Abstract: A solid electrolytic capacitor comprising a foil coated with a dielectric oxide film, wherein the coated foil has slit or cut edges, and the slit or cut edges have been reformed by anodizing the foil in an aqueous oxalic acid electrolyte, then forming the foil in an aqueous citrate electrolyte, then depolarizing the foil, and then forming the foil in an aqueous phosphate electrolyte.

Abstract: A solid electrolytic capacitor comprising a foil coated with a dielectric oxide film, wherein the coated foil has slit or cut edges, and the slit or cut edges have been reformed by forming the foil in an aqueous citrate electrolyte, then depolarizing the foil, and then forming the foil in an aqueous phosphate electrolyte wherein the foil is not anodized in an aqueous acid electrolyte prior to forming the foil in an aqueous citrate electrolyte.

Abstract: Edges of a slit and cut to length foil having a dielectric oxide film on at least one surface are edge formed by comprising anodizing the foil in an aqueous oxalic acid electrolyte, further edge a forming the foil in an aqueous citrate electrolyte, preferably dibasic ammonium citrate electrolyte, depolarizing the foil, and then edge forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate.

Abstract: Edges of a slit and cut to length foil having a dielectric oxide film on at least one surface are edge formed by edge forming the foil in an aqueous citrate electrolyte, preferably an aqueous ammonium citrate electrolyte, depolarizing the foil, and then edge forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate electrolyte. Using this formation process, a foil with excellent hydration resistance and capacitance is produced.

Abstract: Disclosed is a process for the continuous anodizing of aluminum foil for use in aluminum electrolytic capacitors. Specifically, etched anode foil is anodized to relatively low voltage in a two-step reel-to-reel process. The process is particularly useful for anodizing highly-etched aluminum foil for use in surface mount aluminum capacitors containing conductive polymer cathode material. The process is economical and provides high foil quality. Specifically, the process for anodizing aluminum foil comprises anodizing the foil in a first electrolyte a solution, passing the foil through an oven, anodizing the foil in a second anodizing solution wherein the first electrolyte solution and second electrolyte solution each comprise about 5 wt % to about 50 wt % glycerine, about 0.01 wt % to about 0.2 wt % ammonium phosphate, and de-ionized water, and wherein the foil is anodized in the first electrolyte solution for at least 3.

Abstract: A process for edge forming a slit and cut-to-length foil having a dielectric oxide film on its face comprising anodizing the foil in an aqueous oxalic acid electrolyte, further forming the foil in an aqueous citrate electrolyte, preferably dibasic ammonium citrate electrolyte, depolarizing the foil, and then forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate.

Abstract: A process for edge forming a slit and cut-to-length foil having a dielectric oxide film on its face comprising forming the foil in an aqueous citrate electrolyte, preferably an aqueous ammonium citrate electrolyte, depolarizing the foil, and forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate electrolyte. Using this formation process, a foil with excellent hydration resistance and capacitance is produced.

Abstract: Aluminum surface mount capacitors containing one or more anode foil coupons are initially anodized in an aqueous phosphate solution in order to produce an anodic oxide film having extreme resistance to hydration and attack by corrosive anions for the purpose of producing surface mount capacitors at high yield and of high stability.

Abstract: A method of anodizing an aluminum substrate comprising heating the substrate to a first temperature of 200° C. to about 380° C.; suspending the substrate into a first electrolyte and applying a first anodizing current to the first electrolyte; rinsing the substrate; heating the substrate to a second temperature of 200° C. to about 380° C.; and suspending the substrate into a second electrolyte and applying a second anodizing current to the second electrolyte, wherein the first electrolyte and second electrolyte each comprise an aqueous solution of at least one salt of alpha-hydroxy acid.

Abstract: Aluminum surface mount capacitors containing one or more anode foil coupons are initially anodized in an aqueous phosphate solution in order to produce an anodic oxide film having extreme resistance to hydration and attack by corrosive anions for the purpose of producing surface mount capacitors at high yield and of high stability.

Abstract: A method of anodizing an aluminum substrate comprising heating the substrate to a first temperature of 200° C. to about 380° C.; suspending the substrate into a first electrolyte and applying a first anodizing current to the first electrolyte; rinsing the substrate; heating the substrate to a second temperature of 200° C. to about 380° C.; and suspending the substrate into a second electrolyte and applying a second anodizing current to the second electrolyte, wherein the first electrolyte and second electrolyte each comprise an aqueous solution of at least one salt of alpha-hydroxy acid.

Abstract: An electrochemical cell for etching a metal workpiece such as an aluminum foil, a method for etching the foil using the electrochemical cell, and foil thus produced is provided. The cell includes an etch tank having an etch electrolyte disposed therein and containing at least a first and a second compartment each containing (i)an etch electrolyte, (ii) a cathode plate, and (iii) an ion exchange membrane separator portion having an ion exchange polymeric material effective to substantially retard or prevent reduction of the oxidizing agent or agents present in the etch electrolyte, the first and second compartments being arranged in the etch tank with the ion exchange membrane separator portions in facing relationship one to the other; and a metal workpiece such as an aluminum foil anode present in the etch tank and disposed between each said first and second compartments.

Abstract: An electrochemical cell for etching a metal workpiece such as an aluminum foil, a method for etching the foil using the electrochemical cell, and foil thus produced is provided. The cell includes an etch tank having an etch electrolyte disposed therein and containing at least a first and a second compartment each containing (i)an etch electrolyte, (ii) a cathode plate, and (iii) an ion exchange membrane separator portion comprising an ion exchange polymeric material effective to substantially retard or prevent reduction of the oxidizing agent or agents present in the etch electrolyte, the first and second compartments being arranged in the etch tank with the ion exchange membrane separator portions in facing relationship one to the other; and a metal workpiece such asan aluminum foil anode present in the etch tank and disposed between each said first and second compartments.