An ultrasonic transducer

Abstract

An embodiment of this specification provides an ultrasonic transducer comprising a piezoelectric layer and a matching layer. The matching layer is disposed between the piezoelectric layer and an object to be measured, achieving acoustic matching between the piezoelectric layer and the object to be measured through the matching layer, and converting ultrasonic waves into electrical energy. The acoustic velocity of the matching layer is gradient-distributed in at least one direction. This specification utilizes the gradient distribution of the acoustic velocity of the matching layer to ensure that ultrasonic waves of different frequencies have the same wavelength in the matching layer. This allows for acoustic matching between piezoelectric layers of varying structures and human tissue, improves the transmittance of ultrasonic waves in the matching layer, and increases the bandwidth of the ultrasonic transducer.

Description

Technical Field

[0001] This specification relates to the medical field, and in particular to an ultrasonic transducer. Background Art

[0002] Medical ultrasound imaging is a crucial technology in modern medical imaging. Ultrasonic transducers, the core components of medical ultrasound imaging equipment, utilize the piezoelectric effect to convert electrical energy into ultrasonic waves, which are then transmitted into the human body. They also convert the reflected ultrasonic waves into electrical signals. These signals are then processed to form corresponding images, such as B-ultrasound images.

[0003] Bandwidth is one of the most important performance characteristics of ultrasonic transducers. Existing technologies often require high-bandwidth ultrasonic transducers to transmit and receive ultrasound waves of different frequencies to meet the needs of different scenarios, such as harmonic imaging.

[0004] Therefore, it is desirable to provide an ultrasonic transducer with a higher bandwidth. Summary of the Invention

[0005] One of the embodiments of this specification provides an ultrasonic transducer. The ultrasonic transducer includes: a piezoelectric layer and a matching layer, wherein the matching layer is arranged between the piezoelectric layer and the object to be measured, the piezoelectric layer achieves acoustic matching with the object to be measured through the matching layer, and the piezoelectric layer is used to achieve conversion between ultrasonic waves and electrical energy; the sound velocity of the matching layer is gradient distributed in at least one direction. This specification uses the gradient distribution of the sound velocity of the matching layer to ensure that ultrasonic waves of different frequencies have the same wavelength in matching layers of different structures, thereby achieving acoustic matching between piezoelectric layers of different structures and human tissue, improving the transmittance of ultrasonic waves in the matching layer, and increasing the bandwidth of the ultrasonic transducer.

[0006] In some embodiments, the thickness of the piezoelectric layer includes a first thickness and a second thickness; the first thickness is different from the second thickness.

[0007] In some embodiments, the gradient distribution of the acoustic velocity corresponds to the thickness distribution of the piezoelectric layer.

[0008] In some embodiments, the ultrasonic transducer further includes a backing layer, the backing layer including a first impedance layer and a second impedance layer, the first impedance layer and the second impedance layer are connected, the first impedance layer is connected to the surface of the piezoelectric layer away from the matching layer, and the impedance of the first impedance layer is higher than that of the second impedance layer.

[0009] In some embodiments, the thickness of each point of the piezoelectric layer is equal, the thickness of the first impedance layer includes a third thickness and a fourth thickness; the third thickness is different from the fourth thickness.

[0010] In some embodiments, the thickness of each point of the matching layer is equal.

[0011] In some embodiments, the thickness of the matching layer includes a fifth thickness and a sixth thickness; and the fifth thickness is different from the sixth thickness.

[0012] In some embodiments, the piezoelectric layer includes one or more piezoelectric elements, and the at least one direction includes a length direction and / or a thickness direction of the piezoelectric element.

[0013] In some embodiments, the matching layer includes a first filler and a second filler, and the sound velocity corresponding to the first filler is different from the sound velocity corresponding to the second filler, so that the sound velocity of the matching layer is distributed in a gradient.

[0014] In some embodiments, the first filler and the second filler include inorganic fillers and / or organic fillers. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0016] Figure 1 is a schematic structural diagram of an ultrasonic transducer according to some embodiments of this specification;

[0017] Figure 2 is a frequency characteristic curve diagram of an ultrasonic transducer according to some embodiments of this specification;

[0018] Figure 3 is a schematic diagram of the three-dimensional structure of a first ultrasonic transducer according to some embodiments of this specification;

[0019] Figure 4 is a schematic structural diagram of a first ultrasonic transducer according to some embodiments of this specification;

[0020] Figure 5 is a schematic structural diagram of a first piezoelectric layer of an ultrasonic transducer according to some embodiments of this specification;

[0021] Figure 6 is a schematic structural diagram of a second piezoelectric layer of an acoustic transducer according to some embodiments of this specification;

[0022] Figure 7 is a schematic structural diagram of a third piezoelectric layer of an acoustic transducer according to some embodiments of this specification;

[0023] Figure 8is a schematic structural diagram of a fourth piezoelectric layer of an acoustic transducer according to some embodiments of this specification;

[0024] Figure 9 is a schematic structural diagram of a fifth piezoelectric layer of an acoustic transducer according to some embodiments of this specification;

[0025] Figure 10 is a schematic structural diagram of a sixth piezoelectric layer of an acoustic transducer according to some embodiments of this specification;

[0026] Figure 11 is a schematic structural diagram of a second ultrasonic transducer according to some embodiments of this specification;

[0027] Figure 12 is a schematic diagram of the three-dimensional structure of a second ultrasonic transducer according to some embodiments of this specification;

[0028] Figure 13 is a schematic structural diagram of the second ultrasonic transducer after bonding and cutting according to some embodiments of this specification;

[0029] Figure 14 is a schematic diagram of a multi-array structure after bonding and cutting of the second ultrasonic transducer shown in some embodiments of this specification;

[0030] Figure 15 is a schematic structural diagram of the first backing structure of the ultrasonic transducer after bonding according to some embodiments of this specification;

[0031] Figure 16 is a schematic structural diagram of the second backing structure of the ultrasonic transducer after bonding according to some embodiments of this specification;

[0032] Figure 17 is a schematic structural diagram of the third backing structure of the ultrasonic transducer after bonding according to some embodiments of this specification;

[0033] Figure 18 This is a schematic structural diagram of a fourth backing structure after bonding with different matching layer thicknesses of an ultrasonic transducer according to some embodiments of this specification. DETAILED DESCRIPTION

[0034] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0035] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0036] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0037] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0038] In some embodiments, the medical device may include an image processing device and an ultrasonic transducer. The ultrasonic transducer can convert electrical energy into ultrasonic waves, which are then transmitted into the human body, and convert the ultrasonic waves reflected by the human body into electrical signals. The image processing device is connected to the ultrasonic transducer, and the image processing device receives the electrical signals from the ultrasonic transducer. The electrical signals are processed by the image processing device to produce a corresponding image.

[0039] The image processing device may be a device that processes received signals to obtain images. In some embodiments, the image processing device may include multiple processing units that process electrical signals from the ultrasonic transducer to obtain processed images.

[0040] This specification describes an ultrasonic transducer. This transducer utilizes the piezoelectric effect to convert ultrasonic waves into electrical energy, enabling its application in various business scenarios using ultrasonic measurements. For example, the ultrasonic transducer can be used in medical imaging equipment to output medical images based on ultrasonic waves returned from an object under test (e.g., human tissue). Another example is the ultrasonic transducer used in underwater monitoring equipment to generate corresponding underwater images based on ultrasonic waves returned from underwater objects.

[0041] In some embodiments, the ultrasonic transducer includes a piezoelectric layer that converts electrical energy into ultrasonic waves, which are then transmitted to the object being measured (e.g., human tissue). However, there is often a significant difference in acoustic impedance between the piezoelectric layer and the object being measured, causing most of the ultrasonic waves to be reflected. This results in low transmittance of the ultrasonic waves from the ultrasonic transducer to human tissue, affecting the ultrasonic transducer's efficiency in receiving ultrasonic waves of different frequencies and reducing the transducer's bandwidth.

[0042] The ultrasonic transducer provided in this specification includes a matching layer and a piezoelectric layer. The matching layer is arranged on the upper surface of the piezoelectric layer to achieve acoustic matching with the object to be measured (such as human tissue, etc.). Since the transmittance is affected by the thickness of the matching layer and the wavelength of the ultrasonic wave, the gradient distribution of the sound velocity of the matching layer can make ultrasonic waves of different frequencies have the same wavelength in matching layers of different structures, thereby achieving acoustic matching between piezoelectric layers of different structures and human tissue, improving the transmittance of ultrasonic waves in the matching layer, and increasing the bandwidth of the ultrasonic transducer.

[0043] It should be understood that the application scenarios of the ultrasonic transducer in this specification are merely some examples or embodiments of this specification. For ordinary technicians in this field, without paying any creative work, they can also apply this specification to other similar scenarios based on these drawings.

[0044] The following will be combined Figures 1-10 The ultrasonic transducer involved in the embodiments of this specification is described in detail. It should be noted that the following embodiments are only used to explain this specification and do not constitute a limitation of this specification.

[0045] Figure 1 is a schematic diagram of the structure of an ultrasonic transducer according to some embodiments of this specification. In some embodiments, Figure 1 As shown, ultrasonic transducer 100 primarily includes a matching layer 110 and a piezoelectric layer 120. Matching layer 110 is disposed between piezoelectric layer 120 and the object under test. Piezoelectric layer 120 achieves acoustic matching with the object under test through matching layer 110, and is used to convert ultrasonic waves into electrical energy. The sound velocity of the matching layer is gradient distributed in one or more directions.

[0046] The matching layer is a layered structure that couples the acoustic impedances of adjacent media (i.e., acoustically matches them). In some embodiments, the matching layer can have one or more layers. The matching layer can be configured based on actual needs and is not limited in this embodiment. In some embodiments, the matching layer can be attached to the upper surface of the piezoelectric layer by bonding, welding, or nailing. For example, the lower surface of the matching layer is fixed to the upper surface of the piezoelectric layer by bonding.

[0047] In some embodiments, the matching layer may include one or more matching components. Figure 1 As shown, the matching layer 110 may include a first matching component 110-1, a second matching component 110-2, and a third matching component 110-3. In some embodiments, different matching components may have different structures, materials, or functions, such as different matching components may have different sound velocities.

[0048] The speed of sound refers to the speed at which a sound signal propagates in a certain medium. In some embodiments, the speed of sound in the matching layer may be the speed at which ultrasound waves propagate in the matching layer. In the case where the matching layer includes multiple matching components, the speed of sound in the matching layer may be the speed of sound of different matching components in the matching layer. In some embodiments, the speed of sound of different matching components in the matching layer may be the same or different, for example, Figure 1 As shown, the acoustic velocities of the first matching component 110-1 and the third matching component 110-3 of the matching layer may be the same, while the acoustic velocities of the second matching component 110-2 of the matching layer may be different from the acoustic velocities of the first matching component 110-1 and the third matching component 110-3.

[0049] In some embodiments, at least one direction may include the length direction and / or thickness direction of the piezoelectric array element of the piezoelectric layer. The length direction of the piezoelectric array element may refer to the direction parallel to the first side of the horizontal plane projection of the piezoelectric array element, wherein the horizontal plane projection of the piezoelectric array element includes a first side and a second side, and the first side is longer than the second side. The thickness direction of the piezoelectric array element may refer to the direction perpendicular to the horizontal plane where the piezoelectric array element is located. Exemplarily, at least one direction may include the Y-axis direction and / or the Z-axis direction in the three-dimensional coordinate XYZ, wherein the three-dimensional coordinate system takes the intersection of the first side and the second side of the piezoelectric array element as the origin, the width direction of the piezoelectric array element as the X-axis, the length direction of the piezoelectric array element as the Y-axis, and the thickness direction of the piezoelectric array element as the Z-axis. For specific details of at least one direction, please refer to the following Figure 3 or Figure 11 The relevant description of the three-dimensional coordinates XYZ is not repeated here. Regarding the specific implementation of the piezoelectric array element, please refer to the relevant description of the piezoelectric layer below, which is not repeated here.

[0050] A gradient distribution can refer to a step-by-step or gradual distribution of sound velocity in one or more directions, such as a monotonically decreasing or increasing pattern or a normal distribution. For example, in some embodiments, the gradient distribution of the sound velocity of the matching layer can include a monotonically decreasing or increasing pattern from a first side to a second side of the matching layer, or a decreasing or increasing pattern from the center to the periphery of the matching layer. The first and second sides of the matching layer can be different sides of the matching layer. In some embodiments, the gradient distribution of the sound velocity corresponds to the thickness distribution of the piezoelectric layer. For details, please refer to the relevant description of the piezoelectric layer and will not be repeated here.

[0051] It should be noted that since the frequency of the ultrasound wave is inversely proportional to the thickness of the piezoelectric layer, the uneven thickness distribution of the piezoelectric layer will cause different frequencies of ultrasound waves generated in different areas of the piezoelectric layer. Since the sound velocity of the matching layer is related to the wavelength and frequency of the ultrasound wave, the formula is as follows: λ = c / f, where λ represents the wavelength of the ultrasound wave, c represents the sound velocity of the matching layer, and f represents the frequency of the ultrasound wave. If a matching layer with a uniform sound velocity distribution is used, different ultrasound waves of different frequencies will have different corresponding wavelengths when propagating through the matching layer. In addition, the ratio of the thickness of the matching layer to the wavelength of the ultrasound wave can affect the transmittance. For example, when the thickness of the matching layer is an odd multiple of one-quarter of the wavelength of the ultrasound wave in the matching layer, the ideal transmittance can reach 100%. If the wavelength of the ultrasound wave in the matching layer is unequal, the ratio of the thickness of each point in the matching layer to the wavelength of the ultrasound wave will change, resulting in poor acoustic matching and reduced transmittance.

[0052] In some embodiments of this specification, in order to make the wavelength of ultrasound waves the same in the matching layer, the sound velocity of the matching layer can be set to a gradient distribution to achieve acoustic matching between piezoelectric layers of different structures and human tissue, thereby improving the transmittance of ultrasound waves in the matching layer and increasing the bandwidth of the ultrasonic transducer.

[0053] In some embodiments, the matching layer may include a first filler and a second filler, and the sound velocity corresponding to the first filler is different from the sound velocity corresponding to the second filler, so that the sound velocity of the matching layer is distributed in a gradient.

[0054] Fillers are inert substances used to adjust the physical and / or chemical properties of a device, such as changing the sound velocity of the device by adjusting properties such as elastic modulus and density. In some embodiments, the filler may include inorganic fillers and / or organic fillers, etc. Among them, inorganic fillers and organic fillers have different effects on the sound velocity, and the sound velocity of the matching layer can be adjusted by changing the ratio of the two. For example, organic fillers may include organic substances such as metals (such as tungsten, iron, etc.) and / or metal oxides (such as tungsten trioxide, aluminum oxide, iron oxide, etc.), and inorganic fillers may include inorganic substances such as glass, graphite, and epoxy resin. This specification does not limit the specific implementation of the filler.

[0055] In some embodiments, the first filler and the second filler may include inorganic fillers, non-inorganic fillers, and the like.

[0056] In some embodiments, multiple fillers (such as a first filler and a second filler) can be distributed in a gradient in the matching layer so that the sound velocity of the matching layer can be distributed in a gradient. For example, the first filler can be filled in the first side of the matching layer, and the second filler can be filled in the second side of the matching layer, so that the sound velocity corresponding to the first side of the matching layer is different from the sound velocity corresponding to the second side of the matching layer, thereby achieving a monotonically increasing or decreasing gradient distribution. For example, Figure 1As shown, the first filler can adjust the first matching component 110-1 and the third matching component 110-3 of the matching layer, and the second filler can adjust the second matching component 110-2 of the matching layer. The sound velocity of the first matching component 110-1 of the matching layer is sound velocity c1, and the sound velocity of the third matching component 110-3 of the matching layer is sound velocity c3, and the sound velocity c1 is the same as the sound velocity c3; the sound velocity of the second matching component 110-2 of the matching layer is sound velocity c2, and the sound velocity c1 is different from the sound velocity c2.

[0057] In some embodiments, fillers can be placed in the matching layer through processes such as injection molding or injection molding. In some embodiments, the matching layer can select different fillers based on the different structures of the piezoelectric layer (e.g., thickness gradient distribution, etc.) to achieve acoustic matching between piezoelectric layers of different structures and the object under test.

[0058] In some optional embodiments, the thickness of each point of the matching layer can be equal. Figure 1 As shown, the distance (ie, thickness) between two points of the matching layer 110 in the Z-axis direction is equal.

[0059] In some embodiments of the present specification, by setting the thickness of each point of the matching layer to be equal, there is no need to perform special processing on the thickness of the matching layer according to the structure of the piezoelectric layer, thereby reducing the difficulty of the processing technology of the ultrasonic transducer.

[0060] In some optional embodiments, the thickness of the matching layer may be unequal. The unequal thickness of the matching layer may refer to the thickness of the matching layer including 2 or more thicknesses. In some embodiments, the thickness of the matching layer may include a fifth thickness and a sixth thickness, and the fifth thickness is unequal to the sixth thickness. In some embodiments, the unequal thickness of the matching layer may refer to the thickness of each point of the matching layer being unequal, such as the thickness of the matching layer continuously changing. Exemplarily, the thickness of the matching layer may be at least one of 100um, 150um, 200um, etc. This specification does not limit the specific implementation of the thickness of the matching layer. For specific details of the thickness of the matching layer, please refer to the following Figure 3-Figure 18 The relevant description in will not be repeated here.

[0061] It should be noted that the fifth and sixth thicknesses do not limit the magnitude of the matching layer thickness, but only indicate that the matching layer has different thicknesses. The matching layer thickness also includes other thicknesses, such as the seventh thickness and the eighth thickness, which are not specifically limited in this embodiment.

[0062] In some embodiments of this specification, by providing matching layers of different thicknesses, the thickness of the matching layers can be matched with their sound velocity, so that the wavelength of the ultrasound in the matching layers is consistent, thereby improving the transmittance of the ultrasound and realizing different structural designs of the ultrasonic transducer.

[0063] The piezoelectric layer is a layered structure made using devices that exhibit the piezoelectric effect. In some implementations, the piezoelectric wafer can be made of one or more materials selected from piezoelectric crystals (such as quartz crystals, lithium iodate, etc.), piezoelectric semiconductors (such as cadmium sulfide, zinc oxide, etc.), piezoelectric ceramics, piezoelectric composite materials, or piezoelectric polymers, although this specification is not intended to limit this. In some embodiments, the piezoelectric layer can include piezoelectric devices in the form of discs, strips, rods, cylinders, and the like.

[0064] In some embodiments, the piezoelectric layer may include one or more piezoelectric wafers, wherein the piezoelectric wafers may be devices having a piezoelectric effect. Figure 1 As shown, a piezoelectric chip can be used as the piezoelectric layer 120. In some embodiments, when there are multiple piezoelectric chips, the multiple piezoelectric chips can be stacked to form a piezoelectric layer, such as vertical stacking, horizontal arrangement, and multiple arrays side by side. The specific implementation of multiple piezoelectric chips can refer to the following Figure 4 The relevant description in will not be repeated here.

[0065] In some embodiments, the piezoelectric layer may include one or more piezoelectric elements.

[0066] The piezoelectric array element may be an element in the array structure of the piezoelectric layer, which may be divided according to the minimum working unit of the piezoelectric layer. In some embodiments, the array structure of the piezoelectric layer may include a single array, a double array, a triple array, a quad array, a quintuple array or other multi-array side-by-side structures, and this specification does not specifically limit the number of arrays. Among them, the array may be a collection of piezoelectric array elements in the same column stacked along the width direction of the piezoelectric array element. In some embodiments, the width direction of the piezoelectric array element may refer to the direction of the second side parallel to the horizontal plane projection of the piezoelectric array element, wherein the first side of the horizontal plane projection of the piezoelectric array element is longer than the second side. Exemplarily, the width direction of the piezoelectric array element may be the X-axis direction of the three-dimensional coordinate XYZ. For the specific implementation of the width direction, please refer to the following Figure 3 The relevant content in will not be repeated here.

[0067] In some embodiments, a piezoelectric array element may include one or more piezoelectric wafers. Figure 1 As shown, a piezoelectric array element in the piezoelectric layer 120 may include a piezoelectric chip. Other specific implementations of the piezoelectric array element can refer to the following Figure 1-10 The relevant content in will not be repeated here.

[0068] In some embodiments, the thickness of the piezoelectric layer may be related to the thickness of the piezoelectric wafer. In some embodiments, when the piezoelectric wafers are stacked in a horizontal arrangement or in a multi-array arrangement, the thickness of the piezoelectric layer may be equal to the thickness of the piezoelectric wafer. Figure 1As shown, the piezoelectric layer 120 includes a piezoelectric wafer, and the thickness of the piezoelectric layer may be equal to the thickness of the piezoelectric wafer.

[0069] In some embodiments, the thickness of the piezoelectric layer may be different. The different thickness of the piezoelectric layer may refer to the thickness of the piezoelectric layer including two or more thicknesses. In some embodiments, the thickness of the piezoelectric layer may include a first thickness and a second thickness, and the first thickness and the second thickness are different. For example, Figure 1 As shown, the thickness of the middle portion of the piezoelectric layer 120 (i.e., the first thickness) can be smaller than the thickness of the two ends of the piezoelectric layer (i.e., the second thickness). It should be noted that the first thickness and the second thickness do not limit the number of thicknesses of the piezoelectric layer, but only indicate that the piezoelectric layer has different thicknesses. The thickness of the piezoelectric layer also includes other thicknesses, such as the seventh thickness, the eighth thickness, etc., which are not specifically limited in this embodiment.

[0070] In some embodiments, the thickness distribution of the piezoelectric layer may be a thickness gradient distribution. In some embodiments, the thickness distribution of the piezoelectric layer may include a thickness monotonically increasing or monotonically decreasing from the first side to the second side of the piezoelectric layer, increasing or decreasing from the center to the circumference of the piezoelectric layer, etc. In some embodiments, the monotonically increasing or monotonically decreasing from the first side to the second side of the piezoelectric layer may include a monotonically increasing or monotonically decreasing in a step-like, linear, or other manner. In some embodiments, the increasing or decreasing from the center to the circumference of the piezoelectric layer may include a step-like, linear, curved, parabolic, or other manner. In some embodiments, the thickness distribution of the above-mentioned piezoelectric layer can be set according to actual needs, and this embodiment is not limited here. The specific implementation method of the thickness distribution of the piezoelectric layer can refer to the following Figure 3-10 The relevant content shown will not be repeated here.

[0071] In some embodiments, the thickness of the piezoelectric layer can also be equal. The specific implementation of the equal thickness of the piezoelectric layer can refer to the following Figures 11-18 The relevant content shown will not be repeated here.

[0072] In some embodiments, the gradient distribution of the sound velocity of the matching layer can correspond to the thickness distribution of the piezoelectric layer. In some embodiments, the gradient distribution of the sound velocity of the matching layer can be set based on the thickness distribution of the piezoelectric layer so that the wavelength of the ultrasonic wave is the same in the matching layer. In some embodiments, the sound velocity of the matching layer can include a first sound velocity and a second sound velocity. When the first sound velocity is greater than the second sound velocity and the first thickness of the piezoelectric layer is less than the second thickness, the first sound velocity of the matching layer can correspond to the first thickness of the piezoelectric layer, and the second sound velocity of the matching layer can correspond to the second thickness of the piezoelectric layer. In other words, the sound velocity of the matching layer can be inversely proportional to the thickness of the piezoelectric layer.

[0073] For example, Figure 1As shown, in the Y-axis direction, the middle portion of the piezoelectric layer 120 corresponds to the second matching component 110-2 of the matching layer, the left portion of the piezoelectric layer corresponds to the first matching component 110-1 of the matching layer, and the right portion of the piezoelectric layer corresponds to the third matching component 110-3 of the matching layer. Figure 1 As shown, the thickness of each point of the matching layer 110 is equal. In order to make the wavelength of the ultrasonic wave the same in the matching layer, the sound velocity of the matching layer 110 is inversely proportional to the thickness of the piezoelectric layer. The sound velocity of the second matching component 110-2 of the matching layer is higher than the sound velocity of the first matching component 110-1 and the third matching component 110-3 of the matching layer. The sound velocity c2 of the second matching component 110-2 of the matching layer corresponds to the first thickness of the piezoelectric layer. The sound velocity c1 of the first matching component 110-1 and the sound velocity c3 of the third matching component 110-3 of the matching layer correspond to the second thickness of the piezoelectric layer. The gradient distribution of the sound velocity decreases from the center to the periphery, which corresponds to the thickness distribution of the piezoelectric layer increasing from the center to the periphery. The specific implementation of the correspondence between the sound velocity distribution and the thickness of the piezoelectric layer can be referred to the following Figures 3 to 10 The relevant content shown will not be repeated here.

[0074] In some embodiments of this specification, the gradient distribution of the sound velocity of the matching layer can be set according to the thickness distribution of the piezoelectric layer, so that the wavelength of the ultrasound wave is the same in the matching layer, thereby improving the transmittance of the object to be measured to the ultrasound wave and achieving acoustic matching between the piezoelectric layer and the object to be measured.

[0075] Figure 2 is a frequency characteristic curve diagram of an ultrasonic transducer according to some embodiments of this specification.

[0076] In some embodiments, as Figure 2 As shown, the L2 curve is Figure 1 The frequency curve of the ultrasonic wave corresponding to the middle part of the piezoelectric layer 120 is shown as follows: Figure 1 The left and right parts of the piezoelectric layer 120 shown correspond to the frequency curve of the ultrasonic wave. Figure 1The frequency curve of the ultrasonic wave of the ultrasonic transducer 100 shown in FIG. The frequency curve can represent the corresponding relationship between the frequency of the ultrasonic wave and the sensitivity. The sensitivity can represent the degree of response of the object to be measured to the ultrasonic wave. For example, the sensitivity can represent the ratio of the amplitude value of the ultrasonic wave reflected by the object to be measured to the amplitude value of the ultrasonic wave emitted by the ultrasonic transducer. In some embodiments, the higher the sensitivity of the frequency curve, the greater the response of the object to be measured to the ultrasonic wave. In some embodiments, the resonant frequency of the L2 curve is higher than the resonant frequency of the L1 curve, wherein the resonant frequency is the frequency corresponding to the highest sensitivity of the frequency curve. That is, the frequency of the ultrasonic wave is related to the thickness of the piezoelectric layer. In some embodiments, the bandwidth of the L3 curve is greater than the bandwidth of the L1 curve and the L2 curve. That is, compared with the existing ultrasonic transducer with a single resonant frequency, the ultrasonic transducer provided in the embodiments of this specification can have a larger bandwidth.

[0077] It should be noted that, based on acoustic impedance matching, the acoustic impedances of the first matching component 110-1, the second matching component 110-2, and the third matching component 110-3 of the matching layer can be designed to be the same. As mentioned above, when the thickness of the matching layer is an odd multiple of a quarter wavelength of the ultrasonic wave in the matching layer, the transmittance is high, and the sound velocity of the second matching component 110-2 of the matching layer is higher than the sound velocity of the first matching component 110-1 and the third matching component 110-3 of the matching layer, the following can be obtained. Figure 1 The ultrasonic transducer structure shown in FIG. 1 has matching layers of the same thickness, so that the frequency curve of the ultrasonic wave is as follows: Figure 2 As shown in the L3 curve, a certain ultrasonic transmittance is guaranteed.

[0078] In some embodiments of this specification, the gradient distribution of the sound velocity of the matching layer can achieve acoustic matching between piezoelectric layers of different structures and human tissue, improve the transmittance of ultrasound in the matching layer, and increase the bandwidth of the ultrasonic transducer.

[0079] In some embodiments, the piezoelectric layer may have different structures or compositions. For example, the shape of the piezoelectric layer may include various shapes. The piezoelectric layer may be configured according to actual needs and is not limited in this embodiment.

[0080] In some embodiments, as Figure 1 As shown, the ultrasonic transducer 100 further includes a backing layer 130 , which is disposed on a side of the piezoelectric layer 120 away from the matching layer 110 .

[0081] The backing layer is a layered structure that absorbs ultrasonic waves generated by the piezoelectric layer in a direction opposite to the object to be measured. In some embodiments, the backing layer can include multiple materials, such as a combination of one or more materials such as metals, metal oxides, and organic materials.

[0082] In some embodiments, when the piezoelectric chip of the piezoelectric layer is stimulated to emit ultrasonic waves, the ultrasonic waves propagating in some directions enter the backing layer, where they are strongly reflected. The strongly reflected ultrasonic waves pass through the piezoelectric layer and propagate forward. The specific implementation of the backing layer can be referred to as follows Figure 11 The relevant content shown will not be repeated here.

[0083] Below is Figures 3 to 10 As an example, the specific corresponding relationship between the gradient distribution of the sound velocity of the matching layer and the thickness distribution of the piezoelectric layer when the matching layer has a constant thickness is described in detail.

[0084] Figure 3 It is a schematic diagram of the three-dimensional structure of the first ultrasonic transducer shown in some embodiments of this specification.

[0085] In some embodiments, as Figure 3 As shown, the ultrasonic transducer 300 includes a matching layer 310, a piezoelectric layer 320, a backing layer 330, and an acoustic lens 340. In the Z-axis direction, the acoustic lens 340, the matching layer 310, the piezoelectric layer 320, and the backing layer 330 may be stacked from top to bottom.

[0086] In some embodiments, the ultrasonic transducer further includes an acoustic lens, located on the side of the matching layer away from the piezoelectric layer. The acoustic lens is an acoustic element that converges or diverges sound waves. In some embodiments, the acoustic lens can change the direction of ultrasonic wave transmission, i.e., refract, causing the sound waves to converge or diverge. In some embodiments, the acoustic lens can converge the ultrasonic waves emitted by the matching layer. This specification does not specifically limit the acoustic lens.

[0087] Figure 4 It is a schematic structural diagram of the first ultrasonic transducer shown in some embodiments of this specification. Figure 4 The matching components in the ultrasonic transducer 400 shown are the same as those in the above Figure 1 The matching components in the ultrasonic transducer 100 are similar, and the specific implementation method can refer to Figure 1 The implementation of the matching component.

[0088] In some embodiments, the thickness of the piezoelectric layer increases or decreases from the center of the piezoelectric layer to the periphery. Figure 4As shown, the central second piezoelectric element 320-2 of the piezoelectric layer has a first thickness, while the peripheral first and third piezoelectric elements 320-1 and 320-3 of the piezoelectric layer have a second thickness, with the first thickness being less than the second thickness. The acoustic velocity of the second matching component 310-2 of the matching layer is the first acoustic velocity, while the acoustic velocity of the first and third matching components 310-1 and 310-3 of the matching layer are the second acoustic velocity, with the first acoustic velocity being greater than the second acoustic velocity. In the Y-axis direction, the first acoustic velocity of the second matching component 310-2 of the matching layer corresponds to the first thickness of the piezoelectric layer 320-2. The second acoustic velocity of the first and third matching components 310-1 and 310-3 of the matching layer corresponds to the second thickness of the first and third piezoelectric elements 320-1 and 320-3 of the piezoelectric layer. In other words, the decreasing gradient of the acoustic velocity from the center to the periphery corresponds to the increasing thickness of the piezoelectric layer from the center to the periphery.

[0089] Figure 5 Schematic diagram of the structure of the first piezoelectric layer of the ultrasonic transducer 500 according to some embodiments of this specification.

[0090] In some embodiments, as Figure 5 As shown, the center of the piezoelectric layer (e.g., second piezoelectric element 520-2) has a first thickness, while the periphery of the piezoelectric layer (e.g., first piezoelectric element 520-1 and third piezoelectric element 520-3) has a second thickness. The second thickness increases from the edge of the second piezoelectric element 520-2 toward the periphery, and the first thickness is less than the minimum value of the second thickness. The acoustic velocity of the second matching component 510-2 of the matching layer is the first acoustic velocity, while the acoustic velocity of the first matching component 510-1 and third matching components 510-3 of the matching layer is the second acoustic velocity. The second acoustic velocity decreases from the edge of the second matching component 510-2 toward the periphery, and the first acoustic velocity is greater than the maximum value of the second acoustic velocity. In the Y-axis direction, the first acoustic velocity of the second matching component 510-2 of the matching layer corresponds to the first thickness of the piezoelectric layer 520-2. The second acoustic velocity of the first matching component 510-1 and third matching components 510-3 of the matching layer corresponds to the second thickness of the first piezoelectric element 520-1 and third piezoelectric element 520-3 of the piezoelectric layer. That is, the gradient distribution of the sound velocity decreases from the center to the periphery, which corresponds to the thickness distribution of the piezoelectric layer increasing from the center to the periphery.

[0091] Figure 6 Schematic diagram of the structure of the second piezoelectric layer of the ultrasonic transducer 600 according to some embodiments of this specification. Figure 7 Schematic diagram of the structure of the third piezoelectric layer of the ultrasonic transducer 700 according to some embodiments of this specification.

[0092] In some embodiments, as Figure 6 or Figure 7As shown, the first thickness of the piezoelectric layer is the minimum thickness of the piezoelectric layer, and the second thickness of the piezoelectric layer is the maximum thickness of the piezoelectric layer. The thickness distribution of the piezoelectric layer is a curve from the center point of the piezoelectric layer to the peripheral side (as shown in FIG. Figure 6 ) or a straight line (such as Figure 7 ) increases. In some embodiments, the thickness distribution of the piezoelectric layer can be set according to actual needs, and this embodiment does not limit this. In some embodiments, the sound velocity of the matching layer decreases from the center to the periphery, corresponding to the thickness of the piezoelectric layer increasing from the center to the periphery. Figure 6 As shown, the gradient distribution of the acoustic velocity of the matching layer 610 corresponds to the thickness distribution of the piezoelectric layer 620. That is, the acoustic velocity of the matching layer 610 decreases from the center to the periphery (e.g., a decreasing curve) and the thickness of the piezoelectric layer 620 increases from the center to the periphery (e.g., a decreasing curve).

[0093] In some embodiments, as Figure 7 As shown, the gradient distribution of the acoustic velocity of the matching layer 710 corresponds to the thickness distribution of the piezoelectric layer 720. That is, the acoustic velocity of the matching layer 710 decreases from the center to the periphery (e.g., linearly decreases) and the thickness of the piezoelectric layer 720 increases from the center to the periphery (e.g., linearly increases).

[0094] Figure 8 Schematic diagram of the structure of the fourth piezoelectric layer of the ultrasonic transducer 800 according to some embodiments of this specification.

[0095] In some embodiments, as Figure 8 As shown, the thickness of the central piezoelectric element of piezoelectric layer 820 is a first thickness, while the thickness of the piezoelectric elements on the periphery of the piezoelectric layer changes from the first thickness to a second thickness from the inside out, with the second thickness being greater than the first thickness. In other words, the decreasing acoustic velocity of matching layer 810 from the center to the periphery corresponds to the increasing thickness of the piezoelectric layer from the center to the periphery.

[0096] Figure 9 Schematic diagram of the structure of the fifth piezoelectric layer of the ultrasonic transducer 900 according to some embodiments of this specification.

[0097] In some embodiments, the thickness of the piezoelectric layer decreases monotonically from the first side to the second side of the piezoelectric layer. Figure 9 As shown, the thickness of the piezoelectric layer 920 decreases monotonically from the left side of the piezoelectric layer (i.e., the first side of the piezoelectric layer) to the right side (i.e., the second side of the piezoelectric layer) in a step-like manner. In some embodiments, the acoustic velocity of the matching layer increases monotonically from the first side to the second side, corresponding to the monotonically decreasing thickness of the piezoelectric layer from the first side to the second side. Figure 9As shown, the gradient distribution of the acoustic velocity of the matching layer 910 corresponds to the thickness distribution of the piezoelectric layer 920. In other words, the acoustic velocity of the matching layer 910 increases monotonically in a step-by-step manner from the first side (left side) to the second side (right side), corresponding to the monotonically decreasing thickness of the piezoelectric layer 920 from the first side (left side) to the second side (right side).

[0098] Figure 10 Schematic diagram of the structure of the sixth piezoelectric layer of the ultrasonic transducer 1000 according to some embodiments of this specification.

[0099] In some embodiments, the thickness of the piezoelectric layer increases monotonically from the first side to the second side of the piezoelectric layer. Figure 10 As shown, the thickness of the piezoelectric layer 1020 increases linearly and monotonically from the left side of the piezoelectric layer (i.e., the first side of the piezoelectric layer) to the right side (i.e., the second side of the piezoelectric layer). In some embodiments, the sound velocity of the matching layer decreases monotonically from the first side to the second side, corresponding to the monotonically increasing thickness of the piezoelectric layer from the first side to the second side. Figure 10 As shown, the gradient distribution of the acoustic velocity of the matching layer 1010 corresponds to the thickness distribution of the piezoelectric layer 1020. The acoustic velocity of the matching layer 1010 decreases monotonically from the first side (left side) to the second side (right side), corresponding to the monotonically increasing thickness of the piezoelectric layer 1020 from the first side (left side) to the second side (right side).

[0100] Figure 11 1 is a schematic structural diagram of a second ultrasonic transducer 1100 according to some embodiments of this specification.

[0101] In some embodiments, the backing layer 1130 may include a first impedance layer 1130-1 and a second impedance layer 1130-2, the first impedance layer 1130-1 and the second impedance layer 1130-2 are connected, the first impedance layer 1130-1 is connected to the surface of the piezoelectric layer 1120 away from the matching layer 1110, and the impedance of the first impedance layer is higher than that of the second impedance layer.

[0102] In some embodiments, the lower surface of the matching layer of the ultrasonic transducer is bonded to the upper surface of the piezoelectric layer. The backing layer includes a first impedance layer and a second impedance layer. The upper surface of the first impedance layer can be bonded to the lower surface of the piezoelectric layer, and the lower surface of the first impedance layer is bonded to the upper surface of the second impedance layer. When the piezoelectric chip of the piezoelectric layer is stimulated to emit ultrasonic waves, the ultrasonic waves propagating in a certain direction enter the first impedance layer and are strongly reflected at the interface between the first impedance layer and the second impedance layer. The strongly reflected ultrasonic waves pass through the piezoelectric layer and propagate forward. In some embodiments, the piezoelectric layer and the first impedance layer can be regarded as an equivalent oscillator, and the resonant frequency of the oscillator is inversely proportional to the thickness of the first impedance layer.

[0103] In some embodiments, the backing layer may include multiple materials. For example, the first impedance layer may include a material with high impedance and low acoustic attenuation coefficient, such as a metal, metal oxide, or a mixture thereof. The second impedance layer may include a material with low impedance and high acoustic attenuation coefficient, such as an organic material.

[0104] In some embodiments, the impedance of the first impedance layer is 10 to 40 times the impedance of the second impedance layer. It should be noted that the impedance multiples here are only examples and are not specifically limited in this specification.

[0105] In some embodiments, the thickness of each point of the piezoelectric layer is equal, and the thickness of the first impedance layer may be different. The different thickness of the first impedance layer may refer to the thickness of the first impedance layer being two or more than two thicknesses. In some embodiments, the thickness of the first impedance layer may include a third thickness and a fourth thickness, and the third thickness is different from the fourth thickness. For example, Figure 12 As shown, the thickness of each point of the piezoelectric layer 1120 is equal. The thickness of the first impedance layer 1130-1 includes a third thickness (the middle portion of the first impedance layer 1130-1) and a fourth thickness (the left and right portions of the first impedance layer 1130-1), and the third thickness is less than the fourth thickness. It should be noted that the third thickness and the fourth thickness do not limit the number of thicknesses of the first impedance layer, but only indicate that the first impedance layer has different thicknesses. The thickness of the first impedance layer also includes other thicknesses, such as a ninth thickness and a tenth thickness, which are not specifically limited in this embodiment.

[0106] In some embodiments of the present specification, by cooperating with a low-impedance backing structure and a high-impedance structure, the transmission and reception of ultrasonic waves of different frequencies can be achieved by changing the thickness of the high-impedance backing.

[0107] In some embodiments, the thickness distribution of the first impedance layer may be a thickness gradient distribution. In some embodiments, the thickness distribution of the first impedance layer may include a thickness monotonically increasing or monotonically decreasing from the first side to the second side of the first impedance layer, increasing or decreasing from the center to the circumference of the first impedance layer, etc. In some embodiments, the monotonically increasing or monotonically decreasing from the first side to the second side of the first impedance layer may include a monotonically increasing or monotonically decreasing in a step-like, linear, or other manner. In some embodiments, the increasing or decreasing from the center to the circumference of the first impedance layer may include a step-like, linear, curved, parabolic, or other manner. For specific implementation methods, please refer to the following Figure 15-18 The relevant description shown will not be repeated here.

[0108] In some embodiments, the thickness distribution of the first impedance layer can be set according to actual needs, and this embodiment is not limited here. The specific implementation of the thickness distribution of the first impedance layer can refer to the following Figures 15-18The relevant content shown will not be repeated here.

[0109] Figure 12 It is a schematic diagram of the three-dimensional structure of the second ultrasonic transducer 1200 shown in some embodiments of this specification.

[0110] like Figure 12 As shown, the second ultrasonic transducer is a broadband area array ultrasonic transducer, comprising a matching layer 1110, a piezoelectric layer 1120, a backing layer 1130, and an acoustic lens 1140. The backing layer 1130 includes a first impedance layer 1130-1 and a second impedance layer 1130-2. The piezoelectric layer 1120 may include a first piezoelectric element 1120-1, a second piezoelectric element 1120-2, and a third piezoelectric element 1120-3.

[0111] In some embodiments, the matching layer 1110, the piezoelectric layer 1120, and the backing layer 1130 can be bonded in sequence to produce a second ultrasonic transducer. Exemplarily, the process of obtaining the second ultrasonic transducer is as follows: the piezoelectric layer 1120 and the matching layer 1110 are of equal thickness at each point, and the upper surface of the piezoelectric layer 1120 is bonded to the lower surface of the matching layer 1110. The backing layer 1130 includes a first impedance layer 1130-1 and a second impedance layer 1130-2. The thickness of the first impedance layer 1130-1 increases from the center to the circumference of the first impedance layer, and the upper surface of the first impedance layer 1130-1 is bonded to the lower surface of the piezoelectric layer 1120. The thickness of the second impedance layer 1130-2 decreases from the center to the circumference of the second impedance layer, and the second impedance layer 1130-2 is bonded to the lower surface of the first impedance layer 1130-1, and the lower surface of the second impedance layer 1130-2 is a planar structure. After bonding is completed, the following is obtained. Figure 11 The second ultrasonic transducer 1100 is shown after bonding.

[0112] Figure 13 It is a schematic structural diagram of the second ultrasonic transducer 1300 after bonding and cutting according to some embodiments of this specification.

[0113] In some embodiments, the bonded second ultrasonic transducer may be cut for the first time to obtain a cut second ultrasonic transducer. Figure 13 The cut three-array second ultrasonic transducer 1300 is shown with the cutting direction along the X-axis. The cutting locations can be the left and right edges of the middle portion of the first impedance layer 1130-1. In some embodiments, by cutting the bonded second ultrasonic transducer, four or five arrays of second ultrasonic transducers can be obtained. In some embodiments, the cutting direction and cutting location can be set according to actual needs and are not limited in this embodiment.

[0114] Figure 141 is a schematic diagram of a multi-array structure of the second ultrasonic transducer 1400 after bonding and cutting according to some embodiments of this specification.

[0115] In some embodiments, the second ultrasonic transducer after bonding and cutting is cut a second time to obtain the second ultrasonic transducer after secondary cutting. Figure 14 The second type of ultrasonic transducer 1400 after secondary cutting of the multi-array can be cut in the Y-axis direction, and the cutting positions can be set to be evenly spaced. By bonding the acoustic lens 1140 to the multi-array second type of ultrasonic transducer after bonding and cutting, a second type of ultrasonic transducer with a broadband area array is obtained, such as Figure 12 A second ultrasonic transducer 1200 is shown.

[0116] In some embodiments of the present specification, the third thickness of the first impedance layer 1130-1 (the middle part of the first impedance layer 1130-1) is less than the fourth thickness (the left and right parts of the first impedance layer 1130-1), and the frequency of the ultrasonic wave generated by the second piezoelectric element 1120-2 adhering to the middle part of the first impedance layer 1130-1 is greater than the frequency of the ultrasonic wave generated by the first piezoelectric element 1120-1 and the third piezoelectric element 1120-3 adhering to the left and right parts of the first impedance layer 1130-1, so that the ultrasonic transducer can meet the requirements of transmitting and receiving ultrasonic waves of different frequencies, improve the longitudinal resolution and sensitivity of the image, and increase the bandwidth of the ultrasonic transducer, which is beneficial to harmonic imaging.

[0117] In some embodiments, the piezoelectric layer of the broadband array ultrasonic transducer can be a piezoelectric chip. The piezoelectric array of the piezoelectric layer is obtained by cutting a piezoelectric chip. The thickness of the piezoelectric layer is equal at each point, and it is a multi-array side-by-side structure. This can avoid multiple processing of the piezoelectric chip and reduce the probability of damage to the piezoelectric chip.

[0118] In some embodiments, the gradient distribution of the acoustic velocity of the matching layer corresponds to the thickness distribution of the first impedance layer.

[0119] In some embodiments, the thickness distribution of the first impedance layer may include a monotonically increasing or monotonically decreasing thickness from the first side to the second side of the first impedance layer, or a monotonically increasing or decreasing thickness from the center to the periphery of the first impedance layer. Correspondingly, the gradient distribution of the acoustic velocity of the matching layer may include a monotonically decreasing or monotonically increasing acoustic velocity from the first side to the second side of the matching layer, or a monotonically decreasing or increasing thickness from the center to the periphery of the matching layer, or the like.

[0120] Figure 15 1 is a schematic diagram of the structure of the ultrasonic transducer 1500 after bonding of the first backing structure according to some embodiments of this specification.

[0121] In some embodiments, the acoustic velocity of the matching layer decreases monotonically from the first side to the second side, and the thickness of the first impedance layer increases monotonically from the first side to the second side. Figure 15 As shown, the gradient distribution of the acoustic velocity of matching layer 1510 corresponds to the thickness distribution of first impedance layer 1530-1. The monotonically decreasing acoustic velocity of matching layer 1510 from the first side (left side) to the second side (right side) corresponds to the monotonically increasing thickness of first impedance layer 1530-1 from the first side (left side) to the second side (right side).

[0122] Figure 16 1 is a schematic diagram of the structure of the ultrasonic transducer 1600 after bonding of the second backing structure according to some embodiments of this specification.

[0123] In some embodiments, the acoustic velocity of the matching layer decreases from the center to the periphery, and the thickness of the first impedance layer increases from the center to the periphery. Figure 16 As shown, the gradient distribution of the acoustic velocity of the matching layer 1610 corresponds to the thickness distribution of the first impedance layer 1630-1. The acoustic velocity of the matching layer 1610 decreases from the center to the periphery (e.g., linearly decreases), corresponding to the thickness of the first impedance layer 1630-1 increasing from the center to the periphery (e.g., linearly increases).

[0124] Figure 17 1 is a schematic diagram of the structure of the ultrasonic transducer 1700 after bonding according to the third backing structure shown in some embodiments of this specification.

[0125] like Figure 17 As shown, the gradient distribution of the acoustic velocity of the matching layer 1710 corresponds to the thickness distribution of the first impedance layer 1730-1. The acoustic velocity of the matching layer 1710 decreases from the center to the periphery (e.g., a decreasing curve), which corresponds to the thickness of the first impedance layer 1730-1 increasing from the center to the periphery (e.g., a decreasing curve).

[0126] Figure 18 1 is a schematic structural diagram of a fourth backing structure after bonding with different matching layer thicknesses of the ultrasonic transducer 1800 according to some embodiments of this specification.

[0127] like Figure 18 As shown, the thickness of matching layer 1810 varies at different points. The gradient distribution of the acoustic velocity of matching layer 1810 corresponds to the thickness distribution of first impedance layer 1830-1. The acoustic velocity of matching layer 1810 decreases from the center to the periphery, corresponding to the thickness of first impedance layer 1830-1 increasing from the center to the periphery.

[0128] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: through the gradient distribution of the sound velocity of the matching layer, ultrasonic waves of different frequencies have the same wavelength in matching layers of different structures, thereby achieving acoustic matching between piezoelectric layers of different structures and human tissue, improving the transmittance of ultrasonic waves in the matching layer, and increasing the bandwidth of the ultrasonic transducer.

[0129] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0130] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0131] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0132] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0133] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0134] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0135] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. An ultrasonic transducer, characterized in that: include: Piezoelectric layer and matching layer, wherein, The matching layer is arranged between the piezoelectric layer and the object to be measured, and the piezoelectric layer is acoustically matched with the object to be measured through the matching layer. The piezoelectric layer is used to realize the conversion between ultrasonic waves and electrical energy; the thickness of the piezoelectric layer includes a first thickness and a second thickness; The first thickness and the second thickness are different; the thickness distribution of the piezoelectric layer is a gradient distribution of the thickness; the thickness distribution of the piezoelectric layer includes the thickness monotonically increasing or monotonically decreasing from the first side to the second side of the piezoelectric layer, and increasing or decreasing from the center to the circumference of the piezoelectric layer; The sound velocity of the matching layer is gradiently distributed in at least one direction; the gradient distribution of the sound velocity corresponds to the thickness distribution of the piezoelectric layer; the gradient distribution of the sound velocity of the matching layer includes the sound velocity monotonically decreasing or monotonically increasing from the first side to the second side of the matching layer, and decreasing or increasing from the center to the circumference of the matching layer.

2. The ultrasonic transducer according to claim 1, wherein It also includes a backing layer, which includes a first impedance layer and a second impedance layer. The first impedance layer is connected to the second impedance layer. The first impedance layer is connected to the surface of the piezoelectric layer away from the matching layer. The impedance of the first impedance layer is higher than that of the second impedance layer.

3. The ultrasonic transducer according to claim 2, wherein: The thickness of each point of the piezoelectric layer is equal, and the thickness of the first impedance layer includes a third thickness and a fourth thickness; The third thickness is different from the fourth thickness.

4. The ultrasonic transducer according to claim 1, wherein The thickness of each point of the matching layer is equal.

5. The ultrasonic transducer according to claim 1, wherein The thickness of the matching layer includes a fifth thickness and a sixth thickness; The fifth thickness is different from the sixth thickness.

6. The ultrasonic transducer according to claim 1, wherein The piezoelectric layer includes one or more piezoelectric array elements, and the at least one direction includes a length direction and / or a thickness direction of the piezoelectric array element.

7. The ultrasonic transducer according to claim 1, wherein The matching layer includes a first filler and a second filler. The sound velocity corresponding to the first filler is different from the sound velocity corresponding to the second filler, so that the sound velocity of the matching layer is distributed in a gradient. 8 . The ultrasonic transducer according to claim 7 , wherein the first filler and the second filler comprise inorganic fillers and / or organic fillers.

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