Ceramic dielectric compositions and method for improving sinterability
AssigneeE. I. Du Pont de Nemours and Company
InventorsHoracio E. Bergna, Ian Burn
Life of this patent
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Abstract
An improved ceramic dielectric composition for preparing multilayer ceramic structures for electronic devices and a method of enhancing the sinterability of such compositions at low firing temperatures by improving the distribution of zinc borate based sintering flux uniformly throughout the composition.
Claims13
A method for enhancing the sinterability of ceramic dielectric composition comprising uniform coated particles of ceramic powder according to the steps of:
- (a) mixing sintering flux component precursors with the ceramic powder whereby the flux component precursors form a uniform coating comprising primarily zinc borate on each particle wherein said coating comprises less than about 50% by weight of the coated particle;
- and
- (b) drying and optionally calcining the coated particles.
An improved dielectric ceramic powder composition comprising particles of ceramic powder, each particle having a uniform coating of a sintering flux comprising primarily zinc borate which comprises less than 50% by weight of the powder and has a molar ratio of ZnO to B.sub.2 O.sub.3 of from 1/2 to 5/1, and which is formed by the process of:
- (a) mixing sintering flux component precursors with the ceramic powder whereby the flux component precursors form a uniform coating on each particle;
- and
- (b) drying and optionally calcining the coated particles.
A sinterable dielectric ceramic composition having a uniform distribution of a zinc borate based sintering flux on the surface of particles of ceramic powder according to the steps of:
- (a) adding a concentrated solution of at least one boron and one zinc flux component precursor to the ceramic powder while maintaining the pH in a predetermined range to prevent the dissolution of ions from the surface of the ceramic powder particles;
- (b) vigorously stirring the mixture below the liquid limit of the powder to uniformly coat the particles with the flux component precursors;
- and
- (c) drying and optionally calcining the coated particles.
Dependencies are inferred from the claim text.