Hybrid polymer wet electrolytic tantalum capacitors
AssigneeDr. Tantalum, LLC
InventorYuri Freeman
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Abstract
A Hybrid Polymer-Wet Tantalum capacitor is disclosed, as well as a method of making the Hybrid Polymer-Wet Ta capacitor. Additionally, an anode/dielectric/conductive polymer component (unit) and method of making is also disclosed. The capacitors provide the advantages of prior Polymer Tantalum capacitors as well as prior Wet Tantalum capacitors, without the prior disadvantages of each. The inventive capacitors exhibit higher voltage, lower dc leakage and higher charge and energy efficiency in comparison to Polymer Tantalum capacitors; and lower ESR, higher ripple current and higher capacitance stability over temperature and frequency in comparison to Wet Tantalum capacitors.
Claims18
A method of forming a hybrid Polymer-Wet Tantalum capacitor comprising:
- (a) providing a Ta anode formed by compressing and sintering of tantalum powder into a porous tantalum anode and having tantalum wire welded or pressed into the anode;
- (b) anodizing said Ta anode to form a Ta oxide dielectric on the anode's surfaces;
- (c) dipping into or otherwise applying onto said anodized anode a slurry of conductive polymer and permitting it to dry to form a conductive polymer covering the dielectric inside and outside the porous Ta anode;
- (d) providing a liquid electrolyte in contact with said conductive polymer,
- (e) providing a conductive housing to contain the cathode, liquid electrolyte and the Ta anode with the oxide dielectric and conductive polymer;
- and
- (f) forming a positive termination in electrical contact with said tantalum anode and a negative termination in electrical contact with said conductive housing.
A Hybrid Polymer-Wet Tantalum capacitor, comprising:
- (a) a metallic case housing;
- (b) a porous tantalum anode, desirably having no more than 0.1 ppm/uC/g oxygen and no more than 0.001 ppm/uC/g carbon;
- (c) a layer of tantalum oxide on the inner and outer surfaces of said tantalum anode;
- (d) a conductive polymer covering the dielectric layer, desirably formed from by immersing, dipping or otherwise depositing the polymer from a polymer slurry;
- (e) a liquid electrolyte substantially surrounding said conductive polymer;
- (f) metallic housing with cathode;
- (g) a first termination in electrical contact with the tantalum anode through a Ta wire;
- and
- (h) a second termination in electrical contact with the metal housing, cathode and liquid electrolyte, which in turn is in connection with the conductive polymer.
An electrical device comprising an anode/dielectric/conductive polymer component (unit), said component comprising:
- (a) a porous Ta anode having an oxide dielectric coating;
- (b) a conductive polymer formed over said dielectric comprising a dopped conductive polymer, wherein the polymer is selected from dopped intrinsically conductive polymers consisting of poly(3,4-ethyldioxythiophene), polypyrrole, polyaniline, and polythiophene.
Dependencies are inferred from the claim text.