Low-fire X7R compositions
AssigneeE. I. Du Pont de Nemours and Company
InventorIan Burn
Life of this patent
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Abstract
A composition for forming a densified ceramic dielectric body, the composition consisting essentially of (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide or precursor thereof; (c) 0.4-1.2 wt. % zinc oxide or precursor thereof; (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof; (e) 0.15-0.75 wt. % boron oxide or precursor thereof; and (f)0-0.1 wt. % manganese oxide or precursor thereof. This composition can be used to form the dielectric layers in multilayer electrical devices such as circuits and capacitors.
Claims12
A composition for forming a densified ceramic dielectric body at a temperature below 1150.degree. which dielectric body has a dielectric constant of at least 2500, a temperature coefficient of capacitance that remains within +/-15% of the value at 25.degree. C. over the range of -55.degree. C. to 125.degree. C., a dissipation factor of not more than 2.5% at 25.degree. C. and 1 kHz with 1.0 V applied, and an insulation resistance of at least 1000 ohm.farads at 25.degree. C. and at least 100 ohm.farads at 125.degree. C., the composition consisting essentially of:
- (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns;
- (b) 0.3-1.2 wt. % niobium oxide or precursor thereof;
- (c) 0.4-1.2 wt. % zinc oxide or precursor thereof;
- (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof;
- (e) 0.15-0.75 wt. % boron oxide or precursor thereof;
- and
- (f) 0-0.1 wt. % manganese oxide or precursor thereof.
Dependencies are inferred from the claim text.