A Review of Different Electroplating Anode Materials

The electroplating anode completes the electrical circuit, distributes current to the parts being plated and influences metal distribution at the cathode. In addition, metal from a soluble anode may be converted into ions which enter solution and replenish those discharged at the cathode. There are important plating processes, however, that operate with insoluble anodes where the metal ion concentration in solution is controlled by the addition of soluble metal salts. Auxiliary and bi-polar anodes are used in conjunction with the primary anodes to improve coating thickness uniformity at the cathode. The influence of composition on anode behavior is illustrated by a review of the development of nickel anode materials. A subject of growing importance because of the associated disposal problems is the metal build-up that occurs when anode efficiency exceeds cathode efficiency. Complete automation of anode basket-loading operations may be possible. These and other topics are discussed in this review of different electroplating anode materials.