The Modal Analysis And Optimization Design Of The Main-plate For Lithography

Dynamic properties analysis and structure optimal design about components of Lithography are the reserchful emphases in this field. The position of the main-plate determines that vibration of the main-plate has influenced the performance and stability of the Lithography. The size of the main-plate also influences the system's scale in some way. A series of researches on the vibration properties of the main-plate of Lithography are processed combining with modal analysis technology. We conduct the optimal design using dynamic optimal design theory.Firstly, in order to create a series of structure models through modifying structure parameters, choose the best optimal parameter and reduce study time, this paper foundeds the parameter model. Based on the parameter model, we researchs FE modeling methods of the main-plate through studying the structure, and the FE model of main-plate is set up. Subsequently, modal analysis is processed to this FE model using experiment modal analysis and theory modal analysis. We first condust the theory modal analysis to the FE model, and get its dynamic property parameter including natural frequency, modal shape and damping ratio etc. Subsequently, we conduct the experiment modal analysis in the same conditions. Two results show that FE modeling method is reasonable. Based on the results of the finite element methods and the demand of the design, optimization design is carried out. In order to confirm the best optimal searching directions of the dynamic optimal design and set up iterative formulas, this paper carries out the sensitive analysis of the main-plate. At last we choose six design variables. In succession we use the dimension and dynamic property as limiting conditions, use the mass of the main-plate as the goal function to build the math model of the optimization design for the main-plate. At last, we carry out the dynamic optimal design.The study result shows that dynamic properties of the main-plate is good, further more, the mass decreases largely. So it saves the valuable material and reduces the scale of the Lithography. The conclusion of the paper is valuable in improving original product design farther.