DC Etching of aluminum electrolytic capacitor foil
AssigneeSprague Electric Company
InventorMulk R. Arora
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Abstract
Aluminum electrolytic capacitor foil is etched by passing the foil through an electrolyte bath containing 2.5 moles/liter of sodium chloride and 0.08 to 0.48 moles/liter of boric acid or 0.05 to 0.07 moles/liter of a citrate ion source under the influence of direct current and at a temperature of 90.degree. to 95.degree. C. The foil thus etched has a central metallic core which results in improved mechanical properties.
Claims5
A process for etching aluminum electrolytic capacitor foil comprising passing the foil through an electrolyte bath containing substantially 2.5 moles/liter of sodium chloride and a compound selected from the group consisting of boric acid and citrate ion source, wherein the concentration of said compound is 0.08 up to 0.48 moles/liter of boric acid and 0.05 to 0.07 moles/liter of citrate ion source under the influence of direct current at a temperature of 90.degree. to 95.degree. C. and a charge passed of 500 to 540 coulombs to provide an etched foil with a central metallic core.
Dependencies are inferred from the claim text.