A silicon microresonant pressure sensor chip with double H-shaped tensile beams and its preparation method

Abstract

The invention discloses a double H-type tension beam silicon micro-resonance pressure sensor chip and a preparation method thereof. The double H-type tension beam silicon micro-resonance pressure sensor chip comprises a resonator and a pressure sensitive membrane; the resonator includes resonant beams and torsion beams; four resonant beams form a group of H-beam, and two groups of H-beams are oppositely arranged; the extension parts of one end of two adjacent resonant beams are connected to the same torsion beam; the other end of each resonant beam is connected to a mass block; a coupling beamis arranged in the middle of the mass block, and a vibration pick-up resistor is arranged in the middle of the coupling beam; the two sides of the mass block are fixedly connected to two movable electrodes separately; fixed electrodes are arranged on the outside of the two movable electrodes; both ends of the fixed electrode are fixedly connected to fixed electrode anchor points; and the resonator is connected to the anchor points through connection points. The amplification principle of the anchor points is used for amplifying the stress and deformation of the pressure sensitive membrane, and then the amplified stress and deformation of the pressure sensitive membrane is transmitted to the resonator, so that the double H-beam is pulled, and the sensitivity of the sensor is improved; andthrough the symmetrical double H-type beam design, the direct energy exchange between the resonant beams and the pressure sensitive membrane is effectively avoided, and the quality factor of the sensor is improved.

Description

technical field [0001] The invention belongs to the technical field of micro-nano sensors, and in particular relates to a silicon micro-resonance pressure sensor chip with double H-shaped tension beams and a preparation method thereof. Background technique [0002] Silicon microresonant pressure sensor, as the sensor technology that represents the highest level of pressure sensors in the world and has the most comprehensive technical advantages, can be applied to airborne air data test systems, aviation air data calibrators, cabin pressure tests, and aerospace ground test systems And high-performance wind tunnels and other fields, can be made into pressure probes embedded in the fuselage, wings, etc. for distributed pressure measurement. core device. [0003] Compared with electrostatic excitation and piezoresistive detection mechanism, other commonly used working methods of silicon microresonant pressure sensors have the following disadvantages: (1) Compared with electrost...

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Problems solved by technology

[0003] Compared with electrostatic excitation and piezoresistive detection mechanism, other commonly used working methods of silicon microresonant pressure sensors have the following disadvantages: (1) Compared with electrostatic excitation, thermal excitation is a contact excitation method, which will damage the surface of the resonator , the heat generated during the excitation process will cause the frequency deviation of the resonator, which will affect the stability and measurement accuracy of the sensor. Thermal excitation needs to complete the conversion of electrical energy-thermal energy-mechanical energy, which will cause a large sensor when it is working. In addition, the thermal excitation process responds slowly, which will reduce the response speed of the sensor; (2) Compared with piezoresistive detection, capacitive detection is susceptible to environmental interference, which is a detection method with weak anti-interference ability; (3) Electromagnetic Excitation and electromagnetic detection require an external magnetic field, making it difficult to miniaturize the sensor

The piezoresistive pickup resonant silicon micro pressure sensor designed by DRUCK company has a complex pickup structure, which increases the difficulty of processing; at the same time, in order to improve the detection accuracy, the resonator needs a higher Q value; in order to reduce the difficulty of closed-loop control, the resonance should be guaranteed tor resonant state stable output

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