ARRAY STRUCTURE AND INTERCONNECTION FOR TRANSDUCERS - Patent application

Abstract

A method of manufacturing a transducer includes embedding a signal flex and a ground return flex inside a backing block. The method includes forming a stack configuration having a height in elevation and a width perpendicular to the height. The forming includes dicing a piezoelectric layer into rows in elevation and aligning the rows on a backing block to define a beam pattern for the transducer and forming a gap between each piezoelectric layer section and each adjacent aligned piezoelectric layer section. The method includes forming a stack by utilizing a conductive surface of a first matching layer of the one or more matching layers and bonding the one or more matching layers to the piezoelectric layer sections. The method includes forming a cavity in the one or more matching layers in elevation, dicing the stack into a plurality of elements along the elevation direction, and filling the cavity with material.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This PCT international patent application claims priority to U.S. patent application Ser. No. 17 / 561,313, entitled "Array Structure and Interconnect for Transducers," filed on December 23, 2021, the entire contents of which are incorporated by reference herein. [Background technology]

[0002] In conventional ultrasound diagnostic imaging systems, one-dimensional (1D) arrays are used as interfaces to convert electrical signals into ultrasound waves and to convert ultrasound waves received and reflected from tissue structures back into electrical signals. 1D arrays utilize fixed acoustic lenses, such as convex RTV (room temperature curing silicone) lenses, to focus the ultrasound beam in the elevation direction to improve image resolution or image slice thickness. However, the fixed elevation focus in 1D arrays poses challenges to meet clinical requirements for both high resolution and deep penetration depth. Currently, the most common ultrasound transducer in medical imaging is the 1D array, which utilizes a fixed aperture with an acoustic lens in elevation to improve image resolution. The transducer elements can be arranged in linear 1D rows or chains (so-called linear arrays) and can be controlled by an electronic control unit separately or in groups to achieve a directional effect. However, a fixed aperture provides limited flexibility to achieve a uniform and narrow beam pattern (e.g., high resolution and deep penetration depth) from the near field to the far field in elevation for clinical applications. Although the elevation resolution can be improved by using a controlled multi-row array (e.g., 1.25D or 1.5D) for elevation aperture adjustment, the cost of building a multi-row array during manufacturing is high due to the complex electrical interconnections between the rows and columns. The complexity of these connections also opens up the possibility of malfunctions and can affect the life of the device. Furthermore, while the elevation resolution can be improved, current multi-row arrays typically impose the limitation that all rows are of the same center frequency. Summary of the Invention [Means for solving the problem]

[0003] The shortcomings of the prior art can be overcome and the advantages as described below in this disclosure can be achieved by providing a method for manufacturing a transducer. Various examples of the method are described below, and the method, in any combination (unless the combination is inconsistent), including and excluding the additional examples listed below, overcomes these shortcomings. The method includes, for example, embedding a signal flex and a ground return flex inside a backing block. The method also includes forming stack structures, each stack structure having a height at an elevation angle and a width perpendicular to the height. The forming includes dicing the piezoelectric layer into a plurality of rows at an elevation angle of the piezoelectric layer, separating the piezoelectric layer into piezoelectric layer portions. The forming also includes defining a beam pattern for the transducer by aligning the piezoelectric layer portions on the backing block, and defining the beam pattern includes aligning each piezoelectric layer portion at a distance from another piezoelectric layer portion. The forming also includes forming a gap between each piezoelectric layer portion and each adjacent aligned piezoelectric layer portion based on the aligning. The method further includes forming a stack by bonding the one or more matching layers to the piezoelectric layer portion by utilizing a conductive surface of a first matching layer of the one or more matching layers. The method includes forming a cavity in the one or more matching layers. The method includes dicing the stack into a plurality of elements along an elevation direction. The method includes filling the cavity with a material.

[0004] The shortcomings of existing transducers can be overcome and advantages as described later in this disclosure can be achieved by providing a transducer as described herein. Various examples of this transducer are described below, and the transducer overcomes these shortcomings in any combination (unless the combination is inconsistent), including and excluding the additional examples listed below. The transducer may include a lens, a signal flex and a ground return flex inside a backing block, and a stack configuration aligned on the backing block. Each of the stack configurations includes a piezoelectric layer and one or more matching layers. A gap is formed at an elevation angle between each piezoelectric layer and each adjacent aligned piezoelectric layer. Each stack configuration has a height at an elevation angle, a width perpendicular to the height, and a stack thickness configuration. The stack thickness configuration is perpendicular to the height and perpendicular to the width. The one or more matching layers are coupled to the lens and bonded to each piezoelectric layer. A conductive surface of one of the one or more matching layers is bonded to a top surface of each piezoelectric layer. The one or more matching layers include one or more cavities. The cavity is filled with a material. Some examples include a dematching layer on the back side of the piezoelectric layer.

[0005] The shortcomings of existing transducers can be overcome and the advantages as described later in this disclosure can be achieved by providing a transducer as described herein. Various examples of this transducer are described below, and the transducer overcomes these shortcomings in any combination (unless the combination is inconsistent), including and excluding the additional examples listed below. The transducer may include a lens, a signal flex and a ground return flex inside a backing block, and a stack configuration aligned on the backing block. Each stack configuration of the stack configuration is aligned on the backing block with at least two outer rows and a center row. The center row generates a first frequency signal and the at least two outer rows generate a second frequency signal. The frequency of the first frequency signal is not equal to the frequency of the second frequency signal. Each of the stack configurations includes a piezoelectric layer and one or more matching layers coupled to the lens and bonded to each piezoelectric layer. A gap is formed at an elevation angle between each piezoelectric layer and each adjacent aligned piezoelectric layer. A conductive surface of one of the one or more matching layers is bonded to a top surface of each piezoelectric layer. The one or more matching layers include one or more cavities. The cavities are filled with a material. Some examples include a dematching layer on a back surface of the piezoelectric layer.

[0006] Additional features are realized by the devices and techniques described herein. Other embodiments and aspects are described in detail herein and are considered a part of the claimed aspects.

[0007] One or more aspects are particularly pointed out and distinctly claimed as examples in the claims at the end of this specification. The foregoing and objects, features, and advantages of the one or more aspects will become apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1] 1A-1C illustrate various aspects of a transducer in some embodiments of the present invention. [Diagram 2]1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Diagram 3] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Figure 4] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Diagram 5] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 6] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 7] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Figure 8] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Figure 9] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Figure 10] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Figure 11] 1A-1D are cross-sectional elevational views of various aspects of a transducer in some embodiments of the present invention. [Figure 12] 11 is a plot illustrating the effect of different gap or kerf sizes in transducers manufactured in accordance with various aspects of some embodiments of the present invention. [Figure 13] 11 is a plot illustrating the effect of different gap or kerf sizes and row widths in transducers manufactured in accordance with various aspects of some embodiments of the present invention. [Figure 14] 1 is a frequency chart illustrating various aspects of some embodiments of the present invention. [Figure 15] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 16] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 17] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 18] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 19] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. [Figure 20] 1A-1D illustrate operational steps for manufacturing a transducer according to some aspects of some embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The accompanying drawings, which are not drawn to scale for ease of understanding and in which like reference numbers may refer to identical or functionally similar elements throughout the different views, are incorporated in and form a part of this specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention. As will be understood by one of ordinary skill in the art, the accompanying drawings are provided for ease of understanding and illustrate aspects of certain embodiments of the present invention. The present invention is not limited to the embodiments shown in the drawings.

[0010] Examples of terms The terms "connect," "connected," "contact," "coupled," and the like are broadly defined herein to encompass a wide variety of configurations and assembly techniques, including, but not limited to, (1) a direct coupling of one component to another component with no intervening components therebetween (i.e., the components are in direct physical contact with each other), and (2) a coupling of one component to another component with one or more components therebetween, provided that a component that is "connected" or "in contact" or "coupled" to another component is in some manner of operative communication (e.g., electrically, fluidly, physically, optically, etc.) with the other component (despite the presence of one or more additional components therebetween). It should be understood that some components that are in direct physical contact with each other may or may not be in electrical contact and / or fluid contact with each other. Additionally, two components that are electrically connected, electrically coupled, optically connected, optically coupled, fluidly connected, or fluidly coupled may or may not be in direct physical contact, and one or more other components may be positioned between them.

[0011] As used herein, the terms "including" and "comprising" mean the same thing.

[0012] The terms "substantially", "approximately", "about", "relatively", or other such similar terms, which may be used throughout this disclosure, including the claims, are used to describe and explain small variations, such as those due to variations in processing, from a reference or parameter. Such small variations also include zero variation from a reference or parameter. For example, they can refer to ±10% or less, such as ±5% or less, such as ±2% or less, such as ±1% or less, such as ±0.5% or less, such as ±0.2% or less, such as ±0.1% or less, such as ±0.05% or less. As used herein, the terms "substantially", "approximately", "about", "relatively", or other such similar terms, can also refer to no variation.

[0013] As used herein, "electrically coupled" refers to the transfer of electrical energy between any combination of power sources, electrodes, conductive surfaces, droplets, conductive traces, wires, waveguides, nanostructures, other circuit segments, etc. The term electrically coupled may be utilized in connection with direct or indirect connections, and may pass through various intermediaries, such as fluid intermediaries, air gaps, etc.

[0014] As used herein, "azimuth" is an angular measurement in a spherical coordinate system. When a vector from an observer to a point of interest is projected perpendicularly onto a reference plane, the angle between the projected vector and a reference vector on the reference plane is called the azimuth. In ultrasound imaging, the subject matter discussed herein, the term "azimuth" is also called lateral. When defining a coordinate system with respect to an ultrasound imaging plane, the terms axial or radial refer to depth along the ultrasound beam, the terms lateral or azimuth refer to in-plane angles or distances (i.e. across the beam), and the elevation angle refers to out-of-plane distances or angles.

[0015] As used herein, the term "Kerf" refers to an adjustable gap between diced portions of the acoustic surface that is filled in each instance with varying material (to maintain and adjust the gap).

[0016] Different transducer approaches are considered herein and are referred to as 1D arrays, 1.25D arrays, 1.5D arrays, 1.75D arrays, and 2D arrays. The "D" in each case represents the word "dimension." As used herein, in a 1D transducer approach, the elevation aperture is fixed and focused to a fixed range. In a 1.25D transducer approach, the elevation aperture is variable, but the focusing remains static. In a 1.5D transducer approach, the elevation aperture, shading, and focusing are dynamically variable, but symmetric about the centerline of the array. Conversely, a 1.75D array is a 1.5D array without symmetry constraints. Thus, the elements are large in elevation (e.g., several wavelengths), so little steering is possible. In a 2D transducer array, the elevation geometry and performance are comparable to the azimuth, with full electronic apodization, focusing, and steering.

[0017] The term "ROC" refers to the radius of curvature and is used herein in the context of acoustic design. In medical ultrasound arrays, ROC lenses are generally cylindrical focus lenses. Lenses referred to herein as ROC lenses are single radius focus lenses, and lenses referred to herein as multi-ROC lenses are multiple radius focus lenses. The ROC of a convex acoustic lens is the product of the geometric focal length and the lesser of the speed of sound in the medium divided by the speed of sound in the lens material. Acoustic lenses used herein are designed based on paraxial theory or the Fresnel approximation in geometric optics, assuming a plane wavefront emitted in a direction normal to the transducer surface.

[0018] As used herein, the term "PZT" refers to lead zirconate titanate or lead zirconium titanate, a ceramic perovskite material that exhibits the piezoelectric effect, i.e., the compound changes shape when an electric field is applied. In this context, it is utilized in ultrasonic transducers. PZT ceramics are the most commonly used piezoelectric ceramics due to their higher sensitivity and higher operating temperature than other piezoelectric ceramics. As used herein, the term "SX" used in conjunction with "PZT" as "PZT / SX" refers to a single crystal lead zirconate titanate or lead zirconium titanate layer.

[0019] As used herein, the term "DML" refers to a dematching layer, which is a material that typically has a higher acoustic impedance than the piezoelectric material used in the transducer, although in some cases lower acoustic impedance materials can also be used as the DML. Tungsten carbide (WC) or tungsten (W) is most commonly used as the DML material because it is electrically conductive and has an acoustic impedance of about 100 MRayl compared to the acoustic impedance of piezoelectric materials (PZT or SX) which range from 20 MRayl to 35 MRayl.

[0020] As used herein, the terms "signal flex" and "ground return flex" refer to the signal and ground return elements in flexible electronics, also known as flex circuits, which are circuits that conform to a desired shape (e.g., flex during use). Flex circuits are utilized as connectors in a variety of applications where flexibility, space savings, and / or manufacturing constraints limit the usefulness of rigid circuit boards or hand wiring. Many flexible circuits are passive wiring structures used to interconnect electronic components.

[0021] As used herein, the term "stripper" refers to a separate portion of an element. For example, a specific example herein involves dicing a piezoelectric layer into a stripper.

[0022] As used herein, the term "stack configuration," in the context of the examples herein, refers to a stack of objects, referred to herein as a "stack," that includes pieces of piezoelectric layers diced into multiple rows in elevation, and possibly matching and dematching layers. As described herein, each stack configuration is described with respect to three dimensions: height in elevation, width perpendicular to the height, and stack thickness configuration perpendicular to the height and perpendicular to the width.

[0023] As used herein, the term "beam pattern" (which may also be called acoustic radiation pattern) is the relative sensitivity of a transducer as a function of spatial angle. This pattern is determined by factors such as the frequency of operation and the size, shape and acoustic phase characteristics of the vibrating surface. The beam pattern of a transducer is reciprocal, meaning that the beam will be the same whether the transducer is used as a transmitter or a receiver. In general, transducers can be designed to radiate sound in many different types of patterns, from omnidirectional to very narrow beams.

[0024] Embodiments of the present invention include multiple rows or multi-row transducers and methods for constructing these multi-row transducers. Some embodiments of the present invention combine multi-frequency and multi-row (multi-dimensional) characteristics to improve image quality, including both resolution and transparency, address the needs of multiple clinical functions, and enable portability by utilizing only one transducer.

[0025] Examples of the invention include high performance transducers that significantly expand the frequency range and improve the elevation beam pattern. The wider range and elevation beam pattern in embodiments of the invention can be achieved utilizing only one transducer. Both the method and the transducer itself meet various clinical needs. As described in more detail herein, examples of the invention include, but are not limited to, methods for fabricating multi-dimensional (e.g., 1.25D, 1.5D, 1.75D and 2D) and multi-frequency arrays with low design and manufacturing costs, as well as the manufactured transducers themselves. Examples of the invention provide advantages over existing ultrasound applications, including, but not limited to: 1) extending current array construction concepts and solderless interconnect manufacturing techniques to multi-dimensional and multi-frequency array configurations (e.g., expanding the frequency range) to improve elevation beam profiles and significantly expand the frequency range of the transducer, and / or 2) improving imaging resolution, penetration, and overall image quality by enhancing the elevation beam pattern in both the near and far fields using a single transducer. As described herein, the disclosed manufacturing methods and resulting transducers may vary in design according to their intended clinical application but include the advantages discussed above, such as: 1) gap and row width values ​​can be adjusted to suit different applications, and / or 2) multi-ROC focus options of the lens can be utilized to further modify and tune the elevation beam profile characteristics (e.g., elevation beam width) from the near field through the transition region to the far field.

[0026] Certain advantages of the examples herein are achieved based on design flexibility. For example, the examples described herein can be utilized in 1.25D arrays as well as 1.5D, 1.75D, and 2D arrays. As described in more detail herein, these different arrays can include center and outer rows with different stack configurations, different materials, and / or different thicknesses to generate different frequency signals. In some examples herein, the arrays include a combination of gap size and row width adjustment to provide improved elevation beam patterns. In some examples, the gap between rows in elevation can be widened to several wavelengths to provide greater manufacturing flexibility. The adjustable gap can be filled with a backing material or other material. The transducers described herein can include various numbers of matching layers (e.g., the center and outer rows can utilize different numbers of matching layers) and can include or exclude a conductive de-matching layer (DML) (e.g., the center and outer rows can utilize different configurations). In ultrasound applications, the matching layer provides an acoustic impedance gradient for acoustic energy from the transducer to penetrate smoothly through body tissue and for reflected acoustic waves (e.g., return echoes) to return smoothly to the transducer for detection. The matching layer can be positioned between the acoustic element (e.g., piezoelectric layer) and the lens (e.g., single-radius focal lens and / or multiple-radius focal lens). The matching layer can include materials (e.g., epoxy, polyurethane, polystyrene, graphite, composites of tungsten powder mixed with epoxy, etc.) that help achieve better energy transfer. For example, these materials can be selected and constructed together to achieve better energy transfer than each material can achieve individually. Generally, ultrasound probes include at least one matching layer, but some include two or three matching layers. Meanwhile, the conductive DML (e.g., tungsten carbide (WC), etc.) has an acoustic impedance that is greater than the acoustic impedance of the active acoustic layer, e.g., a piezoelectric layer such as a piezoelectric ceramic (e.g., PZT / SX).The thickness of the DML can be varied to change the bandwidth of the transducer. Examples herein can also include either a single ROC focusing lens or a multi-ROC focusing lens.

[0027] The figures herein described individually include figures providing examples of transducers that can be utilized for ultrasonic purposes, and figures showing example work steps illustrating aspects of manufacturing these transducers. In some examples, certain aspects of the process described in the work steps can be performed, at least in part, by a combination of one or more of the following equipment: tooling devices, composite plates, tooling surfaces, vacuum pumps, guiding devices (e.g., guide rings or annuli), CNC (computer numerical control) machines, clean areas, workstations for micro-precision transducer assembly, fume hood stations, and / or calibrated ovens. The work steps described herein can incorporate one or more of enhanced surface area adhesion, passivation and cleaning of rough surfaces, and / or plasma etching. Figures 1-14 show various aspects of methods of manufacturing multi-dimensional and multi-frequency arrays for transducers and the resulting transducers. Figures 1-4 and 7-11 show various transducers manufactured according to various aspects of the methods disclosed herein. Meanwhile, Figures 5 and 6 illustrate the process steps utilized to manufacture the transducers shown in Figures 1-4 and 7-11. Figures 12-14 demonstrate advantages associated with the functionality of certain transducers disclosed herein. Figures 15-18 also illustrate examples of various process steps for manufacturing transducers according to various aspects of the method disclosed herein.

[0028] FIG. 1 shows a top view of a multi-row / multi-frequency transducer array 100. Azimuth 110 and elevation 120 angles are shown. Although there are three rows in this example, this is not provided as a limitation and is merely for illustrative purposes. Thus, transducers of a given frequency are placed in the outer rows 130 of the array 100 and transducers of a different frequency are placed in the center row 140 of the array 100. Elements of the array in FIG. 1 are referenced throughout to illustrate various elements of the examples disclosed herein.

[0029] As discussed above, examples herein include transducer array structures including multi-dimensional configurations in which the center row (e.g., FIG. 1, 140) and outer rows (e.g., FIG. 1, 130) have a common stack. FIGS. 2-4 show examples in which an elevational view of the array structure and interconnection scheme for a multi-dimensional configuration in each transducer 200, 300, 400 includes this aspect. In these examples, the electrical signals connecting each row are embedded inside the backing block. The ground wires are also embedded inside the backing stripper. Thus, as described in more detail below, the grounds from these multiple rows are connected via a conductive matching layer or a matching layer with a conductive surface, or an electrode. The matching layer has an electrode on the inner (acoustic) surface (facing the piezoelectric material). Despite some differences discussed herein, the multi-row transducers 200, 300, 400 of FIGS. 2-4 have some commonalities. In each example, the illustrated configuration can be utilized in arrays of various dimensions, including 1.25D arrays, 1.5D arrays, 1.75D arrays, and 2D arrays. There are adjustable gaps (also called kerfs) between the diced portions of the acoustic surface that are filled in each example with varying materials. The beam pattern of the transducers 200, 300, 400 can be adjusted by varying one or more of the gap size and row width. Although each example shows three matching layers, any number of matching layers can be utilized. Additionally or alternatively, a conductive DML can be present as desired. Finally, the examples can include different lenses, including but not limited to monofocal ROC lenses and multifocal ROC lenses (also called single radius focus lenses and multiple radius focus lenses, respectively).

[0030] FIG. 2 shows an elevational cross-sectional view of a multi-row transducer 200. The transducer 200 is an example of a 1.25D transducer, fabricated according to the methods described herein. The 1.25D transducer array is shown herein as a non-limiting example, as various embodiments of the invention may also include 1.5D, 1.75D, and 2.0D transducer arrays. However, the 1.25D example is provided for illustrative purposes. The transducer 200 includes a backing block 220, shown here as U-shaped. Two grounds 210a and 210b are embedded in the shoulder stripper portion of the machined U-shaped backing block 220. In some embodiments of the invention, electrode sputtering is performed on the top surface. Electrical signals 230a-c embedded in the bottom of the backing block 220 define the locations for the multi-row connections. Gaps 295 are formed by dicing through piezoelectric layer 240 and DMLs 250 to backing block 220. Conductive DMLs 255a-c electrically connect the backside of piezoelectric layers 245a-c to signals 230a-c using solderless connections. Piezoelectric layer 240 at elevation (e.g., FIG. 1, 110) is diced into a plurality of rows 245a-c (as discussed in the following steps, including but not limited to step 500 of FIG. 1). Gaps 295 are filled with material (e.g., air, microballoons, and / or high acoustic attenuation material, room temperature curing silicone, backing material, and / or material mixed with microballoons).

[0031] The multi-row transducer 200 also includes three matching layers 260, 265, 270, with the first matching layer 260 including a conductive surface that includes the electrode 261. In some examples, the electrode 261 is electrically connected to the two grounds 210a and 210b using a solderless connection. In some examples, the gaps 296a and 296b where the matching layer is removed by dicing that align with the dicing kerfs 295 are filled with a material (e.g., air, microballoons, lens material). The gaps 296a and 296b are shown in FIG. 1 as gaps 170. The gaps 296a and 296b where the dicing depth does not cut through the first matching layer 260 include a conductive surface that includes the electrode 261. The transducer 200 also includes a piezoelectric layer (e.g., PZT / SX) 240 below the conductive surface that includes the electrode 261. The front electrodes of the multiple rows of piezoelectric portions 240 are connected to one another through a conductive surface 261 of a first matching layer 260 at a buried ground return 210. The matching layers 260, 265, 270 are positioned between the piezoelectric layer 240 (e.g., an acoustic layer) and a lens 280. The lens 280 shown in Figure 2 is a single ROC focusing lens, although other examples can include a multi-ROC focusing lens.

[0032] In some examples, the piezoelectric layer 240, DML 250 and matching layers 260, 265, 270 are further diced together in azimuth (i.e., along the elevation direction) into multiple rows within the backing block 220 to further separate the piezoelectric material into separate portions or elements to form a multi-dimensional array (e.g., multiple rows where the kerfs 160 in FIG. 1 separate the piezoelectric material into separate portions or strippers). With reference to FIG. 1, the kerfs 160 or azimuth gaps created by this dicing are visible in FIG. 1 because FIG. 1 shows a top view of a multi-dimensional array of an embodiment of the invention. Meanwhile, the elevation gaps (gaps 170), also created by dicing, are shown in both FIG. 1 and FIG. 2 because this aspect is visible both from the top view (FIG. 1) and in the elevation cross-section view (FIG. 2). 1 and 2, the matching layer, piezoelectric layer 240, DML 250, and backing block 220 are removed by the dicing and kerfs 160 are filled with material (e.g., air, microballoons, lens material). In this example, the DML 250 is bonded to the acoustic layer, i.e., piezoelectric layer 240. The piezoelectric layer 240 and DML 250 in elevation (e.g., FIG. 1, 110) were diced (as discussed in the following steps, including but not limited to step 500 of FIG. 1) into a number of rows 245a-245c and 255a-255c. The DML 250 also includes electrodes 271.

[0033] Similar to the transducer 200 of FIG. 2, FIG. 3 also shows a non-limiting example of an elevational cross-section of a 1.25D transducer 300 assembled according to the methods described herein. The transducer 300 of FIG. 3 also includes a backing block 320 (e.g., three U-shaped blocks), but unlike FIG. 2, the backing block 320 is machined into three U-shaped through-block sections. The grounds 310a and 310b are embedded in the two outermost machined backing shoulder strippers, respectively. Electrical signals 330a-330c at the bottom of the backing block 320 define the locations for the multi-row connections. Similar to the transducer 200 of FIG. 2, the multi-row transducer 300 of FIG. 3 also includes three matching layers 360, 365, 370. The first matching layer 360 includes a conductive surface including an electrode 361. However, unlike FIG. 2 where the DML 250 and piezoelectric layer 240 of transducer 200 are diced and gaps 295 are formed after bonding the DML 250 and piezoelectric layer 240 with embedded electrodes 230, in FIG. 3 the conductive DML 350 and piezoelectric layer 340 are diced into 355a-355c and 340a-340c, respectively, and the gaps are machined into U-shaped feedthrough block sections from backing block 320. The DML 350 and piezoelectric layer 340 are then bonded. The conductive DMLs 355a-355c electrically connect the backside of piezoelectric layers 345a-345c to signals 330a-330c using solderless bond connections. In this non-limiting example, three U-shaped feedthrough block sections are machined into backing block 320. A piezoelectric layer (e.g., PZT / SX) 340 is bonded to a conductive surface (e.g., electrode 361) of the first matching layer 360, which connects the front electrodes of the rows of piezoelectric portions 340 with a buried ground return 310 via the conductive surface 361 of the first matching layer 360. The matching layers 360, 365, 370 are positioned between the piezoelectric layer 340 (acoustic layer) and a lens 380 (e.g., single ROC focus lens, multi-ROC focus lens), and the DML 350 is coupled to the piezoelectric layer 340.The elevation gaps 396a and 396b (where the matching layer was removed) and the azimuthal gaps (created by subsequent azimuthal dicing after the elevation dicing of the matching layer) are filled with material (e.g., air, microballoons, and / or high acoustic attenuation material, room temperature curing silicone, backing material, lens material, and / or material mixed with microballoons).

[0034] FIG. 4 shows an example of an elevational cross-section of a multi-row transducer 400 assembled according to various aspects of the methods described herein. This example can be multi-dimensional (e.g., 1.25D, 1.5D, 1.75D, 2D). The backing block 420 shown here is machined into three U-shaped through block sections with four embedded grounds 410a-410d. The four embedded grounds 410a-410d and three electrical signals 430a-430c at the bottom of the block 420 define the locations for the multi-row connections. The four grounds 410a-410d can be connected to each other outside of the backing block 420. This multi-row transducer 400 also includes three matching layers 460, 465, 470 positioned between the piezoelectric layer 440 (acoustic layer) and the lens 480. The first matching layer 460 includes a conductive surface that includes an electrode 461. As in FIG. 3, in transducer 400 of FIG. 4, piezoelectric layer (e.g., PZT / SX) 440 and conductive DML 450 under the conductive surface are diced together into three pieces before being placed into a machined U-shaped slot in a backing block. Conductive DMLs 455a-455c, including electrodes 471, electrically connect the backside of piezoelectric layers 445a-445c to signals 430a-430c. Unlike in FIGS. 2 and 3, the elevation dicing of the three matching layers (to create gaps 496a and 496b) completely cuts through the conductive surface, as shown in FIG. 4. The elevation gaps 496a and 496b (where the matching layers were removed) as well as the azimuthal gaps (created by subsequent azimuthal dicing after the elevation dicing of the matching layers) are filled with material (e.g., air, microballoons, lens material).

[0035] Figures 5 and 6 show process steps 500, 600, respectively, illustrating the assembly of the multi-row transducers 200, 300 of Figures 2 and 3, and the multi-row transducer 400 of Figure 4. When process step 500 is described, reference is made for illustrative purposes to various aspects of the transducers 200, 300 of Figures 2 and 3. When process step 600 of Figure 6 is described, reference is made for illustrative purposes to various aspects of the transducer 400 of Figure 4.

[0036] Referring to the process 500 of FIG. 5 and the multi-row transducer 200, 300, in the process 500, an individual and / or machine embeds (510) two grounds 210a and 210b, 310a and 310b in the backing block 220, 320. In some examples, the process includes embedding the grounds and electrical signals in a cast backing block. The block can also be machined into one or more U-shaped slots, exposing the ground lead at the top of the backing block and the electrical signal at the bottom. As previously mentioned, the backing block can include one or more U-shaped slots. In the example of a U-shaped block, the two grounds 210a and 210b, 310a and 310b are embedded near the elevation edge of the block, exposing the top lead of the U-shape of the backing block 220, 320. Thus, the signals 230a-230c, 330a-330c are at the bottom of the U-shape and define the locations for the multi-row connections. The individual and / or machine performing the work process bonds the piezoelectric layer (e.g., PZT / SX) 240 to the backing block 220 either directly (520) or via the conductive DML 250. In some examples, the piezoelectric layer can be bonded to the backing block in each U-shaped slot described above. Examples of materials for bonding the piezoelectric layer 240 to the backing block 220 include, but are not limited to, epoxy resin, or epoxy resin with metal particles (e.g., conductive epoxy). The individual and / or machine performing the work process dices (530) the piezoelectric layer 240 into multiple rows 245a-245c at an elevation angle (e.g., FIG. 1, 110) and separates the piezoelectric layer 240 into separate pieces or strippers (e.g., multiple rows). For example, if more rows are utilized, the piezoelectric layer can be diced into multiple rows at an elevation angle. This dicing creates gaps that can be filled with different materials in various embodiments of the invention to maintain the gaps. In FIG. 2, this dicing creates gaps between multiple rows 245a-245c (stripper). Some examples of this method include filling the gaps with air, microballoons, and / or lens material 295.In FIG. 3, unlike FIG. 2, the piezoelectric layer 340 is bonded to the backing block 320 after it is diced, rather than before it is diced. In some examples, three U-shaped slots with gaps defined between the slots are machined into the backing material to accommodate the strippers 345a-345c. Thus, in FIG. 3, a machine and / or individual places the strippers 345a-345c into the slots. In some examples, the gap between the slots is selected to be zero, and thus only one U-shaped slot is machined into the backing material to accommodate the strippers 345a-345c. In other examples, additional kerf fill material can be utilized where the material is adapted to substantially fill the kerfs between adjacent transducer elements.

[0037] Returning to FIG. 5, a machine and / or individual bonds (540) the piezoelectric layer 240, 340 to one or more matching layers 260, 360. In some examples, the machine and / or individual places the diced portions (strippers, portions) 245a-245c, 345a-345c of the piezoelectric layer 240, 340 into machined slots in the backing block 220, 320 and then bonds to the matching layer 260, 360. In the example of FIG. 2 and FIG. 3, three matching layers are shown: a first matching layer 260, 360, a second matching layer 265, 365, and a third matching layer 270, 370. However, this number of matching layers is provided only as an example of a possible configuration in some embodiments of the present invention and is not meant to imply a limitation. As discussed above, ultrasonic probes generally include at least one matching layer to achieve better energy transfer than probes without one or more matching layers. A machine and / or person couples (540) the matching layer to the piezoelectric layer 240, 340 by electrical bonding since the first matching layer 260, 360 is conductive or has electrodes 261, 361 on its inner surface. Thus, the process 500 includes connecting the layers (in this example, the first matching layer 260, 360, the second matching layer 265, 365, and the third matching layer 270, 370) to each other. The machine and / or person can connect the ground of each row through the conductive surface of the first matching layer 260, 360. Without cutting the conductive electrodes 261, 361 on the surface of the first matching layer 260, 360, an individual and / or machine dices the matching layers (e.g., the first matching layer 260, 360, the second matching layer 265, 365, and the third matching layer 270, 370) along multiple row directions (in elevation) to remove (550) a portion of the first matching layer 260. Thus, after this elevation dicing of the matching layers, an individual and / or machine further dices (550) the transducer into multiple columns in azimuth (previously called azimuth dicing) to further separate the stack into separate portions or elements to form the final multidimensional array.An individual and / or machine fills (560) the elevation gaps 296a-b, 396a-b (where the matching layers were removed) and the azimuthal gaps (created by azimuthal dicing) with a material (e.g., air, microballoons, lens material).

[0038] Referring to operation 600 of FIG. 6, in this example, the method includes embedding (610) a ground (e.g., multiple) and electrical signals into the backing block 420. In some examples, (an individual and / or a machine) embeds multiple grounds and electrical signals into a cast backing block. The block is machined into one or more U-shaped slots, exposing the ground lead at the top of the backing block and the electrical signals at the bottom. In this example, four grounds and three electrical signals are embedded into the backing block 420. The backing block 420 is machined into three U-shaped sections such that the grounds form the four tops of the U while the three signals 430a-c are at the bottom of the U with defined locations for multi-row connections. The piezoelectric layer 440 is diced (620) into multiple rows 445a-c at an elevation angle (e.g., FIG. 1, 120) to separate the piezoelectric layer 440 into separate pieces or strippers (e.g., multiple rows). The stripper is placed (630) into a machined slot in the backing block 420.

[0039] An individual and / or machine bonds (640) one or more matching layers (e.g., first matching layer 460, second matching layer 465, third matching layer 470), including bonding first matching layer 460 having conductive surface 461 to portions (stripper) 445a-445c of piezoelectric layer 440. An individual and / or machine dices (650) one or more matching layers in elevation so that they are all completely cut off to improve acoustic and electrical isolation and therefore angular response per row. In some examples, one or more matching layers can be completely diced in elevation while keeping the ground leads and electrical signals in a U-shape. After this elevation dicing of the matching layers, an individual and / or machine dices (660) the transducer into multiple columns in azimuth to further separate the stack into separate portions or elements to form a multi-dimensional array. An individual and / or machine fills (670) the elevation gaps 496a and 496b (where the matching layer was removed (650)) and the azimuthal kerfs (created by subsequent azimuthal dicing (660)) with material (e.g., air, microballoons, lens material).

[0040] 7-9 are examples of multi-row transducers 700, 800, 900 shown in a multi-frequency transducer configuration. The multiple dimensions combined with the multiple frequency aspect improve image quality (e.g., resolution and penetration) and also benefit ultra-portable applications by providing multiple clinical functions with a single transducer. In contrast, multiple conventional ultrasound probes may be required to accommodate multiple clinical functions, one conventional ultrasound probe for each clinical function, which may delay patient care if the clinician does not have a conventional ultrasound probe suitable for a particular clinical procedure.

[0041] As with the previous examples, the array of multi-row transducers 700, 800, 900 can have a variety of dimensions, such as 1.25D, 1.5D, 1.75D, and 2D. As shown and described in more detail, the center row and outer rows can have different stack configurations, materials, and / or thicknesses, so that the frequency of the signal varies in these examples. Specifically, in these examples, the outer rows (e.g., FIG. 1, 130) have slightly thicker stacks to generate lower frequency signals than thinner stacks would generate. As with the examples of FIGS. 2-4, the multi-row transducers 700, 800, 900 of FIGS. 7-9 include adjustable gaps filled with a backing material or other material. The combination of gap size and row width adjustment provides a variety of beam patterns. The number of matching layers can vary in these examples, and the center row (e.g., FIG. 1, 140) and outer rows (e.g., FIG. 1, 130) can have different numbers of matching layers. DMLs are optionally present, but in these examples, whether or not the DMLs are part of the configuration may vary between the center row (e.g., FIG. 1, 140) and the outer rows (e.g., FIG. 1, 130). Because the center and outer rows of transducers 700, 800, 900 of FIGS. 7-9 produce different frequencies, the configuration of these portions may vary, in contrast to transducers 200-400 of FIGS. 2-4, where there was a consistent frequency and therefore a consistent configuration between the outer and center rows.

[0042] As mentioned above, Figures 7-9 show examples of transducer structures 700, 800, 900. These figures provide elevational cross-sectional views of array structures and interconnection schemes for these multi-dimensional and multi-frequency transducer configurations, with each example having a central row 715, 815, 915 and outer rows 716a and 716b, 816a and 816b, 916a and 916b having different stacks of piezoelectric (acoustic) layers 741, 742, 841, 842, 941, 942, and optionally one or more matching layers, and / or with or without dematching layers 751, 752, 851, 852, 951, 952. The assembly process for these configurations includes certain aspects of operations 500 and 600 of Figures 5 and 6, respectively.

[0043] Referring to FIG. 7, a multi-row and multi-frequency transducer 700 includes a backing block 720, shown here as a U-shape, into which two grounds 710a and 710b are embedded and machined to expose the top leads. Electrical signals 730a-730c at the bottom of the block 720 define the locations for the multi-row connections. In this example, the center row 715 and the outer rows 716 are configured differently. In some examples, the backing under the DMLs 751 and 752 are machined at different heights. In the example shown, both the piezoelectric material and the DML material in the center 742, 752 have different heights than the outer piezoelectric material and DMLs 741, 751. However, the total height of the layer combination and the height of the machined backing are the same. Thus, unlike FIGS. 2-4, the stack does not have to be formed by dicing the piezoelectric layers. Alternatively, the outer rows 716a and 716b may include portions of a single diced piezoelectric layer 741, while the center row 715 may utilize a different piezoelectric layer 742. The thickness and presence of conductive DMLs may also vary between the center row 715 and the outer rows 716a and 716b. Thus, in FIG. 7, the outer row DML 751 and the inner row DML 752 are shown separately. Each DML 751, 752 is conductive and includes an electrode 771. The transducer 700 includes three matching layers 760, 765, 770, with the first matching layer 760 including a conductive surface that includes the electrode 761. The matching layers 760, 765, 770 are positioned between the piezoelectric layers 741, 742 (acoustic layers) and a lens 780. The illustrated lens 780 is a single ROC focusing lens, but other examples may include a multi-ROC focusing lens. Gaps 795 between each outer row 716a and 716b and the central row 715 are filled with a material that may include, but is not limited to, air or microballoons.

[0044] The transducer 800 of FIG. 8 is similar to the example of FIG. 7, but the gaps between each outer row 816a and 816b and the central row 815 are machined out of the material of the backing block 820. Thus, an assembly process like that of FIG. 6 can be utilized, with a stack or stripper plugged into the backing block 820. FIG. 8 is a non-limiting example of a 1.25D transducer 800. The transducer 800 includes a backing block 820 (e.g., three U-shaped blocks) into which two grounds 810a and 810b are embedded and machined. Electrical signals 830a-830c at the bottom of the block 820 define the locations for the multi-row connections. This transducer 800 includes three matching layers 860, 865, 870, with the first matching layer 860 including a conductive surface including an electrode 861. Bonded to the conductive surface (e.g., electrode 861) of the first matching layer 860 is a piezoelectric layer (e.g., PZT / SX) 840. Matching layers 860, 865, 870 are positioned between piezoelectric layers 841, 842 (acoustic layers) and a lens 880 (e.g., single ROC focus lens, multi ROC focus lens). DMLs 851, 852 may also be bonded to the other side (e.g., backside) of piezoelectric layers 841, 842. Each DML 851, 852 is conductive and includes an electrode 871.

[0045] The assembly process of FIG. 6 can also be utilized to assemble the transducer 900 of FIG. 9. Examples of this can be 1.25D arrays, 1.5D arrays, 1.75D arrays, and / or 2D arrays. A backing block 920, shown here as a U-shape, is machined with four glands 910a-910d embedded inside. Three electrical signals 930a-930c at the bottom of the block 920 define the locations for the multi-row connections. This multi-row transducer 900 also includes three matching layers 960, 965, 970 positioned between the piezoelectric layers 942, 941 (acoustic layers) and the lens 980. The first matching layer 960 includes a conductive surface that includes an electrode 961. The transducer 900 also includes outer rows 916a and 916b and a center row 915 with different acoustic stacks of different thicknesses. Each DML 951 , 952 is conductive and includes an electrode 971 .

[0046] In Figures 7-9, the center rows 715, 815, 915 and the outer rows 716a and 716b, 816a and 816b, 916a and 916b may generate slightly different frequency signals. CenterRow ~Frequency_ OuterRow , for example Frequency_ CenterRow Frequency_ OuterRow In such a case, substantially the same matching layer structure can be maintained.

[0047] The center row and the outer rows are very different frequency signals (e.g., Frequency_CenterRow~2 *In some examples where a matching layer stack thickness (center row vs. outer rows) may be generated, the thickness of the matching layer stack (center row vs. outer rows) may need to be different in addition to the different piezoelectric layer thicknesses and the thickness of the DML (if the configuration includes a DML) to achieve improved acoustic performance (such as wider bandwidth and higher sensitivity). FIGS. 10 and 11 show such different transducer configurations 1000, 1100 as described above. In FIGS. 10 and 11, the center rows 1015, 1115 and the outer rows 1016a and 1016b, 1116a and 1116b may generate different frequency signals (e.g., Frequency_CenterRow~2). * In Figure 10, both the center row 1015 and the outer rows 1016a, 1016b utilize a conductive DML 1050 (including electrode 1071), while in Figure 11, the center row 1115 is configured without a DML, and the outer rows 1116a and 1116b include a DML 1150 that includes electrode 1171. Both configurations include stacks of different thicknesses.

[0048] When constructing a transducer using methods described herein, including those in steps 500, 600 of Figures 5 and 6, both the elevation gap width (the distance between stacks in elevation) and the elevation row width (the elevation width of the stacks themselves) can be adjusted to suit the requirements of the resulting transducer. Additionally, the multi-ROC focus option of the lens can be utilized to further modify and adjust the elevation beam profile or width from the near field through the transition region to the far field. The elevation gap size and row width independently affect the beam pattern of a transducer comprising the embodiments described herein.

[0049] Regarding the effect of elevation gap size on the beam pattern, FIG. 12 is a plot showing the effect of different gap sizes in the transducer on the beam pattern. This example is provided for illustrative purposes only and includes only the specific configuration, as additional configurations can be constructed utilizing the methods disclosed herein. FIG. 12 shows that the wider the gap, the wider the elevation beam width in the "transition region" (e.g., the transition from near field to far field, which is approximately 10-15 mm in this example). Also, the wider the gap, the narrower the far field beam. Specifically, FIG. 12 contrasts the resulting -3 dB elevation beam profile of a 3-row 1.25D array for various gap size values ​​between the center row and the outer rows of a transducer including embodiments described herein. These non-limiting examples also utilize fixed focus lenses. In FIG. 12, the solid line is the resulting elevation beam profile, where only the center row is turned on for depths up to 15 mm, and all three rows are turned on for depths beyond 10-15 mm. The different lines represent different kerf widths between the center and outer rows (e.g., 0 mil, 5 mil, 10 mil, 20 mil). In this example, the items raised second, i.e., all rows with no electronic control and a 0 mil gap, and the items raised third, i.e., all rows with a 0 mil gap and electronic control, overlap in the far field. Far field represents greater depth.

[0050] FIG. 13 shows the resulting −3 dB elevation beam profile of a 3-row 1.25D array with a 10 mil gap for various outer row element width values, contrasting adjustments of both row and elevation gap widths. FIG. 13 shows that the elevation beam width in the transition region (e.g., about 10-15 mm) can be significantly reduced by adjusting the outer row width. Thus, depending on the desired clinical application, the row gap width and row element width values ​​can be adjusted to fit different needs. This feature can significantly reduce the manufacturing challenges in maintaining very small gap sizes. FIG. 13 shows simulated elevation beam profile results for a 10 mil gap, where the different lines represent various outer row widths (0.6 mm, 0.8 mm, 1.0 mm). The multi-frequency feature disclosed herein can benefit imaging penetration. Additionally, the multi-frequency feature shown in FIGS. 7-9 and the aforementioned multi-ROC focus options of the lens can also be utilized to further modify and adjust the elevation beam profile (e.g., width) from the near field through the transition region to the far field. In this example, the second listed item, i.e., all rows with no electronic control and a 0 mil gap, and the third listed item, i.e., all rows with a 0 mil gap and electronic control, overlap in the far field. Far field represents greater depth.

[0051] FIG. 14 illustrates the previously discussed advantage of the present invention in that multiple clinical needs can be met by a single transducer (utilizing arrays disclosed herein) since embodiments herein significantly expand the frequency range of the transducer compared to conventional transducers (see, for example, transducer 1000 of FIG. 10 and transducer 1100 of FIG. 11). Accordingly, FIG. 14 illustrates a sample frequency spectrum of a multi-frequency and multi-row transducer fabricated according to aspects of the methodology disclosed herein. This example features a comparison between two different transducers 1410, 1420 to illustrate the wide frequency range of a transducer incorporating aspects of the present invention.

[0052] Figures 15-18 provide additional examples of process steps that include various aspects of the methods for fabricating multi-frequency and multi-row transducers described herein. These process steps include different variations on some of the aspects previously described. These method aspects can be utilized to fabricate some of the transducers shown in Figures 2-4 and 7-11. These process steps 1500, 1600, 1700, 1800 are provided as additional non-limiting examples.

[0053] 15-17 show steps 1500, 1600, and 1700 illustrating a method for fabricating multi-frequency and multi-row transducers as described herein, including the transducers of FIGS. 7-9. Steps 1500, 1600, and 1700 of FIGS. 15, 16, and 17 are particularly relevant to FIGS. 7-9 because the thicknesses of the piezoelectric (acoustic) layers 741, 742, 841, 842, 941, 942 shown in FIGS. 7-9 are different. In each illustrated example of transducer 700, 800, 900, the thicknesses of the various piezoelectric layers in the example are not the same across the examples. Steps 1500, 1600, and 1700 can be utilized to fabricate transducers having piezoelectric layers of various thicknesses as well as to fabricate transducers having piezoelectric layers of the same thickness. However, the opposite is not true, as the steps discussed above cannot be utilized to fabricate transducers with inconsistent thicknesses of the piezoelectric layers. Thus, operations 1500, 1600, and 1700 are particularly relevant to the manufacture of the transducer of FIGS.

[0054] To perform the process 1500 of FIG. 15, (for example, an individual and / or machine) casts and machines (1510) a backing block with embedded ground and signal into a U-shaped backing block (in elevation). In some examples, when casting and machining, the individual and / or machine orients the ground on the top of the backing block and the signal on the bottom of the backing block. As shown herein, certain transducers manufactured according to the methods described herein include stacks of different heights. To accommodate these differences, in some embodiments of the invention, an individual and / or machine can machine the bottom of the U-shaped block with cracks of different heights. An individual and / or machine bonds (1520) a piezoelectric layer to the backing block inside the U-shape. As previously mentioned, these may be of different thicknesses (as this particular process 1500 can be used to manufacture transducers including piezoelectric layers of consistent thickness as well as piezoelectric layers of different thicknesses). If a wider gap is desired for the transducer, the individual and / or machine dices (1530) the piezoelectric layer into multiple rows along the azimuth direction (e.g., perpendicular to the elevation direction as shown in FIG. 1). In some examples, this dicing can be skipped if the existing gap is sufficient for the intended purpose. In previous examples, this dicing separated the piezoelectric layer into separate pieces, sometimes called strippers, but in this operation 1500, the piezoelectric layer is already separated before being bonded to the backing block (to accommodate piezoelectric layers of different thicknesses as well as piezoelectric layers of consistent thickness). The individual and / or machine bonds (1540) each piece of the piezoelectric layer to one or more matching layers. In this example, the first matching layer has a conductive surface that can be bonded to the piezoelectric layer. In some examples, the conductive elements of the conductive surface are embedded electrodes.

[0055] Without cutting the conductive surface (which may include the electrodes), an individual and / or machine dices the matching layer (e.g., in elevation) along multiple rows (1550). An individual and / or machine dices the piezoelectric transducer along the elevation (e.g., in azimuth) into multiple columns, separating the piezoelectric layers into separate pieces or strippers by cutting through all the matching layers, each piezoelectric layer, and the backing material (1560). An individual and / or machine fills in the pieces between the rows and columns created by the elevation and azimuth dicing (1570).

[0056] FIG. 16 is an operation 1600 illustrating a method for manufacturing a multi-frequency and multi-row transducer as described herein. As described above, like operation 1500 of FIG. 15, operation 1600 can be utilized to manufacture transducers with piezoelectric layers of various thicknesses. In operation 1600, an individual and / or machine casts and machines a backing block with embedded ground and signal into a backing block with multiple U-shaped slots in elevation, with the ground at the top of the backing block and the signal at the bottom of the backing block (1610). An individual and / or machine dices the piezoelectric layer into multiple rows in elevation to form separate strippers (1620). As described above, the piezoelectric layers can have different thicknesses. Dicing the piezoelectric layer in this manner separates the piezoelectric layer into separate pieces or strippers. An individual and / or machine places the strippers (formed by dicing) into the machined slots in the backing block (1630). An individual and / or machine bonds one or more matching layers to the stripper (1640). In this example, the first matching layer bonded to the stripper has conductive electrodes, which creates an initial bond for bonding the first matching layer to the conductive element. An individual and / or machine dices the matching layer along multiple rows (e.g., in elevation) to completely cut through the conductive electrodes on the first matching layer surface (1650). An individual and / or machine further dices the piezoelectric transducer along the elevation (e.g., in azimuth) to form multiple columns (1660). This type of dicing can be characterized as deep dicing because it separates the piezoelectric material to the stripper by cutting through all of the matching layers. Gaps and kerfs created by the dicing are filled (1670).

[0057] FIG. 17 illustrates an operation 1700 illustrating various aspects of the method of manufacturing some embodiments of the present invention, specifically the multi-frequency and multi-row transducers described herein. As shown in FIG. 17, to perform this operation 1700, an individual and / or machine embeds the signal flex and ground return flex inside a backing block (1710). An individual and / or machine dices the piezoelectric layer into multiple rows at an elevation angle and forms a stack configuration by aligning the diced portions at a distance from each other (forming gaps) on the backing block (1720). As mentioned above, the thickness of the piezoelectric layer can vary (as this operation 1700 can be utilized in this situation similar to how operations 1500 and 1600 can be utilized). In some examples, operation 1700 includes machining multiple U-shaped slots in the backing block with different heights in the center row and the outer rows to ultimately provide a flat surface (e.g., on the outermost matching layer surface) on the front of the transducer after all the stacks are added together. The individual and / or machine then aligns the stacks with different thicknesses inside the slots at a distance from each other on the backing block (forming gaps). The individual and / or machine bonds (1730) one or more matching layers to the diced piezoelectric layer portions mentioned earlier in this paragraph. This bonds a conductive surface of one of the matching layers to a surface of each of the diced piezoelectric layer portions. The individual and / or machine removes (1740) a portion of the one or more matching layers to form a cavity (or gap) in the portion of the one or more layers at the elevation angle to form a structure. In some instances, the cavity separates the entire layer structure into pieces, but in some instances, the matching layer and / or conductive surface remain intact at the elevation angle. The individual and / or machine dices (1750) these structures into multiple rows in azimuth (with kerfs between them) to form the final multidimensional array. Each stack element has a height in elevation and a width perpendicular to the height. Fill the cavities (gaps) and kerfs with material (1760).

[0058] FIG. 18 is a process 1800 illustrating a method for fabricating a multi-frequency and multi-row transducer as described herein. It is most similar to the process 1700 illustrated in FIG. 17. The process 1800 of FIG. 18 includes a more specific (but non-limiting) example than the process 1700 of FIG. 17 and is provided for illustrative purposes only. While FIGS. 15-17 can be utilized for both equivalent and unequal thicknesses of the piezoelectric layers, FIG. 18 serves to illustrate an example where the piezoelectric layers have different thicknesses. To begin the process 1800, an individual and / or machine embeds (1810) a signal flex and a ground return flex inside a backing block. Multiple U-shapes can be machined into the backing block. Returning to operation 1800, the individual and / or machine forms a stack configuration by dicing piezoelectric layers having different thicknesses into multiple rows, and aligns the diced portions on a backing block to form gaps between the stacks, or aligns and bonds stacks having different thicknesses inside slots at a distance from each other on a backing block (1820). The individual and / or machine bonds one or more matching layers to the (here) diced piezoelectric layers (1830). In this example, the first matching layer includes a conductive electrode, so that the first matching layer of the center row and the outer rows (of the formed multiple rows) can be connected to the piezoelectric layers and ground return at the U-shaped shoulder. The machine or user performing operation 1800 removes a portion of one or more matching layers to form a cavity in a portion of the one or more layers at an elevation angle (1840). In some examples, removing these portions includes forming and completely cutting one or more layers at an elevation angle to improve separation between the multiple rows. A person and / or machine further dices the transducers by dicing each row into columns in azimuth to form the final multi-dimensional array (1850). The stack elements each have a height in elevation and a width perpendicular to this height. A user or machine fills the cavities and gaps (from the dicing) with material (1860).

[0059] FIG. 19 is an operation 1900 provided to include some additional details related to a particular example of a transducer manufacturing process described herein. In this operation 1900, a machine and / or individual embeds two grounds and multiple signals into a backing block, with the two grounds positioned near the edge at the elevation (1910). The machine and / or individual machines the block into one or more U-shaped slots and exposes leads at the top and bottom of the U-shaped slots (1920). The machine and / or individual bonds one or more piezoelectric layers to the U-shaped slots of the backing block (1930). The machine and / or individual separates the piezoelectric layers into separate pieces or strippers with gaps defined between the rows by dicing one or more piezoelectric layers at the elevation or by machining gaps between the U-shaped slots (1940). A machine and / or individual bonds the grounds of one or more piezoelectric layers together by bonding one or more matching layers to one or more piezoelectric layers with a conductive electrode surface on the first matching layer proximate the one or more piezoelectric layers (1950). The machine and / or individual dices the matching layer along a multi-row direction to remove a portion without cutting the conductive electrodes on the first matching layer (1960). The machine and / or individual dices (e.g., deep) the multi-row stack into a plurality of columns (e.g., elements) along an elevation direction (1970). The machine and / or individual fills (1980) the portions where the matching layer was removed and the portions where kerfs were formed from the (e.g., deep) dicing.

[0060] FIG. 20 is an operational process 2000 illustrating various aspects of an example of a method disclosed herein. In some examples herein, the method includes a machine and / or individual embedding a signal flex and a ground return flex inside a backing block (2010). The machine and / or individual forms stack configurations, each stack configuration having a height in elevation and a width perpendicular to the height (2020). As shown in FIG. 20, in this example, the machine and / or individual forms the stack configurations by performing different activities. The machine and / or individual dices the piezoelectric layer into multiple rows in elevation of the piezoelectric layer, which dicing separates the piezoelectric layer into piezoelectric layer portions (2021). The machine and / or individual defines a beam pattern for the transducer by aligning the piezoelectric layer portions on the backing block, so that each piezoelectric layer portion is aligned at a distance from another piezoelectric layer portion (2022). Based on the alignment, the machine and / or individual forms a gap between each piezoelectric layer portion and each adjacent aligned piezoelectric layer portion (2023). In this example, after the machine and / or individual forms the stack configuration, the machine and / or individual forms a stack by bonding one or more matching layers to the piezoelectric layer portions by utilizing a conductive surface of a first matching layer of the one or more matching layers (2030). The machine and / or individual forms a cavity in the one or more matching layers (2040). The machine and / or individual dices the stack into a plurality of elements along an elevation direction (2050). The machine and / or individual fills the cavity with material (2060).

[0061] Several array structures and interconnection schemes for fabricating multi-row (e.g., 1.25D, 1.5D, 1.75D, etc.) and multi-frequency transducers are described herein. During the fabrication process, the gap between the rows can be widened to several wavelengths, and both the gap and row width can be adjusted to change the beam pattern. These fabrication methods provide a flexible means of controlling the beam pattern to meet various clinical needs for resolution and penetration by adjusting not only the multi-row width as in conventional multi-row 1.25D, 1.5D, or 1.75D array designs, but also the gap between the rows. Thus, by making these adjustments, various beam pattern requirements for different clinical applications can be met. A slight thickness difference in the piezoelectric material (layer) between the center row and the outer rows can be used to compensate for impedance mismatch. For example, if the gap between the center row and the outer rows is large, the width of the center row can be smaller than the combination of the two outer rows. Reducing the thickness of the piezoelectric layer in the center row can make the electrical impedance of the center row closer to the electrical impedance of the outer rows.

[0062] The utility of the transducer is enhanced by adding multi-frequency features to a conventional multi-row transducer when compared to existing transducers, as the frequency range can be significantly broadened so that the transducer frequency range can be useful for multiple clinical applications. Thus, a single transducer can be utilized for multiple clinical applications due to its frequency range, rather than multiple transducers. A known challenge of transducers is connecting the electrical element to the acoustic element, but this issue is simplified in the processes described herein, as the manufacturing process described herein can include embedding both the signal flex and the ground return flex inside the backing block, as shown in Figures 5-6. These methods herein are compatible with certain known manufacturing processes, and therefore, modifications to advanced, high performance multi-row transducers can be integrated into the process in a cost-effective manner, as only limited modifications are introduced.

[0063] An embodiment of the invention includes transducers and methods of manufacturing these transducers. In some examples of the method, the method includes embedding a signal flex and a ground return flex inside a backing block. The method also includes forming stack configurations, each stack configuration having a height in elevation and a width perpendicular to the height, the forming includes dicing the piezoelectric layer into a plurality of rows in the elevation of the piezoelectric layer, separating the piezoelectric layer into piezoelectric layer portions, dicing, defining a beam pattern for the transducer by aligning the piezoelectric layer portions on the backing block, each piezoelectric layer portion being aligned at a distance from another piezoelectric layer portion, and forming a gap between each piezoelectric layer portion and each adjacent aligned piezoelectric layer portion based on the aligning. The method includes forming a stack by bonding one or more matching layers to the piezoelectric layer portions by utilizing a conductive surface of a first matching layer of the one or more matching layers. The method also includes forming a cavity in the one or more matching layers. The method includes dicing the stack into a plurality of elements along the elevation direction. The method includes filling the cavity with a material.

[0064] In other examples of methods for manufacturing a transducer, the method also includes embedding a signal flex and a ground return flex inside a backing block. These examples include forming stack configurations, each stack configuration having a height in elevation and a width perpendicular to the height, the forming includes dicing a piezoelectric layer with a front electrode in an elevation piezoelectric layer into a plurality of rows, the dicing separating the piezoelectric layer into piezoelectric layer portions, aligning the piezoelectric layer portions on the backing block, each piezoelectric layer portion being aligned at a distance from another piezoelectric layer portion, and forming a gap between each piezoelectric layer portion and each adjacent aligned piezoelectric layer portion based on the aligning. The method also includes forming a plurality of row stacks, the forming includes bonding one or more matching layers to the piezoelectric layer portions by utilizing a conductive surface of a first matching layer of the one or more matching layers, connecting the front electrode to the ground return through the conductive surface, forming a cavity in the one or more matching layers, and dicing the plurality of row stacks into a plurality of elements along the elevation direction. These examples also include filling the cavity with a material.

[0065] In some examples, embedding the signal flex and the ground return flex within the backing block includes machining the signal flex and the ground return flex into one or more slots in the backing block, where the machining creates one or more slots in the backing block, and forming the stack configuration includes aligning the stack configuration within the one or more slots.

[0066] In some examples, aligning the piezoelectric layer portions on the backing block includes positioning each piezoelectric layer portion within one of the one or more slots and filling gaps between each piezoelectric layer portion with additional material.

[0067] In some examples, the method includes selecting the material and the additional material from the group consisting of air, room temperature curing silicone, a backing material, and a material mixed with the microballoons.

[0068] In some examples, forming the cavity includes forming a cavity in a portion of the one or more matching layers that includes a conductive surface at an elevation angle, and the method includes connecting a front electrode of the piezoelectric layer portion with an embedded ground return flex via the conductive surface.

[0069] In some examples, forming the elements includes dicing the stack completely along the elevation direction.

[0070] In some examples, defining a beam pattern for the transducer includes selecting a width of a gap between the rows.

[0071] In some examples, forming the stack configuration further includes bonding a dematching layer to at least one piezoelectric layer portion.

[0072] In some examples, forming the stack configurations further includes positioning the stack configurations in three rows at an elevation angle along the azimuth axis, each row including at least one stack configuration, the three rows including one inner row and two outer rows, the positioning including selecting, for the inner row, at least one stack configuration of a first height, a first width, and a first stack thickness configuration, and selecting, for each outer row of the two outer rows, at least one stack configuration of a second height, a second width, and a second stack thickness configuration.

[0073] In some examples, the first height and the second height may or may not be equal, the first width and the second width may or may not be equal, and the first stack thickness configuration and the second stack thickness configuration may or may not be equal to one another.

[0074] In some examples, the method includes attaching a lens to a portion of the one or more matching layers such that the one or more matching layers are located between a portion of the piezoelectric layer and the lens.

[0075] In some examples, the defining includes defining the beam pattern in an elevation plane.

[0076] In some examples, defining a beam pattern for the transducer by aligning the piezoelectric layer portions on the backing block further includes dicing the stack into a plurality of elements along an elevation direction and aligning the plurality of elements on the backing block in both the elevation and azimuth directions.

[0077] In some examples, the first height and the second height are equal.

[0078] In some instances, the first height and the second height are not equal.

[0079] In some examples, the first stack thickness configuration and the second stack thickness configuration are equivalent.

[0080] In some examples, the first stack thickness configuration and the second stack thickness configuration are not equivalent.

[0081] In some examples, the first width and the second width are equal.

[0082] In some examples, bonding the one or more matching layers to the piezoelectric layer portion further includes coupling a ground of the piezoelectric layer portion to a ground return flex via the conductive surface of the first matching layer.

[0083] In some examples, the conductive surface comprises an electrode.

[0084] In some examples, the method includes selecting a lens from the group consisting of a single radius focus lens and a multiple radius focus lens.

[0085] The transducers described herein include transducers including a lens, a signal flex and a ground return flex inside a backing block, and a stack configuration aligned on the backing block. In some examples, the stack configuration includes piezoelectric layers, where a gap is formed between each piezoelectric layer and each adjacent aligned piezoelectric layer at an elevation angle, each stack configuration has a height at an elevation angle, a width perpendicular to the height, and a stack thickness configuration, where the stack thickness configuration is perpendicular to the height and perpendicular to the width, and one or more matching layers coupled to the lens and bonded to each piezoelectric layer, where a conductive surface of one of the one or more matching layers is bonded to a top surface of each piezoelectric layer, the one or more matching layers include one or more cavities, and the cavities are filled with a material.

[0086] In other examples herein, the transducer includes a lens, a signal flex and a ground return flex inside a backing block, and a stack arrangement aligned on the backing block. In these examples, each stack arrangement of the stack arrangement is aligned on the backing block with at least two outer rows and a center row. The center row generates a first frequency signal and the at least two outer rows generate a second frequency signal, and the frequency of the first frequency signal is not equal to the frequency of the second frequency signal. Each of the stack arrangements includes a piezoelectric layer, where a gap is formed at an elevation angle between each piezoelectric layer and each adjacent aligned piezoelectric layer, and one or more matching layers coupled to the lens and bonded to each piezoelectric layer, where a conductive surface of one of the one or more matching layers is bonded to a top surface of each piezoelectric layer, the one or more matching layers include one or more cavities, and the cavities are filled with a material.

[0087] In some examples of transducers, the heights of the stack configurations may or may not be equal to one another, the widths of the stack configurations may or may not be equal to one another, and the stack thickness configurations may or may not be equal to one another.

[0088] In some examples of the transducer, the at least one stack configuration further comprises a dematching layer coupled to the piezoelectric layer of the at least one stack configuration.

[0089] In some examples of transducers, the backing block includes three or more U-shaped pierce block sections with machined backing shoulder strippers, the ground return flex is embedded in the machined backing shoulder strippers, and the signal flex is at the bottom position of the backing block to define the connection in a stacked configuration.

[0090] In some examples of the transducer, the machined backing shoulder strippers include two outer machined backing shoulder strippers and two or more inner machined backing shoulder strippers.

[0091] In some examples of the transducer, each of the stack arrangements aligned on the backing block is aligned inside one or more of three or more U-shaped through block sections that form at least two outer rows and a central row.

[0092] In some examples of transducers, the center row generates a first frequency signal and at least two outer rows generate a second frequency signal.

[0093] In some examples of the transducer, the frequency of the first frequency signal is not equal to the frequency of the second frequency signal.

[0094] In some examples of transducers, the cavity extends through each of one or more matching layers.

[0095] In some examples of transducers, the cavity does not extend through the conductive surface.

[0096] In some examples of transducers, the material used to fill the cavity is from the group consisting of air, room temperature curing silicone, a backing material, and a material mixed with microballoons.

[0097] In some examples of the transducer, one or more matching layers bonded to each stack configuration have a layer height at an elevation angle, a layer width perpendicular to the layer height, and a stack thickness configuration that is perpendicular to the layer height and perpendicular to the layer width, and the one or more matching layers bonded to each stack configuration do not have equal layer heights.

[0098] In some examples of the transducer, one or more matching layers have a layer height at an elevation angle, a layer width perpendicular to the layer height, and a stack thickness configuration, where the stack thickness configuration is perpendicular to the layer height and perpendicular to the layer width, and the width of each matching layer of the one or more matching layers is equal.

[0099] In some examples of the transducer, one or more matching layers bonded to each stack configuration have a layer height at an elevation angle, a layer width perpendicular to the layer height, and a stack thickness configuration, where the stack thickness configuration is perpendicular to the layer height and perpendicular to the layer width, and the one or more matching layers bonded to each stack configuration do not have equal stack thickness configurations.

[0100] In some examples of the transducer, the conductive surface comprises an electrode.

[0101] In some examples of transducers, the stack configuration is aligned on a backing block in both elevation and azimuth.

[0102] In some examples of transducers, the stacked configurations are of equal height.

[0103] In some examples of transducers, the stack heights are not equal.

[0104] In some examples of transducers, the widths of the stacked configurations are equal.

[0105] In some examples of transducers, the widths of the stacked configurations are not equal.

[0106] In some examples of transducers, the lamination thickness configurations are equivalent.

[0107] In some instances of the transducers, the stack thickness configurations are not equivalent.

[0108] In some examples of the transducer, the lens is selected from the group consisting of a single radius focus lens and a multiple radius focus lens.

[0109] The flowcharts and block diagrams in the figures illustrate the structure, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of instructions that includes one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions described in the blocks may be performed in a different order than the order described in the figures. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flowchart diagrams, as well as combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a dedicated hardware-based system that executes the specified functions or operations, or a combination of dedicated hardware and computer instructions.

[0110] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0111] Corresponding structures, materials, acts, and equivalents of all means-plus-function or step-plus-function elements in the following claims are intended to include any structures, materials, or acts for performing functions in combination with other specifically claimed elements, when present. The description of one or more embodiments has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments have been selected and described to best explain various aspects and practical applications and to enable others skilled in the art to understand various embodiments with various modifications as suitable for the particular use contemplated.

Claims

1. 1. A method of manufacturing a transducer, comprising: The signal flex and ground return flex are embedded inside the backing block. forming stack configurations, each of the stack configurations having a height in elevation and a width perpendicular to the height; The forming comprises: dicing the piezoelectric layer into a plurality of rows at an elevation angle of the piezoelectric layer, the dicing separating the piezoelectric layer into piezoelectric layer portions; defining a beam pattern for the transducer by aligning the piezoelectric layer portions on the backing block; defining the beam pattern includes aligning each piezoelectric layer portion at a distance from other piezoelectric layer portions; forming a gap between each piezoelectric layer portion and each adjacent aligned piezoelectric layer portion based on the aligning; This includes: forming a stack by bonding the one or more matching layers to the piezoelectric layer portion using a conductive surface of a first matching layer of the one or more matching layers; forming a cavity in the one or more matching layers; dicing the stack along an elevation direction into a plurality of elements; filling the cavity with a material; A method comprising:

2. Embedding a signal flex and a ground return flex inside the backing block includes: machining the signal flex and the ground return flex into one or more slots in the backing block; creating the one or more slots in the backing block by said machining; This includes: forming the stack configuration includes aligning the stack configuration within the one or more slots; The method of claim 1.

3. Aligning the piezoelectric layer portion on the backing block includes: positioning each piezoelectric layer portion within one of the one or more slots; filling the gaps between each piezoelectric layer portion with additional material; The method of claim 2 , comprising:

4. selecting said material and said additional material from the group consisting of air, room temperature curing silicone, a backing material, and a substance mixed with microballoons; The method of claim 3 further comprising:

5. forming the cavity includes forming the cavity in a portion of the one or more matching layers that includes the conductive surface; The method comprises: connecting the front electrode of the piezoelectric layer portion to the ground return flex via the conductive surface; The method of claim 1 further comprising:

6. The method of claim 1 , wherein forming the elements comprises dicing the stack completely along the elevation direction.

7. The method of claim 1 , wherein defining a beam pattern for the transducer comprises selecting a width of the gap between the plurality of rows.

8. The method of claim 1 , wherein forming the stack configuration further comprises bonding a dematching layer to at least one piezoelectric layer portion.

9. forming the stack configuration positioning the stack configuration in three rows at the elevation angle along the azimuth axis; It further includes: each of the rows includes at least one of the stack configurations, and the three rows include one inner row and two outer rows; The positioning step includes: selecting at least one stack configuration for the inner row of stacks having a first height, a first width, and a first stack thickness configuration; selecting at least one stack configuration of a second height, a second width, and a second stack thickness configuration for each outer row of the two outer rows; Including, The method of claim 1.

10. the first height and the second height may or may not be equal; the first width and the second width are equal; the first stack thickness configuration and the second stack thickness configuration are equivalent or unequal to each other; 10. The method of claim 9.

11. attaching the lens to a portion of the one or more matching layers such that the one or more matching layers are positioned between the piezoelectric layer portion and the lens; The method of claim 1 further comprising:

12. The method of claim 1 , wherein the defining comprises defining the beam pattern in an elevation plane.

13. The defining step comprises: dicing the stack into a plurality of elements along the elevation direction; aligning the plurality of elements on the backing block in both the elevation and azimuth directions; The method of claim 1 , comprising:

14. Lenses and Signal flex and ground return flex inside the backing block, a plurality of stack configurations aligned on the backing block; A transducer comprising: Each of the stack configurations comprises: a piezoelectric layer having an elevation gap between each piezoelectric layer and each adjacently aligned piezoelectric layer, each stack configuration having a height at an elevation angle, a width perpendicular to the height, and a stack thickness configuration perpendicular to the height and perpendicular to the width; one or more matching layers coupled to the lens and bonded to each piezoelectric layer, a conductive surface of one of the one or more matching layers being bonded to a top surface of each of the piezoelectric layers, the one or more matching layers comprising one or more cavities, the cavities being filled with a material; Equipped with Transducer.

15. the heights of the stacked configurations may be equal to one another or may be unequal to one another; The widths of the stacked configurations are equal to each other; The stack thickness configurations may be equivalent to one another or may not be equivalent to one another; 15. The transducer of claim 14.

16. 15. The transducer of claim 14, wherein at least one of the stack configurations further comprises a dematching layer coupled to the piezoelectric layer of the at least one of the stack configurations.

17. the backing block comprises three or more U-shaped pierce block sections with machined backing shoulder strippers; the ground return flex is embedded in the machined backing shoulder stripper; the signal flex resides at the bottom of the backing block to define a connection for the stack configuration; 15. The transducer of claim 14.

18. 20. The transducer of claim 17, wherein the machined backing shoulder strippers comprise two outer machined backing shoulder strippers and two or more inner machined backing shoulder strippers.

19. 20. The transducer of claim 17, wherein each of the stack arrangements aligned on the backing block is aligned inside one or more of the three or more U-shaped through block portions forming at least two outer rows and a center row.

20. the center row generates a first frequency signal and the at least two outer rows generate a second frequency signal; the frequency of the first frequency signal is not equal to the frequency of the second frequency signal; 20. The transducer of claim 19.

21. 15. The transducer of claim 14, wherein the cavity extends through each layer of the one or more matching layers.

22. The transducer of claim 14 , wherein the cavity does not extend through the conductive surface.

23. 15. The transducer of claim 14, wherein the material used to fill the cavity is from the group including air, room temperature curing silicone, a backing material, and a material mixed with microballoons.

24. the one or more matching layers bonded to each stack configuration have a layer height at the elevation angle, a layer width perpendicular to the layer height, and a stack thickness configuration; the stack thickness configuration is perpendicular to the height of the layer and perpendicular to the width of the layer; the one or more matching layers bonded to each stack configuration do not have equal layer heights; 15. The transducer of claim 14.

25. the one or more matching layers have a layer height at the elevation angle, a layer width perpendicular to the layer height, and a stack thickness configuration; the stack thickness configuration is perpendicular to the height of the layer and perpendicular to the width of the layer; the layer width of each matching layer of the one or more matching layers is equal; 15. The transducer of claim 14.

26. the one or more matching layers bonded to each stack configuration have a layer height at the elevation angle, a layer width perpendicular to the layer height, and a stack thickness configuration; the stack thickness configuration is perpendicular to the height of the layer and perpendicular to the width of the layer; the one or more matching layers bonded to each of the stack configurations do not have the same stack thickness configuration; 15. The transducer of claim 14.

27. The transducer of claim 14 , wherein the conductive surface comprises an electrode.

28. 15. The transducer of claim 14, wherein the stack configuration is aligned on the backing block in both elevation and azimuth.

29. Lenses and Signal flex and ground return flex inside the backing block, a stack arrangement aligned on the backing block; A transducer comprising: Each stack arrangement of the stack arrangements is aligned on the backing block in at least two outer rows and a central row, the central row generating a first frequency signal and the at least two outer rows generating a second frequency signal, the frequency of the first frequency signal not equal to the frequency of the second frequency signal; Each of the stack configurations comprises: a piezoelectric layer, each of said piezoelectric layers having a gap at an elevation angle formed between it and each adjacently aligned piezoelectric layer; one or more matching layers coupled to the lens and bonded to each of the piezoelectric layers, a conductive surface of one of the one or more matching layers being bonded to a top surface of each of the piezoelectric layers, the one or more matching layers comprising one or more cavities, the cavities being filled with a material; Equipped with Transducer.

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