Application and comparison of analytic accelerated test-models for lifetime prediction of a novel contacting method

Abstract

Through customers' desire for an individualization of vehicles, new electronics-supported functions are continuously being added. The automobile wiring harness must meet these requests without any further increase of weight and volume. The basic trend towards a modular vehicular design, the continually growing complexity of production and assembly processes, supports the use of flexible flat cables (FFCs) in a hybrid wiring system architecture. For an integral approach, it is also important to develop corresponding alternatives for electrically contacting FFCs with the components. To that end, the process-conditional, one-sided accessibility of FFCs represents a particular challenge. Motivated by these challenges, the Institute FAPS has developed an automated assembly system of FFCs and a new concept for a flexible electric contacting system enabling direct electrical contacting of installed FFCs. To qualify this new contacting method, time and cost consuming climatic tests according to different specifications of the automotive industry have to be carried out. Here, the use of analytic accelerated test-models can predict the failure of electronic contacts subject to the load case. The scope of this approach is the application and comparison of three different accelerated test-methods (Arrhenius, Coffin-Manson and Norris-Landzberg) to the novel contacting method. Firstly climatic tests were performed at different elevated temperatures and from the test data, a lifetime prognosis was derived. Secondly all three models were validated with further climatic testing to determine the possible field application of accelerated test methods.