| 摘要 |
<p>A vacuum chuck (9) which can be operated both in gas and in liquid is provided with a liquid-gas separating membrane (8) having a plurality of tiny holes which allow passage of gas molecules but do not pass liquid. The liquid-gas separating membrane (8) is spanned between an inlet hole (3, 5) of the chuck and a manifold (4) which, in operation of the chuck, is connected to a pneumatic system (129). The pneumatic system (129) comprises an aspirator (10), a compressor (11) and a switching valve (12). The vacuum chuck (9) is immersed into a liquid (13), compressed gas purges the liquid in the inlet hole (3), then the switching valve (12) is switched to the aspirator (10). So, an object such as a semiconductor wafer (7) is sucked quickly to the chuck (9), and the inlet hole (3, 5) is closed by the object (7). If a small quantity of liquid intrudes into the chuck (9), it cannot pass through the liquid-gas separating membrane (8), and operation of the chuck (9) is not harmed.</p> |
