摘要:
The present invention concerns the field of solid state capacitors and is directed more particularly to a method for manufacturing solid state electrolytic capacitors formed from porous conductive metal oxide anode bodies and having a cathode layer of conducting polymer, and capacitors thereby formed. There is disclosed a solid state capacitor comprising a porous anode body, a dielectric layer formed on surfaces of the porous anode body and a cathode layer formed on the dielectric layer, characterised by the combination of the anode body being formed from an electrically conducting ceramic material and the cathode layer being formed from an electrically conductive polymer material. The conducting ceramic material may be a metal oxide or nitride.
摘要:
An electrolytic capacitor containing an anode and solid electrolyte overlying the anode is provided. The capacitor may also include a barrier layer that overlies the solid electrolyte to help protect the capacitor from its working environment. More specifically, the barrier layer may include a three-dimensional crosslinked network that provides excellent adhesion to the underlying layers, and also improved barrier properties to moisture. In this manner, the barrier layer can enable the electrolytic capacitor to increase it performance in relatively high humidity and/or high temperature environments.
摘要:
A wet electrolytic capacitor that includes a porous anode body containing a dielectric layer, an electrolyte, and a cathode containing a metal substrate that is abrasive blasted is provided. Abrasive blasting may accomplish a variety of different purposes. For example, it may result in a surface that is substantially uniform and macroscopically smooth, thereby increasing the consistency of conductive coatings formed thereon. While possessing a certain degree of smoothness, the abrasive blasted surface is nevertheless micro-roughened so that it contains a plurality of pits. The pits provide an increased surface area, thereby allowing for increased cathode capacitance for a given size and/or capacitors with a reduced size for a given capacitance. A conductive coating that contains a substituted polythiophene is disposed on the micro-roughened surface. The presence of the pits on the substrate enhances the degree of contact between the conductive coating and metal substrate, thereby resulting in improved mechanical robustness and electrical performance (e.g., reduced equivalent series resistance and leakage current).
摘要:
A solid electrolytic capacitor a solid electrolytic capacitor that includes an anode body, a dielectric overlying the anode body, and a solid electrolyte overlying the dielectric is provided. The capacitor also comprises a conductive polymer coating that overlies the solid electrolyte and includes nanoparticles formed from a poly(3,4-ethylenedioxythiophene) quaternary onium salt.
摘要:
A method for forming an electrolytic capacitor is disclosed. The method includes forming a conductive polymer coating over the dielectric layer by polymerizing a monomer in the presence of an oxidative polymerization catalyst. The conductive polymer coating is formed by dipping the anode in a polymerization solution comprising the monomer, the oxidative polymerization catalyst, and a polar solvent. The polymerization solution has a temperature of less than about 20° C. Cooling the polymerization solution further stabilizes the polymerization solution and prevents premature polymerization of the monomer(s). Thus, the resulting conductive polymer layer can be more intimately positioned with respect to the anode. As a result, the formed capacitor can exhibit better performance.
摘要:
An electrolytic capacitor anode etched with an organic acid prior to anodic oxidation of the anode to create the dielectric layer. Without intending to be limited by theory, it is believed that the organic acid can etch away at least a portion of any oxides on the anode. This provides a relatively uniform surface for the creation of the dielectric, which in turn leads to a dielectric layer having a substantially uniform thickness and homogeneous amorphous structure and thus improved leakage current and stability. The organic acid may also have other residual benefits, such as removing any metallic impurities from the surface of the anode.
摘要:
A method for forming an electrolytic capacitor is disclosed. The method includes forming a conductive polymer coating by polymerizing a monomer in the presence of less than a stoichiometric amount of an oxidative polymerization catalyst. The present inventor has found that the use of less than the stoichiometric amount of the oxidative polymerization catalyst per mole of monomer can slow the polymerization of the monomer, creating oligomers that are shorter in length than if fully polymerized into a polymer. Without wishing to be bound by theory, it is believed that these shorter oligomers provide better penetration into the porous anode. Thus, the resulting conductive polymer layer can be more intimately positioned with respect to the anode. As a result, the formed capacitor can exhibit better performance.
摘要:
A solid electrolytic capacitor that includes an anode body, a dielectric overlying the anode body, a solid electrolyte overlying the dielectric, and a colloidal particle coating that overlies the solid electrolyte. The coating is formed from a colloidal particle dispersion. The particles of the dispersion contain at least two different polymer components—i.e., a conductive polymer and a latex polymer. One benefit of such a coating is that the presence of the latex polymer can help mechanically stabilize the capacitor during encapsulation due to its relatively soft nature. This helps limit delamination of the solid electrolyte and any other damage that may otherwise occur during formation of the capacitor. Furthermore, the latex polymer can also enhance the ability of the particles to be dispersed in an aqueous medium, which is desirable in various applications.
摘要:
A solid electrolytic capacitor that includes an anode body, a dielectric overlying the anode body, a solid electrolyte overlying the dielectric, and a colloidal particle coating that overlies the solid electrolyte. The coating is formed from a colloidal particle dispersion. The particles of the dispersion contain at least two different polymer components—i.e., a conductive polymer and a latex polymer. One benefit of such a coating is that the presence of the latex polymer can help mechanically stabilize the capacitor during encapsulation due to its relatively soft nature. This helps limit delamination of the solid electrolyte and any other damage that may otherwise occur during formation of the capacitor. Furthermore, the latex polymer can also enhance the ability of the particles to be dispersed in an aqueous medium, which is desirable in various applications.
摘要:
A capacitor assembly for use in high voltage and high temperature environments is provided. More particularly, the capacitor assembly includes a solid electrolytic capacitor element containing an anode body, a dielectric overlying the anode, and a solid electrolyte overlying the dielectric. To help facilitate the use of the capacitor assembly in high voltage applications, it is generally desired that the solid electrolyte is formed from a dispersion of preformed conductive polymer particles. In this manner, the electrolyte may remain generally free of high energy radicals (e.g., Fe2+ or Fe3+ ions) that can lead to dielectric degradation, particularly at relatively high voltages (e.g., above about 60 volts). Furthermore, to help protect the stability of the solid electrolyte at high temperatures, the capacitor element is enclosed and hermetically sealed within a housing in the presence of a gaseous atmosphere that contains an inert gas. It is believed that the housing and inert gas atmosphere are capable of limiting the amount of oxygen and moisture supplied to the conductive polymer of the capacitor. In this manner, the solid electrolyte is less likely to undergo a reaction in high temperature environments, thus increasing the thermal stability of the capacitor assembly. In addition to functioning well in both high voltage and high temperature environments, the capacitor assembly of the present invention may also exhibit a high volumetric efficiency.