Capacitive single-mass block full comb electrode sensor for triaxial acceleration and manufacturing method thereof

Abstract

The invention discloses a capacitive single-mass block full comb electrode sensor for triaxial acceleration and a manufacturing method thereof, wherein the acceleration sensor uses single-mass block design, and x, y and z axis all use comb structures on the x y planes as induction acceleration electrodes. An inducing mechanism, which is produced by performing deep reactive ion etching on severelydoped monocrystalline silicon, is composed of a mass block, a spring mechanism and a comb structure. The spring mechanism comprises four groups of U-shaped springs and beam structures, which are symmetrically distributed; two groups of x axis comb mechanisms are symmetrically distributed in the x y plane along the x axis, taking the mass block as the centre; two groups of y axis comb mechanisms are symmetrically distributed in the x y plane along the y axis, taking the mass block as the centre; four groups of z comb mechanisms are symmetrically distributed in the x y plane along the 45 degrees and the 135 degrees lines taking the mass block as the centre. Triaxial acceleration measuring signal outputs do not interfere with each other. The invention achieves triaxial acceleration measurement with a single mass block and a full comb structure electrode.

Description

technical field [0001] The invention relates to a micro-electromechanical capacitive single-mass full-comb electrode three-axis acceleration sensor and a manufacturing method thereof. Background technique [0002] Since the 21st century, Micro-Electro-Mechanical Systems (MEMS) technology has developed rapidly, and MEMS devices based on micro-processing and microelectronics technology have been widely used in human production and life. The development trend of MEMS devices is smaller size, lower energy consumption, lower price, and superior performance. [0003] Micro-electromechanical acceleration sensor is an important micro-electromechanical inertial device, which has been widely used in automobile airbag triggering devices, structural vibration monitoring of machinery and equipment, etc. In recent years, with the continuous miniaturization of products and the significant reduction in cost, Micro-electromechanical acceleration sensors are also gradually used in the field ...

AI Technical Summary

Problems solved by technology

At present, micro-electromechanical capacitive acceleration sensors are mostly single-axis or dual-axis sensing. To realize the three-axis sensing function, the orthogonal assembly of different devices is used or multiple sensors are integrated on one chip, which will make the device bulky and difficult to process. The process is complicated, the cost is increased, and the accuracy of orthogonal assembly is not guaranteed

In the past one or two years, there have been some capacitive acceleration sensors that use a single mass block to sense three-axis acceleration at the same time. Generally, surface micromachining technology is used to measure the acceleration of the x and y axes by using comb electrodes, while the measurement of the z axis acceleration The upper and lower plate design is adopted, which increases the difficulty of the process, and due to the limitations of the surface micro-machining process, it is impossible to obtain a large-volume mass block, so good sensitivity cannot be obtained

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