A stress-isolated mems inertial sensor

Abstract

The invention discloses an MEMS (Micro Electro Mechanical System) inertial sensor with stress isolation. The MEMS inertial sensor with stress isolation comprises a substrate and a stress isolation layer located above the substrate; the stress isolation layer is fixed on the substrate through a first anchoring point; the portions of the stress isolation layer, located at the two sides of the first anchoring point, are suspended above the substrate; a sensitive structure is arranged on the upper end of the stress isolation layer. According to the MEMS inertial sensor, when the outside temperature and stress are changed, generated strain enters in from the substrate, is delivered to the stress isolation layer through the first anchoring point and is then transported to a sensitive structure to enable the whole sensitive structure to have consistent response to the strain produced for the temperature and stress; through the differential structure of the sensitive structure per se, such common-mode signal can be completely removed, and accordingly signals caused by such outside factors cannot be superimposed to the inertial signal, that is to say, the sensor finally outputs signal change completely caused by the inertia.

Description

technical field [0001] The present invention relates to an inertial measurement device, more particularly, to an inertial measurement device manufactured based on MEMS, such as MEMS accelerometer, gyroscope, oscillator and the like. Background technique [0002] At present, with the development of consumer electronics and wearable devices, the performance of MEMS inertial sensors is increasingly demanding. It is desirable that the output of the sensor be insensitive to changes in external temperature and stress, but only respond to the inertial signal of interest. But the problem is that the MEMS inertial sensor is not independent from the external environment. When the external temperature and stress change, it will inevitably cause corresponding strain. There is the above-mentioned strain transmission path between the external environment and the sensitive structure of the sensor. The strain caused by the influence of external temperature and stress will be transmitted to...

AI Technical Summary

Problems solved by technology

There is the above-mentioned strain transmission path between the external environment and the sensitive structure of the sensor. The strain caused by the influence of external temperature and stress will be transmitted to the sensitive structure of the sensor along the transmission path, resulting in changes in the output signal of the sensor, while the signal processing part of the sensor cannot Distinguish whether the signal change is caused by the inertial signal or the external factors. As a result, the signal change caused by the external factors is unreservedly superimposed on the inertial signal and output together

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