Patent ID: 6494967
Filing Date: 2002-12-17
Classification: B08B,G05D,H01L,Y10S

Abstract:
A flow rate controlling method of a down-flow type chemical treating apparatus in which a liquid treating chemical is supplied from the outside of a treating bath while the liquid treating chemical is discharged from the bottom portion of said treating bath, said flow rate controlling method of the chemical treating apparatus comprising the steps of:detecting the amount of the liquid treating chemical supplied to said treating bath; and discharging almost the same amount of the liquid treating chemical as said detected amount of the liquid treating chemical from said treating bath, wherein: said treating bath consists of a main bath and an outer bath provided on the top periphery of said main bath allowing to form a liquid level higher than an upper edge of said main bath; the liquid level of the liquid treating chemical stored in said main bath and the liquid level of the liquid treating chemical stored in said outer bath are detected; and the amount of discharge of said liquid treating chemical is controlled so that said detected liquid level of the liquid treating chemical in the main bath and of the liquid treating chemical in the outer bath are kept at a predetermined level.