The designing and manufacturing of 1MHz Piezoelectric Micro-Machined Ultrasonic Transducer

This paper has designed a new type of high frequency Piezoelectric Micro-machined Ultrasonic Transducer (PMUT) array in multi-units and parallel connection, based on sacrificial layer technology. It prepared the PMUT whose resonant frequency reached 1 MHz and studied on the process that the released sacrificial layer applied on the PMUT preparation. It measured the admittance frequency response curve of the PMUT, whose resonant frequency was 1.14 MHz, in line with expected result. It implemented the PMUT's transceiver test. From the test, the receiving sensitivity of the PMUT in 1 MHz was -255 dB (ref 1V/μPa), the acoustic pressure output was 131.2 dB (ref 1μPa·m/V), and the -3 dB band was about 68%.