Working electrode design for electrochemical processing of electronic components

摘要

An electroplating apparatus including a plating tank for containing a plating electrolyte. A counter electrode, e.g., anode, is present in a first portion of the plating tank. A cathode system is present in a second portion of the plating tank. The cathode system includes a working electrode and a thief electrode. The thief electrode is present between the working electrode and the counter electrode. The thief electrode includes an exterior face that is in contact with the plating electrolyte that is offset from the plating surface of the working electrode. In one embodiment, the thief electrode overlaps a portion of the working electrode about the perimeter of the working electrode. In one embodiment, a method is provided of using the aforementioned electroplating apparatus that provides increased uniformity in the plating thickness.

主权项

1. An electroplating apparatus comprising:
a plating tank containing a plating electrolyte; an anode present in a first portion of the plating tank; and a cathode system present in a second portion of the plating tank, the cathode system comprising:
a working electrode comprising a supported portion and an exposed portion, wherein the exposed portion defines a plating surface;a thief electrode that is separated from the working electrode,
wherein the thief electrode is present between the working electrode of the cathode system and the anode, andwherein an exterior face of the thief electrode is offset from the plating surface of the working electrode; anda holder configured to support the working electrode, the holder comprising a lip portion comprising:
a first surface extending over and directly contacting the supported portion of the working electrode, anda second surface opposing the first surface and directly contacting the thief electrode,wherein the thief electrode comprises a rim portion extending beyond an edge of the lip portion of the holder and overlapping the plating surface of the working electrode about a perimeter of the working electrode.