KR102432750B1 - electromagnetic shielding film - Google Patents

Abstract

The electromagnetic wave shielding film includes an insulating protective layer 110 and a shielding layer 120 . The insulating protective layer 110 has an arithmetic mean inclination at the surface of 30° or more.

Description

electromagnetic shielding film

The present invention relates to an electromagnetic wave shielding film.

In recent years, in smart phones and tablet-type information terminals, etc., the ability to transmit large amounts of data at high speed is required. In order to transmit a large amount of data at a high speed, it is necessary to use a high-frequency signal. However, when a high-frequency signal is used, electromagnetic noise is generated from the signal circuit provided on the printed wiring board, and the peripheral equipment is liable to malfunction. In order to prevent such a malfunction, it becomes important to shield a printed wiring board from electromagnetic waves.

In order to shield a printed wiring board, the method of affixing to a printed wiring board the electromagnetic wave shielding film which has an insulating layer and a shielding layer is examined (for example, refer patent document 1).

Moreover, for the purpose of concealing a circuit pattern, the electromagnetic wave shielding film which colored the insulating protective layer in black is examined (for example, refer patent document 2).

Further, for the purpose of improving the recognition of white print printed on the surface of the electromagnetic wave shielding film, adjusting the color tone of the insulating protective layer of the electromagnetic wave shielding film has been studied (for example, Patent Document 3) see).

Japanese Laid-Open Patent Publication No. 2004-095566 Japanese Laid-Open Patent Publication No. 2014-078574 Japanese Patent Publication No. 5796690

On the surface of the electromagnetic wave shielding film affixed to a printed wiring board, a symbol etc. are printed with white ink for the purpose of managing the said printed wiring board in the assembly process of an electronic device. However, in the conventional electromagnetic wave shielding film, printing by the white ink is easy to spread, and the productivity of the printing process using the white ink is low.

In addition, information terminals and the like in which the electromagnetic wave shielding film is used have a demand for light weight and miniaturization, and accordingly, the size of the electromagnetic wave shielding film is reduced, and characters printed on the electromagnetic wave shielding film are also reduced.

When the size of printing becomes small, it becomes difficult to recognize the character printed on the conventional electromagnetic wave shielding film. In particular, in a room with high illuminance, this influence becomes large.

In addition, in the conventional electromagnetic shielding film, when characters or symbols are printed by screen printing, ink bleeds out between the screen plate and the electromagnetic shielding film, the printing precision is lowered, and it is difficult to recognize small-sized characters. there is Even if the contrast is improved by adjusting the color tone of the insulating protective layer, there is no fundamental improvement in the decrease in visibility due to bleeding.

An object of the present disclosure is to realize an electromagnetic wave shielding film capable of easily recognizing small-sized characters and the like and capable of printing with high accuracy.

One aspect of the electromagnetic wave shielding film includes an insulating protective layer and a shielding layer, wherein the insulating protective layer has an arithmetic mean inclination on the surface of 30° or more.

ADVANTAGE OF THE INVENTION According to the electromagnetic wave shielding film of this indication, while making it easy to recognize a small-size character etc., it can print with high precision.

1 is a cross-sectional view showing an electromagnetic wave shielding film according to an embodiment.
2 is a cross-sectional view illustrating an electromagnetic wave shielding film according to a modified example.

Hereinafter, the electromagnetic wave shielding film of the present invention will be described in detail. However, this invention is not limited to the following embodiment, In the range which does not change the summary of this invention, it can change suitably and apply.

(electromagnetic wave shielding film)

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows typically the electromagnetic wave shielding film of this embodiment. As shown in FIG. 1 , the electromagnetic wave shielding film has an insulating protective layer 110 and a shielding layer 120 . On the surface of the shielding layer 120 on the opposite side to the insulating protective layer 110 , an adhesive layer 130 may be provided as needed. By providing an adhesive bond layer, an electromagnetic wave shielding film can be easily bonded to a printed wiring board.

(insulation protective layer)

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

By setting the arithmetic mean inclination of the insulating protective layer 110 to 30° or more, preferably 35° or more, and more preferably 40° or more, the surface area of the insulating protective layer 110 is increased, and the absorbency of ink is improved, Bleeding of ink at the time of screen printing can be suppressed. Thereby, the efficiency of printing operation can be improved.

From the viewpoint of reducing the spread, the value of the arithmetic mean inclination is preferably larger, but from the viewpoint of productivity of the insulating protective layer 110, the arithmetic mean inclination is preferably 80° or less, more preferably 70° or less.

In addition, the arithmetic mean slope in this indication can be measured based on JISB0601 (2001).

Moreover, as for the insulation protective layer, 35 degrees or more of root mean square inclinations may be sufficient, It is more preferable that it is 40 degrees or more, It is more preferable that it is 45 degrees or more. When the root mean square inclination is 35 degrees or more, the surface area of the insulating protective layer 110 becomes large, the absorbency of ink improves, and it can suppress the bleed-out of ink at the time of screen printing. Thereby, the efficiency of printing operation can be improved.

In addition, the root mean square inclination in this indication can be measured based on JISB0601 (2001).

A method for obtaining the insulating protective layer having an arithmetic mean inclination and a root mean square inclination within a predetermined range is not particularly limited, and a known method can be used. As such a method, the uneven shape of the release film is transferred to the insulating protective layer by applying and drying a resin composition for forming an insulating protective layer on the surface of the release film to which the concave-convex shape has been imparted by embossing, and a shielding layer. A method of forming an insulating protective layer having an uneven shape by coating and drying a resin composition containing fine particles on the surface of Then, well-known methods, such as the method of pressurizing the mold which has an uneven|corrugated shape, hardening the said curable composition layer, and peeling a mold, are mentioned as an example.

Among these, the method of apply|coating and drying the resin composition containing microparticles|fine-particles from a viewpoint of productivity, and obtaining the insulating protective layer which has an uneven|corrugated shape is preferable. In this case, the fine particles added to the insulating protective layer 110 are not particularly limited, but, for example, resin fine particles or inorganic fine particles can be used. The resin microparticles can be acrylic resin microparticles, polyacrylonitrile microparticles, polyurethane microparticles, polyamide microparticles, polyimide microparticles, and the like. The inorganic fine particles include calcium carbonate fine particles, calcium silicate fine particles, clay, kaolin, talc, silica fine particles, glass fine particles, diatomaceous earth, mica powder, alumina fine particles, magnesium oxide fine particles, zinc oxide fine particles, barium sulfate fine particles, aluminum sulfate fine particles, It can be set as calcium sulfate microparticles|fine-particles, magnesium carbonate microparticles|fine-particles, etc. These resin microparticles|fine-particles and inorganic microparticles|fine-particles may be used independently and may be used combining plurality. From the viewpoint of improving the scratch resistance of the insulating protective layer, inorganic fine particles are preferable.

The microparticles preferably have a 50% average particle diameter of 2 µm or more, more preferably 4 µm or more, from the viewpoint of causing appropriate unevenness on the surface of the insulating protective layer and increasing the arithmetic mean inclination and root mean square inclination, It is more preferable that it is 10 micrometers or more. Further, in order to suppress whitening of the insulating protective layer, the 50% average particle diameter is preferably 30 µm or less, and more preferably 20 µm or less.

The amount of fine particles added to the insulating protective layer 110 is preferably 3% by mass or more, more preferably 5% or more, from the viewpoint of increasing the arithmetic mean slope and root mean square inclination. Moreover, from a viewpoint of suppressing whitening of an insulation protective layer, it is preferable that it is 30 mass % or less, It is more preferable that it is 20 mass % or less, It is more preferable that it is 17 mass % or less.

A black-based colorant may be added to the insulating protective layer 110 . By adding a black-based colorant, the L* value of the insulating protective layer 110 can be reduced, and the visibility of characters can be further improved. When the character to be printed on the insulating protective layer 110 is white, the L* value is preferably set to 20 or less, more preferably 18 or less. In addition, the L* value in this indication can be measured based on JIS Z 8781-4 (2013).

The black colorant can be a black pigment or a mixed pigment obtained by blackening a plurality of pigments by subtractive color mixing. The black pigment may be, for example, any one of carbon black, Ketjen black, carbon nanotube (CNT), perylene black, titanium black, iron black, and aniline black, or a combination thereof. The mixed pigment can be used, for example, by mixing pigments such as red, green, blue, yellow, purple, cyan and magenta.

The particle size of the black colorant should just be capable of realizing a required L* value, but from the viewpoint of dispersibility and reduction of L* value, it is preferable that the average primary particle size is 20 nm or more, and it is 100 nm or less desirable. The average primary particle diameter of a black colorant can be calculated|required from the average value of about 20 primary particles which can be observed from the image magnified by about 50,000 times - 1 million times with a transmission electron microscope (TEM).

From a viewpoint of making L* value small, it is preferable to set it as 0.5 mass % or more, and, as for the addition amount of the black type coloring agent to the insulating protective layer 110, it is more preferable to set it as 1 mass % or more. However, the black-based colorant may be added as needed, and it is not necessary to add it.

When the 60° glossiness of the insulating protective layer 110 is set to 3% or less, preferably 2% or less, and more preferably 1% or less, appropriate light scattering occurs on the surface of the insulating protective layer 110, and glossiness is achieved. This is appropriately suppressed. Thereby, the visibility of printing can be improved. In addition, the 85° glossiness of the insulating protective layer 110 is preferably 10% or less, more preferably 3% or less, and still more preferably 1% or less.

In addition, 60 degree glossiness and 85 degree glossiness in this indication can be measured by the method shown in an Example.

It is preferable that the insulating protective layer 110 has required insulating properties and satisfies predetermined 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 insulation, and for example, a thermoplastic resin composition, a thermosetting resin composition, an active energy ray-curable composition, and the like can be used.

The thermoplastic resin composition is not particularly limited, but a styrene-based resin composition, a vinyl acetate-based resin composition, a polyester-based resin composition, a polyethylene-based resin composition, a polypropylene-based resin composition, an imide-based resin composition, and an acrylic resin composition may be used. can Although it does not specifically limit as a thermosetting resin composition, A phenol-type resin composition, an epoxy-type resin composition, a urethane-type resin composition, a melamine-type resin composition, an alkyd-type resin composition, etc. can be used. Although it does not specifically limit as an active energy ray-curable composition, For example, the polymeric compound etc. which have at least two (meth)acryloyloxy groups in a molecule|numerator can be used. These compositions may be used individually by 1 type, and may use 2 or more types together.

In addition to the above-described fine particles and colorants, the insulating protective layer 110 includes, if necessary, a curing accelerator, a tackifier, an antioxidant, a pigment, a dye, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling agent, a filler, a flame retardant, a viscosity A control agent, an anti-blocking agent, etc. may be contained.

The thickness of the insulating protective layer 110 is not particularly limited and can be appropriately set as necessary. From the viewpoint of sufficiently protecting the shielding layer, it is preferably 1 µm or more, and more preferably 4 µm or more. Moreover, from a viewpoint of ensuring the flexibility of an electromagnetic wave shielding film, it is preferable that it is 10 micrometers or less, and it is more preferable that it is 5 micrometers or less.

(shielding layer)

The shielding layer 120 of this embodiment can be made into a metal layer. The shielding layer 120 may be a metal layer made of any one of nickel, copper, silver, tin, gold, palladium, aluminum, chromium, titanium, and zinc, or an alloy containing two or more thereof. In addition, what is necessary is just to select the material and thickness of a metal layer suitably according to the electromagnetic shielding effect and repeated bending and sliding resistance required. From the viewpoint of obtaining a sufficient electromagnetic shielding effect, the thickness of the metal layer is preferably 0.1 µm or more. Moreover, it is preferable to set it as 8 micrometers or less from viewpoints, such as productivity and flexibility. The metal layer can be formed by an electrolytic plating method, an electroless plating method, a sputtering method, an electron beam vapor deposition method, a vacuum vapor deposition method, a CVD method, a metal organic method, or the like. In addition, a metal layer can also be formed with metal foil, a metal nanoparticle, a flaky metal particle, etc.

(Adhesive layer)

The electromagnetic wave shielding film of this embodiment may be equipped with the adhesive bond layer 130 on the opposite side to the insulating protective layer 110 of the shielding layer 120 . The adhesive layer 130 can be formed of an adhesive resin composition. The adhesive resin composition is not particularly limited, but a styrene-based resin composition, a vinyl acetate-based resin composition, a polyester-based resin composition, a polyethylene-based resin composition, a polypropylene-based resin composition, an imide-based resin composition, an amide-based resin composition, and an acrylic resin composition Thermosetting resin compositions, such as a thermoplastic resin composition, such as a resin composition, and a phenol-type resin composition, an epoxy resin composition, a urethane resin composition, a melamine-type resin composition, and an alkyd-type resin composition, etc. can be used. These may be used individually by 1 type, and may use 2 or more types together.

The adhesive layer 130 may be a layer having isotropic conductivity or anisotropic conductivity, if necessary. When the adhesive layer 130 is a conductive layer, conductive fine particles may be added to the adhesive resin composition.

Although the electroconductive microparticles|fine-particles are not specifically limited, Metal microparticles, a carbon nanotube, carbon fiber, a metal fiber, etc. can be used. For example, metal fine particles, such as silver powder, copper powder, nickel powder, solder powder, and aluminum powder, can be used. In addition, silver-coated copper powder in which copper powder is plated with silver, and metal-coated fine particles in which polymer fine particles, glass beads, or the like are coated with a metal can also be used. Among these, copper powder or silver-coated copper powder which can be obtained cheaply from a viewpoint of economical efficiency is preferable.

Although the 50% average particle diameter of electroconductive particle is not specifically limited, From a viewpoint of obtaining favorable electroconductivity, 0.5 micrometer or more is preferable. Moreover, it is preferable to set it as 15 micrometers or less from a viewpoint of making a conductive adhesive layer thin.

Although the shape of electroconductive particle is not specifically limited, Spherical shape, flat shape, scale shape, a dendrite shape, etc. can be selected suitably.

Although the thickness of the adhesive bond layer 130 can be adjusted as needed, it is preferable to set it as 0.5 micrometer or more from a viewpoint of obtaining favorable adhesiveness. Moreover, it is preferable to set it as 20 micrometers or less from a viewpoint of making an electromagnetic wave shielding film thin.

Although the electromagnetic wave shielding film has been described with respect to the configuration having the insulating protective layer 110, the shielding layer 120, and the adhesive layer 130, as shown in FIG. 2, the insulating protective layer 110 and the isotropic conductive adhesive It can also be set as the structure which has the layer 140.

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

(Manufacturing method of shielding film)

An electromagnetic wave shielding film can be manufactured by a well-known manufacturing method. An example is shown below.

First, the adhesive layer 130 having conductivity is formed on the support film on which the surface has been subjected to release treatment. Specifically, the adhesive layer 130 is formed by applying and drying a solution of the adhesive layer composition including the material constituting the adhesive layer 130 on the surface of the support film.

Next, the shielding layer 120 is formed on the surface of the adhesive layer 130 . Specifically, a method of bonding a metal foil formed in advance to a predetermined thickness to the adhesive layer 130 or a method of forming a metal layer on the surface of the adhesive layer 130 by vapor deposition or plating may be used.

Next, the insulating protective layer 110 is formed on the surface of the shielding layer 120 . Specifically, a method of applying and drying a solution of the insulating protective layer composition including the material constituting the insulating protective layer 110 on the surface of the shielding layer 120 may be used.

Then, an electromagnetic wave shielding film can be obtained by peeling a support body film.

Also, by using the adhesive layer 130 as the isotropic conductive adhesive layer 140 , the insulating protective layer 110 may be formed on the surface of the isotropic conductive adhesive layer 140 .

In order to adjust the arithmetic mean inclination and the root mean square inclination on the surface of the insulating protective layer 110 , the surface of the insulating protective layer 110 may be subjected to a process such as sand blasting.

Although an example of forming the adhesive layer 130 from the side is shown, it may be sequentially formed from the insulating protective layer 110 side. In this case, by transferring the fine pattern to the surface of the adhesive layer 130 using a support film having a fine pattern, the arithmetic mean inclination and the root mean square inclination on the surface of the adhesive layer 130 may be adjusted.

[Example]

Hereinafter, the present invention will be described in detail by way of Examples. Incidentally, the following examples are illustrative and do not limit the present invention in any way.

<Characteristic evaluation>

[Evaluation of the spread]

On the surface of the insulating protective layer of the electromagnetic wave shielding film, alphanumeric characters of 1 mm x 2 mm were printed using a screen printing plate, and the shape of the alphanumeric characters was observed under a microscope to evaluate the presence or absence of bleeding. When bleeding was not recognized, it was set as (circle), when bleeding occurred, and when deformation|transformation and splashing of ink were recognized by the outline.

[Evaluation of visibility]

Visibility was performed by the method of observing a 45 degree specular reflection. Installed so that the irradiation port of the LED light (manufactured by SUPRABEAM) is approximately 45° from the vertical direction at a height of 10 cm from the tabletop in the darkroom, and at a position 10 cm from the horizontal direction immediately below the irradiation port, the electromagnetic wave shielding described above The film was mounted. Next, from a position 10 cm in the horizontal direction and 10 cm in the vertical direction from the position where the electromagnetic wave shielding film is mounted, three alphanumeric characters (0.5 mm vertical, 0.2 mm horizontal, 0.1 mm interval) was observed, and the ease of observation was evaluated. When the whole outline of printing was visually recognizable, it was set as (circle), and when printing was not visually visually visually recognizable, it was set as X.

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

Random 5 fields of view of the surface of the insulating protective layer were observed using a laser microscope (manufactured by Keyence Co., Ltd., VK-X200, objective lens 50x), and arithmetic mean slope and root mean square slope in accordance with JIS B 0601 (2001) was measured. And the reference length was 280 micrometers.

[Measurement of L* value]

The L* value was measured using the integrating sphere spectrophotometer (The X-Rite company make, Ci64, a tungsten light source).

[Measurement of glossiness]

The 60° glossiness and 85° glossiness were measured by a BYK Gardner Micro-Gloss (portable gloss meter).

(Example 1)

-Production of conductive adhesive layer-

100 parts by mass of a bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., jER1256) in toluene so that the solid content is 20 mass%, 0.1 parts by mass of a curing agent (manufactured by Mitsubishi Chemical Co., Ltd., ST14), average particle size 47 mass parts of spherical silver-coated copper powder was added to 10 micrometers, it stirred and mixed, and the electroconductive adhesive bond layer composition was prepared. The adhesive bond layer was formed in the support film surface by apply|coating the obtained adhesive bond layer composition to the PET film which carried out the mold release process, and heat-drying.

-Production of shielding layer-

On the surface of the obtained adhesive bond layer, the 0.1-micrometer-thick silver layer was formed by the vapor deposition method.

-Production of insulating protective layer-

100 parts by mass of bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., jER1256) in toluene so that the solid content is 20 mass%, 0.1 parts by mass of (Mitsubishi Chemical Co., Ltd., ST14) as a curing agent, black 15 parts by mass of carbon particles (manufactured by Tokai Carbon Co., Ltd., Toka Black #8300/F) as a colorant and 10 parts by mass of urethane resin particles having an average particle diameter of 6 µm as fine particles were blended to prepare an insulation protective layer composition. This composition was apply|coated to the obtained shielding layer, it heat-dried, and the electromagnetic wave shielding film of Example 1 was obtained.

The obtained insulating protective layer had an arithmetic mean inclination of 43°, a root mean square inclination of 50°, an L* value of 18, a glossiness of 60° of 0.2%, and a glossiness of 85° of 0.3%. When the presence or absence of bleeding was evaluated, splashing of ink, etc. were not observed, but bleeding was not recognized. Moreover, the visibility of printing was also favorable.

(Example 2)

It carried out similarly to Example 1 except that the microparticles|fine-particles added to the insulation protective layer composition were 10 mass parts of urethane resin particles with an average particle diameter of 2 micrometers. The obtained insulating protective layer had an arithmetic mean inclination of 32°, a root mean square inclination of 39°, L* value of 20 and 60° glossiness of 1.1%, and 85° glossiness of 2.3%. When the presence or absence of bleeding was evaluated, splashing of ink, etc. were not observed, but bleeding was not recognized. Moreover, the visibility of printing was also favorable.

(Example 3)

It carried out similarly to Example 1 except the point that the microparticles|fine-particles added to the insulation protective layer composition were 10 mass parts of urethane resin particles with an average particle diameter of 5 micrometers. The obtained insulating protective layer had an arithmetic mean inclination of 46°, a root mean square inclination of 52°, an L* value of 21, a glossiness of 60° of 0.3%, and a glossiness of 85° of 2.6%. When the presence or absence of bleeding was evaluated, splashing of ink, etc. were not observed, but bleeding was not recognized. Moreover, the visibility of printing was also favorable.

(Example 4)

The same procedure as in Example 1 was performed except that the fine particles added to the insulating protective layer composition were 13 parts by mass of acrylic styrene resin particles having an average particle diameter of 5 µm. The obtained insulating protective layer had an arithmetic mean inclination of 35°, a root mean square inclination of 43°, an L* value of 18, a gloss of 60° of 0.8%, and a gloss of 85° of 2.1%. When the presence or absence of spreading was evaluated, the visibility of printing was favorable.

(Comparative Example 1)

The black colorant added to the insulating protective layer composition was 5 parts by mass, and no fine particles were added. The insulating protective layer composition is applied to the surface of the support film having an uneven shape on the surface subjected to the release treatment, dried, bonded to the shielding layer, and then the support film is peeled from the surface of the insulation protective layer, whereby the uneven insulation is transferred A protective layer was formed. Other conditions were the same as in Example 1. The obtained insulating protective layer had an arithmetic mean inclination of 22°, a root mean square inclination of 31°, an L* value of 28, a glossiness of 60° of 2.0%, and a glossiness of 85° of 43.4%. When the presence or absence of bleeding was evaluated, splashing of ink was recognized. In addition, printing was mixed with reflected light and could not be visually recognized.

(Comparative Example 2)

It was carried out similarly to Example 1 except that the black type coloring agent added to the insulation protective layer composition was 5 mass parts, and the point which did not add microparticles|fine-particles. The obtained insulating protective layer had an arithmetic mean inclination of 16°, a root mean square inclination of 25°, an L* value of 27, a glossiness of 60° of 11.1%, and a glossiness of 85° of 36.7%. When the presence or absence of bleeding was evaluated, splashing of ink was recognized. In addition, printing was mixed with reflected light and could not be visually recognized.

(Comparative Example 3)

It was carried out similarly to Example 1 except that the black type coloring agent added to the insulation protective layer composition was 5 mass parts, and the point which did not add microparticles|fine-particles. The obtained insulating protective layer had an arithmetic mean inclination of 23°, a root mean square inclination of 30°, L* values of 25 and 60° glossiness of 4.2%, and 85° glossiness of 33.1%. When the presence or absence of bleeding was evaluated, splashing of ink was recognized. In addition, printing was mixed with reflected light and could not be visually recognized.

(Comparative Example 4)

As a support body film, it carried out similarly to the comparative example 1 except the point which used the thing whose surface roughness is 0.6 micrometer. The obtained insulating protective layer had an arithmetic mean inclination of 13°, a root mean square inclination of 19°, L* values of 28, 60° glossiness of 8.0%, and 85° glossiness of 43.1%. Printing could not be visually recognized because it was mixed with reflected light.

(Comparative Example 5)

It carried out similarly to Example 1 except that the fine particle added to the insulation protective layer composition was 3 mass parts of urethane resin particles with an average particle diameter of 7 micrometers. The obtained insulating protective layer had an arithmetic mean inclination of 14°, a root mean square inclination of 20°, an L* value of 26, 60° glossiness of 6.1%, and 85° glossiness of 36.9%. Printing could not be visually recognized because it was mixed with reflected light.

In Table 1, the composition and characteristics of the insulating protective layer for each Example and Comparative Example are summarized and shown.

[Table 1]

In all of the insulating protective layers of Examples 1 to 3 having an arithmetic mean inclination on the surface of 30° or more, ink repelling was not recognized, and the printability was good. In addition, the insulating protective layer of Examples 1 to 3 had good bleed and visibility compared with the insulating protective layer of Comparative Example.

[Industrial Applicability]

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

110: insulating protective layer
120: shielding layer
130: adhesive layer
140: isotropic conductive adhesive layer

Claims (1)

an insulating protective layer and a shielding layer;
The insulating protective layer has an arithmetic mean inclination on the surface of 30° or more, and a root mean square inclination on the surface of 35° or more, an electromagnetic wave shielding film.

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