Sequential-control multi-path parallel gas replacement system and method thereof

Abstract

The invention discloses a sequential-control multi-path parallel gas replacement system and a sequential-control multi-path parallel gas replacement method, and relates to the technical field of mixing according to phases to be mixed. Comprising a middle gas reservoir, a vacuum pump and a plurality of to-be-replaced cavities, the to-be-replaced cavities are connected to the same gathering pipeline in parallel and connected to a three-position four-way valve, and the vacuum pump is connected with an inert gas source and the to-be-replaced cavities through the three-position four-way valve. And the middle gas reservoir is connected with a gathering pipeline of the to-be-replaced cavities through the three-position four-way valve. The problems that in the prior art, multi-cavity parallel gas replacement cannot be achieved, an intermediate gas reservoir recovery mechanism is lacked, inert gas consumption is too high, residual gas treatment efficiency is low, and the purity is insufficient are solved, and the purposes that the gas cyclic utilization rate is increased, the purity is precisely controlled, and energy consumption is reduced are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of mixing phases to be mixed, and in particular to mixing gas with gas. Background Art

[0002] With the development of semiconductor manufacturing technology, the requirements for high-performance cryogenic refrigerators are getting higher and higher. For example, it is necessary to thoroughly replace the gas in the refrigerator to ensure that it has a high-purity helium environment, thereby improving the performance of the refrigerator. At the same time, in the existing technology, gas replacement often adopts the following methods: 1. Purge replacement method: continuously introduce inert gas (such as nitrogen, argon, etc.) to dilute the original gas, but it has low efficiency, high gas consumption, and high residual gas concentration. It is usually used for gas replacement in large-volume containers or pipelines; 2. Inflation after single vacuuming: It is difficult to completely remove residual gas, especially in complex cavity structures where dead space is prone to exist. It can be seen that the existing method is difficult to take into account both gas replacement efficiency and purity after replacement, and the pipeline is complex and the control logic is single. At the same time, using the existing method, gas replacement can usually only be performed for one cavity at a time. When there are multiple cavities that need to carry out gas replacement operations, the work efficiency is low.

[0003] For example, Chinese patent publication number CN119215707A discloses an automatic gas distribution system and gas distribution method suitable for multiple gas detection, and provides the following technical solutions: the present invention provides a novel optical fiber wireless communication method for underground coal mines, comprising the following steps: The present application discloses an automatic gas distribution system and gas distribution method suitable for multiple gas detection, belonging to the field of dynamic gas distribution technology. The automatic gas distribution system of the present application has a simple structure, and can achieve rapid switching of multiple gases to be tested by controlling the on-off coordination of a four-way valve and each gas path; based on the idea of making it ready for use, it realizes gas distribution testing of easily decomposable gases or volatile gases such as ozone, and also adds an environmental baseline recovery process during the gas distribution test, so that the gas in the test chamber is in the initial state before and after the sensor test; at the same time, by combining the four-way valve with the premixing process control, the gas is premixed in the mixing chamber before entering the test chamber for sensor testing. The premixing process further prevents the mutual contamination of gases in the pipeline before and after the gas switching, and also makes the gas mixing more uniform, reduces errors, thereby making the sensor test more accurate. However, the above-mentioned automatic gas distribution system and gas distribution method suitable for multiple gas detection cannot realize multi-cavity parallel gas replacement, and lacks an intermediate gas storage recovery mechanism, resulting in high inert gas consumption, difficulty in achieving a high-purity environment, and inability to efficiently handle residual gas. Summary of the Invention

[0004] This invention addresses the existing challenges of multi-chamber parallel gas exchange, including the inability to achieve multi-chamber parallel gas exchange, the lack of an intermediate gas reservoir recovery mechanism, excessive inert gas consumption, inefficient residual gas treatment, and insufficient purity. It proposes a time-sequentially controlled multi-path parallel gas exchange system and method, achieving improved gas recycling efficiency, precise purity control, and reduced energy consumption. In particular, the intermediate gas reservoir allows for temporary gas storage, reducing waste. In some cases, the intermediate gas reservoir's volume can be actively adjusted, eliminating the need for a vacuum chamber to inflate the next chamber.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A time-controlled multi-channel parallel gas replacement system includes: an intermediate gas reservoir and a vacuum pump and a plurality of cavities to be replaced, each of which is connected in parallel to the same collecting pipeline and connected to a three-position four-way valve. The vacuum pump and the inert gas source and the cavities to be replaced are interconnected through the three-position four-way valve, and the intermediate gas reservoir and the collecting pipeline of the cavities to be replaced are connected through the three-position four-way valve.

[0006] The parallel structure and centralized control of the three-position four-way valve enable parallel replacement of multiple cavities, significantly improving operational efficiency while reducing piping complexity and lowering leakage risks.

[0007] A time-controlled multi-channel parallel gas replacement method comprises the following steps: S1: Pump the first cavity to be replaced to the target pressure and determine whether the gas purity meets the standard. If it does, proceed to step S3; if not, proceed to step S2; S2: Fill the first cavity to be replaced with inert gas to the target pressure and then let it stand, evacuate the second cavity to be replaced to the target pressure, fill the inert gas in the first cavity to be replaced with the intermediate gas reservoir, fill the gas in the intermediate gas reservoir with the second cavity to be replaced with the intermediate gas reservoir and then let it stand, returning to step S1; S3: The second cavity to be replaced is evacuated to the target pressure, and the gas purity is determined to be up to standard. If not, the process proceeds to step S4. If so, the replacement is completed. S4: Fill the second cavity to be replaced with inert gas to the target pressure, let it stand, and return to step S3.

[0008] Preferably, the working state of the three-dimensional four-way valve is controlled by a timing controller, and a stop valve is provided on the pipeline from the collecting pipeline to each cavity to be replaced, and the stop valve is controlled by the timing controller.

[0009] The valves and shut-off valves are uniformly controlled by the timing controller to ensure the precise timing switching of the replacement process of each cavity, improve the degree of automation and avoid human operation errors.

[0010] Preferably, the inert gas source is provided with a pressure reducing valve and a mass flow controller, and the cavity to be replaced is provided with a second pressure sensor to monitor the vacuum degree in real time and feed back to the timing controller.

[0011] The pressure reducing valve and mass flow controller combined with pressure sensor feedback can accurately control the inflation pressure and flow, adapt to the pressure bearing capacity of different cavities, and improve the safety and gas purity of the replacement process.

[0012] Preferably, the intermediate gas reservoir stores gas from the cavity to be replaced, and the gas in the upper cavity to be replaced is transferred to the next cavity to be replaced through the intermediate gas reservoir for preliminary replacement, and is transferred to the lower cavity to be replaced in turn.

[0013] Through the transit and reuse of the intermediate gas storage, the same inert gas can be recycled for the initial replacement of multiple cavities, greatly reducing the consumption of rare gas and saving costs.

[0014] Preferably, the intermediate gas reservoir adopts a cylindrical cavity with a movable piston arranged inside. The volume can be actively adjusted by pushing the piston position through a driving mechanism. The movable piston and the inner wall of the cavity of the intermediate gas reservoir adopt a high-precision sealing ring.

[0015] The adjustable volume design enables the intermediate gas storage to flexibly adapt to the gas transfer needs of different capacities, and cooperates with high-precision sealing rings to ensure airtightness, improve gas utilization and reduce residue.

[0016] Preferably, the intermediate gas reservoir is provided with a first pressure sensor and a position sensor, and the timing controller controls and adjusts the piston position according to the gas replacement stage.

[0017] The sensor provides real-time feedback of pressure and piston position data, helping the timing controller dynamically optimize the volume adjustment strategy, further improving gas transfer efficiency and system response speed.

[0018] Preferably, a mass spectrometer is provided at the vacuum pump, and the mass spectrometer is a helium mass spectrometer.

[0019] The helium mass spectrometer can detect the purity of the gas after replacement with high precision, ensuring that the final environment meets strict requirements. At the same time, feedback control is used to terminate the replacement process to avoid excessive consumption of resources.

[0020] Preferably, step S2 includes the following steps: S2.1: Connecting an inert gas source to the first cavity to be displaced, filling the first cavity to be displaced with inert gas to a target pressure, and then allowing the inert gas to stand; S2.2: Connect the vacuum pump to the second cavity to be replaced and evacuate to the target pressure; S2.3: Adjust the volume of the intermediate gas reservoir, connect the first cavity to be replaced with the intermediate gas reservoir, and fill the inert gas in the cavity into the intermediate gas reservoir; S2.4: Connect the intermediate gas reservoir and the second cavity to be replaced, fill the gas in the intermediate gas reservoir into the second cavity to be replaced, and then let it stand.

[0021] By using time-sequential control to recycle inert gas and replace multiple cavities in parallel, consumption can be reduced, efficiency can be improved, and purity can be ensured to meet standards.

[0022] Preferably, step S1 specifically includes: connecting the vacuum pump with the first cavity to be replaced, and evacuating the cavity to the target pressure; step S3 specifically includes: connecting the vacuum pump with the second cavity to be replaced, and evacuating the cavity to the target pressure, detecting the gas purity by a mass spectrometer to determine whether the gas purity meets the standard; if not, proceeding to step S4; if so, completing the replacement.

[0023] Compared with the prior art, the present invention has the following beneficial effects.

[0024] 1. This invention achieves collaborative operation among multiple chambers by connecting multiple chambers to a common pipeline and centrally controlling gas path switching with a three-position, four-way valve. Compared to traditional series connections, this design reduces pipeline complexity and the number of connection points. Furthermore, through precise opening and closing control of the shut-off valves by a timing controller, multiple chambers can perform operations such as vacuuming, inflation, or gas transfer in parallel. Furthermore, the integrated control of the three-position, four-way valve eliminates the frequent switching required by traditional multi-valve systems, reducing leakage risks and maintenance costs.

[0025] 2. The intermediate gas reservoir serves as an inert gas transfer hub. By storing residual gas from the previous chamber and transferring it to the next chamber, the same gas can be recycled for multiple replacement stages, reducing rare gas consumption. The intermediate gas reservoir utilizes a movable piston and active volume adjustment design, combined with real-time feedback from pressure and position sensors, to dynamically match the gas capacity requirements of different chambers.

[0026] 3. This invention integrates a helium mass spectrometer, a pressure sensor, and a mass flow controller to create a multi-dimensional detection and feedback mechanism. The timing controller dynamically adjusts the number of pumping and filling cycles and inflation parameters based on real-time analysis of gas purity, pressure, and volume data. If the purity of the second chamber to be replaced is detected to be below standard, the refilling process is automatically triggered, and a pressure relief valve is used to limit peak pressure to prevent overpressure risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a time-sequentially controlled multi-channel parallel gas replacement system of the present invention.

[0028] Figure 2The present invention provides a flow chart of a time-series controlled multi-channel parallel gas replacement method. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present disclosure more apparent, embodiments of the present disclosure are described in further detail below with reference to the accompanying drawings. The proportions of the components herein are not drawn to scale, and the proportions and dimensions shown in the accompanying drawings are not intended to limit the essential technical solutions of the present disclosure. These embodiments do not describe all details in detail, nor do they limit the present disclosure to the specific embodiments described.

[0030] See also Figure 1-2 As shown, a time-controlled multi-channel parallel gas replacement system includes: an intermediate gas reservoir and a vacuum pump and several cavities to be replaced, each of the cavities to be replaced is connected in parallel to the same collecting pipeline and connected to a three-position four-way valve, the vacuum pump and the inert gas source and the cavities to be replaced are interconnected through the three-position four-way valve, and the intermediate gas reservoir and the collecting pipeline of the cavities to be replaced are connected through the three-position four-way valve.

[0031] A time-controlled multi-channel parallel gas replacement method comprises the following steps: S1: Pump the first cavity to be replaced to the target pressure and determine whether the gas purity meets the standard. If it does, proceed to step S3; if not, proceed to step S2; S2: Fill the first cavity to be replaced with inert gas to the target pressure and then let it stand, evacuate the second cavity to be replaced to the target pressure, fill the inert gas in the first cavity to be replaced with the intermediate gas reservoir, fill the gas in the intermediate gas reservoir with the second cavity to be replaced with the intermediate gas reservoir and then let it stand, returning to step S1; S3: The second cavity to be replaced is evacuated to the target pressure, and the gas purity is determined to be up to standard. If not, the process proceeds to step S4. If so, the replacement is completed. S4: Fill the second cavity to be replaced with inert gas to the target pressure, let it stand, and return to step S3.

[0032] like Figure 1 In one embodiment shown, Figure 1This is a schematic diagram of a time-controlled, multi-channel, parallel gas replacement system according to the present invention. The system's core architecture consists of an intermediate gas reservoir, a vacuum pump, an inert gas source, several chambers to be replaced, and a control unit. Each chamber to be replaced is connected in parallel to a common pipeline, which is connected to the vacuum pump, inert gas source, and intermediate gas reservoir via a three-position, four-way valve. The three-position, four-way valve utilizes a centralized control mode, with three working ports corresponding to the vacuum pump interface, the inert gas source interface, and the intermediate gas reservoir interface, respectively. The fourth port is connected to the chamber's central pipeline, enabling precise control of the gas path direction by switching the valve body position. The intermediate gas reservoir utilizes a cylindrical cavity structure with a movable piston assembly internally configured. The piston and the inner wall of the cavity are sealed with a fluororubber or metal bellows seal to achieve a high-precision, airtight fit. The drive mechanism utilizes a stepper motor, linear motor, or pneumatic device, which can propel the piston axially to dynamically adjust the effective volume. A first pressure sensor and a position sensor are integrated into the gas reservoir body to monitor internal gas pressure and piston displacement in real time.

[0033] Independent stop valves are installed on the branch pipelines from the aggregation pipeline to each cavity to be replaced, and all stop valves and three-position four-way valves are controlled by the timing controller. The timing controller has a built-in multi-channel output module, which can synchronize and coordinate the opening and closing timing of the valves according to the preset program. The output end of the inert gas source is equipped with a pressure reducing valve and a mass flow controller to form a pressure-flow dual regulation mechanism. Its output parameters are fed back in a closed loop through the second pressure sensor set in the cavity to be replaced. A helium mass spectrometer is installed at the inlet of the vacuum pump to detect the purity of the exhaust gas in real time. The intermediate gas reservoir realizes the gas transfer function through the adjustable volume design. During the replacement process, it can receive the gas discharged from the upper cavity, and transfer it to the next cavity after volume adjustment to complete the initial replacement, forming a hierarchical gas utilization chain.

[0034] The control logic of the piston-type intermediate gas storage includes a dynamic volume adjustment mechanism: the timing controller accurately controls the action of the drive mechanism according to the characteristic requirements of the replacement stage (vacuuming, filling, and transfer charging), combined with the pressure sensor data and position sensor feedback. For example, in the storage stage, the drive mechanism pushes the piston backward to increase the volume to accommodate more gas; in the transfer charging stage, the piston is pushed forward to reduce the volume, and the output pressure is increased through mechanical compression. The system is equipped with an overpressure protection valve and an emergency exhaust channel, and the safety mechanism is automatically activated when it detects that the pressure exceeds the preset threshold. The drive mechanism adopts a dual-path motor or redundant pneumatic circuit design to ensure the reliability of the adjustment action. The replacement process of each cavity follows the standardized operation sequence of "vacuuming-inert gas filling-residual gas transfer", and the parallel operation of multiple cavities is achieved through the directional switching of the three-position four-way valve and the coordinated action of the stop valve.

[0035] The present invention has the following advantages: through the centralized control of the three-position four-way valve and the parallel pipeline architecture, the system significantly improves the efficiency of multi-cavity replacement operations, and can achieve several times the throughput increase in typical applications. The adjustable volume design of the intermediate gas reservoir combined with high-precision sealing technology greatly improves the gas transfer utilization rate and reduces the inert gas consumption compared to the traditional fixed volume system. The millisecond-level synchronous control of the valve action by the timing controller eliminates manual operation errors and controls the process switching accuracy within a smaller error range. The pressure-flow dual closed-loop regulation system can adapt to a wide pressure range of working conditions, and cooperates with the detection accuracy of the helium mass spectrometer to ensure that the output environment purity meets the process requirements. The mechanical compression function of the movable piston improves the efficiency of the transfer pressure increase, and the redundant drive design ensures the reliability of the continuous operation of the system. The graded gas reuse mechanism can greatly improve the gas circulation utilization rate in batch processing scenarios, and is particularly suitable for operating environments with precious inert gases such as argon and helium. The dynamic volume adjustment strategy enables the intermediate gas reservoir to flexibly adapt to the requirements of cavities of different capacities. The safety protection system is implemented through triple pressure monitoring (cavity pressure, gas reservoir pressure, pipeline pressure) and automatic emergency response mechanism.

[0036] In another embodiment, the device of the present invention includes a vacuum pump, a three-position four-way valve, an inert gas source, a cavity to be replaced and an intermediate gas reservoir. The four interfaces of the three-position four-way valve are respectively connected to the vacuum pump, the cavity to be replaced, the intermediate gas reservoir and the inert gas source. The working state of the three-position four-way valve is controlled by a timing controller; the intermediate gas reservoir is used to store the inert gas from the cavity to be replaced, and the inert gas in the upper-level cavity to be replaced is transferred through the intermediate gas reservoir to the next cavity to be replaced for preliminary replacement, and is transferred to the lower-level cavity to be replaced in turn.

[0037] The number of cavities to be replaced is n, n≥1. When n≥2, each cavity to be replaced is connected in parallel to the same collecting pipeline and then connected to the three-position four-way valve interface. A stop valve is provided on the pipeline between each cavity to be replaced and the collecting pipeline, and the stop valve is controlled by a timing controller.

[0038] The vacuum pump can be connected to or integrated with a helium mass spectrometer, which detects the purity of the gas after displacement. The volume of the intermediate gas reservoir can be actively adjusted. The inert gas source includes a pressure reducing valve and a mass flow controller. The pressure control during the inert gas filling phase is determined by the pressure capacity of the cavity to be displaced. The timing controller determines the termination of the displacement process based on a preset number of cycles or gas purity feedback. A pressure sensor is installed in the cavity to be displaced to monitor the vacuum level in real time and provide feedback to the timing controller.

[0039] like Figure 2 In one embodiment shown, Figure 2 The present invention provides a flow chart of a time-series controlled multi-channel parallel gas replacement method.

[0040] This method is implemented using a time-series controlled, multi-channel, parallel gas replacement system. The specific process includes the following core steps: Step S1: Initiate the initial replacement process in the first chamber to be replaced. A time-series controller switches a three-position, four-way valve to the vacuum pump path, evacuating the first chamber to a preset target pressure. Gas purity is then tested using a helium mass spectrometer. If the purity meets the target, the process proceeds directly to Step S3; otherwise, the process proceeds to Step S2 for further processing.

[0041] Step S2: Execute the inert gas circulation replacement process, which includes four sub-steps: Step S2.1: The timing controller switches the three-position four-way valve to the inert gas source path and simultaneously opens the stop valve corresponding to the first cavity. The mass flow controller adjusts the inflation rate to fill the first cavity with inert gas to the target pressure. After completion, the cavity is left to stand for 30-120 seconds to achieve uniform diffusion of the gas.

[0042] Step S2.2: During the execution of step S2.1, pretreatment of the second chamber is started in parallel. The timing controller switches the three-position four-way valve to the vacuum pump path, opens the stop valve of the second chamber, and evacuates it to the same target pressure.

[0043] Step S2.3: Adjust the intermediate gas reservoir volume to accommodate gas transfer requirements. Based on the gas volume data for the first chamber, the timing controller drives the piston of the intermediate gas reservoir backward to expand the volume. It then switches the three-position, four-way valve to the intermediate gas reservoir passage, connecting the first chamber and the intermediate gas reservoir, transferring the inert gas in the first chamber to the intermediate gas reservoir for temporary storage.

[0044] Step S2.4: The timing controller switches the three-position four-way valve to the intermediate gas reservoir output path, drives the piston forward to reduce the volume to pressurize the output gas, and at the same time opens the second cavity stop valve to fill the gas in the intermediate gas reservoir into the second cavity to the target pressure. After standing, return to step S1 for the next round of testing.

[0045] Step S3: Initiate final purity verification of the second chamber. The timing controller switches the three-position, four-way valve to the vacuum pump path, evacuating the second chamber to the target pressure. Gas purity is then tested using a helium mass spectrometer. If the target is met, replacement is complete; otherwise, the process proceeds to step S4.

[0046] Step S4: Replenish and replace the second chamber. The timing controller switches the three-position four-way valve to the inert gas source path, directly filling the second chamber with fresh inert gas to the target pressure. After standing, return to step S3 to retest the purity until it meets the target.

[0047] Throughout the entire process, the timing controller achieves precise control through the following methods: Valve coordinated control: The port switching of the three-position four-way valve (vacuum pump, inert gas source, intermediate gas reservoir) is strictly synchronized with the opening and closing of the stop valves of each cavity to avoid cross contamination of the gas path.

[0048] Dynamic adjustment of the intermediate gas reservoir: Based on the real-time data fed back by the pressure sensor, the drive mechanism accurately adjusts the piston position.

[0049] Closed-loop purity testing: The helium mass spectrometer analyzes residual gas composition in real time during the vacuum stage. The purity judgment threshold can be dynamically configured through software, and the test results directly trigger the subsequent step switching.

[0050] Parallel processing mechanism: The vacuuming, inflation, and transfer operations of the first and second cavities are performed alternately under timing control. For example, steps S2.1 and S2.2 can be partially overlapped to achieve multi-cavity parallel operation.

[0051] This method achieves a double breakthrough in multi-cavity gas replacement efficiency and resource utilization through timing control and dynamic adjustment of the intermediate gas reservoir. In terms of efficiency, the centralized control of the three-position four-way valve shortens the cavity switching time to less than a few seconds. Combined with the parallel processing mechanism, the system throughput is improved compared to the traditional single-channel series mode. The adjustable volume design of the intermediate gas reservoir, combined with the gas transfer and reuse strategy, reduces the consumption of inert gas. Especially in the application of expensive gases such as helium, the cost of a single operation can be greatly reduced. In terms of purity control, the dual feedback mechanism of the helium mass spectrometer and the pressure sensor greatly improves the accuracy of gas purity detection. At the same time, through the molecular diffusion balance effect during the static stage, local concentration deviations are avoided, ensuring that the replacement uniformity error is small.

[0052] In terms of safety, the coordinated design of dynamic volume regulation and overpressure protection valves can control pressure fluctuations within a narrow range, preventing damage to the chamber due to overpressure. The redundant drive mechanism reduces the failure rate of intermediate gas reservoir regulation. In terms of economic benefits, this method can shorten the total operation time and significantly improve equipment utilization. The recycling and reuse of inert gas significantly reduces annual consumption. In terms of technical compatibility, this method is suitable for environments ranging from atmospheric pressure to high pressure and can be expanded to various gas types such as hydrogen and sulfur hexafluoride.

[0053] In another embodiment, the specific method is as follows: 1) Connecting the vacuum pump to the first chamber to be replaced, evacuating the chamber to the target pressure, and determining whether the gas purity meets the standard; 2) connecting an inert gas source to the first cavity to be displaced, filling the first cavity to be displaced with the inert gas to a target pressure, and then allowing the inert gas to stand; 3) Connect the vacuum pump to the second chamber to be replaced, evacuate to the target pressure, and determine whether the gas purity meets the standard; 4) connecting the first cavity to be replaced with the intermediate gas reservoir, and filling the inert gas in the cavity into the intermediate gas reservoir; 5) connecting the intermediate gas reservoir and the second cavity to be replaced, filling the gas in the intermediate gas reservoir into the second cavity to be replaced and then allowing it to stand; 6) Repeat steps 1) to 5) until the gas purity in the first chamber to be replaced reaches the set value; 7) Repeat step 3); 8) connecting the second cavity to be replaced with an inert gas source, filling the second cavity to be replaced with the inert gas to a target pressure, and then allowing the inert gas to stand; 9) Repeat steps 7) and 8) until the gas purity in the second cavity to be replaced reaches the set value, and the replacement process ends.

[0054] In another embodiment, this embodiment provides a gas replacement system and method using the number of replacement cycles as a judgment condition. The cavity to be replaced is a cavity with a volume of 10L, and the initial atmosphere is air; the inert gas source is 0.1MPa helium. After the replacement process starts, a vacuum pump (ultimate vacuum degree ≤1×10-3Pa) is used to extract the air in the cavity and pump it to 0.1Pa for about 3 minutes. The three-position four-way valve passage is adjusted by a timing controller so that the cavity is connected to the helium source, and helium is filled into the cavity, and pressure equilibrium is reached after 30 seconds. Repeat the above steps until the vacuum-fill cycle is completed 5 times. The purity of the helium in the cavity was tested, and it was found that the purity of the helium reached 99.97%. Specifically: Three-position four-way valve: It adopts electromagnetically driven high vacuum valve, and the four interfaces are marked as P (vacuum pump), G (inert gas source), C (cavity to be replaced), and B (intermediate gas reservoir).

[0055] Step 1: System Preparation Connect the cavity to be replaced (initially containing air) to the system through the flange and check that all valves are closed; Start the vacuum pump and preheat for 20 minutes. After the pump body temperature stabilizes at 50℃±3℃, open the roughing valve and pre-pump the main line to below 1Pa. The helium source pressure reducing valve was adjusted to 0.1 MPa output, and the MFC was set to the maximum flow mode (50 sccm).

[0056] Step 2: First vacuum operation The timing controller drives the three-position four-way valve to switch to the PC path (the vacuum pump is directly connected to the chamber); The vacuum pump runs at full power and monitors the cavity pressure curve in real time. When the pressure drops to 0.1 Pa (which takes about 3 minutes), the pressure sensor sends a signal to the controller. The system automatically closes the roughing valve and keeps the molecular pump running to maintain the back vacuum.

[0057] Step 3: Initial Helium Filling The three-position four-way valve is switched to a path where the helium source directly passes through the cavity; The chamber was inflated with gas at a flow rate of 50 sccm, and the chamber pressure rose to 0.08 MPa after 30 seconds; Let it stand for 60 seconds to allow the gas to diffuse evenly and eliminate local concentration gradients.

[0058] Step 4: Loop process execution Repeat steps 2-3 to complete the cycle. The pressure recovery curve is recorded after each cycle. The actual measured total time for 5 cycles is about 35 minutes.

[0059] The helium concentration Q after each inflation can be estimated by the partial pressure law. After the fifth cycle, the theoretical purity reaches 99.93%, which is consistent with the measured value of 99.97%.

[0060] Step 5: Termination and Verification After completing the fifth cycle, the three-position four-way valve switches to the BC path, temporarily storing the helium in the cavity in the intermediate gas reservoir.

[0061] The residual gas analyzer (RGA) was used to detect through the vacuum pump sampling port to confirm that the O2 and N2 peak intensities were below the detection limit.

[0062] The system automatically generates a report containing the time-pressure curve of each cycle, total helium consumption and final purity data.

[0063] Dead space processing optimization: The cavity vibration motor is turned on at the end of the vacuum to promote the desorption of attached gas. Pulse pressure fluctuations are used in the inflation stage to destroy the laminar boundary layer and improve the uniformity of replacement.

[0064] Resource recycling: The helium stored in the intermediate gas reservoir can be used for primary replacement in the next cavity in multi-cavity mode. Although this embodiment operates in a single cavity, the system has reserved a parallel interface, which can increase the helium utilization rate by more than 40% when expanded.

[0065] Security and exception handling mechanism: Overpressure protection: When the chamber pressure is greater than 0.12MPa, the helium source will be immediately shut down and the safety pressure relief valve will be opened; Vacuum failure detection: If the pressure does not reach 0.2Pa after 3 minutes of vacuuming, it is determined to be a leak and an audible and visual alarm is triggered; Helium saving mode: When a purity jump in a cycle reaches the target, the cycle can be manually terminated to save gas.

[0066] In another embodiment, different from the previous embodiment, a mass spectrometer is integrated at the vacuum pump to monitor the purity of the inert gas in the extracted gas in real time. When the purity of the inert gas reaches 99.99%, the cycle is terminated and a total of 8 pumping-filling cycles are performed. When there is a higher requirement for the purity of the replaced gas, a two-stage vacuum pump (rotary vane pump + molecular pump) can be used, and the ultimate vacuum degree can reach 1×10 -4 Pa.

[0067] In summary, the present invention has the following beneficial effects: 1. By transferring inert gas through the intermediate gas reservoir, the same inert gas can participate in the replacement of multiple cavities, which can effectively reduce the consumption of inert gas and reduce the replacement cost.

[0068] 2. The vacuuming and inflation gas paths are separated by a single valve control, eliminating the need to disassemble the equipment between the vacuuming and inflation processes, reducing leakage risks and maintenance costs. At the same time, the alternating cycle of vacuuming and inflation can significantly reduce the residual gas in the dead space, resulting in higher gas replacement efficiency and saving more than 30% time compared to traditional methods.

[0069] 3. By rationally configuring the size of the vacuum pump and the capacity of the inert gas source, gas replacement in multiple cavities can be carried out in parallel, significantly improving operational efficiency.

[0070] The present invention is not limited to the above-mentioned embodiments. Regardless of any changes in shape or material composition, any structural design provided by the present invention is a variation of the present invention and should be considered within the scope of protection of the present invention.

Claims

1. A time-controlled multi-channel parallel gas replacement system, characterized in that: include: An intermediate gas reservoir, a vacuum pump, and several cavities to be replaced, each of which is connected in parallel to the same collecting pipeline and connected to a three-position four-way valve. The vacuum pump, the inert gas source, and the cavities to be replaced are interconnected through the three-position four-way valve, and the intermediate gas reservoir and the collecting pipeline of the cavities to be replaced are connected through the three-position four-way valve.

2. A time-controlled multi-channel parallel gas replacement system according to claim 1, characterized in that: The working state of the three-dimensional four-way valve is controlled by a timing controller. A stop valve is provided on the pipeline from the collecting pipeline to each cavity to be replaced, and the stop valve is controlled by the timing controller.

3. The time-controlled multi-channel parallel gas replacement system according to claim 2, characterized in that: The inert gas source is provided with a pressure reducing valve and a mass flow controller, and the cavity to be replaced is provided with a second pressure sensor to monitor the vacuum degree in real time and feed back to the timing controller.

4. A time-controlled multi-channel parallel gas replacement system according to claim 2 or 3, characterized in that: The intermediate gas reservoir stores gas from the cavity to be replaced. The gas in the upper cavity to be replaced is transferred through the intermediate gas reservoir to the next cavity to be replaced for preliminary replacement, and is transferred to the lower cavity to be replaced in turn.

5. The time-controlled multi-channel parallel gas replacement system according to claim 4, characterized in that: The intermediate gas reservoir adopts a cylindrical cavity with a movable piston arranged inside. The volume can be actively adjusted by pushing the piston position through a driving mechanism. The movable piston and the inner wall of the cavity of the intermediate gas reservoir adopt a high-precision sealing ring.

6. The time-controlled multi-channel parallel gas replacement system according to claim 5, characterized in that: The intermediate gas reservoir is provided with a first pressure sensor and a position sensor, and the timing controller controls and adjusts the piston position according to the gas replacement stage.

7. A time-controlled multi-channel parallel gas replacement system according to claim 4 or 5, characterized in that: A mass spectrometer is provided at the vacuum pump, and the mass spectrometer is a helium mass spectrometer.

8. A time-sequentially controlled multi-channel parallel gas replacement method, using a time-sequentially controlled multi-channel parallel gas replacement system according to any one of claims 1 to 7, characterized in that: include: S1: Pump the first cavity to be replaced to the target pressure and determine whether the purity meets the standard. If yes, proceed to step S3; otherwise, proceed to step S2; S2: After the inert gas is filled into the first cavity to be replaced to the target pressure, the second cavity to be replaced is pumped to the target pressure, the gas in the first cavity to be replaced is filled into the intermediate gas reservoir, and the gas in the intermediate gas reservoir is filled into the second cavity to be replaced, and then the process returns to step S1; S3: Pump the second cavity to be replaced to the target pressure and determine whether the purity meets the standard. If not, proceed to step S4. If yes, the replacement is completed. S4: After the inert gas is filled into the second cavity to be replaced to the target pressure, the process returns to step S3.

9. The time-series controlled multi-channel parallel gas replacement method according to claim 8, characterized in that: The step S2 comprises the following steps: S2.1: Connecting an inert gas source to the first cavity to be displaced, filling the first cavity to be displaced with inert gas to a target pressure, and then allowing the inert gas to stand; S2.2: Connect the vacuum pump to the second cavity to be replaced and evacuate to the target pressure; S2.3: Adjust the volume of the intermediate gas reservoir, connect the first cavity to be replaced with the intermediate gas reservoir, and fill the inert gas in the cavity into the intermediate gas reservoir; S2.4: Connect the intermediate gas reservoir and the second cavity to be replaced, fill the gas in the intermediate gas reservoir into the second cavity to be replaced, and then let it stand.

10. The time-series controlled multi-channel parallel gas replacement method according to claim 8, characterized in that: The step S1 specifically includes: connecting the vacuum pump with the first cavity to be replaced, and evacuating the cavity to the target pressure; the step S3 specifically includes: connecting the vacuum pump with the second cavity to be replaced, and evacuating the cavity to the target pressure, and detecting the gas purity by a mass spectrometer to determine whether the gas purity meets the standard. If not, proceed to step S4; if so, the replacement is completed.

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