Resonant type pressure sensor

Abstract

The invention provides a resonant type pressure sensor. The sensor comprises a sensor body, a pressure-sensitive film is formed at the bottom of the sensor body, a first resonator and a second resonator are formed on the pressure-sensitive film, the two resonators have the same intrinsic frequency, sensitivities, to the pressure P acting on the pressure-sensitive film, of the two resonators are equal, the first resonator is located in the center of the pressure-sensitive film, and the second resonator is located on the edge of the pressure-sensitive film. According to the resonant type pressure sensor, the two resonators are adopted, pressure characteristics of the sensor are represented by means of differential frequency output, influences of temperature factors are reduced, and pressure sensitivity and linearity of the sensor are improved. Temperature characteristics of the sensor are represented by means of sum frequency output for sensor temperature compensation, and the use temperature range of the sensor is widened.

Description

technical field [0001] The invention relates to the technical field of MEMS microsensors, in particular to a resonant pressure sensor. Background technique [0002] Resonant pressure sensors are widely used in meteorology, aerospace and other fields due to their advantages of high precision, good stability, semi-digital output, and strong anti-interference. A resonant pressure sensor consists of a usually pressure-sensitive membrane and a resonator. Since the resonator is a movable part, in order to achieve its low-damping vibration working environment and protect it from external dust, humidity, corrosion, etc., the resonator often needs to be sealed in a vacuum environment. In addition, for pressure sensors, vacuum is an ideal pressure reference, which does not change with changes in the external environment (such as temperature, humidity, flow rate, etc.). Therefore, vacuum packaging of the resonator is an inevitable requirement for resonant pressure sensors. [0003] ...

AI Technical Summary

Problems solved by technology

However, this method still has certain problems in the process of manufacturing and packaging resonant pressure sensors: on the one hand, anodic bonding needs to provide high voltage, which is likely to cause electrostatic attraction of movable parts, resulting in device failure; on the other hand, Glass is used for vacuum packaging, and it is often necessary to process lead through holes on the glass for electrical connection with the outside. However, the processing of glass is relatively difficult

There is a deviation between the temperature measured by the external temperature sensor and the temperature of the pressure sensor itself, and the deviation is not fixed, so the compensation accuracy is not high

Integrated temperature sensors can improve the above problems, but need to introduce temperature-sensitive components, which increases the complexity of sensor processing

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