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: Non-aqueous electrolytic solutions suitable for anodizing valve metal derivative anodes, methods of anodizing using non-aqueous electrolytic solutions, and capacitors prepared with non-aqueous electrolytic solutions. The non-aqueous electrolytic solution comprises glycerine and at least one soluble salt formed by the neutralization of at least one non-halogen-containing organic or inorganic acid anion with at least one alkali metal, ammonium, or protonated amine cation; wherein the acid anion is derived from an acid having a pKa lower than phosphoric acid.

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: Non-aqueous electrolytic solutions suitable for anodizing valve metal derivative anodes, methods of anodizing using non-aqueous electrolytic solutions, and capacitors prepared with non-aqueous electrolytic solutions. The non-aqueous electrolytic solution comprises glycerine and at least one soluble salt formed by the neutralization of at least one non-halogen-containing organic or inorganic acid anion with at least one alkali metal, ammonium, or protonated amine cation; wherein the acid anion is derived from an acid having a pKa lower than phosphoric acid.

Abstract: A method of preparing a capacitor having at least one porous element comprising applying to the element a masking material with an ink jet printer head. Preferably the masking material is a liquid resin such as an acrylic, a polyurethane, a silicone, or a polyimide.

Abstract: A method of anodizing valve metals with a borate polyester solution formed by the combining 2-methyl-1,3-propane diol and boric acid and heating to about 130 to about 160° C. The heating drives off water produced by esterification. A substrate is immersed in the borate polyester electrolyte solution at a temperature of about 25° C. to about 85° C. and an anodizing voltage is applied.

Abstract: A process for isolating flaw sites in the dielectric of solid electrolytic capacitor comprising immersing a conductive polymer impregnated capacitor in an electrolyte solution, and then alternately subjecting the conductive polymer impregnated capacitor to a high voltage and a low voltage; wherein the high voltage is between about 10 volts and 50 volts, and the low voltage is between about 0 volts and the voltage corresponding to 90% of the anodization voltage for pellets anodized at less than 20 volts, or the voltage at which the current drops to 50% of the peak voltage current for pellets anodized at voltages greater than or equal to 20 volts. The period of time at or above the anodization voltage is relatively short to prevent damaging the dielectric film.

Abstract: An electrolyte comprising water, an organic solvent selected from the group consisting of a polyethylene glycol, a polyethylene glycol monomethyl ether and mixtures thereof, and a sufficient amount of alkali metal salt of a weak organic acid, so that the electrolyte has a resistivity below about 250 ohm-cm/80° C. A method for differential anodizing porous valve metal body comprising the steps of: anodizing the bodies in a first electrolyte where the cathode surface is placed within an inch of but not in contact with the anode bodies, rinsing the bodies in deionized water, and re-anodizing the bodies in a second electrolyte, where the first electrolyte comprises water, an organic solvent selected from the group consisting of a polyethylene glycol, a polyethylene glycol monomethyl ether and mixtures thereof, and a sufficient amount of alkali metal salt of a weak organic acid so that the first electrolyte has a resistivity below about 250 ohm-cm/80° C.

Abstract: Capacitor elements made with a solid polymeric electrolyte show reduced leakage current when reformed at about 60-85% of formation voltage during the impregnation phase between successive layers of polymeric electrolyte.