US Patent 7878375 Chemical liquid supply device

A chemical liquid supply device applies chemical liquid from a nozzle to a processed object. The nozzle is provided in a moving head, which reciprocates between an applying position and a waiting position and includes an application valve operating so as to take an applying state of applying the liquid from the nozzle and a stopped state of stopping the application. Chemical liquid is pumped from a tank through a filter to a valve chamber of the application valve via a supply tube. The valve chamber is connected to a buffer tank through a circulation tube. The circulation tube is provided with a circulation valve for opening/closing its flow path.