Patent ID: 6350406
Filing Date: 2002-02-26
Classification: H01G

Abstract:
A method of manufacturing a sintered anode unit for a solid electrolytic capacitor having a low content of oxygen, comprising the steps of:sintering a pellet obtained by press-molding or compacting a metal powder having a valve action, at a predetermined high temperature and in a primary vacuum degree; performing natural cooling of the pellet in the primary vacuum degree; thereafter shifting the pellet into an inert gas atmosphere; performing force cooling of the pellet in the inert gas atmosphere; shifting the pellet into a gradual-oxidizing chamber of the primary vacuum degree; leaking the atmospheric gas into the gradual-oxidizing chamber to lower the vacuum in the gradual-oxidizing chamber than the primary vacuum degree; returning the vacuum level in the gradual-oxidizing chamber to the primary vacuum degree; repeating this cycle of vacuum, atmospheric leakage, and vacuum in the gradual-oxidizing chamber, thereby increasing the atmospheric leakage level step by step to set the vacuum level in the gradual-oxidizing chamber to the atmospheric pressure; and taking out the sintered pellet from the gradual-oxidizing chamber into the atmosphere.