KR102584123B1 - Anisotropic conductive film and display device comprising the same - Google Patents

Abstract

An anisotropic conductive film comprising an inorganic filler and a hydrogenated bisphenol epoxy resin having a specific surface area of 150 m ² /g to 300 m ² /g, wherein the anisotropic conductive film has a maximum melt viscosity and a melt viscosity of 50° C. to 120° C. An anisotropic conductive film, wherein the minimum value difference is 500 Pa.s to 3000 Pa.s, and a display device including the same are provided.

Description

Anisotropic conductive film and display device comprising the same {ANISOTROPIC CONDUCTIVE FILM AND DISPLAY DEVICE COMPRISING THE SAME}

The present invention relates to an anisotropic conductive film and a display device including the same.

When the anisotropic conductive film is placed between circuit terminals to be connected and subjected to heating and pressurization under certain conditions, the circuit terminals are electrically connected by conductive particles, and adjacent electrodes are filled with insulating adhesive resin to become conductive. Insulation is provided by the particles existing independently of each other.

As display panels become thinner and have higher resolution, research has been conducted on techniques to capture the maximum amount of conductive particles in the minimum connection area. In order to improve the capture rate of conductive particles, methods of suppressing the flow of resin by increasing the density of conductive particles in an anisotropic conductive film or including an excessive amount of inorganic filler have been studied. However, this method has a problem in that there is no flow of resin and a short circuit may occur.

Meanwhile, as display panels have recently become flexible, anisotropic conductive films that can be applied to flexible panels are being studied. Flexible panels are made of polymer film. However, unlike conventional metal or glass plates, polymer films are weak to heat, soft, and flexible. Therefore, when connecting an anisotropic conductive film using a polymer film as an adherend, it is necessary to press at a low temperature in order to minimize the thermal stress of the polymer film. In addition, even when the anisotropic conductive film is pressed to the polymer film at the same temperature and pressure, there is a difference in the actual pressing temperature of the anisotropic conductive film depending on the pressing position in the polymer film. This difference in pressing temperature may cause the degree of pressing of the anisotropic conductive film to vary, resulting in non-uniform pressing. Therefore, there is a need for an anisotropic conductive film that can be compressed even at low temperatures and can prevent uneven compression even when a polymer film is used as the adherend.

The background technology of the present invention is disclosed in Japanese Patent Publication No. 2014-031444, etc.

The purpose of the present invention is to provide an anisotropic conductive film that can be compressed at low temperature and can be applied to a polymer film adherend.

Another object of the present invention is to provide an anisotropic conductive film having a low difference between the maximum and minimum melt viscosity in the section between the melting start temperature and the curing start temperature of the anisotropic conductive film.

Another object of the present invention is to provide an anisotropic conductive film that can eliminate uneven compression when applied to a polymer film adherend.

Another object of the present invention is to provide an anisotropic conductive film with a high particle capture rate of conductive particles and a high monodisperse rate of conductive particles.

Another object of the present invention is to provide an anisotropic conductive film with low connection resistance, excellent connection resistance reliability, and low insulation resistance.

One aspect of the present invention is an anisotropic conductive film.

1. The anisotropic conductive film includes an inorganic filler and a hydrogenated bisphenol epoxy resin with a specific surface area of 150 m ² /g to 300 m ² /g, and the anisotropic conductive film has a maximum melt viscosity and a melting point of 50° C. to 120° C. The difference in the minimum value of degrees is 500Pa.s to 3000Pa.s.

In 2.1, the anisotropic conductive film may include a conductive layer and an insulating layer.

In 3.1-2, the inorganic filler may be included in 1% to 20% by weight of the anisotropic conductive film.

In 4.1-3, the inorganic filler may have an average particle diameter of 5 nm to 20 nm.

5.1-4, the inorganic filler is silica, alumina, titania, zirconia, magnesia, ceria, zinc oxide, iron oxide, silicon nitride, titanium nitride, boron nitride, calcium carbonate, aluminum sulfate, aluminum hydroxide, calcium titanate, talc, calcium silicate. , and may contain one or more types of magnesium silicate.

In 6.1-5, the hydrogenated bisphenol epoxy resin may be included in an amount of 5% to 40% by weight of the anisotropic conductive film.

In 7.1-6, the anisotropic conductive film may have a conductive particle monodispersion rate of 90% or more.

In 8.1-7, the anisotropic conductive film may have a conductive particle capture rate of 80% or more.

In 9.1-8, the anisotropic conductive film is placed between the first connected member and the second connected member, and temporarily pressed under the conditions of 60°C to 80°C, 0.5 second to 1 second, and 0.5 to 1.0 MPa pressure; And when main compression is performed under conditions of 140°C to 160°C, 5 to 7 seconds, and 50 to 90 MPa pressure, the connection resistance may be 3Ω or less.

In 10.1-9, the anisotropic conductive film is placed between the first connected member and the second connected member, and is temporarily pressed under the conditions of 60°C to 80°C, 0.5 second to 1 second, and 0.5 to 1.0 MPa pressure; and after main compression under conditions of 140°C to 160°C, 5 to 7 seconds and 50 to 90 MPa pressure, and then left for 100 hours under conditions of 85°C and 85% relative humidity, the connection resistance after reliability measured may be 6Ω or less. there is.

11.1-10, the anisotropic conductive film may have a modulus of 2.0 GPa or more at 30°C.

12.2-11, the insulating layer may include the hydrogenated bisphenol epoxy resin, an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g, a binder resin, and a curing agent.

In 13.12, the binder resin may include a biphenyl fluorene type phenoxy resin.

In 14.12, in the insulating layer, 20% to 40% by weight of the hydrogenated bisphenol epoxy resin, 10% to 40% by weight of the inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g, and the binder resin 20 It may contain % to 55% by weight and 1% to 5% by weight of the curing agent.

15.2-14, the conductive layer may include a binder resin, an epoxy resin, a curing agent, and conductive particles.

In 16.15, the binder resin may include a biphenyl fluorene type phenoxy resin.

In 17.15, in the conductive layer, 20% to 55% by weight of the binder resin, 20% to 40% by weight of the epoxy resin, 1% to 5% by weight of the curing agent, and 20% to 50% by weight of the conductive particles. may include.

The display device of the present invention includes the anisotropic conductive film of the present invention.

The display device of the present invention is connected by the anisotropic conductive film of the present invention.

The present invention provides an anisotropic conductive film that can be compressed at low temperatures and can be applied to a polymer film adherend.

The present invention provides an anisotropic conductive film with a low difference between the maximum and minimum melt viscosity in the section between the melting start temperature and the curing start temperature of the anisotropic conductive film.

The present invention provides an anisotropic conductive film that can eliminate uneven compression when applied to a polymer film adherend.

The present invention provides an anisotropic conductive film with a high particle capture rate of conductive particles and a high monodisperse rate of conductive particles.

The present invention provides an anisotropic conductive film with low connection resistance, excellent connection resistance reliability, and low insulation resistance.

Figure 1 shows the melt viscosity according to temperature when compressing the anisotropic conductive film of Example 2 (marked with red ○ in Fig. 1) and Comparative Example 1 (marked with blue □ in Fig. 1).

The present invention will be described in more detail by way of exemplary embodiments of the present invention. However, the technology disclosed in this application is not limited to the embodiments described herein and may be embodied in other forms. However, the embodiments introduced here are provided to ensure that the disclosed content is thorough and complete and that the spirit of the present application can be sufficiently conveyed to those skilled in the art.

In this specification, the “specific surface area” of the inorganic filler is a value measured by the BET (Brunauer Emmett Teller) surface area analysis method. Specific surface area refers to the area per unit volume of the inorganic filler.

In this specification, “average particle diameter” means D50. D50 measures the particle size of particles and When a cumulative mass curve is drawn, the passing mass percentage refers to the particle size corresponding to 50% by weight. The particle size of the particles can be measured using a particle size analyzer, but is not limited thereto.

As used herein, “modulus” means storage modulus.

In this specification, when describing a numerical range, X to Y means more than X and less than Y (X≤ and ≤Y).

The inventor of the present invention found that by including an inorganic filler having a specific specific surface area and hydrogenated bisphenol epoxy resin as the epoxy resin, the anisotropic conductive film can be compressed at low temperature, and the melting start temperature and the curing start temperature of the anisotropic conductive film are The present invention was completed after confirming that the deviation of melt viscosity in the section was lowered, thereby eliminating the unevenness of compression during compression in the polymer film, and increasing the capture rate and monodisperse rate of conductive particles.

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

The anisotropic conductive film includes an inorganic filler and a hydrogenated bisphenol epoxy resin with a specific surface area of 150 m ² /g to 300 m ² /g, and the anisotropic conductive film has a maximum melt viscosity and a melt viscosity of 50° C. to 120° C. The difference in minimum value is 500Pa.s to 3000Pa.s. In the above specific surface area range, the deviation of melt viscosity between the melting start temperature and the curing start temperature is lowered, so that compression unevenness during compression in the polymer film can be resolved, and the capture rate and monodisperse rate of conductive particles can be increased. Preferably, the specific surface area may be 180m ² /g to 290m ² /g, 190m ² /g to 290m ² /g, or 200m ² /g to 290m ² /g. The “50°C” may be the melting onset temperature. The “120°C” may be the curing start temperature.

The difference between the maximum value of melt viscosity and the minimum value of melt viscosity at 50°C to 120°C is 500 Pa.s to 3000 Pa.s, thereby eliminating compression unevenness during compression in the polymer film. Preferably, the difference in melt viscosity at 50°C to 120°C may be 500 Pa.s to 2500 Pa.s. More preferably, the difference in melt viscosity at 50°C to 120°C may be 500 Pa.s to 1000 Pa.s.

The anisotropic conductive film has a melt viscosity at 50°C to 120°C of 200Pa.s to 10000Pa.s, preferably 200Pa.s to 5000Pa.s, 200Pa.s to 1500Pa.s, preferably 300Pa.s to 1000Pa.s. This can be. In the above range, there may be a high capture rate and high dispersion rate effect. The inorganic filler is included in the anisotropic conductive film and can control the melt viscosity of the anisotropic conductive film when compressed. The inorganic filler can ensure a difference in melt viscosity of 500 Pa.s to 3000 Pa.s by having a specific surface area of 150 m ² /g to 300 m ² /g. Even if an anisotropic conductive film includes hydrogenated bisphenol epoxy resin as an epoxy resin, if it contains an inorganic filler having a specific surface area other than the above-mentioned specific surface area range, the melt viscosity difference of 500 Pa.s to 3000 Pa.s can be secured. does not exist. In the present invention, by controlling the specific surface area of the inorganic filler and using hydrogenated epoxy resin, it was possible to reduce the difference in melt viscosity of the anisotropic conductive film in the range between the melting start temperature and the curing start temperature of the anisotropic conductive film.

The inorganic filler may be included in an amount of 1% to 20% by weight, preferably 5% to 10% by weight, in the anisotropic conductive film. Within the above range, an appropriate melt viscosity of the anisotropic conductive film is secured to ensure insulation in the surface direction when compressed, and there may be no problem of short circuit occurring due to too low flowability when compressed of the anisotropic conductive film.

The inorganic filler may have an average particle diameter of 5 nm to 20 nm, preferably 7 nm to 15 nm. Within the above range, the coating properties of the composition for an anisotropic conductive film can be improved to improve film formability, and the particle capture rate and monodispersity of the conductive particles can be improved. The anisotropic conductive film may include inorganic fillers having the same average particle diameter, or may include two or more types of inorganic fillers having different average particle diameters.

The inorganic filler is not particularly limited and may include inorganic fillers commonly used in the art. For example, inorganic fillers include silica, alumina, titania, zirconia, magnesia, ceria, zinc oxide, iron oxide, silicon nitride, titanium nitride, boron nitride, calcium carbonate, aluminum sulfate, aluminum hydroxide, calcium titanate, talc, calcium silicate, and silicic acid. One or more types of magnesium may be used. Specifically, the inorganic filler may include silica.

The inorganic filler may be an inorganic filler that is not surface treated, but the dispersibility of the inorganic filler in the anisotropic conductive film can be improved by using a surface treated inorganic filler. Surface treatment may mean surface treatment with compounds such as phenylamino group, phenyl group, methacryl group, vinyl group, and epoxy. The method of surface treating the inorganic filler is not particularly limited. For example, the surface can be treated by mixing an inorganic filler and a surface treatment material, or in some cases, by a dry method.

In one embodiment, the inorganic filler may include a non-porous inorganic filler.

The hydrogenated bisphenol epoxy resin is included in the anisotropic conductive film and can facilitate control of the melt viscosity of the anisotropic conductive film when mixed with an inorganic filler having the above specific surface area range and can be cured at low temperatures. You can ensure the difference. Even if an inorganic filler having the above-described specific surface area range is included in the anisotropic conductive film, if an epoxy resin other than hydrogenated bisphenol epoxy resin is included, the difference in melt viscosity of the present invention cannot be secured.

The hydrogenated bisphenol epoxy resin may include an epoxy resin prepared by hydrogenating a bisphenol epoxy resin. Bisphenol epoxy resins used for hydrogenation may include, but are not limited to, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, etc. Preferably, hydrogenated bisphenol A epoxy resin can be used. The hydrogenated bisphenol epoxy resin may be a commercially available product, such as YX8000 (Mitsubishi Chemical, hydrogenated bisphenol A epoxy resin), but is not limited thereto.

The hydrogenated bisphenol epoxy resin may be included in an amount of 5% to 40% by weight, preferably 10% to 15% by weight, in the anisotropic conductive film. Within the above range, the difference in melt viscosity of the present invention can be secured, and the effects of high capture rate and high dispersion rate can be achieved.

The anisotropic conductive film may contain conductive particles in an amount of 20% to 50% by weight, preferably 25% to 35% by weight. Within the above range, conductive particles can be easily compressed between terminals to ensure stable connection reliability, and connection resistance can be reduced by improving conductivity.

The anisotropic conductive film may have a thickness of 5㎛ to 25㎛, preferably 5㎛ to 20㎛. Within the above range, it can be used for connections and can be used for display devices.

The anisotropic conductive film may have a conductive particle monodispersion ratio of 90% or more, preferably 90% to 100%. In the above range, the fluidity of the anisotropic conductive film may decrease when compressed, and connection reliability may be excellent. Monodisperse is defined as a state in which conductive particles in an anisotropic conductive film are spaced apart from other adjacent conductive particles. The conductive particle monodispersity rate can be measured using an Image Analysis method, but is not limited thereto.

The anisotropic conductive film may have a conductive particle capture rate of 80% or more, preferably 84% to 100%. Within the above range, when applied to a high-resolution device, connection resistance reliability is excellent and there may be no problem with insulation resistance.

The capture rate of conductive particles is expressed as a percentage of the number of conductive particles on the terminal before and after compression, and non-limiting examples of measuring this are as follows: the number of conductive particles on the terminal before compression (the number of conductive particles before compression) number) is calculated by equation 1 below.

[Equation 1]

Number of conductive particles before compression = Particle density of conductive particles in the conductive layer (piece/mm ² ) Area of Х terminal (mm ² )

Additionally, the number of conductive particles on the terminal after compression (the number of conductive particles after compression) is counted and measured using a metallographic microscope, and then the particle capture rate of the conductive particles is calculated using Equation 2 below.

[Equation 2]

Particle capture rate = (Number of conductive particles after compression/Number of conductive particles before compression) Х 100(%)

The conditions for the temporary compression and main compression are as follows:

1) Temporary compression conditions: 60℃, 1 second, 1.0MPa

2) Main compression conditions: 150℃, 5 seconds, 70MPa

The anisotropic conductive film may have a monodisperse rate of conductive particles of 90% or more, preferably 95% to 100%. In the above range, there may be a high capture rate and high dispersion rate effect.

The anisotropic conductive film is placed between the first connected member and the second connected member, and is temporarily pressed under the conditions of 60°C to 80°C, 0.5 second to 1 second, and 0.5 MPa to 1.0 MPa pressure; And when main compression is performed under conditions of 140°C to 160°C, 5 to 7 seconds, and 50MPa to 90MPa pressure, the connection resistance may be 3Ω or less, preferably 0Ω or more and less than 3Ω. Within the above range, connection reliability can be improved.

The anisotropic conductive film is placed between the first connected member and the second connected member, and is temporarily pressed under the conditions of 60°C to 80°C, 0.5 second to 1 second, and 0.5 MPa to 1.0 MPa pressure; and after main compression under conditions of 140°C to 160°C, 5 to 7 seconds and 50MPa to 90MPa pressure, and then left for 100 hours under conditions of 85°C and 85% relative humidity, the connection resistance after reliability measured is 6Ω or less, Preferably, it may be 0Ω or more and less than 6Ω. Within the above range, low connection resistance can be maintained even under high temperature and high humidity conditions, thereby improving connection reliability.

The connection resistance after reliability refers to the connection resistance after being left for 100 hours under conditions of 85°C and 85% relative humidity after the above-mentioned temporary compression and main compression. The method of measuring the connection resistance after the reliability is not particularly limited and can be measured according to a method commonly used in the technical field. A non-limiting example of a method for measuring connection resistance after reliability is as follows: After pre-pressing and main-pressing a plurality of film specimens, leaving them for 100 hours under conditions of a temperature of 85°C and a relative humidity of 85%, and then testing Measure each connection resistance by applying a current of 1 mA (using Keithley 2000 Multimeter, 4-probe method) and then calculating the average value.

The conditions for the temporary compression and main compression are as follows:

1) Temporary compression conditions: 60℃, 1 second, 1.0MPa

2) Main compression conditions: 150℃, 5 seconds, 70MPa

In the above range, conductive particles are sufficiently located on the terminals, thereby improving conductivity and reducing leakage of conductive particles into the space, thereby reducing short circuits between terminals.

The anisotropic conductive film may have a cure rate of 85% or more, preferably 85% to 100%. In the above range, the fluidity of the anisotropic conductive film may decrease when compressed, and connection reliability may be excellent.

The curing rate of the anisotropic conductive film is measured using Equation 3 below.

[Equation 3]

Hardening rate (%) = [(H ₀ -H ₁ )/H ₀ ]Х100

In Equation 3, H ₀ is the area under the curve of an anisotropic conductive film in a temperature range of -50°C to 250°C at 10°C/min under a nitrogen gas atmosphere using DSC (thermal differential scanning calorimeter, TA instruments, Q20). This is the measured initial calorific value, and H ₁ represents the calorific value measured in the same manner after leaving the plate on a hot plate at 130°C for 5 seconds).

The anisotropic conductive film was cut into 2mm*25mm and bonded to each insulation resistance evaluation material for evaluation. At this time, 60℃, 1MPa, The laminate of the anisotropic conductive film and PET (polyethylene terephthalate) film was pressurized by heating/pressing under 1 sec conditions, the PET film was peeled off, and the anisotropic conductive film was placed on the glass substrate. Next, the chips (chip length 19.5 mm, chip width 1.5 mm, bump spacing 8 μm) were aligned and placed, and then main compression was performed under the conditions of 150°C, 70 MPa, and 5 sec. Here, 50V was applied and a total of 38 points were tested for short circuits using the two-terminal method. As a result, the anisotropic conductive film did not generate insulation resistance.

The anisotropic conductive film may have a modulus of 2.0 GPa or more at 30°C, for example, 2.0 GPa to 4.0 GPa, or 2.5 GPa to 3.5 GPa. Within the above range, the particle capture rate of the anisotropic conductive film may be excellent.

The anisotropic conductive film may be composed of only a conductive layer containing conductive particles, but may further include an insulating layer to solve problems such as tearing of the conductive layer or poor flow during connection.

In one embodiment, the anisotropic conductive film may include a conductive layer and an insulating layer formed on one surface of the conductive layer. The insulating layer may include an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g and a hydrogenated bisphenol epoxy resin as an epoxy resin. Therefore, the anisotropic conductive film can secure the difference in melt viscosity and increase the capture rate and monodisperse rate of conductive particles. The insulating layer contains only hydrogenated bisphenol epoxy resin as an epoxy resin and does not contain any other epoxy resin other than hydrogenated bisphenol epoxy resin.

In another embodiment, the anisotropic conductive film may include a conductive layer and an insulating layer formed on both sides of the conductive layer. One or more of the insulating layers may include an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g and a hydrogenated bisphenol epoxy resin as an epoxy resin. Therefore, the anisotropic conductive film can secure the difference in melt viscosity and increase the capture rate and monodisperse rate of conductive particles. The insulating layer contains only hydrogenated bisphenol epoxy resin as an epoxy resin and does not contain any other epoxy resin other than hydrogenated bisphenol epoxy resin.

Hereinafter, the insulating layer and the conductive layer will be described in detail.

The insulating layer may include a hydrogenated bisphenol epoxy resin, an inorganic filler with a specific surface area of 150 m ² /g to 300 m ² /g, a binder resin, and a curing agent.

The hydrogenated bisphenol epoxy resin and the inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g are as described above. In one embodiment, the insulating layer includes only hydrogenated bisphenol epoxy resin as the epoxy resin and does not include any epoxy resin other than the hydrogenated bisphenol epoxy resin.

The hydrogenated bisphenol epoxy resin may be included in an amount of 20% to 40% by weight, preferably 25% to 35% by weight, in the insulating layer. Within the above range, there may be an effect of capturing rate of conductive particles and high dispersion rate.

The inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g may be included in the insulating layer in an amount of 10% to 40% by weight, preferably 15% to 25% by weight. In the above range, there may be an effect of particle capture rate and high single dispersion rate.

Binder resins include phenoxy resin, polyimide resin, polyamide resin, polymethacrylate resin, polyacrylate resin, polyurethane resin, polyester resin, polyester urethane resin, polyvinyl butyral resin, and styrene-butyrene. -Styrene resin, epoxy modified product of styrene-butylene-styrene resin, styrene-ethylene-butylene-styrene resin, epoxy modified product of styrene-ethylene-butylene-styrene resin, acrylonitrile It may contain one or more types of hydrogenated forms of butadiene rubber and acrylonitrile butadiene rubber. Preferably, a phenoxy resin can be used as the binder resin, more preferably a fluorene-type phenoxy resin, and even more preferably a biphenyl fluorene-type phenoxy resin. By using biphenyl fluorene type phenoxy resin as a binder resin, the particle capture rate and high monodispersion rate effects can be further improved.

The binder resin may be included in an amount of 20% to 55% by weight, preferably 30% to 50% by weight, in the insulating layer. Within the above range, particle capture rate and high dispersion rate effects can be obtained.

The curing agent is not particularly limited as long as it can form an insulating layer by curing the binder resin or hydrogenated bisphenol epoxy resin. The curing agent may be, for example, an acid anhydride-based, amine-based, imidazole-based, isocyanate-based, amide-based, hydrazide-based, phenol-based, sulfonium-based or other cationic type.

The curing agent may be included in 1% to 5% by weight of the insulating layer, preferably 2% to 4% by weight. Within the above range, sufficient reaction required for curing can occur and excellent adhesion and reliability after bonding can be achieved.

The insulating layer may further include a silane coupling agent, additives, etc. in addition to the hydrogenated bisphenol epoxy resin, an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g, a binder resin, and a curing agent.

Silane coupling agents can increase the adhesion of anisotropic conductive films. Silane coupling agents include silicon compounds containing polymerizable unsaturated groups such as vinyltrimethoxysilane, vinyltriethoxysilane, and (meth)acryloxypropyltrimethoxysilane; epoxy group-containing silicon compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; -Amino group-containing silicon compounds such as aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; It may contain one or more types of 3-chloropropyltrimethoxysilane.

The silane coupling agent may be included in an amount of 0.5% to 5% by weight, preferably 1% to 3% by weight, in the insulating layer. Within the above range, there may be an effect of improving the adhesion of the anisotropic conductive film.

Additives may include conventional additives known to those skilled in the art, such as polymerization inhibitors, antioxidants, and heat stabilizers. The additive may be included in an amount of 0.5% to 5% by weight, preferably 1% to 3% by weight, in the insulating layer. Within the above range, the effect as an additive can be obtained without affecting the effect of the anisotropic conductive film of the present invention.

The insulating layer may have a thickness of 5㎛ to 20㎛, preferably 5㎛ to 15㎛. Within the above range, it can be used for connections and can be used for display devices.

The conductive layer may include a binder resin, epoxy resin, hardener, and conductive particles.

The binder resin forms the matrix of the conductive layer. Binder resins include phenoxy resin, polyimide resin, polyamide resin, polymethacrylate resin, polyacrylate resin, polyurethane resin, polyester resin, polyester urethane resin, polyvinyl butyral resin, and styrene-butyrene. -Styrene resin, epoxy modified product of styrene-butylene-styrene resin, styrene-ethylene-butylene-styrene resin, epoxy modified product of styrene-ethylene-butylene-styrene resin, acrylonitrile It may contain one or more types of hydrogenated forms of butadiene rubber and acrylonitrile butadiene rubber. Preferably, phenoxy resin can be used as the binder resin. More preferably, the binder resin may be a mixture of fluorene type phenoxy resin and non-fluorene type phenoxy resin. Most preferably, the binder resin may be a mixture of a non-fluorene type phenoxy resin and a biphenyl fluorene type phenoxy resin. By using the above mixture as a binder resin, particle capture rate and high dispersion rate effects can be achieved.

The binder resin may be included in an amount of 20% to 55% by weight, preferably 30% to 50% by weight, of the conductive layer. Within the above range, particle capture rate and high dispersion rate effects can be obtained.

In one embodiment, the anisotropic conductive film may include a biphenyl fluorene-type phenoxy resin in at least one of the insulating layer and the conductive layer, preferably in both the insulating layer and the conductive layer. The biphenyl fluorene type phenoxy resin may be included in an amount of 20% to 55% by weight, preferably 30% to 50% by weight, in the anisotropic conductive film.

Epoxy resin can increase the adhesion of the conductive layer. Epoxy resins include bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, bisphenol A-type epoxy acrylate resin, bisphenol F-type epoxy resin, bisphenol AD-type epoxy resin, bisphenol E-type epoxy resin, and bisphenol S-type epoxy resin; Aromatic epoxy resins such as polyglycidyl ether epoxy resin, polyglycidyl ester epoxy resin, and naphthalene epoxy resin; Alicyclic epoxy resin; Novolak-type epoxy resins such as cresol novolak-type epoxy resins and phenol novolak-type epoxy resins; Glycidyl amine-based epoxy resin; Glycidyl ester-based epoxy resin; Epoxy resins such as biphenyl diglycidyl epoxy resin can be used, but are not limited thereto. Preferably, the epoxy resin may include dicyclopentadiene epoxy resin. Dicyclopentadiene epoxy resin can provide particle capture rate and high dispersion rate effects.

In one embodiment, the conductive layer is an epoxy resin and may not include hydrogenated bisphenol epoxy resin.

The epoxy resin may be included in 20% to 40% by weight of the conductive layer, preferably 20% to 35% by weight. Within the above range, particle capture rate and high dispersion rate effects can be obtained.

The conductive particles may be conductive particles commonly used in the technical field. Non-limiting examples of conductive particles include metal particles including Au, Ag, Ni, Cu, solder, etc.; carbon; Particles made by plating and coating a resin containing polyethylene, polypropylene, polyester, polystyrene, polyvinyl alcohol, etc. and a modified resin thereof with a metal containing Au, Ag, Ni, etc.; Examples include insulating conductive particles coated with insulating particles additionally thereon. These may be used alone or in combination of two or more types.

The conductive particles may have an average particle diameter of 2.5 ㎛ to 5.5 ㎛, preferably 3.0 ㎛ to 3.5 ㎛. Within the above range, it can be used for connections and can be used for display devices.

Conductive particles may be included in 20% to 50% by weight of the conductive layer, preferably 20% to 35% by weight, and more preferably 25% to 35% by weight. Within the above range, conductive particles can be easily compressed between terminals to ensure stable connection reliability, and connection resistance can be reduced by improving conductivity.

The curing agent is not particularly limited as long as it can form an insulating layer by curing the binder resin or epoxy resin. The curing agent may be, for example, an acid anhydride-based, amine-based, imidazole-based, isocyanate-based, amide-based, hydrazide-based, phenol-based, sulfonium-based or other cationic type.

The curing agent may be included in an amount of 1% to 5% by weight, preferably 1% to 4% by weight, in the conductive layer. Within the above range, sufficient reaction required for curing can occur and excellent adhesion and reliability after bonding can be achieved.

In one embodiment, the conductive layer may not include an inorganic filler.

In other embodiments, the conductive layer may further include an inorganic filler. A high capture rate effect can also be provided by further including an inorganic filler in the conductive layer. The inorganic filler may be included in an amount of 3% by weight or less, preferably 0% by weight or more and 1% by weight or less, in the conductive layer. The inorganic filler may have the above-described specific surface area range or may include an inorganic filler having a specific surface area range other than the above-described specific surface area range. The details of the inorganic filler are the same as those described above.

The conductive layer may further include the silane coupling agent and additives described above.

The conductive layer may have a thickness of 0.5 μm to 5 μm, preferably 1 μm to 4 μm. Within the above range, it can be used for connections and can be used for display devices.

The anisotropic conductive film of the present invention can be heat-pressed by placing the anisotropic conductive film between a first substrate on which the first connected member is formed and a second substrate on which the second connected member is formed. The first substrate may be a glass substrate such as an LCD or PD panel, and a first connected member may be formed as a terminal for connection to an electronic component. 2nd connected The members may be, for example, chip on plastic (COP), flexible printed circuits (FPC), chip on film (COF), tape carrier package (TCP), etc. For example, the connected member may be a polyimide film or the like.

The method of forming the anisotropic conductive film of the present invention is not particularly limited, and methods commonly used in the art can be used. The method of forming an anisotropic conductive film does not require any special devices or equipment. The binder resin is dissolved in an organic solvent to liquefy, the remaining ingredients are added and stirred for a certain period of time to provide a conductive layer composition, and the conductive layer composition is formed into a release film. A conductive layer can be obtained by applying it to a predetermined thickness and then curing it at 80°C to 130°C for 5 to 10 minutes. An anisotropic conductive film can be obtained by applying the composition for an insulating layer to a predetermined thickness on one side of the obtained conductive layer and then drying it to volatilize the organic solvent.

The display device of the present invention includes a driver circuit; panel; and an anisotropic conductive film according to an example of the present invention. Specifically, the panel may be a liquid crystal display (LCD) device, which is a liquid crystal display (LCD) panel. Additionally, the panel may be an organic light emitting diode (OLED) display (OLED) device.

The method of manufacturing the display device of the present invention is not particularly limited and can be performed by methods known in the art.

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

Example One

of insulating layer manufacturing

A composition for an insulating layer was prepared by mixing the components shown in Table 1 below in a solvent (PGMEA, Propylene Glycol Monomethyl Ether Acetate) in the amounts (unit: parts by weight) shown in Table 1 below. The composition for an insulating layer prepared above was applied on a PET film, a release film, and the solvent was volatilized in a dryer at 70°C for 5 minutes to prepare an insulating layer with a thickness of 5 μm. In Table 1 below, the content of each component is based on solid content.

conductive layer manufacturing

A composition for a conductive layer was prepared by mixing the components shown in Table 1 below in a solvent (PGMEA) in the amounts shown in Table 1 below. The composition for a conductive layer prepared above was applied on a PET film, a release film, and the solvent was volatilized in a dryer at 70° C. for 5 minutes to prepare a conductive layer with a thickness of 1 μm.

Manufacturing of anisotropic conductive film

The prepared conductive layer and insulating layer were laminated at 40°C and 1 MPa to prepare a laminate of PET film - an anisotropic conductive film with a thickness of 6 μm having a two-layer structure in which a conductive layer and an insulating layer were laminated - PET film.

Example 2 to Example 3

In Example 1, a laminate with an anisotropic conductive film was manufactured in the same manner as Example 1, except that the components of the composition for the insulating layer were changed as shown in Table 1 below.

Comparative example 1 to Comparative example 3

In Example 1, a laminate with an anisotropic conductive film was manufactured in the same manner as Example 1, except that the components of the composition for the insulating layer were changed as shown in Table 1 below.

Example Comparative example One 2 3 One 2 3 insulating layer FX293 40 40 40 40 40 40 YX8000 30 30 30 0 30 30 EPICLON830 0 0 0 30 0 0 R812S 15 20 0 15 0 0 K-T30 0 0 15 0 0 0 UFP30 0 0 0 0 15 0 SSP07 0 0 0 0 0 15 B2A 2 2 2 2 2 2 conductive layer FX293 50 50 50 50 50 50 YP50 10 10 10 10 10 10 XD1000 30 30 30 30 30 30 N2EHHB4003S 40 40 40 40 40 40 B2A 2 2 2 2 2 2 Inorganic filler in anisotropic conductive film (% by weight) 6.8 8.9 6.8 6.8 6.8 6.8 Hydrogenated bisphenol epoxy resin in anisotropic conductive film
(weight%) 13.7 13.4 13.7 0 13.7 13.7

*FX293: Biphenyl fluorene type phenoxy resin (Shinilcheol Co., Ltd.)

*YX8000: Hydrogenated bisphenol A type epoxy resin (Mitsubishi Chemical)

*EPICLON830: Epoxy resin other than hydrogenated bisphenol A type epoxy resin (DIC Coporation)

*R812S: Nano silica with a specific surface area of 195 m ² /g to 245 m ² /g (EVONIK)

*K-T30 Nano silica with a specific surface area of 230 m ² /g to 260 m ² /g (OCI)

*UFP30: Silica with a specific surface area of 20m ² /g to 80m ² /g (Denka)

*SSP07: Silica with a specific surface area of 1 m ² /g to 10 m ² /g (Tokuyama)

*B2A: Sulfonium-based cationic latent hardener (Samshin Chemical Co., Ltd.)

*YP50: Phenoxy resin (non-fluorene type phenoxy resin, Nippon Steel Company)

*XD1000: Dicyclopentadiene epoxy resin (Japan Gunpowder Co., Ltd.)

*N2EHHB4003S: Conductive particles (SEKISUI company, average particle diameter: 3㎛)

The following physical properties were evaluated for the anisotropic conductive films prepared in Examples and Comparative Examples, and the results are shown in Table 2 and Figure 1.

(1) Insulating layer reaction start temperature and insulating layer reaction peak temperature (unit: ℃): The reaction start temperature and reaction peak temperature were calculated for the insulating layer in the anisotropic conductive film. For the insulating layer, the heat content was measured at 0°C to 250°C at a rate of 10°C/min under a nitrogen gas atmosphere using a thermal differential scanning calorimeter (DSC, TA Instrument, Q20) to determine the reaction start temperature and temperature of the thermal differential scanning calorimeter. The reaction peak temperature was calculated.

(2) Heat of reaction for anisotropic conductive film (unit: J/mg): heat amount was measured at 0°C to 250°C at a rate of 10°C/min under a nitrogen gas atmosphere using a thermal differential scanning calorimeter (DSC, TA Instrument, Q20). The heat of reaction was calculated by measuring the area of the heat generated.

(3) Melt viscosity difference (unit: Pa.s): Melt viscosity was measured using an ARES G2 rheometer (TA Instruments). An anisotropic conductive film with a thickness of 6 ㎛ was cut into length x 10 cm x 10 cm width, and the cut anisotropic conductive film was folded multiple times to prepare a sample with a thickness of 150 ㎛. The prepared sample was cut to the same size as the 8 mm diameter circular parallel plate provided in the ARES G2 rheometer. The cut sample was mounted between a circular parallel plate (upper plate) with a diameter of 8 mm and a circular parallel plate (lower plate) with a diameter of 8 mm provided on the ARES G2 rheometer, and the temperature was increased at a rate of 10°C/min and strain. Melt viscosity was measured from 20°C to 200°C at 5% and an angular velocity of 1.0 rad/sec. The difference in melt viscosity was calculated by obtaining the maximum and minimum melt viscosity values at 50°C to 120°C.

(4) Conductive particle monodisperse rate (unit: %): Monodisperse rate was measured by Image Analysis method. In the anisotropic conductive film, the monodisperse rate is calculated as (the number of monodisperse conductive particles on a unit area of 1 mm ² of the anisotropic conductive film)/(the number of conductive particles on a unit area of 1 mm ² of the anisotropic conductive film) × 100 (%).

(5) Curing rate (unit: %): The curing rate is measured according to equation 3 below.

[Equation 3]

Hardening rate (%) = [(H ₀ -H ₁ )/H ₀ ]Х100

In Equation 3, H ₀ is measured as the area under the curve of an anisotropic conductive film using a DSC (thermal differential scanning calorimeter, TA instruments, Q20) at 10°C/min in a temperature range of -50°C to 250°C under a nitrogen gas atmosphere. This is the initial calorific value, and H ₁ represents the calorific value measured in the same manner after leaving it on a hot plate at 130°C for 5 seconds).

(6) Conductive particle capture rate (unit: %): The following method was performed to measure the conductive particle capture rate of the anisotropic conductive films prepared in the above Examples and Comparative Examples.

The number of conductive particles on the terminal before compression of the anisotropic conductive film (number of particles before compression) is calculated using Equation 1 below.

[Equation 1]

Number of conductive particles before compression = Particle density of conductive particles in the conductive layer (piece/mm ² ) * Area of terminal (mm ² )

Additionally, the number of conductive particles on the terminal after compression (the number of conductive particles after compression) is counted and measured using a metallographic microscope, and then the particle capture rate of the conductive particles is calculated using Equation 2 below.

[Equation 2]

Particle capture rate = (Number of conductive particles after compression/Number of conductive particles before compression) * 100(%)

The conditions for the temporary compression and main compression are as follows.

1) Temporary compression conditions: 60℃, 1 second, 1.0MPa

2) Main compression conditions: 150℃, 5 seconds, 70MPa

(7) Initial connection resistance (unit: Ω): The following method was performed to measure the initial connection resistance of the anisotropic conductive films prepared in the above examples and comparative examples.

After provisional compression and main compression of the anisotropic conductive films prepared in the above examples and comparative examples under the following conditions, the initial connection resistance was measured by applying a test current of 1 mA using a 4-probe method using a measuring instrument (Keithley 2000 Multimeter). Then, the average value was calculated.

1) Temporary compression conditions: 60℃, 1 second, 1.0MPa

2) Main compression conditions: 150℃, 5 seconds, 70MPa

(8)Reliability Post-connection resistance (unit: Ω): The following method was performed to measure the connection resistance after reliability of the anisotropic conductive films prepared in the above examples and comparative examples. Using the same method as the initial connection resistance measurement, temporary compression and main compression were performed, and the high-temperature and high-humidity reliability was evaluated by leaving it for 100 hours under the conditions of a temperature of 85°C and a relative humidity of 85%, and then measuring the connection resistance after each reliability. was measured in the same manner as the initial connection resistance.

(9) Insulation resistance (unit: %): The anisotropic conductive film formed above was cut into 2 mm * 25 mm and bonded to each insulation resistance evaluation material for evaluation. At this time, the anisotropic conductive film was pressure-bonded on a 0.5 mm thick glass substrate by heating and pressing under the conditions of 60°C, 1 MPa, and 1 sec. The PET film was peeled off, and the anisotropic conductive film was placed on the glass substrate. Next, the chips (chip length 19.5 mm, chip width 1.5 mm, bump spacing 8 μm) were aligned and placed, and then main compression was performed under the conditions of 150°C, 70 MPa, and 5 sec. Here, 50V was applied and a total of 38 points were tested for short circuits using the two-terminal method.

(10) Modulus (unit: GPa): An anisotropic conductive film was left in a hot air oven at 150°C for 2 hours, and then the temperature was increased from 0°C to 100°C using a DMA (Dynamic Mechanical Analyzer, TA's Q800) at a temperature increase rate of 5°C/ The modulus at 30°C was measured while increasing the temperature in minutes.

Example Comparative example One 2 3 One 2 3 Insulating layer reaction start temperature 110 110 110 110 110 110 Insulating layer reaction peak temperature 120 120 120 120 120 120 Anisotropic conductive film reaction heat 2 2 2 2 2 2 Melt viscosity difference 2,500 500 2,500 20,000 5,600 7,200 Conductive particle monodisperse rate 95 95 96 35 27 48 cure rate 86 88 89 86 86 86 Conductive particle capture rate 85 92 84 65 43 52 Initial connection resistance 1.5 2.5 1.5 4.5 7.5 8.6 Connection resistance after reliability 1.8 4.5 1.9 12.5 21.1 26.7 Insulation Resistance 0 0 0 12 10 14 modulus 2.5 2.8 2.7 1.5 2.8 2.9

As shown in Table 2, the anisotropic conductive film of the present invention has a low difference between the maximum and minimum melt viscosity in the section between the melting start temperature and the curing start temperature of the anisotropic conductive film, resulting in uneven compression when applied to a polymer film adherend. can be resolved. In addition, the anisotropic conductive film of the present invention had a high particle capture rate of conductive particles, a high monodisperse rate of conductive particles, low connection resistance, excellent connection resistance reliability, and low insulation resistance. Additionally, as shown in Figure 1, in Example 2, the difference between the maximum and minimum melt viscosity values at 50°C to 120°C was very low at 500 Pa.s.

On the other hand, the comparative example that did not contain hydrogenated bisphenol epoxy resin or did not contain an inorganic filler with a specific surface area of 150 m ² /g to 300 m ² /g could not obtain all the effects of the present invention. Additionally, as shown in Figure 1, in Comparative Example 1, the difference between the maximum and minimum melt viscosity values was very high at 50°C to 120°C.

Simple modifications or changes to the present invention can be easily implemented by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (20)

It is an anisotropic conductive film containing an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g and a hydrogenated bisphenol epoxy resin,
The anisotropic conductive film is an anisotropic conductive film in which the difference between the maximum value of melt viscosity and the minimum value of melt viscosity is 500 Pa.s to 3000 Pa.s at 50°C to 120°C.
The anisotropic conductive film of claim 1, wherein the anisotropic conductive film includes a conductive layer and an insulating layer.
The anisotropic conductive film of claim 1, wherein the inorganic filler is included in an amount of 1% to 20% by weight of the anisotropic conductive film.
The anisotropic conductive film of claim 1, wherein the inorganic filler has an average particle diameter of 5 nm to 20 nm.
The method of claim 1, wherein the inorganic filler is silica, alumina, titania, zirconia, magnesia, ceria, zinc oxide, iron oxide, silicon nitride, titanium nitride, boron nitride, calcium carbonate, aluminum sulfate, aluminum hydroxide, calcium titanate, talc, and silicic acid. An anisotropic conductive film containing at least one of calcium and magnesium silicate.
The anisotropic conductive film of claim 1, wherein the hydrogenated bisphenol epoxy resin is contained in an amount of 5% to 40% by weight of the anisotropic conductive film.
The anisotropic conductive film of claim 1, wherein the anisotropic conductive film has a conductive particle monodispersion rate of 90% or more.
The anisotropic conductive film of claim 1, wherein the anisotropic conductive film has a conductive particle capture rate of 80% or more.
The method of claim 1, wherein the anisotropic conductive film is placed between the first connected member and the second connected member, and temporarily compressed under conditions of 60°C to 80°C, 0.5 second to 1 second, and 0.5 to 1.0 MPa pressure; And when the anisotropic conductive film is subjected to main compression under conditions of 140°C to 160°C, 5 seconds to 7 seconds, and 50 to 90 MPa pressure, the connection resistance is 3Ω or less.
The method of claim 1, wherein the anisotropic conductive film is placed between the first connected member and the second connected member, and temporarily compressed under conditions of 60°C to 80°C, 0.5 seconds to 1 second, and 0.5 to 1.0 MPa pressure; and after main compression at 140°C to 160°C for 5 to 7 seconds and 50 to 90 MPa pressure, and then left for 100 hours under conditions of 85°C and 85% relative humidity, the connection resistance after reliability measured is 6Ω or less. Phosphorus, anisotropic conductive film.
The anisotropic conductive film of claim 1, wherein the anisotropic conductive film has a modulus of 2.0 GPa or more at 30°C.
The anisotropic conductive film of claim 2, wherein the insulating layer includes the hydrogenated bisphenol epoxy resin, an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g, a binder resin, and a curing agent.
The anisotropic conductive film of claim 12, wherein the binder resin includes a biphenyl fluorene type phenoxy resin.
The method of claim 12, wherein the insulating layer comprises 20% to 40% by weight of the hydrogenated bisphenol epoxy resin, and 10% to 40% by weight of an inorganic filler having a specific surface area of 150 m ² /g to 300 m ² /g. An anisotropic conductive film comprising 20% to 55% by weight of binder resin and 1% to 5% by weight of the curing agent.
The anisotropic conductive film of claim 2, wherein the conductive layer includes a binder resin, an epoxy resin, a curing agent, and conductive particles.
The anisotropic conductive film of claim 15, wherein the binder resin includes a biphenyl fluorene type phenoxy resin.
The method of claim 15, wherein in the conductive layer, 20% to 55% by weight of the binder resin, 20% to 40% by weight of the epoxy resin, 1% to 5% by weight of the curing agent, and 20% to 5% by weight of the conductive particles. An anisotropic conductive film containing 50% by weight.
A display device comprising the anisotropic conductive film of any one of claims 1 to 17.
The display device of claim 18, wherein the display device includes chip on plastic (COP), flexible printed circuits (FPC), chip on film (COF), or tape carrier package (TCP).
The display device of claim 18, wherein the display device includes a polyimide film.