Colin G. Gordon
The low-frequency ambient vibration existing on the ground is an important parameter in the siting of buildings that will contain equipment and processes that are sensitive to vibration. Such equipment is commonly used in "wafer fabrication plants" in which integrated circuit "micro-chips" are manufactured.
Over the past 10 years or so, BBN Laboratories has undertaken ambient vibration studies at more than 60 sites spread throughout the United States and in some overseas countries also. The frequency range of interest in these studies has typically covered 5 Hz through 100 Hz. It is within this range that most sensitive equipmentÜmicroaligners, steppers, E-Beam systems, probe test systems, etc.Üexhibits vibration-related problems. The problems, typically, are caused by low-order resonances that cause relative motion within the equipment. In this paper, let me present a brief overview and discussion of some of these data.
Reprinted from Proceedings of Noise-Con 87, State College, Pennsylvania (June 1987), pp. 233-238.