Method of producing electrical capacitors

摘要

In a method of producing electrical capacitors, a semiconductor ceramic body made of strontium titanate doped with niobium or tantalum is sintered in a reducing atmosphere. Bismuth oxide is diffused into the sintered reduced ceramic body along with additives in an oxidising atmosphere, and in this process grain boundary barrier layers are formed. So that the bismuth oxide is always diffused in in a precisely known quantity even during mass production, bismuth nitrate is dissolved in dilute nitric acid and the solution obtained in this way is applied to the reduced ceramic body, for example, by dropping or spraying.