KR20120036721A - Anisotropic conducting film - Google Patents

Abstract

The present invention relates to an anisotropic conductive film comprising an insulating layer, a conductive layer laminated on the insulating layer and containing conductive particles, wherein the minimum melt viscosity of the conductive layer is greater than the minimum melt viscosity of the insulating layer. .
The anisotropic conductive film of the present invention is configured to include a conductive layer having a high minimum melt viscosity and an insulating layer having a low minimum melt viscosity, thereby preventing short between conductive particles, lowering connection resistance, and providing a thickness of the insulating layer to the conductive layer. By making it thicker and including insulating particles, sufficient adhesion between circuit members is provided, and recognizability is greatly improved.

Description

Anisotropic Conductive Film {ANISOTROPIC CONDUCTING FILM}

The present invention relates to an anisotropic conductive film. More specifically, the present invention includes an insulating layer, a conductive layer laminated on the insulating layer and containing conductive particles, wherein the lowest melt viscosity of the conductive layer is characterized in that the higher than the minimum melt viscosity of the insulating layer It is about.

Anisotropic conducting film (ACF) is a film in which conductive particles such as metal particles such as nickel (Ni) and gold (Au) or polymer particles coated with such metals are dispersed. The axis refers to a film that exhibits electrical conductivity through electricity and an insulation property in the xy plane direction.

When the anisotropic conductive film is placed between the circuits to be connected and subjected to a heating and pressing process under a predetermined condition, the circuit terminals are electrically connected by conductive particles, and the space between adjacent circuits The insulating adhesive resin is filled so that the conductive particles exist independently of each other, thereby providing high insulation. Anisotropic conductive films are generally widely used for liquid crystal display (LCD) panels and tape carrier packages (TCP) or printed circuit boards and TCP for electrical connection.

However, in accordance with the trend of the display industry, which has recently become larger and thinner, the pitch between electrodes and circuits is gradually miniaturized, and the conventional monolayer anisotropic conductive film shows a limitation in connecting such fine circuit terminals.

Accordingly, an anisotropic conductive film having a multi-layer structure has been proposed, but a low melt viscosity of the adhesive layer including conductive particles prevents the conductive particles from being located between circuit terminals and flows into adjacent spaces, causing short or increasing connection resistance. . In addition, there is a problem that does not express sufficient adhesive force between the circuit members, and as the transparency of the insulating adhesive layer containing no conductive particles increases, there is a problem that does not recognize the presence or absence of the film after pressing the anisotropic conductive film to the circuit member have.

One object of the present invention is to provide an anisotropic conductive film which can prevent a short between the conductive particles and lower the connection resistance.

Another object of the present invention is to provide an anisotropic conductive film that provides sufficient adhesion between circuit members and has improved recognition.

One aspect of the present invention relates to an anisotropic conductive film. The anisotropic conductive film includes an insulating layer and a conductive layer stacked on the insulating layer, the conductive layer containing conductive particles, wherein the lowest melt viscosity of the conductive layer is greater than 3,000 Pa.s or more than the minimum melt viscosity of the insulating layer. do.

In embodiments, the lowest melt viscosity of the conductive layer may be 3,000 to 48,000 Pa s greater than the lowest melt viscosity of the insulating layer.

In an embodiment, the lowest melt viscosity of the conductive layer may be 4,000 to 50,000 Pa.s, and the lowest melt viscosity of the insulating layer may be 2,000 to 10,000 Pa.s.

In an embodiment, the insulating layer may be thicker than the conductive layer. More specifically, the thickness ratio of the insulating layer to the conductive layer may be greater than 1 and less than 4.

In an embodiment, the conductive layer or the insulating layer may include insulating particles.

Specifically, the conductive layer or the insulating layer may include 0.1 to 20% by weight of insulating particles based on the entire composition.

In addition, the insulating particle content (% by weight) of the conductive layer with respect to the entire conductive layer composition may be greater than the insulating particle content (% by weight) of the insulating layer with respect to the entire insulating layer composition.

In addition, the conductive layer may include 2 to 20% by weight of insulating particles based on the entire conductive layer composition.

In addition, the insulating layer may include 0.1 to 10% by weight of insulating particles with respect to the entire insulating layer composition.

In an embodiment, the conductive layer may include 1 to 30 wt% of conductive particles based on the entire conductive layer composition.

In an embodiment, the conductive layer or insulating layer composition may include a polymer resin, a radical polymerizable material, and a radical initiator.

Specifically, the polymer resin may be an olefin resin, butadiene resin, acrylonitrile butadiene copolymer, carboxyl terminal acrylonitrile butadiene copolymer, polyimide resin, polyamide resin, polyester resin, polyvinyl buty Ral resin, ethylene-vinylacetate copolymer, styrene-butylene-styrene (SBS) resin, styrene-ethylene-butylene-styrene (SEBS) resin, acrylonitrile butadiene rubber (NBR), urethane resin, It may contain any one or more of (meth) acrylic resin or phenoxy resin.

The conductive layer and the insulating layer may include a polymer resin having a molecular weight of 50,000 to 1 million, wherein the conductive layer is 20 to 20 to the total composition of the conductive layer 60 wt% may be included, and the insulating layer may include 30 to 70 wt% of the polymer resin based on the entire composition of the insulating layer.

The radically polymerizable material may include a (meth) acrylate monomer (oligomer) or a urethane acrylate monomer (oligomer). In addition, the radically polymerizable material may be included in an amount of 20 to 60 wt% with respect to the entire conductive layer or insulating layer composition.

The radical initiator may include any one or more of a photopolymerization initiator or a thermosetting initiator. In addition, the total amount of the conductive layer or the insulating layer may be included in 0.5 to 10% by weight.

In an embodiment, the conductive layer or insulating layer composition may include a silane coupling agent. The silane coupling agent may be included in an amount of 0.1 wt% to 5 wt% with respect to the entire conductive layer or insulation layer composition.

The anisotropic conductive film of the present invention includes an insulating layer and a conductive layer laminated on the insulating layer and containing conductive particles, and after replacing the glass substrate above and below 160 degrees (based on the anisotropic conductive film sensing temperature), 5 seconds, and 3 MPa. When crimping (based on sample area), an area ratio of the insulating layer to the conductive layer after compression may be 1.4 to 3.0.

In embodiments, the lowest melt viscosity of the conductive layer may be greater than the lowest melt viscosity of the insulating layer.

The anisotropic conductive film of the present invention can be configured to include a conductive layer having a high minimum melt viscosity and an insulating layer having a low minimum melt viscosity, thereby preventing a short between the conductive particles and lowering connection resistance.

In addition, the thickness of the insulating layer is thicker than that of the conductive layer, the insulating particles are provided to provide sufficient adhesion between the circuit members, and there is an advantage in that recognizability is greatly improved.

1 is a cross-sectional view of an anisotropic conductive film according to an embodiment of the present invention.
2 is a conceptual diagram for measuring or explaining the lowest melt viscosity of the present invention.
3 is a cross-sectional view for explaining a TAB process using an anisotropic conductive film according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, the following examples are provided to aid the understanding of the present invention, and the scope of the present invention is not limited to the following examples. Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

1 is a cross-sectional view of an anisotropic conductive film according to an embodiment of the present invention. 2 is a conceptual diagram for measuring or explaining the lowest melt viscosity of the present invention. As shown in FIG. 1, the anisotropic conductive film 100 according to an embodiment of the present invention includes an insulating adhesive layer (hereinafter referred to as an “insulating layer”, 102) and a conductive adhesive layer (hereinafter referred to as “conductive layer”, 104).

The anisotropic conductive film 100 according to one embodiment of the present invention is also characterized in that the larger (η _0), the lowest melting point of the conductive layer 104 in comparison to the minimum melt viscosity (η ₀₎ of the insulating layer 102 . In one embodiment, the lowest melt viscosity of the conductive layer 104 may be 3,000 Pa · s or more, preferably 3,000 to 48,000 Pa · s, greater than the lowest melt viscosity of the insulating layer 102. The generation | occurrence | production of the short by the electroconductive particle of a conductive layer can be suppressed in the said melt viscosity difference range, and an insulating layer can flow sufficiently between circuit members, and can exhibit high adhesive force.

In addition, the lowest melt viscosity of the conductive layer 104 may be 4,000 to 50,000 Pa.s, and the lowest melt viscosity of the insulating layer 102 may be 2,000 to 10,000 Pa.s. Short generation by the electroconductive particle of a conductive layer can be suppressed within the said melt viscosity range, and an insulating layer can flow sufficiently between circuit members, and can exhibit high adhesive force.

Referring to FIG. 2, when the viscosity is generally measured while increasing the temperature of the adhesive, the viscosity gradually decreases at an initial stage (A1 section) by increasing the temperature, and at some point (T ₀ ), the adhesive melts to the lowest viscosity. (η ₀ ). After further increasing the temperature, the curing proceeds (A2 section), the viscosity gradually rises, and when the curing is completed (A3 section), the viscosity is generally kept constant. In the present invention, the lowest melt viscosity means viscosity η ₀ at the temperature T ₀ .

Meanwhile, the thickness T ₁ of the insulating layer 102 may be larger than the thickness T ₂ of the conductive layer 104, and preferably, the range of T ₁ / T ₂ is greater than 1 and less than 4. Within this range, the insulating resin can be sufficiently filled between adjacent circuits to show good insulation and adhesion.

Conductive particles 106 are included in the conductive layer 102 of the anisotropic conductive film according to an embodiment of the present invention, the conductive particles 106 will be described later. Meanwhile, the conductive layer 104 and / or the insulating layer 102 may further include insulating particles 108 to be described later. The size (average particle diameter) of the insulating particles 108 is smaller than that of the conductive particles 106. It is preferable.

3 is a cross-sectional view illustrating a tape automated bonding (TAB) process using an anisotropic conductive film according to an embodiment of the present invention. Referring to FIG. 3, a TAB process of connecting a Tape Carrier Package (TCP) to an anisotropic conductive film by mounting a driving IC (Integrated Circuit) on an LCD panel is mainly used. For this purpose, a circuit of the TCP 200 is used. After the terminal 202 and the electrode 302 of the LCD panel 300 are aligned, the anisotropic conductive film 100 is interposed therebetween and then subjected to heat compression.

At the time of hot pressing, the insulating layer 102 of the anisotropic conductive film 100 according to the embodiment of the present invention has a low viscosity and has high fluidity so that the circuit terminal 202 and the electrode 302 do not face each other. In order to flow mainly, the matrix of the conductive layer 104 having high viscosity and low fluidity and the conductive particles 106 are mainly positioned between the circuit terminal 202 and the electrode 302 to be compressed. In other words, the leakage of the conductive particles 106 is small in the side spaces in which the circuit terminals 202 and the electrodes 302 do not face each other, thereby preventing short circuits. In addition, the insulating particles 108 may be located between the conductive particles 106 to further prevent the short between the conductive particles 106 and to lower the transparency of the anisotropic conductive film to improve recognition.

In addition, since the viscosity of the insulating layer 102 is low and fluidity is large, the area after the pressing may be larger than that of the conductive layer 104. Specifically, the glass substrate is replaced up and down, and then pressed at 160 degrees (based on the sensing temperature of the anisotropic conductive film), 5 seconds, and 3 MPa (based on the sample area), based on the outermost particles (the conductive particles and the insulating particles). It is preferable that the area ratio after crimping of the insulating layer to the conductive layer is 1.4 to 3.0 (the insulating layer area after the crimp / the conductive layer area after the crimp = 1.4 to 3.0).

Hereinafter, a composition for manufacturing an anisotropic conductive film according to an embodiment of the present invention will be described. Preparation of the insulating layer and the conductive layer constituting the anisotropic conductive film according to an embodiment of the present invention may include a polymer resin, a radical polymerizable material, a radical initiator, conductive particles, insulating particles, coupling agents and other additives. .

(a) polymer resin

As the polymer resin serving as a matrix of the film, a thermoplastic resin, a thermosetting resin, or a combination thereof may be used. Although there is no limitation on the polymer resin, for example, an olefin resin, a butadiene resin, an acrylonitrile butadiene copolymer, a carboxyl terminal acrylonitrile butadiene copolymer, a polyimide resin, including polyethylene, polypropylene, etc. Polyamide resin, polyester-based resin, polyvinyl butyral resin, ethylene-vinylacetate copolymer, styrene-butyrene-styrene (SBS) resin, styrene-ethylene-butylene-styrene (SEBS) resin, Any one or more of acrylonitrile butadiene rubber (NBR), urethane resin, (meth) acrylic resin, and phenoxy resin can be used.

In order to control the minimum melt viscosity of the conductive layer and the insulating layer of the polymer resin, it is preferable to use a polymer resin having a molecular weight of 50,000 to 1 million. The conductive layer preferably contains 20 to 60% by weight of a polymer resin having a molecular weight of 50,000 to 1 million with respect to the entire composition of the conductive layer, and the insulating layer is a polymer resin having a molecular weight of 50,000 to 1 million to the entire insulation layer composition It is preferable to include 10 to 40% by weight relative to. In addition, the content of the polymer resin having a molecular weight of 50,000 to 1 million in the two layers is preferably in the insulating layer polymer resin weight% / conductive layer polymer resin weight% <1, the conductive particles in the above range is the circuit terminal It can be located at, and short circuit protection and connection resistance can be lowered.

On the other hand, the polymer resin may include an epoxy resin, the epoxy resin may have a role of ensuring the adhesion and connection reliability between the connection layer is a curing reaction occurs. The epoxy resin is not limited and may include at least one epoxy resin of bisphenol type, novolak type, glycidyl type, aliphatic and alicyclic. Moreover, the epoxy resin which is solid at normal temperature and the epoxy resin which is liquid at normal temperature can be used together, and a flexible epoxy resin can be used together further. Examples of the solid epoxy resin include a phenol novolac epoxy resin, a cresol novolac epoxy resin, and an epoxy resin mainly composed of dicyclo pentadiene and bisphenol A. Or an F-type polymer or a modified epoxy resin, but is not necessarily limited thereto. As the liquid epoxy resin at room temperature, bisphenol A or F or mixed epoxy resin may be used. It is not limited to this. Examples of the flexible epoxy resin include dimer acid-modified epoxy resins, epoxy resins based on propylene glycol, urethane-modified epoxy resins, and the like.

 (b) Radical Polymerizable  matter

The radically polymerizable material is a component of the hardened part, and a radical hardening reaction occurs to ensure adhesion and connection reliability between the connection layers. The radically polymerizable material of the anisotropic conductive film composition according to the embodiment of the present invention may include any one or more of (meth) acrylate oligomer or (meth) acrylate monomer, but the present invention is not limited thereto.

(b-1) ( Meta ) Acrylate Oligomer

As the (meth) acrylate oligomer, one or more oligomers selected from the group of known (meth) acrylate oligomers can be used without limitation, and preferably, urethane-based (meth) acrylate, epoxy-based (meth) acrylate, poly Ester (meth) acrylate, fluorine (meth) acrylate, fluorene (meth) acrylate, silicone (meth) acrylate, phosphoric acid (meth) acrylate, maleimide modified (meth) acrylate, acrylate Oligomers, such as (methacrylate), can be used individually or in combination of 2 or more types, respectively.

Specifically, the urethane-based (meth) acrylates of the molecular structure of the polyester polyol (polyester polyol), polyether polyol (polyether polyol), polycarbonate polyol (polycarbonate polyol), polycaprolactone polyol (polycarprolactone polyol), ring Ring-opening tetrahydrofurane-propyleneoxide ring opening copolymer, polybutadiene diol, polydimethylsiloxane diol, ethylene glycol, propylene glycol, 1, 4-butanediol (1,4-butanediol), 1,5-pentanediol (1,5-pentanediol), 1,6-hexanediol (1,6-hexanediol), neopentyl glycol, 1,4 1,4-cyclohexane dimethanol, bisphenol A, hydrogenated bisphenol A, 2,4-toluene diisocyanate, 1, 3-character 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate, 1,6-hexane What is synthesize | combined from diisocyanate (1, 6-hexan diisocyanate) and isophorone diisocyanate can be used.

As said epoxy (meth) acrylate type, the intermediate molecular structure is bisphenol, such as 2-bromohydroquinone, resorcinol, catechol, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, 4,4'- dihydride Consisting of an alkyl group, an aryl group, a methylol group, an allyl group, a cyclic aliphatic group, a halogen (such as tetrabromobisphenol A), a nitro group, or the like having a skeleton such as oxybiphenyl or bis (4-hydroxyphenyl) ether ( The thing chosen from the group of the meta) acrylate oligomers can be used, In addition, the (meth) acrylate oligomer of this invention which contains at least 2 or more maleimide groups in a molecule | numerator, for example, 1-methyl-2,4- Bismaleimide benzene, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide, N, N'-m- toylene bismaleimide, N, N'-4 , 4-biphenylenebismaleimide, N, N'-4,4- (3,3'-dimethyl ratio Nylene) bismaleimide, N, N'-4,4- (3,3'-dimethyl diphenyl methane) bismaleimide, N, N'-4,4- (3,3'-diethyl diphenyl methane ) Bismaleimide, N, N'-4,4-diphenylmethanebismaleimide, N, N'-4,4-diphenylpropanebismaleimide, N, N'-4,4-diphenyletherbis Maleimide, N, N'-3,3'- diphenyl thrubis bismaleimide, 2, 2-bis (4- (4-maleimide phenoxy) phenyl) propane, 2, 2-bis (3-s- Butyl-4-8 (4-maleimide phenoxy) phenyl) propane, 1,1-bis (4- (4-maleimide phenoxy) phenyl) decane, 4,4'- cyclohexyridene bis (1 -(4 maleimide phenoxy) -2-cyclohexyl benzene, 2,2-bis (4- (4 maleimide phenoxy) phenyl) hexafluoro propane, etc. can be used individually or in combination of 2 or more types, respectively.

 (b-2) ( Meta ) Acrylate Monomer

The radical curable type composition according to the embodiment of the present invention may include (meth) acrylate monomer, which is also a radical polymerizable material, as another component of the hardening part.

As the (meth) acrylate, one or more monomers selected from the group of known (meth) acrylate monomers can be used without limitation, although not particularly limited, preferably 1,6-hexanediol mono (meth) acryl Latex, 2-hydroxy ethyl (meth) acrylate, 2-hydroxy propyl (meth) acrylate, 2-hydroxy butyl (meth) acrylate, 2-hydroxy-3-phenyl oxypropyl (meth) acrylate To 1,4-butanediol (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxy cyclohexyl (meth) acrylate, neopentylglycol mono (meth) acrylate, trimethylol Pandi (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerys Tall hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin di (meth) acrylate, t-hydroperfuryl (meth) acrylate, iso-decyl (meth) acrylate, 2- ( 2-ethoxyethoxy) ethyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, tri Decyl (meth) acrylate, ethoxy addition type nonylphenol (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, t-ethylene Glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethoxy addition type bisphenol-A di (meth) Acryl , Cyclohexane dimethanol di (meth) acrylate, phenoxy-t-glycol (meth) acrylate, 2-methacryloyloxyethyl phosphate, dimethylol tricyclo decane di (meth) acrylate, trimethylol One or more types selected from the group consisting of propanebenzoate acrylate, fluorene-based (meth) acrylate and mixtures thereof can be used.

The radically polymerizable material is based on the entire conductive layer or the insulating layer composition. 20 to 60% by weight may be included. It is possible to exhibit good reliability, good contact characteristics between the conductive particles and the circuit substrate during adhesion, good connection resistance, and good adhesion characteristics in the above range after the process crimping.

(c) Radical Initiator

A radical initiator can use 1 or more types of photoinitiators or a thermosetting initiator. Specific examples of the photopolymerization initiator include benzophenone, methyl o-benzoyl benzoate, 4-benzoyl-4-methyl diphenyl sulfide, isopropyl thioxanthone, diethyl thioxanthone, 4-diethyl ethyl benzoate, benzoin ether , Benzoyl propyl ether, 2-hydroxy-2-methyl-1-phenyl propane-1-one, diethoxy acetophenone, and the like.

As the thermosetting initiator, peroxide and azo may be used. Specific examples of the peroxide initiator include t-butyl peroxylaurate, 1,1,3,3-t-methylbutylperoxy-2-ethyl hexanonate, 2,5-dimethyl-2,5-di (2-ethylhexanoyl peroxy) hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethyl hexanonate, 2,5-dimethyl-2,5-di (m-toluoyl peroxy) hexane , t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxy benzoate, t-butyl peroxy acetate, dicumyl peroxide, 2,5, -dimethyl -2,5-di (t-butyl peroxy) hexane, t-butyl cumyl peroxide, t-hexyl peroxy neodecanoate, t-hexyl peroxy-2-ethyl hexanonate, t-butyl peroxy -2-2-ethylhexanoate, t-butyl peroxy isobutylate, 1,1-bis (t-butyl peroxy) cyclohexane, t-hexyl peroxy isopropyl monocarbonate, t-butyl peroxy 3,5,5-trimethyl hexanonate, t -Butyl peroxy pivalate, cumyl peroxy neodecanoate, di-isopropyl benzene hydroperoxide, cumene hydroperoxide, isobutyl peroxide, 2,4-dichloro benzoyl peroxide, 3,5,5-trimethyl Hexanoyl peroxide, octanoyl peroxide, lauryl peroxide, stearoyl peroxide, succinic peroxide, benzoyl peroxide, 3,5,5-trimethyl hexanoyl peroxide, benzoyl peroxy toluene, 1,1, 3,3-tetramethyl butyl peroxy neodecanoate, 1-cyclohexyl-1-methyl ethyl peroxy nodecanoate, di-n-propyl peroxy dicarbonate, di-isopropyl peroxy carbonate, bis (4-t-butyl cyclohexyl) peroxy dicarbonate, di-2-ethoxy methoxy peroxy dicarbonate, di (2-ethyl hexyl peroxy) dicarbonate, dimethoxy butyl peroxy dicarbonate, di (3 -Methyl-3-methoxy Tyl peroxy) dicarbonate, 1,1-bis (t-hexyl peroxy) -3,3,5-trimethyl cyclohexane, 1,1-bis (t-hexyl peroxy) cyclohexane, 1,1-bis (t-butyl peroxy) -3,3,5-trimethyl cyclohexane, 1,1- (t-butyl peroxy) cyclododecane, 2,2-bis (t-butyl peroxy) decane, t-butyl Trimethyl silyl peroxide, bis (t-butyl) dimethyl silyl peroxide, t-butyl triallyl silyl peroxide, bis (t-butyl) diallyl silyl peroxide, tris (t-butyl) aryl silyl peroxide, and the like. .

Specific examples of the azo initiator include 2,2'-azobis (4-methoxy-2,4-dimethyl valeronitrile), dimethyl 2,2'-azobis (2-methyl propionate), 2, 2'-azobis (N-cyclohexyl-2-methyl propionide), 2,2-azobis (2,4-dimethyl valeronitrile), 2,2'-azobis (2-methyl butyronitrile ), 2,2'-azobis [N- (2-propenyl) -2-methylpropionide], 2,2'-azobis (N-butyl-2-methyl propionide), 2,2 '-Azobis [N- (2-propenyl) -2-methyl propionide], 1,1'-azobis (cyclohexane-1-carbonitrile), 1-[(cyano-1-methylethyl ) Azo] formamide, and the like, but is not limited thereto.

The initiators may be used by mixing one or more kinds. The content of the radical initiator is determined in a range that balances the property to be cured in the adhesive and the preservation of the adhesive, and may be included in an amount of 0.5 to 10 wt% based on the entire conductive layer or the insulating layer composition of the present invention. In the above range, it is possible to exhibit excellent main compression characteristics according to a good curing reaction rate, and anisotropic conductive film can be satisfactorily removed during rework.

(d) conductive particles

The conductive particles of the present invention are dispersed in the insulating adhesive and serve to electrically connect the member to be connected, and are included in the conductive layer. As said electroconductive particle, the conventionally well-known electroconductive particle can be used without a restriction | limiting. For example, metal particles containing Au, Ag, Ni, Cu, Pb, etc., carbon particles, particles coated with metal on polymer resin or particles coated with metal on polymer resin can be used. Can be. The polymer resin may be polyethylene, polypropylene, polyester, polystyrene, polyvinyl alcohol and the like, but the present invention is not limited thereto. Examples of the metal coating the polymer resin include Au, Ag, Ni, Cu, and Pb, but the present invention is not limited thereto.

Specifically, in the case of outer lead bonding (OLB), since the adherend is an indium tin oxide (ITO) glass surface, the core part is made of a plastic component so that the core is not damaged by the pressure generated in the connection process of the anisotropic conductive film. Particles may be used, and metal particles such as Ni may be used to connect PCB substrates, and in the case of plasma display panels (PDPs), the voltage applied to the circuit is very high. ) Can be used to plate the conductive particles, in the case of COG (Chip On Glass) or a narrow pitch on the COF (Chip On Film) can be used for insulating conductive particles coated with a thermoplastic resin on the surface of the conductive particles.

The size of the said electroconductive particle can be selected and used according to a use in 1-30 micrometers, Preferably it is 3-20 micrometers by the pitch of the circuit to apply. On the other hand, the conductive particles may be contained 1 to 30% by weight based on the entire conductive layer composition of the anisotropic conductive film. It is possible to secure a stable connection reliability within the above range, it is possible to prevent the electrical short caused by the aggregation of the conductive particles between the pitch during thermocompression.

 (e) insulating particles

The insulating particles may be inorganic particles, organic particles, or organic / inorganic mixed particles, and may be included in any one or more of the insulating layer and the conductive layer. The insulating particles impart recognizability to the anisotropic conductive film and provide a short between the conductive particles. It can prevent.

Examples of inorganic particles include silica, SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZnO, MgO, ZrO ₂ , PbO, Bi ₂ O ₃ , MoO ₃ , V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , WO ₃ Alternatively, at least one selected from In ₂ O ₃ may be a ceramic particle, but the present invention is not limited thereto. Examples of the organic particles include acrylic beads, and may be organic / inorganic mixed particles in which an organic material is coated on the surface of the inorganic particles.

Specific examples of the use of the inorganic particles include silica, and the silica may be a silica produced by a liquid phase method such as a sol gel method or a precipitation method, or a silica produced by a gas phase method such as a flame oxidation method. The pulverized non-powder silica may be used, or fused silica may be used, and the shape thereof is not limited such as spherical, crushed, and edgeless. Fused silica includes natural silica glass made by melting natural crystal or silica with arc (flame) discharge or oxyhydrogen flame, and synthetic silica glass which synthesizes gaseous materials such as silicon tetrachloride or silane by pyrolysis in oxyhydrogen flame or oxygen plasma. It may include any one or more of.

Since the insulating particles have a larger size (average particle diameter) than the conductive particles, it may cause problems in energization. Therefore, the insulating particles are preferably smaller in size than the conductive particles. It can be selected according to the use. The insulating particles may be included in an amount of 0.1 to 20% by weight based on the entire conductive layer or the insulating layer composition of the anisotropic conductive film, but the present invention is not limited thereto and may not include the insulating particles.

Looking at the insulating particle content of the conductive layer and the insulating layer, it is preferable that the insulating particle content (% by weight) of the conductive layer with respect to the entire conductive layer composition is larger than the insulating particle content (% by weight) of the insulating layer with respect to the entire insulating layer composition. Do. Specifically, the conductive layer may include 2 to 20% by weight of insulating particles based on the entire conductive layer composition, and the insulating layer may include 0.1 to 10% by weight of insulating particles based on the entire insulating layer composition.

(f) Coupling agent

In the present invention, a coupling agent that serves to improve connection reliability by improving adhesion, heat resistance, and moisture resistance between the surface of the inorganic material and the anisotropic conductive film when compounding the composition may be used. The coupling agent may be preferably added in an amount of 0.1 to 5% by weight, preferably 0.1 to 2% by weight, based on the total amount of the conductive layer or the insulating layer. It can prevent.

The coupling agent may be a commonly used silane coupling agent, for example, epoxy-containing 2- (3,4 epoxy cyclohexyl) -ethyltrimethoxysilane, 3-glycidoxytrimethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2 (aminoethyl) 3-amitopropylmethyldimethoxysilane containing amine group, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N- 2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysil-N- (1,3-dimethylbutylidene ) Propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane with mercapto, 3-mercaptopropyltriethoxysilane, 3-isocyanatepropyl with isocyanate Triethoxysilane and the like, and these may be used alone or in combination of two or more thereof. have.

(g) other additives

The composition for anisotropic conductive films (conductive layer, insulating layer) of the present invention is a content known in the art other additives such as polymerization inhibitors, antioxidants, heat stabilizers, etc. in order to add additional physical properties without impairing the basic physical properties It may further include a range.

Example  And Comparative example

The invention can be better understood by the following examples and comparative examples (see Table 1), the following examples are for the purpose of illustration of the invention and the scope of protection defined by the appended claims It is not intended to be limiting.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Isolation challenge Isolation challenge Isolation challenge Isolation challenge Isolation challenge Polymer resin Nipol 1072 - 10 - 10 - 10 10 - - 10 D-ACE-540T 40 10 40 10 40 10 10 40 40 10 E4275 10 25 10 25 10 25 33 2 5 20 Radically polymerizable material
Epoxy (meth) acrylate 40 30 40 30 40 30 30 40 45 40 2-methacryloyloxyethyl phosphate 2 2 2 2 2 2 2 2 2 2 Pentaerythritol tri (meth) acrylate 3 8 3 8 3 8 8 3 3 8 2-hydroxyethyl (meth) acrylate 3 - 2 - 3 - - 3 3 - Radical initiator Benzoyl peroxide 2 - 2 - 2 - - 2 2 - Lauryl peroxide - 2 - 2 - 2 2 - - 2 Conductive particles Nickel powder - 8 - 8 - 8 - 8 - 8 Insulating particles Silica - 5 - 5 - 5 5 - - - Coupling agent 3-glycidoxypropyltriethoxysilane - - One - - - - - - - Film thickness (㎛) 25 10 25 10 10 25 25 10 25 10 Minimum melt viscosity
(kPa? s) 2 7 2 7 2 7 9 2 1.5 4

Example  One

Dissolve 40% by weight of urethane-based resin (D-ACE-540T, Dynamic Chemical) in toluene with 50% solids, and 10% by weight of phenoxy resin (E4275, Zepene epoxy resin) in MEK (Methyl Ethyl Ketone) 40 wt% epoxy (meth) acrylate (SP1509, Shohwa polymer), 2 wt% 2-methacryloyloxyethyl phosphate, 3 wt% pentaerythritol tri (meth) acrylate, 2-hydroxyethyl Using 3% by weight of (meth) acrylate and 2% by weight of benzoyl peroxide, an insulating adhesive layer having a thickness of 25 μm and a minimum melt viscosity of about 2,000 (Pa · s) was formed.

10% by weight of acrylonitrile butadiene resin (Nipol 1072, Nippon-Pen) was dissolved in toluene with 25% solids, 10% by weight of urethane-based resin (D-ACE-540T, homochemical) was dissolved in toluene with 50% solids, 25 wt% of phenoxy resin (E4275, Zepen epoxy resin) was dissolved in MEK at 40% solids, 30 wt% of epoxy (meth) acrylate (SP1509, Shohwa polymer), 2-methacryloyloxyethyl phosphate 2 Weight%, 8% by weight of pentaerythritol tri (meth) acrylate, 2% by weight of lauryl peroxide, 8% by weight of nickel powder having an average particle diameter of 4.5 µm, and 5% by weight of fused silica having an average particle diameter of 1 µm An anisotropic conductive film having a thickness of 35 μm was obtained by forming a conductive adhesive layer having a minimum melt viscosity of about 7,000 (Pa · s) and combining with the insulating adhesive layer. This anisotropic conductive film was slitted to a width of 2 mm to obtain a sample of Example 1.

Example  2

Example 2 except that an insulating adhesive layer having a minimum melt viscosity of about 2,000 (Pa · s) was formed by using 2% by weight of 2-hydroxyethyl (meth) acrylate and 1% by weight of 3-glycidoxypropyl triethoxy silane. An anisotropic conductive film was obtained by the same method as 1.

Comparative example  One

An anisotropic conductive film was obtained by the same method as Example 1 except that the thickness of the insulating adhesive layer was 10 μm and the thickness of the conductive adhesive layer was 25 μm.

Comparative example  2

10% by weight of acrylonitrile butadiene resin (Nipol 1072, Nippon-Pen) was dissolved in toluene with 25% solids, 10% by weight of urethane-based resin (D-ACE-540T, homochemical) was dissolved in toluene with 50% solids, 33 wt% of phenoxy resin (E4275, Zefen epoxy resin) was dissolved in MEK at 40% solids, 30 wt% of epoxy (meth) acrylate (SP1509, Shohwa polymer), 2-methacryloyloxyethyl phosphate 2 Using a weight percent, 8 weight percent of pentaerythritol tri (meth) acrylate, 2 weight percent of lauryl peroxide, and 5 weight percent of fused silica having an average particle diameter of 1 mu m, the minimum melt viscosity is about 9,000 (Pa The insulating adhesive layer which is s) was comprised.

Dissolve 40% by weight of urethane-based resin (D-ACE-540T, Dynamic Chemical) in toluene with 50% solids, 2% by weight of phenoxy resin (E4275, Zepene epoxy resin) in MEK with 40% solids, and epoxy (Meth) acrylate (SP1509, Shohwa polymer) 40 wt%, 2-methacryloyloxyethyl phosphate 2 wt%, pentaerythritol tri (meth) acrylate 3 wt%, 2-hydroxyethyl (meth) acrylate Example 1, except that 3% by weight, 2% by weight of benzoyl peroxide, and 8% by weight of nickel powder having an average particle diameter of 4.5 m, except that a conductive adhesive layer having a minimum melt viscosity of about 2,000 (Pa · s) was formed. An anisotropic conductive film was obtained by the same method as described above.

Comparative example  3

5 wt% of phenoxy resin (E4275, Zefen epoxy resin) was dissolved in MEK at 40% solids, and the same as in Example 1 except that 45 wt% of epoxy (meth) acrylate (SP1509, Shohwa polymer) was used. By the method, an insulating adhesive layer having a thickness of 25 µm and a minimum melt viscosity of about 1,500 (Pa · s) was obtained.

20% by weight of phenoxy resin (E4275, Zepene epoxy resin) was dissolved in MEK at 40% solids, 40% by weight of epoxy (meth) acrylate (SP1509, Shohwa polymer) was used, and silica was not applied. By the same method as in Example 1, a conductive adhesive layer having a minimum melt viscosity of about 4,000 (Pa · s) was obtained.

Table 2 shows the results of evaluating the properties of the anisotropic conductive films prepared according to Examples 1 and 2 and Comparative Examples 1 to 3, and the evaluation of related items is as follows.

[Minimum Melt Viscosity]

Using an ARES G2 rheometer (TA Instruments), the temperature was measured at a temperature of 10 ° C./min, strain 5%, and a frequency of 1 rad / s at 30 ° C. to 200 ° C., and a parallel plate and an aluminum disposable plate (diameter 8 mm) were measured. Used.

[Adhesion and Connection Resistance]

In order to evaluate the performance of the anisotropic conductive film, a PCB having a pitch of 200 mu m (terminal width 100 mu m, distance between terminals 100 mu m) and COF (terminal width 100 mu m, distance between terminals 100 mu m) were used. The anisotropic conductive film was press-bonded to the PCB circuit terminal at 70 ° C., 1 second, and 1 MPa, and then the release film was removed. Then, the circuit terminal of COF was replaced, and then pressed at 160 ° C., 5 seconds, and 3.0 MPa. The 90 ° adhesive force and the connection resistance were measured using the specimen thus prepared. In addition, the connection resistance was measured after 500 hours storage at a temperature of 85 ℃, 85% relative humidity.

Adhesive force was used TINIUS OLSEN UTM equipment (model name H5KT), and the connection resistance was measured by KEITHLEY MULTIMETER 2000.

Recognition

The anisotropic conductive film pressed with the PCB terminal was photographed with a microscope (OLYMPUS company model name BX51), and the brightness (black 0, white 255) of each was measured. At this time, it was determined that the brightness of the anisotropic conductive film is 20% or more lower than the brightness of the PCB terminal to be recognized.

[Area ratio after compression]

In addition, by making a sample of 2mm X 10mm and replacing the glass substrate on the top and bottom, and then crimped at 160 degrees (based on the anisotropic conductive film detection temperature), 5 seconds, 3MPa (based on the sample area), the area ratio after the compression, that is, insulation Layer area / conductive layer area (outermost particle basis) were measured.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Adhesive force (gf / cm) 903 1066 658 723 789 Connection resistance (Ω) Early 0.30 0.31 0.30 0.32 0.31 500hr 0.40 0.43 0.51 1.18 0.48 Recognition Good Good Good Good Defective Area ratio after crimping 1.6 1.6 1.2 1.1 1.3

As shown in Table 2, in Examples 1 and 2, where the lowest melt viscosity of the conductive layer was larger than that of the insulating layer, and the thickness of the insulating layer was thicker, the characteristics of adhesiveness, connection resistance, and recognizability were excellent. . However, in Comparative Example 2 in which the lowest melt viscosity of the insulating layer was larger than that of the conductive layer, the adhesive strength was low and the connection resistance was high. In particular, the connection resistance after 500 hours storage at 85 ° C and 85% RH was very high, indicating a very poor reliability. In Comparative Example 1 in which the thickness of the insulating layer was thinner than that of the conductive layer, the adhesive strength was very small and the connection resistance was also high.

In Comparative Example 3, in which the difference between the lowest melt viscosity of the insulating layer and the conductive layer was 2,500 Pa.s, the adhesive strength was low, and the connection resistance after 500 hours storage at 85 ° C. and 85% RH was high. Appeared. In addition, Comparative Example 3 has the same film thickness as in Example 1 and Example 2, but did not include silica, which is an insulating particle, it was found that the recognition is poor.

100: anisotropic conductive film 102: insulating layer
104: conductive layer 106: conductive particles
108: insulating particles

Claims (25)

Insulating layer;
It includes a conductive layer laminated on the insulating layer and containing conductive particles,
The minimum melt viscosity of the said conductive layer is 3,000 Pa * s or more larger than the minimum melt viscosity of the said insulating layer, The anisotropic conductive film characterized by the above-mentioned.
The anisotropic conductive film of claim 1, wherein the lowest melt viscosity of the conductive layer is 3,000 to 48,000 Pa s greater than the lowest melt viscosity of the insulating layer.
The anisotropic conductive film of claim 1, wherein the lowest melt viscosity of the conductive layer is 4,000 to 50,000 Pa · s.
The anisotropic conductive film of claim 1, wherein the lowest melt viscosity of the insulating layer is 2,000 to 10,000 Pa · s.
The anisotropic conductive film of claim 1, wherein the insulating layer is thicker than the conductive layer.
The thickness ratio of the said insulating layer with respect to the said conductive layer is more than 1 and less than 4, The anisotropic conductive film of Claim 1 characterized by the above-mentioned.
The anisotropic conductive film according to claim 1, wherein the conductive layer or the insulating layer contains insulating particles.
The anisotropic conductive film of claim 7, wherein the conductive layer or the insulating layer comprises 0.1 to 20% by weight of insulating particles based on the whole composition.
8. The anisotropic conductive film according to claim 7, wherein the insulating particle content (wt%) of the conductive layer with respect to the entire conductive layer composition is greater than the insulating particle content (wt%) of the insulating layer with respect to the entire insulating layer composition. .
The anisotropic conductive film of claim 7, wherein the conductive layer comprises 2 to 20 wt% of insulating particles based on the entire conductive layer composition.
The anisotropic conductive film of claim 7, wherein the insulating layer comprises 0.1 to 10% by weight of insulating particles based on the entirety of the insulating layer composition.
The anisotropic conductive film of claim 1, wherein the conductive layer comprises 1 to 30% by weight of conductive particles with respect to the entire conductive layer composition.
The anisotropic conductive film of claim 1, wherein the conductive layer or the insulating layer composition comprises a polymer resin, a radical polymerizable material, and a radical initiator.
The method of claim 13, wherein the polymer resin is an olefin resin, butadiene resin, acrylonitrile butadiene copolymer, carboxyl terminal acrylonitrile butadiene copolymer, polyimide resin, polyamide resin, polyester resin, polyvinyl Butyral Resin, Ethylene-Vinyl Acetate Copolymer, Styrene-Butylene-Styrene (SBS) Resin, Styrene-Ethylene-Butylene-Styrene (SEBS) Resin, Acrylonitrile Butadiene Rubber (NBR), Urethane Resin , (Meth) acrylic resin or phenoxy resin any one or more of an anisotropic conductive film characterized by comprising
The anisotropic conductive film of claim 1, wherein the conductive layer and the insulating layer include a polymer resin having a molecular weight of 50,000 to 1 million.
The method of claim 15, wherein the conductive layer is the polymer resin 20 to 20 to the total composition of the conductive layer Anisotropic conductive film comprising 60% by weight.
The anisotropic conductive film of claim 15, wherein the insulating layer comprises 30 to 70 wt% of the polymer resin with respect to the entire composition of the insulating layer.
The anisotropic conductive film of claim 13, wherein the radically polymerizable material comprises a (meth) acrylate monomer (oligomer) or a urethane acrylate monomer (oligomer).
The anisotropic conductive film of claim 13, wherein the radically polymerizable material is included in an amount of 20 to 60 wt% based on the entirety of the conductive layer or the insulating layer composition.
The anisotropic conductive film of claim 13, wherein the radical initiator comprises at least one of a photopolymerization initiator and a thermosetting initiator.
The anisotropic conductive film of claim 13, wherein the radical initiator is contained in an amount of 0.5 wt% to 10 wt% with respect to the entire conductive layer or insulating layer composition.
The anisotropic conductive film of claim 13, wherein the conductive layer or the insulating layer composition comprises a silane coupling agent.
The anisotropic conductive film of claim 22, wherein the silane coupling agent is included in an amount of 0.1 to 5 wt% based on the entirety of the conductive layer or the insulating layer composition.
Insulating layer;
It includes a conductive layer laminated on the insulating layer and containing conductive particles,
After replacing the glass substrate on the upper and lower sides and pressing at 160 degrees (based on anisotropic conductive film sensing temperature), 5 seconds, and 3 MPa (based on sample area), the ratio of the area after pressing the insulating layer to the conductive layer is 1.4 to 3.0. Anisotropic conductive film characterized by the above-mentioned.
The anisotropic conductive film according to claim 24, wherein a minimum melt viscosity of the conductive layer is larger than a minimum melt viscosity of the insulating layer.

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