JP6333610B2 - Conductive particle, method for producing conductive particle, conductive material, and connection structure - Google Patents

Description

  The present invention relates to conductive particles used by being dispersed in a binder resin, and a method for producing conductive particles. The present invention also relates to a conductive material and a connection structure using the conductive particles.

  Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin.

  The anisotropic conductive material is used for connection between an IC chip and a flexible printed circuit board, connection between an IC chip and a circuit board having an ITO electrode, and the like. For example, after disposing an anisotropic conductive material between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be electrically connected by heating and pressing.

  As an example of the conductive particles, the following Patent Document 1 discloses a conductive material in which a nickel conductive layer or a nickel alloy conductive layer is formed on the surface of spherical base particles having an average particle diameter of 1 to 20 μm by an electroless plating method. Sex particles are disclosed. The conductive particles have minute protrusions of 0.05 to 4 μm on the outermost layer of the conductive layer. The conductive layer and the protrusion are substantially continuously connected.

  In addition, Patent Document 2 below discloses conductive particles in which a nickel layer is formed on the surface of base material particles. Patent Document 2 describes conductive particles in which a compound having an alkyl group having 6 to 22 carbon atoms is bonded to the surface of a nickel layer.

  Patent Document 2 below discloses conductive particles in which a metal layer containing nickel and a conductive layer containing gold or palladium are sequentially laminated on the surface of a base particle. The conductive layer has a thickness of 10 nm or less, and the conductive layer has an alkyl group having 6 to 22 carbon atoms on the surface.

JP 2000-243132 A JP 2010-103080 A

  Conventionally, as described in Patent Document 2, in order to make a conductive surface hydrophobic in conductive particles, it has been studied to introduce an alkyl group having 6 to 22 carbon atoms into the surface of the conductive layer. Yes.

  However, in the case where the electrodes of the connection target member are electrically connected using the conductive material in which the conductive particles described in Patent Documents 1 and 2 are dispersed in the binder resin, there are bubbles around the conductive particles. Is likely to remain. If bubbles remain around the conductive particles, the connection resistance between the electrodes increases, and the adhesive force between the cured binder resin and the connection target member decreases.

  The object of the present invention is to prevent bubbles from remaining around the conductive particles when electrically connecting the electrodes of the connection target member using a conductive material in which the conductive particles are dispersed in a binder resin. It is providing the electroconductive particle and the manufacturing method of electroconductive particle which can be suppressed, and providing the electrically-conductive material and connection structure using this electroconductive particle.

  According to a wide aspect of the present invention, conductive particles dispersed and used in a binder resin, having at least a conductive portion on the surface, an epoxy group or (meth) acryloyl on the outer surface of the conductive portion. Conductive particles having organic functional groups that are groups are provided.

  On the specific situation with the electroconductive particle which concerns on this invention, melting | fusing point of the said electroconductive part is 300 degreeC or more, and it has the said organic functional group on the outer surface of the electroconductive part whose melting | fusing point is 300 degreeC or more.

  In another specific aspect of the conductive particle according to the present invention, an epoxy group or a (meth) acryloyl group remains on the outer surface of the conductive part using a compound having an epoxy group or a (meth) acryloyl group. It is obtained by binding the above compound to

  On the other specific situation of the electroconductive particle which concerns on this invention, the molecular weight of the compound which has the said epoxy group or (meth) acryloyl group is 100-300.

  In another specific aspect of the conductive particles according to the present invention, using a first functional compound having a reactive functional group capable of binding to the outer surface of the conductive part and an epoxy group or a (meth) acryloyl group, Obtained by bonding the reactive functional group of the first compound to the outer surface of the conductive part, or after introducing the first reactive functional group to the outer surface of the conductive part by surface treatment , Using a second compound having an epoxy group or (meth) acryloyl group and a second reactive functional group capable of reacting with the first reactive functional group, the first reactive functional group and the It is obtained by reacting with a second reactive functional group.

  In another specific aspect of the conductive particle according to the present invention, the compound for introducing an organic functional group which is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part is an epoxy group or (meth). It is a compound having an acryloyl group, and the epoxy equivalent or (meth) acryloyl equivalent of the compound having an epoxy group or (meth) acryloyl group is 100 or more and 300 or less.

  On the other specific situation of the electroconductive particle which concerns on this invention, the said electroconductive part has a processus | protrusion on an outer surface.

  According to a wide aspect of the present invention, there is provided a conductive material including the above-described conductive particles and a binder resin.

  In another specific aspect of the conductive material according to the present invention, the binder resin includes a compound having an epoxy group or a (meth) acryloyl group as a thermosetting compound.

  According to a wide aspect of the present invention, there is provided a method for producing conductive particles dispersed in a binder resin and having a conductive part at least on the surface, using a compound having an epoxy group or a (meth) acryloyl group. An organic functional group which is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part by bonding the compound so that an epoxy group or a (meth) acryloyl group remains on the outer surface of the conductive part. Provided is a method for producing conductive particles, which obtains conductive particles having a group.

  On the specific situation with the manufacturing method of the electroconductive particle which concerns on this invention, the 1st compound which has the reactive functional group which can be couple | bonded with the outer surface of the said electroconductive part, and an epoxy group or a (meth) acryloyl group is used. Then, conductive particles are obtained by bonding the reactive functional group of the first compound to the outer surface of the conductive part, or the first reactive functional group is formed on the outer surface of the conductive part by surface treatment. After introducing the group, the first reaction is carried out using a second compound having an epoxy group or a (meth) acryloyl group and a second reactive functional group capable of reacting with the first reactive functional group. By reacting the functional functional group with the second reactive functional group, conductive particles having an organic functional group which is an epoxy group or a (meth) acryloyl group are obtained on the outer surface of the conductive part.

  According to a wide aspect of the present invention, a first connection target member, a second connection target member, and a connection portion connecting the first connection target member and the second connection target member. A connection structure is provided in which the connection portion is formed of a conductive material containing the conductive particles and the binder resin described above.

  The conductive particles according to the present invention have a conductive part at least on the surface, and have an organic functional group that is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part. When the conductive material in which the particles are dispersed in the binder resin is used to electrically connect the electrodes of the connection target member, it is possible to make it difficult for bubbles to remain around the conductive particles.

  In the method for producing conductive particles according to the present invention, conductive particles having at least a conductive part on the surface and having an organic functional group which is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part are obtained. Therefore, when the obtained conductive particles are electrically connected between the electrodes of the connection target member using a conductive material in which the binder resin is dispersed, it is difficult for bubbles to remain around the conductive particles. Can do.

FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing conductive particles according to the second embodiment of the present invention. FIG. 3 is a cross-sectional view showing conductive particles according to the third embodiment of the present invention. FIG. 4 is a front cross-sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention.

  Details of the present invention will be described below.

  The conductive particles according to the present invention are used by being dispersed in a binder resin. The electroconductive particle which concerns on this invention has an electroconductive part at least on the surface. The electroconductive particle which concerns on this invention has the organic functional group which is an epoxy group or a (meth) acryloyl group on the outer surface of the said electroconductive part.

  The manufacturing method of the electroconductive particle which concerns on this invention is a manufacturing method of the electroconductive particle which is disperse | distributed and used in binder resin and has an electroconductive part at least on the surface. In the method for producing conductive particles according to the present invention, a compound having an epoxy group or a (meth) acryloyl group is used so that the epoxy group or the (meth) acryloyl group remains on the outer surface of the conductive part. By bonding, conductive particles having an organic functional group which is an epoxy group or a (meth) acryloyl group are obtained on the outer surface of the conductive part.

  Since the conductive particles according to the present invention and the method for producing conductive particles according to the present invention have the above-described configuration, the presence of an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part in particular. When the conductive particles are electrically connected between the electrodes of the connection target member using a conductive material in which the conductive particles are dispersed in the binder resin, it is possible to make it difficult for bubbles to remain around the conductive particles. . For example, even when the volatile components in the binder resin are volatilized during the thermosetting of the binder resin, it is possible to make it difficult for bubbles to remain around the conductive particles in the obtained connection structure.

  As a result of suppressing the remaining of bubbles around the conductive particles, the connection resistance between the electrodes is lowered, and the adhesive force between the cured binder resin and the connection target member is increased.

  The conductive particles having at least a conductive part on the surface may be conductive particles having base particles and conductive parts arranged on the surface of the base particles, and the whole is a conductive part. May be a conductive particle (such as a metal particle). The conductive part is preferably a conductive layer. Above all, from the viewpoint of reducing the cost, increasing the flexibility of the conductive particles, and further increasing the conduction reliability between the electrodes, the base particles and the surface of the base particles The electroconductive particle which has the electroconductive part arrange | positioned is preferable.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, the electroconductive particle which concerns on the 1st Embodiment of this invention is shown with sectional drawing.

  A conductive particle 1 shown in FIG. 1 includes a base particle 2, a conductive layer 3, and a plurality of core substances 4. The conductive particle 1 is a particle having a base particle 2 and a conductive layer 3 disposed on the surface of the base particle 2. The conductive layer 3 is a conductive part. The conductive particles 1 have an organic functional group that is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive layer 3.

  The conductive layer 3 is disposed on the surface of the base particle 2. The conductive layer 3 covers the surface of the base particle 2. The conductive particle 1 is a coated particle in which the surface of the base particle 2 is coated with the conductive layer 3.

  The conductive particle 1 has a plurality of protrusions 1a on a conductive surface. The conductive layer 3 has a plurality of protrusions 3a on the outer surface. A plurality of core substances 4 are arranged on the surface of the base particle 2. A plurality of core materials 4 are embedded in the conductive layer 3. The core substance 4 is disposed inside the protrusions 1a and 3a. The conductive layer 3 covers a plurality of core materials 4. The outer surface of the conductive layer 3 is raised by the plurality of core materials 4 to form protrusions 1a and 3a.

  In FIG. 2, the electroconductive particle which concerns on the 2nd Embodiment of this invention is shown with sectional drawing.

  A conductive particle 11 shown in FIG. 2 includes a base particle 2 and a conductive layer 12. The conductive particle 11 is a particle having the base particle 2 and the conductive layer 12 disposed on the surface of the base particle 2. The conductive layer 12 is a conductive part. The conductive particles 11 have an organic functional group that is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive layer 12. The conductive particles 1 and the conductive particles 11 differ only in the presence or absence of a core substance.

  The conductive particles 11 do not have a core substance. The conductive layer 12 has a first portion and a second portion that is thicker than the first portion. The conductive particles 11 have a plurality of protrusions 11a on the conductive surface. A portion excluding the plurality of protrusions 11 a is the first portion of the conductive layer 12. The plurality of protrusions 11a are located in the second portion where the conductive layer 12 is thick. The conductive layer 12 has a plurality of protrusions 12a on the outer surface. As described above, the conductive particles according to the present invention may use a core substance to form protrusions on the outer surface of the conductive part, but may not use a core substance.

  In FIG. 3, the electroconductive particle which concerns on the 3rd Embodiment of this invention is shown with sectional drawing.

  A conductive particle 21 shown in FIG. 3 includes a base particle 2 and a conductive layer 22. The conductive particles 21 are particles having the base particle 2 and the conductive layer 22 disposed on the surface of the base particle 2. The conductive layer 22 is a conductive part. The conductive particles 21 have an organic functional group that is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive layer 22.

  The conductive particles 21 shown in FIG. 3 do not have a core substance. The outer surface of the conductive layer 22 is spherical. The conductive layer 22 has no protrusion on the surface. Thus, the electroconductive particle which concerns on this invention does not need to have a processus | protrusion, and may be spherical.

  In addition, it is preferable that the said electroconductive particle is not arrange | positioning the insulating particle on the surface of the said electroconductive part, and it is preferable that the insulating layer is not arrange | positioned.

  Hereinafter, the conductive particles will be described in more detail.

(Conductive particles)
The said electroconductive particle has an organic functional group which is an epoxy group or a (meth) acryloyl group on the outer surface of the said electroconductive part. The conductive particles may have only one or both of an epoxy group and a (meth) acryloyl group as the organic group on the outer surface of the conductive part. . The conductive particles preferably have an epoxy group on the outer surface of the conductive part, and preferably have a (meth) acryloyl group. The (meth) acryloyl group represents an acryloyl group and a methacryloyl group.

  From the viewpoint of more easily obtaining conductive particles capable of suppressing the remaining of bubbles, the conductive particles are formed on the outer surface of the conductive portion using a compound having an epoxy group or a (meth) acryloyl group. It is preferably obtained by bonding the above compound so that an epoxy group or a (meth) acryloyl group remains.

  The compound having an epoxy group or a (meth) acryloyl group may be a compound having an epoxy group, a compound having a (meth) acryloyl group, and having an epoxy group and a (meth) acryloyl group. It may be a compound.

  Specific examples of the compound having an epoxy group or a (meth) acryloyl group used for introducing an epoxy group onto the outer surface of the conductive part include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, Examples include 3- (meth) acryloxypropyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane.

  From the viewpoint of more easily obtaining conductive particles capable of suppressing the remaining of bubbles, the conductive particles include a reactive functional group capable of binding to the outer surface of the conductive portion, an epoxy group, or (meth). It is obtained by bonding the reactive functional group of the first compound to the outer surface of the conductive part using the first compound having an acryloyl group, or the outer surface of the conductive part is the surface A second compound having an epoxy group or a (meth) acryloyl group and a second reactive functional group capable of reacting with the first reactive functional group after treatment to introduce the first reactive functional group Is preferably obtained by reacting the first reactive functional group with the second reactive functional group. The conductive particles are preferably obtained using the first compound, and are preferably obtained using the second compound.

  From the viewpoint of more easily obtaining conductive particles capable of suppressing the remaining of bubbles, in the method for producing conductive particles, the reactive functional group of the first compound is formed on the outer surface of the conductive part. After the conductive particles are obtained by bonding or the first reactive functional group is introduced to the outer surface of the conductive part by surface treatment, the first reactivity is obtained using the second compound. It is preferable to obtain conductive particles having an organic functional group that is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part by reacting the functional group with the second reactive functional group. .

  Specific examples of the first compound include 2- (methacryloyloxy) ethyl phosphate and 10- (methacryloyloxy) decyl phosphate.

  Specific examples of the second compound include 4-hydroxybutyl acrylate glycidyl ether and glycidyl methacrylate.

  The said electroconductive particle is obtained by processing using the compound which introduce | transduces the said organic functional group. From the viewpoint of obtaining the effects of the present invention more effectively, the molecular weight of the compound into which the organic functional group is introduced is preferably 100 or more, more preferably 150 or more, still more preferably 200 or more, preferably 300 or less, more preferably. Is 280 or less, more preferably 250 or less.

  The molecular weight of the compound having an epoxy group or (meth) acryloyl group, the first compound and the second compound is preferably 100 or more, more preferably 150 or more, still more preferably 200 or more, preferably 300 or less. More preferably, it is 280 or less, More preferably, it is 250 or less.

  The molecular weight means a molecular weight that can be calculated from the structural formula when the compound is not a polymer and when the structural formula of the compound can be specified. Moreover, when the said compound is a polymer, a weight average molecular weight is meant. The said weight average molecular weight shows the weight average molecular weight in polystyrene conversion calculated | required by a gel permeation chromatography (GPC) measurement.

  From the viewpoint of obtaining the effect of the present invention more effectively, when the compound into which the organic functional group is introduced is a compound having an epoxy group, the epoxy equivalent of the compound having an epoxy group is preferably 100 or more, more Preferably it is 120 or more, preferably 300 or less, more preferably 280 or less.

  From the viewpoint of more effectively obtaining the effects of the present invention, when the compound into which the organic functional group is introduced is a (meth) acryloyl group, the (meth) acryloyl group equivalent of the compound having a (meth) acryloyl group is Preferably it is 100 or more, More preferably, it is 120 or more, Preferably it is 300 or less, More preferably, it is 280 or less.

  The epoxy equivalent or (meth) acryloyl equivalent of the compound having the epoxy group or (meth) acryloyl group, the first compound and the second compound is preferably 100 or more, more preferably 120 or more, still more preferably. 150 or more, preferably 300 or less, more preferably 280 or less, and further preferably 250 or less. Moreover, each epoxy equivalent or (meth) acryloyl equivalent is calculated | required by potentiometric titration (Potentiometric Titration).

[Base material particles]
Examples of the substrate particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The base particles may be core-shell particles. The substrate particles are preferably substrate particles excluding metal particles, more preferably resin particles, inorganic particles excluding metals, or organic-inorganic hybrid particles, and even more preferably resin particles or organic-inorganic hybrid particles.

  The substrate particles are preferably resin particles formed of a resin. When connecting between electrodes using the said electroconductive particle, after arrange | positioning the said electroconductive particle between electrodes, the said electroconductive particle is compressed by crimping | bonding. When the substrate particles are resin particles, the conductive particles are easily deformed during the pressure bonding, and the contact area between the conductive particles and the electrode is increased. For this reason, the conduction | electrical_connection reliability between electrodes becomes high.

  Various organic materials are suitably used as the resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Alkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene Oxide, polyacetal, polyimide, polyamideimide, polyether ether Tons, polyethersulfone, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. Since the hardness of the substrate particles can be easily controlled within a suitable range, the resin for forming the resin particles is obtained by polymerizing one or more polymerizable monomers having a plurality of ethylenically unsaturated groups. A polymer is preferred.

  When the resin particles are obtained by polymerizing a monomer having an ethylenically unsaturated group, the monomer having the ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer. And a polymer.

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylates such as meth) acrylate and isobornyl (meth) acrylate; oxygen such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate (Meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; vinyl acids such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate Esters; Unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; Halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride and chlorostyrene Is mentioned.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipenta Erythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylates such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanure And silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane It is done.

  The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of polymerizing by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  In the case where the substrate particles are inorganic particles or organic-inorganic hybrid particles excluding metal, examples of the inorganic material for forming the substrate particles include silica and carbon black. The particles formed from the silica are not particularly limited. For example, after forming a crosslinked polymer particle by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, firing may be performed as necessary. The particle | grains obtained by performing are mentioned. Examples of the organic / inorganic hybrid particles include organic / inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

  When the substrate particles are metal particles, examples of the metal for forming the metal particles include silver, copper, nickel, silicon, gold, and titanium. However, the substrate particles are preferably not metal particles.

[Conductive part]
The metal for forming the conductive part is not particularly limited. The metal for forming the metal particles is not particularly limited when at least the entire surface of the conductive particles whose surface is the conductive part is the metal particles which are the conductive part. Examples of the metal include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, and tungsten. , Molybdenum, and alloys thereof. Examples of the metal include tin-doped indium oxide (ITO) and solder. Especially, since the connection resistance between electrodes can be made still lower, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is preferable. The melting point of the conductive part is preferably 300 ° C. or higher, more preferably 450 ° C. or higher. The conductive part is preferably not solder. The melting point of solder is generally less than 300 ° C. The conductive part preferably has the organic functional group on the outer surface of the conductive part having a melting point of 300 ° C. or higher and a melting point of 300 ° C. or higher. When the conductive part does not melt when obtaining the connection structure, bubbles tend to remain around the conductive particles. However, the use of the conductive particles according to the present invention effectively prevents the bubbles from remaining. Can be suppressed. Therefore, when the conductive part does not melt when obtaining the connection structure, the effect of the present invention is remarkably obtained. The conductive part may contain nickel or copper.

  The conductive layer may be formed of one layer or may be formed of a plurality of layers. That is, the conductive layer may have a stacked structure of two or more layers. When the conductive layer is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, or a copper layer, and more preferably a gold layer. When the outermost layer is these preferred conductive layers, the connection resistance between the electrodes is further reduced. Moreover, when the outermost layer is a gold layer, the corrosion resistance is further enhanced.

  The method for forming the conductive portion on the surface of the substrate particles is not particularly limited. As a method for forming the conductive portion, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating the surface of base particles with metal powder or a paste containing metal powder and a binder Etc. Especially, since formation of an electroconductive part is simple, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

  The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 100 μm or less, more preferably 20 μm or less. When the particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, the contact area between the conductive particles and the electrode becomes sufficiently large when the electrodes are connected using the conductive particles, and the conductive part When forming the conductive particles, it becomes difficult to form aggregated conductive particles. Further, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion is difficult to peel from the surface of the base particle.

  The particle diameter of the conductive particles indicates the diameter when the conductive particles are true spherical, and indicates the maximum diameter when the conductive particles are not true spherical.

  The thickness of the conductive layer is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, more preferably 0.3 μm or less. When the thickness of the conductive layer is not less than the above lower limit and not more than the above upper limit, the conductivity is sufficiently high and the conductive particles are not too hard, and the conductive particles can be sufficiently deformed when connecting the electrodes. It is.

  When the conductive layer is formed of a plurality of layers, the thickness of the outermost conductive layer is preferably 0.001 μm or more, more preferably the thickness of the gold layer when the outermost layer is a gold layer. It is 0.01 μm or more, preferably 0.5 μm or less, more preferably 0.1 μm or less. When the thickness of the outermost conductive layer is not less than the lower limit and not more than the upper limit, the outermost conductive layer can be uniformly coated, the corrosion resistance is sufficiently high, and the connection resistance between the electrodes is sufficiently high. Lower. Further, the thinner the gold layer when the outermost layer is a gold layer, the lower the cost.

  The thickness of the conductive layer can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (TEM).

[Core material]
The conductive particles preferably have protrusions on the conductive surface, preferably have protrusions on the outer surface of the conductive portion, and the protrusions are preferably plural. An oxide film is often formed on the surface of the electrode connected by the conductive particles. When conductive particles having protrusions on the outer surface of the conductive portion are used, the oxide film can be effectively eliminated by the protrusions by disposing the conductive particles between the electrodes and pressing them. For this reason, an electrode and an electroconductive part contact more reliably and the connection resistance between electrodes becomes still lower. Furthermore, when the electrodes are connected, the insulating material between the conductive particles and the electrodes can be effectively eliminated by the protrusions of the conductive particles. For this reason, the conduction | electrical_connection reliability between electrodes becomes high.

  Since the core substance is embedded in the conductive portion, it is easy for the conductive portion to have a plurality of protrusions on the outer surface. However, in order to form protrusions on the surface of the conductive particles and the outer surface of the conductive part, the core substance is not necessarily used. That is, protrusions may be formed on the surface of the conductive particles and the outer surface of the conductive portion by a method other than the method using the core substance.

  As the method for forming the protrusions, a core material is attached to the surface of the base particle, and then a conductive layer is formed by electroless plating, and a conductive layer is formed on the surface of the base particle by electroless plating. Thereafter, a method of attaching a core substance and further forming a conductive layer by electroless plating may be used. As another method for forming the protrusion, a first conductive layer is formed on the surface of the base particle, and then a core substance is disposed on the first conductive layer, and then the second conductive layer. And a method of adding a core substance in the middle of forming the conductive layer on the surface of the base particle.

  As a method of disposing the core substance on the surface of the base particle, for example, the core substance is added to the dispersion of the base particle, and the core substance is applied to the surface of the base particle, for example, van der Waals force. And a method in which a core substance is added to a container containing base particles, and a core substance is attached to the surface of the base particles by mechanical action such as rotation of the container. . Especially, since the quantity of the core substance to adhere is easy to control, the method of making a core substance accumulate and adhere on the surface of the base particle in a dispersion liquid is preferable.

  The conductive particles may have a first conductive layer on the surface of the base particle, and may have a second conductive layer on the first conductive layer. In this case, a core substance may be attached to the surface of the first conductive layer. The core material is preferably covered with a second conductive layer. The thickness of the first conductive layer is preferably 0.05 μm or more, and preferably 0.5 μm or less. The conductive particles form a first conductive layer on the surface of the base particle, and then a core material is deposited on the surface of the first conductive layer, and then the first conductive layer and the core material are formed. It is preferably obtained by forming a second conductive layer on the surface.

  Examples of the material constituting the core material include conductive materials and non-conductive materials. Examples of the conductive material include conductive non-metals such as metals, metal oxides, and graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Examples of the nonconductive material include silica, alumina, and zirconia. Among them, metal is preferable because conductivity can be increased and connection resistance can be effectively reduced. The core substance is preferably metal particles.

  Examples of the metal include gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead. Examples include alloys composed of two or more metals such as alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide. Of these, nickel, copper, silver or gold is preferable. The metal constituting the core substance may be the same as or different from the metal constituting the conductive part. The metal constituting the core substance preferably includes a metal constituting the conductive part. It is preferable that the metal which comprises the said core substance contains nickel. It is preferable that the metal which comprises the said core substance contains nickel.

  The shape of the core material is not particularly limited. The shape of the core substance is preferably a lump. Examples of the core substance include a particulate lump, an agglomerate in which a plurality of fine particles are aggregated, and an irregular lump.

  The average diameter (average particle diameter) of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, more preferably 0.2 μm or less. When the average diameter of the core substance is not less than the above lower limit and not more than the upper limit, the connection resistance between the electrodes is effectively reduced.

  The “average diameter (average particle diameter)” of the core substance indicates a number average diameter (number average particle diameter). The average diameter of the core material is obtained by observing 50 arbitrary core materials with an electron microscope or an optical microscope and calculating an average value.

(Conductive material)
The conductive material according to the present invention includes the conductive particles described above and a binder resin. The conductive particles are preferably dispersed in a binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material.

  The binder resin preferably contains a thermosetting component. The binder resin preferably contains a thermosetting compound as the thermosetting component. The binder resin preferably contains a thermosetting compound and a thermosetting agent as the thermosetting component.

  The thermosetting compound is not particularly limited. As the thermosetting compound, for example, an insulating resin is used. As for the said thermosetting compound, only 1 type may be used and may be used together.

  Known examples of the thermosetting compound include epoxy resins, phenoxy resins, polyvinyl formal resins, polystyrene resins, polyvinyl butyral resins, polyester resins, polyamide resins, xylene resins, and polyurethane resins.

  The thermosetting compound preferably has a reactive functional group capable of reacting with an epoxy group or a (meth) acryloyl group. The thermosetting compound is preferably a compound having an epoxy group or a (meth) acryloyl group. When the organic functional group on the outer surface of the conductive part in the conductive particle is an epoxy group, the thermosetting compound is preferably a compound having an epoxy group. When the organic functional group on the outer surface of the conductive part in the conductive particle is a (meth) acryloyl group, the thermosetting compound is preferably a compound having a (meth) acryloyl group.

  In the connection structure obtained by the reaction between the organic functional group in the conductive particle and the reactive functional group capable of reacting with the epoxy group or the (meth) acryloyl group in the thermosetting compound, Air bubbles are less likely to remain around.

  Since the epoxy resin or the (meth) acryloyl group in the conductive particles can be efficiently reacted, the binder resin preferably contains a compound having an epoxy group or an acrylic group as a thermosetting compound.

  The said thermosetting agent is not specifically limited. A conventionally known thermosetting agent can be used as the thermosetting agent. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents, acid anhydrides, thermal cation curing agents, and thermal radical generators. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of curing the conductive material more rapidly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a polythiol curing agent, or an amine curing agent. Further, from the viewpoint of further improving the storage stability of the conductive material, a latent curing agent is preferable. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer material such as polyurethane resin or polyester resin.

  The imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.

  The polythiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

  The amine curing agent is not particularly limited, and hexamethylene diamine, octamethylene diamine, decamethylene diamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5]. Examples include undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.

  As the thermal cation curing agent, iodonium salts and sulfonium salts are preferably used. For example, commercially available products of the above-mentioned thermal cation curing agent include San-Aid SI-45L, SI-60L, SI-80L, SI-100L, SI-110L, SI-150L manufactured by Sanshin Chemical Industry, and ADEKA Adeka optomer SP-150, SP-170 etc. are mentioned.

Preferred anionic moieties of the thermal cationic curing agent include PF ₆ , BF ₄ , and B (C ₆ F ₅ ) ₄ .

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably 30 parts by weight or less, more preferably 20 parts by weight or less with respect to 100 parts by weight of the thermosetting compound. It is. When the content of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the conductive material can be sufficiently thermoset.

  In addition to the conductive particles and the thermosetting component, the conductive material includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a light stabilizer. Various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent or a flame retardant may be contained.

  The method for dispersing the conductive particles in the binder resin is not particularly limited, and a conventionally known dispersion method can be used. Examples of a method for dispersing the conductive particles in the binder resin include a method in which the conductive particles are added to the binder resin and then kneaded and dispersed with a planetary mixer or the like. The conductive particles are dispersed in water. Alternatively, after uniformly dispersing in an organic solvent using a homogenizer or the like, it is added to the binder resin, kneaded and dispersed with a planetary mixer or the like, and the binder resin is diluted with water or an organic solvent. Then, the method of adding the said electroconductive particle, kneading with a planetary mixer etc. and disperse | distributing is mentioned.

  The conductive material can be used as a conductive paste and a conductive film. When the conductive material according to the present invention is a conductive film, a film that does not include conductive particles may be laminated on a conductive film that includes conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

  In 100% by weight of the conductive material, the content of the binder resin is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, preferably 99.% or more. It is 99 weight% or less, More preferably, it is 99.9 weight% or less. The content of the thermosetting component in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, further preferably 50% by weight or more, particularly preferably 70% by weight or more, preferably It is 99.99 weight% or less, More preferably, it is 99.9 weight% or less. When the content of the binder resin and the thermosetting component is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material Becomes even higher.

  In 100% by weight of the conductive material, the content of the conductive particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 40% by weight or less, more preferably 20% by weight or less, More preferably, it is 10 weight% or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further enhanced.

(Connection structure)
A connection structure can be obtained by connecting a connection object member using the electrically-conductive material containing the electroconductive particle and binder resin which concern on this invention.

  The connection structure includes a first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members, the connection portion according to the present invention. A connection structure formed of a conductive material containing conductive particles and a binder resin is preferable.

  In FIG. 4, the connection structure using the electroconductive particle which concerns on the 1st Embodiment of this invention is typically shown with front sectional drawing.

  4 includes a first connection target member 52, a second connection target member 53, and a connection portion 54 that connects the first and second connection target members 52 and 53. Prepare. The connection portion 54 includes the conductive particles 1 and a binder resin (such as a cured binder resin). The connection portion 54 is formed by curing a conductive material including the conductive particles 1. In FIG. 4, the conductive particles 1 are schematically shown for convenience of illustration. Instead of the conductive particles 1, conductive particles 11, 21 and the like may be used.

  The first connecting member 52 has a plurality of first electrodes 52a on the surface (upper surface). The second connection target member 53 has a plurality of second electrodes 53a on the surface (lower surface). The first electrode 52 a and the second electrode 53 a are electrically connected by one or a plurality of conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.

The manufacturing method of the connection structure is not particularly limited. As an example of the manufacturing method of the connection structure, the conductive material is disposed between the first connection target member and the second connection target member to obtain a laminate, and then the laminate is heated and pressurized. Methods and the like. The pressure of the said pressurization is about 9.8 * 10 < ⁴ > -4.9 * 10 < ⁶ > Pa. The temperature of the said heating is about 120-220 degreeC.

  Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors, and diodes, and electronic components that are circuit boards such as printed boards, flexible printed boards, glass epoxy boards, and glass boards. The connection target member is preferably an electronic component. The conductive particles are preferably used for electrical connection of electrodes in an electronic component.

  Examples of the electrode provided on the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, a molybdenum electrode, and a tungsten electrode. When the connection object member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated | stacked on the surface of the metal oxide layer may be sufficient. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, and Ga.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
Divinylbenzene copolymer resin particles having a particle size of 3.0 μm (“Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) were prepared.

  After dispersing 10 parts by weight of the resin particles in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, the resin particles were taken out by filtering the solution. Next, the resin particles were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the resin particles. The resin particles whose surface was activated were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

  Further, a nickel plating solution (pH 8.5) containing 0.23 mol / L of nickel sulfate, 0.92 mol / L of dimethylamine borane and 0.5 mol / L of sodium citrate was prepared.

  While stirring the obtained suspension at 60 ° C., the nickel plating solution was gradually added dropwise to the suspension to perform electroless nickel plating. Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to place a nickel-boron conductive layer (thickness 0.1 μm) on the surface of the resin particles, and the surface is a conductive layer. Particles were obtained.

  10 g of the obtained particles were mixed with 300 mL of an aqueous solution of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane 0.1 mol / L, and ultrasonically dispersed at 50 ° C. for 20 minutes. Thereafter, the dispersion was filtered to obtain conductive particles having an epoxy group on the outer surface of the conductive layer.

(Example 2)
Conductive particles having an acryloyl group on the outer surface of the conductive layer in the same manner as in Example 1 except that 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was changed to 3-acryloxypropyltrimethoxysilane. Got.

(Example 3)
Conductive particles having a methacryloyl group on the outer surface of the conductive layer in the same manner as in Example 1 except that 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was changed to 3-methacryloxypropyltrimethoxysilane. Got.

Example 4
Conductivity having an epoxy group on the outer surface of the conductive layer in the same manner as in Example 1 except that 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was changed to 3-glycidoxypropylmethyldimethoxysilane. Particles were obtained.

(Example 5)
Conductive particles having an epoxy group on the outer surface of the conductive layer were obtained in the same manner as in Example 1 except that dimethylamine borane was changed to sodium hypophosphite.

(Example 6)
Example 1 except that the nickel plating solution was changed to a copper plating solution (pH 11.0) containing 0.30 mol / L of copper sulfate, 3.55 mol / L of formaldehyde, and 0.43 mol / L of ethylenediaminetetraacetic acid. In the same manner as above, conductive particles having an epoxy group on the outer surface of the conductive layer (copper layer, thickness 0.1 μm) were obtained.

(Example 7)
Using metallic nickel particle slurry (“2020SUS” manufactured by Mitsui Kinzoku Co., Ltd., average particle size 200 nm), after the metallic nickel particles are adhered to the surface of the resin particles, a conductive layer is formed on the outer surface of the conductive part. Conductive particles having an epoxy group on the outer surface of the conductive layer were obtained in the same manner as in Example 1 except that the protrusions were formed.

(Example 8)
Conductive particles in which the surface of the resin particles used in Example 1 was coated with a nickel-boron conductive layer (thickness: 0.1 μm) were prepared. A suspension was obtained by adding 10 parts by weight of the conductive particles to 500 parts by weight of distilled water and dispersing them. A palladium plating solution (pH 7.0) containing 0.30 mol / L of palladium sulfate, 0.95 mol / L of sodium hypophosphite, and 0.80 mol / L of ethylenediamine was prepared. The palladium plating solution was gradually added dropwise to the suspension to perform palladium reduction plating to obtain conductive particles. Conductive particles having an epoxy group on the outer surface of the conductive layer (nickel-boron layer thickness 0.1 μm, palladium layer thickness 0.01 μm) using the obtained conductive particles in the same manner as in Example 1. Got.

Example 9
Conductive particles were prepared in which the surfaces of the resin particles used in Example 1 were coated with a nickel-boron conductive layer (thickness: 0.1 μm). A suspension was obtained by adding 10 parts by weight of the conductive particles to 500 parts by weight of distilled water and dispersing them. A gold plating solution (pH 5.0) containing 0.30 mol / L of potassium gold cyanide, 0.50 mol / L of sodium citrate, and 0.43 mol / L of ethylenediaminetetraacetic acid was prepared. The gold plating solution was gradually dropped into the suspension to perform gold displacement plating to obtain conductive particles. Using the obtained conductive particles, conductive particles having an epoxy group on the outer surface of the conductive layer (nickel-boron layer thickness 0.09 μm, gold layer thickness 0.01 μm) in the same manner as in Example 1. Got.

(Example 10)
In the same manner as in Example 1, except that the divinylbenzene copolymer resin particles having a particle size of 3.0 μm were changed to divinylbenzene copolymer resin particles having a particle size of 2.0 μm. Conductive particles having an epoxy group on the surface were obtained.

(Comparative Example 1)
The particles in which the nickel-boron conductive layer (thickness 0.1 μm) was arranged on the surface of the resin particles before introducing the epoxy group in Example 1 were prepared as the conductive particles of Comparative Example 1.

(Comparative Example 2)
Conductive particles having an amino group on the outer surface of the conductive layer were obtained in the same manner as in Example 1 except that 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was changed to 3-aminopropyltrioxysilane. Obtained.

(Comparative Example 3)
Conductive particles having a thiol group on the outer surface of the conductive layer were obtained in the same manner as in Example 1 except that 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane was changed to 3-mercaptopropyltrimethoxysilane. Obtained.

(Evaluation)
Preparation of conductive material A:
7 parts by weight of the obtained conductive particles, 25 parts by weight of bisphenol A type phenoxy resin (“PKHC” manufactured by Union Carbide Co., Ltd., weight average molecular weight 45000) and fluorene type epoxy resin (“CG-300-” manufactured by Osaka Gas Chemical Co., Ltd.) 4 parts by weight of M2 ") and 30 parts by weight of phenol novolac type epoxy resin (" N-730A "manufactured by DIC), mixed solvent (weight ratio) of methyl ethyl ketone / PEGMEA (poly (ethylene glycol) methyl ether acrylate) To obtain a solution having a solid content of 40% by weight. A cationic polymerizable catalyst-type curing agent (“SI-60L” manufactured by Sanshin Chemical Industry Co., Ltd.) is further blended, defoamed and stirred for 3 minutes, and then dried to obtain a conductive material A (anisotropic conductive film). It was.

Preparation of conductive material B:
3 parts by weight of the obtained conductive particles, 25 parts by weight of a bisphenol A / bisphenol F mixed phenoxy resin (“YP-50” manufactured by Tohto Kasei Co., Ltd., weight average molecular weight 60000), dicyclopentadiene dimethacrylate (Shin Nakamura Chemical Co., Ltd.) 15 parts by weight of “DCP” manufactured by the company, 10 parts by weight of urethane acrylate (“M-1600” manufactured by Toagosei Co., Ltd.), 1 part by weight of phosphorus-containing methacrylate (“PM2” manufactured by Nippon Kayaku Co., Ltd.), and diacyl par Methyl ethyl ketone / toluene = 50 / part of 5 parts by weight of an oxide initiator (“PAROIL L” manufactured by NOF Corporation) and 1 part by weight of acrylic rubber (“SG-600LB” manufactured by Nagase ChemteX Corporation, weight average molecular weight 1200000) It was dissolved in 50 mixed solvent (50/50 by weight) to obtain a solution having a solid content of 40% by weight. After defoaming and stirring for 3 minutes, the mixture was dried to obtain a conductive material B (anisotropic conductive film).

Production of connection structure A:
A transparent glass substrate having an AL / Ti electrode pattern having an L / S of 30 μm / 30 μm on the upper surface was prepared. Further, a semiconductor chip having a gold electrode pattern with L / S of 30 μm / 30 μm on the lower surface was prepared.

  On the transparent glass substrate, the obtained conductive material A was applied to a thickness of 30 μm to form an anisotropic conductive film. Next, the semiconductor chip was laminated on the anisotropic conductive film so that the electrodes face each other. Thereafter, a pressure heating head is placed on the upper surface of the semiconductor chip while adjusting the head temperature so that the temperature of the anisotropic conductive film becomes 185 ° C., and the pressure of 1 MPa is applied to the anisotropic conductive film at 185 ° C. To obtain a connection structure A.

Production of connection structure B:
A connection structure B was obtained in the same manner as the connection structure A except that the conductive material A was changed to the conductive material B.

(1) Presence or absence of remaining bubbles Cross section polisher (CP) processing is performed on the cross sections of connection structures A and B, and the processed cross section is subjected to FE-TEM analysis (“JEM-ARM200F” manufactured by JEOL Ltd., magnification of 20,000 times). went. In the obtained connection structures A and B, it was evaluated whether bubbles remained around the conductive particles. The presence or absence of remaining bubbles was determined according to the following criteria.

[Judgment criteria for remaining bubbles]
○: Number of remaining bubbles 0 to less than 5 in 100 observed particles Δ: Number of remaining bubbles 5 to 10 in 100 observed particles ×: Number of remaining bubbles in 100 observed particles 10 or more

(2) Conduction reliability (connection resistance)
The connection resistance between the upper and lower electrodes of the obtained connection structures A and B was measured by a four-terminal method. The average value of the two connection resistances was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. The conduction reliability was determined according to the following criteria.

[Judgment criteria for conduction reliability]
○: The average value of connection resistance is 3.0Ω or less △: The average value of connection resistance is over 3.0Ω, 10.0Ω or less ×: The average value of connection resistance is over 10.0Ω

(3) Adhesiveness Using a “die shear tester Dage series 4000, load cell DS 100” manufactured by Dage, the die shear strength of the obtained connection structures A and B was measured. The adhesiveness between the cured binder resin and the semiconductor chip was evaluated. Adhesion was determined according to the following criteria.

[Adhesion criteria]
○: 600N or more Δ: 400N or more, less than 600N ×: less than 400N

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle 1a ... Protrusion 2 ... Base material particle 3 ... Conductive layer (conductive part)
3a ... Projection 4 ... Core material 11 ... Conductive particle 11a ... Projection 12 ... Conductive layer (conductive part)
12a ... Protrusions 21 ... Conductive particles 22 ... Conductive layer (conductive part)
DESCRIPTION OF SYMBOLS 51 ... Connection structure 52 ... 1st connection object member 52a ... Electrode 53 ... 2nd connection object member 53a ... Electrode 54 ... Connection part

Claims (10)

Conductive particles used dispersed in a binder resin,
At least the surface has a conductive part,
On the outer surface of the conductive part has an organic functional group that is an epoxy group or a (meth) acryloyl group ,
After introducing a first reactive functional group by the front surface treatment on the outer surface of the conductive portion, an epoxy group or (meth) second reactive functional capable of reacting acryloyl group and the first reactive functional group Conductive particles obtained by reacting the first reactive functional group with the second reactive functional group using a second compound having a group.   2. The conductive particle according to claim 1, wherein the conductive part has a melting point of 300 ° C. or higher, and has the organic functional group on the outer surface of the conductive part having a melting point of 300 ° C. or higher.   The compound obtained by bonding the compound so that the epoxy group or the (meth) acryloyl group remains on the outer surface of the conductive portion using a compound having an epoxy group or a (meth) acryloyl group, 2. Conductive particles according to 2.   The electroconductive particle of Claim 3 whose molecular weight of the compound which has the said epoxy group or (meth) acryloyl group is 100-300. The compound for introducing an organic functional group which is an epoxy group or a (meth) acryloyl group on the outer surface of the conductive part is a compound having an epoxy group or a (meth) acryloyl group,
The electroconductive particle of any one of Claims 1-4 whose epoxy equivalent or (meth) acryloyl equivalent of the compound which has the said epoxy group or (meth) acryloyl group is 100-300.   The electroconductive particle of any one of Claims 1-5 in which the said electroconductive part has a processus | protrusion on an outer surface. It is used by being dispersed in a binder resin and is a method for producing conductive particles having at least a conductive part on the surface,
By using a compound having an epoxy group or a (meth) acryloyl group and bonding the compound so that the epoxy group or the (meth) acryloyl group remains on the outer surface of the conductive part, And a step of obtaining conductive particles having an organic functional group which is an epoxy group or a (meth) acryloyl group ,
After introducing a first reactive functional group by the front surface treatment on the outer surface of the conductive portion, an epoxy group or (meth) second reactive functional capable of reacting acryloyl group and the first reactive functional group The manufacturing method of the electroconductive particle which obtains electroconductive particle by making the said 1st reactive functional group react with the said 2nd reactive functional group using the 2nd compound which has group.   The electrically-conductive material containing the electroconductive particle of any one of Claims 1-6, and binder resin.   The conductive material according to claim 8, wherein the binder resin contains a compound having an epoxy group or a (meth) acryloyl group as a thermosetting compound. A first connection target member;
A second connection target member;
A connection portion connecting the first connection target member and the second connection target member;
The connection structure in which the said connection part is formed with the electrically-conductive material containing the electroconductive particle and binder resin of any one of Claims 1-6.

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