KR102390869B1 - Coverlay film and manufacturing method thereof, flexible metal composite substrate comprising the same - Google Patents

Abstract

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

Description

Coverlay film, manufacturing method thereof, and flexible metal composite substrate comprising the coverlay film

The present invention provides a thermoplastic polymer film having a melting point (T _m ) of 300° C. or less, thereby reducing the cost compared to the conventional polyimide (PI)-based film and improving safety and durability, so that a coverlay film that can be applied to a battery module of an electric vehicle and a method for manufacturing the same, and to a flexible metal composite substrate including the coverlay film.

Electric vehicles (EVs) were developed as part of a measure against exhaust gas, and have the advantage of low noise and no exhaust gas at all. Since such an electric vehicle drives an electric motor with electric energy and rotates the wheels through the power transmission device to drive the electric vehicle, a high-output and large-capacity battery must be used to supply the necessary power for the driving force.

As the battery provided in the medium or large device such as a vehicle, a medium or large battery module in which a plurality of battery cells are electrically connected is used. As described above, in order to configure a medium-to-large battery module, for example, one battery pack using a plurality of batteries, a plurality of mechanical couplings and electrical connections are required, and a printed circuit board (PCB) for each module constituting the battery pack. This should be built in.

On the other hand, a printed circuit board (PCB) is generally configured in a form in which a polyimide (PI)-based insulating film is laminated on one or both sides of a copper foil layer, and if necessary, the purpose of protecting the circuit pattern of the copper foil layer As such, a coverlay film in which an adhesive and an insulating film are laminated may be used. A polyimide resin is often used as the insulating film. Although the polyimide (PI) film is a heat-resistant polymer having a glass transition temperature (Tg) of 300° C. or higher, it is burned and carbonized when the temperature is abnormally increased. Such carbides may remain in the vehicle's battery fluid and cause safety problems such as fire and explosion.

The present invention has been 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 cost reduction, 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 an adhesive layer formed on the thermoplastic polymer film.

According to an 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 may include: (i) a density of 1.15 g/cm ³ or more and less than 1.42 g/cm ³ measured according to ASTM D 1505; (ii) at least 75% elongation at break as measured in accordance with ASTM D 882; (iii) 2% or less of heat shrinkage in the longitudinal and transverse directions of the film (150° C., 30 minutes); and (iv) less than 1.0% moisture absorption.

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

According to one 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). 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 (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 first thermoplastic polymer film having a melting point (T _m ) of 300° C. or less; and a first coverlay film comprising 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 comprising a second adhesive layer; and a metal layer disposed between the first coverlay film and the second coverlay film, and providing a flexible metal composite substrate in which they are integrally laminated.

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

According to one 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 a double-sided average roughness (Ra) of 0.1 μm or less.

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

According to one 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. For an embodiment of the manufacturing method, (i) preparing a thermoplastic polymer film; (ii) coating and drying a thermosetting adhesive composition on the thermoplastic polymer film to form an adhesive layer; and (iii) disposing 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 an 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) of the thermoplastic polymer and lower than or equal to the melting point (T _m ) of the thermoplastic polymer.

According to an embodiment of the present invention, by adopting 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-saving 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, adhesion, 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 may be usefully applied to a battery of an electric vehicle.

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 view schematically showing a cross-section of a coverlay film according to an embodiment of the present invention.
2 is a view schematically showing a cross-section of a coverlay film according to another embodiment of the present invention.
3 is a view schematically showing a cross-section of a flexible metal composite substrate according to an embodiment of the present invention.
4 is a view 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. Examples of the present invention are provided to more completely explain 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 not limited to the following examples Examples are not limited thereto. In this case, the same reference numerals refer to the same structures throughout this specification.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning 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 to be interpreted ideally or excessively unless clearly defined in particular.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness 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, "on" or "on" means that it includes not only the case located above or below the target part, but also the case where there is another part in the middle, and the direction of gravity must be It does not mean that it is positioned above the reference. And, in the present specification, terms such as “first” and “second” do not indicate any order or importance, but are used to distinguish components from each other.

In addition, throughout the specification, when referred to as "planar", it means when the target part is viewed from above, and "in cross-section" means when viewed from the side when the cross-section of the target part is vertically cut.

<Coverlay Film>

According to one embodiment of the present invention, there is provided a coverlay film comprising a thermoplastic polymer film having a predetermined melting point (T _m ).

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 thereto. This coverlay film is in close contact with the metal layer of the flexible metal composite substrate to be described later, and specifically used for protecting and insulating the exposed circuit pattern of the 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 ; and an adhesive layer 20 formed on the film. Hereinafter, each configuration of the coverlay film 100 will be described in detail as follows.

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 , and serves as a support for coating the adhesive layer 20 and is an insulating layer. . In particular, when it is disposed adjacent to the metal layer (40 in FIG. 3) to form a flexible metal composite substrate (300 in FIG. 3), the metal layer 40 is protected to be insulated from the outside while being in close contact with the metal layer 40 to provide excellent It exhibits flexibility, heat resistance and adhesion.

The thermoplastic polymer film 10 may use a conventional polymer having a melting point (T _m ) or a melting point (T _m ) of 300° C. or less without limitation, and specifically, while having a melting point (T m), a glass transition temperature A thermoplastic polymer with as high a (Tg) as possible is 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, specifically, the melting point (Tm) It is 150 to 280 ℃, and a glass transition temperature (Tg) of 70 to 200 ℃ can be used.

That is, the polyimide (PI) resin used as the conventional insulating film is a heat-resistant material, but it is a kind of thermosetting polymer, so when the temperature of the battery rises abnormally, it burns to produce carbide, and the carbide causes a fire in automobiles. It may cause safety problems such as explosion or explosion. In contrast, in the present invention, by using a thermoplastic polymer having a melting point (T _m ) or a melting point (T _m ) of 300° C. or less, it melts itself in the above-described abnormal temperature range to generate a short circuit, thereby preventing fire or explosion. fundamentally preventable.

For another example, the moisture absorption of the thermoplastic polymer film 10 may be less than 1.0%, preferably less than 0.4%. Here, the moisture absorption may be measured according to IPC-TM-650 2.6.2. Conventional polyimide (PI) films have a relatively high moisture absorption rate, which may cause problems such as malfunction when applied to automobiles exposed to external environments. 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 an automobile exposed to the 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. These polyester resins are polymerized by mixing and heating dicarboxylic acid and diol, and blowing the resulting water under reduced pressure, and has colorless and transparent properties among polymer resins, as well as excellent mechanical properties, heat resistance, and chemical resistance.

Non-limiting examples of the polyester-based thermoplastic polymer that can be used include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycyclohexadimethylene terephtalate (PCT), polytrimethylene Terephthalate (polytrimethyleneterephtalate, PTT), polybutyleneterephtalate (PBT), polytrimethylene naphthalate (PTN), polybutylene naphthalate (PBN), polycyclohexanedimethylene naphthalate ( Polycyclohexadimethylene naphthalate (PCN), and polycyclohexanedimethylene cyclohexadimethylcarboxylate (polycyclohexadimethylene cyclohexadimethylcarboxylate, PCC) may include at least one selected from the group consisting of.

Also, non-limiting examples of aromatic sulfone polymers that can 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 type. And polyether ether ketone (PEEK) may be used. As a preferred example of the thermoplastic polymer film 10, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycyclohexanedimethylene terephthalate (PCT), polyphenylsulfone (PPSU), or a mixture thereof, etc. there is.

The thermoplastic polymer film 10 may be in the form of a self-supporting film or sheet, or a coating layer formed on the film or sheet. In addition, it may have a single-layer structure composed of one insulating film, or a multi-layer structure in which two or more types of insulating films different from each other are laminated. For example, the thermoplastic polymer film 10 may be a thermoplastic polymer film having the aforementioned 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 as or different from each other.

The thermoplastic polymer film 10 secures excellent mechanical properties and durability in the normal temperature range, and at the same time reduces the difference in coefficient of thermal expansion (CTE) with the metal layer 40, which will be described later, so that when applied to a final product, bending characteristics and low expansion are achieved. , 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, mica, and the like. The amount of the inorganic filler used is not particularly limited, and may be appropriately adjusted in consideration of the aforementioned heat resistance and mechanical properties. The average particle diameter of these inorganic fillers 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 in the art or a colored polymer film. In this case, the colored polymer film has a colored form or a white or black form. Here, the material that can be used as the colorant is not particularly limited, and 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 known in the art are used. can be heard Depending on the type of the colorant, the thermoplastic film may have a color such as white, black, dark gray, black 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 physical properties (i) to (iv) may be satisfied, specifically two or more, more specifically, all may be satisfied. For example, (i) the density measured according to ASTM D 1505 may be 1.15 g/cm ³ or more and less than 1.42 g/cm ³ , and specifically 1.20 to 1.40 g/cm ³ . (ii) The elongation at break measured according to ASTM D 882 may be 75% or more, and specifically may be 77 to 200%. (iii) the longitudinal direction (MD, machine direction) and the width direction (TD, transverse direction) of the film may each have a heat shrinkage (heat shrinkage, 150 ° C. × 30 minutes) of 2% or less, specifically 1.5% can (iv) moisture absorption may be less than 1.0%, specifically, it may be 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 may be appropriately adjusted in consideration of insulation, handling properties of the film, physical rigidity, 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, and more preferably 25 to 50 μm. If necessary, the surface of the thermoplastic polymer film 10 may be 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 facing the metal layer 40 , excellent adhesion to the metal layer 40 may be exhibited.

The adhesive layer 20 may use a conventional thermosetting adhesive component known in the art without limitation, 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 usable thermosetting resins include epoxy resins, polyurethane resins, phenolic resins, melamine resins, silicone resins, urea resins, vegetable oil-modified phenolic resins, xylene resins, guanamine resins, diallyl phthalate resins, vinyl esters. It may be at least one selected from the group consisting of a resin, an unsaturated polyester resin, a furan resin, a polyimide resin, a cyanate resin, a maleimide resin, and a benzocyclobutene resin. Preferably, they are an epoxy resin, a phenol resin, a melamine resin, a silicone resin, a urethane resin, or a urea resin.

Among them, the epoxy resin is preferable because it has 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 halogen content included in the halogen-based epoxy resin is not particularly limited, and may be, for example, 10 to 80% in a molecule, specifically 30 to 60%.

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

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

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) serves as a standard (scale) indicating the width (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 higher the polydispersity index (PDI), the wider the molecular weight distribution, and the closer to 1, the more it is 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 an ND (narrow dispersity) epoxy resin. That is, the ND epoxy resin of 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 the molecular weight distribution is uniform. As such, the ND epoxy resin having a uniform molecular weight distribution has less side reaction and has a higher degree of curing than a general epoxy resin. A minimized resin layer is obtained, which results in a resin layer having high adhesion and low water absorption. In addition, since the ND epoxy resin has a low content of impurities such as ions and side reaction products generated during the synthesis of the epoxy resin, it exhibits high purity. An adhesive layer 20 is obtained. In addition, as the ND (narrow dispersity) epoxy resin is used, the viscosity of the epoxy resin composition is lowered, which in turn can have the effect of improving the wetting properties and adhesion of the adhesive layer 20 formed of the epoxy resin composition.

On the other hand, multilayer flexible circuit boards are generally manufactured by laminating and bonding a plurality of metal laminates or printed circuit boards to each other. Anti-migration resistance is also required. This is because, when the conductive ions present in the circuit layer freely move, a short circuit is induced, thereby reducing the reliability of the metal laminate or the multilayer flexible printed circuit board including the same.

In contrast, since the adhesive composition according to the present invention contains a ND epoxy resin and has a low ion content such as K ⁺ , NH ⁴⁺ , Na ⁺ , Cl ⁻ and shows high purity, the adhesive layer 20 made therefrom is very It can exhibit low absorption and ion content. As such, 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 conductive ions (eg, Cu ²⁺ ) migrate to the adjacent metal layer 40 . It is possible to provide a multilayer flexible metal composite substrate that is minimized and has 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, a low equivalent weight (EEW) epoxy resin has a low melt viscosity and good wettability in adhesion, and a high equivalent weight epoxy resin (EEW) has plasticity by itself, so the bendability (bending workability) of the laminate and molding properties such as punchability and the like. Accordingly, when the adhesive layer 20 is formed by including at least two epoxy resins having a polymerization degree (n) or an equivalent difference, high adhesiveness, excellent moisture resistance reliability, excellent moldability, and the like can be exhibited. As an example, the adhesive layer 20 may include a first epoxy resin having an epoxy equivalent weight (EEW) of 250 to 430 g/eq; a second epoxy resin having an epoxy equivalent weight (EEW) of 440 to 800 g/eq; And the epoxy equivalent weight (EEW) may be configured by mixing a third epoxy resin in the range of 100 ~ 240 g / eq.

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

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

As the thermoplastic resin, a conventional thermoplastic resin known in the art, a thermoplastic rubber, or both 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 having 1 to 8 carbon atoms an ester resin (acrylic rubber), or a mixture of one or more thereof. Preferably, it may be an acrylic rubber.

The above-mentioned thermoplastic resin, specifically rubber, preferably contains a functional group capable of reacting with an epoxy resin, which is a thermosetting resin. A specific example 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 these functional groups form a strong bond with the epoxy resin, heat resistance after curing is improved, which is preferable. In particular, in the present invention, it is more preferable to use an acrylonitrile-butadiene copolymer (NBR) in consideration of adhesiveness, flexibility and thermal stress relief effect, and this copolymer is an epoxy resin and It is more preferable to include a carboxyl group as a functional group capable of reacting.

The content of the thermoplastic resin is not particularly limited, and may be, for example, 1 to 35 parts by weight, 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 adhesion 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. 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, preferably 50 -80: It may be a 20-50 weight ratio.

In the present invention, conventional curing agents 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 curing agents that can be used include imidazole-based, phenol-based, anhydride-based, dicyanamide-based, and aromatic polyamine curing agents. Non-limiting examples of usable curing agents 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 in this case, 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. The 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 in consideration of 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 filler 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 be in the range of 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, specifically 5 to 30 parts by weight, based on the total weight (100 parts by weight) of the adhesive composition.

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.

The silane coupling agent may be used without limitation, any conventional one known in the art, 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, etc. can be used. The above-mentioned components may be used alone or in combination of two or more. The content of the silane coupling agent is not particularly limited, and may be, for example, greater than 0, 5 parts by weight or less, and preferably 0.3 to 1.5 parts by weight, based on 100 parts by weight of the total weight of the adhesive layer 20 .

The dispersant serves to disperse each material constituting the composition for forming an adhesive layer and prevent re-agglomeration by maintaining a distance to express uniform physical properties of the adhesive layer. As the dispersant, a conventional dispersant known in the art may be used, for example, a high molecular weight block copolymer type dispersant. Preferably, a wettable dispersant is used. Such a wettability dispersing agent can further improve the dispersibility of the inorganic filler or filler to be mixed.

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

In addition, in the present invention, in order to impart flame retardancy to the adhesive layer 20, one or more flame retardant fillers 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 has a flame retardancy that passes the UL standard vertical combustion test (VW-1 test). desirable.

More specifically, as the flame retardant filler, one or more selected from the group consisting of a halogen flame retardant, a phosphorus-based flame retardant, a nitrogen-based flame retardant, a metal-based flame retardant and an antimony-based flame retardant may be used, and preferably one or more and seven or less are mixed. It can be used, and more preferably, 3 or more types and 5 or less types of compounds can be mixed and used. Non-limiting examples of the flame retardant that can be used include chlorine-based flame retardants such as chlorinated paraffin, chlorinated polyethylene, chlorinated polyphenyl, perchloropentacyclodecane; Ethylenebispentabromobenzene, ethylenebispentabromodiphenyl, tetrabromoethane, tetrabromobisphenol A, hexabromobenzene, decabromobiphenyl ether, tetrabromophthalic anhydride, polydibromophenylene oxide, Bromine-type flame retardants, such as hexabromocyclodecane and ammonium bromide; Trialyl phosphate, alkyl allyl phosphate, alkyl phosphate, dimethyl phosphonate, phosphonate, halogenated phosphonate ester, trimethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, octyl diphenyl phosphate, tricre Dylphosphate, credylphenylphosphate, triphenylphosphate, tris(chloroethyl)phosphate, tris(2-chloropropyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(2,3-dibromopropyl) Phosphate, tris (bromochloropropyl) phosphate, s (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 (diethyl phosphinic acid) aluminum; polyols such as phosphonate polyols, phosphate polyols, and halogen element-containing polyols; Aluminum hydroxide, magnesium hydroxide, magnesium carbonate, antimony trioxide, antimony trichloride, zinc borate, antimony borate, boric acid, antimony molybutene acid, molybutene oxide, phosphorus/nitrogen compound, calcium/aluminum silicate, titanium dioxide, zirconium compound, tin compound , metal powders or inorganic compounds such as dousonite, calcium aluminate hydrate, copper oxide, metal copper powder, calcium carbonate, and 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 preferable, and phosphorus-based flame retardants are more preferable.

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

For one embodiment of the present invention, the thermosetting adhesive composition constituting the adhesive layer 20 may include 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 may implement chemical resistance and flexibility, and the thermoplastic resin exhibits an effect of improving adhesion and flexibility and relieving thermal stress. In this case, the thermosetting adhesive composition may include an organic solvent, and the amount of the organic solvent used may be in the range of the remaining amount to match 100 parts by weight of the entire composition.

In addition to the above-mentioned components, the present invention, as long as it does not impair the inherent properties of the adhesive layer 20, if necessary, such as flame retardants generally known in the art, other thermosetting resins or thermoplastic resins not described above, and oligomers thereof. Various polymers, solid rubber particles or UV absorbers, silane coupling agents, antioxidants, polymerization initiators, dyes, pigments, thickeners, leveling agents, antioxidants, hiding agents, lubricants, processing stabilizers, plasticizers, foaming agents, reinforcing agents, colorants, fillers, Other additives such as granules and metal deactivators may be further included.

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

2 is a cross-sectional view schematically showing a cross section of the 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 , content overlapping with FIG. 1 will not be described again, and only differences will be described.

When described with reference to FIG. 2 , the coverlay film 200 of the present invention is compared with FIG. 1 in which the thermoplastic polymer film 10 is laminated on one surface of the adhesive layer 20 , the other surface of the adhesive layer 20 . The release layer 30 is further included. Specifically, the coverlay film 200 according to an embodiment of FIG. 2 includes an adhesive layer 20; a thermoplastic polymer film 10 disposed on one surface 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 come into contact with the thermoplastic polymer film 10 .

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

The release polymer film can be applied without limitation in the configuration of 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, triacetylcellulose films, and the like. , 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 There are turketone film, polyethersulfone film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic resin film, norbornene-based resin film, cycloolefin resin film, and the like. These plastic films may be either transparent or translucent, may be colored, or may be uncolored, and may be appropriately selected according to the use.

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 the binder used as the 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 for 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 as needed.

Specifically, for an embodiment of manufacturing the coverlay film, (i) preparing a thermoplastic polymer film; (ii) coating and drying a thermosetting adhesive composition on the thermoplastic polymer film to form an adhesive layer; and (iii) disposing 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, the thermosetting adhesive composition is applied on the prepared thermoplastic polymer film and then dried.

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

Next, 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 lamination process is performed.

The compression process conditions may be appropriately adjusted within a conventional range known in the art. For example, thermocompression bonding Lami. During the process (roll-to-roll) conditions, a temperature of room temperature (RT) to 150 ℃, a pressure of 3 to 200 kgf/cm ² , and a compression speed of 0.1 m/min to 20 m/min may be performed under conditions. However, it is not particularly limited thereto. In this case, the temperature during the thermocompression 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 aforementioned roll-to-roll method and then wound up in a roll shape. In addition, sheet-to-sheet (sheet to sheet) paper, roll-to-sheet (roll to sheet) paper, etc. may be used.

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, process simplification and cost reduction are achieved, as well as slimming effect and heat resistance durability effects 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 laminated, and may have a structure in which at least one coverlay is laminated 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 and 2 denote the same members. Hereinafter, in the description of FIG. 3, content overlapping with FIGS. 1 and 2 will not be described again, and only differences will be described.

Referring to FIG. 3 , the flexible metal composite substrate 300 of the present invention includes 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 these (100, 40, 100) may be integrally laminated.

Specifically, in the flexible metal composite substrate 300 , one surface of the metal layer 40 is in close contact with the first adhesive layer 20 , and the other surface 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, the first and second thermoplastic polymer films 10 are disposed on the outermost surface of the composite substrate, respectively. In this case, the members 100 , 10 , and 20 indicated by the same reference numerals 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), a copper alloy (alloy), aluminum (Al), and an aluminum alloy, and the metal component included in the alloy (alloy) is not particularly limited. , a conventional metal known in the art may be used. 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 of the final product, electrical properties, and mechanical properties. Further, 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 a double-sided average roughness (Ra) of 0.1 μm or less in a direction perpendicular to the rolling direction. Since there may be a crack issue when using relatively thick 35 μm or 70 μm copper foil, the percentage of use of rolled copper foil compared to electrodeposited copper foil may be high.

In addition, the metal layer 40 may form a circuit pattern portion 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 depending on the intended use. Although not shown in FIG. 3, 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 for insulating the circuit layer ( PSR) layer is preferably 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 , , it may have a structure that electrically conducts 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, 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 the binder used as an adhesive layer component By providing (100), it is possible to simultaneously secure safety and excellent physical properties when applied to a battery of an electric vehicle.

According to one embodiment of the present invention, the 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 It can be /cm.

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

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

For example, a first coverlay film 100 and a second coverlay film 10 are respectively disposed on the upper and lower surfaces of the metal layer 40 as a center, but the first adhesive layer 20 - the metal layer 40 ) - The second adhesive layer 20 is disposed to face each other and then bonded to form a laminate. At this time, 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 is applied to thermocompression. At this time, the thermocompression conditions are not particularly limited, and, for example, after configuring the above-mentioned laminate and putting it into a press, a temperature of about 120 to 160 ℃, a pressure of 7 to 60 kgf/cm ² , and 50 to 120 minutes conditions It can be thermocompressed under At this time, when a thermoplastic polymer film having a low glass transition temperature (Tg) is provided, it is preferable to press thermocompression at a relatively low temperature, for example, 150° C. or less, specifically 135 to 150° C.

On the other hand, in the present invention, one metal layer 40 and two coverlay films 100 are sequentially stacked and then the flexible metal composite substrate 300 is manufactured through a thermocompression bonding process. 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 also falls 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 battery disposed on the bottom of a vehicle, specifically, an electric vehicle. In addition, it can be applied to various electronic and communication devices to improve safety and various characteristics.

Hereinafter, the present invention will be described in detail with reference to Examples, but the following Examples and Experimental Examples are merely illustrative of one aspect of the present invention, and the scope of the present invention is not limited to the Examples and Experimental Examples below.

[Reference example]

The physical 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 μm 25 25 25 25 density g/cm ³ 1.25 1.40 1.36 1.42 to 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

The components of the thermosetting adhesive composition were prepared by mixing according to the ratios of the formulation examples in [Table 2] and [Table 3] below. 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), an adhesive layer was formed by coating the thermosetting adhesive composition of Example 1-1 to a thickness of 38 μm after drying, and a release paper was placed on the adhesive layer to a thickness of 88 A coverlay film of μm (excluding the thickness of the release paper) was prepared.

1-3. Manufacture of flexible metal composite substrate

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

The characteristics 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
profit A-1 Thermosetting resin ¹ : Brominated epoxy resin, Kukdo Chemical YDB-400
(EEW: 380-420 g/eq, softening point: 64-74°C, 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°C) A-3 Thermosetting resin ³ : polyfunctional phenol novolac epoxy resin, Kukdo Chemical YDPN-638 (EEW: 170-190 g/eq, n = 1.6) thermoplastic
profit B Acrylonitrile-butadiene rubber (NBR) filler C Phosphorus-based 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 curing agent, 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 peel 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, the coverlay films and flexible metal composite substrates of Comparative Examples 1 and 2 were prepared in the same manner as in Example 1, respectively.

[Experimental Example 1]

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

1) Flame retardant 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 the test method (V method) of UL94.

2) Peel Strength (P/S) evaluation

In accordance with JIS C6471 (or IPC-TM-650 2.4.8 evaluation standard), the adhesive layer is applied at a temperature of 25°C with respect to the surface of the PEN film and the surface of the copper foil layer of the composite substrate at 90 degrees each in the direction of 50 mm/ The lowest value of the force required to peel at a rate of minutes was measured and expressed as the peel strength.

3) Heat resistance (solder floating) evaluation

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

4) Crack evaluation

The composite substrate was repeatedly folded 180 degrees for 5 times, and then cracks were checked. When cracks occurred and cut, X was evaluated, when cracks occurred but cutting did not occur, △, and when no cracks occurred, it was evaluated as ○.

As a result of the experiment, in the case of Examples 1 to 9 including an adhesive layer that satisfies a specific mixing ratio while a thermoplastic polymer film was provided, a thermosetting resin and a thermoplastic resin were mixed, flame retardancy, heat resistance, adhesion, and crack characteristics in terms of All were found to be 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
Including; an adhesive layer formed on the thermoplastic polymer film;
The adhesive layer is formed from an adhesive composition comprising a thermosetting resin, a thermoplastic resin, a curing agent and an inorganic filler,
The thermosetting resin is
A first epoxy resin having an epoxy equivalent weight (EEW) of 250 to 430 g/eq; and
Containing at least one of a second epoxy resin having an epoxy equivalent weight (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 thermosetting resin is included in an amount of 40 to 70 parts by weight based on 100 parts by weight of the adhesive composition,
The first epoxy resin contained in the thermosetting resin is included in an amount of 30 to 50 parts by weight, the coverlay film. According to claim 1,
The thermoplastic polymer film is a coverlay film having a glass transition temperature (Tg) of 250 ℃ or less. According to claim 1,
The thermoplastic polymer film is a coverlay film that satisfies at least one of the following (i) to (iv) physical properties:
(i) a density greater than or equal to 1.15 g/cm ³ and less than 1.42 g/cm ³ as measured in accordance with ASTM D 1505;
(ii) at least 75% elongation at break as measured in accordance with ASTM D 882;
(iii) 2% or less of heat shrinkage in the longitudinal and transverse directions of the film (150° C., 30 minutes); and
(iv) less than 1.0% moisture absorption According to claim 1,
The thermoplastic polymer film may include polyethylene naphthalate (PEN), polyethylene terephtalate (PET), polycyclohexadimethylene terephtalate (PCT), polytrimethyleneterephtalate (PTT), poly butylene terephthalate (PBT), polytrimethylene naphthalate (PTN), polybutylene naphthalate (PBN), polycyclohexadimethylene naphthalate (PCN), and polycyclohexadimethylene naphthalate (PCN) A coverlay film comprising at least one polyester-based polymer selected from the group consisting of hexanedimethylene cyclohexadimethylcarboxylate (polycyclohexadimethylene cyclohexadimethylcarboxylate, PCC). According to claim 1,
The thermoplastic polymer film may include at least one aromatic sulfone polymer selected from the group consisting of polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), and polyether sulfone (PES), or polyether ether ketone (PEEK). ), a coverlay film comprising. delete According to claim 1,
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. According to claim 1,
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 styrene (styrene)-butadiene (butadiene)-coverlay film comprising at least one selected from the group consisting of ethylene resin (SEBS). According to claim 1,
The mixing ratio of the thermosetting resin and the thermoplastic resin is 20 to 80: 80 to 20 parts by weight based on 100 parts by weight of the polymer resin. According to claim 1,
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. According to claim 1,
Coverlay film further comprising a release layer disposed on the adhesive layer. 12. The method of claim 11,
The release layer is a release paper (release paper), and a coverlay film comprising any one of a release polymer film. According to claim 1,
The thickness of the thermoplastic polymer film is 12 to 125 μm,
The thickness of the adhesive layer is 5 to 100 μm, the coverlay film. A first thermoplastic polymer film having a melting point (T _m ) of 300° C. or less; and a first coverlay film comprising 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 comprising a second adhesive layer; and
and a metal layer disposed between the first coverlay film and the second coverlay film, and these are integrally laminated,
At least one of the first coverlay film and the second coverlay film is a coverlay film according to any one of claims 1 to 5, and claims 7 to 13, a flexible metal composite substrate. 15. The method of claim 14,
One surface of the metal layer is in close contact with the first adhesive layer, and the other surface is in close contact with the second adhesive layer. 15. 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,
The peel strength value of the first adhesive layer with respect to the first thermoplastic polymer film is 1.0 kgf/cm or more. 15. The method of claim 14,
The metal layer is a flexible metal composite substrate selected from the group consisting of copper (Cu), a copper alloy, aluminum (Al) and an aluminum alloy. 15. The method of claim 14,
The metal layer is a flexible metal composite substrate of a copper foil or aluminum foil having an average roughness (R _a ) of 0.1 μm or less on both sides. 15. The method of claim 14,
The thickness of the metal layer is 9 to 105 ㎛, a flexible metal composite substrate. 15. The method of claim 14,
The metal layer is a flexible metal composite substrate comprising at least one circuit pattern patterned in a predetermined shape. 15. The method of claim 14,
Flexible metal composite substrate applied to batteries of electric vehicles. (i) preparing a thermoplastic polymer film;
(ii) coating and drying a thermosetting adhesive composition on the thermoplastic polymer film to form an adhesive layer; 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 comprises a thermosetting resin, a thermoplastic resin, a curing agent and an inorganic filler,
The thermosetting resin is
A first epoxy resin having an epoxy equivalent weight (EEW) of 250 to 430 g/eq; and
Containing at least one of a second epoxy resin having an epoxy equivalent weight (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 thermosetting resin is included in an amount of 40 to 70 parts by weight based on 100 parts by weight of the thermosetting adhesive composition,
The method for producing the coverlay film according to claim 1, wherein the first epoxy resin contained in the thermosetting resin is included in an amount of 30 to 50 parts by weight. 23. The method of claim 22,
The roll lamination process of step (iii) is, above the glass transition temperature (Tg) of the thermoplastic polymer, the melting point (T _m ) Method of manufacturing a coverlay film carried out at a temperature below the temperature.

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