NPO dielectric ceramic compositions and capacitors made therefrom

摘要

A low temperature fired NPO type ceramic dielectric composition is employed for making high frequency multi-layer capacitors having dielectric constants between 25 and 40 at room temperature, and which do not vary from this base line value by more than +/-30 parts per million (PPM)/ DEG C. over a temperature range of -55 DEG C. to +125 DEG C. with the value at +25 DEG C. being the reference point. The dielectric composition is made from a base dielectric ceramic formulation and a low melting point glass formulation, each derived from metal oxides or precursors thereof. Manganese dioxide or a precursor thereof may be added in the amount of from about 0.012 to 0.060 weight percent as the dioxide based on the combined weight of the ceramic formulation and the glass formulation. The mixtures, when made into multi-layer ceramic capacitors (MLCC), are fired at or below 1120 DEG C.