Failure dependent progression of contact resistance in thermal-shock testing of spring-clip contacts

Through ever changing terms and regulations on fuel consumption and emissions, weight becomes the number one concern of car manufacturers. Meeting those new regulations and the customer's desire for more options and variations is only possible without adding more weight by changing the wiring harnesses' technology. One solution to face this problem can be found by the application of flexible flat cables (FFCs) instead of common round cable wire systems. For a holistic approach, it is important not only to establish automated ways of cable installation, but also methods of automatically contacting components. Therefore, a new direct contacting method was developed at the Institute for Factory Automation and Production Systems (FAPS). The innovative contacting method enables to contact an automatically mounted one side accessible FFC with kinematic systems of industrial robots in an automated way. However, before new technologies can be applied to serial production, car manufacturers demand standardized climatic tests. In this paper, a correlation was discovered between the progression of contact resistance and failure mechanisms during thermal shock testing. Furthermore, an influence of different peak temperatures and materials was identified and the results were verified via SEM micrographs.