Solid electrolytic capacitor containing conductive polymer particles
AssigneeAVX Corporation
InventorsJan Petrzilek, Martin Biler
Life of this patent
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Abstract
A solid electrolytic capacitor that contains an anode body, dielectric overlying the anode body, adhesion coating overlying the dielectric, and solid electrolyte overlying the adhesion coating. The solid electrolyte contains an inner conductive polymer layer and outer conductive polymer layer, at least one of which is formed from a plurality of pre-polymerized conductive polymer particles. Furthermore, the adhesion coating contains a discontinuous precoat layer containing a plurality of discrete nanoprojections of a manganese oxide (e.g., manganese dioxide).
Claims20
A solid electrolytic capacitor comprising:
- an anode body;
- a dielectric that overlies the anode body;
- an adhesion coating that overlies the dielectric, wherein the adhesion coating contains a discontinuous precoat layer that contains a plurality of discrete nanoprojections of a manganese dioxide;
- a solid electrolyte that overlies the adhesive coating and includes an inner conductive polymer layer and an outer conductive polymer layer, at least one of which is formed from a dispersion of pre-polymerized particles;
- and
- an external polymer coating overlying the solid electrolyte, wherein the external polymer coating contains a plurality of pre-polymerized conductive polymer particles, and wherein a ratio of an average size of the pre-polymerized conductive polymer particles, particles employed in the external polymer coating to an average size of the particles employed in any dispersion of the solid electrolyte is from about 1.5 to about 30,
- wherein one or more discrete manganese dioxide nanoprojections are embedded in the solid electrolyte;
- and
- wherein the manganese dioxide nanoprojections have an average size of from about 5 nanometers to about 500 nanometers.
A method for forming a solid electrolytic capacitor, the method comprising:
- contacting an anode that contains an anode body and a dielectric with a solution that contains a manganese oxide precursor;
- pyrolytically converting the precursor to form a discontinuous pre-coat layer containing a plurality of discrete nanoprojections of a manganese dioxide;
- chemically polymerizing a monomer to form an inner conductive polymer layer of a solid electrolyte that is in contact with the dielectric and nanoprojections;
- applying a dispersion of pre-polymerized conductive polymer particles to form an outer layer of the solid electrolyte that overlies the inner layer, wherein at least one of the inner conductive polymer layer or the outer layer is formed from a dispersion of pre-polymerized particles;
- and
- applying an external polymer coating overlying the solid electrolyte, wherein the external polymer coating contains a plurality of pre-polymerized conductive polymer particles, and wherein a ratio of an average size of the pre-polymerized conductive polymer particles employed in the external polymer coating to an average size of the particles employed in any dispersion of the solid electrolyte is from about 1.5 to about 30;
- wherein one or more discrete manganese dioxide nanoprojections are embedded in the solid electrolyte;
- and
- wherein the manganese dioxide nanoprojections have an average size of from about 5 nanometers to about 500 nanometers.
Dependencies are inferred from the claim text.