| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum retaining equipment which can retain a vacuum state even without electric power. SOLUTION: One end of a first solenoid 14 is connected to an intake port 11, and the other end of the first solenoid 14 is connected to a gas inlet 131 in a vacuum generator 13. In operation with an electric power, gas flows through the first solenoid 14 and is introduced into the gas inlet 131 in the vacuum generator 13 to generate vacuum output. One end of a second solenoid 15 is connected in parallel to the intake port 11 and a vacuum outlet 133 in the vacuum generator 13, and the other end of the second solenoid 15 is connected to an output port 12. The output port 12 can be brought to gas output or vacuum output by operating the second solenoid 15. One end of a changeover switch 16 is connected to the intake port 11, and the other end of the changeover switch 16 is connected to the vacuum generator 13. In a normal operation, the changeover switch 16 is closed. Upon the occurrence of an unexpected absence of electric power, the changeover switch 16 is opened. In this case, a gas source is supplied through this passage into the vacuum generator 13 to continuously generate vacuum and to continuously perform wafer adsorption. COPYRIGHT: (C)2009,JPO&INPIT
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