JP6641341B2 - Conductive particle material, conductive material, connection structure, and method of manufacturing connection structure - Google Patents

Description

  The present invention relates to a conductive particle material including a plurality of conductive particles in which a conductive layer is disposed on the surface of a substrate particle, and more specifically, for example, conductive particles used for electrical connection between electrodes About the material. The present invention also relates to a conductive material, a connection structure, and a method for manufacturing the connection structure using the conductive particle material.

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

  In order to obtain various connection structures, the anisotropic conductive material includes, for example, a connection between a flexible printed board and a glass substrate (FOG (Film on Glass)) and a connection between a semiconductor chip and a flexible printed board (COF ( Chip on Film), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed board and a glass epoxy substrate (FOB (Film on Board)), and the like.

  For example, when electrically connecting an electrode of a semiconductor chip and an electrode of a glass substrate with the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass substrate. Next, the semiconductor chips are stacked and heated and pressed. Thus, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

  As an example of the anisotropic conductive material, Patent Literature 1 below discloses an anisotropic conductive material including an adhesive composition that flows by heating, a first particle, and a second particle. I have. The first particle has a core mainly composed of a low melting point metal having a melting point of 130 to 250 ° C., and a resin composition covering the surface of the core and having a softening point lower than the melting point of the low melting point metal. And an insulating layer formed by: The second particles have a smaller average particle diameter than the core of the first particles. The main component of the second particles is a material having a higher melting point or a higher softening point than the melting point of the low melting point metal.

JP 2009-277652 A

  When a conventional anisotropic conductive material containing conductive particles as described in Patent Document 1 is used for connection between electrodes, it is difficult to efficiently arrange a plurality of conductive particles between electrodes. Sometimes. Further, there is a problem that it is difficult to arrange a plurality of conductive particles uniformly over a wide range.

  An object of the present invention is to provide a conductive particle material capable of uniformly disposing a plurality of conductive particles over a wide range when used for connection between electrodes, a conductive material using the conductive particle material, and a connection structure. It is to provide a method of manufacturing the body and the connection structure.

  According to a broad aspect of the present invention, there is provided a conductive particle material including a plurality of conductive particles each including a base particle and a first conductive layer disposed on a surface of the base particle, A conductive layer material having a melting point of 450 ° C. or lower and a CV value of a particle diameter of the conductive particles larger than a CV value of a particle diameter of the base particles.

  In a specific aspect of the conductive particle material according to the present invention, the base particles have a base particle body and a second conductive layer disposed on a surface of the base particle body, The melting point of the second conductive layer is higher than the melting point of the first conductive layer.

  In a specific aspect of the conductive particle material according to the present invention, the melting point of the second conductive layer exceeds 450 ° C.

  In a specific aspect of the conductive particle material according to the present invention, the absolute value of the difference between the CV value of the particle size of the conductive particles and the CV value of the particle size of the base particles is 1% or more and 10% or more. It is as follows.

  The conductive particle material according to the present invention is preferably dispersed in a binder resin and used as a conductive material.

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

  According to a wide aspect of the present invention, a first connection target member having a first electrode on a surface, a second connection target member having a second electrode on a surface, the first connection target member, A connection portion connecting the second connection target member, wherein the connection portion is formed of a conductive material including the conductive particle material and the binder resin described above, and the first electrode and the first electrode A connection structure is provided, wherein the connection structure is electrically connected to a second electrode by the conductive particles included in the conductive particle material.

  In a specific aspect of the connection structure according to the present invention, the conductive material is disposed in a first region, which is a partial region on the first electrode, to form a conductive material layer. The connection portion is formed by wet-spreading the conductive material layer in a second region around the region, and the amount of the first conductive layer in the conductive particles located in the first region Is larger than the amount of the first conductive layer in the conductive particles located in the second region.

  According to a wide aspect of the present invention, a conductive material including the above-described conductive particle material and a binder resin is arranged on a first connection target member having a first electrode on a surface to form a conductive material layer. And a step of laminating a second connection target member having a second electrode on the surface of the conductive material layer opposite to the first connection target member side; Heating and curing to form a connection portion, and connecting the first connection target member and the second connection target member by the connection portion, wherein the first electrode and the second A method for manufacturing a connection structure is provided, in which a connection structure in which an electrode is electrically connected by the conductive particles contained in the conductive particle material is obtained.

  In a specific aspect of the method for manufacturing a connection structure according to the present invention, the conductive material layer is formed in a first region that is a partial region on the first electrode, and the first region is formed. The connection portion is formed by wetting and spreading the conductive material layer in the surrounding second region, and the amount of the first conductive layer in the conductive particles located in the first region is equal to the second conductive region. In this case, a connection structure is obtained in which the amount of the first conductive layer in the conductive particles located in the region is larger than that of the first conductive layer.

  The conductive particle material according to the present invention includes a plurality of conductive particles each including base particles and a first conductive layer disposed on the surface of the base particles, and the first conductive layer has a melting point of 450. ° C. or less, since the CV value of the particle size of the conductive particles is larger than the CV value of the particle size of the base particles, when the conductive particle material according to the present invention is used for connection between electrodes, A plurality of conductive particles can be uniformly arranged over a wide range.

FIG. 1 is a cross-sectional view showing conductive particles included in the conductive particle material according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating conductive particles included in the conductive particle material according to the second embodiment of the present invention. FIG. 3 is a front sectional view schematically showing a connection structure using the conductive particle material according to the first embodiment of the present invention. FIGS. 4A to 4C are schematic front cross-sectional views illustrating each step of obtaining a connection structure using the conductive particle material according to the first embodiment of the present invention. FIGS. 5A and 5B are schematic plan views when a connection structure is obtained using the conductive particle material according to the first embodiment of the present invention, and FIG. FIG. 5B is a plan view showing a state immediately after disposing the conductive material layer, and FIG. 5B is a plan view showing the obtained connection structure. FIGS. 6A and 6B are schematic plan views illustrating a connection structure obtained using a plurality of conventional conductive particles.

  Hereinafter, details of the present invention will be described.

  The conductive particle material according to the present invention includes a plurality of conductive particles including base particles and a first conductive layer disposed on a surface of the base particles. The conductive particle material according to the present invention is an aggregate of the above conductive particles. The melting point of the first conductive layer is 450 ° C. or less. In the conductive particle material, the CV value of the particle size of the conductive particles is larger than the CV value of the particle size of the base particles. Therefore, in the conductive particle material, the particle diameters of the base particles are relatively uniform. In the conductive particle material, the particle size of the conductive particles varies relatively.

  By employing the above-described configuration in the conductive particle material according to the present invention, when the conductive particle material is used for connection between electrodes, a plurality of conductive particles can be efficiently arranged between the electrodes. For example, it is difficult to arrange a plurality of conductive particles collectively in a specific area, and it is easy to arrange a plurality of conductive particles uniformly over a wide range. As a result, it becomes difficult for a plurality of conductive particles to be collectively arranged in a specific region, so that the ratio of the conductive particles arranged in a space where there is no electrode is reduced, and the conductive particles arranged between the first and second electrodes are reduced. Can be increased. Furthermore, by using the conductive particle material according to the present invention, in the obtained connection structure, variation in the interval between the first and second electrodes is reduced, and the connection target member connected by the conductive particles is curved. It becomes difficult.

  The CV value (coefficient of variation) of the particle diameter is represented by the following equation.

  CV value (%) = (σn / Dn) × 100

For base particles:
σn: standard deviation of the particle diameter of the base particles Dn: number average particle diameter of the base particles

For conductive particles:
σn: standard deviation of the particle size of the conductive particles Dn: number average particle size of the conductive particles

  The conductive particle material according to the present invention is dispersed in a binder resin and is suitably used as a conductive material.

  From the viewpoint of efficiently arranging the plurality of conductive particles between the electrodes and uniformly arranging the plurality of conductive particles over a wide range, the CV value of the base particles is preferably 1% or more, more preferably. Is at least 2%, preferably at most 10%, more preferably at most 5%, even more preferably at most 4%. Further, when the CV value of the base particles is equal to or more than the lower limit and equal to or less than the upper limit, in the obtained connection structure, variation in the interval between the first and second electrodes is further reduced, and The connection target member to be connected is more difficult to bend.

  From the viewpoint of efficiently arranging the plurality of conductive particles between the electrodes and uniformly arranging the plurality of conductive particles over a wide range, the CV value of the particle diameter of the conductive particles and the The absolute value of the difference between the particle size and the CV value is preferably 1% or more, more preferably 3% or more, preferably 15% or less, more preferably 10% or less, further preferably 8% or less, and particularly preferably 5% or less. % Or less.

  The CV value of the conductive particles can be appropriately controlled by a conventionally known method. Also, the CV value of the base particles can be appropriately controlled by a conventionally known method. However, in the present invention, the conductive particles and the base particles are selected and used so that the CV value of the particle size of the conductive particles is larger than the CV value of the particle size of the base particles.

  In the above-mentioned conductive particle material, as a method of controlling the CV value of the conductive particles and the CV value of the particle size of the base particles, a conductive material selected (e.g., classified) using a sieve or the like to have a predetermined particle size is used. Method of using conductive particles, method of using base particles selected (e.g., classified) to have a predetermined particle size using a sieve or the like, and controlling the thickness of the first conductive layer formed on the surface of the base particles And the like. As a method of controlling the thickness of the first conductive layer, a method of controlling the thickness of the first conductive layer by theta composer, and a method of forming the first conductive layer by inorganic electrolytic plating, in the plating step There is a method in which the conductive particles on which the first conductive layer is formed are taken out a plurality of times (for example, the initial stage, the middle stage, and the late stage of plating). For example, in the case where the first conductive layer is a solder layer, when the raw material solder powder is put into the theta composer, a method in which the solder powder having a small particle diameter is initially charged and the solder powder having a large particle diameter is charged in a late stage And the like. Alternatively, a plurality of conductive particles each having a first conductive layer formed thereon may be mixed to obtain a conductive particle material.

  Hereinafter, the present invention will be clarified by giving specific embodiments and examples of the present invention with reference to the drawings.

(Conductive particle material)
FIG. 1 is a cross-sectional view showing conductive particles contained in the conductive particle material according to the first embodiment of the present invention.

  The conductive particles 1 shown in FIG. 1 include base particles 2 and a first conductive layer 3 disposed on the surface of the base particles 2. The conductive particles 1 are coated particles in which the surface of the base particles 2 is coated with the first conductive layer 3. The melting point of the first conductive layer 3 is 450 ° C. or less.

  The base particles 2 have a base particle body 6 and a second conductive layer 7 disposed on the surface of the base particle body 6. Accordingly, the conductive particles 1 are composed of the base particle body 6, the second conductive layer 7 disposed on the surface of the base particle body 6, and the first conductive layer 7 disposed on the surface of the second conductive layer 7. And the conductive layer 3. The melting point of the second conductive layer 7 is higher than the melting point of the first conductive layer 3.

  FIG. 2 is a sectional view showing conductive particles contained in a conductive particle material according to a second embodiment of the present invention.

  The conductive particles 11 shown in FIG. 2 include base particles 12 and a first conductive layer 13 disposed on the surface of the base particles 12. The conductive particles 11 are coated particles in which the surface of the base particles 12 is coated with the first conductive layer 13. The melting point of the first conductive layer 13 is 450 ° C. or less.

  The base particles are base particles having no conductive layer, or base particles having a base particle main body and a second conductive layer disposed on the surface of the base particle main body. Is preferred. The base particles may be base particles having no conductive layer, and may be base particles having a base particle body and a second conductive layer disposed on the surface of the base particle body. There may be.

  Examples of the base particles having no conductive layer and the base particle main body include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The base particles having no conductive layer and the base particle main body may be inorganic particles other than resin particles and metal particles, organic-inorganic hybrid particles, or metal particles. The base particles having no conductive layer and the base particle main body are preferably base particles excluding metal particles, respectively, and are resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles. preferable.

  The base particles having no conductive layer and the base particle body are preferably resin particles formed of a resin. When connecting between electrodes using conductive particles, the conductive particles are compressed by compressing them after placing the conductive particles between the electrodes. When the base particles having no conductive layer and the base particle body are resin particles, the conductive particles are easily deformed at the time of the pressure bonding, and the contact area between the conductive particles and the electrode is increased. For this reason, the conduction reliability between the electrodes is further improved.

  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, polyethylene terephthalate, Polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamide Bromide, polyether ether ketone, polyether sulfone, divinyl benzene polymer, and divinylbenzene copolymer, and the like. Examples of the divinylbenzene-based copolymer include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylate copolymer. Since the hardness of the resin particles can be easily controlled to a suitable range, the resin for forming the resin particles is prepared by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. It is preferred that they are united.

  When the resin particles are obtained by polymerizing a monomer having an ethylenically unsaturated group, the monomer having an ethylenically unsaturated group includes a non-crosslinkable monomer and a crosslinkable monomer. And a dimer.

  Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; carboxyl-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; methyl ( (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 and propyl vinyl ether; vinyl acids 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 tetramethylolmethanetetra (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, trimethylolpropanetri (meth) acrylate, and dipentane. 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 and 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 the method include a method of performing suspension polymerization in the presence of a radical polymerization initiator, and a method of performing polymerization by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  When the base particles are inorganic particles other than metals or organic-inorganic hybrid particles, examples of the inorganic substance for forming the base particles include silica and carbon black. The particles formed of the silica are not particularly limited. For example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysil groups to form crosslinked polymer particles, baking is performed as necessary. Particles obtained by performing the method are exemplified. Examples of the organic-inorganic hybrid particles include, for example, organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

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

  The conductive particles may have a single conductive layer (first conductive layer). The conductive particles may have a plurality of conductive layers (first and second conductive layers). That is, in the conductive particles, two or more conductive layers may be stacked. Further, the second conductive layer having a melting point higher than the melting point of the first conductive layer may be a plurality of layers.

  The first conductive layer is a low melting point metal layer having a melting point of 450 ° C. or less. The low melting point metal layer is a layer containing a low melting point metal. The low melting point metal is a metal having a melting point of 450 ° C. or less. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. Further, the low melting point metal layer preferably contains tin. In 100% by weight of the metal contained in the low melting point metal layer, the content of tin is preferably at least 30% by weight, more preferably at least 40% by weight, further preferably at least 70% by weight, particularly preferably at least 90% by weight. . When the content of tin in the low melting point metal layer is not less than the lower limit, the connection reliability between the low melting point metal layer and the electrode is further enhanced. The tin content was measured using a high-frequency inductively coupled plasma emission spectrometer ("ICP-AES" manufactured by Horiba, Ltd.) or an X-ray fluorescence analyzer ("EDX-800HS" manufactured by Shimadzu Corporation). It can be measured.

  When the low-melting-point metal layer is present, the low-melting-point metal layer melts and bonds to the electrodes, and the low-melting-point metal layer conducts between the electrodes. For example, since the low-melting-point metal layer and the electrode are likely to make surface contact instead of point contact, the connection resistance is reduced. In addition, the use of the conductive particles having the low-melting-point metal layer increases the bonding strength between the low-melting-point metal layer and the electrode. Effectively increases.

  The low melting point metal constituting the low melting point metal layer is not particularly limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include a tin-silver alloy, a tin-copper alloy, a tin-silver-copper alloy, a tin-bismuth alloy, a tin-zinc alloy, and a tin-indium alloy. Among them, the low melting point metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, or tin-indium alloy because of its excellent wettability to the electrode. More preferably, they are a tin-bismuth alloy and a tin-indium alloy.

  Further, the low melting point metal layer (the first conductive layer) is preferably a solder layer. The material constituting the solder layer is not particularly limited, but is preferably a filler material having a liquidus of 450 ° C. or lower based on JIS Z3001: welding terminology. Examples of the composition of the solder layer include a metal composition containing zinc, gold, lead, copper, tin, bismuth, indium, and the like. Among them, tin-indium (117 ° C eutectic) or tin-bismuth (139 ° C eutectic), which is low in melting point and free of lead, is preferable. That is, the solder layer preferably does not contain lead, and is preferably a solder layer containing tin and indium, or a solder layer containing tin and bismuth.

  In order to further increase the bonding strength between the low-melting metal layer and the electrode, the low-melting metal layer is formed of nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, and bismuth. , Manganese, chromium, molybdenum, palladium and the like. From the viewpoint of further increasing the bonding strength between the low melting point metal layer and the electrode, the low melting point metal preferably contains nickel, copper, antimony, aluminum or zinc. From the viewpoint of further increasing the bonding strength between the low melting point metal layer and the electrode, the content of these metals for increasing the bonding strength is preferably at least 0.0001% by weight in 100% by weight of the low melting point metal layer, It is preferably at most 1% by weight.

  The melting point of the second conductive layer is higher than the melting point of the first conductive layer. The melting point of the second conductive layer is preferably higher than 160 ° C, more preferably higher than 300 ° C, still more preferably higher than 400 ° C, still more preferably higher than 450 ° C, particularly preferably higher than 500 ° C, Most preferably above 600 ° C. Since the first conductive layer has a low melting point, it melts at the time of conductive connection. It is preferable that the second conductive layer does not melt at the time of conductive connection. The conductive particles are preferably used by melting the first conductive layer, and are preferably used by melting the first conductive layer and without melting the second conductive layer. Since the melting point of the second conductive layer is higher than the melting point of the first conductive layer, only the first conductive layer is melted without melting the second conductive layer during conductive connection. be able to.

  The absolute value of the difference between the melting point of the first conductive layer and the melting point of the second conductive layer exceeds 0 ° C., preferably 5 ° C. or higher, more preferably 10 ° C. or higher, and still more preferably 30 ° C. or higher. It is particularly preferably at least 50 ° C, most preferably at least 100 ° C.

  The second conductive layer preferably contains a metal. The metal forming the second conductive layer is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, cadmium, and alloys thereof. Further, tin-doped indium oxide (ITO) may be used as the metal. One of the above metals may be used alone, or two or more thereof may be used in combination.

  The second conductive layer is preferably a nickel layer, a palladium layer, a copper layer or a gold layer, more preferably a nickel layer or a gold layer, and further preferably a copper layer. The conductive particles preferably have a nickel layer, a palladium layer, a copper layer or a gold layer, more preferably have a nickel layer or a gold layer, and still more preferably have a copper layer. By using the conductive particles having these preferable conductive layers for the connection between the electrodes, the connection resistance between the electrodes is further reduced. In addition, a low melting point metal layer can be more easily formed on the surface of these preferred conductive layers.

  In the conductive particle material, the average particle size 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, further preferably 15 μm or less, particularly preferably It is 10 μm or less. From the viewpoint of further increasing the connection reliability of the connection structure when subjected to the heat history, the average particle diameter of the conductive particles is particularly preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and 4 μm or less. Most preferably.

  The “average particle diameter” of the conductive particles indicates a number average particle diameter. The average particle diameter of the conductive particles can be determined by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

  The average thickness of the first conductive layer is preferably 0.05 μm or more, more preferably 0.5 μm or more, preferably 10 μm or less, more preferably 5 μm or less. When the thickness of the first conductive layer is equal to or more than the lower limit and equal to or less than the upper limit, the first conductive layer sufficiently wets and spreads on the electrode at the time of pressure bonding, so that sufficient conductivity is obtained. The average thickness of the first conductive layer is an average of the thickness of the first conductive layer in a plurality of conductive particles included in the conductive particle material.

  The average thickness of the second conductive layer is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. When the thickness of the second conductive layer is equal to or greater than the lower limit and equal to or less than the upper limit, the connection resistance between the electrodes is further reduced. The average thickness of the second conductive layer is an average of the thickness of the second conductive layer in a plurality of conductive particles included in the conductive particle material.

(Conductive material)
The conductive material according to the present invention includes the above-described conductive particle material and a binder resin. Therefore, the conductive material according to the present invention includes a plurality of conductive particles. The conductive material is preferably an anisotropic conductive material.

  The binder resin is not particularly limited. In general, an insulating resin is used as the binder resin. Examples of the binder resin include a vinyl resin, a thermoplastic resin, a curable resin, a thermoplastic block copolymer, and an elastomer. The binder resin preferably contains a thermosetting component, and more preferably contains a thermosetting compound and a thermosetting agent. As the binder resin, only one kind may be used, or two or more kinds may be used in combination.

  Examples of the vinyl resin include a vinyl acetate resin, an acrylic resin, and a styrene resin. Examples of the thermoplastic resin include a polyolefin resin, an ethylene-vinyl acetate copolymer, and a polyamide resin. 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 styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, and styrene-isoprene. -Hydrogenated products of styrene block copolymers. Examples of the elastomer include a styrene-butadiene copolymer rubber and an acrylonitrile-styrene block copolymer rubber.

  The conductive material may be, for example, a filler, a bulking agent, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, and a heat stabilizer, in addition to the conductive particles with insulating particles and the binder resin. It may contain various additives such as an agent, a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant.

  A method for dispersing the conductive particles in the binder resin may be a conventionally known dispersion method, and is not particularly limited. Examples of a method of dispersing the conductive particles in the binder resin include, for example, a method of adding the conductive particles to the binder resin, kneading and dispersing the mixture with a planetary mixer, or dispersing the conductive particles in water. Or after uniformly dispersed in an organic solvent using a homogenizer or the like, added to the binder resin, a method of kneading and dispersing with a planetary mixer or the like, and diluting the binder resin with water or an organic solvent or the like Thereafter, a method of adding the above-mentioned conductive particles, kneading and dispersing the mixture with a planetary mixer, or the like can be used.

  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 not containing a conductive particle material may be laminated on the conductive film containing a conductive particle material. 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 at least 10% by weight, more preferably at least 30% by weight, further preferably at least 50% by weight, particularly preferably at least 70% by weight, and preferably at least 99.99%. % By weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is equal to or more than the lower limit and equal to or less than the upper limit, the conductive particles are more efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is higher. Become.

  In 100% by weight of the conductive material, the content of the conductive particles (that is, the content of the conductive particle material) is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, and still more preferably 1% by weight. %, Preferably 40% by weight or less, more preferably 30% by weight or less, further preferably 20% by weight or less, particularly preferably 15% by weight or less. It is particularly preferable that the content of the conductive particles is 1% by weight or more and 20% by weight or less in 100% by weight of the conductive material. When the content of the conductive particles is equal to or more than the lower limit and equal to or less than the upper limit, the conductive particles can be easily arranged between upper and lower electrodes to be connected. Further, it becomes difficult to electrically connect adjacent electrodes that should not be connected via a plurality of conductive particles. That is, a short circuit between adjacent electrodes can be further prevented.

(Connection structure)
A connection structure can be obtained by connecting a connection target member using a conductive material (such as an anisotropic conductive material) containing the above-described conductive particle material and a binder resin.

  The connection structure includes 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. Is preferably a connection structure formed of a conductive material containing the above-described conductive particle material and a binder resin.

  FIG. 3 is a front cross-sectional view schematically showing a connection structure using the conductive particles 1 shown in FIG.

  The connection structure 51 shown in FIG. 3 includes a first connection target member 52, a second connection target member 53, and a connection connecting the first connection target member 52 and the second connection target member 53. A portion 54. The connection portion 54 is formed of a conductive material including a conductive particle material containing a plurality of conductive particles 1 and a binder resin. Instead of the conductive particles 1, other conductive particles such as the conductive particles 11 may be used.

  The first connection target 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 52a and the second electrode 53a 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 first and second electrodes 52a and 53a have a length direction and a width direction, respectively, and FIG. 3 shows a cross section in the length direction of the first and second electrodes 52a and 53a. .

  The connection structure 51 shown in FIG. 3 can be obtained as follows, for example, through the respective steps shown in FIGS.

  First, a first connection target member 52 having a plurality of first electrodes 52a on its surface is prepared. Next, as shown in FIG. 4A, the conductive material (such as an anisotropic conductive material) is disposed on the surface of the first member 52 to be connected, and the surface of the first member 52 to be connected is Then, a conductive material layer 54A (such as an anisotropic conductive material layer) is formed. At this time, a conductive material is disposed in the first region R1, which is a partial region on the first electrode 52a, to form a conductive material layer 54A. The region where the conductive material layer 54A is initially arranged is the first region R1.

  Next, a second connection target member 53 having a plurality of second electrodes 53a on its surface is prepared. As shown in FIG. 4B, a second connection target member 53 is stacked on the surface of the conductive material layer 54A opposite to the first connection target member 52 side. The second connection target member 53 is stacked such that the first electrode 52a and the second electrode 53a face each other. At the time of laminating the second connection target member 53, the conductive material layer 54A is made to spread in the directions indicated by arrows Y1 and Y2 in the second region R2 around the first region R1. That is, the conductive material layer 54A flows to the second region R2 around the first region. At this time, relatively large conductive particles 1 are likely to be sandwiched between the first electrode 52a and the second electrode 53a in the first region R1 or in the vicinity of the first region R1.

  Thereafter, as shown in FIG. 4C, in the laminated body in which the first connection target member 52, the conductive material layer 54A, and the second connection target member 53 are stacked, the conductive material layer 54A is heated and cured. Let it. When the conductive material layer 54A is heated, the first conductive layer 3 is melted. It is preferable to apply pressure when heating the conductive material layer 54A. By melting the first conductive layer 3 of the relatively large conductive particles 1 sandwiching the first electrode 52a and the second electrode 53a, the distance between the first and second electrodes 52a and 53a is increased. Becomes narrower. For example, the distance between the first and second electrodes 52a and 53a is reduced by the thickness of the first conductive layer 3. Also, as the distance between the first and second electrodes 52a and 53a becomes smaller, the conductive material layer 54A moves in the directions indicated by arrows Y1 and Y2. That is, the conductive material layer 54A flows to the second region R2 around the first region R1. As the particle size of the conductive particles 1 increases, the conductive particles 1 are more likely to be sandwiched between the first and second electrodes 52a and 53a in the first region R1 or in the vicinity of the first region R1. As the particle size of the conductive particles 1 is smaller, the conductive particles 1 are more likely to be sandwiched between the first and second electrodes 52a and 53a in the second region R2.

  Further, as the particle diameter of the base particles 2 is more uniform, the plurality of base particles 2 are more likely to contact the first and second electrodes 52a and 53a, and the connection resistance between the electrodes is further reduced. The spacing between the electrodes becomes uniform. On the other hand, as the particle diameter of the base particles becomes more uneven, the number of base particles that do not contact the first and second electrodes increases, the connection resistance between the electrodes increases, and the gap between the electrodes becomes more uneven. become.

  In addition, by using the conductive particles having the second conductive layer 7, the second conductive layer 7 of the plurality of base particles 2 is easily brought into contact with the first and second electrodes 52a and 53a. On the other hand, when the melting point of the first conductive layer is high and the first conductive layer does not melt, the distance between the first and second electrodes is regulated by the relatively large conductive particles, so that the first conductive layer has a relatively small melting point. A portion where the conductive particles do not contact the electrodes or where the first and second electrodes are connected by relatively large conductive particles, and a portion where the first and second electrodes are connected by relatively small conductive particles. In some cases, the distance between the electrodes is different from that of the connected portion, and the connection target member may be curved.

  As described above, the connection portion 54 is formed by heating and curing the conductive material layer 54A using the conductive material. The connection part 54 connects the first connection target member 52 and the second connection target member 53. Further, the first electrode 52a and the second electrode 53a are electrically connected by the conductive particles 1. Thus, the connection structure 51 can be obtained.

  Further, as shown in FIG. 3, in the connection structure 51, the first conductive layer 3 in the conductive particles 1 is melted by heating and pressurizing the laminate, and then the melted first conductive layer portion Are sufficiently in contact with the first and second electrodes 52a and 53a. That is, by using the conductive particles 1 having the first conductive layer 3 having a low melting point, the first conductive layer 3 is melted to wet and spread the surfaces of the first and second electrodes 52a and 53a. Thus, the contact area between the first conductive layer 3 and the first and second electrodes 52a and 53a can be increased. When the conductive particles 1 are used, the second conductive layer 7 can be brought into contact with the first electrode 52a and the second electrode 53a. When the conductivity of the second conductive layer 7 is higher than the conductivity of the first conductive layer 3, the connection resistance can be further reduced. In the case where the conductive particles including the second conductive layer are used, in the connection structure, the second conductive layer is preferably in contact with the first electrode and the second electrode.

  The heating temperature when the conductive material layer 54A is cured by heating is preferably 140 ° C. or higher, preferably 450 ° C. or lower, more preferably 250 ° C. or lower, and further preferably 200 ° C. or lower. Note that before the conductive material layer 54A is completely cured by heating, the curing of the conductive material layer 54A may be advanced so that the conductive material layer 54A is not completely cured. For example, the conductive material layer 54A may be in the B-stage state.

  The heating temperature when the conductive material layer 54A is cured (finally cured) by heating is preferably a temperature at which the first conductive layer 3 is melted. The heating temperature when the conductive material layer 54A is cured by heating is preferably a temperature at which the base particles, the base particle main body, and the second conductive layer do not melt.

  The connection structure 51 illustrated in FIG. 3 includes a first region R1 that is a part of a region on the first electrode 52a, and a conductive material disposed on the first region R1 to form a conductive material layer 54A. This is obtained by forming the connection portion 54 by wet-spreading the conductive material layer 54A in the surrounding second region R2. The amount of the first conductive layer 3 in the conductive particles 1 located in the first region R1 is larger than the amount of the first conductive layer 3 in the conductive particles 1 located in the second region R2. In other words, in the connection structure 51, the amount of the first conductive layer 3 in the conductive particles 1 in the region where the conductive material layer is initially arranged is different from that in the region where the conductive material layer is wetted and spread from the region where the conductive material layer is initially arranged. Larger than the amount of the first conductive layer 3 in the conductive particles 1.

  After forming a conductive material layer 54A by disposing a conductive material including a plurality of conductive particles 1 in a first region R1, which is a partial region on the first electrode 52a (see FIG. a)), the connection portion 54 is formed by wet-spreading the conductive material layer 54A in the second region R2 around the first region R1 to form a connection portion 54 per unit area in the first region R1. The number of the conductive particles 1 and the number of the conductive particles 1 per unit area in the second region R2 can be made uniform (for example, the state shown in FIG. 5B).

  On the other hand, when the conventional conductive particles are used, a large number of conductive particles are arranged in the first region as shown in FIG. 6A, or as shown in FIG. Many conductive particles are arranged in the second region. 6 (a) and 6 (b) are plan views after a connection structure is obtained using conventional conductive particles instead of the conductive particles 1, and correspond to FIG. 5 (b). It is.

The average number A of the conductive particles existing in the area having a size of 0.1 mm ² in the first region R1 is the conductive particles existing in the region having a size of 0.2 mm ² in the second region R2. Is preferably 0.25 or more, more preferably 0.3 or more, preferably 0.65 or less, more preferably 0.6 or less.

  It is preferable that the first connection target member has a plurality of first electrodes on its surface. The second connection target member preferably has a plurality of second electrodes on the surface. It is preferable that the plurality of first electrodes and the plurality of second electrodes are electrically connected by the conductive particles.

  Preferably, the first electrode has a length direction and a width direction. Preferably, the second electrode has a length direction and a width direction. The aspect ratio of the first electrode and the second electrode is preferably 5 or more, more preferably 10 or more, preferably 100 or less, more preferably 50 or less. It is preferable that the first electrode and the second electrode are electrically connected to each other by the conductive particles contained in the conductive particle material so that the lengthwise directions are aligned. The aspect ratio is “aspect ratio = dimension in length direction / dimension in width direction”.

  The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include electronic components such as semiconductor chips, capacitors and diodes, and electronic components such as circuit boards such as printed boards, flexible printed boards and glass boards. Can be The conductive material is preferably a conductive material used for connecting electronic components. It is preferable that the conductive material is a liquid and is applied to the upper surface of the connection target member in a liquid state. Preferably, the connection target member is an electronic component.

  Examples of the electrodes 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 member to be connected is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. When the electrode is an aluminum electrode, the electrode may be an electrode formed only of aluminum, or may be an electrode in which an aluminum layer is laminated on a surface of a metal oxide layer. Examples of the material of 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)
Electroless nickel plating of divinylbenzene resin particles (“Micropearl SP-210” manufactured by Sekisui Chemical Co., Ltd., average particle diameter 10 μm, softening point 330 ° C.), and nickel plating 0.1 μm thick on the surface of the resin particles A layer was formed. Next, the resin particles on which the base nickel plating layer was formed were subjected to electrolytic copper plating to form a copper layer having an average thickness of 2 μm, thereby obtaining base particles. The base particles have resin particles and a copper layer. The average particle diameter of the obtained base particles was 14 μm, and the CV value was 5%.

  Next, using an electroplating solution containing tin and bismuth, electroplating is performed, and the initial stage, the middle stage, and the late stage of electroplating are divided into a plurality of times, and the obtained conductive particles are taken out. A solder layer having an average thickness of 2 μm was formed. In this manner, a copper layer is formed on the surface of the resin particles, and a solder layer (tin: bismuth = 43% by weight: 57% by weight, melting point: 139 ° C.) is formed on the surface of the copper layer. A conductive particle material containing conductive particles (resin core solder-coated particles) was prepared. The average particle diameter of the obtained conductive particles was 20 μm, and the CV value was 12%.

  The obtained conductive particles have resin particles as the base particle main body, have a copper layer as the second conductive layer, and have a solder layer as the first conductive layer.

(Example 2 , Reference Example 3, Example 4, and Comparative Example 1)
Example 1 was the same as Example 1 except that the average particle diameter and CV value of the base particles (including the resin particles and the copper layer) and the average particle diameter and CV value of the conductive particles were set as shown in Table 1 below. Similarly, a conductive particle material was obtained.

  The CV value of the base particles was adjusted by changing the CV value of the resin particles. The CV value of the conductive particles was adjusted by selecting conductive particles having a predetermined size.

(Comparative Example 2)
The average particle diameter and CV value of the base particles (including the resin particles and the copper layer) and the CV value of the conductive particles were set as shown in Table 1 below, and the solder layer in the conductive particles was made of nickel. A conductive particle material was obtained in the same manner as in Example 1 except that the layer was changed to a layer (melting point: 1455 ° C.).

(Example 5)
As the base particles obtained in Example 1, base particles having an average particle diameter of 14 μm and a CV value of 5% were prepared.

  Next, electroplating is performed using an electroplating solution containing tin and bismuth, and conductive particles having an average thickness of the solder layer of 2 μm, conductive particles having a solder layer thickness of 3 μm, Conductive particles each having a layer thickness of 4 μm were prepared and mixed. In this manner, a copper layer is formed on the surface of the resin particles, and a solder layer (tin: bismuth = 43% by weight: 57% by weight, melting point: 139 ° C.) is formed on the surface of the copper layer. A conductive particle material containing conductive particles (resin core solder-coated particles) was prepared. The average particle diameter of the obtained conductive particles was 20 μm, and the CV value was 12%.

(Example 6)
As the base particles obtained in Example 1, base particles having an average particle diameter of 14 μm and a CV value of 5% were prepared.

  In the theta composer, solder particles having a particle diameter of 1 μm are added at the beginning of the production to form a solder layer, and solder particles having a particle diameter of 3 μm are formed at a later stage of the production to form a solder layer. By adding, the solder layer was formed so as to have a non-uniform thickness, and a solder layer having an average thickness of 2 μm was formed. In this manner, a copper layer is formed on the surface of the resin particles, and a solder layer (tin: bismuth = 43% by weight: 57% by weight, melting point: 139 ° C.) is formed on the surface of the copper layer. A conductive particle material containing conductive particles (resin core solder-coated particles) was prepared. The average particle diameter of the obtained conductive particles was 21 μm, and the CV value was 15%.

(Example 7)
The surface of a divinylbenzene copolymer resin particle having a particle diameter of 3.0 μm (“Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) was coated with an inorganic shell (250 nm in thickness) using a condensation reaction by a sol-gel reaction. Core-shell type organic-inorganic hybrid particles (base particles) were prepared. The average particle diameter of the obtained organic-inorganic hybrid particles was 14 μm, and the CV value was 5%.

  A copper layer was formed on the surface of the resin particles in the same manner as in Example 1 except that the resin particles were changed to the organic-inorganic hybrid particles, and a solder layer (tin: bismuth) was formed on the surface of the copper layer. (43% by weight: 57% by weight, melting point: 139 ° C.) to prepare a conductive particle material containing conductive particles (resin core solder-coated particles). The average particle diameter of the obtained conductive particles was 20 μm, and the CV value was 12%.

(Evaluation)
(1) Preparation of anisotropic conductive material 30 parts by weight of an epoxy compound (“YL980” manufactured by Mitsubishi Chemical Corporation) and 10 parts by weight of an imidazole compound (“2P-4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a thermosetting agent 15 parts by weight of an epoxy acrylate (“EBECRYL3702” manufactured by Daicel Scitech) as a photocurable compound and 0.3 parts by weight of an acylphosphine oxide compound (“DAROCUR TPO” manufactured by Ciba Japan) as a photopolymerization initiator And 1 part by weight of a silane coupling agent (“KBE-403” manufactured by Shin-Etsu Chemical Co., Ltd.), 20 parts by weight of silica having an average particle diameter of 0.25 μm, and 2 parts by weight of glutaric acid as a flux Of the anisotropic conductive paste from which the obtained conductive particles can be obtained, and the content thereof becomes 30% by weight. Then, the mixture was stirred at 2,000 rpm for 5 minutes using a planetary stirrer to obtain an anisotropic conductive paste.

(2) Preparation of connection structure A glass epoxy substrate having a plurality of first electrodes (L / S of 100 μm / 100 μm, an aspect ratio of one electrode of 20 and a thickness of 20 μm, and a gold-plated Cu electrode) on the surface ( A first connection target member) was prepared.

  In addition, a flexible printed board (second connection target member) having a plurality of second electrodes (L / S of 100 μm / 100 μm, aspect ratio of one electrode is 20 μm, thickness of 20 μm, and gold-plated Cu electrodes) on the surface Was prepared.

  While moving the dispenser linearly in a direction perpendicular to the length direction of the first electrode at the central portion in the length direction of the first electrode (the length direction of one electrode), the glass epoxy The obtained anisotropic conductive paste was applied on a substrate to form an anisotropic conductive material layer. That is, the dispenser was moved from one edge of the electrode pattern to the other edge to form an anisotropic conductive material layer on the plurality of first electrodes.

Next, ultraviolet light of 420 nm was applied to the anisotropic conductive material layer using an ultraviolet irradiation lamp so that the light irradiation energy became 70 mJ / cm ² .

  Next, the flexible printed circuit board was laminated on the surface of the anisotropic conductive material layer opposite to the glass epoxy substrate side with the first electrode and the second electrode facing each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive material layer becomes 185 ° C., a pressure heating head is placed on the surface of the glass substrate, and a pressure of 1 MPa is applied thereto to apply a pressure of 1 MPa. Was cured at 185 ° C. to obtain a connection structure.

(3) Evaluation of State of Conductive Connection The region where the anisotropic conductive material layer was initially arranged is defined as a first region which is a partial region on the first electrode, and a difference around the first region is determined. The region where the anisotropic conductive material layer spreads is referred to as a second region.

The flexible printed circuit board of the connection structure was peeled off, and the average number A of the conductive particles present in the area having a size of 0.1 mm ² in the first area was observed from the upper side of the glass epoxy board. The average number B of the conductive particles existing in the area having a size of 0.2 mm ² in the area ² was measured. The state of the conductive connection was determined based on the following criteria.

[Evaluation criteria for conductive connection state]
：: The ratio of the average number A to the average number B is 0.3 or more and 0.6 or less Δ: The ratio of the average number A to the average number B is 0.2 or more, less than 0.3 or more than 0.6, and 0 .65 or less ×: ratio of average number A to average number B is less than 0.2 or more than 0.65

  The results are shown in Table 1 below.

In the above (3) Evaluation of the state of the conductive connection in Examples , Reference Examples and Comparative Examples, the evaluation results in the case where the anisotropic conductive material layer was light-cured and then thermally cured were shown. Even when the isotropic conductive material was cured in one step, the evaluation results of the state of the conductive connection showed the same tendency.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle 2 ... Base particle 3 ... 1st conductive layer 6 ... Base particle main body 7 ... 2nd conductive layer 11 ... Conductive particle 12 ... Base particle 13 ... 1st conductive layer 51 ... Connection Structure 52 first member to be connected 52a first electrode 53 second member to be connected 53a second electrode 54 connection part 54A conductive material layer R1 first region R2 second region

Claims (7)

A conductive particle material including a plurality of conductive particles including a base particle and a first conductive layer disposed on a surface of the base particle,
The first conductive layer has a melting point of 450 ° C. or less;
The average particle diameter of the conductive particles is 100 μm or less,
The CV value of the particle size of the conductive particles is larger than the CV value of the particle size of the base particles,
A conductive particle material, wherein an absolute value of a difference between a CV value of a particle size of the conductive particles and a CV value of a particle size of the base particles is 6 % or more and 10% or less. The base particles have a base particle body and a second conductive layer disposed on a surface of the base particle body,
The conductive particle material according to claim 1, wherein the melting point of the second conductive layer is higher than the melting point of the first conductive layer.   The conductive particle material according to claim 2, wherein the melting point of the second conductive layer exceeds 450 ° C.   The conductive particle material according to any one of claims 1 to 3, which is dispersed in a binder resin and used as a conductive material.   A conductive material comprising the conductive particle material according to claim 1 and a binder resin. A first connection target member having a first electrode on its surface;
A second member to be connected having a second electrode on its surface;
A connection portion connecting the first connection target member and the second connection target member,
The connection portion is formed of a conductive material including the conductive particle material and the binder resin according to any one of claims 1 to 4,
A connection structure, wherein the first electrode and the second electrode are electrically connected by the conductive particles included in the conductive particle material. A conductive material layer comprising a conductive material containing the conductive particle material according to any one of claims 1 to 4 and a binder resin disposed on a first connection target member having a first electrode on a surface thereof. Forming a;
Stacking a second member to be connected having a second electrode on the surface of the conductive material layer opposite to the first member to be connected;
Heating and curing the conductive material layer to form a connection portion, and connecting the first connection target member and the second connection target member by the connection portion,
A method for manufacturing a connection structure, wherein a connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles included in the conductive particle material is obtained.

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