Functional Coating Materials and Coating Systems for Slot Die Electrode Manufacturing in Future Mobility

Abstract

The present invention provides a coating system that forms a Cr-based buffer layer and a DLC coating layer as a top layer on a slot die, configures a slot die-specific jig capable of orbiting and rotating the slot die, arranges multiple ion sources and sputter sources at predetermined intervals to enable uniform coating along the length direction of the slot die, arranges multiple plasma discharge gas and / or coating material gas injectors at predetermined intervals, and monitors and controls the process state in real time.

Description

Technology Field

[0001] The present invention relates to a functional coating material for the surface of a slot die used in a future mobility electrode manufacturing process and a manufacturing system thereof. Background Technology

[0002] A slot die is a component that sprays coating material through a slot. It plays a critical role in the secondary battery manufacturing process as a spray nozzle mold component that sprays positive and / or negative electrode materials onto an Al thin plate during the taping and casting manufacturing process for secondary battery electrodes. To maximize wear resistance and corrosion resistance, the raw material of the slot die is processed, heat treatment is performed to improve durability and strength, and the surface is coated with a material possessing high hardness, wear resistance, and low friction. Conventionally, TiN coating has been applied to the surface of slot dies. Slot dies used for electrode manufacturing are approximately 1 meter in length and are heavy components, making it difficult to apply a uniform coating across their entire length. As slot dies are precision equipment designed for heavy weight, various types of defects occur due to mishandling during operations such as loading, unloading, and fastening during production. To solve these problems, it is necessary to apply a coating material with high hardness, wear resistance, and low friction; however, there is a problem in that the coating material is difficult to distribute uniformly across the entire length. Non-uniform coating causes film peeling and staining problems due to an increased coefficient of friction on the die surface. It also has a serious impact on the coating quality of the slot die and hinders its long-term use. Therefore, there is a need for technology capable of uniformly coating the entire slot die with a coating material that possesses high hardness, wear resistance, and low friction properties.

[0003] Registered Patent No. 10-1860082 describes a technology for reinforcing the coating bar portion of a slot die with one of TiN coating, TiC coating, Al2O3 coating, diamond coating, or DLC coating, but does not specifically describe a method for uniformly coating the entire length. The problem to be solved

[0004] The objective of the present invention is to provide a technology capable of uniformly coating a slot die with a coating material having high hardness, wear resistance, and low friction. means of solving the problem

[0005] In accordance with the above objective, the present invention provides a coating system that forms a Cr-based buffer layer and a DLC coating layer as a top layer on a slot die, configures a slot die-specific jig capable of orbiting and rotating the slot die, arranges multiple ion sources and sputter sources at predetermined intervals to enable uniform coating along the length direction of the slot die, arranges multiple plasma discharge gas and / or coating material gas inlets at predetermined intervals, and monitors and controls the process state in real time.

[0006] A jig dedicated to slot dies is,

[0007] A central axis for orbiting and a rotating plate provided at each end of the central axis;

[0008] A plurality of slot die fixing parts installed on the above-mentioned rotating plate and arranged radially with respect to the above-mentioned central axis;

[0009] A rotational part extending from the slot die fixing part and contacting the rotating plate, capable of rotating the slot die about the central axis of the slot die fixing part; and

[0010] A support capable of mounting the rotating plate on the lower part of the above rotating plate; including

[0011] The above-mentioned mounting bracket includes a bearing block including a bearing or a rotating rail including a rotating rail to enable rotational driving of the rotating plate.

[0012] In addition, the slot die jig is configured with a gear at the inner diameter side of the rotating plate and the contact portion with the rotating part for the rotation of the slot die.

[0013] In addition, to perform a uniform coating on the entire slot die that is horizontally arranged and rotated within the chamber, linear ion sources and sputter sources are arranged on the walls and ceiling of the chamber at predetermined intervals so as to surround the slot die, and the gas supply section of one sputter source is configured with a plurality of branches.

[0014] In the above, the linear ion source, the sputter source, and the gas supply unit are arranged with their lengths parallel to the direction in which the slot dies are arranged, and are configured to have a length greater than the total length of the slot dies.

[0015] In the above, the linear ion source includes a first and a second linear ion source, the sputter source includes a first and a second sputter source, and each sputter source includes two gas supply units.

[0016] In addition, the present invention utilizes the above coating system to perform plasma cleaning, form a Cr-based buffer layer, and form a DLC top layer on a slot die, and to this end, proceeds with the process as follows.

[0017] Initial vacuuming the chamber, and

[0018] A current of 200 to 1000 mA and a voltage of 800 to 2000 V are applied to the first linear ion source and the second linear ion source, and an inert gas is flowed at 80 to 200 sccm to discharge plasma, and a bias voltage of 100 to 800 V and a bias current of 0.5 to 1.5 A are applied to the slot die to perform plasma cleaning for 60 to 150 minutes, and

[0019] A Cr target is arranged in the first sputter source and the second sputter source, a current of 500 to 2500 mA and a voltage of 100 to 700 V are applied and an inert gas is flowed at 50 to 300 sccm to discharge the plasma, and a bias voltage of 50 to 250 V and a bias current of 0.1 to 1.0 A are applied to the slot die to form a Cr layer for 5 to 30 minutes, and thereafter, under the same conditions, an N2 gas is flowed at 5 to 50 sccm to form a CrN layer, and the formation of the CrN layer is repeated 3 times for 5 to 30 minutes each, and thereafter, under the same conditions, the N2 gas supply is stopped and a hydrocarbon gas is supplied at 5 to 30 sccm to form a CrC layer, thereby forming a Cr / CrN / CrC buffer layer.

[0020] A current of 200 to 1000 mA and a voltage of 800 to 2000 V are applied to a first linear ion source and a second linear ion source, and an inert gas is flowed at 80 to 200 sccm and a hydrocarbon gas at 100 to 300 sccm to discharge plasma, and a bias voltage of 100 to 600 V and a bias current of 0.5 to 1.5 A are applied to a slot die to form a DLC coating layer for 200 to 480 minutes.

[0021] In the above, the buffer layer formation process is controlled to a total of 60 minutes or less.

[0022] In the above, the vacuum level of the initial chamber is 6.3×10 -6 Up to 7.7×10 -6 Do Torr. Effects of the invention

[0023] According to the present invention, a high-hardness, wear-resistant, and low-friction coating layer is uniformly provided to a slot die that is long and heavy, thereby improving the durability of the slot die and improving the quality of the electrode manufactured by the slot die.

[0024] The slot die jig of the present invention is configured to load the slot die in a horizontal direction and allow it to rotate during the coating process, thereby forming a coating layer with a uniform distribution over the entire length of the slot die.

[0025] In addition, the coating system of the present invention arranges linear ion sources and sputter sources along the length direction of the slot die on the wall and ceiling surfaces of the chamber, and arranges them at predetermined intervals to form a shape that surrounds the slot die as a whole, thereby forming a uniform coating layer over the entire long slot die.

[0026] In addition, the lengths of the linear ion source and the sputter source are made longer than the slot die length to form a sufficient coating layer over the entire slot die.

[0027] According to the present invention, for the standard requirements of coating hardness of 1900 to 2000 Hv, coating bonding strength of 30 N or more, friction coefficient of less than 0.15, and coating thickness uniformity of 2.5 µm or less, a result of 2.23 ± 0.01 µm is shown. Brief explanation of the drawing

[0028] Figure 1 is a photograph of a slot die. FIG. 2 is a cross-sectional view of a slot die dedicated jig according to the present invention. FIG. 3 is a side cross-sectional view showing the configuration of the rotating plate, slot die fixing part, and mounting bracket of the slot die jig of the present invention. Figure 4 is a diagram explaining the principle by which a slot die can rotate in a slot die jig. Figure 5 is a photograph of the experimental results showing that the coating uniformity was improved due to the presence of the slot die jig. Figure 6 is a schematic diagram of plasma cleaning. Figure 7 is a diagram showing the adhesion force and friction coefficient measurements exhibited by the coating layer of the present invention. Figure 8 is a photograph showing the thickness uniformity of the coating layer of the present invention. Specific details for implementing the invention

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0030] Figure 1 is a photograph of a slot die.

[0031] The coating material injection section of the slot die specifically requires high hardness, wear resistance, and low friction characteristics. However, forming a coating layer on the entire surface of the slot die, rather than coating only a portion, can be more stable and help improve lifespan.

[0032] As a slot die is a heavy component with a length of approximately 1m, a large-scale coating system must be configured for it. Special means must be devised to form a uniform coating layer over a large area, and accordingly, the present invention provides a jig dedicated to slot dies. A turntable-type jig capable of rotational driving during the coating process is configured with the slot die inserted horizontally rather than vertically. Additionally, the coating ion source and the sputter source are installed in parallel along the length of the slot die within the vacuum chamber. It is preferable that the linear ion source and the sputter source be arranged radially, that is, in a manner that surrounds the slot die, which is the object to be coated.

[0033] The present invention is designed so that eight slot dies can be mounted on a slot die jig, and two linear ion sources (first linear ion source, second linear ion source) and two sputter sources (first sputter source, second sputter source) are mounted in a chamber. Gas supply branches are configured such that there are two gas supply units for each sputter source, thereby configuring a total of six coating source supply units. This configuration provides a coating layer of high uniformity over the entire large slot die.

[0034] FIG. 2 is a cross-sectional view of a slot die jig according to the present invention.

[0035] Rotating plates (120) are configured at each end of the central axis (110).

[0036] There is a slot die fixing part (125) capable of fixing the ends of the fixing bar (11) fixed at both ends of the slot die (10), and a rotation part (127) that enables the slot die to rotate at the part where the fixing part (125) extends and contacts the rotating plate (120). That is, the slot dies (10) revolve as the rotating plate (120) rotates by the central axis (110), and rotate by the rotation part (127) to perform the coating process. For reference, if the slot die (10) originally does not have a fixing bar (11), a separate fixing bar can be made and installed.

[0037] The horizontal arrangement of such slot dies is achieved by a support (130) capable of supporting a turntable (120). The support (130) supports and seats the turntable (120) and is equipped with a bearing block including a bearing or a rotational part (135) including a rotational rail so that the turntable (120) can rotate. The turntable (120) has a part that directly fixes the slot die and a part that protrudes further outward than the turntable (120) for support and rotation of the turntable, and the part that protrudes outward is directly mounted on the support.

[0038] The present invention enables the mounting of eight slot dies on a single jig. This is illustrated in the side cross-sectional view of FIG. 3.

[0039] For the rotation of the slot die (10), the inner diameter side of the rotating plate (120) and the border with the rotation part (127) are configured as a gear (128) (see FIG. 4).

[0040] In addition, the uniformity of the coating can be improved over the entire large slot die by configuring the slot die dedicated jig (100) as described above. FIG. 5 shows the results of a test coating without a slot die dedicated jig and the results of a coating layer applied while mounted on a slot die dedicated jig and rotating the die, showing that a uniform coating thickness can be obtained across the door side (D), middle side (M), and chamber side (C).

[0041] In addition, to perform a uniform coating on the entire slot die that is horizontally arranged and rotates within the chamber, linear ion sources and sputter sources are arranged on the walls and ceiling of the chamber at predetermined intervals to surround the slot die, and the gas supply unit of a single sputter source is configured into multiple branches. In the case of the present invention, first and second linear ion sources and first and second sputter sources are configured, and each sputter source is configured with two gas supply units, so that the source units connected to the chamber are totaled six. For each sputter source, one target and two gas supply units are provided, and the gas supply units are arranged in a branch form.

[0042] The linear ion source, sputter source, and gas supply unit are arranged with their lengths parallel to the direction in which the slot dies are arranged, and are configured to have a length greater than the total length of the slot dies.

[0043] In addition, the coating system of the present invention is configured to observe the plasma discharge state (plasma density distribution) and process variables (presence or absence of arcing, change in atmospheric pressure, change in current with respect to applied voltage, change in bias current with respect to bias voltage, etc.) of the coating process in real time, and accordingly, to control the power supply and gas supply unit in real time. That is, after optimizing the process by designing upper and lower limits for process variables, sudden variable changes occurring during the coating process are finely observed, and the process variables are customized in real time using this as feedback.

[0044] In particular, the formation of the buffer layer, which affects the coating adhesion and the physical properties of the top layer, is achieved through multi-stage control.

[0045] The present invention utilizes such a coating system to perform plasma cleaning, form a Cr-based buffer layer, and form a DLC top layer on a slot die, and to this end, the process is carried out as follows.

[0046] By vacuuming the chamber, 6.3×10 -6 Up to 7.7×10-6 Do it as Torr.

[0047] A current of 200 to 1000 mA and a voltage of 800 to 2000 V are applied to the first linear ion source and the second linear ion source, and an inert gas is flowed at 80 to 200 sccm to discharge plasma, and a bias voltage of 100 to 800 V and a bias current of 0.5 to 1.5 A are applied to the slot die to perform plasma cleaning for 60 to 150 minutes, and

[0048] A Cr target is arranged in a first sputter source and a second sputter source, a current of 500 to 2500 mA and a voltage of 100 to 700 V are applied and an inert gas is flowed at 50 to 300 sccm to discharge a plasma, and a bias voltage of 50 to 600 V, preferably 50 to 250 V, and a bias current of 0.1 to 1.0 A are applied to a slot die to form a Cr layer for 5 to 30 minutes, and thereafter, under the same conditions, an N2 gas is flowed at 5 to 50 sccm to form a CrN layer, and the formation of the CrN layer is repeated three times for 5 to 30 minutes each, and thereafter, under the same conditions, the N2 gas supply is stopped and a hydrocarbon gas is supplied at 5 to 30 sccm to form a CrC layer, thereby forming a Cr / CrN / CrC buffer layer.

[0049] A current of 200 to 1000 mA and a voltage of 800 to 2000 V are applied to a first linear ion source and a second linear ion source, and an inert gas is flowed at 80 to 200 sccm and a hydrocarbon gas at 100 to 300 sccm to discharge plasma, and a bias voltage of 100 to 600 V and a bias current of 0.5 to 1.5 A are applied to a slot die to form a DLC coating layer for 200 to 480 minutes.

[0050] In the above, the buffer layer formation process is controlled to a total of 60 minutes or less.

[0051] Meanwhile, as described above, a modified embodiment can be constructed in which the buffer layer is modified to Ti / TiN / TiC. The sputter target is changed to Ti, and the same process is performed.

[0052] In addition, a modified embodiment in which the buffer layer is an amorphous silicon (a-Si) layer is also possible. The sputter target may be made of high-purity silicon and the same process may be carried out, or the process may be carried out by adding a small amount (5 to 20 sccm) of H2 gas in addition to inert gas (Ar) and nitrogen (N2) gas.

[0053] Figure 6 is a schematic diagram of plasma cleaning. Plasma cleaning is performed by supplying Ar gas in the present invention to remove impurities and etch the substrate surface to a shallow depth (0.032 to 0.052 μm) to strengthen the bonding strength of the buffer layer.

[0054] The present invention obtained results of a coating hardness of 1900 to 2000 Hv, a coating bonding strength of 30 N or more, a friction coefficient of less than 0.15, and a coating thickness uniformity of less than 2.5 μm.

[0055] Figure 7 shows the actual measured values ​​of the adhesion force and friction coefficient exhibited by the coating layer of the present invention.

[0056] Figure 8 is a photograph showing the thickness uniformity of the coating layer of the present invention.

[0057] It can be confirmed that all parts of the slot die length are coated with almost the same thickness.

[0058] According to the present invention, a coating system using a slot die dedicated jig satisfied all requirements of the slot die demand company evaluation, and in particular, sufficiently satisfied uniformity and flatness. After coating, the flatness of the standard requirement of 5 µm or less for the slot die product was satisfied at 1.4 µm or less, and the coating thickness uniformity of the standard requirement of 2.5 µm or less was satisfied at 2.23 ± 0.01 µm.

[0059] Unless otherwise defined in the foregoing, all technical and scientific terms used in this specification have the same meaning as commonly understood by a skilled expert in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. Throughout the specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Additionally, the singular form may include the plural form depending on the context.

[0060] The rights of the present invention are not limited to the embodiments described above but are defined by what is stated in the claims, and it is obvious that a person skilled in the art can make various modifications and productions within the scope of the rights stated in the claims. Explanation of the symbols

[0061] Slot die (10), fixed bar (11), central axis (110), rotating plate (120), slot die fixing part (125), rotating part (127), gear (128), stand (130), orbiting part (135)

Claims

Claim 1 A coating system for forming a coating layer on a slot die comprises: a chamber; a slot die dedicated jig capable of mounting a plurality of slot dies horizontally and loading them into the chamber, and rotating the slot dies during the coating process; a linear ion source and a sputter source mounted in the chamber; and a process variable control unit; wherein the slot die dedicated jig comprises: a central axis for rotation and a rotating plate provided at each end of the central axis; a plurality of slot die fixing parts installed on the rotating plate and arranged radially with respect to the central axis; a rotating part extending from the slot die fixing part and contacting the rotating plate, capable of rotating the slot die with respect to the central axis of the slot die fixing part; and a mounting bracket capable of mounting the rotating plate at the lower end of the rotating plate.The mounting bracket includes a bearing block including a bearing or a rotating rail including a rotating rail to enable rotational driving of the rotating plate, the linear ion source includes a first linear ion source and a second linear ion source, the sputter source includes a first sputter source and a second sputter source, and the first sputter source and the second sputter source each include two gas supply units, and in order to perform uniform coating with respect to the longitudinal direction of the slot die, the first linear ion source and the second linear ion source, and the first sputter source and the second sputter source are arranged at a predetermined interval on the wall and ceiling surfaces of the chamber as if surrounding the slot dies, and a total of six source units are arranged in the chamber including the gas supply units of the first linear ion source and the second linear ion source, and the first sputter source and the second sputter source, and the first linear ion source, the second linear ion source, the first sputter source, the second sputter source, and the gas supply units have a direction parallel to the direction in which the slot dies are arranged as their longitudinal direction. A coating system for slot die coating, characterized in that it is arranged and has a length longer than the total length of the slot die, and the process variable control unit observes in real time the plasma discharge state, the presence or absence of arcing, atmospheric pressure change, current change with respect to applied voltage, and bias current change with respect to bias voltage, and accordingly controls the power supply and gas supply unit in real time, receives input of the process pressure in the chamber, the applied voltage and applied current for the first linear ion source and the second linear ion source and the first sputter source and the second sputter source, and the upper and lower limits of the process variables including the bias applied voltage and applied current, precisely observes sudden variable changes occurring during coating execution, and uses this as feedback to custom-control the process variables in real time, thereby providing a uniform coating layer over the entire slot die. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A coating system for slot die coating according to claim 1, wherein the slot die jig includes a gear on the inner diameter side of the rotating plate and on the contact side with the rotating part for the rotation of the slot die. Claim 6 delete Claim 7 A coating system for slot die coating, characterized in that, in either claim 1 or claim 5, the first linear ion source and the second linear ion source are used to form a DLC coating layer as a top layer after performing plasma cleaning on the slot die and forming a buffer layer by a sputter source, and the first sputter source and the second sputter source are used to form a Cr-based buffer layer. Claim 8 A coating method using a coating system for slot die coating according to either claim 1 or 5, comprising: initial vacuuming a chamber; applying a current of 200 to 1000 mA and a voltage of 800 to 2000 V to a first linear ion source and a second linear ion source and flowing an inert gas at 80 to 200 sccm to discharge plasma; applying a bias voltage of 100 to 800 V and a bias current of 0.5 to 1.5 A to a slot die to perform plasma cleaning for 60 to 150 minutes; arranging a Cr target in a first sputter source and a second sputter source; applying a current of 500 to 2500 mA and a voltage of 100 to 700 V and flowing an inert gas at 50 to 300 sccm to discharge plasma; applying a bias voltage of 50 to 250 V and a bias current of 0.1 to 1.0 A to a slot die A bias current is applied to form a Cr layer for 5 to 30 minutes, and subsequently, while maintaining the same conditions, N2 gas is additionally flowed at 5 to 50 sccm to form a CrN layer, wherein the formation of the CrN layer is repeated three times for 5 to 30 minutes each, and subsequently, while maintaining the same conditions, the N2 gas supply is stopped and hydrocarbon gas is supplied at 5 to 30 sccm to form a CrC layer, thereby forming a Cr / CrN / CrC buffer layer; a current of 200 to 1000 mA and a voltage of 800 to 2000 V are applied to the first linear ion source and the second linear ion source, and an inert gas is flowed at 80 to 200 sccm and a hydrocarbon gas at 100 to 300 sccm to discharge plasma, and a bias voltage of 100 to 600 V and a bias current of 0.5 to 1.5 A are applied to the slot die for 200 to 480 minutes A coating method using a coating system for slot die coating characterized by forming a DLC coating layer. Claim 9 delete Claim 10 A coating method using a slot die coating system, characterized in that, in claim 8, the process of forming a Cr / CrN / CrC buffer layer is controlled to be carried out for a total of 60 minutes or less.

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