A polishing liquid double-barrel supply and return system

Abstract

A kind of polishing liquid double-barreled liquid supply and return system has: metering barrel, import is equipped with raw liquid supply pipeline, outlet is equipped with metering barrel supply pipeline;First liquid supply barrel, via first valve connection water supply pipeline, via first raw liquid valve connection metering barrel supply pipeline, and by first liquid supply pipeline with machine table connection, first liquid supply pipeline is equipped with first liquid supply pump, first filter and first liquid supply valve;Second liquid supply barrel, via second valve connection water supply pipeline, via second raw liquid valve connection metering barrel supply pipeline, and by second liquid supply pipeline with machine table connection, second liquid supply pipeline is equipped with second liquid supply pump, second filter and second liquid supply valve;Recovery tank, import connection machine table, outlet via third valve connection first liquid supply barrel, via fourth valve connection second liquid supply barrel;Metering barrel, first liquid supply barrel, second liquid supply barrel are equipped with liquid level sensor.The utility model effectively improves the liquid exchange work efficiency, is helpful to promote yield.

Description

Technical Field

[0001] This invention relates to a dual-tank supply and return system for polishing slurry, belonging to the field of silicon wafer production and processing technology. Background Technology

[0002] Chemical mechanical polishing (CMP) is a method for planarizing or polishing substrates made of semiconductor materials or other types of materials. It is widely used in the integrated circuit (IC) manufacturing industry. CMP combines the corrosive effects of the chemical solution in the polishing slurry with the mechanical grinding of abrasive particles to achieve extremely high flatness and smoothness on silicon wafers.

[0003] In the polishing process of semiconductor materials such as silicon wafers, a continuous supply of polishing slurry is required to the polishing machine. Currently, the replacement of recycled polishing slurry involves manual draining and mixing, which is time-consuming and labor-intensive. Furthermore, the machine must be stopped during draining and mixing, and the mixed slurry exhibits poor stability, affecting the stability and output of the polishing process. Therefore, there is an urgent need for a highly automated polishing slurry supply and return system. Utility Model Content

[0004] The purpose of this invention is to propose a dual-tank supply and return system for polishing slurry, which effectively solves the problem of time-consuming and labor-intensive manual mixing, enables switching of supply tanks without stopping the machine, improves work efficiency, and enhances the stability of polishing slurry ratio, thus contributing to process stability and increased output.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A dual-tank supply and return system for polishing slurry, comprising: a metering tank, a first supply tank, a second supply tank, and a recovery tank, wherein... The metering tank is equipped with a raw liquid supply pipeline at its inlet, and a raw liquid supply valve is installed on the raw liquid supply pipeline; the metering tank is also equipped with a metering tank supply pipeline at its outlet. The first liquid supply tank is connected to the water supply pipeline via the first valve, and to the metering tank supply pipeline via the first raw liquid valve. It is also connected to the machine via the first liquid supply pipeline, which is equipped with a first liquid supply pump, a first filter, and a first liquid supply valve. The second liquid supply tank is connected to the water supply pipeline via the second valve, and to the metering tank supply pipeline via the second raw liquid valve. It is also connected to the machine via the second liquid supply pipeline. The second liquid supply pipeline is equipped with a second liquid supply pump, a second filter, and a second liquid supply valve. The inlet of the recycling bin is connected to the machine, and the outlet of the recycling bin is connected to the first liquid supply tank and the second liquid supply tank through a recycling pipeline. The recycling pipeline is equipped with a recycling pump and is connected to the first liquid supply tank via a third valve and to the second liquid supply tank via a fourth valve. The metering tank, the first liquid supply tank, and the second liquid supply tank are all equipped with liquid level sensors.

[0006] Furthermore, both the first and second liquid supply tanks are equipped with stirring devices.

[0007] Furthermore, the inlet of the first liquid supply pump is connected to the bottom of the first liquid supply tank, and the outlet of the first liquid supply pump is connected to the first filter. The first filter is connected to the machine via the first liquid supply valve. The inlet of the second liquid supply pump is connected to the bottom of the second liquid supply tank, and the outlet of the second liquid supply pump is connected to the second filter. The second filter is connected to the machine via the second liquid supply valve. The inlet of the recovery pump is connected to the bottom of the recovery tank, and the outlet of the recovery pump is connected to the first liquid supply tank and the second liquid supply tank via a recovery pipeline.

[0008] Furthermore, when the first supply tank is emptied, water is added to the first supply tank through the water supply pipeline, and the raw liquid is replenished from the metering tank to the first supply tank; after the raw liquid in the metering tank is discharged into the first supply tank, the first raw liquid valve is closed, and the stirring device of the first supply tank is started to carry out the mixing and circulation of polishing liquid. When the second supply tank is emptied, water is added to the second supply tank through the water supply pipeline, and the raw liquid is replenished from the metering tank to the second supply tank; after the raw liquid in the metering tank is discharged into the second supply tank, the second raw liquid valve is closed, and the stirring device of the second supply tank is started to carry out the mixing and circulation of polishing liquid. When the first supply tank supplies liquid to the machine, the first supply pump and the first supply valve open to supply liquid, while the recovery pump and the third valve open to recover the polishing liquid back to the first supply tank; when the second supply tank supplies liquid to the machine, the second supply pump and the second supply valve open to supply liquid, while the recovery pump and the fourth valve open to recover the polishing liquid back to the second supply tank.

[0009] Furthermore, the metering tank is equipped with a low liquid level sensor, a medium liquid level sensor, and a high liquid level sensor; the first supply tank is equipped with a low liquid level sensor, a medium liquid level sensor, and a high liquid level sensor; and the second supply tank is equipped with a low liquid level sensor, a medium liquid level sensor, and a high liquid level sensor.

[0010] Furthermore, when there is liquid in the metering tank, the low liquid level sensor and the liquid level sensor in the metering tank are triggered, while the high liquid level sensor in the metering tank is not triggered; when the metering tank is empty, the low liquid level sensor, the liquid level sensor in the metering tank, and the high liquid level sensor in the metering tank are all not triggered, and the raw liquid supply pipeline valve is opened to replenish the liquid until the low liquid level sensor and the liquid level sensor in the metering tank are triggered, while the high liquid level sensor in the metering tank is not triggered. When the first liquid supply tank contains liquid, the low liquid level sensor and the liquid level sensor in the first liquid supply tank are triggered, but the high liquid level sensor in the first liquid supply tank is not triggered; or the low liquid level sensor in the first liquid supply tank is triggered, but the liquid level sensor in the first liquid supply tank and the high liquid level sensor in the first liquid supply tank are not triggered. When there is liquid in the second liquid supply tank, the low liquid level sensor and the liquid level sensor in the second liquid supply tank are triggered, but the high liquid level sensor in the second liquid supply tank is not triggered; or the low liquid level sensor in the second liquid supply tank is triggered, but the liquid level sensor in the second liquid supply tank and the high liquid level sensor in the second liquid supply tank are not triggered.

[0011] Furthermore, all the pipeline valves are pneumatically controlled valves, and the first liquid supply pump, the second liquid supply pump, and the recovery pump are all pneumatic diaphragm pumps.

[0012] Furthermore, the system is equipped with the function of automatically switching between using the first liquid supply tank or the second liquid supply tank to supply liquid and recover liquid for the machine, and the first liquid supply tank and the second liquid supply tank can automatically mix liquid.

[0013] The advantages of this utility model are: The present invention proposes a dual-tank polishing slurry supply and return system, which effectively solves the problem of time-consuming and labor-intensive manual mixing, realizes the switching of supply tanks without stopping the machine, improves work efficiency, and improves the stability of polishing slurry ratio, which helps to stabilize the process and increase output. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a dual-tank supply and return system for polishing fluid according to this utility model.

[0015] Figure label: 1. First supply tank; 2. First supply pipeline; 3. First supply pump; 4. First filter; 5. First supply valve; 6. Second supply tank; 7. Second supply pipeline; 8. Second supply pump; 9. Second filter; 10. Second supply valve; 11. Recovery tank; 12. Recovery pipeline; 13. Recovery pump; 14. Third valve; 15. Fourth valve; 16. Metering tank; 17. Raw material supply pipeline; 18. Raw material supply valve; 19. Metering tank supply pipeline; 20. First raw material valve; 21. Second raw material valve; 22. 23. Water supply pipeline; 24. First valve; 25. Second valve; 26. Machine platform; 27. Low liquid level sensor of the first liquid supply tank; 28. Liquid level sensor in the first liquid supply tank; 29. ​​High liquid level sensor of the first liquid supply tank; 30. Low liquid level sensor of the second liquid supply tank; 31. Liquid level sensor in the second liquid supply tank; 32. Low liquid level sensor of the metering tank; 33. Liquid level sensor in the metering tank; 34. High liquid level sensor of the metering tank; 35. Stirring device of the first liquid supply tank; 36. Stirring device of the second liquid supply tank. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this does not imply any limitation on the scope of protection of the present invention.

[0017] like Figure 1 As shown, the polishing slurry dual-tank supply and return system proposed in this utility model comprises four parts: a raw slurry metering unit, a first supply unit, a second supply unit, and a recovery unit. The raw slurry metering unit includes a metering tank 16 and associated piping and valves. The first supply unit includes a first supply tank 1, a first supply pump 3, a first filter 4, a first supply tank stirring device 35, a water supply unit, and associated piping and valves. The second supply unit includes a second supply tank 6, a second supply pump 8, a second filter 9, a second supply tank stirring device 36, a water supply unit, and associated piping and valves. The recovery unit includes a recovery tank 11, a recovery pump 13, and associated piping and valves.

[0018] Specifically, the metering tank 16 of the raw material metering unit provides polishing liquid raw material. The inlet of the metering tank 16 is provided with a raw material supply pipeline 17, and the raw material supply pipeline 17 is provided with a raw material supply valve 18. The outlet of the metering tank 16 is connected to the first supply tank 1 and the second supply tank 6 through the metering tank supply pipeline 19, and the metering tank supply pipeline 19 is provided with a first raw material valve 20 and a second raw material valve 21.

[0019] The first liquid supply tank 1 of the first liquid supply unit is connected to the machine base 25 through the first liquid supply pipeline 2. The first liquid supply pipeline 2 is equipped with a first liquid supply pump 3, a first filter 4 and a first liquid supply valve 5. The inlet of the first liquid supply pump 3 is connected to the bottom of the first liquid supply tank 1, and the outlet of the first liquid supply pump 3 is connected to the first filter 4. The first filter 4 is connected to the machine base through the first liquid supply valve 5. The first liquid supply tank 1 is connected to the water supply pipeline 22 through the first valve 23. The first liquid supply tank 1 is equipped with a first liquid supply tank stirring device 35.

[0020] The second liquid supply tank 6 of the second liquid supply unit is connected to the machine base 25 through the second liquid supply pipeline 7. The second liquid supply pipeline 7 is equipped with a second liquid supply pump 8, a second filter 9, and a second liquid supply valve 10. The inlet of the second liquid supply pump 8 is connected to the bottom of the second liquid supply tank 6, and the outlet of the second liquid supply pump 8 is connected to the second filter 9. The second filter 8 is connected to the machine base through the second liquid supply valve 10. The second liquid supply tank 6 is connected to the water supply pipeline 22 through the second valve 24. The second liquid supply tank 6 is equipped with a second liquid supply tank stirring device 36.

[0021] The inlet of the recycling tank 11 of the recycling unit is connected to the outlet of the machine 25, and is connected to the first supply tank 1 and the second supply tank 6 respectively through the recycling pipeline 12. A recycling pump 13 is provided on the recycling pipeline 12. The inlet of the recycling pump 13 is connected to the bottom of the recycling tank, and the outlet of the recycling pump 13 is connected to the first supply tank 1 and the second supply tank 6 through the recycling pipeline. A third valve 14 is provided on the recycling pipeline connected to the first supply tank 1, and a fourth valve 15 is provided on the recycling pipeline connected to the second supply tank 6.

[0022] In the dual-tank polishing slurry supply and return system of this utility model, the metering tank 16, the first supply tank 1, and the second supply tank 6 are all equipped with level sensors. Specifically, the metering tank 16 is equipped with a low level sensor 32, a medium level sensor 33, and a high level sensor 34; the first supply tank 1 is equipped with a low level sensor 26, a medium level sensor 27, and a high level sensor 28; and the second supply tank is equipped with a low level sensor 29, a medium level sensor 30, and a high level sensor 31. All valves in the aforementioned pipelines are pneumatically controlled valves, and the pumps in each tank (first supply pump 3, second supply pump 8, and return pump 13) are all pneumatic diaphragm pumps. The system also features an automatic switching function to use either the first or second supply tank for machine supply and return, and the first and second supply tanks can be automatically mixed.

[0023] In practical applications, the operation process of the dual-tank polishing slurry supply and return system of this invention is as follows: The overall workflow in the automatic mode of the system is as follows: The first liquid supply unit preferably enters the mixing state. The raw material from the plant enters the metering tank 16 through the raw material supply pipeline 17. The raw material in the metering tank 16 is mixed with pure water in the first liquid supply tank 1. After the stirring device 35 of the first liquid supply tank is started to mix evenly, the first liquid supply unit enters the liquid supply state. The mixed polishing liquid is supplied to the machine 25 through the first liquid supply pump 3. The polishing liquid after the silicon wafer is processed by the machine 25 flows into the recovery tank 11. The polishing liquid in the recovery tank 11 is recovered to the first liquid supply tank 1 through the recovery pump 13. While the first liquid supply unit is in the liquid supply state, the second liquid supply unit enters the mixing state. The raw material from the plant enters the metering tank 16 through the raw material supply pipeline 17. The raw material in the metering tank 16 is mixed with pure water in the second liquid supply tank 6. After the stirring device 36 of the second liquid supply tank is started to mix evenly, the second liquid supply unit enters the standby state. When the first liquid supply unit ends its liquid supply state, the second liquid supply unit automatically switches to the liquid supply state. The mixed polishing slurry is supplied to the machine 25 through the second liquid supply pump 8. The polishing slurry after the silicon wafer is processed by the machine 25 flows into the recovery tank 11. The polishing slurry in the recovery tank 11 is recovered to the second liquid supply tank 6 through the recovery pump 13. At this time, the first liquid supply unit drains the liquid, mixes the liquid again, and then enters the standby state. When the second liquid supply unit ends its liquid supply state, the first liquid supply unit automatically switches to the liquid supply state, drains the liquid, mixes the liquid again, and then enters the standby state. This cycle continues.

[0024] In the specific implementation process, under the automatic operation mode, only one of the liquid supply systems in the first liquid supply unit and the second liquid supply unit can be in the liquid supply state at the same time, while the other liquid supply system is in the mixing state or in standby state; when neither of the two liquid supply systems meets the liquid supply state and mixing is required, one of the liquid supply systems will be prioritized to mix and enter the liquid supply state before the other liquid supply system can start mixing.

[0025] When the metering tank 16 contains liquid, the low level sensor 32 and the medium level sensor 33 of the metering tank are triggered, while the high level sensor 34 of the metering tank is not triggered. When the metering tank 16 is empty, the low level sensor 32, the medium level sensor 33, and the high level sensor 34 of the metering tank are not triggered. At this time, the raw material supply valve 18 is opened, and the raw material from the plant is supplied to the metering tank 16 through the raw material supply pipeline until the low level sensor 32 and the medium level sensor 33 of the metering tank are triggered, and the high level sensor 34 of the metering tank is not triggered, after which the raw material supply valve 18 is closed. When the first liquid supply unit enters the liquid supply state, the low liquid level sensor 26 and the liquid level sensor 27 in the first liquid supply tank are triggered, while the high liquid level sensor 28 in the first liquid supply tank is not triggered; or the low liquid level sensor 26 in the first liquid supply tank is triggered, while the liquid level sensor 27 and the high liquid level sensor 28 in the first liquid supply tank are not triggered; when the machine has a liquid demand, a liquid demand signal is sent to the first liquid supply unit. At this time, the first liquid supply pump 3 starts, the liquid supply valve 5 in the first liquid supply tank opens, and the polishing liquid that has been mixed in the first liquid supply tank 1 is supplied to the machine 25 along the first liquid supply pipeline 2 under the drive of the first liquid supply pump 3; at the same time, the recovery pump 13 starts, the third valve 14 opens, and the polishing liquid in the recovery tank 11 is recovered to the first liquid supply tank 1 under the drive of the recovery pump 13; when the first liquid supply tank 1 is in the liquid supply state, the first liquid supply tank stirring device 35 is always in the running state.

[0026] When the first liquid supply unit is in a mixed state and the first liquid supply tank 1 is empty, the low liquid level sensor 26, the liquid level sensor 27, and the high liquid level sensor 28 of the first liquid supply tank are not triggered. First, pure water is added to the first liquid supply tank 1, the first valve 23 is opened, and pure water enters the first liquid supply tank 1 along the water supply pipe 22 and the first valve 23 until the low liquid level sensor 26 and the liquid level sensor 27 of the first liquid supply tank are triggered, then the first valve 23 is closed to complete the addition of pure water. Then, the first raw liquid valve 20 is opened, and the raw liquid in the metering tank 16 flows along the metering tank supply pipe 19 and the first raw liquid... Valve 20 enters the first supply tank 1 until the raw liquid in the metering tank 16 is emptied. After the low level sensor 32, the medium level sensor 33, and the high level sensor 34 of the metering tank are all not triggered, the first raw liquid valve 20 is closed to complete the addition of raw liquid. During the mixing process, the stirring device 35 of the first supply tank is always in the start state. After the pure water and raw liquid are fully mixed, the system selects the first supply unit according to the current state of the second supply unit. When the second supply unit is in the supply state, the first supply unit changes to the standby state; when the second supply unit is in the non-supply state, the first supply unit changes to the supply state. When the second liquid supply unit is in the liquid supply state, the low liquid level sensor 29 of the second liquid supply tank and the liquid level sensor 30 in the second liquid supply tank are triggered, while the high liquid level sensor 31 of the second liquid supply tank is not triggered; or the low liquid level sensor 29 of the second liquid supply tank is triggered, while the liquid level sensor 30 in the second liquid supply tank and the high liquid level sensor 31 of the second liquid supply tank are not triggered; when the machine has a liquid demand, the liquid demand signal is sent to the second liquid supply unit. At this time, the second liquid supply pump 8 is started, the liquid supply valve 10 of the second liquid supply tank is opened, and the polishing liquid that has been mixed in the second liquid supply tank 6 is supplied to the machine 25 along the first liquid supply pipeline 7 under the drive of the second liquid supply pump 8. At the same time, the recovery pump 13 is started, the fourth valve 15 is opened, and the polishing liquid in the recovery tank 11 is recovered to the second liquid supply tank 6 under the drive of the recovery pump 13; when in the liquid supply state, the stirring device 36 of the second liquid supply tank is always in the running state.

[0027] When the second liquid supply unit is in a mixed state and the second liquid supply tank 6 is empty, the low liquid level sensor 29, the liquid level sensor 30, and the high liquid level sensor 31 of the second liquid supply tank are not triggered. First, pure water is added to the second liquid supply tank 6, the second valve 24 is opened, and pure water enters the second liquid supply tank 6 along the water supply pipe 22 and the second valve 24 until the low liquid level sensor 29 and the liquid level sensor 30 of the second liquid supply tank are triggered, then the second valve 24 is closed to complete the addition of pure water. Then, the second raw liquid valve 21 is opened, and the raw liquid in the metering tank 16 flows along the metering tank supply pipe 19 and the second raw liquid supply pipe 21. Valve 21 enters the second supply tank 6 until the raw liquid in the metering tank 16 is emptied. After the low level sensor 32, the medium level sensor 33, and the high level sensor 34 of the metering tank are not triggered, the second raw liquid valve 21 is closed to complete the addition of raw liquid. During the mixing process, the stirring device 36 of the second supply tank is always in the start state. After the pure water and raw liquid are fully mixed, the system selects the second supply unit according to the current state of the first supply unit. When the first supply unit is in the supply state, the second supply unit changes to the standby state; when the first supply unit is in the non-supply state, the second supply unit changes to the supply state. As described above, the polishing slurry dual-tank supply and return system proposed in this utility model can automatically mix, supply, and recover slurry in both the first and second supply units, and the two supply systems can automatically switch between each other while always meeting the machine's slurry requirements.

[0028] This invention effectively solves the problem of time-consuming and labor-intensive manual mixing, enables switching of the liquid supply tank without stopping the machine, improves work efficiency, and enhances the stability of the polishing liquid ratio, which helps to stabilize the process and increase output.

Claims

1. A dual-tank supply and return system for polishing slurry, characterized in that, The system includes a metering tank, a first supply tank, a second supply tank, and a recovery tank. The metering tank is equipped with a raw liquid supply pipeline at its inlet, and a raw liquid supply valve is installed on the raw liquid supply pipeline; the metering tank is also equipped with a metering tank supply pipeline at its outlet. The first liquid supply tank is connected to the water supply pipeline via the first valve, and to the metering tank supply pipeline via the first raw liquid valve. It is also connected to the machine via the first liquid supply pipeline, which is equipped with a first liquid supply pump, a first filter, and a first liquid supply valve. The second liquid supply tank is connected to the water supply pipeline via the second valve, and to the metering tank supply pipeline via the second raw liquid valve. It is also connected to the machine via the second liquid supply pipeline. The second liquid supply pipeline is equipped with a second liquid supply pump, a second filter, and a second liquid supply valve. The inlet of the recycling bin is connected to the machine, and the outlet of the recycling bin is connected to the first liquid supply tank and the second liquid supply tank through a recycling pipeline. The recycling pipeline is equipped with a recycling pump and is connected to the first liquid supply tank via a third valve and to the second liquid supply tank via a fourth valve. The metering tank, the first liquid supply tank, and the second liquid supply tank are all equipped with liquid level sensors.

2. The dual-tank polishing slurry supply and return system according to claim 1, characterized in that: Both the first and second liquid supply tanks are equipped with stirring devices.

3. The polishing slurry dual-tank supply and return system according to claim 1 or 2, characterized in that: The inlet of the first liquid supply pump is connected to the bottom of the first liquid supply tank, and the outlet of the first liquid supply pump is connected to the first filter. The first filter is connected to the machine via the first liquid supply valve. The inlet of the second liquid supply pump is connected to the bottom of the second liquid supply tank, and the outlet of the second liquid supply pump is connected to the second filter. The second filter is connected to the machine via the second liquid supply valve. The inlet of the recovery pump is connected to the bottom of the recovery tank, and the outlet of the recovery pump is connected to the first liquid supply tank and the second liquid supply tank via a recovery pipeline.

4. The polishing slurry dual-tank supply and return system according to claim 1 or 2, characterized in that: When the first supply tank is emptied, water is added to the first supply tank through the water supply pipeline, and the raw liquid is replenished from the metering tank to the first supply tank; after the raw liquid in the metering tank is discharged into the first supply tank, the first raw liquid valve is closed, and the stirring device of the first supply tank is started to carry out the mixing and circulation of polishing liquid. When the second supply tank is emptied, water is added to the second supply tank through the water supply pipeline, and the raw liquid is replenished from the metering tank to the second supply tank; after the raw liquid in the metering tank is discharged into the second supply tank, the second raw liquid valve is closed, and the stirring device of the second supply tank is started to carry out the mixing and circulation of polishing liquid. When the first supply tank supplies liquid to the machine, the first supply pump and the first supply valve open to supply liquid, while the recovery pump and the third valve open to recover the polishing liquid back to the first supply tank; when the second supply tank supplies liquid to the machine, the second supply pump and the second supply valve open to supply liquid, while the recovery pump and the fourth valve open to recover the polishing liquid back to the second supply tank.

5. The polishing slurry dual-tank supply and return system according to claim 1 or 2, characterized in that: The metering tank is equipped with a low liquid level sensor, a medium liquid level sensor, and a high liquid level sensor; the first supply tank is equipped with a low liquid level sensor, a medium liquid level sensor, and a high liquid level sensor; the second supply tank is equipped with a low liquid level sensor, a medium liquid level sensor, and a high liquid level sensor.

6. The polishing slurry dual-tank supply and return system according to claim 5, characterized in that: When there is liquid in the metering tank, the low liquid level sensor and the liquid level sensor in the metering tank are triggered, while the high liquid level sensor in the metering tank is not triggered. When the metering tank is empty, none of the low liquid level sensor, the liquid level sensor in the metering tank, and the high liquid level sensor in the metering tank are triggered. The valve of the raw liquid supply pipeline is opened to replenish the liquid until the low liquid level sensor and the liquid level sensor in the metering tank are triggered, while the high liquid level sensor in the metering tank is not triggered. When the first liquid supply tank contains liquid, the low liquid level sensor and the liquid level sensor in the first liquid supply tank are triggered, but the high liquid level sensor in the first liquid supply tank is not triggered; or the low liquid level sensor in the first liquid supply tank is triggered, but the liquid level sensor in the first liquid supply tank and the high liquid level sensor in the first liquid supply tank are not triggered. When there is liquid in the second liquid supply tank, the low liquid level sensor and the liquid level sensor in the second liquid supply tank are triggered, but the high liquid level sensor in the second liquid supply tank is not triggered; or the low liquid level sensor in the second liquid supply tank is triggered, but the liquid level sensor in the second liquid supply tank and the high liquid level sensor in the second liquid supply tank are not triggered.

7. The dual-tank polishing slurry supply and return system according to claim 1 or 2, characterized in that: All pipeline valves are pneumatically controlled valves, and the first liquid supply pump, the second liquid supply pump, and the recovery pump are all pneumatic diaphragm pumps.

8. The dual-tank polishing slurry supply and return system according to claim 1 or 2, characterized in that, The system is equipped with the function of automatically switching between using the first liquid supply tank or the second liquid supply tank to supply liquid and recover liquid for the machine, and the first liquid supply tank and the second liquid supply tank can be automatically mixed.

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