A six-axis integrated micro-acceleration sensor and its manufacturing method

Abstract

The invention discloses a six-axis integrated micro-acceleration sensor and a manufacturing method thereof, comprising upper and lower cover plates and a sensing chip connected together by bonding. The sensing chip includes four beams drawn from the diagonal of the fixed outer frame and connected to the "island" in the middle, so that the "island" in the middle of the outer frame, the beams on the diagonal of the outer frame, and the outer frame form a whole— A fixed frame, each inertial sensing unit is composed of an inertial mass block, a structural support beam, and a sensitive micro-beam, each inertial mass block is trapezoidal, and the middle part of the upper bottom has a structural support beam extending to the lower bottom ; On both sides of the structural support beam, there are sensitive micro-beams connecting the upper bottom edge of the trapezoidal inertial mass block with the "island" in the middle of the fixed frame. Due to the small structure of the sensitive microbeam, the main stress will be concentrated when the sensitive chip is loaded, and it is easy to form a simple stress state of direct tension and direct compression, which is very conducive to decoupling between axes. The invention has a simple and compact structure and is easy to process.

Description

technical field [0001] The invention relates to the field of silicon micro-accelerometers, in particular to a piezoresistive six-axis high-range micro-accelerometer and a manufacturing method thereof. Background technique [0002] An acceleration sensor refers to a sensor that can measure the acceleration of an object's motion. Sensitivity, linearity, inter-axis coupling, response speed, response frequency bandwidth, stability, etc. are its main performance indicators. The micro-accelerometer is a kind of acceleration sensor and is an important part of the newly developed micro-electromechanical system (MEMS). With the development of the semiconductor industry, especially the development of MEMS technology, more and more high-performance, low-energy Micro-acceleration sensors with low power consumption and low price are gradually applied to all walks of life, constantly changing the way people live and work. As a special inertial measurement device, the high-range accelera...

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Problems solved by technology

Patent CN101692099 reports a piezoresistive dual-axis accelerometer with zero drift compensation. Although it solves the problem of piezoresistive temperature drift and has a high natural frequency, it is a combination of two uniaxial sensitive elements. And it can only measure the movement in two directions, and there are 4 movements in the six degrees of freedom in the object space that cannot be measured, which cannot meet the requirements of all-round measurement and precise control for research on penetrating weapons.

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