Characterization of ultra-thin quarter-wavelength matching layers of high frequency ultrasonic transducers

Haifeng Wang, Wenwu Cao, Qifa Zhou, K. Kirk Shung

Research output: Contribution to journalConference article

2 Scopus citations


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 14.6μm Epo-Tek 301 epoxy film on glass substrate and a 9.5μm sol-gel silicon oxide colloidal/polymer composite film on Si substrate.

Original languageEnglish (US)
Pages (from-to)1048-1051
Number of pages4
JournalProceedings of the IEEE Ultrasonics Symposium
StatePublished - Dec 1 2003
Event2003 IEEE Ultrasonics Symposium - Proceedings - Honolulu, HI, United States
Duration: Oct 5 2003Oct 8 2003


All Science Journal Classification (ASJC) codes

  • Acoustics and Ultrasonics

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