Metal capacitance microaccelerator

Abstract

A micro-accelerometer of metal capacity type is prepared as arranging top electrode plate and to stop block on top base body and bottom electrode plate and bottom stop block on bottom base body, undertaking function of intermediate electrode plate by mass block being distributed with through holes and being set between top and bottom base bodies, setting I / O lead pin on bottom base body, connecting top and bottom base bodies to each other by support column and using said support column to transmit electric signal between top base body and I / O lead pin.

Description

technical field [0001] The invention relates to a micro-accelerometer in the technical field of micro-electromechanical systems, in particular to a metal capacitance micro-accelerometer. Background technique [0002] Accelerometer is an important sensor widely used in many fields such as industry, military, aviation, and daily life. The use of micromachining technology to achieve miniaturization is conducive to reducing volume and power consumption, improving the degree of integration and intelligence, facilitating mass production and reducing production costs, which is the current development trend of accelerometers. According to the working principle, micro accelerometers can be divided into capacitive, piezoresistive, piezoelectric, resonant, optical fiber, etc., among which the capacitive type has the advantages of high sensitivity and small temperature drift, so it is developing rapidly. The working principle of the capacitive micro-accelerometer is: the moving plate o...

AI Technical Summary

Problems solved by technology

[0003] After searching the existing technical documents, it was found that the Chinese Patent Publication No. CN1959417A and the patent titled "Micromechanical Capacitive Acceleration Sensor and Its Manufacturing Method" mentioned a capacitive micro accelerometer. Plate, lower plate, mass block and intermediate plate on the mass block, etc., have the following disadvantages: Except for the metal film used for the plate, the rest of the materials are silicon-based materials, but silicon-based materials are brittle, easy to break, Disadvantages of poor impact resistance; the number of supporting beams is small, and there are only 2 supporting beams on the four corners of the mass block. - Lower resonant frequency of the beam system

In addition, the micro-accelerometer constitutes the middle plate by covering the surface of the mass block of silicon-based material with a metal film, which not only easily generates parasitic capacitance between different materials, but also affects the bonding rate between the two due to the effect of temperature stress. As movable parts, the plate and the mass block will vibrate or even resonate under the action of impact load, which is prone to further peeling off and leads to an increase in parasitic capacitance, and may even eventually cause the middle plate to fall off completely

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