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15 Reliability Practices for

Design and Application

of Space-Based MEMS

Robert Osiander and M. Ann Garrison Darrin

CONTENTS

15.1 Introduction to Reliability Practices for MEMS....................................... 327
15.2 Statistically Derived Quality Conformance and
Reliability Specifications........................................................................... 328
15.3 Physics of Failure (POF) Approach.......................................................... 329
15.4 MEMS Failure Mechanisms...................................................................... 331
15.4.1 Material Incompatibilities ............................................................ 331
15.4.2 Stiction.......................................................................................... 332
15.4.3 Creep............................................................................................. 333
15.4.4 Fatigue .......................................................................................... 333
15.4.4.1 Fracture ........................................................................ 334
15.5 Environmental Factors and Device Reliability......................................... 334
15.5.1 Combinations of Environmentally Induced Stresses ................... 335
15.5.2 Thermal Effects ............................................................................ 341
15.5.3 Shock and Vibration..................................................................... 342
15.5.4 Humidity ....................................................................................... 342
15.5.5 Radiation....................................................................................... 342
15.5.6 Electrical Stresses......................................................................... 343
15.6 Conclusion ................................................................................................. 344
References............................................................................................................. 344

15.1 INTRODUCTION TO RELIABILITY PRACTICES FOR MEMS

Reliability is the ability of a system or component to perform its required functions
under stated conditions for a specified period of time. 1
This chapter begins with the classification of failures for spacecraft compon-
ents. They are generally categorized as:

(1) Failures caused by the space environment, such as damage to circuits by
radiation
(2) Failures due to the inadequacy of some aspect of the design
(3) Failures due to the quality of the spacecraft or of parts used in the design or
(4) A predetermined set of ‘‘other’’ failures, which include operational errors 2

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© 2006 by Taylor & Francis Group, LLC