Piezoelectric micro mechanical ultrasonic transducer with multiple piezoelectric layers

Abstract

The invention belongs to the technical field of micro electro mechanical systems, and particularly relates to a piezoelectric micro mechanical ultrasonic transducer with multiple piezoelectric layers. The piezoelectric micro mechanical ultrasonic transducer comprises a composite film, a supporting structure and a substrate; the supporting structure is a hollow thin layer, and the supporting structure is bonded with the substrate corresponding to the free boundary of the composite film adhering to the upper portion of the supporting structure; the composite film comprises a neutral layer, at least one piezoelectric layer and a plurality of metal layers; and the piezoelectric layers and the metal layers in the composite film jointly drive the film structure to vibrate up and down through the polarization direction of the piezoelectric layers and the configuration of electrical connection. The piezoelectric effect can be utilized to effectively accumulate the bending moment at the sections of components, and improve the sensitivity of a sensor. The composite film can be released and supported in a manner of forming an etching cavity below the composite film, manufacturing a through hole by using a deep etching method or welding to a chip pin to form a supporting point, so that sound waves are emitted and received through a load medium (air, water, oil and the like).

Description

Technical field[0001]The present invention belongs to the field of microelectromechanical technology, and is specifically involved in a piezoelectric micro-mechanical ultrasound transducer.Background technique[0002]Ultrasound imaging with no-to-electric side effects, high sensitivity, real-time imaging, and has the advantages of medical imaging and industrial non-destructive testing in medical imaging and industrial non-destructive testing. An important core component of its system is an ultrasonic transducer for the conversion between electrical energy of imaging signal and ultrasonic mechanical energy. Currently commonly used transducer probes are split and linked by piezoelectric ceramics or single crystal, by machining, etc., but due to its high processing difficulty, it is not compatible with integrated circuit processes, and cannot be made to make large-scale preparation and multi-chip packaging. Innovation and application of high frequency phase control array imaging, miniatu...

AI Technical Summary

Problems solved by technology

At present, the commonly used transducer probes are made of piezoelectric ceramics or single crystals, and the division and connection of the units are realized by mechanical processing. However, due to the high processing difficulty and incompatibility with the integrated circuit process, large-scale preparation and multi-chip packaging cannot be performed. , limiting the innovation and application of high-frequency phased array imaging, miniaturization applications and portable systems

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