KR20190046567A - Anisotropic conductive film, connection structure comprising the same and display apparatus comprising the same - Google Patents

Abstract

Provided is an anisotropic conductive film comprising a binder, a radical polymerizing substance, a curing agent, inorganic particles, and conductive particles. Specifically, provided are: the anisotropic conductive film having a haze of 50% or more, wherein the inorganic particles have an average particle diameter (D10) of 0.1 to 0.5 μm, and the conductive particles have the average particle diameter (D10) of 0.1 to 1 μm; a connection structure comprising the same; and a display apparatus comprising the same.

Description

TECHNICAL FIELD [0001] The present invention relates to an anisotropic conductive film, a connection structure including the same, and a display device including the anisotropic conductive film.

The present invention relates to an anisotropic conductive film, a connection structure including the same, and a display device including the same. More specifically, the present invention relates to an anisotropic conductive film which is excellent in adhesion and connection resistance after initial and reliability evaluation, and which can easily confirm whether the anisotropic conductive film is completely pressed, a connection structure including the anisotropic conductive film, and a display device .

The anisotropic conductive film is a film-like adhesive in which conductive particles such as metal coated plastic or metal particles are dispersed. Anisotropic conductive films are widely used for circuit connection in the field of flat panel displays and component mounting in semiconductor fields. When an anisotropic conductive film is placed between the circuits to be connected and subjected to a thermocompression process by temperature, pressure and time, the circuit terminals are electrically connected by the conductive particles and the space between the adjacent circuit terminals is electrically insulated The resin is filled and the conductive particles exist independently of each other, so that the insulating property is given.

In recent years, in connection with liquid crystal panels using wiring patterns made of aluminum or chromium, in which an oxide film is likely to be formed on the surface of the electrode pattern, demands for miniaturization and miniaturization of circuit electrodes and thinning and electrode formation have increased, There is a problem of improving the insulation characteristics and the collection rate.

Therefore, the content of inorganic particles such as conductive particles and silica is increased in order to improve the insulating property and flow rate adjustment of the anisotropic conductive film composition, resulting in an increase in defects due to a decrease in dispersibility. In addition, efforts are being made to improve the process to reduce the tack time for the productivity improvement in the mass production process, and it is necessary to provide an anisotropic conductive film having appropriate haze when applied to mass production.

The transparency of the anisotropic conductive film is generally high because the conductive particles are dispersed in the binder portion containing the thermoplastic resin. Therefore, even after the film is pressed on the circuit member, the presence or absence of the film can not be easily confirmed. This may be accompanied by an increase in manufacturing cost due to malfunction of the compression device. Therefore, when a pigment or a dye is added to the anisotropic conductive film to make it colored, it can be easily confirmed whether or not the film exists after pressurization. However, dyes such as pigments can deteriorate electrical properties, including adhesive strength, connection resistance, insulation resistance and the like, which are basically required for anisotropic conductive films.

A problem to be solved by the present invention is to provide an anisotropic conductive film which makes it possible to easily confirm whether or not a colored material such as a pigment or a dye is contained.

Another object to be solved by the present invention is to provide an anisotropic conductive film excellent in adhesion and connection resistance after initial and reliability evaluation.

The anisotropic conductive film of the present invention comprises a binder, a radical polymerizing substance, a curing agent, inorganic particles and conductive particles, wherein the anisotropic conductive film has a haze of 50% or more, and the inorganic particles have an average particle diameter (D10) And the average particle diameter (D10) of the conductive particles may be 0.1 占 퐉 or more and 1 占 퐉 or less.

The connection structure of the present invention may include the anisotropic conductive film of the present invention.

The display device of the present invention may include the anisotropic conductive film of the present invention.

The present invention provides an anisotropic conductive film which makes it possible to easily confirm whether pressure bonding is completed even when a pigment or dye is not contained.

The present invention provides an anisotropic conductive film excellent in adhesion and connection resistance after initial and reliability evaluations.

Below, Embodiments of the present application will be described in more detail. However, the techniques disclosed in this application are not limited to the embodiments described herein but may be embodied in other forms. It should be understood, however, that the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the present specification, "average particle diameter (D10)", "average particle diameter (D50)" and "average particle diameter (D90)" refer to the particle diameters of inorganic particles or conductive particles, Means a particle diameter corresponding to 10% by weight, 50% by weight and 90% by weight, respectively, when the cumulative curve of mass is drawn. Inorganic particle And particle diameters of the conductive particles can be measured using a particle size analyzer (Simpatec).

The anisotropic conductive film of the present invention may have a haze of 50% or more in a visible light region (e.g., a wavelength of 380 nm to 780 nm). Within the above-mentioned range, it is possible to easily confirm whether or not the film of the anisotropic conductive film is pressed. Preferably, the haze may be 50% or more and 90% or less, more preferably 50% or more and 80% or less, and most preferably 65% or more and 75% or less. Within the above range, it can be suitably used in an optical display device. The anisotropic conductive film of the present invention does not contain colored materials such as dyes and pigments, but the haze can be secured to 50% or more by controlling the average particle size of the inorganic particles and the conductive particles and the content thereof.

The anisotropic conductive film of the present invention comprises a binder resin, a radical polymerizing substance, a curing agent, inorganic particles and conductive particles, wherein an average particle diameter (D10) of the inorganic particles is 0.1 m or more and 0.5 m or less, Can be 0.1 탆 or more and 1 탆 or less.

Inorganic particle

The average particle diameter (D10) of the inorganic particles may be 0.1 占 퐉 or more and 0.5 占 퐉 or less. Within the above range, the haze of the anisotropic conductive film of the present invention can be ensured together with the conductive particles. It may be advantageous for the anisotropic conductive film to contain inorganic particles having a lower average particle diameter (D10) in order to increase the haze of the anisotropic conductive film. However, if the average particle size (D10) of the inorganic particles is too low, May be deteriorated. The present invention can secure the haze of the anisotropic conductive film by controlling the average particle diameter (D10) of the inorganic particles. Preferably, the inorganic particles may have an average particle diameter (D10) of 0.2 mu m or more and 0.4 mu m or less.

The average particle diameter (D90) of the inorganic particles may be 1 mu m or more and 3 mu m or less. Within the above range, the haze and the transparency of the anisotropic conductive film can be adjusted to improve the processability, and the flow property of the composition can be controlled to improve the adhesive strength and the connection reliability. The inorganic particles may have an average particle diameter (D50) of 0.5 mu m or more and 1.5 mu m or less, preferably 0.7 mu m or more and 1.2 mu m or less. Within the above range, the haze and the transparency of the anisotropic conductive film can be adjusted to improve the processability, and the flow property of the composition can be controlled to improve the adhesive strength and the connection reliability.

The shape of the inorganic particles may be spherical particles. When the inorganic particles in the form of flakes are included in the anisotropic conductive film, the dispersibility of the inorganic particles tends to be low and the haze of the anisotropic conductive film can be lowered. When the inorganic particles are in the form of fibers, they are unfavorably adversely charged in the anisotropic conductive film, which may affect the connection reliability. When the inorganic particles are in the form of scales, the dispersibility is lowered similarly to the shape of the flakes, and the haze of the anisotropic conductive film can be lowered, which is not preferable.

The inorganic particles may include fillers composed of titanium oxide or boron nitride such as silica, magnesia, bentonite, smectite, alumina, titanium dioxide and the like. Preferably, silica can be used as the inorganic particles. Silica can be silica, silica produced by liquid phase method such as sol-gel method or precipitation method, silica produced by vapor-phase method such as flame oxidation method, and silica powder obtained by pulverizing silica gel. Fumed silica, fused silica, and synthetic silica can be used, and colloidal silica in the form of dispersion in a dispersion can also be used.

The inorganic particles are preferably surface-treated with a silane compound, for example, a silane coupling agent. By surface-treating the surface of the inorganic particles with a silane coupling agent, it is possible to improve wettability and adhesiveness with other components such as a binder and a radical polymerizable substance in the composition for anisotropic conductive films, and to improve fluidity and adhesion strength.

The inorganic particles may be contained in an amount of 0.1 to 30% by weight, preferably 1 to 25% by weight and 5 to 20% by weight in the anisotropic conductive film. Within this range, the pressure applied to the electrode can be uniformly dispersed, the adhesion of the anisotropic conductive film and the connection reliability can be improved, and the haze of the anisotropic conductive film of the present invention can be easily secured.

Conductive particle

The average particle diameter (D10) of the conductive particles may be 0.1 占 퐉 or more and 1 占 퐉 or less. Within the above range, it is possible to secure the haze of the anisotropic conductive film together with the inorganic particles. It may be advantageous that the anisotropic conductive film contains conductive particles having a lower average particle diameter (D10) in order to increase the haze of the anisotropic conductive film. However, if the average particle diameter (D10) of the conductive particles is too low, And lowering of the uniformity may occur, and the fluidity of the anisotropic conductive film composition may also be affected. Preferably, the average particle diameter (D10) of the conductive particles may be 0.3 占 퐉 or more and 0.8 占 퐉 or less.

The conductive particles may have an average particle diameter (D90) of 4 占 퐉 or more and 7 占 퐉 or less, preferably 4.5 占 퐉 or more and 6.5 占 퐉 or less. Within the above range, uniform indentation of the anisotropic conductive film and connection reliability can be ensured. The conductive particles may have an average particle diameter (D50) of 2.5 占 퐉 or more and 4.5 占 퐉 or less, preferably 3 占 퐉 or more and 4 占 퐉 or less. Within the above range, uniform indentation of the anisotropic conductive film and connection reliability can be ensured

The conductive particles may be spherical or protruding particles.

The conductive particles include metal particles including gold, silver, nickel, copper, solder, and the like; Particles coated with a metal containing gold, silver, nickel, copper or solder or the like using a resin including carbon, polyethylene, polypropylene, polyester, polystyrene, polyvinyl alcohol or the like or a modified resin thereof as a core; The metal particles or the particles coated with a coating may further include insulating particles coated with insulating particles to insulate the particles. The conductive particles may be contained singly or in combination of two or more.

The conductive particles may be contained in an anisotropic conductive film in an amount of 1 wt% or more and 20 wt% or less, preferably 3 wt% or more and 10 wt% or less. Within the above range, occurrence of connection and / or insulation failure can be prevented and excellent connectivity can be ensured.

The inorganic particles and the whole conductive particles may be contained in an anisotropic conductive film in an amount of 1 wt% to 50 wt%, preferably 5 wt% to 30 wt%. Within this range, it is possible to increase the haze and increase the connection and insulation reliability.

Binder resin

The binder resin is not particularly limited and binder resins commonly used in the art can be used. Non-limiting examples of the binder resin include acrylonitrile-butadiene rubber (NBR) resin, phenoxy resin, polyurethane resin, acrylic resin, and polyester urethane resin.

The acrylonitrile butadiene rubber resin means a copolymer produced by emulsion polymerization of acrylonitrile and butadiene. The content of each of acrylonitrile and butadiene in the copolymer is not particularly limited, and the polymerization method thereof is not particularly limited. The weight average molecular weight of the acrylonitrile butadiene rubber resin is not particularly limited, but is preferably 50,000 to 1,000,000 g / mol.

The phenoxy resin may include a bisphenol-based phenoxy resin and the like.

The polyurethane resin is a polymer resin having a urethane bond and can be produced by, for example, polymerizing isophorone diisocyanate, polytetramethylene glycol and the like, but is not limited thereto. The weight average molecular weight of the polyurethane resin is not particularly limited, but is preferably 10,000 g / mol to 200,000 g / mol.

The acrylic resin can be obtained by polymerizing an acrylic monomer and / or a polymerizable monomer thereof. For example, the acrylic resin is a copolymer obtained by polymerizing at least one monomer selected from the group consisting of (meth) acrylates having 2 to 10 carbon atoms, (meth) acrylic acid, vinyl acetate and acrylic monomers modified therefrom Lt; / RTI > The polymerization method is not particularly limited. The weight average molecular weight of the acrylic resin is not particularly limited, but is preferably 10,000 g / mol to 200,000 g / mol.

As the polyester urethane resin, a resin obtained by a reaction of a polyester polyol and a diisocyanate can be used. The polyester polyol refers to a polymer having a plurality of ester groups and a plurality of hydroxyl groups. The polyester polyol can be obtained by the reaction of a dicarboxylic acid and a diol. Examples of the dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, adipic acid, sebacic acid, succinic acid, glutaric acid, suberic acid, azelanic acid, dodecanedicarboxylic acid, hexahydrophthalic acid, ortho- There may be mentioned aromatic dicarboxylic acids or aliphatic dicarboxylic acids such as phthalic acid, tetrachlorophthalic acid, 1,5-naphthalene dicarboxylic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid or tetrahydrophthalic acid. Reboxylic acid is preferred. Examples of the diols include ethylene glycol, propylene glycol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,3-butanediol, Pentanediol, 1,6-hexanediol, dipropylene glycol, dibutylene glycol, 2-methyl-1,3-pentanediol, 2,2,4-trimethyl- Hexane dimethanol and the like, and the above-mentioned glycols are preferable. Examples of the diisocyanate include isophorone diisocyanate (IPDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), xylene diisocyanate, Isocyanate, naphthalene diisocyanate, 2,4-toluene diisocyanate or 2,6-toluene diisocyanate, and aromatic, alicyclic or aliphatic diisocyanates are preferred. The weight average molecular weight of the polyester urethane resin is not particularly limited, but is preferably 10,000 g / mol to 200,000 g / mol, more preferably 50,000 g / mol to 100,000 g / mol. .

The binder resin may be used alone, but preferably two or more resins having different weight average molecular weights may be used together. When two or more kinds of resins having different weight average molecular weights are used together, there is a problem that the physical properties of the film produced when only a binder having a large molecular weight is used are too hard and the problem that a film formed when only a binder having a small molecular weight is used is difficult . In addition, as compared with the case where a binder having a medium molecular weight is used alone, the binder having a different molecular weight has an advantage of being able to form a film having better physical properties by complementary action.

According to one aspect of the present invention, a resin composition comprising an acrylonitrile butadiene rubber resin and a phenoxy resin can more preferably be used as the binder resin.

When a resin containing an acrylonitrile-butadiene rubber resin and a phenoxy resin is used, the acrylonitrile-butadiene rubber resin is preferably added in an amount of 5 to 50 parts by weight, more preferably 5 to 50 parts by weight, 15 to 50 parts by weight of the phenoxy resin may be used, and 50 to 95 parts by weight, preferably 50 to 85 parts by weight of the phenoxy resin may be used. Excellent film forming ability and adhesion can be obtained within the above range.

The binder resin may be contained in an amount of 20 to 80% by weight, more preferably 20 to 70% by weight, and more preferably 20 to 60% by weight in the anisotropic conductive film. . Excellent film forming ability and adhesion can be obtained within the above range.

Radical Polymerizable  matter

The radical polymerizable material may include at least one of a urethane (meth) acrylate resin, a polyfunctional polyester (meth) acrylate resin, and a monomer having at least one (meth) acrylate reactive group in the molecule.

The monomer having at least one (meth) acrylate reactive group in the molecule is at least one monomer selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n- lauryl (meth) acrylates, C ₁₂ -C ₁₅ alkyl (meth) acrylate, n- stearyl (Meth) acrylate, methoxypolyethylene glycol (meth) acrylate, n-butoxyethyl (meth) acrylate, butoxy ethyleneglycol (meth) acrylate, methoxy triethylene glycol (Meth) acrylate, isobornyl (meth) acrylate, tetrahydroperfuryl (meth) acrylate, benzyl (meth) acrylate, Acrylate, 2-hydroxypropyl (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, dimethylaminoethyl (Meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethylhexahydrophthalate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, glycidyl (Meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,4-butanediol di Butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9- Diol di (meth) acrylate, glycerin di (meth) acrylate, (Meth) acrylate such as 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, dimethyloltricyclodecanediol (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorooctylethyl Bis (meth) acrylate modified with di (meth) acrylate of propylene oxide, bisphenol A modified with di (meth) acrylate of ethylene oxide, trimethylolpropane-benzoate- Acrylate, di (meth) acrylate of bisphenol A diglycidyl, or a reaction product of 2-hydroxy-3-phenoxypropyl (meth) acrylate and toluene diisocyanate. These may be used alone or in combination of two or more.

Preferably, the radically polymerizable material may comprise a mixture of a urethane (meth) acrylate resin, a polyfunctional polyester (meth) acrylate resin. (Meth) acrylate resin: polyfunctional polyester (meth) acrylate resin is contained in an amount of 50 wt% to 90 wt%: 10 wt% to 50 wt%, preferably 50 wt% to 70 wt%: 30 By weight to 50% by weight.

The radical polymerizable material may be contained in an amount of 10% by weight to 70% by weight, preferably 20% by weight to 65% by weight, more preferably 30% by weight to 60% by weight in the anisotropic conductive film. Within the above range, the entire cured product can sufficiently form an acrylate curing structure, and the hardness of the cured product can be prevented from becoming too high, thereby preventing deterioration of the interfacial peeling force and adhesion.

Hardener

The curing agent uses a curing agent that generates radicals by heat or light.

As the hardener, an organic peroxide can be used. The organic peroxide is selected from the group consisting of t-butyl peroxylaurate, 1,1,3,3-t-methylbutylperoxy-2-ethylhexanonate, 2,5-dimethyl- 2-ethylhexanoate, 2,5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxy T-butyl peroxybenzoate, t-butyl peroxyacetate, dicumyl peroxide, 2,5, -dimethyl-2,5-di (t-butylperoxy) hexane, t-butyl cumyl peroxide, t-hexyl peroxyneodecanoate, t-hexyl peroxy-2-ethyl hexanonate, Butyl peroxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy- Trimethyl hexanoate, t-butyl peroxy pivalate, cue Peroxyneodecanoate, di-isopropylbenzene hydroperoxide, cumene hydroperoxide, isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide But are not limited to, peroxide, oxides, lauroyl peroxide, stearoyl peroxide, succin peroxide, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxytoluene, 1,1,3,3- Peroxyneodecanoate, 1-cyclohexyl-1-methylethylperoxino edecanoate, di-n-propyl peroxydicarbonate, di-isopropyl peroxycarbonate, bis (4-t- Di (2-ethylhexyl peroxy) dicarbonate, dimethoxybutyl peroxy dicarbonate, di (3-methyl-3-methoxy Butyl peroxy) dicarbonate, 1 (T-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1- (T-butylperoxy) decane, t-butyltrimethylsilyl peroxide, bis (t-butylperoxy) cyclododecane, 2,2- (T-butyl) dimethylsilyl peroxide, t-butyltriallyl silyl peroxide, bis (t-butyl) diallylsilyl peroxide, tris Or a mixture of two or more of them may be used. Preferably, it may be, but is not limited to, lauroyl peroxide, benzoyl peroxide, isobutyl peroxide.

The curing agent may be included in the anisotropic conductive film in an amount of 0.5 to 10% by weight, specifically 1 to 8% by weight, and more specifically 2 to 7% by weight . Within the above range, the property of curing in the adhesive and the preservability of the adhesive can be balanced.

The anisotropic conductive film may further include a dispersant.

The dispersing agent can increase the haze of the anisotropic conductive film by well dispersing the inorganic particles and / or the conductive particles. Particularly, the dispersant enhances the dispersibility of the inorganic particles surface-treated with the silane coupling agent to increase the haze. The dispersing agent may be a conventional dispersing agent known to those skilled in the art, for example, BYK 165 or the like. The dispersing agent may include 1 to 10% by weight of the anisotropic conductive film, specifically 2 to 7% by weight. It is possible to increase the haze by dispersing the inorganic particles within the above range, and to improve the reliability of the connection resistance and the adhesive force.

The anisotropic conductive film was peeled at 90 DEG C for 5 hours at 85 DEG C and 85% relative humidity and peel strength adhesive strength (B, unit: gf / cm) measured after compression at 180 DEG C, 4 MPa and 5 seconds The adhesive strength reduction ratio according to the following formula 1 may be 30% or less, preferably 20% or less, with respect to the 90-degree peel strength adhesion (A, unit: gf / cm) measured by the same method.

<Formula 1>

Adhesion reduction ratio = | A - B | / B x 100

In the formula (1), A and B may be 600 gf / cm or more, preferably 600 gf / cm to 1000 gf / cm, respectively.

The anisotropically conductive film was measured for connection resistance (D, unit: Ω) measured after compression at 180 ° C., 4 MPa and 5 seconds and connection resistance (D) measured in the same manner after left at 85 ° C. and 85% C, unit:?), The connection resistance increase ratio according to the following formula 2 may be 100% or less, preferably 50% or less.

<Formula 2>

Connection resistance increase ratio = | C - D | / D x 100

In the equation (2), D may be 2 Ω or less, preferably 0.5 Ω to 1.5 Ω. In the expression (2), C may be 4? Or less, preferably 1? To 3 ?.

The anisotropic conductive film can be produced by applying a composition for anisotropic conductive films containing the above-described components onto a release film to a suitable thickness and drying for a certain period of time.

The thickness of the anisotropically conductive film is as thin as 0.1 to 10 mu m, preferably 1 to 5 mu m. And can be used in an optical display device in the above range.

The circuit connection structure of the present invention may include a wiring board, an anisotropic conductive film of the present invention mounted on the wiring board, and a chip mounted on the anisotropic conductive film.

The display device of the present invention includes the anisotropic conductive film or circuit connection structure of the present invention, and may include, for example, a liquid crystal display device or the like.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples.

The composition of the inorganic particles used in Examples and Comparative Examples is shown in Table 1 below.

Inorganic particle Inorganic particle
A Inorganic particle
B Inorganic particle
C Inorganic particle
D Inorganic particle
E Average particle diameter (占 퐉) D10 0.2 0.3 0.4 0.8 One D50 0.8 0.7 One 1.7 2 D90 1.5 2.2 2.7 3.2 4.5

The composition of the conductive particles used in Examples and Comparative Examples is shown in Table 2 below.

Conductive particle Conductive particle
A Conductive particle
B Conductive particle
C Conductive particle
D Conductive particle
E Average particle diameter (占 퐉) D10 0.3 0.5 0.8 1.3 1.9 D50 3.1 3.6 3.9 4.6 4.8 D90 4.9 5.9 6.2 6.6 6.9

Example  One

As the binder resin serving as a matrix for film formation, 25 parts by weight of a phenoxy resin (PKHH, Inchemrez, USA) dissolved in ethyl acetate at 20% by volume, 5 parts by weight of acrylonitrile butadiene rubber resin (NBR, ZEON) 25 parts by weight of a urethane-based acrylic resin (UA340P, Shin-Nakamura), 25 parts by weight of a polyfunctional polyester acrylic resin (PS610, Miwon), 5 parts by weight of a urethane-based acrylic resin (EB220, Skcytec) 5 parts by weight of a mixture of BPO (Sigma-aldrich) and LPO (Sigma-aldrich) as a thermosetting radical curing agent, 5 parts by weight of conductive particles A as conductive particles as fillers for imparting conductivity to the anisotropic conductive film, A were mixed to prepare a composition for anisotropic conductive films. The composition for anisotropic conductive films prepared as described above was coated on a white release film, and the solvent was evaporated for 5 minutes in a drier at 70 ° C to obtain a dried anisotropic conductive film having a thickness of 4 μm.

Example  2 to Example 4

An anisotropic conductive film was obtained in the same manner as in Example 1, except that the content of each component, the kind of conductive particles and the kind of inorganic particles were changed as shown in Table 3 (unit: parts by weight).

Comparative Example  1 to Comparative Example  2

An anisotropic conductive film was obtained in the same manner as in Example 1, except that the content of each component, the kind of conductive particles, and the kind of inorganic particles were changed as shown in Table 3 below.

product name Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 bookbinder
Suzy NBR 5 5 5 5 5 5 PKHH 20 25 25 25 25 20 Radical polymerizable
matter EB220 10 5 5 5 5 5 UA340P 25 25 25 25 25 20 PS610 25 25 25 25 25 20 Hardener BPO 3 3 3 3 3 3 LPO 2 2 2 2 2 2 Conductive particle Kinds D E A B C A content 5 5 5 5 5 5 Inorganic particle Kinds D E A B C A content 5 5 5 5 5 20

The following properties of the anisotropic conductive films prepared in Examples and Comparative Examples were evaluated, and the results are shown in Table 4 below.

(1) Haze and total light transmittance: The anisotropic conductive films of Examples and Comparative Examples were sampled with a length x width (2 cm x 5 cm) and placed on a slide glass. Leave in the oven for 1 minute at 40 ° C to make the white release film peel off as much as possible. Put the specimen into a filmetrics F10-RT and measure the haze and total light transmittance.

 (2) Connection resistance: A glass substrate having an interval of 50 占 퐉 pitch and an indium tin oxide (ITO) circuit having a thickness of 2000 占 and a 50 占 퐉 pitch COF were squeezed between the upper and lower interfaces with the anisotropic conductive films of Examples and Comparative Examples Thereafter, the sample was heated under pressure of 180 MPa at 4 MPa for 5 seconds to prepare five specimens per sample. The connection resistance was measured by the 4-terminal measurement method.

As a reliability evaluation, the anisotropically conductive film having the connection resistance measurement completed was placed in a high temperature and high humidity environment at 85 캜 and 85% relative humidity, and left for 250 hours and 500 hours, respectively, and then the connection resistance was measured in the same manner as described above.

(3) Adhesion force: In order to determine the adhesion properties of the anisotropic conductive film to the substrate, the anisotropic conductive film prepared above was subjected to a top-to-bottom interface with a 2000 Å thick indium tin oxide (ITO) glass substrate and 50 pitch COF After pressing, the specimens were pressed under a pressure of 4 MPa at a temperature of 180 ° C for 5 seconds to prepare five specimens per sample. The 90 degree peel strength was measured using Shimadzu UTM.

As an evaluation of reliability, the anisotropic conductive film having the above adhesive force measurement was put into high temperature and high humidity at 85 캜 and 85% relative humidity, and left for 250 hours and 500 hours, respectively, and the adhesive force was measured in the same manner as above.

(4) Evaluation of whether or not the film was press-fitted after press-bonding: The anisotropic conductive film was press-bonded under the condition of 1 MPa / 1 s using a presser, and then the release film was peeled off. The peeled specimen was observed with a microscope, Side peeling (lifting) of the adhered portion of the conductive film and the presence of an abnormality such as an intermediate bubble were confirmed.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Haze (%) 43 43 73 65 51 78 Total light transmittance (%) 51 51 22 27 37 20 Connection resistance
(Ω) Early 2.1 2.1 0.9 1.0 0.9 0.8 Reliability 250 hours 3.1 3.1 1.2 1.3 1.2 1.2 Reliability 500 hours 5.0 5.0 1.5 1.7 1.5 1.4 Adhesion
(gf / cm) Early 600 600 890 840 890 850 Reliability 250 hours 510 510 840 800 840 820 Reliability 500 hours 400 400 780 710 780 730 Evaluation of pressure bonding completion of film Lifting Lifting Good Good Good Good

As shown in Table 4, the anisotropic conductive film according to the present embodiment can easily confirm whether the pressure bonding is completed even if the haze is 50% or more and does not include a pigment such as a pigment or a dye. The anisotropic conductive film according to this example was excellent in adhesion and connection resistance after initial and reliability evaluation.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (14)

A thermosetting resin, a binder, a radical polymerizing substance, a curing agent, inorganic particles and conductive particles,
The anisotropic conductive film has a haze of 50% or more,
Wherein the inorganic particles have an average particle diameter (D10) of 0.1 占 퐉 or more and 0.5 占 퐉 or less,
Wherein the conductive particles have an average particle diameter (D10) of 0.1 占 퐉 or more and 1 占 퐉 or less.
The anisotropic conductive film according to claim 1, wherein the anisotropic conductive film has a haze of 50% or more and 90% or less.
The anisotropic conductive film according to claim 1, wherein the inorganic particles comprise spherical silica.
The anisotropic conductive film according to claim 1, wherein the inorganic particles are surface-treated with a silane compound.
The anisotropic conductive film according to claim 1, wherein the conductive particles comprise insulating particles.
The anisotropic conductive film according to claim 1, wherein the inorganic particles and the whole conductive particles are contained in an amount of 1 wt% to 50 wt% of the anisotropic conductive film.
The anisotropic conductive film of claim 1, wherein the binder resin comprises a mixture of an acrylonitrile butadiene rubber resin and a phenoxy resin.
The anisotropic conductive film of claim 1, wherein the radically polymerizable material comprises a mixture of a urethane (meth) acrylate resin and a polyfunctional polyester (meth) acrylate resin.
The anisotropically conductive film according to claim 1, wherein the anisotropic conductive film comprises 20 to 80% by weight of the binder, 10 to 70% by weight of the radical polymerizable substance, 0.5 to 10% by weight of the curing agent, 0.1% To 30% by weight of the conductive particles and 1% to 20% by weight of the conductive particles.
The anisotropic conductive film of claim 1, wherein the anisotropic conductive film further comprises a dispersing agent.
The anisotropically conductive film according to claim 1, wherein the anisotropic conductive film has an adhesive strength reduction ratio of 30%
<Formula 1>
Adhesion reduction ratio = | A - B | / B x 100
(In the formula 1, B is the peel strength adhesive force (unit: gf / cm) measured after pressing the anisotropic conductive film at 180 DEG C, 4 MPa and 5 seconds,
A is the 90 degree peel strength adhesive force (unit: gf / cm) measured by the same method as above after the anisotropic conductive film is allowed to stand at 85 DEG C and 85% relative humidity for 500 hours.
The anisotropic conductive film according to claim 1, wherein the anisotropic conductive film has a connection resistance increase ratio of 100%
<Formula 2>
Connection resistance increase ratio = | C - D | / D x 100
(In the above formula 2, D represents the connection resistance (unit: Ω) measured after the anisotropic conductive film is pressed at 180 ° C., 4 MPa and 5 seconds,
C is a connection resistance (unit: Ω) measured in the same manner as above after the anisotropic conductive film is allowed to stand at 85 ° C. and 85% relative humidity for 500 hours.
A connection structure comprising an anisotropic conductive film according to any one of claims 1 to 12.
A display device comprising an anisotropic conductive film according to any one of claims 1 to 12.