Wafer polishing method and apparatus, device, and storage medium

Abstract

Disclosed in the present application are a wafer polishing method and apparatus, a device, and a storage medium. The present application allows for accurate monitoring of wear of grinding wheels, has a simple and rapid operation process, and does not need other expensive specialized measurement instruments, reducing dependence on specialized devices and operators, reducing the operational complexity and measurement costs, reducing time waste caused by complicated measurement and computation processes, and solving the technical problems in the prior art of low accuracy and long time consumption during wear detection of grinding wheels.

Description

Wafer polishing method, device, equipment and storage medium

[0001] This application claims priority to the Chinese patent application No. 202411286417.9, filed on September 13, 2024, with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of automation, and in particular to a wafer polishing method, device, equipment and storage medium. BACKGROUND

[0003] Wafer polishing is a key step in the semiconductor manufacturing process. In the process of wafer polishing, the abrasive wheel is needed to remove the irregular shape and defects on the surface of the wafer, but because the abrasive wheel will be worn out during the polishing process, its surface quality and grinding ability will gradually decrease, thereby affecting the polishing effect. Therefore, accurately measuring the wear degree of the abrasive wheel is the basis for ensuring the quality of wafer polishing.

[0004] However, the traditional method of measuring the wear degree of the abrasive wheel is difficult to accurately capture the slight changes on the surface of the abrasive wheel, resulting in inaccurate measurement results of the wear degree, and at the same time, there is a problem of low efficiency of measuring the wear degree due to complex operation.

[0005] SUMMARY

[0006] Embodiments of the present application provide a wafer polishing method, device, equipment and storage medium, which solve the technical problems of low accuracy and long time consumption in the process of detecting the wear of the abrasive wheel in the prior art.

[0007] In a first aspect, embodiments of the present application provide a wafer polishing method, which is applicable to a wafer polishing device, the wafer polishing device comprising an abrasive wheel transmission shaft, an abrasive wheel and a wafer polishing platform; the abrasive wheel transmission shaft is used to drive the abrasive wheel to move up and down and horizontally; the wafer polishing platform is used to place a wafer; at least one pressure sensor is arranged on the side of the abrasive wheel opposite to its grinding surface, and the wafer polishing method comprises:

[0008] After entering a new polishing cycle, a first wafer thickness of a wafer to be polished and an updated cumulative wear amount of the abrasive wheel in the last polishing cycle are obtained, and one polishing cycle is a process of completing the polishing of one wafer to be polished;

[0009] The abrasive wheel transmission shaft is controlled to lower the abrasive wheel from a reference position to the wafer polishing platform, so that the grinding surface of the abrasive wheel is in contact with the wafer to be polished, and the sum of the pressure data of the pressure sensor is determined in real time;

[0010] stop the grinding wheel from descending and record a first distance that the grinding wheel has descended compared to the reference position when the sum of the pressure data reaches a first preset pressure;

[0011] obtain a second wafer thickness of a wafer to be polished in a previous polishing cycle and a second distance that the grinding wheel has descended recorded, and determine an amount of wear of the grinding wheel in the previous polishing cycle according to the first wafer thickness, the first distance, the second wafer thickness and the second distance;

[0012] update the cumulative amount of wear according to the amount of wear, and polish the wafer to be polished when the cumulative amount of wear is less than a preset wear threshold.

[0013] The determining of the amount of wear of the grinding wheel in the previous polishing cycle according to the first wafer thickness, the first distance, the second wafer thickness and the second distance comprises:

[0014] obtain a preset correction coefficient, the correction coefficient being used to compensate for a deviation between an actual moving distance of the grinding wheel transmission shaft and a recorded distance;

[0015] determine a first value of a sum of the first wafer thickness and the first distance, and a second value of a sum of the second wafer thickness and the second distance;

[0016] determine the amount of wear of the grinding wheel in the previous polishing cycle according to the correction coefficient, the first value and the second value.

[0017] The wafer polishing device further comprises a grinding tool platform, and the grinding tool platform is provided with a grinding tool stone; and before the grinding wheel is controlled to descend by the grinding wheel transmission shaft to make the grinding surface of the grinding wheel contact the wafer to be polished after entering a new polishing cycle, the wafer polishing device further comprises:

[0018] control the grinding wheel transmission shaft to move the grinding wheel above the grinding tool stone, control the grinding wheel transmission shaft to lower the grinding wheel to contact the grinding tool stone, and then control the grinding wheel to perform self-polishing;

[0019] control the grinding wheel transmission shaft to move the grinding wheel to the reference position when the self-polishing is completed.

[0020] The wafer polishing device further comprises a grinding tool platform, and the grinding tool platform is provided with a grinding tool stone; and before the grinding wheel is controlled to descend by the grinding wheel transmission shaft to make the grinding surface of the grinding wheel contact the wafer to be polished after entering a new polishing cycle, the wafer polishing device further comprises:

[0021] controlling the abrasive wheel driving shaft to lower the abrasive wheel from the reference position to the wafer polishing platform so that the abrasive surface of the abrasive wheel contacts the wafer polishing platform, and determining the sum of the pressure data of the pressure sensors in real time;

[0022] in a case where the sum of the pressure data reaches a first preset pressure, controlling the abrasive wheel to stop lowering and recording a third distance by which the abrasive wheel is lowered compared to the reference position at this time;

[0023] in the first polishing cycle, the cumulative wear is updated by:

[0024] updating the cumulative wear according to the third distance, a first wafer thickness corresponding to the first polishing cycle, and the first distance.

[0025] wherein the controlling the abrasive wheel driving shaft to lower the abrasive wheel from the reference position to the wafer polishing platform so that the abrasive surface of the abrasive wheel contacts the wafer to be polished comprises:

[0026] controlling the abrasive wheel driving shaft to lower the abrasive wheel from the reference position to the wafer polishing platform, and dynamically controlling the lowering speed of the abrasive wheel according to the sum of the pressure data during the lowering process.

[0027] wherein the dynamically controlling the lowering speed of the abrasive wheel according to the sum of the pressure data during the lowering process comprises:

[0028] in a case where the sum of the pressure data is zero and the position of the abrasive wheel has not reached a preset position corresponding to the current polishing cycle, the preset position being determined according to the air cutting position of the current polishing cycle, controlling the abrasive wheel to lower at a first preset speed.

[0029] in a case where the position of the abrasive wheel exceeds the preset position corresponding to the current polishing cycle, controlling the abrasive wheel to lower at a second preset speed.

[0030] in a case where the sum of the pressure data is within a preset pressure range, determining a first real-time speed in real time according to the sum of the pressure data, the first preset pressure, and the second preset speed, and controlling the abrasive wheel to lower at the first real-time speed until the sum of the pressure data reaches the first preset pressure.

[0031] wherein the determining the first real-time speed in real time according to the sum of the pressure data, the first preset pressure, and the second preset speed comprises:

[0032] determining a first difference between the first preset pressure and the sum of the pressure data, and determining a ratio of the first difference to the sum of the pressure data.

[0033] determining a product of the second preset speed and the ratio, to obtain a real-time reference speed;

[0034] determining a first real-time speed according to the real-time reference speed.

[0035] The method further includes:

[0036] when the real-time reference speed is greater than the second preset speed, determining the second preset speed as the first real-time speed;

[0037] when the real-time reference speed is less than or equal to the second preset speed and greater than or equal to a third preset speed, determining the real-time reference speed as the first real-time speed, the third preset speed being less than the second preset speed;

[0038] when the real-time reference speed is less than the third preset speed, determining the third preset speed as the first real-time speed.

[0039] In a second aspect, an embodiment of the present application provides a wafer polishing device, which is suitable for a wafer polishing equipment, the wafer polishing equipment comprising a grinding wheel transmission shaft, a grinding wheel and a wafer polishing platform; the grinding wheel transmission shaft is used to drive the grinding wheel to move up and down and horizontally; the wafer polishing platform is used to place a wafer; at least one pressure sensor is arranged on a side of the grinding wheel opposite to a grinding surface thereof; the wafer polishing device comprises:

[0040] a data acquisition module, configured to acquire a first wafer thickness of a wafer to be polished and an accumulated wear amount of the grinding wheel updated in a last polishing period after entering a new polishing period, one polishing period being a process of completing polishing of one wafer to be polished;

[0041] a grinding wheel lowering module, configured to control the grinding wheel transmission shaft to lower the grinding wheel from a reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel is in contact with the wafer to be polished, and to determine a sum of pressure data of the pressure sensor in real time;

[0042] a distance recording module, configured to control the grinding wheel to stop lowering and record a first distance by which the grinding wheel is lowered compared with the reference position when the sum of the pressure data reaches a first preset pressure;

[0043] a wear determination module configured to acquire a second wafer thickness of the wafer to be polished in a previous polishing cycle and a second distance of the recorded drop of the polishing wheel, and determine a wear amount of the polishing wheel in the previous polishing cycle according to the first wafer thickness, the first distance, the second wafer thickness and the second distance;

[0044] a wafer polishing module configured to update the cumulative wear amount according to the wear amount, and polish the wafer to be polished if the cumulative wear amount is less than a preset wear threshold.

[0045] In a third aspect, an embodiment of the present application provides a wafer polishing device, which comprises a polishing wheel transmission shaft, a polishing wheel and a wafer polishing platform; the polishing wheel transmission shaft is configured to drive the polishing wheel to move up and down and horizontally; the wafer polishing platform is configured to place a wafer; the polishing wheel is provided with at least one pressure sensor on a side opposite to a grinding surface thereof; the wafer polishing device further comprises a processor and a memory;

[0046] The memory is configured to store a computer program and transmit the computer program to the processor;

[0047] The processor is configured to execute the wafer polishing method according to the instructions in the computer program.

[0048] In a fourth aspect, an embodiment of the present application provides a storage medium storing computer executable instructions, which are configured to execute the wafer polishing method according to the first aspect when executed by a computer processor.

[0049] In the above, the embodiments of the present application provide a wafer polishing method, device, equipment and storage medium. In the embodiments of the present application, a pressure sensor is arranged on a side of the polishing wheel opposite to a grinding surface thereof, and in each polishing cycle, the polishing wheel transmission shaft is controlled to lower the polishing wheel to the wafer polishing platform, so that the grinding surface of the polishing wheel is in contact with the wafer to be polished and the sum of the pressure data received by the pressure sensor is a first preset pressure, and then the first distance of the drop of the polishing wheel is recorded. Then, the wear amount of the polishing wheel in the previous polishing cycle can be calculated according to the first distance of the current polishing cycle, the first wafer thickness of the wafer to be polished, the second distance of the drop of the polishing wheel in the previous polishing cycle and the second wafer thickness of the wafer to be polished. The embodiments of the present application can accurately monitor the wear condition of the polishing wheel, and the operation process is simple and fast, without the need for other expensive professional measuring instruments, reducing the dependence on professional equipment and operators, reducing the operation complexity and measurement cost, reducing the time waste caused by the complicated measurement and calculation process, and solving the technical problems of low accuracy and long time consumption in the process of detecting the wear condition of the polishing wheel in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0050] Fig. 1 is a schematic diagram of a wafer polishing apparatus according to an embodiment of the present application.

[0051] Fig. 2 is a flowchart of a wafer polishing method according to an embodiment of the present application.

[0052] Fig. 3 is a schematic diagram of another wafer polishing apparatus according to an embodiment of the present application.

[0053] Fig. 4 is a schematic diagram of a wafer polishing method according to an embodiment of the present application.

[0054] Fig. 5 is a schematic diagram of a control of a speed of a polishing wheel according to an embodiment of the present application.

[0055] Fig. 6 is a schematic diagram of a wafer polishing apparatus according to an embodiment of the present application.

[0056] Fig. 7 is a schematic diagram of a circuit of a wafer polishing apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0057] The following description and drawings are illustrative of specific embodiments of the application and are not intended to be limiting thereof. The embodiments are merely representative of possible variations. Individual components and functions are optional unless explicitly required, and the order of operations can be varied. Portions and features of some embodiments can be included in, or alternate, those of other embodiments. The scope of the embodiments of the application encompasses that of the claims and all available equivalents thereof. In this document, the terms "chaπacterized by," "determined by," "comprising," "comprised of," "containing," "containing of," "having," "including," "including of," "carrying," "carrying of," or grammatical variants thereof are used generally to denote that a process, method, or apparatus includes the recited elements, but not excluding others. In the description of the embodiments, like numbers refer to like elements throughout. Each embodiment is not necessarily mutually exclusive, and features of one embodiment can be combined with features of another embodiment. The embodiments are described in a progressive manner, each emphasizing a difference from the previous embodiment, and the same or similar parts are referred to each other. For the structure, product, etc. disclosed in the embodiments, since it corresponds to the part disclosed in the embodiments, the description is relatively simple, and the relevant part is referred to the method part description.

[0058] In the semiconductor manufacturing process, wafer polishing is a key step. The purpose of polishing the wafer is to remove the irregular shape and defects on the surface of the wafer, so as to obtain a surface with high flatness and low roughness, thereby improving the performance and reliability of the device. In the process of wafer polishing, the grinding wheel needs to contact the wafer and rotate to carry out the polishing process. In this process, due to the continuous wear of the grinding wheel, the grinding ability of the grinding wheel gradually decreases, thereby affecting the polishing effect. Therefore, accurately measuring the wear degree of the grinding wheel is the basis for ensuring the quality of wafer polishing.

[0059] At present, the method for measuring the wear of the grinding wheel in the prior art mainly has the following problems:

[0060] 1. Low measurement accuracy. The traditional measurement method is difficult to accurately capture the small changes on the surface of the grinding wheel, resulting in inaccurate measurement results of the wear, which affects the subsequent polishing process.

[0061] 2. Complex operation. The existing wear measurement method usually requires professional measurement equipment and complex operation steps, which not only increases the equipment cost and maintenance difficulty, but also has high requirements for the professional skills of the operator.

[0062] 3. Low wear measurement efficiency. Due to the complicated measurement and calculation process of the wear, it often takes a long time to complete.

[0063] Therefore, in order to solve the above technical problems, the wafer polishing method provided by the embodiments of the present application is provided, which is suitable for a wafer polishing device. The wafer polishing device includes a grinding wheel transmission shaft, a grinding wheel and a wafer polishing platform. The grinding wheel transmission shaft is used to drive the grinding wheel to move up and down and horizontally. The wafer polishing platform is used to place the wafer. The grinding wheel is provided with at least one pressure sensor on the side opposite to the grinding surface. The specific type of the pressure sensor can be selected according to actual needs. In one embodiment, as shown in FIG. 1, FIG. 1 is a structural schematic diagram of the wafer polishing device provided by the embodiments of the present application. The wafer polishing device includes a grinding wheel transmission shaft 1, which can move along the X axis (horizontally) or the Z axis (up and down). A pressure sensor 2, the number of which is three, is uniformly arranged on the back of the grinding wheel 3. The grinding wheel 3 is fixed to the grinding wheel transmission shaft 1. The wafer to be polished 4 is horizontally placed on the wafer polishing platform 5. The wafer polishing platform 5 is fixed on the marble platform.

[0064] As shown in FIG. 2, FIG. 2 is a flowchart of the wafer polishing method provided by the embodiments of the present application. The wafer polishing method provided by the embodiments of the present application can be executed by the wafer polishing device described above. The wafer polishing method includes:

[0065] Step 101, after entering a new polishing cycle, obtaining the first wafer thickness of the wafer to be polished and the cumulative wear amount of the polishing wheel updated in the last polishing cycle. A polishing cycle is the process of completing the polishing of a wafer to be polished.

[0066] In this embodiment, the process of completing the polishing of a wafer to be polished is regarded as a polishing cycle, that is, the process of preparing to polish a wafer to be polished to the completion of polishing. Each time a new polishing cycle is entered, the first wafer thickness of the wafer to be polished and the cumulative wear amount of the polishing wheel updated in the last polishing cycle are obtained. The cumulative wear amount is the sum of the wear amount of the polishing wheel in history. The wafer polishing equipment will store the updated cumulative wear amount after the end of each polishing cycle. In addition, the first wafer thickness of the wafer to be polished can be obtained by a thickness measuring sensor.

[0067] Step 102, control the polishing wheel driving shaft to lower the polishing wheel from the reference position to the wafer polishing platform, so that the grinding surface of the polishing wheel is in contact with the wafer to be polished, and the sum of the pressure data of the pressure sensors is determined in real time.

[0068] After obtaining the first wafer thickness of the wafer to be polished, the polishing process of the wafer to be polished can be started. Specifically, in this embodiment, the polishing wheel driving shaft is first controlled to lower the polishing wheel from the reference position to the wafer polishing platform, so that the grinding surface of the polishing wheel is in contact with the wafer to be polished. The reference position needs to be set in advance. For example, the starting position of the polishing wheel when it is not in action can be regarded as the reference position. In addition, while controlling the lowering of the polishing wheel, the sum of the pressure data of all pressure sensors is determined in real time to detect the pressure received by the polishing wheel in real time.

[0069] Step 103, in the case where the sum of the pressure data reaches a first preset pressure, control the polishing wheel to stop lowering and record the first distance by which the polishing wheel is lowered compared with the reference position.

[0070] In the process of controlling the descending of the polishing wheel, when the sum of the pressure data reaches the first preset pressure, the polishing wheel is controlled to stop descending, and a first distance that the polishing wheel has descended compared with the reference position is recorded. The first preset pressure needs to be set by the user in advance. For example, the user can measure the sum of the pressure detected by the pressure sensor when the polishing wheel contacts the wafer but has not applied too much pressure on the wafer, and set the sum of the pressure as the first preset pressure. For example, the first preset pressure can be set as 100 N. In addition, it is further needed to be explained that when there is only one pressure sensor, the sum of the pressure data is the pressure detected by the pressure sensor. In the embodiment, the first preset pressure is used as the reference for measuring the distance between the polishing wheel and the wafer to be polished. In different polishing cycles and when the material of the wafer to be polished is unchanged, when the polishing wheel contacts the wafer to be polished and the pressure on the polishing wheel is the first preset pressure, it is considered that the distance between the polishing wheel and the wafer to be polished is the same, so as to control the distance that the polishing wheel has descended in each polishing cycle. In addition, the first distance can be obtained by reading the value of the motor encoder of the polishing wheel transmission shaft.

[0071] In step 104, the second wafer thickness of the wafer to be polished in the last polishing cycle and the second distance that the polishing wheel has descended are obtained, and the wear amount of the polishing wheel in the last polishing cycle is determined according to the first wafer thickness, the first distance, the second wafer thickness and the second distance.

[0072] After the polishing wheel is controlled to stop descending, the wafer polishing device needs to obtain the second wafer thickness of the wafer to be polished in the last polishing cycle and the second distance that the polishing wheel has descended to contact the wafer to be polished and the sum of the pressure data reaches the first preset pressure.

[0073] After the second wafer thickness and the second distance in the last polishing cycle are obtained, the wear amount of the polishing wheel in the last polishing cycle can be further determined according to the first wafer thickness, the first distance, the second wafer thickness and the second distance. In one embodiment, the calculation formula of the wear amount of the polishing wheel in the last polishing cycle is as follows: n = (Z n+1 +h n+1 ) - (Z n +h n )

[0074] Wherein, L n is the wear amount, Z n+1 is the first distance, h n+1 is the first wafer thickness, Z n is the second distance, and h nis the second wafer thickness. It can be understood that, on the basis of the same distance between the polishing wheel and the wafer to be polished in each polishing cycle controlled by the first preset pressure, after the difference in wafer thickness is determined, the wear amount of the polishing wheel in the previous polishing cycle can be determined according to the distance by which the polishing wheel is lowered in the current polishing cycle compared with the previous polishing cycle.

[0075] On the basis of the above embodiment, the wear amount of the polishing wheel in the previous polishing cycle is determined according to the first wafer thickness, the first distance, the second wafer thickness, and the second distance in step 104, including:

[0076] In step 1041, a preset correction coefficient is obtained, and the correction coefficient is used to compensate for the deviation between the actual movement distance of the polishing wheel drive shaft and the recorded distance.

[0077] In one embodiment, before calculating the wear amount of the polishing wheel, a preset correction coefficient is also needed to be obtained, wherein the correction coefficient is used to compensate for the deviation between the actual movement distance of the polishing wheel drive shaft and the recorded distance. It can be understood that, due to the inevitable deviation between the numerical value of the motor encoder of the polishing wheel drive shaft and the actual movement distance of the polishing wheel, the correction coefficient is needed to correct. The correction coefficient can be obtained by measurement test in advance.

[0078] In step 1042, a first value of the sum of the first wafer thickness and the first distance, and a second value of the sum of the second wafer thickness and the second distance are determined.

[0079] In step 1043, the wear amount of the polishing wheel in the previous polishing cycle is determined according to the correction coefficient, the first value and the second value.

[0080] Finally, the wear amount of the polishing wheel in the previous polishing cycle can be determined according to the correction coefficient, the first value and the second value. The specific calculation formula is: n =k*[(Z n+1 +h n+1 )-(Z n +h n )]

[0081] Wherein, k is the correction coefficient. In this embodiment, the way of obtaining the preset correction coefficient to calculate the wear amount of the polishing wheel can further improve the accuracy of calculating the wear amount and improve the processing effect.

[0082] In step 105, the cumulative wear amount is updated according to the wear amount, and the wafer to be polished is polished in the case that the cumulative wear amount is less than the preset wear threshold.

[0083] After the wear of the polishing wheel in the last polishing cycle is determined, the accumulated wear needs to be updated, that is, the accumulated wear updated in the last polishing cycle is added with the wear of the polishing wheel in the last polishing cycle, so that the accumulated wear of the polishing wheel in the current polishing cycle is obtained. After the accumulated wear is updated, it is further determined whether the updated accumulated wear is less than the preset wear threshold. In the case of being less than the preset wear threshold, the process of polishing the wafer to be polished is continued, and the specific process of polishing can refer to the prior art, which will not be described in detail in the embodiment. In the case of not being less than the preset wear threshold, the process of polishing the wafer to be polished is stopped, and the wafer to be polished is polished again after the user replaces the polishing wheel.

[0084] In the above, the wafer polishing method provided by the embodiment of the present application includes the following steps: a pressure sensor is arranged on the side of the polishing wheel opposite to the grinding surface; in each polishing cycle, the polishing wheel driving shaft is controlled to lower the polishing wheel from the reference position to the wafer polishing platform, so that the grinding surface of the polishing wheel is in contact with the wafer to be polished and the sum of the pressure data received by the pressure sensor is a first preset pressure, and then the first distance by which the polishing wheel is lowered is recorded. Then, the wear of the polishing wheel in the last polishing cycle is calculated according to the first distance of the current polishing cycle, the first wafer thickness of the wafer to be processed, the second distance by which the polishing wheel is lowered in the last polishing cycle, and the second wafer thickness of the wafer to be processed. The embodiment of the present application can accurately monitor the wear of the polishing wheel, and the operation process is simple and fast, without the need for other expensive professional measuring instruments, reducing the dependence on professional equipment and operators, reducing the operation complexity and measurement cost, reducing the time waste caused by the complicated measurement and calculation process, and solving the technical problems of low accuracy and long time in the process of detecting the wear of the polishing wheel in the prior art.

[0085] In the actual polishing process, in each polishing cycle, self-polishing of the polishing wheel needs to be performed before the wafer to be polished is polished, so as to improve the surface quality of the polishing wheel and remove surface defects of the polishing wheel. In one embodiment, as shown in FIG. 3, FIG. 3 is a structural schematic diagram of another wafer polishing device provided by the embodiment of the present application, and the wafer polishing device further includes a grinding platform 6, and the grinding platform 6 is provided with a grinding stone 7 for grinding the polishing wheel 3. The wafer polishing method provided by the embodiment of the present application further includes the following steps after entering a new polishing cycle before the grinding surface of the polishing wheel is controlled to be in contact with the wafer to be polished by controlling the polishing wheel driving shaft to lower the polishing wheel to the wafer polishing platform:

[0086] Step 201: control the polishing wheel driving shaft to move the polishing wheel above the grinding stone, control the polishing wheel driving shaft to lower the polishing wheel to be in contact with the grinding stone, and then control the polishing wheel to perform self-polishing.

[0087] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0088] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0089] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0090] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0091] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0092] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0093] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0094] In the embodiment, when the self-polishing of the polishing wheel is controlled, the polishing wheel driving shaft is controlled to move the polishing wheel above the whetstone, then the polishing wheel driving shaft is controlled to lower the polishing wheel, and when the polishing wheel is lowered to contact the whetstone, the polishing wheel is controlled to rotate for self-polishing.

[0095] In the embodiment, after entering the first polishing cycle, the polishing wheel performs self-polishing to cause wear, and since there is no previous polishing cycle before the first polishing cycle, the amount of wear caused by the self-polishing of the polishing wheel in the first polishing cycle needs to be determined, and the amount of wear caused by the self-polishing is the updated cumulative wear in the first polishing cycle.

[0096] Specifically, after entering the first polishing cycle and before the self-polishing of the polishing wheel, the method further includes:

[0097] In step 303, the polishing wheel driving shaft is controlled to lower the polishing wheel from the reference position to the wafer polishing platform, so that the grinding surface of the polishing wheel is in contact with the wafer polishing platform, and the sum of the pressure data of the pressure sensors is determined in real time.

[0098] In the embodiment, after entering the first polishing cycle, before the self-polishing of the polishing wheel, the polishing wheel driving shaft is controlled to lower the polishing wheel from the reference position to the wafer polishing platform, so that the grinding surface of the polishing wheel is in contact with the wafer polishing platform (at this time, the wafer to be polished has not been placed), and the sum of the pressure data of the pressure sensors is determined in real time during this process.

[0099] In step 304, when the sum of the pressure data reaches the first preset pressure, the polishing wheel is controlled to stop lowering and the third distance by which the polishing wheel has been lowered from the reference position is recorded.

[0100] When it is detected that the sum of the pressure data collected by the pressure sensors reaches the first preset pressure, the polishing wheel is controlled to stop lowering, and the third distance by which the polishing wheel has been lowered from the reference position is recorded. The first preset pressure is the same as described above, and is 100 N.

[0101] In the first polishing cycle, the cumulative wear is updated by the following method:

[0102] In step 305, the cumulative wear is updated according to the third distance, the first wafer thickness corresponding to the first polishing cycle, and the first distance.

[0103] When the wafer to be polished is placed on the wafer polishing platform, the control of the abrasive wheel transmission shaft lowers the abrasive wheel from the reference position to the wafer polishing platform, so that the grinding surface of the abrasive wheel and the wafer to be polished are in contact. In addition, while controlling the lowering of the abrasive wheel, the sum of the pressure data of the pressure sensor needs to be collected in real time to detect the pressure received by the abrasive wheel in real time. During the process of controlling the lowering of the abrasive wheel, when the sum of the pressure data reaches the first preset pressure, the lowering of the abrasive wheel is stopped, and the first distance by which the abrasive wheel is lowered compared with the reference position is recorded. Then, the cumulative wear is updated according to the first distance recorded in the first polishing cycle, the first wafer thickness of the wafer to be polished, and the third distance recorded. The specific calculation formula is: L0=k*[(Z1+h1)-Z0]

[0104] Wherein, Z0 is the third distance, Z1 is the first distance corresponding to the first polishing cycle, and h1 is the first wafer thickness corresponding to the first polishing cycle.

[0105] It can be understood that in the first polishing cycle, if a new abrasive wheel is used, L0 is the cumulative wear; if an old abrasive wheel is used in the first polishing cycle, the cumulative wear data of the old abrasive wheel accumulated in the previous processing process stored in the wafer polishing equipment needs to be called, the cumulative wear data is added to L0 to update the cumulative wear, and it is determined whether the cumulative wear is less than the preset wear threshold. In one embodiment, as shown in FIG. 4, FIG. 4 is a schematic diagram of a wafer polishing method provided by an embodiment of the present application, which shows the specific process of updating the cumulative wear of the abrasive wheel in each polishing cycle.

[0106] The above, the embodiment of the present application provides a wafer polishing method, and the embodiment of the present application further considers the wear of the abrasive wheel generated by self-polishing in each polishing cycle when determining the wear of the abrasive wheel in each polishing cycle, further improves the accuracy of calculating the wear of the abrasive wheel, and the operation process is simple and fast, reduces the time waste caused by the complicated measurement and calculation process, and solves the technical problems of low accuracy and long time in the process of detecting the wear of the abrasive wheel in the prior art.

[0107] Further, in order to ensure the rapidity of the lowering of the abrasive wheel during polishing, the stability of the pressure feedback of the pressure sensor, and the safety during polishing, in one embodiment, the control of the abrasive wheel transmission shaft lowers the abrasive wheel from the reference position to the wafer polishing platform to make the grinding surface of the abrasive wheel contact the wafer to be polished, which includes:

[0108] Step 400, control the abrasive wheel transmission shaft to lower the abrasive wheel from the reference position to the wafer polishing platform, and dynamically control the lowering speed of the abrasive wheel according to the sum of the pressure data during the lowering process.

[0109] In the embodiment, the descending speed of the polishing wheel is dynamically controlled according to the sum of the pressure data collected by the pressure sensors during the control of the descending of the polishing wheel. For example, when the sum of the pressure data is 0, the polishing wheel can be controlled to descend at a faster speed to improve the polishing efficiency; and when the sum of the pressure data collected is not 0, the polishing wheel can be controlled to descend at a slower speed or at a uniform speed to ensure the safety during the polishing process.

[0110] On the basis of the above embodiment, the descending speed of the polishing wheel is dynamically controlled according to the sum of the pressure data during the descending, comprising:

[0111] In step 401, when the sum of the pressure data is 0 and the position of the polishing wheel has not reached the preset position corresponding to the current polishing cycle, the polishing wheel is controlled to descend at a first preset speed, and the preset position is determined according to the air cutting position of the current polishing cycle.

[0112] In the embodiment, the preset position corresponding to the current polishing cycle is first determined, and the preset position is determined according to the air cutting position of the current polishing cycle. Specifically, the air cutting position of the current polishing cycle can be calculated by the following formula:

[0113] wherein Z' is the air cutting position; Z0 is the third distance; h n is the wafer thickness of the wafer to be polished in the nth polishing cycle; S is the preset air cutting amount; is the updated cumulative wear amount of the nth polishing cycle.

[0114] After the air cutting position is determined, the air cutting position can be taken as the preset position corresponding to the current polishing cycle. Then, when the sum of the pressure data detected by all the pressure sensors is 0 and the position of the polishing wheel has not reached the preset position corresponding to the current polishing cycle, the polishing wheel is controlled to descend at a first preset speed, and the first preset speed can be set according to actual needs, which is not specifically limited in the embodiment.

[0115] In step 402, when the position of the polishing wheel exceeds the preset position corresponding to the current polishing cycle, the polishing wheel is controlled to descend at a second preset speed.

[0116] When the position of the polishing wheel exceeds the preset position corresponding to the current polishing cycle, the polishing wheel is controlled to descend at a second preset speed, and the second preset speed is less than the first preset speed.

[0117] In step 403, when the sum of pressure data is within the preset pressure range, a first real-time speed is determined in real time according to the sum of pressure data, the first preset pressure and the second preset speed, and the grinding wheel is controlled to descend at the first real-time speed until the sum of pressure data reaches the first preset pressure.

[0118] When the sum of pressure data is within the preset pressure range, a first real-time speed needs to be determined in real time according to the sum of pressure data, the first preset pressure and the second preset speed. In the embodiment, the preset pressure range can be set to (0, 100) N. Specifically, the first real-time speed is determined in real time according to the sum of pressure data, the first preset pressure and the second preset speed, including:

[0119] In step 4031, a first difference value between the first preset pressure and the sum of pressure data is determined, and a ratio of the first difference value to the sum of pressure data is determined.

[0120] In step 4032, a product of the second preset speed and the ratio is determined to obtain a real-time reference speed.

[0121] Specifically, the calculation formula of the real-time reference speed is:

[0122] Wherein, P set is the first preset pressure, in the example, P set = 100 N. P sum is the sum of pressure data, V ref is the real-time reference speed, and V0 is the second preset speed.

[0123] In step 4033, the first real-time speed is determined according to the real-time reference speed.

[0124] After the real-time reference speed is determined, the first real-time speed can be further determined according to the real-time reference speed. Specifically, when the real-time reference speed is greater than the second preset speed, the second preset speed is determined as the first real-time speed; when the real-time reference speed is less than or equal to the second preset speed and greater than or equal to a third preset speed, the real-time reference speed is determined as the first real-time speed, and the third preset speed is less than the second preset speed; when the real-time reference speed is less than the third preset speed, the third preset speed is determined as the first real-time speed. That is, the specific expression formula of the first real-time speed is as follows:

[0125] Wherein V1 is the first real-time speed, V2 is the third preset speed, and the third preset speed is the critical polishing speed. When the sum of the pressure data of the pressure sensor on the grinding wheel approaches 100N, the reference speed becomes smaller and smaller until it is less than V2, and the speed of the grinding wheel is changed to the critical polishing speed V2 for polishing. The specific process is shown in Figure 5, which is a schematic diagram of controlling the speed of the grinding wheel in the embodiment of the application.

[0126] In the above embodiment, the sum of the pressure data is used to dynamically control the descending speed of the grinding wheel, the multi-section speed soft landing mode is used when the grinding wheel is descending, the polishing efficiency is improved, and the stability of polishing and product quality can be ensured.

[0127] The embodiment of the application also provides a wafer polishing device, as shown in Figure 6, which is a structural schematic diagram of the wafer polishing device in the embodiment of the application. The wafer polishing device is suitable for a wafer polishing equipment, and the wafer polishing equipment includes a grinding wheel transmission shaft, a grinding wheel and a wafer polishing platform. The grinding wheel transmission shaft is used to drive the grinding wheel to move up and down and horizontally. The wafer polishing platform is used to place a wafer. At least one pressure sensor is arranged on the side of the grinding wheel opposite to the grinding surface. The wafer polishing device includes:

[0128] The data acquisition module 501 is configured to acquire the first wafer thickness of the wafer to be polished and the cumulative wear amount of the grinding wheel updated in the last polishing cycle after entering a new polishing cycle. One polishing cycle refers to the process of completing the polishing of one wafer to be polished.

[0129] The grinding wheel descending module 502 is configured to control the grinding wheel transmission shaft to lower the grinding wheel from the reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel is in contact with the wafer to be polished, and the sum of the pressure data of the pressure sensor is determined in real time.

[0130] The distance recording module 503 is configured to control the grinding wheel to stop descending and record the first distance by which the grinding wheel is lowered compared with the reference position when the sum of the pressure data reaches the first preset pressure.

[0131] The wear determining module 504 is configured to acquire the second wafer thickness of the wafer to be polished in the last polishing cycle and the second distance by which the grinding wheel is lowered, and determine the wear amount of the grinding wheel in the last polishing cycle according to the first wafer thickness, the first distance, the second wafer thickness and the second distance.

[0132] The wafer polishing module 505 is configured to update the cumulative wear amount according to the wear amount, and polish the wafer to be polished when the cumulative wear amount is less than the preset wear threshold.

[0133] On the basis of the above embodiment, the wear determining module 504 includes:

[0134] a coefficient obtaining sub-module, configured to obtain a preset correction coefficient, the correction coefficient being used to compensate for a deviation between an actual moving distance of the grinding wheel transmission shaft and the recorded distance;

[0135] a numerical value calculating sub-module, configured to determine a first numerical value of a sum of the first wafer thickness and the first distance, and a second numerical value of a sum of the second wafer thickness and the second distance;

[0136] a wear amount determining sub-module, configured to determine a wear amount of the grinding wheel in the last polishing cycle according to the correction coefficient, the first numerical value and the second numerical value.

[0137] On the basis of the above embodiment, the wafer polishing device further comprises a grinding platform, and the grinding platform is provided with a grinding stone;

[0138] a self-polishing module, configured to, after entering a new polishing cycle, control the grinding wheel transmission shaft to move the grinding wheel above the grinding stone before the grinding surface of the grinding wheel contacts the wafer to be polished, and control the grinding wheel transmission shaft to lower the grinding wheel to contact the grinding stone, and then control the grinding wheel to perform self-polishing;

[0139] a first position restoring module, configured to, in the case that the self-polishing is completed, control the grinding wheel transmission shaft to move the grinding wheel to the reference position.

[0140] On the basis of the above embodiment, the wafer polishing device further comprises a shape grinding module, configured to, before entering the first polishing cycle, control the grinding wheel transmission shaft to move the grinding wheel above the grinding stone, control the grinding wheel transmission shaft to lower the grinding wheel to contact the grinding stone, and then control the grinding wheel to perform shape grinding;

[0141] a second position restoring module, configured to, in the case that the shape grinding is completed, control the grinding wheel transmission shaft to move the grinding wheel to the reference position.

[0142] On the basis of the above embodiment, the grinding wheel lowering module 502 further comprises:

[0143] a first cycle lowering sub-module, configured to, after entering the first polishing cycle and before the self-polishing of the grinding wheel, control the grinding wheel transmission shaft to lower the grinding wheel from the reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel contacts the wafer polishing platform, and determine the sum of the pressure data of the pressure sensor in real time;

[0144] a third distance recording sub-module, configured to, in the case that the sum of the pressure data reaches a first preset pressure, control the grinding wheel to stop lowering and record a third distance by which the grinding wheel is lowered compared with the reference position;

[0145] The wear determining module 504 is further configured to, in the first polishing cycle, update the cumulative wear amount according to the third distance, the first wafer thickness corresponding to the first polishing cycle, and the first distance.

[0146] On the basis of the above-mentioned embodiments, the grinding wheel lowering module 502 is specifically configured to control the grinding wheel transmission shaft to lower the grinding wheel from the reference position to the wafer polishing platform, and dynamically control the lowering speed of the grinding wheel according to the sum of the pressure data during the lowering process.

[0147] On the basis of the above-mentioned embodiments, the grinding wheel lowering module 502 comprises:

[0148] The first speed lowering submodule is configured to control the grinding wheel to lower at a first preset speed in a case where the sum of the pressure data is zero and the position of the grinding wheel has not reached a preset position corresponding to the current polishing cycle, the preset position being determined according to the air cutting position of the current polishing cycle.

[0149] The second speed lowering submodule is configured to control the grinding wheel to lower at a second preset speed in a case where the position of the grinding wheel exceeds the preset position corresponding to the current polishing cycle.

[0150] The dynamic speed lowering submodule is configured to determine a first real-time speed in real time according to the sum of the pressure data, the first preset pressure and the second preset speed, and control the grinding wheel to lower at the first real-time speed until the sum of the pressure data reaches the first preset pressure in a case where the sum of the pressure data is within a preset pressure range.

[0151] On the basis of the above-mentioned embodiments, the dynamic speed lowering submodule is specifically configured to determine a first difference value between the first preset pressure and the sum of the pressure data, determine a ratio of the first difference value to the sum of the pressure data, determine a product of the second preset speed and the ratio to obtain a real-time reference speed, and determine the first real-time speed according to the real-time reference speed.

[0152] On the basis of the above-mentioned embodiments, the dynamic speed lowering submodule is specifically configured to determine the second preset speed as the first real-time speed in a case where the real-time reference speed is greater than the second preset speed, determine the real-time reference speed as the first real-time speed in a case where the real-time reference speed is less than or equal to the second preset speed and greater than or equal to a third preset speed, and determine the third preset speed as the first real-time speed in a case where the real-time reference speed is less than the third preset speed, the third preset speed being less than the second preset speed.

[0153] The wafer polishing device provided by the embodiments of the present application is contained in a wafer polishing apparatus and can be used to execute the wafer polishing method provided in the above-mentioned embodiments, and has the corresponding functions and beneficial effects.

[0154] It is worth noting that the above-mentioned embodiments of the wafer polishing device include various units and modules, which are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be realized; in addition, the specific names of each functional unit are only for easy mutual differentiation, and are not used to limit the protection scope of the present application.

[0155] The embodiment also provides a wafer polishing device, which comprises a grinding wheel driving shaft 1, a grinding wheel 3 and a wafer polishing platform 5; the grinding wheel driving shaft 1 is used to drive the grinding wheel 3 to move up and down and horizontally; the wafer polishing platform 5 is used to place a wafer 4; the grinding wheel 3 is provided with at least one pressure sensor 2 on the side opposite to the grinding surface thereof; the wafer polishing device further comprises a processor 8 and a memory 9; as shown in Fig. 7, Fig. 7 is a circuit principle diagram of the wafer polishing device provided in the embodiment.

[0156] The memory 9 is used to store a computer program 91 and transmit the computer program 91 to the processor 8.

[0157] The processor 8 is used to execute the steps in the above-mentioned wafer polishing method embodiment according to the instructions in the computer program 91.

[0158] For example, the computer program 91 can be divided into one or more modules / units, which are stored in the memory 9 and executed by the processor 8 to complete the present application. One or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 91 in the wafer polishing device.

[0159] The wafer polishing device can include, but is not limited to, the processor 8 and the memory 9. Those skilled in the art can understand that Fig. 7 is only an example of the wafer polishing device, and does not constitute a limitation on the wafer polishing device, and can include more or fewer components than the diagram, or combine certain components, or different components, for example, the wafer polishing device can also include an input / output device, a network access device, a bus, etc.

[0160] The processor 8 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic components, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0161] The memory 9 can be an internal storage unit of the wafer polishing apparatus, such as a hard disk or a memory of the wafer polishing apparatus. The memory 9 can also be an external storage device of the wafer polishing apparatus, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 9 can include both the internal storage unit and the external storage device of the wafer polishing apparatus. The memory 9 is used to store computer programs and other programs and data required by the wafer polishing apparatus. The memory 9 can also be used to temporarily store data that has been output or will be output.

[0162] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0163] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0164] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Part or all of the units may be selected according to actual needs to achieve the purpose of the embodiment.

[0165] In addition, the functional units in various embodiments of the application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0166] If the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the various embodiment methods of the application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various computer program storage media.

[0167] The embodiment of the application also provides a storage medium containing computer executable instructions, which are used to execute a wafer polishing method when executed by a computer processor, and the method comprises the following steps:

[0168] After entering a new polishing cycle, a first wafer thickness of a wafer to be polished and a cumulative wear amount of the grinding wheel updated in a last polishing cycle are obtained, and a polishing cycle is a process of completing polishing on one wafer to be polished.

[0169] The grinding wheel driving shaft is controlled to lower the grinding wheel from the reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel is in contact with the wafer to be polished, and the sum of the pressure data of the pressure sensor is determined in real time.

[0170] In the case that the sum of the pressure data reaches a first preset pressure, the grinding wheel is controlled to stop lowering and a first distance by which the grinding wheel is lowered compared with the reference position is recorded;

[0171] acquire a second wafer thickness of the to-be-polished wafer in a previous polishing cycle and a second distance of the recorded polishing wheel drop, and determine a wear amount of the polishing wheel in the previous polishing cycle according to the first wafer thickness, the first distance, the second wafer thickness and the second distance;

[0172] update the cumulative wear amount according to the wear amount, and polish the to-be-polished wafer in a case where the cumulative wear amount is less than a preset wear threshold.

[0173] It should be noted that the above only describes the preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the embodiments of the present application are not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the protection scope of the embodiments of the present application. Therefore, although the embodiments of the present application have been described in more detail through the above embodiments, the embodiments of the present application are not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the embodiments of the present application, and the scope of the embodiments of the present application is determined by the scope of the appended claims.

Claims

1. A wafer polishing method, the method is suitable for a wafer polishing apparatus, the wafer polishing apparatus comprises a polishing wheel driving shaft, a polishing wheel and a wafer polishing platform; the polishing wheel driving shaft is used to drive the polishing wheel to move up and down and horizontally; the wafer polishing platform is used to place a wafer; characterized in that, The grinding wheel is provided with at least one pressure sensor on the side opposite to the grinding surface, and the wafer polishing method comprises: After entering a new polishing cycle, a first wafer thickness of a wafer to be polished and an accumulated wear amount of the grinding wheel updated in a previous polishing cycle are obtained, and one polishing cycle is a process of completing polishing of one wafer to be polished; The grinding wheel driving shaft is controlled to lower the grinding wheel from a reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel is in contact with the wafer to be polished, and the sum of pressure data of the pressure sensor is determined in real time; When the sum of the pressure data reaches a first preset pressure, the grinding wheel is controlled to stop lowering and a first distance by which the grinding wheel is lowered compared with the reference position is recorded; A second wafer thickness of the wafer to be polished in the previous polishing cycle and a second distance by which the grinding wheel is lowered are obtained, and the wear amount of the grinding wheel in the previous polishing cycle is determined according to the first wafer thickness, the first distance, the second wafer thickness and the second distance; The accumulated wear amount is updated according to the wear amount, and the wafer to be polished is polished when the accumulated wear amount is less than a preset wear threshold.

2. The wafer polishing method according to claim 1, wherein The wear amount of the grinding wheel in the previous polishing cycle is determined according to the first wafer thickness, the first distance, the second wafer thickness and the second distance, which comprises: A preset correction coefficient is obtained, and the correction coefficient is used to compensate for the deviation between the actual moving distance of the grinding wheel driving shaft and the recorded distance; A first value of the sum of the first wafer thickness and the first distance is determined, and a second value of the sum of the second wafer thickness and the second distance is determined; The wear amount of the grinding wheel in the previous polishing cycle is determined according to the correction coefficient, the first value and the second value.

3. The wafer polishing method of claim 1, wherein The wafer polishing device further comprises a grinding wheel platform provided with a grinding wheel stone, and before the grinding wheel driving shaft is controlled to lower the grinding wheel to the wafer polishing platform so that the grinding surface of the grinding wheel is in contact with the wafer to be polished after entering a new polishing cycle, the method further comprises: The grinding wheel driving shaft is controlled to move the grinding wheel above the grinding wheel stone, the grinding wheel is controlled to lower to contact with the grinding wheel stone, and the grinding wheel is controlled to perform self-polishing; When the self-polishing is completed, the grinding wheel driving shaft is controlled to move the grinding wheel to the reference position.

4. The wafer polishing method according to claim 3, wherein After entering the first polishing cycle and before the grinding wheel is self-polished, the method further comprises: The grinding wheel driving shaft is controlled to lower the grinding wheel from the reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel is in contact with the wafer polishing platform, and the sum of pressure data of the pressure sensor is determined in real time; When the sum of the pressure data reaches a first preset pressure, the grinding wheel is controlled to stop lowering and a third distance by which the grinding wheel is lowered compared with the reference position is recorded; In the first polishing cycle, the accumulated wear amount is updated by the following method: According to the third distance, a first wafer thickness corresponding to a first polishing cycle, and the first distance, the cumulative wear is updated.

5. The wafer polishing method of claim 1, wherein The control of the abrasive wheel drive shaft to lower the abrasive wheel from a reference position to the wafer polishing platform to make the abrasive surface of the abrasive wheel contact the wafer to be polished comprises: The control of the abrasive wheel drive shaft to lower the abrasive wheel from a reference position to the wafer polishing platform, and the lowering speed of the abrasive wheel is dynamically controlled according to the sum of the pressure data during the lowering.

6. The wafer polishing method according to claim 5, wherein The dynamic control of the lowering speed of the abrasive wheel according to the sum of the pressure data during the lowering comprises: In the case that the sum of the pressure data is zero and the position of the abrasive wheel has not reached a preset position corresponding to the current polishing cycle, the preset position is determined according to the air cutting position of the current polishing cycle, the abrasive wheel is controlled to lower at a first preset speed; In the case that the position of the abrasive wheel exceeds the preset position corresponding to the current polishing cycle, the abrasive wheel is controlled to lower at a second preset speed; In the case that the sum of the pressure data is within a preset pressure range, a first real-time speed is determined in real time according to the sum of the pressure data, the first preset pressure, and the second preset speed, and the abrasive wheel is controlled to lower at the first real-time speed until the sum of the pressure data reaches the first preset pressure.

7. The wafer polishing method according to claim 6, wherein The determination of the first real-time speed according to the sum of the pressure data, the first preset pressure, and the second preset speed in real time comprises: Determining a first difference value of the first preset pressure and the sum of the pressure data, and determining a ratio of the first difference value to the sum of the pressure data; Determining a product of the second preset speed and the ratio to obtain a real-time reference speed; Determining a first real-time speed according to the real-time reference speed.

8. The wafer polishing method according to claim 7, wherein The determination of the first real-time speed according to the real-time reference speed comprises: In the case that the real-time reference speed is greater than the second preset speed, the second preset speed is determined as the first real-time speed; In the case that the real-time reference speed is less than or equal to the second preset speed and greater than or equal to a third preset speed, the real-time reference speed is determined as the first real-time speed, and the third preset speed is less than the second preset speed; In the case that the real-time reference speed is less than the third preset speed, the third preset speed is determined as the first real-time speed. The abrasive wheel is provided with at least one pressure sensor on the side opposite to the abrasive surface thereof, and the wafer polishing device comprises:

9. A wafer polishing apparatus, said apparatus is adapted to be used in a wafer polishing machine, said wafer polishing machine comprises a polishing wheel drive shaft, a polishing wheel and a wafer polishing platform; said polishing wheel drive shaft is used to move said polishing wheel up and down and horizontally; said wafer polishing platform is used to place a wafer; characterized in that, A data acquisition module is configured to acquire a first wafer thickness of a wafer to be polished and a cumulative wear of the abrasive wheel updated in a previous polishing cycle after entering a new polishing cycle, and one polishing cycle is a process of completing polishing of one wafer to be polished; An abrasive wheel lowering module is configured to control the abrasive wheel drive shaft to lower the abrasive wheel from a reference position to the wafer polishing platform to make the abrasive surface of the abrasive wheel contact the wafer to be polished, and to determine the sum of the pressure data of the pressure sensor in real time; ​ a distance recording module configured to control the polishing wheel to stop descending and record a first distance that the polishing wheel has descended relative to the reference position when the sum of the pressure data reaches a first preset pressure; a wear determining module configured to acquire a second wafer thickness of a wafer to be polished in a previous polishing cycle and a second distance that the polishing wheel has descended, and determine a wear amount of the polishing wheel in the previous polishing cycle according to the first wafer thickness, the first distance, the second wafer thickness, and the second distance; a wafer polishing module configured to update the cumulative wear amount according to the wear amount, and polish the wafer to be polished when the cumulative wear amount is less than a preset wear threshold.

10. A wafer polishing apparatus, the wafer polishing apparatus comprising a polishing wheel drive shaft, a polishing wheel, and a wafer polishing platform; the polishing wheel drive shaft is used to drive the polishing wheel to move up and down and horizontally; the wafer polishing platform is used to place a wafer; characterized in that, The polishing wheel is provided with at least one pressure sensor on a side opposite to a grinding surface of the polishing wheel, and the wafer polishing device further comprises a processor and a memory; The memory is configured to store a computer program and transmit the computer program to the processor; The processor is configured to execute the wafer polishing method according to instructions in the computer program.

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