Improving reliability of thick film initiators for automotive applications based on FE-analyses

Finite element method (FEM) has been proved as a useful tool to design thick film initiators for automotive safety unit applications as well as a method of rapid prototyping of such devices. Besides, it contributes to improve the reliability of the system since potential reasons of failure will be highlighted and as a result suitable remedies can be applied. Parameters like the thermal characteristics of the pyrotechnics, pore inclusions in the explosive, physical properties of the involved thick film materials as well as diffusion effects occurring at the termination ends of the initiator element have to be taken into account during the design process with regard to reliability aspects. Practical ignition tests have been conducted with thick film initiator elements and an explosive composed of Sb/KMnO4 in the order to prove the efficiency of numerical simulation for the design process.