Stack based multidimensional ultrasonic transducer array
AssigneeVermon
InventorsAimé Flesch, An Nguyen-Dinh
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Abstract
Multilayer piezoelectric fabrication methods are used to produce nD (e.g., 1.5D and 2D) ultrasonic transducer arrays. One embodiment concerns a 1.5 linear transducer in which impedance compensation is provided between the elemental transducers forming the array by varying the number of layers in each row of transducers. In another embodiment, a 2D transducer array is provided wherein elemental transducers are produced by dicing a conventional multilayer actuator to form equal sized elements which are embedded in a polymer matrix.
Claims20
An ultrasonic 1.5D transducer array for imaging applications, said array including a plurality of rows of elemental transducers, and
- said elemental transducers of the array being made up of a plurality of layers of a piezoelectric ceramic, and
- the array further including impedance compensation means for providing electrical impedance compensation between different rows of the transducers comprising the array so as to compensate for differences in impedance that would otherwise exist between the different rows of the transducers, and
- means for electrically connecting the transducers of each row independently of each other and for electrically connecting in parallel the layers of piezoelectric ceramic forming the elemental transducers.
A method for producing an ultrasonic multilayer row for a 1.5D transducer array, said array having a pitch, and said method comprising:
- providing a plurality of piezoelectric layers to form a vibrating member having a thickness corresponding to a desired transducer frequency;
- assembling said plurality of layers in reversed polarity to each other to form a parallel electrical circuit;
- providing each layer with two opposed electrodes having outwardly extending conductive lines on opposite lateral faces thereof;
- providing a set of flexible circuits having conductive traces thereon spaced apart by an amount equal to twice the pitch of the array, and disposing said circuits on the opposite lateral faces of said layers so as to connect together all of the conductive lines of said layers;
- and
- bonding said flexible circuits on said opposite lateral faces to the conductive lines at the respective lateral faces.
A method for producing a final multilayer ultrasonic matrix transducer array, said method comprising:
- providing a plurality of multilayer piezoelectric elements of larger dimensions than those of the final array, said multilayer piezoelectric elements including electrical connection wires located around the periphery thereof, and positioning holes located on front surfaces thereof;
- disposing said multilayer piezoelectric elements on a positioning surface to form an intermediate matrix array having the same overall dimensions as and a smaller number of elements than the final array;
- encapsulating the intermediate array of multilayer elements with a polymeric resin to maintain said elements in place;
- providing a backing on one side of the intermediate matrix array;
- sub-dicing the multilayer elements of the intermediate array in quarters to produce the final multilayer matrix transducer array;
- filling dicing grooves formed by said sub-dicing with a flexible resin;
- and
- connecting the final matrix transducer array to cables.
Dependencies are inferred from the claim text.