Vibration unit, piezoelectric structure, ultrasonic transducer and manufacturing method

Abstract

This invention provides a vibration unit, a piezoelectric structure, an ultrasonic transducer, and a manufacturing method. The vibration unit includes a backing layer, a piezoelectric layer, and at least two matching layers with different acoustic impedances. The piezoelectric layer is disposed on the backing layer. At least two matching layers are disposed on the piezoelectric layer, and at least one set of adjacent matching layers have different projected dimensions in the vertical direction or different vertical centerlines. In this invention, when at least two vibration units are arranged side by side, the gaps formed on each layer are discontinuous, thereby forming various types of gap structures, adjusting the acoustic impedance of the matching layers, and thus expanding the applicable range of the matching layers.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic transducer technology, specifically relating to a vibration unit, a piezoelectric structure, an ultrasonic transducer, and a manufacturing method. Background Technology

[0002] The ultrasonic transducer is the core component of an ultrasonic system. It converts the electrical properties of the entire system into acoustic properties through the inverse piezoelectric effect, emitting acoustic signals to the object under test. It then converts the received reflected acoustic signals back into electrical signals through the piezoelectric effect. The quality of an ultrasonic system largely depends on the signal conversion performance of the ultrasonic transducer. Performance metrics include center frequency, sensitivity, bandwidth, and pulse length. To achieve optimal performance, the vibrating unit of an ultrasonic transducer typically consists of a backing layer for sound absorption, a piezoelectric layer for electroacoustic / acoustoelectric conversion, several matching layers to match the acoustic impedance of the object under test, and a sound-transmitting layer for focusing and peripheral protection. A typical ultrasonic transducer consists of dozens to thousands of independent vibrating units (see reference). Figure 1 These vibration units, arranged in different patterns, enable imaging of two-dimensional cross-sections and even three-dimensional space of the object under test. In addition to the material composition mentioned above, the aspect ratio, spacing, and sealant of these vibration units also affect the vibration performance.

[0003] Currently, the main mode of clinical ultrasound imaging is harmonic imaging. This involves the ultrasound system exciting a transducer to emit a low-frequency fundamental wave. After propagating through human tissue, due to nonlinear effects, higher harmonics (multiple harmonics) are generated, which are then received by the ultrasound transducer and processed by the ultrasound system to form an ultrasound image with both penetration depth and spatial resolution. As can be seen from the principle of harmonic imaging, to achieve good harmonic imaging results, the bandwidth of the ultrasound transducer must be able to cover the frequency range of the fundamental wave and higher harmonics. Therefore, one of the key points and challenges in ultrasound transducer design is how to achieve echo spectrum performance with a high bandwidth. Summary of the Invention

[0004] This invention provides a vibration unit, a piezoelectric structure, an ultrasonic transducer, and a manufacturing method to solve the problem of small bandwidth in existing ultrasonic transducers.

[0005] A vibration unit includes a backing layer, a piezoelectric layer, and at least two matching layers with different acoustic impedances, wherein the piezoelectric layer is disposed on the backing layer;

[0006] At least two matching layers are disposed on the piezoelectric layer, and at least one pair of adjacent matching layers have different projection dimensions or different vertical center lines in the vertical direction.

[0007] Preferably, the acoustic impedance of at least two of the matching layers gradually decreases, and the acoustic impedance of the matching layer closer to the piezoelectric layer is greater than that of the matching layer farther away from the piezoelectric layer.

[0008] Preferably, the width of the vibration unit is no greater than twice the wavelength corresponding to the operating frequency;

[0009] The width of the vibration unit is the width of the projected area of ​​the piezoelectric layer in the vertical direction.

[0010] Preferably, the aspect ratio of the piezoelectric layer is not greater than 2.

[0011] Preferably, the vibration unit further includes a sound-permeable layer, which is disposed on the outermost matching layer.

[0012] A piezoelectric structure comprising the aforementioned vibration unit;

[0013] At least two vibration units are arranged side by side at intervals in a horizontal direction, and each vibration unit includes a backing layer, a piezoelectric layer and at least two matching layers disposed on the piezoelectric layer;

[0014] At least one set of adjacent matching layers have different projection dimensions or different vertical center lines in the vertical direction, so that the piezoelectric structure forms at least two dividing gaps in the vertical direction, including at least one set of adjacent dividing gaps with different widths, or at least one set of adjacent dividing gaps whose vertical center lines are not on the same straight line.

[0015] Preferably, the vertical center lines of two adjacent dividing gaps with different widths are either on the same straight line or not on the same straight line.

[0016] Preferably, the widths of two adjacent dividing gaps whose vertical center lines are not on the same straight line are the same or different.

[0017] Preferably, each of the vibration units includes at least three matching layers, and there is at least one set of adjacent matching layers with the same projection size in the vertical direction, so that in the at least two dividing gaps formed by the piezoelectric structure in the vertical direction, there is at least one set of adjacent dividing gaps with the same width, and the vertical center lines of the adjacent dividing gaps with the same width are either on the same straight line or not on the same straight line.

[0018] Preferably, the matching layer includes a first matching layer and a second matching layer;

[0019] The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers;

[0020] The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers;

[0021] The width of the second dividing gap is not equal to the width of the first dividing gap.

[0022] Preferably, the matching layer includes a first matching layer and a second matching layer;

[0023] The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers;

[0024] The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers;

[0025] The vertical center line of the first dividing gap and the vertical center line of the second dividing gap are not on the same straight line.

[0026] Preferably, the matching layer includes a first matching layer, a second matching layer, and a third matching layer;

[0027] The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers;

[0028] The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers;

[0029] The third matching layer is disposed on the second matching layer, and a third dividing gap is formed between two adjacent third matching layers;

[0030] The width of the first dividing gap is not equal to the width of the second dividing gap, and / or the width of the second dividing gap is not equal to the width of the third dividing gap.

[0031] Preferably, the matching layer includes a first matching layer, a second matching layer, and a third matching layer;

[0032] The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers;

[0033] The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers;

[0034] The third matching layer is disposed on the second matching layer, and a third dividing gap is formed between two adjacent third matching layers;

[0035] The vertical center line of the first dividing gap is not on the same straight line as the vertical center line of the second dividing gap, and / or the vertical center line of the second dividing gap is not on the same straight line as the vertical center line of the third dividing gap.

[0036] Preferably, the widths of two adjacent first dividing gaps along the horizontal direction are either different or the same.

[0037] Preferably, a filling layer is provided within the dividing gap.

[0038] An ultrasonic transducer includes a base plate and at least two of the aforementioned piezoelectric structures disposed on the base plate, with a gap between adjacent piezoelectric structures.

[0039] A method for manufacturing an ultrasonic transducer includes the following steps:

[0040] A backing layer, a piezoelectric layer, and at least one matching layer are sequentially bonded together to obtain a first element. The first element is then cut to form a dividing gap.

[0041] Repeat the process at least once; adhere a matching layer to the first element after cutting, and cut the matching layer to form another dividing gap;

[0042] In this configuration, at least two dividing gaps are formed in the vertical direction, and there exists at least one set of two adjacent dividing gaps with different widths.

[0043] Preferably, the method for manufacturing the ultrasonic transducer further includes:

[0044] A filler layer is filled into at least two of the said dividing gaps to form a second element;

[0045] An acoustically permeable layer is bonded to the outermost side of the second element.

[0046] Preferably, the bonding pressure between two adjacent matching layers is 0.05MPa~2.0MPa.

[0047] In this embodiment of the invention, the vibration unit includes a backing layer, a piezoelectric layer, and at least two matching layers with different acoustic impedances. The backing layer serves to support, absorb sound (i.e., absorb useless sound waves from the back), dissipate heat, and / or clamp the piezoelectric layer, directly affecting the acoustic performance of the vibration unit. The piezoelectric layer is used to achieve electroacoustic / acoustoelectric conversion, specifically converting electrical energy into ultrasonic waves that are emitted to the test object (e.g., human tissue), and converting the echo signal reflected from the test object to output corresponding electrical energy. The matching layers are disposed on the upper surface of the piezoelectric layer and achieve acoustic impedance matching with the test object (e.g., human tissue). Their main function is to increase sound output or reduce sound attenuation, thereby reducing the leakage of the vibration unit's detection signal and improving the performance of the vibration unit.

[0048] The piezoelectric layer is placed on the backing layer. Since there is often a large difference in acoustic impedance between the piezoelectric layer and the object under test, most of the ultrasonic waves are reflected, resulting in a low transmittance of ultrasonic waves from the vibration unit to human tissue, which affects the efficiency of the vibration unit in receiving ultrasonic waves of different frequencies. By placing at least two matching layers with different acoustic impedances on a piezoelectric layer, the transmittance is affected by the thickness of the matching layers and the wavelength of the ultrasonic wave. This can increase the sound output or decrease the sound attenuation, thereby reducing the leakage of the vibration unit's detection signal, improving the performance of the vibration unit, improving the sound wave propagation efficiency, and thus increasing the bandwidth of the ultrasonic transducer. This allows it to cover the frequency range of the fundamental wave and higher harmonics, achieving better harmonic imaging effects. The number of matching layers can be selected according to actual needs, without requiring special processing of the matching layer thickness based on the structure of the piezoelectric layer, thus reducing the manufacturing difficulty of the ultrasonic transducer. At least one set of two adjacent matching layers have different projection dimensions in the vertical direction. Based on the different sound velocities when each layer of acoustic material is in a large sheet-like form, when the vibration unit has N matching layers, N-1 sets of adjacent matching layers will be formed. Among the N-1 sets of adjacent matching layers, there will be N-1 sets of adjacent matching layers with different projection dimensions in the vertical direction. This arrangement ensures that when at least two vibration units are placed side by side, the gaps formed on each layer are discontinuous, thus forming various types of gap structures, such as V-shaped gap structures. The gap structure can be shaped like a dome, a spindle, or an X. It can also be configured such that the vertical center line of at least one matching layer does not coincide with the vertical center line of the piezoelectric layer. In this way, based on the different sound velocities of the large-size sheet-like acoustic materials in each layer of the vibration unit, the gaps formed on each layer can be discontinuous when at least two vibration units are set up side by side, thus forming a variety of gap structures. This configuration can improve the applicability of the matching layer. Attached Figure Description

[0049] Figure 1 This is a structural diagram of the ultrasonic transducer in an embodiment of the present invention;

[0050] Figure 2This is a first structural diagram of the piezoelectric structure in the embodiments of the present invention;

[0051] Figure 3 This is a second structural diagram of the piezoelectric structure in an embodiment of the present invention;

[0052] Figure 4 This is a third structural diagram of the piezoelectric structure in the embodiments of the present invention;

[0053] Figure 5 This is a fourth structural diagram of the piezoelectric structure in the embodiments of the present invention;

[0054] Figure 6 This is the fifth structural diagram of the piezoelectric structure in the embodiments of the present invention;

[0055] Figure 7 This is a performance diagram of the ultrasonic transducer in an embodiment of the present invention.

[0056] Among them, 1. backing layer; 2. piezoelectric layer; 3. matching layer; 31. first matching layer; 32. second matching layer; 33. third matching layer; 4. dividing gap; 41. first dividing gap; 42. second dividing gap; 43. third dividing gap; 5. base plate. Detailed Implementation

[0057] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0058] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] This invention provides a vibration unit, as shown in the following embodiment. Figure 1-6 The vibration unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 with different acoustic impedances. The piezoelectric layer 2 is disposed on the backing layer 1. At least two matching layers 3 are disposed on the piezoelectric layer 2. At least one pair of adjacent matching layers 3 have different projection dimensions in the vertical direction or different vertical center lines.

[0061] As an example, the vibration unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 with different acoustic impedances. The backing layer 1 serves to support, absorb sound (i.e., absorb unwanted sound waves from the back), dissipate heat, and / or clamp the piezoelectric layer, directly affecting the acoustic performance of the vibration unit. The piezoelectric layer 2 is used to realize electroacoustic / acoustoelectric conversion, specifically converting electrical energy into ultrasonic waves that are emitted to the test object (e.g., human tissue), and converting the echo signal reflected from the test object to output corresponding electrical energy. The matching layers 3 are disposed on the upper surface of the piezoelectric layer 2 and acoustically match the test object (e.g., human tissue). Their main function is to increase sound output or reduce sound attenuation, thereby reducing signal leakage in the vibration unit and improving its performance.

[0062] In this example, the piezoelectric layer 2 is disposed on the backing layer 1. Because the acoustic impedance of the piezoelectric layer 2 and the object under test often differs significantly, most of the ultrasonic waves are reflected, resulting in low transmittance of the ultrasonic waves from the vibrating unit to the human tissue, affecting the efficiency of the vibrating unit in receiving ultrasonic waves of different frequencies. By placing at least two matching layers 3 with different acoustic impedances on the piezoelectric layer 2, the transmittance is affected by the thickness of the matching layer 3 and the wavelength of the ultrasonic waves. This can increase the sound output or reduce the sound attenuation, thereby reducing the leakage of the detection signal from the vibrating unit, improving the performance of the vibrating unit, improving the sound wave propagation efficiency, and thus increasing the bandwidth of the ultrasonic transducer. This allows it to cover the frequency range of the fundamental wave and higher harmonics, achieving better harmonic imaging results. The number of matching layers 3 can be selected according to actual needs, without requiring special processing of the thickness of the matching layers 3 based on the structure of the piezoelectric layer 2, thus reducing the manufacturing difficulty of the ultrasonic transducer. At least one pair of adjacent matching layers 3 have different projected dimensions in the vertical direction, or at least one pair of adjacent matching layers 3 have different vertical centerlines. Based on the different sound velocities of the large-size sheet-like acoustic materials, when the vibrating unit has N matching layers 3 in the vertical direction, N-1 pairs of adjacent matching layers 3 will be formed. Among these N-1 pairs of adjacent matching layers 3, there will be 1 to N-1 pairs of adjacent matching layers 3 with different projected dimensions or different centerlines in the vertical direction. This arrangement ensures that when at least two vibrating units are arranged side-by-side, the dividing gaps 4 formed on each layer are discontinuous, thus forming various types of gap structures, such as V-shaped gap structures. Various gap structures, such as spherical gap structures, spindle-shaped gap structures, and X-shaped gap structures, can be used to create different gap structures by considering the different sound velocities of the large-size sheet-like acoustic materials in each layer of the vibration unit. This allows the gaps 4 formed on each layer to be discontinuous when at least two vibration units are set up side by side, thereby forming a variety of gap structures. This arrangement can improve the applicability of the matching layer 3.

[0063] In one embodiment, reference is made to Figure 1-6 The acoustic impedance of at least two matching layers 3 gradually decreases, and the acoustic impedance of the matching layer 3 closer to the piezoelectric layer 2 is greater than that of the matching layer 3 farther away from the piezoelectric layer 2.

[0064] As an example, the materials of the different matching layers 3 are different. The main difference in materials is reflected in the different acoustic impedances. The acoustic impedance is between that of the piezoelectric layer 2 and the test object. The acoustic impedance of at least two matching layers 3 gradually decreases. The acoustic impedance of the matching layer 3 closer to the piezoelectric layer 2 is greater than that of the matching layer 3 farther away from the piezoelectric layer 2. The closer the matching layer 3 is to the piezoelectric layer 2, the closer its acoustic impedance is to the piezoelectric layer 2. The farther the matching layer 3 is from the piezoelectric layer 2, the closer its acoustic impedance is to the test object. This can effectively achieve a continuous transition of the acoustic impedance of at least two matching layers 3, thereby increasing the bandwidth of the ultrasonic transducer. In this example, each matching layer 3 is cut to have a different width of the dividing gap 4. This can adjust the acoustic impedance of the material of this layer until the dividing gap 4 with the optimal performance is obtained. The thickness of at least two matching layers 3 is generally an odd multiple of 1 / 4 wavelength, with some fluctuations, in order to achieve better sound wave transmission. Since the acoustic impedance of the matching layer 3 material in this example can be adjusted by the split gap 4, a material with relatively large acoustic impedance can be selected. The outermost matching layer 3 has strong surface activity, which makes it easy to bond with the inner matching layer 3 and the sound transmission layer. It has high reliability and moderate hardness, which allows for the cutting of the vibration unit and improves the directivity of the vibration unit.

[0065] In one embodiment, reference is made to Figure 1-6 The width of the vibration unit is no more than twice the wavelength corresponding to the working frequency; the width of the vibration unit is the width of the projection area of ​​the piezoelectric layer 2 in the vertical direction.

[0066] As an example, the width of the vibrating element is the width of the piezoelectric layer 2 within the vibrating element, and is no greater than twice the wavelength corresponding to the operating frequency. For example, the wavelength corresponding to a 15MHz operating frequency is 100µm. In this case, the width of the vibrating element should not exceed 200µm to obtain better acoustic performance, such as improved bandwidth and time-domain waveform. Simultaneously, the directivity of the vibrating element improves, side lobes decrease, avoiding impact on ultrasonic image resolution; and the sensitivity and imaging effect of the ultrasonic transducer are improved.

[0067] In one embodiment, reference is made to Figure 1-6 The aspect ratio of piezoelectric layer 2 is no greater than 2.

[0068] As an example, the aspect ratio of the piezoelectric layer 2 is no greater than 2, that is, the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which can improve the vibration performance and acoustic performance of the vibration unit.

[0069] In one embodiment, reference is made to Figure 1-6 The vibration unit also includes a sound-permeable layer, which is placed on the outermost matching layer 3.

[0070] As an example, the vibration unit also includes a sound-permeable layer, which is placed on the outermost matching layer 3 and serves to focus the ultrasonic signal and protect the ultrasonic transducer.

[0071] This invention provides a piezoelectric structure, referring to... Figure 1-7 The structure includes a vibration unit; at least two vibration units are arranged side by side at intervals along the horizontal direction. Each vibration unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 disposed on the piezoelectric layer 2. At least one set of two adjacent matching layers 3 have different projection dimensions or different vertical center lines in the vertical direction, so that the piezoelectric structure forms at least two dividing gaps 4 in the vertical direction. There is at least one set of two adjacent dividing gaps 4 with different widths, or there is at least one set of two adjacent dividing gaps whose vertical center lines are not on the same straight line.

[0072] As an example, the piezoelectric structure includes vibrating units; at least two vibrating units are arranged side-by-side at intervals along the horizontal direction. Each vibrating unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 disposed on the piezoelectric layer 2. In one specific embodiment, the projected dimensions of at least one set of adjacent matching layers 3 in the vertical direction can be different, so that in the at least two dividing gaps 4 formed by the piezoelectric structure in the vertical direction, there are at least one set of adjacent dividing gaps 4 with different widths. This results in a discontinuous change in the at least two matching layers 3 in the vertical direction, facilitating the adjustment of the acoustic impedance of the matching layers 3 and obtaining a better transmittance, thereby increasing the bandwidth of the ultrasonic transducer. In another specific embodiment, the vertical center lines of at least one set of adjacent matching layers can be different, so that in the at least two dividing gaps formed by the piezoelectric structure in the vertical direction, there are at least one set of adjacent dividing gaps whose vertical center lines are not on the same straight line. This results in a discontinuous change in the at least two matching layers 3 in the vertical direction, facilitating the adjustment of the acoustic impedance of the matching layers 3 and obtaining a better transmittance, thereby increasing the bandwidth of the ultrasonic transducer. In this example, the piezoelectric layer 2 is disposed on the backing layer 1. Since the acoustic impedance of the piezoelectric layer 2 and the test object often differs significantly, most of the ultrasonic waves are reflected, resulting in low transmittance of ultrasonic waves from the vibration unit to human tissue. This affects the efficiency of the vibration unit in receiving ultrasonic waves of different frequencies. By adjusting the acoustic impedance of the matching layer 3 with different segment gaps, a better transmittance can be obtained, thereby increasing the bandwidth of the ultrasonic transducer. By disposing of at least two matching layers 3 with different acoustic impedances on the piezoelectric layer 2, the transmittance is affected by the thickness of the matching layer 3 and the wavelength of the ultrasonic waves. This can increase the sound output or reduce the sound attenuation, thereby reducing the leakage of the detection signal of the vibration unit, improving the performance of the vibration unit, improving the sound wave propagation efficiency, and thus increasing the bandwidth of the ultrasonic transducer. This allows it to cover the frequency range of the fundamental wave and higher harmonics, achieving better harmonic imaging effects.

[0073] In this example, the acoustic impedance of the matching layer 3 is adjusted by a discontinuously varying gap along the vertical direction. This reduces the acoustic impedance requirement of the large matching layer 3, thereby lowering the manufacturing difficulty of the large matching layer 3. The number of matching layers 3 can be selected according to actual needs, and there is no need to specially process the thickness of the matching layer 3 based on the structure of the piezoelectric layer 2, thus reducing the manufacturing difficulty of the ultrasonic transducer. At least one set of two adjacent matching layers 3 have different projection dimensions in the vertical direction, or at least one set of two adjacent matching layers have different vertical center lines, resulting in at least one set of two adjacent gaps having different widths or vertical center lines not being on the same straight line. By adjusting the acoustic impedance of the matching layer 3 through the gap, the sound output can be increased or the sound attenuation can be reduced, thereby reducing the leakage of the vibration unit detection signal, improving the performance of the vibration unit, improving the sound wave propagation efficiency, and thus increasing the bandwidth of the ultrasonic transducer, which can cover the frequency range of the fundamental wave and higher harmonics, achieving better harmonic imaging effect. For example, when the vibration unit has N matching layers 3, N-1 groups of adjacent matching layers 3 will be formed. Among the N-1 groups of adjacent matching layers 3, there will be 1 to N-1 groups of adjacent matching layers 3 with different projection dimensions in the vertical direction. This arrangement ensures that when at least two vibration units are arranged side by side, the dividing gaps 4 formed on each layer are discontinuous, thus forming various forms of gap structures, such as V-shaped gap structures. The gap structure can be shaped like a dome, a spindle, or an X. It can also be configured such that the vertical center line of at least one matching layer 3 does not coincide with the vertical center line of the piezoelectric layer 2. In this way, according to the different sound velocities of the large-size sheet-like acoustic materials in each layer of the vibration unit, the dividing gaps 4 formed on each layer can be discontinuous when at least two vibration units are set up side by side, thus forming a variety of gap structures. This configuration can improve the applicability of the matching layer 3.

[0074] by Taking a gap structure as an example, from the outermost matching layer 3 to the innermost backing layer 1, the width of the gap 4 between each layer of material is not less than the width of the gap 4 between the outermost layer of material. If the piezoelectric layer 2 or matching layer 3 of the vibration unit is composed of several sub-vibration units, then the width of the gap 4 between each layer of the sub-vibration unit is not less than the width of the gap 4 between the outermost layer of material. This cutting method is suitable for the division between vibration units or in the transverse and elevation directions within the vibration unit.

[0075] In this example, by changing the number of matching layers 3, the number of dividing gaps 4, and their width, the piezoelectric structure can take various forms, with the dividing gaps 4 of each layer arranged in a discontinuous variation design; see reference. Figure 7 , Figure 7Yes, Figure A shows the spectral performance of the ultrasonic transducer with the same width of the segmentation gap 4 in each layer in the prior art. The echo spectral bandwidth of the ultrasonic transducer is about 75%, while... Figure 7 Figure B in the diagram shows the spectral performance of the ultrasonic transducer using a discontinuous design in this scheme. The echo bandwidth of the ultrasonic transducer can reach approximately 100%. Figure 7 Figure C in the figure is a comparison of the spectral performance of the prior art and the present solution. As can be seen from the figure, the present solution can significantly improve the harmonic imaging effect.

[0076] In one embodiment, reference is made to Figure 2-4 The vertical center lines of two adjacent dividing gaps 4 with different widths may or may not be on the same straight line.

[0077] As an example, each vibration unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 disposed on the piezoelectric layer 2. At least one set of adjacent matching layers 3 have different projected dimensions in the vertical direction, so that the piezoelectric structure forms at least two dividing gaps 4 in the vertical direction. There are at least one set of adjacent dividing gaps 4 with different widths. When the vertical center lines of the two adjacent dividing gaps 4 with different widths are collinear, the two dividing gaps 4 form a symmetrical gap structure; when the vertical center lines of the two adjacent dividing gaps 4 with different widths are not collinear, the two dividing gaps 4 form an asymmetrical gap structure. The arrangement of the gap structure can be selected according to the actual situation. By adjusting the acoustic impedance of the matching layers 3 through dividing gaps of different widths, better transmittance and bandwidth can be obtained, thereby improving the imaging effect.

[0078] In one embodiment, such as Figure 3 and Figure 4 As shown, the widths of two adjacent dividing gaps whose vertical center lines are not on the same straight line are either the same or different.

[0079] As an example, each vibration unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 disposed on the piezoelectric layer 2. At least one set of adjacent matching layers have different vertical centerlines, so that the piezoelectric structure forms at least two vertically segmented gaps 4. There are at least one set of adjacent segmented gaps whose vertical centerlines are not on the same straight line. In this case, the widths of the adjacent segmented gaps can be the same or different, both forming an asymmetrical gap structure with discontinuous changes along the vertical direction. The arrangement of the gap structure can be selected according to the actual situation. This arrangement, by having the vertical centerlines not on the same straight line, causes discontinuous changes in the segmented gaps, thereby adjusting the acoustic impedance of the matching layer 3, which can obtain better transmittance and bandwidth, thus improving the imaging effect.

[0080] In one embodiment, reference is made to Figure 5 and Figure 6Each vibration unit includes at least three matching layers 3, and there is at least one set of adjacent matching layers 3 with the same projection size in the vertical direction, so that in the at least two dividing gaps 4 formed by the piezoelectric structure in the vertical direction, there is at least one set of adjacent dividing gaps 4 with the same width, and the vertical center lines of the adjacent dividing gaps 4 with the same width are either on the same straight line or not on the same straight line.

[0081] As an example, each vibration unit includes at least three matching layers 3, and there exists at least one pair of adjacent matching layers 3 with the same vertical projection size. This ensures that within the at least two vertically formed segmented gaps 4 created by the piezoelectric structure, there is also at least one pair of adjacent segmented gaps 4 with the same width. When the vertical center lines of the two adjacent segmented gaps 4 with the same width are collinear, the two segmented gaps 4 form a symmetrical gap structure; when the vertical center lines of the two adjacent segmented gaps 4 with the same width are not collinear, the two segmented gaps 4 form an asymmetrical gap structure. The arrangement of the gap structure can be selected according to the actual situation, and the acoustic impedance of the matching layers 3 can be adjusted to obtain better transmittance and bandwidth, thereby improving the imaging effect.

[0082] In one embodiment, reference is made to Figure 2 and Figure 3 The matching layer 3 includes a first matching layer 31 and a second matching layer 32. The first matching layer 31 is disposed on the piezoelectric layer 2, and a first dividing gap 41 is formed between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. The second matching layer 32 is disposed on the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32. The width of the second dividing gap 42 is not equal to the width of the first dividing gap 41.

[0083] As an example, two matching layers 3 are selected, including a first matching layer 31 and a second matching layer 32. First, the first matching layer 31 is bonded to the piezoelectric layer 2, and a first dividing gap 41 is formed between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. Then, the second matching layer 32 is bonded to the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32. The width of the second dividing gap 42 is not equal to the width of the first dividing gap 41, so that the dividing gaps 4 formed on each layer are discontinuous, thereby forming a variety of gap structures. This setting can improve the applicability of the matching layer 3.

[0084] In this embodiment, when the width of the second dividing gap 42 is not equal to the width of the first dividing gap 41, the vertical center line of the width of the first dividing gap 41 and the vertical center line of the second dividing gap 42 are either on the same straight line or not on the same straight line; when the width of the second dividing gap 42 is greater than the width of the first dividing gap 41, the first dividing gap 41 and the second dividing gap 42 form a V-shaped gap structure or a first non-axisymmetric gap structure; when the width of the second dividing gap 42 is less than the width of the first dividing gap 41, the first dividing gap 41 and the second dividing gap 42 form A shaped gap structure or a second non-axisymmetric gap structure.

[0085] As an example, when the vertical center line of the first dividing gap and the vertical center line of the second dividing gap are on the same straight line, if the width of the second dividing gap 42 is greater than the width of the first dividing gap 41, a V-shaped gap structure is formed between the two.

[0086] As an example, when the vertical center line of the first dividing gap and the vertical center line of the second dividing gap are on the same straight line, if the width of the second dividing gap 42 is less than the width of the first dividing gap 41, then a gap is formed between them. Gap structure.

[0087] As an example, when the vertical center line of the first dividing gap and the vertical center line of the second dividing gap are not on the same straight line, if the width of the second dividing gap 42 is greater than the width of the first dividing gap 41, a first non-axisymmetric gap structure is formed between the two.

[0088] As an example, when the vertical center line of the first dividing gap and the vertical center line of the second dividing gap are not on the same straight line, if the width of the second dividing gap 42 is less than the width of the first dividing gap 41, a second non-axisymmetric gap structure is formed between the two.

[0089] In this example, the aforementioned V-shaped gap structure, The piezoelectric gap structure, the first non-axisymmetric gap structure, and the second non-axisymmetric gap structure can all cause at least two matching layers 3 of the piezoelectric structure to have discontinuous changes in the vertical direction, so as to adjust the acoustic impedance of the matching layer 3, thereby obtaining better transmittance and bandwidth, and thus improving the imaging effect.

[0090] As an example, when the vertical center line of the width of the first dividing gap 41 is not on a straight line with the vertical center line of the second dividing gap 42; when the width of the second dividing gap 42 is greater than the width of the first dividing gap 41, the first dividing gap 41 and the second dividing gap 42 form a V-shaped gap structure; when the width of the second dividing gap 42 is less than the width of the first dividing gap 41, the first dividing gap 41 and the second dividing gap 42 form... Gap structure.

[0091] As an example, when the vertical center line of the width of the first dividing gap 41 is not on the same straight line as the vertical center line of the second dividing gap 42; when the width of the second dividing gap 42 is greater than the width of the first dividing gap 41, a first non-axisymmetric gap structure is formed; when the width of the second dividing gap 42 is less than the width of the first dividing gap 41, a second non-axisymmetric gap structure is formed.

[0092] V-shaped gap structure The piezoelectric gap structure, the first non-axisymmetric gap structure, and the second non-axisymmetric gap structure can all cause at least two matching layers 3 of the piezoelectric structure to have discontinuous changes in the vertical direction, so as to adjust the echo spectrum bandwidth of the piezoelectric structure and thus improve the harmonic imaging effect.

[0093] In one embodiment, reference is made to Figure 4 The matching layer 3 includes a first matching layer 31 and a second matching layer 32. The first matching layer 31 is disposed on the piezoelectric layer 2, and a first dividing gap 41 is formed between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. The second matching layer 32 is disposed on the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32. The vertical center line of the width of the first dividing gap 41 and the vertical center line of the second dividing gap 42 are not on the same straight line.

[0094] As an example, two matching layers 3 are selected, including a first matching layer 31 and a second matching layer 32. The first matching layer 31 is first bonded to the piezoelectric layer 2, and a first dividing gap 41 is formed between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. The second matching layer 32 is set on the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32. The vertical center line of the width of the first dividing gap 41 and the vertical center line of the second dividing gap 42 are not on the same straight line. The gap structure formed by the first dividing gap 41 and the second dividing gap 42 is an asymmetrical gap structure, so that the dividing gaps 4 formed on each layer are discontinuous, thereby forming a variety of gap structures. This setting can improve the applicability of the matching layer 3.

[0095] In one embodiment, reference is made to Figure 5 and Figure 6The matching layer 3 includes a first matching layer 31, a second matching layer 32, and a third matching layer 33. The first matching layer 31 is disposed on the piezoelectric layer 2, and a first dividing gap 41 is formed between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. The second matching layer 32 is disposed on the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32. The third matching layer 33 is disposed on the second matching layer 32, and a third dividing gap 43 is formed between two adjacent third matching layers 33. The width of the first dividing gap 41 is not equal to the width of the second dividing gap 42, and / or the width of the second dividing gap 42 is not equal to the width of the third dividing gap 43.

[0096] As an example, three matching layers 3 are selected, including a first matching layer 31, a second matching layer 32, and a third matching layer 33. First, the first matching layer 31 is bonded to the piezoelectric layer 2, forming a first dividing gap 41 between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. Then, the second matching layer 32 is bonded to the first matching layer 31, forming a second dividing gap 42 between two adjacent second matching layers 32. Then, the third matching layer 33 is bonded to the second matching layer 32, forming a third dividing gap 43 between two adjacent third matching layers 33. The width of the first dividing gap 41 is not equal to the width of the second dividing gap 42, and / or the width of the second dividing gap 42 is not equal to the width of the third dividing gap 43, so that the dividing gaps 4 formed on each layer are discontinuous, thereby forming various forms of gap structures. This setting can improve the applicability of the matching layer 3.

[0097] The widths of the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 increase sequentially to form a V-shaped gap structure.

[0098] When the widths of the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 decrease sequentially, in order to form Shaped gap structure;

[0099] When the width of the first dividing gap 41 is less than the width of the second dividing gap 42, and the width of the second dividing gap 42 is greater than the width of the third dividing gap 43, a spindle-shaped gap structure is formed.

[0100] When the width of the first dividing gap 41 is greater than the width of the second dividing gap 42, and the width of the second dividing gap 42 is less than the width of the third dividing gap 43, an X-shaped gap structure is formed.

[0101] When the width of the first dividing gap 41 is less than the width of the second dividing gap 42, and the width of the second dividing gap 42 is equal to the width of the third dividing gap 43, an inverted U-shaped gap structure is formed.

[0102] When the width of the first dividing gap 41 is greater than the width of the second dividing gap 42, and the width of the second dividing gap 42 is equal to the width of the third dividing gap 43, a U-shaped gap structure is formed.

[0103] V-shaped gap structure The piezoelectric structure can be divided into four types: swivel-shaped gap structure, spindle-shaped gap structure, X-shaped gap structure, inverted U-shaped gap structure, and U-shaped gap structure. All of these can cause at least two matching layers 3 of the piezoelectric structure to have discontinuous changes in the vertical direction. Different gap structures are used to adjust the acoustic impedance of the matching layer 3 to obtain a better bandwidth, thereby improving the imaging effect.

[0104] In one embodiment, reference is made to Figure 5 and Figure 6 The width of the first dividing gap 41 is equal to the width of the second dividing gap 42, and the width of the second dividing gap 42 is not equal to the width of the third dividing gap 43; or, the width of the first dividing gap 41 is not equal to the width of the second dividing gap 42, and the width of the second dividing gap 42 is not equal to the width of the third dividing gap 43; or, the width of the first dividing gap 41 is not equal to the width of the second dividing gap 42, and the width of the second dividing gap 42 is equal to the width of the third dividing gap 43.

[0105] As an example, when the width of the first dividing gap 41 is equal to the width of the second dividing gap 42, and the width of the second dividing gap 42 is greater than the width of the third dividing gap 43, the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 form an inverted U-shaped gap structure; when the width of the first dividing gap 41 is equal to the width of the second dividing gap 42, and the width of the second dividing gap 42 is greater than the width of the third dividing gap 43, the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 form a U-shaped gap structure.

[0106] As an example, when the widths of the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 increase sequentially, a V-shaped gap structure is formed; when the widths of the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 decrease sequentially, a V-shaped gap structure is formed. A spindle-shaped gap structure is formed when the width of the first dividing gap 41 is less than the width of the second dividing gap 42, and the width of the second dividing gap 42 is greater than the width of the third dividing gap 43; an X-shaped gap structure is formed when the width of the first dividing gap 41 is greater than the width of the second dividing gap 42, and the width of the second dividing gap 42 is less than the width of the third dividing gap 43.

[0107] As an example, when the width of the first dividing gap 41 is less than the width of the second dividing gap 42, and the width of the second dividing gap 42 is equal to the width of the third dividing gap 43, an inverted U-shaped gap structure is formed; when the width of the first dividing gap 41 is greater than the width of the second dividing gap 42, and the width of the second dividing gap 42 is equal to the width of the third dividing gap 43, a U-shaped gap structure is formed.

[0108] In one embodiment, reference is made to Figure 5 and Figure 6 The matching layer 3 includes a first matching layer 31, a second matching layer 32, and a third matching layer 33. The first matching layer 31 is disposed on the piezoelectric layer 2, and a first dividing gap 41 is formed between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. The second matching layer 32 is disposed on the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32. The third matching layer 33 is disposed on the second matching layer 32, and a third dividing gap 43 is formed between two adjacent third matching layers 33. The vertical center line of the first dividing gap 41 is not on the same straight line as the vertical center line of the second dividing gap 42, and / or the vertical center line of the second dividing gap 42 is not on the same straight line as the vertical center line of the third dividing gap 43.

[0109] As an example, three matching layers 3 are selected, including a first matching layer 31, a second matching layer 32, and a third matching layer 33. First, the first matching layer 31 is bonded to the piezoelectric layer 2, forming a first dividing gap 41 between two adjacent first matching layers 31 in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers 2. Then, the second matching layer 32 is bonded to the first matching layer 31, forming a second dividing gap 42 between two adjacent second matching layers 32. Then, the third matching layer 33 is bonded to the second matching layer 32, forming a third dividing gap 43 between two adjacent third matching layers 33. The vertical center line of the first dividing gap 41 is not on the same straight line as the vertical center line of the second dividing gap 42, and / or the vertical center line of the second dividing gap 42 is not on the same straight line as the vertical center line of the third dividing gap 43, so that the dividing gaps 4 formed on each layer are discontinuous, thereby forming various forms of gap structures. This setting can improve the applicability of the matching layer 3.

[0110] As an example, the vertical center lines of the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 can be combined in the following ways:

[0111] The first type is where the vertical center line of the first dividing gap 41 is not on the same straight line as the vertical center line of the second dividing gap 42, and the vertical center line of the second dividing gap 42 is on the same straight line as the vertical center line of the third dividing gap 43.

[0112] The second type is where the vertical center line of the first dividing gap 41 is not on the same straight line as the vertical center line of the second dividing gap 42, and the vertical center line of the second dividing gap 42 is not on the same straight line as the vertical center line of the third dividing gap 43.

[0113] The third type is where the vertical center line of the first dividing gap 41 and the vertical center line of the second dividing gap 42 are on the same straight line, and the vertical center line of the second dividing gap 42 and the vertical center line of the third dividing gap 43 are not on the same straight line.

[0114] In this example, when the vertical center line of the first dividing gap 41 is not on the same straight line as the vertical center line of the second dividing gap 42, and / or the vertical center line of the second dividing gap 42 is not on the same straight line as the vertical center line of the third dividing gap 43, the widths of the first dividing gap 41, the second dividing gap 42, and the third dividing gap 43 can be the same or different, and can be determined independently according to the actual situation. Since there is at least one set of two adjacent dividing gaps whose vertical center lines are not on the same straight line among the three dividing gaps, at least two matching layers 3 of the piezoelectric structure can have discontinuous changes in the vertical direction. Different gap structures are used to adjust the acoustic impedance of the matching layer 3 to obtain a better bandwidth, thereby improving the imaging effect.

[0115] In one embodiment, reference is made to Figure 4 The widths of two adjacent first dividing gaps 41 along the horizontal direction are either different or the same.

[0116] As an example, two matching layers 3 are selected, including a first matching layer 31 and a second matching layer 32. First, the first matching layer 31 is bonded to the piezoelectric layer 2, and two first dividing gaps 41 are formed between two adjacent first matching layers 31 in the horizontal direction. Each first dividing gap 41 is equal to the piezoelectric dividing gap formed between its corresponding two adjacent piezoelectric layers 2. Then, the second matching layer 32 is bonded to the first matching layer 31, and a second dividing gap 42 is formed between two adjacent second matching layers 32 in the horizontal direction. The widths of the two adjacent first dividing gaps 41 are not the same. The vertical center line of the width of the first dividing gap 41 and the vertical center line of the width of the second dividing gap 42 can be on the same straight line or not on the same straight line, so that the dividing gaps 4 formed on each layer are discontinuous, thereby forming a variety of gap structures. This setting can improve the applicability of the matching layer 3.

[0117] As an example, let's take the case where the vertical center line of the width of the second dividing gap 42 is on the same straight line as the vertical center line of the width of the first dividing gap 41.

[0118] When the widths of both first dividing gaps 41 are greater than the width of the second dividing gap 42, a first type of gap structure is formed;

[0119] When the widths of the two first dividing gaps 41 are both smaller than the width of the second dividing gap 42, a second type of gap structure is formed;

[0120] When the width of the second dividing gap 42 is greater than the width of either of the two first dividing gaps 41, a third gap structure is formed.

[0121] When the width of the second dividing gap 42 is equal to the width of either of the two first dividing gaps 41, a fourth gap structure and a fifth gap structure are formed.

[0122] All five gap structures described above can cause at least two matching layers 3 of the piezoelectric structure to have discontinuous changes in the vertical direction. Different gap structures are used to adjust the acoustic impedance of the matching layer 3 to obtain a better bandwidth, thereby improving the imaging effect.

[0123] In one embodiment, reference is made to Figure 1-6 A filling layer is provided inside the dividing gap 4.

[0124] As an example, a filling layer is provided in the dividing gap 4. Different filling layers result in different ultrasonic transducer performance. For example, the filling layer can be made of silicone rubber, epoxy resin or air. The piezoelectric structure forms a structure similar to a composite material, realizing the function of adjusting the sound velocity and density of each layer of material, making the acoustic impedance matching more suitable, and the ultrasonic transducer obtains better echo spectrum performance.

[0125] This invention provides an ultrasonic transducer, referring to... Figure 1-7 It includes a base plate 5 and at least two piezoelectric structures disposed on the base plate 5, with a gap between adjacent piezoelectric structures.

[0126] As an example, the ultrasonic transducer base plate 5 has at least two piezoelectric structures bonded to it, with gaps between adjacent structures. Each piezoelectric structure includes a vibration unit. The at least two vibration units are arranged side-by-side at intervals along a horizontal direction. Each vibration unit includes a backing layer 1, a piezoelectric layer 2, and at least two matching layers 3 disposed on the piezoelectric layer 2. The at least two matching layers 3 have different vertical projection dimensions, creating at least two dividing gaps 4 in the vertical direction. There is at least one set of adjacent dividing gaps 4 with different widths. The piezoelectric layer 2 is disposed on the backing layer 1. Because the acoustic impedance of the piezoelectric layer 2 and the object under test often differs significantly, most ultrasonic waves are reflected, resulting in low transmittance of ultrasonic waves from the vibration unit to human tissue. This affects the efficiency of the vibration unit in receiving ultrasonic waves of different frequencies, increasing the bandwidth of the ultrasonic transducer. By placing at least two matching layers 3 with different acoustic impedances on the piezoelectric layer 2, the transmittance is affected by the thickness of the matching layers 3 and the wavelength of the ultrasonic waves. The effect can increase sound output or decrease sound attenuation, thereby reducing the leakage of the detection signal of the vibration unit, improving the performance of the vibration unit, improving the sound wave propagation efficiency, and thus increasing the bandwidth of the ultrasonic transducer, which can cover the frequency range of the fundamental wave and higher harmonics, and achieve better harmonic imaging effect; the number of matching layers 3 can be selected according to actual needs, without the need for special processing of the thickness of the matching layers 3 according to the structure of the piezoelectric layer 2, thereby reducing the processing difficulty of the ultrasonic transducer; at least one set of two adjacent matching layers 3 have different projection dimensions in the vertical direction. According to the different sound velocities when the acoustic materials of each layer are in the large-size sheet form, when the vibration unit has N matching layers 3, N-1 sets of adjacent matching layers 3 will be formed. In the N-1 sets of adjacent matching layers 3, there will be 1 to N-1 sets of adjacent matching layers 3 with different projection dimensions in the vertical direction. This setting makes the dividing gap 4 formed on each layer non-continuous when at least two vibration units are set side by side, thereby forming various forms of gap structures, such as V-shaped gap structures, The gap structure can be shaped like a dome, a spindle, or an X. It can also be configured such that the vertical center line of at least one matching layer 3 does not coincide with the vertical center line of the piezoelectric layer 2. In this way, according to the different sound velocities of the large-size sheet-like acoustic materials in each layer of the vibration unit, the dividing gap 4 formed on each layer can be discontinuous when at least two vibration units are set side by side, thus forming a variety of gap structures. This configuration can improve the applicability of the matching layer 3, making it suitable for both traditional piezoelectric block ultrasonic transducers and microelectromechanical processing ultrasonic transducers, such as c-MUT and p-MUT transducers.

[0127] This invention provides a method for manufacturing an ultrasonic transducer, referring to... Figure 2-6 This includes the following steps:

[0128] S1: The backing layer 1, the piezoelectric layer 2 and at least one matching layer 3 are bonded together in sequence to obtain the first element, and the first element is cut to form a dividing gap 4.

[0129] S2: Repeat the process at least once; attach a matching layer 3 to the first element after cutting, cut the matching layer 3 to form another dividing gap 4 corresponding to a dividing gap 4; wherein at least two dividing gaps 4 are formed in the vertical direction, and there is at least one set of two adjacent dividing gaps 4 with different widths.

[0130] As an example, in step S1, the backing layer 1, the piezoelectric layer 2, and at least one matching layer 3 are sequentially bonded to obtain a first element. Then, the first element is cut using a dicing machine or other cutting equipment to form a segmentation gap 4, dividing it into independent vibration units. The width of the vibration unit is no more than twice the wavelength corresponding to the working frequency, and the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which can improve the vibration performance and acoustic performance of the vibration unit. The width of the segmentation gap 4 is no greater than 200 μm, and the width of the vibration unit is no greater than twice the wavelength corresponding to the working frequency (e.g., 15 MHz), i.e., no greater than 200 μm, which can obtain better acoustic performance, such as improved frequency band and improved time-domain waveform. At the same time, the directivity of the vibration unit is improved, the side lobes are reduced, avoiding affecting the resolution of the ultrasonic image; improving the sensitivity and imaging effect of the ultrasonic transducer. The first element can be cut twice to form two different widths of segmentation gap 4. The depths of the two segmentation gaps 4 are designed according to actual needs and can be the same or different.

[0131] As an example, step S2 can be repeated at least once according to actual needs. When step S2 is performed once, a matching layer 3 is bonded to the cut first element using an adhesive mold, and the matching layer 3 is cut to form another dividing gap 4 corresponding to the first dividing gap 4. There is at least one set of adjacent dividing gaps 4 with different widths. When step S2 is performed twice, a matching layer 3 is bonded to the cut first element using an adhesive mold, and the matching layer is cut to form another dividing gap 4 corresponding to the first dividing gap 4. Then the first element is obtained, and a matching layer 3 is bonded to the cut first element again using an adhesive mold. The matching layer is cut to form yet another dividing gap 4 corresponding to the other dividing gap 4. At least two dividing gaps 4 are formed in the vertical direction, and there is at least one set of adjacent dividing gaps 4 with different widths. This allows the dividing gaps 4 formed on each layer to be discontinuous, thereby forming various forms of gap structures and improving the applicability of the matching layer 3.

[0132] In this example, the ultrasonic transducer is manufactured using the following five methods:

[0133] First reference Figure 2 The backing layer 1, piezoelectric layer 2, and first matching layer 31 are sequentially bonded to obtain a first element. Then, a dicing machine or other cutting equipment is used to cut the first element to form a first dividing gap 41, dividing it into independent vibration units. The width of the vibration unit does not exceed twice the wavelength corresponding to the working frequency, and the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which can improve the vibration performance and acoustic performance of the vibration unit. The width of the first dividing gap 41 is not greater than 200um. Then, the second matching layer 32 is bonded to the cut first element using an adhesive mold, and the matching layer 3 is cut to form a second dividing gap 42 corresponding to the first dividing gap 41.

[0134] Specifically, when a blade or other cutting device with a width smaller than the first dividing gap 41 is selected to cut the second matching layer 32, the second dividing gap 42 is obtained, resulting in a kerf gap structure. Alternatively, a blade or other cutting device with a width greater than the first dividing gap 41 can be selected to cut the second matching layer 32 to obtain the second dividing gap 42, making the cutting gap structure V-shaped, thereby obtaining the second matching layer 32 with a relatively low sound velocity.

[0135] The second reference Figure 3The backing layer 1, piezoelectric layer 2, and first matching layer 31 are sequentially bonded together to obtain a first element. Then, a dicing machine or other cutting equipment is used to cut the first element to form a first dividing gap 41, dividing it into independent vibration units. The width of the vibration unit does not exceed twice the wavelength corresponding to the working frequency, and the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which can improve the vibration performance and acoustic performance of the vibration unit. The width of the first dividing gap 41 is not greater than 200um. Then, the second matching layer 32 is bonded to the cut first element using an adhesive mold, and the matching layer 3 is cut to form a second dividing gap 42 corresponding to the first dividing gap 41.

[0136] Specifically, when a blade or other cutting device with a width smaller than the first dividing gap 41 is selected to cut the second matching layer 32 to obtain the second dividing gap 42, the vertical center line of the first dividing gap 41 and the vertical center line of the second dividing gap 42 are not on the same straight line, making the cutting gap structure non-axisymmetric. Alternatively, a blade or other cutting device with a width greater than the first dividing gap 41 can be selected to cut the second matching layer 32 to obtain the second dividing gap 42, and the vertical center line of the first dividing gap 41 and the vertical center line of the second dividing gap 42 are not on the same straight line, making the cutting gap structure non-axisymmetric.

[0137] The third reference Figure 4 The backing layer 1, piezoelectric layer 2, and first matching layer 31 are sequentially bonded to obtain a first element. Then, a dicing machine or other cutting equipment is used to cut the first element, forming a first dividing gap 41 to separate independent vibration units. The width of each vibration unit is no more than twice the wavelength corresponding to the working frequency, and the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which improves the vibration and acoustic performance of the vibration units. The width of the first dividing gap 41 is no greater than 200 μm. Using a dicing machine or other cutting equipment, the independent vibration units are further divided to form a first dividing gap 41 of another width. The width of the first dividing gap 41 formed by the second cut can be greater or less than the width of the first dividing gap 41 formed by the first cut. The depth of the first dividing gap 41 formed by the second cut can be the same as or different from the depth of the first dividing gap 41 formed by the first cut. Then, a gluing mold is used to bond the second matching layer 32 to the cut first element, and the matching layer 32 is cut to form a second dividing gap 42 corresponding to the first dividing gap 41.

[0138] The following example illustrates that the width of the first dividing gap 41 formed by the second cut is different from the width of the first dividing gap 41 formed by the first cut, and the vertical center line of the width of the second dividing gap 42 is on the same straight line as the vertical center line of the width of the first dividing gap 41: Select a blade or other cutting device that is smaller than the width of the first dividing gap 41 formed by the second cut and the width of the first dividing gap 41 formed by the first cut, cut the second matching layer 32, and obtain the second dividing gap 42 to form the first type of gap structure;

[0139] Select a blade or other cutting device that is wider than the width of the first dividing gap 41 formed by the second cut and the width of the first dividing gap 41 formed by the first cut, cut the second matching layer 32 to obtain the second dividing gap 42, so as to form the second gap structure.

[0140] Select a blade or other cutting device with a width between the width of the first dividing gap 41 formed by the second cut and the width of the first dividing gap 41 formed by the first cut, cut the second matching layer 32 to obtain the second dividing gap 42, so as to form the third gap structure;

[0141] Select a blade or other cutting device that is equal to the width of the first dividing gap 41 formed by the second cut or the width of the first dividing gap 41 formed by the first cut, cut the second matching layer 32 to obtain the second dividing gap 42, so as to form the fourth gap structure and the fifth gap structure.

[0142] The fourth reference Figure 5 The backing layer 1, piezoelectric layer 2, and first matching layer 31 are sequentially bonded together to obtain a first element. Then, a dicing machine or other cutting equipment is used to cut the first element to form a first dividing gap 41, dividing it into independent vibration units. The width of the vibration unit does not exceed twice the wavelength corresponding to the working frequency, and the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which can improve the vibration performance and acoustic performance of the vibration unit. The width of the first dividing gap 41 is not greater than 200um. Then, the second matching layer 32 is bonded to the cut first element using an adhesive mold, and the matching layer 3 is cut to form a second dividing gap 42 corresponding to the first dividing gap 41.

[0143] Specifically, when a blade or other cutting device with a width smaller than the first dividing gap 41 is selected to cut the second matching layer 32, the second dividing gap 42 is obtained, resulting in a kerf gap structure. The first element is cut to obtain a second matching layer 32 with a relatively high sound velocity. Alternatively, a blade or other cutting device with a width greater than the first dividing gap 41 can be selected to cut the second matching layer 32 to obtain a second dividing gap 42, so that the cutting gap structure is V-shaped, and a second matching layer 32 with a relatively low sound velocity is obtained. Then, the third matching layer 33 is bonded to the cut first element using an adhesive mold, and the matching layer 3 is cut to form a third dividing gap 43 corresponding to the second dividing gap 42.

[0144] When the second dividing gap 42 is greater than the first dividing gap 41 and the third dividing gap 43 is greater than the second dividing gap 42, the slit gap structure is V-shaped, resulting in a third matching layer 33 with relatively low sound velocity.

[0145] When the second dividing gap 42 is greater than the first dividing gap 41 and the third dividing gap 43 is less than the second dividing gap 42, the slit gap structure is made to be spindle-shaped, and a third matching layer 33 with relatively high sound velocity is obtained.

[0146] When the second dividing gap 42 is smaller than the first dividing gap 41 and the third dividing gap 43 is larger than the second dividing gap 42, the slit gap structure is X-shaped, resulting in a relatively low sound velocity third matching layer 33.

[0147] When the second dividing gap 42 is smaller than the first dividing gap 41, and the third dividing gap 43 is smaller than the second dividing gap 42, the slit gap structure is such that... The shape allows for the acquisition of a third matching layer 33 with relatively high sound speeds.

[0148] Fifth reference Figure 6 The backing layer 1, piezoelectric layer 2, first matching layer 31, and second matching layer 32 are sequentially bonded together to obtain a first element. Then, a dicing machine or other cutting equipment is used to cut the first element to form a first dividing gap 41, dividing it into independent vibration units. The width of the vibration unit does not exceed twice the wavelength corresponding to the working frequency, and the aspect ratio of the piezoelectric layer 2 is less than or equal to 2, which can improve the vibration performance and acoustic performance of the vibration unit. The width of the first dividing gap 41 is not greater than 200um. Then, a gluing mold is used to bond the third matching layer 33 to the cut first element, and the matching layer 3 is cut to form a third dividing gap 43 corresponding to the first dividing gap 41.

[0149] Specifically, when a blade or other cutting device with a width smaller than the first dividing gap 41 is selected, the third matching layer 33 is cut to obtain the third dividing gap 43, resulting in a kerf gap structure. The shape is such that a third matching layer 33 with relatively high sound speed is obtained;

[0150] When a blade or other cutting device with a width greater than the first dividing gap 41 is selected, the third matching layer 33 is cut to obtain the third dividing gap 43, so that the cutting gap structure is V-shaped, and a relatively low sound velocity third matching layer 33 is obtained.

[0151] In addition to the above solutions, the materials to be cut and the width order of the gaps 4 between the cut materials can be customized according to the acoustic impedance matching of the materials. The above solutions only list the main structures of the ultrasonic transducer, namely the piezoelectric layer, backing layer, matching layer, and outermost acoustically transparent layer, which have a significant impact on the acoustic performance of the transducer's vibration unit. In practical applications, the circuit boards or soft conductive materials leading out the positive and negative terminals of the vibration unit circuit will be located at any one or two interfaces of the piezoelectric layer, backing layer, matching layer, and acoustically transparent layer, and this ultrasonic transducer structure is still included within the scope of protection of this invention.

[0152] In one embodiment, the method for manufacturing an ultrasonic transducer further includes:

[0153] S3: Fill the filler layer within at least two dividing gaps to form a second element;

[0154] S4: The outermost acoustic layer is bonded in the second element.

[0155] As an example, in step S3, a filling layer is filled in at least two dividing gaps to form a second element; different filling layers result in different ultrasonic transducer performance. For example, the filling layer can be silicone rubber, epoxy resin or air, and the piezoelectric structure forms a structure similar to a composite material, realizing the function of adjusting the sound velocity and density of each layer of material, making the acoustic impedance matching more suitable, and the ultrasonic transducer obtains better echo spectrum performance.

[0156] As an example, in step S4, a sound-transmitting layer is bonded to the outermost side of the second element. This layer is placed on the outermost matching layer 3 and serves to focus the ultrasonic signal and protect the ultrasonic transducer. Finally, the entire element is placed on the base plate 5 to obtain a complete ultrasonic transducer.

[0157] In one embodiment, the bonding pressure between two adjacent matching layers 3 is 0.05 MPa to 2.0 MPa.

[0158] As an example, the bonding pressure between two adjacent matching layers 3 is 0.05MPa~2.0MPa, which defines the bonding pressure range to ensure that the segmented vibration unit is not crushed by excessive pressure, nor that the bonding adhesive layer is too thick due to insufficient pressure, thus affecting the acoustic performance.

[0159] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A piezoelectric structure, characterized in that, Includes vibration units; The vibration unit includes a backing layer, a piezoelectric layer, and at least two matching layers with different acoustic impedances, wherein the piezoelectric layer is disposed on the backing layer; At least two matching layers are disposed on the piezoelectric layer, and at least one set of two adjacent matching layers have different vertical center lines; At least two vibration units are arranged side by side at intervals in a horizontal direction, and each vibration unit includes a backing layer, a piezoelectric layer and at least two matching layers disposed on the piezoelectric layer; At least one set of two adjacent matching layers have different vertical center lines, so that in the piezoelectric structure forming at least two dividing gaps in the vertical direction, there is at least one set of two adjacent dividing gaps whose vertical center lines are not on the same straight line; The widths of two adjacent dividing gaps whose vertical center lines are not on the same straight line are either the same or different.

2. The piezoelectric structure according to claim 1, characterized in that, Each of the vibration units includes at least three matching layers, and there is at least one set of adjacent matching layers with the same projection size in the vertical direction, so that in the at least two dividing gaps formed by the piezoelectric structure in the vertical direction, there is at least one set of adjacent dividing gaps with the same width, and the vertical center lines of the adjacent dividing gaps with the same width are either on the same straight line or not on the same straight line.

3. The piezoelectric structure according to claim 1, characterized in that, The matching layer includes a first matching layer and a second matching layer; The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers; The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers; The width of the second dividing gap is not equal to the width of the first dividing gap.

4. The piezoelectric structure according to claim 1, characterized in that, The matching layer includes a first matching layer and a second matching layer; The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers; The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers; The vertical center line of the first dividing gap and the vertical center line of the second dividing gap are not on the same straight line.

5. The piezoelectric structure according to claim 1, characterized in that, The matching layer includes a first matching layer, a second matching layer, and a third matching layer; The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers; The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers; The third matching layer is disposed on the second matching layer, and a third dividing gap is formed between two adjacent third matching layers; The width of the first dividing gap is not equal to the width of the second dividing gap, and / or the width of the second dividing gap is not equal to the width of the third dividing gap.

6. The piezoelectric structure according to claim 1, characterized in that, The matching layer includes a first matching layer, a second matching layer, and a third matching layer; The first matching layer is disposed on the piezoelectric layer, and a first dividing gap is formed between two adjacent first matching layers in the horizontal direction, which is equal to the piezoelectric dividing gap formed between two adjacent piezoelectric layers; The second matching layer is disposed on the first matching layer, and a second dividing gap is formed between two adjacent second matching layers; The third matching layer is disposed on the second matching layer, and a third dividing gap is formed between two adjacent third matching layers; The vertical center line of the first dividing gap is not on the same straight line as the vertical center line of the second dividing gap, and / or the vertical center line of the second dividing gap is not on the same straight line as the vertical center line of the third dividing gap.

7. The piezoelectric structure according to any one of claims 3-6, characterized in that, The widths of two adjacent first dividing gaps along the horizontal direction are either different or the same.

8. The piezoelectric structure according to claim 1, characterized in that, The dividing gap is filled with a filling layer.

9. The piezoelectric structure according to claim 1, characterized in that, The acoustic impedance of at least two of the matching layers gradually decreases, and the acoustic impedance of the matching layer closer to the piezoelectric layer is greater than that of the matching layer farther away from the piezoelectric layer.

10. The piezoelectric structure according to claim 1, characterized in that, The width of the vibration unit is no greater than twice the wavelength corresponding to the operating frequency; The width of the vibration unit is the width of the projected area of ​​the piezoelectric layer in the vertical direction.

11. The piezoelectric structure according to claim 1, characterized in that, The aspect ratio of the piezoelectric layer is no greater than 2.

12. The piezoelectric structure according to claim 1, characterized in that, The vibration unit also includes a sound-permeable layer, which is disposed on the outermost matching layer.

13. An ultrasonic transducer, characterized in that, It includes a base plate and at least two piezoelectric structures according to any one of claims 1-12 disposed on the base plate, with a gap between adjacent piezoelectric structures.

14. A method for manufacturing an ultrasonic transducer, characterized in that, Includes the following steps: A backing layer, a piezoelectric layer, and at least one matching layer are sequentially bonded together to obtain a first element. The first element is then cut to form a dividing gap. Repeat the process at least once; adhere a matching layer to the first element after cutting, and cut the matching layer to form another dividing gap; In this configuration, at least two dividing gaps are formed in the vertical direction, and there exists at least one set of two adjacent dividing gaps whose vertical center lines are not on the same straight line.

15. The method for manufacturing an ultrasonic transducer according to claim 14, characterized in that, The method for manufacturing the ultrasonic transducer further includes: A filler layer is filled into at least two of the said dividing gaps to form a second element; An acoustically permeable layer is bonded to the outermost side of the second element.

16. The method for manufacturing an ultrasonic transducer according to claim 14, characterized in that, The bonding pressure between two adjacent matching layers is 0.05MPa~2.0MPa.

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