| 摘要 |
PURPOSE:To prevent the whirling-up of foreign matters and to shorten times required in evacuation operation and atmospheric leak operation, by reducing the abrupt pressure change in a vacuum chamber when the evacuation of a vacuum apparatus and the atmospheric leak thereof are started. CONSTITUTION:In a vacuum apparatus wherein a vacuum chamber 1 and a vacuum pump 7 are connected by a pipeline and a valve 3 is interposed in said pipeline, a throttle means 15 is provided between the vacuum chamber 1 and the valve 3 while a buffer chamber 16 is arranged between the means 15 and the valve 3 and a leak gas source 13 is connected to the buffer chamber 16 through a leak valve 9 and a leak arranged pipe 8. As the result, because the abrupt pressure change in the vacuum chamber 1 at the beginning is reduced when pressure is rised and lowred, there is no fear for whirling up foreign matters in the vacuum chamber 1 and the lowering of yield due to adhesion of foreign matters is prevented. In addition, the time change rate of pressure during a pressure lowering period and a pressure raising period can be arbitrarily set and, therefore, times required in lowering and raising pressure can be shortened. |
