KR102030932B1 - Piezoelectric transducer, piezoelectric transducer array and method of fabricating thereof - Google Patents

Abstract

The present invention relates to a piezoelectric transducer, an array of the piezoelectric transducer, and a manufacturing method of the piezoelectric transducer array. According to one embodiment of the present invention, the piezoelectric transducer comprises: a metal plate (10) having a first electrode formed thereon; a piezoelectric ceramic layer (30) disposed to be in contact with the first electrode; a polymer film (40) having a second electrode, disposed on a lower surface of the piezoelectric ceramic layer, formed thereon; and a substrate (50) disposed on a lower part of the polymer film. The piezoelectric transducer of the present invention can be used for energy harvesting and can also be used as a speaker.

Description

Piezoelectric transducers, arrays thereof and methods of making them {PIEZOELECTRIC TRANSDUCER, PIEZOELECTRIC TRANSDUCER ARRAY AND METHOD OF FABRICATING THEREOF}

The present invention relates to piezoelectric transducers and arrays of such piezoelectric transducers, and also to methods of making such piezoelectric transducer arrays.

In general, piezoelectric transducers are energy conversion devices having a piezoelectric function that converts mechanical energy such as pressure, vibration, and force into electrical energy or electrical energy into mechanical energy such as pressure, vibration, and force. It is widely used in piezoelectric energy harvesters, piezoelectric ultrasonic transducers, directional piezoelectric speakers, and ultra-precision piezoelectric actuators.

In addition, the piezoelectric transducer converts an electrical signal into an ultrasonic wave by using a resonance phenomenon of the piezoelectric material, and transmits and receives an ultrasonic wave by converting the ultrasonic wave into an electrical signal.

Conventional representative transducers use the piezoelectric properties of the polymer material PVDF to connect the electrodes to a piezoelectric thin film processed PVDF in the form of a film and apply a signal according to the sound to generate a sound by vibrating the piezoelectric thin film.

In the manufacture of piezoelectric transducers, individual piezoelectric transducer elements are generally manufactured and used, but such piezoelectric transducer elements may be arranged in an array. In the fabrication of such an array, it is common to fabricate the piezoelectric transducer elements, which are manufactured in parallel, on a substrate. However, when fabricating such an array, there is a problem in that wiring is difficult and efficient step by step manufacturing is difficult. Therefore, there is a problem that mass production of the piezoelectric transducer array structure is difficult.

The present invention seeks to provide a piezoelectric transducer array that can be mass produced in the manufacture of piezoelectric transducer arrays, and also to a method for mass production of such piezoelectric transducer arrays.

Method of manufacturing a piezoelectric transducer according to an embodiment of the present invention, preparing a metal plate having a first electrode formed on one surface; Preparing a piezoelectric ceramic layer; Attaching a piezoelectric ceramic layer so that the first electrode abuts on one surface of the piezoelectric ceramic layer; Preparing a polymer film having a second electrode pattern formed on one surface thereof; Attaching a polymer film to the other surface of the piezoelectric ceramic layer to be in contact with the second electrode; And preparing a substrate, and attaching the substrate and the piezoelectric ceramic layer to each other using an elastic body.

The elastic body is in contact with the substrate and the piezoelectric ceramic layer, and the polymer film is spaced apart from the substrate.

Both surfaces of the piezoelectric ceramic layer are coated with a metal.

The metal plate is in the form of a horn.

According to a further embodiment of the present invention, a method of manufacturing a piezoelectric transducer may include preparing n × m metal plates having a first electrode formed on one surface thereof; preparing n x m piezoelectric ceramic layers; Attaching a piezoelectric ceramic layer so that the first electrode abuts on one surface of the piezoelectric ceramic layer; Preparing n x m polymer films having a second electrode pattern formed on one surface thereof; Attaching the polymer film to the second surface of the piezoelectric ceramic layer to be in contact with the second electrode; And preparing a substrate, and attaching the substrate and the piezoelectric ceramic layer to each other using an elastic body, wherein n and m are integers of 1 or more.

The elastic body is in contact with the substrate and the piezoelectric ceramic layer, and the polymer film is spaced apart from the substrate.

A second electrode pattern is formed on the polymer film in advance so that the second electrodes are in electrical communication with each other.

According to an embodiment of the present invention, a piezoelectric transducer includes: a metal plate having a first electrode disposed on a bottom surface thereof; A piezoelectric ceramic layer disposed to contact the first electrode; A polymer film having a second electrode disposed on a lower surface of the piezoelectric ceramic layer, wherein the second electrode is disposed to abut on a lower surface of the piezoelectric ceramic layer; And a substrate disposed under the polymer film, wherein the substrate is connected to each other through the piezoelectric ceramic and an elastic body.

The second electrodes are formed on both sides of the polymer film, and the second electrodes formed on both sides are in electrical communication with each other through an opening passing through the polymer film.

The elastic body is in contact with the substrate and the piezoelectric ceramic layer, and the polymer film is spaced apart from the substrate.

Both surfaces of the piezoelectric ceramic layer are coated with a metal.

The metal plate is in the form of a horn.

According to a further embodiment of the present invention, a piezoelectric transducer includes: n x m metal plates having a first electrode formed thereon; N x m piezoelectric ceramic layers disposed to be in contact with the first electrode; An n x m polymer film having a second electrode disposed on a lower surface of the piezoelectric ceramic layer, the second electrode being a polymer film disposed to be in contact with the lower surface of the piezoelectric ceramic layer; And a substrate disposed under the polymer film, wherein the substrate is connected to each other through the piezoelectric ceramic and an elastic body.

The second electrodes are formed on both sides of the polymer film, and the second electrodes formed on both sides are in electrical communication with each other through an opening passing through the polymer film.

The elastic body is in contact with the substrate and the piezoelectric ceramic layer, and the polymer film is spaced apart from the substrate.

A second electrode pattern is formed on the polymer film in advance so that the second electrodes are in electrical communication with each other.

The piezoelectric transducer array according to the present invention can be manufactured by a mass production method. The present invention provides such a novel piezoelectric transducer array.

1 shows a flowchart of a method of manufacturing a piezoelectric transducer according to an embodiment of the present invention.
2A-2D show schematic diagrams of a method of manufacturing a piezoelectric transducer according to an embodiment of the present invention.
3 shows a schematic cross-sectional view of a piezoelectric transducer according to an embodiment of the present invention.
4 shows a flowchart of a method of manufacturing a piezoelectric transducer array according to a further embodiment of the present invention.
FIG. 5 illustrates a metal plate, a first electrode, a second electrode, a polymer film, and a ceramic layer used in the process of making a plurality of structure arrays using an FPCB process.
6 shows a top view of a piezoelectric transducer array according to a further embodiment of the present invention.
FIG. 7 illustrates a state in which electrical wiring is installed below the piezoelectric ceramic layer in the piezoelectric transducer of the present invention.
Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, various details are set forth in order to provide an understanding of the invention. It is evident, however, that such embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the embodiments.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, step, operation, component, part, or combination thereof described on the specification, and one or more other features or steps. It is to be understood that the present invention does not exclude, in advance, the possibility of the presence or addition of any operation, component, part, or combination thereof.

The present invention seeks to provide a piezoelectric transducer array that can be mass produced in the manufacture of piezoelectric transducers, and also to a method for mass production of such piezoelectric transducer arrays. Hereinafter, a method of manufacturing a piezoelectric transducer according to an embodiment of the present invention will be described, and the structure will be described later.

1 shows a flowchart of a method of manufacturing a piezoelectric transducer according to an embodiment of the present invention. 2A-2D show schematic diagrams of a method of manufacturing a piezoelectric transducer according to an embodiment of the present invention.

As shown in FIG. 1, a method of manufacturing a piezoelectric transducer according to an embodiment of the present invention includes preparing a metal plate having a first electrode formed on one surface thereof (S 110); Preparing a piezoelectric ceramic layer (S 120); Attaching a piezoelectric ceramic layer such that the first electrode abuts on one surface of the piezoelectric ceramic layer (S 130); Preparing a polymer film having a second electrode pattern formed on one surface (S 140); Attaching a polymer film to the other surface of the piezoelectric ceramic layer to be in contact with the second electrode (S 150); And preparing a substrate, and attaching the substrate and the piezoelectric ceramic layer to each other using an elastic body (S 160).

In step S110, a metal plate is prepared. The metal plate 10 vibrates integrally by combining with a piezoelectric body in the piezoelectric transducer of the present invention. When an electric signal is applied, a physical vibration signal is generated through the metal plate, which is generated as an acoustic signal such as sound waves or ultrasonic waves. Can be. Conversely, when a vibration signal is applied, an electrical signal may be generated. Such a metal plate may be in the form of a horn. A first electrode is formed on one surface of the metal plate 10, and the wiring of the first electrode is preferably drawn out under the piezoelectric ceramic layer described later. As a result, the wiring of the first electrode and the second electrode is not removed from the upper and lower portions of the piezoelectric ceramic layer, respectively, and both electrodes are removed only from the second electrode side. Has the advantage of being able to. In order to make the electrical wiring below the piezoelectric ceramic layer, the connecting portion of the electrode from the first electrode to the second electrode may be extended through the side surface of the piezoelectric ceramic layer or disposed through the piezoelectric ceramic layer, and the first electrode and the second electrode may be disposed. The electrodes are kept insulated from each other. FIG. 7 illustrates a state in which electrical wiring is installed below the piezoelectric ceramic layer in the piezoelectric transducer of the present invention. As shown in FIG. 7, the first electrode was connected to the lower part by wiring to enable (+) and (-) wiring from the first electrode and the second electrode at the lower part, respectively. The polarities can be altered from one another.

Meanwhile, the first electrodes may be insulated from each other so as not to be in direct electrical communication with the metal plate.

In step S 120, the piezoelectric ceramic layer 30 is prepared. The piezoelectric ceramic layer may be any piezoelectric ceramic as long as it is available as a piezoelectric ceramic, and there is no particular limitation thereto. Both surfaces of the piezoelectric ceramic layer may be coated with a metal.

In operation S 130, the piezoelectric ceramic layer is attached to one surface of the piezoelectric ceramic layer so that the first electrode 25 abuts.

In operation S 140, the polymer film 40 having the second electrode pattern 45 formed on one surface may be prepared. In the present invention, the FPCB process is used to prepare a polymer film having the second electrode formed thereon, and the electrode may be used as long as it is an electrode material, and the polymer film may use PET, PI, and the like, but is not limited thereto. The content described is for the case of using the single-sided FPCB process, and in the present invention, it may be produced using the double-sided FPCB process. When fabricated using a double-sided FPCB process, a second electrode is formed on both sides of the polymer film, the second electrode formed on both sides are in electrical communication with each other through the opening through the polymer film. This can be seen in the embodiment of FIG. As such, in the present invention, both a single-sided FPCB process or a double-sided FPCB process can be used. In the case of using the double-sided FPCB process, a structure for forming a plurality of arrays has an advantage of easily fabricating a pattern for electrode wiring between the plurality of arrays, which will be described in detail later.

In step S 150, the polymer film 40 is attached to the other surface of the piezoelectric ceramic layer 30, that is, the surface opposite to the surface in contact with the first electrode, such that the second electrode abuts. After attaching, heat is applied to heat fusion.

In step S 160, the substrate 50 is prepared, and the substrate 50 and the piezoelectric ceramic layer 30 are attached to each other using the elastic body 60. The substrate may be made of a flexible material. The elastic body 60 is a rubber-like object made of an elastic material, and the elastic body adheres the substrate and the piezoelectric ceramic layer to each other. As a result, the elastic body 60 is in contact with the substrate 50 and the piezoelectric ceramic layer 30, and the polymer film 40 is spaced apart from the substrate 50.

4 shows a flowchart of a method of manufacturing a piezoelectric transducer array according to a further embodiment of the present invention.

As shown in FIG. 4, a method of manufacturing a piezoelectric transducer array according to an exemplary embodiment of the present invention includes preparing n x m metal plates having a first electrode formed on one surface (S 210); preparing n x m piezoelectric ceramic layers (S 220); Attaching a piezoelectric ceramic layer such that the first electrode abuts on one surface of the piezoelectric ceramic layer (S 230); Preparing n x m polymer films having a second electrode pattern formed on one surface (S 240); Attaching a polymer film to the other surface of the piezoelectric ceramic layer to be in contact with the second electrode (S 250); And preparing a substrate, and attaching the substrate and the piezoelectric ceramic layer to each other using an elastic body (S260), wherein n and m are integers of 1 or more.

While the embodiment of FIG. 1 relates to a method of manufacturing one piezoelectric transducer, the embodiment of FIG. 4 relates to a method of manufacturing a structure in which a plurality of piezoelectric transducers are arrayed. In the present invention, as described above, even when manufacturing a plurality of piezoelectric transducer array using the FPCB process can be easily produced by batch production step by step.

In step S 210, n x m metal plates having the first electrode 25 formed on one surface thereof are prepared. The metal plate 10 vibrates integrally by combining with a piezoelectric body in the piezoelectric transducer of the present invention. When an electric signal is applied, a physical vibration signal is generated through the metal plate, which is generated as an acoustic signal such as sound waves or ultrasonic waves. Can be. Conversely, when a vibration signal is applied, an electrical signal may be generated. Such a metal plate may be in the form of a horn. In the present specification, n and m are integers of 1 or more. Meanwhile, the first electrodes may be insulated from each other so as not to be in direct electrical communication with the metal plate.

In step S 220, n x m piezoelectric ceramic layers 30 are prepared. The piezoelectric ceramic layer may be any piezoelectric ceramic as long as it is available as a piezoelectric ceramic, and there is no particular limitation thereto. Both surfaces of the piezoelectric ceramic layer may be coated with a metal.

In step S 230, the piezoelectric ceramic layer is attached to one surface of the piezoelectric ceramic layer so that the first electrode 25 abuts.

In operation S 240, n x m polymer films 40 having the second electrode pattern 45 formed on one surface may be prepared. In the present invention, the FPCB process is used to prepare a polymer film having the second electrode formed thereon, and the electrode may be used as long as it is an electrode material, and the polymer film may use PET, PI, and the like, but is not limited thereto. In this case, it is preferable that the second electrode pattern is formed on the polymer film in advance so as to allow electrical communication between the second electrodes.

The above description is for the case of using the single-sided FPCB process, it can also be produced using the double-sided FPCB process in the present invention. When fabricated using a double-sided FPCB process, a second electrode is formed on both sides of the polymer film, the second electrode formed on both sides are in electrical communication with each other through the opening through the polymer film. As such, in the present invention, both a single-sided FPCB process or a double-sided FPCB process can be used. In the case of using a double-sided FPCB process, a structure for forming a plurality of arrays has an advantage of easily manufacturing a pattern for electrode wiring between the plurality of arrays. 5 actually shows a metal plate, a first electrode, a second electrode, a polymer film, and a ceramic layer used in the process of making a plurality of structure arrays using a double-sided FPCB process. As shown in FIG. 5, the piezoelectric transducer array can be manufactured very easily by using a pre-patterned electrode at a time, and wiring can be easily performed between the piezoelectric transducers in the manufactured array. 5 is a schematic diagram of a material used in a piezoelectric transducer array according to a further embodiment of the present invention, and FIG. 6 shows a plan view of a piezoelectric transducer array according to a further embodiment of the present invention. As shown in FIG. 6, wiring between the piezoelectric transducers is made very easily, and thus, each piezoelectric transducer structure may be manufactured and then manufactured in a simpler form and easier than in the prior art of arranging the piezoelectric transducer structures. In FIG. 5, the metal plate 10 is shown as one large plate, but in practice is n x m, in the example of FIG. 5 will be 7 x 8. 5 and 6, the metal plate 10, the first electrode 25, the second electrode 45, the polymer film 40, and the ceramic layer 30 are respectively as shown in FIG. 2D or 3. Include. 5 is an exploded view showing the metal plate 10, the first electrode 25, the second electrode 45, and the polymer film 40. ACP is the part that performs the adhesive role as the conductive adhesive. In the case of Figure 6 shows the actual wiring between the piezoelectric transducers. The wiring is formed between the first electrode and the wiring between the second electrode. In FIG. 6, the wiring between the first electrode is represented as a negative electrode for convenience, and the wiring between the second electrode is positive. Although shown as an electrode, this is a part that can be changed according to use. In FIG. 6, the metal plates 10 are shown, the first electrode 25 is shown, the first electrodes 25 are connected to each other and are indicated by a (-) wiring, and the circular portion is a double-sided FPCB. It means the second electrode 45 produced through the process and they are connected to each other and are represented by (+) wiring.

As shown in FIG. 6, the wiring of each of the first electrode and the second electrode of the two solid wires is removed from the lower part of the piezoelectric ceramic layer so that the wiring can be easily performed and the wiring can be easily performed in a batch.

In operation S 250, the polymer film 40 is attached to the other surface of the piezoelectric ceramic layer 30, that is, the surface opposite to the surface contacting the first electrode, such that the second electrode abuts. After attaching, heat is applied to heat fusion.

In operation S260, the substrate 50 is prepared, and the substrate 50 and the piezoelectric ceramic layer 30 are attached to each other by using the elastic body 60. The substrate may be made of a flexible material. The elastic body 60 is a rubber-like object made of an elastic material, and the elastic body adheres the substrate and the piezoelectric ceramic layer to each other. As a result, the elastic body 60 is in contact with the substrate 50 and the piezoelectric ceramic layer 30, and the polymer film 40 is spaced apart from the substrate 50.

So far, the method of manufacturing the piezoelectric transducer according to the exemplary embodiment of the present invention and the method of manufacturing the piezoelectric transducer array according to an additional exemplary embodiment of the present invention have been described. Hereinafter, the piezoelectric transducer and its array will be described. would. Repeated description will be omitted for the overlapping parts described above.

A piezoelectric transducer according to an embodiment of the present invention is shown in FIG. 2D, which includes a metal plate 10 having a first electrode formed thereon; A piezoelectric ceramic layer 30 disposed to be in contact with the first electrode; A polymer film 40 having a second electrode disposed on a lower surface of the piezoelectric ceramic layer; And a substrate 50 disposed under the polymer film.

The first electrode is formed and disposed on the lower surface of the metal plate 10. The metal plate is preferably in the form of a horn. Meanwhile, the first electrodes may be insulated from each other so as not to be in direct electrical communication with the metal plate.

The piezoelectric ceramic layer 30 is disposed to contact the first electrode 25. Both surfaces of the piezoelectric ceramic layer may be coated with a metal.

The polymer film 40 is disposed on the lower surface of the piezoelectric ceramic layer 30, and the second electrode 45 is formed on the polymer film, and the second electrode is disposed to contact the lower surface of the piezoelectric ceramic layer 30. .

The substrate 50 is disposed below the polymer film 40, and the substrate 50 and the piezoelectric ceramic layer 30 are connected through the elastic body 60. An elastic body is in contact with the substrate and the piezoelectric ceramic layer, whereby the polymer film is spaced apart from the substrate.

When the electrical signal is applied through the first electrode and the second electrode disposed on the upper and lower portions of the piezoelectric ceramic layer 30 through such a structure, a mechanical deformation of the piezoelectric ceramic layer is generated, and correspondingly the metal Vibration occurs as the plate deforms, which can be emitted in the form of sound waves or ultrasonic waves. This makes it possible to act as a speaker. In this case, as described above, the wiring can be easily carried out by releasing the wiring to either one of the piezoelectric ceramic layers (downward in the present invention).

According to a further embodiment of the present invention, an array of piezoelectric transducer structures is provided, which means that n x m piezoelectric transducers are arranged in an array form. When the n x m piezoelectric transducers are arranged in an array form, the piezoelectric transducer may be used as a directional piezoelectric speaker when used as a piezoelectric energy harvester array or a speaker.

According to a further embodiment of the present invention, a piezoelectric transducer array includes: n x m metal plates having a first electrode formed thereon; N x m piezoelectric ceramic layers disposed to be in contact with the first electrode; An n x m polymer film having a second electrode disposed on a lower surface of the piezoelectric ceramic layer, the second electrode being a polymer film disposed to be in contact with the lower surface of the piezoelectric ceramic layer; And a substrate disposed under the polymer film, wherein the substrate is connected to each other through the piezoelectric ceramic and an elastic body.

The first electrode is formed and disposed on the lower surface of the metal plate. The metal plate is preferably in the form of a horn. Meanwhile, the first electrodes may be insulated from each other so as not to be in direct electrical communication with the metal plate.

The elastic body is in contact with the substrate and the piezoelectric ceramic layer, and the polymer film is spaced apart from the substrate.

Both surfaces of the piezoelectric ceramic layer may be coated with a metal, and the metal plate is preferably in a horn form.

In addition, the first electrode pattern is formed in advance so that the electrical communication between the first electrodes, and the second electrode pattern is formed in the polymer film in advance so that the electrical communication between the second electrodes. desirable. The electrode pattern makes wiring much more convenient than wiring the piezoelectric transducers individually in an array form, which can be seen in FIG. 6. 6 shows an array of eight 7 x 8 horizontally by 7 x vertical, with each square representing one piezoelectric transducer structure. This piezoelectric transducer structure is composed of elements of the form as shown in Figure 2d or 3, it can be seen that these elements are wired through the first electrode pattern and the second electrode pattern prepared in advance.

As described above, the piezoelectric transducer array according to the present invention can be manufactured by a mass production method. The present invention provides such a novel piezoelectric transducer array. This piezoelectric transducer of the present invention can be used for energy harvesting and can also be used as a speaker.

The description of the presented embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention should not be limited to the embodiments set forth herein but should be construed in the broadest scope consistent with the principles and novel features set forth herein.

Claims (15)

Preparing a metal plate having a first electrode formed on one surface thereof;
Preparing a piezoelectric ceramic layer;
Attaching a piezoelectric ceramic layer so that the first electrode abuts on one surface of the piezoelectric ceramic layer;
Preparing a polymer film having a second electrode pattern formed on one surface thereof;
Attaching a polymer film to the other surface of the piezoelectric ceramic layer to be in contact with the second electrode; And
Preparing a substrate, and attaching the substrate and the piezoelectric ceramic layer to each other using an elastic body,
The elastic body is in contact with the substrate and the piezoelectric ceramic layer, the polymer film is disposed spaced apart from the substrate,
Method of manufacturing piezoelectric transducers.
delete The method of claim 1,
Both sides of the piezoelectric ceramic layer is coated with a metal,
Method of manufacturing piezoelectric transducers.
The method of claim 1,
The metal plate is in the form of a horn,
Method of manufacturing piezoelectric transducers.
Preparing nxm metal plates having a first electrode formed on one surface thereof;
preparing nxm piezoelectric ceramic layers;
Attaching a piezoelectric ceramic layer so that the first electrode abuts on one surface of the piezoelectric ceramic layer;
Preparing nxm polymer films having a second electrode pattern formed on one surface thereof;
Attaching the polymer film to the second surface of the piezoelectric ceramic layer to be in contact with the second electrode; And
Preparing a substrate, and attaching the substrate and the piezoelectric ceramic layer to each other using an elastic body,
n and m are integers of 1 or more,
The elastic body is in contact with the substrate and the piezoelectric ceramic layer, the polymer film is disposed spaced apart from the substrate,
Method of manufacturing piezoelectric transducers.
delete The method of claim 5,
A second electrode pattern is formed on the polymer film in advance so that the second electrodes are in electrical communication with each other.
Method of manufacturing piezoelectric transducers.
A metal plate having a first electrode disposed on a bottom surface thereof;
A piezoelectric ceramic layer disposed to contact the first electrode;
A polymer film having a second electrode disposed on a lower surface of the piezoelectric ceramic layer, wherein the second electrode is disposed to abut on a lower surface of the piezoelectric ceramic layer; And
A substrate disposed under the polymer film, the substrate comprising a substrate connected to each other through the piezoelectric ceramic and an elastic body;
The elastic body is in contact with the substrate and the piezoelectric ceramic layer, the polymer film is spaced apart from the substrate,
Piezoelectric transducer.
The method of claim 8,
The second electrode is formed on both sides of the polymer film, the second electrode formed on both sides are in electrical communication with each other through the opening through the polymer film,
Piezoelectric transducer.
delete The method of claim 8,
Both sides of the piezoelectric ceramic layer is coated with a metal,
Piezoelectric transducer.
Nxm metal plates on which first electrodes are formed;
Nxm piezoelectric ceramic layers disposed to be in contact with the first electrode;
An nxm polymer film having a second electrode disposed on a lower surface of the piezoelectric ceramic layer, wherein the second electrode is disposed so as to contact the lower surface of the piezoelectric ceramic layer; And
A substrate disposed under the polymer film, the substrate comprising a substrate connected to each other through the piezoelectric ceramic and an elastic body;
The elastic body is in contact with the substrate and the piezoelectric ceramic layer, the polymer film is spaced apart from the substrate,
Piezoelectric transducer.
The method of claim 12,
The second electrode is formed on both sides of the polymer film, the second electrode formed on both sides are in electrical communication with each other through the opening through the polymer film,
Piezoelectric transducer.
delete The method of claim 12,
A second electrode pattern is formed on the polymer film in advance so that the second electrodes are in electrical communication with each other.
Piezoelectric transducer.

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