WO2024117181A1 - 導電ペースト、ｒｆｉｄインレイ及びｒｆｉｄインレイの製造方法 - Google Patents

導電ペースト、ｒｆｉｄインレイ及びｒｆｉｄインレイの製造方法 Download PDF

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WO2024117181A1
WO2024117181A1 PCT/JP2023/042741 JP2023042741W WO2024117181A1 WO 2024117181 A1 WO2024117181 A1 WO 2024117181A1 JP 2023042741 W JP2023042741 W JP 2023042741W WO 2024117181 A1 WO2024117181 A1 WO 2024117181A1
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Prior art keywords
conductive
conductive paste
less
meth
acrylate
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PCT/JP2023/042741
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English (en)
French (fr)
Japanese (ja)
Inventor
洋 小林
悠人 土橋
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Sekisui Chemical Co Ltd
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Sekisui Chemical Co Ltd
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Priority to CN202380059013.3A priority Critical patent/CN119678228A/zh
Priority to JP2024519634A priority patent/JP7808187B2/ja
Priority to KR1020247039789A priority patent/KR20250115908A/ko
Publication of WO2024117181A1 publication Critical patent/WO2024117181A1/ja
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/04—Non-macromolecular additives inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
    • C09J9/02—Electrically-conducting adhesives
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
    • H10W72/00—Interconnections or connectors in packages
    • H10W72/071—Connecting or disconnecting

Definitions

  • the present invention relates to a conductive paste containing a conductive filler.
  • the present invention also relates to an RFID inlay using the conductive paste and a method for manufacturing an RFID inlay.
  • UHF Ultra High Frequency
  • RFID inlays which allow contactless data transmission and reception, are widely used in contactless RFID tags and contactless RFID cards.
  • UHF Ultra High Frequency
  • RFID inlays have attracted attention due to their long communication distances, and UHF band RFID inlays are used for a variety of items and purposes, such as commuter passes, inventory management, distribution management, and history management.
  • a conductive paste containing a conductive filler and binder resin may be used to bond and connect a chip with electrodes on its surface to a substrate with wiring (antenna pattern) on its surface.
  • Patent Document 1 discloses an adhesive that can be used for electronic components.
  • the adhesive is an acrylic adhesive composition that contains a radical initiator with a 10-hour half-life temperature of 80°C or less, a vinylene-containing oligomer, and at least one diluent.
  • the adhesive can snap cure at low temperatures, and the pot life of the adhesive at room temperature is 24 hours or more.
  • Patent Document 2 discloses a conductive adhesive that contains a polymerizable acrylic compound, an organic peroxide, and solder particles, and in which the one-minute half-life temperature of the organic peroxide is lower than the solidus temperature of the solder particles.
  • the roll-to-roll method is sometimes adopted to enable mass production.
  • a laminate in which conductive paste and chips are arranged on the surface of a substrate may be transported not only horizontally but also vertically. For example, when a laminate being transported horizontally reaches a roll portion, the transport direction may change to vertical at the roll portion.
  • the conductive material may not be dispersed but may be unevenly distributed, resulting in reduced electrical conductivity reliability of the resulting electronic components.
  • the position of the chips arranged on the surface of the substrate may shift, resulting in reduced electrical conductivity reliability of the resulting electronic components.
  • the object of the present invention is to provide a conductive paste that can be positioned on wiring with high precision, and that can prevent chip misalignment and uneven distribution of conductive filler even when transported vertically during the manufacturing process, thereby improving the electrical conductivity reliability of the resulting electronic components.
  • Another object of the present invention is to provide an RFID inlay that uses the conductive paste, and a method for manufacturing an RFID inlay.
  • This specification discloses the following conductive paste, RFID inlay, and method for manufacturing an RFID inlay.
  • a conductive paste comprising a curable compound, a curing agent, and a plurality of conductive fillers, the specific gravity of the conductive fillers being 1.5 or more and 4.0 or less, the content of the conductive fillers being 1.0% by weight or more and 15% by weight or less in 100% by weight of the conductive paste, the ratio of the viscosity of the conductive paste at 25°C and 0.5 rpm to the viscosity at 25°C and 5 rpm being 1.5 or more and 4.5 or less, and the viscosity of the conductive paste at 25°C and 5 rpm being 5 Pa ⁇ s or more and 50 Pa ⁇ s or less.
  • Item 2 The conductive paste according to item 1, wherein the curable compound includes a (meth)acrylic compound.
  • Item 3 The conductive paste according to item 1 or 2, wherein the conductive filler is a conductive particle, and the particle diameter of the conductive particle is 10 ⁇ m or less.
  • Item 4 The conductive paste according to item 3, wherein the conductive particles include a base particle and a conductive portion disposed on the surface of the base particle.
  • Item 5 The conductive paste according to any one of items 1 to 4, which is applied to a substrate having a surface tension of 30 mN/m or more and 50 mN/m or less.
  • Item 6 A conductive paste according to any one of items 1 to 5, used to obtain an RFID inlay.
  • Item 7 An RFID inlay comprising a substrate having wiring on its surface, a chip having electrodes on its surface, and an adhesive portion bonding the substrate and the chip, the adhesive portion being made of the conductive paste described in any one of items 1 to 6, and the wiring and the electrodes being electrically connected by the conductive filler in the adhesive portion.
  • Item 8 A method for manufacturing an RFID inlay, comprising: a first arrangement step of arranging the conductive paste described in any one of items 1 to 6 on a surface of a substrate having wiring on its surface; a second arrangement step of arranging a chip having an electrode on its surface on the surface of the conductive paste opposite the substrate; and a bonding step of forming an adhesive part that bonds the substrate and the chip with the conductive paste by heating and pressurizing the conductive paste, and electrically connecting the wiring and the electrode with the conductive filler in the adhesive part.
  • Item 9 The method for manufacturing an RFID inlay according to Item 8, in which the substrate is long and the RFID inlay is manufactured by transporting the long substrate in the first placement process, the second placement process, and the bonding process using a roll-to-roll method.
  • the conductive paste according to the present invention is a conductive paste containing a curable compound, a curing agent, and a plurality of conductive fillers.
  • the specific gravity of the conductive filler is 1.5 or more and 4.0 or less.
  • the content of the conductive filler in 100% by weight of the conductive paste is 1.0% by weight or more and 15% by weight or less.
  • the ratio of the viscosity of the conductive paste at 25°C and 0.5 rpm to the viscosity at 25°C and 5 rpm is 1.5 or more and 4.5 or less, and the viscosity of the conductive paste at 25°C and 5 rpm is 5 Pa ⁇ s or more and 50 Pa ⁇ s or less. Since the conductive paste according to the present invention has the above configuration, the conductive paste can be arranged on the wiring with high precision, and even when the transported object is transported vertically in the manufacturing process, it is possible to prevent the chip from being misaligned and the conductive filler from being unevenly distributed, and the electrical reliability of the obtained electronic component can be improved.
  • FIG. 1 is a cross-sectional view showing a schematic diagram of an RFID inlay using a conductive paste according to a first embodiment of the present invention.
  • the conductive paste according to the present invention is a conductive paste containing a curable compound, a curing agent, and a plurality of conductive fillers.
  • the specific gravity of the conductive filler is 1.5 or more and 4.0 or less.
  • the content of the conductive filler in 100% by weight of the conductive paste is 1.0% by weight or more and 15% by weight or less.
  • the ratio of the viscosity of the conductive paste at 25°C and 0.5 rpm to the viscosity at 25°C and 5 rpm is 1.5 or more and 4.5 or less, and the viscosity of the conductive paste at 25°C and 5 rpm is 5 Pa ⁇ s or more and 50 Pa ⁇ s or less.
  • the conductive paste according to the present invention has the above-mentioned configuration, so that the conductive paste can be placed on the wiring with high precision. Furthermore, the conductive paste according to the present invention has the above-mentioned configuration, so that even when the transported object is transported vertically in the manufacturing process, it is possible to prevent the chip from shifting in position and the conductive filler from being unevenly distributed, and to disperse the conductive filler well. As a result, it is possible to improve the reliability of conductivity. For example, when the transported object being transported horizontally reaches the roll portion, the transport direction may change to vertical at the roll portion. In this case, the orientation of the transported object changes, making it easy for the chip to shift in position and the conductive filler to be unevenly distributed. However, the configuration of the present invention makes it possible to prevent the chip from shifting in position and the conductive filler from being unevenly distributed.
  • the conductive paste according to the present invention is in a paste form at 25°C.
  • the conductive paste is used by discharging it at, for example, 20°C to 50°C. It is preferable that the conductive paste according to the present invention is used by discharging it using a jet dispenser.
  • the viscosity ( ⁇ A) of the conductive paste at 25°C and 5 rpm is 5 Pa ⁇ s or more and 50 Pa ⁇ s or less.
  • the viscosity ( ⁇ A) is preferably 7 Pa ⁇ s or more, more preferably 8 Pa ⁇ s or more, even more preferably 10 Pa ⁇ s or more, and is preferably 45 Pa ⁇ s or less, more preferably 43 Pa ⁇ s or less, and even more preferably 40 Pa ⁇ s or less. If the viscosity ( ⁇ A) is equal to or greater than the lower limit, the chip can be more effectively prevented from shifting in position even when the transported object is transported vertically in the manufacturing process. If the viscosity ( ⁇ A) is equal to or less than the upper limit, the conductive paste can be placed on the fine wiring with even greater precision.
  • the ratio ( ⁇ B/ ⁇ A) of the viscosity ( ⁇ B) of the conductive paste at 25°C and 0.5 rpm to the viscosity ( ⁇ A) at 25°C and 5 rpm of the conductive paste is the thixotropic index.
  • the ratio (thixotropic index) of the viscosity ( ⁇ B) of the conductive paste at 25°C and 0.5 rpm to the viscosity ( ⁇ A) at 25°C and 5 rpm of the conductive paste is 1.5 or more and 4.5 or less.
  • the thixotropic index is preferably 2.0 or more, more preferably 2.2 or more, even more preferably 2.5 or more, and preferably 4.2 or less, more preferably 4.0 or less, even more preferably 3.8 or less.
  • the thixotropic index is equal to or more than the lower limit, the chip positional deviation can be more effectively prevented even when the transported object is transported vertically in the manufacturing process. If the thixotropic index is equal to or less than the upper limit, the conductive paste can be arranged on the fine wiring with higher precision.
  • the viscosity ( ⁇ A) of the conductive paste at 25°C and 5 rpm and the viscosity ( ⁇ B) of the conductive paste at 25°C and 0.5 rpm can be measured, for example, using an E-type viscometer.
  • E-type viscometer examples include the TV22 viscometer manufactured by Toki Sangyo Co., Ltd.
  • the viscosity ( ⁇ C) of the composition excluding the conductive filler in the conductive paste at 25°C and 5 rpm is preferably 5 Pa ⁇ s or more and 50 Pa ⁇ s or less.
  • the viscosity ( ⁇ C) is preferably 7 Pa ⁇ s or more, more preferably 8 Pa ⁇ s or more, even more preferably 10 Pa ⁇ s or more, and is preferably 45 Pa ⁇ s or less, more preferably 43 Pa ⁇ s or less, and even more preferably 40 Pa ⁇ s or less. If the viscosity ( ⁇ C) is equal to or greater than the lower limit, the chip can be more effectively prevented from shifting in position even when the transported object is transported vertically in the manufacturing process. If the viscosity ( ⁇ C) is equal to or less than the upper limit, the conductive paste can be placed on the fine wiring with even greater precision.
  • the viscosity ( ⁇ C) of the composition of the conductive paste excluding the conductive filler at 25°C and 5 rpm can be measured, for example, by the following methods.
  • An example of the E-type viscometer is the TV22 viscometer manufactured by Toki Sangyo Co., Ltd.
  • the viscosity ( ⁇ D) of the conductive paste at 25° C. and a shear rate of 0.1 sec ⁇ 1 is preferably 5 Pa ⁇ s or more, and preferably 50 Pa ⁇ s or less. If the viscosity ( ⁇ D) is equal to or more than the lower limit, the chip positional deviation can be more effectively prevented even when the transported object is transported in the vertical direction in the manufacturing process. If the viscosity ( ⁇ D) is equal to or less than the upper limit, the conductive paste can be arranged on the fine wiring with higher accuracy.
  • the viscosity ( ⁇ E) of the conductive paste at 25° C. and a shear rate of 0.01 sec ⁇ 1 is preferably 15 Pa ⁇ s or more, and preferably 200 Pa ⁇ s or less. If the viscosity ( ⁇ E) is equal to or more than the lower limit, the chip positional deviation can be more effectively prevented even when the transported object is transported in the vertical direction in the manufacturing process. If the viscosity ( ⁇ E) is equal to or less than the upper limit, the conductive paste can be arranged on the fine wiring with higher accuracy.
  • the viscosity ( ⁇ F) of the conductive paste at 25° C. and a shear rate of 0.001 sec ⁇ 1 is preferably 20 Pa ⁇ s or more, and preferably 10,000 Pa ⁇ s or less. If the viscosity ( ⁇ F) is equal to or more than the lower limit, the chip positional deviation can be more effectively prevented even when the transported object is transported in the vertical direction in the manufacturing process. If the viscosity ( ⁇ F) is equal to or less than the upper limit, the conductive paste can be arranged on the fine wiring with higher accuracy.
  • the above viscosities ( ⁇ D), ( ⁇ E), and ( ⁇ F) can be measured using a rheometer (e.g., Type: HAAKE, manufactured by Thermo Scientific).
  • a rheometer e.g., Type: HAAKE, manufactured by Thermo Scientific.
  • the conductive paste has good adhesive properties.
  • the conductive paste is suitable for use as an adhesive.
  • the conductive paste is particularly suitable for use in bonding a substrate and a chip.
  • the conductive paste is preferably an anisotropic conductive paste.
  • the conductive paste is preferably used for electrically connecting electrodes.
  • the conductive paste is preferably used for obtaining a connection structure.
  • the conductive paste is preferably used for obtaining electronic components.
  • the conductive paste is particularly preferably used for obtaining an RFID inlay (use of the conductive paste for obtaining an RFID inlay).
  • the conductive paste is preferably used for bonding and connecting a chip having an electrode on its surface to a substrate having wiring (antenna pattern) on its surface (use of the conductive paste for bonding and connecting a chip having an electrode on its surface to a substrate having wiring (antenna pattern) on its surface).
  • the conductive paste is preferably used by being applied to a substrate having a surface tension of 30 mN/m or more and 50 mN/m or less (use of the conductive paste on a substrate having a surface tension of 30 mN/m or more and 50 mN/m or less).
  • the conductive paste is preferably used to bond a chip having a planar area of 0.50 mm2 or less (use of the conductive paste for bonding a chip having a planar area of 0.50 mm2 or less).
  • the conductive paste is preferably thermosetting.
  • the conductive paste is preferably a thermosetting conductive paste, and more preferably a thermosetting anisotropic conductive paste.
  • (meth)acrylate refers to acrylate and methacrylate.
  • (meth)acrylic refers to acrylic and methacrylic.
  • (meth)acryloyl refers to acryloyl and methacryloyl.
  • the curable compound includes a thermosetting compound and a photocurable compound.
  • the curable compound is preferably a thermosetting compound.
  • the thermosetting compound is a compound that can be cured by heating.
  • the thermosetting compound includes a (meth)acrylic compound, an oxetane compound, an epoxy compound, an episulfide compound, a phenol compound, an amino compound, an unsaturated polyester compound, a polyurethane compound, a silicone compound, and a polyimide compound.
  • the curable compound may be used alone or in combination of two or more kinds.
  • the curable compound preferably contains an epoxy compound or a (meth)acrylic compound, and more preferably contains a (meth)acrylic compound. From the viewpoint of increasing the adhesiveness, the curable compound more preferably contains a compound having a (meth)acryloyl group ((meth)acrylate).
  • the (meth)acrylic compound may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate.
  • the polyfunctional (meth)acrylate may be a difunctional (meth)acrylate, a trifunctional (meth)acrylate, or a tetrafunctional or higher (meth)acrylate.
  • the (meth)acrylic compound may have 100 or less (meth)acryloyl groups, 50 or less, or 10 or less. Only one type of the (meth)acrylic compound may be used, or two or more types may be used in combination.
  • the above monofunctional (meth)acrylates include 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, isobutyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, octyl/decyl (meth)acrylate, tridecyl (meth)acrylate, nonyl (meth)acrylate, caprolactone (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxene
  • acrylates include methyl acrylate (meth)acrylate, methoxyethy
  • polyfunctional (meth)acrylates include 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol (meth)acrylate, 1,9-nonanediol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, tetraethylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol (400) di(meth)acrylate, dipropylene glycol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, dodecanediol di(meth)acrylate, Examples of such acrylates include polyethylene glycol (600) di(meth)acrylate, 1,
  • the (meth)acrylic compound contains a polymerizable monomer having one (meth)acryloyl group (hereinafter sometimes referred to as "polymerizable monomer (A)").
  • the curable compound contains a polymerizable monomer having one (meth)acryloyl group (polymerizable monomer (A)).
  • the (A) polymerizable monomer is a monofunctional (meth)acrylate.
  • the (A) polymerizable monomer is a polymerizable component that can be homopolymerized or copolymerized.
  • the (A) polymerizable monomer has an aromatic skeleton or an alicyclic skeleton.
  • the (A) polymerizable monomer may have an aromatic skeleton, an alicyclic skeleton, or both an aromatic skeleton and an alicyclic skeleton.
  • the (A) polymerizable monomer may include a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton.
  • Examples of the (A) polymerizable monomer having an aromatic skeleton include 2-phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, ethoxylated (4) nonylphenol (meth)acrylate, and alkoxylated phenol (meth)acrylate.
  • Examples of the polymerizable monomer (A) having an alicyclic skeleton include cyclohexyl (meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, isobornyl (meth)acrylate, 4-tert-butylcyclohexanol, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, pentamethylpiperidyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, acrylomorpholine, and 3,3,5-trimethylcyclohexyl (meth)acrylate.
  • the polymerizable monomer (A) is isobornyl (meth)acrylate.
  • the molecular weight of the (A) polymerizable monomer is preferably 50 or more, more preferably 100 or more, even more preferably 150 or more, and particularly preferably 200 or more, and is preferably 1000 or less, more preferably less than 1000, even more preferably 900 or less, particularly preferably 800 or less, and most preferably 700 or less.
  • the viscosity of the conductive paste can be adjusted to a suitable range, and the conductive reliability of the resulting connection structure can be further improved.
  • the molecular weight of the (A) polymerizable monomer means the molecular weight that can be calculated from the structural formula of the (A) polymerizable monomer when the structural formula of the (A) polymerizable monomer can be identified.
  • the molecular weight means the weight average molecular weight.
  • the weight average molecular weight indicates the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC). Since the (A) polymerizable monomer has a relatively small molecular weight, the structural formula can generally be identified.
  • the weight average molecular weight can be measured using the following measuring device and under the following measuring conditions.
  • Measurement device "Waters GPC System (Waters 2690 + Waters 2414 (RI))" manufactured by Japan Waters Corporation Column: Shodex GPC LF-G x 1, Shodex GPC LF-804 x 2 Mobile phase: THF 1.0 mL/min Sample concentration: 5 mg/mL Detector: Refractive Index Detector (RID) Standard material: polystyrene (manufactured by TOSOH Corporation, weight average molecular weight: 620 to 590,000)
  • the viscosity of the polymerizable monomer (A) at 25°C is preferably 1 mPa ⁇ s or more, more preferably 2 mPa ⁇ s or more, and preferably 50 mPa ⁇ s or less, more preferably 45 mPa ⁇ s or less.
  • the viscosity of the polymerizable monomer (A) at 25°C is equal to or more than the lower limit and equal to or less than the upper limit, the conductive paste can be arranged on the fine wiring with even higher precision, and the wettability to the substrate can be improved.
  • the viscosity of the polymerizable monomer (A) at 25°C can be measured, for example, using an E-type viscometer at 25°C and 5 rpm.
  • E-type viscometer examples include the TV22 viscometer manufactured by Toki Sangyo Co., Ltd.
  • the (meth)acrylic compound may contain a (meth)acrylic compound other than the (A) polymerizable monomer.
  • the (meth)acrylic compound other than the (A) polymerizable monomer may be used alone or in combination of two or more.
  • the (meth)acrylic compound other than the (A) polymerizable monomer preferably has two or more (meth)acryloyl groups.
  • the (meth)acrylic compound other than the (A) polymerizable monomer is preferably a polyfunctional (meth)acrylate.
  • the (meth)acrylic compound other than the (A) polymerizable monomer may have two (meth)acryloyl groups, two or more, three or more, four or more, or ten or less.
  • the (meth)acrylic compound other than the (A) polymerizable monomer contains urethane (meth)acrylate.
  • the molecular weight of the urethane (meth)acrylate is preferably 1000 or more, more preferably 1500 or more, even more preferably 2000 or more, even more preferably 3000 or more, and particularly preferably 5000 or more, and is preferably 30000 or less, more preferably 25000 or less, even more preferably 20000 or less, and particularly preferably 18000 or less.
  • the adhesiveness can be further improved and the electrical conductivity reliability can be further improved.
  • the molecular weight of the urethane (meth)acrylate refers to the molecular weight that can be calculated from the structural formula of the urethane (meth)acrylate when the structural formula of the urethane (meth)acrylate can be identified.
  • the molecular weight refers to the weight average molecular weight.
  • the weight average molecular weight refers to the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).
  • the molecular weight of the urethane (meth)acrylate is preferably the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).
  • the weight average molecular weight can be measured using the following measuring device and under the following measuring conditions.
  • Measurement device "Waters GPC System (Waters 2690 + Waters 2414 (RI))" manufactured by Japan Waters Corporation Column: Shodex GPC LF-G x 1, Shodex GPC LF-804 x 2 Mobile phase: THF 1.0 mL/min Sample concentration: 5 mg/mL Detector: Refractive Index Detector (RID) Standard material: polystyrene (manufactured by TOSOH Corporation, weight average molecular weight: 620 to 590,000)
  • the viscosity of the urethane (meth)acrylate at 25°C can be measured, for example, using an E-type viscometer at 25°C and 5 rpm.
  • E-type viscometer examples include the TV22 viscometer manufactured by Toki Sangyo Co., Ltd.
  • the content of the curable compound in the conductive paste (100% by weight) is preferably 15% by weight or more, more preferably 20% by weight or more, and preferably 60% by weight or less, more preferably 55% by weight or less, and even more preferably 50% by weight or less.
  • the content of the curable compound is equal to or more than the lower limit and equal to or less than the upper limit, the adhesiveness can be further improved and the electrical conductivity reliability can be further improved.
  • the content of the polymerizable monomer (A) is preferably 10% by weight or more, more preferably 15% by weight or more, and preferably 50% by weight or less, more preferably 45% by weight or less, even more preferably 40% by weight or less, and particularly preferably 35% by weight or less.
  • the content of the polymerizable monomer (A) is equal to or more than the lower limit and equal to or less than the upper limit, the electrical conductivity reliability of the resulting connection structure can be further improved.
  • the content of the polymerizable monomer (A) indicates the total content of the polymerizable monomer having an aromatic skeleton and the polymerizable monomer having an alicyclic skeleton.
  • the content of the polymerizable monomer (A) is preferably 10% by weight or more, more preferably 15% by weight or more, and preferably 50% by weight or less, more preferably 45% by weight or less.
  • the electrical conductivity reliability can be further improved.
  • the content of the polymerizable monomer indicates the total content of the polymerizable monomer having an aromatic skeleton and the polymerizable monomer having an alicyclic skeleton.
  • the content of the urethane (meth)acrylate in 100% by weight of the curable compound is preferably 15% by weight or more, more preferably 20% by weight or more, and preferably 50% by weight or less, more preferably 45% by weight or less.
  • the adhesiveness can be increased and the electrical conductivity reliability can be further improved.
  • the total content of the polymerizable monomer (A) and the urethane (meth)acrylate is preferably 20% by weight or more, more preferably 40% by weight or more, and preferably 90% by weight or less, more preferably 80% by weight or less.
  • the viscosity of the conductive paste can be adjusted to a suitable range, and the adhesiveness can be increased and the electrical conductivity reliability can be further improved.
  • the content of the (A) polymerizable monomer is preferably 15% by weight or more, more preferably 20% by weight or more, and preferably 55% by weight or less, more preferably 50% by weight or less, out of a total of 100% by weight of the (A) polymerizable monomer and the urethane (meth)acrylate.
  • the content of the (A) polymerizable monomer is equal to or more than the lower limit and equal to or less than the upper limit, the viscosity of the conductive paste can be adjusted to a suitable range, and the adhesiveness can be improved and the electrical reliability can be further improved.
  • the content of the (A) polymerizable monomer indicates the total content of the polymerizable monomer having an aromatic skeleton and the polymerizable monomer having an alicyclic skeleton.
  • the conductive paste includes a plurality of conductive fillers.
  • the conductive fillers are not particularly limited.
  • the conductive fillers may be conductive particles or carbon fibers.
  • "including a plurality of conductive fillers” means that the conductive paste includes two or more conductive fillers. Only one type of the conductive filler may be used, or two or more types may be used in combination.
  • the specific gravity of the conductive filler is 1.5 or more and 4.0 or less.
  • the specific gravity of the conductive filler is preferably 1.8 or more, more preferably 2.0 or more, and preferably 3.8 or less, more preferably 3.5 or less.
  • the specific gravity of the conductive filler is equal to or more than the lower limit and equal to or less than the upper limit, uneven distribution of the conductive filler in the conductive paste can be prevented even when the transported object is transported vertically in the manufacturing process, and the electrical conductivity reliability of the resulting connection structure can be further improved.
  • the specific gravity of the conductive filler can be measured, for example, using the AccuPyc II 1340 manufactured by Micrometrics.
  • the shape of the conductive filler is not particularly limited.
  • the shape of the conductive filler may be spherical, may be a shape other than spherical, or may be flat, etc.
  • the conductive filler is preferably a conductive particle.
  • the conductive particle may be a solder particle or a metal particle.
  • the metal particle may be a metal powder.
  • the conductive particle may include a base particle and a conductive portion disposed on the surface of the base particle. From the viewpoint of further increasing the reliability of conduction, the conductive particle preferably includes a base particle and a conductive portion disposed on the surface of the base particle.
  • the particle diameter of the conductive particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, even more preferably 2 ⁇ m or more, and is preferably 100 ⁇ m or less, more preferably 30 ⁇ m or less, even more preferably 10 ⁇ m or less.
  • the particle diameter of the conductive particles is equal to or more than the lower limit and equal to or less than the upper limit, the electrical conductivity reliability can be further improved.
  • the particle diameter of the conductive particles is preferably an average particle diameter, and more preferably a number average particle diameter.
  • the average particle diameter of the conductive particles can be determined, for example, by observing 50 random conductive particles with an electron microscope or optical microscope and calculating the average particle diameter of each conductive particle, or by performing laser diffraction particle size distribution measurement.
  • the particle diameter of the conductive particles is measured by observing 50 arbitrary conductive particles with an electron microscope or optical microscope, the measurement can be performed, for example, as follows.
  • the conductive particles are added to "Technovit 4000" manufactured by Kulzer so that the content of the conductive particles is 30% by weight, and dispersed to prepare an embedding resin body for conductive particle inspection.
  • a cross section of the conductive particle is cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the conductive particles dispersed in the embedding resin body for conductive particle inspection.
  • the image magnification is set to 25,000 times, 50 conductive particles are randomly selected, and each conductive particle is observed.
  • the circle equivalent diameter of each conductive particle is measured, and the arithmetic average of the measured diameters is determined as the particle diameter of the conductive particle.
  • the coefficient of variation (CV value) of the particle diameter of the conductive particles is preferably 10% or less, more preferably 5% or less.
  • the coefficient of variation of the particle diameter of the conductive particles is equal to or less than the upper limit, the reliability of electrical conductivity can be further improved.
  • the coefficient of variation (CV value) of the particle diameter of the conductive particles may be 0% or more, or 1% or more.
  • CV value The above coefficient of variation (CV value) can be measured as follows.
  • CV value (%) ( ⁇ /Dn) ⁇ 100 ⁇ : Standard deviation of the particle diameter of the conductive particles Dn: Average particle diameter of the conductive particles
  • the conductive filler content in the 100% by weight conductive paste is 1.0% by weight or more and 15% by weight or less.
  • the conductive filler content in the 100% by weight conductive paste is preferably 2.0% by weight or more, more preferably 5.0% by weight or more, and preferably 13% by weight or less, more preferably 10% by weight or less.
  • the electrical conductivity reliability can be further improved.
  • the content of the conductive filler relative to 100 parts by weight of the curable compound in the conductive paste is preferably 2.0 parts by weight or more, more preferably 3.0 parts by weight or more, even more preferably 5.0 parts by weight or more, and particularly preferably 7.0 parts by weight or more.
  • the content of the conductive filler relative to 100 parts by weight of the curable compound in the conductive paste is preferably 35 parts by weight or less, more preferably 30 parts by weight or less, even more preferably 25 parts by weight or less, and particularly preferably 20 parts by weight or less.
  • the conductive filler preferably contains a metal.
  • the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, ruthenium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, as well as alloys thereof.
  • Tin-doped indium oxide (ITO) may also be used as the metal. Only one of the above metals may be used, or two or more of them may be used in combination.
  • the conductive filler preferably contains a tin-containing alloy, nickel, palladium, ruthenium, silver, copper or gold, and more preferably contains nickel or palladium. From the viewpoint of increasing the corrosion resistance of the conductive filler and maintaining high electrical conductivity reliability, the conductive filler preferably contains nickel or gold, and more preferably contains nickel. From the viewpoint of increasing the corrosion resistance of the conductive filler and maintaining high electrical conductivity reliability, it is particularly preferable that the conductive filler contains nickel on the outer surface.
  • the conductive particles are metal particles
  • examples of the metal particles include silver, copper, nickel, silicon, gold, titanium, and alloys such as solder. From the viewpoint of more effectively increasing the reliability of electrical conduction, it is preferable that the material of the metal particles contains nickel or a nickel alloy, and it is more preferable that the material of the metal particles is nickel or a nickel alloy. From the viewpoint of more effectively increasing the reliability of electrical conduction, it is preferable that the outer surface portion of the metal particles contains nickel or a nickel alloy.
  • the conductive particle which includes a base particle and a conductive portion disposed on the surface of the base particle.
  • the base particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles.
  • the base particles are preferably base particles other than metal particles, and more preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles.
  • the base particles may be core-shell particles having a core and a shell disposed on the surface of the core.
  • the core may be an organic core, and the shell may be an inorganic shell.
  • the above-mentioned base particles are more preferably resin particles or organic-inorganic hybrid particles, and may be either resin particles or organic-inorganic hybrid particles. By using these preferred base particles, the effects of the present invention are more effectively exhibited.
  • the material for 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; polyalkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether sulfone, divinylbenzene polymer, and polymers obtained by polymerizing one or more of various polymeriz
  • the divinylbenzene polymer may be a divinylbenzene copolymer.
  • examples of the divinylbenzene copolymer include divinylbenzene-styrene copolymer and divinylbenzene-(meth)acrylic acid ester copolymer.
  • the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having multiple ethylenically unsaturated groups.
  • the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer.
  • non-crosslinkable monomers include styrene-based monomers such as styrene and ⁇ -methylstyrene; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; alkyl (meth)acrylate compounds such as 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 (meth)acrylate, and isobornyl (meth)acrylate; 2-hydroxyethyl Examples of such monomers include oxygen-containing (meth)acrylate compounds such as (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and
  • crosslinkable monomers include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propane tri ...
  • suitable (meth)acrylates include polyfunctional (meth)acrylate compounds such as propylene glycol di(meth)acrylate, (poly)tetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate; and silane-containing monomers such as triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, ⁇ -(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.
  • polyfunctional (meth)acrylate compounds such as propylene glycol di(meth)acrylate, (poly)tetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate
  • silane-containing monomers such as triallyl (iso)cyanurate, triallyl
  • the resin particles can be obtained by polymerizing the polymerizable monomer having the ethylenically unsaturated group by a known method. Examples of such methods include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of using non-crosslinked seed particles to swell and polymerize the monomer together with a radical polymerization initiator.
  • the base particles are inorganic particles other than metal particles or organic-inorganic hybrid particles
  • examples of the inorganic material of the base particles include silica, alumina, barium titanate, zirconia, and carbon black. It is preferable that the inorganic material is not a metal.
  • the particles formed from silica are not particularly limited, but examples include particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, and then baking the particles as necessary.
  • the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from a crosslinked alkoxysilyl polymer and an acrylic resin.
  • the organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core.
  • the core is preferably an organic core.
  • the shell is preferably an inorganic shell.
  • the base particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell disposed on the surface of the organic core.
  • Examples of the organic core material include the resin particle materials mentioned above.
  • the material of the inorganic shell may be any of the inorganic substances listed as the material of the base particle described above.
  • the material of the inorganic shell is preferably silica.
  • the inorganic shell is preferably formed by forming a shell-like material from a metal alkoxide on the surface of the core by a sol-gel method, and then firing the shell-like material.
  • the metal alkoxide is preferably a silane alkoxide.
  • the inorganic shell is preferably formed from a silane alkoxide.
  • the base particles are metal particles
  • examples of the metal particles include silver, copper, nickel, silicon, gold, titanium, and alloys such as solder.
  • the particle diameter of the base particles is preferably 0.01 ⁇ m or more, more preferably 0.05 ⁇ m or more, even more preferably 0.5 ⁇ m or more, even more preferably 1 ⁇ m or more, and particularly preferably 3 ⁇ m or more, and is preferably 50 ⁇ m or less, more preferably 30 ⁇ m or less, even more preferably 20 ⁇ m or less, and particularly preferably 10 ⁇ m or less.
  • the particle diameter of the base particles is equal to or greater than the lower limit, the electrical conductivity reliability is further increased.
  • aggregation is less likely to occur, and aggregated conductive particles are less likely to be formed.
  • the conductive particles are easily compressed sufficiently, and the connection resistance between the electrodes connected via the conductive particles can be further effectively reduced.
  • the particle diameter of the base particles is preferably an average particle diameter, and more preferably a number average particle diameter.
  • the number average particle diameter of the base particles can be measured, for example, as follows.
  • the conductive particles are added to "Technovit 4000" manufactured by Kulzer so that the content of the conductive particles is 30% by weight, and dispersed to prepare an embedded resin body for inspecting base particles.
  • a cross section of the conductive particles dispersed in the embedded resin body for inspecting base particles is cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the base particle in the conductive particles dispersed in the embedded resin body for inspecting base particles.
  • IM4000 manufactured by Hitachi High-Technologies Corporation
  • the image magnification is set to 25,000 times, 50 conductive particles are randomly selected, and the base particle of each conductive particle is observed. The particle diameter of the base particle in each conductive particle is measured, and the arithmetic average is taken to determine the average particle diameter of the base particles.
  • FE-SEM field emission scanning electron microscope
  • the conductive portion preferably contains a metal.
  • the metal constituting the conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, ruthenium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, as well as alloys thereof.
  • tin-doped indium oxide (ITO) may be used as the metal. Only one of the metals may be used, or two or more of them may be used in combination. From the viewpoint of further reducing the connection resistance between the electrodes, an alloy containing tin, nickel, palladium, ruthenium, silver, copper, or gold is preferred, and nickel or palladium is more preferred.
  • the conductive portion contains nickel, and it is even more preferable that the outer surface portion of the conductive portion contains nickel.
  • the nickel content in 100% by weight of the nickel-containing conductive part is preferably 10% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, even more preferably 70% by weight or more, and particularly preferably 90% by weight or more.
  • the nickel content in 100% by weight of the nickel-containing conductive part may be 99% by weight or less, 90% by weight or less, or 70% by weight or less.
  • the conductive portion may be formed of one layer.
  • the conductive portion may be formed of multiple layers. That is, the conductive portion may have a laminated structure of two or more layers.
  • the metal constituting the outermost layer is preferably an alloy containing gold, silver, nickel, palladium, ruthenium, copper, or tin, and is more preferably nickel.
  • the connection resistance between the electrodes is further reduced.
  • the method for forming the conductive portion on the surface of the base particle is not particularly limited.
  • Examples of the method for forming the conductive portion include electroless plating, electroplating, physical collision, mechanochemical reaction, physical vapor deposition or physical adsorption, and coating the surface of the base particle with a metal powder or a paste containing a metal powder and a binder.
  • the method for forming the conductive portion is preferably electroless plating, electroplating, or physical collision.
  • Examples of the physical vapor deposition method include vacuum vapor deposition, ion plating, and ion sputtering.
  • a sheeter composer manufactured by Tokuju Kosakusho Co., Ltd. is used.
  • the thickness of the conductive portion is preferably 0.005 ⁇ m or more, more preferably 0.01 ⁇ m or more, and is preferably 10 ⁇ m or less, more preferably 1 ⁇ m or less, and even more preferably 0.3 ⁇ m or less.
  • the thickness of the conductive portion is equal to or greater than the lower limit and equal to or less than the upper limit, sufficient conductivity is obtained, and the conductive particles do not become too hard, allowing the conductive particles to be sufficiently deformed when connected.
  • the thickness of the conductive portion of the outermost layer is preferably 0.001 ⁇ m or more, more preferably 0.01 ⁇ m or more, and preferably 0.5 ⁇ m or less, more preferably 0.1 ⁇ m or less.
  • the thickness of the conductive portion of the outermost layer is equal to or greater than the lower limit and equal to or less than the upper limit, the conductive portion of the outermost layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes can be sufficiently low.
  • the thickness of the conductive portion can be measured, for example, by observing the cross-section of the conductive particle using a transmission electron microscope (TEM).
  • TEM transmission electron microscope
  • the conductive particles preferably have a plurality of protrusions on the outer surface of the conductive part.
  • An oxide film is often formed on the surface of the electrodes connected by the conductive particles.
  • the oxide film can be effectively removed by the protrusions by arranging the conductive particles between the electrodes and pressing them together. This allows the electrodes and the conductive part to be in more reliable contact, and the connection resistance between the electrodes is further reduced.
  • the protrusions of the conductive particles can effectively remove the filler between the conductive particles and the electrodes. This further increases the reliability of the conduction between the electrodes.
  • Methods for forming the above-mentioned protrusions include a method in which a core material is attached to the surface of a base particle and then a conductive portion is formed by electroless plating, and a method in which a conductive portion is formed on the surface of a base particle by electroless plating, then a core material is attached, and then a conductive portion is formed by electroless plating.
  • a method may be used in which, without using the above-mentioned core material, a conductive portion is formed on the base particle by electroless plating, plating is deposited in the form of protrusions on the surface of the conductive portion, and then a conductive portion is formed by electroless plating.
  • Methods for attaching a core substance to the surface of a base particle include, for example, a method in which a core substance is added to a dispersion liquid of the base particle, and the core substance is accumulated and attached to the surface of the base particle by van der Waals forces, and a method in which a core substance is added to a container containing the base particle, and the core substance is attached to the surface of the base particle by mechanical action such as rotating the container.
  • the method for attaching a core substance to the surface of a base particle is preferably a method in which the core substance is accumulated and attached to the surface of the base particle in the dispersion liquid.
  • the materials constituting the core material include conductive materials and non-conductive materials.
  • the conductive materials include, for example, conductive non-metals such as metals, metal oxides, and graphite, and conductive polymers.
  • the conductive polymers include polyacetylene.
  • the non-conductive materials include silica, alumina, titanium oxide, tungsten carbide, and zirconia. From the viewpoint of further increasing the reliability of electrical conduction between the electrodes, it is preferable that the core material is a metal.
  • the metal is not particularly limited.
  • the metal include gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, as well as alloys composed of two or more metals, such as tin-lead alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide.
  • the metal is preferably nickel, copper, silver, or gold.
  • the metal may be the same as or different from the metal constituting the conductive portion.
  • the shape of the core material is not particularly limited.
  • the core material is preferably in the form of a mass.
  • Examples of the core material include particulate masses, agglomerates of multiple microparticles, and amorphous masses.
  • the particle diameter (average particle diameter) of the core material is preferably 0.001 ⁇ m or more, more preferably 0.05 ⁇ m or more, and preferably 0.9 ⁇ m or less, more preferably 0.2 ⁇ m or less.
  • the particle diameter of the core material is equal to or greater than the lower limit and equal to or less than the upper limit, the connection resistance between the electrodes can be effectively reduced.
  • the particle diameter of the core substance is preferably an average particle diameter, and more preferably a number average particle diameter.
  • the particle diameter of the core substance can be determined, for example, by observing 50 random core substances with an electron microscope or optical microscope and calculating the average particle diameter of each core substance, or by performing laser diffraction particle size distribution measurement.
  • the curing agent is preferably a polymerization initiator.
  • the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator.
  • the polymerization initiator may be used alone or in combination of two or more kinds.
  • the polymerization initiator contains a thermal polymerization initiator.
  • the thermal polymerization initiator preferably contains a thermal radical polymerization initiator, and is preferably a thermal radical polymerization initiator.
  • Examples of the thermal radical polymerization initiator include a peroxide radical polymerization initiator, an azo radical polymerization initiator, and a redox radical polymerization initiator.
  • azo radical polymerization initiator examples include azobisisobutyronitrile, azobiscyclohexanecarbonitrile, and azobisdimethylvaleronitrile.
  • the above-mentioned peroxide-based radical polymerization initiators include diacyl-based radical polymerization initiators, peroxyester-based radical polymerization initiators, dialkyl-based radical polymerization initiators, percarbonate-based radical polymerization initiators, and ketone peroxide-based radical polymerization initiators.
  • the above-mentioned diacyl-based radical polymerization initiators include lauroyl peroxide and benzoyl peroxide.
  • the above-mentioned peroxyester-based radical polymerization initiators include t-butyl peroxybenzoate, t-butyl peroxyacetate, t-butyl peroxypivalate, and t-butyl peroxy-2-ethylhexanoate.
  • the above-mentioned dialkyl-based radical polymerization initiators include dicumyl peroxide and di-t-butyl peroxide.
  • the above-mentioned percarbonate-based radical polymerization initiators include diisopropyl peroxydicarbonate.
  • the above-mentioned ketone peroxide-based radical polymerization initiators include methyl ethyl ketone peroxide.
  • the redox radical polymerization initiator includes, for example, a peroxide and a reducing agent or a metal-containing compound.
  • Specific examples of the redox radical polymerization initiator include a mixture of benzoyl peroxide and organic amines, a mixture of the peroxyester radical polymerization initiator and a reducing agent such as mercaptans, and a mixture of methyl ethyl ketone peroxide and an organic cobalt salt.
  • the polymerization initiator contains a peroxide-based radical polymerization initiator.
  • the content of the curing agent (polymerization initiator) in 100% by weight of the conductive paste is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, even more preferably 0.5% by weight or more, and is preferably 5% by weight or less, more preferably 4% by weight or less, even more preferably 3% by weight or less.
  • the content of the curing agent (polymerization initiator) relative to 100 parts by weight of the curable compound in the conductive paste is preferably 0.3 parts by weight or more, more preferably 0.5 parts by weight or more, even more preferably 0.7 parts by weight or more, and is preferably 6 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 4 parts by weight or less.
  • content of the curing agent (polymerization initiator) is equal to or more than the lower limit and equal to or less than the upper limit, reactivity and storage stability can be improved.
  • the conductive paste may contain components other than the curable compound, the curing agent, and the plurality of conductive fillers, such as a solvent, an inorganic filler, an organic filler, a colorant, a polymerization inhibitor, a chain transfer agent, an antioxidant, an ultraviolet absorber, a defoaming agent, a leveling agent, a surfactant, a slip agent, an antiblocking agent, a wax, a masking agent, a deodorant, a fragrance, a preservative, an antibacterial agent, an antistatic agent, and an adhesion imparting agent.
  • a solvent such as a solvent, an inorganic filler, an organic filler, a colorant, a polymerization inhibitor, a chain transfer agent, an antioxidant, an ultraviolet absorber, a defoaming agent, a leveling agent, a surfactant, a slip agent, an antiblocking agent, a wax, a masking agent, a deodorant, a fragrance, a pre
  • the RFID inlay according to the present invention comprises a substrate having wiring on its surface, a chip having electrodes on its surface, and an adhesive portion bonding the substrate and the chip.
  • the material of the adhesive portion is the conductive paste described above.
  • the wiring and the electrodes are electrically connected by the conductive filler in the adhesive portion.
  • FIG. 1 is a cross-sectional view showing a schematic diagram of an RFID inlay using a conductive paste according to a first embodiment of the present invention.
  • the RFID inlay 81 shown in FIG. 1 comprises a substrate 82 having wiring on its surface, a chip 83 having electrodes on its surface, and an adhesive portion 84 that bonds the substrate 82 and the chip 83.
  • the material of the adhesive portion 84 is a conductive paste containing conductive filler 1.
  • the adhesive portion 84 is formed from a conductive paste containing conductive filler 1. It is preferable that the adhesive portion 84 is formed by hardening the conductive paste containing conductive filler 1.
  • the substrate 82 has wiring 82a on its surface (upper surface).
  • the chip 83 has an electrode 83a on its surface (lower surface).
  • the wiring 82a and the electrode 83a are electrically connected by the conductive filler 1 in the adhesive portion 84.
  • the manufacturing method of the RFID inlay according to the present invention comprises the following steps (1) to (3): (1) A first arrangement step of arranging the above-mentioned conductive paste on the surface of a substrate having wiring on its surface. (2) A second arrangement step of arranging a chip having an electrode on its surface on the surface of the conductive paste opposite the substrate. (3) A bonding step of forming an adhesive part that bonds the substrate and the chip with the conductive paste by heating and pressurizing the conductive paste, and electrically connecting the wiring and the electrodes with the conductive filler in the adhesive part.
  • a specific conductive paste is used, which can improve the adhesion between the substrate and the chip.
  • a specific conductive paste is used, which can be arranged on the wiring with high precision.
  • a specific conductive paste is used, which can prevent the chip from shifting in position and the conductive filler from being unevenly distributed, even when the transported object is transported vertically in the manufacturing process. As a result, the reliability of conductivity can be improved.
  • the conductive paste may be arranged on the surface of the substrate, or the chip and the conductive paste may be arranged on the surface of the substrate.
  • the substrate is long and that the RFID inlay is manufactured by transporting the long substrate using a roll-to-roll method in the first arrangement step, the second arrangement step, and the bonding step.
  • multiple RFID inlays can be manufactured continuously, and the manufacturing efficiency of the RFID inlay can be further improved.
  • the substrate in the first arrangement step, the second arrangement step, and the bonding step, the substrate may be transported horizontally, vertically, or both horizontally and vertically by a roll-to-roll method.
  • the substrate in the first arrangement step, the second arrangement step, and the bonding step, the substrate may be transported diagonally by a roll-to-roll method.
  • the conductive paste described above since the conductive paste described above is used, even when the transported object is transported vertically by a roll-to-roll method, it is possible to prevent the chip from being misaligned and the conductive filler from being unevenly distributed.
  • the substrate may be transported with the conductive paste disposed on the surface of the substrate, or with the chip and the conductive paste disposed thereon.
  • the conductive paste can be applied by, for example, applying it with a dispenser, screen printing, or ejecting it with an inkjet device.
  • the heating temperature in the bonding process is preferably 100°C or higher, more preferably 150°C or higher, and is preferably 400°C or lower, more preferably 300°C or lower, and even more preferably 250°C or lower. If the heating temperature in the bonding process is equal to or higher than the lower limit and equal to or lower than the upper limit, good electrical connection between the chip and the wiring (antenna pattern) can be achieved.
  • the applied pressure in the bonding process is preferably 0.5 N or more, more preferably 1 N or more, and is preferably 3.5 N or less, more preferably 3 N or less, and even more preferably 2.5 N or less.
  • the applied pressure in the bonding process is equal to or more than the lower limit and equal to or less than the upper limit, the adhesion between the substrate and the chip can be improved, and the electrical conductivity reliability can be improved.
  • the heating and pressurizing time in the bonding process is not particularly limited.
  • the heating and pressurizing time in the bonding process may be 2 seconds or more, 15 seconds or less, or 10 seconds or less.
  • the RFID inlay may be cut to a predetermined size as necessary, or may be cut before use. It is preferable that a plurality of the chips are adhered to a long substrate by a plurality of the adhesive parts. A plurality of laminates of the chips and the adhesive parts may be arranged on the long substrate. In the first arrangement step, it is preferable that the conductive paste is arranged at a plurality of locations on the surface of the long substrate. In the second arrangement step, it is preferable that the chips are arranged using a plurality of chips on the surface opposite the substrate side of each of the conductive pastes arranged at a plurality of locations. After the chips are adhered to the long substrate by the adhesive parts, the long substrate may be cut.
  • the substrate is not particularly limited.
  • the substrate is preferably a circuit board.
  • the circuit board include a resin film, a flexible printed circuit board, a rigid-flexible board, a glass board, and a paper board.
  • the substrate may be a resin board, a glass board, or a paper board.
  • the substrate has wiring (antenna pattern) on its surface.
  • the substrate has wiring (antenna pattern) formed on its surface.
  • the substrate preferably has a base material and wiring (antenna pattern) disposed on the surface of the base material.
  • the substrate may be made of resin, glass, paper, or the like.
  • the resin may be made of PET (polyethylene terephthalate), PP (polypropylene), PVC (polyvinyl chloride), or the like.
  • the paper may be impregnated with epoxy resin or phenolic resin.
  • the substrate is preferably made of resin or paper, and more preferably made of PET (polyethylene terephthalate) or paper.
  • the substrate may be made of resin, glass, or paper.
  • the above wiring may be gold wiring, nickel wiring, tin wiring, aluminum wiring, silver wiring, SUS wiring, copper wiring, molybdenum wiring, tungsten wiring, etc. From the viewpoint of improving the operating sensitivity in the UHF band (860 MHz to 920 MHz), the above wiring is preferably aluminum wiring.
  • the thickness of the substrate is preferably 20 ⁇ m or more, more preferably 30 ⁇ m or more, and is preferably 200 ⁇ m or less, more preferably 100 ⁇ m or less.
  • the shapes of the substrate and the base material are not particularly limited. From the viewpoint of manufacturing RFID inlays by a roll-to-roll method, it is preferable that the substrate and the base material are long.
  • the length of the substrate and the base material is not particularly limited. The length of the substrate and the base material may be 1 m or more, 10 m or more, 5000 m or less, or 1000 m or less.
  • the surface tension of the substrate (base material) is preferably 30 mN/m or more, more preferably 32 mN/m or more, even more preferably 34 mN/m or more, and is preferably 50 mN/m or less, more preferably 48 mN/m or less, even more preferably 45 mN/m or less. If the surface tension of the substrate (base material) is equal to or more than the lower limit and equal to or less than the upper limit, the adhesiveness can be further improved.
  • the conductive paste of the present invention can be suitably used for application to a substrate (base material) having a surface tension equal to or more than the lower limit and equal to or less than the upper limit.
  • the surface tension of the above substrate (base material) can be measured in accordance with JIS K6768 using the following method. A cotton swab is dipped in the JIS-specified liquid and applied to the substrate (base material). The surface tension is determined from the shape of the coating two seconds after application.
  • the above chips include semiconductor chips (IC chips), etc.
  • the chip has an electrode on its surface.
  • the electrode include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, silver electrodes, SUS electrodes, copper electrodes, molybdenum electrodes, and tungsten electrodes. From the viewpoint of further improving the reliability of electrical conduction, the electrode is preferably a copper electrode or a gold electrode, and more preferably a copper electrode.
  • the number of electrodes per chip is not particularly limited.
  • the number of electrodes per chip may be 1 or more, 4 or more, 20 or less, or 10 or less.
  • the shape of the tip is not particularly limited.
  • the tip may be rectangular, triangular, or circular.
  • the plane area of the chip is preferably 0.04 mm2 or more, more preferably 0.09 mm2 or more, even more preferably 0.16 mm2 or more, and is preferably 0.50 mm2 or less, more preferably 0.40 mm2 or less, even more preferably 0.30 mm2 or less.
  • the conductive paste can be arranged on the fine wiring with high precision.
  • the conductive reliability can be maintained even when the RFID inlay is left in a high-temperature and high-humidity environment for a long period of time.
  • the conductive paste according to the present invention can be suitably used for bonding relatively small chips.
  • Curable Compounds Isobornyl acrylate ((A) polymerizable monomer, molecular weight: 208) Polyester urethane acrylate ("UN-353” manufactured by Negami Chemical Industries, Ltd., molecular weight (weight average molecular weight): 5000) Tricyclodecane dimethanol diacrylate (“IRR214” manufactured by Daicel Allnex Corporation, molecular weight: 304) Bisphenol A type epoxy resin (“EXA850CRP” manufactured by DIC Corporation, molecular weight (weight average molecular weight): 340)
  • Conductive filler Conductive particle A (conductive particle having a base particle and a conductive portion on the surface of the base particle (base particle: resin particle, conductive portion: nickel), average particle size: 5 ⁇ m, specific gravity: 2.0)
  • Conductive particles B conductive particles having a base particle and a conductive portion on the surface of the base particle (base particle: resin particle, conductive portion: nickel), average particle size: 5 ⁇ m, specific gravity: 1.5)
  • Conductive Particle C Conductive particle having a base particle and a conductive portion on the surface of the base particle (base particle: resin particle, conductive portion: nickel), average particle size: 5 ⁇ m, specific gravity: 4.0)
  • Conductive particle D Conductive particle having a base particle and a conductive portion on the surface of the base particle (base particle: resin particle, conductive portion: silver 75% by weight, nickel 25% by weight), average particle diameter: 5 ⁇ m, specific gravity: 2.3)
  • Conductive Particle E Conductive particle having a base particle and a conductive portion on the surface of
  • Inorganic filler Silica (Tokuyama Corporation "PM-20L")
  • Tips IC chip (gold electrode, NXP "UCODE8", surface area: 0.22 mm 2 )
  • PET film long, resin film with aluminum wiring and operating frequency in the UHF band (860 MHz to 920 MHz), surface tension: 43 mN/m
  • Example 1 (1) Preparation of Conductive Paste The materials shown in Table 1 below were mixed in the amounts shown in Table 1 below and stirred using a planetary mixer (Thinky Corporation's "Awatori Rentaro") to obtain a conductive paste (anisotropic conductive paste).
  • a planetary mixer Thinky Corporation's "Awatori Rentaro”
  • connection step the wiring on the surface of the PET film and the electrodes on the surface of the chip were electrically connected by the conductive filler in the adhesive to obtain a connection structure (adhesion step).
  • the first arrangement step, the second arrangement step, and the adhesion step were performed using "DDA40000" (roll-to-roll method, part of the conveying path has a part where the conveyed object is conveyed vertically) manufactured by Muhlbauer.
  • the resulting connection structure was cut to a size of 5 cm x 1.5 cm using a "DCL30000" manufactured by Muhlbauer to obtain an RFID inlay.
  • Examples 2 to 10 and Comparative Examples 1 to 9 Conductive pastes and RFID inlays were obtained in the same manner as in Example 1, except that the ingredients and amounts of the conductive paste were changed as shown in Tables 1, 3, 5, and 7.
  • Viscosity The obtained conductive paste was measured for viscosity ( ⁇ A) at 25°C and 5 rpm and viscosity ( ⁇ B) at 25°C and 0.5 rpm using an E-type viscometer (Toki Sangyo Co., Ltd.'s "TV22 type viscometer”). From the obtained results, the thixotropic index (ratio ( ⁇ B/ ⁇ A)) was obtained.
  • the conductive paste components other than the conductive filler in each example and comparative example were mixed in the amounts shown in Tables 1, 3, 5, and 7, and stirred using a planetary mixer (Thinky Corporation's "Awatori Rentaro") to obtain a composition containing the conductive paste materials other than the conductive filler.
  • the obtained composition was measured for viscosity ( ⁇ C) at 25°C and 5 rpm of the composition other than the conductive filler in the conductive paste using an E-type viscometer (Toki Sangyo Co., Ltd.'s "TV22 type viscometer”).
  • ⁇ The number of conductive fillers on all electrodes is 3 or more.
  • ⁇ The number of conductive fillers on at least one electrode is 2 or less.
  • ⁇ The peak sensitivity of all RFID inlays is less than -18 dBm.
  • ⁇ The peak sensitivity of at least one RFID inlay is -18 dBm or more.
  • REFERENCE SIGNS LIST 1 conductive filler 81
  • RFID inlay 82 ...substrate having wiring on its surface 82a
  • wiring 83 ...chip having electrode on its surface 83a

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PCT/JP2023/042741 2022-11-30 2023-11-29 導電ペースト、ｒｆｉｄインレイ及びｒｆｉｄインレイの製造方法 Ceased WO2024117181A1 (ja)

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CN202380059013.3A CN119678228A (zh) 2022-11-30 2023-11-29 导电糊、rfid嵌体和rfid嵌体的制造方法
JP2024519634A JP7808187B2 (ja) 2022-11-30 2023-11-29 導電ペースト、ｒｆｉｄインレイ及びｒｆｉｄインレイの製造方法
KR1020247039789A KR20250115908A (ko) 2022-11-30 2023-11-29 도전 페이스트, rfid 인레이 및 rfid 인레이의 제조 방법

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Publication number Priority date Publication date Assignee Title
WO2018181694A1 (ja) * 2017-03-30 2018-10-04 積水化学工業株式会社 導電性粒子、導電材料及び接続構造体
WO2018230470A1 (ja) * 2017-06-12 2018-12-20 積水化学工業株式会社 樹脂粒子、導電性粒子、導電材料、接着剤、接続構造体及び液晶表示素子
WO2020054288A1 (ja) * 2018-09-14 2020-03-19 積水化学工業株式会社 導電材料及び接続構造体
WO2020230842A1 (ja) * 2019-05-14 2020-11-19 積水化学工業株式会社 樹脂粒子、導電性粒子、導電材料及び接続構造体

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US20060111496A1 (en) 2004-11-24 2006-05-25 Stijn Gillissen Low temperature snap cure material with suitable worklife
JP6231257B2 (ja) 2011-12-15 2017-11-15 デクセリアルズ株式会社 導電性接着剤、及び電子部品の接続方法

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Publication number Priority date Publication date Assignee Title
WO2018181694A1 (ja) * 2017-03-30 2018-10-04 積水化学工業株式会社 導電性粒子、導電材料及び接続構造体
WO2018230470A1 (ja) * 2017-06-12 2018-12-20 積水化学工業株式会社 樹脂粒子、導電性粒子、導電材料、接着剤、接続構造体及び液晶表示素子
WO2020054288A1 (ja) * 2018-09-14 2020-03-19 積水化学工業株式会社 導電材料及び接続構造体
WO2020230842A1 (ja) * 2019-05-14 2020-11-19 積水化学工業株式会社 樹脂粒子、導電性粒子、導電材料及び接続構造体

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