Title :
Characterization of ultra-thin quarter-wavelength matching layers of high frequency ultrasonic transducers
Author :
Wang, Haifeng ; Cao, Wenwu ; Zhou, Qifa ; Shung, K. Kirk
Author_Institution :
Mater. Res. Inst., Pennsylvania State Univ., University Park, PA, USA
Abstract :
The quarter-wavelength (λ/4) acoustic matching layer is a vital component in medical ultrasonic transducers, which can bridge the large acoustic impedance mismatch between the piezoelectric material and the human body. At high frequencies (>50MHz), the λ/4 matching layers become extremely thin and the characterization of its properties becomes very challenging. We report a novel method to measure the phase velocity and attenuation of ultra-thin layers using the λ/4 matching principle. The method has been successfully used to measure a 14.6 μm Epo-Tek 301 epoxy film on glass substrate and a 9.5 μm sol-gel silicon oxide colloidal/polymer composite film on Si substrate.
Keywords :
acoustic impedance; attenuation measurement; biomedical transducers; piezoelectric materials; polymer films; sol-gel processing; ultrasonic transducers; velocity measurement; λ/4 matching principle; 14.6 micron; 9.5 micron; Epo-Tek 301 epoxy film; Si substrate; acoustic impedance; attenuation measurement; glass substrate; human body; medical ultrasonic transducers; phase velocity measurement; piezoelectric material; polymer composite film; sol-gel silicon oxide colloidal; ultra thin quarter wavelength matching layers; Biomedical acoustics; Bridges; Frequency; Humans; Impedance; Piezoelectric materials; Polymer films; Semiconductor films; Substrates; Ultrasonic transducers;
Conference_Titel :
Ultrasonics, 2003 IEEE Symposium on
Print_ISBN :
0-7803-7922-5
DOI :
10.1109/ULTSYM.2003.1293579
