Application of uncertainty analysis to experimental reliability of sensors by thermal shock test

In this paper an example is discussed concerning the possibility of using metrological concepts, like uncertainty of measurement, systematic effects, statistical distribution of measurements, in order to improve the interpretation capability of a specific failure mechanism in a controlled field of influences. This approach has been also used to set an interpolation in a certain range of condition when the temperature of tests is changed. The case study refers to the degradation assessment of ultrasonic sensors for distance measurement, which is ascribed to the quality decay of solder joints due to cracks or remarkable shrink holes. The components are subjected to ALT cyclic thermal stresses. The results of tests allowed to gaining information about the validation of a model of fault, useful to design accelerated tests at higher temperatures.