Capacitance-type triaxial accelerator for micromotor system

Abstract

The invention relates to a method for manufacturing a capacitance-type triaxial accelerator for a micro-electromechanical system (MEMS). The method comprises the following steps: taking a wafer, wherein the wafer is provided with an upper layer, a lower layer and an intermediate layer which is sandwiched between the upper layer and the lower layer, the upper layer and the lower layer are made of semiconductor materials, and the intermediate layer is made of electric insulation materials; arranging at least one electrically conducting component which electrically connecting the upper layer and the lower layer of the wafer; etching a mass block, which is independent of other parts on the lower layer of the wafer, wherein the mass block is provided with a core and four symmetrical side parts; forming a plurality of conductive connection points on the surface of the upper layer of the wafer; etching a suspension component, which is connected with the mass block, on the upper layer of the wafer; and removing the part of the junction formed by the intermediate layer of the wafer sandwiched between the bottom surface of the upper layer of the wafer and the top surface of every lateral part of the mass block, which are connected with the top surfaces of the side parts so as to form a gap.

Description

technical field [0001] The present invention relates to accelerometers, and more particularly to a capacitive three-axis accelerometer for use with micro-electromechanical systems (MEMS). Background technique [0002] Press, U.S. No. 7,361,523 patent discloses a kind of manufacturing method of capacitive three-axis accelerometer (Three-Axis Accelerometer), as this patent Figure 15 and Figure 16 As shown, in addition to the position of the first and second axis accelerometers, a third axis accelerometer is independently installed. Although this kind of accelerometer can detect acceleration on three mutually orthogonal axes, it will make the overall volume larger; moreover, this kind of accelerometer is used to convert the comb-shaped capacitor group of the displacement of each axis. Therefore, the capacitance value measured by the first-axis accelerometer will be transmitted to the second-axis accelerometer, resulting in measurement errors. In addition, the biggest proble...

AI Technical Summary

Problems solved by technology

Although this kind of accelerometer can detect acceleration on three mutually orthogonal axes, it will make the overall volume larger; moreover, this kind of accelerometer is used to convert the comb-shaped capacitor group of the displacement of each axis. The method is combined, so the capacitance value measured by the first-axis accelerometer will be transmitted to the second-axis accelerometer, and measurement errors will occur

In addition, the biggest problem with this type of accelerometer is that due to the use of comb capacitors to convert the displacement, the quality of the mass block for sensing acceleration will be limited within a certain range, so the measurement sensitivity cannot be improved.

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