Failure analysis of automotive electronics and microsystems

This paper presents the results of experiments and combined numerical calculations for various kinds of automotive sensors and different microcomponents and microsystems for 'high tech' applications. With growing miniaturization, the 'local' properties of interconnected materials exert a greater influence on the reliability of microcomponents and microsystems than in any macroscopic component. The research team of the author has applied such techniques as acoustic microscopy, laser scanning microscopy, thermography, various kinds of laser field measuring techniques, X-ray stress analysis and the micro-DAC method, combined with FEA field simulation and reliability concepts. Special attention has been given to analysing the thermal fatigue and creep behaviour of solder regions (e.g. solder bumps and micro-solder interconnects) in the near chip regions of microsystem packages and housings. Advanced packaging strategies in automotive applications (e.g. the micromechatronic packaging approach, area array packaging, CSP, etc.) are in the focus of this research. The micro-moire´and micro-DAC techniques are described, using a laser and electron beams for the detection of local micro-deformation fields as well. Different automotive sensors, HF devices and other microcomponents and microsystems have been investigated and evaluated with respect to reliability and lifetime estimation. Crack avoidance strategies have been developed and employed successfully in various applications. Besides the classic concepts of FEA and also stochastic FEM, tools are applied in detail and combined with probabilistic fracture concepts to study the influence of scattering material parameters and of the geometric configuration on reliability estimations as well. The aim is to show that an adequate combination of advanced experimental and simulation approaches leads to reliable results for failure assessment and lifetime predictions of 'high tech' microsystems, e.g. MEMS, in automotive applications.

Keywords:

• Sensor
• Micro-COMPONENTS
• Micro-SYSTEMS
• Thermal
• Automotive
• Electronics
• Temperature