A new mixed organic layer for enhanced corrosion protection of electric contacts

A large collaboration among different laboratories involving electrical engineering, surface chemistry and organic chemistry has been set up in a European program (5FP, project: 10622). It has allowed to develop a new type of organic layer on metallic surfaces with outstanding results in the field of protection against corrosion. Application to low level electrical contacts is very promising. Several types of highly fluorinated molecules have been specially synthesised and selected in order to build up a compact protective layer. Various techniques were used to characterise these films; their bonding to the substrate, their cohesion, their surface energies were analysed and the results were correlated to their corrosion properties. This led to the elaboration of a new type of layer with outstanding features. We report here the main results with emphasis on the results of the atmospheric corrosion test performed both on gold plated coupons and connector terminals. In this latter case the test comprises contact resistance measurements at various stages. We show how a suitable formulation allows to obtain low contact resistance values and low corrosion.