Method for automatically positioning mechanical circle center of wafer pre-calibrator

Abstract

The invention discloses an automatic mechanical circle center positioning method for a wafer pre-calibrator, and the method comprises the steps: carrying out the parameter initialization of the wafer pre-calibrator, erasing the original parameters of the wafer pre-calibrator, and writing in preset reference parameters determined based on a product design drawing; enabling the circle center of the to-be-calibrated wafer to coincide with the circle center of a suction cup on the wafer pre-calibrator through the circle center calibration tool, and adsorbing the to-be-calibrated wafer through the suction cup; driving a rotating part of the wafer pre-calibrator to drive a suction cup to rotate, and collecting edge data of the to-be-calibrated wafer and rotation angle data of the rotating part through an edge detection part; processing the collected edge data and rotation angle data, regulating and controlling an X-axis moving part and a Y-axis moving part of the wafer pre-calibrator to carry out position adjustment according to the circle center coordinate of the fitting circle, and storing the mechanical circle center position parameter when the three parts coincide to a storage medium; and the wafer pre-calibrator is called during subsequent initialization to drive the suction cup circle center to return to the mechanical circle center. And the mechanical circle center can be automatically positioned without manual intervention.

Description

Technical Field

[0001] This application relates to the field of semiconductor equipment manufacturing technology, and in particular to an automatic positioning method for the mechanical center of a wafer pre-calibrator. Background Technology

[0002] In the semiconductor equipment manufacturing field, wafer pre-calibrators are one of the key pieces of equipment for achieving precise wafer processing. Their core function is to ensure that the center of the chuck coincides with the mechanical center by positioning the mechanical center, thereby guaranteeing the positional accuracy of the wafer during processing. As the requirements for efficiency and accuracy in semiconductor equipment continue to increase, the industry urgently needs to optimize the mechanical center positioning process of wafer pre-calibrators.

[0003] In related technologies, when the wafer center and the mechanical center are misaligned by too much, automatic and accurate calibration cannot be achieved. The wafer center and the chuck center must be aligned manually, which not only leads to low efficiency in the production and installation process, but also reduces product consistency due to the variability of manual operation, making it difficult to meet the application requirements of high precision and high stability of semiconductor equipment. Summary of the Invention

[0004] This application provides an automatic positioning method for the mechanical center of a wafer pre-calibrator, which can automatically position the mechanical center without manual intervention.

[0005] The technical solution of this application is as follows: This application provides an embodiment of an automatic positioning method for the mechanical center of a wafer pre-calibrator, including: The wafer pre-calibrator is initialized with parameters. After erasing its original parameters, a preset reference parameter determined based on the product design drawings is written. The preset reference parameter is a fuzzy position parameter that is close to the actual position of the mechanical center. The center of the wafer to be calibrated is made to coincide with the center of the chuck on the wafer precalibrator by using a center calibration fixture, and then the wafer to be calibrated is attracted by the chuck to limit the relative displacement between the two. The rotating component that drives the wafer pre-calibrator rotates the chuck, and simultaneously collects edge data of the wafer to be calibrated and rotation angle data of the rotating component through the edge detection component; The collected edge data and rotation angle data are processed, including calculating the derivatives of the two, screening and removing abnormal derivatives corresponding to wafer notches based on the Sigma anomaly detection principle, and then converting the remaining edge data to a rectangular coordinate system and fitting it into a circle using the least squares method to obtain the coordinates of the center of the fitted circle. Based on the coordinates of the center of the fitted circle, the X-axis and Y-axis moving parts of the wafer pre-calibrator are adjusted to make the center of the fitted circle, the center of the chuck, and the mechanical center coincide. The mechanical center position parameters when the three coincide are stored in the storage medium, and are called by the wafer pre-calibrator during subsequent initialization to drive the chuck center back to the mechanical center.

[0006] In a possible implementation, during parameter initialization, the preset reference parameters are parameters set according to the design drawings during the product design phase of the wafer pre-calibrator.

[0007] In a possible implementation, the suction cup generates an adsorption force to fix the wafer to be calibrated by opening an electromagnetic valve, and the vacuum pressure detection part of the wafer pre-calibrator monitors the adsorption pressure in real time to ensure that there is no relative displacement.

[0008] In a possible implementation, when the rotating component drives the suction cup to rotate, after the rotating component enters a state of uniform motion, the main controller of the wafer pre-calibrator starts a timer to collect edge data and rotation angle data according to the timing period and store the data in RAM.

[0009] In a possible implementation, the formula for calculating the derivative is: ; Where g(n) is the nth derivative value, l(n) is the nth edge sampling value, a(n) is the nth rotation angle value, l(n-1) is the (n-1)th edge sampling value, and a(n-1) is the (n-1)th rotation angle value.

[0010] In a possible implementation, when screening abnormal derivative values ​​based on the sigma anomaly detection principle, the derivative values ​​are fitted to a normal distribution, and derivative values ​​exceeding the 3sigma range are removed. The removed derivative values ​​are the abnormal data corresponding to the wafer notch.

[0011] In a possible implementation, before adjusting the position of the X-axis and Y-axis moving parts, if the offset between the center coordinates of the fitted circle and the theoretical position of the mechanical center exceeds 0.1 mm, the center calibration fixture is used again to make the wafer center coincide with the chuck center, and the subsequent steps are repeated until the offset does not exceed 0.1 mm.

[0012] In a possible implementation, when adjusting the X-axis moving component, the rotating component is first driven to rotate the wafer notch to the X-axis direction, and then the X-axis is moved to the positive limit and then slowly moved to the negative limit, while simultaneously collecting edge data; when the maximum value of the edge data is collected, the X-axis position corresponding to the maximum value is determined to be on the same straight line as the edge detection component, thus completing the X-axis positioning.

[0013] In a possible implementation, when adjusting the Y-axis moving component, the difference between the maximum value of the edge data and the center value of the edge detection component is calculated, and the difference is accumulated to the Y-axis encoder value. The Y-axis is then driven to move to the position corresponding to the accumulated value to complete the Y-axis positioning.

[0014] Secondly, this application also provides a computer device, the computer device including a processor and a memory, the memory storing a computer program, the processor being used to execute the computer program to implement the above-described automatic positioning mechanical centering method for a wafer pre-calibrator.

[0015] The embodiments of this application have the following beneficial effects: 1. Improve positioning accuracy: By eliminating gap interference data through Sigma anomaly detection, fitting circles using the least squares method, and controlling the accuracy threshold to 0.1mm, the positioning accuracy of the mechanical circle center is ensured to meet the high-precision requirements of semiconductor equipment. 2. Improve production efficiency: No manual alignment of the center is required, and the parameters can be reused for a long time after one calibration, avoiding repeated calibration processes and significantly shortening the installation and initialization time of the wafer pre-calibrator; 3. Ensure product consistency: By standardizing tooling alignment, data processing and parameter storage processes, the differences in manual operation are eliminated, ensuring that the mechanical center positioning results of different wafer pre-calibrators are consistent; 4. Reduced operational complexity: The entire process is automatically controlled by the main controller, eliminating the need for operators to have professional calibration skills, thus lowering the barrier to entry for using semiconductor equipment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and therefore should not be considered as a limitation on the scope of protection of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This paper shows an overall structural diagram of the wafer pre-calibrator according to an embodiment of the present application; Figure 2 This illustration shows the overall structure of the wafer pre-calibrator according to an embodiment of the present application, with the wafer mounted on it. Figure 3 This paper shows an overall structural diagram of the center calibration fixture according to an embodiment of this application; Figure 4 This paper presents an overall flowchart of the automatic positioning mechanical center method for a wafer pre-calibrator according to an embodiment of the present application; Figure 5 A data acquisition flowchart of the automatic positioning mechanical center method for a wafer pre-calibrator according to an embodiment of this application is shown; Figure 6 The original data processing flowchart of the automatic positioning mechanical center method of the wafer pre-calibrator according to an embodiment of this application is shown; Figure 7The flowchart illustrates the process of differentiating wafer edge sampling data and fitting the center in the automatic positioning mechanical center method of the wafer pre-calibrator according to an embodiment of this application. Figure 8 The flowchart illustrating the wafer mechanical center positioning verification and origin parameter storage process of the automatic positioning mechanical center method for the wafer pre-calibrator according to an embodiment of this application is shown.

[0018] Icons: 1. Wafer; 11. Wafer notch; 2. X-axis moving component; 3. Y-axis moving component; 4. Rotating component; 5. Anti-offset device; 6. Linear laser sensor; 7. Center calibration fixture. Detailed Implementation

[0019] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0020] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0022] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0023] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0024] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] This application discloses an automatic positioning method for the mechanical center of a wafer 1 pre-calibrator. The wafer 1 pre-calibrator includes an X-axis moving component 2, a Y-axis moving component 3, a rotating component 4, an anti-offset device 5, and a linear laser sensor 6. The wafer 1 is horizontally placed on the rotating component 4 and secured to its edge by multiple anti-offset devices 5. The X-axis moving component 2 and the Y-axis moving component 3 can respectively drive the rotating component 4 to move along the X-axis and Y-axis. The method includes the following steps: Step S1: Initialize the parameters of the pre-calibrator of wafer 1, erase its original parameters and write the preset reference parameters determined based on the product design drawings, wherein the preset reference parameters are fuzzy position parameters close to the actual position of the mechanical center. Step S2: The center of the wafer 1 to be calibrated is made to coincide with the center of the chuck on the pre-calibrator of wafer 1 by using the center calibration fixture 7, and then the wafer 1 to be calibrated is adsorbed by the chuck to limit the relative displacement between the two. Step S3: Drive the rotating component 4 of the pre-calibrator of wafer 1 to rotate the chuck, and simultaneously collect the edge data of the wafer 1 to be calibrated and the rotation angle data of the rotating component 4 through the edge detection component. Step S4: Process the collected edge data and rotation angle data, including calculating the derivative of both, screening and removing abnormal derivative values ​​corresponding to wafer notch 11 based on the Sigma anomaly detection principle, converting the remaining edge data to a rectangular coordinate system, fitting a circle using the least squares method, and obtaining the coordinates of the center of the fitted circle. Step S5: Based on the coordinates of the center of the fitted circle, adjust the position of the X-axis and Y-axis moving parts 3 of the wafer 1 pre-calibrator so that the center of the fitted circle, the center of the chuck, and the mechanical center coincide. Step S6: Store the mechanical center position parameters when the three coincide to the storage medium for use by the wafer 1 pre-calibrator during subsequent initialization to drive the chuck center back to the mechanical center.

[0026] In step S1, the core purpose of parameter initialization is to clear historical interference parameters, provide a unified reference starting point for subsequent calibration, and avoid positioning deviations caused by old parameters. Specifically, it also includes the following steps: Step S100: Erase Existing Parameters. The main controller of the wafer 1 pre-calibrator erases the historical mechanical center positioning parameters and related calibration data stored in its built-in storage unit. This operation eliminates any parameter deviations that may have remained from previous use of the equipment, ensuring that subsequent calibration processes start from an "interference-free reference" and avoiding the influence of historical data on the positioning accuracy.

[0027] Step S110: Write preset reference parameters. Write preset reference parameters, determined based on the product design drawings, into the memory (such as the RAM temporary storage area) of the wafer 1 pre-calibrator. These preset reference parameters are not the actual position of the mechanical center, but rather "fuzzy position parameters" set during the design phase based on theoretical dimensions. Their purpose is to provide an initial positioning basis close to the actual mechanical center for subsequent calibration, shortening the subsequent position adjustment travel and improving calibration efficiency.

[0028] In step S2, tooling and adsorption fixation are used to ensure that there is no relative displacement between wafer 1 and the chuck, providing a stable "reference carrier" for subsequent sampling and data processing. This also includes the following steps: In step S200, the tooling-assisted alignment center is achieved using a center calibration tooling 7 to adjust the geometric center of the wafer 1 to be calibrated to be completely aligned with the geometric center of the chuck on the pre-calibrator of wafer 1. This replaces the manual alignment in the prior art, ensuring alignment accuracy through the standardized structure of the tooling while avoiding random errors caused by manual operation.

[0029] In step S210, the electromagnetic valve of the pre-calibrator for controlling wafer 1 is opened, causing the chuck to generate a vacuum suction force, firmly fixing the wafer 1 to be calibrated onto the chuck. This limits the relative displacement between wafer 1 and the chuck during subsequent rotation and movement, ensuring that the edge data of wafer 1 collected later accurately reflects the position of the chuck and avoiding data distortion caused by displacement.

[0030] In step S3, by driving the chuck to rotate, edge data and rotation angle data of wafer 1 are collected simultaneously, providing sufficient and accurate raw data for subsequent calculation of the center of wafer 1. This also includes the following steps: Step S300: Start the rotating component 4 and enter a constant speed state. Drive the T-axis motor of the wafer 1 pre-calibrator to rotate the suction cup and the adsorbed wafer 1; after the T-axis motor speed stabilizes (enters a constant speed motion state), start data acquisition. This avoids the impact of speed fluctuations during the motor startup phase on data acquisition accuracy. During constant speed rotation, the relative motion pattern between the edge of wafer 1 and the linear laser sensor 6 is consistent, resulting in more stable edge data acquisition.

[0031] In step S310, the main controller of the wafer 1 pre-calibrator starts a timer to synchronously acquire edge data and rotation angle data. Based on a preset cycle time (e.g., microsecond-level period), it controls the linear laser sensor 6 to acquire edge data of wafer 1 and simultaneously acquires the rotation angle data of the T-axis motor (obtained by the encoder). Each acquired data point is stored in RAM in real time, with a total sampling count of several thousand to tens of thousands of points. By obtaining complete contour information of the wafer 1 edge through "multi-point sampling," a large amount of data can reduce the impact of random errors on subsequent circle fitting and improve the accuracy of wafer 1 center calculation.

[0032] In step S4, through multi-step data processing, interfering data (wafer notch 11) is removed and accurate coordinates of the center of wafer 1 are fitted, providing a core reference for subsequent position adjustments. Specifically, this also includes the following steps: Sub-step S400: Calculate the derivative of the edge data and the angle data. Calculate the derivative of each sampling point using the derivative formula: ; Where g(n) is the nth derivative value, l(n) is the nth edge sample value, a(n) is the nth rotation angle value, l(n-1) is the (n-1)th edge sample value, and a(n-1) is the (n-1)th rotation angle value. Wafer notch 11 is identified by the "data change rate." The edge data at wafer notch 11 undergoes abrupt changes, and the corresponding derivative value deviates significantly from the normal range, providing a basis for subsequent notch data removal.

[0033] Step S410: Based on Sigma anomaly detection, all derivative values ​​are fitted to a normal distribution to eliminate the notch data. According to the Sigma anomaly detection principle, derivative values ​​exceeding 3 sigma (i.e., abnormal derivative values) are screened and eliminated. The edge data associated with the abnormal derivative values ​​are the interference data corresponding to wafer notch 11. Since the notch is a non-functional structure of wafer 1, its data does not belong to the normal edge contour. Eliminating it ensures that the subsequently fitted circle can accurately reflect the actual geometric contour of wafer 1, thereby eliminating the influence of wafer notch 11 on the circle fitting.

[0034] Step S420: Edge data is converted to a Cartesian coordinate system. The remaining edge data after removing the gap data is converted from the polar coordinate system to the Cartesian coordinate system using trigonometric functions. This converts the discrete sampled data into Cartesian coordinate points that can be directly used for "circle fitting," providing a suitable data format for subsequent circle fitting using the least squares method.

[0035] Step S430: The least squares method is used to fit a circle and obtain the center coordinates. The edge data points in the rectangular coordinate system are fitted using the least squares method to calculate the center coordinates of the fitted circle (i.e., the actual center coordinates of the wafer 1 to be calibrated). By extracting the geometric center of wafer 1 from a large amount of discrete data using mathematical algorithms, the least squares method effectively reduces the impact of sampling errors, ensuring the accuracy of the fitted circle's center coordinates and providing an accurate reference for subsequent adjustments to the positions of the chuck and mechanical center.

[0036] In step S5, by precisely adjusting the X and Y axis positions, the three points of "fitting circle center (wafer 1 center), chuck center, and mechanical center" are aligned, thus completing the positioning of the mechanical center. This also includes the following steps: In sub-step S500, the center offset of the fitted circle is determined by comparing the coordinates of the fitted circle center obtained in step S430 with the theoretical position of the mechanical center (the mechanical center is 614mm away from the linear laser sensor and is collinear). The offset is checked to see if it exceeds 0.1mm (the allowable mechanical error). If the offset exceeds 0.1mm, the process returns to step S200 to re-execute the tooling alignment and subsequent procedures until the offset is ≤0.1mm. This ensures that the final positioned mechanical center meets the high-precision requirements of the semiconductor equipment and avoids positioning failures due to data errors.

[0037] Step S510: X-axis positioning adjustment first drives the T-axis motor to rotate the wafer notch 11 to the positive X-axis direction (ensuring a unified X-axis adjustment reference); then drives the X-axis moving component 2 to move the X-axis to the positive limit, and then controls the X-axis to slowly move to the negative limit, simultaneously acquiring edge data through the linear laser sensor 6; when the acquired edge data reaches a maximum value, it is determined that the X-axis encoder position corresponding to this maximum value is on the same straight line as the linear laser sensor 6, and the X-axis movement is stopped, completing the X-axis positioning. The accurate position of the X-axis is determined by the "maximum value of edge data," at which point the X-axis position exactly matches the X-axis coordinate of the mechanical center.

[0038] Step S520: The difference between the maximum value of the edge data collected in step S510 and the center value of the linear laser sensor 6 is calculated for Y-axis positioning adjustment. This difference is accumulated to the current value of the Y-axis encoder, and the Y-axis moving component 3 is driven to move the Y-axis to the position corresponding to the accumulated value, thus completing the Y-axis positioning. Through "sensor center value deviation compensation", the Y-axis position is matched with the Y-axis coordinate of the mechanical center, ultimately achieving complete spatial overlap between the center of the fitted circle, the center of the suction cup, and the mechanical center.

[0039] In step S6, by storing positioning parameters, the long-term preservation and automatic reuse of the mechanical center position are achieved, improving the efficiency of subsequent equipment use. Specifically, this also includes the following steps: Step S600: Store the mechanical center position parameters. The mechanical center position parameters (X-axis and Y-axis coordinate values) at the "three points coincide" point in step S5 are stored in the Flash memory of the wafer 1 pre-calibrator. This ensures long-term stable storage of parameters, preventing parameter loss due to power failure and ensuring that subsequent recalibration is unnecessary.

[0040] In step S610, during initialization, the parameters of the pre-calibrator for wafer 1 are automatically called. Each time the initialization process is started subsequently, the main controller automatically retrieves the stored mechanical center position parameters from the Flash memory, driving the X-axis and Y-axis moving parts 3 to move the suction cup center to the position corresponding to these parameters, causing the suction cup center to automatically return to the mechanical center. This achieves "one-time calibration, multiple uses," replacing the manual alignment process of existing technologies and significantly improving equipment initialization efficiency and product consistency.

[0041] The above technical solutions can achieve the following technical effects: 1. Improve positioning accuracy: By eliminating gap interference data through Sigma anomaly detection, fitting circles using the least squares method, and controlling the accuracy threshold to 0.1mm, the positioning accuracy of the mechanical circle center is ensured to meet the high-precision requirements of semiconductor equipment. 2. Improve production efficiency: No manual alignment of the center is required, and the parameters can be reused for a long time after one calibration, avoiding repeated calibration processes and significantly shortening the installation and initialization time of the wafer 1 pre-calibrator; 3. Ensure product consistency: By standardizing tooling alignment, data processing and parameter storage processes, the differences in manual operation are eliminated, ensuring that the mechanical center positioning results of different wafer 1 pre-calibrators are consistent; 4. Reduced operational complexity: The entire process is automatically controlled by the main controller, eliminating the need for operators to have professional calibration skills, thus lowering the barrier to entry for using semiconductor equipment.

[0042] It is understood that the apparatus in this embodiment corresponds to the automatic positioning mechanical center method of the wafer pre-calibrator in the above embodiment. The options in the above embodiment are also applicable to this embodiment, so they will not be described again here.

[0043] This application also provides a computer device, exemplary of which includes a processor and a memory, wherein the memory stores a computer program, and the processor, by running the computer program, causes the computer device to perform the above-described automatic positioning mechanical centering method for a wafer pre-calibrator or the functions of the various modules in the above-described wafer pre-calibrator.

[0044] The processor can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, including at least one of a Central Processing Unit (CPU), Graphics Processing Unit (GPU), Network Processor (NP), Digital Signal Processor (DSP), Application-Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application.

[0045] The memory can be, but is not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), etc. The memory is used to store computer programs, and the processor can execute the computer programs accordingly after receiving execution instructions.

[0046] This application also provides a computer-readable storage medium for storing the computer program used in the aforementioned computer device. For example, the computer-readable storage medium may include, but is not limited to, various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0047] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that, in alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0048] In addition, the functional modules or units in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0049] If the aforementioned functions are implemented as software functional modules 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 portion of the 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 to cause a computer device (which may be a smartphone, personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0050] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for automatically positioning the mechanical center of a wafer pre-calibrator, characterized in that, include: The wafer pre-calibrator is initialized with parameters. After erasing its original parameters, a preset reference parameter determined based on the product design drawings is written. The preset reference parameter is a fuzzy position parameter that is close to the actual position of the mechanical center. The center of the wafer to be calibrated is made to coincide with the center of the chuck on the wafer precalibrator by using a center calibration fixture, and then the wafer to be calibrated is attracted by the chuck to limit the relative displacement between the two. The rotating component that drives the wafer pre-calibrator rotates the chuck, and simultaneously the edge detection component collects the edge data of the wafer to be calibrated and the rotation angle data of the rotating component. The collected edge data and rotation angle data are processed, including calculating the derivatives of the two, screening and removing abnormal derivatives corresponding to wafer notches based on the Sigma anomaly detection principle, and then converting the remaining edge data to a rectangular coordinate system and fitting it into a circle using the least squares method to obtain the coordinates of the center of the fitted circle. Based on the coordinates of the center of the fitted circle, the X-axis and Y-axis moving parts of the wafer pre-calibrator are adjusted to make the center of the fitted circle, the center of the chuck, and the mechanical center coincide. The mechanical center position parameters when the three coincide are stored in the storage medium, and are called by the wafer pre-calibrator during subsequent initialization to drive the chuck center back to the mechanical center.

2. The automatic positioning mechanical center method for a wafer pre-calibrator according to claim 1, characterized in that, In the parameter initialization, the preset reference parameters are parameters set according to the design drawings during the product design phase of the wafer pre-calibrator.

3. The automatic positioning mechanical center method for a wafer pre-calibrator according to claim 1, characterized in that, The suction cup generates an adsorption force by opening an electromagnetic valve to fix the wafer to be calibrated. The vacuum pressure detection part of the wafer pre-calibrator monitors the adsorption pressure in real time to ensure that there is no relative displacement.

4. The automatic positioning method for the mechanical center of a wafer pre-calibrator according to claim 1, characterized in that, When the drive rotating component rotates the suction cup, after the rotating component enters a uniform motion state, the main controller of the wafer pre-calibrator starts the timer, collects edge data and rotation angle data according to the timing period, and stores the data in RAM.

5. The automatic positioning method for the mechanical center of a wafer pre-calibrator according to claim 1, characterized in that, The formula for calculating the derivative is: ; Where g(n) is the nth derivative value, l(n) is the nth edge sampling value, a(n) is the nth rotation angle value, l(n-1) is the (n-1)th edge sampling value, and a(n-1) is the (n-1)th rotation angle value.

6. The automatic positioning method for the mechanical center of a wafer pre-calibrator according to claim 1, characterized in that, When screening abnormal derivative values ​​based on the sigma anomaly detection principle, the derivative values ​​are fitted to a normal distribution, and derivative values ​​exceeding the 3sigma range are removed. The removed derivative values ​​are the abnormal data corresponding to wafer notches.

7. The automatic positioning mechanical center method for a wafer pre-calibrator according to claim 1, characterized in that, Before adjusting the position of the X-axis and Y-axis moving parts, if the offset between the center coordinates of the fitted circle and the theoretical position of the mechanical center exceeds 0.1mm, the center calibration fixture is used again to make the wafer center coincide with the chuck center, and the subsequent steps are repeated until the offset does not exceed 0.1mm.

8. The automatic positioning method for the mechanical center of a wafer pre-calibrator according to claim 1, characterized in that, When adjusting the X-axis moving component, first drive the rotating component to rotate the wafer notch to the X-axis direction, then move the X-axis to the positive limit and then slowly move it to the negative limit, simultaneously collecting edge data; when the maximum value of the edge data is collected, determine that the X-axis position corresponding to the maximum value is on the same straight line as the edge detection component, and complete the X-axis positioning.

9. The automatic positioning method for the mechanical center of a wafer pre-calibrator according to claim 8, characterized in that, When adjusting the Y-axis moving component, the difference between the maximum value of the edge data and the center value of the edge detection component is calculated. This difference is accumulated into the Y-axis encoder value, and the Y-axis is driven to move to the position corresponding to the accumulated value to complete the Y-axis positioning.

10. A computer device, characterized in that, The computer device includes a processor and a memory, the memory storing a computer program, and the processor executing the computer program to implement the automatic positioning mechanical centering method for the wafer pre-calibrator according to any one of claims 1-9.

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