Performance and reliability of mems gyroscopes at high temperatures

This paper reports the variation in the noise and signal output of a 3-axis MEMS gyroscope that results from physical degradation of the MEMS gyroscope sensor or its packaging caused by long time exposure to wide temperature cycling to high temperatures. Three different 3-axis MEMS gyroscopes were used for this analysis. This study was accomplished by measuring the signal and noise variation at stationary and rotary conditions. Both stationary and rotary tests were conducted at room temperature, and angular velocity was measured in °/s. For the rotary test measurement, the 3-axis MEMS gyroscope was placed on a precise rotary table and rotated at 60°/s (10 rpm), 120°/s (20 rpm) and 240°/s (40 rpm) for five minutes each. These MEMS gyroscopes were then subjected to thermal cycling from -25°C to 125°C for 100 hours (100 cycles).This process was repeated five times for a total of 500 hours of thermal cycling. The same stationary and rotary test measurements were conducted after every 100 hours of thermal cycling exposure to 500 hours. A permanent change in the signal was measured, which is discussed in this paper.