Abstract: A transducer for multiple purposes is provided. Different backings are used for different elements of a same array. The different backings optimize the respective elements for the desired use. A soft backing (e.g., Z=3 Mrayl) is used behind some elements for ultrasound imaging. A hard backing (e.g., Z=100 MRayl) is used behind other elements for lower frequency operation.

Abstract: A multi-dimensional transducer array is provided. The multi-dimensional transducer array includes a plurality of elements. First and second kerfs acoustically separate the elements. A first width of the first kerf is larger than a second width of the second kerf.

Abstract: A same transducer includes both piezoelectric and CMUT transducer layers. The semiconductor substrate used for the CMUT is also used as a matching layer. A portion of the semiconductor material is removed and the kerfs or voids are filled to provide the desired density, volume ratio, and/or acoustic impedance. This composite portion operates as a matching layer for the piezoelectric transducer layer.

Abstract: A multi-dimensional transducer array is provided. The multi-dimensional transducer array includes a plurality of elements. First and second kerfs acoustically separate the elements. A first width of the first kerf is larger than a second width of the second kerf.

Abstract: Electrical interconnects are provided for CMUTs. For example, electrodes within the silicon substrate, such as the electrodes at the bottom of the void below membranes, are interconnected together within the substrate. The interconnected electrode may then be used as the grounding electrode. By providing interconnection within the substrate and below the membranes, space for vias and the associated connection between the electrodes on an exposed surface of the substrate is minimized. As another example, an electrical conductor is formed on the side of the silicon substrate rather than the top of the substrate. Conductors on the side may allow routing signals from a top surface to a bottom surface without large wire bonding pads. Alternatively, conductors on the edge provide additional space for wire bonding pads. As yet another example, polymer material used as a matching or protection layer is formed on the top surface of the CMUT with electrical traces routed within the polymer.

Abstract: Backing blocks, transducer arrays and methods are provided for thermal cycle survivability. By decoupling a portion of the backing block from a case used to contain the transducer stack, the greater thermal expansion properties of most backing blocks may be minimized. For example, a rim is formed on the backing block material. The rim is bonded to the case structure while other portions of the backing block remain free of bonding to the case structure. During thermal cycling or other temperature changes, the backing block may be less likely to expand or bulge and crack, delaminate or damage transducer elements or other transducer materials.

Abstract: Matching layers are provided, including: electrically conductive acoustic matching layers, methods for conducting electric current through matching layers, methods for manufacturing multi-dimensional arrays using conductive matching layers, and multi-dimensional arrays with electrically conducting matching layers. Matching layers with conductors aligned for providing electrical conduction through the thickness or range dimension of the matching layer are provided. For example, vias, aligned magnetic particles, or conductive films at least partially or entirely within the matching layer of each element allow electrical conduction from the transducer material to a ground foil or flex circuit. By using multiple electrical conductive matching layers, a gradation in acoustic impedance for better matching is provided while allowing dicing of the entire stack, including the matching layers and the electroceramic material, in one step.

Abstract: Backing blocks, transducer arrays and methods are provided for thermal cycle survivability. By decoupling a portion of the backing block from a case used to contain the transducer stack, the greater thermal expansion properties of most backing blocks may be minimized. For example, a rim is formed on the backing block material. The rim is bonded to the case structure while other portions of the backing block remain free of bonding to the case structure. During thermal cycling or other temperature changes, the backing block may be less likely to expand or bulge and crack, delaminate or damage transducer elements or other transducer materials.

Abstract: A multi-dimensional transducer array has pitch along one dimension less than the pitch along a second dimension. The multi-dimensional transducer array with the same or different pitch is manufactured from a plurality of modules. Each of the modules are separately diced and then aligned and combined. Elements of a transducer array are used for isolating a transmit channel from a receive channel. Separate signal lines or traces are provided individually for each element on opposite sides of each element. A transmit channel may connect to one electrode on an element, and the receive channel may connect to an opposite electrode on the element. A multi-dimensional array is provided for time division multiplex processing. A probe houses the multi-dimensional array and a multiplexer.

Abstract: Transducer arrays and methods of manufacturing the transducer arrays are provided. A multi-dimensional transducer array is provided where the element-to-element spacing or pitch along one dimension is less than the element spacing or pitch along a second dimension. For example, the element pitch along an azimuth dimension is ½ of the element pitch along an elevation dimension. The multi-dimensional transducer array with the same or different pitch is manufactured from a plurality of modules. Each of the modules are separately diced and then aligned and combined. Separate dicing allows for individual testing of modules prior to assembly as a transducer array. Elements of a transducer array are used for isolating a transmit channel from a receive channel. Rather than a sheet of electrode acting as a ground plane common to a plurality of elements, separate signal lines or traces are provided individually for each element on opposite sides of each element.

Abstract: A system for connecting a transducer array to a coaxial cable. A fanout flex circuit is electrically connected to the coaxial cable, to form one subassembly, and a transducer flex circuit is incorporated into a transducer stack in electrical connection with the transducer array, to form another subassembly. The fanout flex circuit has a row of terminals of first linear pitch at one end and a row of terminals of second linear pitch, less than the first linear pitch, at the other end. The terminals of first linear pitch are electrically connected to the wires of the coaxial cable. The terminals of second linear pitch are electrically connected to a row of free terminals of the same linear pitch on the transducer flex circuit. A layer of pressure-activated conductive adhesive is applied on one row of terminals and then the other row of terminals is pressed against the adhesive-coated row.

Abstract: A method of manufacturing a transducer assembly having a curved transducer array. The method includes the steps of fabricating a laminated assembly by bonding the following layers together: a layer of electrically conductive, acoustic matching material, a layer of piezoelectric ceramic, a flexible printed circuit board and a layer of acoustic damping material. The acoustic damping material changes from an inflexible state to a flexible state when heated. The laminated assembly is then diced to a depth so that the only undiced portion is a portion of the acoustic damping layer. A core body having a curved front face in the shape of a cylindrical section is fabricated. Then at least the undiced portion of the layer of acoustic damping material is heated into a flexible state. The heated undiced portion of the layer of acoustic damping material is flexed to conform to the curved front face of the core body.

Abstract: An ultrasonic transducer having reduced total electrical impedance is constructed by stacking a plurality of piezoelectric transducer element arrays on top of each other. For a given thickness, the electrical impedance of a multilayer stack of piezoelectric transducer element arrays is a function of the number of layers. If the number of layers equals two, then the electrical impedance of the total stack-up of layers is reduced by a factor of one-quarter relative to the electrical impedance of a single layer of equal thickness. This facilitates matching the overall transducer impedance to that of the connecting cable.

Abstract: A compound lens for focusing ultrasound emitted from an ultrasound probe having an array of piezoelectric transducer elements. The compound lens has an inner lens part with a convex cylindrical front face and a rear face which is acoustically coupled to the front face of the transducer array, and an outer lens part with a concave cylindrical rear face which is acoustically coupled to the convex cylindrical front face of the inner lens part. The inner lens part may be in the form of a conventional silicone rubber focusing lens. The outer lens part is made of an acoustic medium having a higher acoustic velocity and greater durability than silicone rubber, e.g., polymethylpentene, nylon and high-density polyethylene. Also the outer lens part has greater chemical resistance than silicone rubber.

Abstract: A device for improving heat dissipation inside an ultrasound probe and reducing heat build-up near the transducer face. Heat conductors are placed around the periphery of the transducer package, but within the probe housing, so that heat can be drawn away from the transducer face and toward the rear/interior of the probe. The heat conductors act as conduits for draining away heat which builds up in the thermal potting material during pulsation of the piezoelectric transducer elements. The heat conductors are formed from metal foil having a heat conductivity greater than the heat conductivity of the thermal potting material which fills the spaces inside the probe housing and surrounds the transducer package. The preferred metal foil is aluminum.

Abstract: A monolithic transducer array case having a bottom wall which is suitable for use as an acoustic impedance matching layer in an ultrasonic transducer. The array case is made from electrically conductive material having an acoustic impedance less than the acoustic impedance of piezoelectric ceramic. The preferred material is copper-impregnated graphite.

Abstract: An adhesion system specifically designed to achieve a good-quality adhesive bond between a silicone rubber lens and a plastic matching layer of an ultrasonic transducer. The adhesion system includes a layer of conventional silicone adhesive applied on the silicone rubber lens and a layer of dichloro-di-p-xylylene residing between the silicone adhesive and the plastic matching layer. The layer of dichloro-di-p-xylylene is adhered to the silicone adhesive via a silicone primer and is adhered to the plastic matching layer via a silane primer. The layer of dichloro-di-p-xylylene provides adhesion promotion, a chemical barrier to protect the transducer array from the external environment and an electrical barrier to help protect the patient from the electrically alive transducer elements, without any adverse effect on the acoustic transmission characteristics of the transducer stack.

Abstract: A one piece layer is provided for protecting the flat surface of a cross-country or telemark ski binding. The layer is a single die-cut self-adherent film to precisely fit the binding plate. The layer is made of a non-stick material such as teflon or polyethylene with one side of the layer made of a high-tack silicone or arcylic adhesive to attach the layer to the binding. The exterior non-stick surface of the layer provides a most effective means for preventing snow and ice buildup on the binding plate and includes a means of covering the heads of the ski binding mounting screws.

Abstract: The present invention is a method and structure which produces extremely thin, electrically conductive epoxy bonds between two substrates. Copper microspheres, having an average diameter of about 2 microns are bound in an epoxy layer which bonds two substrates together. The microspheres make electrical contact between the substrates while providing intersphere gaps which are filled with the epoxy which actually bonds the substrates together.

Abstract: The present invention is a method and structure which produces extremely thin, electrically conductive epoxy bonds between two substrates. Copper microspheres, having an average diameter of about 2 microns are bound in an epoxy layer which bonds two substrates together. The microspheres make electrical contact between the substrates while providing intersphere gaps which are filled with the epoxy which actually bonds the substrates together.