Overload-resistant pressure sensors in the nominal range of 10 mbar (1 kPa)

AbstractDifferential pressure sensors with silicon diaphragms provide a nominal measuring range of 10 mbar (1 kPa) at a measurement uncertainty of ≤2⋅10−3. An additional external overload protection mechanism is required to achieve an overload reserve up to 160 bar (16 MPa). To integrate the overload protection at the wafer level, a micromechanical overload protection is needed. Such a micromechanical overload protection for differential pressure sensors can be produced from heat-treated glass. The functional principle limits the diaphragm deflection. Here, we demonstrate an overload capability reaching 50 bar (5 MPa) for a silicon diaphragm with a nominal measuring range of 10 mbar and a diaphragm thickness of 30 μm