Abstract
In industrial scenes, semiconductor exposure apparatuses have pneumatic anti-vibration apparatuses. It can produce high-performance ICs by raising exposure precision by removing vibration. It is known that exposure precision is affected by temperature change. Therefore, the voice coil motors which are large heating element are cooled down by water. Moreover, the sensor and LED which are small heating element are cooled down by air. The temperature of inner air of exposure apparatus is locally managed by means of air condition. However, the temperature in the air springs changes due to pressure change which is caused anti-vibration; it has not been managed in semiconductor industries. On the other hand, it is reported that the pipe connecting to an air spring has condensation in semiconductor industries. Moreover, the temperature changes of air spring affect to precision pressure and position control. For the above reason, the heat radiation from the air spring affects the semiconductor manufacturing probably. Therefore, this paper proposes new method of restraining temperature change of air springs which is based on heat equivalent circuit. At first, it is confirmed that the methods of flow-design and piezo-fan as mechanical technique are effective in temperature change restraint. However, the method of flow-design must have air flow in the air spring at all time. Moreover, that method of piezo-fan needs processing of the metal case of air spring and also generates heat. In order to solve these disadvantages, the method of twin-valves is proposed as fusion of mechanical and electrical methods. This method does not generate heat and it does not need processing of the metal case of air spring. Moreover, twin-valves can generate air flow at all time. Hence, it influences the temperature change suppression of air spring of anti-vibration apparatus at levitation. Furthermore, it achieves a further more temperature change suppressing effect by the method of combination of twin-valves and flow-design.
