Liquid spreading machine for producing thin even material layer on substrate has silicon substrates on conveyer belt and has ultrasonic generator in hopper producing mist falling on substrates

摘要

The coating machine (10) has a transport system (13) consisting of a conveyer belt (29). It carries silicon substrates (12) into a hood (41) in which they are exposed to a mist (15) of phosphoric acid. An ultrasonic generator (11) in the supply hopper (14) has a piezoelectric element and a quartz glass nozzle (68) drawing in liquid and projecting just above the liquid surface (20). The mist goes down a shaft (25) to the hood, and is sucked out of the end of the hood through a woven plastics layer (45) into a suction chamber (43) by a pump (48). An overflow arrangement (52-57) moves overflow liquid to a holding tank (19).