KR100861010B1 - Insulated Conductive Particles for Anisotropic Conduction and Anisotropic Conductive Film Using Same - Google Patents

Abstract

The insulating conductive particles according to the present invention may include a substrate particle 11, a first metal layer 12 plated on the surface of the substrate particle, a protrusion 13 formed discontinuously on the surface of the first metal layer, and the protrusion formed thereon. The protruding conductive particles 10 made of the second metal layer 14 formed on the surface of the first metal layer; And insulating particles 2 discontinuously fixed to the surface of the protruding conductive particles, wherein the diameter of the insulating particles is larger than the height of the protrusion 13 formed on the surface of the first metal layer. It is in the range of 20% or less of the diameter of (10), and when the said insulating particle 2 is connected to an electrode, it is characterized by the protrusion electrically conductive particle and an electrode being electrically connected by deviating from an original position. This invention contains the anisotropically conductive adhesive film and electrical connection structure containing the said insulating conductive particle.

Anisotropic conductive adhesive film, insulating conductive particles. Insulation Particle, Protruding Particle

Description

Insulated Conductive Particles for Anisotropic Conduction and Anisotropic Conductive Film Using Same}

1 is a conceptual diagram illustrating a process of manufacturing insulating conductive particles according to the present invention step by step.

2 is a schematic front view (a) and sectional view (b) of insulating conductive particles according to the present invention.

3 is a schematic cross-sectional view of an anisotropic conductive film prepared using insulating conductive particles according to the present invention.

4 is a schematic cross-sectional view showing a state before the anisotropic conductive film according to the present invention is pressed between substrates.

5 is a schematic cross-sectional view showing a state in which the anisotropic conductive film according to the present invention is pressed and electrically connected between substrates.

6 is a schematic cross-sectional view showing a state in which insulating conductive particles according to the present invention are connected to a bump electrode of a circuit board.

* Brief description of the major symbols in the drawings *

1: insulating conductive particle 2: insulating particle

3: anisotropic conductive adhesive film 4, 5: circuit board

10: projection conductive particle 11: substrate particle

12: first metal layer 13: protrusion

14: second metal layer 41, 51: bump electrode

Field of invention

The present invention relates to insulating conductive particles. More specifically, the present invention, when the metal plating on the surface of the substrate particles made of a polymer resin, and then formed a projection using the projection particles on the surface, and when the metal plating and the insulating fine particles are discontinuously attached to each other when pressed between the electrodes It relates to insulating conductive particles which are conductive only in the pressing direction and have insulation in the horizontal direction. The present invention includes an anisotropic conductive film and an electrical connection structure using the above insulating conductive particles.

Background of the Invention

As the technology of liquid crystal displays (LCDs) has been developed, the resolution of the display quality has been improved and the pixel pitch has been reduced. As a result, the number of printed leads per unit area on the substrate has been increased. There is a trend. In line with these technical requirements, circuit packaging technology for connecting LCD panels, driver ICs, and printed circuit boards (PCBs) has been developed. It is developing in various ways according to the fine pitch.

Particularly, among the LCD mounting technologies, a method of connecting an electrical connection between a liquid crystal panel and a printed circuit board by a COF (chip on film) method using an anisotropic conductive film (ACF) is used. There is this. In this method, a mounting method in which a connection with a printed circuit board is connected to an ACF using a flexible printed circuit board (FPC) is used. In addition, as a next generation LCD mounting method, a method of directly connecting a driver IC bare chip to a pattern using an ACF on an ITO pattern formed on an LCD glass panel has been proposed.

A general anisotropic conductive film is located between the connecting parts, heated and pressed, and the terminals adjacent in a direction parallel to the substrate (hereinafter referred to as the 'xy plane direction') are not electrically connected, but in a vertical direction (here 'z'). Adjacent terminals in the axial direction are conducted. This conductive function is achieved by conductive particles dispersed in the adhesive material in the film, which is made by coating a metal material on the core. The manufacturing method of such electroconductive particle is disclosed by Unexamined-Japanese-Patent No. 52-147797, 61-277104, 1-225776, 1-247501, 4-147513, etc.

In the case of the conductive particles composed only of the plating layer on the core material (core), there is a disadvantage that the risk of short circuit is always exposed between adjacent terminals in the xy plane direction in the precision circuit. To overcome this, Japanese Patent Application Laid-Open Nos. 8-335407, S62-2,183, 3-3-46774, 4-174980, 6-060712, 7-105716, 4-259766, 3-112011 For example, the insulating layer made of a thin thermoplastic resin layer or a thermosetting resin layer is attached to the outer layer of the conductive particles or the micro insulating particles are attached to each other. Particles that are made to be energized and not affected are suggested insulating conductive particles that maintain an insulating layer to prevent shorting between particles or between electrodes.

In addition, Japanese Patent Application Laid-Open Nos. 8-335407, S 6262183, and 6-060712 employ a physical and chemical method on the surface of conductive particles to form an insulating layer using a polymer resin layer, thereby shorting between particles or electrodes. It has been proposed a technique for preventing the, and until recently, insulating conductive particles insulated in this manner has been mainly used.

Recently, however, when the spherical conductive particles or the insulated spherical conductive particles are dispersed in the adhesive material in the film and then heated and compressed, the particles are moved left and right by upper and lower stresses and are driven between the neighboring electrodes and the electrodes. The amount of conductive particles remaining between electrodes decreases, which may cause unstable connection resistance.In addition, if the distance between electrodes is caused by external shock or temperature after crimping, electrical contact failure occurs, resulting in long-term reliability of the electrical connection. As a significant adverse effect on the use of the projection-type conductive particles in the form of protrusions protruding on the surface instead of spherical conductive particles is increasing.

The projections of the general projection-type conductive particles vary slightly depending on the type of the conductive particles, but usually protrude at a height of about 5 to 10% of the particle diameter of the conductive particles, and the average number of projections per particle is maintained at 30 to 50 pieces. do. Such protrusion-type conductive particles have a small amount of movement between stress at high temperature and pressure, and thus have a large amount of residual amount between the upper and lower electrodes to realize a stable connection resistance value, and even when the upper and lower electrodes are separated by an impact after compression, the current flows through the protrusion. The possibility of poor contact can be reduced. In addition, the connection reliability can be improved by removing the phenomenon that the electrical connection resistance value rises by the oxide film generated on the surface of the connection electrode through the oxide film.

For this reason, the use of protruding conductive particles is rapidly increasing. However, when the insulating treatment is performed on the protruding conductive particles in the form of protrusions protruding from the surface, the insulating layer is excessive on the surface of the conductive particles under the influence of the protruding protrusions. On the contrary, the protruding portion is exposed to the outside of the insulating layer, and loses insulation due to contact of protruding protrusions between particles during heating and pressing, thereby causing a short circuit problem.

Therefore, in order to solve the above problems, it is necessary to maintain the function of the uniform insulating layer forming projection for the protruding conductive particle surface layer, and to consider an insulation concept that can prevent a short circuit of current between neighboring particles.

Accordingly, the present inventors have come to develop insulating conductive particles, anisotropic conductive adhesive films using the same, which can solve the above-mentioned problems by immobilizing the insulating particles discontinuously on the projection-type conductive particles and suggesting the height of the projections appropriately.

SUMMARY OF THE INVENTION An object of the present invention is to prepare protruding conductive particles and to discontinuously fix the insulating particles on the surface thereof, thereby making it easy to remove the insulating layer when connecting to the electrode, thereby providing insulating conductive particles having excellent conductivity in the z-axis direction and insulating properties in the xy plane direction. It is to provide.

Another object of the present invention is to provide insulating conductive particles having excellent insulation reliability, current carrying reliability and solvent resistance during electrical connection by proposing an appropriate size range of the projection conductive particles.

It is another object of the present invention to provide insulating conductive particles suitable for fine-pitching of wiring patterns and low temperature curing of anisotropic conductive adhesive films.

Still another object of the present invention is to provide an anisotropic conductive adhesive film using the above insulating conductive particles.

Still another object of the present invention is to provide an electrical connection structure using the anisotropic conductive adhesive film.

The above and other objects of the present invention can be achieved by the present invention described below.

Summary of the Invention

The insulating conductive particles according to the present invention may include a substrate particle 11, a first metal layer 12 plated on the surface of the substrate particle, a protrusion 13 formed discontinuously on the surface of the first metal layer, and the protrusion formed thereon. The protruding conductive particles 10 made of the second metal layer 14 formed on the surface of the first metal layer; And insulating particles 2 discontinuously fixed to the surface of the protruding conductive particles, wherein the diameter of the insulating particles is larger than the height of the protrusion 13 formed on the surface of the first metal layer. It is in the range of 20% or less of the diameter of (10), and when the said insulating particle 2 is connected to an electrode, it is characterized by the protrusion electrically conductive particle and an electrode being electrically connected by deviating from an original position.

Preferably, the first metal layer is made of nickel, and the upper second metal layer is made of gold.

The protruding portion forms protruding particles on the surface of the first metal layer by a mechanical / composite method.

The protruding particles preferably have a core-shell structure consisting of a hard core region and a soft shell region.

It is preferable that the average particle diameter of the substrate particle which comprises the said projection electroconductive particle 10 is 1-20 micrometers, and is 100 kPa or less of connection resistance.

The insulating particles 2 are preferably core-shell polymer resin particles composed of a hard core region and a soft shell region.

The hard core regions of the insulating particles 2 include divinylbenzene, 1,4-divinyloxybutane, divinyl sulfone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, and trially tree. Allyl compounds, such as melitate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri ( Meth) acrylate, pentaaryl tritol di (de) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) Monomers of acrylic compounds selected from the group consisting of acrylates and glycerol tri (meth) acrylates are radically polymerized crosslinked polymer microparticles,

The soft shell region includes unsaturated carboxylic acid, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth), including (meth) acrylic acid, maleic acid, itaconic acid, and the like. Acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, allyl glycidyl ether, 2-isopropenyl 2-oxazoline, diethylaminoethyl (meth) acrylate, alkyl (meth) acrylamide, 4-vinylpyridine, N-methylol acrylamide, dimethylaminopropyl (meth) acrylamide, (meth) acryloyl Preference is given to polymers of monomers selected from the group consisting of chloride, (meth) acrylonitrile, styrene sulfonic acid, sodium styrene sulfonate and sulfonic acid derivatives thereof.

The present invention includes an anisotropic conductive adhesive film in which the insulating conductive particles are dispersed on a thermosetting resin.

Moreover, this invention includes the electrical connection structure which crimped | bonded between the electrodes of the board | substrate which the said anisotropically conductive adhesive film opposes.

Hereinafter, with reference to the accompanying drawings, the contents of the present invention will be described in detail.

Detailed Description of the Invention

1 is a conceptual diagram illustrating a process of manufacturing insulating conductive particles according to the present invention step by step, Figure 2 is a schematic front view (a) and cross-sectional view (b) of the insulating conductive particles according to the present invention.

The insulating conductive particles according to the present invention have a shape as shown in FIG. 2 through the process of FIG. 1. That is, the insulating conductive particles of the present invention are produced by discontinuously immobilizing the insulating particles 2 on the surface of the protruding conductive particles 10.

Looking at the manufacturing process, first the first metal layer 12 is plated on the surface of the substrate particle 11 shown in Figure 1 (a) as shown in Figure 1 (b), and then on the surface of the first metal layer As shown in FIG. 1C, the protrusion 13 is discontinuously formed. The second metal layer 14 is plated on the surface of the first metal layer 12 on which the protrusions 13 are formed, as shown in FIG. The insulating conductive particles 1 are produced by discontinuously immobilizing the insulating particles 2 on the surface of the protruding conductive particles 10 thus prepared. When the conductive particles 1 thus produced are heated and pressed between the electrodes, the insulating particles 2 discontinuously fixed to the surface are separated from their original positions so that the electrodes and the protruding conductive particles 10 are electrically connected to each other. do.

The substrate particles 11 are spherical polymer resin particles. Examples of the polymer resin that can be used as the substrate particles 11 include phenol resins, urea resins, melamine resins, fluorine resins, polyester resins, epoxy resins, silicone resins, polyimide resins, polyurethane resins, propylene resins, polyolefin resins, and the like. Such as thermosetting polymer resins, or polyethylene resins, polypropylene resins, polybutylene resins, polymethacrylic resins, methylene resins, polystyrene resins, acrylonitrile-styrene resins, acrylonitrile-styrene-butadiene resins, vinyl resins, Any one of vinylbenzene resin, polyamide resin, polyester resin, polycarbonate resin, polyacetal resin, pioneoma resin, polyethersulfone resin, polyphenyloxide resin, polyphenylene sulfide resin, polysulfone resin, and polyurethane resin Phosphorus thermoplastic or thermosetting resins are preferred. The substrate particles are the core material fine particles synthesized by the emulsion polymerization method of the polymer resin as described above.

In the present invention, the size of the substrate particle 11 is preferably in the range of 1 to 20 µm.

In the first metal layer 12, a conductive metal such as nickel is plated on the surface of the substrate particle 11. Plating methods, such as nickel, use well-known plating methods, such as an electroless plating method. The thickness of the first metal layer is 0.1 to 20% of the diameter of the substrate particle 11, of which 0.1 to 20% range is preferred.

The protrusions 13 discontinuously fix the protrusion particles to the surface of the first metal layer 12 to form protrusions on the surface of the first metal layer.

The protruding particles are core-shell type fine particles consisting of a hard core region and a soft shell region having adhesion. The core-shell shaped projection particles 13 are attached to the surface of the first metal layer discontinuously by a mechanical / composite method or the like to form the projections 13. By the mechanical-complexing method, the soft shell region is deformed in its form and flows toward the surface of the first metal layer 12 to form an adhesive forming the protrusions 13. Examples of the resin constituting the hard region and soft inversion are the same as in the case of the insulating particles 2 described below.

In the present invention, the height of the protrusions 13 is in the range of 1 to 20% with respect to the diameter of the substrate particles, of which 5 to 10% is preferred.

The second metal layer 14 is formed by plating a highly conductive metal on the surface of the first metal layer 12 on which the protrusions 13 are formed. In consideration of conductivity, the second metal layer is preferably plated, but may be composed of a mixed layer such as nickel / gold as necessary. The thickness of the second metal layer is 0.1 to 20% of the diameter of the substrate particle 11, of which 0.1 to 20% range is preferred.

In this way, when the second metal layer is formed, the protruding conductive particles 10 having overall conductivity are completed. The insulating conductive particles are produced by discontinuously fixing the insulating particles 2 on the surface of the protruding conductive particles 10.

Since the insulating particle 2 is used for manufacture of an anisotropically conductive adhesive film, it must have insoluble with respect to a solvent. The diameter of this insulating particle 2 is larger than the height of the protrusion part 13 of the surface of a 1st metal layer, and has a range within 20% of the diameter of the protrusion conductive particle 10. If the diameter of the insulating particles 2 is smaller than the height of the protrusions 13, it is difficult to ensure insulation in the xy plane direction, and when the diameter of the insulating particles 2 exceeds 20% of the diameter of the protrusion-type conductive particles 10, It is difficult to ensure the electrical conductivity in the z-axis direction at the time of connection.

The insulating particles 2 are core-shell polymer polymer particles composed of a hard core region and a soft shell region.

The hard core regions of the insulating particles 2 are divinylbenzene, 1,4-divinyloxybutane, divinyl sulfone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, and trially trimelli Allyl compounds, such as a tate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, penta erythritol tetra (meth) acrylate, penta aryl tritol tri (meth) ) Acrylic acid, penta aryl tritol di (dec) acrylate, trimethylol propane tri (meth) acrylate, dipenta erythritol hexa (meth) acrylate, dipenta aryl tritol penta (meth) acrylate The crosslinked polymer microparticles | fine-particles which the monomer of any one of acrylic compounds, such as and glycerol tri (meth) acrylate, radically polymerized are used.

The soft shell region of the insulating particle 2 includes unsaturated carboxylic acid, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydride including (meth) acrylic acid, maleic acid, itaconic acid, and the like. Oxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, allyl glycidyl ether, 2-isopropenyl-2-oxazoline, diethylaminoethyl (meth) acrylate, alkyl (meth) acrylamide, 4-vinylpyridine, N-methylol acrylamide, dimethylaminopropyl (meth) acrylamide, ( Meta) acryloyl chloride, (meth) acrylonitrile, styrenesulfonic acid, sodium styrenesulfonate, and a sulfonic acid derivative thereof.

In the present invention, an example of a method of immobilizing the insulating particles 2 on the surface of the protruding conductive particles 10 is a dry method using physical / mechanical friction, or spray drying, vacuum deposition coating, core shell fashion ( core shell fashion), wet fixing, and the like. It may also be manufactured using a hybridization system of Ilbok Nara Machinery Co., Ltd. At this time, the insulating particles 2 are mixed with the protruding conductive particles 10 at a ratio of 5 to 15%.

The insulating particles 2 fixed by the above method should not be separated from the second metal layer in the crude liquid with the curable epoxy resin, and the shape should be maintained at a temperature of 130 to 200 ° C. In addition, the diameter of the insulating particles 2 is larger than the projections 14 and is made 20% or less than the diameter of the projection-type conductive particles 10, so that the insulating particles on the surface of the metal layer in the xy plane direction with respect to the pressure in the z-axis direction. Deviation of In addition, the fixed insulating fine particles 2 are fixed at a coverage of 0.1 to 99.9% of the surface area of the projection conductive particles 10, and a coverage of 60 to 90% is preferable. More preferably, it is 80 to 99%.

3 is a schematic cross-sectional view of an anisotropic conductive film prepared using insulating conductive particles according to the present invention.

As shown in Fig. 3, the present invention provides an anisotropic conductive adhesive film 3 obtained by dispersing insulating conductive particles 1 on a thermosetting resin.

The insulating conductive particles 1 produced by the present invention are dispersed on the adhesive component, and the insulating particles 2 must be held on the surface of the metal layer of the protruding conductive particles 10 without leaving the insulating particles 2 on the film 3. In addition, the insulating particles must not dissolve and dissolve in the adhesive component. Thus, the insulating conductive particles 1 dispersed in the film 3 have a form in which the insulating particles 2 are discontinuously immobilized on the conductive metal layer having a protrusion shape.

4 is a schematic cross-sectional view showing a state before the anisotropic conductive film according to the present invention is pressed between the substrate, Figure 5 is a schematic view showing an electrical connection by pressing the anisotropic conductive film according to the present invention between the substrate. It is a cross section.

As shown in Figs. 4 and 5, the anisotropic conductive adhesive film 3 containing the insulating conductive particles 1 according to the present invention is pressed between the electrodes 41, 51 of the substrates 4, 5, The insulating conductive particles 1 exhibit conductivity in the z-axis direction and insulation in the xy plane direction.

Here, the substrates 4 and 5 are driving integrated circuits or liquid crystal display substrates of the LCD panel, and the electrodes 41 and 51 are bump electrodes or lead patterns of the driving integrated circuits or liquid crystal display substrates.

Fig. 6 is a schematic cross-sectional view showing how the insulating conductive particles according to the present invention are connected to the bump electrode of the circuit board, where (a) shows a state before being electrically connected, and (b) shows a state where they are connected. .

As shown in FIG. 6, when the anisotropic conductive adhesive film is compressed between the substrates, the insulating particles 2 are released from their original positions by breaking or moving, and the surface of the protruding conductive particles 10 on the electrode 41. And the projection 13 penetrates into the oxide film on the surface of the electrode 41 to make an electrical connection, so that the electrical conduction reliability is high. The protruding conductive particles 10 of the present invention are not deformed by heat and pressure.

The present invention will be further illustrated by the following examples, which are merely illustrative of the present invention and are not intended to limit or limit the scope of the present invention.

Example

Example 1

Fabrication of Projected Conductive Particles 10

(1) Preparation of Substrate Particles 11 and Formation of First Metal Layer 12

Spherical substrate particles composed of divinylbenzene resin having a uniform particle size were synthesized by an emulsion polymerization method. At this time, the particle diameter of the polymer resin particles was 4 µm.

The surface of the substrate particles was subjected to nickel plating for 30 minutes at 70 ° C. and pH 6 using an electroless plating method with a composition of 0.5 M of NiSO ₄ , 0.45 M of a complexing agent, and NaH ₂ PO ₂ 1M. The first metal layer produced in the above manner was formed of a nickel plating layer, wherein the film thickness of nickel was 80 nm.

(2) Fabrication of Projective Conductive Particles 10

Protruding particles were prepared to form protrusions on the surface of the nickel plated substrate particles prepared in (1) above. In order to prepare the protruded particles, 50 parts by weight of styrene monomer and 50 parts by weight of divinylbenzene (DVB) are dispersed in ultrapure water containing 1 part by weight of potassium persulfate (KPS), which is a water-soluble initiator, in a reactor at 70 ° C. It superposed | polymerized for 24 hours, and obtained the fine particle of 120 nm in diameter. The prepared poly (St-DVB) particles were freeze-dried for 48 hours after removal of unreacted materials and other impurities using a centrifugal separator to obtain a powder form.

30 g of the poly (St-DVB) particles thus obtained were irradiated with ultrasonic waves to 150 g of 0.2 5% aqueous solution of sodium lauryl sulfate (SLS) for 10 minutes to redispersed in a glass reactor to prepare a dispersion. After the fine particles were completely dispersed, 100 g of ultrapure water was added again, and the temperature was raised to 72.5 ° C. under a nitrogen atmosphere. To this, 50 g of an aqueous solution of 0.35 g of potassium persulfate (KPS), which is a water-soluble initiator, was added, and after 30 minutes, 25 g of styrene (St), divinylbenzene (DVB), and acrylic acid (Acrylic acid) were added. , 4 g, and 4 g of the monomer mixture was slowly dropped over 3 hours to polymerize. After dropping of the monomer, the reaction was further performed for an additional 3 hours, and fine particles of the poly (St-DVB) / poly (St-DVB-AA) core-shell type prepared were unreacted and an emulsifier using a centrifuge. After the removal, the sample was freeze-dried for 48 hours to obtain protruding particles, which were 210 nm in size, in powder form.

The nickel-plated substrate particles and the protuberant particles prepared in (1) above were composited by a hybridization system of Nara Machinery Co., Ltd. The injection ratio at this time was 5 parts by weight of the projection-forming microparticles with respect to the substrate particle 100, and particles having a projection portion discontinuously formed by physical / chemical friction for 15 minutes at a constant stirring speed of 10,000 rpm.

The protrusions thus prepared were subjected to gold plating for 30 minutes at 60 ° C. and pH 5 with the composition of 0.5 M of KAuCN and 0.5 M of complexing agent using an electroless plating method on the surface of the nickel plated substrate particles formed discontinuously. The thickness of the film plated with gold was 40 nm. The final configuration of the protruding conductive fine particles prepared in the above manner consisted of an inner substrate particle, a nickel plating layer, a protrusion, and a gold plated layer on the outermost part.

Preparation of Insulation Particles 2

First, methyl methacrylate (MMA) monomer and divinylbenzene (DVB) were introduced into the reactor, 1.0 g of azobisisobutyronitrile as a fat-soluble initiator, 17.9 g of polyvinylpyrrolidone having a molecular weight of 40,000 as a dispersion stabilizer, and 1: as a solvent. Methanol and 877.7 g of ion-exchanged water mixed in 1 weight ratio were mixed and stirred for complete dissolution. At this time, the total amount of the monomer was adjusted to 100.0 g, but DVB was attached at 30.0% by weight based on the MMA. Subsequently, the polymerization was carried out under a nitrogen atmosphere at a stirring speed of 220 rpm for 24 hours at 70 ° C. The prepared poly (MMA-DVB) particles were removed using a centrifuge to remove unreacted materials and dispersion stabilizers, and then dried in a vacuum oven for 24 hours to obtain hard fine particles having a powder size of 280 nm.

20.0 g of the poly (MMA-DVB) particles thus obtained were irradiated with ultrasonic waves for 10 minutes to 150.0 g of an aqueous 0.25% sodium lauryl sulfate (SLS) solution for 10 minutes to prepare a dispersion. After the fine particles were completely dispersed, 100.0 g of ultrapure water was added again, and the temperature was raised to 72.5 ° C. under a nitrogen atmosphere. 50.0 g of an aqueous solution of 0.2 g of potassium persulfate (KPS), which is a water-soluble initiator, was added thereto, and 30 minutes later, a 20.0 g monomer mixture obtained by mixing 10.0 g of styrene and methyl methacrylate was added in 3 hours. The polymerization was carried out by slowly dropping over. After the dropping of the monomer, the reaction was further performed for an additional 3 hours, and the unreacted material and the emulsifier were removed from the prepared poly (MMA-DVB) / poly (St-MMA) core-shell type fine particles using a centrifuge. After drying for 24 hours in a vacuum oven, 350 nm-sized composite particles were obtained in powder form.

Preparation of the insulating conductive particle 1

The protruding conductive particles 10 and the insulating particles 2 produced by the above method were combined by a hybridization system of Nara Machinery Co., Ltd. At this time, the injection ratio was 90:10, and the insulating conductive fine particles were produced by physical / chemical friction for 12 minutes at a constant stirring speed of 9,000 rpm.

Examples 2 to 3

In Examples 2 and 3, insulating conductive particles were prepared in the same manner as in Example 1 except that the mixing ratio of the protruding conductive particles and the insulating particles was performed as described in Table 1 during the compounding of the insulating particles.

Comparative Examples 1 to 3

In Comparative Examples 1 to 3, the size of the insulating particles was adjusted to 120, 240 and 900 nm by changing the dosage of azobisisobutyronitrile, a fat-soluble initiator, and polyvinylpyrrolidone, a dispersion stabilizer, in preparation of the insulating particles. Insulating conductive particles were prepared in the same manner as in Example 1 except for the ones.

65 parts by weight of NBR rubber, 25 parts by weight of bisphenol A type epoxy resin having an epoxy equivalent of 7000, and a curing agent to prepare an anisotropic conductive film using the insulating conductive particles prepared in Examples 1 to 3 and Comparative Examples 1 to 3 After dissolving 4 parts by weight of 2-methylimidazole in a mixed solvent of toluene and methyl ethyl ketone, the prepared insulating conductive fine particles were dispersed together with the silane coupling agent, and then coated and dried on a release PET film, followed by thickness. An anisotropic conductive film of 25 µm was prepared. The number of electroconductive fine particles contained in the film per unit area was 20,000 piece / mm <2>. The connection resistance of an IC chip was measured as follows using the anisotropically conductive adhesive film manufactured in this way.

The bump electrode height of the evaluation IC chip used was about 40 µm, and the size of the IC chip was 6 mm x mm. The board | substrate which formed the wiring pattern by copper and gold plating of 8 micrometers thick on the board | substrate of 0.8 mm thick BT resin was used. A temperature of 180 ° C. and a pressure of 1.5 MPa in the state in which the anisotropic conductive adhesive film is described between the IC chip and the substrate (in this case, the sum of the bump electrode height and the wiring pattern height is about 58 μm). It pressurized for 10 second on condition of -bump, and crimped | bonded and connected. Subsequently, when the electrical resistance between the upper and lower electrodes of the sample of the electrical connection structure was measured, the electrical resistance between 20 adjacent upper and lower electrodes was measured, and the average value thereof was calculated and represented as the connection resistance.

In addition, an IC chip having a bump electrode size of 15 μm × 70 μm, a bump electrode height of 15 μm, and a pitch of 45 μm and a transparent substrate on which wiring patterns were formed by ITO were connected with an anisotropic conductive adhesive film by the same connection method as described above. Insulation reliability was evaluated by applying a high voltage of 1 kV for 1 minute and the presence or absence of an electrical short was shown in Table 1 below.

To evaluate the solvent resistance of the insulating conductive particles prepared in Examples 1 to 3 and Comparative Examples 1 to 3, a solvent mixture having a viscosity similar to that of the resin composition for producing an anisotropic conductive adhesive film was used. After dissolving a certain amount of insulating conductive particles in a highly viscous solvent mixture in which 40% by weight of NBR rubber is dissolved in a toluene / methylethyl ketone mixed solvent, stirring for 5 hours, only the insulating conductive particles are separately collected and dried, and before solvent treatment. Solvent resistance was evaluated by measuring the particle weight ratio after solvent treatment with respect to particle weight. The solvent resistance evaluation results of the insulating conductive particles thus obtained are shown in Table 1.

As can be seen in the above Examples 1 to 3 and Comparative Examples 1 to 3, the particle size of the insulating particles immobilized on the surface of the insulating conductive particles according to the present invention is larger than the height of the protrusions to realize insulation, and the projection conductive particles By maintaining the particle size of 20% or less of the particle size, it is not easily separated by small impact or pressure, and the insulating conductive particles insulated with the insulating particles whose size of the insulating particles are smaller than the height of the protrusions as in Comparative Examples 1 and 2, As shown in Comparative Example 3, it was found that the size of the insulating particles showed superior insulation reliability and solvent resistance as compared with the insulating conductive particles insulated with the insulating particles having a particle diameter of 20% or more than the particle diameter of the protruding conductive particles. have.

The present invention facilitates the removal of the insulating layer when the electrode is connected to the electrode by producing the projection conductive particles and discontinuously immobilizing the insulating particles on the surface thereof, and furthermore suggests an appropriate size range of the projection conductive particles, thereby providing conductivity in the z-axis direction, Provided are insulating conductive particles excellent in insulation and solvent resistance in the xy plane direction. Moreover, it has the effect of providing the insulating conductive particle suitable for the fine-pitching of a wiring pattern, and the low temperature hardening of an anisotropically conductive adhesive film, an anisotropically conductive adhesive film using insulating conductive particle, and an electrical connection structure.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (11)

Substrate particles 11, the first metal layer 12 plated on the surface of the substrate particles, the projections 13 formed discontinuously on the surface of the first metal layer and the second formed on the surface of the first metal layer formed with the projections Protruding conductive particles 10 made of a metal layer 14; And Insulating particles (2) fixedly discontinuously fixed on the surface of the protruding conductive particles; The diameter of the insulating particles is greater than the height of the protrusion 13 formed on the surface of the first metal layer is in the range of 20% or less of the diameter of the projecting conductive particles 10, When the said insulating particle (2) is connected to an electrode, the protruding conductive particle and an electrode are electrically connected by deviating from an original position, The insulating conductive particle characterized by the above-mentioned. The insulating conductive particle according to claim 1, wherein the first metal layer is made of nickel, and the upper second metal layer is made of gold. The insulating conductive particle according to claim 1, wherein the protruding portion is formed of the protruding particles on the surface of the first metal layer by a mechanical / composite method. The insulating conductive particle according to claim 3, wherein the protruding particles have a core-shell structure composed of a hard core region and a soft shell region. The insulating conductive particle of Claim 1 whose average particle diameter of the said substrate particle (11) is 1-20 micrometers, and connection resistance is 100 GPa or less. The insulating conductive particles according to claim 1, wherein the insulating particles (2) are core-shell polymer polymer particles composed of a hard core region and a soft shell region. The hard core region according to claim 4 or 6, wherein the hard core region is divinylbenzene, 1,4-divinyloxybutane, divinylsulphone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate. , Allyl compounds such as trially trimellitate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerylyl Tritol tri (meth) acrylate, pentaaryl tritol di (de) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol Monomers of acrylic compounds selected from the group consisting of penta (meth) acrylate and glycerol tri (meth) acrylate are crosslinked polymer fine particles radically polymerized, The soft shell region includes unsaturated carboxylic acid, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth), including (meth) acrylic acid, maleic acid, itaconic acid, and the like. Acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, allyl glycidyl ether, 2-isopropenyl 2-oxazoline, diethylaminoethyl (meth) acrylate, alkyl (meth) acrylamide, 4-vinylpyridine, N-methylol acrylamide, dimethylaminopropyl (meth) acrylamide, (meth) acryloyl Characterized in that it is a polymer of a monomer selected from the group consisting of chloride, (meth) acrylonitrile, styrene sulfonic acid, sodium styrene sulfonate and its sulfonic acid derivatives. Is an insulating conductive particle. The anisotropically conductive adhesive film in which the insulating conductive particle in any one of Claims 1-6 is disperse | distributed on a thermosetting resin. The electrical connection structure of Claim 8 is crimped | bonded by the electrode of the board | substrate which opposes. The anisotropically conductive adhesive film in which the insulating conductive particle of Claim 7 is disperse | distributed on a thermosetting resin. An anisotropically conductive adhesive film of claim 10 is pressed between the electrodes of the substrate facing each other, the electrical connection structure.

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