CN-117358560-B - Flexible ultrasonic linear array transducer

Abstract

The invention discloses a flexible ultrasonic linear array transducer. The flexible ultrasonic linear array transducer comprises a flexible backing layer, a flexible matching layer and a piezoelectric layer arranged between the flexible backing layer and the flexible matching layer, wherein the piezoelectric layer comprises a signal electrode flexible circuit board at the side of the flexible matching layer, a ground electrode flexible circuit board at the side of the flexible backing layer and a plurality of piezoelectric array elements arranged between the signal electrode flexible circuit board and the ground electrode flexible circuit board, and gaps filled with flexible isolation materials are arranged among the piezoelectric array elements. The signal electrode flexible circuit board can realize independent excitation of each piezoelectric array element, the ground electrode flexible circuit board can realize common ground connection of each piezoelectric array element, the signal electrode flexible circuit board, the ground electrode flexible circuit board and the flexible isolation material filled in gaps of the array elements realize integral flexibility of the piezoelectric layer, and the obtained flexible ultrasonic linear array transducer is provided with an integrated flexible unit.

Inventors

• LIANG RUIHONG
• CHENG DONGXU
• YUE QINGWEN
• DONG XIANLIN

Assignees

• 中国科学院上海硅酸盐研究所

Dates

Publication Date

20260512

Application Date

20220630

Claims (8)

1. 1. A flexible ultrasonic linear array transducer is characterized by comprising a flexible backing layer, a flexible matching layer and a piezoelectric layer between the flexible backing layer and the flexible matching layer, wherein the material of the flexible matching layer is epoxy resin containing zirconia powder, the material of the flexible backing layer is polydimethylsiloxane containing tungsten powder, the piezoelectric layer comprises a signal electrode flexible circuit board at the side of the flexible matching layer, a ground electrode flexible circuit board at the side of the flexible backing layer and a plurality of piezoelectric array elements between the signal electrode flexible circuit board and the ground electrode flexible circuit board, gaps filled with flexible isolation materials are arranged among the piezoelectric array elements, the flexible isolation materials are polyurethane or polydimethylsiloxane, the piezoelectric layer is prepared by using a cutting filling method, the piezoelectric composite material sheet is then prepared into a plurality of piezoelectric layers with independent piezoelectric array elements by using the cutting filling method, the piezoelectric composite material sheet is further bonded with the signal electrode flexible circuit board at two sides of the piezoelectric composite material sheet, the signal electrode flexible circuit board and the ground electrode flexible circuit board are mutually connected with the signal electrode flexible circuit board in a penetrating mode, the flexible circuit board is excited by the signal electrode flexible circuit board is further processed by the piezoelectric composite material sheet, and the flexible circuit board is cut through the flexible circuit board is not subjected to the flexible circuit board, and the flexible circuit board is completely corresponding to the flexible circuit is cut by the flexible circuit board, the ground electrode flexible circuit board is provided with a single pad for commonly connecting a plurality of piezoelectric array elements and a plurality of mutually connected ground electrodes.
2. 2. The flexible ultrasonic linear array transducer of claim 1, wherein each piezoelectric array element has a ground electrode on the ground electrode flexible circuit board side electrically connected to the electrode area of the ground electrode flexible circuit board and a signal electrode on the signal electrode flexible circuit board side electrically connected to the electrode area of the signal electrode flexible circuit board, respectively.
3. 3. The flexible ultrasonic linear array transducer of claim 1, wherein the projection of the electrode area of the ground electrode flexible circuit board and the electrode area of the signal electrode flexible circuit board in the vertical direction coincide.
4. 4. The flexible ultrasonic linear array transducer of claim 1, wherein the piezoelectric array elements are in the form of a linear array one-dimensionally arranged along the x-direction.
5. 5. The flexible ultrasonic linear array transducer of claim 1, wherein each piezoelectric array element has a plurality of piezoelectric ceramic posts and epoxy filled between the piezoelectric ceramic posts, and the pitch of the piezoelectric ceramic posts in the x-direction is the same as the pitch of the piezoelectric array elements in the x-direction.
6. 6. The flexible ultrasonic linear array transducer of claim 1, wherein the piezoelectric material of the piezoelectric array element is lead zirconate titanate ceramic.
7. 7. The flexible ultrasonic linear array transducer of claim 1, wherein the zirconia powder comprises 120-160% of epoxy resin by mass in the material of the flexible matching layer.
8. 8. The flexible ultrasonic linear array transducer of claim 1, wherein tungsten powder comprises 300-500% of polydimethylsiloxane by mass in the material of the flexible backing layer.

Description

Flexible ultrasonic linear array transducer Technical Field The invention relates to the field of flexible sensors, in particular to a flexible ultrasonic linear array transducer. Background The ultrasonic imaging technology has the advantages of safety, intuitiveness, wide application range, strong discrimination of soft tissues, repeated examination, flexibility, low cost and the like, and becomes the first choice of the contemporary imaging technology. As a key component of the ultrasonic imaging system, the price of the ultrasonic transducer occupies 10% -40% of the price of the whole system. Ultrasonic transducers are of many kinds, the most common of which is piezoelectric ultrasonic transducers, which use piezoelectric materials to generate ultrasonic signals and receive echo signals, and then back-end process the received echo signals to finally realize ultrasonic imaging. Piezoelectric materials are the core component of the overall transducer, and high electromechanical coupling coefficients and piezoelectric constants, as well as suitable dielectric constants and acoustic impedances, are important developments in piezoelectric materials for ultrasonic transducers. Lead zirconate titanate (PZT) ceramic has been the main material for manufacturing piezoelectric ultrasonic transducers since the advent of the technology, due to its high piezoelectric constant d 33, low cost, and easy manufacturing. However, the excessively large acoustic impedance and low electromechanical coupling coefficient k t of PZT ceramics limit the performance of the ultrasonic transducer fabricated therefrom. The PZT ceramic is made into piezoelectric composite material to replace pure ceramic, and is a good method for improving the performance of the transducer. Compared with ceramics, the piezoelectric composite material has higher electromechanical coupling coefficient, easy-to-regulate acoustic impedance and dielectric constant and low mechanical quality factor, and is especially suitable for manufacturing high-sensitivity and high-bandwidth transducers. The transducers may be divided into single array elements and array transducers according to the number of array elements. The array transducer obtains images by adopting an electronic scanning method, and has the advantages of high scanning frame rate, high scanning precision, dynamic focusing capability and the like compared with a single array element transducer. The current transducer is generally a rigid structure, and has some limitations in practical application, such as difficulty in detecting a non-planar three-dimensional surface. The flexible ultrasonic transducer can solve the problem, can form conformal contact with a complex surface, and has the advantages of small mass, ultrathin appearance, wearable and implantable performance and the like. Disclosure of Invention Aiming at the defects of the existing rigid ultrasonic transducer, the invention provides the flexible ultrasonic linear array transducer, the signal electrode flexible circuit board can realize independent excitation of each piezoelectric array element, the ground electrode flexible circuit board can realize common ground connection of each piezoelectric array element, and the flexible isolation materials filled in gaps among the signal electrode flexible circuit board, the ground electrode flexible circuit board and the array elements realize integral flexibility of a piezoelectric layer, so that the obtained flexible ultrasonic linear array transducer has an integrated flexible unit and has the advantages of small volume, thin appearance, wearing, easiness in preparation and the like. The flexible ultrasonic linear array transducer comprises a flexible backing layer, a flexible matching layer and a piezoelectric layer arranged between the flexible backing layer and the flexible matching layer, wherein the piezoelectric layer comprises a signal electrode flexible circuit board at the side of the flexible matching layer, a ground electrode flexible circuit board at the side of the flexible backing layer and a plurality of piezoelectric array elements arranged between the signal electrode flexible circuit board and the ground electrode flexible circuit board, and gaps filled with flexible isolation materials are arranged among the piezoelectric array elements. Preferably, the signal electrode flexible circuit board is provided with a plurality of independent pads and signal electrodes for independently exciting the corresponding piezoelectric array elements, and the ground electrode flexible circuit board is provided with a single pad and a plurality of mutually connected ground electrodes for commonly connecting the plurality of piezoelectric array elements. Preferably, each piezoelectric array element is provided with a ground electrode which is electrically connected with the electrode area of the ground electrode flexible circuit board on the ground electrode flexible circuit board side and