Coating apparatus and coating process for deep hole workpieces

Abstract

The application relates to a coating equipment for a deep-hole workpiece, which is used for coating a workpiece with a first through hole, and comprises a vacuum cavity, a magnetron cathode target, an ion acceleration concentrator and a workpiece rotating frame arranged in the vacuum cavity in sequence. The magnetron cathode target is connected with a high-power pulse power supply and used for generating first metal cations. The workpiece rotating frame can rotate around its own axis and is used for fixing the workpiece to be coated. The ion acceleration concentrator is used for generating second metal cations and accelerating the second metal cations and the first metal cations to form an ion beam which is sprayed along the extension direction of the first through hole. The second metal cations increase the overall concentration of the metal cations, and the first through hole is bombarded by the ion beam, so that the metal cation flux near the first through hole is increased, the coverage of the coating layer in the first through hole is improved, the energy of the metal cations is increased in the acceleration process, the adhesion of the coating layer is improved, the metal cations can penetrate into the first through hole, and the uniformity of the coating layer is improved.

Description

Technical Field

[0001] This application relates to the field of vacuum coating technology, and in particular to a coating equipment and coating process for deep hole workpieces. Background Technology

[0002] Depositing metal films on the surface of workpieces is one of the important means to improve workpiece performance. Current workpiece structures follow Moore's Law and are increasingly trending towards miniaturization and micro-miniaturization. When small workpieces have through holes, it is necessary to deposit metal films in the through holes with small diameters, especially those with a diameter of about 50 μm. In this case, the depth-to-diameter ratio of the through hole can be as high as 20:1, thus becoming a deep hole.

[0003] When using traditional physical vapor deposition (PVD) equipment to coat the through holes of the above-mentioned workpieces, the metal cations sprayed by the traditional PVD equipment cannot effectively enter the interior of the through holes, resulting in poor film coverage and uniformity, poor adhesion, and affecting the final quality of the workpiece. Summary of the Invention

[0004] Therefore, it is necessary to provide a coating equipment and coating process for deep-hole workpieces to address the problems of low film coverage, poor uniformity and poor adhesion caused by the deposition of deep-hole workpieces using traditional physical vapor deposition equipment.

[0005] A coating apparatus for deep-hole workpieces, used to coat a workpiece having a first through hole, characterized in that it comprises a vacuum chamber and a magnetron cathode target, an ion accelerator and a workpiece rotating frame sequentially arranged within the vacuum chamber, wherein:

[0006] The magnetron cathode target is connected to a high-power pulsed power supply to generate a first metal cation;

[0007] The workpiece rotating frame can rotate around its own axis to fix the workpiece to be coated;

[0008] The ion accelerator is used to generate a second metal cation and accelerate the second metal cation and the first metal cation to form an ion beam ejected along the extension direction of the first through hole.

[0009] The aforementioned coating equipment for deep-hole workpieces generates a second metal cation by setting up an ion acceleration and convergence device. This device then accelerates the second and first metal cations to form an ion beam that is sprayed along the extension direction of the first through-hole. On one hand, the collision-generated second metal cations increase the metal cation concentration, which is beneficial for improving the coverage of the deposited film sprayed into the first through-hole. On the other hand, accelerating the second and first metal cations increases their energy, allowing them to sputter deeper into the first through-hole, increasing the uniformity of the deposited film. Furthermore, the high-energy metal cations bombarding the coating site also improve the adhesion of the deposited film. Simultaneously, the convergence of the second and first metal cations to form an ion beam that bombards the inner wall of the first through-hole increases the ion beam flux in and around the first through-hole, ensuring that a large number of metal cations are reflected or deposited on the inner wall of the first through-hole, thus improving the coverage of the deposited film.

[0010] In one embodiment, the ion accelerator includes an insulating sleeve, a metal accelerating electrode, and a pulsed power supply, wherein:

[0011] The insulating sleeve is installed inside the vacuum cavity and is located between the magnetron cathode target and the workpiece rotating frame;

[0012] The metal accelerating electrode is disposed on the side of the insulating sleeve near the magnetron cathode target and is connected to the pulse power supply. The metal accelerating electrode is used to attract the first metal cation to accelerate towards itself and generate the second metal cation after colliding with itself. The material of the metal accelerating electrode is the same as that of the magnetron cathode target.

[0013] In one embodiment, the metal accelerating electrode includes metal electrode rings of progressively increasing size, with a plurality of metal electrode rings arranged in a concentric ring shape.

[0014] In one embodiment, the metal electrode ring has a circular structure.

[0015] In one embodiment, the ion accelerator further includes a first insulating connector, one end of which is connected to the metal accelerating electrode and the other end of which is connected to the insulating sleeve.

[0016] In one embodiment, the ion accelerator further includes an acceleration coil and a first adjustable power supply. The acceleration coil is disposed inside the insulating sleeve and connected to the first adjustable power supply. The acceleration coil is used to accelerate the first metal cation and the second metal cation input from the metal acceleration electrode.

[0017] In one embodiment, the ion accelerator further includes an electrode converging coil and a second adjustable power supply. The electrode converging coil is disposed inside the insulating sleeve and is located on the side of the accelerator coil away from the metal accelerator electrode. The electrode converging coil is used to generate a magnetic field to converge the first metal cation and the second metal cation input from the accelerator coil.

[0018] This application also provides a coating process, in which the coating equipment for deep hole workpieces described in any of the above embodiments is used to coat the workpiece to be coated, specifically including the following steps:

[0019] S1. A coating apparatus for a deep-hole workpiece and a workpiece to be coated are provided, the workpiece to be coated having a first surface and a second surface disposed opposite to each other and a first through hole penetrating the workpiece along the direction from the first surface to the second surface;

[0020] S2. Fix the workpiece to be coated onto the workpiece rotating frame so that the first surface faces the ion accelerator and convergent;

[0021] S3. Turn on the coating equipment for deep hole workpieces to perform vacuum coating on the first surface so that the first through hole has a first deposited film;

[0022] S4. Re-fix the workpiece to be coated onto the workpiece rotating frame so that the second surface faces the ion accelerator and convergent;

[0023] S5. The coating equipment for deep hole workpieces is turned on to perform vacuum coating on the second surface so that the first through hole has a second deposited film.

[0024] In one embodiment, the following step is further included before step S1 or between step S1 and step S2:

[0025] Clean the workpiece to be coated with at least one of the following solutions: acetone, ethanol and deionized water;

[0026] The workpiece to be coated is subjected to hydrogen plasma treatment using a plasma device to generate oxygen vacancies on the surface of the workpiece and the inner wall of the first through hole.

[0027] In one embodiment, the power of the plasma device is set to 200W-300W.

[0028] The aforementioned coating process employs a coating equipment specifically designed for deep-hole workpieces to perform double-sided coating, thereby ensuring that the concentration of metal cations on both sides of the inner wall of the first through-hole is nearly equal. This results in a more uniform film thickness on both sides of the inner wall of the first through-hole, improving the uniformity of the deposited film within the first through-hole. Furthermore, during the coating process, the coating equipment for deep-hole workpieces utilizes an ion acceleration and aggregation device to generate a second metal cation, which, along with the first metal cation, is accelerated to form an ion beam ejected along the extension direction of the first through-hole. On the one hand, increasing the concentration of metal cations is beneficial to improving the coverage of the deposited film layer sprayed into the first through hole; on the other hand, by accelerating the second and first metal cations to increase the energy of the metal cations, the metal cations can be sputtered deeper into the first through hole, increasing the uniformity of the deposited film. Furthermore, the bombardment of the deposited film site by high-energy metal cations also improves the adhesion of the deposited film layer. At the same time, the convergence of the second and first metal cations to form an ion beam to bombard the inner wall of the first through hole is beneficial to increasing the ion beam flux of the first through hole and the area near the first through hole, ensuring that a large number of metal cations are reflected or deposited on the inner wall of the first through hole, which also improves the coverage of the deposited film. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the coating equipment for deep-hole workpieces provided in this application.

[0030] Figure 2 This is a schematic diagram of the structure of the workpiece to be coated provided in this application.

[0031] Figure 3 for Figure 1 A cross-sectional view of the ion accelerator and convergent device.

[0032] Figure 4 for Figure 1 The structural diagram of the metal accelerating electrode in the image.

[0033] Figure 5 This is a schematic diagram showing the flow direction of metal cations in the ion accelerator provided in this application.

[0034] Figure 6 A flowchart of the coating process provided in this application.

[0035] in:

[0036] 10. Coating equipment for deep-hole workpieces; 20. Workpiece to be coated; 21. First through hole;

[0037] 100. Vacuum cavity;

[0038] 200. Magnetron-controlled cathode target; 210. First metal cation;

[0039] 300, Ion accelerator and concentrator; 310, Insulating sleeve; 320, Metal accelerating electrode; 321, Metal electrode ring; 322, Second metal cation; 330, Pulse power supply; 340, Accelerating coil; 350, First adjustable power supply; 360, Second insulating connector; 370, Electrode shoe concentrator coil; 380, Second adjustable power supply;

[0040] 400, workpiece rotating frame; 410, fixed shaft; 420, base plate. Detailed Implementation

[0041] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0042] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0047] See Figure 1 and Figure 2 As shown, Figure 1 This paper shows a schematic diagram of the structure of a coating apparatus 10 for deep-hole workpieces according to an embodiment of this application. Figure 2 A schematic diagram of the structure of a workpiece 20 to be coated is shown in one embodiment of this application. An embodiment of this application provides a coating apparatus 10 for deep-hole workpieces, used to coat a workpiece 20 having a first through hole 21. The apparatus includes a vacuum chamber 100 and a magnetron cathode target 200, an ion accelerator 300, and a workpiece rotating frame 400 sequentially arranged within the vacuum chamber 100. In a specific configuration, the two sides of the ion accelerator 300 are respectively positioned directly opposite the magnetron cathode target 200 and the workpiece rotating frame 400.

[0048] The magnetron cathode target 200 is connected to the high-power pulsed power supply 330. The magnetron cathode target 200 is used to generate the first metal cation 210. In specific settings, the magnetron cathode target 200 can be a copper target, a tungsten target, or other metal target materials required according to actual conditions, so that the magnetron cathode target 200 can be ionized to generate the corresponding first metal cation 210 for deposition onto the surface of the workpiece 20 to be coated. The workpiece carrier 400 can rotate around its own axis and is used to fix the workpiece 20 to be coated. In specific operation, the first through hole 21 is configured to face the ion accelerator and convergent device 300. In specific settings, the workpiece carrier 400 includes a fixed shaft 410 installed in the vacuum chamber 100 and a turntable sleeved outside the fixed shaft 410. The turntable can rotate around the fixed shaft 410 and has a plurality of spaced substrates 420, each substrate 420 for fixing one workpiece 20 to be coated. It should be noted that when the workpiece 20 to be coated is mounted on the substrate 420, the first through hole 21 needs to be aligned with the ion accelerator 300. The workpiece 20 to be coated can be made of materials such as glass or silicon wafer.

[0049] The ion accelerator 300 is used to generate a second metal cation 322 and accelerate the second metal cation 322 and the first metal cation 210 to form an ion beam ejected along the extension direction of the first through-hole 21. In a specific configuration, the second metal cation 322 and the first metal cation 210 are usually the same type of metal cation to increase the metal cation concentration and improve the coverage of the deposited film layer ejected into the first through-hole 21.

[0050] To ensure the rapid movement of the metal cations ejected by the ion accelerator 300 to the deposition site and thus improve the adhesion of the deposited film, the distance between the center of the ion accelerator 300 and the center of the workpiece 20 to be deposited is preferably between 1 cm and 10 cm. In this application, "metal cations" refers to the combined first metal cation 210 and second metal cation 322. To further enhance the adhesion of the deposited film, the workpiece carrier 400 is connected to a negative bias power supply. The negative bias applied by the power supply increases the energy of the metal cations within the chamber, allowing the high-energy metal cations to bombard the surface of the workpiece 20 and improve the adhesion of the deposited film.

[0051] The aforementioned coating equipment 10 for deep-hole workpieces generates a second metal cation 322 by setting an ion acceleration and focusing device 300, and accelerates the second metal cation 322 and the first metal cation 210 to form an ion beam sprayed along the extension direction of the first through-hole 21. On the one hand, the second metal cation 322 obtained by collision increases the metal cation concentration, which is beneficial to improving the coverage of the deposited film layer sprayed into the first through-hole 21; on the other hand, by accelerating the second metal cation 322 and the first metal cation 210 to increase the energy of the metal cations, the metal cations can be sputtered deeper into the interior of the first through-hole 21, increasing the uniformity of the deposited film, and the high-energy metal cations bombarding the coating site also improve the adhesion of the deposited film layer; at the same time, the convergence of the second metal cation 322 and the first metal cation 210 to form an ion beam to bombard the inner wall of the first through-hole 21 is beneficial to increase the ion beam flux of the first through-hole 21 and the area near the first through-hole 21, ensuring that a large number of metal cations are reflected or deposited on the inner wall of the first through-hole 21, thereby improving the coverage of the deposited film.

[0052] It should be emphasized that the coating equipment 10 for deep-hole workpieces in this application has a simple overall structure, is easy to promote, and is convenient for industrial production. Furthermore, the deposited film formed using the coating equipment 10 for deep-hole workpieces in this application has two advantages: firstly, strong adhesion, achieving 5B in cross-cut adhesion testing; and secondly, high coverage, allowing complete electrical conductivity of the inner wall of the first through-hole 21 through the metal deposition film. This enables its use in 2.5D / 3D chip packaging technology, and also in heat dissipation microchannel technology, further reducing the overall temperature of the chip.

[0053] Combination Figure 3 As shown, Figure 3 It shows Figure 1 A cross-sectional view of the ion accelerator 300. In some embodiments, in order to facilitate the generation of the second metal cation 322 by the ion accelerator 300, a preferred embodiment includes an insulating sleeve 310, a metal accelerating electrode 320 and a pulse power supply 330.

[0054] An insulating sleeve 310 is installed inside the vacuum chamber 100, positioned between the magnetron cathode target 200 and the workpiece rotating frame 400. Specifically, the insulating sleeve 310 is directly opposite both the magnetron cathode target 200 and the workpiece rotating frame 400, and the workpiece 20 to be coated overlaps with the insulating sleeve 310 within its orthogonal projection area on the workpiece rotating frame 400. A metal accelerating electrode 320 is positioned on the side of the insulating sleeve 310 closest to the magnetron cathode target 200, specifically directly opposite the magnetron cathode target 200, and connected to a pulse power supply 330. The metal accelerating electrode 320 attracts the first metal cation 210, accelerates it towards itself, and generates a second metal cation 322 after colliding with itself. The metal accelerating electrode 320 is made of the same material as the magnetron cathode target 200, so that the second metal cation 322 and the first metal cation 210 are the same type of metal cation to increase the metal cation concentration and improve the coverage of the deposited film layer sprayed into the first through hole 21.

[0055] In specific operation, the pulse signal applied to the metal accelerating electrode 320 by the pulse power supply 330 is the same as the pulse signal on the magnetron cathode target 200. This facilitates the attraction and acceleration of the first metal cation 210 generated by the magnetron cathode target 200 by the metal accelerating electrode 320. Then, the cation 210 collides with the metal accelerating electrode 320 to generate more metal cations of the same material. Subsequently, the metal cations in the vacuum chamber 100 pass through the metal accelerating electrode 320 and move along the extension direction of the insulating sleeve 310 before being sprayed onto the workpiece 20 to be coated.

[0056] Combination Figure 4 As shown, Figure 4 for Figure 1 The structural diagram of the metal accelerating electrode 320 is shown. In some embodiments, to facilitate the passage of the first metal cation 210 and the second metal cation 322 through the metal accelerating electrode 320, the metal accelerating electrode 320 specifically includes metal electrode rings 321 with progressively increasing sizes, and multiple metal electrode rings 321 are arranged in a concentric ring shape. It should be noted that the metal electrode rings 321 can be various geometric ring structures such as rectangular rings, elliptical rings, and polygonal rings. In this application, the metal electrode rings 321 are preferably circular ring structures. In a specific arrangement, the radius of the outermost circular metal electrode ring 321 is between 5 cm and 10 cm, and the distance between two adjacent circular metal electrode rings 321, i.e., the radius difference, is between 2 mm and 5 mm.

[0057] To facilitate the connection between the metal accelerating electrode 320 and the insulating sleeve 310, the ion accelerator 300 further includes a first insulating connector. One end of the first insulating connector is connected to the metal accelerating electrode 320, and the other end is connected to the insulating sleeve 310. In specific configurations, the first insulating connector can be made of insulating materials such as ceramic or plastic.

[0058] To facilitate the acceleration of the first metal cation 210 and the second metal cation 322, the ion accelerator 300 specifically includes an accelerating coil 340 and a first adjustable power supply 350. The accelerating coil 340 is disposed inside the insulating sleeve 310 and connected to the first adjustable power supply 350. The accelerating coil 340 is used to accelerate the first metal cation 210 and the second metal cation 322 input from the metal accelerating electrode 320. In a specific configuration, the accelerating coil 340 is fixed to the insulating sleeve 310 via a second insulating connector 360, and the accelerating coil 340 is circularly arranged. For ease of design of the accelerating coil 340 and the insulating sleeve 310, the radius of the accelerating coil 340 is preferably between 5 cm and 20 cm, the height of the accelerating coil 340 is preferably between 5 cm and 10 cm, and the wall thickness of the insulating sleeve 310 is preferably between 1 mm and 10 mm.

[0059] Combination Figure 5 As shown, Figure 5 The diagram shows the flow direction of metal cations in an ion accelerator 300 according to one embodiment of this application. In some embodiments, in order to more conveniently achieve the aggregation of the first metal cation 210 and the second metal cation 322, more specifically, the ion accelerator 300 also includes an electrode shoe converging coil 370 and a second adjustable power supply 380. The electrode shoe converging coil 370 is disposed inside the insulating sleeve 310 and is located on the side of the acceleration coil 340 away from the metal acceleration electrode 320. The electrode shoe converging coil 370 is used to generate a magnetic field to converge the first metal cation 210 and the second metal cation 322 input from the acceleration coil 340, so that the first metal cation 210 and the second metal cation 322 are sprayed onto the workpiece 20 to be coated in the form of an ion beam.

[0060] With the above settings, compared with the isotropic deposition method of sputtering atoms in the existing magnetron sputtering technology, the metal cations ejected by the ion accelerator 300 of this application have greater kinetic energy and directionality, which can increase the ion flux at the first through hole 21, so that more deposition film is deposited on the inner wall of the first through hole 21, thereby increasing the thickness of the inner wall film. In addition, the metal cations with higher kinetic energy have a greater average degree of freedom, and can undergo multiple collisions and migrations on the inner wall, ensuring that the coating is uniform and dense.

[0061] In the specific setup, the pole shoe converging coil 370 is fixed to the insulating sleeve 310 via a third insulating connector. The pole shoe converging coil 370 is circular, with a radius between 5cm and 20cm and a height between 5cm and 10cm. It should be noted that during the coating process on the workpiece 20, argon and nitrogen gases are introduced into the vacuum chamber 100, making it easier for metal cations to expand and form a film on the surface of the workpiece 20. Based on this, the pole shoe converging coil 370 and the accelerating coil 340 are designed to be fixed inside the insulating sleeve 310, so that the first metal cation 210 and the second metal cation 322 are not affected by external plasma during the convergence and acceleration process, thereby improving the convergence efficiency.

[0062] Combination Figure 6 As shown, Figure 6 The diagram shows a flow chart of a coating process according to an embodiment of this application. The coating process provided in this embodiment uses the coating equipment 10 for deep hole workpieces described in any of the above embodiments to coat the workpiece 20 to be coated, and specifically includes the following steps:

[0063] Step S1: Provide a coating apparatus 10 for deep hole workpieces and a workpiece 20 to be coated. The workpiece 20 to be coated has a first surface and a second surface arranged opposite to each other and a first through hole 21 penetrating the workpiece 20 along the direction from the first surface to the second surface. The depth-to-diameter ratio of the first through hole 21 can be as high as 20:1.

[0064] Step S2: Fix the workpiece 20 to be coated onto the workpiece rotating frame 400 so that the first surface faces the ion accelerator concentrator 300. In a specific setting, the workpiece 20 to be coated is fixed to the substrate 420, and the workpiece rotating frame 400 is in a rotating state. The first surface of each workpiece 20 to be coated is directly facing the pole shoe concentrating coil 370 in the ion accelerator concentrator 300, which is conducive to the ion beam ejected from the pole shoe concentrating coil 370 bombarding the first surface and the inner wall of the first through hole 21 with an opening on the first surface.

[0065] Step S3: Turn on the coating equipment 10 for deep hole workpieces to perform vacuum coating on the first surface so that the first through hole 21 has a first deposited film. It should be noted that when vacuum coating is performed on the first surface, the part of the first through hole 21 closer to the first surface has more first deposited film.

[0066] To obtain a uniform deposited film within the first through-hole 21, step S4 involves re-fixing the workpiece 20 to be coated onto the workpiece carrier 400 so that the second surface faces the ion accelerator 300, similar to step S2 in specific operation. Then, step S5 involves activating the coating equipment 10 for deep-hole workpieces to perform vacuum coating on the second surface, resulting in a second deposited film on the first through-hole 21. With these settings, under the same parameter settings, the thickness of the first deposited film on one side of the first through-hole 21 and the second deposited film on the other side of the first through-hole 21 tend to be the same, thus making the thickness of the deposited film on both sides of the inner wall of the first through-hole 21 tend to be the same, improving the uniformity of the deposited film within the first through-hole 21.

[0067] The above-described coating process employs a coating equipment 10 for deep-hole workpieces to perform double-sided coating on the workpiece 20 to be coated. This makes the concentration of metal cations on both sides of the inner wall of the first through-hole 21 tend to be the same, thereby making the thickness of the deposited film on both sides of the inner wall of the first through-hole 21 tend to be the same, improving the uniformity of the deposited film within the first through-hole 21. Furthermore, during the coating process, the coating equipment 10 for deep-hole workpieces generates a second metal cation 322 by setting an ion acceleration and convergence device 300, and accelerates the second metal cation 322 and the first metal cation 210 to form an ion beam ejected along the extension direction of the first through-hole 21. On the one hand, increasing the concentration of metal cations is beneficial to improving the coverage of the deposited film layer sprayed into the first through-hole 21; on the other hand, by accelerating the second metal cation 322 and the first metal cation 210 to increase the energy of the metal cations, the metal cations can be sputtered deeper into the interior of the first through-hole 21, increasing the uniformity of the deposited film. Furthermore, the bombardment of the deposited film site by high-energy metal cations also improves the adhesion of the deposited film layer. At the same time, the convergence of the second metal cation 322 and the first metal cation 210 to form an ion beam to bombard the inner wall of the first through-hole 21 is beneficial to increase the ion beam flux of the first through-hole 21 and the area near the first through-hole 21, ensuring that a large number of metal cations are reflected or deposited on the inner wall of the first through-hole 21, which also improves the coverage of the deposited film.

[0068] In order to obtain a clean workpiece 20 to be coated before coating, in a preferred embodiment, the following step is further included before step S1 or between step S1 and step S2:

[0069] The workpiece 20 to be coated can be cleaned first with at least one of acetone, ethanol and deionized water; then, hydrogen plasma treatment is performed on the workpiece 20 to be coated using a plasma device to generate oxygen vacancies on the surface of the workpiece 20 and the inner wall of the first through hole 21.

[0070] It should be noted that the current method for cleaning the workpiece 20 to be coated is to use argon plasma to clean the stains and dust on the surface of the workpiece 20. However, in this application, when cleaning the workpiece 20, hydrogen plasma or a mixture of hydrogen plasma and argon plasma is used to treat the workpiece 20. The hydrogen plasma generates a certain concentration of oxygen vacancies on the surface of the workpiece 20, enhancing the bonding ability between metal cations and the workpiece 20. In addition, a small amount of hydrogen plasma is injected into the surface of the workpiece 20, attracting negatively charged metal ions and increasing the coating thickness.

[0071] To improve the cleaning effect on the workpiece 20 to be coated, the power of the plasma equipment is specifically set to 200W-300W. The cleaning time is set to 20 min to 90 min. In specific operation, hydrogen or a mixture of argon and hydrogen is introduced into the plasma equipment to ionize hydrogen plasma and argon plasma for cleaning the workpiece 20. When a mixture of argon and hydrogen is introduced, the preferred ratio of argon to hydrogen is 5:1.

[0072] When the coating equipment 10 for deep-hole workpieces is turned on to perform vacuum coating on the first or second surface, the specific steps include: evacuating the vacuum chamber 100 to a vacuum level below 1×10⁻³ Pa; introducing a working gas into the vacuum chamber 100, specifically a mixture of argon and nitrogen, preferably in a ratio of 20:1, to achieve a working pressure of 0.1 Pa to 10 Pa; turning on the negative bias power supply and setting the negative bias to 700 V to 900 V; turning on the high-power pulse power supply 330, setting the peak voltage of the high-power pulse power supply 330 to 700 V to 1000 V, and setting the pulse width of the high-power pulse power supply 330 to 30 Hz. The pulse width is set to 50μs~200μs, and the frequency of the high-power pulse power supply 330 is set to 50kHz~300kHz. The pulse power supply 330 is turned on, and its negative bias voltage is set to 500V~700V. The pulse width is set to 50μs~300μs, and the frequency is set to 50kHz~300kHz. The phase lag of the pulse power supply 330 behind the high-power pulse power supply 330 is 50μs~150μs. The first adjustable power supply 350 is turned on, and its power is set to 300W~700W. The second adjustable power supply 380 is turned on, and its power is set to 300W~700W. The coating time for the first and second surfaces is set to 1000s~7000s.

[0073] To simplify the description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A coating apparatus for a deep hole workpiece, for coating a workpiece having a first through hole, characterized by, It includes a vacuum chamber and a magnetron cathode target, an ion accelerator and a workpiece turntable sequentially arranged within the vacuum chamber, wherein: The magnetron cathode target is connected to a high-power pulsed power supply to generate a first metal cation; The workpiece rotating frame can rotate around its own axis to fix the workpiece to be coated; The ion accelerator is used to generate a second metal cation and accelerate the second metal cation and the first metal cation to form an ion beam that is ejected along the extension direction of the first through hole. The ion accelerator includes an insulating sleeve, a metal accelerating electrode, and a pulsed power supply, wherein: The insulating sleeve is installed inside the vacuum cavity and is located between the magnetron cathode target and the workpiece rotating frame; The metal accelerating electrode is disposed on the side of the insulating sleeve near the magnetron cathode target and is connected to the pulse power supply. The metal accelerating electrode is used to attract the first metal cation to accelerate towards itself and generate the second metal cation after colliding with itself. The material of the metal accelerating electrode is the same as that of the magnetron cathode target. The ion accelerator further includes an acceleration coil and a first adjustable power supply. The acceleration coil is disposed inside the insulating sleeve and connected to the first adjustable power supply. The acceleration coil is used to accelerate the first metal cation and the second metal cation input from the metal acceleration electrode. The ion accelerator further includes an electrode converging coil and a second adjustable power supply. The electrode converging coil is disposed inside the insulating sleeve and is located on the side of the accelerator coil away from the metal accelerator electrode. The electrode converging coil is used to generate a magnetic field to converge the first metal cation and the second metal cation input from the accelerator coil.

2. The coating apparatus for a deep hole workpiece according to claim 1, wherein The metal accelerating electrode includes metal electrode rings with progressively increasing sizes, and the plurality of metal electrode rings are arranged in a concentric ring shape.

3. The coating apparatus for a deep hole workpiece according to claim 2, wherein The metal electrode ring has a circular ring structure.

4. The coating apparatus for a deep hole workpiece according to claim 1, wherein The ion accelerator further includes a first insulating connector, one end of which is connected to the metal accelerating electrode and the other end of which is connected to the insulating sleeve.

5. A coating process characterized by: The coating equipment for deep-hole workpieces according to any one of claims 1-4 is used to coat the workpiece to be coated, specifically including the following steps: S1. A coating apparatus for a deep-hole workpiece and a workpiece to be coated are provided, the workpiece to be coated having a first surface and a second surface disposed opposite to each other and a first through hole penetrating the workpiece along the direction from the first surface to the second surface; S2. Fix the workpiece to be coated onto the workpiece rotating frame so that the first surface faces the ion accelerator and convergent; S3. Turn on the coating equipment for deep hole workpieces to perform vacuum coating on the first surface so that the first through hole has a first deposited film; S4. Re-fix the workpiece to be coated onto the workpiece rotating frame so that the second surface faces the ion accelerator and convergent; S5. The coating equipment for deep hole workpieces is turned on to perform vacuum coating on the second surface so that the first through hole has a second deposited film.

6. The coating process according to claim 5, characterized in that, Before step S1 or between step S1 and step S2, the following steps are also included: Clean the workpiece to be coated with at least one of the following solutions: acetone, ethanol and deionized water; The workpiece to be coated is subjected to hydrogen plasma treatment using a plasma device to generate oxygen vacancies on the surface of the workpiece and the inner wall of the first through hole.

7. The coating process according to claim 6, characterized in that, The power of the plasma device is set to 200W-300W.

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