Diaphragm valve, substrate processing unit and substrate processing apparatus

摘要

A first diaphragm adheres to a valve seat thereby closing a passage, and separates from the valve seat thereby opening the passage. A link rod couples a second diaphragm identical in shape to the first diaphragm for opening/closing with the first diaphragm. Therefore, the second diaphragm is mechanically interlocked with the first diaphragm, to compensate for volume change caused in a downstream passage when the first diaphragm is worked. Also when the first diaphragm is rapidly worked, therefore, the second diaphragm immediately compensates for subsequent volume change so that no resist is pulled back to or extruded from the downstream passage. Thus provided is a diaphragm valve capable of stably supplying a solution also when a valve is opened/closed.