A device for simultaneous cleaning and coating of the inner wall of a slender pipe and its application method

Abstract

A device for simultaneous cleaning and coating of the inner wall of a slender pipe and its method of use are disclosed, belonging to the field of surface treatment. It solves the problems of poor uniformity of coatings and difficulty in removing contaminants in existing slender pipe coatings. The device includes a power supply I, a water inlet pipe I, an air inlet pipe I, a water outlet pipe I, a flange I, a vacuum chamber, an air inlet I, a clamp I, a target I, a guide rail, a slider, a controller, a reciprocating motor, a pipe to be coated, an air extraction port, a target II, a clamp II, an air inlet II, a flange II, a water outlet II, an air inlet II, a water inlet pipe II, and a power supply II. This invention uses two adjacent short columnar targets to simultaneously perform cleaning and coating inside the slender pipe, ensuring the cleanliness of the coating area and the surface activity of the substrate; ensuring the uniformity of the deposited film; and avoiding contact contamination between the movable device and the inner wall of the pipe to be coated. The controller automatically controls the movement direction and speed of the pipe to be coated, as well as the polarity and parameters of the power supply, ensuring the stability and continuity of the process.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment, specifically relating to a device for simultaneous cleaning and coating of the inner wall of a slender pipe and its usage method. Background Technology

[0002] Surface treatment of the inner wall of slender pipes is a major challenge that urgently needs to be addressed. As pipes become thinner and longer, it becomes difficult for external plasma sources to penetrate and distribute evenly inside. Even with in-pipe discharge, the gas concentration becomes uneven with increasing pipe length. Research has shown that pure gas discharge within slender pipes exhibits significant pressure fluctuations over lengths exceeding 1 meter, resulting in substantial differences in the deposited film. In-pipe column-target discharge is a promising solution, but it also faces several problems. For example, long column-target deposition requires separate cleaning and coating processes, leading to prolonged process changeover times (requiring slow movement from the cleaning position to the coating position), which reduces substrate surface activity and increases the risk of secondary ignition and contamination after process changeover. Conversely, short-target mobile coating can cause "ash removal" in non-discharge areas, contaminating the substrate and reducing coating quality.

[0003] In addition, some scholars have used crawling robots to pull short cylindrical targets and air ducts for coating in long pipelines, but they still have not been able to solve the problem of continuity in the cleaning and coating process. At the same time, dust removal during coating will cause contamination in other areas, and the mechanical feet of the robot will contaminate the substrate during crawling, affecting the quality of the film. Summary of the Invention

[0004] This invention addresses the problems of difficulty in external plasma penetration, difficulty in ensuring uniformity of internal discharge plasma, discontinuous cleaning and coating processes, and substrate contamination caused by ash removal during existing coating processes inside slender pipes. It provides a device for synchronous cleaning and coating of the inner wall of slender pipes and its usage method.

[0005] A device for synchronous cleaning and coating of the inner wall of a slender pipe includes a power supply I, a water inlet pipe I, an air inlet pipe I, a water outlet pipe I, a flange I, a vacuum chamber, an air inlet I, a clamp I, a target I, a guide rail, a slider, a controller, a reciprocating motor, a pipe to be coated, an air extraction port, a target II, a clamp II, an air inlet II, a flange II, a water outlet II, an air inlet pipe II, a water inlet pipe II, and a power supply II.

[0006] The guide rail is fixed in the vacuum chamber, the tube to be plated is fixed on the slider, and the slider is driven by a reciprocating motor to drive the tube to be plated to reciprocate along the guide rail.

[0007] The water inlet pipe I, air inlet pipe I, water outlet pipe I, clamp I, target I, tube to be plated, clamp II, water outlet pipe II, air inlet pipe II and water inlet pipe II are coaxially installed. The air inlet pipe I has an air inlet hole I and the air inlet pipe II has an air inlet hole II.

[0008] Power supply I is electrically connected to the tube to be plated and target I, and power supply II is electrically connected to the tube to be plated and target II. The tube to be plated is at the same potential as the vacuum chamber. The polarity of power supply I and power supply II and the direction of movement of the tube to be plated are controlled by the controller.

[0009] Furthermore, the clamp I connects the air inlet pipe I, the water outlet pipe I, and the target I; the air inlet pipe I and the water outlet pipe I extend out of the vacuum chamber from the top of the vacuum chamber and are fixed to the outer wall of the vacuum chamber through the flange I;

[0010] Fixture II connects air inlet pipe II, water outlet pipe II, and target II; air inlet pipe II and water outlet pipe II extend out of the vacuum chamber from the bottom and are fixed to the outer wall of the vacuum chamber via flange II; air inlet pipe II and water outlet pipe II can move relative to flange I or flange II.

[0011] Furthermore, a gap is left between target I and target II, which can also be connected by an insulating clamp.

[0012] Furthermore, the lower part of the air inlet pipe I has air inlet holes I evenly distributed in a ring, and the upper part of the air inlet pipe II has air inlet holes II evenly distributed in a ring; the air extraction port is located on the side wall of the vacuum chamber.

[0013] Furthermore, the polarities of power supplies I and II are matched with the direction of movement of the tube to be plated via a controller:

[0014] When the tube to be coated moves towards the bottom of the vacuum chamber, the positive terminal of power supply I is connected to target I, and the negative terminal is used to clean the tube to be coated; the negative terminal of power supply II is connected to target II, and the positive terminal is used to deposit the tube to be coated.

[0015] When the tube to be coated moves toward the top of the vacuum chamber, the negative terminal of power supply I is connected to target I, and the positive terminal is connected to the tube to be coated for deposition; the positive terminal of power supply II is connected to target II, and the negative terminal is connected to the tube to be coated for cleaning.

[0016] Furthermore, when the controller switches the polarity of power supply I and power supply II and the direction of movement of the tube to be plated, it can simultaneously adjust the speed of the tube to be plated and the process parameters of power supply I and power supply II.

[0017] Furthermore, power supply I and power supply II are DC power supplies or bipolar power supplies; the tube to be plated is a magnetic or non-magnetic conductive material.

[0018] The above-mentioned method of using a synchronous cleaning and coating device for the inner wall of a slender pipe is implemented according to the following steps:

[0019] 1. Clean the tube to be plated with acetone and anhydrous ethanol in sequence using ultrasonic cleaning for 5-60 minutes, then remove, dry and fix it in a vacuum chamber.

[0020] 2. Evacuate the vacuum chamber to 8×10⁻⁶. -3Pa, introduce working gas and / or reaction gas and adjust the gas pressure to 0.01-20Pa, turn on power supply I, power supply II and reciprocating motor, set the movement direction and speed of the tube to be coated, as well as the polarity and discharge parameters of power supply I and power supply II through the controller, and perform synchronous cleaning and coating of the inner wall of the pipe.

[0021] 3. After the process is completed, turn off power supply I, power supply II and reciprocating motor, and wait for the tube to cool down to complete the coating of the inner wall of the slender pipe.

[0022] Furthermore, the working gas mentioned in step two is He, Ne, Ar, Kr, Xe, or Rn.

[0023] Furthermore, the reaction gas mentioned in step two is N2, H2, CH4, H2S, NH3, or O2.

[0024] Furthermore, the working gas and the reaction gas mentioned in step two are mixed in any ratio.

[0025] The advantages of this invention are:

[0026] 1. The device of this invention matches the discharge characteristics of two adjacent columnar targets with the movement direction of the tube to be coated, enabling continuous pre-cleaning followed by coating in localized areas within a slender pipe, while simultaneously ensuring the synchronous execution of the cleaning and coating processes within the slender pipe on a macroscopic level. Pre-cleaning of the area to be coated is achieved through pre-purging of the airflow at the inlet, combined with the target's cleaning function, improving the surface condition of the substrate in the deposition area and ensuring coating quality. Furthermore, by rationally controlling the cleaning parameters and the discharge intensity of the cleaning section, excessive sputtering etching of the substrate can be avoided.

[0027] 2. A major challenge in in-tube discharge lies in the difficulty of the discharge process itself. Narrow-pitch discharge requires extremely high gas pressure and voltage. The installation of strong magnets inside both targets effectively creates magnetic confinement on the cathode (the target used for deposition) or anode (the target used for cleaning), significantly reducing the difficulty of discharge. Simultaneously, the cleaning target also collects contaminants. By reversing the direction of the tube to be coated, the two targets are appropriately exposed in the vacuum chamber. Combined with the polarity of the two power supplies and process switching, after the targets are switched to deposition mode, the contaminants adsorbed on the surface during the previous cleaning stage are etched and discharged into the vacuum chamber, allowing the targets to enter the tube for subsequent deposition with clean surfaces. Furthermore, by rationally controlling the movement speed of the tube to be coated, excessive accumulation of contaminants on the cleaning target surface can be effectively avoided, ensuring surface conductivity and adsorption effects, and improving the coating environment inside the tube.

[0028] 3. By shortening the length of the columnar target, the difference in discharge intensity caused by uneven gas distribution in the slender pipe is avoided. At the same time, the processing difficulty and processing cost of the long columnar target during long pipe coating are greatly reduced, and the axial uniformity of the coating inside the pipe is guaranteed.

[0029] 4. The linear movement of the tube to be coated is driven by a motor, and the moving device is located outside the tube, which increases the space for operation and adjustment, ensures the stability of the device, and prevents contact between the coating device and the substrate, thus avoiding contamination of the surface to be coated.

[0030] 5. The method of continuous cleaning and coating using adjacent dual targets in this invention is also applicable to the surface treatment of inner walls of tubes and cylinders, the surface treatment of irregularly shaped parts, or the surface treatment of planar parts. Its surface treatment content is not only applicable to plasma etching cleaning and coating alone or in combination, but also applicable to surface treatment processes such as nitriding, carburizing, sulfiding, and oxidation. Only the target material form, movement path, discharge gas, and process parameters need to be adjusted accordingly.

[0031] The device of this invention is suitable for simultaneous cleaning and coating of the inner wall of slender pipes. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the synchronous cleaning and coating device for the inner wall of a slender pipe according to the present invention. In the diagram, 1-1 represents power supply I, 2-1 represents water inlet pipe I, 3-1 represents air inlet pipe I, 4-1 represents water outlet pipe I, 5-1 represents flange I, 6 represents vacuum chamber, 7-1 represents air inlet I, 8-1 represents clamp I, 9-1 represents target I, 10 represents guide rail, 11 represents slider, 12 represents controller, 13 represents reciprocating motor, 14 represents pipe to be coated, 15 represents air extraction port, 9-2 represents target II, 8-2 represents clamp II, 7-2 represents air inlet II, 5-2 represents flange II, 4-2 represents water outlet pipe II, 3-2 represents air inlet pipe II, 2-2 represents water inlet pipe II, and 1-2 represents power supply II.

[0033] Figure 2 This is a schematic diagram of the function of each part of the device when the tube to be plated moves to the top in Example 1;

[0034] Figure 3 This is a schematic diagram showing the function of each part of the device when the tube to be plated moves to the bottom in Example 1;

[0035] Figure 4 The images show the cross-sectional morphology of the Ti film deposited at different locations inside the carbon steel pipe in Example 1, where parts a, b, c, and d are arranged sequentially from the center of the pipe to the pipe opening.

[0036] Figure 5 The images show the cross-sectional morphology of the Cr film deposited at different locations inside the carbon steel pipe in Example 2, where parts a, b, c, d, and e are arranged sequentially from the center of the pipe to the pipe opening. Detailed Implementation

[0037] Specific implementation method one: as follows Figure 1As shown in the figure, this embodiment of a device for synchronous cleaning and coating of the inner wall of a slender pipe includes a power supply I1-1, a water inlet pipe I2-1, an air inlet pipe I3-1, a water outlet pipe I4-1, a flange I5-1, a vacuum chamber 6, an air inlet I7-1, a clamp I8-1, a target I9-1, a guide rail 10, a slider 11, a controller 12, a reciprocating motor 13, a pipe to be coated 14, an air extraction port 15, a target II9-2, a clamp II8-2, an air inlet II7-2, a flange II5-2, a water outlet pipe II4-2, an air inlet pipe II3-2, a water inlet pipe II2-2, and a power supply II1-2.

[0038] The guide rail 10 is fixed inside the vacuum chamber 6, and the tube to be plated 14 is fixed on the slider 11. The slider 11 is pulled by the reciprocating motor 13, which can drive the tube to be plated 14 to reciprocate along the guide rail 10.

[0039] The water inlet pipe I2-1, air inlet pipe I3-1, water outlet pipe I4-1, clamp I8-1, target I9-1, plated tube 14, clamp II8-2, water outlet pipe II4-2, air inlet pipe II3-2 and water inlet pipe II2-2 are coaxially installed. The air inlet pipe I3-1 has an air inlet hole I7-1 and the air inlet pipe II3-2 has an air inlet hole II7-2.

[0040] The power supply I1-1 is electrically connected to the tube to be plated 14 and the target I9-1, and the power supply II1-2 is electrically connected to the tube to be plated 14 and the target II9-2. The tube to be plated 14 is at the same potential as the vacuum chamber 6. The polarity of the power supply I1-1 and the power supply II1-2 and the direction of movement of the tube to be plated 14 are controlled by the controller 12.

[0041] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the clamp I8-1 is connected to the air inlet pipe I3-1, the water outlet pipe I4-1 and the target I9-1; the air inlet pipe I3-1 and the water outlet pipe I4-1 extend out of the vacuum chamber 6 from the top of the vacuum chamber 6 and are fixed to the outer wall of the vacuum chamber 6 by the flange I5-1.

[0042] Fixture II8-2 connects the air inlet pipe II3-2, the water outlet pipe II4-2, and the target II9-2; the air inlet pipe II3-2 and the water outlet pipe II4-2 extend from the bottom of the vacuum chamber 6 and are fixed to the outer wall of the vacuum chamber 6 via flange II5-2; the air inlet pipe II3-2 and the water outlet pipe II4-2 can move relative to each other via flange I5-1 or flange II5-2. Other aspects are the same as in specific embodiment one.

[0043] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that a gap is left between target I 9-1 and target II 9-2, which can also be connected by an insulating clamp. Everything else is the same as in Specific Implementation Method One.

[0044] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the lower part of the air inlet pipe I3-1 has air inlet holes I7-1 evenly distributed in a ring, and the upper part of the air inlet pipe II3-2 has air inlet holes II7-2 evenly distributed in a ring; the exhaust port 15 is located on the side wall of the vacuum chamber 6. Everything else is the same as in Specific Implementation Method One.

[0045] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the polarity of power supply I1-1 and power supply II1-2 is matched with the movement direction of the tube to be plated 14 via controller 12.

[0046] When the tube to be coated 14 moves toward the bottom of the vacuum chamber 6, the positive terminal of power supply I1-1 is connected to target I9-1, and the negative terminal is connected to the tube to be coated 14 for cleaning. The negative terminal of power supply II1-2 is connected to target II9-2, and the positive terminal is connected to the tube to be coated 14 for deposition.

[0047] When the tube to be coated 14 moves toward the top of the vacuum chamber 6, the negative terminal of power supply I1-1 is connected to target I9-1, and the positive terminal is connected to the tube to be coated 14 for deposition; the positive terminal of power supply II1-2 is connected to target II9-2, and the negative terminal is connected to the tube to be coated 14 for cleaning. Everything else is the same as in specific embodiment one.

[0048] In this embodiment, due to the connection method of power supply I1-1 and power supply II1-2, a large potential difference is easily generated between them, which can cause abnormal discharge. However, this situation can be effectively avoided by performing phase matching on power supply I1-1 and power supply II1-2 or increasing the discharge difficulty between target I9-1 and target II9-2.

[0049] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that, when the controller 12 switches the polarity of power supply I1-1 and power supply II1-2 with the direction of movement of the tube to be plated 14, it can simultaneously adjust the movement speed of the tube to be plated 14 and the process parameters of power supply I1-1 and power supply II1-2. Everything else is the same as in Specific Implementation Method One.

[0050] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that the power supply I1-1 and power supply II1-2 are DC power supplies or bipolar power supplies; the tube to be plated 14 is made of magnetic or non-magnetic conductive material. Everything else is the same as in Specific Implementation Method One.

[0051] Specific Implementation Method Eight: This implementation method describes a method for using a synchronous cleaning and coating device for the inner wall of a slender pipe, which is achieved through the following steps:

[0052] 1. Clean the tube 14 to be plated with acetone and anhydrous ethanol in sequence for 5-60 minutes using ultrasonic cleaning, then remove, dry and fix it in the vacuum chamber 6.

[0053] 2. Evacuate vacuum chamber 6 to 8×10⁻⁶. -3Pa, introduce working gas and / or reaction gas and adjust the gas pressure to 0.01-20Pa, turn on power supply I1-1, power supply II1-2 and reciprocating motor 13, set the movement direction and speed of the tube to be coated 14, as well as the polarity and discharge parameters of power supply I1-1 and power supply II1-2 through the controller, and perform synchronous cleaning and coating of the inner wall of the pipe.

[0054] 3. After the process is completed, turn off the power supply I1-1, power supply II1-2 and reciprocating motor 13. After the coating tube 14 cools down, the coating of the inner wall of the slender pipe is completed.

[0055] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Eight in that the working gas in step two is He, Ne, Ar, Kr, Xe, or Rn. Everything else is the same as in Specific Implementation Method Eight.

[0056] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method Eight in that the reaction gas in step two is N2, H2, CH4, H2S, NH3, or O2. Everything else is the same as in Specific Implementation Method Eight.

[0057] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Method Eight in that the working gas and reactant gas in step two are mixed in any ratio. Everything else is the same as in Specific Implementation Method Eight.

[0058] The beneficial effects of the present invention are verified through the following embodiments:

[0059] Example 1:

[0060] A method for using a device for simultaneous cleaning and coating of the inner wall of a slender pipe, comprising the following steps:

[0061] 1. Clean the tube 14 to be plated by ultrasonic cleaning with acetone and anhydrous ethanol for 30 minutes in sequence, then take it out, dry it and fix it in the vacuum chamber 6.

[0062] 2. Evacuate vacuum chamber 6 to 8×10⁻⁶. -3 Pa, introduce Ar and adjust the air pressure to 1Pa, turn on power supply I1-1, power supply II1-2 and reciprocating motor 13, set the movement direction and speed of the tube to be coated 14, as well as the polarity and discharge parameters of power supply I1-1 and power supply II1-2 through the controller, and perform synchronous cleaning and coating of the inner wall of the pipe for 1 hour.

[0063] 3. After the process is completed, turn off the power supply I1-1, power supply II1-2 and reciprocating motor 13. After the coating tube 14 cools down, the coating of the inner wall of the slender pipe is completed.

[0064] The device used in this embodiment Figure 1 As shown.

[0065] In step two of this embodiment, based on the direction of movement of the tube to be plated 14, the controller controls the polarity of power supply I1-1 and power supply II2-2, and the roles of target I9-1 and target II9-2 in the process are as follows: Figure 2 and Figure 3 As shown.

[0066] In step two of this embodiment, the target used for cleaning is as follows: Figure 2 and Figure 3 The power supply indicated is a bipolar pulsed power supply with a frequency of 600Hz, a negative pulse voltage of 1300V, a pulse width of 20μs, and a positive pulse off. The target used for deposition is as follows: Figure 2 and Figure 3 The power supply indicated is a bipolar pulse power supply with a frequency of 300Hz, a negative pulse voltage of 550V, a pulse width of 100μs, and a positive pulse voltage of 50V with a pulse width of 50μs 10μs after the negative pulse ends. The two power supplies are phase-coupled through a controller to prevent the pulses from acting simultaneously.

[0067] In step two of this embodiment, the speed of the tube to be plated is 5 mm / s.

[0068] In step one of this embodiment, the tube 3 to be coated is a carbon steel tube with a length of 2m and an inner diameter of 50mm. After the synchronous cleaning and coating process is completed, the cross-sectional morphology of the Ti film deposited at different locations inside the tube is as follows: Figure 4 As shown, the thickness of the obtained film layer is uniform at all locations.

[0069] Example 2:

[0070] A method for using a device for simultaneous cleaning and coating of the inner wall of a slender pipe, comprising the following steps:

[0071] 1. Clean the tube 14 to be plated by ultrasonic cleaning with acetone and anhydrous ethanol for 30 minutes in sequence, then take it out, dry it and fix it in the vacuum chamber 6.

[0072] 2. Evacuate vacuum chamber 6 to 8×10⁻⁶. -3 Pa, introduce Ar and adjust the air pressure to 1Pa, turn on power supply I1-1, power supply II1-2 and reciprocating motor 13, set the movement direction and speed of the tube to be coated 14, as well as the polarity and discharge parameters of power supply I1-1 and power supply II1-2 through the controller, and perform synchronous cleaning and coating of the inner wall of the pipe for 5 hours.

[0073] 3. After the process is completed, turn off the power supply I1-1, power supply II1-2 and reciprocating motor 13. After the coating tube 14 cools down, the coating of the inner wall of the slender pipe is completed.

[0074] The device used in this embodiment Figure 1 As shown.

[0075] In step two of this embodiment, based on the direction of movement of the tube to be plated 14, the controller controls the polarity of power supply I1-1 and power supply II2-2, and the roles of target I9-1 and target II9-2 in the process are as follows: Figure 2 and Figure 3 As shown.

[0076] In step two of this embodiment, the target used for cleaning (such as...) Figure 2 and Figure 3 The power supply connected (as indicated in the image) is a bipolar pulse power supply with a frequency of 1000Hz, a negative pulse voltage of 1500V, a pulse width of 25μs, and a positive pulse off. The target used for deposition (such as...) Figure 2 and Figure 3 The power supply (as indicated in the diagram) is a bipolar pulse power supply with a frequency of 300Hz. The negative pulse voltage is 560V with a pulse width of 150μs. 10μs after the negative pulse ends, the positive pulse voltage is 50V with a pulse width of 50μs. The two power supplies are phase-coupled through a controller to prevent the pulses from acting simultaneously.

[0077] In step two of this embodiment, the speed of the tube to be plated is 5 mm / s.

[0078] In step one of this embodiment, the tube to be coated, 3, is a carbon steel tube with a length of 3m and an inner diameter of 40mm. After the synchronous cleaning and coating process is completed, the cross-sectional morphology of the Cr film deposited at different locations inside the tube is as follows: Figure 5 As shown, the obtained film layer has a uniform thickness at all locations and is dense.

Claims

1. A device for synchronous cleaning and coating of the inner wall of a slender pipe, characterized in that... It includes power supply I (1-1), water inlet pipe I (2-1), air inlet pipe I (3-1), water outlet pipe I (4-1), flange I (5-1), vacuum chamber (6), air inlet I (7-1), clamp I (8-1), target I (9-1), guide rail (10), slider (11), controller (12), reciprocating motor (13), tube to be plated (14), air extraction port (15), target II (9-2), clamp II (8-2), air inlet II (7-2), flange II (5-2), water outlet pipe II (4-2), air inlet pipe II (3-2), water inlet pipe II (2-2), and power supply II (1-2); The guide rail (10) is fixed inside the vacuum chamber (6), and the tube to be plated (14) is fixed on the slider (11). The slider (11) is driven by the reciprocating motor (13) to drive the tube to be plated (14) to reciprocate along the guide rail (10). The water inlet pipe I (2-1), air inlet pipe I (3-1), water outlet pipe I (4-1), clamp I (8-1), target I (9-1), tube to be plated (14), clamp II (8-2), water outlet pipe II (4-2), air inlet pipe II (3-2) and water inlet pipe II (2-2) are coaxially installed. The air inlet pipe I (3-1) has an air inlet hole I (7-1) and the air inlet pipe II (3-2) has an air inlet hole II (7-2). The power supply I (1-1) is electrically connected to the tube to be plated (14) and target I (9-1), the power supply II (1-2) is electrically connected to the tube to be plated (14) and target II (9-2), the tube to be plated (14) is at the same potential as the vacuum chamber (6), and the polarity of the power supply I (1-1) and the power supply II (1-2) and the direction of movement of the tube to be plated (14) are controlled by the controller (12); The clamp I (8-1) connects the air inlet pipe I (3-1), the water outlet pipe I (4-1) and the target I (9-1); the air inlet pipe I (3-1) and the water outlet pipe I (4-1) extend out of the vacuum chamber (6) from the top of the vacuum chamber (6) and are fixed to the outer wall of the vacuum chamber (6) by the flange I (5-1); Fixture II (8-2) connects air inlet pipe II (3-2), water outlet pipe II (4-2) and target II (9-2); air inlet pipe II (3-2) and water outlet pipe II (4-2) extend out of vacuum chamber (6) from the bottom end of vacuum chamber (6) and are fixed to the outer wall of vacuum chamber (6) by flange II (5-2); air inlet pipe II (3-2) and water outlet pipe II (4-2) can move relative to flange I (5-1) or flange II (5-2); A gap is left between target I (9-1) and target II (9-2), and the two can also be connected by insulating clamps; The lower part of the air inlet pipe I (3-1) has air inlet holes I (7-1) evenly distributed in a ring, and the upper part of the air inlet pipe II (3-2) has air inlet holes II (7-2) evenly distributed in a ring; the air extraction port (15) is located on the side wall of the vacuum chamber (6). The polarity of power supply I (1-1) and power supply II (1-2) is matched with the movement direction of the tube to be plated (14) by the controller (12): When the tube to be plated (14) moves to the bottom of the vacuum chamber (6), the positive terminal of power supply I (1-1) is connected to target I (9-1), and the negative terminal is connected to the tube to be plated (14) for cleaning. The negative terminal of power supply II (1-2) is connected to target II (9-2), and the positive terminal is connected to the tube to be plated (14) for deposition. When the tube to be plated (14) moves toward the top of the vacuum chamber (6), the negative terminal of power supply I (1-1) is connected to target I (9-1), and the positive terminal is connected to the tube to be plated (14) for deposition; the positive terminal of power supply II (1-2) is connected to target II (9-2), and the negative terminal is connected to the tube to be plated (14) for cleaning. When the controller (12) switches the polarity of power supply I (1-1) and power supply II (1-2) with the direction of movement of the tube to be plated (14), it can simultaneously adjust the speed of movement of the tube to be plated (14), the process parameters of power supply I (1-1) and power supply II (1-2); The power supply I (1-1) and power supply II (1-2) are DC power supplies or bipolar power supplies; the tube to be plated (14) is a magnetic or non-magnetic conductive material.

2. The method of using the synchronous cleaning and coating device for the inner wall of a slender pipe as described in claim 1, characterized in that, It is implemented in the following steps:

1. Clean the tube (14) to be plated with acetone and anhydrous ethanol for 5-60 minutes in sequence, take it out, dry it and fix it in the vacuum chamber (6); 2. Evacuate the vacuum chamber (6) to 8×10⁻⁶. -3 Pa, introduce working gas and / or reaction gas and adjust the gas pressure to 0.01-20Pa, turn on power supply I (1-1), power supply II (1-2) and reciprocating motor (13), set the movement direction and speed of the tube to be coated (14) and the polarity and discharge parameters of power supply I (1-1) and power supply II (1-2) through the controller, and perform synchronous cleaning and coating of the inner wall of the pipe.

3. After the process is completed, turn off the power supply I (1-1), power supply II (1-2) and reciprocating motor (13). After the tube (14) is cooled, the inner wall of the slender pipe is coated. The working gas mentioned in step two is He, Ne, Ar, Kr, Xe, or Rn; The reaction gas mentioned in step two is N2, H2, CH4, H2S, NH3, or O2.

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