SOQ-based quartz vibration beam accelerometer chip with flexible amplifying mechanism

Abstract

An SOQ-based quartz vibration beam accelerometer chip with a flexible amplifying mechanism comprises a quartz structure and a silicon structure which are bonded. The silicon structure comprises an in-plane differential quartz vibrating beam chip structure which is composed of a quartz frame, a quartz tuning fork, a connecting rod, a lever, a hinge, a mass block, an input end and an etching clearance. The silicon structure comprises a silicon frame which is internally provided with a discharging trough. The quartz frame is totally bonded with the silicon frame. The quartz tuning fork, the connecting rod, the lever, the hinge, the mass block and the etching clearance are totally suspended on the discharging trough. The input end, the hinge, the lever and the connecting rod form a lever amplifying mechanism together. When the mass block generates an inertial force through an acceleration function, the inertial force is transferred to the lever through the input end; and after amplification by the lever, the inertial force is transferred to the connecting rod; the connecting rod firstly focuses the force and uniformly divides the inertial force to two vibrating beams of the quartz tuning fork, thereby affecting the frequency of the vibrating beams. The acceleration is measured through a frequency difference of the vibrating beams at two ends. The SOQ-based quartz vibration beam accelerometer chip has advantages of high sensitivity, small size, etc.

Description

technical field [0001] The invention belongs to the technical field of MEMS digital accelerometers, in particular to a SOQ (silicon on quartz) quartz vibrating beam accelerometer chip with a flexible amplification mechanism. Background technique [0002] The traditional quartz vibrating beam accelerometer is limited by the difficulty of quartz processing technology. Often, the tuning fork vibrating beam and the base material are processed separately, and silicon or metal materials that are easier to process are used to process the sensitive mass and supporting parts. The quartz vibrating beam is processed by wet or dry etching process, and then assembled together. This assembly avoids the difficulty of the overall processing of quartz, but it will introduce assembly errors into the sensor. For accelerometers with differential structures, it cannot be completely poor. The dynamic structure cannot effectively eliminate the common mode interference, which will affect the accura...

AI Technical Summary

Problems solved by technology

[0002] The traditional quartz vibrating beam accelerometer is limited by the difficulty of quartz processing technology. Often, the tuning fork vibrating beam and the base material are processed separately, and silicon or metal materials that are easier to process are used to process the sensitive mass and supporting parts. The quartz vibrating beam is processed by wet or dry etching process, and then assembled together. This assembly avoids the difficulty of the overall processing of quartz, but it will introduce assembly errors into the sensor. For accelerometers with differential structures, it cannot be completely poor. The dynamic structure cannot effectively eliminate common-mode interference, which will affect the accuracy of the sensor

In addition, because of the two vibrating beams of the tuning fork, most of the quartz beam acceleration sensors that use levers to amplify adopt the form of symmetrical placement of two levers to achieve the same effect of the internal stress of the two vibrating beams, which will be affected by the length of the lever. The limit makes the amplification effect greatly reduced; or instead of using the tuning fork, only one vibrating beam is used as the resonator, but if there is only one vibrating beam, the external interference is serious, and it is often used with a vibration isolation structure, so that the overall structure of the chip is too big

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