Multi-piezoelectric layer ultrasonic transducer for medical imaging
AssigneeParallel Design, Inc.
InventorsSanjay Chandran, David Chartrand
Life of this patent
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Abstract
A transducer is tuned to a desired impedance by building piezoelectric assemblies of multiple layers, each layer acting as a parallel capacitor. Piezoelectric layers are preferably constructed by plating or otherwise placing a conducting perimeter around a piezoelectric substrate. Gaps are suitably formed in the conducting layer by dicing or otherwise to form distinct electrical conducting regions on each layer. Piezoelectric layers are then suitably placed such that positive and negative conducting regions on each layer contact positive and negative regions on other layers. Layers are suitably joined by epoxy or by any other joining technique.
Claims16
A method of fabricating a piezoelectric assembly in a transducer, the method including the steps of:
- providing a first dielectric layer and a second dielectric layer;
- coating at least a portion of each of said first and second dielectric layers with a conducting material;
- forming a first gap and a second gap in said conducting material coating said first dielectric layer to define a first electrode and a second electrode;
- forming a third gap and a fourth gap in said conducting material coating said second dielectric layer to define a third electrode and a fourth electrode;
- placing said first and second dielectric layers proximate to each other such that said first and third electrodes are in electrical communication with each other, and such that said second and fourth electrodes are in electrical communication with each other;
- and
- affixing said first dielectric layer to said second dielectric layer.
A method of formulating a transducer having a predetermined impedance, the method comprising the steps of:
- formulating a piezoelectric assembly having a front face and a back face;
- attaching said front face of said piezoelectric assembly to an acoustic matching layer;
- and
- attaching a first electrical lead and a second electrical lead to said piezoelectric assembly;
- wherein the step of formulating a substrate layer comprises the substeps of:
- providing a plurality of piezoelectric layers, each of said plurality of piezoelectric layers having a substrate at least partially coated with an electrical conductor, each electrical conductor having a first cut and a second cut defining a first electrode and a second electrode;
- aligning said piezoelectric layers such that said plurality of first electrodes are in electrical communication with each other and with said first electrical lead, and said plurality of second electrodes are in electrical communication with each other and with said second electrical lead to form a plurality of capacitive elements;
- and
- joining said sublayers to each other with an adhesive.
Dependencies are inferred from the claim text.