TEMPERATURE AND CONCENTRATION CONTROL APPARATUS OF H3PO4 BY CYCLE TYPE METHOD

摘要

The present invention can control the concentration automatically by controlling the temperature of phosphoric acid by using the cycle method, so that the etch rate according to the stabilization of temperature control can be maintained uniformly, and the production stop due to the malfunction of the level sensor can be prevented. It is possible to reduce the manpower and time required for temperature control and error occurrence, and to increase the yield.;To this end, this proposal connects the internal and external timers (6) and (7), which determine the supply of deionized water and phosphoric acid, to a temperature monitor (3) connected to a temperature sensor (2) in the bath (1). It is a device for controlling the temperature and concentration of phosphoric acid by a cycle method in which deionized water and phosphoric acid are automatically supplied by setting a time in the sequence according to the change.