ETCHING METHOD OF METALLIC PLATE AND REGENERATING METHOD OF ETCHING SOLUTION

摘要

PURPOSE:To return the etching soln. to be used cyclically for metallic iron-Ni based plates to the original state having etching power by modifying and separating the Ni compsn. having no etching power formed in the etching soln. CONSTITUTION:An original mask plate enters an etching chamber 1 where the plate is perforated with aperture holes by an etching soln. consisting of FeCl3. The etching soln. is pumped P1 from a tank 4 into the chamber 1 and is ejected from a manihold 2, then the soln. returns into the tank 4. Lines 6-8 for feeding gaseous chlorine which is a regeneration agent, water and HCl are provided to the circulating system of the etching soln. A specified volume of the soln. from the tank 4 is pumped P2 to a separator system where an oxime reagent is added to the soln. in a reaction tank 10 to modify the Ni<2+>-contg. compsn. to a precipitate. The Fe<2+> contg. compsn. does not react in this stage. Said precipitate is separated and discharged with a filter 12 and the filtrate is returned to the tank 4 after the temp. is controlled in a heat exchanger 14.