Magnetron sputtering coating method, coating equipment, current collector, preparation method and battery

Abstract

The invention provides a magnetron sputtering coating method, coating equipment, a current collector, a preparation method and a battery. The magnetron sputtering coating method comprises the following steps: placing a substrate in a sputtering chamber, controlling the substrate to move and enabling the substrate to gradually pass through a sputtering area; and monitoring whether the substrate has a concave area before reaching the sputtering area, and increasing the material sputtering amount at the concave area when monitoring that the concave area exists on the surface of the substrate. According to the preparation method, the surface flatness of the coating film layer can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of film coating technology, and in particular to a magnetron sputtering film coating method, a film coating device, a current collector, a preparation method and a battery. Background Art

[0002] Magnetron sputtering is a commonly used physical vapor deposition (PVD) technology that is widely used to prepare high-quality thin film materials. It uses a magnetic field to enhance the plasma density, thereby improving the sputtering efficiency and film quality, and can produce uniform, dense and highly adhesive films.

[0003] Dynamic magnetron sputtering is a technology that moves the substrate during the sputtering process. In order to ensure production efficiency and uniform film thickness, in the actual production process, the substrate often moves at a constant speed and gradually passes through the deposition area. However, in some specific scenarios, such as sputtering a thin film layer on the surface of a polymer film, the film surface often has a problem of low flatness. Summary of the invention

[0004] Based on this, it is necessary to provide a magnetron sputtering coating method that can improve the surface flatness of the coated layer during the coating process in order to address the problems in the above-mentioned background technology.

[0005] In a first aspect, the present disclosure provides a magnetron sputtering coating method, which comprises the following steps:

[0006] Placing a substrate in a sputtering chamber, controlling the movement of the substrate and gradually passing the substrate through a sputtering region;

[0007] The substrate before reaching the sputtering area is monitored to determine whether there is a recessed area. When it is detected that there is a recessed area on the surface of the substrate, the amount of material sputtered at the recessed area is increased.

[0008] In some embodiments of the present disclosure, the step of monitoring whether the substrate has a recessed area includes:

[0009] The substrate is irradiated with laser light and scattered light of the laser light is monitored, and changes in the scattered light are used to monitor whether a concave area exists in the substrate.

[0010] In some embodiments of the present disclosure, the spot size of the laser is 1 μm to 100 μm; and / or,

[0011] The wavelength of the laser is 450nm~1200nm.

[0012] In some embodiments of the present disclosure, the step of increasing the amount of material sputtering in the recessed area includes:

[0013] By reducing the moving speed of the substrate or making the recessed area of ​​the substrate stay under the sputtering area, the sputtering amount of the material in the recessed area is increased; and / or,

[0014] The sputtering direction of the target material is guided by adjusting the magnetic field to increase the amount of material sputtered in the recessed area.

[0015] In a second aspect, the present disclosure provides a magnetron sputtering coating device, the magnetron sputtering coating device comprising: a sputtering chamber, a transport mechanism, a flatness monitoring mechanism, and a control mechanism;

[0016] The transport mechanism and the flatness monitoring mechanism are arranged in the sputtering chamber, the transport mechanism is used to transport the substrate to be coated, the moving path of the transport mechanism passes through the sputtering area of ​​the sputtering chamber, the flatness monitoring mechanism is arranged before the sputtering area, the flatness monitoring mechanism is used to monitor whether there is a recessed area on the substrate before reaching the sputtering area, the control mechanism signal is connected to the flatness monitoring mechanism, and the control mechanism is used to control the magnetic field and / or control the transport speed of the transport mechanism according to the monitoring result of the flatness monitoring mechanism.

[0017] In some embodiments of the present disclosure, the flatness monitoring mechanism includes a laser source and a scattered light detector, the irradiation direction of the laser source is toward the moving path of the transportation mechanism, and the scattered light detector is arranged on the scattering path of the laser source and obtains the intensity of the scattered light.

[0018] In a third aspect, the present disclosure provides a method for preparing a current collector, which comprises the following steps: sputtering and depositing a conductive material layer on a substrate using a magnetron sputtering coating method as described in any of the above embodiments.

[0019] In a fourth aspect, the present disclosure provides a current collector prepared by the current collector preparation method as described in the above embodiment, wherein the height difference between the highest point and the lowest point on the surface of the conductive material layer is ≤20 nm.

[0020] In some embodiments of the present disclosure, the substrate is a polymer film, and the thickness of the substrate is 1 μm to 20 μm; and / or,

[0021] The conductive material layer may be made of one or more of copper, aluminum, iron and silver.

[0022] In a fifth aspect, the present disclosure provides a battery comprising a positive electrode plate and a negative electrode plate that are arranged opposite to each other, wherein the current collector in the positive electrode plate is the current collector described in the above embodiment; and / or, the current collector in the negative electrode plate is the current collector described in the above embodiment.

[0023] The present disclosure has found in the research process that the surface of the substrate used for film coating often has nanometer-level fluctuations. For example, the surface of a polymer film with a thickness of micrometer level often has some concave areas with a depth of several nanometers to tens of nanometers. When the thickness of the film layer is low, even if the thickness of the film layer is uniform, the surface of the film layer is still uneven, and the film layer deposited on the concave area of ​​the substrate also has a corresponding concave shape.

[0024] In the magnetron sputtering coating method disclosed in the present invention, the substrate is controlled to gradually pass through the sputtering area to gradually deposit the sputtering material on the substrate. In addition, before depositing the sputtering material, the substrate before reaching the sputtering area is monitored in situ to see whether there is a concave area. When the substrate surface is detected to have a concave, the amount of material sputtered at the concave area is increased, so that relatively more material is sputtered at the concave area, thereby compensating for the concave area while basically not affecting other areas. Therefore, the preparation method can effectively improve the surface flatness of the coated layer.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the steps of a magnetron sputtering coating method;

[0028] Figure 2 This is a schematic diagram of the cross-sectional structure of the magnetron sputtering coating equipment.

[0029] The reference numerals and their meanings are as follows:

[0030] 100. sputtering chamber; 200. flatness monitoring mechanism; 210. laser source; 220. scattered light detector; 300. transport mechanism; 400. substrate; 500. target material. DETAILED DESCRIPTION

[0031] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] The present disclosure has found in the research process that the surface of the substrate used for film coating often has nanometer-level fluctuations. For example, the surface of a polymer film with a thickness of micrometer level often has some concave areas with a depth of several nanometers to tens of nanometers. When the thickness of the film layer is low, even if the thickness of the film layer is uniform, the surface of the film layer is still uneven, and the film layer deposited on the concave area of ​​the substrate also has a corresponding concave shape.

[0040] The present disclosure provides a magnetron sputtering coating method, which includes the following steps: placing a substrate in a sputtering chamber, controlling the movement of the substrate and allowing the substrate to gradually pass through a sputtering area; and monitoring whether there is a recessed area on the substrate before reaching the sputtering area, and when a recessed area is detected on the surface of the substrate, increasing the amount of material sputtering at the recessed area.

[0041] In the magnetron sputtering coating method disclosed in the present invention, the substrate is controlled to gradually pass through the sputtering area to gradually deposit the sputtering material on the substrate. In addition, before depositing the sputtering material, the substrate before reaching the sputtering area is monitored in situ to see whether there is a concave area. When the substrate surface is detected to have a concave, the amount of material sputtered in the concave area is increased, so that relatively more material is sputtered in the concave area, thereby compensating for the concave area without substantially affecting other areas. Therefore, the preparation method can effectively improve the surface flatness of the coated layer.

[0042] In a first aspect, an embodiment of the present disclosure provides a magnetron sputtering coating method. Figure 1 Schematic diagram of the steps of the magnetron sputtering coating method. Figure 1 As shown, the magnetron sputtering coating method includes steps S1 and S2.

[0043] Step S1, placing a substrate in a sputtering chamber.

[0044] In this embodiment, the sputtering chamber may be a sputtering chamber of a magnetron sputtering device, which may contain a sputtering target material, and the target material can be deposited on a substrate after sputtering to form a corresponding thin film.

[0045] As an example of this embodiment, the material of the substrate may not be particularly limited, for example, the material of the substrate may include one or more of polymer, metal, glass, quartz and sapphire. In this embodiment, a polymer film is used as the substrate. The surfaces of metal, glass, quartz and sapphire are usually relatively flat. In contrast, in the actual production process, the surface of the polymer film is prone to produce many nanoscale concave areas. The magnetron sputtering coating method disclosed in the present invention is suitable for improving the flatness of the coating layer on the surface of the polymer film.

[0046] As an example of this embodiment, the height difference between the highest point and the lowest point on the substrate surface is ≥30nm. In some examples, the height difference between the highest point and the lowest point on the substrate surface can be 30nm~200nm. For example, the height difference between the highest point and the lowest point on the substrate surface can be 30nm, 40nm, 50nm, 60nm, 80nm, 100nm, 120nm, 150nm, 200nm, or the height difference between the highest point and the lowest point on the substrate surface can also be between any two of the above height differences. Among them, the height difference between the highest point and the lowest point can also be understood as the maximum unevenness of the substrate surface.

[0047] As an example of this embodiment, the thickness of the substrate is 1 μm to 20 μm. In some examples, the thickness of the substrate can be 1 μm, 2 μm, 3 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 20 μm, or the thickness of the substrate can be between any two of the above thicknesses.

[0048] Step S2, monitoring whether there is a concave area on the substrate before reaching the sputtering area, and when monitoring the presence of a concave area on the surface of the substrate, increasing the sputtering amount of the material in the concave area.

[0049] In this embodiment, since the depth of the recessed area on the substrate surface is at the nanometer level and the substrate is located in a sputtering chamber, in-situ monitoring of the recessed area with a nanometer depth is required to provide real-time feedback and increase the amount of material sputtering in the recessed area.

[0050] As an example of this embodiment, the step of monitoring whether there is a recessed area on the substrate includes: irradiating the substrate with a laser and monitoring the scattered light of the laser, and monitoring whether there is a recessed area on the substrate by the change of the scattered light. In this example, the laser is selected as the light source because the laser has extremely high directivity and localization, which makes the laser very sensitive to the morphological fluctuations of the substrate surface. It can be understood that when the laser is irradiated to the flat area on the surface of the substrate, the distribution of the scattered light remains unchanged or changes slightly, and when the laser is irradiated to the recessed area on the surface of the substrate, as the laser scans the recessed area, the distribution of the scattered light changes rapidly and then recovers. Therefore, when the scattered light changes as described above, it can be determined that the area scanned by the laser is a recessed area.

[0051] As an example of this embodiment, the spot size of the laser is 1μm~100μm. The spot size of the laser will affect its detection sensitivity. A laser with a spot size of 1μm~100μm can make the determination result of the recessed area more accurate. Specifically, when the spot size of the laser is less than 1μm, the scattered light is prone to large changes. For example, when there is a slight fluctuation in the internal environment of the sputtering chamber or the surface of the substrate, the scattered light will change significantly. At this time, the monitoring result is greatly affected by random errors, which may result in the undesirable sputtering of too much material in non-recessed areas, and thus lead to poor improvement effect on surface flatness. When the spot size of the laser is greater than 100μm, the variation amplitude of the scattered light is too small, which makes the monitoring result insensitive to smaller recessed areas, which may lead to missed judgment of some recessed areas and poor improvement effect on surface flatness.

[0052] In some examples, the spot size of the laser may be 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 70 μm, or 100 μm, or the spot size of the laser may be between any two of the above spot sizes.

[0053] As an example of this embodiment, the wavelength of the laser is 450nm~1200nm. That is, the laser can be a visible light laser or a near-infrared laser. By using the laser in the above-mentioned wavelength band, a more accurate monitoring effect can be obtained without substantially damaging the substrate. When the wavelength of the laser is less than 450nm, the energy of the laser is high, which can easily destroy the chemical bonds in the substrate, causing aging problems of the substrate and affecting the quality of the substrate. When the wavelength of the laser is greater than 1200nm, the diffraction phenomenon will be more significant, which will not only make it difficult to obtain a smaller spot size, but also affect the collection and analysis of scattered light.

[0054] It can be understood that in this embodiment, the energy density of the laser irradiated onto the substrate can be set to be relatively low to avoid damage to the substrate or undesirable local heating problems. When no concave area is detected on the surface of the substrate, it is only necessary to sputter to form a film layer with uniform thickness, that is, a film layer with high surface flatness can be obtained. Accordingly, the substrate can be controlled to pass through the sputtering area at a uniform speed and the magnetic field can be kept unchanged to obtain a film layer with uniform thickness.

[0055] In this embodiment, when a recessed area is detected on the substrate surface, the amount of material sputtered at the recessed area is increased, that is, more material is sputtered at the recessed area to fill the recessed area and improve the surface flatness of the film layer.

[0056] As an example of this embodiment, the step of increasing the amount of material sputtered in the recessed area includes: by reducing the moving speed of the substrate or allowing the recessed area of ​​the substrate to stay under the sputtering area, extending the sputtering time at the recessed area to increase the amount of material sputtered in the recessed area. It can be understood that reducing the moving speed of the substrate or allowing the recessed area of ​​the substrate to stay under the sputtering area can increase the amount of material sputtered in the recessed area, thereby improving the surface flatness of the film layer. This method is relatively simple and controllable, but when the recessed area is deep or the size of the recessed area is small, this method may also cause the problem of excessive sputtering in the flat area around the recessed area, which in turn limits the further improvement of the surface flatness.

[0057] As an example of this embodiment, the sputtering direction of the target material can be adjusted by adjusting the magnetic field to increase the amount of material sputtering in the recessed area. It can be understood that when adjusting the magnetic field, the field strength direction and the field strength can be adjusted to guide the sputtering direction and sputtering density of the target material. Among them, when adjusting the magnetic field to guide the sputtering direction of the target material, the sputtering material can be directionally deposited in the recessed area, thereby selectively increasing the amount of material sputtering in the recessed area. Compared with the regulation of the substrate movement process in the aforementioned method, by adjusting the magnetic field to guide the sputtering direction of the target material, more deposition can be performed on a certain area, thereby more effectively improving the surface flatness of the coating. However, the method of adjusting the magnetic field is more complicated and adjusting the magnetic field will also increase additional process time.

[0058] As an example of this embodiment, a movable mask may be provided, and when a recessed area is detected, the mask may be moved so that the recessed area is exposed from an opening of the mask to increase the amount of material sputtered at the recessed area.

[0059] As an example of this embodiment, the thickness of the film layer plated on the substrate is 10nm~300nm. For example, the thickness of the film layer plated on the substrate is 10nm, 20nm, 30nm, 50nm, 70nm, 100nm, 150nm, 200nm, 250nm, 300nm, or the thickness of the film layer plated on the substrate can also be between any two of the above thicknesses.

[0060] As an example of this embodiment, the material plated on the substrate may be selected from one or more of metals, metal oxides, and metal salts.

[0061] As an example of this embodiment, the height difference between the highest point and the lowest point on the surface of the plated film layer is ≤ 20 nm. For example, the height difference between the highest point and the lowest point on the surface of the plated film layer can be 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, or the height difference between the highest point and the lowest point on the surface of the plated film layer can be between any two of the above height differences.

[0062] It can be understood that, through the above steps S1 to S2, the magnetron sputtering coating method can be completed, and the coating method can prepare a film layer with higher surface flatness.

[0063] In a second aspect, the present disclosure also provides a magnetron sputtering coating device. Figure 2 Schematic diagram of the cross-sectional structure of the magnetron sputtering coating device. Figure 2 As shown, the magnetron sputtering coating equipment includes: a sputtering chamber 100, a transportation mechanism 300, a flatness monitoring mechanism 200 and a control mechanism (not shown in the figure).

[0064] Reference Figure 2 As shown, in this embodiment, a target 500 for providing sputtering material is arranged in the sputtering chamber 100, and a sputtering area is provided in the sputtering chamber 100, and the target 500 can be arranged toward the sputtering area. The transport mechanism 300 is arranged in the sputtering chamber 100, and the transport mechanism 300 is used to transport the substrate 400 to be coated. The moving path of the transport mechanism 300 passes through the sputtering area of ​​the sputtering chamber 100. When the transport mechanism 300 drives the substrate 400 to move, the movement can pass through the sputtering area.

[0065] Reference Figure 2 As shown, in this embodiment, the flatness monitoring mechanism 200 is also arranged in the sputtering chamber 100, and the flatness monitoring mechanism 200 is arranged before the sputtering area, and the flatness monitoring mechanism 200 is used to monitor whether there is a concave area in the substrate 400 before reaching the sputtering area. The control mechanism signal is connected to the flatness monitoring mechanism 200. Among them, the control mechanism can control the field strength of the magnetic field and / or the transportation speed of the transportation mechanism 300. The control mechanism is used to control the magnetic field and / or control the transportation speed of the transportation mechanism 300 according to the monitoring result of the flatness monitoring mechanism 200.

[0066] Reference Figure 2 As shown, as an example of this embodiment, the flatness monitoring mechanism 200 includes a laser source 210 and a scattered light detector 220, the irradiation direction of the laser source 210 is toward the moving path of the transportation mechanism 300, and the scattered light detector 220 is arranged on the scattering path of the laser source 210 and obtains the intensity of the scattered light.

[0067] As a further example of this embodiment, the spot size of the laser emitted by the laser source 210 can be 1 μm to 100 μm. The wavelength of the laser emitted by the laser source 210 is 450 nm to 1200 nm. The laser source 210 can be a visible light laser source 210 or an infrared light laser source 210. The scattered light detector 220 can be a conventional laser detector, such as a photodiode, a photomultiplier tube or a CCD camera.

[0068] As a further example of this embodiment, there may be multiple scattered light detectors 220, and the multiple scattered light detectors 220 are respectively arranged at different positions, which is conducive to receiving scattered light at multiple angles, thereby obtaining a more comprehensive scattered light distribution and improving the accuracy of the monitoring results.

[0069] As a further example of this embodiment, the control mechanism may be a central processing unit or a programmable logic controller.

[0070] As a further example of this embodiment, the transport mechanism 300 may be a conveyor belt or conveyor rollers.

[0071] In many application scenarios, the nanoscale undulations on the surface of the film layer will not have a significant impact on the quality and application of the film layer, so this problem will not be raised. The composite current collector usually includes a polymer film and a conductive material layer disposed on the polymer film. There are often some depressions on the sputtered conductive material layer. When the composite current collector is further used in a battery, it is easy to have a significant impact on the distribution of the electric field during rapid charging and discharging, and thus easily induce the formation of lithium dendrites.

[0072] In a third aspect, the present disclosure further provides a method for preparing a current collector, which comprises the following steps: sputtering and depositing a conductive material layer on a substrate using a magnetron sputtering coating method as described in any of the above embodiments.

[0073] In a fourth aspect, the present disclosure further provides a current collector. The current collector is prepared by the above-mentioned preparation method. The current collector comprises a substrate and a conductive material layer, and the height difference between the highest point and the lowest point on the surface of the conductive material layer is ≤20nm.

[0074] As an example of this embodiment, the material of the substrate may include a polymer. Further, the substrate may be a polyester film, a polyimide film, a polyvinylidene fluoride film, a polytetrafluoroethylene film, or a polypropylene film.

[0075] As an example of this embodiment, the height difference between the highest point and the lowest point on the substrate surface is ≥ 30nm. In some examples, the height difference between the highest point and the lowest point on the substrate surface can be 30nm~200nm. For example, the height difference between the highest point and the lowest point on the substrate surface can be 30nm, 40nm, 50nm, 60nm, 80nm, 100nm, 120nm, 150nm, 200nm, or the height difference between the highest point and the lowest point on the substrate surface can also be between any two of the above height differences.

[0076] As an example of this embodiment, the thickness of the substrate is 1 μm to 20 μm. In some examples, the thickness of the substrate can be 1 μm, 2 μm, 3 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 20 μm, or the thickness of the substrate can be between any two of the above thicknesses.

[0077] As an example of this embodiment, the material of the conductive material layer includes one or more of copper, aluminum, iron, and silver.

[0078] As an example of this embodiment, the thickness of the conductive material layer is 10 nm to 300 nm. For example, the thickness of the conductive material layer is 10 nm, 20 nm, 30 nm, 50 nm, 70 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, or the thickness of the conductive material layer may be between any two of the above thicknesses.

[0079] As an example of this embodiment, the height difference between the highest point and the lowest point on the surface of the conductive material layer is ≤ 20 nm. For example, the height difference between the highest point and the lowest point on the surface of the conductive material layer can be 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, or the height difference between the highest point and the lowest point on the surface of the conductive material layer can be between any two of the above height differences.

[0080] In a fifth aspect, the present disclosure further provides a battery, comprising a positive electrode plate and a negative electrode plate arranged opposite to each other, wherein the current collector in the positive electrode plate is the current collector of the above embodiment; and / or, the current collector in the negative electrode plate is the current collector of the above embodiment.

[0081] The present application is further described in detail below in conjunction with several specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0082] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0083] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0084] Example 1

[0085] A polyethylene terephthalate (PET) film having a thickness of 10 μm was provided as a substrate, and the maximum unevenness of its surface was measured to be 55 nm.

[0086] The substrate is placed on the conveyor roller of the dynamic magnetron sputtering coating equipment and sent into the sputtering chamber. In the sputtering chamber, a laser with an emission wavelength of 632nm and a corresponding optical lens group are arranged before the sputtering target, so that the laser can emit laser vertically toward the substrate. A detector array consisting of multiple scattered light detectors is arranged on both sides of the laser to detect the scattered light distribution of the laser. The scattered light distribution data is collected by computer and the concave area is simulated and generated.

[0087] A copper target is used as a sputtering target, and the substrate is transported at a speed of 5 cm / min to gradually pass through the sputtering area below the sputtering target. The deposition thickness is expected to be 100 nm. The laser emits laser to scan the surface of the substrate. When a concave area is detected and the substrate passes through the sputtering area in the concave area, the computer controls the substrate to stay for a while according to the size of the concave area.

[0088] After the deposition on the substrate is completed, the substrate is taken out. The thickness of the copper film is measured to be about 100 nm, and the maximum unevenness of the copper film surface is 32 nm.

[0089] Example 2

[0090] A polyethylene terephthalate (PET) film having a thickness of 10 μm was provided as a substrate, and the maximum unevenness of its surface was measured to be 55 nm.

[0091] The substrate is placed on the conveyor roller of the dynamic magnetron sputtering coating equipment and sent into the sputtering chamber. In the sputtering chamber, a laser with an emission wavelength of 632nm and a corresponding optical lens group are arranged before the sputtering target, so that the laser can emit laser vertically toward the substrate. A detector array consisting of multiple scattered light detectors is arranged on both sides of the laser to detect the scattered light distribution of the laser. The scattered light distribution data is collected by computer and the concave area is simulated and generated.

[0092] A copper target is used as a sputtering target, and the substrate is transported at a speed of 5 cm / min to gradually pass through the sputtering area below the sputtering target. The deposition thickness is expected to be 100 nm. The laser emits a laser to scan the surface of the substrate. When a concave area is detected and the concave area passes through the sputtering area, the computer controls the magnetic field strength and direction in the magnetron sputtering chamber to guide the target toward the concave area for sputtering.

[0093] After the deposition on the substrate is completed, the substrate is taken out. The thickness of the copper film is measured to be about 100 nm, and the maximum unevenness of the copper film surface is 15 nm.

[0094] Comparative Example 1

[0095] A polyethylene terephthalate (PET) film having a thickness of 10 μm was provided as a substrate, and the maximum unevenness of its surface was measured to be 55 nm.

[0096] The substrate is placed on a conveying roller of a dynamic magnetron sputtering coating device and transported into a sputtering chamber.

[0097] A copper target is used as the sputtering target, and the substrate is transported at a speed of 5 cm / min to gradually pass through the sputtering area below the sputtering target. The deposition thickness is expected to be 100 nm.

[0098] After the deposition on the substrate is completed, the substrate is taken out. The thickness of the copper film is measured to be about 100 nm, and the maximum unevenness of the copper film surface is 50 nm.

[0099] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A magnetron sputtering coating method, characterized in that: The steps include: Placing a substrate in a sputtering chamber, controlling the movement of the substrate and gradually passing the substrate through a sputtering region; The substrate before reaching the sputtering area is monitored to determine whether there is a recessed area. When it is detected that there is a recessed area on the surface of the substrate, the amount of material sputtered at the recessed area is increased.

2. The magnetron sputtering coating method according to claim 1, characterized in that: The step of monitoring whether the substrate has a recessed area comprises: The substrate is irradiated with laser light and scattered light of the laser light is monitored, and changes in the scattered light are used to monitor whether a concave area exists in the substrate.

3. The magnetron sputtering coating method according to claim 2, characterized in that: The spot size of the laser is 1 μm to 100 μm; and / or, The wavelength of the laser is 450nm~1200nm.

4. The magnetron sputtering coating method according to any one of claims 1 to 3, characterized in that: The step of increasing the amount of material sputtering in the recessed area comprises: By reducing the moving speed of the substrate or making the recessed area of ​​the substrate stay under the sputtering area, the sputtering amount of the material in the recessed area is increased; and / or, The sputtering direction of the target material is guided by adjusting the magnetic field to increase the amount of material sputtered in the recessed area.

5. A magnetron sputtering coating device, characterized in that: The magnetron sputtering coating equipment comprises: a sputtering chamber, a transportation mechanism, a flatness monitoring mechanism and a control mechanism; The transport mechanism and the flatness monitoring mechanism are arranged in the sputtering chamber, the transport mechanism is used to transport the substrate to be coated, the moving path of the transport mechanism passes through the sputtering area of ​​the sputtering chamber, the flatness monitoring mechanism is arranged before the sputtering area, the flatness monitoring mechanism is used to monitor whether there is a recessed area on the substrate before reaching the sputtering area, the control mechanism signal is connected to the flatness monitoring mechanism, and the control mechanism is used to control the magnetic field and / or control the transport speed of the transport mechanism according to the monitoring result of the flatness monitoring mechanism.

6. The magnetron sputtering coating equipment according to claim 5, characterized in that: The flatness monitoring mechanism comprises a laser source and a scattered light detector. The irradiation direction of the laser source is toward the moving path of the transport mechanism. The scattered light detector is arranged on the scattering path of the laser source and obtains the intensity of the scattered light.

7. A method for preparing a current collector, characterized in that: The method comprises the following steps: sputtering and depositing a conductive material layer on a substrate using the magnetron sputtering coating method as described in any one of claims 1 to 5.

8. A current collector, characterized in that: The current collector is prepared by the method for preparing the current collector according to claim 7, wherein the height difference between the highest point and the lowest point on the surface of the conductive material layer is ≤20 nm.

9. The current collector according to claim 8, characterized in that: The substrate is a polymer film, and the thickness of the substrate is 1 μm to 20 μm; and / or, The conductive material layer may be made of one or more of copper, aluminum, iron and silver.

10. A battery, characterized in that: It comprises a positive electrode sheet and a negative electrode sheet arranged opposite to each other, wherein the current collector in the positive electrode sheet is the current collector as claimed in claim 8 or 9; and / or, the current collector in the negative electrode sheet is the current collector as claimed in claim 8 or 9.

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