Mixed gas supply system

Abstract

The application provides a mixed gas supply system, which comprises a first gas inlet pipeline, a second gas inlet pipeline, a mixing pipe, a buffer tank, a mixed gas supply pipeline, a first gas analyzer, a second gas analyzer and a control module; a first mass flow controller is arranged on the first gas inlet pipeline, a second mass flow controller is arranged on the second gas inlet pipeline, and the first gas analyzer, the second gas analyzer, the first mass flow controller and the second mass flow controller are all signal-connected with the control module. The mixed gas supply system can detect whether the parameters of the mixed gas meet the standards in time, and timely adjust the gas supply flow according to the current parameters of the mixed gas, so that the parameters of the mixed gas are kept in the set range and stable, thereby improving the reliability of the system and the stability of production.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing equipment technology, and in particular to a mixed gas supply system. Background Technology

[0002] In the semiconductor chip manufacturing process, mixed gases with different component ratios or concentrations are required depending on the specific processes and equipment needs. Examples include mixtures of PH3 and H2, B2H6 and H2, and H2 and N2. Furthermore, as the process changes, the corresponding component ratios or concentration parameters need to be adjusted in real time. When using these mixed gases, a high degree of stability in gas concentration is required.

[0003] Existing mixed gas supply systems typically use pre-mixed gas cylinders for supply (i.e., cylinders containing pre-mixed gases). While their structure is relatively simple, they cannot detect or adjust the gas mixing effect in a timely manner, relying solely on open-loop control to deliver a pre-defined, qualified mixed gas to the process equipment. If the mixed gas supply system is affected by external factors, causing the mixed gas parameters to deviate from the standard, this design cannot detect or correct the issue promptly, thus impacting product quality and yield. Furthermore, because the gas concentration in the cylinders depends on production requirements, the concentration is generally low. After each cylinder is used, the pipeline needs to be purged and replaced before a new cylinder can be used. As gas consumption increases, the frequency of cylinder replacements increases, further impacting production efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a mixed gas supply system that can detect in a timely manner whether the parameters of the mixed gas meet the standards, and adjust the gas supply flow rate in a timely manner according to the current parameters of the mixed gas, so that the parameters of the mixed gas are within the set range and remain stable, thereby improving the reliability of the system and the stability of production.

[0005] This invention provides a mixed gas supply system, including a first inlet pipe for conveying a first type of process gas, a second inlet pipe for conveying a second type of process gas, a mixing pipe, a buffer tank, a mixed gas supply pipe for connecting to a process machine, a first gas analyzer, a second gas analyzer, and a control module;

[0006] The first intake pipe and the second intake pipe are connected in parallel and then connected to the inlet of the mixing pipe. The outlet of the mixing pipe is connected to the inlet of the buffer tank through a mixed gas inlet pipe, and the outlet of the buffer tank is connected to the mixed gas supply pipe through a mixed gas outlet pipe. The first gas analyzer is connected to the mixed gas inlet pipe and is used to detect the composition ratio and / or concentration value of the mixed gas after preliminary mixing in the mixing pipe. The second gas analyzer is connected to the mixed gas outlet pipe and is used to detect the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank.

[0007] A first mass flow controller is provided on the first air intake pipe, and a second mass flow controller is provided on the second air intake pipe. The first gas analyzer, the second gas analyzer, the first mass flow controller, and the second mass flow controller are all signal-connected to the control module.

[0008] When the second gas analyzer detects that the composition ratio and / or concentration of the mixed gas after secondary mixing in the buffer tank is within the set range, the mixed gas in the buffer tank is transported to the mixed gas supply pipeline through the mixed gas outlet pipeline; when the second gas analyzer detects that the composition ratio and / or concentration of the mixed gas after secondary mixing in the buffer tank is not within the set range, the control module controls the first mass flow controller and / or the second mass flow controller to adjust their flow opening based on the difference between the composition ratio and / or concentration of the mixed gas detected by the second gas analyzer and the set value.

[0009] Furthermore, the mixed gas supply system also includes a venting module, which is connected to the mixed gas outlet pipeline; when the second gas analyzer detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank is not within the set range, the mixed gas in the buffer tank is discharged through the mixed gas outlet pipeline and the venting module.

[0010] Furthermore, the venting module includes a compressed gas pipeline, one end of which is provided with a compressed gas inlet and the other end of which is provided with a discharge port. A vacuum generator is provided on the compressed gas pipeline, and the mixed gas outlet pipeline is connected to the vacuum generator through a connecting pipeline. The vacuum generator is used to generate negative pressure to draw the gas in the mixed gas outlet pipeline into the vacuum generator and discharge it through the discharge port.

[0011] Furthermore, a first pressure gauge is provided on the outlet pipe of the mixed gas, and a first pneumatic diaphragm valve is provided on the connecting pipe. Both the first pressure gauge and the first pneumatic diaphragm valve are connected to the control module via signal. When the pressure value detected by the first pressure gauge does not change within a certain period of time, the control module controls the first pneumatic diaphragm valve to open automatically so as to discharge the mixed gas in the buffer tank through the discharge port.

[0012] Furthermore, the connecting pipeline is also equipped with a needle valve, a back pressure valve, and a second pressure gauge in sequence.

[0013] Furthermore, the mixed gas supply system also includes a nitrogen purging line and a bypass line. The nitrogen purging line is connected to the first intake line and the second intake line. One end of the bypass line is connected to the mixed gas outlet line, and the other end of the bypass line is connected to the connecting line.

[0014] Furthermore, a three-way valve is provided on the mixed gas inlet pipeline, the first port of the three-way valve is connected to the outlet of the mixing pipe, and the second port of the three-way valve is connected to the inlet of the buffer tank; the mixed gas supply system also includes a branch pipeline, one end of which is connected to the third port of the three-way valve, and the other end of which is connected to the connecting pipeline.

[0015] Furthermore, a gas concentration detector is provided on the first intake pipe and / or the second intake pipe. The gas concentration detector is signal-connected to the control module and is used to detect the gas concentration in the first intake pipe and / or the second intake pipe.

[0016] Furthermore, a first pressure regulating valve is provided on the first intake pipe, a second pressure regulating valve is provided on the second intake pipe, and a third pressure regulating valve is provided on the mixed gas outlet pipe.

[0017] Furthermore, the buffer tank has a gas inlet and a gas outlet at its bottom, and an inner tube inside the buffer tank. The inner tube extends from the bottom to the top of the buffer tank and is inclined inside the buffer tank. The bottom end of the inner tube is connected to the mixed gas inlet pipeline through the gas inlet, and the top outlet of the inner tube is located at the top of the buffer tank. The gas outlet of the buffer tank is connected to the mixed gas outlet pipeline.

[0018] The mixed gas supply system provided by this invention, by setting up a mixing pipe and a buffer tank, allows the gas to undergo preliminary mixing in the mixing pipe and the mixed gas inlet pipeline, followed by secondary mixing (deep mixing) in the buffer tank, thereby improving the mixing uniformity of various gases in the mixed gas. Simultaneously, by setting up a first gas analyzer, a second gas analyzer, a first mass flow controller, and a second mass flow controller, the system can promptly detect whether the parameters of the mixed gas meet the standards and adjust the gas supply flow rate accordingly, keeping the parameters of the mixed gas within the set range and maintaining stability, thereby improving the reliability of the system and the stability of production. Furthermore, this mixed gas supply system can dilute the gas, enabling the use of a high-concentration gas source (cylinder), thereby reducing the frequency of gas source (cylinder) replacement and improving production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the mixed gas supply system in an embodiment of the present invention.

[0020] Figure 2 for Figure 1 A schematic diagram of the internal structure of the buffer tank.

[0021] Figure 3 This is a schematic diagram of the control logic of the mixed gas supply system in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of a mixed gas supply system in another embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the control logic of a mixed gas supply system in another embodiment of the present invention. Detailed Implementation

[0024] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0025] The terms "first," "second," "third," "fourth," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0026] like Figures 1 to 3 As shown, the mixed gas supply system provided in this embodiment of the invention includes a first inlet pipe 11 for conveying a first type of process gas, a second inlet pipe 12 for conveying a second type of process gas, a mixing pipe 3, a buffer tank 4, a mixed gas supply pipe 15 for connecting to a process machine (not shown), a first gas analyzer 61, a second gas analyzer 62, and a control module 7.

[0027] The first intake pipe 11 and the second intake pipe 12 are connected in parallel and then connected to the inlet of the mixing pipe 3. The outlet of the mixing pipe 3 is connected to the inlet of the buffer tank 4 through the mixed gas inlet pipe 13. The outlet of the buffer tank 4 is connected to the mixed gas supply pipe 15 through the mixed gas outlet pipe 14. The first gas analyzer 61 is connected to the mixed gas inlet pipe 13 and is used to detect the composition ratio and / or concentration value of the mixed gas after preliminary mixing in the mixing pipe 3. The second gas analyzer 62 is connected to the mixed gas outlet pipe 14 and is used to detect the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank 4.

[0028] The first intake pipe 11 is equipped with a first mass flow controller 63, and the second intake pipe 12 is equipped with a second mass flow controller 64. The first gas analyzer 61, the second gas analyzer 62, the first mass flow controller 63 and the second mass flow controller 64 are all connected to the control module 7 via signal.

[0029] When the second gas analyzer 62 detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank 4 is within the set range, the mixed gas in the buffer tank 4 is transported to the mixed gas supply pipeline 15 through the mixed gas outlet pipeline 14; when the second gas analyzer 62 detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank 4 is not within the set value range, the control module 7 controls the first mass flow controller 63 and / or the second mass flow controller 64 to adjust their flow opening based on the difference between the composition ratio and / or concentration value of the mixed gas detected by the second gas analyzer 62 and the set value.

[0030] Specifically, the mixed gas supply system provided in this embodiment, by setting up a mixing pipe 3 and a buffer tank 4, allows the gas to undergo preliminary mixing in the mixing pipe 3 and the mixed gas inlet pipe 13, followed by secondary mixing (deep mixing) in the buffer tank 4, thereby improving the uniformity of the mixing of various gases in the mixed gas. Simultaneously, by setting up a first gas analyzer 61, a second gas analyzer 62, a first mass flow controller 63, and a second mass flow controller 64, the system can promptly detect whether the parameters of the mixed gas meet the standards and adjust the gas supply flow rate in a timely manner according to the current parameters, ensuring that the parameters of the mixed gas remain within the set range and stable, thereby improving the reliability of the system and the stability of production; moreover, it can flexibly adjust the gas supply parameters according to production needs, improving production efficiency.

[0031] Meanwhile, this mixed gas supply system can dilute the gas, allowing it to use a high-concentration gas source (cylinder), thereby reducing the frequency of gas source (cylinder) replacement and improving production efficiency. For example, taking the preparation of a 20ppm PH3 and H2 mixture as an example: the first inlet pipe 11 connects to a first cylinder (not shown) containing H2, and the second inlet pipe 12 connects to a second cylinder (not shown) containing PH3 / H2 (mixture). Since this mixed gas supply system mixes the H2 output from the first inlet pipe 11 with the PH3 / H2 output from the second inlet pipe 12, it dilutes the PH3. Therefore, the second cylinder can hold a higher concentration of PH3 / H2 (e.g., 1% PH3 / H2 mixture), while traditional finished mixed gas cylinders need to hold a low concentration of PH3 / H2 mixture, thus reducing the frequency of second cylinder replacement and improving production efficiency.

[0032] like Figure 1 As shown, in one embodiment, the mixed gas supply system also includes a venting module 9, which is connected to the mixed gas outlet pipeline 14. When the second gas analyzer 62 detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank 4 is not within the set range, the mixed gas in the buffer tank 4 is discharged through the mixed gas outlet pipeline 14 and the venting module 9.

[0033] Specifically, when the second gas analyzer 62 detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank 4 are not within the set range, it indicates that the gas parameters in the buffer tank 4 do not meet the production requirements of the downstream process equipment and need to be discharged. By discharging the unqualified gas to the venting module 9, the unqualified gas is prevented from flowing to the downstream process equipment and affecting product quality and yield.

[0034] like Figure 1 As shown, in one embodiment, the venting module 9 includes a compressed gas pipeline 92. One end of the compressed gas pipeline 92 is provided with a compressed gas inlet 921, and the other end is provided with a discharge port 922. A vacuum generator 93 is provided on the compressed gas pipeline 92. The mixed gas outlet pipeline 14 is connected to the vacuum generator 93 through a connecting pipeline 96. The vacuum generator 93 is used to generate negative pressure to draw the gas in the mixed gas outlet pipeline 14 into the vacuum generator 93 and discharge it through the discharge port 922. That is, when the second gas analyzer 62 detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank 4 is not within the set range, the mixed gas in the buffer tank 4 can be discharged sequentially through the mixed gas outlet pipeline 14, the connecting pipeline 96, the vacuum generator 93, and the compressed gas pipeline 92, and then through the discharge port 922.

[0035] Specifically, in this embodiment, the vacuum generator 93 utilizes the negative pressure generated when compressed gas passes through a narrow channel within the vacuum generator 93, thereby drawing gas and / or liquid from the connecting pipe 96 into the vacuum generator 93. During operation, the compressed gas inlet 921 of the compressed gas pipe 92 is connected to a compressed gas source. After the compressed gas (compressed nitrogen in this embodiment) enters the compressed gas pipe 92, the vacuum generator 93 draws in the gas from the connecting pipe 96, and then discharges it through the outlet 922, thereby improving working efficiency.

[0036] like Figure 1 and Figure 3 As shown, in one embodiment, a first pressure gauge 21 is provided on the mixed gas outlet pipeline 14, and a first pneumatic diaphragm valve 51 is provided on the connecting pipeline 96. Both the first pressure gauge 21 and the first pneumatic diaphragm valve 51 are signal-connected to the control module 7. When the pressure value detected by the first pressure gauge 21 does not change within a certain period of time, the control module 7 controls the first pneumatic diaphragm valve 51 to automatically open, so as to discharge the mixed gas in the buffer tank 4 through the discharge port 922.

[0037] Specifically, the mixed gas supply system has the function of automatically replacing the mixed gas in the buffer tank 4: the first pressure gauge 21 is used to detect the pressure in the mixed gas outlet pipe 14 (that is, the pressure of the mixed gas in the buffer tank 4); when the pressure value detected by the first pressure gauge 21 does not change within a period of time (e.g., one hour), it indicates that the machine is in a resting state. At this time, the control module 7 controls the first pneumatic diaphragm valve 51 to open automatically, so that the mixed gas in the buffer tank 4 passes through the mixed gas outlet pipe 14, the connecting pipe 96, the vacuum generator 93 and the compressed gas pipe 92 in sequence and is discharged through the discharge port 922. Then, new mixed gas is injected into the buffer tank 4 to complete the automatic replacement of the mixed gas in the buffer tank 4, thereby improving production efficiency.

[0038] like Figure 1 As shown, in one embodiment, the connecting pipe 96 is also sequentially equipped with a needle valve 58, a back pressure valve 52 (i.e., a pressure regulating valve), and a second pressure gauge 22. The needle valve 58 is used to regulate the flow rate of gas in the connecting pipe 96, and the back pressure valve 52 is used to regulate the pressure of gas in the connecting pipe 96, thereby making the system more stable during exhaust; the needle valve 58 and the back pressure valve 52 are generally in a normally open state. At the same time, when the pressure in the buffer tank 4 and the mixed gas outlet pipe 14 is too high, it can also be relieved through the venting module 9.

[0039] like Figure 1 As shown, in one embodiment, a second pneumatic diaphragm valve 510 is also provided on the connecting pipe 96.

[0040] like Figure 1As shown, in one embodiment, the mixed gas supply system also includes a vacuum pipeline 81. The vacuum pipeline 81 is under negative pressure and is connected to a connecting pipeline 96. A first manual diaphragm valve 53 is provided between the vacuum pipeline 81 and the connecting pipeline 96. When the equipment is being installed and debugged or after an abnormality occurs, the first manual diaphragm valve 53 can be opened to use the negative pressure in the vacuum pipeline 81 to evacuate the gas in each pipeline of the equipment, thereby ensuring the mixing accuracy.

[0041] like Figure 1 As shown, in one embodiment, a first pressure regulating valve 54 is provided on the first intake pipe 11, a second pressure regulating valve 55 is provided on the second intake pipe 12, and a third pressure regulating valve 56 is provided on the mixed gas outlet pipe 14. The first pressure regulating valve 54 is used to regulate the gas intake pressure in the first intake pipe 11, the second pressure regulating valve 55 is used to regulate the gas intake pressure in the second intake pipe 12, and the third pressure regulating valve 56 is used to regulate the mixed gas output pressure in the mixed gas outlet pipe 14.

[0042] like Figure 1 As shown, in one embodiment, a first pressure gauge 23 is installed on the pipeline before and after the first pressure regulating valve 54, and a third pressure gauge 25 is installed on the pipeline after the first pressure regulating valve 54. A second pressure gauge 24 is installed on the pipeline before and after the second pressure regulating valve 55, and a fourth pressure gauge 26 is installed on the pipeline after the second pressure regulating valve 55.

[0043] like Figure 1 As shown, in one embodiment, the mixed gas supply system further includes a nitrogen purging line 91 and a bypass line 94. The nitrogen purging line 91 is connected to the first intake line 11 and the second intake line 12. One end of the bypass line 94 is connected to the mixed gas outlet line 14, and the other end of the bypass line 94 is connected to the connecting line 96. The nitrogen purging line 91 is used to supply nitrogen to the buffer tank 4 and each line for nitrogen purging to remove gas, water, and other impurities from the buffer tank 4 and each line (the system is purged with nitrogen before each system start-up for gas mixing). The purged nitrogen and the gas, water, and other impurities in each line are drawn into the vacuum generator 93 through the bypass line 94 and discharged through the discharge port 922.

[0044] like Figure 1 As shown, in one embodiment, a second manual diaphragm valve 511 is provided on the bypass pipeline 94.

[0045] like Figure 1As shown, in one embodiment, a three-way valve 57 is provided on the mixed gas inlet pipe 13. The first port of the three-way valve 57 is connected to the outlet of the mixing pipe 3, and the second port of the three-way valve 57 is connected to the inlet of the buffer tank 4. The mixed gas supply system also includes a branch pipe 95. One end of the branch pipe 95 is connected to the third port of the three-way valve 57, and the other end of the branch pipe 95 is connected to the connecting pipe 96.

[0046] Specifically, in this embodiment, by setting a three-way valve 57 and a branch pipe 95, the mixed gas supply system has two different nitrogen purging modes, allowing the user to select different nitrogen purging modes according to different operating conditions. The two nitrogen purging modes are as follows:

[0047] 1. Panel purging (i.e., nitrogen purging of the first intake pipe 11 and the second intake pipe 12, but not nitrogen purging of the buffer tank 4): During purging, adjust the three-way valve 57 to connect to the branch pipe 95 (i.e., the outlet of the mixing pipe 3 is connected to the branch pipe 95), and at the same time close the second manual diaphragm valve 511 and the relevant valves on the connecting pipe 96, and open the second pneumatic diaphragm valve 510. The nitrogen in the nitrogen purging pipe 91 enters the first intake pipe 11 and the second intake pipe 12 and then exits from the branch pipe 95 to the compressed gas pipe 92 (nitrogen does not enter the buffer tank 4), thereby purging the first intake pipe 11 and the second intake pipe 12 with nitrogen. After purging, use the vacuum pipe 81 to draw negative pressure on the buffer tank 4 and each pipe to exhaust the gas in the buffer tank 4 and each pipe.

[0048] 2. Overall purging (i.e., simultaneous nitrogen purging of the first intake pipe 11, the second intake pipe 12, and the buffer tank 4): During purging, adjust the three-way valve 57 to connect to the buffer tank 4 (i.e., the outlet of the mixing pipe 3 is connected to the buffer tank 4), and simultaneously open the second manual diaphragm valve 511 and the second pneumatic diaphragm valve 510. The nitrogen in the nitrogen purging pipe 91 enters the first intake pipe 11 and the second intake pipe 12, and then enters the buffer tank 4 from the mixed gas inlet pipe 13. It then exits from the mixed gas outlet pipe 14 and the bypass pipe 94 to the compressed gas pipe 92, thereby purging the first intake pipe 11, the second intake pipe 12, and the buffer tank 4 with nitrogen. After purging, use the vacuum pipe 81 to draw negative pressure into the buffer tank 4 and each pipe to exhaust the gas in the buffer tank 4 and each pipe.

[0049] like Figure 1 As shown, in one embodiment, a third pneumatic diaphragm valve 512 is provided on the mixed gas outlet pipeline 14.

[0050] like Figure 4 and Figure 5As shown, in another embodiment, a gas concentration detector 65 is provided on the first air intake pipe 11 and / or the second air intake pipe 12. The gas concentration detector 65 is connected to the control module 7 and is used to detect the concentration of gas in the first air intake pipe 11 and / or the second air intake pipe 12.

[0051] Specifically, to better control the mass flow controllers (first mass flow controller 63 and / or second mass flow controller 64), for some gas mixtures with high precision requirements and relatively low concentration ratios, a gas concentration detector 65 can be configured to detect the actual concentration of the gas in the gas source (the actual concentration of the gas in the gas source may differ from its target concentration), thereby assisting in the control of the mass flow controllers and improving control accuracy. For example, in this embodiment, such as Figure 4 As shown, when configuring a PH3 / H2 mixture with a concentration of 20 ppm, the first inlet pipe 11 delivers H2, and the second inlet pipe 12 delivers a 1% PH3 / H2 mixture. Since the concentration of the configured PH3 / H2 mixture is relatively low and the accuracy requirement is high, a gas concentration detector 65 is installed on the second inlet pipe 12 to detect the actual concentration of the source gas (1% PH3 / H2), thereby assisting in controlling the flow opening of the second mass flow controller 64 and improving control accuracy. Of course, when configuring a mixture with low accuracy requirements and a relatively high concentration ratio (e.g., a 3%–10% H2 / N2 mixture), the gas concentration detector 65 may not be required.

[0052] like Figure 1 and Figure 2 As shown, in one embodiment, the buffer tank 4 is provided with a gas inlet 41 and a gas outlet 42 at the bottom. The buffer tank 4 is provided with an inner tube 43, which extends from the bottom to the top of the buffer tank 4. The inner tube 43 is inclined inside the buffer tank 4. The bottom end of the inner tube 43 is connected to the mixed gas inlet pipe 13 through the gas inlet 41, and the top outlet of the inner tube 43 is located at the top of the buffer tank 4. The gas outlet 42 of the buffer tank 4 is connected to the mixed gas outlet pipe 14.

[0053] Specifically, through experiments, by setting an inner tube 43 inside the buffer tank 4, and the inner tube 43 being inclined, the mixing depth of the mixed gas can be greatly increased after entering the buffer tank 4, thereby increasing the mixing uniformity of the mixed gas and improving the concentration uniformity of the mixed gas, which is beneficial to improving the quality and yield of downstream products.

[0054] like Figure 1 and Figure 2As shown, in one embodiment, the inner tube 43 includes a vertically arranged vertical section 431 and an inclined section 432. The inclined section 432 is located above the vertical section 431. The bottom end of the vertical section 431 is connected to the mixed gas inlet pipe 13 through the gas inlet 41. The top end of the vertical section 431 is connected to the bottom end of the inclined section 432. The top outlet of the inclined section 432 is located at the top position inside the buffer tank 4.

[0055] As one implementation method, each pipeline is also equipped with relevant control valves (pneumatic diaphragm valves, manual diaphragm valves, etc.), which will not be described in detail here.

[0056] like Figure 1 As shown, the workflow of the mixed gas supply system in this embodiment is as follows:

[0057] 1. When the production process begins, the system automatically detects whether each parameter meets the requirements, including whether the pressure of the two gases before mixing is stable and whether the ambient temperature meets the process requirements; if all parameters are normal, the system will start working.

[0058] 2. Set the ratio and concentration of the two process gases, set the flow rate of one gas to a constant flow rate, and set the flow rate of the other gas according to the actual flow rate feedback value of this gas and the calculation result of the ratio algorithm.

[0059] 3. The first type of process gas in the first inlet pipe 11 and the second type of process gas in the second inlet pipe 12 are regulated by the first mass flow controller 63 and the second mass flow controller 64, respectively, and then enter the mixing pipe 3 according to the design ratio for preliminary mixing. At the same time, the composition ratio and / or concentration value of the mixed gas after preliminary mixing is detected by the first gas analyzer 61 to monitor whether its parameters are stable.

[0060] 4. The initially mixed gas is conveyed to buffer tank 4 for secondary mixing (deep mixing) to output a higher quality mixed gas to the downstream process equipment. After secondary mixing in buffer tank 4, the gas enters the mixed gas outlet pipeline 14, and the composition ratio and / or concentration value of the mixed gas after secondary mixing in buffer tank 4 are detected by a second gas analyzer 62. At this point, a logical judgment is made, and the following two cases are considered:

[0061] (1) The composition ratio and / or concentration of the mixed gas after secondary mixing are within the set range, which meets the requirements of the downstream process parameters. At this time, the third pneumatic diaphragm valve 512 opens and delivers the qualified mixed gas to the process machine.

[0062] (2) If the composition ratio and / or concentration value of the mixed gas after secondary mixing is not within the set range and cannot meet the requirements of the downstream process parameters, the mixed gas in the buffer tank 4 will be discharged to the discharge port 922 through the mixed gas outlet pipeline 14. At the same time, the control module 7 calculates the difference between the composition ratio and / or concentration value of the mixed gas detected by the second gas analyzer 62 and the set value, feeds the calculation result back to the front-end mass flow controller, and then adjusts the flow value of the mass flow controller according to the calculation result. Finally, the mixed gas can be output to the process machine after the composition ratio and / or concentration value of the mixed gas meets the standard and stabilizes.

[0063] The mixed gas supply system provided in this embodiment of the invention, by setting up a mixing pipe 3 and a buffer tank 4, allows the gas to undergo preliminary mixing in the mixing pipe 3 and the mixed gas inlet pipe 13, followed by secondary mixing (deep mixing) in the buffer tank 4, thereby improving the uniformity of the mixing of various gases in the mixed gas. Simultaneously, by setting up a first gas analyzer 61, a second gas analyzer 62, a first mass flow controller 63, and a second mass flow controller 64, the system can promptly detect whether the parameters of the mixed gas meet the standards and adjust the gas supply flow rate in a timely manner according to the current parameters, keeping the parameters of the mixed gas within the set range and maintaining stability, thereby improving the reliability of the system and the stability of production; moreover, it can flexibly adjust the gas supply parameters according to production needs, improving production efficiency. This mixed gas supply system solves the drawbacks of mixing gas from finished gas cylinders, eliminating problems such as delivery time, mixed gas quality, and gas outages. Moreover, from an economic perspective, compared with purchasing mixed gas from finished gas cylinders, this mixed gas supply system can significantly reduce costs.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A mixed gas supply system, characterized in that, It includes a first inlet pipe (11) for conveying the first type of process gas, a second inlet pipe (12) for conveying the second type of process gas, a mixing pipe (3), a buffer tank (4), a mixed gas supply pipe (15) for connecting to the process equipment, a first gas analyzer (61), a second gas analyzer (62), and a control module (7). The first intake pipe (11) and the second intake pipe (12) are connected in parallel and then connected to the inlet of the mixing pipe (3). The outlet of the mixing pipe (3) is connected to the inlet of the buffer tank (4) through the mixed gas inlet pipe (13). The outlet of the buffer tank (4) is connected to the mixed gas supply pipe (15) through the mixed gas outlet pipe (14). The first gas analyzer (61) is connected to the mixed gas inlet pipe (13) and is used to detect the composition ratio and / or concentration value of the mixed gas after preliminary mixing in the mixing pipe (3). The second gas analyzer (62) is connected to the mixed gas outlet pipe (14) and is used to detect the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank (4). The buffer tank (4) has a gas inlet (41) and a gas outlet (42) at its bottom. The buffer tank (4) has an inner tube (43) inside it. The inner tube (43) extends from the bottom of the buffer tank (4) to the top of the buffer tank (4) and is inclined inside the buffer tank (4). The bottom end of the inner tube (43) is connected to the mixed gas inlet pipe (13) through the gas inlet (41), and the top outlet of the inner tube (43) is located at the top of the buffer tank (4). The gas outlet (42) of the buffer tank (4) is connected to the mixed gas outlet pipe (14). The first intake pipe (11) is equipped with a first mass flow controller (63), and the second intake pipe (12) is equipped with a second mass flow controller (64). The first gas analyzer (61), the second gas analyzer (62), the first mass flow controller (63) and the second mass flow controller (64) are all connected to the control module (7) via signal. When the second gas analyzer (62) detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank (4) is within the set range, the mixed gas in the buffer tank (4) is transported to the mixed gas supply pipeline (15) through the mixed gas outlet pipeline (14); when the second gas analyzer (62) detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank (4) is not within the set value range, the control module (7) controls the first mass flow controller (63) and / or the second mass flow controller (64) to adjust their flow opening according to the difference between the composition ratio and / or concentration value of the mixed gas detected by the second gas analyzer (62) and the set value; The mixed gas supply system also includes a venting module (9), which is connected to the mixed gas outlet pipeline (14); when the second gas analyzer (62) detects that the composition ratio and / or concentration value of the mixed gas after secondary mixing in the buffer tank (4) is not within the set range, the mixed gas in the buffer tank (4) is discharged through the mixed gas outlet pipeline (14) and the venting module (9); The venting module (9) includes a compressed gas pipeline (92), one end of which is provided with a compressed gas inlet (921) and the other end of which is provided with a discharge port (922). A vacuum generator (93) is provided on the compressed gas pipeline (92). The mixed gas outlet pipeline (14) is connected to the vacuum generator (93) through a connecting pipeline (96). The vacuum generator (93) is used to generate negative pressure to draw the gas in the mixed gas outlet pipeline (14) into the vacuum generator (93) and discharge it through the discharge port (922). The mixed gas outlet pipeline (14) is equipped with a first pressure gauge (21), and the connecting pipeline (96) is equipped with a first pneumatic diaphragm valve (51). The first pressure gauge (21) and the first pneumatic diaphragm valve (51) are both connected to the control module (7) via signal. When the pressure value detected by the first pressure gauge (21) does not change within a period of time, the control module (7) controls the first pneumatic diaphragm valve (51) to open automatically so as to discharge the mixed gas in the buffer tank (4) through the discharge port (922).

2. The mixed gas supply system as described in claim 1, characterized in that, The connecting pipe (96) is also provided with a needle valve (58), a back pressure valve (52), and a second pressure gauge (22) in sequence.

3. The mixed gas supply system as described in claim 1, characterized in that, The mixed gas supply system further includes a nitrogen purging line (91) and a bypass line (94). The nitrogen purging line (91) is connected to the first intake line (11) and the second intake line (12). One end of the bypass line (94) is connected to the mixed gas outlet line (14), and the other end of the bypass line (94) is connected to the connecting line (96).

4. The mixed gas supply system as described in claim 3, characterized in that, A three-way valve (57) is provided on the mixed gas inlet pipe (13). The first port of the three-way valve (57) is connected to the outlet of the mixing pipe (3), and the second port of the three-way valve (57) is connected to the inlet of the buffer tank (4). The mixed gas supply system also includes a branch pipe (95). One end of the branch pipe (95) is connected to the third port of the three-way valve (57), and the other end of the branch pipe (95) is connected to the connecting pipe (96).

5. The mixed gas supply system as described in claim 1, characterized in that, A gas concentration detector (65) is provided on the first air intake pipe (11) and / or the second air intake pipe (12). The gas concentration detector (65) is connected to the control module (7) and is used to detect the concentration of gas in the first air intake pipe (11) and / or the second air intake pipe (12).

6. The mixed gas supply system as described in claim 1, characterized in that, The first intake pipe (11) is provided with a first pressure regulating valve (54), the second intake pipe (12) is provided with a second pressure regulating valve (55), and the mixed gas outlet pipe (14) is provided with a third pressure regulating valve (56).

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