TWI700982B - Electromagnetic wave shielding film - Google Patents

Abstract

The present invention relates to an electromagnetic wave shielding film. The electromagnetic wave shielding film includes an insulating protective layer 110 and a shielding layer 120. The arithmetic average inclination of the surface of the insulating protection layer 110 is above 30°.

Description

Electromagnetic wave shielding film

The present invention relates to an electromagnetic wave shielding film.

In recent years, there has been an increasing demand for smart phones and tablet information terminals with high-speed transmission of large-capacity data. To transmit large-capacity data at high speeds, high-frequency signals are required. However, if a high-frequency signal is used, the signal circuit set on the printed wiring board will emit electromagnetic noise, which can easily cause malfunction of peripheral equipment. In order to prevent the above malfunctions, it is important to shield the electromagnetic waves and prevent the printed wiring board from interference.

In order to shield the electromagnetic wave and prevent the printed wiring board from interference, a method has been proposed in which an electromagnetic wave shielding film including an insulating layer and a shielding layer is attached to the printed wiring board (for example, refer to Patent Document 1).

In addition, in order to hide the circuit pattern, someone has proposed an electromagnetic wave shielding film in which an insulating protective layer is dyed in black (for example, refer to Patent Document 2).

In addition, in order to improve the visual clarity of the white characters printed on the surface of the electromagnetic wave shielding film, it has been proposed to adjust the color tone of the insulating protective layer of the electromagnetic wave shielding film (for example, refer to Patent Document 3).

〔Patent Literature〕

[Patent Document 1] JP 2004-095566 A

[Patent Document 2] JP 2014-078574 A

[Patent Document 3] Japanese Patent No. 5796690

In the assembly process of electronic devices, in order to manage the printed wiring board, white ink is used to print symbols and the like on the surface of the electromagnetic wave shielding film pasted on the printed wiring board. However, the conventional electromagnetic wave shielding film has the following disadvantages: it is easy to bleed when printed with white ink, resulting in low productivity in the process of printing with white ink.

In addition, there is a demand for light weight and miniaturization in information terminals equipped with electromagnetic wave shielding films. Therefore, with this demand, the size of electromagnetic wave shielding films has become smaller and smaller, and the characters printed on electromagnetic wave shielding films have also increased. small.

The printed characters become smaller, making the characters printed on the previous electromagnetic wave shielding film difficult to read. Especially in a higher illuminance room, the influence will become greater.

Also, if you use screen printing to print text and symbols on the previous electromagnetic wave shielding film, the following problems will occur: ink will bleed between the screen printing plate and the electromagnetic wave shielding film, resulting in a decrease in printing accuracy and smaller characters. Illegible. Even if the color tone of the insulating protective layer is adjusted and the contrast ratio is increased, it is difficult to fundamentally improve the problem of reduced visual clarity caused by color bleeding.

The purpose of the present invention is to realize an electromagnetic wave shielding film that can not only make small characters and the like easy to recognize, but also can print on the surface with high precision.

One aspect of the electromagnetic wave shielding film is to include an insulating protective layer and a shielding layer, and the arithmetic mean slope of the surface of the insulating protective layer is above 30°.

According to the electromagnetic wave shielding film of the present invention, small characters and the like can be easily recognized, and high-precision printing can be performed.

110‧‧‧Insulation protection layer

120‧‧‧Shielding layer

130‧‧‧Adhesive layer

140‧‧‧Isotropic conductive adhesive layer

Fig. 1 is a cross-sectional view showing an electromagnetic wave shielding film according to an embodiment.

Fig. 2 is a cross-sectional view showing an electromagnetic wave shielding film according to a modification.

The electromagnetic wave shielding film of the present invention will be specifically described below. However, the present invention is not limited to the following embodiments, and can be applied with appropriate changes within the scope not changing the gist of the present invention.

(Electromagnetic wave shielding film)

FIG. 1 is a schematic cross-sectional view schematically showing the electromagnetic wave shielding film of this embodiment. As shown in FIG. 1, the electromagnetic wave shielding film includes an insulating protective layer 110 and a shielding layer 120. On the surface of the shielding layer 120 opposite to the insulating protective layer 110, an adhesive layer 130 may be provided as required. By providing the adhesive layer, the electromagnetic wave shielding film can be easily attached to the printed wiring board.

(Insulation protection layer)

The insulating protective layer 110 is provided to protect the shielding layer. In the electromagnetic shielding film of this embodiment, the arithmetic mean gradient of the insulating protective layer 110 is 30° or more.

By setting the arithmetic mean inclination of the insulating protective layer 110 above 30° (it is better to set it above 35°, preferably above 40°), the surface area of the insulating protective layer 110 will increase, and the ink absorption will be improved. It will increase, so that it is possible to suppress ink bleeding during screen printing. In this way, the efficiency of printing operations can be improved.

From the viewpoint of reducing bleeding, the value of the arithmetic mean gradient is preferably larger. From the viewpoint of productivity of the insulating protective layer 110, the arithmetic mean gradient is preferably 80° or less, and more preferably 70° or less.

It should be noted that the arithmetic mean gradient of the present invention can be measured in accordance with JIS B 0601 (2001).

The Root mean square slope of the insulating protection layer can be above 35°, preferably above 40°, especially above 45°. Because the root mean square dip The inclination is more than 35°, so the surface area of the insulating protective layer 110 will be larger, the ink absorbency will be improved, and the ink bleeding during screen printing can be suppressed. In this way, the efficiency of printing operations can be improved.

It should be noted that the root mean square slope in the present invention can be measured in accordance with JIS B 0601 (2001).

The method of forming an insulating protective layer having a predetermined range of arithmetic mean gradient and root mean square gradient is not particularly limited, and a known method can be used. Such well-known methods include, for example, embossing to give the release film an uneven shape, coating the surface of the release film with a resin composition forming an insulating protective layer and drying, thereby printing the uneven shape of the release film onto the insulating protective layer The method; the method of coating the resin composition containing fine particles on the surface of the shielding layer and drying to form an insulating protective layer with uneven shapes; the method of spraying dry ice on the surface of the insulating protective layer; coating the surface of the shielding layer to cure with active energy rays After molding the composition, press a mold having a concave and convex shape to the surface of the shielding layer to solidify the curable composition layer and peel off the mold.

Among the above methods, from the viewpoint of productivity, a preferred method is a method of coating a resin composition containing fine particles and drying to form an insulating protective layer having a concave-convex shape. At this time, the fine particles added to the insulating protective layer 110 are not particularly limited. For example, resin fine particles or inorganic fine particles can be used. As the resin particles, acrylic resin particles, polyacrylonitrile particles, polyurethane particles, polyamide particles, polyimide particles, and the like can be used. Inorganic particles can use calcium carbonate particles, calcium silicate particles, clay, kaolin, talc, silica particles, glass particles, diatomaceous earth, mica powder, alumina particles, magnesium oxide particles, zinc oxide particles, barium sulfate particles, Aluminum sulfate particles, calcium sulfate particles, magnesium carbonate particles, etc. The above-mentioned resin fine particles and inorganic fine particles can be used alone or in combination of plural kinds. From the viewpoint of improving the abrasion resistance of the insulating protective layer, inorganic fine particles are preferred.

From the viewpoint of making the surface of the insulating protective layer moderately uneven and increasing the arithmetic average gradient and root mean square gradient, the 50% average particle size of the particles is preferably 2μm or more, more preferably 4μm or more, and 10μm or more Especially good. In order to suppress the whitening of the insulating protective layer, the 50% average particle size is preferably 30 μm or less, and more preferably 20 μm or less.

From the viewpoint of making the arithmetic mean gradient and the root mean square gradient larger, the amount of particles added to the insulating protective layer 110 is preferably 3% by mass or more, and more preferably 5% or more. From the viewpoint of suppressing whitening of the insulating protective layer, the amount of particles added to the insulating protective layer 110 is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 17% by mass or less.

A black colorant can be added to the insulating protective layer 110. By adding a black colorant, the L* value of the insulating protective layer 110 can be reduced, thereby further improving the visual clarity of characters. When the text printed on the insulating protective layer 110 is white, it is better to let the L* value be less than 20, and more preferably less than 18. It should be noted that the L* value in the present invention can be measured in accordance with JIS Z 8781-4 (2013).

The black colorant may be a black pigment or a mixed pigment obtained by subtractively mixing a plurality of pigments to become black. The black pigment can be, for example, any one or a combination of the following: carbon black, Ketjen Black, carbon nanotube (CNT), Perylene Black, titanium black, iron black, aniline black, etc. . As the mixed pigment, for example, pigments such as red, green, blue, yellow, purple, cyan (Cyan), and magenta (Magenta) can be mixed.

The particle size of the black colorant may be as long as it can achieve the desired L* value, but from the viewpoints of dispersibility and reduction of the L* value, the average primary particle size is preferably 20 nm or more and 100 nm or less. The average primary particle size of the black colorant can be obtained from the average particle size of about 20 primary particles that can be observed on an image magnified by a transmission electron microscope (TEM) of about 50,000 times to about 1 million times.

From the viewpoint of making the L* value small, the amount of the black colorant added to the insulating protective layer 110 is preferably 0.5% by mass or more, and more preferably 1% by mass or more. However, the black-based coloring agent may be added as needed, and it may not be added.

Let the 60° gloss of the insulating protective layer 110 be 3% or less (below 2%, better than 1%), so that moderate light scattering will occur on the surface of the insulating protective layer 110, and the gloss will be improved. Will be moderately suppressed. In this way, the visual clarity of printed text can be improved. The 85° gloss of the insulating protective layer 110 is preferably 10% or less, more preferably 3% or less, and particularly preferably 1% or less.

It should be noted that the 60° gloss and 85° gloss in the present invention can be measured according to the method shown in the examples.

The insulating protective layer 110 preferably has the required insulation and meets the required mechanical strength, chemical resistance and heat resistance.

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

The thermoplastic resin composition is not particularly limited. A styrene resin composition, a vinyl acetate resin composition, a polyester resin composition, a polyethylene resin composition, a polypropylene resin composition, and an imide resin composition can be used. Resin composition, acrylic resin composition, etc. The thermosetting resin composition is not particularly limited, and a phenol resin composition, epoxy resin composition, urethane resin composition, melamine resin composition, alkyd resin composition, etc. can be used. The active energy ray-curable composition is not particularly limited. For example, a polymerizable compound containing at least two (meth)acryloyloxy groups in the molecule can be used. The above-mentioned composition may be used alone or in combination of two or more.

In the insulating protective layer 110, in addition to the above-mentioned particles and colorants, it can also According to needs, it contains curing accelerators, tackifiers, antioxidants, pigments, dyes, plasticizers, ultraviolet absorbers, defoamers, levelers, fillers, flame retardants, viscosity regulators, anti-adhesion (anti- blocking agent etc.

The thickness of the insulating protective layer 110 is not particularly limited and can be appropriately set as required. However, from the viewpoint of adequately protecting the shielding layer, the thickness of the insulating protective layer 110 is preferably 1 μm or more, and more preferably 4 μm or more. From the viewpoint of ensuring the flexibility of the electromagnetic wave shielding film, the thickness of the insulating protective layer 110 is preferably 10 μm or less, and more preferably 5 μm or less.

(Shield)

The shielding layer 120 of this embodiment may be a metal layer. The shielding layer 120 may use a metal layer formed of any one of the following metals or alloys including two or more of the following: nickel, copper, silver, tin, gold, palladium, aluminum, chromium, titanium, zinc. The material and thickness of the metal layer can be appropriately selected according to the required electromagnetic shielding effect and resistance to repeated bending and sliding wear. From the viewpoint of obtaining a sufficient electromagnetic shielding effect, the thickness of the metal layer is preferably 0.1 μm or more. From the viewpoints of productivity and flexibility, the thickness of the metal layer is preferably 8 μm or less. It should be noted that the metal layer can be formed by electroplating, electroless plating, sputtering, electron beam evaporation, vacuum evaporation, CVD, organometallic chemical vapor deposition, or the like. The metal layer can be formed of metal foil, metal nanoparticles, scaly metal particles, or the like.

(Adhesive layer)

The electromagnetic wave shielding film of this embodiment may have an adhesive layer 130 on the side of the shielding layer 120 opposite to the insulating protective layer 110. The adhesive layer 130 can be formed of a resin composition having adhesiveness. The adhesive resin composition is not particularly limited, and it can be used: styrene resin composition, vinyl acetate resin composition, polyester resin composition, polyethylene resin composition, polypropylene resin composition, and Amine resin composition, amide resin composition, acrylic resin Thermoplastic resin composition such as composition; thermosetting resin composition such as phenol resin composition, epoxy resin composition, urethane resin composition, melamine resin composition, alkyd resin composition, etc. . The above-mentioned composition may be used alone or in combination of two or more.

The adhesive layer 130 can be formed as a layer having isotropic conductivity or anisotropic conductivity as required. If the adhesive layer 130 is formed as a conductive layer, it is only necessary to add conductive fine particles to the adhesive resin composition.

The conductive fine particles are not particularly limited, and metal fine particles, carbon nanotubes, carbon fibers, metal fibers, etc. can be used. For example, metal particles such as silver powder, copper powder, nickel powder, solder powder, and aluminum powder can be used. It is also possible to use silver-coated copper powder formed by plating copper powder with silver, metal-coated particles formed by coating polymer particles or glass beads with metal, and the like. Among them, from the viewpoint of economics, copper powder or silver-coated copper powder that can be obtained at a low price is preferable.

The 50% average particle size of the conductive particles is not particularly limited, but from the viewpoint of achieving good conductivity, the 50% average particle size of the conductive particles is preferably 0.5 μm or more. From the viewpoint of making the conductive adhesive layer thinner, the 50% average particle diameter of the conductive particles is preferably 15 μm or less.

The shape of the conductive particles is not particularly limited, and can be appropriately selected from shapes such as spherical, flat, scaly, and dendritic.

The thickness of the adhesive layer 130 can be adjusted as needed. From the viewpoint of achieving good adhesiveness, the thickness of the adhesive layer 130 is preferably 0.5 μm or more. From the viewpoint of making the electromagnetic wave shielding film thin, the thickness of the adhesive layer 130 is preferably 20 μm or less.

The electromagnetic wave shielding film has the insulating protective layer 110, the shielding layer 120, and the adhesive layer 130 as described above. However, as shown in FIG. 2, it is also possible to use The composition of the insulating protective layer 110 and the isotropic conductive adhesive layer 140.

The insulating protective layer 110 can have the same configuration as the electromagnetic wave shielding film shown in FIG. 1. The isotropic conductive adhesive layer 140 may be formed of the same adhesive resin composition and conductive particles as the adhesive layer 130. The isotropic conductive adhesive layer 140 functions as a shielding layer.

(Method of manufacturing shielding film)

The electromagnetic wave shielding film can be manufactured by a known manufacturing method. One example is shown below.

First, a conductive adhesive layer 130 is formed on the base film whose surface has undergone a mold release treatment. Specifically, a solution of the adhesive layer composition containing the material constituting the adhesive layer 130 is applied to the surface of the base film and dried, thereby forming the adhesive layer 130.

Next, a shielding layer 120 is formed on the surface of the adhesive layer 130. Specifically, the following methods can be used: a method of bonding a metal foil of a predetermined thickness to the adhesive layer 130; a method of forming a metal layer on the surface of the adhesive layer 130 by vapor deposition or wet coating. method.

Next, an insulating protective layer 110 is formed on the surface of the shielding layer 120. Specifically, the following method may be adopted: a solution of an insulating protective layer composition containing a material constituting the insulating protective layer 110 is applied to the surface of the shielding layer 120 and dried.

Then, by peeling off the base film, an electromagnetic wave shielding film can be obtained.

It should be noted that the adhesive layer 130 can also be used as the isotropic conductive adhesive layer 140 and the insulating protective layer 110 is formed on the surface of the isotropic conductive adhesive layer 140.

In order to adjust the arithmetic mean inclination and root mean square inclination of the surface of the insulating protective layer 110, the surface of the insulating protective layer 110 may also be processed by sandblasting or the like.

The above shows an example in which the electromagnetic wave shielding film is formed from the adhesive layer 130 side, and the electromagnetic wave shielding film may be formed sequentially from the insulating protective layer 110 side. At this time, using a base film with a fine pattern to pad print the fine pattern on the surface of the adhesive layer 130, the arithmetic mean and root mean square inclination of the surface of the adhesive layer 130 can also be measured. adjust.

[Example]

The following examples illustrate the present invention in detail. It should be noted that the following embodiments are only examples and do not limit the present invention in any way.

<Characteristic Evaluation>

〔Evaluation of bleeding〕

On the surface of the insulating protective layer of the electromagnetic wave shielding film, English letters and numbers of 1mm×2mm are printed on a screen printing plate, and the shapes of the letters and numbers are observed with a microscope to evaluate whether there is bleeding. If bleeding could not be confirmed, it was recorded as ○, and if it was confirmed that bleeding occurred and caused contour deformation and ink coloring unevenness (cissing), it was recorded as ×.

〔Evaluation of visual clarity〕

The visual clarity is evaluated by observing the 45° regular reflection. In a dark room, set up an LED lamp (manufactured by SUPRABEAM) at a height of 10cm on the table, so that the irradiation port of the LED lamp is approximately 45° from the vertical direction, and the electromagnetic wave shielding film is placed directly below the irradiation port and deviated 10cm from the horizontal direction. Location. Then, from the place where the electromagnetic wave shielding film was placed 10 cm in the horizontal direction and 10 cm in the vertical direction, the three English letters and numbers (0.5 mm in length, 0.2 mm in width, Observed at an interval of 0.1mm) to evaluate the legibility. If all outlines of the printed text can be clearly observed, it is recorded as ○, and if the printed text cannot be clearly observed, it is recorded as ×.

[Measurement of arithmetic mean slope and root mean square slope]

A laser microscope (manufactured by KEYENCE CORPORATION, VK-X200, 50 times objective lens) was used to observe any 5 fields of view on the surface of the insulating protective layer. According to JIS B 0601 (2001), the average value of the arithmetic mean tilt and the root mean square tilt was measured. measuring. It should be noted that the reference length is set to 280 μm.

[Measurement of L* value]

The L* value was measured with an integrating sphere spectrophotometer (manufactured by X-Rite, Ci64, tungsten lamp).

〔Measurement of gloss〕

60° gloss and 85° gloss were measured with BYK-Gardner gloss meter (portable gloss meter).

(Example 1)

-Preparation of conductive adhesive layer-

100 parts by mass of bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., jER1256), 0.1 parts by mass curing agent (manufactured by Mitsubishi Chemical Co., Ltd., ST14), and 47 parts by mass in a spherical shape were added to toluene In addition, the silver-coated copper powder with an average particle diameter of 10 μm ensures that the solid content reaches 20% by mass, and is stirred and mixed to prepare a conductive adhesive layer composition. The prepared adhesive layer composition is coated on the PET film whose surface has been demolded, and dried by heating to form an adhesive layer on the surface of the base film.

-Preparation of shielding layer-

On the surface of the prepared adhesive layer, a silver-plated layer with a thickness of 0.1 μm was formed by an evaporation method.

-Preparation of insulating protective layer-

Add 100 parts by mass of bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER1256), 0.1 parts by mass of curing agent (manufactured by Mitsubishi Chemical Corporation, ST14), and 15 parts by mass of black type epoxy resin to toluene Tokai Carbon Particles Co., Ltd., TOKABLACK # 8300/F), 10 parts by mass of fine particles, that is, urethane resin particles with an average particle diameter of 6 μm, ensure that the solid content reaches 20% by mass, and prepare an insulating protective layer composition. The composition was applied on the shielding layer prepared, and heated and dried to prepare the electromagnetic wave shielding film of Example 1.

The arithmetic mean inclination of the insulating protective layer surface is 43°, the root mean square inclination is 50°, the L* value is 18, the 60° gloss is 0.2%, and the 85° gloss is 0.3%. The presence or absence of bleeding was evaluated, and no unevenness in ink coloration was observed, and no bleeding was confirmed. The visual clarity of printed text is also good.

(Example 2)

Example 2 is the same as Example 1 except that the fine particles added to the insulating protective layer composition are changed to 10 parts by mass of urethane resin particles having an average particle diameter of 2 μm. The arithmetic mean inclination of the surface of the insulating protective layer prepared was 32°, the root mean square inclination was 39°, the L* value was 20, the 60° gloss was 1.1%, and the 85° gloss was 2.3%. The presence or absence of bleeding was evaluated, and no unevenness in ink coloration was observed, and no bleeding was confirmed. The visual clarity of printed text is also good.

(Example 3)

Example 3 is the same as Example 1 except that the fine particles added to the insulating protective layer composition are changed to 10 parts by mass of urethane resin particles having an average particle diameter of 5 μm. The arithmetic mean inclination of the insulating protective layer surface is 46°, the root mean square inclination is 52°, the L* value is 21, the 60° gloss is 0.3%, and the 85° gloss is 2.6%. The presence or absence of bleeding was evaluated, and no unevenness in ink coloration was observed, and no bleeding was confirmed. The visual clarity of printed text is also good.

(Example 4)

Example 4 is the same as Example 1 except that the fine particles added to the insulating protective layer composition are changed to 13 parts by mass of styrene-acrylonitrile resin particles having an average particle diameter of 5 μm. The arithmetic mean slope of the surface of the insulating protective layer is 35°, the root mean square tilt is 43°, the L* value is 18, the 60° gloss is 0.8%, and the 85° gloss is 2.1%. Evaluate whether there is bleeding, and the visual clarity of the printed text is good.

(Comparative example 1)

In Comparative Example 1, the black colorant added to the insulating protective layer composition was changed to 5 parts by mass, and fine particles were not added. The surface of the base film has undergone a mold release treatment and has an uneven shape. The insulating protective layer composition is applied to the surface of the base film and dried. After the base film and the shielding layer are bonded, the base film is peeled off from the surface of the insulating protective layer, thereby forming uneven migration Printed on its own insulating protective layer. Other conditions are the same as in Example 1. The arithmetic mean inclination of the insulating protective layer surface was 22°, the root mean square inclination was 31°, the L* value was 28, the 60° gloss was 2.0%, and the 85° gloss was 43.4%. Evaluate whether there is bleeding, and confirm that there is uneven ink coloration. The printed text cannot be distinguished under the cover of reflected light.

(Comparative example 2)

Comparative Example 2 is the same as Example 1 except that the black colorant added to the insulating protective layer composition is changed to 5 parts by mass and fine particles are not added. The arithmetic mean inclination of the insulating protective layer surface is 16°, the root mean square inclination is 25°, the L* value is 27, the 60° gloss is 11.1%, and the 85° gloss is 36.7%. Evaluate whether there is bleeding, and confirm that there is uneven ink coloration. The printed text cannot be distinguished under the cover of reflected light.

(Comparative example 3)

Comparative Example 3 was the same as Example 1 except that the black colorant added to the insulating protective layer composition was changed to 5 parts by mass and fine particles were not added. The arithmetic mean inclination of the insulating protective layer surface was 23°, the root mean square inclination was 30°, the L* value was 25, the 60° gloss was 4.2%, and the 85° gloss was 33.1%. Evaluate whether there is bleeding, and confirm that there is uneven ink coloration. Printed text in reflection Cannot be recognized under the cover of light.

(Comparative Example 4)

Comparative Example 4 was the same as Comparative Example 1 except that a film with a surface roughness of 0.6 μm was used as the base film. The arithmetic mean inclination of the insulating protective layer surface was 13°, the root mean square inclination was 19°, the L* value was 28, the 60° gloss was 8.0%, and the 85° gloss was 43.1%. The printed text cannot be distinguished under the cover of reflected light.

(Comparative Example 5)

Comparative Example 5 is the same as Example 1 except that the fine particles added to the insulating protective layer composition are changed to 3 parts by mass of urethane resin particles having an average particle diameter of 7 μm. The arithmetic mean inclination of the insulating protective layer surface was 14°, the root mean square inclination was 20°, the L* value was 26, the 60° gloss was 6.1%, and the 85° gloss was 36.9%. The printed text cannot be distinguished under the cover of reflected light.

Table 1 shows a list of the composition and characteristics of the insulating protective layer in each example and comparative example.

【Table 1】

The arithmetic mean inclination of the surface of the insulating protective layer of Examples 1 to 3 is above 30°, and the above insulating protective layer is confirmed to have no uneven ink coloring and printability good. Compared with the insulating protective layer of the comparative example, the insulating protective layer of Examples 1 to 3 did not bleed and had good visual clarity.

〔Industrial availability〕

The electromagnetic wave shielding film of the present invention can print small characters and the like with high accuracy, and is useful as an electromagnetic wave shielding film for electronic devices and the like.

110‧‧‧Insulation protection layer

120‧‧‧Shielding layer

130‧‧‧Adhesive layer

Claims (5)

An electromagnetic wave shielding film, comprising an insulating protective layer and a shielding layer, characterized in that the arithmetic mean inclination of the surface of the insulating protective layer is above 30°, and the root mean square inclination of the surface of the insulating protective layer is 35° ° above. The electromagnetic wave shielding film of claim 1, wherein the 85° glossiness of the surface of the insulating protective layer is 10% or less. The electromagnetic wave shielding film of claim 1 or 2, wherein the 60° gloss of the surface of the insulating protective layer is 2% or less. The electromagnetic wave shielding film of claim 1 or 2, wherein the insulating protective layer contains 50% of particles having an average particle diameter of 2 μm or more and 30 μm or less by 5 mass% or more and 30 mass% or less. The electromagnetic wave shielding film of claim 3, wherein the insulating protective layer contains 50% of particles having an average particle diameter of 2 μm or more and 30 μm or less by 5 mass% or more and 30 mass% or less.

Images