SAW pressure sensor and method for fabricating the sensor part

Abstract

The invention relates to an SAW pressure sensor, which is characterized in that the SAW pressure sensor comprises two parts, namely a sensor and a wireless readout circuit, wherein the sensor comprises a substrate which is made of silicon materials; the rear middle of the substrate is thinned into a film structure which is a high deformation area of the substrate, and the other part of the substrate is a fixed end of the substrate; a piezoelectric material film covers the facade of the substrate; two groups of SAW elements are symmetrically arranged on the piezoelectric material film; each SAWelement comprises a radio-frequency transducer, a reflector and a muffler; each group of SAW elements correspond to a frequency respectively; the radio-frequency transducer is positioned on the fixedend of the substrate; the reflector is positioned on the high deformation area of the substrate; the muffler is positioned on a prolonging line of a link of the radio-frequency transducer and the reflector; and the wireless readout circuit comprises a radio-frequency system and a processing system and is used for wirelessly reading out the pressure of the sensor. The SAW pressure sensor utilizesthe SAW elements to realize passive and wireless pressure measurement, and has the characteristics of simple manufacture, wide temperature adaptation range and strong electromagnetic interference resistance.

Description

technical field [0001] The invention relates to a pressure sensor, in particular to a wireless passive automobile tire SAW (surface acoustic wave) pressure sensor and a manufacturing method of the sensor part thereof. Background technique [0002] Due to the particularity of car tires, the usual sensors are limited in connection and cannot measure car tire pressure. Therefore, it is required that the sensor used in automobile tire pressure measurement has the function of wirelessly reading out the measurement results. In addition, due to the airtightness of the working environment of the sensor used for automobile tire pressure measurement, it is impossible to replace the battery of the sensor frequently, which requires reducing the power consumption of the sensor as much as possible. Traditional wireless sensor systems include active devices, radio frequency circuits and other high power consumption circuits, which are not suitable for long-term work when powered by batter...

AI Technical Summary

Problems solved by technology

However, these sensors have low measurement sensitivity and complex structures, which are not suitable for precise measurement and large-scale industrial production in a large range.

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