Resonance treatment method for environmental control air bath

Abstract

The embodiment of the invention provides a resonance processing method for environmental control air bath, which comprises the following steps: before an environmental control air bath system enters a processing and manufacturing stage, establishing a three-dimensional model of the environmental control air bath system, and carrying out discrete processing on the three-dimensional model; and carrying out modal analysis on the environment control air bath system after discrete processing to obtain the inherent frequency and the vibration mode of the environment control air bath system. The inherent frequency of the environmental control air bath system is compared with the excitation frequency of a known excitation source, and accordingly key geometric parameters or material parameters are adjusted, so that the inherent frequency effectively deviates from the excitation frequency range, and resonance is avoided from a design source. According to the method, the resonance risk of the environment control air bath system can be identified in the design stage without making the environment control air bath system with high cost into a real object, and the inherent frequency of the environment control air bath system is accurately controlled in a safe range through targeted design tuning, so that the later debugging cost is remarkably reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of environmental control air bath, and in particular to a resonance processing method for an environmental control air bath. BACKGROUND

[0002] A lithography machine is a crucial device in semiconductor manufacturing, and its core function is to "transfer" the designed circuit pattern to a silicon wafer. The exposure process of the lithography machine is carried out at the nanometer scale, and materials such as metals and glasses will expand and contract with temperature changes. Even a temperature change of 0.01°C is enough to cause slight deformation or displacement of key components such as the objective lens and the wafer stage, resulting in imaging distortion and overlay errors. The environmental control air bath of the lithography machine is a high-precision temperature control technology for the local microenvironment inside the lithography machine. It forms a stable and isolated "air bath" environment by blowing constant-temperature, uniform and clean air flow to the core working area, thereby suppressing the influence of temperature fluctuations on lithography precision.

[0003] Traditionally, the design and verification of the environmental control air bath device mainly rely on high-rigidity cavity structures, low-resistance and high-efficiency filters, and excellent static mechanical properties, and high-precision machining and assembly are used to ensure the physical indicators achieved. However, the existing design methodology has significant limitations: The environmental control air bath device does not work independently, but is closely coupled with the precision workpiece stage, mask stage, vacuum pump, refrigeration compressor and many other vibration sources inside the lithography machine. This high-frequency mechanical coupling effect across subsystems easily induces structural resonance, seriously threatening the overall stability of the lithography machine. However, the existing design usually pursues the structural stability and static mechanical properties of the air bath device itself in isolation, without fully considering its dynamic behavior under complex multi-physical field excitation.

[0004] Ignoring the dynamic characteristics not only brings instantaneous vibration problems, but also the long-term fatigue effects caused by it are even more deadly. Continuous resonance can cause problems such as structural fretting wear, connection point loosening, material fatigue cracking, and sensor measurement reference drift, significantly shortening the service life of key components, increasing maintenance frequency, reducing the overall availability of the equipment, and ultimately increasing costs.

[0005] Moreover, the lack of systematic dynamic analysis and optimization of the air bath device at the design stage leads to its susceptibility to structural resonance under actual working conditions. When problems occur, troubleshooting becomes extremely difficult because the air bath device has already been integrated into the lithography machine, and temporary remedies such as sticking damping materials, adding weights or adjusting system operating parameters are often used. These methods may temporarily alleviate the vibration phenomenon, but they are usually only a temporary solution and cannot fundamentally eliminate the vibration source. Moreover, they may sacrifice the key performance of the equipment, and the high cost of the air bath device itself makes constant remediation or debugging a significant cost increase. SUMMARY

[0006] This application aims to address the problem that existing lithography machine gas bath devices lack systematic dynamic characteristic analysis and structural optimization during the design phase, leading to a significant increase in subsequent processing and debugging costs. By conducting dynamic modeling and analysis of the environmentally controlled gas bath system, this application optimizes its structure to avoid resonance between the system and other excitation sources, thereby reducing debugging difficulty and overall cost.

[0007] This application provides a resonance treatment method for an environmentally controlled gas bath, including: S1. Establish a three-dimensional model of the environmental control air bath system and discretize the three-dimensional model; S2. Perform modal analysis on the discretized environmental control air bath system to obtain the natural frequencies and mode shapes of the environmental control air bath system. S3. Compare and analyze the natural frequency with the excitation frequency of the excitation source; S4. Determine whether the natural frequency avoids the excitation frequency. If it does not avoid it, adjust the environmental control air bath system and repeat steps S1 to S3 until the natural frequency avoids the excitation frequency. S5. Store the finalized model of the environmental control air bath system into the model library.

[0008] In some embodiments, the process of establishing a three-dimensional model of the environmental control air bath system and discretizing the three-dimensional model in step S1 is as follows: S11. Use CAD software to create a three-dimensional model of the environmental control air bath system; S12. Using the Ansys module, import the 3D model established in S11 and discretize the model into a finite number of interconnected simple elements, which are hexahedral elements. S13. After the discretization is completed and checked to be correct, set the material parameters of each component in the environmental control air bath system. S14. Define the boundary conditions of the environmental control air bath system, simplify the interaction between the environmental control air bath system and the foundation or rigid foundation, and treat the boundary conditions as fully constrained.

[0009] In some embodiments, in step S13, the material parameters are: the model material is aluminum alloy, elastic modulus: 70 GPa, Poisson's ratio: 0.33, density: 2700 kg / m³.

[0010] In some embodiments, in step S3, the excitation source is a wind turbine; the excitation frequency is the operating frequency of the wind turbine under different operating conditions.

[0011] In some embodiments, the process of determining whether the natural frequency avoids the excitation frequency in step S4 is as follows: S41, calculate the frequency deviation between the excitation frequency and the natural frequency. If the frequency deviation is not greater than the preset deviation, adjust the environmental control air bath system; and further verify whether the preset deviation requirement is met. S42, if the frequency deviation is greater than the preset deviation, the environmental control air bath system meets the dynamic design requirements; S43, if the frequency deviation is not greater than the preset deviation, repeat S31 to S32 to obtain the accurate natural frequency value.

[0012] In some embodiments, the preset deviation is 20% of the excitation frequency.

[0013] In some embodiments, adjusting the environmental control air bath system includes the following steps: S411. Based on the natural frequency, analyze its corresponding vibration characteristics, identify the weak components that cause resonance and their vibration direction; S412. Adjust the geometric or material parameters of the environmental control air bath system based on the control variable method according to the weak component and / or vibration direction.

[0014] In some embodiments, geometric parameters include the cross-sectional width of the frame beam of the air-controlled air bath system, the thickness of the guide plate, or the stiffness of the connection node.

[0015] In some embodiments, the current operating frequency of the fan is 50Hz; Modal analysis determined the natural frequency of the environmentally controlled air bath system to be 55Hz. Analyzing the vibration mode corresponding to the 55Hz frequency point, it was identified that it manifested as the back-and-forth swaying of the frame of the environmental control air bath system, and it was determined that the structural rigidity of the frame in this direction was insufficient. The frame was structurally strengthened using the controlled variable method, increasing the cross-sectional width of the frame beams from 1mm to 2mm. The optimized environmental control air bath system has a natural frequency of 70Hz, avoiding the operating frequency range of 40Hz to 60Hz of the fan.

[0016] In the resonance treatment method for environmentally controlled air baths disclosed in this application, dynamic modeling and frequency characteristic analysis are conducted before the environmentally controlled air bath system enters the manufacturing stage. By calculating the system's natural frequency and comparing it with the frequency of a known excitation source, key geometric or material parameters are adjusted accordingly to effectively deviate the natural frequency from the excitation frequency range, thereby preventing resonance from occurring at the design stage. This method does not require the fabrication of a physical prototype; it can identify resonance risks during the design phase and, through targeted design tuning, precisely control the natural frequency of the environmentally controlled air bath system within a safe range, significantly reducing subsequent debugging costs. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of the environmental control air bath system framework according to an embodiment of this application; Detailed Implementation The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application will be presented in conjunction with some embodiments, this does not mean that the features of this application are limited to this embodiment. On the contrary, the purpose of describing the application in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of this application. To provide a thorough understanding of this application, many specific details will be included in the following description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0018] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0019] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0022] This application provides a method for eliminating resonance in an environmentally controlled air bath. By optimizing the air bath structure design, resonance caused by external excitation sources is avoided, thereby reducing the commissioning cost of the environmentally controlled air bath system. The method is described in detail below with reference to specific embodiments.

[0023] Step S1: Establish a 3D model of the environmentally controlled gas bath system and discretize it to obtain the discretized model data. The environmentally controlled gas bath system is a key component in the lithography machine used to maintain the stability of the working environment; its structural vibration directly affects the lithography accuracy. In this embodiment, a 3D modeling software is used to generate an overall model of the environmentally controlled gas bath system. The model must include main components such as the frame, guide vanes, and connecting nodes. The frame is usually the supporting structure of the system, using high-strength materials to withstand internal airflow and external excitation sources; the guide vanes guide the airflow to ensure the uniformity of the gas bath environment; and the connecting nodes are responsible for fixing and coordinating the various components. During modeling, a high-precision geometric description method is preferred to ensure that the model can realistically reflect the physical characteristics of the system. For example, the beam structure of the frame is mainly rectangular in cross-section, and the curved surface shape of the guide vanes is optimized according to the airflow distribution. After modeling, the model is imported into the finite element (Ansys) analysis module for discretization. The discretization process decomposes the complex 3D geometry into a finite number of hexahedral elements, each with independent nodes and degrees of freedom, for subsequent numerical calculations. It should be noted that the choice of hexahedral elements effectively balances computational accuracy and efficiency, making them suitable for the complex structure of the environmental control air bath system. After discretization, the system generates model data containing nodal coordinates, element connection relationships, and boundary conditions, providing a foundation for subsequent modal analysis.

[0024] Step S11 involves generating a 3D model of the environmental control air bath system using 3D modeling software, including a frame, guide vanes, and connection nodes. In one implementation, the modeling software can be a general-purpose industrial design tool, such as AutoCAD or SolidWorks, to generate a 3D geometric model of the system. The frame is typically designed as a combination of multi-segment beam structures, with the beam cross-sectional shape determined according to stress requirements, such as rectangular or I-shaped sections, to provide sufficient rigidity. The guide vanes are designed according to aerodynamics, with smooth surfaces and specific angles to optimize airflow distribution. Connection nodes are typically constructed using bolts or welding to ensure the stability of each component. For example, in the high-precision production scenario of lithography machines, the frame length may be between 1 and 2 meters, and the thickness of the guide vanes is typically controlled to a few millimeters to balance lightweight design and strength. The modeling process also needs to consider the system's assembly tolerances to ensure that the model reflects minute deviations in actual manufacturing. This precise modeling method contributes to the accuracy of subsequent analysis and avoids misjudgments of resonance caused by geometric errors.

[0025] Step S12 involves importing the 3D model into the finite element analysis module and discretizing it into a finite number of interconnected hexahedral elements. Specifically, the discretization process is achieved through mesh generation, decomposing the 3D model into multiple hexahedral elements, each defined by eight nodes, interconnected by rigid or flexible connections. The mesh density is determined based on the system's complexity and computational resources. For example, in the stress-concentrated areas of the frame beam, the mesh density is higher to capture local stress changes; while in the smooth areas of the guide plate, the mesh density can be appropriately reduced to decrease computational load. It should be noted that hexahedral elements offer higher computational accuracy compared to other element types, making them particularly suitable for systems with high precision requirements, such as the lithography machine's environmental control gas bath. In one implementation, the discretized model contains tens of thousands of elements and hundreds of thousands of nodes, ensuring the model accurately reflects the system's dynamic characteristics. After discretization, model data containing element connection relationships and node coordinates is generated, which is directly used for subsequent modal analysis.

[0026] Step S13: Set the material parameters for each component in the discretized model, including elastic modulus, Poisson's ratio, and density. In one embodiment, aluminum alloy is specified for the frame and guide plate, as it is widely used in the lithography machine's environmental control gas bath system due to its high strength and lightweight characteristics. Aluminum alloys typically have a high elastic modulus, effectively resisting vibration deformation; Poisson's ratio reflects the material's lateral deformation characteristics; and density affects the system's mass distribution and natural frequency. For example, commonly used aluminum alloys have an elastic modulus of 70 GPa, a Poisson's ratio of 0.33, and a density of 2700 kg / m³. Exemplarily, in high-precision lithography scenarios, the setting of material parameters needs to consider the influence of temperature and humidity on material properties. For example, in a constant temperature environment of 20 to 25 degrees Celsius, the performance of aluminum alloys remains stable. After the parameters are set, it is necessary to verify whether they match the geometry of the 3D model to ensure the reliability of subsequent analysis results.

[0027] Step S131 specifies the aluminum alloy material for the frame and guide plate of the environmental control gas bath system. In the environmental control gas bath system of the lithography machine, the frame needs to withstand the impact of airflow and external excitation. Aluminum alloy can provide sufficient rigidity and stability, while the guide plate needs to balance airflow guidance and lightweight requirements. In one embodiment, 6061 aluminum alloy is selected, which has good strength and corrosion resistance, suitable for high-precision manufacturing environments. After the material is specified, detailed parameters of the material, including chemical composition and mechanical properties, need to be recorded to ensure the traceability of model data. For example, in the lithography machine production workshop, the surface of aluminum alloy materials is usually anodized to enhance wear resistance and corrosion resistance. This treatment can be indirectly reflected in the model by adjusting the surface friction coefficient.

[0028] Step S132: Set the elastic modulus, Poisson's ratio, and density of the aluminum alloy material. In one embodiment, the elastic modulus is set to 70 GPa, the Poisson's ratio to 0.33, and the density to 2700 kg / m³. These parameters are based on general performance standards for aluminum alloys and are fine-tuned according to the actual application scenario of the lithography machine's environmental control gas bath system. For example, in a high-frequency vibration environment, the selection of the elastic modulus must ensure that the frame can resist deformation caused by high-frequency excitation. The setting of the Poisson's ratio affects the simulation accuracy of the model under transverse stress. The density parameter directly affects the mass distribution of the system, and thus affects the calculation results of the natural frequency. When setting parameters, it is necessary to refer to material handbooks or experimental data to ensure the accuracy of the values. For example, if the system operates in a low-temperature environment, the elastic modulus of the aluminum alloy may change slightly and needs to be adjusted according to the actual working conditions.

[0029] Step S133 verifies the match between the material parameters and the geometry of the 3D model. In one implementation, the correctness of the material parameters is verified by simulating a simple static load test. For example, a uniformly distributed force is applied to the model, and the deformation of the frame and guide vanes is observed to see if it matches expectations. During the verification process, the stress distribution and displacement field of the model need to be checked for rationality; for example, whether stress concentration areas in the frame beams appear near the connection nodes. If anomalies are found, the accuracy of the material parameters or geometric modeling needs to be re-examined.

[0030] Step S14: Define the boundary conditions for the environmentally controlled gas bath system, simplified to a fully constrained connection with a rigid foundation. Specifically, the boundary conditions must reflect the constraint state of the system in the actual working environment. In lithography machines, the environmentally controlled gas bath system is typically fixed to a rigid base, whose stiffness is much higher than that of the system itself. Therefore, it can be simplified to a fully constrained connection, i.e., restricting the translational and rotational degrees of freedom of all nodes. In one implementation, the boundary conditions are set such that the bottom nodes of the frame are completely fixed, and the guide vanes and connecting nodes are indirectly constrained through the frame. After setting, it is necessary to check whether the boundary conditions are consistent with the actual installation method, for example, confirming whether the connection point between the frame and the base can withstand airflow and vibration loads.

[0031] Step S2 involves performing modal analysis on the discretized environmental control air bath system to determine its natural frequencies and mode shapes. Modal analysis is a crucial step in evaluating the dynamic characteristics of the system, revealing its vibration behavior at different frequencies. In one implementation, modal analysis is performed using a finite element analysis module, calculating the system's natural frequencies and corresponding mode shapes based on the geometry, material parameters, and boundary conditions of the discretized model. Natural frequencies reflect the system's natural vibration frequencies without external excitation, while mode shapes describe the system's vibration pattern at those frequencies. For example, a frame might exhibit bending vibration, and a guide vane might exhibit torsional vibration. It should be noted that the accuracy of modal analysis depends on the quality of the discretized mesh and the accuracy of the material parameters; therefore, the rigor of the aforementioned steps directly affects the reliability of the results.

[0032] Step S3 involves comparing the natural frequency with the excitation frequency of the excitation source to determine if there is a risk of resonance. The excitation source is typically the vibration generated during the operation of the lithography machine, such as the periodic force caused by motor rotation or airflow pulsation. In one embodiment, the operating frequency range of the excitation source is obtained and compared with the natural frequency obtained from modal analysis. If the natural frequency falls within the excitation frequency range, there is a risk of resonance, which may lead to amplification of system vibration or even structural fatigue. During the comparison, the frequency deviation between the natural frequency and the excitation frequency needs to be calculated, and it needs to be determined whether the frequency deviation is greater than a preset threshold.

[0033] The operating frequency range of the excitation source is obtained through experimental measurements or equipment specifications. In a lithography machine, the excitation source may include a motor, pump, or airflow control device, and its frequency range is typically determined by the machine's operating speed or airflow pulsation frequency. For example, a motor speed of 3000 rpm corresponds to a vibration frequency of approximately 50 Hz. In one implementation, the vibration signal during lithography machine operation is measured using sensors, and the frequency spectrum is extracted to determine the distribution range of the main excitation frequencies. During the measurement process, it is necessary to ensure that the sensors are installed in critical parts of the system, such as the connection point between the frame and the base, to capture the true excitation characteristics. The obtained frequency range provides a basis for subsequent comparative analysis.

[0034] Step S4: Determine if the natural frequency avoids the excitation frequency. If not, adjust the environmental control air bath system and repeat steps S1 to S3 until the natural frequency avoids the excitation frequency. In the environmental control air bath system of a lithography machine, resonance can lead to airflow instability, thus affecting lithography accuracy. Therefore, adjusting structural parameters to avoid resonance is crucial. In one implementation, the adjustment process first analyzes the proximity of the natural frequency to the excitation frequency based on the resonance risk identified in step S3, identifying key components that need adjustment. The objects to be adjusted typically include the cross-sectional dimensions of the frame beams, the thickness of the guide plate, or the rigidity of the connection nodes. After adjustment, a three-dimensional model needs to be regenerated, discretized, and modal analyzed to verify whether the natural frequency has moved out of the excitation frequency range. It should be noted that the adjustment process may require multiple iterations, repeating steps S1 to S3, to ensure that the dynamic characteristics of the system meet the design requirements. For example, in high-precision lithography scenarios, the adjusted natural frequency needs to maintain a sufficient deviation from the excitation frequency to avoid the cumulative effect of vibration during long-term operation. During the adjustment process, parameters with minimal impact on system performance are prioritized to ensure that the airflow guidance function is not significantly affected.

[0035] Step S41: Calculate the frequency deviation between the natural frequency and the operating frequency of the excitation source, and determine whether the frequency deviation is greater than a preset threshold. If the frequency deviation is not greater than the preset threshold, adjust the environmental control air bath system; and further verify whether the preset deviation requirement is met. In one possible implementation, the frequency deviation is calculated by comparing the natural frequency with the upper and lower limits of the excitation frequency range. For example, if the natural frequency is 120Hz and the excitation frequency range is 90Hz to 110Hz, the deviation is 10Hz. The calculation process needs to cover all extracted natural frequencies to ensure a comprehensive assessment of resonance risk. In one embodiment, the deviation calculation also needs to consider the dynamic changes of the excitation frequency, such as changes in the fan speed, which may also change the excitation frequency. The preset threshold is set according to the operating requirements of the lithography machine, and is usually 20% of the excitation frequency. For example, if the excitation frequency is 100Hz, the threshold can be set to 20Hz. If the frequency deviation is not greater than the preset deviation threshold, record the mode shape data corresponding to the natural frequency, and adjust the parameters of the environmental control air bath system until its natural frequency avoids the excitation frequency. The process of adjusting the environmental control air bath system is as follows: based on the natural frequency, analyze its corresponding vibration characteristics, identify the weak components that cause resonance and their vibration directions; according to the weak components and / or vibration directions, adjust the geometric parameters or material parameters of the environmental control air bath system based on the control variable method.

[0036] Step S42: If the frequency deviation is greater than the preset threshold, it is considered that the natural frequency can effectively avoid the excitation frequency, and the environmental control air bath system meets the dynamic design requirements.

[0037] Step S43: If the frequency deviation is not greater than the preset deviation threshold, repeat steps S41 to S42 until the obtained inherent frequency value avoids the excitation frequency.

[0038] Step S411: Based on the mode shapes corresponding to the natural frequencies, analyze the vibration characteristics of the environmentally controlled air bath system and identify the weak components causing resonance and their vibration directions. Specifically, mode shape data reveals the deformation patterns of the system at specific natural frequencies, such as the swaying mode of the frame or the torsional mode of the guide vane. The determination of weak components is based on the relative displacement distribution and stress concentration in the mode shapes. One implementation method is to analyze the mode shapes using a three-dimensional visualization tool to visually observe the displacement cloud diagrams and stress distribution of each component during vibration. For example, if a certain mode shape shows significant lateral bending vibration in the frame beam, the beam can be identified as a weak component, with its dominant vibration direction being lateral. Based on the vibration characteristics of the identified weak components, further determine the adjustment range of the frame beam cross-sectional width. The setting of this range needs to comprehensively consider the mechanical properties of the beam, the overall weight constraints of the system, and the feasibility of the manufacturing process. For example, if the weak direction is lateral vibration, the cross-sectional width adjustment range can be set to 1.1 to 2.5 times the current width to improve lateral bending stiffness. It is important to note that the width increment should be controlled at the millimeter level to ensure that the processing accuracy and manufacturing cost are controllable. In high-precision lithography applications, it is necessary to ensure that the cross-sectional width adjustment is coordinated with the stiffness of the connection node to avoid new stiffness abrupt changes caused by excessive or insufficient local stiffness, which could induce secondary vibration problems.

[0039] Step S412 involves adjusting the geometric or material parameters of weak components using the controlled variable method. This includes adjusting the cross-sectional width of the frame beam or the thickness of the deflector. Specifically, the controlled variable method involves adjusting individual parameters one by one and observing their impact on the natural frequency to find the optimal adjustment scheme. In one implementation, to address the lateral sway of the frame beam, the cross-sectional width is adjusted first to increase the beam's rigidity, thereby raising the natural frequency. Adjusting the thickness of the deflector needs to consider the airflow guiding function; typically, the surface shape is optimized while increasing the thickness to maintain airflow uniformity. The adjustment process incorporates a finite element analysis module to calculate the vibration characteristics after adjustment in real time, ensuring the correct adjustment direction. Adjusting material parameters requires replacing the materials in the environmental control air bath system.

[0040] Step S4121 involves progressively adjusting the cross-sectional width of the frame beams to generate an updated 3D model. Specifically, the adjustment process uses a step-by-step method, for example, increasing the cross-sectional width by 1 millimeter each time to generate a new 3D model. After adjustment, the model's geometric data needs to be updated and re-discretized to ensure that the model reflects the latest structural changes.

[0041] Step S4122: Perform modal analysis on the updated 3D model to obtain new natural frequencies. Based on the updated model data, the modal analysis repeats the calculation process of step S2 to extract new natural frequencies and mode shapes. During the analysis, it is crucial to focus on the trend of the adjusted natural frequencies, such as whether they are shifting away from the excitation frequency. In one implementation, the modal analysis results show that increasing the cross-sectional width of the frame beam increases the natural frequency from 50Hz to 70Hz, effectively avoiding the excitation frequency range of 40Hz to 60Hz. After the analysis is completed, a data report containing the new natural frequencies and mode shapes is generated to provide a basis for subsequent verification.

[0042] Step S4123: Compare the new natural frequency with the excitation frequency to determine whether the resonance avoidance requirement is met. Specifically, the comparison process repeats the frequency deviation calculation in step S3 to determine whether the new natural frequency falls outside the excitation frequency range. If the deviation of the new natural frequency is greater than a preset threshold, the adjustment is considered effective and the system meets the resonance avoidance requirement; otherwise, further adjustments to the cross-sectional width or other parameters are required.

[0043] Step S4124: If the requirements are met, save the adjusted geometric or material parameters. In one embodiment, the adjusted cross-sectional width, guide plate thickness, and other parameters are saved in file format, containing detailed geometric descriptions and mechanical property data. The saved parameters must be consistent with the 3D model, and the changes in natural frequencies before and after adjustment must be recorded for subsequent verification and traceability. For example, in a lithography machine production scenario, the saved parameters can be directly used for manufacturing process guidance, ensuring that the optimized structure can be seamlessly applied to actual production.

[0044] Step S5: Store the optimized environmentally controlled gas bath system model to the model library. The optimized model includes adjusted geometric parameters, material parameters, natural frequencies, and mode shape data, serving as a crucial basis for subsequent manufacturing and verification. It's important to note that establishing the model library enables rapid retrieval and iterative optimization during lithography machine production. For example, in different lithography machine models, the optimized environmentally controlled gas bath system model can be directly extracted from the library, reducing repetitive design work. The establishment of the model library significantly improves design efficiency and shortens the cycle from optimization to manufacturing.

[0045] like Figure 1As shown in the embodiment of this application, the excitation source is a fan, whose current operating frequency is 50Hz; the natural frequency of the environmental control air bath system is determined to be 55Hz through modal analysis; the vibration mode corresponding to the 55Hz frequency point is analyzed, and it is identified that it is manifested as the back-and-forth swaying of the environmental control air bath system frame, and it is determined that the structural rigidity of the frame in this direction is insufficient; the frame is structurally strengthened based on the control variable method, and the cross-sectional width of the frame beam is increased from 1mm to 2mm; the natural frequency of the optimized environmental control air bath system is 70Hz, avoiding the operating frequency range of 40Hz to 60Hz of the fan.

[0046] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A resonance treatment method for an environmentally controlled gas bath, characterized in that, include: S1. Establish a three-dimensional model of the environmental control air bath system and discretize the three-dimensional model; S2. Perform modal analysis on the discretized environmental control air bath system to obtain the natural frequencies and mode shapes of the environmental control air bath system; S3. Compare and analyze the natural frequency with the excitation frequency of the excitation source; S4. Determine whether the natural frequency avoids the excitation frequency. If it does not avoid it, adjust the environmental control air bath system and repeat steps S1 to S3 until the natural frequency avoids the excitation frequency. S5. Store the finalized model of the environmental control air bath system into the model library.

2. The resonance processing method as described in claim 1, characterized in that, In step S1, the process of establishing a three-dimensional model of the environmental control air bath system and discretizing the three-dimensional model is as follows: S11. Use CAD software to create a three-dimensional model of the environmental control air bath system; S12. Using the Ansys module, import the three-dimensional model established in S11, and discretize the model into a finite number of interconnected simple elements, wherein the simple elements are hexahedral elements. S13. After the discretization is completed and checked to be correct, set the material parameters of each component in the environmental control air bath system. S14. Define the boundary conditions of the environmental control air bath system, simplify the interaction between the environmental control air bath system and the foundation or rigid foundation, and treat the boundary conditions as fully constrained.

3. The resonance treatment method as described in claim 2, characterized in that, In step S13, the material parameters are as follows: the model material is aluminum alloy, elastic modulus: 70 GPa, Poisson's ratio: 0.33, density: 2700 kg / m³.

4. The resonance treatment method as described in claim 1, characterized in that, In step S3, the excitation source is a fan; the excitation frequency is the operating frequency of the fan under different operating conditions.

5. The resonance treatment method as described in claim 1, characterized in that, In step S4, the process of determining whether the natural frequency avoids the excitation frequency is as follows: S41, calculate the frequency deviation between the excitation frequency and the natural frequency. If the frequency deviation is not greater than the preset deviation, adjust the environmental control air bath system; and further verify whether the preset deviation requirement is met. S42, if the frequency deviation is greater than the preset deviation, the environmental control air bath system meets the dynamic design requirements; S43, if the frequency deviation is not greater than the preset deviation, repeat S31 to S32 to obtain the accurate natural frequency value.

6. The resonance treatment method as described in claim 5, characterized in that, The preset deviation is 20% of the excitation frequency.

7. The resonance treatment method as described in claim 5, characterized in that, The adjustment of the environmental control air bath system includes the following steps: S411. Based on the natural frequency, analyze its corresponding vibration characteristics and identify the weak components that cause resonance and their vibration direction; S412. Adjust the geometric or material parameters of the environmental control air bath system based on the control variable method according to the weak component and / or vibration direction.

8. The resonance treatment method as described in claim 7, characterized in that, The geometric parameters include the cross-sectional width of the frame beam of the environmental control air bath system, the thickness of the guide plate, or the stiffness of the connection node.

9. The resonance processing method as described in claim 8, characterized in that, The current operating frequency of the fan is 50Hz. Modal analysis determined the natural frequency of the environmentally controlled air bath system to be 55Hz. Analyzing the vibration mode corresponding to the 55Hz frequency point, it was identified that it manifested as the back-and-forth swaying of the frame of the environmental control air bath system, and it was determined that the structural rigidity of the frame in this direction was insufficient. The frame was structurally strengthened using the controlled variable method, increasing the cross-sectional width of the frame beams from 1mm to 2mm. The optimized environmental control air bath system has a natural frequency of 70Hz, which avoids the operating frequency range of 40Hz to 60Hz of the fan.

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