KR101131162B1 - Fast curable anisotropic conductive film composition, fast curable anisotropic conductive film using the composition - Google Patents

Abstract

The present invention relates to a composition for a low temperature hardening type anisotropic conductive film, and more particularly, to a propylene oxide-based epoxy having two or more epoxy groups in one molecule and containing propylene oxide in a main chain of a molecular chain. Low temperature fast curing type including resin, curing agent, binder resin, conductive particles, and solvent, which enables low temperature fast curing, excellent electrical properties, and excellent adhesion and low electrical connection resistance even in high temperature and humidity environments and thermal shock conditions. It relates to a composition for an anisotropic conductive film.

Anisotropic Conductive Film, Propylene Oxide, Cation Curing, Low Temperature Fast Curing

Description

FAST CURABLE ANISOTROPIC CONDUCTIVE FILM COMPOSITION, FAST CURABLE ANISOTROPIC CONDUCTIVE FILM USING THE COMPOSITION}

The present invention relates to a composition for a low temperature hardening type anisotropic conductive film, and more particularly, to a propylene oxide-based epoxy having two or more epoxy groups in one molecule and containing propylene oxide in a main chain of a molecular chain. It relates to a composition for a low temperature fast curing type anisotropic conductive film containing a resin, a curing agent, a binder resin, conductive particles and a solvent.

Electromagnetic waves generated from components of various electronic products are not only harmful to the human body, but also cause malfunction of peripheral devices, which may cause device failure. In order to block such unnecessary electromagnetic waves, a conductive film is used at the time of assembly of an electronic component.

The anisotropic conductive film consists essentially of electroconductive particle and insulating resin. Carbon conductive particles were initially used as the conductive particles of the composition for the conductive film, and then solder balls were used, and now conductive balls coated with nickel or gold on nickel balls, silver balls or plastic spherical particles were used. Use or coat the insulating film on it.

The insulating resin which determines the physical properties of the conductive film in the composition for the conductive film is classified into a curable resin and a plastic resin depending on whether or not the molecular structure changes with heat. The double curable resin is classified into a thermosetting resin and a photocurable resin according to a curing method, and the photocurable resin is classified into an ultraviolet curable resin and an infrared curable resin according to the type of light. Among them, the resin most used in the composition for a conductive film has an advantage of easy management of a cured structure as a thermosetting resin, but has a disadvantage of requiring a long time with thermal energy. As thermosetting resins, epoxy resins and acrylic resins are mainly used. Epoxy type thermosetting resins have advantages of high adhesion to various types of substrates and excellent heat and moisture resistance, but have disadvantages such as high adhesion temperature and long adhesion time. On the other hand, acrylic thermosetting resins have advantages of low adhesion temperature and short adhesion time, but have disadvantages of low adhesion strength, low heat resistance, and moisture resistance reliability.

In the conventional anisotropic conductive film production, it is known that the epoxy curing system requires a relatively high temperature bonding compared to the acrylic curing system. However, in recent years, bonding using a cationic latent catalytic type curing system at a temperature lower than that of the acrylic curing system is performed. It is known that this is possible. However, the electrical connection resistance is increased by the low temperature bonding of the epoxy system, and thus there is a problem in that On / Off defects may appear when the module is mounted.

In order to solve the problems of the prior art as described above, the present invention is a low temperature fast curing type capable of low temperature fast curing, very excellent electrical properties, excellent adhesion and low electrical connection resistance even in high temperature and high humidity conditions or thermal shock conditions It is an object to provide a composition for an anisotropic conductive film.

In another aspect, the present invention provides a composition for anisotropic conductive film that can improve the indentation state and connection resistance in the mounted state after curing of the anisotropic conductive film, and a low temperature fast curing type anisotropic conductive film using the same and a low temperature fast curing type anisotropic conductive film using the same It aims to do it.

In order to achieve the above object, the present invention

a) a propylene oxide-based epoxy resin having two or more epoxy groups in one molecule and having propylene oxide in the main chain of the molecular chain;

b) curing agent;

c) binder resins;

d) conductive particles; And

e) solvents;

It provides a composition for a low-temperature fast-curing anisotropic conductive film comprising a.

Specifically, the present invention provides

a) with respect to 100 parts by weight of a propylene oxide epoxy resin having at least two epoxy groups in one molecule and containing propylene oxide in the main chain of the molecular chain;

b) 0.05 to 30 parts by weight of the curing agent;

c) 20 to 300 parts by weight of the binder resin;

d) 1 to 40 parts by weight of conductive particles; And

e) 10 to 200 parts by weight of the solvent;

Included as.

In particular, the propylene oxide epoxy resin is preferably a bisphenol A-propylene oxide (BPA-PO) epoxy resin.

In addition, the curing agent is preferably a cationic latent curing agent, and particularly preferably an antimony-based cationic latent curing agent.

In another aspect, the present invention provides a low-temperature fast curing type anisotropic conductive film formed of the composition as described above.

The composition for the low temperature fast curing type anisotropic conductive film according to the present invention is capable of low temperature fast curing, excellent electrical properties, and can maintain excellent adhesion and low electrical connection resistance even in high temperature and high humidity environments or thermal shock conditions. In addition, it is possible to improve the indentation state and the connection resistance in the mounted state after curing of the anisotropic conductive film of the present invention.

Hereinafter, the present invention will be described in detail.

The composition for a low temperature hardening type anisotropic conductive film described in the present invention uses a propylene oxide-based epoxy resin having two or more epoxy groups in one molecule and containing propylene oxide in the main chain of the molecular chain. The cation curing system of an epoxy resin which added a hardening | curing agent, especially a cationic latent hardening | curing agent to a propylene oxide type epoxy resin.

The present invention comprises a propylene oxide-based epoxy resin and a cationic latent curing agent having two or more epoxy groups in one molecule in a composition for a low temperature hardening type anisotropic conductive film and containing propylene oxide in the main chain of a molecular chain. It is characteristic to shorten hardening temperature and to improve an electrical characteristic by using.

The composition for a low temperature hardening type anisotropic conductive film of the present invention has a propylene oxide-based epoxy resin, a curing agent, a binder resin, a conductive material having two or more epoxy groups in one molecule and containing propylene oxide in the main chain of the molecular chain. Particles and solvents.

The propylene oxide (PO) -based epoxy resin used in the present invention may have any two or more epoxy groups in one molecule, and may be used without limitation as long as propylene oxide is included in the molecular chain. Specifically, the propylene oxide epoxy resin is a bisphenol epoxy compound such as bisphenol A epoxy resin, bisphenol F epoxy resin; Aromatic epoxy compounds such as a polyglycidyl ether epoxy resin and a polyglycidyl ester epoxy resin; Alicyclic epoxy compounds; Novolak-type epoxy compounds, such as a cresol novolak-type epoxy resin and a phenol novolak-type epoxy resin; Glycidyl amine epoxy compounds; Glycidyl ester epoxy compounds; A biphenyl diglycidyl ether epoxy compound, a tri glycidyl isocyanurate epoxy compound, a poly glycidyl methacrylate epoxy compound, a glycidyl methacrylate epoxy compound, etc. can be used.

In particular, the propylene oxide epoxy resin is preferably a bisphenol A-propylene oxide (BPA-PO) type epoxy resin that can increase the flexibility of the cured product, improve the reactivity and electrical properties.

The bisphenol A-propylene oxide (BPA-PO) type epoxy resin is not limited as long as it is an epoxy resin in which two or more propylene oxide is added to a bifunctional or polyfunctional bisphenol A type epoxy resin containing two or more glycidyl groups per molecule. For example, EP-4000S, EP-4000SS, EP-4003S, EP-4010S, EP-4011S (above Asahi Denka Co., Ltd.), etc. can be used.

The propylene oxide epoxy resin is preferably included in 10 to 90% by weight based on the total content of the composition. If the content is less than 10% by weight relative to the total content of the composition, the physical properties of the cured final adhesive may be low. If the content exceeds 90% by weight, the curing shrinkage may be large and the adhesive strength may be lowered.

The curing agent used in the present invention serves to cure the adhesive formed by the composition of the present invention by reacting with the glycidyl group of the propylene oxide epoxy resin.

Since the curing agent is mixed with the propylene oxide epoxy resin at room temperature, it should not have reactivity with the propylene oxide epoxy resin at room temperature after mixing, and has an activity at a predetermined temperature or more to actively react with the propylene oxide epoxy resin. Physical properties should be expressed.

The curing agent can be used as long as it is a compound capable of generating a cation by thermal activation energy, without limitation, in particular, it is preferable to use a cationic latent curing agent. Specifically, the cationic latent curing agent includes onium salt compounds such as aromatic diazonium salts, aromatic sulfonium salts, aliphatic sulfonium salts, aromatic iodine aluminum salts, phosphonium salts, pyridinium salts, and serenium salts; Complex compounds such as metal arene complexes and silanol / aluminum complexes; Compounds which have an electron capture function by including tosyreto groups such as benzoin tosylato- and o-nitrobenzyl tosylato- may be used. In particular, it is preferable to use sulfonium salt compounds, such as aromatic sulfonium salt compound or aliphatic sulfonium salt compound with high cation generation efficiency.

In addition, when such a cationic latent curing agent forms a salt structure, it is reactive to use hexafluoroantimonate, hexafluorophosphate, tetrafluoroborate, pentafluorophenyl borate, and the like as counter ions when forming the salt. More preferred in terms of aspect.

The cationic latent curing agent is preferably included in an amount of 0.05 to 30 parts by weight based on 100 parts by weight of the propylene oxide epoxy resin. If the content is less than 0.05 parts by weight, hardening does not occur sufficiently, and if it exceeds 30 parts by weight, compatibility may be reduced.

The binder resin used in the present invention is used for thickening or film formation in the composition for anisotropic conductive films.

The binder resin may be used by appropriately adding a conventional polymer used in the art, and can be used without particular limitation so long as it does not inhibit the curing of the propylene oxide-based epoxy resin. Specifically, the binder resin is a polyimide resin, polyamide resin, phenoxy resin, poly methacrylate resin, poly acrylate resin, polyurethane resin, polyester resin, polyester urethane resin, polyvinyl butyral resin, sty Styrene-butyrene-styrene (SBS) resins and epoxy modified bodies, styrene-ethylene-butylene-styrene (SEBS) resins and modified substances thereof, acrylonitrile butadiene rubber (NBR) and its hydrogenated bodies Can be. The polymer may also contain a siloxane bond or a fluorine substituent.

The larger the weight average molecular weight of the binder resin, the easier it is to form a film, but is not particularly limited.

Specifically, the weight average molecular weight of the binder resin is preferably 5,000 to 150,000, more preferably 10,000 to 80,000. When the weight average molecular weight of the binder resin is less than 5,000, the film formation may be lowered, and when the weight average molecular weight of the binder resin exceeds 150,000, compatibility with other components may be worsened.

The binder resin is preferably included in 20 to 300 parts by weight based on 100 parts by weight of the propylene oxide epoxy resin. If the content is less than 20 parts by weight It is not possible to form an anisotropic conductive film, and when it exceeds 300 parts by weight, the epoxy and the curing agent ratios participating in other curing parts are too low to easily exhibit thermosetting properties.

The electroconductive particle used for this invention can use the metal particle, or the thing coated with metal, such as gold or silver, on the organic and inorganic particle. Moreover, in order to ensure the electrical insulation at the time of excessive use, electroconductive particle may be insulated and used.

Specifically, the conductive particles are metal particles containing Au, Ag, Ni, Cu, solder, etc .; carbon; Particles coated with a metal containing Au, Ag, Ni, etc., using resins containing polyethylene, polypropylene, polyester, polystyrene, polyvinyl alcohol, and the like, and modified resins thereof as particles; Insulated electroconductive particle etc. which further coated the insulating particle on it can be used.

The size of the conductive particles can be selected and used depending on the application in the range of 2 to 30 ㎛ by the pitch of the circuit to be applied.

The conductive particles are preferably contained in an amount of 1 to 40 parts by weight based on 100 parts by weight of the propylene oxide epoxy resin. If the content is less than 1 part by weight, the adhesive formed from the composition for anisotropic conductive film of the present invention may not exhibit sufficient electrical conductivity. If the content is more than 40 parts by weight, the insulation reliability between the connection circuits may not be secured, and thus the anisotropic conductivity may not be exhibited. Can be.

The solvent used in the present invention uniformly mixes the propylene oxide epoxy resin, the cationic latent curing agent, the binder resin, and the conductive particles, and serves to lower the viscosity of the composition to facilitate the manufacture of the film.

The solvent may be used without limitation as long as it is conventional, and specifically, toluene, xylene, propylene glycol monomethyl ether acetate, benzene, acetone, methyl ethyl ketone, tetrahydrofuran, dimethylformaldehyde, cyclohexanone, etc. may be used. .

The solvent is preferably included in 10 to 200 parts by weight based on 100 parts by weight of the propylene oxide epoxy resin. If the content is less than 10 parts by weight, it may not be easy to disperse between the raw materials, and if it exceeds 200 parts by weight, a residual solvent may be present during drying to inhibit physical properties of the anisotropic conductive film.

The composition for a low temperature fast-curing anisotropic conductive film of the present invention as described above further comprises additives such as polymerization inhibitors, antioxidants, heat stabilizers, curing accelerators, coupling agents, etc. to add additional physical properties without inhibiting basic physical properties. can do. The content is preferably included in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the propylene oxide epoxy resin.

As the polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, phenothiazine, and mixtures thereof may be used. In addition, as the antioxidant used for the purpose of preventing oxidation reaction and imparting thermal stability of the composition induced by heat, a branched phenolic or hydroxy cinnamate-based substance 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-ethanediyl ester, octadecyl 3,5-di-t-butyl-4-hydroxy hydrocinnamate (above manufactured by Ciba), 2,6-di-tertiary-p-methylphenol, and the like. As the curing accelerator for improving the reaction rate, at least one of a solid imidazole accelerator, a solid phase and a liquid amine curing accelerator can be used, etc. As the coupling agent, vinyl trichloro silane, vinyl trimethoxy silane, 3- Glycidoxy propyl trimethoxy silane, 3-methacryloxy propyl trimeth Silane, 2-aminoethyl-3-aminopropyl methyldimethoxy silane, 3-ureidopropyl triethoxy silane, and the like, and one or more of these various silane coupling agents may be used. It is not limited to kinds.

In addition, the composition for the low-temperature fast-curable anisotropic conductive film of the present invention has a size of about 5 to 20 nanometers (nm) surface-treated with an organic silane, in addition to the basic constituent factors and the essential containing factors for achieving the object of the present invention. By including hydrophobic nano-silica particles having a smooth flow control according to the process conditions and the hardened structure of the cured anisotropic conductive film to be very robust to prevent expansion at high temperatures, thereby providing excellent initial adhesion and low connection resistance It is also possible to manufacture an anisotropic conductive film to implement.

Hydrophobic nano silica particles having a size of about 5-20 nanometers (nm) surface-treated with such organic silanes include Aerosil R-972, Aerosil R-202, Aerosil R-805, Aerosil R-812, Aerosil R-8200 (Degussa) and the like, and may be used in any kind, but is not necessarily limited thereto.

The composition for a low temperature fast-curing anisotropic conductive film of the present invention comprising the above components can improve the electrical connection characteristics of the packaging products generated during the circuit connection of various display devices and semiconductor devices, including liquid crystal display (LCD), in particular anisotropic There is an excellent effect in improving the indentation state and the connection resistance in the mounted state after curing of the conductive film.

In another aspect, the present invention provides a low-temperature fast curing type anisotropic conductive film formed of the composition for an anisotropic conductive film as described above.

The method for forming the anisotropic conductive film does not require a special device or equipment, the propylene oxide-based epoxy resin, cationic latent curing agent, binder resin and conductive particles dissolved in a solvent to liquefy by liquefying the above range of components After stirring for a predetermined time to obtain a uniform mixture, it is applied to a thickness of 10 ~ 50 ㎛ on a release film and then dried for a certain time to obtain a single layer anisotropic conductive film. In the present invention, the above-described process may be repeated two or more times to obtain a low temperature fast curing type anisotropic conductive film having a two or more multilayer structure.

Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples and Examples. These embodiments are for purposes of illustration only and are not intended to limit the scope of protection of the present invention.

Example 1

45 parts by weight of propylene oxide epoxy resin (EP-4000S, Adeka, Japan), 2 parts by weight of cationic latent curing agent (Si-60L, Samshin Chemical, Japan), 28 parts by weight of phenoxy resin (PKHH, Inchemrez, USA) 15 parts by weight of conductive particles (AUL-704, average particle size: 4 μm, SEKISUI, Japan) and 50 parts by weight of xylene and 50 parts by weight of ethyl acetate were mixed to prepare a composition for a low temperature hardening type anisotropic conductive film. .

Example 2

Except for using EP-4010S (Adeka, Japan) as the propylene oxide epoxy resin in Example 1 was carried out in the same manner as in Example 1.

Comparative Example 1

Except for using a general bisphenol A (BPA) epoxy resin JER-828 (JER, Japan) instead of the propylene oxide epoxy resin in Example 1 was carried out in the same manner as in Example 1.

After applying the compositions for the anisotropic conductive films prepared in Examples 1 and 2 and Comparative Example 1, respectively, on a white release film, the solvent was volatilized in a dryer at 80 ° C. to obtain a dried anisotropic conductive film having a thickness of 20 μm.

The physical properties of the anisotropic conductive film formed using the compositions for anisotropic conductive films prepared in Examples 1, 2 and Comparative Example 1 were evaluated, and the results are shown in Tables 1 and 2 below.

First, using the glass substrate having an indium tin oxide (ITO) circuit having a bump area of 2000 μm ² and a thickness of 5000 μm and a chip having a bump area of 2000 μm ^{2 having a} thickness of 1.7 mm, the anisotropic conductive films prepared above were used. After pressing, it was pressurized for 6 seconds at a pressure of 70MPa at a temperature of 180 ℃ to bond five specimens per sample. Adhesion of the finished sample was measured by Shear adhesion at 25 ℃, but after performing five measurements for each sample is shown in Table 1 taking the average value.

In addition, in order to determine the electrical characteristics of the sample, the initial connection resistance was measured five times for each sample, and then the average value was taken to obtain a value. The sample was put under 85 ° C./85% high temperature and high humidity conditions, and 15 hr, 40 hr, 100 hr After taking the sample out every time, the connection resistance was measured five times, and the average value was taken.

Compare Adhesive force (MPa at 25 ℃) Connection resistance (Ω) Example 1 28.3 2.07 Example 2 31.9 1.98 Comparative Example 1 26.6 2.76

Compare Early
Connection resistance (Ω) After 15hr
Connection resistance (Ω) After 40hr
Connection resistance (Ω) After 100hr
Connection resistance (Ω) Example 1 2.07 4.21 6.24 9.52 Example 2 1.98 3.91 5.69 9.39 Comparative Example 1 2.76 4.36 7.41 15.14

As shown in Table 1, in Examples 1 and 2 using a propylene oxide epoxy resin according to the present invention it was confirmed that the initial connection resistance is good compared to Comparative Example 1 using a general BPA epoxy resin. In addition, in the case of Examples 1 and 2 through Table 2, a greater deviation in the reliability of the connection resistance at 15hr, 40hr, 100hr compared to Comparative Example 1 using a general BPA epoxy resin by using a propylene oxide epoxy resin Could be seen.

Through these results, it can be expected that on / off connection defects will be considerably reduced when using a low-temperature fast-curing anisotropic conductive film applied with a propylene oxide epoxy resin when applied to an actual LCD module.

Although the present invention has been described as the preferred embodiment mentioned above, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. The appended claims also cover such modifications and variations as fall within the spirit of the invention.

Claims (15)

a) a propylene oxide-based epoxy resin having two or more epoxy groups in one molecule and having propylene oxide in the main chain of the molecular chain; b) aromatic diazonium salts, aromatic sulfonium salts, aliphatic sulfonium salts, aromatic iodine aluminum salts, phosphonium salts, pyridinium salts, serenium salts, metal arene complexes, silanol / alimunium complexes, benzointocyrreto Cationic latent curing agents selected from (Benzoin tosylato-), o-nitrobenzyltosylto-, ortho-Nitrobenzyl tosylato-, hexafluoroantimonate, hexafluorophosphate, tetra fluoro borate and pentafluorophenyl borate; c) binder resins; d) conductive particles; And e) solvents; Composition for low temperature fast-curing anisotropic conductive film comprising a. The method of claim 1, The composition is a) to 100 parts by weight of a propylene oxide epoxy resin; b) 0.05 to 30 parts by weight of the cationic latent curing agent; c) 20 to 300 parts by weight of the binder resin; d) 1 to 40 parts by weight of conductive particles; And e) 10 to 200 parts by weight of the solvent; Composition for low temperature fast-curing anisotropic conductive film comprising a. The method of claim 1, The propylene oxide epoxy resin is a bisphenol A epoxy resin, a bisphenol F epoxy resin, a polyglycidyl ether epoxy resin, a polyglycidyl ester epoxy resin, an alicyclic epoxy resin, a cresol novolac epoxy resin, a phenol novolac Type epoxy resin, glycidyl amine epoxy resin, glycidyl ester epoxy resin, biphenyl diglycidyl ether epoxy resin, triglycidyl isocyanurate epoxy resin, poly glycidyl methacrylate epoxy resin And a glycidyl methacrylate epoxy resin at least any one selected from the group for low temperature hardening type anisotropic conductive film. The method of claim 1, The propylene oxide-based epoxy resin is a bisphenol A-propylene oxide (BPA-PO) type epoxy resin composition for low temperature fast curing type, characterized in that the resin. 5. The method of claim 4, The bisphenol A-propylene oxide (BPA-PO) type epoxy resin is an epoxy resin to which at least two propylene oxides are added to a bifunctional or polyfunctional bisphenol A type epoxy resin containing at least two glycidyl groups per molecule. A composition for low temperature rapid curing type anisotropic conductive film. The method of claim 1, The propylene oxide-based epoxy resin composition for a low-temperature fast curing type anisotropic conductive film, characterized in that contained in 10 to 90% by weight relative to the total content of the composition. delete delete delete The method of claim 1, The binder resin is polyimide resin, polyamide resin, phenoxy resin, poly methacrylate resin, poly acrylate resin, polyurethane resin, polyester resin, polyester urethane resin, polyvinyl butyral resin, styrene-buty At least one selected from a styrene-styrene (SBS) resin, an epoxy modified body, a styrene-ethylene-butylene-styrene (SEBS) resin, a modified body thereof, and an acrylonitrile butadiene rubber (NBR) and a hydrogenated body thereof; A composition for low temperature fast-curing anisotropic conductive film, characterized in that. The method of claim 1, The weight average molecular weight of the binder resin is 5,000 to 150,000 low-temperature fast curing type composition for anisotropic conductive film, characterized in that. The method of claim 1, The conductive particles may be metal particles including Au, Ag, Ni, Cu, solder or the like; carbon; Particles coated with a metal containing Au, Ag, Ni, etc. using at least one resin selected from polyethylene, polypropylene, polyester, polystyrene and polyvinyl alcohol and modified resin thereof as particles; The composition for a low temperature hardening type anisotropic conductive film, characterized in that any one or more selected from the insulated particles coated by adding an insulating particle thereon. The method of claim 1, The solvent is a low temperature rapid curing type anisotropic conductive film, characterized in that any one or more selected from toluene, xylene, propylene glycol monomethyl ether acetate, benzene, acetone, methyl ethyl ketone, tetrahydrofuran, dimethylformaldehyde and cyclohexanone Composition. The method of claim 1, The composition is a low-temperature fast-curing anisotropic, characterized in that it further comprises 0.01 to 5 parts by weight of any one or more additives selected from polymerization inhibitors, antioxidants, heat stabilizers, curing accelerators and coupling agents based on 100 parts by weight of the propylene oxide-based epoxy resin. Composition for conductive films. A low temperature rapid curing type anisotropic conductive film formed from the composition for anisotropic conductive film of claim 1.