Patent attributes
A semiconductor pressure sensor for measuring an external pressure exerted on the sensor, comprises a membrane, and a bridge comprising a first and a second resistor pair, arranged on a first resp. second side portion of the membrane. The first resistor pair comprises a first and a second resistor (R1, R2) comprising elongated piezo-resistive strips connected in series, and located closely together, such that R1 and R2 have substantially the same temperature. The sensor has a reduced sensitivity to: a temperature gradient over the membrane, and optionally also a non-uniform stress gradient caused by packaging and a inhomogeneous disturbing electric field perpendicular to the sensor. The piezo-resistive strips of the first and second resistor may be oriented in orthogonal directions of maximum piezo-resistive coefficients. A second bridge may be added outside the membrane, for compensating for package pressure.
