KR101334726B1 - Electromagnetic wave shield film and the manufacturing method thereof - Google Patents

Abstract

The present invention relates to an electromagnetic wave shielding film and a method of manufacturing the same, which enhances the electromagnetic shielding effect of the flexible PC, and is excellent in abrasion resistance and blocking resistance of the shielding film, and does not reduce or destroy the breakdown rate at a high level.
The electromagnetic wave shielding film includes: an insulating layer; and a primer layer on the insulating layer; and a conductive adhesive layer formed by coating and drying a conductive adhesive composition. The layer is a mixture of 4,4'-oxydianiline (ODA) and p-phenylene diamine (p-PDA) as diamines and pyromellitic dianhydride (PMDA) as dianhydrides, 3,3 ', 4, A mixture of 4'-biphenyltetracarboxylic dianhydride (BPDA) is mixed one-to-one to prepare a polyamic acid, which is composed of a polyimide film having a molecular weight of 5,000 to 1,000,000 which is imidized and arranged in a line irregularly. Became,
One side of a flexible printed circuit board (FPCB) that has excellent adhesion, heat resistance, electrical conductivity, flexibility, abrasion resistance, and flame retardancy, and requires high flexibility, high adhesion, and high heat resistance. It can be reliably applied to both sides, thereby providing an effect of effectively attenuating various electromagnetic waves generated in the substrate circuit.

Description

Electromagnetic wave shielding film and its manufacturing method {ELECTROMAGNETIC WAVE SHIELD FILM AND THE MANUFACTURING METHOD THEREOF}

The present invention relates to a method for manufacturing a flexible PC cost electromagnetic wave shielding film, and more particularly, to increase the electromagnetic shielding effect of the flexible PC cost, excellent wear resistance and blocking resistance of the shielding film, and to reduce or break the fracture rate at a high step An object of the present invention is to provide an electromagnetic wave shielding film and a method of manufacturing the same.

As the trend of light and short and short of portable electronic and display electronic devices has recently advanced, the signal transmission speed between components in the device has been increased, and as the circuit board has high density and fine circuitization, signal interference due to the occurrence of electromagnetic noise between adjacent circuits (EMI, Electromagnetic Interference) damage is on the rise. In order to effectively block such electromagnetic waves, it is necessary to enclose the substrate circuit in a conductor film having excellent electrical conductivity and to devise the electromagnetic waves generated from the inside to be attenuated through the conductor. Generally, a metal thin film such as aluminum foil or silver foil having high conductivity is used. Products such as a conductive adhesive film that adheres or uniformly applies a conductive paste prepared by dispersing conductive powder in a binder resin to a surface of a circuit board, or form a conductive paste into a film and heat-attach have been applied.

Especially in the case of flexible printed circuit boards requiring repeated bending characteristics, the metal thin film or liquid paste paints have poor bending characteristics, so they have limitations in use, and heat adhesiveness is good for applications requiring excellent bending characteristics. The demand for product of this excellent adhesive film shape is greatly increased.

Conventional electromagnetic wave shielding adhesive film includes a reinforcing shielding film having a conductive adhesive layer on one side of a cover film and a shielding layer of a metal thin film layer, if necessary, and a conductive adhesive layer and a releasable reinforcement film sequentially stacked on the other surface. It is known (refer patent document 1). Moreover, the shielding film which has a shielding layer which has a conductive adhesive layer or a metal thin film, and the base film which consists of aromatic polyamide resin is known (refer patent document 2).

Patent Document 1: Japanese Patent Publication No. 2003-298285

Patent Document 2: Japanese Patent Laid-Open No. 2004-273577

However, the cover film used for the shielding film is often made of engineering plastics such as polyphenylene sulfide (PPS), polyester, and aromatic aramid, and the thickness of the cover film is thick ( For example, 9 micrometers) rigidity is large.

For this reason, the flex resistance of the cover film is lowered. In addition, when reinforcing the shielding FPC by adhering a glass epoxy board or the like on the cover film after the adhesive film is peeled off from the shielding FPC, the PPS is hardly adhered to the glass epoxy substrate or the like, and for this reason, PPS Is difficult to bond.

Accordingly, the present invention is to solve the problems of the prior art described above, in addition to sufficient electromagnetic wave shielding properties, has excellent flex resistance and heat resistance to withstand high temperatures during lead-free solder reflow, attached to a flexible printed wiring board, etc. It is an object of the present invention to provide an electromagnetic wave shielding film which can be suitably used for shielding applications.

In addition, another object of the present invention is to provide a method for producing an electromagnetic wave shielding film having the above-described improved performance at low cost and stably.

In addition, the present invention provides a method for shielding the electromagnetic wave of the adherend using the electromagnetic shielding adhesive film.

In the electromagnetic wave shielding film of the present invention, the electromagnetic wave shielding film comprising an insulating layer; and a primer layer on top of the insulating layer; and a conductive adhesive layer formed by coating and drying a conductive adhesive composition;

The insulating layer 2,

4,4'-oxydianiline (ODA) and p-phenylene diamine (p-PDA) mixtures as diamines and pyromellitic dianhydrides (PMDA) as 3,3 ', 4,4'- A mixture of biphenyltetracarboxylic dianhydride (BPDA) is mixed one-to-one to prepare a polyamic acid, which is characterized in that the polyimide film is composed of a molecular weight of 5,000 to 1,000,000 which is imidized and irregularly arranged linearly. .

The insulating layer has a thickness of 1 μm to 15 μm.

The conductive adhesive layer 4 is formed of a thermosetting composition for a conductive adhesive layer including 80 to 300 parts by weight of a mixed conductive filler composed of a conductive filler in the form of particles per 100 parts by weight of the binder resin composition, and the composition for the conductive adhesive layer and the insulating layer. The binder resin composition to form a 50 to 150 parts by weight of the thermosetting resin, 5 to 20 parts by weight of the curing agent, and 10 to 30 parts by weight of the phosphorus-based flame retardant per 100 parts by weight of the thermoplastic resin, the thermoplastic resin has a weight average molecular weight of 3,000 ~ It is characterized by consisting of 300,000.

The thermosetting resin of the binder resin composition is characterized by comprising at least one thermosetting material selected from the group consisting of an epoxy resin, an unsaturated polyester resin, an acrylic resin and a phenol resin having a weight average molecular weight of 300 to 3,000.

The curing agent is characterized by consisting of at least one material selected from aromatic amine compound curing agent, imidazole curing agent or phenol curing agent.

The phosphorus-based flame retardant is characterized in that the melting point is 150 ~ 300 ℃.

The conductive filler in the form of particles is composed of at least one powder selected from the group consisting of gold powder, silver powder, silver coated copper powder, silver coated nickel powder and silver coated iron powder, and has a particle size of 0.5 μm to 20 μm. It is characterized by.

Electromagnetic shielding film manufacturing method for achieving the object of the present invention, after applying the composition solution for the insulating layer to the release film and dried, attaching the carrier film (1) on one side, removing the release film to remove the insulating layer (2) Forming an insulating layer forming step (S10); A primer layer forming step (S20) of applying a primer solution composition prepared by mixing and diluting a primer resin composition in a solvent on an insulating layer and drying to form a primer layer (3); and a binder resin composition and a mixed conductive filler in a solvent A conductive adhesive layer forming step (S30) of applying a composition solution for a conductive adhesive layer prepared by adding and stirring to a release film and drying to form a conductive adhesive layer (4); And, the conductive adhesive layer 4 and the primer layer It characterized in that it comprises a; (3) a lamination step (S40) for laminating so as to face each other.

According to another aspect of the present invention, there is provided a method of manufacturing an electromagnetic shielding film, by applying a composition solution for an insulating layer to a release film and drying the adhesive film to one surface, and removing the release film. (2) forming a coating insulating layer forming step (S110); and a primer layer composition solution prepared by mixing and diluting the primer resin composition in a solvent on the insulating layer and dried to form a primer layer (3) A layer forming step (S120); and a conductive resin layer composition solution prepared by adding a binder resin composition and a mixed conductive filler to a solvent and stirring the composition solution on the upper part of the primer layer 3 and drying the conductive adhesive layer 4 To form a conductive adhesive layer forming step (S130); characterized in that it comprises a.

The electromagnetic wave shielding film 10 produced by the present invention having the above-described configuration is excellent in adhesion, heat resistance, electrical conductivity, flexibility, abrasion resistance, and flame retardancy, so that printed circuit boards, in particular, high flexibility, high adhesion, high heat resistance, etc. It can be reliably applied to one or both sides of the required flexible printed circuit board (FPCB).

Accordingly, the present invention provides an effect of effectively attenuating various electromagnetic waves generated in a substrate circuit.

1 is a cross-sectional view of an electromagnetic wave shielding film 10 according to an embodiment of the present invention,
2 is a view showing the wear resistance test apparatus 100,
3 is a view showing a test piece 200 for measuring step resistance,
4 is a view showing the flexibility test apparatus 300,
5 is a flowchart illustrating a process of manufacturing an electromagnetic wave shielding film manufacturing method and a printed circuit board manufacturing method with an electromagnetic wave shielding film according to an embodiment of the present invention;
6 is a flowchart illustrating a process of manufacturing a method of manufacturing an electromagnetic wave shielding film and a method of manufacturing a printed circuit board with an electromagnetic wave shielding film according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings showing an embodiment of the present invention will be described in more detail the present invention.

In the following description of the present invention with reference to the embodiments of the present invention, when it is determined that the detailed description of the related known configuration or function may obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, it will be described in the following preferred embodiments of the present invention, but the technical spirit of the present invention is not limited to this, it is obvious that it can be variously modified by those skilled in the art.

The electromagnetic wave shielding film 10 of the present invention has a multilayer structure including a conductive adhesive layer 4 and an insulating layer 2 laminated on one surface thereof, and FIG. 1 illustrates an electromagnetic wave shielding film according to an embodiment of the present invention. 10) is a cross-sectional view.

The electromagnetic wave shielding film 10 of FIG. 1 includes an insulating layer 2 formed on one surface of the carrier film 1, a primer layer 3 formed on the insulating layer 2, and a primer layer 3. And a release film 5 for protecting the exposed surface of the conductive adhesive layer 4 and the conductive adhesive layer 4 formed by lamination or lamination.

In this configuration, the release film 5 is removed before performing the hot press process as protecting the conductive adhesive layer 4 before the hot press process. The electromagnetic wave shielding film 10 having the above-described configuration may be attached by hot pressing in a state where the conductive adhesive layer 4 is attached to a surface on which a circuit pattern of a printed circuit board mounted on a press is formed after removing the release film 5. As a result, a printed circuit board (not shown) having an electromagnetic shielding film is manufactured.

As described above, when the electromagnetic wave shielding film 10 is attached to a printed circuit board (not shown), the conductive adhesive layer 4 absorbs electromagnetic waves generated from a circuit pattern on the printed circuit board (not shown) to the outside. By transmitting, the electromagnetic wave causing interference between circuit patterns is removed.

Hereinafter, the electromagnetic wave shielding film 10 according to an embodiment of the present invention will be described by dividing the carrier film 1, the insulating layer 2, the primer layer 3, the conductive adhesive layer 4, and the release film 5. .

1. Carrier film (1)

The carrier film 1 is a release protection film, which serves to prevent contamination by foreign matter from the external environment and to protect the surface in the hot press process until the electromagnetic wave shielding film 10 is used by the end-user. do. The carrier film 1 has a silicone, fluorine, long chain alkyl acrylate or the like formed on the surface of the base film formed of a material such as polyethylene, polypropylene, or polyethylene terephthalate in order to more easily peel off the electromagnetic wave shielding film 10. Use a release agent treated with.

2. Insulation layer (2)

The electromagnetic wave shielding film 10 according to the present invention includes an insulating layer 2 formed by applying a composition solution for an insulating layer to a release film and drying and then attaching the carrier film 1 to one surface and then removing the release film. do.

<Polyimide Insulation Layer Resin Composition>

The composition for insulating layers used to form the insulating layer 2 is a polyimide resin. The electromagnetic wave shielding film 10 according to the present invention may be any type as long as it can have component reliability in terms of basic physical properties, that is, adhesive force, heat resistance, chemical resistance, flexibility, flame retardancy, and the like, to be used as an adhesive material for a circuit board.

In the present invention, the polyimide resin is prepared from a polyamic acid precursor obtained by reacting an aromatic tetracarboxylic dianhydride and an aromatic diamine in a polar aprotic solvent.

Preferably the dianhydride is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (3,3', 4,4'-Biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride ( Pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA). Preferably, the diamine is p-phenylenediamine (p-PDA), oxydianiline (ODA), N, N'-diphenylmethylenediamine (MDA) And diaminobenzophenone (DABP). More preferably the dianhydride is BPDA and PMDA and the diamine comprises p-PDA and ODA.

As the organic solvent used to prepare the polyamic acid copolymer, it is preferable to use a polar solvent such as ether and ketone which are compatible with the polyamic acid produced after polymerization.

Specific examples include 1-methyl-2-pyrrolidone (hereinafter referred to as NMP), N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). One or more selected from the group can be used alone or in combination.

When the polymerized polyamic acid is cured and imidized, a polyimide copolymer, which is the insulating layer resin of the present invention, can be produced. The polyamic acid precursor synthesized by dianhydride and diamine is known by dehydration imidation. It can polyimide. Dehydration imidization reactions are classified into chemical imidization methods and thermal imidization. Any dehydration method, including these two combinations, may be applied to the preparation of the polyimide.

The chemical imidization method includes a step of chemically dehydrating the acid by reacting the polyamic acid obtained in the above method with a dehydrating agent capable of hydrolyzing the acid. Examples of dehydrating agents usable in this method include dicarboxylic acid anhydrides such as acetic anhydride and trifluoroacetic anhydride; Typically, derivatives of polyphosphoric acid, phosphorus pentoxide and the like: acid chlorides such as methanesulfonic acid chloride, phosphorus pentachloride and thionyl chloride are exemplified. Two or more of these dehydrating agents may be used alone or in combination. The amount of the dehydrating agent to be used is in the range of 2 to 10 moles, preferably 2 to 4 moles, per 1 mole of the total amount of the diamines used. The reaction temperature and the reaction pressure of the chemical imidization reaction temperature are not particularly limited, and known conditions may be applied. Specifically, the temperature is in the range of −10 ° C. to 120 ° C., more preferably in the vicinity of room temperature to 70 ° C., most preferably at room temperature.

An additional solvent may be added to the reaction system in order to remove water formed through dehydration.

Benzene, toluene, o-, m-, p-xylene, o-, m-, p-chlorobenzene, o-, m-, p-chloro toluene etc. are mentioned as this solvent. These solvents may be used alone or in combination. The amount to be used is not particularly limited.

The reaction temperature, reaction time, and reaction pressure in thermal imidation are not particularly limited, and known conditions may be applied. Specifically, the reaction temperature is 80 ° C to 400 ° C, preferably 100 ° C to 300 ° C, and most preferably 150 ° C to 200 ° C. The reaction time depends on the type of solvent used and other reaction conditions, but is preferably in the range of 2 to 10 hours. The reaction pressure is sufficient at normal pressure.

3. Primer layer (3)

The primer layer 3 is a known adhesive resin; A thermoplastic resin, a thermosetting resin, or the like may be used, but acrylic, epoxy, urethane, modified acrylic, and modified epoxy resins have excellent adhesion and reliability at the interface between the polyimide insulating layer 2 and the conductive adhesive layer 3. And modified urethane-based curable adhesives. All of them may have a viscosity such that resin does not flow out of the electromagnetic shielding film during hot pressing, and the thickness of the primer layer 3 is about 0.5 to 5 µm, preferably 0.5 to 1.5 µm.

4. Conductive Adhesive Layer (4)

The conductive adhesive layer 4 is formed from the composition for conductive adhesive layers containing a binder resin composition and a mixed conductive filler. The method of forming the conductive adhesive layer 4 will be described in detail in the method for producing an electromagnetic wave shielding film to be described later.

4-1. Binder Resin Composition For Conductive Adhesive Layer 4

The binder resin composition includes a thermoplastic resin, a thermosetting resin, a curing agent and a phosphorus flame retardant. In addition, the binder resin composition may preferably further include a curing accelerator. In the conventional electromagnetic wave shielding film 10 manufacturing, the resin component of the binder resin composition uses an adhesive component capable of forming a film of a thin film using a solution coating process. In the present invention, a thermoplastic resin is used as the resin component of the binder resin composition. And thermosetting resins are used in combination, which is advantageous in terms of a circuit board manufacturing process manufactured through a high temperature hot press process, and more advantageous in terms of overall reliability of the circuit board after heat curing.

First, in order to improve the adhesion and coating property of the adhesive film, the adhesive composition contains a thermoplastic component. Such thermoplastic components are not particularly limited, and conventionally known thermoplastic components can be used. For example, Copolymer containing a vinyl monomer and acrylonitrile, styrene, etc. as a main component of acrylic rubber, acrylic acid alkyl ester, and methacrylic acid ester; Polyisoprene rubber; Polybutadiene rubber; 1,2-polybutadiene rubber; Styrene-butadiene rubber; Acrylonitrile butadiene rubber (hereinafter also referred to as 'NBR'); Ethylene butadiene rubber; Carboxylated nitrile rubber etc. are mentioned preferably, More preferably, it is an acrylic rubber, NBR, ethylene butadiene rubber, or polybutadiene rubber, Especially preferably, it is NBR. The polybutadiene rubber or 1,2-polybutadiene rubber may be substituted with a carboxyl group or a hydroxyl group. The styrene butadiene rubber may be substituted with a hydroxyl group.

The NBR may be substituted with a carboxyl group, a hydroxyl group, or an acryloyl group.

Such a thermoplastic component preferably has a functional group that reacts with the thermosetting component.

When the thermoplastic component and the thermosetting component react, there is an advantage in that the heat resistance is increased. Although it depends also on the kind of thermosetting component, a carboxyl group, an epoxy group, or a hydroxyl group etc. are mentioned suitably as said functional group, A carboxyl group is more preferable from a viewpoint of reactivity, universality, etc.

The NBR containing the carboxyl group has a weight average molecular weight of 2,000 to 300,000, preferably 3,000 to 200,000, and has an acrylonitrile content of 10 to 60 parts by weight, preferably 15 to 30 parts by weight, and a carboxyl group content. It shall be 1-20 weight part. At this time, when the weight average molecular weight of NBR is lower than 3,000, the thermal stability is poor, and when it is higher than 200,000, the solubility in the solvent is deteriorated. In addition, when the acrylonitrile content is lower than 15 parts by weight, the solvent solubility is lowered, and when higher than 30 parts by weight, the electrical insulation is poor. And when the content rate of the carboxyl group is 1 to 20 parts by weight, the adhesion between NBR and other resins, and the adhesive substrate is easy, so that the adhesive force increases.

Next, the reflow solder heat resistance and workability can be improved by including the thermosetting component in the thermosetting adhesive composition according to the present invention. In the related art, increasing the ratio of the thermoplastic resin to increase the adhesive strength reduces the thermosetting portion, thereby sacrificing heat resistance and workability, and increasing the ratio of the thermosetting resin to increase the heat resistance and workability has a problem in that the adhesive force is sacrificed. As the thermosetting resin used in the present invention, epoxy resins, phenol resins, vegetable oil-modified phenol resins, xylene resins, guanamine resins, diallyl phthalate resins, vinyl ester resins, unsaturated polyester resins, polyimide resins, and polyurethane resins are preferable. Preferably, it is an epoxy resin, a phenol resin, or a vegetable oil modified phenol resin, More preferably, it is an epoxy resin excellent in reactivity and heat resistance. Examples of such epoxy resins include bisphenol-type epoxy resins, bisphenol F-type resins, and bisphenol-type epoxy resins such as bisphenol S-type resins, phenol novolak-type epoxy resins, cresol novolak-type epoxy resins, and novolak-type epoxy resins such as bisphenol-A novolak-type epoxy resins. Resin, alicyclic epoxy resin, aliphatic chain epoxy resin, diglycidyl ether of biphenol, diglycidyl ether of naphthalene diol, diglycidyl ether of phenol, diglycidyl ether of alcohol And at least one selected from the group consisting of these alkyl substituents, halides, and hydrogen additives. Among these, bisphenol-A epoxy resin or novolak-type epoxy resin is particularly preferable.

The epoxy resin of the thermosetting adhesive composition according to the present invention may be added to 50 to 300 parts by weight based on 100 parts by weight of the thermoplastic resin (NBR) and the epoxy equivalent (g / eq) is preferably 180 to 1000. Preferably, the epoxy resin is characterized in that 50 to 100 parts by weight with respect to 100 parts by weight of NBR, which is less elasticity of the adhesive film in the semi-cured state when added more than the epoxy resin compared to the NBR and when the reinforcement and lamination This is because the airtightness is insufficient, the adhesive film is easily expanded due to thermal stimulation, and reinforcement and lifting may occur.

Moreover, the thermosetting adhesive composition which concerns on this invention can improve heat resistance by containing a hardening | curing agent, and can especially improve reflow solder heat resistance. As such a hardening | curing agent, a polyamine hardening | curing agent, an acid anhydride type hardening | curing agent, a boron trifluoride complex salt, a phenol resin etc. are mentioned, for example.

As said polyamine hardening | curing agent, For example, aliphatic amine hardening | curing agents, such as diethylene triamine, tetraethylene tetratamine, and tetraethylene pentamine; Alicyclic amine curing agents such as isophorone diamine; Aromatic amine curing agents such as diaminodiphenylmethane and phenylenediamine; Dicyandiamide, and the like. Phthalic anhydride, a pyromellitic anhydride, trimellitic anhydride etc. are mentioned as said acid anhydride type hardening | curing agent, for example. These hardeners may be used independently and may use two or more types together as needed.

It is preferable that 1-50 weight part of said hardening | curing agents of the thermosetting adhesive composition concerning this invention are contained with respect to 100 weight part of said thermoplastic resins, More preferably, it is 5-20 weight part. When the content of the curing agent is 5 parts by weight or less, the reflow solder heat resistance of the adhesive film made of the adhesive composition of the present invention is lowered, and when the concentration is 20 parts by mass or more, the workability of the adhesive composition is lowered, or the adhesive composition of the present invention is Outflow at the time of pressing of the formed adhesive film increases.

The conductive adhesive layer 4 having the above composition has a viscosity of 100 to 2,000 cps, preferably 400 to 1,500 cps, and is applied on a release film so as to have a thickness of 8 to 20 μm after drying and 2 to 10 at 50 to 200 ° C. After drying for a minute, a thermosetting adhesive film is obtained by laminating with the primer layer 3 on the insulating layer 2. Alternatively, the direct release layer 4 may be obtained by directly coating the primer layer 3 on the insulating layer 2.

Although it does not restrict | limit especially as a coating method, The coating method using a comma coater, a reverse roll coater, etc. is mentioned. In addition, the thickness, shape, etc. of the adhesive bond layer of the adhesive film which apply | coated the thermosetting adhesive composition which concerns on this invention are not specifically limited, It can determine suitably according to a use site and a use purpose.

4-2. Mixed Conductive Filler

The conductive adhesive layer 4 is formed of a composition for a conductive adhesive layer comprising a binder resin composition and a mixed conductive filler, wherein the mixed conductive filler is composed of a conductive filler in the form of particles and a conductive filler in the form of fibers.

The electromagnetic wave shielding film 10 of the present invention must realize high flexural property at the same time that cracks of the conductive contact agent should not occur in the electromagnetic shielding film 10 in addition to implementing excellent electrical conductivity, even under repeated bending loads. When using a conductive filler in the form of a large amount of particles in order to improve the electrical conductivity, the brittleness of the electromagnetic wave shielding film 10 increases, resulting in a problem of deterioration in bending characteristics.

Therefore, in order to satisfy both the electrically conductive properties and the bendability characteristics of the electromagnetic wave shielding film 10, it is preferable to mix a certain amount of conductive fillers to improve the electrical contact between the conductive fillers in the form of particles and to improve the bendability of the electroconductive adhesive film. . The content of the mixed conductive filler in the composition for the conductive adhesive according to the present invention uses a mixed conductive filler of 80 to 500 parts by weight per 100 parts by weight of the binder resin composition, the electromagnetic shielding film 10 when the conductive filler content is less than 80 parts by weight The electrical conductivity of greatly decreases and exceeds 500 parts by weight causes a problem that the brittleness of the electromagnetic wave shielding film 10 increases and the flexibility is greatly reduced.

The conductive filler in the form of particles constituting the mixed conductive filler is at least one powder selected from the group consisting of gold, silver, copper, nickel, iron and silver coated copper powder, silver coated nickel powder and silver coated iron powder having excellent electrical conductivity. It is composed.

Among them, the specific gravity is low in order to maintain the sedimentation rate relatively slow when mixing with the binder resin composition, the oxidation resistance is excellent, and the electrical contact forming ability between the filler particles is excellent, and the price increase factor according to the filler addition amount is relatively low. Powder is preferred.

The conductive filler in the form of particles may have specific shapes such as spherical shape, plate shape, and amorphous shape, and it is preferable to use a mixture of spherical shape, plate shape, and branch shape as appropriate from the viewpoint of electrical contact formation.

In addition, the conductive filler in the form of particles consists of at least one powder selected from the group consisting of gold, silver, copper, nickel, iron and silver coated copper powder, silver coated nickel powder and silver coated iron powder, the particle size is 0.5 It is preferable that it is -20 micrometers.

In general, the thickness of the conductive adhesive layer 4 is maintained at 15 μm or less from the standpoint of implementing flexural characteristics. When the particle size of the conductive filler in the form of particles is less than 0.1 μm, the probability of forming an electrical contact is low, which satisfies the electrical conductivity. When it is impossible to obtain and exceeds 15 µm, it may be difficult to obtain a conductive adhesive layer 4 having a uniform physical property because the added particle size is too large compared to the thickness of the conductive adhesive layer 4.

To the adhesive composition of the present invention, any other components of those used in the adhesive composition, that is, tackifiers, stabilizers, antioxidants, fillers, reinforcing agents, pigments, antifoaming agents, and the like may be additionally added as necessary.

5. Release Film (5)

The release film 5 is a kind of the carrier film 1 attached to the conductive adhesive layer 4 and serves to protect the conductive adhesive layer 4. The electromagnetic film shielding film 10 may be hot pressed. Is removed prior to attachment to the printed circuit board.

<< Manufacturing method of electromagnetic wave shielding film 10 >>

5 is a flowchart illustrating a process of manufacturing an electromagnetic wave shielding film manufacturing method and a printed circuit board manufacturing method with an electromagnetic wave shielding film according to an embodiment of the present invention.

As shown in FIG. 5, the electromagnetic wave shielding film 10 is formed by applying a composition solution for an insulating layer to a release film, drying, attaching a carrier film to one surface, and removing the release film to form an insulating layer 2. (S10); and a primer layer forming step (S20) of applying a primer solution prepared by mixing and diluting a primer resin composition to a solvent on an insulating layer and forming a primer layer (3); and a binder resin in a solvent Conductive adhesive layer forming step (S30) of applying a composition solution for the conductive adhesive layer (4) prepared by adding a composition and a mixed conductive filler and stirring to a release film and drying to form a conductive adhesive layer (4); And a laminating step (S40) of laminating the conductive adhesive layer 4 and the primer layer 3 to face each other.

6 is a flowchart illustrating a process of manufacturing a method of manufacturing an electromagnetic wave shielding film and a method of manufacturing a printed circuit board with an electromagnetic wave shielding film according to another embodiment of the present invention.

Another example of the manufacturing method of the electromagnetic wave shielding film 10 according to the present invention is to apply the composition solution for the insulating layer to the release film and dry and then attach the carrier film on one side, remove the release film to remove the insulating layer (2) A coating layer forming step (S110) to form; and a primer layer forming step of forming a primer layer (3) by coating and drying the primer solution composition prepared by mixing and diluting the primer resin composition in a solvent on the insulating layer ( S120); and a binder resin composition and a mixed conductive filler added to the solvent, and the composition solution for the conductive adhesive layer (4) prepared by stirring and applied to the upper portion of the primer layer (3) and dried to form a conductive adhesive layer (4) It includes; conductive adhesive layer forming step (S130).

In the manufacturing method of the electromagnetic wave shielding film 10 of FIGS. 5 and 6 described above, the type of the base film such as the carrier film 1 or the release film is not particularly limited. The release film is a PET film subjected to silicone release treatment, the carrier film (1) is characterized in that the release protective film is acrylic adhesive treatment.

The solvent is not particularly limited as long as it is compatible with the binder resin composition and the mixed conductive filler. Specific examples thereof include a mixed solvent in which toluene / methyl ethyl ketone is mixed at a predetermined weight ratio.

The composition solution for the conductive adhesive layer 4 or the composition solution for the insulating layer 2 or the composition for the conductive adhesive layer 4 or the composition for the insulating layer 2, that is, the content of solid content is in the range of about 15 to 60% by weight. It is preferable.

In addition, the drying temperature is appropriately selected depending on the type of the solvent used, and has a range of about 80 ~ 150 ℃. In addition, the lamination is usually made by hot roll lamination, the temperature of the hot roll has a range of about 60 ~ 120 ℃.

The electromagnetic wave shielding film 10 formed by the above manufacturing method has a multilayer structure including a conductive adhesive layer 4 and an insulating layer, the total thickness of the electromagnetic wave shielding film 10 is about 8 ~ 30㎛, and insulation The thickness of the layer is about 2 to 5 µm, preferably 5 µm or less, and the thickness of the conductive adhesive layer 4 is about 3 to 25 µm, preferably 5 to 18 µm.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only intended to more clearly describe the present invention, and do not limit the protection scope of the present invention.

<Production of Polyimide Insulation Layer>

3.39 g (31.4 mmol) p-phenylenediamine (p-PDA) and 7.85 g (39.3 mmol) oxydianiline (ODA), 0.15 g in 168 ml of N-methylpyrrolidone (NMP) solution 148 g of dianhydrous phthalic anhydride (PMDA) and cresol were added and stirred at 35 ° C. until a homogeneous diamine solution was formed at 60 rpm. To this diamine solution, 20.76 g (70.6 mmol) of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) are added with classification, the mixture is stirred and reacted for 3 hours. A 18.6% polyamic acid solution was formed with a weight solid. Since dianhydrides react with polar aprotic solvents, p-PDA and ODA solids were first added to the solvent, and then BPDA was gradually added to the diamine solution. The reaction system was heated from room temperature to 200 ° C. over about 2 hours, and then further reacted for 4 hours to prepare a polyimide solution by chemical imidization.

In the present invention, the important properties of the resulting polyimide resin depend on the molar ratio of p-PDA to ODA. For example, changing the molar ratio of p-PDA to ODA will result in different values of the coefficient of thermal expansion and the flexibility of the polyimide resin. In the experimental example, the molar ratio of the dianhydride to diamine of the reactant of the polyamic acid solution is 1: 1, and the molar ratio of p-phenylenediamine (p-PDA) to oxydianiline (ODA) of diamine. Was 0.8: 1.0. This polyamic acid solution used 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride (BPDA) and phthalic anhydride (PMDA) as a multiple dianhydride component.

PET carrier film coated with acrylic release agent on the surface of the obtained polyimide resin was coated on a silicone release coated PET film (36 μm, SKC) release treated surface to a thickness of 4 μm using a comma coater and then dried 50 micrometers, Maxfill) and the acrylic mold release surface were laminated at 80 degreeC.

<Examples>

A suitable amount of a toluene / methyl ethyl ketone mixed solvent (weight ratio 50:50) is added to the stirrer, and a thermoplastic resin, a thermosetting resin, a curing agent, a curing accelerator, a flame retardant, and a conductive metal powder are sequentially added thereto, followed by stirring. A composition solution was obtained.

The obtained composition solution for the conductive adhesive layer 4 was applied to the silver layer surface of the silver-coated polyimide film obtained above with a bar coater and dried in a drying zone at 120 ° C. for 5 minutes to remove the solvent, thereby thermosetting conductive adhesive layer. (4) The electromagnetic wave shielding film 10 of the multilayer structure which has a thickness of 10 micrometers was manufactured.

Ο: applied x: not applied

PI film: synthetic polyimide film + primer layer + ultrathin silver layer

PPS film: polyphenylene sulfide film + ultrathin silver layer

m-Epoxy: Modified Epoxy Film

NBR: acrylonitrile butadiene rubber, Zeon Chemical, Nipol-1072

4P: YDCN 500-4P, cresol novolac epoxy, Kukdo Chemical

F170: YDF-017, bisphenol F epoxy, Kukdo Chemical Co., Ltd.

C3000: LC-3000, latent hardener, Shin-A T & C Co., Ltd.

2E4MZ: 2-ethyl4-methylimidazole, Air Products and Chemicals, Inc.

OP930: Exolit OP-935, phosphinate powder, Clariant Co.

Ag1110: CE-1110, silver coated copper powder, FUKUDA METAL FOIL & POWDER CO., LTD.

As shown in Table 1, Examples 1 to 4 prepared a PI-based electromagnetic wave shielding film according to the above method, Comparative Example 1 used a commercially available polyphenylene sulfide film instead of a synthetic polyimide film, Comparative Example 2 is a support film Instead of using a solution from which the metal powder was removed from the conductive adhesive composition was used after forming a film according to the synthetic polyimide insulating layer manufacturing method.

Table 1 shows the components and contents of the binder resin composition prepared by Examples 1 to 4 and Comparative Examples 1 to 2. In addition, Table 2 shows the characteristics of the electromagnetic wave shielding film prepared by Examples 1 to 4 and Comparative Examples 1 to 2.

<< Evaluation of Physical Properties of Electromagnetic Wave Shielding Film 10 >>

The abrasion resistance, electrical conductivity, flexibility, adhesion, heat resistance, and flame retardance of the electromagnetic wave shielding films 10 prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated based on the following physical property evaluation methods.

(1) Abrasion resistance

After cut | disconnecting the electromagnetic wave shielding film 10 to 20 mm and 50 mm long, a conductive adhesive layer (Copper Clad Laminate; 35 micrometers of copper foil thickness, 25 micrometers of polyimide film thicknesses) is formed on the copper foil surface. 4) was welded so as to come in contact with each other and cured at 160 ° C. for 1 hour to prepare a specimen for measuring wear resistance.

2 is a diagram illustrating the wear resistance test apparatus 100.

As shown in Figure 2, the base 101, the support 110, the weight 120 and the friction member 130 is composed of a cylindrical rubber having a hardness of 1H and a diameter of 5mm mounted on the lower portion of the weight 120 The SUS plate 140 of the wear resistance test apparatus 100 includes a SUS plate 140 reciprocated on the base 101 and a cam motor 150 reciprocating the SUS plate 140 by the cam loader 155. The electromagnetic wave shielding film 10 is attached to the insulation layer by using a double-sided adhesive tape, and then reciprocated 1500 times under a condition of a reciprocating distance of 40 mm with a friction member 130 acting on a load of 500 g. Then, the presence of scratches or wear on the surface of the insulating layer (2) was visually determined to determine the degree of wear as follows, and the results are shown in Table 2 using the following symbols.

○: no change in the surface of the insulating film (good)

△: scratch marks on some film surfaces

X: The insulating layer is worn and the lower conductive adhesive layer is exposed (defect).

(2) step resistance

3 is a diagram illustrating the step resistance measurement specimen 200.

As shown in FIG. 3, the CCL terminal 220 having a width of 5 mm and a length of 30 mm having a diameter of 1 mm and a hole 223 inscribed in the cover layer layer 210 is placed side by side so that the distance between holes 223 is 50 mm. After disposing the stepped portion 230 between the 220, and then welded so as to cover the conductive adhesive layer 3 of the electromagnetic wave shielding film 10 having a width of 10mm, and cured at 160 ℃ for 1 hour to measure the step resistance Specimen 200 was prepared. Then, the resistance between the CCL terminals 220 was measured using the tester 20. The step portion 230 may be variously modified to 50, 100, 200, 400㎛, and the like.

(3) Flexibility

4 is a diagram illustrating the flexibility test apparatus 300.

A test piece 300 for measuring flexibility was prepared by welding the cover layer side of the CCL terminal 220 having a circuit pattern having a width of 75 μm and a length of 80 mm to cover the conductive adhesive layer of the electromagnetic wave shielding film and curing at 160 ° C. for 1 hour. It was.

As shown in FIG. 4, after the specimen is mounted on the SUS plate 140 reciprocated from the upper portion of the base 101, the cam rod 155 and the cam motor are maintained with a bending radius of 1.0 mm. After driving the SUS plate 140 at a reciprocating distance of 20 mm and 60 reciprocating speeds per second using the 150, the electric resistance according to the number of round trips is measured using a tester 20 (in this case, a milliohm meter). The number of round trips at the time exceeding 20% of the initial resistance value was evaluated by the bending performance of the electromagnetic wave shielding film 10, and the results are shown in Table 2 using the following symbols.

○: More than 300,000 times (good)

△: less than 100,000-300,000 times

×: less than 100,000 times (defective)

(4) adhesion

The electromagnetic wave shielding film 10 is welded so that the conductive adhesive layer 3 is in contact with the copper foil surface of the single-sided CCL terminal 220 (copper foil 1 oz / PI film 1 mil) and cured at 160 ° C. for 1 hour to measure adhesion. Specimen was prepared. After cutting to 10 mm in width and 50 mm in length, the strength was measured while peeling the electromagnetic shielding film 10 at a 90 ° angle with a tensile strength tester to measure the adhesive force of the adhesive film.

(5) Heat resistance

In order to evaluate the soldering heat resistance of the electromagnetic shielding film 10, the specimen attached to the cross section CCL was prepared in the same manner as the specimen for measuring the adhesive force, cut into 20 mm width and 20 mm length, floated in a 280 ° C. bath for 30 seconds, and then bonded. The deformation and bubble generation on the film surface were evaluated based on the following criteria.

○: No bubble formation or surface deformation (good)

△ no bubble generation but surface deformation observed

×: Both bubble formation and surface deformation are observed (defect)

(6) flame retardant

After the specimen attached to 2mill Kapton PI (DuPont) was prepared in the same manner as the specimen for measuring the adhesive force, cut to 50mm in width and 200mm in length and evaluate the flame retardancy according to the UL 94 VTM-0 standard. It is shown in Table 2.

When flame retardant VTM-0 specification is met: 0 (good)

If flame retardant VTM-0 specification is not met: X (defective)

Ο: Very good, △: Good, X: Poor, nm: Not measurable

As can be seen from Table 2, the electromagnetic wave shielding film 10 prepared in Examples 1 to 4 shows that the step resistance increases as the conductive metal powder content decreases. In addition, in the case of using PPS as the insulating layer in Comparative Example 1, it is found that the flexibility, abrasion resistance, and the flame retardancy are weak.In the case of using the epoxy resin as the insulating layer in Comparative 2, heat resistance, abrasion, and flame retardancy are weak, and electromagnetic waves are more than 100 μm in the step. There was breakage of the shielding film, so the step resistance could not be measured. In Examples 2 to 4, when the polyimide film is used as the insulating layer, it can be confirmed that all of them show good characteristics.

In addition, a printed circuit board with an electromagnetic wave shielding film according to an embodiment of the present invention, a carrier film (Release Protection Film); and an insulating layer (Substrate Layer) provided with a polyimide film on one side of the carrier film; The circuit pattern of the printed circuit board may include an electromagnetic shielding film including a primer layer provided on a surface opposite to a surface of the carrier film opposite to a surface of the carrier film and a conductive adhesive layer provided on the surface of the primer layer. It is produced by being attached to the formed surface by a hot press process.

5 is a method of manufacturing a printed circuit board with an electromagnetic plate shielding film according to an embodiment of the present invention, an insulating layer forming step (S10) and a primer layer forming step (S20) for forming a primer layer (3). And after the laminating step S40 of laminating the conductive adhesive layer 4 and the primer layer 3 formed by the conductive adhesive layer forming step S30 to face each other, the conductive adhesive layer 4 is formed on the printed circuit board. It is characterized in that it comprises a; hot pressing step (S50) for performing a hot press after mounting the press machine to be bonded to the surface on which the circuit pattern is formed.

In addition, the method of manufacturing a printed circuit board with an electromagnetic plate shielding film according to another embodiment of the present invention as shown in FIG. After the primer layer forming step (S120) and the conductive adhesive layer forming step (S130) is performed, the conductive adhesive layer (4) is mounted on the press to be bonded to the surface on which the circuit pattern of the printed circuit board is formed and then hot press is performed. Hot pressing process (S140); characterized in that comprises a.

10: electromagnetic wave shielding film, 1: carrier film, 2: insulating layer 3: primer layer
4: conductive adhesive layer, 5: release film, 100: wear resistance test apparatus
200: step resistance measurement test piece, 220: CCL terminal, 223: hole, 230: step part
300: flexibility test device

Claims (9)

delete An insulating layer; and a primer layer on the insulating layer; and a conductive adhesive layer formed by coating and drying a conductive adhesive composition. 4'-oxydianiline (ODA) and p-phenylene diamine (p-PDA) mixtures and dianhydrides with pyromellitic dianhydrides (PMDA) and 3,3 ', 4,4'-biphenyltetracarboxyl In the electromagnetic wave shielding film which is a polyimide film of molecular weight 5,000-1,000,000 which mixed the mixture of lick dianhydride (BPDA) by 1 to 1, and which imidates and arranges linearly irregularly;
The insulating layer has a thickness of 1 to 15㎛ electromagnetic shielding film, characterized in that.
delete delete delete delete delete An insulating layer forming step (S10) of forming an insulating layer 2 by applying a composition solution for an insulating layer to a release film and drying and attaching a carrier film to one surface, and removing the release film;
A primer layer forming step (S20) of applying a primer solution composition prepared by mixing and diluting a primer resin composition in a solvent on an insulating layer and drying to form a primer layer (3);
A conductive adhesive layer forming step (S30) of adding a binder resin composition and a mixed conductive filler to a solvent and applying the composition solution for the conductive adhesive layer 4 prepared by stirring to a release film and drying to form the conductive adhesive layer 4 ;Wow,
And a laminating step (S40) of laminating the conductive adhesive layer (4) and the primer layer (3) to face each other.
After coating the composition solution for the insulating layer on the release film and dried, attaching a carrier film on one surface, removing the release film to form an insulating layer (2) to form an insulating layer (S110); And,
A primer layer forming step (S120) of applying a primer solution composition prepared by mixing and diluting a primer resin composition to a solvent on an insulating layer and drying to form a primer layer (3);
A conductive adhesive for adding a binder resin composition and a mixed conductive filler to a solvent and stirring the composition solution for the conductive adhesive layer 4 prepared on the primer layer 3 and drying to form the conductive adhesive layer 4. Layer forming step (S130); electromagnetic wave shielding film manufacturing method comprising a.

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