Mems microgravity sensor chip with quasi-zero stiffness characteristics based on electrostatic preloading

Abstract

The MEMS microgravity sensor chip with quasi-zero stiffness characteristics based on electrostatic preloading includes a single crystal silicon substrate, a silicon dioxide insulating layer is grown on the single crystal silicon substrate, and a single crystal silicon structural layer is bonded on the silicon dioxide insulating layer. A MEMS acceleration sensor chip is made in the monocrystalline silicon structure layer; the MEMS acceleration sensor chip includes a chip frame, and a set of electrode anchor points are respectively distributed at its four corners, and the array A and B electrode plates connected between each set of electrode anchor points form a capacitor. For the drive unit, the end of the electrode plate is connected to the electrode anchor point, the upper and lower side B electrode plates are connected to the middle arm, and the middle arm is connected to the mass block through the spring. Except for the electrode anchor point and the chip frame, the monocrystalline silicon substrate under the rest and The insulating layer of silicon dioxide is corroded; the axial displacement loading of the spring is carried out by electrostatic drive, and the mass block obtains a working area with quasi-zero stiffness in the vertical direction without reducing the vertical stiffness of the spring, which can be used in microgravity Acceleration detection has the characteristics of simple structure and so on.

Description

technical field [0001] The invention relates to the technical field of acceleration sensors, in particular to a MEMS microgravity sensor chip with quasi-zero stiffness characteristics based on electrostatic preloading. Background technique [0002] The earth's gravity field contains a wealth of physical information. As human production activities gradually go underground, the measurement environment and indicators of gravity acceleration become more stringent. People's demand for high-resolution and high-precision microgravity acceleration detection technology is increasing. eager. With the iterative development of manufacturing technology, micro-electromechanical system (MEMS) acceleration sensors with small size, low energy consumption and high precision are increasingly replacing traditional acceleration sensors and becoming the mainstream. Whether using optical, capacitive or resonant measurement methods, the spring-mass system with high sensitivity is the core structur...

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Problems solved by technology

However, the feature size of the reverse spring structure is very small, which requires high manufacturing technology and has the disadvantage of narrow bandwidth.

[0005] To sum up, since the sensitivity of the spring-mass system in the vertical direction is inversely proportional to its stiffness in this direction, if the vertical stiffness of the spring is simply reduced in order to increase its sensitivity, the bearing capacity of the system will also decrease , that is, the mass of the connected mass decreases and the acceleration it can withstand is also very small, so the sensitivity direction stiffness of the main structure of the existing in-plane motion MEMS acceleration sensor cannot be made very low, and the sensitivity of the mass block is therefore limited, and the low g The resolution of value detection still needs to be improved

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