A wafer CMP anomaly detection system

Abstract

The present invention discloses a wafer CMP anomaly detection system, which relates to the technical field of wafer processing and includes a current detection unit, an overload trigger unit, and a shutdown alarm unit; Current detection unit: used to detect the change in the current of the polishing head drive motor to determine whether it is overloaded; Overload trigger unit: when the current detection unit detects that the polishing head drive motor is overloaded, the overload trigger unit is activated to trigger the shutdown alarm unit to give a shutdown alarm. This system detects the load of the polishing head motor (the current is proportional to the load) through the current detection unit. When it detects that it is overloaded, the overload trigger unit is activated to control the polishing equipment to stop the polishing operation and control the alarm unit to give an alarm. Since this detection system monitors the load of the polishing head drive motor, there will be no situation where the debris is small and the flying chip position is not in the Sensor sensing area, resulting in inability to detect, nor will there be an anomaly of false alarm due to the sensor being wetted with water, improving its detection accuracy and reducing its alarm error rate.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and particularly relates to a wafer CMP anomaly detection system. Background Art

[0002] With the development of integrated circuits, semiconductor factories have an increasing demand for test wafers. To save costs, the test wafer regeneration project has emerged as the times require. The regeneration project is to perform a certain surface treatment on these test wafers so that they can be restored to the state at the beginning of commissioning for reuse. Since for 12-inch Si wafers, customers have relatively high requirements for the particles on the wafer surface, generally CMP processing is required to achieve the processing requirements of high flatness and low particles.

[0003] In the prior art, a light sensor at a fixed position above the CMP is used to detect whether there is debris or flying chips. If the debris is small or the flying chips are not in the detection position of the sensor, the sensor will not alarm, that is, the detection accuracy is low, resulting in greater equipment or product losses; if water splashes on the sensor during the CMP processing, false alarms are very likely to occur, that is, the alarm error rate is high.

[0004] Based on this, this application document proposes a brand-new detection system. By detecting the load condition of the polishing head motor, once anomalies such as debris, flying chips, and film residues occur, the motor load will increase sharply, triggering an abnormal alarm and shutdown. Summary of the Invention

[0005] The purpose of this application is to provide a wafer CMP anomaly detection system to solve the problems of low detection accuracy and high alarm error rate of the existing detection system.

[0006] To achieve the above purpose, this application provides the following technical solution: A wafer CMP anomaly detection system includes a current detection unit, an overload trigger unit, and a shutdown alarm unit;

[0007] Current detection unit: It is used to detect the current change of the polishing head drive motor to determine whether it is overloaded;

[0008] Overload trigger unit: When the current detection unit detects that the polishing head drive motor is overloaded, the overload trigger unit is activated to trigger the shutdown alarm unit;

[0009] Shutdown alarm unit: It is used to control the polishing equipment to stop the polishing operation and control the alarm unit to give an alarm.

[0010] Preferably, the detection unit includes an analog ammeter with a rotating pointer inside;

[0011] The overload trigger unit includes a conductive column installed in the inner cavity of the pointer ammeter through an insulating block and an insulating groove fixed to the upper end of the rotating pointer. A first elastic conductive member is fixed to the side end of the insulating groove. A conductive joint is installed on the insulating groove. It further includes a trigger assembly and an external power source. The trigger assembly includes a mounting frame composed of a top plate, a bottom plate, and several columns. The top plate and the bottom plate are respectively fixed to the upper and lower ends of the several columns. A lower pressure plate is slidably arranged on the columns. A magnet is fixed to the lower pressure plate. An electromagnet is installed at the lower end of the top plate. When the electromagnet is energized, the magnetic pole at the lower end is the same as that of the magnet. The first elastic conductive member, the conductive joint, the electromagnet, the external power source, and the conductive column are electrically connected in sequence;

[0012] The shutdown alarm unit includes a shutdown push switch and an alarm push switch located below the lower pressure plate. The shutdown push switch is electrically connected to the polishing equipment. The alarm push switch is electrically connected to the alarm.

[0013] It further includes a second elastic conductive member, a conductive sheet, and an elastic conductive pull cord arranged in the insulating groove. Both ends of the elastic conductive pull cord are respectively connected to the conductive sheet and the conductive joint. Both ends of the conductive sheet are slidably arranged in sliding grooves provided on the inner wall of the insulating groove. The second elastic conductive member is electrically connected to the first elastic conductive member.

[0014] Preferably, it further includes a second elastic conductive member, a conductive sheet, and an elastic conductive pull cord arranged in the insulating groove. Both ends of the elastic conductive pull cord are respectively connected to the conductive sheet and the conductive joint. Both ends of the conductive sheet are slidably arranged in sliding grooves provided on the inner wall of the insulating groove. The second elastic conductive member is electrically connected to the first elastic conductive member.

[0015] Preferably, it further includes a worm gear ring and a worm. The insulating block is installed on the worm gear ring. The worm is rotatably arranged in the inner cavity of the pointer ammeter and is connected to the worm gear ring. One end of the worm penetrates through the pointer ammeter and is fixedly connected to a rotating block. The axis of the worm gear ring and the axis of the rotating shaft connected to the rotating pointer are on the same vertical line. The worm gear ring is movably installed in the inner cavity of the pointer ammeter through a mounting block.

[0016] Preferably, the worm gear ring includes two semi-ring bodies, and semi-arc grooves are provided on both semi-ring bodies. The mounting block includes two semi-fixed plates. Through cavities for accommodating the rotating shaft are provided at the axes of the two semi-fixed plates. The two semi-fixed plates are fixedly connected to the pointer ammeter by screws. Arc-shaped insertion strips adapted to the semi-arc grooves are fixed to the lower ends of the two semi-fixed plates.

[0017] Preferably, an annular groove is provided on the worm gear ring, the insulating block is slidably arranged in the annular groove, a baffle is fixed in the annular groove, and a buffer spring is connected between the baffle and the insulating block.

[0018] Preferably, a blocking ring is fixedly sleeved on the column, and an elastic cushion ring is fixed above the blocking ring.

[0019] In summary, the technical effects and advantages of the present invention are as follows:

[0020] The structure of the present invention is reasonable. The system detects the load (the current is proportional to the load) of the polishing head motor through the current detection unit. When it detects overload, the overload trigger unit is activated to control the polishing equipment to stop the polishing operation and control the alarm unit to give an alarm. Since this detection system monitors the load of the polishing head drive motor, there will be no situation where the fragments are small and the flying piece position is not in the Sensor sensing area, resulting in inability to detect, nor will there be an abnormal situation of false alarm due to the sensor getting wet, improving its detection accuracy and reducing its alarm error rate;

[0021] In the present invention, a centrifugal mechanism is added to avoid the situation of false alarm caused by the slow rotation of the rotating pointer and contact with the conductive column due to other reasons, enhancing the pertinence of the system to alarm for abnormal situations such as fragments, flying pieces, and film residues;

[0022] In the present invention, it also includes a worm gear ring and a worm. The worm gear ring can be rotated by rotating the worm, and the position of the conductive column on it can be changed by the rotating worm gear ring, and the position of the conductive column can be adjusted as needed;

[0023] In the present invention, the insulating block is slidably arranged in the annular groove on the worm gear ring, and a buffer spring is also provided to buffer the collision between the conductive column and the insulating groove, reducing the damage to each component caused by the collision. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a three-dimensional structure schematic diagram of the present invention;

[0026] Figure 2 It is an internal structure schematic diagram of the pointer type ammeter of the present invention;

[0027] Figure 3 For the present invention Figure 2Schematic diagram of the partial disassembly structure of the middle needle-type ammeter;

[0028] Figure 4 This is the present invention Figure 3 Schematic diagram of the structure of the mounting block in the present invention;

[0029] Figure 5 This is the present invention Figure 2 Schematic diagram of the structure of the worm gear ring in the present invention;

[0030] Figure 6 This is the present invention Figure 5 Schematic diagram of the enlarged structure at position A in the present invention;

[0031] Figure 7 This is the present invention Figure 2 Schematic diagram of the structure of the rotating pointer in the present invention;

[0032] Figure 8 This is the present invention Figure 1 Front view schematic diagram of the trigger assembly in the present invention.

[0033] In the figure: 1. Base; 2. Pointer ammeter; 21. Rotating pointer; 22. Conductive column; 23. Rotating block; 24. Worm; 25. Mounting block; 251. Semi-fixed plate; 252. Through cavity; 253. Arc-shaped insert; 26. Worm gear ring; 261. Semi-ring body; 262. Semi-arc-shaped groove; 263. Ring-shaped groove; 27. Insulating groove; 28. Elastic conductive pull rope; 29. Second elastic conductive member; 210. First elastic conductive member; 211. Conductive sheet; 212. Slide groove; 213. Conductive joint; 214. Buffer spring; 215. Baffle; 216. Insulating block; 3. Trigger assembly; 31. Mounting frame; 32. Column; 33. Electromagnet; 34. Magnet; 35. Alarm push switch; 36. Stop push switch; 37. Lower pressing plate; 38. Blocking ring; 39. Elastic gasket ring; 4. Alarm; 5. Wire outlet hole. Embodiment

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Example: Refer to Figure 1A wafer CMP anomaly detection system as shown includes a current detection unit, an overload trigger unit, and a shutdown alarm unit; Current detection unit: It is used to detect the change in the current of the polishing head drive motor to determine whether it is overloaded; Overload trigger unit: When the current detection unit detects that the polishing head drive motor is overloaded, the overload trigger unit is activated to trigger the shutdown alarm unit; Shutdown alarm unit: It is used to control the polishing equipment to stop the polishing operation and control the alarm unit to give an alarm.

[0036] This system detects the load of the polishing head motor (the current is proportional to the load) through the current detection unit. When it detects overload, the overload trigger unit is activated to control the polishing equipment to stop the polishing operation and control the alarm unit to give an alarm. Since this detection system monitors the load of the polishing head drive motor, there will be no situation where the debris is small and the flying chip position is not in the Sensor sensing area, resulting in inability to detect, nor will there be an abnormal situation of false alarm due to the sensor getting wet, improving its detection accuracy and reducing its alarm error rate.

[0037] As a preferred implementation manner in this embodiment, as Figure 1-8 shown, the detection unit includes an analog ammeter 2 with a rotating pointer 21 arranged inside; the overload trigger unit includes a conductive column 22 installed in the inner cavity of the analog ammeter 2 through an insulating block 216 and an insulating groove 27 fixed to the upper end of the rotating pointer 21. A first elastic conductive member 210 is fixed to the side end of the insulating groove 27, and a conductive joint 213 is installed on the insulating groove 27. It also includes a trigger assembly 3 and an external power supply. The trigger assembly 3 includes a mounting frame 31 composed of a top plate, a bottom plate, and several columns 32. The top plate and the bottom plate are respectively fixed to the upper and lower ends of several columns 32. A lower pressing plate 37 is slidably arranged on the columns 32. A magnet 34 is fixed to the lower pressing plate 37. An electromagnet 33 is installed at the lower end of the top plate, and when the electromagnet 33 is energized, the magnetic pole at its lower end is the same as the magnetic pole of the magnet 34. The first elastic conductive member 210, the conductive joint 213, the electromagnet 33, the external power supply, and the conductive column 22 are electrically connected in sequence; the shutdown alarm unit includes a shutdown push switch 36 and an alarm push switch 35 located below the lower pressing plate 37. The shutdown push switch 36 is electrically connected to the polishing equipment, and the alarm push switch 35 is electrically connected to the alarm 4.

[0038] When the polishing head drive motor is performing normal polishing operations, the current passing through it is constant. When abnormalities such as debris, flying chips, and film residues occur, since the load on the polishing head motor will increase sharply at this time, and as the load on the polishing head motor increases, its internal current will also increase rapidly (the current is proportional to the load). Therefore, this document uses the method of detecting current to determine whether it is overloaded. The conductive column 22 is set at the current range position when it is overloaded. When the polishing head drive motor is overloaded, its rotating pointer 21 will rotate. The contact between the first elastic conductive member 210 and the conductive column 22 causes the circuit of the electromagnet 38 to be connected. The electromagnet 38 is energized, and according to the principle of like poles repelling each other, the magnet 34 drives the lower pressing plate 37 to move downward and press the stop pressing switch 36 and the alarm pressing switch 35 to perform the stop and alarm operations of the polishing equipment. Compared with the traditional light sensor detection method, this detection system has higher detection accuracy (even small debris can trigger an alarm) and a lower alarm error rate (less likely to have false alarms).

[0039] It should be noted that, first, the pointer type ammeter 2 is provided with an outlet hole 5 for connecting wires to facilitate wire outlet; second, the lower pressing plate 37 forms a squeeze on the pressing switch through the magnetic force and its own and the gravity of the magnet 34. When the electromagnet 33 is powered off, the magnetic force generated between the magnet 34 and the electromagnet 33 at this time is less than the sum of the gravity of the lower pressing plate 37 and the magnet 34, that is, the magnet 34 cannot move upward and return to its original position through the magnetic force, preventing the insulating box 27 from colliding with the conductive column 22 and causing the rotating pointer 21 to swing back and forth and collide with the conductive column 22 twice or multiple times, resulting in multiple on-off operations of the electromagnet 33 and avoiding affecting the service life of the electromagnet 33. The magnet 34 needs to be manually reset, that is, the upper end of the magnet 34 contacts the lower end of the electromagnet 33 to form a magnetic adsorption fixation; third, while the first elastic conductive member 210 has electrical conductivity, it has a good buffering effect, which can prevent the insulating groove 27 from colliding violently with the conductive column 22 and causing component damage; fourth, the pointer type ammeter 2 and the mounting bracket 21 are both mounted on the base 1.

[0040] As a preferred implementation manner in this embodiment, as Figure 7As shown, it further includes a second elastic conductive member 29, a conductive sheet 211, and an elastic conductive pull cord 28 disposed in the insulating groove 27. Both ends of the elastic conductive pull cord 28 are respectively connected to the conductive sheet 211 and the conductive joint 213. Both ends of the conductive sheet 211 are slidably disposed in the sliding grooves 212 provided on the inner wall of the insulating groove 27. The second elastic conductive member 29 is electrically connected to the first elastic conductive member 210. When abnormalities such as debris, flying chips, and film residues occur, the load and internal current of the polishing head motor will increase sharply. The sharply increased current will cause the rotary pointer 21 to rotate rapidly. The conductive sheet 211 therein will move the elastic conductive pull cord 28 under the action of centrifugal force. The conductive sheet 211 will contact the second elastic conductive member 29. At this time, when the first elastic conductive member 210 contacts the conductive column 211, the circuit of the electromagnet 33 will be turned on. When the centrifugal force becomes smaller, the conductive sheet 211 will return to its original position under the elastic force of the elastic conductive pull cord 28. An additional centrifugal mechanism is provided to avoid the situation of false alarms caused by the low-speed rotation of the rotary pointer 21 and contact with the conductive column 22 due to other reasons, making the alarm of the system for abnormalities such as debris, flying chips, and film residues more targeted.

[0041] It should be noted that the second elastic conductive member 29, the first elastic conductive member 210, and the elastic conductive pull cord 28 can be made of conductive rubber material.

[0042] As a preferred implementation manner in this embodiment, as Figure 2 、 Figure 5 and Figure 6 shown, it further includes a worm gear ring 26 and a worm 24. The insulating block 216 is installed on the worm gear ring 26. The worm 24 is rotatably disposed in the inner cavity of the pointer type ammeter 2 and is connected to the worm gear ring 26. One end of the worm 24 penetrates through the pointer type ammeter 2 and is fixedly connected to the rotating block 23. The axis of the worm gear ring 26 and the axis of the rotating shaft connected to the rotary pointer 21 are on the same vertical line. The worm gear ring 26 is movably installed in the inner cavity of the pointer type ammeter 2 through the mounting block 25. During use, the position of the conductive column 22 can be adjusted as needed. The worm 24 can be rotated to drive the worm gear ring 26 to rotate, and the position of the conductive column 22 thereon can be changed by the rotating worm gear ring 26.

[0043] It should be noted that the worm gear ring 26 and the worm 24 have a self-locking function, which is beneficial to the stability of the worm gear ring 26.

[0044] As a preferred implementation manner in this embodiment, as Figure 4 and Figure 5As shown, the worm gear ring 26 includes two semi-ring bodies 261, and semi-arc grooves 262 are provided on both of the two semi-ring bodies 261. The mounting block 25 includes two semi-fixed plates 251. Through cavities 252 for accommodating the rotating shaft are provided at the axles of the two semi-fixed plates 251. The two semi-fixed plates 251 are fixedly connected to the pointer ammeter 2 by screws. Arc-shaped insertion strips 253 adapted to the semi-arc grooves 262 are fixed at the lower ends of the two semi-fixed plates 251. The worm gear ring 26 and the mounting block 25 are both split in half, which facilitates the installation of the worm gear ring 26 and the mounting block 25 around the rotating shaft. The arc-shaped insertion strips 253 provided thereon are inserted into the semi-arc grooves 262 to limit the worm gear ring 26 without affecting the rotation of the worm gear ring 26.

[0045] As a preferred implementation mode in this embodiment, as Figure 5 and Figure 6 shown, an annular groove 263 is provided on the worm gear ring 26. The insulating block 216 is slidably arranged in the annular groove 263. A baffle 215 is fixed in the annular groove 263, and a buffer spring 214 is connected between the baffle 215 and the insulating block 216. The setting of the buffer spring 214 further buffers the collision between the conductive column 22 and the insulating groove 27, and further reduces the damage to each component caused by the collision.

[0046] It should be noted that, first, an arc-shaped slider 6 is fixed on one side end of the insulating block 216, and the end of the arc-shaped slider 6 is slidably arranged in an annular chute provided on the inner cavity wall of the annular groove 263, which can ensure the stable circular motion of the insulating block 26; second, the outer shape of the insulating block 216 is adapted to the annular groove 263.

[0047] As a preferred implementation mode in this embodiment, as Figure 8 shown, a blocking ring 38 is fixedly sleeved on the column 32, and an elastic cushion ring 39 is fixed above the blocking ring 38. The blocking ring 33 is used to bear the weights of the lower pressing plate 37 and the magnet 34, preventing the lower pressing plate 37 from excessively squeezing the two pressing switches. The elastic cushion ring 39 provided thereon can buffer the collision.

[0048] The working principle of this utility model: When the polishing head driving motor is performing normal polishing operations, the current passing through it is constant. When abnormalities such as debris, flying chips, and film residues occur, since the load of the polishing head motor will increase sharply at this time, and as the load of the polishing head motor increases, its internal current will also increase rapidly (the current is proportional to the load). Therefore, this document uses the method of detecting current to determine whether it is overloaded. The conductive column 22 is set at the current range position when it is overloaded. When the polishing head driving motor is overloaded, its rotating pointer 21 will rotate. Through the contact between the first elastic conductive member 210 and the conductive column 22, the circuit of the electromagnet 38 is connected. The electromagnet 38 is energized, and according to the principle of like poles repelling each other, the magnet 34 drives the lower pressing plate 37 to move downward and press the stop pressing switch 36 and the alarm pressing switch 35 to perform the stop and alarm operations of the polishing equipment. Since this detection system monitors the load condition of the polishing head driving motor, there will be no situation where small debris or flying chips are not in the Sensor sensing area and cannot be detected, nor will there be an abnormal situation of false alarms due to the sensor getting wet, improving its detection accuracy and reducing its alarm error rate;

[0049] An additional centrifugal mechanism is added to avoid the situation of false alarms caused by the slow rotation of the rotating pointer 21 and contact with the conductive column 22 due to other reasons, making the alarm of this system more targeted for abnormalities such as debris, flying chips, and film residues;

[0050] It also includes a worm gear ring 26 and a worm 24. During use, the position of the conductive column 22 can be adjusted as needed. The worm 24 can be rotated to drive the worm gear ring 26 to rotate, and the position of the conductive column 22 on it can be changed by the rotating worm gear ring 26;

[0051] The worm gear ring 26 is provided with an annular groove 263. The insulating block 216 is slidably arranged in the annular groove 263, and it is also provided with a buffer spring 214, which buffers the collision between the conductive column 22 and the insulating groove 27 and reduces the damage to each component caused by the collision.

[0052] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wafer CMP anomaly detection system, characterized in that: It includes a current detection unit, an overload trigger unit and a shutdown alarm unit; Current detection unit: It is used to detect the current change of the polishing head drive motor to determine whether it is overloaded; Overload trigger unit: When the current detection unit detects that the polishing head drive motor is overloaded, the overload trigger unit is activated to trigger the shutdown alarm unit; Shutdown alarm unit: It is used to control the polishing equipment to stop the polishing operation and control the alarm unit to give an alarm; The current detection unit includes a pointer ammeter (2) with a rotating pointer (21) arranged inside; The overload trigger unit includes a conductive column (22) installed in the inner cavity of the pointer ammeter (2) through an insulating block (216) and an insulating groove (27) fixed to the upper end of the rotating pointer (21). A first elastic conductive member (210) is fixed to the side end of the insulating groove (27). A conductive joint (213) is installed on the insulating groove (27). It also includes a trigger assembly (3) and an external power supply. The trigger assembly (3) includes a mounting bracket (31) composed of a top plate, a bottom plate and several columns (32). The top plate and the bottom plate are respectively fixed to the upper and lower ends of several columns (32). A lower pressing plate (37) is slidably arranged on the columns (32). A magnet (34) is fixed to the lower pressing plate (37). An electromagnet (33) is installed at the lower end of the top plate. When the electromagnet (33) is energized, the magnetic pole at the lower end is the same as the magnetic pole of the magnet (34). The first elastic conductive member (210), the conductive joint (213), the electromagnet (33), the external power supply and the conductive column (22) are electrically connected in sequence; The shutdown alarm unit includes a shutdown push switch (36) and an alarm push switch (35) located below the lower pressing plate (37). The shutdown push switch (36) is electrically connected to the polishing equipment. The alarm push switch (35) is electrically connected to the alarm (4).

2. The wafer CMP anomaly detection system according to claim 1, wherein: It also includes a second elastic conductive member (29), a conductive sheet (211) and an elastic conductive pull cord (28) arranged in the insulating groove (27). The two ends of the elastic conductive pull cord (28) are respectively connected to the conductive sheet (211) and the conductive joint (213). The two ends of the conductive sheet (211) are slidably arranged in a chute (212) provided on the inner wall of the insulating groove (27). The second elastic conductive member (29) is electrically connected to the first elastic conductive member (210).

3. The wafer CMP anomaly detection system according to claim 1, wherein: It also includes a worm gear ring (26) and a worm (24). The insulating block (216) is installed on the worm gear ring (26). The worm (24) is rotatably arranged in the inner cavity of the pointer ammeter (2) and is connected to the worm gear ring (26). One end of the worm (24) penetrates through the pointer ammeter (2) and is fixedly connected to a rotating block (23). The axis of the worm gear ring (26) and the axis of the rotating shaft connected to the rotating pointer (21) are on the same vertical line. The worm gear ring (26) is movably installed in the inner cavity of the pointer ammeter (2) through a mounting block (25).

4. The wafer CMP anomaly detection system according to claim 3, wherein: The worm gear ring (26) includes two semi-ring bodies (261), and semi-arc grooves (262) are provided on both of the two semi-ring bodies (261). The mounting block (25) includes two semi-fixed plates (251). Through cavities (252) for accommodating the rotating shaft are provided at the axles of the two semi-fixed plates (251). The two semi-fixed plates (251) are fixedly connected to the pointer ammeter (2) by screws. Arc-shaped insertion strips (253) adapted to the semi-arc grooves (262) are fixed at the lower ends of the two semi-fixed plates (251).

5. The wafer CMP anomaly detection system according to claim 3, wherein: A circular groove (263) is provided on the worm gear ring (26). The insulating block (216) is slidably arranged in the circular groove (263). A baffle plate (215) is fixed in the circular groove (263), and the baffle plate (215) is connected to the insulating block (216) by a buffer spring (214).

6. The wafer CMP anomaly detection system according to claim 1, wherein: A blocking ring (38) is fixedly sleeved on the column (32), and an elastic gasket ring (39) is fixed above the blocking ring (38).

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