TW202402154A - Electromagnetic shielding film - Google Patents

Abstract

Provided is an electromagnetic shielding film having both sufficiently high concealment characteristics and anti-scratch characteristics for a surface of a protective layer. This electromagnetic shielding film comprises a protective layer having a first main surface and a second main surface opposing the first main surface, and a shield layer disposed on the second main surface of the protective layer, the electromagnetic shielding film being characterized in that the developed surface area ratio Sdr of the interface of the first main surface is 75.0-250%.

Description

Electromagnetic wave shielding film

The present invention relates to an electromagnetic wave shielding film.

Conventionally, electromagnetic wave shielding films have been attached to printed wiring boards such as flexible printed wiring boards (FPCs) to shield electromagnetic waves from the outside. As a method for shielding a printed wiring board, a method is known in which an electromagnetic wave shielding film having a protective layer and a shielding layer is heated and pressed to adhere to the printed wiring board to form a shielded printed wiring board. In addition, a base film made of polyethylene terephthalate (PET) resin or the like is disposed on the surface of the protective layer of the electromagnetic wave shielding film to protect the protective layer from damage or damage by foreign matter. After the electromagnetic wave shielding film is attached to the printed wiring board, the base film is peeled off. After peeling off the base film, if you touch the electromagnetic wave shielding film with bare hands, fingerprints and stains will adhere to the protective layer of the electromagnetic wave shielding film, resulting in a deterioration in appearance.

In order to solve such problems in Patent Document 1 and Patent Document 2, unevenness is formed on the surface of the protective layer of the electromagnetic wave shielding film so that fingerprints, stains, etc. are inconspicuous on the protective layer. That is, Patent Document 1 discloses an electromagnetic wave shielding film that includes an insulating layer and a shielding layer, and the three-dimensional arithmetic mean surface roughness Sa of the surface of the insulating layer is 0.8 μm or more. Furthermore, Patent Document 2 discloses an electromagnetic wave shielding film that includes an insulating layer and a shielding layer, and the maximum peak height Sp on the surface of the insulating layer is 8.0 μm or more. In addition, when the electromagnetic wave shielding film is attached to a printed wiring board, and the printed wiring board has a base layer, a circuit pattern made of copper foil formed on the base layer, and a cover film for protecting the circuit pattern, due to the reflection of light etc., the circuit pattern of the printed wiring board may appear on the surface of the electromagnetic wave shielding film, and sufficient concealment cannot be obtained. Patent Document 3 discloses an electromagnetic wave shielding film that improves the above-mentioned concealment. That is, Patent Document 3 discloses an electromagnetic wave shielding film which includes an insulating protective layer, a conductive adhesive layer, etc., and the 85° glossiness of the insulating protective layer is less than 15.

[Prior technical literature] [Patent Document] [Patent Document 1] Japanese Patent No. 6783205 [Patent Document 2] Japanese Patent Application Publication No. 2021-010032 [Patent Document 3] Japanese Patent No. 6863908

[Problem to be solved by the invention] Patent Document 1 and Patent Document 2 make the distance from the bottom to the top of the uneven surface of the insulating layer (protective layer) longer so that fingerprints, stains, etc. are inconspicuous on the insulating layer (protective layer). Furthermore, Patent Document 3 increases the surface roughness of the insulating protective layer (protective layer) to which the surface irregularities of the release film are transferred, thereby improving concealment. The tip of the protruding portion of such an insulating layer (protective layer) tends to become thin and fragile. Therefore, if the surface of the insulating layer (protective layer) is impacted, some of the convex portions may be easily broken, and therefore the surface of the insulating layer (protective layer) may be easily damaged. That is, in the inventions described in Patent Document 1, Patent Document 2, and Patent Document 3, there is a problem that the scratch resistance of the surface of the insulating layer (protective layer) is low. In the invention of Patent Document 1, Patent Document 2 or Patent Document 3, it is considered that the method of improving the scratch resistance of the insulating layer (protective layer) is to increase the three-dimensional arithmetic mean surface roughness Sa of the surface of the insulating layer (protective layer). The method is to reduce the maximum peak height Sp of the insulating layer (protective layer) surface, or to reduce the maximum peak height Sp of the insulating layer (protective layer) surface. However, in this case, the concealment of the insulating layer (protective layer) surface will become insufficient. That is, in the inventions of Patent Document 1, Patent Document 2 or Patent Document 3, the concealment and scratch resistance of the surface of the insulating layer (protective layer) are in a trade-off relationship, and it is difficult to achieve both concealment and scratch resistance in these inventions. .

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an electromagnetic wave shielding film that has sufficiently high concealability and scratch resistance on the surface of the protective layer.

[Means used to solve problems] The inventors of this case discovered that on the surface of the protective layer, if the interface development area ratio Sdr or the root mean square slope Sdq is within a predetermined range, both concealment and scratch resistance can be achieved, and the present invention was completed.

That is, the electromagnetic wave shielding film of the present invention is characterized by having a protective layer and a shielding layer. The protective layer has a first main surface and a second main surface opposite to the first main surface. The shielding layer is disposed on the protective layer. The second main surface of the layer; and the interface expansion area ratio Sdr of the above-mentioned first main surface is 75.0~250%.

In the electromagnetic wave shielding film of the present invention, when the interface development area ratio Sdr of the first main surface is 75.0~250%, the distance from the bottom to the top of the concavities and convexities on the first main surface and the density of the concavities and convexes will be within an appropriate range. Therefore, the concealment and scratch resistance of the first main surface of the protective layer will become higher. If the interface expansion area ratio Sdr of the first main surface is less than 75.0%, the concealment will be reduced. If the interface development area ratio Sdr of the first main surface is greater than 250%, the scratch resistance will be reduced.

Furthermore, an electromagnetic wave shielding film according to another aspect of the present invention is characterized by having a protective layer and a shielding layer. The protective layer has a first main surface and a second main surface opposite to the first main surface. The shielding layer It is arranged on the second main surface of the above-mentioned protective layer; and the root mean square slope Sdq of the above-mentioned first main surface is 1.50~2.70.

In the electromagnetic wave shielding film of the present invention, when the root mean square slope Sdq of the first main surface is 1.50~2.70, the distance from the bottom to the top of the unevenness and the density of the unevenness on the first main surface will be within an appropriate range. Therefore, the concealment and scratch resistance of the first main surface of the protective layer will become higher. If the root mean square slope Sdq of the first main surface is less than 1.50, the concealment will be reduced. If the root mean square slope Sdq of the first main surface is greater than 2.70, the scratch resistance is reduced.

In the electromagnetic wave shielding film of the present invention, the minimum autocorrelation length Sal of the first main surface is preferably 2.5~10.0 μm. For an electromagnetic wave shielding film that meets these parameters, the roughness of the first main surface of the protective layer will be moderately fine. Therefore, as for the first main surface of the protective layer, the concealability becomes high and the scratch resistance also becomes high.

In the electromagnetic wave shielding film of the present invention, the arithmetic mean height Sa of the first main surface is preferably 0.3 μm or more and less than 0.8 μm. For an electromagnetic wave shielding film that meets these parameters, the distance from the bottom to the top of the bumps on the first main surface of the protective layer is short. Generally speaking, when the distance from the bottom to the top of the concavities on the first main surface of the protective layer is short, the concealment of the first main surface of the protective layer is likely to be reduced. However, when the interface expansion area ratio Sdr of the first main surface is 75.0~250%, or when the root mean square slope Sdq of the first main surface is 1.50~2.70, the concealment of the first main surface of the protective layer is high enough. .

In the electromagnetic wave shielding film of the present invention, the 60° glossiness of the first main surface is preferably 5.0 or less. Furthermore, in the electromagnetic wave shielding film of the present invention, the 85° glossiness of the first main surface is preferably 60.0 or less. For the electromagnetic wave shielding film of the present invention, if the 60° gloss or the 85° gloss is within the above range, the concealment of the first main surface of the protective layer of the electromagnetic wave shielding film will be sufficiently high.

In the electromagnetic wave shielding film of the present invention, the shielding layer is composed of a metal layer, and a conductive adhesive layer may be disposed on the main surface of the metal layer opposite to the main surface in contact with the protective layer. Furthermore, in the electromagnetic wave shielding film of the present invention, the shielding layer may be composed of a conductive adhesive layer. Regardless of the configuration of the shielding layer, it can be suitable for shielding electromagnetic waves.

The electromagnetic wave shielding film of the present invention is preferably further provided with a matting layer on the first main surface of the protective layer, and a base film is disposed on the main surface of the matting layer opposite to the main surface in contact with the protective layer. When manufacturing the electromagnetic wave shielding film of the present invention, the unevenness formed on the matting layer is transferred to the first main surface of the protective layer to form unevenness on the first main surface of the protective layer. Therefore, by adjusting the unevenness of the matting layer, the interface development area ratio Sdr or the root mean square slope Sdq of the first main surface of the protective layer can be within a predetermined range. In addition, if the base film is disposed on the electromagnetic wave shielding film, the first main surface of the protective layer can be protected from impact or the like. Therefore, when transporting the electromagnetic wave shielding film, the protective layer of the electromagnetic wave shielding film can be prevented from being damaged.

[Effects of the invention] According to the present invention, it is possible to provide an electromagnetic wave shielding film that has sufficiently high concealability and scratch resistance on the surface of the protective layer.

[Form used to implement the invention] Hereinafter, the electromagnetic wave shielding film of the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and can be appropriately modified and applied within the scope of the gist of the present invention.

(First Embodiment) FIG. 1 is a cross-sectional view schematically showing an example of the cross-section of the electromagnetic wave shielding film according to the first embodiment of the present invention. The electromagnetic wave shielding film 1 shown in FIG. 1 includes a protective layer 10 and a shielding layer 20. The protective layer 10 has a first main surface 10a and a second main surface 10b opposite to the first main surface 10a. The shielding layer 20 is disposed on The second main surface 10b of the protective layer 10. In the electromagnetic wave shielding film 1 , the shielding layer 20 is composed of a metal layer, and the conductive adhesive layer 30 is disposed on the main surface of the metal layer opposite to the main surface in contact with the protective layer 10 .

The necessary structural elements of the electromagnetic wave shielding film 1 are that the unevenness 11 is formed on the first main surface 10a of the protective layer 10, and the interface development area ratio Sdr of the surface texture parameter is 75.0 to 250%. In addition, the interface expansion area ratio Sdr of the first main surface 10a is preferably 80.0~170%, and preferably 100~130%. "Interface developed area ratio Sdr" is a numerical value indicating how much the developed area (surface area) of the defined area increases relative to the area of the defined area.

When the interface development area ratio Sdr of the first main surface 10a is 75.0~250%, the distance from the bottom to the top of the bumps 11 of the first main surface 10a and the density of the bumps 11 will be within an appropriate range. Therefore, the concealment and scratch resistance of the first main surface 10a of the protective layer 10 will be improved. If the interface expansion area ratio Sdr of the first main surface is less than 75.0%, the concealment will be reduced. If the interface development area ratio Sdr of the first main surface is greater than 250%, the scratch resistance will be reduced.

In addition, in this specification, the surface properties of the first main surface of the protective layer (the above-mentioned Sdr or the later-described Sdq, Sal, Sa, etc.) are values measured based on ISO 25178-6:2010, and the specific measurement method is explained in the examples.

In the electromagnetic wave shielding film 1, the root mean square slope Sdq of the first main surface 10a of the protective layer 10 is preferably 1.50~2.70, preferably 1.80~2.30, and more preferably 1.90~2.10. "Root mean square slope Sdq" is a parameter calculated from the root mean square of the slope of all points in the defined area. When the root mean square slope Sdq of the first main surface 10a is 1.50~2.70, the distance from the bottom to the top of the concave and convex 11 of the first main surface 10a and the density of the concave and convex 11 will be within an appropriate range. Therefore, the concealment and scratch resistance of the first main surface of the protective layer will become higher. If the root mean square slope Sdq of the first main surface is less than 1.50, the concealment will be reduced. If the root mean square slope Sdq of the first main surface is greater than 2.70, the scratch resistance is reduced.

In the electromagnetic wave shielding film 1, the minimum autocorrelation length Sal of the first main surface 10a of the protective layer 10 is preferably 2.5~10.0 μm, preferably 2.5~6.0 μm, and more preferably 2.5~4.5 μm. "Minimum autocorrelation length Sal" represents the horizontal distance in the direction where the autocorrelation function decays fastest to a specific value s (default is 0.2). In addition, the "minimum autocorrelation length Sal" quantifies the density of the concave and convex shapes in units of length, which means that the smaller the value, the more detailed the texture.

When the minimum autocorrelation length Sal of the first main surface 10a of the protective layer 10 is 2.5~10.0 μm, the fineness of the unevenness 11 of the first main surface 10a of the protective layer 10 will become moderate. Therefore, as for the first main surface 10a of the protective layer 10, the concealability becomes high and the scratch resistance also becomes high.

In the electromagnetic wave shielding film 1, the arithmetic mean height Sa of the first main surface 10a of the protective layer 10 is preferably 0.3 μm or more and less than 0.8 μm, and preferably 0.3 to 0.5 μm. The "arithmetic mean height Sa" is a numerical value indicating the average height (absolute value) calculated from the average plane of the surface having unevenness.

When the arithmetic mean height Sa of the first main surface 10a of the protective layer 10 is 0.3 μm or more and less than 0.8 μm, the distance from the bottom to the top of the unevenness 11 of the first main surface 10a of the protective layer 10 is short. Generally speaking, when the distance from the bottom to the top of the concave and convex 11 of the first main surface 10a of the protective layer 10 is short, the concealment of the first main surface 10a of the protective layer 10 is likely to be reduced. However, in the electromagnetic wave shielding film 1, the interface development area ratio Sdr of the first main surface 10a is 75.0~250%. Therefore, although the arithmetic mean height Sa is within the above range, the concealment of the first main surface 10a of the protective layer 10 is still sufficient. high.

In the electromagnetic wave shielding film 1, the 60° glossiness of the first main surface 10a is preferably 5.0 or less, and preferably 2.0 to 4.0. In addition, in the electromagnetic wave shielding film 1, the 85° glossiness of the first main surface 10a is preferably 60.0 or less, and more preferably 30.0 to 50.0. As for the electromagnetic wave shielding film 1, if the 60° gloss or the 85° gloss is within the above range, the concealment of the first main surface 10a of the protective layer 10 of the electromagnetic wave shielding film 1 will be high enough.

In addition, in this specification, "60° gloss" and "85° gloss" mean the values measured using BYK Gardner micro-gloss (portable gloss meter).

In the electromagnetic wave shielding film 1, the L* value of the first main surface 10a is preferably 30.0 or less, and preferably 26.7 to 28.0. In addition, in this specification, the L* value means the value measured in accordance with JIS Z 8781-4 (2013).

Each structure of the electromagnetic wave shielding film 1 will be described in detail below.

(protective layer) The protective layer 10 is preferably made of a resin material, has insulation properties, and meets predetermined mechanical strength, chemical resistance, and heat resistance.

The resin material constituting the protective layer 10 is not particularly limited as long as it has sufficient insulating properties. For example, thermoplastic resin compositions, thermosetting resin compositions, active energy ray curable compositions, etc. can be used.

The thermoplastic resin composition is not particularly limited, and styrene-based resin compositions, vinyl acetate-based resin compositions, polyester-based resin compositions, polyethylene-based resin compositions, polypropylene-based resin compositions, and imides can be used. resin compositions and acrylic resin compositions, etc. The thermosetting resin composition is not particularly limited, and a phenol-based resin composition, an epoxy-based resin composition, a urethane-based resin composition, a melamine-based resin composition, an alkyd-based resin composition, and the like can be used. The active energy ray curable composition is not particularly limited, and for example, a polymerizable compound having at least two (meth)acryloxy groups in the molecule can be used. One type of these compositions may be used alone, or two or more types may be used in combination.

The protective layer 10 may also contain hardening accelerators, tackifiers, antioxidants, pigments, dyes, plasticizers, ultraviolet absorbers, defoaming agents, leveling agents, fillers, flame retardants, viscosity regulators and Anti-caking agents, etc.

The protective layer 10 has unevenness 11 on the first main surface 10a. The method of forming the concavities and convexities 11 is not particularly limited, and may be formed by, for example, the following method. Method: After forming a matte layer with unevenness on the base film, apply the resin used to form the protective layer 10 on the surface of the matte layer and dry the resin, thereby transferring the unevenness of the matte layer to the protective layer 10 . Method: Apply resin to form a protective layer on the shielding layer (metal layer) 20, press a mold with concavities and convexes on the resin, and then harden the resin to transfer the concavities and convexities of the mold to the protective layer. Method: Add particles for forming unevenness to the protective layer 10 . Method: Sandblast the first main surface 10a of the protective layer 10 to form the concavities and convexities 11 .

A preferred method among the above methods is: after forming a matting layer with concavities and convexities on the base film, coating the resin for forming the protective layer 10 on the surface of the matting layer and drying the resin, thereby transferring the concavities and convexities of the matting layer to the surface of the matting layer. Protective layer 10.

Furthermore, when the unevenness forming particles are added to the protective layer 10 to form the unevenness 11 , for example, resin fine particles or inorganic fine particles can be used as the unevenness forming particles. Examples of the resin particles include acrylic resin particles, polyacrylonitrile particles, polyurethane particles, polyamide particles, polyimide particles, and the like. In addition, as the inorganic fine particles, calcium carbonate fine particles, calcium silicate fine particles, clay, kaolin, talc, silica fine particles, glass fine particles, diatomaceous earth, mica powder, aluminum oxide fine particles, magnesium oxide fine particles, zinc oxide fine particles, and barium sulfate can be used. Microparticles, aluminum sulfate microparticles, calcium sulfate microparticles and magnesium carbonate microparticles, etc. These resin microparticles and inorganic microparticles can be used individually or in combination of several types. From the viewpoint of improving the scratch resistance of the protective layer, inorganic fine particles are preferred.

The thickness of the protective layer 10 is not particularly limited and can be set appropriately as needed. It is preferably 1 to 20 μm, and preferably 4 to 10 μm. If the thickness of the protective layer is less than 1 μm, the strength of the protective layer becomes low, making it difficult to protect the shielding layer (metal layer). If the thickness of the protective layer is greater than 20 μm, the flexibility of the electromagnetic wave shielding film is reduced.

(metal layer) The material of the metal layer is not particularly limited, and nickel, copper, silver, tin, gold, palladium, aluminum, chromium, titanium, zinc and alloys containing two or more of these metals can be used.

In addition, the material and thickness of the metal layer can be appropriately selected depending on the required electromagnetic wave shielding effect and repeated deflection/sliding resistance. For example, from the viewpoint of obtaining a sufficient electromagnetic wave shielding effect, the thickness of the metal layer is preferably 0.1 μm or more. In addition, from the viewpoint of productivity, flexibility, etc., it is preferable to set it to 8 μm or less.

In addition, the metal layer can be formed by electroplating, electroless plating, sputtering, electron beam evaporation, vacuum evaporation, CVD, metal organic vapor deposition, or the like. Moreover, the metal layer can also be formed using metal foil, metal nanoparticles, scaly metal particles, etc.

(Conductive adhesive layer) In the electromagnetic wave shielding film 1, the conductive adhesive layer 30 may have isotropic conductivity or anisotropic conductivity. As will be described later, the conductive adhesive layer 30 will be disposed on the printed wiring board. In this case, if the conductive adhesive layer 30 having either isotropic conductivity or anisotropic conductivity is brought into contact with the ground wiring of the printed wiring board, the printed wiring can be connected via the conductive adhesive layer 30 The ground wiring of the board is electrically connected to the shielding layer (metal layer) 20 of the electromagnetic wave shielding film 1 . Thereby, the electromagnetic wave shielding film 1 can be suitable for shielding electromagnetic waves.

When the conductive adhesive layer 30 has anisotropic conductivity, the transmission characteristics of high-frequency signals transmitted by the printed circuit board through the signal circuit will be further improved than when it has isotropic conductivity.

The conductive adhesive layer 30 contains conductive filler and adhesive resin.

The conductive filler of the conductive adhesive layer 30 is not particularly limited, and may be silver powder, copper powder, nickel powder, solder powder, aluminum powder, silver-coated copper powder obtained by silver-plating copper powder, or metal-coated polymer. Microparticles made of microparticles or glass beads, etc. From an economic point of view, among these, copper powder or silver-coated copper powder that can be obtained at a low price is preferable.

The shape of the conductive filler is not particularly limited, and may be appropriately selected from spherical, flake, scaly, dendritic, rod, fibrous, etc. shapes. Among these, small flakes are preferred. If the conductive filler is a small plate-shaped conductive filler, when the electromagnetic wave shielding film 1 is bent, the conductive filler will also bend, and the contact between the conductive fillers will become easier to maintain. As a result, the conductivity of the conductive adhesive layer becomes difficult to decrease.

The average major diameter of the conductive filler is not particularly limited, but is preferably 0.5 to 15.0 μm, and preferably 5 to 13 μm. If the average major diameter of the conductive filler is 0.5 μm or more, the conductivity of the conductive adhesive layer will be good. If the average major diameter of the conductive filler is 15.0 μm or less, the conductive adhesive layer can be made thinner. In addition, the average major diameter of the conductive filler in this specification means the value measured by the following method. The conductive adhesive layer is cut to obtain a cross section, and a scanning electron microscope (SEM) image of the cross section is obtained. The average long diameter of the conductive filler means the average long diameter of any five conductive fillers in the SEM image.

The weight ratio of the conductive filler contained in the conductive adhesive layer 30 is preferably 10 to 80% by weight. When the conductive adhesive layer 30 has anisotropic conductivity, the weight ratio of the conductive filler contained in the conductive adhesive layer 30 is preferably 10 to 40% by weight, and preferably 15 to 35% by weight.

The thickness of the conductive adhesive layer 30 is not particularly limited and can be appropriately set as needed, and is preferably 0.5~30.0 μm. If the thickness of the conductive adhesive layer is less than 0.5 μm, it will be difficult to obtain good conductivity. If the thickness of the conductive adhesive layer exceeds 30.0 μm, the entire electromagnetic wave shielding film becomes thicker and becomes difficult to handle.

The material of the adhesive resin contained in the conductive adhesive layer 30 is not particularly limited, and styrene-based resin, vinyl acetate-based resin, polyester-based resin, polyethylene-based resin, polypropylene-based resin, and imide-based resin can be used. Thermoplastic resins such as resins, amide resins, and acrylic resins, or thermosetting resins such as phenol resins, epoxy resins, urethane resins, melamine resins, and alkyd resins. The material of the adhesive resin of the conductive adhesive layer 30 may be one of them alone, or may be a combination of two or more.

Next, an electromagnetic wave shielding film according to another aspect of the first embodiment of the present invention will be described. FIG. 2 is a cross-sectional view schematically showing an example of the cross-section of the electromagnetic wave shielding film according to another aspect of the first embodiment of the present invention.

The electromagnetic wave shielding film 101 shown in FIG. 2 includes a protective layer 10 and a shielding layer 120. The protective layer 10 has a first main surface 10a and a second main surface 10b opposite to the first main surface 10a. The shielding layer 120 is disposed on The second main surface 10b of the protective layer 10. Then, the shielding layer 120 is composed of a conductive adhesive layer. In addition, in order for the conductive adhesive layer to function as a shielding layer, it must be an isotropic conductive adhesive layer.

That is, the electromagnetic wave shielding film 101 has the same structure as the above-mentioned electromagnetic wave shielding film 1 except that the metal layer and the conductive adhesive layer are the shielding layer (conductive adhesive layer) 120 .

The electromagnetic wave shielding film according to the first embodiment of the present invention may have a base film on which a matte layer is formed. Use diagrams to illustrate the aspects described.

3 is a cross-sectional view schematically showing an example of a cross-section of an electromagnetic wave shielding film having a matting layer and a base film according to the first embodiment of the present invention. In FIG. 3 , in the electromagnetic wave shielding film 1 described above, a matting layer 40 is further disposed on the first main surface 10 a of the protective layer 10 , and a main surface 40 b on the opposite side of the main surface 40 a of the matting layer 40 that is in contact with the protective layer 10 A base film 50 is provided.

When manufacturing the electromagnetic wave shielding film 1, the unevenness 41 formed on the matting layer 40 is transferred to the first main surface 10a of the protective layer 10, so that the unevenness 11 can be formed on the first main surface 10a of the protective layer 10. Therefore, by adjusting the unevenness 41 of the matting layer 40, the surface properties such as the interface development area ratio Sdr of the first main surface 10a of the protective layer 10 can be made into desired properties. In addition, if the base film 50 is disposed on the electromagnetic wave shielding film 1, the first main surface 10a of the protective layer 10 can be protected from impact or the like. Therefore, when transporting the electromagnetic wave shielding film 1 and the electromagnetic wave shielding film 101, the protective layer 10 can be prevented from being damaged.

In addition, preferred materials for the matting layer 40 and the base film 50 will be described in detail later in the manufacturing method of the electromagnetic wave shielding film according to the first embodiment of the present invention.

In addition, the above-mentioned electromagnetic wave shielding film 101 may have a base film on which a matte layer is formed.

Next, the use of the electromagnetic wave shielding film according to the first embodiment of the present invention will be described. The electromagnetic wave shielding film according to the first embodiment of the present invention is attached to the printed wiring board. The method of attaching the electromagnetic wave shielding film according to the first embodiment of the present invention and the shielding printed wiring board to which the electromagnetic wave shielding film according to the first embodiment of the present invention is attached will be described below using drawings.

4A is a cross-sectional view schematically showing an example of how the electromagnetic wave shielding film according to the first embodiment of the present invention is attached to a printed wiring board. 4B is a cross-sectional view schematically showing an example of a cross-section of a shielded printed wiring board using the electromagnetic wave shielding film according to the first embodiment of the present invention.

As shown in FIG. 4A , the electromagnetic wave shielding film 1 having the base film 50 on which the matting layer 40 is formed is attached with the conductive adhesive layer 30 in contact with the printed wiring board 60 .

The printed wiring board 60 is composed of a base film 61, a printed circuit 62 disposed on the base film 61 and including a ground circuit 62a, and a cover film 63 covering the printed circuit 62. Furthermore, the cover film 63 is formed with an opening 63 a exposing the ground circuit 62 a.

When the electromagnetic wave shielding film 1 is attached to the printed wiring board 60, the conductive adhesive layer 30 of the electromagnetic wave shielding film 1 is embedded in the opening 63a of the cover film 63 and comes into contact with the ground circuit 62a. In this way, the ground circuit 62 a of the printed wiring board 60 can be electrically connected to the conductive adhesive layer 30 and the shielding layer (metal layer) 20 of the electromagnetic wave shielding film 1 . Thereby, the electromagnetic wave shielding film 1 can be suitable for shielding electromagnetic waves.

In the printed wiring board 60, both the base film 61 and the cover film 63 are preferably made of engineering plastic. Examples include resins such as polypropylene, cross-linked polyethylene, polyester, polybenzimidazole, polyimide, polyimide, polyetherimide, and polyphenylene sulfide (PPS).

In the printed wiring board 60, a common circuit material such as copper can be used for the printed circuit 62.

The base film 61 and the printed circuit 62 can be bonded through an adhesive, or can be bonded without using an adhesive in the same manner as a so-called adhesive-less copper-clad laminate. In addition, the cover film 63 may be formed by laminating multiple flexible insulating films through an adhesive, or may be formed through a series of techniques such as coating of photosensitive insulating resin, drying, exposure, development, and heat treatment.

The electromagnetic wave shielding film 1 can be attached to the printed wiring board 60 by a conventionally known method. For example, it is preferable to arrange the electromagnetic wave shielding film 1 on the printed wiring board 60 in such a manner that the conductive adhesive layer 30 of the electromagnetic wave shielding film 1 contacts the cover film 63 of the printed wiring board 60, and then, at 150 to 200°C, 2 Thermocompression bonding is performed under conditions of ~5MPa and 1 to 60 minutes.

Thereafter, as shown in FIG. 4B , the base film 50 on which the matting layer 40 is formed is peeled off from the electromagnetic wave shielding film 1 to form the shielding printed wiring board 70 .

Next, a method of manufacturing the electromagnetic wave shielding film 1 will be described. The manufacturing method of the electromagnetic wave shielding film 1 includes (1) a matting layer forming step, (2) a protective layer forming step, (3) a metal layer forming step, and (4) a conductive adhesive layer forming step. Each step is detailed below.

(1) Matting layer formation step FIG. 5 is a step diagram schematically showing an example of a matting layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. When manufacturing the electromagnetic wave shielding film of the present invention, as shown in FIG. 5 , a base film 50 is prepared. Then, a resin composition containing particles for forming unevenness is applied to the main surface of the base film 50 and dried, thereby forming the matte layer 40 having the unevenness 41 .

The material of the base film 50 is not particularly limited, and may include: polyethylene terephthalate, polyethylene naphthalate, polyvinyl fluoride, polyvinylidene fluoride, rigid polyvinyl chloride, polydichloroethylene Ethylene, nylon, polyimide, polystyrene, polyvinyl alcohol, ethylene/vinyl alcohol copolymer, polycarbonate, polyacrylonitrile, polybutylene, soft polyvinyl chloride, polyvinylidene fluoride, polyethylene, Polypropylene, polyurethane, ethylene vinyl acetate copolymer, polyvinyl acetate and other plastic sheets; translucent paper (glassine paper), Dowling paper, kraft paper, coated paper and other paper types; various non-woven fabrics, synthetic Paper, metal foil or composite films composed of these.

The uneven-forming particles constituting the matting layer 40 are not particularly limited, and resin fine particles or inorganic fine particles can be used. Examples of the resin particles include acrylic resin particles, polyacrylonitrile particles, polyurethane particles, polyamide particles, and polyimide particles. In addition, as the inorganic fine particles, calcium carbonate fine particles, calcium silicate fine particles, clay, kaolin, talc, silica fine particles, glass fine particles, diatomaceous earth, mica powder, aluminum oxide fine particles, magnesium oxide fine particles, zinc oxide fine particles, and barium sulfate can be used. Microparticles, aluminum sulfate microparticles, calcium sulfate microparticles, magnesium carbonate microparticles, etc. These resin microparticles and inorganic microparticles can be used individually or in combination of several types.

The resin component constituting the matting layer 40 is not particularly limited, and polyester resin compositions, acrylic resin compositions, phenol resin compositions, epoxy resin compositions, urethane resin compositions, Polysilicone resin compositions, melamine resin compositions, alkyd resin compositions, etc.

Regarding the properties of the unevenness 41 of the matte layer 40, desired properties can be achieved by adjusting the type, size, and usage amount of the unevenness-forming particles used, or the type of resin component.

(2) Protective layer formation step 6 is a step diagram schematically showing an example of a protective layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. Next, as shown in FIG. 6 , the protective layer 10 is formed on the main surface of the matting layer 40 on which the unevenness 41 is formed. Thereby, the unevenness 41 of the matting layer 40 will be transferred to the protective layer 10 to form the unevenness 11 of the protective layer 10 . The protective layer 10 can be formed by a conventionally known method.

(3) Metal layer formation step 7 is a step diagram schematically showing an example of a metal layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. Next, as shown in FIG. 7 , a shield layer (metal layer) 20 is formed on the second main surface 10 b of the protective layer 10 . The method of forming the metal layer is not particularly limited. A metal foil having a predetermined thickness can be bonded to the protective layer 10 , or a metal layer can be formed on the surface of the protective layer 10 by evaporation or plating.

(4) Conductive adhesive layer formation step 8 is a step diagram schematically showing an example of a conductive adhesive layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. Next, as shown in FIG. 7 , the conductive adhesive layer 30 is formed on the shield layer (metal layer) 20 . The method of forming the conductive adhesive layer 30 is not particularly limited, and may be performed by applying a conductive adhesive layer composition containing the material constituting the conductive adhesive layer 30 . The coating method is a conventionally well-known coating method, and examples thereof include gravure coating, kiss coat, die coating, lip coating, comma coat, and knife coating. (blade coat) method, roller coating method, knife coat method, spray coating method, rod coating method, spin coating method, dip coating method, etc.

Through the above steps, the electromagnetic wave shielding film 1 can be manufactured. In addition, if the electromagnetic wave shielding film 1 of FIG. 8 is rotated 180°, it will be the electromagnetic wave shielding film 1 having the base film 50 formed with the matting layer 40 as shown in FIG. 3 .

In addition, when manufacturing the above-mentioned electromagnetic wave shielding film 101, the "(3) Metal layer forming step" may not be performed, but in the "(4) Conductive adhesive layer forming step", a layer of The electromagnetic wave shielding film 101 is manufactured by using a conductive adhesive layer with isotropic conductivity.

Moreover, in the above-mentioned "(1) matting layer forming step", the matting layer 40 is formed by coating the base film 50 with a resin composition containing particles for forming unevenness. In this case, the base film 50 can be embossed to form a part of the base film 50 into the matte layer 40 , or a part of the base film 50 can be made into the matt layer 40 by sandblasting the base film 50 . In addition, by adjusting the conditions of embossing and sandblasting, the shape of the concavities and convexities 41 of the matte layer 40 can be controlled.

(Second Embodiment) The necessary components of the electromagnetic wave shielding film according to the second embodiment of the present invention are that the interface development area ratio Sdr of the first main surface is changed to 75.0~250%, and the root mean square slope Sdq of the first main surface is 1.50~2.70. Except for this, the rest of the structure is the same as that of the electromagnetic wave shielding film of the first embodiment of the present invention.

In the electromagnetic wave shielding film according to the second embodiment of the present invention, the root mean square slope Sdq of the first main surface is preferably 1.80 to 2.30, more preferably 1.90 to 2.10.

Furthermore, in the electromagnetic wave shielding film according to the second embodiment of the present invention, the interface development area ratio Sdr of the first main surface is preferably 75.0 to 250%, more preferably 80.0 to 170%, and more preferably 100 to 130%.

Regarding features other than those described above, the suitable structure of the electromagnetic wave shielding film according to the second embodiment of the present invention is the same as the suitable structure of the electromagnetic wave shielding film according to the first embodiment of the present invention.

(Other embodiments) Regarding the electromagnetic wave shielding film of the present invention, when the shielding layer is composed of a metal layer, a non-conductive adhesive may be disposed on the main surface of the metal layer opposite to the main surface in contact with the protective layer. layer. In such an aspect, the electromagnetic wave shielding film of the present invention can fully shield electromagnetic waves through the metal layer. The material of the non-conductive adhesive layer is not particularly limited, and styrene-based resins, vinyl acetate-based resins, polyester-based resins, polyethylene-based resins, polypropylene-based resins, amide-based resins, and amide-based resins can be used. resin, thermoplastic resin such as acrylic resin, or thermosetting resin such as phenol resin, epoxy resin, urethane resin, melamine resin, alkyd resin, etc.

[Example] The following shows embodiments that illustrate the present invention in more detail, but the present invention is not limited to these embodiments.

(Example 1) ~ (Example 11) and (Comparative Example 1) ~ (Comparative Example 5) In the following manufacturing methods of electromagnetic wave shielding films, in each of the examples and comparative examples, except for "(1) Matting layer formation step", other steps are common.

(1) Matting layer formation step Prepare a polyethylene terephthalate film as the base film. Next, an epoxy resin containing particles for forming uneven surfaces was applied to the main surface of the polyethylene terephthalate film so that the thickness became 4.0 μm, thereby forming a matte layer having uneven surfaces. At this time, in order to make the surface properties of the first main surface of the protective layer of the electromagnetic wave shielding films of the manufactured Examples and Comparative Examples reach the values shown in Table 1, the type, size, and usage amount of the particles for forming the unevenness were adjusted. .

(2) Protective layer formation step Next, apply epoxy resin on the matting layer and heat it in an electric oven at 100°C for 2 minutes to create a protective layer with a thickness of 5 μm. Thereby, the unevenness of the matting layer is transferred to the first main surface of the protective layer.

(3) Metal layer formation step Afterwards, a 2 μm copper layer was formed on the protective layer by electroless plating. This copper layer will act as a shield.

(4) Conductive adhesive layer formation step Next, 100 parts by mass of bisphenol A-type epoxy resin, 0.1 part by mass of hardener (ST14 manufactured by Mitsubishi Chemical Co., Ltd.), and dendritic silver-coated copper powder were added to toluene so that the solid content became 20% by mass. (average particle diameter: 13 μm), and stirred and mixed to prepare a composition for a conductive adhesive layer. The obtained composition for conductive adhesive layer was applied to the copper layer to form a conductive adhesive layer with a thickness of 15 μm.

Through the above steps, the electromagnetic wave shielding films of each embodiment and each comparative example were manufactured.

[Evaluation of electromagnetic wave shielding film] A polyimide film with a thickness of 25 μm was prepared as a model of the member to be adhered, and the electromagnetic wave shielding film of each example and each comparative example was arranged by contacting the conductive adhesive layer with the polyimide film, using a press and heating at 170°C , 3 minutes, heating and pressing under the conditions of 2.0MPa, and further heating at 150°C for 1 hour for bonding. After that, the base film on which the matting layer was formed was peeled off, and the properties of the first main surface of the protective layer of the electromagnetic wave shielding films of each example and each comparative example were measured and evaluated as follows.

[Measurement of surface properties of protective layer] Using a conjugate focus microscope (OPTELICS HYBRID, manufactured by Lasertec Corporation, with an objective lens of 100 times), five arbitrary points on the surface of the protective layer of the electromagnetic wave shielding film of each example and each comparative example were measured, and then data analysis software (LMeye7) was used. Correction of surface inclination and determination of surface properties in accordance with ISO 25178-6:2010. In addition, the cut-off wavelength of the S filter is set to 0.0025 mm, and the cut-off wavelength of the L filter is set to 0.8 mm. The results are shown in Table 1.

[Measurement of Glossiness] BYK Gardner micro-gloss (portable gloss meter) was used to measure the 60° gloss and the 85° gloss of the protective layer surface of the electromagnetic wave shielding films of each example and each comparative example. The results are shown in Table 1.

[Measurement of L* value] The L* value of the protective layer surface of the electromagnetic wave shielding film of each example and each comparative example was measured using an integrating sphere spectrophotometer (made by X-Rite, Ci64, tungsten light source). In addition, a* value and b* value were also measured.

[Evaluation of scratch resistance] Use your fingernail to scratch the protective layer of the electromagnetic wave shielding film of each example and each comparative example with a load of 0.5~0.8N. After that, the protective layer of the electromagnetic wave shielding film of each example and each comparative example was visually inspected, and the scratch resistance was evaluated on a scale of 1 to 6. Additionally, in this review, higher scores mean greater scratch resistance. The evaluation results are shown in Table 1. The scoring criteria are shown in Figures 9A to 9F. FIG. 9A is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 6 in the scratch resistance evaluation. FIG. 9B is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 5 in the scratch resistance evaluation. FIG. 9C is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 4 in the scratch resistance evaluation. FIG. 9D is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 3 in the scratch resistance evaluation. FIG. 9E is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 2 in the scratch resistance evaluation. FIG. 9F is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 1 in the scratch resistance evaluation.

[Evaluation of concealment] The first main surface of the protective layer of the electromagnetic wave shielding film of each example and each comparative example was visually inspected, and the concealment was visually determined. Specifically, a press is used to join the printed wiring board and the electromagnetic wave shielding film under conditions of temperature: 170°C, time: 3 minutes, and pressure: 2~3MPa to produce a shielding wiring substrate; the above-mentioned printed wiring board has a base layer, a circuit pattern composed of copper foil (line width 0.1 mm, height 12 μm) provided on the base layer, and a polyethylene layer covering the circuit pattern and adhered to the base layer through an adhesive layer (thickness 25 μm) Imine film (thickness 12.5μm). Place the shielded wiring board on a flat table, and evaluate whether the circuit pattern can be seen from the electromagnetic wave shielding film side in an environment where the illumination on the surface of the shielding wiring board is 800 to 1000 lux. The viewing angle is set in the range of 0~180° for the electromagnetic wave shielding film surface. The results are shown in Table 1. In addition, the judgment criteria are as follows. FIG. 10A is a photograph of the first main surface of the protective layer of the electromagnetic wave shielding film, which is the criterion of "excellent (◎)" in the concealment judgment of the first main surface of the protective layer of the electromagnetic wave shielding film. 10B is a photograph of the surface of the protective layer that is the criterion of "good (0)" in the concealment judgment of the first main surface of the protective layer of the electromagnetic wave shielding film. FIG. 10C is a photograph of the first main surface of the protective layer of the electromagnetic wave shielding film, which is the criterion of "acceptable (△)" in the concealment judgment of the first main surface of the protective layer of the electromagnetic wave shielding film. Excellent (◎): As shown in Figure 10A, the glossiness of the first main surface of the protective layer is sufficiently suppressed and the circuit pattern of the printed wiring board cannot be distinguished. Good (0): As shown in FIG. 10B , the glossiness of the first main surface of the protective layer is suppressed to a certain extent, making it almost impossible to identify the circuit pattern of the printed wiring board. Yes (△): As shown in Figure 10C, the gloss of the first main surface of the protective layer cannot be suppressed, and it is difficult to call it matting. The circuit pattern of the printed wiring board can be identified.

[Table 1]

As shown in Table 1, it can be seen that when the interface expansion area ratio Sdr of the first main surface of the protective layer of the electromagnetic wave shielding film is 75.0~250%, and the root mean square slope Sdq is 1.50~2.70, the concealment and scratch resistance are better. Both sexes are high. In addition, it can be seen that when the interface development area ratio Sdr is less than 75.0%, or when the root mean square slope Sdq is less than 1.50, the concealment becomes low. In addition, it can be seen that when the interface development area ratio Sdr is greater than 250% or the root mean square slope Sdq is greater than 2.70, the scratch resistance becomes low.

This manual describes the following matters.

The present disclosure (1) is an electromagnetic wave shielding film, which is characterized by having a protective layer and a shielding layer. The protective layer has a first main surface and a second main surface opposite to the first main surface. The shielding layer is arranged on the above-mentioned The second main surface of the protective layer, and the interface expansion area ratio Sdr of the above-mentioned first main surface is 75.0~250%.

The present disclosure (2) is an electromagnetic wave shielding film, which is characterized by having a protective layer and a shielding layer. The protective layer has a first main surface and a second main surface opposite to the first main surface. The shielding layer is arranged on the above-mentioned The second main surface of the protective layer, and the root mean square slope Sdq of the first main surface is 1.50~2.70.

The disclosure (3) is an electromagnetic wave shielding film according to the disclosure (1) or (2), wherein the minimum autocorrelation length Sal of the above-mentioned first main surface is 2.5~10.0 μm.

The present disclosure (4) is the electromagnetic wave shielding film according to any one of the present disclosures (1) to (3), wherein the arithmetic mean height Sa of the first main surface is 0.3 μm or more and less than 0.8 μm.

The present disclosure (5) is the electromagnetic wave shielding film according to any one of the present disclosures (1) to (4), wherein the 60° glossiness of the first main surface is 5.0 or less.

The present disclosure (6) is the electromagnetic wave shielding film according to any one of the present disclosures (1) to (5), wherein the 85° glossiness of the first main surface is 60.0 or less.

The present disclosure (7) is an electromagnetic wave shielding film according to any one of the disclosures (1) to (6), wherein the shielding layer is composed of a metal layer, and the main surface of the metal layer that is in contact with the protective layer A conductive adhesive layer is arranged on the opposite main surface.

The present disclosure (8) is the electromagnetic wave shielding film according to any one of the present disclosures (1) to (6), wherein the above-mentioned shielding layer is composed of a conductive adhesive layer.

The present disclosure (9) is the electromagnetic wave shielding film according to any one of the present disclosures (1) to (8), wherein a matting layer is further disposed on the first main surface of the above-mentioned protective layer, and between the above-mentioned matting layer and the above-mentioned protective layer A base film is arranged on the main surface opposite to the main surface where the layers are in contact.

1,101:Electromagnetic wave shielding film 10:Protective layer 10a: The first main surface of the protective layer 10b: The second main surface of the protective layer 11: The unevenness of the protective layer 20,120:shielding layer 30: Conductive adhesive layer 40:Matting layer 40a, 40b: Main surface of matting layer 41: The unevenness of the matte layer 50:Substrate film 60:Printed wiring board 61: basement membrane 62:Printed circuit 62a: Ground circuit 63: Covering film 63a: opening 70: Shielded printed wiring board

FIG. 1 is a cross-sectional view schematically showing an example of the cross-section of the electromagnetic wave shielding film according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of the cross-section of the electromagnetic wave shielding film according to another aspect of the first embodiment of the present invention. 3 is a cross-sectional view schematically showing an example of the cross-section of the electromagnetic wave shielding film having a matting layer and a base film according to the first embodiment of the present invention. 4A is a cross-sectional view schematically showing an example of how the electromagnetic wave shielding film according to the first embodiment of the present invention is attached to a printed wiring board. 4B is a cross-sectional view schematically showing an example of a cross-section of a shielded printed wiring board using the electromagnetic wave shielding film according to the first embodiment of the present invention. FIG. 5 is a step diagram schematically showing an example of a matting layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. 6 is a step diagram schematically showing an example of a protective layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. 7 is a step diagram schematically showing an example of a metal layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. 8 is a step diagram schematically showing an example of a conductive adhesive layer forming step in the method for manufacturing an electromagnetic wave shielding film according to the first embodiment of the present invention. FIG. 9A is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 6 in the scratch resistance evaluation. FIG. 9B is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 5 in the scratch resistance evaluation. FIG. 9C is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 4 in the scratch resistance evaluation. FIG. 9D is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 3 in the scratch resistance evaluation. FIG. 9E is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 2 in the scratch resistance evaluation. FIG. 9F is a photograph showing the surface state of the protective layer of the electromagnetic wave shielding film that is the basis for a score of 1 in the scratch resistance evaluation. FIG. 10A is a photograph of the first main surface of the protective layer of the electromagnetic wave shielding film, which is the criterion of "excellent (◎)" in the concealment judgment of the first main surface of the protective layer of the electromagnetic wave shielding film. 10B is a photograph of the surface of the protective layer that is the criterion of "good (0)" in the concealment judgment of the first main surface of the protective layer of the electromagnetic wave shielding film. FIG. 10C is a photograph of the first main surface of the protective layer of the electromagnetic wave shielding film, which is the criterion of "acceptable (△)" in the concealment judgment of the first main surface of the protective layer of the electromagnetic wave shielding film.

1: Electromagnetic wave shielding film

10:Protective layer

10a: The first main surface of the protective layer

10b: The second main surface of the protective layer

11: The unevenness of the protective layer

20:Shielding layer

30: Conductive adhesive layer

Claims (9)

An electromagnetic wave shielding film characterized by having a protective layer and a shielding layer, The aforementioned protective layer has a first main surface and a second main surface opposite to the aforementioned first main surface, The aforementioned shielding layer is arranged on the second main surface of the aforementioned protective layer, and The interface expansion area ratio Sdr of the first main surface is 75.0~250%. An electromagnetic wave shielding film characterized by having a protective layer and a shielding layer, The aforementioned protective layer has a first main surface and a second main surface opposite to the aforementioned first main surface, The aforementioned shielding layer is arranged on the second main surface of the aforementioned protective layer, and The root mean square slope Sdq of the first main surface is 1.50~2.70. For example, the electromagnetic wave shielding film of claim 1 or 2, wherein the minimum autocorrelation length Sal of the first main surface is 2.5~10.0 μm. The electromagnetic wave shielding film of claim 1 or 2, wherein the arithmetic mean height Sa of the first main surface is 0.3 μm or more and less than 0.8 μm. The electromagnetic wave shielding film of claim 1 or 2, wherein the 60° glossiness of the first main surface is 5.0 or less. The electromagnetic wave shielding film of claim 1 or 2, wherein the 85° glossiness of the first main surface is 60.0 or less. The electromagnetic wave shielding film of claim 1 or 2, wherein the aforementioned shielding layer is composed of a metal layer, and A conductive adhesive layer is disposed on the main surface of the metal layer opposite to the main surface in contact with the protective layer. The electromagnetic wave shielding film of claim 1 or 2, wherein the shielding layer is composed of a conductive adhesive layer. The electromagnetic wave shielding film of claim 1 or 2, wherein a matting layer is further disposed on the first main surface in front of the protective layer, and a base is disposed on the main surface opposite to the main surface of the matting layer that is in contact with the protective layer. Material film.

Images