| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a control method for efficiently and accurately regulating the temperature of a chuck in a low temperature region. SOLUTION: A pump 18 feeds a coolant 15 stored in a low temperature tank 16, to a coolant passage 14 of a chuck 10 and also to a refrigerator 17. The coolant cooled by the refrigerator is returned to the low temperature tank through a return passage 20. The temperature change of the coolant in the low temperature tank is detected as the electric resistance change of a resistance bulb 19, and on the basis of this, a regulating valve 21 provided in the return passage is controlled to regulate the flow of the coolant flowing in the return passage, thus controlling the temperature of the coolant in the low temperature tank. The chuck is provided with a heater 13 for direct heating.</p> |
