COG dielectric with high K

• US 5,116,790 A
• Filed: 11/16/1990
• Issued: 05/26/1992
• Est. Priority Date: 11/16/1990
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Burn, Ian, Bruno, Salvatore A.
• Primary Examiner(s): Dixon, Jr., William R.
• Assistant Examiner(s): SCHULL, LISA
• Application Number:
  US07/614,550
• Time in Patent Office: 557 Days
• Field of Search: 501/137, 501/138, 501/139, 428/699, 361/321 CC
• US Class Current: 501/139
• CPC Class Codes: C04B 35/462 based on titanates
• CPC Class Codes: H01G 4/1254 based on niobium or tungsteen, tantalum oxides or niobates, tantalates

Abstract

A composition consisting essentially of 60.0-70.0 mol % TiO₂, 14.3-20.0 mol % Nd₂ O₃, 11.0-16.7 mol % BaO, 1.0-8.0 mol % ZrO₂ and 0.05-0.30 mol % CeO₂. This composition is useful for forming densified ceramic dielectric bodies having a dielectric constant of at least 65 and which meet COG specifications, and multilayer capacitors that contain such dielectric bodies.

Claims

1. A composition of a COG densified dielectric body, composition consisting essentially of:

(a) 60.0-70.0 mol % TiO₂ ;

(b) 14.3-20.0 mol % Nd₂ O₃ ;

(c) 11.0-16.7 mol % BaO;

(d) 1.0-8.0 mol % ZrO₂ ; and

(e) 0.05-0.30 mol % CeO₂.

2. The composition of claim 1 wherein (a) through (e) are chemically co-precipitated then calcined to form the composition.

3. The composition of claim 2 consisting essentially of

(a) 64.0-67.0 mol % TiO₂ ;

(b) 18.0-19.0 mole % Nd₂ O₃ ;

(c) 12.8-13.0 mol % BaO;

(d) 1.5-3.0 mol % ZrO₂ ; and

(e) 0.15-0.25 mol % CeO₂.

4. The composition of claim 1 further comprising an organic medium containing a solution of volatile organic solvent and organic polymeric binder.

5. A dielectric sheet comprising a cast layer of the composition of claim 4 which has been heated to remove volatile organic medium.

6. A dielectric ceramic layer comprising the sheet of claim 5 which has been fired to volatilize the organic medium therefrom and to densify the inorganic components by sintering.

7. A capacitor comprising a plurality of the dielectric ceramic layers of claim 6, and at least two metal electrodes which are separated from each other by at least one said dielectric ceramic layer, the assemblage having been fired at a temperature above 1240°

C. to volatilize organic medium, densify the inorganic materials in the dielectric sheets and sinter the metal electrodes.