Fabrication and high acoustic performance of high frequency needle ultrasound transducer with PMN-PT/Epoxy 1-3 piezoelectric composite prepared by dice and fill method

Abstract

In this paper, we reported the fabrication and high acoustic performance of high frequency needle ultrasound transducer based on 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 single crystal/Epoxy 1–3 piezoelectric composite, which was prepared by using the dice and fill (DAF) method. The as-prepared 0.70PMN-0.30 PT/Epoxy 1–3 composite has high thickness extension mode electromechanical coupling coefficient with the value of 67.3 %. The transducer is designed by PMN-PT/Epoxy 1–3 piezoelectric composite with a dimension of 550 μm × 450 μm × 35 μm. The fabricated transducer has not only a high center frequency larger than 42 MHz, but also high bandwidth of -6 dB of 90.6 %, the insertion loss with the value of 16 dB and excellent transmitting sensitivity of 314 mV/V. The results are in good agreement with the values simulated by PiezoCAD software. In addition, the acoustic performance of the transducer was also obtained by measuring the acoustic filed distribution in purified water. The -3 dB acoustic beam dimension width, the value of focal length and the acoustic power were 0.38 mm × 0.42 mm, 2.3 mm and 4.4 × 10−3mW, respectively. The performance PMN-PT/Epoxy 1–3 piezoelectric composite ultrasound transducer fabricated by dice and fill method (DAF) achieved the effect of ultrasonic transducer fabricated by deep reactive ion etching (DRIE). The excellent acoustic performance demonstrated that the DAF prepared PMN-PT/Epoxy 1–3 piezoelectric composite have great industry application potential in high frequency ultrasonic electronics, such as microelectronics NDT and biomedical imaging.