JP2020009922A - Electromagnetic wave shielding film, method of manufacturing the same, and printed wiring board with electromagnetic wave shielding film - Google Patents

Abstract

To provide an electromagnetic wave shielding film having high adhesion between an insulating resin layer and a conductive layer.SOLUTION: An electromagnetic wave shielding film 1 of the present invention includes an insulating resin layer 10 and a conductive layer 20 adjacent to the insulating resin layer 10. The insulating resin layer 10 contains an insulating resin and one or more nitrogen-containing compounds selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound. The conductive layer 20 has a metal thin film layer 22 in contact with the insulating resin layer 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic wave shielding film, a method for manufacturing the same, and a printed wiring board with an electromagnetic wave shielding film.

To shield electromagnetic noise from the outside and prevent leakage of electromagnetic noise generated from the printed wiring board, an electromagnetic shielding film with an insulating resin layer and a conductive layer is printed via an insulating film (coverlay film). It may be provided on the surface of a wiring board (for example, see Patent Document 1).
Electromagnetic wave shielding film, for example, on one side of the carrier film, apply a coating containing a thermosetting resin, a curing agent, and a solvent, and then form an insulating resin layer by drying, and form a conductive layer on the surface of the insulating resin layer. It is manufactured by providing. As the conductive layer, for example, a layer including a metal thin film layer and a conductive adhesive layer may be used.

JP-A-2006-086120

However, in the conventional electromagnetic wave shielding film, the adhesiveness between the insulating resin layer and the metal thin film layer is not sufficient, and the film may be peeled off.
An object of the present invention is to provide an electromagnetic wave shielding film having high adhesion between an insulating resin layer and a metal thin film layer, a method for manufacturing the same, and a printed wiring board with an electromagnetic wave shielding film.

The present invention includes the following aspects.
[1] An insulating resin layer and a conductive layer adjacent to the insulating resin layer, wherein the insulating resin layer is selected from the group consisting of an insulating resin, a triazine compound, a triazole compound, and an imidazole compound. An electromagnetic wave shielding film comprising one or more nitrogen-containing compounds, wherein the conductive layer has a metal thin film layer in contact with the insulating resin layer.
[2] The electromagnetic wave shielding film according to [1], wherein the content of the nitrogen-containing compound in the insulating resin layer is 0.1 to 50 parts by mass based on 100 parts by mass of the insulating resin.
[3] An insulating resin layer and a conductive layer adjacent to the insulating resin layer, wherein the conductive layer is opposite to the metal thin film layer in contact with the insulating resin layer and the metal thin film layer is opposite to the insulating resin layer. A conductive adhesive layer formed on the side surface, wherein the conductive adhesive layer is selected from the group consisting of an adhesive, conductive particles, and a triazine-based compound, a triazole-based compound, and an imidazole-based compound. An electromagnetic wave shielding film containing one or more nitrogen-containing compounds.
[4] The electromagnetic wave shielding film according to [3], wherein the content of the nitrogen-containing compound in the conductive adhesive layer is 0.1 to 50 parts by mass based on 100 parts by mass of the adhesive. .
[5] An insulating resin layer and a conductive layer adjacent to the insulating resin layer, wherein the conductive layer is opposite to the metal thin film layer in contact with the insulating resin layer, and the metal thin film layer is opposite to the insulating resin layer. And a conductive adhesive layer formed on the side surface, wherein the insulating resin layer is an insulating resin and one or two selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound. Containing the above nitrogen-containing compound, wherein the conductive adhesive layer is one or more selected from the group consisting of an adhesive, conductive particles, and a triazine-based compound, a triazole-based compound, and an imidazole-based compound. And a nitrogen-containing compound.
[6] The content of the nitrogen-containing compound in the insulating resin layer is 0.1 to 50 parts by mass with respect to 100 parts by mass of the insulating resin, and the nitrogen-containing compound in the conductive adhesive layer is The electromagnetic wave shielding film according to [5], wherein the content of the compound is 0.1 to 50 parts by mass based on 100 parts by mass of the adhesive.
[7] The electromagnetic wave shielding film according to any one of [1] to [6], wherein the nitrogen-containing compound is a liquid or a solid at room temperature.
[8] The electromagnetic wave shielding film according to any one of [1] to [7], wherein the triazine-based compound is a compound represented by the following formula (1).
[R ¹ , R ² and R ³ in the formula (1) are each independently an arbitrary substituent. ]

[9] The electromagnetic wave shielding film according to [8], wherein R ¹ and R ² in the formula (1) are each independently an amino group or a thiol group.
[10] The electromagnetic wave shielding film according to [8] or [9], wherein R ³ in the formula (1) is a substituent having a trialkoxysilyl group or a substituent having a hydroxy group.
[11] The electromagnetic wave shielding film according to any one of [1] to [10], wherein the triazole-based compound is a compound represented by the following formula (2).
[R ⁴ and R ⁵ in the formula (2) are each independently an arbitrary substituent. ]

[12] The electromagnetic wave shielding film according to [11], wherein R ⁴ in the formula (2) is a methyl group or a carboxy group.
[13] The electromagnetic wave shielding film according to [11] or [12], wherein R ⁵ in the formula (2) is an aminoalkyl group which may be substituted with a hydrogen atom bonded to a nitrogen atom.
[14] The electromagnetic wave shielding film according to any one of [1] to [13], wherein the imidazole-based compound is a compound represented by the following formula (3).
[R ⁶ and R ⁷ in the formula (3) are each independently an arbitrary substituent. ]

[15] The electromagnetic wave shielding film according to [14], wherein R ⁶ in the formula (3) is an alkyl group.
[16] The electromagnetic wave shielding film according to [14] or [15], wherein R ⁷ in the formula (3) is a substituent having a trialkoxysilyl group.
[17] The electromagnetic wave shielding film according to any one of [1] to [16], wherein the metal thin film layer contains copper or silver.
[18] A printed wiring board having a printed circuit provided on at least one surface of a substrate, an insulating film adjacent to a surface of the printed wiring board on which the printed circuit is provided, and the conductive layer being adjacent to the insulating film. A printed wiring board with an electromagnetic wave shielding film, comprising: the electromagnetic wave shielding film according to any one of [1] to [17].
[19] Forming an insulating resin layer from an insulating material containing an insulating resin and one or more nitrogen-containing compounds selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound. And forming a metal thin film layer on one surface of the insulating resin layer.
[20] forming an insulating resin layer from an insulating material containing an insulating resin; forming a metal thin film layer on one surface of the insulating resin layer; Is a conductive adhesive containing an adhesive, conductive particles, and one or more nitrogen-containing compounds selected from the group consisting of triazine compounds, triazole compounds and imidazole compounds on the opposite side. Forming a conductive adhesive layer from an agent.
[21] Forming an insulating resin layer from an insulating material containing an insulating resin and one or more nitrogen-containing compounds selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound. Forming a metal thin film layer on one surface of the insulating resin layer, and, on the surface of the metal thin film layer opposite to the insulating resin layer, an adhesive, conductive particles, a triazine compound, Forming a conductive adhesive layer from a conductive adhesive containing one or more nitrogen-containing compounds selected from the group consisting of a triazole-based compound and an imidazole-based compound, comprising: Method.

The electromagnetic wave shielding film of the present invention and the printed wiring board with the electromagnetic wave shielding film of the present invention have high adhesion between the insulating resin layer and the metal thin film layer.
According to the method for manufacturing an electromagnetic wave shielding film of the present invention, an electromagnetic wave shielding film having high adhesion between the insulating resin layer and the metal thin film layer can be easily manufactured.

It is sectional drawing which shows 1st embodiment of the electromagnetic wave shielding film of this invention. It is sectional drawing which shows 2nd embodiment of the electromagnetic wave shielding film of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows one Embodiment of the printed wiring board with an electromagnetic wave shielding film of this invention. FIG. 4 is a cross-sectional view illustrating a manufacturing process of the printed wiring board with the electromagnetic wave shielding film of FIG. 3.

The following term definitions apply throughout the present description and claims.
The “isotropic conductive adhesive layer” means a conductive adhesive layer having conductivity in a thickness direction and a plane direction.
“Anisotropic conductive adhesive layer” means a conductive adhesive layer having conductivity in the thickness direction and not having conductivity in the plane direction.
The “conductive adhesive layer having no conductivity in the surface direction” means a conductive adhesive layer having a surface resistance of 1 × 10 ⁴ Ω or more.
The average particle diameter of particles is determined by randomly selecting 30 particles from a microscopic image of the particles, measuring the minimum and maximum diameters of each particle, and calculating the median of the minimum and maximum diameters as one particle. It is a value obtained by arithmetically averaging the measured particle diameters of the 30 particles as the diameter. The same applies to the average particle size of the conductive particles.
The thickness of the film (release film, insulating film, etc.) is a value obtained by measuring the thickness at five locations using a contact-type film thickness meter and averaging the measured values. The thickness of the insulating resin layer, the conductive adhesive layer, the metal thin film layer, and the like is a value obtained by observing the cross section of the measurement object using a microscope, measuring the thickness at five points, and averaging the thickness.
The storage elastic modulus is calculated from the stress applied to the measurement target and the detected strain, and is measured as one of the viscoelastic properties using a dynamic viscoelasticity measuring device that outputs as a function of temperature or time.
The 10% compressive strength of the conductive particles is determined by the following formula (α) from the measurement result using a micro compression tester.
C (x) = 2.48P / πd ² (α)
Here, C (x) is 10% compressive strength (MPa), P is test force (N) at the time of 10% displacement of particle diameter, and d is particle diameter (mm).
The surface resistance is measured by using two thin-film metal electrodes (length: 10 mm, width: 5 mm, distance between electrodes: 10 mm) formed by evaporating gold on quartz glass. The resistance between the electrodes is measured by pressing a 10 mm × 20 mm area of the measured object from above the object with a load of 0.049 N and a measuring current of 1 mA or less.
The dimensional ratios in FIGS. 1 to 4 are different from actual ones for convenience of explanation.

《First mode》
<Electromagnetic wave shielding film>
The first embodiment of the electromagnetic wave shielding film of the present invention will be described. The electromagnetic wave shielding film of this embodiment has an insulating resin layer and a conductive layer.

FIG. 1 is a sectional view showing an electromagnetic wave shielding film 1 of the first embodiment, and FIG. 2 is a sectional view showing the electromagnetic wave shielding film 1 of the second embodiment.
In each of the electromagnetic wave shielding films 1 of the first embodiment and the second embodiment, the insulating resin layer 10, the conductive layer 20 adjacent to the insulating resin layer 10, and the insulating resin layer 10 adjacent to the side opposite to the conductive layer 20. And a release film 40 adjacent to the conductive layer 20 on the side opposite to the insulating resin layer 10.
In the electromagnetic wave shielding film 1 of the first embodiment, the conductive layer 20 has a metal thin film layer 22 adjacent to the insulating resin layer 10 and an anisotropic conductive adhesive layer 24 adjacent to the release film 40.
In the electromagnetic wave shielding film 1 of the second embodiment, the conductive layer 20 has a metal thin film layer 22 adjacent to the insulating resin layer 10 and an isotropic conductive adhesive layer 26 adjacent to the release film 40.

(Insulating resin layer)
The insulating resin layer 10 is a resin layer that functions as a protective layer for the conductive layer 20, and contains an insulating resin.
As the insulating resin layer 10, a coating containing a thermosetting resin and a curing agent for forming an insulating resin layer is applied, and a coating formed by semi-curing or curing; a coating containing a thermoplastic resin is applied. A layer formed of a film obtained by melt-molding a composition containing a thermoplastic resin. From the viewpoint of heat resistance at the time of soldering or the like, the insulating resin layer 10 is formed by applying a coating containing a thermosetting resin and a curing agent for forming an insulating resin layer, and then semi-curing or curing the coating. Is preferred. Therefore, as the insulating resin contained in the insulating resin layer 10, a cured product of a thermosetting resin is preferable because the heat resistance becomes higher. The cured product here includes a semi-cured product.

Examples of the thermosetting resin include an epoxy resin, an amide resin, a polyester resin, a phenol resin, an amino resin, an alkyd resin, a urethane resin, a synthetic rubber, and an ultraviolet-curable acrylate resin. One thermosetting resin may be used alone, or two or more thermosetting resins may be used in combination. Among the thermosetting resins, epoxy resins are preferable because of their excellent heat resistance and chemical resistance.
As the curing agent for forming the insulating resin layer, a known curing agent according to the type of the thermosetting resin may be used. When the thermosetting resin is an epoxy resin, it is preferable to use an amine compound as the curing agent for forming the insulating resin layer. The curing of the epoxy resin using the amine compound can appropriately lower the reaction temperature, and can sufficiently cure the epoxy resin by cross-linking, thereby further improving the heat resistance of the insulating resin layer 10. it can.
Examples of the amine compound used as the curing agent for forming the insulating resin layer include an aliphatic amine compound and an aromatic amine compound.
Examples of the aliphatic amine compound include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, diethylaminopropylamine, N-aminoethylpiperazine, mensendiamine, and isophoronediamine.
Examples of the aromatic amine compound include m-xylenediamine, metaphenylenediamine, diaminodiphenylmethane, and the like.
As the curing agent for forming an insulating resin layer such as the amine compound, one kind may be used alone, or two or more kinds may be used in combination.

The insulating resin layer 10 according to the present embodiment contains a nitrogen-containing compound in addition to the insulating resin.
The nitrogen-containing compound is one or more compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds.
The nitrogen-containing compound is preferably liquid or solid at room temperature. Here, the normal temperature refers to a temperature in the range of 20 ° C. ± 15 ° C., that is, 5 ° C. or more and 35 ° C. or less, as defined in JIS Z8703.
If the nitrogen-containing compound is liquid or solid at room temperature, it can be easily mixed with the insulating resin, and the adhesion between the insulating resin layer 10 and the metal thin film layer 22 can be further improved.
The following nitrogen-containing compounds contained in the insulating resin layer 10 may be used alone or in combination of two or more.

The triazine-based compound is triazine (C ₃ H ₃ N ₃ ) or a derivative thereof. A triazine derivative is a compound in which at least one hydrogen atom of triazine is substituted with another substituent.
The triazine-based compound is preferably a compound represented by the above formula (1), since the adhesion between the insulating resin layer 10 and the metal thin film layer 22 can be further improved. R ¹ , R ² and R ³ in the formula (1) are each independently an arbitrary substituent. Examples of the optional substituent include an alkyl group, a hydroxyalkyl group, an aryl group, a benzyl group, an alkoxy group, a hydroxy group, an amino group, a thiol group, a carboxy group, a trialkylsilyl group, a trialkoxysilyl group, and And a substituent having a group.
R ¹ and R ² in the formula (1) each independently represent an amino group (—NH ₂ ) or a thiol group (—SH) in that the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 can be further increased. It is preferred that
From the viewpoint that the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 can be further increased, R ³ in the formula (1) is a trialkoxysilyl group (—Si (OC _n H _{2n + 1} ), and n is an integer of 1 or more) Or a substituent having a hydroxy group (—OH). Here, the substituent having a trialkoxysilyl group is an alkylene group having 3 or more carbon atoms having a trialkoxysilyl group, and the substituent having a hydroxy group is an alkylene group having 3 or more carbon atoms having a hydroxy group. Can be The alkylene group preferably has 10 or less carbon atoms. Specific examples of preferred alkylene groups include, for example, propylene, butylene, pentylene, hexylene, heptylene, nonylene, and decylene. Examples of the trialkoxysilyl group include a trimethoxysilyl group, a triethoxysilyl group, a tripropoxysilyl group, and a tributoxysilyl group, and among them, a triethoxysilyl group is preferable.
In terms of further improving the adhesiveness, R ¹ and R ² in the formula (1) are each independently an amino group or a thiol group, and R ³ is a triethoxysilyl group (—Si (OC ₂ More preferably, it is a substituent having H ₅ ) ₃ ) or a substituent having a hydroxy group.
Examples of the compound in which both R ¹ and R ² in the formula (1) are thiol groups and R ³ is a substituent having a triethoxysilyl group include triethoxysilylpropylaminotriazinedithiol. Is mentioned.

The triazole-based compound is triazole (C ₂ H ₃ N ₃ ) or a derivative thereof. A triazole derivative is a compound in which at least one hydrogen atom of a triazole is substituted with another substituent. Other substituents may combine with each other to form a cyclic structure.
The triazole-based compound is preferably a compound represented by the above formula (2) because the triazole-based compound can further increase the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22. R ⁴ and R ⁵ in the formula (2) are each independently an arbitrary substituent. The optional substituent in the formula (2) is the same as the optional substituent in the formula (1).
R ⁴ in the formula (2) is preferably a methyl group (—CH ₃ ) or a carboxy group (—COOH) from the viewpoint that the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 can be further improved.
From the viewpoint that the adhesion between the insulating resin layer 10 and the metal thin film layer 22 can be further improved, R ⁵ in the formula (2) is an aminoalkyl group (—C _m ) in which a hydrogen atom bonded to a nitrogen atom may be substituted. H _2m NR ⁹ _2, ^{R 9} are each independently a hydrogen atom, an alkyl or hydroxyalkyl group, m is preferably 1 or more is an integer.).
Examples of the alkyl group for R ⁹ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a 2-ethylhexyl group. The hydroxyalkyl group for R ⁹ is —C _n H _n OH (n is an integer of 1 or more), and examples include a hydroxymethyl group, a 1-hydroxyethyl group, and a 1-hydroxypropyl group.
Preferably, m and n are each independently 4 or less.
From the viewpoint of further improving the adhesiveness, it is more preferable that R ⁴ in the formula (2) is a methyl group or a carboxy group, and that R ⁵ is an aminoalkyl group.

The imidazole-based compound is imidazole (C ₃ H ₄ N ₂ ) or a derivative thereof. A derivative of imidazole is a compound in which at least one hydrogen atom of imidazole is substituted with another substituent.
The imidazole-based compound is preferably a compound represented by the above formula (3), since the adhesion between the insulating resin layer 10 and the metal thin film layer 22 can be further improved. R ⁶ and R ⁷ in the formula (3) are each independently an arbitrary substituent. The optional substituent in the formula (3) is the same as the optional substituent in the formula (1).
From the viewpoint that the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 can be further improved, R ⁶ in the formula (3) is preferably an alkyl group. Examples of the alkyl group for R ⁶ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, and the like. From the viewpoint of improving adhesiveness, a methyl group (—CH ₃ ) Is more preferable.
R ⁷ in the formula (3) is preferably a substituent having a trialkoxysilyl group from the viewpoint that the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 can be further improved. Examples of the trialkoxysilyl group include a trimethoxysilyl group, a triethoxysilyl group, a tripropoxysilyl group, and a tributoxysilyl group.
From the viewpoint of improving adhesion, the substituent having a trialkoxysilyl group is preferably a group in which a trialkoxysilyl group is bonded to one end of an alkylene group, and a trimethoxysilyl group is bonded to one end of the alkylene group. More preferably, it is a group to which (—Si (OCH ₃ ) ₃ ) is bonded. Examples of the alkylene group include methylene, ethylene, propylene, butylene and the like.
From the viewpoint of further improving the adhesiveness, it is more preferable that R ⁶ in the formula (3) is a methyl group, and R ⁷ is a group in which a trimethoxysilyl group is bonded to one end of an alkylene group.

The content of the nitrogen-containing compound in the insulating resin layer 10 is preferably 0.1 to 50 parts by mass, and more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the insulating resin. More preferably, there is.
When the content of the nitrogen-containing compound in the insulating resin layer 10 is equal to or more than the lower limit, the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 becomes higher. Can maintain the mechanical physical properties and heat resistance.

The insulating resin layer 10 is used to conceal a printed circuit of a flexible printed wiring board or to provide a printed wiring board with an electromagnetic wave shielding film with a design property. Or it may include both.
As one or both of the coloring agent and the filler, a pigment or a filler is preferable from the viewpoint of weather resistance, heat resistance, and concealing property.From the viewpoint of concealing property of a printed circuit and design, a black pigment or a black pigment is used. Combinations with other pigments or fillers are more preferred.

The insulating resin layer 10 may include a flame retardant.
The insulating resin layer 10 may include other components such as a polymer other than the insulating resin as needed, as long as the effects of the present invention are not impaired.

  The insulating resin layer 10 may be composed of a plurality of insulating resin layers having different compositions. When the insulating resin layer 10 is formed of a plurality of layers, at least a layer in contact with the metal thin film layer 22 contains the nitrogen-containing compound.

The storage elastic modulus at 180 ° C. of the insulating resin layer 10 is preferably 5 × 10 ⁶ Pa or more and 5 × 10 ⁹ Pa or less, more preferably 1 × 10 ⁷ Pa or more and 1 × 10 ⁹ Pa or less. If the storage elastic modulus at 180 ° C. of the insulating resin layer 10 is equal to or more than the lower limit of the above range, the insulating resin layer 10 has appropriate hardness, and the pressure loss in the insulating resin layer 10 during hot pressing is reduced. Can be reduced. As a result, the conductive adhesive layers 24 and 26 and the printed circuit of the flexible printed wiring board are sufficiently bonded to each other, and the conductive adhesive layers 24 and 26 pass through the through holes of the insulating film to print the printed circuit of the flexible printed wiring board. The electric connection is ensured. When the storage elastic modulus at 180 ° C. of the insulating resin layer 10 is equal to or less than the upper limit of the above range, the flexibility of the electromagnetic wave shielding film 1 is improved. As a result, the electromagnetic wave shielding film 1 easily sinks into the through-hole of the insulating film 60, and the conductive adhesive layer is securely electrically connected to the printed circuit of the flexible printed wiring board through the through-hole of the insulating film. You.

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 from 0.1 μm to 30 μm, and more preferably from 0.5 μm to 20 μm. When the thickness of the insulating resin layer 10 is equal to or more than the lower limit of the above range, the insulating resin layer 10 can sufficiently exhibit the function as a protective layer. When the thickness of the insulating resin layer 10 is equal to or less than the upper limit of the above range, the thickness of the electromagnetic wave shielding film 1 can be reduced.

(Conductive layer)
The conductive layer is a layer containing at least a metal and shielding electromagnetic waves.
Specifically, as described above, the conductive layer 20 in the first embodiment includes the metal thin film layer 22 adjacent to the insulating resin layer 10 and the anisotropic conductive adhesive layer 24 adjacent to the release film 40. Have.
The conductive layer 20 in the second embodiment has a metal thin film layer 22 adjacent to the insulating resin layer 10 and an isotropic conductive adhesive layer 26 adjacent to the release film 40.
The conductive layer 20 preferably has the metal thin film layer 22 and the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26 because the electromagnetic wave shielding property is sufficiently high. That is, the conductive layer 20 preferably has two layers, a metal thin film layer and a conductive adhesive layer.

[Metal thin film layer]
The metal thin film layer 22 is a layer made of a metal thin film. Since the metal thin film layer 22 is formed so as to spread in the plane direction, it has conductivity in the plane direction and functions as an electromagnetic wave shielding layer or the like.

  Examples of the metal thin film layer 22 include a vapor deposition film formed by physical vapor deposition (vacuum vapor deposition, sputtering, ion beam vapor deposition, electron beam vapor deposition, etc.) or chemical vapor deposition, a plating film formed by plating, a metal foil, and the like. The conductive layer 20 is preferably a vapor-deposited film or a plated film in terms of excellent conductivity in the plane direction. The conductive layer 20 is more preferably a vapor-deposited film in that the conductive layer 20 can be made thin and has excellent conductivity in the plane direction even if the thickness is thin, and can be easily formed by a dry process. preferable.

Examples of the metal constituting the metal thin film layer 22 include aluminum, silver, copper, gold, and conductive ceramics, and silver or copper is preferable from the viewpoint of electrical conductivity.
Among the metal thin film layers 22, a metal vapor-deposited layer is preferable, and a silver vapor-deposited layer or a copper vapor-deposited layer is more preferable because the electromagnetic wave shielding property is high and the metal thin film layer is easily formed.

  The surface resistance of the metal thin film layer 22 is preferably from 0.001 Ω to 1 Ω, and more preferably from 0.001 Ω to 0.5 Ω. When the surface resistance of the metal thin film layer 22 is equal to or more than the lower limit of the above range, the metal thin film layer 22 can be made sufficiently thin. When the surface resistance of the metal thin film layer 22 is equal to or less 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 22 is preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more and 3 μm or less. When the thickness of the metal thin film layer 22 is 0.01 μm or more, the conductivity in the plane direction is further improved. When the thickness of the metal thin film layer 22 is 0.05 μm or more, the electromagnetic wave noise shielding effect is further improved. When the thickness of the metal thin film layer 22 is equal to or less than the upper limit of the above range, the thickness of the electromagnetic wave shielding film 1 can be reduced. Further, the productivity and flexibility of the electromagnetic wave shielding film 1 are improved.

[Anisotropic conductive adhesive layer]
The anisotropic conductive adhesive layer 24 in the first embodiment has conductivity in the thickness direction, does not have conductivity in the plane direction, and has adhesiveness.
The anisotropic conductive adhesive layer 24 can easily make the conductive adhesive layer thinner and reduce the amount of conductive particles described later. As a result, the electromagnetic wave shielding film 1 can be made thinner, and the electromagnetic wave shielding film 1 becomes flexible. This has the advantage of increasing the performance.

The anisotropic conductive adhesive layer 24 is preferably a thermosetting conductive adhesive layer from the viewpoint of exhibiting heat resistance after curing. The thermosetting anisotropic conductive adhesive layer 24 may be in an uncured state or a B-staged state.
The thermosetting anisotropic conductive adhesive layer 24 includes, for example, a thermosetting adhesive 24a and conductive particles 24b. The thermosetting anisotropic conductive adhesive layer 24 may contain a flame retardant as needed.

Examples of the thermosetting adhesive 24a 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. Epoxy resins are preferred because of their excellent heat resistance. The epoxy resin may include a rubber component (carboxy-modified nitrile rubber, acrylic rubber, etc.) for imparting flexibility, a tackifier, and the like.
The thermosetting adhesive 24a may include a cellulose resin and microfibrils (such as glass fibers) in order to increase the strength of the anisotropic conductive adhesive layer 24 and improve the punching characteristics. The thermosetting adhesive may contain other components as needed as long as the effects of the present invention are not impaired.

  Examples of the conductive particles 24b include particles of metal (silver, platinum, gold, copper, nickel, palladium, aluminum, solder, etc.), graphite powder, fired carbon particles, plated fired carbon particles, and the like. As the conductive particles 24b, the anisotropic conductive adhesive layer 24 has a further appropriate hardness, and the pressure loss in the anisotropic conductive adhesive layer 24 during hot pressing can be further reduced. , Metal particles are preferred, and copper particles are more preferred.

  The 10% compressive strength of the conductive particles 24b is preferably from 30 MPa to 200 MPa, more preferably from 50 MPa to 150 MPa, even more preferably from 70 MPa to 100 MPa. When the 10% compressive strength of the conductive particles is equal to or more than the lower limit of the above range, the pressure applied to the metal thin film layer 22 during the hot pressing is not greatly reduced, and the anisotropic conductive adhesive layer 24 is formed on the insulating film. Through the through hole of the printed circuit board to ensure electrical connection. When the 10% compressive strength of the conductive particles 24b is equal to or less than the upper limit of the above range, the contact with the metal thin film layer 22 is improved, and the electrical connection is ensured.

  The average particle diameter of the conductive particles 24b in the anisotropic conductive adhesive layer 24 is preferably 2 μm or more and 26 μm or less, more preferably 4 μm or more and 16 μm or less. When the average particle diameter of the conductive particles 24b is equal to or more than the lower limit of the above range, the thickness of the anisotropic conductive adhesive layer 24 can be secured, and sufficient adhesive strength can be obtained. When 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 can be secured, and the anisotropic conductive adhesive layer 24 is formed of an insulating film as described later. When pushed into the through hole, the inside of the through hole of the insulating film can be sufficiently filled with the conductive adhesive.

  The proportion of the conductive particles 24b in the anisotropic conductive adhesive layer 24 is preferably 1% by volume or more and 30% by volume or less, preferably 2% by volume or more and 15% by volume of 100% by volume of the anisotropic conductive adhesive layer 24. The following is more preferred. When the ratio of the conductive particles 24b is equal to or more than the lower limit of the above range, the conductivity of the anisotropic conductive adhesive layer 24 becomes good. If the ratio of the conductive particles 24b is equal to or less than the upper limit of the above range, the adhesiveness and fluidity (the ability to follow the shape of the through-hole of the insulating film) of the anisotropic conductive adhesive layer 24 will be good. Further, the flexibility of the electromagnetic wave shielding film 1 is improved.

The anisotropic conductive adhesive layer 24 in this embodiment is one or two selected from the group consisting of a triazine compound, a triazole compound, and an imidazole compound, in addition to the thermosetting adhesive 24a and the conductive particles 24b. The above-mentioned nitrogen-containing compounds may be contained. When the anisotropic conductive adhesive layer 24 contains the nitrogen-containing compound, the adhesiveness between the anisotropic conductive adhesive layer 24 and the metal thin film layer 22 increases. The nitrogen-containing compound contained in the anisotropic conductive adhesive layer 24 is the same as the nitrogen-containing compound contained in the insulating resin layer 10.
The content of the nitrogen-containing compound in the anisotropic conductive adhesive layer 24 is preferably 0.1 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the thermosetting adhesive, and 0.1 part by mass. It is more preferable that the amount is not less than 20 parts by mass.
When the content of the nitrogen-containing compound in the anisotropic conductive adhesive layer 24 is equal to or more than the lower limit, the adhesiveness between the anisotropic conductive adhesive layer 24 and the metal thin film layer 22 becomes higher, and is equal to or less than the upper limit. If so, the properties of the anisotropic conductive adhesive layer 24 as the conductive adhesive can be maintained.

The storage elastic modulus at 180 ° C. of the anisotropic conductive adhesive layer 24 is preferably from 1 × 10 ³ Pa to 5 × 10 ⁷ Pa, more preferably from 5 × 10 ³ Pa to 1 × 10 ⁷ Pa. If the storage elastic modulus at 180 ° C. of the anisotropic conductive adhesive layer 24 is equal to or more than the lower limit of the above range, the anisotropic conductive adhesive layer 24 will have a further appropriate hardness, and when hot pressing is performed. Of the conductive adhesive layer can be reduced. As a result, the conductive adhesive layer and the printed circuit of the printed wiring board are sufficiently adhered to each other, and the anisotropic conductive adhesive layer 24 passes through the through hole of the insulating film to ensure the electric circuit by the printed circuit of the printed wiring board. Connected to. When the storage elastic modulus at 180 ° C. of the conductive adhesive layer is equal to or less than the upper limit of the above range, the flexibility of the electromagnetic wave shielding film 1 is improved. As a result, the electromagnetic wave shielding film 1 easily sinks into the through hole of the insulating film, and the anisotropic conductive adhesive layer 24 is reliably electrically connected to the printed circuit of the printed wiring board through the through hole of the insulating film. Is done.

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. When the surface resistance of the anisotropic conductive adhesive layer 24 is equal to or more than the lower limit of the above range, the content of the conductive particles 24b can be suppressed low.
As long as the surface resistance of the anisotropic conductive adhesive layer 24 is equal to or less than the upper limit of the above range, there is no problem in practical anisotropy.

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

[Isotropic conductive adhesive layer]
The isotropic conductive adhesive layer 26 in the second embodiment has conductivity in the thickness direction and the surface direction, and has adhesiveness.
The isotropic conductive adhesive layer 26 has an advantage that the electromagnetic wave shielding property of the electromagnetic wave shielding film 1 can be further improved.

As the isotropic conductive adhesive layer 26, a thermosetting conductive adhesive layer is preferable because heat resistance can be exhibited after curing. The thermosetting isotropic conductive adhesive layer 26 may be in an uncured state or a B-staged state.
The thermosetting isotropic conductive adhesive layer 26 includes, for example, a thermosetting adhesive 26a and conductive particles 26b. The thermosetting isotropic conductive adhesive layer 26 may include a flame retardant as needed.
The component of the thermosetting adhesive 26a contained in the isotropic conductive adhesive layer 26 and the material of the conductive particles 26b are the same as the component of the thermosetting adhesive 24a contained in the anisotropic conductive adhesive layer 24 and the conductivity. This is the same as the material of the particles 24b.

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

  The proportion of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 50% by volume to 80% by volume, and more preferably 60% by volume to 70% by volume of 100% by volume of the isotropic conductive adhesive layer 26. The following is more preferred. When the ratio of the conductive particles 26b is equal to or more than the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 becomes good. 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 (the ability to follow the shape of the through-hole of the insulating film) of the isotropic conductive adhesive layer 26 are improved. Further, the flexibility of the electromagnetic wave shielding film 1 is improved.

The isotropic conductive adhesive layer 26 in this embodiment is one or two selected from the group consisting of a triazine compound, a triazole compound, and an imidazole compound, in addition to the thermosetting adhesive 26a and the conductive particles 26b. The above-mentioned nitrogen-containing compounds may be contained. When the isotropic conductive adhesive layer 26 contains the nitrogen-containing compound, the adhesiveness between the isotropic conductive adhesive layer 26 and the metal thin film layer 22 increases. The nitrogen-containing compound contained in the isotropic conductive adhesive layer 26 is the same as the nitrogen-containing compound contained in the insulating resin layer 10.
The content of the nitrogen-containing compound in the isotropic conductive adhesive layer 26 is preferably 0.1 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the thermosetting adhesive, and 0.1 part by mass. It is more preferable that the amount is not less than 20 parts by mass.
When the content of the nitrogen-containing compound in the isotropic conductive adhesive layer 26 is equal to or more than the lower limit, the adhesiveness between the isotropic conductive adhesive layer 26 and the metal thin film layer 22 becomes higher, and is equal to or less than the upper limit. If so, the properties of the isotropic conductive adhesive layer 26 as the conductive adhesive can be maintained.

The storage elastic modulus at 180 ° C. of the isotropic conductive adhesive layer 26 is preferably from 1 × 10 ³ Pa to 5 × 10 ⁷ Pa, and more preferably from 5 × 10 ³ Pa to 1 × 10 ⁷ Pa. The reason why the above range is preferable is the same as that of the anisotropic conductive adhesive layer 24.

  The surface resistance of the isotropic conductive adhesive layer 26 is preferably 0.05Ω or more and 2.0Ω or less, more preferably 0.1Ω or more and 1.0Ω or less. When the surface resistance of the isotropic conductive adhesive layer 26 is equal to or more than the lower limit of the above range, the content of the conductive particles 26b is suppressed low, the viscosity of the conductive adhesive does not become too high, and the coating property is low. It will be even better. In addition, the fluidity of the isotropic conductive adhesive layer 26 (following the shape of the through hole of the insulating film) can be further secured. When the surface resistance of the isotropic conductive adhesive layer 26 is equal to or less than the upper limit of the above range, the entire surface of the isotropic conductive adhesive layer 26 has uniform conductivity.

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

(Carrier film)
The carrier film 30 is a support that reinforces and protects the insulating resin layer 10 and the conductive layer 20, and improves the handling properties of the electromagnetic wave shielding film 1. In particular, when a thin film, specifically, a film having a thickness of 20 μm or less is used as the insulating resin layer 10, the presence of the carrier film 30 can prevent the insulating resin layer 10 from breaking.
The carrier film 30 is peeled off from the insulating resin layer 10 after attaching the electromagnetic wave shielding film 1 to a printed wiring board or the like.

  The carrier film 30 used in the present embodiment has a carrier film main body 32 and a release agent layer 34 provided on the surface of the carrier film main body 32 on the insulating resin layer 10 side.

  As the resin material of the carrier film main body 32, polyethylene terephthalate (hereinafter, also sometimes referred to as “PET”), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, ethylene -Vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer and the like. As the resin material, PET is preferable in terms of heat resistance (dimensional stability) and cost when manufacturing the electromagnetic wave shielding film 1.

The carrier film main body 32 may include one or both of a colorant (a pigment, a dye, and the like) and a filler.
As one or both of the coloring agent and the filler, those having a color different from that of the insulating resin layer 10 can be clearly distinguished from the insulating resin layer 10 and the carrier film 30 is easily peeled off after hot pressing. Preference is given to white pigments, fillers, or combinations of white pigments with other pigments or fillers.

The storage elastic modulus at 180 ° C. of the carrier film main body 32 is preferably 8 × 10 ⁷ Pa or more and 5 × 10 ⁹ Pa, more preferably 1 × 10 ⁸ Pa or more and 8 × 10 ⁸ Pa. If the storage elastic modulus at 180 ° C. of the carrier film main body 32 is equal to or more than the lower limit of the above range, the carrier film 30 has an appropriate hardness, and the pressure loss in the carrier film 30 during hot pressing can be reduced. . When the storage elastic modulus at 180 ° C. of the carrier film main body 32 is equal to or less than the upper limit of the above range, the flexibility of the carrier film 30 is improved.

  The thickness of the carrier film main body 32 is preferably 3 μm or more and 75 μm or less, more preferably 12 μm or more and 50 μm or less. When the thickness of the carrier film main body 32 is equal to or larger than the lower limit of the above range, the handling property of the electromagnetic wave shielding film 1 is improved. If the thickness of the carrier film main body 32 is equal to or less than the upper limit of the above range, the conductive adhesive layer (the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 24) of the electromagnetic wave shielding film 1 is formed on the surface of the insulating film. When heat-pressing 26), heat is easily transmitted to the conductive adhesive layer.

The release agent layer 34 is formed, for example, by treating the surface of the carrier film main body 32 with a release agent. When the carrier film 30 has the release agent layer 34, the carrier film 30 is easily peeled from the insulating resin layer 10, and the insulating resin layer 10 is not easily broken. Therefore, the carrier film 30 can sufficiently fulfill the role of a protective film.
As the release agent for forming the release agent layer 34, a known silicone-based or non-silicone-based release agent may be used.

  The thickness of the carrier film 30 is preferably 25 μm or more and 125 μm or less, more preferably 38 μm or more and 100 μm or less. When the thickness of the carrier film 30 is equal to or more than the lower limit of the above range, the handling property of the electromagnetic wave shielding film 1 becomes good. When the thickness of the carrier film 30 is equal to or less than the upper limit of the above range, heat is easily transmitted to the conductive adhesive layer when the conductive adhesive layer of the electromagnetic wave shielding film 1 is hot-pressed on the surface of the insulating film.

(Release film)
The release film 40 protects the conductive adhesive layer and improves the handleability of the electromagnetic wave shielding film 1. The release film 40 is separated from the conductive adhesive layer (the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26) before the electromagnetic wave shielding film 1 is attached to a printed wiring board or the like.
The release film 40 has, for example, a release film main body 42 and a release agent layer 44 provided on the surface of the release film main body 42 on the conductive adhesive layer side.

Examples of the resin material of the release film main body 42 include the same as the resin material of the carrier film main body 32.
The release film main body 42 may include a coloring agent, a filler, and the like.
The thickness of the release film main body 42 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 150 μm or less, and even more preferably 25 μm or more and 100 μm or less.

The release agent layer 44 is formed by treating the surface of the release film main body 42 with a release agent. When the release film 40 has the release agent layer 44, when the release film 40 is released from the conductive adhesive layer, the release film 40 is easily released, and the conductive adhesive layer is not easily broken. .
A known release agent may be used as the release agent.

  The thickness of the release agent layer 44 is preferably 0.05 μm or more and 30 μm or less, and more preferably 0.1 μm or more and 20 μm or less. When the thickness of the release agent layer 44 is within the above range, the release film 40 is more easily peeled.

(Thickness of electromagnetic wave shielding film)
The thickness (excluding the carrier film 30 and the release film 40) of the electromagnetic wave shielding film 1 is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less. If the thickness of the electromagnetic wave shielding film 1 that does not include the carrier film 30 and the release film 40 is equal to or greater than the lower limit of the above range, it is difficult to break when the carrier film 30 is peeled, and is equal to or less than the upper limit of the above range. The printed wiring board with the electromagnetic wave shielding film can be made thin.

<Production method of electromagnetic wave shielding film>
The first embodiment of the method for producing an electromagnetic wave shielding film of the present invention will be described. The method for manufacturing an electromagnetic wave shielding film of the first aspect includes forming an insulating resin layer from an insulating material containing an insulating resin and a nitrogen-containing compound, and forming a metal thin film layer on one surface of the insulating resin layer. Forming. As the nitrogen-containing compound, one or more selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound is used.
Hereinafter, a specific method for producing an electromagnetic wave shielding film will be described.

As a method for manufacturing the electromagnetic wave shielding film of the first embodiment, for example, the following method (A1), method (A2) or method (A3) can be mentioned.
As a method of manufacturing the electromagnetic wave shielding film of the second embodiment, for example, the following method (B1), method (B2) or method (B3) can be mentioned.

The method (A1) is specifically a method including the following steps (A1-1) to (A1-4).
Step (A1-1): Forming the insulating resin layer 10 on one surface of the carrier film 30.
Step (A1-2): Forming the metal thin film layer 22 on the surface of the insulating resin layer 10 opposite to the carrier film 30.
Step (A1-3): Forming an anisotropic conductive adhesive layer 24 on the surface of the metal thin film layer 22 opposite to the insulating resin layer 10.
Step (A1-4): Laminating the release film 40 on the surface of the anisotropic conductive adhesive layer 24 opposite to the metal thin film layer 22.
Hereinafter, each step of the method (A1) will be described in detail.

Examples of a method for forming the insulating resin layer 10 in the step (A1-1) include the following method.
On the surface of the carrier film 30 on the release agent layer 34 side, an insulating resin layer forming paint containing a thermosetting resin, an insulating resin layer forming hardener, and a nitrogen-containing compound is applied and semi-cured or cured. Method.
A method in which a coating material for forming an insulating resin layer containing a thermoplastic resin and a nitrogen-containing compound is applied to the surface of the carrier film 30 on the side of the release agent layer 34 and dried.
A method of directly laminating a film formed by extrusion molding of a composition containing a thermoplastic resin and a nitrogen-containing compound on the surface of the carrier film 30 on the side of the release agent layer 34.
Among the above methods, from the viewpoint of heat resistance during soldering or the like, a thermosetting resin, a curing agent for forming an insulating resin layer, and a nitrogen-containing compound are applied to the surface of the carrier film 30 on the release agent layer 34 side. It is preferable to apply a coating material for forming an insulating resin layer containing the composition and semi-cur or cure the composition.
When applying an insulating resin layer-forming paint containing a thermosetting resin, an insulating resin layer-forming curing agent, and a nitrogen-containing compound, the amount of the insulating resin layer-forming curing agent varies depending on the type of the curing agent. The amount is preferably from 0.1 to 80 parts by mass, more preferably from 1 to 70 parts by mass, based on 100 parts by mass of the thermosetting resin. When the amount of the curing agent for forming the insulating resin layer is equal to or more than the lower limit, the heat resistance of the cured product can be further increased. Can be secured sufficiently.

The coating material for forming an insulating resin layer may contain a solvent, if necessary.
Examples of the solvent include alcohol solvents, ketone solvents, ester solvents, aromatic hydrocarbon solvents, and nitrogen atom-containing solvents. One kind of the solvent may be used alone, or two or more kinds may be used in combination.
Examples of the alcohol-based solvent include a monol having one hydroxy group and a diol having two hydroxy groups. Examples of the monol include isopropanol, n-butanol, t-butanol, allyl alcohol and the like. Examples of the diol include ethylene glycol, diethylene glycol, propylene glycol, and butanediol (1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol) and the like.
Examples of the ether solvent include propylene glycol monoalkyl ethers such as diethyl ether, dimethyl ether, ethylene glycol, propylene glycol, and propylene glycol monomethyl ether, and propylene glycol dialkyl ether.
Examples of the ketone solvent include diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone, diacetone alcohol and the like.
Examples of the ester solvent include ethyl acetate, propyl acetate, butyl acetate and the like.
Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, ethylbenzene, propylbenzene, and isopropylbenzene.
Examples of the nitrogen atom-containing solvent include N-methylpyrrolidone, dimethylacetamide, dimethylformamide and the like.

Examples of the coating method of the paint include a die coater, a gravure coater, a roll coater, a curtain flow coater, a spin coater, a bar coater, a reverse coater, a kiss coater, a fountain coater, a rod coater, an air doctor coater, a knife coater, and a blade coater. A method using various coaters such as a cast coater and a screen coater can be applied.
When the thermosetting resin is semi-cured or cured, it may be heated using a heater such as a heater or an infrared lamp.

In the step (A1-2), the metal thin film layer 22 is formed on the surface of the insulating resin layer 10 opposite to the carrier film 30.
Examples of the method of forming the metal thin film layer 22 include a method of forming a deposited film by physical vapor deposition, CVD (chemical vapor deposition), a method of forming a plated film by plating, and a method of attaching a metal foil. From the viewpoint that the metal thin film layer 22 can be easily thinned and the metal thin film layer 22 can be easily formed by a dry process, a method of forming a vapor deposition film by physical vapor deposition or CVD is more preferable, and a method of forming a vapor deposition film by physical vapor deposition is preferable. More preferred. From the viewpoint that a roll-to-roll processing method can be applied, vacuum deposition is particularly preferable among physical vapor depositions.

In the step (A1-3), a conductive adhesive paint is applied to the surface of the metal thin film layer 22 opposite to the insulating resin layer 10 to form the anisotropic conductive adhesive layer 24.
The conductive adhesive paint contains a thermosetting adhesive 24a, conductive particles 24b, and a solvent.
The anisotropic conductive adhesive layer 24 is formed by evaporating the solvent from the applied conductive adhesive paint.
Examples of the solvent contained in the conductive adhesive paint 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). And alcohol (methanol, ethanol, isopropanol, butanol, propylene glycol monomethyl ether, propylene glycol, etc.).
The conductive adhesive paint may contain one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds.
The method for applying the conductive adhesive is the same as the method for applying the paint in the step (A1-1).
The anisotropic conductive adhesive layer 24 is formed by evaporating the solvent from the applied conductive adhesive paint.

In the step (A1-4), the release film 40 is attached to the surface of the anisotropic conductive adhesive layer 24 opposite to the metal thin film layer 22, and the release agent layer 44 is attached to the anisotropic conductive adhesive layer 24. The layers are laminated so as to be in contact with each other.
After laminating the release film 40 on the anisotropic conductive adhesive layer 24, a laminate composed of the carrier film 30, the insulating resin layer 10, the metal thin film layer 22, the anisotropic conductive adhesive layer 24 and the release film 40 In addition, a pressure treatment for improving the adhesion between the layers may be performed.
The pressure in the pressure treatment is preferably from 0.1 kPa to 100 kPa, more preferably from 0.1 kPa to 20 kPa, even more preferably from 1 kPa to 10 kPa.
Heating may be performed simultaneously with the pressure treatment. The heating temperature at that time is preferably from 50 ° C to 100 ° C.

The method (A2) is specifically a method including the following steps (A2-1) to (A2-4).
Step (A2-1): Forming the insulating resin layer 10 on one surface of the carrier film 30.
Step (A2-2): Forming a metal thin film layer 22 on the surface of the insulating resin layer 10 opposite to the carrier film 30 to form a laminate (p1).
Step (A2-3): Forming a laminate (p2) by forming the anisotropic conductive adhesive layer 24 on the release film 40.
Step (A2-4): Laminate (p1) and laminate (p2) are bonded such that metal thin film layer 22 of laminate (p1) and anisotropic conductive adhesive layer 24 of laminate (p2) are in contact with each other. Paste to.

Step (A2-1) and step (A2-2) are the same as step (A1-1) and step (A1-2), respectively.
In the step (A2-3), the conductive adhesive containing the thermosetting adhesive 24a and the conductive particles 24b is provided not on the metal thin film layer 22 but on the surface of the release film 40 on which the release agent layer 44 is provided. It is the same as the above-mentioned step (A1-3) except that the coating is applied to form the anisotropic conductive adhesive layer 24.
In the bonding of the laminate (p1) and the laminate (p2) in the step (A2-4), even if a pressure treatment for increasing the adhesion between the laminate (p1) and the laminate (p2) is performed. Good. The pressurizing condition is the same as the pressurizing treatment in step (A1-4). In step (A2-4), heating may be performed in the same manner as in step (A1-4).

The method (A3) is specifically a method including the following steps (A3-1) to (A3-4).
Step (A3-1): Forming a laminate (p3) by forming the insulating resin layer 10 on one surface of the carrier film 30.
Step (A3-2): Forming the anisotropic conductive adhesive layer 24 on the release film 40.
Step (A3-3): Forming the metal thin film layer 22 on the surface of the anisotropic conductive adhesive layer 24 opposite to the release film 40 to form a laminate (p4).
Step (A3-4): Laminating the laminate (p3) and the laminate (p4) such that the insulating resin layer 10 of the laminate (p3) and the metal thin film layer 22 of the laminate (p4) are in contact with each other. .

Step (A3-1) is the same as step (A1-1) described above.
In the step (A3-2), the conductive adhesive containing the thermosetting adhesive 24a and the conductive particles 24b is provided not on the metal thin film layer 22 but on the surface of the release film 40 on which the release agent layer 44 is provided. It is the same as the above-mentioned step (A1-3) except that the coating is applied to form the anisotropic conductive adhesive layer 24.
The step (A3-3) is the same as the step (A1) except that the metal thin film layer 22 is formed not on the insulating resin layer 10 but on the surface of the anisotropic conductive adhesive layer 24 opposite to the release film 40. Same as -2).
In the bonding of the laminate (p3) and the laminate (p4) in the step (A3-4), even if a pressure treatment for increasing the adhesion between the laminate (p3) and the laminate (p4) is performed. Good. The pressurizing condition is the same as the pressurizing treatment in step (A1-4). In step (A3-4), heating may be performed in the same manner as in step (A1-4).

  In the method (B1), the method (B2) and the method (B3), the anisotropic conductive adhesive layer 24 is formed using a conductive adhesive paint containing a thermosetting adhesive 24a, conductive particles 24b, and a solvent. Instead of forming the isotropic conductive adhesive layer 26 using a conductive adhesive paint containing a thermosetting adhesive 26a, conductive particles 26b, and a solvent, the method (A1) and the method (A2) ) And method (A3).

(Effect)
As described above, in the electromagnetic wave shielding film 1 of the present embodiment, the insulating resin layer 10 contains one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds. . Although the reason is not clear, the insulating resin layer 10 containing the nitrogen-containing compound has high adhesiveness to the metal thin film layer 22, and the insulating resin layer 10 can be prevented from peeling from the metal thin film layer 22.

(Other embodiments)
The electromagnetic wave shielding film of this aspect is not limited to the above embodiment.
For example, when the adhesive force on the surface of the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26 is small, the release film 40 may be omitted.
When the insulating resin layer 10 has sufficient flexibility and strength, the carrier film 30 may be omitted.
The release film 40 may not have the release agent layer 44 when only the release film main body 42 has sufficient release properties.
The conductive layer may not have the conductive adhesive layer, that is, the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26. When the conductive layer does not have a conductive adhesive layer, an anisotropic conductive adhesive or an isotropic conductive adhesive is applied to an adherend such as the electromagnetic wave shielding film 1 or a printed wiring board to which the electromagnetic wave shielding film is attached. Then, the electromagnetic wave shielding film 1 and the adherend may be bonded.

《Second aspect》
The electromagnetic wave shielding film according to the second aspect of the present invention has an insulating resin layer and a conductive layer, similarly to the electromagnetic wave shielding film of the first aspect.
The electromagnetic wave shielding films of the third embodiment and the fourth embodiment, which are the embodiments of the present aspect, all have the insulating resin layer 10 and the insulating resin, like the electromagnetic wave shielding films 1 of the first embodiment and the second embodiment. A conductive layer 20 adjacent to the layer 10, a carrier film 30 adjacent to the insulating resin layer 10 on the opposite side to the conductive layer 20, a release film 40 adjacent to the conductive layer 20 on the opposite side to the insulating resin layer 10, Having.
In the electromagnetic wave shielding film 1 of the third embodiment, the conductive layer 20 has a metal thin film layer 22 adjacent to the insulating resin layer 10 and an anisotropic conductive adhesive layer 24 adjacent to the release film 40.
In the electromagnetic wave shielding film 1 of the fourth embodiment, the conductive layer 20 has a metal thin film layer 22 adjacent to the insulating resin layer 10 and an isotropic conductive adhesive layer 26 adjacent to the release film 40.
In the electromagnetic wave shielding film of the second embodiment, the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26 is one or two selected from the group consisting of a triazine compound, a triazole compound and an imidazole compound. Contains more than one nitrogen-containing compound. In the insulating resin layer 10 in this embodiment, one or more nitrogen-containing compounds selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound are optional components. Except for these, the electromagnetic wave shielding film of the second embodiment is the same as the electromagnetic wave shielding film of the first embodiment.

The method for manufacturing an electromagnetic wave shielding film according to the second aspect is to form an insulating resin layer from an insulating material containing an insulating resin, to form a metal thin film layer on one surface of the insulating resin layer, and Forming a conductive adhesive layer from a conductive adhesive on a surface of the metal thin film layer opposite to the insulating resin layer. The conductive adhesive contains an adhesive, conductive particles, and one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds.
A specific example of the method for producing an electromagnetic wave shielding film of the second embodiment is that the conductive adhesive coating comprises one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds. Except for further inclusion, it is the same as the specific example of the method for producing an electromagnetic wave shielding film of the first embodiment. However, in the coating material for forming an insulating resin layer in the second embodiment, the nitrogen-containing compound is an optional component.

(Effect)
In the electromagnetic wave shielding film 1 of the present embodiment, the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26 is one or two selected from the group consisting of a triazine-based compound, a triazole-based compound, and an imidazole-based compound. It contains the above nitrogen-containing compound. Although the reason is not clear, even if the anisotropic conductive adhesive layer 24 or the isotropic conductive adhesive layer 26 contains a nitrogen-containing compound, the adhesion between the insulating resin layer 10 and the metal thin film layer 22 increases. In addition, separation of the insulating resin layer 10 from the metal thin film layer 22 can be prevented.

<Printed wiring board with electromagnetic wave shielding film>
One embodiment of the printed wiring board with the electromagnetic wave shielding film of the present invention will be described.
Printed wiring board with an electromagnetic wave shielding film of the present embodiment, a printed wiring board provided with a printed circuit on at least one surface of the substrate, an insulating film adjacent to the surface of the printed wiring board on which the printed circuit is provided, The electromagnetic wave shielding film according to the above aspect, wherein the conductive layer is provided so as to be adjacent to the insulating film.

FIG. 4 is a cross-sectional view showing one embodiment of the printed wiring board with the electromagnetic wave shielding film of the present embodiment.
The 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 surface 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 adhered to the surface of the insulating film 60 and is cured. 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 printed wiring board 2 with the electromagnetic wave shielding film, the release film is peeled off from the anisotropic conductive adhesive layer 24.

  When the carrier film 30 becomes unnecessary in the printed wiring board 2 with the electromagnetic wave shielding film, the carrier 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.) except for the portion having the through-hole, the metal thin film layer 22 of the electromagnetic wave shielding film 1 forms the insulating film 60 and the anisotropic conductive adhesive layer 24. They are arranged facing each other with a distance therebetween.
The separation distance between the printed circuit 54 and the metal thin film layer 22 except for the portion having the through hole 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, more preferably 60 μm or more and 200 μm or less. If the separation distance is smaller than 30 μm, the impedance of the signal circuit becomes low. Therefore, in order to have a characteristic impedance of 100Ω or the like, the line width of the signal circuit must be reduced. As a result, the reflected resonance noise due to the impedance mismatch becomes easy to get on the electric signal. When the separation distance is larger than 200 μm, the 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 obtained by processing a copper foil of a copper-clad laminate into a desired pattern by a known etching method to form a printed circuit 54.
The copper-clad laminate is obtained by attaching a copper foil to one or both sides of a base film 52 via an adhesive layer (not shown); a resin solution or the like for forming the base film 52 is cast on the surface of the copper foil. And the like.
Examples of the material of the adhesive layer include epoxy resin, polyester, polyimide, polyamide imide, 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]
As the base film 52, a film having heat resistance is preferable, a polyimide film and a liquid crystal polymer film are more preferable, and a polyimide film is further preferable.
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 50 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 include a rolled copper foil and an electrolytic copper foil, and a rolled copper foil is preferable from the viewpoint of flexibility. The printed circuit 54 is used, for example, as a signal circuit, a ground circuit, a ground layer, and the like.
The thickness of the copper foil is preferably 1 μm or more and 50 μm or less, more preferably 18 μm or more and 35 μm or less.
The ends (terminals) in the length direction of the printed circuit 54 are exposed without being covered with the insulating film 60 or the electromagnetic wave shielding film 1 for solder connection, connector connection, component mounting, and the like.

(Insulating film)
The insulating film 60 (cover lay film) 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 the insulating film body, a film having heat resistance is preferable, a polyimide film and a liquid crystal polymer film are more preferable, and a polyimide film is further preferable.
The thickness of the insulating film body is preferably 1 μm or more and 100 μm or less, and more preferably 3 μm or more and 25 μm or less from the viewpoint of flexibility.
Examples of the material of the adhesive layer include epoxy resin, polyester, polyimide, polyamide imide, polyamide, phenol resin, urethane resin, acrylic resin, melamine resin, polystyrene, polyolefin, and the like. The epoxy resin may contain a rubber component (such as a carboxy-modified nitrile rubber) for imparting flexibility.
The thickness of the adhesive layer is preferably from 1 μm to 100 μm, more preferably from 1.5 μm to 60 μm.

  The shape of the opening of the through hole formed in the insulating film 60 is not particularly limited. Examples of the shape of the opening of the through hole include a circle, an ellipse, and a square.

<Production method of printed wiring board with electromagnetic wave shielding film>
One embodiment of the method for manufacturing a printed wiring board with an electromagnetic shielding film of the present invention will be described. The method for manufacturing a printed wiring board with an electromagnetic wave shielding film of the present embodiment is a method of crimping a printed wiring board provided with a printed circuit on at least one surface of a substrate and the electromagnetic wave shielding film of the above embodiment via an insulating film. When crimping, the insulating film is brought into close contact with the surface of the printed wiring board on which the printed circuit is provided, and is brought into close contact with the conductive adhesive layer of the electromagnetic wave shielding film.

The printed wiring board 2 with the electromagnetic wave shielding film of the embodiment can be manufactured by, for example, a method including the following steps (a) to (d) (see FIG. 5).
Step (a): An insulating film 60 having a through-hole 62 formed at a position corresponding to the printed circuit 54 is provided on the surface of the flexible printed wiring board 50 on the side where the printed circuit 54 is provided. To get 3.
Step (b): After the step (a), the printed wiring board 3 with the insulating film and the electromagnetic wave shielding film 1 from which the release film 40 has been peeled off are coated with the anisotropic conductive adhesive layer 24 on the surface of the insulating film 60. Lay them in contact and crimp them together.
Step (c): After the step (b), when the carrier film 30 becomes unnecessary, the carrier film 30 is peeled off.
Step (d): If necessary, fully curing the anisotropic conductive adhesive layer 24 between the step (a) and the step (b) or after the step (c).
Hereinafter, each step will be described in detail with reference to FIG.

(Step (a))
The step (a) is to laminate the insulating film 60 on the flexible printed wiring board 50 to obtain the printed wiring board 3 with the insulating film.
Specifically, first, an insulating film 60 having a through hole 62 formed at a position corresponding to the printed circuit 54 is overlaid on the flexible printed wiring board 50. Next, an adhesive layer (not shown) of the insulating film 60 is adhered to the surface of the flexible printed wiring board 50, and the adhesive layer is cured to obtain the printed wiring board 3 with the insulating film. 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 step (d).
The bonding and curing of the adhesive layer are performed by, for example, hot pressing using a press (not shown).

(Step (b))
The step (b) is to press-bond the electromagnetic wave shielding film 1 to the printed wiring board 3 with the insulating film.
Specifically, the electromagnetic wave shielding film 1 from which the release film 40 has been peeled off is overlaid on the printed wiring board 3 with an insulating film, and pressed by hot pressing or the like. As a result, the anisotropic conductive adhesive layer 24 is bonded to the surface of the insulating film 60, and the anisotropic conductive adhesive layer 24 is pushed into the through-hole 62, filling the through-hole 62 and electrically connecting the printed circuit 54 to the printed circuit 54. Connection. Thereby, the printed wiring board 2 with the electromagnetic wave shielding film is obtained.

The bonding and curing of the anisotropic conductive adhesive layer 24 are performed by, for example, hot pressing using a press (not shown) or the like.
The time of the hot pressing is preferably from 20 seconds to 60 minutes, more preferably from 30 seconds to 30 minutes. If the hot pressing time is equal to or longer than the lower limit of the above range, the anisotropic conductive adhesive layer 24 can be easily bonded to the surface of the insulating film 60. If the time of the hot pressing is equal to or less than the upper limit of the above range, the manufacturing time of the printed wiring board 2 with the electromagnetic wave shielding film can be shortened.

  The temperature of the hot press (the temperature of the hot platen of the press) is preferably 140 ° C or more and 190 ° C or less, more preferably 150 ° C or more and 175 ° C or less. When the temperature of the hot pressing is equal to or higher than the lower limit of the above range, the anisotropic conductive adhesive layer 24 can be easily bonded to the surface of the insulating film 60. Further, the time for hot pressing can be reduced. If the temperature of the hot press is equal to or lower than the upper limit of the above range, deterioration of the electromagnetic wave shielding film 1, the flexible printed wiring board 50, and the like can be easily suppressed.

  The pressure of the hot press is preferably 0.5 MPa or more and 20 MPa or less, more preferably 1 MPa or more and 16 MPa or less. If the pressure of the hot press is equal to or higher than the lower limit of the above range, the anisotropic conductive adhesive layer 24 is bonded to the surface of the insulating film 60. Further, the time for hot pressing can be reduced. When the pressure of the hot press is equal to or less than the upper limit of the above range, damage to the electromagnetic wave shielding film 1, the flexible printed wiring board 50, and the like can be suppressed.

(Step (c))
Step (c) is to peel off the carrier film 30.
Specifically, when the carrier film becomes unnecessary, the carrier film 30 is peeled off from the insulating resin layer 10.

(Step (d))
Step (d) is to fully cure the anisotropic conductive adhesive layer 24.
When the time of the hot pressing in the step (b) is a short time of not less than 20 seconds and not more than 10 minutes, the anisotropic conductive adhesive layer is provided between the step (b) and the step (c) or after the step (c). It is preferable to perform 24 full curings.
The main curing of the anisotropic conductive adhesive layer 24 is performed using, for example, a heating device such as an oven.
The heating time is 15 minutes or more and 120 minutes or less, and more preferably 30 minutes or more and 60 minutes or less.
When the heating time is equal to or longer than the lower limit of the above range, the anisotropic conductive adhesive layer 24 can be sufficiently cured. If the heating time is equal to or less than the upper limit of the above range, the manufacturing time of the printed wiring board 2 with the electromagnetic wave shielding film can be reduced.
The heating temperature (atmosphere temperature in the oven) is preferably from 120 ° C to 180 ° C, more preferably from 120 ° C to 150 ° C. When the heating temperature is equal to or higher than the lower limit of the above range, the heating time can be reduced. When the heating temperature is equal to or lower than the upper limit of the above range, deterioration of the electromagnetic wave shielding film 1, the flexible printed wiring board 50, and the like can be suppressed.

(Effect)
Since the printed wiring board 2 with the electromagnetic wave shielding film of this embodiment uses the above-mentioned electromagnetic wave shielding film 1, the adhesiveness between the insulating resin layer 10 and the metal thin film layer 22 is high.

(Other embodiments)
The printed wiring board with the electromagnetic wave shielding film of this aspect is not limited to the above embodiment.
For example, the flexible printed wiring board 50 may have a ground layer on the back surface side. Further, the flexible printed wiring board 50 may have a printed circuit 54 on both sides, and the insulating film 60 and the electromagnetic wave shielding film 1 attached to both sides.
Instead of the flexible printed wiring board 50, a rigid printed board having no flexibility may be used.
Instead of the electromagnetic wave shielding film 1 of the first embodiment, the electromagnetic wave shielding film 1 of the second embodiment, the electromagnetic wave shielding film 1 of the third embodiment, or the electromagnetic wave shielding film 1 of the fourth embodiment may be used.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following embodiments.
The nitrogen-containing compounds used in the following examples are the following compounds.
-Triazine compound (1): VD-5, manufactured by Shikoku Chemicals Co., Ltd., a compound represented by the following formula (1-1). R ¹⁰ in the following formula (1-1) is an alkylene group. Compound that is solid at normal temperature.
-Triazine compound (2): VD-3, manufactured by Shikoku Chemicals, a compound represented by the following formula (1-2). R ¹¹ in the following formula (1-2) is an alkylene group. Compound that is solid at normal temperature.
-Triazole compound (3): BT-LX, manufactured by Johoku Chemical Co., Ltd., a compound represented by the following formula (2-1). Compound that is liquid at room temperature.
-Triazole compound (4): TT-LX, manufactured by Johoku Chemical Co., Ltd., a compound represented by the following formula (2-2). Compound that is liquid at room temperature.
-Triazole compound (5): CBT-1, manufactured by Johoku Chemical Co., Ltd., a compound represented by the following formula (2-3). Compound that is solid at normal temperature.
-Triazole compound (6): BT-120, manufactured by Johoku Chemical Co., Ltd., a compound represented by the following formula (2-4). Compound that is solid at normal temperature.
-Triazole compound (7): manufactured by Johoku Chemical Co., Ltd., 5M-BTA, a compound represented by the following formula (2-5). Compound that is solid at normal temperature.
-Imidazole compound (8): 2MUSIZ manufactured by Shikoku Chemicals, a compound represented by the following formula (3-1). R ¹² in the following formula (3-1) is an alkylene group. Compound that is liquid at room temperature.

(Example 1)
100 parts by mass of an epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828), 20 parts by mass of triphenyl phosphate as a flame retardant (manufactured by Daihachi Chemical Industry Co., Ltd., TPP), 2.0 parts by mass of black carbon black, and a curing agent 20 parts by mass (Showamin X, manufactured by Showa Denko KK) and methyl ethyl ketone as a diluting solvent were mixed to prepare a first insulating resin layer forming paint. The addition amount of methyl ethyl ketone was adjusted so that the solid content concentration of the coating material for forming an insulating resin layer was 40% by mass.
100 parts by mass of an epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828), 20 parts by mass of triphenyl phosphate as a flame retardant (manufactured by Daihachi Chemical Industry Co., Ltd., TPP), 2.0 parts by mass of black carbon black, and a curing agent (Showa Denko Co., Ltd., Showamine X) 20 parts by mass, triazine-based compound (1) 5 parts by mass as a nitrogen-containing compound, and methyl ethyl ketone as a diluting solvent were mixed to form a second insulating resin layer. Paint was prepared. The addition amount of methyl ethyl ketone was adjusted so that the solid content concentration of the coating material for forming an insulating resin layer was 40% by mass.
Latent curable epoxy resin obtained by mixing 100 parts by mass of an epoxy resin (EXA-4816, manufactured by DIC Corporation) and 15 parts by mass of a curing agent (PN-23, manufactured by Ajinomoto Fine Techno Co., Ltd.) as a thermosetting adhesive And 40 parts by mass of conductive particles (copper particles, average particle size: 8 μm) were dissolved or dispersed in methyl ethyl ketone to prepare a coating for forming an anisotropic conductive adhesive layer. The addition amount of methyl ethyl ketone was adjusted so that the solid content concentration of the coating material for forming an anisotropic conductive adhesive layer was 40% by mass.

As a carrier film, a PET film (T157, manufactured by Lintec Corporation, thickness: 50 μm) having one surface treated with a non-silicone type release agent was prepared. The coating for forming the first insulating resin layer is applied to the release-treated surface of the carrier film made of the PET film using a bar coater, dried at 100 ° C. for 2 minutes, and dried to a thickness of 5 μm. Was formed. Next, the second insulating resin layer forming paint is applied to the surface of the first insulating resin layer using a bar coater, and dried at 100 ° C. for 2 minutes to form a second insulating resin having a thickness of 5 μm. A resin layer was formed. In this example, the insulating resin layer is composed of two layers, the first insulating resin layer and the second insulating resin layer.
Copper was deposited by vacuum deposition on the surface of the insulating resin layer opposite to the carrier film to form a metal thin film layer. Next, on the surface of the metal thin film layer opposite to the insulating resin layer, the anisotropic conductive adhesive layer forming paint is applied using a bar coater, and dried at 80 ° C. for 1 minute to obtain a thickness. An 8 μm anisotropic conductive adhesive layer was formed. Thus, an electromagnetic wave shielding film was obtained.

(Examples 2 to 40)
An electromagnetic wave shielding film was obtained in the same manner as in Example 1, except that the type and content of the nitrogen-containing compound contained in the second insulating resin layer forming paint were changed to the compounds shown in Tables 1 to 3.

(Example 41)
100 parts by mass of an epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828), 20 parts by mass of triphenyl phosphate as a flame retardant (manufactured by Daihachi Chemical Industry Co., Ltd., TPP), 2.0 parts by mass of black carbon black, and a curing agent 20 parts by mass (Showamin X, manufactured by Showa Denko KK) and methyl ethyl ketone as a diluting solvent were mixed to prepare a first insulating resin layer forming paint and a second insulating resin layer forming paint. The addition amount of methyl ethyl ketone was adjusted so that the solid content concentration of the coating material for forming an insulating resin layer was 40% by mass.
As a thermosetting adhesive, 100 parts by mass of an epoxy resin (EXA-4816, manufactured by DIC Corporation), 5 parts by mass of a triazine-based compound (1), which is a nitrogen-containing compound, and a curing agent (PN, manufactured by Ajinomoto Fine Techno Co., Ltd.) -23) a latent curable epoxy resin mixed with 15 parts by mass, and 40 parts by mass of conductive particles (copper particles, average particle size: 8 μm) dissolved or dispersed in methyl ethyl ketone, and an anisotropic conductive adhesive A coating material for forming a layer was prepared. The addition amount of methyl ethyl ketone was adjusted so that the solid content concentration of the coating material for forming an anisotropic conductive adhesive layer was 40% by mass.
Thereafter, except that the first insulating resin layer forming paint, the second insulating resin layer forming paint, and the anisotropic conductive adhesive layer forming paint were used, an electromagnetic wave shielding film was formed in the same manner as in Example 1. Obtained.

(Examples 42 to 45)
An electromagnetic wave shielding film was obtained in the same manner as in Example 41, except that the content of the nitrogen-containing compound contained in the paint for forming an anisotropic conductive adhesive layer was changed to the amount shown in Table 4.

(Comparative Example 1)
An electromagnetic wave shielding film was obtained in the same manner as in Example 1 except that the nitrogen-containing compound was not contained in the coating for forming the second insulating resin layer.

<Evaluation>
With respect to the electromagnetic wave shielding film of each example, the adhesiveness was evaluated by the following method. The evaluation results are shown in Tables 1 to 3.

(Adhesiveness)
A polyimide film having a thickness of 25 μm was attached to the anisotropic conductive adhesive surface of the electromagnetic wave shielding film, and thermocompression bonded at a temperature of 170 ° C., a pressure of 3 MPa, and a pressing time of 3 minutes.
Next, the carrier film is peeled off from the insulating resin layer, and a 25 μm-thick polyimide film is attached to the insulating resin layer via a bonding sheet (AEDS10KA, manufactured by Arisawa Seisakusho Co., Ltd.), and the temperature is 170 ° C., the pressure is 3 MPa, and the pressure is Thermocompression bonding was performed for 3 minutes. Thus, a laminate in which the electromagnetic wave shielding film was sandwiched between two polyimide films was obtained.
The laminate was heated at 150 ° C. for 1 hour to fully cure the anisotropic conductive adhesive layer, thereby obtaining an electromagnetic wave shielding film with a polyimide film.
Using a tensile tester (Autograph manufactured by Shimadzu Corporation), the polyimide film adhered to the anisotropic conductive adhesive layer of the electromagnetic wave shielding film with the polyimide film was peeled 180 °, and the peel force required for the peeling was measured. It was measured. The larger the peel force, the higher the adhesiveness.

In each of the examples in which the insulating resin layer contained a nitrogen-containing compound, the adhesion between the insulating resin layer and the metal thin film layer was high.
In the comparative example in which neither the insulating resin layer nor the anisotropic conductive adhesive layer contained a nitrogen-containing compound, the adhesion between the insulating resin layer and the metal thin film layer was low.

Reference Signs List 1 electromagnetic wave shielding film 2 printed wiring board with electromagnetic shielding film 3 printed wiring board with insulating film 10 insulating resin layer 20 conductive layer 22 metal thin film layer 24 anisotropic conductive adhesive layer 24a thermosetting adhesive 24b conductive particles 26, etc. Conductive adhesive layer 26a Thermosetting adhesive 26b Conductive particles 30 Carrier film 32 Carrier film body 34 Release agent layer 40 Release film 42 Release film body 44 Release agent layer 50 Flexible printed wiring board 52 Base film 54 Printed circuit 60 Insulating film 62 Through hole

Claims (21)

Having an insulating resin layer and a conductive layer adjacent to the insulating resin layer,
The insulating resin layer contains an insulating resin and one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds,
An electromagnetic shielding film, wherein the conductive layer has a metal thin film layer in contact with the insulating resin layer.   2. The electromagnetic wave shielding film according to claim 1, wherein the content of the nitrogen-containing compound in the insulating resin layer is 0.1 parts by mass or more and 50 parts by mass or less based on 100 parts by mass of the insulating resin. Having an insulating resin layer and a conductive layer adjacent to the insulating resin layer,
The conductive layer has a metal thin film layer in contact with the insulating resin layer, and a conductive adhesive layer formed on a surface of the metal thin film layer opposite to the insulating resin layer,
The electromagnetic wave, wherein the conductive adhesive layer contains an adhesive, conductive particles, and one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds. Shield film.   4. The electromagnetic wave shielding film according to claim 3, wherein the content of the nitrogen-containing compound in the conductive adhesive layer is 0.1 to 50 parts by mass based on 100 parts by mass of the adhesive. 5. An insulating resin layer, and a conductive layer adjacent to the insulating resin layer, wherein the conductive layer is a metal thin film layer in contact with the insulating resin layer, and a surface of the metal thin film layer opposite to the insulating resin layer. Having a conductive adhesive layer formed on the
The insulating resin layer contains an insulating resin and one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds,
The electromagnetic wave, wherein the conductive adhesive layer contains an adhesive, conductive particles, and one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds. Shield film. The content of the nitrogen-containing compound in the insulating resin layer is 0.1 to 50 parts by mass with respect to 100 parts by mass of the insulating resin,
The electromagnetic wave shielding film according to claim 5, wherein the content of the nitrogen-containing compound in the conductive adhesive layer is 0.1 to 50 parts by mass based on 100 parts by mass of the adhesive.   The electromagnetic wave shielding film according to any one of claims 1 to 6, wherein the nitrogen-containing compound is a liquid or a solid at room temperature. The electromagnetic wave shielding film according to any one of claims 1 to 7, wherein the triazine-based compound is a compound represented by the following formula (1).

[R ¹ , R ² and R ³ in the formula (1) are each independently an arbitrary substituent. ] The electromagnetic wave shielding film according to claim 8, wherein R ¹ and R ² in the formula (1) are each independently an amino group or a thiol group. The electromagnetic wave shielding film according to claim 8, wherein R ³ in the formula (1) is a substituent having a trialkoxysilyl group or a substituent having a hydroxy group. The electromagnetic wave shielding film according to any one of claims 1 to 10, wherein the triazole-based compound is a compound represented by the following formula (2).

[R ⁴ and R ⁵ in the formula (2) are each independently an arbitrary substituent. ] Formula R ⁴ is in (2), a methyl group or a carboxy group, an electromagnetic wave shielding film according to claim 11. The formula R ⁵ in (2), a hydrogen atom bonded to the nitrogen atom is a which may be an aminoalkyl group-substituted, electromagnetic wave shielding film according to claim 11 or 12. The electromagnetic wave shielding film according to any one of claims 1 to 13, wherein the imidazole-based compound is a compound represented by the following formula (3).

[R ⁶ and R ⁷ in the formula (3) are each independently an arbitrary substituent. ] R ⁶ in the formula (3) is an alkyl group, an electromagnetic wave shielding film according to claim 14. The electromagnetic wave shielding film according to claim 14, wherein R ⁷ in the formula (3) is a substituent having a trialkoxysilyl group.   The electromagnetic shielding film according to any one of claims 1 to 16, wherein the metal thin film layer contains copper or silver. A printed wiring board provided with a printed circuit on at least one side of the substrate,
An insulating film adjacent to a surface of the printed circuit board on which the printed circuit is provided;
The electromagnetic wave shielding film according to any one of claims 1 to 17, wherein the conductive layer is provided so as to be adjacent to the insulating film.
A printed wiring board with an electromagnetic wave shielding film having: Forming an insulating resin layer from an insulating resin and an insulating material containing one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds;
And forming a metal thin film layer on one surface of the insulating resin layer. Forming an insulating resin layer from an insulating material containing an insulating resin,
Forming a metal thin film layer on one surface of the insulating resin layer,
And one or two selected from the group consisting of an adhesive, conductive particles, a triazine-based compound, a triazole-based compound, and an imidazole-based compound, on a surface of the metal thin film layer opposite to the insulating resin layer. Forming a conductive adhesive layer from a conductive adhesive containing the above nitrogen-containing compound. Forming an insulating resin layer from an insulating resin and an insulating material containing one or more nitrogen-containing compounds selected from the group consisting of triazine-based compounds, triazole-based compounds, and imidazole-based compounds;
Forming a metal thin film layer on one surface of the insulating resin layer,
And one or two selected from the group consisting of an adhesive, conductive particles, a triazine-based compound, a triazole-based compound, and an imidazole-based compound, on a surface of the metal thin film layer opposite to the insulating resin layer. Forming a conductive adhesive layer from a conductive adhesive containing the above nitrogen-containing compound.

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