JP5375374B2 - Circuit connection material and circuit connection structure - Google Patents

Description

  The present invention relates to a circuit connection material and a circuit connection structure.

  Conventionally, anisotropic conductive adhesive films are known as circuit connection materials for heating and pressurizing opposing circuits to electrically connect electrodes in the pressurizing direction, for example, epoxy adhesives and acrylic adhesives. An anisotropic conductive adhesive film in which conductive particles are dispersed in an agent is known. Such an anisotropic conductive adhesive film is mainly composed of a TCP (Tape Carrier Package) or COF (Chip On Flex) on which a semiconductor for driving a liquid crystal display (hereinafter referred to as “LCD”) is mounted and the LCD panel. Widely used for electrical connection or electrical connection between a TCP or COF and a printed wiring board.

  Recently, even when a semiconductor is directly mounted on an LCD panel or a printed wiring board face down, flip chip mounting, which is advantageous for thinning and narrow pitch connection, has been adopted instead of the conventional wire bonding method. Also in this flip chip mounting, an anisotropic conductive adhesive film is used as a circuit connecting material (for example, see Patent Documents 1 to 4).

  By the way, in recent years, with the increase in COF and fine pitch of LCD modules, there is a problem that a short circuit occurs between adjacent circuit electrodes when connecting using a circuit connecting material. As a countermeasure, a technique is known in which insulating particles are dispersed in an adhesive component to prevent a short circuit (see, for example, Patent Documents 5 to 9).

  When the insulating particles are dispersed in the adhesive component, there is a tendency that a decrease in the adhesive strength of the circuit connection material or peeling at the interface between the substrate and the circuit connection portion becomes a problem. For this reason, in order for the substrate to adhere to a wiring member made of an insulating organic substance or glass, or a wiring member made of at least one part of at least one of silicon nitride, silicone resin, polyimide resin, etc., the circuit connecting material is made of silicone. A method for improving adhesion by incorporating particles (for example, see Patent Document 10) and a method for dispersing rubber particles in a circuit connecting material in order to reduce internal stress based on a difference in coefficient of thermal expansion after adhesion are known. (For example, refer to Patent Document 11).

  Furthermore, as a means for preventing a short circuit between circuit electrodes, a method is known in which conductive particles whose surfaces are coated with an insulating film are dispersed in a circuit connecting material (see, for example, Patent Documents 12 and 13).

JP 59-120436 A JP-A-60-191228 JP-A-1-251787 JP-A-7-90237 JP 51-20941 A JP-A-3-29207 JP-A-4-174980 Japanese Patent No. 3048197 Japanese Patent No. 3477367 International Publication WO01 / 014484 Pamphlet JP 2001-323249 A Japanese Patent No. 2779409 Japanese Patent Laid-Open No. 2001-195921

  In recent years, an indium-zinc oxide (IZO) electrode has been used instead of an indium-tin oxide (ITO) electrode as a circuit electrode of a glass substrate from the viewpoint of reducing costs. Yes. For the IZO electrode, from the viewpoint of reducing connection resistance, it has been studied to disperse conductive particles covered with an outermost layer containing Ni, Ni alloy, Ni oxide, or the like in a circuit connection material. However, in this case, depending on the average particle diameter of the conductive particles and the type of adhesive, there is a problem that the outermost layer Ni of the conductive particles influences and the pot life of the circuit connecting material is reduced. As described above, the conventional circuit connection material in which the conductive particles are dispersed has a problem that it is difficult to sufficiently reduce the connection resistance between the circuit electrodes and to suppress the decrease in pot life.

  Therefore, the present invention can reduce the connection resistance between the circuit electrodes without depending on the type of the circuit electrodes such as the ITO electrode and the IZO electrode as compared with the conventional circuit connection material, and lower the pot life. An object of the present invention is to provide a circuit connection material and a circuit connection structure capable of suppressing the above.

  The present invention is a circuit connecting material for electrically connecting circuit electrodes interposed between opposing circuit electrodes, and at least one selected from the group consisting of an adhesive component, Ni, Ni alloy, and Ni oxide A plurality of protrusions on the surface of the outermost layer of the first conductive particles, the first conductive particles covered with the outermost layer containing seeds, and the second conductive particles covered with the outermost layer containing Au. A circuit connecting material is provided in which a ratio of the number of second conductive particles to the number of first conductive particles per unit volume in the circuit connecting material is 0.4 to 3.

  Further, the present invention is a circuit connecting material for electrically connecting circuit electrodes interposed between opposing circuit electrodes, and is covered with an outermost layer containing an adhesive component and a metal having a Vickers hardness of 300 Hv or more. The first conductive particles and the second conductive particles covered with the outermost layer containing Au, and a plurality of protrusions are formed on the surface of the outermost layer of the first conductive particles, Provided is a circuit connection material in which the ratio of the number of second conductive particles to the number of first conductive particles per unit volume in the connection material is 0.4 to 3.

  According to such a circuit connection material, it is possible to reduce the connection resistance between the circuit electrodes without depending on the type of the circuit electrode, and it is possible to suppress a decrease in pot life.

  The ratio of the content of the second conductive particles to the content of the first conductive particles in the circuit connection material is preferably 0.4 to 3 in volume ratio. In this case, it is possible to further reduce the connection resistance between the circuit electrodes without depending on the type of the circuit electrode, and it is possible to further suppress the decrease in pot life.

  The height of the protrusions of the first conductive particles is preferably 50 to 500 nm, and the distance between adjacent protrusions is preferably 1000 nm or less.

  The average particle diameter of at least one of the first conductive particles and the second conductive particles is preferably 1 to 10 μm. In this case, a short circuit between adjacent circuit electrodes can be suppressed.

  According to the present invention, the first circuit member having the first circuit electrode and the second circuit member having the second circuit electrode are in a state where the first circuit electrode and the second circuit electrode face each other. The first circuit electrode and the second circuit electrode are electrically connected by placing the circuit connection material between the first circuit electrode and the second circuit electrode and applying heat and pressure. Provided is a circuit connection structure.

  In the circuit connection structure of the present invention, by using the circuit connection material, it is possible to reduce the connection resistance between the circuit electrodes without depending on the type of the circuit electrodes, and to reduce the pot life. It is possible to suppress.

  In the circuit connection structure of the present invention, it is preferable that at least one of the first circuit electrode and the second circuit electrode includes at least one of indium-tin oxide (ITO) and indium-zinc oxide (IZO). . In this case, the electrical connection between the circuit electrodes can be remarkably improved.

  According to the present invention, compared with conventional circuit connection materials, it is possible to reduce the connection resistance between circuit electrodes without depending on the type of circuit electrodes such as ITO electrodes and IZO electrodes, and to reduce pot life. It is possible to provide a circuit connection material and a circuit connection structure for electric / electronic that are excellent in connection reliability.

The schematic cross section which shows the circuit connection material which concerns on one Embodiment of this invention. The schematic cross section which shows the electrically-conductive particle contained in the circuit connection material which concerns on one Embodiment of this invention. 1 is a schematic cross-sectional view showing a circuit connection structure according to an embodiment of the present invention. Process sectional drawing which shows typically the manufacturing method of the circuit connection structure which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary.

<Circuit connection material>
First, the circuit connection material 1 of this embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing a circuit connection material according to an embodiment of the present invention. The circuit connecting material 1 contains an adhesive component (insulating substance) 11a, first conductive particles 12a, and second conductive particles 12b as constituent components.

(Adhesive component)
The adhesive component 11a contains, for example, (a) a curing agent that generates free radicals by heating or light (hereinafter sometimes referred to as “(a) free radical generator”) and (b) a radical polymerizable substance.

  (A) The free radical generator is appropriately selected depending on the intended connection temperature, connection time, pot life, etc., and heating and light such as a peroxide compound (organic peroxide), an azo compound or a photoinitiator. A compound that generates an active radical by at least one treatment of irradiation is used.

  From the viewpoint of achieving both high reactivity and excellent pot life, the organic peroxide has a half-life temperature of 40 ° C or higher and a half-life temperature of 1 minute is 180 ° C or lower. More preferably, the temperature with a half-life of 10 hours is 60 ° C. or more, and the temperature with a half-life of 1 minute is 170 ° C. or less. The organic peroxide preferably has a chlorine ion or organic acid content of 5000 ppm or less in order to prevent corrosion of the circuit electrode of the circuit member, and further generates less organic acid after thermal decomposition. Is more preferable.

  The organic peroxide can be selected from, for example, diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide and the like. Among these, it is preferable to select from peroxyesters, dialkyl peroxides, and hydroperoxides from the viewpoint of suppressing corrosion of connection terminals of circuit members, and from the viewpoint of obtaining high reactivity, it is selected from peroxyesters. More preferably.

  Examples of the diacyl peroxide include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, and succinic peroxide. , Benzoylperoxytoluene, and benzoyl peroxide.

  Examples of peroxydicarbonate include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, Examples include di (2-ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate, and di (3-methyl-3-methoxybutylperoxy) dicarbonate.

  Examples of peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, t -Hexylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis ( 2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethyl Hexanonate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclo Xane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanonate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis (m- Toluoyl peroxy) hexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate.

  Examples of the peroxyketal include 1,1-bis (t-hexylperoxy) -3,5,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis ( t-butylperoxy) -3,5,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane.

  Examples of the dialkyl peroxide include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t -Butyl cumyl peroxide is mentioned.

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

  Examples of the azo compound include 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (1-acetoxy-1-phenylethane), and 2,2′-azobisisobutyronitrile. 2,2′-azobis (2-methylbutyronitrile), dimethyl-2,2′-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid) and 1,1′-azobis ( 1-cyclohexanecarbonitrile).

  Photoinitiators include, for example, benzoin ethers such as benzoin ethyl ether and isopropyl benzoin ether, benzyl ketals such as benzyl and hydroxycyclohexyl phenyl ketone, ketones and derivatives thereof such as benzophenone and acetophenone, thioxanthones, and bisimidazoles Are preferably used.

  When a photoinitiator is used, an optimal photoinitiator is selected according to the wavelength of the light source used, desired curing characteristics, and the like. Moreover, you may use together sensitizers, such as amines, a sulfur compound, and a phosphorus compound, with a photoinitiator in arbitrary ratios as needed.

  Sensitizers include aliphatic amines, aromatic amines, cyclic amines such as piperidine having a nitrogen-containing cyclic structure, o-tolylthiourea, sodium diethyldithiophosphate, soluble sulfinic acid salts, N, N′-dimethyl -P-aminobenzonitrile, N, N'-diethyl-p-aminobenzonitrile, N, N'-di (β-cyanoethyl) -p-aminobenzonitrile, N, N'-di (β-chloroethyl)- P-aminobenzonitrile, tri-n-butylphosphine and the like are preferable. As sensitizers, propiophenone, acetophenone, xanthone, 4-methylacetophenone, benzophenone, fluorene, triphenylene, biphenyl, thioxanthone, anthraquinone, 4,4'-bis (dimethylamino) benzophenone, 4,4'- Bis (diethylamino) benzophenone, phenanthrene, naphthalene, 4-phenylacetophenone, 4-phenylbenzophenone, 1-iodonaphthalene, 2-iodonaphthalene, acenaphthene, 2-naphthonitrile, 1-naphthonitrile, chrysene, benzyl, fluoranthene, pyrene, Non-pigment sensitizers such as 1,2-benzoanthracene, acridine, anthracene, perylene, tetracene, 2-methoxynaphthalene, thionine, methylene blue, lumiflavin, ribo Rabin, lumichrome, coumarin, psoralen, 8-methoxypsoralen, 6-methylcoumarin, 5-methoxypsoralen, 5-hydroxypsoralen, coumarylpyrone, acridine orange, acriflavine, proflavine, fluorescein, eosin Y, eosin B, erythrosine, rose Examples include dye-based sensitizers such as Bengal.

  These (a) free radical generators can be used singly or in combination of two or more, and may be used by mixing a decomposition accelerator, an inhibitor and the like.

  (A) 0.05-10 mass% is preferable with respect to the whole adhesive agent component, and, as for content of a free radical generator, 0.1-5 mass% is more preferable.

  The (b) radical polymerizable substance is a substance having a functional group that is polymerized by radicals, and examples thereof include acrylates (including corresponding methacrylates; the same shall apply hereinafter) and maleimide compounds.

  Examples of the acrylate include urethane acrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylol methane tetraacrylate, 2- Hydroxy-1,3-diaacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, dicyclopentenyl acrylate , Tricyclodecanyl acrylate, bis (acryloxyethyl) isocyanurate, ε-caprolactone-modified tris (acryloxyethyl) Isocyanurate, tris (acryloyloxyethyl) isocyanurate.

  As the maleimide compound, those containing at least two maleimide groups in the molecule are preferable. For example, 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N, N ′ -P-phenylene bismaleimide, N, N'-m-toluylene bismaleimide, N, N'-4,4-biphenylene bismaleimide, N, N'-4,4- (3,3'-dimethyl-biphenylene ) Bismaleimide, N, N′-4,4- (3,3′-dimethyldiphenylmethane) bismaleimide, N, N′-4,4- (3,3′-diethyldiphenylmethane) bismaleimide, N, N ′ -4,4-diphenylmethane bismaleimide, N, N'-4,4-diphenylpropane bismaleimide, N, N'-4,4-diphenyl ether bisma Imido, N, N′-3,3′-diphenylsulfone bismaleimide, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-4,8 -(4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] decane, 4,4'-cyclohexylidene-bis [1- (4-maleimidophenoxy) -2 -Cyclohexyl] benzene, 2,2-bis [4- (4-maleimidophenoxy) phenyl] hexafluoropropane. These may be used alone or in combination of two or more, and may be used in combination with allyl compounds such as allylphenol, allylphenyl ether, and allyl benzoate.

  (B) As a radically polymerizable substance, an acrylate is preferable from the viewpoint of improving adhesiveness, and urethane acrylate or urethane methacrylate is more preferable. (B) A radically polymerizable substance can be used individually by 1 type or in combination of 2 or more types.

  The adhesive component 11a preferably contains at least a radical polymerizable substance having a viscosity at 25 ° C. of 100,000 to 1,000,000 mPa · s, and more preferably contains a radical polymerizable substance of 100,000 to 500,000 mPa · s. The viscosity of the radical polymerizable substance can be measured using a commercially available E-type viscometer.

  (B) In addition to the radical polymerizable substance, the radical polymerizable substance is further crosslinked with the organic peroxide in order to improve heat resistance, and further includes a radical polymerizable substance having a Tg of 100 ° C. or more alone. It is particularly preferable to contain it. As such a radically polymerizable substance, a substance having a dicyclopentenyl group, a tricyclodecanyl group and / or a triazine ring can be used. Among these, radically polymerizable substances having a tricyclodecanyl group or a triazine ring are preferably used.

  Moreover, you may use suitably polymerization inhibitors, such as hydroquinone and methyl ether hydroquinones, as needed.

  Furthermore, it is preferable that the (b) radical polymerizable substance further contains a radical polymerizable substance having a phosphate ester structure in addition to the radical polymerizable substance. The radically polymerizable substance having a phosphoric ester structure is obtained as a reaction product of phosphoric anhydride and 2-hydroxyl (meth) acrylate. Specific examples include 2-methacryloyloxyethyl acid phosphate and 2-acryloyloxyethyl acid phosphate. These can be used individually by 1 type or in combination of 2 or more types.

  The content of the radical polymerizable substance having a phosphate ester structure is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the adhesive component from the viewpoint of improving the adhesive strength with the surface of an inorganic substance such as metal. More preferable is 5 to 5 parts by mass.

  The adhesive component 11a may contain, for example, (c) a thermosetting resin and (d) the curing agent.

(C) As the thermosetting resin, an epoxy resin is preferable. The epoxy resin is used alone or in combination of two or more of various epoxy compounds having two or more glycidyl groups in one molecule. Epoxy resins include bisphenol-type epoxy resins derived from epichlorohydrin and bisphenol A, bisphenol F and / or bisphenol AD, skeletons containing epoxy novolac resins derived from epichlorohydrin and phenol novolac or cresol novolac, and naphthalene rings. Naphthalene type epoxy resin having glycidyl amine type epoxy resin, glycidyl ether type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin and the like. Epoxy resins can be used alone or in combination of two or more. For the epoxy resin, it is preferable to use a high-purity product in which impurity ions (Na ⁺ , Cl ^−, etc.), hydrolyzable chlorine, etc. are reduced to 300 ppm or less.

  (D) The curing agent is preferably a latent curing agent from the viewpoint of obtaining a longer pot life. When the thermosetting resin is an epoxy resin, examples of the latent curing agent include imidazole series, hydrazide series, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt, dicyandiamide, and the like. These can be used individually by 1 type or in mixture of 2 or more types. The latent curing agent may be mixed with a decomposition accelerator, an inhibitor and the like. The latent curing agent is preferably microencapsulated by coating with a polyurethane-based or polyester-based polymeric substance or the like because the pot life is extended.

  Moreover, it is preferable to use the circuit connection material 1 of this embodiment in a film form from a viewpoint which is excellent in handleability. In this case, the adhesive component 11a may contain a film-forming polymer. As film-forming polymers, polystyrene, polyethylene, polyvinyl butyral, polyvinyl formal, polyimide, polyamide, polyester, polyvinyl chloride, polyphenylene oxide, urea resin, melamine resin, phenol resin, xylene resin, epoxy resin, polyisocyanate resin, Phenoxy resin, polyimide resin, polyester urethane resin or the like is used.

  Among these, a resin having a functional group such as a hydroxyl group is more preferable from the viewpoint of improving adhesiveness. Moreover, what modified | denatured the said film forming polymer with the radically polymerizable functional group can also be used. The weight average molecular weight of the film-forming polymer is preferably 10,000 or more. Further, the weight average molecular weight is preferably less than 1,000,000 because the mixing property tends to decrease when it becomes 1,000,000 or more.

In addition, the weight average molecular weight in this specification is calculated | required by measuring on the following conditions by gel permeation chromatography (GPC) analysis, and converting using the analytical curve of a standard polystyrene.
(GPC conditions)
Equipment used: Hitachi L-6000 type (manufactured by Hitachi, Ltd., trade name)
Detector: L-3300RI (trade name, manufactured by Hitachi, Ltd.)
Column: Gel pack GL-R420 + Gel pack GL-R430 + Gel pack GL-R440 (3 in total) (trade name, manufactured by Hitachi Chemical Co., Ltd.)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 1.75 ml / min

(Conductive particles)
The circuit connection material 1 of the present embodiment includes, as conductive particles, first conductive particles 12a covered with an outermost layer containing a predetermined substance, and second conductive particles 12b covered with an outermost layer containing Au. contains.

  First, the configuration of the first conductive particles 12a will be described in detail with reference to FIG. FIG. 2 is a schematic cross-sectional view showing conductive particles contained in a circuit connection material according to an embodiment of the present invention.

  As shown in FIG. 2A, the conductive particle 12 a includes a nucleus body 21 and a metal layer (outermost layer) 22 formed on the surface of the nucleus body 21. The core body 21 has a core portion 21a and a protrusion 21b formed on the surface of the core portion 21a. The metal layer 22 has a plurality of protrusions 14 on the surface. The metal layer 22 covers the core body 21 and protrudes at a position corresponding to the protruding portion 21 b, and the protruding portion is the protruding portion 14.

  The nucleus 21 is preferably made of an organic polymer compound. In this case, the core body 21 is preferably used as a circuit connection material because it has a lower cost than a core body made of metal and has a wide elastic deformation range with respect to a coefficient of thermal expansion and a dimensional change during pressure bonding.

  Examples of the organic polymer compound constituting the core portion 21a of the core body 21 include acrylic resin, styrene resin, benzoguanamine resin, silicone resin, polybutadiene resin, or a copolymer thereof. May be. The organic polymer compound constituting the protruding portion 21b of the core body 21 may be the same as or different from the organic polymer compound constituting the core portion 21a.

  The average particle size of the core portion 21a of the core 21 is preferably 1 to 10 μm, more preferably 2 to 8 μm, and still more preferably 3 to 5 μm. When the average particle size is less than 1 μm, secondary aggregation of the particles occurs, and the insulation with an adjacent circuit tends to be insufficient. On the other hand, if the average particle diameter exceeds 10 μm, the insulation with an adjacent circuit tends to be insufficient due to the size.

  The core 21 can be formed by adsorbing a plurality of protrusions 21b having a smaller diameter than the core 21a on the surface of the core 21a. As a method for adsorbing the protrusion 21b on the surface of the core 21a, for example, the core 21a and the protrusion 21b or both particles may be diluted with various coupling agents such as silane, aluminum, titanium, and an adhesive. After surface treatment, the method of mixing and adhering both is mentioned. In addition, it is preferable that the average particle diameter of the protrusion part 21b is 50-500 nm.

  The metal layer 22 includes a metal having a Vickers hardness of 300 Hv or more, such as Ni, Pd, and Rh. Examples of Ni include at least one selected from the group consisting of pure Ni, Ni alloys, and Ni oxides. Among these, pure Ni is preferable. Similarly, pure Pd is preferable as Pd. Examples of the Ni alloy include Ni-B, Ni-W, Ni-B, Ni-W-Co, Ni-Fe, and Ni-Cr. Examples of the Ni oxide include NiO. The metal layer 22 may be composed of a single metal layer or may be composed of a plurality of metal layers. The Vickers hardness can be measured using, for example, “Maicroharadness Tester MHT-4 (trade name)” manufactured by Japan High-Tech, under the conditions of a load load of 20 kgf, a load speed of 20 kgf / second, and a holding time of 5 seconds. .

  The metal layer 22 can be formed by plating these metals on the core 21 using an electroless plating method. The electroless plating method is roughly divided into a batch method and a continuous dropping method, and the metal layer 22 can be formed by using any method.

  50-170 nm is preferable and, as for the thickness (thickness of plating) of the metal layer 22, 50-150 nm is more preferable. By setting the thickness of the metal layer 22 in such a range, the connection resistance between the circuit electrodes 32 and 42 can be further reduced. If the thickness of the metal layer 22 is less than 50 nm, plating defects tend to occur, and if it exceeds 170 nm, condensation occurs between the conductive particles and a short circuit tends to occur between adjacent circuit electrodes.

  Note that the core 21 may be partially exposed from the conductive particles 12a. In this case, from the viewpoint of connection reliability, the coverage of the metal layer 22 with respect to the surface area of the core 21 is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. preferable.

  The height (H) of the protrusion 14 of the conductive particle 12a is preferably 50 to 500 nm, and more preferably 75 to 300 nm. If the height (H) of the protrusion 14 is less than 50 nm, the connection resistance tends to increase after the high-temperature and high-humidity treatment. If the height (H) exceeds 500 nm, the contact area between the conductive particles and the circuit electrode becomes small, so the connection resistance Tend to be higher.

  The distance (S) between the adjacent protrusions 14 is preferably 1000 nm or less, and more preferably 500 nm or less. Further, the distance (S) between the adjacent protrusions 14 is sufficient that the cured body 11b of the adhesive component 11a does not enter between the conductive particles 12a and the circuit electrodes 32 and 42, which will be described later, and the conductive particles 12a and the circuit electrodes sufficiently. In order to make 32 and 42 contact, it is preferable that it is at least 50 nm or more. In addition, the height (H) of the protrusion part 14 and the distance (S) between the adjacent protrusion parts 14 can be measured with an electron microscope.

  In addition, as shown in FIG.2 (b), as for the electrically-conductive particle 12a, the nucleus 21 may be comprised only by the core part 21a. In other words, the protrusion 21b may not be provided in the core body 21 shown in FIG. The conductive particles 12a shown in FIG. 2B can be obtained by metal-plating the surface of the core 21a and forming the metal layer 22 having the protrusions 14 on the surface of the core 21a.

  A plating method for forming the protrusion 14 will be described. The protrusion 14 can be formed by changing the plating conditions in the middle of metal plating and partially changing the thickness of the metal layer 22. For example, the protrusion 14 can be formed by adding a plating solution having a higher concentration than the plating solution used first in the course of the plating reaction and making the concentration of the plating solution non-uniform.

  The content of the conductive particles 12a is preferably 0.1 to 30 parts by volume with respect to 100 parts by volume of the adhesive component, and is appropriately adjusted according to the application. In addition, the content of the conductive particles 12a is more preferably 0.1 to 10 parts by volume with respect to 100 parts by volume of the adhesive component from the viewpoint of more sufficiently suppressing short circuit between adjacent circuits due to the conductive particles 12a.

From the viewpoint of further ensuring the conduction between the circuit electrodes 32 and 42, the 10% compression elastic modulus (K value) of the conductive particles 12a is preferably 100 to 1000 kgf / mm ² . Here, the 10% compression modulus (K value) refers to the modulus of elasticity when the conductive particles 12a are 10% compressed and deformed, and can be measured by, for example, an H-100 microhardness meter manufactured by Fisher Instruments Inc. it can.

  In addition, the conductive particles 12a may be formed by coating insulating particles such as non-conductive glass, ceramic, and plastic with a metal layer 22 containing Ni or the like. When the metal layer 22 contains Ni and the core 21 is plastic, or when the conductive particles 12a are hot-melt metal particles, the metal layer 22 is deformable by heating and pressurization, and the conductive particles 12a and the electrodes are connected at the time of connection. This is preferable because the contact area is increased and the connection reliability is improved.

  Next, the second conductive particles 12b will be described. As shown in FIG. 2C, the conductive particle 12b includes a core portion 21a and a metal layer (outermost layer) 23 formed on the surface of the core portion 21a. The conductive particle 12b is different from the conductive particle 12a in that the conductive particle 12b does not have the protrusion 14 and the metal layer 23 contains Au. Note that the conductive particles 12b may have protrusions on the surface of the metal layer 23 in the same manner as the conductive particles 12a.

  Regarding the conductive particles 12b, the preferred range of the content and compression modulus, the material and average particle diameter of the core 21a, the thickness and coverage of the metal layer 23, and the like are the same as those of the conductive particles 12a.

  The average particle diameter of at least one of the conductive particles 12a and the conductive particles 12b is preferably 1 to 10 μm, more preferably 2 to 8 μm, from the viewpoint that the short circuit between adjacent electrodes can be suppressed by making it lower than the height of the circuit electrode to be connected. 3 to 5 μm is more preferable. Moreover, it is preferable that the average particle diameter of both the electroconductive particle 12a and the electroconductive particle 12b is the said range. Note that the “average particle diameter” of the conductive particles 12a does not consider the height (H) of the protrusions 14 but considers the core 21 and the portion of the metal layer 22 where the protrusions 14 are not formed. It shall mean the calculated particle size.

  The average particle diameter of the conductive particles 12a and 12b can be measured as follows. 50 particles are arbitrarily selected from the particle image of the conductive particles magnified 3000 times with a differential scanning electron microscope (SEM: for example, S800, manufactured by HITACHI). Using the enlarged particle image, the maximum diameter and the minimum diameter are measured for each of the selected plurality of particles. The square root of the product of the maximum diameter and the minimum diameter of each particle is defined as the particle diameter of the particle. The particle diameter of each of 50 arbitrarily selected conductive particles is measured as described above, and the value obtained by dividing the sum of the particle diameters by the measured number of particles is taken as the average particle diameter.

  The number ratio (B) / (A) of the number (B) of the conductive particles 12b to the number (A) of the conductive particles 12a per unit volume in the circuit connecting material 1 is 0.4 to 3, and 0.45 to 2.5 is preferable, and 0.5 to 2.0 is more preferable. When the number ratio (B / A) is less than 0.4, the resistance value of a high-resistance substrate such as IZO tends to increase, and when it exceeds 3, the pot life tends to decrease.

  The number ratio (B / A) of the conductive particles 12a and 12b in the circuit connection material 1 was obtained by dissolving the circuit connection material 1 in a solvent capable of dissolving the adhesive component and removing excess solvent and the like from the obtained insoluble component. Thereafter, it can be calculated by observing arbitrarily 100 or more conductive particles in the residue using a differential scanning microscope and measuring the number of conductive particles 12a and 12b, respectively. Although it does not specifically limit as a solvent which can melt | dissolve an adhesive agent component, For example, MEK (methyl ethyl ketone) and toluene are mentioned.

  The ratio (b) / (a) of the content (b) of the conductive particles 12b to the content (a) of the conductive particles 12a in the circuit connection material 1 is preferably 0.4 to 3, and preferably 0.45 to 0.45. 2.5 is more preferable, and 0.5 to 2.0 is still more preferable. When the ratio (b / a) is less than 0.4, the resistance value of a high-resistance substrate such as IZO tends to increase, and when it exceeds 3, the pot life tends to decrease.

  The ratio (b / a) of the conductive particles 12a and 12b in the circuit connecting material 1 is calculated by converting the volume ratio from the number of conductive particles per unit volume of the circuit connecting material 1 and the average particle diameter of the conductive particles. be able to. Note that the “volume” of the conductive particles is such that the ratio of the volume of the protrusions to the entire conductive particles is very small, so the volume of the protrusions is not considered in the calculation of the ratio (b / a) of the conductive particles. .

  Furthermore, the circuit connection material 1 of the present embodiment includes rubber fine particles, fillers, softeners, accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents, phenol resins, melamine resins, Isocyanates can also be contained.

  As the rubber fine particles, the average particle size of the particles is not more than twice the average particle size of the conductive particles 12a and 12b to be blended, and the storage elastic modulus at room temperature (25 ° C.) is the conductive particles 12a and 12b and the adhesive. What is 1/2 or less of the storage elastic modulus of the component 11a at room temperature is preferable. In particular, when the material of the rubber fine particles is silicone, acrylic emulsion, SBR, NBR, or polybutadiene rubber, it is preferable to use one kind alone or a mixture of two or more kinds. These three-dimensionally crosslinked rubber fine particles have excellent solvent resistance and are easily dispersed in the adhesive component 11a.

  The inclusion of a filler is preferable because connection reliability and the like are improved. The maximum diameter of the filler is preferably less than the average particle diameter of the conductive particles 12a and 12b. The content of the filler is preferably in the range of 5 to 60% by volume with respect to the entire circuit connecting material. When the content exceeds 60% by volume, the effect of improving reliability tends to be saturated.

  As the coupling agent, a compound containing one or more groups selected from the group consisting of a vinyl group, an acrylic group, an amino group, an epoxy group, and an isocyanate group is preferable from the viewpoint of improving adhesiveness.

  The circuit connecting material 1 of the present embodiment is electrically conductive when separated into a layer containing a reactive resin and a layer containing a latent curing agent, or a layer (insulating layer) containing a curing agent that generates free radicals. When separated into a layer containing particles, in addition to the conventional high-definition effect, a further improvement effect of pot life can be obtained.

  In the calculation of the number ratio (B / A) and volume ratio (b / a) of the conductive particles 12a and 12b, when the circuit connecting material 1 has a layer containing conductive particles and a layer not containing conductive particles. The number ratio and volume ratio of the conductive particles 12a and 12b mean values in a layer including the conductive particles.

  In the circuit connection material 1 of the present embodiment, the adhesive melts and flows at the time of connection, and the circuit electrodes facing each other are connected and then cured to maintain the connection. The fluidity of the adhesive is an important factor. . When the circuit connection material 1 having a thickness of 35 μm and 5 mm × 5 mm is sandwiched between a glass plate having a thickness of 0.7 mm and 15 mm × 15 mm, and heating and pressing are performed under conditions of 170 ° C., 2 MPa, 10 seconds, the initial area The value of fluidity (B) / (A) expressed using (A) and the area (B) after heating and pressing is preferably 1.3 to 3.0, and preferably 1.5 to 2 .5 is more preferable. When (B) / (A) is less than 1.3, the fluidity is poor and there is a tendency that good connection cannot be obtained. When it exceeds 3.0, bubbles tend to be generated and the reliability tends to be poor.

  100-3000 MPa is preferable and, as for the elasticity modulus in 40 degreeC after hardening of the circuit connection material 1 of this embodiment, 500-2000 MPa is more preferable.

<Circuit connection structure>
FIG. 3 is a schematic cross-sectional view showing a circuit connection structure according to an embodiment of the present invention. The circuit connection structure 100 of the present embodiment is interposed between the circuit member (first circuit member) 30 and the circuit member (second circuit member) 40 facing each other, and the circuit member 30 and the circuit member 40. And a circuit connecting member 10 for connecting them.

  The circuit member 30 includes a circuit board (first circuit board) 31 and a circuit electrode (first circuit electrode) 32 formed on the main surface 31 a of the circuit board 31. The circuit member 40 includes a circuit board (second circuit board) 41 and a circuit electrode (second circuit electrode) 42 formed on the main surface 41 a of the circuit board 41.

  The material of the circuit boards 31 and 41 is not particularly limited, but is usually an organic insulating material, glass or silicon.

  Examples of the material of the circuit electrodes 32 and 42 include Au, Ag, Sn, and Pt group metals, ITO, IZO, Al, and Cr. At least one of the circuit electrodes 32 and 42 preferably includes at least one of ITO and IZO from the viewpoint that the electrical connection is remarkably improved. Further, the circuit electrodes 32 and 42 may be entirely made of the above material, or only the outermost layer may be made of the above material.

  The surfaces of the circuit electrodes 32 and 42 are preferably flat. In the present specification, “the surface of the circuit electrode is flat” means that the unevenness of the surface of the circuit electrode is 20 nm or less.

  When the thickness of the circuit electrodes 32 and 42 is less than 50 nm, when the circuit connecting material 1 is pressed between the circuit member 30 and the circuit member 40, the protrusions 14 on the surface side of the conductive particles 12a in the circuit connecting material 1 are formed. In some cases, the circuit electrodes 32 and 42 may be penetrated and contacted with the circuit boards 31 and 41. Therefore, by setting the thickness of the circuit electrodes 32 and 42 to 50 nm or more, the contact area between the circuit electrodes 32 and 42 and the conductive particles 12a is increased, and the connection resistance is further reduced. In addition, the thickness of the circuit electrodes 32 and 42 is preferably 1000 nm or less, and more preferably 500 nm or less from the viewpoint of manufacturing cost.

  In the circuit member 30, an insulating layer may be further provided between the circuit electrode 32 and the circuit board 31. In the circuit member 40, an insulating layer is further provided between the circuit electrode 42 and the circuit board 41. May be. The material of the insulating layer is not particularly limited as long as it is made of an insulating material, but is usually an organic insulating material, silicon dioxide or silicon nitride.

  Specific examples of the first circuit member 30 and the second circuit member 40 include chip components such as a semiconductor chip, a resistor chip, and a capacitor chip, and a substrate such as a printed circuit board. These circuit members 30 and 40 are usually provided with a large number of circuit electrodes (connection terminals) 32 and 42 (in some cases, the number may be one).

  The circuit connection member 10 is obtained by curing the circuit connection material 1, and includes a cured body 11b obtained by curing the adhesive component 11a and the conductive particles 12a and 12b.

  In the circuit connection structure 100, the circuit electrode 32 and the circuit electrode 42 facing each other are electrically connected via the first conductive particles 12a and the second conductive particles 12b. That is, the conductive particles 12 a and 12 b are in direct contact with both the circuit electrodes 32 and 42. Specifically, the protrusions 14 of the conductive particles 12a pass through the cured body 11b and are in contact with the circuit electrodes 32 and 42, and the surfaces of the conductive particles 12b are in contact with the circuit electrodes 32 and 42. For this reason, the connection resistance between the circuit electrodes 32 and 42 is sufficiently reduced, and a good electrical connection between the circuit electrodes 32 and 42 becomes possible. Therefore, the flow of current between the circuit electrodes 32 and 42 can be made smooth, and the functions of the circuit can be fully exhibited. Note that, by being pressed by the conductive particles 12a and 12b, steps of heights T1 and T2 are formed on the surfaces of the circuit electrode 32 and the circuit electrode 42, for example.

  It is preferable that some of the plurality of protruding portions 14 of the conductive particles 12a bite into the circuit electrode 32 or the circuit electrode 42. In this case, the contact area between the projecting portion 14 of the conductive particle 12a and the circuit electrodes 32 and 42 is further increased, and the connection resistance can be further reduced.

(Method for manufacturing circuit connection structure)
The circuit connection material 1 of the present embodiment is also useful as a film adhesive for bonding an IC chip and a substrate or bonding electric circuits to each other. The first circuit electrode and the second circuit electrode are opposed to the first circuit member having the first circuit electrode (connection terminal) and the second circuit member having the second circuit electrode (connection terminal). The first circuit electrode and the second circuit are arranged in such a state that the circuit connection material 1 of the present embodiment is interposed between the first circuit electrode and the second circuit electrode and heated and pressurized. The circuit connection structure 100 can be configured by electrically connecting the electrodes.

  In the circuit electrode connection method used in the present embodiment, the circuit connection material 1 having heat or light curability is formed on one electrode circuit containing a metal whose surface is selected from gold, silver, tin and white metal. Thereafter, the circuit electrodes can be connected to each other by aligning the other circuit electrode and heating and pressurizing.

  Examples of the circuit connection structure 100 according to the present embodiment include chip components such as semiconductor chips, resistor chips, and capacitor chips, and substrates such as printed boards. These circuit connection structures 100 are usually provided with a large number of circuit electrodes (connection terminals) (may be a single terminal in some cases), and at least one set of the circuit connection structures 100 is attached to the circuit connection structures 100. At least a part of the provided connection terminals is arranged to face each other, an adhesive is interposed between the arranged circuit electrodes, and the circuit electrodes arranged to face each other by heating and pressing are electrically connected to form a circuit board. By heating and pressing at least one set of the circuit connection structure 100, the circuit electrodes arranged opposite to each other are electrically connected by direct contact or through conductive particles of an anisotropic conductive adhesive (circuit connection material). be able to.

  Next, the manufacturing method of the circuit connection structure 70 of the present embodiment will be specifically described with reference to FIG. FIG. 4 is a process cross-sectional view schematically showing a method for manufacturing a circuit connection structure according to an embodiment of the present invention. FIG. 4A shows a state before the circuit members are connected to each other, FIG. 4B shows a state when the circuit members are connected to each other, and FIG. The circuit connection structure after connecting is shown.

  First, as shown in FIG. 4A, an LCD panel 73 having a circuit electrode 72 and a liquid crystal display 74 on the main surface is prepared. Next, the film-like circuit connecting material 61 is adhered and placed on the circuit electrode 72. Then, the circuit board 75 provided with the circuit electrode 76 such as COF is aligned so that the circuit electrode 72 and the circuit electrode 76 face each other with the circuit connection material 61 therebetween. The circuit electrode 72 and the circuit electrode 76 have, for example, a structure in which a plurality of electrodes are arranged.

  Next, as shown in FIG. 4B, while aligning the LCD panel 73 and the circuit board 75, the circuit electrode 72 and the circuit electrode 76 face each other with the circuit connection material 61 therebetween. A circuit board 75 is placed on the circuit connection material 61. As a result, the circuit electrode 72 and the circuit electrode 76 are connected by the conductive particles 12 a and 12 b in the circuit connection material 61.

  Next, the circuit board 75 is pressurized from the surface opposite to the surface on which the circuit electrode 76 is disposed (in the direction of arrow A in FIG. 4B), and the circuit connection material 61 is heated. Thereby, the circuit connection material 61 is hardened and the circuit connection member 60 is obtained. 4C, the circuit connection structure 70 in which the LCD panel 73 and the circuit board 75 are firmly connected via the circuit connection member 60 is obtained. In addition, the method of a hardening process can employ | adopt one or both of a heating and light irradiation according to the adhesive agent component to be used.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

Example 1
[Synthesis of urethane acrylate]
While stirring 400 parts by mass of polycaprolactone diol having a weight average molecular weight of 800, 131 parts by mass of 2-hydroxypropyl acrylate, 0.5 parts by mass of dibutyltin dilaurate as a catalyst, and 1.0 part by mass of hydroquinone monomethyl ether as a polymerization inhibitor, 50 Heat to ℃ and mix. Next, 222 parts by mass of isophorone diisocyanate was dropped, and the temperature was raised to 80 ° C. while stirring to carry out a urethanization reaction. After confirming that the reaction rate of the isocyanate group was 99% or more, the reaction temperature was lowered to obtain urethane acrylate.

[Preparation of polyester urethane resin]
Using terephthalic acid as the dicarboxylic acid, propylene glycol as the diol, and 4,4′-diphenylmethane diisocyanate as the isocyanate, the molar ratio of terephthalic acid / propylene glycol / 4,4′-diphenylmethane diisocyanate is 1.0 / 1.3 / 0. A polyester urethane resin of 25 was prepared.

  The said polyester urethane resin was melt | dissolved in methyl ethyl ketone so that it might become 20 mass%. Using a methyl ethyl ketone solution of the above-mentioned polyester urethane resin, it was applied to a PET film having a thickness of 80 [mu] m on one surface (silicone treatment) using a coating apparatus. Furthermore, a film having a thickness of 35 μm was produced by hot air drying at 70 ° C. for 10 minutes. The temperature dependence of the elastic modulus was measured at a tensile load of 5 g and a frequency of 10 Hz using a wide-range dynamic viscoelasticity measuring device (trade name: RSAII, manufactured by Rheometric Scientific). The glass transition temperature of the polyester urethane resin obtained from the measurement results was 105 ° C.

  As a radical polymerizable substance, 25 parts by mass of the urethane acrylate, 20 parts by mass of isocyanurate acrylate (product name: M-325, manufactured by Toagosei Co., Ltd.), 2-methacryloyloxyethyl acid phosphate (product name: P-2M, 1 part by mass of Kyoeisha Chemical Co., Ltd.), 4 parts by mass of benzoyl peroxide (product name: Nyper BMT-K40, manufactured by NOF Corporation) as a free radical generator, and 20% methyl ethyl ketone of the polyester urethane resin as a film-forming polymer The solution was mixed with 55 parts by mass and stirred to obtain a binder resin.

  Furthermore, conductive particles (average particle diameter: 4 μm, hereinafter referred to as “Ni-coated particles” in some cases) covered with the outermost layer containing Ni and having protrusions on the surface of the outermost layer are added to the solid content of the binder resin. The conductive particles covered with the outermost layer containing 2% by volume of Au (average particle diameter: 4 μm, hereinafter referred to as “Au-coated particles” in some cases) were mixed and dispersed by 1% by volume. Then, the mixed solution was applied to a PET film having a thickness of 50 μm with one surface treated (silicone treatment) using a coating apparatus, and dried with hot air at 70 ° C. for 10 minutes, so that the adhesive layer had a thickness of 16 μm. A direction conductive adhesive layer A (width 15 cm, length 70 m) was obtained. The obtained anisotropic conductive adhesive layer A was cut into a width of 1.5 mm, and wound on the side surface (thickness 1.7 mm) of a plastic reel having an inner diameter of 40 mm and an outer diameter of 48 mm with the adhesive film surface facing inward for 50 m, A tape-like circuit connection film was obtained.

(Examples 2 to 6)
A circuit connection film was produced in the same manner as in Example 1 except that the content of the conductive particles was changed as shown in Table 1.

(Examples 7 to 12)
A circuit connection film was prepared in the same manner as in Example 1 except that the Ni coated particles and the Au coated particles were each changed to those having an average particle size of 3 μm, and the blending amount of the conductive particles was changed as shown in Table 2. Produced.

(Comparative Examples 1-6)
A circuit connection film was produced in the same manner as in Example 1 except that the content of the conductive particles was changed as shown in Table 3.

(Comparative Examples 7-12)
A circuit connection film was prepared in the same manner as in Example 1 except that the Ni-coated particles and the Au-coated particles were each changed to those having an average particle size of 3 μm and the content of the conductive particles was changed as shown in Table 4. Produced.

(Circuit connection)
An adhesive-coated surface of the circuit connection films (width 1.5 mm, length 3 cm) obtained in the Examples and Comparative Examples was heated and pressed at 70 ° C. and 1 MPa for 2 seconds, or a 0.7 mm thick ITO coated glass substrate or It transferred on the Cr / IZO coat glass substrate, and peeled PET film. Next, a flexible circuit board (FPC) having 600 tin-plated copper circuits with a pitch of 50 μm and a thickness of 8 μm was placed on the transferred adhesive, and temporarily fixed by pressing at 24 ° C. and 0.5 MPa for 1 second. A glass substrate on which this FPC is temporarily fixed by a circuit connection film is installed in the main pressure bonding apparatus, and 200 μm-thick silicone rubber is used as a cushioning material, and heated and pressed at 170 ° C. and 3 MPa for 6 seconds from the FPC side by a heat tool. A connection was obtained by connecting over a width of 1.5 mm.

(Measurement of connection resistance)
About the said connection body, the resistance value between the adjacent circuits of said FPC including a connection part was measured with the multimeter (device name: TR6845, the product made by Advantest). For the resistance value, 40 points of resistance between adjacent circuits were measured, and an average value was obtained. The obtained results are shown in Tables 5-8.

(Confirm pot life)
The circuit connection films obtained in Examples and Comparative Examples were exposed for 3 days in a constant temperature bath at 44 ° C. Then, the circuit connection film was used to connect the ITO coated glass substrate, the IZO coated glass substrate and the FPC in the same manner as described above, and then the connection resistance was measured. Pot life was improved when the increase in connection resistance was suppressed after the exposure treatment. The obtained results are shown in Tables 5-8.

  DESCRIPTION OF SYMBOLS 1,61 ... Circuit connection material 10, 60 ... Circuit connection member, 11a ... Adhesive component, 12a ... 1st electroconductive particle, 12b ... 2nd electroconductive particle, 14 ... Protrusion part, 22 ... Metal layer (outermost layer) , 31, 41... Circuit members, 32, 42... Circuit electrodes, 70, 100... Circuit connection structure, H. Height of projections, S. Distance between projections.

Claims (7)

A circuit connecting material that is electrically connected between the circuit electrodes interposed between opposing circuit electrodes,
First conductive particles covered with an outermost layer containing an adhesive component, at least one selected from the group consisting of Ni, Ni alloy and Ni oxide, and second conductive covered with an outermost layer containing Au Particles, and
A plurality of protrusions are formed on the surface of the outermost layer in the first conductive particles,
The circuit connection material, wherein a ratio of the number of the second conductive particles to the number of the first conductive particles per unit volume in the circuit connection material is 0.4 to 3. A circuit connecting material that is electrically connected between the circuit electrodes interposed between opposing circuit electrodes,
Containing an adhesive component, first conductive particles covered with an outermost layer containing a metal having a Vickers hardness of 300 Hv or more, and second conductive particles covered with an outermost layer containing Au,
A plurality of protrusions are formed on the surface of the outermost layer in the first conductive particles,
The circuit connection material, wherein a ratio of the number of the second conductive particles to the number of the first conductive particles per unit volume in the circuit connection material is 0.4 to 3.   The circuit connection material according to claim 1 or 2, wherein a ratio of the content of the second conductive particles to the content of the first conductive particles in the circuit connection material is 0.4 to 3 in volume ratio.   The circuit connection material according to any one of claims 1 to 3, wherein a height of the protrusions of the first conductive particles is 50 to 500 nm, and a distance between the adjacent protrusions is 1000 nm or less. .   The circuit connection material according to any one of claims 1 to 4, wherein an average particle size of at least one of the first conductive particles and the second conductive particles is 1 to 10 µm.   A first circuit member having a first circuit electrode and a second circuit member having a second circuit electrode are arranged with the first circuit electrode and the second circuit electrode facing each other. The first circuit electrode is formed by heating and pressing the circuit connection material according to claim 1 between the first circuit electrode and the second circuit electrode. And a circuit connection structure in which the second circuit electrodes are electrically connected.   The circuit connection structure according to claim 6, wherein at least one of the first circuit electrode and the second circuit electrode includes at least one of indium-tin oxide and indium-zinc oxide.

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