RESEARCH ON QUANTIFYING CORROSION EFFECT ON ELECTRICAL CONTACT RESISTANCE FOR AUTOMOTIVE APPLICATIONS

Preventing electrical contact resistance caused by corrosion is one of the challenging problems while improving durability of automotive electronic systems. Due to the variability of the environment that affects corrosion and the increase in uncontrolled mechanism of corrosion related resistance, it is difficult to predict the change in electrical resistances. Exposure of the electrical contacts in different atmospheric conditions cannot be avoided, which requires a development of a method to quantify the corrosion effects in the electrical contact behaviors. In this paper, we propose a method to quantify corrosion effect on electrical contact resistance which can be used to derive automotive wiring design parameters such as number of terminals, corrosion preventing shrink tube, soldering and the type of clamping. The suggested method uses the database of various wires under various corrosion conditions. Contact resistance at the ten major contacts considered to be prone to corrosion is measured for the cars driven in different environmental conditions, driven duration and the total distance traveled by a car. Contacts are selected on the basis of contact location, wire types (varying in diameters) and the number of wires clamped in a single connector. Also a contribution of galvanic corrosion in the increase in contact resistance at the contact is analyzed considering the direction of current flow. Designing wiring while controlling electrical contact resistance under corrosion can be possible using proposed method which leads to improvement of durability characteristics.