CN115414068A

CN115414068A - Matching layer for ultrasonic transducer and preparation method

Info

Publication number: CN115414068A
Application number: CN202211173845.1A
Authority: CN
Inventors: 刘宇; 司康; 程正
Original assignee: Wuhan United Imaging Healthcare Co Ltd
Current assignee: Wuhan United Imaging Healthcare Co Ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2022-12-02

Abstract

The embodiment of the specification provides a matching layer for an ultrasonic transducer and a preparation method. The matching layer includes at least a first component and a second component. The first component has a first sound velocity, the second component has a second sound velocity, and the first component and the second component are respectively filled at different positions of the same plane of the ultrasonic transducer, so that the sound velocities of the matching layers are in gradient distribution in at least one direction. The components with different sound velocities in the matching layer are filled at different positions, so that the sound velocities of the matching layer are distributed in a gradient manner in at least one direction (such as the elevation angle direction of the matching layer), the transmissivity of the matching layer to sound waves with different frequencies is improved, and the bandwidth of the ultrasonic transducer is increased.

Description

Matching layer for ultrasonic transducer and preparation method

Technical Field

The present disclosure relates to the medical field, and more particularly, to a matching layer for an ultrasound transducer and a method for manufacturing the same.

Background

Medical ultrasound imaging technology is an important technology in modern medical imaging. An ultrasonic transducer is a core component of a medical ultrasonic imaging device, and can transmit and receive ultrasonic signals. The ultrasonic transducer can generate ultrasonic waves by vibration under the excitation of electric signals, can receive echo signals generated after the ultrasonic waves are transmitted to a target organ, and analyzes the echo signals to realize ultrasonic imaging, such as B ultrasonic images.

For an ultrasonic transducer, bandwidth is one of its important properties. In the prior art, the bandwidth is often improved by adding a matching layer or adopting a piezoelectric wafer with different thicknesses, however, the matching layer is usually set to be of the same material and the same thickness, so that the matching layer is difficult to meet the transmission of ultrasonic waves with different frequencies, and the bandwidth of the ultrasonic transducer is limited.

It is therefore desirable to provide a matching layer that is able to satisfy the transmission of ultrasonic waves of different frequencies, so that the ultrasonic transducer has a higher bandwidth.

Disclosure of Invention

One of the embodiments herein provides a matching layer for an ultrasonic transducer comprising at least a first component and a second component. The first component has a first sound velocity, the second component has a second sound velocity, and the first component and the second component are respectively filled at different positions of the same plane of the ultrasonic transducer, so that the sound velocities of the matching layers are in gradient distribution in at least one direction.

In some embodiments, the first component and the second component have the same acoustic impedance and/or the same thickness.

In some embodiments, the first component and the second component have at least one different species of substance; or the first and second components have the same kind of substance, at least one of the same kind of substance having a different proportion, size, and/or structure in the first and second components.

In some embodiments, the material of the first component and/or the second component comprises an epoxy resin; the materials of the first and/or second components further include at least one of a material of a first range of speeds of sound, a material of a second range of speeds of sound, a material of a first range of densities, the first range of speeds of sound being less than the second range of speeds of sound, and a material of a second range of densities, the first range of densities being greater than the second range of densities.

In some embodiments, the first speed of sound ranges from 800m/s to 2000m/s and the second speed of sound ranges from 2800mA first density in the range of 3 g/cm/s to 11000m/s ³ -20g/cm ³ And the second density range is 0.1g/cm ³ -0.8g/cm ³ 。

In some embodiments, the epoxy resin is present in an amount of 100g; the content of material of the first sound velocity range is less than or equal to 60g, or the content of material of the second sound velocity range is less than or equal to 130g, or the content of material of the first density range is less than or equal to 500g, or the content of material of the second density range is less than or equal to 20g.

In some embodiments, the material of the first acoustic velocity range comprises rubber, the material of the second acoustic velocity range may comprise metal oxides and/or inorganic non-metallic compounds of solid structure, the material of the first density range comprises metal, and the material of the second density range comprises inorganic non-metallic compounds of hollow structure and/or plastic expanded microspheres.

In some embodiments, the material of the first component includes epoxy, rubber, and metal, the material of the second component includes epoxy, metal oxide, and an inorganic non-metallic compound of a hollow structure, the first acoustic velocity of the first component is less than the second acoustic velocity of the second component, and the first component and the second component have the same acoustic impedance.

In some embodiments, the epoxy resin comprises at least one of a bisphenol a type epoxy resin, a bisphenol F type epoxy resin; the rubber comprises at least one of thermoplastic SBS elastomer, nitrile rubber, butyl rubber, styrene butadiene rubber, ethylene propylene diene monomer, silicon rubber and fluororubber; the metal comprises at least one of tungsten, copper, iron and lead; the metal oxide comprises at least one of tungsten trioxide, ferric oxide, aluminum oxide, zinc oxide and magnesium oxide; the inorganic non-metallic compound comprises at least one of glass, ceramic and boron carbide.

In some embodiments, the first or second acoustic velocity ranges from 1400m/s to 3500m/s.

One of the embodiments of the present specification also provides an ultrasonic transducer. The ultrasonic transducer comprises a piezoelectric layer and the matching layer, wherein the matching layer is arranged between the piezoelectric layer and an object to be measured, the piezoelectric layer is acoustically matched with the object to be measured through the matching layer, and the piezoelectric layer is used for converting ultrasonic waves and electric energy.

In some embodiments, the thickness of the piezoelectric layer includes at least a first thickness and a second thickness, the first thickness and the second thickness being unequal; the gradient distribution of the acoustic velocity of the matching layer corresponds to the thickness distribution of the piezoelectric layer.

In some embodiments, the gradient profile of the acoustic velocity of the matching layer has an inverse relationship to the thickness profile of the piezoelectric layer.

In some embodiments, the first acoustic velocity of the first component of the matching layer corresponds to a first thickness of the piezoelectric layer, and the second acoustic velocity of the second component of the matching layer corresponds to a second thickness of the piezoelectric layer; the first thickness is greater than the second thickness, and the first acoustic velocity is less than the second acoustic velocity.

One of the embodiments of the present specification further provides a method of preparing a matching layer, the method including: configuring a first component and a second component according to target acoustic impedance and target sound velocity gradient distribution which are required to be achieved by a matching layer; respectively arranging the first component and the second component at corresponding preset positions; and curing at a preset temperature for a preset time to obtain the matching layer.

In some embodiments, the predetermined temperature is in the range of 20 ℃ to 100 ℃ and the predetermined time period is in the range of 2h to 48h.

The components with different sound velocities in the matching layer are filled at different positions, so that the sound velocities of the matching layer are distributed in a gradient manner in at least one direction (such as the elevation angle direction of the matching layer), the transmissivity of the matching layer to sound waves with different frequencies is improved, and the bandwidth of the ultrasonic transducer is increased.

Drawings

The present description will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals refer to like structures, wherein:

FIG. 1 is a schematic structural diagram of an ultrasound transducer in accordance with some embodiments herein;

FIG. 2 is a schematic perspective view of a first ultrasonic transducer according to some embodiments of the present description;

FIG. 3A is a schematic structural diagram of a second type of ultrasonic transducer, shown in accordance with some embodiments herein;

FIG. 3B is a schematic perspective view of a second type of ultrasonic transducer, according to some embodiments herein;

fig. 4 is an exemplary flow chart of a method of making a matching layer according to some embodiments shown herein.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the present description, and that for a person skilled in the art, the present description can also be applied to other similar scenarios on the basis of these drawings without inventive effort. Unless otherwise apparent from the context, or stated otherwise, like reference numbers in the figures refer to the same structure or operation.

It should be understood that "system", "apparatus", "unit" and/or "module" as used herein is a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" are intended to cover only the explicitly identified steps or elements as not constituting an exclusive list and that the method or apparatus may comprise further steps or elements.

Flow charts are used in this description to illustrate operations performed by a system according to embodiments of the present description. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, the various steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

In some embodiments, the medical device may include an image processor and an ultrasound transducer. The ultrasonic transducer can convert electric energy into ultrasonic waves to be emitted into a human body, and convert the ultrasonic waves (such as echo signals) reflected by the human body into electric signals, and the electric signals corresponding to the echo signals can reflect the state of internal organs of the human body. An image processor is coupled to the ultrasound transducer, and the image processor can receive the electrical signal from the ultrasound transducer, and the electrical signal is processed by the image processor to obtain a corresponding image (e.g., a B-mode ultrasound image).

The image processor may be a device that processes the received signals to obtain an image, and in some embodiments, the image processor may include a plurality of processing units that may process the electrical signals from the ultrasound transducer to obtain a processed image.

The present specification describes an ultrasound transducer that can use the piezoelectric effect to realize the conversion between ultrasound and electrical energy, so as to be applied to various service scenarios using ultrasound for measurement, for example, the ultrasound transducer can be applied to medical imaging equipment, and can output medical images according to ultrasound returned by an object to be measured (e.g., human tissue, etc.); for another example, the ultrasonic transducer can be applied to underwater monitoring equipment to obtain a corresponding underwater image according to ultrasonic waves returned by an underwater object.

In some embodiments, the ultrasound transducer may include a matching layer that may transmit ultrasound waves generated by the ultrasound transducer to the object to be measured and transmit ultrasound waves generated by the human body to the piezoelectric layer. However, the matching layer is usually configured as the same material and has a uniform thickness, which causes the wavelength of the ultrasonic waves with different frequencies in the matching layer to be different, so that the matching layer is difficult to satisfy the transmission of the ultrasonic waves with different frequencies, and the bandwidth of the ultrasonic transducer is limited.

The present specification provides ultrasonic transducers having components with different acoustic velocities disposed in matching layers such that the acoustic velocities of the matching layers are graded in at least one direction (e.g., an elevation direction of the matching layers). Since the transmittance of the matching layer is affected by the ratio of the thickness of the matching layer to the wavelength of the ultrasonic wave, and the wavelength of the ultrasonic wave is related to the sound velocity of the matching layer and the frequency of the ultrasonic wave. Under the condition that the thickness distribution of the piezoelectric layers is unequal, the frequencies of ultrasonic waves generated by different areas of the piezoelectric layers are different, the wavelengths of the ultrasonic waves with different frequencies in different components can be the same through the gradient distribution of the sound velocity of the matching layers, and the ratio of the thickness of the matching layers in different areas to the wavelength of the ultrasonic waves can approach or reach an ideal value when the thicknesses of the different areas of the matching layers are the same, so that the transmissivity of the matching layers to the acoustic waves with different frequencies is improved, and the bandwidth of the ultrasonic transducer is increased.

It should be understood that the application scenarios of the ultrasound transducer of the present application are merely some examples or embodiments of the present application, and it is obvious for those skilled in the art that the present application can also be applied to other similar scenarios according to the drawings without inventive effort.

The ultrasonic transducer according to the embodiment of the present application will be described in detail with reference to fig. 1 to 3B. It should be noted that the following examples are only for explaining the present application and do not constitute a limitation to the present application.

Fig. 1 is a schematic structural diagram of an ultrasound transducer 100 according to some embodiments herein. In some embodiments, as shown in fig. 1, the ultrasonic transducer 100 mainly includes a matching layer 110 and a piezoelectric layer 120, the matching layer 110 is disposed between the piezoelectric layer 120 and an object to be measured, the piezoelectric layer 120 can be acoustically matched with the object to be measured through the matching layer 110, and the piezoelectric layer 120 is used for converting ultrasonic waves and electric energy.

Matching layer 110 is a layered structure that couples (i.e., acoustically matches) the acoustic impedances of adjacent media. In some embodiments, the number of matching layers 110 may be one or more. The matching layer 110 may be configured according to actual requirements, and the embodiment is not limited herein. In some embodiments, the matching layer 110 can be disposed on the upper surface of the piezoelectric layer 120 by bonding, welding, stapling, or the like. For example, the lower surface of the matching layer 110 and the upper surface of the piezoelectric layer 120 are fixed by means of adhesion. In some embodiments, the matching layer 110 can also be formed on the basis of the piezoelectric layer 120, such that the formed matching layer 110 is disposed on the upper surface of the piezoelectric layer 120.

In some embodiments, the matching layer 110 may include at least one matching member. For example, as shown in fig. 1, the matching layer 110 may include a first matching member 110-1, a second matching member 110-2, and a third matching member 110-3. In some embodiments, the structure, material, or function of the different mating members may be different, such as the speed of sound may be different for the different mating members.

The speed of sound refers to the speed at which sound signals are transmitted in a certain medium. In some embodiments, the speed of sound of the matching layer 110 may be the speed at which ultrasound waves are transmitted in the matching layer 110. In the case where the matching layer 110 includes a plurality of matching members, the sound velocity of the matching layer 110 may be the sound velocity of the plurality of matching members of the matching layer 110. In some embodiments, the acoustic velocities of the different mating members of the matching layer 110 may be the same or different, for example, as shown in figure 1, the acoustic velocity of the first mating member 110-1 and the acoustic velocity of the third mating member 110-3 may be the same, and the acoustic velocity of the second mating member 110-2 may be different from the acoustic velocities of the first mating member 110-1 and the third mating member 110-3, respectively. In some embodiments, different members may employ components having different speeds of sound, such that the speeds of sound of the different members are different.

The composition of the matching layer 110 may be a material having acoustic properties. In some embodiments, the matching layer 110 may include at least a first component and a second component. Wherein the first component has a first sound velocity, the second component has a second sound velocity, and the first component and the second component are respectively filled at different positions of the same plane of the ultrasonic transducer 100, so that the sound velocity of the matching layer 110 is distributed in a gradient manner in at least one direction.

In some embodiments, the first component and the second component may each comprise a plurality of mating members such that the plurality of mating members differ in acoustic velocity. For example, as shown in fig. 1, the first matching member 110-1 and the third matching member 110-3 can adopt a first composition, and the second matching member 110-2 can adopt a second composition, so that the first matching member 110-1 and the third matching member 110-3 have a first sound velocity, and the second matching member 110-2 has a second sound velocity. In some embodiments, the first component and the second component are filled in the same plane of the ultrasound transducer 100, so that a plurality of matching members are disposed in the same plane of the ultrasound transducer 100, and constitute the matching layer 110 of the ultrasound transducer 100. In some embodiments, the first and second components may also be filled in one or more planes of the ultrasound transducer 100 to produce one or more matching layers 110.

In some embodiments, the at least one direction may include a length direction and/or a thickness direction of the piezoelectric array elements of the piezoelectric layer 120. The length direction of piezoelectric array element can refer to the direction that is on a parallel with the first side of the horizontal plane projection of piezoelectric array element, and wherein, the horizontal plane projection of piezoelectric array element can include first side and second side, and first side is longer than the second side. The thickness direction of the piezoelectric array element can be perpendicular to the horizontal plane of the piezoelectric array element. Illustratively, the at least one direction may include a Y-axis direction (Y-axis direction shown in fig. 1) and/or a Z-axis direction in three-dimensional coordinates XYZ, wherein the three-dimensional coordinates are a coordinate system having an origin at an intersection of a first side and a second side of the piezoelectric array element, an X-axis in a width direction of the piezoelectric array element, a Y-axis in a length direction of the piezoelectric array element, and a Z-axis in a thickness direction of the piezoelectric array element. Reference may be made to other embodiments of the present description, such as fig. 2 and its associated description, with respect to a detailed description of at least one direction and three-dimensional coordinates. For a detailed description of the piezoelectric array elements, reference may be made to the associated description in piezoelectric layer 120 described below.

A gradient distribution may refer to a stepwise or gradual distribution of sound speed in one or more directions, such as a monotonically decreasing or increasing, a normal distribution, and so forth. For example, in some embodiments, the gradient profile of the sound speed of the matching layer 110 may include that the sound speed monotonically decreases or increases from the first side to the second side of the matching layer 110, decreases or increases from the center to the peripheral side of the matching layer 110, or the like. The first side and the second side of the plane may be different sides of the plane, and the first side and the second side may be two sides corresponding to each other. In some embodiments, the first lateral second side direction may include a width direction (Y direction as shown in fig. 1) of the matching layer 110. In some embodiments, the gradient distribution of the sound velocity of the matching layer 110 may also correspond to the thickness distribution of the piezoelectric layer 120, and specific contents may refer to the related description of the piezoelectric layer 120, which is not described herein again.

In some embodiments, when the matching layers 110 are multiple layers, different matching layers 110 may have the same sound velocity gradient distribution or different sound velocity gradient distributions. Further, there may be at least one matching layer 110 of the plurality of matching layers 110 that is not in an acoustic velocity gradient distribution.

Since the frequency of the ultrasonic waves is inversely proportional to the thickness of the piezoelectric layer 120, the thickness distribution of the piezoelectric layer 120 is not uniform, and the frequency of the ultrasonic waves generated in different regions of the piezoelectric layer 120 is different. Since the sound velocity distribution of the matching layer 110 affects the wavelength and frequency of the ultrasonic wave, the formula is as follows: λ = c/f, where λ represents the wavelength of the ultrasonic wave, c represents the sound velocity of the matching layer, and f represents the frequency of the ultrasonic wave. If the matching layer 110 with uniform sound velocity distribution is adopted, the corresponding ultrasonic waves have different wavelengths when different ultrasonic frequencies are transmitted through the matching layer 110. Also, the ratio of the thickness of the matching layer 110 to the wavelength of the ultrasonic wave can affect the transmittance, for example, when the thickness of the matching layer 110 is an odd multiple of a quarter wavelength of the ultrasonic wave in the matching layer 110, the transmittance can be ideally 100%. For ultrasonic waves of different frequencies, if the wavelengths of the ultrasonic waves in the matching layer 110 are different, the ratio of the thickness of each point of the matching layer 110 to the wavelength of the ultrasonic waves changes, so that the acoustic matching of the matching layer is poor, and the transmittance of the matching layer is reduced.

In some embodiments of the present disclosure, for the ultrasonic waves of different frequencies, the matching layer 110 may have a gradient distribution of sound velocities by filling components having different sound velocities at different positions, so that the ultrasonic waves of different frequencies can be controlled to have the same wavelength in the matching layer 110, thereby improving the transmittance of the matching layer 110 for the ultrasonic waves and increasing the bandwidth of the ultrasonic transducer 100.

In some embodiments, the first and second components in the matching layer 110 may have the same acoustic impedance and/or the same thickness.

The acoustic impedance may be used to reflect the resistance that sound needs to overcome through the medium. In some embodiments, the acoustic impedance of the composition may reflect the resistance that the ultrasound wave needs to overcome when passing through the matching layer. For example, the greater the acoustic impedance of the components, the greater the resistance that the ultrasound wave needs to overcome when propagating through the matching layer; conversely, the lower the acoustic impedance of the components, the less resistance the ultrasound waves need to overcome when propagating through the matching layer.

It should be noted that the difference in acoustic impedance between two objects may reflect whether the two objects are acoustically matched. If the difference in acoustic impedance between the two objects exceeds an acoustic impedance threshold, then an acoustic mismatch can be determined, the more energy the ultrasound reflects at the boundary of the two media; conversely, if the difference in acoustic impedance between two objects does not exceed the acoustic impedance threshold, then acoustic matching can be determined, with less energy being reflected by the ultrasound wave at the boundary between the two media.

In some embodiments of the present disclosure, by designing the first component and the second component to have the same acoustic impedance, the different components can be acoustically matched, and the different matching members (e.g., the first matching member 110-1, the second matching member 110-2, and the third matching member 110-3) in the matching layer 110 can be acoustically matched, so as to reduce energy consumed when the ultrasonic wave passes through the matching layer 110, thereby improving the transmission effect of the matching layer 110 on the ultrasonic wave.

In some embodiments, when there are multiple matching layers 110, different matching layers 110 may have the same acoustic impedance or different acoustic impedances. Illustratively, the first matching layer may have an acoustic impedance of 8MRayl to 8.5Mrayl, the second matching layer may have an acoustic impedance of 4MRayl to 6MRayl, and the third matching layer may have an acoustic impedance of 2MRayl to 3 MRayl. Further, in some embodiments, some matching layers 110 of the plurality of matching layers 110 may have the same acoustic impedance and other partial matching layers 110 may have different acoustic impedances.

Since the acoustic impedance of a component can be affected by its density and speed of sound. In some embodiments, where different components of matching layer 110 have different acoustic velocities, the density of the components may be adjusted to ensure that the different components have the same acoustic impedance. For example, if the sound velocity of the first component is greater than the sound velocity of the second component, the density of the first component may be decreased or the density of the second component may be increased so that the first component and the second component may have the same acoustic impedance.

In some embodiments, the different components of the matching layer 110 may have the same thickness, such that each spot of the matching layer 110 may be equal in thickness. For example, as shown in fig. 1, the distances (i.e., thicknesses) between two points of the matching layer 110 in the Z-axis direction are equal. Illustratively, the matching layer may have a thickness of at least one of 100um, 150um, 200um, etc.

In some embodiments of the present disclosure, by setting the thicknesses of different components of the matching layer 110 to be equal, the thickness of the matching layer 110 does not need to be specially processed according to the structure of the piezoelectric layer 120, so that the difficulty of the processing process of the ultrasonic transducer 100 can be reduced.

Since the gradient distribution of the acoustic velocity of the matching layer 110 corresponds to the thickness distribution of the piezoelectric layer 120, in some embodiments, the acoustic velocity range of the matching layer 110 can be designed according to the structure of the piezoelectric layer 120 (e.g., the thickness range of different regions of the piezoelectric layer 120). In some embodiments, the first acoustic velocity of the first constituent or the second acoustic velocity of the second constituent may range from 1400m/s to 3500m/s. For a detailed description of the thickness distribution of the piezoelectric layer 120, reference may be made to the description of the piezoelectric layer 120, which is not repeated herein.

It should be noted that the first sound velocity and the second sound velocity are also only used as examples, and are not limited to the order of the sound velocities of the matching layer 110, and only indicate that different components in the matching layer 110 have different sound velocities, and may also have a third sound velocity, a fourth sound velocity, and the like, which is not specifically limited in this embodiment.

The component is an inert substance used to adjust the physical and/or chemical properties of the device, such as by changing the acoustic velocity of the device by adjusting the elastic modulus, density, etc. In some embodiments, the components may include inorganic materials and/or organic materials, and the like. The acoustic speed of the matching layer can be adjusted by varying the type, proportion, size and/or structure of the materials in the composition. For example, the organic material may include organic materials such as epoxy resin, silicone rubber, fluorine rubber, nitrile rubber, styrene-butadiene rubber, ethylene-propylene-diene monomer rubber, thermoplastic SBS elastomer plastic expanded microspheres, etc., and the inorganic material may include inorganic non-metallic compounds (e.g., glass, ceramic), metals (e.g., tungsten, copper, iron, etc.), and/or metal oxides (e.g., tungsten trioxide, aluminum trioxide, iron oxide, etc.), etc.

In some embodiments, the different components may include different types of materials and/or different structures such that the different components have different characteristics (e.g., speed of sound, density, etc.). In some embodiments, the first component and the second component may have at least one different species; alternatively, the first and second components may have the same species, at least one of which may differ in the proportions, size, and/or structure of the first and second components.

In some embodiments, the sound velocity of the first component and/or the second component can be varied by introducing one or more different species into the first component and/or the second component. In some embodiments, the sound velocity of the first component and/or the second component may also be varied by adjusting the ratio, size, or structure of one or more of the same species. Further, in some embodiments, the proportions, sizes, or configurations of the different species in the first component and/or the second component may also be adjusted to further adjust the sound speed of the first component and/or the second component.

Illustratively, the first component and the second component may each include an epoxy resin. In order to make the first component and the second component have different sound velocities, it is possible to design to introduce a liquid resin (such as a rubber-like liquid resin) into the first component to reduce the sound velocity of the first component. It is also contemplated that the incorporation of a metal oxide filler in the second component may be designed to increase the acoustic velocity of the second component. Moreover, the sound velocity of the first component can be further adjusted by adjusting the ratio of the liquid resin in the first component; or the sound velocity of the second component is further adjusted by adjusting the proportion, the size and the structure of the metal oxide filler in the second component.

In the embodiment of the present application, by designing the species, the proportion, the size, the structure, and the like of the substances in the components, different components can have different sound velocities, so that the gradient distribution of the sound velocity of the matching layer 110 is realized, and the transmittance of the matching layer 110 to ultrasonic waves of different frequencies is improved.

The density of the components can also be influenced by the type and proportion of the substances in the components. In some embodiments, the density of the first component and/or the second component can be adjusted by adjusting the type and the proportion of the substances in the first component and/or the second component, so that the first component and the second component have the same acoustic impedance.

For example, when the sound velocity of the first component is reduced, a substance (e.g., a metal or the like) having a higher density and a smaller influence on the sound velocity increase may be introduced into the first component to increase the density of the first component so that the first component and the second component have the same acoustic impedance. When the sound velocity of the second component is increased, a substance (e.g., an inorganic nonmetallic compound of a hollow structure or the like) having a lower density and a smaller influence on the reduction of the sound velocity may be introduced into the second component to reduce the density of the second component so that the first component and the second component have the same acoustic impedance.

In some embodiments, the first and second components may be disposed in the ultrasound transducer 100 by a cast molding, potting injection molding, or the like process to form the matching layer 110. In some alternative embodiments, after the matching layer 110 is prepared by the above-mentioned process, the matching layer 110 may be disposed on the piezoelectric layer 120 by bonding, welding, nailing, or the like. In some alternative embodiments, the matching layer 110 can be prepared on the upper surface of the piezoelectric layer 120 by the above process, so that the matching layer 110 can be attached to the piezoelectric layer 120 after molding. In some embodiments, the matching layer 110 may select different components based on different structures (e.g., a thickness gradient distribution, etc.) of the piezoelectric layer 120, so that the sound velocity of the matching layer 110 is in a gradient distribution, and thus the matching layer 110 may have a better transmission effect on ultrasonic waves of different frequencies, and thus, acoustic matching between piezoelectric layers 120 of different structures and an object to be measured is achieved.

It should be noted that the first component and the second component are only used as examples, and are not limited to the order of the components in the matching layer 110, and only indicate that different components exist in the matching layer 110, and the matching layer 110 may further have more other components, such as a third component, a fourth component, and the like, which is not specifically limited in this embodiment. In some embodiments, other components of the matching layer 110 may also have the same properties and functions as the first and second components.

In some embodiments, the sound velocity and/or density of the first and second components may be adjusted using different properties of different species. In some embodiments, the first component and/or the second component may include an epoxy, the material of the first component and/or the second component further including at least one of a material of a first range of acoustic speeds, a material of a second range of acoustic speeds, a material of a first density range, and a material of a second density range, the first range of acoustic speeds being less than the second range of acoustic speeds, the first density range being greater than the second density range.

The epoxy is a thermosetting resin that has a good transmission effect for the ultrasonic waves, and in some embodiments, the epoxy may be a base for the first component and/or the second component, providing an initial sound velocity for the first component and the second component. Illustratively, the epoxy has an acoustic velocity of 2730m/s and a density of 1.15g/cm3.

Further, in some embodiments, the first range of acoustic speeds may be less than the acoustic speed of the epoxy and the second range of acoustic speeds may be greater than the acoustic speed of the epoxy. In some embodiments, the first density range may be greater than the density of the epoxy resin and the second density range may be less than the density of the epoxy resin. That is, adding a material in a first range of sound velocities to the epoxy may be used to reduce the sound velocity of the constituent, adding a material in a second range of sound velocities may be used to increase the sound velocity of the constituent, adding a material in a first range of densities may be used to increase the density of the constituent, and adding a material in a second range of densities may be used to reduce the density of the constituentAnd (4) degree. Illustratively, in some embodiments, the first speed of sound ranges from 800m/s to 2000m/s, the second speed of sound ranges from 2800m/s to 11000m/s, and the first density ranges from 3g/cm ³ -20g/cm ³ The second density range is 0.1g/cm ³ -0.8g/cm ³ 。

In some embodiments, the first component and the second component may employ the same kind or different kinds of materials among a material of the first sound velocity range, a material of the second sound velocity range, a material of the first density range, and a material of the second density range, so that the first component and the second component may have different sound velocities by changing the proportion and content of the materials in the different components. Further, in some embodiments, the first component and the second component may also be made to have the same acoustic impedance by varying the proportion and amount of the first density range material and the second density range material in the different components.

It should be noted that the materials of the first and second density ranges may also have different acoustic velocities, but the material of the second acoustic velocity range has less influence on the acoustic velocity than the material of the first acoustic velocity range. In some embodiments, the first component and the second component may include only the first density range of materials and/or the second density range of materials, and the first component and the second component may have different speeds of sound by varying proportions and amounts of the first density range of materials and/or the second density range of materials.

In some embodiments, the material of the first range of acoustic speeds may comprise rubber, the material of the second range of acoustic speeds may comprise metal oxides and/or inorganic non-metallic compounds of solid structure, the material of the first range of densities may comprise metal, and the material of the second range of densities may comprise inorganic non-metallic compounds of hollow structure and/or expanded plastic microspheres. Since the density of rubber is similar to that of epoxy and has the property of low acoustic speed, in some embodiments rubber has less effect on density and more effect on acoustic speed and can be used to reduce the acoustic speed of the components. For example, the sound velocity of ultrasonic waves in rubber is about 950m/s to 2400m/s, and the sound velocity of the components can be reduced by adding rubber to the epoxy resin (i.e., the base of the components).

In some embodiments, metals have less of an effect on sound speed and greater of an effect on density and may be used to increase the density of the composition. In some embodiments, if the density of the added metal is lower, then the volume fraction of the added metal needs to be greater, so that the addition of a larger volume fraction of the lower density metal can further increase the sound velocity of the composition compared to other higher density metals. In some embodiments, the metal oxide has a smaller effect on density and a larger effect on sound speed, and may be used to increase the sound speed of the composition.

In some embodiments, inorganic non-metallic compounds of hollow structure (e.g., hollow ceramic beads, hollow glass beads) have less effect on the speed of sound and greater effect on density and may be used to reduce the density of the components. In some embodiments, inorganic non-metallic compounds of solid construction (e.g., solid ceramic beads, solid boron carbide beads, etc.) have a lesser effect on density and a greater effect on sound speed and may be used to increase the sound speed of the composition.

The plastic expanded microspheres have small influence on sound velocity and large influence on density, and the density of the plastic expanded microspheres is smaller than that of the epoxy resin. In some embodiments, plastic expanded microspheres may be used to reduce the density of the components. For example, the density of the expanded plastic microspheres may range from about 0.1g/cm ³ -0.13g/cm ³ The addition of plastic expanded microspheres to the epoxy resin (i.e., the base of the component) can reduce the density of the component.

In some embodiments, the sound velocity of the component may also be adjusted by adjusting the microsphere size of the material, which increases with increasing microsphere size. In some embodiments, the metal, metal oxide, or inorganic non-metallic compound may be in the form of a powder or microspheres (also referred to as microbeads) or the like for incorporation into the epoxy resin.

In some embodiments, the material of the first component may include epoxy, rubber, and metal, the material of the second component may include epoxy, metal oxide, and an inorganic non-metallic compound of a hollow structure, the first acoustic velocity of the first component is less than the second acoustic velocity of the second component, and the first component and the second component have the same acoustic impedance. That is, the addition of rubber having a low acoustic velocity and metal having a high density to the epoxy resin can provide the first component with low acoustic velocity and high density. The addition of the metal oxide with high sound velocity and the inorganic nonmetal compound with low density and hollow structure in the epoxy resin can make the second component have the characteristics of high sound velocity and low density, so that the first sound velocity of the first component is lower than the second sound velocity of the second component. Since the acoustic impedances of the components are affected by their density and speed of sound, further, in some embodiments, the low speed, high density first component and the high speed, low density second component may have the same acoustic impedance.

Several exemplary species of the foregoing species are provided below, respectively, to describe in detail specific implementations of the components.

In some embodiments, the epoxy resin may include at least one of a bisphenol a type epoxy resin, a bisphenol F type epoxy resin; the rubber can comprise at least one of thermoplastic SBS elastomer, nitrile rubber, butyl rubber, styrene butadiene rubber, ethylene propylene diene monomer rubber, silicon rubber and fluororubber; the metal comprises at least one of tungsten, copper, iron and lead; the metal oxide may include at least one of tungsten trioxide, iron oxide, aluminum oxide, zinc oxide, magnesium oxide; the inorganic non-metallic compound may include at least one of glass, ceramic, boron carbide.

In some embodiments, the epoxy resin content may be 100g; the content of material of the first sound speed range may be less than or equal to 60g, or the content of material of the second sound speed range may be less than or equal to 130g, or the content of material of the first density range may be less than or equal to 500g, or the content of material of the second density range may be less than or equal to 20g. Further, in some embodiments, the content of rubber may be less than or equal to 60g, or the content of metal may be less than or equal to 500g, the content of metal oxide may be less than or equal to 130g, or the content of inorganic non-metallic compound of solid structure may be less than or equal to 130g, or the content of inorganic non-metallic compound of hollow structure may be less than or equal to 20g, or the content of plastic expanded microspheres may be less than or equal to 20g.

It should be noted that the above-mentioned materials are provided as examples only, and the components may also include other materials with similar functions and properties. For specific implementation of the components, reference may be made to other contents in this specification, and details are not described herein again.

The piezoelectric layer 120 is a layered structure fabricated using a device having a piezoelectric effect. In some embodiments, the piezoelectric wafer may be made of one or more materials selected from a piezoelectric crystal (e.g., quartz crystal, lithium iodate, etc.), a piezoelectric semiconductor (e.g., cadmium sulfide, zinc oxide, etc.), a piezoelectric ceramic, a piezoelectric composite material, or a piezoelectric polymer, and the embodiments of the present invention are not limited thereto. In some embodiments, piezoelectric layer 120 can comprise a piezoelectric device in the shape of a wafer, strip, rod, cylinder, or the like.

In some embodiments, piezoelectric layer 120 can include one or more piezoelectric wafers, where a piezoelectric wafer can be a device having a piezoelectric effect. In some embodiments, as shown in fig. 1, a piezoelectric wafer may serve as piezoelectric layer 120. In some embodiments, in the case that the piezoelectric wafer is a plurality of piezoelectric wafers, the piezoelectric layers 120 can be made of a plurality of piezoelectric wafers by stacking, such as vertical stacking, horizontal arrangement, and stacking with multiple arrays side by side.

In some embodiments, piezoelectric layer 120 may include one or more piezoelectric array elements. The piezoelectric array element may be an element in an array structure of the piezoelectric layer 120, which may be divided according to a minimum unit of operation of the piezoelectric layer 120. In some embodiments, the array structure of the piezoelectric layer 120 may include a single array, a double array, a triple array, a quadruple array, a quintuple array, and other multi-array side-by-side structures, and the number of the arrays is not particularly limited in the present application.

The array may be a collection of piezoelectric array elements in the same column stacked along the width of the array elements. In some embodiments, the width direction of the piezoelectric array element may refer to a direction parallel to a second side of the horizontal projection of the piezoelectric array element, wherein the first side of the horizontal projection of the piezoelectric array element is longer than the second side. Illustratively, the width direction of the piezoelectric array elements may be the X-axis direction of the three-dimensional coordinate XYZ (the X-direction shown in fig. 2 described below). It should be noted that the stacking direction of the foregoing array is only used as an illustration, and stacking along other directions may also be performed, and details are not described here.

In some embodiments, the thickness of the piezoelectric layer 120 can be related to the thickness of the piezoelectric wafer. In some embodiments, where the piezoelectric wafers are stacked in a horizontal arrangement or in multiple arrays side by side, the thickness of the piezoelectric layer 120 may be equal to the thickness of the piezoelectric wafers. For example, as shown in fig. 1, the piezoelectric layer 120 comprises a piezoelectric wafer, and the thickness of the piezoelectric layer 120 can be equal to the thickness of the piezoelectric wafer.

In some embodiments, the thickness of the piezoelectric layer 120 can vary. The thickness of the piezoelectric layer 120 may vary, meaning that the thickness of the piezoelectric layer includes 2 or more than 2 thicknesses. In some embodiments, the thickness of the piezoelectric layer 120 can include a first thickness and a second thickness, the first thickness being different than the second thickness. For example, as shown in fig. 1, the thickness of the middle portion of piezoelectric layer 120 (i.e., the first thickness) can be less than the thickness of both ends of piezoelectric layer 120 (i.e., the second thickness). The first thickness and the second thickness do not limit the number of thicknesses of the piezoelectric layer 120, but only indicate that the piezoelectric layer has different thicknesses. The thickness of the piezoelectric layer 120 may also include other thicknesses, such as a third thickness, a fourth thickness, and the like, which is not particularly limited in this embodiment.

In some embodiments, the thickness profile of piezoelectric layer 120 can be a gradient thickness profile. In some embodiments, the thickness distribution of the piezoelectric layer 120 can include a thickness that monotonically increases or monotonically decreases from the first side to the second side of the piezoelectric layer 120, that increases or decreases from the center of the piezoelectric layer 120 to the periphery side, and the like. Wherein the first side and the second side of the piezoelectric layer 120 can be different sides of the piezoelectric layer 120, and the first side and the second side can be two sides corresponding to each other. In some embodiments, the first lateral second side may comprise a length direction (e.g., the Y direction shown in fig. 1) of the piezoelectric array element. In some embodiments, the monotonic increase or monotonic decrease from the first side to the second side of the piezoelectric layer 120 can include a monotonic increase or monotonic decrease that is stepped, rectilinear, or the like. In some embodiments, the increase or decrease from the center of the piezoelectric layer 120 to the peripheral side can include a step, a straight line, a curve, a parabola, or the like, in which the center increases or decreases to the peripheral side. In some embodiments, the thickness distribution of the piezoelectric layer 120 may be set according to actual requirements, and the embodiment is not limited herein.

Since the different thicknesses of the piezoelectric layer 120 may cause different frequencies of the generated ultrasonic waves, in some embodiments, the gradient distribution of the sound velocity of the matching layer 110 may correspond to the thickness distribution of the piezoelectric layer 120 to control the ultrasonic waves of different frequencies to have the same wavelength in the matching layer 110, thereby improving the transmissivity of the matching layer 110 to the ultrasonic waves and increasing the bandwidth of the ultrasonic transducer 100.

In some embodiments, the speed of sound of the matching layer 110 may be inversely proportional to the thickness of the piezoelectric layer 120 at the corresponding location. Illustratively, when the thickness distribution of the piezoelectric layer 120 monotonically increases from the first side to the second side of the piezoelectric layer 120, the sound velocity distribution of the matching layer 110 may also monotonically decrease from the first side to the second side of the matching layer 110. When the thickness distribution of the piezoelectric layer 120 is monotonically decreasing from the first side to the second side of the piezoelectric layer 120, the acoustic velocity distribution of the matching layer 110 may also be monotonically increasing from the first side to the second side of the matching layer 110. When the thickness distribution of the piezoelectric layer 120 is gradually increased or decreased from the center of the piezoelectric layer 120 toward the peripheral side, the sound velocity distribution of the matching layer 110 may also be gradually decreased or increased from the center of the matching layer 110 toward the peripheral side.

In some embodiments, the gradient profile of the acoustic velocity of the matching layer 110 corresponds to the thickness profile of the piezoelectric layer 120, which may include: the gradient profile of the acoustic velocity of the matching layer 110 can have an inverse relationship with the thickness profile of the piezoelectric layer 120. In some embodiments, the first acoustic velocity of the first component of the matching layer 110 corresponds to a first thickness of the piezoelectric layer 120, and the second acoustic velocity of the second component of the matching layer 110 corresponds to a second thickness of the piezoelectric layer 120; the first thickness is larger than the second thickness, and the first sound velocity is smaller than the second sound velocity.

For example, as shown in fig. 1, in the Y-axis direction, the middle portion of the piezoelectric layer 120 corresponds to the second matching member 110-2 of the matching layer, the left portion of the piezoelectric layer corresponds to the first matching member 110-1 of the matching layer, and the right portion of the piezoelectric layer corresponds to the third matching member 110-3 of the matching layer. The first member 110-1 and the third member 110-3 can be a first component, and the second member 110-2 can be a second component. As shown in fig. 1, the matching layer 110 is of equal thickness at each point, and in order to make the wavelength of the ultrasonic waves the same in the matching layer 110, the acoustic velocity of the components in the matching layer 110 may be inversely related to the thickness of the piezoelectric layer 120. The first acoustic velocity of the first component can be designed to be less than the second acoustic velocity of the second component so that the acoustic velocity of the second mating member 110-2 of the matching layer 110 is higher than the acoustic velocities of the first and third mating members 110-1 and 110-3 of the matching layer. The second acoustic velocity c2 of the second matching member 110-2 of the matching layer 110 may correspond to a first thickness of the piezoelectric layer 120, and the first acoustic velocity c1 of the first matching member 110-1 of the matching layer and the third matching member 110-3 of the matching layer may correspond to the first thickness of the piezoelectric layer, where the first thickness is greater than the second thickness, so that a gradient distribution of the acoustic velocity of the matching layer 110 decreases from the center to the circumferential side, corresponding to a gradient distribution of the thickness of the piezoelectric layer 120 increasing from the center to the circumferential side.

In some embodiments of the present disclosure, a gradient distribution of the sound velocity of the matching layer 110 may be set according to the thickness distribution of the piezoelectric layer 120, so that the ultrasonic waves of different frequencies have the same wavelength in the matching layer 110, thereby improving the transmittance of the matching layer 110 for the ultrasonic waves and increasing the bandwidth of the ultrasonic transducer 100.

In some embodiments, piezoelectric layer 120 can be of a different structure and/or composition. For example, the shape of the piezoelectric layer 120 can include a variety of shapes, and the like. The piezoelectric layer 120 can be configured according to practical requirements, and the embodiment is not limited herein.

In some embodiments, the thickness of the piezoelectric layer 120 can be the same at each point, and the ultrasound transducer 100 can achieve the transmission and reception of ultrasound waves of different frequencies through the thickness distribution of other structures (such as a high impedance backing in the backing layer 130 described below). Correspondingly, in some embodiments, the sound speed distribution of the matching layer 110 may correspond to the thickness distribution of the high-impedance backing in the backing layer 130, and the specific implementation manner thereof may refer to the following description related to fig. 3A to 3B, which is not described herein again.

In some embodiments, as shown in fig. 1, the ultrasonic transducer 100 further comprises a backing layer 130, and the backing layer 130 may be disposed on a side of the piezoelectric layer 120 away from the matching layer 110.

The backing layer 130 can be a layered structure that absorbs ultrasonic waves generated by the piezoelectric layer 120 in a direction opposite to the direction of the object to be measured. In some embodiments, the backing layer may comprise a plurality of materials, such as a combination of one or more materials, such as metals, metal oxides, organic materials, and the like. In some embodiments, when the piezoelectric wafer of the piezoelectric layer 120 is stimulated to emit ultrasonic waves, a portion of the directionally propagating ultrasonic waves enter the backing layer, and are strongly reflected at the backing layer 130, with the strongly reflected ultrasonic waves propagating forward through the piezoelectric layer 120.

Fig. 2 is a perspective view of an ultrasound transducer 100 according to some embodiments herein.

In some embodiments, as shown in fig. 2, the ultrasound transducer 100 includes a matching layer 110, a piezoelectric layer 120, a backing layer 130, and an acoustic lens 140. In the Z-axis direction, the acoustic lens 140, the matching layer 110, the piezoelectric layer 120, and the backing layer 130 may be stacked from top to bottom.

In some embodiments, the ultrasound transducer 100 can further include an acoustic lens 140, the acoustic lens 140 and a side of the matching layer 110 distal from the piezoelectric layer 120. Among them, the acoustic lens 140 is an acoustic element that converges or diverges acoustic waves. In some embodiments, acoustic lens 140 may redirect, i.e., refract, the transmission of the ultrasonic waves, such that the waves converge or diverge. In some embodiments, the acoustic lens 140 may focus the ultrasonic waves emitted by the matching layer 110. The acoustic lens 140 is not particularly limited in the present application.

Fig. 3A is a schematic structural diagram of an ultrasound transducer 100 according to some embodiments herein, and fig. 3B is a schematic perspective structural diagram of the ultrasound transducer 100 according to some embodiments herein.

In some embodiments, as shown in fig. 3A-3B, the backing layer 130 can include a first impedance layer 130-1 and a second impedance layer 130-2, the first impedance layer 130-1 being connected to the second impedance layer 130-2, the first impedance layer 130-1 being connected to a surface of the piezoelectric layer 120 distal from the matching layer 110, the first impedance layer 130-1 having a higher impedance than the second impedance layer 130-2.

In some embodiments, when the piezoelectric wafer of the piezoelectric layer 120 is excited to emit an ultrasonic wave, a part of the ultrasonic wave propagating in the direction enters the first impedance layer 130-1, strong reflection may occur at the interface of the first impedance layer 130-1 and the second impedance layer 130-2, and the strongly reflected ultrasonic wave propagates forward through the piezoelectric layer 120. In some embodiments, the piezoelectric layer 120 and the first impedance layer 130-1 can be viewed as an equivalent oscillator, the resonant frequency of which is inversely proportional to the thickness of the first impedance layer 130-1.

In some embodiments, the backing layer 130 may comprise a plurality of materials. For example, the first impedance layer 130-1 may include a material having a high impedance and a small acoustic attenuation coefficient, such as a material of a metal, a metal oxide, or the like, or a mixture thereof. The second impedance layer 130-2 may include a material having a small impedance and a large acoustic attenuation coefficient, for example, an organic material or the like.

In some embodiments, the impedance of the first impedance layer 130-1 is 10 to 40 times the impedance of the second impedance layer 130-2. It should be noted that the impedance multiple is only used as an example, and the present application is not limited to this. In some embodiments of the present disclosure, the low impedance backing structure and the high impedance structure cooperate with each other to achieve the transmission and reception of ultrasonic waves of different frequencies by changing the thickness of the high impedance backing.

In some embodiments, the piezoelectric layer 120 is equal in thickness at each point, and the first resistive layer 130-1 may not be equal in thickness. Illustratively, the first resistive layer 130-1 may have a plurality of different thicknesses. In some embodiments, the thickness profile of the first resistive layer 130-1 may be a gradient thickness profile. In some embodiments, the thickness distribution of the first impedance layer 130-1 may include a thickness that monotonically increases or monotonically decreases from the first side to the second side of the first impedance layer 130-1, that increases or decreases from the center to the peripheral side of the first impedance layer 130-1, and so on. Wherein the first side and the second side of the first impedance layer 130-1 may be different side edges of the backing layer 130, and the first side and the second side may be two side edges corresponding to each other. In some embodiments, the first lateral second side of the first impedance layer 130-1 may comprise the width direction of the backing layer 130 (e.g., the Y direction as shown in fig. 3A-3B). In some embodiments, the monotonic increase or monotonic decrease from the first side to the second side of the first impedance layer 130-1 can include a monotonic increase or monotonic decrease that is stepped, rectilinear, or the like. In some embodiments, the increase or decrease from the center to the circumferential side of the first impedance layer 130-1 may include a center to the circumferential side increase or decrease in a stepwise manner, a straight line manner, a curved line manner, a parabolic manner, or the like. In some embodiments, the thickness distribution of the first resistance layer 130-1 may be set according to practical requirements, and the embodiment is not limited herein.

In some embodiments, the various structures of the ultrasound transducer may be connected by way of bonding. Illustratively, the matching layer 110, the piezoelectric layer 120, the first impedance layer 130-1, and the second impedance layer 130-2 may be bonded from top to bottom, thereby obtaining the ultrasonic transducer 100. In some embodiments, one or more cuts may be made to the bonded ultrasound transducer 100, resulting in a cut ultrasound transducer. In some embodiments, a first cut may be made to the bonded ultrasound transducer 100 to obtain a cut ultrasound transducer 100. Illustratively, as shown in fig. 3B, when the cutting direction is along the X-axis direction, the cutting positions may be left and right edges of the middle portion of the first resistance layer 130-1. In some embodiments, by cutting the bonded ultrasound transducer 100, four, five, etc. arrays of ultrasound transducers may also be obtained. In some embodiments, the cutting direction and the cutting position may be set according to actual requirements, and the embodiment is not limited herein.

In some embodiments, the piezoelectric layer 120 of the broadband area array ultrasound transducer may be a piezoelectric wafer, the piezoelectric array of the piezoelectric layer is obtained by cutting the piezoelectric wafer, the thicknesses of the points of the thickness of the piezoelectric layer 120 are equal, and the piezoelectric layer is a multi-array side-by-side structure, so that multiple processing on the piezoelectric wafer can be avoided, and the damage probability of the piezoelectric wafer is reduced.

In some embodiments, a second cut may also be made to the bond cut ultrasound transducer 100 to obtain a second cut ultrasound transducer 100. For example, as shown in fig. 3B, the cutting direction may be along the Y-axis direction, the cutting positions may be set to be equally spaced, and the ultrasonic transducer 100 with the broadband area array is obtained by bonding the acoustic lens 140 on the multi-array ultrasonic transducer after the bonding cutting.

In some embodiments of the present description, as shown in fig. 3B, piezoelectric layer 120 may include a first piezoelectric array element 120-1, a second piezoelectric array element 120-2, and a third piezoelectric array element 120-3. The thickness of the middle part of the first impedance layer 130-1 can be smaller than the thickness of the left part and the right part of the first impedance layer 130-1, and the frequency of the ultrasonic wave of the middle part of the second piezoelectric array element 120-2 bonded with the first impedance layer 130-1 is larger than the frequency of the ultrasonic wave of the left part and the right part of the first impedance layer 130-1 bonded with the first piezoelectric array element 120-1 and the third piezoelectric array element 120-3, so that the ultrasonic transducer can meet the requirements of transmitting and receiving ultrasonic waves with different frequencies, the longitudinal resolution and the sensitivity of an image can be improved, and the bandwidth of the ultrasonic transducer is increased to facilitate harmonic imaging.

In some embodiments, the piezoelectric layer 120 of the broadband area array ultrasound transducer 100 may be a piezoelectric wafer, the piezoelectric array of the piezoelectric layer is obtained by cutting the piezoelectric wafer, the thicknesses of the points of the piezoelectric layer 120 are equal, and the piezoelectric array is a multi-array side-by-side structure, so that multiple processing on the piezoelectric wafer can be avoided, and the damage probability of the piezoelectric wafer is reduced. When the thicknesses of the points of the piezoelectric layer 120 are equal, the thickness of the first impedance layer 130-1 may not be equal, so that the acoustic signal that can be emitted by the ultrasonic transducer 100 is still a signal wave of a range of frequencies. Correspondingly, in some embodiments, the gradient of the speed of sound of the matching layer 110 is graded in at least one direction. Through the gradient distribution of the sound velocity of the matching layer, the wavelengths of the ultrasonic waves with different frequencies in the matching layers with different components are the same, and the ratio of the thickness of the matching layer to the wavelength of the ultrasonic waves in different areas can approach or reach an ideal value when the thicknesses of different areas of the matching layer are the same, so that the transmissivity of the sound waves with different frequencies is improved, and the bandwidth of the ultrasonic transducer is increased.

In some embodiments, the gradient profile of the speed of sound of the matching layer 110 corresponds to the thickness profile of the first impedance layer 130-1. In some embodiments, the thickness distribution of the first impedance layer 130-1 may include a thickness that monotonically increases or monotonically decreases from the first side to the second side of the first impedance layer 130-1, that increases or decreases from the center to the peripheral side of the first impedance layer 130-1, and so on. Accordingly, the gradient distribution of the sound speed of the matching layer 110 may include that the sound speed monotonically decreases or monotonically increases from the first side to the second side of the matching layer 110, decreases or increases from the center of the matching layer 110 to the peripheral side, or the like.

In the embodiment of the application, the impedance layer is arranged to strongly reflect the back sound wave, so that the ultrasonic transducer can transmit the reflected back sound wave while transmitting the sound signal, the overall strength of the transmitted signal is increased, and the sensitivity of the transducer is improved (because the strength of the forward-transmitted signal is increased). And the thickness distribution of the impedance layer can increase the frequency range of the fundamental wave of the sound signal, thereby increasing the bandwidth of the ultrasonic transducer.

Fig. 4 is an exemplary flow chart of a method of fabricating a piezoelectric layer according to some embodiments of the present description.

Referring to fig. 4, in some embodiments, flow 400 may include:

step 410, configuring a first component and a second component according to target acoustic impedance and target sound velocity gradient distribution which need to be achieved by the matching layer.

The first component and the second component are materials having acoustic properties in the matching layer according to the description of the ultrasonic transducer 100 above. In some embodiments, the target acoustic impedance may be an acoustic impedance desired to be achieved by the first and second components being produced. In some embodiments, the target acoustic impedance may be designed according to the acoustic impedance of the piezoelectric layer and/or the object to be measured, so that the piezoelectric layer may be acoustically matched with the object to be measured through the matching layer. Further, in some embodiments, the first component and the second component may also have the same target acoustic impedance, so that the different components can be acoustically matched, and the energy consumed when the ultrasonic wave passes through the matching layer is reduced, thereby improving the transmission effect of the matching layer on the ultrasonic wave.

In some embodiments, the target sound velocity gradient profile may be a sound velocity gradient profile that is desired to be achieved by the first and second components being prepared. In some embodiments, the target sound velocity gradient profile can be designed according to the thickness gradient profile of the piezoelectric layer, so that ultrasonic waves of different frequencies have the same wavelength in passing through the matching layer, thereby improving the transmissivity of the matching layer to the ultrasonic waves and increasing the bandwidth of the ultrasonic transducer. In some embodiments, the target sound speed gradient profile may include desired sound speeds to be achieved by the first component and the second component, and locations where the first component and the second component are desired to be set (i.e., preset locations described below).

In some embodiments, the speed of sound of the first and second components may be inversely proportional to the thickness of the piezoelectric layer. For example, when the thickness distribution of the piezoelectric layer is monotonically increasing from the first side to the second side of the piezoelectric layer, the sound velocity distribution of the matching layer may also be monotonically decreasing from the first side of the matching layer (i.e., the location where the first component is located) to the second side (i.e., the location where the second component is located). That is, the sound velocity of the first component can be designed to be greater than the sound velocity of the second component.

In some embodiments, the flow 400 may further include configuring the first component and the second component according to a target density that the matching layer needs to achieve. The target density may be a desired density of the first component and the second component. Since the target acoustic impedance is affected by the speed of sound and the density, in some embodiments, the target densities of the first and second components may be designed according to the target speed of sound gradient distribution and the target acoustic impedance such that the first and second components may also have the same target acoustic impedance.

In some embodiments, configuring the first component and the second component may comprise: the species, proportion, size and structure of the substances in the first component and the second component are configured. For example, the first component and the second component may each be configured to include: 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent and 2g of silane coupling agent KH560 as substrates of the first component and the second component. And then according to the target sound velocity gradient distribution and the target acoustic impedance, selecting one or more of the following materials to introduce the first component and the second component: a first sound velocity range material (e.g., rubber) in an amount of less than or equal to 60g, a second sound velocity range material (e.g., metal oxide, inorganic non-metallic compound of solid structure) in an amount of less than or equal to 130g, a first density range material (e.g., metal) in an amount of less than or equal to 500g, a second density range material (e.g., inorganic non-metallic compound of hollow structure, plastic expanded microspheres) in an amount of less than or equal to 20g to adjust the sound velocities and acoustic impedances of the first and second components so that the matching layer can achieve a target sound velocity distribution and a target acoustic impedance.

It should be noted that, the first component and the second component are only used as examples, and are not limited to the order of the components in the matching layer, and only indicate that different components exist in the matching layer, and the matching layer may also have more other components, such as a third component, a fourth component, and the like, which is not specifically limited in this embodiment.

Step 420, respectively configuring the first component and the second component at corresponding preset positions.

In some embodiments, the preset position may be a position where the first component and the second component are expected to be set, and may be configured according to a target sound velocity gradient profile. In some embodiments, the preset position can be set according to a thickness distribution of the piezoelectric layer. For example, if the first sound velocity of the first component is lower than the second sound velocity of the second component, the first component may be disposed at a position corresponding to the piezoelectric layer having a larger thickness, and the second component may be disposed at a position corresponding to the piezoelectric layer having a smaller thickness.

In some embodiments, the first component and the second component may be disposed at respective predetermined locations by pouring, filling, injecting, or the like. For example, the configured first component and the second component may be encapsulated into the mold in batches, so that the first component and the second component are arranged at preset positions, and the sound velocity gradient distribution of the matching layer can be achieved.

And 430, curing at a preset temperature for a preset time to obtain a matching layer.

In some embodiments, the preset temperature may be a temperature required for curing the components, and the preset temperature may be set according to the species, the proportion, and the size of the first component and the second component. For example, if the epoxy resin is selected as the substrate in the first component and the second component, the curing may be performed at a predetermined temperature of 25 ℃ depending on the amount of the epoxy resin. In some embodiments, the preset time period may also be set according to the species, proportion and size of the substances configured in the first component and the second component.

In some embodiments, the predetermined temperature may range from 20 ℃ to 100 ℃ and the predetermined time period may range from 2h to 48h. In some embodiments, the value of the preset length of time may be inversely proportional to the value of the preset temperature to ensure that the first component and the second component are sufficiently cured. That is, the lower the preset temperature is set, the longer the preset time period needs to be set; conversely, the higher the preset temperature is set, the shorter the preset time period needs to be set. For example, if the epoxy resin is selected as the substrate in the first component and the second component, 100g of the epoxy resin may be cured at a preset temperature of 25 ℃ for a preset time period of 24 hours to prepare the matching layer. 100g of epoxy resin can also be cured at a preset temperature of 60 ℃ for a preset time of 4 hours to prepare the matching layer. 100g of the epoxy resin can also be cured at a preset temperature of 20 ℃ for a preset time of 48 hours to prepare the matching layer.

In some embodiments, the cured matching layer can be attached to the piezoelectric layer by bonding, welding, stapling, or the like. In some embodiments, the matching layer can also be formed directly on the piezoelectric layer, so that the cured matching layer can be disposed on the upper surface of the piezoelectric layer, thereby implementing the function of transmitting ultrasonic waves in the ultrasonic transducer. In some embodiments, after step 430, the matching layer may be ground by a grinder to adjust the thickness of the matching layer quickly and efficiently.

In some embodiments of the present application, the matching layer obtained by curing the first component and the second component may realize sound velocity gradient distribution, so that the wavelengths of the ultrasonic waves of different frequencies in the matching layer are the same, thereby improving the transmittance of the matching layer to the ultrasonic waves and increasing the bandwidth of the ultrasonic transducer. And the matching layer prepared by the curing method can simplify the process flow for manufacturing the ultrasonic transducer and save the cost.

Table 1 is a table of formulations and acoustic properties for a number of exemplary components. Specific embodiments of matching layer compositions are described in detail below with reference to table 1 illustrating the preparation of various exemplary compositions.

TABLE 1 formulation of the Components and corresponding relationship Table of Acoustic Properties

Component A:

100g of epoxy resin and 30g of epoxy resin curing agent can be added into a flask, stirred until the mixture is uniformly mixed (e.g., stirred for 5min, 10min, 15min, etc.), 1g of defoaming agent (not shown in Table 1) is added, the mixture is stirred for a preset stirring time (e.g., 3min, 4min, 5min, etc.), then the epoxy resin is poured into a mold, and the mixture is cured at room temperature for 24h to obtain an epoxy resin cured product, namely, the component A. The component A is subjected to acoustic performance test to obtain the component A with the sound velocity of 2730m/s, the acoustic impedance of 3.14MRayl and the density of 1.15g/cm ³ 。

And (B) component:

100g of epoxy resin and 30g of epoxy resin curing agent can be added to the flask, stirred until the mixture is uniformly mixed (e.g., stirred for 5min, 10min, 15min, etc.), then 1g of defoamer and 2g of silane coupling agent KH560 (not shown in Table 1) can be added, and stirred for a preset stirring period (e.g., 3min, 4min, 5min, etc.). Adding 30g liquid nitrile rubber into the flask, stirring to mix well (such as stirring for 5min, 10min, 15min, etc.), pouring the blended resin into a mold, and curing at room temperature for 24h to obtain the final productAnd obtaining a nitrile rubber modified epoxy resin condensate, namely the component B. The component B is subjected to an acoustic performance test to obtain that the sound velocity of the component B is 2130m/s, the acoustic impedance is 2.63MRayl, and the density is 1.13g/cm ³ 。

And (3) component C:

100g of epoxy resin and 30g of epoxy resin curing agent are added into a flask, and after stirring until uniform mixing (e.g., stirring for 5min, 10min, 15min, etc.), 1g of antifoaming agent and 2g of silane coupling agent KH560 are added, and stirring is carried out for a preset stirring period (e.g., 3min, 4min, 5min, etc.). And adding 15g of silicone rubber A and 15g of silicone rubber B into the flask, stirring until the mixture is uniformly mixed (such as stirring for 5min, 10min, 15min and the like), pouring the blended resin into a mold, and curing at room temperature for 24h to obtain a silicone rubber modified epoxy resin cured product, namely the component C. The component C was subjected to an acoustic performance test to obtain a component C having a sound velocity of 1917m/s, an acoustic impedance of 2.07MRayl and a density of 1.08g/cm ³ 。

As can be seen from the above-mentioned component A-component C, the sound velocities of component B and component C are both less than the sound velocity of component A, and the acoustic impedances of component B and component C are less than the acoustic impedance of component A. That is, by adding rubber to the epoxy resin, the sound velocity of the epoxy resin can be lowered because the rubber component itself has a characteristic of low sound velocity. Compared to epoxy resins (i.e., component A), modified epoxy resins having reduced sound velocity (i.e., component B-component C) can be obtained by incorporating rubber, but with a concomitant reduction in acoustic impedance.

And (3) component D:

100g of epoxy resin and 30g of epoxy resin curing agent are added into a flask, stirred until the mixture is uniformly mixed (for example, stirred for 5min, 10min, 15min and the like), 1g of antifoaming agent and 2g of silane coupling agent KH560 are added, and the mixture is stirred for a preset stirring time (for example, 3 min). And adding 30g of silicone rubber A and 30g of silicone rubber B into the flask, stirring until the mixture is uniformly mixed (such as stirring for 5min, 10min, 15min and the like), pouring the blended resin into a mold, and curing at room temperature for 24h to obtain a silicone rubber modified epoxy resin cured product, namely the component D. Performing acoustic performance test on the component D to obtain the component D with sound velocity of 1503m/s, acoustic impedance of 1.58MRayl and density of 1.05g/cm ³ 。

As can be seen from the above-mentioned component A and component C-component D, the sound velocity and acoustic impedance of component D are both smaller than those of component C. That is, the sound velocity and acoustic impedance of the modified epoxy resin cured product can be further reduced as the amount of the rubber component added is increased as compared with the epoxy resin (i.e., component a).

And (4) component E:

100g of epoxy resin and 30g of epoxy resin curing agent can be added into a flask, and after stirring until uniform mixing (e.g., stirring for 5min, 10min, 15min, etc.), 1g of defoamer and 2g of silane coupling agent KH560 can be added, and stirring is carried out for a preset stirring period (e.g., 3min, 4min, 5min, etc.). And adding 150g of tungsten powder with the particle size of 3 mu m into the flask twice, adding 30g of silicon rubber A and 30g of silicon rubber B into the flask after 10min of addition is finished, stirring until the mixture is uniformly mixed (such as stirring for 5min, 10min, 15min and the like), pouring the blended resin into a mold, and curing at room temperature for 24h to obtain a modified epoxy resin cured substance, namely a component E. The component E is subjected to an acoustic performance test to obtain that the sound velocity of the component E is 1638m/s, the acoustic impedance is 3.14MRayl, and the density is 1.92g/cm ³ 。

As can be seen from the component A and the component D-the component E, the sound velocity of the component D-the component E is smaller than that of the component A, the density of the component D is smaller than that of the component E, and the component A and the component E have the same acoustic impedance. That is, the addition of rubber to the epoxy resin (i.e., component A) can reduce the sound velocity, but the acoustic impedance of the modified epoxy resin cured product (i.e., component D) is reduced. On the basis of the modified epoxy resin condensate (namely, the component D), tungsten powder with high density can be introduced to adjust the properties of the components, and the modified epoxy resin with improved density (namely, the component E) can be obtained, so that the acoustic impedance of the modified epoxy resin (namely, the component E) is improved. Whereas the acoustic impedance of the densified modified epoxy resin (i.e., component E) is consistent with that of the epoxy resin (i.e., component a) compared to the epoxy resin (i.e., component a), the acoustic velocity of the modified epoxy resin (i.e., component E) is lower.

And (3) component F:

100g of epoxy resin and 30g of epoxy resin curing agent are added into a flask, stirred until the mixture is uniformly mixed (for example, stirred for 5min, 10min, 15min and the like), 1g of antifoaming agent and 2g of silane coupling agent KH560 are added, stirred for a preset stirring time (for example,3min, 4min, 5min, etc.). And adding 118g of copper powder with the particle size of 20 mu m into the flask twice, adding 30g of silicone rubber A and 30g of silicone rubber B into the beaker after the addition is finished for 10min, stirring until the mixture is uniformly mixed (for example, stirring for 5min, 10min, 15min and the like), pouring the blended resin into a mold, and curing at room temperature for 24h to obtain a modified epoxy resin cured product, namely a component F. The component F is subjected to acoustic performance test to obtain the component F with the sound velocity of 1882m/s, the acoustic impedance of 3.14MRayl and the density of 1.67g/cm ³ 。

As can be seen from the above-mentioned component D-component F, the acoustic impedance of the component E-component F is greater than that of the component D, and the sound velocity of the component F is greater than that of the component D-component E. That is, both the tungsten powder and the copper powder can improve the acoustic impedance of the modified epoxy resin (i.e., component D), but since the density of the copper powder is low and the volume fraction of the added copper powder is large, the sound velocity can be improved higher by adding the copper powder than by adding the tungsten powder.

A component G:

100g of epoxy resin and 30g of epoxy resin curing agent are added into a flask, and after stirring until uniform mixing (e.g., stirring for 5min, 10min, 15min, etc.), 1g of defoamer and 2g of KH560 are added, and stirring is carried out for a preset stirring period (e.g., 3min, 4min, 5min, etc.). Adding 13G of hollow ceramic microspheres with the particle size of 50 mu m into the flask twice, pouring the modified epoxy resin into a mold after the addition is finished for 10min and the uniform mixing is carried out, and curing the mixture at room temperature for 24h to obtain a modified epoxy resin cured substance, namely a component G. The component G was subjected to an acoustic performance test to obtain a component G having an acoustic velocity of 2960m/s, an acoustic impedance of 3.14MRayl and a density of 1.06G/cm ³ 。

As can be seen from component A-component G, the sound velocity of component G is greater than that of component A, the density of component G is less than that of component A, and the acoustic impedance of component G is the same as that of component A. That is, the effect of increasing the sound velocity and making the impedance constant can be achieved by adding the hollow ceramic micro beads to the epoxy resin (i.e., component a). The addition of the hollow ceramic microspheres can improve the sound velocity on one hand and reduce the density on the other hand, thereby realizing the effects of sound velocity increase and sound impedance invariance.

A component H:

to flaskAdding 100g of epoxy resin and 30g of epoxy resin curing agent, stirring until the mixture is uniformly mixed (such as stirring for 5min, 10min, 15min and the like), adding 1g of defoaming agent and 2g of silane coupling agent KH560, and stirring for a preset stirring time (such as 3min, 4min, 5min and the like). And adding 40g of aluminum oxide microspheres with the particle size of 50 mu m into the flask twice, pouring the modified epoxy resin into a mold after the aluminum oxide microspheres are added for 10min and uniformly mixed, and curing at room temperature for 24H to obtain a modified epoxy resin cured substance, namely a component H. The component H was subjected to an acoustic property test to obtain a component H having a sound velocity of 3112m/s, an acoustic impedance of 5.69MRayl and a density of 1.83g/cm ³ 。

A component I:

100g of epoxy resin and 30g of epoxy resin curing agent are added into a flask, and after stirring until uniform mixing (e.g., stirring for 5min, 10min, 15min, etc.), 1g of defoamer and 2g of silane coupling agent KH560 are added, and stirring is carried out for a preset stirring period (e.g., 3min, 4min, 5min, etc.). And adding 40g of aluminum oxide microspheres with the particle size of 150 mu m into the flask twice, pouring the modified epoxy resin into a mold after the aluminum oxide microspheres are added for 10min and uniformly mixed, and curing at room temperature for 24h to obtain a modified epoxy resin cured substance, namely the component I. The component I is subjected to acoustic performance test to obtain the component I with the sound velocity of 3339m/s, the acoustic impedance of 6.18MRayl and the density of 1.85g/cm ³ 。

And (4) component J:

100g of epoxy resin and 30g of epoxy resin curing agent are added into a flask, and after stirring until uniform mixing, 1g of defoamer and 2g of silane coupling agent KH560 are added, and stirring is carried out for a preset stirring time (e.g., 3min, 4min, 5min, etc.). The flask is divided twice again, and 40g of alumina microspheres and the density of 0.15g/cm are added in total ³ After the 14g of hollow glass microspheres are added for 10min and uniformly mixed, the modified epoxy resin is poured into a mould and cured for 24h at room temperature to obtain a modified epoxy resin cured product, namely the component J. The component J is subjected to an acoustic performance test to obtain that the sound velocity of the component J is 3143m/s, the acoustic impedance is 3.14MRayl, and the density is 1.00g/cm ³ 。

It can be seen from the component H-the component J that the increased sound velocity is higher and higher with the increase of the particle size of the microspheres, and then by adding the low-density hollow glass microspheres, compared with the epoxy resin (i.e., the component a), the modified epoxy resin (i.e., the component J) having the impedance of 3.14MRayl (the same as the acoustic impedance of the component a) and the high sound velocity can be obtained.

Component K-component L:

the component K comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent, 2g of silane coupling agent KH560 and 65g of aluminum oxide microspheres with the particle size of 5-100 μm. The component K is subjected to acoustic performance test to obtain the component K with sound velocity of 3055m/s, acoustic impedance of 4.67MRayl and density of 1.53g/cm ³ 。

The component L comprises: 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent, 2g of silane coupling agent KH560 and 30g of aluminum oxide microspheres with the particle size of 5-100 mu m. The component L is subjected to acoustic performance test to obtain the component L with the sound velocity of 2874m/s, the acoustic impedance of 3.82MRayl and the density of 1.33g/cm ³ . The preparation of component K and component L is similar to that of component H-component I, and will not be described in detail here.

As can be seen from the components H-component I and K-component L, as the content of the metal oxide in the components increases, the sound velocity of the components also increases, and the content of the metal oxide in the first component and the second component can be adjusted to enable the first component and the second component to have different sound velocities.

Several exemplary formulations of the components and their acoustical properties are provided below, and the preparation is similar to the above-described preparation of component A-component J and will not be described further herein.

And (3) component M:

the component M comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of antifoaming agent, 2g of silane coupling agent KH560 and 500g of tungsten powder. Performing acoustic performance test on the component M to obtain the component M with sound velocity of 1719M/s, acoustic impedance of 7.64MRayl and density of 4.45g/cm ³ . According to the component A and the component M, the tungsten powder is independently added into the epoxy resin, so that the acoustic impedance and the density of the epoxy resin can be greatly improved, and the sound velocity of the epoxy resin is reduced.

And (4) a component N:

the component N comprises 100g of epoxy resin, 30g of epoxy resin curing agent and 1g of antifoaming agent, 2g of silane coupling agent KH560, 20g of content and 0.15g/cm of density ³ The hollow glass microspheres of (1). The component N is subjected to acoustic performance test to obtain the component N with acoustic velocity of 2526m/s, acoustic impedance of 1.57MRayl and density of 0.62g/cm ³ . According to the component A and the component N, the hollow glass beads are independently added into the epoxy resin, so that the density of the epoxy resin can be greatly reduced, and the sound velocity and the acoustic impedance of the epoxy resin are reduced.

A component O:

the component O comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent, 2g of silane coupling agent KH560, 30g of butyronitrile and 130g of aluminum oxide microspheres. The component O is subjected to an acoustic performance test to obtain the component O with the sound velocity of 2791m/s, the acoustic impedance of 4.97MRayl and the density of 1.78g/cm ³ 。

A component P:

the component P comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent, 2g of silane coupling agent KH560, 30g of silicone rubber A, 30g of silicone rubber B and hollow ceramic microspheres with the content of 13g and the particle size of 50 mu m. The component P is subjected to an acoustic performance test to obtain that the sound velocity of the component P is 1816m/s, the acoustic impedance is 1.80MRayl, and the density is 0.99g/cm ³ 。

A component Q:

the component Q comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent, 2g of silane coupling agent KH560, 30g of silicone rubber A, 30g of silicone rubber B, 50g of tungsten and 20g of aluminum oxide microspheres. The component Q was subjected to an acoustic performance test to obtain a component Q having an acoustic velocity of 2259m/s, an acoustic impedance of 3.14MRayl and a density of 1.39g/cm ³ 。

A component R:

the component R comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of antifoaming agent, 2g of silane coupling agent KH560, 30g of silicone rubber A, 30g of silicone rubber B, 50g of tungsten and the components with the content of 10g and the density of 0.15g/cm ³ The hollow glass microspheres of (1). The component R is subjected to acoustic performance test to obtain the component R with the sound velocity of 2152m/s, the acoustic impedance of 2.15MRayl and the density of 1.00g/cm ³ 。

A component S:

the component S comprises 100g of epoxy resin and 30g of epoxy resin for curing1g of defoaming agent, 2g of silane coupling agent KH560, 30g of silicone rubber A, 30g of silicone rubber B, 65g of aluminum oxide microspheres, 10g of silicon rubber B, and 0.15g/cm of silicon rubber B ³ The hollow glass microspheres of (1). Performing acoustic performance test on the component S to obtain the component S with the sound velocity of 2427m/S, the acoustic impedance of 2.45MRayl and the density of 1.01g/cm ³ 。

A component T:

the component T comprises 100g of epoxy resin, 30g of epoxy resin curing agent, 1g of defoaming agent, 2g of silane coupling agent KH560, 30g of silicon rubber A, 30g of silicon rubber B, 50g of tungsten powder, 65g of aluminum oxide microspheres and the components with the content of 10g and the density of 0.15g/cm ³ The hollow glass microspheres of (1). The component T is subjected to acoustic performance test to obtain the component T with acoustic velocity of 2553m/s, acoustic impedance of 3.04MRayl and density of 1.19g/cm ³ 。

In some embodiments, one or more combinations of components B-T may be selected as the first component and the second component so that the first component and the second component have different sound velocities to achieve a target sound velocity distribution of the matching layer. Further, in some embodiments, one or more combinations of components E, F, G, J, and Q may be selected as the first component and the second component such that the first component and the second component have different acoustic speeds and the same acoustic impedance to achieve a target acoustic speed distribution and a target acoustic impedance of the matching layer.

It should be noted that the acoustic performance parameters of the components in table 1 are only illustrative, and the acoustic performance parameters of the components in table 1 are not specifically limited in this application.

The beneficial effects that may be brought by the embodiments of the present description include, but are not limited to: by filling components with different sound velocities at different positions, the sound velocity of the formed matching layer is distributed in a gradient manner in at least one direction (such as the elevation angle direction of the matching layer), so that the transmissivity of the matching layer to sound waves with different frequencies is improved, and the bandwidth of the ultrasonic transducer is increased.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be considered as illustrative only and not limiting, of the present invention. Various modifications, improvements and adaptations to the present description may occur to those skilled in the art, though not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present specification and thus fall within the spirit and scope of the exemplary embodiments of the present specification.

Also, the description uses specific words to describe embodiments of the specification. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the specification is included. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, certain features, structures, or characteristics may be combined as suitable in one or more embodiments of the specification.

Additionally, the order in which elements and sequences are described in this specification, the use of numerical letters, or other designations are not intended to limit the order of the processes and methods described in this specification, unless explicitly stated in the claims. While certain presently contemplated useful embodiments of the invention have been discussed in the foregoing disclosure by way of various examples, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein described. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the foregoing description of embodiments of the present specification, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to imply that more features than are expressly recited in a claim. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

For each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited in this specification, the entire contents of each are hereby incorporated by reference into this specification. Except where the application history document is inconsistent or contrary to the present specification, and except where the application history document is inconsistent or contrary to the present specification, the application history document is not inconsistent or contrary to the present specification, but is to be read in the broadest scope of the present claims (either currently or hereafter added to the present specification). It is to be understood that the descriptions, definitions and/or uses of terms in the accompanying materials of the present specification shall control if they are inconsistent or inconsistent with the statements and/or uses of the present specification.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments of the present disclosure. Other variations are also possible within the scope of the present description. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present specification can be seen as consistent with the teachings of the present specification. Accordingly, the embodiments of the present description are not limited to only those explicitly described and depicted herein.

Claims

1. A matching layer for an ultrasound transducer comprising at least a first component and a second component, wherein:

the first component has a first speed of sound;

the second component has a second acoustic velocity;

the first component and the second component are respectively filled in different positions of the same plane of the ultrasonic transducer, so that the sound velocity of the matching layer is in gradient distribution in at least one direction.

2. The matching layer of claim 1, the first and second components having the same acoustic impedance and/or the same thickness.

3. The matching layer of claim 1, wherein:

the first component and the second component have at least one different kind of material; or

The first component and the second component have the same kind of material, at least one of which is different in proportion, size, and/or structure in the first component and the second component.

4. The matching layer of claim 1, wherein:

the material of the first component and/or the second component comprises an epoxy resin;

the materials of the first and/or second components further include at least one of a first range of acoustic velocities of materials, a second range of acoustic velocities of materials, a first range of densities of materials, and a second range of densities of materials, the first range of acoustic velocities being less than the second range of acoustic velocities, the first range of densities being greater than the second range of densities.

5. The matching layer of claim 4, wherein:

the first sound velocity range is 800m/s-2000m/s, the second sound velocity range is 2800m/s-11000m/s, andthe first density range is 3g/cm ³ -20 g/cm ³ And the second density range is 0.1g/cm ³ -0.8g/cm ³ 。

6. The matching layer of claim 4, wherein:

the content of the epoxy resin is 100g;

the content of material of the first sound speed range is less than or equal to 60g, or the content of material of the second sound speed range is less than or equal to 130g, or the content of material of the first density range is less than or equal to 500g, or the content of material of the second density range is less than or equal to 20g.

7. The matching layer of claim 4, wherein:

the material of the first sound velocity range comprises rubber, the material of the second sound velocity range comprises metal oxide and/or inorganic non-metallic compound with solid structure, the material of the first density range comprises metal, and the material of the second density range comprises inorganic non-metallic compound with hollow structure and/or plastic expansion microsphere.

8. The matching layer of claim 7, wherein:

the material of the first component includes the epoxy resin, the rubber, and the metal, the material of the second component includes the epoxy resin, the metal oxide, and the inorganic non-metallic compound of the hollow structure, a first acoustic velocity of the first component is smaller than a second acoustic velocity of the second component, and the first component and the second component have the same acoustic impedance.

9. The matching layer of claim 7, wherein:

the epoxy resin comprises at least one of bisphenol A type epoxy resin and bisphenol F type epoxy resin;

the rubber comprises at least one of thermoplastic SBS elastomer, nitrile rubber, butyl rubber, styrene butadiene rubber, ethylene propylene diene monomer rubber, silicon rubber and fluororubber;

the metal comprises at least one of tungsten, copper, iron and lead;

the metal oxide comprises at least one of tungsten trioxide, ferric oxide, aluminum oxide, zinc oxide and magnesium oxide;

the inorganic nonmetallic compound comprises at least one of glass, ceramic and boron carbide.

10. The matching layer of claim 1, the first or second acoustic velocity ranging from 1400 to 3500m/s.

11. An ultrasonic transducer comprising: a piezoelectric layer and a matching layer according to any of claims 1-10 above,

the matching layer is arranged between the piezoelectric layer and an object to be tested, the piezoelectric layer is matched with the object to be tested in an acoustic mode through the matching layer, and the piezoelectric layer is used for converting ultrasonic waves and electric energy.

12. The ultrasonic transducer of claim 11, wherein:

the thickness of the piezoelectric layer at least comprises a first thickness and a second thickness, and the first thickness and the second thickness are different;

the gradient distribution of the acoustic velocity of the matching layer corresponds to the thickness distribution of the piezoelectric layer.

13. The ultrasonic transducer of claim 12, wherein:

the gradient distribution of the acoustic velocity of the matching layer has an inverse relationship with the thickness distribution of the piezoelectric layer.

14. The ultrasonic transducer of claim 12, wherein:

the first acoustic velocity of the first component of the matching layer corresponds to the first thickness of the piezoelectric layer, and the second acoustic velocity of the second component of the matching layer corresponds to the second thickness of the piezoelectric layer;

the first thickness is greater than the second thickness, and the first speed of sound is less than the second speed of sound.

15. A method for preparing a matching layer of any of claims 1-10, comprising:

configuring the first component and the second component according to target acoustic impedance and target sound velocity gradient distribution which needs to be achieved by the matching layer;

respectively arranging the first component and the second component at corresponding preset positions;

and curing at a preset temperature for a preset time to obtain the matching layer.

16. The method according to claim 15, wherein the preset temperature is in the range of 20 ℃ to 100 ℃ and the preset time period is in the range of 2h to 48h.