A design method for lightweight backing of piezoelectric membrane surface element hydrophone

Abstract

The present invention relates to the technical field of hydrophones, and in particular to a design method for a lightweight backing of a piezoelectric film face element hydrophone, comprising a face element hydrophone, wherein the face element hydrophone comprises a sensing element, a watertight structure and a preamplifier circuit, wherein the sensing element comprises a backing plate and a piezoelectric film, wherein the upper and lower surfaces and the side surfaces of the backing plate are coated with silver paste electrodes, the piezoelectric film is bonded to the upper and lower surfaces of the backing plate, the watertight structure comprises a rubber sleeve and a polyurethane layer, the sensing element is connected to the preamplifier circuit and placed in the rubber sleeve, and is watertightly poured through the polyurethane layer. The present invention adopts a high Young's modulus, low-density structural ceramic backing plate to replace a metal backing, and through the structural design of the ceramic backing plate, the surface conductive electrode design and the bonding strength design, the weight of the face element hydrophone is effectively reduced, and the frequency response fluctuation characteristics of the hydrophone are improved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrophones, and in particular to a design method for a lightweight backing of a piezoelectric film face element hydrophone. Background Art

[0002] Large-area array is one of the development trends of sonar in the future. It can maximize the use of the installation space of the underwater platform, increase the effective aperture of the sound array, and improve the detection capability. The polymer piezoelectric film surface element hydrophone adopts a planar acoustic sensor element design, which has many incomparable advantages compared with the traditional piezoelectric ceramic point element hydrophone. First of all, the array area of ​​the surface element hydrophone can reach several times that of the traditional sonar array, and can obtain weaker target information. More importantly, the polymer piezoelectric film is light, soft, sensitive, and easy to match with the water medium. Therefore, its surface element hydrophone is vibration-resistant, impact-resistant, and has stable electroacoustic performance under high hydrostatic pressure. It has the ability to resist high wavenumber noise, and can widely replace piezoelectric ceramic point element hydrophones to improve the detection capability of sonar from the source.

[0003] The existing scheme uses a metal plate as the backing of the sensor element in the facet hydrophone, and the piezoelectric film is attached to the surface of the metal plate. The disadvantage of the prior art is mainly based on the large weight of the metal backing in the piezoelectric film facet hydrophone, which affects the adaptability of the hydrophone on the underwater platform. Therefore, the present invention proposes a design method for a lightweight backing of a piezoelectric film facet hydrophone. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a design method for a lightweight backing of a piezoelectric film panel hydrophone.

[0005] The present invention proposes the following technical solutions to achieve:

[0006] A method for designing a lightweight backing for a piezoelectric film facet hydrophone comprises a facet hydrophone, wherein the facet hydrophone comprises a sensing element, a watertight structure and a preamplifier circuit, wherein the sensing element comprises a backing plate and a piezoelectric film, wherein the upper and lower surfaces and the sides of the backing plate are coated with silver paste electrodes, wherein the piezoelectric film is bonded to the upper and lower surfaces of the backing plate, wherein the watertight structure comprises a rubber sleeve and a polyurethane layer, wherein the sensing element is connected to the preamplifier circuit and placed in the rubber sleeve, and is watertightly perfused through the polyurethane layer.

[0007] Furthermore, the backing plate is made of alumina ceramic plate material with high Young's modulus and low density.

[0008] Furthermore, the Young's modulus of the backing plate is ≥300 GPa, and its density is ≥3.8 g / cm 3 .

[0009] Furthermore, the rubber sleeve is made of vulcanized rubber material and is in a rectangular shape as a whole, and positioning holes are provided around the rubber sleeve.

[0010] Furthermore, the preamplifier circuit adopts single-ended input and output or differential input and output, and the circuit board of the preamplifier circuit is in the shape of an elongated thin plate structure.

[0011] Furthermore, the piezoelectric film is a polyvinylidene fluoride (PVDF) piezoelectric film or a copolymer of difluoroethylene and trifluoroethylene P (VDF-TrFE) piezoelectric film.

[0012] Furthermore, the piezoelectric film is bonded to the surface of the backing plate by epoxy resin, and the piezoelectric film is bonded in single or double pieces.

[0013] Furthermore, the sensing element forms a series or parallel circuit by adjusting the positive and negative directions of the upper and lower piezoelectric films.

[0014] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0015] The present invention improves the metal backing plate into a structural ceramic backing plate with high Young's modulus and low density. Conductive silver paste electrodes are printed on the upper and lower surfaces and sides of the ceramic plate, and a certain roughness is maintained. Then, a single or double piece of piezoelectric film is bonded to the surface of the ceramic plate. Through reasonable selection of backing materials, structural design, electrode layer design, etc., the overall weight of the surface element hydrophone is lower and has better frequency response characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the panel hydrophone of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the rubber sleeve of the present invention;

[0018] Figure 3 Schematic diagram of the electrodes of the sensing element of the present invention.

[0019] The following are marked in the figure:

[0020] 1- preamplifier circuit; 2- rubber sleeve; 3- piezoelectric film; 4- backing plate. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. Based on the embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Combined with Figure 1-3 As shown, a design method for a lightweight backing of a piezoelectric film surface element hydrophone includes a surface element hydrophone, the surface element hydrophone includes a sensor element, a watertight structure and a preamplifier circuit 1, the sensor element includes a backing plate 4 and a piezoelectric film 3, the upper and lower surfaces and side surfaces of the backing plate 4 are coated with silver paste electrodes, and the surface roughness Ra ≥ 0.8, the piezoelectric film 3 is bonded to the upper and lower surfaces of the backing plate 4, the watertight structure includes a rubber sleeve 2 and a polyurethane layer, the sensor element is connected to the preamplifier circuit 1 and placed in the rubber sleeve 2, and is watertightly poured through the polyurethane layer.

[0023] Specifically, the backing plate 4 is made of alumina ceramic plate material with high Young's modulus and low density, and can also be made of aluminum nitride ceramic plate or high-strength rock plate.

[0024] Specifically, the Young's modulus of the backing plate 4 is ≥300 GPa, and its density is ≥3.8 g / cm 3 The length of the backing plate 4 can be set to 78 mm, the width to 50 mm, and the thickness to 4 mm. The backing plate 4 has a stable structure and effectively reduces the overall weight of the hydrophone.

[0025] Specifically, the rubber sleeve 2 is made of vulcanized rubber material and is in the shape of a rectangular parallelepiped. Positioning holes are provided around the rubber sleeve 2 for fixing the circuit board where the sensor element and the preamplifier circuit 1 are located. The overall length of the rubber sleeve 2 can be set to 145 mm, the width to 98 mm, and the height to 33 mm.

[0026] Specifically, the preamplifier circuit 1 adopts single-ended input and output or differential input and output, and the circuit board of the preamplifier circuit 1 is in the shape of an elongated thin plate structure.

[0027] Specifically, the piezoelectric film 3 is a polyvinylidene fluoride (PVDF) piezoelectric film or a copolymer of difluoroethylene and trifluoroethylene P (VDF-TrFE) piezoelectric film, and the length of the piezoelectric film 3 is set to 78 mm and the width is set to 50 mm.

[0028] Specifically, the piezoelectric film 3 is bonded to the surface of the backing plate 4 by epoxy resin, and the number of piezoelectric films 3 bonded is single or double. The sensor element forms a series or parallel circuit by adjusting the positive and negative directions of the upper and lower piezoelectric films 3, which is convenient for leading to the input end of the preamplifier circuit 1 to amplify the signal and output it.

[0029] The present invention effectively reduces the weight of the surface element hydrophone based on the piezoelectric film 3 while ensuring that the sensing performance of the hydrophone is not lost, and improves the frequency response fluctuation characteristics of the hydrophone. The bonding strength of the piezoelectric film 3 on the backing plate 4 of the aluminum oxide material is also effectively improved.

[0030] The above are only preferred implementations of the present invention, but the protection scope of the present invention is not limited thereto, and any modification and replacement based on the technical solutions and inventive concepts provided by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for designing a lightweight backing for a piezoelectric membrane surface element hydrophone, characterized in that: The surface element hydrophone comprises a sensor element, a watertight structure and a preamplifier circuit (1), the sensor element comprises a backing plate (4) and a piezoelectric film (3), the upper and lower surfaces and the side surfaces of the backing plate (4) are coated with silver paste electrodes, the piezoelectric film (3) is bonded to the upper and lower surfaces of the backing plate (4), the watertight structure comprises a rubber sleeve (2) and a polyurethane layer, the sensor element is connected to the preamplifier circuit (1) and placed in the rubber sleeve (2), and is watertightly perfused through the polyurethane layer; The backing plate (4) has a Young's modulus of ≥300 GPa and a density of ≥3.8 g / cm 3 It is made of alumina ceramic plate material.

2. The method for designing a lightweight backing for a piezoelectric film panel hydrophone according to claim 1, characterized in that: The rubber sleeve (2) is made of vulcanized rubber material and is in the shape of a rectangular parallelepiped as a whole, and positioning holes are provided around the rubber sleeve (2).

3. The method for designing a lightweight backing for a piezoelectric membrane panel hydrophone according to claim 1, characterized in that: The preamplifier circuit (1) adopts single-ended input and output or differential input and output, and the circuit board of the preamplifier circuit (1) is in the shape of a slender thin plate structure.

4. The method for designing a lightweight backing for a piezoelectric film panel hydrophone according to claim 1, characterized in that: The piezoelectric film (3) is a polyvinylidene fluoride (PVDF) piezoelectric film or a vinyl difluoride and trifluoride copolymer P (VDF-TrFE) piezoelectric film.

5. The method for designing a lightweight backing for a piezoelectric film panel hydrophone according to claim 1, characterized in that: The piezoelectric film (3) is bonded to the surface of the backing plate (4) by epoxy resin, and the number of bonded piezoelectric films (3) is one or two.

6. The method for designing a lightweight backing for a piezoelectric film panel hydrophone according to claim 1, characterized in that: The sensing element forms a series or parallel circuit by adjusting the positive and negative directions of the upper and lower piezoelectric films (3).

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