A coating apparatus for exciting a uniform plasma within an elongate tube

Abstract

The application relates to the field of coating technology, in particular to a coating equipment for exciting uniform plasma in an elongated tube, which comprises a rack, a quartz boat, a pushing device and a gas conveying device; a connecting cylinder is fixed on the rack; a conveying pipe is arranged at the lower end of the connecting cylinder; the gas conveying device comprises a dilution assembly and a mixing assembly; the dilution assembly is used for separately diluting precursor gas and reaction gas by carrier gas; and the mixing assembly is used for uniformly mixing the separately diluted precursor gas and reaction gas and then inputting the mixed gas into the conveying pipe. The carrier gas is used for preliminarily diluting the precursor gas and the reaction gas by the dilution assembly, so that only dilution effect is generated on the three kinds of gas at the dilution assembly, and the generation of byproduct particles caused by long-time contact between the precursor gas and the reaction gas is avoided; then the separately diluted precursor gas and reaction gas are rapidly and uniformly mixed by the mixing assembly, so that the uniformity of subsequent plasma distribution is ensured.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and more specifically to a coating apparatus for exciting uniform plasma inside a slender tube. Background Technology

[0002] Plasma-enhanced chemical vapor deposition (PECVD) is a process that efficiently deposits high-quality functional thin films on low-temperature workpieces by introducing plasma to activate gaseous precursors. The system consists of control, vacuum, radio frequency (RF), pulse, heating, and reaction modules, specifically including a control frame, vacuum pump assembly, RF plasma source, pulse module, heating module, and a sealed reaction furnace. In operation, a thin-tube workpiece is placed into the reaction furnace via a quartz boat. The thermal field is activated, and a mixed gas, including precursor gas, reactant gas, and carrier gas, is simultaneously introduced into the furnace. The RF power supply is then turned on to excite the plasma. Under a precisely controlled reaction atmosphere, the thin film is deposited on the inner wall of the workpiece.

[0003] In existing technologies, the precursor gas, reactant gas, and carrier gas are often directly introduced into the reactor for mixing. However, most precursor gases and reactant gases are highly reactive (e.g., silane SiH4 with ammonia NH3 and oxygen O2). If mixed in advance, temperature fluctuations or trace impurities may trigger a gas-phase reaction in the quartz capillary, generating powdery byproducts (e.g., SiN). X These particles, once inside the cavity, can contaminate the workpiece, leading to defects in the deposited film. Summary of the Invention

[0004] This invention provides a coating apparatus for exciting uniform plasma within a slender tube to solve the aforementioned problems.

[0005] The present invention provides a coating device for exciting uniform plasma in a slender tube, which adopts the following technical solution: A coating device for exciting uniform plasma in a slender tube includes a frame, a quartz boat, a pushing device, and a gas conveying device.

[0006] The frame is arranged vertically, with a reactor at the lower end; the reactor contains a radio frequency plasma generator; a heating module is provided on the outer wall of the reactor; a connecting cylinder is fixed on the frame; the axis of the connecting cylinder is arranged vertically above the reactor; a conveying pipe is provided at the lower end of the connecting cylinder; the axis of the conveying pipe is parallel to the axis of the connecting cylinder; the lower end of the conveying pipe extends into the reactor; a vacuum assembly is provided at the lower end of the conveying pipe; the upper end of the conveying pipe is fixedly connected to the connecting cylinder.

[0007] The quartz boat is placed inside the conveying pipe; the quartz boat has a receiving hole with a vertical axis; the receiving hole is a through hole; a slender metal tubular workpiece is inserted into the receiving hole; the receiving hole serves to shield the outer wall of the workpiece; a replacement device is provided inside the connecting cylinder; the replacement device is used to replace the quartz boat while maintaining a vacuum inside the conveying pipe.

[0008] The gas delivery device includes a gas delivery cylinder, a dilution component, and a mixing component. The gas delivery cylinder and the delivery pipe are coaxially and fixedly connected to the upper end of a connecting cylinder. The gas delivery cylinder and the delivery pipe are connected through the connecting cylinder. Both the dilution component and the mixing component are located inside the gas delivery cylinder, with the mixing component positioned below the dilution component. The dilution component is used to dilute the precursor gas and the reactant gas separately with the carrier gas. The mixing component is used to uniformly mix the separately diluted precursor gas and reactant gas before introducing them into the delivery pipe. This allows the carrier gas to perform primary dilution of the precursor gas and reactant gas separately through the dilution component, ensuring that the three gases only have a dilution effect at the dilution component, thus avoiding prolonged contact between the precursor gas and the reactant gas and the generation of by-product particles. Then, the mixing component rapidly and uniformly mixes the separately diluted precursor gas and reactant gas to ensure the uniformity of the subsequent plasma distribution.

[0009] The pushing device is used to move the quartz boat inside the delivery pipe into the reactor.

[0010] Furthermore, the dilution assembly includes a main partition, a secondary partition, a first plate, and a second plate.

[0011] Both the main and auxiliary partitions are located in the upper section of the gas delivery cylinder; the main partition is fixed radially to the inner wall of the gas delivery cylinder; the main partition divides the upper section of the gas delivery cylinder into two non-communicating input chambers; the auxiliary partition is fixed radially to the inner wall of the gas delivery cylinder; the auxiliary partition and the main partition are fixedly connected in a cross shape; the auxiliary partition divides each input chamber into a carrier gas chamber and a matching chamber; the carrier gas chambers of both input chambers are vented with carrier gas; the matching chamber of one input chamber is vented with precursor gas, and the matching chamber of the other input chamber is vented with reactant gas.

[0012] The first plate is located at the lower end of the main partition; the edge of the first plate near the inner wall of the gas cylinder is fixedly connected to the inner wall of the gas cylinder; the upper end of the first plate is fixedly connected to the main partition; a distribution plate is provided below the first plate; the distribution plate is coaxially fixed inside the gas cylinder; a vertical strip is fixed on the upper surface of the distribution plate; the lower end of the first plate is fixedly connected to the vertical strip.

[0013] The first plate and the distribution plate divide the middle section of the gas delivery cylinder into two non-conductive dilution chambers; each dilution chamber corresponds to an input chamber.

[0014] The second plate is located at the lower end of the auxiliary partition plate; dilution gaps are formed between the two edges of the second plate near the inner wall of the gas delivery cylinder and the inner wall of the gas delivery cylinder; the size of the dilution gaps gradually increases from top to bottom; the upper end of the second plate is fixedly connected to the auxiliary partition plate; the first plate and the second plate are fixedly connected; the first plate and the second plate are cross-shaped in cross section on a horizontal plane perpendicular to the axis of the delivery pipe; the second plate divides each dilution chamber into a first chamber and a second chamber; the first chamber of the dilution chamber is connected to the carrier gas chamber of the corresponding input chamber, and the second chamber of the dilution chamber is connected to the mating chamber of the corresponding input chamber; the first chamber and the second chamber of the same dilution chamber are connected through the dilution gap; both the first plate and the second plate are spiral plates spiraling around the axis of the gas delivery cylinder. They are used to guide the gas spiral downwards, causing the gas to move towards the dilution gap due to centrifugal force. Carrier gas is introduced into the carrier gas chamber of both input chambers by an air pump; precursor gas is introduced into the mating chamber of one input chamber, and reactant gas is introduced into the mating chamber of the other input chamber; one dilution chamber contains carrier gas and precursor gas; the other dilution chamber contains carrier gas and reactant gas. Guided by the first and second plates, the carrier gas and precursor gas are diluted and mixed at the dilution gaps of the corresponding dilution chambers, and the carrier gas and reactant gas are diluted and mixed at the dilution gaps of the corresponding dilution chambers.

[0015] Furthermore, the dilution assembly also includes an auxiliary structure; the auxiliary structure is used to prevent the dilution and mixing of the carrier gas and the other two gases from changing from smooth to violent as the dilution gap increases, so as to prevent the carrier gas and the other two gases from reacting and generating impurity particles.

[0016] Furthermore, the auxiliary structure includes an auxiliary cylinder; the auxiliary cylinder is coaxially disposed inside the gas delivery cylinder and located within the dilution gap; the inner diameter of the auxiliary cylinder is smaller than that of the gas delivery cylinder; the upper end of the auxiliary cylinder is located below the upper end of the gas delivery cylinder; the upper end of the auxiliary cylinder is fixedly connected to the second plate; secondary gaps are formed between the inner wall of the auxiliary cylinder and the two edges of the second plate near the inner wall of the gas delivery cylinder. The gas entering the auxiliary cylinder is diluted and mixed at the secondary gaps; due to the presence of the auxiliary cylinder, the diluted and mixed gas is prevented from affecting the dilution of the undiluted gas, and the dilution gap at the auxiliary cylinder is divided into smaller secondary gaps, thereby preventing the carrier gas and the other two gases from diluting and mixing from a stable state to a violent one.

[0017] Furthermore, multiple auxiliary cylinders are provided; the inner diameters of the multiple auxiliary cylinders decrease one after another, and the upper end of the auxiliary cylinder with the smaller inner diameter is located below the upper end of the adjacent auxiliary cylinder with the larger inner diameter.

[0018] Furthermore, the mixing component is located in the lower section of the gas delivery cylinder; the mixing component includes a first sub-cylinder, a second sub-cylinder, an outer hole, and an inner hole.

[0019] Multiple first and second sub-cylinders are arranged alternately on top of each other; the first and second sub-cylinders are coaxially arranged inside the gas delivery cylinder; the diameter of the first sub-cylinder is larger than that of the second sub-cylinder; adjacent first and second sub-cylinders are fixedly connected; multiple first sub-cylinders and multiple second sub-cylinders constitute a mixing cylinder, and the upper end of the mixing cylinder is fixedly connected to the distribution plate; the space between the mixing cylinder and the gas delivery cylinder is set as an outer cavity; the space inside the mixing cylinder is set as an inner cavity.

[0020] The first mixing cylinder has multiple first mixing ports distributed circumferentially on its side wall; a first baffle is rotatably installed on the first mixing port; the first baffle is rotatably installed inside the first mixing port via a first rotating shaft; the axis of the first rotating shaft is parallel to the axis of the first mixing cylinder; a torsion spring connects the first baffle and the first mixing cylinder.

[0021] The second mixing port is circumferentially distributed on the side wall of the second mixing port; a second baffle is rotatably installed on the second mixing port; the second baffle is rotatably installed inside the second mixing port via a second rotating shaft; the axis of the second rotating shaft is parallel to the axis of the second mixing port; a torsion spring connects the second baffle and the second mixing port.

[0022] The outer hole is a through hole opened on the distribution plate; the outer hole is located on one side of the vertical bar; the outer hole connects the outer cavity and a dilution cavity.

[0023] The inner hole is a through hole formed on the distribution plate; the inner hole is located on the other side of the vertical bar; the inner hole connects the inner cavity and another dilution chamber. The precursor gas, diluted by the carrier gas, enters the outer cavity from the dilution chamber through the outer hole. At the same time, the reactant gas, diluted by the carrier gas, enters the inner cavity from the dilution chamber through the inner hole. Since the diameter of the first dividing cylinder is larger than that of the second dividing cylinder, when the gas passes through the first dividing cylinder, the gas pressure inside the first dividing cylinder is greater than the gas pressure outside the first dividing cylinder, thereby pushing the first baffle from the inside out into the outer cavity; when the gas passes through the second dividing cylinder, the gas pressure inside the second dividing cylinder is less than the gas pressure outside the second dividing cylinder, thereby pushing the second baffle from the outside in into the inner cavity. This allows the two diluted gases to flow alternately inside and outside the mixing cylinder multiple times, so that the separately diluted precursor gas and reactant gas are quickly and uniformly mixed to ensure the uniformity of the subsequent plasma distribution.

[0024] Furthermore, the first and second dampers are inclined radially relative to the mixing cylinder when they open, causing the gas to form a vortex flow inside and outside the mixing cylinder, promoting mixing. The first and second dampers are inclined in the same direction when they open, causing the vortex flow to move in opposite directions inside and outside the mixing cylinder, further promoting uniform gas mixing.

[0025] Furthermore, there are two gas delivery devices; the two gas delivery devices are arranged one above the other, with the upper gas delivery device located inside the gas delivery cylinder; the lower gas delivery device is located inside the lower end of the delivery pipe; the mixed gas enters the interior of the workpiece from both the upper and lower ends, improving the coating efficiency.

[0026] Furthermore, the pushing device includes a push rod, a limiting rod, a top plate, and an air supply assembly; the push rod is arranged vertically, with its lower end extending into the air supply cylinder and sliding vertically and rotating with the air supply cylinder; a matching rod is fixed to the lower end of the push rod; the matching rod and the push rod are perpendicular and T-shaped; the limiting rod and the axis of the push rod are perpendicularly fixed to the upper end of the quartz boat; two limiting rods are arranged in parallel; the distance between the two limiting rods is greater than the diameter of the matching rod and less than the length of the matching rod; the top plate is located below the limiting rods; the top plate is fixed on the quartz boat; when pushing the quartz boat, the push rod is pushed, causing the matching rod to pass vertically between the two limiting rods, and then the push rod is rotated, causing the matching rod to lock between the top plate and the limiting rod, thereby realizing the push rod driving the quartz boat to move.

[0027] The gas delivery assembly is used to deliver the three gases mixed by the mixing assembly to the workpiece inside the receiving hole to improve the coating efficiency on the inner wall of the workpiece. The gas delivery assembly includes a gas delivery hole, a connecting hole, and a bellows. The gas delivery hole is opened on the end face of the lower end of the push rod. The axis of the gas delivery hole is vertically set. The connecting hole is opened on the side wall of the push rod. The connecting hole and the gas delivery hole are connected. The bellows is coaxially sleeved on the push rod and is located at the lower end of the mixing cylinder. The upper end of the bellows is fixedly connected to the inner wall of the gas delivery cylinder, and the lower end is fixed with a sealing plate. The sealing plate is located below the connecting hole. The sealing plate and the push rod are rotatably engaged. The three gases mixed by the mixing assembly enter the bellows, enter the gas delivery hole through the connecting hole, and are then delivered to the workpiece inside the receiving hole to improve the coating efficiency on the inner wall of the workpiece.

[0028] Furthermore, the replacement device includes an air extraction port, a replacement hole, and a turntable. The air extraction port is located on the side wall of the connecting cylinder and is used to connect a vacuum pump. The replacement hole is opened on the upper end face of the connecting cylinder and is located on one side of the delivery pipe; the turntable is coaxially and rotatably mounted inside the connecting cylinder; a motor is fixed on the frame; the output shaft of the motor is fixedly connected to the turntable; the turntable has two load-bearing through holes symmetrically arranged about its own axis, one above the other; initially, one load-bearing through hole is coaxial with the delivery pipe, and the other load-bearing through hole is coaxial with and connected to the replacement hole; an air extraction port is provided between the side wall of the load-bearing through hole and the side wall of the turntable.

[0029] Two adjusting grooves are provided on both sides of the line connecting the two bearing through holes; each adjusting groove corresponds to one bearing through hole; the adjusting groove and the corresponding bearing through hole are connected by a ventilation channel provided in the turntable; a solenoid valve is provided on the ventilation channel. When the quartz boat needs to be replaced, the pushing device moves the old quartz boat into the connecting cylinder and into the bearing through hole. Then, the new quartz boat is placed into the bearing through hole coaxial with the replacement hole, and then the turntable is driven to rotate. The turntable carries the new quartz boat to the conveying pipe. When the evacuation port of the bearing through hole carrying the new quartz boat and the evacuation port on the connecting cylinder are aligned and connected, the vacuum pump and solenoid valve are activated to extract the air from the bearing through hole carrying the new quartz boat and the corresponding adjusting groove to form a vacuum. Then, the solenoid valve is closed, and the turntable continues to rotate until the bearing through hole carrying the old quartz boat and the replacement hole are coaxial. The old quartz boat is then removed, thus ensuring that the quartz boat is replaced without breaking the air. After the reaction, the turntable is driven to rotate, so that the vacuum adjustment tank is aligned with the conveying pipe, and the by-product particles generated in the conveying pipe are extracted, thus avoiding contamination of the workpiece by the by-product particles in the gas.

[0030] The beneficial effects of this invention are: the carrier gas is used to perform primary dilution of the precursor gas and the reactant gas through the dilution component, so that the three gases only have a dilution effect at the dilution component, avoiding the generation of by-product particles due to prolonged contact between the precursor gas and the reactant gas; and the mixed component is used to quickly and uniformly mix the separately diluted precursor gas and reactant gas to ensure the uniformity of subsequent plasma distribution.

[0031] Furthermore, the gas entering the auxiliary cylinder is diluted and mixed at the secondary gap; due to the presence of the auxiliary cylinder, the diluted and mixed gas is prevented from affecting the dilution of the undiluted gas, and the dilution gap at the auxiliary cylinder is divided into smaller secondary gaps, thereby preventing the carrier gas and the other two gases from diluting and mixing from being stable to being violent.

[0032] Furthermore, when the quartz boat needs to be replaced, the pushing device moves the old quartz boat into the connecting cylinder and places it within the bearing through hole. Then, the new quartz boat is placed into the bearing through hole, which is coaxial with the replacement hole. The turntable is then driven to rotate, carrying the new quartz boat towards the delivery pipe. When the evacuation port of the bearing through hole carrying the new quartz boat aligns with the evacuation port on the connecting cylinder, the vacuum pump and solenoid valve are activated to extract air from the bearing through hole carrying the new quartz boat and the corresponding adjusting groove, creating a vacuum. The solenoid valve is then closed, and the turntable continues to rotate until the bearing through hole carrying the old quartz boat is coaxial with the replacement hole. At this point, the old quartz boat is removed, thus ensuring that the quartz boat is replaced without breaking the vacuum.

[0033] Furthermore, after the reaction, the turntable is driven to rotate, so that the vacuum adjustment tank is aligned with the conveying pipe, and the by-product particles generated in the conveying pipe are extracted, thus avoiding contamination of the workpiece by the by-product particles in the gas. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of an embodiment of a coating apparatus for exciting uniform plasma in a slender tube according to the present invention.

[0036] Figure 2 This is a front view of an embodiment of a coating apparatus for exciting uniform plasma within a slender tube according to the present invention.

[0037] Figure 3 This is a schematic diagram of the pushing device and gas conveying device of an embodiment of a coating device for exciting uniform plasma in a slender tube according to the present invention.

[0038] Figure 4 This is a schematic diagram of the main partition, secondary partition, and gas delivery cylinder of an embodiment of a coating device for exciting uniform plasma in a slender tube according to the present invention.

[0039] Figure 5 This is a schematic diagram of the gas delivery cylinder, first plate, second plate, first sub-cylinder, and second sub-cylinder of an embodiment of a coating device for exciting uniform plasma in a slender tube according to the present invention.

[0040] Figure 6 This is a schematic diagram of the first and second divider tubes of an embodiment of a coating apparatus for exciting uniform plasma in a slender tube according to the present invention.

[0041] Figure 7 This is a schematic diagram of a replacement device according to an embodiment of a coating apparatus for exciting uniform plasma in a slender tube according to the present invention.

[0042] Figure 8 This is a side view of the gas delivery device and the replacement device of an embodiment of a coating apparatus for exciting uniform plasma in a slender tube according to the present invention.

[0043] Figure 9 for Figure 8 A cross-sectional view along the AA direction;

[0044] Figure 10 for Figure 9 A cross-sectional view along the BB direction;

[0045] Figure 11 for Figure 9A cross-sectional view along the CC direction;

[0046] Figure 12 for Figure 9 A cross-sectional view along the DD direction;

[0047] Figure 13 for Figure 9 A cross-sectional view along the EE direction;

[0048] Figure 14 for Figure 13 Enlarged view at point F;

[0049] Figure 15 This is a diagram showing the state when the first and second gates are open, according to an embodiment of the coating apparatus for exciting uniform plasma in a slender tube of the present invention.

[0050] Figure 16 This is a schematic diagram of a turntable according to an embodiment of a coating apparatus for exciting uniform plasma in a slender tube according to the present invention.

[0051] Figure 17 This is a schematic diagram of a push rod and a quartz boat, representing an embodiment of a coating apparatus for exciting uniform plasma within a slender tube according to the present invention.

[0052] In the diagram: 100, frame; 110, reactor; 130, connecting cylinder; 140, conveying pipe; 200, quartz boat; 310, push rod; 320, limit rod; 330, top plate; 340, corrugated pipe; 341, gas inlet; 342, connecting hole; 400, gas delivery cylinder; 410, main partition plate; 420, secondary partition plate; 430, first plate; 440, second plate; 450, distribution plate; 451. Vertical bar; 460. Auxiliary cylinder; 470. First sub-cylinder; 471. First stop gate; 480. Second sub-cylinder; 481. Second stop gate; 491. Outer hole; 492. Inner hole; 510. Air extraction port; 520. Replacement hole; 530. Turntable; 540. Bearing through hole; 541. Air extraction hole; 542. Adjustment groove; 543. Ventilation channel; 544. Solenoid valve; 600. Workpiece. Detailed Implementation

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] An embodiment of the coating apparatus of the present invention for exciting uniform plasma within a slender tube, such as... Figures 1 to 17 As shown, it includes a frame 100, a quartz boat 200, a pushing device, and a gas conveying device.

[0055] The frame 100 is arranged vertically, with a reactor 110 at the lower end; the reactor 110 has a built-in radio frequency plasma generator; a heating module is provided on the outer wall of the reactor 110; a connecting cylinder 130 is fixed on the frame 100; the axis of the connecting cylinder 130 is arranged vertically above the reactor 110; a conveying pipe 140 is provided at the lower end of the connecting cylinder 130; the axis of the conveying pipe 140 is parallel to the axis of the connecting cylinder 130; the lower end of the conveying pipe 140 extends into the reactor 110; a vacuum assembly is provided at the lower end of the conveying pipe 140; the upper end of the conveying pipe 140 is fixedly connected to the connecting cylinder 130.

[0056] Quartz boat 200 is located inside conveying pipe 140; quartz boat 200 has a receiving hole with its axis vertically set; the receiving hole is a through hole; a slender metal tubular workpiece 600 is inserted into the receiving hole; the receiving hole serves to shield the outer wall of the workpiece 600.

[0057] A replacement device is provided inside the connecting cylinder 130; the replacement device is used to replace the quartz boat 200 while maintaining a vacuum in the delivery pipe 140. The replacement device includes an air extraction port 510, a replacement hole 520, and a turntable 530. The air extraction port 510 is located on the side wall of the connecting cylinder 130 and is used to connect a vacuum pump. The replacement hole 520 is opened on the upper end face of the connecting cylinder 130 and is located on one side of the delivery pipe 140; the turntable 530 is coaxially and rotatably mounted inside the connecting cylinder 130; a motor is fixed on the frame 100; the output shaft of the motor is fixedly connected to the turntable 530; the turntable 530 has two bearing through holes 540 symmetrically arranged about its own axis, one bearing through hole 540 is coaxial with the delivery pipe 140, and the other bearing through hole 540 is coaxial with and connected to the replacement hole 520; an air extraction hole 541 is provided between the side wall of the bearing through hole 540 and the side wall of the turntable 530.

[0058] Two adjusting grooves 542 are provided on both sides of the line connecting the axes of the two bearing through holes 540; each adjusting groove 542 corresponds to one bearing through hole 540; the adjusting groove 542 and the corresponding bearing through hole 540 are connected by a ventilation channel 543 provided in the turntable 530; a solenoid valve 544 is provided on the ventilation channel 543. When the quartz boat 200 needs to be replaced, the pushing device moves the old quartz boat 200 into the connecting cylinder 130 and into the bearing through hole 540. Next, the new quartz boat 200 is placed into the bearing through hole 540, which is coaxial with the replacement hole 520. Then, the turntable 530 is driven to rotate, and the turntable 530 carries the new quartz boat 200 to the delivery pipe 140. When the air extraction hole 541 of the bearing through hole 540 carrying the new quartz boat 200 and the air extraction port 510 on the connecting cylinder 130 are aligned and connected, the vacuum pump and solenoid valve 544 are started to extract the air from the bearing through hole 540 carrying the new quartz boat 200 and the corresponding adjustment groove 542 to form a vacuum. Then, the solenoid valve 544 is closed, and the turntable 530 is rotated again until the bearing through hole 540 carrying the old quartz boat 200 and the replacement hole 520 are coaxial. Then, the old quartz boat 200 is removed, thus ensuring that the quartz boat 200 is replaced without breaking the air. After the reaction, the turntable 530 is driven to rotate, so that the vacuum adjustment groove 542 corresponds to the conveying pipe 140, and the by-product particles generated in the conveying pipe 140 are extracted, thus avoiding contamination of the workpiece 600 by the by-product particles in the gas.

[0059] The gas delivery device includes a gas delivery cylinder 400, a dilution component, and a mixing component. The gas delivery cylinder 400 and the delivery pipe 140 are coaxially and fixedly connected to the upper end of the connecting cylinder 130. The gas delivery cylinder 400 and the delivery pipe 140 are connected through the connecting cylinder 130. Both the dilution component and the mixing component are located inside the gas delivery cylinder 400, with the mixing component positioned below the dilution component. The dilution component is used to dilute the precursor gas and the reactant gas separately with the carrier gas, while the mixing component is used to uniformly mix the separately diluted precursor gas and reactant gas before inputting them into the delivery pipe 140. This allows the carrier gas to perform primary dilution of the precursor gas and reactant gas separately through the dilution component, ensuring that the three gases only have a dilution effect at the dilution component, thus avoiding prolonged contact between the precursor gas and the reactant gas and the generation of by-product particles. Then, the mixing component rapidly and uniformly mixes the separately diluted precursor gas and reactant gas to ensure the uniformity of the subsequent plasma distribution.

[0060] The dilution assembly includes a main partition 410, a secondary partition 420, a first plate 430, a second plate 440, and auxiliary structures.

[0061] Both the main partition 410 and the secondary partition 420 are located in the upper section of the gas delivery cylinder 400. The main partition 410 is fixed radially to the inner wall of the gas delivery cylinder 400. The main partition 410 divides the upper section of the gas delivery cylinder 400 into two non-communicating input chambers. The secondary partition 420 is fixed radially to the inner wall of the gas delivery cylinder 400. The secondary partition 420 and the main partition 410 are fixedly connected in a cross shape. The secondary partition 420 divides each input chamber into a carrier gas chamber and a mating chamber. Carrier gas is introduced into the carrier gas chamber of both input chambers. Precursor gas is introduced into the mating chamber of one input chamber, and reaction gas is introduced into the mating chamber of the other input chamber.

[0062] The first plate 430 is located at the lower end of the main partition 410; the edge of the first plate 430 near the inner wall of the gas cylinder 400 is fixedly connected to the inner wall of the gas cylinder 400; the upper end of the first plate 430 is fixedly connected to the main partition 410; a distribution plate 450 is provided below the first plate 430; the distribution plate 450 is coaxially fixed inside the gas cylinder 400; a vertical strip 451 is fixed on the upper surface of the distribution plate 450; the lower end of the first plate 430 is fixedly connected to the vertical strip 451. The first plate 430 and the distribution plate 450 divide the middle section of the gas cylinder 400 into two non-conductive dilution chambers; each dilution chamber corresponds to an input chamber.

[0063] The second plate 440 is located at the lower end of the auxiliary partition 420; dilution gaps are formed between the two edges of the second plate 440 near the inner wall of the gas cylinder 400 and the inner wall of the gas cylinder 400; the size of the dilution gaps gradually increases from top to bottom; the upper end of the second plate 440 is fixedly connected to the auxiliary partition 420; the first plate 430 and the second plate 440 are fixedly connected; the first plate 430 and the second plate 440 are cross-shaped in cross section on a horizontal plane perpendicular to the axis of the delivery pipe 140; the second plate 440 divides each dilution chamber into a first chamber and a second chamber; the first chamber of the dilution chamber is connected to the carrier gas chamber of the corresponding input chamber, and the second chamber of the dilution chamber is connected to the mating chamber of the corresponding input chamber; the first chamber and the second chamber of the same dilution chamber are connected through the dilution gap; the first plate 430 and the second plate 440 are both spiral plates spiraling around the axis of the gas cylinder 400. They are used to guide the gas spiral downwards, causing the gas to move towards the dilution gap due to centrifugal force. Carrier gas is introduced into the carrier gas chambers of both input chambers via an air pump; precursor gas is introduced into the mating chamber of one input chamber, and reactant gas is introduced into the mating chamber of the other input chamber; one dilution chamber contains both carrier gas and precursor gas; the other dilution chamber contains both carrier gas and reactant gas. Guided by the first plate 430 and the second plate 440, the carrier gas and precursor gas are diluted and mixed at the dilution gaps of the corresponding dilution chambers, and the carrier gas and reactant gas are diluted and mixed at the dilution gaps of the corresponding dilution chambers.

[0064] The auxiliary structure is used to prevent the carrier gas from reacting with the other two gases and generating impurity particles as the dilution gap increases, causing the dilution and mixing of the carrier gas and the other two gases to change from a smooth to a violent process. The auxiliary structure includes an auxiliary cylinder 460; the auxiliary cylinder 460 is coaxially disposed within the gas delivery cylinder 400 and located within the dilution gap; the inner diameter of the auxiliary cylinder 460 is smaller than that of the gas delivery cylinder 400; the upper end of the auxiliary cylinder 460 is located below the upper end of the gas delivery cylinder 400; the upper end of the auxiliary cylinder 460 is fixedly connected to a second plate 440; secondary gaps are formed between the inner wall of the auxiliary cylinder 460 and the two edges of the second plate 440 near the inner wall of the gas delivery cylinder 400. The gas entering the auxiliary cylinder 460 is diluted and mixed at the secondary gaps; multiple auxiliary cylinders 460 are provided; the inner diameters of the multiple auxiliary cylinders 460 decrease progressively, and the upper end of the smaller inner diameter auxiliary cylinder 460 is located below the upper end of the adjacent larger inner diameter auxiliary cylinder 460. The presence of the auxiliary cylinder 460 prevents the diluted and mixed gas from affecting the dilution of the undiluted gas. At the same time, the dilution gap at the auxiliary cylinder 460 is divided into smaller sub-gap gaps, thereby preventing the carrier gas from diluting and mixing with the other two gases from changing from a stable state to a violent one.

[0065] The mixing assembly is located in the lower section of the gas delivery cylinder 400; the mixing assembly includes a first branch cylinder 470, a second branch cylinder 480, an outer hole 491, and an inner hole 492.

[0066] Multiple first and second cylinders 470 and 480 are arranged alternately in a vertical arrangement; the first and second cylinders 470 and 480 are coaxially arranged inside the gas delivery cylinder 400; the diameter of the first cylinder 470 is larger than that of the second cylinder 480; adjacent first and second cylinders 470 and 480 are fixedly connected; multiple first cylinders 470 and multiple second cylinders 480 constitute a mixing cylinder, and the upper end of the mixing cylinder is fixedly connected to the distribution plate 450; the space between the mixing cylinder and the gas delivery cylinder 400 is an outer cavity; the inside of the mixing cylinder is an inner cavity.

[0067] The first mixing cylinder 470 has multiple first mixing ports distributed circumferentially on its side wall; a first baffle 471 is rotatably mounted on the first mixing port; the first baffle 471 is rotatably mounted inside the first mixing port via a first rotating shaft; the axis of the first rotating shaft is parallel to the axis of the first mixing cylinder 470; a torsion spring connects the first baffle 471 and the first mixing cylinder 470.

[0068] The second mixing cylinder 480 has multiple second mixing ports distributed circumferentially on its side wall; a second baffle 481 is rotatably mounted on the second mixing port; the second baffle 481 is rotatably mounted inside the second mixing port via a second rotating shaft; the axis of the second rotating shaft is parallel to the axis of the second mixing cylinder 480; a torsion spring connects the second baffle 481 and the second mixing cylinder 480.

[0069] The outer hole 491 is a through hole opened on the distribution plate 450; the outer hole 491 is located on one side of the vertical bar 451; the outer hole 491 connects the outer cavity and a dilution cavity.

[0070] The inner hole 492 is a through hole opened on the distribution plate 450; the inner hole 492 is located on the other side of the vertical bar 451; the inner hole 492 connects the inner cavity and another dilution cavity. The precursor gas, diluted by the carrier gas, enters the outer cavity through the outer hole 491 from the dilution chamber. Simultaneously, the reactant gas, also diluted by the carrier gas, enters the inner cavity through the inner hole 492 from the dilution chamber. Since the diameter of the first dividing cylinder 470 is larger than that of the second dividing cylinder 480, the gas pressure inside the first dividing cylinder 470 is greater than the gas pressure outside it, thus pushing the first baffle 471 open from the inside out into the outer cavity. Conversely, the gas pressure inside the second dividing cylinder 480 is less than the gas pressure outside it, thus pushing the second baffle 481 open from the outside in into the inner cavity. This allows the two diluted gases to flow alternately inside and outside the mixing cylinder multiple times, ensuring rapid and uniform mixing of the diluted precursor gas and reactant gas, thereby guaranteeing the uniformity of the subsequent plasma distribution. The first baffle 471 and the second baffle 481 are inclined radially relative to the mixing cylinder when they open, causing the gas to form a vortex-like airflow inside and outside the mixing cylinder, promoting mixing. The first gate 471 and the second gate 481 are tilted in the same direction when they are opened. This causes the vortex-like airflow formed inside and outside the mixing cylinder to flow in opposite directions, further promoting uniform gas mixing.

[0071] The pushing device is used to move the quartz boat 200 within the conveying pipe 140 to the reactor 110. The pushing device includes a push rod 310, a limiting rod 320, a top plate 330, and a gas supply assembly. The push rod 310 is vertically arranged, with its lower end extending into the gas supply cylinder 400, and is slidably and rotatably engaged with the gas supply cylinder 400. A matching rod is fixed to the lower end of the push rod 310. The matching rod and the push rod 310 are perpendicular and T-shaped. The limiting rod 320 is vertically fixed to the upper end of the quartz boat 200 along its axis. Two limiting rods 320 are arranged parallel to each other. The distance between the positioning rods 320 is greater than the diameter of the mating rod and less than the length of the mating rod; the top plate 330 is located below the limiting rods 320; the top plate 330 is fixed on the quartz boat 200; when pushing the quartz boat 200, the push rod 310 is pushed so that the mating rod passes vertically between the two limiting rods 320, and then the push rod 310 is rotated so that the mating rod is locked between the top plate 330 and the limiting rods 320, so that the push rod 310 drives the quartz boat 200 to move;

[0072] The gas delivery assembly is used to deliver the three gases mixed by the mixing assembly to the workpiece 600 inside the receiving hole to improve the coating efficiency on the inner wall of the workpiece 600. The gas delivery assembly includes a gas delivery hole 341, a connecting hole 342, and a bellows 340. The gas delivery hole 341 is opened on the end face of the lower end of the push rod 310. The axis of the gas delivery hole 341 is vertically arranged. The connecting hole 342 is opened on the side wall of the push rod 310. The connecting hole 342 and the gas delivery hole 341 are connected. The bellows 340 is coaxially sleeved on the push rod 310. The rod 310 is located at the lower end of the mixing cylinder; the upper end of the bellows 340 is fixedly connected to the inner wall of the gas delivery cylinder 400, and the lower end is fixed with a sealing plate; the sealing plate is located below the connecting hole 342; the sealing plate and the push rod 310 rotate in cooperation; the three gases after being mixed by the mixing component enter the bellows 340, enter the gas delivery hole 341 through the connecting hole 342, and the three gases after being mixed are delivered to the workpiece 600 in the receiving hole through the gas delivery hole 341 to improve the coating efficiency of the inner wall of the workpiece 600.

[0073] In this embodiment, two gas delivery devices are provided; the two gas delivery devices are arranged one above the other, with the upper gas delivery device located inside the gas delivery cylinder 400 and the lower gas delivery device located inside the lower end of the delivery pipe 140; the mixed gas enters the interior of the workpiece 600 from both the upper and lower ends, thereby improving the coating efficiency.

[0074] Based on the above embodiments, the operating principle and process of this invention are as follows: In use, firstly, the quartz boat 200 carrying the workpiece 600 is moved into the reactor 110 by the push rod 310. The heating module heats the conveying pipe 140 through the reactor 110 to raise the temperature of the workpiece 600 to the target value (adjusted according to the film type). Secondly, gas is introduced: after the temperature stabilizes, carrier gas, precursor gas, and reactant gas are introduced in proportion. The chamber pressure is adjusted to the target value through the vacuum valve, and the flow and pressure are kept stable (fluctuation < ±2%). Carrier gas is introduced into the carrier gas chambers of both input chambers through an air pump; precursor gas is introduced into the mating chamber of one input chamber, and reactant gas is introduced into the mating chamber of the other input chamber; one dilution chamber contains carrier gas and precursor gas; the other dilution chamber contains carrier gas and reactant gas. Guided by the first plate 430 and the second plate 440, the carrier gas and the precursor gas are diluted and mixed at the dilution gap of the corresponding dilution chamber, and the carrier gas and the reactant gas are diluted and mixed at the dilution gap of the corresponding dilution chamber. The precursor gas, diluted by the carrier gas, enters the outer cavity through the outer hole 491 from the dilution chamber. Simultaneously, the reactant gas, diluted by the carrier gas, enters the inner cavity through the inner hole 492 from the dilution chamber. Since the diameter of the first dividing cylinder 470 is larger than that of the second dividing cylinder 480, when the gas passes through the first dividing cylinder 470, the gas pressure inside the first dividing cylinder 470 is greater than the gas pressure outside the first dividing cylinder 470, thereby pushing the first baffle 471 open from the inside to the outside into the outer cavity. When the gas passes through the second dividing cylinder 480, the gas pressure inside the second dividing cylinder 480 is less than the gas pressure outside the second dividing cylinder 480, thereby pushing the second baffle 481 open from the outside to the inside into the inner cavity. This allows the two diluted gases to flow alternately inside and outside the mixing cylinder multiple times, enabling the separately diluted precursor gas and reactant gas to mix rapidly and uniformly, thus ensuring the uniformity of the subsequent plasma distribution. The three gases, after being mixed by the mixing component, enter the bellows 340, pass through the connecting hole 342 into the air supply hole 341, and are then transported through the air supply hole 341 to the workpiece 600 inside the receiving hole to improve the coating efficiency on the inner wall of the workpiece 600.

[0075] When the quartz boat 200 needs to be replaced, the pushing device moves the old quartz boat 200 into the connecting cylinder 130 and into the bearing through hole 540. Next, the new quartz boat 200 is placed into the bearing through hole 540, which is coaxial with the replacement hole 520. Then, the turntable 530 is driven to rotate, and the turntable 530 carries the new quartz boat 200 to the delivery pipe 140. When the air extraction hole 541 of the bearing through hole 540 carrying the new quartz boat 200 and the air extraction port 510 on the connecting cylinder 130 are aligned and connected, the vacuum pump and solenoid valve 544 are started to extract the air from the bearing through hole 540 carrying the new quartz boat 200 and the corresponding adjustment groove 542 to form a vacuum. Then, the solenoid valve 544 is closed, and the turntable 530 is rotated again until the bearing through hole 540 carrying the old quartz boat 200 and the replacement hole 520 are coaxial. Then, the old quartz boat 200 is removed, thus ensuring that the quartz boat 200 is replaced without breaking the air. After the reaction, the turntable 530 is driven to rotate, so that the vacuum adjustment groove 542 corresponds to the conveying pipe 140, and the by-product particles generated in the conveying pipe 140 are extracted, thus avoiding contamination of the workpiece 600 by the by-product particles in the gas.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coating apparatus for exciting uniform plasma within a slender tube, characterized in that: include: The frame is arranged vertically, with a reactor at the lower end; the reactor contains a radio frequency plasma generator; a heating module is provided on the outer wall of the reactor; a connecting cylinder is fixed on the frame; the axis of the connecting cylinder is arranged vertically above the reactor; a conveying pipe is provided at the lower end of the connecting cylinder; the axis of the conveying pipe is parallel to the axis of the connecting cylinder; the lower end of the conveying pipe extends into the reactor; the upper end of the conveying pipe is fixedly connected to the connecting cylinder. A quartz boat is placed inside the delivery pipe; the quartz boat has a vertically oriented receiving hole; the receiving hole is a through hole; a replacement device is provided inside the connecting cylinder; the replacement device is used to replace the quartz boat while maintaining a vacuum inside the delivery pipe. A gas delivery device includes a gas delivery cylinder, a dilution component, and a mixing component; the gas delivery cylinder and the delivery pipe are coaxially and fixedly connected to the upper end of a connecting cylinder; the gas delivery cylinder and the delivery pipe are connected through the connecting cylinder; both the dilution component and the mixing component are located inside the gas delivery cylinder, with the mixing component located below the dilution component; the dilution component is used to dilute the precursor gas and the reactant gas separately with the carrier gas, and the mixing component is used to uniformly mix the separately diluted precursor gas and reactant gas before inputting them into the delivery pipe; A pushing device is used to move the quartz boat within the conveying pipe into the reactor. The dilution assembly includes a main partition, a secondary partition, a first plate, and a second plate; Both the main baffle and the auxiliary baffle are located in the upper section of the gas delivery cylinder; the main baffle is fixed radially to the inner wall of the gas delivery cylinder; the main baffle divides the upper section of the gas delivery cylinder into two non-communicating input chambers. The secondary partition is fixed radially to the inner wall of the gas delivery cylinder; the secondary partition and the main partition are fixedly connected in a cross shape; the secondary partition divides each input chamber into a carrier gas chamber and a matching chamber; the carrier gas chambers of both input chambers are vented with carrier gas; the matching chamber of one input chamber is vented with precursor gas, and the matching chamber of the other input chamber is vented with reaction gas; The first plate is located at the lower end of the main partition; the edge of the first plate near the inner wall of the gas cylinder is fixedly connected to the inner wall of the gas cylinder; the upper end of the first plate is fixedly connected to the main partition; a distribution plate is provided below the first plate; the distribution plate is coaxially fixed inside the gas cylinder; a vertical bar is fixed on the upper surface of the distribution plate; the lower end of the first plate is fixedly connected to the vertical bar. The first plate and the distribution plate divide the middle section of the gas delivery cylinder into two non-communicating dilution chambers; each dilution chamber corresponds to an input chamber. The second plate is located at the lower end of the auxiliary partition plate; dilution gaps are formed between the two edges of the second plate near the inner wall of the gas cylinder and the inner wall of the gas cylinder; the size of the dilution gaps gradually increases from top to bottom; the upper end of the second plate is fixedly connected to the auxiliary partition plate; the first plate and the second plate are fixedly connected; the first plate and the second plate are cross-shaped in cross section on a horizontal plane perpendicular to the axis of the delivery pipe; the second plate divides each dilution chamber into a first chamber and a second chamber; the first chamber of the dilution chamber is connected to the carrier gas chamber of the corresponding input chamber, and the second chamber of the dilution chamber is connected to the mating chamber of the corresponding input chamber; the first chamber and the second chamber of the same dilution chamber are connected through the dilution gap; both the first plate and the second plate are spiral plates spiraling around the axis of the gas cylinder; Guided by the first and second plates, the carrier gas and precursor gas are diluted and mixed at the dilution gaps of the corresponding dilution chambers, and the carrier gas and reactant gas are diluted and mixed at the dilution gaps of the corresponding dilution chambers.

2. The coating equipment for exciting uniform plasma in a slender tube according to claim 1, characterized in that: The dilution assembly also includes an auxiliary structure; the auxiliary structure is used to prevent the dilution and mixing of the carrier gas and the other two gases from becoming more drastic as the dilution gap increases.

3. The coating equipment for exciting uniform plasma in a slender tube according to claim 2, characterized in that: The auxiliary structure includes an auxiliary cylinder; The auxiliary cylinder is coaxially disposed inside the gas delivery cylinder and is located within the dilution gap; the inner diameter of the auxiliary cylinder is smaller than that of the gas delivery cylinder; the upper end of the auxiliary cylinder is located below the upper end of the gas delivery cylinder; the upper end of the auxiliary cylinder is fixedly connected to the second plate; a secondary gap is formed between the inner wall of the auxiliary cylinder and the two edges of the second plate near the inner wall of the gas delivery cylinder.

4. The coating apparatus for exciting uniform plasma inside a slender tube according to claim 3, characterized in that: Multiple auxiliary cylinders are provided; the inner diameter of the multiple auxiliary cylinders decreases successively, and the upper end of the auxiliary cylinder with the smaller inner diameter is located below the upper end of the adjacent auxiliary cylinder with the larger inner diameter.

5. A coating apparatus for exciting uniform plasma within a slender tube according to claim 4, characterized in that: The mixing assembly is located in the lower section of the gas delivery cylinder; the mixing assembly includes a first dividing cylinder, a second dividing cylinder, an outer hole, and an inner hole; Multiple first and second sub-cylinders are arranged alternately, one above the other; the first and second sub-cylinders are coaxially arranged inside the gas delivery cylinder; the diameter of the first sub-cylinder is larger than that of the second sub-cylinder; adjacent first and second sub-cylinders are fixedly connected; multiple first sub-cylinders and multiple second sub-cylinders constitute a mixing cylinder, and the upper end of the mixing cylinder is fixedly connected to the distribution plate; the space between the mixing cylinder and the gas delivery cylinder is an outer cavity; the space inside the mixing cylinder is an inner cavity. The first mixing cylinder has multiple first mixing ports distributed circumferentially on its side wall; a first baffle is rotatably mounted on the first mixing port; the first baffle is rotatably mounted inside the first mixing port via a first rotating shaft; the axis of the first rotating shaft is parallel to the axis of the first mixing cylinder; a torsion spring connects the first baffle and the first mixing cylinder. The second mixing cylinder has multiple second mixing ports distributed circumferentially on its side wall; a second baffle is rotatably installed on each of the second mixing ports; the second baffle is rotatably installed inside the second mixing port via a second rotating shaft; the axis of the second rotating shaft is parallel to the axis of the second mixing cylinder; a torsion spring connects the second baffle and the second mixing cylinder. The outer hole is a through hole opened on the distribution plate; the outer hole is located on one side of the vertical bar; the outer hole connects the outer cavity and a dilution cavity; The inner hole is a through hole opened on the distribution plate; the inner hole is located on the other side of the vertical bar; the inner hole connects the inner cavity and another dilution cavity.

6. The coating apparatus for exciting uniform plasma in a slender tube according to claim 5, characterized in that: The first and second gates are inclined radially relative to the mixing cylinder when they are opened; the first and second gates are inclined in the same direction when they are opened.

7. A coating apparatus for exciting uniform plasma within a slender tube according to claim 6, characterized in that: There are two gas delivery devices; the two gas delivery devices are arranged one above the other, with the upper gas delivery device located inside the gas delivery cylinder; the lower gas delivery device is located inside the lower end of the delivery pipe.

8. A coating apparatus for exciting uniform plasma within a slender tube according to claim 7, characterized in that: The pushing device includes a push rod, a limiting rod, a top plate, and an air supply assembly. The push rod is arranged vertically, with its lower end extending into the air supply cylinder and sliding vertically and rotating with the air supply cylinder. A matching rod is fixed to the lower end of the push rod. The matching rod is perpendicular to the push rod and forms a T-shape. The limiting rod is perpendicular to the axis of the push rod and fixed to the upper end of the quartz boat. Two limiting rods are arranged parallel to each other. The distance between the two limiting rods is greater than the diameter of the matching rod but less than the length of the matching rod. The top plate is located below the limiting rod and is fixed to the quartz boat. The air supply assembly includes an air supply port, a connecting hole, and a bellows. The air supply port is located on the lower end face of the push rod. The axis of the air supply port is vertically oriented. The connecting hole is located on the side wall of the push rod. The connecting hole and the air supply port are connected. The bellows is coaxially sleeved on the push rod and is located at the lower end of the mixing cylinder. The upper end of the bellows is fixedly connected to the inner wall of the air supply cylinder, and the lower end is fixed with a sealing disc. The sealing disc is located below the connecting hole. The sealing disc and the push rod are rotatably engaged.

9. A coating apparatus for exciting uniform plasma within a slender tube according to claim 8, characterized in that: The replacement device includes an air extraction port, a replacement hole, and a turntable; The air extraction port is located on the side wall of the connecting cylinder; The replacement hole is located on the upper end face of the connecting cylinder and on one side of the conveying pipe; The turntable is coaxially and rotatably installed inside the connecting cylinder; the turntable has two load-bearing through holes symmetrically arranged about its own axis, one above the other; initially, one load-bearing through hole is coaxial with the conveying pipe, and the other load-bearing through hole is coaxial with and connected to the replacement hole; an air extraction hole is provided between the side wall of the load-bearing through hole and the side wall of the turntable; Two adjustment grooves are provided on both sides of the line connecting the axes of the two bearing through holes; each adjustment groove corresponds to one bearing through hole; the adjustment groove and the corresponding bearing through hole are connected by a ventilation channel provided in the turntable; a solenoid valve is provided on the ventilation channel.

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