Avx Corporation

David Masheder

Ian Pinwill

Ivan Horacek

Silvie Vilcova

Petr Stojan

Jiri Hurt

Mitchell D Weaver

Jan Petrzilek

Martin Biler

Dirk H Dreissig

Ian H Bishop

A wet electrolytic capacitor that includes a porous anode body containing a dielectric layer, an electrolyte, and a cathode containing a metal substrate on which is disposed a conductive coating is provided. Prior to application of the conductive coating, the metal substrate is blasted with abrasive particles to enhance the ability of the substrate to adhere to the coating. The micro-roughened metal substrate can be treated after blasting so that substantially all of the abrasive particles are removed. This is accomplished by contacting the metal substrate with an extraction solution to remove the particles, and also by selectively controlling the nature of the abrasive particles so that they are dispersible (e.g., soluble) in the solution.

Abrasive blasted cathode of a wet electrolytic capacitor

A wet electrolytic capacitor that contains an anodically oxidized porous anode body, a cathode containing a metal substrate coated with a conductive coating, and a working electrolyte that wets the dielectric on the anode. The conductive coating is formed through anodic electrochemical polymerization ('electro-polymerization') of a microemulsion on the surface of the metal substrate. The microemulsion is a thermodynamically stable, isotropic liquid mixture that contains a precursor monomer, sulfonic acid, nonionic surfactant, and solvent.

Wet capacitor cathode containing a conductive coating formed anodic electrochemical polymerization of a microemulsion

A wet electrolytic capacitor that contains an anodically oxidized porous anode body, a cathode containing a metal substrate coated with a conductive coating, and a working electrolyte that wets the dielectric on the anode. The conductive coating is formed through anodic electrochemical polymerization ('electro-polymerization') of a precursor colloidal suspension on the surface of the substrate. The colloidal suspension includes a precursor monomer, ionic surfactant, and sulfonic acid, which when employed in combination can synergistically improve the degree of surface coverage and overall conductivity of the coating.

Wet capacitor cathode containing a conductive coating formed anodic electrochemical polymerization of a colloidal suspension

A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The powder may have a high specific charge and in turn a relative dense packing configuration. Despite being formed from such a powder, a manganese precursor solution can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a 'film-like' configuration and coats at least a portion of the anode in a substantially uniform manner.

Solid electrolytic capacitor containing an improved manganese oxide electrolyte

A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The present inventors have discovered a technique that is believed to substantially improve the uniformity and consistency of the manganese oxide layer. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a 'film-like' configuration and coats at least a portion of the anode in a substantially uniform manner. This improves the quality of the resulting oxide as well as its surface coverage, and thereby enhances the electrical performance of the capacitor.

Solid electrolytic capacitor for use in high voltage applications

A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The powder has a high specific charge and in turn a relative dense packing configuration. Despite being formed from such a powder, the present inventors have discovered that a manganese precursor solution (e.g., manganese nitrate) can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a 'film-like' configuration and coats at least a portion of the anode in a substantially uniform manner. This improves the quality of the resulting oxide as well as its surface coverage, and thereby enhances the electrical performance of the capacitor.

The invention relates to a method of removing water-insoluble binder from a porous article formed from pressed particulate material, such as tantalum powder. The invention provides a method capable of removing substantially all of the binder from the article for high purity applications, such as capacitor manufacture. The method comprises contacting the article with an aqueous solution of an agent which reacts with said binder to produce a water soluble derivative thereof whereby said binder derivative may be substantially dissolved in said solution. In a particular embodiment, the derivative is produced by hydrolysis of a fatty acid binder.

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Devon, United Kingdom

David Masheder