KR20060068601A - Polymer particles, conductive particles and an anisotropic conductive packaging materials containing the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to anisotropic conductive fine particles contained in a structure, an anisotropic conductive connection film, and the like, which electrically connect microelectrodes in a field of mounting a circuit board, and contact each other without affecting an electrode surface when interposed between the connection substrates and compressed. The present invention relates to conductive fine particles having excellent conductivity and polymer resin fine particles used therein by improving the area.

The conductive fine particles of the present invention have an excellent effect of uniform shape, narrow particle size distribution, good deformability during compression, and not easy destruction.

Polymer resin fine particles, conductive fine particles, anisotropic conductive film, K value, compression recovery rate, compression fracture deformation

Description

Polymer Resin Particles, Conductive Particles, and Anisotropic Conductive Material Containing the Same {Polymer Particles, Conductive Particles and An Anisotropic Conductive Packaging Materials Containing the Same}

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the electrical connection of the anisotropically conductive adhesive film using the conductive fine particle of this invention.

Brief description of the main symbols in the drawings

1: conductive particulate 2: circuit board

3: anisotropic conductive adhesive film 4: LCD substrate

11: polymer resin fine particle 12: metal layer

21: bump electrode 31: insulating adhesive resin

41: wiring pattern

The present invention relates to conductive fine particles used for conductive adhesives, anisotropic conductive adhesive films, conductive connection structures, and the like, and to polymer fine particles used for conductive fine particles, and more particularly, when 10% of the particle diameter is deformed. The 10% K value is 250 kgf / mm2 or less, the K value (20% K value and 30% K value) at 20% and 30% compression deformation is 80% or less of the 10% K value, and the compression recovery rate It relates to polymer resin fine particles having a compression fracture strain of 30% or more and 30% or more and conductive fine particles using the same as a substrate.

In general, in order to electrically connect the connection electrode of the IC circuit board and the terminals of the board mounted on the circuit board, such as an LCD (Liquid Crystal Display) panel, anisotropic conductive connection should be made.

As the anisotropic conductive connection material, a film adhesive in which conductive fine particles such as metal coated resin fine particles or metal particles are dispersed in an insulating resin such as epoxy, urethane, or acrylic is widely used. When the manufactured anisotropic conductive connection material is placed between the electrode and the terminal to be connected, and heated and pressed, the electrically conductive fine particles are sandwiched between the electrode and the terminal, so that electric conduction occurs in the pressing direction and perpendicular to the pressing direction. In the direction, the insulating state is maintained by the insulating component of the insulating adhesive.

In LCD packaging requiring such anisotropic conductive connection, with the development of LCD technology, electrical connection reliability is accompanied by the trend of miniaturization of connection pitch, miniaturization of IC bump, and increase in the number of leads printed on a substrate. Improvements are constantly being demanded.

In accordance with these technical requirements, the conductive fine particles contained in the anisotropic conductive film (ACF) have greatly increased the need for uniform particle size and small particle size, and also have a contact area when they are compressed between interposed substrates with moderate compressive deformation and deformation recovery properties. In order to improve the electrical conductivity is also very important that is not easily destroyed. As the conductive fine particles, metal particles such as nickel, gold, and silver and particles coated with a base particle may be used. However, the metal particles have a non-uniform shape and have a specific gravity that is too large compared to the resin when dispersed in an adhesive resin. Therefore, there existed a problem that dispersibility falls.

For this reason, in the field of mounting requiring fine electrode connection and high connection reliability, conductive fine particles having a plating layer formed on a resin fine particle substrate having a uniform shape, a relatively small particle size distribution and excellent conductivity are widely used.

In fact, there have been many studies on the conductive fine particles plated on the resin fine particles, and in particular, considerable research has been made in terms of improving contact reliability with the electrodes and the fine particle characteristics during compression deformation.

PCT Patent Publication No. WO 92/06402 discloses a spacer and conductive fine particles based on monodisperse resin fine particles used as LCD spacers. In order to facilitate gap control, the compressive hardness (10% K value) at 10% compression deformation of the resin fine particles is preferably 250 kgf / mm 2 or more and 700 kgf / mm 2 or less, and the contact area of the conductive fine particles to the electrode after compression is reduced. For widening, it is disclosed that the recovery rate after compression deformation of the resin fine particles is preferably 30% or more and 80% or less.

However, when connecting the electrodes using the conductive fine particles of the spacer substrate, when the load between both electrodes is removed, a slight gap is formed between the conductive fine particles and the electrode surface, which often causes a problem of contact failure. . In addition, as in the 10% K value region, the hard conductive fine particles tend to damage an electrode having relatively low mechanical strength such as an ITO electrode when the electrode is connected.

In addition, Japanese Patent Laid-Open Nos. 11-125953 and 2003-313304 disclose the conductive fine particles having a K value of 250 kgf / mm2 or less and a compression recovery recovery rate of 30% or more at 10% compression deformation to improve connection reliability. Doing. However, in the case of the conductive fine particles having high deformation recovery rate, anisotropic conductive materials having a large increase in the content of the conductive fine particles to several ten percent, such as the connection conditions for fast curing at low temperatures and the connection film for chip on glass (COG) in recent years In the case of a large amount of highly elastic conductive fine particles interposed between the electrodes, the adhesion of the connection film is reduced locally or overall, thereby causing connection problems in the long term.

In addition, Japanese Patent Application Laid-open No. Hei 8-113654 discloses conductive fine particles which do not deform or damage the wiring pattern by non-plastically crushing the conductive fine particles by the pressure applied during normal anisotropic conductive bonding. However, it is difficult to maintain a uniform adhesive layer between the electrodes because the microparticles are non-plastically crushed by the pressure applied at the time of electrode connection, so it is easy to cause uneven adhesion, and also due to excessive deformation and destruction of the substrate microparticles. The conductive layer is likely to be peeled off or detached to lower the conductive performance.

SUMMARY OF THE INVENTION In order to solve the above problems, the object of the present invention is to provide a uniform wiring shape, a narrow particle size distribution, and an appropriate compressive strain and strain recovery property to improve the contact area with the electrode surface, and to provide wiring when interposed between substrates and compressed. It is to provide a polymer resin fine particles and conductive fine particles having excellent conductivity that does not easily break without affecting the pattern.

Another object of the present invention is to provide conductive fine particles having excellent electrical connection reliability and anisotropic conductive connection material using the same.

In order to achieve the above object, the present invention has a 10% K value of 250 kgf / mm 2 or less when 10% of the particle diameter is deformed, the compression recovery rate is 5% or more and 30% or less, and the compression fracture strain is 30% or more The polymer resin microparticles | fine-particles provided are provided.

The polymer resin fine particles are characterized in that the K value at 20% and 30% compression deformation is 80% or less of the 10% K value.

The polymer resin fine particles have an average particle diameter of 0.1 to 200 µm, an aspect ratio of less than 1.5, and a CV value of 20% or less.

The polymer resin fine particles include divinylbenzene, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, allyl (meth ) Allyl compounds, such as acrylate, divinyl sulfone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, trially trimellitate, (poly) ethylene glycol di (meth) acrylate, (Poly) alkylene glycol di (meth) acrylates, such as (poly) propylene glycol di (meth) acrylate, pentaaryl tritol tetra (meth) acrylate, pentaaryl tritol tri (meth) acrylate, Pentaeryltritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethoxypropane tetra (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaeryl tree Tall hexa (meta) arc Rate, characterized by using a reel to the penta tree tolyl-penta (meth) acrylate, glycerol tri (meth) monomer of at least one crosslinking is selected from the group consisting of acrylate.

The polymer resin fine particles include styrene monomers such as styrene, ethyl vinyl benzene, α-methyl styrene, m-chloromethyl styrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n -Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acryl Latex, stearyl (meth) acrylate, ethylene glycol (meth) acrylate, glycidyl (meth) acrylate, vinyl chloride, acrylic ester, acrylonitrile, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl ether , Allyl butyl ether, butadiene, isoprene, characterized in that is prepared by copolymerizing at least one polymerizable unsaturated monomer selected from the group consisting of.

The polymer resin fine particles are produced by the seed polymerization method, characterized in that the molecular weight of the polymer seed particles is 1,000 to 30,000.

In the seed polymerization method, the total content of the polymerizable unsaturated monomer is swelled to 10 to 300 parts by weight based on 1 part by weight of the polymer seed particles.

The present invention also provides conductive fine particles which are based on the polymer resin fine particles and have a metal conductive layer on the surface of the substrate fine particles.

The conductive layer of the conductive fine particles is nickel (Ni), gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), cobalt (Co), tin (Sn), indium (In) ), Indium Tin Oxide (ITO) It is made of at least one metal selected from the group consisting of, the metal conductive layer is characterized in that the thickness of 0.01 to 5 ㎛.

The metal conductive layer of the conductive fine particles is characterized by consisting of at least one double metal layer selected from the group consisting of nickel / gold, nickel / platinum, nickel / silver.

In addition, the present invention provides an anisotropic conductive connecting material comprising a conductive fine particle.

Hereinafter, the content of the present invention will be described in detail.

The conductive fine particles of the present invention are formed of a polymer resin substrate fine particle and at least one metal layer coated on the surface of the substrate fine particle, and the conductive fine particles are structures that electrically connect between the fine electrodes in the field of mounting a circuit board. It is used for an adhesive film and the like.

The polymer resin fine particles used for the conductive fine particles according to the present invention have an appropriate range of K value, compression set recovery rate, and compression fracture in order to exhibit excellent conductivity without deformation or breakage of the wiring pattern when used in the above-mentioned electrical connection material. You have a transformation.

In the present invention, the K value is a value measured using a micro compression tester (MCT-W series manufactured by Shimadzu Corporation, Japan), and fixes a single particle between a smooth upper press indenter having a diameter of 50 μm and a lower press plate, and a compression rate. It is a value calculated by Equation 1 below using the load value and compression displacement obtained by compressing at 0.2275 gf / sec and the maximum test load of 5 gf.

Here, F is the load value (kg) at compression strain x %, S is the compression displacement (mm) at x % compression strain, and R is the radius of the fine particles (mm).

As described above, the polymer resin fine particles of the present invention preferably have a K value at the time of 10% compression deformation of the fine particles in the range of 250 kgf / mm 2 or less. In the case where the fine particles in the above range are used, the electrodes facing each other can be connected without deformation or breakage of the electrode surface by the fine particles. Conductive fine particles with a 10% K value of more than 250 kgf / mm 2 may damage electrodes with relatively weak mechanical properties, such as ITO electrodes.

In general, the 10% K value is a universal or quantitative representation of the hardness of the microparticles, but a simple 10% K value cannot accurately assess the deformation of the microparticles against compression. Therefore, it is more preferable to simultaneously consider the K value in the 20% and 30% compression set.

1 is a cross-sectional view of an electrically connected structure in which conductive fine particles 1 according to the present invention are dispersed in an anisotropic conductive film 3 and interposed between a circuit board 2 and an electrode of a glass substrate 4.

As shown in Fig. 1, in order to stably maximize the contact area with the electrode by deforming the conductive fine particles 1 sufficiently while maintaining the gap between the electrodes uniformly, it is easily deformed according to compression and simultaneously The greater the fracture strain, the better. Therefore, in the present invention, the 20% K value and the 30% K value of the polymer resin fine particles 11 are preferably maintained at a level of 80% or less of the 10% K value, which is a representative value for the initial hardness due to compression. More preferably, it is maintained at a level of 70% or less to impart adequate deformation due to compression.

In addition, the compressive fracture strain of the present invention is also a value obtained by measuring with the same compression tester, and shows the displacement amount Ld at the time point at which the fine particles break, as a ratio Ld / D% to the diameter of the fine particles. In order to sufficiently deform the conductive fine particles 1 during compression to lower the connection resistance, the compressive fracture strain is limited to 30% or more because it must not be easily destroyed by compression. More preferably, the compressive fracture strain should be at least 40%.

In addition, the compression recovery rate of the present invention is obtained by measuring the relationship between the load and the compression displacement at the time of applying and reducing the load by compressing to the peak load 1.0 gf in the microcompression tester and then removing the load up to 0.1 gf at the origin. As a value, the displacement L2 from the peak load to the origin load with respect to the displacement L1 to the peak load under load is expressed as the ratio L2 / L1%. The compression recovery rate was measured at 20 ° C. and the compression rate at load and unload was 0.1517 gf / sec.

Compression recovery rate of the polymer resin microparticles (11) is preferably limited to 5% or more and 30% or less in order to stabilize the adhesion, maximize the contact area with the electrode and improve the connection reliability. This is because when the compression recovery rate of the fine particles is less than 5%, the fine particles have an excessively large elastic difference with the adhesive resin depending on the temperature, so that a gap is likely to be formed on the contact surface with the electrode. In addition, when the compression recovery rate of the fine particles exceeds 30%, as mentioned above, in the low temperature fast curing connection conditions and the high content of the conductive fine particles, the adhesion of the connection film is locally or globally reduced due to the elasticity of the fine particles. Or deterioration of connection reliability in the long term.

It is preferable that it is 0.1-200 micrometers, and, as for the particle diameter of the polymeric resin microparticles | fine-particles 11 of this invention, it is more preferable that it is 1-20 micrometers. This is because when the particle diameter of the fine particles is less than 0.1 μm, agglomeration of the fine particles occurs largely, and the conductive fine particles using the base fine particles having a particle size of more than 200 μm have no benefit for use in recent fine mounting materials.

In addition, the polymer resin fine particles 11 are spherical fine particles, and in order not to reduce connection reliability, the aspect ratio is preferably less than 1.5 and the CV value, which is a variation coefficient of the particle size, is 20% or less. Here, the aspect ratio is the ratio of the longest axis diameter to the shortest axis diameter of the single fine particles, and the CV value is the% value of the standard deviation of the particle diameter divided by the average particle diameter. More preferably, the aspect ratio of the fine particles is less than 1.3 and the CV value is 10% or less.

As described above, the conductive fine particles 1 of the present invention are in a form in which the metal layer 12 is coated on the surface of the polymer resin fine particles 11, and the deformation and recovery to the compression of the conductive fine particles 1 described above. The properties for the properties and the like largely depend on the polymer resin fine particles 11 serving as the substrate.

In the material of the polymer resin-based fine particles 11 as described above, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polytetrafluoroethylene, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyimide, polysulfone, Polyphenylene oxide, polyacetal, urethane resin, unsaturated polyester resin, (meth) acrylate resin, styrene resin, butadiene resin, epoxy resin, phenol resin, melamine resin and the like can be used.

It is preferable to use styrene resin or (meth) acrylate resin among these, and it is especially preferable to use the polymer resin containing a small amount of a crosslinkable monomer. Specific examples of the crosslinkable polymerizable monomer include divinylbenzene, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di (meth) acryl Allyl compounds, such as acrylate, allyl (meth) acrylate, divinyl sulfone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, and trially trimellitate, and (poly) ethylene glycol di (meth) (Poly) alkylene glycol di (meth) acrylates, such as (acrylate), (poly) propylene glycol di (meth) acrylate, and penta erythritol tetra (meth) acrylate, (poly) dimethylsiloxane di (meth) ) Acrylate, (poly) dimethylsiloxane divinyl, (poly) urethane di (meth) acrylate, pentaeryltritol tri (meth) acrylate, pentaeryltritol di (meth) acrylate, trimethylolpropane Tri (meth) acrylate, ditree Methoxypropane tetra (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, inpentaaryl tritol penta (meth) acrylate, glycerol tri ( It is preferable to use one or more selected from the group consisting of meth) acrylate and the like.

Moreover, it is preferable to use the polymerizable unsaturated monomer copolymerizable with the said crosslinkable monomer as a monomer used together with the said crosslinkable polymerizable monomer. Specific examples thereof include styrene monomers such as styrene, ethyl vinyl benzene, α-methyl styrene, and m-chloromethyl styrene, and methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n. -Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acryl Laterate, stearyl (meth) acrylate, (poly) ethylene glycol (meth) acrylate, (poly) propylene glycol (meth) acrylate, (poly) dimethylsiloxane (meth) acrylate, (poly) urethane (meth) Acrylate, glycidyl (meth) acrylate, vinyl chloride, acrylic ester, acrylonitrile, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl ether, allyl butyl ether, butadiene, isoprene and the like.

The manufacturing method of the polymer resin microparticles | fine-particles used in this invention is not specifically limited, For example, suspension polymerization method, dispersion polymerization method, seed polymerization method, seed polymerization method, and emulsion-free polymerization method ( soap-free emulsion polymerization) may be used as appropriate. In particular, in the present invention, a polymer resin fine particle having a uniform particle size distribution was manufactured using a seed polymerization method.

In more detail, the seed polymerization method is described first by adding an aqueous emulsion of a (crosslinked) polymerizable unsaturated monomer in which an oil-soluble initiator is dissolved in an aqueous phase in which polymer seed particles having a uniform particle size are dispersed. After swelling the (crosslinked) polymerizable unsaturated monomer inside the particles, the polymer resin fine particles can be obtained by polymerizing the (crosslinked) polymerizable unsaturated monomer. Since the molecular weight of the said polymer seed particle has a big influence on the phase separation and mechanical property of the polymer resin microparticles | fine-particles finally formed by the seed polymerization method, it is preferable to use it in 1,000-30,000 range, and 3,000-20,000 are more preferable. In addition, the total content of the (crosslinked) polymerizable unsaturated monomer is preferably 10 to 300 parts by weight with respect to 1 part by weight of the polymer seed particles.

Initiators used in the preparation of the polymer resin microparticles are commonly used oil-soluble radical initiators, specifically benzoyl peroxide, lauryl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, t -Butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, 1,1,3-3-tetramethylbutylperoxy-2-ethylhexanoate, dioctanoyl peroxide, didecanoyl Peroxide compounds such as peroxide, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2, It is preferable to use at least one selected from the group consisting of azo compounds such as 4-dimethylvaleronitrile), and generally it is preferably used at 0.1 to 20% by weight based on the monomers.

In the process of polymerizing the polymer resin fine particles, in order to ensure the stability of the latex, a surfactant and a dispersion stabilizer may be used as necessary. The surfactant may be used a general surfactant such as anionic, cationic, nonionic.

In addition, the dispersion stabilizer is a substance that can be dissolved or dispersed in a polymerization medium, gelatin, starch, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylpyrrolidone, polyvinyl alkyl ether, poly Water-soluble polymers such as vinyl alcohol, polyacrylic acid, polyacrylamide, polyethylene oxide, sodium polymethacrylate, and barium sulfate, calcium lactate, calcium carbonate, calcium phosphate, aluminum lactate, talc, clay, diatomaceous earth, metal oxide powder, etc. One or more selected from the group consisting of may be used. The content of the dispersion stabilizer is used in an amount such that the polymer microparticles produced during the polymerization process can suppress the deposition due to gravity or the aggregation between particles, and it is about 0.01 to 15 parts by weight based on 100 parts by weight of the total reactants. desirable.

The conductive fine particles 1 used in the present invention can be obtained by coating the metal layer 12 on the surface of the polymer resin fine particle 11, and are not particularly limited as the metal used for the metal layer 12. For example, nickel (Ni), gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), cobalt (Co), tin (Sn), indium (In), ITO and these Multilayered composite metals and the like. The conductive fine particles 1 of the present invention have a double-layered metal layer 12 in which nickel is plated on the surface of the polymer resin fine particles 11 and then plated with gold. Instead of the gold, platinum (Pt) or silver ( Other conductive metals such as Ag) may be used.

The method of coating the metal layer on the substrate fine particles is not particularly limited, and for example, coating by electroless plating, coating using metal powder, vacuum deposition, ion plating, ion sputtering, or the like can be used.

Preparation of the conductive fine particles by the electroless plating method, specifically after the first step pretreatment process such as degreasing, etching, sensitizing, catalyzing, reducing agent treatment on the surface of the substrate fine particles , The second step of electroless nickel (Ni) plating and washing, and finally three steps of gold (Au) substitution plating.

The electroless plating process will be described in more detail as follows. The polymer resin fine particles are immersed in a surfactant solution of an appropriate concentration to perform surface washing and degreasing treatment. Next, an etching process is performed using a mixed solution of chromic acid and sulfuric acid to form an anchor on the surface of the base material fine particles. Next, when the surface-treated resin substrate fine particles are immersed in tin chloride and palladium chloride solution and subjected to catalysis and activation treatment on the surface, fine nuclei of palladium catalyst are formed on the surface of the substrate fine particles, sodium hypophosphite and hydrogenation. If the reduction reaction is continued with sodium boron, dimethyl amine borane, hydrazine or the like, uniform nuclei of palladium are formed on the resin fine particles. Thus, the fine particles of the palladium nuclei are dispersed in an electroless nickel plating solution, and the nickel salt is reduced with sodium hypophosphite to form a nickel plating layer. Next, when the nickel plated fine particles are added to an electroless gold plating solution at a predetermined concentration to induce a substitution plating reaction of gold, a plating film layer in which gold is deposited is formed on the outermost layer.

In the conductive fine particles 1 of the present invention, the thickness of the conductive metal layer 12 is preferably 0.01 to 5 m. When the thickness of the metal layer is less than 0.01 μm, it is difficult to obtain desired conductivity. On the contrary, when the thickness of the metal layer exceeds 5 μm, the deformation, flexibility, and recovery properties of the fine particles are not properly expressed by the thick metal layer. This is because aggregation of particles easily occurs during use, making it difficult to have excellent conductivity.

The present invention may be better understood by the following examples, which are intended for the purpose of illustrating the invention and are not intended to limit or limit the scope of the invention.

<Example 1>

(1) Synthesis of Seed Particles

30 parts by weight of styrene monomer, 6 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) as an initiator, 18.7 parts by weight of polyvinylpyrrolidone (molecular weight 40,000) as a dispersion stabilizer, methanol 190 as a reaction medium. The solution mixed with 15 parts by weight and 15 parts by weight of ultrapure water was quantitatively added to the reactor, followed by a polymerization reaction at 60 ° C. under a nitrogen atmosphere for 24 hours to prepare seed particles. The prepared polystyrene seed particles were thoroughly washed with ultrapure water and methanol, and then dried in a vacuum lyophilizer to obtain a powder form. The average particle diameter of the prepared seed particles was measured as 1.15 ㎛, CV value 4.2%, molecular weight 14,500.

(2) Synthesis of Polymer Resin-Based Fine Particles

2 parts by weight of the prepared seed particles are uniformly dispersed in 450 parts by weight of 0.2% by weight aqueous solution of sodium lauryl sulfate (SLS). Subsequently, 90 parts by weight of styrene and 10 parts by weight of 1,4-butanediol diacrylate and 10 parts by weight of the mixed monomer dissolved 1.5 parts by weight of a benzoyl peroxide initiator in 300 parts by weight of a 0.2% by weight aqueous solution of SLS were emulsified with a homogenizer for 10 minutes, It was added to swell at room temperature. After confirming that the monomer swelling was completed, 500 parts by weight of a 5% by weight aqueous solution of polyvinyl alcohol having a degree of saponification of 88% was added, and the temperature of the reactor was increased to 80 ° C and polymerized. The crosslinked copolymer resin microparticles prepared from the above were washed several times with ultrapure water and ethanol and then vacuum dried at room temperature. Next, the compressive physical properties of the prepared polymer resin fine particles were measured by a microcompression tester, and the results are shown in Table 1.

(3) Preparation and Evaluation of Conductive Fine Particles

The polymer resin fine particles prepared above are etched in an aqueous solution of chromic acid and sulfuric acid, immersed in a palladium chloride solution, and formed on the surface of a fine nucleus of palladium by electrolytic nickel plating, followed by electroless nickel plating, followed by nickel / gold plating. The conductive fine particles in which the plating layer was formed were obtained.

(4) Fabrication and Evaluation of Anisotropic Conductive Connections

After dissolving 15 parts by weight of epoxy equivalent 6000 bisphenol A epoxy resin and 7 parts by weight of 2-methylimidazole as a curing agent in a mixed solvent of toluene and methyl ethyl ketone, the prepared conductive fine particles were silane in a content of 10% by weight. The film was well dispersed with the coupling agent, coated on a release PET film, and dried to prepare a film having a thickness of 25 μm.

The anisotropic conductive adhesive film thus prepared was subjected to a 0.7 mm thick BT resin substrate having a bump height of 40 μm, an IC chip size of 6 mm × 6 mm, and a copper and gold plating having an 8 μm thick wiring pattern. ), The electrical connection structure was produced by heating, pressing and compressing for 10 seconds at a temperature of 180 ° C. and a pressure of 3 MPa in a state in which the anti-conductive film according to the present invention was described between the IC chip and the substrate.

Subsequently, when measuring the electrical resistance between the upper and lower electrodes of the said connection sample, the electrical resistance between 20 adjacent upper and lower electrodes was measured, the average value was computed, and it represented as connection resistance, and the result is shown in Table 1. In addition, the connection samples were subjected to 85 ° C, 85% RH of relative humidity, resistance rise after 85/85 tests of aging for 1,000 hours, and thermal shock tests after exposure to 500 cold / hot cycles from -40 ° C to 100 ° C. The reliability of the connection was evaluated by the rise value. (Double-circle): Resistance increase 0.1Ω or less, (triangle | delta): Resistance increase value 0.1Ω or more 0.3Ω or less, x: Resistance increase value 0.3Ω or more.

<Example 2>

Synthesis of the polymer resin fine particles, except that 90 parts by weight of styrene and 10 parts by weight of 1,4-butanediol diacrylate was used except that 60 parts by weight of styrene and 40 parts by weight of urethane diacrylate (self-synthesis, molecular weight 1,000) were used. Polymeric resin fine particles and conductive fine particles were obtained in the same manner as in Example 1, and the obtained conductive fine particles and the connection structure using the same were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

<Example 3>

In the synthesis of the polymer resin fine particles, 60 parts by weight of styrene and 40 parts by weight of polydimethylsiloxane diacrylate (self synthesis, molecular weight 950) were used instead of 90 parts by weight of styrene and 10 parts by weight of 1,4-butanediol diacrylate. Polymer resin fine particles and conductive fine particles were obtained in the same manner as in Example 1, and the obtained conductive fine particles and the connection structure using the same were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1

In the synthesis of the polymer resin fine particles, polymer resin fine particles and conductive fine particles were obtained in the same manner as in Example 1 except that 100 parts by weight of divinylbenzene was used instead of 90 parts by weight of styrene and 10 parts by weight of 1,4-butanediol diacrylate. The obtained conductive fine particles and the connection structure using the same were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2

In the synthesis of the polymer resin fine particles, polymer resin fine particles and conductive fine particles were obtained in the same manner as in Example 1 except that 100 parts by weight of styrene was used instead of 90 parts by weight of styrene and 10 parts by weight of 1,4-butanediol diacrylate. The conductive fine particles and the connection structure using the same were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

According to the experimental results of Examples 1 to 3 and Comparative Examples 1 and 2, the conductive fine particles and the anisotropic conductive adhesive film containing the same using the soft substrate fine particles having high compressive strain and high fracture strain according to the present invention have excellent connection resistance and It could be confirmed that the connection reliability was shown.

As described above, the conductive fine particles according to the present invention have a 10% K value of 250 kgf / mm 2 or less when 10% of the particle diameter is deformed, and a K value of 20% and 30% compression deformation (20% K). Value and 30% K value), using the polymer resin fine particles having 80% or less of the 10% K value, compression recovery rate of 5% or more and 30% or less, and compression fracture deformation of 30% or more, as a substrate, suitable compression deformation and recoverability In addition, when interposed between electrodes, such as a circuit board, the contact area is improved without damaging an electrode pattern, and there exists an advantage that the outstanding connection resistance and connection reliability can be exhibited.

Claims (13)

The polymer resin fine particles characterized in that the 10% K value at the time when 10% of the particle diameter is deformed is 250 kgf / mm 2 or less, the compression recovery rate is 5% or more and 30% or less, and the compressive fracture strain is 30% or more. The method of claim 1, The polymer resin fine particles are polymer resin fine particles, characterized in that the K value at 20% and 30% compression deformation is 80% or less of the 10% K value. The method of claim 1, The polymer resin fine particles are polymer resin fine particles, characterized in that the average particle diameter of 0.1 ~ 200㎛. The method of claim 1, The polymer resin fine particles have an aspect ratio of less than 1.5 and a CV value of 20% or less. The method of claim 1, The polymer resin fine particles include divinylbenzene, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, allyl (meth ) Allyl compounds such as acrylate, divinyl sulfone, diallyl phthalate, diallyl acrylamide, triallyl (iso) cyanurate, trially trimellitate, (poly) ethylene glycol di (meth) acrylate, ( (Poly) alkylene glycol di (meth) acrylate, such as poly) propylene glycol di (meth) acrylate, pentaaryl tritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, penta Aryltritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethoxypropane tetra (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaerythritol Hexa (meta) arc Rate, this penta reel tree tolyl-penta (meth) acrylate, glycerol tri (meth) polymer resin characterized by using an acrylate monomer of at least one crosslinking is selected from the group consisting of fine particles. The method of claim 1, The polymer resin fine particles include styrene monomers such as styrene, ethyl vinyl benzene, α-methyl styrene, m-chloromethyl styrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n -Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acryl Laterate, stearyl (meth) acrylate, ethylene glycol (meth) acrylate, glycidyl (meth) acrylate, vinyl chloride, acrylic ester, acrylonitrile, vinyl acetate, vinyl propionate, vinyl butyrate, Polymeric resin fine particles, characterized in that is produced by copolymerizing at least one polymerizable unsaturated monomer selected from the group consisting of vinyl ether, allyl butyl ether, butadiene, isoprene. The method of claim 1, The polymer resin fine particles are produced by a seed polymerization method, the polymer resin particles, characterized in that the molecular weight of the polymer seed particles is 1,000 to 30,000. The method of claim 7, wherein The polymer resin fine particles, wherein the total content of the polymerizable monomer used in the seed polymerization method is swelled to 10 to 300 parts by weight based on 1 part by weight of the polymer seed particles. The fine particles of the polymer resin according to any one of claims 1 to 8 as a substrate, and the conductive fine particles having a metal conductive layer on the surface of the substrate fine particles. The method of claim 9, The conductive layer of the conductive fine particles is nickel (Ni), gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), cobalt (Co), tin (Sn), indium (In) ), Indium tin oxide (Indium Tin Oxide, ITO) conductive fine particles, characterized in consisting of at least one metal selected from the group consisting of. The method of claim 9 or 10, The conductive fine particles of the conductive fine particles, characterized in that made of at least one double metal layer selected from the group consisting of nickel / gold, nickel / platinum, nickel / silver. The method according to claim 9, wherein The conductive fine particles, characterized in that the thickness of the metal conductive layer of the conductive fine particles is 0.01 to 5 ㎛. An anisotropic conductive connection material comprising the conductive fine particles of any one of claims 9 to 12.

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