vnement - date ICM conference 2015 Haithem Skima FEMTO-ST Institute December 21 st, 2015 Accelerated Lifetime Tests and Failure Analysis of an Electro-thermally Actuated MEMS valve FEMTO-ST Institute, Besanon France Haithem Skima, Kamal Medjaher, Noureddine Zerhouni, Christophe Varnier, Eugen Dedu and Julien Bourgeois 2/ 18 Outline H. Skima, K. Medjaher, N. Zerhouni, C. Varnier, E. Dedu, J. Bourgeois, ICM Conference, December 20-23, 2015 oIoI ntroduction oMoM otivation oAoA ccelerated lifetime tests oRoR esults oCoC onclusion and future work 3/ 18 o Micro-Electro-Mechanical Systems: MEMS A MEMS is a micro-system that integrates mechanical components using electricity as source of energy in order to perform measurement functions and / or operating in structure having micrometric dimensions. OthersMOEMSRF MEMS Micro actuators Micro sensors Bio MEMS Categories of MEMS o Applications Automotive Aerospace BiomedicalOptical FluidicCommunication technologies Introduction Introduction Motivation Accelerated lifetime tests Results Conclusion 4/ 18 Introduction o Mechanical, electrical and material based failures mechanisms o Failure mechanisms related to manufacturing or to utilization Influence factors: temperature, humidity, vibration, noise, dust, shocks, overcharges [H. R. Shea 2007, M. McMahon et al. 2012, J. Ruan et al. 2009, R. Mller-Fiedler et al. 2002] [M. MATMAT 2010] Introduction Motivation Accelerated lifetime tests Results Conclusion 5/ 18 Introduction Stiction in electro-thermal actuator [M. Dardalhon 2003] Micro-actuator finger fracture [ B. Charlot 2001] Contamination in a comb-drive [Tanner et al ] Stiction of the finger on the substrate [Tanner et al. 2000] o Examples of failure mechanisms in MEMS Introduction Motivation Accelerated lifetime tests Results Conclusion 6/ 18 Prognostics & Health Management: PHM Motivation MEMS Reliability issues Loss of performance Faults (Non achieved functions) Risk of accidents Reliability Availability Security cost Introduction Motivation Accelerated lifetime tests Results Conclusion Accelerated lifetime tests performing Health assessment and state estimation Time to failure prediction Decision making Degradation model definition MEMS 7/ 18 Accelerated lifetime tests o Definition Accelerated lifetime test is an aging of a product that induces normal failures in a short amount of time by applying stress levels much higher than normal ones (stress, strain, temperatures, voltage, vibration rate, pressure, etc.). The main interest is to observe the evolution over time to predict the life span. Reliability results can then be obtained by analyzing the products response to such tests. o Difficulty in MEMS failure analysis Structures of interest are not exposed for direct observation Structures that provide the stimulus for motion or actuation are obscured from view Introduction Motivation Accelerated lifetime tests Results Conclusion 8/ 18 Accelerated lifetime tests o System description Electrothermally actuated MEMS valve designed by DunAn Microstaq company to control flow rates or pressure with high precision at ultra-fast time response (