Apparatus and method for controlling the thickness of a flexible film coating using ion beam etching
By integrating ion beam etching technology into the roll-to-roll coating process, the coating is thinned using ion beam etching, which solves the problem of uneven coating thickness, improves product yield, and reduces production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ADVANCED MATERIALS TECH (BEIJING) CO LTD
- Filing Date
- 2024-12-30
- Publication Date
- 2026-06-30
AI Technical Summary
In existing roll-to-roll coating equipment, uneven or excessive metal coating thickness occurs during production, leading to product defects, increased resource waste and production costs. Furthermore, existing technologies have failed to effectively address the issue of coating thickness adjustment and control.
Ion beam etching technology is integrated into roll-to-roll coating process. An online thickness detection unit is set at the back end of the coating unit through the ion beam etching unit. The coating is thinned by ion beam etching to achieve precise control of coating thickness. Ions are generated by glow discharge principle and physically bombarded by electric field acceleration to achieve coating thinning.
It improves the uniformity of coating thickness and product yield, reduces production costs, achieves a product yield of over 98%, and simplifies the operation process.
Smart Images
Figure CN122303823A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of film deposition and etching technology, and relates to an apparatus and method for controlling the thickness of flexible thin film coatings using ion beam etching. Background Technology
[0002] In recent years, with the increasing demand for renewable energy, the development of energy storage technology has become increasingly urgent. Lithium-ion batteries, as an important type of battery product, have advantages such as high energy density, high charging efficiency, and environmental friendliness, and are widely used in many fields. Current collectors are a crucial component of lithium-ion batteries. Besides traditional metal foils, they also include composite current collectors composed of polymer substrates and metal coatings. The preparation of composite current collectors involves roll-to-roll coating processes for flexible thin film materials, where the uniformity and thickness control of the metal coating are key quality indicators.
[0003] Roll-to-roll coating technology is a continuous thin-film deposition process that uniformly forms a coating on a flexible substrate. The uniformity of the coating thickness is a crucial factor affecting the mechanical properties of composite current collectors, ensuring their adaptation to the battery manufacturing process and maintaining the consistency and stability of the battery's electrical performance. Traditional roll-to-roll coating equipment sometimes results in metal coating thickness exceeding specifications or uneven film thickness during production due to process fluctuations or equipment limitations, leading to product defects. Currently, the common practice for defective coated products is to discard them, which not only wastes resources but also increases production costs.
[0004] CN 114361608A discloses an apparatus and method for continuous roll-to-roll production of lithium-ion battery current collectors. The apparatus includes a pretreatment chamber, a drying chamber, a plasma cleaning chamber, a magnetron sputtering coating chamber, an active material coating chamber, and a vacuum heating chamber connected in series. The method includes: after unwinding, performing pretreatment on the substrate sequentially, followed by drying; performing plasma cleaning on the substrate to obtain a clean substrate; performing magnetron sputtering coating on the substrate to deposit a conductive and / or corrosion-resistant coating on the substrate surface; uniformly coating the coating surface of the substrate with an active material; heating and drying the substrate in a vacuum environment to solidify the surface active material; and rewinding to obtain the lithium-ion battery current collector. This apparatus and method focus on the coating and plating process of the battery current collector, but does not cover the steps for adjusting and controlling the coating thickness, making it impossible to determine the necessary process operations, which is detrimental to improving the product yield.
[0005] CN 116904955A discloses an ion beam assisted deposition coating apparatus and method. The apparatus includes a source system, a coating system, and an etching system. The coating system includes an ion source, an evaporation source, a laser source, or an electron beam; the etching system includes an ion source; a vacuum system provides a vacuum environment; a tape transport system unwinds and winds the tape; and a control system, under which the tape transport system unwinds and winds the tape, the coating system coats the tape in the vacuum environment, and / or the etching system etches the tape in the vacuum environment. In this apparatus and method, the tape in the etching area is simultaneously etched and coated, and then coated in the coating area. The etching area is located in the front passage of the coating area; that is, the etching occurs before the coating operation. The purpose of etching is not to adjust the coating thickness; it is a different process from coating thickness adjustment, and the corresponding etching method and process parameter selection are unrelated.
[0006] In summary, to adjust and control the coating thickness after current collector coating, ion beam etching is required to thin the coating to ensure uniform coating thickness, improve product yield, and facilitate subsequent use in lithium-ion batteries. Summary of the Invention
[0007] To address the problems existing in the prior art, the present invention aims to provide an apparatus and method for controlling the thickness of flexible thin film coatings using ion beam etching. By integrating ion beam etching technology into roll-to-roll coating processes, the thickness of the coating on the flexible thin film can be precisely controlled through the selection of ion beam etching and its parameters, thereby improving the uniformity of coating thickness and the quality of coated products, thus increasing product yield, reducing scrap, and lowering production costs.
[0008] To achieve this objective, the present invention adopts the following technical solution:
[0009] On one hand, the present invention provides an apparatus for controlling the thickness of a flexible thin film coating using ion beam etching. The apparatus includes a coating unit, an online thickness detection unit, an ion beam etching unit, and a control unit. The coating unit, the online thickness detection unit, and the ion beam etching unit are connected in sequence. The control unit is connected to the coating unit, the online thickness detection unit, and the ion beam etching unit. The ion beam etching unit includes an ion source, an accelerating electrode, and a stage. The flexible thin film passes through the coating unit, the online thickness detection unit, and the ion beam etching unit in sequence. The coated flexible thin film is etched between the accelerating electrode and the stage in the ion beam etching unit.
[0010] In this invention, for roll-to-roll coating processes of flexible thin films, to achieve control over the coating thickness and uniformity, ion beam etching technology is integrated into the roll-to-roll coating process. This is achieved by placing the ion beam etching unit at the rear end of the coating unit and placing an online thickness detection unit between them to determine whether thinning treatment is required in the ion beam etching unit. Through specific selection of the ion beam etching unit structure, ions are generated using the glow discharge principle, accelerated by an electric field, and then physically bombarded to sputter the coating atoms, achieving the purpose of coating thinning, improving the uniformity of film thickness, and increasing product yield. The device has a simple structure, is easy to operate, has low production costs, and is widely applicable.
[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.
[0012] As a preferred embodiment of the present invention, the device further includes an unwinding unit and a winding unit, wherein the unwinding unit is located in front of the coating unit and the winding unit is located behind the ion beam etching unit.
[0013] Preferably, after the unwinding unit releases the flexible film, it passes sequentially through the coating unit, the online thickness detection unit, and the ion beam etching unit, and is then wound up by the winding unit.
[0014] Preferably, the unwinding unit and the rewinding unit independently include a spool, a rotating shaft, and a motor.
[0015] As a preferred technical solution of the present invention, the coating unit includes a coating chamber, and the main structure in the coating chamber includes a coating roller.
[0016] Preferably, the online thickness detection unit includes an online areal density detection device or an online sheet resistance detection device.
[0017] Preferably, the online areal density detection device or the online sheet resistance detection device independently includes a sensor.
[0018] In this invention, online areal density detection or online sheet resistance detection can both reflect the thickness of the coating. The data obtained by the sensor is the online sheet resistance value or areal density value. The sensor data is fed back to the processor of the control unit to obtain the coating thickness value. The difference between the value and the target set value is judged to determine whether thinning treatment is required.
[0019] Preferably, the ion source in the ion beam etching unit includes plasma, a filament, and an electrode plate. The ions generated by the ion source are accelerated by an accelerating electrode to bombard the coating on the flexible thin film.
[0020] Preferably, the ion beam etching unit further includes a neutralizer located between the accelerating electrode and the stage.
[0021] In this invention, the neutralizer is used to emit electrons into the positively charged ion beam drawn from the ion source, thereby neutralizing the beam current and beam charge, preventing excessive charge accumulation on the target material or processing surface, preventing the potential changes caused by charge accumulation from affecting the stability and uniformity of the etching process, and also protecting the etched material and equipment from damage caused by charge accumulation.
[0022] Preferably, the ion beam etching unit further includes a cooling assembly located on one side of the worktable, and the medium of the cooling assembly includes liquid nitrogen or cooling water.
[0023] As a preferred technical solution of the present invention, the control unit is divided into multiple modules, which control the operation of each structural unit respectively.
[0024] Preferably, the control unit includes a processor, and the sensor data in the online thickness detection unit is fed back to the processor. The calculated thickness value is compared with the target value, and the operation of the ion beam etching unit is controlled.
[0025] Preferably, the control unit controls the operation of the ion beam etching unit and sets and adjusts the working parameters of the ion beam etching.
[0026] On the other hand, the present invention provides a method for controlling the thickness of a flexible thin film coating using the above-described device, the method comprising the following steps:
[0027] (1) After unwinding the flexible film, a metal coating is obtained, and the thickness of the metal coating is measured.
[0028] (2) Ion beam etching is performed on the metal coating with a thickness exceeding the set value in step (1) until the target thickness is achieved.
[0029] As a preferred technical solution of the present invention, the flexible film in step (1) includes an organic polymer substrate with a thickness of 2 to 100 μm, such as 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 20 μm, 30 μm, 50 μm, 75 μm or 100 μm, but is not limited to the listed values. Other unlisted values within this range are also applicable, preferably 6 to 15 μm.
[0030] Preferably, the organic polymer substrate comprises any one or a combination of at least two of polyethylene terephthalate (PET), polyimide (PI), or polypropylene (PP). Typical but not limited combinations include: a combination of polyethylene terephthalate and polyimide, a combination of polyimide and polypropylene, a combination of polyethylene terephthalate, polyimide, and polypropylene, etc.
[0031] In this invention, one of the important uses of the flexible thin film surface coating is as a composite current collector. As an important component of lithium-ion batteries, controlling the uniformity of the thin film coating thickness helps control the mechanical properties of the current collector, such as tensile strength and elongation, to adapt to operations such as winding and stacking during battery manufacturing. It also helps ensure the consistency of battery electrical performance, ensuring the performance matching of each battery cell in the battery pack and avoiding performance stability problems caused by inconsistent internal resistance. If the thickness is uneven, the thickness difference will be amplified after stacking, affecting puncture safety. Furthermore, it helps simplify the battery manufacturing process and improve production efficiency and product quality stability.
[0032] Preferably, the unwinding in step (1) involves releasing the flexible film from the roll of the unwinding unit and allowing it to enter the coating unit for coating.
[0033] As a preferred technical solution of the present invention, the coating method in step (1) is sputtering coating or evaporation coating.
[0034] Preferably, the material of the metal coating in step (1) includes aluminum or copper.
[0035] Preferably, the thickness of the metal coating in step (1) is 900 to 1100 nm, such as 900 nm, 920 nm, 950 nm, 980 nm, 1000 nm, 1020 nm, 1050 nm, 1080 nm or 1100 nm, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0036] As a preferred technical solution of the present invention, the thickness detection in step (1) adopts online sheet resistance detection or online surface density detection. The sensor obtains the detection data and feeds it back to the processor to obtain the thickness data.
[0037] Preferably, if the detected thickness data exceeds the set value by more than 5%, such as 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15%, then a thinning process is required, which is ion beam etching.
[0038] As a preferred technical solution of the present invention, during the ion beam etching in step (2), the unwinding speed of the flexible film is 1 to 50 m / min, for example, 1 m / min, 5 m / min, 10 m / min, 15 m / min, 20 m / min, 25 m / min, 30 m / min, 40 m / min or 50 m / min, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0039] Preferably, during the ion beam etching, an inert gas is introduced into the ion source, and inert gas ions are generated by glow discharge. After being accelerated by the accelerating electrode, they bombard the metal coating, causing the metal coating atoms to sputter and reducing the thickness of the metal coating.
[0040] Preferably, the inert gas flow rate is 20 to 50 sccm, such as 20 sccm, 25 sccm, 30 sccm, 35 sccm, 40 sccm, 45 sccm or 50 sccm, but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0041] Preferably, the inert gas includes argon, neon, or helium, with argon being the most commonly used.
[0042] Preferably, the energy of the ion beam during ion beam etching is 300 to 1000 eV, such as 300 eV, 400 eV, 500 eV, 600 eV, 700 eV, 800 eV, 900 eV or 1000 eV, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0043] Preferably, the beam current density of the ion beam etching is 0.1–200 mA / cm². 2 For example, 0.1 mA / cm 2 0.5mA / cm 2 1mA / cm 2 5mA / cm 2 10mA / cm 2 30mA / cm 2 50mA / cm 2 80mA / cm 2 100mA / cm 2 150mA / cm 2 Or 200mA / cm 2 The values are not limited to those listed; other unlisted values within this range also apply, with a preferred value of 10–200 mA / cm. 2 .
[0044] In this invention, the process parameters of the ion beam etching are selected based on the initial thickness and target thickness of the metal coating. The energy of the electron beam is dynamically adjusted according to the change in film thickness information. Initially, when the coating thickness deviates significantly from the target thickness, the electron beam energy value is high; otherwise, the coating thickness may not reach the target value after thinning. The electron beam energy also changes continuously based on the coating thickness changes detected online. If the beam current density is too low, the coating thickness may not reach the target value after thinning when the vehicle speed is consistent. If the beam current density is too high, it may cause over-etching, resulting in a coating thickness lower than the target value.
[0045] As a preferred technical solution of the present invention, the ion beam etching in step (2) ends when the thickness of the metal coating is reduced to the set value, and the deviation value does not exceed ±2%, such as -2%, -1.5%, -1%, -0.5%, 0%, 0.5%, 1%, 1.5%, or 2%, etc., but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0046] Preferably, in the ion beam etching process described in step (2), a cooling medium is used to control the temperature of the metal coating.
[0047] Preferably, the cooling medium includes liquid nitrogen or cooling water.
[0048] In this invention, since heat is generated during the ion beam etching process, the flexible film and coating need to be cooled to prevent overheating from affecting the quality of the coating.
[0049] Preferably, after the ion beam etching in step (2) is completed, quality inspection is performed.
[0050] In this invention, after the ion beam etching is completed, a thickness detection device can be used again to perform a final quality inspection on the thinned coating layer to ensure that it meets the product specifications. According to the structure of the composite current collector, there are metal coatings on both sides. If the coating equipment can perform coating on both sides at the same time, the online detection device can detect both sides at the same time. If only single-sided coating is possible, the above steps need to be performed again.
[0051] Compared with the prior art, the present invention has the following beneficial effects:
[0052] (1) The present invention integrates ion beam etching technology into roll-to-roll coating process, sets the ion beam etching unit at the rear end of the coating unit, and sets an online thickness detection unit between the two to determine whether thinning treatment is performed in the ion beam etching unit.
[0053] (2) By selecting the specific structure of the ion beam etching unit and the ion beam etching parameters, the present invention generates ions using the glow discharge principle, which are accelerated by an electric field and physically bombard the coating to sputter the coating atoms, thereby achieving the purpose of thinning the coating, improving the uniformity of the film thickness and the product yield, and the product yield can reach more than 98%.
[0054] (3) The device described in this invention has a simple structure, is easy to operate, can reduce product scrap, reduce production costs, and has a wide range of applications. Attached Figure Description
[0055] Figure 1 This is a schematic diagram of the device for controlling the thickness of flexible thin film coating by ion beam etching provided in Embodiment 1 of the present invention;
[0056] Figure 2 This is a schematic diagram of the structure of the ion beam etching unit provided in Embodiment 1 of the present invention;
[0057] Among them, 1-unwinding unit, 2-coating unit, 3-online thickness detection unit, 4-ion beam etching unit, 41-filament, 42-electrode plate, 43-accelerating electrode, 44-neutralizer, and 5-rewinding unit. Detailed Implementation
[0058] To better illustrate the present invention and facilitate understanding of its technical solutions, the present invention is further described in detail below. However, the following embodiments are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.
[0059] The following are typical but non-limiting embodiments of the present invention:
[0060] Example 1:
[0061] This embodiment provides a device for controlling the thickness of flexible thin film coatings using ion beam etching. A schematic diagram of the device is shown below. Figure 1 As shown, the system includes a coating unit 2, an online thickness detection unit 3, an ion beam etching unit 4, and a control unit. The coating unit 2, online thickness detection unit 3, and ion beam etching unit 4 are connected in sequence. The control unit is connected to all three units. A schematic diagram of the ion beam etching unit 4 is shown below. Figure 2 As shown, it includes an ion source, an accelerating electrode 43, and a stage; the flexible film passes sequentially through the coating unit 2, the online thickness detection unit 3, and the ion beam etching unit 4, and the coated flexible film is etched between the accelerating electrode and the stage in the ion beam etching unit.
[0062] The device also includes an unwinding unit 1 and a winding unit 5. The unwinding unit 1 is located in front of the coating unit 2, and the winding unit 5 is located behind the ion beam etching unit 4.
[0063] After the unwinding unit 1 releases the flexible film, it passes sequentially through the coating unit 2, the online thickness detection unit 3, and the ion beam etching unit 4, and is then wound up by the winding unit 5.
[0064] Both the unwinding unit 1 and the winding unit 5 include a roller, a rotating shaft, and a motor.
[0065] The coating unit 2 includes a coating chamber, and the main structure in the coating chamber includes a coating roller.
[0066] The online thickness detection unit 2 is an online sheet resistance detection device, which is a sensor that obtains the online sheet resistance value.
[0067] The ion source in the ion beam etching unit 4 includes plasma, filament 41 and electrode plate 42. The ions generated by the ion source are accelerated by the accelerating electrode 43 and bombard the coating on the flexible thin film.
[0068] The ion beam etching unit 4 also includes a neutralizer 44, which is located between the accelerating electrode 43 and the stage.
[0069] The ion beam etching unit 4 also includes a cooling component, which is located on one side of the worktable, and the medium of the cooling component is cooling water.
[0070] The control unit is divided into multiple modules, each controlling the operation of a different structural unit.
[0071] The control unit includes a processor. Sensor data from the online thickness detection unit 3 is fed back to the processor. The calculated thickness value is compared with the target value, and the operation of the ion beam etching unit 4 is controlled.
[0072] The control unit controls the operation of the ion beam etching unit 4, and sets and adjusts the working parameters of the ion beam etching.
[0073] Example 2:
[0074] This embodiment provides a device for controlling the thickness of a flexible thin film coating using ion beam etching. The device includes a coating unit 2, an online thickness detection unit 3, an ion beam etching unit 4, and a control unit. The coating unit 2, online thickness detection unit 3, and ion beam etching unit 4 are connected in sequence. The control unit is connected to the coating unit 2, online thickness detection unit 3, and ion beam etching unit 4. The ion beam etching unit 4 includes an ion source, an accelerating electrode 43, and a stage. The flexible thin film passes through the coating unit 2, online thickness detection unit 3, and ion beam etching unit 4 in sequence. The coated flexible thin film is etched between the accelerating electrode and the stage in the ion beam etching unit.
[0075] The device also includes an unwinding unit 1 and a winding unit 5. The unwinding unit 1 is located in front of the coating unit 2, and the winding unit 5 is located behind the ion beam etching unit 4.
[0076] After the unwinding unit 1 releases the flexible film, it passes sequentially through the coating unit 2, the online thickness detection unit 3, and the ion beam etching unit 4, and is then wound up by the winding unit 5.
[0077] Both the unwinding unit 1 and the winding unit 5 include a roller, a rotating shaft, and a motor.
[0078] The coating unit 2 includes a coating chamber, and the main structure in the coating chamber includes a coating roller.
[0079] The online thickness detection unit 2 is an online surface density detection device, which is a sensor that obtains the surface density value.
[0080] The ion source in the ion beam etching unit 4 includes plasma, filament 41 and electrode plate 42. The ions generated by the ion source are accelerated by the accelerating electrode 43 and bombard the coating on the flexible thin film.
[0081] The ion beam etching unit 4 also includes a neutralizer 44, which is located between the accelerating electrode 43 and the stage.
[0082] The ion beam etching unit 4 also includes a cooling component located on one side of the worktable, and the medium of the cooling component is liquid nitrogen.
[0083] The control unit is divided into multiple modules, each controlling the operation of a different structural unit.
[0084] The control unit includes a processor. Sensor data from the online thickness detection unit 3 is fed back to the processor. The calculated thickness value is compared with the target value, and the operation of the ion beam etching unit 4 is controlled.
[0085] The control unit controls the operation of the ion beam etching unit 4, and sets and adjusts the working parameters of the ion beam etching.
[0086] Example 3:
[0087] This embodiment provides a method for controlling the thickness of a flexible thin film coating using ion beam etching. The method is performed using the apparatus described in Embodiment 1 and includes the following steps:
[0088] (1) After the flexible film is released from the unwinding unit, it enters the coating unit for coating. The flexible film is a polyethylene terephthalate substrate with a thickness of 15 μm. The coating method is sputtering coating to obtain a metal coating. The metal coating is an aluminum coating. The thickness of the metal coating is detected by online sheet resistance detection. The data obtained by the sensor is fed back to the processor to obtain the thickness data. The thickness of the metal coating is 1100 nm. The proportion of the thickness exceeding the target thickness of 1000 nm is 10%, and it needs to be thinned.
[0089] (2) The metal coating with a thickness exceeding the set value in step (1) is subjected to ion beam etching. During ion beam etching, argon gas is introduced into the ion source, and argon ions are generated by glow discharge. After being accelerated by the accelerating electrode, they bombard the metal coating, causing sputtering of the metal coating atoms and reducing the thickness of the metal coating. The unwinding speed of the flexible film is 20 m / min, the argon gas flow rate is 30 sccm, the energy of the ion beam varies in the range of 500 to 700 eV, and the beam current density is 50 mA / cm. 2 The etching process continues until the thickness of the metal coating reaches within ±1% of the target thickness. During the ion beam etching process, cooling water is used to control the temperature of the metal coating. After the ion beam etching is completed, a quality inspection is performed, and the thickness of the metal coating meets the product specifications.
[0090] Example 4:
[0091] This embodiment provides a method for controlling the thickness of a flexible thin film coating using ion beam etching. The method is performed using the apparatus in Embodiment 2 and includes the following steps:
[0092] (1) After the flexible film is released from the unwinding unit, it enters the coating unit for coating. The flexible film is a polyimide substrate with a thickness of 50 μm. The coating method is sputtering coating to obtain a metal coating. The metal coating is an aluminum coating. The thickness of the metal coating is detected by online surface density detection. The data obtained by the sensor is fed back to the processor to obtain the thickness data. The thickness of the metal coating is 1150 nm, which exceeds the target thickness of 1000 nm by 15%, and needs to be thinned.
[0093] (2) The metal coating with a thickness exceeding the set value in step (1) is subjected to ion beam etching. During ion beam etching, argon gas is introduced into the ion source, and argon ions are generated by glow discharge. After being accelerated by the accelerating electrode, they bombard the metal coating, causing sputtering of the metal coating atoms and reducing the thickness of the metal coating. The unwinding speed of the flexible film is 10 m / min, the argon gas flow rate is 50 sccm, the energy of the ion beam varies in the range of 800 to 1000 eV, and the beam current density is 100 mA / cm. 2 The etching process continues until the metal coating thickness reaches within ±1.5% of the target thickness. During the ion beam etching process, liquid nitrogen is used to control the temperature of the metal coating. After the ion beam etching is completed, a quality inspection is performed, and the thickness of the metal coating meets the product specifications.
[0094] Example 5:
[0095] This embodiment provides a method for controlling the thickness of a flexible thin film coating using ion beam etching. The method is performed using the apparatus described in Embodiment 1 and includes the following steps:
[0096] (1) After the flexible film is released from the unwinding unit, it enters the coating unit for coating. The flexible film is a polypropylene substrate with a thickness of 5 μm. The coating method is evaporation coating to obtain a metal coating. The metal coating is an aluminum coating. The thickness of the metal coating is detected by online sheet resistance detection. The data obtained by the sensor is fed back to the processor to obtain the thickness data. The thickness of the metal coating is 980 nm. The proportion of the thickness exceeding the target thickness of 900 nm is 8.9%, and thinning treatment is required.
[0097] (2) The metal coating with a thickness exceeding the set value in step (1) is subjected to ion beam etching. During ion beam etching, argon gas is introduced into the ion source, and argon ions are generated by glow discharge. After being accelerated by the accelerating electrode, they bombard the metal coating, causing sputtering of the metal coating atoms and reducing the thickness of the metal coating. The unwinding speed of the flexible film is 40 m / min, the argon gas flow rate is 20 sccm, the energy of the ion beam varies in the range of 400 to 600 eV, and the beam current density is 20 mA / cm. 2 The etching process continues until the metal coating thickness reaches within ±0.5% of the target thickness. During the ion beam etching process, cooling water is used to control the temperature of the metal coating. After the ion beam etching is completed, a quality inspection is performed, and the metal coating thickness meets the product specifications.
[0098] Example 6:
[0099] This embodiment provides a method for controlling the thickness of a flexible thin film coating using ion beam etching. The method is performed using the apparatus described in Embodiment 1 and includes the following steps:
[0100] (1) After the flexible film is released from the unwinding unit, it enters the coating unit for coating. The flexible film is a polyethylene terephthalate substrate with a thickness of 10 μm. The coating method is sputtering coating to obtain a metal coating. The metal coating is a copper coating. The thickness of the metal coating is detected by online sheet resistance detection. The data obtained by the sensor is fed back to the processor to obtain the thickness data. The thickness of the metal coating is 1075 nm, which exceeds the target thickness of 1000 nm by 7.5%, and thinning treatment is required.
[0101] (2) The metal coating with a thickness exceeding the set value in step (1) is subjected to ion beam etching. During ion beam etching, argon gas is introduced into the ion source, and argon ions are generated by glow discharge. After being accelerated by the accelerating electrode, they bombard the metal coating, causing sputtering of the metal coating atoms and reducing the thickness of the metal coating. The unwinding speed of the flexible film is 30 m / min, the argon gas flow rate is 25 sccm, the energy of the ion beam varies in the range of 600 to 800 eV, and the beam current density is 150 mA / cm. 2 The etching process continues until the metal coating thickness reaches within ±1.2% of the target thickness. During the ion beam etching process, cooling water is used to control the temperature of the metal coating. After the ion beam etching is completed, a quality inspection is performed, and the thickness of the metal coating meets the product specifications.
[0102] Comparative Example 1:
[0103] This comparative example provides an apparatus and method for controlling the thickness of a flexible thin film coating using ion beam etching. The apparatus is the same as that in Example 1, except that it does not include the ion beam etching unit 4.
[0104] The method described herein is the same as that in Example 3, except that the operation in step (2) is not included.
[0105] The flexible films with metal coatings obtained in Examples 3-5 and Comparative Example 1 were used as composite current collectors for lithium-ion batteries. The films were coated on the surface of the batteries and then processed through a series of battery manufacturing processes, such as rolling, slitting, die-cutting, baking, stacking, welding, encapsulation, electrolyte injection, and formation, to prepare soft-pack batteries with a capacity of about 1.5 Ah. The batteries were subjected to cycle performance tests and rate performance tests, and the test results are shown in Table 1.
[0106] Table 1
[0107]
[0108]
[0109] As shown in Table 1, the metal coatings in Examples 3-5 were etched by ion beam, resulting in uniform metal coating thickness. When used in lithium-ion batteries, the thermal and electrical conductivity of the electrodes was more uniform, leading to better performance. In contrast, Comparative Example 1 did not undergo ion beam etching, and the uneven coating thickness easily resulted in poor uniformity of the cell's internal resistance, affecting cycle performance. The capacity retention rate of the lithium-ion batteries prepared with the metal coatings in the examples after 500 cycles was about 1-2% higher than that in Comparative Example 1, and the rate performance was about 3-4% higher.
[0110] Based on the above embodiments and comparative examples, it can be concluded that the present invention integrates ion beam etching technology into a roll-to-roll coating process, sets the ion beam etching unit at the rear end of the coating unit, and sets an online thickness detection unit between them to determine whether thinning treatment is performed in the ion beam etching unit. By specifically selecting the structure of the ion beam etching unit and the ion beam etching parameters, ions are generated using the glow discharge principle, accelerated by an electric field, and physically bombarded on the coating, causing the coating atoms to sputter, thereby achieving the purpose of coating thinning, improving the uniformity of film thickness and product yield, with a product yield of over 98%. The device has a simple structure, is easy to operate, can reduce product scrap, lower production costs, and has a wide range of applications.
[0111] The applicant declares that the present invention is illustrated through the above embodiments with detailed apparatus and methods, but the present invention is not limited to the above detailed apparatus and methods, that is, it does not mean that the present invention must rely on the above detailed apparatus and methods to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the apparatus of the present invention, additions of auxiliary devices, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
Claims
1. A device for controlling the thickness of a flexible thin film coating using ion beam etching, characterized in that, The device includes a coating unit, an online thickness detection unit, an ion beam etching unit, and a control unit. The coating unit, online thickness detection unit, and ion beam etching unit are connected in sequence. The control unit is connected to the coating unit, online thickness detection unit, and ion beam etching unit. The ion beam etching unit includes an ion source, an accelerating electrode, and a stage. The flexible film passes through the coating unit, online thickness detection unit, and ion beam etching unit in sequence. The coated flexible film is etched between the accelerating electrode and the stage in the ion beam etching unit.
2. The apparatus according to claim 1, characterized in that, The device further includes an unwinding unit and a winding unit, wherein the unwinding unit is located in front of the coating unit and the winding unit is located behind the ion beam etching unit; Preferably, after the unwinding unit releases the flexible film, it passes sequentially through the coating unit, the online thickness detection unit, and the ion beam etching unit, and is then wound up by the winding unit. Preferably, the unwinding unit and the rewinding unit independently include a spool, a rotating shaft, and a motor.
3. The apparatus according to claim 1 or 2, characterized in that, The coating unit includes a coating chamber, and the main structure in the coating chamber includes a coating roller; Preferably, the online thickness detection unit includes an online areal density detection device or an online sheet resistance detection device; Preferably, the online areal density detection device or the online sheet resistance detection device independently includes a sensor; Preferably, the ion source in the ion beam etching unit includes plasma, a filament, and an electrode plate. The ions generated by the ion source are accelerated by an accelerating electrode to bombard the coating on the flexible thin film. Preferably, the ion beam etching unit further includes a neutralizer located between the accelerating electrode and the stage; Preferably, the ion beam etching unit further includes a cooling assembly located on one side of the worktable, and the medium of the cooling assembly includes liquid nitrogen or cooling water.
4. The apparatus according to any one of claims 1-3, characterized in that, The control unit is divided into multiple modules, each controlling the operation of a different structural unit. Preferably, the control unit includes a processor, and the sensor data in the online thickness detection unit is fed back to the processor, the calculated thickness value is compared with the target value, and the operation of the ion beam etching unit is controlled. Preferably, the control unit controls the operation of the ion beam etching unit and sets and adjusts the working parameters of the ion beam etching.
5. The method for controlling the thickness of a flexible thin film coating according to any one of claims 1-4, characterized in that, The method includes the following steps: (1) After unwinding the flexible film, a metal coating is obtained, and the thickness of the metal coating is measured. (2) Ion beam etching is performed on the metal coating with a thickness exceeding the set value in step (1) until the target thickness is achieved.
6. The method according to claim 5, characterized in that, The flexible film in step (1) includes an organic polymer substrate with a thickness of 2 to 100 μm, preferably 6 to 15 μm; Preferably, the organic polymer substrate comprises any one or a combination of at least two of polyethylene terephthalate, polyimide, or polypropylene; Preferably, the unwinding in step (1) involves releasing the flexible film from the roll of the unwinding unit and allowing it to enter the coating unit for coating.
7. The method according to claim 5 or 6, characterized in that, The coating method described in step (1) is sputtering coating or evaporation coating; Preferably, the material of the metal coating in step (1) includes aluminum or copper; Preferably, the thickness of the metal coating in step (1) is 900-1100 nm.
8. The method according to any one of claims 5-7, characterized in that, The thickness detection in step (1) adopts online sheet resistance detection or online surface density detection. The sensor obtains the detection data and feeds it back to the processor to obtain the thickness data. Preferably, if the detected thickness data exceeds the set value by more than 5%, a thinning process is required, which is ion beam etching.
9. The method according to any one of claims 5-8, characterized in that, During the ion beam etching in step (2), the unwinding speed of the flexible thin film is 1-50 m / min; Preferably, during the ion beam etching, an inert gas is introduced into the ion source, and inert gas ions are generated by glow discharge. After being accelerated by the accelerating electrode, they bombard the metal coating, causing the metal coating atoms to sputter and reducing the thickness of the metal coating. Preferably, the inert gas flow rate is 20–50 sccm; Preferably, the energy of the ion beam during ion beam etching is 300–1000 eV; Preferably, the beam current density of the ion beam etching is 0.1–200 mA / cm². 2 Preferably, it is 10–200 mA / cm 2 .
10. The method according to any one of claims 5-9, characterized in that, Step (2) ends when the ion beam etching reaches the set value and the thickness of the metal coating is reduced to the set value, and the deviation value does not exceed ±2%. Preferably, in the ion beam etching process described in step (2), a cooling medium is used to control the temperature of the metal coating; Preferably, the cooling medium includes liquid nitrogen or cooling water; Preferably, after the ion beam etching in step (2) is completed, quality inspection is performed.