High-g-value and high-sensitivity MEMS acceleration sensor and preparation method thereof

Abstract

The invention discloses a high-g-value and high-sensitivity MEMS acceleration sensor, and belongs to an MEMS acceleration sensor. Thehigh-g-value and high-sensitivity MEMS acceleration sensor comprises a substrate, a device layer and a cover plate, the substrate and the cover plate are respectively bonded with the device layer from two sides of the device layer, the device layer comprises an outer frame, a mass block and four support beams, the mass block and the four supporting beams are located in the outer frame. By adopting the design scheme that four T-shaped structure supporting beams are connected with the mass block, the x, y and z axial stop structures are innovatively designed, and the sensor adopts a cover plate-device layer-substrate sandwich packaging structure, so that batch wafer-level packaging is easy to realize; the supporting beams adopts a double-E-shaped structural design, so that the output sensitivity of the device is greatly improved; pressing film damping between the device layer and the cover plate and between the device layer and the substrate is optimized, the overall dynamic performance of the sensor is improved, and the service life of the device is prolonged.

Description

technical field [0001] The invention belongs to a MEMS acceleration sensor, in particular to a high-g value, high-sensitivity MEMS acceleration sensor and a preparation method thereof. Background technique [0002] High-g acceleration sensors based on MEMS technology are widely used in harsh environments such as acceleration signal measurement, vibration measurement, explosion, and shock in the automotive industry, military and aerospace fields, which requires the acceleration sensor to have excellent shock resistance. A high frequency response range requires effective overload protection and near-critical damping design at the chip level. [0003] For the acceleration sensor with cantilever beam structure, its first-order natural frequency is low, the frequency response range is narrow, and the lateral sensitivity is relatively large. Although the acceleration sensor with four-sided multi-beam structure design has the lowest lateral sensitivity, in addition, most existing p...

AI Technical Summary

Problems solved by technology

[0003] For the acceleration sensor with cantilever beam structure, its first-order natural frequency is low, the frequency response range is narrow, and the lateral sensitivity is relatively large. Although the acceleration sensor with four-sided multi-beam structure design has the lowest lateral sensitivity, in addition, most existing piezoresistive acceleration sensors The shock response curve of the sensor has burr interference, which is caused by the vibration interference of the natural frequency of the support beam. A small number of sensors are vulnerable. The reason is that the vibration amplitude is too large due to the low damping of the sensor, which causes the device layer to break and damage.

Images