KR102250899B1 - Electromagnetic wave shielding film for flexible printed circuit board and the preparation method thereof - Google Patents

Abstract

The present invention is an insulating layer; A mesh metal layer formed on one surface of the insulating layer and including a plurality of metal patterns in a mesh shape; And an electromagnetic wave shielding film for a flexible printed circuit board (FPCB) including a conductive adhesive layer formed on the insulating layer while covering the mesh metal layer and including a conductive filler and a resin, and a method of manufacturing the same.
In the present invention, unlike the existing electromagnetic wave shielding film, since it includes a metal layer in the form of a mesh, it has excellent economic efficiency and excellent electromagnetic wave shielding performance, and also has excellent physical properties such as conductivity, flexibility, and heat resistance.

Description

Electromagnetic shielding film for flexible printed circuit boards and its manufacturing method {ELECTROMAGNETIC WAVE SHIELDING FILM FOR FLEXIBLE PRINTED CIRCUIT BOARD AND THE PREPARATION METHOD THEREOF}

The present invention is a shielding film for shielding electromagnetic waves generated from electronic components such as printed circuit boards used in electronic products such as computers, communication devices, printers, mobile phones, and video cameras, communication devices such as cables, wires, or communication parts, and the like. It relates to a manufacturing method.

BACKGROUND ART In general, there is an increasing demand for miniaturization, flatness, and high functionality of electronic devices. In order to meet these demands, complex electromagnetic wave noise is generated by implementing components of different frequency ranges in the same electronic device, and it is becoming difficult to establish countermeasures against such complex electromagnetic wave noise. On the other hand, the demand for a thinner data transmission cable and less electromagnetic noise emission is also increasing. In the case of transmitting a large amount of data, there are frequent cases of data error and data loss due to data interference caused by electromagnetic noise.

In order to satisfy electromagnetic compatibility, electromagnetic wave noise generated from various electric/electronic and communication devices should be reduced as much as possible, and electromagnetic wave sensitivity to external electromagnetic environment should be reduced to reinforce the electromagnetic wave resistance of the device itself. The most important characteristics required for electromagnetic wave compatibility products inserted in various electric/electronic and communication devices are that the electromagnetic wave shielding rate and absorption rate must be large, and the electromagnetic wave compatibility product must be small and thin in accordance with the trend of light, thin and short devices.

As a countermeasure for solving the above-described electromagnetic noise problem, a shielding film in which a metal layer and a conductive adhesive layer are sequentially provided on one or more insulating layers are frequently used. At this time, an expensive metal, such as silver (Ag), is mainly used as a shielding material for the metal layer and the conductive adhesive layer, and the amount of metal needs to be increased in order to fully exhibit their shielding effect. Therefore, economical deterioration due to the use of expensive metals is inevitably caused. In addition, although a thin metal layer is required to be applied to thinner electronic devices, there is a problem in that the yield is deteriorated due to poor adhesion between the thin metal layer and other resin-based substrate films.

The inventors of the present invention have been devised to solve the above-described problems, and instead of forming a sealed metal layer on the conventional insulating layer, a predetermined metal pattern is formed using a conductive material, which is an electronic shielding material, while maintaining the gap therebetween. It was conceived that if an open metal layer arranged in a row was formed, a shielding effect comparable to that of the prior art could be exhibited while reducing the amount of expensive metal used.

Accordingly, the present invention includes a mesh metal layer in which a plurality of metal patterns are arranged in a mesh form, and not only improves economic efficiency, but also exhibits excellent shielding properties, heat resistance, chemical resistance, flexibility, etc., and a novel structure of an electromagnetic wave shielding film and a manufacturing method thereof. It aims to provide.

The present invention is an insulating layer; A mesh metal layer formed on one surface of the insulating layer and including a plurality of metal patterns in a mesh shape; And a conductive adhesive layer formed on the insulating layer while covering the mesh metal layer and including a conductive filler and a resin.

According to a preferred example of the present invention, the pattern of the mesh metal layer may be a shape selected from the group consisting of a circle, a diagonal shape, a polygonal shape of a triangle or more, and an amorphous shape. In addition, the mesh metal layer may be a single layer or a plurality of layers of two or more layers.

In the present invention, the average line width of the mesh metal layer may be in the range of 20 to 500 μm.

According to another preferred example of the present invention, the insulating layer may include a thermosetting resin, and may include 3 to 30 parts by weight of an electrically non-conductive organic or inorganic filler based on 100 parts by weight of the insulating layer.

According to another preferred example of the present invention, the conductive adhesive layer includes a conductive filler and a resin, and the conductive filler may be a copper filler coated with Ag, Cu, Ni, Al, Ag, a nickel filler, or a polymer filler.

According to a preferred example of the present invention, a release film may be further included on the insulating layer and the conductive adhesive layer, respectively.

In addition, the present invention provides a method of manufacturing the above-described electromagnetic wave shielding film.

For a preferred example of the manufacturing method, (i) coating a thermosetting resin composition for forming an insulating layer on the first surface of the first base film and drying to form an insulating layer; (ii) forming a mesh metal layer in which a predetermined pattern is formed in a mesh shape by printing an ink composition containing an electromagnetic wave shielding film on the insulating layer; (iii) forming a conductive adhesive layer by coating and drying a resin composition for forming a conductive adhesive layer including a conductive filler and a thermosetting resin on the first surface of the second base film; And (iv) laminating the first base film and the second base film, arranging so that the mesh metal layer of the first base film and the conductive adhesive layer of the second base film are in contact with each other, and then compressing through a pressing process. It can be configured.

Here, it is preferable that the insulating layer formed in step (i) is in a semi-cured state (B-stage).

The novel electromagnetic wave shielding film according to the present invention forms a predetermined metal pattern using a conductive material, which is an electromagnetic shielding material, but includes an open metal layer continuously arranged while maintaining a gap between them, so that the use of expensive metals It is possible to exhibit a shielding effect comparable to that of the prior art while reducing the value.

In addition, despite the presence of the metal layer, since the insulating layer and the conductive adhesive layer are bonded to each other between the mesh patterns, excellent adhesion, flexibility, and interlayer adhesion can be exhibited due to the affinity of the resin components included in these layers.

1 to 4 are schematic diagrams each showing a configuration of an electromagnetic wave shielding film according to an embodiment of the present invention.
5 to 8 are schematic diagrams showing various mesh patterns constituting the mesh metal layer of the electromagnetic wave shielding film according to the present invention.
9 is a shape of a coupon manufactured for evaluating a shielding rate of an electromagnetic shielding film.
10 is a diagram showing a method and evaluation criteria for evaluating chemical resistance of an electromagnetic wave shielding film.
<Explanation of symbols for major parts of drawings>
100, 110, 120, 130: electromagnetic wave shielding film for forming a flexible circuit board
10: insulating layer 20: mesh metal layer
30: conductive adhesive layer 40: release film
50: pattern of the mesh metal layer

Hereinafter, the present invention will be described in detail.

The electromagnetic wave shielding film refers to a film that is laminated on the outermost side (upper coverlay) of a flexible printed circuit board to shield electromagnetic interference (EMI) noise. Such an electromagnetic wave shielding film is required for various physical properties, and largely excellent electromagnetic wave shielding effect, bending properties, excellent thermal stability, chemical resistance, abrasion resistance, and low resistance change are required.

As a conventional electromagnetic shielding film, a film in which a metal layer and a conductive adhesive layer are sequentially provided on one or more insulating layers is used. At this time, the metal layer of a metal material is disposed between the resin-based insulating layer and the conductive adhesive layer. , While there is an advantage of increasing the electromagnetic wave shielding effect due to the metal layer between the insulating layer and the conductive adhesive layer, the interlayer adhesion is poor due to the heterogeneity between them. In addition, since an expensive metal, such as silver (Ag), is mainly used as a shielding material for the metal layer and the conductive adhesive layer, economical deterioration is inevitably caused by the use of expensive metals to exert a shielding effect. In addition, since the metal layer is in the form of a metal film, it may be a cause of impairing the bending resistance of the film and the filling property of a high step between the coverlay and the ground pattern during the thermocompression process.

Accordingly, in the present invention, in order to provide an electromagnetic wave shielding film for forming a novel flexible printed circuit board (FPCB) that not only improves economic efficiency, but also exhibits excellent shielding properties, heat resistance, chemical resistance, and flexibility, between the insulating layer and the conductive adhesive layer. It is characterized in that an open metal layer in which a predetermined metal pattern is continuously arranged is formed.

Since such an open metal layer is composed of a plurality of metal patterns in the form of a mesh, not only can the use of expensive metals be reduced, but also economical efficiency can be improved, and shielding characteristics equivalent to that of a shielding film using a metal layer in the form of an existing sealed metal foil. Can be indicated.

In addition, although the metal layer is disposed between the resin-based insulating layer and the conductive adhesive layer, the insulating layer and the conductive adhesive layer are connected and bonded between the mesh patterns of the metal layer.Thus, the interlayer adhesion is significant due to the affinity between the resins. Can be improved with.

In addition, since the insulating layer and the conductive adhesive layer are connected to each other through the mesh-type metal pattern, it does not impair the bending resistance of the electromagnetic wave shielding film even when the metal layer is included, as well as reducing the overall thickness and flexibility of the flexible printed circuit board. ) Can be given. Therefore, there is an advantage that the application field for the product line for high step and thin plate can be broadened.

<Electromagnetic shielding film for flexible printed circuit board (FPCB) formation>

Hereinafter, an electromagnetic wave shielding film for forming a flexible printed circuit board (FPCB) according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The electromagnetic wave shielding film of the present invention may be largely divided into an insulating layer 10 and a conductive layer, wherein the conductive layer includes a mesh metal layer 20 and a conductive adhesive layer 30.

Referring to Figure 1, the electromagnetic shielding film 100 of the present invention, the insulating layer 10; A mesh metal layer 20 formed on one surface of the insulating layer; And a conductive adhesive layer 30 formed on the insulating layer while covering the mesh metal layer, and have a structure in which they are sequentially stacked.

<insulation layer>

In the electromagnetic wave shielding film of the present invention, the insulating layer is finally present on the outermost side of the film, giving mechanical strength of the electromagnetic wave shielding film, and exhibiting thermal stability, chemical resistance, scratch resistance, etc. along with the bending properties of the film. Do it.

The insulating layer is in the form of a coating layer or a film, and may be formed by curing a thermosetting composition including a conventional thermosetting resin and a curing agent known in the art.

Non-limiting examples of thermosetting resins usable in the present invention include epoxy resins, phenol resins, vegetable oil-modified phenol resins, xylene resins, guanamine resins, diallylphthalate resins, vinyl ester resins, unsaturated polyester resins, furan resins, It may be one or more selected from the group consisting of polyimide resin, polyurethane resin, cyanate resin, maleimide resin, and benzocyclobutene resin. Preferably, it is an epoxy resin, a phenol resin, or a vegetable oil-modified phenol resin. Double epoxy resin is preferred because of its excellent reactivity and heat resistance.

As the epoxy resin, a conventional epoxy resin known in the art may be used without limitation, and it is preferable that two or more epoxy groups are present in one molecule.

Non-limiting examples of usable epoxy resins include bisphenol A/F/S type resins, novolak type epoxy resins, alkylphenol novolak type epoxy, biphenyl type, aralkyl type, naphthol ( Naphthol) type, dicyclopentadiene type, or a mixture thereof.

More specific examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, anthracene epoxy resin, biphenyl type epoxy resin, tetramethyl biphenyl type epoxy resin, phenol novolac Type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol S novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthol novolac type epoxy resin, naphthol phenol co-condensed novolac type epoxy resin , Naphthol coreazole co-condensed novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, triphenyl methane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene phenol addition reaction type epoxy resin, phenol arral And a kill type epoxy resin, a polyfunctional phenol resin, and a naphthol aralkyl type epoxy resin. At this time, the above-described epoxy resin may be used alone or two or more types may be used in combination.

In the present invention, a conventional curing agent known in the art may be used without limitation, and may be appropriately selected and used according to the type of epoxy resin to be used. Non-limiting examples of the curing agent that can be used include phenol-based, anhydride-based, dicyanamide-based, and curing agents, among which phenol-based curing agents are preferable because they can further improve heat resistance and adhesion.

Non-limiting examples of the phenolic curing agent include phenol novolac, cresol novolak, bisphenol A novolac, naphthalene type, and the like, and these may be used alone or in combination of two or more.

Meanwhile, the insulating layer according to the present invention may further include a conventional electric non-conductive filler known in the art in order to effectively show the mechanical properties and low resistance change of the final product.

Such an electrically non-conductive filler may be used by mixing an organic filler, an inorganic filler, or both, and for example, it is preferable to use an electrically non-conductive carbon black, a dye, or a mixture of one or more thereof.

The content of the electrical non-conductive filler may be appropriately adjusted in consideration of the mechanical properties, low resistance change, and other properties of the insulating layer described above, and for example, may be in the range of 0.5 to 5 parts by weight based on 100 parts by weight of the insulating layer. .

Since it is preferable that the insulating layer of the present invention contains a flame retardant, it is preferable to cure the above-described thermosetting resin and the curing agent component by containing a flame retardant.

As the flame retardant, conventional flame retardants known in the art may be used without limitation, but flame retardants such as organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicon-based flame retardants, and metal hydroxides are preferred.

Specific examples of the phosphorus compound-based flame retardant include triaryl-isopropyl phosphate, tris(3-hydroxypropyl) phosphine oxide, 1,3-phenylene-screw (zikisirenyl) phosphate, or 2,2-screw ( phenol condensate of p-hydroxyphenyl) propane trichlorophosphine oxide polymerization product (polymerization degree 1 to 3), phosphate compound, phosphorus ester compound such as aromatic group condensed phosphoric ester, or ammonium polyphosphoric acid, Ammonium polyphosphoric acid, butyl acid phosphate, butoxyethyl acid phosphate, melamine phosphate, or red phosphorus.

Further, specific examples of the nitrogen compound-based flame retardant include melamine derivatives such as melamine, melamine cyanurate, meram, melem, or melon. The above-described flame retardant may be used alone or in combination of two or more.

The content of the flame retardant is not particularly limited, and may be appropriately adjusted within a conventional range known in the art.

In the electromagnetic wave shielding film of the present invention, the thickness of the insulating layer can be appropriately adjusted in consideration of handling properties of the film, physical rigidity, and thinning of the substrate. For example, it may be in the range of 5 to 20 µm, and preferably in the range of 5 to 7 µm.

The insulating layer according to the present invention may exhibit the same flexibility as a conventional flexible copper clad laminate (FCCL), and may simultaneously exhibit 2H or more scratch resistance and chemical resistance capable of maintaining adhesive strength of 5B or more after a crosscut test after an excellent chemical resistance test. .

<Mesh metal layer>

In the electromagnetic wave shielding film of the present invention, the mesh metal layer is formed on one surface of the insulating layer, and includes a conductive material to exert an electromagnetic wave shielding effect.

Unlike the conventional sealed metal layer, in the present invention, an open metal layer is formed on the insulating layer by using a conductive material, which is an electromagnetic shielding material.

The open metal layer forms a structure in which a predetermined metal pattern is continuously arranged while maintaining a gap therebetween. Through this, a shielding effect comparable to that of the prior art can be obtained despite the use of a small amount of expensive metal.

In the mesh metal layer according to the present invention, a plurality of metals form a predetermined pattern, but they are formed in a mesh form, where the shape of the metal pattern is not particularly limited as long as it exhibits an electromagnetic wave shielding effect. For example, it may have a circular shape, an oblique shape, a triangular or more polygonal shape, or an amorphous shape. In this case, the polygon may be a triangle, a square, a pentagon, a hexagon, an octagon, etc. (see FIGS. 5 to 8).

In addition, the mesh metal layer may be a single layer or a plurality of layers of two or more layers.

Here, when the mesh metal layer is a plurality of layers of two or more layers, the mesh metal layer and the conductive adhesive layer may be alternately disposed with each other. Preferably, conductive adhesive layers are alternately provided between the plurality of mesh metal layers, and the plurality of mesh metal layers spaced apart from each other around the conductive adhesive layer may be disposed such that a plurality of metal patterns correspond to each other or cross each other. Here, the plurality of mesh metal layers may be conveniently divided into a first mesh metal layer (first pattern) formed on the conductive adhesive layer and in contact with the insulating layer and a second mesh metal layer (second pattern) formed under the conductive adhesive layer. At this time, the second mesh metal layer (second pattern) formed under the conductive adhesive layer is directly connected to the FPCB ground pattern, thereby reducing contact resistance and improving electromagnetic wave shielding rate. In addition, as the line width of the second mesh metal layer (the second pattern) formed under the conductive adhesive layer is thinner, the adhesion to the FPCB coverlay may be maintained. Accordingly, the second pattern may have a line width of 50 μm or less, preferably 20 to 30 μm. In addition, the aperture ratio of the second pattern must be maintained at 50% or more.

In the electromagnetic wave shielding film according to the present invention, the mesh metal layer may be made of a conventional electromagnetic wave shielding material known in the art. For example, it is preferable to be made of at least one conductive metal material selected from the group consisting of silver (Ag), gold (Au), copper (Cu), and aluminum (Al).

The average line width of the mesh metal layer is not particularly limited, but may be, for example, in the range of 20 to 500 μm. At this time, when the mesh metal layer is composed of a plurality of layers, the ratio of the opening area of the first mesh metal layer (first pattern) formed on the conductive adhesive layer in contact with the insulating layer may be less than 50%, preferably in the range of 10 to 45%. It may be, and the line width may be in the range of 50 to 500㎛. In addition, the line width of the second mesh metal layer (second pattern) formed under the conductive adhesive layer may be 50 μm or less, preferably 20 to 50 μm, and more preferably 20 to 30 μm. In addition, the ratio of the opening area may be 50% or more, preferably 70 to 85%.

In the electromagnetic wave shielding film of the present invention, the thickness of the mesh metal layer may be appropriately adjusted in consideration of the electromagnetic wave shielding power of the film. For example, it may be in the range of 0.1 to 10 µm, and preferably in the range of 0.1 to 1 µm.

<Conductive adhesive layer>

In the electromagnetic wave shielding film of the present invention, the conductive adhesive layer is formed on the insulating layer while covering the mesh metal layer, and includes a conductive material to exhibit an electromagnetic wave shielding effect and at the same time exhibit adhesion, flexibility and interlayer adhesion. Plays a role. In addition, since the electromagnetic shielding film is also in charge of fixing the film to the adherend, when it is attached to a flexible printed circuit board (FPCB) and used, it stably connects to the electrical circuit of the printed circuit board, and the generated electrical noise is emitted to the outside or the Intrusion into the printed circuit board can be effectively shielded.

The conductive adhesive layer includes a thermosetting resin component and a conductive filler, respectively, in order to exhibit adhesion and electromagnetic shielding effects.

The conductive filler may be a conventional conductive filler known in the art without limitation, and may be, for example, a copper filler coated with Ag, Cu, Ni, Al, or Ag, or a nickel filler. Alternatively, it may be a polymer filler, a filler coated with a metal plate, such as resin balls or glass beads, or a mixture thereof.

Here, silver (Ag) is expensive, copper (Cu) lacks the reliability of heat resistance, and aluminum (Al) lacks the reliability of moisture resistance, so silver (Ag), copper (Cu) filler coated with silver or nickel ( It is preferable to use a Ni) filler.

The content of the conductive filler is not particularly limited as long as it exhibits an electromagnetic wave shielding effect, and may be, for example, in the range of 30 to 70 parts by weight based on 100 parts by weight of the conductive adhesive layer.

The resin that can be used in the conductive adhesive layer of the present invention may be a conventional thermosetting resin known in the art without limitation. For example, it may be the same component as the thermosetting resin constituting the above-described insulating layer. In this case, a curing agent, a flame retardant, or all of them may be additionally included, and their components may also be the same as or different from the components constituting the above-described insulating layer.

In the electromagnetic wave shielding film of the present invention, the thickness of the conductive adhesive layer may be appropriately adjusted in consideration of the electromagnetic wave shielding power, flexibility, adhesion, interlayer adhesion, and the like of the film. For example, it may be in the range of 2 to 30 µm, and preferably in the range of 3 to 15 µm.

According to an example of the present invention, the total thickness of the conductive layer in which the mesh metal layer and the conductive adhesive layer are combined may be appropriately adjusted according to the ultra-bending use or the high-step response purpose. For example, in the case of ultra-bending use, the thickness of the conductive layer may be a thin plate in the range of 3 to 5 µm, and in the case of a high step response use, it may be in the range of 13 to 15 µm.

In addition, the conductive layer according to the present invention can secure high adhesion to the flexible printed circuit board (FPCB) coverlay, and for example, it may be 1.0 kgf/cm or more. In addition, the flexibility of the conductive layer may exhibit the same flexibility as that of a conventional flexible copper clad laminate (FCCL). In addition, the electromagnetic wave shielding power of the conductive layer may be 50 dB or more, preferably 55 to 65 dB.

According to a preferred example of the present invention, the electromagnetic wave shielding film 100 may further include a release film 40 on the insulating layer 10 and the conductive adhesive layer, respectively.

As the release film, a conventional plastic film known in the art may be used without limitation, and a release film may also be used.

Examples of plastic films that can be used include polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, polyethylene films, polypropylene films, cellophane, diacetylcellulose films, triacetylcellulose films, and acetylcellulose. Butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film , Polyethersulfone film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic resin film, norbornene resin film, cycloolefin resin film, and the like. These plastic films may be transparent or semitransparent, may be colored, or may be non-colored, and may be appropriately selected depending on the application.

In the present invention, the first release film and the second release film are disposed on the insulating layer and the conductive adhesive layer, respectively. At this time, in consideration of the bonding process between the flexible printed circuit board and the electromagnetic wave shielding film, it is preferable to adjust the interlayer adhesion between the insulating layer and the first release film to be higher than the interlayer adhesion between the conductive adhesive layer and the second release film. The release force of the release film may be in the range of 50 to 500 gf/inch. For example, the release force of the first release film may be in the range of 50 to 200 gf/inch, and the release force of the second release film may be in the range of 30 to 50 gf/inch.

To this end, the first release film disposed on the insulating layer is subjected to surface treatment on one or both sides as necessary by an oxidation method or an uneven method for the purpose of improving adhesion with the insulating layer provided on the surface. can do. Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone ultraviolet irradiation treatment, and the like, and as the unevenness method, for example, sand blasting (sand blast) method, solvent treatment method, etc. are mentioned. These surface treatment methods are appropriately selected depending on the type of the base film, but in general, mat treatment and corona discharge treatment are preferred from the viewpoint of effect and operability. Alternatively, a bead may be included in the release film.

The thickness of the release film 40 is not particularly limited, and can be adjusted within a typical range known in the art. The release film may be disposed on the insulating layer and the conductive adhesive layer, respectively, wherein the thickness of the upper release film (first release film) in contact with the insulating layer may range from 50 to 75 μm, and the lower release film in contact with the conductive adhesive layer The thickness of the (second release film) may be in the range of 75 to 150 μm.

According to another example of the present invention, a release layer may be included on the release film 40 described above. When the release film is separated from the insulating layer and the conductive adhesive layer, the release layer has a function of easily separating the insulating layer and the conductive adhesive layer so that the shape can be maintained without being damaged. Here, the release layer may be a generally used film-type release material.

The component of the release agent used in the release layer is not particularly limited, and conventional components of the release agent known in the art may be used. Non-limiting examples thereof include an epoxy-based releasing agent, a releasing agent made of a fluorine resin, a silicone-based releasing agent, an alkyd resin-based releasing agent, a water-soluble polymer, and the like. The thickness of the release layer can be appropriately adjusted within a conventional range known in the art.

The method of forming the release layer is not particularly limited, and known methods such as hot pressing, hot roll lamination, extrusion lamination, application of a coating liquid, and drying may be employed.

The electromagnetic wave shielding film according to the present invention may largely have four embodiments. However, the present invention is not limited by the embodiments illustrated below, and various modifications and applications are possible as necessary.

1 is a cross-sectional view showing a first embodiment of an electromagnetic wave shielding film according to the present invention.

Here, the electromagnetic wave shielding film includes an insulating layer 10; A mesh metal layer 20 formed on one surface of the insulating layer; And a conductive adhesive layer 30 formed on the insulating layer while covering the mesh metal layer, and have a structure in which they are sequentially stacked.

2 is a cross-sectional view showing a second embodiment of an electromagnetic wave shielding film according to the present invention.

Here, the electromagnetic wave shielding film includes an insulating layer 10; A plurality of mesh metal layers 20 formed on one surface of the insulating layer; And a conductive adhesive layer 30 formed on the insulating layer while covering the plurality of mesh metal layers.

At this time, the plurality of mesh metal layers 20 are disposed to be spaced apart from each other around the conductive adhesive layer 30, and have a structure in which a plurality of metal patterns constituting each mesh metal layer correspond to each other.

3 is a cross-sectional view showing a third embodiment of the electromagnetic wave shielding film according to the present invention.

Here, the electromagnetic wave shielding film includes an insulating layer 10; A mesh metal layer 20 formed on one surface of the insulating layer; A conductive adhesive layer 30 formed on the insulating layer while covering the mesh metal layer; And a release film 40 provided on the insulating layer and the conductive adhesive layer, respectively.

4 is a cross-sectional view showing a fourth embodiment of an electromagnetic wave shielding film according to the present invention.

Here, the electromagnetic wave shielding film includes an insulating layer 10; A plurality of mesh metal layers 20 formed on one surface of the insulating layer; A conductive adhesive layer 30 formed on the insulating layer while covering the plurality of mesh metal layers; And a release film 40 provided on the insulating layer and the conductive adhesive layer, respectively.

At this time, the plurality of mesh metal layers 20 are disposed to be spaced apart from each other around the conductive adhesive layer 30, and have a structure in which a plurality of metal patterns constituting each mesh metal layer correspond to each other.

In the above-described electromagnetic wave shielding film, the shape of the metal pattern constituting the mesh metal layer may be variously illustrated as shown in FIGS. 5 to 8, but is not particularly limited thereto.

<Method of manufacturing electromagnetic shielding film>

The electromagnetic wave shielding film for forming a flexible printed circuit board according to the present invention may be manufactured by the following method. However, it is not limited only by the following manufacturing method, and the steps of each process may be modified or selectively mixed and performed as necessary.

For a preferred embodiment of the manufacturing method of the electromagnetic shielding film, (i) forming an insulating layer by coating a thermosetting resin composition for forming an insulating layer on the first surface of the first base film and drying; (ii) forming a mesh metal layer in which a predetermined pattern is formed in a mesh shape by printing an ink composition containing an electromagnetic wave shielding film on the insulating layer; (iii) forming a conductive adhesive layer by coating and drying a resin composition for forming a conductive adhesive layer including a conductive filler and a thermosetting resin on the first surface of the second base film; And (iv) laminating the first base film and the second base film, arranging so that the mesh metal layer of the first base film and the conductive adhesive layer of the second base film are in contact with each other, and then compressing through a pressing process. It can be configured.

At this time, if necessary, the step (iii) may be replaced with a step (iii-1) of forming a mesh metal layer on the first surface of the second base film and then forming a conductive adhesive layer on the formed mesh metal layer.

First, 1) an insulating layer is formed by coating and drying a resin composition for forming an insulating layer on the first surface of the first base film.

The first base film may use a conventional plastic film known in the art without limitation, and may have, for example, the same configuration as the release film described above.

Examples of organic solvents that can be used when preparing the resin composition for forming the insulating resin layer include ketones such as acetone, methyl ethyl ketone, and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate , Acetic acid esters such as carbitol acetate, carbitols such as cellosolve and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Organic solvents may be used alone or in combination of two or more.

At this time, when the resin composition for forming an insulating layer is applied on the base film, for example, a roll coater, a bar coater, a comber coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer roll coater, a gravure coater, spraying It can be carried out by applying the thermosetting resin composition on the substrate with a coater or the like, and drying at a temperature of 50 to 130 °C for 1 to 30 minutes.

It is preferable that the insulating layer formed in the above step is in a semi-cured state (B-stage).

2) A mesh-type metal layer is formed on the formed insulating layer.

As a preferred example of the step (ii) of forming the mesh-type metal layer, an ink composition containing an electromagnetic wave shielding material is printed on the insulating layer to form a mesh metal layer in which a predetermined pattern is formed in a mesh shape.

The ink composition containing the electromagnetic wave shielding material may be a silver (Ag) containing ink composition. At this time, the concentration of the electromagnetic wave shielding material, such as silver (Ag), included in the ink composition is not particularly limited, but may be in the range of 20 to 70% by weight based on 100% by weight of the total composition. In addition, the viscosity of the ink composition is not particularly limited, but may be in the range of 6,000 to 120,000 cps as an example.

The method of forming a mesh metal layer on the insulating layer by using the ink composition can be used without limitation, a conventional printing method known in the art. For example, in order to increase productivity based on a roll-to-roll process, a screen printing method ( Screen Printing), a rotary screen, a micro gravure, and a flexo printing method may be used. In particular, microgravure and pleso printing methods capable of implementing a thin thin film layer are preferred.

The thickness of the mesh metal layer formed as described above may be in the range of 100 nm to 10 μm, and preferably may be in the range of 100 nm to 1 μm.

3) A conductive adhesive layer is formed by coating and drying the composition for forming a conductive adhesive layer on the first surface of the second base film.

As for the second base film, a conventional plastic film known in the art may be used without limitation, and a release may also be used. In this case, the second base film may be the same as or different from the components of the first base film described above.

In the present invention, when the resin composition for forming the conductive adhesive layer is applied on the second base film, for example, a roll coater, a bar coater, a comber coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer roll The thermosetting resin composition may be coated on a substrate with a coater, a gravure coater, or a spray coater, and dried for 1 to 30 minutes at a temperature of 50 to 130°C.

At this time, after first forming a mesh metal layer on the second base film, a conductive adhesive layer may be formed on the formed mesh metal layer. In this case, the electromagnetic wave shielding film according to the fourth embodiment of the present invention may be formed. Here, the method or conditions for forming the mesh metal layer may be the same as in step 2) described above.

4) The first base film and the second base film are stacked, and the mesh metal layer of the first base film and the conductive adhesive layer of the second base film are placed in contact with each other, and then compressed through a pressing process.

In the present invention, the compression process conditions can be appropriately adjusted within a conventional range known in the art. For example, thermocompression Lami. Conditions during the process (roll-to-roll) are not particularly limited, but for example, ^{it may be performed under conditions of a temperature of room temperature to 130° C., a pressure of 3 to 50 kgf/cm 2} , and a compression speed of 3 m/min to 30 m/min.

At this time, the sheet-shaped first base film, the first base film in which the insulating layer and the mesh-like metal layer are sequentially stacked, and the second base film on which the conductive adhesive layer is formed may be wound in a roll shape and laminated in a continuous manner. It is okay to perform lamination after cutting both roll-shaped sheets.

After the above step, the above-described electromagnetic wave shielding film may be slit to a suitable size and used.

The electromagnetic wave shielding film of the present invention manufactured as described above may have a structure as shown in FIG. 1 below.

In the present invention, the above-described electromagnetic wave shielding film may be laminated on top of a coverlay of a printed circuit board, preferably a flexible printed circuit board (FPCB), and then bonded to be used.

At this time, bonding of the flexible printed circuit board and the electromagnetic wave shielding film may be performed by a conventional method known in the art. As an example, it may be bonded with an adhesive, or can be bonded in a non-adhesive form without using an adhesive.

As a preferred embodiment of the manufacturing process of the EMI shielding film for the flexible printed circuit board, (I) the electromagnetic wave shielding film is laminated on the coverlay of the flexible printed circuit board, but after removing the first base film provided on the side of the conductive adhesive layer Laminating the exposed conductive adhesive layer on top of a coverlay of a flexible printed circuit board and thermally compressing it; And (II) removing the second base film positioned on the top of the compressed material.

The flexible printed circuit board may be a flexible circuit board (FPCB) with a coverlay attached, and for example, a copper foil layer and a coverlay may be sequentially stacked on polyimide (PI). In the present invention, the printed circuit board refers to a printed circuit board laminated in a single layer or two to three or more layers by a plating through hole method or a build-up method, and may be a single-sided type or a double-sided type.

In addition, the conditions during the thermocompression bonding process are not particularly limited, but ^{may be performed under conditions of a temperature of 150 to 170° C., a pressure of 30 to 80 kgf/cm 2} , and 30 to 60 minutes, for example.

In the present invention, excellent electromagnetic wave shielding properties can be exhibited by bonding the electromagnetic wave shielding film on the flexible printed circuit board as described above.

Hereinafter, the present invention will be described in detail through examples, but the following examples and experimental examples are only illustrative of one aspect of the present invention, and the scope of the present invention is not limited by the following examples and experimental examples.

[Example 1]

1-1. Insulation layer coating solution manufacturing

Halogen flame-retardant epoxy resin produced by thermosetting resin (Kukdo Chemical KDP555) 9.1% by weight, bisphenol A type epoxy resin (Dow DER383) 8.1% by weight, low-dielectric epoxy resin (Nippon XD1000) 3.5% by weight, bisphenol novolac epoxy resin (Kukdo Chemical KPBN110) 6.1 wt%, carbon black (Columbian Chemicals) 0.9 wt%, phosphorus flame retardant (Otsuka Chemical SPB-100) 4.8 wt%, rubber as a thermoplastic resin (Kumho Petrochemical KNB 40H) 24.2 wt%, polyvinyl butyral Insulation by mixing and dissolving 12.1% by weight of resin (Unochem KS23Z), 10.7% by weight of dicyanamide as a latent curing agent, 0.6% by weight of an imidazole derivative (Ildong Chemical 2E4MZ) as a catalytic curing agent, and 9.8% by weight of methylcellosolve as a solvent A layer coating solution was prepared.

1-2. Manufacture of silver (Ag) nano coating solution for mesh formation

Silver nanoparticles 55 wt%, bisphenol A epoxy resin (hexion EPIKOTE1009, equivalent 1,000) 7 wt% catalytic curing agent 2.8 wt% imidazole derivative, mixed ether solvent (methoxy benzene and propylene glycol monomethyl ether acetate Solvent mixed in a ratio of 7:3 weight) 32.2% by weight and 3% by weight of a phosphoric acid ester compound (BYK BYK-111) as a dispersant are first mixed with a high-viscosity mixer, and then secondarily mixed and dispersed through a 3 main mill to mesh. Forming ink was prepared.

1-3. Manufacture of coating solution for forming conductive adhesive layer

Halogen flame-retardant epoxy resin (Kukdo Chemical KDP555) 5.5% by weight, bisphenol A type epoxy resin (Dow DER383) 4.9% by weight, low dielectric epoxy resin (Nippon XD1000) 2.1% by weight, bisphenol novolac epoxy resin (Kukdo Chemical) Chemical KPBN110) 3.6% by weight, Dendrite-shaped powder coated with silver on copper as a conductive filler (GGP Corporation CuAg10 CHL5 UF) 48.6% by weight, as a thermoplastic resin rubber (KNB 40H) 21.9% by weight, as a latent hardener Dicyanamide 6.4 wt%, an imidazole derivative (Ildong Chemical 2E4MZ) 0.3 wt% as a catalytic curing agent, and propylene glycol monomethyl ether acetate 4.9 wt% as a solvent were mixed and dissolved to prepare a conductive layer coating solution.

1-4. Electromagnetic shielding film manufacturing

The insulating layer coating composition prepared in 1-1 was formed on the first surface of the prepared first base film by forming an insulating layer with a micrograia coating, and dried at 130° C. for 3 minutes and 30 seconds to obtain a semi-cured state of 5 to 6 μm. An insulating layer of was formed.

Then, the conductive adhesive layer coating composition prepared in 1-3 on the first side of the prepared second base film was formed with a comma coating to form a conductive adhesive layer and dried at 130° C. for 3 minutes and 30 seconds to conduct conductivity in a semi-cured state of 14 to 15 μm. An adhesive layer was formed.

On the insulating layer formed on the first base film, a mesh metal layer having a line width of 50 μm and an opening area of 30% was formed by flexo printing, and cured at 150° C. for 5 minutes. Thereafter, the mesh-formed surface of the insulating layer and the conductive adhesive layer were placed in contact with each other, and then compressed through a heating and pressing process to prepare an electromagnetic wave shielding film for a flexible printed circuit board.

[Example 2]

The metal mesh layer formed in Example 1 was formed with a mesh having an opening area of 50% from a line width of 50 µm to a line width of 80 µm, and after curing, arranged so as to be in contact with the conductive adhesive layer, and pressed through a heating and pressing process. An electromagnetic wave shielding film for a flexible printed circuit board was prepared.

[Example 3]

The metal mesh layer formed in Example 1 was formed with a mesh having an opening area of 15% from a line width of 50 µm to a line width of 150 µm, and then cured, arranged so as to be in contact with the conductive adhesive layer, and pressed through a heating and pressing process. An electromagnetic wave shielding film for a flexible printed circuit board was prepared.

[Example 4]

The insulating layer coating composition prepared in Example 1-1 was formed on the first surface of the prepared first base film by forming an insulating layer with a micro graia coating, and dried at 130° C. for 3 minutes and 30 seconds to a radius of 5 to 6 μm. An insulating layer in a converted state was formed.

Thereafter, as in Example 1, a mesh metal layer having an opening area of 70% was formed and cured with a line width of 50 μm on the insulating layer formed on the first base film. After forming a mesh layer having an opening area of 30 μm and 70% on the first surface of the prepared second base film, a conductive adhesive layer was formed as in Example 1. Subsequently, the mesh metal layer on the first base film and the conductive adhesive layer of the second base film were placed in contact with each other, and then pressed through a heating and pressing process to prepare an electromagnetic wave shielding film for a flexible printed circuit board of Example 4 (FIG. 4) Reference).

[Example 5]

An electromagnetic wave shielding film for a flexible printed circuit board was manufactured by performing the same method as in Example 4, except that the opening area of the metal mesh layer formed on the second base film was changed from 70% to 85%.

More specifically, in Example 1, a mesh layer having an opening area of 70% was formed in the metal mesh layer with a line width of 50 μm. In addition, a mesh layer having an opening area of 30 μm and 85% was formed on the first surface of the prepared second base film, and then a conductive adhesive layer was formed as in Example 1. Subsequently, the mesh metal layer on the first base film and the conductive adhesive layer of the second base film were placed in contact with each other, and then pressed through a heating and pressing process to prepare an electromagnetic wave shielding film for a flexible printed circuit board of Example 5 (FIG. 4) Reference).

[Comparative Example 1]

An electromagnetic wave shielding film for a flexible printed circuit board was manufactured according to the same method as in Example 1, except that the mesh-type metal layer was not formed.

More specifically, the insulating layer formed on the first base film and the conductive adhesive layer formed on the second base film were arranged to contact each other, and then pressed through a heating and pressing process under conditions of 80°C and 10kgf/cm to shield electromagnetic waves of Comparative Example 1. The film was prepared.

[Comparative Example 2]

An electromagnetic wave shielding film for a flexible printed circuit board was manufactured in the same manner as in Example 4, except that the mesh-type metal layer was not formed.

More specifically, the insulating layer formed on the first base film and the conductive adhesive layer formed on the second base film were arranged to contact each other, and then pressed through a heating and pressing process under conditions of 80°C and 10kgf/cm to shield electromagnetic waves of Comparative Example 1. The film was prepared.

[Evaluation example] Evaluation of electromagnetic wave shielding film

Each of the following physical property evaluations was performed using the electromagnetic wave shielding films prepared in Examples 1 to 5 and Comparative Examples 1 to 2, respectively, and the results are shown in Table 1 below.

1) adhesion

After the prepared second base film was removed, a 50µm PI Film (SKC Kolon) was placed in contact with the conductive adhesive layer, and after laminating at 80~100℃, the upper first base film was removed.

To form the support layer of the laminated adhesion evaluation coupon, a bonding sheet and a prepreg impregnated with a glass fiber matrix are laminated under the 50㎛ PI film, and a bonding sheet and a 25㎛ PI film (SKC) on the upper insulating layer. Kolon) was laminated and then subjected to a compression process at 150° C. for 60 minutes under a pressure of 35 kgf per unit area to completely cure the insulating layer and the conductive adhesive layer.

The fully cured coupon was measured for 90 degree (vertical) adhesion (kgf/cm) to the PI film at a tensile speed of 50 mm/min.

2) Heat resistance (Solder Deeping)

After removing the second base film of the prepared electromagnetic shielding film, place the 25㎛ PI film (SKC Kolon) in contact with the conductive adhesive layer, and then press the insulating layer and the conductive adhesive layer at 150℃ for 60 minutes under a pressure of 35kgf per unit area. It was completely cured and the upper first base film was removed.

The electromagnetic shielding film from which the upper first base film was removed was immersed in a solder bath at 300° C. for 10 seconds to observe appearance defects such as lifting and cracking of the electromagnetic shielding film and color change of the insulating layer. At this time, the case where appearance defects such as lift and crack occurred was judged as NG, and the case where there was no appearance defect such as lift and crack was judged as Pass.

3) Insulation layer chemical resistance evaluation:

Heat resistance evaluation coupons were produced by lamination and compression processes in the same manner as in the coupon production method, and the upper first base film was removed. An electromagnetic wave shielding film from which the upper first base film was removed was immersed in HCl (2 mol/L) aqueous solution for 10 minutes to prepare a coupon.

The electromagnetic wave shielding film from which the upper first base film was removed _{was immersed in HCl (3%), H 2} SO ₄ (5%, NaOH (5%) aqueous solution for 30 minutes each step to prepare coupons. The immersed evaluation coupon was evaluated for chemical resistance of the insulating layer in accordance with ASTM D 3359. The evaluation method and criteria are shown in Fig. 10.

4) Pencil hardness

The hardness of the coating film was measured using the strength of graphite, which is a core material of a pencil. First, the upper first base film was removed by producing a coupon by lamination and pressing process in the same manner as the method of producing a coupon for evaluating heat resistance.

The pencil was sharpened according to the strength of the lead, and the bottom of the core was rubbed with fine sand paper to make it flat. Thereafter, it was determined based on peeling or scratching of the insulating layer by pushing the pencil three times with a weight of 500 g so that the pencil lead touches the surface of the insulating layer of the electromagnetic wave shielding film from which the upper first base film has been removed at an angle of 45 degrees.

5) Electromagnetic shielding rate evaluation

Heat resistance evaluation coupons were produced by lamination and compression processes in the same manner as in the coupon production method, and the upper first base film was removed. From the removed electromagnetic shielding film, a coupon having a shape as shown in FIG. 9 was prepared, and the electromagnetic shielding rate for a frequency range of 30 MHz to 1 GHz was measured according to ASTM 4935-1. At this time, the tester used an Agilent 8719C Network Analyzer.

6) Contact resistance measurement

Two inner-layer circuits were formed on the prepared cross-section FCCL with a width of 5 mm and a length of 50 mm and an interval of 10 mm between circuits.

PI Film 12.5㎛, 15㎛ adhesive layer coverlay in the center of the inner layer circuit, 0.15mm diameter circle and 5mm × 5mm square at the end of the inner layer circuit. After punching, temporary bonding to the inner layer circuit and 35kgf per unit area A thermocompression process was performed at 150° C. for 60 minutes. After the thermocompression bonding process, electroless gold plating was performed on the inner layer circuit exposed to copper in sizes of 0.15mm and 5mm×5mm by a punched coverlay.

After removing the second base film of the prepared electromagnetic wave shielding film, cut and laminate the electromagnetic wave shielding film with a width of 10 mm in a 0.15 mm area located in the center of the inner layer circuit, and heat-compressed at 150°C for 60 minutes at 35 kgf per unit area, and then 5 mm × The contact resistance of the two inner layer circuits exposed to a size of 5 mm was measured.

Adhesion Heat resistance
(Solder) Chemical resistance
(Cross cut) pencil
Hardness Shielding rate
(dB) contact
Resistance(Ω) Comparative Example 1 ≥ 1.2 Pass 5B 1H 45~46 0.3 Example 1 ≥ 1.2 Pass 5B 1H 54~55 0.2 Example 2 ≥ 1.2 Pass 5B 1H 59~60 0.1 Example 3 ≥ 1.2 Pass 5B 1H 61~62 0.1 Example 4 0.8 Pass 5B 1H 60~61 0.1 Example 5 1.1 Pass 5B 1H 59~60 0.1 Comparative Example 2 ≥ 1.2 Pass 5B 1H 38~39 1.3

As a result of the experiment, it was confirmed that the electromagnetic wave shielding film according to the present invention exhibits excellent electron shielding rate, adhesion, heat resistance, chemical resistance, and adhesion resistance at the same time, even if it includes a mesh-type metal layer.

Claims (21)

Insulating layer;
A first mesh metal layer formed on one surface of the insulating layer and including a plurality of metal patterns in a mesh shape;
A conductive adhesive layer formed on one surface of the insulating layer while covering the first mesh metal layer, and including a conductive filler and a resin; And
A second mesh metal layer formed on a surface of the conductive adhesive layer opposite to the surface on which the first mesh metal layer is formed, and comprising a plurality of metal patterns in a mesh shape; and
The first mesh metal layer has an average line width of 50 to 500 μm and an opening area ratio of less than 50%,
The second mesh metal layer has an average line width smaller than that of the first mesh metal layer and a high opening area ratio, an electromagnetic wave shielding film for a flexible printed circuit board (FPCB). The method of claim 1,
The electromagnetic wave shielding film for a flexible printed circuit board, characterized in that the pattern of the first mesh metal layer or the second mesh metal layer has a shape selected from the group consisting of a circular shape, a diagonal shape, a triangular or more polygonal shape, and an amorphous shape. delete The method of claim 1,
A conductive adhesive layer is provided between the first mesh metal layer and the second mesh metal layer, and the first mesh metal layer and the second mesh metal layer spaced apart from each other around the conductive adhesive layer are arranged so that a plurality of metal patterns correspond to or cross each other. Electromagnetic wave shielding film for a flexible printed circuit board, characterized in that the. The method of claim 1,
The average line width of the first mesh metal layer in contact with the insulating layer and positioned above the conductive adhesive layer is in the range of 50 to 500 μm,
An electromagnetic wave shielding film for a flexible printed circuit board, characterized in that the average line width of the second mesh metal layer positioned under the conductive adhesive layer is in the range of 20 to 50 μm. The method of claim 1,
An electromagnetic wave shielding film for a flexible printed circuit board, characterized in that the ratio of the opening area of the first mesh metal layer is less than 50%, and the ratio of the opening area of the second mesh metal layer is 50% or more. The method of claim 1,
The first mesh metal layer or the second mesh metal layer is made of at least one conductive metal material selected from the group consisting of silver (Ag), gold (Au), copper (Cu), and aluminum (Al). Electromagnetic shielding film for printed circuit boards. The method of claim 1,
The electromagnetic wave shielding film for a flexible printed circuit board, characterized in that the thickness of the first mesh metal layer or the second mesh metal layer is in the range of 0.1 to 10 μm. The method of claim 1,
The insulating layer is an electromagnetic wave shielding film for a flexible printed circuit board, characterized in that comprising a thermosetting resin. The method of claim 1,
The insulating layer is an electromagnetic wave shielding film for a flexible printed circuit board, characterized in that it comprises 0.5 to 5 parts by weight of an electrically non-conductive filler based on 100 parts by weight of the insulating layer. The method of claim 1,
Electromagnetic shielding film for a flexible printed circuit board, characterized in that the thickness of the insulating layer is in the range of 5 to 20 ㎛. The method of claim 1,
The conductive filler of the conductive adhesive layer is a copper filler coated with Ag, Cu, Ni, Al, Ag, a nickel filler, or a polymer filler. The method of claim 1,
The content of the conductive filler is in the range of 30 to 70 parts by weight based on 100 parts by weight of the conductive adhesive layer. The method of claim 1,
Electromagnetic shielding film for a flexible printed circuit board, characterized in that the resin of the conductive adhesive layer is a thermosetting resin. The method of claim 1,
A total thickness of the first mesh metal layer, the second mesh metal layer and the conductive adhesive layer is in the range of 3 to 5 ㎛ or 13 to 15 ㎛ range, the electromagnetic wave shielding film for a flexible printed circuit board. The method of claim 1,
Electromagnetic wave shielding film for a flexible printed circuit board, characterized in that it further comprises a release film on each of the insulating layer and the conductive adhesive layer. The method of claim 16,
The release film disposed on the side of the insulating layer is a matte treatment, a corona treatment, or an electromagnetic wave shielding film for a flexible printed circuit board, characterized in that it includes a bead therein. (i) forming an insulating layer by coating and drying a thermosetting resin composition for forming an insulating layer on the first surface of the first base film;
(ii) forming a first mesh metal layer in which a predetermined pattern is formed in a mesh shape by printing an ink composition containing an electromagnetic wave shielding film on the insulating layer;
(iii) After forming a second mesh metal layer on the first side of the second base film, coating a resin composition for forming a conductive adhesive layer including a conductive filler and a thermosetting resin on the formed second mesh metal layer, and drying Forming an adhesive layer; And
(iv) laminating the first base film and the second base film, placing the first mesh metal layer of the first base film and the conductive adhesive layer of the second base film in contact with each other, and then compressing through a pressing process ;
Including, the method of manufacturing an electromagnetic wave shielding film for forming a flexible printed circuit board according to claim 1. The method of claim 18,
The method of manufacturing an electromagnetic wave shielding film, characterized in that the insulating layer formed in step (i) is in a semi-cured state (B-stage). The method of claim 18,
In the step (ii), the first mesh metal layer is formed by a method selected from the group consisting of a screen printing method, a rotary screen, a microgravure, and a flexo method. delete

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