Packaging structure of micro electro mechanical system microphone

Abstract

The utility model belongs to the technical field of microphones, and particularly relates to a packaging structure of a micro electro mechanical system microphone, which comprises a substrate, an MEMS sensor chip fixedly mounted at the top of the substrate, a signal processing chip fixedly mounted on one side of the MEMS sensor chip, an inner shell arranged at the top of the substrate, a first connecting part arranged at the bottom of the inner shell, and an outer shell arranged on the outer side of the inner shell. Second connecting parts are arranged at the bottom of the shell. The sealing adjusting mechanism, the movable groove, the expansion spring, the movable sealing plate, the through hole, the connecting groove and the open groove are used in cooperation, the through hole can be conveniently opened or closed according to the temperature, the interior and the exterior of the shell are communicated, internal heat can be conveniently and rapidly conducted out, heat dissipation work is convenient, and the service life of the shell is prolonged. According to the electromagnetic shielding shell, the situation that the shell is exploded due to the fact that gas between the two shells is expanded due to heating can be prevented, after the temperature is lowered, the expansion spring shrinks to pull the movable sealing plate, the through hole can be effectively sealed, and electromagnetic shielding work can be better facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of microphones, in particular to a packaging structure of a micro-electromechanical system microphone. Background Art

[0002] Microphones manufactured based on Micro Electro Mechanical Systems (MEMS) are called MEMS microphones. They usually include a MEMS sensor chip and an Application Specific Integrated Circuit (ASIC) chip electrically connected to it. In the process of packaging the MEMS microphone, the MEMS sensor chip and the ASIC chip need to be connected to the substrate first, and then the packaging component and the substrate form a packaging shell to seal the MEMS sensor chip and the ASIC chip. Currently, the commonly used MEMS microphone packaging is a single-layer shell structure. In a strong electromagnetic field, the single-layer shell has insufficient electromagnetic shielding capability, and the MEMS microphone will be interfered by the electromagnetic signal, thereby generating noise and affecting the sound signal. If a completely enclosed double-shell structure is used, the gas between the double shells may expand due to heat, causing the shell to burst, resulting in poor shell welding and affecting the acoustic performance of the MEMS microphone.

[0003] The prior art has the following deficiencies: The prior art discloses a packaging structure, a microphone and a terminal of a micro-electromechanical system with publication number CN202121294671.5, comprising: a substrate; an inner shell, fixed on the substrate, and forming a receiving cavity with the substrate; and an outer shell, fixed on the substrate, surrounding the inner shell, and having a gap between the inner shell and the outer shell; and an adhesive layer, located between the inner shell and the substrate and between the outer shell and the substrate, wherein at least part of the outer shell and the substrate are not connected by the adhesive layer, so that there is an opening between the outer shell and the substrate, and the opening connects the gap with the external environment of the packaging structure, or, at least part of the inner shell and the substrate are not connected by the adhesive layer, so that there is an opening between the inner shell and the substrate, and the opening connects the gap with the receiving cavity.

[0004] In order to prevent the gas between the double shells from expanding due to heat and causing the shells to explode when in use, the above-mentioned device is provided with an opening at the bottom of the outer shell. However, the opening is always open, which to a certain extent is not conducive to better electromagnetic shielding, making its use relatively limited. Utility Model Content

[0005] In view of the deficiencies in the prior art, the present invention provides a packaging structure for a micro-electromechanical system microphone to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a packaging structure for a micro-electromechanical system microphone, comprising a substrate, a MEMS sensor chip fixedly mounted on the top of the substrate, a signal processing chip fixedly mounted on one side of the MEMS sensor chip, an inner shell provided on the top of the substrate, a first connecting portion provided on the bottom of the inner shell, an outer shell provided on the outside of the inner shell, a second connecting portion provided on the bottom of the outer shell, and a sealing adjustment mechanism provided on the inner wall of the outer shell.

[0007] As a preferred technical solution of the present invention, the MEMS sensor chip and the signal processing chip are both soldered to the top of the substrate.

[0008] As a preferred technical solution of the present invention, the inner shell and the outer shell are both made of metal material, and the inner shell is fixedly connected to the base plate via a first connecting portion.

[0009] As a preferred technical solution of the present invention, the outer shell is fixedly connected to the base plate via a second connecting portion, and a cavity is provided between the outer shell and the inner shell.

[0010] As an optimal technical solution of the present invention, the sealing adjustment mechanism includes a movable groove, an expansion spring, a movable sealing plate, a through hole, a connecting groove and a slot. The movable groove is arranged on the inner wall of the outer shell, and an expansion spring is arranged inside the movable groove. One end of the expansion spring is fixedly connected to the movable sealing plate. A through hole is provided on the outer shell, a connecting groove is provided on one side of the through hole, and a slot is provided on the movable sealing plate. There are multiple sealing adjustment mechanisms, and the sealing adjustment mechanisms are evenly and symmetrically distributed on the top and both sides of the outer shell.

[0011] As an optimal technical solution of the present invention, the outer diameter of the movable sealing plate is adapted to the inner diameters of the movable groove and the connecting groove, the movable sealing plate is movably sleeved in the movable groove, and the movable sealing plate is movably plugged in the connecting groove.

[0012] As a preferred technical solution of the present invention, the inner diameter width of the slot is greater than the inner diameter width of the through hole.

[0013] Compared with the prior art, the present invention provides a packaging structure for a micro-electromechanical system microphone, which has the following beneficial effects:

[0014] The packaging structure of a micro-electromechanical system microphone can effectively improve the electromagnetic shielding performance by setting an inner shell and an outer shell for coordinated use. The MEMS microphone will be interfered by the electromagnetic signal, thereby generating noise and affecting the sound signal, so as to facilitate better work and use. The sealing adjustment mechanism, the movable groove, the expansion spring, the movable sealing plate, the through hole, the connecting groove and the slot are set for coordinated use. When the internal temperature is too high, the expansion spring will expand due to the heat and push the movable sealing plate to insert it into the connecting groove, so that the slot and the through hole can be connected, so that the inside and outside of the shell are connected, which is convenient for rapid discharge of internal heat and convenient heat dissipation. It can prevent the gas between the double shells from exploding due to thermal expansion, so as to facilitate better work and use. When the temperature drops, the expansion spring will contract and pull the movable sealing plate to effectively seal the through hole, so as to facilitate better electromagnetic shielding work and avoid the opening being in an open state all the time, thereby affecting the electromagnetic shielding effect, so as to facilitate better long-term work and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the three-dimensional structure of the through-hole seal of the utility model;

[0016] Figure 2 This is a schematic diagram of the cross-sectional structure of the utility model;

[0017] Figure 3 This is a schematic diagram of the three-dimensional structure of the through hole opening of the utility model;

[0018] Figure 4 This is a structural schematic diagram of the movable sealing plate of the utility model.

[0019] In the figure: 1. substrate; 2. MEMS sensor chip; 3. signal processing chip; 4. inner shell; 5. first connecting part; 6. outer shell; 7. second connecting part; 8. sealing adjustment mechanism; 801. movable groove; 802. expansion spring; 803. movable sealing plate; 804. through hole; 805. connecting groove; 806. slot. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1-4In this embodiment: a packaging structure of a micro-electromechanical system microphone includes a substrate 1, a MEMS sensor chip 2 is fixedly mounted on the top of the substrate 1, and a signal processing chip 3 is fixedly mounted on one side of the MEMS sensor chip 2; an inner shell 4 is provided on the top of the substrate 1 to facilitate packaging of the microphone assembly; a first connecting portion 5 is provided at the bottom of the inner shell 4 to facilitate installation of the inner shell 4; an outer shell 6 is provided on the outside of the inner shell 4 to facilitate improving the electromagnetic shielding effect; a second connecting portion 7 is provided at the bottom of the outer shell 6 to facilitate installation of the outer shell 6; a sealing adjustment mechanism 8 is provided on the inner wall of the outer shell 6 to facilitate opening or sealing the outer shell 6.

[0022] In this embodiment, the MEMS sensor chip 2 and the signal processing chip 3 are both soldered to the top of the substrate 1, which facilitates fixed installation and connection and is convenient for operation and use;

[0023] In this embodiment, the inner shell 4 and the outer shell 6 are both made of metal material. The inner shell 4 is fixedly connected to the base plate 1 through the first connecting portion 5, which is convenient for connection and installation and easy to use.

[0024] In this embodiment, the outer shell 6 is fixedly connected to the substrate 1 through the second connecting portion 7. A cavity is provided between the outer shell 6 and the inner shell 4 to enhance the electromagnetic shielding effect and prevent noise from being easily generated and affecting the sound signal.

[0025] In this embodiment, the sealing adjustment mechanism 8 includes a movable groove 801, an expansion spring 802, a movable sealing plate 803, a through hole 804, a connecting groove 805 and a slot 806. The movable groove 801 is provided on the inner wall of the shell 6, and an expansion spring 802 is provided inside the movable groove 801. One end of the expansion spring 802 is fixedly connected to the movable sealing plate 803. A through hole 804 is provided on the shell 6, and a connecting groove 805 is provided on one side of the through hole 804. The movable sealing plate 803 is provided with a slot 806. A plurality of sealing adjustment mechanisms 8 are provided, and the sealing adjustment mechanisms 8 are evenly and symmetrically distributed on the top and both sides of the shell 6, so as to facilitate opening or sealing the shell 6 and facilitate better work and use;

[0026] In this embodiment, the outer diameter of the movable sealing plate 803 is adapted to the inner diameter of the movable groove 801 and the connecting groove 805. The movable sealing plate 803 is movably connected to the movable groove 801, and the movable sealing plate 803 is movably connected to the connecting groove 805, so that the movable sealing plate 803 can be adjusted to open or close the through hole 804.

[0027] In this embodiment, the inner diameter width of the slot 806 is greater than the inner diameter width of the through hole 804, which can facilitate air circulation and quickly dissipate internal heat.

[0028] The working principle and usage process of the present invention are as follows: during operation, when the microphone assembly generates high temperature, its heat will be transferred to the outside, and the expansion spring 802 will expand and contract due to the heat, pushing the movable sealing plate 803 to be inserted into the connecting groove 805, so that the internal slot 806 of the movable sealing plate 803 can be connected with the through hole 804, so that the internal heat can be quickly discharged through the slot 806 and the through hole 804, which is convenient for heat dissipation and prevents the gas between the double shells from expanding due to heat, causing the shell to explode, so as to facilitate better operation. When the temperature drops, the expansion spring 802 will contract and pull the movable sealing plate 803, which can effectively seal the through hole 804, thereby improving its anti-electromagnetic interference performance.

[0029] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A packaging structure for a micro-electromechanical system microphone, comprising a substrate (1), a MEMS sensor chip (2) fixedly mounted on the top of the substrate (1), a signal processing chip (3) fixedly mounted on one side of the MEMS sensor chip (2), an inner shell (4) provided on the top of the substrate (1), and a first connecting portion (5) provided on the bottom of the inner shell (4), characterized in that: An outer shell (6) is provided on the outside of the inner shell (4), a second connecting portion (7) is provided on the bottom of the outer shell (6), and a sealing adjustment mechanism (8) is provided on the inner wall of the outer shell (6).

2. The packaging structure of a micro-electromechanical system microphone according to claim 1, characterized in that: The MEMS sensor chip (2) and the signal processing chip (3) are both soldered to the top of the substrate (1) by soldering.

3. The packaging structure of a MEMS microphone according to claim 1, wherein: The inner shell (4) and the outer shell (6) are both made of metal material, and the inner shell (4) is fixedly connected to the base plate (1) via a first connecting portion (5).

4. The packaging structure of a micro-electromechanical system microphone according to claim 1, characterized in that: The outer shell (6) is fixedly connected to the base plate (1) via a second connecting portion (7), and a cavity is provided between the outer shell (6) and the inner shell (4).

5. The packaging structure of a micro-electromechanical system microphone according to claim 1, characterized in that: The sealing adjustment mechanism (8) comprises a movable groove (801), an expansion spring (802), a movable sealing plate (803), a through hole (804), a connecting groove (805) and a slot (806); the movable groove (801) is arranged on the inner wall of the housing (6); an expansion spring (802) is arranged inside the movable groove (801); one end of the expansion spring (802) is fixedly connected to the movable sealing plate (803); a through hole (804) is provided on the housing (6); a connecting groove (805) is provided on one side of the through hole (804); and a slot (806) is provided on the movable sealing plate (803); a plurality of the sealing adjustment mechanisms (8) are provided, and the sealing adjustment mechanisms (8) are evenly and symmetrically distributed on the top and both sides of the housing (6).

6. The packaging structure of a micro-electromechanical system microphone according to claim 5, characterized in that: The outer diameter of the movable sealing plate (803) is adapted to the inner diameters of the movable groove (801) and the connecting groove (805). The movable sealing plate (803) is movably sleeved with the movable groove (801), and the movable sealing plate (803) is movably plugged with the connecting groove (805).

7. The packaging structure of a micro-electromechanical system microphone according to claim 5, characterized in that: The inner diameter width of the slot (806) is greater than the inner diameter width of the through hole (804).

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