Resistance type micro-mechanical air pressure sensor and preparation method thereof

Abstract

The invention provides a resistance type micro-mechanical air pressure sensor and a preparation method thereof. The resistance type micro-mechanical air pressure sensor comprises: a substrate providedwith a gas cavity and a gas transmission channel, wherein the gas transmission channel communicates the gas cavity with the outside; an electric conducting medium movably arranged in the gas transmission channel; a first sensitive resistor and a second sensitive resistor oppositely arranged in the substrate at an interval, wherein the gas transmission channel is arranged between the first sensitive resistor and the second sensitive resistor, and when the air pressure in the gas cavity is changed, the electric conducting medium can be pushed to move in the gas transmission channel, so that theelectric conducting medium is in contact with the first sensitive resistor and the second sensitive resistor at different positions. According to the invention, a deformed mechanical film is replacedby a movable electric conducting medium, so that the problems of reliability and stability caused by high stress are avoided; and the moving distance of the electric conducting medium is related to the gas volume change, the sensitivity of the sensor can be effectively improved by designing the sizes of the gas cavity and the gas transmission channel, the design flexibility is high, and control is easy.

Description

technical field [0001] The disclosure belongs to the technical field of sensors, and in particular relates to a resistive micromechanical air pressure sensor and a preparation method thereof. Background technique [0002] Barometric pressure sensors are widely used in many fields such as industry, agriculture, home furnishing, and medical treatment. Resistive air pressure sensors generally use the piezoresistive effect to convert stress changes on the air pressure sensitive membrane into resistance changes. Resistive pressure sensors are favored in the consumer product market due to their simple structure and ease of integrated manufacturing. [0003] The main method to improve the sensitivity of resistive air pressure sensor is to increase the local film stress of the sensitive resistor. However, the increased mechanical load brings hidden dangers to the reliability and stability of the sensor. In 1980, Endevco (person's name) and others proposed a double-island membrane...

AI Technical Summary

Problems solved by technology

[0004] Regardless of the structure, due to the nonlinear characteristics of the material under high stress and the plastic deformation beyond the elastic region, there is a limit to the improvement of the sensitivity of the sensor. Device damage

In addition, stress concentration often involves the design of complex mechanical structures, which makes the design of sensors more difficult and requires repeated verification and modification according to design goals

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