Trial experiments to reduce temperature changes in an air spring of air type anti-vibration apparatus

Abstract

In industrial scenes, pneumatic anti-vibration apparatuses having both air springs and voice coil motors are widely implemented in semiconductor exposure apparatuses for suppression of disturbance and improvement of vibration transmissibility. Since it is necessary to reduce effect of heat in the semiconductor manufacturing, the voice coil motors, which are exactly heating elements, are forcibly cooled down. Moreover, for a lot of space of the exposure apparatus, temperature is locally managed by means of air conditioning. However, the temperature in the air springs changes due to the intake and exhaust of high pressure air, it has not been managed in semiconductor industries. For the above reason, the heat radiation from the air springs affects the semiconductor manufacturing probably. Furthermore, the pressure in the air springs changes in accordance with the inner temperature. It results in the performance degradation of pressure control. To overcome the temperature changes of the air springs, this paper discusses the suppression of temperature change in air springs used for an anti-vibration apparatus. The thermal equivalent circuit, which corresponds to the heat transfer of the air springs, are derived in order to create mechanical and electrical temperature reduction methods, and to evaluate experimental results. Based on measurement results of the temperature changes and the thermal equivalent circuit, four methods are proposed so as to suppress the temperature change.