Applicability of Seismic Protective Systems to Structures with Vibration-Sensitive Equipment

Abstract

The paper summarizes the feasibility study of implementing seismic protective systems into high-tech industrial structures in which costly vibration-sensitive facilities are housed. Due to the fact that the microvibration of an existing integrated circuit (IC) fab structure plays an important role in affecting the chip probe yield of manufacturing and the reliability of chip products, the paper has emphasized on the microvibration analysis and measurement of a test structure before and after the seismic protective systems have been incorporated. The theoretical background of one-third octave frequency spectra is derived. Based on the study, it is found that the incorporation of viscous dampers will not only enhance the seismic safety but also minimize the microvibration of the structure. The seismic isolation design is the most promising method to achieve the “fully operational” seismic performance level of an IC fab. However, the amplification of the microvibration at the low frequency range due to the implementation of seismic isolation design will require further study to ascertain its effect on the operation of vibration-sensitive facilities.