Details

Autor(en) / Beteiligte

• He, Jiangbo
• Xie, Jin
• He, Xiaoping
• Du, Lianming
• Zhou, Wu

Titel

Analytical study and compensation for temperature drifts of a bulk silicon MEMS capacitive accelerometer

Ist Teil von

• Sensors and actuators. A. Physical., 2016-03, Vol.239, p.174-184

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Temperature drifts of a MEMS capacitive accelerometer are studied analytically.•Drifts of bias and scale factor are both affected by thermal deformation.•Drift of scale factor is also affected by stiffness temperature dependence.•Drift of bias is compensated by middle-locating anchors for moving electrodes.•Drift of scale factor is compensated by making its two parts cancel each other. An analytical study and a compensation structure for temperature drifts of bias and scale factor of a bulk silicon MEMS capacitive accelerometer are presented. The analytical model for the temperature drift of bias (TDB) and temperature drift of scale factor (TDSF) is established based on the analysis results of thermal deformation and stiffness temperature dependence. The model shows that TDB is only caused by thermal deformation, while TDSF consists of two parts caused by stiffness temperature dependence and thermal deformation, respectively. The two parts are positive and negative, respectively, but the second part has greater absolute value. First part of TDSF can be reduced by high doping. TDB and second part of TDSF can be both reduced by soft adhesive die attaching or increasing substrate thickness. In silicon structure, TDB can be reduced by middle-locating anchors for moving electrodes in sensitive direction or decreasing the stiffness asymmetry of springs, while second part of TDSF can be reduced by middle-locating anchors for fixed electrodes in sensitive direction. By middle-locating anchors both for moving electrodes and fixed electrodes, a temperature compensation structure is designed to reduce TDB and second part of TDSF. Consequently, TDSF is reduced by making the two parts of TDSF cancel each other. Experimental results show that TDB is suppressed from 1.85mg/°C to 0.52mg/°C, while TDSF from −162.7ppm/°C to −50.8ppm/°C.