Classifications

• • 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
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
  • C09J175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
• • 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
  • 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
• • 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

Definitions

• the present invention relates to a conductive paste containing conductive particles, an RFID inlay using the conductive paste, and a method for manufacturing an RFID inlay.
• the invention also relates to the use of conductive pastes for bonding chips and to the use of conductive pastes for obtaining RFID inlays.
• RFID (Radio Frequency Identification) inlays that can send and receive data in a contactless manner are widely used in contactless RFID tags, contactless RFID cards, and the like.
• RFID inlays in the UHF (Ultra High Frequency) band (860MHz to 960MHz) are attracting attention because of their long communication distance, and RFID inlays in the UHF band are used for commuter passes, inventory management, distribution management, history management, etc. It is used for various products and purposes.
• a conductive paste containing conductive particles and a binder resin is sometimes used for adhesion and connection between a chip having an electrode on its surface and a substrate having wiring (antenna pattern) on its surface.
• Patent Document 1 discloses an adhesive that can be applied to electronic components.
• the adhesive is an acrylic adhesive composition containing a radical initiator having a 10-hour half-life temperature of 80° C. or lower, a vinylene-containing oligomer, and at least one diluent.
• the adhesive can be snap cured at low temperatures and has a pot life of 24 hours or more at room temperature.
• Patent Document 1 describes urethane acrylate as an example of the vinylene-containing oligomer.
• Patent Document 2 below includes a polymerizable acrylic compound, an organic peroxide, and solder particles, and the organic peroxide has a 1-minute half-life temperature lower than the solidus temperature of the solder particles.
• a conductive adhesive is disclosed.
• Patent Document 2 describes urethane acrylate as an example of the polymerizable acrylic compound.
• the curable compound includes a curable compound, a plurality of conductive particles, and a thermal polymerization initiator, and the curable compound is a urethane having a molecular weight of 1000 or more and having an aromatic skeleton.
• the conductive paste contains (meth)acrylate and a polymerizable monomer having a molecular weight of less than 1000 and an aromatic skeleton or an alicyclic skeleton, and the viscosity of the conductive paste at 25°C is 5 Pa ⁇ s or more and 50 Pa ⁇ s.
• a conductive paste is provided that has a conductive paste of less than or equal to s.
• the content of the conductive particles is 3 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the curable compound in the conductive paste.
• the conductive particles have a particle size of 10 ⁇ m or less.
• the conductive particles include base particles and conductive parts disposed on the surfaces of the base particles, and the conductive parts contain nickel.
• a cured product obtained by heating the conductive paste at 150° C. for 10 minutes has a storage modulus at 25° C. of 0.7 GPa or more and 3.0 GPa or less.
• the conductive paste is applied and used on a substrate having a surface tension of 20 mN/m or more and 50 mN/m or less.
• the conductive paste is used to bond chips having a planar area of 0.50 mm 2 or less.
• the conductive paste is used to obtain an RFID inlay.
• the invention includes a substrate having wiring on its surface, a chip, and an adhesive portion bonding the substrate and the chip, and the material of the adhesive portion is the above-mentioned conductive paste.
• an RFID inlay is provided, wherein the wiring and the chip are electrically connected by the conductive particles in the adhesive.
• the substrate is elongated, and the first arrangement step, the second arrangement step, and the bonding step are performed by a roll-to-roll method. , the long substrate is transported to manufacture an RFID inlay.
• a conductive paste as described above for bonding chips having a planar area of 0.50 mm 2 or less.
• the conductive paste according to the present invention includes a curable compound, a plurality of conductive particles, and a thermal polymerization initiator.
• the curable compound has a molecular weight of 1000 or more and an aromatic skeleton, and a urethane (meth)acrylate having a molecular weight of less than 1000 and an aromatic skeleton or an alicyclic skeleton.
• the viscosity at 25° C. of the conductive paste according to the present invention is 5 Pa ⁇ s or more and 50 Pa ⁇ s or less. Since the conductive paste according to the present invention has the above-mentioned configuration, it is possible to improve adhesiveness and conductivity reliability.
• the conductive paste according to the present invention includes (A) a curable compound, a plurality of (B) conductive particles, and (C) a thermal polymerization initiator.
• the curable compound includes (A1) a urethane (meth)acrylate having a molecular weight of 1000 or more and an aromatic skeleton, and (A2) a molecular weight of less than 1000, and A polymerizable monomer having an aromatic skeleton or an alicyclic skeleton.
• the viscosity at 25° C. of the conductive paste according to the present invention is 5 Pa ⁇ s or more and 50 Pa ⁇ s or less.
• the conductive paste according to the present invention has the above configuration, it is possible to improve adhesiveness. Further, since the conductive paste according to the present invention has the above-described configuration, the conductive paste can be placed on fine wiring with high precision, and as a result, the conduction reliability can be improved. Furthermore, since the conductive paste according to the present invention has the above-mentioned configuration, it maintains high continuity reliability even when the connected structure (electronic component) is left in a high temperature and high humidity environment for a long time. be able to.
• the present inventors have discovered that by combining a specific urethane (meth)acrylate and a specific polymerizable monomer, it is possible to enhance the adhesiveness of the conductive paste and increase the continuity reliability.
• the conductive paste according to the present invention is paste-like at 25°C.
• the above-mentioned conductive paste is used by being discharged at, for example, 20° C. to 30° C.
• the viscosity ( ⁇ 25) at 25°C of the conductive paste is preferably 6 Pa ⁇ s or more, more preferably 10 Pa ⁇ s or more, even more preferably 15 Pa ⁇ s or more, and preferably 48 Pa ⁇ s or less, more preferably 45 Pa ⁇ s. ⁇ s or less, more preferably 40 Pa ⁇ s or less.
• the viscosity ( ⁇ 25) is equal to or higher than the lower limit, it is possible to prevent the conductive paste from flowing out from the wiring.
• the viscosity ( ⁇ 25) is below the upper limit, the conductive paste can be placed on fine wiring with higher precision.
• the above viscosity ( ⁇ 25) can be measured, for example, using an E-type viscometer at 25° C. and 5 rpm.
• E-type viscometer examples include "TV22 type viscometer” manufactured by Toki Sangyo Co., Ltd.
• the above-mentioned conductive paste has good adhesive properties.
• the above conductive paste is suitably used as an adhesive.
• the above-mentioned conductive paste is particularly suitable for adhesion between a substrate and a chip.
• the conductive paste is preferably an anisotropic conductive paste.
• the above-mentioned conductive paste is suitably used for electrical connection of electrodes.
• the above-mentioned conductive paste is suitably used to obtain a connected structure.
• the above conductive paste is suitably used to obtain electronic components.
• the conductive paste described above is particularly preferably used for obtaining an RFID inlay (Use of the conductive paste described above for obtaining an RFID inlay).
• the above conductive paste is suitably used for adhesion and connection between a chip having an electrode on its surface and a substrate having wiring (antenna pattern) on its surface. (Use of the above conductive paste for adhesion and connection with a substrate having a substrate).
• the above conductive paste is preferably applied to a substrate having a surface tension of 20 mN/m or more and 50 mN/m or less (use of the above conductive paste on a substrate having a surface tension of 20 mN/m or more and 50 mN/m or less). ). It is particularly preferable that the conductive paste is 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 is preferably used for bonding chips with a planar area of 0.50 mm 2 or less (use of the conductive paste for bonding chips with a planar area of 0.50 mm 2 or less).
• the conductive paste has thermosetting properties.
• the conductive paste is preferably a thermosetting conductive paste, more preferably a thermosetting anisotropic conductive paste.
• the storage modulus at 25°C of the cured product obtained by heating the conductive paste at 150°C for 10 minutes is preferably 0.7 GPa or more, more preferably 0.8 GPa or more, still more preferably 1.0 GPa or more, especially It is preferably 1.5 GPa or more, preferably 3.0 GPa or less, more preferably 2.8 GPa or less, and still more preferably 2.5 GPa or less.
• the storage elastic modulus at 25°C of the cured product is not less than the above lower limit and not more than the above upper limit, the adhesion can be further improved, and cracks and warpage may occur at the bonded part of the resulting connected structure. can be effectively prevented.
• the storage modulus of the cured product at 25° C. can be measured using a dynamic viscoelasticity measuring device (for example, “DVA-200” manufactured by IT Keizai Control Co., Ltd.).
• the measurement using the dynamic viscoelasticity measuring device is performed using, for example, a measurement sample cut out from the cured product into a size of 50 mm in length, 3 mm in width, and 1 mm in thickness, at a frequency of 10 Hz, a strain of 0.1%, a tensile width, and a grip. This can be done with a width of 20 mm.
• the curing conditions for the conductive paste are 150° C. and 10 minutes.
• the heating conditions may not be the same.
• (meth)acrylate refers to acrylate and methacrylate.
• (Meth)acrylic refers to acrylic and methacrylic.
• (Meth)acryloyl refers to acryloyl and methacryloyl.
• the conductive paste includes (A) a curable compound.
• the curable compound (A) contains the following components.
• (A1) Urethane (meth)acrylate having a molecular weight of 1000 or more and having an aromatic skeleton hereinafter sometimes referred to as "(A1) urethane (meth)acrylate”
• (A2) A polymerizable monomer having a molecular weight of less than 1000 and having an aromatic skeleton or an alicyclic skeleton (hereinafter sometimes referred to as "(A2) polymerizable monomer”).
• the content of the curable compound (A) in 100% by weight of the conductive paste 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.
• the content is more preferably 45% by weight or less, particularly preferably 40% by weight or less, and most preferably 35% by weight or less.
• the total content of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) in 100% by weight of the conductive paste is preferably 20% by weight or more, more preferably 25% by weight or more. be.
• the total content of the (A1) urethane (meth)acrylate and the (A2) polymerizable monomer is preferably 75% by weight or less, more preferably 70% by weight or less, It is more preferably 65% by weight or less, particularly preferably 60% by weight or less, and most preferably 55% by weight or less.
• the viscosity of the conductive paste can be adjusted to a suitable range. It is possible to further improve adhesiveness and conduction reliability.
• the total content of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) is preferably 20% by weight or more, more preferably 40% by weight. It is at least 90% by weight, preferably at most 90% by weight, and more preferably at most 80% by weight.
• the viscosity of the conductive paste can be adjusted to a suitable range. It is possible to further improve adhesiveness and conduction reliability.
• the urethane (meth)acrylate (A1) has a molecular weight of 1000 or more and has an aromatic skeleton.
• the above (A1) urethane (meth)acrylate is an aromatic urethane (meth)acrylate having a molecular weight of 1000 or more.
• the above (A1) urethane (meth)acrylate has an aromatic skeleton, a urethane bond, and a (meth)acroyl group.
• the above (A1) urethane (meth)acrylate may be a urethane (meth)acrylate having one (meth)acryloyl group, or may be a urethane (meth)acrylate having two or more (meth)acryloyl groups. good.
• the above (A1) urethane (meth)acrylate may be a monofunctional (meth)acrylate, a bifunctional (meth)acrylate, a trifunctional (meth)acrylate, or a tetrafunctional (meth)acrylate. It may also be a (meth)acrylate with higher functionality.
• the above (A1) urethane (meth)acrylate may have 100 or less, 50 or less, or 10 or less (meth)acryloyl groups.
• urethane (meth)acrylates include "CN973”, “CN978NS”, “CN992”, “CN9167”, “CN9782”, “CN9783”, “CN970”, “CN971”, “CN972”, “CN975NS”.
• the above (A1) urethane (meth)acrylate can be obtained, for example, by the following method.
• a method of reacting a polyol compound, an isocyanate compound, and a (meth)acrylic acid derivative having an aromatic skeleton in the presence of a catalyst A method of reacting a polyol compound having an aromatic skeleton, an isocyanate compound, and a (meth)acrylic acid derivative in the presence of a catalyst.
• a method of reacting an isocyanate compound having an aromatic skeleton with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalyst A method of reacting a polyocyanate compound having an aromatic skeleton with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalyst.
• the molecular weight of the urethane (meth)acrylate (A1) is preferably 1,500 or more, more preferably 2,000 or more, even more preferably 3,000 or more, particularly preferably 5,000 or more, preferably 30,000 or less, more preferably 25,000 or less, and It is preferably 20,000 or less, particularly preferably 18,000 or less.
• adhesiveness can be further improved and conduction reliability can be further improved.
• the molecular weight of the above (A1) urethane (meth)acrylate means, when the structural formula of the above (A1) urethane (meth)acrylate can be specified, the molecular weight that can be calculated from the structural formula.
• the above molecular weight means a weight average molecular weight.
• the above weight average molecular weight indicates the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).
• the molecular weight of the urethane (meth)acrylate (A1) is preferably a weight average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene.
• the weight average molecular weight can be measured using the following measuring device and measuring conditions.
• Measuring device “Waters GPC System (Waters 2690+Waters 2414 (RI))” manufactured by Nippon Waters Co., Ltd. Measurement conditions 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 differential detector (RID) Standard substance: Polystyrene (manufactured by TOSOH, weight average molecular weight: 620-590000)
• the viscosity of the urethane (meth)acrylate (A1) at 25°C is preferably 10 Pa ⁇ s or more, more preferably 50 Pa ⁇ s or more, even more preferably 100 Pa ⁇ s or more, and preferably 3000 Pa ⁇ s or less, more It is preferably 2,500 Pa ⁇ s or less, more preferably 2,000 Pa ⁇ s or less.
• the viscosity of the urethane (meth)acrylate (A1) at 25° C. is not less than the above lower limit and not more than the above upper limit, adhesiveness can be further improved and conduction reliability can be further improved.
• the viscosity of the urethane (meth)acrylate (A1) at 25°C can be measured, for example, using an E-type viscometer at 25°C and 5 rpm.
• E-type viscometer examples include "TV22 type viscometer” manufactured by Toki Sangyo Co., Ltd.
• the content of the urethane (meth)acrylate (A1) in 100% by weight of the conductive paste 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 more. % by weight or less.
• the total content of the urethane (meth)acrylate (A1) is not less than the above lower limit and not more than the above upper limit, adhesiveness can be further improved and conduction reliability can be further improved.
• the content of the urethane (meth)acrylate (A1) is preferably 15% by weight or more, more preferably 20% by weight or more, and preferably 50% by weight or less, More preferably, it is 45% by weight or less.
• the total content of the urethane (meth)acrylate (A1) is not less than the above lower limit and not more than the above upper limit, adhesiveness can be further improved and conduction reliability can be further improved.
• the content of the above (A1) urethane (meth)acrylate is preferably 15% by weight or more, more preferably in the total 100% by weight of the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer. is 20% by weight or more, preferably 70% by weight or less, more preferably 65% by weight or less.
• the viscosity of the conductive paste can be adjusted to a suitable range, and the adhesiveness can be further improved and the conductivity can be improved. Reliability can be further improved.
• the polymerizable monomer (A2) has a molecular weight of less than 1000 and has an aromatic skeleton or an alicyclic skeleton.
• the polymerizable monomer (A2) above may have an aromatic skeleton, an alicyclic skeleton, or both an aromatic skeleton and an alicyclic skeleton. Good too.
• the polymerizable monomer (A2) may include a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton.
• the above (A2) polymerizable monomer is preferably a polymerizable monomer other than urethane (meth)acrylate having an aromatic skeleton, and preferably a polymerizable monomer other than urethane (meth)acrylate. More preferred.
• the polymerizable monomer (A2) is a polymerizable component that can be homopolymerized or copolymerized.
• Examples of the polymerizable monomers having an aromatic skeleton include 2-phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, ethoxylated (4) nonylphenol (meth)acrylate, and alkoxy phenol (meth)acrylate, ethoxylated (3) bisphenol A (meth) diacrylate, ethoxylated (4) bisphenol A (meth) diacrylate, ethoxylated (10) bisphenol A (meth) diacrylate, and ethoxylated ( 30) Bisphenol A (meth) diacrylate and the like.
• the polymerizable monomer (A2) having an aromatic skeleton is 2-phenoxyethyl (meth)acrylate or ethoxylated ( 3) Bisphenol A (meth) diacrylate is preferred.
• Examples of the polymerizable monomer having an alicyclic skeleton include cyclohexyl (meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, isobornyl (meth)acrylate, 4- tert-butylcyclohexanol, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, pentamethylpiperidyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, acrylic Examples include lomorpholine and 3,3,5-trimethylcyclohexyl (meth)acrylate.
• the polymerizable monomer (A2) having an alicyclic skeleton is cyclohexyl (meth)acrylate or isobornyl (meth)acrylate. It is preferable that
• the molecular weight of the polymerizable monomer (A2) is preferably 50 or more, more preferably 100 or more, even more preferably 150 or more, particularly preferably 200 or more, and preferably 950 or less, more preferably 900 or less, and It is preferably 800 or less, particularly preferably 700 or less.
• the molecular weight of the polymerizable monomer (A2) is not less than the lower limit and not more than the upper limit, the compatibility with the urethane (meth)acrylate (A1) is improved, and the viscosity of the conductive paste is adjusted to a suitable range. It is possible to further improve adhesiveness and conduction reliability.
• the molecular weight of the polymerizable monomer (A2) above means, when the structural formula of the polymerizable monomer (A2) above can be specified, the molecular weight that can be calculated from the structural formula. Furthermore, when the polymerizable monomer (A2) is a polymer whose structural formula cannot be specified, the above molecular weight means a weight average molecular weight.
• the above weight average molecular weight indicates the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC). Since the polymerizable monomer (A2) has a relatively small molecular weight, its structural formula can generally be specified.
• the weight average molecular weight can be measured using the following measuring device and measuring conditions.
• Measuring device “Waters GPC System (Waters 2690+Waters 2414 (RI))” manufactured by Nippon Waters Co., Ltd. Measurement conditions 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 differential detector (RID) Standard substance: Polystyrene (manufactured by TOSOH, weight average molecular weight: 620-590000)
• the viscosity at 25°C of the polymerizable monomer (A2) is preferably 5 Pa ⁇ s or more, more preferably 10 Pa ⁇ s or more, even more preferably 15 Pa ⁇ s or more, and preferably 50 Pa ⁇ s or less, more preferably It is preferably 45 Pa ⁇ s or less, more preferably 40 Pa ⁇ s or less.
• the viscosity at 25°C of the polymerizable monomer (A2) is at least the above lower limit and below the above upper limit, the conductive paste can be placed on fine wiring with higher precision and has good wettability to the substrate. It can be done.
• the viscosity of the polymerizable monomer (A2) at 25°C can be measured, for example, using an E-type viscometer at 25°C and 5 rpm.
• E-type viscometer examples include "TV22 type viscometer” manufactured by Toki Sangyo Co., Ltd.
• the content of the polymerizable monomer (A2) in 100% by weight of the conductive paste 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 more. % by weight or less.
• the content of the polymerizable monomer (A2) is not less than the lower limit and not more than the upper limit, the compatibility with the urethane (meth)acrylate (A1) is improved, and the viscosity of the conductive paste is within a suitable range. It is possible to further improve adhesiveness and conduction reliability.
• the above (A2) polymerizable monomer contains a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton
• the above (A2) polymerizable monomer contains a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton
• the above (A2) polymerizable monomer The content of polymers indicates the total content of polymerizable monomers having an aromatic skeleton and polymerizable monomers having an alicyclic skeleton.
• the content of the polymerizable monomer (A2) in 100% by weight of the curable compound (A) is preferably 10% by weight or more, more preferably 15% by weight or more, and preferably 55% by weight or less, More preferably, it is 50% by weight or less.
• the content of the polymerizable monomer (A2) is not less than the lower limit and not more than the upper limit, the compatibility with the urethane (meth)acrylate (A1) is improved, and the viscosity of the conductive paste is within a suitable range. It is possible to further improve adhesiveness and conduction reliability.
• the above (A2) polymerizable monomer contains a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton
• the above (A2) polymerizable monomer contains a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton
• the above (A2) polymerizable monomer The content of polymers indicates the total content of polymerizable monomers having an aromatic skeleton and polymerizable monomers having an alicyclic skeleton.
• the content of the polymerizable monomer (A2) is preferably 15% by weight or more, more preferably, in the total 100% by weight of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2). is 20% by weight or more, preferably 55% by weight or less, more preferably 50% by weight or less.
• the content of the polymerizable monomer (A2) is not less than the lower limit and not more than the upper limit, the compatibility with the urethane (meth)acrylate (A1) is improved, and the viscosity of the conductive paste is within a suitable range. It is possible to further improve adhesiveness and conduction reliability.
• the above (A2) polymerizable monomer contains a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton
• the above (A2) polymerizable monomer contains a polymerizable monomer having an aromatic skeleton and a polymerizable monomer having an alicyclic skeleton
• the above (A2) polymerizable monomer The content of polymers indicates the total content of polymerizable monomers having an aromatic skeleton and polymerizable monomers having an alicyclic skeleton.
• the above (A) curable compound may contain a curable compound other than both the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer.
• the curable compound (A) may contain a urethane (meth)acrylate other than both the urethane (meth)acrylate (A1) and the polymerizable monomer (A2).
• the curable compound (A) may contain a polymerizable component (polymerizable monomer) other than both the urethane (meth)acrylate (A1) and the polymerizable monomer (A2).
• the curable compounds (polymerizable components) other than the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer are not particularly limited.
• the curable compound (polymerizable component) other than the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate. There may be.
• the curable compound (polymerizable component) other than the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer may be a difunctional (meth)acrylate, or a trifunctional (meth)acrylate.
• the curable compound (polymerizable component) other than the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer may have 100 or less (meth)acryloyl groups, and 50 or less It may have 10 or less.
• the above monofunctional (meth)acrylates include 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and lauryl (meth)acrylate.
• polyfunctional (meth)acrylates examples include 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate.
• 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, polyethylene glycol ( 600) di(meth)acrylate, polypropylene glycol (700)(meth)acrylate, propoxylated (2) neopentyl glycol di(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate Acrylate, tri
• the above (A) curable compound is a cured compound other than the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer. It is preferable that the composition contains a polymerizable compound (polymerizable component). From the viewpoint of increasing the storage modulus of the cured product and further enhancing the adhesiveness, curable compounds (polymerizable components) other than the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer are: It is preferable that a polyfunctional curable compound is included, and it is more preferable that a polyfunctional (meth)acrylate is included.
• the conductive paste includes a plurality of (B) conductive particles.
• the conductive particles (B) are not particularly limited.
• the conductive particles (B) may be solder particles or metal particles.
• the conductive particles (B) may include a base particle and a conductive part disposed on the surface of the base particle. From the viewpoint of further enhancing conduction reliability, the conductive particles (B) preferably include base particles and conductive parts disposed on the surfaces of the base particles.
• the particle diameter of the conductive particles (B) is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, even more preferably 3 ⁇ m or more, and preferably 100 ⁇ m or less, more preferably 30 ⁇ m or less, and even more preferably 10 ⁇ m or less. be.
• the particle diameter of the conductive particles (B) is not less than the above lower limit and not more than the above upper limit, the conduction reliability can be further improved.
• the particle diameter of the conductive particles (B) is preferably an average particle diameter, and more preferably a number average particle diameter.
• the average particle diameter of the above-mentioned conductive particles can be determined, for example, by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating the average value of the particle diameter of each conductive particle, or by using a laser diffraction method. It is obtained by performing distribution measurements.
• conductive particles when measuring the particle diameter of the conductive particles by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope, for example, as follows. Can be measured. A conductive particle content of 30% by weight is added to "Technovit 4000" manufactured by Kulzer and dispersed to prepare an embedded resin body for conductive particle inspection. Using an ion milling device ("IM4000" manufactured by Hitachi High Technologies), a cross section of the conductive particles is cut out so as to pass through the center of the conductive particles dispersed in the embedded resin body for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 25,000 times, 50 conductive particles are randomly selected, and each conductive particle is observed. The equivalent circle diameter of each conductive particle is measured, and the arithmetic average of these is determined as the particle diameter of the conductive particle.
• FE-SEM field emission scanning electron microscope
• the coefficient of variation (CV value) of the particle diameter of the conductive particles (B) is preferably 10% or less, more preferably 5% or less. When the coefficient of variation of the particle diameter of the conductive particles (B) is equal to or less than the above upper limit, the conduction reliability can be further improved.
• the lower limit of the coefficient of variation (CV value) of the particle diameter of the conductive particles (B) is not particularly limited.
• the coefficient of variation (CV value) of the particle diameter of the conductive particles (B) 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) x 100 ⁇ : Standard deviation of particle diameter of conductive particles Dn: Average value of particle diameter of conductive particles
• the shape of the conductive particles (B) is not particularly limited.
• the conductive particles (B) may have a spherical shape, a shape other than a spherical shape, a flat shape, or the like.
• the content of the conductive particles (B) in 100% by weight of the conductive paste is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and preferably 80% by weight or less, more preferably is 60% by weight or less, more preferably 40% by weight or less, particularly preferably 20% by weight or less, most preferably 10% by weight or less.
• the content of the conductive particles (B) is not less than the above lower limit and not more than the above upper limit, the conduction reliability can be further improved.
• the content of the conductive particles (B) is preferably 2 parts by weight or more, more preferably 3 parts by weight or more, and even more preferably 5 parts by weight.
• the amount is at least 7 parts by weight, particularly preferably at least 7 parts by weight.
• the content of the conductive particles (B) is preferably 35 parts by weight or less, more preferably 30 parts by weight or less, and even more preferably 25 parts by weight. It is not more than 20 parts by weight, particularly preferably not more than 20 parts by weight.
• the content of the conductive particles (B) is preferably 3 parts by weight with respect to a total of 100 parts by weight of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) in the conductive paste. parts by weight or more, more preferably 5 parts by weight or more, still more preferably 7 parts by weight or more.
• the content of the conductive particles (B) is preferably 30 parts by weight with respect to a total of 100 parts by weight of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) in the conductive paste. parts by weight or less, more preferably 25 parts by weight or less, still more preferably 20 parts by weight or less.
• the conductive particles (B) are metal particles
• examples of the metal that is the material of the metal particles include alloys such as silver, copper, nickel, silicon, gold, titanium, and solder.
• the material of the metal particles preferably contains nickel or a nickel alloy, and the material of the metal particles is more preferably nickel or a nickel alloy. From the viewpoint of further effectively increasing conduction reliability, it is preferable that the outer surface portion of the metal particle contains nickel or a nickel alloy.
• the conductive particles including a base particle and a conductive part arranged on the surface of the base particle will be described.
• 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 excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles.
• the base particle may be a core-shell particle including 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 base particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles. By using these preferred base particles, the effects of the present invention can be exhibited even more effectively.
• resin particles are suitably used as materials for the resin particles.
• Materials 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, and polyamide.
• the divinylbenzene polymer may be a divinylbenzene copolymer.
• examples of the divinylbenzene copolymer include divinylbenzene-styrene copolymer and divinylbenzene-(meth)acrylic acid ester copolymer.
• resin particles having arbitrary compression characteristics suitable for conductive paste, and the hardness of the resin particles can be easily controlled within a suitable range. It is preferable that it is a polymer obtained by polymerizing one or more types of polymerizable monomers having a plurality of.
• the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer.
• examples include crosslinkable monomers.
• non-crosslinkable monomer examples include styrene monomers such as styrene and ⁇ -methylstyrene; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; methyl (meth) Acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate Alkyl (meth)acrylate compounds such as acrylate and isobornyl (meth)acrylate; Meth)acrylate compounds; Nitrile-containing monomers such as (meth)acrylonitrile; Acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; Unsaturated
• crosslinkable monomers examples include tetramethylolmethanetetra(meth)acrylate, tetramethylolmethanetri(meth)acrylate, tetramethylolmethanedi(meth)acrylate, trimethylolpropanetri(meth)acrylate, and dipentaerythritol hexaacrylate.
• (meth)acrylate dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, Polyfunctional (meth)acrylate compounds such as (poly)tetramethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate; triallyl(iso)cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate , diallylacrylamide, diallyl ether, ⁇ -(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, and other silane-containing monomers.
• the above resin particles can be obtained by polymerizing the above polymerizable monomer having an ethylenically unsaturated group by a known method.
• this method include a method in which suspension polymerization is carried out in the presence of a radical polymerization initiator, and a method in which monomers are swollen and polymerized together with a radical polymerization initiator using non-crosslinked seed particles.
• the base particles are inorganic particles excluding 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.
• the inorganic substance is not a metal.
• the particles formed from the above-mentioned silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, baking may be performed as necessary. Examples include particles obtained by Examples of 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 an organic core.
• the shell is an inorganic shell.
• the base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell arranged on the surface of the organic core. .
• Examples of the material for the organic core include the materials for the resin particles described above.
• the material for the inorganic shell examples include the inorganic substances listed as the material for the base particles described above.
• the material of the inorganic shell is preferably silica.
• the inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core, and then firing the shell-like material.
• the metal alkoxide is a silane alkoxide.
• the inorganic shell is preferably formed of silane alkoxide.
• the base particles are metal particles
• examples of the metal that is the material of the metal particles include alloys such as silver, copper, nickel, silicon, gold, titanium, and solder.
• the particle diameter of the base particles is preferably 0.05 ⁇ m or more, more preferably 0.01 ⁇ m or more, even more preferably 0.5 ⁇ m or more, even more preferably 1 ⁇ m or more, particularly preferably 3 ⁇ m or more, and preferably 50 ⁇ m.
• the thickness is more preferably 30 ⁇ m or less, further preferably 20 ⁇ m or less, particularly preferably 10 ⁇ m or less.
• the particle size of the base particles is preferably an average particle size, more preferably a number average particle size.
• the number average particle diameter of the base particles can be measured, for example, as follows. A conductive particle content of 30% by weight is added to "Technovit 4000" manufactured by Kulzer and dispersed to prepare an embedded resin body for conductive particle inspection. Using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies), a cross section of the conductive particles is cut out so as to pass through the center of the base particle in the conductive particles dispersed in the embedded resin body for inspection.
• IM4000 manufactured by Hitachi High-Technologies
• the image magnification was set to 25,000 times, 50 conductive particles were randomly selected, and the base material particles of each conductive particle were observed. do.
• the particle diameter of the base material particles in each conductive particle is measured, and the arithmetic mean of these is determined as the average particle diameter of the base material particles.
• the conductive part includes metal.
• the metal constituting the conductive part is not particularly limited. Examples of the above metals include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, ruthenium, nickel, chromium, titanium, antimony, bismuth, germanium, cadmium, and alloys thereof. It will be done. Furthermore, tin-doped indium oxide (ITO) may be used as the metal.
• ITO tin-doped indium oxide
• the above metals may be used alone or in combination of two or more. From the viewpoint of further lowering the connection resistance between electrodes, alloys containing tin, nickel, palladium, ruthenium, silver, copper, or gold are preferable, and nickel or palladium is more preferable.
• the conductive part contains nickel, and it is more preferable that the outer surface portion of the conductive part contains nickel.
• the content of nickel in 100% by weight of the conductive part containing nickel is preferably 10% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, still more preferably 70% by weight or more, particularly preferably is 90% by weight or more.
• the content of nickel in 100% by weight of the conductive portion containing nickel may be 99% by weight or less, 90% by weight or less, or 70% by weight or less.
• the above-mentioned conductive part may be formed of one layer.
• the conductive part may be formed of a plurality of 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 preferably nickel. is more preferable.
• the metal constituting the outermost layer is one of these preferred metals, the connection resistance between the electrodes becomes even lower.
• 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 part include electroless plating, electroplating, physical collision, mechanochemical reaction, physical vapor deposition or physical adsorption, and metal powder or Examples include a method of coating the surface of base particles with a paste containing 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. Further, in the method using physical collision, for example, a sheeter composer (manufactured by Tokuju Kosho Co., Ltd.) or the like is used.
• the thickness of the conductive part is preferably 0.005 ⁇ m or more, more preferably 0.01 ⁇ m or more, and 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 part is not less than the lower limit and not more than the upper limit, sufficient conductivity can be obtained, and the conductive particles can be sufficiently deformed during connection without becoming too hard. Can be done.
• the thickness of the outermost conductive part is preferably 0.001 ⁇ m or more, more preferably 0.01 ⁇ m or more, and preferably 0.5 ⁇ m or less, more preferably is 0.1 ⁇ m or less.
• the thickness of the conductive part of the outermost layer is greater than or equal to the lower limit and less than the upper limit, the conductive part of the outermost layer will be uniform, the corrosion resistance will be sufficiently high, and the connection resistance between the electrodes will be sufficiently low. can do.
• the thickness of the conductive part can be measured, for example, by observing the cross section of the conductive particles using a transmission electron microscope (TEM).
• TEM transmission electron microscope
• the conductive particles (B) have a plurality of protrusions on the outer surface of the conductive part.
• An oxide film is often formed on the surface of the electrode connected by the conductive particles.
• the oxide film can be effectively removed by the protrusions by placing and crimping the (B) conductive particles between the electrodes. .
• the electrode and the conductive part come into contact with each other more reliably, and the connection resistance between the electrodes becomes even lower.
• the projections of the (B) conductive particles can effectively eliminate the filler between the (B) conductive particles and the electrodes. Therefore, the reliability of conduction between the electrodes is further increased.
• the above protrusions can be formed by attaching a core substance to the surface of the base particle and then forming a conductive part by electroless plating, or by forming a conductive part by electroless plating on the surface of the base particle. After that, a method of attaching a core material and further forming a conductive part by electroless plating is mentioned.
• a conductive part is formed on the base material particle by electroless plating without using the above-mentioned core material, and then plating is deposited in the shape of a protrusion on the surface of the conductive part, and then electroless plating is performed.
• a method of forming a conductive portion using the above method may be used.
• the core substance is added to a dispersion of the base material particles, and the core substance is accumulated on the surface of the base material particles by van der Waals force.
• Examples include a method of attaching a core material, and a method of adding a core substance to a container containing base particles, and causing the core substance to adhere to the surface of the base particles by mechanical action such as rotation of the container.
• the method for attaching the core substance to the surface of the base material particles is a method in which the core substance is accumulated and attached to the surface of the base material particles in the dispersion liquid. preferable.
• Examples of the substance constituting the core substance include conductive substances and non-conductive substances.
• Examples of the conductive substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers.
• Examples of the conductive polymer include polyacetylene.
• Examples of the non-conductive substance include silica, alumina, titanium oxide, tungsten carbide, and zirconia. From the viewpoint of further increasing the reliability of conduction between the electrodes, it is preferable that the core material is metal.
• the above metals are not particularly limited.
• the above metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, and tin-lead.
• examples include alloys composed of two or more metals, such as alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide.
• the metal is preferably nickel, copper, silver, or gold.
• the metal may be the same as or different from the metal constituting the conductive part.
• the shape of the core material is not particularly limited.
• the shape of the core material is preferably a block.
• Examples of the core substance include particulate lumps, aggregates of a plurality of microparticles, and irregularly shaped lumps.
• the particle size (average particle size) of the core substance 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 size of the core substance is at least the above lower limit and below the upper limit, the connection resistance between the electrodes can be effectively lowered.
• the particle size of the core substance is preferably an average particle size, more preferably a number average particle size.
• the particle size of the core substance can be determined, for example, by observing 50 arbitrary core substances with an electron microscope or optical microscope and calculating the average value of the particle size of each core substance, or by performing laser diffraction particle size distribution measurement. It is determined by
• the conductive paste contains (C) a thermal polymerization initiator.
• the thermal polymerization initiator (C) is a compound that can initiate polymerization by heating.
• the conductive paste contains the thermal polymerization initiator (C)
• the polymerizable components in the conductive paste can be polymerized by heating. Since the conductive paste contains the thermal polymerization initiator (C), upon heating, polymerization of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) starts.
• the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) may be copolymerized by heating, or each may be homopolymerized.
• a homopolymer of the above (A1) urethane (meth)acrylate may be formed by heating, a homopolymer of the above (A2) polymerizable monomer may be formed, and a homopolymer of the above (A2) polymerizable monomer may be formed by heating.
• a copolymer of A1) urethane (meth)acrylate and the above (A2) polymerizable monomer may be formed. From the viewpoint of further increasing adhesiveness and conduction reliability, a copolymer of the above (A1) urethane (meth)acrylate and the above (A2) polymerizable monomer is formed by heating. It is preferable that
• the thermal polymerization initiator (C) preferably contains a thermal radical polymerization initiator, and is preferably a thermal radical polymerization initiator.
• examples of the thermal radical polymerization initiator include peroxide radical polymerization initiators, azo radical polymerization initiators, redox radical polymerization initiators, and the like.
• the thermal polymerization initiator (C) may be used alone or in combination of two or more.
• azo radical polymerization initiator examples include azobisisobutyronitrile, azobiscyclohexanecarbonitrile, and azobisdimethylvaleronitrile.
• the peroxide radical polymerization initiators include diacyl radical polymerization initiators, peroxyester radical polymerization initiators, dialkyl radical polymerization initiators, percarbonate radical polymerization initiators, and ketone peroxide radical polymerization initiators. agents, etc.
• Examples of the diacyl radical polymerization initiator include lauroyl peroxide and benzoyl peroxide.
• Examples of the peroxyester-based radical polymerization initiator include t-butylperoxybenzoate, t-butylperoxyacetate, t-butylperoxypivalate, and t-butylperoxy-2-ethylhexanoate. .
• dialkyl radical polymerization initiator examples include dicumyl peroxide and di-t-butyl peroxide.
• percarbonate radical polymerization initiator examples include diisopropyl peroxydicarbonate.
• ketone peroxide radical polymerization initiator examples include methyl ethyl ketone peroxide.
• the redox-based 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 mixtures of benzoyl peroxide and organic amines, mixtures of the peroxyester radical polymerization initiator and reducing agents such as mercaptans, and methyl ethyl ketone peroxide and organic amines. Examples include mixtures with cobalt salts.
• the thermal polymerization initiator (C) preferably contains a peroxide-based radical polymerization initiator.
• the content of the thermal polymerization initiator (C) in 100% by weight of the conductive paste is preferably 0.1% by weight or more, more preferably 0.3% by weight. Above, the content is more preferably 0.5% by weight or more, preferably 5% by weight or less, more preferably 4% by weight or less, and still more preferably 3% by weight or less.
• the content of the thermal polymerization initiator (C) is preferably 0.3 parts by weight or more, more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the curable compound (A) in the conductive paste. , more preferably 0.7 parts by weight or more, preferably 6 parts by weight or less, more preferably 5 parts by weight or less, still more preferably 4 parts by weight or less.
• the content of the thermal polymerization initiator (C) is not less than the above lower limit and not more than the above upper limit, reactivity and storage stability can be improved.
• the content of the thermal polymerization initiator (C) is preferably 0 with respect to a total of 100 parts by weight of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) in the conductive paste.
• the amount is at least .4 parts by weight, more preferably at least 0.6 parts by weight, even more preferably at least 0.8 parts by weight.
• the content of the thermal polymerization initiator (C) is preferably 8 parts by weight with respect to a total of 100 parts by weight of the urethane (meth)acrylate (A1) and the polymerizable monomer (A2) in the conductive paste.
• the amount is not more than 7 parts by weight, more preferably not more than 7 parts by weight, even more preferably not more than 6 parts by weight.
• the content of the thermal polymerization initiator (C) is not less than the above lower limit and not more than the above upper limit, reactivity and storage stability can be improved.
• the conductive paste may contain components other than the (A) curable compound, the plurality of (B) conductive particles, and the (C) thermal polymerization initiator.
• the above conductive paste contains other components such as a solvent, a photopolymerization initiator, an inorganic filler, an organic filler, a colorant, a polymerization inhibitor, a chain transfer agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a leveling agent, and an interface. It may contain an activator, a slip agent, an anti-blocking agent, a wax, a masking agent, a deodorant, a fragrance, a preservative, an antibacterial agent, an antistatic agent, an adhesion agent, and the like.
• the use according to the invention is the use of the above-described conductive paste for bonding chips with a planar area of 0.50 mm 2 or less.
• a specific conductive paste and a chip with a specific planar area are used, it is possible to improve the adhesion (between the substrate and the chip) and improve the continuity reliability.
• the planar area of the chip is preferably 0.04 mm 2 or more, more preferably 0.09 mm 2 or more. , more preferably 0.16 mm 2 or more, preferably 0.50 mm 2 or less, more preferably 0.40 mm 2 or less, still more preferably 0.30 mm 2 or less.
• the use according to the invention is also the use of the above-mentioned conductive paste for obtaining an RFID inlay.
• a specific conductive paste is used, it is possible to improve the adhesion (between the substrate and the chip) and the reliability of conduction.
• the RFID inlay according to the present invention includes a substrate having wiring on the surface, a chip, and an adhesive part that adheres the substrate and the chip.
• the material of the adhesive portion is the conductive paste described above.
• the wiring and the chip are electrically connected by the conductive particles in the adhesive portion.
• the method for manufacturing an RFID inlay includes the following steps (1) to (3).
• an adhesion step for electrically connecting the electrically conductive particles is provided.
• the substrate is elongated, and in the first arrangement step, the second arrangement step, and the bonding step, the elongated substrate is processed by a roll-to-roll method.
• the RFID inlay is manufactured by transport.
• a plurality of RFID inlays can be manufactured continuously, and the manufacturing efficiency of RFID inlays can be further improved.
• the transport speed of the substrate is not particularly limited.
• Examples of methods for disposing the conductive paste include application using a dispenser, screen printing, and ejection using an inkjet device.
• the heating temperature in the bonding step is preferably 100°C or higher, more preferably 150°C or higher, preferably 400°C or lower, more preferably 300°C or lower, and even more preferably 250°C or lower.
• the heating temperature in the bonding step is not less than the lower limit and not more than the upper limit, good electrical connection between the chip and the antenna can be achieved.
• the pressurizing pressure in the bonding step is preferably 0.5N or more, more preferably 1N or more, and preferably 3.5N or less, more preferably 3N or less, and still more preferably 2.5N or less.
• the pressurizing pressure in the bonding step is equal to or higher than the lower limit and lower than the upper limit, good electrical connection between the chip and the antenna can be achieved.
• the heating and pressurizing times in the bonding step are not particularly limited.
• the heating and pressurizing time in the bonding step may be 5 seconds or more, 15 seconds or less, or 10 seconds or less.
• the above-mentioned RFID inlay may be cut to a predetermined size as necessary, or may be used after being cut.
• a plurality of the chips are bonded onto a long substrate using a plurality of bonding portions.
• a plurality of laminates of the chips and the adhesive portions may be arranged on a long substrate.
• the conductive paste is preferably arranged at a plurality of locations on the surface of the elongated substrate.
• the substrate is a circuit board.
• the circuit board include a resin film, a flexible printed board, a rigid-flexible board, a glass substrate, and a paper board.
• the base material may be a resin substrate, a glass substrate, or a paper substrate.
• the above board has wiring (antenna pattern) on the surface.
• Wiring (antenna pattern) is formed on the surface of the base material.
• the substrate preferably includes a base material and wiring (antenna pattern) arranged on the surface of the base material.
• the material for the base material examples include resin, glass, paper, and the like.
• the resin examples include PET (polyethylene terephthalate), PP (polypropylene), PVC (polyvinyl chloride), and the like.
• the paper may be impregnated with epoxy resin or phenolic resin.
• the material of the base material is preferably resin or paper, and preferably PET (polyethylene terephthalate) or paper. is more preferable.
• the base material may be resin, glass, or paper.
• Examples of the wiring (antenna pattern) include gold wiring, nickel wiring, tin wiring, aluminum wiring, silver wiring, SUS wiring, copper wiring, molybdenum wiring, and tungsten wiring. From the viewpoint of improving the operating sensitivity in the UHF band (860 MHz to 920 MHz), the wiring is preferably an aluminum wiring.
• the thickness of the substrate is preferably 20 ⁇ m or more, more preferably 30 ⁇ m or more, and preferably is 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 an RFID inlay by a roll-to-roll method, the substrate and the base material are preferably elongated. The lengths of the substrate and the base material are 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 20 mN/m or more, more preferably 30 mN/m or more, even more preferably 32 mN/m or more, particularly preferably 34 mN/m or more, and preferably 50 mN/m or less. , more preferably 48 mN/m or less, still more preferably 45 mN/m or less.
• adhesiveness can be further improved.
• the conductive paste according to the present invention can be suitably used for application to a substrate (base material) whose surface tension is greater than or equal to the above lower limit and less than or equal to the above upper limit.
• the surface tension of the substrate (base material) can be measured by the following method in accordance with JIS K6768. Dip a cotton swab in the JIS standard solution and apply it to the substrate (base material). The surface tension is determined from the shape of the coating film 2 seconds after application.
• Examples of the above chip include semiconductor chips (IC chips) and the like.
• the chip has an electrode on its surface.
• the electrodes include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, silver electrodes, SUS electrodes, copper electrodes, molybdenum electrodes, and tungsten electrodes.
• 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 the electrodes per chip may be 1 or more, 4 or more, 20 or less, or 10 or less.
• the shape of the chip is not particularly limited.
• the shape of the chip may be rectangular, triangular, or circular.
• the planar area of the chip is preferably 0.04 mm 2 or more, more preferably 0.09 mm 2 or more, even more preferably 0.16 mm 2 or more, and preferably 0.50 mm 2 or less, more preferably 0.40 mm 2 It is more preferably 0.30 mm 2 or less.
• the planar area of the chip is equal to or larger than the lower limit, the conductive paste can be placed on fine wiring with high precision.
• the planar area of the chip is equal to or less than the above upper limit, conduction reliability can be maintained even when the RFID inlay is left in a high temperature and high humidity environment for a long time.
• the conductive paste according to the present invention can be suitably used for bonding relatively small chips.
• Urethane (meth)acrylate UN-9200A (manufactured by Negami Kogyo Co., Ltd., molecular weight (weight average molecular weight): 15,000, viscosity: 1,900,000 mPa ⁇ s)
• A2 Polymerizable monomer: 2-phenoxyethyl acrylate (polymerizable monomer with aromatic skeleton, molecular weight: 192, viscosity: 10 mPa ⁇ s) Isobornyl acrylate (polymerizable monomer with alicyclic skeleton, molecular weight: 208, viscosity: 9 mPa ⁇ s)
• DPHA NS manufactured by Sartomer, polymerizable monomer without aromatic skeleton and alicyclic skeleton, molecular weight (weight average molecular weight): 547, viscosity: 7800 mPa ⁇ s)
• X-22-164 manufactured by Shin-Etsu Silicone Co., Ltd., polymerizable monomer without aromatic skeleton and alicyclic skeleton, molecular weight (weight average molecular weight): 390, viscosity: 55 mPa ⁇ s)
• Conductive particles NIELB-005-S (manufactured by Sekisui Chemical Co., Ltd., conductive particles comprising a base particle and a conductive part on the surface of the base particle, nickel content in 100% by weight of the conductive part: 52% by weight, average particle Diameter: 5 ⁇ m) CN050 (manufactured by Nikko Rica, metal particles (nickel particles), average particle size: 5 ⁇ m) AG6-11 (manufactured by DOWA Electronics, metal particles (silver particles), average particle size: 5 ⁇ m)
• Chip IC chip (copper electrode, “UCODE7” manufactured by NXP, flat area: 0.22 mm 2 )
• PET film PET film
• PP film in the table, long shape, resin film with aluminum wiring whose operating frequency is UHF band (860 MHz to 920 MHz), surface tension: 43 mN/m
• PP film in the table, long shape, resin film with aluminum wiring whose operating frequency is UHF band (860 MHz to 920 MHz), surface tension: 22 mN/m
• Example 1 Preparation of conductive paste The materials shown in Table 1 below are mixed in the amounts shown in Table 1 below, and stirred using a planetary stirring device ("Awatori Rentaro" manufactured by Shinky Co., Ltd.). Thus, a conductive paste (anisotropic conductive paste) was obtained.
• the wiring on the surface of the PET film and the electrode on the surface of the chip were electrically connected by conductive particles in the adhesive part to obtain a connected structure (adhesion step).
• the first arrangement step, the second arrangement step, and the bonding step were performed using "DDA40000” manufactured by Muhlbauer.
• the obtained connected structure was cut into a size of 5 cm x 1.5 cm using "DCL30000” manufactured by Muhlbauer to obtain an RFID inlay.
• Examples 2 to 8 and Comparative Examples 1 to 4 A conductive paste and an RFID inlay were obtained in the same manner as in Example 1, except that the ingredients and content of the conductive paste and the type of substrate (substrate) were changed as shown in Tables 1 to 3.
• Viscosity at 25°C The viscosity at 25°C of the obtained conductive paste was measured at 25°C and 5 rpm using an E-type viscometer (“TV22 type viscometer” manufactured by Toki Sangyo Co., Ltd.). did. Note that the viscosity of the conductive paste obtained in Comparative Example 2 could not be measured because it was not mixed uniformly.
• Storage elastic modulus is 1.5 GPa or more and 3.0 GPa or less
• Storage elastic modulus is 0.7 GPa or more and less than 1.5 GPa
• Storage elastic modulus is less than 0.7 GPa or more than 3.0 GPa
• Adhesiveness (die shear strength)
• the resulting RFID inlay was peeled from the substrate using a die shear tester ("DAGE4000PLUS" manufactured by Nordson) at a tool height of 30 ⁇ m and a speed of 100 ⁇ m/sec, and the die shear strength at 25°C was measured. was evaluated. Adhesion (die shear strength) was determined based on the following criteria. Note that the conductive paste obtained in Comparative Example 2 could not be mixed uniformly, so the die shear strength could not be measured.
• Die shear strength is 7.0N or more
• Die shear strength is 4.0N or more and less than 7.0N
• Die shear strength is less than 4.0N
• the obtained RFID inlay was placed in a dark box that blocks external radio waves, and was measured at 25°C in the UHF band (860MHz to 920MHz) using a frequency reader (Tagformance Pro manufactured by Voyantic). The peak sensitivity was measured and used as the initial peak sensitivity. In addition, after leaving the obtained RFID inlay at 85°C and 85% (high temperature and high humidity environment) for 72 hours, after leaving it for 168 hours, and after leaving it for 500 hours, the peak sensitivity at 25°C in the UHF band was similarly determined. It was measured.
• the continuity reliability was determined based on the following criteria.
• Peak sensitivity is less than -18 dBm ⁇ : Peak sensitivity is -18 dBm or more and less than -17 dBm ⁇ : Peak sensitivity is -17 dBm or more

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• 2023
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