Method for optimizing structure of target motion platform ceramic part based on dynamics

Abstract

The application provides a structure optimization method for a target motion platform ceramic piece based on dynamics, and belongs to the technical field of dynamic analysis. In view of the problems of low precision of modal characteristic test and high research and development cost of a motion platform ceramic piece, the application provides a structure optimization method for a target motion platform ceramic piece based on dynamics, which comprises the following steps: S1, a simulation digital model of the motion platform ceramic piece is established; S2, the simulation digital model of the motion platform ceramic piece is corrected based on comparison of modal data of experimental modal and simulation calculation modal; and S3, the motion platform ceramic piece is optimized in structure based on key parameters affecting the modal of the motion platform ceramic piece, modal data of the simulation digital model of the motion platform ceramic piece after correction, and modal data of the corresponding experimental modal. The application compares the experimental modal and the calculation modal of the motion platform ceramic piece, improves the reliability of modal characteristic test, and reduces the research and development cost through closed-loop iteration of “virtual prediction-physical verification-model correction”.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of kinetic analysis, in particular to a method for optimizing the structure of a motion stage ceramic piece based on kinetics. BACKGROUND

[0002] As a core component of a lithography machine that bears high-precision guiding and supporting, the modal characteristics (natural frequency, mode shape, damping ratio, etc.) of a motion stage ceramic piece directly affect the dynamic stability, positioning accuracy, and anti-interference ability of the motion stage. In the research and development process of the motion stage ceramic piece, its dynamic characteristics are generally obtained through experimental modal testing, and then structural optimization is performed.

[0003] Disadvantages:

[0004] 1. The boundary conditions (such as fixing methods) of experimental modal testing need to simulate the actual working conditions as much as possible, but in actual work, there may be complex constraints (such as elastic support of air bearing, connection stiffness of multiple components);

[0005] 2. The ceramic piece may be subjected to multi-field coupling such as heat, force, electricity, and magnetism in actual work, and modal testing is usually performed under a single working condition (such as normal temperature and no load), which cannot capture the dynamic influence of multi-field coupling on modal characteristics.

[0006] 3. The motion stage ceramic piece has characteristics such as lightweight, high stiffness, and low thermal deformation, and the manufacturing cost is high, resulting in high cost of experimental modal testing, and thus increasing the research and development cost. SUMMARY

[0007] The present application aims to solve the problems of low precision of motion stage ceramic piece modal characteristic testing and high research and development cost in the prior art. Therefore, the present application provides a method for optimizing the structure of a motion stage ceramic piece based on kinetics, which compares the experimental modal of the motion stage ceramic piece with the calculated modal, improves the reliability of modal characteristic testing, and reduces the research and development cost through closed-loop iteration of "virtual prediction-physical verification-model correction".

[0008] The present application provides a method for optimizing the structure of a motion stage ceramic piece based on kinetics, comprising:

[0009] S1, a simulation digital model of the motion stage ceramic piece is established;

[0010] S2, the simulation digital model of the motion stage ceramic piece is corrected based on the comparison of modal data of experimental modal and simulation calculated modal;

[0011] S3, the structure of the motion stage ceramic piece is optimized based on the key parameters affecting the modal of the motion stage ceramic piece, the modal data of the corrected simulation digital model of the motion stage ceramic piece, and the modal data of the corresponding experimental modal.

[0012] In some embodiments, the S2 corrects the simulation digital model of the motion stage ceramic piece based on a modal data comparison between an experimental modal and a simulation calculation modal, including:

[0013] The S21 obtains simulation modal data of the motion stage ceramic piece based on the simulation digital model of the motion stage ceramic piece;

[0014] The S22 manufactures the motion stage ceramic piece based on the simulation digital model of the motion stage ceramic piece;

[0015] The S23 obtains experimental modal data of the motion stage ceramic piece under an experimental modal test;

[0016] The S24 obtains frequency errors of both the simulation modal data and the experimental modal data based on the simulation modal data and the experimental modal data;

[0017] The S25 corrects the simulation digital model of the motion stage ceramic piece if the frequency error > a preset threshold, and repeats the S21-S24 until the frequency error ≤ the preset threshold; and,

[0018] The S3 performs structural optimization on the motion stage ceramic piece based on key parameters affecting the modal of the motion stage ceramic piece, modal data of the simulation digital model of the motion stage ceramic piece after correction, and modal data of the corresponding experimental modal, including:

[0019] The S31 determines the key parameters affecting the modal of the motion stage ceramic piece based on sensitivity analysis;

[0020] The S32 performs structural optimization on the motion stage ceramic piece corresponding to the simulation digital model of the motion stage ceramic piece satisfying the frequency error ≤ the preset threshold based on the key parameters, the simulation modal data, and the experimental modal data, and repeats the S21-S23 until the simulation modal data and the experimental modal data both meet design requirements.

[0021] In some embodiments, the structural optimization on the simulation digital model of the motion stage ceramic piece includes topology optimization or size optimization on the simulation digital model of the motion stage ceramic piece; and the motion stage ceramic piece includes a body part, a groove part located in the middle of the body part, and an edge thinning part located at the edge of the body part, and the structural optimization sequence is the body part, the groove part, and the edge thinning part of the motion stage ceramic piece in order.

[0022] In some embodiments, the edge thinning part covers the edge angle of the motion stage ceramic piece, and the edge thinning part is located at a distance ≥ 1 / 5 of the length of the shortest side of the corresponding edge angle of the motion stage ceramic piece.

[0023] In some embodiments, the chamfer of the edge thinning portion and the chamfer of the groove portion are each provided, and the radius of the chamfer of the groove portion is ≤30% of the depth of the groove portion, and the radius of the chamfer of the edge thinning portion is ≤20% of the thickness of the edge thinning portion.

[0024] In some embodiments, the simulation modal data includes low-order bending modal data and low-order torsional modal data.

[0025] The experimental modal test of the motion table ceramic piece includes, under operational modal testing, taking the body portion, the groove portion, and the thinning portion of the motion table ceramic piece as excitation positions, respectively.

[0026] In some embodiments, the establishing of the simulation digital model of the motion table ceramic piece includes:

[0027] Based on finite element modeling, the simulation digital model of the motion table ceramic piece is established.

[0028] In some embodiments, the obtaining of the experimental modal data of the motion table ceramic piece under experimental modal testing includes:

[0029] The hammering method is adopted, and an acceleration sensor is used to collect vibration responses.

[0030] The experimental modal data is extracted based on frequency response function analysis.

[0031] Based on operational deformation analysis, the vibration mechanism is analyzed, and the actual vibration mode is obtained.

[0032] In some embodiments, the correction of the simulation digital model of the motion table ceramic piece includes:

[0033] The simulation digital model of the motion table ceramic piece is simplified under the assumption condition, which includes the neglecting of the pores of the motion table ceramic piece; and / or,

[0034] The material parameters or boundary conditions of the simulation digital model of the motion table ceramic piece are adjusted, the material parameters include the elastic modulus, and the boundary conditions include the contact stiffness.

[0035] In some embodiments, the preset threshold is 10%.

[0036] Beneficial effects:

[0037] The experimental modal of the motion table ceramic piece is compared with the calculated modal, through the closed-loop iteration of “virtual prediction-physical verification-model correction”, the test accuracy of the modal characteristics of the ceramic piece is improved, the modal characteristics of the ceramic piece are ensured to meet the dynamic stability requirements of the lithography machine, the number of physical prototype trial production is reduced, the research and development cost is greatly reduced, and the modal stability can be verified through the accelerated life test, so that the ceramic piece does not resonate and fail in the whole life cycle of the lithography machine.

[0038] Other features and corresponding advantages of the present application will be set forth in the description that follows, and in part will be apparent from the description or can be learned by practice of the application. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A flowchart of the present application;

[0040] Figure 2 A structural diagram of a motion platform ceramic piece of the present application.

[0041] 1, body part; 2, groove part; 3, edge thinning part. DETAILED DESCRIPTION

[0042] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0043] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0044] The edge thinning part 3 motion platform ceramic piece, as a core component for bearing high-precision guiding and supporting in a lithography machine, has characteristics of lightweight, high rigidity and low thermal deformation, and has high manufacturing cost.

[0045] At the same time, experimental modal testing is difficult to comprehensively and truly simulate complex constraints (such as elastic support of air bearing, multi-component connection stiffness) and multi-field coupling (such as thermal, force, electric, magnetic and other multi-field coupling) in actual working conditions, resulting in low precision of modal characteristics obtained by testing.

[0046] The superposition of the two results in extremely high research and development cost of the motion platform ceramic piece.

[0047] The embodiment of the present application provides a motion platform ceramic piece structure optimization method based on dynamics alignment, aligns experimental modal of the motion platform ceramic piece with calculated modal, and through closed-loop iteration of "virtual prediction-physical verification-model correction", improves the test precision of the ceramic piece modal characteristics, realizes ensuring that the ceramic piece modal characteristics meet the dynamic stability requirements of the lithography machine, reduces the number of physical prototype trial production, greatly reduces the research and development cost, and can verify the modal stability through accelerated life test, and ensures that the ceramic piece has no resonance failure in the whole life cycle of the lithography machine.

[0048] Please refer to Figure 1 ,Figure 1 Flowchart of the present application.

[0049] The method comprises:

[0050] S1. Establishing a simulation digital model of the motion platform ceramic piece.

[0051] In one embodiment, the simulation digital model of the motion platform ceramic piece is established based on finite element modeling, such as ANSYS.

[0052] The modeling contains geometric features, material properties (elastic modulus, density, Poisson's ratio), and boundary conditions (fixed constraints or elastic support).

[0053] S2. Based on the modal data comparison between the experimental modal and the simulation calculated modal, the simulation digital model of the motion platform ceramic piece is corrected.

[0054] Specifically, it comprises:

[0055] S21. Based on the simulation digital model of the motion platform ceramic piece, simulation modal data of the motion platform ceramic piece is obtained, i.e. the natural frequency, mode shape and damping ratio are calculated.

[0056] In one embodiment, the simulation modal data includes low-order bending modal data and low-order torsional modal data, thereby improving the comprehensiveness, accuracy and reliability of the simulation modal data.

[0057] S22. Based on the simulation digital model of the motion platform ceramic piece, the motion platform ceramic piece is manufactured.

[0058] S23. Experimental modal data of the motion platform ceramic piece under experimental modal testing is obtained.

[0059] In one embodiment, the hammering method is used, and an acceleration sensor is used to collect the vibration response.

[0060] Further, the experimental modal data is extracted based on frequency response function (FRF) analysis.

[0061] Further, the actual mode shape is obtained by analyzing the vibration mechanism based on operating deflection shapes (ODS).

[0062] In one embodiment, the experimental modal testing of the motion platform ceramic piece includes the body part 1, the groove part 2 and the thinned part of the motion platform ceramic piece as the excitation position under the working modal testing, thereby improving the comprehensiveness, accuracy and reliability of the experimental modal data.

[0063] In other alternative embodiments, a shaker, preferably a micro-piezoelectric shaker, is used to perform sinusoidal sweep or burst random excitation, and a scanning laser Doppler vibrometer is used to collect the vibration response.

[0064] S24, based on the simulation modal data and the experimental modal data, obtaining a frequency error of the two.

[0065] S25, if the frequency error > a preset threshold, correcting the simulation digital model of the motion platform ceramic piece, and repeating S21-S24 until the frequency error ≤ the preset threshold.

[0066] In one embodiment, the preset threshold is 10%, which can balance the cost and accuracy.

[0067] Preferably, the preset threshold is 5-6%, which further improves the accuracy and can improve the structural optimization efficiency.

[0068] In one embodiment, the correction of the simulation digital model of the motion platform ceramic piece includes simplifying the assumption conditions of the simulation digital model of the motion platform ceramic piece, such as ignoring the pores of the motion platform ceramic piece.

[0069] In one embodiment, the correction of the simulation digital model of the motion platform ceramic piece includes adjusting the material parameters or boundary conditions of the simulation digital model of the motion platform ceramic piece, such as the elastic modulus, contact stiffness, etc.

[0070] S3, based on the key parameters affecting the modal of the motion platform ceramic piece, the modal data of the corrected simulation digital model of the motion platform ceramic piece, and the modal data of the corresponding experimental modal, performing structural optimization on the motion platform ceramic piece.

[0071] Specifically, it includes:

[0072] S31, determining the key parameters affecting the modal of the motion platform ceramic piece based on sensitivity analysis.

[0073] This analysis can effectively focus on the core parameters of design optimization and reduce unnecessary calculation cost.

[0074] In one embodiment, the key parameters are the sizes and spacings of the motion platform ceramic piece, i.e., the sizes and spacings of the body part 1, the groove part 2, and the edge thinning part 3.

[0075] S32, based on the key parameters, the simulation modal data, and the experimental modal data, performing structural optimization on the motion platform ceramic piece corresponding to the simulation digital model of the motion platform ceramic piece that meets the frequency error ≤ the preset threshold, and repeating S21-S23 until the simulation modal data and the experimental modal data both meet the design requirements.

[0076] In one embodiment, the simulation digital model of the motion platform ceramic piece is structurally optimized, including topological optimization or size optimization of the simulation digital model of the motion platform ceramic piece.

[0077] See Figure 2 , Figure 2 The structural diagram of the motion platform ceramic piece of the present application.

[0078] The structural optimization direction of the motion platform ceramic piece is to set special-shaped thinning regions in the middle and the edge, that is, the motion platform ceramic piece usually includes a body part 1, a groove part 2 located in the middle of the body part 1, and an edge thinning part 3 located at the edge of the body part 1.

[0079] In one embodiment, the structural optimization sequence is the body part 1, the groove part 2, and the edge thinning part 3 of the motion platform ceramic piece in turn, that is, the body part 1 of the motion platform ceramic piece has the largest volume and the thickest thickness, and has the largest structural optimization space, the groove part 2 is located in the middle of the body part 1, and has less influence on the mechanical properties of the motion platform ceramic piece, and the edge thinning part 3 has greater influence on the mechanical properties of the motion platform ceramic piece, and the edge shape has high requirements on the manufacturing process, and has the smallest structural optimization space.

[0080] By sequentially performing structural optimization, the structural optimization efficiency can be improved, thereby reducing the research and development cost.

[0081] In one embodiment, the edge thinning part 3 covers the edge angle of the motion platform ceramic piece, and the distance between the edge thinning part 3 and the edge angle of the motion platform ceramic piece is ≥1 / 5 of the length of the shortest side where the corresponding edge angle is located, so as to consider light weight, stiffness and deformation on the basis of modal characteristic optimization.

[0082] In one embodiment, the edge thinning part 3 and the groove part 2 are both provided with chamfers, and the radius of the chamfer of the groove part 2 is ≤30% of the depth of the groove part 2, and the radius of the chamfer of the edge thinning part 3 is ≤20% of the edge thinning thickness.

[0083] The method can greatly reduce the number of physical prototype trial production, which can be reduced from usually 5 rounds to 2-3 rounds, thereby greatly reducing the research and development cost.

[0084] Moreover, through the closed-loop optimization of "simulation-test-correction", the synergistic effect of "1+1>2" is realized, specifically, the modal test provides "real benchmark" to verify the design and find problems, the simulation provides "prediction ability" to optimize the design and predict the performance, and the cooperation of the two can realize "rapid iteration and accurate design", which significantly improves the structural optimization design efficiency.

[0085] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for optimizing the structure of a target motion platform ceramic piece based on dynamics, characterized in that, The method comprises the following steps: S1: establishing a simulation digital model of a motion platform ceramic piece; S2: correcting the simulation digital model of the motion platform ceramic piece based on modal data comparison between experimental modal and simulation calculation modal; S3: performing structural optimization on the motion platform ceramic piece based on key parameters affecting the modal of the motion platform ceramic piece, modal data of the corrected simulation digital model of the motion platform ceramic piece, and modal data of the corresponding experimental modal; The motion platform ceramic piece comprises a body part, a groove part located in the middle of the body part, and an edge thinning part located at the edge of the body part. The structural optimization sequence is the body part, the groove part, and the edge thinning part of the motion platform ceramic piece in sequence, and meets the following conditions: the edge thinning part covers the edge angle of the motion platform ceramic piece, and the distance between the edge thinning part and the edge angle of the motion platform ceramic piece is greater than or equal to 1 / 5 of the length of the shortest side where the corresponding edge angle is located; both the edge thinning part and the groove part are provided with chamfers, and the radius of the chamfer of the groove part is less than or equal to 30% of the depth of the groove part, and the radius of the chamfer of the edge thinning part is less than or equal to 20% of the edge thinning thickness; The S2 corrects the simulation digital model of the motion platform ceramic piece based on modal data comparison between experimental modal and simulation calculation modal, which comprises the following steps: S21: obtaining simulation modal data of the motion platform ceramic piece based on the simulation digital model of the motion platform ceramic piece; S22: manufacturing the motion platform ceramic piece based on the simulation digital model of the motion platform ceramic piece; S23: obtaining experimental modal data of the motion platform ceramic piece under experimental modal test; S24: obtaining frequency error of the simulation modal data and the experimental modal data; S25: if the frequency error is greater than a preset threshold, correcting the simulation digital model of the motion platform ceramic piece, and repeating S21-S24 until the frequency error is less than or equal to the preset threshold; and The S3 performs structural optimization on the motion platform ceramic piece based on key parameters affecting the modal of the motion platform ceramic piece, modal data of the corrected simulation digital model of the motion platform ceramic piece, and modal data of the corresponding experimental modal, which comprises the following steps: S31: determining key parameters affecting the modal of the motion platform ceramic piece based on sensitivity analysis; S32: performing structural optimization on the motion platform ceramic piece corresponding to the simulation digital model of the motion platform ceramic piece which meets the condition that the frequency error is less than or equal to the preset threshold based on the key parameters, the simulation modal data, and the experimental modal data, and repeating S21-S23 until the simulation modal data and the experimental modal data both meet the design requirements; The correction of the simulation digital model of the motion platform ceramic piece comprises the following steps: simplifying the assumption conditions of the simulation digital model of the motion platform ceramic piece, which comprises neglecting the pores of the motion platform ceramic piece; and / or adjusting the material parameters or boundary conditions of the simulation digital model of the motion platform ceramic piece, the material parameters comprising elastic modulus, and the boundary conditions comprising contact stiffness; The preset threshold is 10%.

2. The method of claim 1, wherein the structure optimization of the motion platform ceramic piece based on the dynamics of the target is performed by: performing structure optimization on the simulation digital model of the motion platform ceramic piece, including topology optimization or size optimization on the simulation digital model of the motion platform ceramic piece.

3. The method of claim 2, wherein the simulation modal data includes low-order bending modal data and low-order torsional modal data; the experimental modal test of the motion platform ceramic piece includes, under the working modal test, the body part, the groove part, and the thinned part of the motion platform ceramic piece as the excitation positions respectively; the simulation digital model of the motion platform ceramic piece is established by: establishing the simulation digital model of the motion platform ceramic piece based on finite element modeling; the experimental modal data of the motion platform ceramic piece under the experimental modal test is obtained by: using the hammering method and using the acceleration sensor to collect the vibration response; extracting the experimental modal data based on the frequency response function analysis; and analyzing the vibration mechanism based on the working deformation analysis to obtain the actual vibration mode.

4. The method of claim 1, wherein the simulation digital model of the motion platform ceramic piece is established by: establishing the simulation digital model of the motion platform ceramic piece based on finite element modeling.

5. The method of claim 1, wherein the experimental modal data of the motion platform ceramic piece under the experimental modal test is obtained by: using the hammering method and using the acceleration sensor to collect the vibration response; extracting the experimental modal data based on the frequency response function analysis; and analyzing the vibration mechanism based on the working deformation analysis to obtain the actual vibration mode. ​ 4. The method of claim 1, wherein the method further comprises: ​ ​ 5. The method of claim 1, wherein: ​ ​ ​ ​

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