KR101138799B1 - Composition For Anisotropic Conductive Film - Google Patents

Abstract

The composition for anisotropic conductive films of the present invention comprises a polycyclic aromatic ring-containing epoxy resin, an acrylic rubber-based resin, conductive particles and a curing agent, wherein the polycyclic aromatic ring-containing epoxy resin has a glass transition temperature (Tg) after curing. Is 165 ° C to 220 ° C, and the acrylic rubber resin has a glass transition temperature (Tg) of 0 ° C to 20 ° C, and the sum of the content of the polycyclic aromatic ring-containing epoxy resin and the acrylic rubber resin is the total composition (solid content). It is characterized by being 45 to 65% by weight of the weight. The composition for anisotropic conductive films complements brittle properties of the epoxy resin in a high temperature and high humidity state to not only have flexibility and impact resistance to prevent the anisotropic conductive film in a hardened state from breaking, but also lowers connection resistance and thermal stability. It complements the part and can express high reliability and high adhesion.

Anisotropic conductive film, polycyclic aromatic ring-containing epoxy resin, acrylic rubber resin

Description

Composition for anisotropic conductive film {Composition For Anisotropic Conductive Film}

This invention relates to the composition for anisotropic conductive films which can be used as a connection material of a liquid crystal display device and a display apparatus panel, and the anisotropic conductive film by this composition.

In general, the 3-layer adhesive type flexible copper clad laminate (FCCL) manufacturing method used for conventional FOG (Film On Glass) bonding is performed by etching copper foil and polyimide film with an epoxy adhesive. The pattern was formed by the process. In this case, the thickness of copper foil is about 18 micrometers, and the pitch can be about 60 micrometers. In the bonding with existing Anisotropic Conductive Film, FCCL method has wide space and relatively thick copper foil, so physical bonding of anisotropic conductive film composed of epoxy resin and phenoxy resin-based composition is difficult. Could be excellent. In addition, the epoxy-based adhesive is exposed to the FCCL space portion, and thus the chemical usability is good, and thus, excellent adhesion and connection reliability can be obtained.

Recently, however, in FOG (Film On Glass) bonding, a two-layer adhesive-less type FPCB (Flexible Printed Circuit Board) has been widely applied. This is because the two-layer non-adhesive FPCB can be applied to a fine pitch of about 50 μm, is easy to manufacture a product, and can use a light and thin sputtering method.

The cured products of conventional bisphenol-A type (BPA) type epoxy resins, bisphenol-F type (BPF) type epoxy resins, phenoxy resins, and small amounts of rubber resins are hard and strong, but they are resistant to impact. It has a poor absorption ability and is brittle. Regarding the reliability, there is a problem that bubbles are generated, and a problem of deterioration of adhesive force occurs, which is more prominent in a two-layer non-adhesive FPCB than a three-layer adhesive FPCB. In particular, in the case of a two-layer non-adhesive type FPCB, the thickness of the copper foil is relatively thin, thereby causing a problem of lowering the physical adhesive force, and the above-described problem occurs because the FPCB space part is made of a polyimide film without epoxy adhesive.

The present invention is to properly adjust the content of the polycyclic aromatic ring-containing epoxy resin and acrylic rubber-based resin, to compensate for the brittle properties of the epoxy resin in a high temperature and high humidity state so that the anisotropic conductive film in the cured state is not broken It is an object to provide a composition for an anisotropic conductive film having both flexibility and impact resistance.

Moreover, an object of this invention is to provide the composition for anisotropic conductive films which can lower connection resistance and can supplement a thermally stable part.

In addition, an object of the present invention is to provide an anisotropic conductive film having high reliability and high adhesion.

The composition for anisotropic conductive films of the present invention comprises a polycyclic aromatic ring-containing epoxy resin, an acrylic rubber-based resin, conductive particles and a curing agent, wherein the polycyclic aromatic ring-containing epoxy resin has a glass transition temperature (Tg) after curing. Is 165 ° C to 220 ° C, the acrylic rubber resin has a glass transition temperature (Tg) of 0 ° C to 20 ° C, and the sum of the contents of the polycyclic aromatic ring-containing epoxy resin and the acrylic rubber resin is a total composition (solid content). It is characterized by being 45 to 65% by weight of the weight.

In an embodiment, the polycyclic aromatic ring-containing epoxy resin is cured from an epoxy monomer having a structure of Formula 2 below.

[Formula 2]

(Ar) _n -E _m

In the above, (Ar) _n is a polycyclic aromatic hydrocarbon, n is 2 to 4 by the number of benzene rings, E is selected from an epoxy group, a glycidyl group or a glycidyloxy group, m is 1 to 3.

In an embodiment, the polycyclic aromatic ring-containing epoxy resin is 1,6-bis (2,3-epoxypropoxy) naphthalene, 1,5-bis (2,3-epoxypropoxy) naphthalene and 2,2'- Cured from an epoxy monomer selected from the group consisting of bis (2,3-epoxypropoxy) binaphthalene.

In an embodiment, the acrylic rubber resin is a copolymer of two or more C1-20 alkylacrylates and one or more comonomers selected from methyl methacrylate, acrylonitrile and styrene.

In another embodiment, the acrylic rubber resin may contain at least one functional group selected from the group consisting of hydroxyl group, carboxyl group and epoxy group.

In specific examples, the content ratio of the polycyclic aromatic ring-containing epoxy resin and acrylic rubber resin is 1: 1 to 3.

In embodiments, the composition may include 15 to 30% by weight of the polycyclic aromatic ring-containing epoxy resin, 30 to 45% by weight of the acrylic rubber resin, 0.1 to 15% by weight of the conductive particles and 10 to 45% by weight of the curing agent.

In another embodiment the composition is a bisphenol epoxy, phenol novolac epoxy, σ-cresol novolac epoxy, polyfunctional epoxy, amine epoxy, heterocyclic containing epoxy, substituted epoxy, It may further comprise one or more epoxy resins selected from naphthol-based epoxy and derivatives thereof.

The curing agent may be at least one selected from imidazole-based, isocyanate-based, amine-based, amide-based and acid anhydride-based curing agents.

The conductive particles are metal particles containing at least one of Au, Ag, Ni, Cu, Sn, Ti, and Pb; Carbon particles; Particles coated with the metal particles of particles comprising a resin containing at least one of benzoguanamine, polyethylene, polyester, polystyrene, and polyvinyl alcohol or modified resins thereof; And at least one of the insulated particles coated with the insulated particles.

In embodiments, the composition may further comprise a silane coupling agent.

In addition, the composition may further include an additive selected from the group consisting of organic particles, inorganic particles, polymerization inhibitors, antioxidants, heat stabilizers and light stabilizers.

The present invention provides an anisotropic conductive film formed by the composition.

The anisotropic conductive film formed by the composition of the present invention can have the flexibility and impact resistance to complement the brittle property of the epoxy resin in the high temperature and high humidity state so that the anisotropic conductive film in the cured state is not broken.

In addition, the connection resistance can be lowered and the thermal stability part can be complemented, and high reliability and high adhesion can be expressed.

Polycyclic  Aromatic ring-containing epoxy resin

The polycyclic aromatic ring-containing epoxy resin of the present invention is an epoxy resin in which two or more benzene rings are continuously bonded to each other and has a structure in which an epoxy group is substituted with a polycyclic benzenoid aromatic compound.

In one embodiment, the polycyclic aromatic ring-containing epoxy resin is cured from an epoxy monomer having a structure of Formula 2 below.

[Formula 2]

(Ar) _n -E _m

In the above, (Ar) _n is a polycyclic aromatic hydrocarbon, n is 2 to 4 by the number of benzene rings, E is selected from an epoxy group, a glycidyl group or a glycidyloxy group, m is 1 to 3.

As (Ar) _n , naphthalene, anthracene, etc. are mentioned, A preferable example is naphthalene. E is an epoxy group, glycidyl group glycidyloxy group, etc., Preferably it is glycidyloxy group.

In an embodiment, as the epoxy monomer for preparing the polycyclic aromatic ring-containing epoxy resin, 1,6-bis (2,3-epoxypropoxy) naphthalene, 1,5-bis (2,3-epoxypropoxy) Naphthalene, 2,2'-bis (2,3-epoxypropoxy) binaphthalene, and the like, and are not necessarily limited thereto as long as the glass transition temperature after curing is in the range of 165 ° C to 220 ° C. Of these, 1,6-bis (2,3-epoxypropoxy) naphthalene is preferable.

In the present invention, the glass transition temperature after curing of the polycyclic aromatic ring-containing epoxy resin has a range of 165 ° C to 220 ° C, preferably 180 ° C to 220 ° C. By including a polycyclic aromatic ring-containing epoxy resin having a relatively high glass transition temperature as described above to compensate for the weak thermal stability portion has a super heat resistance.

In a specific embodiment, the viscosity of the polycyclic aromatic ring-containing epoxy resin (25 ° C.) may be 10,000 to 50,000 cps, preferably 12,000 to 35,000 cps, and more preferably 15,000 to 30,000 cps.

When excessively applying the acrylic rubber-based resin may cause a problem that the spring back phenomenon occurs when the thermal compression due to excessive elasticity, the gap between the electrodes is increased to increase the connection resistance. To compensate for this, the polycyclic aromatic ring-containing epoxy resin, which is a low-viscosity resin, is blended to increase the overflow during thermal compression, and the connection resistance of the anisotropic conductive film resin can be increased to lower the connection resistance. .

acryl Rubber system  Suzy

The acrylic rubber-based resin of the present invention has a repeating structure in which an acrylic ester is polymerized as shown in Chemical Formula 1, and the alkyl group of the side chain may be in a copolymer form of two or more kinds. In addition, methyl methacrylate (methyl metacrylate), acrylonitrile (styrene), styrene (styrene) and the like may be included as a repeating unit.

[Formula 1]

R is an alkyl group having 1 to 20 carbon atoms.

In Chemical Formula 1, the longer the length of the side chain R, the lower the glass transition temperature (Tg) of the acrylic rubber, the higher the thermal fluidity, the lower the connection reliability and the low temperature resistance tends to be improved. Therefore, the length and structure of the side chain can be adjusted to obtain desired characteristics of the circuit connection composition.

Specific examples of the acryl rubber-based resin, acrylonitrile two or more of C _{1 ~ 20} alkyl acrylate and methacrylate, acrylonitrile, a copolymer of a comonomer selected from at least one styrene. When one or more comonomers selected from methyl methacrylate, acrylonitrile and styrene monomers are introduced, additional properties can be obtained while maintaining the basic adhesion and raw material miscibility of the acrylic rubber resin.

The ratio between the two or more C _{1 ~ 20} alkyl acrylate and the comonomer may be adjusted as necessary so that the glass transition temperature range of the final polymerized acrylic rubber-based resin is 0 ℃ ~ 20 ℃.

In an embodiment, the acrylic rubber resin may have at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group and an epoxy group. Preferably it is an epoxy group containing acrylic copolymer.

The acrylic rubber resin of the present invention has a weight average molecular weight in the range of 100,000 to 1 million. Within the above range, the film may have excellent strength and adhesion. In addition, since it is excellent in miscibility with other resins, it is possible to have excellent connection reliability because a uniform crude liquid is possible.

In the present invention, the glass transition temperature of the acrylic rubber resin has a range of 0 ℃ ~ 20 ℃. The anisotropic conductive film by applying a predetermined amount of a bisphenol-A (BPA) type epoxy resin or a bisphenol-F type (BPF) type epoxy resin as a binder to the acrylic rubber resin having a low glass transition temperature (Tg) as described above Make the properties very flexible. In addition, it is possible to combine the flexibility and impact resistance that the hardened anisotropic conductive film is not broken by supplementing the brittle property, which is an inherent property of the epoxy resin at high temperature and high humidity.

In the composition for anisotropic conductive films according to the present invention, the acrylic rubber-based resin is preferably a matrix, and the polycyclic aromatic ring-containing epoxy resin is preferably distributed in the entire domain. In the specific example, the acrylic rubber resin is 30 to 45% by weight, preferably 30 to 40% by weight of the total composition (solid content). In addition, the polycyclic aromatic ring-containing epoxy resin is 15 to 30% by weight, preferably 15 to 20% by weight of the total composition (solid content).

In the present invention, the sum of the content of the polycyclic aromatic ring-containing epoxy resin and the acrylic rubber resin is 45 to 65% by weight of the total composition (solid content), and preferably 45 to 60% by weight.

In addition, the content ratio of the polycyclic aromatic ring-containing epoxy resin and the acrylic rubber resin is 1: 1 to 3, preferably 1: 2 to 3.

By the appropriate content ratio of the polycyclic aromatic ring-containing epoxy resin and the acrylic rubber-based resin as described above, a composition for anisotropic conductive films having characteristics of high reliability and high adhesion can be made.

Conductive particles

The anisotropic conductive film composition of this invention contains electroconductive particle in order to improve the electroconductive performance at the time of a circuit connection.

Such conductive particles include metal particles containing at least one of Au, Ag, Ni, Cu, Sn, Ti, and Pb; Carbon particles; Particles coated with the metal particles of particles comprising a resin containing at least one of benzoguanamine, polyethylene, polyester, polystyrene, and polyvinyl alcohol or modified resins thereof; Insulated particles coated with the coated particles with insulating particles; It is preferable that it is one or more selected from.

The size of the said electroconductive particle can be selected and used according to a use in 0.1-30 micrometers range by the pitch of the circuit applied. Preferably it is 0.5-15 micrometers.

In the present invention, the conductive particles are used in the range of 0.1 to 15% by weight based on the total composition (solid content). If the content of the conductive particles is less than 0.1% by weight, there is no improvement in conductive performance. If the content of the conductive particles is more than 15% by weight, insulation failure may occur. Preferably 0.5 to 10% by weight, more preferably may be used in 1 to 5% by weight.

Hardener

The composition for anisotropic conductive films which concerns on this invention may further contain a hardening | curing agent. As the curing agent, any epoxy curing type thermosetting agent known in the art may be used without limitation.

In embodiments, at least one selected from imidazole-based, isocyanate-based, amine-based, amide-based and acid anhydride-based may be used as the curing agent, but is not limited thereto. The curing agent may be used in 10 to 45% by weight, preferably 15 to 40% by weight, more preferably 20 to 35% by weight.

The composition for anisotropic conductive films according to the present invention may further include an epoxy resin. The epoxy resin is a bisphenol epoxy, phenol novolac epoxy, σ-cresol novolac epoxy, polyfunctional epoxy, amine epoxy, heterocyclic containing epoxy, substituted epoxy, naphthol epoxy And at least one selected from derivatives thereof. The epoxy resin may be used in 30% by weight or less of the total composition, preferably 25% by weight or less, more preferably 20% by weight or less. In embodiments, the epoxy resin may be used in 0 to 15% by weight. In another embodiment, the epoxy resin may be used in an amount of 1 to 10% by weight.

The anisotropic conductive film composition of the present invention adds other additives such as organic particles, inorganic particles, silane coupling agents, polymerization inhibitors, antioxidants, heat stabilizers and light stabilizers in order to further improve the physical properties without impairing the basic physical properties. It may contain about 0.01 to 10% by weight.

The silane coupling agent contains 2- (3,4 epoxy cyclohexyl) -ethyltrimethoxysilane, 3-glycidoxytrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and an amine group containing epoxy. N-2 (aminoethyl) 3-amitopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysil-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimeth It is preferably at least one selected from oxysilane, 3-mercaptopropylmethyldimethoxysilane containing mercapto, 3-mercaptopropyltriethoxysilane and 3-isocyanatepropyltriethoxysilane containing isocyanate. Preferably the silane coupling agent may comprise 0.1 to 7% by weight, more preferably 1 to 5% by weight.

As the polymerization inhibitor, those selected from the group consisting of hydroquinone monomethyl ether, p-benzoquinone, phenothiazine and mixtures thereof can be used. In addition, antioxidants such as phenolic or hydroxy cinnamate-based substances, which have been prepared for the purpose of preventing oxidation reaction and imparting thermal stability of the composition induced by heat, may be added. For example, tetrakis- (methylene- (3,5-di-t-butyl-4-hydro cinnamate) methane, 3,5-bis (1,1-dimethylethyl) -4-hydroxy benzene propanoic acid thiol di-2,1-ethane Diyl ester, octadecyl 3,5-di-t-butyl-4-hydroxy hydrocinnamate (manufactured by Ciba), 2,6-di-tertiary-p-methylphenol, and the like. Each can be used individually or in mixture of 2 or more types.

The anisotropic conductive film of this invention can be manufactured easily using the composition for anisotropic conductive films of this invention, without a special apparatus or installation. For example, after dissolving the composition of the present invention in an organic solvent such as toluene and liquefying, the conductive particles are stirred for a predetermined time within a speed range in which the conductive particles are not crushed, and then applied to a release film at a thickness of 10 to 50 μm, and then The anisotropic conductive film can be obtained by drying for time and volatilizing solvents, such as toluene.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example  1-4 and Comparative example  1-4

The composition obtained by mixing each component as shown in Table 1 was applied onto a release film, and dried at a temperature of 80 ° C. for 5 minutes using an oven to obtain an anisotropic conductive film having a thickness of 35 μm and a width of 1.5 mm.

Furtherance Comparative example Example One 2 3 4 One 2 3 4 (A) polycyclic aromatic
Epoxy resin 5 10 25 40 15 20 20 30 (B) acrylic rubber resin 10 20 50 20 30 40 45 30 (C) hardener 30 30 20 30 30 30 30 30 (D) conductive particles 3 3 3 3 3 3 3 3 (E) epoxy resin 50 35 - 5 20 5 - 5 (F) silane coupling agent 2 2 2 2 2 2 2 2 ToTal (% by weight) 100 100 100 100 100 100 100 100 In full composition
[Polycyclic aromatic content + acrylic rubber resin] content 15 30 75 60 45 60 65 60 In full composition
[Polycyclic aromatic content: acrylic rubber resin] ratio 1: 2 1: 2 1: 2 2: 1 1: 2 1: 2 1: 2.25 1: 1

(A) Polycyclic aromatic containing epoxy resin: Naphthalene type epoxy resin (product name: HP4032D) manufactured by Japan Ink Chemical Co., Ltd. was used.

(B) Acrylic rubber resin: An acrylate copolymer (product name: SG-P3-TEA) manufactured by Nagase Chemtex was used.

(C) Curing agent: A microcapsule-type imidazole (product name: HX3941HP) manufactured by Asahi Kasei was used.

(D) Conductive particles: AUL 704 manufactured by Sekisui Corporation was used.

(E) Epoxy Resin: A BPA epoxy resin (product name: EXA 850CRP) manufactured by Nippon Ink Chemical Co., Ltd. was used.

(F) Silane coupling agent: Epoxy silane (Product name: KBM403) manufactured by Shin-Yetsu was used.

Property and Reliability Evaluation

In order to measure the connection reliability between the ITO glass panel and the FPCB, bubbles using FPCB of four types (Adhesive type 1, Adhesive type 2, Adhesive-less type 1, Adhesive-less type 2) as shown in Table 2 below Occurrence was measured.

In addition, the evaluation results of the characteristics of each of the comparative examples and the respective examples are summarized in Table 3 below.

(* Measured using Adhesive-less FPCB1)

As shown in the results of Table 2 and Table 3, when applied to the adhesive-less type FPCB using an anisotropic conductive film having the same content ratios as Examples 1 to 4, almost no bubbles were generated, showing high reliability. You can check it. In addition, the examples can confirm that the low resistance value and high adhesion when compared with the comparative examples, it can be seen that the reliability, adhesion and the like all improved compared to the comparative example.

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

Claims (13)

It comprises a polycyclic aromatic ring-containing epoxy resin, acrylic rubber-based resin, conductive particles and a curing agent, the polycyclic aromatic ring-containing epoxy resin is a glass transition temperature (Tg) of 165 ℃ ~ 220 ℃ after curing, Acrylic rubber resin has a glass transition temperature (Tg) of 0 ℃ ~ 20 ℃, The sum of the content of the polycyclic aromatic ring-containing epoxy resin and the acrylic rubber resin is 45 to 65% by weight of the total composition (solid content), the composition for anisotropic conductive films. The composition for an anisotropic conductive film according to claim 1, wherein the polycyclic aromatic ring-containing epoxy resin is cured from an epoxy monomer having a structure of Formula 2 below: [Formula 2] (Ar) _n -E _m In the above, (Ar) _n is a polycyclic aromatic hydrocarbon, n is 2 to 4 by the number of benzene rings, E is selected from an epoxy group, glycidyl group or glycidyloxy group, m is 1 to 3. The method of claim 2, wherein the polycyclic aromatic ring-containing epoxy resin is 1,6-bis (2,3-epoxypropoxy) naphthalene, 1,5-bis (2,3-epoxypropoxy) naphthalene and 2, A composition for an anisotropic conductive film, which is cured from an epoxy monomer selected from the group consisting of 2'-bis (2,3-epoxypropoxy) binaphthalene. Claim for according to item 1, wherein the acrylic rubber-based resin, two or more of C _{1 ~ 20} alkyl acrylate and methacrylate, acrylonitrile, the anisotropic conductive film, characterized in that a copolymer of a comonomer selected one or more from styrene Composition. The composition for anisotropic conductive films according to claim 1, wherein the acrylic rubber resin contains at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group and an epoxy group. The composition for an anisotropic conductive film according to claim 1, wherein the content ratio of the polycyclic aromatic ring-containing epoxy resin and acrylic rubber-based resin is 1: 1 to 3. The composition of claim 1, wherein the composition comprises 15 to 30% by weight of a polycyclic aromatic ring-containing epoxy resin, 30 to 45% by weight of an acrylic rubber resin, 0.1 to 15% by weight of conductive particles, and 10 to 45% by weight of a curing agent. The composition for anisotropic conductive films. The composition of claim 1, wherein the composition is bisphenol-based epoxy, phenol novolac-based epoxy, σ-cresol novolac-based epoxy, polyfunctional epoxy, amine-based epoxy, heterocyclic-containing epoxy, substituted type Composition for anisotropic conductive film further comprises at least one epoxy resin selected from epoxy, naphthol-based epoxy and derivatives thereof. The composition for anisotropic conductive films according to claim 1, wherein at least one of the curing agents is selected from imidazole-based, isocyanate-based, amine-based, amide-based and acid-anhydride-based curing agents. The method of claim 1, wherein the conductive particles Metal particles comprising at least one of Au, Ag, Ni, Cu, Sn, Ti, and Pb; Carbon particles; Particles coated with the metal particles of particles comprising a resin containing at least one of benzoguanamine, polyethylene, polyester, polystyrene, and polyvinyl alcohol or modified resins thereof; And Insulated particles coated with the coated particles with insulating particles; At least one selected from the composition for anisotropic conductive film. The composition for anisotropic conductive films according to claim 1, wherein the composition further comprises a silane coupling agent. The composition of claim 1, wherein the composition further comprises an additive selected from the group consisting of organic particles, inorganic particles, polymerization inhibitors, antioxidants, heat stabilizers, and light stabilizers. The anisotropic conductive film formed by the composition of any one of Claims 1-12.