JP5235305B2 - Protruding conductive fine particles, anisotropic conductive material, and manufacturing method of protruding conductive fine particles - Google Patents

Description

The present invention is crosslinked projections related to a method of producing the firmly adherent collision Okoshishirube conductive particles and anisotropic conductive material, as well as projections conductive fine particles on the surface of the protrusions forming particulate.

  An anisotropic conductive adhesive is a conductive fine particle in which conductive fine particles are monodispersed in a base adhesive resin, sandwiched between electrode terminals and pressed in the thickness direction. Realizes an electrical connection between the terminals. That is, the anisotropic conductive adhesive performs physical connection between the terminal surfaces, and at the same time, electrical connection between corresponding terminals. Anisotropic conductive adhesive is generally supplied in the form of a film or paste, that is, as an anisotropic conductive film (ACF), anisotropic conductive paste (ACP) or anisotropic conductive ink (ACI) or the like. The As the base adhesive, a thermosetting resin such as an epoxy resin is used.

  Anisotropic conductive adhesives are also used in flat display devices such as liquid crystal display devices (LCDs) and plasma display devices (PDPs) and in drive circuit boards, for connecting terminals on display panels and substrates to external connection terminals. Used for mounting an IC chip on a panel surface or a substrate surface. Using anisotropic conductive adhesive, IC chip surface mounting (COG; Chip On Glass) and substrate mounting (COB; Chip On Board, COF; Chip On Flexible board) and semiconductor surface A mounting package or the like is realized. For example, when used for connection between a liquid crystal display panel body and a flexible connection substrate (FPC) or TCP (also called Tape Carrier Package: TAB), the terminal portion of the flexible substrate is made of a tape-like anisotropic conductive adhesive. To the terminal portion around the panel body. At the time of this pasting, precise positioning is performed so that corresponding terminals are connected to each other, and heating and pressure bonding are performed over the entire location where the conductive adhesive is disposed.

  As the conductive fine particles for the anisotropic conductive adhesive, spherical particles made of only metal are also used. However, a resin fine particle coated with a metal layer is widely used for connection between fine terminals. The resin fine particles coated with the metal layer are generally pressure-bonded with a pressure of about 0.015 to 0.02 MPa at a high temperature of 150 ° C. or higher during mounting. Upon receiving this pressure, the fine particles sandwiched between the electrode terminals and pressed in the thickness direction need to be appropriately deformed and always in contact with the terminals in as wide an area as possible. Connection with reduced connection resistance and improved conduction reliability is possible.

In recent years, with aluminum electrodes used in electronic circuits, an oxide film is easily formed on the surface of the electrode, and the oxide film prevents conduction and increases electrical resistance, causing problems such as poor conduction. It was. Even in this case, if conductive particles having conductive protrusions on the surface are used, the protrusions can break through the oxide film on the electrode surface, ensuring conduction and improving the reliability of the circuit. A conductive electroless-plated powder in which is formed has been filed (see, for example, Patent Document 1). Further, a method for obtaining protruding particles and protruding conductive particles by dispersing and colliding the polymerizable droplets of the base particles and the child particles having a smaller diameter than that is applied (for example, see Patent Document 2). .
JP 2000-243132 A JP 2005-171096 A

  According to the examination of the background art by the present inventors, the following facts have been found.

  Since metal protrusions such as nickel are plastically deformed, they cannot be restored once they are crushed and their reliability is low, so they are not suitable for anything other than special applications.

  When the substrate particles are formed from droplets, if the viscosity of the droplets for the substrate particles is low, the child particles are absorbed, and if the viscosity is high, the adhesive force is weak and hardly adheres. The problem was found that it was very difficult to mold into protruding fine particles.

  In view of the above-described situation, the present invention develops a new method for producing protruding fine particles, thereby obtaining protruding fine particles in which crosslinked protrusions are firmly adhered on the surface of the fine particles. An object is to provide an anisotropic conductive material.

The present invention is provided with a projection on its surface with the projections forming particulate, and which has a conductivity for use in manufacturing a liquid crystal display device or a plasma display device, protrusion conductive as a constituent of the anisotropic conductive material a fine, protrusions comprising a crosslinked product of monomer, the are formed on the surface of the protrusions forming particulate, in the medium, the dispersion of the target projection forming particulate, dispersed droplets of the monomer, the collision between the object to be projections formed fine particles and droplets, deposition of the droplets to the target projection forming fine particles, and are formed by polymerization of droplets, projections conductive particles electrically conductive treatment using a metal that has been applied to the surface, The present invention relates to an anisotropic conductive material using the protruding conductive fine particles and a method for manufacturing the protruding fine particles.

  According to the present invention, by superposing the projection droplets on the surface of the projection-forming fine particles, the projection fine particles having the projections firmly adhered on the surface of the fine particles can be obtained, and the subsequent conductive treatment of the projection fine particles. As a result, it is possible to obtain protruding conductive fine particles capable of exhibiting high connection reliability.

  For the purpose of forming a strongly bonded protrusion on the surface of the fine particle, a sufficient function as the protruding fine particle, for example, a different function can be obtained by attaching a polymerizable monomer droplet onto the surface of the protrusion-forming fine particle and polymerizing it. This is achieved without impairing the connection reliability of the protruding conductive fine particles for the isotropic conductive material.

  In the process of producing fine particles in which crosslinked protrusions are firmly bonded, the present invention provides protrusion-forming fine particles (hereinafter referred to as “dispersion medium”, mainly referred to as “dispersion liquid”). `` Dispersion-treated fine particles '' or simply `` treatment fine particles '' are dispersed, and monomer droplets (preferably a polymerization initiator and a crosslinkable monomer are added to the dispersed projection-formed fine particles. In the following, it is also referred to as `` droplet for projection ''), and after the droplet is attached to the projection-formed fine particles, the droplet is polymerized to form projections on the surface of the projection-formed fine particles. By forming, the protrusions derived from the droplets are firmly formed on the surface of the fine particles, and excellent protruding fine particles can be obtained. Protruding conductive fine particles that can be obtained It is based on the look.

  The crosslinkable monomer in the droplets for forming the protrusions is preferably 20% by weight or more of a polyfunctional crosslinking monomer, and the droplets are formed by a seed polymerization method. Desirably, the droplets should have an average diameter in the range of 0.1 μm to 3 μm, and the protrusion has a substantially frustoconical base on the protrusion-forming fine particle side, and the protrusion passes through the base. It is desirable that it is formed on the surface of the projection-forming fine particles.

  The protruding fine particles obtained as described above can be subjected to various conductive treatments, and such fine particles can be used as the protruding conductive fine particles. Preferably, the protruding conductive fine particles constitute an anisotropic conductive material including the same as an essential component.

  The present invention is described in detail below.

  In this dispersion, fine particles for processing are dispersed in a dispersion medium, and the liquid for protrusions of the monomer (containing a crosslinkable monomer, preferably containing a polymerization initiator) is added to the fine particles for processing. After the droplets collide and the protrusion droplets adhere to the surface of the processing fine particles, the crosslinkable monomer of the protrusion droplets is polymerized to form protrusions made of a cross-linked monomer on the surface of the processing fine particles. Form.

(1) (projection-forming fine particles)
As the processing fine particles, ordinary resin fine particles can be used. The method for obtaining the resin fine particles is not particularly limited, and examples thereof include a method by a polymerization method such as emulsion polymerization, suspension polymerization, seed polymerization, dispersion polymerization, soap-free polymerization, and the like.

  The kind of the processing fine particles according to the present invention is not particularly limited as long as it satisfies the desired conditions, and is preferably a resin fine particle, for example, an olefin resin such as polyethylene, polypropylene, polyisobutylene, etc. ; Styrene resins such as polystyrene; Vinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride; Acrylic resins such as polymethyl (meth) acrylate; Conjugated diene resins such as polybutadiene and polyisoprene; Phenol formaldehyde resin, Melamine formaldehyde Resin, condensation resin such as benzoguanamine formaldehyde resin, urea formaldehyde resin; resin fine particles made of polyalkylene terephthalate, polysulfone, polycarbonate, polyamide, etc. are mentioned, among them, any mechanical required as fine particles It is made of a resin obtained by (co) polymerizing one or more polymerizable monomers having an ethylenically unsaturated group because it is easy to obtain resin fine particles having physical properties such as degree of elasticity and elastic recovery rate. Resin fine particles and the like are preferably used. The resin fine particles may be used as a single type, or two or more types may be used in combination. Note that (meth) acrylate means acrylate or methacrylate, and (co) polymerization means homopolymerization or copolymerization, and in some cases also means a system in which both of them coexist.

  When polymerizing a polymerizable monomer having an ethylenically unsaturated group to obtain resin fine particles, resin fine particles can be obtained by copolymerizing a non-crosslinkable monomer and a crosslinkable monomer together. Is preferred. By using a crosslinkable monomer in combination, the gel fraction of the resulting resin fine particles is improved, and the mechanical strength, elastic recovery rate, heat resistance, etc. of the resin fine particles and thus the conductive fine particles are further improved. .

The non-crosslinkable monomer is not particularly limited. For example, styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethyl Styrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, 2,4,5-trimethylstyrene, 2,4,6-trimethylstyrene, p- (n-butyl) styrene, p- (t-butyl) styrene, p- (n-hexyl) styrene, p- (n-octyl) styrene, p- (n-dodecyl) styrene, p-methoxystyrene, p- Styrene monomers such as phenylstyrene, p-chlorostyrene, chloromethylstyrene, 3,4-dichlorostyrene; carboxylic monomers such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride; Methyl (meth) acrylate, ethyl (meth) acrylate, propylene (Meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, etc. Alkyl (meth) acrylate monomers; 2-hydroxylethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate, and other oxygen atom-containing (meth) acrylates Monomers; Unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile; Vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; Vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, etc. No vinyl Ester monomers; Unsaturated hydrocarbon monomers such as ethylene, propylene, isoprene and butadiene; Halogen groups such as vinyl chloride, vinyl fluoride, trifluoromethyl (meth) acrylate and pentafluoroethyl (meth) acrylate Containing monomers and the like. These non-crosslinkable monomers may be used alone or in combination of two or more.

  Further, the crosslinkable monomer is not particularly limited, but examples thereof include polyfunctional vinyl monomers such as divinylbenzene and divinyltoluene; tetramethylene di (meth) acrylate, ethylene glycol di (meth) Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethylene oxide di (meth) acrylate, tetraethylene oxide (meth) acrylate, 1,6-hexane di (meth) acrylate, neopentyl glycol di (meth) acrylate 1,9-nonanediol (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, tetra Multifunctional di (meth) acrylates such as tyrolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol di (meth) acrylate, glycerol tridi (meth) acrylate; vinyltrimethoxysilane, trimethoxysilylstyrene Silane-containing monomers such as γ- (meth) acryloxypropyltrimethoxysilane; allyl group-containing monomers such as triallyl isocyanurate, diallyl phthalate, diallyl acrylamide, diallyl ether, 1,3-butadiene And conjugated diene monomers such as isoprene. These crosslinkable monomers may be used alone or in combination of two or more.

  The amount of the crosslinkable monomer used in combination of the noncrosslinkable monomer and the crosslinkable monomer is not particularly limited, but the crosslinkable monomer is used for 100 parts by weight of the monomer. The content is preferably 5 parts by weight or more, more preferably 20 parts by weight or more, and still more preferably 50 parts by weight or more. If the amount of the crosslinkable monomer used is less than 5 parts by weight, the gel fraction of the resulting resin fine particles will not be sufficiently improved, tending to appear sticky or have a strong thermoplastic property It is in.

  In the production of the above resin fine particles, a polymerization initiator, a polymer protective agent (protective colloid), a dispersion stabilizer, a swelling aid, a chain transfer agent, a viscosity modifier, a colorant (dye or pigment), an extinguishing agent, if necessary. One or more of various additives such as foaming agents may be used.

  The polymerization initiator is not particularly limited. For example, benzoyl peroxide, lauroyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t- Organic peroxides such as butylperoxy 2-ethylhexanoate and di-t-butyl peroxide; azobisisobutyronitrile, azobiscyclohexacarbonitrile, azobis (2,4-dimethylvaleronitrile), etc. And azo compounds. These polymerization initiators may be used alone or in combination of two or more.

  The amount of the polymerization initiator used is not particularly limited, but is preferably 0.1 to 10 parts by weight of the polymerization initiator, more preferably 100 parts by weight of the total amount of the crosslinkable monomers. Is 0.5 to 5 parts by weight. When the amount of the polymerization initiator used is less than 0.1 part by weight based on 100 parts by weight of the total amount of the crosslinkable monomer, the polymerization reaction may not proceed smoothly. When the amount of the polymerization initiator used exceeds 100 parts by weight based on 100 parts by weight, the degree of polymerization (molecular weight) of the resulting resin fine particles becomes too low, and the mechanical strength and heat resistance of the resin fine particles and thus the conductive fine particles are not good. It may be enough.

  In the case of seed polymerization, dispersion polymerization, soap-free polymerization, etc., the fine particles for treatment polymerized as described above have the same particle size, so classification is not necessary, but in emulsion polymerization and suspension polymerization, classification treatment is performed. It is necessary to align the particle diameter. In this case, the deviation coefficient is preferably 20% or less, more preferably 10% or less, and preferably 5% or less.

  The dispersion medium used for forming the processing fine particles is not particularly limited, but water or alcohol is preferable. In the case of alcohol, it is necessary to confirm that the seed droplets do not dissolve if necessary. A surfactant and a protective colloid can be added to the dispersion medium as necessary. As the surfactant, generally used anionic, nonionic or cationic active agents can be appropriately selected and used. As the protective colloid, general water-soluble polymers, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylonitrile and the like can be used.

(2) (Drop for projection)
The droplets that can become protrusions can be made of the same composition as that used for the above-mentioned ordinary resin fine particles. As in the case of ordinary seed droplets for resin fine particles, the amount of the crosslinkable monomer used in combination with the noncrosslinkable monomer and the crosslinkable monomer is not particularly limited, but preferably Is at least 20 parts by weight of the crosslinkable monomer, more preferably, the polyfunctional crosslinkable monomer is at least 20% by weight out of 100% by weight of the crosslinkable monomer. As the amount of the polyfunctional crosslinkable monomer used is larger, a higher strength protrusion tends to be obtained.

  As a method for producing the droplets for protrusions, general seed polymerization, dispersion polymerization, soap-free polymerization, and the like can be used. Before polymerization, the polymer exists on the surface of the medium or processing fine particles and polymerizes. Then, it is necessary to be able to maintain a state where desired protrusions are formed on the surface of the processing fine particles. The medium or the dispersion medium may have the same composition as the medium for forming the processing fine particles described above. Specifically, the following means can be used for forming these droplets.

  That is, the first is based on the emulsion polymerization method in which the surfactant forms droplets using the feature of forming micelles.

  Available surfactants include cationic quaternary ammonium, alkylamine oxide, anionic sulfate, ether sulfate, sulfonate, phosphate ester, sulfosuccinate, etc., nonionic alkylphenol EO (ethylene oxide) Higher alcohol EO, fatty acid ester, amide, polyethylene glycol, polyglycerin ester, EO-PO (ethylene oxide-propylene oxide) block polymer, etc. can be used. The concentration of these surfactants is suitably 0.1 to 20 parts by weight, more preferably 0.5 to 5.0 parts by weight, with respect to 100 parts by weight of the dispersion medium, but it may be appropriately determined depending on the amount of monomer added. I can do it. By this method, it is possible to easily form monodisperse droplets having very uniform diameters in an average diameter range of 0.05 μm to 0.10 μm.

  The second method is based on a soap-free polymerization method in which a water-soluble polymerization initiator forms droplets by utilizing the feature of forming micelles.

  Usable water-soluble polymerization initiators include water-soluble azo polymerization initiators and tertiary amines. The concentration of these polymerization initiators is suitably 0.1 to 20 parts by weight, more preferably 0.5 to 5.0 parts by weight, with respect to 100 parts by weight of the dispersion medium, but it may be appropriately determined depending on the amount of monomer added. I can do it. By this method, it is possible to easily form monodisperse droplets having very uniform diameters in an average diameter range of 0.10 μm to 1.00 μm.

  The third method is based on a dispersion polymerization method in which a water-soluble polymer forms droplets using the feature of forming micelles.

  As these water-soluble polymers, polyvinyl pyrrolidone, polyvinyl alcohol, carboxycellulose, hydroxyethyl cellulose and the like are suitable, and the concentration of the water-soluble polymer can be appropriately determined depending on the amount of the monomer to be added. 0.1 to 20 parts by weight, more preferably 0.5 to 10.0 parts by weight is appropriate for 100 parts by weight. By this method, it is possible to easily form monodisperse droplets having very uniform diameters in an average diameter range of 0.10 μm to 4.0 μm.

  In a droplet forming method using a surfactant and a droplet forming method using a water-soluble polymer, it is necessary to add a polymerization initiator in the monomer.

  Polymerization initiators that can be added include peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, peroxyester compounds, etc., which have radical generating ability. As the azo compound having radical generating ability, diazoaminobenzene, bisazidoformate, bisazoester, bisdioxotriazoline derivative, difluorodiazine and the like can be used.

  In order for the droplets for protrusions formed as described above (corresponding to “seed particles” in the seed polymerization method) to easily absorb the crosslinkable monomer, a swelling aid should be used in the dispersion medium. I can do it.

  The swelling auxiliary agent is not particularly limited as long as it can promote the adsorption or absorption to the droplets (also referred to as seed particles) in the seed polymerization method or the dispersion polymerization method. And alcohols such as isoamyl and the like. These swelling aids may be used alone or in combination of two or more. Further, the monomer can be dispersed by treatment with a homogenizer, ultrasonic waves, etc., and can be easily absorbed into the droplets.

  As the monomer that can be used for the protrusion droplets, as described above, a monomer that can be used for the processing fine particles can be used. However, since the protrusions need to break through the oxide film without difficulty, a certain degree of hardness can be used. is necessary. Accordingly, it is desirable that 20% by weight or more, more preferably 40% by weight or more of 100% by weight of the crosslinkable monomer used in the droplets is a polyfunctional crosslinkable monomer. The size of the droplet that can become a protrusion may be in the average diameter range of 0.1 μm to 3 μm, and preferably 0.2 μm to 1 μm. If it is less than 0.1 μm, it does not easily act as a protrusion, and it is difficult to break through the oxide film. On the contrary, if it exceeds 3 μm, the shape of the particles tends to be distorted, and it becomes difficult to obtain stable conductivity.

(3) (Manufacture of protruding fine particles)
In manufacturing the projection fine particles including the projection-forming fine particles and the projections on the surface, it is possible to use the above-mentioned treatment fine particles, projection droplets, dispersion medium, various additives, collision means such as ultrasonic waves, and the like. I can do it. Specifically, the method for producing projection fine particles includes: (a) a step of dispersing projection-formed fine particles in a medium; (b) a step of dispersing monomer droplets; and (c) projection-formed fine particles and droplets. (D) a step of attaching the projection forming fine particles and the droplet, and (e) a step of polymerizing the droplet.

  The dispersion and collision of the processing fine particles and the protrusion droplets can be performed by mixing the dispersion of the processing fine particles in a dispersion medium with the dispersion of the protrusion droplets in a dispersion medium. The former (fine particles for treatment) can be added to the dispersion of the latter (droplets for protrusions), and conversely, the latter can be added to the former dispersion. The dispersion medium is not particularly limited, and a dispersion medium used for the production of processing fine particles, the production of droplets for protrusions, or the like can be used as it is or newly prepared.

  The mixture is agitated and the like so that the processing fine particles and the projection droplets collide with each other, and the droplets adhere to the processing fine particles to form projections before crosslinking. The means for collision is not particularly limited, but is a general one that is easily available for processing by stirring, homogenizer, ultrasonic waves, or the like. The nature of adhesion, strength, and shape of the protrusion can be arbitrarily selected depending on the viscosity of the droplet, the compatibility between the droplet and the processing fine particles, the size of the crosslinkable monomer, and the like.

  The adhesion of the droplets and the number and shape of the protrusions can be determined while observing under a microscope. At this time, when the droplets are in a preferable state, they are heated to polymerize the crosslinkable monomer. Thus, fine projection particles can be obtained. A substantially frustoconical base can be formed on the projection-forming fine particle side of the droplet, and the projection can be formed on the surface of the projection-forming fine particle via the base of the droplet.

  Droplets that did not collide and unnecessary crosslinked particles derived from the droplets need to be removed appropriately. As a removal method, a method in which only the protruding fine particles are settled and the unnecessary cross-linked particles floating are washed away, a method of removing unnecessary cross-linked particles by classification, a method of removing unnecessary cross-linked particles by sieving or filtration, etc. I can do it.

  In order to make the resulting projection fine particles into bump conductive fine particles, it is necessary to conduct a conductive treatment. As the conductive material, metals such as Ni, Cu, Au, Ag, Pd, and In can be used. The method for forming the conductive layer on the surface of the protruding resin fine particles is not particularly limited, and may be performed by a known method such as electroless plating, vapor deposition, sputtering, ion plating, physical dry or wet coating, etc. I can do it.

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

(Example 1)
(Manufacture of protrusion-forming fine particles)
First, 20 parts by weight of 1,6-hexanediol as a monomer, 1 part by weight of n-lauryl acrylate and 0.2 part by weight of benzoyl peroxide as a polymerization initiator are mixed in a beaker, and uniformly mixed to prepare a monomer solution. . Separately, in a separable flask reactor, 20 parts by weight of a 5% aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was added, and the monomer solution was added to this and stirred well, followed by ion-exchanged water. 120 parts by weight are added. Next, while stirring this solution, the reaction is carried out at 80 ° C. for 18 hours under a nitrogen stream. The obtained fine particles are washed with hot water and then subjected to a water classification operation to obtain resin particles having an average particle diameter of 3.8 μm and a Cv value of 4.8%.

(Manufacture of protruding fine particles and protruding conductive particles)
Into a 300 ml separable flask, 30 parts by weight of projection processing fine particles, 80 parts by weight of ethanol, 30 parts by weight of deionized water, 3.6 parts by weight of PVP (K-30 manufactured by Wako Pure Chemical Industries, Ltd.) A dispersion of fine particles for treatment of protrusions is prepared by ultrasonic dispersion. Next, into 50 ml beaker, 0.6 parts by weight of neopentylglycol dimethacrylate, 2.4 parts by weight of styrene, and 0.03 g of azobisisobutyronitrile as an initiator are mixed and mixed uniformly to obtain a crosslinkable monomer solution. Is made. After the crosslinkable monomer solution is uniformly mixed into the dispersion of the fine particles for treatment of protrusions, the dispersion fine particles are obtained by carrying out dispersion polymerization at 70 ° C. for 18 hours in a nitrogen atmosphere while stirring the solution. Protruding microparticles are produced by impact, adhesion and polymerization of droplets having an average diameter of 0.5 μm. In order to separate unnecessary fine particles, classification is performed, and only unnecessary fine particles are removed to obtain only protruding fine particles. Next, the fine particles are subjected to electroless plating with a nickel layer of 0.16 μm and a gold layer of 0.02 μm to obtain protruding conductive fine particles. The average diameter of the droplets is measured using a dynamic light scattering particle distribution measuring device LB-500 manufactured by Horiba.

(Preparation of anisotropic conductive film)
Epoxy resin JER828 (manufactured by Japan Epoxy Resin Co., Ltd.) 30 parts by weight, epoxy resin JER1256 (manufactured by Japan Epoxy Resin Co., Ltd.) 30 parts by weight, curing agent Novacure HX3721 (manufactured by Asahi Kasei Chemicals Corporation) 60 parts by weight (but solid) 5 parts by weight of the protruding conductive fine particles are dispersed in a sufficiently dissolved amount of 67 wt%) to prepare an insulating adhesive. This insulating adhesive is applied and dried on a release film so that the thickness after drying becomes 30 μm, and an anisotropic conductive film is obtained.

(Continuity test)
After attaching an anisotropic conductive film to the 50 μm pitch aluminum wiring pattern provided on the polyimide substrate and peeling off the release film, align the glass substrate having the same aluminum electrode so that the electrodes overlap each other, to paste together. A portion of the anisotropic conductive film is thermocompression bonded at 10 N and 170 ° C. for 20 seconds, and then the resistance value between the upper and lower electrodes and the presence or absence of leakage between adjacent electrodes are measured. The resistance value between the electrodes is 3 ohms, no leakage between the electrodes is observed, and good results are obtained.

(Example 2)
In the same manner as in Example 1, resin fine particles having an average particle diameter of 4.2 μm and a Cv value of 3.5% were prepared, and protrusion fine particles were prepared from dispersion, collision, adhesion and polymerization of droplets having an average diameter of 0.1 μm, and thereafter By conducting the conductive treatment, protruding conductive fine particles having a nickel thickness of 0.3 μm and a gold thickness of 0.05 μm are obtained. However, the conductive layer is not formed by electroless plating, but is produced using a dry surface treatment apparatus Nobilta NOB-130 (manufactured by Hosokawa Micron Corporation). An anisotropic conductive film is prepared at the same ratio as in Example 1, and the conductivity and leakage current are measured by the same method. The resistance value between the electrodes is 5 ohms, no leakage between the electrodes is observed, and good results are obtained as in Example 1.

(Comparative Example 1)
The same fine particles for treatment of protrusions as in Example 1 are used, but an anisotropic conductive film is prepared by the same formulation without performing only the step of forming protrusions. Conductivity and leakage current are measured in the same manner as in Example 1. There is no leakage between the electrodes, but the resistance between the electrodes is as high as 96 ohms, and good conductivity is not recognized.

  Protrusion fine particles in which the protrusions are firmly formed on the surface of the fine particles by polymerization of the droplets exhibit sufficient functions as protrusion conductive fine particles that can exhibit high connection reliability by conducting a conductive treatment, etc. Useful for anisotropic conductive adhesives and the like.

Claims (7)

Provided with an object projection formation particulates and projections on the surface, and which has a conductivity, a protrusion conductive fine particles of the components of the anisotropic conductive material used for manufacturing liquid crystal display device or plasma display device ,
Projection comprising a crosslinked product of monomer, the are formed on the surface of the protrusions forming particulate, in the medium, the dispersion of the target projection forming particulate, dispersed droplets of the monomer, the target projection forming particulate and collision with the droplets, deposition of the droplets to the target projection forming fine particles, and are formed by polymerization of droplets,
Conductive treatment using a metal characterized that you have been subjected to a surface, the projection conducting particles. 2. The bump conductive fine particle according to claim 1, wherein the droplet contains 20% by weight or more of a polyfunctional crosslinkable monomer in the crosslinkable monomer. The protruding conductive fine particles according to claim 1 or 2, wherein the droplets have an average diameter in the range of 0.1 µm to 3 µm. 2. An anisotropic conductive material comprising projecting conductive fine particles, wherein the projecting conductive fine particles according to claim 1 are used. Provided with an object projection forming particulate and projections on its surface, and which has a conductivity, in obtaining the projection conductive fine particles of the components of the anisotropic conductive material used for manufacturing the liquid crystal display device or plasma display device ,
(a) a step of dispersing the projection-forming fine particles in the medium,
(b) a step of dispersing monomer droplets;
(c) a step of colliding the projection-forming fine particles with the droplets,
(d) a step of attaching the projection-forming fine particles and the droplets ;
(e) a step of polymerizing the droplets ; and
(f) A method for producing protruding conductive fine particles, comprising a step of conducting a conductive treatment using metal on the surface . 6. The method according to claim 5 , wherein a base having a substantially frustoconical shape is formed on the protrusion forming fine particle side of the droplet, and the protrusion is formed on the surface of the protrusion forming fine particle via the base. The method according to claim 5 or 6 , wherein the droplet is formed by a seed polymerization method.