Balance control

Challenge

The stage-base has to be kept horizontal to process the wafer accurately.
The movement of the gantry or X/Y table inclines the stage-base with its weight. The inclination has to be measured and corrected, for which high speed and non-contact measurement is required.

Solution

Omron offers accurate gap-measurement sensors employing eddy current methods.
The separation of sensor head, pre-amplifier and amplifier enables measurement of the gap in several kinds of metal with linearity and repeatability.
The separate amplifier eliminates heat emission to the process itself and enables a constant temperature around the sensors.

Benefit

Accurate and high-speed balance control enables a high-quality process.
Sensing within a clean environment improves the yield