KR100986772B1 - Anisotropic Conductive Film Having A Good Thermal And Hardening Property And Circuit Board Using The Same - Google Patents

Abstract

The present invention relates to an anisotropic conductive film that mechanically and electrically connects members to be connected to each other, and comprises a thermosetting resin, a curing agent, conductive particles, and a release film as a thermoplastic resin and a binder for forming a film. = (Tc-Tg) / Tc), where λ represents the flow parameter, Tc represents the curing initiation temperature of the anisotropic conductive film, Tg represents the glass transition temperature of the anisotropic conductive film) is greater than 0.05, 0.4 It is characterized by having a smaller value.

Glass transition temperature, curing start temperature, flow parameters, anisotropic conductive film (ACF)

Description

Anisotropic Conductive Film Having A Good Thermal And Hardening Property And Circuit Board Using The Same}

The present invention relates to an anisotropic conductive film used for connecting circuit boards or electronic components such as IC chips and wiring boards, and a circuit connection structure using the same. More specifically, the thermal and hardening properties are optimized to improve connection reliability. It relates to an excellent anisotropic conductive film.

In order to electrically connect circuit boards or electronic components, such as an IC chip, and a circuit board, the anisotropic conductive film in which the electroconductive particle is disperse | distributed to the adhesive agent is used. In this case, the anisotropic conductive film is disposed between the electrodes facing each other, the electrodes are connected by heating and pressurization, and then electrically connected by making the conductive in the pressing direction. Such anisotropic conductive films are typically used for packaging LCD panels, printed circuit boards (PCBs), and driver ICs.

LCDs are currently applied to a wide range of applications, from large panels for notebook PCs, monitors, and televisions to medium and small panels for mobile devices such as mobile phones, PDAs, and game machines. Driver IC mounting is adopted. Driver IC mounting in LCDs uses an OLB (Outer Lead Bonding) method or a printed circuit board that converts the driver IC into a Tape Carrier Package (TCP) or a Chip On Film (COF) and adheres it to the LCD panel. PCB: PCB type is attached to the printed circuit board. In addition, in small and medium-sized LCDs such as mobile phones, a COG (Chip On Glass) method in which a driver IC is directly mounted on an LCD panel by an anisotropic conductive film is adopted.

As described above, connection reliability between the circuit boards and electronic components such as IC chips and the circuit board using an anisotropic conductive film is the most problematic. That is, in the anisotropic conductive film, excellent conduction reliability is required along with high adhesiveness.

Therefore, various efforts have been made in the past to improve the connection reliability of the anisotropic conductive film. Representative examples include attempting to change the structure, such as forming an anisotropic conductive film in multiple layers, or adjusting the type and composition ratio of the adhesive composition and the conductive particles.

However, in order to improve the connection reliability of the anisotropic conductive film, efforts to adjust the characteristic values of the anisotropic conductive adhesive itself, such as thermal properties or curing properties, have not been found.

An object of the present invention is to find a key characteristic factor (i.e., a flow parameter) that can influence the connection reliability of an anisotropic conductive film, and to obtain an optimum value of the characteristic factor found.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

The anisotropic conductive film is composed of a thermoplastic resin for forming a film, a thermosetting resin used as a binder, conductive particles, and a release film. The anisotropic conductive film is interposed between circuit members opposing each other, and then opposed to each other by thermal compression (ie, to be connected). Members) are bonded to each other and electrically connected.

That is, the anisotropic conductive film is an adhesive film which connects the connected members mechanically as well as electrically to each other by applying pressure in a state in which a resin component (thermoplastic resin and thermosetting resin) is flowed using heat applied during thermocompression bonding. The anisotropic conductive film shows a flow characteristic that can realize the connection characteristics when the viscosity decreases as the temperature increases and the glass transition temperature is higher. In addition, when heat above the curing start temperature is applied to the anisotropic conductive film, the thermosetting resin is cured and the viscosity is increased again.

At this time, if the glass transition temperature is too high relative to the curing start temperature or the curing start temperature is relatively too low compared to the glass transition temperature, curing occurs before the conductive particles are sufficiently pressed, resulting in poor connection reliability. In addition, if the glass transition temperature is too low relative to the curing start temperature or the curing start temperature is too high relative to the glass transition temperature, the flow characteristic section becomes too long, causing problems of adhesion performance such as bubbles. .

As such, the glass transition temperature and the curing start temperature of the anisotropic conductive film are very important factors to realize the connection reliability of the anisotropic conductive film. In other words, in order to make an anisotropic conductive film having excellent connection reliability, it is necessary to position the glass transition temperature and the curing start temperature within a specific flow characteristic interval η ₁ to η ₂ to have an appropriate temperature difference.

Therefore, the present inventors have grasped the correlation between the glass transition temperature and the curing start temperature of the anisotropic conductive film, and created a new factor for controlling the temperature. That is, in the anisotropic conductive film having desirable connection reliability, the flow parameter represented by Equation 1 below should exist within a predetermined numerical range.

λ = (Tc-Tg) / Tc

Here, λ means a flow parameter, Tc represents the curing start temperature [K] of the anisotropic conductive film, and Tg represents the glass transition temperature [K] of the anisotropic conductive film.

The anisotropic conductive film according to the present invention realizes high adhesion and conduction reliability in electrically connecting circuit boards or electronic components such as IC chips and circuit boards.

Hereinafter, the present invention will be described in detail with reference to the drawings. In each figure, the same reference numerals indicate the same or equivalent components.

1 shows a state in which anisotropic conductive film 10 according to the present invention is interposed between circuit boards 20 and 30 facing each other.

The anisotropic conductive film 10 is composed of a thermoplastic resin for forming a film, a thermosetting resin as a binder, a curing agent, conductive particles, a release film, and other additives.

Examples of the thermoplastic resin include polyvinyl butyral, polyvinyl formal, polyvinyl acetal, polyamide, phenoxy resin, poly monkeyphone, styrene-butadiene-styrene block copolymer, carboxylated styrene-ethylene-butylene-styrene A block copolymer, polyacrylate resin, etc. can be used 30 to 60 weight%.

An epoxy resin or an acrylate resin may be used as the thermosetting resin.

Preferred examples of the epoxy resin include polyvalent epoxy resins having two or more glycidyl groups in one molecule. For example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, and biphenyls. 5 to 45 weight% can be used individually or in mixture of a type | mold epoxy resin, a dicyclopentadiene type epoxy resin, and a naphthalene type epoxy resin.

At this time, the curing agent is preferably a curing agent for epoxy resin, in particular, imidazole compound, amine-based as a latent curing agent excellent in storage stability, fast curing speed From compounds, acid anhydride compounds, polyamide compounds and isocyanate compounds Preference is given to using at least one selected. Specifically, dicumyl peroxide, thi-butyl- cumyl peroxide, bis (alpha-thi-butyl peroxyisopropyl) benzene, 2,5-di (thi-butylperoxy) -2,5- Dimethylhexine-3, diterbutylperoxide, 1,1-di (terbutylperoxy) -3,3,5-trimethylcyclohexane, en-butyl-4,4-di- (terbutylperper Oxy) vallate, 1,1-di-terbutylperoxycyclohexane, isopropylcumylterbutylperoxide, bis (alpha-teramylperoxyisopropyl) benzene, imidazole, 2-ethyl imidazole, 2- Phenyl-4-methyl imidazole, 2-dodecyl imidazole, 2-phenyl imidazole, 2-phenyl-4-methyl imidazole, 4-methyl imidazole, boron trifluoride-amine complex, sulfonium salt, amineimide , And a composition selected from salts of polyamines, dicyandiamides and the like can be used alone or in a mixture of 0.1 to 20% by weight.

As the acrylate monomer constituting the acrylate resin, radical polymerization having a functional group polymerized by radicals such as an acrylic monomer, a methacryl monomer, a maleimide compound, an unsaturated polyester, acrylic acid, vinyl acetate, and acrylonitrile The resin is used, specifically methyl acrylate, ethyl acrylate, bisphenol A-ethylene glycol modified diacrylate, isocyanuric acid ethylene glycol modified diacrylate, pentaerythritol triacrylate, trimetholpropane triacrylic Rate, trimetholpropane propylene glycol modified triacrylate, isocyanuric acid ethylene glycol modified triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, dicyclopentenyl Acrylate, Tricyclodecanyl acrylate, ethylene iso amyl acrylate, lauryl acrylate, stearyl acrylate, butoxy ethyl acrylate, ethoxy diethylene glycol acrylate, methoxy triethylene glycol acrylate, methoxy polyethylene glycol Acrylates, methoxy dipropylene glycol acrylates, phenoxy ethyl acrylates, phenoxy polyethylene glycol acrylates, isobornyl acrylates, 2-hydroxy ethyl acrylates, 2-hydroxy propyl acrylates, methyl methacrylates, Isobutyl methacrylate, tridecyl methacrylate, methoxy diethylene glycol methacrylate, methoxy polystyrene glycol methacrylate, perryl methacrylate, perryl acrylate, isobutyl acrylate, isobornyl meth Acrylate, methoxy triethylene Glycol methacrylate or the like may be used alone or in combination of two or more thereof. At this time, the acrylate monomer is preferably contained 30 to 70% by weight.

In addition, an azo compound and an organic peroxide may be used as the curing initiator for the acrylate resin, specifically, dicanoyl peroxide, benzoyl peroxide, dicumyl peroxide, dibutyl peroxide, cumene hydroper Oxide, t-butyl-cumylperoxide, bis (alpha-thi-butylperoxyisopropyl) benzene, 2,5-di (thi-butylperoxy) -2,5-dimethylhexane , 2,5-di (thi-butylperoxy) -2,5-dimethylhexine-3, diterbutylperoxide, 1,1-di-terbutylperoxycyclohexane, isopropylcumylterbutyl A composition selected from peroxides, bis (alpha-teramylperoxyisopropyl) benzene and the like can be used alone or in combination. At this time, the curing initiator is preferably contained 0.1 to 30% by weight.

The said electroconductive particle is for electrically connecting a to-be-connected body, such as a microcircuit electrode, and can use a wide range of particle | grains which are high in melting | fusing point and hardness, and excellent in electroconductivity. Such conductive particles include gold (Au), silver (Ag), iron (Fe), copper (Cu), nickel (Ni), cadmium (Cd), bismuth (Bi), indium (In), aluminum (Al), palladium (Pd), platinum (Pt), chromium (Cr) and the like, polystyrene, polymethacrylate, polymethylmethacrylate, polyvinylacetate, divinylbenzene, benzoguanamine and the like can be exemplified. As the conductive particles of the present invention, silver powder or nickel powder may be used as it is. At this time, it is preferable to use 1-10 weight% of conductive particle which has a uniform particle size distribution within ± 0.1 micrometer, and whose diameter is 3-20 micrometers.

In addition, coupling agents, tackifiers, and the like may additionally be used as additives.

The anisotropic conductive film having the above-described configuration is a flow parameter described in detail below by changing the type or content of the thermoplastic resin, the type or content of the thermosetting resin, the type or content of the curing agent or curing initiator and the type of the additive, etc. It is possible to adjust (λ) in various ways.

Below, the flow parameter (lambda) as an index which shows the connection reliability (adhesiveness, conduction reliability) of an anisotropic conductive film is demonstrated in detail.

2 is a graph showing the change in viscosity with temperature of the anisotropic conductive film. Referring to the drawings, when the anisotropic conductive film receives heat, the viscosity is lowered to a certain temperature and then the viscosity increases as curing begins. At this time, when the viscosity at the time of curing of the anisotropic conductive film exceeds a specific viscosity (η ₂ ), the fluidity does not show enough that the conductive particles are sufficiently pressed, and when the viscosity is lower than the specific viscosity (η ₁ ), the fluidity is excessive and the bubble characteristics and Adhesion properties deteriorate. That is, in the region B of FIG. 2, the anisotropic conductive film shows sufficient fluidity such that the conductive particles are pressed by thermocompression bonding. However, in the region C, the fluidity is lowered, so that the conductive particles are not sufficiently pressed, and in the region A, the fluidity is excessive, and the bubble property and the adhesive property deteriorate.

Therefore, the anisotropic conductive film should remain in region B of FIG. 2 until the conductive particles are sufficiently pressed. For this purpose, the glass transition temperature (Tg) and curing start temperature (Tc) of the anisotropic conductive film should have a desired value, and the temperature difference (ΔT = Tc-Tg) should be appropriate.

3 is a graph showing a change in viscosity with temperature of four anisotropic conductive films having different glass transition temperatures. Referring to the drawings, a, b, c, and d are anisotropic conductive films having glass transition temperatures of Tga, Tgb, Tgc, and Tgd (Tgd <Tga <Tgb <Tgc), respectively, where a and b have a viscosity B region upon curing. In the case of c, the viscosity remains in the region C during curing, and d is the viscosity in the region A during curing.

Therefore, in order for an anisotropic conductive film to have excellent connection reliability, it must have an appropriate glass transition temperature as shown in FIGS. If the glass transition temperature of the anisotropic conductive film is too low, such as d, or too high, such as c, it may not have sufficient conductive ball pressing characteristics or flow characteristics indicating adhesive performance.

Figure 4 is a graph showing the change in viscosity with the temperature of the four anisotropic conductive films different from the curing start temperature. Referring to the drawings, e, f, g, and h are anisotropic conductive films having curing start temperatures Tce, Tcf, Tcg, and Tch (Tcg <Tcf <Tce <Tch), respectively. In the case of g, the viscosity remains in the region C during curing, and the h stays in the region A during curing.

Therefore, in order for an anisotropic conductive film to have excellent connection reliability, it should have an appropriate curing start temperature as shown in FIG. If the curing start temperature of the anisotropic conductive film is too low, such as g, or too high, such as h, it may not have sufficient conductive ball pressing characteristics or flow characteristics indicating adhesive performance.

In addition, the anisotropic conductive film should be cured as soon as the glass transition temperature is reached, or the curing should not be made too late while the glass transition temperature is reached. If curing is started as soon as the anisotropic conductive film reaches the glass transition temperature, the conductive particles are not sufficiently pressed. Therefore, the curing start temperature (Tc) [K] of the anisotropic conductive film preferably has a value of 20 [K] or more larger than the glass transition temperature (Tg) [K].

As described above, in the anisotropic conductive film, the glass transition temperature and the curing start temperature should be defined so that the viscosity at the time of curing is present in the flow characteristic region (B region of FIGS. 2 to 4), and the curing start temperature and the glass transition temperature have a constant temperature difference. (ΔT = Tc-Tg> 20 [K]).

Such a flow characteristic of the anisotropic conductive film may be expressed by a flow parameter λ represented by Equation 2 below.

λ = (Tc-Tg) / Tc

Here, λ means a flow parameter, Tc represents the curing start temperature of the anisotropic conductive film, Tg represents the glass transition temperature of the anisotropic conductive film.

The present inventors have found that the anisotropic conductive film having excellent connection reliability can be manufactured by appropriately adjusting the value of the flow parameter λ of the anisotropic conductive film.

That is, the anisotropic conductive film having excellent connection reliability should have a flow parameter λ greater than 0.05 and less than 0.4 (that is, 0.05 <λ <0.4). At this time, the curing start temperature of the anisotropic conductive film has 323K to 393K. It is preferable that the temperature difference between the curing start temperature and the glass transition temperature is 20 K or more.

If the flow parameter (λ) of the anisotropic conductive film is less than 0.05, indentation failure occurs because the curing is completed before the conductive particles are sufficiently pressed due to rapid curing, and if the flow parameter (λ) is larger than 0.4, Excessive fluidity leads to poor bubble and adhesion properties.

The flow parameter [lambda] can be adjusted by changing the types and amounts of thermoplastic resins, thermosetting resins (epoxy resins or acrylate resins), curing agents (or curing initiators), and additives constituting the anisotropic conductive film.

The curing start temperature (Tc) of the anisotropic conductive film depends on the type of curing agent or curing initiator.

Table 1 below illustrates the half-life temperature of typical curing agents (half-life temperature: a measure of the temperature at which the curing agent decreases in half for a period of time) and is proportional to the curing start temperature.

Hardener Half-life temperature [K] Decanoyl peroxide 356 K Succinic Acid Peroxide 363 K Benzoyl peroxide 365 K Dicumyl Peroxide 410 K 2,5-Di (t-butylperoxy) -2,5-dimethylhexane 413 K Di (t-butyl) Peroxide 423 K Cumene Hydroperoxide 461 K t-Butyl Hydroperoxide 474 K

As can be seen from Table 1, each of the curing agents are different from each other half-life temperature, thereby causing the curing start temperature (Tc) of the anisotropic conductive film using a curing agent having a different half-life temperature. That is, the anisotropic conductive film using a curing agent having a low half-life temperature and a fast curing rate also lowers the flow parameter λ by lowering the curing start temperature. On the other hand, the anisotropic conductive film using a curing agent having a high half-life temperature and a slow curing rate also increases the flow parameter λ by increasing the curing start temperature.

Therefore, it is possible to adjust the flow parameter (λ) of the anisotropic conductive film to be larger than 0.05 and smaller than 0.4 only by using a curing agent (or curing initiator) having different half-life temperatures under the same conditions.

In addition, even if a curing agent having the same half-life temperature is used, when the amount is increased, the flow parameter λ is lowered, and when the amount is decreased, the flow parameter λ is increased.

Therefore, it is possible to adjust the flow parameter (λ) of the anisotropic conductive film to be larger than 0.05 and smaller than 0.4 by adjusting the content of the curing agent under all conditions.

In addition, the glass transition temperature (Tg) of the anisotropic conductive film defining the flow parameter is controlled by the type of thermosetting resin, the type of thermoplastic resin, or the component ratio thereof, and maintains excellent characteristics of the anisotropic conductive film by various combinations thereof. It is possible to express various glass transition temperatures. In particular, the glass transition temperature of the anisotropic conductive film largely depends on the glass transition temperature of the thermoplastic resin.

Table 2 below illustrates the glass transition temperatures of representative thermoplastic resins.

Thermoplastic resin Glass transition temperature [K] Polyethylene 143 K Polydimethylsiloxane 150 K Polytetrafluoroethylene 160 K Polybutadiene 188 K Polyurethane 213 K Polymethyl acrylate 282 K Polyvinyl chloride 355 K Polymethyl methacrylate 378 K

As can be seen from Table 2, the glass transition temperature of the thermoplastic resin is different, and the glass transition temperature of the anisotropic conductive film using the thermoplastic resin is also different. In general, the glass transition temperature of the anisotropic conductive film using a thermoplastic resin having a high glass transition temperature is high, and the glass transition temperature of the anisotropic conductive film using a thermoplastic resin having a low glass transition temperature is low.

Therefore, it is possible to adjust the flow parameter? Of the anisotropic conductive film to be larger than 0.05 and smaller than 0.4 even by using thermoplastic resins having different glass transition temperatures under the same conditions.

In addition, when a thermoplastic resin having a radical curing retardation effect (for example, an acrylic polyfunctional monomer such as methacrylate, maleimide compound, unsaturated polyester, acrylic acid, vinyl acetate, acrylonitrile, etc.) is used, It is possible to adjust the flow parameters.

In addition, it is possible to control the flow parameters through the change of the thermosetting monolayer (ie, the acrylate monomer). That is, the reaction rate and the curing density can be controlled by controlling the number and molecular weight of the functional groups of the thermosetting monomer, and consequently, the flow parameters can be controlled. That is, generally, the larger the number of functional groups, the faster the reaction rate, the higher the crosslinking density, and the lower the flow parameter. Conversely, the smaller the number of functional groups, the lower the reaction rate, the lower the crosslinking density, and the higher the flow parameters.

In addition, the flow parameters may be controlled using radical curing accelerators, chain transfer aids, molecular weight regulators, etc. The flow parameter λ can also be adjusted to be larger than 0.05 and smaller than 0.4 by adjusting the composition ratio of h).

Hereinafter, a plurality of anisotropic conductive films having various flow parameters (λ) were prepared, the connection resistance characteristic values of the anisotropic conductive films thus prepared were measured, the film formability was observed, and the results are summarized in a table.

[Production of Anisotropic Conductive Film]

A solution for coating a film by dissolving or dispersing an adhesive composition comprising a thermoplastic resin for forming a film, an epoxy thermosetting resin (or an acrylate monomer) as a binder, a curing agent (or a curing initiator) in an organic solvent, and further dispersing conductive particles. To prepare. The organic solvent used at this time is preferable because the mixed solvent of an aromatic hydrocarbon type and an oxygen type improves the solubility of a material. Subsequently, this solution is apply | coated to the transparent PET film which surface-treated the single side | surface using the tapping machine value, and an anisotropic conductive film is obtained by 70 degreeC hot air drying for 10 minutes.

[Manufacture of circuit connection structure]

5 illustrates an OLB method or a PCB method connection process for bonding COF or TCP to a glass substrate or a PCB substrate through an anisotropic conductive film.

As shown in the figure, the anisotropic conductive film 10 according to the present invention is pressed on a glass substrate or a PCB substrate 31, and the COF or TCP 22 is disposed on the anisotropic conductive film. Subsequently, the circuit connection structure was heated and pressurized for 7 seconds at 180 ° C. and 3 MPa using a heating bar 41 through a buffer 42 made of 0.15T Teflon sheet on the COF or TCP 22. To produce.

At this time, the anisotropic conductive film used for the circuit connection structure is manufactured to have the following glass transition temperature (Tg) and curing start temperature (Tc).

Example 1

An anisotropic conductive film (λ = 0.29) having a glass transition temperature (Tg) of 236K and a curing start temperature (Tc) of 373K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Example 2

An anisotropic conductive film (λ = 0.24) having a glass transition temperature (Tg) of 283K and a curing start temperature (Tc) of 373K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Example 3

An anisotropic conductive film (λ = 0.31) having a glass transition temperature (Tg) of 273K and a curing start temperature (Tc) of 393K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Example 4

An anisotropic conductive film (λ = 0.21) having a glass transition temperature (Tg) of 278K and a curing start temperature (Tc) of 353K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Comparative Example 1

An anisotropic conductive film (λ = 0.04) having a glass transition temperature (Tg) of 357K and a curing start temperature (Tc) of 373K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Comparative Example 2

An anisotropic conductive film (λ = 0.43) having a glass transition temperature (Tg) of 213K and a curing start temperature (Tc) of 373K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Comparative Example 3

An anisotropic conductive film (λ = 0.04) having a glass transition temperature (Tg) of 282K and a curing start temperature (Tc) of 295K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Comparative Example 4

An anisotropic conductive film (λ = 0.42) having a glass transition temperature (Tg) of 274K and a curing start temperature (Tc) of 472K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

Comparative Example 5

An anisotropic conductive film (λ = 0.43) having a glass transition temperature (Tg) of 275K and a curing start temperature (Tc) of 484K was produced, and the anisotropic conductive film was applied to the circuit connection structure.

For the anisotropic conductive film produced through the above Examples and Comparative Examples, (1) conduction reliability test and (2) film formability test were performed, and the results are shown in Table 3.

(1) conduction reliability test

A resistance value (Ω _a) after temperature and 85% in 85 ℃ the aging for 500 hours at a relative humidity was measured using a multimeter.

At this time, when the resistance value Ω _a after aging was not measured, "OPEN" was indicated.

(2) film formability test

According to the preparation method of the present invention, a mixing solution is prepared, and the solution is applied to a transparent PET film having a single surface surface treated using a tapping machine, and finally obtained in the process of obtaining an anisotropic conductive film by hot air drying at 70 ° C. for 10 minutes. When the film is visually observed, phase separation and non-uniform mixing are not observed, and when the transparent PET film can be removed without difficulty, O, otherwise, no film formation itself is observed, or phase separation and non-uniform mixing are observed. In case where the removal is difficult due to the adhesion of the mixing solution, it is indicated by X.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 λ 0.29 0.24 0.31 0.21 0.04 0.43 0.04 0.42 0.43 Ω _a [Ω] 1.0 1.7 0.8 1.1 3.5 OPEN 3.4 3.2 10 Film formability ○ ○ ○ ○ × × × × ×

As can be seen from Table 3, the anisotropic conductive films of Examples 1 to 4 all exhibit excellent conduction reliability and film formability. However, Comparative Examples 1 to 5, an anisotropic conductive film having a resistance value after aging is poor (Ω _a) is the conduction reliability as more than 2Ω and all bad, the film-forming properties.

Therefore, as in Examples 1 to 4, it can be confirmed that the adhesion and conduction reliability of the anisotropic conductive film having a flow parameter larger than 0.05 and smaller than 0.4 are excellent.

The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.

1 is a state diagram in which an anisotropic conductive film is interposed between opposing circuit members.

2 is a graph showing the change in viscosity with temperature of the anisotropic conductive film.

3 is a graph showing a change in viscosity with temperature of four anisotropic conductive films having different glass transition temperatures.

Figure 4 is a graph showing the change in viscosity with the temperature of the four anisotropic conductive films different from the curing start temperature.

5 is a connection process diagram for bonding COF or TCP to a glass substrate or a PCB via an anisotropic conductive film.

<Explanation of symbols for the main parts of the drawings>

10: anisotropic conductive film 31: glass substrate or PCB

32: printed circuit board 21: semiconductor chip

22: COF or TCP 41: Heating bar

42: cushioning material

Claims (8)

An anisotropic conductive film that connects members to be connected mechanically as well as electrically, The anisotropic conductive film is composed of a thermoplastic resin for forming a film, a thermosetting resin, a curing agent, conductive particles and a release film as a binder, Anisotropic conductive film, characterized in that the flow parameter (λ) represented by the following equation has a value greater than 0.05, less than 0.4. λ = (Tc-Tg) / Tc (Where λ represents a flow parameter, Tc represents the curing start temperature [K] of the anisotropic conductive film, and Tg represents the glass transition temperature [K] of the anisotropic conductive film). The method of claim 1, Anisotropic conductive film, characterized in that the curing start temperature of the anisotropic conductive film has a value between 323K ~ 393K. The method of claim 2, Anisotropic conductive film, characterized in that the temperature difference between the curing start temperature (Tc) and the glass transition temperature (Tg) of the anisotropic conductive film is 20K or more. The method of claim 3, wherein The thermosetting resin is an anisotropic conductive film, characterized in that the epoxy resin. The method of claim 3, wherein Anisotropic conductive film, characterized in that the thermosetting resin is an acrylate resin. The method according to claim 4 or 5, The connected member is composed of a first circuit member and a second circuit member, The first circuit member is a tape carrier package (TCP) or a chip on film (COF), and the second circuit member is a glass substrate or a printed circuit board (PCB). A circuit connection structure electrically and mechanically connected between a first circuit member and a second circuit member by thermocompression bonding through the anisotropic conductive film according to any one of claims 1 to 5. The method of claim 7, wherein The first circuit member is a Tape Carrier Package (TCP) or a Chip On Film (COF), and the second circuit member is a glass substrate or a printed circuit board (PCB).

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