Micro-mechanical acceleration sensitive structure for suppressing crosstalk in high-precision single-axis optical micro-accelerometer and its manufacturing method

Abstract

The invention discloses a micro mechanical acceleration sensitive structure for inhibiting crosstalk in a high-precision single-shaft optical micro-accelerometer, and a manufacturing method thereof. The micro mechanical acceleration sensitive structure comprises a bulk silicon sensitive mass block, four symmetrically distributed crab-leg-shaped cantilever beams, a silicon substrate connected with the cantilever beams, and a reflective film plated on the surface of the sensitive mass block. It can be ensured that the gravity center of the sensitive mass block is disposed at a center plane of the cantilever beams through a specially designed microprocessing process, the direction of the sensitive shaft of the single-shaft optical micro-accelerometer is vertical to the center plane, and thus off-axis crosstalk is fundamentally inhibited through adjustment of the position of the gravity center; and the micro mechanical acceleration sensitive structure cooperates with the diffraction grating based optical micro-accelerometer so that the off-axis crosstalk can be effectively inhibited under the condition that the sensitivity of high-acceleration measurement is ensured, the applied surface microprocessing technology can be compatible with an IC technology, and batch manufacture is realized.

Description

technical field [0001] The invention belongs to the technical field of optical micro-acceleration sensors, and relates to a micro-mechanical acceleration sensitive structure for suppressing crosstalk in a high-precision single-axis optical micro-accelerometer and a manufacturing method thereof. Background technique [0002] An accelerometer is a sensor that measures the basic physical quantity of acceleration. Its basic measurement principle is based on Newton's second theorem. The accelerometer usually includes a mechanical acceleration sensitive system and a displacement measurement system. The external acceleration causes the mass block in the mechanical acceleration sensitive system to produce a The displacement that has a definite relationship with the magnitude of the input acceleration, the displacement measurement system obtains the magnitude of the input acceleration by measuring the displacement. The performance of the accelerometer is determined by both systems si...

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