Micro-inertial sensor with variable pitch capacitor

Abstract

The invention relates to a microinertia sensor of a variable pitch capacitor and a preparation method thereof. The prior product limits the increase in the mass of the sensor vibration generator and the decrease in the polar plate pitch. A sensor mass block is a rectangular silicon chip etched with fence-shaped strips, the two corresponding ends are connected with anchor points by a silicon supporting beam, and the other two corresponding ends are respectively provided with silicon strips with the same quantity and corresponding positions. Driver mass blocks are arranged at the two sides of the sensor mass block, an annular groove is etched in the middle, the two sides are provided with movable driving silicon strips and comb detection silicon strips, and the silicon strips connected with the sensor mass block and the corresponding detection silicon strips form a detection capacitor. The comb strips of the fixed driving silicon strips and the movable driving silicon strips from a driving capacitor. The sensor mass block corresponding to the bottom surface of the glass underlay is provided with interdigital aluminum electrodes, and each fence-shaped strip of the sensor mass block corresponds to each pair of interdigitals in the interdigital aluminum electrodes. The invention has simple technique, and contributes to lowering cost and improving rate of finished products.

Description

technical field [0001] The invention belongs to the technical field of micro-electronic machinery, relates to a micro-inertial sensor, in particular to a high-precision micro-inertial sensor with grid-shaped bar capacitors and small-damping variable-spacing capacitors and a manufacturing method thereof. Background technique [0002] In recent ten years, accelerometers made with micromechanical technology have been developed rapidly. Its main acceleration detection technologies include piezoresistive detection, piezoelectric detection, thermal detection, resonance detection, electromagnetic detection, light detection, tunnel current detection and capacitance detection. In addition, there are accelerometers based on other detection technologies, such as optical accelerometers, electromagnetic accelerometers, and capacitive accelerometers. The development of optical accelerometers is mainly to combine the advantages of light and micromechanics to make sensors with high electro...

AI Technical Summary

Problems solved by technology

For comb-shaped capacitive sensors processed by bulk silicon technology such as deep reactive particle etching (Deep RIE), the aspect ratio of the plate capacitance is generally less than 30:1, which limits the increase in the mass of the sensor vibrator and the Reduced plate spacing

For small-pitch plate capacitors, the pressure film air damping is relatively large, which increases the mechanical noise of the sensor

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