Patent ID: 6495011
Filing Date: 2002-12-17
Classification: G01N

Abstract:
An apparatus for determining the concentration of additives in a metal plating bath, comprising:a reference electrode, housed in an electrically isolated reference chamber and immersed in a base metal plating solution; a test electrode having a plating surface upon which metal is depositable by electroplating disposed in a measurement chamber containing an electroplating current source electrode, wherein metal plating solutions containing known and unknown concentrations of additives are introduced to, and intermixed with, the base metal plating solution; a capillary tube joining the reference chamber and the mixing chamber in unidirectional fluid flow relationship, having a reference chamber end disposed in the reference chamber and a mixing chamber end disposed in the mixing chamber, whereby base metal plating solution is transferred to the measurement chamber from the reference chamber, and wherein the measurement chamber end of the capillary tube is disposed in close spatial relationship to the plating surface of the test electrode; selectively controllable electroplate driving electronics electrically and operatively coupled between the test electrode and the electroplating current source electrode, whereby metal is selectively deposited onto the test electrode from the mixed metal plating solution in the mixing chamber at a constant or known current density; and electrical potential measuring circuitry electrically and operatively coupled between the test electrode and the reference electrode, whereby electrical potential between the electrodes is measured and recorded.