Monitoring of the PH using ISFET sensors in electroplating processes

Abstract

It is well known that electroplating with metals has achieved quite a significant importance and has become a lucrative area. The present paper looks at the electroplating processes as a part of the metallurgical industry that are carried out with diverse aims. The quality and characteristics of the metal deposit depend on the electrochemical conditions imposed, such as pH. During an industrial electroplating process, when an undesirable change is detected first in the metal coating attained, is a common occurrence that a complete change of the plating bath is carried out. Due to this, the application of analytical systems to enable in situ precise monitoring of any compositional changes of the bath during the electroplating process, is an unquestionable need to be carefully satisfied. The design of such systems should allow close control of the concentrations of specific components during the process, constituting thus a desirable aim entailing both, financial and time savings. In the present work, the construction of an analytical system based on the coupling of a continuou sampling system with pH ISFET sensors is described. Comparative studies between a glass electrode and the proposed analytical system in copper, silver and nickel electroplating baths are carried out.