Improved ceramic compositions for high stability capacitors

Abstract

Abstract A ceramic composition useful in forming capacitors and having the following composition expressed in mole percent of the metal oxides present: NEODYMIUM OXIDE - ABOUT 12 TO ABOUT 20 MOLE PERCENT; BARIUM OXIDE - ABOUT 12 TO ABOUT 20 MOLE PERCENT; TITANIUM OXIDE - ABOUT 60 TO ABOUT 70 MOLE PERCENT; BISMUTH OXIDE - ABOUT 1.5 TO ABOUT 5 MOLE PERCENT; ZIRCONIUM OXIDE - 0 TO ABOUT 5 MOLE PERCENT; STANNIC OXIDE - 0 TO ABOUT 5 MOLE PERCENT; CALCIUM OXIDE AND/OR STRONTIUM OXIDE - 0 TO ABOUT 10 MOLE PERCENT RARE EARTH OXIDES OTHER THAN NEODYMIUM OXIDE - RANGING UP TO ABOUT ONE MOLE PERCENT BUT PREFERABLY LESS THAN ABOUT 0.6 MOLE PERCENT; TITANIUM OXIDE + STANNIC OXIDE + ZIRCONIUM OXIDE - ABOUT 60 TO 70 MOLE PERCENT, AND BARIUM OXIDE + CALCIUM OXIDE + STRONTIUM OXIDE - ABOUT 12 TO ABOUT 25 MOLE PERCENT. A dense, substantially non-porous, ceramic dielectric material fired at a suitable temperature within the range of about 1220*C to about 1300*C., having a K value of about 55 to about 90, a temperature coefficient of dielectric constant (TC) of about -100 to about +100 X 10 6/*C, a % D.F. less than 0.1, and an insulation resistance corresponding to values of at least about 200 ohm-farads ranging up to about 40,000 or more ohm-farads at 125*C.

Inventors

• 👤 R Roup

Bibliographic Details