Method for continuously manufacturing flexible metal laminate including thick film-type insulating layer

Abstract

The present invention provides a method for continuously manufacturing a metal laminate including a thick film-type insulating layer having a thickness of 50 μm or greater. By applying a belt press to roll-to-roll processing and simultaneously optimizing conditions for the belt press, the present invention not only enables a flexible metal laminate including a thick film-type insulating layer to be easily manufactured through a single continuous process but also can ensure reduced manufacturing time, increased productivity, and reliability of a final product simultaneously.

Description

Method for manufacturing a continuous flexible metal laminate including a thick-film insulating layer

[0001] The present invention relates to a method for manufacturing a continuous metal laminate including a thick-film insulating layer having a thickness of 50 ㎛ or more.

[0002]

[0003] Flexible Copper Clad Laminate (FCCL) is primarily used as a substrate for flexible printed circuit boards (FPCBs), but is also used in applications such as surface heating elements, electromagnetic shielding materials, flat cables, and packaging materials. As electronic devices using printed circuit boards become increasingly smaller, denser, and more efficient, the use of FCCL is increasing.

[0004] The above flexible copper-clad laminate is generally composed of a polyimide-based insulating layer and a copper foil layer. Generally, flexible copper-clad laminate is mass-produced by the roll-to-roll method, but due to the process limitations of the aforementioned roll-to-roll method, it has been difficult to thicken the insulating layer to a thickness of 50 ㎛ or more. To solve this problem, if a batch-type pressing process is performed after the roll-to-roll process, it is possible to manufacture a flexible copper-clad laminate including a thick-film insulating layer, but the additional process leads to an increase in production cost and a decrease in production efficiency. In addition, since the adhesiveness between the multiple insulating layers for forming the thick-film insulating layer by the roll-to-roll method is low, delamination of the final flexible copper-clad laminate and a decrease in the reliability of the final product inevitably occur.

[0005]

[0006] The present invention has been devised to solve the above-mentioned problems, and by applying a belt press to the conventional roll-to-roll method and simultaneously introducing a specific adhesive layer and / or optimizing the belt press conditions, it is possible to easily manufacture a flexible metal laminate having a thick-film insulating layer through a single continuous process, and at the same time, shorten the manufacturing time, increase productivity, and ensure reliability of the final product.

[0007] Other objects and advantages of the present invention can be more clearly explained by the detailed description of the invention and the claims below.

[0008]

[0009] In order to achieve the above object, the present invention provides a method for manufacturing a flexible metal laminate including a thick-film insulating layer having a thickness of 50 ㎛ or more, comprising the steps of (i) preparing at least one roll-type metal foil; (ii) preparing a plurality of roll-type insulating films; and (iii) passing the metal foil and the insulating film, which are continuously supplied in a roll-to-roll manner, through a belt press to collectively press and laminate them; wherein at least one of the metal foil and the insulating film includes an adhesive layer formed on one or both sides.

[0010] In one embodiment of the present invention, the metal foil may be copper foil or resin-coated copper foil (RCC).

[0011] In one embodiment of the present invention, step (i) may include preparing at least two metal foils, and the at least two metal foils may have the same thickness and surface roughness.

[0012] In one embodiment of the present invention, the roughness (Rz) of the metal foil may be 0.5 to 3 ㎛, and the thickness may be 1 to 50 ㎛.

[0013] In one embodiment of the present invention, when there are at least two metal foils, in step (ii), a plurality of insulating films may be placed between the metal foils.

[0014] In one embodiment of the present invention, the resin-formed surface of the resin-attached copper foil or the surface of the insulating film may be plasma-treated.

[0015] In one embodiment of the present invention, the adhesive layer may be formed on one side of the metal foil in contact with the insulating film, one side of the insulating film in contact with the metal foil, or one or both sides of a plurality of insulating films in contact with each other.

[0016] In one embodiment of the present invention, the adhesive layer may be at least one selected from the group consisting of a thermoplastic polyimide-based adhesive and an epoxy resin-based adhesive.

[0017] In one embodiment of the present invention, in the step (ii), the thickness of a single insulating film among the plurality of insulating films may be 50 μm or less, and the thickness of the insulating layer in which the plurality of insulating films are integrated may be 50 to 200 μm.

[0018] In one embodiment of the present invention, the belt press of step (iii) may include: an upper belt having a plurality of rollers; a lower belt having a plurality of rollers; a heating device that applies heat, pressure, or both to an object passing between the upper belt and the lower belt; and a cooling device that can cool an object passing between the upper belt and the lower belt.

[0019] In one embodiment of the present invention, the belt press of step (iii) may be a hydraulic belt press or a roll-type belt press.

[0020] In one embodiment of the present invention, the curing temperature of the epoxy resin adhesive may be equal to or lower than the belt temperature applied to the belt press.

[0021] In one embodiment of the present invention, the epoxy resin adhesive layer before passing through the belt press may be in a semi-cured state with a degree of curing of 50% or less, and the epoxy resin adhesive layer after passing through the belt press may be in a fully cured state with a degree of curing of 70% or more.

[0022] In one embodiment of the present invention, the thermoplastic polyimide adhesive layer before passing through the belt press may be in a fully cured state with a degree of curing of 70% or more.

[0023] In one embodiment of the present invention, when the adhesive layer is an epoxy resin adhesive, the step (iii) may be pressed under conditions of a belt temperature of 180 to 380°C, a pressure of 10 to 80 bar, and a conveying speed of 1 to 8 m / min.

[0024] In one embodiment of the present invention, when the adhesive layer is a thermoplastic polyimide-based adhesive, the step (iii) may be pressed under conditions of a belt temperature of 300 to 380°C, a pressure of 10 to 80 bar, and a conveying speed of 1 to 8 m / min.

[0025] As one embodiment of the present invention, the manufacturing method may be a method in which a roll-type flexible metal laminate including a thick film-type single insulating layer is formed by a continuous process comprising steps (i) to (iii).

[0026] In one embodiment of the present invention, the flexible metal laminate may have (i) an interfacial adhesive force between a plurality of insulating films of 0.8 kgf / cm or more, and (ii) an adhesive force between the metal foil and the insulating film of 0.5 to 1.5 kgf / cm.

[0027] In addition, the present invention provides a method for manufacturing a continuous flexible metal laminate including a thick-film insulating layer having a thickness of 50 ㎛ or more, comprising the steps of: (a) preparing two roll-type resin-attached metal foils and arranging them so that the resin-forming surfaces of the resin-attached metal foils face each other; and (b) passing two resin-attached metal foils continuously supplied in a roll-to-roll manner through a belt press to collectively press and laminate them.

[0028] In one embodiment of the present invention, the resin layer formed on the surface of the resin-attached metal foil may include at least two resin layers.

[0029] In one embodiment of the present invention, the thickness of the resin layer included in the resin-attached copper foil may be 50 ㎛ or less, and the total thickness of the insulating layer in which at least two opposing resin layers are integrated may be 50 to 200 ㎛.

[0030]

[0031] As one embodiment of the present invention, by applying a belt press to a conventional roll-to-roll continuous method and simultaneously introducing a specific adhesive layer and / or optimizing the conditions of the belt press, it is possible to easily manufacture a flexible metal laminate having a thick-film insulating layer through a single continuous process, and at the same time, shorten the manufacturing time, increase productivity, and secure excellent quality and high reliability of the final product.

[0032] In addition, the present invention resolves the problem of a spaced arrangement from the press heat source resulting from sheet-shaped pressing in the conventional batch type, and the resulting manufacturing conditions and unevenness of the final product, and secures the uniformity and reliability of the final product through the application of the same press conditions to the entire section, which is an advantage of the roll-to-roll method.

[0033] Accordingly, the flexible metal laminate according to the present invention can be usefully applied to a low-k flexible metal laminate (FCCL) or flexible printed circuit board (FPCB) for a 5G mobile device, and can be applied without limitation to various other technical fields.

[0034] The effects according to the present invention are not limited to those exemplified above, and more diverse effects are included in this specification.

[0035]

[0036] FIG. 1 is a drawing of a manufacturing process of a flexible metal laminate according to one embodiment of the present invention.

[0037] Figure 2 is a drawing of a manufacturing process of a flexible metal laminate according to another embodiment of the present invention.

[0038] Figure 3 is a drawing of a manufacturing process of a flexible metal laminate according to another embodiment of the present invention.

[0039] Figure 4 is a cross-sectional view of a hydraulic belt press according to one embodiment of the present invention.

[0040] Figure 5 is a cross-sectional view of a roll-type belt press according to another embodiment of the present invention.

[0041] <Explanation of symbols>

[0042] Flexible metal laminates 100, 200, 300

[0043] Metal foil 10

[0044] Resin-attached copper foil 20

[0045] Copper 21, resin layer 22

[0046] Insulating film 30

[0047] Adhesive layer 40

[0048] Thick film insulation layer 50

[0049] Metal foil feed roller 60

[0050] Insulating film supply roller 70

[0051] Belt press 80

[0052] Upper belt 81

[0053] Lower belt 82

[0054] Upper roller 81a

[0055] Lower roller 82a

[0056] Heating device 83

[0057] Cooling device 84

[0058] Winding roller 90

[0059]

[0060] Hereinafter, the present invention will be described in detail. Embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. The following embodiments may be modified in various ways, and the scope of the present invention is not limited to the following embodiments. Throughout this specification, the same reference numerals denote the same structures.

[0061] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0062] Additionally, throughout this specification, when a part is said to "include" a component, this does not exclude other components, but rather means that other components may be included, unless otherwise specifically stated. Furthermore, throughout this specification, "above" or "on" means not only when the target part is located above or below it, but also when there is another part in between, and does not necessarily mean that the target part is located above the direction of gravity.

[0063]

[0064] <Method for manufacturing continuous flexible metal laminates>

[0065] One embodiment of the present invention is a method for manufacturing a flexible metal laminate, and more specifically, a method for manufacturing a continuous flexible metal laminate having a thick film-type insulating layer of 50 ㎛ or more.

[0066] This thick-film insulating layer must be formed by arranging a metal foil and multiple PI insulating films and then heating and pressurizing them to become integrated. However, with the conventional roll-to-roll continuous method, not only is it impossible to completely laminate and integrate multiple insulating films in a single process, but even if it is manufactured, delamination between layers of insulating films, resulting in a decrease in the physical properties and reliability of the final product, inevitably occurs.

[0067] In addition, a separate batch type pressurization process can be performed after the roll-to-roll continuous process, but in this case, the production cost of the manufacturing process increases and production efficiency decreases, and in the batch type, the separation from the press heat source caused by sheet-type pressing, and the resulting unevenness in manufacturing conditions and final products, etc. fundamentally occur.

[0068] Accordingly, the present invention aims to realize the advantages of both the roll-to-roll continuous process and the belt press process by applying a belt press during a conventional roll-to-roll continuous process, while simultaneously introducing a specific adhesive layer and / or optimizing the belt press conditions. Accordingly, not only can a flexible metal laminate having a thick-film insulating layer be manufactured through a single continuous process, but also manufacturing time can be shortened, productivity increased, and final product reliability can be secured simultaneously.

[0069] Hereinafter, a method for manufacturing a flexible metal laminate according to the present invention will be described. However, the present invention is not limited to the manufacturing method described below, and each process step may be modified or selectively combined as needed.

[0070] The method for manufacturing the above flexible metal laminate can be manufactured according to three main embodiments depending on whether an insulating film is used to form a thick-film insulating layer and the type of metal foil.

[0071] Specifically, a first embodiment of manufacturing the flexible metal laminate may comprise (i) a step of preparing at least one roll-type metal foil ('S100'); (ii) a step of preparing a plurality of roll-type insulating films ('S200'); and (iii) a step of passing the metal foil and the insulating film, which are continuously supplied in a roll-to-roll manner, through a belt press to collectively press and laminate them ('S300').

[0072] FIG. 1 is a manufacturing process diagram of a flexible metal laminate (100) according to the first embodiment of the present invention. Hereinafter, the manufacturing method will be described step by step with reference to FIG. 1.

[0073] (i) Metal foil preparation stage ('S100 stage')

[0074] In step S100, at least one metal foil for forming a flexible metal laminate (100) is prepared.

[0075] Since the present invention is performed by a roll-to-roll continuous process, the metal foil (10) is configured as a roll type and is continuously supplied from a metal foil supply roller (60).

[0076] The metal foil (10) above can be used without any special limitation as long as it is a typical metal component applied to flexible metal laminates or flexible printed circuit boards in the relevant field. For example, the metal foil (10) can be a metal thin film selected from the group consisting of copper (Cu), iron (Fe), nickel (Ni), titanium (Ti), aluminum (Al), silver (Ag), and gold (Au), or an alloy thin film of two or more types. Preferably, the metal foil (10) can be a copper foil or a resin-bonded copper foil (RCC) that has excellent electrical conductivity and is inexpensive. Any typical copper foil known in the relevant field can be used as the copper foil, and all copper foils manufactured by a rolling method and an electrolytic method can be used. In addition, a copper foil that has been treated to prevent surface oxidation and corrosion can be used.

[0077] At this time, if one metal foil (10) is used, a single-sided flexible metal laminate is manufactured, and if at least two metal foils (10) are used, a double-sided flexible metal laminate is manufactured. If at least two metal foils are prepared in the step S100, at least two metal foils (10) may have the same thickness and surface roughness. At this time, the surface of the metal foil (10) in contact with the insulating film may be a roughened surface having a predetermined surface roughness, and the average roughness (Rz) of the roughened surface may be about 0.5 to 3 ㎛.

[0078] The thickness of the above metal foil (10) is not particularly limited, and may be in the range of about 1 to 50 ㎛, specifically, in the range of about 1 to 30 ㎛, taking into consideration the thickness and mechanical properties of the final flexible metal laminate (100).

[0079] (ii) Multiple insulation film preparation steps ('S200 steps')

[0080] In step S200, a plurality of insulating films (30) are prepared to form a flexible metal laminate.

[0081] Since the present invention is performed by a roll-to-roll continuous process, the insulating film (30) is also configured as a roll type and is continuously supplied from a plurality of insulating film supply rollers (70). At this time, when at least two metal foils are used in the step S100, the plurality of insulating films are placed between at least two metal foils.

[0082] The number of the above insulating films (3) is not particularly limited, and the number and thickness of the insulating films can be freely selected considering the thickness of the thick-film insulating layer to be formed (e.g., 50 ㎛ or more). For example, when the thickness of the insulating film is 25 ㎛ or more, two or more can be used, and when it is 20 ㎛ or less, three or more can be used.

[0083] The insulating film (30) above can be used without any special limitation as long as it is a component having typical insulating properties applied to flexible metal laminates or flexible printed circuit boards in the relevant field. For example, the insulating film (30) may include at least one selected from the group consisting of polyimide, polyamide, polyamideimide, polyamic acid resin, polyester, polyphenylene sulfide, polyester sulfone, polyether ether ketone, aromatic polyamide, polycarbonate, and polyarylate. Preferably, it is a polyimide (PI) film, or it may be configured by further including a thermosetting resin in a polyimide-based resin.

[0084] For example, the insulating film (30) may be a commercially available polyimide (PI) film. This polyimide film may be in the form of a self-supporting film or sheet, and may be a commercially available general-purpose polyimide (PI) film or a commercially available soluble polyimide (soluble PI). In addition, it may be manufactured by subjecting a diamine compound known in the art to a condensation reaction with an acid dianhydride (e.g., aromatic dianhydride), and then applying and drying / curing the reactant on a substrate. The polyimide film may be surface-treated, such as by matte treatment or corona treatment.

[0085] The thickness of the above insulating film (30) is not particularly limited and can be appropriately adjusted in consideration of the film's handleability, physical rigidity, and thinning of the substrate. For example, the thickness of a single insulating film among the plurality of insulating films (30) is 50 μm or less, specifically 5 to 20 μm, and more specifically 5 to 10 μm. In addition, for the effect of increasing adhesive strength, it is preferable that the surface of the insulating film is plasma-treated.

[0086] Meanwhile, the present invention includes an adhesive layer (40) to increase the adhesive strength between different materials such as adjacent metal foils (10) and insulating films (30), and the interlayer adhesive strength between multiple insulating films (30).

[0087] For example, the adhesive layer (40) may be formed on one side of the metal foil (10) in contact with the insulating film (30), one side of the insulating film (30) in contact with the metal foil (10), or one or both sides of a plurality of insulating films (30) in contact with each other.

[0088] The above adhesive layer (40) may include at least one of a conventional thermosetting resin and a thermoplastic resin known in the art.

[0089] For example, the adhesive layer (40) may be a thermoplastic polyimide-based adhesive. When the thermoplastic polyimide is used as an adhesive layer component, the adhesion between the polyimide insulating layer and the copper foil, which has previously exhibited poor adhesive performance, can be increased, thereby preventing delamination and structural deformation of the flexible copper-clad laminate.

[0090] For another specific example, the adhesive layer (40) may include a thermosetting resin and may further include at least one selected from the group consisting of a thermoplastic resin, a curing agent, and an inorganic filler.

[0091] Non-limiting examples of usable thermosetting resins include at least one selected from the group consisting of epoxy resins, polyurethane resins, alkyd resins, phenol resins, melamine resins, silicone resins, urea resins, vegetable oil-modified phenol resins, xylene resins, guanamine resins, diallyl phthalate resins, vinyl ester resins, unsaturated polyester resins, furan resins, polyimide resins, cyanate resins, maleimide resins, and benzocyclobutene resins. Specifically, the thermosetting resin may be at least one selected from the group consisting of epoxy resins, phenol resins, melamine resins, silicone resins, urethane resins, and urea resins. Preferably, the adhesive layer (30) may be an epoxy resin-based adhesive.

[0092] The epoxy resin may be any conventional epoxy resin known in the art without limitation, and preferably one having two or more epoxy groups and not containing 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, biphenyl type, aralkyl type, naphthol type, dicyclopentadiene type, or mixed forms 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 cocondensed novolac type epoxy resin, naphthol coresol cocondensed novolac 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 aralkyl type epoxy resin, multifunctional phenol resin, naphthol aralkyl type epoxy resin, etc. At this time, the above-mentioned epoxy resin may be used alone or two or more types may be used in combination.

[0093] Non-limiting examples of usable thermoplastic resins include olefin resins, acrylic resins, rubbers, or mixtures thereof. Specific examples include polyethylene, polypropylene, polystyrene, polyimide, Teflon (PTFE), 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 ester resins containing side chains of 1 to 8 carbon atoms (acrylic rubber), or mixtures of one or more thereof.

[0094] The thermoplastic resin described above preferably contains a functional group capable of reacting with an epoxy resin, which is a thermosetting resin. Specifically, the functional group is at least one selected from the group consisting of an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a methoxy group, and an isocyanate group. Such a functional group forms a strong bond with the epoxy resin, thereby improving heat resistance 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 thermal stress relief effects. It is preferable that such a copolymer contains a functional group capable of reacting with an epoxy resin. Specific examples of the functional group include an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a methoxy group, an isocyanate group, a vinyl group, a silanol group, etc., and it is more preferable that the functional group contains a carboxyl group. Specific examples of NBR having the above carboxyl group include PNR-1H (manufactured by JSR Co., Ltd.), Nipol 1072J, and Nipol DN631 (all manufactured by Japan Zeon Co., Ltd.).

[0095] The thermoplastic resin content is not particularly limited, and may range from 1 to 35 wt%, for example, based on the total weight of the adhesive composition, and is preferably 5 to 30 wt%. If it exceeds the above range, sufficient adhesiveness cannot be obtained and heat resistance deteriorates.

[0096] In the present invention, conventional curing agents known in the art can be used without limitation, and can be appropriately selected and used depending on the type of epoxy resin to be used. Non-limiting examples of curing agents that can be used include phenol-based, anhydride-based, dicyanamide-based, and aromatic polyamine curing agents. Non-limiting examples of curing agents that can be used include phenol-based curing agents such as phenol novolac, cresol novolac, bisphenol A novolac, and naphthalene-based curing agents; polyamine-based curing agents such as metaphenylenediamine, diaminodiphenylmethane (DDM), and diaminodiphenylsulfone (DDS), and the like. In this case, these may be used alone or in combination of two or more.

[0097] In the present invention, the content of the curing agent is not particularly limited, and for example, may be in the range of 5 to 10 parts by weight based on the total weight (100 parts by weight) of the adhesive composition.

[0098] The present invention may include conventional inorganic fillers known in the art. Non-limiting examples of usable inorganic fillers include silicas such as natural silica, fused silica, amorphous silica, and crystalline silica; boehmite, alumina, aluminum hydroxide [Al(OH)3], talc, spherical glass, calcium carbonate, magnesium carbonate, magnesia, clay, calcium silicate, titanium oxide, 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. These inorganic fillers may be used alone or in combination of two or more.

[0099] The size of the above-mentioned 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 above-mentioned inorganic filler is not particularly limited, and may be in the range of 5 to 20 parts by weight based on the total weight (100 parts by weight) of the adhesive composition.

[0100] In addition to the above-mentioned components, as long as the inherent properties of the adhesive composition are not impaired, the adhesive composition may further include, if necessary, flame retardants generally known in the art, other thermosetting resins or thermoplastic resins not described above and various polymers such as oligomers thereof, solid rubber particles, or other additives such as ultraviolet absorbers, antioxidants, polymerization initiators, dyes, pigments, dispersants, thickeners, leveling agents, etc.

[0101] For example, the thermosetting adhesive composition constituting the adhesive layer (40) may be a composition including 30 to 50 parts by weight of an epoxy resin; 5 to 40 parts by weight of a thermoplastic resin; 5 to 10 parts by weight of a curing agent (additive); and 5 to 30 parts by weight of an inorganic filler, based on 100 parts by weight of the composition. Here, the epoxy resin can implement chemical resistance and flexibility, and the thermoplastic resin exhibits an effect of improving adhesive strength and flexibility and alleviating thermal stress. At this time, 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 matching 100 parts by weight of the total composition.

[0102] The thickness of the adhesive layer (40) is not particularly limited and can be appropriately adjusted within a range known in the art. For example, the thickness of the adhesive layer (40) may be 2 to 15 μm, and preferably 5 to 12 μm.

[0103] (iii) Merging stage ('S300 stage')

[0104] In step S300, a metal foil (10) and a plurality of insulating films (30) continuously supplied in a roll-to-roll manner are passed through a belt press (80) to be pressed and laminated in batches to manufacture a flexible metal laminate (100) having a thick-film insulating layer (50).

[0105] In order to manufacture a flexible metal laminate having a thick film insulating layer by a single continuous process, the present invention introduces a belt press into the existing roll-to-roll process and simultaneously controls the conditions of the belt press within a predetermined range.

[0106] The belt press process of the above S300 step can be said to be a process in which a laminate in which a metal foil (10) and a plurality of insulating films (30) arranged therebetween are laminated is processed on a belt so that the laminate can have a predetermined thickness, and at the same time, a plurality of insulating films (30) are compressed by a predetermined heating and pressure, so that the metal foil (10) and the insulating film (30), and / or the plurality of insulating films (30) are laminated and integrated, and then cooled to form a thick film-type single insulating layer (50) having a predetermined thickness.

[0107] This belt press (80) can use any belt press device known in the art without limitation, and is not particularly limited in terms of the type of belt press. For example, the belt press may be a hydraulic belt press or a roll-type belt press.

[0108] Here, a hydraulic belt press refers to a method of pressing an object using fluid pressure, and transmits a predetermined temperature and pressure to the belt surface through the fluid filled within the belt. For example, the hydraulic belt press includes a plurality of upper and lower rollers and a pressurized fluid capable of generating an equal pressure on the surfaces of the rollers or in the space between them. The fluid may be any fluid commonly used in the art without limitation, and may include, for example, viscous oil that can be used as a heat medium.

[0109] In addition, the roll-type belt press is a method of transmitting a predetermined temperature and pressure to the belt surface through a plurality of heating rolls arranged inside the belt. Such a belt press includes a plurality of upper rollers and lower rollers, and can be divided into a plurality of compartments with a predetermined interval. For example, it can be divided into a first zone, a second zone, a third zone, etc. in order from a part close to the entrance of the belt press. In the present invention, press processing can be performed by sequentially operating a plurality of compartments referred to as a heating section for heating an object, a cooling section for cooling the object, and / or a metal cooling section, but is not particularly limited thereto.

[0110] For example, a belt press (80) may include an upper belt having a plurality of rollers; a lower belt (82) having a plurality of rollers; a heating device (83) that applies heat, pressure, or both to an object passing between the upper belt and the lower belt; and a cooling device (84) that can cool an object passing between the upper belt and the lower belt.

[0111] The above belt press device (80) includes an upper belt and a lower belt, each having a metallic belt or a belt of a corresponding nature.

[0112] The lower belt has a number of rollers installed within it, some of which act as drive rollers for the lower belt. The upper belt also has a number of rollers installed within it, at least some of which act as drive rollers for driving the upper belt. Furthermore, at least some of the upper rollers and some of the lower rollers have corresponding positions, and can be arranged at predetermined intervals. In other words, a pair of upper rollers and a plurality of lower rollers are configured and operated.

[0113] And the belt press device of the present invention may include a heating device (83) for heating a metal foil (10) and a plurality of insulating films (30). The heating device is not particularly limited as long as it is a common device capable of heating or heating / pressurizing an object in the relevant field, and for example, a heater, a heat medium oil circulation heating device, etc. may be used. Such a heating device may be installed through a surface bearing on the back surface of the belt (upper belt and lower belt) or may be built into each roller. However, the present invention is not particularly limited thereto.

[0114] In addition, the belt press device of the present invention may include a cooling device (84) for cooling the metal foil (10) and the plurality of insulating films (30). The cooling device is not particularly limited as long as it is a common device capable of cooling a high-temperature laminate in the relevant field. For example, a chiller, a water-cooled cooling jacket, or other heat absorption device may be installed to cool the semi-finished product in a heated state. This cooling device, like the heating device, may be installed through a plane bearing on the back surface of the belt (upper belt and lower belt), or may be built into each roller. That is, the belt press device of the present invention may install a heating device and a cooling device to press and integrate a plurality of insulating films under predetermined conditions, or cool the semi-finished product thus produced to produce a final product.

[0115] As a specific example of the above S300 step, when a metal foil (10) and a plurality of insulating films (30) are continuously transported in a roll-to-roll manner and are fed into a belt press (Belt press, 80), they pass between the first upper roller and the lower roller. The gap set between the upper roller and the lower roller substantially determines the height of the laminate in which the metal foil and the plurality of insulating films are laminated, thereby primarily controlling the thickness of the flexible metal laminate.

[0116] Afterwards, it passes through the second upper roller and lower roller, and the third upper roller and lower roller in succession, and the thickness of the thick-film insulating layer and the flexible metal laminate including the same are determined respectively by the gap between the upper and lower rollers it passes through. In the process of passing through the above-described plurality of upper and lower rollers, the laminate of the metal foil (10) and the insulating film (30) is heated by a predetermined heat and pressure generated by the heating device.

[0117] When the laminate is heated by the heat generated from the heating device in this way, adjacent metal foil (10) and insulating film (30), or multiple insulating films (30), are pressed together and combined, and then cooled to form a flexible metal laminate having a thick-film insulating layer (30).

[0118] Meanwhile, the adhesive layer (40) used in the flexible metal laminate (100) according to the present invention is preferably a thermoplastic polyimide-based adhesive or a thermosetting epoxy resin-based adhesive. In the present invention, by precisely controlling the type and degree of curing of the adhesive, the belt temperature applied to the belt press, and predetermined belt conditions, it is possible to simultaneously improve the adhesion, heat resistance, and chemical resistance between adjacent metal foils (10) and insulating films (30), and improve the interface reliability (e.g., adhesion, heat resistance, and chemical resistance) between a plurality of insulating films (30).

[0119] In particular, epoxy resin adhesives are thermosetting resins that form a network structure through cross-linking by undergoing a curing reaction when a certain amount of heat is applied. At this time, by controlling the degree of curing between the epoxy resin adhesive layers before and after passing through the belt press differently, a synergistic effect in terms of adhesive strength and reliability can be achieved. In other words, the process conditions of the belt press are organically controlled so that the uncured or semi-cured epoxy resin adhesive layer passes through the belt press and undergoes a curing reaction of the epoxy resin, thereby reaching a fully cured state.

[0120] For example, before passing through the belt press (80), the epoxy resin adhesive layer may be in a semi-cured state (B-stage) with a degree of curing of 50% or less, specifically 30 to 50%, and after passing through the belt press, the epoxy resin adhesive layer may be in a fully cured state (C-stage) with a degree of curing of 70% or more, specifically 70 to 95%, and more specifically 90% or more. In this case, the upper limit is not particularly limited.

[0121] For another specific example, the belt temperature applied from the belt press (80), specifically the temperature applied from the heating device (83) provided in the belt press (80), can be adjusted to be equal to or lower than the curing temperature of the epoxy resin adhesive. For example, the belt temperature of the belt press can be 180 to 380°C.

[0122] For another specific example, when the adhesive layer (40) is an epoxy resin adhesive, the belt press process of step S300 may be performed under the conditions of a belt temperature of 180 to 380°C, a pressure of 10 to 80 bar, and a conveying speed of 1 to 8 m / min. Specifically, it may be performed under the conditions of a belt temperature of 200 to 360°C, a pressure of 20 to 70 bar, and a conveying speed of 2 to 7 m / min, and more specifically, it is preferably performed under the conditions of a belt temperature of 200 to 250°C, a pressure of 25 to 50 bar, and a conveying speed of 3 to 6 m / min.

[0123] Meanwhile, since the thermoplastic polyimide adhesive in the adhesive layer (40) is in a fully cured state, a separate curing process is not required.

[0124] For example, when the adhesive layer (40) is a thermoplastic polyimide adhesive, the belt press process of step S300 may be performed under conditions of a belt temperature of 300 to 380°C, a pressure of 10 to 80 bar, and a conveying speed of 1 to 8 m / min. Specifically, it may be performed under conditions of a belt temperature of 310 to 370°C, a pressure of 20 to 70 bar, and a conveying speed of 2 to 7 m / min, and more specifically, it is preferably performed under conditions of a belt temperature of 340 to 360°C, a pressure of 25 to 50 bar, and a conveying speed of 3 to 6 m / min.

[0125] By going through the continuous process consisting of the above-described S100 to S300 steps, a roll-type flexible metal laminate (100) including a thick film-type single insulating layer (50) having a thickness of 50 ㎛ or more can be obtained.

[0126]

[0127] Referring to FIG. 2, a method for manufacturing a flexible metal laminate (200) including a thick-film insulating layer according to the present invention will be described. In FIG. 2, the same reference numerals as in FIG. 1 indicate the same configuration.

[0128] In the following description of Fig. 2, any content overlapping with Fig. 1 will not be described again, and only the differences will be described.

[0129] Specifically, referring to FIG. 2, the method for manufacturing a flexible metal laminate (200) according to the second embodiment of the present invention uses a resin-coated copper (RCC, 20) foil as the metal foil, unlike the first embodiment of FIG. 1 that uses a copper foil as the metal foil (10).

[0130] Resin-attached copper foil (RCC, 20) is a copper foil in which a resin layer (22) is arranged on one or both sides of the copper foil (21).

[0131] The copper foil (21) described above can be any conventional copper foil known in the art without limitation, and includes, for example, all copper foils manufactured by rolling and electrolytic methods. Here, the copper foil may be treated with an anti-rust treatment to prevent oxidation and corrosion of the surface.

[0132] In addition, the copper foil (21) may have a predetermined surface roughness (Rz) formed on one surface that comes into contact with the resin layer (22). At this time, the surface roughness (Rz) may be 0.5 ㎛ to 3.0 ㎛, specifically 0.6 ㎛ to 3.0 ㎛. However, it is not limited thereto. The thickness of the copper foil (21) is not particularly limited, and may be in the range of about 1 to 50 ㎛, specifically 1 to 30 ㎛, taking into consideration the thickness and mechanical properties of the final flexible metal laminate (200).

[0133] The resin layer (22) is placed in contact with the surface roughness of the copper foil (21) and can be formed by including a conventional insulating resin known in the art.

[0134] The resin layer (22) may be a single layer or a multi-layer including at least two resin layers. When the resin layer (22) is composed of multiple layers, each layer may be composed of the same or different components, and any resin commonly used in the resin-attached copper foil (RCC) field may be used without limitation. For example, the resin layer (22) may include at least one of a polyimide-based resin and an epoxy resin, and may further include at least one selected from the group consisting of a thermoplastic resin, a curing agent, and an inorganic filler. In addition, at least one layer among the plurality of resin layers (22) may include a typical liquid crystal polymer known in the art. More specifically, the resin layer (22) may be composed of the same or different components as the adhesive layer (40) described below. In this case, when the resin layer (22) is composed of the same components as the adhesive layer (40), the adhesive layer (40) may not be included.

[0135] In addition, in order to increase the adhesive strength, it is preferable that the resin layer forming surface of the resin-attached copper foil is plasma-treated.

[0136] Meanwhile, in the second embodiment of the present invention, an adhesive layer (40) may be further included to increase the adhesive strength between adjacent resin-attached copper foils (20) and insulating films (30), and the interlayer adhesive strength between a plurality of insulating films (30).

[0137] This adhesive layer (40) can be formed on the surface of the resin layer (22) of the resin-attached copper foil (20) that is in contact with the insulating film (30), or on one or both sides of a plurality of insulating films (20) that are in contact with each other.

[0138] The thickness of the adhesive layer (40) is not particularly limited and can be appropriately adjusted within a range known in the art. For example, the thickness of the adhesive layer (40) may be 2 to 15 μm, and preferably 5 to 12 μm.

[0139] In addition, since the description of the material and structure of each component in the second embodiment of FIG. 2 can be applied as is to the description of the flexible metal laminate according to the first embodiment of FIG. 1, individual descriptions thereof are omitted.

[0140]

[0141] Referring to FIG. 3, a method for manufacturing a flexible metal laminate (300) including a thick-film insulating layer according to the present invention will be described. In FIG. 3, the same reference numerals as in FIGS. 1-2 indicate the same configuration.

[0142] In the description of Fig. 3 below, any content overlapping with Figs. 1-2 will not be described again, and only the differences will be described.

[0143] Specifically, referring to FIG. 3, a method for manufacturing a flexible metal laminate (300) according to a third embodiment of the present invention uses a copper foil as a metal foil (10) and, unlike the first embodiment of FIG. 1 that uses a plurality of insulating films (30), uses a resin-coated copper foil (RCC, 20) as a metal foil and does not include a plurality of insulating films.

[0144] Specifically, a third embodiment of manufacturing the flexible metal laminate (300) may include (a) a step of preparing two roll-type resin-attached metal foils and arranging them so that the resin layer-forming surfaces of the resin-attached metal foils face each other ('S400'); and (b) a step of passing two resin-attached metal foils continuously supplied in a roll-to-roll manner through a belt press to collectively press and laminate them ('S500').

[0145] In the third embodiment of the present invention, instead of including a plurality of insulating films forming a thick-film insulating layer, a thick-film insulating layer (50) is formed by pressing and laminating resin layers (22) formed on one surface of two resin-attached metal foils (20).

[0146] The resin layer (22) provided on the surface of the resin-attached metal foil may be a multi-layer including at least two resin layers. Each layer of the plurality of resin layers (22) may be composed of the same or different components, and any resin commonly used in the resin-attached copper foil (RCC) field may be used without limitation. For example, each resin layer (22) may be the same or different, and may independently include at least one of a polyimide-based resin and an epoxy resin, and may further include at least one selected from the group consisting of a thermoplastic resin, a curing agent, and an inorganic filler. In addition, at least one layer of the plurality of resin layers (22) may include a typical liquid crystal polymer known in the art. More specifically, the resin layer (22) may be composed of the same or different components as the adhesive layer (40) described below. In this case, when the resin layer (22) is composed of the same components as the adhesive layer (40), the adhesive layer (40) may not be included.

[0147] For example, the thickness of the resin layer (22) included in the resin-attached copper foil (20) may be 50 ㎛ or less, specifically 3 to 40 ㎛, and more specifically 4 to 30 ㎛. In addition, the total thickness of the insulating layer (50) in which at least two opposing resin layers are integrated may be 50 ㎛ or more, specifically 50 to 200 ㎛, and more specifically 50 to 150 ㎛.

[0148] Meanwhile, in the third embodiment of the present invention, an adhesive layer (40) may be further included to increase the adhesive strength between the resin layer (22) formation surfaces of opposing resin-attached copper foils (20). This adhesive layer (40) may be a thermoplastic polyimide-based adhesive or an epoxy resin-based adhesive, but is not limited thereto.

[0149] The thickness of the adhesive layer (40) is not particularly limited and can be appropriately adjusted within a range known in the art. For example, the thickness of the adhesive layer (40) may be 2 to 15 μm, and preferably 3 to 12 μm.

[0150] In addition, since the description of the material and structure of each component in the third embodiment of FIG. 3 can be applied as is to the description of the flexible metal laminate according to the first-second embodiment of FIG. 1-2, individual descriptions thereof are omitted.

[0151] Meanwhile, the present invention exemplifies a double-sided flexible metal laminate (100, 200, 300) through the three embodiments described above. However, the present invention is not limited thereto, and a single-sided flexible metal laminate formed by using a single copper foil or a single resin-bonded copper foil and multiple insulating films is also within the scope of the present invention. In addition, a form in which the number of multiple insulating films and their lamination order are freely selected according to the purpose, or a form having a multilayer structure other than the exemplified structure by introducing other layers conventional in the art also falls within the scope of the present invention.

[0152]

[0153] <Duplex Metal Laminate>

[0154] Another embodiment of the present invention is a flexible metal clad laminate, specifically a flexible metal clad laminate comprising a thick film insulating layer formed by the single continuous process described above.

[0155] The above flexible metal laminate may have a single-sided or double-sided structure in which a metal layer is disposed on one or both sides of a thick-film insulating layer based on the thick-film insulating layer. More specifically, the metal laminate includes at least one metal layer; and a thick-film insulating layer formed on one side of the metal layer or between the metal layers and having a thickness of at least 50 μm.

[0156] At this time, the composition of the metal layer and the thick film insulating layer are the same as described above, so a separate description thereof is omitted.

[0157] Meanwhile, the flexible metal laminate according to the present invention is differentiated from the conventional metal laminate in that it includes a thick-film insulating layer formed by a plurality of insulating films and an adhesive layer included therebetween. In particular, the flexible metal laminate of the present invention can easily form a thick-film insulating layer even by a single continuous process by applying a belt press to a roll-to-roll process and precisely controlling the components and curing degree of the adhesive layer, the belt temperature applied to the belt press, and predetermined belt conditions, and can simultaneously secure a reduction in manufacturing time, an increase in productivity, and the reliability (e.g., adhesive strength, heat resistance, chemical resistance) of the final product.

[0158] For example, in the flexible metal laminate, the interfacial adhesive strength between the plurality of insulating films according to IPC-TM-650 2.4.9 may be 0.8 kgf / cm or more, and the adhesive strength between the metal foil and the insulating film may be 0.5 to 1.5 kgf / cm. More specifically, the interfacial adhesive strength between the plurality of insulating films may be 1.3 to 2.0 kgf / cm, and the adhesive strength between the metal foil and the insulating film may be 0.9 to 1.3 kgf / cm.

[0159]

[0160] Printed circuit board

[0161] Another embodiment of the present invention is a printed circuit board, specifically a flexible printed circuit board (FPCB) including the aforementioned thick film type insulating layer.

[0162] The printed circuit board may be a single-layer or multi-layer printed circuit board including at least one metal circuit pattern. Specifically, the printed circuit board includes a flexible metal laminate, and at least one metal foil included in the flexible metal laminate may have a circuit pattern formed thereon, and the thick-film insulating layer serves as an insulating support member. Here, the flexible metal laminate may be the aforementioned roll-type flexible metal laminate itself, or may be a unit obtained by cutting the roll-type flexible metal laminate into a predetermined unit.

[0163] The printed circuit board according to the present invention can be manufactured by a method known in the art. For example, the printed circuit board can be manufactured by continuously supplying a roll-type flexible metal laminate using a roll-to-roll device and a belt press, opening a hole in the flexible metal laminate to perform through-hole plating, and then etching a metal foil (e.g., copper foil) containing a plating film to form a circuit.

[0164] The flexible metal laminate and printed circuit board of the present invention described above can exhibit high adhesive strength, excellent heat resistance, and chemical resistance. Accordingly, the flexible metal laminate and printed circuit board of the present invention can be usefully used as a metal laminate and / or printed circuit board applied to various electrical and electronic devices such as mobile communication devices handling high-frequency signals of 1 GHz or higher, their base station devices, servers, routers, and other network-related electronic devices, and large-scale computers, and is particularly preferably applied to a low-k flexible metal laminate (FCCL) for 5G mobile devices. In addition, it can be applied to various technical fields requiring high adhesive strength, excellent heat resistance, chemical resistance, etc.

[0165]

[0166] Hereinafter, the present invention will be described in detail through examples. However, the following examples are only illustrative of the present invention, and the present invention is not limited to the following examples.

[0167]

[0168] [Example 1A: 1-9]

[0169] Two roll-type copper foils [thickness: 12 ㎛, roughness (Rz): 2.5 ㎛ or less] continuously supplied from a copper foil supply roller were prepared.

[0170] Additionally, three polyimide films (thickness: 50 μm) continuously supplied from an insulating film supply roller were prepared. At this time, a thermoplastic polyimide adhesive layer (thickness: 6 μm) was formed on both sides of the polyimide films.

[0171] The above-mentioned roll-type copper foil and roll-type insulating film were continuously conveyed through conveying rollers and then passed through a hydraulic belt press (Belt press) as shown in Fig. 4 to be collectively pressed and laminated to manufacture a roll-type flexible metal laminate. The thickness of the thick-film insulating layer included in the manufactured flexible metal laminate was 150 μm. The specific conditions of the belt press performed in this example were controlled as shown in Table 1 below.

[0172]

[0173] [Comparative Example 1A: 1]

[0174] A flexible metal laminate according to Comparative Example 1A-1 was manufactured in the same manner as Example 1A-1, except that the thermoplastic polyimide adhesive layer was not included, as shown in Table 1 below.

[0175]

[0176] [Comparative Example 1A: 2]

[0177] A flexible metal laminate according to Comparative Example 1A-2 was manufactured in the same manner as Example 1A-3, except that the thermoplastic polyimide adhesive layer was not included, as shown in Table 1 below.

[0178]

[0179] [Comparative Example 1A: 3]

[0180] A flexible metal laminate according to Comparative Example 1A-3 was manufactured in the same manner as in Example 1A-1, except that the flexible metal laminate was manufactured through a general roll-to-roll process without using a hydraulic belt press.

[0181]

[0182] [Comparative Example 1A: 4]

[0183] A flexible metal laminate according to Comparative Example 1A-4 was manufactured in the same manner as Example 1A-3, except that the flexible metal laminate was manufactured through a roll-to-roll process without using a hydraulic belt press.

[0184]

[0185] [Experimental Example 1A]

[0186] The properties of the flexible copper-clad laminates manufactured in Examples 1 to 9 of Example 1A and 1 to 4 of Comparative Example 1A were measured according to the following measurement method, and the results are shown in Table 1 below.

[0187] 1) Evaluation of adhesion between insulating films

[0188] The adhesion was measured using an adhesive strength measuring device according to the test standard of IPC TM-650.2.4.9.

[0189] 2) Evaluation of adhesion between insulating film and copper foil

[0190] The adhesion was measured using an adhesive strength measuring device according to the test standard of IPC TM-650.2.4.9.

[0191] 3) Heat resistance evaluation

[0192] The flexible copper-clad laminate was cut to a size of 50 mm x 50 mm, placed in a soldering bath at 288°C for 10 seconds in accordance with the test standard of IPC TM-650 2.4.13, and then taken out and visually evaluated for its appearance. If delamination or blisters occurred, it was judged as NG.

[0193] 4) Appearance evaluation

[0194] The external appearance of the flexible copper-clad laminate was visually evaluated. If wrinkles or lifting occurred, it was judged as NG.

[0195]

[0196] As shown in Table 1 above, in the present invention, by applying a belt press to the roll-to-roll process, and further introducing a thermoplastic polyimide adhesive layer between the copper foil and the insulating film, and optimizing the belt press process conditions, it was confirmed that a flexible metal laminate having a thick-film insulating layer can be easily manufactured through a single continuous process, and that the physical properties of the manufactured flexible metal laminate are also excellent. In particular, when the belt press process conditions are precisely controlled within a predetermined range, as in 1 to 4 of Example 1A, a flexible metal laminate excellent in adhesive strength, heat resistance, and appearance characteristics can be manufactured.

[0197]

[0198]

[0199] [Example 1B: 10-17]

[0200] Two copper foils [thickness: 12 ㎛, roughness (Rz): 2.5 ㎛ or less] continuously supplied from a copper foil supply roller were prepared.

[0201] In addition, three polyimide films (thickness: 50 μm) were prepared and continuously supplied from an insulating film supply roller. At this time, an epoxy resin adhesive layer (thickness: 6 μm) was formed on both sides of the polyimide film. At this time, the adhesive layer was in a semi-cured state.

[0202] The above-mentioned roll-type copper foil and roll-type insulating film were continuously conveyed through a conveying roller, and then passed through a hydraulic belt press (Belt press) as shown in Fig. 4 below to be pressed and laminated in batches to manufacture a roll-type flexible metal laminate. At this time, the thickness of the thick-film insulating layer included in the flexible metal laminate was 150 μm. The conditions of the belt press performed in this example were controlled as shown in Table 2 below.

[0203]

[0204] [Comparative Example 1B: 5~6]

[0205] Except for not including an epoxy resin adhesive layer as shown in Table 2 below, the same procedure as in Example 1B 10 to 11 was performed to manufacture flexible metal laminates according to Comparative Example 1B 5 to 6, respectively.

[0206]

[0207] [Experimental Example 1B]

[0208] The characteristics of the flexible copper-clad laminates manufactured in Examples 10 to 17 of Example 1B and Examples 5 to 6 of Comparative Example 1B were measured according to the following measurement method, and the results are shown in Table 2 below.

[0209] At this time, the evaluation of the adhesive strength between the insulating films, the evaluation of the adhesive strength between the insulating film and the copper foil, and the evaluation of the appearance were each evaluated in the same manner as in Experimental Example 1A.

[0210]

[0211] As shown in Table 2 above, in the present invention, by applying a belt press to a roll-to-roll process, and furthermore, by introducing an epoxy resin adhesive layer between the copper foil and the insulating film, and by optimizing the belt press process conditions, it was confirmed that a flexible metal laminate having a thick film type insulating layer can be easily manufactured by a single continuous process, and that the physical properties of the manufactured flexible metal laminate are also excellent.

[0212] Meanwhile, Example 1B 16 can be used as a control group when comparing the properties of a flexible metal laminate according to the degree of curing of the epoxy adhesive layer after passing through a heating belt.

[0213]

[0214] [Example 2A: 1-9]

[0215] A roll-type flexible metal laminate having a thick-film insulating layer according to Example 2A 1-9 was manufactured in the same manner as in Example 1A 1-9, except that two roll-type resin-bonded copper foils [thickness: 12 ㎛, roughness (Rz): 2.5 ㎛ or less] were used instead of two roll-type copper foils. The thickness of the thick-film insulating layer included in the manufactured flexible metal laminate was 150 ㎛. The specific conditions of the belt press performed in this example were controlled as shown in Table 3 below.

[0216]

[0217] [Comparative Example 2A: 1~2]

[0218] A flexible metal laminate according to Comparative Example 2A 1-2 was manufactured in the same manner as in Example 2A 1 and 3, except that the thermoplastic polyimide adhesive layer was not included, as shown in Table 3 below.

[0219]

[0220] [Experimental Example 2A]

[0221] The properties of the flexible copper-clad laminates manufactured in Examples 1 to 9 of Example 2A and Comparative Example 2A 1 to 2 were measured according to the following measurement method, and the results are shown in Table 3 below.

[0222] At this time, the evaluation of the adhesive strength between the insulating films, the evaluation of the adhesive strength between the insulating film and the copper foil, and the evaluation of the appearance were each evaluated in the same manner as in Experimental Example 1A.

[0223]

[0224] As shown in Table 3 above, except that the copper foil was changed to a resin-bonded copper foil, it was found that by applying a belt press to the roll-to-roll process as in Example 1A and precisely controlling the belt press process conditions within a predetermined range, a flexible metal laminate having excellent adhesive strength, heat resistance, and appearance characteristics could be manufactured.

[0225]

[0226] [Example 2B: 10-17]

[0227] A roll-type flexible metal laminate having a thick-film insulating layer according to Example 2B 10-16 was manufactured in the same manner as in Example 1B 10-17, except that two roll-type resin-bonded copper foils [thickness: 12 ㎛, roughness (Rz): 2.5 ㎛ or less] were used instead of two roll-type copper foils. The thickness of the thick-film insulating layers included in the manufactured flexible metal laminates was 150 ㎛ each. The specific conditions of the belt press performed in this example were controlled as shown in Table 4 below.

[0228]

[0229] [Comparative Example 2B: 3~4]

[0230] Except for not including an epoxy resin adhesive layer as shown in Table 4 below, the same procedure as in Examples 10 and 12 of Example 2B was followed to manufacture flexible metal laminates of Comparative Example 2B 3 to 4, respectively.

[0231]

[0232] [Experimental Example 2B]

[0233] The properties of the flexible copper-clad laminates manufactured in Examples 10 to 17 of Example 2B and Examples 3 to 4 of Comparative Example 2B were measured according to the following measurement method, and the results are shown in Table 4 below.

[0234] At this time, the evaluation of the adhesive strength between the insulating films, the evaluation of the adhesive strength between the insulating film and the copper foil, and the evaluation of the appearance were each evaluated in the same manner as in Experimental Example 1A.

[0235]

[0236] As shown in Table 4 above, except that the copper foil was changed to a resin-bonded copper foil, it was found that by applying a belt press to the roll-to-roll process as in Example 1B and precisely controlling the belt press process conditions within a predetermined range, a flexible metal laminate having excellent adhesive strength, heat resistance, and appearance characteristics could be manufactured.

[0237] Meanwhile, Example 2B 17 can be used as a control group when comparing the properties of a flexible metal laminate according to the degree of curing of the epoxy adhesive layer after passing through a heating belt.

[0238]

[0239] [Example 3A: 1-9]

[0240] A roll-type flexible metal laminate having a thick-film insulating layer according to Example 3A 1 to 9 was manufactured in the same manner as in Example 1A 1 to 9, except that two roll-type resin-bonded copper foils [copper thickness: 12 ㎛, roughness (Rz): 2.5 ㎛ or less] were used instead of two roll-type copper foils and three polyimide films were not included. At this time, a plurality of resin layers including a polyimide layer (thickness: 20 ㎛) and a thermoplastic polyimide layer (thickness: 5 ㎛) were formed on one surface of the resin-bonded copper foil (RCC). The thicknesses of the thick-film insulating layers included in the flexible metal laminates manufactured in Example 3A 1 to 9 were each 50 ㎛. The specific conditions of the belt press performed in this example were controlled as shown in Table 5 below.

[0241]

[0242] [Comparative Example 3A: 1~2]

[0243] A flexible metal laminate according to Comparative Example 3A 1-2 was manufactured in the same manner as in Example 3A 1 and 3, except that the thermoplastic polyimide adhesive layer was not included, as shown in Table 5 below.

[0244]

[0245] [Experimental Example 3A]

[0246] The properties of the flexible copper-clad laminates manufactured in Examples 1 to 9 of Example 3A and Comparative Example 1 to 2 of Comparative Example 3A were measured according to the following measurement method, and the results are shown in Table 5 below.

[0247] At this time, the adhesion evaluation and appearance evaluation between the resin layer and the copper foil were evaluated in the same manner as in Experimental Example 1A.

[0248]

[0249] As shown in Table 5 above, it was found that, when a belt press is applied to the roll-to-roll process as in Example 1A and the belt press process conditions are precisely controlled within a predetermined range, a flexible metal laminate having excellent adhesive strength, heat resistance, and appearance characteristics can be manufactured, except that the copper foil is changed to a resin-bonded copper foil without using an insulating film.

[0250]

[0251] [Example 3B: 10-16]

[0252] A roll-type flexible metal laminate having a thick-film insulating layer according to Example 3B 10-16 was manufactured in the same manner as in Example 1B 10-17, except that two roll-type resin-bonded copper foils (RCC) [copper thickness: 12 ㎛, roughness (Rz): 2.5 ㎛ or less] were used instead of two roll-type copper foils and three polyimide films were not included. At this time, a plurality of resin layers including a polyimide layer (thickness: 20 ㎛) and an epoxy resin-based adhesive layer (thickness: 5 ㎛) were formed on one surface of the resin-bonded copper foil (RCC). The thicknesses of the thick-film insulating layers included in the flexible metal laminate manufactured in Example 3B 10-16 were each 50 ㎛. The specific conditions of the belt press performed in this example were controlled as shown in Table 6 below.

[0253]

[0254] [Comparative Example 3B: 3~4]

[0255] A flexible metal laminate according to Comparative Example 3B 3-4 was manufactured in the same manner as Example 3B 10-11, except that the epoxy resin adhesive layer was not included, as shown in Table 6 below.

[0256]

[0257] [Experimental Example 3B]

[0258] The characteristics of the flexible copper-clad laminates manufactured in Examples 10 to 17 of Example 3B and Examples 3 to 4 of Comparative Example 3B were measured according to the following measurement method, and the results are shown in Table 6 below.

[0259] At this time, the adhesion evaluation and appearance evaluation between the resin layer and the copper foil were evaluated in the same manner as in Experimental Example 1A.

[0260]

[0261] As shown in Table 6 above, it was found that, when a belt press was applied to the roll-to-roll process as in Example 1B, except that the copper foil was changed to a resin-bonded copper foil without using an insulating film, and the belt press process conditions were precisely controlled within a predetermined range, a flexible metal laminate having excellent adhesive strength, heat resistance, and appearance characteristics could be manufactured.

[0262] Meanwhile, Example 3B 17 can be used as a control group when comparing the physical properties of a flexible metal laminate according to the degree of curing after passing through a heating belt of an epoxy resin-based adhesive layer used as one of multiple resin layers in a resin-attached copper foil.

Claims

A method for manufacturing a flexible metal laminate including a thick film type insulating layer having a thickness of 1.50 ㎛ or more, (i) a step of preparing at least one roll-type metal foil; (ii) a step of preparing a plurality of roll-type insulating films; and (iii) a step of pressing and bonding the metal foil and the insulating film, which are continuously supplied in a roll-to-roll manner, by passing them through a belt press; A method for manufacturing a flexible metal laminate, wherein at least one of the metal foil and the insulating film includes an adhesive layer formed on one or both sides.

2. In paragraph 1, A manufacturing method wherein the above metal foil is copper foil or resin-coated copper foil (RCC).

3. In paragraph 1, The above step (i) prepares at least two metal foils, A manufacturing method, wherein the at least two metal foils have the same thickness and surface roughness.

4. In paragraph 1, A manufacturing method wherein the roughness (Rz) of the above metal foil is 0.5 to 3 ㎛ and the thickness is 1 to 50 ㎛.

5. In paragraph 3, A manufacturing method, wherein, when there are at least two of the above metal foils, in step (ii), a plurality of insulating films are placed between the above metal foils.

6. In paragraph 2, A manufacturing method, wherein the surface of the resin layer formed on the resin-attached copper foil or the surface of the insulating film is plasma-treated.

7. In paragraph 1, The above adhesive layer, One side of the metal foil in contact with the above insulating film, or One side of the insulating film in contact with the above metal foil, or A manufacturing method wherein a plurality of insulating films are formed on one or both sides of the insulating films that are in contact with each other.

8. In paragraph 1, A manufacturing method, wherein the adhesive layer is at least one selected from the group consisting of a thermoplastic polyimide-based adhesive and an epoxy resin-based adhesive.

9. In paragraph 1, In the above step (ii), the thickness of a single insulating film among the plurality of insulating films is 50 ㎛ or less, A manufacturing method wherein the thickness of the thick-film insulating layer in which the above-mentioned plurality of insulating films are integrated is 50 to 200 ㎛.

10. In paragraph 1, The belt press of the above step (iii) An upper belt having multiple rollers; A lower belt having multiple rollers; A heating device that applies heat, pressure, or both to an object passing between the upper belt and the lower belt; and A cooling device capable of cooling an object passing between the upper belt and the lower belt; A manufacturing method comprising:

11. In paragraph 1, A manufacturing method wherein the belt press of the above step (iii) is a hydraulic belt press or a roll-type belt press.

12. In paragraph 8, A manufacturing method wherein the curing temperature of the above epoxy resin adhesive is equal to or lower than the belt temperature applied to the belt press.

13. In paragraph 12, Before passing through the above belt press, the epoxy resin adhesive layer is in a semi-cured state with a degree of curing of 50% or less. A manufacturing method wherein, after passing through the above belt press, the epoxy resin adhesive layer is in a completely cured state with a degree of curing of 70% or more.

14. In paragraph 8, A manufacturing method wherein, when the adhesive layer is an epoxy resin adhesive, step (iii) is pressed under the conditions of a belt temperature of 180 to 380°C, a pressure of 10 to 80 bar, and a conveying speed of 1 to 8 m / min.

15. In paragraph 8, In the case where the above adhesive layer is a thermoplastic polyimide-based adhesive, the manufacturing method wherein step (iii) is pressed under the conditions of a belt temperature of 300 to 380°C, a pressure of 10 to 80 bar, and a conveying speed of 1 to 8 m / min 16. In paragraph 1, A manufacturing method for forming a roll-type flexible metal laminate including a thick film single insulating layer by a continuous process comprising steps (i) to (iii) above.

17. In paragraph 16, The above flexible metal laminate, The interfacial adhesion between multiple insulating films is 0.8 kgf / cm or more, A manufacturing method wherein the adhesive strength between the metal foil and the insulating film is 0.5 to 1.5 kgf / cm. A method for manufacturing a continuous flexible metal laminate including a thick film type insulating layer having a thickness of 18.50 ㎛ or more, (a) a step of preparing two roll-type resin-attached metal foils, and arranging them so that the resin layer-forming surfaces of the resin-attached metal foils face each other; and (b) a step of pressing and bonding two resin-attached metal foils continuously supplied in a roll-to-roll manner by passing them through a belt press; A method for manufacturing a metal laminate, comprising:

19. In paragraph 18, A manufacturing method, wherein the resin layer of the resin-attached metal foil comprises at least two resin layers.

20. In paragraph 18, The thickness of the resin layer included in the above resin-attached copper foil is 50 ㎛ or less, A manufacturing method, wherein the total thickness of the insulating layer in which at least two opposing resin layers are integrated is 50 to 200 ㎛.

Images