Finite-element model-based fault diagnosis, a case study of a ceramic pressure sensor structure

Finite-element (FE) analysis is an efficient aid in the design optimisation of modern electronic devices. Simulation tools have dramatically reduced the product design cycle. The model validated with actual prototypes can also be used for other purposes such as failure analysis, fatigue prediction, reliability studies, etc. In this paper we present a case study of application of FE model in fault localisation in ceramic pressure sensor structures. The sensing elements are thick-film resistors acting as strain gauges, which translate the strain into an electrical signal. In the design phase, FE analysis was used to analyse the sensitivity of the thick-film resistors to the applied pressure. The same model was used for non-destructive fault diagnosis and troubleshooting of the prototype series. Selected examples illustrate the approach. FE model can also be used in the production test process. Since simulations are rather time consuming, quick fault localisation can be performed by a fault dictionary while in-depth diagnosis is performed by FE analysis. 2007 Elsevier Ltd. All rights reserved.