WO2022255438A1 - Electromagnetic wave shield film - Google Patents

Electromagnetic wave shield film Download PDF

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Publication number
WO2022255438A1
WO2022255438A1 PCT/JP2022/022433 JP2022022433W WO2022255438A1 WO 2022255438 A1 WO2022255438 A1 WO 2022255438A1 JP 2022022433 W JP2022022433 W JP 2022022433W WO 2022255438 A1 WO2022255438 A1 WO 2022255438A1
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WO
WIPO (PCT)
Prior art keywords
layer
electromagnetic wave
conductive adhesive
shielding film
inorganic
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PCT/JP2022/022433
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French (fr)
Japanese (ja)
Inventor
茂樹 竹下
晃司 高見
正博 渡辺
Original Assignee
タツタ電線株式会社
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Application filed by タツタ電線株式会社 filed Critical タツタ電線株式会社
Priority to CN202280038757.2A priority Critical patent/CN117397379A/en
Priority to JP2023525905A priority patent/JPWO2022255438A1/ja
Publication of WO2022255438A1 publication Critical patent/WO2022255438A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B9/00—Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
    • 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 an electromagnetic wave shielding film. More particularly, the present invention relates to electromagnetic wave shielding films used in printed wiring boards.
  • Printed wiring boards are often used to incorporate circuits into the mechanisms of electronic devices such as mobile phones, video cameras, and laptop computers. It is also used to connect a movable part such as a printer head and a control part. These electronic devices require measures to shield against electromagnetic waves, and the printed wiring boards used in the devices also use shield printed wiring boards that take measures to shield against electromagnetic waves.
  • shield film An electromagnetic wave shielding film (hereinafter sometimes simply referred to as "shielding film”) is used for the shield printed wiring board.
  • a shield film that is used by adhering to a printed wiring board has a shield layer such as a metal layer and a conductive adhesive sheet provided on the surface of the shield layer.
  • shield film having a conductive adhesive sheet for example, those disclosed in Patent Documents 1 and 2 are known.
  • the above-mentioned shield film is used by laminating such that the surface where the conductive adhesive sheet is exposed is adhered to the surface of the printed wiring board, specifically the surface of the coverlay provided on the surface of the printed wiring board.
  • These conductive adhesive sheets are usually adhered and laminated on a printed wiring board by thermocompression bonding under high temperature and high pressure conditions.
  • the shielding film arranged on the printed wiring board in this way exhibits the performance (shielding performance) of shielding electromagnetic waves from the outside of the printed wiring board.
  • the shield film is used by bonding it to the substrate under high temperature and high pressure conditions.
  • high temperature and high pressure conditions cannot be applied.
  • conventional shielding films have the problem of being inferior in adhesion strength and electrical connection stability when bonded to a substrate under relatively mild conditions.
  • the present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetic wave shielding film that can be easily adhered to an adherend, has excellent adhesion and electrical connection stability, and has excellent environmental resistance. to provide.
  • an electromagnetic wave shielding film having a specific layer structure can be easily adhered to an adherend and has excellent adhesion and electrical connection stability. It was found to be excellent in environmental resistance.
  • the present invention has been completed based on these findings.
  • a metal layer, a first inorganic layer, and a conductive adhesive layer are laminated in this order,
  • the thickness of the first inorganic layer is 0.1 to 100 nm
  • the conductive adhesive layer contains a binder component and conductive particles
  • an electromagnetic wave shielding film Provided is an electromagnetic wave shielding film, wherein the ratio of the thickness of the conductive adhesive layer to the median diameter of the conductive particles is 0.2 to 3.5.
  • an insulating protective layer is directly laminated on the surface of the metal layer opposite to the first inorganic layer.
  • the thickness of the second inorganic layer is preferably 0.1 to 100 nm.
  • the second inorganic layer is preferably made of metal oxide.
  • the first inorganic layer is preferably made of metal oxide.
  • the first inorganic layer is preferably laminated directly with the metal layer.
  • the conductive adhesive layer is preferably laminated directly with the first inorganic layer.
  • the present invention also provides a shield printed wiring board comprising the electromagnetic wave shielding film.
  • the electromagnetic wave shielding film of the present invention can be easily adhered to an adherend, yet has excellent adhesion to the adherend, excellent electrical connection stability, and excellent environmental resistance. Therefore, the electromagnetic wave shielding film of the present invention can be used even for substrates having poor resistance to high temperatures and high pressures. Moreover, it can be used in an environment where environmental resistance is required.
  • the electromagnetic wave shielding film (shielding film) of the present invention has a layer structure in which a metal layer, a first inorganic layer, and a conductive adhesive layer are laminated in this order.
  • the first inorganic layer is directly laminated with the metal layer.
  • the conductive adhesive layer is preferably laminated directly with the first inorganic layer. preferable.
  • the metal layer on the side opposite to the first inorganic layer It is preferable to provide an insulating protective layer on the surface. It is preferable that the insulating protective layer is directly laminated on the metal layer.
  • FIG. 1 is a schematic cross-sectional view showing one embodiment of the shielding film of the present invention.
  • the shield film 1 shown in FIG. 1 has an insulating protective layer 2, a metal layer 3, a first inorganic layer 4, and a conductive adhesive layer 5 in this order.
  • the insulating protective layer 2, the metal layer 3, the first inorganic layer 4, and the conductive adhesive layer 5 are directly laminated to adjacent layers.
  • the conductive adhesive layer has, for example, adhesiveness and adhesiveness for adhering the shield film of the present invention to a printed wiring board, and electrical conductivity for electrically connecting with the metal layer. In addition, it can function as a shield layer exhibiting shielding performance together with the metal layer.
  • the conductive adhesive layer may be a single layer or multiple layers.
  • the conductive adhesive layer contains a binder component and conductive particles.
  • binder component examples include thermoplastic resins, thermosetting resins, and active energy ray-curable compounds. Only one type of the binder component may be used, or two or more types may be used.
  • thermoplastic resin examples include polystyrene-based resin, vinyl acetate-based resin, polyester-based resin, polyolefin-based resin (polyethylene-based resin, polypropylene-based resin, etc.), polyamide-based resin, rubber-based resin, acrylic-based resin, silicone-based resin, etc. is mentioned. Only one type of the thermoplastic resin may be used, or two or more types may be used.
  • thermosetting resin examples include both resins having thermosetting properties (thermosetting resins) and resins obtained by curing the above thermosetting resins.
  • thermosetting resin examples include phenol-based resins, epoxy-based resins, urethane-based resins, melamine-based resins, alkyd-based resins, acrylic-based resins, and the like. Only one kind of the thermosetting resin may be used, or two or more kinds thereof may be used.
  • epoxy resin examples include bisphenol type epoxy resin, spirocyclic epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, terpene type epoxy resin, glycidyl ether type epoxy resin, glycidyl amine type Epoxy-based resins, novolak-type epoxy-based resins, and the like are included.
  • Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetrabromobisphenol A type epoxy resin, and the like.
  • Examples of the glycidyl ether type epoxy resin include tris(glycidyloxyphenyl)methane and tetrakis(glycidyloxyphenyl)ethane.
  • Examples of the glycidylamine type epoxy resin include tetraglycidyldiaminodiphenylmethane.
  • Examples of the novolak type epoxy resin include cresol novolak type epoxy resin, phenol novolak type epoxy resin, ⁇ -naphthol novolak type epoxy resin, and brominated phenol novolak type epoxy resin.
  • the active energy ray-curable compounds include both compounds that can be cured by irradiation with active energy rays (active energy ray-curable compounds) and compounds obtained by curing the active energy ray-curable compounds.
  • the active energy ray-curable compound is not particularly limited, but for example, a polymerizable compound having one or more (preferably two or more) radical reactive groups (e.g., (meth)acryloyl groups) in the molecule. mentioned. Only 1 type may be used for the said active-energy-ray-curable compound, and 2 or more types may be used for it.
  • the conductive adhesive layer has tackiness, and when the shield film of the present invention is used by being attached to an adherend such as a printed wiring board, it can be easily attached without being subjected to high temperature and high pressure conditions. can be matched.
  • the binder component When the binder component contains a thermosetting resin, it may contain a curing agent for accelerating the thermosetting reaction as a constituent component of the binder component.
  • the curing agent can be appropriately selected according to the type of the thermosetting resin. Only one kind of the curing agent may be used, or two or more kinds thereof may be used.
  • Examples of the conductive particles include metal particles, metal-coated resin particles, metal fibers, carbon fillers, and carbon nanotubes.
  • metals constituting the coating portion of the metal particles and the metal-coated resin particles include gold, silver, copper, nickel, zinc, indium, tin, lead, bismuth, and alloys containing two or more of these. . Only one kind of the above metals may be used, or two or more kinds thereof may be used.
  • the metal particles include copper particles, silver particles, nickel particles, silver-coated copper particles, indium particles, tin particles, lead particles, bismuth particles, gold-coated copper particles, silver-coated nickel particles, gold coated nickel particles, indium-coated copper particles, tin-coated copper particles, lead-coated copper particles, bismuth-coated copper particles, indium-coated nickel particles, tin-coated nickel particles, bismuth-coated nickel particles, silver-coated alloy particles, and the like.
  • 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.
  • the 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, silver-coated copper alloy particles, nickel particles, and silver-coated nickel particles are preferable.
  • Silver-coated copper particles and silver-coated copper alloy particles are particularly preferred from the viewpoints of excellent conductivity, suppression of oxidation and agglomeration of the metal particles, and reduction in the cost of the metal particles.
  • metal-coated resin particles include silver-coated resin particles, gold-coated resin particles, indium-coated resin particles, tin-coated resin particles, lead-coated resin particles, and bismuth-coated resin particles.
  • Examples of the shape of the conductive particles include spherical, flake-like (scale-like), dendritic (dendrite-like), fibrous (filament-like), amorphous (polyhedral), and spike-like shapes.
  • the median diameter (D50) of the conductive particles is preferably 1-50 ⁇ m, more preferably 3-40 ⁇ m. When the median diameter is 1 ⁇ m or more, the dispersibility of the conductive particles is good and aggregation can be suppressed. When the average particle size is 50 ⁇ m or less, the conductivity becomes good.
  • the median diameter is the median diameter of all the conductive particles in the conductive adhesive layer, and refers to the particle size at 50% of the integrated value in the particle size distribution determined by the laser diffraction/scattering method. When the median diameter is within the above range, the connection stability is more excellent.
  • the median diameter can be measured, for example, with a laser diffraction particle size distribution analyzer (trade name “SALD-2200”, manufactured by Shimadzu Corporation).
  • the conductive adhesive layer can be a layer having isotropic conductivity or anisotropic conductivity depending on the application.
  • the content of the conductive particles in the conductive adhesive layer is preferably 3 to 95% by mass, more preferably 5 to 90% by mass, with respect to 100% by mass of the total amount of the conductive adhesive layer. be. In the case of forming an isotropically conductive conductive adhesive layer, it can be 40 to 95% by mass. In the case of forming an anisotropically conductive conductive adhesive layer, it can be 3 to 40% by mass.
  • the conductive adhesive layer may contain components other than the components described above within a range that does not impair the effects of the present invention.
  • the above-mentioned other components include components contained in known or commonly used adhesive layers.
  • the above other components include curing accelerators, plasticizers, flame retardants, defoaming agents, viscosity modifiers, antioxidants, diluents, anti-settling agents, fillers, leveling agents, coupling agents, and UV absorbers. agents, tackifying resins, antiblocking agents, and the like. Only one kind of the other components may be used, or two or more kinds thereof may be used.
  • the thickness of the conductive adhesive layer is not particularly limited, it is preferably 3-20 ⁇ m, more preferably 5-18 ⁇ m. When the thickness is 3 ⁇ m or more, the adhesiveness to the adherend is more excellent. Moreover, it is superior in environmental resistance. When the thickness is 20 ⁇ m or less, the connection stability is excellent even when adhered to a printed wiring board under relatively mild conditions.
  • the ratio of the thickness of the conductive adhesive layer to the D50 of the conductive particles is 0.2 to 3.5, preferably 0.3 to 3.0. .
  • the adhesion to adherends such as printed wiring boards becomes better.
  • the above ratio is 3.5 or less, the amount of conductive particles exposed from the surface of the conductive adhesive layer is increased, and connection stability is ensured even when adhered to a printed wiring board under relatively mild conditions.
  • the first inorganic layer is a layer that protects the metal layer.
  • the first inorganic layer By interposing the first inorganic layer between the metal layer and the conductive adhesive layer, the surface of the metal layer on the side provided with the conductive adhesive layer is protected, and in a high-temperature and high-humidity environment, the above-mentioned It is possible to suppress deterioration of the connection stability due to deterioration of the metal layer, that is, excellent environmental resistance. It is presumed that the deterioration of the connection stability is caused by the deterioration of the metal layer due to the moisture or the like in the conductive adhesive layer.
  • the first inorganic layer may be a single layer or multiple layers.
  • Examples of inorganic substances that constitute the first inorganic layer include metal oxides and other inorganic oxides. Only one kind of the inorganic substance may be used, or two or more kinds thereof may be used.
  • Examples of the inorganic oxide include aluminum oxide (alumina), magnesium oxide, antimony oxide, titanium oxide, chromium oxide, zirconium oxide, zinc oxide, nickel oxide, palladium oxide, tungsten oxide, indium oxide, and ITO (Indium Tin Oxide). ; indium tin oxide) and silicon oxide.
  • Examples of the alkaline earth metal salt include fluoride salts such as magnesium fluoride and calcium fluoride.
  • Examples of metal salts other than alkaline earth metal salts include aluminum silicate, aluminum hydroxide, and zinc sulfide.
  • inorganic oxides are preferable, and metal oxides are more preferable, and titanium oxide, chromium oxide, and zirconium oxide are more preferable from the viewpoint of superior environmental resistance and economic efficiency.
  • Examples of methods for forming the first inorganic layer include electrolysis, vapor deposition (eg, vacuum vapor deposition), sputtering, CVD, metal organic (MO), plating, and rolling. Among them, an inorganic layer formed by vapor deposition, sputtering, or plating is preferable from the viewpoint of ease of manufacture.
  • the thickness of the first inorganic layer is 0.1 to 100 nm, preferably 0.1 to 20 nm, more preferably 0.1 to 10 nm, still more preferably 0.1 to 5 nm, particularly preferably 0.1 ⁇ 2.2 nm.
  • the thickness is 0.1 nm or more, the environmental resistance is excellent.
  • the thickness is 100 nm or less, the connection stability is excellent even when the adhesive is adhered to the printed wiring board under relatively mild conditions.
  • the thickness of the first inorganic layer is the total thickness of all layers.
  • the metal layer is an element that functions as a shield layer in the shield film of the present invention.
  • the metal layer may be a single layer or a laminate of the same or different types.
  • metals forming the metal layer include gold, silver, copper, aluminum, lithium, nickel, tin, palladium, chromium, titanium, zinc, and alloys thereof.
  • the alloy include silver/copper alloy, magnesium/copper alloy, magnesium/silver alloy, magnesium/aluminum alloy, magnesium/indium alloy, lithium/aluminum alloy, ITO (Indium Tin Oxide; indium tin oxide), and the like. mentioned.
  • copper and silver are preferable from the viewpoint of excellent electromagnetic wave shielding performance, and silver/copper alloy is preferable from the viewpoint of excellent migration resistance and sulfurization resistance.
  • the method of forming the metal layer is not particularly limited, and examples include electrolysis, vapor deposition (eg, vacuum vapor deposition), sputtering, CVD, metal organic (MO), plating, and rolling. Among them, a metal layer formed by vapor deposition, plating, or sputtering is preferable from the viewpoint of ease of manufacture.
  • the thickness of the metal layer is not particularly limited, it is, for example, 5 nm to 15 ⁇ m, preferably 5 nm to 13 ⁇ m.
  • the thickness of the metal layer is the sum of all layer thicknesses.
  • the insulating protective layer has insulating properties and protects the inner layers of the shield film of the present invention. By providing the insulating protective layer, it is possible to improve the environmental resistance of the surface of the metal layer on which the first inorganic layer is not provided, and to further suppress the deterioration of the connection stability.
  • the insulating protective layer may be a single layer or multiple layers.
  • the insulating protective layer examples include a resin layer formed mainly from a resin, or an inorganic layer formed from an inorganic substance.
  • the insulating protective layer is an inorganic layer, the environmental resistance is further improved.
  • the insulating protective layer is a resin layer, it functions as a support in the shield film of the present invention.
  • the insulating protective layer may be a single layer or a laminate of the same or different types.
  • the insulating protective layer preferably has a resin layer and an inorganic layer.
  • the inorganic layer is preferably on the metal layer side.
  • the inorganic layer that can be included in the insulating protective layer may be referred to as a "second inorganic layer".
  • the second inorganic layer is preferably laminated directly on the metal layer from the viewpoint of better environmental resistance.
  • FIG. 2 shows an embodiment of the shield film of the present invention in which the insulating protective layer comprises a resin layer and a second inorganic layer.
  • the insulating protective layer 2 has a laminate structure of a resin layer 21 and a second inorganic layer 22, and is composed of the laminate structure.
  • the second inorganic layer 22 is arranged on the metal layer 3 side and the resin layer 21 is arranged on the outermost surface, and the second inorganic layer 22 is directly laminated on the metal layer 3 .
  • Examples of the resin constituting the resin layer in the insulating protective layer include thermoplastic resins, thermosetting resins, and active energy ray compounds. It is preferably a type compound. Only one kind of the above resin may be used, or two or more kinds thereof may be used.
  • thermoplastic resin examples include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, poly Methylpentene, ethylene-vinyl acetate copolymer (EVA), ionomer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer , Polyolefin resins such as ethylene-hexene copolymer; polyurethane; polyester such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT); polycarbonate (PC); polyimide (PI); ); Polyetherimide; Aramid, polyamide such as wholly
  • thermosetting resin examples include both resins having thermosetting properties (thermosetting resins) and resins obtained by curing the above thermosetting resins.
  • thermosetting resin examples include phenol-based resins, epoxy-based resins, urethane-based resins, melamine-based resins, alkyd-based resins, imide-based resins, amide-based resins, polyamideimide-based resins, polyphenylsulfide-based resins, liquid crystals, Examples include polymers (LCP) and acrylic resins. Only one kind of the thermosetting resin may be used, or two or more kinds thereof may be used.
  • the active energy ray-curable compounds include both compounds that can be cured by irradiation with active energy rays (active energy ray-curable compounds) and compounds obtained by curing the active energy ray-curable compounds.
  • the active energy ray-curable compound is not particularly limited, but for example, a polymerizable compound having one or more (preferably two or more) radical reactive groups (e.g., (meth)acryloyl groups) in the molecule. mentioned. Only 1 type may be used for the said active-energy-ray-curable compound, and 2 or more types may be used for it.
  • the surface of the resin layer (especially the surface on the side of the metal layer) may be subjected to, for example, corona discharge treatment, plasma treatment, sand mat treatment, and the like, for the purpose of enhancing adhesion and retention with adjacent layers such as the metal layer.
  • Physical treatment such as ozone exposure treatment, flame exposure treatment, high voltage shock exposure treatment, ionizing radiation treatment; chemical treatment such as chromic acid treatment; surface treatment such as easy adhesion treatment with coating agent (undercoat). good too. It is preferable that the surface treatment for enhancing adhesion is applied to the entire surface of the resin layer on the metal layer side.
  • the thickness of the resin layer is not particularly limited, it is preferably 1 to 20 ⁇ m, more preferably 1 to 4 ⁇ m. When the thickness is 1 ⁇ m or more, the shield film can be more sufficiently supported and the metal layer can be protected. When the thickness is 20 ⁇ m or less, the transparency and flexibility are excellent, and economically advantageous. In addition, when the said resin layer is a multilayer structure, the thickness of the said resin layer is the total thickness of all the layers.
  • Examples of the inorganic substance forming the second inorganic layer include those exemplified and explained as the inorganic substance forming the first inorganic layer. Only one kind of the inorganic substance may be used, or two or more kinds thereof may be used.
  • inorganic oxides are preferable, and metal oxides are more preferable, and titanium oxide, chromium oxide, and zirconium oxide are more preferable from the viewpoint of superior environmental resistance and economic efficiency.
  • Examples of methods for forming the second inorganic layer include electrolysis, deposition (eg, vacuum deposition), sputtering, CVD, metal organic (MO), plating, and rolling. Among them, an inorganic layer formed by vapor deposition, plating, or sputtering is preferable from the viewpoint of ease of manufacture.
  • the thickness of the second inorganic layer is 0.1 to 100 nm, preferably 0.1 to 20 nm, more preferably 0.1 to 10 nm, still more preferably 0.1 to 5 nm, particularly preferably 0.1 ⁇ 2.2 nm.
  • the thickness is 0.1 nm or more, the environmental resistance is excellent.
  • the thickness is 100 nm or less, the connection stability to the outside is excellent.
  • the thickness of the second inorganic layer is the total thickness of all layers.
  • the shield film of the present invention may have a separator (release film) on the side of the conductive adhesive layer.
  • the separator is laminated so as to be peelable from the shield film of the present invention.
  • a separator is an element for covering and protecting the conductive adhesive layer, and is peeled off when using the shield film of the present invention.
  • separator examples include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, plastic film and paper surface-coated with a release agent such as a fluorine-based release agent and a long-chain alkyl acrylate release agent. .
  • PET polyethylene terephthalate
  • a release agent such as a fluorine-based release agent and a long-chain alkyl acrylate release agent.
  • the thickness of the separator is preferably 10-200 ⁇ m, more preferably 15-150 ⁇ m. When the thickness is 10 ⁇ m or more, the protective performance is excellent. When the thickness is 200 ⁇ m or less, the separator is easily peeled off during use.
  • the shielding film of the present invention may have layers other than the layers described above.
  • the other layers include other insulating layers, antireflection layers, antiglare layers, antifouling layers, hard coat layers, ultraviolet absorption layers, anti-Newton ring layers, and the like.
  • the shielding film of the present invention can be easily adhered to an adherend, yet has excellent adhesion to the adherend, excellent electrical connection stability, and excellent environmental resistance. Therefore, the electromagnetic wave shielding film of the present invention can be used even for substrates having poor resistance to high temperatures and high pressures. Moreover, it can be used in an environment where environmental resistance is required.
  • the shielding film of the present invention is preferably used for printed wiring boards, and particularly preferably for flexible printed wiring boards (FPC).
  • FPC flexible printed wiring boards
  • the shielding film of the present invention has excellent environmental resistance. Therefore, it can be preferably used in a high-temperature and high-humidity environment, for example, inside a vehicle such as an automobile.
  • FIG. 1 Manufacturing method of electromagnetic wave shielding film
  • the metal layer 3 is formed on the insulating protective layer 2 . Formation of the metal layer 3 can be performed by the various methods described above.
  • the insulating protective layer 2 can be formed by forming the second inorganic layer 22 on the resin layer 21 by vacuum deposition, sputtering, or the like.
  • a metal layer 3 is formed on the insulating protective layer 2 by vacuum deposition, sputtering, plating, or the like.
  • the first inorganic layer 4 can be formed on the surface of the formed metal layer 3 by vacuum deposition, sputtering, or the like.
  • the adhesive composition for forming the conductive adhesive layer 5 is applied (coated) to the surface of the formed first inorganic layer 4, and if necessary, the solvent is removed and / or partially cured. can be formed.
  • the adhesive composition contains, for example, a solvent (solvent) in addition to the components contained in the conductive adhesive layer.
  • the solvent include those exemplified as solvents that can be contained in the composition for forming the insulating protective layer.
  • the solid content concentration of the adhesive composition is appropriately set according to the thickness of the conductive adhesive layer to be formed.
  • a known coating method may be used to apply each of the above compositions.
  • coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, lip coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters, direct coaters and slot die coaters may be used.
  • a printed wiring board can be produced using the shielding film of the present invention. For example, by bonding the conductive adhesive layer of the shield film of the present invention to a printed wiring board (for example, a coverlay), a shield printed wiring board in which the shield film of the present invention is bonded to the printed wiring board can be obtained. can.
  • the conductive adhesive layer may be thermoset.
  • Example 1 A TiO 2 film (thickness: 2 nm) was formed as a second inorganic layer by sputtering on the surface of a PET film (thickness: 6 ⁇ m), which was a resin layer, to prepare an insulating protective layer. Next, a silver thin film (10 nm thick) was formed as a metal layer on the surface of the TiO 2 film by vacuum deposition. Next, a TiO 2 film (thickness: 1.5 nm) was formed on the surface of the silver thin film by sputtering as a first inorganic layer.
  • thermoplastic acrylic resin 95 parts by mass of thermoplastic acrylic resin, 5 parts by mass of silver-coated copper powder (spherical, median diameter 5 ⁇ m), and 400 parts by mass of toluene (solid content: 20% by mass) are blended.
  • the adhesive composition obtained by mixing is applied to the surface of a polyester film whose surface has been subjected to release treatment using a wire bar, and is heated at 100° C. for 3 minutes to form a conductive adhesive layer (thickness: 5 ⁇ m). was formed and attached to the TiO 2 film side as the first inorganic layer. As described above, the shield film of Example 1 was produced.
  • Examples 2-4 An electromagnetic wave shielding film of each example was produced in the same manner as in Example 1, except that the thickness of the first inorganic layer was changed as shown in Table 1.
  • Example 5 The epoxy resin composition was applied to a PET film substrate whose surface had been subjected to mold release treatment, and cured by heating at 100° C. for 3 minutes to form a resin layer of epoxy resin having a thickness of 5 ⁇ m. Chromium oxide (thickness: 0.2 nm) was formed by plating on both side surfaces of a rolled copper foil having a thickness of 6 ⁇ m to obtain a laminate consisting of the second inorganic layer/metal layer/first inorganic layer. Next, the second inorganic layer surface of the laminate was attached to the surface of the resin layer by heat lamination.
  • Chromium oxide thickness: 0.2 nm
  • thermoplastic acrylic resin as a conductive adhesive layer
  • nickel particles filament shape, median diameter 20 ⁇ m
  • toluene solid content is 20% by mass
  • Examples 6-8 An electromagnetic wave shielding film of each example was prepared in the same manner as in Example 5 except that the thickness of the first inorganic layer, the thickness of the second inorganic layer, and the type of conductive particles were changed as shown in Table 1. made.
  • Comparative example 1 An electromagnetic wave shielding film of Comparative Example 1 was produced in the same manner as in Example 1, except that the metal layer and the conductive adhesive layer were directly bonded together without producing the first inorganic layer.
  • Comparative example 2 An electromagnetic wave shielding film of Comparative Example 2 was produced in the same manner as in Example 3, except that the thickness of the first inorganic layer was 150 nm.
  • Comparative example 3 An electromagnetic wave shielding film of Comparative Example 3 was produced in the same manner as in Example 3, except that the thickness of the conductive adhesive layer was 1 ⁇ m, the silver-coated copper powder was spherical, and the median diameter was 7 ⁇ m.
  • Comparative example 4 An electromagnetic wave shielding film of Comparative Example 4 was produced in the same manner as in Example 3, except that instead of the silver-coated copper powder of Example 1, spherical silver-coated copper powder having a median diameter of 1 ⁇ m was used.
  • connection resistance value measurement Two electrodes each having a width of 5 mm and a length of 10 mm were placed on a glass epoxy substrate having a thickness of 2 mm with a spacing of 100 mm. Then, the shielding film obtained in the example was punched out on the electrode arrangement surface to a width of 5 mm and a length of 130 mm, and under normal temperature and pressure conditions, a 2 kg roller was reciprocated once to connect the electrodes to conductive adhesion. The agent layer surfaces were pasted together. After laminating the conductive adhesive layer surfaces, the resistance value between the two electrodes was measured using a 4-terminal method tester (trade name "RM3542", manufactured by Hioki Electric Co., Ltd.) immediately after the electromagnetic shielding film was produced and at 65 ° C. Each was measured after storage for 72 hours in an environment of 90% RH.
  • the shielding films of the present invention have low connection resistance values and excellent shielding performance even when laminated under mild conditions that are not high temperature and high pressure conditions.
  • the environmental resistance was poor (Comparative Example 1)
  • the first inorganic layer was too thick, the connection stability was poor (Comparative Example 2).
  • the ratio of the thickness of the conductive adhesive layer to the median diameter of the conductive particles is too small, the adhesiveness cannot be exhibited, resulting in the resistance value being unmeasurable (Comparative Example 3).
  • the connection stability was poor (Comparative Example 4).
  • the electromagnetic wave shielding film of the present invention can be suitably used for printed wiring boards.

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Abstract

Provided is an electromagnetic wave shield film which can be easily bonded to an adherend, has excellent adhesion properties and electrical connection stability, and also has excellent environmental resistance. An electromagnetic wave shield film 1 obtained by layering a metal layer 3, a first inorganic layer 4 and a conductive adhesive layer 5 in this order, wherein the thickness of the first inorganic layer 4 is 0.1-100nm, the conductive adhesive layer 5 contains a binder component and conductive particles, and the ratio of the thickness of the conductive adhesive layer 5 to the median diameter of the conductive particles is 0.2-3.5.

Description

電磁波シールドフィルムelectromagnetic wave shielding film
　本発明は、電磁波シールドフィルムに関する。より詳細には、本発明は、プリント配線板に使用される電磁波シールドフィルムに関する。 The present invention relates to an electromagnetic wave shielding film. More particularly, the present invention relates to electromagnetic wave shielding films used in printed wiring boards.
　プリント配線板は、携帯電話、ビデオカメラ、ノートパソコンなどの電子機器において、機構の中に回路を組み込むために多用されている。また、プリンタヘッドのような可動部と制御部との接続にも利用されている。これらの電子機器では、電磁波シールド対策が必須となっており、装置内で使用されるプリント配線板においても、電磁波シールド対策を施したシールドプリント配線板が用いられている。 Printed wiring boards are often used to incorporate circuits into the mechanisms of electronic devices such as mobile phones, video cameras, and laptop computers. It is also used to connect a movable part such as a printer head and a control part. These electronic devices require measures to shield against electromagnetic waves, and the printed wiring boards used in the devices also use shield printed wiring boards that take measures to shield against electromagnetic waves.
　シールドプリント配線板には、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）が使用される。例えば、プリント配線板に接着して使用されるシールドフィルムは、金属層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。 An electromagnetic wave shielding film (hereinafter sometimes simply referred to as "shielding film") is used for the shield printed wiring board. For example, a shield film that is used by adhering to a printed wiring board has a shield layer such as a metal layer and a conductive adhesive sheet provided on the surface of the shield layer.
　導電性接着シートを有するシールドフィルムとしては、例えば、特許文献１および２に開示のものが知られている。上記シールドフィルムは、導電性接着シートが露出した表面が、プリント配線板表面、具体的にはプリント配線板の表面に設けられたカバーレイ表面と貼着するように貼り合わせて使用される。これらの導電性接着シートは、通常、高温・高圧条件下で熱圧着してプリント配線板に接着および積層される。このようにしてプリント配線板上に配置されたシールドフィルムは、プリント配線板の外部からの電磁波を遮蔽する性能（シールド性能）を発揮する。 As a shield film having a conductive adhesive sheet, for example, those disclosed in Patent Documents 1 and 2 are known. The above-mentioned shield film is used by laminating such that the surface where the conductive adhesive sheet is exposed is adhered to the surface of the printed wiring board, specifically the surface of the coverlay provided on the surface of the printed wiring board. These conductive adhesive sheets are usually adhered and laminated on a printed wiring board by thermocompression bonding under high temperature and high pressure conditions. The shielding film arranged on the printed wiring board in this way exhibits the performance (shielding performance) of shielding electromagnetic waves from the outside of the printed wiring board.
特開２０１５－１１０７６９号公報JP 2015-110769 A 特開２０１２－２８３３４号公報JP 2012-28334 A
　従来、シールドフィルムは高温・高圧条件下で基板に貼り合わせて使用される。しかしながら、貼り合わせられる基板の種類によっては、高温・高圧条件に付すことができない場合がある。このため、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シールドフィルムが求められる傾向がある。しかしながら、従来のシールドフィルムは、比較的緩やかな条件で基板に貼り合わせた場合、密着強度や電気的接続の安定性に劣るという問題があった。 　Conventionally, the shield film is used by bonding it to the substrate under high temperature and high pressure conditions. However, depending on the type of substrates to be bonded together, there are cases where high temperature and high pressure conditions cannot be applied. For this reason, there is a tendency to demand a shielding film that can be adhered to a printed wiring board under relatively gentle conditions rather than under high temperature and high pressure conditions. However, conventional shielding films have the problem of being inferior in adhesion strength and electrical connection stability when bonded to a substrate under relatively mild conditions.
　また、近年、従来のシールドフィルムは、高温高湿環境において金属層が劣化してシールド性能が低下する、すなわち、耐環境性に劣るという問題があった。 Also, in recent years, conventional shielding films have had the problem that the metal layer deteriorates in a high-temperature, high-humidity environment and the shielding performance deteriorates, that is, the environmental resistance is poor.
　本発明は上記に鑑みてなされたものであり、本発明の目的は、簡易に被着体に接着可能であり且つ密着性および電気的接続安定性に優れ、耐環境性に優れる電磁波シールドフィルムを提供することにある。 The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetic wave shielding film that can be easily adhered to an adherend, has excellent adhesion and electrical connection stability, and has excellent environmental resistance. to provide.
　本発明者らは、上記目的を達成するため鋭意検討した結果、特定の層構成を有する電磁波シールドフィルムによれば、簡易に被着体に接着可能であり且つ密着性および電気的接続安定性に優れ、耐環境性に優れることを見出した。本発明はこれらの知見に基づいて完成させたものである。 As a result of intensive studies to achieve the above object, the present inventors have found that an electromagnetic wave shielding film having a specific layer structure can be easily adhered to an adherend and has excellent adhesion and electrical connection stability. It was found to be excellent in environmental resistance. The present invention has been completed based on these findings.
　すなわち、本発明は、金属層、第１無機層、および導電性接着剤層がこの順に積層されており、
　上記第１無機層の厚さは０．１～１００ｎｍであり、
　上記導電性接着剤層は、バインダー成分および導電性粒子を含み、
　上記導電性粒子のメディアン径に対する上記導電性接着剤層の厚さの比は０．２～３．５である、電磁波シールドフィルムを提供する。 That is, in the present invention, a metal layer, a first inorganic layer, and a conductive adhesive layer are laminated in this order,
The thickness of the first inorganic layer is 0.1 to 100 nm,
The conductive adhesive layer contains a binder component and conductive particles,
Provided is an electromagnetic wave shielding film, wherein the ratio of the thickness of the conductive adhesive layer to the median diameter of the conductive particles is 0.2 to 3.5.
　上記金属層における、上記第１無機層とは反対側の表面に絶縁保護層が直接積層されていることが好ましい。 It is preferable that an insulating protective layer is directly laminated on the surface of the metal layer opposite to the first inorganic layer.
　上記絶縁保護層として上記金属層と直接積層した第２無機層を有することが好ましい。 It is preferable to have a second inorganic layer directly laminated with the metal layer as the insulating protective layer.
　上記第２無機層の厚さは０．１～１００ｎｍであることが好ましい。 The thickness of the second inorganic layer is preferably 0.1 to 100 nm.
　上記第２無機層は金属酸化物から構成されることが好ましい。 The second inorganic layer is preferably made of metal oxide.
　上記絶縁保護層として樹脂層を有することが好ましい。 It is preferable to have a resin layer as the insulating protective layer.
　上記第１無機層は金属酸化物から構成されることが好ましい。 The first inorganic layer is preferably made of metal oxide.
　上記第１無機層は上記金属層と直接積層していることが好ましい。 The first inorganic layer is preferably laminated directly with the metal layer.
　上記導電性接着剤層は上記第１無機層と直接積層していることが好ましい。 The conductive adhesive layer is preferably laminated directly with the first inorganic layer.
　また、本発明は、上記電磁波シールドフィルムを備えたシールドプリント配線板を提供する。 The present invention also provides a shield printed wiring board comprising the electromagnetic wave shielding film.
　本発明の電磁波シールドフィルムは、簡易に被着体に接着可能であり、それでいて被着体に対する密着性に優れ、電気的接続安定性に優れ、耐環境性にも優れる。このため、本発明の電磁波シールドフィルムは、高温・高圧に対する耐性に劣る基板に対しても使用することができる。また、耐環境性が求められる環境下においても使用することができる。 The electromagnetic wave shielding film of the present invention can be easily adhered to an adherend, yet has excellent adhesion to the adherend, excellent electrical connection stability, and excellent environmental resistance. Therefore, the electromagnetic wave shielding film of the present invention can be used even for substrates having poor resistance to high temperatures and high pressures. Moreover, it can be used in an environment where environmental resistance is required.
本発明の電磁波シールドフィルムの一実施形態を示す断面模式図である。BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows one Embodiment of the electromagnetic wave shielding film of this invention. 本発明の電磁波シールドフィルムの他の実施形態を示す断面模式図である。It is a cross-sectional schematic diagram which shows other embodiment of the electromagnetic wave shielding film of this invention.
［シールドフィルム］
　本発明の電磁波シールドフィルム（シールドフィルム）は、金属層、第１無機層、および導電性接着剤層がこの順に積層された層構成を有する。 [Shielding film]
The electromagnetic wave shielding film (shielding film) of the present invention has a layer structure in which a metal layer, a first inorganic layer, and a conductive adhesive layer are laminated in this order.
　上記金属層の上記導電性接着剤層を備える側の面をより充分に保護し、耐環境性により優れる観点から、上記第１無機層は上記金属層と直接積層していることが好ましい。また、比較的緩やかな条件でプリント配線板に接着した場合であっても接続安定性に優れることとする観点から、上記導電性接着剤層は上記第１無機層と直接積層していることが好ましい。 From the viewpoint of more sufficiently protecting the surface of the metal layer on which the conductive adhesive layer is provided and having better environmental resistance, it is preferable that the first inorganic layer is directly laminated with the metal layer. In addition, from the viewpoint of excellent connection stability even when adhered to a printed wiring board under relatively mild conditions, the conductive adhesive layer is preferably laminated directly with the first inorganic layer. preferable.
　また、上記金属層の上記導電性接着剤層を備える側とは反対側の面を充分に保護し、耐環境性により優れる観点から、上記金属層における、上記第１無機層とは反対側の面に絶縁保護層を備えることが好ましい。上記絶縁保護層は上記金属層と直接積層していることが好ましい。 In addition, from the viewpoint of sufficiently protecting the surface of the metal layer opposite to the side provided with the conductive adhesive layer and improving environmental resistance, the metal layer on the side opposite to the first inorganic layer It is preferable to provide an insulating protective layer on the surface. It is preferable that the insulating protective layer is directly laminated on the metal layer.
　本発明のシールドフィルムの一実施形態について、以下に説明する。図１は、本発明のシールドフィルムの一実施形態を示す断面模式図である。図１に示すシールドフィルム１は、絶縁保護層２と、金属層３と、第１無機層４と、導電性接着剤層５とをこの順に有する。シールドフィルム１において、絶縁保護層２、金属層３、第１無機層４、および導電性接着剤層５は、それぞれ、隣接する層とは互いに直接積層している。 An embodiment of the shielding film of the present invention will be described below. FIG. 1 is a schematic cross-sectional view showing one embodiment of the shielding film of the present invention. The shield film 1 shown in FIG. 1 has an insulating protective layer 2, a metal layer 3, a first inorganic layer 4, and a conductive adhesive layer 5 in this order. In the shield film 1, the insulating protective layer 2, the metal layer 3, the first inorganic layer 4, and the conductive adhesive layer 5 are directly laminated to adjacent layers.
（導電性接着剤層）
　上記導電性接着剤層は、例えば本発明のシールドフィルムをプリント配線板に接着するための接着性や接着性と、上記金属層と電気的接続するための導電性を有する。また、上記金属層とともにシールド性能を発揮するシールド層としても機能し得る。上記導電性接着剤層は、単層であってもよく、複層であってもよい。 (Conductive adhesive layer)
The conductive adhesive layer has, for example, adhesiveness and adhesiveness for adhering the shield film of the present invention to a printed wiring board, and electrical conductivity for electrically connecting with the metal layer. In addition, it can function as a shield layer exhibiting shielding performance together with the metal layer. The conductive adhesive layer may be a single layer or multiple layers.
　上記導電性接着剤層は、バインダー成分および導電性粒子を含有する。 The conductive adhesive layer contains a binder component and conductive particles.
　上記バインダー成分としては、熱可塑性樹脂、熱硬化型樹脂、活性エネルギー線硬化型化合物などが挙げられる。上記バインダー成分は、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 binder component include thermoplastic resins, thermosetting resins, and active energy ray-curable compounds. Only one type of the binder component may be used, or two or more types may be used.
　上記熱可塑性樹脂としては、ポリスチレン系樹脂、酢酸ビニル系樹脂、ポリエステル系樹脂、ポリオレフィン系樹脂（ポリエチレン系樹脂、ポリプロピレン系樹脂等）、ポリアミド系樹脂、ゴム系樹脂、アクリル系樹脂、シリコーン系樹脂などが挙げられる。上記熱可塑性樹脂は、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 thermoplastic resin include polystyrene-based resin, vinyl acetate-based resin, polyester-based resin, polyolefin-based resin (polyethylene-based resin, polypropylene-based resin, etc.), polyamide-based resin, rubber-based resin, acrylic-based resin, silicone-based resin, etc. is mentioned. Only one type of the thermoplastic resin may be used, or two or more types may be used.
　上記熱硬化型樹脂としては、熱硬化性を有する樹脂（熱硬化性樹脂）および上記熱硬化性樹脂を硬化して得られる樹脂の両方が挙げられる。上記熱硬化性樹脂としては、例えば、フェノール系樹脂、エポキシ系樹脂、ウレタン系樹脂、メラミン系樹脂、アルキド系樹脂、アクリル系樹脂などが挙げられる。上記熱硬化型樹脂は、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 thermosetting resin include both resins having thermosetting properties (thermosetting resins) and resins obtained by curing the above thermosetting resins. Examples of the thermosetting resin include phenol-based resins, epoxy-based resins, urethane-based resins, melamine-based resins, alkyd-based resins, acrylic-based resins, and the like. Only one kind of the thermosetting resin may be used, or two or more kinds thereof may be used.
　上記エポキシ系樹脂としては、例えば、ビスフェノール型エポキシ系樹脂、スピロ環型エポキシ系樹脂、ナフタレン型エポキシ系樹脂、ビフェニル型エポキシ系樹脂、テルペン型エポキシ系樹脂、グリシジルエーテル型エポキシ系樹脂、グリシジルアミン型エポキシ系樹脂、ノボラック型エポキシ系樹脂などが挙げられる。 Examples of the epoxy resin include bisphenol type epoxy resin, spirocyclic epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, terpene type epoxy resin, glycidyl ether type epoxy resin, glycidyl amine type Epoxy-based resins, novolak-type epoxy-based resins, and the like are included.
　上記ビスフェノール型エポキシ系樹脂としては、例えば、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビスフェノールＳ型エポキシ樹脂、テトラブロムビスフェノールＡ型エポキシ樹脂などが挙げられる。上記グリシジルエーテル型エポキシ系樹脂としては、例えば、トリス（グリシジルオキシフェニル）メタン、テトラキス（グリシジルオキシフェニル）エタンなどが挙げられる。上記グリシジルアミン型エポキシ系樹脂としては、例えばテトラグリシジルジアミノジフェニルメタンなどが挙げられる。上記ノボラック型エポキシ系樹脂としては、例えば、クレゾールノボラック型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、α－ナフトールノボラック型エポキシ樹脂、臭素化フェノールノボラック型エポキシ樹脂などが挙げられる。 Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetrabromobisphenol A type epoxy resin, and the like. Examples of the glycidyl ether type epoxy resin include tris(glycidyloxyphenyl)methane and tetrakis(glycidyloxyphenyl)ethane. Examples of the glycidylamine type epoxy resin include tetraglycidyldiaminodiphenylmethane. Examples of the novolak type epoxy resin include cresol novolak type epoxy resin, phenol novolak type epoxy resin, α-naphthol novolak type epoxy resin, and brominated phenol novolak type epoxy resin.
　上記活性エネルギー線硬化型化合物は、活性エネルギー線照射により硬化し得る化合物（活性エネルギー線硬化性化合物）および上記活性エネルギー線硬化性化合物を硬化して得られる化合物の両方が挙げられる。活性エネルギー線硬化性化合物としては、特に限定されないが、例えば、分子中に１個以上（好ましくは２個以上）のラジカル反応性基（例えば、（メタ）アクリロイル基）を有する重合性化合物などが挙げられる。上記活性エネルギー線硬化型化合物は、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 active energy ray-curable compounds include both compounds that can be cured by irradiation with active energy rays (active energy ray-curable compounds) and compounds obtained by curing the active energy ray-curable compounds. The active energy ray-curable compound is not particularly limited, but for example, a polymerizable compound having one or more (preferably two or more) radical reactive groups (e.g., (meth)acryloyl groups) in the molecule. mentioned. Only 1 type may be used for the said active-energy-ray-curable compound, and 2 or more types may be used for it.
　上記バインダー成分としては、中でも、熱可塑性樹脂が好ましい。この場合、上記導電性接着剤層は粘着性を有し、本発明のシールドフィルムをプリント配線板等の被着体に貼り合わせて使用する際、高温・高圧条件下でなくても簡便に貼り合わせることができる。 Among them, a thermoplastic resin is preferable as the binder component. In this case, the conductive adhesive layer has tackiness, and when the shield film of the present invention is used by being attached to an adherend such as a printed wiring board, it can be easily attached without being subjected to high temperature and high pressure conditions. can be matched.
　上記バインダー成分が熱硬化型樹脂を含む場合、上記バインダー成分を構成する成分として、熱硬化反応を促進するための硬化剤を含んでいてもよい。上記硬化剤は、上記熱硬化性樹脂の種類に応じて適宜選択することができる。上記硬化剤は、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。 When the binder component contains a thermosetting resin, it may contain a curing agent for accelerating the thermosetting reaction as a constituent component of the binder component. The curing agent can be appropriately selected according to the type of the thermosetting resin. Only one kind of the curing agent may be used, or two or more kinds thereof may be used.
　上記導電性粒子としては、例えば、金属粒子、金属被覆樹脂粒子、金属繊維、カーボンフィラー、カーボンナノチューブなどが挙げられる。 Examples of the conductive particles include metal particles, metal-coated resin particles, metal fibers, carbon fillers, and carbon nanotubes.
　上記金属粒子および上記金属被覆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、インジウム、錫、鉛、ビスマス、これらの２以上を含む合金などが挙げられる。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 metals constituting the coating portion of the metal particles and the metal-coated resin particles include gold, silver, copper, nickel, zinc, indium, tin, lead, bismuth, and alloys containing two or more of these. . Only one kind of the above metals may be used, or two or more kinds thereof may be used.
　上記金属粒子としては、具体的には、例えば、銅粒子、銀粒子、ニッケル粒子、銀被覆銅粒子、インジウム粒子、錫粒子、鉛粒子、ビスマス粒子、金被覆銅粒子、銀被覆ニッケル粒子、金被覆ニッケル粒子、インジウム被覆銅粒子、錫被覆銅粒子、鉛被覆銅粒子、ビスマス被覆銅粒子、インジウム被覆ニッケル粒子、錫被覆ニッケル粒子、ビスマス被覆ニッケル粒子、銀被覆合金粒子などが挙げられる。上記銀被覆合金粒子としては、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被覆銅合金粒子などが挙げられる。上記金属粒子は、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, indium particles, tin particles, lead particles, bismuth particles, gold-coated copper particles, silver-coated nickel particles, gold coated nickel particles, indium-coated copper particles, tin-coated copper particles, lead-coated copper particles, bismuth-coated copper particles, indium-coated nickel particles, tin-coated nickel particles, bismuth-coated nickel particles, silver-coated alloy particles, and the like. 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. The metal particles can be produced by an electrolysis method, an atomization method, a reduction method, or the like.
　上記金属粒子としては、中でも、銀粒子、銀被覆銅粒子、銀被覆銅合金粒子、ニッケル粒子、銀被覆ニッケル粒子が好ましい。導電性に優れ、金属粒子の酸化および凝集を抑制し、且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、銀被覆銅粒子、銀被覆銅合金粒子が好ましい。 Among the metal particles, silver particles, silver-coated copper particles, silver-coated copper alloy particles, nickel particles, and silver-coated nickel particles are preferable. Silver-coated copper particles and silver-coated copper alloy particles are particularly preferred from the viewpoints of excellent conductivity, suppression of oxidation and agglomeration of the metal particles, and reduction in the cost of the metal particles.
　上記金属被覆樹脂粒子としては、具体的には、銀被覆樹脂粒子、金被覆樹脂粒子、インジウム被覆樹脂粒子、錫被覆樹脂粒子、鉛被覆樹脂粒子、ビスマス被覆樹脂粒子などが挙げられる。 Specific examples of the metal-coated resin particles include silver-coated resin particles, gold-coated resin particles, indium-coated resin particles, tin-coated resin particles, lead-coated resin particles, and bismuth-coated resin particles.
　上記導電性粒子の形状としては、球状、フレーク状（鱗片状）、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）、スパイク状などが挙げられる。 Examples of the shape of the conductive particles include spherical, flake-like (scale-like), dendritic (dendrite-like), fibrous (filament-like), amorphous (polyhedral), and spike-like shapes.
　上記導電性粒子のメディアン径（Ｄ５０）は、１～５０μｍであることが好ましく、より好ましくは３～４０μｍである。上記メディアン径が１μｍ以上であると、導電性粒子の分散性が良好で凝集が抑制できる。上記平均粒径が５０μｍ以下であると、導電性が良好となる。上記メディアン径は、上記導電性接着剤層中の全ての導電性粒子のメディアン径であり、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％での粒径をいうものとする。上記メディアン径が上記範囲内であると、接続安定性により優れる。上記メディアン径は、例えば、レーザー回折式粒子径分布測定装置（商品名「ＳＡＬＤ－２２００」、株式会社島津製作所製）により測定することができる。 The median diameter (D50) of the conductive particles is preferably 1-50 μm, more preferably 3-40 μm. When the median diameter is 1 μm or more, the dispersibility of the conductive particles is good and aggregation can be suppressed. When the average particle size is 50 µm or less, the conductivity becomes good. The median diameter is the median diameter of all the conductive particles in the conductive adhesive layer, and refers to the particle size at 50% of the integrated value in the particle size distribution determined by the laser diffraction/scattering method. When the median diameter is within the above range, the connection stability is more excellent. The median diameter can be measured, for example, with a laser diffraction particle size distribution analyzer (trade name “SALD-2200”, manufactured by Shimadzu Corporation).
　上記導電性接着剤層は、用途に必要に応じて等方導電性または異方導電性を有する層とすることができる。 The conductive adhesive layer can be a layer having isotropic conductivity or anisotropic conductivity depending on the application.
　上記導電性接着剤層における上記導電性粒子の含有割合は、導電性接着剤層の総量１００質量％に対して、３～９５質量％であることが好ましく、より好ましくは５～９０質量％である。等方導電性の導電性接着剤層とする場合には４０～９５質量％とすることができる。異方導電性の導電性接着剤層とする場合には３～４０質量％とすることができる。 The content of the conductive particles in the conductive adhesive layer is preferably 3 to 95% by mass, more preferably 5 to 90% by mass, with respect to 100% by mass of the total amount of the conductive adhesive layer. be. In the case of forming an isotropically conductive conductive adhesive layer, it can be 40 to 95% by mass. In the case of forming an anisotropically conductive conductive adhesive layer, it can be 3 to 40% by mass.
　上記導電性接着剤層は、本発明の効果を損なわない範囲内において、上述の各成分以外のその他の成分を含有していてもよい。上記その他の成分としては、公知乃至慣用の接着剤層に含まれる成分が挙げられる。上記その他の成分としては、例えば、硬化促進剤、可塑剤、難燃剤、消泡剤、粘度調整剤、酸化防止剤、希釈剤、沈降防止剤、充填剤、レベリング剤、カップリング剤、紫外線吸収剤、粘着付与樹脂、ブロッキング防止剤などが挙げられる。上記その他の成分は、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 conductive adhesive layer may contain components other than the components described above within a range that does not impair the effects of the present invention. Examples of the above-mentioned other components include components contained in known or commonly used adhesive layers. Examples of the above other components include curing accelerators, plasticizers, flame retardants, defoaming agents, viscosity modifiers, antioxidants, diluents, anti-settling agents, fillers, leveling agents, coupling agents, and UV absorbers. agents, tackifying resins, antiblocking agents, and the like. Only one kind of the other components may be used, or two or more kinds thereof may be used.
　上記導電性接着剤層の厚さは、特に限定されないが、３～２０μｍであることが好ましく、より好ましくは５～１８μｍである。上記厚さが３μｍ以上であると、被着体に対する密着性により優れる。また、耐環境性により優れる。上記厚さが２０μｍ以下であると、比較的緩やかな条件でプリント配線板に接着した場合であっても接続安定性により優れる。 Although the thickness of the conductive adhesive layer is not particularly limited, it is preferably 3-20 μm, more preferably 5-18 μm. When the thickness is 3 μm or more, the adhesiveness to the adherend is more excellent. Moreover, it is superior in environmental resistance. When the thickness is 20 μm or less, the connection stability is excellent even when adhered to a printed wiring board under relatively mild conditions.
　上記導電性粒子のＤ５０に対する上記導電性接着剤層の厚さの比［接着剤層厚さ／Ｄ５０］は、０．２～３．５であり、好ましくは０．３～３．０である。上記比が０．２以上であることにより、プリント配線板等の被着体に対する密着性がより良好となる。上記比が３．５以下であることにより、導電性接着剤層表面から露出する導電性粒子の量が多くなり、比較的緩やかな条件でプリント配線板に接着した場合であっても接続安定性により優れる。 The ratio of the thickness of the conductive adhesive layer to the D50 of the conductive particles [adhesive layer thickness/D50] is 0.2 to 3.5, preferably 0.3 to 3.0. . When the above ratio is 0.2 or more, the adhesion to adherends such as printed wiring boards becomes better. When the above ratio is 3.5 or less, the amount of conductive particles exposed from the surface of the conductive adhesive layer is increased, and connection stability is ensured even when adhered to a printed wiring board under relatively mild conditions. better than
（第１無機層）
　上記第１無機層は、上記金属層を保護する層である。上記第１無機層が上記金属層と上記導電性接着剤層との間に介在することにより、上記金属層の上記導電性接着剤層を備える側の面を保護し、高温高湿環境において上記金属層が劣化して接続安定性が低下するのを抑制することができ、すなわち、耐環境性に優れる。上記接続安定性の低下は、上記導電性接着剤層中の水分等により上記金属層が劣化することに起因するものと推測される。上記第１無機層は、単層であってもよく、複層であってもよい。 (First inorganic layer)
The first inorganic layer is a layer that protects the metal layer. By interposing the first inorganic layer between the metal layer and the conductive adhesive layer, the surface of the metal layer on the side provided with the conductive adhesive layer is protected, and in a high-temperature and high-humidity environment, the above-mentioned It is possible to suppress deterioration of the connection stability due to deterioration of the metal layer, that is, excellent environmental resistance. It is presumed that the deterioration of the connection stability is caused by the deterioration of the metal layer due to the moisture or the like in the conductive adhesive layer. The first inorganic layer may be a single layer or multiple layers.
　上記第１無機層を構成する無機物としては、例えば、金属酸化物、その他の無機酸化物などが挙げられる。上記無機物は、一種のみを使用してもよく、二種以上を使用してもよい。 Examples of inorganic substances that constitute the first inorganic layer include metal oxides and other inorganic oxides. Only one kind of the inorganic substance may be used, or two or more kinds thereof may be used.
　上記無機酸化物としては、例えば、酸化アルミニウム（アルミナ）、酸化マグネシウム、酸化アンチモン、酸化チタン、酸化クロム、酸化ジルコニウム、酸化亜鉛、酸化ニッケル、酸化パラジウム、酸化タングステン、酸化インジウム、ＩＴＯ（Ｉｎｄｉｕｍ　Ｔｉｎ　Ｏｘｉｄｅ；酸化インジウム・スズ）等の金属酸化物や酸化ケイ素などが挙げられる。また、上記アルカリ土類金属塩としては、例えば、フッ化マグネシウム、フッ化カルシウムなどのフッ化物塩などが挙げられる。また、アルカリ土類金属塩以外の金属塩としては、例えば、ケイ酸アルミニウム、水酸化アルミニウム、硫化亜鉛などが挙げられる。 Examples of the inorganic oxide include aluminum oxide (alumina), magnesium oxide, antimony oxide, titanium oxide, chromium oxide, zirconium oxide, zinc oxide, nickel oxide, palladium oxide, tungsten oxide, indium oxide, and ITO (Indium Tin Oxide). ; indium tin oxide) and silicon oxide. Examples of the alkaline earth metal salt include fluoride salts such as magnesium fluoride and calcium fluoride. Examples of metal salts other than alkaline earth metal salts include aluminum silicate, aluminum hydroxide, and zinc sulfide.
　上記無機物としては、中でも、無機酸化物が好ましく、より好ましくは金属酸化物、耐環境性および経済性により優れる観点から、さらに好ましくは酸化チタン、酸化クロム、酸化ジルコニウムである。 Among these inorganic substances, inorganic oxides are preferable, and metal oxides are more preferable, and titanium oxide, chromium oxide, and zirconium oxide are more preferable from the viewpoint of superior environmental resistance and economic efficiency.
　上記第１無機層の形成方法としては、電解、蒸着（例えば真空蒸着）、スパッタリング、ＣＶＤ法、メタルオーガニック（ＭＯ）、メッキ、圧延加工などが挙げられる。中でも、製造容易性の観点から、蒸着、スパッタリング、またはメッキにより形成された無機層が好ましい。 Examples of methods for forming the first inorganic layer include electrolysis, vapor deposition (eg, vacuum vapor deposition), sputtering, CVD, metal organic (MO), plating, and rolling. Among them, an inorganic layer formed by vapor deposition, sputtering, or plating is preferable from the viewpoint of ease of manufacture.
　上記第１無機層の厚さは、０．１～１００ｎｍであり、好ましくは０．１～２０ｎｍ、より好ましくは０．１～１０ｎｍ、さらに好ましくは０．１～５ｎｍ、特に好ましくは０．１～２．２ｎｍである。上記厚さが０．１ｎｍ以上であることにより、耐環境性に優れる。上記厚さが１００ｎｍ以下であることにより、比較的緩やかな条件でプリント配線板に接着した場合であっても接続安定性に優れる。なお、上記第１無機層が複層構成である場合、上記第１無機層の厚さは、全ての層厚さの合計である。 The thickness of the first inorganic layer is 0.1 to 100 nm, preferably 0.1 to 20 nm, more preferably 0.1 to 10 nm, still more preferably 0.1 to 5 nm, particularly preferably 0.1 ~2.2 nm. When the thickness is 0.1 nm or more, the environmental resistance is excellent. When the thickness is 100 nm or less, the connection stability is excellent even when the adhesive is adhered to the printed wiring board under relatively mild conditions. When the first inorganic layer has a multilayer structure, the thickness of the first inorganic layer is the total thickness of all layers.
（金属層）
　上記金属層は、本発明のシールドフィルムにおいてシールド層として機能する要素である。上記金属層は、単層であってもよいし、同種または異種の積層体であってもよい。 (metal layer)
The metal layer is an element that functions as a shield layer in the shield film of the present invention. The metal layer may be a single layer or a laminate of the same or different types.
　上記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、リチウム、ニッケル、スズ、パラジウム、クロム、チタン、亜鉛、またはこれらの合金などが挙げられる。上記合金としては、例えば、銀／銅合金、マグネシウム／銅合金、マグネシウム／銀合金、マグネシウム／アルミニウム合金、マグネシウム／インジウム合金、リチウム／アルミニウム合金、ＩＴＯ（Ｉｎｄｉｕｍ　Ｔｉｎ　Ｏｘｉｄｅ；酸化インジウム・スズ）などが挙げられる。上記金属としては、中でも、電磁波シールド性能により優れる観点から、銅、銀が好ましく、耐マイグレーション性および耐硫化性により優れる観点から、銀／銅合金であることが好ましい。 Examples of metals forming the metal layer include gold, silver, copper, aluminum, lithium, nickel, tin, palladium, chromium, titanium, zinc, and alloys thereof. Examples of the alloy include silver/copper alloy, magnesium/copper alloy, magnesium/silver alloy, magnesium/aluminum alloy, magnesium/indium alloy, lithium/aluminum alloy, ITO (Indium Tin Oxide; indium tin oxide), and the like. mentioned. Among these metals, copper and silver are preferable from the viewpoint of excellent electromagnetic wave shielding performance, and silver/copper alloy is preferable from the viewpoint of excellent migration resistance and sulfurization resistance.
　上記金属層の形成方法は特に限定されず、例えば、電解、蒸着（例えば真空蒸着）、スパッタリング、ＣＶＤ法、メタルオーガニック（ＭＯ）、メッキ、圧延加工などが挙げられる。中でも、製造容易性の観点から、蒸着、メッキ、またはスパッタリングにより形成された金属層が好ましい。 The method of forming the metal layer is not particularly limited, and examples include electrolysis, vapor deposition (eg, vacuum vapor deposition), sputtering, CVD, metal organic (MO), plating, and rolling. Among them, a metal layer formed by vapor deposition, plating, or sputtering is preferable from the viewpoint of ease of manufacture.
　上記金属層の厚さは、特に限定されないが、例えば５ｎｍ～１５μｍであり、好ましくは５ｎｍ～１３μｍである。上記金属層が複層構成である場合、上記金属層の厚さは、全ての層厚さの合計である。 Although the thickness of the metal layer is not particularly limited, it is, for example, 5 nm to 15 μm, preferably 5 nm to 13 μm. When the metal layer has a multi-layer structure, the thickness of the metal layer is the sum of all layer thicknesses.
（絶縁保護層）
　上記絶縁保護層は、絶縁性を有し、且つ本発明のシールドフィルムにおける内部の各層を保護する。上記絶縁保護層を備えると、上記金属層の上記第１無機層が備えられていない側の面における耐環境性を向上させ、接続安定性の低下をより抑制することができる。上記絶縁保護層は、単層であってもよく、複層であってもよい。 (insulating protective layer)
The insulating protective layer has insulating properties and protects the inner layers of the shield film of the present invention. By providing the insulating protective layer, it is possible to improve the environmental resistance of the surface of the metal layer on which the first inorganic layer is not provided, and to further suppress the deterioration of the connection stability. The insulating protective layer may be a single layer or multiple layers.
　上記絶縁保護層は、主に樹脂から形成される樹脂層、または、無機物から形成される無機層が挙げられる。上記絶縁保護層が無機層である場合、耐環境性によりいっそう優れる。上記絶縁保護層が樹脂層である場合、本発明のシールドフィルムにおいて支持体として機能する。上記絶縁保護層は、単層であってもよいし、同種または異種の積層体であってもよい。 Examples of the insulating protective layer include a resin layer formed mainly from a resin, or an inorganic layer formed from an inorganic substance. When the insulating protective layer is an inorganic layer, the environmental resistance is further improved. When the insulating protective layer is a resin layer, it functions as a support in the shield film of the present invention. The insulating protective layer may be a single layer or a laminate of the same or different types.
　上記絶縁保護層は、樹脂層および無機層を有することが好ましい。この場合、上記無機層が上記金属層側であることが好ましい。なお、本明細書において、上記絶縁保護層に含まれ得る無機層を「第２無機層」と称する場合がある。上記第２無機層は、耐環境性により優れる観点から、上記金属層に直接積層していることが好ましい。 The insulating protective layer preferably has a resin layer and an inorganic layer. In this case, the inorganic layer is preferably on the metal layer side. In this specification, the inorganic layer that can be included in the insulating protective layer may be referred to as a "second inorganic layer". The second inorganic layer is preferably laminated directly on the metal layer from the viewpoint of better environmental resistance.
　上記絶縁保護層が樹脂層および第２無機層を備える場合の本発明のシールドフィルムの一実施形態を図２に示す。図２に示すシールドフィルム１において、絶縁保護層２は、樹脂層２１および第２無機層２２の積層構造を有し、当該積層構造から構成される。第２無機層２２は金属層３側、樹脂層２１は最表面となるように配置されており、第２無機層２２は金属層３と直接積層している。 FIG. 2 shows an embodiment of the shield film of the present invention in which the insulating protective layer comprises a resin layer and a second inorganic layer. In the shielding film 1 shown in FIG. 2, the insulating protective layer 2 has a laminate structure of a resin layer 21 and a second inorganic layer 22, and is composed of the laminate structure. The second inorganic layer 22 is arranged on the metal layer 3 side and the resin layer 21 is arranged on the outermost surface, and the second inorganic layer 22 is directly laminated on the metal layer 3 .
　上記絶縁保護層における樹脂層を構成する樹脂としては、熱可塑性樹脂、熱硬化型樹脂、活性エネルギー線化合物などが挙げられるが、耐環境性により優れる観点から、熱硬化型樹脂または活性エネルギー線硬化型化合物であることが好ましい。上記樹脂は、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 resin constituting the resin layer in the insulating protective layer include thermoplastic resins, thermosetting resins, and active energy ray compounds. It is preferably a type compound. Only one kind of the above resin may be used, or two or more kinds thereof may be used.
　上記熱可塑性樹脂としては、例えば、低密度ポリエチレン、直鎖状低密度ポリエチレン、中密度ポリエチレン、高密度ポリエチレン、超低密度ポリエチレン、ランダム共重合ポリプロピレン、ブロック共重合ポリプロピレン、ホモポリプロレン、ポリブテン、ポリメチルペンテン、エチレン－酢酸ビニル共重合体（ＥＶＡ）、アイオノマー、エチレン－（メタ）アクリル酸共重合体、エチレン－（メタ）アクリル酸エステル（ランダム、交互）共重合体、エチレン－ブテン共重合体、エチレン－ヘキセン共重合体等のポリオレフィン樹脂；ポリウレタン；ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート、ポリブチレンテレフタレート（ＰＢＴ）等のポリエステル；ポリカーボネート（ＰＣ）；ポリイミド（ＰＩ）；ポリエーテルエーテルケトン（ＰＥＥＫ）；ポリエーテルイミド；アラミド、全芳香族ポリアミド等のポリアミド；ポリアミドイミド；ポリフェニルスルフィド；ポリスルホン（ＰＳ）；ポリエーテルスルホン（ＰＥＳ）；ポリメチルメタクリレート（ＰＭＭＡ）等のアクリル樹脂；アクリロニトリル－ブタジエン－スチレン共重合体（ＡＢＳ）；フッ素樹脂；ポリ塩化ビニル；ポリ塩化ビニリデン；トリアセチルセルロース（ＴＡＣ）等のセルロース樹脂；シリコーン樹脂などが挙げられる。上記熱可塑性樹脂は、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。上記熱可塑性樹脂としては、透明性に優れる観点から、中でも、ポリエステル、セルロース樹脂が好ましく、より好ましくはポリエチレンテレフタレート、トリアセチルセルロースである。 Examples of the thermoplastic resin include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, poly Methylpentene, ethylene-vinyl acetate copolymer (EVA), ionomer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer , Polyolefin resins such as ethylene-hexene copolymer; polyurethane; polyester such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT); polycarbonate (PC); polyimide (PI); ); Polyetherimide; Aramid, polyamide such as wholly aromatic polyamide; Polyamideimide; Polyphenyl sulfide; Polysulfone (PS); Polyethersulfone (PES); styrene copolymer (ABS); fluorine resin; polyvinyl chloride; polyvinylidene chloride; cellulose resin such as triacetyl cellulose (TAC); Only one type of the thermoplastic resin may be used, or two or more types may be used. From the viewpoint of excellent transparency, the thermoplastic resin is preferably polyester or cellulose resin, and more preferably polyethylene terephthalate or triacetyl cellulose.
　上記熱硬化型樹脂としては、熱硬化性を有する樹脂（熱硬化性樹脂）および上記熱硬化性樹脂を硬化して得られる樹脂の両方が挙げられる。上記熱硬化型樹脂としては、例えば、フェノール系樹脂、エポキシ系樹脂、ウレタン系樹脂、メラミン系樹脂、アルキド系樹脂、イミド系樹脂、アミド系樹脂、ポリアミドイミド系樹脂、ポリフェニルスルフィド系樹脂、液晶ポリマー（ＬＣＰ）、アクリル系樹脂などが挙げられる。上記熱硬化型樹脂は、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 thermosetting resin include both resins having thermosetting properties (thermosetting resins) and resins obtained by curing the above thermosetting resins. Examples of the thermosetting resin include phenol-based resins, epoxy-based resins, urethane-based resins, melamine-based resins, alkyd-based resins, imide-based resins, amide-based resins, polyamideimide-based resins, polyphenylsulfide-based resins, liquid crystals, Examples include polymers (LCP) and acrylic resins. Only one kind of the thermosetting resin may be used, or two or more kinds thereof may be used.
　上記活性エネルギー線硬化型化合物は、活性エネルギー線照射により硬化し得る化合物（活性エネルギー線硬化性化合物）および上記活性エネルギー線硬化性化合物を硬化して得られる化合物の両方が挙げられる。活性エネルギー線硬化性化合物としては、特に限定されないが、例えば、分子中に１個以上（好ましくは２個以上）のラジカル反応性基（例えば、（メタ）アクリロイル基）を有する重合性化合物などが挙げられる。上記活性エネルギー線硬化型化合物は、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 active energy ray-curable compounds include both compounds that can be cured by irradiation with active energy rays (active energy ray-curable compounds) and compounds obtained by curing the active energy ray-curable compounds. The active energy ray-curable compound is not particularly limited, but for example, a polymerizable compound having one or more (preferably two or more) radical reactive groups (e.g., (meth)acryloyl groups) in the molecule. mentioned. Only 1 type may be used for the said active-energy-ray-curable compound, and 2 or more types may be used for it.
　上記樹脂層の表面（特に、金属層側の表面）は、上記金属層などの隣接層との密着性、保持性等を高める目的で、例えば、コロナ放電処理、プラズマ処理、サンドマット加工処理、オゾン暴露処理、火炎暴露処理、高圧電撃暴露処理、イオン化放射線処理等の物理的処理；クロム酸処理等の化学的処理；コーティング剤（下塗り剤）による易接着処理等の表面処理が施されていてもよい。密着性を高めるための表面処理は、上記樹脂層における金属層側の表面全体に施されていることが好ましい。 The surface of the resin layer (especially the surface on the side of the metal layer) may be subjected to, for example, corona discharge treatment, plasma treatment, sand mat treatment, and the like, for the purpose of enhancing adhesion and retention with adjacent layers such as the metal layer. Physical treatment such as ozone exposure treatment, flame exposure treatment, high voltage shock exposure treatment, ionizing radiation treatment; chemical treatment such as chromic acid treatment; surface treatment such as easy adhesion treatment with coating agent (undercoat). good too. It is preferable that the surface treatment for enhancing adhesion is applied to the entire surface of the resin layer on the metal layer side.
　上記樹脂層の厚さは、特に限定されないが、１～２０μｍであることが好ましく、より好ましくは１～４μｍである。上記厚さが１μｍ以上であると、より充分にシールドフィルムを支持および金属層を保護することができる。上記厚さが２０μｍ以下であると、透明性および柔軟性に優れ、また経済的にも有利である。なお、上記樹脂層が複層構成である場合、上記樹脂層の厚さは、全ての層厚さの合計である。 Although the thickness of the resin layer is not particularly limited, it is preferably 1 to 20 μm, more preferably 1 to 4 μm. When the thickness is 1 μm or more, the shield film can be more sufficiently supported and the metal layer can be protected. When the thickness is 20 µm or less, the transparency and flexibility are excellent, and economically advantageous. In addition, when the said resin layer is a multilayer structure, the thickness of the said resin layer is the total thickness of all the layers.
　上記第２無機層を構成する無機物としては、上述の第１無機層を構成する無機物として例示および説明されたものが挙げられる。上記無機物は、一種のみを使用してもよく、二種以上を使用してもよい。 Examples of the inorganic substance forming the second inorganic layer include those exemplified and explained as the inorganic substance forming the first inorganic layer. Only one kind of the inorganic substance may be used, or two or more kinds thereof may be used.
　上記無機物としては、中でも、無機酸化物が好ましく、より好ましくは金属酸化物、耐環境性および経済性により優れる観点から、さらに好ましくは酸化チタン、酸化クロム、酸化ジルコニウムである。 Among these inorganic substances, inorganic oxides are preferable, and metal oxides are more preferable, and titanium oxide, chromium oxide, and zirconium oxide are more preferable from the viewpoint of superior environmental resistance and economic efficiency.
　上記第２無機層の形成方法としては、電解、蒸着（例えば真空蒸着）、スパッタリング、ＣＶＤ法、メタルオーガニック（ＭＯ）、メッキ、圧延加工などが挙げられる。中でも、製造容易性の観点から、蒸着、メッキ、またはスパッタリングにより形成された無機層が好ましい。 Examples of methods for forming the second inorganic layer include electrolysis, deposition (eg, vacuum deposition), sputtering, CVD, metal organic (MO), plating, and rolling. Among them, an inorganic layer formed by vapor deposition, plating, or sputtering is preferable from the viewpoint of ease of manufacture.
　上記第２無機層の厚さは、０．１～１００ｎｍであり、好ましくは０．１～２０ｎｍ、より好ましくは０．１～１０ｎｍ、さらに好ましくは０．１～５ｎｍ、特に好ましくは０．１～２．２ｎｍである。上記厚さが０．１ｎｍ以上であると、耐環境性により優れる。上記厚さが１００ｎｍ以下であると、外部への接続安定性に優れる。なお、上記第２無機層が複層構成である場合、上記第２無機層の厚さは、全ての層厚さの合計である。 The thickness of the second inorganic layer is 0.1 to 100 nm, preferably 0.1 to 20 nm, more preferably 0.1 to 10 nm, still more preferably 0.1 to 5 nm, particularly preferably 0.1 ~2.2 nm. When the thickness is 0.1 nm or more, the environmental resistance is excellent. When the thickness is 100 nm or less, the connection stability to the outside is excellent. When the second inorganic layer has a multilayer structure, the thickness of the second inorganic layer is the total thickness of all layers.
　本発明のシールドフィルムは、導電性接着剤層側にセパレータ（剥離フィルム）を有していてもよい。セパレータは、本発明のシールドフィルムから剥離可能なように積層される。セパレータは、導電性接着剤層を被覆して保護するための要素であり、本発明のシールドフィルムを使用する際には剥がされる。 The shield film of the present invention may have a separator (release film) on the side of the conductive adhesive layer. The separator is laminated so as to be peelable from the shield film of the present invention. A separator is an element for covering and protecting the conductive adhesive layer, and is peeled off when using the shield film of the present invention.
　上記セパレータとしては、例えば、ポリエチレンテレフタレート（ＰＥＴ）フィルム、ポリエチレンフィルム、ポリプロピレンフィルム、フッ素系剥離剤や長鎖アルキルアクリレート系剥離剤等の剥離剤により表面コートされたプラスチックフィルムや紙類などが挙げられる。 Examples of the separator include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, plastic film and paper surface-coated with a release agent such as a fluorine-based release agent and a long-chain alkyl acrylate release agent. .
　上記セパレータの厚さは、１０～２００μｍであることが好ましく、より好ましくは１５～１５０μｍである。上記厚さが１０μｍ以上であると、保護性能により優れる。上記厚さが２００μｍ以下であると、使用時にセパレータを剥離しやすい。 The thickness of the separator is preferably 10-200 μm, more preferably 15-150 μm. When the thickness is 10 µm or more, the protective performance is excellent. When the thickness is 200 μm or less, the separator is easily peeled off during use.
　本発明のシールドフィルムは、上述の各層以外のその他の層を有していてもよい。上記その他の層としては、例えば、その他の絶縁層、反射防止層、防眩層、防汚層、ハードコート層、紫外線吸収層、アンチニュートンリング層などが挙げられる。 The shielding film of the present invention may have layers other than the layers described above. Examples of the other layers include other insulating layers, antireflection layers, antiglare layers, antifouling layers, hard coat layers, ultraviolet absorption layers, anti-Newton ring layers, and the like.
　本発明のシールドフィルムは、簡易に被着体に接着可能であり、それでいて被着体に対する密着性に優れ、電気的接続安定性に優れ、耐環境性にも優れる。このため、本発明の電磁波シールドフィルムは、高温・高圧に対する耐性に劣る基板に対しても使用することができる。また、耐環境性が求められる環境下においても使用することができる。 The shielding film of the present invention can be easily adhered to an adherend, yet has excellent adhesion to the adherend, excellent electrical connection stability, and excellent environmental resistance. Therefore, the electromagnetic wave shielding film of the present invention can be used even for substrates having poor resistance to high temperatures and high pressures. Moreover, it can be used in an environment where environmental resistance is required.
　本発明のシールドフィルムは、プリント配線板用途であることが好ましく、フレキシブルプリント配線板（ＦＰＣ）用途であることが特に好ましい。 The shielding film of the present invention is preferably used for printed wiring boards, and particularly preferably for flexible printed wiring boards (FPC).
　また、本発明のシールドフィルムは、耐環境性に優れる。このため、高温高湿環境、例えば自動車等の車両内などにおいて好ましく使用することができる。 In addition, the shielding film of the present invention has excellent environmental resistance. Therefore, it can be preferably used in a high-temperature and high-humidity environment, for example, inside a vehicle such as an automobile.
（電磁波シールドフィルムの製造方法）
　本発明のシールドフィルムの製造方法の一実施形態について、図１および図２を用いて説明する。図１に示すシールドフィルム１の作製においては、まず、絶縁保護層２上に金属層３を形成する。金属層３の形成は、上述した各種方法により行うことができる。 (Manufacturing method of electromagnetic wave shielding film)
One embodiment of the method for manufacturing the shielding film of the present invention will be described with reference to FIGS. 1 and 2. FIG. In producing the shield film 1 shown in FIG. 1, first, the metal layer 3 is formed on the insulating protective layer 2 . Formation of the metal layer 3 can be performed by the various methods described above.
　図２に示すシールドフィルム１の作製においては、樹脂層２１上に第２無機層２２を真空蒸着やスパッタリング等によって形成し、絶縁保護層２を形成することができる。次いで、絶縁保護層２上に、真空蒸着やスパッタリング、メッキ等により金属層３を形成する。 In the production of the shield film 1 shown in FIG. 2, the insulating protective layer 2 can be formed by forming the second inorganic layer 22 on the resin layer 21 by vacuum deposition, sputtering, or the like. Next, a metal layer 3 is formed on the insulating protective layer 2 by vacuum deposition, sputtering, plating, or the like.
　次に、形成された金属層３表面に、第１無機層４を真空蒸着やスパッタリング等によって形成することができる。 Next, the first inorganic layer 4 can be formed on the surface of the formed metal layer 3 by vacuum deposition, sputtering, or the like.
　次に、形成された第１無機層４表面に、導電性接着剤層５形成用の接着剤組成物を塗布（塗工）し、必要に応じて、脱溶媒および／または一部硬化させて形成することができる。上記接着剤組成物は、例えば、上述の導電性接着剤層に含まれる各成分に加え、溶剤（溶媒）を含む。溶剤としては、上述の絶縁保護層を形成するための組成物が含み得る溶剤として例示されたものが挙げられる。上記接着剤組成物の固形分濃度は、形成する導電性接着剤層の厚さなどに応じて適宜設定される。 Next, the adhesive composition for forming the conductive adhesive layer 5 is applied (coated) to the surface of the formed first inorganic layer 4, and if necessary, the solvent is removed and / or partially cured. can be formed. The adhesive composition contains, for example, a solvent (solvent) in addition to the components contained in the conductive adhesive layer. Examples of the solvent include those exemplified as solvents that can be contained in the composition for forming the insulating protective layer. The solid content concentration of the adhesive composition is appropriately set according to the thickness of the conductive adhesive layer to be formed.
　上記各組成物の塗布には、公知のコーティング法が用いられてもよい。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が用いられてもよい。 A known coating method may be used to apply each of the above compositions. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, lip coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters, direct coaters and slot die coaters may be used.
　なお、上述した製造方法では、主に、各層を順次形成して作製する方法（ダイレクトコート法）について説明したが、このような方法に限定されず、例えば、セパレートフィルムなどの仮基材または基材上に個別に形成した各層をラミネートして順次貼り合わせる方法（ラミネート法）により作製してもよい。 In the above-described manufacturing method, a method of sequentially forming each layer (direct coating method) was mainly described, but it is not limited to such a method. It may also be produced by a method (lamination method) in which each layer separately formed on a material is laminated and successively adhered.
　本発明のシールドフィルムを用いてプリント配線板を作製することができる。例えば、本発明のシールドフィルムの導電性接着剤層をプリント配線板（例えば、カバーレイ）に貼り合わせることで、プリント配線板に本発明のシールドフィルムが貼り合わされたシールドプリント配線板を得ることができる。上記シールドプリント配線板において、上記導電性接着剤層は、熱硬化していてもよい。 A printed wiring board can be produced using the shielding film of the present invention. For example, by bonding the conductive adhesive layer of the shield film of the present invention to a printed wiring board (for example, a coverlay), a shield printed wiring board in which the shield film of the present invention is bonded to the printed wiring board can be obtained. can. In the shield printed wiring board, the conductive adhesive layer may be thermoset.
　以下に、実施例に基づいて本発明をより詳細に説明するが、本発明はこれらの実施例にのみ限定されるものではない。 The present invention will be described in more detail below based on examples, but the present invention is not limited only to these examples.
　実施例１
　樹脂層であるＰＥＴフィルム（厚さ６μｍ）の表面に、第２無機層としてスパッタリングによりＴｉＯ2膜（厚さ２ｎｍ）を形成し、絶縁保護層を作製した。次に、上記ＴｉＯ2膜表面に、金属層として真空蒸着により銀薄膜（厚さ１０ｎｍ）を形成した。次に、上記銀薄膜表面に、第１無機層としてスパッタリングによりＴｉＯ2膜（厚さ１．５ｎｍ）を形成した。そして、導電性接着剤層として熱可塑性のアクリル系樹脂９５質量部、銀コート銅粉（球状、メディアン径５μｍ）５質量部、およびトルエン４００質量部（固形分が２０質量％）を配合して混合して得られた接着剤組成物を、表面を離型処理したポリエステルフィルム表面に、ワイヤーバーを用いて塗布し、１００℃で３分加熱することで導電性接着剤層（厚さ５μｍ）を形成し、上記第１無機層であるＴｉＯ2膜側に貼り合わせた。以上のようにして、実施例１のシールドフィルムを作製した。 Example 1
A TiO 2 film (thickness: 2 nm) was formed as a second inorganic layer by sputtering on the surface of a PET film (thickness: 6 μm), which was a resin layer, to prepare an insulating protective layer. Next, a silver thin film (10 nm thick) was formed as a metal layer on the surface of the TiO 2 film by vacuum deposition. Next, a TiO 2 film (thickness: 1.5 nm) was formed on the surface of the silver thin film by sputtering as a first inorganic layer. Then, as a conductive adhesive layer, 95 parts by mass of thermoplastic acrylic resin, 5 parts by mass of silver-coated copper powder (spherical, median diameter 5 μm), and 400 parts by mass of toluene (solid content: 20% by mass) are blended. The adhesive composition obtained by mixing is applied to the surface of a polyester film whose surface has been subjected to release treatment using a wire bar, and is heated at 100° C. for 3 minutes to form a conductive adhesive layer (thickness: 5 μm). was formed and attached to the TiO 2 film side as the first inorganic layer. As described above, the shield film of Example 1 was produced.
　実施例２～４
　第１無機層の厚さを表１に示すとおりに変更したこと以外は実施例１と同様にして、各実施例の電磁波シールドフィルムを作製した。 Examples 2-4
An electromagnetic wave shielding film of each example was produced in the same manner as in Example 1, except that the thickness of the first inorganic layer was changed as shown in Table 1.
　実施例５
　エポキシ樹脂組成物を、表面に離型処理を施したＰＥＴフィルム基材に塗布し、１００℃、３分の条件で加熱硬化して厚さが５μｍのエポキシ樹脂からなる樹脂層を形成した。また、厚さ６μｍの圧延銅箔の両側表面に、メッキによって酸化クロム（厚さ０．２ｎｍ）を形成し、第２無機層／金属層／第１無機層からなる積層体を得た。次に、上記樹脂層の表面に、上記積層体の第２無機層面を加熱ラミネートにより貼り合わせた。次に、上記第１無機層の表面に、導電性接着剤層として熱可塑性のアクリル系樹脂９５質量部、ニッケル粒子（フィラメント状、メディアン径２０μｍ）５質量部、およびトルエン４００質量部（固形分が２０質量％）を配合して混合して得られた接着剤組成物を、ワイヤーバーを用いて塗布し、１００℃で３分間加熱することで導電性接着剤層（厚さ１３μｍ）を形成して、実施例５の電磁波シールドフィルムを得た。 Example 5
The epoxy resin composition was applied to a PET film substrate whose surface had been subjected to mold release treatment, and cured by heating at 100° C. for 3 minutes to form a resin layer of epoxy resin having a thickness of 5 μm. Chromium oxide (thickness: 0.2 nm) was formed by plating on both side surfaces of a rolled copper foil having a thickness of 6 μm to obtain a laminate consisting of the second inorganic layer/metal layer/first inorganic layer. Next, the second inorganic layer surface of the laminate was attached to the surface of the resin layer by heat lamination. Next, on the surface of the first inorganic layer, 95 parts by mass of thermoplastic acrylic resin as a conductive adhesive layer, 5 parts by mass of nickel particles (filament shape, median diameter 20 μm), and 400 parts by mass of toluene (solid content is 20% by mass), the adhesive composition obtained by mixing is applied using a wire bar and heated at 100 ° C. for 3 minutes to form a conductive adhesive layer (thickness 13 μm). Thus, an electromagnetic wave shielding film of Example 5 was obtained.
　実施例６～８
　第１無機層の厚さ、第２無機層の厚さ、および導電性粒子の種類を表１に示すとおりに変更したこと以外は実施例５と同様にして、各実施例の電磁波シールドフィルムを作製した。 Examples 6-8
An electromagnetic wave shielding film of each example was prepared in the same manner as in Example 5 except that the thickness of the first inorganic layer, the thickness of the second inorganic layer, and the type of conductive particles were changed as shown in Table 1. made.
　比較例１
　第１無機層を作製せず、金属層と導電性接着剤層を直接貼り合わせた以外は実施例１と同様にして比較例１の電磁波シールドフィルムを作製した。 Comparative example 1
An electromagnetic wave shielding film of Comparative Example 1 was produced in the same manner as in Example 1, except that the metal layer and the conductive adhesive layer were directly bonded together without producing the first inorganic layer.
　比較例２
　第１無機層の厚さを１５０ｎｍとした以外は実施例３と同様にして比較例２の電磁波シールドフィルムを作製した。 Comparative example 2
An electromagnetic wave shielding film of Comparative Example 2 was produced in the same manner as in Example 3, except that the thickness of the first inorganic layer was 150 nm.
　比較例３
　導電性接着剤層の厚さを１μｍとし、銀コート銅粉を球状、メディアン径７μｍとした以外は実施例３と同様にして、比較例３の電磁波シールドフィルムを作製した。 Comparative example 3
An electromagnetic wave shielding film of Comparative Example 3 was produced in the same manner as in Example 3, except that the thickness of the conductive adhesive layer was 1 μm, the silver-coated copper powder was spherical, and the median diameter was 7 μm.
　比較例４
　実施例１の銀コート銅紛に代えてメディアン径が１μｍの球状銀コート銅紛を使用した以外は実施例３と同様にして、比較例４の電磁波シールドフィルムを作製した。 Comparative example 4
An electromagnetic wave shielding film of Comparative Example 4 was produced in the same manner as in Example 3, except that instead of the silver-coated copper powder of Example 1, spherical silver-coated copper powder having a median diameter of 1 μm was used.
［評価］
　実施例及び比較例で得られた各シールドフィルムについて以下の通り評価した。評価結果は表に記載した。なお、使用しなかった項目、及び正確に測定できなかった項目に関しては表中で「－」として表記した。 [evaluation]
Each shield film obtained in Examples and Comparative Examples was evaluated as follows. The evaluation results are shown in the table. Items that were not used and items that could not be accurately measured are indicated as "-" in the table.
（接続抵抗値測定）
　幅５ｍｍ×長さ１０ｍｍの電極２つを間隔１００ｍｍになるように厚さ２ｍｍのガラスエポキシ基板上に配置した。そして、電極の配置面に、実施例で得られたシールドフィルムを、幅５ｍｍ×長さ１３０ｍｍに打ち抜き、常温常圧の条件下で、２ｋｇローラーで１往復させ電極間を繋ぐように導電性接着剤層面を貼り合わせた。導電性接着剤層面を貼り合わせた後、２つの電極間の抵抗値を、４端子法テスター（商品名「ＲＭ３５４２」、日置電機株式会社製）を用いて、電磁波シールドフィルム作製直後、及び６５℃９０％ＲＨの環境で７２時間保管後にそれぞれ測定した。 (connection resistance value measurement)
Two electrodes each having a width of 5 mm and a length of 10 mm were placed on a glass epoxy substrate having a thickness of 2 mm with a spacing of 100 mm. Then, the shielding film obtained in the example was punched out on the electrode arrangement surface to a width of 5 mm and a length of 130 mm, and under normal temperature and pressure conditions, a 2 kg roller was reciprocated once to connect the electrodes to conductive adhesion. The agent layer surfaces were pasted together. After laminating the conductive adhesive layer surfaces, the resistance value between the two electrodes was measured using a 4-terminal method tester (trade name "RM3542", manufactured by Hioki Electric Co., Ltd.) immediately after the electromagnetic shielding film was produced and at 65 ° C. Each was measured after storage for 72 hours in an environment of 90% RH.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明のシールドフィルム（実施例１～８）は、高温高圧条件下ではない緩やかな条件で貼り合わせした場合であっても、接続抵抗値が低く優れたシールド性能を有することが確認された。一方で第１無機層を有さない場合、耐環境性に劣り（比較例１）、第１無機層が厚すぎる場合、接続安定性に劣る結果となった（比較例２）。また、導電性粒子のメディアン径に対する前記導電性接着剤層の厚さの比が小さ過ぎる場合、接着性を発揮することができず、抵抗値が測定できない結果となり（比較例３）、導電性粒子のメディアン径に対する前記導電性接着剤層の厚さの比が大きすぎる場合、接続安定性に劣る結果となった（比較例４）。 It was confirmed that the shielding films of the present invention (Examples 1 to 8) have low connection resistance values and excellent shielding performance even when laminated under mild conditions that are not high temperature and high pressure conditions. On the other hand, when the first inorganic layer was not provided, the environmental resistance was poor (Comparative Example 1), and when the first inorganic layer was too thick, the connection stability was poor (Comparative Example 2). Further, when the ratio of the thickness of the conductive adhesive layer to the median diameter of the conductive particles is too small, the adhesiveness cannot be exhibited, resulting in the resistance value being unmeasurable (Comparative Example 3). When the ratio of the thickness of the conductive adhesive layer to the median diameter of the particles was too large, the connection stability was poor (Comparative Example 4).
　本発明の電磁波シールドフィルムはプリント配線板に好適に使用することができる。 The electromagnetic wave shielding film of the present invention can be suitably used for printed wiring boards.
　１　シールドフィルム
　２　絶縁保護層
　２１　樹脂層
　２２　第２無機層
　３　金属層
　４　第１無機層
　５　導電性接着剤層 REFERENCE SIGNS LIST 1 shield film 2 insulating protective layer 21 resin layer 22 second inorganic layer 3 metal layer 4 first inorganic layer 5 conductive adhesive layer

Claims (10)

  1. 　金属層、第１無機層、および導電性接着剤層がこの順に積層されており、
    　前記第１無機層の厚さは０．１～１００ｎｍであり、
    　前記導電性接着剤層は、バインダー成分および導電性粒子を含み、
    　前記導電性粒子のメディアン径に対する前記導電性接着剤層の厚さの比は０．２～３．５である、電磁波シールドフィルム。     A metal layer, a first inorganic layer, and a conductive adhesive layer are laminated in this order,
    The thickness of the first inorganic layer is 0.1 to 100 nm,
    The conductive adhesive layer contains a binder component and conductive particles,
    An electromagnetic wave shielding film, wherein the ratio of the thickness of the conductive adhesive layer to the median diameter of the conductive particles is 0.2 to 3.5.
  2. 　前記金属層における、前記第１無機層とは反対側の表面に絶縁保護層が直接積層されている、請求項１に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to claim 1, wherein an insulating protective layer is directly laminated on the surface of the metal layer opposite to the first inorganic layer.
  3. 　前記絶縁保護層として前記金属層と直接積層した第２無機層を有する請求項２に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to claim 2, which has a second inorganic layer directly laminated with the metal layer as the insulating protective layer.
  4. 　前記第２無機層の厚さは０．１～１００ｎｍである請求項３に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to claim 3, wherein the second inorganic layer has a thickness of 0.1 to 100 nm.
  5. 　前記第２無機層は金属酸化物から構成される請求項３または４に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to claim 3 or 4, wherein the second inorganic layer is composed of a metal oxide.
  6. 　前記絶縁保護層として樹脂層を有する請求項２～５のいずれか１項に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to any one of claims 2 to 5, which has a resin layer as the insulating protective layer.
  7. 　前記第１無機層は金属酸化物から構成される請求項１～６のいずれか１項に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to any one of claims 1 to 6, wherein the first inorganic layer is composed of a metal oxide.
  8. 　前記第１無機層は前記金属層と直接積層している請求項１～７のいずれか１項に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to any one of claims 1 to 7, wherein the first inorganic layer is directly laminated with the metal layer.
  9. 　前記導電性接着剤層は前記第１無機層と直接積層している請求項１～８のいずれか１項に記載の電磁波シールドフィルム。 The electromagnetic wave shielding film according to any one of claims 1 to 8, wherein the conductive adhesive layer is directly laminated with the first inorganic layer.
  10. 　請求項１～９のいずれか１項に記載の電磁波シールドフィルムを備えたシールドプリント配線板。 A shield printed wiring board comprising the electromagnetic wave shielding film according to any one of claims 1 to 9.
PCT/JP2022/022433 2021-06-02 2022-06-02 Electromagnetic wave shield film WO2022255438A1 (en)

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Publication number Priority date Publication date Assignee Title
JP2003033994A (en) * 2001-07-24 2003-02-04 Toyo Metallizing Co Ltd Metallized film and metal foil
JP2005056906A (en) * 2003-08-05 2005-03-03 Reiko Co Ltd Electromagnetic wave shielding transfer film
WO2011121801A1 (en) * 2010-03-30 2011-10-06 Jx日鉱日石金属株式会社 Composite for electromagnetic shielding
WO2016136247A1 (en) * 2015-02-25 2016-09-01 東洋インキＳｃホールディングス株式会社 Electromagnetic wave shielding sheet, electromagnetic wave shielding wiring circuit board, and electronic device
JP2020024977A (en) * 2018-08-06 2020-02-13 信越ポリマー株式会社 Electromagnetic wave shielding film, manufacturing method thereof, printed wiring board with electromagnetic wave shielding film, and manufacturing method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003033994A (en) * 2001-07-24 2003-02-04 Toyo Metallizing Co Ltd Metallized film and metal foil
JP2005056906A (en) * 2003-08-05 2005-03-03 Reiko Co Ltd Electromagnetic wave shielding transfer film
WO2011121801A1 (en) * 2010-03-30 2011-10-06 Jx日鉱日石金属株式会社 Composite for electromagnetic shielding
WO2016136247A1 (en) * 2015-02-25 2016-09-01 東洋インキＳｃホールディングス株式会社 Electromagnetic wave shielding sheet, electromagnetic wave shielding wiring circuit board, and electronic device
JP2020024977A (en) * 2018-08-06 2020-02-13 信越ポリマー株式会社 Electromagnetic wave shielding film, manufacturing method thereof, printed wiring board with electromagnetic wave shielding film, and manufacturing method thereof

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