Patent ID: 6669833
Filing Date: 2003-12-30
Classification: C25D,H05K,Y10S

Abstract:
A process for electroplating metallic features onto a workpiece comprising a substrate having a top side including surfaces to be electroplated comprising the steps as follows:providing a plating tank with a bottom, side walls, a front wall and a back wall and containing an electroplating bath, providing an anode in the bath connected to a positive voltage, placing a substrate having plating surfaces to be electroplated into the electroplating bath, connecting surfaces to be plated as a first cathode connected to a first negative voltage, providing agitating means for agitating the electrolyte inside the tank, the agitating means including a paddle and suspension means for reciprocating the paddle along a paddle path in the plating bath between the front and back walls parallel to the surfaces to be electroplated in very close proximity thereto, supporting a second cathode including a portion thereof with openings therethrough extending across the surfaces to be electroplated of the substrate and positioned between the plating surfaces and the paddle path, juxtaposing the second cathode with the substrate in close proximity thereto with a narrow space therebetween, and connecting the second cathode to a negative voltage, whereby the portion of the second cathode with openings therethrough maintains the second cathode voltage at a substantially uniform value across the substrate, thereby dominating the electropotential in the bath across the total surface area of the substrate.