KR20090073369A - Anisotropic conductive film and display element comprising the same - Google Patents

Abstract

An anisotropic conductive film is provided to ensure excellent electrical conductivity and inexpensive manufacturing costs by comprising an adhesive resin and conductive particles having different aspect ratios. An anisotropic conductive film comprises an adhesive resin(1) and conductive particles(2) having different aspect ratios which are distributed within the adhesive resin. The size the conductive particles is 1~8 micron and he aspect ratio is 1~1.5. Two kinds or more of conductive layers are laminated on thepolymer resin particles. The content of the conductive particle is 5~20 parts by weight based on the adhesive resin 100.0 parts by weight.

Description

Anisotropic conductive film and a display element including the same {ANISOTROPIC CONDUCTIVE FILM AND DISPLAY ELEMENT COMPRISING THE SAME}

The present invention relates to an anisotropic conductive film and a display device including the same, and more particularly, to include an adhesive resin and conductive particles distributed in the adhesive resin and having different aspect ratios, thereby increasing the area between the bumps and the conductive particles and reducing the amount of the anisotropic conductive film. The present invention relates to an anisotropic conductive film having excellent electrical flow even with positive conductive particles, and a display device including the same.

In order to electrically connect the connection electrode of an IC circuit board and the terminal of the board mounted on a circuit board, an anisotropic conductive connection should be made. An anisotropic conductive film is used for such anisotropic conductive connection, and the anisotropic conductive film is a z-axis conductive adhesive prepared in the form of an adhesive film by dispersing conductive particles in a thermosetting adhesive and coating the film on a release treated PET film. It means a film and has insulation in the XY plane direction.

As electroconductive particle used for an anisotropic conductive film, metal particle, such as nickel, gold, silver, or particle | grains in which the metal layer was coat | covered with the substrate microparticles | fine-particles are used. At this time, the conductive particles are used to compress and connect the electrodes facing each other to prevent excessive deformation and destruction of the conductive particles due to the pressure applied to the particles and to facilitate gap control between the electrodes. Should have

On the other hand, the gap between bumps has been narrowed recently due to the sophisticated pitch alignment of bumps on panels and driver ICs. In order to maintain the electrical conductivity while decreasing the cross-sectional area of the bumps, the bumps of the driving IC and the electrodes of the panel must be connected by an anisotropic conductive film in which a large number of conductive particles are distributed. However, in addition to difficulty in dispersing a large number of conductive particles, the conductive fine particles account for the highest specific gravity of the anisotropic conductive film manufacturing cost, which is a major cause of the increase in manufacturing cost. Therefore, there is a continuing need in the art for an anisotropic conductive film having excellent electrical conductivity and low manufacturing cost.

The present invention is to solve the problems of the prior art as described above, one object of the present invention is to provide an anisotropic conductive film excellent in electrical conductivity and low in manufacturing cost.

Another object of the present invention is to provide a display element comprising the anisotropic conductive film of the present invention.

One aspect of the present invention for achieving the above object relates to an anisotropic conductive film comprising an adhesive resin and conductive particles distributed in the adhesive resin and having different aspect ratios.

In this case, the conductive particles are formed by laminating two or more kinds of metal conductive layers on the polymer resin fine particles, the size of which is 1 to 8 µm, more preferably 2 to 5 µm.

Another aspect of the present invention for achieving the above object relates to a display element comprising the anisotropic conductive film according to the present invention.

The anisotropic conductive film according to the present invention, the contact area between the bump and the particles is increased, it is possible to provide an anisotropic conductive film with excellent electrical flow is maintained even with a smaller amount of the conductive particles than the conventional manufacturing cost.

The present invention relates to an anisotropic conductive film comprising an adhesive resin, conductive particles distributed in the adhesive resin and having different aspect ratios, and a display device including the same.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail with reference to an accompanying drawing, an Example, etc.

1 is a schematic cross-sectional view of an anisotropic conductive film according to the present invention. Referring to FIG. 1, the anisotropic conductive film according to an embodiment of the present invention includes an adhesive resin 1 and conductive particles 2 distributed in the adhesive resin.

The adhesive resin 1 used in the present invention may include a thermosetting epoxy group resin, a film forming resin and a latent curing agent.

Examples of the thermosetting epoxy group resin include bisphenol A type epoxy resins, bisphenol F type epoxy resins, and noblock type epoxy resins, but are not limited thereto.

As said film formation resin, thermoplastic resins, such as polyester resin, a vinyl resin, an acrylic resin, a polyolefin resin, PVA resin, a polycarbonate resin, a cellulose resin, a ketone resin, a styrene resin, a phenoxy resin, are mixed individually or 2 types or more Can be used.

The latent curing agent used in the present invention may be a commercially available product which microencapsulates the curing agent component such as imidazole and amine as a curing agent that causes a curing reaction by heating and pressing at a curing temperature without causing a reaction at normal temperature.

In addition, the anisotropic conductive film of this invention can mix | blend additives, such as surfactant and a coupling agent, as an adhesive component. In addition, it may further include various participating agents to assist in dispersibility and film formation.

The said electroconductive particle 2 used for this invention is formed by laminating | stacking two or more metal conductive conductive layers, such as nickel, gold, silver, and platinum, on the polymer resin microparticles | fine-particles manufactured by the seed polymerization method.

The size of the conductive particles is preferably in the range of 1 to 8 μm, more preferably in the range of 2 to 5 μm. The polymer seed particles are prepared by copolymerizing two or more kinds of crosslinkable polymerizable monomers having a molecular weight in the range of 1,000 to 30,000. It is preferable to use styrene resin or (meth) acrylate resin as said crosslinkable polymerizable monomer. In this case, the conductive particles 2 preferably have an aspect ratio of 1 to 1.5 in order not to reduce connection reliability. In addition,% which divided the standard deviation of particle diameter by the average particle diameter shall be 20% or less.

The amount of the conductive particles 2 used in the present invention is preferably 5 to 20 parts by weight based on 100 parts by weight of the adhesive resin. If the amount of the conductive particles is 5 parts by weight or less, there is a problem in the conduction resistance characteristics because it is not energized, and if the amount is 20 parts by weight or more, there is a problem such as a short phenomenon due to the excessive amount of the conductive particles.

The anisotropic conductive film according to one embodiment of the present invention is formed by dispersing the above-described adhesive resin (1) and the conductive particles (2) in a suitable solvent, then coating by a conventional method used in the art.

Examples of the polar solvent used in the present invention include ester solvents such as methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate, ketone solvents such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclonucleanone, ethanol, propanol, Alcohol solvents, such as butanol, etc. are mentioned, As a nonpolar solvent, benzene, toluene, ethylbenzene, etc. are mentioned, but it is not limited to this.

Another aspect of the present invention relates to a display device comprising the anisotropic conductive film according to the present invention.

2 is a schematic cross-sectional view of a display device according to an exemplary embodiment of the present invention. Referring to FIG. 2, the display element may have an increased contact area between the bump 3 and the conductive particles 2, thereby maintaining excellent electrical flow even with a smaller amount of conductive particles than before.

Hereinafter, the present invention will be described in more detail with reference to examples of the present invention, which is only for the purpose of illustrating the present invention and should not be construed as limiting the protection scope of the present invention.

Example 1

First, 45 g of phenoxy resin (YP-50), 45 g of epoxy resin (Cell Chem, Ebicoat 630), and 10 g of HX3741 were mixed with a latent curing agent to prepare an adhesive resin.

In addition, to prepare the conductive particles, first, 30 g of styrene monomer and 30 g of 2,2 azobis as a polymerization initiator were polymerized in a mixture of methanol and ultrapure water, and then dried through a freeze dryer to obtain seed particles in powder form. Subsequently, 3 g of seed particles prepared in 600 g of sodium lauryl sulfate aqueous solution are added, and 100 g of styrene and 1.5 g of benzoyl peroxide initiator are mixed in 300 g of sodium lauryl sulfate aqueous solution. The seed particle dispersion was added thereto and 500 g of polyvinyl alcohol aqueous solution was added to polymerize. After the polymerization was completed, the polymer fine particles were obtained in a powder state by vacuum drying. Electroless nickel plating was performed on the obtained polymer fine particles, followed by nickel substitution plating. It was made to form a gold plating layer, and the electroconductive particle which becomes a double metal layer was formed.

Subsequently, 7 g of conductive particles prepared as described above are dispersed on the adhesive resin. A binder having conductive particles dispersed therein was coated to prepare an anisotropic conductive film having a thickness of about 20 μm. While the anisotropic conductive film was manufactured, the anisotropic conductive film was overlapped with each other while the IC chip having a 26 μm pitch and the ITO pattern designed on the glass substrate of the liquid crystal display were connected to each other, so that 10 sets were performed at 180 ° C. and 20 kgf / cm 2 for 10 seconds. Heat compression.

Example 2

A sample was prepared in the same manner as in Example 1, except that 10 g of the conductive particles prepared above was added to the adhesive resin.

Comparative Example 1

A sample was prepared in the same manner as in Example 1, except that 7 g of conductive particles having a size of 4 μm plated with nickel and gold were added to the polymer in the adhesive resin.

Comparative Example 2

A sample was prepared in the same manner as in Example 1, except that 10 g of conductive particles having a size of 4 μm plated with nickel and gold were added to the polymer in the adhesive resin.

Electrical property evaluation

The conduction resistance and insulation resistance of the LCD panel manufactured as described above were measured using a DC power supply, a nanovolt meter, and the like, and are shown in Table 1 below.

Evaluation criteria (conduction resistance)

O: resistance 10 ⁸ Ω or more

X: resistance less than 10 ⁸ Ω

Evaluation criteria (insulation resistance)

O: resistance 10 ⁸ Ω or more

X: resistance less than 10 ⁸ Ω

TABLE 1

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Amount of conductive particles 7 10 7 10 Conduction resistance O O X O Insulation Resistance O O O O

As shown in Table 1, using the conductive particles of the present invention, it was confirmed that sufficient electrical connection is possible even with a smaller amount of conductive particles. This has been shown to improve the contact area of the prepared conductive particles can maintain a constant conduction resistance even with a small amount of conductive particles while maintaining the insulation resistance.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, the present invention is not limited to the above-described embodiments, and many modifications are made by those skilled in the art to which the present invention pertains within the scope of the technical idea of the present invention. This possibility will be self-evident.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing of the anisotropic conductive film manufactured using the electroconductive particle of this invention.

2 is a schematic cross-sectional view of a display element including the anisotropic conductive film of the present invention.

** Description of the main symbols in the drawings **

1: adhesive resin,

2: electroconductive particle,

3: bump,

4: ITO

Claims (9)

An anisotropic conductive film comprising an adhesive resin and conductive particles distributed in the adhesive resin and having different aspect ratios. The anisotropic conductive film according to claim 1, wherein the conductive particles have a size of 1 to 8 µm. The anisotropic conductive film of claim 2, wherein the conductive particles have a size of 2 to 5 μm. The anisotropic conductive film according to claim 1, wherein the conductive particles have an aspect ratio of 1 to 1.5. The anisotropic conductive film according to claim 1, wherein the conductive particles are formed by laminating two or more kinds of metal conductive layers on polymer resin fine particles. According to claim 1, wherein the content of the conductive particles is an anisotropic conductive film, characterized in that 5 to 20 parts by weight based on 100 parts by weight of the adhesive resin. 6. The anisotropic conductive film of claim 5, wherein the metal conductive layer is selected from the group consisting of nickel, gold, silver, and platinum. The anisotropic conductive film according to claim 1, wherein the adhesive resin is a resin component containing a thermosetting epoxy group. The display element containing the anisotropic conductive film of any one of Claims 1-8.

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