A water electroplating method and equipment for composite copper foil film

Abstract

The present invention discloses a water electroplating method and equipment for composite copper foil. The water electroplating equipment includes a copper electroplating tank and a protective electroplating tank. A polyester film formed with a metallic copper sputtering layer is fed into the copper electroplating tank to form a metallic copper electroplating layer. The polyester film formed with the metallic copper electroplating layer is fed from the copper electroplating tank to the protective electroplating tank to form a protective layer. This application completely eliminates the conductive roller by connecting the polyester film formed with the metallic copper sputtering layer to the negative electrode of a power supply via a first conductive liquid; and connecting the polyester film formed with the metallic copper electroplating layer to the negative electrode of the power supply via a second conductive liquid. This allows the metallic copper sputtering layer on the polyester film to be connected to the negative electrode of the power supply via a non-contact liquid method, thereby eliminating the problem of forming a plating layer on the conductive roller that punctures the film as in the prior art.

Description

Technical Field

[0001] The present application relates to a method and apparatus for manufacturing a composite copper foil film that can be used as a negative electrode current collector for lithium-ion batteries, and in particular to a water electroplating method and apparatus for the composite copper foil film. Background Art

[0002] The current collector in a lithium-ion battery is made of a conductive metal foil. Its primary function is to carry the positive and negative electrode materials, collecting current and conducting electrons. Aluminum foil is commonly used as the positive current collector, while copper foil is commonly used as the negative current collector.

[0003] CN 114481080 A discloses an integrated vacuum plating and water plating device and a method for producing ultra-thin copper foil. The device includes a vacuum chamber, a winding device for winding a thin film, a vacuum chamber for vacuum evaporation of the film in the winding device, and an electroplating device for electroplating the evaporated film. The prior art copper foil requires evaporating a target material into a gas at high temperature before attaching it to the surface of a non-metallic substrate layer. The higher the evaporation temperature of the target material, the more susceptible the substrate layer is to defects such as melting or burning. Therefore, the prior art generally produces composite aluminum foil through evaporation, and composite copper foil is rarely produced by evaporation because copper has a higher evaporation temperature. The higher the evaporation temperature of the target material, the faster the substrate layer needs to be operated, resulting in a thinner copper layer formed by evaporation. This also deteriorates the conductive properties of the copper foil, making it unsuitable for use as a current collector in lithium-ion batteries. Furthermore, because evaporation requires the film to be moved at a relatively high speed, the copper layer obtained by evaporation is not only difficult to increase in thickness, but also suffers from poor density and uniformity, making it prone to shedding. Furthermore, due to the thickness and density of the evaporated copper layer, its sheet resistance is very high, resulting in high energy consumption during subsequent electroplating.

[0004] Regarding water electroplating processes, CN 113755917 A discloses an electroplating system comprising an unwinding mechanism, multiple cleaning and plating devices, and a winding mechanism, each of which includes a cleaning mechanism and an electroplating mechanism. The cleaning mechanism includes a first liquid reservoir, a first roller, a first conductive roller, and a second conductive roller. The first liquid reservoir stores a cleaning solution. The first roller, the first conductive roller, and the second conductive roller are all rotatably connected to the first liquid reservoir, with the second conductive roller submerged below the level of the cleaning solution. This prior art solves the problem of copper plating and crystal formation on the conductive rollers in electroplating systems, which can puncture the product to be plated. As can be seen from the description of this prior art, in processes involving electroplating on thin film surfaces, special consideration must be given to the copper plating of the conductive rollers to prevent them from puncturing the film. However, this requires the installation of an additional cleaning device along the film's travel direction, which makes it difficult to completely prevent residual plating solution from gradually accumulating on the conductive rollers. Regular cleaning of the conductive rollers is required, which not only increases costs and energy consumption but also reduces production efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present application is to provide a water electroplating method and equipment for composite copper foil film to reduce or avoid the problems mentioned above.

[0006] In order to solve the above technical problems, the present application proposes a water electroplating equipment for a composite copper foil film, wherein the composite copper foil film includes a base layer composed of a polyester film, a metal copper sputtering layer attached to both sides of the base layer, and a metal layer electroplating layer and a protective layer formed on the outside of the metal copper sputtering layer, wherein the water electroplating equipment includes a copper electroplating tank and a protective electroplating tank, the polyester film formed with the metal copper sputtering layer is input into the copper electroplating tank and forms a metal copper electroplating layer; the polyester film formed with the metal copper electroplating layer is input from the copper electroplating tank into the protective electroplating tank and forms a protective layer.

[0007] Preferably, along the direction in which the polyester film is input into the copper electroplating tank, a first liquid conductive tank is provided at the upstream and downstream of the copper electroplating tank, respectively, and the polyester film formed with a metal copper sputtering layer is connected to the negative electrode of the power supply by contacting the first conductive liquid in the first liquid conductive tank; along the direction in which the polyester film is input into the protective electroplating tank, a second liquid conductive tank is provided at the upstream and downstream of the protective electroplating tank, respectively, and the polyester film formed with a metal copper electroplating layer is connected to the negative electrode of the power supply by contacting the second conductive liquid in the second liquid conductive tank; the first liquid conductive tank and the second liquid conductive tank are respectively immersed with a first metal electrode and a second metal electrode that are conductive to the negative electrode of the power supply.

[0008] Preferably, a first turning roller is provided below the liquid surface of the first liquid conductive tank, and a polyester film with a metal copper sputtering layer is formed into the liquid surface below the first liquid conductive tank from above the liquid surface, and is turned to above the liquid surface by surrounding the first turning roller; a second turning roller is provided below the liquid surface of the second liquid conductive tank, and a polyester film with a metal copper electroplating layer is formed into the liquid surface below the second liquid conductive tank from above the liquid surface, and is turned to above the liquid surface by surrounding the second turning roller.

[0009] Preferably, the first conductive liquid in the first liquid conductive tank has the same composition as the copper electroplating liquid in the copper electroplating tank; the second conductive liquid in the second liquid conductive tank has the same composition as the protective electroplating liquid in the protective electroplating tank.

[0010] Preferably, the copper plating solution in the copper plating tank is immersed in a copper metal electrode that is conductive to the positive pole of the power supply; and the protective plating solution in the protective plating tank is immersed in a protective metal electrode that is conductive to the positive pole of the power supply.

[0011] Preferably, at least one third turning roller is provided below the liquid surface of the copper electroplating tank, and the polyester film enters from above the liquid surface of the copper electroplating tank below the liquid surface and turns to above the liquid surface by surrounding the third turning roller; at least one fourth turning roller is provided below the liquid surface of the protective electroplating tank, and the polyester film enters from above the liquid surface of the protective electroplating tank below the liquid surface and turns to above the liquid surface by surrounding the fourth turning roller.

[0012] Preferably, a plurality of tension rollers are provided between the first liquid conductive tank, the copper electroplating tank, the second liquid conductive tank and the protective electroplating tank.

[0013] The present application also proposes a water electroplating method for a composite copper foil film, wherein the composite copper foil film includes a substrate layer composed of a polyester film, a metal copper sputtering layer attached to both sides of the substrate layer, and a metal layer electroplating layer and a protective layer formed on the outside of the metal copper sputtering layer, wherein the water electroplating method includes the following steps: inputting the polyester film formed with the metal copper sputtering layer into a copper electroplating tank, and forming a metal copper electroplating layer on the outside of the metal copper sputtering layer by an electroplating process; inputting the polyester film formed with the metal copper electroplating layer from the copper electroplating tank into a protective electroplating tank, and forming a protective layer on the outside of the metal copper electroplating layer by an electroplating process.

[0014] Preferably, the polyester film formed with the metal copper sputtering layer is connected to the negative electrode of the power supply through a first conductive liquid; the polyester film formed with the metal copper electroplating layer is connected to the negative electrode of the power supply through a second conductive liquid.

[0015] Preferably, the first conductive liquid and the second conductive liquid are respectively soaked with a first metal electrode and a second metal electrode connected to the negative electrode of the power supply, and the polyester film and the first metal electrode and the second metal electrode are connected to the negative electrode of the power supply via a non-contact liquid method.

[0016] The present application connects a polyester film formed with a metal copper sputtering layer to the negative electrode of a power supply through a first conductive liquid; connects a polyester film formed with a metal copper electroplating layer to the negative electrode of a power supply through a second conductive liquid, thereby completely removing the conductive roller, allowing the metal copper sputtering layer on the polyester film to connect to the negative electrode of the power supply through the first conductive liquid and the second conductive liquid in a non-contact liquid manner, thereby eliminating the situation in the prior art where a plating layer that punctures the film is formed on the conductive roller. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following drawings are only intended to illustrate and explain the present application and are not intended to limit the scope of the present application.

[0018] Figure 1 Shown is a schematic structural diagram of a composite copper foil film according to a specific embodiment of the present application.

[0019] Figure 2 Shown is a schematic structural diagram of a composite copper foil film according to another specific embodiment of the present application.

[0020] Figure 3 Shown is a schematic structural diagram of a system for manufacturing a composite copper foil film according to a specific embodiment of the present application.

[0021] Figure 4 Shown is a schematic structural diagram of a pre-plating processing device for a composite copper foil manufacturing system according to another specific embodiment of the present application.

[0022] Figure 5 Shown is a schematic structural diagram of a water electroplating device for a composite copper foil film according to a specific embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, objectives and effects of this application, the specific implementation of this application is now described with reference to the accompanying drawings, wherein the same components are marked with the same reference numerals.

[0024] like Figure 1-2 As shown, the present invention proposes a composite copper foil film that can be used as a negative electrode current collector for lithium-ion batteries. The composite copper foil film is composed of a substrate layer 1 and a conductive layer 2 attached to both sides of the substrate layer 1. The conductive layer 2 is primarily composed of metallic copper. As previously mentioned, due to the high evaporation temperature of metallic copper, if it is deposited on the surface of the polymer substrate layer 1 by evaporation, the uniformity of the substrate layer 1's surface structure will be destroyed. It is also difficult to achieve the thickness required for sufficient electrical performance. Moreover, the thicker the stack, the more likely it is to shed powder, making it unsuitable for use as a negative electrode current collector.

[0025] In view of this, the present application proposes a composite copper foil film, wherein the conductive layer 2 adopts a multi-layer conductive structure. In the specific embodiment shown in the figure, the conductive layer 2 includes, from the inside to the outside, a metal copper sputtering layer 21, a metal copper electroplating layer 22, and a protective layer 23. The metal copper sputtering layer 21 is a layer of metal copper with a thickness of 5-15 nm formed on both sides of the substrate layer 1 by a vacuum sputtering process. The metal copper electroplating layer 22 is a layer of metal copper with a thickness of 100-500 nm formed by growing on the outer surface of the metal copper sputtering layer 21 by a water electroplating process. The protective layer 23 is a dense protective layer formed by passivating the outer surface of the metal copper electroplating layer 22 by electroplating or chemical etching. Preferably, the protective layer 23 is a 5-15 nm metal chromium protective layer formed by electroplating.

[0026] In the composite copper foil film of the present application, the density and adhesion of the metal copper sputtering layer formed by vacuum sputtering are far superior to those of the evaporation process, and because the required thickness is very thin, the operation speed of the substrate layer can be very fast, which basically eliminates the possibility of defects such as melting or scalding in the substrate layer. Although the thickness of the metal copper sputtering layer is very thin, it can provide basic conductive properties, and thus a thicker metal copper layer can be further grown on its surface by water electroplating. Through the combination of the vacuum sputtering process and the water electroplating process, the present application can obtain excellent electrical properties and adhesion without destroying the surface structure of the substrate layer, which will be further explained later.

[0027] In addition, in order to avoid the problem of insufficient adhesion of the metal copper layer due to the uneven surface structure of the substrate layer, the present application also proposes an improved substrate layer 1. In a specific embodiment of the present application, the substrate layer 1 of the present application is made of a polyester film added with a polyester functional masterbatch. The substrate layer 1 can be a polyester film with a three-layer structure including a surface layer A, a core layer B, and a bottom layer C, wherein the surface layer and the bottom layer are added with the polyester functional masterbatch ( Figure 1 ), or a single-layer polyester film with polyester functional masterbatch added ( Figure 2 ).

[0028] The polyester referred to in the present invention refers to a polyester formed from one or more polycarboxylic acids selected from dibasic acids and their ester-forming derivatives, and one or more polyols selected from diols; or a polyester formed from hydroxycarboxylic acids and their ester-forming derivatives; or a polyester formed from cyclic esters. The production of polyester can be carried out according to conventional methods. For example, taking the preparation of PET as an example, it can be obtained by the following methods: esterification of terephthalic acid and ethylene glycol followed by polycondensation; or by transesterification of an alkyl ester of terephthalic acid, such as dimethyl terephthalate, with ethylene glycol followed by polycondensation. The polyester of the present invention is preferably PET.

[0029] In a specific embodiment, the polyester film constituting the substrate layer 1 is a single-layer polyester film containing 5 to 20 wt% of a polyester functional masterbatch, or a three-layer polyester film comprising a surface layer A, a core layer B, and a bottom layer C, wherein the surface layer A and the bottom layer C contain 5 to 20 wt% of a polyester functional masterbatch, and the polyester functional masterbatch is prepared from raw materials including the following parts by weight: 30-50 parts by weight of polyisophthalamide, 1-3 parts by weight of cobalt neodecanoate, 3-5 parts by weight of dibutylhydroxytoluene, 5 to 10 parts by weight of 1,4-diiodobenzene, 20 to 30 parts by weight of silica, and 50-100 parts by weight of PET.

[0030] The polyester functional masterbatch of the present invention can be prepared in the form of pellets or slices and added to ordinary polyester during the production of polyester film to produce the substrate layer 1 of the present invention. For example, 80-95 wt% of polyester without other ingredients can be melt-blended with 5-20 wt% of the polyester functional masterbatch of the present invention, and then a single-layer substrate layer 1 can be produced through a stretching process, or the surface structure of the substrate layer 1 of the present invention can be obtained through a multi-layer co-extrusion process.

[0031] The various raw material components of the polyester functional masterbatch of the present invention can be uniformly mixed in the form of granules, and then extruded and granulated using equipment such as an extruder to obtain the polyester functional masterbatch of the present invention.

[0032] In a specific embodiment, 50-100 parts by weight of powdered PET, 20-30 parts by weight of nano-silicon dioxide, 30-50 parts by weight of powdered polyisophthalamide, 1-3 parts by weight of powdered cobalt neodecanoate, 3-5 parts by weight of powdered butylated hydroxytoluene, and 5-10 parts by weight of powdered 1,4-diiodobenzene can be added to a mixer at room temperature for pre-dispersion and mixing at a speed of 1500-2000 rpm for 30-60 minutes to form a mixture. The mixture is then melt-extruded through a twin-screw extruder, and then water-cooled for granulation or slicing to obtain the polyester functional masterbatch.

[0033] In another specific embodiment, for example, after preparing the polyester functional masterbatch slices, 5 to 20 wt% of the polyester functional masterbatch is taken and added to 80 to 95 wt% of PET particles and evenly mixed. The two are melt-blended and finally a single-layer substrate layer 1 is obtained by stretching and other processes, or the surface layer A and bottom layer B of the three-layer substrate layer 1 are obtained by a multi-layer co-extrusion process.

[0034] The following is an example of a single-layer polyester film to further illustrate the preparation method of the polyester film for composite copper foil film of the present invention. The preparation method of the polyester film for composite copper foil film of the present invention comprises the following steps:

[0035] The following components in weight ratio: 80-95 wt% of PET resin and 5-20 wt% of polyester functional masterbatch are measured by electronic scale respectively and put into a mixing bin for mixing to prepare a mixture.

[0036] The mixed material then enters a venting twin-screw extruder, and the temperature of the twin-screw extruder is adjusted to 270°C to 280°C.

[0037] After the material is melted in the extruder, it is filtered and extruded into thick sheets. The thickness and profile of the thick sheets can be adjusted by adjusting the extruder output, the speed of the casting roller, and the opening of the die.

[0038] The thick sheet is preheated at 50°C to 90°C, placed in an infrared heating zone at 300°C to 500°C, and longitudinally stretched at a line speed of 40 to 150 m / min with a longitudinal stretching ratio of 4.0 to obtain a stretched sheet.

[0039] The stretched sheet is preheated at 90°C to 120°C, stretched transversely at 100°C to 160°C, and stretched at a transverse stretching ratio of 3.8. It is then shaped at 160°C to 240°C, and then cooled at 100°C to 50°C to obtain a polyester film for composite copper foil.

[0040] The thickness of the prepared polyester film is 6-10 μm.

[0041] The following is an example of a three-layer polyester film to further illustrate the preparation method of the polyester film for composite copper foil film of the present invention. The preparation method of the polyester film for composite copper foil film of the present invention comprises the following steps:

[0042] The following components in weight ratio: 80-95 wt% of PET resin and 5-20 wt% of polyester functional masterbatch are measured by electronic scale respectively and put into a mixing bin for mixing to prepare a mixture.

[0043] The mixed material then enters the vented twin-screw extruder E.

[0044] 100% PET resin was put into the pre-crystallizer and pre-crystallized at 160°C for 15 minutes. The PET material then entered the drying tower and was dried at 160°C for 6 hours before entering the single-screw extruder F.

[0045] Adjust the temperature of twin-screw extruders E and F to 270°C to 280°C.

[0046] After the materials are melted in two extruders and filtered, the material extruded from twin-screw extruder E is used as the surface layer A and bottom layer C, and the material extruded from single-screw extruder F is used as the core layer B. Through a multi-layer co-extrusion process, a three-layer composite slab is produced. The thickness and profile of the slab can be adjusted by adjusting the extruder output, casting roller speed, and die opening.

[0047] The thick sheet is preheated at 50°C to 90°C, placed in an infrared heating zone at 300°C to 500°C, and longitudinally stretched at a line speed of 40 to 150 m / min with a longitudinal stretching ratio of 4.0 to obtain a stretched sheet.

[0048] The stretched sheet is preheated at 90°C to 120°C, stretched transversely at 100°C to 160°C with a transverse stretch ratio of 3.8, then shaped at 160°C to 240°C, and cooled at 100°C to 50°C to obtain the three-layer polyester film.

[0049] The thickness of the prepared polyester film is 6-10 μm, wherein the thickness of layer A is 1-2 μm, the thickness of layer B is 2-8 μm, and the thickness of layer C is 1-2 μm.

[0050] Examples 1-5

[0051] According to the weight ratio of the raw materials in the table below, polyester functional masterbatch chips were prepared respectively, and then ordinary PET resin was added to prepare a single-layer polyester film for composite copper foil film.

[0052] Example 1 Example 2 Example 3 Example 4 Example 5 Poly(m-xylylene diamide) 30 35 40 45 50 Cobalt neodecanoate 1 1.5 2 2.5 3 Butylated hydroxytoluene 3 3.5 4 4.5 5 1,4-Diiodobenzene 5 7 7.5 8 10 Silicon dioxide 20 22 25 27 30 PET 50 65 75 85 100 Amount of slices for preparing a single substrate layer 5wt% 10wt% 13wt% 15wt% 20wt% Substrate layer thickness μm 6 7 8 9 10

[0053] Comparative Examples 6-10

[0054] In the same manner as in the above example, a polyester film for comparison was prepared according to the weight ratio of the raw materials shown in the following table.

[0055] Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Poly(m-xylylene diamide) 0 35 40 45 50 Cobalt neodecanoate 1 0 2 2.5 3 Butylated hydroxytoluene 3 3.5 0 4.5 5 1,4-Diiodobenzene 5 7 7.5 0 10 Silicon dioxide 20 22 25 27 0 PET 80 66.5 79 93 130 Amount of slices for preparing a single substrate layer 5wt% 10wt% 13wt% 15wt% 20wt% Substrate layer thickness μm 6 7 8 9 10

[0056] The performance parameters of each polyester film were tested and prepared respectively, and an 8μm thick film prepared from pure PET without adding any functional masterbatch was compared. The performance parameters are shown in the following table.

[0057]

[0058] Metal copper sputtering layers were formed on both sides of the polyester film described in the above table by a vacuum sputtering process. The thickness of the metal copper layers on both sides by vacuum sputtering was controlled to be 5 nm. The surface crack parameters of the prepared films were tested.

[0059]

[0060] It can be seen from the performance parameters of the above-mentioned film layer and the cracks in the metal plating layer that the polyester film prepared by adding the polyester functional masterbatch of the present application has greatly improved properties such as porosity, water absorption, and oxygen permeability, and no obvious crack expansion is observed after the metal copper conductive layer is formed.

[0061] Furthermore, the resistivity difference of the metal copper sputtered layers on both sides of the polyester film shown in the above table was tested, as shown in the following table.

[0062]

[0063]

[0064] The resistivity difference of the metal copper sputtering layer formed on the polyester film prepared by adding the polyester functional masterbatch of the present application is significantly smaller than that of the film without adding the functional masterbatch, indicating that the structure on both sides has better consistency.

[0065] Furthermore, since this application requires first forming a metallic copper sputtering layer 21 on the surface of the substrate layer 1, the substrate layer 1 must be operated at a relatively low temperature during sputtering. Although the improved polyester film of the substrate layer 1 has excellent properties such as porosity, water absorption, and oxygen permeability, it is still necessary to prevent the problem of water absorption on the polyester film surface at low temperatures and subsequent release of water during sputtering, which may interfere with the vacuum level.

[0066] Therefore, in one embodiment, Figure 2 As shown, to prevent moisture absorption and release by substrate layer 1 during sputtering, a barrier layer 11 is sputtered on the outer side of substrate layer 1 between conductive layer 2 and substrate layer 1 to improve the performance of conductive layer 2. Specifically, a 2-3 nm thick barrier layer 11 composed of silicon dioxide can be deposited on both sides of substrate layer 1 using a dual-rotating cathode and medium-frequency reactive magnetron sputtering method to coat and isolate the surface of substrate layer 1 and form a hydrophobic structure on the surface of substrate layer 1.

[0067] Furthermore, since the barrier layer 11 is very thin, in order to improve the adhesion of the barrier layer 11 to the surface of the substrate layer 1, the surface of the substrate layer 1 is preferably subjected to a corona treatment before the barrier layer 11 is sputtered to form a corona layer 10 with a thickness of 1-2 nm. The barrier layer 11 is formed on the outside of the corona layer 10. Corona treatment is an existing technology. Its basic principle is to use high-frequency and high-voltage corona discharge on the surface of the treated plastic to roughen the surface of the substrate layer 1, thereby increasing the adhesion of the substrate layer 1 to the barrier layer 11.

[0068] Of course, those skilled in the art will appreciate that the corona layer 10 and the barrier layer 11 may also be formed on Figure 1The surface of the base material layer 1 is composed of a polyester film having a three-layer structure.

[0069] Refer to the following Figure 3-4 The manufacturing system for the composite copper foil film of the present application is further described.

[0070] As shown in the figure, the manufacturing system for composite copper foil film of the present application includes a film-making device 100 for preparing a polyester film constituting a substrate layer 1, a pre-coating treatment device 200 for pre-treating the polyester film and forming a metal copper sputtering layer 21 on both sides thereof, and a water electroplating device 300 for forming a metal layer electroplating layer 22 and a protective layer 23 on the outside of the metal copper sputtering layer 21.

[0071] The film-making apparatus 100 includes a mixer 101 for preparing a polyester functional masterbatch and a first extruder 102. As previously mentioned, the following raw materials can be added to the mixer 101 at room temperature in parts by weight: 30-50 parts by weight of poly(m-xylylene diamide), 1-3 parts by weight of cobalt neodecanoate, 3-5 parts by weight of butylated hydroxytoluene, 5-10 parts by weight of 1,4-diiodobenzene, 20-30 parts by weight of silica, and 50-100 parts by weight of PET. More specifically, 50-100 parts by weight of powdered PET, 20-30 parts by weight of nano-silicon dioxide, 30-50 parts by weight of powdered polyisophthalamide, 1-3 parts by weight of powdered cobalt neodecanoate, 3-5 parts by weight of powdered butylated hydroxytoluene, and 5-10 parts by weight of powdered 1,4-diiodobenzene can be added to a mixer 101 for pre-dispersion and mixing at a speed of 1500-2000 rpm for 30-60 minutes to form a mixed material. The mixed material is then melt-extruded through a first extruder 102 (e.g., a twin-screw extruder), and then water-cooled for granulation or slicing to obtain the polyester functional masterbatch.

[0072] The polyester functional masterbatch output from the first extruder 102 and the ordinary PET resin input from the ordinary PET resin feed pipe 103 are fed into the mixing silo 104 through a pipeline, uniformly mixed, and further fed into the second extruder 105. As previously described, for example, 5-20 wt% of the polyester functional masterbatch obtained from the first extruder 102 and 80-95 wt% of the ordinary PET resin input from the ordinary PET resin feed pipe 103 can be fed into the mixing silo 104 to be mixed to form a mixed material, which then enters the second extruder 105 (e.g., a vented twin-screw extruder E).

[0073] The polyester functional masterbatch melted by the second extruder 105 is input into the film preparation mechanism 108 through the surface layer pipe and the bottom layer pipe respectively to prepare the surface layer A and the bottom layer C of the polyester film, and the ordinary PET resin is input into the film preparation mechanism 108 through the third extruder 109 (for example, a single-screw extruder F) and the core layer pipe to prepare the core layer B of the polyester film. As mentioned above, for example, the material extruded by the twin-screw extruder E is used as the surface layer A and the bottom layer C, and the material extruded by the single-screw extruder F is used as the core layer B, and a three-layer composite thick sheet is made through the multi-layer co-extrusion process of the film preparation mechanism 108; the above-mentioned thick sheet is preheated at a temperature of 50℃~90℃, enters the infrared heating zone of 300℃~500℃, and is longitudinally stretched at a line speed of 40~150m / min, and the longitudinal stretching ratio is 4.0 to obtain a stretched sheet; the stretched sheet is preheated at a temperature of 90℃~120℃, and is transversely stretched at a temperature of 100℃~160℃, and the transverse stretching ratio is 3.8; thereafter, it is shaped at a temperature of 160℃~240℃, and then cooled at a temperature of 100℃~50℃ to obtain a three-layer polyester film.

[0074] Furthermore, if Figure 4 As shown, the pre-coating treatment equipment 200 includes a corona chamber 201, an annular vacuum sputtering chamber 202 and a receiving chamber 203 for performing corona treatment on the surface of the polyester film prepared by the film-making equipment 100 to obtain a corona layer 10; the corona-treated polyester film is input from the corona chamber 201 into the annular vacuum sputtering chamber 202, and through the annular vacuum sputtering chamber 202, a barrier layer 11 is sputtered on the outside of the corona layer 10 to form a metal copper sputtering layer 21 is sputtered on the outside of the barrier layer 11; the polyester film with the metal copper sputtering layer 21 is input from the annular vacuum sputtering chamber 202 into the receiving chamber 203 to receive the polyester film into a roll.

[0075] The corona chamber 201, the annular vacuum sputtering chamber 202, and the receiving chamber 203 form an integrated structure. To maintain the vacuum level of the annular vacuum sputtering chamber 202 during refueling, refueling gates 2025 are installed at the feed and discharge ports of the annular vacuum sputtering chamber 202. These gates are used to isolate the annular vacuum sputtering chamber 202 from the corona chamber 201 and the receiving chamber 203 during refueling, as shown in the figure. The refueling gates 2025 are arranged in pairs outside the feed and discharge ports of the annular vacuum sputtering chamber 202. A slit is left between the refueling gates 2025 for the polyester film to pass through. When the gates are closed, the polyester film is clamped in the middle, allowing the polyester film extending from the annular vacuum sputtering chamber 202 to be attached to the ends of the new feed and receiving reels, respectively, completing the refueling process.

[0076] The corona chamber 201 is provided with multiple sets of tension rollers to maintain the tension of the polyester film during operation. The corona chamber 201 is provided with a corona electrode 2011 for forming a corona layer 10 on at least one side of the polyester film.

[0077] As can be seen from the structure in the figure, the pre-coating treatment equipment 200 can only form the barrier layer 11 and the metallic copper sputtering layer 21 on one side of the polyester film after a single operation. Therefore, in order to form the barrier layer 11 and the metallic copper sputtering layer 21 on both sides of the polyester film, it is necessary to reload the polyester film roll into the corona chamber 201 after the sputtering is completed, and sputtering is performed again on the other side of the polyester film. Therefore, the corona electrode 2011 in the corona chamber 201 only needs to be set up with one set of structures, and the corona layer 10 only needs to be formed on the side that needs sputtering, and then the barrier layer 11 can be easily formed on the corona layer 10.

[0078] A hollow cooling roller 2029 is provided in the middle of the annular vacuum sputtering chamber 202. When working, a cooling medium passes through the cooling roller 2029, and the polyester film runs closely on the outside of the cooling roller 2029. The cooling roller 2029 cools the polyester film to about minus 20-30 degrees Celsius to prevent the polyester film from being burned during sputtering.

[0079] Surrounding the cooling roller 2029, multiple sputtering chambers are arranged in the annular vacuum sputtering chamber 202. A total of seven chambers are shown in the figure, among which the middle chamber is not provided with sputtering material, and there are three chambers on each side that can be used as sputtering chambers.

[0080] The annular vacuum sputtering chamber 202 includes at least one barrier material sputtering chamber 2021 disposed upstream, and the barrier material sputtering chamber 2021 includes at least one copper material sputtering chamber 2022 downstream. For example, the first two sputtering chambers upstream of the polyester film can be configured as barrier material sputtering chambers 2021, in which two counter-rotating rod materials, such as silicon dioxide barrier layers, can be disposed. During sputtering, the rod materials serve as a raw material supply source, sputtering barrier materials such as silicon dioxide onto the polyester film under high pressure. Counter-rotating rod materials can form a more uniform sputtering layer structure. The other four sputtering chambers downstream of the barrier material sputtering chamber 2021 can be configured as copper material sputtering chambers 2022, wherein the first two sputtering chambers are provided with counter-rotating copper rod materials. According to actual needs, only the first upstream sputtering chamber can be used as the barrier material sputtering chamber 2021, and the subsequent three sputtering chambers can be used as the copper material sputtering chamber 2022. The last two sputtering chambers can be set with a single copper rod material to form a metal copper sputtering layer 21 distributed in the same direction on the outermost side, so that the production speed of the copper layer during subsequent water electroplating can be kept consistent.

[0081] In order to prevent the interference of water vapor on the surface of the polyester film on the sputtering, at least one first infrared heating unit 2023 is provided on one side of the feed port of the annular vacuum sputtering chamber 202 to remove water vapor and bake the input polyester film.

[0082] Furthermore, because the polyester film is maintained at an extremely low temperature during sputtering, condensation easily forms on the low-temperature polyester film once it enters the receiving chamber 203. Therefore, at least one second infrared heating unit 2024 is provided on the discharge side of the annular vacuum sputtering chamber 202 to heat the feed roller, which in turn further heats the discharged polyester film. Indirect heating of the feed roller is employed because the polyester film is very low in temperature. Direct heating would result in an uneven temperature field, easily causing burns or inconsistent heating temperatures. Therefore, indirect heating provides more uniform heating and is more efficient in raising the temperature of the polyester film.

[0083] Refer again Figure 3 , and refer to Figure 5 The water electroplating equipment 300 of the present application includes a copper electroplating tank 301 and a protective electroplating tank 302. The polyester film formed with a metal copper sputtering layer 21 is input into the copper electroplating tank 301 to form a metal copper electroplating layer 22; the polyester film formed with the metal copper electroplating layer 22 is input from the copper electroplating tank 301 to the protective electroplating tank 302 to form a protective layer 23. The specific process method is to input the polyester film formed with a metal copper sputtering layer 21 into the copper electroplating tank 301, and form the metal copper electroplating layer 22 on the outer side of the metal copper sputtering layer 21 by electroplating; and input the polyester film formed with the metal copper electroplating layer 22 from the copper electroplating tank 301 to the protective electroplating tank 302, and form the protective layer 23 on the outer side of the metal copper electroplating layer 22 by electroplating. As mentioned above, the thickness of the formed metal copper electroplating layer 22 is 100-500nm, and the thickness of the formed protective layer 23 is 5-15nm. Preferably, the protective layer 23 is a metal chromium protective layer.

[0084] As previously mentioned, although the thickness of the metallic copper sputtered layer is very thin, it can provide basic electrical conductivity. Therefore, after being processed by the pre-plating treatment equipment 200, a metallic copper sputtered layer 21 is formed on the surface of the polyester film. Then, using conventional water electroplating processes, a metallic copper electroplated layer 22 and a protective layer 23 can be formed in the copper electroplating tank 301 and the protective electroplating tank 302, respectively. For example, an electrolyte mainly composed of copper sulfate can be added to the copper electroplating tank 301, and an electrolyte mainly composed of chromic anhydride and sulfuric acid can be added to the protective electroplating tank 302. The thickness of the plating layer can be controlled by controlling the operating speed of the polyester film and the length of the electroplating tank.

[0085] The polyester film prepared in Examples 1-5 was used as the substrate layer, and was subjected to corona treatment, sputtering of a barrier layer, sputtering of a metal copper sputtering layer, electroplating of a metal copper electroplating layer, and electroplating of a protective layer to prepare a composite copper foil film with the following parameters.

[0086]

[0087] It can be seen from the measured parameters that the composite copper foil film of the present application has excellent electrical properties, and the conductive layer has extremely strong adhesion, and the conductive layer will hardly peel off during normal use.

[0088] Refer to the following Figure 5 The water electroplating equipment and method of the present application are further described in detail.

[0089] As shown, along the direction in which the polyester film is fed into the copper electroplating tank 301, a first liquid conductive tank 3011 is provided upstream and downstream of the copper electroplating tank 301. The polyester film, on which the metallic copper sputtered layer 21 is formed, is connected to the negative terminal of the power supply through contact with the first conductive liquid 3012 in the first liquid conductive tank 3011. As previously described, the first conductive liquid 3012 can be, for example, an electrolyte primarily composed of copper sulfate.

[0090] Similarly, along the direction in which the polyester film enters the protective plating tank 302, a second liquid conductive tank 3021 is provided upstream and downstream of the protective plating tank 302. The polyester film, on which the metallic copper electroplating layer 22 is formed, is connected to the negative terminal of the power supply through contact with the second conductive liquid 3022 in the second liquid conductive tank 3021. As previously described, the second conductive liquid 3022 can be, for example, an electrolyte primarily composed of chromic anhydride and sulfuric acid.

[0091] After being processed by the pre-coating equipment 200, the polyester film is coated with a metallic copper sputtering layer 21. Water electroplating through this metallic copper sputtering layer 21 typically requires contacting a conductive roller with the negative electrode of a power source to establish an electrical connection between the metallic copper sputtering layer 21. However, as the polyester film is processed, the electrolyte impregnated on the polyester film gradually transfers to the conductive roller. Since the conductive roller is electrically charged, the metal in the electrolyte is extracted and adheres to the conductive roller. Over time, a layer of metal is plated on the conductive roller. Because this metal layer is not plated normally, the coating is very uneven, which can easily puncture the film, resulting in product failure.

[0092] The specific process method of the present application completely does not use a conductive roller, but instead allows the metal copper sputtering layer 21 on the polyester film to contact the first conductive liquid 3012 and the second conductive liquid 3022, and connects the polyester film with the metal copper sputtering layer 21 to the negative electrode of the power supply through the first conductive liquid 3012; and connects the polyester film with the metal copper electroplating layer 22 to the negative electrode of the power supply through the second conductive liquid 3022.

[0093] Specifically, the first metal electrode 3013 and the second metal electrode 3023 connected to the negative pole of the power supply can be immersed in the first liquid conductive tank 3011 and the second liquid conductive tank 3021 respectively, so that the polyester film can be connected to the negative pole of the power supply through a non-contact liquid method with the first metal electrode 3013 and the second metal electrode 3023.

[0094] This application removes the conductive roller and allows the metal copper sputtering layer on the polyester film to be connected to the negative electrode of the power supply through a non-contact liquid method with the first conductive liquid and the second conductive liquid, thereby eliminating the situation in the prior art where a coating that punctures the film is formed on the conductive roller.

[0095] Further preferably, the first conductive liquid 3012 in the first liquid conductive tank 3011 can have the same composition as the copper plating solution in the copper plating tank 301; and the second conductive liquid 3022 in the second liquid conductive tank 3021 can have the same composition as the protective plating solution in the protective plating tank 302. This has the advantage that the polyester film passing through the first conductive liquid 3012 and the second conductive liquid 3022 does not need to be cleaned, eliminating the need to worry about the introduction of foreign impurities. Furthermore, for example, when the first liquid conductive tank 3011 is connected to the negative electrode via the first metal electrode 3013, the metallic copper sputtered layer will be slightly ionized. By setting the first conductive liquid 3012 to have the same composition as the copper plating solution in the copper plating tank 301, the copper ions in the first conductive liquid 3012 can be appropriately saturated, thereby mitigating the degree of ionization of the metallic copper sputtered layer. Alternatively, the first metal electrode 3013 can be a copper rod, so that when negative electrode ionization occurs, the first metal electrode 3013 is preferentially ionized, further mitigating the degree of ionization of the metallic copper sputtered layer. Similarly, by setting the second conductive liquid 3022 to have the same composition as the protective plating liquid of the protective plating tank 302, if the metal of the protective layer is chromium, the second metal electrode 3023 can also be set as a chromium alloy rod, which can also slow down the ionization degree of the protective layer.

[0096] Furthermore, as shown in the figure, a first deflection roller 3014 is provided below the liquid surface of the first conductive liquid tank 3011. A polyester film formed with a metallic copper sputtered layer 21 enters from above the liquid surface of the first conductive liquid tank 3011 below the liquid surface and is deflected toward the liquid surface by passing around the first deflection roller 3014. A second deflection roller 3024 is provided below the liquid surface of the second conductive liquid tank 3021. A polyester film formed with a metallic copper electroplated layer 22 enters from above the liquid surface of the second conductive liquid tank 3021 below the liquid surface and is deflected toward the liquid surface by passing around the second deflection roller 3024. It is preferable to minimize the number of rollers provided below the liquid surfaces of the first and second conductive liquid tanks 3011 and 3021. Furthermore, to avoid metal plating, the inner walls and structures within the first and second conductive liquid tanks 3011 and 3021 are made of non-conductive materials as much as possible. The first and second deflection rollers 3014 and 3024 are both made of non-conductive rubber, and the shafts of the two rollers are preferably made of, for example, self-lubricating nylon.

[0097] Furthermore, a copper metal electrode 3015 conductive to the positive pole of the power supply is immersed in the copper plating solution in the copper plating tank 301; a protective metal electrode 3025 conductive to the positive pole of the power supply is immersed in the protective plating solution in the protective plating tank 302. If the protective layer is chromium, the protective metal electrode is made of metallic chromium or a chromium alloy.

[0098] Furthermore, as shown in the figure, at least one third turning roller 3016 is provided below the liquid level of the copper electroplating tank 301. The polyester film enters from above the liquid level of the copper electroplating tank 301 and then moves to above the liquid level by passing around the third turning roller 3016. At least one fourth turning roller 3026 is provided below the liquid level of the protective electroplating tank 302. The polyester film enters from above the liquid level of the protective electroplating tank 302 and then moves to above the liquid level by passing around the fourth turning roller 3026. Of course, the interiors of the copper electroplating tank 301 and the protective electroplating tank 302 may adopt any existing structural style and are not limited to the specific structure shown in the figure.

[0099] Additionally, as shown in the figure, multiple tensioning rollers 303 can be installed between the first liquid conductive tank 3011, the copper electroplating tank 301, the second liquid conductive tank 3021, and the protective electroplating tank 302 to maintain the tension of the polyester film and prevent it from becoming entangled, overlapping, or tearing. These tensioning rollers 303 are also preferably made of a non-conductive material such as rubber. Furthermore, a film cleaning device 304 can be installed between the copper electroplating tank 301 and the protective electroplating tank 302 to prevent the conductive liquid in the front copper electroplating tank 301 from flowing into the rear protective electroplating tank 302 and causing contamination.

[0100] Those skilled in the art should understand that although this application is described in terms of multiple embodiments, not each embodiment contains only one independent technical solution. This description is only for the sake of clarity. Those skilled in the art should understand the description as a whole and understand the scope of protection of this application by considering the technical solutions involved in each embodiment as being combinable into different embodiments.

[0101] The above description is only an illustrative embodiment of the present application and is not intended to limit the scope of the present application. Any equivalent changes, modifications and combinations made by any person skilled in the art without departing from the concept and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. A water electroplating method for composite copper foil film, characterized in that: The method adopts a water electroplating device (300) to prepare the composite copper foil film, wherein the composite copper foil film comprises a base material layer (1) composed of a polyester film, a metal copper sputtering layer (21) attached to both sides of the base material layer (1), and a metal electroplating layer (22) and a protective layer (23) formed on the outside of the metal copper sputtering layer (21), wherein the water electroplating device (300) comprises a copper electroplating tank (301) and a protective electroplating tank (302), wherein the polyester film formed with the metal copper sputtering layer (21) is input into the copper electroplating tank (301) and forms the metal copper electroplating layer (22); the polyester film formed with the metal copper electroplating layer (22) is input from the copper electroplating tank (301) into the protective electroplating tank (302) and forms the protective layer (23); wherein the The substrate layer (1) is made of a polyester film to which a polyester functional masterbatch is added, wherein the polyester functional masterbatch is prepared from the following raw materials in parts by weight: 30-50 parts by weight of polyisophthalamide, 1-3 parts by weight of cobalt neodecanoate, 3-5 parts by weight of dibutylhydroxytoluene, 5-10 parts by weight of 1,4-diiodobenzene, 20-30 parts by weight of silicon dioxide, and 50-100 parts by weight of PET; the metal copper sputtering layer (21) is a layer of metal copper formed on both sides of the substrate layer by a vacuum sputtering process, the metal copper electroplating layer (22) is a layer of metal copper grown on the outer surface of the metal copper sputtering layer (21) by a water electroplating process, and the protective layer (23) is a metal chromium protective layer formed by an electroplating process; along the polyester film, the metal copper sputtering layer (21) is formed by a water electroplating process, and the protective layer (23) is a metal chromium protective layer formed by an electroplating process. In the direction in which the polyester film is input into the copper electroplating tank (301), a first liquid conductive tank (3011) is provided at the upstream and downstream of the copper electroplating tank (301), respectively. The polyester film formed with the metal copper sputtering layer (21) is connected to the negative electrode of the power supply by contacting the first conductive liquid (3012) in the first liquid conductive tank (3011); in the direction in which the polyester film is input into the protective electroplating tank (302), a second liquid conductive tank (3021) is provided at the upstream and downstream of the protective electroplating tank (302), respectively. The polyester film formed with the metal copper electroplating layer (22) is connected to the negative electrode of the power supply by contacting the second conductive liquid (3022) in the second liquid conductive tank (3021); the first liquid conductive tank (3011) and the second liquid conductive tank (3021) are connected to the negative electrode of the power supply. A first metal electrode (3013) and a second metal electrode (3023) connected to the negative electrode of a power supply are respectively immersed in the conductive tank (3021); a first turning roller (3014) is provided below the liquid surface of the first liquid conductive tank (3011); a polyester film formed with a metal copper sputtering layer (21) enters below the liquid surface of the first liquid conductive tank (3011) from above the liquid surface and turns to above the liquid surface by surrounding the first turning roller (3014); a second turning roller (3024) is provided below the liquid surface of the second liquid conductive tank (3021); a polyester film formed with a metal copper electroplating layer (22) enters below the liquid surface of the second liquid conductive tank (3021) from above the liquid surface and turns to above the liquid surface by surrounding the second turning roller (3024).

2. The method according to claim 1, wherein The first conductive liquid (3012) in the first liquid conductive tank (3011) has the same composition as the copper electroplating solution in the copper electroplating tank (301); and the second conductive liquid (3022) in the second liquid conductive tank (3021) has the same composition as the protective electroplating solution in the protective electroplating tank (302).

3. The method according to claim 2, wherein A copper metal electrode (3015) conductive to the positive electrode of a power supply is immersed in the copper plating solution in the copper plating tank (301); and a protective metal electrode (3025) conductive to the positive electrode of a power supply is immersed in the protective plating solution in the protective plating tank (302).

4. The method according to any one of claims 1 to 3, characterized in that At least one third turning roller (3016) is provided below the liquid surface of the copper electroplating tank (301), and the polyester film enters from above the liquid surface of the copper electroplating tank (301) below the liquid surface, and is turned to above the liquid surface by surrounding the third turning roller (3016); at least one fourth turning roller (3026) is provided below the liquid surface of the protective electroplating tank (302), and the polyester film enters from above the liquid surface of the protective electroplating tank (302) below the liquid surface, and is turned to above the liquid surface by surrounding the fourth turning roller (3026).

5. The method according to claim 4, wherein A plurality of tensioning rollers (303) are provided between the first liquid conductive tank (3011), the copper electroplating tank (301), the second liquid conductive tank (3021), and the protective electroplating tank (302).

6. The method according to any one of claims 1 to 3, characterized in that The inner side walls of the first liquid conductive groove (3011) and the second liquid conductive groove (3021) are made of non-conductive material.

7. The method according to any one of claims 1 to 3, characterized in that The first steering roller (3014) and the second steering roller (3024) are made of non-conductive rubber.

8. The method according to any one of claims 1 to 3, characterized in that The rotating shafts of the first steering roller (3014) and the second steering roller (3024) are made of nylon.

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