Composite micro-electro-mechanical system (MEMS) high-temperature resistant ultrahigh-pressure sensor

Abstract

The invention discloses a composite micro-electro-mechanical system (MEMS) high-temperature resistant ultrahigh-pressure sensor. The sensor comprises a base, a silicon beam sensitive element, a high-temperature adapter plate and a shell, wherein the shell is assembled on the base; the silicon beam sensitive element is connected to a high-temperature cable through a gold wire lead and the high-temperature adapter plate and is connected with an external circuit; the base is combined with a foundation support through a pressure-bearing elastic element; the middle of the pressure-bearing elastic element is provided with a circular membrane which is provided with a dowel bar; the silicon beam sensitive element has an E-shaped cup structure of which the middle is provided with a measuring island; the silicon beam sensitive element is assembled on the pressure-bearing elastic element; the measuring island is contacted with the dowel bar; pressure is applied to the circular membrane so as to deform the circular membrane; deflection is applied to the measuring island; and constant current or voltage is processed by the silicon beam sensitive element, and an electric signal which is proportional to a tested pressure is output and transmitted to the external circuit through the gold wire lead, the high-temperature adapter plate and the high-temperature cable so as to realize measurement of the tested pressure. The sensor has the advantages of large measuring range, wide application range, high sensitivity, high signal to noise ratio and the like.

Description

Technical field: [0001] The invention relates to a pressure sensor, in particular to a composite MEMS high temperature and ultra-high pressure sensor. Background technique: [0002] Today's petrochemical, aerospace, military, smelting and other fields generally have measurement problems under high temperature, instantaneous high temperature shock, ultra-high range and other conditions. The high temperature resistant pressure sensor designed for this measurement problem has been extensively researched and applied. Such as SOI silicon piezoresistive pressure sensor, SOS (Silicon on Sapphire) pressure sensor, sputtering film pressure sensor, and high temperature resistant pressure sensor made of silicon strain gauge or high temperature foil strain gauge, etc. From the perspective of measurement mechanism, these sensors are based on the resistance effect; from the perspective of structure, the elastic elements and sensitive elements of these sensors can be divided into two types...

AI Technical Summary

Problems solved by technology

But there are also the following problems: 1) The maximum range does not exceed 150MPa; 2) The measured medium must not only be compatible with the housing material, but must also be compatible with silicon, glass and packaging materials, so the application range is relatively narrow

However, this type of sensor also has certain shortcomings: 1) The sensitive element is packaged on the metal elastic element through a variety of processes, and the sensitive element senses the strain of the metal elastic element to achieve the purpose of detecting pressure

However, the differences in thermal expansion coefficients of sensitive components, metal elastic components and packaging materials will produce packaging residual stress, especially when applied in high temperature environments, it will show problems such as poor stability; 2) If the sensitive component is based on the metal resistance effect , such as sputtered films or pressure sensors using high-temperature foil metal strain gauges, due to the small resistivity of the metal, the piezoresistive coefficient is very low, and the sensitivity of the sensor is very small (only a few mV / V), so the signal-to-noise ratio is poor. Subsequent signal processing circuits have higher requirements

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