Plasma plating apparatus

Abstract

A plasma plating apparatus (10), comprising: an evaporation source assembly (11) and a secondary ionization electrode device (12). The evaporation source assembly (11) is configured to carry a target material (TR) and ionize a surface of the target material (TR) in an arc discharge manner to produce a plating particle flow (LR). The secondary ionization electrode device (12) is arranged between the evaporation source assembly (11) and a workpiece to be plated (X). The secondary ionization electrode device (12) is configured to perform arc discharge on the plating particle flow (LR) flowing through the secondary ionization electrode device (12), so as to further heat and ionize metal droplets in the plating particle flow (LR).

Description

Plasma coating equipment 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] Traditional multi-arc ion plating technology uses arc discharge on the target surface to achieve a single-step process of material vaporization and ionization. However, during this process, the arc discharge creates a molten pool on the target surface, leading to transient evaporation and micro-explosions in the molten pool, causing some material to fly off the target surface in the form of droplets. These droplets are not ionized and cannot react with the reaction gases to produce the desired coating composition. Furthermore, these droplets are large in size and will cool and deposit on the product surface, disrupting the coating's density and affecting its roughness.

[0003] Summary of the Invention

[0004] In view of this, the present application provides a plasma coating device to solve the above problems.

[0005] According to an embodiment of the present application, a plasma coating apparatus is provided, comprising: an evaporation source assembly and a secondary ionization electrode device. The evaporation source assembly is configured to carry a target material and ionize the surface of the target material by arc discharge to generate a coating particle stream. The secondary ionization electrode device is disposed between the evaporation source assembly and a workpiece to be coated. The secondary ionization electrode device is configured to generate an arc discharge on the coating particle stream flowing through the secondary ionization electrode device, thereby further heating and ionizing metal droplets in the coating particle stream.

[0006] In certain embodiments, the secondary ionization electrode assembly includes a first electrode and a second electrode, wherein the first electrode and the second electrode are connected to two poles of a power supply, respectively, and the first electrode and the second electrode include teeth arranged in an interlaced and parallel manner.

[0007] In some embodiments, the spacing between adjacent teeth is the same.

[0008] In some embodiments, the overlapping areas of two adjacent teeth are equal.

[0009] In some embodiments, the overlapping area of ​​two adjacent teeth decreases from the center to the edge of the first electrode and the second electrode.

[0010] 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.

[0011] In some embodiments, in two adjacent pairs of electrodes, the position of the first electrode of one electrode pair corresponds to the position of the second electrode of the other electrode pair.

[0012] In some embodiments, the distance from the center to the edge of the first electrode and the second electrode is greater than the distance between the target and the workpiece to be coated.

[0013] In some embodiments, the distance between the target and the workpiece to be coated is L, and the distance between the secondary ionization electrode device and the target is D, wherein 0.25L≤D≤0.75L is satisfied.

[0014] In some embodiments, the secondary ionization electrode assembly further includes a position adjustment device 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.

[0015] In some embodiments, the position adjustment device includes a retractable connecting rod and a drive 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 drive device.

[0016] In some embodiments, the first electrode and the second electrode include a conductive material having a temperature resistance of 2500° C. or higher.

[0017] In some embodiments, the first electrode and the second electrode include hafnium, tungsten, tantalum, graphite, conductive boron nitride, or conductive silicon nitride.

[0018] In certain embodiments, the first electrode and the second electrode include metal tubes through which cooling water flows.

[0019] In certain embodiments, the evaporation source assembly includes an arc-limiting ring and an auxiliary electrode. The arc-limiting ring is disposed around the target. The arc-limiting ring is configured to limit the arc on the target surface. The auxiliary electrode and the target are respectively connected to the two poles of an arc power supply. The auxiliary electrode is configured to adjust the coating effect by changing its relative position to the target.

[0020] In some embodiments, the auxiliary electrode includes a plurality of sub-electrodes, and the arrangement of the plurality of sub-electrodes constitutes the appearance of the auxiliary electrode.

[0021] In some embodiments, the evaporation source assembly further includes a control device connected between the auxiliary electrode and the arc power supply, configured to selectively control the auxiliary electrode to operate in a first mode, a second mode, or a third mode.

[0022] In some embodiments, when operating in the first mode, the control device controls the auxiliary electrode and the surface of the target to be located in the same plane.

[0023] 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.

[0024] In some embodiments, when operating in the first mode, the arc power supply provides an arc current in the range of 60-300A.

[0025] 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.

[0026] 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.

[0027] In some embodiments, the control device controls the multiple sub-electrodes to converge 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.

[0028] In some embodiments, when operating in the second mode, the arc power supply provides an arc current in the range of 301-600A.

[0029] 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.

[0030] 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.

[0031] In some embodiments, the control device controls the multiple sub-electrodes to converge 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.

[0032] In some embodiments, when operating in the third mode, the arc power supply provides an arc current in the range of 601-800A.

[0033] The plasma coating equipment proposed in this invention utilizes a secondary ionization electrode device to further heat, evaporate, and ionize the metal droplets in the coating particle stream, thereby enhancing the fineness of the coating. Furthermore, the placement of auxiliary electrodes allows for detailed adjustment of the desired coating effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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 detailed description, they are used to explain the present application but do not constitute a limitation of the present application. In the accompanying drawings:

[0035] FIG1 is a schematic diagram illustrating a plasma coating device according to an embodiment of the present application.

[0036] 2A and 2B respectively illustrate top views of the first electrode and the second electrode in two different states.

[0037] FIG3 illustrates a three-dimensional view of a secondary ionization electrode device according to an embodiment of the present application.

[0038] FIG4 is a schematic diagram illustrating a position adjustment device according to an embodiment of the present application.

[0039] 5A and 5B respectively illustrate schematic diagrams of auxiliary electrodes in two different states.

[0040] FIG. 6A is a schematic diagram illustrating an auxiliary electrode operating in a first mode according to an embodiment of the present application.

[0041] FIG. 6B is a schematic diagram illustrating the auxiliary electrode operating in the second mode according to an embodiment of the present application.

[0042] FIG. 6C is a schematic diagram illustrating the auxiliary electrode operating in the second mode according to an embodiment of the present application.

[0043] FIG. 6D is a schematic diagram illustrating the auxiliary electrode operating in the third mode according to an embodiment of the present application.

[0044] FIG. 6E is a schematic diagram illustrating the auxiliary electrode operating in the third mode according to an embodiment of the present application. DETAILED DESCRIPTION

[0045] 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 intended to simplify the present disclosure. As will be appreciated, these descriptions are illustrative only 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 in direct contact with each other; and may also include certain embodiments in which additional components are formed between the first and second features, such 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 for the purposes of brevity and clarity and does not, in itself, represent a relationship between the different embodiments and / or configurations discussed.

[0046] Furthermore, spatially relative terms such as "below," "beneath," "below," "above," and the like may be used herein to facilitate description of the relationship of one component or feature depicted in a figure relative to one or more other components or features. These spatially relative terms are intended to encompass various orientations of the device during use or operation, in addition to the orientation depicted in the figures. 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.

[0047] Although the numerical ranges and parameters used to define the broader scope of this application are approximate, the numerical values ​​of the specific examples have been presented herein as precisely as possible. However, any numerical value inherently and inevitably contains standard deviations resulting from individual testing methods. As used herein, "about" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specified value or range. Alternatively, the term "about" means that the actual value falls within an acceptable standard error of the mean, as determined by one of ordinary skill in the art. It should be understood that, except in the experimental examples, or unless otherwise expressly indicated, all ranges, amounts, values, and percentages used herein (e.g., to describe material amounts, time periods, temperatures, operating conditions, quantitative ratios, and the like) are modified by the word "about." Therefore, unless otherwise indicated, the numerical parameters disclosed in this specification and the appended claims are approximate and may be modified as needed. At a minimum, these numerical parameters should be understood to include the number of significant digits indicated and to apply normal rounding. 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.

[0048] In order to reduce the impact of droplets on the coating, the existing technology mainly adopts the technical methods of (1) suppressing the formation of droplets, or (2) filtering the droplet particles. Among the technologies for suppressing the formation of droplets, the common ones are: cooling the target surface temperature by cooling water to suppress 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.

[0049] However, these existing technologies all have their drawbacks. For example, cooling the target surface can cause excessive condensation on the device surface, which is detrimental to device stability. For example, reducing arc current intensity can also slow the evaporation rate of the target material, affecting the coating speed.

[0050] In view of this, the present application provides a plasma coating device to solve the above-mentioned technical problems. Figure 1 shows a schematic diagram of a plasma coating device 10 according to an embodiment of the present application. 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 component 11 and a secondary ionization electrode device 12. The evaporation source component 11 is connected to an arc power supply V2, and the evaporation source component 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.

[0051] In some embodiments, the secondary ionization electrode device 12 is disposed between the evaporation source assembly 11 and the workpiece X to be coated. The secondary ionization electrode device 12 is configured to generate an 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. Figures 2A and 2B respectively illustrate top views of the first electrode 121 and the second electrode 122 in two different configurations. 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.

[0052] In Figure 2A, each tooth-shaped portion 20 of the first electrode 121 and the second electrode 122 has the same length. With such a design, when the first electrode 121 and the second electrode 122 are staggered, the overall external contour area S1 is similar to a rectangle, and the overlapping area of ​​the two adjacent tooth-shaped portions 20 is equal. In Figure 2B, the tooth-shaped portions 20 of the first electrode 121 and the second electrode 122 located in the middle position are longer than the tooth-shaped portions 20 located at the edge position. With such a design, when the tooth-shaped portions of the first electrode 121 and the second electrode 122 are staggered, the overall external contour area S1 is similar to a circle, and the overlapping area of ​​the two adjacent tooth-shaped portions 20 located in the middle position is larger than the overlapping area of ​​the two adjacent tooth-shaped portions 20 located at the edge position. Figures 2A and 2B are only examples. This application does not limit the shapes of the first electrode 121 and the second electrode 122.

[0053] The first and second electrodes 121, 122 are connected to the two poles of a power source V1, respectively, forming an arc discharge between the first and second electrodes 121, 122. A tiny raised point on the surface initially acts as the arc starting point, causing the droplets deposited on the first and second electrodes 121, 122 to be further evaporated and ionized by the arc. The coating particle stream LR, which passes through but does not contact the first and second electrodes 121, 122, also forms a metal vapor arc between the first and second electrodes 121, 122, further heating, evaporating, and ionizing the metal droplets in the coating particle stream LR. Consequently, the droplet size gradually decreases, and the number of droplets decreases.

[0054] 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 surrounding the first electrode 121 and the second electrode 122 and is then deposited onto the surface of the coated product. The metal and gas atoms in the coating particle flow LR are also secondary ionized in this process, becoming metal ions and gas ions. The coating surface prepared in this manner is smoother, less rough, and has improved film quality and performance.

[0055] The actual total area of ​​the teeth 20 of the first and second electrodes 121, 122 should not be too large to avoid completely blocking the path of the coating particle flow LR. In some embodiments, the actual total area S2 of the teeth 20 of the first and second electrodes 121, 122 accounts for 40%-60% of the projected area S1 of the outer contours of the first and second electrodes 121, 122. In some embodiments, the distance B from the center to the edge of the first and second electrodes 121, 122 is greater than the distance L between the target TR and the workpiece X to be coated.

[0056] 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*PV2 , 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.

[0057] In some embodiments, the first electrode 121 and the second electrode 122 comprise a conductive material with a temperature resistance of 2500°C or higher. 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 comprise metal tubes through which cooling water flows.

[0058] 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. Referring to Figure 3, Figure 3 illustrates a three-dimensional view of the secondary ionization electrode device 12 according to an embodiment of the present application. In some embodiments, the secondary ionization electrode device 12 includes multiple groups of electrode pairs consisting of a first electrode 121 and a second electrode 122, which are respectively arranged in 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 area 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.

[0059] 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, 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, causing the coating on the workpiece to be coated X to 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 between the secondary ionization electrode device 12 and the target material TR is D, where 0.25L≤D≤0.75L is satisfied. Preferably, D=0.5L.

[0060] In some embodiments, in order to facilitate adjustment of the distance D between the secondary ionization electrode assembly 12 and the target material TR, the secondary ionization electrode assembly 12 further includes a position adjustment device 50. Referring to FIG4 , FIG4 illustrates a schematic diagram of a position adjustment device 50 according to an embodiment of the present application. 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 between the secondary ionization electrode assembly 12 and the target material TR. In some embodiments, the driving device 52 includes a stepping motor.

[0061] Referring again to 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 surrounds the target TR and is configured to limit the arc on the surface of the target TR. The auxiliary electrode 112 and the target TR are connected to the two poles of the arc power supply V2, respectively. The auxiliary electrode 112 is configured to adjust the coating effect by changing its relative position and appearance relative to the target TR.

[0062] In certain embodiments, the auxiliary electrode 112 includes multiple sub-electrodes 1121 (shown in Figures 5A and 5B ), wherein the arrangement of the multiple sub-electrodes 1121 defines the appearance of the auxiliary electrode 112. As shown in Figure 5A , when the multiple sub-electrodes 1121 are arranged in an open configuration, the auxiliary electrode 112 can form a ring-like structure. As shown in Figure 5B , when the multiple sub-electrodes 1121 are arranged in a close configuration, the auxiliary electrode 112 forms a rod-like structure.

[0063] 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 corresponding positions and have corresponding configurations to adjust the coating effect.

[0064] Figure 6A shows a schematic diagram of 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 multiple sub-electrodes 112 to be arranged so that the auxiliary electrode 112 becomes a ring structure as shown in Figure 5A and surrounds 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.

[0065] Figure 6B illustrates a schematic diagram of the auxiliary electrode 112 operating in the second mode according to an embodiment of the present application. In certain embodiments, when operating in the second mode, the control device controls the auxiliary electrode 112 to be positioned between the target TR and the secondary ionization electrode assembly 12, with the vertical distance D between the auxiliary electrode 112 and the target TR being less than the diameter of the target TR. In certain 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 forms a ring-shaped structure as shown in Figure 5A , with its projection on the plane of the arc-limiting ring 111 surrounding the arc-limiting ring 111. However, in other embodiments, referring to Figure 6C , when operating in the second mode, the control device may control the plurality of sub-electrodes 112 to converge so that the auxiliary electrode 112 forms a rod-shaped structure as shown in Figure 5B , with the auxiliary electrode 112 and the target's central axis TR being coaxial. In certain embodiments, when operating in the second mode, the arc current provided by the arc power supply V2 is in the range of 300-600 A. In certain embodiments, when operating in the second mode, the power factor K may be in the range of 0.9-1.3. Preferably, the power coefficient K may be in the range of 1.0-1.2.

[0066] Figure 6D illustrates a schematic diagram of the auxiliary electrode 112 operating in the third mode according to an embodiment of the present application. In certain embodiments, when operating in the third mode, the control device controls the auxiliary electrode 112 to be positioned between the target TR and the secondary ionization electrode assembly 12, with the vertical distance D between the auxiliary electrode 112 and the target TR being greater than the diameter of the target TR. In certain 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 forms a ring-shaped structure as shown in Figure 5A , with its projection on the plane of the arc-limiting ring 111 surrounding the arc-limiting ring 111. However, in other embodiments, referring to Figure 6E , when operating in the third mode, the control device may control the plurality of sub-electrodes 112 to converge so that the auxiliary electrode 112 forms a rod-shaped structure as shown in Figure 5B , with the auxiliary electrode 112 and the target's central axis TR being coaxial. In certain embodiments, when operating in the third mode, the arc current provided by the arc power supply V2 is in the range of 600-800 A. In certain embodiments, when operating in the third mode, the power factor K may be in the range of 1.1-1.5. Preferably, the power coefficient K may be in the range of 1.2-1.4.

[0067] The applicant conducted a series of experiments to verify the deposition rate and roughness of various combinations of the electrical parameters of the arc power source V2, the operating mode of the auxiliary electrode 112, the coefficient K of the secondary ionization electrode assembly 12, and the area ratio of S2 / S1. The parameters of various embodiments are listed in Table 1 below, and the experimental results are listed in Table 2 below.

[0068] Table 1

[0069] Table 2

[0070] Comparison of the experimental results of Examples 1 and 3, 14 and 16, 22 and 26, and Control Groups 1 and 2 shows that in the first mode, when the arc current is the same, although the coating rates of Examples 1 and 3 are approximately 80% of those of Control Groups 1 and 2, the coating roughness is significantly improved, with the roughness being less than 0.1 μm. In the second mode, the coating rate is significantly improved, with the roughness being approximately 0.15 to 0.21 μm. In the third mode, the coating rate is significantly improved, with the roughness being approximately 0.28 to 0.39 μm.

[0071] Comparison of the experimental results of Examples 11 and 13 shows that, under the same conditions, the first mode produces a lower coating roughness than the second mode, but a slower coating rate. Comparison of the experimental results of Examples 18 and 22 shows that, under the same conditions, the second mode produces a lower coating roughness than the third mode, but a slower coating rate.

[0072] From the comparison of the experimental results of Examples 2-6, 15-19 and 21-25, it can be seen that, regardless of operating in the first mode, the second mode or the third mode, the larger the power coefficient K, the faster the coating rate and the lower the roughness.

[0073] 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.

[0074] 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 is; conversely, the farther away from the target material TR, the lower the roughness is.

[0075] 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.

[0076] As used herein, the terms "approximately," "substantially," "substantially," and "about" are used to describe and take into account 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. As used herein with respect to a given value or range, the term "approximately" generally means within ±10%, ±5%, ±1%, or ±0.5% of the given value or range. Ranges 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 that are positioned along the same plane within a few micrometers (μm), 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 value or characteristic that is "substantially" the same, the term may refer to a value that is within ±10%, ±5%, ±1%, or ±0.5% of the average of the stated values.

[0077] As used herein, the terms "approximately," "substantially," "essentially," 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, 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, two values ​​may be considered "substantially" or "approximately" the same if the difference between them is less than or equal to ±10% of the mean 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 of less than or equal to ±10° relative to 0°, 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" perpendicular 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°.

[0078] 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.

[0079] 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 both the case where the former component is directly on (e.g., physically in contact with) the latter component and the case where one or more intermediate components are located between the former and the latter component.

[0080] As used herein, spatially relative terms such as "below," "beneath," "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 should be interpreted accordingly. It should be understood that when a component is referred to as being "connected to" or "coupled to" another component, it can be directly connected or coupled to the other component or intervening components may be present.

[0081] The foregoing summarizes several embodiments and detailed features of the present disclosure. The embodiments described in this disclosure can be readily 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, Comprising: An evaporation source assembly configured to carry a target and ionize the surface of the target by arc discharge to generate a coating particle stream; And A secondary ionization electrode device disposed between the evaporation source assembly and the workpiece to be coated, configured to perform arc discharge on the coating particle stream flowing through the secondary ionization electrode device to further heat and ionize the metal droplets in the coating particle stream.

2. The plasma coating equipment according to claim 1, characterized in that, The secondary ionization electrode device includes: A first electrode and a second electrode, respectively connected to two poles of a power supply, and the first electrode and the second electrode include tooth-shaped portions arranged in an interleaved and parallel manner.

3. The plasma coating equipment according to claim 2, characterized in that, The spacing between adjacent tooth-shaped portions is the same.

4. The plasma coating equipment according to claim 2, wherein The overlapping area of adjacent two tooth-shaped portions is equal.

5. The plasma coating equipment according to claim 2, characterized in that, The overlapping area of adjacent two 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 multiple groups of electrode pairs composed of the first electrode and the second electrode, and the multiple groups of electrode pairs are arranged on different planes.

7. The plasma coating equipment according to claim 6, characterized in that, In adjacent two 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 between the target and the workpiece to be coated.

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

10. The plasma coating equipment according to claim 2, wherein, The secondary ionization electrode device further includes: A position adjustment device connected to one end of the first electrode and the second electrode, configured to adjust the positions 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 telescopic connecting rod and a driving device, the telescopic connecting rod extends in the vertical direction, one end of the telescopic connecting rod is connected to the first electrode and the second electrode, and the other end of the telescopic 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 with a temperature resistance above 2500°C.

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, wherein The first electrode and the second electrode include a metal tube with internal circulating cooling water.

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

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

17. The plasma coating equipment according to claim 16, wherein, The evaporation source assembly further includes a control device connected between the auxiliary electrode and the arc power supply, 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 to be 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, wherein, When operating in the first mode, the arc current provided by the arc power supply is in the range of 60 - 300 A.

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 less 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 equipment according to claim 21, wherein The control device controls the plurality of sub-electrodes to converge, so that the auxiliary electrode forms a rod-shaped structure, and the rod-shaped structure is coaxial with the central axis of the target.

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

25. The plasma coating equipment according to claim 17, wherein 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 converge, so that the auxiliary electrode forms a rod-shaped structure, and the rod-shaped structure is coaxial with the central axis of the target.

28. The plasma coating equipment according to claim 25, wherein, When operating in the third mode, the arc current provided by the arc power supply is in the range of 600 - 800 A.

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