... there are very fine circuit. 220V power supply, etching water flow circuit board slowly, because of water ... extremely slow, there are very fine circuit boards. etching a PCB takes only 10 minutes. Worktable use ... to work, do not directly touch ferric chloride etching solution.2, box before, please do not ... power supply to ensure safety.3, when the etching solution were not filtrated and cleared, do not ...