Wafer polishing method, device, equipment and storage medium

Abstract

The embodiment of the present invention discloses a wafer polishing method, device, equipment and storage medium. The embodiment of the present invention sets a pressure sensor on the side of the grinding wheel opposite to its grinding surface, and in each polishing cycle, controls the grinding wheel transmission shaft to lower the grinding wheel to the wafer polishing platform, so that the grinding surface of the grinding wheel contacts the wafer to be polished and the sum of the pressure data received by the pressure sensor is a first preset pressure, and then records the first distance the grinding wheel descends. After that, the wear amount of the grinding wheel in the previous polishing cycle can be calculated according to the first distance of the current polishing cycle and the first wafer thickness of the wafer to be processed, as well as the second distance the grinding wheel descended in the previous polishing cycle and the second wafer thickness of the wafer to be processed. The embodiment of the present invention can accurately monitor the wear of the grinding wheel, and the operation process is simple and fast, which solves the technical problems of low accuracy and long time consumption in the process of detecting the wear of the grinding wheel in the prior art.

Description

Technical Field

[0001] The 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 Art

[0002] Wafer polishing is a key step in the semiconductor manufacturing process. During the wafer polishing process, the grinding wheel is needed to remove the irregular shapes and defects on the wafer surface. However, as the grinding wheel will continue to wear during the polishing process, its surface quality and grinding ability will gradually decrease, thus affecting the polishing effect. Therefore, accurately measuring the wear degree of the grinding wheel is the basis for ensuring the quality of wafer polishing.

[0003] However, the traditional method of measuring the degree of wear of the grinding wheel is difficult to accurately capture the slight changes on the surface of the grinding wheel, resulting in inaccurate measurement results of the degree of wear. At the same time, there is also the problem of low efficiency in measuring the degree of wear due to complex operation. Summary of the invention

[0004] The embodiments of the present invention 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 grinding wheel in the prior art.

[0005] In a first aspect, an embodiment of the present invention provides a wafer polishing method, which is applicable to a wafer polishing device, wherein the wafer polishing device comprises 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 provided on a side of the grinding wheel opposite to its grinding surface, and the wafer polishing method comprises:

[0006] After entering a new polishing cycle, obtaining a first wafer thickness of the wafer to be polished and the accumulated wear amount of the grinding wheel updated in the last polishing cycle, wherein one polishing cycle is a process of completing polishing of one wafer to be polished;

[0007] Controlling 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 to be polished, and determining the sum of the pressure data of the pressure sensor in real time;

[0008] When the sum of the pressure data reaches a first preset pressure, controlling the grinding wheel to stop descending and recording a first distance that the grinding wheel descends compared to the reference position at this time;

[0009] Obtaining a second wafer thickness of the wafer to be polished in a previous polishing cycle and a recorded second distance that the grinding wheel descends, and determining the wear amount 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;

[0010] 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.

[0011] Wherein, determining the wear amount 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 includes:

[0012] Obtaining a preset correction coefficient, wherein the correction coefficient is used to compensate for the deviation between the actual moving distance of the grinding wheel transmission shaft and the recorded distance;

[0013] Determining 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;

[0014] The wear amount of the grinding wheel in the last polishing cycle is determined according to the correction coefficient, the first value and the second value.

[0015] The wafer polishing device further comprises a grinding platform, on which a grindstone is arranged; after entering a new polishing cycle, before controlling the grinding wheel transmission shaft to lower the grinding wheel toward the wafer polishing platform so that the grinding surface of the grinding wheel contacts the wafer to be polished, the device further comprises:

[0016] Controlling the grinding wheel transmission shaft to move the grinding wheel to above the grindstone, controlling the grinding wheel transmission shaft to lower the grinding wheel until it contacts the grindstone, and controlling the grinding wheel to perform self-polishing;

[0017] When the self-polishing is completed, the grinding wheel transmission shaft is controlled to move the grinding wheel to the reference position.

[0018] Wherein, after entering the first polishing cycle and before the grinding wheel self-polishing, it also includes:

[0019] Controlling 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 determining the sum of the pressure data of the pressure sensor in real time;

[0020] When the sum of the pressure data reaches a first preset pressure, controlling the grinding wheel to stop descending and recording a third distance that the grinding wheel descends compared to the reference position at this time;

[0021] In the first polishing cycle, the accumulated wear amount is updated in the following manner;

[0022] The accumulated wear amount is updated according to the third distance, a first wafer thickness corresponding to the first polishing cycle, and the first distance.

[0023] The step of controlling 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 to be polished comprises:

[0024] The grinding wheel transmission shaft is controlled to lower the grinding wheel from the reference position to the wafer polishing platform, and during the lowering process, the lowering speed of the grinding wheel is dynamically controlled according to the sum of the pressure data.

[0025] The step of dynamically controlling the descending speed of the grinding wheel according to the sum of the pressure data during the descending process includes:

[0026] When 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 grinding wheel is controlled to descend at a first preset speed, wherein the preset position is determined according to the empty cutting position of the current polishing cycle;

[0027] When the position of the grinding wheel exceeds a preset position corresponding to the current polishing cycle, controlling the grinding wheel to descend at a second preset speed;

[0028] When the sum of the pressure data is within the preset pressure range, the first real-time speed is determined in real time based on the sum of the 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 the pressure data reaches the first preset pressure.

[0029] The step of determining 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 includes:

[0030] 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;

[0031] determining a product of the second preset speed and the ratio to obtain a real-time reference speed;

[0032] A first real-time speed is determined according to the real-time reference speed.

[0033] Wherein, determining the first real-time speed according to the real-time reference speed comprises:

[0034] When the real-time reference speed is greater than the second preset speed, determining the second preset speed as the first real-time speed;

[0035] In the case where the real-time reference speed is less than or equal to the second preset speed and greater than or equal to the third preset speed, determining that the real-time reference speed is the first real-time speed, and the third preset speed is less than the second preset speed;

[0036] 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.

[0037] In a second aspect, an embodiment of the present invention provides a wafer polishing device, which is applicable to a wafer polishing device, wherein the wafer polishing device comprises 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 provided on the side of the grinding wheel opposite to its grinding surface, and the wafer polishing device comprises:

[0038] A data acquisition module, used for acquiring the first wafer thickness of the wafer to be polished and the accumulated wear amount of the grinding wheel updated in the last polishing cycle after entering a new polishing cycle, wherein one polishing cycle is a process of completing polishing of one wafer to be polished;

[0039] A grinding wheel descending module, used for controlling the grinding wheel transmission shaft to descend the grinding wheel from the reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel contacts the wafer to be polished, and determining the sum of the pressure data of the pressure sensor in real time;

[0040] A distance recording module, used for controlling the grinding wheel to stop descending and recording a first distance descended by the grinding wheel compared to the reference position when the sum of the pressure data reaches a first preset pressure;

[0041] a wear determination module, used for obtaining a second wafer thickness of the wafer to be polished in a previous polishing cycle and a recorded second distance that the grinding wheel descends, and determining the wear amount 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;

[0042] The wafer polishing module is used to update the accumulated wear amount according to the wear amount, and polish the wafer to be polished when the accumulated wear amount is less than a preset wear threshold.

[0043] In a third aspect, an embodiment of the present invention provides a wafer polishing device, the wafer polishing device 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 the wafer; at least one pressure sensor is provided on the side of the grinding wheel opposite to its grinding surface, and the wafer polishing device also includes a processor and a memory;

[0044] The memory is used to store a computer program and transmit the computer program to the processor;

[0045] The processor is used to execute a wafer polishing method as described in the first aspect according to instructions in the computer program.

[0046] In a fourth aspect, an embodiment of the present invention provides a storage medium storing computer executable instructions, wherein the computer executable instructions, when executed by a computer processor, are used to execute a wafer polishing method as described in the first aspect.

[0047] As described above, the embodiment of the present invention provides a wafer polishing method, device, equipment and storage medium. In the embodiment of the present invention, a pressure sensor is arranged on the side of the grinding wheel opposite to its grinding surface, and in each polishing cycle, the grinding wheel transmission shaft is controlled to lower the grinding wheel to the wafer polishing platform, so that the grinding surface of the grinding wheel contacts the wafer to be polished and the sum of the pressure data received by the pressure sensor is the first preset pressure, and then the first distance the grinding wheel descends is recorded. After that, the wear amount of the grinding wheel in the previous polishing cycle can be calculated according to the first distance of the current polishing cycle and the first wafer thickness of the wafer to be processed, as well as the second distance of the grinding wheel descending in the previous polishing cycle and the second wafer thickness of the wafer to be processed. The embodiment of the present invention can accurately monitor the wear of the grinding wheel, and the operation process is simple and fast, without other expensive professional measuring instruments, reducing the dependence on professional equipment and operators, reducing the complexity of operation and measurement costs, reducing the time waste caused by the cumbersome measurement and calculation process, and solving the technical problems of low accuracy and long time consumption in the process of detecting the wear of the grinding wheel in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic structural diagram of a wafer polishing device provided in an embodiment of the present invention.

[0049] Figure 2 A schematic flow chart of a wafer polishing method provided in an embodiment of the present invention.

[0050] Figure 3 A schematic structural diagram of another wafer polishing device provided in an embodiment of the present invention.

[0051] Figure 4 A schematic diagram of the principle of a wafer polishing method provided by an embodiment of the present invention.

[0052] Figure 5 A schematic diagram of a method for controlling the descending speed of a grinding wheel provided in an embodiment of the present invention.

[0053] Figure 6 A schematic structural diagram of a wafer polishing device provided in an embodiment of the present invention.

[0054] Figure 7 A circuit diagram of a wafer polishing device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following description and accompanying drawings fully illustrate the specific embodiments of the present application so that those skilled in the art can practice them. The examples represent possible variations only. Unless explicitly required, separate components and functions are optional, and the order of operation can vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments. The scope of the embodiments of the present application includes the entire scope of the claims, and all available equivalents of the claims. In this article, each embodiment may be represented individually or generally by the term "invention", which is only for convenience, and if more than one invention is disclosed in fact, it is not intended to automatically limit the scope of the application to any single invention or inventive concept. In this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, without requiring or implying any actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. The various embodiments are described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other. As for the structures, products, etc. disclosed in the embodiments, since they correspond to the parts disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0056] Wafer polishing is a key step in the semiconductor manufacturing process. The purpose of wafer polishing is to remove irregular shapes and defects on the wafer surface and obtain a surface with high flatness and low roughness, thereby improving the performance and reliability of the device. During the wafer polishing process, the grinding wheel needs to contact the wafer and rotate for the polishing process. During this process, the grinding wheel will continue to wear, causing the grinding ability of the grinding wheel to gradually decrease, which in turn affects the polishing effect. Therefore, accurately measuring the wear degree of the grinding wheel is the basis for ensuring the quality of wafer polishing.

[0057] At present, the methods for measuring the wear of grinding wheels in the prior art mainly have the following problems:

[0058] 1. Low measurement accuracy. Traditional measurement methods are difficult to accurately capture tiny changes on the surface of the grinding wheel, resulting in inaccurate wear measurement results and affecting subsequent polishing processes.

[0059] Second, the operation is complicated. The existing wear measurement methods usually require professional measuring equipment and complicated operating steps, which not only increases the equipment cost and maintenance difficulty, but also places high demands on the professional skills of the operators.

[0060] 3. Wear measurement is inefficient. The wear measurement and calculation process is complicated and often takes a long time to complete.

[0061] Based on this, in order to solve the above technical problems, an embodiment of the present invention provides a wafer polishing method, which is applicable to a wafer polishing device, and 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; at least one pressure sensor is provided on the side of the grinding wheel opposite to its grinding surface, and the specific type of the pressure sensor can be selected according to actual needs. In one embodiment, if Figure 1 As shown, Figure 1 The schematic diagram of the structure of the wafer polishing equipment provided in the embodiment of the present invention is as follows, the wafer polishing equipment comprises a grinding wheel transmission shaft 1, the grinding wheel transmission shaft 1 can move along the X-axis (horizontally) or the Z-axis (up and down); a pressure sensor 2, the number of the pressure sensors 2 is three, and they are evenly arranged on the back of the grinding wheel 3; the grinding wheel 3 is fixed to the grinding wheel transmission shaft 1; the wafer 4 to be polished is horizontally placed on the wafer polishing platform 5; the wafer polishing platform 5 is fixed on the marble platform.

[0062] like Figure 2 As shown, Figure 2 The following is a flow chart of a wafer polishing method provided by an embodiment of the present invention. The wafer polishing method provided by an embodiment of the present invention can be performed by the above-mentioned wafer polishing equipment. The wafer polishing method includes:

[0063] Step 101 , after entering a new polishing cycle, obtain the first wafer thickness of the wafer to be polished and the accumulated wear amount of the grinding wheel updated in the previous polishing cycle. One polishing cycle is a process of completing polishing of one wafer to be polished.

[0064] In this embodiment, the process of polishing a wafer to be polished is regarded as a polishing cycle, that is, the process of preparing to polish a wafer to be polished until polishing is completed. Each time a new polishing cycle is entered, it is necessary to obtain the first wafer thickness of the wafer to be polished and the cumulative wear of the grinding wheel updated in the previous polishing cycle. The cumulative wear is the sum of the wear of the grinding wheel in history. After each polishing cycle, the wafer polishing equipment will store the updated cumulative wear. In addition, the first wafer thickness of the wafer to be polished can be obtained by a thickness sensor.

[0065] Step 102 , controlling 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 to be polished, and determining the sum of the pressure data of the pressure sensor in real time.

[0066] After obtaining the first wafer thickness of the wafer to be polished, the polishing process can be started on the wafer to be polished. Specifically, in this embodiment, it is first necessary to control the grinding wheel drive 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 to be polished. The reference position needs to be set in advance. For example, the starting position of the grinding wheel before it moves can be used as the reference position. In addition, while controlling the grinding wheel to descend, it is necessary to determine the sum of the pressure data of all pressure sensors in real time to detect the pressure on the grinding wheel in real time.

[0067] Step 103: When the sum of the pressure data reaches a first preset pressure, the grinding wheel is controlled to stop descending and a first distance that the grinding wheel descends compared to the reference position is recorded.

[0068] In the process of controlling the grinding wheel to descend, when it is detected that the sum of the pressure data reaches the first preset pressure, the grinding wheel is controlled to stop descending, and the first distance that the grinding wheel descends compared to the reference position is recorded at the same time. Among them, the first preset pressure needs to be set by the user in advance. For example, the user can pre-measure the sum of the pressures detected by the pressure sensor when the grinding wheel is in contact with the wafer but has not applied too much pressure to the wafer, and set the sum of the pressures to the first preset pressure. For example, the first preset pressure can be set to 100N. In addition, it is also necessary to further explain that when there is only one pressure sensor, the sum of the pressure data is the pressure detected by one pressure sensor. In this embodiment, the first preset pressure is used as a reference for measuring the distance between the grinding wheel and the wafer to be polished. In different polishing cycles and when the material of the wafer to be polished remains unchanged, when the grinding wheel is in contact with the wafer to be polished and the pressure on the grinding wheel is the first preset pressure, it can be considered that the distance between the grinding wheel and the wafer to be polished is the same, so as to control the distance that the grinding wheel descends in each polishing cycle. In addition, the first distance can be obtained by reading the value of the motor encoder of the grinding wheel transmission shaft.

[0069] Step 104, obtaining the second wafer thickness of the wafer to be polished and the recorded second distance of the grinding wheel descending in the previous polishing cycle, and determining the wear amount 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.

[0070] After controlling the grinding wheel to stop descending, the wafer polishing equipment needs to obtain the second wafer thickness of the wafer to be polished in the previous polishing cycle, as well as the second distance recorded in the previous polishing cycle when the grinding wheel descends to contact the wafer to be polished and the sum of the pressure data reaches the first preset pressure.

[0071] After obtaining the second wafer thickness and the second distance of the previous polishing cycle, the wear amount of the grinding wheel in the previous polishing cycle can be further determined based on the first wafer thickness, the first distance, the second wafer thickness and the second distance. In one embodiment, the calculation formula for the wear amount of the grinding wheel in the previous polishing cycle is as follows:

[0072]

[0073] in, is the amount of wear, is the first distance, is the first wafer thickness, is the second distance, It is understandable that, on the basis of controlling the distance between the grinding wheel and the wafer to be polished after descending in each polishing cycle by the first preset pressure, after determining the difference in wafer thickness, the wear amount of the grinding wheel in the previous polishing cycle can be determined according to the further descending distance of the grinding wheel in the current polishing cycle compared with that in the previous polishing cycle.

[0074] Based on the above embodiment, in step 104, the wear amount of the grinding 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, including:

[0075] Step 1041 : Obtain a preset correction coefficient, where the correction coefficient is used to compensate for the deviation between the actual moving distance of the grinding wheel transmission shaft and the recorded distance.

[0076] In one embodiment, before calculating the wear amount of the grinding wheel, a preset correction coefficient needs to be obtained, wherein the correction coefficient is used to compensate for the deviation between the actual moving distance of the grinding wheel transmission shaft and the recorded distance. It is understandable that since there is inevitably a certain deviation between the value of the motor encoder of the grinding wheel transmission shaft and the actual moving distance of the grinding wheel, the correction coefficient needs to be used for correction. The correction coefficient can be obtained in advance through measurement tests.

[0077] Step 1042: Determine 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.

[0078] Step 1043: Determine the wear amount of the grinding wheel in the last polishing cycle according to the correction coefficient, the first value, and the second value.

[0079] Finally, the wear amount of the grinding wheel in the last polishing cycle can be determined based on the correction coefficient, the first value and the second value. The specific calculation formula is:

[0080]

[0081] in, k In this embodiment, the method of calculating the wear amount of the grinding wheel by obtaining the preset correction coefficient can further improve the accuracy of calculating the wear amount and improve the processing effect.

[0082] Step 105 : updating the accumulated wear amount according to the wear amount, and polishing the wafer to be polished when the accumulated wear amount is less than a preset wear threshold.

[0083] After determining the amount of wear of the grinding wheel in the previous polishing cycle, it is necessary to further update the cumulative wear, that is, based on the cumulative wear updated in the previous polishing cycle, add the amount of wear of the grinding wheel in the previous polishing cycle to get the cumulative wear of the grinding wheel in the current polishing cycle. After updating the cumulative wear, it is further determined whether the updated cumulative wear is less than the preset wear threshold. If it is less than the preset wear threshold, the process of polishing the wafer to be polished continues. The specific process of polishing can refer to the prior art and will not be repeated in this embodiment. If it is not 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 grinding wheel.

[0084] As described above, an embodiment of the present invention provides a wafer polishing method. In the embodiment of the present invention, a pressure sensor is arranged on the side of the grinding wheel opposite to its grinding surface, and in each polishing cycle, the grinding wheel transmission 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 contacts the wafer to be polished and the sum of the pressure data received by the pressure sensor is the first preset pressure, and then the first distance the grinding wheel descends is recorded. After that, the wear amount of the grinding wheel in the previous polishing cycle can be calculated according to the first distance of the current polishing cycle and the first wafer thickness of the wafer to be processed, as well as the second distance of the grinding wheel descending in the previous polishing cycle and the second wafer thickness of the wafer to be processed. The embodiment of the present invention can accurately monitor the wear of the grinding wheel, and the operation process is simple and fast, without other expensive professional measuring instruments, reducing the dependence on professional equipment and operators, reducing the complexity of operation and measurement costs, reducing the time waste caused by the cumbersome measurement and calculation process, and solving the technical problems of low accuracy and long time consumption in the process of detecting the wear of the grinding wheel in the prior art.

[0085] In the actual polishing process, in each polishing cycle, the grinding wheel needs to be self-polished before polishing the wafer to be polished to improve the surface quality of the grinding wheel and remove surface defects of the grinding wheel. Figure 3 As shown, Figure 3 The schematic diagram of the structure of another wafer polishing device provided by an embodiment of the present invention, wherein the wafer polishing device further comprises a sharpening platform 6, on which a sharpening stone 7 is arranged, and the sharpening stone 7 is used to grind the grinding wheel 3. After entering a new polishing cycle, the wafer polishing method provided by this embodiment controls the grinding wheel transmission shaft to lower the grinding wheel toward the wafer polishing platform so that the grinding surface of the grinding wheel contacts the wafer to be polished, and further comprises:

[0086] Step 201, control the grinding wheel transmission shaft to move the grinding wheel to above the grindstone, control the grinding wheel transmission shaft to lower the grinding wheel until it contacts the grindstone, and then control the grinding wheel to perform self-polishing.

[0087] In this embodiment, when controlling the grinding wheel for self-polishing, it is necessary to control the grinding wheel transmission shaft to move the grinding wheel above the whetstone, and then control the grinding wheel transmission shaft to control the grinding wheel to descend. When the grinding wheel descends to contact the whetstone, the grinding wheel can be controlled to rotate for self-polishing.

[0088] Step 202: When self-polishing is completed, control the grinding wheel transmission shaft to move the grinding wheel to a reference position.

[0089] After the self-polishing is completed, the grinding wheel transmission shaft can be controlled to move the grinding wheel to the reference position to prepare for polishing the wafer to be polished. It can be understood that since the grinding wheel will wear out during the self-polishing process, the wear amount of the grinding wheel in the previous polishing cycle determined in the current polishing cycle also includes the wear amount caused by the self-polishing of the grinding wheel in this polishing cycle, that is, the wear amount of the grinding wheel is the wear amount of the grinding wheel during the period from the time when the polishing of the wafer to be polished started in the previous polishing cycle to the time when the polishing of the wafer to be polished started in the current polishing cycle.

[0090] Based on the above embodiment, the wafer polishing equipment needs to perform shape grinding before polishing a batch of wafers to be polished, so as to grind the grinding surface of the grinding wheel into a specific shape according to the actual polishing requirements, such as a V-shaped surface or a conical surface. Specifically, before entering the first polishing cycle, it also includes:

[0091] Step 301, control the grinding wheel transmission shaft to move the grinding wheel to above the grindstone, control the grinding wheel transmission shaft to lower the grinding wheel until it contacts the grindstone, and then control the grinding wheel to perform shape grinding.

[0092] In this embodiment, before entering a polishing cycle, it is also necessary to control the grinding wheel transmission shaft to move the grinding wheel above the grindstone, and then control the grinding wheel transmission shaft to lower the grinding wheel until it contacts the grindstone, and then perform shape sharpening according to the preset sharpening amount.

[0093] Step 302: When the shape grinding is completed, control the grinding wheel transmission shaft to move the grinding wheel to the reference position.

[0094] When the shape grinding of the grinding wheel is completed, the grinding wheel drive shaft can be controlled to move the grinding wheel to the reference position to prepare for entering the first polishing cycle to polish the first wafer to be polished. It should be noted that the shape grinding generally only needs to be performed once, but if the polishing quality of the wafer is not good, the shape grinding can be performed again.

[0095] In the present embodiment, after entering the first polishing cycle, the grinding wheel in the first polishing cycle will perform self-polishing, resulting in wear. Since there is no previous polishing cycle before the first polishing cycle, the wear amount caused by the self-polishing of the grinding wheel in the first polishing cycle also needs to be determined in the present embodiment. The wear amount caused by self-polishing is the accumulated wear amount updated in the first polishing cycle.

[0096] Specifically, after entering the first polishing cycle and before the grinding wheel self-polishes, it also includes:

[0097] Step 303: 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.

[0098] In this embodiment, after entering the first polishing cycle, before the grinding wheel performs self-polishing, it is also necessary to control the grinding wheel drive 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 (the wafer to be polished has not been placed at this time). At the same time, in this process, it is also necessary to determine the sum of the pressure data of the pressure sensor in real time.

[0099] Step 304: When the sum of the pressure data reaches the first preset pressure, the grinding wheel is controlled to stop descending and a third distance that the grinding wheel descends compared to the reference position is recorded.

[0100] When it is detected that the sum of the pressure data collected by the pressure sensor reaches the first preset pressure, the grinding wheel is controlled to stop descending, and the third distance that the grinding wheel descends compared to the reference position is recorded. The first preset pressure is the same as above, which is 100N.

[0101] In the first polishing cycle, the accumulated wear volume is updated in the following way;

[0102] Step 305: Update the accumulated wear amount 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 grinding wheel drive 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 contacts the wafer to be polished. In addition, while controlling the grinding wheel to descend, it is necessary to collect the sum of the pressure data of the pressure sensor in real time to detect the pressure exerted on the grinding wheel in real time. In the process of controlling the grinding wheel to descend, when it is detected that the sum of the pressure data reaches the first preset pressure, the grinding wheel is controlled to stop descending, and the first distance that the grinding wheel has descended compared to the reference position is recorded at the same time. Afterwards, the accumulated wear amount 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:

[0104]

[0105] in, is the third distance, is the first distance corresponding to the first polishing cycle, is the first wafer thickness corresponding to the first polishing cycle.

[0106] It is understandable that in the first polishing cycle, if a new grinding wheel is used, L0 is the accumulated wear amount; if an old grinding wheel is used in the first polishing cycle, it is necessary to call the accumulated wear amount data of the old grinding wheel in the previous processing process stored in the wafer polishing equipment, use the wear amount data plus L0 to update the accumulated wear amount, and determine whether the accumulated wear amount is less than the preset wear threshold. In one embodiment, Figure 4 As shown, Figure 4 A schematic diagram of the principle of a wafer polishing method provided by an embodiment of the present invention, Figure 4 The detailed process of updating the accumulated wear of the grinding wheel in each polishing cycle is demonstrated.

[0107] As described above, an embodiment of the present invention provides a wafer polishing method. When determining the wear amount of the grinding wheel in each polishing cycle, the embodiment of the present invention also takes into account the wear amount caused by the self-polishing of the grinding wheel in each polishing cycle, thereby further improving the accuracy of calculating the wear amount of the grinding wheel. The operation process is simple and fast, reducing the time wasted due to the cumbersome 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 grinding wheel in the prior art.

[0108] Furthermore, in order to ensure the rapidity of the grinding wheel's descent during polishing, the stability of the pressure feedback from the pressure sensor, and the safety during the polishing process, in one embodiment, the grinding wheel transmission 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 contacts the wafer to be polished, including:

[0109] Step 400: 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 pressure data during the lowering process.

[0110] In this embodiment, in the process of controlling the grinding wheel to descend, it is necessary to dynamically control the descending speed of the grinding wheel according to the sum of the pressure data collected by the pressure sensor. For example, when the sum of the pressure data is 0, the grinding wheel can be controlled to descend at a faster speed to improve the polishing efficiency; and when the sum of the collected pressure data is not 0, the grinding wheel can be controlled to descend at a slower or uniform speed to ensure safety during the polishing process.

[0111] On the basis of the above embodiment, the descending speed of the grinding wheel is dynamically controlled according to the sum of the pressure data during the descending process, including:

[0112] Step 401, when the sum of the pressure data is zero and the position of the grinding wheel has not reached the preset position corresponding to the current polishing cycle, control the grinding wheel to descend at a first preset speed, and the preset position is determined according to the empty cutting position of the current polishing cycle.

[0113] In this embodiment, it is first necessary to determine the preset position corresponding to the current polishing cycle, wherein the preset position is determined according to the empty cutting position of the current polishing cycle. Specifically, the empty cutting position of the current polishing cycle can be calculated by the following formula:

[0114]

[0115] in, It is the empty cutting position; is the third distance; is the wafer thickness of the wafer to be polished in the nth polishing cycle; To preset the empty cutting amount; The accumulated wear value updated for the nth polishing cycle.

[0116] After the empty cutting position is determined, the empty cutting position can be used as the preset position corresponding to the current polishing cycle. Afterwards, when the sum of the pressure data detected by all the pressure sensors is 0 and the position of the grinding wheel has not reached the preset position corresponding to the current polishing cycle, the grinding wheel is controlled to descend at a first preset speed, wherein the first preset speed can be set according to actual needs and is not specifically limited in this embodiment.

[0117] Step 402: When the position of the grinding wheel exceeds a preset position corresponding to the current polishing cycle, control the grinding wheel to descend at a second preset speed.

[0118] When the position of the grinding wheel exceeds the preset position corresponding to the current polishing cycle, the grinding wheel is controlled to descend at a second preset speed, wherein the second preset speed is less than the first preset speed.

[0119] Step 403: When the sum of the pressure data is within the preset pressure range, determine the first real-time speed in real time based on the sum of the pressure data, the first preset pressure and the second preset speed, and control the grinding wheel to descend at the first real-time speed until the sum of the pressure data reaches the first preset pressure.

[0120] When the sum of the pressure data is within the preset pressure range, it is necessary to determine 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. In this embodiment, the preset pressure range can be set to (0, 100) N. Specifically, 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 includes:

[0121] Step 4031: determine a first difference between a first preset pressure and the sum of the pressure data, and determine a ratio of the first difference to the sum of the pressure data.

[0122] Step 4032: Determine the product of the second preset speed and the ratio to obtain a real-time reference speed.

[0123] Specifically, the calculation formula of the real-time reference speed is:

[0124]

[0125] in is the first preset pressure, in this example =100N. is the sum of the pressure data, is the real-time reference speed, The second preset speed.

[0126] Step 4033: Determine a first real-time speed according to the real-time reference speed.

[0127] After determining the real-time reference speed, the first real-time speed can be further determined based on 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 to be 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 the third preset speed, the real-time reference speed is determined to be 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 to be the first real-time speed. That is, the specific expression formula of the first real-time speed is as follows:

[0128]

[0129] in For the first real-time speed, is the third preset speed, which is the critical polishing speed. When the sum of the pressure data of the pressure sensor on the grinding wheel is close to 100N, the reference speed becomes smaller and smaller until it is less than , the grinding wheel speed changes to the critical polishing speed Polishing, the specific process is as follows Figure 5 As shown, Figure 5 A schematic diagram of a method for controlling the descending speed of a grinding wheel provided in an embodiment of the present invention.

[0130] As described above, the embodiment of the present invention dynamically controls the descending speed of the grinding wheel according to the sum of the pressure data, so as to achieve a multi-speed soft landing when the grinding wheel descends, thereby improving the polishing efficiency and ensuring the stability of the polishing and the product quality.

[0131] The embodiment of the present invention also provides a wafer polishing device, such as Figure 6 As shown, Figure 6The schematic diagram of the structure of the wafer polishing device provided in the embodiment of the present invention is applicable to the wafer polishing equipment, which 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; at least one pressure sensor is provided on the side of the grinding wheel opposite to its grinding surface, and the wafer polishing device includes:

[0132] The data acquisition module 501 is used to acquire the first wafer thickness of the wafer to be polished and the accumulated wear amount of the grinding wheel updated in the previous polishing cycle after entering a new polishing cycle. One polishing cycle is a process of completing polishing of one wafer to be polished.

[0133] The grinding wheel lowering module 502 is used 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 contacts the wafer to be polished, and to determine the sum of the pressure data of the pressure sensor in real time;

[0134] The distance recording module 503 is used to control the grinding wheel to stop descending and record a first distance that the grinding wheel descends compared to the reference position when the sum of the pressure data reaches a first preset pressure;

[0135] The wear determination module 504 is used to obtain the second wafer thickness of the wafer to be polished and the second distance recorded by the grinding wheel in the last polishing cycle, 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;

[0136] The wafer polishing module 505 is used to update the accumulated wear amount according to the wear amount, and polish the wafer to be polished when the accumulated wear amount is less than a preset wear threshold.

[0137] Based on the above embodiment, the wear determination module 504 includes:

[0138] A coefficient acquisition submodule is used to acquire a preset correction coefficient, and the correction coefficient is used to compensate for the deviation between the actual moving distance of the grinding wheel transmission shaft and the recorded distance;

[0139] A numerical calculation submodule, used to determine a first numerical value of the sum of the first wafer thickness and the first distance, and a second numerical value of the sum of the second wafer thickness and the second distance;

[0140] The wear amount determination submodule is used to determine the wear amount of the grinding wheel in the last polishing cycle according to the correction coefficient, the first value and the second value.

[0141] On the basis of the above embodiment, the wafer polishing equipment further includes a sharpening platform, on which a sharpening stone is arranged; and further includes:

[0142] The self-polishing module is used to control the grinding wheel transmission shaft to move the grinding wheel above the grindstone after entering a new polishing cycle, and to control the grinding wheel transmission shaft to lower the grinding wheel to the wafer polishing platform so that the grinding surface of the grinding wheel contacts the wafer to be polished, and then control the grinding wheel to perform self-polishing after the grinding wheel transmission shaft is controlled to lower the grinding wheel to contact the grindstone;

[0143] The first position recovery module is used to control the grinding wheel transmission shaft to move the grinding wheel to the reference position when the self-polishing is completed.

[0144] Based on the above embodiment, it also includes a shape sharpening module, which is used to control the grinding wheel transmission shaft to move the grinding wheel above the grindstone before entering the first polishing cycle, control the grinding wheel transmission shaft to lower the grinding wheel to contact the grindstone, and then control the grinding wheel to perform shape sharpening;

[0145] The second position recovery module is used to control the grinding wheel transmission shaft to move the grinding wheel to the reference position when the shape grinding is completed.

[0146] Based on the above embodiment, the grinding wheel lowering module 502 further includes:

[0147] The first cycle descending submodule is used to control the grinding wheel transmission shaft to descend the grinding wheel from the reference position to the wafer polishing platform after entering the first polishing cycle and before the grinding wheel self-polishes, 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;

[0148] A third distance recording submodule, for controlling the grinding wheel to stop descending and recording a third distance that the grinding wheel descends compared to the reference position when the sum of the pressure data reaches a first preset pressure;

[0149] The wear determination module 504 is further configured to update the accumulated wear amount in the first polishing cycle according to the third distance, the first wafer thickness corresponding to the first polishing cycle, and the first distance.

[0150] Based on the above embodiment, the grinding wheel descending module 502 is specifically used to control the grinding wheel transmission shaft to descend the grinding wheel from the reference position to the wafer polishing platform, and dynamically control the descending speed of the grinding wheel according to the sum of pressure data during the descending process.

[0151] Based on the above embodiment, the grinding wheel lowering module 502 includes:

[0152] A first speed reduction submodule, used for controlling the grinding wheel to reduce at a first preset speed when 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, wherein the preset position is determined according to the empty cutting position of the current polishing cycle;

[0153] A second speed reduction submodule, used for controlling the grinding wheel to reduce at a second preset speed when the position of the grinding wheel exceeds a preset position corresponding to the current polishing cycle;

[0154] The dynamic speed reduction submodule is used to determine 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 when the sum of the pressure data is within the preset pressure range, and control the grinding wheel to decrease at the first real-time speed until the sum of the pressure data reaches the first preset pressure.

[0155] Based on the above embodiment, the dynamic speed reduction submodule is specifically used to determine a first difference between a first preset pressure and the sum of pressure data, determine a ratio of the first difference to the sum of pressure data; determine the product of a second preset speed and the ratio to obtain a real-time reference speed; and determine a first real-time speed based on the real-time reference speed.

[0156] On the basis of the above embodiment, the dynamic speed reduction submodule is specifically used to determine that the second preset speed is the first real-time speed when the real-time reference speed is greater than the second preset speed; when the real-time reference speed is less than or equal to the second preset speed and greater than or equal to the third preset speed, determine that the real-time reference speed is 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, determine the third preset speed as the first real-time speed.

[0157] The wafer polishing device provided in the embodiment of the present invention is included in the wafer polishing equipment, and can be used to execute the wafer polishing method provided in the above embodiment, and has corresponding functions and beneficial effects.

[0158] It is worth noting that in the above-mentioned embodiment of the wafer polishing device, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0159] The present embodiment also provides a wafer polishing device, which includes a grinding wheel transmission shaft 1, a grinding wheel 3 and a wafer polishing platform 5; the grinding wheel transmission 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; at least one pressure sensor 2 is provided on the side of the grinding wheel 3 opposite to its grinding surface, and the wafer polishing device also includes a processor 8 and a memory 9; Figure 7 As shown, Figure 7 A circuit schematic diagram of a wafer polishing device provided in this embodiment.

[0160] The memory 9 is used to store a computer program 91 and transmit the computer program 91 to the processor 8;

[0161] 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.

[0162] Exemplarily, the computer program 91 may be divided into one or more modules / units, one or more modules / units are stored in the memory 9 and executed by the processor 8 to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 91 in the wafer polishing device.

[0163] The wafer polishing device may include, but is not limited to, a processor 8 and a memory 9. Those skilled in the art will appreciate that Figure 7 It is only an example of wafer polishing equipment and does not constitute a limitation of the wafer polishing equipment. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the wafer polishing equipment may also include input and output devices, network access equipment, buses, etc.

[0164] The processor 8 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0165] The memory 9 may be an internal storage unit of the wafer polishing device, such as a hard disk or memory of the wafer polishing device. The memory 9 may also be an external storage device of the wafer polishing device, such as a plug-in hard disk equipped on the wafer polishing device, a smart media card (SMC), a secure digital (SD) card, a flash card (FlashCard), etc. Furthermore, the memory 9 may also include both an internal storage unit and an external storage device of the wafer polishing device. The memory 9 is used to store computer programs and other programs and data required by the wafer polishing device. The memory 9 may also be used to temporarily store data that has been output or is to be output.

[0166] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0167] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods 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. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0168] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0169] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0170] If the integrated unit is implemented 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 solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store computer programs.

[0171] An embodiment of the present invention further provides a storage medium containing computer executable instructions, which are used to execute a wafer polishing method when executed by a computer processor. The method includes the following steps:

[0172] After entering a new polishing cycle, the first wafer thickness of the wafer to be polished and the cumulative wear amount of the grinding wheel updated in the previous polishing cycle are obtained. One polishing cycle is a process of completing polishing of one wafer to be polished.

[0173] Controlling 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 to be polished, and determining the sum of the pressure data of the pressure sensor in real time;

[0174] When the sum of the pressure data reaches a first preset pressure, the grinding wheel is controlled to stop descending and a first distance that the grinding wheel descends compared to the reference position is recorded;

[0175] Obtaining a second wafer thickness of the wafer to be polished in a previous polishing cycle and a recorded second distance of the grinding wheel descending, and determining the wear amount 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;

[0176] The accumulated wear amount is updated according to the wear amount, and when the accumulated wear amount is less than a preset wear threshold, the wafer to be polished is polished.

[0177] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the embodiments of the present invention are not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the embodiments of the present invention. Therefore, although the embodiments of the present invention are described in more detail through the above embodiments, the embodiments of the present invention are not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the embodiments of the present invention, and the scope of the embodiments of the present invention is determined by the scope of the appended claims.

Claims

1. A wafer polishing method, the method is applicable to a wafer polishing device, the wafer polishing device comprises 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; characterized in that: At least one pressure sensor is provided on a surface of the grinding wheel opposite to its grinding surface, and the wafer polishing method comprises: After entering a new polishing cycle, obtaining a first wafer thickness of the wafer to be polished and the accumulated wear amount of the grinding wheel updated in the last polishing cycle, wherein one polishing cycle is a process of completing polishing of one wafer to be polished; Controlling 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 to be polished, and determining the sum of the pressure data of the pressure sensor in real time; When the sum of the pressure data reaches a first preset pressure, controlling the grinding wheel to stop descending and recording a first distance that the grinding wheel descends compared to the reference position at this time; Obtaining a second wafer thickness of the wafer to be polished in a previous polishing cycle and a recorded second distance that the grinding wheel descends, and determining the wear amount 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; updating the accumulated wear amount according to the wear amount, and polishing the wafer to be polished when the accumulated wear amount is less than a preset wear threshold; Wherein, determining the wear amount 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 includes: Obtaining a preset correction coefficient, wherein the correction coefficient is used to compensate for the deviation between the actual moving distance of the grinding wheel transmission shaft and the recorded distance; Determining 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; The wear amount of the grinding wheel in the last polishing cycle is determined according to the correction coefficient, the first value and the second value. The specific formula is: in, is the wear amount of the grinding wheel in the previous polishing cycle, is the first distance, is the first wafer thickness, is the second distance, is the thickness of the second wafer, k is the correction coefficient; The step of controlling 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 to be polished comprises: Controlling the grinding wheel transmission shaft to lower the grinding wheel from the reference position to the wafer polishing platform, and dynamically controlling the descending speed of the grinding wheel according to the sum of the pressure data during the descending process; The step of dynamically controlling the descending speed of the grinding wheel according to the sum of the pressure data during the descending process includes: When 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 grinding wheel is controlled to descend at a first preset speed, wherein the preset position is determined according to the empty cutting position of the current polishing cycle; When the position of the grinding wheel exceeds a preset position corresponding to the current polishing cycle, controlling the grinding wheel to descend at a second preset speed; When the sum of the pressure data is within the preset pressure range, the first real-time speed is determined in real time based on the sum of the 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 the pressure data reaches the first preset pressure.

2. The wafer polishing method according to claim 1, characterized in that: The wafer polishing equipment also includes a grinding platform, on which a grindstone is arranged; after entering a new polishing cycle, before controlling 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 to be polished, the device also includes: Controlling the grinding wheel transmission shaft to move the grinding wheel to above the grindstone, controlling the grinding wheel transmission shaft to lower the grinding wheel until it contacts the grindstone, and controlling the grinding wheel to perform self-polishing; When the self-polishing is completed, the grinding wheel transmission shaft is controlled to move the grinding wheel to the reference position.

3. The wafer polishing method according to claim 2, characterized in that: After entering the first polishing cycle and before the grinding wheel self-polishing, it also includes: Controlling 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 determining the sum of the pressure data of the pressure sensor in real time; When the sum of the pressure data reaches a first preset pressure, controlling the grinding wheel to stop descending and recording a third distance that the grinding wheel descends compared to the reference position at this time; In the first polishing cycle, the accumulated wear amount is updated in the following manner; The accumulated wear amount is updated according to the third distance, a first wafer thickness corresponding to a first polishing cycle, and the first distance.

4. The wafer polishing method according to claim 1, characterized in that: The step of determining 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 includes: 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; determining a product of the second preset speed and the ratio to obtain a real-time reference speed; A first real-time speed is determined according to the real-time reference speed.

5. The wafer polishing method according to claim 4, characterized in that: The determining the first real-time speed according to the real-time reference speed comprises: When the real-time reference speed is greater than the second preset speed, determining the second preset speed as the first real-time speed; In the case where the real-time reference speed is less than or equal to the second preset speed and greater than or equal to the third preset speed, the real-time reference speed is determined to be the first real-time speed, and the third preset speed is less than the second preset speed; the third preset speed is the critical polishing 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.

6. A wafer polishing device, which is suitable for wafer polishing equipment, and the wafer polishing equipment comprises 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; characterized in that, The grinding wheel is provided with at least one pressure sensor on a side opposite to the grinding surface thereof, and the wafer polishing device comprises: A data acquisition module, used for acquiring the first wafer thickness of the wafer to be polished and the accumulated wear amount of the grinding wheel updated in the last polishing cycle after entering a new polishing cycle, wherein one polishing cycle is a process of completing polishing of one wafer to be polished; A grinding wheel descending module, used for controlling the grinding wheel transmission shaft to descend the grinding wheel from the reference position to the wafer polishing platform, so that the grinding surface of the grinding wheel contacts the wafer to be polished, and determining the sum of the pressure data of the pressure sensor in real time; A distance recording module, used for controlling the grinding wheel to stop descending and recording a first distance descended by the grinding wheel compared to the reference position when the sum of the pressure data reaches a first preset pressure; a wear determination module, used for obtaining a second wafer thickness of the wafer to be polished in a previous polishing cycle and a recorded second distance that the grinding wheel descends, and determining the wear amount 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; A wafer polishing module, used for updating the accumulated wear amount according to the wear amount, and polishing the wafer to be polished when the accumulated wear amount is less than a preset wear threshold; Wherein, the wear determination module includes: A coefficient acquisition submodule, used for acquiring a preset correction coefficient, wherein the correction coefficient is used for compensating for a deviation between an actual moving distance of the grinding wheel transmission shaft and a recorded distance; a numerical calculation submodule, configured to determine a first numerical value of the sum of the first wafer thickness and the first distance, and a second numerical value of the sum of the second wafer thickness and the second distance; The wear amount determination submodule is used to determine the wear amount of the grinding wheel in the previous polishing cycle according to the correction coefficient, the first value and the second value. The specific formula is: in, is the wear amount of the grinding wheel in the previous polishing cycle, is the first distance, is the first wafer thickness, is the second distance, is the thickness of the second wafer, k is the correction coefficient; The grinding wheel descending module is specifically used to control the grinding wheel transmission shaft to descend the grinding wheel from the reference position to the wafer polishing platform, and dynamically control the descending speed of the grinding wheel according to the sum of the pressure data during the descending process; Wherein, the grinding wheel lowering module comprises: A first speed reduction submodule, configured to control the grinding wheel to reduce at a first preset speed when 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, wherein the preset position is determined according to the empty cutting position of the current polishing cycle; A second speed reduction submodule, configured to control the grinding wheel to reduce at a second preset speed when the position of the grinding wheel exceeds a preset position corresponding to a current polishing cycle; The dynamic speed reduction submodule is used to determine 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 when the sum of the pressure data is within the preset pressure range, and control the grinding wheel to decrease at the first real-time speed until the sum of the pressure data reaches the first preset pressure.

7. A wafer polishing device, 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 the wafer; characterized in that, The grinding wheel is provided with at least one pressure sensor on a side opposite to its grinding surface, and the wafer polishing device further includes a processor and a memory; The memory is used to store a computer program and transmit the computer program to the processor; The processor is used to execute the wafer polishing method as described in any one of claims 1 to 5 according to the instructions in the computer program.

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