| 摘要 |
PURPOSE:To reduce the size of a device and to decrease the influence of dust by putting circular table into a case and segmenting and forming plural chambers in which the air pressure decreases stepwise from the atm. pressure to a high vacuum by sealing means in the case. CONSTITUTION:The substrate to be worked is attached into a pocket 18 from a substrate carrying in and out port 16. The spaces I, II, III, IV are respectively thoroughly separated from each other in this state. The spaces I and II is coupled by the pocket 18 and the spaces III and IV by a pocket 17 when the circular table 1 rotates. The same pressure is thus maintained between both chambers. The spaces II and III are separated by an O-ring 45 and the flow of the air from the space I to IV does not arise. The inside of the space III is evacuated to the higher degree of vacuum than the degree of vacuum in the space II as the table 1 is further totated. The pocket 18 arrives at a connecting port 19 and is connected to a vacuum vessel 3 at the next index. The another pocket 17 arrives at the port 16 where the substrate is carried in or out while the welding, etc. are executed in this state. |
