Measurement of TOC in Copper(II) Sulfate Solution and Nickel Sulfamate Solution Using TOC-VCSH

Introduction

Copper sulfate solution and nickel sulfamate solution are generally used as plating solutions for the copper and nickel plating processes in the manufacture of printed circuit boards. Organic additives are added to these plating solutions, but since the additive itself affects plating quality, it is important to control its concentration to ensure the quality of the printed circuit board. In this respect, the TOC analyzer can be used to manage the concentration of the organic additive. As the salt concentrations in the copper sulfate solution and nickel sulfamate solution can amount to several percent or more, this salt can be expected to interfere with direct analysis with the combustion type TOC analyzer. Accordingly, dilution of the solution is required to prevent this interference. When conducting analysis of plating solution using an combustion type TOC analyzer, the solution must be diluted by a factor of more than 25 in consideration of the salt concentration. However, since the Shimadzu combustion type TOC analyzer incorporates an automatic dilution capability, TOC analysis can be conducted by utilizing this function to dilute high-salt concentration samples automatically in the TOC analyzer. Examples of the analysis of copper sulfate and nickel sulfamate simulated plating solutions using the Shimadzu TOC-V_CSH Oxidative Combustion Type TOC Analyzer is presented here.

January 23, 2007 GMT