阅读说明：本技术 一维线阵压电元件的制备方法、二维面阵超声换能器 (Preparation method of one-dimensional linear array piezoelectric element and two-dimensional area array ultrasonic transducer ) 是由 郑海荣 马腾 李永川 靳遥 郭瑞彪 黄继卿 苏敏 严飞 于 2018-07-05 设计创作，主要内容包括：本发明公开了一种一维线阵压电元件的制备方法、二维面阵超声换能器。由于经过切割第一压电片和第二压电片,制备的压电元件的每个压电阵元都在横向振动模式共振频率工作,并且为双层并联结构,使得电阻抗大大降低,使得压电阵元的阻抗不匹配的问题减弱,有效降低阻抗不匹配产生的不利影响,提高换能器能量转换效率,甚至可以不进行阻抗匹配,从而简化换能器制作过程,降低制作成本。此外,通过对第一压电片和第二压电片进行切割,及利用非导电材料及去耦合材料填充,使得制备得到的一维线阵压电元件的每个压电阵元的相反的两个侧面分别为正电极及负电极,能够进一步的解决电极引出的问题,构造过程相对简单,实用性高且成本低。(The invention discloses a preparation method of a one-dimensional linear array piezoelectric element and a two-dimensional area array ultrasonic transducer. Because through cutting first piezoelectric patch and second piezoelectric patch, every piezoelectric array element of the piezoelectric element of preparation all works at transverse vibration mode resonant frequency to for double-deck parallel structure, make electrical impedance greatly reduced, make the unmatched problem of impedance of piezoelectric array element weaken, effectively reduce the adverse effect that the impedance mismatch produced, improve transducer energy conversion efficiency, can not carry out impedance matching even, thereby simplify transducer manufacture process, reduce the cost of manufacture. In addition, the first piezoelectric sheet and the second piezoelectric sheet are cut and filled with the non-conductive material and the decoupling material, so that two opposite side surfaces of each piezoelectric array element of the prepared one-dimensional linear array piezoelectric element are respectively a positive electrode and a negative electrode, the problem of electrode extraction can be further solved, the construction process is relatively simple, the practicability is high, and the cost is low.)

1. A method for manufacturing a one-dimensional linear array piezoelectric element is characterized by comprising the following steps:

respectively bonding a first piezoelectric sheet and a second piezoelectric sheet to two opposite surfaces of the bonding layer, wherein electrodes are already laid on the bonding surfaces of the first piezoelectric sheet and the second piezoelectric sheet and two side surfaces corresponding to the long edges of the bonding surfaces;

cutting the large surface of the first piezoelectric sheet according to a first cutting direction and a first cutting depth to obtain a first cutting seam; the first cutting direction is parallel to the long side of the large surface, and the first cutting depth is greater than the thickness of the first piezoelectric sheet and less than the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet;

filling the first kerf with a non-conductive material;

cutting the large surface of the first piezoelectric sheet according to a second cutting direction, a second cutting depth and a cutting interval to obtain a plurality of second cutting seams with equal intervals; the second cutting direction is parallel to the short side of the large surface, and the second cutting depth is at least the preset target thickness of the one-dimensional linear array piezoelectric element and is smaller than the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet;

pouring decoupling materials into the second cutting seams, grinding the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet after the decoupling materials are solidified until the thickness of the first piezoelectric sheet is the same as that of the second piezoelectric sheet, and the sum of the thicknesses is equal to the target thickness;

laying electrodes on the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet, cutting the decoupling material on the large surface of the first piezoelectric sheet to form a first electrode isolation groove, cutting the large surface of the first piezoelectric sheet in a direction parallel to the first cutting line to obtain a second electrode isolation groove, wherein the second electrode isolation groove is positioned at the edge of the large surface of the first piezoelectric sheet, and cutting a third electrode isolation groove symmetrical to the second electrode isolation groove on the large surface of the second piezoelectric sheet to obtain the one-dimensional linear array piezoelectric element comprising a plurality of piezoelectric array elements separated by the decoupling material; and two opposite side surfaces of each piezoelectric array element are respectively a positive electrode and a negative electrode.

2. The method of claim 1, wherein the decoupling material is an epoxy resin.

3. A production method according to claim 1, wherein a thickness of the first piezoelectric sheet is smaller than a thickness of the second piezoelectric sheet.

4. The production method according to claim 1, wherein the first piezoelectric sheet or the second piezoelectric sheet is any one of a piezoelectric ceramic, a single crystal material, and a composite material produced from a piezoelectric material or a single crystal material and a polymer material.

5. A two-dimensional area array ultrasonic transducer, comprising a two-dimensional area array piezoelectric element, wherein the two-dimensional area array piezoelectric element comprises: a plurality of decoupling layers, and a plurality of one-dimensional linear array piezoelectric elements prepared by the method for preparing one-dimensional linear array piezoelectric elements according to any one of claims 1 to 4;

the one-dimensional linear array piezoelectric elements are arranged at preset intervals, and the interval between every two adjacent one-dimensional linear array piezoelectric elements is filled with the decoupling layer;

the positive electrodes of a plurality of one-dimensional linear array piezoelectric elements are positioned on the same surface, and the negative electrodes are positioned on the same surface.

6. The two-dimensional area array ultrasonic transducer according to claim 5, further comprising: the circuit board and the conducting layer are formed by connecting the edges of the first flexible circuit board and the second flexible circuit board and have preset included angles;

the outer surface of the first flexible circuit board is arranged on a positive electrode of the two-dimensional area array piezoelectric element, and the conducting layer covers a negative electrode of the two-dimensional area array piezoelectric element to obtain a two-dimensional area array ultrasonic transducer main body;

the through hole on the second flexible circuit board is connected with a cable, and the conducting layer is connected with the ground pole.

7. The two-dimensional area array ultrasonic transducer according to claim 6, wherein through holes are formed in the first flexible circuit board and the second flexible circuit board, the through holes in the first flexible circuit board correspond to the through holes in the second flexible circuit board one by one, and the through holes in the first flexible circuit board are matched with the positive electrodes of the piezoelectric array elements in the two-dimensional area array piezoelectric elements.

8. The two-dimensional area array ultrasonic transducer according to claim 6, further comprising a housing and a top plate with an uncovered top;

the two-dimensional area array ultrasonic transducer main body is arranged in the shell, and a conducting layer of the two-dimensional area array ultrasonic transducer main body and the bottom surface of the shell are positioned on the same plane;

the top plate is mounted on top of the housing.

9. The two-dimensional area array ultrasonic transducer according to claim 8, wherein a through hole is provided on the top plate, the two-dimensional area array ultrasonic transducer further comprises a guide tube, one end of the guide tube is connected with the through hole on the top plate in a matching manner, and the cable passes through the guide tube and is connected with the outside.

10. The two-dimensional area array ultrasonic transducer according to claim 6, wherein the conductive layer is a gold plating layer coated on a surface on which a negative electrode of the two-dimensional area array piezoelectric element is located.

Technical Field

The invention relates to the field of medical instrument preparation, in particular to a preparation method of a one-dimensional linear array piezoelectric element and a two-dimensional area array ultrasonic transducer.

Background

The ultrasonic phase control technology is a technology that a plurality of piezoelectric wafers are distributed and arranged according to a certain rule, then each array element is excited by sequentially presetting delay time, the phase relation of sound waves reaching (or coming from) a certain point in an object is changed, and the change of a focus and the direction of a sound beam is realized, so that the scanning, the deflection and the focusing of the sound beam of ultrasonic waves are realized. If the deflection and the focusing of the acoustic beam are dynamically controlled by an electronic system and the ultrasonic acoustic beam is accurately controlled without generating grating lobes, the distance between adjacent array elements of the transducer needs to be ensured not to exceed one half of the wavelength of the acoustic wave in the medium.

At present, most medical phased array ultrasonic transducers are constructed in a longitudinal vibration mode, along with the improvement of working frequency and the increase of scale, the size of a single array element of the transducer is reduced, and the electrical connection between the array elements is more complicated while the electrical impedance is increased. And the increase in impedance of the array element causes an impedance mismatch between the array element and the rf signal source. The consequences of this mismatch are: for diagnostic ultrasound arrays, impedance mismatch results in lower acoustic energy output at the output, reduced image resolution at the receiving end, and poor signal-to-noise ratio, and for high power therapeutic ultrasound arrays, impedance mismatch results in too low electrical-to-acoustic conversion efficiency. At present, in order to solve the problem of impedance mismatch, a commonly used solution is to perform electrical impedance matching on each array element of the phased array ultrasonic transducer, however, performing electrical impedance matching on each array element has the problems of high matching cost, long consumed time, poor practicability and the like.

Disclosure of Invention

The invention mainly aims to provide a preparation method of a one-dimensional linear array piezoelectric element and a two-dimensional area array ultrasonic transducer, aiming at solving the technical problems of high matching cost, long consumed time and poor practical performance existing in the prior art when each array element is subjected to impedance matching.

The invention provides a preparation method of a one-dimensional linear array piezoelectric element, which comprises the following steps:

respectively bonding a first piezoelectric sheet and a second piezoelectric sheet to two opposite surfaces of the bonding layer, wherein electrodes are already laid on the bonding surfaces of the first piezoelectric sheet and the second piezoelectric sheet and two side surfaces corresponding to the long edges of the bonding surfaces;

cutting the large surface of the first piezoelectric sheet according to a first cutting direction and a first cutting depth to obtain a first cutting seam; the first cutting direction is parallel to the long side of the large surface, and the first cutting depth is greater than the thickness of the first piezoelectric sheet and less than the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet;

filling the first kerf with a non-conductive material;

cutting the large surface of the first piezoelectric sheet according to a second cutting direction, a second cutting depth and a cutting interval to obtain a plurality of second cutting seams with equal intervals; the second cutting direction is parallel to the short side of the large surface, and the second cutting depth is at least the preset target thickness of the one-dimensional linear array piezoelectric element and is smaller than the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet;

pouring decoupling materials into the second cutting seams, grinding the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet after the decoupling materials are solidified until the thickness of the first piezoelectric sheet is the same as that of the second piezoelectric sheet, and the sum of the thicknesses is equal to the target thickness;

laying electrodes on the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet, cutting the decoupling material on the large surface of the first piezoelectric sheet to form a first electrode isolation groove, cutting the large surface of the first piezoelectric sheet in a direction parallel to the first cutting line to obtain a second electrode isolation groove, wherein the second electrode isolation groove is positioned at the edge of the large surface of the first piezoelectric sheet, and cutting a third electrode isolation groove symmetrical to the second electrode isolation groove on the large surface of the second piezoelectric sheet to obtain the one-dimensional linear array piezoelectric element comprising a plurality of piezoelectric array elements separated by the decoupling material; and two opposite side surfaces of each piezoelectric array element are respectively a positive electrode and a negative electrode.

The invention also provides a two-dimensional area array ultrasonic transducer, which comprises a two-dimensional area array piezoelectric element, wherein the two-dimensional area array piezoelectric element comprises a plurality of decoupling layers and a plurality of one-dimensional linear array piezoelectric elements prepared by the preparation method of the one-dimensional linear array piezoelectric element;

the one-dimensional linear array piezoelectric elements are arranged at preset intervals, and the interval between every two adjacent one-dimensional linear array piezoelectric elements is filled with the decoupling layer;

the positive electrodes of a plurality of one-dimensional linear array piezoelectric elements are positioned on the same surface, and the negative electrodes are positioned on the same surface.

According to the technical scheme of the invention, each piezoelectric array element of the prepared piezoelectric element works at the transverse vibration mode resonant frequency by cutting the first piezoelectric sheet and the second piezoelectric sheet, and is of a double-layer parallel structure, so that the electrical impedance is greatly reduced, the problem of impedance mismatching of the piezoelectric array elements is weakened, the adverse effect generated by impedance mismatching is effectively reduced, the energy conversion efficiency of the transducer is improved, even the impedance matching is not carried out, the manufacturing process of the transducer is simplified, and the manufacturing cost is reduced. In addition, the first piezoelectric sheet and the second piezoelectric sheet are cut and filled with the non-conductive material and the decoupling material, so that two opposite side surfaces of each piezoelectric array element of the prepared one-dimensional linear array piezoelectric element are respectively a positive electrode and a negative electrode, the problem of electrode extraction can be further solved, the construction process is relatively simple, the practicability is high, and the cost is low.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flow chart of a method for manufacturing a one-dimensional linear array piezoelectric element according to an embodiment of the present invention;

fig. 2a to fig. 2g are structural change diagrams in the process of manufacturing a one-dimensional linear array piezoelectric element in the embodiment of the present invention;

fig. 3 is a schematic diagram of a one-dimensional linear array piezoelectric element after being disassembled according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an ultrasonic transducer in an embodiment of the invention;

FIG. 5 is a schematic diagram of a two-dimensional area array piezoelectric device according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an arrangement of two-dimensional area array piezoelectric elements according to an embodiment of the present invention;

fig. 7 is an external schematic view of a two-dimensional area array ultrasonic transducer according to an embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a schematic flow chart of a method for manufacturing a one-dimensional linear array piezoelectric element according to an embodiment of the present invention is shown, where the method includes the following process steps 101-106, and specifically includes:

step 101, respectively bonding a first piezoelectric sheet and a second piezoelectric sheet to two opposite surfaces of an adhesive layer;

in the embodiment of the present invention, two piezoelectric sheets, namely, a first piezoelectric sheet and a second piezoelectric sheet, need to be prepared for preparing a one-dimensional linear array piezoelectric element, where the materials of the first piezoelectric sheet and the second piezoelectric sheet may be the same or different, and the first piezoelectric sheet or the second piezoelectric sheet may be any one of piezoelectric ceramics, single crystal materials, and composite materials prepared from piezoelectric materials or single crystal materials and polymer materials. The piezoelectric ceramic may be specifically a lead-free piezoelectric ceramic.

The first piezoelectric sheet and the second piezoelectric sheet are specifically piezoelectric sheets of cuboid structures, the large faces refer to faces with the largest area in the cuboid structures, one cuboid structure is provided with two large faces and four side faces, the two large faces are two opposite faces in the cuboid structures, and the two large faces can also be front faces and back faces. It will be appreciated that the first piezoelectric sheet and the second piezoelectric sheet are selected to be of a very typical rectangular parallelepiped structure, since the linear array piezoelectric element is assumed to have a plurality of groups of piezoelectric array elements.

The electrodes are laid on the bonding surfaces of the first piezoelectric sheet and the second piezoelectric sheet and on two side surfaces corresponding to the long edges of the bonding surfaces, and it should be noted that, in practical applications, when the electrodes are laid on the first piezoelectric sheet and the second piezoelectric sheet, for convenience, the electrodes are laid in a manner that four side surfaces of the first piezoelectric sheet and the second piezoelectric sheet are sputtered, however, what actually acts as the electrodes is the two side surfaces corresponding to the long edges of the bonding surfaces, and if the electrodes are laid on the side surfaces corresponding to the short edges, the electrodes need to be removed in a subsequent process. As shown in fig. 2(a), a first piezoelectric sheet and a second piezoelectric sheet, wherein the piezoelectric sheet with small thickness is used as the first piezoelectric sheet, the piezoelectric sheet with large thickness is used as the second piezoelectric sheet, wherein the hatched portion indicates that the electrodes are laid, all the surfaces of the first piezoelectric sheet are laid with the electrodes, and the other four surfaces of the second piezoelectric sheet except for two side surfaces corresponding to the short side are laid with the electrodes. In addition, the electrodes on the first piezoelectric sheet and the second piezoelectric sheet can be laid by conductive adhesive or metal plating with good conductivity.

The bonding surface of the first piezoelectric sheet and the bonding surface of the second piezoelectric sheet are large surfaces bonded with the bonding layer and provided with electrodes, as shown in fig. 2b, the bonding layer is arranged between the first piezoelectric sheet and the second piezoelectric sheet, and the first piezoelectric sheet, the bonding layer and the second piezoelectric sheet are bonded together according to fig. 2b to obtain a structure shown in fig. 2 c.

As can be seen from fig. 2c, the first piezoelectric sheet, the adhesive layer, and the second piezoelectric sheet are sequentially stacked, and the area of the large surface of the first piezoelectric sheet is the same as the area of the large surface of the adhesive layer, the area of the large surface of the second piezoelectric sheet is the same as the area of the large surface of the adhesive layer, and the areas of the first piezoelectric sheet and the second piezoelectric sheet in contact with the adhesive layer are overlapped. Namely, the areas of the large surfaces of the first piezoelectric sheet, the adhesive layer and the second piezoelectric sheet are the same.

Wherein, the adhesive layer can be prepared by adhesive glue, and fig. 2b can be the explosion diagram of fig. 2c, and in the actual preparation process, the following steps can be performed: and uniformly coating adhesive glue with preset thickness on one large surface of the first piezoelectric sheet, superposing the surface coated with the adhesive glue of the first piezoelectric sheet and one large surface of the second piezoelectric sheet, and after the adhesive glue is solidified, obtaining the first piezoelectric sheet, the adhesive layer and the second piezoelectric sheet which are arranged in an overlapped mode.

102, cutting the large surface of the first piezoelectric sheet according to a first cutting direction and a first cutting depth to obtain a first cutting seam;

in the embodiment of the present invention, the first cut is obtained by cutting the large surface of the first piezoelectric sheet in the first cutting direction and the first cutting depth, and it is understood that the large surface of the first piezoelectric sheet is not the large surface to which the adhesive layer is bonded but the other large surface opposite to the large surface to which the adhesive layer is bonded. And cutting downwards from the large surface of the first piezoelectric sheet, wherein the first cutting direction is parallel to the long edge of the large surface, the cutting position is the edge of the long edge on one side of the large surface, the first cutting depth is greater than the thickness of the first piezoelectric sheet and less than the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet, namely, when the first piezoelectric sheet is cut downwards from the large surface of the first piezoelectric sheet, the first cutting seam is obtained by cutting through the first piezoelectric sheet but not cutting through the second piezoelectric sheet.

103, filling the first cutting seams with a non-conductive material;

104, cutting the large surface of the first piezoelectric sheet according to a second cutting direction, a second cutting depth and a cutting interval to obtain a plurality of second cutting seams with equal intervals;

in the embodiment of the invention, after the first slit is obtained by cutting, the first slit is filled with the non-conductive material, and after the filling is finished, the large surface of the first piezoelectric sheet is continuously cut according to the second cutting direction, the second cutting depth and the cutting interval, so as to obtain a plurality of second slits with equal intervals.

The second cutting direction is parallel to the short side of the large surface of the first piezoelectric sheet, namely the first cutting direction and the second cutting direction are perpendicular to each other.

The second cutting depth is at least a preset target thickness, the target thickness refers to the thickness of the finally formed one-dimensional linear array piezoelectric element, and the second cutting depth is smaller than the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet.

105, pouring a decoupling material into the second kerf, and grinding the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet after the decoupling material is solidified until the thickness of the first piezoelectric sheet is the same as that of the second piezoelectric sheet and the sum of the thicknesses is equal to the target thickness;

in the embodiment of the invention, after a plurality of second cutting slits with equal intervals are obtained by cutting, decoupling materials are poured into the second cutting slits, after the decoupling materials are solidified, the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet are ground until the thickness of the first piezoelectric sheet is the same as that of the second piezoelectric sheet, and the sum of the thickness of the first piezoelectric sheet and the thickness of the second piezoelectric sheet is equal to the target thickness.

It should be noted that, during polishing, the second piezoelectric sheet needs to be polished to the extent that the decoupling material reaches the surface.

It should be noted that, in practical application, the sequence of cutting and filling the material of the first slit and the second slit is not limited, except for the manner of cutting first to obtain the first slit, then filling the first slit, then cutting to obtain the second slit, and pouring the decoupling material into the second slit, the second slit may be obtained by cutting first, and the decoupling material is poured into the second slit, then cutting to obtain the first slit, and filling the first slit. Or, the first cutting slit and the second cutting slit can be obtained by cutting, and then the non-conductive material is filled into the first cutting slit and the decoupling material is poured into the second cutting slit respectively. Therefore, in practical applications, the cutting sequence of the first cutting slit and the second cutting slit, and the filling time and sequence of the non-conductive material and the decoupling material can be set according to specific needs, and are not limited herein.

Referring to fig. 2d, in order to obtain a schematic diagram of the first slit and the second slit after the cutting, it should be noted that fig. 2d includes two different viewing angles. The first kerf and the second kerf are filled, a non-conductive material is filled in the first kerf, and a decoupling material is filled in the second kerf, it should be noted that the type of the material filled in the area where the first kerf and the second kerf are overlapped is not limited, and the material may be a non-conductive material, a decoupling material, or a mixed material of a non-conductive material and a decoupling material, which is not limited herein. Fig. 2e is a schematic diagram illustrating the first kerf and the second kerf being filled and the two large faces being polished according to the embodiment of the invention.

Step 106, laying electrodes on the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet, cutting the decoupling material on the large surface of the first piezoelectric sheet to form a first electrode isolation groove, cutting the large surface of the first piezoelectric sheet in a direction parallel to the first cutting seam to obtain a second electrode isolation groove, wherein the second electrode isolation groove is located at the edge of the large surface of the first piezoelectric sheet, and cutting a third electrode isolation groove symmetrical to the second electrode isolation groove on the large surface of the second piezoelectric sheet;

in the embodiment of the present invention, after the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet are polished, electrodes are laid on the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet, and after the electrodes are laid, the electrode isolation grooves are cut. Referring to fig. 2f, the large surfaces of the first piezoelectric sheet and the second piezoelectric sheet are covered with electrodes, and in particular, in fig. 2f, the shaded portions indicate the covered electrodes.

Referring to fig. 2g, a second electrode isolation groove 6 is formed on the large surface of the first piezoelectric sheet by cutting in a direction parallel to the first cutting line, the second electrode isolation groove 6 is located at the edge of the large surface of the first piezoelectric sheet, and a third electrode isolation groove 7 symmetrical to the second electrode isolation groove 6 is formed on the large surface of the second piezoelectric sheet by cutting. Wherein, decoupling material forms multiple decoupling layers after being poured, the surface of each decoupling layer is cut on the large surface of the first piezoelectric sheet so as to form the first electrode isolation groove 5, and a one-dimensional linear array piezoelectric element comprising a plurality of piezoelectric array elements separated by decoupling material is obtained, and two opposite side surfaces of each piezoelectric array element are respectively a positive electrode and a negative electrode, and each piezoelectric array element is separated by decoupling material, therefore, the positive electrode and the negative electrode of each piezoelectric array element can be individually led without mutual interference, please refer to fig. 2g, which is a schematic diagram of the one-dimensional linear array piezoelectric element in the embodiment of the present invention. The first electrode isolation groove 5, the second electrode isolation groove 6, and the third electrode isolation groove 7 are provided to isolate the electrode, and therefore, it is usually necessary to ensure that the electrode can be isolated during cutting, and the cutting depth is shallow and much smaller than the cutting depth of the first cut and the second cut. In fig. 2g, 4 denotes a non-conductive layer made of a non-conductive material filled in the first slit.

Further, please refer to fig. 3, which is an explosion diagram of a one-dimensional linear array piezoelectric element according to an embodiment of the present invention.

In the figure, the upper layer is the piezoelectric vibrator cut by the first piezoelectric element, the lower layer is the piezoelectric vibrator cut by the second piezoelectric element, the upper piezoelectric vibrator and the lower piezoelectric vibrator form a piezoelectric array element, the S1 surface and the S4 surface are two opposite side surfaces of the one-dimensional linear array piezoelectric element, one of the two opposite side surfaces is a positive electrode, and the other one is a negative electrode.

In fig. 3, the inner surfaces S2 of the one-dimensional linear piezoelectric elements communicate with the side surface S1, and the inner surfaces S2 are disconnected from the other side surface S4 by embedding the non-conductive filling material, so that the side surface S1 can be used as one electrode terminal, and similarly, the outer surfaces S3 of the one-dimensional linear piezoelectric elements are disconnected from the side surface S1 by the second electrode isolation grooves 6 and the third electrode isolation grooves 7, but are electrically connected to the side surface S4, so that the side surface S4 can be used as the other electrode terminal. For example, the surface S1 is used as a lead-out surface of a positive electrode, the surface S4 is used as a lead-out surface of a negative electrode, and the surface S4 may be a radiation surface.

The first electrode isolation groove is used for dividing electrodes among the piezoelectric array elements, so that the piezoelectric array elements are mutually independent.

In fig. 3, 2 denotes an adhesive layer, 1 denotes a piezoelectric sheet, and the upper piezoelectric sheet is a first piezoelectric sheet, the lower piezoelectric sheet is a second piezoelectric sheet, 3 denotes a decoupling layer formed of a filled decoupling material, 4 denotes a non-conductive layer formed of a filled non-conductive material, 5 denotes a first electrode isolation groove cut and formed in the decoupling layer 3, 6 denotes a second electrode isolation groove, and 7 denotes a third electrode isolation groove.

In the embodiment of the invention, each piezoelectric array element of the prepared piezoelectric element works at the resonant frequency of the transverse vibration mode by cutting the first piezoelectric sheet and the second piezoelectric sheet and is of a double-layer parallel structure, so that the electrical impedance is greatly reduced, the problem of impedance mismatching of the piezoelectric array elements is weakened, the adverse effect generated by impedance mismatching is effectively reduced, even the impedance matching is not carried out, the manufacturing process of the transducer is simplified, and the manufacturing cost is reduced. In addition, the first piezoelectric sheet and the second piezoelectric sheet are cut and filled with the non-conductive material and the decoupling material, so that two opposite side surfaces of each piezoelectric array element of the prepared one-dimensional linear array piezoelectric element are respectively a positive electrode and a negative electrode, the problem of electrode extraction can be further solved, the construction process is relatively simple, the practicability is high, and the cost is low.

Referring to fig. 4, a schematic structural diagram of an area array ultrasonic transducer according to an embodiment of the present invention includes: referring to fig. 5, a two-dimensional area array piezoelectric device is shown, which includes: a plurality of decoupling layers and a plurality of one-dimensional linear array piezoelectric elements prepared by the preparation method of the one-dimensional linear array piezoelectric element shown in figure 1;

the piezoelectric elements of the linear arrays are arranged at preset intervals, and the interval between two adjacent linear array piezoelectric elements is filled by a decoupling layer;

the positive electrodes of the plurality of one-dimensional linear array piezoelectric elements are positioned on the same surface, and the negative electrodes of the plurality of one-dimensional linear array piezoelectric elements are positioned on the same surface. As shown in fig. 6, a schematic diagram of a two-dimensional area array piezoelectric element arrangement is shown.

Referring to fig. 4, the two-dimensional area array ultrasonic transducer further includes: a circuit board (i.e., the flexible circuit board (signal source) in fig. 4) having a preset included angle formed by connecting edges of the first flexible circuit board and the second flexible circuit board, and a conductive layer (i.e., the gold-plated layer (ground) in fig. 4); wherein, the preset included angle can be any one angle between 60 degrees and 120 degrees, and is preferably 90 degrees. It is to be understood that in fig. 4, the left-hand drawing is a part of the right-hand drawing.

The outer surface of the first flexible circuit board is provided with a positive electrode of the two-dimensional area array piezoelectric element, and the conducting layer covers a negative electrode of the two-dimensional area array piezoelectric element to obtain a two-dimensional area array ultrasonic transducer main body;

the through hole on the second flexible circuit board is connected with the cable, and the conducting layer is connected with the ground pole.

The two-dimensional array piezoelectric element comprises a two-dimensional array piezoelectric element, a first flexible circuit board and a second flexible circuit board, wherein through holes are formed in the first flexible circuit board and the second flexible circuit board, the through holes in the first flexible circuit board correspond to the through holes in the second flexible circuit board one to one, and the through holes in the first flexible circuit board are matched with positive electrodes of the piezoelectric array elements in the two-dimensional array piezoelectric element.

Referring to fig. 4, the two-dimensional area array ultrasonic transducer further includes a housing with an uncovered top and a top plate;

the two-dimensional area array ultrasonic transducer main body is arranged in the shell, and a conducting layer of the two-dimensional area array ultrasonic transducer main body and the bottom surface of the shell are positioned on the same plane; the top plate is mounted on top of the housing.

Wherein, set up the through-hole on the roof, two-dimensional area array ultrasonic transducer still includes the guiding tube, the one end of guiding tube and the through-hole accordant connection on the roof, and the cable passes guiding tube and external connection. Fig. 7 is an external schematic view of a two-dimensional area array ultrasonic transducer according to an embodiment of the present invention.

Preferably, the conductive layer is a gold plating layer coated on a surface where the negative electrode of the two-dimensional area array piezoelectric element is located.

It will be appreciated that if a one-dimensional linear array piezoelectric element is used comprising M piezoelectric array elements and N are used as linear array piezoelectric elements, then an M x N two-dimensional area array piezoelectric element will be formed.

In the embodiment of the invention, the internal electrodes of the double-layer structure of the piezoelectric element are led out by the wrapped electrode, the electrodes are led out more conveniently by matching with the flexible circuit board, and the two-dimensional area array piezoelectric element can be formed by splicing N one-dimensional linear array piezoelectric array elements with M piezoelectric array elements, the size of the one-dimensional linear array piezoelectric element can be accurately controlled, so that an M x N area array with good consistency can be obtained, and the number of the array elements and the scale of the transducer can be flexibly controlled.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In view of the above description of the method for manufacturing a one-dimensional linear array piezoelectric element and the two-dimensional area array ultrasonic transducer provided by the present invention, those skilled in the art will appreciate that the concepts according to the embodiments of the present invention may be modified in the specific implementation manners and the application ranges.