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US 11,387,047 B2Granted
Solid electrolytic capacitor with improved performance at high temperatures and voltages
AssigneeKYOCERA AVX Components Corporation
InventorsJan Petrzilek, Miloslav Uher, Tomas Hofirek
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Abstract
A capacitor assembly that is capable of exhibiting good electrical properties even under a variety of conditions is provided. More particularly, the capacitor contains a capacitor element that includes a porous anode body that contains a valve metal compound, a dielectric that overlies the anode body and includes an oxide of the valve metal compound, a solid electrolyte that overlies the dielectric, wherein the solid electrolyte includes at least one conductive polymer layer that contains a sulfonyl ion, and an organofunctional silane that is bonded to the oxide of the dielectric and is capable of bonding to the sulfonyl ion of the conductive polymer layer.
Claims21
A capacitor assembly comprising a capacitor element, the capacitor element comprising;
- a sintered porous anode body that contains a valve metal compound;
- a dielectric that overlies the anode body and includes an oxide of the valve metal compound;
- a solid electrolyte that overlies the dielectric, wherein the solid electrolyte includes at least one conductive polymer layer that contains a sulfonyl ion and wherein the conductive polymer layer contains an extrinsically conductive polymer and a sulfonyl counterion or an intrinsically conductive polymer;
- an external polymer coating that overlies the solid electrolyte;
- and
- an organofunctional silane that is covalently bonded to the oxide of the dielectric and is capable of bonding to the sulfonyl ion, wherein the organofunctional silane is a diaminofunctional silane having the following general formula (III):
- wherein,
- R1, R2, and R3 are independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, or hydroxyalkyl;
- R4 and R5 are independently hydrogen, alkyl, independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, hydroxyalkyl, or alternatively N, R4, and R5 together with one or more additional atoms form a ring structure;
- and
- Z1 and Z2 are independently an organic group;
- wherein the organofunctional silane forms at least a first layer that contains a single silane compound;
- wherein after being subjected to a hot atmosphere having a temperature of about 80° C. or more and a rated voltage for 90 seconds and a time of about 100 hours or more, the capacitor assembly exhibits a leakage current of from about 0.1 microamps to about 10 microamps as determined at the rated voltage;
- and
- wherein a ratio of a capacitance of the capacitor assembly after being exposed to the hot atmosphere for about 500 hours to a capacitance value of the capacitor assembly when initially exposed to the hot atmosphere is from about 0.7 to 1.
12 more elements
A method for forming a capacitor assembly, the method comprising:
- anodically oxidizing a sintered porous anode body to form a dielectric that includes an oxide of a valve metal compound;
- applying a solution to the anode that includes a single organofunctional silane compound, wherein the organofunctional silane is a diaminofunctional silane having the following general formula (III):
- wherein,
- R1, R2, and R3 are independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, or hydroxyalkyl;
- R4 and R5 are independently hydrogen, alkyl, independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, hydroxyalkyl, or alternatively N, R4, and R5 together with one or more additional atoms form a ring structure;
- and
- Z1 and Z2 are independently an organic group;
- applying a dispersion that contains conductive polymer particles and a sulfonyl counterion to form a conductive polymer layer;
- covalently bonding the organofunctional silane compound to the oxide of the dielectric, wherein the organofunctional silane compound is capable of bonding to the sulfonyl counterion;
- and
- applying an external polymer coating that overlies the solid electrolyte;
- wherein the conductive polymer layer contains an extrinsically conductive polymer and a sulfonyl counterion or wherein the conductive polymer layer contains an intrinsically conductive polymer having repeating units of the following formula:
- wherein,
- R is (CH2)a—O—(CH2)b;
- a is from 0 to 10;
- b is from 1 to 18;
- Z is an anion;
- X is a cation;
- wherein after being subjected to a hot atmosphere having a temperature of about 80° C. or more and a rated voltage for 90 seconds and a time of about 100 hours or more, the capacitor assembly exhibits a leakage current of from about 0.1 microamps to about 10 microamps as determined at the rated voltage;
- and
- wherein a ratio of a capacitance of the capacitor assembly after being exposed to the hot atmosphere for about 500 hours to a capacitance value of the capacitor assembly when initially exposed to the hot atmosphere is from about 0.7 to 1.
18 more elements
Dependencies are inferred from the claim text.