A method for measuring distance and positioning semiconductor products based on magnetic encoder

Abstract

The invention belongs to the field of positioning and distance measurement, and specifically relates to a semiconductor product distance measurement and positioning method based on a magnetic encoder. By simultaneously installing an absolute magnetic encoder and an incremental magnetic encoder on a semiconductor manufacturing platform, the absolute magnetic encoder provides absolute position data, provides a stable reference position for the incremental magnetic encoder, avoids a zero return operation, and can verify the consistency of the positioning data of the absolute encoder and the incremental encoder, which is helpful to identify and detect potential positioning errors, thereby making targeted positioning adjustments, greatly reducing the error risk and fault diagnosis difficulty of the system. At the same time, before using the absolute magnetic encoder and the incremental magnetic encoder for distance measurement and positioning, the absolute magnetic encoder and the incremental magnetic encoder are installed and tested, and installation adjustments are made based on the installation test results, so that measurement inaccuracies caused by installation errors can be minimized, thereby improving the overall measurement accuracy of the system.

Description

Technical Field

[0001] The invention belongs to the field of positioning and ranging, and in particular relates to a semiconductor product ranging and positioning method based on a magnetic encoder. Background Art

[0002] Precise positioning is the key in the semiconductor manufacturing process. However, the semiconductor manufacturing environment is often dusty, oily, and chemically corroded. Traditional positioning equipment is easily affected by these harsh environments, resulting in poor positioning results. In this case, the magnetic encoder has good environmental adaptability and uses magnetic field changes for positioning, providing contactless measurement, which greatly reduces mechanical wear and becomes a commonly used positioning device in the semiconductor manufacturing process.

[0003] Generally speaking, magnetic encoders are divided into two types: incremental and absolute. Due to the high positioning accuracy requirements in the semiconductor manufacturing process, and the ability of incremental magnetic encoders to provide high-resolution position information, incremental magnetic encoders have become widely used magnetic encoders in semiconductor manufacturing. However, incremental magnetic encoders measure relative positions and need to be used in conjunction with the starting position, which means that the incremental magnetic encoder needs to be reset to zero every time it is powered on, which may result in additional time costs and complexity in a highly integrated automation environment.

[0004] In order to solve this problem, the Chinese invention patent with the existing authorization announcement number CN105099291B discloses a magnetic encoder and a motor. The invention takes into account that the magnetic encoder cannot maintain the correlation between its zero point and the electromotive force of the motor. Therefore, by providing a register, a corrector connected to the register, and an external interface connected to the corrector, the zero point position parameters of the motor are pre-stored in the register for use by the corrector. It can be seen from the invention that by pre-storing the zero point position information in the register, the system can read the data in the register to restore to the last state after each power-on without re-zeroing. However, this method can only provide positioning data of a single data source for the incremental encoder, and cannot effectively detect and correct the cumulative errors and sensitive errors to harsh environments in the positioning process of the incremental encoder. At the same time, once a positioning error or data deviation occurs, the system lacks additional data sources to help diagnose the root cause of the problem, which invisibly increases the error risk and fault diagnosis difficulty of the system.

[0005] In addition, the existing technology lacks attention to encoder installation detection when using magnetic encoders for distance measurement and positioning, which is prone to installation accuracy problems. The installation accuracy of the encoder directly affects the quality of the signal. Installation errors may cause noise or interference in the magnetic signal generated by the encoder, thereby affecting the accuracy and reliability of the data. More importantly, when installation accuracy problems occur, the encoder may require more frequent maintenance and adjustments. This not only increases maintenance costs, but may also cause equipment downtime and affect production efficiency. Summary of the invention

[0006] To this end, one purpose of an embodiment of the present application is to provide a semiconductor product ranging and positioning method based on a magnetic encoder. By combining an incremental magnetic encoder with an absolute encoder for ranging and positioning, and performing installation detection and adjustment after installation, it can not only solve the problem that the incremental encoder needs to be reset to zero every time it is powered on, but also realize positioning verification.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A semiconductor product ranging and positioning method based on a magnetic encoder comprises the following steps: installing a first magnetic encoder and a second magnetic encoder on a semiconductor manufacturing platform, wherein the first magnetic encoder is an absolute encoder and the second magnetic encoder is an incremental encoder.

[0008] After installation, the encoder shaft and drive shaft are inspected for installation, including centering inspection and installation stability inspection.

[0009] Perform distance measurement installation adjustments based on the installation detection results.

[0010] After the ranging installation is adjusted, the first magnetic encoder is used to measure the distance and position the semiconductor product, and at the same time, an environmental collection terminal set on the semiconductor manufacturing platform is used to collect environmental information, wherein the environmental information includes temperature, humidity, vibration displacement and electromagnetic interference noise frequency.

[0011] The first magnetic encoder positioning data is stored and processed based on the collected environmental information.

[0012] Based on the storage processing of the positioning data of the first magnetic encoder, the second magnetic encoder is used to measure the distance and position the semiconductor product to obtain the positioning data of the second magnetic encoder.

[0013] After each ranging and positioning, the positioning data of the second magnetic encoder and the first magnetic encoder are judged for positioning consistency, and the dominant positioning data is determined when it is judged that there is a positioning deviation.

[0014] A positioning cycle is set, and then the positioning data of the first magnetic encoder and the positioning data of the second magnetic encoder obtained from each ranging positioning within the positioning cycle are retrieved to construct a positioning change curve.

[0015] The positioning change curve of the first magnetic encoder is overlapped and compared with the positioning change curve of the second magnetic encoder, thereby evaluating the positioning quality.

[0016] Make positioning adjustments based on the positioning quality evaluation results.

[0017] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: 1. By simultaneously installing an absolute magnetic encoder and an incremental magnetic encoder on a semiconductor manufacturing platform, the present invention uses the absolute magnetic encoder to provide absolute position data, provides a stable reference position for the incremental magnetic encoder, avoids the zeroing operation, and can simultaneously verify the consistency of the positioning data of the absolute encoder and the incremental encoder, which helps to identify and detect potential positioning errors, thereby making targeted positioning adjustments, greatly reducing the system's error risk and fault diagnosis difficulty. This combination method can effectively improve the overall performance and reliability of the system.

[0018] 2. The present invention pays attention to the installation accuracy of the magnetic encoder by performing installation inspection on the absolute magnetic encoder and the incremental magnetic encoder before using them for distance measurement and positioning, and performs installation adjustment based on the installation inspection result. Therefore, the installation adjustment can minimize the measurement inaccuracy caused by installation errors, thereby improving the overall measurement accuracy of the system. At the same time, correct installation and adjustment can reduce the failure rate of the equipment caused by encoder installation problems, reduce the maintenance and repair requirements of the equipment, and help improve production efficiency.

[0019] 3. The present invention takes into account the influence of high temperature, high humidity and other environmental encoder positioning, collects environmental information to evaluate environmental suitability while using the absolute magnetic encoder for positioning, and directly uses the positioning position of the absolute magnetic encoder as the reference position of the incremental magnetic encoder when the environment is suitable, and stores the positioning position in the register; when the environment is not suitable, the positioning position closest to the current moment is extracted from the register as the reference position of the incremental magnetic encoder, which helps the incremental encoder to obtain accurate reference during initialization regardless of whether there is interference in the environment, so as to maximize the overall performance and robustness of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0021] Figure 1 The present invention is a flowchart of the steps for implementing the method.

[0022] Figure 2 It is a schematic diagram for comparing the coincidence of the central axes corresponding to the encoder shaft and the drive shaft in the present invention.

[0023] Figure 3 This is a schematic diagram of the alignment of characteristic points on the positioning change curves of the first and second magnetic encoders.

[0024] Description of the drawings: A——encoder shaft, B——drive shaft, 1——positioning change curve of the first magnetic encoder, 2——positioning change curve of the second magnetic encoder. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 As shown, the present invention proposes a semiconductor product ranging and positioning method based on a magnetic encoder, comprising the following steps: installing a first magnetic encoder and a second magnetic encoder on a semiconductor manufacturing platform, wherein the first magnetic encoder is an absolute encoder and the second magnetic encoder is an incremental encoder.

[0027] After installation, the encoder shaft and drive shaft are inspected for installation, including centering inspection and installation stability inspection.

[0028] It is important to know that the magnetic encoder is installed on the semiconductor manufacturing platform through the drive shaft. This is because the drive shaft is usually directly connected to the moving part to be measured (such as a motor). The encoder directly installed on the drive shaft can more accurately measure the rotational position of the drive shaft. This ensures the consistency between the encoder reading and the actual movement and improves the measurement accuracy. In addition, installing the encoder through the drive shaft can reduce the error caused by the transmission device (such as gears, pulleys, etc.). The transmission device may introduce mechanical errors or delays. The encoder directly installed on the drive shaft can avoid these potential problems.

[0029] In a preferred implementation of the above scheme, the centering detection is performed as follows: a central axis is constructed with the encoder shaft and the drive shaft as the center at the installation positions of the first magnetic encoder and the second magnetic encoder, respectively, to obtain the central axis corresponding to the encoder shaft and the drive shaft.

[0030] Align the center axes of the encoder shaft and drive shaft for comparison. Figure 2 As shown, identify whether the central axes of the two intersect. If they intersect, the angle between the central axes of the two is obtained, where the angle ranges from 0 to 90°. Then, the cosine value of the angle between the central axes of the two is calculated and the percentage is taken to obtain the alignment conformity of the encoder. If they do not intersect, it means that the central axes of the two are parallel. Then measure the distance between the central axes of the two, and then use the formula The centering compliance of the encoder is obtained, wherein the reference distance is used to eliminate the dimension and assist in the calculation of the centering compliance. Exemplarily, the reference distance is 1 cm.

[0031] It should be understood that after the magnetic encoder is installed, the alignment test of the encoder shaft and the drive shaft can reduce the error caused by poor shaft alignment. If the encoder shaft and the drive shaft are not aligned, additional axial and radial loads may be introduced, resulting in inaccurate encoder readings. At the same time, the misaligned shaft will cause mechanical friction and wear, accelerating the damage of components. Alignment detection can ensure smooth docking between the two, thereby reducing friction. Furthermore, by using the alignment comparison method of the encoder shaft and the drive shaft center axis, the actual alignment of the encoder shaft and the drive shaft can be directly measured. Compared with the use of indirect measurement tools (such as optical alignment instruments, laser alignment instruments, etc.), the axis alignment comparison method reduces the errors that may be introduced by other measurement tools. Since it directly reflects the actual alignment state of the shaft, it ensures the accuracy of the measurement. At the same time, the operation of axis alignment comparison is relatively simple, usually only requiring an alignment mark or indicator to observe the alignment of the axis. This method does not require complex equipment or additional tools, making the alignment process more intuitive and operational.

[0032] In another preferred implementation of the above scheme, the installation stability is detected in the following process: one measuring surface of the measuring scale is fixed on the encoder shaft and the other measuring surface is fixed on the drive shaft at the installation positions of the first magnetic encoder and the second magnetic encoder respectively.

[0033] It should be added that when using a measuring ruler to fix it, it is necessary to ensure that the measuring ruler is perpendicular to the axis of the shaft and that the two measuring surfaces are in close contact. In actual operation, appropriate pressure can be applied to ensure that the measuring surface of the measuring ruler is in good contact with the shaft surface.

[0034] As an example of a measuring ruler, the measuring ruler may be an axial vernier ruler or a micrometer.

[0035] Read the measured value on the measuring tape to obtain the axial clearance between the encoder shaft and the drive shaft, and compare it with the installation standard, where the installation standard is specified in the encoder installation document. The installation stability of the encoder is obtained by constructing an exponential function with the reciprocal of the natural constant as the base, the difference between the axial clearance and the installation standard divided by the absolute value of the installation standard as the exponent, and then taking the percentage.

[0036] It should be explained that, although the smaller the axial clearance, the less likely the encoder shaft and the drive shaft are to loosen, vibrate, or fall off during operation, the better the installation stability, and the better it helps to reduce friction and wear caused by the clearance, extend the service life of the shaft and bearings, and reduce failures caused by shaft offset, but over-tightening may cause excessive bearing load or other mechanical problems. Therefore, the present invention uses the absolute value of the difference between the axial clearance and the installation standard when calculating the installation stability using the axial clearance, taking into account that the axial clearance cannot be too large or too small.

[0037] The present invention can quickly obtain the result by measuring the axial clearance between the encoder shaft and the drive shaft to detect the installation stability, so that the operator can quickly judge the installation status and make timely adjustments when problems are found. Instant feedback helps to improve the efficiency of installation and maintenance. Compared with the detection method that requires high-precision optical or laser equipment, the axial clearance measurement usually requires less equipment, thereby reducing the cost and complexity of the detection.

[0038] The ranging installation adjustment is performed based on the installation detection result, and the specific implementation is as follows: the alignment conformity and installation stability corresponding to the first magnetic encoder and the second magnetic encoder are compared with the preset standard conformity and standard stability, respectively, wherein the standard conformity and standard stability can be extracted from the encoder installation file. Exemplarily, the standard conformity and standard stability can be 90%. If the alignment conformity or installation stability corresponding to a certain magnetic encoder does not meet the standard conformity and standard stability, it is identified that the ranging installation adjustment needs to be performed, and the installation adjustment object and the installation adjustment direction are determined therefrom. Exemplarily, when the alignment conformity corresponding to the first magnetic encoder does not meet the standard conformity, the installation adjustment object is the first magnetic encoder, and the installation adjustment direction is the adjustment shaft alignment.

[0039] In another example, when the installation stability corresponding to the second magnetic encoder does not meet the standard stability, the installation adjustment object is the second magnetic encoder, and the installation adjustment direction is to adjust the shaft clearance.

[0040] Perform distance measurement installation adjustment according to the installation adjustment object and installation adjustment direction.

[0041] The present invention performs installation inspection on the installed magnetic encoder by detecting the centering and installation stability. On the one hand, the comprehensiveness of the detection of the installation performance of the magnetic encoder can be improved. On the other hand, the double detection can clearly identify the specific location of the centering problem or the stability problem, provide a precise adjustment direction, and help improve the installation and adjustment efficiency of the magnetic encoder.

[0042] After the ranging installation and adjustment, the first magnetic encoder is used to measure the distance and position the semiconductor product in operation, and at the same time, the environment collection terminal set on the semiconductor manufacturing platform is used to collect environmental information, wherein the environmental information includes temperature, humidity, vibration displacement and electromagnetic interference noise frequency.

[0043] The above-mentioned environment collection terminal is a device for collecting environmental information such as temperature, humidity, vibration displacement and electromagnetic interference noise frequency. Specifically, it can be an integrated device of temperature and humidity sensors, vibration sensors, and electromagnetic interference detectors.

[0044] Based on the collected environmental information, the storage and processing of the first magnetic encoder positioning data is specifically implemented as follows: the specification model of the first magnetic encoder is obtained, thereby obtaining the suitable environmental information of the first magnetic encoder in the working state, which can be specifically obtained from the instructions for use of the magnetic encoder, and the collected environmental information is compared with the suitable environmental information, and the analysis formula is used to calculate the storage and processing of the first magnetic encoder positioning data. The environmental suitability ES corresponding to the first magnetic encoder is obtained, where T, D, X, and f respectively represent the temperature, humidity, vibration displacement, and electromagnetic interference noise frequency of the first magnetic encoder, and T0, D0, X0, and f0 respectively represent the suitable temperature, suitable humidity, suitable vibration displacement, and suitable electromagnetic interference noise frequency of the first magnetic encoder in a working state.

[0045] It should be understood that the temperature, humidity, vibration displacement and electromagnetic interference noise frequency are selected as environmental parameters in the environmental information of the magnetic encoder because these environmental parameters have an important impact on the operating quality and life of the magnetic encoder, which is specifically reflected in: temperature changes will affect the material properties of the magnetic encoder, the performance of the electronic components and the stability of the magnetic field. Too high or too low temperature may cause the encoder to lose accuracy or even damage; too high humidity may cause corrosion of the internal components of the encoder or degradation of the insulating material, affecting the electrical performance and life of the encoder; too low humidity is prone to static electricity accumulation, which may cause electrostatic discharge, interfere with the electronic components of the encoder or cause data loss; vibration may cause the mechanical parts of the encoder to shift or loosen, affecting its accuracy and stability; electromagnetic interference may interfere with the encoder's signal, resulting in measurement errors or data loss. Taking temperature, humidity, vibration displacement and electromagnetic interference noise frequency as environmental parameters, the environmental suitability of the magnetic encoder can be comprehensively evaluated.

[0046] The real-time positioning data of the first magnetic encoder and the environmental suitability are formed into a mapping data group and stored in a register, and a time stamp is added to each mapping data group.

[0047] The environmental suitability corresponding to the first magnetic encoder is compared with the suitability threshold, wherein the suitability threshold refers to the minimum environmental suitability for the magnetic encoder to maintain normal operation, which can be obtained from the instructions for use of the magnetic encoder. Exemplarily, the suitability threshold can be 0.8. If the environmental suitability corresponding to the first magnetic encoder reaches the suitability threshold at a certain moment, the mapping data group corresponding to that moment is marked as valid in the register.

[0048] The storage space of the register is detected in real time to identify whether the storage is limited, and if the storage is limited, the mapping data group is updated and stored. The specific update can be carried out by eliminating outdated mapping data groups, such as mapping data groups with time stamps far away from now.

[0049] Based on the storage processing of the positioning data of the first magnetic encoder, the second magnetic encoder is used to measure the distance and position the semiconductor product to obtain the positioning data of the second magnetic encoder.

[0050] Preferably, the above scheme implements the ranging and positioning of the semiconductor product by the second magnetic encoder based on the storage and processing of the positioning data of the first magnetic encoder as follows: the positioning data and environmental suitability of the first magnetic encoder are acquired in real time, and the environmental suitability is compared with the suitability threshold. If the environmental suitability of the first magnetic encoder reaches the suitability threshold at a certain moment, the positioning data of the first magnetic encoder at that moment is used as the reference position of the second magnetic encoder. Otherwise, based on the current moment, the mapping data group closest to the current moment and with a valid data mark is extracted from the register, and the positioning data of the first magnetic encoder in the extracted mapping data group is used as the reference position.

[0051] The semiconductor product is positioned and measured based on the reference position of the second magnetic encoder.

[0052] The present invention simultaneously installs an absolute magnetic encoder and an incremental magnetic encoder on a semiconductor manufacturing platform, wherein the absolute magnetic encoder provides absolute position data and provides a stable reference position for the incremental magnetic encoder, thereby avoiding a zero return operation. In this way, the operation can be quickly restored when the system is started or after a fault occurs, without the need to recalibrate the position.

[0053] After each ranging and positioning, the positioning data of the second magnetic encoder are compared with the positioning data of the first magnetic encoder for positioning consistency, and the dominant positioning data is determined when it is judged that there is a positioning deviation.

[0054] As a further implementation of the above scheme, the positioning consistency judgment is performed as follows: the positioning data of the second magnetic encoder is compared with the positioning data of the first magnetic encoder to calculate the positioning difference, and compared with the preset allowable positioning difference. If the positioning difference is less than or equal to the allowable positioning difference, the positioning is judged to be consistent, otherwise the positioning is judged to be biased.

[0055] It should be emphasized that since the positioning data types of absolute magnetic encoders and incremental magnetic encoders are different, the data of the incremental encoder needs to be converted into absolute position before positioning consistency judgment can be compared with the data of the absolute encoder.

[0056] Furthermore, the dominant positioning data is determined as follows: the environmental suitability of the positioning data provided by the first magnetic encoder is extracted from the register, and at the same time, the power supply information, including the power supply voltage and the power supply current, is extracted from the power supply end of the second magnetic encoder, and the power supply fluctuation is calculated by comparing with the power supply information at the previous moment. The specific calculation formula is: Where U and I represent the supply voltage and supply current respectively, U 上 ,I 上They represent the supply voltage and current at the previous moment respectively, and e represents a natural constant.

[0057] The environmental suitability of the positioning data provided by the first magnetic encoder and the power supply fluctuation of the positioning data provided by the second magnetic encoder are compared with the suitability threshold and the fluctuation threshold respectively. The judgment result R of whether there is dominant positioning data is obtained. In the model, R=1 indicates that there is dominant positioning data, R=0 indicates that there is no dominant positioning data, P=P1 indicates that the dominant positioning data is the positioning data provided by the first magnetic encoder, P=P2 indicates that the dominant positioning data is the positioning data provided by the second magnetic encoder, PF indicates the power supply fluctuation degree of the second magnetic encoder providing the positioning data, ∧ indicates the difference with, ES t , PT t They represent the suitability threshold and volatility threshold respectively.

[0058] The above-mentioned medium fluctuation threshold refers to the minimum power supply fluctuation for the magnetic encoder to maintain normal operation, which can be obtained from the instructions for use of the magnetic encoder. Exemplarily, the fluctuation threshold is 0.8.

[0059] When it is determined that there is no dominant positioning data, the first magnetic encoder and the second magnetic encoder are re-measured and positioned.

[0060] It should be added that since the incremental magnetic encoder counts by sending out pulse signals, it contains an oscillation circuit inside, and the fluctuation of the power supply voltage may cause the instability of the oscillation frequency, thereby affecting the accuracy and frequency of the pulse. Therefore, when the absolute magnetic encoder and the incremental magnetic encoder have inconsistent positioning, by analyzing the environmental suitability of the absolute magnetic encoder and the power supply fluctuation of the incremental magnetic encoder, it can be determined which encoder's data is more reliable, thereby optimizing the positioning and operational stability of the system.

[0061] It needs to be explained that in the dominant positioning data evaluation model, when the environmental suitability reaches the suitability threshold and the power supply fluctuation is less than the fluctuation threshold, the positioning data provided by the absolute magnetic encoder is still selected as the dominant positioning data because the absolute magnetic encoder can provide real-time and accurate absolute position data, which is not affected by cumulative errors, ensuring that the system can accurately know the position at any point in time. Incremental encoders are prone to error accumulation due to long-term operation. Even if the power supply is stable, errors may gradually accumulate, thereby affecting the accuracy of their data.

[0062] A positioning cycle is set, and then the positioning data of the first magnetic encoder and the positioning data of the second magnetic encoder obtained from each ranging positioning within the positioning cycle are retrieved to construct a positioning change curve in a coordinate system with time as the horizontal axis and positioning data as the vertical axis.

[0063] It should be noted that in order to ensure the consistency of the units of the positioning change curve, the positioning data of the incremental magnetic encoder obtained within the positioning cycle needs to be converted into absolute positions to construct the positioning change curve.

[0064] The positioning period in the above-mentioned setting can be set to 3 months, half a year, etc. The purpose of setting is to systematically collect data so that the positioning data of the two magnetic encoders can be accurately compared and analyzed within a fixed time range, which is helpful for periodically identifying positioning defects and making targeted adjustments.

[0065] The positioning change curve of the first magnetic encoder is overlapped and compared with the positioning change curve of the second magnetic encoder, thereby evaluating the positioning quality. Specifically, the evaluation process is as follows:

[0066] Characteristic points are marked on the positioning change curves of the first magnetic encoder and the second magnetic encoder respectively, wherein the characteristic points may be peak points and valley points, and the marked characteristic points are numbered in order from front to back on the positioning change curves.

[0067] Based on the same numbering principle, the characteristic points marked on the positioning change curves of the first magnetic encoder and the second magnetic encoder are aligned into groups, see Figure 3 shown.

[0068] The time points of the characteristic points in each alignment group on the positioning change curves of the first magnetic encoder and the second magnetic encoder are respectively obtained, and the positioning time differences corresponding to each alignment group are obtained by subtracting the time points.

[0069] The positioning response timeliness is evaluated based on the positioning time difference corresponding to each alignment group. The specific process is to compare the positioning time difference corresponding to each alignment group with the set ideal positioning time difference, and then use the expression Where Δt i represents the positioning time difference of the i-th alignment group, i represents the alignment group number, i=1,2,...,n, n represents the number of alignment groups, Δt′ represents the ideal positioning time difference, wherein the ideal positioning time difference depends on the positioning requirements of the semiconductor manufacturing platform, illustratively, the ideal positioning time difference can be 2ms.

[0070] It is important to know that since the incremental magnetic encoder relies on the reference position provided by the absolute encoder to determine its absolute position, when the system is running, the incremental encoder calculates the current position by counting its pulses. This process may cause time asynchrony with the position data of the absolute encoder, resulting in a time difference. When comparing the positioning change curve of the absolute magnetic encoder with the positioning change curve of the incremental magnetic encoder, the positioning response evaluation is performed by selecting the time interval between the peak points and valley points, because the peak points and valley points are important change points that can effectively identify the curve. Using them as feature points allows the comparison process to more accurately analyze the response differences of the two encoders in positioning changes.

[0071] A number of time points are uniformly selected on the horizontal axis corresponding to the positioning change curve, and the positioning data of each time point on the positioning change curve of the first magnetic encoder and the second magnetic encoder are extracted to obtain the positioning deviation corresponding to each time point.

[0072] A deviation curve is drawn based on the positioning deviation corresponding to each time point, and the deviation change trend is extracted from the deviation curve. The deviation change trend can be obtained by obtaining the tangent slope corresponding to each time point on the deviation curve and using the difference or differential method to calculate the deviation curve change rate as the deviation change trend.

[0073] The mean absolute deviation and root mean square deviation of the positioning deviation corresponding to each time point are calculated. Generally speaking, the root mean square deviation is more sensitive to large deviations because the square operation will amplify large deviations, which makes the root mean square deviation more sensitive to outliers. It is suitable for situations where large deviations need to be punished. Large deviations may bring more serious consequences. The mean absolute deviation treats all deviations equally and will not be significantly affected by outliers. It provides a uniform assessment of the overall deviation.

[0074] The sign of the deviation change trend is extracted. If the sign is positive, it indicates that the positioning deviation is on an upward trend. The positioning accuracy is evaluated based on the root mean square deviation, which can effectively reflect the fluctuation and stability of the positioning system in terms of accuracy. If the sign is not positive, it indicates that the positioning deviation is flat or on a downward trend. The positioning accuracy is evaluated based on the mean absolute deviation. This is because the mean absolute deviation provides a uniform assessment of the overall deviation, which helps to understand the average accuracy of the system without being affected by a single extreme deviation.

[0075] As a more specific implementation of the above scheme, the positioning accuracy evaluation can be carried out by dividing the mean absolute deviation or the root mean square deviation with the average positioning deviation data to eliminate the dimension, and then using three quarters as the base and the deviation value after eliminating the dimension as the exponent to construct an exponential function as a percentage to obtain the positioning accuracy.

[0076] When evaluating the positioning quality based on the positioning change curves of the absolute magnetic encoder and the incremental magnetic encoder, the present invention conducts a comprehensive evaluation from two dimensions: timely positioning response and precise positioning. This not only improves the evaluation reliability, but also provides a targeted direction for subsequent positioning adjustments.

[0077] Positioning adjustment is performed based on the positioning quality evaluation result. The specific adjustments are as follows: the positioning response timeliness and positioning accuracy within the positioning cycle are compared with the configured standard positioning evaluation value. For example, the standard positioning evaluation value is 90%. If both the positioning response timeliness and the positioning accuracy meet the standard positioning evaluation value, no positioning adjustment is required. If the positioning response timeliness does not meet the standard positioning evaluation value, indicating that the positioning time difference between the first and second magnetic encoders is large, the positioning interval duration of the first magnetic encoder and the second magnetic encoder is adjusted in the next positioning cycle. If the positioning accuracy does not meet the standard positioning evaluation value, the dominant positioning data corresponding to each time point is retrieved to determine the positioning adjustment object. Specifically, the dominant magnetic encoder at each time point is determined based on the dominant positioning data corresponding to each time point, and then the frequency of occurrence of the first and second magnetic encoders as the dominant magnetic encoders is counted, and the magnetic encoder with the least frequency of occurrence is selected as the positioning adjustment object, and the positioning adjustment object is adjusted in the next positioning cycle.

[0078] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A semiconductor product ranging and positioning method based on a magnetic encoder, characterized in that: The following steps are involved: Install a first magnetic encoder and a second magnetic encoder on the semiconductor manufacturing platform, wherein the first magnetic encoder is an absolute encoder and the second magnetic encoder is an incremental encoder; After installation, the encoder shaft and drive shaft are inspected for installation, including centering inspection and installation stability inspection; Perform distance measurement installation adjustments based on installation test results; After the ranging installation is adjusted, the first magnetic encoder is used to measure the distance and position the semiconductor product, and at the same time, the environment collection terminal set on the semiconductor manufacturing platform is used to collect environmental information, wherein the environmental information includes temperature, humidity, vibration displacement and electromagnetic interference noise frequency; Perform storage processing of the first magnetic encoder positioning data based on the collected environmental information; Based on the storage processing of the positioning data of the first magnetic encoder, the second magnetic encoder is used to measure the distance and position the semiconductor product, so as to obtain the positioning data of the second magnetic encoder; After each ranging and positioning, the positioning data of the second magnetic encoder and the first magnetic encoder are judged for positioning consistency, and the dominant positioning data is determined when it is judged that there is a positioning deviation; Setting a positioning cycle, and then retrieving the first magnetic encoder positioning data and the second magnetic encoder positioning data obtained by each ranging positioning within the positioning cycle to construct a positioning change curve; The positioning change curve of the first magnetic encoder is overlapped and compared with the positioning change curve of the second magnetic encoder, thereby evaluating the positioning quality; Make positioning adjustments based on the positioning quality evaluation results.

2. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 1, characterized in that: The centering detection process is as follows: Constructing central axes with the encoder shaft and the drive shaft as the center at the installation positions of the first magnetic encoder and the second magnetic encoder respectively, to obtain central axes corresponding to the encoder shaft and the drive shaft; The corresponding central axes of the encoder shaft and the drive shaft are overlapped and compared to identify whether the central axes of the two intersect. If they intersect, the angle between the central axes is obtained. If they do not intersect, the distance between the central axes is measured. The alignment conformity of the encoder is calculated using the angle or distance between the central axes.

3. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 2, characterized in that: The installation stability test process is as follows: One measuring surface of the measuring ruler is fixed on the encoder shaft at the installation positions of the first magnetic encoder and the second magnetic encoder, and the other measuring surface is fixed on the driving shaft; Read the measured value on the measuring ruler to get the axial clearance between the encoder shaft and the drive shaft, and compare it with the installation standard. The installation stability of the encoder is obtained by constructing an exponential function with the reciprocal of the natural constant as the base, the difference between the axial clearance and the installation standard divided by the absolute value of the installation standard as the exponent, and then taking the percentage.

4. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 3, characterized in that: The distance measurement installation and adjustment refer to the following process: Compare the alignment conformity and installation stability corresponding to the first magnetic encoder and the second magnetic encoder with the preset standard conformity and standard stability respectively. If the alignment conformity or installation stability corresponding to a certain magnetic encoder does not meet the standard conformity and standard stability, it is identified that ranging installation adjustment is required, and the installation adjustment object and installation adjustment direction are determined therefrom; Perform distance measurement installation adjustment according to the installation adjustment object and installation adjustment direction.

5. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 1, characterized in that: The storage and processing of the first magnetic encoder positioning data based on the collected environmental information is implemented as follows: Obtain the specification model of the first magnetic encoder, thereby obtaining the suitable environment information of the first magnetic encoder in the working state, and compare the collected environment information with the suitable environment information, and analyze the The environmental suitability ES corresponding to the first magnetic encoder is obtained, where T, D, X, and f respectively represent the temperature, humidity, vibration displacement, and electromagnetic interference noise frequency of the first magnetic encoder, and T0, D0, X0, and f0 respectively represent the suitable temperature, suitable humidity, suitable vibration displacement, and suitable electromagnetic interference noise frequency of the first magnetic encoder in a working state; The real-time positioning data of the first magnetic encoder and the environmental suitability are formed into a mapping data group and stored in a register, and a timestamp is added to each mapping data group; Compare the environmental suitability corresponding to the first magnetic encoder with the suitability threshold, and if the environmental suitability corresponding to the first magnetic encoder reaches the suitability threshold at a certain moment, mark the mapping data group corresponding to the moment as valid in the register; The storage space of the register is detected in real time to identify whether the storage is limited. If the storage is limited, the mapping data group is updated and stored.

6. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 5, characterized in that: The second magnetic encoder is used to measure the distance and position the semiconductor product based on the storage processing of the first magnetic encoder positioning data as follows: Acquire the positioning data and environmental suitability of the first magnetic encoder in real time, and compare the environmental suitability with the suitability threshold. If the environmental suitability of the first magnetic encoder reaches the suitability threshold at a certain moment, the positioning data of the first magnetic encoder at that moment is used as the reference position of the second magnetic encoder. Otherwise, extract the mapping data group closest to the current moment and with a valid data mark from the register based on the current moment, and then use the positioning data of the first magnetic encoder in the extracted mapping data group as the reference position. The semiconductor product is positioned and measured based on the reference position of the second magnetic encoder.

7. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 1, characterized in that: The positioning consistency evaluation is performed as follows: The positioning data of the second magnetic encoder is compared with the positioning data of the first magnetic encoder to calculate the positioning difference, and then compared with the preset allowable positioning difference. If the positioning difference is less than or equal to the allowable positioning difference, the evaluation positioning is consistent, otherwise the evaluation positioning has a deviation.

8. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 6, characterized in that: The dominant positioning data is determined as follows: Extract the environmental suitability of the positioning data provided by the first magnetic encoder from the register, and at the same time extract the power supply information from the power supply end of the second magnetic encoder, including the power supply frequency, power supply voltage and power supply current, and compare it with the power supply information at the previous moment to calculate the power supply fluctuation; The environmental suitability of the positioning data provided by the first magnetic encoder and the power supply fluctuation of the positioning data provided by the second magnetic encoder are compared with the suitability threshold and the fluctuation threshold respectively. The judgment result R of whether there is dominant positioning data is obtained. In the model, R=1 indicates that there is dominant positioning data, R=0 indicates that there is no dominant positioning data, P=P1 indicates that the dominant positioning data is the positioning data provided by the first magnetic encoder, P=P2 indicates that the dominant positioning data is the positioning data provided by the second magnetic encoder, PF indicates the power supply fluctuation degree of the second magnetic encoder providing the positioning data, ^ indicates the difference with,ES t PT t They represent the suitability threshold and the volatility threshold respectively; When it is determined that there is no dominant positioning data, the first magnetic encoder and the second magnetic encoder are re-measured and positioned.

9. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 1, characterized in that: The positioning quality evaluation is implemented as follows: Marking characteristic points on the positioning change curves of the first magnetic encoder and the second magnetic encoder respectively, and numbering the marked characteristic points in order from front to back on the positioning change curves; Based on the same numbering principle, the characteristic points marked on the positioning change curves of the first magnetic encoder and the second magnetic encoder are formed into an alignment group; Respectively obtain the time points of the characteristic points in each alignment group on the positioning change curves of the first magnetic encoder and the second magnetic encoder, thereby subtracting the time points to obtain the positioning time difference corresponding to each alignment group; The timeliness of positioning response is evaluated based on the positioning time difference corresponding to each alignment group; A number of time points are uniformly selected on the horizontal axis corresponding to the positioning change curve, and the positioning data of each time point on the positioning change curve of the first magnetic encoder and the second magnetic encoder are extracted to obtain the positioning deviation corresponding to each time point; Draw a deviation curve graph based on the positioning deviation corresponding to each time point, and extract the deviation change trend from the deviation curve graph; The average absolute deviation and root mean square deviation of the positioning deviation corresponding to each time point are calculated; The sign of the deviation change trend is extracted. If the sign is positive, the positioning accuracy is evaluated based on the root mean square deviation. If it is not positive, the positioning accuracy is evaluated based on the mean absolute deviation.

10. A semiconductor product distance measurement and positioning method based on a magnetic encoder as claimed in claim 9, characterized in that: The positioning adjustment process is as follows: The positioning response timeliness and positioning accuracy within the positioning cycle are compared with the configured standard positioning evaluation value. If the positioning response timeliness and positioning accuracy both meet the standard positioning evaluation value, no positioning adjustment is required. If the positioning response timeliness does not meet the standard positioning evaluation value, the positioning interval duration between the first magnetic encoder and the second magnetic encoder is adjusted in the next positioning cycle. If the positioning accuracy does not meet the standard positioning evaluation value, the dominant positioning data corresponding to each time point is retrieved, thereby determining the positioning adjustment object, and adjusting the positioning adjustment object in the next positioning cycle.

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