Plasma coating equipment

Abstract

Plasma coating equipment comprises an evaporation source assembly and a secondary ionization electrode device. The evaporation source assembly is configured to carry a target material and ionize a surface of the target material by arc discharge to generate a flow of coating particles. And the secondary ionization electrode device is arranged between the evaporation source assembly and the workpiece to be coated. And the secondary ionization electrode device is configured to perform arc discharge on the coating particle flow flowing through the secondary ionization electrode device so as to further heat and ionize the metal liquid drops in the coating particle flow.

Description

Technical Field

[0001] The present invention belongs to the technical field of vacuum coating, and in particular, relates to a plasma coating device. Background Art

[0002] The traditional multi-arc ion plating technology realizes the gasification and ionization process of the material at one time through arc discharge on the surface of the target. However, in this process, the target surface will have a molten pool and a micro-explosion of the molten pool caused by instantaneous evaporation due to arc discharge, causing part of the material to fly out of the target surface in the form of droplets. On the one hand, this part of the droplets is not ionized and cannot react with the reaction gas to produce the required coating components. On the other hand, the droplets are large in size and will cool and deposit on the surface of the product, destroying the density of the prepared coating and affecting the roughness of the coating. Summary of the invention

[0003] In view of this, the present application provides a plasma coating device to solve the above problems.

[0004] According to an embodiment of the present application, a plasma coating device is provided, comprising: an evaporation source component and a secondary ionization electrode device. The evaporation source component is configured to carry a target material, and ionize the surface of the target material by arc discharge to generate a coating particle flow. The secondary ionization electrode device is arranged between the evaporation source component and a workpiece to be coated. The secondary ionization electrode device is configured to perform arc discharge on the coating particle flow flowing through the secondary ionization electrode device to further heat and ionize the metal droplets in the coating particle flow.

[0005] In some embodiments, the secondary ionization electrode device comprises: a first electrode and a second electrode. The first electrode and the second electrode are respectively connected to two poles of a power supply. The first electrode and the second electrode comprise teeth that are staggered and arranged in parallel.

[0006] In some embodiments, the spacings between adjacent teeth are the same.

[0007] In some embodiments, the overlapping areas of two adjacent teeth are equal.

[0008] In some embodiments, an overlapping area of ​​two adjacent teeth decreases from the center to the edge of the first electrode and the second electrode.

[0009] In some embodiments, the secondary ionization electrode device includes a plurality of electrode pairs consisting of the first electrode and the second electrode, and the plurality of electrode pairs are arranged in different planes.

[0010] In some embodiments, in two adjacent pairs of electrodes, the position of the first electrode of one of the electrode pairs corresponds to the position of the second electrode of the other electrode pair.

[0011] In some embodiments, the distance from the center to the edge of the first electrode and the second electrode is greater than the distance from the target to the workpiece to be coated.

[0012] In some embodiments, the distance between the target material and the workpiece to be coated is L, and the distance between the secondary ionization electrode device and the target material is D, wherein 0.25L≤D≤0.75L is satisfied.

[0013] In some embodiments, the secondary ionization electrode device further comprises: a position adjustment device. The position adjustment device is connected to one end of the first electrode and the second electrode. The position adjustment device is configured to adjust the position of the first electrode and the second electrode between the evaporation source assembly and the workpiece to be coated.

[0014] In some embodiments, the position adjustment device includes a retractable connecting rod and a driving device. The retractable connecting rod extends in a vertical direction. One end of the retractable connecting rod is connected to the first electrode and the second electrode. The other end of the retractable connecting rod is connected to the driving device.

[0015] In some embodiments, the first electrode and the second electrode include a conductive material having a temperature resistance of more than 2500° C.

[0016] In some embodiments, the first electrode and the second electrode include hafnium, tungsten, tantalum, graphite, conductive boron nitride, or conductive silicon nitride.

[0017] In certain embodiments, the first electrode and the second electrode include metal tubes through which cooling water flows.

[0018] In some embodiments, the evaporation source assembly includes: an arc limiting ring and an auxiliary electrode. The arc limiting ring is arranged around the target. The arc limiting ring is configured to limit the arc on the surface of the target. The auxiliary electrode and the target are respectively connected to two poles of an arc power supply. The auxiliary electrode is configured to adjust the coating effect by changing the relative position with the target.

[0019] In some embodiments, the auxiliary electrode includes a plurality of sub-electrodes, and the arrangement configuration of the plurality of sub-electrodes constitutes the appearance of the auxiliary electrode.

[0020] In some embodiments, the evaporation source assembly further includes a control device connected between the auxiliary electrode and the arc power source, and configured to selectively control the auxiliary electrode to operate in a first mode, a second mode, or a third mode.

[0021] In some embodiments, when operating in the first mode, the control device controls the auxiliary electrode and the surface of the target material to be located in the same plane.

[0022] In some embodiments, when operating in the first mode, the control device controls the plurality of sub-electrodes to be arranged in a ring shape, so that the auxiliary electrode forms a ring structure surrounding the arc-limiting ring.

[0023] In some embodiments, when operating in the first mode, the arc power supply provides an arc current in the range of 60-300A.

[0024] In some embodiments, when operating in the second mode, the control device controls the auxiliary electrode to be located between the target and the secondary ionization electrode device, and the vertical distance between the auxiliary electrode and the target is smaller than the diameter of the target.

[0025] In some embodiments, the control device controls the plurality of sub-electrodes to be arranged in a ring shape, so that the projection of the auxiliary electrode on the plane where the arc-limiting ring is located forms a ring structure surrounding the arc-limiting ring.

[0026] In some embodiments, the control device controls the multiple sub-electrodes to gather together so that the auxiliary electrode has a rod-like structure, and the rod-like structure is coaxial with the central axis of the target material.

[0027] In some embodiments, when operating in the second mode, the arc power supply provides an arc current in the range of 301-600A.

[0028] In some embodiments, when operating in the third mode, the control device controls the auxiliary electrode to be located between the target and the secondary ionization electrode device, and the vertical distance between the auxiliary electrode and the target is greater than the diameter of the target.

[0029] In some embodiments, the control device controls the plurality of sub-electrodes to be arranged in a ring shape, so that the projection of the auxiliary electrode on the plane where the arc-limiting ring is located forms a ring structure surrounding the arc-limiting ring.

[0030] In some embodiments, the control device controls the multiple sub-electrodes to gather together so that the auxiliary electrode has a rod-like structure, and the rod-like structure is coaxial with the central axis of the target material.

[0031] In some embodiments, when operating in the third mode, the arc power supply provides an arc current in the range of 601-800A.

[0032] The plasma coating equipment proposed by the present invention can further heat, evaporate and ionize the metal droplets in the coating particle flow by setting the secondary ionization electrode device, thereby improving the coating fineness. In addition, the required coating effect can be adjusted in detail by setting the auxiliary electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application but do not constitute a limitation to the present application. In the accompanying drawings:

[0034] Figure 1 A schematic diagram illustrating a plasma coating device according to an embodiment of the present application.

[0035] Figure 2A and Figure 2B Two top views of the first electrode and the second electrode in different states are respectively demonstrated.

[0036] Figure 3 A three-dimensional view of a secondary ionization electrode device according to an embodiment of the present application is demonstrated.

[0037] Figure 4 A schematic diagram illustrating a position adjustment device according to an embodiment of the present application.

[0038] Figure 5A and Figure 5B Schematic diagrams demonstrating two different types of auxiliary electrodes.

[0039] Fig. 6A A schematic diagram illustrating an auxiliary electrode operating in a first mode according to an embodiment of the present application.

[0040] Figure 6B A schematic diagram illustrating an auxiliary electrode operating in a second mode according to an embodiment of the present application.

[0041] Figure 6C A schematic diagram illustrating an auxiliary electrode operating in a second mode according to an embodiment of the present application.

[0042] Fig.6D A schematic diagram illustrating an auxiliary electrode operating in a third mode according to an embodiment of the present application.

[0043] Fig. 6E A schematic diagram illustrating an auxiliary electrode operating in a third mode according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following disclosure provides a variety of implementations or illustrations that can be used to implement different features of the present disclosure. The specific examples of components and configurations described below are used to simplify the present disclosure. As can be imagined, these descriptions are only illustrative and are not intended to limit the present disclosure. For example, in the description below, forming a first feature on or above a second feature may include certain embodiments in which the first and second features are directly in contact with each other; and may also include certain embodiments in which additional components are formed between the above-mentioned first and second features, so that the first and second features may not be in direct contact. In addition, the present disclosure may reuse component symbols and / or labels in multiple embodiments. Such repetition is based on the purpose of simplicity and clarity, and does not itself represent the relationship between the different embodiments and / or configurations discussed.

[0045] Furthermore, spatially relative terms such as "below," "below," "below," "above," and the like may be used herein to facilitate description of the relationship between one component or feature shown in the figure relative to another or more components or features. These spatially relative terms are intended to encompass a variety of different orientations of the device during use or operation in addition to the orientation shown in the figure. The device may be placed in other orientations (e.g., rotated 90 degrees or in other orientations), and these spatially relative descriptive terms should be interpreted accordingly.

[0046] Although the numerical ranges and parameters used to define the broader scope of the present application are approximate values, the relevant numerical values ​​in the specific embodiments have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual test methods. Here, "about" generally refers to the actual value within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range. Alternatively, the term "about" means that the actual value falls within the acceptable standard error of the mean value, depending on the consideration of a person with ordinary knowledge in the technical field to which the present application belongs. It should be understood that, except for the experimental examples, or unless otherwise explicitly stated, all ranges, quantities, values ​​and percentages used herein (for example, to describe the amount of material used, the length of time, temperature, operating conditions, quantitative ratios and other similar ones) are modified by "about". Therefore, unless otherwise stated to the contrary, the numerical parameters disclosed in this specification and the attached claims are all approximate values ​​and can be changed as needed. At least these numerical parameters should be understood as the number of significant digits indicated and the values ​​obtained by applying the general rounding method. Herein, numerical ranges are expressed from one endpoint to another endpoint or between two endpoints; unless otherwise stated, the numerical ranges described herein include the endpoints.

[0047] In order to reduce the influence of droplets on coating, the existing technology mainly adopts the technical methods of (1) inhibiting the formation of droplets, or (2) filtering droplet particles. Among the technologies for inhibiting the formation of droplets, the common ones are: cooling the temperature of the target surface by cooling water to inhibit the burst of large droplets; or reducing the intensity of the arc current during coating to make the arc on the target surface more uniform and the cooling more uniform to improve the coating quality; or using a composite pulse current (a DC or unipolar pulse arc power supply coupled with a bipolar pulse power supply) to evaporate the target material and reduce the formation of droplets. Among the technologies for filtering droplet particles, the common ones are: shielding the droplets by placing a mechanical structure of a baffle to prevent the droplets from reaching the workpiece to be coated; or setting up a magnetic filtration system to reduce large droplets during the coating process.

[0048] However, the above existing technologies all have their disadvantages. For example, cooling the target surface temperature will cause excessive condensation on the device surface, which is not conducive to the stability of the device. For example, reducing the arc current intensity will also reduce the evaporation rate of the target material, affecting the coating speed, etc.

[0049] In view of this, the present application provides a plasma coating device to solve the above technical problems. Figure 1 A schematic diagram of a plasma coating device 10 according to an embodiment of the present application is demonstrated. The plasma coating device 10 is configured to coat a workpiece X to be coated. In some embodiments, the plasma coating device 10 includes an evaporation source assembly 11 and a secondary ionization electrode device 12. The evaporation source assembly 11 is connected to an arc power supply V2, and the evaporation source assembly 11 is configured to carry a target material TR, and ionize the surface of the target material TR by arc discharge to generate a coating particle flow LR. The coating particle flow LR includes metal atoms, metal ions, metal droplets, gas atoms, and gas ions, wherein the metal droplets will affect the coating quality.

[0050] In some embodiments, the secondary ionization electrode device 12 is disposed between the evaporation source assembly 11 and the workpiece to be coated X. The secondary ionization electrode device 12 is configured to perform arc discharge on the coating particle flow LR flowing through the secondary ionization electrode device 12 to further heat and ionize the metal droplets in the coating particle flow LR. The secondary ionization electrode device 12 includes a first electrode 121 and a second electrode 122. Figure 2A and Figure 2B Two different top views of the first electrode 121 and the second electrode 122 are shown. In some embodiments, the first electrode 121 and the second electrode 122 include teeth 20 that are staggered and arranged in parallel, and the spacing between the staggered teeth 20 is the same.

[0051] exist Figure 2AIn the embodiment, each tooth-shaped portion 20 of the first electrode 121 and the second electrode 122 has the same length. In this design, when the first electrode 121 and the second electrode 122 are arranged alternately, the overall outer contour area S1 is similar to a rectangle, and the overlapping areas of two adjacent tooth-shaped portions 20 are equal. Figure 2B In the embodiment, the teeth 20 of the first electrode 121 and the second electrode 122 at the middle position are longer than the teeth 20 at the edge position. With such a design, when the teeth of the first electrode 121 and the second electrode 122 are arranged in a staggered manner, the overall outer contour area S1 is similar to a circle, and the overlapping area of ​​two adjacent teeth 20 at the middle position is larger than the overlapping area of ​​two adjacent teeth 20 at the edge position. Figure 2A and 2B This application does not limit the shapes of the first electrode 121 and the second electrode 122 .

[0052] The first electrode 121 and the second electrode 122 are connected to the two poles of the power source V1, respectively, so that an arc discharge is formed between the first electrode 121 and the second electrode 122. The tiny protrusions on the surface first become the arc starting points, so that the droplets deposited on the first electrode 121 and the second electrode 122 are evaporated and ionized again by the arc. The coating particle flow LR that passes through but does not contact the first electrode 121 and the second electrode 122 will also form a metal vapor arc between the first electrode 121 and the second electrode 122, so that the metal droplets in the coating particle flow LR are further heated, evaporated and ionized. Accordingly, the droplet size gradually becomes smaller and the number decreases.

[0053] In addition, a plasma region is formed around the first electrode 121 and the second electrode 122. The coating particle flow LR passes through the plasma around the first electrode 121 and the second electrode 122 and then deposits on the surface of the coating product. The metal and gas atoms in the coating particle flow LR are also ionized again in this process to become metal ions and gas ions. The coating surface prepared in the above manner is smoother, has less roughness, improves the film quality, and improves the performance.

[0054] The actual total area of ​​the teeth 20 of the first electrode 121 and the second electrode 122 should not be too large to avoid completely blocking the movement path of the coating particle flow LR. In some embodiments, the actual total area S2 of the teeth 20 of the first electrode 121 and the second electrode 122 accounts for 40%-60% of the outer contour projection area S1 of the first electrode 121 and the second electrode 122. In some embodiments, the distance B from the center to the edge of the first electrode 121 and the second electrode 122 is greater than the distance L between the target TR and the workpiece X to be coated.

[0055] In some embodiments, the power of the power source V1 connected to the first electrode 121 and the second electrode 122 is set to a constant power P V1, where P V1 =KS2 / S1*P V2 , where P V2 is the power of the arc power source V2, and the power coefficient K can be adjusted according to different modes of the evaporation source assembly 11. In some embodiments, the coefficient K is selectively within the range of 0.7-1.5.

[0056] In some embodiments, the first electrode 121 and the second electrode 122 include a conductive material with a temperature resistance of more than 2500° C. In some embodiments, the first electrode 121 and the second electrode 122 include, but are not limited to, hafnium, tungsten, tantalum, graphite, conductive boron nitride or conductive silicon nitride. In some embodiments, the first electrode 121 and the second electrode 122 include a metal tube with cooling water flowing therein.

[0057] In some embodiments, the secondary ionization electrode device 12 may include two or more electrode pairs consisting of a first electrode 121 and a second electrode 122 to form an arc discharge area with a larger coverage area, so as to more effectively heat, evaporate and ionize the metal droplets in the coating particle flow LR. Figure 3 , Figure 3 A three-dimensional view of a secondary ionization electrode device 12 according to an embodiment of the present application is demonstrated. In some embodiments, the secondary ionization electrode device 12 includes a plurality of electrode pairs consisting of a first electrode 121 and a second electrode 122, which are respectively arranged on different planes in the vertical direction Z. In two adjacent groups of electrode pairs in the vertical direction Z, the position of the first electrode 121 of one group of electrode pairs corresponds to the position of the second electrode 122 of the other group of electrode pairs. With such a design, an arc discharge region can also be formed between the upper and lower adjacent first electrodes 121 and second electrodes 122, further heating, evaporating and ionizing the metal droplets in the coating particle flow LR.

[0058] If the secondary ionization electrode device 12 is too close to the target material TR, the coating particle flow LR reaching the secondary ionization electrode device 12 is too concentrated, and most of the arc discharge area of ​​the secondary ionization electrode device 12 cannot be effectively utilized, and the effect on the droplets is weakened. If the secondary ionization electrode device 12 is too close to the workpiece to be coated X, the plasma area around the secondary ionization electrode device 12 will cover the workpiece to be coated X, so that the coating on the workpiece to be coated X will be etched again, resulting in excessive internal stress of the coating and a slower coating rate. In some embodiments, the distance L between the target material TR and the workpiece to be coated X is D, and the distance from the secondary ionization electrode device 12 to the target material TR satisfies 0.25L≤D≤0.75L. Preferably, D=0.5L.

[0059] In some embodiments, in order to facilitate adjustment of the distance D between the secondary ionization electrode device 12 and the target material TR, the secondary ionization electrode device 12 further includes a position adjustment device 50. Figure 4 , Figure 4 A schematic diagram of a position adjustment device 50 according to an embodiment of the present application is demonstrated. The position adjustment device 50 is configured to adjust the position of the first electrode 121 and the second electrode 122 between the evaporation source assembly 11 and the workpiece X to be coated. In some embodiments, the position adjustment device 50 includes a retractable connecting rod 51 and a driving device 52. The retractable connecting rod 51 extends along the vertical direction Z. One end of the retractable connecting rod 51 is connected to the first electrode 121 and the second electrode 122, and the other end is connected to the driving device 52. The driving device 52 drives the retractable connecting rod 51 together with the first electrode 121 and the second electrode 122 to move in the vertical direction Z to adjust the distance D from the secondary ionization electrode device 12 to the target material TR. In some embodiments, the driving device 52 includes a stepping motor.

[0060] Reference again Figure 1 The evaporation source assembly 11 includes an arc limiting ring 111, an auxiliary electrode 112, and a control device (not shown). The arc limiting ring 111 is arranged around the target material TR, and is configured to limit the arc on the surface of the target material TR. The auxiliary electrode 112 and the target material TR are respectively connected to the two poles of the arc power supply V2. The auxiliary electrode 112 is configured to adjust the coating effect by changing the relative position and appearance configuration with the target material TR.

[0061] In some embodiments, the auxiliary electrode 112 includes a plurality of sub-electrodes 1121 (shown in FIG. Figure 5A and Figure 5B ), wherein the arrangement configuration of the plurality of sub-electrodes 1121 constitutes the appearance of the auxiliary electrode 112. Figure 5A As shown, when a plurality of sub-electrodes 1121 are arranged, the auxiliary electrode 112 can form a ring structure. Figure 5B As shown, when the plurality of sub-electrodes 1121 are arranged together, the auxiliary electrode 112 forms a rod-like structure.

[0062] In some embodiments, the control device controls the operation mode of the auxiliary electrode 112 to selectively operate in the first mode, the second mode or the third mode. Corresponding to different operation modes, the auxiliary electrode 112 will be located at a corresponding position and have a corresponding configuration to adjust the coating effect.

[0063] Fig. 6A Schematic diagram showing the auxiliary electrode 112 operating in the first mode according to an embodiment of the present application. In some embodiments, when operating in the first mode, the control device controls the auxiliary electrode 112 to be located in the same plane as the surface of the target material TR. In some embodiments, when operating in the first mode, the control device controls the plurality of sub-electrodes 112 to be arranged so that the auxiliary electrode 112 becomes Figure 5AThe annular structure shown surrounds the annular structure of the arc limiting ring 111. In some embodiments, when operating in the first mode, the arc current provided by the arc power supply V2 is in the range of 60-300A. In some embodiments, when operating in the first mode, the power coefficient K can be in the range of 0.7-1.0. Preferably, the power coefficient K can be in the range of 0.8-1.0.

[0064] Figure 6B Schematic diagram showing the auxiliary electrode 112 operating in the second mode according to an embodiment of the present application. In some embodiments, when operating in the second mode, the control device controls the auxiliary electrode 112 to be located between the target material TR and the secondary ionization electrode device 12, and the vertical distance D between the auxiliary electrode 112 and the target material TR is less than the diameter of the target material TR. In some embodiments, when operating in the second mode, the control device controls the plurality of sub-electrodes 112 to be arranged so that the auxiliary electrode 112 becomes Figure 5A The annular structure shown in FIG. 1 is a ring structure, and the projection on the plane where the arc limiting ring 111 is located surrounds the arc limiting ring 111. However, in other embodiments, reference Figure 6C When operating in the second mode, the control device can control the plurality of sub-electrodes 112 to gather together so that the auxiliary electrode 112 becomes as follows: Figure 5B The rod-shaped structure is shown and the auxiliary electrode 112 is coaxial with the central axis TR of the target. In some embodiments, when operating in the second mode, the arc current provided by the arc power source V2 is in the range of 300-600 A. In some embodiments, when operating in the second mode, the power coefficient K can be in the range of 0.9-1.3. Preferably, the power coefficient K can be in the range of 1.0-1.2.

[0065] Fig.6D Schematic diagram showing the auxiliary electrode 112 operating in the third mode according to an embodiment of the present application. In some embodiments, when operating in the third mode, the control device controls the auxiliary electrode 112 to be located between the target material TR and the secondary ionization electrode device 12, and the vertical distance D between the auxiliary electrode 112 and the target material TR is greater than the diameter of the target material TR. In some embodiments, when operating in the third mode, the control device controls the plurality of sub-electrodes 112 to be arranged so that the auxiliary electrode 112 becomes Figure 5A The annular structure shown in FIG. 1 is a ring structure, and the projection on the plane where the arc limiting ring 111 is located surrounds the arc limiting ring 111. However, in other embodiments, reference Fig. 6E When operating in the third mode, the control device can control the plurality of sub-electrodes 112 to gather together so that the auxiliary electrode 112 becomes as follows: Figure 5BThe rod-shaped structure is shown and the auxiliary electrode 112 is coaxial with the central axis TR of the target. In some embodiments, when operating in the third mode, the arc current provided by the arc power source V2 is in the range of 600-800 A. In some embodiments, when operating in the third mode, the power coefficient K can be in the range of 1.1-1.5. Preferably, the power coefficient K can be in the range of 1.2-1.4.

[0066] The applicant conducted a series of experiments on various combinations of electrical parameters of the arc power source V2, the operation mode of the auxiliary electrode 112, the coefficient K of the secondary ionization electrode device 12, and the S2 / S1 area ratio to verify the coating rate and roughness. The parameters of each embodiment are listed in Table 1 below, and the experimental results are listed in Table 2 below.

[0067] Table 1

[0068]

[0069]

[0070] Table 2

[0071]

[0072]

[0073] From the comparison of the experimental results of Examples 1 and 3, 14 and 16, 22 and 26 and Control Groups 1 and 2, it can be seen that in the first mode, when the arc current is the same, although the coating rate of Examples 1 and 3 is about 80% of that of Control Groups 1 and 2, the coating roughness is significantly improved, and the roughness is less than 0.1μm; in the second mode, the coating rate is significantly improved, and the roughness is about 0.15-0.21μm; in the third mode, the coating rate is significantly improved, and the roughness is about 0.28-0.39μm;

[0074] From the comparison of the experimental results of Examples 11 and 13, it can be seen that when other conditions are the same, the coating roughness of the first mode is lower than that of the second mode, but the coating rate is slower. From the comparison of the experimental results of Examples 18 and 22, it can be seen that when other conditions are the same, the coating roughness of the second mode is lower than that of the third mode, but the coating rate is slower.

[0075] From the comparison of the experimental results of Examples 2-6, 15-19 and 21-25, it can be seen that, no matter the operation is in the first mode, the second mode or the third mode, the larger the power coefficient K is, the faster the coating rate is and the lower the roughness is.

[0076] From the comparison of the experimental results of Examples 5, 10, 12 and 13, it can be seen that the higher the S2 / S1 area ratio, the lower the roughness.

[0077] From the comparison of the experimental results of Examples 3, 7, 8 and 9, it can be seen that the closer the secondary ionization electrode device 12 is to the target material TR, the higher the roughness; conversely, the farther away from the target material TR, the lower the roughness.

[0078] From the comparison of the experimental results of Examples 18 and 20 and 26 and 27, it can be seen that the rod-shaped electrode has a faster coating speed than the ring-shaped electrode, and the difference in roughness is not significant.

[0079] As used herein, the terms "approximately", "substantially", "substantially" and "about" are used to describe and take into account small changes. When used in conjunction with an event or situation, the term may refer to an example where the event or situation occurs exactly and an example where the event or situation occurs very approximately. As used herein with respect to a given value or range, the term "about" generally means within ±10%, ±5%, ±1% or ±0.5% of a given value or range. A range may be expressed herein as from one endpoint to another or between two endpoints. Unless otherwise specified, all ranges disclosed herein include endpoints. The term "substantially coplanar" may refer to two surfaces within a few microns (μm) positioned along the same plane, for example, within 10 μm, within 5 μm, within 1 μm or within 0.5 μm positioned along the same plane. When referring to a "substantially" identical numerical value or characteristic, the term may refer to a value within ±10%, ±5%, ±1% or ±0.5% of the average value of the value.

[0080] As used herein, the terms "approximately," "substantially," "substantially," and "about" are used to describe and explain small variations. When used in conjunction with an event or circumstance, the terms may refer to instances where the event or circumstance occurred exactly as well as instances where the event or circumstance occurred very approximately. For example, when used in conjunction with a numerical value, the terms may refer to a range of variation of less than or equal to ±10% of the numerical value, for example, less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, two values ​​may be considered "substantially" or "approximately" the same if the difference between them is less than or equal to ±10% of the average of the values ​​(e.g., less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%). For example, "substantially" parallel can refer to an angular variation range of less than or equal to ±10° relative to 0°, for example, less than or equal to ±5°, less than or equal to ±4°, less than or equal to ±3°, less than or equal to ±2°, less than or equal to ±1°, less than or equal to ±0.5°, less than or equal to ±0.1°, or less than or equal to ±0.05°. For example, "substantially" vertical can refer to an angular variation range of less than or equal to ±10° relative to 90°, for example, less than or equal to ±5°, less than or equal to ±4°, less than or equal to ±3°, less than or equal to ±2°, less than or equal to ±1°, less than or equal to ±0.5°, less than or equal to ±0.1°, or less than or equal to ±0.05°.

[0081] For example, two surfaces may be considered coplanar or substantially coplanar if the displacement between the two surfaces is equal to or less than 5 μm, equal to or less than 2 μm, equal to or less than 1 μm, or equal to or less than 0.5 μm. A surface may be considered planar or substantially planar if the displacement between any two points on the surface relative to the plane is equal to or less than 5 μm, equal to or less than 2 μm, equal to or less than 1 μm, or equal to or less than 0.5 μm.

[0082] As used herein, the singular terms "a", "an" and "the" may include plural referents unless the context clearly dictates otherwise. In the description of some embodiments, a component provided "on" or "over" another component may encompass the case where the former component is directly on (e.g., physically in contact with) the latter component, as well as the case where one or more intermediate components are located between the former component and the latter component.

[0083] As used herein, spatially relative terms such as "below," "below," "lower," "above," "upper," "lower," "left," "right," etc. may be used herein for ease of description to describe the relationship of one component or feature to another component or feature as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly. It should be understood that when a component is referred to as being "connected to" or "coupled to" another component, it may be directly connected or coupled to the other component, or intervening components may be present.

[0084] The foregoing summarizes several embodiments and detailed features of the present disclosure. The embodiments described in the present disclosure can be easily used as a basis for designing or modifying other processes and structures for performing the same or similar purposes and / or obtaining the same or similar advantages of the embodiments introduced herein. These equivalent constructions do not depart from the spirit and scope of the present disclosure and various changes, substitutions and modifications may be made without departing from the spirit and scope of the present disclosure.

Claims

1. A plasma coating device, characterized in that: include: An evaporation source assembly configured to carry a target material and ionize a surface of the target material by arc discharge to generate a coating particle flow; as well as The secondary ionization electrode device is disposed between the evaporation source assembly and the workpiece to be coated, and is configured to perform arc discharge on the coating particle flow flowing through the secondary ionization electrode device to further heat and ionize the metal droplets in the coating particle flow.

2. The plasma coating equipment according to claim 1, characterized in that: The secondary ionization electrode device comprises: The first electrode and the second electrode are connected to two poles of a power source respectively, and the first electrode and the second electrode include teeth that are staggered and arranged in parallel.

3. The plasma coating equipment according to claim 2, characterized in that: The intervals between adjacent teeth are the same.

4. The plasma coating equipment according to claim 2, characterized in that: The overlapping areas of two adjacent tooth-shaped portions are equal.

5. The plasma coating equipment according to claim 2, characterized in that: The overlapping area of ​​two adjacent tooth-shaped portions decreases from the center to the edge of the first electrode and the second electrode.

6. The plasma coating equipment according to claim 2, characterized in that: The secondary ionization electrode device includes a plurality of electrode pairs consisting of the first electrodes and the second electrodes, and the plurality of electrode pairs are arranged in different planes.

7. The plasma coating equipment according to claim 6, characterized in that: In two adjacent pairs of the electrode pairs, the position of the first electrode of one group of the electrode pairs corresponds to the position of the second electrode of the other group of the electrode pairs.

8. The plasma coating equipment according to claim 2, characterized in that: The distance from the center to the edge of the first electrode and the second electrode is greater than the distance from the target to the workpiece to be coated.

9. The plasma coating equipment according to claim 2, characterized in that: The distance between the target material and the workpiece to be coated is L, and the distance between the secondary ionization electrode device and the target material is D, wherein 0.25L≤D≤0.75L is satisfied.

10. The plasma coating equipment according to claim 2, characterized in that: The secondary ionization electrode device also includes: The position adjustment device is connected to one end of the first electrode and the second electrode and is configured to adjust the position of the first electrode and the second electrode between the evaporation source assembly and the workpiece to be coated.

11. The plasma coating equipment according to claim 10, characterized in that: The position adjustment device includes a retractable connecting rod and a driving device. The retractable connecting rod extends in a vertical direction. One end of the retractable connecting rod is connected to the first electrode and the second electrode, and the other end of the retractable connecting rod is connected to the driving device.

12. The plasma coating equipment according to claim 2, characterized in that: The first electrode and the second electrode include a conductive material having a temperature resistance of 2500° C. or more.

13. The plasma coating equipment according to claim 2, characterized in that: The first electrode and the second electrode include hafnium, tungsten, tantalum, graphite, conductive boron nitride or conductive silicon nitride.

14. The plasma coating equipment according to claim 2, characterized in that: The first electrode and the second electrode include metal pipes through which cooling water flows.

15. The plasma coating device according to any one of claims 2 to 14, characterized in that: The evaporation source assembly comprises: An arc limiting ring, disposed around the target and configured to limit the arc on the surface of the target; The auxiliary electrode and the target are respectively connected to two poles of an arc power source, and the auxiliary electrode is configured to adjust the coating effect by changing the relative position between the auxiliary electrode and the target.

16. The plasma coating equipment according to claim 15, characterized in that: The auxiliary electrode includes a plurality of sub-electrodes, and the arrangement configuration of the plurality of sub-electrodes constitutes the appearance of the auxiliary electrode.

17. The plasma coating equipment according to claim 16, characterized in that: The evaporation source assembly further includes a control device connected between the auxiliary electrode and the arc power source, and configured to selectively control the auxiliary electrode to operate in a first mode, a second mode, or a third mode.

18. The plasma coating equipment according to claim 17, characterized in that: When operating in the first mode, the control device controls the auxiliary electrode and the surface of the target material to be located in the same plane.

19. The plasma coating equipment according to claim 18, characterized in that: When operating in the first mode, the control device controls the plurality of sub-electrodes to be arranged in a ring shape, so that the auxiliary electrode forms a ring structure surrounding the arc-limiting ring.

20. The plasma coating equipment according to claim 18, characterized in that: When operating in the first mode, the arc power supply provides an arc current in the range of 60-300A.

21. The plasma coating equipment according to claim 17, characterized in that: When operating in the second mode, the control device controls the auxiliary electrode to be located between the target and the secondary ionization electrode device, and the vertical distance between the auxiliary electrode and the target is smaller than the diameter of the target.

22. The plasma coating equipment according to claim 21, characterized in that: The control device controls the plurality of sub-electrodes to be arranged in a ring shape, so that the projection of the auxiliary electrode on the plane where the arc-limiting ring is located forms a ring structure surrounding the arc-limiting ring.

23. The plasma coating device according to claim 21, characterized in that: The control device controls the plurality of sub-electrodes to gather together so that the auxiliary electrode forms a rod-shaped structure, and the rod-shaped structure is coaxial with the central axis of the target material.

24. The plasma coating equipment according to claim 21, characterized in that: When operating in the second mode, the arc power supply provides an arc current in the range of 300-600A.

25. The plasma coating equipment according to claim 17, characterized in that: When operating in the third mode, the control device controls the auxiliary electrode to be located between the target and the secondary ionization electrode device, and the vertical distance between the auxiliary electrode and the target is greater than the diameter of the target.

26. The plasma coating equipment according to claim 25, characterized in that: The control device controls the plurality of sub-electrodes to be arranged in a ring shape, so that the projection of the auxiliary electrode on the plane where the arc-limiting ring is located forms a ring structure surrounding the arc-limiting ring.

27. The plasma coating equipment according to claim 25, characterized in that: The control device controls the plurality of sub-electrodes to gather together so that the auxiliary electrode forms a rod-shaped structure, and the rod-shaped structure is coaxial with the central axis of the target material.

28. The plasma coating equipment according to claim 25, characterized in that: When operating in the third mode, the arc power supply provides an arc current in the range of 600-800A.

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