Electrochemical surface analysis using deoxygenated gel electrolyte

Abstract

Electrochemical surface analysis using a deoxygenated gel electrolyte provides advantages over a liquid electrolyte in processes such as sequential electrochemical reduction analysis. In sequential electrochemical reduction analysis, a solderable portion of an electronic component or circuit board to be tested is placed in contact with a deoxygenated gel electrolyte such as a borate buffer solution having a gelling agent. The gel electrolyte prevents capillary attraction up or along a lead of the component so that the power source cathode lead does not contact the electrolyte and electrochemical analysis can be localized to the area of interest, such as the portion of the component lead to be soldered. Interfering effects of atmospheric oxygen are minimized for deaerated gel electrolytes because convection mixing is practically absent and diffusion is generally a very slow process in a gel. For a gel electrolyte saturated with inert gas and including an oxygen scavenger, brief exposure to oxygen as test specimens are changed does not affect the electrochemical analysis. In some cases, it is be possible to perform electrochemical analysis in ambient atmosphere rather than in an inert gas as generally required by the prior art.