Full-bridge double-push-pull-flow z-axis film gyroscope and processing method thereof

Abstract

The invention discloses a full-bridge double push-pull flow z-axis film gyroscope and a processing method thereof, the z-axis film gyroscope comprises a sensitive layer and a cover plate, the upper surface of the sensitive layer is provided with two pairs of heaters, two pairs of thermistors and an isolation resistor; the electrifying mode of the heater is periodic push-pull electrifying; and a groove is etched on the cover plate and is hermetically connected with the upper surface of the sensitive layer. According to the invention, full-bridge and double-push-pull type heat flow is adopted, four bridge arms participate in work, the sensitivity is four times that of a single arm, the sensitivity is the highest one, and the power consumption is low; and the extraction circuit is an equal-armed bridge, the relation nonlinearity between the bridge arm resistance change of the equal-armed bridge and the bridge output unbalanced voltage is minimum, and the linearity of the gyroscope is good.

Description

technical field [0001] The invention relates to the technical field of detecting the angular velocity and attitude parameters of a moving body by using a heat flow sensitive body deflected by Coriolis force, in particular to a full-bridge double push-pull flow z-axis film gyroscope and a processing method thereof, belonging to the field of inertial measurement. Background technique [0002] The miniature inertial sensor made by MEMS (Micro-Electro-Mechanical-System) technology has many advantages such as mass production, low cost, small size, and low power consumption. It is an ideal product for medium and low-precision miniature inertial sensors in the future. . Gyroscopes and accelerometers are the core inertial sensors for the measurement and control of carrier motion attitude, and gyroscopes are sensors that are sensitive to angular parameters such as angular velocity and angular acceleration. The traditional miniature gyroscope (micromechanical gyroscope) is based on t...

AI Technical Summary

Problems solved by technology

A Chinese patent for a miniature four-channel circulating flow three-axis silicon jet gyroscope (patent application number: 201510385582.4), which belongs to the miniature jet gyroscope, the piezoelectric film in the sensitive element increases the processing difficulty and cost, and under the premise of maintaining the flow rate Its size is difficult to further reduce

In Chinese patents 201410140298.6 and 201210130318.2, the main components in the sensor sensitive element-heater and thermistor both adopt a suspended cantilever beam structure. First, since the heater and thermistor are suspended above the cavity, after the cavity is etched to release the structure , the stress will cause the heater and thermistor to deform or even break, the yield is low, and the warping deformation will produce an asymmetric gas flow field without angular velocity input, resulting in angular velocity detection error

Secondly, the extraction circuit and the sensitive element chip of the sensor are separated, and the extraction circuit needs to be additionally fabricated, and it is not integrated with the sensitive element on a chip, so the integration level is not high, and the sensor is bulky

Third, if the resistors in the four-arm bridge in this discrete device are not in the same temperature field, the temperature coefficients of each resistor will be different, which will easily cause temperature drift and affect the accuracy of the sensor, thereby limiting its application field

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