Monitoring system and method for grinding and polishing air floating main shaft

Abstract

The invention relates to a monitoring system and method for a grinding and polishing air floatation spindle, the monitoring system at least comprises a sensor acquisition module, a spindle system, a power supply system and a monitoring control module, the sensor acquisition module is arranged on the spindle system, and the sensor acquisition module is electrically connected with the spindle system through the power supply system; wherein the sensor acquisition module comprises a plurality of sensors, and the plurality of sensors are used for acquiring temperature difference and / or pressure difference data of the main shaft system and transmitting signals to the monitoring control module. According to the invention, feedback can be made in time when the air supply pressure changes, the water supply pressure changes and the main shaft works abnormally, whether the main shaft work factory affair condition can reach the normal work standard or not can be accurately monitored, and a guarantee is provided for the stable work of the main shaft.

Description

Technical Field

[0001] This application relates to the technical field of high-speed precision machining, and particularly to a monitoring system and method for the temperature difference, pressure difference of the air-bearing - motor cooling water, spindle speed, and motor operating temperature of a grinding and polishing air-bearing spindle. Background Art

[0002] The grinding and polishing air-bearing spindle is an advanced technology in the field of high-speed precision machining, mainly composed of a motor, an air-bearing, a grinding wheel connector, etc. The thinning machine is a device commonly used for ultra-high-precision grinding and thinning of semiconductor materials, focusing on the high-precision grinding of semiconductor materials, removing the excess substrate of the wafer before packaging to ensure an accurate thickness. This step helps subsequent process flows such as reducing packaging difficulty, improving chip heat dissipation efficiency, reducing internal stress, and enhancing electrical performance. The air-bearing spindle, as the core component of the wafer thinning machine, consists of a motor and an air-bearing. The motor drives the air-bearing to rotate, that is, heat will accumulate during the operation of the motor and the bearing, and water cooling is required for temperature reduction. And this system is to detect air pressure, water temperature, water pressure, motor stator temperature, motor rotor speed, etc., which is an important monitoring means to ensure the normal operation of the spindle motor, spindle air supply, and water supply, and plays a crucial role in the wafer thinning process.

[0003] The monitoring system for the grinding and polishing air-bearing spindle is a monitoring system dedicated to real-time monitoring of the temperature difference, pressure difference of the air-bearing - motor cooling water, spindle speed, and motor operating temperature on the grinding and polishing air-bearing spindle of the thinning machine. It mainly consists of an air-bearing inlet pressure sensor, an air-bearing - motor cooling water inlet pressure sensor, an air-bearing pressure difference (integrated temperature) sensor, a motor stator cooling pressure difference (integrated temperature) sensor, a monitoring module, etc.

[0004] The current monitoring system for the grinding and polishing air-bearing spindle is an important guarantee for the stable operation of the spindle. If the air supply of the air-bearing and the monitoring of the cooling water of each part are ignored, situations such as high-temperature burnout of the motor and spindle seizure are likely to occur, affecting the stability of the spindle.

[0005] The foreign detection method for the pressure difference is to measure it with multiple gauge pressure sensors and subtract the measured values using a software algorithm. However, this algorithm has problems such as cumbersome operation, poor applicability, and easy errors. The existing grinding and polishing air-bearing spindles in China do not pay enough attention to spindle monitoring. Most spindles only perform real-time monitoring of the motor stator temperature and do not perform real-time monitoring of the spindle air source and water source, which is a huge hidden danger to the operation of the spindle. If situations such as spindle air cut-off, too high spindle cooling water temperature, failure to open or cooling water flow interruption occur, the spindle is extremely likely to have problems such as high-temperature burnout and seizure. Summary of the Invention

[0006] To solve the above problems, the present invention provides a monitoring system and method for a grinding and polishing air-bearing spindle, which can monitor the temperature difference and pressure difference of the grinding and polishing air-bearing spindle in real time, observe the spindle quality at any time, diagnose in real time, and reduce and avoid the motor burnout and spindle seizure caused by the interruption of air supply and water supply of the grinding and polishing air-bearing spindle.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A monitoring system for a grinding and polishing air-bearing spindle, the monitoring system at least includes a sensor acquisition module, a spindle system, a power supply system and a monitoring and control module. The sensor acquisition module is arranged on the spindle system, and the sensor acquisition module is electrically connected to the spindle system through the power supply system;

[0009] Among them, the sensor acquisition module includes a plurality of sensors. The plurality of sensors collect the temperature difference and / or pressure difference data of the spindle system and transmit signals to the monitoring and control module.

[0010] According to an embodiment of the present invention, the sensor acquisition module at least includes a first pressure sensor, a second pressure sensor, a first differential pressure sensor, a second differential pressure sensor, a temperature sensor and a photoelectric sensor. The temperature sensor and the photoelectric sensor are separately installed on the spindle system, and the first pressure sensor, the second pressure sensor, the first differential pressure sensor and the second differential pressure sensor are integrally integrated in the sensor acquisition module.

[0011] According to an embodiment of the present invention, the first pressure sensor is connected to the air inlet pipeline of the air-bearing, and the air inlet pipeline of the air-bearing is an independent pipeline.

[0012] According to an embodiment of the present invention, the second pressure sensor is arranged on the inlet and outlet pipeline of the motor cooling water, and the inlet and outlet pipeline of the motor cooling water is also connected to one end of the high-pressure side of the first differential pressure sensor. One end of the low-pressure side of the first differential pressure sensor is connected to the parallel inlet and outlet pipeline of the motor, and the parallel inlet and outlet pipeline of the motor is also connected to one end of the high-pressure side of the second differential pressure sensor. One end of the low-pressure side of the second differential pressure sensor is connected to the inlet and outlet pipeline of the air-bearing cooling water.

[0013] According to an embodiment of the present invention, the inlet and outlet pipeline of the motor cooling water and the parallel inlet and outlet pipeline of the motor are also respectively connected to the temperature sensor.

[0014] According to an embodiment of the present invention, the second pressure sensor, the first differential pressure sensor and the second differential pressure sensor are in series, and data acquisition is carried out in sequence.

[0015] According to an embodiment of the present invention, the air bearing intake pipeline, the motor cooling water inlet and outlet pipeline, the parallel motor inlet and outlet pipeline, and the air bearing cooling water inlet and outlet pipeline are all introduced into the sensor acquisition module through pipe joints, and the sensors integrated in the sensor acquisition module as a whole are all connected into a whole using an adapter structure plate and pipelines.

[0016] The present invention also provides a monitoring method for a monitoring system of a grinding and polishing air floating spindle. The sensors of the sensor acquisition module respectively collect data on the spindle motor speed, motor stator temperature, air bearing intake end air pressure, motor cooling water inlet water pressure, motor cooling water inlet and outlet water pressure difference and water temperature, and bearing thrust cooling water pressure difference and water temperature of the grinding and polishing air floating spindle, and transmit signals to the monitoring and control module to monitor the temperature difference and pressure difference before and after cooling of the grinding and polishing air floating spindle.

[0017] According to an embodiment of the present invention, the compressed air entering the grinding and polishing air floating spindle is first connected to the corresponding interface of the monitoring system, and after the air pressure is monitored to meet the standard, it is then connected into the grinding and polishing air floating spindle.

[0018] According to an embodiment of the present invention, the motor cooling water and the thrust cooling water are both passed into the monitoring system before entering the water, and the water temperature and water pressure are detected once first. The cooling water that has passed through the cooling cycle is passed into the monitoring system again, so as to monitor and obtain the temperature difference and pressure difference before and after cooling of the grinding and polishing air floating spindle.

[0019] Advantages of the present invention:

[0020] Aiming at the shortcomings of the prior art, the present invention provides a monitoring system and method for a grinding and polishing air floating spindle. This monitoring system uses a variety of integrated sensors to respectively and real-time monitor the spindle motor speed, motor stator temperature, air bearing intake end air pressure, motor cooling water inlet water pressure, motor cooling water inlet and outlet water pressure difference and water temperature, and bearing thrust cooling water pressure difference and water temperature of the grinding and polishing air floating spindle, etc., so as to observe the spindle quality at any time and diagnose it in real time, and reduce and avoid problems such as motor burnout and spindle seizure caused by interrupted air supply and interrupted water supply of the grinding and polishing air floating spindle. Brief Description of the Drawings

[0021] Figure 1 Schematic diagram of the monitoring system of the present invention;

[0022] Figure 2 Schematic diagram of the sensor acquisition module of the present invention;

[0023] Figure 3 Schematic diagram of the monitoring system principle of the present invention;

[0024] Figure 4 Schematic diagram of the monitoring pipeline water and gas flow direction structure of the present invention.

[0025] Reference numerals:

[0026] 1 - Air - floating bearing air inlet pipe; 2 - Motor cooling water inlet and outlet pipe; 3 - Parallel motor inlet and outlet pipe; 4 - Air - floating bearing cooling water inlet and outlet pipe; 10 - First pressure sensor; 20 - Second pressure sensor; 30 - First differential pressure sensor; 40 - Second differential pressure sensor; 50 - Temperature sensor; 60 - Photoelectric sensor; 70 - Surface A; 71 - PC8 quick - connect plug; 80 - Surface B; 81 - Flange; 82 - Interface. Detailed implementation manners

[0027] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0028] The embodiments of the present invention, examples of which are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The terms "first", "second", "third", etc. (if any) in the description and claims of the present invention and in the accompanying drawings are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such objects can be interchanged under appropriate circumstances. In addition, the terms "include" and "have" and any variations thereof are intended to cover non - exclusive inclusion. The directional terms mentioned in the present invention, such as: up, down, left, right, front, back, inside, outside, side, etc., are only with reference to the directions in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention. In addition, the present invention repeats reference numerals and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0029] The wafer thinning machine is equipped with an air spindle that rotates at high speed. Due to the high-speed rotation of the spindle, the motor stator heats up and heat is generated by gas friction. Water needs to be introduced for cooling. Therefore, it is necessary to measure the intake air pressure (absolute pressure is about 0.45 - 0.55 MPa), the inlet water temperature (about 15 - 20 °C), the outlet water temperature (about 17 - 22 °C), the inlet water pressure (absolute pressure is about 500 - 600 Kpa), the first inlet and outlet differential pressure (about 100 Kpa), the second inlet and outlet differential pressure (about 100 Kpa), the stator temperature (about 15 - 25 °C), the motor speed, etc. The above parameters are monitored in real time to judge the cooling effect, the working condition of the spindle, and determine whether the external plant meets the required values.

[0030] Based on this, the present invention provides a monitoring system for a polishing air-bearing spindle, which is used for monitoring the temperature difference and pressure difference of the polishing air-bearing spindle. As Figure 1 shown, the monitoring system at least includes a sensor acquisition module, a spindle system, a power supply system, and a monitoring and control module (not shown in the figure). The sensor acquisition module is arranged on the spindle system, and the sensor acquisition module is electrically connected to the spindle system through the power supply system.

[0031] Among them, the sensor acquisition module includes multiple sensors. The multiple sensors acquire the temperature difference and / or pressure difference data of the spindle system and transmit signals to the monitoring and control module.

[0032] Specifically, the sensor acquisition module at least includes a first pressure sensor 10, a second pressure sensor 20, a first differential pressure sensor 30, a second differential pressure sensor 40, a temperature sensor 50, and a photoelectric sensor 60.

[0033] Preferably, the first pressure sensor 10 is an air-bearing intake air pressure sensor, the second pressure sensor 20 is a floating bearing - motor cooling water inlet pressure sensor, the first differential pressure sensor 30 is a motor stator cooling water differential pressure sensor, the second differential pressure sensor 40 is an air-bearing thrust differential pressure sensor, and the temperature sensor 50 is a motor stator temperature sensor.

[0034] Preferably, since the temperature sensor 50 and the photoelectric sensor 60 do not need to pass through the water and gas paths, the temperature sensor 50 and the photoelectric sensor 60 are separately installed on the spindle system and are not integrated in the sensor acquisition module. The remaining first pressure sensor 10, second pressure sensor 20, first differential pressure sensor 30, and second differential pressure sensor 40 are integrated into the sensor acquisition module as a whole.

[0035] Specifically, the sensor acquisition module is installed in the top area of the spindle of the spindle system by means of integral screw fixation. Preferably, the installation size is arc-shaped 66.5×100 mm. For example, the size of the sensor acquisition module is as Figure 2 shown.

[0036] The inlet and outlet of water and gas, as well as the connecting pipes, are all introduced through pipe connectors and integrated into the sensor acquisition module. After the data of the temperature sensor 50 and the photoelectric sensor 60 are acquired, they are also introduced into the sensor acquisition module.

[0037] Specifically, the sensor acquisition module includes an A side 70 and a B side 80. There are multiple PC8 quick-connect plugs 71 arranged on the A side 70. Preferably, there are 8 PC8 quick-connect plugs 71 arranged on the A side 70, which are respectively the air source inlet, the water source / thrust H end water inlet, the thrust L end / motor H end water inlet, the motor L end water inlet, the air source outlet, the water source / thrust H end water outlet, the thrust L end / motor H end water outlet, and the water outlet. There is a flange 81 on the B side 80. The flange 81 is provided with a through hole. Preferably, the diameter of the through hole is 7 mm. There are also multiple interfaces 82 arranged on the B side 80. Preferably, there are 5 interfaces 82, which are respectively the first temperature interface, the second temperature interface, the third temperature interface, the rotational speed sensor interface, and the power supply interface.

[0038] As Figure 3 shown, the monitoring system of the present invention further includes 4 pressure pipelines, which are respectively the air bearing inlet air pipeline 1, the motor cooling water inlet and outlet pipeline 2, the parallel motor inlet and outlet pipeline 3, and the air bearing cooling water inlet and outlet pipeline 4.

[0039] Furthermore, the air bearing inlet air pipeline 1 where the first pressure sensor 10 is located is an independent pipeline, and the motor cooling water inlet and outlet pipeline 2, the parallel motor inlet and outlet pipeline 3, and the air bearing cooling water inlet and outlet pipeline 4 where the second pressure sensor 20 is located are series pipelines. The motor cooling water inlet and outlet pipeline 2 and the parallel motor inlet and outlet pipeline 3 are connected in series through the first differential pressure sensor 30, and the parallel motor inlet and outlet pipeline 3 and the air bearing cooling water inlet and outlet pipeline 4 are connected in series through the second differential pressure sensor 40.

[0040] Specifically, the air bearing inlet air pipeline 1 is connected to the first pressure sensor 10, and the first pressure sensor 10 is arranged on the air bearing inlet air pipeline 1.

[0041] The motor cooling water inlet and outlet pipeline 2 is connected to the second pressure sensor 20, and the second pressure sensor 20 is arranged on the motor cooling water inlet and outlet pipeline 2. Moreover, the motor cooling water inlet and outlet pipeline 2 is also connected to one end of the high-pressure side of the first differential pressure sensor 30. One end of the low-pressure side of the first differential pressure sensor 30 is connected to the parallel motor inlet and outlet pipeline 3, and the parallel motor inlet and outlet pipeline 3 is also connected to one end of the high-pressure side of the second differential pressure sensor 40. One end of the low-pressure side of the second differential pressure sensor 40 is connected to the air bearing cooling water inlet and outlet pipeline 4.

[0042] In addition, the motor cooling water inlet and outlet pipeline 2 and the parallel motor inlet and outlet pipeline 3 are also respectively connected to the temperature sensor 50.

[0043] Furthermore, the four pressure lines have a total of eight PC8 connectors, corresponding to the PC8 quick-connect plugs 71 on the A surface 70 of the sensor acquisition module.

[0044] Specifically, the two ends of the air bearing air inlet pipe 1 are the air inlet end and the air outlet end respectively; one end of the motor cooling water inlet and outlet pipe 2 is the water inlet end, and the other end is the water inlet / outlet end; one end of the parallel motor water inlet and outlet pipe 3 is the water inlet / outlet end, and the other end is the water outlet end; the two ends of the air bearing cooling water inlet and outlet pipe 4 are the water inlet end and the water outlet end respectively.

[0045] Thus, the second pressure sensor 20, the first differential pressure sensor 30 and the second differential pressure sensor 40 are in a series relationship and collect data in sequence.

[0046] Specifically, Figure 4 As shown, in the schematic diagram of the water vapor trend in the monitoring pipeline of the present invention, the first pressure sensor 10 is connected in series at position ①, the second pressure sensor 20 is connected in series at position ②, the first differential pressure sensor 30 is connected in parallel between positions ② and ③, and the second differential pressure sensor 40 is connected in parallel between positions ③ and ④.

[0047] In a specific embodiment, a grinding and polishing air-floating spindle needs to be installed with 6 sensors, namely: 1 first pressure sensor 10, which can be an air-floating bearing air inlet pressure sensor P1; 1 second pressure sensor 20, which can be an air-floating bearing-motor cooling water inlet pressure sensor P2; 1 first differential pressure sensor 30, which can be a motor stator cooling differential pressure (integrated temperature) sensor TP1, including two pressure inlets of the motor's water inlet temperature and the motor's inlet and outlet water differential pressure; 1 second differential pressure sensor 40, which can be an air-floating bearing differential pressure (integrated temperature) sensor TP2, including two pressure inlets of the thrust bearing's water outlet temperature and the thrust bearing's inlet and outlet water differential pressure; 1 temperature sensor 50, which can be a motor stator temperature sensor PT100 and 1 photoelectric sensor 60.

[0048] Preferably, the sensor is powered by 12V or 24V, and the signal output is RS485; the electrical output uses a waterproof connector, and the double-female cable enters the power supply system at the back end; the inlet and outlet water, gas or connecting pipe interfaces are all PC8 connectors and plastic hoses, and the insertion direction is a horizontal insertion structure from the outside to the inside. All sensors can adapt to splashproof or high-humidity environments, and are connected into a whole with a transfer structure plate and a pipe. At the same time, except for the stator temperature sensor and the photoelectric sensor, which do not need to pass through the water and gas path, these two sensors are not integrated in the module, and the remaining 4 sensor functions are designed as an integrated unit.

[0049] The above monitoring system for the grinding and polishing air-floating spindle adopts a modular integrated sensing system to monitor the rotational speed change, stator temperature change, intake air pressure, cooling water pressure, motor cooling water temperature and differential pressure change, and the inlet and outlet water temperature and differential pressure change of the thrust bearing, etc. during the operation of the spindle in real time and accurately. It can give timely feedback when the air supply pressure changes, the water supply pressure changes, or the spindle operates abnormally, and can accurately monitor whether the factory conditions of the spindle operation can meet the normal working standards, providing a guarantee for the stable operation of the spindle.

[0050] The present invention also provides a monitoring method for the grinding and polishing air-floating spindle. This monitoring method applies the above monitoring system. Since the cooling system of the grinding and polishing air-floating spindle consists of two parts, first cooling the bearing assembly and then entering the motor stator sleeve to cool the motor stator, this monitoring method includes using the sensors of the sensor acquisition module to respectively collect data on the rotational speed of the spindle motor, the temperature of the motor stator, the air pressure at the intake end of the air bearing, the water pressure at the inlet of the motor cooling water, the differential pressure and temperature of the motor cooling water inlet and outlet, and the differential pressure and temperature of the thrust bearing cooling water, and transmitting the signals to the monitoring and control module, so as to monitor the temperature difference and differential pressure before and after the cooling of the grinding and polishing air-floating spindle.

[0051] Further, the compressed air entering the grinding and polishing air-floating spindle is first connected to the corresponding interface of the monitoring system, and after the air pressure is monitored to meet the standard, it is then connected into the grinding and polishing air-floating spindle.

[0052] Further, both the motor cooling water and the thrust cooling water are passed into the monitoring system before entering the spindle. The water temperature and water pressure are detected first, and the cooling water after passing through the cooling cycle is passed into the monitoring system again, so as to monitor and obtain the temperature difference and differential pressure before and after the cooling of the grinding and polishing air-floating spindle.

[0053] The above embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A monitoring system for a grinding and polishing air-floating spindle, characterized in that, The monitoring system at least includes a sensor acquisition module, a spindle system, a power supply system, and a monitoring and control module. The sensor acquisition module is arranged on the spindle system, and the sensor acquisition module is electrically connected to the spindle system through the power supply system; Among them, the sensor acquisition module includes multiple sensors. The multiple sensors acquire the temperature difference and / or pressure difference data of the spindle system and transmit signals to the monitoring and control module.

2. The monitoring system according to claim 1, wherein The sensor acquisition module at least includes a first pressure sensor (10), a second pressure sensor (20), a first differential pressure sensor (30), a second differential pressure sensor (40), a temperature sensor (50), and a photoelectric sensor (60); the temperature sensor (50) and the photoelectric sensor (60) are separately installed on the spindle system, and the first pressure sensor (10), the second pressure sensor (20), the first differential pressure sensor (30), and the second differential pressure sensor (40) are integrally integrated in the sensor acquisition module.

3. The monitoring system according to claim 2, characterized in that, The first pressure sensor (10) is connected to the air bearing intake pipeline (1), and the air bearing intake pipeline (1) is an independent pipeline.

4. The monitoring system according to claim 3, characterized in that, The second pressure sensor (20) is arranged on the motor cooling water inlet and outlet pipeline (2), and the motor cooling water inlet and outlet pipeline (2) is also connected to one end of the high-pressure side of the first differential pressure sensor (30). One end of the low-pressure side of the first differential pressure sensor (30) is connected to the parallel motor inlet and outlet pipeline (3), and the parallel motor inlet and outlet pipeline (3) is also connected to one end of the high-pressure side of the second differential pressure sensor (40). One end of the low-pressure side of the second differential pressure sensor (40) is connected to the air bearing cooling water inlet and outlet pipeline (4).

5. The monitoring system according to claim 4, characterized in that, The motor cooling water inlet and outlet pipeline (2) and the parallel motor inlet and outlet pipeline (3) are also respectively connected to the temperature sensor (50).

6. The monitoring system according to claim 5, characterized in that, The second pressure sensor (20), the first differential pressure sensor (30), and the second differential pressure sensor (40) are in a series relationship for data acquisition in sequence.

7. The monitoring system according to claim 6, characterized in that, The air bearing intake pipeline (1), the motor cooling water inlet and outlet pipeline (2), the parallel motor inlet and outlet pipeline (3), and the air bearing cooling water inlet and outlet pipeline (4) are all introduced into the sensor acquisition module through pipe joints, and the sensors integrally integrated in the sensor acquisition module are all connected into a whole using an adapter structure plate and pipelines.

8. A monitoring method for a monitoring system of the abrasive polishing air-floating spindle according to any one of claims 1-7, characterized in that, The monitoring method includes: the sensors of the sensor acquisition module respectively acquire data on the spindle motor speed, motor stator temperature, air bearing intake end air pressure, motor cooling water inlet water pressure, motor cooling water inlet and outlet water pressure difference and water temperature, and bearing thrust cooling water pressure difference and water temperature of the grinding and polishing air floating spindle, and transmit signals to the monitoring and control module to monitor the temperature difference and pressure difference before and after cooling of the grinding and polishing air floating spindle.

9. The monitoring method according to claim 8, characterized in that, The compressed air entering the grinding and polishing air floating spindle is first connected to the corresponding interface of the monitoring system, and after the air pressure is monitored and meets the standard, it is then connected into the grinding and polishing air floating spindle.

10. The monitoring method according to claim 9, characterized in that, Before the motor cooling water and the bearing thrust cooling water enter, they are both passed into the monitoring system to detect the water temperature and water pressure once. Then, the cooling water that has undergone the cooling cycle is passed into the monitoring system again, so as to monitor and obtain the temperature difference and pressure difference before and after the cooling of the polishing and air-floating spindle.

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