Isolation tables used in semiconductor factories are generally classified as non-structural elements. However, isolation tables installed for vibration control are integrated with fabrication facility (FAB) structures and can change the natural frequency of the overall system. In this study, a basic FAB lattice structure and a combined model with isolation tables were modeled using ANSYS Workbench. Modal and frequency response analyses showed that the natural frequency of the basic FAB structure (15.644 Hz) changed to 12.75 Hz ~ 19.75 Hz depending on the isolation tables and type of foundation. These results indicate that isolation tables can contribute to the structural behavior of FAB structures and should be considered in the design of vibration-sensitive semiconductor factories.
Lim et al. (Fri,) studied this question.