KR100924531B1 - Method for preparing anisotropic conductive film for ultra-fine pitch by sol-gel process - Google Patents

Abstract

The present invention relates to an anisotropic conductive film and a method for producing the same, specifically, nano-sized silica particles produced from a sol-gel reaction of an alkoxy silane to an adhesive component comprising a resin component and a latent curing agent, and The manufacturing method of the anisotropic conductive film containing adding and disperse | distributing electroconductive particle, and the anisotropic conductive film manufactured by this are related. The anisotropic conductive film produced by the present invention is characterized in that the insulation between the conductive balls is improved, the electrical short phenomenon between bumps is prevented.

Anisotropic Conductive Film, Conductive Particles, Insulation, Solgel, Silica, ACF

Description

Method for preparing an anisotropic conductive film for ultra-fine pitch using the sol-gel method {method for preparing anisotropic conductive film for ultra-fine pitch by sol-gel process}

The present invention relates to an anisotropic conductive film (ACF) capable of implementing an ultra-fine pitch COG (Chip on Glass) technology used for electrical connection of a driving IC for driving a liquid crystal display (LCD). In particular, the present invention relates to an anisotropic conductive film comprising adding and dispersing silica particles generated from a sol-gel reaction of an alkoxy silane and conductive particles to an adhesive component including a resin component and a latent curing agent. It relates to a manufacturing method and an anisotropic conductive film produced thereby.

An anisotropic conductive film means a z-axis conductive adhesive film prepared in the form of an adhesive film by dispersing conductive fine particles in an adhesive and coating on a release-treated PET film, and has insulation in the X-Y plane direction.

Recently, as LCD panels become larger and higher in quality, they tend to be larger in size and smaller in electrode. As a result, the area of electrodes or bumps to which the LCD panel and the driving IC can be electrically connected is reduced, and the gap between the electrodes is reduced. Therefore, there is a need for an anisotropic conductive film that must electrically connect a larger number of electrodes within a limited area.

However, in the case of using an anisotropic conductive film having a large content of conductive balls in a drive circuit having a fine pitch, the inflow of conductive particles increases into the space between bumps, which causes agglomeration and contact between the conductive particles. This may cause an electrical short between bumps.

In order to prevent such electric short phenomenon, Hidachi Chemical Co., Ltd. adopted a double-layer anisotropic conductive film that minimizes the amount of conductive particles flowing into the space between bumps by contacting a resin film without conductive particles on the bump side. A thin insulating coating was applied to the balls to maintain the insulating properties even when the conductive balls contacted each other.

However, according to the method of Hitachi Hwasung Co., Ltd., it is highly likely to increase the production cost due to the complicated structure by coating with two layers. Sony's method also reduces the insulation between the particles, but it can also weaken the conductivity between the bumps and the pads.

The present invention is to solve the problems of the prior art as described above, the object of the present invention is convenient coating workability due to a single coating, the insulation is improved due to the dispersion of nano-sized silica particles, durability and resistance It is to provide an anisotropic conductive film with improved wettability and a method of manufacturing the same.

In order to achieve the above object, one aspect of the present invention is (a) an adhesive component comprising a resin component and a latent curing agent, (b) nano-sized silica particles produced from the sol-gel reaction of the alkoxy silane And (c) adding and dispersing the conductive particles to provide a method for producing the anisotropic conductive film.

A second aspect of the present invention for achieving the above object, an anisotropic conductive film comprising 100 parts by weight of the adhesive component containing a resin component and a latent curing agent, 1 to 20 parts by weight of silica particles, and 1 to 30 parts by weight of conductive particles To provide.

According to the manufacturing method of the anisotropic conductive film according to the present invention as described above, the coating workability is convenient due to only one coating, and the anisotropic conductive film having improved insulation due to dispersion of silica particles generated from the sol-gel method of the alkoxy silane. It can manufacture. This is difficult to control the dispersion degree due to the rapid increase in viscosity when the silica particles are prepared by simply stirring the conductive particles, but when the silica particles are manufactured from the sol-gel method, the size of the particles produced is tens of nanometers, leading to rapid increase in viscosity. This is because the dispersion degree is easy to adjust because it does not occur. In addition, it is also easy to manufacture an anisotropic conductive film having improved moisture resistance at the time of reliability evaluation due to the dispersion of nano-sized silica particles.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

One aspect of the invention is (a) an adhesive component comprising a resin component and a latent curing agent, (b) silica particles generated from the sol-gel reaction of alkoxy silane, and (c) conductive particles are dispersed The manufacturing method of the anisotropic conductive film containing what is made.

Resin component

Examples of the resin component used in the adhesive component (a) of the present invention include an epoxy resin, a phenoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a noblock type epoxy resin, a polyester resin, a vinyl resin, an acrylic resin, and a polyolefin. Thermosetting resins, such as resin, PVA resin, a polycarbonate resin, a cellulose resin, a ketone resin, and a styrene resin, can be used combining 2 or more types of thermoplastic resins.

Latent curing agents

The latent curing agent used for the adhesive component (a) of the present invention means a curing agent that does not react at room temperature but causes a curing reaction by heating and pressing at a curing temperature, and a curing agent component such as imidazole, amine, etc. Commercially available products can be used as encapsulated, but the present invention is not limited thereto. The latent curing agent is used 10 to 40 parts by weight based on 100 parts by weight of the (a) adhesive component, preferably 20 to 30 parts by weight. When the latent curing agent is in the above range, the adhesive strength can be maintained with an appropriate curing density, and the occurrence of uncured parts is reduced, thereby improving connection reliability.

Other additives

In addition, additives, such as surfactant and a coupling agent, can be further mix | blended with the adhesive component of this invention.

The sol-gel solution used in the sol-gel reaction of the present invention contains an alkoxy silane, a solvent and a catalyst.

Alkoxy Silane

In the present invention, the alkoxy silane used in the sol-gel solution may be used by mixing one or two or more kinds of Si (OR) _x (x is a natural number, R is an alkyl group having 1 to 10 carbon atoms), and two or more alkoxy silanes are mixed. It is possible to adjust the degree of the content of silica particles generated from the sol-gel reaction rate and the sol-gel method by using.

The alkoxy silane may preferably include Tetraethylorthosilicate (TEOS), methyltrimethoxysilane (MTMS), or a combination thereof, but is not limited thereto.

menstruum

The solvent used in the sol-gel solution in the present invention is, as a polar solvent, 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; And alcohol solvents such as ethanol, propanol and butanol, and the like, and benzene, toluene, ethylbenzene, and the like can be used as the nonpolar solvent.

catalyst

In addition, it is preferable to use a small amount (about 0.001 parts by weight) of an acid catalyst such as hydrochloric acid or an amine-based basic catalyst as the catalyst for the sol-gel reaction.

The sol-gel solution is used such that the content of the silica particles generated from the sol-gel reaction of the alkoxy silane is preferably 1 to 20 parts by weight, more preferably 10 to 20 parts by weight based on 100 parts by weight of the adhesive component. When the content of the silica particles is in the above range, the size of the silica particles generated from the sol-gel reaction is on the order of tens of nanometers, that is, 10 to 50 nm, so that stirring is easy without a sudden increase in viscosity when stirring with the conductive particles in the adhesive. .

Conductive particles

It is preferable that the electroconductive particle of this invention uses particle | grains plated with nickel, gold, platinum, etc. in a polymer, or metal particle, such as nickel, gold, platinum, copper. It is preferable that it is 1-8 micrometers, and, as for the magnitude | size of the said electroconductive particle, it is more preferable that it is 2-5 micrometers. When the size of electroconductive particle is the said range, dispersion degree is favorable and the electroconductivity of the produced anisotropic conductive film is maintained.

The content of the conductive particles is 1 to 30 parts by weight, preferably 5 to 20 parts by weight based on 100 parts by weight of the adhesive component (a). When the content of the conductive particles is in the above range, short generation due to adhesion of the conductive particles is suppressed while maintaining low resistance.

The second aspect of the present invention is anisotropic, prepared by the above method, comprising 100 parts by weight of an adhesive component comprising a resin component and a latent curing agent, 1 to 20 parts by weight of silica particles, and 1 to 30 parts by weight of conductive particles. It relates to a conductive film.

In this invention, the said resin component, latent hardening | curing agent, a silica particle, and electroconductive particle are the same as what was demonstrated by the manufacturing method of the said anisotropic conductive film.

The silica particles of the present invention preferably have a size of 10 to 50 nm, the surface adhesion of the anisotropic conductive film is reduced, the poor adhesion is minimized in the above range.

It is preferable that the anisotropic conductive film which concerns on this invention has an insulation resistance of 10 <^8> Pa or more.

Hereinafter, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited to the following examples.

In Examples and the like, evaluation items were measured through evaluation of electrical characteristics such as conduction and insulation resistance measurement of panels bonded with the anisotropic conductive film prepared in the present invention.

Example  One

The present invention will be described with reference to the following drawings. In Figure 1 (1) represents an epoxy binder and the composition is as follows.

Epoxy binder was prepared by mixing 45 parts by weight of phenoxy resin (YP-50) from Dongbu Chemical, 45 parts by weight of epoxy resin (Ebicoat 630) from Cell Chemicals, and 10 parts by weight of latent curing agent (HX3741). do. To this, 5 parts by weight of a sol-gel solution, which was stirred at low temperature for about 2 hours using TEOS as an alkoxy silane, ethanol and methanol as a solvent, and hydrochloric acid as a catalyst in a weight ratio of 3: 1: 0.001, was added. 10 parts by weight of particles are dispersed. The anisotropic conductive film having a thickness of 20 μm was prepared by applying the above solution onto a release film and drying according to a conventional method. 10 sets of anisotropic conductive films were overlapped with each other between the IC chip having a 26 μm pitch and the ITO pattern designed on the glass substrate of the liquid crystal display so as to overlap each other for 10 seconds at 180 ° C. and 20 kgf / cm 2. heat press). The conduction resistance and insulation resistance of the LCD panel manufactured thereby were measured and shown in Table 2.

Example  2

A sample was prepared in the same manner as in Example 1, except that 10 parts by weight of the sol-gel solution reacted from TEOS was used as shown in Table 1 below. The conduction resistance and insulation resistance of the LCD panel thus produced were measured and shown in Table 2.

Example  3

A sample was prepared in the same manner as in Example 1, except that 5 parts by weight of the sol-gel solution mixed and reacted at a 1: 3 ratio of TEOS and MTMS was used as shown in Table 1 below. The conduction resistance and insulation resistance of the LCD panel thus produced were measured and shown in Table 2.

Example  4

As shown in Table 1, a sample was prepared in the same manner as in Example 1, except that 10 parts by weight of the sol-gel solution mixed and reacted at a ratio of 1: 3 of TEOS and MTMS was used. The conduction resistance and insulation resistance of the LCD panel thus produced were measured and shown in Table 2.

Comparative example

As shown in Table 1, a sample was prepared by dispersing a conductive ball in an epoxy binder without a sol-gel solution. The conduction resistance and insulation resistance of the LCD panel thus produced were measured and shown in Table 2.

TABLE 1

Example 1 Example 2 Example 3 Example 4 Comparative example Conductive Particles (4 μm) 8 8 8 8 8 TEOS Sol Gel Solution 5 10 1.25 2.5 - MTMS Sol Gel Solution - - 3.75 7.5 -

TABLE 2

Example 1 Example 2 Example 3 Example 4 Comparative example Conduction resistance - A A B - Insulation Resistance D C D C D

Note 1) Conducting resistance: A-resistance 10 ⁸ Ω or more, B-resistance 10 ⁸ Ω or less

Note 2) Insulation resistance: C-resistance 10 ⁸ Ω or more, D-resistance 10 ⁸ Ω or less

As shown in Table 2, the anisotropic conductive film of the present invention showed a significant improvement in insulation as the sol-gel solution is added to the existing anisotropic conductive film. This is because the silica particles generated from the added sol-gel solution have excellent insulating properties as inorganic substances, and due to the dispersibility of nano-sized silica particles, they do not aggregate between conductive particles, thereby improving insulation resistance while maintaining conduction resistance. Explained as shown.

1 illustrates an anisotropic conductive film with improved insulation according to the present invention.

Figure 2 shows the reaction until the production of silica particles by the sol-gel method from the alkoxy silane according to the present invention.

Figure 3 shows the chemical structural formulas of TEOS (Tetraethoxysilane) and MTMS (Methyltrimethoxysilane) which is an alkoxy silane used in the present invention.

<Description of Symbols for Main Parts of Drawings>

(1) epoxy binder

(2) Silica Particles Produced by Sol-Gel Method

(3) conductive particles

(4) bump

(5) ITO

Claims (12)

10 nm to 50 resulting from (a) an adhesive component comprising a resin component and a latent curing agent, and (b) a sol-gel reaction of alkoxy silane which is (TE) tetraethylorthosilicate (TEOS), methyltrimethoxysilane (MTMS) or a combination thereof. A method for producing an anisotropic conductive film comprising adding and dispersing nano-sized silica particles in the nm range and (c) conductive particles. The nano-size silica particles produced from the sol-gel reaction of the (b) alkoxy silane based on 100 parts by weight of the adhesive component including the resin component and the latent curing agent are 1 To 20 parts by weight, and the (c) conductive particles are 1 to 30 parts by weight, wherein the method for producing an anisotropic conductive film. The manufacturing method of the anisotropic conductive film of Claim 1 whose size of the said electroconductive particle is 1-8 micrometers. The manufacturing method of the anisotropic conductive film of Claim 1 whose size of the said electroconductive particle is 2-5 micrometers. delete delete The anisotropic conductive film manufactured by the method of Claim 1 containing 100 weight part of adhesive components containing a resin component and a latent hardener, 1-20 weight part of silica particles, and 1-30 weight part of electroconductive particles. The anisotropic conductive film according to claim 7, wherein the latent curing agent is 10 to 40 parts by weight. The anisotropic conductive film of claim 7, wherein the silica particles have a size of 10 to 50 nm. The size of the said electroconductive particle is 1-8 micrometers, The anisotropic conductive film of Claim 7 characterized by the above-mentioned. The size of the said electroconductive particle is 2-5 micrometers, The anisotropic conductive film of Claim 7 characterized by the above-mentioned. The anisotropic conductive film according to claim 7, wherein the insulation resistance of the anisotropic conductive film is 10 ⁸ kPa or more.

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