herein is omitted because it can be sufficiently recognized and inferred by those skilled in the art or similar fields of the present invention.

One embodiment of the present invention, a copolymer of a fluorene-based compound and a bisphenol-type epoxy compound; Epoxy resins having an epoxy equivalent weight of 150 g / eq or less; Curing agent; And it relates to the composition for anisotropic conductive films containing electroconductive particle.

The composition for an anisotropic conductive film according to an embodiment of the present invention may include a copolymer of a fluorene-based compound and a bisphenol-type epoxy compound as a binder resin.

The fluorene-based compound includes a fluorene structure and may include two or more hydroxyl groups for copolymerization with a bisphenol type epoxy compound.

In one embodiment, the fluorene-based compound may be a compound having a structure of formula (1).

[Formula 1]

In Formula 1, each R is independently an alkyl group, an alkoxy group, an aryl group, or a cycloalkyl group, m is each independently an integer of 0 to 4, n is each independently an integer of 1 to 5.

The copolymer compound may include the unit derived from the fluorene-based compound, thereby improving heat resistance of the anisotropic conductive film.

The bisphenol-type epoxy compound is not particularly limited, and for example, a bisphenol A-type epoxy compound, a bisphenol F-type epoxy compound, a bisphenol AD-type epoxy compound, a bisphenol E-type epoxy compound, a bisphenol S-type epoxy compound, or a combination thereof may be used. have. In one example, a bisphenol A epoxy compound or a bisphenol F epoxy compound can be used.

The method of copolymerizing the fluorene-based compound and the bisphenol-type epoxy compound to form a copolymerization compound is not particularly limited, and includes, but is not limited to, dissolving the fluorene-based compound and the bisphenol-type epoxy compound in a suitable solvent and a polymerization catalyst. The mixture may be added and stirred for 10 to 40 hours at a temperature ranging from 100 ° C. to 150 ° C., followed by washing with a suitable washing agent such as methanol and water, followed by drying the precipitate formed to obtain a copolymer compound.

Examples of the solvent include propylene glycol monomethyl ether acetic acid (PGMEA), dimethylformamide (DMF), tetrahydrofuran (THF), and the like. Specifically, propylene glycol monomethyl ether acetic acid (PGMEA) may be used.

Examples of the polymerization catalysts include acid anhydrides, amines, imidazoles, hydrazides, and cationics. These can be used individually or in mixture of 2 or more types.

Specifically, the polymerization catalyst is 2-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole. , 2-phenyl-4-benzylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4 -Benzyl-5-hydroxymethylimidazole, 4,4'-methylenebis- (2-ethyl-5-methylimidazole), 2-aminoethyl-2-methylimidazole, 1-cyanoethyl It may be imidazole type such as 2-phenyl-4,5-di (cyanoethoxymethyl) imidazole, and may be aromatic diazonium salt, aromatic sulfonium salt, aliphatic sulfonium salt, aromatic iodine aluminum salt, phosphonium salt, Onium salt compounds such as pyridinium salts and serenium salts; Complex compounds such as metal arene complexes and silanol / aluminum complexes; It may be a cationic latent curing agent such as a compound that contains an electron capture function such as benzoin tosylato- and o-nitrobenzyl tosylato-, including tosyreto groups such as ortho-Nitrobenzyl tosylato-. More specifically, imidazole series polymerization catalysts such as 2-methylimidazole, 2-ethylimidazole or 2-phenyl-4,5-dihydroxymethylimidazole can be used.

In one embodiment, the copolymer compound may be a compound having a structure of any one of Formulas 2 to 4.

[Formula 2]

[Formula 3]

[Formula 4]

In Formulas 2 to 4, R ₁ , R ₂ , R _3, and R ₄ are the same as or different from each other, and are each independently hydrogen or an alkyl group, halogen atom, or hydroxy group of C _1-6 , and R ₅ and R ₆ are the same as each other. or it is different and each independently represents hydrogen, an alkyl group, a halogen atom, C _6-20 or C _6-20 aromatic ring of a C _1-6 alicyclic ring, n is an integer from 1 to 100.

The copolymer compound includes a structure derived from a fluorene-based compound and a bisphenol-type epoxy compound as one repeating unit, and thus has high heat resistance due to the fluorene structure, while -CH _2- , between the aromatic rings of the bisphenol-type epoxy compound, It has a high glass transition temperature (Tg) due to a carbon skeleton such as -CH (CH ₃ )-, -C (CH ₂ )-or -C (CH ₃ ) _2- , or a flexible skeleton such as -SO ₂ skeleton and high temperature. There is also an upright characteristic. In addition, by using the copolymer compound in the composition for an anisotropic conductive film, the storage stability of the produced anisotropic conductive film can be improved.

The glass transition temperature of the copolymer compound may range from 140 ° C to 200 ° C. Specifically, the temperature may be in the range of 150 ° C to 180 ° C, more specifically 160 ° C to 170 ° C. In the above range, the flowability of the anisotropic conductive film prepared from the composition for an anisotropic conductive film including the same can be adjusted, and when used with the conductive particles, the trapping rate of the conductive particles can be improved.

The weight average molecular weight of the copolymer compound may be in the range of 5,000 to 50,000, specifically, may be in the range of 10,000 to 30,000. The anisotropic conductive film made of the composition for an anisotropic conductive film including the same in the above range may have a suitable strength.

The copolymer compound may be included in 20% by weight to 70% by weight based on the total weight of solids of the composition for an anisotropic conductive film. Specifically, the content may be included in an amount of 30 wt% to 60 wt%, more specifically 35 wt% to 55 wt%. Within this range, the flowability and adhesion of the prepared composition for anisotropic conductive film can be improved.

In another embodiment, the composition for the anisotropic conductive film may further include another binder resin in addition to the copolymer compound.

As said other binder resin, polyimide resin, polyamide resin, phenoxy resin, polymethacrylate resin, polyacrylate resin, polyurethane resin, polyester resin, polyesterurethane resin, polyvinyl butyral resin, styrene Butyrene-styrene (SBS) resin and epoxy modified body, styrene- ethylene-butylene- styrene (SEBS) resin and its modified body, or acrylonitrile butadiene rubber (NBR), its hydrogenated body, etc. are mentioned. Can be. These may be contained in the composition for anisotropic conductive films individually or in mixture of 2 or more types.

When another binder resin other than the copolymerization compound is further included, the content of the other binder resin may be included in an amount of 1 wt% to 20 wt% based on the total weight of solids of the composition for anisotropic conductive films.

The epoxy resin having an epoxy equivalent of 150 g / eq or less is not particularly limited, and an epoxy equivalent of 150 g / eq or less may be used without limitation. Specifically, an epoxy resin having an epoxy equivalent of 80 to 150 g / eq may be used, and more specifically, an epoxy resin having 90 to 145 g / eq may be used. If the epoxy equivalent is in the above range, the viscosity and flow characteristics of the anisotropic conductive film may be good, there is an advantage that can achieve a low temperature rapid curing.

Non-limiting examples of the epoxy resins include bisphenol A epoxy resin, bisphenol A epoxy acrylate resin, bisphenol F epoxy resin, bisphenol AD epoxy resin, bisphenol E epoxy resin and bisphenol S epoxy resin Epoxy compounds; Aromatic epoxy compounds such as polyglycidyl ether epoxy resins, polyglycidyl ester epoxy resins and naphthalene epoxy resins; Alicyclic epoxy compounds; Novolak-type epoxy compounds, such as a cresol novolak-type epoxy resin and a phenol novolak-type epoxy resin; Glycidyl amine epoxy compounds; Glycidyl ester epoxy compounds; And biphenyl diglycidyl ether epoxy compounds. Specifically, the epoxy resin may be an alicyclic epoxy resin, a bisphenol type epoxy resin or an aromatic epoxy resin, and more specifically, an alicyclic epoxy resin. Since the cycloaliphatic epoxy resin has an epoxy structure in close proximity to the cycloaliphatic ring, the ring-opening reaction is fast, so that curing may occur faster than other epoxy resins. The alicyclic epoxy resin may be used without limitation as long as the alicyclic epoxy resin has a structure in which an epoxy structure is present through a direct bond or connected to another alicyclic ring.

In one embodiment, the epoxy equivalent of the epoxy equivalent of 150g / eq or less may include a liquid epoxy resin. In the case of including the liquid epoxy resin, there is an advantage that can impart fluidity to the anisotropic conductive film made of the composition for an anisotropic conductive film comprising the same and to speed the curing rate.

The epoxy resin may be included in 20 to 50% by weight based on the total weight of solids of the composition for anisotropic conductive film, specifically 25 to 45% by weight, more specifically 30 to 40% by weight Can be. Curing may sufficiently occur in the above range, the adhesive strength, appearance, etc. of the anisotropic conductive film prepared with the composition for anisotropic conductive film comprising the same may be stable after reliability.

In one embodiment, the composition for the anisotropic conductive film may further include an epoxy resin having an epoxy equivalent of more than 150g / eq in addition to the epoxy resin having an epoxy equivalent of 150g / eq or less.

The composition for the anisotropic conductive film includes the copolymer compound and an epoxy resin having an epoxy equivalent of 150 g / eq or less, thereby controlling flowability at high temperatures, thereby improving the rate of trapping of conductive particles, and enabling low temperature rapid curing. It can be excellent in adhesive strength and connection resistance. When the epoxy equivalent additionally contains more than 150g / eq epoxy resin, it may be included in 1% by weight to 10% by weight based on the total weight of solids of the composition for anisotropic conductive film.

The conductive particles are not particularly limited and may be used conductive particles commonly used in the art. Non-limiting examples of the conductive particles that can be used include metal particles including Au, Ag, Ni, Cu, solder, and the like; carbon; Particles coated with a metal containing Au, Ag, Ni, etc., using resins containing polyethylene, polypropylene, polyester, polystyrene, polyvinyl alcohol, and the like, and modified resins thereof as particles; Insulated electroconductive particle etc. which coat | covered the insulating particle further on it are mentioned. The size of the conductive particles may be, for example, in the range of 1 μm to 20 μm, specifically 1 μm to 10 μm, depending on the pitch of the circuit applied.

The conductive particles may be included in an amount of 1 wt% to 30 wt%, specifically 10 wt% to 25 wt%, and more specifically 15 wt% to about the total weight of solids of the composition for anisotropic conductive films. It may be included in 20% by weight. In the above range, the conductive particles can be easily pressed between the terminals to ensure stable connection reliability, and the connection resistance can be reduced by improving the conductance.

The curing agent may be used without particular limitation as long as it is a curing agent of the epoxy curing type, non-limiting examples include acid anhydrides, amines, imidazoles, hydrazides, cationics and the like. These can be used individually or in mixture of 2 or more types.

Specifically, the curing agent may be cationic, and examples thereof include ammonium / antimony hexafluoride and the like.

Since the curing agent is used by mixing with the epoxy resin at room temperature, it should not have reactivity with the epoxy resin at room temperature after mixing, it has to be active at a certain temperature or more to be active with the epoxy resin to be expressed physical properties. Thus, the curing agent may use a compound capable of generating a cation by thermal activation energy, for example, a cationic latent curing agent.

Specifically, the cationic latent curing agent includes onium salt compounds such as aromatic diazonium salts, aromatic sulfonium salts, aliphatic sulfonium salts, aromatic iodine aluminum salts, phosphonium salts, pyridinium salts, and serenium salts; Complex compounds such as metal arene complexes and silanol / aluminum complexes; Compounds having an electron capturing function, including tosyreto groups such as benzoin tosylato- and o-nitrobenzyl tosylato-, may be used. More specifically, sulfonium salt compounds such as aromatic sulfonium salt compounds or aliphatic sulfonium salt compounds having high cation generation efficiency can be used.

In addition, when such a cationic latent curing agent forms a salt structure, hexafluoroantimonate, hexafluorophosphate, tetrafluoroborate, pentafluorophenyl borate, or the like may be used as a counter ion when forming a reactive side salt. Can be.

The curing agent may be included in 0.5 wt% to 10 wt% based on the total weight of solids of the composition for anisotropic conductive film. Specifically, 2 wt% to 7 wt% may be included. Within this range, sufficient reaction occurs for curing and excellent physical properties can be expected in bonding strength, reliability and the like after bonding through the formation of a suitable molecular weight.

In addition, the composition for anisotropic conductive film of the present invention may further include additives such as polymerization inhibitors, antioxidants, heat stabilizers, to provide additional physical properties without inhibiting the basic physical properties. The additive is not particularly limited, but may be included in an amount of 0.01 wt% to 10 wt% based on the total weight of solids of the composition for anisotropic conductive films.

As a non-limiting example, the anti-polymerization agent can be selected from the group consisting of hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, phenothiazine and mixtures thereof. In addition, the antioxidant may be a phenolic or hydroxy cinnamate-based material, and specifically, tetrakis- (methylene- (3,5-di-t-butyl-4-hydroxycinnamate) methane, 3,5 -Bis (1,1-dimethylethyl) -4-hydroxy benzene propanoic acid thiol di-2,1-ethanediyl ester and the like can be used.

Hereinafter, an anisotropic conductive film according to another embodiment of the present invention will be described.

The anisotropic conductive film according to the present embodiment includes a copolymer compound of a fluorene-based compound and a bisphenol-type epoxy compound, and the film is press-bonded under the conditions of 50 ° C. to 80 ° C., 1 to 3 seconds and 1.0 MPa to 3.0 MPa, The particle capture rate according to Equation 1 measured after main compression under 120 ° C. to 160 ° C. for 3 to 6 seconds and under a pressure condition of 60 MPa to 80 MPa may be 30% or more, and the adhesive force may be 10 MPa or more.

As the copolymer compound of the fluorene-based compound and the bisphenol-type epoxy compound, the same compounds as described in the previous examples can be used.

The anisotropic conductive film is press-bonded under the conditions of 50 ° C. to 80 ° C., 1 to 3 seconds and 1.0 MPa to 3.0 MPa, and measured after main compression under pressure conditions of 120 ° C. to 160 ° C., 3 to 6 seconds and 60 MPa to 80 MPa. The particle capture rate according to Equation 1 may be 30% or more.

[Equation 1]

Particle capture rate (%) = (number of conductive particles per unit area (mm ² ) of the connection site after pressing and main compression / number of (mm ² ) conductive particles per unit area of the anisotropic conductive film before pressing) × 100

The particle capture rate may be specifically 40% or more, more specifically 50% or more. In the above range, the fluidity of the conductive layer is effectively suppressed, so that the conductive particles are sufficiently positioned on the terminals to improve the electrical conductance, and the outflow of the conductive particles can be reduced to reduce the short between terminals.

The method for measuring the particle capture rate is not particularly limited, and one non-limiting example is as follows: For the prepared anisotropic conductive film, the number of conductive particles (mm ² ) per unit area of the anisotropic conductive film before pressing is determined. Calculate using a particle counter. Thereafter, the anisotropic conductive film is placed between the first to-be-connected member and the second to-be-connected member and press-bonded under the conditions of 50 ° C. to 80 ° C., 1 to 3 seconds and 1.0 MPa to 3.0 MPa, and 120 ° C. to 160 ° C., 3 After main compression for 6 seconds and under a pressure condition of 60 MPa to 80 MPa, the number of (mm ² ) conductive particles per unit area of the connection site is calculated using a particle automatic measuring device, and the particle capture rate is calculated by the above equation 1.

In addition, the anisotropic conductive film may have a bonding strength of 10 MPa or more, specifically, 20 MPa or more, more specifically 30 MPa or more, after the pressure bonding and the main compression. When the adhesive strength of the anisotropic conductive film is in the above range there is an advantage that can be used for a long time using the display device.

Non-limiting examples of the adhesion measurement method are as follows: The prepared anisotropic conductive film was placed on a glass substrate having an indium tin oxide circuit having a bump area of 1200 µm ² and a thickness of 2000 kPa for 50 ° C. to 80 ° C. for 1 to 3 seconds, respectively. And after press-bonding at 1.0MPa to 3.0MPa, the release film was removed and the bump chip area of 1200㎛ ² , 1.5T thick IC chip was raised and viewed under the conditions of 120 ℃ to 160 ℃, 3-6 seconds and 60MPa to 80MPa The specimen is prepared by pressing, and measured using a peel strength tester (Bond tester Dage Series-4000) under conditions of Maximum load: 200kgf, Test speed: 100um / sec.

The anisotropic conductive film may further include an epoxy resin, conductive particles, and a curing agent having an epoxy equivalent of 150 g / eq or less. For the above components, the same ones as described in the previous embodiment can be used.

In one embodiment, the anisotropic conductive film may be used in a chip on glass (COG) or chip on film (COF) mounting method.

The anisotropic conductive film may have a minimum melt viscosity of 5,000 to 20,000 Pa · s at 30 ° C. to 200 ° C. according to the ARES measurement, and specifically, may be 6,000 to 10,000 Pa · s. In the above range, sufficient adhesive force may be expressed, pressure adhesion may be improved, and an insulating layer between terminals may be sufficiently filled to improve connection reliability.

The method of measuring the minimum melt viscosity is not particularly limited, and non-limiting examples are as follows: using an ARES G2 rheometer (TA Instruments), sample thickness 150 μm, temperature increase rate 10 ° C./min, stress 5% The lowest melt viscosity of the anisotropic conductive film is measured in the range of 30 ° C. to 200 ° C. at a frequency of 10 rad / sec.

In addition, the anisotropic conductive film may have a curing rate of 80% or more according to the following Equation 2, specifically 85% or more, more specifically 90% or more.

[Equation 2]

Curing Rate (%) = [(H ₀ -H ₁ ) / H ₀ ] × 100

In Equation 2, H ₀ is an anisotropic conductive film is measured by the area under the curve at 10 ℃ / min, -50 ℃ to 250 ℃ temperature section using a DSC (thermodifferential scanning calorimetry, TA instruments, Q20) One initial calorific value, H ₁ represents the calorific value measured by the same method after leaving for 5 seconds at 130 ℃ on a hot plate (hot plate).

The curing rate in the above range is related to the low temperature fast curing property of the anisotropic conductive film because it reflects the rapid progress of curing in a short time of 5 seconds at a low temperature of 130 ° C., for example.

In another embodiment, the anisotropic conductive film is press-bonded at 50 ° C. to 80 ° C., 1 to 3 seconds and 1.0 MPa to 3.0 MPa, and main compression under pressure conditions of 120 ° C. to 160 ° C., 3 to 6 seconds and 60 MPa to 80 MPa. After the measured initial connection resistance may be less than 1.0Ω. Specifically, it may be 0.7Ω or less, more specifically 0.5Ω or less.

In addition, the anisotropic conductive film, after the pressure bonding and the main compression, the connection resistance may be 3Ω or less after the reliability evaluation measured by standing for 500 hours under the conditions of the temperature 85 ℃ and 85% relative humidity. Specifically, it may be 2Ω or less, and more specifically 1Ω or less.

The anisotropic conductive film having the connection resistance range after the initial connection resistance and the reliability evaluation has the advantage of not only improving the connection reliability but also maintaining the long-term storage stability.

The method for measuring the connection resistance after the initial connection resistance and the reliability evaluation is not particularly limited, and non-limiting examples are as follows: An anisotropic conductive film is a glass substrate having an indium tin oxide circuit having a bump area of 1200 µm ² and a thickness of 2000 GPa. After pressing and pressing at 50 ° C. to 80 ° C., 1 to 3 seconds, and 1.0 MPa to 3.0 MPa, respectively, the release film was removed and the IC chip having a bump area of 1200 μm ² and a thickness of 1.5T was placed thereon, and then 120 ° C. to 160 ° C. , The specimen was prepared by main compression under the conditions of 3 to 6 seconds and 60 MPa to 80 MPa, and the resistance between 4 points was measured using the 4 point probe method and expressed as initial connection resistance. Thereafter, the specimen prepared by the main compression was allowed to stand for 500 hours under a condition of 85 ° C. and a relative humidity of 85%, and then the resistance was measured in the same manner. The resistance measuring instrument applies 1mA and calculates and displays the resistance with the measured voltage.

In one embodiment, the anisotropic conductive film may have a structure in which an insulating layer is laminated on one side or both sides of the conductive layer. That is, a two-layer structure in which a conductive layer and an insulating layer are laminated or a conductive layer may be laminated in an insulating layer, and the insulating layer may be a three-layer structure in which the insulating layer is laminated. It may be a multilayer structure laminated in layers or more.

The term “lamination” means that another layer is formed on one surface of an arbitrary layer, and may be used in combination with a coating or lamination. In the case of an anisotropic conductive film having a multilayered structure including a conductive layer and an insulating layer separately, even if the content of inorganic particles such as silica is high, since the layers are separated, the conductive particles do not interfere with the crimping of the conductive particles. Since the flowability of the composition for anisotropic conductive films can be influenced, the anisotropic conductive film by which fluidity was controlled can be manufactured.

Another embodiment of the present invention relates to a method for producing an anisotropic conductive film. No particular apparatus or equipment is necessary to form the anisotropic conductive film of the present invention. For example, after dissolving the composition for anisotropic conductive film including each composition disclosed herein in an organic solvent such as toluene and liquefying, stirring for a predetermined time within a rate range in which the conductive particles are not crushed, it is a constant thickness on the release film For example, an anisotropic conductive film can be obtained by applying a thickness of 10 μm to 50 μm and then drying for a predetermined time to volatilize toluene or the like.

Hereinafter, a display apparatus according to still another embodiment of the present invention will be described.

The display device includes a first to-be-connected member containing a first electrode; A second to-be-connected member containing a second electrode; And a display device connected between the first to-be-connected member and the second to-be-connected member and connected by the anisotropic conductive film according to the embodiments described herein to connect the first electrode and the second electrode. Can be.

The first to-be-connected member or the second to-be-connected member is formed with an electrode that requires electrical connection. Specifically, indium tin oxide (ITO) or indium zinc oxide (IZO) or the like used in a liquid crystal display It may be a glass substrate or a plastic substrate, a printed wiring board, a ceramic wiring board, a flexible wiring board, a semiconductor silicon chip, an IC chip or a driver IC chip on which electrodes of the electrode are formed, and more specifically, the first connected member and the second connected member. Either one may be an IC chip or a driver IC chip and the other may be a glass substrate.

Referring to FIG. 1, the display device 30 will be described. The first connected member 50 including the first electrode 70 and the second connected member 60 including the second electrode 80 may be described. Is an anisotropic conductive film (10) comprising conductive particles (3) as described herein, which is located between the first to-be-connected member and the second to-be-connected member to connect the first electrode and the second electrode. Can be bonded together.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Example

Production Example  1 to 4: Preparation of Copolymer Compound

Production Example  1: Preparation of Copolymer Compound 1

14 g of 9,9'-Bis (4-hydroxyphenyl) fluorene and 16 g of bisphenol F-type epoxy resin (YSLV-80XY, Kukdo Chemical) were dissolved in 30 g of PGMEA, 0.1 g of 2-Methyl imidazole was added and stirred at 110 ° C. for 24 hours. It was. After stirring, the mixture was washed with methanol and water, and then the precipitate formed was dried to prepare Copolymer Compound 1 (Tg: 170 ° C, weight average molecular weight: 25,000) having the following structure.

[Copolymerization Compound 1]

Production Example  2: Preparation of Copolymer Compound 2

15 g of 9,9'-Bis (4-hydroxyphenyl) fluorene and 10 g of bisphenol A epoxy resin (JER834, Mitsubishi Chemical) were dissolved in 30 g of PGMEA, 0.1 g of 2-Methyl imidazole was added thereto, and the mixture was stirred at 110 ° C. for 24 hours. After stirring, the mixture was washed with methanol and water, and then the precipitate formed was dried to prepare Copolymer Compound 2 (Tg: 165 ° C., weight average molecular weight: 20,000) having the following structure.

[Copolymerization Compound 2]

Production Example  3: Preparation of Copolymer Compound 3

Dissolve 10 g of 1,1'-Bis (4-hydroxyphenyl) methane in 30 g of PGMEA with 15 g of 9,9'-Bis (4-hydroxyphenyl) fluorene and bisphenol F-type epoxy resin, add 0.1 g of 2-Methyl imidazole, and add 110 g. It stirred at 24 degreeC. After stirring, the mixture was washed with methanol and water, and then the precipitate formed was dried to prepare Copolymer Compound 3 (Tg: 165 ° C., weight average molecular weight: 22,000) having the following structure.

[Copolymer Compound 3]

Example  And Comparative example

Example  One

40 parts by weight of the copolymer compound 1 prepared in Preparation Example 1 as a binder resin for forming a film, 35 parts by weight of an epoxy resin (Daicel celloxide 2021P) having an epoxy equivalent of 130 g / eq, a thermosetting latent curing agent (HX3741, Asahi Kasei, Japan) 5 parts by weight, for anisotropic conductive films by mixing 20 parts by weight of insulated conductive particles (AUL-704, average particle size 4um, SEKISUI, Japan) as a filler for imparting conductive performance to the anisotropic conductive film. The composition was prepared. After apply | coating the said composition for anisotropic conductive films on a release film, the solvent was volatilized for 5 minutes in a 70 degreeC dryer, and the 15-micrometer-thick dried anisotropic conductive film was obtained.

Example  2

Example 1, except that copolymer compound 2 prepared in Preparation Example 2 was used as the binder resin, and epoxy resin 2 (HP4032D, Dinippon ink) having an epoxy equivalent of 143 g / eq was used as the epoxy resin. An anisotropic conductive film of Example 2 was prepared under the same conditions and methods.

Example  3

Example 1, except that copolymer compound 3 prepared in Preparation Example 3 was used as the binder resin, and epoxy resin 3 (JER630ESD, Japan epoxy resin) having an epoxy equivalent of 97 g / eq was used as the epoxy resin. The anisotropic conductive film of Example 3 was manufactured under the same conditions and methods as in Example 1.

Comparative example  One

Comparative Example 1 was the same as in Example 1, except that biphenyl fluorene type binder resin (FX-293, Shin-Il Chem Chem, Tg: 165 ℃, molecular weight: 45,000) as the binder resin An anisotropic conductive film of 1 was prepared.

Comparative example  2

In Example 1, an anisotropic conductive film of Comparative Example 2 was prepared under the same conditions and methods as in Example 1, except that an epoxy resin (YDPN 638, Kukdo Chemical) having an epoxy equivalent of 180 g / eq was used as the epoxy resin. .

Experimental Example

For the anisotropic conductive films of Examples 1 to 3 and Comparative Examples 1 and 2 prepared above, the lowest melt viscosity, curing rate, particle capture rate, adhesive force, and connection resistance were measured by the following conditions and methods. Indicated.

Experimental Example  1: lowest Melt viscosity  Measure

Using the ARES G2 rheometer (TA Instruments) for the anisotropic conductive films prepared in the above Examples and Comparative Examples, the sample thickness is 150㎛, temperature rise rate 10 ℃ / min, stress 5%, frequency 10rad / sec 30 ℃ to 200 The lowest melt viscosity was measured in the ℃ section.

Experimental Example  2 : Hardening rate  Measure

1 mg aliquots of the anisotropic conductive films prepared in Examples and Comparative Examples were used to obtain an initial temperature at 10 ° C./min, -50 ° C. to 250 ° C. under a nitrogen gas atmosphere using DSC (thermodifferential scanning calorimetry, TA instruments, Q20). The calorific value is measured by the area under the curve (H ₀ ), and then the film is left on a hot plate for 5 seconds at 130 ° C., and then the calorific value is measured in the same manner (H ₁ ), and the equation is obtained from Equation 2 below. The cure rate accordingly was calculated.

 [Equation 2]

Curing Rate (%) = [(H ₀ -H ₁ ) / H ₀ ] × 100

Experimental Example  3: Of particle capture rate  Measure

For the anisotropic conductive films prepared in the above Examples and Comparative Examples, the number of (mm ² ) conductive particles per unit area of the anisotropic conductive film before pressure bonding was calculated using a particle automatic measuring device (ZOOTUS).

In addition, the anisotropic conductive film was placed on a glass substrate (manufactured by Neoview Kolon) having an indium tin oxide circuit having a bump area of 1200 µm ² and a thickness of 2000 kPa, and press-bonded at 1 MPa for 1 second at 70 ° C., respectively, and then the release film was removed. Then, the IC chip (Samsung LSI) with a bump area of 1200㎛ ² and 1.5T thickness was put up, and then they were main compressed at 130 ℃ for 5 seconds and 70MPa, and the number of conductive particles (mm ² ) per unit area of the connection site was Was calculated using the particle size analyzer and particle capture rate was calculated by the following Equation 1.

[Equation 1]

Particle capture rate (%) = (number of conductive particles per unit area (mm ² ) of the connection site after pressing and main compression / number of (mm ² ) conductive particles per unit area of the anisotropic conductive film before pressing) × 100

Experimental Example  4: measurement of adhesion

The anisotropic conductive films prepared in the above Examples and Comparative Examples were placed on a glass substrate (manufactured by Neoview Kolon) with an indium tin oxide circuit having a bump area of 1200 μm ² and a thickness of 2000 μm, respectively, and pressurized at 1 MPa for 1 second at 70 ° C. Good. After the press-bonding, the release film was removed and the bump area 1200 μm ² and the thickness 1.5T IC chip (manufacturer: Samsung LSI) were put up and then pressed at 130 ° C. for 5 seconds at 70 MPa to prepare a specimen. The average of these was measured three times or more for each specimen using a peel strength tester (Bond tester Dage Series-4000) under the conditions of Maximum load: 200kgf, Test speed: 100㎛ / sec.

Experimental Example  5: Measurement of connection resistance after initial and reliability evaluation

The anisotropic conductive films prepared in the above Examples and Comparative Examples were placed on a glass substrate (manufactured by Neoview Kolon) with an indium tin oxide circuit having a bump area of 1200 μm ² and a thickness of 2000 μm, respectively, and pressurized at 1 MPa for 1 second at 70 ° C. Good. After the press-bonding, the release film was removed and bumped area 1200 μm ² , 1.5T thick IC chip (manufacturer: Samsung LSI) were put up, and then pressed at 5 ° C. under conditions of 70 MPa at 130 ° C. to prepare a specimen. The resistance between 4 points was measured using the 4 point probe method and this was expressed as initial connection resistance. Subsequently, the specimen prepared by main compression was allowed to stand for 500 hours under a condition of 85 ° C. and 85% relative humidity, and then the resistance was measured in the same manner.

The resistance measuring instrument applies 1mA and calculates the average of the resistance by using the measured voltage.

	Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
Melt Viscosity (Pas)	10,000	7,000	8,500	25,000	45,000
Curing rate (%)	87	86	88	65	70
Particle Capture Rate (%)	33	34	32	18	16
Adhesive force (MPa)	33	32	34	30	28
Initial connection resistance (Ω)	0.02	0.03	0.03	0.05	0.07
Connection resistance (Ω) after reliability evaluation	0.12	0.13	0.12	1.20	1.50

As shown in Table 1, the copolymer compound of the fluorene-based compound and the bisphenol-type epoxy resin; And the anisotropic conductive films of Examples 1 to 3 containing an epoxy resin having an epoxy equivalent of 150 g / eq or less showed excellent physical properties in connection resistance after the lowest melt viscosity, cure rate, particle capture rate, adhesive strength, initial stage and reliability evaluation. . On the other hand, Comparative Example 1, which does not use a copolymer of a fluorene-based compound and a bisphenol-type epoxy resin, has a high minimum melt viscosity and a low curing rate at 130 ° C. due to the low Tg of the binder resin, and a low particle capture rate. After the reliability evaluation, the connection resistance was found to increase significantly. Comparative Example 2 using an epoxy resin having an epoxy equivalent of more than 150 g / eq showed the lowest melt viscosity due to poor flow characteristics, and the curing rate and particle capture rate were lowered as in Comparative Example 1, compared to Examples. After the reliability evaluation, the connection resistance increased significantly.

Claims (19)

1. Copolymerized compounds of fluorene-based compounds and bisphenol-type epoxy compounds; Epoxy resins having an epoxy equivalent weight of 150 g / eq or less; Curing agent; And conductive particles comprising conductive particles.
2. The composition for anisotropic conductive films according to claim 1, wherein the fluorene-based compound contains two or more hydroxyl groups.
3. The composition for anisotropic conductive films of Claim 2 in which the said fluorene type compound has a structure of following General formula (1).

   [Formula 1]

   

   In Formula 1, R is each independently an alkyl group, an alkoxy group, an aryl group or a cycloalkyl group,

   m is each independently an integer of 0 to 4,

   n is each independently an integer of 1-5.
4. The anisotropic conductive film according to claim 1, wherein the bisphenol type epoxy compound is a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol AD type epoxy compound, a bisphenol E type epoxy compound, a bisphenol S type epoxy compound, or a combination thereof. Composition.
5. The composition for anisotropic conductive films according to claim 1, wherein the copolymer compound has a structure of any one of the following Chemical Formulas 2 to 4.

   [Formula 2]

   

   [Formula 3]

   

   [Formula 4]

   

   In Chemical Formulas 2 to 4,

   R ₁ , R ₂ , R ₃ and R ₄ are the same as or different from each other, and are each independently hydrogen or an alkyl, halogen atom or hydroxy group of C _1-6 ,

   R ₅ and R ₆ are the same or different and are each independently hydrogen, a alkyl group, a halogen atom, C _6-20 or C _6-20 aromatic ring of a C _1-6 alicyclic ring with each other,

   n is an integer from 1 to 100.
6. The composition for anisotropic conductive films according to claim 1, wherein the weight average molecular weight of the copolymer compound is 5,000 to 50,000.
7. The composition for anisotropic conductive films of Claim 1 whose glass transition temperature (Tg) of the said copolymerization compound is 140 degreeC-200 degreeC.
8. The composition for anisotropic conductive films according to claim 1, wherein the epoxy resin having an epoxy equivalent of 150 g / eq or less is an alicyclic epoxy resin, a bisphenol type epoxy resin, or an aromatic epoxy resin.
9. According to claim 1, Based on the total weight of solids of the composition for anisotropic conductive film,

   20 to 70 weight percent of a copolymer compound;

   20 wt% to 50 wt% of an epoxy resin having an epoxy equivalent weight of 150 g / eq or less;

   0.5 to 10 weight percent curing agent; And

   The composition for an anisotropic conductive film containing 1 weight%-30 weight% of conductive particles.
10. An anisotropic conductive film containing a copolymer of a fluorene-based compound and a bisphenol-type epoxy compound, and conductive particles,

    The film was press-bonded under the conditions of 50 ° C. to 80 ° C., 1 to 3 seconds and 1.0 MPa to 3.0 MPa, and measured after main compression under pressure conditions of 120 ° C. to 160 ° C., 3 to 6 seconds and 60 MPa to 80 MPa. The anisotropically conductive film whose particle | grain capture rate in accordance with 1 is 30% or more, and adhesive force is 10 MPa or more.

    [Equation 1]

    Particle capture rate (%) = (number of conductive particles per unit area (mm ² ) of the connection site after pressing and main compression / number of (mm ² ) conductive particles per unit area of the anisotropic conductive film before pressing) × 100
11. The anisotropic conductive film of claim 10, wherein the fluorene-based compound includes two or more hydroxyl groups.
12. The anisotropic conductive film of claim 11, wherein the fluorene-based compound has a structure represented by Formula 1 below.

    [Formula 1]

    

    In Chemical Formula 1,

    Each R is independently an alkyl group, an alkoxy group, an aryl group, or a cycloalkyl group,

    m is each independently an integer of 0 to 4,

    n is each independently an integer of 1-5.
13. The anisotropic conductive film of claim 10, wherein the copolymer compound has a structure of any one of Formulas 2 to 4 below.

    [Formula 2]

    

    [Formula 3]

    

    [Formula 4]

    

    In Chemical Formulas 2 to 4,

    R ₁ , R ₂ , R ₃ and R ₄ are the same as or different from each other, and are each independently hydrogen or an alkyl, halogen atom or hydroxy group of C _1-6 ,

    R ₅ and R ₆ are the same or different and are each independently hydrogen, a alkyl group, a halogen atom, C _6-20 or C _6-20 aromatic ring of a C _1-6 alicyclic ring with each other,

    n is an integer from 1 to 100.
14. The anisotropic conductive film of claim 10, wherein the anisotropic conductive film is used in a chip on glass (COG) or chip on film (COF) mounting method.
15. The anisotropic conductive film of Claim 10 whose minimum melt viscosity in 30 degreeC-200 degreeC according to ARES measurement is 5,000-20,000 Pa.s.
16. The anisotropically conductive film of Claim 10 whose initial connection resistance measured after the said pressure bonding and main compression bonding is 1.0 ohm or less.
17. The anisotropic conductive film according to claim 10, wherein the connection resistance is 3 Ω or less after reliability evaluation measured by standing for 500 hours under conditions of a temperature of 85 ° C. and a relative humidity of 85% after the pressing and main pressing.
18. The anisotropic conductive film of Claim 10 whose hardening rate by following formula (2) is 80% or more.

    [Equation 2]

    Curing Rate (%) = [(H ₀ -H ₁ ) / H ₀ ] × 100

    In Equation 2, H ₀ is the initial calorific value of the anisotropic conductive film measured by the area under the curve at a temperature range of 10 ° C./min, −50 ° C. to 250 ° C. under a nitrogen gas atmosphere using a differential thermal scanning calorimeter (DSC), H ₁ represents the calorific value measured by the same method after standing at 130 ° C. for 5 seconds on a hot plate.
19. A first to-be-connected member containing a first electrode;

    A second to-be-connected member containing a second electrode; And

    The display apparatus connected by the anisotropic conductive film of Claims 10-18 which is located between the said 1st to-be-connected member and the said 2nd to-be-connected member, and connects the said 1st electrode and the said 2nd electrode.

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