Reliability evaluation of a MEMS scanner

Abstract

Previously, the realization and closed loop control of a MEMS scanner integrating position sensors made with piezoresistive sensors was presented. It consisted of a silicon compliant membrane with integrated position sensors, on which a mirror and a magnet were assembled. This device was mounted on a PCB containing coils for electromagnetic actuation. In this work, the reliability of such system was evaluated through thermal and mechanical analysis. The objective of thermal analysis was to evaluate the lifetime of the MEMS scanner and is consisting of temperature cycling (-40 degrees C to 100 degrees C) and accelerated electrical endurance (100 degrees C with power supplied to all electrical components). The objective of mechanical analysis was to assess the resistance of the system to mechanical stress and is consisting of mechanical shock and vibration. A high speed camera has been used to observe the behavior of the MEMS scanner. The use of shock stopper to improve the mechanical resistance has been evaluated and had demonstrated a resistance increase from 250g to 900g. The minimum shock resistance required for the system is 500g for transportation and 1000g for portative devices.