CN117545338A - Technological manufacturing method of ultrasonic transducer and ultrasonic transducer - Google Patents

Technological manufacturing method of ultrasonic transducer and ultrasonic transducer Download PDF

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Publication number
CN117545338A
CN117545338A CN202311539792.5A CN202311539792A CN117545338A CN 117545338 A CN117545338 A CN 117545338A CN 202311539792 A CN202311539792 A CN 202311539792A CN 117545338 A CN117545338 A CN 117545338A
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piezoelectric
ultrasonic transducer
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conductive layer
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
    • A61B8/4483—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/01—Manufacture or treatment
    • H10N30/08—Shaping or machining of piezoelectric or electrostrictive bodies
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/01—Manufacture or treatment
    • H10N30/09—Forming piezoelectric or electrostrictive materials
    • H10N30/092—Forming composite materials
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/20—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/80—Constructional details
    • H10N30/85—Piezoelectric or electrostrictive active materials
    • H10N30/852—Composite materials, e.g. having 1-3 or 2-2 type connectivity

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
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  • Chemical & Material Sciences (AREA)
  • Medical Informatics (AREA)
  • General Health & Medical Sciences (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Molecular Biology (AREA)
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  • Animal Behavior & Ethology (AREA)
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  • Veterinary Medicine (AREA)
  • Biophysics (AREA)
  • Physics & Mathematics (AREA)
  • Gynecology & Obstetrics (AREA)
  • Mechanical Engineering (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)

Abstract

The invention provides a process manufacturing method of an ultrasonic transducer and the ultrasonic transducer, wherein the process manufacturing method comprises the following steps: step S1, rolling a piezoelectric ceramic raw material into a viscous polymerization state; s2, coating a viscous aggregation state piezoelectric ceramic raw material on the surface of a lining plate by a centrifugal spin coating method to form a piezoelectric layer; step S3, molding a mold with holes arranged in an array on the piezoelectric layer to enable the piezoelectric layer to be provided with a plurality of piezoelectric columns arranged in an array; step S4, placing the lining plate and the molded piezoelectric layer in a vacuum environment to sinter and form piezoelectric ceramics; step S5: preparing a bottom plate plated with a first metal conductive layer, and connecting one end of a piezoelectric column to the first metal conductive layer; step S6: polishing one surface of the piezoelectric ceramic, which is away from the first metal conductive layer, until the piezoelectric column is exposed; step S7: and a layer of second conductive metal is arranged at one end of the piezoelectric column, which is far away from the first metal conductive layer. The process manufacturing method can achieve the purpose of improving the picture resolution of medical ultrasonic imaging.

Description

Technological manufacturing method of ultrasonic transducer and ultrasonic transducer
The invention relates to the field of medical device rings, in particular to a process manufacturing method of an ultrasonic transducer and the ultrasonic transducer.
Background
The piezoelectric micromachined ultrasonic transducer (Piezoelectric Micromachined Ultrasonic Transducer, PMUT) is a novel ultrasonic transducer manufactured based on MEMS technology, and has the characteristics of integration, miniaturization, high sensitivity, easy integration with a circuit and realization of intelligent application. Compared with the traditional bulk wave ultrasonic transducer, the PMUT ultrasonic transducer can be well compatible with CMOS and ASIC circuits. The piezoelectric layer material of the conventional PMUT ultrasonic transducer is piezoelectric ceramics (PZT), piezoelectric films (PVDF), aluminum nitride, scandium-doped aluminum nitride or silicon nitride; in medical diagnostic ultrasound applications, the relatively low bandwidth (about 30%) of the commonly used PMUT transducers results in poor image quality and low spatial resolution, which makes it difficult to meet the high resolution requirements of medical ultrasound imaging (e.g., intracardiac ultrasound (ICE), intravascular ultrasound (IVUS)).
The piezoelectric layer material for manufacturing the PMUT ultrasonic transducer can be divided into two types according to the implementation principle and the process temperature: (1) High temperature chemical solution deposition (2) low temperature physical pulse laser deposition (magnetron sputtering). The piezoelectric layer structures formed by the two methods are single-phase piezoelectric film materials, and for manufacturing an ultrasonic transducer with high sensitivity and wide bandwidth, the acoustic impedance of the piezoelectric layer material is high, so that acoustic impedance matching is not easy to form with human tissues, the manufactured transducer has low relative bandwidth, and the spatial resolution (including transverse resolution and longitudinal resolution) of an image is low.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a process manufacturing method of an ultrasonic transducer and the ultrasonic transducer so as to achieve the aim of improving the picture resolution of medical ultrasonic imaging.
To this end, according to a first aspect, in one embodiment there is provided a process manufacturing method of an ultrasonic transducer, comprising:
step S1, rolling a piezoelectric ceramic raw material into a viscous polymerization state;
s2, coating a viscous aggregation state piezoelectric ceramic raw material on the surface of a lining plate by a centrifugal spin coating method to form a piezoelectric layer;
step S3, a die with holes arranged in an array is molded on the piezoelectric layer to enable the piezoelectric layer to be provided with a plurality of piezoelectric columns arranged in an array, and then the die is removed;
s4, placing the lining plate and the molded piezoelectric layer in a vacuum environment, and sintering at high temperature to form piezoelectric ceramics;
step S5: preparing a bottom plate plated with a first metal conductive layer, and connecting one end of the piezoelectric column to the first metal conductive layer;
step S6: polishing one surface of the piezoelectric ceramic, which faces away from the first metal conducting layer, until the piezoelectric column is exposed;
step S7: and a layer of second conductive metal is arranged at one end of the piezoelectric column, which is far away from the first metal conductive layer.
As a further alternative of the process manufacturing method of the ultrasonic transducer, the step 4 further includes filling a soft material, heating and melting the soft material, filling the soft material into the gaps between the piezoelectric columns, vacuumizing to remove bubbles in the soft material, and grinding the redundant soft material until the piezoelectric columns are exposed after the soft material is cooled and shaped.
In a second aspect, the present invention provides an ultrasonic transducer manufactured by the process manufacturing method of the ultrasonic transducer of the first aspect, where the ultrasonic transducer includes a second metal conductive layer, a piezoelectric layer, a first metal conductive layer, and a bottom plate sequentially disposed from top to bottom, and the piezoelectric layer includes the piezoelectric columns arranged in an array.
As a further alternative to the ultrasonic transducer, the second metal conductive layer covers only a portion of the piezoelectric pillars.
As a further alternative to the ultrasonic transducer, the piezoelectric ceramic raw material is a lead zirconate titanate mixture.
As a further alternative to the ultrasonic transducer, the first and second metal conductive layers are made of aluminum.
As a further alternative to the ultrasonic transducer, the piezoelectric pillars have a height of 3 micrometers to 30 micrometers.
As a further alternative to the ultrasonic transducer, the soft material is an epoxy.
As a further alternative to the ultrasound transducer, the bottom plate has a back cavity.
As a further alternative to the ultrasonic transducer, the bottom plate is a silicon plate.
The implementation of the embodiment of the invention has the following beneficial effects: according to the process manufacturing method of the ultrasonic transducer in the above embodiment, the piezoelectric ceramic raw material is pressed into a viscous polymerized state (viscous polymer) by a roll method. The particles formed by the adhesive polymer are finer, are not easy to agglomerate and generate larger gaps. Centrifugal spin coating is adopted to enable the piezoelectric ceramic raw material to form a compact coating between the surfaces of the lining plates, and after die pressing, the piezoelectric ceramic raw material is enabled to form a 1-3 type composite material structure. The 1-3 type composite material is formed by three-dimensionally communicated polymer phases which are formed by parallelly arranging one-dimensionally communicated piezoelectric ceramic phases, so that the weakness of the ceramic in the aspect of strength and brittleness can be effectively reduced, the transverse coupling of the ceramic is reduced, and the longitudinal electromechanical conversion efficiency of the composite material is increased. And has low acoustic impedance, and is easy to be matched with water, skin and other mediums. The device also has the characteristics of small dielectric constant and small electrostatic capacitance, so that the impedance required to be input is higher when the transducer works, and the device has higher sensitivity to receiving voltage. The piezoelectric layer of the ultrasonic transducer formed by the final piezoelectric ceramic has a 1-3 composite material structure, so the process manufacturing method of the ultrasonic transducer in the embodiment can achieve the aim of improving the picture resolution of medical ultrasonic imaging.
According to the ultrasonic transducer in the above embodiment, since the piezoelectric layer has the 1-3 type composite structure, the ultrasonic transducer has all the advantages of the 1-3 type composite structure, so that the purpose of improving the picture resolution of medical ultrasonic imaging can be achieved.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Wherein:
fig. 1 is a process diagram showing a process manufacturing method of an ultrasonic transducer according to an embodiment of the present invention;
fig. 2 shows a process flow chart of a process manufacturing method of an ultrasonic transducer according to an embodiment of the invention.
Description of main reference numerals:
a second metal conductive layer-10; a piezoelectric layer-20; a first metal conductive layer-30; a bottom plate-40; a piezoelectric column-210; soft material-50; back cavity-410; raw material of piezoelectric ceramics-60; three-roller machine-70; a lining board-80; and (5) a mold-90.
Description of the embodiments
In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.
Unless otherwise defined, all technical and scientific terms used herein and belonging to the techniques of this invention
The meaning is generally understood by those skilled in the art. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
In a first aspect, in an embodiment of the present invention, a process manufacturing method of an ultrasonic transducer is provided, referring to fig. 1 and fig. 2, where the process manufacturing method of an ultrasonic transducer includes:
step S1, rolling a piezoelectric ceramic raw material 60 into a viscous polymerization state;
step S2, coating the viscous aggregation state piezoelectric ceramic raw material 60 on the surface of a lining plate 80 by a centrifugal spin coating method to form a piezoelectric layer 20;
step S3, after the die 90 with the holes arranged in array is molded on the piezoelectric layer 20 to enable the piezoelectric layer 20 to be provided with a plurality of piezoelectric columns 210 arranged in array, the die 90 is removed;
step S4, placing the lining plate 80 and the molded piezoelectric layer 20 in a vacuum environment and sintering at high temperature to form piezoelectric ceramics;
step S5: preparing a base plate 40 plated with a first metal conductive layer 30, and connecting one end of a piezoelectric column 210 to the first metal conductive layer 30;
step S6: polishing the side of the piezoelectric ceramic facing away from the first metal conductive layer 30 until the piezoelectric pillars 210 are exposed;
step S7: a layer of a second conductive metal is disposed at an end of the piezoelectric column 210 facing away from the first metal conductive layer 30.
According to the process manufacturing method of the ultrasonic transducer in the above embodiment, the piezoelectric ceramic raw material 60 is pressed into a viscous polymerized state (viscous polymer) by a roll pressing method. The particles formed by the adhesive polymer are finer, are not easy to agglomerate and generate larger gaps. Centrifugal spin coating causes the piezoelectric ceramic raw material 60 to form a dense coating between the surfaces of the lining plates 80, and after compression molding, the piezoelectric ceramic raw material 60 forms a 1-3 composite structure. The 1-3 type composite material is formed by three-dimensionally communicated polymer phases which are formed by parallelly arranging one-dimensionally communicated piezoelectric ceramic phases, so that the weakness of the ceramic in the aspect of strength and brittleness can be effectively reduced, the transverse coupling of the ceramic is reduced, and the longitudinal electromechanical conversion efficiency of the composite material is increased. And has low acoustic impedance, and is easy to be matched with water, skin and other mediums. The device also has the characteristics of small dielectric constant and small electrostatic capacitance, so that the impedance required to be input is higher when the transducer works, and the device has higher sensitivity to receiving voltage. The piezoelectric layer 20 of the final piezoelectric ceramic-formed ultrasonic transducer has a 1-3 composite material structure, so that the process manufacturing method of the ultrasonic transducer in the embodiment can achieve the purpose of improving the picture resolution of medical ultrasonic imaging.
The chemical deposition method has a simple process, and is specifically classified into a high-temperature chemical deposition method and a low-temperature chemical deposition method. Among them, the low-temperature chemical deposition method is low in cost, simple in process, but poor in uniformity of the formed piezoelectric layer 20. While the high-temperature chemical deposition method has simple process and good uniformity of the formed piezoelectric layer 20, the production equipment is expensive, and the production cost is greatly increased. Physical pulse laser deposition, while also having the advantage of simple process and high uniformity of the formed piezoelectric layer 20, is also very expensive to produce.
In this embodiment, all processes can be realized by providing a reaction kettle, a roller press, a centrifugal spin-coating device and a polishing device with a vacuum environment. In step S3, the thickness of the piezoelectric layer 20 is substantially uniform by the molding of the mold 90, so the process method of the present invention combines the advantages of low production cost, simple process, and uniform thickness uniformity of the piezoelectric layer 20.
Generally, the process requirements of the present invention are met by selecting a three-roll machine 70 for the roll press in step S1.
In some specific embodiments, step 4 further includes filling the soft material 50, heating and melting the soft material 50, filling the soft material 50 into the gaps between the piezoelectric pillars 210, vacuumizing to remove bubbles in the soft material 50, waiting for cooling and shaping the soft material 50, and grinding off the redundant soft material 50 until the piezoelectric pillars 210 are exposed.
In the present embodiment, the filling of the soft material 50 in the gaps between the piezoelectric pillars 210 mainly serves the following purpose. First, the soft material 50 can serve as a support reinforcement to avoid insufficient strength of the piezoelectric pillars 210 or poor support of the metal conductive layer. Second, the soft material 50 can reduce the acoustic impedance of the piezoelectric layer 20, so that the resulting driven transducer is easily matched with human tissue, thereby increasing the bandwidth of the ultrasonic transducer and improving spatial resolution. That is, the soft material 50 can suppress the vibration of the piezoelectric layer 20 in the lateral direction to some extent.
The soft material 50 is selected based on Shore hardness, which is usedThe reading of the measured values, in units of "degrees", describes two methods, A, D, respectively representing different hardness ranges, < >>The measurement range of (C) is 0-100HA, shore D +.>The range of (2) is 0-100HD. The soft material 50 in the present invention may be selected from materials with low shore hardness such as rubber and plastic.
In a second aspect, referring to fig. 1, in an embodiment of the present invention, there is provided an ultrasonic transducer manufactured by the process manufacturing method of the ultrasonic transducer of the first aspect, including a second metal conductive layer 10, a piezoelectric layer 20, a first metal conductive layer 30 and a bottom plate 40 sequentially disposed from top to bottom, wherein the piezoelectric layer 20 includes piezoelectric columns 210 arranged in an array.
According to the ultrasonic transducer in the above embodiment, since the piezoelectric layer 20 has a 1-3 type composite structure, the ultrasonic transducer has all the advantages of the 1-3 type composite structure, so that the purpose of improving the picture resolution of medical ultrasonic imaging can be achieved.
It should be noted that the shape of the piezoelectric column 210 may be various, for example, a cylindrical, cubic or polygonal column, and the like.
In some specific embodiments, the second metal conductive layer 10 covers only a portion of the piezoelectric pillars 210.
In the present embodiment, the second metal conductive layer 10 covers only a part of the piezoelectric pillars 210, so that vibration suppression of the piezoelectric layer 20 in the longitudinal direction can be avoided to the greatest extent. A potential difference is formed between the second metal conductive layer 10 and the first metal conductive layer 30, so that the piezoelectric pillars 210 can be energized even though some of the piezoelectric pillars 210 are not covered with the second metal conductive layer 10. The piezoelectric column 210 starts vibrating upon energization, thereby generating ultrasonic waves.
In certain embodiments, the piezoelectric ceramic starting material 60 is a lead zirconate titanate mixture. In current PMUT ultrasonic transducers, the piezoelectric layer 20 is typically made of piezoelectric ceramics (PZT), PMN-PT, zinc oxide (ZnO), aluminum nitride (AlN), scandium-doped aluminum nitride (scann), polyvinylidene fluoride (PVDF), or the like, having a thickness of several micrometers to several tens of micrometers. The materials of the vibrating membrane are PZT and ZnO, the acoustic impedance value of the piezoelectric film materials is high, the acoustic impedance of the PZT piezoelectric ceramic is 30MRayls, and the acoustic impedance value of the ZnO material is above 20 MRayls.
Lead zirconate titanate(lead zirconate titanate piezoelectric ceramics) is of the formula->(Zr 1-xTix) O3->Piezoelectric ceramics belonging to->. It is essentially one of PZT piezoelectric ceramics.
In medical diagnostic ultrasound applications, the relatively low bandwidth (about 30%) of the commonly used PMUT transducers results in poor image quality and low spatial resolution, which makes it difficult to meet the high resolution requirements of medical ultrasound imaging (e.g., intracardiac ultrasound (ICE), intravascular ultrasound (IVUS)). The high-bandwidth PMUT ultrasonic transducer based on viscous polymer processing can improve the relative bandwidth (more than 60%) of the PMUT ultrasonic transducer, and has the advantages of high sensitivity of the PMUT ultrasonic transducer and wide bandwidth of the piezoelectric composite material.
Note that the base plate 40 and the liner plate 80 in fig. 1 are identical, and the base plate 40 and the liner plate 80 may be identical or different in composition, and fig. 1 is merely for convenience of illustration and understanding.
In some specific embodiments, the first and second metal conductive layers 30 and 10 are made of aluminum.
Aluminum is a conductive metal, and is lighter than other metals, and can avoid suppressing vibration of the piezoelectric layer 20 in the longitudinal direction. In addition, the process of aluminum electroplating is also very mature, and the electroplating effect is better than that of other conductive metals.
In some specific embodiments, the height of the piezoelectric pillars 210 is 3 microns-30 microns.
The piezoelectric pillars 210 have a height of 3 micrometers to 30 micrometers, which can cover all bandwidth ranges of the ultrasonic transducer.
In some embodiments, the soft material 50 is an epoxy.
The epoxy resin is a kind ofThe molecular formula is (C11H 12O 3) n, which means that the molecule contains more than two +.>The generic name of a group of polymers. The epoxy resin has the following characteristics:
1．excellent, especially alkali resistance.
2. Paint filmStrong, especially for metals.
3. Has better heat resistance and electric insulation property.
4. Paint film protectionPreferably.
Thus, the use of epoxy facilitates the connection of the piezoelectric layer 20 and the first and second metal conductive layers 30 and 10 without the need for additional adhesive. Furthermore, the operating environment of the ultrasonic transducer requires that the soft material 50 must be insulating and heat resistant, with epoxy resin meeting just all of the above.
In some particular embodiments, the bottom plate 40 has a back cavity 410.
The base plate 40 of the ultrasonic transducer is mainly in two forms, one is of the back cavity 410 type and the other is of the cavity type. The back cavity 410 type ultrasonic transducer refers to a recess formed on the side of the bottom plate 40 facing away from the piezoelectric layer 20, and mainly aims to provide vibration air to generate ultrasonic waves. The hollow ultrasonic transducer refers to a structure in which the middle of the bottom plate 40 is hollowed out like a drum, and the purpose of the hollow ultrasonic transducer is to better move air to generate ultrasonic waves. Because the fabrication process of the cavity type ultrasonic transducer is complex, it is difficult to ensure that the cavity inside the transducer is consistent, and thus the present invention chooses to process the bottom plate 40 into the back cavity 410 type.
In some specific embodiments, the bottom plate 40 is a silicon plate.
Silicon plates are one material commonly used in electronic products. The base plate 40 of the present invention may be replaced with other materials, such as ceramic materials, etc., but none of these are as inexpensive and durable as silicon plates. In addition, the material of the liner 80 may be a silicon plate, a ceramic material, or other materials. The silicon plate material is preferred here because the silicon plate is easy to grind and facilitates subsequent processing. The silicon nitride semiconductor material can be low-resistance monocrystalline silicon, high-resistance monocrystalline silicon, low-resistance polycrystalline silicon or high-resistance polycrystalline silicon.
Finally, the acoustic impedance isThe term, refer to->At->Pressure over an area and +.>Complex number of (2)Ratio of the two. The unit is->. When consider->Rather than distributed impedance, the impedance of a part of the material is the complex +.>. Acoustic impedance ofOften called "acoustic resistance", which is->Called "/">". Resistance to displacement of the medium during mechanical wave conduction needs to be overcome. Volume velocity is the medium flow velocity through an area,/->The larger the force required to push the media, the larger the impedance and the smaller the force required.
Piezoelectric ceramics, which are information function ceramic materials capable of mutually converting mechanical energy and electric energy-piezoelectric effects, have dielectric properties, elasticity, etc., in addition to piezoelectricity, and have been widely used in medical imaging, acoustic sensors, acoustic transducers, ultrasonic motors, etc. The piezoelectric ceramic is manufactured by using the piezoelectric effect which is the bound electric charges with opposite signs on the surfaces of two ends of the material and is sensitive because the material is polarized by causing the relative displacement of the positive and negative electric charge centers inside the material under the action of mechanical stress.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (10)

1. A process for manufacturing an ultrasonic transducer, comprising:
step S1, rolling a piezoelectric ceramic raw material into a viscous polymerization state;
s2, coating a viscous aggregation state piezoelectric ceramic raw material on the surface of a lining plate by a centrifugal spin coating method to form a piezoelectric layer;
step S3, a die with holes arranged in an array is molded on the piezoelectric layer to enable the piezoelectric layer to be provided with a plurality of piezoelectric columns arranged in an array, and then the die is removed;
s4, placing the lining plate and the molded piezoelectric layer in a vacuum environment, and sintering at high temperature to form piezoelectric ceramics;
step S5: preparing a bottom plate plated with a first metal conductive layer, and connecting one end of the piezoelectric column to the first metal conductive layer;
step S6: polishing one surface of the piezoelectric ceramic, which faces away from the first metal conducting layer, until the piezoelectric column is exposed;
step S7: and a layer of second conductive metal is arranged at one end of the piezoelectric column, which is far away from the first metal conductive layer.
2. The method according to claim 1, wherein the step 4 further comprises filling soft material, the soft material is melted by heating and then filled in the gaps between the piezoelectric columns, and the air bubbles in the soft material are removed by vacuumizing, and the soft material is cooled and shaped and then the redundant soft material is ground until the piezoelectric columns are exposed.
3. An ultrasonic transducer comprising an ultrasonic transducer manufactured by the process manufacturing method of the ultrasonic transducer according to claim 1 or 2, characterized in that a second metal conductive layer, a piezoelectric layer, a first metal conductive layer and a bottom plate are sequentially provided from top to bottom, and the piezoelectric layer comprises the piezoelectric columns arranged in an array.
4. The ultrasonic transducer of claim 3, wherein the second metallic conductive layer covers only a portion of the piezoelectric pillars.
5. An ultrasonic transducer according to claim 3, wherein the piezoelectric ceramic raw material is a lead zirconate titanate mixture.
6. The ultrasonic transducer of claim 3, wherein the first and second metallic conductive layers are made of aluminum.
7. The ultrasonic transducer of claim 3, wherein the piezoelectric pillars have a height of 3 microns to 30 microns.
8. The ultrasonic transducer of claim 3, wherein the soft material is an epoxy.
9. The ultrasonic transducer of claim 3, wherein the base plate has a back cavity.
10. The ultrasonic transducer of claim 3, wherein the base plate is a silicon plate.
CN202311539792.5A 2023-11-18 2023-11-18 Technological manufacturing method of ultrasonic transducer and ultrasonic transducer Pending CN117545338A (en)

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CN202311539792.5A CN117545338A (en) 2023-11-18 2023-11-18 Technological manufacturing method of ultrasonic transducer and ultrasonic transducer

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Application Number Priority Date Filing Date Title
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CN117545338A true CN117545338A (en) 2024-02-09

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