| 摘要 |
PROBLEM TO BE SOLVED: To prevent the breakage of a vacuum pump in making a wafer sucked to and separated from a pressure plate of a pressure plate device. SOLUTION: This air circuit is used for vacuum suction and separation of a wafer by a pressure plate 13 constituting a sheet type, single-sided polishing machine. The air circuit is provided with a vacuum circuit 21, which is for keeping a wafer sucking part 13a at the negative pressure, an air supplying circuit 20, which is for supplying the air to the wafer sucking part 13a, and a demineralized water supplying circuit 22, which is for supplying the demineralized water to the wafer sucking part 13a. An electromagnetic valve 32 is arranged in the vacuum circuit 21, so that the vacuum circuit 21 is connected to the wafer sucking part 13a while the air supplying circuit 20 is cut off. |
