Evaluating and monitoring nucleation and growth in copper foil

The electrodeposition of copper foil for use in electronic materials applications is a complex and demanding process. The specific aspects of producing and controlling the structure-property-performance requirements of the foil are important because of the stringent demands placed on their use in printed circuit boards and similar products. In this paper, a brief review of the electrodeposition process for raw copper foil is presented. Since electrolyte additives play such a significant role in the copper-depositionprocess, the effects of two essential additives, chloride ion and an organic (e.g., glue or gelatine), on the foil are described. Also, the influence of other operating parameters on the initial nucleation, growth, and subsequent electrocrystallization are discussed. Selected characterization methods, such as polarization and scanning electron micrography techniques, are described as a means of monitoring the process, but universally accepted methods of evaluating and controlling the additives and foil quality during electrolysis are still being sought.