Micro acceleration sensor of contact type capacitance

Abstract

The invention discloses a micro acceleration sensor of a contact type capacitance. The micro acceleration sensor comprises substrates, a fixed support, substrate electrodes, sensitive films, insulating films, micro beams and an inertial mass block, wherein the upper end and the lower end of the fixed support are respectively provided with the substrates, the inner sides of the two substrates are provided with the substrate electrodes, and the substrate electrodes are covered with the insulating films; the inertial mass block is suspended at the middle part of the fixed support through four micro beams, and the upper side and the lower side of the inertial mass block are provided with the sensitive films which are contacted with the inertial mass block; and the substrate electrodes at the upper end and the lower end of the fixed support are corresponding to the sensitive films at the corresponding ends. In an acceleration measurement process, the inertial mass block always keeps contacting with the substrate electrodes through the sensitive films, the load and the impact force which are larger than those of the micro acceleration sensor of a non-contact type capacitance can be borne, the overload resistant capacity is strong, the acceleration can be measured by the sensor according to the capacitance variation caused by the variation of the contact area between the sensitive films and the insulating films under an overlarge contact load condition, and compared with the micro acceleration sensor of a varied-spacing type capacitance, the linearity is better.

Description

technical field [0001] The invention belongs to the technical field of MEMS sensors, in particular to a contact-type capacitive micro-acceleration sensor. Background technique [0002] The micro-acceleration sensor is an important mechanical quantity sensor and one of the important basic devices of the micro-inertial combined measurement system. With its outstanding advantages such as small size, fast response, high sensitivity, high reliability, and low cost, it has strong market competitiveness and extensive market demand in the military and civilian fields. Since Stanford University in the United States took the lead in the world in 1977 to manufacture an open-loop silicon micro-acceleration sensor using micro-processing technology and commercialized it in the early 1980s, the research on micro-acceleration sensors has made remarkable progress. Various micro-acceleration sensors based on different sensitive mechanisms have been reported, mainly including capacitive, piez...

AI Technical Summary

Problems solved by technology

The dynamic range of this kind of micro-acceleration sensor is limited to a certain extent. Once the two capacitor plates come into contact, the sensor will fail. Usually, in order to improve the sensitivity of the sensor, the spacing between the capacitor plates is often designed to be very small, generally 2-5 microns. , so the capacitive plate is prone to adhesive failure

At the same time, the variable-pitch capacitive micro-acceleration sensor obtains acceleration information by measuring the capacitance change caused by the change in the distance between the capacitive plates, which is a poorly linear response.

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