Electrochemical drilling system and process for improving electrical porosity of etched anode foil

摘要

A process for creating porous anode foil for use in an electrolytic capacitor of an implantable cardioverter defibrillator is provided. The process includes electrochemical drilling a plurality of etched metal foils in sequence one after the other in a bath containing electrochemical drilling (ECD) solution initially having a pH of less than 5. Alternatively, an etched foil sheet may be passed through the bath in a substantially continuous manner such that a portion of said etched foil sheet is in contact with the ECD solution is electrochemically drilled to generate pores. Electrochemical drilling is achieved when a current is passed to the foil or portion of the foil sheet in solution, ECD replenishment solution having a pH of less than about 5 is added from a feed reservoir to the bath at such a rate so as to maintain a pH in the ECD solution in the bath of less than about 5, and ECD solution in the bath is removed to a waste reservoir at the substantially the same rate as the addition of the ECD replenishment solution to the bath.

主权项

1. A system for creating a porous anode foil, comprising:
an electrochemical bath containing an electrochemical drilling (ECD) solution initially comprising 10 to 5000 PPM of a surface passivator, and about 0.1% by weight of an acid, wherein the ECD solution has a pH within a range of 0.5 to 3, the bath configured to receive an etched foil sheet in a substantially continuous manner such that a portion of said etched foil sheet is in contact with the ECD solution in the bath; a charge source connected to the bath to cause an electrochemical reaction in the bath; a feed reservoir fluidly connected to the electrochemical bath, the feed reservoir containing an ECD replenishment solution comprising 10 to 5000 PPM of the surface passivator, and about 0.1% by weight of the acid, wherein the ECD replenishment solution has a pH within a range of 0.5 to 3; a waste reservoir fluidly connected to the electrochemical bath for receiving ECD solution removed from the bath; and a pump for adding the ECD replenishment solution to the bath from the feed reservoir so as to maintain the pH of the ECD solution within a range of 0.5 to 3.