Raymond W Ribitch

US Patent:

53605276, Nov 1, 1994

Filed:

Apr 30, 1993

Appl. No.:

8/055859

Inventors:

Raymond W. Ribitch - Mount Pleasant MI

Assignee:

Hitachi Magnetics Corp. - Endmore MI

International Classification:

C25D 1708

US Classification:

204297R

Abstract:

A rack for electroplating contains a plurality of windows for receiving an article to be electroplated. The rack is rotatably mounted to a frame connected to a cathode of a power supply. A portion of the border of each window is made of a conductive article which is connected to the cathode via the frame. Mesh screens flank each side of the windows, retaining the article within its borders. A series of non-conductive drive gears rotate the rack, moving the article to different contact points along the window. During electroplating, the movement of the article insures that the entire surface of the article is plated, thereby avoiding rack marks. The window's conductive elements divert metal ions away from the edge of the article, thereby offsetting the natural buildup of ions along the edge and increasing surface uniformity. The ratio of the thickness of the window's conductive elements to the thickness of the article are adjusted to produce an edge to center ratio of less than one, equal to one, or more than one.