A deep-sea-oriented MEMS hydrophone packaging structure

Abstract

The application relates to a deep-sea-oriented MEMS hydrophone packaging structure which comprises a packaging shell and a one-way valve, the inside of the packaging shell is provided with a mounting cavity and a pressure relief cavity, and is further provided with a through hole communicating the mounting cavity and the pressure relief cavity, the mounting cavity is filled with an insulating liquid medium, the pressure relief cavity is filled with a gaseous medium, and the one-way valve is installed in the through hole; when the pressure in the mounting cavity is greater than the pressure in the pressure relief cavity, the liquid medium in the mounting cavity flows into the pressure relief cavity through the one-way valve; the MEMS hydrophone is installed in the mounting cavity of the packaging shell; when applied to a deep-sea high-pressure environment, a larger acting force is applied to the packaging shell; due to the incompressible characteristics of the liquid medium, the pressure in the mounting cavity is greater than the pressure in the pressure relief cavity; under the action of the one-way valve, the liquid medium in the mounting cavity automatically flows into the pressure relief cavity, thereby reducing the pressure in the mounting cavity and completing the release of the excess static stress on the MEMS hydrophone; and the packaging structure improves the pressure resistance of the piezoelectric film type MEMS hydrophone.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrophone, in particular to a MEMS hydrophone packaging structure for deep sea. BACKGROUND

[0002] The hydrophone is widely used in underwater communication, exploration, target positioning and tracking, and is an important part of sonar.

[0003] Compared with the traditional pressure-resistant packaging structure of the hydrophone, the MEMS hydrophone has higher sensitivity, smaller volume and lower power consumption, but the MEMS hydrophone is more sensitive to changes in external conditions, and its structure is more likely to be damaged and fail.

[0004] However, due to the insufficient pressure resistance and internal pressure regulation capacity of the packaging structure, the piezoelectric film inside the MEMS chip is subjected to excessive stress, making it difficult to work normally in a deep-sea high-pressure environment. SUMMARY

[0005] Therefore, it is necessary to provide a MEMS hydrophone packaging structure for deep sea, which solves the problem that the piezoelectric film inside the MEMS chip is subjected to excessive stress due to the insufficient pressure resistance and internal pressure regulation capacity of the packaging structure, making it difficult to work normally in a deep-sea high-pressure environment.

[0006] The present application provides a MEMS hydrophone packaging structure for deep sea, comprising a packaging shell and a one-way valve, the packaging shell has a mounting cavity and a pressure relief cavity inside, and further has a through hole communicating the mounting cavity and the pressure relief cavity, the mounting cavity is filled with an insulating liquid medium, the pressure relief cavity is filled with a gaseous medium, and the one-way valve is installed in the through hole, when the pressure in the mounting cavity is greater than the pressure in the pressure relief cavity, the liquid medium in the mounting cavity flows into the pressure relief cavity through the one-way valve.

[0007] Further, the packaging shell comprises a first shell, a second shell and a partition plate, the first shell and the second shell are detachably connected, the partition plate is fixedly arranged inside the second shell, the mounting cavity is formed between the partition plate and the first shell, the pressure relief cavity is formed between the partition plate and the second shell, and the through hole is located on the partition plate.

[0008] Further, the packaging shell further comprises a sealing ring, the first shell and the second shell are threadedly connected, and the sealing ring is arranged between the first shell and the second shell to seal.

[0009] Further, the packaging shell is in the shape of a capsule, and the mounting cavity and the pressure relief cavity are arranged in sequence along the length direction of the packaging shell.

[0010] Further, the MEMS hydrophone is arranged at the center position of the mounting cavity.

[0011] Further, the support assembly is located outside the package shell at one end and extends into the mounting cavity and is connected with the MEMS hydrophone so that the MEMS hydrophone is located at the center of the mounting cavity.

[0012] Further, the support assembly comprises a support tube and a connecting seat, the support tube is built in the mounting cavity, one end of the support tube extends outside the package shell, the other end of the support tube is connected with the connecting seat, the support tube and the connecting seat are formed with a slot, the integrated circuit board M in the MEMS hydrophone is embedded in the slot, the connecting seat and the integrated circuit board M are both formed with threaded holes, and the two are connected through screws.

[0013] Further, the MEMS hydrophone further comprises a MEMS chip, a pad and a signal line, the MEMS chip and the pad are both mounted on the integrated circuit board, one end of the signal line is connected with the pad, the other end of the signal line passes through the support tube to the outside of the package shell and is externally connected with a signal receiver.

[0014] Further, the support tube is threadedly connected with the package shell.

[0015] Further, the liquid medium is dimethyl silicone oil.

[0016] Compared with the prior art, the MEMS hydrophone is installed into the mounting cavity of the package shell, in the application to the deep sea high pressure environment, the force applied to the package shell is large, due to the incompressible characteristics of the liquid medium, the pressure in the mounting cavity is greater than that in the pressure relief cavity, under the action of the one-way valve, the liquid medium in the mounting cavity automatically flows into the pressure relief cavity, thereby reducing the pressure in the mounting cavity, completing the release of the excess static stress on the MEMS hydrophone, and the packaging structure improves the pressure resistance of the piezoelectric film type MEMS hydrophone. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The overall structure schematic view of the deep-sea-oriented MEMS hydrophone packaging structure provided by the embodiment of the application is shown in the figure.

[0018] Figure 2 The side view schematic view of the support structure in the deep-sea-oriented MEMS hydrophone packaging structure provided by the embodiment of the application is shown in the figure.

[0019] Figure 3 The front view sectional view of the support structure in the deep-sea-oriented MEMS hydrophone packaging structure provided by the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0020] The preferred embodiments of the application will be described in detail below with reference to the accompanying drawings, wherein the drawings constitute a part of this application and serve to explain the principles of the embodiments of the application, but are not used to limit the scope of the application.

[0021] As shown in Figure 1 The application provides a deep-sea MEMS hydrophone packaging structure, which comprises a packaging shell 100 and a one-way valve 200. The packaging shell 100 has an installation cavity 111 and a pressure relief cavity 112 in the interior, and further has a through hole 113 communicating the installation cavity 111 and the pressure relief cavity 112. The installation cavity 111 is filled with an insulating liquid medium, the pressure relief cavity 112 is filled with a gaseous medium, and the one-way valve 200 is installed in the through hole 113. When the pressure in the installation cavity 111 is greater than the pressure in the pressure relief cavity 112, the liquid medium in the installation cavity 111 flows into the pressure relief cavity 112 through the one-way valve 200.

[0022] In the implementation, the MEMS hydrophone is installed in the installation cavity 111 of the packaging shell 100. When applied to a deep-sea high-pressure environment, a greater force is applied to the packaging shell 100. Due to the incompressible characteristics of the liquid medium, the pressure in the installation cavity 111 is greater than the pressure in the pressure relief cavity 112. Under the action of the one-way valve 200, the liquid medium in the installation cavity 111 automatically flows into the pressure relief cavity 112, thereby reducing the pressure in the installation cavity 111 and completing the release of the excess static stress on the MEMS hydrophone. The packaging structure improves the pressure resistance of the piezoelectric film MEMS hydrophone.

[0023] The packaging shell 100 in the embodiment has the installation cavity 111 and the pressure relief cavity 112 in the interior, and further has the through hole 113 communicating the installation cavity 111 and the pressure relief cavity 112. The installation cavity 111 is filled with the insulating liquid medium, and the pressure relief cavity 112 is filled with the gaseous medium.

[0024] In one embodiment, the packaging shell 100 comprises a first shell 110, a second shell 120 and a partition plate 130. The first shell 110 and the second shell 120 are detachably connected. The partition plate 130 is fixedly arranged in the interior of the second shell 120. The partition plate 130 and the first shell 110 form the installation cavity 111, and the partition plate 130 and the second shell 120 form the pressure relief cavity 112.

[0025] The packaging shell 100 in the embodiment further comprises a sealing ring 140. The first shell 110 and the second shell 120 are threadedly connected. The sealing ring 140 is arranged between the first shell 110 and the second shell 120 to seal.

[0026] Of course, the first shell 110 and the second shell 120 can also be connected by flanges and the like, which are convenient to disassemble and assemble and stable in connection.

[0027] The packaging shell 100 in the embodiment is made of titanium alloy material which has high strength, corrosion resistance and good sound transmission characteristics. Of course, according to the water environment, the packaging shell 100 can also be made of corresponding materials.

[0028] In one embodiment, the encapsulation housing 100 is capsule-shaped, and the mounting cavity 111 and the pressure relief cavity 112 are sequentially arranged along the length of the encapsulation housing 100. The capsule-shaped encapsulation housing 100 can effectively avoid stress concentration.

[0029] Of course, in other embodiments, the packaging shell 100 can be cylindrical or box-shaped to achieve the inventive intent of this embodiment. Therefore, the shape of the packaging shell 100 is not limited.

[0030] In one embodiment, the MEMS hydrophone is positioned at the center of the mounting cavity 111, that is, the MEMS hydrophone is spaced apart from the inner wall of the packaging shell 100.

[0031] To enable the MEMS hydrophone to be installed at the center of the mounting cavity 111, this embodiment also includes a support component 300. One end of the support component 300 is located outside the encapsulation housing 100, and the other end of the support component 300 extends into the mounting cavity 111 and is connected to the MEMS hydrophone, so that the MEMS hydrophone is located at the center of the mounting cavity 111.

[0032] like Figures 2-3 As shown, in one embodiment, the support assembly 300 includes a support tube 310 and a connector 320. The support tube 310 is built into the mounting cavity 111. One end of the support tube 310 extends outside the package housing 100, and the other end of the support tube 310 is connected to the connector 320. The support tube 310 and the connector 320 form a slot 311. The integrated circuit board M in the MEMS hydrophone is inserted into the slot 311. Both the connector 320 and the integrated circuit board M have threaded holes 321, and the two are connected by screws.

[0033] The MEMS hydrophone also includes a MEMS chip M1, a pad M2, and a signal line. The MEMS chip M1 and the pad M2 are both mounted on the integrated circuit board M. One end of the signal line is connected to the pad M2, and the other end of the signal line passes through the support tube 310 to the outside of the package shell 100 and is connected to an external signal receiver.

[0034] It is understood that the support tube 310 is threaded to the encapsulation shell 100. Of course, in other embodiments, the support tube 310 and the encapsulation shell 100 can also be connected by means of heat fusion, etc., and there is no limitation on this.

[0035] In this embodiment, the liquid medium is dimethyl silicone oil, which has good sound transmission properties and also serves as an insulation to prevent short circuits in the chip. Of course, in other embodiments, other insulating liquids can also be used.

[0036] Example: The integrated circuit board M is fixed inside the package housing 100 by a support structure.

[0037] The packaging structure mainly comprises a capsule-shaped packaging shell 100, a one-way valve 200 and a support assembly 300, the shell is divided into three parts, as shown in the figure, two hemispherical shells and a middle cylindrical shell, the radius R of the two hemispherical shells located at the brightness of the middle cylindrical shell is 12 mm, the height H of the middle cylindrical shell is 12 mm, the thickness T is 5 mm, and the material is TC4 titanium alloy, the top of the packaging shell 100 is a combination of a hemispherical surface and a transverse plate 130, which is an integral structure, and the inside is a cavity, the transverse plate 130 has a through hole 113 in the center, and the one-way valve 200 is threadedly connected with the through hole 113; the lower part of the packaging shell 100 is a combination of a cylindrical surface and a hemispherical surface, which is also an integral structure. Figure 1

[0038] The integrated circuit board M is fixed in the packaging shell 100 through the support structure and is filled with a liquid medium with good acoustic transparency, the length L of the integrated circuit board M is 15 mm, the width B is 10 mm, the integrated circuit includes a front integrated operational amplifier, a resistor, a capacitor and a pad M2, and leaves space for integrating a MEMS chip M1 on the back.

[0039] The support structure is in the shape of "T" and is used for supporting the integrated circuit board M, the support structure is hollow, the signal line passes through the support structure, the pad M2 of the integrated circuit board M is welded inward, and the signal receiver is connected outward, and the bottom outer wall of the support structure is threaded and is threadedly connected with the bottom of the packaging shell 100.

[0040] Compared with the prior art, the MEMS hydrophone is installed into the mounting cavity 111 of the packaging shell 100, in the application to the deep-sea high-pressure environment, the force applied to the packaging shell 100 is large, due to the incompressible characteristics of the liquid medium, the pressure in the mounting cavity 111 is greater than the pressure in the pressure relief cavity 112, under the action of the one-way valve 200, the liquid medium in the mounting cavity 111 automatically flows into the pressure relief cavity 112, thereby reducing the pressure in the mounting cavity 111, completing the release of the excess static stress on the MEMS hydrophone, and the packaging structure improves the pressure resistance of the piezoelectric film type MEMS hydrophone.

[0041] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical range disclosed by the present application can be easily thought by those skilled in the art, which should be covered within the protection scope of the present application.​

Claims

1. A MEMS hydrophone packaging structure for deep-sea applications, characterized in that, include: The encapsulation housing has an internal mounting cavity and a pressure relief cavity, and also has a through hole connecting the mounting cavity and the pressure relief cavity. The mounting cavity is filled with an insulating liquid medium, and the pressure relief cavity is filled with a gaseous medium. The encapsulation shell is capsule-shaped, and the mounting cavity and the pressure relief cavity are arranged sequentially along the length of the encapsulation shell; A one-way valve is installed in the through hole. When the pressure in the mounting cavity is greater than the pressure in the pressure relief cavity, the liquid medium in the mounting cavity flows into the pressure relief cavity through the one-way valve. The MEMS hydrophone is positioned at the center of the mounting cavity.

2. The MEMS hydrophone packaging structure for deep-sea applications according to claim 1, characterized in that, The encapsulation housing includes a first housing, a second housing, and a partition. The first housing and the second housing are detachably connected. The partition is fixedly disposed inside the second housing. The partition and the first housing form the mounting cavity. The partition and the second housing form the pressure relief cavity. The through hole is located on the partition.

3. The MEMS hydrophone packaging structure for deep-sea applications according to claim 2, characterized in that, The encapsulation housing also includes a sealing ring, and the first housing and the second housing are threadedly connected. The sealing ring is disposed between the first housing and the second housing for sealing.

4. The MEMS hydrophone packaging structure for deep-sea applications according to claim 1, characterized in that, It also includes a support assembly, one end of which is located outside the package housing, and the other end of which extends into the mounting cavity and is connected to the MEMS hydrophone, so that the MEMS hydrophone is located at the center of the mounting cavity.

5. The MEMS hydrophone packaging structure for deep-sea applications according to claim 4, characterized in that, The support assembly includes a support tube and a connector. The support tube is built into the mounting cavity. One end of the support tube extends outside the package housing, and the other end of the support tube is connected to the connector. The support tube and the connector form a slot. The integrated circuit board in the MEMS hydrophone is embedded in the slot. Both the connector and the integrated circuit board have threaded holes and are connected by screws.

6. The MEMS hydrophone packaging structure for deep-sea applications according to claim 5, characterized in that, The MEMS hydrophone also includes a MEMS chip, pads, and signal lines. The MEMS chip and the pads are mounted on the integrated circuit board. One end of the signal line is connected to the pad, and the other end of the signal line passes through the support tube to the outside of the package housing and is connected to an external signal receiver.

7. The MEMS hydrophone packaging structure for deep-sea applications according to claim 5, characterized in that, The support tube is threadedly connected to the encapsulation shell.

8. The MEMS hydrophone packaging structure for deep-sea applications according to claim 1, characterized in that, The liquid medium is dimethyl silicone oil.

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