A capacitor for use in relatively high voltage environments is provided. During formation, anodization may be carried out in a manner so that the dielectric layer possesses a relatively thick portion that overlies an external surface of the anode and a relatively thin portion that overlies an interior surface of the anode. In addition to employing a dielectric layer with a differential thickness, the solid electrolyte is also formed from the combination of pre-polymerized conductive polymer particles and a hydroxy-functional nonionic polymer.

Solid Electrolytic Capacitor with Enhanced Wet-to-Dry Capacitance

An improved process for forming a capacitor, and improved capacitor formed thereby is described. The process includes: providing an anode comprising a dielectric thereon; applying a first layer of an intrinsically conducting polymer on the dielectric to form a capacitor precursor; applying at least one subsequent layer of an intrinsically conducting polymer on the first layer from a dispersion; and treating the capacitor precursor at a temperature of at least 50°C no more than 200°C at a relative humidity of at least 25 % up to 100%, or fusing the layered structure by swelling the layered structure with a liquid and at least partially removing the liquid.

Solid electrolytic capacitor and improved method for manufacturing a solid electrolytic capacitor

A capacitor whose electrical properties can be stable under a variety of different conditions is provided. The solid electrolyte of the capacitor is formed from a combination of an in situ polymerized conductive polymer and a hydroxy-functional nonionic polymer. One benefit of such an in situ polymerized conductive polymer is that it does not require the use of polymeric counterions (e.g., polystyrenesulfonic anion) to compensate for charge, as with conventional particle dispersions, which tend to result in ionic polarization and instable electrical properties, particularly at the low temperatures noted above. Further, it is believed that hydroxy-functional nonionic polymers can improve the degree of contact between the polymer and the surface of the internal dielectric, which unexpectedly increases the capacitance performance and reduces ESR.

Temperature stable solid electrolytic capacitor

A solid electrolytic capacitor that comprises a sintered porous anode, a dielectric layer that overlies the anode body, and a solid electrolyte overlying the dielectric layer is provided. The anode is formed from a finely divided powder (e.g., nodular or angular) having a relatively high specific charge. Despite the use of such high specific charge powders, high voltages can be achieved through a combination of features relating to the formation of the anode and solid electrolyte. For example, relatively high press densities and sintering temperatures may be employed to achieve “sinter necks” between adjacent agglomerated particles that are relatively large in size, which render the dielectric layer in the vicinity of the neck less susceptible to failure at high forming voltages.

Solid electrolytic capacitor with improved performance at high voltages

A capacitor assembly that is capable of performing under extreme conditions, such as at high temperatures and/or high voltages, is provided. The ability to perform at high temperature is achieved in part by enclosing and hermetically sealing the capacitor element within a housing in the presence of a gaseous atmosphere that contains an inert gas, thereby limiting the amount of oxygen and moisture supplied to the solid electrolyte of the capacitor element. Furthermore, the present inventors have also discovered that the ability to perform at high voltages can be achieved through a unique and controlled combination of features relating to the formation of the anode, dielectric, and solid electrolyte. For example, the solid electrolyte is formed from a combination of a conductive polymer and a hydroxy-functional nonionic polymer.

Solid electrolytic capacitor for use in extreme conditions

A process for preparing a solid electrolytic capacitor comprising application of a non-ionic polyol prior to application of a conducting polymer layer.

Process for producing electrolytic capacitors and capacitors made thereby

A method for forming a capacitor, a capacitor formed thereby and an improved composition for a conductive coating are described. The method includes providing an anode, forming a dielectric on the anode and forming a cathode layer over the dielectric by applying a monoamine, a weak acid and a conductive polymer.

Hong Zhang

Papers

Solid electrolytic capacitor and improved method for manufacturing a solid electrolytic capacitor

Process for producing electrolytic capacitors and capacitors made thereby

Process to improve coverage and electrical performance of solid electrolytic capacitors