US Patent 7948516 Position accuracy evaluation method and position accuracy evaluation apparatus

According to a related art for evaluating the position accuracy of heaters with respect to the plate, it is necessary to attach an energizing electrode to the heaters, and energize the heaters for a predetermined period to heat the entire plate, before measuring the temperature distribution map. Therefore, there is a problem in that several tens of minutes are required until the temperature distribution map can be measured. As the plate becomes larger, the time required for energizing the heaters to heat the entire plate becomes longer. A technique for evaluating the position accuracy of heaters with respect to the plate, without executing a process for energizing the heaters to heat the plate is disclosed.