KR100714794B1 - Low temperature and rapid curable anisotropic conductive film, and method for preparing the same - Google Patents

Abstract

The present invention relates to an anisotropic conductive film and a method for producing the same. More specifically, the present invention relates to an anisotropic conductive film for preventing shrinkage and securing connection reliability of an anisotropic conductive film comprising an acrylate resin, a (meth) acrylate monomer, a radical initiator, A phenoxy resin, and a rubber resin, and a method for producing the same.

The anisotropic conductive film of the present invention contains a phenoxy resin and a rubber resin having high heat resistance and moisture resistance and causes a rapid curing reaction at a low temperature and exhibits a shrinkage phenomenon during reliability evaluation under high temperature and high humidity conditions (85 DEG C x 85% RH) There is an advantage that the adhesive strength and the connection resistance holding effect are excellent.

Low temperature fast curing type, anisotropic conductive film, adhesion strength, connection resistance, shrinkage

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anisotropic conductive film and a method for manufacturing the same,

1 is a photograph of the anisotropic conductive film according to Examples 1 to 3 and Comparative Examples 1 to 4 after treatment at 85 ° C x 85% RH x 100 hr.

[Industrial Applications]

The present invention relates to an anisotropic conductive film, and more particularly, to an anisotropic conductive film excellent in reliability and physical properties at high temperature and high humidity, and a method for producing the same.

BACKGROUND ART [0002]

Today, digital information networks are composed in almost all areas, and the massive transfer of multimedia information is constantly being carried out.

At this time, a flat panel display (FPD), which is represented by a liquid crystal display (LCD), a plasma display panel (PDP) or the like, has the most important position in the multimedia age.

In FPD, application products are developed and commercialized in various aspects, mainly in mobile products, in the form of thin, lightweight, and low power consumption devices. In the future, it is expected that more and more thinner and smaller power consumption is expected in vehicle-mounted TV and video .

Accordingly, a significant rationalization is required for the device configuration and the process of the FPD module. To meet this demand, the mounting method of driver (LSI) in FPD module has been shifted from QFP (Quad Flat Package) method to TAB (Tape Automated Bonding) method and COG (Chip On Glass) Is the application of anisotropic conductive film (ACF).

The anisotropic conductive film has been used for bonding an ITO terminal and a chip connection electrode terminal on a glass substrate of a liquid crystal display panel and electrically connecting the ITO terminal and the chip connection electrode terminal. Recently, anisotropic conductive films have been used for power generation of computer monitors, televisions, As a result, the distance between the terminals gradually becomes smaller.

Accordingly, improvement of the heat resistance and moisture resistance of the anisotropic conductive film is demanded. Normally, as an insulating binder of ACF, a thermosetting resin and a latent curing agent (hereinafter, referred to as a 'high temperature curing type ACF') and a thermoplastic Resin and a radical initiator curing system (hereinafter referred to as " low-temperature curing type ACF ").

The high temperature curing type ACF is advantageous in heat resistance and moisture resistance. However, in order to obtain reliable adhesion and reliable connection between terminals, the ACF should be thermally pressed at a temperature of 180 ° C or higher for about 15 seconds or longer. , The terminals of the liquid crystal display panel and the chip connection terminals may be subjected to thermal stress.

The general low-temperature curing type ACF can be pressed at a low temperature for a short period of time and has an excellent repairing property. However, the ACF has a high melt viscosity at the time of compression and is low in heat resistance, causing shrinkage and expansion, Environmental reliability was limited.

Therefore, it is necessary to develop an ACF having excellent heat resistance and moisture resistance while having a rapid reaction time of 7 to 10 seconds at a low temperature of 140 to 160 캜.

Korean Patent Publication Nos. 341316 and 423237 disclose an anisotropic conductive film capable of improving adhesion strength after curing with a liquid crystal display panel and curing at a low temperature. However, the ACF described in the above publication is composed of an acrylate resin and a peroxide or an azo compound. When the reliability (85 캜 x 85% RH) of the insulating adhesive layer due to surface contraction occurs under high temperature / The adhesive strength and the connection reliability, which are characteristics of the anisotropic conductive film, may deteriorate.

The object of the present invention is to provide a resin composition for an anisotropic conductive film of low temperature curing type which is improved in reliability and physical properties under high temperature and high humidity by adding phenoxy resin and rubber resin, And to provide an improved anisotropic conductive film.

Another object of the present invention is to provide a method for producing the anisotropic conductive film.

The present invention provides an anisotropic conductive film comprising an acrylate resin, a (meth) acrylate monomer, a radical initiator, conductive particles, a phenoxy resin, a rubber resin, and an organic solvent.

The present invention also provides a method for preparing a coating composition, comprising: a) preparing a coating composition by mixing an acrylate resin, a (meth) acrylate monomer, a radical initiator, a conductive particle, a phenoxy resin, a rubber resin, and an organic solvent; b) applying the coating composition onto a release film; And c) drying the applied coating composition. The present invention also provides a method for producing an anisotropic conductive film.

Hereinafter, the present invention will be described in more detail.

In the present specification, '(meth) acrylate' is used to collectively mean 'methacrylate' and 'acrylate'.

The anisotropic conductive film of the present invention comprises an acrylate resin, a (meth) acrylate monomer, a radical initiator, a conductive particle, a phenoxy resin and a rubber resin, more preferably 10 to 40 parts by weight of an acrylate resin, ) Acrylate monomer, 1 to 10 parts by weight of a radical initiator, 1 to 10 parts by weight of a conductive particle, 10 to 50 parts by weight of a phenoxy resin, and 10 to 40 parts by weight of a rubber resin.

If the content of the acrylate resin is less than 10 parts by weight, the bubbles between the wires can not be sufficiently pushed out. If the content of the acrylate resin is more than 40 parts by weight, the film may be damaged. The content of the acrylate resin is more preferably 15 to 35 parts by weight.

When the content of the (meth) acrylate monomer is less than 1 part by weight, sufficient reactivity is not obtained and a sufficient molecular weight as a conductive adhesive can not be obtained. When the content is more than 10 parts by weight, Lt; / RTI >

If the amount of the radical initiator is less than 1 part by weight, the reaction is difficult to initiate. If the amount is more than 10 parts by weight, the bonding strength may be deteriorated due to an instantaneous reaction. The content of the radical initiator is more preferably 2 to 5 parts by weight.

If the content of the conductive particles is less than 1 part by weight, it is difficult to obtain a low connection resistance. If the amount is more than 10 parts by weight, shot due to adhesion of the electroconductive particles may occur.

If the content of the phenoxy resin is less than 10 parts by weight, the adhesive strength and the connection resistance may be lowered due to the decrease in heat resistance and moisture resistance. If the content is more than 50 parts by weight, the coating film may become hard, have. The content of the phenoxy resin is more preferably 15 to 40 parts by weight.

When the content of the rubber resin is less than 10 parts by weight, the anisotropic conductive film may be damaged due to impact upon compression. When the amount exceeds 40 parts by weight, heat resistance and moisture resistance of the insulating adhesive layer are difficult to maintain. The content of the rubber resin is more preferably 15 to 35 parts by weight.

The above-mentioned acrylate resin, (meth) acrylate monomer, radical initiator, and conductive particles are components of a conventional low temperature fast curing type anisotropic conductive film. The phenoxy resin and the rubber resin reinforce moisture resistance and heat resistance of the anisotropic conductive film .

The acrylate resin is preferably at least one selected from the group consisting of bisphenol A-based or F-based epoxy acrylate resin, urethane acrylate resin, and polyester acrylate resin having two or more functional groups.

 The (meth) acrylate monomer may be selected from the group consisting of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, tricyclodecane dimethanol dimethacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobornyl acrylate At least one member selected from the group consisting of acryloyloxyethyl succinate, phenoxyethylene glycol acrylate, phenoxyethyl acrylate, urethane monoacrylate, polyethylene glycol diacrylate, and methoxyethylene glycol acrylate .

The radical initiator is preferably a peroxides which are activated by radicals by heating, more preferably peroxides (ROOR '), hydroperoxides (ROOH), or a mixture thereof.

Preferable examples of the peroxide compound include benzoylperoxide, lauroylperoxide, diacetylperoxide, t-butylperoxide, and hydroperoxide, and the hydroperoxide Preferred examples of the compound include cumylhydroperoxide and the like.

The radical initiator is more preferably a mixture of lauroyl peroxide and benzoyl peroxide. In some cases, diacetyl peroxide, t-butyl peroxide, hydroperoxide, cumyl peroxide and the like may be mixed and used.

The conductive particles are preferably at least one selected from the group consisting of nickel particles, gold-plated nickel particles, gold-plated resin particles, silver particles, copper particles and aluminum particles, and the particle diameter of the conductive particles is preferably 2 to 10 μm Do.

The phenoxy resin is preferably a bisphenol A phenoxy resin containing a repeating unit represented by the following formula (1).

[Chemical Formula 1]

In the above formula, n is an integer of 25 to 60.

The phenoxy resin preferably has a number average molecular weight of 7,000 to 17,000 g / mol, and preferably has a glass transition temperature of 80 to 100 ° C.

The rubber resin is preferably a resin composition comprising a butyl acrylate-ethyl acrylate-acrylonitrile rubber having an epoxy group at its end, an ethylene resin, a butyl rubber resin, a butadiene resin, an acrylonitrile butadiene copolymer and a silicone rubber- It is preferable to use at least one species selected from the group consisting of

The thickness of the anisotropic conductive film of the present invention may be variously selected depending on the type of module and electrode used, and is not particularly limited, but it is preferable that the anisotropic conductive film for display has a thickness of 10 to 45 μm.

In addition, the anisotropic conductive film of the present invention has a fast reaction time of 7 to 10 seconds even at a low temperature of 140 to 160 캜.

The anisotropic conductive film of the present invention was obtained by placing an anisotropic conductive film between TCP (pitch: 250 mu m, manufactured by STEMCO) and ITO glass and pressing at a pressure of 2 MPa for 10 seconds at a temperature of 150 DEG C, cm, preferably 1000 to 2000 gf / cm.

It is also preferable that the anisotropic conductive film has a rate of change in adhesive strength represented by the following formula (1): 30% or less.

[Equation 1]

Bond strength change rate (%) = (F ₀ - F ₁₀₀₀ ) / F ₀ × 100

In the above formula (1), F ₀ is an adhesive strength measured after positioning an anisotropic conductive film between TCP (pitch 250 μm, product of STEMCO) and ITO glass and pressing at a temperature of 150 ° C. for 10 seconds at a pressure of 2 MPa , And F ₁₀₀₀ is the bonding strength after 1000 hours of aging at 85 RH and 85 캜.

The anisotropic conductive film of the present invention preferably has a room temperature connection resistance of 3 Ω or less at the time of compression at a temperature of 150 캜 for 10 seconds under a pressure of 2 MPa, and preferably has a connection resistance change rate represented by the following formula (2)

&Quot; (2) "

Connection resistance change rate (%) = (R ₁₀₀₀ - R ₀ ) / R ₀ 100

In the formula (2), R ₀ is a connection resistance measured after placing an anisotropic conductive film between TCP (pitch 250 μm, manufactured by STEMCO) and ITO glass and pressing the film at a temperature of 150 ° C. for 10 seconds at a pressure of 2 MPa , And R ₁₀₀₀ is the connection resistance after 1000 hours aging at 85 RH% and 85 캜.

The anisotropic conductive film of the present invention may further comprise an epoxy resin, if necessary, and preferably at least one selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, and a phenol novolak resin .

The anisotropic conductive film of the present invention may further include at least one additive selected from the group consisting of a reaction promoter, a silane coupling agent, a rubber-modified resin, an adhesion promoter having an epoxy group, and a wetting and dispersing agent. Since the additive is ordinarily used in the art, its content is not particularly limited and may be appropriately selected depending on the application.

Further, since the anisotropic conductive film of the present invention has poor shape-retaining characteristics before the curing reaction, the anisotropic conductive film may further include a release film attached to one or both sides of the anisotropic conductive film. The release film is a part to be removed at the time of mounting, and is not particularly limited, but a polyester film is preferable.

The process for producing an anisotropic conductive film according to the present invention comprises the steps of: a) 10 to 40 parts by weight of an i) acrylate resin, ii) 1 to 10 parts by weight of a (meth) acrylate monomer, iii) 1 to 10 parts by weight of a radical initiator, iv) 1 to 10 parts by weight of particles, v) 10 to 50 parts by weight of a phenoxy resin, vi) 10 to 40 parts by weight of a rubber resin, vii) 40 to 60 parts by weight of an organic solvent to prepare a coating composition; b) applying the coating composition onto a release film; And c) drying the applied coating composition.

The organic solvent is not particularly limited and can be any one as long as it is usually used for an anisotropic conductive film to facilitate adhesion and uniformity of the anisotropic conductive film. However, it is preferable that the organic solvent is toluene, methyl ethyl ketone, ethyl acetate, or a mixture of two or more thereof.

In addition, the step of preparing the coating composition may be prepared by further adding an epoxy resin, if necessary, and is preferably selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, and a phenol novolak resin May be further added.

In addition, the step of preparing the coating composition may further include at least one additive selected from the group consisting of a reaction promoter, a silane coupling agent, a rubber-modified resin, an epoxy resin-containing adhesion promoter, and a wetting and dispersing agent. Since the additive is ordinarily used in the art, its content is not particularly limited and may be appropriately selected depending on the application.

In the above production method, the kinds and content of each component are the same as those described above, and a detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only a preferred embodiment of the present invention, and the present invention is not limited by the following examples.

[Example]

Example 1

2 parts by weight of a radical initiator containing benzoyl peroxide and lauroyl peroxide in a weight ratio of 1: 1, 25 parts by weight of bifunctional epoxy acrylate, 25 parts by weight of phenoxyethylene glycol acrylate (SHIN-NAKAMURA 3.3 parts by weight of polyethylene glycol diacrylate (product of SHIN-NAKAMURA CHEMICAL), 2.5 parts by weight of gold-plated resin particles having an average particle diameter of 10 mu m, 20 parts by weight of PKHH (manufactured by Inchem Corporation) 30 parts by weight of ethyl acrylate-butyl acrylate-acrylonitrile rubber resin were mixed with 30 parts by weight of methyl ethyl ketone and 20 parts by weight of toluene, and the mixture was stirred for 40 minutes to prepare a coating composition.

The coating composition prepared above was applied onto a polyethylene terephthalate release film and dried at 70 캜 to produce an anisotropic conductive film having a thickness of 25 탆.

Example 2

An anisotropic conductive film was produced in the same manner as in Example 1, except that the phenoxy resin content was changed to 30 parts by weight and the rubber resin content was changed to 20 parts by weight.

Example 3

An anisotropic conductive film was produced in the same manner as in Example 1 except that the content of the phenoxy resin was changed to 40 parts by weight and the content of the rubber resin was changed to 15 parts by weight.

Comparative Example 1

An anisotropic conductive film was produced in the same manner as in Example 1, except that the content of the phenoxy resin was changed to 50 parts by weight and the content of the rubber resin was changed to 5 parts by weight.

Comparative Example 2

An anisotropic conductive film was produced in the same manner as in Example 1, except that the content of the phenoxy resin was changed to 60 parts by weight and no rubber resin was added.

Comparative Example 3

An anisotropic conductive film was produced in the same manner as in Example 1, except that the content of the phenoxy resin was changed to 5 parts by weight and the content of the rubber resin was changed to 50 parts by weight.

Comparative Example 4

Except that 30 parts by weight of bifunctional epoxy acrylate and 45 parts by weight of bisphenol A type epoxy resin YD-019 (Kukdo Chemical Co., Ltd.) were added without adding phenoxy resin and rubber resin , An anisotropic conductive film was prepared in the same manner as in Example 1.

Table 1 shows the blending ratios of Examples 1 to 3 and Comparative Examples 1 to 4.

[Table 1]

Unit (parts by weight) Example Comparative Example One 2 3 One 2 3 4 Acrylate resin 25.0 25.0 25.0 25.0 25.0 25.0 30.0 Epoxy resin - - - - - - 45.0 Phenoxy resin 20 30 40 50 60 5 - Rubber resin 30 20 15 5 - 50 - Acrylate monomer 5.5 5.5 5.5 5.5 5.5 5.5 5.5 peroxide 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Conductive particle 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Methyl ethyl ketone 30 30 30 30 30 30 30 toluene 20 20 20 20 20 20 20 system 135 135 140 140 145 140 135

(Evaluation of Adhesive Strength)

The anisotropic conductive films prepared according to Examples 1 to 3 and Comparative Examples 1 to 4 were pressed between TCP (pitch 250 탆, manufactured by STEMCO) and an ITO glass substrate, and then pressed at 150 캜 at a pressure of 2 MPa For 10 seconds to prepare specimens.

After cutting the TCP (pitch 250 μm, manufactured by STEMCO) into 10 mm width, pulling it at a rate of 50 mm / min in a direction of 90 ^° (Y axis) at room temperature using a Tensilon machine (Simazu, Auto Graph, Japan) The adhesive strength (F ₀ ) was measured and the results are summarized in Table 2 below.

(Evaluation of adhesive strength reliability)

The adhesive strength (F ₁₀₀₀ ) was measured in the same manner as in the evaluation of the adhesive strength, except that the specimen produced in the evaluation of the adhesive strength was aged for 1000 hours under the condition of 85 캜 x 85% RH. The rate of change of the adhesive strength was calculated. The bond strength change rates are summarized in Table 2 below.

(Evaluation of connection resistance)

A current of 1 mA was applied between a TCP and an ITO electrode of a prepared specimen at the time of evaluating the bonding strength with a multimeter (Keithley, Model 2000), and a connection resistance (R ₀ ) between the TCP and the ITO electrode was measured. The results are summarized in Table 2 below.

(Evaluation of Connection Resistance Reliability)

The connection resistance (R ₁₀₀₀ ) was measured in the same manner as in the evaluation of the connection resistance, except that the specimen produced during the evaluation of the bonding strength was aged for 1000 hours under the condition of 85 캜 x 85% RH. 2, the change rate of the connection resistance was calculated. The connection resistance change rates are summarized in Table 2 below.

(Surface Shrinkage Rate Evaluation)

The anisotropic conductive films prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were made into samples of 3 cm × 3 cm in length and aged at 85 ° C. × 85% RH for 100 hours, The shrinkage of the insulating adhesive layer was confirmed.

Fig. 1 is a photograph showing the shrinkage state of the anisotropic conductive film produced according to Examples 1 to 3 and Comparative Examples 1 to 4, in which shrinkage-free samples and shrinkage- Respectively.

[Table 2]

Example Comparative Example One 2 3  One 2 3 4 F ₀ (gf / cm) 1503 1520 1582 1238 1021 998 1339 F ₁₀₀₀ (gf / cm) 1092 1207 1318 870 451 591 704 Bond strength change rate (%) 27.4 20.5 16.7 29.7 55.8 40.7 47.4 R ₀ (Ω) 2.13 2.02 2.28 2.47 3.05 3.11 2.20 R ₁₀₀₀ (Ω) 3.21 2.98 3.39 5.01 7.10 6.97 5.62 Connection resistance change rate (%) 50.7 47.5 48.7 102.8 132.8 124.1 155.5 Surface contraction ○ ○ ○ ○ ○ X X

As shown in Table 2, the anisotropic conductive films prepared according to Examples 1 to 3 of the present invention had no surface shrinkage even after being left in a high temperature and high humidity condition for a long time, It can be seen that the bonding strength and the stability of the connection resistance are excellent even in high humidity.

On the other hand, the anisotropic conductive film of Comparative Example 1, to which a large amount of phenoxy resin was added, and the anisotropic conductive film of Comparative Example 2, to which no rubber resin was added, provided a stable contact area between TCP and ITO glass, The adhesive strength is lowered at the time of pressing, and it is difficult to press the conductive particles, so that the reliability is low at high temperature / high humidity against connection resistance.

In addition, the anisotropic conductive film of Comparative Example 3 in which a small amount of phenoxy resin was added and a large amount of rubber resin was added caused a phenomenon that the anisotropic conductive film was pushed out between the TCP and the ITO glass upon compression, and the reliability in high temperature / The evaluation showed that the shrinkage occurred and the bond strength and the change rate of the connection resistance were large.

In addition, in the case of Comparative Example 4 in which an epoxy resin was added, the adhesive strength at room temperature was high, but shrinkage occurred in the reliability evaluation under high temperature / high humidity conditions, and the adhesive strength and the rate of change in connection resistance were large.

 The anisotropic conductive film of the present invention includes a phenoxy resin and a rubber resin having high heat resistance and moisture resistance and causes a rapid curing reaction at a low temperature and exhibits an adhesive strength and an adhesive strength at a high temperature and high humidity condition (85 캜 x 85% RH) There is an advantage that the effect of maintaining the connection reliability is excellent and the shrinkage phenomenon is improved.

Claims (7)

a) 10 to 40 parts by weight of an acrylate resin, b) 1 to 10 parts by weight of a (meth) acrylate monomer, c) from 1 to 10 parts by weight of a radical initiator, d) 1 to 10 parts by weight of conductive particles, e) 10 to 50 parts by weight of a phenoxy resin, and f) 10 to 40 parts by weight of a rubber resin ≪ / RTI > The method according to claim 1, E) the phenoxy resin is a bisphenol A-type phenoxy resin containing a repeating unit represented by the following formula (1) [Chemical Formula 1]

In the above formula, n is an integer of 25 to 60. The f) rubber resin is preferably a resin composition comprising a butyl acrylate-ethyl acrylate-acrylonitrile rubber having an epoxy group at the terminal, an ethylene resin, a butyl rubber resin, a butadiene resin, an acrylonitrile butadiene copolymer, ≪ / RTI > The anisotropic conductive film according to claim 2, wherein the phenoxy resin has a number average molecular weight of 7,000 to 17,000 g / mol. The anisotropic conductive film according to claim 1, wherein the anisotropic conductive film has an adhesive strength change rate of 30% [Equation 1] Bond strength change rate (%) = (F ₀ - F ₁₀₀₀ ) / F ₀ × 100 In the equation (1), wherein F ₀ is a bond strength measured after positioning the anisotropic conductive film between the TCP (pitch 250 ㎛) and ITO glass and, 10 seconds pressed at a temperature of 150 ℃ to 2MPa pressure, the F ₁₀₀₀ Is the adhesive strength after 1000 hours of aging under the conditions of 85 RH% and 85 캜. The anisotropic conductive film according to claim 1, wherein the anisotropic conductive film has a room-temperature connection resistance of 3 Ω or less at the time of compression at a pressure of 2 MPa and a temperature of 150 ° C. for 10 seconds. The anisotropic conductive film according to claim 1, wherein the anisotropic conductive film has a change rate of contact resistance represented by the following formula (2): 100% &Quot; (2) " Connection resistance change rate (%) = (R ₁₀₀₀ - R ₀ ) / R ₀ 100 In the above equation (2), wherein R ₀ is TCP (pitch 250 ㎛) and ITO, and placing an anisotropic conductive film between the glass and the connection measured by the 2MPa pressure after the compression at a temperature of 150 ℃ 10 chogan resistance, the R ₁₀₀₀ Is the connection resistance after 1000 hours aging at 85 RH% and 85 캜. a) i) 10 to 40 parts by weight of an acrylate resin, ii) 1 to 10 parts by weight of a (meth) acrylate monomer, iii) 1 to 10 parts by weight of a radical initiator, iv) 1 to 10 parts by weight of conductive particles, v) 10 to 50 parts by weight of a phenoxy resin, and vi) 10 to 40 parts by weight of a rubber resin vii) mixing 40 to 60 parts by weight of the organic solvent to prepare a coating composition; b) applying the coating composition onto a release film; And c) drying the applied coating composition to form an anisotropic conductive film.

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