Rotary-cup coating apparatus and method of coating object with such rotary-cup coating apparatus

摘要

A suction chuck and an inner cup are rotated in unison with each other to spread a coating solution uniformly over a planar object in the inner cup under centrifugal forces. Vent holes defined in an outer cup lid which closes an outer cup are held out of communication with vent holes defined in a ring-shaped closure member, so that the interior space in the outer cup is kept out of communication with the exterior space around the outer cup. The concentration of a solvent in the outer cup remains so high that no mist is produced in the outer cup. After the planar object has been coated and before the outer cup lid is opened, the ring-shaped closure member is turned to align the vent holes in the outer cup lid with the vent holes in the ring-shaped closure member, breaking any vacuum in the outer cup with ambient air introduced through the vent holes into the outer cup. Thereafter, the outer and inner cup lids are opened, and the coated planar object is taken out.