Patent ID: 7384535

Claim:
A method for determining the quantity of both brightener and leveler in a metal plating bath comprising: a) obtaining a plurality of plating bath samples where each bath sample has a known and different quantity of the brightener and the leveler, but where the quantity of each in each bath sample differs from the quantity in the other bath samples; b) for each bath sample, providing a counter electrode, a cleaned working electrode and a reference electrode and carrying out a predetermined sequence of steps comprising: 1. conditioning the working electrode by applying a potential to the working electrode that is anodic followed by a cathodic potential and then an anodic potential and then etching the working electrode with nitric acid; 2. equilibrating the working electrode without energy input to adsorb brightener for a time until the change in energy output with time is minimal and measuring the energy output; 3. plating metal ions on the working electrode with energy input for a time sufficient to measure initial plating energy output; and 4. continuing to plate metal ions for a time sufficient to measure the change in energy output with time; c) for each bath sample, correlating the quantity of brightener with the energy output value obtained in step 2; d) for each bath sample, correlating the quantity of brightener with the initial energy output value obtained in step 3; e) for each bath sample, correlating the ratio of brightener to leveler with the change in energy output with the time value obtained in step 4; f) obtaining a plating bath sample having an unknown quantity of brightener and leveler, placing the electrodes in the bath sample and performing the predetermined sequence of steps; and g) choosing from the correlations in steps c, d and e, a quantity of brightener and the ratio of brightener to leveler which corresponds to the energy output recorded for the bath sample with the unknown quantity of brightener and leveler.