Double H-shaped compression beam silicon micro-resonant pressure sensor chip and preparation method thereof

Abstract

The invention discloses a double H-shaped compression beam silicon micro-resonant pressure sensor chip and a preparation method thereof. The sensor chip comprises a resonant layer and a pressure-bearing membrane. The resonant layer comprises a resonant beam and a balance beam. The four resonant beams form a group of H-shaped beams. The two groups of H-shaped beams are symmetrically arranged. The end parts of the resonant beams are fixed on the balance beams, the two balance beams are connected with the rigid mass block through extension parts of the resonant beams, the mass block is arranged between the adjacent resonant beams, the coupling beam is arranged in the middle of the mass block, the vibration pick-up resistor is arranged in the middle of the coupling beam, and the two mass blocks positioned on the outer side are respectively and fixedly connected with the two movable electrodes. When pressure is applied to the pressure-bearing diaphragm for loading; The resonant beam is pressed to deform, the inherent frequency of the resonant beam is changed, meanwhile, when the resonant beam is excited to vibrate and in a resonant state through the fixed electrode, the vibration pick-up resistors on the coupling beam are in the pressed / pulled state in a circulating mode, the vibration pick-up resistance value is changed based on the piezoresistive effect, and therefore the inherentfrequency of the resonant beam is picked up.

Description

technical field [0001] The invention belongs to the technical field of micro-nano electronic sensors, and in particular relates to a silicon micro-resonant pressure sensor chip with double H-shaped pressure beams and a preparation method thereof. Background technique [0002] The silicon resonant pressure sensor is the pressure sensor with the highest precision at present. It measures the pressure indirectly by detecting the natural frequency of the resonant structure, and it is a quasi-digital output. Its accuracy is mainly affected by the mechanical characteristics of the structure, so it has strong anti-interference ability and stable performance. In addition, silicon resonant pressure sensors also have the advantages of wide frequency band, compact structure, low power consumption, small size, light weight, and mass production, etc., and have always been the focus of research in various countries. Silicon microresonant pressure sensors can be used in airborne air data t...

AI Technical Summary

Problems solved by technology

At present, most resonant pressure sensors have poor quality factors and are unstable, which can easily cause unstable driving force, thus increasing the difficulty of closed-loop control.

In most electrostatically excited resonant sensors, it is easy to cause out-of-plane displacement fluctuations of the movable electrode after loading, which increases the difficulty of closed-loop control; and on a single pressure diaphragm, it is difficult to arrange double H-shaped resonators, and the quality factor is improved. restricted

Images