title: Design of a MEMS piezoresistive differential pressure sensor with small thermal hysteresis for air data modules.
abstract: The design, fabrication, and evaluation results of a MEMS piezoresistive differential pressure sensor fabricated by the dry etching process are described in this paper. The proposed sensor is designed to have optimal performances in mid-pressure range from 0 psi to 20 psi suitable for a precision air data module. The piezoresistors with a Wheatstone bridge structure are implanted where the thermal effects are minimized subject to sustainment of the sensitivity. The rectangular-shaped silicon diaphragm is adopted and its dimension is analyzed for improving pressure sensitivity and linearity. The bridge resistors are driven by constant current to compensate temperature effects on sensitivity. The designed differential pressure sensor is fabricated by using MEMS dry etching techniques, and the fabricated sensing element is attached and packaged in a Kovar package in consideration of leakage and temperature hysteresis. The implemented sensors are tested and evaluated as well. The evaluation results show the static RSS (root sum square) accuracy including nonlinearity, non-repeatability, and pressure hysteresis before temperature compensation is about 0.09%, and the total error band which includes the RSS accuracy, the thermal hysteresis, and other thermal effects is about 0.11%, which confirm the validity of the proposed design process.
authors.affiliation: BK21Plus Transformative Training Program for Creative Mechanical and Aerospace Engineers, Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak, Seoul 151-744, South Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Song
authors.affiliation: Microinfinity Co., Ltd., 109 Gwanggyo, Suwon, Gyeonggi 443-270, South Korea.
authors.forename: Jang-Sub
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Agency for Defense Development, Bugyuseong-daero 488 beon-gil, Yuseong, Daejeon 305-152, South Korea.
authors.forename: Jun-Eon
authors.initials: JE
authors.lastname: An
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak, Seoul 151-744, South Korea.
authors.forename: Chan Gook
authors.initials: CG
authors.lastname: Park