A flexible 1-3 type piezoelectric composite material with embedded thin film circuit and its preparation method

Abstract

The present invention relates to a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit and a preparation method thereof. The flexible 1-3 type piezoelectric composite material includes a flexible 1-3 type piezoelectric composite layer, a positive electrode layer, a negative electrode layer, a positive embedded thin film circuit layer and a negative embedded thin film circuit layer; the flexible 1-3 type piezoelectric composite layer includes a periodically arranged piezoelectric small column material and a flexible polymer material; the positive electrode layer and the negative electrode layer are respectively covered on both sides of the periodically arranged piezoelectric small column material; the positive embedded thin film circuit and the negative embedded thin film circuit are respectively covered on both sides of the positive electrode layer and the negative electrode layer; the embedded thin film circuit includes a periodically arranged node structure and a periodically arranged curved connection structure, and the periodically arranged curved connection structure is embedded in the flexible polymer material. The present invention solves the problem that existing flexible piezoelectric materials cannot be arbitrarily bent and cannot be used as high-power transmitting transducers.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible piezoelectric materials, and in particular relates to a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit and a preparation method thereof. Background Art

[0002] In recent years, with the growing demand for underwater detection and communication technologies, and the development of flexible underwater acoustic detection equipment, flexible piezoelectric composites, as core components in flexible transducers, have become a research focus in the underwater acoustics field. Flexible piezoelectric composites are a new type of piezoelectric material with excellent properties: low density, low weight, and good acoustic impedance matching with water; high electromechanical coupling coefficient, resulting in high energy conversion efficiency in the resulting transducers; and flexibility, making them adaptable to a variety of underwater acoustic equipment. Therefore, they are considered ideal materials for flexible transducers. Common flexible piezoelectric composites include 0-3 type piezoelectric composites and 1-3 type piezoelectric composites. 0-3 type piezoelectric composites are made by hot-pressing piezoelectric material particles mixed with metal / ferroelectric nanomaterials to form a soft and thin flexible piezoelectric composite. However, their piezoelectric coefficient is relatively low, making them commonly used in receiving transducers. 1-3 type piezoelectric composites are composed of a one-dimensionally conductive piezoelectric material and a three-dimensionally conductive flexible polymer material. The piezoelectric material is cylindrical, with a distinct thickness vibration mode, enabling high power output in a resonant state. However, the flexible polymers in existing 1-3 piezoelectric composite materials are mostly made of epoxy resin, resulting in composite materials with poor flexibility and inflexibility. Furthermore, the production of flexible transducers requires the addition of flexible thin-film circuits at both ends of the composite material. Existing flexible thin-film circuits are made by forming copper foil circuits into an elastically connected "island bridge" structure. However, this elastic connection requires the copper foil to be as narrow as possible, resulting in poor ability to withstand high currents, which in turn prevents the transducer from being used for high-power transmitting transducers.

[0003] So far, there has been no report on flexible transducers using embedded thin-film circuits to achieve flexible 1-3 type piezoelectric composite materials that can be bent arbitrarily. Summary of the Invention

[0004] In response to the above-mentioned deficiencies and defects of the prior art, the present invention provides a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit and a preparation method thereof, which provides a new idea for solving the problem that the existing flexible piezoelectric materials cannot be bent arbitrarily and cannot be used as high-power transmitting transducers.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A flexible 1-3 type piezoelectric composite material with an embedded thin film circuit, comprising a flexible 1-3 type piezoelectric composite layer, a positive electrode layer, a negative electrode layer, a positive embedded thin film circuit layer and a negative embedded thin film circuit layer; the flexible 1-3 type piezoelectric composite layer comprises periodically arranged piezoelectric small column materials and a flexible polymer material, and the flexible polymer material is located in the gaps between the periodically arranged piezoelectric small column materials; the positive electrode layer and the negative electrode layer respectively cover both sides of the periodically arranged piezoelectric small column materials; the positive embedded thin film circuit and the negative embedded thin film circuit respectively cover both sides of the positive electrode layer and the negative electrode layer; the embedded thin film circuit comprises a periodically arranged node structure and a periodically arranged curved connection structure, and the periodically arranged curved connection structure is embedded in the flexible polymer material.

[0007] Furthermore, the piezoelectric pillar material is piezoelectric ceramic or piezoelectric single crystal.

[0008] Furthermore, the flexible polymer material is a silicone rubber material; the silicone rubber material is poured into the gaps between the periodically arranged piezoelectric pillar materials.

[0009] Furthermore, the positive and negative electrode layer materials are metal electrodes; the metal electrode layers are made by electroplating, sputtering or screen printing.

[0010] Furthermore, the embedded thin film circuit is made of a metal thin film material; the thickness of the metal thin film does not exceed 100um.

[0011] Furthermore, the periodically arranged node structures correspond to the electrode layers and are connected by bonding or welding; the bonding is performed by a high-strength adhesive; and the welding is performed by soldering.

[0012] Furthermore, the curved connection structure cannot contact the piezoelectric material; the curved connection structure is cast in a flexible polymer material.

[0013] A method for preparing a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit, characterized by specifically comprising:

[0014] 1) Cutting the bulk piezoelectric material into a periodically arranged array of piezoelectric material columns along the length and width directions, with the cutting thickness being half the thickness of the piezoelectric material;

[0015] 2) preparing a metal electrode layer on the surface of the periodically arranged piezoelectric pillars obtained in step 1);

[0016] 3) aligning the periodically arranged node structure in the embedded thin film circuit with the electrode layer obtained in step 2), firmly connecting the node structure to the electrode layer, and then embedding the curved connection structure into the gaps of the piezoelectric material pillar array;

[0017] 4) pouring a flexible polymer material into the gaps of the piezoelectric material column array and curing the material;

[0018] 5) turning over the structure obtained in step 4) and cutting according to step 1);

[0019] 6) preparing a metal electrode layer on the surface of the periodically arranged small pillars obtained in step 5) according to step 2);

[0020] 7) aligning the embedded thin film circuit with the electrode layer obtained in step 6), firmly connecting the node structure to the electrode layer, and then embedding the curved connection structure into the gaps of the piezoelectric material pillar array;

[0021] 8) A flexible polymer material is poured into the gaps of the piezoelectric material column array structure obtained in step 7), and after curing, a flexible 1-3 type piezoelectric composite material is formed.

[0022] Furthermore, in steps 2) and 6) a metal electrode layer is prepared by electroplating, sputtering or screen printing; and in steps 3) and 7) the node structure is firmly connected to the electrode layer by bonding with a high-strength adhesive or welding.

[0023] The beneficial effects of the present invention compared with the prior art include: the present invention designs a new embedded flexible film circuit, which has the following advantages:

[0024] First, the curved connection part of the flexible film circuit is embedded in a flexible polymer material. When bending, the flexible polymer and the curved connection part expand and contract synchronously, thereby protecting the flexible film circuit.

[0025] Secondly, the curved connection part is wider and thicker, which can withstand large currents, thereby enabling the transducer to have the function of high-power transmission.

[0026] The metal film circuit is then connected to the piezoelectric pillars via an electrode layer. The thickness of the electrode layer is much smaller than the wavelength of the sound wave, and the piezoelectric material surface does not need to be covered with a flexible silicon film material with sound absorption and vibration reduction, which can significantly reduce acoustic energy loss.

[0027] Then, the periodically arranged node structure and the periodically arranged curved connection structure in the embedded thin film circuit can be made of a grid structure composed of a single metal material, which has good tensile properties and flexibility, a large width, good bending and stretching resistance, and can withstand large currents. The preparation method is simple and can be integrated into an integrated mold.

[0028] Finally, the flexible 1-3 piezoelectric composite material adopts a sandwich symmetrical structure design of "embedded thin film circuit-flexible piezoelectric composite layer-embedded thin film circuit". On the one hand, the flexible composite material can be bent arbitrarily, and on the other hand, it can withstand greater hydrostatic pressure, allowing the flexible transducer to work in the deep sea. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit disclosed in Example 1 of the present invention.

[0030] Figure 2 It is a schematic structural diagram of the embedded thin film circuit disclosed in Example 1 of the present invention.

[0031] Figure 3 This is a schematic structural diagram of a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit disclosed in Example 2 of the present invention.

[0032] Figure 4 It is a schematic structural diagram of the embedded thin film circuit disclosed in Example 2 of the present invention.

[0033] Figure 5 This is a flow chart for preparing a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit disclosed in Example 3 of the present invention.

[0034] Figure 6 is the piezoelectric constant d of a flexible 1-3 type piezoelectric composite material with embedded thin film circuit disclosed in Example 4 of the present invention. 33 value. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings and in combination with preferred embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0036] Example 1:

[0037] like Figure 1 As shown, this embodiment provides a flexible 1-3 type piezoelectric composite material with embedded thin-film circuits, comprising a flexible 1-3 type piezoelectric composite layer 1, a positive electrode layer 21, a negative electrode layer 22, a positive embedded thin-film circuit 31, and a negative embedded thin-film circuit 32. The flexible 1-3 type piezoelectric composite layer 1 comprises a piezoelectric material pillar array 4 and a flexible polymer material 5. The positive electrode layer 21 and the negative electrode layer 22 are identical, covering both sides of the periodically arranged piezoelectric pillar material.

[0038] like Figure 2As shown, the positive electrode embedded thin film circuit 31 and the negative electrode embedded thin film circuit 32 are consistent, covering the positive and negative electrode layers respectively; the embedded thin film circuit includes a periodically arranged node structure and a periodically arranged curved connection structure.

[0039] In some preferred embodiments, the material of the piezoelectric pillar is piezoelectric ceramic.

[0040] In some preferred embodiments, the flexible polymer material is a silicone rubber material, and the silicone rubber material is cast in the gaps between the periodically arranged piezoelectric pillar materials.

[0041] In some preferred embodiments, the positive and negative electrode layer materials are silver electrode materials, which are prepared by magnetron sputtering process.

[0042] In some preferred embodiments, the embedded thin film circuit is made of a metal thin film material; the thickness of the metal film is 100 um.

[0043] In some preferred embodiments, the periodically arranged node structures correspond to the electrode layers and are connected by welding; the welding is performed by soldering.

[0044] In some preferred embodiments, the periodically arranged curved connection structures are embedded in the gaps of the piezoelectric material pillar array; the curved connection structures cannot contact the piezoelectric material; and the curved connection structures are cast in a flexible polymer material.

[0045] Example 2:

[0046] like Figure 3 As shown, this embodiment provides a flexible 1-3 type piezoelectric composite material with embedded thin-film circuits, comprising a flexible 1-3 type piezoelectric composite layer 1, a positive electrode layer 21, a negative electrode layer 22, a positive embedded thin-film circuit 31, and a negative embedded thin-film circuit 32. The flexible 1-3 type piezoelectric composite layer 1 comprises a piezoelectric material pillar array 4 and a flexible polymer material 5. The positive electrode layer 21 and the negative electrode layer 22 are identical, covering both sides of the periodically arranged piezoelectric pillar material.

[0047] like Figure 4 As shown, the positive electrode embedded thin film circuit and the negative electrode embedded thin film circuit are consistent, covering the positive and negative electrode layers respectively; the embedded thin film circuit includes a periodically arranged node structure and a periodically arranged curved connection structure.

[0048] In some preferred embodiments, the piezoelectric pillar material is a piezoelectric single crystal.

[0049] In some preferred embodiments, the flexible polymer material is a silicone rubber material, and the silicone rubber material is cast in the gaps between the periodically arranged piezoelectric pillar materials.

[0050] In some preferred embodiments, the positive and negative electrode layer materials are gold electrode materials, which are produced by screen printing technology.

[0051] In some preferred embodiments, the embedded thin film circuit is made of a metal thin film material; the thickness of the metal film is 100 um.

[0052] In some preferred embodiments, the periodically arranged node structures correspond to the electrode layers and are connected by bonding; the bonding is performed using a high-strength adhesive.

[0053] In some preferred embodiments, the periodically arranged curved connection structures are embedded in the gaps of the piezoelectric material pillar array; the curved connection structures cannot contact the piezoelectric material; and the curved connection structures are cast in a flexible polymer material.

[0054] Example 3:

[0055] This embodiment discloses a method for preparing a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit, such as Figure 5 As shown, specifically including:

[0056] 1) Cutting the bulk piezoelectric material into a periodically arranged array of piezoelectric material columns along the length and width directions, with the cutting thickness being half the thickness of the piezoelectric material;

[0057] 2) Aligning the periodically arranged node structures in the embedded thin-film circuit with the electrode layers on the surfaces of the periodically arranged piezoelectric pillars obtained in step 1) one by one, bonding them with high-strength conductive silver glue (the conductive silver glue serves as the electrode layer), and then embedding the curved connection structure into the gaps in the piezoelectric pillar array;

[0058] 3) pouring silicone rubber material into the gaps of the piezoelectric material column array and curing it;

[0059] 4) turning over the structure obtained in step 3) and cutting according to step 1);

[0060] 5) According to step 2), the periodically arranged node structure in the embedded thin-film circuit is aligned with the electrode layer obtained in step 4), and they are bonded with high-strength conductive silver glue (the conductive silver glue serves as the electrode layer), and then the curved connection structure is embedded in the gaps of the piezoelectric material pillar array;

[0061] 6) Pour silicone rubber material into the gaps of the piezoelectric material column array structure obtained in step 5), and after curing, form a flexible 1-3 type piezoelectric composite material.

[0062] In some preferred embodiments, the high-strength conductive silver paste in steps 3) and 6) is a low-temperature curing conductive silver paste.

[0063] Example 4:

[0064] This embodiment is the same as the preparation method of a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit disclosed in Example 3. In step 1) of this embodiment, the length, width and height of the piezoelectric pillars are all 5 mm, and the spacing between the piezoelectric pillar arrays is 2 mm.

[0065] The piezoelectric composite material prepared in this embodiment was tested. Figure 6 As shown in FIG. 1 , the piezoelectric constant d of the flexible 1-3 type piezoelectric composite material with embedded thin film circuit prepared in this embodiment is 33 It can reach 491pC / N.

[0066] It can be seen from the above embodiments that the flexible 1-3 type piezoelectric composite material is bent through the flexible polymer, and the embedded thin film circuit realizes the conduction of the electrode on the surface of the composite material. The embedded thin film circuit expands and contracts with the expansion and contraction of the flexible polymer; its structure adopts a sandwich structure, which can ensure the bidirectional bending of the composite material and has resistance to high hydrostatic pressure, and is suitable for the preparation of flexible high-power underwater acoustic emission transducers.

[0067] The present invention improves the existing flexible thin film circuit. After the "bridge" connection structure in the island-bridge structure is bent, it is embedded in a flexible polymer. In this way, when the flexible composite material is bent, the "bridge" connection structure is bent to achieve flexible connection, and its width is increased, which can withstand large currents. This is of great significance for the research and application of flexible emission-type underwater acoustic transducers.

[0068] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to the above description. For those skilled in the art of the art to which the present invention belongs, it is possible to make several equivalent substitutions or obvious modifications without departing from the concept of the present invention, and the performance or use of the same should be considered to fall within the scope of protection of the present invention.

Claims

1. A flexible 1-3 type piezoelectric composite material with an embedded thin film circuit, characterized in that: It includes a flexible 1-3 type piezoelectric composite layer, a positive electrode layer, a negative electrode layer, a positive embedded thin film circuit layer and a negative embedded thin film circuit layer; the flexible 1-3 type piezoelectric composite layer includes periodically arranged piezoelectric small column materials and flexible polymer materials, and the flexible polymer material is located in the gaps of the periodically arranged piezoelectric small column materials; the positive electrode layer and the negative electrode layer are respectively covered on both sides of the periodically arranged piezoelectric small column materials; the positive embedded thin film circuit and the negative embedded thin film circuit are respectively covered on both sides of the positive electrode layer and the negative electrode layer; the embedded thin film circuit includes a periodically arranged node structure and a periodically arranged curved connection structure, and the periodically arranged curved connection structure is embedded in the flexible polymer material.

2. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 1, characterized in that: The piezoelectric pillar material is piezoelectric ceramics or piezoelectric single crystal.

3. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 1, characterized in that: The flexible polymer material is a silicone rubber material; the silicone rubber material is poured into the gaps between the periodically arranged piezoelectric pillar materials.

4. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 1, characterized in that: The positive electrode layer and the negative electrode layer are metal electrodes, which are made by electroplating, sputtering or screen printing.

5. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 1, characterized in that: The embedded thin film circuit is made of a metal thin film material, and its thickness does not exceed 100um.

6. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 1, characterized in that: The periodically arranged node structures correspond to the positive electrode layer and the negative electrode layer and are connected by bonding or welding.

7. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 6, characterized in that: The bonding is performed by an adhesive; and the welding is performed by soldering.

8. The flexible 1-3 type piezoelectric composite material with embedded thin film circuit according to claim 1, characterized in that: The flexure connection structure cannot be in contact with the piezoelectric material; the flexure connection structure is cast in a flexible polymer material.

9. A method for preparing a flexible 1-3 type piezoelectric composite material with an embedded thin film circuit, characterized in that: The following steps are involved: 1) Cutting the bulk piezoelectric material into a periodically arranged array of piezoelectric material columns along the length and width directions, with the cutting thickness being half the thickness of the piezoelectric material; 2) preparing a metal electrode layer on the surface of the periodically arranged piezoelectric pillars obtained in step 1); 3) aligning the periodically arranged node structure in the embedded thin film circuit with the electrode layer obtained in step 2), firmly connecting the node structure to the electrode layer, and then embedding the curved connection structure into the gaps of the piezoelectric material pillar array; 4) pouring a flexible polymer material into the gaps of the piezoelectric material column array and curing the material; 5) turning over the structure obtained in step 4) and cutting according to step 1); 6) preparing a metal electrode layer on the surface of the periodically arranged small pillars obtained in step 5) according to step 2); 7) aligning the embedded thin-film circuit with the electrode layer obtained in step 6), firmly connecting the node structure to the electrode layer, and then embedding the curved connection structure into the gaps of the piezoelectric material pillar array; 8) A flexible polymer material is poured into the gaps of the piezoelectric material column array structure obtained in step 7), and after curing, a flexible 1-3 type piezoelectric composite material is formed.

10. The preparation method according to claim 9, characterized in that Steps 2) and 6) prepare a metal electrode layer by electroplating, sputtering or screen printing; Steps 3) and 7) firmly connect the node structure to the electrode layer by bonding with an adhesive or welding.

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