Analytical study of temperature coefficients of bulk MEMS capacitive accelerometers operating in closed-loop mode

The temperature coefficient of bias (TCB) and temperature coefficient of the scale factor (TCSF) are studied analytically. TCB is caused by a rigid displacement of proof-mass induced by the thermal deformation can be reduced by soft die-attaching, middle-located anchors for movable electrodes, and flexible supporting beam. The temperature dependence of the stiffness of the supporting beam plays no role on TCSF because the inertial force is balanced by the electrostatic force rather than the spring force. As such, TCSF can be reduced obviously as long as the thermal deformation is fully suppressed, such as by soft die attaching, middle-located anchors for immovable electrodes.