KR20210025390A - Coverlay film and manufacturing method thereof, flexible metal composite substrate comprising the same - Google Patents

Abstract

The present invention provides a coverlay film, a manufacturing method thereof, and a flexible metal composite substrate having the coverlay film, wherein the coverlay film comprises: a thermoplastic polymer film having a melting point (Tm) of 300°C or less; and an adhesive layer formed on the thermoplastic polymer film. In the present invention, the coverlay film includes the thermoplastic polymer having the melting point (Tm) or 300°C or less, so that the cost is reduced compared to a conventional polyimide (PI)-based film, overall characteristics are excellent, and safety is improved. Accoridngly, the flexible metal composite substrate can be applied to an electric vehicle battery module.

Description

Coverlay film and its manufacturing method, a flexible metal composite substrate including the coverlay film TECHNICAL FIELD [COVERLAY FILM AND MANUFACTURING METHOD THEREOF, FLEXIBLE METAL COMPOSITE SUBSTRATE COMPRISING THE SAME}

The present invention is a coverlay _{film that can be applied to battery modules of electric vehicles by providing a thermoplastic polymer film having a melting point (T m} ) of 300°C or less, thereby reducing cost compared to conventional polyimide (PI)-based films and improving safety and durability. And a method for manufacturing the same, and to a flexible metal composite substrate having the coverlay film.

An electric vehicle (EV) was developed as a countermeasure against exhaust gas, and has the advantage of low noise and no exhaust gas at all. Such an electric vehicle drives an electric motor with electric energy and drives it by rotating a wheel through a power transmission device, so a high-power and large-capacity battery must be used to supply the power required for the driving force.

A battery provided in a medium- to large-sized device such as a vehicle is a medium-to-large battery module electrically connected to a plurality of battery cells. In this way, a plurality of mechanical couplings and electrical connections are required to construct a medium-sized battery module, such as one battery pack, using a plurality of cells, and a printed circuit board (PCB) for each module constituting the battery pack This should be built.

On the other hand, a printed circuit board (PCB) is generally constructed in a form in which a polyimide (PI)-based insulating film is laminated on one or both sides of a copper foil layer, and the purpose is to protect the circuit pattern of the copper foil layer if necessary. As a result, a coverlay film in which an adhesive and an insulating film are laminated is also used. Polyimide resins are often used as the insulating film. These polyimide (PI) films are heat-resistant polymers having a glass transition temperature (Tg) of 300°C or higher, but are burned and carbonized when the temperature rises abnormally. These carbides may remain in the battery fluid of a vehicle and cause safety problems such as fire and explosion.

The present invention was devised to solve the above-described problems, and by adopting a thermoplastic polymer film having a melting point (T _{m ) or a predetermined melting point (T m) instead of a conventional polyimide (PI) film, safety} It is a technical task to provide a coverlay film capable of improving and reducing costs, and an interconnection composite substrate applicable to a vehicle battery including the same.

In order to achieve the above technical problem, the present invention is a _{thermoplastic polymer film having a melting point (T m} ) of 300°C or less; And it provides a coverlay film comprising an adhesive layer formed on the thermoplastic polymer film.

According to one embodiment of the present invention, the thermoplastic polymer film may have a glass transition temperature (Tg) of 250°C or less.

According to one embodiment of the present invention, the thermoplastic polymer film may satisfy at least one of the following physical properties (i) to (iv). Specifically, the coverlay film includes: (i) a density ^{of 1.15 g/cm 3} or more, 1.42 g/cm ^{3 or less, measured according to ASTM D 1505;} (ii) 75% or more elongation at break measured according to ASTM D 882; (iii) 2% or less of heat shrinkage (150° C., 30 minutes) in the longitudinal direction and the width direction of the film; And (iv) a moisture absorption rate of less than 1.0%.

According to an embodiment of the present invention, the thermoplastic polymer film is polyethylene naphthalate (PEN), polyethylene terephtalate (PET), polycyclohexadimethylene terephtalate (PCT), polytrimethylene Terephthalate (polytrimethyleneterephtalate, PTT), polybutyleneterephtalate (PBT), polytrimethylene naphthalate (PTN), polybutylene naphthalate (PBN), polycyclohexane dimethylene naphthalate ( It may include at least one polyester-based polymer selected from the group consisting of polycyclohexadimethylene naphthalate, PCN), and polycyclohexadimethylene cyclohexadimethylcarboxylate (PCC).

According to an embodiment of the present invention, the thermoplastic polymer film is from the group consisting of polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), and polyether sulfone (PES). It may include at least one selected aromatic sulfone polymer, or polyetheretherketone (PEEK).

According to one embodiment of the present invention, the adhesive layer is a thermosetting resin; And it may be formed from an adhesive composition comprising at least one selected from the group consisting of a thermoplastic resin, a curing agent and an inorganic filler.

According to one embodiment of the present invention, the thermosetting resin may include 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 an embodiment of the present invention, the thermoplastic resin is acrylonitrile-butadiene rubber (NBR), styrene butadiene rubber (SBR), acrylonitrile-butadiene-styrene rubber (ABS), carboxyl-terminated butadiene acrylic It may include at least one selected from the group consisting of ronitrile rubber (CTBN), polybutadiene, and styrene-butadiene-ethylene resin (SEBS).

According to one embodiment of the present invention, the mixing ratio of the thermosetting resin and the thermoplastic resin may be 20 to 80: 80 to 20 weight ratio based on 100 parts by weight of the polymer resin.

According to one embodiment of the present invention, the adhesive layer may further include at least one of a silane coupling agent, a dispersant, a flame retardant filler, and a curing accelerator.

According to one embodiment of the present invention, it may further include a release layer disposed on the adhesive layer.

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

According to an embodiment of the present invention, the thickness of the thermoplastic polymer film may be 12 to 125 μm, and the thickness of the adhesive layer may be 5 to 100 μm.

In addition, the present invention, the melting point (T _m ) is a first thermoplastic polymer film of 300 °C or less; And a first coverlay film including a first adhesive layer. A second thermoplastic polymer film having a melting point (T _m ) of 300° C. or less; And a second coverlay film including a second adhesive layer. And a metal layer disposed between the first coverlay film and the second coverlay film, and provides a flexible metal composite substrate in which they are integrally laminated.

According to an embodiment of the present invention, one surface of the metal layer may be in close contact with the first adhesive layer, and the other surface may be in close contact with the second adhesive layer.

According to one embodiment of the present invention, a peel strength value of the first adhesive layer with respect to the metal layer is 1.0 kgf/cm or more, and a peel strength value of the first adhesive layer with respect to the first thermoplastic polymer film is 1.0 kgf/cm It can be more than that.

According to an exemplary embodiment of the present invention, the metal layer may include one selected from the group consisting of copper (Cu), a copper alloy, aluminum (Al), and an aluminum alloy.

According to one embodiment of the present invention, the metal layer may be a copper foil or an aluminum foil having an average roughness (Ra) of 0.1 μm or less on both sides.

According to one embodiment of the present invention, the thickness of the metal layer may be 9 to 105 μm.

According to an exemplary embodiment of the present invention, the metal layer may include at least one circuit pattern patterned in a predetermined shape.

In addition, the present invention provides a method of manufacturing the above-described coverlay film. In one embodiment of the manufacturing method, (i) preparing a thermoplastic polymer film; (ii) forming an adhesive layer by coating and drying a thermosetting adhesive composition on the thermoplastic polymer film; And (iii) arranging the adhesive layer and the release layer of the thermoplastic polymer film to face each other and then integrating through continuous roll lamination.

According to one embodiment of the present invention, the roll lamination process of step (iii) may be carried out at a temperature equal to or _{higher than the glass transition temperature (Tg) and lower than the melting point (T m) of the thermoplastic polymer.}

_{According to an embodiment of the present invention, by employing a thermoplastic polymer film having a predetermined melting point (T m} ) instead of a conventional thermosetting polyimide (PI) film, it is possible to exhibit a cost reduction effect and a safety improvement effect. .

In addition, in the present invention, by optimally mixing the composition of the adhesive layer constituting the coverlay film, excellent flame retardancy, adhesiveness, heat resistance, and improved crack characteristics can be simultaneously secured. Accordingly, the coverlay film and the flexible metal composite substrate having the same according to the present invention can be usefully applied to a battery of an electric vehicle.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic cross-sectional view of a coverlay film according to an embodiment of the present invention.
2 is a schematic cross-sectional view of a coverlay film according to another embodiment of the present invention.
3 is a schematic cross-sectional view of a flexible metal composite substrate according to an embodiment of the present invention.
4 is a diagram schematically showing a manufacturing process of a flexible metal composite substrate according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the present invention is described below. It is not limited to examples. In this case, the same reference numerals refer to the same structure throughout the present specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, so the present invention is not necessarily limited to the illustrated bar. In the drawings, the thicknesses are enlarged in order to clearly express various layers and regions. In addition, in the drawings, for convenience of description, the thicknesses of some layers and regions are exaggerated.

In addition, throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. In addition, throughout the specification, the term "above" or "on" means not only the case that is located above or below the target part, but also includes the case where there is another part in the middle, and must always refer to the direction of gravity. It does not mean that it is located above the standard. In addition, in the present specification, terms such as "first" and "second" do not represent any order or importance, but are used to distinguish components from each other.

In addition, throughout the specification, the term "on a plane" means when the target part is viewed from above, and when "cross-sectional" refers to when the target part is viewed from the side when a vertically cut section is viewed from the side.

<Coverlay film>

According to an embodiment of the present invention, a coverlay film including a thermoplastic polymer film having a _{predetermined melting point (T m) is provided.}

Here, the coverlay film refers to a composite film in which an adhesive is coated on an insulating film, or a release film in addition to the composite film. Such a coverlay film is in close contact with a metal layer of a flexible metal composite substrate to be described later, and is specifically used to protect and insulate an exposed circuit pattern of an etched flexible printed circuit board (FPCB).

1 is a cross-sectional view schematically showing the structure of a coverlay film 100 according to an embodiment of the present invention.

Referring to FIG. 1, the coverlay film 100 includes a thermoplastic polymer film 10; It includes an adhesive layer 20 formed on the film. Hereinafter, each configuration of the coverlay film 100 will be described in detail.

Thermoplastic polymer film

In the coverlay film 100 of the present invention, the thermoplastic polymer film 10 is a base film of the coverlay film 100, which serves as a support for coating the adhesive layer 20 and is a layer that functions as an insulating function. . In particular, in the case of forming a flexible metal composite substrate (300 in FIG. 3) by being disposed adjacent to the metal layer (40 in FIG. 3), the metal layer 40 is in close contact with the metal layer 40 while protecting it to be insulated from the outside. It exhibits flexibility, heat resistance and adhesion.

The thermoplastic polymer film 10 has a melting point (T _m ) or a conventional polymer in the art having a melting point (T _m ) of 300°C or less can be used without limitation, and specifically, while having a melting point (Tm), the glass transition temperature High thermoplastic polymers capable of (Tg) are preferred. Here, the melting point (T _m ) is based on the melting point measured according to ASTM E 794. For example, the thermoplastic polymer film 10 may be composed of a thermoplastic polymer having a melting point (Tm) of 300°C or less and a glass transition temperature (Tg) of 250°C or less, and specifically, a melting point (Tm) It is 150 to 280°C, and a glass transition temperature (Tg) of 70 to 200°C may be used.

In other words, polyimide (PI) resin, which is conventionally used as an insulating film, is a material with heat resistance, but is a kind of thermosetting polymer, so when the temperature of the battery rises abnormally, it burns to generate carbides. It may cause safety problems such as explosion or explosion. In contrast, the present invention, the melting point (T _m) with or melting point (T _m) is the use of thermoplastic polymers than 300 ℃, by melt by itself caused a short circuit (short) in the above-described abnormal temperature fire or explosion It can be fundamentally prevented.

For another embodiment, the moisture absorption rate of the thermoplastic polymer film 10 may be less than 1.0%, preferably less than 0.4%. Here, the moisture absorption rate may be measured according to IPC-TM-650 2.6.2. Conventional polyimide (PI) films have a relatively high moisture absorption rate, so when applied to a vehicle exposed to an external environment, problems such as malfunction may occur. In contrast, in the present invention, by using a thermoplastic polymer having a low moisture absorption rate, the above-described problem is not caused even when applied to a vehicle exposed to an external environment.

The thermoplastic polymer film 10 may include at least one of conventional polyester-based polymers, aromatic sulfone polymers, and other thermoplastic polymers known in the art that satisfy the above-described physical properties. This polyester resin is polymerized by mixing and heating a dicarboxylic acid and a diol and blowing off the resulting water under reduced pressure, and not only has a colorless and transparent property among polymer resins, but also has excellent mechanical properties, heat resistance, and chemical resistance.

Non-limiting examples of polyester-based thermoplastic polymers that can be used include polyethylene naphthalate (PEN), polyethylene terephtalate (PET), polycyclohexadimethylene terephtalate (PCT), and polytrimethylene. Terephthalate (polytrimethyleneterephtalate, PTT), polybutyleneterephtalate (PBT), polytrimethylene naphthalate (PTN), polybutylene naphthalate (PBN), polycyclohexanedimethylene naphthalate ( polycyclohexadimethylene naphthalate, PCN), and polycyclohexadimethylene cyclohexadimethylcarboxylate (PCC).

In addition, non-limiting examples of the aromatic sulfone polymer that can also be used include polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), and polyether sulfone (PES) from the group consisting of It may include at least one selected. And polyetheretherketone (PEEK) can be used. Preferred examples of the thermoplastic polymer film 10 include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycyclohexanedimethylene terephthalate (PCT), polyphenylsulfone (PPSU), or a mixture thereof. have.

The thermoplastic polymer film 10 may be in the form of a self-supporting film or sheet, or may be in the form of a coating layer formed on the film or sheet. In addition, it may have a single-layer structure composed of one insulating film, or may have a multilayer structure in which two or more types of insulating films different from each other are stacked. For example, the thermoplastic polymer film 10 may be _{a thermoplastic polymer film having the above-described melting point (T m} ) or a second thermoplastic polymer base film coated with a first thermoplastic polymer layer. In this case, the first and second thermoplastic polymers may be the same or different from each other.

The thermoplastic polymer film 10 secures excellent mechanical properties and durability in the normal temperature range, while reducing the difference in the coefficient of thermal expansion (CTE) from the metal layer 40 to be described later, thereby reducing the bending properties and low expansion when applied to the final product. , In order to effectively improve mechanical properties and low stress, a conventional inorganic filler known in the art may be further included.

Non-limiting examples of inorganic fillers that can be used include silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium dioxide, antimony oxide, glass fiber, aluminum borate, barium titanate, strontium titanate, calcium titanate. , Magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, boron nitride, silicon nitride, talc, and mica. The amount of the inorganic filler used is not particularly limited, and may be appropriately adjusted in consideration of the above-described heat resistance and mechanical properties. The average particle diameter of the inorganic filler can be appropriately adjusted within a conventional range known in the art, and is not particularly limited. For example, it may be in the range of 0.1 to 10 μm.

Since the thermoplastic polymer film 10 is mounted inside a battery of a vehicle, it may be a conventional transparent polymer film or a colored polymer film in the art. At this time, the colored polymer film is in a colored form, or includes a white or black form. Here, the material usable as a colorant is not particularly limited, for example, one or more materials selected from the group consisting of titanium dioxide, carbon black, cobalt oxide, Fe-Mn-Bi black, iron oxide black, and mica iron oxide. Can be lifted. Depending on the type of the colorant, the thermoplastic film may have a color such as white, black, dark gray, dark brown, or dark brown.

In one embodiment of the present invention, the thermoplastic polymer film 10 is provided on the coverlay film 100 to provide mechanical properties, heat resistance, and durability, at least one of the following properties (i) to (iv). It may be to satisfy, specifically two or more, more specifically may be to satisfy all. For example, (i) the density measured according to ASTM D 1505 may be 1.15 g/cm ³ or more and 1.42 g/cm ^{3 or} less, and specifically 1.20 to 1.40 g/cm ³ . (ii) Elongation at break measured according to ASTM D 882 may be 75% or more, and specifically 77 to 200%. (iii) In the longitudinal direction (MD, machine direction) and transverse direction (TD, transverse direction) of the film, the heat shrinkage (heat shrinkage, 150° C.×30 minutes) may be 2% or less, and specifically 1.5%. I can. (iv) The moisture absorption rate may be less than 1.0%, specifically 0.4% or less. By satisfying the above-described physical properties, it is possible to improve the physical stability of the product.

The thickness of the thermoplastic polymer film 10 can be appropriately adjusted in consideration of insulation, handling properties of the film, physical stiffness, coefficient of thermal expansion, thinning of the substrate, insulation, high-density wiring, and the like. For example, it may be 12 to 125 µm, preferably 12 to 75 µm, more preferably 25 to 50 µm. If necessary, the surface of the thermoplastic polymer film 10 may have been subjected to surface treatment such as mat treatment or corona treatment.

Adhesive layer

In the coverlay film 100 of the present invention, the adhesive layer 20 exhibits adhesion, heat resistance, and interlayer adhesion with the adjacent thermoplastic polymer film 10. In addition, when the flexible metal composite substrate 300 is formed by being disposed opposite to the metal layer 40, excellent adhesion to the metal layer 40 may be exhibited.

The adhesive layer 20 may be used without limitation, a conventional thermosetting adhesive component known in the art, for example, a thermosetting resin; And it may be formed from an adhesive composition comprising at least one selected from the group consisting of a thermoplastic resin, a curing agent and an inorganic filler.

Non-limiting examples of thermosetting resins that can be used include epoxy resins, polyurethane resins, phenolic resins, melamine resins, silicone resins, urea resins, vegetable oil-modified phenolic resins, xylene resins, guanamine resins, diallylphthalate resins, vinyl esters. It may be one or more selected from the group consisting of resins, unsaturated polyester resins, furan resins, polyimide resins, cyanate resins, maleimide resins, and benzocyclobutene resins. Preferably, it is an epoxy resin, a phenol resin, a melamine resin, a silicone resin, a urethane resin, or a urea resin.

Double epoxy resin is preferred because of its excellent reactivity and heat resistance, and more preferably a halogen-based epoxy resin containing a halogen element such as bromine (Br) in the molecule. Here, the content of halogen contained in the halogen-based epoxy resin is not particularly limited, and may be, for example, 10 to 80% in the molecule, and specifically 30 to 60%.

The epoxy resin may use a conventional epoxy resin known in the art 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/F/S type resins, novolac type epoxy resins, alkylphenol novolac type epoxy resins, polyfunctional phenol novolak type epoxy resins, biphenyl type, Aralkyl (Aralkyl) type, naphthol (Naphthol) type, dicyclopentadiene type, or a mixture thereof.

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

In one embodiment of the present invention, the thermosetting resin includes a halogen-based first epoxy resin and a non-halogen-based second epoxy resin; And at least one of the polyfunctional type phenol novolak type third epoxy resin may be mixed, and all of the above-described first to third epoxy resins may be included. At this time, the use ratio of the first epoxy resin, the second epoxy resin, and the third epoxy resin is not particularly limited, and may be, for example, a weight ratio of 1: 0 to 0.5: 0 to 0.5.

For another embodiment of the present invention, at least one of the epoxy resins constituting the adhesive layer 20 may include an epoxy resin having a polydispersity index (PDI) of 2 or less.

The polydispersity index (PDI) is a standard (measure) representing the area (width) of the molecular weight distribution of a polymer, and is defined as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). Specifically, the larger the polydispersity index (PDI), the wider the molecular weight distribution, and the closer to 1, the closer it is to be interpreted as a single molecular weight polymer with good physical properties.

At least one of the plurality of epoxy resins constituting the adhesive layer 20 of the present invention has a polydispersity index (PDI) of 2.0 or less (preferably 1 to 1.7, more preferably 1.1 to 1.5) of a narrow molecular weight distribution. It may be a narrow dispersity (ND) epoxy resin. That is, the ND epoxy resin having a narrow molecular weight distribution contains a relatively high molecular weight polymer (eg, High Mw species) and a low molecular weight polymer (eg, Oligomer), and has a uniform molecular weight distribution. Since the ND epoxy resin having a uniform molecular weight distribution as described above has a higher degree of curing than that of a general epoxy resin due to less side reaction, when the adhesive layer 20 is formed with an epoxy resin composition containing such an ND epoxy resin, the free volume is reduced. A minimized resin layer is obtained, and as a result, a resin layer having high adhesion and low water absorption is obtained. In addition, since ND epoxy resin exhibits high purity due to low content of impurities such as ions and side reaction products generated during the synthesis of epoxy resin, migration is minimized when a resin layer is formed with an epoxy resin composition containing such ND epoxy resin. The resulting adhesive layer 20 is obtained. In addition, as the ND (narrow dispersity) epoxy resin is used, the viscosity of the epoxy resin composition decreases, which in turn can obtain an effect of improving the wetting property and adhesion of the adhesive layer 20 formed of the epoxy resin composition.

Meanwhile, a multilayer flexible circuit board is generally manufactured by laminating a plurality of metal laminates or printed circuit boards and bonding them to each other. In this case, the adhesive layer provided on the metal laminate has high adhesion as well as the movement of conductive ions present in the circuit layer. Preventing migration resistance is also required. This is because, if the conductive ions present in the circuit layer move freely, a short circuit is caused, and the reliability of the metal laminate or a multilayer flexible printed circuit board including them is degraded.

In contrast, since the adhesive composition according to the present invention exhibits high purity due to low ionic content such as ^{K +} , NH ^{4 +} , Na ⁺ , and Cl ^{-including ND epoxy resin, the adhesive layer 20 formed therefrom is very} It can show low absorption rate and ion content. When the adhesive layer 20 having a low ion content is provided as an adhesive layer of the flexible metal composite substrate 300 to be described later, the ^{migration of conductive ions (eg, Cu 2+} ) to the adjacent metal layer 40 is prevented. Minimized, it is possible to provide a multilayer flexible metal composite substrate having excellent migration resistance and high reliability.

For another embodiment of the present invention, the plurality of epoxy resins constituting the adhesive layer 20 may be mixed with at least two epoxy resins having different polymerization degrees (n) or epoxy equivalents (EEW).

Specifically, epoxy equivalent weight (EEW) epoxy resin has a low melt viscosity and good wettability in adhesion, and high equivalent epoxy resin (EEW) has plasticity itself, so that the bendability of the laminate (bending processability) And it is possible to improve molding properties such as punchability. Accordingly, when the adhesive layer 20 is formed by including at least two epoxy resins having a degree of polymerization (n) or an equivalent difference, high adhesiveness, excellent moisture resistance reliability, and excellent moldability may be exhibited. For example, the adhesive layer 20 may include a first epoxy resin having an epoxy equivalent (EEW) of 250 to 430 g/eq; A second epoxy resin having an epoxy equivalent (EEW) of 440 to 800 g/eq; And a third epoxy resin having an epoxy equivalent weight (EEW) of 100 to 240 g/eq.

The content of the thermosetting resin is not particularly limited, and for example, may be 30 to 70 parts by weight based on the total weight (eg, 100 parts by weight) of the adhesive composition, and preferably 40 to 65 parts by weight. When it has the above-described content range, sufficient adhesion and excellent heat resistance can be secured.

When the adhesive layer 20 according to the present invention further contains a thermoplastic resin, effects such as improved adhesion, improved flexibility, and thermal stress relaxation may be obtained.

As the thermoplastic resin, conventional thermoplastic resins, thermoplastic rubbers, or both known in the art may be used. Non-limiting examples of thermoplastic resins that can be used include acrylonitrile-butadiene rubber (NBR), styrene butadiene rubber (SBR), acrylonitrile-butadiene-styrene rubber (ABS), carboxyl-terminated butadiene acrylonitrile rubber. (CTBN), polybutadiene, styrene-butadiene-ethylene resin (SEBS), acrylic acid and/or methacrylic acid having a side chain of 1 to 8 carbon atoms Ester resin (acrylic rubber), or a mixture of one or more of them. Preferably, it may be an acrylic rubber.

It is preferable that the above-described thermoplastic resin, specifically rubber, contains a functional group capable of reacting with an epoxy resin which is a thermosetting resin. For a specific example, 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, an isocyanate group, a vinyl group, and a silanol group. Since such a functional group forms a strong bond with the epoxy resin, heat resistance is improved after curing, 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 relaxation effect of thermal stress. It is more preferable to contain a carboxyl group as a functional group capable of reacting.

The content of the thermoplastic resin is not particularly limited, and for example, may be 1 to 35 parts by weight, and preferably 5 to 30 parts by weight based on the total weight of the adhesive composition. If it is out of the above range, sufficient adhesiveness may not be obtained, and heat resistance may be lowered.

For example, the content of the polymer resin constituting the adhesive layer 20 may be 50 to 90 parts by weight, preferably 60 to 90 parts by weight based on the total weight (eg, 100 parts by weight) of the adhesive layer. It may be 85 parts by weight. When a thermosetting resin and a thermoplastic resin are mixed as the polymer resin, the mixing ratio of the thermosetting resin and the thermoplastic resin may be 20 to 80: 80 to 20 weight ratio based on 100 parts by weight of the polymer resin, and preferably 50 ~80: It may be a 20-50 weight ratio.

In the present invention, a conventional curing agent known in the art may be used without limitation, and may be appropriately selected and used according to the type of epoxy resin to be used. Non-limiting examples of the curing agent that can be used include imidazole-based, phenol-based, anhydride-based, dicyanamide-based, and aromatic polyamine curing agents. Non-limiting examples of the curing agent that can be used include phenolic curing agents such as phenol novolac, cresol novolac, bisphenol A novolac, and naphthalene type; There are polyamine-based curing agents such as metaphenylenediamine, diaminodiphenylmethane (DDM), and diaminodiphenylsulfone (DDS), and these may be used alone or in combination of two or more. The content of the curing agent is not particularly limited, and may be, for example, 0.1 to 10 parts by weight based on the total weight (100 parts by weight) of the adhesive composition.

In addition, the epoxy resin composition of the present invention may further include a curing accelerator to increase the curing reaction rate. Such a curing accelerator is not particularly limited as long as it is a material known in the art, but non-limiting examples include tertiary amines such as benzyldimethylamine, triethanolamine, triethylenediamine, dimethylaminoethanol, and tri(dimethylaminomethyl)phenol; Imidazole series such as 2-methylimidazole and 2-phenylimidazole; Organic phosphine series such as triphenylphosphine, diphenylphosphine, and phenylphosphine; And tetraphenyl boron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. The content of the curing accelerator included in the epoxy resin composition is not particularly limited, but considering curability, etc., the curing accelerator is preferably included in an amount of 0.001 to 0.5 parts by weight based on 100 parts by weight of the total of the thermosetting resin and the curing agent.

In the present invention, conventional inorganic fillers known in the art may be included. Non-limiting examples of the inorganic fillers that can be used include silicas such as natural silica, fused silica, amorphous silica, crystalline silica, and the like; Boehmite, alumina, aluminum hydroxide [Al(OH) ₃ ], talc, spherical glass, calcium carbonate, magnesium carbonate, magnesia, clay, calcium silicate, titanium oxide, antimony oxide, glass fiber, boric acid Aluminum, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, boron nitride, silicon nitride, talc, mica, and the like. These inorganic fillers may be used alone or in combination of two or more.

The size of the inorganic filler is not particularly limited, and the average particle diameter may range from 0.5 to 10 μm. In addition, the content of the inorganic filler is not particularly limited, and may be, for example, 0 to 35 parts by weight based on the total weight (100 parts by weight) of the adhesive composition, and specifically 5 to 30 parts by weight.

The adhesive layer 20 according to the present invention may further include at least one of a silane coupling agent, a dispersant, a flame retardant filler, and a curing accelerator.

A silane coupling agent known in the art may be used without limitation, and is preferably a silane coupling agent having an epoxy group. Non-limiting examples of the epoxy group silane coupling agent that can be used include 3-(glycidyloxy)propyl)trimethoxysilane, 3-(glycidyloxy)propyltriethoxysilane, 2-(3,4-epoxy Cyclohexyl)ethyl trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl triethoxysilane, epoxypropoxypropyl trimethoxysilane, and the like can be used. The above-described components may be used alone or in combination of two or more. The content of the silane coupling agent is not particularly limited, for example, it may be more than 0, 5 parts by weight or less based on the total 100 parts by weight of the adhesive layer 20, preferably 0.3 to 1.5 parts by weight.

The dispersant plays a role of dispersing each material constituting the composition for forming an adhesive layer and preventing re-aggregation through distance maintenance, thereby expressing the uniform physical properties of the adhesive layer. The dispersant may be a conventional one known in the art, and examples include a high molecular weight block copolymer type dispersant. Preferably, a wettable dispersant is used. Such a wettable dispersant can further improve the dispersibility of an inorganic filler or filler to be mixed.

The usable wetting dispersant is not particularly limited as long as it is a conventional dispersion stabilizer used in the paint field. As an example, BYK's Disperbyk-110, 111, 161, 180, etc. are mentioned. The above-described wettability dispersant may be used alone, or two or more types may be appropriately used in combination. The content of the dispersant is not particularly limited, for example, it may be greater than 0, 5 parts by weight or less, preferably 0.1 to 2 parts by weight based on the total 100 parts by weight of the adhesive layer.

In addition, in the present invention, in order to impart flame retardancy to the adhesive layer 20, at least one flame retardant filler may be further included. Here, the type of the flame retardant filler is not particularly limited, but due to the addition of the flame retardant filler, the flexible composite substrate 100 according to the present invention is provided with flame retardancy that passes the vertical combustion test (VW-1 test) of the UL standard. desirable.

More specifically, as the flame retardant filler, at least one selected from the group consisting of halogen flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, metal-based flame retardants and antimony-based flame retardants may be used, and preferably one or more and 7 or less are mixed. It can be used, and more preferably, 3 or more and 5 or less compounds may be mixed and used. Non-limiting examples of flame retardants that can be used include chlorinated flame retardants such as chlorinated paraffin, chlorinated polyethylene, chlorinated polyphenyl, and perchloropentacyclodecane; Ethylenebispentabromobenzene, ethylenebispentabromodiphenyl, tetrabromoethane, tetrabromobisphenol A, hexabromobenzene, decabromobiphenyl ether, tetrabromophthalic anhydride, polydibromophenylene oxide, Brominated flame retardants such as hexabromocyclodecane and ammonium bromide; Triallyl phosphate, alkyl allyl phosphate, alkyl phosphate, dimethyl phosphonate, phosphonate, halogenated phosphonate ester, trimethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, octyldiphenyl phosphate, tricre Dyl phosphate, credylphenyl phosphate, triphenyl phosphate, tris (chloroethyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2,3-dibromopropyl) Phosphate, tris (bromochloropropyl) phosphate, sp (2,3 dibromopropyl) 2,3 dichloropropyl phosphate, bis (chloropropyl) monooctyl phosphate, polyphosphonate, polyphosphate, aromatic polyphosphate, di Phosphoric acid esters or phosphorus compounds such as bromoneopentyl glycol and tris(diethylphosphinic acid) aluminum; Polyols such as phosphonate type polyol, phosphate type polyol, and halogen element-containing polyol; Aluminum hydroxide, magnesium hydroxide, magnesium carbonate, antimony trioxide, antimony trichloride, zinc borate, antimony borate, boric acid, antimony molibuthenate, molybutene oxide, phosphorus-nitrogen compound, calcium-aluminum silicate, titanium dioxide, zirconium compound, tin compound , Dosonite, calcium aluminate hydrate, copper oxide, metal copper powder, calcium carbonate, metal powder or inorganic compounds such as barium metaborate; Nitrogen compounds such as melamine cyanurate, triazine, isocyanurate, urea, and guanidine; And other compounds such as silicone polymers, ferrocene, fumaric acid, and maleic acid. Among them, halogen-based flame retardants such as bromine-based flame retardants and chlorine-based flame retardants and phosphorus-based flame retardants are preferred, and phosphorus-based flame retardants are more preferred.

The content of the flame retardant filler is not particularly limited, and as an example, it is included in the range of 5 to 30 parts by weight, preferably 5 to 15 parts by weight, more preferably 5 to 10 parts by weight, based on the total weight of the adhesive layer 20. I can. When included in the above-described content, sufficient flame retardancy may be imparted to the adhesive layer 20, and excellent flexibility and elongation may be exhibited.

In one embodiment of the present invention, the thermosetting adhesive composition constituting the adhesive layer 20 includes 30 to 70 parts by weight of an epoxy resin based on 100 parts by weight of the composition; 1 to 35 parts by weight of a thermoplastic resin; 0.1 to 10 parts by weight of a curing agent (additive); And 0 to 30 parts by weight of an inorganic filler. Here, the epoxy resin can implement chemical resistance and flexibility, and the thermoplastic resin improves adhesion and flexibility, and exhibits thermal stress relaxation effects. In this case, the thermosetting adhesive composition may include an organic solvent, and the amount of the organic solvent may be in a range of the remaining amount to match the total 100 parts by weight of the composition.

In addition to the above-described components, the present invention provides a flame retardant generally known in the art as needed, other thermosetting resins or thermoplastic resins not described above, and oligomers thereof, as long as the intrinsic properties of the adhesive layer 20 are not impaired. Various polymers, solid rubber particles or ultraviolet absorbers, silane coupling agents, antioxidants, polymerization initiators, dyes, pigments, thickeners, leveling agents, antioxidants, masking agents, lubricants, processing stabilizers, plasticizers, foaming agents, reinforcing agents, coloring agents, fillers, Other additives such as granules, metal inert agents, and the like may be further included.

The thickness of the adhesive layer 20 is not particularly limited, and may be, for example, 5 to 100 µm, and preferably 25 to 50 µm.

2 is a cross-sectional view schematically showing a cross section of a coverlay film 200 according to another embodiment of the present invention.

In FIG. 2, the same reference numerals as in FIG. 1 denote the same members. Hereinafter, in the description of FIG. 2, contents overlapping with that of FIG. 1 are not described again, and only differences are described.

Referring to FIG. 2, the coverlay film 200 of the present invention is compared with FIG. 1 in which a thermoplastic polymer film 10 is laminated on one side of the adhesive layer 20, and the other side of the adhesive layer 20 It further includes a release layer (30). Specifically, the coverlay film 200 according to the embodiment of FIG. 2 includes an adhesive layer 20; A thermoplastic polymer film 10 disposed on one side of the adhesive layer 20; And a release layer 30 for protecting the adhesive layer 20 may be attached to the other surface of the adhesive layer 20, that is, a non-contact surface that does not contact the thermoplastic polymer film 10.

The release layer 30 may be a conventional one known in the art, and for example, may be any one of a release paper and a release polymer film (eg, a release PET film). This release layer 30 may be formed by laminating.

The release polymer film may be applied without limitation, such as a conventional plastic film known in the art. 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, and triacetylcellulose films. , Acetylcellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether Turketone film, polyethersulfone film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic resin film, norbornene resin film, cycloolefin resin film, and the like. These plastic films may be transparent or semitransparent, may be colored, or may be non-colored, and may be appropriately selected depending on the application.

The thickness of the release layer 30 is not particularly limited, and may be appropriately adjusted within a range known in the art. For example, it may be 12 to 200 µm, and specifically 25 to 150 µm.

The coverlay film 100 of the present invention configured as described above may have various thicknesses depending on the applied product, and is not particularly limited.

The coverlay film 100 may exhibit excellent adhesion, high heat resistance, and mechanical properties through the adoption of a thermoplastic polymer film having a controlled _{melting point (T m) and optimization of a binder used as an adhesive layer component.} In addition, it is possible to secure safety by configuring a flexible metal composite substrate applicable to a battery of an electric vehicle.

Manufacturing method of coverlay film

Hereinafter, a method of manufacturing a coverlay film according to an embodiment of the present invention will be described. However, it is not limited only by the following manufacturing method, and the steps of each process may be modified or selectively mixed and performed as necessary.

Specifically, as an example of manufacturing the coverlay film, (i) preparing a thermoplastic polymer film; (ii) forming an adhesive layer by coating and drying a thermosetting adhesive composition on the thermoplastic polymer film; And (iii) arranging the adhesive layer and the release layer of the thermoplastic polymer film to face each other and then integrating through continuous roll lamination.

The thermosetting adhesive composition may be prepared by performing a method known in the art, and may include, for example, at least one of a thermosetting resin, a thermoplastic resin, a curing agent, and an inorganic filler.

According to an embodiment of the present invention, the thermosetting adhesive composition constituting the adhesive layer 20 includes 30 to 70 parts by weight of an epoxy resin based on 100 parts by weight of the composition; 1 to 35 parts by weight of a thermoplastic resin; 0.1 to 10 parts by weight of a curing agent (additive); And 0 to 30 parts by weight of an inorganic filler. If necessary, at least one of a silane coupling agent, a dispersant, a flame retardant filler, and a curing accelerator may be further included.

Then, a thermosetting adhesive composition is applied on the prepared thermoplastic polymer film and then dried.

A method of applying the thermosetting adhesive composition onto the thermoplastic polymer film is not particularly limited, and a conventional coating method known in the art may be used without limitation. For example, various methods such as casting method, dip coating, die coating, roll coating, slot die, comma coating, or a mixture thereof may be used. The drying process may be appropriately performed within conventional conditions known in the art. For example, drying may be performed at 40 to 200°C.

Subsequently, after the adhesive layer 20 and the release layer 30 formed on the thermoplastic polymer film 10 are disposed to face each other, a thermocompression bonding lamination process is performed.

The compression process conditions can be appropriately adjusted within a conventional range known in the art. For example, thermocompression Lami. Conditions during the process (roll-to-roll) may be performed under conditions of room temperature (RT) to 150°C, ^{pressure of 3 to 200 kgf/cm 2} , and compression speed of 0.1m/min to 20m/min. However, it is not particularly limited thereto. At this time, the temperature during the thermal compression bonding may be appropriately adjusted in consideration of the glass transition temperature (Tg) of the thermoplastic polymer film 10.

Here, the thermoplastic polymer film 10 and the release layer 30 may each have a sheet shape, and may be continuously laminated according to the above-described roll-to-roll method and then wound in a roll shape. In addition, sheet-to-sheet lamination, roll-to-sheet lamination, or the like may be used.

By integrating the thermoplastic polymer film 10, the adhesive layer 20, and the release layer 30 through the continuous roll lamination process as described above, not only the process simplification and cost reduction are achieved, but also the slimming effect and heat resistance durability The effect of can be applied at the same time.

<Flexible metal composite substrate>

In addition, the present invention provides a flexible metal composite substrate provided with the above-described coverlay film.

Here, the flexible metal composite substrate may refer to a metal printed circuit board in which at least one coverlay film and a metal layer are stacked, and may have a structure in which at least one coverlay is stacked on one or more circuit patterns. .

3 schematically shows a cross-sectional structure of a flexible metal composite substrate 300 according to another embodiment of the present invention.

In FIG. 3, the same reference numerals as in FIGS. 1 to 2 denote the same members. Hereinafter, in the description of FIG. 3, contents overlapping with those of FIGS. 1 to 2 are not described again, and only differences are described.

Referring to FIG. 3, the flexible metal composite substrate 300 of the present invention comprises: a first thermoplastic polymer film 10 having a _{melting point (T m) of 300° C. or less;} And a first coverlay film 100 including a first adhesive layer 20; A second thermoplastic polymer film 10 having a melting point (T _{m) of 300° C. or less;} And a second coverlay film 100 including a second adhesive layer 20; And a metal layer 40 disposed between the first coverlay film 100 and the second coverlay film 100, and may have a structure in which these (100, 40, 100) are integrally laminated.

Specifically, in the flexible metal composite substrate 300, one side of the metal layer 40 is in close contact with the first adhesive layer 20, the other side is in close contact with the second adhesive layer 20, and the first adhesive layer 20 ) And the upper and lower surfaces of the second adhesive layer 20, that is, on the outermost surface of the composite substrate, the first and second thermoplastic polymer films 10 are respectively disposed. At this time, each member 100, 10, 20 indicated by the same reference numeral may have the same or different configurations.

In the flexible metal composite substrate 300 of the present invention, the metal layer 40 is a conductor layer forming a circuit pattern.

The type of conductor constituting the metal layer 40 is not particularly limited, and an electrically conductive conductor material known in the art may be used. For example, it may be one or more metals selected from the group consisting of copper (Cu), copper alloy, aluminum (Al), and aluminum alloy, and the metal component included in the alloy is not particularly limited. , It is possible to use a conventional metal known in the art. The metal layer 40 is preferably a foil-shaped conductive metal, and more preferably a flat copper foil.

The thickness of the metal layer 40 is not particularly limited, and may be 9 to 105 μm, preferably 18 to 70 μm in consideration of the thickness, electrical and mechanical properties of the final product. In addition, the metal layer 40 may be a copper foil or an aluminum foil, and may be a copper foil or an aluminum foil having an average roughness (Ra) of 0.1 μm or less on both sides. More specifically, it may be a rolled copper foil having an average roughness (Ra) of both sides in a direction perpendicular to the rolling direction of 0.1 μm or less. When using relatively thick copper foil of 35 μm or 70 μm, there may be a crack issue, so the use ratio of rolled copper foil to electrolytic copper foil may be high.

In addition, each of the metal layers 40 may form circuit pattern portions through conventional dry or wet etching known in the art. In this case, the circuit pattern portion may be formed to have the same or different predetermined area, line width, and shape according to the intended application. Although not shown in FIG. 3 below, the metal layer 40 includes at least one circuit pattern having a predetermined area, line width, and shape, and in particular, a copper circuit pattern layer and a photo solder resist insulating the circuit layer ( It is preferable that the PSR) layer is formed.

In addition, although not shown in FIG. 3 below, the flexible metal composite substrate 300 includes at least one through hole (not shown) penetrating the first coverlay film 100 and the second coverlay film 100, and , It may have a structure electrically conductive through the through hole.

The flexible metal composite substrate 300 of the present invention described above may have various total thicknesses depending on the applied product. For example, the total thickness may be 30 μm to 300 μm, and specifically 50 to 200 μm, but is not particularly limited thereto.

The flexible metal composite substrate 300 is a plurality of coverlay films exhibiting excellent adhesion, high heat resistance, and mechanical properties through the adoption of a thermoplastic polymer film with a controlled _{melting point (T m) and optimization of a binder used as an adhesive layer component.} By providing (100), it is possible to secure safety and excellent general properties at the same time when applied to a battery of an electric vehicle.

According to an embodiment of the present invention, a peel strength value of the first adhesive layer (or the second adhesive layer, 20) with respect to the metal layer 40 in the flexible metal composite substrate 300 is 1.0 kgf/cm or more, preferably May be 1.2 to 2.0 kgf/cm. In addition, the peel strength value of the first adhesive layer (or the second adhesive layer, 20) with respect to the first thermoplastic polymer film (or the second thermoplastic polymer film, 10) is 1.0 kgf/cm or more, preferably 1.1 to 1.7 kgf. can be /cm.

According to another embodiment of the present invention, in the flexible metal composite substrate 300, a blister is generated on the surface of the first thermoplastic polymer film (or the second thermoplastic polymer film 10) in a solder bath at 250°C. The measurement time until it is made may be 10 seconds or more.

The flexible metal composite substrate 300 according to the present invention may be manufactured according to a conventional method known in the art, and for example, may be laminated through a continuous roll lamination process.

For example, a first coverlay film 100 and a second coverlay film 10 are disposed on the upper and lower surfaces of the metal layer 40 as the center, but the first adhesive layer 20-the metal layer 40 )-The second adhesive layers 20 are disposed opposite to each other so that they are in contact with each other, and then bonded to form a laminate. In this case, if necessary, after bonding the first coverlay film 100 to one surface of the metal layer 40, the second coverlay film 100 may be sequentially bonded to the other surface of the metal layer 40. In addition, when the coverlay film 100 includes the release layer 30, the release layer 30 is detached and then bonded to the metal layer 40.

After configuring the laminate as described above, heat and/or pressure are applied to perform thermal compression bonding. At this time, the thermocompression bonding conditions are not particularly limited, and as an example, after constructing the above-described laminate, it is put into a press, and a temperature of about 120 to 160 °C, ^{a pressure of 7 to 60 kgf/cm 2} , and a condition of 50 to 120 minutes It can be thermally pressed under. At this time, when a thermoplastic polymer film having a low glass transition temperature (Tg) is provided, it is preferable to press heat compression at a relatively low temperature, such as 150°C or less, specifically 135 to 150°C.

Meanwhile, in the present invention, it is specifically exemplified that one metal layer 40 and two coverlay films 100 are sequentially stacked and then subjected to a thermocompression bonding process to produce the flexible metal composite substrate 300. However, the present invention is not limited thereto, and manufacturing by diversifying the number of the metal layer 40 and the coverlay film 100 or the number and shape of the circuit pattern included in the metal layer 40 is also within the scope of the present invention.

The flexible metal composite substrate 300 of the present invention configured as described above may be mounted inside a vehicle, specifically a battery disposed on the bottom of an electric vehicle. In addition, it can be applied to various electronic and communication devices to improve safety and general characteristics.

Hereinafter, the present invention will be described in detail through Examples, but the following Examples and Experimental Examples are only illustrative of one embodiment of the present invention, and the scope of the present invention is not limited to the following Examples and Experimental Examples.

[Reference example]

The properties of the thermoplastic polymer adopted in the present invention were measured as follows. Polyimide (PI) was used as a control.

Evaluation item (Unit) Polymer Test Method PCT PET PEN PI thickness ㎛ 25 25 25 25 density g/cm ³ 1.25 1.40 1.36 1.42~1.45 ASTM D 1505 Elongation at break
(elongation at break) % MD 141 166 90 About 72 ASTM D 882 TD 78 139 93 Heat shrinkage % MD 1.1 1.5 0.6 - 150℃, 30min TD 1.1 0.2 0.4 Melting point (T _m ) ℃ 265 255 266 - ASTM E 794 Glass transition temperature
(Tg) ℃ 91 78 123 360~410 Moisture absorption % 0.27 0.38 0.33 2.5 IPC-TM-650 2.6.2

[Examples 1 to 9]

1-1. Preparation of thermosetting adhesive composition

Components of the thermosetting adhesive composition were prepared by mixing according to the ratios of the following [Table 2] and [Table 3]. In Table 3 below, the usage unit of each composition is parts by weight.

1-2. Preparation of coverlay film (1)

On one side of the PEN film (thickness: 50 μm), the thermosetting adhesive composition of Example 1-1 was coated to form an adhesive layer so that the thickness after drying became 38 μm, and a release paper was disposed on the adhesive layer to have a thickness of 88 A coverlay film of µm (excluding the thickness of the release paper) was prepared.

1-3. Manufacturing of ductile metal composite substrate

Each of the coverlay films of Example 1-2 was disposed on both sides of the rolled copper foil (thickness: 35 μm), but after disposing an adhesive layer from which the release paper was removed on both sides of the copper foil, 150° C., A flexible metal composite substrate was prepared by pressing for 2 hours at a linear pressure of 35 kgf/cm ^2.

The properties of the thus prepared coverlay film and the flexible metal composite substrate were measured according to the following measurement method, and the results are shown in Table 3 below.

Composition Detailed configuration Thermosetting
Suzy A-1 Thermosetting resin ¹ : Brominated epoxy resin, Kukdo Chemical YDB-400
(EEW: 380-420 g/eq, softening point: 64-74℃, Br content: 46-50 wt%) A-2 Thermosetting resin ² : Bisphenol A epoxy resin, Kukdo Chemical YD-011 (EEW: 450-500 g/eq, softening point: 60-70℃) A-3 Thermosetting resin ³ : polyfunctional phenol novolac epoxy resin, Kukdo Chemical YDPN-638 (EEW: 170-190 g/eq, n = 1.6) Thermoplastic
Suzy B Acrylonitrile-butadiene rubber (NBR) filler C Phosphorus flame retardant filler (white powder), OP 930 Dispersant D W-903, BYK Silane
Coupling agent E N-2-(Aminoethyl)-3-aminopropyltrimethoxysilane, Shin-Etsu, KBM-603 Hardening accelerator F Imidazole-based hardener, 2E4Mz

Furtherance Example Comparative example One 2 3 4 5 6 7 8 9 One 2 combination A-1 30 40 40 40 40 40 40 40 50 40 40 A-2 20 20 20 20 25 15 - 10 10 - 30 A-3 - - - - - - 20 10 - - - B 20 20 20 20 15 25 20 20 20 20 - C 20 10 10 10 10 10 10 10 - 30 10 D One 0.5 0.5 0.5 0.5 0.5 0.5 0.5 - One 0.5 E 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 F 0.12 0.12 0.08 0.15 0.12 0.12 0.12 0.12 0.12 0.12 0.15 characteristic Flame retardant
(V-0) △ O O O O △ O O △ O O Peel strength (@Cu) 1.4 1.6 1.6 1.6 1.6 1.7 1.6 1.6 1.6 0.9 1.2 Peeling strength
(@Film) 1.2 1.4 1.4 1.4 1.3 1.5 1.2 1.3 1.5 0.7 0.4 Heat resistance Pass Pass Pass Pass Pass Pass Pass Pass Pass X Pass Resin Crack O O O O △ O O O O △ X

[Comparative Examples 1 to 2]

Except for changing the composition as shown in Table 3, it was carried out in the same manner as in Example 1 to prepare a coverlay film and a flexible metal composite substrate of Comparative Examples 1 to 2, respectively.

[Experimental Example 1]

Using the flexible metal composite substrate prepared in Examples 1 to 9 and Comparative Examples 1 to 2 was measured according to the following measurement method, and the results are shown in Table 3 above.

1) Flame retardancy evaluation

The composite substrate was impregnated with a copper etchant to remove the copper foil layer, prepared as a sample with a length of 127 mm and a width of 12.7 mm, and evaluated according to UL94 test method (V method).

2) Peel strength (P/S) evaluation

According to JIS C6471 (or IPC-TM-650 2.4.8 evaluation standard), under the condition of 25°C, 50 mm/mm of the adhesive layer in the direction of 90° to the side of the PEN film and the surface of the copper foil layer of the composite substrate, respectively. The minimum value of the force required to peel at a rate of minutes was measured, and expressed as peel strength.

3) Evaluation of heat resistance (solder floating)

A test piece was prepared in accordance with JIS C6471 (or IPC-TM-650 2.4.13 evaluation standard), and the test piece was suspended in a 250°C solder bath. Thereafter, the time until blisters occurred on the surface of the PEN film was measured.

4) Evaluation of Resin Crack

The composite substrate was repeatedly folded 180 degrees for 5 times, and then it was confirmed whether or not cracks occurred. When a crack occurred and cut, it was evaluated as X, if a crack occurred but no cutting occurred, it was evaluated as △, and if no crack occurred, it was evaluated as ○.

As a result of the experiment, in the case of Examples 1 to 9 including a thermoplastic polymer film and an adhesive layer that satisfies a specific blending ratio while a thermosetting resin and a thermoplastic resin were mixed, in terms of flame retardancy, heat resistance, adhesion, and crack properties I could see that they were all excellent.

100, 200: coverlay film
10: thermoplastic polymer film
20: adhesive layer
30: release layer
300: flexible metal composite substrate
40: metal layer

Claims (23)

A thermoplastic polymer film having a melting point (T _m ) of 300° C. or less; And
Adhesive layer formed on the thermoplastic polymer film
Coverlay film comprising a. The method of claim 1,
The thermoplastic polymer film is a coverlay film having a glass transition temperature (Tg) of 250 °C or less. The method of claim 1,
The thermoplastic polymer film satisfies at least one of the following physical properties (i) to (iv), a coverlay film:
(i) a density of at ^{least 1.15 g/cm 3} and less than 1.42 g/cm ³ measured according to ASTM D 1505;
(ii) 75% or more elongation at break measured according to ASTM D 882;
(iii) 2% or less of heat shrinkage (150° C., 30 minutes) in the longitudinal direction and the width direction of the film; And
(iv) less than 1.0% moisture absorption The method of claim 1,
The thermoplastic polymer film is polyethylene naphthalate (PEN), polyethylene terephtalate (PET), polycyclohexadimethylene terephtalate (PCT), polytrimethylene terephthalate (polytrimethyleneterephtalate, PTT), poly Butylene terephthalate (PBT), polytrimethylene naphthalate (PTN), polybutylene naphthalate (PBN), polycyclohexadimethylene naphthalate (PCN), and polycyclo A coverlay film comprising at least one polyester-based polymer selected from the group consisting of hexanedimethylene cyclohexadimethylcarboxylate (PCC). The method of claim 1,
The thermoplastic polymer film contains at least one aromatic sulfone polymer selected from the group consisting of polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), and polyethersulfone (PES), or polyetheretherketone (PEEK). ) Coverlay film containing. The method of claim 1,
The adhesive layer
Thermosetting resin; And
A coverlay film formed from an adhesive composition comprising at least one selected from the group consisting of a thermoplastic resin, a curing agent, and an inorganic filler. The method of claim 6,
The thermosetting resin is a coverlay film comprising 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. The method of claim 6,
The thermoplastic resin is acrylonitrile-butadiene rubber (NBR), styrene butadiene rubber (SBR), acrylonitrile-butadiene-styrene rubber (ABS), carboxyl-terminated butadiene acrylonitrile rubber (CTBN), polybutadiene. (polybutadiene), and a coverlay film comprising at least one selected from the group consisting of styrene-butadiene-ethylene resin (SEBS). The method of claim 6,
The mixing ratio of the thermosetting resin and the thermoplastic resin is 20 to 80: 80 to 20 weight ratio based on 100 parts by weight of the polymer resin coverlay film. The method of claim 6,
The adhesive layer is a coverlay film further comprising at least one of a silane coupling agent, a dispersant, a flame retardant filler, and a curing accelerator. The method of claim 1,
Coverlay film further comprising a release layer disposed on the adhesive layer. The method of claim 11,
The release layer is a coverlay film comprising any one of a release paper, and a release polymer film. The method of claim 1,
The thickness of the thermoplastic polymer film is 12 to 125 ㎛,
The thickness of the adhesive layer is 5 to 100 ㎛, coverlay film. A first thermoplastic polymer film having a melting point (T _m ) of 300° C. or less; And a first coverlay film including a first adhesive layer.
A second thermoplastic polymer film having a melting point (T _m ) of 300° C. or less; And a second coverlay film including a second adhesive layer. And
A metal layer disposed between the first coverlay film and the second coverlay film;
Including, the flexible metal composite substrate that they are integrally laminated. The method of claim 14,
One side of the metal layer is in close contact with the first adhesive layer, the other side of the flexible metal composite substrate in close contact with the second adhesive layer. The method of claim 14,
The peel strength value of the first adhesive layer with respect to the metal layer is 1.0 kgf/cm or more,
A flexible metal composite substrate having a peel strength value of 1.0 kgf/cm or more of the first adhesive layer with respect to the first thermoplastic polymer film. The method of claim 14,
The metal layer is a flexible metal composite substrate selected from the group consisting of copper (Cu), copper alloy, aluminum (Al), and aluminum alloy. The method of claim 14,
The metal layer is _a flexible metal composite substrate of copper foil or aluminum foil having an average roughness (R a) on both sides of 0.1 μm or less. The method of claim 14,
The thickness of the metal layer is 9 to 105 ㎛, flexible metal composite substrate. The method of claim 14,
The metal layer is a flexible metal composite substrate including at least one layer of circuit patterns patterned in a predetermined shape. The method of claim 14,
Flexible metal composite substrate applied to batteries of electric vehicles. (i) preparing a thermoplastic polymer film;
(ii) forming an adhesive layer by coating and drying a thermosetting adhesive composition on the thermoplastic polymer film; And
(iii) arranging the adhesive layer and the release layer of the thermoplastic polymer film to face each other and then integrating through continuous roll lamination.
The method for producing a coverlay film according to claim 1 comprising a. The method of claim 22,
The roll lamination process of step (iii) is a method of manufacturing a coverlay film performed at a temperature of not less than the glass transition temperature (Tg) of the thermoplastic polymer and not more than the melting point (T _{m ).}

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