Piezoelectric array ultrasonic transducer

Abstract

The invention provides a piezoelectric array ultrasonic transducer, and belongs to the technical field of transducers and micro-processing. The piezoelectric array ultrasonic transducer comprises array (distributed) type upper electrodes, an integrated common lower electrode, piezoelectric films, insulation layers, array elements, a supporting layer, and monocrystalline silicon basements. The piezoelectric films are arranged between the upper electrodes and the lower electrode. The insulation layers are arranged among the upper electrode, the lower electrode and the piezoelectric films. The array elements arranged on the insulation layers comprises acoustic energy transmission and absorption cavities and vibration films at the bottoms of the array elements. The monocrystalline silicon basements are provided with vibration cavities. By the arrangement of adopting the common lower electrode and the array (distributed) type upper electrodes, same or different thicknesses are adopted in the vibration films at the bottoms of the array elements (the acoustic energy transmission and absorption cavities) and the piezoelectric films, so that the array elements can operate under either a same working frequency or different working frequencies, comprehensive performances of sensitivity and working bandwidth and stability of the comprehensive performances of the transducer can be improved effectively, and the piezoelectric array ultrasonic transducer has the advantages that integration is good, packaging is facilitated, industrial production is benefited and the like.

Description

technical field [0001] The invention belongs to the technical field of transducers and micromachining technology, in particular to a piezoelectric array ultrasonic transducer produced by micromachining technology, and the piezoelectric array ultrasonic transducer can be used as an audio frequency directional speaker on a mobile phone It can also be used as a new type of sensor in the field of medical electronics to detect ultrasound signals in ultrasound, photoacoustic and thermoacoustic imaging systems, and in smart homes for anti-theft systems. Background technique [0002] As a new sensor technology based on micromachining technology, the ultrasonic transducer in the present invention has attracted the attention of many foreign scientific research institutes, especially in the context of the rapid development of the information industry and the Internet of Things industry, it has also attracted attention in the commercial field. highly valued. Piezoelectric ultrasonic tr...

AI Technical Summary

Problems solved by technology

Since the array transducer adopts a common upper electrode setting, the upper electrode is integrated, and the wiring method in which the upper electrode and the lower electrode overlap in space, it is easy to generate parasitic capacitance. Therefore, the arrangement of the upper and lower electrodes of the array transducer It has a great impact on the sensitivity and performance of the device; the lead-out method of each lower electrode wire will seriously affect the safety of the device's packaging and use; in addition, each array element in the device works at the same operating frequency, not only its Narrow bandwidth and low operating frequency

Therefore, the array transducer has disadvantages such as low sensitivity, narrow bandwidth, poor stability and comprehensive performance, difficult packaging, and difficult industrial production.

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