CN116333607A

CN116333607A - Ultrathin metal composite film and preparation method and application thereof

Info

Publication number: CN116333607A
Application number: CN202310325667.8A
Authority: CN
Inventors: 胡仲义
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2023-06-27

Abstract

The invention provides an ultrathin metal composite film, a preparation method and application thereof, wherein the preparation method directly prepares a strippable metal thin layer with target thickness through vacuum coating on a transfer layer, and then strips the strippable metal thin layer by using an adhesive and composites the strippable metal thin layer with a polymer thin layer to form the ultrathin metal composite film; or preparing a metal sensitization layer on the polymer film layer, and increasing the thickness through chemical plating and electrolytic plating to obtain a metal thin layer with target thickness, thereby forming an ultrathin metal composite film; the preparation method can avoid the problems of scratch, breakdown or belt breakage of the metal thin layer and the polymer thin layer in the preparation process of vacuum coating, greatly improves the quality of products, can meet the continuous mass production requirement of production line reel to reel, has good uniformity of the metal thin layer in the obtained products, can greatly improve the corrosion resistance of the products through corrosion resistance treatment, and is suitable for being used in corrosive environments.

Description

Ultrathin metal composite film and preparation method and application thereof

Technical Field

The invention belongs to the field of composite materials, and relates to an ultrathin metal composite film, and a preparation method and application thereof.

Background

The ultrathin metal composite film is an ultrathin multilayer composite film compounded by an ultrathin polymer film and a metal thin layer, and is widely applied to industries such as food packaging, electromagnetic shielding, energy storage, consumer electronics and the like as a substitute and a competitive product of a traditional pure metal film.

The traditional pure metal film has only a single metal layer, and with the reduction of the thickness, physical limits exist on the performance, and the obvious reduction of the tensile force, tensile fracture strength and shearing resistance can influence the related manufacturing or processing process, for example, the thickness of the commercialized traditional aluminum foil is 4.5-12 mu m, and only 8-12 mu m thickness can be applied in the electronic industry so as to ensure the stability of the coating and coil butt joint process and prevent the metal film from breaking; when the thickness of the conventional metal film is below 2 μm, there is no tensile break strength nor tensile force, and at this time, the conventional pure metal film cannot be used alone as a foil, so that the ultra-thin metal composite film has an important meaning, which provides sufficient mechanical strength by compounding the polymer film, while contributing to weight saving.

In order to meet the requirements, the ultrathin metal composite films are gradually developed towards lighter and thinner directions, but similar to the traditional pure metal films, the tensile strength and the shearing strength of the metal layers and the polymer films are drastically reduced along with the reduction of the thickness, and the ultrathin metal composite films are difficult to adapt to the subsequent processing technologies such as the current industrialized roll-to-roll technology, so that the mass and high-quality production of the ultrathin metal composite films is limited.

At present, the existing preparation process of the ultrathin metal composite film is to prepare a metal thin layer by using chemical vapor deposition or vacuum coating processes such as physical vapor deposition, magnetron sputtering and the like on two sides of a 2-6 mu m polymeric film material, but the metal coating process directly carried out on the ultrathin polymeric material has serious mass production process problems and use problems, and the main problems are as follows:

(1) The metal coating is to plate the metal material onto the polymer film material with the thickness of 2-8 mu m under the condition of high temperature and high vacuum. Under the condition of high temperature and high vacuum, the tensile fracture strength, the shearing strength and the heat-resistant fracture performance of the polymer film are seriously reduced. Therefore, it is difficult for the common polymeric materials in such high temperature and high vacuum environments to meet the requirements of the use, although the polymeric materials commonly used in the prior art, such as PET, PEN, PI, aramid, polythioether ketone, etc., can hardly meet the requirements of the laboratory process. However, when industrial production is to be carried out, only heat can be dissipated in a heat dissipation mode of heat radiation under the vacuum coating condition, the heat dissipation mode is slow, the efficiency is low, a large amount of accumulated heat is caused by long-time coating, and the polymer film is extremely easy to break due to the condition that the polymer film cannot bear high temperature and high vacuum and is in tension, so that the production efficiency and the production scale are seriously affected.

(2) The thickness of the metal coating with the thickness of 0.5-2 mu m is prepared by coating, and the metal film with the thickness can reach the corresponding thickness after repeated coating for many times during industrial production. If the polymer film is thinner, the film plating speed needs to be reduced more slowly, the film plating time is prolonged, the metal particles are mutually contacted and aggregated in a high-vacuum chamber for a long time to form large metal particles, the large particles fly onto the metal thin layer being coated under the action of an electric field and a magnetic field of the film plating, the problems of damaging the polymer film, perforating, puncturing, breaking, and the like of the polymer film are easily caused, holes or belt breakage of the polymer film are seriously caused, and the fact that the prior art for directly carrying out high-temperature metal plating on the polymer film to prepare the ultrathin metal composite film has poor feasibility in realizing large-scale and rapid mass production is seen.

(3) With the expansion of application fields and the more complex and severe application environments, the ultrathin metal composite film needs to be contacted with a high-temperature and corrosive solution environment when being applied specifically. For example, when the ultrathin metal composite film is in an organic ester solvent and the temperature is 85 ℃, the solution system contains trace amounts of HF acid and inorganic salt components, and the whole process has the repeated electron migration, so that the problems that a metal thin layer is easily subjected to electrochemical oxidation, is easily coordinated with HF acid, and is corroded and dissolved are caused. Therefore, the ultra-thin metal composite film needs to be effectively corrosion-resistant, and particularly needs to be passivated between the metal layer and the polymer film material, otherwise, the requirement of long-term safe use in application cannot be met. In the prior art, nickel and chromium are sputtered on two sides of a polymer film to prime, and then a thick metal layer is plated, but the metal nickel and the metal chromium cannot stably and effectively protect the interface between the metal thin layer and the polymer film in corrosive solution for a long time, so that the metal thin layer and the polymer film fall off; particularly, when electrons in the electrochemical process migrate in and out cyclically in a certain period, the interface between the metallic nickel and chromium-protected polymer film and the metallic thin layer is extremely easily damaged, and the product is rendered nonfunctional.

Therefore, a new method for ultra-thin metal composite films has been developed, which enables the mass production of ultra-thin metal composite films of high quality and corrosion resistance.

Disclosure of Invention

In view of the problems existing in the prior art, the invention aims to provide an ultrathin metal composite film, and a preparation method and application thereof. Essentially thinking and solving the above problems are four ways: (1) How to industrially prepare a stable and reliable metal thin layer in mass production; (2) How the metal thin layer and the polymer thin layer are compounded into an ultrathin metal composite film; (3) corrosion protection of the thin metal layer; (4) Aiming at the severe use scene of the product, the surface of the ultrathin metal composite film is protected. This four points will be discussed in detail below.

(1) Preparation of a Metal lamina

The thin metal layer may comprise any one or a combination of at least two of copper, nickel, palladium, aluminum, zinc, titanium, silver, or iron, and typical but non-limiting examples of the combination include copper-nickel combination, copper-palladium combination, copper-aluminum combination, copper-zinc combination, copper-silver combination, copper-titanium combination, nickel-palladium combination, nickel-aluminum combination, nickel-zinc combination, nickel-titanium combination, nickel-silver combination, nickel-iron combination, palladium-aluminum combination, palladium-zinc combination, palladium-titanium combination, palladium-silver combination, palladium-iron combination, aluminum-zinc combination, aluminum-titanium combination, aluminum-silver combination, aluminum-iron combination, zinc-titanium combination, zinc-silver combination, or titanium-silver combination.

Preferably, the thickness of the metal thin layer is 0.5 to 2 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm or 2 μm, etc., but not limited to the listed values, and other non-listed values within the above-mentioned numerical ranges are equally applicable.

Preferably, the sheet resistance of the metal thin layer is 4-45 mΩ/mm ² For example 4mΩ/mm ² 、7mΩ/mm ² 、10mΩ/mm ² 、15mΩ/mm ² 、20mΩ/mm ² 、25mΩ/mm ² 、30mΩ/mm ² 、35mΩ/mm ² 、40mΩ/mm ² 、42mΩ/mm ² Or 45mΩ/mm ² And the like, but are not limited to the recited values, other non-recited values within the above rangesThe values apply equally well.

When the same metal forms a metal thin layer, parabolic corresponding relations exist between the thickness of the metal layer and the sheet resistance of the metal, and when different metals form the metal thin layer, parabolic curves of the thickness and the sheet resistance are not completely overlapped and slightly different. But in general, when the thickness of the metal thin layer is more than 2. Mu.m, fang Zuxiao is 4mΩ/mm ² The thin metal layer has poor puncture resistance, is not easy to break and short by needling, is not high in safety and is easy to cause short-circuit fire, so that the thickness of the thin metal layer is preferably not more than 2 mu m. When the thickness of the metal thin layer is smaller than 0.5 mu m, the sheet resistance is larger than 45mΩ/mm ² The conduction of the metal thin layer is easy to cause, the multiplying power performance of current is influenced, the internal resistance of the metal thin layer which is too thin is larger, the electronic product is easy to generate heat when running, the energy consumption is increased, and the fire disaster is easily caused when the temperature is too high and overheat is easy to cause. Therefore, after comprehensive analysis of various aspects such as sheet resistance, thickness, weight, current multiplying power and the like, it is considered that the thickness of the metal thin layer is reasonably controlled within the range of 0.5-2 μm, and mass production feasibility and use safety are not provided beyond the range.

The method for preparing the metal thin layer comprises the following steps:

a strippable metal thin layer formed on the transfer layer by vacuum coating;

(II) or on the basis of the formation of a strippable metal sensitization layer by a vacuum coating method, further carrying out chemical growth and/or chemical plating and/or electroplating (electrolytic plating) to obtain a metal thin layer.

Preferably, the vacuum coating method comprises any one or a combination of at least two of vacuum evaporation, vacuum sputtering or ion plating, and typical but non-limiting examples of the combination include a combination of vacuum evaporation and vacuum sputtering, a combination of vacuum evaporation and ion plating or a combination of vacuum sputtering and ion plating.

Wherein, (I) the method for forming the strippable metal thin layer on the transfer layer by using the vacuum coating method is characterized in that:

use of thicker organic or inorganic non-metallic or metallic substrate materials as transfer layer (thickness > 10 μm, this large thickness substrate may not take into account the problem of vacuum heat accumulation); further, these substrates are coated with a release agent or wax, or have the property of being non-tacky to themselves (e.g., titanium and copper are non-tacky to each other, and the use of a titanium substrate can provide the copper metal layer with peelability) to ensure that the metal layer produced by vacuum evaporation, vacuum sputtering, ion plating, or the like can be peeled from the transfer layer.

Because the transfer layer is thicker, the transfer layer can resist high vacuum, high temperature and pulling force under the conditions, and the metal thin layer of the plating film can be rapidly, stably and continuously plated with the metal thin layer required by the invention. The release agent or wax is applied to allow the metal sheet to be easily peeled off by the adhesive. Thereby avoiding the technological mass production problems (such as high temperature, high vacuum, basic stretching and the like) of directly preparing the metal thin layer on the ultrathin polymer thin film layer.

In summary, the method of directly preparing a thin strippable metal layer of a target thickness using a transfer layer of the present invention is one of the key points of the present invention.

It should be emphasized again that the transfer layer is introduced to realize the preparation of the metal thin layer and the compounding of the polymer thin layer, on one hand, compared with the transfer layer, the polymer thin layer can be used in a preparation environment of high temperature and high vacuum tensile force, so that the coating speed of the metal thin layer is increased, and further, when the polymer thin layer is directly used as a substrate (hereinafter referred to as a direct coating process), the problems of product appearance defects, even broken bands and the like, caused by the damage and breakdown of the metal thin layer and/or the polymer thin layer due to the high temperature accumulated by heat and repeated coating process for a long time are avoided, and the product quality and continuous mass production are greatly improved. The transfer layer is introduced on the other hand, and the metal thin layer can be effectively peeled off after the composite process, so that a target product with good appearance is formed by the metal thin layer and the polymer thin film layer, and the problem of poor mass productivity caused by a direct coating process is avoided.

As a preferred embodiment of the present invention, the method for preparing the thin metal layer includes directly preparing the thin metal layer having a thickness of 0.5 to 2 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm, etc., on a transfer layer, which is a substrate having a thickness of 10 to 75 μm or a metal substrate not adhering to the thin metal layer, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, etc., using a vacuum plating method, but the above-mentioned method is not limited to the above-mentioned numerical values, and other numerical values are not equally applicable.

Preferably, the surface of the transfer layer, which is in contact with the metal thin layer, is provided with a wax layer or a release agent coating.

Preferably, the transfer layer comprises any one or a combination of at least two of polybutylene terephthalate (PEN), polyimide (PI), polybenzimidazole, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), titanium foil, or stainless steel foil, typical but non-limiting examples of which include a combination of PEN and PI, a combination of PEN and polybenzimidazole, a combination of PEN and PBT, a combination of PEN and PET, a combination of PEN and titanium foil, a combination of titanium foil and stainless steel foil, or titanium foil.

The method for forming the strippable metal sensitization layer by vacuum coating method and further preparing the metal thin layer by chemical growth and/or chemical plating and/or electrolytic plating growth comprises the following steps:

it is generally known in the art that nickel, palladium, copper in the metallic atomic state obtained by vacuum plating methods such as magnetron sputtering are not electroless plating active, but the present invention has found that controlling the sputtering thickness of nickel, palladium, copper or silver to be 2-500 nm, the metal layer has chemical reactivity, can be made to be a metal sensitization layer of electroless plating, and on this basis, a thicker metal layer is continuously prepared by electroless plating, or on the basis of electroless plating, a thicker metal layer is further reduced by combining the electrolytic plating method.

Therefore, since the metal sensitization layer is very thin, the process can allow the pure metal sensitization layer to be prepared directly on the ultrathin polymer film layer, then the metal thin layer to be grown in an electroless plating mode, or the metal thin layer to be further thickened by an electrolytic plating method on the basis.

The method can avoid the problems of high-temperature damage, belt breakage, appearance defects and the like of the polymer film layer and the metal thin layer caused by heat accumulation due to direct sputtering of the metal thin layer with the large thickness of 0.5-2 mu m on the ultrathin polymer film layer. The method can also effectively avoid the problems of poor appearance of the metal thin layer caused by agglomeration of metal particles due to heat management or multiple coating.

Further, the electroless plating or the electrolytic plating can be further carried out on the basis of the metal sensitization layer, and the electrolytic plating can plate metals such as nickel, copper, palladium, tin, silver, cobalt and the like which are the same as or different from the electroless plating, so that the total thickness of the metal thin layer is finally 0.5-2 mu m, and the range of the products which can be prepared is widened.

It should be further explained that the metal in the metal sensitization layer prepared by the vacuum plating method is in a metal atom state, not in the ion states of ion palladium and colloid palladium of the traditional electroless plating. Electroless plating (chemical plating), also known as metalizing student's growth process or electroless plating (Electroless plating) or autocatalytic plating (Autocatalytic plating), is a plating process in which metal ions in a plating solution are reduced to metal by a suitable reducing agent without an applied current and deposited onto the surface of a metal or polymeric material. The reaction occurs at the interface between the plating solution and the material (substrate) to be plated, the electroless plating temperature is not high, and heat is easily transferred to the plating solution. However, when a nonmetallic material is used as a substrate, such as a polymer film layer, the substrate is subjected to pickling pits and sensitization treatment to form a reducing liquid film (sensitization layer) with a reducing effect on the surface of the substrate. The good sensitization effect requires that the ions with the reduction function in the sensitization layer can maintain the reduction capability for a long time under certain conditions and can control the speed of the reduction reaction, and the key point is that the products to be reduced by sensitization are controlled not to be continuous plating layers but to be activation points. Therefore, for the sensitization of the traditional electroless plating when a nonmetallic material is used as a substrate, the substrate is treated in a sensitizer so as to obtain ions with reducibility on the surface of the film, thereby the electroless plating can be carried out, In practical applications, the sensitization layer on the surface of the polymer film layer is often colloidal palladium or ionic palladium, and in general, palladium needs to be in an ionic state and in a metal atom state. Compared with the mechanism, the invention utilizes sputtering to obtain a metal thin layer with specific thickness, so that the metal thin layer is used as a sensitization layer, and the principle of the metal thin layer is different from that of the traditional chemical plating. The traditional sensitization chemical plating method has low speed, difficult control of sensitization effect and short sensitization service life, particularly the plating uniformity and sheet resistance uniformity under the conditions of large width and long size are difficult to reach the standard, and more noble metal waste liquid is generated to pollute the environment; when the method of the invention is used for taking the polymer film layer as a substrate, sensitization treatment such as a sensitizer and the like can be avoided, the preparation requirement is greatly reduced, the sensitizer is not used, the cost is saved, the influence on the electroless plating activity after sensitization is not required to be considered, the production speed is higher, the obtained metal film layer is more uniform, and the sheet resistance uniformity is less than +/-10 mΩ/mm ² 。

Further, electrolytic copper plating is a technique of plating a thin layer of other metal or alloy on the surface of some conductive metals by the principle of electrolysis. Has the characteristics of low cost, wide metal selection range and the like. In view of the mass production range and cost, when the thickness of the chemical metal coating is gradually increased, the initial conductivity of the metal layer, namely the surface resistance, is gradually reduced to be lower than 100mΩ, the invention can further thicken the metal coating by using the traditional electrolytic plating method, and the electrolytic plated metal can be the same as or different from the chemical plated metal, thereby widening the application field of products.

It can be seen that the technical principle and process flow of the process adopted by the invention are different from those of the traditional electroless plating method. At present, no data exists on electroless plating activity of a metal sensitization layer prepared by utilizing metal atoms. The production efficiency of the extremely thin metal sensitization layer (more preferably 10-30 nm) prepared by the vacuum plating method is much faster than that of the traditional chemical plating base film sensitization liquid from the aspect of mass production, and the base film sensitization layer does not need to be dried more uniformly. Therefore, the method can bring remarkable improvement to the industrial production efficiency.

In summary, the method of preparing a metal thin layer using a metal sensitization layer having electroless plating activity of 10-30 nm is another core invention point of the present invention.

As a preferable technical scheme of the invention, when preparing any one or at least two metal thin layers of copper, nickel or cobalt, firstly preparing an alloy formed by any one or at least two of nickel, palladium, copper or silver with the thickness of 2-500 mg/m on a base material or the polymer thin film layer by utilizing a vacuum plating method, for example, 10nm, 12nm, 14nm, 16nm, 18nm, 20nm, 22nm, 24nm, 26nm, 28nm or 30nm and the like ² For example 2mg/m ² 、5mg/m ² 、10mg/m ² 、25mg/m ² 、50mg/m ² 、75mg/m ² 、100mg/m ² 、150mg/m ² 、200mg/m ² 、250mg/m ² 、300mg/m ² 、350mg/m ² 、400mg/m ² 、450mg/m ² Or 500mg/m ² And then forming an electroless plating layer by using electroless plating to prepare an alloy formed of any one or at least two of nickel, copper, palladium, tin, silver, and cobalt on the metal sensitization layer, wherein the metal sensitization layer and the electroless plating layer constitute the metal thin layer such that the thickness of the metal thin layer is 0.03 to 2 μm, for example, 0.03 μm, 0.05 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm, etc., but the present invention is not limited to the above-mentioned values, and other values not listed in the above range are equally applicable.

In a preferred embodiment of the present invention, when the thickness of the electroless plating layer is increased to gradually decrease the resistance to 100mΩ or less during the electroless plating, for example, 99mΩ, 90mΩ, 80mΩ, 70mΩ, 60mΩ, 50mΩ, 40mΩ, 30mΩ, 20mΩ, or 10mΩ, an alloy of any one or at least two of nickel, copper, palladium, tin, silver, or cobalt is prepared on the electroless plating layer by electroplating, and the metal sensitization layer, the electroless plating layer, and the plating layer together form the metal thin layer, so that the thickness of the metal thin layer is 0.5 to 2 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, or the like, but the metal thin layer is not limited to the other values not specifically mentioned.

(2) Preparation of ultrathin metal composite film

As a preferable technical scheme of the invention, the functional layer of the ultrathin metal composite film at least comprises a polymer film layer and a metal thin layer.

Preferably, in the ultrathin metal composite film, the metal thin layer is arranged on two sides or one single side of the polymer thin film layer.

Preferably, the material of the polymer film layer includes any one or at least two of polyethylene terephthalate (PET), polybutylene terephthalate (PEN), cellulose, polyethylene (PE), polypropylene (PP), polyamide, polyimide (PI), polyvinyl chloride, polystyrene, polybenzimidazole, polyaramid, polyurea, or polybenzimidazole, and the typical but non-limiting examples of the combination include a combination of PET and PEN, a combination of PET and PI, a combination of PET and PP, a combination of PET and PE, a combination of PEN and PI, a combination of PEN and PP, a combination of PEN and PE, a combination of PI and PP, a combination of PI and PE, a combination of PP and PE, and the like.

Preferably, the thickness of the polymer film layer is 2 to 6 μm, for example, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm or 6 μm, etc., but not limited to the recited values, and other non-recited values within the above-mentioned numerical ranges are equally applicable.

Preferably, an adhesion modifying material is added to the polymer film layer.

Preferably, the adhesion modifying material comprises any one or a combination of at least two of maleic acid modified polypropylene, coupling agent or vinyl chloride resin, and typical but non-limiting examples of such combinations include combination of maleic acid modified polypropylene and coupling agent, combination of maleic acid modified polypropylene and vinyl chloride resin or combination of coupling agent and vinyl chloride resin, and other adhesion modifying materials capable of improving adhesion of the polymer film layer may be selected as desired.

Preferably, the polymer film layer is a single continuous film or a porous film.

Preferably, a reinforcing material is further added to the polymer film layer to enhance the tensile breaking strength of the polymer film layer.

Preferably, the reinforcing material comprises any one or a combination of at least two of carbon fibers, glass fibers, cellulose fibers, polyurea fibers, polyaramid fibers, or PI fibers, typical but non-limiting examples of which include carbon fibers in combination with glass fibers, carbon fibers in combination with cellulose fibers, carbon fibers in combination with polyurea fibers, carbon fibers in combination with polyaramid fibers, carbon fibers in combination with PI fibers, glass fibers in combination with cellulose fibers, polyurea fibers in combination with polyaramid fibers, PI fibers in combination with glass fibers, or PI fibers in combination with cellulose fibers.

The method for preparing the ultrathin metal composite film by processing the functional layers together can be based on the method for preparing the metal thin layer, wherein the preparation method specifically comprises any one or a combination of at least two of a bonding method, a chemical student growth method and a physical student growth method, and typical but non-limiting examples of the combination comprise a combination of the bonding method and the chemical student growth method or a combination of the bonding method and the physical student growth method.

Preferably, the ultrathin metal composite film is prepared by peeling the metal thin layer from the transfer layer by using an adhesive and attaching the metal thin layer and the polymer thin film layer together.

Preferably, the chemical growth method comprises, when preparing an ultrathin metal composite film of any one or at least two of copper, nickel or cobalt, preparing an alloy formed by any one or at least two of nickel, palladium, copper or silver with a thickness of 2-500 mg/m on a polymer film layer by a vacuum plating method ² Then preparing an alloy formed by any one or at least two of nickel, copper, palladium, tin, silver or cobalt on the metal atomic layer by using chemical plating to form a chemical plating layer, wherein the metal sensitization layer and the chemical plating layer form And the thickness of the metal thin layer is 0.03-2 mu m, so that the ultrathin metal composite film is obtained.

Preferably, the physicochemical growth method comprises preparing an alloy formed by any one or at least two of nickel, copper, palladium, tin, silver or cobalt on the chemical plating layer by using an electroplating method to form an electroplated layer when the thickness of the chemical plating layer is increased to gradually reduce the resistance to below 100mΩ on the basis of the chemical plating method, wherein the metal sensitization layer, the chemical plating layer and the electroplated layer jointly form the metal thin layer, and the thickness of the metal thin layer is 0.5-2 μm, so that the ultrathin metal composite film is obtained.

Preferably, the total thickness of the ultrathin metal composite film is 4 to 10 μm, for example, 4 μm, 4.2 μm, 4.4 μm, 4.6 μm, 4.8 μm, 5 μm, 5.2 μm, 5.4 μm, 5.6 μm, 5.8 μm, 6 μm, 6.2 μm, 6.4 μm, 6.6 μm, 6.8 μm, 7 μm, 7.2 μm, 7.4 μm, 7.6 μm, 7.8 μm, 8.2 μm, 8.4 μm, 8.6 μm, 8.8 μm, 9 μm, 9.2 μm, 9.4 μm, 9.6 μm, 9.8 μm or 10 μm, etc., but is not limited to the values recited above, and other values not recited in the above numerical ranges are equally applicable.

Preferably, in the bonding method, the adhesive is any one of a maleic anhydride modified polypropylene adhesive, a carboxylic acid modified polyolefin adhesive, a hydroxyl modified polyolefin adhesive or special modified polyester; the adhesive has corrosion resistance and has adhesion and stability which can be used for a long time under the environment condition of electron migration.

Preferably, the temperature of the adhesive is 80 to 120 ℃, for example 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃ or the like, but is not limited to the recited values, and other non-recited values within the above-recited value range are equally applicable.

Preferably, the bonding temperature is 80 to 120 ℃, such as 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃ or the like, the pressure is 0.2 to 0.4MPa, such as 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, 0.4MPa or the like, the speed is 10 to 200m/min, such as 10m/min, 20m/min, 50m/min, 70m/min, 90m/min, 110m/min, 130m/min, 150m/min, 170m/min, 200m/min or the like, but the bonding temperature is not limited to the recited values, and other non-recited values within the above-recited numerical ranges are equally applicable.

Preferably, the glue is dried to form an adhesive layer having a thickness of 0.2 to 2 μm, for example, but not limited to the listed values, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm or 2 μm, etc., and other non-listed values within the above-mentioned range are equally applicable.

Through strict screening, the invention discovers that the maleic anhydride modified polypropylene adhesive, the carboxylic acid modified polyolefin adhesive, the hydroxyl modified polyolefin adhesive or the special modified polyester can be applied, but the conventional polyacrylate, polyurethane, epoxy and organosilicon glue can not meet the use requirement of long-term stable adhesion in an ester solvent, a solution containing electrolyte and 1000ppm of water at the temperature of 85 ℃. It should be emphasized that, in response to the demand of thinning the electronic product, the thickness of the adhesive layer is preferably not more than 2 μm, and more than 2 μm affects the bulk thickness advantage of the product, while too thin adhesive layer cannot ensure long-term adhesion, and the lower limit of the thickness of the adhesive layer is preferably 0.2 μm after experimental verification.

(3) Corrosion resistant treatment of thin metal layers

The key to the corrosion protection treatment of thin metal layers is to understand the corrosion resistance requirements of potential ultra-thin metal composite films caused by the use environment and to give corresponding solutions.

When the thickness of the metal layer is smaller than 2 mu m, the surface of the metal layer is porous, so that the metal layer can not only influence the appearance requirement, but also be extremely easy to penetrate by a solvent in the use environment of a product to reach the metal protection layer, thereby causing corrosion and damage to the interface between the metal layer and the ultrathin polymer film layer, and the metal layer is required to be subjected to corrosion-resistant treatment according to the use environment requirement of the product. The anti-corrosion treatment is preferably external surface passivation or hole sealing appearance modification treatment, and the two treatment modes can prevent corrosive solution from penetrating, improve the anti-corrosion performance of the product, and the treatment depth does not need to reach the interface between the metal thin layer and the polymer thin layer;

Hydrofluoric acid is a weak acid, but a strong complexing material is prone to form a complexing etch with metal oxides or directly corrode active metals, and does not corrode partially inactive metals, typically copper. Copper oxide is susceptible to corrosion by hydrofluoric acid, but dried and unoxidized copper can withstand corrosion by hydrofluoric acid. The corrosion of hydrofluoric acid can cause the change of the electric conduction and magnetic conduction properties of the metal thin layer, and seriously cause the pulverization, the falling and the dissolution of the metal thin layer. Therefore, considering that electrons migrate in the actual use scene of the product, the nature of the product is the cyclic reciprocation of electrochemical reaction, under the condition, the metal thin layer is more easily subjected to electrochemical oxidation, and the metal thin layer is more easily damaged due to the hydrofluoric acid environment, so that the product cannot be stably used for a long time.

Thus, a corrosion-resistant treatment of the metal thin layer, in particular, a corrosion-resistant treatment for the interface between the metal thin layer and the polymer thin film layer is required.

As a preferable technical scheme of the invention, the ultrathin metal composite film further comprises an anti-corrosion layer arranged on the metal thin layer.

Preferably, the corrosion-resistant layer is disposed on both sides or on one side of the thin metal layer.

Preferably, in the bonding method, a side of the metal thin layer having the corrosion-resistant layer is bonded to the polymer thin film layer.

Preferably, the anti-corrosion layer formed by passivating the outer surface comprises any one of hexavalent chromium passivator, trivalent chromium passivator, zirconium passivator, phosphorus passivator, molybdic acid passivator, chromium-free passivator, hole sealing agent or benzotriazole antioxidant capable of playing an antioxidant role.

Preferably, the corrosion-resistant layer is a trivalent chromium-based passivating agent from the standpoint of environmental protection and personnel safety.

Preferably, the hole sealing appearance modification can be carried out by selecting hole sealing agents, such as aluminum alloy dyeing hole sealing agents for Ningbo traffic, or adopting color passivating agent for treatment, so that the appearance has different colors, and meanwhile, the hole sealing can be effectively carried out to improve the corrosion resistance.

Preferably, the thickness of the anti-corrosion layer is 0 to 100nm, for example 0nm, 1nm, 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm or 100nm, etc., and when 0nm, the product use environment does not need or is not provided with an anti-corrosion layer.

The anti-corrosion layer can play roles in improving color, corrosion resistance, hole sealing, appearance flatness modification and the like, and the extra metal layer formed by the layer can further control sheet resistance, improve the error of the sheet resistance and enable the sheet resistance error of the whole rolled product to be smaller than +/-10 mΩ.

(4) And carrying out appearance and protection treatment on the outer surface of the ultrathin metal composite film.

The ultrathin metal composite film formed by processing the functional layers together can further perform external surface corrosion resistance treatment and appearance improvement.

Preferably, the appearance improvement comprises the treatment steps of passivation treatment, hole sealing treatment of the outer surface of the composite film, resin coating protection, paint spraying, paint coloring, marking and the like for improving the appearance of the product.

The thickness of the finished product of the ultrathin metal composite film obtained by the preparation method is 4-10 mu m, the stretching force of the finished product is more than 6N/25mm, and the surface sheet resistance is 4-45 mΩ/mm ² The finished product can be stably used for a long time at the temperature of minus 40 ℃ to 60 ℃ in an organic solvent containing hydrofluoric acid or hydrofluoric acid and metal salt.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) According to the invention, the metal thin layer with the target thickness can be directly prepared and stripped by vacuum coating on the transfer layer, or the metal sensitized layer with the thinner thickness is prepared, and then the metal thin layer is prepared on the metal sensitized layer through chemical plating and electrolytic plating, so that the problems of high temperature, high vacuum, easy belt breakage, poor appearance and the like caused by direct vacuum coating on the polymer thin film layer are avoided, and meanwhile, compared with the sensitization process of the traditional chemical plating, the production efficiency is greatly accelerated;

(2) The preparation method of the ultrathin metal composite film comprises the steps of peeling the metal thin layer by using an adhesive on the basis of the method for preparing the metal thin layer, compositing the metal thin layer with the polymer thin layer, or directly forming a metal sensitization layer on the polymer thin layer, and then obtaining the metal thin layer with the target thickness through chemical plating and electrolytic plating to form the ultrathin metal composite film, wherein the problems that the metal thin layer and/or the polymer thin layer are damaged by being knocked or broken and even broken belt caused by directly vacuum plating on the polymer thin layer can be avoided by the two methods, so that the product quality is greatly improved and continuous large-scale production is ensured;

(3) Before the metal thin layer is compounded, the metal thin layer is subjected to corrosion resistance treatment, so that the interface between the metal thin layer and the polymer thin film layer can be protected, and the corrosion resistance of the obtained ultrathin metal composite film is greatly improved.

Detailed Description

The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

Example 1

The embodiment provides a preparation method of an ultrathin metal composite film and the ultrathin metal composite film prepared by the preparation method, wherein the preparation method comprises the following steps:

(1) Plating a copper metal thin layer with the thickness of 0.5 mu m on a titanium foil with the thickness of 10 mu m by vacuum sputtering;

(2) Performing first passivation on the copper metal thin layer by using a trivalent chromium passivating agent to form a first passivation layer, wherein the chromium content in the first passivation layer is 30mg/m ² ；

(3) Coating special modified polyester glue on two sides of a PP ultrathin polymer film layer with the thickness of 2 mu m, drying to remove solvent, forming an adhesive layer with the thickness of 0.2 mu m, attaching the adhesive layer on the first passivation layer of the copper metal thin layer obtained in the step (2), carrying out hot-pressing compounding at the temperature of 100 ℃ and the pressure of 0.2MPa, stripping the titanium foil from the copper metal thin layer, and curing to thoroughly solidify the adhesive layer, thereby obtaining the ultrathin metal composite film with the copper metal thin layer on two sides.

Example 2

(1) Plating a copper metal thin layer with the thickness of 1 mu m on a titanium foil with the thickness of 50 mu m by electrolysis;

(2) Performing first passivation on the copper metal thin layer by using a trivalent chromium passivating agent to form a first passivation layer, wherein the chromium content in the first passivation layer is 260mg/m ² ；

(3) Coating maleic anhydride modified polypropylene glue on one side of a PET ultrathin polymer film layer with the thickness of 3.4 mu m, drying to remove solvent, forming an adhesive layer with the thickness of 1 mu m, attaching the adhesive layer on the first passivation layer of the copper metal film obtained in the step (2), carrying out hot-pressing compounding at 90 ℃ and 0.3MPa, stripping the titanium foil from the copper metal film, and curing to thoroughly solidify the adhesive layer, thereby obtaining the ultrathin metal composite film with the copper metal film on one side.

Example 3

(1) Plating a copper metal thin layer with the thickness of 2 mu m on a titanium foil with the thickness of 75 mu m by vacuum sputtering;

(2) Performing first passivation on the copper metal thin layer by using a trivalent chromium passivating agent to form a first passivation layer, wherein the chromium content in the first passivation layer is 500mg/m ² ；

(3) Coating special modified polyester glue on one side of a PE ultrathin polymer film layer with the thickness of 4.5 mu m, drying to remove solvent, forming an adhesive layer with the thickness of 2 mu m, attaching the adhesive layer on the first passivation layer of the copper metal film obtained in the step (2), carrying out hot-pressing compounding at the temperature of 80 ℃ and the pressure of 0.4MPa, peeling titanium foil from the copper metal film, curing to thoroughly cure the adhesive layer, carrying out vacuum sputtering on one side of the copper metal film far away from the polymer film layer to form a copper metal layer with the thickness of 100nm, and carrying out external surface passivation treatment on the copper metal layer by using a trivalent chromium passivation agent to obtain the ultrathin metal composite film with the copper metal film on one side.

Example 4

(1) Plating a thin layer of 1.5 μm thick aluminum metal on a 30 μm thick stainless steel film coated with a silicone release agent by vacuum sputtering;

(2) Performing first passivation on the aluminum metal thin layer by using trivalent chromium passivating agent to form a first passivation layer, wherein the chromium content in the first passivation layer is 120mg/m ² ；

(3) Coating maleic anhydride modified polypropylene glue on one side of a PEN ultrathin polymer film layer with the thickness of 6 mu m, drying to remove solvent, forming an adhesive layer with the thickness of 0.8 mu m, attaching the adhesive layer on the first passivation layer of the aluminum metal film obtained in the step (2), carrying out hot pressing compounding at the temperature of 90 ℃ and the pressure of 0.3MPa, peeling the stainless steel film coated with the organosilicon release agent from the aluminum metal film, curing to thoroughly solidify the adhesive layer, carrying out vacuum sputtering on one side of the aluminum metal film far away from the polymer film layer to form an aluminum metal layer with the thickness of 50nm, and carrying out outer surface passivation treatment on the aluminum metal layer by using a trivalent chromium passivation agent to obtain the ultrathin metal composite film with the aluminum metal film on one side.

Example 5

(1) Coating a thin aluminum metal layer with the thickness of 1.2 mu m on a PET film with the thickness of 70 mu m and coated with an organosilicon release agent by vacuum sputtering;

(2) Performing first passivation on the aluminum metal thin layer by using a trivalent chromium passivating agent to form a first passivation layer, wherein the chromium content in the first passivation layer is 400mg/m ² ；

(3) Coating maleic anhydride modified polypropylene glue on two sides of a PI ultrathin polymer film layer with the thickness of 5 mu m, drying to remove a solvent, forming an adhesive layer with the thickness of 1.4 mu m, attaching the adhesive layer on the first passivation layer of the aluminum metal film obtained in the step (2), carrying out hot pressing compounding at the temperature of 90 ℃ and the pressure of 0.3MPa, peeling the stainless steel film coated with the organosilicon release agent from the aluminum metal film, curing to thoroughly solidify the adhesive layer, carrying out vacuum sputtering on one side of the aluminum metal film far away from the polymer film layer to form an aluminum metal layer with the thickness of 50nm, and carrying out outer surface passivation treatment on the aluminum metal layer by using a trivalent chromium passivation agent to obtain the ultrathin metal composite film with the aluminum metal film on two sides.

Example 6

Plating nickel, palladium and copper alloy (molar ratio is 8:1:1) with the thickness of 3nm on one side of a PP polymer film layer with the thickness of 6 mu m by using vacuum sputtering to form a first metal layer, carrying out electroless copper plating on the first metal layer to form a second metal layer with the thickness of 1.5 mu m, wherein the first metal layer and the second metal layer form a metal thin layer;

performing external surface passivation treatment on the obtained metal thin layer by using trivalent chromium color passivation solution to form a passivation layer, wherein the chromium content in the passivation layer is 6mg/m ² And obtaining the ultrathin metal composite film with the metal thin layer on one side.

Example 7

plating nickel, palladium and copper alloy (molar ratio is 8:1:1) with the thickness of 5nm on one side of a porous PET polymer film layer with the thickness of 4 mu m by vacuum sputtering to form a first metal layer, carrying out electroless copper plating on the first metal layer to form a second metal layer with the thickness of 1.5 mu m, wherein the first metal layer and the second metal layer form a metal thin layer;

external application of the obtained metal thin layer by using trivalent chromium color passivation solutionSurface passivation treatment is carried out to form a passivation layer, wherein the chromium content in the passivation layer is 6mg/m ² And obtaining the ultrathin metal composite film with the metal thin layer on one side.

Example 8

plating nickel, palladium and copper alloy (molar ratio is 8:1:1) with the thickness of 50nm on two sides of a PP polymer film layer with the thickness of 6 mu m by vacuum sputtering to form a first metal layer, carrying out electroless copper plating on the first metal layer to form a second metal layer with the thickness of 1.5 mu m, wherein the first metal layer and the second metal layer on the same side form a metal thin layer;

performing external surface passivation treatment on the obtained metal thin layer by using trivalent chromium color passivation solution to form a passivation layer, wherein the chromium content in the passivation layer is 10mg/m ² And sputtering a 20nm metal nickel layer on the passivation layer to obtain the ultrathin metal composite film with the metal thin layers on two sides.

Example 9

plating nickel, palladium and copper alloy (molar ratio is 8:1:1) with the thickness of 100nm on two sides of a PE polymer film layer with the thickness of 6 mu m by vacuum sputtering to form a first metal layer, carrying out electroless copper plating on the first metal layer to form a second metal layer with the thickness of 1.5 mu m, wherein the first metal layer and the second metal layer on the same side form a metal thin layer;

Sputtering 20nm metal copper layers on the metal thin layers on the two sides, and performing outer surface passivation treatment on the surfaces of the two sides by using trivalent chromium color passivation solution to form a passivation layer, wherein the chromium content in the passivation layer is 10mg/m ² And obtaining the ultrathin metal composite film with the metal thin layers on the two sides.

Comparative example 1

The comparative example provides a preparation method of an ultrathin metal composite film and the ultrathin metal composite film prepared by the preparation method, wherein a nickel-chromium layer is directly plated on a PEN ultrathin polymer film layer with the thickness of 6 mu m by vacuum sputtering, and an aluminum metal thin layer with the thickness of 1.5 mu m is further plated on the nickel-chromium layer, so that the ultrathin metal composite film with the aluminum metal thin layer on one side is obtained.

Comparative example 2

The comparative example provides a preparation method of an ultrathin metal composite film and the ultrathin metal composite film prepared by the preparation method, wherein the preparation method is to carry out ionic palladium solution treatment on a PET ultrathin polymer film layer with the thickness of 3.4 mu m, and then to carry out chemical plating to form a copper metal thin layer with the thickness of 1 mu m, so as to obtain the ultrathin metal composite film with the copper metal thin layer on one side.

Comparative example 3

The comparative example provides a preparation method of an ultrathin metal composite film and the ultrathin metal composite film prepared by the preparation method, wherein the preparation method comprises the following steps:

Plating nickel, palladium and copper alloy (molar ratio is 8:1:1) with the thickness of 5nm on one side of a non-porous PET polymer film layer with the thickness of 4 mu m by vacuum sputtering to form a first metal layer, carrying out electroless copper plating on the first metal layer to form a second metal layer with the thickness of 1.5 mu m, wherein the first metal layer and the second metal layer form a metal thin layer;

and performing antioxidation treatment on the obtained metal thin layer to obtain the ultrathin metal composite film with the metal thin layer on one side.

Comparative example 4

the process was identical to comparative example 4 except that the nonporous PET polymer film layer was replaced with a nonporous PP polymer film layer.

The ultrathin metal composite film obtained in the examples and comparative examples was subjected to the following test:

1. and (3) sheet resistance test: referring to ASTM F390-2011, a sheet resistance test was performed at 25℃using a four-probe test, and the test results are shown in Table 1;

2. electrolyte corrosion resistance test: after immersing the ultrathin metal composite film in electrolyte of a ternary high-nickel battery containing 1000ppm of water at 85 ℃ for 720 hours, testing the resistance after immersion and the peeling force after immersion, wherein the test results are shown in table 1;

TABLE 1

As can be seen from table 1:

the process flow of the preparation method described in the embodiments 1 to 5 is that a metal thin layer is directly prepared on a thick substrate, corrosion resistance is guaranteed through a first passivation treatment, and then a polymer thin film layer is used for stripping a metal coating, so that an ultrathin metal composite film can be obtained. The polymer film layers obtained in the examples 1-5 can pass the long-term electrolyte soaking test, and enough stripping force is reserved, so that the obtained ultrathin metal composite film product has good corrosion resistance and stability;

the process flows of the preparation methods described in examples 6 to 9 are that a first metal layer with chemical reactivity is directly prepared on a polymer film layer, a second metal layer is grown on the first metal layer through chemical plating to form a metal thin layer, and post-treatment is performed on the metal thin layer to obtain an ultrathin metal composite film product; the post-treatment is carried out by adopting a color passivating agent in the examples 6-9, the passivating agent can effectively seal holes on the porous polymer film layer and the metal thin layer in the example 7, a nickel metal layer is added after the post-passivation treatment in the examples 8 and 9 to reduce sheet resistance, the polymer film layers obtained in the examples 6-9 can pass the long-term electrolyte soaking test, and enough stripping force is reserved, so that the obtained ultrathin metal composite film product has good corrosion resistance and stability;

Comparative example 1 using the prior art, a nickel-chromium priming was first sputtered on a polymer film layer, then a thin metal layer was formed, which failed the long term electrolyte soak test; comparative example 2 using the prior art, sensitization was performed on a polymer thin film layer, then electroless plating was performed to form a copper thin metal layer, and after long-term electrolyte immersion, the copper thin metal layer was dissolved by the electrolyte;

compared with the example 7, the PET polymer film layer is used, the comparative example 3 adopts the nonporous PET polymer film layer and does not carry out external surface passivation treatment, only carries out antioxidation treatment, and after long-term electrolyte soaking, the metal thin layer is corroded, shed and pulverized by the electrolyte, so that the stripping force can not be measured, and the product can not pass the electrolyte test; in comparative example 4, the nonporous PET polymer film layer in comparative example 3 is replaced by a nonporous PP polymer film layer, after being soaked by electrolyte for a long time, the metal film can be corroded by the electrolyte to a certain extent, stripping force data can still be measured, and compared with comparative example 3, the electrode solution resistance is better, but the corrosion resistance of the whole product cannot be improved, and therefore, the metal film is easy to corrode under the protection of no passivation treatment, so that the sheet resistance becomes large.

The detailed structural features of the present invention are described in the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope of the present invention and the scope of the disclosure.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims

1. The preparation method of the ultrathin metal composite film is characterized in that the functional layer of the ultrathin metal composite film comprises a polymer film layer and a metal thin layer;

the preparation method of the ultrathin metal composite film for processing the functional layers together comprises any one or a combination of at least two of a bonding method, a chemical student growth method and a physical student growth method.

2. The method of claim 1, wherein the polymer film layer comprises any one or a combination of at least two of polyethylene terephthalate, polybutylene terephthalate, cellulose, polyethylene, polypropylene, polyamide, polyimide, polyvinyl chloride, polystyrene, polybenzimidazole, polyaramid, polyurea, and polybenzimidazole;

preferably, the thickness of the polymer film layer is 2-6 μm;

preferably, an adhesion modifying material is added to the polymer film layer;

preferably, the adhesion modifying material comprises any one or a combination of at least two of maleic acid modified polypropylene, a coupling agent or a vinyl chloride-vinyl acetate copolymer;

preferably, the polymer film layer is a single continuous film or a porous film;

preferably, a reinforcing material is further added into the polymer film layer;

preferably, the reinforcing material comprises any one or a combination of at least two of carbon fibers, glass fibers, cellulose fibers, polyurea fibers, polyaramid fibers or PI fibers.

3. The production method according to claim 1 or 2, wherein the metal component of the metal thin layer comprises any one or a combination of at least two of copper, nickel, palladium, aluminum, zinc, titanium, silver, or iron;

Preferably, the thickness of the metal thin layer is 0.5-2 μm;

preferably, the sheet resistance of the metal thin layer is 4-45 mΩ/mm ² ；

4. A production method according to any one of claims 1 to 3, wherein the method for producing the metal thin layer comprises producing the metal thin layer of 0.5 to 2 μm thickness directly on a transfer layer, which is a substrate of 10 to 75 μm thickness or a metal substrate non-sticking to the metal thin layer, using a vacuum plating method;

preferably, the surface of the transfer layer, which is in contact with the metal thin layer, is provided with a wax layer or a release agent coating;

preferably, the transfer layer comprises any one or a combination of at least two of polybutylene terephthalate, polyimide, polybenzimidazole, polybutylene terephthalate, polyethylene terephthalate, titanium foil, or stainless steel foil;

preferably, when preparing a metal thin layer of any one or at least two of nickel, palladium, copper or silver, an alloy formed of any one or at least two of nickel, palladium, copper or silver with a thickness of 2-500 mg/m is prepared on the transfer layer or the polymer thin film layer by vacuum plating method ² Preparing an alloy formed by any one or at least two of nickel, copper, palladium, tin, silver or cobalt on the metal sensitization layer by using chemical plating to form a chemical plating layer, wherein the metal sensitization layer and the chemical plating layer form a metal thin layer, and the thickness of the metal thin layer is 0.03-2 mu m;

preferably, in the electroless plating process, when the thickness of the electroless plating layer increases to gradually decrease the resistance to 100mΩ or less, an alloy formed of any one or at least two of nickel, copper, palladium, tin, silver, or cobalt is prepared on the electroless plating layer by an electroplating method to form a plating layer, and the metal sensitization layer, the electroless plating layer, and the plating layer together form the metal thin layer such that the thickness of the metal thin layer is 0.5 to 2 μm.

5. The method of claim 4, wherein the lamination process comprises peeling the thin metal layer from the transfer layer using an adhesive and laminating it with the polymer film layer to produce the ultra-thin metal composite film;

preferably, the chemical growth method comprises, when preparing an ultrathin metal composite film of any one or at least two of copper, nickel or cobalt, preparing an alloy formed by any one or at least two of nickel, palladium, copper or silver with a thickness of 2-500 mg/m on a polymer film layer by a vacuum plating method ² Preparing any one or alloy formed by at least two of nickel, copper, palladium, tin, silver or cobalt on the metal sensitization layer by using chemical plating to form a chemical plating layer, wherein the metal sensitization layer and the chemical plating layer form a metal thin layer, and the thickness of the metal thin layer is 0.03-2 mu m to obtain the ultrathin metal composite film;

preferably, the physicochemical growth method comprises, on the basis of the chemical growth method, preparing an alloy formed by any one or at least two of nickel, copper, palladium, tin, silver or cobalt on the chemical plating layer by using an electroplating method when the thickness of the chemical plating layer is increased to gradually reduce the resistance to 100mΩ or less, forming an electroplated layer, wherein the metal sensitization layer, the chemical plating layer and the electroplated layer together form the metal thin layer, and the thickness of the metal thin layer is 0.5-2 μm, thus obtaining the ultrathin metal composite film;

preferably, the vacuum coating method comprises any one or a combination of at least two of vacuum evaporation, vacuum sputtering or ion plating;

preferably, the total thickness of the ultra-thin metal composite film is 4 to 10 μm.

6. The method of any one of claims 1-5, wherein the ultra-thin metal composite film further comprises an anti-corrosion layer disposed on the thin metal layer;

Preferably, the anti-corrosion layer is arranged on two sides or one side of the metal thin layer;

preferably, in the bonding method, a side with the corrosion-resistant layer in the metal thin layer is bonded to the polymer thin film layer;

preferably, the corrosion-resistant layer comprises any one of hexavalent chromium, trivalent chromium, zirconium, phosphorus, molybdic acid or chromium-free passivating agent, or any one of hole sealing agent or benzotriazole antioxidant;

preferably, when the metal component of the metal thin layer is copper, the anti-corrosion layer is a benzotriazole antioxidant or trivalent chromium passivator;

preferably, the corrosion-resistant layer is a trivalent chromium-based passivating agent;

preferably, the thickness of the corrosion-resistant layer is 0-100 nm.

7. The method according to claim 5, wherein in the bonding method, the adhesive is any one of a maleic anhydride modified polypropylene-based adhesive, a carboxylic acid modified polyolefin adhesive, a hydroxyl modified polyolefin adhesive, or a special modified polyester;

preferably, the drying temperature of the adhesive is 80-120 ℃;

preferably, the bonding temperature is 80-120 ℃, the pressure is 0.2-0.4 MPa, and the speed is 10-200 m/min;

Preferably, the thickness of the formed adhesive layer is 0.2-2 μm after the adhesive is dried.

8. The method of any one of claims 1 to 7, further comprising subjecting the resulting ultra-thin metal composite film to an external surface corrosion resistant treatment and/or appearance improvement;

preferably, the appearance improvement comprises any one or a combination of at least two of hole sealing treatment, resin coating protection, paint spraying, paint coloring or marking of the passivation process.

9. An ultrathin metal composite film, characterized in that the ultrathin metal composite film is obtained by the preparation method of any one of claims 1 to 8.

10. Use of the ultra-thin metal composite film of claim 9 in the fields of food packaging, electromagnetic shielding, energy storage and consumer electronics.