Review of Generic and Manufacturer Design Criteria for Vibration-Sensitive Equipment

摘要

The instrumentation employed today in fields such as nanotechnology require equipment such as scanning electron microscopes, lithography steppers, and nanoindenters, whose performance depends on micron-level precision. For example, in a scanning electron microscope, the electron beam used to scan the object must not be interrupted or misguided if an accurate image is to be produced. Even the slightest vibration transferred from the supporting structure can disturb the equipment's performance. The structural engineer must design a structure to house this equipment while meeting these strict vibration limits. Because the structural design usually precedes the selection of equipment, the engineer is often utilizes generic design criteria to design the supporting structure. The generic design criteria and manufacturer-specified design criteria are often in unfamiliar terms. This study examines and interprets several manufacturer-specified design specifications and how they relate to the industry's current generic design criteria. Terminology, metrics, and conversion methods are explained so that the manufacturer-specified criteria can be properly interpreted. Recommendations are made for specifying complete design criteria and for the cautious use of the generic design criteria.