Capacitive micro-accelerometer sensitive structure

Abstract

The invention belongs to the technical field of inertial measurement, and specially discloses a capacitive micro-accelerometer composition sensitive structure. The capacitive micro-accelerometer composition sensitive structure comprises an upper pole plate, a middle pendulous reed microstructure and a lower pole plate; any two of the upper pole plate, the middle pendulous reed microstructure and the lower pole plate are connected with through a bonding layer; the middle pendulous reed microstructure comprises a frame, an elastic thinned beam and a mass block, and the elastic thinned beam and the mass block are surrounded by the frame; the upper and lower surfaces of the elastic thinned beam are provided with concave grooves which are staggered in position, the bottom of each concave groove aligns to the neutral plane of the elastic thinned beam; the interior of each concave groove is provided with an electrode leading wire, and the electrode leading wire comprises an upper concave groove electrode and a lower concave groove electrode; the upper concave groove electrode is communicated with the upper surface electrode of the mass block, and the lower concave groove electrode is communicated with the lower surface electrode of the mass block; the upper surface and the lower surface of the tail end of the mass block are respectively provided with a backstop boss used for limiting the displacement of the mass block under the action of strong vibration or huge impact. According to the invention, influence of stress and temperature deformation on the sensitive structure is prevented in a maximum limit, error suppression is achieved, and a higher performance is obtained.

Description

technical field [0001] The invention belongs to the technical field of inertial measurement, and in particular relates to a capacitive micro accelerometer sensitive structure. Background technique [0002] MEMS accelerometer is an inertial sensor device used to measure acceleration based on microelectronics and micromechanical technology. It has the advantages of small volume, weight, power consumption, high integration, resistance to harsh environments, and low cost. It is mainly used in aerospace , automobile industry, drilling and detection and other military and civilian fields. [0003] Micro-electromechanical accelerometers include resonant beam micro-accelerometers, piezoresistive micro-accelerometers, capacitive micro-accelerometers, etc. Among them, the resonant beam micro-accelerometer has high requirements on the manufacturing process, and the resonance detection circuit is relatively complicated; the piezoresistive micro-accelerometer has low precision and is se...

AI Technical Summary

Problems solved by technology

[0006] When the elastically thinned beam is bent by external force or subjected to inconsistent temperature deformation, the upper (lower) surface of the beam is elongated by tension, and the lower (upper) surface of the beam is shortened by pressure. Correspondingly, the electrode leads on the upper (lower) surface of the beam are subjected to tension and compression Deformation will also occur, which will generate error output and deteriorate the performance of the micro-accelerometer; the elastically thinned beam and the mass block form a cantilever structure. When subjected to harsh mechanical conditions such as strong external vibrations or large impacts, the mass block will drive the beam to produce greater bending Deformation, when the deformation exceeds the bearing limit of the beam, it is easy to cause structural damage

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