Piezoresistive high-frequency high-temperature dynamic pressure sensor

Abstract

The invention discloses a piezoresistive high-frequency high-temperature dynamic pressure sensor, which consists of a piezoresistance sensitive component, a sensor metal shell, and a high-frequency broadband amplifier, wherein the piezoresistance sensitive component consists of a silicon piezoresistance sensitive component and a glass ring piece; the silicon piezoresistance sensitive component is formed by a circular-flat silicon diaphragm which is sequentially covered by a SiO2 layer and a Si3N4 layer on the front; the middle part of the front of the silicon piezoresistance sensitive component is provided with a Wheatstone bridge, while the silicon diaphragm is exposed at the periphery of the silicon piezoresistance sensitive component and is firmly welded to the glass ring piece; the back of the silicon piezoresistance sensitive component is provided with a metal reflective film, and a strain resistor on the Wheatstone bridge is led out by a gold wire internal down-lead; the other side of the glass ring piece is fixed to an annular concave pit surface on a ceramic isolation substrate; the ceramic isolation substrate is sintered and fixed at a pressure inlet port of the sensor metal shell; and after the gold wire internal down-lead on the piezoresistance sensitive component is led to an adapter plate in an inner chamber of the sensor, signals are amplified by the high-frequency broadband amplifier and are led out through an output cable at the tail of the sensor. The piezoresistive high-frequency high-temperature dynamic pressure sensor still has good characteristics when bearing superhigh temperature and superhigh frequency impact.

Description

technical field [0001] The invention relates to a piezoresistive high-frequency high-temperature dynamic pressure sensor capable of resisting transient ultra-high temperature and high frequent impact, in particular to a high-temperature resistant sensor developed based on the combination of MEMS (MicroElectron Mechanical System) technology and SOI (Silicon On Insulator) technology High-frequency dynamic pressure sensor, suitable for ammunition priming energy test experiment technology, high-frequency dynamic pressure measurement accompanied by high-temperature field brought by ultra-close detection, transient ultra-high temperature impact and more frequent, and accompanied by conductivity interference of reaction medium In the working conditions with special requirements such as strong light interference, the frequent measurement of high-temperature and high-frequency dynamic pressure on the order of sub-milliseconds is completed. Background technique [0002] The MEMS techn...

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Problems solved by technology

The miniature square diaphragm made by American Kulite company and Endevco company using this technology has realized the miniaturization of piezoresistive pressure sensor and the high natural frequency of the chip, but they have not solved the problem of full flush packaging, and this kind of packaging cannot solve the problem of explosion. Therefore, the laser-shaped protective film in front of the chip package has to be removed during use to adapt to high-frequency dynamic measurement, resulting in a very high damage rate or one-time use during measurement

[0003] The applicant has stated a flush-packed high-frequency dynamic high-pressure sensor in the previously published patent - piezoresistive high-frequency dynamic high-pressure sensor (patent number: 200510037982.2), which is suitable for testing the shock wave overpressure pressure field in detonation tests Requirements, but because the Wheatstone bridge arm resistors composed of four silicon force sensitive resistors that detect pressure and convert them into electrical signals use PN junction isolation, and the temperature resistance of large-area PN junctions is limited to 125°C. Therefore, the isolation failure caused by PN junction leakage current and breakdown at high temperature makes it unable to be used in environments and media higher than 125°C.

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