JP2018053155A - Photosetting composition, coated film, manufacturing method of coated film, electromagnetic shield film, printed wiring board with electromagnetic shield film and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosetting composition having sufficient hardness although it contains a coloring agent and capable of forming a cured article having fire retardancy, and an electromagnetic shield film having an insulation resin layer with sufficient hardness although it is a cured article of the photosetting composition containing a coloring agent and having fire retardancy.SOLUTION: There are provided a photosetting composition containing a compound having a polymerizable carbon-carbon unsaturated bond, a phosphorous radical polymerization initiator, and a coloring agent; an electromagnetic shield film 1 having an insulation resin layer 10, a metal thin film layer 20 neighboring the insulation resin layer 10, and an adhesive layer 22 neighboring an opposite side of the metal thin film layer 20 to the insulation resin layer 10, in which the insulation resin layer 10 is a coated film consisting of a cured article of the photosetting composition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photocurable composition, a coating film comprising a cured product of the photocurable composition, a method for producing the coating film, an electromagnetic wave shielding film having an insulating resin layer comprising the coating film, and a printed wiring with an electromagnetic wave shielding film. The present invention relates to a plate and a manufacturing method thereof.

  In order to shield electromagnetic noise generated from a flexible printed wiring board and external electromagnetic noise, from an insulating resin layer and a conductive layer composed of a metal thin film layer and a conductive adhesive layer adjacent to the insulating resin layer An electromagnetic wave shielding film may be provided on the surface of the flexible printed wiring board.

The insulating resin layer in the electromagnetic wave shielding film is made of a cured product of the curable composition.
Moreover, an insulating resin layer may be colored with a coloring agent (especially black coloring agent) from the point of concealment of the printed circuit of a flexible printed wiring board, and the designability of an electromagnetic wave shield film (refer patent document 1).

JP, 2006-054261, A

However, when the curable composition for forming the colored insulating resin layer is a photocurable composition, the colorant contained in the photocurable composition absorbs light such as ultraviolet rays. Curing of the composition will be insufficient. Therefore, the hardness of the insulating resin layer becomes insufficient.
Further, the insulating resin layer made of a cured product of the photocurable composition has insufficient flame retardancy.

  The present invention is a photocurable composition that can form a cured product having sufficient hardness and flame retardancy despite containing a colorant; and a cured product of a photocurable composition containing a colorant. Nevertheless, the coating film having sufficient hardness and flame retardancy and a method for producing the same; the insulating resin layer having sufficient hardness despite being a cured product of a photocurable composition containing a colorant An electromagnetic wave shielding film having flame retardancy, a printed wiring board with an electromagnetic wave shielding film, and a method for producing the same are provided.

＜９＞前記＜１＞〜＜８＞のいずれかの光硬化性組成物の硬化物からなる、塗膜。
＜１０＞基材の表面に、前記＜１＞〜＜８＞のいずれかの光硬化性組成物を塗布し、前記光硬化性組成物に光を照射することを特徴とする塗膜の製造方法。
＜１１＞絶縁樹脂層と、前記絶縁樹脂層に隣接する金属薄膜層と、前記金属薄膜層の前記絶縁樹脂層とは反対側に隣接する接着剤層とを有する電磁波シールドフィルムであり；前記絶縁樹脂層が、前記＜９＞の塗膜である、電磁波シールドフィルム。
＜１２＞前記接着剤層が、異方導電性接着剤層であることを特徴とする前記＜１１＞の電磁波シールドフィルム。
＜１３＞基板の少なくとも片面にプリント回路が設けられたプリント配線板と、前記プリント配線板の前記プリント回路が設けられた側の表面に隣接する絶縁フィルムと、前記接着剤層が前記絶縁フィルムに隣接するように設けられた前記＜１１＞または＜１２＞の電磁波シールドフィルムとを有する、電磁波シールドフィルム付きプリント配線板。
＜１４＞前記＜１３＞の電磁波シールドフィルム付きプリント配線板を製造する方法であり、前記接着剤層が前記絶縁フィルムに圧着されていることを特徴とする電磁波シールドフィルム付きプリント配線板の製造方法。 The present invention has the following aspects.
<1> A photocurable composition comprising a compound having a polymerizable carbon-carbon unsaturated bond, a phosphorus-based radical photopolymerization initiator, and a colorant.
<2> The photocurable composition according to <1>, wherein the compound having a polymerizable carbon-carbon unsaturated bond is a compound having a (meth) acryloyl group.
<3> The photocurable composition according to <2>, wherein the compound having a (meth) acryloyl group is an acrylic polymer acrylate.
<4> The photocurable composition according to any one of <1> to <3>, further including a solvent.
<5> The photocurable composition according to any one of <1> to <4>, wherein the colorant is a black colorant.
<6> The photocurable composition according to <5>, wherein the black colorant is a carbon black pigment.
<7> The photocurable composition according to <5>, wherein the black colorant is an azo black dye.
<8> The light according to any one of <1> to <7>, wherein the phosphorus-based radical photopolymerization initiator is a compound represented by the following formula (1) or a compound represented by the following formula (2): Curable composition.

<9> A coating film comprising a cured product of the photocurable composition according to any one of <1> to <8>.
<10> Production of a coating film characterized by applying the photocurable composition of any one of <1> to <8> to the surface of a substrate and irradiating the photocurable composition with light. Method.
<11> An electromagnetic wave shielding film having an insulating resin layer, a metal thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the side of the metal thin film layer opposite to the insulating resin layer; The electromagnetic wave shielding film whose resin layer is a coating film of said <9>.
<12> The electromagnetic wave shielding film according to <11>, wherein the adhesive layer is an anisotropic conductive adhesive layer.
<13> A printed wiring board provided with a printed circuit on at least one side of the substrate, an insulating film adjacent to the surface of the printed wiring board provided with the printed circuit, and the adhesive layer on the insulating film The printed wiring board with an electromagnetic wave shielding film which has said <11> or <12> electromagnetic wave shielding film provided so that it might adjoin.
<14> A method for producing a printed wiring board with an electromagnetic wave shielding film according to <13>, wherein the adhesive layer is pressure-bonded to the insulating film. .

The photocurable composition of the present invention can form a cured product having sufficient hardness and flame retardancy despite containing a colorant.
Although the coating film of the present invention is a cured product of a photocurable composition containing a colorant, it has sufficient hardness and flame retardancy.
According to the method for producing a coating film of the present invention, a coating film having sufficient hardness and flame retardancy can be produced despite being a cured product of a photocurable composition containing a colorant.
Although the electromagnetic wave shielding film of the present invention is a cured product of a photocurable composition containing a colorant, the insulating resin layer has sufficient hardness and has flame retardancy.
Although the printed wiring board with an electromagnetic wave shielding film of the present invention is a cured product of a photocurable composition containing a colorant, the insulating resin layer of the electromagnetic wave shielding film has sufficient hardness and has flame retardancy. Have.
According to the method for producing a printed wiring board with an electromagnetic wave shielding film of the present invention, the insulating resin layer of the electromagnetic wave shielding film has sufficient hardness even though it is a cured product of a photocurable composition containing a colorant, And the printed wiring board with an electromagnetic wave shielding film which has a flame retardance can be manufactured.

It is sectional drawing which shows one Embodiment of the electromagnetic wave shield film of this invention. It is sectional drawing which shows other embodiment of the electromagnetic wave shielding film of this invention. It is sectional drawing which shows a process (a), a process (b1), and a process (b2) among the manufacturing processes of the electromagnetic wave shield film of FIG. It is sectional drawing which shows process (c1)-(c3) among the manufacturing processes of the electromagnetic wave shield film of FIG. It is sectional drawing which shows one Embodiment of the printed wiring board with an electromagnetic wave shield film of this invention. It is sectional drawing which shows the manufacturing process of the printed wiring board with an electromagnetic wave shielding film of FIG.

The following definitions of terms apply throughout this specification and the claims.
“Light” is a general term for ultraviolet rays, visible rays, infrared rays, electron beams and radiation.
The “(meth) acryloyl group” is a general term for an acryloyl group and a methacryloyl group.
The “isotropic conductive adhesive layer” means a conductive adhesive layer having conductivity in the thickness direction and the surface direction.
The “anisotropic conductive adhesive layer” means a conductive adhesive layer having conductivity in the thickness direction and not having conductivity in the surface direction.
The “conductive adhesive layer having no conductivity in the plane direction” means a conductive adhesive layer having a surface resistance of 1 × 10 ⁴ Ω or more.
For the average particle diameter of the conductive particles, 30 conductive particles are randomly selected from the microscopic image of the conductive particles, and the minimum diameter and the maximum diameter are measured for each conductive particle. Is the value obtained by arithmetically averaging the measured particle diameters of the 30 conductive particles.
The thickness of the film (release film, insulating film, etc.), coating film (insulating resin layer, conductive adhesive layer, etc.), metal thin film layer, etc. is observed at a cross section of the object to be measured using a microscope. Thickness was measured and averaged.
The surface resistance is measured by using two thin film metal electrodes (length 10 mm, width 5 mm, distance 10 mm between electrodes) formed by depositing gold on quartz glass, placing an object to be measured on the electrodes, and measuring the surface resistance. This is a resistance between electrodes measured by pressing a 10 mm × 20 mm region of the object to be measured with a load of 0.049 N from above the object with a measurement current of 1 mA or less.

<Photocurable composition>
The photocurable composition of the present invention contains a compound having a polymerizable carbon-carbon unsaturated bond, a phosphorus-based radical photopolymerization initiator, and a colorant.
It is preferable that the photocurable composition of this invention further contains a solvent from the point that the coating film which consists of hardened | cured material of a photocurable composition is excellent in adhesiveness with a base material.
The photocurable composition of the present invention may further contain other components as necessary within a range not impairing the effects of the present invention.

(Compound having a polymerizable carbon-carbon unsaturated bond)
As a compound having a polymerizable carbon-carbon unsaturated bond, a compound having a (meth) acryloyl group, a compound having a (meth) acrylamide group, a compound having a vinyl group, a compound having a vinyl ester group, an allyl vinyl ether group The compound etc. are mentioned and the compound which has a (meth) acryloyl group from the point which the coating film consisting of the hardened | cured material of a photocurable composition is excellent in adhesiveness with a base material is preferable.

  Examples of the compound having a (meth) acryloyl group include an acrylate resin (acrylic polymer acrylate, urethane acrylate, polyester acrylate, etc.), a monomer having a (meth) acryloyl group, and the like, and a coating made of a cured product of a photocurable composition. Acrylic polymer acrylate is preferred because the film is excellent in adhesion to the substrate.

(Phosphorus radical photopolymerization initiator)
Examples of the phosphorous photoradical polymerization initiator include acylphosphine oxide photoradical polymerization initiators and the like, and the acylphosphine oxide based photopolymer composition can be sufficiently cured even if it contains a coloring agent. Photo radical polymerization initiators are preferred.

  As the acyl phosphine oxide-based photoradical polymerization initiator, a compound represented by the following formula (1) (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), a compound represented by the following formula (2) (Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, and the like. As the acylphosphine oxide-based photoradical polymerization initiator, a compound represented by the formula (1) or a compound represented by the formula (2) is preferable.

Examples of commercially available compounds represented by the formula (1) include Irgacure (registered trademark) TPO manufactured by BASF.
Examples of commercially available compounds represented by the formula (2) include Irgacure (registered trademark) 819 manufactured by BASF.

(Coloring agent)
Examples of the colorant include pigments and dyes.

Examples of the pigment include inorganic pigments and organic pigments, and examples thereof include the following.
Black pigment: carbon black, acetylene black, lamp black, titanium black, aniline black, anthraquinone black pigment, perylene black pigment and the like.
Green pigment: chrome green, pigment green, etc.
Blue pigment: cobalt blue, phthalocyanine blue, etc.
Red pigment: petal, azo pigment, quinacridone, etc.
Yellow pigment: Yellow lead, cadmium yellow, azo pigment, isoindolinone, etc.
White pigment: zinc white, titanium oxide, etc.

Examples of the dye include water-soluble dyes (acid dyes, basic dyes, direct dyes, food dyes, etc.), oil-soluble dyes (direct dyes, acid dyes, basic dyes, etc.) and the like.
Specific examples of the black dye include azo black dyes (Mordant Black 1, Acid Black 52, Solvent Black 22, Solvent Black 27, Solvent Black 29, Solvent Black 34, and the like).

As the colorant, a black colorant is preferable from the viewpoint of concealing the printed circuit of the flexible printed wiring board and design of the electromagnetic wave shielding film.
Examples of black pigments include oxides such as copper, chromium, and zinc, nitrides of titanium, and carbon. From the viewpoint of dispersibility, carbon black pigments (such as carbon black) are preferable.
Examples of the black dye include complexes of copper, chromium, nickel, cobalt, and the like, and azo compounds. From the viewpoint of solubility, azo black dyes are preferable.

(solvent)
Any solvent may be used as long as it can dissolve a compound having a polymerizable carbon-carbon unsaturated bond, a phosphorus-based radical photopolymerization initiator, a dye, and the like.
Solvents include esters (butyl acetate, ethyl acetate, methyl acetate, isopropyl acetate, ethylene glycol monoacetate, etc.), ketones (methyl ethyl ketone, methyl isobutyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, etc.), alcohols (methanol, ethanol, isopropanol). , Butanol, propylene glycol monomethyl ether, propylene glycol and the like).

(Other ingredients)
Examples of other components include a filler, a flame retardant, a compound having an isocyanate group, a compound having an epoxy group, and a silane coupling agent.
Examples of the filler include barium carbonate, clay, silica, talc and the like.

(Amount of each component)
The amount of the phosphorus-based radical photopolymerization initiator is preferably 0.1 parts by mass or more and 20 parts by mass or less, and preferably 1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the compound having a polymerizable carbon-carbon unsaturated bond. Part or less is more preferable. If the blending amount of the phosphorous radical photopolymerization initiator is not less than the lower limit of the above range, a cured product having further sufficient hardness and flame retardancy can be formed. If the compounding amount of the phosphorous radical photopolymerization initiator is not more than the upper limit of the above range, the unreacted phosphorous radical photopolymerization initiator remaining in the cured product can be suppressed.

  The blending amount of the colorant is preferably 0.1 parts by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the compound having a polymerizable carbon-carbon unsaturated bond. . When the blending amount of the colorant is at least the lower limit of the above range, the concealability of the printed circuit of the flexible printed wiring board and the design of the electromagnetic wave shielding film are further improved. If the blending amount of the colorant is not more than the upper limit of the above range, the photocurable composition can be further sufficiently cured.

(Function and effect)
The photocurable composition of the present invention described above contains a phosphorus-based radical photopolymerization initiator that is not easily affected by light absorption by the colorant as a photoradical polymerization initiator. Can be fully cured. Therefore, a cured product having a sufficient hardness can be formed despite the inclusion of the colorant. Moreover, since the phosphorus type radical photopolymerization initiator which can provide a flame retardance is included, the hardened | cured material which has a flame retardance can be formed.

<Coating film>
The coating film of this invention consists of hardened | cured material of the photocurable composition of this invention.
The coating film of the present invention is obtained by applying the photocurable composition of the present invention to the surface of a substrate and drying it when it contains a solvent, and then irradiating the photocurable composition with light (ultraviolet rays or the like). It is formed by semi-curing or curing the curable composition.
Examples of the substrate include a film, a metal foil, a vapor deposition film, glass, and paper. Specifically, a metal thin film layer, a first release film and the like in an electromagnetic wave shielding film described later can be used.

(Function and effect)
Since the coating film of the present invention described above consists of a cured product of the photocurable composition of the present invention, it is sufficient even though it is a cured product of the photocurable composition containing a colorant. Have good hardness and flame retardancy.

<Electromagnetic wave shielding film>
FIG. 1 is a sectional view showing a first embodiment of an electromagnetic wave shielding film obtained by the production method of the present invention, and FIG. 2 shows a second embodiment of the electromagnetic wave shielding film obtained by the production method of the present invention. It is sectional drawing shown.
The electromagnetic wave shielding film 1 of the first embodiment and the second embodiment includes an insulating resin layer 10; a metal thin film layer 20 adjacent to the insulating resin layer 10, and an opposite side of the metal thin film layer 20 to the insulating resin layer 10. A first release film 30 adjacent to the side of the insulating resin layer 10 opposite to the metal thin film layer 20; and adjacent to the side of the adhesive layer 22 opposite to the metal thin film layer 20; And a second release film 40.

The electromagnetic wave shielding film 1 of the first embodiment is an example in which the adhesive layer 22 is an anisotropic conductive adhesive layer 24.
The electromagnetic wave shielding film 1 of the second embodiment is an example in which the adhesive layer 22 is an isotropic conductive adhesive layer 26.

(Insulating resin layer)
The insulating resin layer 10 is a protective layer for the metal thin film layer 20 after the electromagnetic wave shielding film 1 is attached to the surface of the insulating film provided on the surface of the flexible printed wiring board and the first release film 30 is peeled off. It becomes.

  The insulating resin layer 10 is a coating film made of a cured product of the photocurable composition of the present invention. Specifically, the photocurable composition of the present invention is applied to the surface of the metal thin film layer 20 or the first release film 30, and when it contains a solvent, it is dried and then irradiated with light (such as ultraviolet rays). The coating film is formed by semi-curing or curing.

The surface resistance of the insulating resin layer 10 is preferably 1 × 10 ⁶ Ω or more from the viewpoint of electrical insulation. The surface resistance of the insulating resin layer 10 is preferably 1 × 10 ¹⁹ Ω or less from a practical point of view.
The thickness of the insulating resin layer 10 is preferably 0.1 μm or more and 30 μm or less, and more preferably 0.5 μm or more and 20 μm or less. If the thickness of the insulating resin layer 10 is not less than the lower limit of the above range, the insulating resin layer 10 can sufficiently exhibit the function as a protective layer. If the thickness of the insulating resin layer 10 is not more than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned.

On the surface of the insulating resin layer 10, irregularities on the surface of the first release film 30 may be transferred from the following points.
-Make the scratches and the like generated on the surface of the insulating resin layer 10 inconspicuous.
・ Prevents regular reflection of light from a flexible printed wiring board with an electromagnetic wave shielding film around an optical sensor (CCD image sensor of a camera module, CMOS image sensor, etc.).

(Metal thin film layer)
The metal thin film layer 20 is a layer made of a metal thin film. Since the metal thin film layer 20 is formed so as to spread in the surface direction, it has conductivity in the surface direction and functions as an electromagnetic wave shielding layer or the like.

  Examples of the metal thin film layer 20 include a vapor deposition film formed by physical vapor deposition (vacuum vapor deposition, sputtering, ion beam vapor deposition, electron beam vapor deposition, etc.) or CVD, a plating film formed by plating, a metal foil, and the like. From the point of excellent surface direction conductivity, a vapor deposition film and a plating film are preferable, the thickness can be reduced, and even if the thickness is small, the surface direction conductivity is excellent and can be easily formed by a dry process. A vapor deposition film is more preferable, and a vapor deposition film formed by physical vapor deposition is more preferable.

  Examples of the metal constituting the metal thin film layer 20 include aluminum, silver, copper, gold, and conductive ceramics. From the viewpoint of electrical conductivity, copper is preferable, and from the viewpoint of chemical stability, conductive ceramics are preferable.

  The surface resistance of the metal thin film layer 20 is preferably 0.001Ω to 1Ω, and more preferably 0.001Ω to 0.1Ω. If the surface resistance of the metal thin film layer 20 is not less than the lower limit of the above range, the metal thin film layer 20 can be made sufficiently thin. If the surface resistance of the metal thin film layer 20 is not more than the upper limit of the above range, it can function sufficiently as an electromagnetic wave shielding layer.

  The thickness of the metal thin film layer 20 is preferably 0.01 μm or more and 1 μm or less, and more preferably 0.05 μm or more and 1 μm or less. When the thickness of the metal thin film layer 20 is 0.01 μm or more, the surface conductivity is further improved. If the thickness of the metal thin film layer 20 is 0.05 μm or more, the electromagnetic noise shielding effect is further improved. If the thickness of the metal thin film layer 20 is less than or equal to the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. Further, the productivity and flexibility of the electromagnetic wave shielding film 1 are improved.

(Adhesive layer)
The adhesive layer 22 is a layer for attaching the electromagnetic wave shielding film 1 to a printed wiring board with an insulating film.
The adhesive layer 22 may be a simple adhesive layer having no electrical conductivity, and is an electrically conductive adhesive layer having electrical conductivity for electrically connecting the electromagnetic wave shielding film 1 and the printed wiring board. May be. As the adhesive layer 22, a conductive adhesive layer is preferable from the viewpoint that the metal thin film layer 20 functions sufficiently as an electromagnetic wave shielding layer.

(Conductive adhesive layer)
The conductive adhesive layer has conductivity at least in the thickness direction and has adhesiveness.
As the conductive adhesive layer, an anisotropic conductive adhesive layer 24 having conductivity in the thickness direction and having no conductivity in the surface direction, or having conductivity in the thickness direction and the surface direction, etc. An electrically conductive adhesive layer 26 is exemplified. As the conductive adhesive layer, the conductive adhesive layer can be thinned, the amount of conductive particles is reduced, and as a result, the electromagnetic wave shielding film 1 can be thinned, and the flexibility of the electromagnetic wave shielding film 1 is improved. The anisotropic conductive adhesive layer 24 is preferable. As the conductive adhesive layer, the isotropic conductive adhesive layer 26 is preferable because it can sufficiently function as an electromagnetic wave shielding layer.

Examples of the conductive adhesive layer include a layer containing an adhesive and conductive particles.
The anisotropic conductive adhesive layer 24 includes, for example, an adhesive 24a and conductive particles 24b.
The isotropic conductive adhesive layer 26 includes, for example, an adhesive 26a and conductive particles 26b.

Examples of the adhesive include solvent volatilization type adhesives and thermosetting adhesives.
Examples of the solvent volatilization type adhesive include those containing a thermoplastic resin and a solvent.
As a thermosetting adhesive, what contains a thermosetting resin and a hardening | curing agent is mentioned.

  Examples of the thermoplastic resin include vinyl acetate resin, ethylene vinyl acetate resin, polyvinyl alcohol, vinyl chloride resin, acrylic resin, polyamide resin, polystyrene resin, cyanoacrylate, and cellulose.

Examples of the thermosetting resin include an epoxy resin, a phenol resin, an amino resin, an alkyd resin, a urethane resin, a synthetic rubber, and an ultraviolet curable acrylate resin. As the thermosetting resin, an epoxy resin is preferable from the viewpoint of excellent heat resistance.
As a hardening | curing agent, the well-known hardening | curing agent according to the kind of thermosetting resin is mentioned.
The conductive adhesive layer containing the thermosetting adhesive may be in an uncured state or in a B-staged state.

The adhesive may contain a rubber component for imparting flexibility (carboxy-modified nitrile rubber, acrylic rubber, etc.), a tackifier, and the like.
The adhesive may contain a flame retardant as necessary.
The adhesive may contain a cellulose resin and microfibril (glass fiber or the like) in order to increase the strength of the conductive adhesive layer and improve the punching characteristics.
The adhesive may contain other components as necessary within a range not impairing the effects of the present invention.

  Examples of the conductive particles include metal (silver, platinum, gold, copper, nickel, palladium, aluminum, solder, etc.) particles, graphite powder, calcined carbon particles, plated calcined carbon particles, and the like. As the conductive particles, metal particles are preferable and copper particles are preferable from the viewpoint that the conductive adhesive layer has an appropriate hardness and can reduce pressure loss in the conductive adhesive layer during hot pressing. More preferred.

  The average particle diameter of the conductive particles 24b in the anisotropic conductive adhesive layer 24 is preferably 2 μm to 26 μm, and more preferably 4 μm to 16 μm. If the average particle diameter of the conductive particles 24b is equal to or greater than the lower limit of the above range, the thickness of the anisotropic conductive adhesive layer 24 can be ensured, and sufficient adhesive strength can be obtained. If the average particle diameter of the conductive particles 24b is equal to or less than the upper limit of the above range, the fluidity of the anisotropic conductive adhesive layer 24 (followability to the shape of the through holes of the insulating film) can be secured, and the insulating film The inside of the through hole can be sufficiently filled with a conductive adhesive.

  The average particle diameter of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.2 μm or more and 1 μm or less. When the average particle diameter of the conductive particles 26b is equal to or greater than the lower limit of the above range, the number of contact points of the conductive particles 26b increases, and the conductivity in the three-dimensional direction can be stably increased. If the average particle diameter of the conductive particles 26b is less than or equal to the upper limit of the above range, the fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through holes of the insulating film) can be secured, and the insulating film The inside of the through hole can be sufficiently filled with a conductive adhesive.

  The proportion of the conductive particles 24b in the anisotropic conductive adhesive layer 24 is preferably 1% by volume to 30% by volume, and preferably 2% by volume to 10% by volume, out of 100% by volume of the anisotropic conductive adhesive layer 24. The following is more preferable. When the ratio of the conductive particles 24b is equal to or higher than the lower limit of the above range, the conductivity of the anisotropic conductive adhesive layer 24 is improved. When the ratio of the conductive particles 24b is equal to or less than the upper limit of the above range, the adhesiveness and fluidity (followability to the shape of the through hole of the insulating film) of the anisotropic conductive adhesive layer 24 are improved. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

  The proportion of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 50% by volume or more and 80% by volume or less in 100% by volume of the isotropic conductive adhesive layer 26, and 60% by volume or more and 70% by volume. The following is more preferable. When the ratio of the conductive particles 26b is equal to or higher than the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 is improved. When the ratio of the conductive particles 26b is equal to or less than the upper limit of the above range, the adhesiveness and fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through hole of the insulating film) are improved. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

The surface resistance of the anisotropic conductive adhesive layer 24 is preferably 1 × 10 ⁴ Ω to 1 × 10 ¹⁶ Ω, more preferably 1 × 10 ⁶ Ω to 1 × 10 ¹⁴ Ω. If the surface resistance of the anisotropic conductive adhesive layer 24 is not less than the lower limit of the above range, the content of the conductive particles 24b can be kept low. If the surface resistance of the anisotropic conductive adhesive layer 24 is not more than the upper limit of the above range, there is no problem in anisotropy in practice.

  The surface resistance of the isotropic conductive adhesive layer 26 is preferably 0.05Ω to 2.0Ω, more preferably 0.1Ω to 1.0Ω. If the surface resistance of the isotropic conductive adhesive layer 26 is equal to or greater than the lower limit of the above range, the content of the conductive particles 26b can be kept low, the viscosity of the conductive adhesive does not become too high, and the coatability is further increased. It becomes good. Further, the fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through hole of the insulating film) can be further ensured. If the surface resistance of the isotropic conductive adhesive layer 26 is less than or equal to the upper limit of the above range, the entire surface of the isotropic conductive adhesive layer 26 has uniform conductivity.

  The thickness of the anisotropic conductive adhesive layer 24 is preferably 3 μm or more and 25 μm or less, and more preferably 5 μm or more and 15 μm or less. If the thickness of the anisotropic conductive adhesive layer 24 is equal to or greater than the lower limit of the above range, the fluidity of the anisotropic conductive adhesive layer 24 (followability to the shape of the through hole of the insulating film) can be secured, The through hole of the insulating film can be sufficiently filled with the conductive adhesive. If the thickness of the anisotropic conductive adhesive layer 24 is equal to or less than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

  The thickness of the isotropic conductive adhesive layer 26 is preferably 5 μm or more and 20 μm or less, and more preferably 7 μm or more and 17 μm or less. If the thickness of the isotropic conductive adhesive layer 26 is equal to or greater than the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 becomes good and can sufficiently function as an electromagnetic wave shielding layer. Further, the fluidity of the isotropic conductive adhesive layer 26 (followability to the shape of the through hole of the insulating film) can be ensured, and the through hole of the insulating film can be sufficiently filled with the conductive adhesive. The bendability can be secured and the isotropic conductive adhesive layer 26 will not be torn even if it is repeatedly bent. If the thickness of the isotropic conductive adhesive layer 26 is equal to or less than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. Moreover, the flexibility of the electromagnetic wave shielding film 1 is improved.

(First release film)
The first release film 30 serves as a protective film for the insulating resin layer 10 and improves the handling properties of the electromagnetic wave shielding film 1. The first release film 30 is peeled from the insulating resin layer 10 after the electromagnetic wave shielding film 1 is attached to the printed wiring board with an insulating film.

The 1st release film 30 has the base material layer 32 and the adhesive layer 34 provided in the surface at the side of the insulating resin layer 10 of the base material layer 32, for example.
The first release film 30 may be one in which the pressure-sensitive adhesive layer 34 is directly provided on the surface of the base material layer 32; after the pressure-sensitive adhesive layer 34 is provided on the surface of the insulating resin layer 10, the pressure-sensitive adhesive layer The adhesive layer 34 may be provided on the surface of the base material layer 32 by attaching the base material layer 32 to the surface of the base material 34.

As the resin material of the base material layer 32, polyethylene terephthalate (hereinafter also referred to as PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, ethylene-vinyl acetate Examples thereof include polymers, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, and liquid crystal polymers. As the resin material, PET is preferable from the viewpoint of heat resistance (dimensional stability) and price when the electromagnetic wave shielding film 1 is manufactured.
The base material layer 32 may contain a colorant or a filler.

  The thickness of the base material layer 32 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 150 μm or less, and further preferably 25 μm or more and 100 μm or less. If the thickness of the base material layer 32 is not less than the lower limit of the above range, the handling property of the electromagnetic wave shielding film 1 will be good. If the thickness of the base material layer 32 is equal to or less than the upper limit of the above range, heat is easily transmitted to the adhesive layer 22 when the electromagnetic wave shielding film 1 is hot pressed onto a printed wiring board with an insulating film.

The pressure-sensitive adhesive layer 34 is formed by applying a pressure-sensitive adhesive to the surface of the base material layer 32 or the insulating resin layer 10. When the first release film 30 has the pressure-sensitive adhesive layer 34, when the second release film 40 is peeled from the adhesive layer 22, or when the electromagnetic wave shielding film 1 is attached to a printed wiring board or the like by hot pressing. In addition, the first release film 30 can be prevented from peeling from the insulating resin layer 10, and the first release film 30 can sufficiently serve as a protective film.
A known adhesive may be used as the adhesive.

  The thickness of the pressure-sensitive adhesive layer 34 is preferably 0.05 μm or more and 2.0 μm or less, and more preferably 0.1 μm or more and 1.5 μm or less. If the thickness of the pressure-sensitive adhesive layer 34 is within the above range, the surface of the first release film 30 has appropriate adhesiveness.

(Second release film)
The second release film 40 protects the adhesive layer 22 and improves the handling properties of the electromagnetic wave shielding film 1. The second release film 40 is peeled from the adhesive layer 22 before the electromagnetic wave shielding film 1 is attached to the printed wiring board with an insulating film.

  The second release film 40 includes, for example, a base material layer 42 and a release agent layer 44 provided on the surface of the base material layer 42 on the conductive adhesive layer side.

Examples of the resin material for the base material layer 42 include the same resin materials as those for the base material layer 32 of the first release film 30.
The base material layer 42 may contain a colorant or a filler.
The thickness of the base material layer 42 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 150 μm or less, and further preferably 25 μm or more and 100 μm or less.

The release agent layer 44 is formed by subjecting the surface of the base material layer 42 to a release treatment using a release agent. When the second release film 40 includes the release agent layer 44, the second release film 40 can be easily peeled off when the second release film 40 is peeled from the adhesive layer 22, and the adhesive. The layer 22 becomes difficult to break.
As the release agent, a known release agent may be used.

  The thickness of the release agent layer 44 is preferably 0.05 μm or more and 2.0 μm or less, and more preferably 0.1 μm or more and 1.5 μm or less. When the thickness of the release agent layer 44 is within the above range, the second release film 40 is further easily peeled off.

(Thickness of electromagnetic shielding film)
The thickness of the electromagnetic shielding film 1 (excluding the release film) is preferably 10 μm or more and 45 μm or less, and more preferably 10 μm or more and 30 μm or less. When the thickness of the electromagnetic wave shielding film 1 (excluding the release film) is equal to or greater than the lower limit of the above range, it is difficult to break when the first release film 30 is peeled off. If the thickness of the electromagnetic wave shielding film 1 (excluding the release film) is not more than the upper limit of the above range, the printed wiring board with the electromagnetic wave shielding film can be thinned.

(Method for producing electromagnetic shielding film)
The electromagnetic wave shielding film of the present invention is produced, for example, by the following method (α), the following method (β), or the like. As a method for producing the electromagnetic wave shielding film of the present invention, the method (α) is preferable because the adhesion between the insulating resin layer and the metal thin film layer is improved.

The method (α) is a method having the following steps (a) to (c).
Process (a): The process of providing a metal thin film layer on the surface of a carrier film as needed.
Step (b): A step of providing an insulating resin layer on the surface of the metal thin film layer provided on the surface of the carrier film.
Step (c): A step of peeling the carrier film from the metal thin film layer and providing an adhesive layer on the surface of the metal thin film layer opposite to the insulating resin layer.

The method (β) is a method having the following steps (x) to (z).
Step (x): A step of providing an insulating resin layer on the surface of the first release film.
Step (y): A step of providing a metal thin film layer on the surface of the insulating resin layer.
Step (z): A step of providing an adhesive layer on the surface of the metal thin film layer.

Hereinafter, the method (α) will be described in detail.
(Process (a))
As a carrier film, what has a base material layer and the adhesive layer provided in the surface of the base material layer is mentioned.
Examples of the resin material for the base material layer include the same resin materials for the base material layer 32 of the first release film 30.
A known pressure-sensitive adhesive may be used as the pressure-sensitive adhesive for the pressure-sensitive adhesive layer.

  Examples of the method for forming the metal thin film layer include physical vapor deposition, a method of forming a vapor deposition film by CVD, a method of forming a plating film by plating, and a method of attaching a metal foil. From the point of being able to form a metal thin film layer having excellent surface conductivity, physical vapor deposition, a method of forming a vapor deposition film by CVD, or a method of forming a plating film by plating is preferable, and the thickness of the metal thin film layer can be reduced, In addition, a method of forming a deposited film by physical vapor deposition or CVD is more preferable because a metal thin film layer having excellent surface conductivity can be formed even if the thickness is small, and a metal thin film layer can be easily formed by a dry process. A method of forming a deposited film by physical vapor deposition is more preferable.

  Step (a) may be omitted by obtaining a commercially available laminate in which a metal thin film layer is provided on the surface of the carrier film.

(Process (b))
As a method of providing an insulating resin layer on the surface of the metal thin film layer, the photocurable composition of the present invention is applied to the surface of the metal thin film layer, and when it contains a solvent, it is dried and then irradiated with light (such as ultraviolet rays). And a semi-cured or cured method.

In the step (b), a first release film may be provided on the surface of the insulating resin layer.
As a method of providing the first release film on the surface of the insulating resin layer, the first release film having the base material layer and the pressure-sensitive adhesive layer on the surface of the insulating resin layer, the insulating resin layer and the pressure-sensitive adhesive layer are used. The surface of the insulating resin layer by attaching the base material layer of the first release film to the surface of the pressure-sensitive adhesive layer after providing the pressure-sensitive adhesive layer on the surface of the insulating resin layer And a method of providing a first release film.

(Process (c))
In the step (c), a second release film with an adhesive layer in which an adhesive layer is provided on the surface of the second release film is coated with a metal on the surface of the metal thin film layer opposite to the insulating resin layer. You may affix so that a thin film layer and an adhesive bond layer may contact; you may provide an adhesive bond layer directly on the surface of a metal thin film layer. Moreover, after providing an adhesive layer on the surface of the metal thin film layer, a second release film may be attached to the surface of the adhesive layer.

  As a method of providing an adhesive layer on the surface of the second release film or metal thin film layer, an adhesive, a solvent, and optionally conductive particles are provided on the surface of the second release film or metal thin film layer. The method of apply | coating the coating liquid containing and drying is mentioned.

(One Embodiment of Manufacturing Method of Electromagnetic Shielding Film)
Hereinafter, a method for producing the electromagnetic wave shielding film 1 of the first embodiment shown in FIG. 1 will be described with reference to FIGS. 3 and 4.

Step (a):
As shown in FIG. 3, a metal thin film layer 20 is provided by vapor-depositing metal on the surface of the carrier film 100 having the base material layer 102 and the release agent layer 104 on the release agent layer 104 side.

Step (b1):
As shown in FIG. 3, the photocurable composition of the present invention is applied to the surface of the metal thin film layer 20, and when it contains a solvent, it is dried and then irradiated with light (such as ultraviolet rays) to be semi-cured or cured. Thus, the insulating resin layer 10 is provided.

Step (b2):
As shown in FIG. 3, the first release film 30 having the base layer 32 and the adhesive layer 34 is placed on the surface of the insulating resin layer 10 so that the insulating resin layer 10 and the adhesive layer 34 are in contact with each other. paste.

Step (c1):
As shown in FIG. 4, an adhesive 24a, conductive particles 24b, and a solvent are applied to the surface of the second release film 30 having the base layer 42 and the release agent layer 44 on the release agent layer 44 side. The coating liquid for forming an adhesive layer is applied and dried to provide the anisotropic conductive adhesive layer 24 (adhesive layer 22). In this way, a second release film with an adhesive layer is obtained.

Step (c2):
As shown in FIG. 4, the carrier film 100 is peeled from the metal thin film layer 20 in the laminate obtained in the step (b2). In this way, a first release film with an insulating resin layer and a metal thin film layer is obtained.

Step (c3):
As shown in FIG. 4, the first release film with the insulating resin layer and the metal thin film layer and the second release film with the adhesive layer are combined with the metal thin film layer 20 and the anisotropic conductive adhesive layer 24. Are bonded together so that the electromagnetic wave shielding film 1 is obtained.

(Function and effect)
In the electromagnetic wave shielding film of the present invention described above, since the insulating resin layer is the coating film of the present invention, the insulating resin layer is sufficient even though it is a cured product of a photocurable composition containing a colorant. Have good hardness and flame retardancy.

(Other embodiments)
The electromagnetic wave shielding film of the present invention has an insulating resin layer, a metal thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the side opposite to the insulating resin layer of the metal thin film layer. What is necessary is just the coating film of this invention, and is not limited to embodiment of the example of illustration.
For example, the insulating resin layer may be two or more layers.
The first release film may have a release agent layer instead of the pressure-sensitive adhesive layer.
The second release film may have an adhesive layer instead of the release agent layer.
The first release film or the second release film may have only the base material layer without the pressure-sensitive adhesive layer or the release agent layer.
When the insulating resin layer has sufficient flexibility and strength, the first release film may be omitted.
When the tackiness of the surface of the adhesive layer is small, the second release film may be omitted.

<Printed wiring board with electromagnetic shielding film>
FIG. 5 is a cross-sectional view showing an embodiment of a printed wiring board with an electromagnetic wave shielding film of the present invention.
The flexible printed wiring board 2 with an electromagnetic wave shielding film includes a flexible printed wiring board 50, an insulating film 60, and the electromagnetic wave shielding film 1 of the first embodiment.
The flexible printed wiring board 50 has a printed circuit 54 provided on at least one side of a base film 52.
The insulating film 60 is provided on the surface of the flexible printed wiring board 50 on the side where the printed circuit 54 is provided.
The anisotropic conductive adhesive layer 24 of the electromagnetic wave shielding film 1 is bonded to the surface of the insulating film 60. The anisotropic conductive adhesive layer 24 is electrically connected to the printed circuit 54 through a through hole (not shown) formed in the insulating film 60.
In the flexible printed wiring board 2 with an electromagnetic wave shielding film, the second release film 40 is peeled from the anisotropic conductive adhesive layer 24.
When the first release film 30 becomes unnecessary in the flexible printed wiring board 2 with the electromagnetic wave shielding film, the first release film 30 is peeled off from the insulating resin layer 10.

In the vicinity of the printed circuit 54 (signal circuit, ground circuit, ground layer, etc.) excluding the portion having the through hole, the metal thin film layer 20 of the electromagnetic wave shielding film 1 is provided with the insulating film 60 and the anisotropic conductive adhesive layer 24. Are arranged opposite to each other.
The separation distance between the printed circuit 54 excluding the portion having the through hole and the metal thin film layer 20 is substantially equal to the sum of the thickness of the insulating film 60 and the thickness of the anisotropic conductive adhesive layer 24. The separation distance is preferably 30 μm or more and 200 μm or less, and more preferably 60 μm or more and 200 μm or less. When the separation distance is smaller than 30 μm, the impedance of the signal circuit is lowered. Therefore, in order to have a characteristic impedance such as 100Ω, the line width of the signal circuit has to be reduced, and the variation in the line width causes the variation in the characteristic impedance. Thus, the reflection resonance noise due to the impedance mismatch is easily applied to the electric signal. When the separation distance is larger than 200 μm, the flexible printed wiring board 2 with the electromagnetic wave shielding film becomes thick and the flexibility is insufficient.

(Flexible printed wiring board)
The flexible printed wiring board 50 is a printed circuit (a power circuit, a ground circuit, a ground layer, etc.) formed by processing a copper foil of a copper clad laminate into a desired pattern by a known etching method.
As the copper-clad laminate, one or both surfaces of the base film 52 are bonded with copper foil via an adhesive layer (not shown); a resin solution or the like that forms the base film 52 is cast on the surface of the copper foil And the like.
Examples of the material for the adhesive layer include epoxy resin, polyester, polyimide, polyamideimide, polyamide, phenol resin, urethane resin, acrylic resin, and melamine resin.
The thickness of the adhesive layer is preferably 0.5 μm or more and 30 μm or less.

(Base film)
The base film 52 is preferably a heat resistant film, more preferably a polyimide film or a liquid crystal polymer film, and even more preferably a polyimide film.
The surface resistance of the base film 52 is preferably 1 × 10 ⁶ Ω or more from the viewpoint of electrical insulation. The surface resistance of the base film 52 is preferably 1 × 10 ¹⁹ Ω or less from a practical point of view.
The thickness of the base film 52 is preferably 5 μm or more and 200 μm or less, more preferably 6 μm or more and 25 μm or less, and more preferably 10 μm or more and 25 μm or less from the viewpoint of flexibility.

(Printed circuit)
Examples of the copper foil constituting the printed circuit 54 (signal circuit, ground circuit, ground layer, etc.) include rolled copper foil, electrolytic copper foil, and the like, and rolled copper foil is preferred from the viewpoint of flexibility.
The thickness of the copper foil is preferably 1 μm or more and 50 μm or less, and more preferably 18 μm or more and 35 μm or less.
An end (terminal) in the length direction of the printed circuit 54 is not covered with the insulating film 60 or the electromagnetic wave shielding film 1 for solder connection, connector connection, component mounting, or the like.

(Insulating film)
The insulating film 60 is obtained by forming an adhesive layer (not shown) on one surface of an insulating film body (not shown) by applying an adhesive, attaching an adhesive sheet, or the like.
The surface resistance of the insulating film body is preferably 1 × 10 ⁶ Ω or more from the viewpoint of electrical insulation. The surface resistance of the insulating film body is preferably 1 × 10 ¹⁹ Ω or less from a practical point of view.
As an insulating film main body, the film which has heat resistance is preferable, a polyimide film and a liquid crystal polymer film are more preferable, and a polyimide film is further more preferable.
The thickness of the insulating film body is preferably 1 μm to 100 μm, and more preferably 3 μm to 25 μm from the viewpoint of flexibility.
Examples of the material for the adhesive layer include epoxy resin, polyester, polyimide, polyamideimide, polyamide, phenol resin, urethane resin, acrylic resin, melamine resin, polystyrene, and polyolefin. The epoxy resin may contain a rubber component (carboxy-modified nitrile rubber or the like) for imparting flexibility.
The thickness of the adhesive layer is preferably 1 μm or more and 100 μm or less, and more preferably 1.5 μm or more and 60 μm or less.

  The shape of the opening of the through hole is not particularly limited. Examples of the shape of the opening of the through hole 62 include a circle, an ellipse, and a quadrangle.

<Method for producing printed wiring board with electromagnetic shielding film>
The manufacturing method of the printed wiring board with an electromagnetic wave shielding film of this invention is a method which has the following process (d)-(g).
Step (d): A step of providing an insulating film on the surface of the printed wiring board on which the printed circuit is provided to obtain a printed wiring board with an insulating film.
Step (e): When the electromagnetic wave shielding film has the second release film, after peeling the second release film from the electromagnetic wave shielding film, the printed wiring board with the insulating film and the electromagnetic wave shielding film are separated from the insulating film. A process of obtaining a printed wiring board with an electromagnetic wave shielding film by pressing the adhesive layer on the surface of the insulating film by pressing the adhesive layer so that the adhesive layer is in contact with the surface of the insulating film.
Step (f): When the electromagnetic wave shielding film has the first release film, the first release film is removed from the electromagnetic wave shielding film when the first release film becomes unnecessary after the step (e). The process of peeling.
Step (g): When the adhesive contained in the adhesive layer is a thermosetting adhesive, it is bonded between step (e) and step (f) or after step (f) as necessary. A step of fully curing the agent layer.

  Hereinafter, a method for producing a flexible printed wiring board with an electromagnetic wave shielding film will be described with reference to FIG.

(Process (d))
As shown in FIG. 6, an insulating film 60 in which a through hole 62 is formed at a position corresponding to the printed circuit 54 is overlaid on the flexible printed wiring board 50, and an adhesive layer of the insulating film 60 is placed on the surface of the flexible printed wiring board 50. A flexible printed wiring board 3 with an insulating film is obtained by bonding (not shown) and curing the adhesive layer. The adhesive layer of the insulating film 60 may be temporarily bonded to the surface of the flexible printed wiring board 50, and the adhesive layer may be fully cured in the step (g).
Adhesion and curing of the adhesive layer are performed by, for example, hot pressing with a press machine (not shown) or the like.

(Process (e))
As shown in FIG. 6, the electromagnetic wave shielding film 1 from which the second release film 40 has been peeled is stacked and pressed (preferably hot pressed) on the flexible printed wiring board 3 with an insulating film. The flexible printed wiring board 2 with an electromagnetic wave shielding film in which the anisotropic conductive adhesive layer 24 is pressure-bonded to the surface and the anisotropic conductive adhesive layer 24 is electrically connected to the printed circuit 54 through the through hole 62. Get.

The anisotropic conductive adhesive layer 24 is bonded by, for example, hot pressing with a press machine (not shown) or the like.
The hot pressing time is preferably 20 seconds to 60 minutes, more preferably 30 seconds to 30 minutes.
The temperature of the hot press (the temperature of the hot platen of the press machine) is preferably 140 ° C. or higher and 190 ° C. or lower, and more preferably 150 ° C. or higher and 175 ° C. or lower.
The pressure of the hot press is preferably 0.5 MPa or more and 20 MPa or less, and more preferably 1 MPa or more and 16 MPa or less.

(Process (f))
As shown in FIG. 6, when the first release film 30 becomes unnecessary, the first release film 30 is peeled from the insulating resin layer 10.

(Function and effect)
The flexible printed wiring board with an electromagnetic wave shielding film of the present invention described above has the electromagnetic wave shielding film of the present invention, and therefore is an electromagnetic wave shielding film despite being a cured product of a photocurable composition containing a colorant. The insulating resin layer has sufficient hardness and flame retardancy.

(Other embodiments)
The printed wiring board with an electromagnetic wave shielding film in the present invention is a printed wiring board, an insulating film adjacent to the surface of the printed wiring board on which a printed circuit is provided, and an adhesive layer adjacent to the insulating film of the present invention. As long as it has an electromagnetic wave shielding film, it is not limited to the illustrated embodiment.
For example, the flexible printed wiring board may have a ground layer on the back side. The flexible printed wiring board may have a printed circuit on both sides, and an insulating film and an electromagnetic wave shielding film may be attached to both sides.
Instead of the flexible printed wiring board, a rigid printed board having no flexibility may be used.
Instead of the electromagnetic shielding film 1 of the first embodiment, the electromagnetic shielding film 1 of the second embodiment or the like may be used.

  Examples are shown below. In addition, this invention is not limited to an Example.

(Pencil hardness)
Based on JIS K 5600-5-4: 1999 (corresponding international standard ISO 15184: 1996), the pencil hardness of the surface of the insulating resin layer was determined using Uni 6B-6H manufactured by Mitsubishi Pencil Co., Ltd.

(Combustion test)
A flame of a gas burner was brought into contact with the lower end of the sample held vertically for 10 seconds, and the duration of burning was measured.

Example 1
As a coating liquid for forming an insulating resin layer (photocurable composition), a solution of a compound having a (meth) acryloyl group (manufactured by Asia, EXCELATE RUA-054, acrylic polymer acrylate, solid content: 73% by mass, solvent : 100 g of butyl acetate, methyl isobutyl ketone), 2.92 g of phosphoric radical photopolymerization initiator (BASF, Irgacure (registered trademark) TPO), black dye (Orient Chemicals, ORIPACS (registered trademark)) B-20, an azo compound chromium complex) was added.

  As an adhesive layer-forming coating solution, 100 g of vinyl acetate resin solution (made by Showa Denko KK, Vinylol (registered trademark) K-2S, solid content: 15 mass, solvent: methyl isobutyl ketone, methyl ethyl ketone, methanol) in copper powder What mixed 4.5 g of (average particle diameter: 8 micrometers) was prepared.

Step (b1):
Laminated body provided with a metal thin film layer on the surface of a carrier film (manufactured by Toray KP Film Co., Ltd., KP Seduce (registered trademark), copper foil with a release layer, copper foil thickness: 0.5 μm, copper foil surface resistance: A coating liquid for forming an insulating resin layer was applied to the surface of a metal thin film layer of 0.015Ω and PET thickness: 50 μm using a # 4 bar coater. The coating film was dried at 100 ° C. for 1 minute, and then irradiated with ultraviolet rays of 400 mJ to provide an insulating resin layer (thickness: 10 μm, surface resistance: 1.0 × 10 ¹² Ω or more) on the surface of the metal thin film layer. .

Step (b2):
On the surface of the insulating resin layer, a first release film (manufactured by Panac, Panaprotect (registered trademark) GN, adhesive film, adhesive strength: 0.49 N / cm, PET thickness: 75 μm), and insulating resin layer The laminate was obtained by pasting so that the adhesive layer was in contact.

Step (c1):
On the surface of the second release film (manufactured by Panac, Panapeel (registered trademark) SM-1, release film, PET thickness: 50 μm) on the release agent layer side, a coating solution for forming an adhesive layer is used as a comma. It was applied at a thickness of 25 μm using a coater. The coating film was dried at 100 ° C. for 1 minute, provided with an anisotropic conductive adhesive layer (thickness: 10 μm, surface resistance: 1.0 × 10 ¹² Ω or more), and a second release film with an adhesive layer Got.

Step (c2):
In the laminate obtained in the step (b2), the carrier film was peeled from the metal thin film layer to obtain a first release film with an insulating resin layer and a metal thin film layer.

Step (c3):
The first release film with the insulating resin layer and the metal thin film layer and the second release film with the adhesive layer are bonded so that the metal thin film layer and the anisotropic conductive adhesive layer are in contact with each other, and the electromagnetic wave shield A film was obtained.

Step (d):
An insulating adhesive composition is applied to the surface of a 25 μm thick polyimide film (insulating film body) so that the dry film thickness is 25 μm, an adhesive layer is formed, and an insulating film (thickness: 50 μm) is formed. Obtained. A through hole (hole diameter: 150 μm) was formed at a position corresponding to the ground of the printed circuit.

A flexible printed wiring board having a printed circuit formed on the surface of a polyimide film (base film) having a thickness of 12 μm was prepared.
An insulating film was affixed to the flexible printed wiring board by hot pressing to obtain a flexible printed wiring board with an insulating film.

Step (e):
The electromagnetic wave shielding film from which the second release film is peeled is overlapped on the flexible printed wiring board with the insulating film, and hot pressing is performed for 1 minute at a hot platen temperature of 180 ° C. and a load of 3 N using a hot press apparatus. An anisotropic conductive adhesive layer was adhered to the surface.

Step (f):
The 1st release film was peeled from the insulating resin layer, and the flexible printed wiring board with an electromagnetic wave shielding film was obtained.
The pencil hardness of the surface of the insulating resin layer was determined. A combustion test was conducted on a flexible printed wiring board with an electromagnetic wave shielding film. The results are shown in Table 1.

(Example 2)
Electromagnetic wave shielding in the same manner as in Example 1, except that the phosphorous radical polymerization initiator Irgacure (registered trademark) TPO was changed to the phosphorous radical radical polymerization initiator Irgacure (registered trademark) 819 (manufactured by BASF). A flexible printed wiring board with a film was obtained.
The pencil hardness of the surface of the insulating resin layer was determined. A combustion test was conducted on a flexible printed wiring board with an electromagnetic wave shielding film. The results are shown in Table 1.

(Comparative Example 1)
An electromagnetic wave was produced in the same manner as in Example 1 except that Irgacure (registered trademark) TPO, which is a phosphorus photoradical polymerization initiator, was changed to Irgacure (registered trademark) 184 (manufactured by BASF), an alkylphenone photoradical polymerization initiator. A flexible printed wiring board with a shield film was obtained.
The pencil hardness of the surface of the insulating resin layer was determined. A combustion test was conducted on a flexible printed wiring board with an electromagnetic wave shielding film. The results are shown in Table 1.

The coating film made of the cured product of the photocurable composition of the present invention is useful as an insulating resin layer (protective layer) in an electromagnetic wave shielding film, an insulating film in a printed wiring board, and the like.
The electromagnetic wave shielding film of the present invention is useful as an electromagnetic wave shielding member in flexible printed wiring boards for electronic devices such as smartphones, mobile phones, optical modules, digital cameras, game machines, notebook computers, and medical devices.

1 electromagnetic shielding film,
2 Flexible printed wiring board with electromagnetic shielding film,
3 Flexible printed wiring board with insulating film,
10 Insulating resin layer,
20 metal thin film layer,
22 adhesive layer,
24 anisotropic conductive adhesive layer,
24a adhesive,
24b conductive particles,
26 isotropic conductive adhesive layer,
26a adhesive,
26b conductive particles,
30 First release film,
32 base material layer,
34 adhesive layer,
40 Second release film,
42 base material layer,
44 release agent layer,
50 Flexible printed wiring boards,
52 Base film,
54 printed circuit,
60 insulation film,
62 through hole,
100 carrier film,
102 base material layer,
104 Release agent layer.

Claims (14)

  A photocurable composition comprising a compound having a polymerizable carbon-carbon unsaturated bond, a phosphorus-based radical photopolymerization initiator, and a colorant.   The photocurable composition according to claim 1, wherein the compound having a polymerizable carbon-carbon unsaturated bond is a compound having a (meth) acryloyl group.   The photocurable composition according to claim 2, wherein the compound having a (meth) acryloyl group is an acrylic polymer acrylate.   The photocurable composition according to any one of claims 1 to 3, further comprising a solvent.   The photocurable composition according to any one of claims 1 to 4, wherein the colorant is a black colorant.   The photocurable composition according to claim 5, wherein the black colorant is a carbon black pigment.   The photocurable composition according to claim 5, wherein the black colorant is an azo black dye. The photocurable property according to any one of claims 1 to 7, wherein the phosphorus-based radical photopolymerization initiator is a compound represented by the following formula (1) or a compound represented by the following formula (2). Composition.

  The coating film which consists of hardened | cured material of the photocurable composition as described in any one of Claims 1-8.   The manufacturing method of the coating film characterized by apply | coating the photocurable composition as described in any one of Claims 1-8 on the surface of a base material, and irradiating light to the said photocurable composition. An insulating resin layer;
A metal thin film layer adjacent to the insulating resin layer;
An electromagnetic wave shielding film having an adhesive layer adjacent to the side opposite to the insulating resin layer of the metal thin film layer,
An electromagnetic wave shielding film, wherein the insulating resin layer is the coating film according to claim 9.   The electromagnetic wave shielding film according to claim 11, wherein the adhesive layer is an anisotropic conductive adhesive layer. A printed wiring board provided with a printed circuit on at least one side of the substrate;
An insulating film adjacent to the surface of the printed wiring board on which the printed circuit is provided;
The printed wiring board with an electromagnetic wave shielding film having the electromagnetic wave shielding film according to claim 11 or 12, wherein the adhesive layer is provided so as to be adjacent to the insulating film. A method for producing a printed wiring board with an electromagnetic wave shielding film according to claim 13,
A method for producing a printed wiring board with an electromagnetic wave shielding film, wherein the adhesive layer is pressure-bonded to the surface of the insulating film.

Images