CAPACITOR WITH NON-NOBLE METAL ELECTRODES AND METHOD OF MAKING THE SAME

摘要

CAPACITOR WITH NON-NOBLE METAL ELECTRODES AND METHOD OF MAKING THE SAME A ceramic capacitor having electrodes. The capacitor is formed by cosintering layers of ceramic dielectric and layers of non-noble metal material indifferent to the dielectric layers corresponding in area and position to the electrodes. The indifferent layers are converted to a conductive state, for example, by chemical conversion and used as such or are removed and replaced by metal or conductive material. One example in which the indifferent layers comprise nickel oxide involves stacking layers of green ceramic coated with nickel oxide in the desired electrode pattern, sintering the stacked layers to produce a monolith, reducing the nickel oxide in the monolith to metallic nickel in a hydrogen atmosphere at a temperature low enough to have minimal effect upon the dielectric properties of the ceramic and using the metallic nickel as reduced for the ceramic capacitor electrodes. In another example, after the reduction step ( which may be at high temperature) the metallic nickel is dissolved, for example by sulfuric acid, the ceramic monolith is reozidized by firing in an oxidizing atmosphere such as air, and the voids left by removal of the dissolved metallic nickel are provided with suitable electrodes. In still another example, in which the indifferent layers comprise oxidizable material such as carbon, the stacked layers are sintered in an inert atmosphere to produce a monolith of matured ceramic and the indifferent layers are removed by subsequent firing in an oxidizing atmosphere to produce the voids for receiving conductive electrode material.