JP2021044342A - Method of manufacturing electromagnetic wave shield film and method of manufacturing printed wiring board with electromagnetic wave shield film - Google Patents

Abstract

To provide a simpler and lower-cost method of manufacturing an electromagnetic wave shield film, which includes a reduced number of manufacturing steps and with which it is possible to manufacture an electromagnetic wave shield film, which excels in adhesive property between an insulation resin layer and a metal thin film layer as well as adhesive property between the metal thin film layer and an adhesive layer, and also manufacture an electromagnetic wave shield film, which excels in shield property and transmission characteristic regarding an FPC.SOLUTION: A method of manufacturing an electromagnetic wave shield film, which includes an insulation resin layer, an electrolytic plated copper thin film layer adjacent to the insulation resin layer, and an adhesive layer adjacent to a side opposite to the insulation resin layer of the electrolytic plated copper thin film layer, comprises: a step (b) for providing the adhesive layer for a surface of the electrolytic plated copper thin film layer provided for a surface of a carrier copper foil by an electrolytic plating method; and a step (c) for providing the insulation resin layer for a surface on a side opposite to the adhesive layer of the electrolytic plated copper thin film layer by peeling the carrier copper foil from the electrolytic plated copper thin film layer.SELECTED DRAWING: None

Description

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

From the insulating resin layer, the metal thin film layer adjacent to the insulating resin layer, and the conductive adhesive layer in order to shield the electromagnetic noise generated from the flexible printed wiring board (hereinafter, also referred to as FPC) and the electromagnetic noise from the outside. An electromagnetic wave shielding film composed of a constituent conductive layer may be provided on the surface of a flexible printed wiring board (see, for example, Patent Document 1).
In Patent Document 1, the insulating resin layer in the electromagnetic wave shielding film is formed by applying a coating liquid containing a thermosetting resin, a curing agent, and a solvent to one side of the first release film and drying it. .. Further, the metal thin film layer is formed by depositing metal on the surface of the insulating resin layer.
However, since the insulating resin layer made of a cured product of a thermosetting resin has too high hardness, the metal thin film layer formed by depositing metal on the surface of the insulating resin layer has adhesiveness to the insulating resin layer. Insufficient. Therefore, when the first release film is peeled from the insulating resin layer, peeling may occur at the interface between the insulating resin layer and the metal thin film layer.

Therefore, a method for producing an electromagnetic wave shielding film has been proposed, which has excellent adhesiveness between an insulating resin layer and a metal thin film layer, and also has excellent adhesiveness between an adhesive layer composed of a conductive adhesive layer and a metal thin film layer. (See, for example, Patent Document 2).
In Patent Document 2, an adhesive layer is provided on the surface of the metal thin film layer provided on the surface of the carrier film, and then the carrier film is peeled off from the metal thin film layer on the side opposite to the adhesive layer of the metal thin film layer. A method for manufacturing an electromagnetic wave shielding film in which an insulating resin layer is provided on the surface is described.

Japanese Unexamined Patent Publication No. 2016-86120 JP-A-2018-56424

By the way, in order to improve the shielding property against FPC and the transmission characteristics, it is preferable that the thickness of the metal thin film layer is thick to some extent. Therefore, for example, it is desirable to prepare the metal thin film layer by a plating method capable of accurately and stably producing a metal thin film layer having a thickness of 1 μm or more.
However, in the method for producing an electromagnetic wave shield film described in Patent Document 2, the metal thin film layer is provided on a carrier film of polyethylene terephthalate (PET), and in the method for producing an electromagnetic wave shield film described in Patent Document 2, the metal thin film layer is provided. When an attempt is made to form a metal thin film layer by using a plating method, it is necessary to once provide a metal layer on a PET carrier film by a sputtering method or the like, and to form a metal plating layer on the metal layer.

Therefore, the present invention is a method for producing an electromagnetic wave shielding film that is simpler and less costly by reducing the number of manufacturing steps, and the adhesiveness between the insulating resin layer and the metal thin film layer is also the adhesive layer and the metal thin film layer. It is an object of the present invention to provide a method for producing an electromagnetic wave shielding film, which can produce an electromagnetic wave shielding film having excellent adhesiveness, and further can produce an electromagnetic wave shielding film having excellent shielding property against FPC and transmission characteristics. And.

The present invention includes the following aspects.
[1] Insulating resin layer and
The electroplated copper thin film layer adjacent to the insulating resin layer and
This is a method for producing an electromagnetic wave shielding film having an adhesive layer adjacent to the insulating resin layer of the electroplated copper thin film layer on the opposite side.
A method for producing an electromagnetic wave shielding film, which comprises the following steps (b) and (c).
Step (b): A step of providing the adhesive layer on the surface of the electroplated copper thin film layer with respect to the electroplated copper thin film layer provided on the surface of the carrier copper foil by the electroplating method.
Step (c): A step of peeling the carrier copper foil from the electroplated copper thin film layer and providing the insulating resin layer on the surface of the electroplated copper thin film layer opposite to the adhesive layer.
[2] The method for producing an electromagnetic wave shielding film according to the above [1], wherein the thickness of the electroplated copper thin film layer is 1 μm or more and 3 μm or less.
[3] The electromagnetic wave according to the above [1] or [2], wherein the arithmetic mean roughness (Ra) of the surface of the electroplated copper thin film layer on the adhesive layer side is 0.5 μm or more and 2.5 μm or less. Manufacturing method of shield film.
[4] The method for producing an electromagnetic wave shielding film according to any one of [1] to [3] above, wherein the insulating resin layer is a film-shaped insulating resin layer containing an aromatic polyetherketone.
[5] The method for producing an electromagnetic wave shielding film according to any one of [1] to [4] above, wherein the insulating resin layer contains insulating particles in the layer.
[6] When the electromagnetic wave shielding film has a first release film adjacent to the side of the insulating resin layer opposite to the electroplated copper thin film layer.
The first release film has a base material layer and a pressure-sensitive adhesive layer or a mold release agent layer provided on the surface of the base material layer on the insulating resin layer side.
The method for producing an electromagnetic wave shielding film according to any one of [1] to [5], wherein the surface of the base material layer has an uneven shape.
[7] When the electromagnetic wave shielding film has a first release film adjacent to the side of the insulating resin layer opposite to the electroplated copper thin film layer.
The first release film has a base material layer and a pressure-sensitive adhesive layer or a mold release agent layer provided on the surface of the base material layer on the insulating resin layer side.
The method for producing an electromagnetic wave shielding film according to any one of [1] to [6] above, wherein the pressure-sensitive adhesive layer or the release agent layer contains insulating particles in the layer.
[8] When the electromagnetic wave shielding film has a second release film adjacent to the side of the adhesive layer opposite to the electroplated copper thin film layer.
Any of the above [1] to [7], wherein the peeling force at the interface between the electrolytically plated copper thin film layer and the carrier copper foil is smaller than the peeling force at the interface between the adhesive layer and the second release film. A method for manufacturing an electromagnetic wave shielding film described in Crab.
[9] The peeling force at the interface between the electrolytically plated copper thin film layer and the carrier copper foil is 0.1 N / cm or more and 1.5 N / cm or less, and the adhesive layer and the second release film The method for producing an electromagnetic wave shielding film according to the above [8], wherein the peeling force at the interface between the two is 0.2 N / cm or more and 2.5 N / cm or less.
[10] After manufacturing the electromagnetic wave shield film by the method for manufacturing the electromagnetic wave shield film according to any one of [1] to [9] above,
A method for manufacturing a printed wiring board with an electromagnetic wave shielding film, which carries out the following steps (d) and (e).
Step (d): A step of providing an insulating film on the surface of the printed wiring board on the side where the printed circuit is provided to obtain a printed wiring board with the insulating film.
Step (e): When the electromagnetic wave shielding film has a second release film, after peeling the second release film from the electromagnetic wave shielding film, the printed wiring board with the insulating film and the electromagnetic wave shielding film. The adhesive layer is laminated on the surface of the insulating film so that the adhesive layer is in contact with the surface of the insulating film, and by pressing these, the adhesive layer is adhered to the surface of the insulating film to obtain a printed wiring board with an electromagnetic wave shielding film. Process.

According to the present invention, it is a method for manufacturing an electromagnetic wave shielding film that is simpler and less costly by reducing the number of manufacturing steps, and the adhesiveness between the insulating resin layer and the metal thin film layer is also the adhesive layer and the metal thin film layer. It is possible to provide a method for producing an electromagnetic wave shielding film, which can produce an electromagnetic wave shielding film having excellent adhesiveness, and further can produce an electromagnetic wave shielding film having excellent shielding property against FPC and transmission characteristics. ..

FIG. 1 is a cross-sectional view showing an embodiment of an electromagnetic wave shielding film. FIG. 2 is a cross-sectional view showing another embodiment of the electromagnetic wave shielding film. FIG. 3 is a cross-sectional view showing another embodiment of the electromagnetic wave shielding film. FIG. 4 is a cross-sectional view showing another embodiment of the electromagnetic wave shielding film. FIG. 5 is a cross-sectional view showing a step (a), a step (b1), and a step (b2) in the manufacturing process of the electromagnetic wave shielding film of FIG. FIG. 6 is a cross-sectional view showing steps (c1) to (c3) of the manufacturing process of the electromagnetic wave shielding film of FIG. FIG. 7 is a cross-sectional view showing steps (c1) to (c3) of the manufacturing process of the electromagnetic wave shielding film of FIG. FIG. 8 is a cross-sectional view showing an embodiment of a printed wiring board with an electromagnetic wave shielding film. FIG. 9 is a cross-sectional view showing a manufacturing process of the printed wiring board with the electromagnetic wave shielding film of FIG. FIG. 10 is a cross-sectional view showing another embodiment of the electromagnetic wave shielding film. FIG. 11 is a cross-sectional view showing another embodiment of the printed wiring board with an electromagnetic wave shielding film. FIG. 12 is a cross-sectional view showing another embodiment of the printed wiring board with the electromagnetic wave shielding film.

Hereinafter, the method for producing the electromagnetic wave shielding film of the present invention will be described in detail, but the description of the constituent requirements described below is an example as an embodiment of the present invention, and is not specified in these contents. ..
The definitions of the following terms apply throughout the specification and claims.
The "isotropic conductive adhesive layer" means a conductive adhesive layer having conductivity in the thickness direction and the surface direction.
The "anisotropic adhesive layer" means a conductive adhesive layer having conductivity in the thickness direction and not in the plane direction.
The “conductive adhesive layer having no conductivity in the plane direction” means a conductive adhesive layer having a surface resistance of 1 × 10 ⁴ Ω or more.
For the average particle size of the conductive particles, 30 conductive particles were randomly selected from the microscopic image of the conductive particles, and the minimum and maximum diameters of each conductive particle were measured. The median value of is taken as the particle size of one particle, and the measured particle size of the 30 conductive particles is calculated and averaged.
For the thickness of the film (release film, insulating film, etc.), coating film (insulating resin layer, adhesive layer, conductive adhesive layer, etc.), electrolytically plated copper thin film layer, etc., use a microscope to measure the cross section of the object to be measured. It is an average value obtained by observing and measuring the thickness at 5 points.
For the surface resistance, two thin film metal electrodes (length 10 mm, width 5 mm, distance between electrodes 10 mm) formed by depositing gold on quartz glass are used, and an object to be measured is placed on the electrodes to be measured. It is the resistance between the electrodes measured with a measurement current of 1 mA or less by pressing a region of 10 mm × 20 mm of the object to be measured with a load of 0.049 N from above the object.
The peeling force is a peeling force measured by performing a 180-degree peeling test using a tensile tester.
The arithmetic mean roughness Ra is a value obtained by measuring a roughness curve of a test piece using a laser microscope and obtaining from this roughness curve based on JIS B 0601: 2013 (ISO 4287: 1997 Amd.1: 2009). Is.

[Manufacturing method of electromagnetic wave shield film]
The present invention defines a method for producing an electromagnetic wave shielding film.
The electromagnetic wave shield film has an insulating resin layer, an electroplated copper thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the side opposite to the insulating resin layer of the electroplated copper thin film layer.
The method for producing an electromagnetic wave shielding film of the present invention has the following steps (b) and (c).
Step (b): A step of providing an adhesive layer on the surface of the electroplated copper thin film layer with respect to the electroplated copper thin film layer provided on the surface of the carrier copper foil by the electroplating method.
Step (c): A step of peeling the carrier copper foil from the electroplated copper thin film layer and providing an insulating resin layer on the surface of the electroplated copper thin film layer opposite to the adhesive layer.

The method for producing the electromagnetic wave shielding film of the present invention will be described in detail later. First, the electromagnetic wave shielding film which is the target of the method for producing the electromagnetic wave shielding film of the present invention will be described.

(Electromagnetic wave shield film)
FIG. 1 is a cross-sectional view showing a first embodiment of the electromagnetic wave shielding film obtained by the manufacturing method of the present invention, and FIG. 2 shows a second embodiment of the electromagnetic wave shielding film obtained by the manufacturing method of the present invention. It is sectional drawing which shows.
The electromagnetic wave shield film 1 of the first embodiment and the second embodiment has an insulating resin layer 10; an electrolytically plated copper thin film layer 20 adjacent to the insulating resin layer 10; and an insulating resin layer 10 of the electrolytically plated copper thin film layer 20. With the adhesive layer 22 adjacent to the opposite side; with the first release film 30 adjacent to the electrolytically plated copper thin film layer 20 of the insulating resin layer 10; and the electrolytically plated copper thin film layer of the adhesive layer 22. It has a second release film 40 adjacent to the opposite side of the 20.

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

<Insulating resin layer>
In the insulating resin layer 10, the electromagnetic wave shielding film 1 is attached to the surface of the insulating film provided on the surface of the flexible printed wiring board, and after the first release film 30 is peeled off, the electrolytically plated copper thin film layer 20 is formed. It becomes a protective layer.

As the insulating resin layer 10, a coating film formed by applying a composition containing a curable resin and a curing agent and semi-curing or curing; a coating liquid containing a curable resin, a curing agent and a solvent is applied. A coating film formed by drying, semi-curing or curing; a coating film formed by applying a coating liquid containing a thermoplastic resin and a solvent; and drying the coating film; melting the composition containing the thermoplastic resin. Examples thereof include a layer made of a molded film. The insulating resin layer 10 is a resin material (combination of a curable resin and a curing agent, or a thermoplastic resin) and a solvent from the viewpoint that the adhesiveness between the insulating resin layer 10 and the electrolytically plated copper thin film layer 20 is further improved. A coating film formed by applying a coating liquid containing the above, drying, and semi-curing or curing as needed is preferable.

Examples of the curable resin include amide resin, epoxy resin, phenol resin, amino resin, alkyd resin, urethane resin, synthetic rubber, and ultraviolet curable acrylate resin. As the curable resin, an ultraviolet curable acrylate resin is preferable because the adhesiveness between the insulating resin layer and the electroplated copper thin film layer is further improved.
Examples of the curing agent include known curing agents depending on the type of curable resin. When the curable resin is an ultraviolet curable acrylate resin, examples of the curing agent include a photoradical initiator and the like.

The insulating resin layer 10 uses one or both of a colorant and a filler in order to conceal the printed circuit of the printed wiring board with the electromagnetic wave shielding film and to impart design to the printed wiring board with the electromagnetic wave shielding film. It may be included.
The insulating resin layer 10 may contain a flame retardant.
The insulating resin layer 10 may contain other components, if necessary, as long as the effects of the present invention are not impaired.

In order to suppress the reflection of light on the surface of the insulating resin layer, an uneven shape may be formed on the surface of the insulating resin layer. For example, insulating particles may be contained in the insulating resin layer to form an uneven shape on the surface of the insulating resin layer. Alternatively, when the electromagnetic wave shielding film has a first release film adjacent to the side opposite to the electrolytically plated copper thin film layer of the insulating resin layer, the irregularities on the surface of the first release film are transferred. , An uneven shape may be formed on the surface of the insulating resin layer.
Regarding the fact that an electromagnetic wave shield film in which light reflection on the surface of the insulating resin layer is suppressed can be obtained by forming an uneven shape on the surface of the insulating resin layer, the following <Suppression of light on the surface of the insulating resin layer is suppressed. It will be explained in detail in the column of Electromagnetic wave shield film>.

The surface resistance of the insulating resin layer 10 ^{is preferably 1 × 10 6} Ω or more from the viewpoint of electrical insulation. The surface resistance of the insulating resin layer 10 ^{is preferably 1 × 10 19} Ω or less from a practical point of view.
The thickness of the insulating resin layer 10 is preferably 0.1 μm or more and 30 μm or less, more preferably 0.5 μm or more and 20 μm or less, and further preferably 3 μm or more and 15 μm or less. When the thickness of the insulating resin layer 10 is at least the lower limit of the above range, the insulating resin layer 10 can sufficiently exert the function as a protective layer. When the thickness of the insulating resin layer 10 is not more than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned.

<< Film-shaped insulating resin layer >>
In the present invention, the insulating resin layer can be a film-shaped insulating resin layer.
Examples of the film-shaped insulating resin layer include a film-shaped insulating resin layer containing an aromatic polyetherketone.
When the insulating resin layer is a film-shaped insulating resin layer containing an aromatic polyetherketone, the insulating resin layer can be formed with a thin film thickness, and even if the insulating resin layer has a thin film thickness. , The adhesiveness between the insulating resin layer and the metal thin film layer composed of the electrolytically plated copper thin film layer can be well maintained.

FIG. 3 is a cross-sectional view showing a third embodiment of the electromagnetic wave shielding film according to the present invention, and FIG. 4 is a cross-sectional view showing a fourth embodiment of the electromagnetic wave shielding film according to the present invention.
The electromagnetic wave shield film 1 of the third embodiment shown in FIG. 3 is the electromagnetic wave shield film of the first embodiment shown in FIG. 1 in that the insulating resin layer 10 is changed to a film-shaped insulating resin layer 10a. Are different. In FIG. 3, the adhesive layer 10b for the insulating resin layer is arranged between the film-shaped insulating resin layer 10a and the electrolytically plated copper thin film layer 20, but the film-shaped insulating resin layer 10a and the electrolytic. Depending on the state of adhesion with the plated copper thin film layer 20, the adhesive layer 10b for the insulating resin layer may not be provided.
As the adhesive layer 10b for the insulating resin layer, the same adhesive as that described in the column of <Adhesive layer> described later can be used.
In the electromagnetic wave shielding film 1 of the fourth embodiment shown in FIG. 4, the insulating resin layer 10 is changed to a film-shaped insulating resin layer 10a in the electromagnetic wave shielding film of the second embodiment shown in FIG. Are different.

The film-shaped insulating resin layer 10a contains an aromatic polyetherketone. The aromatic polyetherketone is a polymer having a structure in which benzene rings are bonded to each other via an ether bond and a structure in which benzene rings are bonded to each other via a ketone group.
Examples of the aromatic polyetherketone include a polyetheretherketone (PEEK) having a chemical structure represented by the chemical formula (1), a polyetherketone (PEK) having a chemical structure represented by the chemical formula (2), and a chemical formula. Polyetheretherketoneketone (PEKK) having a chemical structure represented by (3), polyetheretherketoneketone (PEEKK) having a chemical structure represented by chemical formula (4), and chemical structure represented by chemical formula (5). Polyetherketone etherketoneketone (PEKEKK) having the above can be mentioned. The aromatic polyetherketone contained in the film-shaped insulating resin layer 10a may be used alone or in combination of two or more.
Further, the aromatic polyetherketone may be a copolymer having two or more chemical structures represented by the chemical formulas (1) to (5).
Both ends of the aromatic polyetherketone are hydrogen atoms.

Among the above aromatic polyetherketones, the polyetheretherketone is preferable in that a film-shaped insulating resin layer 10a can be easily formed.
When the electromagnetic wave shield film 1 is required to have heat resistance, among aromatic polyetherketones, polyetherketone, polyetherketoneketone, and polyetherketoneetherketoneketone are preferable. The glass transition temperature of polyetherketone is 152 ° C, the glass transition temperature of polyetherketoneketone is 154 ° C, and the glass transition temperature of polyetherketone etherketoneketone is 162 ° C. Higher than 143 ° C. Therefore, it is suitable for applications that require heat resistance. The glass transition temperature of the resin is determined by differential thermal calorimetry (DSC).

Each n of the above chemical formulas (1) to (5) is preferably 10 or more, more preferably 20 or more, from the viewpoint of mechanical properties. On the other hand, from the viewpoint that the aromatic polyetherketone can be easily produced, n is preferably 5000 or less, and more preferably 1000 or less. That is, it is preferably 10 or more and 5000 or less, and more preferably 20 or more and 1000 or less.
The aromatic polyetherketone may be a block copolymer, a random copolymer or a modified product with another copolymerizable monomer such as ether sulfone as long as the effect of the present invention is not impaired. ..
In the aromatic polyetherketone, the ratio of the polyetherketone unit represented by any of the above chemical formulas (1) to (5) is 50 mol% or more and 100 mol% or less with respect to 100 mol% of the aromatic polyetherketone. It is preferably 70 mol% or more and 100 mol% or less, more preferably 80 mol% or more and 100 mol% or less, and most preferably 100 mol%. When the ratio of the aromatic polyetherketone unit in the aromatic polyetherketone is at least the above lower limit value, the adhesive force between the film-shaped insulating resin layer 10a and the electroplated copper thin film layer 20 can be further strengthened.

Examples of the method for producing an aromatic polyetherketone, particularly the method for producing a polyetheretherketone, include JP-A-50-27897, JP-A-51-119797, and JP-A-52-38000. It is disclosed in Kaisho 54-90296, Tokusho 55-23574, and Tokusho 56-2091.

The film-shaped insulating resin layer 10a may contain other resins in addition to the aromatic polyetherketone. Examples of other resins include polyimide, polyamideimide, polyamide, polysulfone, polyethersulfone, polyphenylene sulfide, polyphenylene sulfide, polyphenylene sulfide sulfide, polyphenylene sulfide ketone and the like.
The content of the aromatic polyetherketone in the film-shaped insulating resin layer 10a is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, and 80% by mass or more. It is more preferably 100% by mass or less. The film-shaped insulating resin layer 10a may be composed of only aromatic polyetherketone. When the content of the aromatic polyetherketone in the film-shaped insulating resin layer 10a is at least the above lower limit value, the adhesive force of the film-shaped insulating resin layer 10a to the electroplated copper thin film layer 20 can be further strengthened.

The thickness of the film-shaped insulating resin layer 10a is preferably 0.1 μm or more and 30 μm or less, more preferably 2.0 μm or more and 10 μm or less, further preferably 2.0 μm or more and 5.0 μm or less, and 3.0 μm or more and 5.0 μm. The following are particularly preferred. When the thickness of the film-shaped insulating resin layer 10a is equal to or greater than the lower limit of the above range, the film-shaped insulating resin layer 10a can sufficiently exhibit the function as a protective layer. When the thickness of the film-shaped insulating resin layer 10a is equal to or less than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned.

<Electroplated copper thin film layer>
The electroplated copper thin film layer 20 is a layer made of a copper thin film formed by an electrolytic plating method. Since the electroplated copper thin film layer 20 is formed so as to spread in the surface direction, it has conductivity in the surface direction and functions as an electromagnetic wave shield layer or the like.

Since the electroplated copper thin film layer 20 is formed by the electroplating method, a metal thin film layer having a thickness of 1 μm or more can be produced accurately and stably. Therefore, the electromagnetic wave shield film according to the present invention, which uses a layer made of a copper thin film formed by an electrolytic plating method as a metal thin film layer, is excellent in shielding properties against FPC and transmission characteristics.

The surface resistance of the electroplated copper thin film layer 20 is preferably 0.001 Ω or more and 1 Ω or less, and more preferably 0.001 Ω or more and 0.1 Ω or less. When the surface resistance of the electroplated copper thin film layer 20 is at least the lower limit of the above range, the electroplated copper thin film layer 20 can be sufficiently thinned. When the surface resistance of the electroplated copper thin film layer 20 is not more than the upper limit of the above range, it can sufficiently function as an electromagnetic wave shielding layer.

The thickness of the electroplated copper thin film layer 20 is preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more and 5 μm or less, further preferably 1 μm or more and 3 μm or less, and particularly preferably 1 μm or more and 2 μm or less. When the thickness of the electroplated copper thin film layer 20 is 0.01 μm or more, the conductivity in the plane direction is further improved. When the thickness of the electroplated copper thin film layer 20 is 0.05 μm or more, the shielding effect of electromagnetic noise is further improved. When the thickness of the electroplated copper thin film layer 20 is 1 μm or more, the transmission characteristics of the FPC are further improved. When the thickness of the electroplated copper thin film layer 20 is not more than the upper limit of the above range, the electromagnetic wave shield film 1 can be thinned. In addition, the productivity and flexibility of the electromagnetic wave shielding film 1 are improved.

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

<< Conductive Adhesive Layer >>
The conductive adhesive layer has at least conductivity in the thickness direction and has adhesiveness.
As the conductive adhesive layer, the anisotropic conductive adhesive layer 24 which has conductivity in the thickness direction and does not have conductivity in the surface direction, or has conductivity in the thickness direction and the surface direction, etc. The anisotropic conductive adhesive layer 26 can be mentioned. As the conductive adhesive layer, the conductive adhesive layer can be thinned and the amount of conductive particles is reduced, and as a result, the electromagnetic wave shielding film 1 can be thinned and the flexibility of the electromagnetic wave shielding film 1 is improved. , The anisotropic conductive adhesive layer 24 is preferable. As the conductive adhesive layer, the isotropic conductive adhesive layer 26 is preferable from the viewpoint that it can sufficiently function as an electromagnetic wave shielding layer.

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

Examples of the adhesive include a solvent volatilization type adhesive, a thermosetting adhesive, and a mixture thereof.
Examples of the solvent volatilization type adhesive include those containing a thermoplastic resin and a solvent.
Examples of the thermosetting adhesive include those containing a thermosetting resin and a curing agent.

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

Examples of the thermosetting resin include epoxy resin, phenol resin, amino resin, alkyd resin, urethane resin, synthetic rubber, ultraviolet curable acrylate resin and the like. As the thermosetting resin, an epoxy resin is preferable because it has excellent heat resistance.
Examples of the curing agent include known curing agents depending on the type of thermosetting resin.
The conductive adhesive layer containing the thermosetting adhesive may be in an uncured state or in a B-staged state.

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

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

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, and more preferably 4 μm or more and 16 μm or less. When the average particle diameter of the conductive particles 24b is at least 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 (following the shape of the through holes of the insulating film) can be ensured, and the insulating film The inside of the through hole can be sufficiently filled with the conductive adhesive.

The average particle diameter of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.2 μm or more and 1 μm or less. When the average particle diameter of the conductive particles 26b is equal to or greater than the lower limit of the above range, the number of contact points of the conductive particles 26b increases, and the conductivity in the three-dimensional direction can be stably increased. When the average particle diameter 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 holes of the insulating film) can be ensured, and the insulating film The inside of the through hole 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 10% by volume, out of 100% by volume of the anisotropic conductive adhesive layer 24. The following is more preferable. When the ratio of the conductive particles 24b is equal to or higher than the lower limit of the above range, the conductivity of the anisotropic conductive adhesive layer 24 becomes good. When the proportion of the conductive particles 24b is not more than the upper limit of the above range, the adhesiveness and fluidity (following the shape of the through hole of the insulating film) of the anisotropic conductive adhesive layer 24 are improved. In addition, the flexibility of the electromagnetic wave shielding film 1 is improved.

The proportion of the conductive particles 26b in the isotropic conductive adhesive layer 26 is preferably 50% by volume or more and 80% by volume or less, preferably 60% by volume or more and 70% by volume, out of 100% by volume of the isotropic conductive adhesive layer 26. The following is more preferable. When the ratio of the conductive particles 26b is equal to or higher than the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 becomes good. When the proportion of the conductive particles 26b is not more than the upper limit of the above range, the adhesiveness and fluidity (following the shape of the through hole of the insulating film) of the isotropic conductive adhesive layer 26 are improved. In addition, the flexibility of the electromagnetic wave shielding film 1 is improved.

The surface resistance of the anisotropic conductive adhesive layer 24 ^{is preferably 1 × 10 4} Ω or more and 1 × 10 ¹⁶ Ω or less, and more preferably 1 × 10 ⁶ Ω or more and 1 × 10 ¹⁴ Ω or less. When the surface resistance of the anisotropic conductive adhesive layer 24 is at least the lower limit of the above range, the content of the conductive particles 24b can be suppressed to a low level. If 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 anisotropy in practical use.

The surface resistance of the isotropic conductive adhesive layer 26 is preferably 0.05 Ω or more and 2.0 Ω or less, and more preferably 0.1 Ω or more and 1.0 Ω or less. When the surface resistance of the isotropic conductive adhesive layer 26 is equal to or higher than the lower limit of the above range, the content of the conductive particles 26b is suppressed to a low level, the viscosity of the conductive adhesive does not become too high, and the coatability is further improved. It will be good. Further, the fluidity of the isotropic conductive adhesive layer 26 (following the shape of the through hole of the insulating film) can be further ensured. 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 anisotropic conductive adhesive layer 24 is preferably 3 μm or more and 25 μm or less, and more preferably 5 μm or more and 15 μm or less. When the thickness of the anisotropic conductive adhesive layer 24 is equal to or greater than the lower limit of the above range, the fluidity of the anisotropic conductive adhesive layer 24 (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 not more than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. In addition, the flexibility of the electromagnetic wave shielding film 1 is improved.

The thickness of the isotropic conductive adhesive layer 26 is preferably 5 μm or more and 20 μm or less, and more preferably 7 μm or more and 17 μm or less. When the thickness of the isotropic conductive adhesive layer 26 is at least the lower limit of the above range, the conductivity of the isotropic conductive adhesive layer 26 becomes good, and the isotropic conductive adhesive layer 26 can sufficiently function as an electromagnetic wave shielding layer. Further, 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 of the insulating film can be sufficiently filled with the conductive adhesive, so that the resistance can be improved. Foldability can be ensured, and the isotropic conductive adhesive layer 26 does not tear even if it is repeatedly bent. When the thickness of the isotropic conductive adhesive layer 26 is not more than the upper limit of the above range, the electromagnetic wave shielding film 1 can be thinned. In addition, the flexibility of the electromagnetic wave shielding film 1 is improved.

<First release film>
The first release film 30 serves as a protective film for the insulating resin layer 10, and improves the handleability of the electromagnetic wave shielding film 1. The first release film 30 is peeled off from the insulating resin layer 10 after the electromagnetic wave shielding film 1 is attached to the printed wiring board with the insulating film.

The first release film 30 has, for example, a base material layer 32 and a pressure-sensitive adhesive layer or a mold release agent layer 34 provided on the surface of the base material layer 32 on the insulating resin layer 10 side. In the present specification, the pressure-sensitive adhesive layer or the mold release agent layer 34 is also referred to as the pressure-sensitive adhesive layer / mold release agent layer 34.
The first release film 30 may have the pressure-sensitive adhesive layer / release agent layer 34 directly provided on the surface of the base material layer 32; the pressure-sensitive adhesive layer / release agent on the surface of the insulating resin layer 10. After the layer 34 is provided, the base material layer 32 is attached to the surface of the pressure-sensitive adhesive layer / release agent layer 34, whereby the pressure-sensitive adhesive layer / release agent layer 34 is provided on the surface of the base material layer 32. There may be.

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

The thickness of the base material layer 32 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 150 μm or less, and further preferably 25 μm or more and 100 μm or less. When the thickness of the base material layer 32 is at least the lower limit of the above range, the handleability of the electromagnetic wave shielding film 1 is good. When the thickness of the base material layer 32 is not more than the upper limit of the above range, heat is easily transferred to the adhesive layer 22 when the electromagnetic wave shielding film 1 is hot-pressed on the printed wiring board with an insulating film.

A pressure-sensitive adhesive layer 34 or a release agent layer 34 is arranged between the base material layer and the insulating resin layer.
Since the first release film 30 has the adhesive layer or the release agent layer 34, when the second release film 40 is peeled from the adhesive layer 22, the electromagnetic wave shield film 1 is heated to a printed wiring board or the like. When affixed by a press, the first release film 30 is prevented from peeling from the insulating resin layer 10, and the first release film 30 can sufficiently serve as a protective film.
As the pressure-sensitive adhesive, a known pressure-sensitive adhesive may be used.
Further, the mold release agent layer 34 is formed by subjecting the surface of the base material layer 32 to a mold release treatment with a mold release agent. Since the first release film 30 has the release agent layer 34, when the first release film 30 is peeled from the insulating resin layer 10, the first release film 30 can be easily peeled off, and the insulating resin. The layer 10 is less likely to break.
As the release agent, a known release agent may be used.

The thickness of the pressure-sensitive adhesive layer 34 is preferably 0.05 μm or more and 50.0 μm or less, and more preferably 0.1 μm or more and 25.0 μm or less. When the thickness of the pressure-sensitive adhesive layer 34 is within the above range, the surface of the first release film 30 has appropriate adhesiveness.
The thickness of the release agent layer 34 is preferably 0.05 μm or more and 2.0 μm or less, and more preferably 0.1 μm or more and 1.5 μm or less. When the thickness of the release agent layer 34 is within the above range, the first release film can be more easily peeled off.

<Second release film>
The second release film 40 protects the adhesive layer 22 and improves the handleability of the electromagnetic wave shielding film 1. The second release film 40 is peeled off from the adhesive layer 22 before the electromagnetic wave shielding film 1 is attached to the printed wiring board with an insulating film.

The second release film 40 has, for example, a base material layer 42 and a release agent layer or a pressure-sensitive adhesive layer 44 provided on the surface of the base material layer 42 on the conductive adhesive layer side.
In the present specification, the release agent layer or the pressure-sensitive adhesive layer 44 is also referred to as a release agent layer / pressure-sensitive adhesive layer 44.

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

A mold release agent layer 44 or an adhesive layer 44 is arranged between the base material layer 42 and the adhesive layer 22.
The release agent layer 44 is formed by subjecting the surface of the base material layer 42 to a mold release treatment with a release agent. Since the second release film 40 has the release agent layer 44, when the second release film 40 is peeled from the adhesive layer 22, the second release film 40 can be easily peeled off, and the adhesive. The layer 22 is less likely to break.
As the release agent, a known release agent may be used.

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

As the pressure-sensitive adhesive layer 44, the same pressure-sensitive adhesive layer 34 as described in the above section <1st release film> can be used.

<Structure of electromagnetic wave shield film>
In the present invention, the electromagnetic wave shielding film may have at least an insulating resin layer, an electroplated copper thin film layer, and an adhesive layer. The electromagnetic wave shielding film may or may not include a first release film and a second release film.
Therefore, in the present specification, the case where the insulating resin layer, the electrolytically plated copper thin film layer, and the adhesive layer include the first release film and / or the second release film is referred to as an electromagnetic wave shielding film, and these Sometimes it is called an electromagnetic wave shield film without including the release film.

<Thickness of electromagnetic wave shield film>
The thickness of the electromagnetic wave shield film 1 (excluding the release film) is preferably 5 μm or more and 45 μm or less, and more preferably 5 μm or more and 30 μm or less. If the thickness of the electromagnetic wave shielding film 1 (excluding the release film) is at least the lower limit of the above range, it is unlikely to break when the first release film 30 is peeled off. When the thickness of the electromagnetic wave shielding film 1 (excluding the release film) 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 thinned.

<Electromagnetic wave shield film with suppressed light reflection on the surface of the insulating resin layer>
As a further preferable embodiment of the electromagnetic wave shielding film according to the present invention described above, the following electromagnetic wave shielding film can be mentioned.
In order to suppress the reflection of light on the surface of the insulating resin layer, an uneven shape may be formed on the surface of the insulating resin layer. For example, insulating particles may be contained in the insulating resin layer to form an uneven shape on the surface of the insulating resin layer. Alternatively, when the electromagnetic wave shielding film has a first release film adjacent to the side opposite to the electrolytically plated copper thin film layer of the insulating resin layer, the irregularities on the surface of the first release film are transferred. , An uneven shape may be formed on the surface of the insulating resin layer.
As a method for causing the unevenness of the surface of the first release film to be transferred to the surface of the insulating resin layer, for example, the unevenness on the surface of the base material layer with respect to the base material layer in the first release film. The shape can be formed, and insulating particles can be contained in the layer with respect to the pressure-sensitive adhesive layer or the release agent layer in the first release film.

The reason why it is better to suppress the reflection of light on the surface of the insulating resin layer as much as possible is as follows.
After the electromagnetic wave shielding film is attached to the surface of the flexible printed wiring board, the first release film is peeled from the insulating resin layer. At that time, the insulating resin layer after the first release film is peeled off. The surface is smooth by transferring the surface shape of the first release film, and has a high mirror gloss. However, when the surface glossiness of the surface of the insulating resin layer, which is the outermost surface of the flexible printed wiring board with the electromagnetic wave shielding film, is high, there are the following problems.
-When printing is performed on the surface of the insulating resin layer, the visibility of the printed characters and patterns deteriorates due to the reflection of light.
-The optical sensor or the like may be affected by the reflection of light from the insulating resin layer around the optical sensor (CCD image sensor, CMOS image sensor, etc. of the camera module).
-Scratches on the surface of the insulating resin layer are easily noticeable.
Therefore, in order not to cause these problems, it is effective to form an uneven shape on the surface of the insulating resin layer and suppress the reflection of light on the surface of the insulating resin layer as described above.

The insulating particles contained in the above-mentioned insulating resin layer or the pressure-sensitive adhesive layer / release agent layer are particularly limited as long as the surfaces of the insulating resin layer and the pressure-sensitive adhesive layer / release agent layer can be provided with irregularities. However, it can be appropriately selected depending on the intended purpose, but for example, inorganic particles, polymer particles and the like can be used.
Examples of the inorganic particles include silica particles, calcium carbonate particles, titanium oxide particles, alumina particles and the like.
Examples of the polymer particles include acrylic particles and melamine particles.

In order to form an uneven shape on the surface of the base material layer, for example, the surface of the base material layer may be roughened by the following method.
Examples include a method of spraying abrasive grains on the surface of the base material layer 32 (blast treatment), a method of transferring the unevenness of the embossing roll to the surface of the base material layer 32 (embossing treatment), a method of including particles in the base material layer 32, and the like. Be done.
In addition, for example, the electromagnetic wave shield film 1 having an uneven shape formed on the surface of the insulating resin layer can be produced by using the method disclosed in Japanese Patent Application Laid-Open No. 2018-166167.

FIG. 10 is a cross-sectional view showing a fifth embodiment of the electromagnetic wave shielding film according to the present invention.
In the electromagnetic wave shielding film 1 of the fifth embodiment shown in FIG. 10, the pressure-sensitive adhesive layer 34 is composed of the pressure-sensitive adhesive 34a and the insulating particles 34b with respect to the electromagnetic wave shielding film 1 of the first embodiment shown in FIG. The difference is that the surface of the pressure-sensitive adhesive layer 34 is unevenly formed by the insulating particles 34b. Further, the electromagnetic wave shielding film 1 of the fifth embodiment shown in FIG. 10 has a surface of the base material layer 32 opposite to the adhesive layer of the electromagnetic wave shielding film 1 of the first embodiment shown in FIG. The difference is that it is roughened and has an uneven shape.

(Manufacturing method of electromagnetic wave shield film)
The method for producing an electromagnetic wave shield film of the present invention is characterized in that an insulating resin layer is provided on one surface and an adhesive layer is provided on the other surface of the electroplated copper thin film layer formed by the electroplating method. .. Compared to the case where metal is vapor-deposited on the surface of the insulating resin layer to form a metal thin film layer, it is better to provide the insulating resin layer on the surface of the electroplated copper thin film layer to adhere the insulating resin layer to the electrolytically plated copper thin film layer. The property becomes good. Further, the method for producing an electromagnetic wave shielding film of the present invention can produce an electromagnetic wave shielding film having good adhesiveness between an adhesive layer and an electroplated copper thin film layer.
Further, in the method for producing an electromagnetic wave shield film of the present invention, since the copper thin film layer is formed by an electrolytic plating method, a copper thin film layer in a good film-forming state can be obtained even with a film thickness of 1 μm or more, and the copper thin film layer can be obtained for FPC. An electromagnetic wave shield film having excellent shielding properties and transmission characteristics can be manufactured. Moreover, the method for producing an electromagnetic wave shielding film of the present invention can produce an electromagnetic wave shielding film by a simple and low-cost method.

The method for producing an electromagnetic wave shielding film of the present invention has the following steps (a) to (c).
Step (a): A step of providing an electroplated copper thin film layer on the surface of the carrier copper foil by an electroplating method, if necessary.
Step (b): A step of providing an adhesive layer on the surface of the electroplated copper thin film layer with respect to the electroplated copper thin film layer provided on the surface of the carrier copper foil by the electroplating method.
Step (c): A step of peeling the carrier copper foil from the electroplated copper thin film layer and providing an insulating resin layer on the surface of the electroplated copper thin film layer opposite to the adhesive layer.

<Step (a)>
A mold release agent layer may be arranged on the surface of the carrier copper foil, if necessary.
As the release agent of the release agent layer, a known release agent may be used.

As a method for producing the electroplated copper thin film layer, for example, the following method can be used.
A carrier copper foil 102 provided with a release agent layer 104 on the surface is prepared. Here, the release agent layer can be formed on the surface of the carrier copper foil by a known method such as immersing the carrier copper foil in an aqueous solution of chromium trioxide to chromate the surface of the carrier copper foil.
Next, the carrier copper foil 102 is immersed in a sulfuric acid / copper sulfate bath solution to form an electrolytically plated copper thin film layer (electrolytic copper foil) 20 on the mold release agent layer 104 of the carrier copper foil 102 by an electrolytic plating method. ..
As described above, according to the electroplating method, the precipitated copper is laminated to form a copper film. Therefore, by producing by the electroplating method, a copper thin film layer having a roughened surface can be formed. it can. The fact that the surface of the electroplated copper thin film layer has an uneven shape of a desired size is also effective in further enhancing the adhesiveness between the electroplated copper thin film layer and the adhesive layer. ..
The arithmetic mean roughness (Ra) of the surface of the electroplated copper thin film layer on the adhesive layer side is preferably, for example, 0.5 μm or more and 2.5 μm or less. When the arithmetic mean roughness (Ra) is in the range of 0.5 μm or more and 2.5 μm or less, the effect of further improving the adhesiveness between the electroplated copper thin film layer and the adhesive layer can be expected.

The step (a) may be omitted by obtaining a commercially available laminate in which the electrolytic copper foil is provided on the carrier copper foil.

<Step (b)>
In the step (b), the second release film with an adhesive layer provided with an adhesive layer on the surface of the second release film is adhered to the surface of the electrolytically plated copper thin film layer with the electrolytically plated copper thin film layer. It may be attached so as to be in contact with the agent layer; the adhesive layer may be provided directly on the surface of the electrolytically plated copper thin film layer. Further, after the adhesive layer is provided on the surface of the electroplated copper thin film layer, a second release film may be attached to the surface of the adhesive layer.

As a method of providing an adhesive layer on the surface of the second release film or electroplated copper thin film layer, an adhesive, a solvent and, if necessary, conductivity are provided on the surface of the second release film or electroplated copper thin film layer. Examples thereof include a method of applying a coating liquid containing sex particles and drying the coating liquid.

<Step (c)>
In the step (c), the carrier copper foil is peeled off from the electroplated copper thin film layer. At this time, when the electromagnetic wave shielding film has a second release film adjacent to the side opposite to the electrolytically plated copper thin film layer of the adhesive layer, according to the production method of the present invention, the electrolytically plated copper thin film layer and the carrier It is possible to easily adjust the peeling force at the interface with the copper foil to be smaller than the peeling force at the interface between the adhesive layer and the second release film.
By making the peeling force at the interface between the electrolytically plated copper thin film layer and the carrier copper foil smaller than the peeling force at the interface between the adhesive layer and the second release film, the electrolytically plated copper thin film layer, the adhesive layer, and the second The carrier copper foil can be peeled off reasonably without giving an excessive load to the laminate with the release film. As a result, it is possible to form an electromagnetic wave shielding film in which peeling between each layer of the electroplated copper thin film layer, the adhesive layer, and the second release film is less likely to occur.
The peeling force at the interface between the electroplated copper thin film layer and the carrier copper foil is preferably, for example, 0.1 N / cm or more and 1.5 N / cm or less. On the other hand, the peeling force at the interface between the adhesive layer and the second release film is preferably, for example, 0.2 N / cm or more and 2.5 N / cm or less. When the second release film has the release agent layer / adhesive layer 44 on the base material layer 42, the above-mentioned "peeling force at the interface between the adhesive layer and the second release film". Is read as "peeling force at the interface between the adhesive layer and the release agent layer / adhesive layer 44".

As a method of providing an insulating resin layer on the surface of the electroplated copper thin film layer opposite to the adhesive layer, a composition containing a curable resin and a curing agent is applied to the surface of the electroplated copper thin film layer. Method of curing or curing; A method of applying a coating liquid containing a curable resin, a curing agent and a solvent to the surface of an electroplated copper thin film layer, drying the film, and then semi-curing or curing the electroplated copper thin film layer. A method of applying a coating liquid containing a thermoplastic resin and a solvent to the surface of the sheet and drying the surface; a method of melt-molding a composition containing the thermoplastic resin on the surface of the electroplated copper thin film layer and the like can be mentioned. As a method of providing the insulating resin layer on the surface of the electrolytically plated copper thin film layer, a resin material ( A method in which a coating liquid containing a combination of a curable resin and a curing agent or a thermoplastic resin) and a solvent is applied, dried, and then semi-cured or cured as necessary is preferable.

In the step (c), the first release film may be provided on the surface of the insulating resin layer.
As a method of providing the first release film on the surface of the insulating resin layer, a first release film having a base material layer and an adhesive layer or a release agent layer on the surface of the insulating resin layer is provided with an insulating resin. A method of sticking the layer so that the pressure-sensitive adhesive layer or the release agent layer is in contact with each other; after providing the pressure-sensitive adhesive layer or the release agent layer on the surface of the insulating resin layer, the first surface of the pressure-sensitive adhesive layer or the release agent layer is formed. A method of providing the first release film on the surface of the insulating resin layer by attaching the base material layer of the release film of 1 can be mentioned.

<One Embodiment of Manufacturing Method of Electromagnetic Wave Shield Film>
Hereinafter, a method for manufacturing the electromagnetic wave shielding film 1 of the first embodiment shown in FIG. 1 will be described with reference to FIGS. 5 and 6.

Step (a):
As shown in FIG. 5, the release agent layer 104 is arranged on the carrier copper foil 102, and the electroplated copper thin film layer 20 is provided on the surface on the release agent layer 104 side by an electroplating method. In this way, a carrier copper foil with an electrolytically plated copper thin film layer (carrier copper foil with an electrolytic copper foil) is obtained.

Step (b1):
As shown in FIG. 5, a coating liquid for forming an adhesive layer containing an adhesive 24a, conductive particles 24b, and a solvent is applied to the surface of the carrier copper foil with an electrolytically plated copper thin film layer on the electrolytically plated copper thin film layer side. , Dry to provide the heteroconductive adhesive layer 24 (adhesive layer 22). In this way, a carrier copper foil with an electrolytically plated copper thin film layer with an adhesive layer is obtained.

Step (b2):
As shown in FIG. 5, the release agent layer 44 side of the second release film 40 having the base material layer 42 and the release agent layer / adhesive layer 44, and the electrolytically plated copper thin film layer with the adhesive layer are attached. The carrier copper foil is bonded to each other so that the release agent layer 44 and the anisotropic conductive adhesive layer 24 are in contact with each other to obtain a laminate.

Step (c1):
As shown in FIG. 6, in the laminate obtained in the step (b2), the carrier copper foil 102 is peeled off from the electroplated copper thin film layer 20.

Step (c2):
As shown in FIG. 6, a coating liquid for forming an insulating resin layer containing a resin material and a solvent is applied to the surface of the electroplated copper thin film layer 20 and dried to provide the insulating resin layer 10.

Step (c3):
As shown in FIG. 6, the first release film 30 having the base material layer 32 and the adhesive layer 34 is brought into contact with the surface of the insulating resin layer 10 so that the insulating resin layer 10 and the adhesive layer 34 are in contact with each other. Attach to obtain an electromagnetic wave shield film 1.

When the electromagnetic wave shielding film 1 is the electromagnetic wave shielding film 1 of the third embodiment shown in FIG. 3, it can be manufactured according to the steps (c1) to (c3) of FIG.
In this case, in the step (c2), as shown in FIG. 7, an adhesive layer 10b for the insulating resin layer is arranged on the surface of the electrolytically plated copper thin film layer 20, and an adhesive layer 10b for the insulating resin layer is further arranged. A film-shaped insulating resin layer 10a is arranged on the film.

<Effect>
In the method for producing the electromagnetic wave shield film 1 described above, since the insulating resin layer 10 is provided on the surface of the electroplated copper thin film layer 20, metal is applied to the surface of the insulating resin layer having high hardness as in the conventional case. An electromagnetic wave shielding film 1 having better adhesion between the insulating resin layer 10 and the electroplated copper thin film layer 20 can be manufactured as compared with the case where the metal thin film layer is formed by thin film deposition.
Further, the method for producing the electromagnetic wave shielding film 1 of the present invention can produce the electromagnetic wave shielding film 1 having good adhesiveness between the adhesive layer 22 and the electroplated copper thin film layer 20.

<Other Embodiments>
The electromagnetic wave shield film in the present invention has an insulating resin layer, an electrolytically plated copper thin film layer adjacent to the insulating resin layer, and an adhesive layer adjacent to the side opposite to the insulating resin layer of the electrolytically plated copper thin film layer. It suffices, and is not limited to the embodiment of the illustrated example.
For example, the insulating resin layer may be two or more layers.
The first release film may have a release agent layer instead of the pressure-sensitive adhesive layer.
The second release film may have a pressure-sensitive adhesive layer instead of the release agent layer.
The first release film or the second release film may have no pressure-sensitive adhesive layer or release agent layer and may consist only of a base material layer.
If the insulating resin layer has sufficient flexibility and strength, the first release film may be omitted.
If the surface of the adhesive layer has little tackiness, the second release film may be omitted.

[Manufacturing method of printed wiring board with electromagnetic wave shield film]
The present invention defines a method for manufacturing a printed wiring board with an electromagnetic wave shielding film.
In the method for manufacturing a printed wiring board with an electromagnetic wave shielding film of the present invention, the following steps (d) and (e) are carried out after manufacturing the electromagnetic wave shielding film by the above-mentioned manufacturing method for the electromagnetic wave shielding film of the present invention. ..
Step (d): A step of providing an insulating film on the surface of the printed wiring board on the side where the printed circuit is provided to obtain a printed wiring board with the insulating film.
Step (e): When the electromagnetic wave shielding film has a second release film, after peeling the second release film from the electromagnetic wave shielding film, the printed wiring board with the insulating film and the electromagnetic wave shielding film are separated from each other by the insulating film. A process of obtaining a printed wiring board with an electromagnetic wave shielding film by adhering an adhesive layer to the surface of an insulating film by stacking the adhesive layers on the surface of the film so as to make contact with each other and pressing them.

The method for manufacturing the printed wiring board with the electromagnetic wave shielding film of the present invention will be described in detail later. First, in the manufacturing method of the present invention, a printed wiring board with an electromagnetic wave shielding film to which the electromagnetic wave shielding film is adhered will be described.

(Printed wiring board with electromagnetic wave shield film)
FIG. 8 is a cross-sectional view showing a first embodiment of a printed wiring board with an electromagnetic wave shielding film obtained by the manufacturing method of the present invention.
The flexible printed wiring board 2 with an electromagnetic wave shielding film includes a flexible printed wiring board 50, an insulating film 60, and an electromagnetic wave shielding film 1 of the first embodiment.
The flexible printed wiring board 50 is provided with a printed circuit 54 on at least one side of the 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. Further, the anisotropic conductive adhesive layer 24 is electrically connected to the print circuit 54 through a through hole (not shown) formed in the insulating film 60.
In the flexible printed wiring board 2 with an electromagnetic wave shielding film, the second release film 40 is peeled off from the anisotropic conductive adhesive layer 24.
When the first release film 30 is no longer needed in the flexible printed wiring board 2 with the electromagnetic wave shielding film, the first release film 30 is peeled off from the insulating resin layer 10.

In the vicinity of the printed circuit 54 (signal circuit, ground circuit, ground layer, etc.) excluding the portion having a through hole, the electroplated copper thin film layer 20 of the electromagnetic wave shielding film 1 is formed with the insulating film 60 and the anisotropic conductive adhesive layer. They are arranged so as to face each other apart from each other via 24.
The separation distance between the printed circuit 54 and the electroplated copper thin film layer 20 excluding 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, and 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 such as 100Ω, the line width of the signal circuit must be reduced, and the variation in the line width is the variation in the characteristic impedance. Therefore, the reflected resonance noise due to the impedance mismatch can easily get on the electric signal. If the separation distance is larger than 200 μm, the flexible printed wiring board 2 with the electromagnetic wave shielding film becomes thick, and the flexibility becomes insufficient.

FIG. 11 is a cross-sectional view showing a second embodiment of a printed wiring board with an electromagnetic wave shielding film obtained by the manufacturing method of the present invention.
The printed wiring board with the electromagnetic wave shielding film of the second embodiment shown in FIG. 11 is the printed wiring board with the electromagnetic wave shielding film of the first embodiment shown in FIG. The difference is that it is changed to an electromagnetic wave shield film.
Further, when the first release film 30 is no longer needed in the flexible printed wiring board 2 with the electromagnetic wave shielding film, the first release film 30 is peeled from the insulating resin layer 10 as shown in FIG. Will be done. After peeling off the first release film 30, the surface of the insulating resin layer 10 is formed by transferring the unevenness of the surface of the pressure-sensitive adhesive layer / release agent layer 34 of the first release film 30. Is exposed.

<Flexible printed wiring board>
The flexible printed wiring board 50 is a printed circuit (power supply circuit, ground circuit, ground layer, etc.) obtained by processing a copper foil of a copper-clad laminate into a desired pattern by a known etching method.
As the copper-clad laminate, a copper foil is attached to one or both sides of the base film 52 via an adhesive layer (not shown); a resin solution or the like forming the base film 52 is cast on the surface of the copper foil. Things etc. can be mentioned.
Examples of the material of the adhesive layer include epoxy resin, polyester, polyimide, polyamide-imide, polyamide, phenol resin, urethane resin, acrylic resin, melamine resin and the like.
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 25 μm or less, and more preferably 10 μm or more and 25 μm or less from the viewpoint of flexibility.

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

<Insulation film>
The insulating film 60 has an adhesive layer (not shown) formed on one side of the insulating film main 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 main 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 (carboxy-modified nitrile rubber, etc.) for imparting flexibility.
The thickness of the adhesive layer is preferably 1 μm or more and 100 μm or less, and more preferably 1.5 μm or more and 60 μm or less.

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

(Manufacturing method of printed wiring board with electromagnetic wave shield film)
The method for manufacturing a printed wiring board with an electromagnetic wave shielding film of the present invention has the following steps (d) to (g).
Step (d): A step of providing an insulating film on the surface of the printed wiring board on the side where the printed circuit is provided to obtain a printed wiring board with the insulating film.
Step (e): When the electromagnetic wave shielding film has a second release film, after peeling the second release film from the electromagnetic wave shielding film, the printed wiring board with the insulating film and the electromagnetic wave shielding film are separated from each other by the insulating film. The process of obtaining a printed wiring board with an electromagnetic wave shielding film by crimping the adhesive layer to the surface of the insulating film by stacking the adhesive layers on the surface of the film so that they are in contact with each other and pressing them.
Step (f): When the electromagnetic wave shield film has the first release film, after the step (e), when the first release film is no longer needed, the first release film is removed from the electromagnetic wave shield film. The process of peeling off.
Step (g): When the adhesive contained in the adhesive layer is a thermosetting adhesive, it is bonded between steps (e) and step (f) or after step (f), if necessary. The process of main curing the agent layer.

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

<Step (d)>
As shown in FIG. 9, an insulating film 60 having a through hole 62 formed at a position corresponding to the printed circuit 54 is superposed on the flexible printed wiring board 50, and an adhesive layer of the insulating film 60 is formed on the surface of the flexible printed wiring board 50. A flexible printed wiring board 3 with an insulating film is obtained by adhering (not shown) and curing the adhesive layer. The adhesive layer of the insulating film 60 may be temporarily adhered to the surface of the flexible printed wiring board 50, and the adhesive layer may be mainly cured in the step (g).
The adhesive layer is adhered and cured by, for example, hot pressing with a press machine (not shown) or the like.

<Step (e)>
As shown in FIG. 9, the insulating film 60 is formed by superimposing the electromagnetic wave shielding film 1 from which the second release film 40 has been peeled off on the flexible printed wiring plate 3 with the insulating film and pressing (preferably heat pressing) the insulating film 60. Flexible printed wiring board 2 with an electromagnetic wave shielding film in which the anisotropic conductive adhesive layer 24 is crimped to the surface and the anisotropic conductive adhesive layer 24 is electrically connected to the printed circuit 54 through the through hole 62. To get.

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

<Step (f)>
As shown in FIG. 9, when the first release film 30 is no longer needed, the first release film 30 is peeled off from the insulating resin layer 10.

<Effect>
In the method for manufacturing the flexible printed wiring board 2 with the electromagnetic wave shielding film described above, since the electromagnetic wave shielding film 1 is used, the adhesiveness between the insulating resin layer 10 and the electrolytically plated copper thin film layer 20 in the electromagnetic wave shielding film 1 In addition, a flexible printed wiring board 2 with an electromagnetic wave shielding film having excellent adhesiveness between the adhesive layer 22 and the electrolytically plated copper thin film layer 20 can be manufactured.

<Other Embodiments>
The printed wiring board with an electromagnetic wave shielding film in the present invention includes a printed wiring board, an insulating film adjacent to the surface of the printed wiring board on the side where the printed circuit is provided, and an electromagnetic wave shield having an adhesive layer adjacent to the insulating film. Anything may have a film, and the embodiment is not limited to the illustrated example.
For example, the flexible printed wiring board may have a ground layer on the back surface side. Further, the flexible printed wiring board may have printed circuits on both sides, and an insulating film and an electromagnetic wave shielding film may be attached to both sides.
An inflexible rigid printed circuit board may be used instead of the flexible printed wiring board.
Instead of the electromagnetic wave shielding film 1 of the first embodiment, the electromagnetic wave shielding film 1 of the second to fifth embodiments may be used.

The present invention will be described in more detail with reference to Examples below, but the scope of the present invention is not limited to these Examples.

(Adhesiveness)
The adhesiveness between the insulating resin layer and the electroplated copper thin film layer was evaluated as follows.
Adhesion test (cross-cut method) was carried out in accordance with JIS K 5600-5-6: 1999 (ISO 2409: 1992). The cut was made from the electroplated copper thin film layer side. Adhesiveness was evaluated from the remaining number of 5 × 5 = 25 cells.

(Example 1)
As a coating liquid for forming an adhesive layer, 100 parts by mass of a thermosetting adhesive (epoxy resin (DIC, EXA-4816)) and 20 parts by mass of a curing agent (Ajinomoto Fine Techno, PN-23). 6 parts by mass of conductive particles (copper particles having an average particle diameter B: 5.02 μm) dissolved or dispersed in 200 parts by mass of a solvent (methyl ethyl ketone). I prepared.

As a coating liquid for forming an insulating resin layer, 100 parts by mass of bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., jER® 828) and a curing agent (manufactured by Showa Denko Co., Ltd., Shoamine X (registered trademark)) A coating material was prepared in which 20 parts by mass, 2 parts by mass of 2-ethyl-4-methylimidazole, and 2 parts by mass of carbon black were dissolved in 200 parts by mass of a solvent (methyl ethyl ketone).

Step (b1):
An adhesive layer forming coating solution is applied to the surface of an electrolytic copper foil with a copper carrier (carrier copper foil: 18 μm, electrolytic copper foil: 3 μm, arithmetic mean roughness (Ra) 1.2 μm on the surface on the adhesive layer side). It was applied to a thickness of 25 μm using a comma coater. The coating film is dried at 100 ° C. for 1 minute to provide an anisotropic conductive adhesive layer (thickness: 10 μm, surface resistance: 1.0 × 10 ¹² Ω or more), and an electrolytic copper foil with a copper carrier with an adhesive layer. Got

Step (b2):
The second release film (manufactured by Panac, PanaProtect (registered trademark) GN, adhesive film, PET thickness: 75 μm) and the electrolytic copper foil with a copper carrier with an adhesive layer are different from the release agent layer. The laminate was obtained by laminating them so as to be in contact with the conductive adhesive layer.

Step (c1):
In the laminate obtained in the step (b2), the carrier copper foil was peeled off from the electroplated copper thin film layer.
When the state of the electroplated copper thin film layer was confirmed using an optical microscope, no cracks were generated in the electroplated copper thin film layer.

The release agent for the adhesive layer and the second release film in the laminate of the carrier copper foil with the electrolytically plated copper thin film layer with the adhesive layer obtained in the above step (b2) and the second release film. The release force at the interface with the layer was 0.6 N / cm.
On the other hand, the peeling force at the interface between the electroplated copper thin film layer and the carrier copper foil in the electrolytic copper foil with a copper carrier used in the above step (b1) was 0.5 N / cm.

Step (c2):
A coating liquid for forming an insulating resin layer was applied to the surface of the electroplated copper thin film layer using a # 4 bar coater. The coating film was dried at 100 ° C. for 1 minute, and an insulating resin layer (thickness: 10 μm, surface resistance: 1.0 × 10 ¹² Ω or more) was provided on the surface of the electroplated copper thin film layer.
When the adhesiveness between the insulating resin layer and the electroplated copper thin film layer was evaluated by the cross-cut method for the sample cut from the laminate obtained in the step (c2), the remaining number was 25/25.

Step (c3):
A first release film (Panac Corporation, PanaProtect (registered trademark) GN, adhesive film, PET thickness: 50 μm) is attached to the surface of the insulating resin layer so that the insulating resin layer and the adhesive layer are in contact with each other. Then, an electromagnetic wave shielding film was obtained.

Step (d):
An insulating adhesive composition is applied to the surface of a polyimide film (insulating film body) having a thickness of 25 μm so that the dry film thickness becomes 25 μm to form an adhesive layer, and an insulating film (thickness: 50 μm) is applied. Obtained. A through hole (hole diameter: 800 μm) was formed at a position corresponding to the ground of the printed circuit.

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

Step (e):
An electromagnetic wave shield film from which the second release film was peeled off was placed on a flexible printed wiring board with an insulating film, and heat-pressed with a hot press device at a hot plate temperature: 180 ° C. and a load of 3 MPa for 1 minute to obtain the insulating film. An anisotropic conductive adhesive layer was adhered to the surface.

Step (f):
The first release film was peeled off from the insulating resin layer to obtain a flexible printed wiring board with an electromagnetic wave shielding film.

The electromagnetic wave shielding film obtained by the manufacturing method of the present invention can be used as an electromagnetic wave shielding member in a flexible printed wiring board for electronic devices such as smartphones, mobile phones, optical modules, digital cameras, game machines, notebook computers, and medical appliances. It is useful.

1 Electromagnetic wave shield film 2 Flexible printed wiring board with electromagnetic wave shield film 3 Flexible printed wiring board with insulating film 10 Insulating resin layer 10a Film-shaped insulating resin layer 10b Adhesive layer for insulating resin layer 20 Electrolytic plated copper thin film layer 22 Adhesive Layer 24 Idiopathic Conductive Adhesive Layer 24a Adhesive 24b Conductive Particles 26 Isotropic Conductive Adhesive Layer 26a Adhesive 26b Conductive Particles 30 First Release Film 32 Base Material Layer 34 Adhesive Layer / Release Agent Layer 40 Second release film 42 Base material layer 44 Release agent layer / Adhesive layer 50 Flexible printed wiring board 52 Base film 54 Print circuit 60 Insulation film 62 Through hole 102 Carrier copper foil 104 Release agent layer

Claims (10)

Insulating resin layer and
The electroplated copper thin film layer adjacent to the insulating resin layer and
This is a method for producing an electromagnetic wave shielding film having an adhesive layer adjacent to the insulating resin layer of the electroplated copper thin film layer on the opposite side.
A method for producing an electromagnetic wave shielding film, which comprises the following steps (b) and (c).
Step (b): A step of providing the adhesive layer on the surface of the electroplated copper thin film layer with respect to the electroplated copper thin film layer provided on the surface of the carrier copper foil by the electroplating method.
Step (c): A step of peeling the carrier copper foil from the electroplated copper thin film layer and providing the insulating resin layer on the surface of the electroplated copper thin film layer opposite to the adhesive layer. The method for producing an electromagnetic wave shielding film according to claim 1, wherein the thickness of the electroplated copper thin film layer is 1 μm or more and 3 μm or less. The method for producing an electromagnetic wave shielding film according to claim 1 or 2, wherein the arithmetic mean roughness (Ra) of the surface of the electroplated copper thin film layer on the adhesive layer side is 0.5 μm or more and 2.5 μm or less. The method for producing an electromagnetic wave shielding film according to any one of claims 1 to 3, wherein the insulating resin layer is a film-shaped insulating resin layer containing an aromatic polyetherketone. The method for producing an electromagnetic wave shielding film according to any one of claims 1 to 4, wherein the insulating resin layer contains insulating particles in the layer. When the electromagnetic wave shielding film has a first release film adjacent to the side of the insulating resin layer opposite to the electroplated copper thin film layer.
The first release film has a base material layer and a pressure-sensitive adhesive layer or a mold release agent layer provided on the surface of the base material layer on the insulating resin layer side.
The method for producing an electromagnetic wave shielding film according to any one of claims 1 to 5, wherein the surface of the base material layer has an uneven shape. When the electromagnetic wave shielding film has a first release film adjacent to the side of the insulating resin layer opposite to the electroplated copper thin film layer.
The first release film has a base material layer and a pressure-sensitive adhesive layer or a mold release agent layer provided on the surface of the base material layer on the insulating resin layer side.
The method for producing an electromagnetic wave shielding film according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer or the release agent layer contains insulating particles in the layer. When the electromagnetic wave shielding film has a second release film adjacent to the side of the adhesive layer opposite to the electroplated copper thin film layer.
Any one of claims 1 to 7, wherein the peeling force at the interface between the electrolytically plated copper thin film layer and the carrier copper foil is smaller than the peeling force at the interface between the adhesive layer and the second release film. The method for manufacturing an electromagnetic wave shielding film described in 1. The peeling force at the interface between the electrolytically plated copper thin film layer and the carrier copper foil is 0.1 N / cm or more and 1.5 N / cm or less, and at the interface between the adhesive layer and the second release film. The method for producing an electromagnetic wave shielding film according to claim 8, wherein the peeling force is 0.2 N / cm or more and 2.5 N / cm or less. After manufacturing the electromagnetic wave shield film by the method for manufacturing the electromagnetic wave shield film according to any one of claims 1 to 9,
A method for manufacturing a printed wiring board with an electromagnetic wave shielding film, which carries out the following steps (d) and (e).
Step (d): A step of providing an insulating film on the surface of the printed wiring board on the side where the printed circuit is provided to obtain a printed wiring board with the insulating film.
Step (e): When the electromagnetic wave shielding film has a second release film, after peeling the second release film from the electromagnetic wave shielding film, the printed wiring board with the insulating film and the electromagnetic wave shielding film. The adhesive layer is laminated on the surface of the insulating film so that the adhesive layer is in contact with the surface of the insulating film, and by pressing these, the adhesive layer is adhered to the surface of the insulating film to obtain a printed wiring board with an electromagnetic wave shielding film. Process.

Images