JP6084866B2 - Conductive particles, conductive materials, and connection structures - Google Patents

Description

  The present invention relates to conductive particles that can be used for electrical connection between electrodes, for example. 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 Documents 1 and 2 disclose conductive particles in which a nickel layer is formed on the surface of a base particle. Patent Document 1 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. In Patent Documents 1 and 2, a metal oxide layer containing cerium or titanium is formed on the surface of the nickel layer, and a compound having an alkyl group having 6 to 22 carbon atoms is formed on the surface of the metal oxide layer. Bonding conductive particles are described.

  Patent Document 3 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 2010-103080 A JP 2010-103081 A JP 2010-086664 A

  In the conventional conductive particles, when an alkyl group having 6 to 22 carbon atoms is present on the surface of the conductive layer, the surface of the conductive layer becomes hydrophobic. Therefore, rust is hardly generated on the surface of the conductive layer by a corrosive gas in the atmosphere or a corrosive substance in the anisotropic conductive material. For this reason, high conductivity can be maintained over a long period of time. As a result, when the electrodes are connected by the conductive particles, an increase in the connection resistance between the electrodes can be suppressed.

  On the other hand, conductive particles are often dispersed in a binder resin and used as an anisotropic conductive material. In the case of conductive particles having an alkyl group having 6 to 22 carbon atoms on the surface of the conductive layer, the dispersibility of the conductive particles in the binder resin may not be sufficiently high.

  The object of the present invention is that rust is hardly generated in the conductive part, and high conductivity can be maintained for a long period of time. Therefore, when the electrodes are connected, the conduction reliability can be improved and further dispersed in the binder resin. It is providing the electroconductive particle which can be obtained, and 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, at least a surface of which is a conductive part, disposed on the outer surface of the conductive part, and non-conductive Conductive particles having a coating having a polar group and a polar group are provided.

  On the specific situation with the electroconductive particle which concerns on this invention, the said film is formed with the compound which has a nonpolar group, and the compound which has a polar group.

  In another specific aspect of the conductive particle according to the present invention, at least one of the compound having the nonpolar group and the compound having the polar group has a functional group capable of binding to the conductive part.

  On the other specific situation of the electroconductive particle which concerns on this invention, the molecular weight of the said nonpolar group in the said film is 100 or more.

  On the other specific situation of the electroconductive particle which concerns on this invention, the molecular weight of the said polar group in the said film is 80 or more.

  In another specific aspect of the conductive particle according to the present invention, the nonpolar group in the coating is an alkyl group.

  On another specific situation of the electroconductive particle which concerns on this invention, the said polar group in the said film is an alkylene oxide group.

  On the other specific situation of the electroconductive particle which concerns on this invention, in the said film, ratio of the number of the said nonpolar group and the number of the said polar groups is 1: 1-5: 1.

  On the other specific situation of the electroconductive particle which concerns on this invention, the thickness of the said film is 5 nm or more and 100 nm 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.

  The conductive material according to the present invention includes the conductive particles described above and a binder resin.

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

  Since the conductive particles according to the present invention include particles having at least a surface as a conductive part, and a coating film that is disposed on the outer surface of the conductive part and has a nonpolar group and a polar group, Rust hardly occurs in the conductive part, and high conductivity can be maintained over a long period. Therefore, when the electrodes are connected using the conductive particles according to the present invention, the conduction reliability between the electrodes can be improved. Furthermore, the electroconductive particle which concerns on this invention can be favorably disperse | distributed in binder resin.

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 cross-sectional view showing conductive particles according to the fourth embodiment of the present invention. FIG. 5 is a front 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 a particle | grain whose surface is a conductive part at least, and the film arrange | positioned on the outer surface of this electroconductive part. The coating has a nonpolar group and a polar group.

  Since the electroconductive particle which concerns on this invention is equipped with the structure mentioned above, since it is equipped with the film which has a nonpolar group and a polar group especially, it can make it difficult to produce rust in an electroconductive part. Furthermore, the electroconductive particle which concerns on this invention can be favorably disperse | distributed in binder resin.

  The particles having at least a conductive portion on the surface may be particles having base material particles and conductive portions arranged on the surface of the base material particles, and are metal particles having a conductive portion as a whole. Also good. The conductive part is preferably a conductive layer. Above all, from the viewpoint of reducing the cost or increasing the flexibility of the conductive particles and further improving the conduction reliability between the electrodes, the base particles are arranged on the surface of the base particles. Particles having a conductive part formed are 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, a coating 4, a plurality of insulating substances 5, and a plurality of core substances 6. The conductive particle 1 includes a base particle 2 and a particle having a conductive layer 3 disposed on the surface of the base particle 2. The conductive layer 3 is a conductive part.

  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 coating 4 has a nonpolar group and a polar group. The coating 4 is disposed on the outer surface of the conductive layer 3. The coating 4 covers the outer surface of the conductive layer 3 and the surface of the insulating material 5.

  The insulating material 5 is disposed on the outer surface of the conductive layer 3. An insulating material 5 is attached to the surface of the conductive layer 3. The insulating substance 5 is made of an insulating material and is an insulating particle. Thus, the electroconductive particle which concerns on this invention may have the insulating substance arrange | positioned on the outer surface of an electroconductive part. However, the conductive particles according to the present invention do not necessarily have an insulating material.

  The portion of the coating 4 covering the outer surface of the conductive layer 3 and the portion of the coating 4 covering the surface of the insulating material 5 are continuous. The coating 4 covers the outer surface of the conductive layer 3 to which the insulating substance 5 is attached. The coating 4 is not disposed on the portion of the conductive layer 3 that is in contact with the insulating material 5, and is not disposed between the conductive layer 3 and the insulating material 5. The coating 4 only needs to be disposed in a partial region of the outer surface of the conductive layer 3, and may not be disposed in the entire region of the outer surface of 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 6 are arranged on the surface of the base particle 2. A plurality of core materials 6 are embedded in the conductive layer 3. The core material 6 is disposed inside the protrusions 1a and 3a. The conductive layer 3 covers a plurality of core materials 6. The outer surface of the conductive layer 3 is raised by a plurality of core materials 6 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, a conductive layer 12, and a coating 13. The conductive particles 11 include base material particles 2 and particles having a conductive layer 12 disposed on the surface of the base material particles 2. The conductive layer 12 is a conductive part. The conductive particles 1 and the conductive particles 11 differ only in the location of the coating and the presence or absence of the 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.

  The coating 13 has a nonpolar group and a polar group. The coating 13 is disposed on the outer surface of the conductive layer 12. The coating 13 covers the outer surface of the conductive layer 12. A coating 13 is disposed on the entire area of the outer surface of the conductive layer 12. The entire outer surface of the conductive layer 12 is covered with the coating 13.

  The coating 13 does not cover the surface of the insulating material 5. The coating 13 covers the outer surface of the conductive layer 12 before the insulating material 5 is attached. The coating 13 is disposed between the conductive layer 12 and the insulating material 5.

  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, a conductive layer 22, a coating 23, and a plurality of insulating substances 5. The conductive particles 21 include base particles 2 and particles having a conductive layer 22 disposed on the surface of the base particles 2. The conductive layer 22 is a conductive part.

  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. As described above, the portion excluding the insulating substance in the conductive particles according to the present invention may not have a protrusion and may be spherical.

  The coating 23 has a nonpolar group and a polar group. The coating 23 is disposed on the outer surface of the conductive layer 22. The insulating material 5 is disposed on the surface of the conductive layer 22. The insulating material 5 is attached to the surface of the conductive layer 22. The coating 23 covers the outer surface of the conductive layer 22 and the surface of the insulating material 5.

  The conductive particles 21 do not have a core substance. The outer surface of the conductive layer 22 is spherical. The coating 23 is disposed on the outer surface of the conductive layer 22. The coating 23 covers the outer surface of the conductive layer 22. The insulating material 5 is disposed on the surface of the conductive layer 22 with a film 32 interposed therebetween. The insulating material 5 is disposed on the outer surface of the coating 32. The insulating material 5 is attached to the outer surface of the coating 32.

  In FIG. 4, the electroconductive particle which concerns on the 4th Embodiment of this invention is shown with sectional drawing.

  A conductive particle 31 shown in FIG. 4 includes a base particle 2, a conductive layer 22, and a coating 32. The conductive particles 31 include base particles 2 and particles having the conductive layer 22 disposed on the surface of the base particles 2. The conductive particles 21 and the conductive particles 31 differ only in the location of the coating and the presence or absence of an insulating material.

  The coating 32 has a nonpolar group and a polar group. The coating 32 is disposed on the outer surface of the conductive layer 22. The coating 32 covers the outer surface of the conductive layer 22. A coating 32 is disposed on the entire outer surface of the conductive layer 22. The entire outer surface of the conductive layer 22 is covered with the coating 32.

  The conductive particles 31 do not have an insulating material. An insulating material may be disposed on the surface of the conductive layer 22 via the coating 32. The insulating material may be disposed on the outer surface of the coating 32. The insulating material may adhere to the outer surface of the coating 32.

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

(Conductive particles)
[Coating]
The coating has a nonpolar group and a polar group. The said nonpolar group improves the hydrophobicity of the surface of electroconductive particle, and suppresses effectively that rust arises in an electroconductive part. Therefore, the nonpolar group maintains high conductivity in the conductive particles and contributes to effectively suppressing an increase in connection resistance between the electrodes. The polar group contributes to effectively increasing the dispersibility of the conductive particles in the binder resin.

  The film can be formed of a compound having a nonpolar group and a compound having a polar group, and can be formed of a compound having a nonpolar group and a polar group. The coating is preferably formed of a compound having a nonpolar group and a compound having a polar group. The conductive particles in the binder resin are formed by forming a film with the compound having the nonpolar group and the compound having the polar group, instead of forming the compound with the nonpolar group and the polar group. Dispersibility can be further improved. The film may be formed of a compound having the nonpolar group and the polar group. The nonpolar group in the coating is preferably introduced from a compound having the nonpolar group. The polar group in the coating is preferably introduced from a compound having the polar group.

The nonpolar group is a functional group having no charge. Examples of the nonpolar group include an alkyl group and a phenyl group. The nonpolar group is preferably an alkyl group or a phenyl group. From the viewpoint of further reducing rust in the conductive portion and further reducing the connection resistance between the electrodes, the nonpolar group is preferably an alkyl group. The number of carbon atoms of the alkyl group is preferably 6 or more, preferably 22 or less, more preferably 16 or less. When the carbon number of the alkyl group is not less than the above lower limit, rust is less likely to occur in the conductive portion, and the connection resistance between the electrodes is effectively reduced. When the carbon number of the alkyl group is not more than the above upper limit, a decrease in conductivity in the conductive particles can be suppressed.

The molecular weight of the nonpolar group is preferably 100 or more, more preferably 200 or more. When the molecular weight of the nonpolar group is not less than the above lower limit and not more than the above upper limit, rust is more unlikely to occur in the conductive part, and the decrease in conductivity in the conductive particles is further suppressed.

  Examples of the compound having a nonpolar group include compounds having an alkyl group or a phenyl group.

  Examples of the compound having an alkyl group include a phosphate ester having an alkyl group or a salt thereof, an alkoxysilane having an alkyl group, an alkylthiol having an alkyl group, and a dialkyl disulfide having an alkyl group.

  Examples of the phosphoric acid ester having an alkyl group or a salt thereof include, for example, hexyl phosphate, heptyl phosphate, monooctyl phosphate, monononyl phosphate, monodecyl phosphate, monoundecyl phosphate. , Monododecyl phosphate, monotridecyl phosphate, monotetradecyl phosphate, monopentadecyl phosphate, monohexyl phosphate monosodium salt, monoheptyl phosphate monosodium salt, monooctyl phosphate Ester monosodium salt, phosphate monononyl ester monosodium salt, phosphate monodecyl ester monosodium salt, phosphate monoundecyl ester monosodium salt, phosphate monododecyl ester monosodium salt, phosphate monotride Ester monosodium salt, phosphate acid mono tetradecyl ester monosodium salt, and phosphoric acid mono-pentadecyl ester monosodium salt.

  Examples of the alkoxysilane having an alkyl group include hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxy. Silane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxy Examples include silane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane, and pentadecyltriethoxysilane.

  Examples of the alkyl thiol having the alkyl group include hexyl thiol, heptyl thiol, octyl thiol, nonyl thiol, decyl thiol, undecyl thiol, dodecyl thiol, tridecyl thiol, tetradecyl thiol, pentadecyl thiol, and hexadecyl thiol. Etc. The alkyl thiol preferably has a thiol group at the end of the alkyl group.

Examples of the dialkyl disulfide having an alkyl group include dihexyl disulfide, diheptyl disulfide, dioctyl disulfide, dinonyl disulfide, didecyl disulfide, diundecyl disulfide, didodecyl disulfide, ditridecyl disulfide, ditetradecyl disulfide, dipentadecyl. Examples include disulfide and dihexadecyl disulfide.

  The polar group is a functional group having a charge. Preferred examples of the polar group include an alkylene oxide group, a hydroxyl group, and a carbonyl group. From the viewpoint of further improving the dispersibility of the conductive particles in the binder resin, the polar group is preferably an alkylene oxide group. The alkylene oxide group has 1 or more carbon atoms, preferably 12 or less, more preferably 8 or less. When the carbon number of the alkylene oxide group is not more than the above upper limit, a decrease in conductivity in the conductive particles can be suppressed. The alkylene oxide group is particularly preferably an ethylene oxide group.

  The molecular weight of the polar group is preferably 80 or more, more preferably 100 or more, and still more preferably 200 or more. When the molecular weight of the polar group is not less than the above lower limit and not more than the above upper limit, the dispersibility of the conductive particles in the binder resin is further enhanced, and the decrease in conductivity in the conductive particles is further suppressed.

  Examples of the compound having a polar group include a compound having an alkylene oxide group, a compound having a hydroxyl group, and a compound having a carbonyl group. The compound having a polar group is preferably a compound having an alkylene oxide group, a compound having a hydroxyl group, or a compound having a carbonyl group.

From the viewpoint of further improving the conduction reliability between the electrodes and the dispersibility of the conductive particles, the ratio of the number of the nonpolar groups to the number of the polar groups in the coating (number of nonpolar groups: polar groups) The number) is preferably from 1:10 to 50: 1, more preferably from 1: 1 to 5: 1.

  The ratio (number of nonpolar groups: number of polar groups) can be determined by, for example, time-of-flight secondary ion mass spectrometry (TOF-SIMS analysis). From the spectral intensity derived from the nonpolar group and the spectral intensity derived from the polar group, the ratio (number of nonpolar groups: number of polar groups) can be determined.

  At least one of the compound having a nonpolar group and the compound having a polar group preferably has a functional group capable of binding to the conductive part. At least one of the compound having a nonpolar group and the compound having a polar group may have a functional group capable of binding to the conductive part. In the conductive particles, it is preferable that the conductive part and a functional group that can be bonded to the conductive part are bonded. The bond is preferably a chemical bond. The chemical bond includes a covalent bond, a hydrogen bond, an ionic bond, a coordination bond, and the like.

  Preferred examples of the functional group that can be bonded to the conductive part include an alkylene oxide group, a hydroxyl group, and a carbonyl group. The functional group that can be bonded to the conductive part is preferably an alkylene oxide group, a hydroxyl group, or a carbonyl group. Among these, from the viewpoint of further firmly bonding the conductive part and the film and further suppressing peeling of the film, the functional group that can be bonded to the conductive part is preferably an alkylene oxide group.

  The thickness of the coating is not particularly limited. The thickness of the coating film exceeds 0 nm, preferably 5 nm or more, preferably 100 μm or less, more preferably 10 μm or less, still more preferably 1 μm or less, particularly preferably 100 nm or less, and most preferably 10 nm or less. When the thickness of the coating is equal to or more than the lower limit, rust is less likely to occur in the conductive portion, and the dispersibility of the conductive particles in the binder resin is further enhanced. When the thickness of the coating is less than or equal to the above upper limit, the decrease in conductivity in the conductive particles is further suppressed.

[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, and more preferably resin particles, inorganic particles excluding metal, 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 Ketones, polyether sulfones, 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 Child-containing (meth) acrylates; Nitrile-containing monomers such as (meth) acrylonitrile; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; Vinyl acetates such as vinyl acetate, vinyl butyrate, vinyl laurate, and 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 di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanurate, tria Rutorimeriteto, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, .gamma. (meth) acryloxy propyl trimethoxy silane, trimethoxy silyl styrene, include silane-containing monomers such as vinyltrimethoxysilane.

  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. Although it does not specifically limit as the particle | grains formed with the said silica, For example, after hydrolyzing the silicon compound which has two or more hydrolysable alkoxysil groups, and forming a crosslinked polymer particle, it calcinates as needed. 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. In the case where at least the whole of the grains whose surface is the conductive part is metal particles which are the conductive part, the metal for forming the metal particles is not particularly limited. 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 these. And the like. 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.

  As the metal constituting the conductive part is more likely to be rusted, the coating effect by the coating is more remarkable. In the conductive part formed of nickel, copper or tin, rust is relatively likely to occur on the surface of the conductive part. By covering the surface of such a conductive part with a film, it is possible to effectively suppress the occurrence of rust on the surface of the conductive part. Since the covering effect by the said film is acquired effectively, the said electroconductive part may contain nickel, copper, or tin.

  In many cases, hydroxyl groups are present on the surface of the conductive portion by oxidation. In general, a hydroxyl group exists on the surface of a conductive portion formed of nickel by oxidation. Such a conductive part having a hydroxyl group is easily chemically bonded to the film.

  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, a copper layer, or an alloy layer containing tin and silver, and is a gold layer. Is more preferable. 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 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 surface of the conductive portion are used, the oxide film can be effectively eliminated by the protrusions by placing 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, the core substance is not necessarily used in order to form protrusions on the surfaces of the conductive particles and the conductive part. That is, the protrusions may be formed on the surfaces of the conductive particles and 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.

[Insulating material]
The conductive particles according to the present invention preferably include an insulating substance disposed on the surface of the conductive part. In this case, when the conductive particles are used for connection between the electrodes, a short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles are in contact with each other, an insulating material is present between the plurality of electrodes, so that it is possible to prevent a short circuit between electrodes adjacent in the lateral direction instead of between the upper and lower electrodes. Note that the insulating material between the conductive portion and the electrode can be easily removed by pressurizing the conductive particles with the two electrodes when connecting the electrodes. When the conductive particles have a plurality of protrusions on the outer surface of the conductive part, the insulating material between the conductive part of the conductive particles and the electrode can be more easily removed.

  It is preferable that the insulating material is an insulating particle because the insulating material can be more easily removed when the electrodes are pressed.

  Specific examples of the insulating resin that is the material of the insulating material include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked thermoplastic resins, and thermosetting. Resin, water-soluble resin, and the like.

  Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ester copolymer. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. As said thermosetting resin, an epoxy resin, a phenol resin, a melamine resin, etc. are mentioned. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide, and methyl cellulose. Of these, water-soluble resins are preferable, and polyvinyl alcohol is more preferable.

  From the viewpoint of further increasing the detachability of the insulating particles during thermocompression bonding, the insulating particles are preferably inorganic particles, and are preferably silica particles. Examples of the inorganic particles include shirasu particles, hydroxyapatite particles, magnesia particles, zirconium oxide particles, and silica particles. Examples of the silica particles include pulverized silica and spherical silica, and spherical silica is preferably used.

  Examples of a method for disposing an insulating material on the surface of the conductive part include a chemical method and a physical or mechanical method. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion, spraying, dipping, and vacuum deposition. In particular, since the insulating substance is difficult to be detached, a method in which the insulating substance is disposed on the surface of the conductive part or the surface of the film via a chemical bond is preferable.

  The average diameter (average particle diameter) of the insulating material can be appropriately selected depending on the particle diameter of the conductive particles, the use of the conductive particles, and the like. The average diameter (average particle diameter) of the insulating material is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, more preferably 0.5 μm or less. When the average diameter of the insulating material is not less than the above lower limit, when the conductive particles are dispersed in the binder resin, the conductive portions in the plurality of conductive particles are difficult to contact each other. When the average diameter of the insulating particles is not more than the above upper limit, it is not necessary to make the pressure too high in order to eliminate the insulating material between the electrodes and the conductive particles when the electrodes are connected. There is no need for heating.

  The “average diameter (average particle diameter)” of the insulating material indicates a number average diameter (number average particle diameter). The average diameter of the insulating material is obtained using a particle size distribution measuring device or the like.

(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 binder resin is not particularly limited. As the binder resin, a known insulating resin is used.

  Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

  Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include an epoxy resin, a urethane resin, a polyimide resin, and an unsaturated polyester resin. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogenated product of a styrene block copolymer. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

  In addition to the conductive particles and the binder resin, 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 and 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 and kneaded 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 according to the present invention 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. When the content of the binder resin 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 is further increased.

  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 (such as an anisotropic conductive material) containing conductive particles and a binder resin is preferable.

  In FIG. 5, the connection structure using the electroconductive particle which concerns on the 1st Embodiment of this invention is typically shown with front sectional drawing.

  The connection structure 51 shown in FIG. 5 includes a first connection target member 52, a second connection target member 53, and a connection portion 54 connecting 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. 5, the conductive particles 1 are schematically shown for convenience of illustration. Instead of the conductive particles 1, conductive particles 11, 21, 31 and the like may be used.

  The first connection target member 52 has a plurality of electrodes 52b on the surface 52a (upper surface). The second connection target member 53 has a plurality of electrodes 53b on the surface 53a (lower surface). The electrode 52 b and the electrode 53 b 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 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, the suspension is filtered to take out the particles, which are washed with water and dried, so that the surface on which the nickel-boron conductive layer (thickness 0.1 μm) is disposed on the surface of the resin particles is a conductive layer. Got.

  In a mixed solution of 25 g of pure water and 25 g of ethanol, 10 parts by weight of the conductive particle body, 0.5 part by weight of monohexyl phosphate (a compound having a nonpolar group), and polyoxyethylene tridodecyl ether phosphate (ethylene oxide) Chain length: 5) (a compound having a polar group) 0.5 part by weight was added and stirred at 50 ° C. for 1 hour. Then, it is filtered and dried at 100 ° C. for 8 hours by a vacuum dryer, and the monohexyl phosphate and the polyoxyethylene tridodecyl ether phosphate are formed on the outer surface of the conductive layer of the particle whose surface is a conductive layer. The electroconductive particle which has the film formed by this was obtained.

(Example 2)
Conductive particles were obtained in the same manner as in Example 1 except that the amount of phosphoric acid monohexyl ester (compound having a nonpolar group) was changed from 0.5 parts by weight to 2.5 parts by weight.

(Example 3)
Conductive particles were obtained in the same manner as in Example 1 except that monohexyl phosphate (compound having a nonpolar group) was changed to monooctyl phosphate.

Example 4
Conductive particles were obtained in the same manner as in Example 1 except that the amount of phosphoric acid monohexyl ester (compound having a nonpolar group) was changed from 0.5 parts by weight to 5.0 parts by weight.

(Comparative Example 1)
In a mixed solution of 25 g of pure water and 25 g of ethanol, 10 parts by weight of particles whose surface is a conductive layer obtained in Example 1 and 0.5 parts by weight of monohexyl phosphate (compound having a nonpolar group) And stirred at 50 ° C. for 1 hour. Thereafter, the mixture is filtered and dried at 100 ° C. for 8 hours by a vacuum dryer, and conductive particles having a film formed of the monohexyl phosphate are formed on the outer surface of the conductive layer of the particles whose surface is a conductive layer. Obtained.

(Example 5)
Conductive particles were obtained in the same manner as in Example 1 except that monohexyl phosphate (a compound having a nonpolar group) was changed to monododecyl phosphate.

(Example 6)
Except that phosphoric acid polyoxyethylene tridodecyl ether (ethylene oxide chain length: 5) (compound having a polar group) was changed to phosphoric acid polyoxyethylene tridodecyl ether (ethylene oxide chain length: 10), the same as in Example 1. Thus, conductive particles were obtained.

(Example 7)
Except that phosphoric acid polyoxyethylene tridodecyl ether (ethylene oxide chain length: 5) (compound having a polar group) was changed to phosphoric acid polyoxyethylene tridodecyl ether (ethylene oxide chain length: 20), the same procedure as in Example 1 was performed. Thus, conductive particles were obtained.

(Evaluation)
(1) Time-of-flight secondary ion mass spectrometry (TOF-SIMS analysis)
Time-of-flight secondary ion mass spectrometry TOF-SIMS (TOF-SIMS type 5 manufactured by ION-TOF Co., Ltd.), the spectral intensity derived from the nonpolar group and the polar group in the coating disposed on the surface of the conductive layer And the spectral intensity derived from was measured. The ratio (number of nonpolar groups: number of polar groups) was determined.

(2) Dispersibility of conductive particles in binder resin The resulting conductive particles are added to and dispersed in Mitsui Chemicals' “Struct Bond XN-5A” so that the content is 10% by weight. Thus, an anisotropic conductive paste was produced.

  The anisotropic conductive paste immediately after production was left at 150 ° C. for 10 seconds. The anisotropic conductive paste after standing was observed, and the dispersibility of the conductive particles in the binder resin was determined according to the following criteria.

[Criteria for dispersibility of conductive particles in binder resin]
◯: There is no aggregate of 5 or more in 1000 particles ○: 1 to 5 aggregates of 5 or more in 1000 particles Δ: 6 to 10 aggregates of 5 or more in 1000 particles × : 11 or more aggregates of 5 or more of 1000 particles

(3) Conductivity evaluation (between upper and lower electrodes)
The obtained conductive particles were added to “Strectbond XN-5A” manufactured by Mitsui Chemicals Co., Ltd. so as to have a content of 10% by weight, and dispersed to prepare an anisotropic conductive paste.

  A transparent glass substrate having an ITO electrode pattern having an L / S of 30 μm / 30 μm on the upper surface was prepared. Moreover, the semiconductor chip which has a copper electrode pattern whose L / S is 30 micrometers / 30 micrometers on the lower surface was prepared.

  On the said transparent glass substrate, the anisotropic conductive paste immediately after preparation was applied so that it might become thickness of 30 micrometers, and the anisotropic conductive paste layer was formed. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 1 MPa is applied to form the anisotropic conductive paste layer. It hardened | cured at 185 degreeC and the connection structure was obtained.

  The connection resistance between the upper and lower electrodes of the obtained connection structure 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 continuity evaluation was determined according to the following criteria.

[Judgment criteria for continuity evaluation]
○: The average value of connection resistance is 2Ω or less ×: The average value of connection resistance exceeds 2Ω

(4) Insulation evaluation (between adjacent electrodes in the horizontal direction)
In the connection structure produced by the above continuity evaluation, the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance with a tester. Insulation evaluation was determined according to the following criteria.

[Criteria for insulation evaluation]
○: Resistance exceeds 500 MΩ (no leakage)
Δ: Resistance is 500 MΩ or less (leak)

(5) Rust prevention evaluation The connection structure produced by the above-mentioned insulation evaluation was left under conditions of 85 ° C. and relative humidity 85%. After 100 hours from the start of standing, the connection resistance between the electrodes was measured by the four-terminal method in the same manner as in the above continuity evaluation. The connection resistance was measured in the same manner as in the above continuity evaluation. Rust prevention evaluation was determined according to the following criteria.

[Criteria for rust prevention evaluation]
○: Compared to the average value of connection resistance (before leaving), the average value of connection resistance (after leaving) is less than 150% ×: Average value of secondary resistance (after leaving) compared to the average value of connection resistance (before leaving) Increased by more than 150%

  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 ... coating 5 ... insulating material 6 ... core material 11 ... conductive particles 11a ... projection 12 ... conductive layer (conductive portion)
12a ... Protrusions 13 ... Coating 21 ... Conductive particles 22 ... Conductive layer (conductive part)
DESCRIPTION OF SYMBOLS 23 ... Coating 31 ... Conductive particle 32 ... Coating 51 ... Connection structure 52 ... 1st connection object member 52a ... Surface 52b ... Electrode 53 ... 2nd connection object member 53a ... Surface 53b ... Electrode 54 ... Connection part

Claims (11)

Conductive particles used dispersed in a binder resin,
Particles whose surface is at least a conductive part;
A coating that is disposed on the outer surface of the conductive part and has a nonpolar group and a polar group ;
The particles having at least a conductive part on the surface are base particles and particles having conductive parts arranged on the surface of the base particles,
The substrate particles are resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles,
The electroconductive particle in which the said film is formed with the compound which has a nonpolar group, and the compound which has a polar group . Wherein at least one of the compounds having the compound and the polar group having a non-polar group, having a binding functional group and the conductive portion, the conductive particle according to claim 1. The electroconductive particle of Claim 1 or 2 whose molecular weight of the said nonpolar group in the said film is 100 or more. The electroconductive particle of any one of Claims 1-3 whose molecular weight of the said polar group in the said film is 80 or more. Wherein the coating non-polar group is an alkyl group, a conductive particle according to any one of claims 1-4. The electroconductive particle of any one of Claims 1-5 whose said polar group in the said film is an alkylene oxide group. In the film, the ratio between the number of the polar groups to the number of the non-polar group, 1: 1 to 5: 1 is a conductive particle according to any one of claims 1-6. The thickness of the coating is 5nm or more and 100nm or less, the conductive particles according to any one of claims 1-7. The electroconductive particle of any one of Claims 1-8 in which the said electroconductive part has a processus | protrusion on an outer surface. And conductive particles according to any one of claims 1 to 9 and a binder resin, conductive material. A first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members;
The connecting portion is formed of a conductive material containing conductive particles and a binder resin according to any one of claims 1 to 9 connected structure.

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