| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum device having a small power consumption and a small occupation area of the device, free of the risk that impurity gases go around into vacuum vessels from the exhaust system, and capable of allowing a large rate of gas to flow. SOLUTION: The vacuum device is equipped with a plurality of vacuum vessels furnished with a gas lead-in hole and an exhaust hole, a gas supply system for introducing the desired gas from the gas lead-in hole into the vacuum vessels, and an exhaust system for keeping the vacuum vessels in the decompressed condition, wherein the exhaust system has a plurality of vacuum pumps connected in series at stages, and among the vacuum pumps, ones with a lower degree of vacuum is located the nearest to the vacuum vessels, and a plurality of low vacuum pumps are connected through common piping to the final stage vacuum pumps. The exhaust hole pressure of each final stage vacuum pump is approximately the atmospheric, and the final stage vacuum pumps are arranged so that each of them exhausts the gas from a plurality of pre-stage vacuum pumps. COPYRIGHT: (C)2004,JPO&NCIPI
|
