DRUM MASK WITH LOWER DRUM MASK

摘要

PURPOSE: A drum mask is provided to prevent arc caused by particles by quickly replacing a lower drum mask contaminated with particles. CONSTITUTION: A drum mask(155) comprises a lower drum mask(160) which is shaped corresponding to the backside of the drum mask. The lower drum mask has a through hole corresponding to a center hole(157) and a protruding cover extended from the interior of the hole. The lower drum mask is fixed to the backside of the drum mask by a bolt that is coupled to a tap hole of the drum mask through a bolt hole of a lower drum mask body.