Abstract: A transducer assembly is provided including a transducer array comprising a plurality ‘M’ of transducer elements and a sub-aperture processor comprising a plurality ‘P’ of input channels and an output channel. The plurality ‘P’ of input channels is coupled to the ‘M’ transducer elements and a plurality ‘R’ of switching elements in operative association with the output channel of the sub-aperture processor to switchably couple the output channel to at least one of a plurality of ‘N’ system channels.

Abstract: An interconnect assembly is presented. The assembly includes an interconnect structure including a plurality of interconnect layers disposed in a spaced relationship, where each of the plurality of interconnect layers comprises a plurality of conductive traces disposed thereon. Furthermore, the assembly includes a redistribution layer disposed proximate the interconnect structure, where the redistribution layer is configured to facilitate coupling the interconnect structure to the one or more transducer elements on the transducer array.

Abstract: A composite structure of a backing material with enhanced conductivity for use in a transducer is presented. The composite structure includes a plurality of layers of backing material alternatingly arranged with a plurality of thermal conductive elements, wherein the plurality of thermal conductive elements are configured to transfer heat from a center of the transducer to a plurality of points on the composite structure of backing material.

Abstract: A high-density connection of multiple circuit boards having overlapping ends arranged in a stack. The metal traces on the stacked circuit boards are electrically connected by contact of the ends of the traces, which ends may be pads. The stacked circuit boards can be clamped, soldered or bonded together. Multiple circuit boards may be connected to a single circuit board. In one embodiment, double-sided circuit boards are stacked so that a first circuit board connects to a second circuit board through a third circuit board disposed intermediate the first and second circuit boards. The circuit boards may be flexible or rigid.

Abstract: An ultrasound transducer element incorporates material of low dielectric constant to confine the electric field of a stack of piezoelectric ceramic layers. Edge segments made of material having a low dielectric constant and extending in the thickness direction are formed at opposing ends of the multilayer structure. These regions of low dielectric constant material confine the electric field to the piezoelectric ceramic material of high dielectric constant, where it remains directed vertically. In this way, when a voltage is applied between the electrodes, the piezoelectrically induced strains are almost entirely vertical. Spurious modes are therefore substantially reduced.

Abstract: A device comprising an array of sensors built on or in a substrate with a semiconducting surface and means for isolating each sensor element from its neighbors. In the case where the sensors are ultrasonic transducer elements, acoustic isolation is provided in the form of trenches between neighboring transducer elements to reduce acoustic crosstalk. The trenches may be filled with acoustically attenuative material. Electrical isolation in the form of semiconductive junctions is provided between neighboring transducer elements to reduce electrical crosstalk. In one example, back-to-back pn junction diodes are formed by ion implantation in zones located between neighboring transducer elements. These types of isolation can be employed alone or together.

Abstract: A high-density cable of a type suitable for transmitting ultrasound signals from an ultrasonic probe to multiplexing circuitry during a medical ultrasound procedure is provided. The cable includes one or more flexible circuits arranged within a flexible sheath that surrounds and confines the flexible circuits. Each flexible circuit includes an elongate flexible substrate with oppositely-disposed surfaces and multiple conductors on at least one of these surfaces. The opposing longitudinal ends of the substrate define integral connectors for connecting with respective output connectors and/or electronic devices, such as an ultrasonic probe or multiplexing circuitry.

Abstract: To determine electrical resistance of an ohmic contact between a flexible printed circuit and a metallized layer upon a substrate of piezoelectric material, the printed circuit is provided with two exposed metal pads, in close proximity to each other, and two electrical leads from each pad to locations on the printed circuit that are accessible for probing with a four-lead resistance meter. For measurement of contact resistance in process development and process capability studies, many sets of such pads, of a variety of sizes, may be combined into a single printed circuit. For in-process monitoring of transducer manufacturing, a small number of contact resistance measurement pads may be designed into production printed circuits.

Abstract: A multiplexer for connecting a beamformer to a multi-row transducer array, where the transducer array has more electrically independent elements than the beamformer has channels, enables dynamic selection and beamforming control of multi-row apertures. The multiplexer allows the active aperture to be scanned along at least one axis of the array and allows the shape of the active aperture to be varied electronically. The multiplexer supports transmit and receive apertures appropriate for synthetic aperture beamforming. The multiplexer is designed so that each system beamformer channel may be connected to a single transducer element for near-field imaging and to a pair of adjacent transducer elements for far-field imaging.

Abstract: For providing multiple-conductor circuit interconnections where there is a lack of precise dimensional control, as in manufacturing flexible printed circuits used to make high density electrical interconnections between ultrasonic transducer elements and the probe cable in a medical ultrasound probe, connection pads are formed in fanout arrays, with the longitudinal axes of individual pads extending along radial lines from the center of a circle. The fanout arrays are formed within generally trapezoidal areas, each having two parallel opposite sides extending along respective parallel chords to accommodate significant variation in dimensions of the respective substrates being connected. Multiple-row connection pad arrays may be provided, each with a plurality of fanout arrays of connection pads that may be parallel to each other and positioned at respectively different distances from the center of the circle, or may be arranged around, and positioned at equal distances from, the center of the circle.

Abstract: In an ultrasound imaging system, a multiplexer connects a beamformer to a multi-row transducer array, where the array has more electrically independent transducer elements than the beamformer has channels, so as to provide dynamic selection and beamforming control of multi-row apertures. The multiplexer allows the active aperture to be scanned along at least one axis of the array and allows the shape of the active aperture to be varied electronically. The multiplexer, which supports transmit and receive apertures appropriate for synthetic aperture beamforming, is of modular construction, enabling multiplexers appropriate for transducer arrays with various numbers of rows and columns of elements to be easily assembled from a standard set of parts. The multiplexer is physically designed as a passive backplane into which various switch cards can be plugged. The card connectors are arranged in two parallel columns.

Abstract: A multi-row ultrasound transducer array having a central row of transducer elements and a pair of outermost rows of transducer elements on opposing sides of the central row. The corresponding elements of the outermost rows are connected in parallel to a respective signal lead. The area of each element in the central row is less than the combined area of each pair of elements of the outermost rows. The greater total area of the combined elements of the outermost rows as compared to the area of each element of the central row provides improved elevation performance (thinner and more uniform image slice, greater contrast resolution), especially in the very near field, as compared to conventional transducers. The array may further include one or more pairs of rows of elements intermediate the central row and the respective outermost rows. The corresponding elements of the intermediate rows are connected in parallel to respective signal leads.

Abstract: An array ultrasonic transducer precursor includes a body of piezoelectric material with a dielectric substrate bonded to a surface of the body. Circuit elements supported on the dielectric substrate include, in an active region, physically parallel signal conductors arranged in a pattern with spaces between adjacent ones of the conductors. Dicing saw cuts made in these spaces define individual circuit elements within the piezoelectric body. The circuit elements outside the active region include a set of resistive alignment elements in predetermined positions with reference to the pattern of signal conductors. The transducer precursor is mounted in a dicing saw fixture, and initial cuts made with the dicing saw remove portions of the resistive alignment elements. Locations of the initial cuts with reference to the resistive alignment elements are determined by measuring resistances of the resistive alignment elements after the initial cuts.

Abstract: A method for fabricating "1.5D" and "2D" multilayer ultrasonic transducer arrays employs dicing saw kerfs, which provide acoustic isolation between rows. The kerfs are metallized to provide electrical connection between surface electrode layers and buried internal electrode layers. A multilayer piezoceramic transducer element for a "1.5D" or "2D" array produced by this method has higher capacitance, and accordingly provides better transducer sensitivity, in comparison to a single layer element.

Abstract: An array ultrasonic transducer precursor includes a body of piezoelectric material with a dielectric substrate bonded to a surface of the body. Circuit elements supported on the dielectric substrate include, in an active region, physically parallel signal conductors arranged in a pattern with spaces between adjacent ones of the conductors. Dicing saw cuts made in these spaces define individual circuit elements within the piezoelectric body. The circuit elements outside the active region include a set of resistive alignment elements in predetermined positions with reference to the pattern of signal conductors. The transducer precursor is mounted in a dicing saw fixture, and initial cuts made with the dicing saw remove portions of the resistive alignment elements. Locations of the initial cuts with reference to the resistive alignment elements are determined by measuring resistances of the resistive alignment elements after the initial cuts.

Abstract: A method for fabricating "1.5D" and "2D" multilayer ultrasonic transducer arrays employs dicing saw kerfs, which provide acoustic isolation between rows. The kerfs are metallized to provide electrical connection between surface electrode layers and buried internal electrode layers. A multilayer piezoceramic transducer element for a "1.5D" or "2D" array produced by this method has higher capacitance, and accordingly provides better transducer sensitivity, in comparison to a single layer element.