KR102428884B1 - Reinforcing film for ground and composite printed circuit board for shielding electromagenetic wave comprising the same - Google Patents

Abstract

The present invention relates to a ground reinforcement film usable for electrical, electronic and communication devices, and an electromagnetic wave shielding composite substrate including the same, wherein the ground reinforcement film includes: a first metal layer having a plurality of protrusions on one surface; an adhesive layer covering one surface of the first metal layer; and a second metal layer formed on the other surface of the first metal layer, wherein at least some of the plurality of protrusions are in contact with the surface of the adhesive layer.

Description

Ground reinforcement film and electromagnetic wave shielding composite board including the same

The present invention relates to a ground reinforcement film usable in electrical, electronic and communication devices, and an electromagnetic wave shielding composite substrate including the same.

With the advent of the 5G era of information and communication, the need to prevent unnecessary radiation from high-speed electrical signals or electromagnetic noise from internal and external sources is gradually increasing due to the demand for high-speed transmission of data. is rising In order to offset the noise of the high-speed signal, the printed circuit board needs not only the application of the electromagnetic wave shielding film but also the expansion of the ground wiring. As a result, the area of the electromagnetic wave shielding type printed circuit board increases, resulting in a problem in that the circuit design is limited. In addition, the manufacturing process of the printed circuit board is complicated and the cost is high.

A conventional electromagnetic wave shielding printed circuit board is printed by disposing a ground wiring pattern inside the board, forming a through hole to expose the ground wiring pattern, and then contacting the conductive adhesive of the electromagnetic wave shielding film with the through hole. It served to shield and ground the noise generated from the circuit board. As a high-speed signal corresponding to 5G in the above-described printed circuit board is applied, it is necessary to shield high-frequency noise and at the same time increase or additionally arrange a ground wire for impedance matching. In this case, not only the degree of freedom of design is low, but also the manufacturing process is complicated and the cost is high, and there is a problem in lightening and thinning the printed circuit board.

The technology underlying the present invention is disclosed in Japanese Patent Laid-Open No. 2007-294996.

The present invention has been devised to solve the above-described problems, and intends to apply a ground reinforcement film in which a first metal layer (eg, a copper foil layer) having a high surface roughness is disposed on one surface.

Specifically, when the above-described ground reinforcement film and the electromagnetic wave shielding film are pressed in close contact, the high illuminance portion of the first metal layer penetrates the insulating layer of the electromagnetic wave shielding film and comes into direct contact with the conductive layer located thereunder. , it was conceived that the connection of electrical signals can be induced through the connection structure between the ground wiring pattern and the conductive layer of the electromagnetic wave shielding film. In addition, the present invention increases the shielding efficiency of noise by selectively mounting in a specific area requiring additional wiring of the ground circuit for noise cancellation and impedance matching, and additionally wiring the ground circuit by contacting the metal case connected to the ground circuit. effect can be induced.

Accordingly, in the present invention, a ground reinforcement film capable of exhibiting a high degree of freedom in design, simplification of a manufacturing process, and cost reduction through electrical connection using a high surface roughness of the electrically conductive metal layer provided in the ground reinforcement film, and electromagnetic wave shielding including the same It is a technical task to provide a type composite board.

In order to achieve the above technical problem, the present invention is a first metal layer having a plurality of protrusions on one surface; an adhesive layer covering one surface of the first metal layer; and a second metal layer formed on the other surface of the first metal layer, wherein at least some of the plurality of protrusions are in contact with the surface of the adhesive layer.

According to one embodiment of the present invention, the first metal layer and the plurality of protrusions may be integrally formed.

According to one embodiment of the present invention, the surface roughness (Rz) of the one surface having the plurality of protrusions may be 2 to 35㎛.

According to one embodiment of the present invention, the ratio (R1/R2) between the surface roughness R1 of one surface and the surface roughness R2 of the other surface in the first metal layer may be 1 to 350.

According to an embodiment of the present invention, the first metal layer is copper (Cu), and the second metal layer is aluminum (Al), chromium (Cr), titanium (Ti), silver (Ag), gold (Au), A metal selected from the group consisting of tungsten (W), molybdenum (Mo), tantalum (Ta), niobium (Nb), nickel (Ni), palladium (Pd), cobalt (Co), and zinc (Zn), or a metal thereof It may be one or more alloys.

According to one embodiment of the present invention, the outermost layer of the second metal layer may be made of gold (Au).

According to one embodiment of the present invention, the thickness of the first metal layer may be 5 to 35 μm, and the thickness of the second metal layer may be 0.01 to 5 μm.

According to one embodiment of the present invention, the adhesive layer may be a resin layer that does not include conductive particles.

According to one embodiment of the present invention, the adhesive layer may include at least one of a thermoplastic resin and a thermosetting resin having a glass transition temperature (Tg) of -60 to 140 °C.

According to one embodiment of the present invention, the thermosetting resin may be at least one selected from the group consisting of an epoxy resin, a phenol resin, a melamine resin, a silicone resin, a urethane resin, and a urea resin.

According to one embodiment of the present invention, the thermoplastic resin may be at least one selected from the group consisting of an olefin resin, an acrylic resin, and rubber.

According to an embodiment of the present invention, a first base layer disposed on one surface of the adhesive layer; and a second base layer disposed on one surface of the second metal layer. It may further include at least one of.

According to one embodiment of the present invention, the first base layer may be any one of a release paper and a release polymer film.

According to one embodiment of the present invention, the second base layer may be at least one of a polyimide (PI) film, a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, an adhesive film, a protective film, and a carrier film. have.

According to one embodiment of the present invention, the thickness of the first base layer and the second base layer may be 10 to 150㎛, respectively.

In addition, the present invention is a printed circuit board having a ground; an electromagnetic wave shielding film disposed on one surface of the printed circuit board and including an insulating layer and a conductive layer; and a ground reinforcement film disposed on the electromagnetic wave shielding film, wherein at least some of the plurality of protrusions of the ground reinforcement film penetrate the insulating layer of the electromagnetic wave shielding film to be electrically connected to the conductive layer, and the conductive layer provides an electromagnetic wave shielding type composite board connected to the ground of the printed circuit board.

According to one embodiment of the present invention, the insulating layer of the electromagnetic wave shielding film may be a resin layer that does not include a conductive filler.

In the present invention, by mounting a ground reinforcement film in which a first metal layer (eg, copper foil layer) having a high surface roughness portion is disposed on one surface of a printed circuit board to which an electromagnetic wave shielding film (EMI shielding film) is attached, the degree of freedom in design is secured can do.

In addition, it is possible to reduce the size and thickness of the printed circuit board, as well as add a high shielding effect to the mounting portion of the ground reinforcement film. In addition, it is possible to easily configure a ground connection at a desired location.

In addition, in the present invention, a separate process such as formation of a through-hole or use of a conductive adhesive is unnecessary, and since the ground in the printed circuit board is not exposed or additionally wired, the manufacturing process can be simplified and the processing cost can be reduced.

1 is a view schematically showing a side view and a partially enlarged cross section of a ground reinforcement film according to an embodiment of the present invention.
2 is a view schematically showing a cross-section of a ground reinforcement film according to a first embodiment of the present invention.
3 is a view schematically showing a cross-section of a ground reinforcement film according to a second embodiment of the present invention.
4 is a view schematically showing a cross-section of a ground reinforcement film according to a third embodiment of the present invention.
5 is a view schematically showing a cross-section of a ground reinforcement film according to a fourth embodiment of the present invention.
6 is a cross-sectional view of an electromagnetic wave shielding type composite substrate including a ground reinforcement film according to an embodiment of the present invention.
7 is an SEM photograph of the first surface (surface roughness portion) and the second surface of the first metal layer used in the ground reinforcement film of Example 1. FIG.
8 is an AFM topography of the first metal layer (copper foil thickness: 12 μm) used in the ground reinforcement film of the present invention.
9 is an AFM topography of the first metal layer (copper foil thickness: 18 μm) used in the ground reinforcement film of the present invention.
10 is a plan view (a) and a cross-sectional view (b) of a resistance measuring specimen used in a method of measuring the resistance of an electromagnetic wave shielding type composite substrate according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, this is presented as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

In addition, throughout the specification, when a part is 'connected' with another part, this includes not only the case of 'directly connected' but also the case of 'indirectly connected' with another element interposed therebetween. do. Also, 'including' a certain component means that other components may be further included, rather than excluding other components, unless otherwise stated.

An object of the present invention is to develop a ground reinforcing film of a novel structure that can easily connect the ground and increase reliability by using the high surface roughness of the electrically conductive metal layer provided in the ground reinforcing film.

Specifically, when a ground reinforcement film provided with a metal layer (eg, copper foil) having high surface roughness is mounted on an electromagnetic wave shielding film or a printed circuit board to which an electromagnetic wave shielding film is attached and subjected to a heating/pressurization process, the ground reinforcement film At least a portion of the plurality of protrusions indicating the high surface roughness portion penetrates the insulating layer of the electromagnetic wave shielding film and comes into direct contact with the conductive particles in the conductive layer, thereby conducting electricity. Accordingly, it is possible to easily perform the ground connection of the electromagnetic wave shielding film at a desired location without using additional processes or materials, thereby providing a degree of freedom of the circuit. In addition, since the ground in the printed circuit board is not exposed or additionally wired, it is easy to make the printed circuit board lighter and thinner, and it is possible to reduce the processing cost. In addition, the above-described ground reinforcement film may further add an electromagnetic wave shielding effect by providing impedance control.

<Ground reinforcement film>

According to one embodiment of the present invention, a first metal layer having a high surface roughness portion on one surface; and a ground reinforcement film in which a resin adhesive layer and a second metal layer are disposed on both sides of the first metal layer, respectively.

1 to 5 schematically show a cross-sectional structure of a ground reinforcement film according to an embodiment of the present invention.

1 and 2, the ground reinforcement film 100A according to the first embodiment of the present invention includes a first metal layer 10 having a plurality of protrusions 11 on one surface; an adhesive layer 20 covering one surface of the first metal layer 10; and a second metal layer 30 formed on the other surface of the first metal layer 10, wherein at least a portion of the plurality of protrusions is in contact with the surface of the adhesive layer.

first metal layer

In the ground reinforcement film 100A according to the present invention, the first metal layer 10 is laminated on the electromagnetic wave shielding type composite substrate to serve as an electrical conductor to enable ground connection.

The first metal layer 10 has a plurality of protrusions 11 on one surface and a flat surface on the other surface. At least some of the plurality of protrusions 11 pass through an insulating layer of an electromagnetic wave shielding film (EMI shielding film) to be described later and conduct electricity with a conductive layer located thereunder. The shape, size, and number of are not particularly limited. For example, the surface roughness (surface roughness, Rz) of one surface having the plurality of protrusions 11 in the first metal layer 10 may be 2 to 35 μm, preferably 6 to 12 μm.

Since the first metal layer 10 has a high surface roughness (R ₁ ) on one surface and a substantially flat surface (R ₂ ) on the other surface, a high surface roughness difference between both surfaces may be exhibited. According to one embodiment, the ratio (R1/R2) between the surface roughness (R1) of one surface and the surface roughness (R2) of the other surface in the first metal layer 10 may be 1 to 350, preferably 3 to 120 days can

The plurality of protrusions 11 positioned on the first metal layer 10 are covered with an adhesive layer 20 . The plurality of protrusions 11 are spaced apart from each other and distributed, and some of them are in contact with the outermost surface of the adhesive layer 20 . The height of the protrusion 11 is not particularly limited, and for example, may be substantially the same as the thickness of the adhesive layer 20 . For example, at least some of the plurality of protrusions 11 protrude to the outside of the adhesive layer 20, and at least some of the other protrusions 11 may have a height equal to or smaller than the thickness of the adhesive layer 20. have.

In the present invention, the shape, size and number of the plurality of protrusions 11 are not particularly limited. For example, the cross-sectional shape of the plurality of protrusions 11 may be a triangular shape, a convex shape, or a mountain shape. In addition, the first metal layer 10 and the plurality of protrusions 11 may be integrally formed, or the plurality of protrusions 11 may be separately attached to one surface of the first metal layer 10 . When the plurality of protrusions 11 are separately attached to one surface of the first metal layer 10 as described above, the first metal layer 10 and the plurality of protrusions 11 may be composed of different electrically conductive conductor components.

The component of the first metal layer 10 is not particularly limited, and a conventional electrically conductive conductor material known in the art may be used. For example, it may be formed of a conductive metal such as copper, tin-plated copper, nickel-plated copper, or an alloy thereof. As the conductor, a foil-shaped conductive metal is preferable, and copper foil (Cu) is more preferable. The copper foil may be used without particular limitation as long as it is a copper foil formed through a conventional copper foil forming method known in the art, such as a rolling method and an electrolytic method. Preferably, it may be an electrodeposited copper foil. In this case, in order to prevent the surface of the copper foil from being oxidized and corroded, it may be a rust preventive treatment. However, when the copper foil is manufactured, one side of both surfaces is adjusted to have the above-mentioned high surface roughness.

The thickness of the first metal layer 10 is not particularly limited, and may be appropriately adjusted within a typical range known in the art. For example, in consideration of reduction in thickness and lightness of the electromagnetic wave shielding type composite substrate, the thickness of the first metal layer 10 may be 5 to 35 μm, preferably 9 to 20 μm.

second metal layer

In the ground reinforcement film 100A according to the present invention, the second metal layer 30 serves to reinforce the ground effect and protect the first metal layer 10 .

The second metal layer 30 may be made of a conventional metal known in the art or an alloy thereof. For example, the second metal layer 30 may include aluminum (Al), chromium (Cr), titanium (Ti), silver (Ag), gold (Au), tungsten (W), molybdenum (Mo), tantalum (Ta), one metal selected from the group consisting of niobium (Nb), nickel (Ni), palladium (Pd), cobalt (Co), and zinc (Zn); Or it may be an alloy (alloy) containing at least two or more thereof. Specifically, the second metal layer 30 is one type of metal material such as aluminum (Al), chromium (Cr), titanium (Ti), silver (Ag), gold (Au), tungsten (W), or contains nickel It may be an alloy. A component included in the nickel-containing alloy may be at least one selected from palladium (Pd), chromium (Cr), cobalt (Co), and zinc (Zn).

The second metal layer 30 may have a single layer or a multilayer structure of at least two or more layers. According to this embodiment, the outermost layer of the second metal layer is preferably made of gold (Au). The thickness of the second metal layer 30 is not particularly limited, and may be, for example, 0.01 to 5 μm, preferably 0.02 to 2 μm.

The second metal layer 30 may be manufactured according to a conventional method known in the art, and is not particularly limited. As an example, deposition (sputtering method) or plating method may be applied.

adhesive layer

In the ground reinforcement film 100A according to the present invention, the adhesive layer 20 serves to firmly bond the ground reinforcement film and the electromagnetic wave shielding type composite substrate to be described later in close contact, and at the same time, a first metal layer ( 10) functions to surround and protect the plurality of protrusions 11 .

Since the adhesive layer 20 has a plurality of protrusions 11 therein, when it includes conductive particles, the surface roughness of the first metal layer 10 , specifically, the height of the protrusions 11 , or the first metal layer may affect electrical connections. Accordingly, the adhesive layer 20 is preferably a resin layer that does not include conductive particles.

The adhesive layer 20 may include at least one of a conventional thermosetting resin and a thermoplastic resin known in the art. For example, the adhesive layer 20 may include at least one selected from the group consisting of a thermoplastic resin and a thermosetting resin having a glass transition temperature (Tg) of -60 to 140°C.

Non-limiting examples of usable thermosetting resins include epoxy resins, polyurethane resins, alkyd resins, phenolic resins, melamine resins, silicone resins, urea resins, vegetable oil-modified phenolic resins, xylene resins, guanamine resins, diallyl phthalate resins , vinyl ester resin, unsaturated polyester resin, furan resin, polyimide resin, cyanate resin, maleimide resin, and may be at least one selected from the group consisting of benzocyclobutene resin. Specifically, the thermosetting resin may be at least one selected from the group consisting of an epoxy resin, a phenol resin, a melamine resin, a silicone resin, a urethane resin, and a urea resin.

As the epoxy resin, conventional epoxy resins known in the art may be used without limitation, and it is preferable that two or more epoxy groups are present while not including a halogen element in one molecule. Non-limiting examples of usable epoxy resins include bisphenol A type / F type / S type resin, novolak type epoxy resin, 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 novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol S novolak type epoxy resin, biphenyl novolak type epoxy resin, naphthol novolak type epoxy resin, naphthol phenol coaxial novolak type epoxy resin , naphthol choresol coaxial 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 Aral Kill-type epoxy resins, polyfunctional phenol resins, naphthol aralkyl-type epoxy resins, and the like. At this time, the above-mentioned epoxy resin may be used alone or two or more kinds may be mixed.

In addition, non-limiting examples of the thermoplastic resin that can be used include an olefin resin, an acrylic resin, a rubber, or a mixture thereof. Specific examples include polyethylene, polypropylene, polystyrene, polyimide, Teflon (PTFE), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene-styrene rubber (ABS), carr Voxy-terminated butadiene acrylonitrile rubber (CTBN), polybutadiene, styrene-butadiene-ethylene resin (SEBS), acrylic acid containing a side chain having 1 to 8 carbon atoms ) and/or methacrylic acid ester resin (acrylic rubber), or a mixture of one or more thereof.

It is preferable that the above-mentioned thermoplastic resin contains the functional group which can react with the epoxy resin which is a thermosetting resin. Specifically, it is at least one functional group selected from the group consisting of an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a methoxy group, and an isocyanate group. Since these functional groups form a strong bond with the epoxy resin, heat resistance after curing is improved, which is preferable. In particular, in the present invention, it is more preferable to use an acrylonitrile-butadiene copolymer (NBR) in consideration of adhesiveness, flexibility, and thermal stress relief. It is preferable that such a copolymer contains the functional group which can react with an epoxy resin. Specific examples of the functional group include an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a methoxy group, an isocyanate group, a vinyl group, a silanol group, etc., and particularly preferably a carboxyl group. Specific examples of the NBR having a carboxyl group include PNR-1H (manufactured by JSR Co., Ltd.), Nipol 1072J, and Nipol DN631 (manufactured by Nippon Zeon Co., Ltd.).

The thickness of the adhesive layer 20 is not particularly limited, and may be substantially the same as the average height of the plurality of protrusions 11 positioned on one surface of the first metal layer 20 described above. For example, it may be 2 to 35 μm, preferably 6 to 12 μm.

Hereinafter, the ground reinforcement film 100B according to the second embodiment of the present invention shown in FIG. 3 will be described. In Fig. 3, the same reference numerals as in Fig. 2 denote the same members.

Hereinafter, in the description of FIG. 3 , content overlapping with FIG. 2 will not be described again, and only differences will be described. Unlike the first embodiment of FIG. 2 in which the adhesive layer 20 is disposed on the protrusion 11 of the first metal layer 10 , the ground reinforcement film 100B of FIG. 3 has the protrusion 11 of the first metal layer 10 . ) shows a structure in which the adhesive layer 20 and the first base layer 40 are sequentially stacked on one surface on which they are located.

Specifically, referring to FIG. 3 , the ground reinforcement film 100B according to the second embodiment includes a first metal layer 10 having a plurality of protrusions 11 on one surface; and an adhesive layer 20 and a first base layer 40 are sequentially stacked on one surface on which a plurality of protrusions 11 are formed with the first metal layer 10 as the center, and the second surface on which the protrusions 11 are not formed. It has a structure in which two metal layers 30 are disposed.

The first base layer 40 is a portion disposed on the adhesive layer 20, and the adhesive layer 20 and the plurality of protrusions 11 disposed therein are prevented from being contaminated by foreign substances in the external environment, and ground reinforcement. The film 100B is peeled off and removed before being applied to the electromagnetic wave shielding type composite substrate through a hot pressing (heating and pressing) process.

The first base layer 40 can be used without limitation as long as it is a conventional plastic film known in the art and can be peeled off, and a release paper can also be used.

Non-limiting 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 the like. , acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether turketone film, polyethersulfone film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic resin film, norbornene-based resin film, cycloolefin resin film, and the like. These plastic films may be transparent or translucent, or may be colored or uncolored. According to one example, the release film 140 may be polyethylene terephthalate (PET). According to another example, the release film 140 may be polyimide (PI).

A release layer may be disposed on such a plastic film. The release layer has a function of easily separating the adhesive layer 20 and the plurality of protrusions 11 disposed therein when the release film is separated from the contacting layer, for example, the adhesive layer 20 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 a conventional release agent component known in the art may be used. Non-limiting examples of the release agent that can be used include an epoxy-based release agent, a release agent made of a fluorine resin, a silicone-based release agent, an alkyd resin-based release agent, and a water-soluble polymer. The thickness of the release layer may be appropriately adjusted within a conventional range known in the art.

The thickness of the first base layer 40 is not particularly limited, and can be adjusted within a typical range known in the art, for example, about 25 to 150 μm, specifically about 25 to 100 μm, and more Specifically, it may be about 25 to 75 μm.

In addition, the release force of the first base layer 40 is not particularly limited, and may be, for example, about 10 to 500 gf/inch, and specifically about 30 to 200 gf/inch. The method of forming the said release layer is not specifically limited, Well-known methods, such as hot press, hot roll lamination, extrusion lamination, application|coating of a coating liquid, and drying, are employable.

The ground reinforcement film 100C according to the third embodiment of the present invention shown in FIG. 4 will be described. In Fig. 4, the same reference numerals as in Fig. 2 denote the same members.

Hereinafter, in the description of FIG. 4 , content overlapping with FIG. 2 will not be described again, and only differences will be described.

Specifically, referring to FIG. 4 , the ground reinforcement film 100C according to the third embodiment includes a first metal layer 10 having a plurality of protrusions 11 on one surface; and the adhesive layer 20 is disposed on one surface on which the protrusions 11 are formed with the first metal layer 10 as the center, and the second metal layer 30 and the second base layer 50 on the other surface on which the protrusions 11 are not formed. ) is a sequentially stacked structure.

The second base layer 50 is a portion disposed on the second metal layer 30, and serves to prevent the second metal layer 30 from being contaminated by foreign substances in the external environment, and improves handling and processability of the process. can be improved In addition, it may be peeled off and removed if necessary after the thermocompression process by heating/pressurization.

The second base layer 50 is not particularly limited, and a plastic film such as a protective film commonly known in the art may be used without limitation. For example, polyethylene terephthalate (PET), polybutylene terephthalate, polyester films such as polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, poly Vinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyether sulfone films, polyetherimide films, polyimide (PI) films, fluororesin films, polyamide films, acrylic resin films, norbornene-based resin films, cycloolefin resin films, and the like. Specifically, it may be at least one of a polyimide (PI) film, a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, a protective film, and a carrier film. Here, as the protective film and the carrier film, a conventional one known in the art may be used, and for example, an adhesive layer may be formed on one surface of a polyimide film, a PET film, or a PEN film. The pressure-sensitive adhesive layer may be a component commonly used in the art, for example, an epoxy-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and mixtures thereof may be contained. Preferably, it may be a PSA in the form of a liquid resin using a siloxane polymer as a binder.

The second base layer 50, such as a protective film or a carrier film, is a laminate in which the ground reinforcement film 100C and one surface of the electromagnetic wave shielding type composite substrate, specifically, the insulating layer of the electromagnetic wave shielding film (411 in FIG. 6) are bonded. It is located at the outermost (eg, top) surface of the structure. The second base layer 50 serves to absorb the stress and prevent the occurrence of cracks when stress for bending force or external force impact is applied to the electromagnetic wave shielding type composite substrate.

The thickness of the second base layer 50 is not particularly limited, and may be, for example, in the range of 30 to 100 μm, preferably 10 to 70 μm.

The ground reinforcement film 100D according to the fourth embodiment of the present invention shown in FIG. 5 will be described. In Fig. 5, the same reference numerals as in Fig. 2 denote the same members.

Hereinafter, in the description of FIG. 5 , content overlapping with FIG. 2 will not be described again, and only differences will be described.

Specifically, referring to FIG. 5 , the ground reinforcement film 100D according to the fourth embodiment includes a first metal layer 10 having a plurality of protrusions 11 on one surface; and an adhesive layer 20 and a first base layer 40 are sequentially stacked on one surface on which the protrusions 11 are formed with the first metal layer 10 as the center, and a second metal layer on the other surface on which the protrusions 11 are not formed. 30 and the second base layer 50 are sequentially stacked.

Meanwhile, in the present invention, the above-described four embodiments are exemplarily described. However, the present invention is not limited thereto, and the number of each layer constituting the ground reinforcement films 100A, 100B, 100C, and 100D and the order of their lamination may be freely selected and configured according to the use within the scope of the present invention. For example, by changing the order of each of the layers 10 , 20 , 30 , 40 , 50 , or by introducing another layer conventional in the art, it may have a multi-layered structure than the illustrated structure.

<Manufacturing method of ground reinforcement film>

In addition, the present invention provides a method for manufacturing the above-described ground reinforcement film. Such a ground reinforcement film may be manufactured without limitation according to a conventional method known in the art, and may have the following two embodiments.

Specifically, for a first embodiment of manufacturing the ground reinforcement film, (i) preparing a second base layer in which a second metal layer and a first metal layer having a plurality of protrusions are sequentially stacked on one surface; (ii) forming an adhesive layer by applying and drying an adhesive layer composition on the protrusions of the first metal layer; and (iii) laminating the first base layer on the adhesive layer.

a second metal layer on one surface; and a second base layer in which a first metal layer having a plurality of protrusions is sequentially stacked may be manufactured through a conventional deposition method or plating method known in the art.

A method of applying the adhesive layer composition on one surface of the first metal layer on which the protrusions are formed is not particularly limited, and a conventional coating method known in the art may be used without limitation. As an example, various methods such as a casting method, a dip coating, a die coating, a roll coating, a slot die, a comma coating, or a mixture thereof may be used. The drying process may be appropriately carried out within conventional conditions known in the art. For example, drying may be performed at 100 to 200 °C.

In addition, the adhesive layer composition is not particularly limited, and may be a composition including a thermosetting resin, a thermoplastic resin, or both known in the art. Specifically, the adhesive layer composition may be a composition comprising at least two or more of a polyurethane resin, a polyester urethane resin, and a polyester resin, or an epoxy resin and a cyanate resin, based on 100 parts by weight of the composition have. The above-mentioned adhesive layer composition may be appropriately adjusted within a range known in the art, and is not particularly limited.

Then, the ground reinforcement film may be manufactured by arranging the first base layer after drying the adhesive layer.

For a second embodiment of manufacturing the ground reinforcement film according to the present invention, (i) forming an adhesive layer by coating and drying an adhesive layer composition on the first base layer; (ii) a second metal layer on one surface; and preparing a second base layer in which a first metal layer having a plurality of protrusions is sequentially stacked; and (iii) laminating a first base layer and a second base layer, wherein the adhesive layer of the first base layer and the protrusions of the first metal layer laminated on the second base layer are disposed to face each other, and then laminated and cured It can be prepared including steps.

A method of applying the adhesive layer composition on the first base layer is not particularly limited, and a conventional coating method known in the art may be used without limitation. As an example, various methods such as a casting method, a dip coating, a die coating, a roll coating, a slot die, a comma coating, or a mixture thereof may be used. The drying process may be appropriately carried out within conventional conditions known in the art. For example, drying may be performed at 100 to 200 °C.

Then, the adhesive layer of the first base layer and the protrusions of the first metal layer of the second base layer are disposed to face each other, and then a thermocompression lamination process is performed.

The compression process conditions may be appropriately adjusted within a conventional range known in the art. For example, the conditions during the thermocompression bonding process may be carried out under the conditions of a temperature of 25 ~ 200 ℃, a pressure of 3 ~ 200 kgf / cm ² , and a compression speed of 0.1 m/min to 20 m/min. However, it is not particularly limited thereto.

Here, the first base layer and the second base layer may each have a sheet shape, or may be laminated according to a roll-to-roll method and then wound up in a roll shape. In addition, sheet-to-sheet (sheet to sheet) paper, roll-to-sheet (roll to sheet) paper, etc. may be used.

<Electromagnetic shielding type composite board>

In addition, the present invention provides an electromagnetic wave shielding type composite substrate in which the above-described ground reinforcement film is laminated on one surface.

6 schematically shows a cross-sectional structure of an electromagnetic wave shielding type composite substrate 400 according to an embodiment of the present invention.

Referring to FIG. 6 , the electromagnetic wave shielding type composite board 400 according to an embodiment includes a ground reinforcement film 100 , an electromagnetic wave shielding film 410 and a printed circuit board 420 , and these are sequentially stacked. indicates

More specifically, the electromagnetic wave shielding type composite board 400 includes a printed circuit board 420 having a ground portion 422; an electromagnetic wave shielding film 410 disposed on one surface of the printed circuit board 420 and including an insulating layer 411 and a conductive layer 412; and a ground reinforcement film 100 disposed on the electromagnetic wave shielding film 410, wherein at least a portion of the plurality of protrusions of the ground reinforcement film 100 is an insulating layer 411 of the electromagnetic wave shielding film 410. is electrically connected to the conductive layer 412 through the

As the printed circuit board 420 , a conventional circuit wiring board known in the art may be used without limitation.

In the present invention, the printed circuit board refers to a printed circuit board laminated in a single layer or at least two or more multi-layer structures by a plating through-hole method or a build-up method. These printed circuit boards include single-sided or double-sided printed circuit boards, or coreless type printed circuit boards. In addition, a conventional substrate made of a copper foil layer or having a form in which an insulating adhesive layer and a copper foil layer are laminated, a resin-coated copper foil, a copper-clad laminate (CCL), a flexible copper-clad laminate (FCCL), etc. may be used. Specifically, the printed circuit board 420 is preferably a flexible printed circuit board (FPCB) including at least one layer of circuit patterns.

The printed circuit board 420 may have a structure in which a coverlay is stacked on one or more circuit patterns. For example, the flexible printed circuit board may have a form in which one or more circuit patterns and a coverlay are sequentially stacked on polyimide (PI). Here, the coverlay refers to a composite film in which an adhesive is coated on a polymer film layer, for example, a polyimide film, or a release film in addition thereto. Such a coverlay layer is mainly used for protecting and insulating the exposed surface of the etched flexible printed circuit board (FPCB) circuit.

The electromagnetic wave shielding film 410 laminated on at least one surface of the printed circuit board 420 may include a conventional configuration known in the art, for example, a conductive filler on one or more insulating layers 411 The contained conductive layer 412 may be a laminated film or sheet.

The insulating layer 411 may use a conventional polymer resin known in the art without limitation, and may be, for example, a thermosetting resin, a thermoplastic resin, and a combination thereof. In particular, in the present invention, since at least some of the protrusions of the first metal layer in the ground reinforcement film 100 pass through the insulating layer 411 and conduct electricity through direct contact with the conductive layer 412, the insulating layer 411 It is preferable that it is a resin layer which does not contain a silver conductive filler.

The conductive layer 412 includes a conventional polymer resin in the art and a conductive filler. The conductive filler is not particularly limited as long as it is a component that absorbs and shields electromagnetic waves. For example, it may be a copper filler or nickel filler coated with Ag, Cu, Ni, Al, Ag, or a filler in which metal plating is performed on a polymer filler, resin ball, glass beads, or the like.

The electromagnetic wave shielding type composite substrate 400 according to the present invention may be manufactured according to a conventional method known in the art. For example, a printed circuit board 420 including one or more layers of circuit patterns and a ground; an electromagnetic wave shielding film 410 disposed on one or both sides of the printed circuit board 420; And it may be manufactured by sequentially laminating the ground reinforcement film 100 disposed on one surface of the electromagnetic wave shielding film 410 and then thermally pressing.

Specifically, the adhesive layer of the ground reinforcement film 100 is bonded to be in contact with the insulating layer 411 of the electromagnetic wave shielding film 410, and the conductive layer 412 of the electromagnetic wave shielding film 410 is a printed circuit board 420. After arranging to contact the upper portion of the coverlay 421, bonding to form a laminate. In this case, when the ground reinforcement film includes the first base layer (release film), the first base layer is detached and then bonded to the electromagnetic wave shielding film.

After constructing the laminate as described above, heat and/or pressure is applied to thermocompression. If necessary, the second base layer (protective film) positioned at the top of the laminate may be removed. At this time, the thermocompression conditions are not particularly limited, and for example, after forming the above-described laminate, thermocompression may be performed under conditions of a temperature of about 150 to 170 ℃, a pressure of 30 to 60 kgf / cm ² , and 50 to 60 minutes.

After the above-described thermocompression process, at least some of the plurality of protrusions positioned on the first metal layer of the ground reinforcement film 100 penetrate the insulating layer 411 of the electromagnetic wave shielding film 410 to pass through the conductive layer 412 ), and the conductive layer 412 is electrically connected to the ground portion 422 of the printed circuit board to form a ground connection structure.

Meanwhile, in the present invention, after sequentially stacking the printed circuit board 420, the electromagnetic wave shielding film 410, and the ground reinforcement film 100, the manufacturing of the electromagnetic wave shielding composite board through a thermocompression bonding process was specifically exemplified. However, the present invention is not limited thereto, and is manufactured by first manufacturing an electromagnetic wave shielding composite board by bonding a printed circuit board and an electromagnetic wave shielding film, then laminating a ground reinforcement film on the insulating layer of the electromagnetic wave shielding film and thermocompression bonding. belongs to the category of

As described above, in the present invention, by bonding the electromagnetic wave shielding film and the ground reinforcement film to the printed circuit board body, excellent electromagnetic wave shielding properties can be exhibited in various frequency ranges, and the ground in the printed circuit board is not exposed or additionally wired, thereby reducing processing costs. This is possible. In addition, since it is possible to easily connect the ground to a desired location, the degree of freedom of circuit and design freedom can be increased. Therefore, the printed circuit board according to the present invention can be used in various electronic and communication devices to improve transmission quality.

Hereinafter, the present invention will be specifically described by way of Examples, but the following Examples and Experimental Examples are merely illustrative of one aspect of the present invention, and the scope of the present invention is not limited to the Examples and Experimental Examples below.

[Example 1]

1-1. Manufacture of ground reinforcement film

A polyurethane resin-based adhesive layer composition is coated on the surface roughness portion of a copper foil (thickness 12 μm) having a surface roughness of 8.0 to 9.9 μm on one surface to form an adhesive layer to a thickness of 8 to 10 μm after drying, and release on the formed adhesive layer A first base layer, which is a PET film, was laminated. Gold (Au) as a second metal layer was deposited on the other surface coated with the adhesive layer of the first metal layer, and the thickness was 0.03 μm under an argon (Ar) atmosphere at room temperature under an argon (Ar) atmosphere. The formed second metal layer was laminated with a second base layer, which is an adhesive PET film, to prepare a ground reinforcement film.

1-2. Manufacture of electromagnetic wave shielding film

An electromagnetic wave shielding film (Doosan Electronics, DE-200) was used. As an electromagnetic wave shielding film, it is possible as long as the thickness of the insulating layer (insulator) is 8 μm or less, and the thickness of the conductive layer (conductive layer) is irrelevant.

1-3. Manufacture of electromagnetic wave shielding type composite board

The flexible printed circuit board was designed with a ground circuit of 3 mm in width and 24 mm in length on one side of a flexible copper clad laminate (FCCL) at intervals of 1 cm with respect to the central axis. For the coverlay, a 0.5 mm circle at the center of the ground circuit and a 5 x 4 mm square at the end of the ground circuit were punched, and then the entire surface was attached to the flexible copper clad laminate for which the ground circuit was designed. At this time, compression conditions were carried out at a temperature of 150 °C, a pressure of 50 kgf/cm ² , and 60 minutes. The circular punched part was energized with an electromagnetic wave shielding film attached, and the square punched part was used as a ground connection part.

On one side of the prepared flexible printed circuit board, the electromagnetic wave shielding film of Example 1-2 was cut to 15 mm in width and 100 mm in length, and the conductive layer of the electromagnetic wave shielding film and the circular punched ground of the flexible printed circuit board were It was located in the center of the width direction and was attached so that one side of it faced each other. At this time, the compression conditions were a temperature of 150° C., a pressure of 40 kgf/cm ² , and 60 minutes. After the compression process was completed, the insulating layer protective film of the electromagnetic wave shielding film was peeled off. After peeling the release PET film of the ground reinforcement film of Example 1-1, the adhesive layer of the ground reinforcement film and the insulating layer of the electromagnetic wave shielding film were placed to face each other and laminated, and the temperature of 170 ℃, 50 kgf / cm ² , and compressed under conditions of 60 minutes. By removing the second base layer of the compressed ground reinforcement film, an electromagnetic wave shielding type composite board was manufactured.

As shown in FIG. 6, the manufactured electromagnetic wave shielding composite substrate has a ground conduction structure in which a plurality of protrusions of the ground connection part in the ground reinforcement film penetrate the insulating layer of the electromagnetic wave shielding film and are connected to the conductive layer located thereunder. . FIG. 10(a) shows the upper surface of the manufactured electromagnetic wave shielding type composite substrate.

[Example 2]

A ground reinforcement film and an electromagnetic wave shielding composite board having the same were prepared in the same manner as in Example 1, except that a copper foil (thickness 18 μm) having a surface roughness of 8.2 to 10.4 μm was used on one surface.

[Experimental Example 1. Analysis of the first metal layer]

The physical properties of the first metal layer (copper foil) provided in the ground reinforcement film of the present invention were analyzed as follows.

7 is an SEM photograph of the first side (surface roughness portion) and the second side of the copper foil used in Example 1. FIG. It was confirmed that a plurality of protrusions having a predetermined height were present over the entire region on the first surface of the copper foil.

8 and 9 are topography showing the surface roughness (Rz) according to the thickness of the copper foil, respectively.

As a result of surface analysis using an electrolytic copper foil having a thickness of 12 µm, it was found that the surface roughness (Rz) of the copper foil was 8.0 to 9.9 µm over the entire region. In addition, as a result of surface analysis using an electrolytic copper foil having a thickness of 18 µm, it was found that the surface roughness (Rz) of the copper foil was 8.2 to 10.4 µm over the entire region.

[Experimental Example 2. Resistance evaluation of electromagnetic wave shielding type composite substrate]

The resistance change according to the distance of the designed ground circuit was measured using the electromagnetic wave shielding type composite board manufactured in Example 1.

A plan view of the resistance measuring specimen used in Experimental Example 2 is Fig. 10(a), and a cross-sectional view of the resistance measuring specimen is Fig. 10(b). In order to check the conductivity of the electromagnetic wave shielding film of the resistance measurement specimen, resistances were measured at intervals of 1 cm centering on the ground portion of the reference ground circuit. The resistance of the ground reinforcement film was measured while sequentially changing the distance between the uppermost layer (the second metal layer) and the grounding part of the printed circuit board as shown in Table 1 below, and the measurement results are shown in Table 1.

Unit (Ω) Distance (cm) 0 One 2 3 4 5 electromagnetic wave shielding film - - 0.2 0.2 0.3 0.3 0.4 ground reinforcement film 12 μm 0.5 0.6~0.7 0.7~0.8 0.8~0.9 0.9~1.0 1.0~1.1 electromagnetic wave shielding film - - 0.2 0.2 0.3 0.3 0.4 ground reinforcement film 18 μm 0.5 0.6~0.7 0.7~0.8 0.8~0.9 0.9~1.0 1.0~1.1

In general, resistance increases significantly with increasing distance. In the present invention, since the resistance increase rate of about 0.1 Ω/cm is shown, it can be seen that the resistance increase rate according to the distance is good, so that the ground connection is well made.

As described above, in the present invention, by employing a ground reinforcement film in which a first metal layer (eg, a copper foil layer) having a high surface roughness portion is disposed on one surface, it is placed at a desired location without additional processes such as through-hole formation or conductive adhesive filling. The wiring pattern for the ground can be easily connected. Accordingly, it was confirmed that the degree of freedom of the circuit can be provided, and the simplification of the manufacturing process and the effect of cost reduction can be achieved.

100A, 100B, 100C, 100D: Ground reinforcement film
10: first metal layer
11: protrusion
20: adhesive layer
30: second metal layer
40: first base layer
50: second base layer
400: electromagnetic wave shielding type composite board
410: electromagnetic wave shielding film (EMI shielding film)
411: insulating layer of electromagnetic wave shielding film
412: conductive layer of electromagnetic wave shielding film
420: printed circuit board
421: Coverlay layer
422: ground

Claims (17)

a first metal layer having a plurality of protrusions on one surface and integrally formed with the plurality of protrusions;
an adhesive layer covering one surface of the first metal layer;
a second metal layer formed on the other surface of the first metal layer;
a first base layer disposed on one surface of the adhesive layer; and
a second base layer disposed on one surface of the second metal layer; and
The first metal layer is an electrodeposited copper foil having a surface roughness (Rz) of 2-35 µm on one surface having a plurality of protrusions,
At least a portion of the plurality of protrusions is in contact with a surface of the adhesive layer, and an average height of the plurality of protrusions and a thickness of the adhesive layer are substantially the same.
delete delete According to claim 1,
A ratio (R1/R2) between the surface roughness (R1) of one surface and the surface roughness (R2) of the other surface in the first metal layer is 1 to 350 for the ground reinforcement film. According to claim 1,
The first metal layer is copper (Cu),
The second metal layer is aluminum (Al), chromium (Cr), titanium (Ti), silver (Ag), gold (Au), tungsten (W), molybdenum (Mo), tantalum (Ta), niobium (Nb), A ground reinforcement film comprising a metal selected from the group consisting of nickel (Ni), palladium (Pd), cobalt (Co), and zinc (Zn) or an alloy thereof. According to claim 1,
The outermost layer of the second metal layer is a ground reinforcement film composed of gold (Au). According to claim 1,
The thickness of the first metal layer is 5 to 35 μm,
The thickness of the second metal layer is 0.01 to 5 ㎛ ground reinforcement film. According to claim 1,
The adhesive layer is a ground reinforcement film that is a resin layer that does not include conductive particles. According to claim 1,
The adhesive layer is a ground reinforcement film comprising at least one of a thermoplastic resin and a thermosetting resin having a glass transition temperature (Tg) of -60 to 140 °C. 10. The method of claim 9,
The thermosetting resin is at least one ground reinforcement film selected from the group consisting of an epoxy resin, a phenol resin, a melamine resin, a silicone resin, a urethane resin, and a urea resin. 10. The method of claim 9,
The thermoplastic resin is a ground reinforcement film of at least one selected from the group consisting of an olefin resin, an acrylic resin, and rubber. delete According to claim 1,
The first base layer is a ground reinforcement film, characterized in that any one of a release paper and a release polymer film. According to claim 1,
The second base layer is at least one of a polyimide (PI) film, a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, a protective film, and a carrier film. According to claim 1,
The thickness of the first base layer and the second base layer is each 10 to 150 ㎛ ground reinforcement film. a printed circuit board having a ground part;
an electromagnetic wave shielding film disposed on one surface of the printed circuit board and including an insulating layer and a conductive layer; and
It is disposed on the electromagnetic wave shielding film, comprising the ground reinforcement film according to any one of claims 1, 4 to 11, and claim 13 to 15,
At least some of the plurality of protrusions of the ground reinforcement film penetrate the insulating layer of the electromagnetic wave shielding film and are electrically connected to the conductive layer,
The conductive layer is an electromagnetic wave shielding type composite board connected to the ground portion of the printed circuit board. 17. The method of claim 16,
The insulating layer of the electromagnetic wave shielding film is an electromagnetic wave shielding type composite substrate that is a resin layer that does not contain conductive particles.

Images