Acoustic surface wave pressure sensor and acoustic surface wave temperature sensor

Abstract

The invention discloses an acoustic surface wave pressure sensor and an acoustic surface wave temperature sensor which can improve pressure-measuring sensitivity or a temperature frequency response speed and comprise a top cover and a base. The top cover and the base are sealed and mounted together, and metal electrodes penetrate through the base which is provided with a pressure conduction through hole; a fluid septum is sealed and fixed on the inner surface of the base to cover the pressure conduction through hole; a closing cavity is formed among the base, the top cover and the fluid septum; both ends of a substrate are fixed on the fluid septum, and the substrate bridges the pressure conduction through hole; an acoustic surface wave pressure sensing resonator and a datum resonator which are arranged on the substrate and the substrate are mutually parallel along the length direction; an acoustic surface wave temperature sensing resonator forms a horizontal included angle with the datum resonator; the acoustic surface wave pressure sensing resonator rightly faces to the central part of the pressure conduction through hole; the acoustic surface wave temperature sensing resonator, the acoustic surface wave pressure sensing resonator and the datum resonator are respectively connected with corresponding bonding pads; the metal electrodes are correspondingly connected with the two bonding pads; and a frontal projected area of a pressure sensitive area on the substrate is smaller than a cross section area of the pressure conduction through hole.

Description

technical field [0001] The invention relates to a surface acoustic wave pressure and temperature sensor. Background technique [0002] The surface acoustic wave sensor can be used to detect the size of pressure and temperature. The detected physical quantity acts on the substrate, which changes the propagation performance of the surface acoustic wave on the substrate, thereby changing the resonant frequency of the surface acoustic wave resonator. By detecting The change of the resonant frequency of the surface acoustic wave resonator can obtain the change of the measured physical quantity. Especially when the measured object is inaccessible or inside a moving object, the surface acoustic wave sensor is favored due to its passive and wireless advantages. [0003] The pressure detection sensitivity of the currently disclosed surface acoustic wave sensors that can measure pressure and temperature at the same time is generally not high, and most of them are used to measure high...

AI Technical Summary

Problems solved by technology

However, if the base is made of engineering plastics, a more general packaging material (this is especially important when the weight and wireless communication requirements are not suitable for metal packaging), a certain thickness is usually required, which causes Sensor does not respond quickly enough to temperature

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