Super-multichannel PMUT array element two-dimensional array structure and transducer

Abstract

The invention provides a super multi-channel PMUT array element two-dimensional array structure and a transducer. The super multi-channel PMUT array element two-dimensional arraying structure comprises a PMUT array element, an integrated amplifier, a PCB, a flexible flat cable, a flat cable plug, a backing and a shell. The shell is provided with a bottom plate; the PMUT array elements are uniformly arranged on the PCB, the PMUT array elements are provided with output wires, and the output wires are connected with electrodes of the PCB; integrated amplifiers are arranged on the back face of the PCB, each PMUT array element corresponds to one integrated amplifier, output signals of the integrated amplifiers are connected to a flexible flat cable, the tail end of the flexible flat cable is connected to a flat cable plug, and the flat cable plug penetrates through the bottom plate and extends to the outer side of the bottom plate. According to the invention, the flexible flat cable and the flat cable plug are designed, and the concentration of a plurality of array element signal lines is realized in the two-dimensional array structure, so that the connection points of the two-dimensional array structure and an external rear-end circuit are greatly reduced, the butt joint difficulty is greatly reduced, and the signal lead-out wire problem of the multi-channel receiving array element is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater acoustic transducers, and in particular, to a two-dimensional array and sealing structure of ultra-multi-channel PMUT array elements, and in particular, to a vortex transducer array structure and array, and in particular, to an ultra-multi-channel PMUT array element two-dimensional array structure and transducer. Background Art

[0002] Three-dimensional imaging sonar can perform high-speed imaging of underwater stationary or moving targets and provide multi-angle observation perspectives. It has the characteristics of high image refresh rate, rich feature information, and tolerance to carrier motion. Therefore, it has broad application prospects in many military and civilian fields such as preset / mine target identification, underwater vehicle obstacle avoidance, marine engineering implementation, and marine scientific research.

[0003] The planar receiving two-dimensional array (i.e., two-dimensional array structure) is an indispensable structure in three-dimensional imaging sonar technology. The planar receiving two-dimensional array is designed with multi-channel array elements in the horizontal and vertical directions. Each array element independently leads out a pair of signal lines, and each signal line is independently connected to the external back-end circuit.

[0004] In a two-dimensional planar receiving array, the number of array elements is N*N (N is generally greater than 30), and both the horizontal and vertical directions are set to N, and the total number of channels is usually greater than 1000. Therefore, the number of interfaces used to connect to the external back-end circuit (i.e., the end interfaces of the above-mentioned signal lines) is also very large. When installing the two-dimensional planar receiving array, each signal line needs to be connected to the external back-end circuit one by one. In summary, the complicated process of connecting the signal lead-out line to the back-end circuit is the main defect of the two-dimensional planar receiving array.

[0005] In addition, in traditional planar receiving two-dimensional arrays, the commonly used array elements are piezoelectric ceramic array elements, but traditional piezoelectric ceramic units are large in size, heavy in weight, and have the defect of being difficult to control in consistency. Summary of the invention

[0006] In view of the defects in the prior art, an object of the present invention is to provide a super multi-channel PMUT array element two-dimensional array structure and a transducer.

[0007] According to the present invention, a super multi-channel PMUT array element two-dimensional array structure includes PMUT array elements, an integrated amplifier, a PCB board, a flexible cable, a cable plug, a backing and a shell; the shell has a bottom plate;

[0008] The PMUT array elements are evenly arranged on the PCB board, all vibration surfaces are in the same plane, and all PMUT array elements are arranged in the same direction;

[0009] The PMUT array element has an output wire, and the output wire is connected to the electrode of the PCB board;

[0010] An integrated amplifier is set on the back of the PCB board. Each PMUT array element corresponds to an integrated amplifier, and the output signal of the integrated amplifier is connected to the flexible cable;

[0011] The lower layer of the PCB board is provided with a backing; the backing is mounted on the bottom plate;

[0012] The end of the flexible cable is connected to the cable plug, and the cable plug passes through the bottom plate and extends to the outside of the bottom plate.

[0013] Preferably, the PCB board is a whole board;

[0014] Or, it is composed of multiple plates spliced ​​together, with uniform spacing between each plate, meeting the requirement of half-wavelength arrangement of array elements.

[0015] Preferably, the vibration surface of the PMUT array element and the inner wall of the shell are made watertight by sound-transmitting polyurethane material.

[0016] Preferably, the number of PMUT array elements is N*N, where N is greater than or equal to 5.

[0017] Preferably, it also includes a heat-conducting layer, and the backing (6) is bonded with a heat-conducting layer on the side close to the integrated amplifier for heat dissipation.

[0018] Preferably, the length and width of the backing are consistent with the PCB board, and the thickness of the backing is greater than 10 times the wavelength corresponding to the operating frequency.

[0019] Preferably, the PCB board is a multi-layer board structure, each layer is provided with PMUT array elements, and an integrated amplifier is provided on the back of each layer; the PMUT array elements on adjacent layers are connected through array element signal transmission lines arranged between the boards, and the integrated amplifier on each layer is connected to the flexible cable through the gap between adjacent boards.

[0020] Preferably, the PMUT array element is made of ALN, ScALN, PZT or ZnO piezoelectric material.

[0021] Preferably, the bottom plate is a metal bottom plate.

[0022] According to a transducer provided by the present invention, the ultra-multi-channel PMUT array element two-dimensional array structure is adopted;

[0023] The cable plug passes through the backing and the bottom plate and enters the transducer cabin. The portion of the cable plug entering the cabin is left with a length to facilitate insertion into the back-end circuit.

[0024] The cable plugs are arranged on the inner walls around the cabin.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention designs a flexible flat cable and a flat cable plug. After the signal lines of different PMUT array elements pass through the integrated amplifier circuit, they are concentrated at the flexible flat cable and then connected to the outside world through the flat cable plug. Since the concentration of multiple array element signal lines is achieved in the two-dimensional array structure (i.e., the planar receiving two-dimensional array), the connection points between the two-dimensional array structure and the external back-end circuit are greatly reduced, the difficulty of docking is greatly reduced, and the problem of signal lead-out lines of multi-channel receiving array elements is solved.

[0027] 2. The present invention replaces the traditional piezoelectric ceramic array elements with PMUT array elements and applies them to underwater three-dimensional imaging sonar transducers. It can solve the problems of complex signal lead-out lines and low array element consistency of traditional two-dimensional receiving transducer arrays, and can greatly reduce the volume and weight of the planar receiving two-dimensional array, reduce manufacturing costs, and improve imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0029] Figure 1 It is a schematic diagram of the local structure of the present invention;

[0030] Figure 2 is a layout diagram of an integrated amplifier corresponding to the PMUT array element of the present invention;

[0031] Figure 3 It is a schematic diagram of the exploded view structure of the present invention;

[0032] Figure 4 A side cross-sectional view of the present invention.

[0033] The figure shows:

[0034] DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0036] The present invention provides a two-dimensional array structure of ultra-multi-channel PMUT array elements, such as Figure 1-4 As shown, it includes a PMUT array element 1, an integrated amplifier 5, a PCB board 2, a flexible cable 3, a cable plug 4, a backing 6 and a shell 7; the shell 7 has a bottom plate 10; the PMUT array element 1 has a certain pressure resistance, and the hydrostatic pressure resistance is generally required to be greater than 0.1MPa;

[0037] The PMUT array elements 1 are evenly arranged on the PCB board, all vibration surfaces are in the same plane, all PMUT array elements are arranged in the same direction, the horizontal and vertical spacing is generally half the wavelength of the operating frequency, and the number of array elements in the horizontal direction is equal to that in the vertical direction.

[0038] The PMUT array element 1 has two gold-plated thin wires as output wires, and the output wires are connected to the electrodes of the PCB board 2; specifically, the wires are bonded to the electrode pads of the PCB board by glue dispensing.

[0039] An integrated amplifier 5 is arranged on the back of the PCB board 2, and each PMUT array element 1 corresponds to an integrated amplifier 5. The output signal of the integrated amplifier 5 is connected to the flexible flat cable 3. Specifically, the integrated amplifier 5 has two connection points, a positive pole and a negative pole, and the two connection points are respectively connected to the flexible flat cable 3 through a wire; the power lines in the flexible flat cable 3 are placed on the two sides of the cable, and the outer layer of the flexible flat cable is a shielding layer.

[0040] The lower layer of the PCB board 2 is provided with a backing 6; the backing is made of epoxy resin and oxide powder, and has a certain structural strength. The backing 6 is bonded to the bottom plate 10;

[0041] The end of the flexible flat cable 3 is connected to the flat cable plug 4 , and the flat cable plug 4 passes through the bottom plate 10 and extends to the outside of the bottom plate 10 .

[0042] The PCB board 2 is a whole board; or, it is composed of multiple boards spliced ​​together, and the spacing between each board is uniform, which meets the requirement of half-wavelength array of array elements.

[0043] The number of PMUT array elements 1 is N*N, where N is greater than or equal to 5. The "super-many" in the super-multi-channel PMUT array element two-dimensional array structure refers to a large number of array elements 1, such as the N*N mentioned above, where N is greater than or equal to 5. Specifically, the size of a single PMUT array element 1 is 3.5*3.5mm, with a horizontal and vertical spacing of 5mm, and the number of array elements in the horizontal and vertical directions is equal, which is 48*48 elements. That is, each of the 48*48-element PMUT array elements independently leads out a pair of differential signal lines, and after passing through the integrated amplifier circuit, the small analog signal of the array element is amplified, output to the flexible cable end, and enters the back-end circuit. In a preferred example, Figure 2 As shown, the number of the flexible flat cables 3 is 16, because when the number of PMUT array elements is too large, a single flexible flat cable 3 is insufficient to provide connection for such a large number of PMUT array elements.

[0044] The ultra-multi-channel PMUT array element two-dimensional array structure further includes a heat-conducting layer 8, and the backing 6 is bonded to a side close to the integrated amplifier 5, and the heat-conducting layer 8 is used for heat dissipation.

[0045] The backing is configured by mixing materials such as epoxy resin according to the size of the PCB board. Specifically, the length and width of the backing 6 are consistent with the PCB board 2, and the thickness of the backing is greater than 10 times the wavelength corresponding to the working frequency. In a preferred example, the size of the backing 6 is 300*300*30.

[0046] In a preferred example, the vibration surface of the PMUT array element and the inner wall of the housing 7 are watertight by sound-transmitting polyurethane material. That is to say, the super multi-channel PMUT array element two-dimensional array structure further includes a sound-transmitting layer 9, which is arranged on the housing 7 and is used for sealing and waterproofing the super multi-channel PMUT array element two-dimensional array structure.

[0047] In a preferred example, the PCB board 2 is a multi-layer board structure, preferably a 6-layer board structure. Each layer is provided with a PMUT array element 1, and an integrated amplifier 5 is provided on the back of each layer. The PMUT array elements 1 on adjacent layers are connected through array element signal transmission lines provided between the boards, and the integrated amplifier 5 on each layer is connected to the flexible flat cable 3 through the gap between the adjacent boards.

[0048] The PMUT array element 1 is a piezoelectric micromechanical ultrasonic array element, which has the advantages of small size, easy integration, and arrayability. The PMUT array element can generate ultrasonic waves, and the PMUT array element 1 is a piezoelectric material such as ALN, ScALN, PZT or ZnO, preferably, a ScALN piezoelectric material. The bottom plate 10 is a metal bottom plate.

[0049] Replacing traditional piezoelectric ceramic array elements with PMUT array elements and applying them to underwater three-dimensional imaging sonar transducers can solve the problems of complex signal lead-out lines and low array element consistency of traditional two-dimensional receiving transducer arrays. It can also significantly reduce the volume and weight of planar receiving two-dimensional arrays, reduce manufacturing costs, and improve imaging quality.

[0050] The present invention also provides a transducer, which adopts the ultra-multi-channel PMUT array element two-dimensional array structure. The cable plug 4 passes through the backing 6 and the bottom plate 10 and enters the transducer cabin. The cable plug 4 is arranged on the inner wall around the cabin. The cable plug 4 passes through the metal waist-shaped hole. The portion of the cable plug 4 entering the cabin is left with a length to facilitate insertion into the back-end circuit. The waist-shaped hole and the like are watertight by sound-transmitting polyurethane material.

[0051] The present invention designs an integrated amplifier circuit, which can minimize the influence of wires on analog small signals and reduce the noise of analog circuits; the present invention designs a soft flat cable, which completes the signal extraction of the receiving array element through the edge outlet groove (i.e., the groove on the bottom plate 10 for the flat cable plug 4 to pass through), and has a reasonable structure and is suitable for sonar engineering. The present invention is designed with a heat-conducting layer, the purpose of which is to dissipate the heat generated by the amplifier circuit in time when the receiving array is working, so as to improve the stability and reliability of the receiving array.

[0052] In summary, by adopting the above-mentioned technical solution, the manufacturing difficulties of the three-dimensional multi-beam imaging sonar transducer array can be reduced. The present invention has a simple structure and few process steps. Compared with the prior art, the advantages of the present invention are: 1. It greatly reduces the difficulty of connecting the lead wires of the two-dimensional array structure in the transducer; it solves the problem of signal lead wires of multi-channel receiving array elements; 2. It can adapt to high-frequency transceiver transducer arrays in different working frequency bands, and the array elements have high consistency; 3. It improves the stability and reliability of the receiving array. The present invention optimizes and updates the two-dimensional receiving array of the three-dimensional imaging sonar, and reduces the manufacturing difficulty of the three-dimensional imaging sonar receiving array.

[0053] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0054] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A two-dimensional array structure of ultra-multi-channel PMUT array elements, characterized in that: It comprises a PMUT array element (1), an integrated amplifier (5), a PCB board (2), a flexible flat cable (3), a flat cable plug (4), a backing (6) and a housing (7); the housing (7) has a bottom plate (10); The PMUT array elements (1) are evenly arranged on the PCB board, all vibration surfaces are in the same plane, and all PMUT array elements are arranged in the same direction; The PMUT array element (1) has an output wire, and the output wire is connected to the electrode of the PCB board (2); An integrated amplifier (5) is arranged on the back of the PCB board (2), each PMUT array element (1) corresponds to an integrated amplifier (5), and an output signal of the integrated amplifier (5) is connected to the flexible flat cable (3); The lower layer of the PCB board (2) is provided with a backing (6); the backing (6) is mounted on the bottom plate (10); The end of the flexible flat cable (3) is connected to a flat cable plug (4), and the flat cable plug (4) passes through the bottom plate (10) and extends to the outside of the bottom plate (10).

2. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The PCB board (2) is a whole board; Or, it is composed of multiple plates spliced ​​together, with uniform spacing between each plate, meeting the requirement of half-wavelength arrangement of array elements.

3. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The vibration surface of the PMUT array element and the inner wall of the housing (7) are made watertight by using a sound-transmitting polyurethane material.

4. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The number of PMUT array elements (1) is N*N, where N is greater than or equal to 5.

5. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: It also comprises a heat-conducting layer (8), and the backing (6) is bonded to a side close to the integrated amplifier (5) to dissipate heat.

6. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The length and width of the backing (6) are consistent with those of the PCB board (2), and the thickness of the backing is greater than 10 times the wavelength corresponding to the working frequency.

7. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The PCB board (2) is a multi-layer board structure, each layer board is provided with a PMUT array element (1), and each layer board is provided with an integrated amplifier (5) on the back side; the PMUT array elements (1) on adjacent layers are connected via array element signal transmission lines provided between the boards, and the integrated amplifier (5) on each layer board is connected to the flexible flat cable (3) via the gap between adjacent boards.

8. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The PMUT array element (1) is made of ALN, ScALN, PZT or ZnO piezoelectric material.

9. The ultra-multi-channel PMUT array element two-dimensional array structure according to claim 1, characterized in that: The bottom plate (10) is a metal bottom plate.

10. A transducer, characterized in that: Adopting the ultra-multi-channel PMUT array element two-dimensional array structure described in any one of claims 1 to 9; The cable plug (4) passes through the backing (6) and the bottom plate (10) and then enters the transducer compartment. The portion of the cable plug (4) entering the compartment has a certain length to facilitate insertion into the rear-end circuit. The cable plugs (4) are arranged on the inner walls around the cabin.

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