The Effect of Oxide Reduction Using Formic Acid Vapours on The Thickness of The Conductive Layer

Abstract

This paper deals with the effect of the formic acid vapours on the thickness and roughness of the conductive layer during oxide reduction process. To fully understand influence of the process is important for the main goal of the whole research, which is creation of high-quality connections by soldering while abandoning from conventional flux in the process. By not using the flux, cleaning and impurities issues can be fully avoided, thus increasing the quality and reducing the price of final products. Conductive layers thickness was analysed by laser confocal microscopy before and after controlled oxidation and afterward oxide reduction process. In the article are discussed several different scenarios that can occur when dealing with differently oxidized substrates, how to handle them, and the effect of differently setup cleaning profiles. Overall suitability of the usage of the formic acid vapours for cleaning of the oxidation of the copper conductive paths is stated.