An Investigation on the Effect of Commercial Volatile Corrosion Inhibitors on Circuit Board Test Patterns Under Simulated Aggressive Conditions

In recent years electronic equipment that was originally designed to operate in controlled environments has developed rust on the exterior of the supporting structure, while in transit, storage, in use in harsh environments. This typically occurs in highly contaminated environments, where pollution and poor environmental control allows the generation of pollutants at a fast rate. The rust formation can create several technical problems but perhaps the most immediate is the concern of the costumers. Recently, it has been suggested that, in order to protect the external appearance of electronic equipment, VCIs (Volatile Corrosion Inhibitors) could be used while shipping and storing electronic equipment. Despite the extensive use of VCIs in many applications, very little has been done to study their effects (positive or negative) on electronic devices. In the present study, test circuit board test patterns were used to investigate the change in leakage current (between the tracks in the board) associated with the adsorption of different commercially available VCIs. The samples were subjected to different conditions simulating the environment to which equipment could be exposed during transit or storage. The first set of experiments was performed at RH values from 50 to 88% and temperatures between 25 and 75C. Further studies include more aggressive environments simulating those existing in locations to which the equipment has to be shipped. Additional information also includes surface analysis of some pure metals and alloys subjected to the same kind of VCIs.