A vacuum chamber carbon film cleaning method

Abstract

The present invention discloses a vacuum cavity carbon film cleaning method, which is suitable for removing carbon film on the inner wall of a pipeline in a plasma coating device. The plasma coating device comprises a target material, a pipeline, a magnetic field control system, an arc starting mechanism and a DC arc power supply. The pipeline is a hollow structure, and the magnetic field control system is arranged outside the pipeline. The method comprises the following steps: (1) electrically connecting the positive electrode of the DC arc power supply to the pipeline, and the negative electrode of the DC arc power supply to the target material; (2) using the DC arc power supply and the arc starting mechanism to start an arc on the surface of the target material to generate plasma in the pipeline; (3) using the magnetic field control system to control the plasma to bombard the inner wall of the pipeline to remove the carbon film on the inner wall of the pipeline. The method is efficient, environmentally friendly, convenient and low in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of arc coating equipment cleaning, and more specifically to a vacuum cavity carbon film cleaning method. Background Art

[0002] The tetrahedral amorphous carbon (ta-C) film in the diamond-like coating has an extremely high sp3 bond content, extremely high hardness and excellent anti-friction and anti-wear properties, extremely high thermal conductivity and excellent thermal shock resistance, extremely high resistivity and good doping performance. Generally, the ta-C coating is deposited by the curved tube magnetic filtration arc technology, but long-term use will form a very thick carbon film layer on the inner wall of the magnetic filtration curved tube or cavity, thereby accumulating a large amount of dust and adsorbing gas. The thick film accumulates on the inner wall of the curved tube or cavity, affecting the resistance of the equipment and the deposition electric field; at the same time, the adsorbed gas is released slowly during the vacuum process, and the equipment exhaust speed time becomes longer; in addition, the dust particles cannot be removed cleanly, and they will float during the deposition process and deposit on the surface of the product, affecting the quality. Therefore, the carbon film on the inner wall needs to be cleaned regularly to ensure the normal operation of the electric field in the curved tube and to ensure the quality of the coating.

[0003] Currently, the commonly used cleaning methods for the carbon film layer on the inner wall of the cavity are: (1) physical grinding, such as sandblasting the bent pipe, brushing the inside of the pipe, and tapping with a file. However, conventional physical grinding methods cannot effectively remove the film layer. The physical sandblasting process requires the removal of the pipe wall or lining, which is time-consuming and inefficient. (2) Chemical stripping requires the use of chemical reagents and has environmental risks. In addition, as the film thickness increases, the processing time becomes longer, the efficiency is low, and the cost is high.

[0004] In addition, Chinese patent CN213316660U discloses a thin film deposition reaction chamber cleaning device. When in use, the motor drives the main shaft to rotate, and the main shaft drives the first scraper and the second scraper to rotate, and drives the brush head to rotate, completing the detailed cleaning process of the inner wall of the chamber. However, since the carbon film coating is hard and difficult to remove, this process is not suitable for cleaning the carbon film on the inner wall of the bent pipe. Summary of the invention

[0005] In order to overcome the defects of the prior art, the purpose of the present invention is to provide a vacuum chamber carbon film cleaning method, which can efficiently and environmentally remove the carbon film on the inner wall of the pipeline, and is particularly suitable for bent pipes.

[0006] In order to achieve the above-mentioned object, the present invention discloses a vacuum cavity carbon film cleaning method, which is suitable for removing the carbon film on the inner wall of a pipeline in a plasma coating device. The plasma coating device comprises a target material, a pipeline, a magnetic field control system, an arc starting mechanism and a DC arc power supply. The pipeline is a hollow structure, and the magnetic field control system is arranged outside the pipeline, comprising the steps of:

[0007] (1) The positive electrode of the DC arc power supply is electrically connected to the pipeline, and the negative electrode of the DC arc power supply is electrically connected to the target material.

[0008] (2) using the DC arc power supply and the arc striking mechanism to strike an arc on the target surface to generate plasma in the pipe;

[0009] (3) The magnetic field control system is used to control the plasma to bombard the inner wall of the pipeline to remove the carbon film on the inner wall of the pipeline.

[0010] Compared with the prior art, the vacuum chamber carbon film cleaning method of the present invention has the positive electrode of the DC arc power supply electrically connected to the bent pipe, and the negative electrode of the DC arc power supply electrically connected to the target material, and a large amount of plasma is generated in the pipeline by the action of the arc striking mechanism and the DC arc power supply, and then the plasma is controlled by the magnetic field control system to bombard the inner wall of the pipeline, ablating the carbon film on the pipe wall, so as to remove the carbon film on the inner wall of the pipeline, expose the pipe wall, improve the conductivity and cleanliness of the pipe wall, and then improve the coating quality when the plasma coating device is deposited. The method is efficient, environmentally friendly, convenient, and low-cost.

[0011] Preferably, the magnetic field control system includes a magnetic coil arranged outside the pipeline, and the distribution of magnetic lines of force is changed by adjusting the current passed through the magnetic coil, so that the plasma bombards different positions of the inner wall of the pipeline for a certain period of time.

[0012] Preferably, the bombardment time is 30s-300s.

[0013] Preferably, the pipeline is a bent pipe structure, including a primary tube, a secondary tube and a tertiary tube connected in sequence, the primary tube and the tertiary tube are straight tubes, the secondary tube is an arc structure, the positive pole of the DC arc power supply is electrically connected to the primary tube, and an insulating structure is provided between the primary tube and the secondary tube and between the secondary tube and the tertiary tube.

[0014] Preferably, the magnetic coil includes an arc stabilizing coil, a focusing coil, a guiding coil and a diverging coil. The arc stabilizing coil and the focusing coil are arranged on the outside of the primary tube, the guiding coil is arranged on the outside of the secondary tube, and the diverging coil is arranged on the outside of the tertiary tube.

[0015] Preferably, the current of the arc stabilizing coil is 2-8A, the current of the focusing coil is 1-12A, the current of the guiding coil is 4-7A and the current of the diverging coil is 10-20A.

[0016] Preferably, the number of turns of the arc stabilizing coil is 150-250 turns, the number of turns of the focusing coil is 120-200 turns, the number of turns of the guiding coil is 3000-5000 turns, and the number of turns of the diverging coil is 1800-2500 turns.

[0017] Preferably, the method further comprises the following process before step (2): introducing a reaction gas into the pipeline, wherein the reaction gas is selected from at least one of Ar, N2, and H2.

[0018] Preferably, the control method of the magnetic coil includes:

[0019] (1) The arc stabilizing coil, focusing coil, guiding coil and diverging coil are energized, and the current of the arc stabilizing coil is controlled to be 2-8A, the current of the focusing coil is controlled to be 1-5A, the current of the guiding coil is controlled to be 4-7A, and the current of the diverging coil is controlled to be 10-20A, and the operation time is greater than 30s;

[0020] (2) The current of the focusing coil, the current of the guiding coil and the current of the diverging coil are all adjusted to 0A, and the operation time is 30s-300s;

[0021] (3) The current of the focusing coil is adjusted to 3-6A, and the operating time is 30s-300s;

[0022] (4) The current of the focusing coil is adjusted to 6-12A, and the operating time is 30s-300s;

[0023] (5) The current of the pilot coil is adjusted to 4-7A, and the running time is 60s-300s;

[0024] (6) The current of the guide coil is adjusted to 0A, the current of the divergent coil is adjusted to 10-20A, and the operating time is 120s-300s.

[0025] Preferably, the current of the DC arc power supply is set to be greater than or equal to 70A.

[0026] The beneficial effects of the present invention are:

[0027] (1) The vacuum chamber carbon film cleaning method of the present invention adopts plasma bombardment, the cleaning depth is greater, the carbon film falls off to the substrate, and the removal effect is significant;

[0028] (2) The vacuum chamber carbon film cleaning method of the present invention realizes independent and continuous cleaning of the ion beam from the primary tube to the tertiary tube through the combination of the arc stabilizing coil, the focusing coil, the guiding coil and the diverging coil, and is applicable to the bent tube;

[0029] (3) The vacuum chamber carbon film cleaning method of the present invention does not require disassembly of equipment and can be cleaned in situ, thus saving labor and costs;

[0030] (4) The vacuum chamber carbon film cleaning method of the present invention performs vacuum operation in the pipeline, avoids a large amount of dust, and is highly efficient and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of the plasma coating device of the present invention.

[0032] Figure 2 The effect diagram shows that after the inner wall of the pipeline is treated by Example 1 of the vacuum chamber carbon film cleaning method of the present invention, the carbon film has fallen from the inner wall of the pipeline into the pipeline.

[0033] Figure 3 The effect diagram shows that after the inner wall of the pipeline is treated by Example 2 of the vacuum chamber carbon film cleaning method of the present invention, the carbon film has fallen from the inner wall of the pipeline into the pipeline. DETAILED DESCRIPTION

[0034] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, they are described in detail below in conjunction with the implementation methods.

[0035] The present invention provides a vacuum chamber carbon film cleaning method, which is suitable for removing the carbon film on the inner wall of a pipe 20 in a plasma coating device 100. The method can be used to efficiently and environmentally remove the carbon film on the inner wall of the pipe 20 to expose the pipe wall, thereby improving the conductivity and cleaning effect of the pipe wall, thereby improving the coating quality during deposition in the plasma coating device 100.

[0036] Please refer to Figure 1 , showing the plasma coating device 100 of the present invention, including a target material 10, a pipeline 20, a magnetic field control system (not shown), an arc striking mechanism 40 and a DC arc power supply 50, the pipeline 20 is a hollow structure, the magnetic field control system is arranged outside the pipeline 20, the positive electrode of the DC arc power supply 50 is electrically connected to the pipeline 20, and the negative electrode of the DC arc power supply 50 is electrically connected to the target material 10. It can be understood that the target material 10 can be but not limited to a graphite target material, the pipeline 20 can be a straight pipe or a curved pipe, the target material 10 and the arc striking mechanism 40 are located at one end of the pipeline 20, and the magnetic field control system is arranged outside the pipeline 20, and the magnetic field control system can be arranged according to the structure of the pipeline 20.

[0037] In the cleaning method of the present invention, a DC arc power supply 50 and an arc striking mechanism 40 are used to strike an arc on the surface of the target material 10, plasma is generated in the pipe 20, and then a magnetic field control system is used to control the plasma to bombard the inner wall of the pipe 20 to remove the carbon film on the inner wall of the pipe 20. In this technical solution, the positive electrode of the DC arc power supply 50 is electrically connected to the pipe 20, and the negative electrode of the DC arc power supply 50 is electrically connected to the target material 10. When the arc striking needle of the arc striking mechanism 40 contacts the target material 10 to strike an arc, the arc spot moves under the continuous output of the DC arc power supply 50, and a large amount of plasma is generated in the pipe 20. Then, the magnetic field control system is used to control the plasma to bombard the inner wall of the pipe 20, and the carbon film on the pipe wall is ablated to remove the carbon film on the inner wall of the pipe 20, expose the pipe wall, improve the conductivity of the pipe wall and the cleaning effect, and then improve the coating quality of the plasma coating device 100 during deposition. The method is efficient and thorough, environmentally friendly, convenient, and low-cost.

[0038] Furthermore, the magnetic field control system includes a magnetic coil disposed outside the pipe 20. By adjusting the current passed through the magnetic coil, the distribution of magnetic lines of force is changed, so that the plasma bombards different positions of the inner wall of the pipe 20 for a certain period of time. Furthermore, the current of the DC arc power supply 50 is set to at least 70A, such as but not limited to 70A, 72A, 74A, 76A, 78A, 80A, and the bombardment speed and strength of the plasma are increased by a large current, the bombardment depth is increased, and the cleaning quality is improved.

[0039] In a preferred embodiment, please refer to Figure 1 The pipeline 20 is a curved pipe structure, including a primary tube 21, a secondary tube 23 and a tertiary tube 25 which are connected in sequence, the primary tube 21 and the tertiary tube 25 are straight tubes, the secondary tube 23 is located between the primary tube 21 and the tertiary tube 25 and is in an arc structure, that is, the primary tube 21, the secondary tube 23 and the tertiary tube 25 form a curved pipe, the positive electrode of the DC arc power supply 50 is electrically connected to the primary tube 21, and an insulating structure is provided between the primary tube 21 and the secondary tube 23 and between the secondary tube 23 and the tertiary tube 25. Further, magnetic coils are arranged on the outside of the primary tube 21, the secondary tube 23 and the tertiary tube 25 respectively. In a preferred embodiment, the magnetic coil includes an arc stabilizing coil 31, a focusing coil 33, a guiding coil 35 and a diverging coil 37. The arc stabilizing coil 31 and the focusing coil 33 are respectively arranged on the outside of the primary tube 21. The arc stabilizing coil 31 is arranged close to the target material 10, and the focusing coil 33 is arranged away from the target material 10. The arc stabilizing coil 31 is used to control the stability of ablation of the target material 10. The focusing coil 33 drives the electron beam to move toward the inner wall of the primary tube 21 according to current control. The guiding coil 35 is arranged on the outside of the secondary tube 23 to guide the electrons to spiral forward and attract the positive ions to move forward. The diverging coil 37 is arranged on the outside of the tertiary tube 25. The two ends of the magnetic field lines diverge and deflect outward, and the electrons spirally diverge along the direction of the magnetic lines, attracting the positive ions to spirally diverge forward.

[0040] In the above technical solution, the arc stabilizing coil 31, the focusing coil 33, the guiding coil 35 and the diverging coil 37 are started, and a certain current is set so that the magnetic lines of force form a stable and suitable magnetic field, and then the DC arc power supply 50 and the arc starting mechanism 40 start the arc on the surface of the target material 10, and generate plasma in the pipe 20; by adjusting the current passed through the magnetic coil, the distribution of the magnetic lines of force is changed, so that the plasma bombards different positions of the inner wall of the pipe 20 for a certain period of time. That is to say, under the action of the arc stabilizing coil 31, the focusing coil 33, the guiding coil 35 and the diverging coil 37, the plasma bombards and ablates the inner wall of the pipe 20 along a roughly predetermined trajectory. Among them, the magnetic coils can be turned on at the same time or separately, but in order to ensure the normal use of the target material 10 in the later production and avoid arc source melting, the arc stabilizing coil 31 is always kept on. The particle beam bombardment time is from a few seconds to a few minutes, but not too long. Generally, the carbon film can be self-sustaining for several seconds after the bombardment and ignition, and a large amount of carbon ash is ejected. Preferably, the bombardment time is 30s-300s. In a preferred embodiment, a suitable reaction gas is introduced into the pipeline 20 to stabilize the gas pressure within a certain range, which has an arc stabilization effect. The reaction gas can be but is not limited to Ar, N2, H2.

[0041] In a preferred embodiment, the current of the arc stabilizing coil 31 is 2-8A, the current of the focusing coil 33 is 1-12A, the current of the guiding coil 35 is 4-7A, and the current of the diverging coil 37 is 10-20A. Furthermore, the number of turns of the arc stabilizing coil 31, the focusing coil 33, the guiding coil 35, and the diverging coil 37 are 150-250 turns, 120-200 turns, 3000-5000 turns, and 1800-2500 turns, respectively;

[0042] In a preferred embodiment, the control method of the magnetic coil includes:

[0043] (1) The arc stabilizing coil 31, the focusing coil 33, the guiding coil 35 and the diverging coil 37 are energized, and the current of the arc stabilizing coil 31 is controlled to be 2-8A, the current of the focusing coil 33 is controlled to be 1-5A, the current of the guiding coil 35 is controlled to be 4-7A and the current of the diverging coil 37 is controlled to be 10-20A, and the operation time is greater than 30s, so as to make the ablation of the target material 10 in a stable state;

[0044] (2) The currents of the focusing coil 33, the guiding coil 35, and the diverging coil 37 are all adjusted to 0 A. The operation time is 30s-300s. At this time, the current of the arc stabilizing coil 31 is controlled to be 2-8A. During this process, the particle beam bombards the inner wall of the primary tube 21.

[0045] (3) The current of the focusing coil is adjusted to 3-6A, and the operation time is 30s-300s. At this time, the current of the arc stabilizing coil 31 is 2-8A, the current of the focusing coil 33 is 3-6A, and the current of the guiding coil 35 and the current of the diverging coil 37 are both 0A. In this process, the particle beam bombards the inner wall of the diode 23;

[0046] (4) The current of the focusing coil is adjusted to 6-12A, and the operation time is 30s-300s. At this time, the current of the arc stabilizing coil 31 is 2-8A, the current of the focusing coil 33 is 6-12A, and the current of the guiding coil 35 and the current of the diverging coil 37 are both 0A. During this process, the particle beam continues to bombard the inner wall of the diode 23;

[0047] (5) The current of the guide coil is adjusted to 4-7A, and the operation time is 60s-300s. At this time, the current of the arc stabilizing coil 31 is 2-8A, the current of the focusing coil 33 is 6-12A, the current of the guide coil 35 is 4-7A, and the current of the diverging coil 37 is 0A. During this process, the particle beam continues to bombard the inner wall of the diode 23;

[0048] (6) The current of the guide coil is adjusted to 0A, and the current of the divergent coil is adjusted to 10-20A. The operation time is 120s-300s. At this time, the current of the arc stabilizing coil 31 is 2-8A, the current of the focusing coil 33 is 6-12A, the current of the guide coil 35 is 0A, and the current of the divergent coil 37 is 10-20A. During this process, the particle beam continues to bombard the inner wall of the three-pole tube 25.

[0049] The vacuum chamber carbon film cleaning method of the present invention is further described below through several specific embodiments, but is not limited thereto.

[0050] Example 1

[0051] A vacuum chamber carbon film cleaning method comprises the following steps:

[0052] (1) evacuating and cooling the pipeline 20;

[0053] (2) 35 sccm of argon gas is introduced into the pipe 20 to stabilize the vacuum pressure at 0.4-0.5 Pa;

[0054] (3) The arc is started by contacting the arc needle of the arc starting mechanism 40 with the target material 10, and then the arc spot moves under the continuous output of the DC arc power supply 50. The current is set to 70A, and a large amount of plasma is generated in the primary tube 21.

[0055] (4) By adjusting the current passed through the magnetic coil, the distribution of magnetic lines of force is changed, so that the plasma bombards different positions of the inner wall of the pipe 20 along a roughly predetermined trajectory for a certain period of time. The specific parameters are shown in Table 1. The control method of the magnetic coil includes:

[0056] (4.1) The arc stabilizing coil 31, the focusing coil 33, the guiding coil 35 and the diverging coil 37 are energized, and the current of the arc stabilizing coil 31 is controlled to be 3A, the current of the focusing coil 33 is controlled to be 1A, the current of the guiding coil 35 is controlled to be 4A, and the current of the diverging coil 37 is controlled to be 12A. The operation time is 180s, so that the ablation of the target material 10 is in a stable state;

[0057] (4.2) The currents of the focusing coil 33, the guiding coil 35 and the diverging coil 37 are all adjusted to 0A, and the operation time is 60s. At this time, the current of the arc stabilizing coil 31 is controlled to be 3A, and the particle beam bombards the inner wall of the primary tube 21 along the trajectory ①;

[0058] (4.3) The current of the focusing coil 33 is adjusted to 4A, and the operation time is 60s. At this time, the current of the arc stabilizing coil 31 is 3A, and the current of the guiding coil 35 and the current of the diverging coil 37 are both 0A. The particle beam bombards the inner wall of the diode 23 along the trajectory ②;

[0059] (4.4) The current of the focusing coil 33 is adjusted to 8A, and the operation time is 60s. At this time, the current of the arc stabilizing coil 31 is 3A, and the current of the guiding coil 35 and the current of the diverging coil 37 are both 0A. The particle beam bombards the inner wall of the diode 23 along the trajectory ③.

[0060] (4.5) The current of the guide coil 35 is adjusted to 6A, and the operation time is 60s. At this time, the current of the arc stabilizing coil 31 is 3A, the current of the focusing coil 33 is 8A, and the current of the diverging coil 37 is 0A. The particle beam bombards the inner wall of the diode 23 along the trajectory ④.

[0061] (4.6) The current of the guide coil 35 is adjusted to 0A, and the current of the divergent coil 37 is adjusted to 12A. The operation time is 120s. At this time, the current of the arc stabilizing coil 31 is 3A, and the current of the focusing coil 33 is 8A. The particle beam bombards the inner wall of the three-pole tube 25 roughly along the trajectory ⑤.

[0062] (5) After the first-stage tube 21, the second-stage tube 23 and the third-stage tube 25 are cleaned, the air is released by vacuum, the chamber door is opened, and the floating dust, film blocks and particles dropped by the bombardment are cleaned up by a vacuum cleaner.

[0063] See also Figure 2 , showing the effect of the carbon film falling from the inner wall of the pipe 20 into the pipe 20 after the inner wall of the pipe 20 is treated by the vacuum chamber carbon film cleaning method of this embodiment, Figure 2 It can be seen that the pipeline 20 contains a large amount of floating dust, film blocks and particles that are bombarded and dropped.

[0064] The resistance at multiple locations in the pipeline 20 was measured before and after cleaning, and the resistance changed from 4.0-7.0 MΩ (uncleaned) to 5.0-10.0 Ω (after cleaning), indicating that the conductivity of the pipe wall was greatly improved. In other words, the vacuum cavity carbon film cleaning method of the present invention is effective in removing the carbon film on the inner wall of the pipeline 20.

[0065] Table 1 Setting parameters of magnetic coil in Example 1

[0066]

[0067] Example 2

[0068] A vacuum chamber carbon film cleaning method comprises the following steps:

[0069] (1) evacuating and cooling the pipeline 20;

[0070] (2) 60 sccm of argon gas is introduced into the pipe 20 to stabilize the vacuum pressure at 0.22-0.26 Pa;

[0071] (3) The arc is started by contacting the arc needle of the arc starting mechanism 40 with the target material 10, and then the arc spot moves under the continuous output of the DC arc power supply 50. The current is set to 72A, and a large amount of plasma is generated in the primary tube 21.

[0072] (4) By adjusting the current passed through the magnetic coil, the distribution of magnetic lines of force is changed, so that the plasma bombards different positions of the inner wall of the pipe 20 along a roughly predetermined trajectory for a certain period of time. The specific parameters are shown in Table 2. The control method of the magnetic coil includes:

[0073] (4.1) The arc stabilizing coil 31, the focusing coil 33, the guiding coil 35 and the diverging coil 37 are energized, and the current of the arc stabilizing coil 31 is controlled to be 4A, the current of the focusing coil 33 is controlled to be 2A, the current of the guiding coil 35 is controlled to be 4A, and the current of the diverging coil 37 is controlled to be 10A. The operation time is 60s, so that the ablation of the target material 10 is in a stable state;

[0074] (4.2) The current of the focusing coil 33, the current of the guiding coil 35 and the current of the diverging coil 37 are all adjusted to 0A, and the operation time is 60s. At this time, the current of the arc stabilizing coil 31 is 4A, and the particle beam bombards the inner wall of the primary tube 21 along the trajectory ①;

[0075] (4.3) The current of the focusing coil 33 is adjusted to 3A, and its current is increased from 3A to 6A within 90s. During this process, the current of the arc stabilizing coil 31 is 4A, and the current of the guiding coil 35 and the current of the diverging coil 37 are both 0A. The particle beam bombards the inner wall of the diode 23 along the trajectory ②.

[0076] (4.4) The current of the focusing coil 33 is adjusted to 7A, and the current is increased from 7A to 10A within 60s. During this process, the current of the arc stabilizing coil 31 is 4A, the current of the guiding coil 35 and the current of the diverging coil 37 are both 0A, and the particle beam bombards the inner wall of the diode 23 along trajectory ③;

[0077] (4.5) The current of the guide coil 35 is adjusted to 4A, and its current is increased from 4A to 6A within 90s. During this process, the current of the arc stabilizing coil 31 is 4A, the current of the focusing coil 33 is 10A, and the current of the diverging coil 37 is 0A. The particle beam bombards the inner wall of the diode 23 along the trajectory ④.

[0078] (4.6) The current of the guide coil 35 is adjusted to 0A, and the current of the divergent coil 37 is adjusted to 10A, and the current of the divergent coil 37 is increased from 10A to 20A within 120s. At this time, the current of the arc stabilizing coil 31 is 4A, and the current of the focusing coil 33 is 10A. The particle beam bombards the inner wall of the three-pole tube 25 roughly along the trajectory ⑤.

[0079] (5) After the first-stage tube 21, the second-stage tube 23 and the third-stage tube 25 are cleaned, the air is released by vacuum, the chamber door is opened, and the floating dust, film blocks and particles are cleaned by a vacuum cleaner.

[0080] See also Figure 3 , showing the effect of the carbon film falling from the inner wall of the pipe 20 into the pipe 20 after the inner wall of the pipe 20 is treated by the vacuum chamber carbon film cleaning method of this embodiment, Figure 3 It can be seen that the pipeline 20 contains a large amount of floating dust, film blocks and particles that are bombarded and dropped.

[0081] The resistance at multiple locations in the pipeline 20 was measured before and after cleaning, and the resistance changed from 0.5-3.0 MΩ (uncleaned) to 0.5-2.0 Ω (after cleaning), indicating that the conductivity of the pipe wall was greatly improved. In other words, the vacuum cavity carbon film cleaning method of the present invention is effective in removing the carbon film on the inner wall of the pipeline 20.

[0082] Table 2 Setting parameters of magnetic coil in Example 2

[0083]

[0084] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A vacuum chamber carbon film cleaning method, suitable for removing carbon film on the inner wall of a pipe in a plasma coating device, the plasma coating device comprising a target material, a pipe, a magnetic field control system, an arc starting mechanism and a DC arc power supply, the pipe is a hollow structure, the magnetic field control system is arranged outside the pipe, and is characterized in that: Includes steps: (1) electrically connecting the positive electrode of the DC arc power supply to the pipeline, and electrically connecting the negative electrode of the DC arc power supply to the target; (2) using the DC arc power supply and the arc striking mechanism to strike an arc on the target surface to generate plasma in the pipe; (3) using the magnetic field control system to control the plasma to bombard the inner wall of the pipeline to remove the carbon film on the inner wall of the pipeline; The magnetic field control system includes a magnetic coil arranged on the outside of the pipeline. The pipeline is a curved pipe structure, including a primary tube, a secondary tube and a tertiary tube connected in sequence. The magnetic coil includes an arc stabilizing coil, a focusing coil, a guide coil and a diverging coil. The arc stabilizing coil and the focusing coil are arranged on the outside of the primary tube, the guide coil is arranged on the outside of the secondary tube, and the diverging coil is arranged on the outside of the tertiary tube.

2. The vacuum chamber carbon film cleaning method according to claim 1, characterized in that: By adjusting the current passed through the magnetic coil, the distribution of magnetic lines of force is changed, so that the plasma bombards different positions of the inner wall of the pipeline for a certain period of time.

3. The vacuum chamber carbon film cleaning method according to claim 2, characterized in that: The bombardment time is 30s-300s.

4. The vacuum chamber carbon film cleaning method according to claim 2, characterized in that: The primary tube and the tertiary tube are straight tubes, the secondary tube is an arc-shaped structure, the positive pole of the DC arc power supply is electrically connected to the primary tube, and an insulation structure is provided between the primary tube and the secondary tube and between the secondary tube and the tertiary tube.

5. The vacuum chamber carbon film cleaning method according to claim 1, characterized in that: The current of the arc stabilizing coil is 2-8A, the current of the focusing coil is 1-12A, the current of the guiding coil is 4-7A and the current of the diverging coil is 10-20A.

6. The vacuum chamber carbon film cleaning method according to claim 5, characterized in that: The number of turns of the arc stabilizing coil is 150-250 turns, the number of turns of the focusing coil is 120-200 turns, the number of turns of the guiding coil is 3000-5000 turns, and the number of turns of the diverging coil is 1800-2500 turns.

7. The vacuum chamber carbon film cleaning method according to claim 1, characterized in that: The method further includes performing the following process before step (2): introducing a reaction gas into the pipeline, wherein the reaction gas is selected from at least one of Ar, N2, and H2.

8. The vacuum chamber carbon film cleaning method according to claim 5, characterized in that: The control method of the magnetic coil comprises: (1) energizing the arc stabilizing coil, the focusing coil, the guiding coil and the diverging coil, controlling the current of the arc stabilizing coil to be 2-8A, the current of the focusing coil to be 1-5A, the current of the guiding coil to be 4-7A, the current of the diverging coil to be 10-20A, and the operation time to be greater than 30s; (2) The current of the focusing coil, the current of the guiding coil and the current of the diverging coil are all adjusted to 0A, and the operation time is 30s-300s; (3) The current of the focusing coil is adjusted to 3-6A, and the operating time is 30s-300s; (4) The current of the focusing coil is adjusted to 6-12A, and the operating time is 30s-300s; (5) The current of the guide coil is adjusted to 4-7A, and the operating time is 60s-300s; (6) The current of the guide coil is adjusted to 0A, the current of the divergent coil is adjusted to 10-20A, and the operating time is 120s-300s.

9. The vacuum chamber carbon film cleaning method according to claim 1, characterized in that: The current of the DC arc power supply is set to be greater than or equal to 70A.

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