| 摘要 |
PROBLEM TO BE SOLVED: To prevent damages to an air spindle, even in cases like instantaneous power failure or power failure, or decline in the pressure of compressed air. SOLUTION: When an instantaneous power failure or a power failure is detected in a commercial power supply by a detector 3, power is automatically switched to power for backup which is generated by an uninterruptible power supply 2; and at the same time, a drive mechanism for a stage to be mounted with a semiconductor wafer is stopped, and the air spindle is moved upward to a safe place to protect a semiconductor wafer. A spindle inverter 7, which is supplied with the power for backup of the uninterruptible power supply 2 forcibly stops the air spindle 6. Furthermore, when the reduction in pressure of compressed air at the plant side is detected by a pressure sensor 4, a spare air tank 5 switches the compressed air on the factory side to compressed air of the spare air tank 5 and then supplies it to the air spindle 6. |
