CN111083623A

CN111083623A - MEMS device

Info

Publication number: CN111083623A
Application number: CN201911423033.6A
Authority: CN
Inventors: 畠山庸平; 林育菁
Original assignee: Goertek Inc
Current assignee: Weifang Goertek Microelectronics Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-28
Also published as: WO2021135112A1

Abstract

The invention discloses an MEMS device, which comprises a substrate, an MEMS chip layer and a grid film, wherein the substrate is provided with a first surface and a second surface, and a first through hole which is communicated with the substrate is formed on the substrate; the MEMS chip layer is arranged on one side of the second surface of the substrate; the grid membrane is arranged on one side of the first surface of the substrate, a sound transmission area is formed on the grid membrane at a position corresponding to the first through hole, and meshes are distributed on the sound transmission area. The substrate of the MEMS device has good supporting effect on the grid membrane while completing the traditional structure packaging and signal transmission, and the MEMS device simplifies the assembly process and reduces the manufacturing cost.

Description

MEMS device

Technical Field

The invention belongs to the technical field of sound-electricity conversion, and particularly relates to an MEMS (micro-electromechanical system) device.

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. How to well integrate the supporting part with the microphone assembly to solve the stress concentration is a key problem to be solved urgently in the field of microphones.

Disclosure of Invention

It is an object of the present invention to provide a MEMS device.

According to a first aspect of the present invention, there is provided a MEMS device comprising:

the substrate is provided with a first surface and a second surface, and a first through hole is formed in the substrate;

the MEMS chip layer is arranged on one side of the second surface of the substrate and covers the first through hole;

the grid membrane is arranged on one side of the first surface of the substrate, an acoustic transmission area is formed on the grid membrane at a position corresponding to the first through hole, meshes are distributed on the acoustic transmission area, and the acoustic transmission area is configured to allow sound to pass through so as to be transmitted to the MEMS chip layer.

Optionally, the material of the grid film is metallic glass.

Optionally, an insulating layer is disposed on the second surface of the substrate, the MEMS chip layer is disposed on one side of the insulating layer, which is away from the second surface, a through second through hole is formed in the insulating layer, and the second through hole is communicated with the first through hole.

Optionally, the sound-transmitting area is rectangular, and the radial end surface of the first through hole is rectangular.

Optionally, the corner positions of the sound-transmitting areas are chamfered.

Optionally, the mesh is a rectangular hole, and an included angle between the edge of the mesh and the edge of the sound-transmitting area is not 0 °.

Optionally, the mesh openings are circular arc shaped openings.

Optionally, the mesh has a shape aspect ratio greater than 2.

Optionally, the substrate is made of a silicon-based material, the first through hole is configured to be formed by an anisotropic etching process, and the sound-transmitting region is permeable to an etchant.

Optionally, the mesh film is configured to be formed on the substrate by a sputtering or vapor deposition process;

the acoustically transparent regions are configured to form the mesh by a patterned etching process.

One technical effect of the invention is that:

the invention discloses an MEMS device, which comprises a substrate, an MEMS chip layer and a grid film, wherein the substrate is provided with a first surface and a second surface, and a first through hole which is communicated with the substrate is formed on the substrate; the MEMS chip layer is arranged on one side of the second surface of the substrate; the grid membrane is arranged on one side of the first surface of the substrate, a sound transmission area is formed on the grid membrane at a position corresponding to the first through hole, and meshes are distributed on the sound transmission area. The substrate plays a good role in supporting the grid membrane.

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 MEMS device of the present invention;

FIG. 2 is a schematic structural diagram of an acoustically transparent region of an MEMS device of the present invention;

FIG. 3 is a schematic structural view of another acoustically transparent region of a MEMS device of the present invention;

FIG. 4 is a schematic structural diagram of another acoustically transparent region of a MEMS device of the present invention;

fig. 5 is a schematic structural view of another sound-transmitting area of the MEMS device of the present invention.

Wherein: 1-a substrate; 101-a first surface; 102-a second surface; 2-a first via; 3-a MEMS chip layer; 4-a grid film; 5-a sound-transparent zone; 6-an insulating layer; 7-second via hole.

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 MEMS device, comprising:

the MEMS chip comprises a substrate 1, an MEMS chip layer 3 and a grid film 4, wherein the substrate 1 is provided with a first surface 101 and a second surface 102, and a first through hole 2 which penetrates through the substrate 1 is formed; the MEMS chip layer 3 is arranged on one side of the second surface 102 of the substrate 1, and the MEMS chip layer 3 covers the first through hole 2; the mesh membrane 4 is disposed on one side of the first surface 101 of the substrate 1, the mesh membrane 4 is formed with an acoustic transmission region 5 at a position corresponding to the first through hole 2, mesh holes are distributed on the acoustic transmission region 5, and the acoustic transmission region 5 is configured to allow sound to pass through so as to transmit to the MEMS chip layer 3.

The mesh membrane 4 is arranged on one side of the substrate 1, and the sound transmission area 5 of the mesh membrane 4 is configured to allow sound to pass through and prevent external dust and impurities from entering the MEMS device, so that the normal operation of the MEMS chip layer 3 is ensured.

The conventional dustproof structure similar to the grid film 4 generally needs to be provided with a carrier for supporting the grid film, and the grid film is connected to the MEMS device through the carrier, which is problematic in that, on the one hand, the arrangement of the carrier increases the assembly complexity and the manufacturing cost of the MEMS device, and more importantly, the mechanical properties of the carrier and the MEMS device are greatly different due to the difference in thickness and material characteristics, so that in the thermal expansion process, the carrier and the MEMS device deform to different degrees to generate high stress, and if the stress is continuously transmitted to the grid film, the grid film has a lower structural strength due to the fact that the grid film is provided with more through holes, and the grid film is easily wrinkled or even damaged due to the large deformation and stress. In the invention, the substrate 1 of the MEMS device simultaneously plays a role of a carrier, thereby not only playing a role of supporting the grid membrane 4, but also simplifying the assembly process of the MEMS device and reducing the manufacturing cost.

Optionally, the material of the mesh film 4 is metallic glass. Metallic glass not only has ultra-high strength similar to metal, but also has good ductility, is easy to form, and can be rebounded to its original shape soon after being deformed. Therefore, the grid membrane 4 can be firmly combined with the substrate 1 while being combined with the substrate 1, and the structural stability of the MEMS device is improved.

Optionally, referring to fig. 1, an insulating layer 6 is disposed on the second surface 102 of the substrate 1, the MEMS chip layer 3 is disposed on one side of the insulating layer 6, which is far away from the second surface 102, a through second through hole 7 is formed in the insulating layer 6, the second through hole 7 is communicated with the first through hole 2, and the insulating layer 6 is made of one of plastic and rubber.

In the MEMS device, the MEMS chip layer 3 is used as a main component for receiving a sound signal, and it is necessary to maintain high sensitivity and stability, and then the output signal of the MEMS chip layer 3 is transmitted to the ASIC chip by a gold wire, and the ASIC chip processes the signal of the MEMS chip layer 3 and transmits the processed signal to the substrate 1 to be output to the outside. Therefore, in order to ensure the relative independence of the operation of the MEMS chip layer 3 and the substrate 1, the present invention provides an insulating layer 6 between the substrate 1 and the MEMS chip layer 3.

The insulating layer 6 is made of one of plastic and rubber. The plastic can be one or a combination of more of PP material, PVC material, PET material, PS material, ABS resin, PC material and PA material, and has the characteristics of light weight, stable chemical property, good insulating property, good impact resistance and the like, good transparency and abrasion resistance, good formability and colorability and low processing cost; the rubber can be one or a combination of a plurality of natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, fluorine rubber, polyurethane rubber, acrylate rubber and epichlorohydrin rubber, and has good wear resistance, high elasticity, breaking strength and elongation. Therefore, the plastic or rubber not only can provide a good insulation effect for the substrate 1 and the MEMS chip layer 3, but also has a low cost and good molding characteristics.

Alternatively, referring to fig. 2 and 3, the sound-transmitting region 5 has a rectangular shape, and the radial end surface of the first through-hole 2 has a rectangular shape as the sound-transmitting region 5.

The sound-transmitting zone 5 is set to be rectangular, so that the sound-transmitting zone 5 can be positioned conveniently, and the forming efficiency of the sound-transmitting zone 5 can be improved. More importantly, the grid film 4 is made of a crystal material, so that the sound-transmitting region 5 is set to be rectangular, on one hand, crystal forming can be facilitated, on the other hand, the rectangular edge of the sound-transmitting region 5 can be kept consistent with the crystal face and the crystal orientation of the crystal, so that the crystal sound-transmitting region 5 with more stable performance can be obtained, and the sound-transmitting region 5 can exert a good dustproof effect while passing sound.

Alternatively, referring to fig. 4 and 5, the corner positions of the sound-transmitting zone 5 have chamfers.

In a specific embodiment, in fig. 4, the edge of the sound-transmitting area 5 perpendicular to the plane thereof is configured to have an arc-shaped chamfer, since the compact area of the mesh membrane 4 has higher strength, and the mesh is disposed on the sound-transmitting area 5 in the middle of the mesh membrane 4, which inevitably results in lower strength of the sound-transmitting area 5, and inevitably generates larger stress between the compact area of the mesh membrane 4 and the sound-transmitting area 5, and the edge of the sound-transmitting area 5 perpendicular to the plane thereof is configured to have the arc-shaped chamfer so as to well disperse the stress, thereby avoiding the stress from concentrating on the edge of the sound-transmitting area 5 perpendicular to the plane thereof, and further improving the protection performance and the service life of the mesh membrane 4.

In another specific embodiment, in fig. 5, one side of the plane of the sound-transmitting region 5 is provided with a surface with a certain slope on the periphery, and the periphery is inclined towards the center. Because the compact area of net membrane 4 has higher intensity, and the net is provided with on the sound-transmitting area 5 in the middle of the net membrane 4, must lead to like this the intensity of sound-transmitting area 5 reduces, must produce great stress between the compact area of net membrane 4 with sound-transmitting area 5, and will sound-transmitting area 5's plane one side sets up to the surface that the periphery has certain inclination, can guarantee sound-transmitting area 5 with the connection of the compact area of net membrane 4 is thin from the thickness way, just so can let thick region bear great stress, the thin region in sound-transmitting area 5 center just can bear less stress only, has improved like this the barrier propterty and the life of net membrane 4.

Alternatively, referring to fig. 2, the mesh is rectangular, and the angle between the edge of the mesh and the edge of the sound-transmitting area 5 is not 0 °.

Conventional meshes are generally arranged as circular holes, but in such an arrangement of circular holes, in order to balance the size, number and hole pitch of the holes, the aperture ratio is inevitably low. And will the mesh sets up rectangular hole, and a plurality of rectangular holes can arrange side by side in addition, just so improved greatly the mesh percent opening of sound-permeable zone 5.

Specifically, the sound-transmitting region 5 is generally made of a crystal material and has a 100 crystal plane and a 110 crystal plane, so that an included angle formed by the edge of the mesh of the sound-transmitting region 5 and the edge of the sound-transmitting region 5 is not 0 °, the correlation between the rectangular hole and the 100 crystal plane of the crystal can be improved, preferably, the opening direction of the rectangular hole is consistent with the opening direction of the 100 crystal plane of the crystal, so that the crystal sound-transmitting region 5 with more stable performance can be obtained, and the sound-transmitting region 5 can play a good dustproof effect while passing through sound.

Alternatively, referring to fig. 3, the mesh holes are circular arc shaped holes. Similarly, the meshes are arranged to be circular arc holes, and a plurality of circular arc holes can be arranged side by side, so that the aperture ratio of the meshes of the sound-transmitting area 5 is greatly improved.

Optionally, the mesh has a shape aspect ratio greater than 2. The shape aspect ratio of the mesh directly affects the mesh opening ratio of the sound-transmitting region 5, and the larger the aspect ratio, the larger the mesh opening ratio of the sound-transmitting region 5, so that setting the shape aspect ratio of the mesh to be more than 2 can significantly improve the mesh opening ratio of the sound-transmitting region 5.

Alternatively, the material of the substrate 1 is a silicon-based material, the first through hole 2 is configured to be formed by an anisotropic etching process, and the sound-transmitting region 5 is permeable to an etchant.

The silicon-based material has the characteristics of high temperature resistance, radiation resistance, high electron transfer rate and the like, and can obtain a multifunctional substrate with high processing speed and high integration level. The silicon-based material has different crystal orientation atom densities, so that anisotropic etching can be well completed, namely the crystal orientation etching rate with high atom density is low, and the crystal orientation etching rate with low atom density is high, so that the substrate 1 of the silicon-based material with stable structure and performance can be obtained.

Optionally, the mesh film 4 is configured to be formed on the substrate 1 by a sputtering or vapor deposition process; the sound-transmitting zone 5 is configured to form the mesh by a patterned etching process.

Specifically, the forming process of the MEMS device may be:

forming a substrate 1 having a first through-hole 2 by anisotropic etching;

compounding the insulating layer 6 side having the second via 7 to the second surface 102 of the substrate 1;

the MEMS chip layer 3 is connected to the other side of the insulating layer 6;

forming a complete mesh film 4 on the first surface 101 of the substrate 1 by sputtering;

arranging a mask on one side of the grid film 4 far away from the substrate 1, wherein a mesh pattern is arranged at the position of the mask corresponding to the sound transmission area 5;

the sound-transmitting region 5 having mesh holes is formed on the mesh film 4 by patterned etching.

The molding process well matches the material with the molding process, simplifies the process flow and simultaneously forms the MEMS device with a stable structure.

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 MEMS device, comprising:

2. The MEMS device, as recited in claim 1, wherein the material of the mesh membrane is metallic glass.

3. The MEMS device of claim 1, wherein an insulating layer is disposed on the second surface of the substrate, the MEMS chip layer is disposed on a side of the insulating layer away from the second surface, and a second through hole is formed in the insulating layer and communicates with the first through hole.

4. The MEMS device, as recited in claim 1, wherein the acoustically transparent region is rectangular in shape and the radial end of the first via is rectangular in shape.

5. The MEMS device of claim 4, wherein corner locations of the acoustically transparent regions have chamfers.

6. The MEMS device, as recited in claim 4, wherein the mesh is a rectangular shaped aperture, and wherein an angle between an edge of the mesh and an edge of the acoustically transparent region is different from 0 °.

7. The MEMS device, as recited in claim 4, wherein the mesh is a circular arc shaped hole.

8. The MEMS device, as recited in claim 1, wherein the mesh has a shape aspect ratio greater than 2.

9. The MEMS device, as recited in any of claims 1-8, wherein the substrate is a silicon-based material, the first via is configured to be formed via an anisotropic etching process, and the acoustically transparent region is permeable to an etchant.

10. The MEMS device, as recited in any of claims 1-8, wherein the mesh film is configured to be formed on the substrate by a sputtering or vapor deposition process;