Design and experiment of a laterally driven micromachined resonant pressure sensor for barometers

Abstract

A novel resonant pressure sensor based on electromagnetically driven and sensed H-type lateral beam resonators is described and FEA simulation is carried out on the analysis of the sensitivity, linearity and temperature drift of the pressure sensor. The resonant elements consist of four clamped-clamped boron diffused silicon beams (30 μm in thickness) organized along the diagonal direction suspended on a silicon square diaphragm, the differential output of two of which provides the sensor reading. The beams and the diaphragm are fabricated by bulk micromachining techniques in one wafer, which is then bonded to another supporting silicon wafer in vacuum, leaving the resonant beams exposed to the pressure media. The cleaved sensor die is mounted to the metal package by fixing the die only at a corner through stacks of small silicon dies with epoxy. The proposed pressure sensor has advantages such as low cost, ease of fabrication and high performance, making it suitable for barometers.