CN111163410A

CN111163410A - A dustproof construction and MEMS microphone packaging structure for MEMS device

Info

Publication number: CN111163410A
Application number: CN201911416451.2A
Authority: CN
Inventors: 林育菁; 佐佐木宽充; 畠山庸平
Original assignee: Goertek Inc
Current assignee: Weifang Goertek Microelectronics Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-05-15
Also published as: WO2021135121A1

Abstract

The invention discloses a dustproof structure for an MEMS device and an MEMS microphone packaging structure, wherein the dustproof structure comprises a grid film and a carrier, the carrier is of a columnar frame structure, the carrier is provided with a through opening arranged along the axial direction of the carrier, and the side wall of the carrier is provided with an arc-shaped surface; the grid membrane is provided with a fixed connecting area and a sound transmission area, the fixed connecting area surrounds the sound transmission area, and the fixed connecting area is positioned at the edge of the grid membrane; the grid film is arranged on the end face of the carrier, and the sound transmission area corresponds to the position of the opening. The side wall of the carrier is set to be an arc-shaped surface, so that deformation and stress caused by the difference of the thickness size and the material characteristics of the carrier and the MEMS device can be well released, stress concentration is avoided and is transmitted to the grid film, the grid film is well protected, and the stability and the service life of the dustproof structure are improved.

Description

A dustproof construction and MEMS microphone packaging structure for MEMS device

Technical Field

The invention belongs to the technical field of sound-electricity conversion, and particularly relates to a dustproof structure for an MEMS device and an MEMS microphone packaging structure.

Background

With the rapid development of electroacoustic technology, various electroacoustic products are developed. A microphone, as a transducer for converting sound into an electrical signal, is one of the very important devices in electro-acoustic products. Nowadays, microphones have been widely used in various types of electronic products, such as mobile phones, tablet computers, notebook computers, VR devices, AR devices, smartwatches, and smart wearing. In recent years, for a microphone packaging structure, the design of the structure thereof has become an important point and a focus of research by those skilled in the art.

The existing microphone package structure is generally: the chip package comprises a shell with a containing cavity, and components such as a chip assembly (for example, a MEMS chip and an ASIC chip) are contained and fixed in the containing cavity; and a sound pickup hole is also arranged on the shell. However, in long-term application, it is found that external particles and foreign matters such as dust and impurities are easily introduced into the accommodating cavity of the microphone through the sound pickup hole, and the external particles and foreign matters cause certain damage to components such as a chip assembly in the accommodating cavity, and finally affect the acoustic performance and the service life of the microphone.

In view of the above problems, the prior art generally adopts a solution that a corresponding isolation component is disposed on a sound pickup hole of a microphone package structure to block the entry of external particles, foreign matters, and the like. The existing isolation assembly comprises a supporting part and isolation mesh cloth. When the isolation component is used, the isolation component is installed on the sound pickup hole. However, in the existing isolation assembly, due to the difference between the thickness and the material characteristics of the supporting part and the isolation mesh cloth, expansion deformation of each part in the isolation assembly in different degrees is easily caused after heating, so that stress concentration and deformation damage are easily caused, and the sound production quality of the microphone is influenced.

Disclosure of Invention

An object of the present invention is to provide a dust-proof structure for a MEMS device and a MEMS microphone packaging structure.

According to a first aspect of the present invention, there is provided a dust-proof structure for a MEMS device, comprising:

the carrier is of a columnar frame structure and is provided with a through opening arranged along the axial direction of the carrier, and the side wall of the carrier is provided with an arc-shaped surface;

a mesh membrane having a fixed attachment zone and an acoustically transparent zone, the fixed attachment zone surrounding the acoustically transparent zone, the fixed attachment zone being located at an edge of the mesh membrane;

the grid film is arranged on the end face of the carrier, and the sound transmission area corresponds to the position of the opening.

Optionally, the carrier is in a polygonal prism structure, and the side walls of the carrier are formed with the arc-shaped surfaces at the edges.

Optionally, the carrier has a quadrangular prism-like structure.

Optionally, the arcuate surface is formed by a chamfered chamfer.

Optionally, the carrier is in a cylindrical structure or an elliptic cylindrical structure, and the side wall of the carrier integrally forms the arc surface.

Optionally, the sound-transparent region is made of an isolation mesh configured to pass sound through.

Optionally, the separation net is an organic non-woven fabric or a metal screen.

Optionally, the mesh membrane has a buffer zone surrounding the acoustically transparent zone, the fixed connection zone surrounding the buffer zone;

the buffer area and the sound-transmitting area correspond to the position of the opening.

Optionally, the buffer area and the fixed connection area are made of the same material.

According to a second aspect of the present invention, there is provided a MEMS microphone packaging structure, comprising:

the sound hole is arranged on the shell and used for communicating the inside and the outside of the shell;

a microphone device fixedly disposed within the housing;

the carrier is fixedly connected with the shell;

the grid film closes the sound hole; and/or the mesh membrane is spaced between the sound aperture and the microphone device.

One technical effect of the invention is that:

the invention discloses a dustproof structure for an MEMS device, which comprises a grid film and a carrier, wherein the carrier is of a columnar frame structure, the carrier is provided with a through opening arranged along the axial direction of the carrier, and the side wall of the carrier is provided with an arc-shaped surface. The side wall of the carrier is arranged to be an arc-shaped surface, so that stress concentration is avoided and is transmitted to the grid film, and the grid film is well protected.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic structural diagram of a dustproof structure for a MEMS device according to the present invention;

FIG. 2 is a schematic structural diagram of another dustproof structure for a MEMS device according to the present invention;

FIG. 3 is a schematic structural diagram of a dustproof structure for a MEMS device according to another embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a dustproof structure for a MEMS device according to still another embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an MEMS microphone package structure according to the present invention;

fig. 6 is a schematic structural diagram of another MEMS microphone package structure according to the present invention.

Wherein: 100-a dustproof structure; 1-a grid film; 101-a fixed attachment area; 102-an acoustically transparent region; 103-a buffer; 2-a carrier; 3-opening; 4-a housing; 5-a sound hole; 6-microphone device; 7-substrate.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Referring to fig. 1, the present invention discloses a dust-proof structure 100 for a MEMS device, comprising:

the carrier 2 is of a columnar frame structure, the carrier 2 is provided with a through opening 3 arranged along the axial direction of the carrier, and the side wall of the carrier 2 is provided with an arc-shaped surface; the grid membrane 1 is provided with a fixed connection area 101 and a sound transmission area 102, wherein the fixed connection area 101 is surrounded on the periphery of the sound transmission area 102, and the fixed connection area 101 is positioned at the edge of the grid membrane 1; the mesh membrane 1 is arranged on the end face of the carrier 2, and the sound-transmitting area 102 corresponds to the position of the opening 3.

The sound-transmitting area 102 of the grid membrane 1 is provided with a plurality of through holes through which air can pass, so that sound transmission is facilitated, the carrier 2 plays a good supporting and protecting role in the grid membrane 1, so that direct contact damage to the grid membrane 1 can be avoided, the opening 3 and the sound-transmitting area 102 on the grid membrane 1 are arranged oppositely, so that a smooth channel is provided for air, and sound transmission is facilitated.

More importantly, when the dustproof structure 100 is applied to a MEMS device, the carrier 2 is generally fixedly connected to the MEMS device, and the mechanical properties of the carrier 2 and the MEMS device are different due to different thickness dimensions and different material characteristics, so that the carrier 2 and the MEMS device deform to different degrees during thermal expansion, and generate high stress, and if the stress is continuously transmitted to the mesh membrane 1, the structural strength of the mesh membrane 1 is low due to the fact that the mesh membrane 1 is provided with more through holes, and the mesh membrane 1 is easily wrinkled or even damaged due to the large deformation and stress. In the invention, the side wall of the carrier 2 is set to be an arc surface, so that the deformation and stress caused by the difference of the thickness dimension and the material property of the carrier 2 and the MEMS device can be well released, the stress concentration is avoided and is transmitted to the grid film 1, the grid film 1 is well protected, and the stability and the service life of the dustproof structure 100 are improved.

Specifically, the arc surface may be a smooth arc surface, or may be when the lateral wall of the carrier 2 has an edge, an edge is provided with a surface close to an arc, which is formed by connecting one, two or more tangent planes, a plurality of the tangent planes and the lateral wall of the carrier 2 form an obtuse angle, the obtuse angle is close to 180 °, more tangent planes are required to connect the lateral walls on both sides of the edge of the carrier 2, and the curved surface formed by connecting the tangent planes is close to the arc surface.

Optionally, the carrier 2 is in the form of a polygonal prism, the side walls of the carrier 2 being formed with the curved surfaces at the edges.

When the carrier 2 is in a polygonal prism structure, the carrier can be a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism or more prisms, and when the number of the prisms of the prismatic carrier 2 is more, the closer to the cylinder, the closer to the arc surface the edge of the side wall of the carrier 2 is; when the prism-shaped carrier 2 has fewer edges, such as a triangular prism, a quadrangular prism or a pentagonal prism-shaped carrier 2, the angle of the edge of the carrier 2 is small, which easily causes stress concentration, and thus the carrier 2 and even the grid film 1 are damaged, but in the present invention, the arc-shaped surface is formed on the edge of the side wall of the carrier 2, which greatly disperses the stress applied to the carrier 2 and avoids stress concentration.

Referring to fig. 1, in a specific embodiment, the carrier 2 has a quadrangular prism structure, and the side walls of the carrier 2 are formed with the arc-shaped surfaces at four edges. When the dustproof structure 100 is applied to an MEMS device, the carrier 2 may be fixedly connected to the MEMS device, and more importantly, four edges of the carrier 2 need to be fixedly connected to the MEMS device, and an acting force between the carrier 2 and the MEMS device is directly concentrated on the four edges of the carrier 2, so that the four edges having arc surfaces can well disperse stress, thereby protecting the carrier 2 and even the mesh membrane 1.

Alternatively, the arcuate surface may be formed by a chamfered chamfer.

Referring to fig. 2, in another specific embodiment, the carrier 2 has a quadrangular prism structure, and the side walls of the carrier 2 are formed with chamfer structures at four edges, wherein the chamfer structures are formed by a chamfer surface, and the chamfer surface forms an obtuse angle with the side walls of two adjacent carriers 2, so that the chamfer surface and the side walls of two adjacent carriers 2 form a structure close to the arc-shaped surface, and the stress applied to the carrier 2 is greatly dispersed.

Referring to fig. 3, in another specific embodiment, the carrier 2 has a quadrangular prism structure, and the side walls of the carrier 2 are formed with a chamfer structure at four edges, wherein the chamfer structure is formed by two chamfers, and an obtuse angle is formed between two chamfers and between two adjacent side walls of the carrier 2, so that the two chamfers and the adjacent two side walls of the carrier 2 form a structure close to the arc-shaped surface, and the stress applied to the carrier 2 is greatly dispersed. Of course, the number of the chamfer can be three, four, five or even more, and the more the chamfer is, the closer the structure of the chamfer to the side wall of the two adjacent carriers 2 is to the arc surface, so that the stress can be better dispersed.

Optionally, the carrier 2 is in a cylindrical structure or an elliptic cylindrical structure, and the side wall of the carrier 2 integrally forms the arc surface.

Referring to fig. 4, in another specific embodiment, the carrier 2 has a cylindrical structure, and the side walls of the carrier 2 integrally form the arc-shaped surface, so that the arc-shaped surface structure is not only simple to manufacture and easy to mold, but also the entire side walls serve as arc-shaped surfaces, and the stress applied to the carrier 2 is greatly dispersed.

Optionally, the sound-transparent region 102 is made of an isolation mesh configured to pass sound through. The separation net can be an organic non-woven fabric or a metal screen.

When the isolation net is an organic non-woven fabric, the size of the through holes on the surface of the non-woven fabric can be flexibly adjusted by virtue of the soft and breathable planar structure and higher toughness of the non-woven fabric, so that the isolation net can provide better sound transmissibility for the sound transmission area 102 and is suitable for MEMS devices with higher requirements on dustproof effect; when the separation net is a metal screen, the metal screen has high strength, so that a good dustproof effect can be achieved under a very thin condition, the internal space of the dustproof structure 100 is saved, and the good dustproof effect is achieved.

Referring to fig. 1 to 4, optionally, the mesh membrane 1 has a buffer zone 103, the buffer zone 103 surrounds the sound-transmitting zone 102, and the fixed connection zone 101 surrounds the buffer zone 103; the buffer area 103 and the sound-transmitting area 102 correspond to the position of the opening 3.

The fixed connection area 101 of the mesh membrane 1 provides a stable connection structure for the mesh membrane 1, but the structural strength is high, the sound transmission area 102 is provided with through holes to facilitate sound transmission and simultaneously play a good dustproof effect, but the structural strength is low, so when the fixed connection area 101 is directly connected with the sound transmission area 102, due to the difference of the thickness and the material characteristics of the fixed connection area 101 and the sound transmission area, the fixed connection area and the sound transmission area are easily stressed unevenly, and the possibility of wrinkles and even damage is brought to the sound transmission area 102. The buffer area 103 of the present invention can indirectly transmit the deformation and stress of the fixed connection area 101 to the sound-transmitting area 102, thereby providing more space for the slow deformation, stress dispersion and structural stability of the sound-transmitting area 102.

Alternatively, in one embodiment, the material of the buffer area 103 and the material of the fixed connection area 101 may be the same. This simplifies the structure of the dust-proof structure 100, providing the possibility of integrating the buffer area 103 with the fixed attachment area 101.

The MEMS device may be a MEMS microphone, MEMS sensor, MEMS chip, MEMS switch, or the like.

Referring to fig. 5 and 6, the present invention also discloses a MEMS microphone packaging structure, including:

if a shell 4 with a containing cavity exists, the shell 4 is provided with a sound hole 5, and the sound hole 5 is used for communicating the inside and the outside of the shell 4;

a microphone device 6, said microphone device 6 being fixedly arranged within said housing 4;

the dustproof structure 100, the carrier 2 and the shell 4 are fixedly connected;

the mesh membrane 1 closes the sound hole 5; and/or the mesh membrane 1 is spaced between the sound aperture 5 and the microphone device 6.

The carrier 2 of the dust-proof structure 100 may be fixedly connected to the housing 4, and for a specific position of the carrier 2, the dust-proof structure 100 may be disposed outside the housing 4 opposite to the sound hole 5, may be disposed inside the housing 4 opposite to the sound hole 5, or may be further disposed directly around the microphone device 6 in the housing 4, may be disposed directly around a plurality of microphone devices 6, or may be disposed only around an important microphone device 6 such as a chip. It is also possible to use the dust-proof structure 100 around the microphone device 6 and the dust-proof structure 100 at the sound hole 5 for a double protection.

Specifically, the housing 4 includes a substrate 7, the sound hole 5 is disposed on the substrate 7, the dust-proof structure 100 seals the sound hole 5, the microphone device 6 includes a MEMS chip, the dust-proof structure 100 is spaced between the sound hole 7 and the MEMS chip, and the dust-proof structure 100 and the MEMS chip may be directly connected or not connected to form a spacing support structure as shown in fig. 5.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A dust-proof structure for a MEMS device, comprising:

2. The dust-repellent structure according to claim 1, wherein said carrier has a polygonal prism-like structure, and said side walls of said carrier are formed with said arcuate surfaces at the edges.

3. The dust-repellent structure according to claim 2, wherein said carrier has a quadrangular prism-like structure.

4. The dust-proof structure according to claim 2, wherein the arc-shaped surface is constituted by a chamfered chamfer.

5. The dustproof structure according to claim 1, wherein the carrier has a cylindrical structure or an elliptic cylindrical structure, and the side walls of the carrier integrally form the arc-shaped surface.

6. The dust-proof structure of claim 1, wherein the sound-transparent region is made of an isolation mesh configured to allow sound to pass through.

7. The dustproof structure according to claim 6, wherein the spacer net is an organic non-woven fabric or a metal mesh.

8. The dust-proof structure according to claim 1, wherein said mesh film has a buffer region surrounded by said sound-transmitting region, and said fixed connection region is surrounded by said buffer region;

9. The dustproof structure according to claim 8, wherein the buffer area and the fixed connection area are made of the same material.

10. A MEMS microphone package structure, comprising:

a microphone device fixedly disposed within the housing;

the dust-repellent structure of any one of claims 1-9, wherein said carrier is fixedly attached to said housing;