Cristin-resultat-ID: 1047338
Sist endret: 5. november 2014, 13:37
NVI-rapporteringsår: 2013
Resultat
Vitenskapelig artikkel
2014

Microfabrication of stacks of acoustic matching layers for 15 MHz ultrasonic transducers

Bidragsytere:
  • Tung Manh
  • Anh Tuan Thai Nguyen
  • Tonni Franke Johansen og
  • Lars Hoff

Tidsskrift

Ultrasonics
ISSN 0041-624X
e-ISSN 1874-9968
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2014
Publisert online: 2013
Trykket: 2014
Volum: 54
Hefte: 2
Sider: 614 - 620

Importkilder

Scopus-ID: 2-s2.0-84888875093
Isi-ID: 000326938900023

Beskrivelse Beskrivelse

Tittel

Microfabrication of stacks of acoustic matching layers for 15 MHz ultrasonic transducers

Sammendrag

This paper presents a novel method used to manufacture stacks of multiple matching layers for 15 MHz piezoelectric ultrasonic transducers, using fabrication technology derived from the MEMS industry. The acoustic matching layers were made on a silicon wafer substrate using micromachining techniques, i.e., lithography and etch, to design silicon and polymer layers with the desired acoustic properties. Two matching layer configurations were tested: a double layer structure consisting of a silicon–polymer composite and polymer and a triple layer structure consisting of silicon, composite, and polymer. The composite is a biphase material of silicon and polymer in 2-2 connectivity. The matching layers were manufactured by anisotropic wet etch of a (1 1 0)-oriented Silicon-on-Insulator wafer. The wafer was etched by KOH 40 wt%, to form 83 μm deep and 4.5 mm long trenches that were subsequently filled with Spurr’s epoxy, which has acoustic impedance 2.4 MRayl. This resulted in a stack of three layers: The silicon substrate, a silicon–polymer composite intermediate layer, and a polymer layer on the top. The stacks were bonded to PZT disks to form acoustic transducers and the acoustic performance of the fabricated transducers was tested in a pulse-echo setup, where center frequency, −6 dB relative bandwidth and insertion loss were measured. The transducer with two matching layers was measured to have a relative bandwidth of 70%, two-way insertion loss 18.4 dB and pulse length 196 ns. The transducers with three matching layers had fractional bandwidths from 90% to 93%, two-way insertion loss ranging from 18.3 to 25.4 dB, and pulse lengths 326 and 446 ns. The long pulse lengths of the transducers with three matching layers were attributed to ripple in the passband.

Bidragsytere

Tung Manh

  • Tilknyttet:
    Forfatter
    ved Institutt for mikrosystemer ved Universitetet i Sørøst-Norge

Thai Anh Tuan Nguyen

Bidragsyterens navn vises på dette resultatet som Anh Tuan Thai Nguyen
  • Tilknyttet:
    Forfatter
    ved Institutt for mikrosystemer ved Universitetet i Sørøst-Norge

Tonni Franke Johansen

  • Tilknyttet:
    Forfatter
    ved Sustainable Communication Technologies ved SINTEF AS
  • Tilknyttet:
    Forfatter
    ved Institutt for sirkulasjon og bildediagnostikk ved Norges teknisk-naturvitenskapelige universitet

Lars Hoff

  • Tilknyttet:
    Forfatter
    ved Institutt for mikrosystemer ved Universitetet i Sørøst-Norge
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