Quantitative accelerated life testing of MEMS accelerometers

Quantitative Accelerated Life Testing (QALT) is a solution for assessing the
reliability of Micro Electro Mechanical Systems (MEMS). A procedure for QALT is shown
in this paper and an attempt to assess the reliability level for a batch of MEMS
accelerometers is reported. The testing plan is application-driven and contains combined
tests: thermal (high temperature) and mechanical stress. Two variants of mechanical stress
are used: vibration (at a fixed frequency) and tilting. Original equipment for testing at tilting
and high temperature is used. Tilting is appropriate as application-driven stress, because the
tilt movement is a natural environment for devices used for automotive and aerospace
applications. Also, tilting is used by MEMS accelerometers for anti-theft systems. The test
results demonstrated the excellent reliability of the studied devices, the failure rate in the
“worst case” being smaller than 10-7h-1.