WO2024029513A1 - Electroconductive adhesive and electromagnetic shield film - Google Patents

Electroconductive adhesive and electromagnetic shield film Download PDF

Info

Publication number
WO2024029513A1
WO2024029513A1 PCT/JP2023/028059 JP2023028059W WO2024029513A1 WO 2024029513 A1 WO2024029513 A1 WO 2024029513A1 JP 2023028059 W JP2023028059 W JP 2023028059W WO 2024029513 A1 WO2024029513 A1 WO 2024029513A1
Authority
WO
WIPO (PCT)
Prior art keywords
conductive adhesive
main surface
less
conductive
present
Prior art date
Application number
PCT/JP2023/028059
Other languages
French (fr)
Japanese (ja)
Inventor
茂樹 竹下
晃司 高見
Original Assignee
タツタ電線株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by タツタ電線株式会社 filed Critical タツタ電線株式会社
Publication of WO2024029513A1 publication Critical patent/WO2024029513A1/en

Links

Images

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
    • 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
    • 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
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/10—Adhesives in the form of films or foils without carriers
    • 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
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • 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
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields

Definitions

  • the present invention relates to a conductive adhesive and an electromagnetic shielding film.
  • an electromagnetic shielding film (hereinafter sometimes simply referred to as a "shielding film”) that is used by adhering to a printed wiring board consists of a shielding layer such as metal foil and a conductive adhesive provided on the surface of the shielding layer. It has a sheet.
  • the conductive adhesive sheet is formed, for example, by applying a conductive adhesive in sheet form to the surface of the shield layer, and it adheres the shield layer to the surface of the printed wiring board, and also connects the ground pattern of the printed wiring board and the shield layer. It has the function of conducting.
  • Patent Document 1 discloses a conductive adhesive sheet having a storage modulus peak top temperature of 120° C. or less and an average arithmetic surface roughness Ra of the application surface of 0.1 ⁇ m or more. Disclosed.
  • a metal layer serving as a shield layer is laminated and placed on a printed wiring board.
  • the laminate of the conductive adhesive sheet and the shield layer is temporarily attached to the printed wiring board by laminating or the like, and then heated and pressurized at high temperature to harden the conductive adhesive sheet. This fixes the laminate of the conductive adhesive sheet and the shield layer to the printed wiring board.
  • temporary bonding is performed in this way, if the adhesive strength is weak during temporary bonding, the laminate of the conductive adhesive sheet and shield layer may become misaligned with respect to the printed wiring board before the main curing process. , it may fall off the printed wiring board.
  • the above problem is prevented by setting the peak top temperature of the storage elastic modulus and the average arithmetic surface roughness of the attachment surface to predetermined values.
  • Patent Document 1 discloses a conductive adhesive sheet using a thermosetting resin as a binder component.
  • a thermosetting resin as a binder component.
  • thermosetting resin When a thermosetting resin is used as a binder, the thermosetting resin is cured by heat, so it has a characteristic of high creep resistance.
  • an adhesive resin when used as a binder component, there is a problem that creep resistance is low because the adhesive resin does not harden like a thermosetting resin.
  • Electromagnetic shielding films containing adhesive resin are sometimes used for movable parts and bent parts on FFCs and printed wiring boards. Tensile stress is likely to be applied to the electromagnetic shielding film placed in such a location. Furthermore, when the electromagnetic shielding film is placed close to a heat source, it becomes susceptible to heat. When an electromagnetic shielding film is placed in such a location, creep resistance becomes a particular problem.
  • one possible method to improve creep resistance is to use a material that is difficult to deform, but there is a problem that using a material that is difficult to deform reduces adhesive strength. be. That is, there is a trade-off relationship between improving creep resistance and improving adhesiveness, and it has been difficult to achieve both.
  • the present invention was made to solve the above problems, and an object of the present invention is to provide a conductive adhesive that has both high creep resistance and high adhesiveness at high temperatures. It is to provide.
  • the present inventors have found that by setting the storage modulus of the conductive adhesive to a predetermined value and setting the adhesive surface of the conductive adhesive to a predetermined state, the creep resistance of the conductive adhesive is increased, and It was discovered that the adhesiveness also increased, and the present invention was completed.
  • the conductive adhesive of the present invention is a sheet-shaped conductive adhesive that includes conductive particles and a resin composition, and has a first main surface and a second main surface opposite to the first main surface.
  • the electrically conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and an arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a maximum height Rz of the first principal surface is 16 ⁇ m or less. .
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the maximum peak height Rp of the first principal surface is 9.5 ⁇ m or less. shall be.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a maximum valley depth Rv of the first principal surface is 9 ⁇ m or less. do.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the average height Rc of the first principal surface is 11 ⁇ m or less. .
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the maximum cross-sectional height Rt of the first principal surface is 16 ⁇ m or less. do.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the root mean square height Rq of the first principal surface is 5 ⁇ m or less. shall be.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the ten-point average roughness RzJIS of the first principal surface is 14 ⁇ m or less. shall be.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the level difference Rk of the core portion of the first principal surface is 7 ⁇ m or less. shall be.
  • a conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the average length Rdc of the elements on the first principal surface is 7 ⁇ m or less. shall be.
  • the electrically conductive adhesive of the present invention has in common that the storage modulus at 65° C. is 1.6 ⁇ 10 4 Pa or more. Therefore, when the storage modulus of the conductive adhesive at 65° C. is within the above range, the conductive adhesive becomes difficult to deform and has high creep resistance at high temperatures.
  • the surface quality parameters (Ra, Rz, Rp, Rv, Rc, Rt, Rq, RzJIS, Rk, Rdc) of the first main surface are within predetermined ranges.
  • the fact that these parameters are within the above ranges means that the first principal surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive pressure-sensitive adhesive of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the conductive adhesive of the present invention may have isotropic conductivity or anisotropic conductivity depending on its use.
  • the electromagnetic shielding film of the present invention is characterized by comprising the conductive adhesive of the present invention and a shield layer laminated so as to be in contact with the second main surface of the conductive adhesive.
  • the conductive adhesive of the present invention has high creep resistance and high adhesiveness at high temperatures. Therefore, the shield layer can be reliably bonded to the adherend.
  • the electromagnetic shielding film of the present invention preferably further includes a protective layer formed on the shielding layer.
  • a protective layer formed on the shielding layer.
  • FIG. 1 is a cross-sectional view schematically showing an example of a conductive adhesive according to a first embodiment of the present invention.
  • FIG. 2 is a cross-sectional view schematically showing an example of the electromagnetic shielding film according to the first embodiment of the present invention.
  • FIG. 3 is a cross-sectional view schematically showing an example of a shield printed wiring board including an electromagnetic shielding film according to the first embodiment of the present invention.
  • the conductive adhesive of the present invention will be specifically explained.
  • the present invention is not limited to the following embodiments, and can be modified and applied as appropriate without changing the gist of the present invention.
  • the conductive adhesive according to the first embodiment of the present invention is made of conductive particles and a resin composition, and has a first main surface and a second main surface opposite to the first main surface.
  • the conductive adhesive must have a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65°C and an arithmetic mean roughness Ra of the first principal surface of 4 ⁇ m or less. This is a configuration requirement. As long as these constituent requirements are satisfied, the present invention can be modified and applied as appropriate within the scope of producing the effects of the invention.
  • FIG. 1 is a cross-sectional view schematically showing an example of a conductive adhesive according to a first embodiment of the present invention.
  • the conductive adhesive 10 shown in FIG. 1 consists of conductive particles and a resin composition. Further, the conductive adhesive 10 is in the form of a sheet, and has a first main surface 11 and a second main surface 12 opposite to the first main surface 11.
  • the conductive adhesive 10 has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C.
  • the storage elastic modulus is preferably 1.6 ⁇ 10 4 to 1.0 ⁇ 10 5 Pa or less, more preferably 1.6 ⁇ 10 4 Pa to 9.0 ⁇ 10 4 Pa. .
  • the storage modulus at 65° C. is 1.6 ⁇ 10 4 Pa or more, the conductive adhesive becomes difficult to deform and has high creep resistance at high temperatures.
  • the "storage modulus at 65°C” can be measured with a dynamic viscoelasticity measuring device (rheometer).
  • the storage modulus of the conductive adhesive 10 at 65° C. can be controlled by adjusting the type and content of the resin composition contained in the conductive adhesive 10 or by adding additives.
  • the arithmetic mean roughness Ra of the first main surface 11 is 4 ⁇ m or less.
  • the arithmetic mean roughness Ra is preferably 3.97 ⁇ m or less, more preferably 3.65 ⁇ m or less.
  • the arithmetic mean roughness Ra of the first main surface 11 is 4 ⁇ m or less, it can be said that the first main surface 11 is nearly flat. Therefore, when an adherend is brought into contact with the first main surface 11, the first main surface 11 and the adherend are likely to come into close contact with each other. Therefore, the adhesive force on the first main surface 11 of the conductive adhesive 10 becomes high.
  • the maximum height Rz of the first main surface 11 is preferably 16 ⁇ m or less, more preferably 15.5 ⁇ m or less, and even more preferably 15 ⁇ m or less.
  • the maximum peak height Rp of the first main surface 11 is preferably 9.5 ⁇ m or less, more preferably 8.6 ⁇ m or less, and even more preferably 7.5 ⁇ m or less.
  • the maximum valley depth Rv of the first main surface 11 is preferably 9 ⁇ m or less, more preferably 8.8 ⁇ m or less, and even more preferably 7 ⁇ m or less.
  • the average height Rc of the first main surface 11 is preferably 11 ⁇ m or less, more preferably 10.6 ⁇ m or less, and even more preferably 10.3 ⁇ m or less.
  • the maximum cross-sectional height Rt of the first main surface 11 is preferably 16 ⁇ m or less, more preferably 15.5 ⁇ m or less, and even more preferably 15 ⁇ m or less.
  • the root mean square height Rq of the first principal surface 11 is preferably 5 ⁇ m or less, more preferably 4.5 ⁇ m or less, and even more preferably 4.1 ⁇ m or less.
  • the ten-point average roughness RzJIS of the first main surface 11 is preferably 14 ⁇ m or less, more preferably 13.5 ⁇ m or less, and even more preferably 13.3 ⁇ m or less.
  • the level difference Rk of the core portion of the first main surface 11 is preferably 7 ⁇ m or less, more preferably 6.8 ⁇ m or less, and even more preferably 6.5 ⁇ m or less.
  • the average length Rdc of the elements of the first main surface 11 is preferably 7 ⁇ m or less, more preferably 6.6 ⁇ m or less, and even more preferably 6.3 ⁇ m or less.
  • the arithmetic mean roughness Ra of the first principal surface 11 is 4 ⁇ m or less, so even if the storage modulus at 65° C. is 1.6 ⁇ 10 4 Pa or more, sufficient adhesiveness is not achieved. shows. That is, it can be said that the conductive adhesive 10 has high creep resistance at high temperatures and high adhesiveness, which are both compatible.
  • the arithmetic mean roughness Ra of the second main surface 12 is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and even more preferably 3.65 ⁇ m or less.
  • the maximum height Rz of the second main surface 12 is preferably 16 ⁇ m or less, more preferably 15.5 ⁇ m or less, and even more preferably 15 ⁇ m or less.
  • the maximum peak height Rp of the second main surface 12 is preferably 9.5 ⁇ m or less, more preferably 8.6 ⁇ m or less, and even more preferably 7.5 ⁇ m or less.
  • the maximum valley depth Rv of the second main surface 12 is preferably 9 ⁇ m or less, more preferably 8.8 ⁇ m or less, and even more preferably 7 ⁇ m or less.
  • the average height Rc of the second main surface 12 is preferably 11 ⁇ m or less, more preferably 10.6 ⁇ m or less, and even more preferably 10.3 ⁇ m or less.
  • the maximum cross-sectional height Rt of the second main surface 12 is preferably 16 ⁇ m or less, more preferably 15.5 ⁇ m or less, and even more preferably 15 ⁇ m or less.
  • the root mean square height Rq of the second principal surface 12 is preferably 5 ⁇ m or less, more preferably 4.5 ⁇ m or less, and even more preferably 4.1 ⁇ m or less.
  • the ten-point average roughness RzJIS of the second main surface 12 is preferably 14 ⁇ m or less, more preferably 13.5 ⁇ m or less, and even more preferably 13.3 ⁇ m or less.
  • the level difference Rk of the core portion of the second main surface 12 is preferably 7 ⁇ m or less, more preferably 6.8 ⁇ m or less, and even more preferably 6.5 ⁇ m or less.
  • the average length Rdc of the elements of the second main surface 12 is preferably 7 ⁇ m or less, more preferably 6.6 ⁇ m or less, and even more preferably 6.3 ⁇ m or less.
  • the adhesive force of the second main surface 12 becomes high.
  • Ra, Rz, Rp, Rv, Rc, Rt, Rq, RzJIS and Rdc are parameters defined in JIS B 0601:2013
  • Rk is a parameter defined in JIS B0671-2:2002, and can be measured using analysis software attached to a surface shape measuring device such as a confocal microscope (OPTELICS HYBRID, manufactured by Lasertec).
  • the surface properties such as the arithmetic mean roughness Ra of the first main surface 11 are controlled by adjusting the content, size, shape, etc. of the conductive particles. be able to.
  • the conductive adhesive 10 may have isotropic conductivity or anisotropic conductivity depending on its use. As will be described in detail later, by adjusting the size, content, etc. of the conductive particles contained in the conductive adhesive 10, the conductive adhesive 10 can be made into a conductive adhesive having isotropic conductivity. It can be made into a conductive adhesive having anisotropic conductivity.
  • the thickness of the conductive adhesive 10 is preferably determined appropriately depending on the application, but from the viewpoint of creep resistance and adhesiveness, it is preferably 3 to 100 ⁇ m, more preferably 5 to 50 ⁇ m. .
  • the conductive particles are not particularly limited, and examples thereof include metal particles, metal-coated resin particles, carbon filler, and the like.
  • Examples of the metal constituting the coating portion of the metal particles and metal-coated resin particles include gold, silver, copper, nickel, and zinc.
  • the above metals may be used alone or in combination of two or more.
  • the metal particles include copper particles, silver particles, nickel particles, silver-coated copper particles, gold-coated copper particles, silver-coated nickel particles, gold-coated nickel particles, and silver-coated alloy particles.
  • the silver-coated alloy particles include silver-coated copper alloy particles in which alloy particles containing copper (for example, copper alloy particles made of an alloy of copper, nickel, and zinc) are coated with silver.
  • Metal particles can be produced by an electrolysis method, an atomization method, a reduction method, or the like.
  • silver particles silver particles, silver-coated copper particles, and silver-coated copper alloy particles are preferable.
  • Silver-coated copper particles and silver-coated copper alloy particles are particularly preferred from the viewpoints of excellent conductivity, suppressing oxidation and aggregation of metal particles, and lowering the cost of metal particles.
  • the content, size, shape, etc. of the conductive particles affect the arithmetic mean roughness Ra of the first main surface 11.
  • the arithmetic mean roughness Ra of the first main surface 11 can be set to 4 ⁇ m or less.
  • the content of the conductive particles is preferably 5 to 85% by weight, and 5 to 70% by weight, for example. It is more preferable that
  • the median diameter (D 50 ) of the conductive particles is preferably 3 to 100 ⁇ m, and preferably 5 to 50 ⁇ m. It is more preferable that
  • the median diameter (D 50 ) of conductive particles means the particle diameter at 50% of the integrated value in the particle size distribution determined by laser diffraction/scattering method.
  • the shape of the conductive particles is not particularly limited, and may be spherical (true sphere, ellipsoid, etc.), flake (scaly, flat, etc.), dendritic (dendritic), fibrous, filamentary, amorphous ( polyhedron).
  • spherical, flake, dendrite, and filament shapes are preferable.
  • the content, size, and shape of the conductive particles also affect whether the conductive adhesive has isotropic conductivity or anisotropic conductivity.
  • a method may be used in which the content of conductive particles is adjusted to 50 to 85% by weight.
  • anisotropic conductivity to the conductive adhesive a method may be mentioned in which the content of conductive particles is set to 5% by weight or more and less than 49% by weight.
  • the content, size, and shape of the conductive particles are preferably determined as appropriate depending on the use of the conductive adhesive and desired performance.
  • the resin composition is not particularly limited as long as it has adhesive properties, but at least one resin selected from the group consisting of natural rubber, acrylic resin, polyurethane resin, silicone resin, and polyester resin. Preferably, it contains a resin. Among these, acrylic resins and silicone resins are more preferred.
  • the acrylic resin preferably has a glass transition temperature (Tg) of 0°C or lower, more preferably -5°C or lower, and even more preferably -10°C or lower. If the glass transition temperature of the acrylic resin exceeds 0° C., the adhesive strength will be low when attached to an adherend under low pressure and temperature conditions. Note that the glass transition temperature of the acrylic resin is determined by differential scanning calorimetry.
  • the acid value of the acrylic resin is not particularly limited, but is preferably 5 mgKOH/g or less, more preferably 1 to 5 mgKOH/g, and even more preferably 1 to 3 mgKOH/g.
  • the acid value of the acrylic resin is 5 mgKOH/g or less, the curing of the acrylic resin by the curing agent will not proceed excessively, so it can be easily adhered to the adherend, and the adhesive strength to the adherend is improved. do.
  • the weight average molecular weight of the acrylic resin is not particularly limited, but is preferably from 100,000 to 1,000,000, more preferably from 200,000 to 600,000. When the weight average molecular weight is within the above range, the adhesive strength to an adherend is improved.
  • the weight average molecular weight of the acrylic resin can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.
  • acrylic resin refers to a polymer composed of a (meth)acrylate compound as a monomer component, that is, a polymer (or copolymer) having a structural unit derived from a (meth)acrylate compound. ).
  • (meth)acrylate means acrylate and/or methacrylate.
  • (meth)acrylate compound refers to a compound having an acryloyl group and/or a methacryloyl group. The same applies to "(meth)acrylic".
  • the acrylic resin may consist of only one type of (meth)acrylate compound, or may consist of two or more types.
  • Examples of the above (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, and (meth)acrylate.
  • the above (meth)acrylate compounds include neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, )
  • Polyfunctional (meth)acrylates such as acrylates are also included. Further examples include 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, phenylglycidyl ether (meth)acrylate hexamethylene diisocyanate urethane prepolymer, and bisphenol A diglycidyl ether acrylic acid adduct.
  • the acrylic resin may have a structural unit derived from a monomer component other than the (meth)acrylate compound.
  • monomer components are not particularly limited, but include, for example, carboxyl group-containing polymerizable unsaturated compounds such as crotonic acid, itaconic acid, fumaric acid, and maleic acid, or their anhydrides; styrene, vinyltoluene, ⁇ - Styrenic compounds such as methylstyrene; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl halides such as vinyl chloride; Vinyl ethers such as methyl vinyl ether; Cyano group-containing vinyl compounds such as (meth)acrylonitrile; ethylene, propylene ⁇ -olefins such as
  • the content of the resin composition in the conductive adhesive 10 is not particularly limited, but is preferably 15 to 95% by weight, and 30 to 95% by weight, based on 100% by weight of the total solid content in the resin composition. It is more preferably 95% by weight, and even more preferably 30 to 85% by weight. If the content is less than 15% by weight, the adhesive strength to the adherend will decrease. When the content exceeds 95% by weight, the proportion of conductive particles becomes relatively small, resulting in a decrease in electrical stability.
  • the conductive adhesive 10 may optionally contain a curing agent, a flame retardant, a plasticizer, an antifoaming agent, a viscosity modifier, an antioxidant, a diluent, an antisettling agent, It may also contain fillers, colorants, leveling agents, coupling agents, tackifiers, and the like.
  • the curing agent is not particularly limited, but when the resin composition is an acrylic resin, an isocyanate curing agent can be used.
  • the isocyanate curing agent is a compound having two or more isocyanate groups in the molecule, and promotes curing of the acrylic resin. Only one type of isocyanate curing agent may be used, or two or more types may be used.
  • isocyanate curing agent examples include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, Alicyclic polyisocyanates such as hydrogenated toluene diisocyanate and hydrogenated xylylene diisocyanate; aromatic polyisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, etc. Can be mentioned.
  • lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate
  • the content of the isocyanate curing agent is preferably 0.05 to 5.0 parts by weight, more preferably 0.1 to 4.0 parts by weight, and 1.0 parts by weight based on 100 parts by weight of the acrylic resin. More preferably, the amount is 3.5 parts by weight.
  • the content of the isocyanate curing agent is 0.05 parts by weight or more, the acrylic resin can be appropriately cured, and the storage modulus at 65° C. of the conductive adhesive 10 is 1.6 ⁇ 10 It becomes easier to increase the pressure to 4 Pa or higher.
  • the content of the isocyanate curing agent is 5.0 parts by weight or less, the curing agent suppresses excessive curing of the acrylic resin and improves adhesive strength.
  • FIG. 2 is a cross-sectional view schematically showing an example of the electromagnetic shielding film according to the first embodiment of the present invention.
  • the electromagnetic wave shielding film 40 shown in FIG. A layer 30 is provided. Note that in the electromagnetic shielding film 40, the first main surface 11 of the conductive adhesive 10 is the surface that comes into contact with the adherend.
  • the conductive adhesive 10 has high creep resistance and high adhesiveness at high temperatures. Therefore, the shield layer 20 can be reliably bonded to the adherend.
  • the shield layer 20 and the conductive adhesive 10 can be protected.
  • shield layer 20 The structure of the shield layer 20 is not particularly limited as long as it can shield electromagnetic waves by reflecting or absorbing them, but it is preferably a metal layer, for example.
  • Examples of the metal constituting such a metal layer include gold, silver, copper, aluminum, nickel, tin, palladium, chromium, titanium, zinc, and alloys thereof.
  • a copper layer and a silver layer are preferred from the viewpoint of superior electromagnetic shielding effect, and copper is more preferred from the viewpoint of economy.
  • the material and thickness of the metal layer may be appropriately determined depending on the required electromagnetic shielding effect and repeated bending/sliding resistance.
  • the thickness of the metal layer is preferably 0.1 ⁇ m or more. Further, from the viewpoint of productivity, flexibility, etc., it is preferable that the thickness is 12 ⁇ m or less.
  • the metal layer can be formed by an electrolytic plating method, an electroless plating method, a sputtering method, an electron beam evaporation method, a vacuum evaporation method, a CVD method, a metal organic method, or the like.
  • the metal layer can also be formed from metal foil, metal nanoparticles, scaly metal particles, or the like.
  • the protective layer 30 is made of a resin material, has insulation properties, and satisfies predetermined mechanical strength, chemical resistance, and heat resistance.
  • the resin material constituting the protective layer 30 is not particularly limited as long as it has sufficient insulation, but examples include thermoplastic resin compositions, thermosetting resin compositions, and active energy ray-curable compositions. Can be used.
  • Thermoplastic resin compositions include, but are not particularly limited to, styrene resin compositions, vinyl acetate resin compositions, polyester resin compositions, polyethylene resin compositions, polypropylene resin compositions, imide resin compositions, Also, acrylic resin compositions and the like can be used.
  • the thermosetting resin composition is not particularly limited, but phenolic resin compositions, epoxy resin compositions, urethane resin compositions, melamine resin compositions, alkyd resin compositions, etc. can be used. can.
  • the active energy ray-curable composition is not particularly limited, but for example, a polymerizable compound having at least two (meth)acryloyloxy groups in the molecule can be used. These compositions may be used alone or in combination of two or more.
  • the protective layer 30 contains a curing accelerator, a tackifier, an antioxidant, a pigment, a dye, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling agent, a filler, a flame retardant, and a viscosity adjuster, as necessary. and an antiblocking agent may also be included.
  • the protective layer has an arbitrary structure, and the protective layer does not need to be formed.
  • the electromagnetic shielding film of the present invention is attached to an adherend by the adhesive force of the conductive adhesive of the electromagnetic shielding film. Even after the electromagnetic shielding film of the present invention is attached to an adherend, the conductive adhesive does not harden and remains flexible. Therefore, even if the electromagnetic shielding film of the present invention is applied to a movable part and the movable part moves, the electromagnetic shielding film of the present invention will not be easily damaged and will not easily peel off from the movable part. Therefore, the electromagnetic shielding film of the present invention is suitable as an electromagnetic shielding film to be attached to a movable part.
  • a method for manufacturing the electromagnetic shielding film of the present invention will be explained.
  • conductive particles and a resin composition are mixed to prepare a conductive adhesive composition.
  • a solvent and other additives may be added to the conductive adhesive composition.
  • solvent examples include xylene, toluene, tert-butyl alcohol, ethyl acetate, and methyl ethyl ketone.
  • a conductive adhesive composition is applied onto the first base material such as a separator film, and if necessary, the solvent is removed and/or partially cured by heating or the like to form a conductive adhesive.
  • the above heating is preferably performed at, for example, 25 to 100° C. for about 1 to 72 hours.
  • a known coating method can be used to apply the conductive adhesive composition.
  • coaters such as a gravure roll coater, reverse roll coater, kiss roll coater, lip coater dip roll coater, bar coater, knife coater, spray coater, comma coater, direct coater, and slot die coater can be used.
  • the main surface of the conductive adhesive on the side that is in contact with the base material is the first main surface, and the main surface of the conductive adhesive on the side that is not in contact with the base material is the second main surface.
  • a composition for forming a protective layer is applied or laminated onto the second base material, and a shield layer is further formed on the protective layer.
  • Conventionally known methods can be used for applying and laminating the composition for forming the protective layer and for forming the shield layer.
  • the electromagnetic shielding film of the present invention can be manufactured by laminating the adhesive composition formed on the first base material and the shielding layer of the second base material.
  • the electromagnetic shielding film manufactured in this way When attaching the electromagnetic shielding film manufactured in this way to an adherend, first, the first base material is peeled off, and the adherend is brought into contact with the first main surface of the conductive adhesive. At this time, pressure is applied to the electromagnetic shielding film so that the electromagnetic shielding film does not peel off from the adherend. After that, the second base material is peeled off. Thereby, the electromagnetic shielding film of the present invention can be attached to an adherend.
  • FIG. 3 is a cross-sectional view schematically showing an example of a shield printed wiring board including an electromagnetic shielding film according to the first embodiment of the present invention.
  • a shield printed wiring board 60 shown in FIG. 3 includes a printed wiring board 50 and an electromagnetic shielding film 40.
  • the printed wiring board 50 includes a base film 51, a printed circuit 52 placed on the base film 51, and a coverlay 53 placed so as to cover the printed circuit 52.
  • the printed circuit 52 includes a ground circuit 52a
  • the coverlay 53 has an opening 53a that exposes the ground circuit 52a.
  • the electromagnetic shielding film 40 is arranged on the printed wiring board 50 so that the coverlay 53 and the conductive adhesive 10 are in contact with each other.
  • the conductive adhesive 10 fills the opening 53a of the coverlay 53 and is in contact with the ground circuit 52a. With such a configuration, the shielding characteristics of the electromagnetic shielding film 40 can be improved.
  • both the base film 51 and the coverlay 53 are preferably made of engineering plastic.
  • resins such as polypropylene, crosslinked polyethylene, polyester, polybenzimidazole, polyimide, polyimide amide, polyetherimide, and polyphenylene sulfide (PPS).
  • the printed circuit 52 can be made of a common circuit material such as copper.
  • the base film 51 and the printed circuit 52 may be bonded together using an adhesive, or may be bonded together without using an adhesive, similar to a so-called non-adhesive type copper clad laminate.
  • the coverlay 53 may be formed by bonding a plurality of flexible insulating films together with an adhesive, and is formed by a series of methods such as coating with photosensitive insulating resin, drying, exposure, development, and heat treatment. It may be formed.
  • the electromagnetic shielding film 40 As a method for attaching the electromagnetic shielding film 40 to the printed wiring board 50, a conventionally known method can be employed.
  • the electromagnetic shielding film 40 since the electromagnetic shielding film 40 includes the conductive adhesive 10, it can be attached at relatively low temperatures and pressures such as 23 to 65° C. and 0.1 to 1.0 MPa.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less"
  • the configuration requirements are the same as those of the conductive adhesive according to the first embodiment of the present invention, except that the configuration requirement is changed to "the maximum height Rz of the first principal surface is 16 ⁇ m or less".
  • the conductive adhesive according to the second embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • a conductive adhesive having a shape, characterized in that the storage modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 Pa or more, and the maximum height Rz of the first principal surface is 16 ⁇ m or less. shall be.
  • the maximum height Rz of the first main surface is preferably 15.5 ⁇ m or less, more preferably 15 ⁇ m or less.
  • the fact that the maximum height Rz of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the second embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the second embodiment of the present invention other than these parameters are the same as preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less"
  • the configuration requirements are the same as those of the conductive adhesive according to the first embodiment of the present invention, except that the configuration requirement is changed to "the maximum peak height Rp of the first principal surface is 9.5 ⁇ m or less".
  • the conductive adhesive according to the third embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the conductive adhesive has a storage elastic modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a maximum peak height Rp of the first main surface is 9.5 ⁇ m or less. characterized by something.
  • the maximum peak height Rp of the first main surface is preferably 8.6 ⁇ m or less, more preferably 7.5 ⁇ m or less.
  • the fact that the maximum peak height Rp of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the third embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the third embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the maximum valley depth Rv of the first principal surface is 9 ⁇ m or less". That is, the conductive adhesive according to the fourth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. a conductive adhesive having a storage elastic modulus of 1.6 ⁇ 10 4 Pa or more at 65° C. and a maximum valley depth Rv of the first principal surface of 9 ⁇ m or less. It is characterized by
  • the maximum valley depth Rv of the first main surface is preferably 8.8 ⁇ m or less, more preferably 7 ⁇ m or less.
  • the fact that the maximum valley depth Rv of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the fourth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the fourth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the average height Rc of the first principal surface is 11 ⁇ m or less". That is, the conductive adhesive according to the fifth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the electrically conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and the average height Rc of the first principal surface is 11 ⁇ m or less. It is characterized by
  • the average height Rc of the first main surface is preferably 10.6 ⁇ m or less, more preferably 10.3 ⁇ m or less.
  • the fact that the average height Rc of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the fifth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the fifth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the maximum cross-sectional height Rt of the first principal surface is 16 ⁇ m or less". That is, the conductive adhesive according to the sixth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. a conductive adhesive having a storage elastic modulus of 1.6 ⁇ 10 4 Pa or more at 65° C. and a maximum cross-sectional height Rt of the first principal surface of 16 ⁇ m or less. It is characterized by
  • the maximum cross-sectional height Rt of the first main surface is preferably 15.5 ⁇ m or less, more preferably 15 ⁇ m or less.
  • the fact that the maximum cross-sectional height Rt of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the sixth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the sixth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the root mean square height Rq of the first principal surface is 5 ⁇ m or less". That is, the conductive adhesive according to the seventh embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the electrically conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and the root mean square height Rq of the first principal surface is 5 ⁇ m or less. characterized by something.
  • the root mean square height Rq of the first principal surface is preferably 4.5 ⁇ m or less, more preferably 4.1 ⁇ m or less. .
  • the fact that the root mean square height Rq of the first principal surface is within the above range means that the first principal surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the seventh embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the seventh embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less"
  • the constituent requirement is that "the ten-point average roughness RzJIS of the first principal surface is 14 ⁇ m or less”.
  • the conductive adhesive according to the eighth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the ten-point average roughness RzJIS of the first main surface is preferably 13.5 ⁇ m or less, more preferably 13.3 ⁇ m or less. .
  • the fact that the ten-point average roughness RzJIS of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the eighth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the eighth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less"
  • the configuration requirements are the same as those of the conductive adhesive according to the first embodiment of the present invention, except that the configuration requirement is changed to "the level difference Rk of the core portion of the first principal surface is 7 ⁇ m or less".
  • the conductive adhesive according to the ninth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the conductive adhesive has a storage elastic modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a level difference Rk of the core portion of the first principal surface is 7 ⁇ m or less. characterized by something.
  • the level difference Rk of the core portion of the first main surface is preferably 6.8 ⁇ m or less, more preferably 6.5 ⁇ m or less. .
  • the fact that the level difference Rk of the core portion of the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the ninth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the ninth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 ⁇ m or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except that the constituent requirement is "the average length Rdc of the elements on the first principal surface is 7 ⁇ m or less". That is, the conductive adhesive according to the tenth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface.
  • the electrically conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and the average length Rdc of the elements on the first principal surface is 7 ⁇ m or less. characterized by something.
  • the average length Rdc of the elements on the first main surface is preferably 6.6 ⁇ m or less, more preferably 6.3 ⁇ m or less. .
  • the fact that the average length Rdc of the elements on the first main surface is within the above range means that the first main surface is nearly flat. Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the tenth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
  • the arithmetic mean roughness Ra of the first main surface is preferably 4 ⁇ m or less, more preferably 3.97 ⁇ m or less, and 3.65 ⁇ m or less. It is more preferable that it is the following.
  • Preferred aspects of the conductive adhesive according to the tenth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
  • the present disclosure (1) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and an arithmetic mean roughness Ra of the first principal surface of 4 ⁇ m or less. be.
  • the present disclosure (2) is a sheet-shaped conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a maximum height Rz of the first principal surface is 16 ⁇ m or less. .
  • the present disclosure (3) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, A conductive adhesive characterized in that the storage elastic modulus at 65° C. of the conductive adhesive is 1.6 ⁇ 10 4 Pa or more, and the maximum peak height Rp of the first principal surface is 9.5 ⁇ m or less. It is.
  • the present disclosure (4) is a sheet-shaped conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a maximum valley depth Rv of the first principal surface is 9 ⁇ m or less. be.
  • the present disclosure (5) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and an average height Rc of the first principal surface is 11 ⁇ m or less. .
  • the present disclosure (6) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a maximum cross-sectional height Rt of the first principal surface is 16 ⁇ m or less. be.
  • the present disclosure (7) is a sheet-shaped conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, A conductive adhesive characterized in that the storage elastic modulus at 65° C. of the conductive adhesive is 1.6 ⁇ 10 4 Pa or more, and the root mean square height Rq of the first principal surface is 5 ⁇ m or less. It is.
  • the present disclosure (8) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, A conductive adhesive characterized in that the storage modulus at 65° C. of the conductive adhesive is 1.6 ⁇ 10 4 Pa or more, and the ten-point average roughness RzJIS of the first principal surface is 14 ⁇ m or less. It is.
  • the present disclosure (9) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage elastic modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and a level difference Rk of the core portion of the first principal surface is 7 ⁇ m or less. It is.
  • the present disclosure (10) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface,
  • the conductive adhesive has a storage modulus of 1.6 ⁇ 10 4 Pa or more at 65° C., and an average length Rdc of the elements on the first principal surface is 7 ⁇ m or less. It is.
  • the present disclosure (11) is the conductive adhesive according to any one of the present disclosure (1) to (10), wherein the conductive adhesive has isotropic conductivity or anisotropic conductivity.
  • the present disclosure (12) includes the conductive adhesive according to any one of the present disclosures (1) to (11), and a shield layer laminated so as to be in contact with the second main surface of the conductive adhesive.
  • This is an electromagnetic shielding film that features:
  • the present disclosure (13) is the electromagnetic wave shielding film according to the present disclosure (12), further comprising a protective layer formed on the shield layer.
  • Example 1 As a resin composition for a conductive adhesive, 84.5 parts by weight of an acrylic adhesive, 15 parts by weight of filamentary nickel particles as conductive particles, and 0.5 parts by weight of toluene diisocyanate as a curing agent were mixed. A conductive adhesive composition according to Example 1 was prepared.
  • a separate film made of polyethylene terephthalate whose surface has been treated with a release agent is prepared as a first base material, and a conductive adhesive is applied to the surface of the first base material using an applicator to a thickness of 13 ⁇ m.
  • the composition was applied.
  • a separate film made of polyethylene terephthalate whose surface has been treated with a release agent is prepared as a second base material, and a protective layer is applied to the surface of the second base material to a thickness of 5 ⁇ m using an applicator.
  • a protective layer was formed by coating a polyester resin, which is a resin composition for Thereafter, a 10 ⁇ m thick copper foil was placed on the protective layer.
  • the conductive adhesive composition placed on the first base material and the copper foil placed on the second base material were pasted together so that they were in contact with each other. Thereafter, aging was performed at 40° C. for 3 days to produce the electromagnetic shielding film according to Example 1. Note that due to aging, the resin composition and curing agent in the conductive pressure-sensitive adhesive composition react to form a conductive pressure-sensitive adhesive.
  • Electromagnetic shielding films according to Examples 2 to 9 and Comparative Examples 1 to 2 were manufactured in the same manner as in Example 1, except that the materials used were changed to the types and blending ratios shown in Tables 1 and 2. .
  • Tables 1 and 2 the numerical values for the composition of the conductive adhesive mean "parts by weight.”
  • the types of materials listed in Tables 1 and 2 are as follows. The median diameter (D 50 ) of Conductive Particles 1 to 3 below was measured using a particle size distribution analyzer (manufactured by Micro Track Bell Co., Ltd., MT3300EXII).
  • Resin composition 1 for protective layer Polyester resin/PET/PSA (black)
  • Resin composition 2 for protective layer Polyester resin/PET/PSA (transparent)
  • Resin composition for conductive adhesive Acrylic adhesive
  • Conductive particles 1 Filament-shaped nickel particles (median diameter (D 50 ): 20 ⁇ m)
  • Conductive particles 2 dendrite-like silver-coated copper particles (median diameter (D 50 ): 12 ⁇ m)
  • Conductive particles 3 Silver-coated copper particles produced by atomization method (median diameter (D 50 ): 5 ⁇ m)
  • Curing agent toluene diisocyanate
  • the first base material was peeled off to expose the first main surface of the conductive adhesive, and the film was exposed to a confocal microscope (manufactured by Lasertec, OPTELICS HYBRID, objective lens 20x). ) to measure five arbitrary locations on the first main surface, then use data analysis software (LMeye7) to measure Ra, Rz, Rp, Rv, Rc, Rt, Rq, RzJIS, Rdc and Rk were measured. The results are shown in Tables 1 and 2.
  • the electromagnetic wave shielding films according to each example and each comparative example were installed in a thermal shock tester (TSA-43EL-A) manufactured by ESPEC Corporation so that a load of 1 kgf was applied, and after being allowed to stand at 0°C for 30 minutes, This process was repeated for 24 cycles in which the sample was allowed to stand for 30 minutes at °C, and a heat cycle test was conducted to evaluate the creep resistance.
  • TSA-43EL-A thermal shock tester
  • peel test A peel test was conducted using the adhesive tape/adhesive sheet test method specified in ASTM D3330. Specifically, the electromagnetic shielding film according to each example and each comparative example cut into 125 mm in length and 25 mm in width was attached to a test plate made of stainless steel material, and the electromagnetic shield film was cut in a 180° direction from the test plate using a tensile tester. The adhesion was evaluated by measuring the tensile force when peeled off. The results are shown in Tables 1 and 2. Note that if the tensile force when peeled off is 1 N/25 mm or more, it can be said that the adhesive force is sufficiently strong.
  • the storage modulus of the conductive adhesive at 65° C. is 1.6 ⁇ 10 4 Pa or more, and the parameters of the surface properties of the conductive adhesive are within the scope of the present invention. It was found that the electromagnetic shielding films according to each example had high creep resistance and high adhesiveness. On the other hand, the electromagnetic shielding film according to Comparative Example 1 in which the conductive adhesive had a storage modulus of less than 1.6 ⁇ 10 4 Pa at 65° C. was found to have low creep resistance. Furthermore, it was found that the electromagnetic shielding film according to Comparative Example 2, in which the parameters of the surface properties of the conductive adhesive were not included in the scope of the present invention, also had low creep resistance.
  • Conductive adhesive 11 First main surface 12 Second main surface 20 Shield layer 30 Protective layer 40 Electromagnetic shielding film 50 Printed wiring board 51 Base film 52 Printed circuit 52a Ground circuit 53 Coverlay 53a Opening 60 Shield printed wiring board

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Adhesives Or Adhesive Processes (AREA)

Abstract

Provided is an electroconductive adhesive which has both a high creep resistance at high temperatures and high adhesivity. This electroconductive adhesive is a sheet-type electroconductive adhesive comprising: electroconductive particles; a resin composition; a first main surface; and a second main surface opposing the first main surface. The conductive adhesive is characterized in that: the storage elastic modulus thereof at 65°C is 1.6×104Pa or more; and the arithmetic roughness Ra of the first main surface is 4 μm or less.

Description

導電性粘着剤及び電磁波シールドフィルムConductive adhesive and electromagnetic shielding film
本発明は、導電性粘着剤及び電磁波シールドフィルムに関する。 The present invention relates to a conductive adhesive and an electromagnetic shielding film.
従来から、プリント配線基板においては、導電性接着剤が多用されている。例えば、プリント配線基板に接着して使用される電磁波シールドフィルム（以下、単に「シールドフィルム」と称する場合がある）は、金属箔などのシールド層と当該シールド層の表面に設けられた導電性接着シートとを有する。導電性接着シートは、例えばシールド層の表面に導電性接着剤をシート状に塗工して形成され、シールド層をプリント配線基板の表面に接着すると共に、プリント配線基板のグランドパターンとシールド層とを導通させる機能を有する。 Conventionally, conductive adhesives have been widely used in printed wiring boards. For example, an electromagnetic shielding film (hereinafter sometimes simply referred to as a "shielding film") that is used by adhering to a printed wiring board consists of a shielding layer such as metal foil and a conductive adhesive provided on the surface of the shielding layer. It has a sheet. The conductive adhesive sheet is formed, for example, by applying a conductive adhesive in sheet form to the surface of the shield layer, and it adheres the shield layer to the surface of the printed wiring board, and also connects the ground pattern of the printed wiring board and the shield layer. It has the function of conducting.
このような導電性接着剤として、特許文献１には、貯蔵弾性率のピークトップ温度が１２０℃以下であり、貼付面の平均算術表面粗さＲａが０．１μｍ以上である導電性接着シートが開示されている。 As such a conductive adhesive, Patent Document 1 discloses a conductive adhesive sheet having a storage modulus peak top temperature of 120° C. or less and an average arithmetic surface roughness Ra of the application surface of 0.1 μm or more. Disclosed.
特許文献１に記載の導電性接着シートは、シールド層となる金属層が積層され、プリント配線板に配置される。この際、導電性接着シートとシールド層との積層体は、プリント配線板とをラミネート等により仮止めされ、その後、高温で加熱・加圧されることにより、導電性接着シートが硬化する。これにより導電性接着シートとシールド層との積層体が、プリント配線板に固定される。
このように仮止めを行う場合、仮止め時において接着強度が弱いと、本硬化工程までの間に、導電性接着シートとシールド層との積層体が、プリント配線基板に対して位置ズレしたり、プリント配線基板から脱落することがある。
特許文献１に記載の導電性接着シートでは、貯蔵弾性率のピークトップ温度及び貼付面の平均算術表面粗さを所定の値にすることで、上記問題が生じることを防いでいる。 In the conductive adhesive sheet described in Patent Document 1, a metal layer serving as a shield layer is laminated and placed on a printed wiring board. At this time, the laminate of the conductive adhesive sheet and the shield layer is temporarily attached to the printed wiring board by laminating or the like, and then heated and pressurized at high temperature to harden the conductive adhesive sheet. This fixes the laminate of the conductive adhesive sheet and the shield layer to the printed wiring board.
When temporary bonding is performed in this way, if the adhesive strength is weak during temporary bonding, the laminate of the conductive adhesive sheet and shield layer may become misaligned with respect to the printed wiring board before the main curing process. , it may fall off the printed wiring board.
In the conductive adhesive sheet described in Patent Document 1, the above problem is prevented by setting the peak top temperature of the storage elastic modulus and the average arithmetic surface roughness of the attachment surface to predetermined values.
国際公開第２０２０－０８５３１６号International Publication No. 2020-085316
特許文献１には、導電性接着シートのバインダー成分として熱硬化性樹脂を用いたものが開示されている。
近年、高温・高圧条件下ではなく、比較的緩やかな条件でプリント配線板に接着することができる導電性粘着シートが求められる傾向がある。すなわち、バインダー成分として粘着性樹脂を用いたものが求められる傾向がある。 Patent Document 1 discloses a conductive adhesive sheet using a thermosetting resin as a binder component.
In recent years, there has been a trend for conductive adhesive sheets that can be bonded to printed wiring boards under relatively mild conditions rather than under high temperature and high pressure conditions. That is, there is a tendency to require a adhesive resin as a binder component.
バインダーとして熱硬化性樹脂を用いる場合、熱硬化性樹脂は熱により硬化するので、耐クリープ性が高いという特徴がある。
しかし、バインダー成分として粘着性樹脂を用いる場合、粘着性樹脂は熱硬化性樹脂のように硬化しないので、耐クリープ性が低いという問題がある。
粘着性樹脂を備える電磁波シールドフィルムは、ＦＦＣやプリント配線板上の可動部や屈曲部に使用されることがある。このような場所に配置された電磁波シールドフィルムには、引張応力が加わりやすくなる。また、電磁波シールドフィルムが熱源に近い場所に配置される場合、熱を受けやすくなる。このような場所に電磁波シールドフィルムが配置されると、特に耐クリープ性が問題となる。
また、バインダー成分として粘着性樹脂を用いる場合に、耐クリープ性を向上させる方法として変形しにくい材料を用いる方法が考えられるが、変形しにくい材料を用いると粘着力が低下してしまうという問題がある。
すなわち、耐クリープ性の向上と、粘着性の向上とはトレードオフの関係にあり、これらを両立することは難しかった。 When a thermosetting resin is used as a binder, the thermosetting resin is cured by heat, so it has a characteristic of high creep resistance.
However, when an adhesive resin is used as a binder component, there is a problem that creep resistance is low because the adhesive resin does not harden like a thermosetting resin.
Electromagnetic shielding films containing adhesive resin are sometimes used for movable parts and bent parts on FFCs and printed wiring boards. Tensile stress is likely to be applied to the electromagnetic shielding film placed in such a location. Furthermore, when the electromagnetic shielding film is placed close to a heat source, it becomes susceptible to heat. When an electromagnetic shielding film is placed in such a location, creep resistance becomes a particular problem.
In addition, when using adhesive resin as a binder component, one possible method to improve creep resistance is to use a material that is difficult to deform, but there is a problem that using a material that is difficult to deform reduces adhesive strength. be.
That is, there is a trade-off relationship between improving creep resistance and improving adhesiveness, and it has been difficult to achieve both.
本発明は、上記問題を解決するためになされた発明であり、本発明の目的は、高温での耐クリープ性が高く、かつ、粘着性が高く、これらが両立している導電性粘着剤を提供することである。 The present invention was made to solve the above problems, and an object of the present invention is to provide a conductive adhesive that has both high creep resistance and high adhesiveness at high temperatures. It is to provide.
本発明者らは、導電性粘着剤の貯蔵弾性率を所定の値とし、導電性粘着剤の粘着面を所定の状態にすることで、導電性粘着剤の耐クリープ性が高くなり、かつ、粘着性も高くなることを見出し、本発明を完成させた。 The present inventors have found that by setting the storage modulus of the conductive adhesive to a predetermined value and setting the adhesive surface of the conductive adhesive to a predetermined state, the creep resistance of the conductive adhesive is increased, and It was discovered that the adhesiveness also increased, and the present invention was completed.
すなわち、本発明の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の算術平均粗さＲａが４μｍ以下であることを特徴とする。 That is, the conductive adhesive of the present invention is a sheet-shaped conductive adhesive that includes conductive particles and a resin composition, and has a first main surface and a second main surface opposite to the first main surface. The electrically conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and an arithmetic mean roughness Ra of the first principal surface is 4 μm or less.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大高さＲｚが１６μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and a maximum height Rz of the first principal surface is 16 μm or less. .
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大山高さＲｐが９．５μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the maximum peak height Rp of the first principal surface is 9.5 μm or less. shall be.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大谷深さＲｖが９μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and a maximum valley depth Rv of the first principal surface is 9 μm or less. do.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の平均高さＲｃが１１μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the average height Rc of the first principal surface is 11 μm or less. .
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大断面高さＲｔが１６μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the maximum cross-sectional height Rt of the first principal surface is 16 μm or less. do.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の二乗平均平方根高さＲｑが５μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the root mean square height Rq of the first principal surface is 5 μm or less. shall be.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の十点平均粗さＲｚＪＩＳが１４μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the ten-point average roughness RzJIS of the first principal surface is 14 μm or less. shall be.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面のコア部のレベル差Ｒｋが７μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the level difference Rk of the core portion of the first principal surface is 7 μm or less. shall be.
本発明の別の態様の導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の要素の平均長さＲｄｃが７μｍ以下であることを特徴とする。 A conductive adhesive according to another aspect of the present invention is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The adhesive is characterized in that the storage elastic modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the average length Rdc of the elements on the first principal surface is 7 μm or less. shall be.
上記本発明の導電性粘着剤では、６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であることが共通している。
そのため、導電性粘着剤の６５℃における貯蔵弾性率が上記範囲であると、導電性粘着剤は変形しにくくなり、高温での耐クリープ性が高くなる。 The electrically conductive adhesive of the present invention has in common that the storage modulus at 65° C. is 1.6×10 4 Pa or more.
Therefore, when the storage modulus of the conductive adhesive at 65° C. is within the above range, the conductive adhesive becomes difficult to deform and has high creep resistance at high temperatures.
上記本発明の導電性粘着剤では、第１主面の表面性状のパラメータ（Ｒａ、Ｒｚ、Ｒｐ、Ｒｖ、Ｒｃ、Ｒｔ、Ｒｑ、ＲｚＪＩＳ、Ｒｋ、Ｒｄｃ）が所定の範囲である。
これらのパラメータが上記の範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、上記本発明の導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In the conductive adhesive of the present invention, the surface quality parameters (Ra, Rz, Rp, Rv, Rc, Rt, Rq, RzJIS, Rk, Rdc) of the first main surface are within predetermined ranges.
The fact that these parameters are within the above ranges means that the first principal surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive pressure-sensitive adhesive of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
本発明の導電性粘着剤は、その用途に応じて、等方導電性又は異方導電性を有していてもよい。 The conductive adhesive of the present invention may have isotropic conductivity or anisotropic conductivity depending on its use.
本発明の電磁波シールドフィルムは、上記本発明の導電性粘着剤と、上記導電性粘着剤の第２主面に接するように積層されたシールド層とを備えることを特徴とする。 The electromagnetic shielding film of the present invention is characterized by comprising the conductive adhesive of the present invention and a shield layer laminated so as to be in contact with the second main surface of the conductive adhesive.
上記の通り、本発明の導電性粘着剤は、高温での耐クリープ性が高く、かつ、粘着性が高い。そのため、シールド層を被着体に確実に接着することができる。 As described above, the conductive adhesive of the present invention has high creep resistance and high adhesiveness at high temperatures. Therefore, the shield layer can be reliably bonded to the adherend.
本発明の電磁波シールドフィルムは、上記シールド層の上に形成された保護層をさらに備えることが好ましい。
保護層が形成されていることにより、シールド層及び導電性粘着剤を保護することができる。 The electromagnetic shielding film of the present invention preferably further includes a protective layer formed on the shielding layer.
By forming the protective layer, the shield layer and the conductive adhesive can be protected.
本発明によれば、高温での耐クリープ性が高く、かつ、粘着性が高く、これらが両立している導電性粘着剤を提供することができる。 According to the present invention, it is possible to provide a conductive adhesive that has both high creep resistance and high adhesiveness at high temperatures.
図１は、本発明の第１実施形態に係る導電性粘着剤の一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing an example of a conductive adhesive according to a first embodiment of the present invention. 図２は、本発明の第１実施形態に係る電磁波シールドフィルムの一例を模式的に示す断面図である。FIG. 2 is a cross-sectional view schematically showing an example of the electromagnetic shielding film according to the first embodiment of the present invention. 図３は、本発明の第１実施形態に係る電磁波シールドフィルムを備えるシールドプリント配線板の一例を模式的に示す断面図である。FIG. 3 is a cross-sectional view schematically showing an example of a shield printed wiring board including an electromagnetic shielding film according to the first embodiment of the present invention.
以下、本発明の導電性粘着剤について具体的に説明する。しかしながら、本発明は、以下の実施形態に限定されるものではなく、本発明の要旨を変更しない範囲において適宜変更して適用することができる。 Hereinafter, the conductive adhesive of the present invention will be specifically explained. However, the present invention is not limited to the following embodiments, and can be modified and applied as appropriate without changing the gist of the present invention.
（第１実施形態）
本発明の第１実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、第１主面の算術平均粗さＲａが４μｍ以下であることが必須の構成要件である。
この構成要件さえ満たせば、発明の効果を奏する範囲において適宜変更して適用することができる。 (First embodiment)
The conductive adhesive according to the first embodiment of the present invention is made of conductive particles and a resin composition, and has a first main surface and a second main surface opposite to the first main surface. The conductive adhesive must have a storage modulus of 1.6×10 4 Pa or more at 65°C and an arithmetic mean roughness Ra of the first principal surface of 4 μm or less. This is a configuration requirement.
As long as these constituent requirements are satisfied, the present invention can be modified and applied as appropriate within the scope of producing the effects of the invention.
図１は、本発明の第１実施形態に係る導電性粘着剤の一例を模式的に示す断面図である。
図１に示す導電性粘着剤１０は、導電性粒子と樹脂組成物とからなる。
また、導電性粘着剤１０は、シート状であり、第１主面１１と、第１主面１１に対向する第２主面１２を有する。 FIG. 1 is a cross-sectional view schematically showing an example of a conductive adhesive according to a first embodiment of the present invention.
The conductive adhesive 10 shown in FIG. 1 consists of conductive particles and a resin composition.
Further, the conductive adhesive 10 is in the form of a sheet, and has a first main surface 11 and a second main surface 12 opposite to the first main surface 11.
導電性粘着剤１０は、６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上である。
なお、当該貯蔵弾性率は、１．６×１０４～１．０×１０５Ｐａ以下であることが好ましく、１．６×１０４Ｐａ～９．０×１０４Ｐａであることがより好ましい。
６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であると、導電性粘着剤は変形しにくくなり、高温での耐クリープ性が高くなる。 The conductive adhesive 10 has a storage modulus of 1.6×10 4 Pa or more at 65° C.
Note that the storage elastic modulus is preferably 1.6×10 4 to 1.0×10 5 Pa or less, more preferably 1.6×10 4 Pa to 9.0×10 4 Pa. .
When the storage modulus at 65° C. is 1.6×10 4 Pa or more, the conductive adhesive becomes difficult to deform and has high creep resistance at high temperatures.
なお、「６５℃における貯蔵弾性率」は、動的粘弾性測定装置（レオメーター）によって測定することができる。 Note that the "storage modulus at 65°C" can be measured with a dynamic viscoelasticity measuring device (rheometer).
導電性粘着剤１０の６５℃における貯蔵弾性率は、導電性粘着剤１０に含まれる樹脂組成物の種類や含有量を調整したり、添加物を加えることにより制御することができる。 The storage modulus of the conductive adhesive 10 at 65° C. can be controlled by adjusting the type and content of the resin composition contained in the conductive adhesive 10 or by adding additives.
導電性粘着剤１０では、第１主面１１算術平均粗さＲａが４μｍ以下である。
なお、当該算術平均粗さＲａは、３．９７μｍ以下であることが好ましく、３．６５μｍ以下であることがより好ましい。
導電性粘着剤１０では、第１主面１１の算術平均粗さＲａが４μｍ以下であるので、第１主面１１が平坦に近いと言える。
そのため、第１主面１１に被着体を接触させると、第１主面１１と被着体とが密着しやすくなる。そのため、導電性粘着剤１０の第１主面１１における粘着力が高くなる。 In the conductive adhesive 10, the arithmetic mean roughness Ra of the first main surface 11 is 4 μm or less.
Note that the arithmetic mean roughness Ra is preferably 3.97 μm or less, more preferably 3.65 μm or less.
In the conductive adhesive 10, since the arithmetic mean roughness Ra of the first main surface 11 is 4 μm or less, it can be said that the first main surface 11 is nearly flat.
Therefore, when an adherend is brought into contact with the first main surface 11, the first main surface 11 and the adherend are likely to come into close contact with each other. Therefore, the adhesive force on the first main surface 11 of the conductive adhesive 10 becomes high.
また、第１主面１１の最大高さＲｚが１６μｍ以下であることが好ましく、１５．５μｍ以下であることがより好ましく、１５μｍ以下であることがさらに好ましい。
また、第１主面１１の最大山高さＲｐが９．５μｍ以下であることが好ましく、８．６μｍ以下であることがより好ましく、７．５μｍ以下であることがさらに好ましい。
また、第１主面１１の最大谷深さＲｖが９μｍ以下であることが好ましく、８．８μｍ以下であることがより好ましく、７μｍ以下であることがさらに好ましい。
また、第１主面１１の平均高さＲｃが１１μｍ以下であることが好ましく、１０．６μｍ以下であることがより好ましく、１０．３μｍ以下であることがさらに好ましい。
また、第１主面１１の最大断面高さＲｔが１６μｍ以下であることが好ましく、１５．５μｍ以下であることがより好ましく、１５μｍ以下であることがさらに好ましい。
また、第１主面１１の二乗平均平方根高さＲｑが５μｍ以下であることが好ましく、４．５μｍ以下であることがより好ましく、４．１μｍ以下であることがさらに好ましい。
また、第１主面１１の十点平均粗さＲｚＪＩＳが１４μｍ以下であることが好ましく、１３．５μｍ以下であることがより好ましく、１３．３μｍ以下であることがさらに好ましい。
また、第１主面１１のコア部のレベル差Ｒｋが７μｍ以下であることが好ましく、６．８μｍ以下であることがより好ましく、６．５μｍ以下であることがさらに好ましい。
また、第１主面１１の要素の平均長さＲｄｃが７μｍ以下であることが好ましく、６．６μｍ以下であることがより好ましく、６．３μｍ以下であることがさらに好ましい。
第１主面１１の表面性状のパラメータが上記範囲内であることは、第１主面１１が平坦に近いことを意味する。
そのため、上記表面性状のパラメータを有する第１主面１１に被着体を接触させると、第１主面１１と被着体とが密着しやすくなる。そのため、導電性粘着剤１０の第１主面１１における粘着力が高くなる。 Further, the maximum height Rz of the first main surface 11 is preferably 16 μm or less, more preferably 15.5 μm or less, and even more preferably 15 μm or less.
Further, the maximum peak height Rp of the first main surface 11 is preferably 9.5 μm or less, more preferably 8.6 μm or less, and even more preferably 7.5 μm or less.
Further, the maximum valley depth Rv of the first main surface 11 is preferably 9 μm or less, more preferably 8.8 μm or less, and even more preferably 7 μm or less.
Further, the average height Rc of the first main surface 11 is preferably 11 μm or less, more preferably 10.6 μm or less, and even more preferably 10.3 μm or less.
Further, the maximum cross-sectional height Rt of the first main surface 11 is preferably 16 μm or less, more preferably 15.5 μm or less, and even more preferably 15 μm or less.
Further, the root mean square height Rq of the first principal surface 11 is preferably 5 μm or less, more preferably 4.5 μm or less, and even more preferably 4.1 μm or less.
Further, the ten-point average roughness RzJIS of the first main surface 11 is preferably 14 μm or less, more preferably 13.5 μm or less, and even more preferably 13.3 μm or less.
Further, the level difference Rk of the core portion of the first main surface 11 is preferably 7 μm or less, more preferably 6.8 μm or less, and even more preferably 6.5 μm or less.
Further, the average length Rdc of the elements of the first main surface 11 is preferably 7 μm or less, more preferably 6.6 μm or less, and even more preferably 6.3 μm or less.
The fact that the surface quality parameters of the first main surface 11 are within the above range means that the first main surface 11 is nearly flat.
Therefore, when an adherend is brought into contact with the first main surface 11 having the above-mentioned surface quality parameters, the first main surface 11 and the adherend are likely to come into close contact with each other. Therefore, the adhesive force on the first main surface 11 of the conductive adhesive 10 becomes high.
一般的に、導電性粘着剤の貯蔵弾性率が高いと、耐クリープ性が高くなる反面、粘着性が低くなりやすい。
しかし、導電性粘着剤１０では、第１主面１１の算術平均粗さＲａが４μｍ以下なので、６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であったとしても、充分な粘着性を示す。
すなわち、導電性粘着剤１０は、高温での耐クリープ性が高く、かつ、粘着性が高く、これらが両立していると言える。 Generally, when a conductive adhesive has a high storage modulus, its creep resistance increases, but its tackiness tends to decrease.
However, in the conductive adhesive 10, the arithmetic mean roughness Ra of the first principal surface 11 is 4 μm or less, so even if the storage modulus at 65° C. is 1.6×10 4 Pa or more, sufficient adhesiveness is not achieved. shows.
That is, it can be said that the conductive adhesive 10 has high creep resistance at high temperatures and high adhesiveness, which are both compatible.
なお、導電性粘着剤１０では、第２主面１２の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。
また、第２主面１２の最大高さＲｚが１６μｍ以下であることが好ましく、１５．５μｍ以下であることがより好ましく、１５μｍ以下であることがさらに好ましい。
また、第２主面１２の最大山高さＲｐが９．５μｍ以下であることが好ましく、８．６μｍ以下であることがより好ましく、７．５μｍ以下であることがさらに好ましい。
また、第２主面１２の最大谷深さＲｖが９μｍ以下であることが好ましく、８．８μｍ以下であることがより好ましく、７μｍ以下であることがさらに好ましい。
また、第２主面１２の平均高さＲｃが１１μｍ以下であることが好ましく、１０．６μｍ以下であることがより好ましく、１０．３μｍ以下であることがさらに好ましい。
また、第２主面１２の最大断面高さＲｔが１６μｍ以下であることが好ましく、１５．５μｍ以下であることがより好ましく、１５μｍ以下であることがさらに好ましい。
また、第２主面１２の二乗平均平方根高さＲｑが５μｍ以下であることが好ましく、４．５μｍ以下であることがより好ましく、４．１μｍ以下であることがさらに好ましい。
また、第２主面１２の十点平均粗さＲｚＪＩＳが１４μｍ以下であることが好ましく、１３．５μｍ以下であることがより好ましく、１３．３μｍ以下であることがさらに好ましい。
また、第２主面１２のコア部のレベル差Ｒｋが７μｍ以下であることが好ましく、６．８μｍ以下であることがより好ましく、６．５μｍ以下であることがさらに好ましい。
また、第２主面１２の要素の平均長さＲｄｃが７μｍ以下であることが好ましく、６．６μｍ以下であることがより好ましく、６．３μｍ以下であることがさらに好ましい。
第２主面１２の表面性状のパラメータが上記範囲内であると、第２主面１２の粘着力が高くなる。 In addition, in the conductive adhesive 10, the arithmetic mean roughness Ra of the second main surface 12 is preferably 4 μm or less, more preferably 3.97 μm or less, and even more preferably 3.65 μm or less. .
Further, the maximum height Rz of the second main surface 12 is preferably 16 μm or less, more preferably 15.5 μm or less, and even more preferably 15 μm or less.
Further, the maximum peak height Rp of the second main surface 12 is preferably 9.5 μm or less, more preferably 8.6 μm or less, and even more preferably 7.5 μm or less.
Further, the maximum valley depth Rv of the second main surface 12 is preferably 9 μm or less, more preferably 8.8 μm or less, and even more preferably 7 μm or less.
Further, the average height Rc of the second main surface 12 is preferably 11 μm or less, more preferably 10.6 μm or less, and even more preferably 10.3 μm or less.
Further, the maximum cross-sectional height Rt of the second main surface 12 is preferably 16 μm or less, more preferably 15.5 μm or less, and even more preferably 15 μm or less.
Further, the root mean square height Rq of the second principal surface 12 is preferably 5 μm or less, more preferably 4.5 μm or less, and even more preferably 4.1 μm or less.
Further, the ten-point average roughness RzJIS of the second main surface 12 is preferably 14 μm or less, more preferably 13.5 μm or less, and even more preferably 13.3 μm or less.
Further, the level difference Rk of the core portion of the second main surface 12 is preferably 7 μm or less, more preferably 6.8 μm or less, and even more preferably 6.5 μm or less.
Further, the average length Rdc of the elements of the second main surface 12 is preferably 7 μm or less, more preferably 6.6 μm or less, and even more preferably 6.3 μm or less.
When the parameters of the surface properties of the second main surface 12 are within the above range, the adhesive force of the second main surface 12 becomes high.
なお、本明細書において、導電性粘着剤の表面性状のパラメータのうち、Ｒａ、Ｒｚ、Ｒｐ、Ｒｖ、Ｒｃ、Ｒｔ、Ｒｑ、ＲｚＪＩＳ及びＲｄｃは、ＪＩＳ　Ｂ　０６０１：２０１３で定められるパラメータであり、Ｒｋは、ＪＩＳ　Ｂ０６７１－２：２００２で定められるパラメータであり、コンフォーカル顕微鏡（Ｌａｓｅｒｔｅｃ社製、ＯＰＴＥＬＩＣＳ　ＨＹＢＲＩＤ）等の表面形状測定機に付随する解析ソフトウェアを用いて測定することができる。 In addition, in this specification, among the parameters of the surface properties of the conductive adhesive, Ra, Rz, Rp, Rv, Rc, Rt, Rq, RzJIS and Rdc are parameters defined in JIS B 0601:2013, Rk is a parameter defined in JIS B0671-2:2002, and can be measured using analysis software attached to a surface shape measuring device such as a confocal microscope (OPTELICS HYBRID, manufactured by Lasertec).
詳しくは後述するが、導電性粘着剤１０において、第１主面１１の算術平均粗さＲａ等の表面性状は、導電性粒子の含有量や、大きさ、形状等を調整することにより制御することができる。 As will be described in detail later, in the conductive adhesive 10, the surface properties such as the arithmetic mean roughness Ra of the first main surface 11 are controlled by adjusting the content, size, shape, etc. of the conductive particles. be able to.
導電性粘着剤１０は、その用途に応じて、等方導電性又は異方導電性を有していてもよい。
詳しくは後述するが、導電性粘着剤１０に含まれる導電性粒子の大きさや、含有量等を調整することにより、導電性粘着剤１０を、等方導電性を有する導電性粘着剤にしたり、異方導電性を有する導電性粘着剤にすることができる。 The conductive adhesive 10 may have isotropic conductivity or anisotropic conductivity depending on its use.
As will be described in detail later, by adjusting the size, content, etc. of the conductive particles contained in the conductive adhesive 10, the conductive adhesive 10 can be made into a conductive adhesive having isotropic conductivity. It can be made into a conductive adhesive having anisotropic conductivity.
導電性粘着剤１０の厚さは、用途に応じて適宜決定することが好ましいが、耐クリープ性及び粘着性の観点から、３～１００μｍであることが好ましく、５～５０μｍであることがより好ましい。 The thickness of the conductive adhesive 10 is preferably determined appropriately depending on the application, but from the viewpoint of creep resistance and adhesiveness, it is preferably 3 to 100 μm, more preferably 5 to 50 μm. .
以下、本発明の導電性粘着剤の各構成について詳述する。 Hereinafter, each structure of the conductive adhesive of the present invention will be explained in detail.
（導電性粒子）
導電性粒子は、特に限定されないが、例えば、金属粒子、金属コート樹脂粒子、カーボンフィラーなどが挙げられる。 (conductive particles)
The conductive particles are not particularly limited, and examples thereof include metal particles, metal-coated resin particles, carbon filler, and the like.
金属粒子及び金属コート樹脂粒子の被覆部を構成する金属としては、例えば、金、銀、銅、ニッケル、亜鉛などが挙げられる。上記金属は一種のみを使用してもよいし、二種以上を使用してもよい。 Examples of the metal constituting the coating portion of the metal particles and metal-coated resin particles include gold, silver, copper, nickel, and zinc. The above metals may be used alone or in combination of two or more.
金属粒子としては、具体的には、例えば、銅粒子、銀粒子、ニッケル粒子、銀コート銅粒子、金コート銅粒子、銀コートニッケル粒子、金コートニッケル粒子、銀コート合金粒子などが挙げられる。
銀コート合金粒子としては、例えば、銅を含む合金粒子（例えば、銅とニッケルと亜鉛との合金からなる銅合金粒子）が銀により被覆された銀コート銅合金粒子などが挙げられる。
金属粒子は、電解法、アトマイズ法、還元法などにより作製することができる。 Specific examples of the metal particles include copper particles, silver particles, nickel particles, silver-coated copper particles, gold-coated copper particles, silver-coated nickel particles, gold-coated nickel particles, and silver-coated alloy particles.
Examples of the silver-coated alloy particles include silver-coated copper alloy particles in which alloy particles containing copper (for example, copper alloy particles made of an alloy of copper, nickel, and zinc) are coated with silver.
Metal particles can be produced by an electrolysis method, an atomization method, a reduction method, or the like.
金属粒子としては、中でも、銀粒子、銀コート銅粒子、銀コート銅合金粒子が好ましい。導電性に優れ、金属粒子の酸化及び凝集を抑制し、かつ、金属粒子のコストを下げることができる観点から、特に、銀コート銅粒子、銀コート銅合金粒子が好ましい。 Among the metal particles, silver particles, silver-coated copper particles, and silver-coated copper alloy particles are preferable. Silver-coated copper particles and silver-coated copper alloy particles are particularly preferred from the viewpoints of excellent conductivity, suppressing oxidation and aggregation of metal particles, and lowering the cost of metal particles.
導電性粘着剤１０の第１主面１１において、導電性粒子の一部は露出する。そのため、導電性粒子の含有量、大きさ、形状等は、第１主面１１の算術平均粗さＲａに影響する。
導電性粒子の含有量、大きさ、形状等を調整することにより、第１主面１１の算術平均粗さＲａを４μｍ以下にすることができる。 A portion of the conductive particles are exposed on the first main surface 11 of the conductive adhesive 10. Therefore, the content, size, shape, etc. of the conductive particles affect the arithmetic mean roughness Ra of the first main surface 11.
By adjusting the content, size, shape, etc. of the conductive particles, the arithmetic mean roughness Ra of the first main surface 11 can be set to 4 μm or less.
導電性粘着剤の第１主面の算術平均粗さＲａが４μｍ以下にするという観点から、導電性粒子の含有量は、例えば、５～８５重量％であることが好ましく、５～７０重量％であることがより好ましい。 From the viewpoint of making the arithmetic mean roughness Ra of the first main surface of the conductive adhesive 4 μm or less, the content of the conductive particles is preferably 5 to 85% by weight, and 5 to 70% by weight, for example. It is more preferable that
また、導電性粘着剤の第１主面の算術平均粗さＲａが４μｍ以下にするという観点から、導電性粒子のメディアン径（Ｄ５０）は、３～１００μｍであることが好ましく、５～５０μｍであることがより好ましい。 Furthermore, from the viewpoint of setting the arithmetic mean roughness Ra of the first principal surface of the conductive adhesive to 4 μm or less, the median diameter (D 50 ) of the conductive particles is preferably 3 to 100 μm, and preferably 5 to 50 μm. It is more preferable that
なお、本明細書において、導電性粒子のメディアン径（Ｄ５０）は、レーザー回折・散乱法により求めた粒度分布における積算値５０％での粒径を意味する。 Note that in this specification, the median diameter (D 50 ) of conductive particles means the particle diameter at 50% of the integrated value in the particle size distribution determined by laser diffraction/scattering method.
導電性粒子の形状としては、特に限定されず、球状（真球状、楕球状等）、フレーク状（鱗片状、扁平状等）、樹枝状（デンドライト状）、繊維状、フィラメント状、不定形（多面体）であってもよい。これらの中では、導電性粘着剤の導電性を向上させ、導電性粘着剤の第１主面を平坦にするという観点から、球状、フレーク状、デンドライト状、フィラメント状であることが好ましい。 The shape of the conductive particles is not particularly limited, and may be spherical (true sphere, ellipsoid, etc.), flake (scaly, flat, etc.), dendritic (dendritic), fibrous, filamentary, amorphous ( polyhedron). Among these, from the viewpoint of improving the conductivity of the conductive adhesive and flattening the first main surface of the conductive adhesive, spherical, flake, dendrite, and filament shapes are preferable.
なお、導電性粒子の含有量、大きさ、形状は、導電性粘着剤が等方導電性を有するかや、異方導電性を有するかにも影響する。
例えば、導電性粘着剤に等方導電性を付与する場合、導電性粒子の含有量を５０～８５重量％とする方法が挙げられる。また、導電性粘着剤に異方導電性を付与する場合、導電性粒子の含有量を５重量％以上、４９重量％未満とする方法が挙げられる。 Note that the content, size, and shape of the conductive particles also affect whether the conductive adhesive has isotropic conductivity or anisotropic conductivity.
For example, when imparting isotropic conductivity to a conductive adhesive, a method may be used in which the content of conductive particles is adjusted to 50 to 85% by weight. Further, when imparting anisotropic conductivity to the conductive adhesive, a method may be mentioned in which the content of conductive particles is set to 5% by weight or more and less than 49% by weight.
導電性粒子の含有量、大きさ、形状は、導電性粘着剤の用途や、所望の性能に応じ適宜決定することが好ましい。 The content, size, and shape of the conductive particles are preferably determined as appropriate depending on the use of the conductive adhesive and desired performance.
（樹脂組成物）
樹脂組成物としては、粘着性を有する樹脂組成物であれば特に限定されないが、天然ゴム、アクリル系樹脂、ポリウレタン系樹脂、シリコーン系樹脂及びポリエステル系樹脂からなる群から選択される少なくとも１種の樹脂を含むことが好ましい。
これらの中では、アクリル系樹脂及びシリコーン系樹脂がより好ましい。 (Resin composition)
The resin composition is not particularly limited as long as it has adhesive properties, but at least one resin selected from the group consisting of natural rubber, acrylic resin, polyurethane resin, silicone resin, and polyester resin. Preferably, it contains a resin.
Among these, acrylic resins and silicone resins are more preferred.
アクリル系樹脂は、ガラス転移温度（Ｔｇ）が０℃以下であることが好ましく、－５℃以下であることがより好ましく、－１０℃以下であることがさらに好ましい。
アクリル系樹脂のガラス転移温度が０℃を超えると、弱い圧力及び温度条件で被着体に貼着した際の、粘着力が低くなる。
なお、アクリル系樹脂のガラス転移温度は、示差走査熱量分析により求められる。 The acrylic resin preferably has a glass transition temperature (Tg) of 0°C or lower, more preferably -5°C or lower, and even more preferably -10°C or lower.
If the glass transition temperature of the acrylic resin exceeds 0° C., the adhesive strength will be low when attached to an adherend under low pressure and temperature conditions.
Note that the glass transition temperature of the acrylic resin is determined by differential scanning calorimetry.
アクリル系樹脂の酸価は、特に限定されないが、５ｍｇＫＯＨ／ｇ以下が好ましく、１～５ｍｇＫＯＨ／ｇであることがより好ましく、１～３ｍｇＫＯＨ／ｇであることがさらに好ましい。
アクリル系樹脂の酸価が５ｍｇＫＯＨ／ｇ以下であると、硬化剤によるアクリル系樹脂の硬化が過剰に進行することが無いため、簡易に被着体に接着でき、被着体に対する粘着力が向上する。 The acid value of the acrylic resin is not particularly limited, but is preferably 5 mgKOH/g or less, more preferably 1 to 5 mgKOH/g, and even more preferably 1 to 3 mgKOH/g.
When the acid value of the acrylic resin is 5 mgKOH/g or less, the curing of the acrylic resin by the curing agent will not proceed excessively, so it can be easily adhered to the adherend, and the adhesive strength to the adherend is improved. do.
アクリル系樹脂の重量平均分子量は、特に限定されないが、１０万～１００万が好ましく、２０万～６０万であることがより好ましい。上記重量平均分子量が上記範囲内であると、被着体に対する粘着力が向上する。
アクリル系樹脂の重量平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により、標準物質としてポリスチレンを用いて測定することができる。 The weight average molecular weight of the acrylic resin is not particularly limited, but is preferably from 100,000 to 1,000,000, more preferably from 200,000 to 600,000. When the weight average molecular weight is within the above range, the adhesive strength to an adherend is improved.
The weight average molecular weight of the acrylic resin can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.
本明細書において、「アクリル系樹脂」は、（メタ）アクリレート化合物を単量体成分として構成された重合体、すなわち、（メタ）アクリレート化合物に由来する構成単位を有する重合体（又は共重合体）であることを意味する。
なお、本明細書において、「（メタ）アクリレート」とは、アクリレート及び／又はメタクリレートを意味する。そして「（メタ）アクリレート化合物」とは、アクリロイル基及び／又はメタクリロイル基を有する化合物を示す。「（メタ）アクリル」についても同様である。
アクリル系樹脂は、（メタ）アクリレート化合物は、一種のみからなっていてもよく、二種以上からなっていてもよい。 In the present specification, "acrylic resin" refers to a polymer composed of a (meth)acrylate compound as a monomer component, that is, a polymer (or copolymer) having a structural unit derived from a (meth)acrylate compound. ).
In addition, in this specification, "(meth)acrylate" means acrylate and/or methacrylate. The term "(meth)acrylate compound" refers to a compound having an acryloyl group and/or a methacryloyl group. The same applies to "(meth)acrylic".
The acrylic resin may consist of only one type of (meth)acrylate compound, or may consist of two or more types.
上記（メタ）アクリレート化合物としては、例えば、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｓ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸イソアミル、（メタ）アクリル酸オクチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸イソノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸ドデシル等の直鎖又は分岐鎖状のアルキル基を有する（メタ）アクリル酸アルキルエステル；（メタ）アクリル酸；カルボキシエチルアクリレート等のカルボキシル基含有（メタ）アクリル酸エステル；２－ヒドロキシメチル（メタ）アクリレート、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、６－ヒドロキシヘキシル（メタ）アクリレート、ジエチレングリコールモノ（メタ）アクリレート、ジプロピレングリコールモノ（メタ）アクリレート等のヒドロキシル基含有（メタ）アクリル酸エステル；（メタ）アクリル酸シクロヘキシル等の（メタ）アクリル酸シクロアルキルエステル；Ｎ－メチロール（メタ）アクリルアミド、Ｎ－ブトキシメチル（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド等の（メタ）アクリル酸アミド誘導体；ジメチルアミノエチル（メタ）アクリレート、ジエチルアミノエチル（メタ）アクリレート、ジプロピルアミノエチル（メタ）アクリレート、ジメチルアミノプロピル（メタ）アクリレート、ジプロピルアミノプロピル（メタ）アクリレート等の（メタ）アクリル酸ジアルキルアミノアルキルエステルなどが挙げられる。 Examples of the above (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, and (meth)acrylate. Isobutyl acid, s-butyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, isoamyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate , (meth)acrylic acid alkyl esters having a linear or branched alkyl group such as isononyl (meth)acrylate, decyl (meth)acrylate, and dodecyl (meth)acrylate; (meth)acrylic acid; carboxyethyl Carboxyl group-containing (meth)acrylic esters such as acrylate; 2-hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 6 - Hydroxyl group-containing (meth)acrylic esters such as hydroxyhexyl (meth)acrylate, diethylene glycol mono(meth)acrylate, and dipropylene glycol mono(meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate Ester; (meth)acrylic acid amide derivatives such as N-methylol (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide; dimethylamino (Meth)acrylic acid dialkylaminoalkyl esters such as ethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dipropylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dipropylaminopropyl (meth)acrylate, etc. can be mentioned.
また、上記（メタ）アクリレート化合物としては、ネオペンチルグリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ジトリメチロールプロパンテトラ（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート等の多官能（メタ）アクリレートも挙げられる。さらに、２－ヒドロキシ－３－アクリロイロキシプロピル（メタ）アクリレート、フェニルグリシジルエーテル（メタ）アクリレートヘキサメチレンジイソシアネートウレタンプレポリマー、ビスフェノールＡジグリシジルエーテルアクリル酸付加物なども挙げられる。 In addition, the above (meth)acrylate compounds include neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, ) Polyfunctional (meth)acrylates such as acrylates are also included. Further examples include 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, phenylglycidyl ether (meth)acrylate hexamethylene diisocyanate urethane prepolymer, and bisphenol A diglycidyl ether acrylic acid adduct.
上記アクリル系樹脂は、（メタ）アクリレート化合物以外の単量体成分由来の構成単位を有していてもよい。このような単量体成分としては、特に限定されないが、例えば、クロトン酸、イタコン酸、フマル酸、マレイン酸等のカルボキシル基含有重合性不飽和化合物又はその無水物；スチレン、ビニルトルエン、α－メチルスチレン等のスチレン系化合物；酢酸ビニル、プロピオン酸ビニル等のビニルエステル類；塩化ビニル等のハロゲン化ビニル；メチルビニルエーテル等のビニルエーテル類；（メタ）アクリロニトリル等のシアノ基含有ビニル化合物；エチレン、プロピレン等のα－オレフィンなどが挙げられる。 The acrylic resin may have a structural unit derived from a monomer component other than the (meth)acrylate compound. Such monomer components are not particularly limited, but include, for example, carboxyl group-containing polymerizable unsaturated compounds such as crotonic acid, itaconic acid, fumaric acid, and maleic acid, or their anhydrides; styrene, vinyltoluene, α- Styrenic compounds such as methylstyrene; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl halides such as vinyl chloride; Vinyl ethers such as methyl vinyl ether; Cyano group-containing vinyl compounds such as (meth)acrylonitrile; ethylene, propylene α-olefins such as
導電性粘着剤１０のうち、樹脂組成物の含有割合は、特に限定されないが、樹脂組成物中の固形分の総量１００重量％に対して、１５～９５重量％であることが好ましく、３０～９５重量％であることがより好ましく、３０～８５重量％であることがさらに好ましい。
上記含有割合が１５重量％未満であると、被着体に対する粘着力が低下する。
上記含有割合が９５重量％を超えると、相対的に導電性粒子の割合が少なくなり、電気的安定性が低下する。 The content of the resin composition in the conductive adhesive 10 is not particularly limited, but is preferably 15 to 95% by weight, and 30 to 95% by weight, based on 100% by weight of the total solid content in the resin composition. It is more preferably 95% by weight, and even more preferably 30 to 85% by weight.
If the content is less than 15% by weight, the adhesive strength to the adherend will decrease.
When the content exceeds 95% by weight, the proportion of conductive particles becomes relatively small, resulting in a decrease in electrical stability.
（その他の成分）
導電性粘着剤１０は、導電性粒子及び樹脂組成物以外に、必要に応じて、硬化剤、難燃剤、可塑剤、消泡剤、粘度調整剤、酸化防止剤、希釈剤、沈降防止剤、充填剤、着色剤、レベリング剤、カップリング剤、粘着性付与剤等を含んでいてもよい。 (Other ingredients)
In addition to the conductive particles and the resin composition, the conductive adhesive 10 may optionally contain a curing agent, a flame retardant, a plasticizer, an antifoaming agent, a viscosity modifier, an antioxidant, a diluent, an antisettling agent, It may also contain fillers, colorants, leveling agents, coupling agents, tackifiers, and the like.
硬化剤としては特に限定されないが、樹脂組成物がアクリル系樹脂である場合、イソシアネート系硬化剤を用いることができる。
イソシアネート系硬化剤は、分子内にイソシアネート基を２以上有する化合物であり、アクリル系樹脂の硬化を促進する。イソシアネート系硬化剤は、一種のみを使用してもよいし、二種以上を使用してもよい。 The curing agent is not particularly limited, but when the resin composition is an acrylic resin, an isocyanate curing agent can be used.
The isocyanate curing agent is a compound having two or more isocyanate groups in the molecule, and promotes curing of the acrylic resin. Only one type of isocyanate curing agent may be used, or two or more types may be used.
イソシアネート系硬化剤としては、例えば、１，２－エチレンジイソシアネート、１，４－ブチレンジイソシアネート、１，６－ヘキサメチレンジイソシアネート等の低級脂肪族ポリイソシアネート；シクロペンチレンジイソシアネート、シクロヘキシレンジイソシアネート、イソホロンジイソシアネート、水素添加トルエンジイソシアネート、水素添加キシレンジイソシアネート等の脂環族ポリイソシアネート；２，４－トルエンジイソシアネート、２，６－トルエンジイソシアネート、４，４’－ジフェニルメタンジイソシアネート、キシリレンジイソシアネート等の芳香族ポリイソシアネートなどが挙げられる。 Examples of the isocyanate curing agent include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, Alicyclic polyisocyanates such as hydrogenated toluene diisocyanate and hydrogenated xylylene diisocyanate; aromatic polyisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, etc. Can be mentioned.
イソシアネート系硬化剤の含有量は、アクリル系樹脂１００重量部に対して、０．０５～５．０重量部が好ましく、０．１～４．０重量部であることがより好ましく、１．０～３．５重量部であることがさらに好ましい。
イソシアネート系硬化剤の含有量が、０．０５重量部以上であることにより、アクリル系樹脂を適度に硬化することができ、導電性粘着剤１０の６５℃における貯蔵弾性率を１．６×１０４Ｐａ以上にしやすくなる。
イソシアネート系硬化剤の含有量が５．０重量部以下であると、硬化剤によりアクリル系樹脂が過剰に硬化することを抑制し粘着力が向上する。 The content of the isocyanate curing agent is preferably 0.05 to 5.0 parts by weight, more preferably 0.1 to 4.0 parts by weight, and 1.0 parts by weight based on 100 parts by weight of the acrylic resin. More preferably, the amount is 3.5 parts by weight.
When the content of the isocyanate curing agent is 0.05 parts by weight or more, the acrylic resin can be appropriately cured, and the storage modulus at 65° C. of the conductive adhesive 10 is 1.6×10 It becomes easier to increase the pressure to 4 Pa or higher.
When the content of the isocyanate curing agent is 5.0 parts by weight or less, the curing agent suppresses excessive curing of the acrylic resin and improves adhesive strength.
次に、本発明の導電性粘着剤を備える電磁波シールドフィルムについて説明する。
なお、本発明の導電性粘着剤を備える電磁波シールドフィルムは、本発明の一態様である。
図２は、本発明の第１実施形態に係る電磁波シールドフィルムの一例を模式的に示す断面図である。 Next, an electromagnetic shielding film including the conductive adhesive of the present invention will be explained.
Note that the electromagnetic shielding film including the conductive adhesive of the present invention is one embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing an example of the electromagnetic shielding film according to the first embodiment of the present invention.
図２に示す電磁波シールドフィルム４０は、導電性粘着剤１０と、導電性粘着剤１０の第２主面１２に接するように積層されたシールド層２０と、シールド層２０の上に形成された保護層３０を備える。
なお、電磁波シールドフィルム４０では、導電性粘着剤１０の第１主面１１が、被着体と接触する面になる。 The electromagnetic wave shielding film 40 shown in FIG. A layer 30 is provided.
Note that in the electromagnetic shielding film 40, the first main surface 11 of the conductive adhesive 10 is the surface that comes into contact with the adherend.
上記の通り、導電性粘着剤１０は、高温での耐クリープ性が高く、かつ、粘着性が高い。そのため、シールド層２０を被着体に確実に接着することができる。 As described above, the conductive adhesive 10 has high creep resistance and high adhesiveness at high temperatures. Therefore, the shield layer 20 can be reliably bonded to the adherend.
また、保護層３０が形成されていることにより、シールド層２０及び導電性粘着剤１０を保護することができる。 Further, by forming the protective layer 30, the shield layer 20 and the conductive adhesive 10 can be protected.
次に、電磁波シールドフィルム４０のシールド層２０及び保護層３０について説明する。 Next, the shield layer 20 and protective layer 30 of the electromagnetic shielding film 40 will be explained.
（シールド層）
シールド層２０としては、電磁波を反射、吸収することによりシールドすることができれば、その構成は特に限定されないが、例えば、金属層であることが好ましい。 (shield layer)
The structure of the shield layer 20 is not particularly limited as long as it can shield electromagnetic waves by reflecting or absorbing them, but it is preferably a metal layer, for example.
このような金属層を構成する金属としては、例えば、金、銀、銅、アルミニウム、ニッケル、スズ、パラジウム、クロム、チタン、亜鉛、又はこれらの合金などが挙げられる。これらの中では電磁波シールド効果により優れる観点から、銅層、銀層が好ましく、経済性の観点から、銅であることがより好ましい。 Examples of the metal constituting such a metal layer include gold, silver, copper, aluminum, nickel, tin, palladium, chromium, titanium, zinc, and alloys thereof. Among these, a copper layer and a silver layer are preferred from the viewpoint of superior electromagnetic shielding effect, and copper is more preferred from the viewpoint of economy.
金属層の材質及び厚さは、必要とする電磁波シールド効果及び繰り返し屈曲・摺動耐性に応じて適宜決定すればよい。
例えば、充分な電磁波シールド効果を得る観点から、金属層の厚さは０．１μｍ以上とすることが好ましい。
また、生産性及び屈曲性等の観点から１２μｍ以下とすることが好ましい。 The material and thickness of the metal layer may be appropriately determined depending on the required electromagnetic shielding effect and repeated bending/sliding resistance.
For example, from the viewpoint of obtaining a sufficient electromagnetic shielding effect, the thickness of the metal layer is preferably 0.1 μm or more.
Further, from the viewpoint of productivity, flexibility, etc., it is preferable that the thickness is 12 μm or less.
なお、金属層は、電解メッキ法、無電解メッキ法、スパッタリング法、電子ビーム蒸着法、真空蒸着法、ＣＶＤ法、メタルオーガニック等により形成することができる。また、金属層は、金属箔、金属ナノ粒子、鱗片状金属粒子等により形成することもできる。 Note that the metal layer can be formed by an electrolytic plating method, an electroless plating method, a sputtering method, an electron beam evaporation method, a vacuum evaporation method, a CVD method, a metal organic method, or the like. Moreover, the metal layer can also be formed from metal foil, metal nanoparticles, scaly metal particles, or the like.
（保護層）
保護層３０は、樹脂材料からなり、絶縁性を有し、所定の機械的強度、耐薬品性及び耐熱性を満たすことが好ましい。 (protective layer)
It is preferable that the protective layer 30 is made of a resin material, has insulation properties, and satisfies predetermined mechanical strength, chemical resistance, and heat resistance.
保護層３０を構成する樹脂材料は、充分な絶縁性を有していれば特に限定されないが、例えば熱可塑性樹脂組成物、熱硬化性樹脂組成物、及び、活性エネルギー線硬化性組成物等を用いることができる。 The resin material constituting the protective layer 30 is not particularly limited as long as it has sufficient insulation, but examples include thermoplastic resin compositions, thermosetting resin compositions, and active energy ray-curable compositions. Can be used.
熱可塑性樹脂組成物としては、特に限定されないが、スチレン系樹脂組成物、酢酸ビニル系樹脂組成物、ポリエステル系樹脂組成物、ポリエチレン系樹脂組成物、ポリプロピレン系樹脂組成物、イミド系樹脂組成物、及び、アクリル系樹脂組成物等を用いることができる。熱硬化性樹脂組成物としては、特に限定されないが、フェノール系樹脂組成物、エポキシ系樹脂組成物、ウレタン系樹脂組成物、メラミン系樹脂組成物、及び、アルキッド系樹脂組成物等を用いることができる。活性エネルギー線硬化性組成物としては、特に限定されないが、例えば、分子中に少なくとも２個の（メタ）アクリロイルオキシ基を有する重合性化合物等を用いることができる。これらの組成物は、１種単独で用いてもよく、２種以上を併用してもよい。 Thermoplastic resin compositions include, but are not particularly limited to, styrene resin compositions, vinyl acetate resin compositions, polyester resin compositions, polyethylene resin compositions, polypropylene resin compositions, imide resin compositions, Also, acrylic resin compositions and the like can be used. The thermosetting resin composition is not particularly limited, but phenolic resin compositions, epoxy resin compositions, urethane resin compositions, melamine resin compositions, alkyd resin compositions, etc. can be used. can. The active energy ray-curable composition is not particularly limited, but for example, a polymerizable compound having at least two (meth)acryloyloxy groups in the molecule can be used. These compositions may be used alone or in combination of two or more.
保護層３０には、必要に応じて、硬化促進剤、粘着性付与剤、酸化防止剤、顔料、染料、可塑剤、紫外線吸収剤、消泡剤、レベリング剤、充填剤、難燃剤、粘度調整剤、及び、ブロッキング防止剤等が含まれていてもよい。 The protective layer 30 contains a curing accelerator, a tackifier, an antioxidant, a pigment, a dye, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling agent, a filler, a flame retardant, and a viscosity adjuster, as necessary. and an antiblocking agent may also be included.
なお、本発明の電磁波シールドフィルムでは、保護層は任意の構成であり、保護層は形成されていなくてもよい。 In addition, in the electromagnetic shielding film of the present invention, the protective layer has an arbitrary structure, and the protective layer does not need to be formed.
本発明の電磁波シールドフィルムは、電磁波シールドフィルムの導電性粘着剤の粘着力により被着体に貼付される。
本発明の電磁波シールドフィルムが被着体に貼付された後も導電性粘着剤は硬化せず柔軟性を有する。そのため、本発明の電磁波シールドフィルムが可動部に被着され、可動部が動いたとしても、本発明の電磁波シールドフィルムは、損傷しにくく、可動部から剥がれにくい。
そのため、本発明の電磁波シールドフィルムは、可動部に貼付する電磁波シールドフィルムとして適している。 The electromagnetic shielding film of the present invention is attached to an adherend by the adhesive force of the conductive adhesive of the electromagnetic shielding film.
Even after the electromagnetic shielding film of the present invention is attached to an adherend, the conductive adhesive does not harden and remains flexible. Therefore, even if the electromagnetic shielding film of the present invention is applied to a movable part and the movable part moves, the electromagnetic shielding film of the present invention will not be easily damaged and will not easily peel off from the movable part.
Therefore, the electromagnetic shielding film of the present invention is suitable as an electromagnetic shielding film to be attached to a movable part.
次に、本発明の電磁波シールドフィルムの製造方法について説明する。
本発明の電磁波シールドフィルムを製造する場合、まず、導電性粒子と、樹脂組成物とを混合し、導電性粘着組成物を作製する。
この際、導電性粘着組成物に、溶剤やその他の添加物を加えてもよい。 Next, a method for manufacturing the electromagnetic shielding film of the present invention will be explained.
When manufacturing the electromagnetic shielding film of the present invention, first, conductive particles and a resin composition are mixed to prepare a conductive adhesive composition.
At this time, a solvent and other additives may be added to the conductive adhesive composition.
溶剤としては、例えば、キシレン、トルエン、ｔｅｒｔ―ブチルアルコール、酢酸エチル、メチルエチルケトンなどが挙げられる。 Examples of the solvent include xylene, toluene, tert-butyl alcohol, ethyl acetate, and methyl ethyl ketone.
次に、セパレータフィルム等の第１基材の上に、導電性粘着組成物を塗布し、必要に応じて、加熱等により脱溶媒及び／又は一部硬化させて導電性粘着剤を形成する。上記加熱は、例えば２５～１００℃で１～７２時間程度行うことが好ましい。 Next, a conductive adhesive composition is applied onto the first base material such as a separator film, and if necessary, the solvent is removed and/or partially cured by heating or the like to form a conductive adhesive. The above heating is preferably performed at, for example, 25 to 100° C. for about 1 to 72 hours.
なお、導電性粘着組成物の塗布には、公知のコーティング法を採用することができる。例えば、グラビアロールコーター、リバースロールコーター、キスロールコーター、リップコーターディップロールコーター、バーコーター、ナイフコーター、スプレーコーター、コンマコーター、ダイレクトコーター、スロットダイコーターなどのコーターを用いることができる。 Note that a known coating method can be used to apply the conductive adhesive composition. For example, coaters such as a gravure roll coater, reverse roll coater, kiss roll coater, lip coater dip roll coater, bar coater, knife coater, spray coater, comma coater, direct coater, and slot die coater can be used.
基材に接する側の導電性粘着剤の主面は第１主面となり、基材に接しない側の導電性粘着剤の主面は第２主面となる。 The main surface of the conductive adhesive on the side that is in contact with the base material is the first main surface, and the main surface of the conductive adhesive on the side that is not in contact with the base material is the second main surface.
次に、第２基材の上に、保護層を形成するための組成物を塗布又はラミネートし、保護層の上にさらにシールド層を形成する。
保護層を形成するための組成物の塗布方法及びラミネート方法や、シールド層の形成方法は、従来公知の方法を用いることができる。 Next, a composition for forming a protective layer is applied or laminated onto the second base material, and a shield layer is further formed on the protective layer.
Conventionally known methods can be used for applying and laminating the composition for forming the protective layer and for forming the shield layer.
その後、第１基材に形成された粘着性組成物と、第２基材のシールド層とを張り合わせることにより、本発明の電磁波シールドフィルムを製造することができる。 Thereafter, the electromagnetic shielding film of the present invention can be manufactured by laminating the adhesive composition formed on the first base material and the shielding layer of the second base material.
このように製造された電磁波シールドフィルムを被着体に貼付する場合、まず、第１基材を剥離し、導電性粘着剤の第１主面に被着体を接触させる。この際、電磁波シールドフィルムが被着体から剥離しないように、電磁波シールドフィルムに圧力をかける。その後、第２基材を剥離する。
これにより、本発明の電磁波シールドフィルムを被着体に貼付することができる。 When attaching the electromagnetic shielding film manufactured in this way to an adherend, first, the first base material is peeled off, and the adherend is brought into contact with the first main surface of the conductive adhesive. At this time, pressure is applied to the electromagnetic shielding film so that the electromagnetic shielding film does not peel off from the adherend. After that, the second base material is peeled off.
Thereby, the electromagnetic shielding film of the present invention can be attached to an adherend.
次に、本発明の電磁波シールドフィルムを備えるシールドプリント配線板について説明する。 Next, a shield printed wiring board including the electromagnetic shielding film of the present invention will be explained.
図３は、本発明の第１実施形態に係る電磁波シールドフィルムを備えるシールドプリント配線板の一例を模式的に示す断面図である。 FIG. 3 is a cross-sectional view schematically showing an example of a shield printed wiring board including an electromagnetic shielding film according to the first embodiment of the present invention.
図３に示すシールドプリント配線板６０は、プリント配線板５０と、電磁波シールドフィルム４０とからなる。
プリント配線板５０は、ベースフィルム５１と、ベースフィルム５１の上に配置されたプリント回路５２と、プリント回路５２を覆うように配置されたカバーレイ５３とを備える。
プリント配線板５０では、プリント回路５２はグランド回路５２ａを含み、カバーレイ５３にはグランド回路５２ａを露出する開口部５３ａが形成されている。 A shield printed wiring board 60 shown in FIG. 3 includes a printed wiring board 50 and an electromagnetic shielding film 40.
The printed wiring board 50 includes a base film 51, a printed circuit 52 placed on the base film 51, and a coverlay 53 placed so as to cover the printed circuit 52.
In the printed wiring board 50, the printed circuit 52 includes a ground circuit 52a, and the coverlay 53 has an opening 53a that exposes the ground circuit 52a.
シールドプリント配線板６０では、カバーレイ５３と導電性粘着剤１０とが接するように、プリント配線板５０の上に、電磁波シールドフィルム４０が配置されている。 In the shield printed wiring board 60, the electromagnetic shielding film 40 is arranged on the printed wiring board 50 so that the coverlay 53 and the conductive adhesive 10 are in contact with each other.
シールドプリント配線板６０では、導電性粘着剤１０が、カバーレイ５３の開口部５３ａを埋め、グランド回路５２ａと接触している。このような構成とすることにより、電磁波シールドフィルム４０のシールド特性を向上させることができる。 In the shield printed wiring board 60, the conductive adhesive 10 fills the opening 53a of the coverlay 53 and is in contact with the ground circuit 52a. With such a configuration, the shielding characteristics of the electromagnetic shielding film 40 can be improved.
プリント配線板５０において、ベースフィルム５１とカバーレイ５３は、いずれもエンジニアリングプラスチックからなることが好ましい。例えば、ポリプロピレン、架橋ポリエチレン、ポリエステル、ポリベンツイミダゾール、ポリイミド、ポリイミドアミド、ポリエーテルイミド、ポリフェニレンサルファイド（ＰＰＳ）等の樹脂が挙げられる。 In the printed wiring board 50, both the base film 51 and the coverlay 53 are preferably made of engineering plastic. Examples include resins such as polypropylene, crosslinked polyethylene, polyester, polybenzimidazole, polyimide, polyimide amide, polyetherimide, and polyphenylene sulfide (PPS).
プリント配線板５０において、プリント回路５２は、銅等の通常の回路用材料を用いることができる。 In the printed wiring board 50, the printed circuit 52 can be made of a common circuit material such as copper.
ベースフィルム５１とプリント回路５２とは、接着剤によって接着しても良いし、接着剤を用いない、いわゆる、無接着剤型銅張積層板と同様に接合しても良い。また、カバーレイ５３は、複数枚の可撓性絶縁フィルムを接着剤により貼り合わせたものであっても良く、感光性絶縁樹脂の塗工、乾燥、露光、現像、熱処理などの一連の手法によって形成しても良い。 The base film 51 and the printed circuit 52 may be bonded together using an adhesive, or may be bonded together without using an adhesive, similar to a so-called non-adhesive type copper clad laminate. Further, the coverlay 53 may be formed by bonding a plurality of flexible insulating films together with an adhesive, and is formed by a series of methods such as coating with photosensitive insulating resin, drying, exposure, development, and heat treatment. It may be formed.
電磁波シールドフィルム４０をプリント配線板５０の貼付する方法としては、従来公知の方法を採用することができる。
特に、電磁波シールドフィルム４０は、導電性粘着剤１０を有しているので、２３～６５℃、０．１～１．０ＭＰａのような、比較的低温、低圧の条件で貼付することができる。 As a method for attaching the electromagnetic shielding film 40 to the printed wiring board 50, a conventionally known method can be employed.
In particular, since the electromagnetic shielding film 40 includes the conductive adhesive 10, it can be attached at relatively low temperatures and pressures such as 23 to 65° C. and 0.1 to 1.0 MPa.
（第２実施形態）
本発明の第２実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の最大高さＲｚが１６μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第２実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大高さＲｚが１６μｍ以下であることを特徴とする。 (Second embodiment)
In the conductive adhesive according to the second embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" The configuration requirements are the same as those of the conductive adhesive according to the first embodiment of the present invention, except that the configuration requirement is changed to "the maximum height Rz of the first principal surface is 16 μm or less".
That is, the conductive adhesive according to the second embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. A conductive adhesive having a shape, characterized in that the storage modulus of the conductive adhesive at 65° C. is 1.6 × 10 Pa or more, and the maximum height Rz of the first principal surface is 16 μm or less. shall be.
なお、本発明の第２実施形態に係る導電性粘着剤では、第１主面の最大高さＲｚは、１５．５μｍ以下であることが好ましく、１５μｍ以下であることがより好ましい。
第１主面の最大高さＲｚが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第２実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the second embodiment of the present invention, the maximum height Rz of the first main surface is preferably 15.5 μm or less, more preferably 15 μm or less.
The fact that the maximum height Rz of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the second embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第２実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the second embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第２実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the second embodiment of the present invention other than these parameters are the same as preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第３実施形態）
本発明の第３実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の最大山高さＲｐが９．５μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第３実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大山高さＲｐが９．５μｍ以下であることを特徴とする。 (Third embodiment)
In the conductive adhesive according to the third embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" The configuration requirements are the same as those of the conductive adhesive according to the first embodiment of the present invention, except that the configuration requirement is changed to "the maximum peak height Rp of the first principal surface is 9.5 μm or less".
That is, the conductive adhesive according to the third embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The conductive adhesive has a storage elastic modulus of 1.6×10 4 Pa or more at 65° C., and a maximum peak height Rp of the first main surface is 9.5 μm or less. characterized by something.
なお、本発明の第３実施形態に係る導電性粘着剤では、第１主面の最大山高さＲｐは、８．６μｍ以下であることが好ましく、７．５μｍ以下であることがより好ましい。
第１主面の最大山高さＲｐが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第３実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the third embodiment of the present invention, the maximum peak height Rp of the first main surface is preferably 8.6 μm or less, more preferably 7.5 μm or less.
The fact that the maximum peak height Rp of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the third embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第３実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the third embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第３実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the third embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第４実施形態）
本発明の第４実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の最大谷深さＲｖが９μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第４実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大谷深さＲｖが９μｍ以下であることを特徴とする。 (Fourth embodiment)
In the conductive adhesive according to the fourth embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the maximum valley depth Rv of the first principal surface is 9 μm or less".
That is, the conductive adhesive according to the fourth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. a conductive adhesive having a storage elastic modulus of 1.6× 10 4 Pa or more at 65° C. and a maximum valley depth Rv of the first principal surface of 9 μm or less. It is characterized by
なお、本発明の第４実施形態に係る導電性粘着剤では、第１主面の最大谷深さＲｖは、８．８μｍ以下であることが好ましく、７μｍ以下であることがより好ましい。
第１主面の最大谷深さＲｖが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第４実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the fourth embodiment of the present invention, the maximum valley depth Rv of the first main surface is preferably 8.8 μm or less, more preferably 7 μm or less.
The fact that the maximum valley depth Rv of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the fourth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第４実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the fourth embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第４実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the fourth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第５実施形態）
本発明の第５実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の平均高さＲｃが１１μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第５実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の平均高さＲｃが１１μｍ以下であることを特徴とする。 (Fifth embodiment)
In the conductive adhesive according to the fifth embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the average height Rc of the first principal surface is 11 μm or less".
That is, the conductive adhesive according to the fifth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The electrically conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and the average height Rc of the first principal surface is 11 μm or less. It is characterized by
なお、本発明の第５実施形態に係る導電性粘着剤では、第１主面の平均高さＲｃは、１０．６μｍ以下であることが好ましく、１０．３μｍ以下であることがより好ましい。
第１主面の平均高さＲｃが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第５実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the fifth embodiment of the present invention, the average height Rc of the first main surface is preferably 10.6 μm or less, more preferably 10.3 μm or less.
The fact that the average height Rc of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the fifth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第５実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the fifth embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第５実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the fifth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第６実施形態）
本発明の第６実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の最大断面高さＲｔが１６μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第６実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大断面高さＲｔが１６μｍ以下であることを特徴とする。 (Sixth embodiment)
In the conductive adhesive according to the sixth embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the maximum cross-sectional height Rt of the first principal surface is 16 μm or less".
That is, the conductive adhesive according to the sixth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. a conductive adhesive having a storage elastic modulus of 1.6× 10 4 Pa or more at 65° C. and a maximum cross-sectional height Rt of the first principal surface of 16 μm or less. It is characterized by
なお、本発明の第６実施形態に係る導電性粘着剤では、第１主面の最大断面高さＲｔは、１５．５μｍ以下であることが好ましく、１５μｍ以下であることがより好ましい。
第１主面の最大断面高さＲｔが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第６実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the sixth embodiment of the present invention, the maximum cross-sectional height Rt of the first main surface is preferably 15.5 μm or less, more preferably 15 μm or less.
The fact that the maximum cross-sectional height Rt of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the sixth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第６実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the sixth embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第６実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the sixth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第７実施形態）
本発明の第７実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の二乗平均平方根高さＲｑが５μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第７実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の二乗平均平方根高さＲｑが５μｍ以下であることを特徴とする。 (Seventh embodiment)
In the conductive adhesive according to the seventh embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except for the constituent requirement that "the root mean square height Rq of the first principal surface is 5 μm or less".
That is, the conductive adhesive according to the seventh embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The electrically conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and the root mean square height Rq of the first principal surface is 5 μm or less. characterized by something.
なお、本発明の第７実施形態に係る導電性粘着剤では、第１主面の二乗平均平方根高さＲｑは、４．５μｍ以下であることが好ましく、４．１μｍ以下であることがより好ましい。
第１主面の二乗平均平方根高さＲｑが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第７実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the seventh embodiment of the present invention, the root mean square height Rq of the first principal surface is preferably 4.5 μm or less, more preferably 4.1 μm or less. .
The fact that the root mean square height Rq of the first principal surface is within the above range means that the first principal surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the seventh embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第７実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the seventh embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第７実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the seventh embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第８実施形態）
本発明の第８実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の十点平均粗さＲｚＪＩＳが１４μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第８実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の十点平均粗さＲｚＪＩＳが１４μｍ以下であることを特徴とする。 (Eighth embodiment)
In the conductive adhesive according to the eighth embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except that the constituent requirement is that "the ten-point average roughness RzJIS of the first principal surface is 14 μm or less".
That is, the conductive adhesive according to the eighth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. a conductive adhesive having a storage elastic modulus of 1.6×10 4 Pa or more at 65° C., and a ten-point average roughness RzJIS of the first principal surface of 14 μm or less; characterized by something.
なお、本発明の第８実施形態に係る導電性粘着剤では、第１主面の十点平均粗さＲｚＪＩＳは、１３．５μｍ以下であることが好ましく、１３．３μｍ以下であることがより好ましい。
第１主面の十点平均粗さＲｚＪＩＳが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第８実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the eighth embodiment of the present invention, the ten-point average roughness RzJIS of the first main surface is preferably 13.5 μm or less, more preferably 13.3 μm or less. .
The fact that the ten-point average roughness RzJIS of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the eighth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第８実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the eighth embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第８実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the eighth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第９実施形態）
本発明の第９実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面のコア部のレベル差Ｒｋが７μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第９実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面のコア部のレベル差Ｒｋが７μｍ以下であることを特徴とする。 (Ninth embodiment)
In the conductive adhesive according to the ninth embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" The configuration requirements are the same as those of the conductive adhesive according to the first embodiment of the present invention, except that the configuration requirement is changed to "the level difference Rk of the core portion of the first principal surface is 7 μm or less".
That is, the conductive adhesive according to the ninth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The conductive adhesive has a storage elastic modulus of 1.6× 10 4 Pa or more at 65° C., and a level difference Rk of the core portion of the first principal surface is 7 μm or less. characterized by something.
なお、本発明の第９実施形態に係る導電性粘着剤では、第１主面のコア部のレベル差Ｒｋは、６．８μｍ以下であることが好ましく、６．５μｍ以下であることがより好ましい。
第１主面のコア部のレベル差Ｒｋが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第９実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the ninth embodiment of the present invention, the level difference Rk of the core portion of the first main surface is preferably 6.8 μm or less, more preferably 6.5 μm or less. .
The fact that the level difference Rk of the core portion of the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the ninth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第９実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the ninth embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第９実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the ninth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
（第１０実施形態）
本発明の第１０実施形態に係る導電性粘着剤では、上記本発明の第１実施形態に係る導電性粘着剤における「第１主面の算術平均粗さＲａが４μｍ以下である」という構成要件が、「第１主面の要素の平均長さＲｄｃが７μｍ以下である」という構成要件に替わっている以外、本発明の第１実施形態に係る導電性粘着剤と同じ構成要件である。
すなわち、本発明の第１０実施形態に係る導電性粘着剤は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の要素の平均長さＲｄｃが７μｍ以下であることを特徴とする。 (10th embodiment)
In the conductive adhesive according to the tenth embodiment of the present invention, the constituent requirement of the conductive adhesive according to the first embodiment of the present invention is that "the arithmetic mean roughness Ra of the first principal surface is 4 μm or less" These are the same constituent requirements as the conductive adhesive according to the first embodiment of the present invention, except that the constituent requirement is "the average length Rdc of the elements on the first principal surface is 7 μm or less".
That is, the conductive adhesive according to the tenth embodiment of the present invention is a sheet comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface. The electrically conductive adhesive has a storage modulus of 1.6× 10 4 Pa or more at 65° C., and the average length Rdc of the elements on the first principal surface is 7 μm or less. characterized by something.
なお、本発明の第１０実施形態に係る導電性粘着剤では、第１主面の要素の平均長さＲｄｃは、６．６μｍ以下であることが好ましく、６．３μｍ以下であることがより好ましい。
第１主面の要素の平均長さＲｄｃが上記範囲内であることは、第１主面が平坦に近いことを意味している。
そのため、本発明の第１０実施形態に係る導電性粘着剤の第１主面に平坦な被着体を接触させると、第１主面と被着体とが密着しやすくなる。そのため、導電性粘着剤の粘着力が高くなる。 In addition, in the conductive adhesive according to the tenth embodiment of the present invention, the average length Rdc of the elements on the first main surface is preferably 6.6 μm or less, more preferably 6.3 μm or less. .
The fact that the average length Rdc of the elements on the first main surface is within the above range means that the first main surface is nearly flat.
Therefore, when a flat adherend is brought into contact with the first main surface of the conductive adhesive according to the tenth embodiment of the present invention, the first main surface and the adherend are likely to come into close contact with each other. Therefore, the adhesive force of the conductive adhesive becomes high.
また、本発明の第１０実施形態に係る導電性粘着剤では、第１主面の算術平均粗さＲａが４μｍ以下であることが好ましく、３．９７μｍ以下であることがより好ましく、３．６５μｍ以下であることがさらに好ましい。 Further, in the conductive adhesive according to the tenth embodiment of the present invention, the arithmetic mean roughness Ra of the first main surface is preferably 4 μm or less, more preferably 3.97 μm or less, and 3.65 μm or less. It is more preferable that it is the following.
これらのパラメータ以外の本発明の第１０実施形態に係る導電性粘着剤の好ましい態様は、本発明の第１実施形態に係る導電性粘着剤の好ましい態様と同じである。 Preferred aspects of the conductive adhesive according to the tenth embodiment of the present invention other than these parameters are the same as the preferred aspects of the conductive adhesive according to the first embodiment of the present invention.
本明細書には以下の事項が開示されている。 The following items are disclosed in this specification.
本開示（１）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の算術平均粗さＲａが４μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (1) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and an arithmetic mean roughness Ra of the first principal surface of 4 μm or less. be.
本開示（２）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大高さＲｚが１６μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (2) is a sheet-shaped conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and a maximum height Rz of the first principal surface is 16 μm or less. .
本開示（３）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大山高さＲｐが９．５μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (3) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, A conductive adhesive characterized in that the storage elastic modulus at 65° C. of the conductive adhesive is 1.6×10 4 Pa or more, and the maximum peak height Rp of the first principal surface is 9.5 μm or less. It is.
本開示（４）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大谷深さＲｖが９μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (4) is a sheet-shaped conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and a maximum valley depth Rv of the first principal surface is 9 μm or less. be.
本開示（５）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の平均高さＲｃが１１μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (5) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C., and an average height Rc of the first principal surface is 11 μm or less. .
本開示（６）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の最大断面高さＲｔが１６μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (6) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage modulus of 1.6× 10 4 Pa or more at 65° C., and a maximum cross-sectional height Rt of the first principal surface is 16 μm or less. be.
本開示（７）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の二乗平均平方根高さＲｑが５μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (7) is a sheet-shaped conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, A conductive adhesive characterized in that the storage elastic modulus at 65° C. of the conductive adhesive is 1.6×10 4 Pa or more, and the root mean square height Rq of the first principal surface is 5 μm or less. It is.
本開示（８）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の十点平均粗さＲｚＪＩＳが１４μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (8) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, A conductive adhesive characterized in that the storage modulus at 65° C. of the conductive adhesive is 1.6×10 4 Pa or more, and the ten-point average roughness RzJIS of the first principal surface is 14 μm or less. It is.
本開示（９）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面のコア部のレベル差Ｒｋが７μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (9) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage elastic modulus of 1.6× 10 4 Pa or more at 65° C., and a level difference Rk of the core portion of the first principal surface is 7 μm or less. It is.
本開示（１０）は、導電性粒子と、樹脂組成物とからなり、第１主面と、上記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、上記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、上記第１主面の要素の平均長さＲｄｃが７μｍ以下であることを特徴とする導電性粘着剤である。 The present disclosure (10) is a sheet-like conductive adhesive comprising conductive particles and a resin composition, and having a first main surface and a second main surface opposite to the first main surface, The conductive adhesive has a storage modulus of 1.6× 10 4 Pa or more at 65° C., and an average length Rdc of the elements on the first principal surface is 7 μm or less. It is.
本開示（１１）は、上記導電性粘着剤が、等方導電性又は異方導電性を有する本開示（１）～（１０）のいずれかに記載の導電性粘着剤である。 The present disclosure (11) is the conductive adhesive according to any one of the present disclosure (1) to (10), wherein the conductive adhesive has isotropic conductivity or anisotropic conductivity.
本開示（１２）は本開示（１）～（１１）のいずれかに記載の導電性粘着剤と、上記導電性粘着剤の第２主面に接するように積層されたシールド層とを備えることを特徴とする電磁波シールドフィルムである。 The present disclosure (12) includes the conductive adhesive according to any one of the present disclosures (1) to (11), and a shield layer laminated so as to be in contact with the second main surface of the conductive adhesive. This is an electromagnetic shielding film that features:
本開示（１３）は上記シールド層の上に形成された保護層をさらに備える本開示（１２）に記載の電磁波シールドフィルムである。 The present disclosure (13) is the electromagnetic wave shielding film according to the present disclosure (12), further comprising a protective layer formed on the shield layer.
（実施例１）
導電性粘着剤用の樹脂組成物として、アクリル系粘着剤を８４．５重量部、導電性粒子としてフィラメント状のニッケル粒子を１５重量部、硬化剤として、トルエンジイソシアネートを０．５重量部混合し、実施例１に係る導電性粘着組成物を作製した。 (Example 1)
As a resin composition for a conductive adhesive, 84.5 parts by weight of an acrylic adhesive, 15 parts by weight of filamentary nickel particles as conductive particles, and 0.5 parts by weight of toluene diisocyanate as a curing agent were mixed. A conductive adhesive composition according to Example 1 was prepared.
次に、第１基材として表面に離型剤処理がされたポリエチレンテレフタレートからなるセパレートフィルムを準備し、第１基材の表面にアプリケータを用いて、厚さ１３μｍになるように導電性粘着組成物を塗工した。 Next, a separate film made of polyethylene terephthalate whose surface has been treated with a release agent is prepared as a first base material, and a conductive adhesive is applied to the surface of the first base material using an applicator to a thickness of 13 μm. The composition was applied.
次に、第２基材として、表面に離型剤処理がされたポリエチレンテレフタレートからなるセパレートフィルムを準備し、第２基材の表面にアプリケータを用いて、厚さ５μｍになるように保護層用の樹脂組成物であるポリエステル系樹脂を塗工し保護層を形成した。
その後、保護層の上に、厚さ１０μｍの銅箔を配置した。 Next, a separate film made of polyethylene terephthalate whose surface has been treated with a release agent is prepared as a second base material, and a protective layer is applied to the surface of the second base material to a thickness of 5 μm using an applicator. A protective layer was formed by coating a polyester resin, which is a resin composition for
Thereafter, a 10 μm thick copper foil was placed on the protective layer.
次に、第１基材に配置された導電性粘着組成物と、第２基材に配置された銅箔とが接触するように、これらを張り合わせた。
その後、４０℃で３日間エージングを行い、実施例１に係る電磁波シールドフィルムを製造した。なお、エージングにより、導電性粘着組成物中の樹脂組成物と硬化剤とが反応し、導電性粘着剤となる。 Next, the conductive adhesive composition placed on the first base material and the copper foil placed on the second base material were pasted together so that they were in contact with each other.
Thereafter, aging was performed at 40° C. for 3 days to produce the electromagnetic shielding film according to Example 1. Note that due to aging, the resin composition and curing agent in the conductive pressure-sensitive adhesive composition react to form a conductive pressure-sensitive adhesive.
（実施例２）～（実施例９）及び（比較例１）～（比較例２）
使用した材料を表１及び表２に示す種類及び配合割合に変更した以外は、実施例１と同様に実施例２～実施例９及び比較例１～比較例２に係る電磁波シールドフィルムを製造した。
なお、表１及び表２中、導電性粘着剤の組成の数値は「重量部」を意味している。
また、表１及び表２に記載の材料の種類は以下の通りである。
下記導電性粒子１～導電性粒子３のメディアン径（Ｄ５０）は、粒度分布測定装置（マイクロトラックベル社製、ＭＴ３３００ＥＸＩＩ）を用いて測定した。
保護層用の樹脂組成物１：ポリエステル系樹脂／ＰＥＴ／ＰＳＡ（黒）
保護層用の樹脂組成物２：ポリエステル系樹脂／ＰＥＴ／ＰＳＡ（透明）
導電性粘着剤用の樹脂組成物：アクリル系粘着剤
導電性粒子１：フィラメント状のニッケル粒子（メディアン径（Ｄ５０）：２０μｍ）
導電性粒子２：デンドライト状の銀コート銅粒子（メディアン径（Ｄ５０）：１２μｍ）
導電性粒子３：アトマイズ法により作製した銀コート銅粒子（メディアン径（Ｄ５０）：５μｍ）
硬化剤：トルエンジイソシアネート (Example 2) - (Example 9) and (Comparative example 1) - (Comparative example 2)
Electromagnetic shielding films according to Examples 2 to 9 and Comparative Examples 1 to 2 were manufactured in the same manner as in Example 1, except that the materials used were changed to the types and blending ratios shown in Tables 1 and 2. .
Note that in Tables 1 and 2, the numerical values for the composition of the conductive adhesive mean "parts by weight."
Further, the types of materials listed in Tables 1 and 2 are as follows.
The median diameter (D 50 ) of Conductive Particles 1 to 3 below was measured using a particle size distribution analyzer (manufactured by Micro Track Bell Co., Ltd., MT3300EXII).
Resin composition 1 for protective layer: Polyester resin/PET/PSA (black)
Resin composition 2 for protective layer: Polyester resin/PET/PSA (transparent)
Resin composition for conductive adhesive: Acrylic adhesive Conductive particles 1: Filament-shaped nickel particles (median diameter (D 50 ): 20 μm)
Conductive particles 2: dendrite-like silver-coated copper particles (median diameter (D 50 ): 12 μm)
Conductive particles 3: Silver-coated copper particles produced by atomization method (median diameter (D 50 ): 5 μm)
Curing agent: toluene diisocyanate
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
（貯蔵弾性率の測定）
各実施例及び各比較例に係る導電性粘着剤について、６５℃における貯蔵弾性率を、Ａｎｔｏｎ　Ｐａａｒ社製の「Ｍｏｄｕｌａｒ　Ｃｏｍｐａｃｔ　Ｒｈｅｏｍｅｔｅｒ（ＭＣＲ）　３０２」を用いて測定した。結果を表１及び表２に示す。 (Measurement of storage modulus)
The storage modulus at 65° C. of the conductive adhesives according to each example and each comparative example was measured using “Modular Compact Rheometer (MCR) 302” manufactured by Anton Paar. The results are shown in Tables 1 and 2.
（導電性粘着剤の表面性状の測定）
各実施例及び各比較例に係る電磁波シールドフィルムにおいて、第１基材を剥離し、導電性粘着剤の第１主面を露出させ、コンフォーカル顕微鏡（Ｌａｓｅｒｔｅｃ社製、ＯＰＴＥＬＩＣＳ　ＨＹＢＲＩＤ、対物レンズ２０倍）を用いて、第１主面の任意の５か所を測定した後、データ解析ソフト（ＬＭｅｙｅ７）を用い、ＪＩＳ　Ｂ　０６０１：２０１３及びＪＩＳ　Ｂ０６７１－２：２００２に準拠して、Ｒａ、Ｒｚ、Ｒｐ、Ｒｖ、Ｒｃ、Ｒｔ、Ｒｑ、ＲｚＪＩＳ、Ｒｄｃ及びＲｋを測定した。結果を表１及び表２に示す。 (Measurement of surface properties of conductive adhesive)
In the electromagnetic shielding film according to each example and each comparative example, the first base material was peeled off to expose the first main surface of the conductive adhesive, and the film was exposed to a confocal microscope (manufactured by Lasertec, OPTELICS HYBRID, objective lens 20x). ) to measure five arbitrary locations on the first main surface, then use data analysis software (LMeye7) to measure Ra, Rz, Rp, Rv, Rc, Rt, Rq, RzJIS, Rdc and Rk were measured. The results are shown in Tables 1 and 2.
（耐クリープ試験）
アルミニウム板（Ａ５０５２）に、縦１ｃｍ、横７ｃｍに切断した各実施例及び各比較例に係る電磁波シールドフィルムを、ローラにて２ｋｇｆの圧力をかけて圧着し、２４時間静置した。なお、電磁波シールドフィルムが圧着時に破損する場合、裏打ちフィルムで補強した。
次に、エスペック社製冷熱衝撃試験機（ＴＳＡ－４３ＥＬ－Ａ）に各実施例及び各比較例に係る電磁波シールドフィルムに荷重１ｋｇｆかかるよう設置し、０℃で３０分で静置した後、６５℃で３０分静置した、この工程を２４サイクル繰り返し、ヒートサイクル試験を実施し、耐クリープ性を評価した。
評価基準は以下の通りである。結果を表１及び表２に示す。
〇：２４サイクル後、電磁波シールドフィルムがアルミニウム板に張り付いていた。
×：２４サイクル後、電磁波シールドフィルムがアルミニウム板から剥離して脱落していた。 (Creep resistance test)
The electromagnetic shielding films according to the Examples and Comparative Examples cut into 1 cm long and 7 cm wide pieces were pressed onto an aluminum plate (A5052) using a roller under a pressure of 2 kgf, and left to stand for 24 hours. In addition, if the electromagnetic shielding film was damaged during pressure bonding, it was reinforced with a backing film.
Next, the electromagnetic wave shielding films according to each example and each comparative example were installed in a thermal shock tester (TSA-43EL-A) manufactured by ESPEC Corporation so that a load of 1 kgf was applied, and after being allowed to stand at 0°C for 30 minutes, This process was repeated for 24 cycles in which the sample was allowed to stand for 30 minutes at ℃, and a heat cycle test was conducted to evaluate the creep resistance.
The evaluation criteria are as follows. The results are shown in Tables 1 and 2.
○: After 24 cycles, the electromagnetic shielding film was stuck to the aluminum plate.
×: After 24 cycles, the electromagnetic shielding film was peeled off from the aluminum plate and fell off.
（剥離試験）
ＡＳＴＭ　Ｄ３３３０に規定する粘着テープ・粘着シート試験方法を用いた剥離試験を行った。具体的には、縦１２５ｍｍ、横２５ｍｍに切断した各実施例及び各比較例に係る電磁波シールドフィルムをステンレス材からなる試験板に貼り付け、引っ張り試験機によって試験板から１８０°方向に電磁波シールドフィルムを引き剥がした時の引張力を測定し粘着性を評価した。結果を表１及び表２に示す。なお、引き剥がした時の引張力が１Ｎ／２５ｍｍ以上であると、粘着力が充分に強いといえる。 (Peeling test)
A peel test was conducted using the adhesive tape/adhesive sheet test method specified in ASTM D3330. Specifically, the electromagnetic shielding film according to each example and each comparative example cut into 125 mm in length and 25 mm in width was attached to a test plate made of stainless steel material, and the electromagnetic shield film was cut in a 180° direction from the test plate using a tensile tester. The adhesion was evaluated by measuring the tensile force when peeled off. The results are shown in Tables 1 and 2. Note that if the tensile force when peeled off is 1 N/25 mm or more, it can be said that the adhesive force is sufficiently strong.
表１及び表２に示すように、導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、導電性粘着剤の表面性状のパラメータが本発明の範囲内である各実施例に係る電磁波シールドフィルムでは、耐クリープ性が高く、粘着性も高いことが判明した。
その一方で、導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ未満である比較例１に係る電磁波シールドフィルムは、耐クリープ性が低いことが判明した。
また、導電性粘着剤の表面性状のパラメータが本発明の範囲に含まれない比較例２に係る電磁波シールドフィルムでも耐クリープ性が低いことが判明した。 As shown in Tables 1 and 2, the storage modulus of the conductive adhesive at 65° C. is 1.6×10 4 Pa or more, and the parameters of the surface properties of the conductive adhesive are within the scope of the present invention. It was found that the electromagnetic shielding films according to each example had high creep resistance and high adhesiveness.
On the other hand, the electromagnetic shielding film according to Comparative Example 1 in which the conductive adhesive had a storage modulus of less than 1.6×10 4 Pa at 65° C. was found to have low creep resistance.
Furthermore, it was found that the electromagnetic shielding film according to Comparative Example 2, in which the parameters of the surface properties of the conductive adhesive were not included in the scope of the present invention, also had low creep resistance.
１０　導電性粘着剤
１１　第１主面
１２　第２主面
２０　シールド層
３０　保護層
４０　電磁波シールドフィルム
５０　プリント配線板
５１　ベースフィルム
５２　プリント回路
５２ａ　グランド回路
５３　カバーレイ
５３ａ　開口部
６０　シールドプリント配線板

  10 Conductive adhesive 11 First main surface 12 Second main surface 20 Shield layer 30 Protective layer 40 Electromagnetic shielding film 50 Printed wiring board 51 Base film 52 Printed circuit 52a Ground circuit 53 Coverlay 53a Opening 60 Shield printed wiring board

Claims (13)

  1. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の算術平均粗さＲａが４μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the first principal surface has an arithmetic mean roughness Ra of 4 μm or less.
  2. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の最大高さＲｚが１６μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the first principal surface has a maximum height Rz of 16 μm or less.
  3. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の最大山高さＲｐが９．５μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the first main surface has a maximum peak height Rp of 9.5 μm or less.
  4. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の最大谷深さＲｖが９μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the first principal surface has a maximum valley depth Rv of 9 μm or less.
  5. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の平均高さＲｃが１１μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the average height Rc of the first principal surface is 11 μm or less.
  6. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の最大断面高さＲｔが１６μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the first principal surface has a maximum cross-sectional height Rt of 16 μm or less.
  7. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の二乗平均平方根高さＲｑが５μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the root mean square height Rq of the first principal surface is 5 μm or less.
  8. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の十点平均粗さＲｚＪＩＳが１４μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the first principal surface has a ten-point average roughness RzJIS of 14 μm or less.
  9. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面のコア部のレベル差Ｒｋが７μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that a level difference Rk of the core portion of the first principal surface is 7 μm or less.
  10. 導電性粒子と、樹脂組成物とからなり、第１主面と、前記第１主面に対向する第２主面を有するシート状の導電性粘着剤であって、
    前記導電性粘着剤の６５℃における貯蔵弾性率が１．６×１０４Ｐａ以上であり、
    前記第１主面の要素の平均長さＲｄｃが７μｍ以下であることを特徴とする導電性粘着剤。     A sheet-shaped conductive adhesive comprising conductive particles and a resin composition and having a first main surface and a second main surface opposite to the first main surface,
    The conductive adhesive has a storage modulus of 1.6×10 4 Pa or more at 65° C.,
    A conductive adhesive characterized in that the average length Rdc of the elements on the first main surface is 7 μm or less.
  11. 前記導電性粘着剤は、等方導電性又は異方導電性を有する請求項１～１０のいずれか１項に記載の導電性粘着剤。 The conductive adhesive according to any one of claims 1 to 10, wherein the conductive adhesive has isotropic conductivity or anisotropic conductivity.
  12. 請求項１～１１のいずれか１項に記載の導電性粘着剤と、
    前記導電性粘着剤の第２主面に接するように積層されたシールド層とを備えることを特徴とする電磁波シールドフィルム。     The conductive adhesive according to any one of claims 1 to 11,
    An electromagnetic shielding film comprising: a shielding layer laminated so as to be in contact with the second main surface of the conductive adhesive.
  13. 前記シールド層の上に形成された保護層をさらに備える請求項１２に記載の電磁波シールドフィルム。

          The electromagnetic shielding film according to claim 12, further comprising a protective layer formed on the shielding layer.
PCT/JP2023/028059 2022-08-02 2023-08-01 Electroconductive adhesive and electromagnetic shield film WO2024029513A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022123454 2022-08-02
JP2022-123454 2022-08-02

Publications (1)

Publication Number Publication Date
WO2024029513A1 true WO2024029513A1 (en) 2024-02-08

Family

ID=89849343

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/028059 WO2024029513A1 (en) 2022-08-02 2023-08-01 Electroconductive adhesive and electromagnetic shield film

Country Status (2)

Country Link
TW (1) TW202407721A (en)
WO (1) WO2024029513A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006135118A (en) * 2004-11-08 2006-05-25 Shin Etsu Chem Co Ltd Electromagnetic wave absorbing heat radiation sheet
JP2013170197A (en) * 2012-02-20 2013-09-02 Nitto Denko Corp Tacky adhesive tape
JP2014145828A (en) * 2013-01-28 2014-08-14 Sumitomo Electric Ind Ltd Heating rotating body
JP2014154671A (en) * 2013-02-07 2014-08-25 Nitto Denko Corp Inter connector
JP2014234444A (en) * 2013-05-31 2014-12-15 日東電工株式会社 Electroconductive double-sided adhesive tape
JP2015028146A (en) * 2013-06-28 2015-02-12 日東電工株式会社 Adhesive product
JP2019201073A (en) * 2018-05-15 2019-11-21 積水化学工業株式会社 Electromagnetic wave shield film

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006135118A (en) * 2004-11-08 2006-05-25 Shin Etsu Chem Co Ltd Electromagnetic wave absorbing heat radiation sheet
JP2013170197A (en) * 2012-02-20 2013-09-02 Nitto Denko Corp Tacky adhesive tape
JP2014145828A (en) * 2013-01-28 2014-08-14 Sumitomo Electric Ind Ltd Heating rotating body
JP2014154671A (en) * 2013-02-07 2014-08-25 Nitto Denko Corp Inter connector
JP2014234444A (en) * 2013-05-31 2014-12-15 日東電工株式会社 Electroconductive double-sided adhesive tape
JP2015028146A (en) * 2013-06-28 2015-02-12 日東電工株式会社 Adhesive product
JP2019201073A (en) * 2018-05-15 2019-11-21 積水化学工業株式会社 Electromagnetic wave shield film

Also Published As

Publication number Publication date
TW202407721A (en) 2024-02-16

Similar Documents

Publication Publication Date Title
JP5221027B2 (en) Adhesive for bonding electromagnetic wave shielding film and optical functional film, and display panel filter element including the adhesive
KR101534644B1 (en) Electroconductive thin adhesive sheet
JP5554503B2 (en) Removable process film
KR101895738B1 (en) Thermosetting adhesive composition and thermosetting adhesive sheet
JP5896208B2 (en) Colored film and colored adhesive tape
KR101819529B1 (en) Conductive adhesive sheet and electronic device
JP4403360B2 (en) Conductive adhesive sheet
JP2014056967A (en) Conductive thin adhesive sheet
WO2019239710A1 (en) Electromagnetic wave shielding sheet
JP2014234444A (en) Electroconductive double-sided adhesive tape
KR20150144740A (en) Conductive adhesive sheet, method for manufacturing same and electronic terminal obtained by using same
JP2014001297A (en) Conductive adhesive tape
JP2018053102A (en) Conductive adhesive tape
WO2024029513A1 (en) Electroconductive adhesive and electromagnetic shield film
US10887999B2 (en) Mounting body manufacturing method and anisotropic conductive film
JP6431998B1 (en) Conductive adhesive layer
KR20190114890A (en) Electromagnetic wave shield film, shield printed circuit board and method for manufacturing shield printed circuit
JP6969172B2 (en) Conductive adhesive sheet
JP7363864B2 (en) Conductive adhesive sheets and portable electronic devices
JP2019201073A (en) Electromagnetic wave shield film
WO2019239955A1 (en) Electrically conductive adhesive sheet
JP6794592B1 (en) Isotropic conductive adhesive sheet
WO2020241818A1 (en) Isotropically electroconductive pressure-sensitive adhesive sheet
CN218969137U (en) Conductive adhesive sheet
WO2024185835A1 (en) Laminate and electromagnetic wave shielding film

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23850067

Country of ref document: EP

Kind code of ref document: A1