Spindle coordinate correction method, wear amount detection method, grinding method, and grinding machine

Abstract

The invention discloses a main shaft coordinate correction method of a grinding and cutting machine, the grinding and cutting machine comprises a wafer bearing table used for bearing a wafer and a grinding wheel installed at the end of a main shaft and used for grinding and cutting the wafer, and the main shaft coordinate correction method comprises the following steps that in the process that the grinding wheel conducts grinding and cutting operation on the wafer, the wafer bearing table is used for bearing the wafer; monitoring the thickness of the wafer in real time; when it is determined that the thickness of the wafer reaches a preset value, the current coordinate of the main shaft is corrected based on the reference coordinate of the main shaft and the preset value; wherein the reference coordinate of the main shaft is the coordinate of the main shaft when the grinding wheel is located at the height of the wafer bearing table.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor processing, specifically to the technical field of wafer grinding, and particularly to a spindle coordinate correction method, a wear amount detection method, a grinding method, and a grinding machine. Background Art

[0002] In the production process of semiconductors, wafers are generally ground by a wafer grinding machine. The wafer grinding machine uses a spindle to drive a grinding wheel located at the end of the spindle to move downward to contact a wafer to be ground located below the grinding wheel. When the grinding wheel contacts the wafer to be ground, the spindle drives the grinding wheel to rotate and / or the rotating of the wafer stage carrying the wafer to perform a grinding operation on the wafer to be ground.

[0003] In the prior art, during the movement of the spindle, the spindle coordinates are used to control the actual movement position of the spindle / grinding wheel. In order to ensure the accuracy of the spindle coordinates, zeroing is usually required during the use of the grinding machine to correct the spindle coordinates. However, the traditional sensor-based spindle zeroing method may cause a large zeroing error of the spindle due to reasons such as the movement speed and acceleration of the spindle, that is, the actual position where the spindle is located after zeroing is not the position of the predefined zero coordinate.

[0004] Furthermore, during the subsequent movement of the spindle based on the zero coordinate, the spindle coordinates also have a large error. That is, during the process of controlling the movement of the spindle / grinding wheel based on the spindle coordinates, the actual movement position will have a large deviation from the expected theoretical movement position, which will reduce the accuracy and quality of the grinding operation, and seriously affect the safety of the grinding operation. For example, the theoretical lowering position of the grinding wheel corresponding to the spindle coordinate A is the position where its distance from the wafer stage is A, but due to the large error of the spindle coordinates, the actual lowering position of the grinding wheel may be much less than A from the wafer stage. In this way, phenomena such as the wafer being ground too thin and the grinding wheel colliding strongly with the wafer may occur. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the related art, the purpose of the present application is to provide a spindle coordinate correction method, a wear amount detection method, a wafer grinding method, a wafer grinding machine, a computer-readable storage medium, and a computer device applied to a grinding machine, so as to solve the technical problems of reducing the accuracy and quality of the grinding operation and affecting the safety of the grinding operation due to the large spindle coordinate error in the prior art.

[0006] To achieve the above and other related objectives, a method for correcting the spindle coordinates of a grinding machine is provided in the first aspect of the present application. The grinding machine includes a wafer carrier for carrying a wafer and a grinding wheel installed at the end of the spindle for grinding the wafer. The method for correcting the spindle coordinates includes the following steps: during the process of the grinding wheel grinding a wafer, the thickness of the wafer is monitored in real time; when it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the spindle are corrected based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer carrier.

[0007] In the second aspect of the present application, a method for detecting the wear amount of the grinding wheel of a grinding machine is provided. The grinding machine includes a wafer carrier for carrying a wafer and a spindle connected to the grinding wheel for driving the grinding wheel to move up and down. The method for detecting the wear amount of the grinding wheel includes: during the process of the grinding wheel grinding a wafer, the thickness of the wafer is monitored in real time; when it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the spindle are corrected based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer carrier; the wear amount of the grinding wheel is determined based on the corrected coordinates and the coordinates before correction of the spindle and recorded or output.

[0008] In the third aspect of the present application, a method for grinding a wafer of a grinding machine is provided. The grinding machine includes a wafer carrier for carrying a wafer and a spindle connected to the grinding wheel for driving the grinding wheel to move up and down. The method for grinding a wafer includes: during the process of the grinding wheel grinding a wafer, the thickness of the wafer is monitored in real time; when it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the spindle are corrected based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer carrier; the spindle is controlled to continue moving based on the corrected coordinates and the coordinates of the spindle are updated in real time.

[0009] The fourth aspect of the present application provides a wafer grinding machine, further comprising: a machine base provided with a loading and unloading station and a processing station; a wafer carrier provided on the machine base and capable of reciprocating between the loading and unloading station and the processing station for carrying the wafer to be ground; a grinding mechanism provided on the machine base, including a main shaft, a grinding wheel detachably mounted at the end of the main shaft, and a driving module for driving the main shaft to move up and down at the processing station, wherein the axis of the grinding wheel coincides with the axis of the main shaft; a control device for real-time monitoring of the thickness of the wafer during the process of controlling the grinding wheel to perform a grinding operation on a wafer; and when it is determined that the thickness of the wafer reaches a preset value, correcting the current coordinate of the main shaft based on the reference coordinate of the main shaft and the preset value; wherein the reference coordinate of the main shaft is the coordinate of the main shaft when the grinding wheel is at the height of the wafer carrier.

[0010] The fifth aspect of the present application discloses a computer-readable storage medium storing at least one program, and when the at least one program is called, it executes and implements the main shaft coordinate correction method as described in any one of the embodiments disclosed in the first aspect of the present application, or the grinding wheel wear amount detection method as described in any one of the embodiments disclosed in the second aspect of the present application, or the wafer grinding method as described in any one of the embodiments disclosed in the third aspect of the present application.

[0011] The sixth aspect of the present application discloses a computer device, comprising: a storage device for storing at least one program; a processing device connected to the storage device for implementing the main shaft coordinate correction method as described in any one of the embodiments disclosed in the first aspect of the present application, or the grinding wheel wear amount detection method as described in any one of the embodiments disclosed in the second aspect of the present application, or the wafer grinding method as described in any one of the embodiments disclosed in the third aspect of the present application when calling and executing the at least one program from the storage device.

[0012] In summary, the main shaft coordinate correction method, wear amount detection method, wafer grinding method, wafer grinding machine, computer-readable storage medium, and computer device provided by the present application can accurately correct the main shaft coordinate, reduce the error of the main shaft coordinate, and further improve the accuracy, quality, and safety of the grinding operation by real-time monitoring of the thickness of the wafer during the grinding operation of the grinding wheel on the wafer, and when the monitored wafer thickness reaches the preset value, correcting the current coordinate of the main shaft based on the preset reference coordinate of the main shaft and the preset value. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The specific features involved in the present application are shown in the appended claims. The features and advantages of the invention involved in the present application can be better understood by referring to the exemplary embodiments and the drawings described in detail below. A brief description of the drawings is as follows:

[0014] Figure 1 It shows a schematic structural diagram of a single-station wafer grinding machine in an embodiment of the present application.

[0015] Figure 2 It shows a schematic structural diagram of a wafer being arranged on a chuck through an adapter in an embodiment of the present application.

[0016] Figure 3 It shows a schematic structural diagram of a drive module connected to a main shaft in an embodiment of the present application.

[0017] Figure 4 It shows a schematic structural diagram of a multi-station wafer grinding machine in an embodiment of the present application.

[0018] Figure 5 It shows a flowchart of a method for correcting the coordinate of the main shaft of a grinding machine in an embodiment of the present application.

[0019] Figure 6 It shows a schematic diagram of the principle of a detection device detecting the thickness of a wafer in an embodiment of the present application.

[0020] Figure 7a It shows a schematic diagram of the current coordinate of the main shaft when the thickness of the wafer reaches a preset value in an embodiment of the present application.

[0021] Figure 7b It shows a schematic diagram of the coordinate after correcting the current coordinate of the main shaft in an embodiment of the present application.

[0022] Figure 8 It shows a flowchart of a method for detecting the wear amount of a grinding wheel of a grinding machine in an embodiment of the present application.

[0023] Figure 9 It shows a schematic diagram of a display interface of the wear amount of a grinding wheel in an embodiment of the present application.

[0024] Figure 10 It shows a flowchart of a method for grinding a wafer of a grinding machine in an embodiment of the present application.

[0025] Figure 11a It shows a schematic diagram of the state when the main shaft rises to the first coordinate in an embodiment of the present application.

[0026] Figure 11b It shows a schematic diagram of the state when the main shaft descends to the second coordinate in an embodiment of the present application.

[0027] Figure 12a It shows a schematic diagram of the coordinate of the main shaft when the grinding wheel is at the height of the wafer carrier in an embodiment of the present application.

[0028] Figure 12bIt shows a schematic diagram of the state where the main shaft is located at the first safety coordinate in an embodiment of the present application.

[0029] Figure 13 It shows a schematic diagram of the structure of a computer device in an embodiment of the present application. Detailed implementation manners

[0030] The following specific embodiments illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification.

[0031] In the following description, reference is made to the accompanying drawings, which describe several embodiments of the present application. It should be understood that other embodiments may also be used, and mechanical composition, structure, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is only defined by the claims of the published patent. The terms used herein are only for describing specific embodiments and are not intended to limit the present application. Spatially related terms, such as "upper", "lower", "left", "right", "below", "beneath", "lower", "above", "upper", etc., may be used in the text to facilitate the description of the relationship between one element or feature shown in the figure and another element or feature.

[0032] Although in some instances the terms first, second, etc. are used herein to describe various elements or parameters, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another. For example, the first safety coordinate may be referred to as the second safety coordinate, and similarly, the second safety coordinate may be referred to as the first safety coordinate, without departing from the scope of the various described embodiments. The first safety coordinate and the second safety coordinate are both describing a safety coordinate, but they are not the same safety coordinate unless the context clearly indicates otherwise.

[0033] Furthermore, as used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms, unless the context indicates otherwise. It should be further understood that the terms "comprising", "including" indicate the presence of the described features, steps, operations, elements, components, items, types, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, types, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or meaning any one or any combination.

[0034] The present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts belong to the scope of protection of the present application. The phrase "an implementation manner", "implementation manner" or similar expressions mentioned throughout this specification mean that the specific features, structures or characteristics described in conjunction with the implementation manner are included in at least one implementation manner of the present application. Therefore, the appearance of the phrases "in an implementation manner", "in the implementation manner" and similar expressions throughout this specification may (but not necessarily) relate to the same implementation manner.

[0035] As described in the background art, the traditional sensor-based spindle zeroing method may cause a large zeroing error of the spindle due to factors such as the movement speed and acceleration of the spindle, resulting in the actual position of the spindle after zeroing not being the position of the pre-defined zero coordinate. Furthermore, during the subsequent movement of the spindle based on the zero coordinate, the spindle coordinate also has a large cumulative error as the working time extends. Thus, the accuracy and quality of the grinding operation will be reduced, and in severe cases, the safety of the grinding operation will also be affected.

[0036] In view of this, in some embodiments provided by the present application, a spindle coordinate correction method, a wear amount detection method, a grinding method and a grinding machine are disclosed. By monitoring the thickness of the wafer in real time during the process of a grinding wheel grinding a wafer, when it is determined that the thickness of the wafer reaches a preset value, the current coordinate of the spindle is corrected based on the reference coordinate of the spindle and the preset value, eliminating the problem that the traditional sensor-based spindle zeroing method may have a large cumulative error due to the long-term operation of the spindle. Thus, the present application can accurately correct the spindle coordinate, reduce the error of the spindle coordinate, and further improve the accuracy, quality and safety of the grinding operation.

[0037] The grinding machine (also known as a wafer grinding machine) is a semiconductor processing device that grinds the back surface of a wafer using a grinding wheel. That is, the wafer grinding machine can perform back thinning on the thickness of the wafer (also known as a silicon wafer). In some embodiments, the wafer grinding machine may also be referred to as a lapping machine or a thinning machine. After thinning the thickness of the wafer using the wafer grinding machine, it is easier to fabricate more complex integrated circuits using the wafer, and it can reduce the package height, decrease the chip package volume, improve the thermal diffusion efficiency, electrical performance, and mechanical performance of the chip, etc. Further, when the wafer grinding machine performs the grinding operation, it can also achieve polishing of the wafer. In different embodiments, the wafer grinding machine can be a single-station grinding machine, a double-station grinding machine, or a multi-station grinding machine. This application does not limit the detailed structure of the wafer grinding machine, as long as it satisfies that the grinding wheel provided at the end of the main shaft in the wafer grinding machine can move up and down at the processing station under the drive of the drive module of the main shaft to perform the grinding operation on the wafer to be ground carried on the wafer stage.

[0038] In one embodiment, please refer to Figure 1 , which shows a schematic structural diagram of a single-station wafer grinding machine in an embodiment of this application. As shown in the figure, the wafer grinding machine includes: a machine base 1, a wafer stage 2, a grinding mechanism 3, and a control device (not shown in the figure). The machine base 1 is provided with a loading / unloading station and a processing station. The wafer stage 2 and the grinding mechanism 3 are disposed on the machine base 1. The wafer stage 2 can reciprocate between the loading / unloading station and the processing station to carry the wafer to be ground. The grinding mechanism 3 includes a main shaft 32, a grinding wheel 30 detachably mounted at the end of the main shaft 32, and a drive module for driving the main shaft 32 to move. The control device can control the main shaft 32 to move up and down at the processing station to contact the wafer to be ground and perform the grinding operation on the wafer to be ground. During the grinding operation, the control device also real-time monitors the thickness of the wafer after being ground. When it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the main shaft 32 are corrected based on the reference coordinates of the main shaft 32 and the preset value.

[0039] The machine base 1 is used to carry the wafer stage 2. Further, as Figure 1 shown, the machine base 1 is also used to carry the grinding mechanism 3. The machine base 1 is provided with a loading / unloading station and a processing station. Among them, the loading station is the position where the wafer stage 2 carries the silicon wafer, the unloading station is the position where the grinding machine removes the ground silicon wafer from the wafer stage 2, and the processing station is the position where the silicon wafer is ground by the grinding mechanism 3. The loading station and the unloading station can be at the same position or at different positions.

[0040] The wafer stage 2 is disposed on the machine base 1 and can reciprocate between the loading / unloading station and the processing station. In one example, the wafer stage 2 reciprocates linearly between the loading / unloading station and the processing station. For example, as Figure 1 shown, the wafer stage 2 and the grinding mechanism 3 in the single-station grinding machine are arranged on the same straight line. The loading station and the unloading station in the single-station grinding machine are at the same position. After the wafer stage 2 carries the wafer to be ground at the loading station (for example, Figure 1 the position where the wafer stage 2 is located in the figure), it moves along the direction shown by X in the figure to the processing station. After the wafer to be ground is ground by the grinding mechanism 3 at the processing station, the wafer stage 2 carries the ground wafer and moves along the opposite direction of X in the figure to the unloading station for the grinding machine to take away the ground wafer. After the ground wafer is taken away, the wafer stage 2 continues to load at the current position.

[0041] In one embodiment, if one wafer is carried on the wafer stage 2, the wafer and the wafer stage 2 are coaxial. That is, the axis of the wafer is the intersection point of the axis of the wafer when it rotates and the wafer, and the axis of the wafer stage is the intersection point of the axis of the wafer stage when it rotates and the wafer stage. When the wafer is placed on the wafer stage, their axes coincide. Wherein, the axis of the wafer is a straight line passing through the center of the wafer and perpendicular to the wafer. Similarly, the axis of the wafer stage is a straight line passing through the center of the wafer stage and perpendicular to the wafer stage.

[0042] In another embodiment, one wafer stage 2 can carry one wafer or multiple wafers. For example, when multiple wafers are carried on the wafer stage, the multiple wafers are distributed around the center of the wafer stage and the distances from the centers of the multiple wafers to the center are the same. When multiple wafers are carried on the wafer stage, during the grinding operation of the wafer grinding machine, the wafer stage 2 rotates the wafers to the processing station in sequence for thinning.

[0043] In some embodiments, the wafer can be disposed on the chuck of the wafer stage or can be disposed on the wafer stage through an adapter. For example, a chuck for adsorbing and fixing the wafer is disposed on the top of the wafer stage, and the axis of the chuck coincides with the axis of the wafer stage. Wherein, the axis of the chuck is a straight line passing through the center of the chuck and perpendicular to the chuck. The chuck is a vacuum chuck, and the wafer is directly adsorbed on the chuck of the wafer stage.

[0044] During actual grinding operations, there may be cases where some wafers cannot be directly adsorbed by the susceptor. For example, the adsorption holes on the upper surface of the chuck used for processing 12-inch wafers may be located at the edge of the chuck. However, for 4-8 inch wafers, such a chuck will not be able to achieve the adsorption and fixation of the wafers, and subsequent processing cannot be carried out. For this reason, in some embodiments of the present application, an adapter is proposed. Please refer to Figure 2 , which shows a schematic structural diagram of a wafer being disposed on a chuck through an adapter in an embodiment of the present application. As shown in the figure, the wafer 4 is attached to the adapter 21, and the size of the adapter 21 satisfies that it can be adsorbed and fixed by the chuck 20 on the susceptor. Specifically, the adapter 21 with the attached wafer 4 is placed on the chuck 20 on the susceptor and fixed by vacuum adsorption. Among them, the wafer attached to the adapter 21 can be one or more. During actual processing, the size of the adapter 21 satisfies that when it is placed on the chuck 20, it can cover the adsorption holes on the chuck 20. When attaching the wafer 4 to the adapter 21, glue can be applied to the wafer 4 and then attached to the adapter 21. At this time, the adapter 21 can be without an adhesive layer. Further, the top surface of the adapter 21 can also have an adhesive layer 210, so that the wafer 4 can be directly adhered to the adhesive layer 210.

[0045] Although in the above embodiments, the example of the chuck directly adsorbing one wafer at a time is used for illustration, in other embodiments, the chuck can also directly adsorb two or more wafers. In other words, the chuck has two or more adsorption areas for adsorbing the wafers, and each adsorption area is provided with a vacuum adsorption hole. The shapes and sizes of the adsorption areas can be the same or different.

[0046] The susceptor 2 carries the wafer to be ground and moves it to the processing station, and the grinding mechanism 3 performs grinding operations on the wafer to be ground.

[0047] Please continue to refer to Figure 1 , the grinding mechanism 3 is disposed on the machine base 1 for contacting the wafer located at the processing station and performing grinding operations on the whole or part of the wafer. As shown in the figure, the grinding mechanism 3 includes a main shaft 32, a grinding wheel 30 detachably mounted at the end of the main shaft 32, and a driving module 31 for driving the main shaft 32 to move up and down at the processing station. Among them, the axis of the grinding wheel 30 coincides with the axis of the main shaft 32. The axis of the grinding wheel 30 is a straight line passing through the center of the grinding wheel 30 and perpendicular to the grinding wheel 30. Similarly, the axis of the main shaft 32 is a straight line passing through the center of the main shaft 32 and perpendicular to the main shaft 32.

[0048] In some embodiments, when the grinding wheel 30 is grinding the wafer, the grinding wheel 30 can be driven to rotate by the spindle 32 and / or the wafer stage 2 can be rotated to drive the wafer to rotate so as to grind the entire wafer or part of the wafer.

[0049] For example, the driving module 31 drives the spindle 32 to descend, and when the spindle 32 descends to a preset distance from the upper surface of the wafer or contacts the surface of the wafer, the control device controls the wafer stage 2 to rotate to drive the wafer to rotate, so as to achieve thinning or polishing of the wafer as a whole or in part. It should be noted that the wafer stage 2 can also be in a rotating state when located at the processing station.

[0050] For example, Figure 1 As shown, the wafer stage 2 carrying the wafer moves to the processing station along the slide rail 10 located on the machine base 1. The drive module 31 drives the spindle 32 to descend. When the grinding wheel 30 descends to a preset distance from the upper surface of the wafer or contacts the surface of the wafer, the drive module 31 also drives the spindle 32 to rotate to drive the grinding wheel 30 to rotate, and then the whole or part of the wafer is thinned or polished by the continuous descent and rotation of the grinding wheel. When the processing is completed, the drive module 31 drives the grinding wheel 30 and the spindle 32 to reset, for example, drives the spindle 32 to move up to the first safety coordinate described later to complete the reset, and the wafer stage 2 carries the processed wafer and moves along the guide rail again to the loading and unloading station for the wafer grinding machine to take the wafer away.

[0051] It should be noted that, although in the present embodiment the wafer table 2 moves along the slide rail 10 on the machine base 1, and the driving module 31 drives the spindle 32 to rotate when the grinding wheel 30 descends to a preset distance from the upper surface of the wafer or contacts the surface of the wafer, it is not limited to this. The wafer table 2 may also be arranged on a mechanism that can move back and forth, such as a conveyor belt, and the driving module 31 may also drive the spindle 32 to rotate while the spindle 32 is rising or falling.

[0052] In one embodiment, see Figure 3 , which is a schematic diagram of the structure of the connection between the drive module and the spindle in one embodiment of the present application, as shown in the figure, the drive module 31 includes a drive component 316 and a servo motor 315. The drive component 316 is connected to the spindle 32. The servo motor 315 is used to be connected to the drive component 316 in a transmission manner to drive the drive component 316 to drive the spindle 32 to move up and down at the processing station.

[0053] In this embodiment, the driving assembly 316 includes a lead screw 3160, a guide rail 3161, and a slider 3162. The servo motor 315 is in transmission connection with the lead screw 3160, and the lead screw 3160 is connected to one end of the main shaft 32. The servo motor 315 drives the lead screw 3160 to cause the main shaft 32 to move upward or downward under the drive of the lead screw 3160. The slider 3162 is slidably arranged on the guide rail 3161, and the slider 3162 is connected to the main shaft 32, so that the main shaft 32 can slide upward or downward on the guide rail 3161 under the drive of the lead screw 3160. In one example, as Figure 3 shown, the guide rails 3161 are respectively arranged on opposite sides of the main shaft 32. Correspondingly, the number of the sliders 3162 is also configured to be two, and the two sliders 3162 are respectively arranged on opposite sides of the main shaft 32. Among them, the lead screw can also be replaced by mechanisms such as a cylinder, a hydraulic cylinder, or an electric push rod.

[0054] The encoder of the servo motor 315 can record the displacement data of the servo motor (such as angular displacement, linear displacement, etc.) for the control device to calculate the position / coordinate of the main shaft according to the displacement data. In one example, the encoder is an absolute encoder. Thus, when the wafer grinding machine restarts due to power failure or other reasons, the control device can still obtain the coordinate of the main shaft before restart and continue to control the movement of the main shaft based on the coordinate of the main shaft before restart.

[0055] Furthermore, the driving module 31 may further include a servo motor for driving the grinding wheel 30 to rotate.

[0056] It should be noted that the driving module 31 may also be other structures as long as it can drive the main shaft to move in the vertical direction.

[0057] In one embodiment, the driving module of the grinding mechanism 3 further includes a driving mechanism capable of driving the main shaft to move in the horizontal direction. The driving mechanism includes a driving member for driving the main shaft to move in the front-rear direction and / or a driving member for driving the main shaft to move in the left-right direction. The driving member is exemplified by a cylinder.

[0058] In one embodiment, the driving module 31 further includes a connection with the servo motor (such as Figure 3The shown servo motor 315 is connected to a speed reducer (not shown), and the speed reducer is used to reduce the output speed of the servo motor. In a specific embodiment, the speed reducer is connected to the drive component 316 in the drive module 31 described above and the output shaft of the servo motor 315, so as to reduce the speed of the main shaft. For example, the speed reducer is connected to the lead screw 3160 in the servo motor 315 and the drive component 316. Among them, the speed reducer is exemplified as a gear reducer, a planetary reducer, etc.

[0059] In one embodiment, the control device includes a storage device and a processing device. The storage device stores at least one program, and the processing device is connected to the storage device and is used to execute the at least one program.

[0060] In some embodiments, the processing device includes an integrated circuit chip with signal processing capabilities; or a general-purpose processor. For example, it can be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), discrete gate or transistor logic devices, discrete hardware components, which can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0061] In some embodiments, the storage device may include a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc. The memory is used to store programs (such as programs corresponding to the main shaft coordinate correction method, the grinding wheel wear amount detection method, the wafer grinding method, etc.). After receiving the execution instruction, the processor executes the program.

[0062] In one embodiment, the control device can execute the main shaft coordinate correction method of the grinding machine, and the main shaft coordinate correction method can be the main shaft coordinate correction method described in any subsequent embodiment of the present application, and reference can be made to the Figure 5 main shaft coordinate correction method shown later, which will not be elaborated here.

[0063] The control device is used to monitor the thickness of the wafer in real time during the process of controlling the grinding wheel to grind a wafer. When it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the spindle are corrected based on the reference coordinates of the spindle and the preset value. Wherein, the preset value is the target value for the grinding operation of the wafer. The reference coordinates of the spindle are configured as the zero coordinates of the spindle.

[0064] In one embodiment, the control device can execute the grinding wheel wear amount detection method of the grinding machine. The grinding wheel wear amount detection method can be the grinding wheel wear amount detection method described in any subsequent embodiment of the present application, and reference can be made to the Figure 8 grinding wheel wear amount detection method shown later, which will not be elaborated here.

[0065] In one embodiment, the control device is further used to determine, record or output the wear amount of the grinding wheel based on the coordinates of the spindle after correction and the coordinates before correction.

[0066] Furthermore, the control device is further used to determine the total wear amount of the grinding wheel as the sum of the wear amounts of the grinding wheel determined each time after correcting the coordinates. When the control device determines that the total wear amount of the grinding wheel reaches the disk change threshold, a prompt message for changing the grinding wheel is issued.

[0067] In one embodiment, the control device can execute the wafer grinding method of the grinding machine. The wafer grinding method can be the wafer grinding method described in any subsequent embodiment of the present application, and reference can be made to the Figure 10 wafer grinding method shown later, which will not be elaborated here.

[0068] The control device is used to calibrate the reference coordinates of the spindle before the first grinding operation for the grinding machine to control the movement of the spindle based on the reference coordinates of the spindle. After the coordinates of the spindle are corrected, the control device is further used to control the spindle to continue to move based on the corrected coordinates for the next grinding operation.

[0069] In one embodiment, the wafer grinding machine further includes a detection device, which is used to detect the thickness of the wafer or output the detected data to the control device for the control device to calculate the thickness of the wafer. For example, the data output by the detection device can directly be the thickness of the wafer. Thus, during the grinding operation, the detection device can detect the thickness of the wafer in real time, and the control device can obtain the data output by the detection device in real time to achieve real-time monitoring of the thickness of the wafer. For another example, the data output by the detection device is indirect data for determining the thickness of the wafer. Thus, during the grinding operation, the detection device outputs the detected data to the control device in real time, and the control device can calculate the thickness of the wafer according to the obtained indirect data to achieve real-time monitoring of the thickness of the wafer.

[0070] Among them, the detection device can be a contact detection device, an optoelectronic detection device or a vision detection device.

[0071] In one embodiment, the detection device is an optoelectronic detection device. When grinding the wafer, the optoelectronic detection device can emit a first beam to the grinding surface of the wafer and a second beam to the top surface of the wafer carrier or the top surface of the adapter in real time, and receive the first beam and the second beam in real time. The thickness of the wafer can be calculated according to the difference in the propagation time of the two simultaneously emitted beams.

[0072] In another embodiment, the detection device is a vision detection device. When grinding the wafer, the vision detection device obtains the depth image of the wafer in real time, and the control device obtains the depth image of the wafer in real time and determines the thickness of the wafer by using the depth image.

[0073] In yet another embodiment, the detection device is a contact detection device, and the contact detection device measures the thickness of the wafer by contacting the grinding surface of the wafer in real time. For specific examples of the contact detection device measuring the thickness of the wafer, reference can be made to the relevant descriptions of the embodiments shown later Figure 6 and will not be elaborated here.

[0074] It should be noted that the present application does not limit the method for determining the thickness of the wafer, as long as the control device can obtain the thickness of the wafer in real time.

[0075] In one embodiment, the wafer grinding machine further includes an input device, which is used to provide a human-machine interaction interface for pre-inputting the thickness of the adapter. The output device is, for example, a touch screen connected to the control device.

[0076] In one embodiment, the wafer grinding machine further includes a display device for displaying the wear amount of the grinding wheel and / or the total wear amount of the grinding wheel determined after each coordinate correction. In one example, the control device outputs both the wear amount of the grinding wheel and the total wear amount of the grinding wheel determined after each coordinate correction to the display device for display by the display device. In another example, the display device is only used to display the wear amount of the grinding wheel or the total wear amount of the grinding wheel determined after each coordinate correction. Among them, the display device is, for example, a display screen or a touch screen connected to the control device. Further, the display device can be the same touch screen as the input device.

[0077] In one embodiment, please refer to Figure 4 , which shows a schematic structural diagram of a multi-station wafer grinding machine in one embodiment of the present application. As shown in the figure, the wafer grinding machine includes: a machine base 1', a wafer chuck 2', a grinding mechanism 3', and a control device (not shown).

[0078] The machine base 1' is provided with a loading / unloading station and a processing station. The wafer chuck 2' and the grinding mechanism 3' are arranged on the machine base 1'. The wafer chuck 2' can reciprocate between the loading / unloading station and the processing station to carry the wafer to be ground. The grinding mechanism 3' includes a main shaft, a grinding wheel detachably mounted at the end of the main shaft, and a driving module for driving the main shaft to move. The control device can control the main shaft to move up and down at the processing station to contact the wafer to be ground and perform a grinding operation on the wafer to be ground. During the grinding operation, the control device also real-time monitors the thickness of the wafer after grinding. When it is determined that the thickness of the wafer reaches a preset value, the current coordinate of the main shaft is corrected based on the reference coordinate of the main shaft and the preset value.

[0079] The function and structure of the machine base 1' are the same as or similar to those of the machine base 1 of the single-station wafer grinding machine described above, and will not be elaborated here.

[0080] The wafer chuck 2' is arranged on a dividing table 5'. The dividing table 5' drives the wafer chuck 2' to move relative to the grinding wheel in the grinding mechanism 3' to the processing station by rotation. In one embodiment, the way the wafer is carried on the wafer chuck 2' is the same as or similar to that described above, and will not be elaborated here.

[0081] In one embodiment, the number of the wafer chucks 2' is set to be multiple, and the multiple wafer chucks 2' are evenly arranged on the dividing table 5'. Further, the number of main shafts in the grinding mechanism 3' is one less than the number of wafer chucks 2' so that the wafer chucks 2' and the main shafts cooperate with each other to realize the simultaneous processing of multiple wafers, thereby achieving a higher processing efficiency for the wafers.

[0082] Among them, each set of spindles and grinding wheels in the grinding mechanism 3' correspondingly includes a set of driving modules, and the functions and structures of the driving modules are the same as or similar to those of the driving module 31 of the single-station wafer grinding machine described above, and will not be elaborated here.

[0083] The data acquired, stored, and the methods executed by the control device, as well as its structure and functions, are the same as or similar to those described above, and will not be elaborated here. The multi-station wafer grinding machine further includes an input device, a detection device, a display device, etc., and the functions of the input device, the detection device, and the display device are the same as or similar to those described above, and will not be elaborated here.

[0084] In some embodiments, the present application discloses a method for correcting the spindle coordinates of a grinding machine. In some examples, the spindle coordinate correction method can be executed by the single-station grinding machine or the multi-station grinding machine described above. Further, it can be executed by a control device configured on the single-station grinding machine or the multi-station grinding machine. In the following embodiments, if the type of the grinding machine is not distinguished in the steps, then both the single-station grinding machine or the multi-station grinding machine can execute. It should be noted that the present application does not limit the specific structure of the grinding machine that executes the spindle coordinate correction method.

[0085] In one embodiment, please refer to Figure 5 , which shows a flowchart of the spindle coordinate correction method of the grinding machine in one embodiment of the present application. As shown in the figure, the spindle coordinate correction method includes step S110 and step S120.

[0086] In step S110, during the process of the grinding wheel grinding a wafer, the control device monitors the thickness of the wafer in real time.

[0087] Specifically, during the process of the grinding wheel grinding a wafer, the thickness of the wafer gradually decreases, and during the process of the gradual decrease of the wafer thickness, the control device monitors its thickness in real time; in other words, during the process of the grinding wheel grinding a wafer, the control device monitors the thickness of the ground part of the wafer in real time. In one embodiment, during the grinding operation, the ground surface of the wafer is not completely covered by the grinding wheel, so as to facilitate the monitoring of the thickness of the wafer. Among them, the ground surface is the top surface of the wafer ground by the grinding wheel. It should be understood that the "monitoring" is to monitor and measure the thickness of the wafer in real time during the grinding operation. In the present application, "monitoring" can also be understood as "detecting" the thickness of the wafer in real time.

[0088] In one embodiment, the thickness of the wafer is directly detected by the detection device. Specifically, the detection device directly detects the thickness of the wafer, and the control device obtains the thickness of the wafer in real time to monitor the thickness. In another embodiment, the thickness of the wafer is calculated using the data detected by the detection device. Specifically, the data detected by the detection device is intermediate data for calculating the thickness of the wafer, and the control device obtains and uses the intermediate data in real time to calculate the thickness of the wafer to monitor the thickness.

[0089] Among them, the detection device includes a contact detection device, an optoelectronic detection device, or a vision detection device. In one embodiment, the detection device is an optoelectronic detection device. When performing a grinding operation on the wafer, the optoelectronic detection device can emit a first beam to the grinding surface of the wafer and a second beam to the top surface of the wafer carrier or the top surface of the rotating member in real time, and receive the first beam and the second beam in real time. The thickness of the wafer can be calculated based on the difference in the propagation times of the two simultaneously emitted beams.

[0090] In another embodiment, the detection device is a vision detection device. When performing a grinding operation on the wafer, the vision detection device obtains a depth image of the wafer in real time, and the control device obtains the depth image of the wafer in real time and determines the thickness of the wafer using the depth image.

[0091] In yet another embodiment, the detection device is a contact detection device, and the contact detection device measures the thickness of the wafer by coming into real-time contact with the grinding surface of the wafer. In the following specific embodiments, the contact detection device is taken as an example for illustration.

[0092] In this embodiment, the detection device is a contact detection device, the wafer is directly adsorbed on the wafer carrier, and the thickness of the wafer is determined based on the top surface height of the wafer measured by the detection device and the top surface height of the wafer carrier. Specifically, please refer to Figure 6, which shows the schematic diagram of the detection device for detecting the thickness of the wafer in an embodiment of the present application. As shown in the figure, the detection device 6 includes a first measurement component 61 and a second measurement component 62. Before the grinding operation starts, the measurement end (such as a probe) of the first measurement component 61 is made to abut against the top surface of the part of the wafer 4 to be ground, and the measurement end (such as a probe) of the second measurement component 62 is made to abut against the top surface of the wafer chuck 2. During the grinding operation, the first measurement component 61 is in contact with the ground surface of the wafer 4 in real time, and the height of the top surface of the wafer detected by the first measurement component 61 will change in real time. The height of the top surface of the wafer chuck detected by the second measurement component 62 remains unchanged. Furthermore, the detection device 6 can determine the thickness of the wafer 4 in real time according to the difference between the data detected by the first measurement component 61 and the second measurement component 62. In other embodiments, the control device can also obtain in real time the height of the top surface detected by the first measurement component 61 and the second measurement component 62, and use the height of the top surface detected by the two to determine the thickness of the wafer 4 in real time.

[0093] In another specific embodiment, the wafer is attached to an adapter, and the adapter is arranged on the wafer chuck. The thickness of the wafer is determined according to the height of the top surface of the wafer measured by the detection device and the determined reference height of the top surface of the adapter. The detection device is exemplified as Figure 6 the contact detection device shown in the figure. When grinding the wafer 4, since there is an adhesive layer on the top surface of the adapter, in order to prevent the second measurement component 62 from being stuck by the adhesive layer when the wafer chuck rotates, the second measurement component 62 needs to be non-contact with the top surface of the adapter. In order to detect the thickness of the wafer, when the wafer chuck does not rotate, the detection device 6 controls the second measurement component 62 to contact the top surface of the adapter outside the wafer 4, and determines the data detected by the second measurement component 62 at this time as the reference height of the top surface of the adapter and stores it in the detection device 6 and / or the control device.

[0094] Furthermore, when grinding the wafer 4, the first measurement component 61 detects the height of the top surface of the wafer 4 in real time, that is, the data measured by the first measurement component 61 changes in real time. The detection device 6 can determine the thickness of the wafer 4 according to the difference between the data measured by the first measurement component 61 in real time and the reference height of the top surface of the adapter determined and stored in advance. In other embodiments, the control device can also store in advance the reference height of the top surface of the adapter, and the control device uses the data detected by the first measurement component 61 obtained in real time and the reference height of the top surface to determine the thickness of the wafer 4 in real time.

[0095] Among them, the first measurement component 61 and the second measurement component 62 have the same structure, and both include a contact measuring instrument, a measuring rod, and a probe. The contact measuring instrument is connected to the control device. The contact measuring instrument is connected to a horizontally extending measuring rod. The inner end of the measuring rod connected to the contact measuring instrument can rotate relative to the contact measuring instrument. After adjusting the position of the measuring rod, the measuring rod and the contact measuring instrument can be fixed by nuts and bolts. The outer end of the measuring rod is provided with a probe extending in the height direction. The probe is adjustably arranged on the measuring rod. The probe can be threadedly connected to the measuring rod or fixed by a setscrew. The probe of the second measurement component 62 is used to contact the top surface of the wafer stage or the top surface of the adapter. The probe of the first measurement component 61 is used to contact the grinding surface of the wafer 4 in real time.

[0096] It should be noted that the present application does not limit the method for determining the thickness of the wafer, as long as the control device can obtain the thickness of the wafer in real time.

[0097] In step S120, when the control device determines that the thickness of the wafer reaches a preset value, it corrects the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value.

[0098] In one embodiment, the preset value is the target value for the grinding operation of the wafer. That is, during the grinding operation, when it is determined that the thickness of the wafer reaches the target value, the control device corrects the current coordinates of the spindle based on the reference coordinates of the spindle and the target value, and at the same time stops the grinding operation. For example, control the spindle to stop descending to stop the grinding operation. Although in this embodiment, the preset value is taken as the target value for illustration, it is not limited thereto. In other embodiments, the preset value can also be any thickness value of the wafer during the grinding process. For example, when the grinding wheel just contacts the wafer, the control device corrects the current coordinates of the spindle using the thickness of the wafer that has not been ground.

[0099] The reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer stage. In one embodiment, the method further includes the step of instructing the control device to calibrate the reference coordinates of the spindle before the first grinding operation, so that the grinding machine controls the movement of the spindle based on the reference coordinates of the spindle. For example, in different embodiments, the step of calibrating the reference coordinates of the spindle is performed before the first grinding operation after the initialization of the grinding machine; or the step of calibrating the reference coordinates of the spindle is performed before the first grinding operation after replacing the grinding wheel; or the step of calibrating the reference coordinates of the spindle can be performed before the first grinding operation after restarting.

[0100] In one embodiment, the control device controls the main shaft to drive the grinding wheel to move to the height of the top surface of the wafer stage and sets the coordinates of the current position of the main shaft as the reference coordinates of the main shaft, so as to complete the calibration of the reference coordinates of the main shaft. Specifically, before the first grinding operation, the control device controls the main shaft to drive the grinding wheel to move to a position in contact with the top surface of the wafer stage, and the control device sets the coordinates of the main shaft at this time as the reference coordinates of the main shaft. In one embodiment, the reference coordinates of the main shaft are configured as the zero coordinates of the main shaft. In other words, the coordinate value of the reference coordinates of the main shaft is 0. In other embodiments, the coordinate value of the reference coordinates of the main shaft can also be set to other values.

[0101] In the process of the main shaft moving subsequently based on the calibrated reference coordinates, that is, in the process of the main shaft moving subsequently from the position when the grinding wheel is at the height of the wafer stage, the coordinates at each position of the main shaft are determined by reading the displacement data recorded by the encoder of the servo motor driving the main shaft. For example, the control device can obtain the displacement of the main shaft according to the displacement data, and then determine the coordinates at each position of the main shaft based on the reference coordinates and the displacement of the main shaft. In one embodiment, the encoder is an absolute encoder. In this way, the coordinates will not be reset after the grinding machine is powered off, and thus there is no need to perform the step of calibrating the reference coordinates of the main shaft before the first grinding operation after restarting.

[0102] It should be noted that the control device calibrates the reference coordinates of the main shaft in order to make the main shaft perform the grinding operation based on the reference coordinates during the first grinding operation to improve the coordinate accuracy of the main shaft in the first grinding operation. In other embodiments, the step of calibrating the reference coordinates of the main shaft may not be performed, and only the pre-stored reference coordinates need to be used for calibration when correcting the coordinates subsequently.

[0103] When the control device determines that the thickness of the wafer reaches a preset value, the control device directly corrects the current coordinates of the main shaft. Thus, when there is an error in the current coordinates of the main shaft, the error can be eliminated by correcting the current coordinates.

[0104] In one embodiment, the wafer is directly adsorbed on the wafer stage, and the current coordinates of the main shaft are updated to the preset value or updated to the sum of the preset value and the reference coordinates to achieve the correction of the current coordinates of the main shaft. In an example, please refer to Figure 7a and Figure 7b , Figure 7a which shows a schematic diagram of the current coordinates of the main shaft when the thickness of the wafer reaches the preset value in one embodiment of the present application, Figure 7bThe coordinate diagram of the main axis after the current coordinate of the main axis is corrected in one embodiment of the present application is shown. As shown in the figure, the reference coordinate of the main axis 32 is configured as the zero point coordinate of the main axis 32, that is, the reference coordinate of the main axis 32 is 0. When the thickness of the wafer 4 reaches Figure 7a When the preset value a is set as shown, due to the wear of the spindle grinding wheel and other reasons, the current coordinate of the spindle is ae. At this time, the control device directly updates the current coordinate of the spindle 32 to Figure 7b The preset value a shown in FIG. 1 is used to correct the current coordinate of the spindle 32, as shown in FIG. Figure 7b In another example, if the reference coordinate of the spindle is b, when the thickness of the wafer reaches a preset value a, the control device updates the current coordinate of the spindle 32 to a+b to correct the current coordinate of the spindle.

[0105] In another embodiment, when the wafer is set on the wafer table through the adapter, the control device updates the current coordinates of the spindle to the sum of the preset value and the thickness of the adapter, or updates the current coordinates of the spindle to the sum of the preset value, the thickness of the adapter and the reference coordinates, so as to correct the current coordinates of the spindle. Specifically, since the adapter is also provided between the wafer table and the wafer, and the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer table, the thickness of the adapter also needs to be considered when correcting the current coordinates of the spindle based on the preset value. In one example, if the reference coordinates of the spindle are 0 and the thickness of the adapter is c, when the thickness of the wafer reaches the preset value a, the control device updates the current coordinates of the spindle to a+c, so as to correct the current coordinates of the spindle. In another example, if the reference coordinate of the spindle is b and the thickness of the adapter is c, when the thickness of the wafer reaches a preset value a, the control device updates the current coordinate of the spindle to a+b+c to correct the current coordinate of the spindle. In this embodiment, the thickness of the adapter is pre-input through a human-computer interaction interface or obtained through real-time detection by a detection device. The detection principle of the detection device is the same or similar to that of the detection device for detecting the thickness of the wafer in the previous text, which will not be repeated here.

[0106] After the current coordinates of the spindle are corrected, the spindle continues to move based on the corrected coordinates. In the subsequent movement process, the coordinates of each position of the spindle are determined by reading the displacement data recorded by the encoder of the servo motor driving the spindle. The method of determining the coordinates of each position of the spindle is the same or similar to that described above and will not be repeated here.

[0107] In one embodiment, the spindle coordinate correction method further includes the step of recording the number of grinding operations performed by the spindle, and correcting the coordinates of the spindle according to a preset number of operations. Wherein, the preset number of operations includes one or more times.

[0108] In one example, if the preset number of operations is one, then during each grinding operation, that is, when grinding each wafer, the coordinates of the spindle are corrected when the thickness of the wafer reaches a preset value (for example, reaches the target value). In this way, it is possible to avoid a large cumulative error in the coordinates of the spindle caused by the long-term operation of the drive assembly (for example, after the drive assembly moves up and down more than 100 times and grinds more than 100 wafers, there will be a large gap in some components of the drive assembly, such as the gap between the guide rail and the lead screw. The existing gap will cause a serious out-of-sync phenomenon between the movement of the spindle and the drive assembly and the servo motor, which will increase the deviation between the position where the spindle actually moves based on the spindle coordinates and the expected theoretical movement position), and reduce the deviation between the position where the spindle actually moves and the expected theoretical movement position. It should be noted that in other examples, the control device can also correct the coordinates of the spindle during each grinding operation without recording the number of operations.

[0109] In another example, if the preset number of operations is two, then during the second grinding operation, the fourth grinding operation... the 2nth grinding operation, the coordinates of the spindle are corrected. Wherein, n is an integer.

[0110] In one embodiment, the spindle coordinate correction method further includes the step of obtaining a correction request from the user. For example, the user inputs the correction request through a human-machine interface. The correction request indicates the timing for the grinding machine to perform spindle coordinate correction. For example, the correction request indicates that the grinding machine performs spindle coordinate correction when grinding the 5th wafer after changing the grinding wheel.

[0111] The grinding machine and the spindle coordinate calibration method disclosed in this application accurately calibrate the spindle coordinates by monitoring the accurate thickness of the wafer and the reference coordinates of the spindle in real time, reducing the error of the spindle coordinates, and avoiding the large cumulative error of the spindle coordinates caused by the long-term operation of the drive assembly, thereby improving the precision, quality, and safety of the grinding operation; at the same time, it can also avoid the phenomenon of empty grinding caused by the spindle coordinates not considering the grinding wheel wear amount, and further improve the efficiency of the grinding operation; furthermore, when calibrating the spindle coordinates during each grinding operation, since the spindle coordinates are relatively accurate, the low-speed point of the spindle (the second safety coordinate described later) can be set lower to improve the efficiency of the grinding operation; further, it can also reduce the error brought by the speed reducer and reduce the precision requirements for the speed reducer, saving the production cost of the grinding machine.

[0112] In some embodiments, the present application discloses a method for detecting the wear amount of a grinding wheel of a grinding machine. In some examples, the method for detecting the wear amount of the grinding wheel can be executed by the single-station grinding machine or the multi-station grinding machine described above. Further, it can be executed by a control device configured on the single-station grinding machine or the multi-station grinding machine. In the following embodiments, if the type of the grinding machine is not distinguished in the steps, both the single-station grinding machine and the multi-station grinding machine can execute. It should be noted that the present application does not limit the specific structure of the grinding machine that executes the method for detecting the wear amount of the grinding wheel.

[0113] In one embodiment, please refer to Figure 8 , which shows a flowchart of the method for detecting the wear amount of the grinding wheel of the grinding machine in one embodiment of the present application. As shown in the figure, the method for detecting the wear amount of the grinding wheel includes step S210, step S220, and step S230.

[0114] In step S210, during the process of the grinding wheel performing a grinding operation on a wafer, the control device monitors the thickness of the wafer in real time. Step S210 is the same as or similar to the relevant description of step S110 in the spindle coordinate calibration method shown above, and will not be repeated here. Figure 5 As described above, it will not be elaborated here.

[0115] In step S220, when the control device determines that the thickness of the wafer reaches a preset value, it calibrates the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer stage. Step S220 is the same as or similar to the relevant description of step S120 in the spindle coordinate calibration method shown above, and will not be repeated here. Figure 5 As described above, it will not be elaborated here.

[0116] After correcting the coordinates of the main shaft, the control device executes step S230 to determine the wear amount of the grinding wheel.

[0117] In step S230, the control device determines the wear amount of the grinding wheel based on the coordinates of the main shaft after correction and before correction, and records or outputs it.

[0118] In an embodiment, due to the existence of the wear amount of the grinding wheel, the coordinates of the main shaft before correction are smaller than the coordinates of the main shaft after correction. The control device determines the difference between the coordinates of the main shaft after correction and the coordinates of the main shaft before correction as the wear amount of the grinding wheel. For example, still referring to Figure 7a and Figure 7b , as shown in the figure, when the thickness of the wafer reaches the preset value a, due to the existence of the wear amount of the grinding wheel, the coordinate of the main shaft is a - e. After correcting the main shaft, the coordinate of the main shaft is a. Then the control device determines that the wear amount of the grinding wheel is e.

[0119] Furthermore, when the control device records the determined wear amount of the grinding wheel, it can only record the wear amount determined each time, or it can determine the sum of the wear amounts of the grinding wheel determined after each coordinate correction as the total wear amount of the grinding wheel, and record the total wear amount. For example, during each grinding operation after the grinding wheel of the grinding machine is replaced, the coordinates of the main shaft are corrected. The wear amount of the grinding wheel determined after each correction is the wear amount generated by the grinding wheel during each grinding operation. Summing up the wear amounts generated by the grinding wheel during each grinding operation can obtain the total wear amount of the grinding wheel.

[0120] In an embodiment, when the control device determines that the total wear amount of the grinding wheel reaches the disk change threshold, it issues a prompt message for replacing the grinding wheel. Among them, the disk change threshold is, for example, 70% - 85% of the thickness of the grinding wheel. The prompt message for replacing the grinding wheel can be represented in the form of text, image, sound, etc. For example, a text prompt message such as "The grinding wheel needs to be replaced" or "It is recommended to replace the grinding wheel" is displayed on the human - machine interaction interface.

[0121] In an embodiment, when the control device outputs the determined wear amount of the grinding wheel, it can output the wear amount of the grinding wheel determined after each coordinate correction to the display device, or output the total wear amount to the display device, or output both the total wear amount and the wear amount of the grinding wheel determined after each coordinate correction to the display device. For example, please refer to Figure 9 , which shows a schematic diagram of the display interface of the wear amount of the grinding wheel in an embodiment of the present application. As shown in the figure, the control device outputs both the total wear amount M and the wear amounts (m1, m2, and m3) of the grinding wheel determined after each coordinate correction to the display device.

[0122] The grinding machine and the method for detecting the wear amount of the grinding wheel disclosed in this application calculate the wear amount of the grinding wheel by using the coordinates before and after spindle calibration, improving the calculation accuracy of the wear amount of the grinding wheel.

[0123] In some embodiments, this application discloses a wafer grinding method for a grinding machine. In some examples, the wafer grinding method can be executed by the single-station grinding machine or the multi-station grinding machine described above. Further, it can be executed by a control device configured on the single-station grinding machine or the multi-station grinding machine. In the following embodiments, if the type of the grinding machine is not distinguished in the steps, then both the single-station grinding machine and the multi-station grinding machine can execute. It should be noted that this application does not limit the specific structure of the grinding machine that executes the wafer grinding method.

[0124] In one embodiment, please refer to Figure 10 , which shows a flowchart of the wafer grinding method of the grinding machine in one embodiment of this application. As shown in the figure, the wafer grinding method includes step S310, step S320, and step S330.

[0125] In step S310, during the process of the grinding wheel grinding a wafer, the control device monitors the thickness of the wafer in real time. Step S310 is the same or similar to the relevant description of step S110 in the spindle coordinate calibration method shown above, and will not be repeated here. Figure 5 shown above, and will not be repeated here.

[0126] In step S320, when the control device determines that the thickness of the wafer reaches a preset value, it calibrates the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer chucking table. Step S320 is the same or similar to the relevant description of step S120 in the spindle coordinate calibration method shown above, and will not be repeated here. Figure 5 shown above, and will not be repeated here.

[0127] After the control device calibrates the coordinates of the spindle, it also executes step S330.

[0128] In step S330, the control device controls the spindle to continue to move based on the calibrated coordinates and updates the coordinates of the spindle in real time.

[0129] In one embodiment, during the process of the spindle continuing to move based on the calibrated coordinates, the coordinates of the spindle at each position are determined by reading the displacement data recorded by the encoder of the servo motor that drives the spindle. For example, the control device can obtain the displacement of the spindle according to the displacement data, and then determine the coordinates of the spindle at each position based on the calibrated coordinates and the displacement of the spindle.

[0130] In one embodiment, if the preset value is the target value for the grinding operation on the wafer, when the thickness of the wafer reaches the target value, the control device controls the spindle to rise to the first safety coordinate based on the corrected coordinates of the spindle to allow the wafer to be ground to move under the grinding wheel for the grinding wheel to perform the next grinding operation on the wafer. Specifically, please refer to Figure 11a and also refer to Figure 7a and Figure 7b , Figure 11a which shows a schematic diagram of the state where the spindle rises to the first coordinate in one embodiment of the present application. As shown in the figure, when the thickness of the wafer 4 reaches the preset value a, the control device corrects the current coordinate a - e of the spindle 32 to a. Since the preset value a is the target value for the grinding operation on the wafer 4, the control device needs to raise the spindle 32 from the coordinate a to the first safety coordinate f to allow the wafer 4 to be ground to move under the grinding wheel 30 for the grinding wheel 30 to perform the next grinding operation on the wafer 4 to be ground. The thickness of the wafer 4 to be ground is d. When the spindle is at the first safety coordinate f, the height of the grinding wheel from the wafer stage 2 is greater than the thickness d of the wafer 4 to be ground.

[0131] Furthermore, when the wafer to be ground moves under the grinding wheel, the control device controls the spindle to descend from the first safety coordinate to the second safety coordinate at a first speed. After the spindle descends to the second safety coordinate, the control device controls the spindle to start descending from the second safety coordinate at a second speed until the thickness of the wafer reaches the target value. Wherein, the second speed is less than the first speed, and when the spindle is at the second safety coordinate, the height of the grinding wheel from the wafer stage is greater than the thickness of the wafer to be ground. In one example, the difference between the height of the grinding wheel from the wafer stage and the thickness of the wafer to be ground when the spindle is at the second safety coordinate is in the micron order of magnitude. For example, the difference is 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, etc. In this way, it can run to a position closer to the wafer to be ground at a faster speed to improve the grinding efficiency, and can contact the wafer to be ground at a lower speed and grind the wafer to be ground to ensure the accuracy of the grinding operation.

[0132] Specifically, please refer to Figures 11a to 11b , Figure 11bShown is a schematic diagram of the state where the spindle descends to the second coordinate in an embodiment of the present application. As shown in the figure, when the spindle 32 descends from the first safety coordinate f to the second safety coordinate g, the distance between the grinding wheel 30 and the top surface of the wafer 4 to be ground is h, so as to allow the spindle 32 to drive the grinding wheel 30 to slowly descend at a second speed and grind the wafer when contacting the wafer 4 until the thickness of the wafer reaches the target value.

[0133] In an embodiment, before the grinding wheel contacts the top surface of the wafer, the control device further controls the susceptor to move relative to the grinding wheel to a position where the axis of the wafer is tangent to the outer edge of the projection circle of the grinding wheel. For example, when the spindle ascends to the first safety coordinate, the control device controls the susceptor to carry the wafer to be ground to move so that the axis of the wafer is tangent to the outer edge of the projection circle of the grinding wheel. Wherein, the axis of the wafer is a straight line passing through the center of the wafer and perpendicular to the wafer. The axis being tangent to the outer edge of the projection circle means that there is an intersection point between the outer edge of the projection circle and the axis. For example, if the projection circle of the grinding wheel is formed by the grinding wheel installed on the spindle projecting orthogonally onto the horizontal plane passing through the center point of the wafer, then the intersection point is the center point of the wafer.

[0134] Furthermore, the diameter of the grinding wheel is smaller than the radius of the wafer. In this way, when grinding the wafer in the case where the axis of the wafer is tangent to the outer edge of the projection circle of the grinding wheel, an annular region can be formed at the edge of the wafer relative to the grinding surface, and the width of the annular region is the difference between the radius of the wafer and the diameter of the grinding wheel.

[0135] In an embodiment, after obtaining the reference coordinate of the spindle before the first grinding operation, the control device further controls the spindle to move to the first safety coordinate based on the reference coordinate to allow the wafer to be ground to move below the grinding wheel. Wherein, the first safety coordinate is the same as or similar to that described above and will not be elaborated here.

[0136] Please refer to Figure 12a and Figure 12b , Figure 12a Shown is a schematic diagram of the coordinate of the spindle when the grinding wheel is at the height of the susceptor in an embodiment of the present application. Figure 12b Shown is a schematic diagram of the state where the spindle is at the first safety coordinate in an embodiment of the present application. As shown in the figure, taking the reference coordinate of the spindle 32 being configured as the zero coordinate as an example, when the grinding wheel 30 contacts the susceptor 2, the control device determines the coordinate of the position where the spindle 32 is located at this time as the zero coordinate of the spindle 32. Then, for the first grinding operation, the control device controls the spindle 32 to ascend to the first safety coordinate f.

[0137] Further, when the wafer to be ground moves below the grinding wheel, the control device controls the main shaft to descend from the first safety coordinate to the second safety coordinate at a first speed. After the main shaft descends to the second safety coordinate, the control device controls the main shaft to start descending from the second safety coordinate until the thickness of the wafer reaches the target value, so as to complete the first grinding operation. Wherein, the second speed is less than the first speed, and the height of the grinding wheel from the wafer chuck when the main shaft is at the second safety coordinate is greater than the thickness of the wafer to be ground. In one example, the difference between the height of the grinding wheel from the wafer chuck and the thickness of the wafer to be ground when the main shaft is at the second safety coordinate is in the order of micrometers. For example, the difference is 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, etc. In this way, it is possible to run at a relatively fast speed to a position close to the wafer to be ground to improve the grinding efficiency, and at the same time, it is possible to contact the wafer to be ground at a relatively low speed and grind the wafer to be ground to ensure the accuracy of the grinding operation.

[0138] The grinding machine and the wafer grinding method of the grinding machine disclosed in the present application accurately correct the main shaft coordinates by real-time monitoring of the accurate thickness of the wafer and the reference coordinates of the main shaft. Not only can the error of the main shaft coordinates be reduced, but also the large cumulative error of the main shaft coordinates caused by the long-term operation of the driving component can be avoided, thereby improving the accuracy, quality and safety of the grinding operation; at the same time, the phenomenon of idle grinding caused by the main shaft coordinates not considering the grinding wheel wear amount can be avoided, and further the efficiency of the grinding operation can be improved; further, since the coordinates of the main shaft are relatively accurate, the second safety coordinate can be set lower to improve the efficiency and safety of the grinding operation.

[0139] The present application also provides a computer-readable and writable storage medium, on which at least one program is stored, and the at least one program, when called, executes the main shaft coordinate correction method applied to the grinding machine described in any one of the above embodiments.

[0140] The present application further provides a computer-readable and writable storage medium, on which at least one program is stored, and the at least one program, when called, executes the grinding wheel wear amount detection method applied to the grinding machine described in any one of the above embodiments.

[0141] The present application also provides a computer-readable and writable storage medium, on which at least one program is stored, and the at least one program, when called, executes the wafer grinding method applied to the grinding machine described in any one of the above embodiments.

[0142] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application.

[0143] In the embodiments provided in this application, the computer-readable and writable storage medium may include a read-only memory (ROM, Read Only Memory), a random access memory (RAM, Random Access Memory), an EEPROM, a CD-ROM or other optical disc storage devices, a magnetic disk storage device or other magnetic storage devices, a flash memory, a USB flash drive, a portable hard disk, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer. Additionally, any connection can be appropriately referred to as a computer-readable medium. For example, if the instructions are sent from a website, a server, or other remote sources using coaxial cables, fiber optic cables, twisted pairs, digital subscriber lines (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cables, fiber optic cables, twisted pairs, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. However, it should be understood that computer-readable and writable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but are intended to refer to non-transient, tangible storage media. As used in the application, magnetic disks and optical discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs. Among them, magnetic disks usually magnetically copy data, while optical discs optically copy data using lasers.

[0144] This application also discloses a computer device, which can be configured on the single-station grinding machine or the multi-station grinding machine to implement the spindle coordinate correction method applied to the grinding machine, or the grinding wheel wear amount detection method applied to the grinding machine, or the wafer grinding method applied to the grinding machine described in any of the above embodiments. In one embodiment, the computer device is a device capable of performing digital calculations, logical processing, and information processing on data. In a specific example, the computer device is, for example, a control board card set in the grinding machine.

[0145] Please refer to Figure 13, which shows a schematic structural diagram of a computer device in an embodiment of the present application. The computer device 7 includes a storage device 70 and a processing device 71 connected to the storage device 70. Further, the computer device further includes an interface device 72.

[0146] In some embodiments, the storage device 70 is used to store at least one program, and the at least one program is executable by the processing device 71 to coordinate the spindle coordinate correction method applied to the grinding machine, or the grinding wheel wear amount detection method applied to the grinding machine, or the wafer grinding method applied to the grinding machine described in any of the above embodiments of the storage device 70.

[0147] Here, the storage device 70 includes, but is not limited to: read-only memory, random access memory, non-volatile memory. For example, the storage device 70 includes a flash device or other non-volatile solid-state storage devices. In certain embodiments, the storage device 70 may further include a memory remote from one or more processing devices 71, such as a network-attached memory accessed via an RF circuit or an external port and a communication network, where the communication network may be the Internet, one or more intranets, local area networks, wide area networks, storage area networks, etc., or a suitable combination thereof. A memory controller can control access to the memory by other components of the device, such as a CPU and a peripheral interface.

[0148] In some embodiments, the processing device 71 includes one or more processors. The processing device 71 operably performs data read and write operations with the storage device 70. The processing device 71 includes one or more general microprocessors, one or more application-specific processors (ASICs), one or more digital signal processors, one or more field-programmable logic arrays (FPGAs), or any combination thereof.

[0149] In some embodiments, the interface device 72 includes at least one interface unit, and each interface unit is respectively used to output a visual interface, receive human-computer interaction events generated according to the operations of technicians, etc., such as setting the grinding amount of the wafer. For example, the interface device 72 includes, but is not limited to: a serial interface such as an HDMI interface or a USB interface, or a parallel interface, etc. In one embodiment, the interface device 72 further includes a network communication unit, which is a device for data transmission using a wired or wireless network, and examples thereof include, but are not limited to: an integrated circuit including a network card, a local area network module such as a WiFi module or a Bluetooth module, a wide area network module such as a mobile network, etc.

[0150] In one or more exemplary aspects, the functions described in the spindle coordinate correction method applied to a grinding machine, or the grinding wheel wear amount detection method applied to a grinding machine, or the wafer grinding method applied to a grinding machine according to the present application can be implemented in the form of hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored or transmitted as one or more instructions or codes to a computer-readable medium. The steps of the methods or algorithms disclosed in the present application can be embodied in a processor-executable software module, where the processor-executable software module can be located on a tangible, non-transitory computer storage medium. The tangible, non-transitory computer storage medium can be any available medium accessible by a computer.

[0151] The flowcharts and block diagrams in the accompanying drawings described in the present application illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. Based on this, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that executes the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0152] In summary, for the grinding machine and its spindle coordinate correction method, wear amount detection method, grinding method, or wafer grinding machine, computer-readable storage medium, or computer device provided in any embodiment of the present application, by accurately monitoring the thickness of the wafer and the reference coordinates of the spindle in real time to accurately correct the spindle coordinates, not only can the error of the spindle coordinates be reduced, but also the large cumulative error of the spindle coordinates caused by the long-term operation of the drive components can be avoided, thereby improving the accuracy, quality, and safety of the grinding operation; at the same time, the phenomenon of idle grinding caused by the spindle coordinates not considering the wear amount of the grinding wheel can be avoided, and thus the efficiency of the grinding operation can be improved; further, the wear amount of the grinding wheel is calculated using the coordinates before and after spindle correction, improving the calculation accuracy of the wear amount of the grinding wheel; and because the coordinates of the spindle are relatively accurate, the second safety coordinate can be set lower to improve the efficiency and safety of the grinding operation.

[0153] According to the descriptions of the above examples, the present application provides multiple embodiments, specifically as follows:

[0154] 1. A spindle coordinate correction system for a grinding machine, the grinding machine including a wafer chuck for carrying a wafer and a grinding wheel mounted at the end of the spindle for grinding the wafer, wherein the spindle coordinate correction system includes:

[0155] A monitoring module for real-time monitoring of the thickness of the wafer during the grinding operation of the grinding wheel on a wafer.

[0156] A correction module for correcting the current coordinate of the spindle based on the reference coordinate of the spindle and the preset value when it is determined that the thickness of the wafer reaches the preset value; wherein the reference coordinate of the spindle is the coordinate of the spindle when the grinding wheel is at the height of the wafer chuck.

[0157] 2. The spindle coordinate correction system according to Embodiment 1, wherein the thickness of the wafer is directly detected by a detection device or calculated using data detected by the detection device.

[0158] 3. The spindle coordinate correction system according to Embodiment 2, wherein the detection device includes a contact detection device, a photoelectric detection device or a vision detection device.

[0159] 4. The spindle coordinate correction system according to Embodiment 3, wherein the detection device is a contact detection device, the wafer is directly adsorbed on the wafer chuck, and the thickness of the wafer is determined according to the top surface height of the wafer measured by the detection device and the top surface height of the wafer chuck.

[0160] 5. The spindle coordinate correction system according to Embodiment 3, wherein the detection device is a contact detection device, the wafer is attached to an adapter, the adapter is disposed on the wafer chuck, and the thickness of the wafer is determined according to the top surface height of the wafer measured by the detection device and the determined top surface reference height of the adapter.

[0161] 6. The spindle coordinate correction system according to Embodiment 1, wherein the preset value is a target value for the grinding operation of the wafer.

[0162] 7. The spindle coordinate correction system according to Embodiment 1, wherein the reference coordinate of the spindle is configured as the zero coordinate of the spindle.

[0163] 8. The spindle coordinate correction system according to Embodiment 1, further including a calibration module for calibrating the reference coordinate of the spindle before the first grinding operation for the grinding machine to control the movement of the spindle based on the reference coordinate of the spindle.

[0164] 9. The spindle coordinate calibration system according to Embodiment 8, wherein the calibration of the reference coordinates of the spindle performed by the calibration module before the first grinding operation includes: controlling the spindle to drive the grinding wheel to move to the height of the top surface of the wafer stage and setting the coordinates of the current position of the spindle as the reference coordinates of the spindle.

[0165] 10. The spindle coordinate calibration system according to Embodiment 1, wherein the wafer is directly adsorbed on the wafer stage, and the calibration module corrects the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value

[0166] including: updating the current coordinates of the spindle to the preset value or updating to the sum of the preset value and the reference coordinates.

[0167] 11. The spindle coordinate calibration system according to Embodiment 1, wherein the wafer is attached to an adapter, the adapter is disposed on the wafer stage, and the calibration module corrects the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value includes: updating the current coordinates of the spindle to the sum of the preset value and the thickness of the adapter, or updating to the sum of the preset value, the thickness of the adapter and the reference coordinates.

[0168] 12. The spindle coordinate calibration system according to Embodiment 1, further comprising a recording module, the recording module is used to record the number of grinding operations performed by the spindle, so as to correct the coordinates of the spindle according to a preset number of operations; the preset number of operations includes one or more times.

[0169] 13. The spindle coordinate calibration system according to Embodiment 1, wherein the wafer is attached to an adapter, the adapter is disposed on the wafer stage, and the thickness of the adapter is pre-input through a human-machine interface or obtained by real-time detection by a detection device.

[0170] 14. The spindle coordinate calibration system according to Embodiment 1 or 8, wherein the coordinates at each position after the spindle moves based on the calibrated coordinates and / or

[0171] the calibrated reference coordinates are determined by reading the displacement data recorded by an encoder; the encoder is an encoder of a servo motor for driving the spindle.

[0172] 15. The spindle coordinate calibration system according to Embodiment 14, wherein the encoder is an absolute encoder.

[0173] 16. A grinding wheel wear detection system for a grinding machine, the grinding machine including a wafer carrier for carrying a wafer and a main shaft connected to the grinding wheel for driving the grinding wheel to move up and down. Among them, the grinding wheel wear detection system includes:

[0174] A monitoring module for real-time monitoring of the thickness of the wafer during the process of the grinding wheel grinding a wafer.

[0175] A calibration module for calibrating the current coordinates of the main shaft based on the reference coordinates of the main shaft and the preset value when it is determined that the thickness of the wafer reaches the preset value; among them, the reference coordinates of the main shaft are the coordinates of the main shaft when the grinding wheel is at the height of the wafer carrier.

[0176] A wear amount determination module for determining and recording or outputting the wear amount of the grinding wheel based on the coordinates of the main shaft after calibration and before calibration.

[0177] 17. The grinding wheel wear detection system according to Embodiment 16, wherein the recording of the determined wear amount of the grinding wheel performed by the wear amount determination module includes determining the sum of the wear amounts of the grinding wheel determined after each coordinate calibration as the total wear amount of the grinding wheel.

[0178] 18. The grinding wheel wear detection system according to Embodiment 17, wherein the output of the determined wear amount of the grinding wheel performed by the wear amount determination module includes sending a prompt message for replacing the grinding wheel when it is determined that the total wear amount of the grinding wheel reaches the disk change threshold.

[0179] 19. The grinding wheel wear detection system according to Embodiment 16 or 17, wherein the output of the determined wear amount of the grinding wheel performed by the wear amount determination module includes outputting the wear amount of the grinding wheel determined after each coordinate calibration and / or the total wear amount of the grinding wheel to the display device of the grinding machine for display.

[0180] 20. A wafer grinding system for a grinding machine, the grinding machine including a wafer carrier for carrying a wafer and a main shaft connected to the grinding wheel for driving the grinding wheel to move up and down. Among them, the wafer grinding system includes:

[0181] A monitoring module for real-time monitoring of the thickness of the wafer during the process of the grinding wheel grinding a wafer.

[0182] A calibration module, which is used to calibrate the current coordinates of the main shaft based on the reference coordinates of the main shaft and the preset value when it is determined that the thickness of the wafer reaches the preset value; wherein, the reference coordinates of the main shaft are the coordinates of the main shaft when the grinding wheel is at the height of the wafer stage.

[0183] A main shaft movement module, which is used to control the main shaft to continue to move based on the calibrated coordinates and update the coordinates of the main shaft in real time.

[0184] 21. The wafer grinding system according to embodiment 20, wherein the main shaft movement module is further used to control the main shaft to move to a first safety coordinate based on the reference coordinates of the main shaft after obtaining the reference coordinates of the main shaft before the first grinding operation to allow the wafer to be ground to move under the grinding wheel.

[0185] 22. The wafer grinding system according to embodiment 21, wherein the main shaft movement module is further used for:

[0186] When the wafer to be ground moves under the grinding wheel, controlling the main shaft to descend from the first safety coordinate to a second safety coordinate at a first speed;

[0187] After the main shaft descends to the second safety coordinate, controlling the main shaft to descend from the second safety coordinate until the thickness of the wafer reaches the target value to complete the first grinding operation; wherein, the second speed is less than the first speed.

[0188] 23. The wafer grinding system according to embodiment 20, wherein the main shaft movement module is further used to control the wafer stage to move relative to the grinding wheel to a position where the axis of the wafer is tangent to the outer edge of the projection circle of the grinding wheel before the grinding wheel contacts the top surface of the wafer, so that the grinding wheel contacts the top surface of the wafer to perform a grinding operation on the wafer.

[0189] 24. The wafer grinding system according to embodiment 23, wherein the diameter of the grinding wheel is less than the radius of the wafer.

[0190] 25. The wafer grinding system according to embodiment 20, wherein the preset value is the target value for performing a grinding operation on the wafer, and the main shaft movement module's control to make the main shaft continue to move based on the calibrated coordinates and update the coordinates of the main shaft in real time includes: when the thickness of the wafer reaches the target value, controlling the main shaft to rise to the first safety coordinate based on the calibrated coordinates of the main shaft to allow the wafer to be ground to move under the grinding wheel for the grinding wheel to perform the next grinding operation on the wafer.

[0191] 26. The wafer grinding system according to Embodiment 25, wherein the spindle movement module is further configured to:

[0192] When the wafer to be ground moves below the grinding wheel, control the spindle to descend from the first safety coordinate to the second safety coordinate at a first speed;

[0193] After the spindle descends to the second safety coordinate, control the spindle to start descending from the second safety coordinate until the thickness of the wafer reaches the target value; wherein the second speed is less than the first speed.

[0194] The above embodiments are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present application should still be covered by the claims of the present application.

Claims

1. A method for calibrating the spindle coordinates of a grinding machine, the grinding machine including a wafer stage for carrying a wafer and a grinding wheel installed at the end of the spindle for grinding the wafer. Characterized in that, The spindle coordinate calibration method includes the following steps: During the process of the grinding wheel grinding a wafer, the thickness of the wafer is monitored in real time. When it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the spindle are calibrated based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the wafer stage.

2. The spindle coordinate calibration method according to claim 1, Characterized in that, The thickness of the wafer is directly detected by a detection device or calculated using the data detected by the detection device.

3. The spindle coordinate calibration method according to claim 2, Characterized in that, The detection device includes a contact detection device, an optoelectronic detection device or a vision detection device.

4. The spindle coordinate calibration method according to claim 3, Characterized in that, The detection device is a contact detection device, the wafer is directly adsorbed on the wafer stage, and the thickness of the wafer is determined according to the top surface height of the wafer measured by the detection device and the top surface height of the wafer stage.

5. The spindle coordinate calibration method according to claim 3, Characterized in that, The detection device is a contact detection device, the wafer is attached to an adapter, the adapter is arranged on the wafer stage, and the thickness of the wafer is determined according to the top surface height of the wafer measured by the detection device and the determined top surface reference height of the adapter.

6. The spindle coordinate calibration method according to claim 1, Characterized in that, The preset value is the target value for grinding the wafer.

7. The spindle coordinate calibration method according to claim 1, Characterized in that, The reference coordinates of the spindle are configured as the zero coordinates of the spindle.

8. The spindle coordinate calibration method according to claim 1, Characterized in that, It further includes the step of calibrating the reference coordinates of the spindle before the first grinding operation for the grinding machine to control the movement of the spindle based on the reference coordinates of the spindle.

9. The spindle coordinate calibration method according to claim 8, Characterized in that, The step of calibrating the reference coordinates of the spindle before the first grinding operation includes: controlling the spindle to drive the grinding wheel to move to the height of the top surface of the wafer stage and setting the coordinates of the current position of the spindle as the reference coordinates of the spindle.

10. The spindle coordinate calibration method according to claim 1, Characterized in that, The wafer is directly adsorbed on the wafer stage, and the step of calibrating the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value includes: updating the current coordinates of the spindle to the preset value or updating to the sum of the preset value and the reference coordinates.

11. The spindle coordinate calibration method according to claim 1, Characterized in that, The wafer is attached to an adapter, and the adapter is disposed on the susceptor. The step of correcting the current coordinates of the spindle based on the reference coordinates of the spindle and the preset value includes: updating the current coordinates of the spindle to the sum of the preset value and the thickness of the adapter, or updating to the sum of the preset value, the thickness of the adapter and the reference coordinates.

12. The spindle coordinate correction method according to claim 1, wherein, it further includes a step of recording the number of grinding operations performed by the spindle, and correcting the coordinates of the spindle according to a preset number of operations; the preset number of operations includes one or more times.

13. The spindle coordinate correction method according to claim 1, wherein, the wafer is attached to an adapter, the adapter is disposed on the susceptor, and the thickness of the adapter is pre-input through a human-machine interface or obtained by real-time detection by a detection device.

14. The spindle coordinate correction method according to claim 1 or 8, wherein, the coordinates at each position after the spindle moves based on the corrected coordinates and / or the calibrated reference coordinates are determined by reading the displacement data recorded by an encoder; the encoder is an encoder of a servo motor for driving the spindle.

15. The spindle coordinate correction method according to claim 14, wherein, the encoder is an absolute encoder.

16. A method for detecting the wear amount of a grinding wheel of a grinding machine, the grinding machine includes a susceptor for carrying a wafer and a spindle connected to the grinding wheel for driving the grinding wheel to move up and down, wherein, the method for detecting the wear amount of the grinding wheel includes the following steps: During the process of the grinding wheel performing a grinding operation on a wafer, the thickness of the wafer is monitored in real time; When it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the spindle are corrected based on the reference coordinates of the spindle and the preset value; wherein, the reference coordinates of the spindle are the coordinates of the spindle when the grinding wheel is at the height of the susceptor; Determine the wear amount of the grinding wheel based on the coordinates of the spindle after correction and the coordinates before correction, and record or output it.

17. The method for detecting the wear amount of the grinding wheel according to claim 16, wherein, The step of recording the determined wear amount of the grinding wheel includes determining the total wear amount of the grinding wheel as the sum of the wear amounts of the grinding wheel determined after each coordinate correction.

18. The method for detecting the wear amount of the grinding wheel according to claim 17, wherein, The step of outputting the determined wear amount of the grinding wheel includes sending a prompt message for replacing the grinding wheel when it is determined that the total wear amount of the grinding wheel reaches the disk change threshold.

19. The method for detecting the wear amount of the grinding wheel according to claim 16 or 17, wherein, The step of outputting the determined wear amount of the grinding wheel includes outputting the wear amount of the grinding wheel determined after each coordinate correction and / or the total wear amount of the grinding wheel to a display device of the grinding machine for display.

20. A wafer grinding method for a grinding machine, the grinding machine including a wafer stage for carrying a wafer and a main shaft connected to a grinding wheel for driving the grinding wheel to move up and down, characterized in that, the wafer grinding method includes the following steps: During the process of the grinding wheel grinding a wafer, the thickness of the wafer is monitored in real time; When it is determined that the thickness of the wafer reaches a preset value, the current coordinates of the main shaft are corrected based on the reference coordinates of the main shaft and the preset value; wherein, the reference coordinates of the main shaft are the coordinates of the main shaft when the grinding wheel is at the height of the wafer stage; Control the main shaft to continue to move based on the corrected coordinates and update the coordinates of the main shaft in real time.

21. The wafer grinding method according to claim 20, characterized in that, it further includes, after obtaining the reference coordinates of the main shaft before the first grinding operation, controlling the main shaft to move to a first safety coordinate based on the reference coordinates to allow the wafer to be ground to move below the grinding wheel.

22. The wafer grinding method according to claim 21, characterized in that, it further includes the following steps: When the wafer to be ground moves below the grinding wheel, control the main shaft to descend from the first safety coordinate to a second safety coordinate at a first speed; After the main shaft descends to the second safety coordinate, control the main shaft to start descending from the second safety coordinate until the thickness of the wafer reaches the target value to complete the first grinding operation; wherein, the second speed is less than the first speed.

23. The wafer grinding method according to claim 20, characterized in that, it further includes, before the grinding wheel contacts the top surface of the wafer, controlling the wafer stage to move relative to the grinding wheel to a position where the axis of the wafer is tangent to the outer edge of the projection circle of the grinding wheel, so that the grinding wheel contacts the top surface of the wafer to perform a grinding operation on the wafer.

24. The wafer grinding method according to claim 23, characterized in that, the diameter of the grinding wheel is less than the radius of the wafer.

25. The wafer grinding method according to claim 20, characterized in that, the preset value is the target value for the grinding operation on the wafer, and the step of controlling the main shaft to continue to move based on the corrected coordinates and update the coordinates of the main shaft in real time includes: when the thickness of the wafer reaches the target value, controlling the main shaft to rise to the first safety coordinate based on the corrected coordinates of the main shaft to allow the wafer to be ground to move below the grinding wheel for the grinding wheel to perform the next grinding operation on the wafer.

26. The wafer grinding method according to claim 25, characterized in that, it further includes the following steps: When the wafer to be ground moves below the grinding wheel, control the main shaft to descend from the first safety coordinate to a second safety coordinate at a first speed; After the main shaft descends to the second safety coordinate, control the main shaft to start descending from the second safety coordinate until the thickness of the wafer reaches the target value; wherein, the second speed is less than the first speed.

27. A wafer grinding machine, characterized in that, it further includes: A machine base is provided with a loading and unloading station and a processing station; A wafer carrier is arranged on the machine base and can reciprocate between the loading and unloading station and the processing station for carrying the wafer to be ground; A grinding mechanism is arranged on the machine base for grinding the wafer to be ground, including a main shaft, a grinding wheel detachably mounted at the end of the main shaft, and a driving module for driving the main shaft to move up and down at the processing station, and the axis of the grinding wheel coincides with the axis of the main shaft; A control device is used for real-time monitoring the thickness of the wafer during the process of controlling the grinding wheel to grind a wafer; when it is determined that the thickness of the wafer reaches a preset value, correcting the current coordinate of the main shaft based on the reference coordinate of the main shaft and the preset value; wherein, the reference coordinate of the main shaft is the coordinate of the main shaft when the grinding wheel is at the height of the wafer carrier.

28. The wafer grinding machine according to claim 27, wherein, The wafer is attached to an adapter, the adapter is arranged on the wafer carrier, or the wafer is directly adsorbed on the wafer carrier.

29. The wafer grinding machine according to claim 28, wherein, It further includes an input device for providing a human-machine interaction interface for pre-inputting the thickness of the adapter.

30. The wafer grinding machine according to claim 27, wherein, It further includes a detection device for detecting the thickness of the wafer or outputting the detected data to the control device for the control device to calculate the thickness of the wafer.

31. The wafer grinding machine according to claim 30, wherein, The detection device includes a contact detection device, an optoelectronic detection device or a vision detection device.

32. The wafer grinding machine according to claim 27, wherein, The preset value is the target value for grinding the wafer.

33. The wafer grinding machine according to claim 27, wherein, The reference coordinate of the main shaft is configured as the zero coordinate of the main shaft.

34. The wafer grinding machine according to claim 27, wherein, The control device is further used for calibrating the reference coordinate of the main shaft before the first grinding operation for the grinding machine to control the movement of the main shaft based on the reference coordinate of the main shaft.

35. The wafer grinding machine according to claim 27, wherein, The control device is further used for determining and recording or outputting the wear amount of the grinding wheel based on the coordinate of the main shaft after correction and the coordinate before correction.

36. The wafer grinding machine according to claim 35, wherein, The control device is further used for determining the total wear amount of the grinding wheel as the sum of the wear amounts of the grinding wheel determined after each coordinate correction.

37. The wafer grinding machine according to claim 36, wherein, The control device is further used for sending a prompt message for replacing the grinding wheel when it is determined that the total wear amount of the grinding wheel reaches the disc replacement threshold.

38. The wafer grinding machine according to claim 35 or 36, wherein, It further includes a display device for displaying the wear amount of the grinding wheel and / or the total wear amount of the grinding wheel determined after each correction of the coordinates.

39. The wafer grinding machine according to claim 27, wherein, the control device is further configured to control the main shaft to continue to move based on the corrected coordinates for the next grinding operation.

40. The wafer grinding machine according to claim 27, wherein, the driving module includes: a driving component for connecting with the main shaft to drive the main shaft to move up and down at the processing station; a servo motor for drivingly connecting with the driving component to drive the driving component to drive the main shaft to move up and down at the processing station.

41. The wafer grinding machine according to claim 40, wherein, the encoder of the servo motor is an absolute encoder.

42. The wafer grinding machine according to claim 40, wherein, the driving module further includes a speed reducer connected to the servo motor and the driving component, and the speed reducer is used to reduce the output speed of the servo motor.

43. The wafer grinding machine according to claim 27, wherein, the grinding machine is a single-station grinding machine or a multi-station grinding machine.

44. A computer-readable storage medium, wherein, it stores at least one program, and the at least one program, when called, executes and implements the main shaft coordinate correction method according to any one of claims 1-15, or executes the grinding wheel wear amount detection method according to any one of claims 16-19, or executes the wafer grinding method according to any one of claims 20-26.

45. A computer device, wherein, it includes: a storage device for storing at least one program; a processing device connected to the storage device for calling the at least one program from the storage device and, when executed, implementing the main shaft coordinate correction method according to any one of claims 1-15, or executing the grinding wheel wear amount detection method according to any one of claims 16-19, or executing the wafer grinding method according to any one of claims 20-26.

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