A novel stress isolation guard ring design for the improvement of three-axis piezoresistive accelerometer

This study designs and implements a stress isolation guard-ring structure to improve the performances of the existing single proof-mass 3-axis piezoresistive accelerometer. Thus, the environment disturbances (temperature variation and force/deflection transmittance) for such packaged 3-axis piezoresistive accelerometer are significantly reduced. Measurements demonstrate the guard-ring design successfully reduce the false signals (induced by temperature variation and force/displacement transmittance) for one order of magnitude. Moreover, the proposed accelerometer still maintains the advantages of existing design, such as single proof-mass for 3-axis acceleration sensing, and better linearity. Sensitivities of present accelerometer range 0.127~1.77mV/G/V and non-linearity<;1.02%VFSS.