Abstract
A study has been made of electrochemical techniques for the measurement of ferric chloride spray etching. Since, in spray etching, the limiting current is very high due to the violent agitation caused by the strong impingment of spray. The solution resistance of ferric chloride etchant was first determined by AC impedance technique to compensate for IR drop. Measurements of cathodic limiting current for the reduction of ferric ion at platinum ring-disk electrode on the impinged surface, were then made at spraying pressures of 25-98kPa and temperatures of 30-60°C. The spray etch rate of copper was proportional to the cathodic limiting current obtained in this study. The results indicate that the use of this technique makes possible the electrochemical monitoring of ferric chloride spray etching.
