Thermal Energy Analysis for Sulfuric Acid Dilution Step in Copper Electroplating Process

Abstract

In the pre-treatment step of copper electroplating process, sulfuric acid diluted to 5-12% by volume solution is used as a solvent to remove contaminants from the product prior to the electroplating process. Because of heat of solution, the solution temperature increases. However, electroplating process begins only when the diluted sulfuric solution reaches the settemperature. At present, there is no tool to predict this set time at a specific temperature resulting in difficulty in operation. The developed mathematical model accounts for two modes of heat transfer; conduction and convection at the surface of the mixing bath. The results show that the developed model could well predict the setting time with an average error of less than 7.57 minutes and predict the maximum temperature with an average errorless than 6.04 oF.