A microwave plasma source multi-mode gas switching device and method

Abstract

The present invention relates to the field of microwave plasma source switching technology, and in particular to a microwave plasma source multi-mode gas switching device and method. A microwave plasma source multi-mode gas switching device includes a gas control device, which includes at least two gas paths and a control detection device; each gas path includes an air inlet and an air outlet, and a pulse valve and a switch valve are sequentially connected between the air inlet and the air outlet; the control detection device includes a control PCB, which is respectively connected to a plurality of pulse valves and a plurality of switch valves; and each two gas paths can be connected through a connecting channel. The present invention realizes the proportional mixing of two or more gases, rapid switching of airflows, and stable flow regulation through a combination of pulse valves and switch valves, and the present invention has the characteristics of multiple mixing modes, fast gas control response, high module integration, convenient expansion, and high stability in terms of gas mixing control.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave plasma source switching, and in particular to a microwave plasma source multi-mode gas switching device and method. Background Art

[0002] Microwave plasma is a quasi-equilibrium plasma characterized by high electron density and high electron temperature in an electrodeless discharge. A microwave plasma source uses microwaves to achieve stable gas excitation and plasma maintenance. In recent years, it has found widespread application in chemical vapor deposition, material surface modification, microcircuit manufacturing, plasma spraying, plasma chemical engineering, sample excitation for testing instruments, and environmental water treatment. Compared to existing ICP plasma sources, microwave plasma sources can operate in a variety of gas modes, including Ar, N2, and He, and feature high maintenance frequencies and excellent plasma stability.

[0003] During the operation of a microwave plasma source, the control of the working gas plays an important role in maintaining the stability of the plasma. Existing mass flow meters used for gas mixing and switching control often have a response time of seconds during gas switching control, which increases the instability of the plasma during source gas switching. The present invention, which uses a proportional valve, suffers from the disadvantage of uneven gas mixing during gas switching. This approach is not suitable for applications requiring high gas control precision, such as when used as a sample excitation source for a detection instrument. This can lead to unstable plasma flames, and the plasma source can easily extinguish and burn out the torch.

[0004] Compared to the prior art (CN114334596A) similar to the present invention, although both are microwave plasma control technologies, the microwave plasma of the present invention is primarily used as an excitation source for high-end precision instruments. It uses inert gases such as N2, Ar, and He as working gases and requires high power operation (typically around 1000W). Its operation places high demands on plasma stability and requires high precision in gas flow control. The microwave plasma control system proposed in the prior art is used for vapor deposition and etching. It uses H2, O2, and CH4 as working gases and operates at relatively low power (500W). Furthermore, the present invention uses a conventional multi-channel gas flow controller for gas flow control, which suffers from extended operation times and the inability to quickly and smoothly switch gas flows. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and provide a microwave plasma source multi-mode gas switching device and method.

[0006] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions:

[0007] A microwave plasma source multi-mode gas switching device includes a gas control device, the gas control device includes at least two gas paths and a control detection device;

[0008] Each of the gas circuits includes an air inlet and an air outlet, and at least two control valves are provided between the air inlet and the air outlet, and the at least two control valves are used to control the gas flow of the corresponding gas circuit and switch the air intake state of the corresponding gas circuit;

[0009] The gas control device further comprises a connecting gas circuit, the two ends of which are connected to the two gas circuits respectively;

[0010] The control detection device includes a control PCB, and the control PCB is connected to the plurality of control valves respectively.

[0011] As an improvement to the technical solution of the microwave plasma multi-mode gas switching device of the present invention, at least two of the control valves are a pulse valve and a switch valve respectively;

[0012] Each of the gas paths includes the gas inlet, the pulse valve, the switch valve and the gas outlet which are connected in sequence; or each of the gas paths includes the gas inlet, the switch valve, the pulse valve and the gas outlet which are connected in sequence.

[0013] As an improvement to the technical solution of the microwave plasma multi-mode gas switching device of the present invention, the microwave plasma source multi-mode gas switching device further comprises a gas valve base, wherein a plurality of first channels are formed in the gas valve base, and each first channel corresponds to one of the gas paths;

[0014] A connecting channel is also provided in the air valve base, and the connecting channel corresponds to the connecting air path.

[0015] As an improvement to the technical solution of the microwave plasma multi-mode gas switching device of the present invention, the control detection device also includes multiple air pressure sensors respectively connected to the control PCB, and multiple air pressure sensors are correspondingly arranged at the air outlet of each gas path; the air pressure sensor is used to collect the pressure value of the air outlet and feed the pressure value back to the MCU of the control PCB, and the MCU is used to control the inlet and outlet gas flow of the pulse valve.

[0016] As an improvement to the technical solution of the microwave plasma multi-mode gas switching device of the present invention, a set value is preset in the MCU. After receiving the pressure value fed back by the pressure sensor, the MCU compares the pressure value with the set value.

[0017] If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow;

[0018] If the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

[0019] As an improvement to the technical solution of the microwave plasma multi-mode gas switching device of the present invention, the gas path is used for gas to pass through, and the gas is any two or more gases of N2, Ar, and He.

[0020] A microwave plasma source multi-mode gas switching method, using the microwave plasma source multi-mode gas switching device as described above, includes the following steps:

[0021] Different gases are introduced into different gas circuits, and different working modes are switched by regulating the control valves in each gas circuit; by switching different working modes, gases or mixed gases are switched;

[0022] The gas output of the gas path is detected by the control detection device, and the duty cycle of the pulse valve in the control valve is reversely adjusted according to the gas output to adjust the gas output of different gas paths and / or the ratio of the mixed gas.

[0023] As an improvement to the technical solution of the microwave plasma source multi-mode gas switching method of the present invention, the gas output of each gas path detected by the pressure sensor is obtained by a detection device provided with an MCU, and a set value is preset in the MCU. After receiving the pressure value fed back by the pressure sensor, the MCU compares the pressure value with the set value;

[0024] If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow;

[0025] If the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

[0026] As an improvement to the technical solution of the microwave plasma source multi-mode gas switching method of the present invention, at least two of the control valves are a pulse valve and a switch valve respectively; each of the gas paths includes the gas inlet, the pulse valve, the switch valve and the gas outlet connected in sequence; or each of the gas paths includes the gas inlet, the switch valve, the pulse valve and the gas outlet connected in sequence;

[0027] By changing the connection mode of the corresponding pulse valve or switch valve outlet in each gas path through the connecting channel, the gas or mixed gas is switched under program control, and the gas output of each gas path detected by the air pressure sensor is obtained by a detection device provided with an MCU. The MCU is preset with a set value. After receiving the pressure value fed back by the air pressure sensor, the MCU compares the pressure value with the set value;

[0028] If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow;

[0029] If the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

[0030] Beneficial effects of the present invention:

[0031] 1. To address the shortcomings of existing microwave plasma source gas control, the present invention addresses the above issues by focusing on the switching, proportion mixing, and flow control of mixed gases, with low latency, through the combined control of multiple sets of solenoid valves and pulse valves. Through gas path connection, valve control, and pressure and airflow feedback, rapid switching of microwave plasma source airflow and stable operation in multiple gas modes are achieved;

[0032] 2. The present invention realizes the proportional mixing of two or more gases, rapid airflow switching and stable flow regulation by combining a pulse valve and an on-off valve. In terms of gas mixing control, the present invention has the characteristics of multiple mixing modes, fast gas control response, high module integration, convenient expansion and high stability.

[0033] 3. By changing the control timing of the corresponding pulse valve and switch valve in each gas path through the connecting channel, the gas or mixed gas is switched, and the gas output of each gas path detected by the pressure sensor is obtained by a detection device equipped with an MCU. A set value is preset in the MCU. After the MCU receives the pressure value fed back by the pressure sensor, it compares the pressure value with the set value. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the connection structure of the present invention;

[0035] Figure 2 Schematic diagram of the first gas control mode of the present invention;

[0036] Figure 3 Schematic diagram of the second gas control mode of the present invention;

[0037] Figure 4 Schematic diagram of the third gas control mode of the present invention;

[0038] Figure 5 Schematic diagram of the fourth gas control mode of the present invention;

[0039] Figure 6 Schematic diagram of the fifth gas control mode in the present invention.

[0040] Explanation of the accompanying drawings: 11 - first air inlet; 12 - first pulse valve; 13 - first switch valve; 14 - first air pressure sensor; 15 - first air outlet; 21 - second air inlet; 22 - second pulse valve; 23 - second switch valve; 24 - second air pressure sensor; 25 - second air outlet; 31 - third air inlet; 32 - third pulse valve; 33 - third switch valve; 34 - third air pressure sensor; 35 - third air outlet; 4 - air valve base; 5 - control PCB; 1 - first mixed gas; 2 - second mixed gas; 3 - third mixed gas; A - first gas path airflow; B - second gas path airflow; C - third gas path airflow. DETAILED DESCRIPTION

[0041] In order to make the purpose of the invention, technical solutions and beneficial effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0042] like Figure 1 As shown, a microwave plasma source multi-mode gas switching device includes a gas control device, the gas control device includes at least two gas paths and a control detection device;

[0043] Each gas circuit includes an air inlet and an air outlet, and at least two control valves are provided between the air inlet and the air outlet, and the at least two control valves are used to control the gas flow of the corresponding gas circuit and switch the air intake state of the corresponding gas circuit;

[0044] The gas control device further includes a connecting gas circuit, the two ends of which are connected to the two gas circuits respectively; the control and detection device includes a control PCB5, which is connected to the multiple control valves respectively.

[0045] In the present invention, two gas paths are taken as an example for explanation, and the two gas paths are respectively the first gas path and the second gas path; gas can be injected into the two gas paths respectively, and by controlling the control valve, the gas flow of the gas path can be adjusted and the gas intake state of the corresponding gas path can be switched, thereby realizing rapid switching of the microwave plasma source gas flow and stable operation under multiple gas modes.

[0046] In detail, the present invention includes at least two gas paths, which can achieve the effect of injecting gas into any gas path, and can achieve the effect of injecting the same gas or different gases into the two gas paths.

[0047] When gas is injected into any of the two gas paths, the gas can pass through the gas inlet, control valve and gas outlet in sequence to achieve the effect of gas flow. Under the action of the control detection device, the gas output at the gas outlet can be detected, and then the opening or closing of the control valve can be reversely adjusted according to the gas output volume to achieve the effect of adjusting the gas flow of the gas path.

[0048] When the same gas is injected into the two gas paths, the gas in the two gas paths can pass through the gas inlet, the control valve and the gas outlet in sequence to achieve the effect of gas flow. Under the action of the control detection device, the gas output at the gas outlet can be detected, and then the opening or closing of the control valve can be reversely adjusted according to the gas output volume to achieve the effect of adjusting the gas flow of the gas path;

[0049] When different gases are injected into the two gas paths, the gas mixing effect can be achieved by controlling the gas intake state of the gas path through the control valve, and the gas flow rate of the gas path can be controlled to achieve the effect of controlling the gas flow rate.

[0050] In some embodiments of the present invention, the gas path is used for gas to pass through, and the gas is any two or more gases of N2, Ar, and He.

[0051] In some embodiments of the present invention, the at least two control valves are a pulse valve and a switch valve;

[0052] Each gas path includes an air inlet, a pulse valve, an on / off valve, and an air outlet, all connected in sequence. Alternatively, each gas path includes an air inlet, an on / off valve, a pulse valve, and an air outlet, all connected in sequence. The pulse valve is used to adjust the amount of air in and out, and the on / off valve is used to switch the air flow in the channel between open and closed states.

[0053] In some embodiments of the present invention, the microwave plasma source multi-mode gas switching device also includes a gas valve base 4, in which a plurality of first channels are provided, and each first channel corresponds to a gas path; the gas valve base 4 also includes a connecting channel, and the connecting channel corresponds to the connecting gas path.

[0054] By connecting the channels to change the control timing of the corresponding pulse valves and switch valves in each gas path, the gas or mixed gas is switched, and the gas output of each gas path detected by the pressure sensor is obtained through a detection device equipped with an MCU. A set value is preset in the MCU. After the MCU receives the pressure value fed back by the pressure sensor, it compares the pressure value with the set value.

[0055] In some embodiments of the present invention, the control and detection device also includes multiple air pressure sensors respectively connected to the control PCB5, and the multiple air pressure sensors are correspondingly arranged at the air outlet of each air path; the air pressure sensor is used to collect the pressure value of the air outlet and feed the pressure value back to the MCU of the control PCB5, and the MCU is used to control the inlet and outlet air flow of the pulse valve.

[0056] Furthermore, a set value is preset in the MCU. After receiving the pressure value fed back by the pressure sensor, the MCU compares the pressure value with the set value;

[0057] If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow; if the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

[0058] In some embodiments of the present invention, the microwave plasma source multi-mode gas switching device includes at least two gas paths, and the at least two gas paths include a first gas path and a second gas path;

[0059] The first gas path includes a first air inlet 11, a first pulse valve 12, a first switch valve 13 and a first air outlet 15; the second gas path includes a second air inlet 21, a second pulse valve 22, a second switch valve 23 and a second air outlet 25; the first air inlet 11 is connected to the inlet of the first pulse valve 12 and the second switch valve 23 respectively;

[0060] The gas in the second gas path flows through the second gas inlet 21 and the second pulse valve 22 and is mixed with the gas in the first gas path to form a mixed gas, which is then discharged from the second gas outlet 25 .

[0061] In some embodiments of the present invention, the connecting channel connects the pulse valve outlet and the inlet of the switch valve in another gas circuit.

[0062] In the present invention, an example is given in which three gas paths are provided, wherein the three gases are nitrogen, argon and helium, and the switching and mixing of three plasmas are described as an example.

[0063] The air valve base 4 is used to set up multiple air channels to form multiple air paths. The air valve base 4 has a certain thickness and can be a air valve base 4 made of metal or plastic. Among them, based on the characteristics of metal, the preferred metal material is aluminum or stainless steel.

[0064] Taking an air path as an example, the air inlet and air outlet of the air path are respectively provided at the opposite ends of the air valve base 4, and a pulse valve and a switch valve are successively provided between the air inlet and the air outlet. The pulse valve is used to adjust the inlet and outlet air volume, and the switch valve is used to switch the flow and closing state of the gas in the channel.

[0065] The three air paths are the first air path, the second air path and the third air path. The first air path includes a first air inlet 11, a first pulse valve 12, a first switch valve 13, a first air outlet 15 and a first air pressure sensor 14. The second air path includes a second air inlet 21, a second pulse valve 22, a second switch valve 23, a second air outlet 25 and a second air pressure sensor 24. The third air path includes a third air inlet 31, a third pulse valve 32, a third switch valve 33, a third air outlet 35 and a third air pressure sensor 34.

[0066] The present invention can realize multiple modes of switching, mixing gas and airflow ratio mixing.

[0067] When the present invention is switching or mixing gases, the outlet of the multi-path pulse valve and the inlet of the switch valve are interconnected. The incoming gases from each path are mixed after passing through the pulse valve. When a switch valve on a path is opened, mixed gases of varying proportions are discharged through the outlet. During this process, by adjusting the duty cycle of each gas path pulse valve, the proportion of each gas flow can be adjusted, achieving the ratio adjustment of each component during the gas flow control process and achieving smooth switching of gas types.

[0068] In detail, in the switching and mixed gas modes, the outlet of the first pulse valve 12, the outlet of the second pulse valve 22 and the outlet of the third pulse valve 32 in the present invention are respectively connected to the inlet of the first switch valve 13, the inlet of the second switch valve 23 and the inlet of the third switch valve 33.

[0069] The first gas path airflow A, the second gas path airflow B, and the third gas path airflow C are mixed with each other after passing through the first pulse valve 12, the second pulse valve 22, and the third pulse valve 32. When one or more of the first switch valve 13, the second switch valve 23, and the third switch valve 33 are opened, the mixed gases in different proportions are discharged through the outlet.

[0070] During this process, the first air pressure sensor 14 , the second air pressure sensor 24 , and the third air pressure sensor 34 respectively collect the outlet air flow pressure values ​​of the first air outlet 15 , the second air outlet 25 , and the third air outlet 35 , and feed them back to the MCU of the control PCB5 board.

[0071] According to the proportional relationship between the outlet pressure value and the air flow rate, the MCU compares the outlet pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the gas circuit pulse valve to reduce the outlet air flow rate. If the pressure value is lower than the set value, the MCU increases the duty cycle of the gas circuit pulse valve to increase the outlet air flow rate.

[0072] By adjusting the duty cycle of each gas pulse valve, the proportion of each airflow can be adjusted, achieving proportional adjustment of each component during the airflow control process and smooth switching of gas types. In this mode, the present invention can achieve proportional adjustment and smooth switching of airflows in any two of the three air intakes, and arbitrary proportional adjustment of the three air intakes. At the same time, the total flow rate of the mixed gas can be controlled by combining three outlets with different flow rates.

[0073] The proportional mixing process of the airflows is as follows: In addition to being connected to the first pulse valve 12, the first air inlet 11 of the present invention is also connected to the inlet of the second on-off valve 23. During this mixing process, the second airflow B passes through the second air inlet 21 and the second pulse valve 22 and mixes with the first airflow A. When the second on-off valve is opened, the mixed airflow is discharged through the second air outlet 25. During this process, the proportional mixing of the first airflow A and the second airflow B is achieved by adjusting the duty cycle of the second pulse valve 22. Similar connection and control methods can be used to achieve proportional mixing of the two airflows.

[0074] In detail, when the present invention is in the air flow ratio mixing mode, the first air inlet 11 is connected to the inlet of the first pulse valve 12 and the second switch valve 23 respectively, wherein the first air inlet 11 is connected to the inlet of the second switch valve 23 through a connecting channel.

[0075] During the mixing process, the second gas path airflow B passes through the second air inlet 21 and the second pulse valve 22 and is mixed with the first gas path airflow A. When the second gas path switch valve is opened, the mixed gas flow is discharged through the second gas outlet 25.

[0076] During this process, the second air pressure sensor 24 at the second air outlet 25 of the airflow collects the outlet pressure value and feeds it back to the MCU of the control PCB 5. Since the outlet pressure value is directly proportional to the airflow volume, the MCU compares the outlet pressure value with a set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the second pulse valve 22 to reduce the flow rate at the second air outlet 25. If the pressure value is lower than the set value, the MCU increases the duty cycle of the second pulse valve 22 to increase the flow rate at the second air outlet 25.

[0077] By reversely adjusting the duty cycle of the second pulse valve 22, stable control of the valve airflow is achieved, and proportional mixing of the first airflow A and the second airflow B is achieved. Similar connection and control methods can be used to achieve proportional mixing of the second airflow B and the third airflow C, as well as the first airflow A and the third airflow C.

[0078] The present invention separately collects multi-channel air pressure / airflow data, adjusts different valve actions in real time according to the airflow data, and realizes rapid and stable multi-channel airflow switching process through closed-loop feedback control. It not only solves the problem of rapid control of working airflow, but also solves the problem of overshoot or too small airflow in the gas switching process. At the same time, the present invention also has good adaptability to fluctuations in external gas pressure / flow.

[0079] Compared with existing technical methods, the present invention and method adopted by the present invention can realize simultaneous control of multiple gases, the device is small in size, and the gas path connection is convenient and flexible; the present invention has multiple working modes and the gas path is easy to expand.

[0080] When switching airflows, both the pulse valve and solenoid valve have a response time of milliseconds, compared to existing gas flow controllers that have a response time of seconds, enabling rapid switching between multiple gases. Furthermore, when controlling gas mixing, the pulse valve employed in this invention operates at a high frequency, enabling uniform mixing of multiple airflows. Pulse-width modulation allows for stable gas mixing and flow regulation.

[0081] As a first embodiment of the present invention, Figure 1 As shown, each gas path includes an air inlet, a pulse valve, a switch valve and an air outlet that are connected in sequence.

[0082] The present invention includes a first air inlet 11, a first pulse valve 12, a first on-off valve 13, a first air pressure sensor 14, a first air outlet 15, a second air inlet 21, a second pulse valve 22, a second on-off valve 23, a second air pressure sensor 24, a second air outlet 25, a third air inlet 31, a third pulse valve 32, a third on-off valve 33, a third air pressure sensor 34, a third air outlet 35, an air valve base 4, and a control PCB 5. Connecting channels connect the air outlets of the first pulse valve 12, the second pulse valve 22, and the third pulse valve 32, and the air inlets of the first on-off valve 13, the second on-off valve 23, and the third on-off valve 33.

[0083] When the present invention works in gas switching mode, its gas circuit connection is as follows Figure 2 As shown, the outlets of the first pulse valve 12, the second pulse valve 22, and the third pulse valve 32 of the present invention are interconnected with the inlets of the first on-off valve 13, the second on-off valve 23, and the third on-off valve 33. The first gas flow A, the second gas flow B, and the third gas flow C are mixed after passing through the first pulse valve 12, the second pulse valve 22, and the third pulse valve 32. When one or more of the first on-off valve 13, the second on-off valve 23, and the third on-off valve 33 are opened, the mixed gases of varying proportions are discharged through the outlets.

[0084] During this process, the first air pressure sensor 14 , the second air pressure sensor 24 , and the third air pressure sensor 34 respectively collect the outlet air flow pressure values ​​of the first air outlet 15 , the second air outlet 25 , and the third air outlet 35 , and feed them back to the MCU of the control PCB5 board.

[0085] According to the proportional relationship between the outlet pressure value and the air flow rate, the MCU compares the outlet pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the gas circuit pulse valve to reduce the outlet air flow rate. If the pressure value is lower than the set value, the MCU increases the duty cycle of the gas circuit pulse valve to increase the outlet air flow rate.

[0086] By adjusting the duty cycle of each gas pulse valve, the proportion of each gas flow can be adjusted, achieving proportional adjustment of each component during the airflow control process and achieving smooth switching of gas types. In this mode, the pulse solenoid valve operates at a frequency of 5kHz, and the duty cycle can be adjusted within a range of 0-100% according to the airflow ratio.

[0087] This embodiment can realize the proportional adjustment and smooth switching of the airflows of any two of the three air intakes, namely the first airflow A, the second airflow B, and the third airflow C, and the arbitrary proportional adjustment of the three air intakes. At the same time, the total flow rate of the mixed gas can be controlled by combining the three air outlets with different flow rates.

[0088] The above-mentioned gas flows A, B, and C are N2, Ar, and He respectively.

[0089] As a second embodiment of the present invention, Figure 3 As shown, each gas path includes an air inlet, a pulse valve, a switch valve and an air outlet that are connected in sequence.

[0090] The present invention includes a first air inlet 11, a first pulse valve 12, a first switch valve 13, a first air pressure sensor 14, a first air outlet 15, a second air inlet 21, a second pulse valve 22, a second switch valve 23, a second air pressure sensor 24, a second air outlet 25, a third air inlet 31, a third pulse valve 32, a third switch valve 33, a third air pressure sensor 34, a third air outlet 35, an air valve base 4, and a control PCB 5.

[0091] When the present invention works in the air flow ratio mixing mode, its air path connection is as follows Figure 3As shown, in addition to being connected to the first pulse valve 12, the first air inlet 11 is also connected to the inlet of the second on-off valve 23. That is, in this embodiment, the first air inlet 11 is connected to the inlet of the first pulse valve 12, and the first air inlet 11 is connected to the inlet of the second on-off valve 23 via a connecting channel; the second air inlet 21 is connected to the inlet of the second pulse valve 22, and the second air inlet 21 is connected to the inlet of the third on-off valve 33 via a connecting channel; the third air inlet 31 is connected to the inlet of the third pulse valve 32, and the third air inlet 31 is connected to the inlet of the first on-off valve 13 via a connecting channel.

[0092] During the mixing process, the second air path airflow B passes through the second air inlet 21 and the second pulse valve 22 and is mixed with the first air path airflow A. When the second switch valve 23 is opened, the mixed airflow is discharged through the second air outlet 25. During this process, the second air pressure sensor 24 at the second air outlet 25 end of the airflow collects the outlet pressure value and feeds it back to the MCU of the control PCB5.

[0093] According to the proportional relationship between the outlet pressure value and the air flow rate, the MCU compares the outlet pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the second pulse valve 22 to reduce the flow rate of the second air outlet 25. If the pressure value is lower than the set value, the MCU increases the duty cycle of the second pulse valve 22 to increase the flow rate of the second air outlet 25.

[0094] By reversely adjusting the duty cycle of the second pulse valve 22, stable control of the valve airflow is achieved, achieving proportional mixing of the first airflow A and the second airflow B. In this mode, the pulse solenoid valve operates at a frequency of 10 kHz, and the duty cycle can be adjusted within a range of 0-100% based on the airflow ratio. Through similar connection and control methods, this embodiment can achieve proportional mixing of the second airflow B and the third airflow C, and the first airflow A and the third airflow C.

[0095] The above-mentioned gas flows A, B, and C are N2, Ar, and He respectively.

[0096] As a third embodiment of the present invention, Figure 4 As shown, each gas path includes an air inlet, a switch valve, a pulse valve and an air outlet that are connected in sequence.

[0097] The present invention includes a first air inlet 11, a first switch valve 13, a first pulse valve 12, a first air pressure sensor 14, a first air outlet 15, a second air inlet 21, a second switch valve 23, a second pulse valve 22, a second air pressure sensor 24, a second air outlet 25, a third air inlet 31, a third switch valve 33, a third pulse valve 32, a third air pressure sensor 34, a third air outlet 35, an air valve base 4, and a control PCB 5.

[0098] When the present invention works in the air flow ratio mixing mode, its air path connection is as follows Figure 4 As shown, in addition to being connected to the first on-off valve 13, the first air inlet 11 is also connected to the inlet of the second pulse valve 22. That is, in this embodiment, the first air inlet 11 is connected to the inlet of the first on-off valve 13, and the first air inlet 11 is connected to the inlet of the second pulse valve 22 through a connecting channel; the second air inlet 21 is connected to the inlet of the second on-off valve 23, and the second air inlet 21 is connected to the inlet of the third pulse valve 32 through a connecting channel; the third air inlet 31 is connected to the inlet of the third on-off valve 33, and the third air inlet 31 is connected to the inlet of the first pulse valve 12 through a connecting channel.

[0099] During the mixing process, the second air flow B passes through the second air inlet 21 and the second switch valve 23 and is mixed with the first air flow A. When the second pulse valve 22 is opened, the mixed air flow is discharged through the second air outlet 25.

[0100] During this process, the second air pressure sensor 24 at the second air outlet 25 of the air flow collects the outlet pressure value and feeds it back to the MCU of the control PCB 5 .

[0101] According to the proportional relationship between the outlet pressure value and the air flow rate, the MCU compares the outlet pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the second pulse valve 22 to reduce the flow rate of the second air outlet 25. If the pressure value is lower than the set value, the MCU increases the duty cycle of the second pulse valve 22 to increase the flow rate of the second air outlet 25.

[0102] By reversely adjusting the duty cycle of the second pulse valve 22, stable control of the mixed airflow of the first and second airflows A and B is achieved. Simultaneously, during the airflow control process, the second on / off valve 23 can be used to switch the A / B mixed airflow to a single airflow A. In this mode, the pulse solenoid valve operates at a frequency of 12 kHz, and the duty cycle is adjustable within a range of 0-100% based on the airflow ratio. Through similar connection and control methods, this embodiment can achieve flow regulation and switching between the mixed airflows of the second and third airflows B and C, and the first and third airflows A and C.

[0103] The above-mentioned gas flows A, B, and C are N2, Ar, and He respectively.

[0104] As a fourth embodiment of the present invention, Figure 5 As shown, each gas path includes an air inlet, a switch valve, a pulse valve and an air outlet that are connected in sequence.

[0105] The present invention includes a first air inlet 11, a first switch valve 13, a first pulse valve 12, a first air pressure sensor 14, a first air outlet 15, a second air inlet 21, a second switch valve 23, a second pulse valve 22, a second air pressure sensor 24, a second air outlet 25, a third air inlet 31, a third switch valve 33, a third pulse valve 32, a third air pressure sensor 34, a third air outlet 35, an air valve base 4, and a control PCB 5.

[0106] When the present invention works in the air flow ratio mixing mode, its air path connection is as follows Figure 5 As shown, the outlet of the first switch valve 13 is not only connected to the inlet of the first pulse valve 12, but also connected to the second air outlet 25. That is, in this embodiment, the first air inlet 11 is connected to the first switch valve 13, the outlet of the first switch valve 13 is connected to the inlet of the first pulse valve 12, and the outlet of the first switch valve 13 is connected to the outlet of the second pulse valve 22 through a connecting channel; the second air inlet 21 is connected to the second switch valve 23, the outlet of the second switch valve 23 is connected to the inlet of the second pulse valve 22, and the outlet of the second switch valve 23 is connected to the outlet of the third pulse valve 32 through a connecting channel; the third air inlet 31 is connected to the third switch valve 33, the outlet of the third switch valve 33 is connected to the inlet of the third pulse valve 32, and the outlet of the third switch valve 33 is connected to the outlet of the first pulse valve 12 through a connecting channel.

[0107] During the mixing process, the second air path airflow B passes through the second air inlet 21, the second switch valve 23, and the second pulse valve 22 and is mixed with the first air path airflow A that passes through the first switch valve 13. The mixed airflow is discharged through the second air outlet 25. During this process, the second air pressure sensor 24 at the second air outlet 25 end of the airflow collects the outlet pressure value and feeds it back to the MCU of the control PCB5.

[0108] According to the proportional relationship between the outlet pressure value and the air flow rate, the MCU compares the outlet pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the second pulse valve 22 to reduce the flow rate of the second air outlet 25. If the pressure value is lower than the set value, the MCU increases the duty cycle of the second pulse valve 22 to increase the flow rate of the second air outlet 25.

[0109] By reversely adjusting the duty cycle of the second pulse valve 22, stable control of the mixed airflow of the first and second airflows A and B is achieved. Simultaneously, during the airflow control process, the second on / off valve 23 can be used to switch the A / B mixed airflow to a single airflow A. In this mode, the pulse solenoid valve operates at a frequency of 12 kHz, and the duty cycle is adjustable within a range of 0-100% based on the airflow ratio. Through similar connection and control methods, this embodiment can achieve flow regulation and switching between the mixed airflows of the second and third airflows B and C, and the first and third airflows A and C.

[0110] The above-mentioned gas flows A, B, and C are N2, Ar, and He respectively.

[0111] As a fifth embodiment of the present invention, Figure 6 As shown, each gas path includes an air inlet, a pulse valve, a switch valve and an air outlet which are connected in sequence.

[0112] The present invention includes a first air inlet 11, a first switch valve 13, a first pulse valve 12, a first air pressure sensor 14, a first air outlet 15, a second air inlet 21, a second switch valve 23, a second pulse valve 22, a second air pressure sensor 24, a second air outlet 25, a third air inlet 31, a third switch valve 33, a third pulse valve 32, a third air pressure sensor 34, a third air outlet 35, an air valve base 4, and a control PCB 5.

[0113] When the present invention works in the air flow ratio mixing mode, its air path connection is as follows Figure 6 As shown, the outlet of the first pulse valve 12 is connected to the first on-off valve 13 and is also connected to the second air outlet 25. That is, in this embodiment, the first air inlet 11 is connected to the first pulse valve 12, the outlet of the first pulse valve 12 is connected to the inlet of the first on-off valve 13, and the outlet of the first pulse valve 12 is connected to the outlet of the second on-off valve 23 through a connecting channel; the second air inlet 21 is connected to the second pulse valve 22, the outlet of the second pulse valve 22 is connected to the inlet of the second on-off valve 23, and the outlet of the second pulse valve 22 is connected to the outlet of the third on-off valve 33 through a connecting channel; the third air inlet 31 is connected to the third pulse valve 32, the outlet of the third pulse valve 32 is connected to the inlet of the third on-off valve 33, and the outlet of the third pulse valve 32 is connected to the outlet of the first on-off valve 13 through a connecting channel.

[0114] During the mixing process, the second air path airflow B passes through the second air inlet 21, the second pulse valve 22, and the second switch valve 23 and is mixed with the first air path airflow A passing through the outlet of the first pulse valve 12. The mixed airflow is discharged through the second air outlet 25. During this process, the second air pressure sensor 24 at the second air outlet 25 end of the airflow collects the outlet pressure value and feeds it back to the MCU of the control PCB5.

[0115] According to the proportional relationship between the outlet pressure value and the air flow rate, the MCU compares the outlet pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the first pulse valve 12 and the second pulse valve 22 to reduce the flow rate of the second air outlet 25. If the pressure value is lower than the set value, the MCU increases the duty cycle of the first pulse valve 12 and the second pulse valve 22 to increase the flow rate of the second air outlet 25.

[0116] By adjusting the duty cycle of the first pulse valve 12 and the second pulse valve 22, the proportion of each airflow can be adjusted, achieving proportional adjustment of the mixing of the first airflow A and the second airflow B, and achieving smooth switching and stable control of gas types. Through similar connection and control methods, this embodiment can achieve proportional mixing of the second airflow B and the third airflow C, and the first airflow A and the third airflow C. In this mode, the pulse solenoid valve operates at a frequency of 10 kHz, and the duty cycle can be adjusted within the range of 0-100% according to the airflow ratio. The present invention can achieve proportional adjustment and smooth switching of the airflows of any two of the three air intakes.

[0117] The above-mentioned gas flows A, B, and C are N2, Ar, and He respectively.

[0118] The present invention also provides a microwave plasma source multi-mode gas switching method, using the microwave plasma source multi-mode gas switching device as described above, comprising the following steps:

[0119] Different gases are introduced into different gas circuits, and different working modes are switched by regulating the control valves in each gas circuit; by switching different working modes, gases or mixed gases are switched;

[0120] The gas output of the gas path is detected by the control detection device, and the duty cycle of the control valve is reversely adjusted according to the gas output to adjust the gas output of different gas paths and / or the ratio of the mixed gas.

[0121] In some embodiments of the present invention, the gas output of each gas path detected by the air pressure sensor is obtained by a detection device provided with an MCU. A set value is preset in the MCU. After receiving the pressure value fed back by the air pressure sensor, the MCU compares the pressure value with the set value.

[0122] If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow; if the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

[0123] In some embodiments of the present invention, at least two control valves are a pulse valve and a switch valve; each gas path includes an air inlet, a pulse valve, a switch valve, and an air outlet connected in sequence; or, each gas path includes an air inlet, a switch valve, a pulse valve, and an air outlet connected in sequence;

[0124] By changing the connection mode of the corresponding pulse valve or switch valve outlet in each gas path through the connecting channel, the gas or mixed gas is switched under program control, and the gas output of each gas path detected by the pressure sensor is obtained through the detection device equipped with MCU. The MCU is preset with a set value. After receiving the pressure value fed back by the pressure sensor, the MCU compares the pressure value with the set value.

[0125] If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow; if the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

[0126] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A microwave plasma source multi-mode gas switching device, characterized in that: A gas control device is included, and the gas control device includes at least two gas paths and a control detection device; Each of the gas circuits includes an air inlet and an air outlet, and at least two control valves are provided between the air inlet and the air outlet, and the at least two control valves are used to control the gas flow of the corresponding gas circuit and switch the air intake state of the corresponding gas circuit; The gas control device further comprises a connecting gas circuit, the two ends of which are connected to the two gas circuits respectively; The control detection device includes a control PCB, and the control PCB is connected to the plurality of control valves respectively; at least two of the control valves are a pulse valve and a switch valve respectively; Each of the gas paths includes the gas inlet, the pulse valve, the switch valve and the gas outlet which are connected in sequence; or each of the gas paths includes the gas inlet, the switch valve, the pulse valve and the gas outlet which are connected in sequence.

2. The microwave plasma source multi-mode gas switching device according to claim 1, characterized in that: The microwave plasma source multi-mode gas switching device further comprises a gas valve base, wherein a plurality of first channels are formed in the gas valve base, and each first channel corresponds to one of the gas paths; A connecting channel is also provided in the air valve base, and the connecting channel corresponds to the connecting air path.

3. The microwave plasma source multi-mode gas switching device according to claim 1, characterized in that: The control detection device also includes multiple air pressure sensors respectively connected to the control PCB, and the multiple air pressure sensors are correspondingly arranged at the air outlet of each air path; the air pressure sensor is used to collect the pressure value of the air outlet and feed the pressure value back to the MCU of the control PCB, and the MCU is used to control the inlet and outlet air flow of the pulse valve.

4. The microwave plasma source multi-mode gas switching device according to claim 3, characterized in that: The MCU is preset with a set value. After receiving the pressure value fed back by the air pressure sensor, the MCU compares the pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow; If the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

5. The microwave plasma source multi-mode gas switching device according to claim 1, characterized in that: The gas path is used for gas to pass through, and the gas is any two or more gases of N2, Ar, and He.

6. A microwave plasma source multi-mode gas switching method, characterized in that: Using the microwave plasma source multi-mode gas switching device according to any one of claims 1 to 5 comprises the following steps: Different gases are introduced into different gas circuits, and different working modes are switched by regulating the control valves in each gas circuit; by switching different working modes, gases or mixed gases are switched; The gas output of the gas path is detected by the control detection device, and the duty cycle of the pulse valve in the control valve is reversely adjusted according to the gas output to adjust the gas output of different gas paths and / or the ratio of the mixed gas.

7. The microwave plasma source multi-mode gas switching method according to claim 6, characterized in that: The gas output of each gas path detected by the air pressure sensor is obtained by a detection device provided with an MCU. The MCU is preset with a set value. After receiving the pressure value fed back by the air pressure sensor, the MCU compares the pressure value with the set value. If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow; If the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

8. The microwave plasma source multi-mode gas switching method according to claim 6, characterized in that: At least two of the control valves are a pulse valve and a switch valve; each of the gas circuits includes the gas inlet, the pulse valve, the switch valve, and the gas outlet in sequence; or each of the gas circuits includes the gas inlet, the switch valve, the pulse valve, and the gas outlet in sequence; By changing the connection mode of the corresponding pulse valve or switch valve outlet in each gas path through the connecting channel, the gas or mixed gas is switched under program control, and the gas output of each gas path detected by the air pressure sensor is obtained by a detection device provided with an MCU. The MCU is preset with a set value. After receiving the pressure value fed back by the air pressure sensor, the MCU compares the pressure value with the set value; If the pressure value is higher than the set value, the MCU reduces the duty cycle of the pulse valve of the corresponding gas path to reduce the outlet gas flow; If the pressure value is lower than the set value, the MCU increases the duty cycle of the pulse valve of the corresponding gas path to increase the outlet gas flow.

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