METHOD OF FEEDING WASHING LIQUID FOR REAR OF SUBSTRATE FOR ROTARY COATING AND DEVICE THEREFOR

PURPOSE: To solve problems on heat generation and sealing of the boundary surface with a rotating shaft with respect to a feeding method of washing liquid for preventing and removing unnecessary coating on the rear of a substrate to be coated in a rotary coating device using centrifugal force to apply a liquid extremely thin. CONSTITUTION: In a rotary coating device, a blow-out port 19 for a washing liquid with which a coating liquid going around to the rear of a substrate during coating is washed is installed on the outer periphery part of a substrate receiving base 2 integrally constituted with a spin shaft 27, and also a washing liquid flow passage connected to the washing liquid blow-out port 19 is passed through the spin shaft 27 downward, and the lower end part of the rotating shaft is immersed in a washing liquid 100 in a washing liquid forced feeding vessel 32, and besides a part of the pin shaft 27 entering the washing liquid forced feeding vessel 32 is made a labyrinth seal 32, which is a non-contact type seal, and since there is no heat generation from this part, temperature rise of the substrate is prevented.