Pressure sensor with variable sense gap

Abstract

The disclosure relates to a pressure sensor with a variable sense gap. A sensor device includes a substrate having a port extending through it and a membrane including a first electrode spanning across the port. The port exposes the membrane to a pressure stimulus from an external environment. A second electrode is spaced apart from the first electrode by a gap having a first width. A control circuit applies an actuation voltage to move the second electrode closer to the first electrode and change the gap to a second width that is less than the first width. When the gap is set to the second width, the pressure sensor exhibits a greater sensitivity than when the gap is set to the first width. The membrane with the first electrode is movable in response to the pressure stimulus and the pressure stimulus is sensed as movement of the first electrode relative to the second electrode while the actuation voltage is applied.

Description

technical field [0001] The present invention generally relates to microelectromechanical system (MEMS) sensor packaging. More specifically, the present invention relates to a MEMS pressure sensor having a variable sensing gap for changing the sensitivity of the pressure sensor. Background technique [0002] Microelectromechanical systems (MEMS) devices with embedded mechanical components include, for example, pressure sensors, accelerometers, gyroscopes, microphones, digital mirror displays, microfluidic devices, and the like. MEMS devices are used in a variety of products such as automotive airbag systems, in-vehicle control applications, navigation, display systems, inkjet cartridges, and more. Capacitive sensing MEMS device designs are highly desirable for operation in miniaturized devices due to their low temperature sensitivity, small size and suitability for low cost mass production. MEMS pressure sensors typically use a pressure cavity and a diaphragm element called...

AI Technical Summary

Problems solved by technology

The integration of MEMS pressure sensors with other types of sensors, such as accelerometers and gyroscopes, poses particular challenges in achieving the requisite enhanced sensitivity of such pressure sensors, among others.

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