Five-point automatic leveling device and method for anti-bias load structure

Abstract

The application provides a five-point automatic leveling device of an anti-bias load structure, applied to a chuck mechanism, comprising: a driving unit assembled to the chuck mechanism, comprising a torque main motor and four auxiliary motors, the torque main motor being configured to support the chuck mechanism load, and the auxiliary motors being configured to perform bias leveling actions; a detection unit comprising five position sensors, the five position sensors being respectively arranged corresponding to the torque main motor and the four auxiliary motors, configured to collect position data of the driving unit in real time and output leveling feedback signals; and a control unit electrically connected to the driving unit and the detection unit, configured to drive the driving unit to act based on the leveling feedback signals, so that the chuck mechanism realizes automatic leveling under heavy load and bias load, and the auxiliary motors are symmetrically arranged at four corners of edges of the chuck mechanism, forming a five-point support layout with the torque main motor.

Description

Technical Field

[0001] This application relates to the field of semiconductor equipment technology, and more specifically, to a five-point automatic leveling device and method for an anti-offset structure. Background Technology

[0002] In the semiconductor testing industry, the chuck, as a core component carrying wafers, directly determines the accuracy of wafer testing results due to its flatness. With the increasing demands for testing memory chips, stringent requirements have been placed on the chuck's load-bearing capacity and resistance to off-center loads. Current chuck mechanisms have limited load-bearing capacity (typically ≤200kg) and insufficient resistance to off-center loads; when the off-center load exceeds 50kg, the chuck surface cannot be guaranteed to be level, failing to meet the testing requirements of memory chips. Furthermore, since chuck flatness is primarily achieved through manual adjustment during the assembly stage, it is not conducive to long-term operational adjustments. Therefore, developing an automatic chuck leveling technology that eliminates the need for manual adjustment, possesses high load-bearing capacity, and has stable resistance to off-center loads has become a critical issue urgently needing to be addressed in this field. Summary of the Invention

[0003] The purpose of this application is to address the technical problems in related technologies by providing a five-point automatic leveling device and method for anti-eccentric load structures. The specific solution is as follows: The first aspect of this application provides a five-point automatic leveling device for an anti-eccentric load structure, applied to a chuck mechanism, comprising: a drive unit, assembled in the chuck mechanism, including a main torque motor and four auxiliary motors, wherein the main torque motor is configured to support the load of the chuck mechanism, and the auxiliary motors are configured to perform eccentric load leveling actions; The detection unit includes five position sensors, which are respectively set to correspond to the torque main motor and the four auxiliary motors, and are configured to collect the position data of the drive unit in real time and output a leveling feedback signal. The control unit, electrically connected to the drive unit and the detection unit, is configured to drive the drive unit based on the leveling feedback signal, thereby enabling the chuck mechanism to automatically level itself under heavy and off-center loads. The main torque motor is mounted at the center of the chuck mechanism, and the four auxiliary motors are symmetrically arranged at the four corners of the edge of the chuck mechanism, forming a five-point support layout with the main torque motor.

[0004] In some embodiments, the output shaft of the torque main motor is coaxially connected to the chuck mechanism, configured to support the chuck mechanism to achieve a load of 500 kg on the Z-axis, wherein the Z-axis is perpendicular to the loading surface of the chuck.

[0005] In some embodiments, the five-point automatic leveling device of the anti-eccentric load structure further includes: a main motor encoder, which is rigidly connected to the end of the torque main motor and configured to collect the speed data of the torque main motor to avoid vibration of the torque main motor caused by heavy load in the Z-axis direction.

[0006] In some embodiments, the auxiliary motor has an auxiliary motor encoder integrated at the end of the auxiliary motor and configured to collect the speed data of the auxiliary motor to improve the operational stability of the off-center load leveling action.

[0007] In some embodiments, the five-point automatic leveling device of the anti-eccentric load structure further includes: a lead screw drive structure disposed between the torque main motor and the chuck mechanism, wherein the input end of the lead screw drive structure is rigidly connected coaxially to the output shaft of the torque main motor, and the output end of the lead screw drive structure is fixedly connected to the chuck mechanism, configured to stably transmit the power of the torque main motor.

[0008] In some embodiments, the position sensor is a grating ruler with an accuracy of ≥0.1μm, configured to provide accurate feedback for the horizontal calibration of the chuck mechanism.

[0009] A second aspect of this application provides a five-point automatic leveling method for an anti-eccentric load structure, applied to the five-point automatic leveling device for the anti-eccentric load structure provided in the first aspect of this application, comprising the following steps: S1: The control unit controls the power-on self-test of the drive unit, detection unit, main motor encoder and auxiliary motor encoder; S2: The main and auxiliary motors drive the chuck back to its mechanical origin, and the position sensors record the initial coordinates of each point as the leveling reference; the control unit commands the five motors to run synchronously through a precision motion control algorithm, and uses a precision control method of ≤±4 micrometers to eliminate inter-axis interference and ensure synchronous stability; S3: Place the workpiece to be tested on the loading surface of the chuck. The control unit adjusts the output of the drive unit according to the feedback data from the main motor encoder and position sensor to ensure the flatness of the chuck. S4: When the position sensor detects that the chuck's horizontal error exceeds 5μm, the control unit, based on the feedback data from the auxiliary motor encoder and the position sensor, instructs the corresponding auxiliary motor to operate independently until the error returns to within 5μm.

[0010] In some embodiments, in step S2, the following error and positioning error of the five motors operating synchronously are both ≤ ±4μm, further ensuring the stability of no-load synchronization.

[0011] In some embodiments, in step S3, under a load of 500 kg, the flatness error is ≤2 μm when the chuck running speed is 1 mm / s and ≤10 μm when the chuck running speed is 5 mm / s.

[0012] In some embodiments, in step S4, the control unit analyzes the deviation data fed back by the five position sensors to determine the off-center load direction and the magnitude of the deviation, and drives only the auxiliary motor in the corresponding area to perform the action, so as to avoid secondary deviation caused by the linkage of multiple motors.

[0013] Compared with related technologies, the above-described solutions of this application have at least the following beneficial effects: The five-point automatic leveling device and method for anti-eccentric load structure provided in this application significantly improves the load-bearing capacity of the chuck mechanism, enabling it to meet the heavy load requirement of 500kg. The anti-eccentric load capacity is significantly improved. The five-point detection and auxiliary motor precise correction design control the eccentric load error within 5 micrometers, solving the problem of insufficient anti-eccentric load capacity of traditional structures. The automated adjustment reduces the cost of manual operation and maintenance, and ensures operational stability while meeting the chuck accuracy requirements for chip testing.

[0014] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 This is a schematic diagram of the structure of a five-point automatic leveling device according to an exemplary embodiment.

[0016] Figure 2 This is a cross-sectional view of a five-point automatic leveling device according to an exemplary embodiment.

[0017] Figure 3 This is a schematic diagram of an assembly structure of a support base according to an exemplary embodiment.

[0018] Figure 4 This is a schematic diagram of the structure of a five-point automatic leveling device according to an exemplary embodiment.

[0019] Figure 5 This is a bottom view of a five-point automatic leveling device according to an exemplary embodiment.

[0020] Figure 6 This is a distribution diagram of the orientation test points of the loading surface of a chuck body, according to an exemplary embodiment.

[0021] Figure 7 This is a verification data statistics table illustrated according to an exemplary embodiment.

[0022] Figure label: Chuck mechanism 1000, chuck body 1100, loading surface 1110, bearing base 1200, first assembly position 1201, second assembly position 1202, lifting guide assembly 1300; Torque main motor 2100, main motor encoder 2110, auxiliary motor 2200, lead screw transmission structure 2300, linear drive mechanism 2400, power transmission component 2500; Position sensor 3000. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. “Multiple” generally includes at least two, and other quantifiers are similar.

[0025] It should be understood that although the terms "first," "second," "third," etc., may be used in the embodiments of this application, these descriptions should not be limited to these terms. These terms are only used to distinguish the described objects. For example, "first" may also be referred to as "second," and similarly, "second" may also be referred to as "first," without departing from the scope of the embodiments of this application. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] It should be understood that the term "and / or" as used herein is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. The singular forms "a," "the," and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It is further understood that the terms “center,” “longitudinal,” “lateral,” “front,” “rear,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0028] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0030] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0031] In the semiconductor testing industry, the chuck, as a core component that carries the wafer, directly determines the accuracy of wafer testing results due to its flatness. With the increasing demands for testing memory chips, chucks need to withstand core loads of around 500 kg while coping with off-center loads of up to 100 kg, requiring the horizontal error of the chuck surface to be controlled within 10 micrometers. This places stringent requirements on the chuck's load-bearing capacity and off-center load resistance.

[0032] In related technologies, chuck flatness is mainly achieved through manual adjustment during the assembly stage, which has two major drawbacks: first, the preset flatness is easily damaged during equipment transportation and on-site installation, requiring secondary adjustment; second, after long-term operation, factors such as changes in metal ductility and loosening of screws can cause flatness drift, resulting in high maintenance costs. Meanwhile, most equipment on the market uses a single-motor drive structure. While this structure is simple to control, its load-bearing capacity is usually no more than 200 kg, and its resistance to off-center loads is insufficient. When the off-center load exceeds 50 kg, the chuck surface cannot be guaranteed to be level, making it difficult to meet the testing requirements of memory chips. Some alternative solutions attempt to improve load-bearing capacity by replacing the splines with high-strength ones, but this is limited by domestic processing precision and supply constraints on imported splines, preventing industrial application. Therefore, there is an urgent need for an automatic chuck leveling technology that does not rely on manual adjustment, has a strong load-bearing capacity, and stable off-center load resistance.

[0033] To address the aforementioned technical problems, this application provides a five-point automatic leveling device and method for an anti-eccentric load structure, applied to a chuck mechanism. The device includes: a drive unit, assembled in the chuck mechanism, comprising a main torque motor and four auxiliary motors. The main torque motor is configured to support the load of the chuck mechanism, and the auxiliary motors are configured to perform eccentric load leveling actions; a detection unit, comprising five position sensors, each corresponding to the main torque motor and the four auxiliary motors, configured to collect real-time position data of the drive unit and output a leveling feedback signal; and a control unit, electrically connected to the drive unit and the detection unit, configured to control and drive the drive unit based on the leveling feedback signal, enabling the chuck mechanism to automatically level itself under heavy and eccentric load conditions. The main torque motor is mounted at the center of the chuck mechanism, and the four auxiliary motors are symmetrically arranged at the four corners of the chuck mechanism's edges, forming a five-point support layout with the main torque motor.

[0034] The five-point automatic leveling device and method for anti-eccentric load structure provided in this application significantly improves the load-bearing capacity of the chuck mechanism, enabling it to meet the heavy load requirement of 500kg. The anti-eccentric load capacity is significantly improved. The five-point detection and auxiliary motor precise correction design control the eccentric load error within 5 micrometers, solving the problem of insufficient anti-eccentric load capacity of traditional structures. The automated adjustment reduces the cost of manual operation and maintenance, and ensures operational stability while meeting the chuck accuracy requirements for chip testing.

[0035] The optional embodiments of this application are described in detail below with reference to the accompanying drawings.

[0036] This application provides a five-point automatic leveling device and method for an anti-eccentric load structure, applied to a chuck mechanism 1000, including a drive unit, a detection unit, and a control unit. The drive unit employs one central torque main motor 2100 and four auxiliary motors 2200. The detection unit includes five high-precision position sensors 3000, corresponding one-to-one with the torque main motor 2100 and auxiliary motors 2200, to collect motor position information. The control unit controls the precise movement of the five motors of the drive unit based on the real-time feedback position information, collaboratively achieving stable bearing capacity of 500kg heavy load and automatic eccentric load correction within 100kg.

[0037] In some embodiments, such as Figure 1 , Figure 2 As shown, the chuck mechanism 1000 is a support mechanism, including: a chuck body 1100, a support base 1200, and a lifting guide assembly 1300. The chuck body 1100 is the direct support component for wafer or chip testing. The support base 1200 is located at the bottom of the chuck body 1100 and is used to fix and assemble the drive unit, detection unit, and control unit. The lifting guide assembly 1300 is used to cooperate with the drive unit to realize the vertical lifting and horizontal posture maintenance of the chuck body 1100. The whole structure is a high-precision rigid structure, which is suitable for the stringent requirements of flatness and stability in memory chip testing, and provides a basic guarantee for the heavy load bearing and micron-level leveling of the leveling device.

[0038] In some embodiments, the chuck body 1100 can be a circular structure, and the loading surface 1110 of the chuck body 1100 is a high-precision polished plane. The precision of the loading surface 1110 directly determines the planar contact precision during chip testing. The direction perpendicular to the loading surface 1110 is the Z-axis direction.

[0039] In some embodiments, the support base 1200 is located below the chuck body 1100 and is an overall hollow rigid support structure. The bottom of the support base 1200 has multiple assembly positions for assembling the drive unit. A schematic diagram of the assembly positions of the support base 1200 is shown below. Figure 2 , Figure 3As shown, a first assembly position 1201 is provided at the center of the bearing base 1200, suitable for assembling the torque main motor 2100. Second assembly positions 1202 are evenly arranged around the first assembly position 1201, suitable for assembling the auxiliary motor 2200. The first assembly position 1201 is coaxial with the geometric center of the chuck body 1100, and the four second assembly positions 1202 at the edge are evenly distributed in a rectangle to ensure the symmetry of the drive unit layout and avoid initial flatness deviation caused by assembly eccentricity.

[0040] In some embodiments, such as Figure 4 As shown, the lifting guide assembly 1300 can be a linear guide rail assembly, with four sets arranged between the bearing base 1200 and the chuck body 1100. The four sets of linear guide rail assemblies are correspondingly configured with the auxiliary motor 2200 to restrict the horizontal displacement of the chuck body 1100, ensuring that the chuck body 1100 retains only its degree of freedom in the Z-axis direction. This ensures that the chuck body 1100 does not experience lateral displacement when the auxiliary motor 2200 performs leveling operations, improving the accuracy and efficiency of the leveling action.

[0041] In some embodiments, the torque main motor 2100 is the main power component of the drive unit. A high-precision torque motor with high torque and high rigidity can be selected. The torque main motor 2100 is mounted at the first mounting position 1201 at the center of the bearing base 1200 and is configured to provide the overall lifting power for the chuck mechanism 1000 so that the chuck loading surface 1110 can bear a load of 500kg.

[0042] In some embodiments, a lead screw transmission structure 2300 is provided between the torque main motor 2100 and the chuck body 1100. The lead screw transmission structure 2300 is rigidly connected to the output shaft of the torque main motor 2100 on the same axis, and is used to stably transmit the power provided by the torque main motor 2100. With the feedback data of the position sensor 3000, the chuck mechanism 1000 can be smoothly lifted and lowered under heavy load conditions.

[0043] The rigidity of the lead screw drive structure 2300 is adapted to the load-bearing capacity of the torque main motor 2100, avoiding power transmission distortion under heavy load pressure and ensuring the flatness stability during the lifting and lowering process of the chuck.

[0044] In some embodiments, the main motor encoder 2110 is an independently configured speed detection component, which is rigidly and seamlessly connected to the end of the torque main motor 2100. That is, there are no intermediate transmission components; it directly links with the shaft of the torque main motor 2100. It is configured to acquire the operating speed data of the torque main motor 2100 in real time and accurately, and transmit the data to the control unit, providing feedback for motor speed regulation under heavy load conditions.

[0045] The rigid connection between the main motor encoder 2110 and the torque main motor 2100 eliminates the speed feedback error caused by connection gaps in traditional transmission connections, ensuring that the speed data collected by the encoder is completely synchronized with the actual operating state of the motor. When the torque main motor 2100 carries a 500kg load, load changes can easily cause motor speed fluctuations and machine vibration. The control unit can quickly adjust the output power and torque of the torque main motor 2100 based on the real-time data fed back by the main motor encoder 2110, promptly offsetting the speed deviation caused by load fluctuations, effectively suppressing motor vibration, and thus preventing vibration from being transmitted to the chuck mechanism 1000 and causing flatness drift.

[0046] In some embodiments, the auxiliary motors 2200 serve as the power source for off-center load leveling. They can be small-volume, high-response, and high-precision servo leveling motors. The four auxiliary motors 2200 are arranged in a rectangular symmetrical configuration, evenly assembled at the four second mounting positions 1202 of the bearing base 1200, corresponding to the four edge detection points of the chuck body 1100. The auxiliary motors 2200 and the main torque motor 2100 form a centrally radial layout. The four auxiliary motors 2200 can independently receive commands from the control unit, achieving single-motor, dual-motor, or multi-motor coordinated leveling depending on the off-center load direction. This provides precise power output for chuck orientation correction, improving the accuracy and efficiency of off-center load correction.

[0047] In some embodiments, the auxiliary motor 2200 has an auxiliary motor encoder. The auxiliary motor encoder is an integrated detection component integrated into the auxiliary motor 2200 itself, directly integrated at the end of each auxiliary motor 2200, and coaxially linked with the shaft of the auxiliary motor 2200. It does not require additional separate installation and debugging, and is configured to collect the independent operating speed data of each auxiliary motor 2200 in real time and transmit the data to the control unit, providing dynamic feedback for the accurate and stable execution of the off-center load leveling action.

[0048] The auxiliary motor encoder can capture minute changes in the rotational speed of the auxiliary motor 2200 during micron-level leveling operations. When the chuck experiences off-center load error, the control unit commands the corresponding auxiliary motor 2200 to perform a leveling operation independently. In other words, based on the real-time data from the auxiliary motor encoder, the operating speed and lifting stroke of the auxiliary motor 2200 can be dynamically adjusted to avoid leveling overshoot caused by the auxiliary motor 2200 moving too fast or leveling lag caused by moving too slowly. This ensures that the leveling operation of each auxiliary motor 2200 is precise and controllable, guarantees the synchronization of the actions when multiple auxiliary motors 2200 are leveling together, improves the accuracy and efficiency of off-center load leveling, and allows the chuck's horizontal error to quickly return to within the 5μm threshold.

[0049] The integrated structure of the auxiliary motor encoder simplifies the overall assembly process of the five-point automatic leveling device. This structural design enables the auxiliary motor 2200 to meet the characteristics of small size and high response, and can better adapt to the refined and automated requirements of off-center load leveling.

[0050] In some embodiments, the detection unit includes five position sensors 3000, which are respectively configured to correspond one-to-one with the main torque motor 2100 and the four auxiliary motors 2200.

[0051] Specifically, four grating rulers are directly mounted on each set of lifting guide components 1300. The ruler body is rigidly connected to the fixed end of the lifting guide component 1300, the detection slider is fixedly connected to the moving end of the lifting guide component 1300, and the moving end of the lifting guide component 1300 is connected to the chuck body 1100. The grating rulers can collect the Z-axis displacement data of the chuck body 1100 caused by the lifting guide component 1300 in real time, accurately feedback the attitude deviation of the chuck body 1100, and form a closed-loop control with the lead screw transmission structure 2300 and the torque main motor 2100, providing accurate detection data support for the micron-level leveling of the chuck mechanism 1000.

[0052] In some embodiments, the position sensor 3000 is selected from a grating ruler with an accuracy of ≥0.1μm. The grating ruler has micron-level detection accuracy, high response speed and stable detection performance. It can accurately capture the small positional offset of the chuck body 1100 caused by heavy load and off-center load. It can better adapt to the stringent requirements of chuck flatness for memory chip testing. Compared with traditional low-precision position detection components, it completely solves the technical problem of insufficient leveling accuracy caused by large detection errors.

[0053] In some embodiments, such as Figure 5 As shown, the five-point automatic leveling device of the anti-eccentric load structure also includes: a power transmission component 2500. Four power transmission components 2500 are provided. The power transmission components 2500 are used to connect one of the auxiliary motors 2200 to the lifting guide component 1300, and transmit the rotational motion of the auxiliary motor 2200 to the lifting guide component 1300 through the linear drive mechanism 2400.

[0054] The lifting guide assembly 1300 corresponds one-to-one with the linear drive mechanism 2400 and is coaxially arranged. It is configured to limit the horizontal displacement and rotational offset of the linear drive mechanism 2400 to ensure that the linear motion of the linear drive mechanism 2400 is precise and controllable. The linear drive mechanism 2400 may be a rolling screw transmission structure 2300.

[0055] In some embodiments, the control unit is electrically connected to the drive unit and the detection unit, and is configured to drive the drive unit to operate based on the leveling feedback signal, so that the chuck mechanism 1000 can automatically level the chuck under heavy load and off-center load.

[0056] Specifically, the control unit is configured to receive micron-level position data of the chuck center and edge points, and convert the received position information into a leveling feedback signal.

[0057] In some embodiments, the control unit has a preset error threshold parameter to control the five-axis synchronization error of the main torque motor 2100 and four auxiliary motors 2200 to be ≤±4μm; when the chuck is subjected to a load of 500kg, the flatness error of the chuck is ≤2μm when the chuck runs at a speed of 1mm / s, and the flatness error of the chuck is ≤10μm when the chuck runs at a speed of 5mm / s; the off-center load error ≥5μm is the leveling program trigger threshold, the correction target is the off-center load error ≤5μm, and the control unit determines whether to start the leveling action and when to stop the leveling action based on the quantitative standard of the off-center load error.

[0058] In some embodiments, based on the application of a five-point automatic leveling device for an anti-eccentric load structure, this application also provides a five-point automatic leveling method for an anti-eccentric load structure. For example... Figure 6 As shown, it includes the following steps: S1: During system initialization, the control unit controls and drives all motors, detection units, main motor encoder 2110, and auxiliary motor encoder of the drive unit to perform power-on self-tests. After confirming that all components are functioning normally, the main motor 2100 and auxiliary motor 2200 drive the chuck back to the mechanical origin. At the same time, the five position sensors 3000 collect and record the initial coordinates of the chuck center and four edge points as the leveling reference. The mechanical origin is a fixed reference position precisely calibrated by the chuck mechanism 1000 before leaving the factory. It is the zero-position reference point for the chuck's horizontal attitude and Z-axis lifting, and also the starting reference position for all leveling actions of this device. This provides a unified reference standard for subsequent leveling steps, avoiding the influence of initial deviations on leveling accuracy.

[0059] S2: Establish a leveling reference; with the chuck unloaded, perform five-axis synchronous operation calibration on the main torque motor 2100 and the four auxiliary motors 2200 to ensure that the movement of the five motors is highly consistent and to eliminate inter-axis interference.

[0060] Specifically, the torque main motor 2100 and four auxiliary motors 2200 are started synchronously by the control unit. Combined with the real-time feedback data from the position sensor 3000 and the encoders of each motor, the motor operating parameters are dynamically fine-tuned to control the five-axis synchronization error of the torque main motor 2100 and the four auxiliary motors 2200 to ≤±4μm. This eliminates inter-axis interference, avoids flatness deviation caused by motor starting deviation during operation, and ensures the stability of chuck operation under subsequent heavy load and off-center load conditions.

[0061] S3: Smooth operation under heavy load; When the workpiece to be tested is placed on the loading surface 1110 of the chuck, the main torque motor 2100 bears the core load, and the flatness of the chuck changes due to the load. The control unit adjusts the motor output according to the speed data collected by the main motor encoder 2110 to counteract the vibration caused by the load change. At the same time, the position data collected by the position sensor 3000 is used as feedback to control the auxiliary motor 2200 to move with the main torque motor 2100 to calibrate the flatness of the chuck, ensuring that the flatness error of the chuck is ≤2μm when the chuck running speed is 1mm / s and ≤10μm when the chuck running speed is 5mm / s.

[0062] S4: Automatic Off-center Load Correction: When the chuck is subjected to an off-center load of ≤100kg, the position sensor 3000 detects that the horizontal error of the chuck exceeds the 5μm threshold and transmits the deviation signal to the control unit. The control unit determines the off-center load direction and deviation data. Based on the speed data fed back by the auxiliary motor encoder, it outputs an independent drive command to the corresponding auxiliary motor 2200, controlling the auxiliary motor 2200 at the corresponding position to move independently by lifting on the lower side and lowering on the raised side until the flatness error of the chuck is less than 5μm, then stops the leveling action and maintains the current posture.

[0063] In some embodiments, such as Figure 6 As shown, with the geometric center of the chuck as the origin, circumferential angles of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° are selected and marked as 1-8 respectively. These eight radial azimuth test points are used to verify that the five-point automatic leveling device and method for anti-eccentric load structure provided in this application have full circumferential anti-eccentric load leveling capability and precision control effect.

[0064] First, after completing steps S1 and S2 of the five-point automatic leveling method for the anti-eccentric load structure, the load on the chuck loading surface 1110 is removed, based on... Figure 6 The eight radial orientation test points selected by the caliber adopt a single-direction independent force application method. A 1.05KN eccentric load force is applied to each of the eight radial orientation test points of the chuck in sequence. Each time, only one test point is subjected to a single-direction force to simulate the actual eccentric load condition and avoid external disturbances from affecting the accuracy of the test data.

[0065] After the unidirectional off-center load is applied and the chuck attitude is stabilized, the initial level error of the chuck is detected by five position sensors 3000 with an accuracy ≥0.1μm. The control unit automatically triggers off-center load correction. By analyzing the deviation data fed back by the position sensors 3000, the off-center load direction and deviation amplitude are accurately determined. When the control unit detects that the chuck flatness error is within a preset threshold, it controls the auxiliary motor 2200 to stop the leveling action.

[0066] During the verification process, three core data points were recorded: the initial error value of the directional off-center load test at the test point, the correction response time, and the stable error value after correction. For example... Figure 7 As shown, for example, the test data for the 0° azimuth is: initial error 4.8μm, correction response time 0.32s, and stable error after correction 1.2μm; after the test in a single direction is completed, the load force in that direction is removed, and the torque main motor 2100 and auxiliary motor 2200 are controlled to drive the chuck back to the mechanical origin to restore the initial standard posture. Then, the test data statistics for the remaining seven radial azimuths are completed in sequence according to the above steps.

[0067] The final verification results show that in the five-point automatic leveling device for the anti-eccentric load structure provided in this application, after the chuck is subjected to an eccentric load of 1.05KN in eight radial directions, the five-point automatic leveling method of the anti-eccentric load structure automatically corrects the eccentricity. The eccentricity correction response in each direction is timely, no secondary deviation is generated, and the horizontal error of the chuck is stably controlled within 5μm after correction, which meets the requirements for use under eccentric load conditions in the testing of memory chips.

[0068] The specific structure, working principle, and beneficial effects of the five-point automatic leveling device and method for anti-eccentric load structure provided in this application embodiment can be referred to in any of the above embodiments, and will not be repeated here.

[0069] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0070] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A five-point automatic leveling device with an anti-eccentric load structure, applied to a chuck mechanism, characterized in that, include: The drive unit, assembled in the chuck mechanism, includes a main torque motor and four auxiliary motors. The main torque motor is configured to support the load of the chuck mechanism, and the auxiliary motors are configured to perform off-center load leveling. The detection unit includes five position sensors, which are respectively set to correspond to the torque main motor and the four auxiliary motors, and are configured to collect the position data of the drive unit in real time and output a leveling feedback signal. The control unit, electrically connected to the drive unit and the detection unit, is configured to drive the drive unit based on the leveling feedback signal, thereby enabling the chuck mechanism to automatically level itself under heavy and off-center loads. The main motor encoder is rigidly and seamlessly connected to the end of the torque main motor. It is used to collect the operating speed data of the torque main motor and transmit the data to the control unit. The main torque motor is mounted at the center of the chuck mechanism, and the four auxiliary motors are symmetrically arranged at the four corners of the edge of the chuck mechanism, forming a five-point support layout with the main torque motor. The control unit is electrically connected to the drive unit and the detection unit respectively, and is configured to instruct the corresponding auxiliary motor to perform a leveling action independently based on the leveling feedback signal until the horizontal error of the chuck is less than 5μm.

2. The five-point automatic leveling device for the anti-eccentric load structure according to claim 1, characterized in that, The output shaft of the torque main motor is coaxially connected to the chuck mechanism and configured to support the chuck mechanism to achieve a load of 500kg on the Z-axis, wherein the Z-axis is perpendicular to the loading surface of the chuck mechanism.

3. The five-point automatic leveling device for the anti-eccentric load structure according to claim 1, characterized in that, The auxiliary motor has an auxiliary motor encoder, which is integrated at the end of the auxiliary motor and configured to collect the speed data of the auxiliary motor to improve the operational stability of the off-center load leveling action.

4. The five-point automatic leveling device for the anti-eccentric load structure according to claim 1, characterized in that, Also includes: A lead screw drive structure is disposed between the torque main motor and the chuck mechanism. The input end of the lead screw drive structure is rigidly connected to the output shaft of the torque main motor, and the output end of the lead screw drive structure is fixedly connected to the chuck mechanism, configured to stably transmit the power of the torque main motor.

5. The five-point automatic leveling device for the anti-eccentric load structure according to claim 1, characterized in that, The position sensor is a grating ruler with an accuracy of ≥0.1μm, configured to provide accurate feedback for the horizontal calibration of the chuck mechanism.

6. A five-point automatic leveling method for an anti-eccentric load structure, characterized in that, The five-point automatic leveling device applied to the anti-eccentric load structure according to any one of claims 1-5 includes the following steps: S1: The control unit controls the power-on self-test of the drive unit, detection unit, main motor encoder and auxiliary motor encoder; S2: The main and auxiliary motors drive the chuck back to its mechanical origin, and the position sensors record the initial coordinates of each point as the leveling reference; the control unit commands the five motors to run synchronously through a precision motion control algorithm, and uses a precision control method of ≤±4 micrometers to eliminate inter-axis interference and ensure synchronous stability; S3: Place the workpiece to be tested on the loading surface of the chuck. The control unit adjusts the output of the drive unit according to the feedback data from the main motor encoder and position sensor to ensure the flatness of the chuck. S4: When the position sensor detects a chuck horizontal error exceeding 5μm, the control unit, based on feedback data from the auxiliary motor encoder and position sensor, instructs the corresponding auxiliary motor to operate independently until the error returns to within 5μm. In step S4, the control unit analyzes the deviation data fed back by the five position sensors to determine the direction and magnitude of the off-center load, and only drives the auxiliary motor in the corresponding area to perform the action, so as to avoid secondary deviation caused by the linkage of multiple motors.

7. The five-point automatic leveling method for an anti-eccentric load structure according to claim 6, characterized in that, In step S2, the following error and positioning error of the five motors running synchronously are both ≤ ±4μm, further ensuring the stability of no-load synchronization.

8. The five-point automatic leveling method for an anti-eccentric load structure according to claim 6, characterized in that, In step S3, under a load of 500kg, the flatness error is ≤2μm when the chuck running speed is 1mm / s and ≤10μm when the chuck running speed is 5mm / s.

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