SOI complete silicon structure silicone-oil-filling high-temperature-resistance pressure sensor

Abstract

SOI all-silicon structure silicone oil-filled high temperature pressure sensor, including a base 4 with a cavity, a corrugated diaphragm 7 and a pressure ring 5 are sequentially arranged on the cavity of the base 4, the electrode 1 is connected to the base 4 through a glass insulator 2 Phase-fixed, the cavity of the base 4 is also equipped with an all-silicon SOI pressure chip 9 with a (100) crystal plane, and the all-silicon SOI pressure chip 9 is sealed with the PYREX7740 glass 6 by electrostatic bonding in a vacuum environment. The cavity of the seat 4 is filled with high-temperature silicone oil 13, and the pressure-bonding block on the all-silicon SOI pressure chip 9 is connected with the electrode 1 by the gold wire 8 for ultrasonic hot-pressure welding, which solves the problem of measuring a large range of pressure in a high-temperature environment. At the same time, it has the characteristics of good dynamic characteristics, high temperature resistance (≥200℃), high precision, large measuring range (60~150MPa), miniaturization, safe and reliable operation and strong adaptability.

Description

technical field [0001] The invention relates to a pressure sensor, in particular to an SOI all-silicon structure filled with silicon oil, high-range, and high-temperature-resistant pressure sensor. Background technique [0002] At present, high-range pressure sensors generally adopt piezoelectric, strain-type or piezoresistive structural principles. The output signal of the piezoelectric pressure sensor is the amount of charge change, so the subsequent signal processing circuit is relatively cumbersome and the piezoelectric pressure sensor is not suitable for use in high temperature environments, and does not have high overload protection capabilities. A high-range pressure sensor using metal strain gauges as sensitive elements, the biggest disadvantage of this type of sensor is that the output signal is too small, and in a high temperature environment, the temperature has a greater impact on the deformation of the metal strain gauge, affecting the output of the sensor, not ...

AI Technical Summary

Problems solved by technology

The output signal of the piezoelectric pressure sensor is the amount of charge change, so the subsequent signal processing circuit is relatively cumbersome and the piezoelectric pressure sensor is not suitable for use in high temperature environments, and it does not have the ability of high overload protection

A high-range pressure sensor using metal strain gauges as sensitive elements, the biggest disadvantage of this type of sensor is that the output signal is too small, and in a high temperature environment, the temperature has a greater impact on the deformation of the metal strain gauge, affecting the output of the sensor, not applicable in high temperature environment

Among piezoresistive pressure sensors, the most commonly used sensor structures are silicon oil-filled full-silicon pressure sensors and dry-type piezoresistive pressure sensors, and silicone oil-filled full-silicon piezoresistive pressure sensors generally use PN junction isolation technology, resulting in their operating temperature The maximum temperature is about 80°C, and due to the influence of the structure of the all-silicon pressure chip, the maximum pressure range is below 40MPa; the dry piezoresistive pressure sensor, although it adopts some isolation measures and technologies for high temperature resistance, has the characteristics of high temperature resistance and high range However, due to the influence of the sensor packaging structure, such as beam membrane type, diaphragm type and other structures, the sensor has a large static error such as line line and hysteresis when measuring high voltage.

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