High sensitivity receiving element and arraying method of high frequency sonar receiving transducer

Abstract

This invention provides a high-sensitivity receiving array element and its arrangement method for a high-frequency sonar receiving transducer, relating to the field of underwater acoustic transducer technology. The array element includes an array element with sound-insulating and decoupling material filling the spaces between adjacent elements. Each array element comprises a piezoelectric ceramic, an epoxy matching layer, epoxy resin, a copper mesh, copper foil, and copper wire. Epoxy resin fills the spaces between adjacent piezoelectric ceramics. One end of each piezoelectric ceramic is connected to the copper mesh, and the other end is connected to the epoxy matching layer. Copper foil is provided on both the upper and lower surfaces of the epoxy matching layer, and the copper foils are connected by copper wire. This invention features a simple structure and fewer process steps, improves the sensitivity level within the operating frequency band of the receiving array element, and increases the operating bandwidth of the high-frequency receiving array element. It solves the signal lead-out problem of multi-channel receiving array elements and simplifies the wire bonding process. It can adapt to multi-channel high-frequency receiving transducer arrays in different operating frequency bands and has strong adaptability to transducer array configurations.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic transducer technology, specifically to a high-sensitivity receiving array element and arraying method for a high-frequency sonar receiving transducer. Background Technology

[0002] With the increasing development and research activities of humankind regarding marine resources and the environment, high-frequency multibeam sonar has become one of the most important marine survey and exploration instruments in marine scientific research, seabed resource development, and marine engineering construction both domestically and internationally. The multi-channel high-frequency receiving transducer array, as a crucial component of the underwater wet end of the receiving system, performs narrow-beam reception of echoes from the seabed or targets. By processing the received signals, relevant information about the seabed or targets is obtained. The receiving array element is the key component in converting underwater acoustic pressure signals into electrical signals; the sensitivity of the array element determines the minimum detectable signal size.

[0003] Multi-channel high-frequency receiving transducer arrays generally require very sharp beam directivity to achieve high resolution of fine targets. High-frequency receiving transducer arrays typically have hundreds or even thousands of channels, with very small element sizes and low capacitance. Their receiving sensitivity is greatly affected by factors such as materials, thickness, and cable, resulting in relatively low sensitivity values. By adding a sensitivity-enhancing structure to the 1-3 piezoelectric composite material of the receiving type, and applying a certain pressure to the piezoelectric composite material, the receiving sensitivity of the receiving unit can be improved.

[0004] Current research on sensitive matching layer technology for underwater acoustic high-frequency receiver transducers is limited in relevant literature, with most studies focusing on its use to increase bandwidth and extend the operating frequency range. This invention proposes a receiver array element structure and system employing a sensitive matching layer, which can both increase transducer sensitivity and extend bandwidth. No similar technology or method has been found in existing documents or literature. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high-sensitivity receiving array element and its arrangement method for a high-frequency sonar receiving transducer.

[0006] According to the present invention, a high-sensitivity receiving array element of a high-frequency sonar receiving transducer includes an array element, wherein a sound-insulating and decoupling material is filled between two adjacent array elements.

[0007] The array element includes a piezoelectric ceramic, an epoxy matching layer, epoxy resin, a copper mesh, copper foil, and copper wire. Epoxy resin is filled between two adjacent piezoelectric ceramics. One end of the piezoelectric ceramic is connected to the copper mesh, and the other end of the piezoelectric ceramic is connected to the epoxy matching layer. Copper foil is provided on both the upper and lower surfaces of the epoxy matching layer, and the copper foils are connected to each other by copper wire.

[0008] Preferably, the positive and negative conductors of the array element are led out through the copper foil at the top and the copper mesh at the bottom.

[0009] Preferably, along the length of the array element, the piezoelectric ceramic is cut into multiple square pillars, and epoxy resin is filled into two adjacent square pillars.

[0010] Preferably, the gap width between two adjacent square pillars is greater than or equal to the width of the piezoelectric ceramic.

[0011] Preferably, the thickness of both the copper mesh and the copper foil is ≤0.1mm.

[0012] Preferably, the diameter of the copper wire is less than 1 / 15 of the wavelength corresponding to the operating frequency of the array element.

[0013] Preferably, the copper wire is located above the gap between the square pillars.

[0014] Preferably, the piezoelectric ceramic is rectangular strip-shaped and polarized in the height direction.

[0015] Preferably, the height of the sound insulation and decoupling material is flush with the epoxy matching layer.

[0016] This invention also provides a method for arranging high-sensitivity receiving array elements of a high-frequency sonar receiving transducer, comprising the following steps:

[0017] S1: Based on the operating frequency and directivity requirements, the array element adopts rectangular strip-shaped piezoelectric ceramics, and the piezoelectric ceramics are polarized in the height direction.

[0018] S2: Along the length of the array element, the piezoelectric ceramic is divided into multiple square pillars by a cutting machine, and epoxy resin is filled into the gap between two adjacent square pillars.

[0019] S3: Attach copper mesh to the bottom of the square column using conductive adhesive to connect multiple square columns together;

[0020] S4: An epoxy matching layer is bonded to the upper part of the square column, and copper foil is applied to the upper and lower surfaces of the epoxy matching layer, with the copper foil connected in the middle by copper wire.

[0021] S5: The positive and negative wires of the array element are led out by soldering the top copper foil and the bottom copper mesh;

[0022] S6: Sound insulation and decoupling material is poured between array elements to form a multi-channel high-sensitivity receiving array element.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention has a simple structure and fewer process steps, improves the sensitivity level of the receiving array element within the operating frequency band, and increases the operating bandwidth of the high-frequency receiving array element; it solves the problem of signal lead-out lines for multi-channel receiving array elements and simplifies the wire bonding process; it can adapt to multi-channel high-frequency receiving transducer arrays in different operating frequency bands and has strong adaptability to transducer array types. Attached Figure Description

[0025] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the array element structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the multi-channel high-sensitivity receiving array element of the present invention;

[0028] Figure 3 This is the array element receiving sensitivity curve of the present invention.

[0029] Numbering on the map:

[0030] 1. Piezoelectric ceramic; 2. Epoxy matching layer; 3. Epoxy resin; 4. Copper mesh; 5. Copper foil; 6. Copper wire; 7. Sound insulation and decoupling material. Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0032] Example 1

[0033] According to the present invention, a high-sensitivity receiving array element of a high-frequency sonar receiving transducer is provided, such as... Figure 2 As shown, it includes array elements, with sound-insulating and decoupling material 7 filling the space between two adjacent array elements;

[0034] like Figure 1As shown, the array element includes a piezoelectric ceramic 1, an epoxy matching layer 2, epoxy resin 3, a copper mesh 4, a copper foil 5, and copper wires 6. The positive and negative conductors of the array element are led out through the copper foil 5 at the top and the copper mesh 4 at the bottom. The piezoelectric ceramic 1 is rectangular in shape and polarized in the height direction; the width of the piezoelectric ceramic 1 is smaller than its height, and its length is generally more than three times its thickness. Along the length of the array element, the piezoelectric ceramic 1 is cut into multiple square pillars, and epoxy resin 3 is filled into adjacent square pillars. The gap width between adjacent square pillars is greater than or equal to the width of the piezoelectric ceramic 1. Epoxy resin 3 is filled between adjacent piezoelectric ceramics 1. The bottom of the square pillars is bonded to the copper mesh 4 with conductive adhesive, and the top of the square pillars is bonded to the epoxy matching layer 2. The height of the sound insulation and decoupling material 7 is flush with that of the epoxy matching layer 2. The epoxy matching layer 2 has copper foil 5 on both the top and bottom surfaces. The copper foil 5 is connected by copper wire 6. The thickness of both the copper mesh 4 and the copper foil 5 is ≤0.1mm. The copper wire 6 is located above the gap between the square pillars. The diameter of the copper wire 6 is <1 / 15 of the wavelength corresponding to the working frequency of the array element.

[0035] Based on the operating frequency and directional angle determined in the overall demonstration of the high-frequency sonar system, the size of the array element was determined through finite element simulation calculations. The receiving sensitivity and directivity of the array element were calculated, and then the material and size of the elongated piezoelectric ceramic 1 were optimized and selected. The piezoelectric ceramic 1 was purchased from the manufacturer. Alternatively, the piezoelectric ceramic 1 of the required size can be cut. In this embodiment of the invention, the resonant frequency of the array element is 500kHz, and the vertical directivity angle of the array element is 20°. The determined PZT5 type piezoelectric ceramic 1 is bonded to the substrate and then transversely cut. The cutting blade thickness of this invention is 0.4mm, and the center distance of the cut is 0.8mm. After cutting, epoxy resin 3 is poured into the gap, and then defoaming treatment is performed. Excess epoxy resin 3 is cleaned, and the surface of the piezoelectric ceramic 1 is cleaned.

[0036] The copper mesh 4 is cleaned by immersing it in hydrochloric acid to completely remove the oxide layer on its surface, and then placed in a drying oven for later use. In this embodiment of the invention, the copper mesh 4 has a thickness of 0.1 mm and a mesh count of less than 200. A layer of conductive silver paste is uniformly coated onto the bottom of the treated piezoelectric ceramic 1, and then the copper mesh 4 is adhered to the bottom of the piezoelectric ceramic 1.

[0037] A specialized mold is fabricated, and a layer of copper foil 5 is laid on the bottom and top of the mold. Copper wires 6 are soldered onto the upper and lower layers of copper foil 5 to connect the upper and lower surfaces of the matching layer. Then, the epoxy matching layer 2 is poured into the mold. In this embodiment, the thickness of the copper foil 5 is 0.07 mm, and the diameter of the copper wires 6 is 0.01 mm.

[0038] The epoxy matching layer 2 of the assembled copper foil 5 is bonded to the surface of the piezoelectric ceramic 1. The copper wire 6 used to connect the upper and lower surfaces should be placed above the cut slit. After curing, the positive and negative terminals of the signal lines are welded to the upper and lower surfaces of the composite structure. Then, watertight sealing is performed according to the potting requirements of the underwater acoustic transducer. The receiving sensitivity of the transducer array elements is tested in a water tank. Test data are shown below. Figure 3 .

[0039] Example 2

[0040] The present invention also provides a method for arranging high-sensitivity receiving array elements of the high-frequency sonar receiving transducer in Embodiment 1, comprising the following steps:

[0041] S1: According to the operating frequency and directivity requirements, the array element adopts a rectangular strip-shaped piezoelectric ceramic 1, and the piezoelectric ceramic 1 is highly directionally polarized.

[0042] S2: Along the length of the array element, the piezoelectric ceramic 1 is divided into multiple square pillars by a cutting machine, and epoxy resin 3 is filled into the gap between two adjacent square pillars.

[0043] S3: Attach the copper mesh 4 to the bottom of the square column with conductive adhesive to connect multiple square columns 4 together;

[0044] S4: The upper part of the square column is bonded with epoxy matching layer 2, and copper foil 5 is applied to the upper and lower surfaces of epoxy matching layer 2. The copper foil 5 is connected in the middle by copper wire 6.

[0045] S5: The positive and negative wires of the array element are led out by soldering the uppermost copper foil 5 and the lowermost copper mesh 4;

[0046] S6: Sound insulation and decoupling material 7 is poured between array elements to form a multi-channel high-sensitivity receiving array element.

[0047] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0048] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A high-sensitivity receiving array element of a high-frequency sonar receiving transducer, characterized in that, Including array elements, with sound insulation and decoupling material filling the space between two adjacent array elements (7). The array element includes a piezoelectric ceramic (1), an epoxy matching layer (2), epoxy resin (3), a copper mesh (4), copper foil (5), and copper wire (6). The epoxy resin (3) fills the space between two adjacent piezoelectric ceramics (1). One end of the piezoelectric ceramic (1) is connected to the copper mesh (4), and the other end of the piezoelectric ceramic (1) is connected to the epoxy matching layer (2). The epoxy matching layer (2) has copper foil (5) on its upper and lower surfaces, and the copper foils (5) are connected to each other by the copper wire (6). Along the length of the array element, the piezoelectric ceramic (1) is cut into multiple square pillars, and the epoxy resin (3) is filled into two adjacent square pillars.

2. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The positive and negative conductors of the array element are led out through the copper foil (5) at the top and the copper mesh (4) at the bottom.

3. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The width of the gap between two adjacent square pillars is greater than or equal to the width of the piezoelectric ceramic (1).

4. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The thickness of both the copper mesh (4) and the copper foil (5) is ≤0.1mm.

5. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The diameter of the copper wire (6) is less than 1 / 15 of the wavelength corresponding to the operating frequency of the array element.

6. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The copper wire (6) is located above the gap between the square pillars.

7. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The piezoelectric ceramic (1) is rectangular strip-shaped and is highly polarized.

8. The high-sensitivity receiving array element of the high-frequency sonar receiving transducer according to claim 1, characterized in that, The height of the sound insulation decoupling material (7) is flush with that of the epoxy matching layer (2).

9. A method for arranging high-sensitivity receiving array elements of a high-frequency sonar receiving transducer according to any one of claims 1-8, characterized in that, Includes the following steps: S1: According to the operating frequency and directivity requirements, the array element adopts the rectangular strip-shaped piezoelectric ceramic (1), and the piezoelectric ceramic (1) is highly directionally polarized; S2: In the length direction of the array element, the piezoelectric ceramic (1) is divided into multiple square pillars by a cutting machine, and the epoxy resin (3) is filled in the gap between two adjacent square pillars. S3: The bottom of the square column is bonded to the copper mesh (4) with conductive adhesive, so that multiple square columns are connected together. S4: The epoxy matching layer (2) is bonded to the upper part of the square column, and the copper foil (5) is applied to the upper and lower surfaces of the epoxy matching layer (2), and the copper foil (5) is connected in the middle by the copper wire (6). S5: The positive and negative conductors of the array element are led out by welding the uppermost copper foil (5) and the lowermost copper mesh (4); S6: The sound insulation and decoupling material (7) is poured between the array elements to form a multi-channel high-sensitivity receiving array element.

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