CN211557478U

CN211557478U - A dustproof construction and MEMS microphone packaging structure for MEMS device

Info

Publication number: CN211557478U
Application number: CN201922491760.8U
Authority: CN
Inventors: 林育菁; 宫岛博志; 佐野豊
Original assignee: Weifang Goertek Microelectronics Co Ltd
Current assignee: Weifang Goertek Microelectronics Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-09-22
Anticipated expiration: 2029-12-31

Abstract

The utility model discloses a dustproof construction and MEMS microphone packaging structure for MEMS device, the dustproof construction for MEMS device includes the net membrane and is the carrier of column structure, and the net membrane has fixed connection region and sound transmission area, and fixed connection region encircles around the sound transmission area, and fixed connection region is located the edge of net membrane; the carrier is provided with a through opening, the opening corresponds to the position of the sound transmission area, the carrier is provided with a first end face and a second end face which are opposite, the first end face is connected to one side of the fixed connection area, and the second end face is configured to be connected with a substrate of the MEMS device; the outer contour of the carrier at the first end surface along the circumferential direction of the columnar structure is larger than the outer contour of the carrier at the second end surface along the circumferential direction of the columnar structure.

Description

A dustproof construction and MEMS microphone packaging structure for MEMS device

Technical Field

The utility model belongs to the technical field of the acoustoelectric conversion, specifically, relate to a dustproof construction and MEMS microphone packaging structure for MEMS device.

Background

With the rapid development of electroacoustic technology, various electroacoustic products are developed. A microphone, which is a transducer device for converting a sound signal into an electrical signal, is one of the very important devices in an electroacoustic product. Nowadays, microphones have been widely used in various types of electronic products, such as mobile phones, tablet computers, notebook computers, VR devices, AR devices, and smart wearing. In recent years, the design of microphone package structures has become a focus and focus of research for 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. Therefore, 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.

To solve the above technical problems, the prior art generally adopts a solution that a corresponding isolation component is disposed on a sound pickup hole of a microphone packaging structure to block the entry of external particles, foreign matters, and the like. Existing isolation assemblies typically include a carrier and an isolation mesh that is mounted over the sound pick-up hole when the isolation assembly is in use.

When the existing isolation component is installed in a MEMS microphone packaging structure, for example, on a PCB board in the MEMS microphone packaging structure, an adhesive bonding method is generally adopted, in which the adhesive is first coated on the PCB board, and then the isolation component is placed on the PCB board for bonding. When the bonding conditions, such as the amount of adhesive used, the location of adhesive dispensing, the viscosity of the adhesive, the thickness of the carrier, the placement pressure, etc., are not sufficiently optimized, the adhesive is highly susceptible to spillage that can flow down the side walls of the carrier to the top of the spacer web. The overflowing adhesive is likely to pollute the blocking isolation mesh cloth, so that the airflow on the isolation mesh cloth is influenced, and the acoustic quality of the microphone is reduced. In view of the above, a new technical solution is needed to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a dustproof construction and MEMS microphone encapsulation knot for MEMS device.

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

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 carrier is of a columnar structure and provided with a through opening, the opening corresponds to the position of the sound transmission area, the carrier is provided with a first end face and a second end face which are opposite, the first end face is connected to one side of the fixed connection area, and the second end face is configured to be connected with a substrate of the MEMS device;

the outer contour of the carrier at the first end surface along the circumferential direction of the columnar structure is larger than the outer contour of the carrier at the second end surface along the circumferential direction of the columnar structure.

Optionally, the carrier has a tapered columnar structure, and the area of the second end surface is smaller than that of the first end surface.

Optionally, the carrier includes at least two carrier layers, the first end face is located on a first carrier layer of the carrier layers, the first carrier layer is connected to one side of the fixed connection region, other carrier layers are sequentially stacked and distributed on one side of the first carrier layer away from the grid film along the thickness direction of the grid film, and the second end face is located on a carrier layer of the carrier layers farthest away from the grid film;

at least the outer contour of the carrier layer farthest from the grid film along the circumferential direction of the columnar structure is smaller than the outer contour of the first carrier layer along the circumferential direction of the columnar structure.

Optionally, each layer of the carrier layer is sequentially reduced in outer contour along the circumferential direction of the columnar structure along the direction from the position close to the grid film to the position far away from the grid film.

Optionally, the carrier is configured to be fixed on the grid film in advance, and the outer contour and the opening are formed through a photolithography process;

the first carrier layer and the second carrier layer are formed by two times of photoetching processes respectively.

Optionally, the carrier is configured to be formed by a lithographic process;

and forming conical photoetching structures with complementary angles with the carriers on the grid film in advance, forming the carriers between the conical photoetching structures, and removing the conical photoetching structures through a photoetching process.

Optionally, the carrier is configured to be fixed on the mesh film in advance, and the outer contour and the opening are formed by a photolithography process.

Optionally, the material of the carrier is a metal material, and the carrier is configured to be manufactured by a metal plating process.

According to the utility model discloses an on the other hand provides a MEMS microphone packaging structure, and it includes:

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;

according to the dustproof structure, the adhesive is coated between the second end face of the carrier and the shell, and the second end face is fixedly bonded with the shell through a high-temperature bonding and curing process;

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

Optionally, a sidewall of the carrier adjacent to the second end surface is an adhesive overflow surface, and the adhesive is provided on the adhesive overflow surface.

The utility model discloses a technical effect lies in the utility model provides an among the dustproof construction for MEMS device, the carrier has relative first terminal surface and second terminal surface, owing to with the carrier in first terminal surface department along the outline design of column structure's circumference for being greater than the carrier in second terminal surface department along the outline of column structure's circumference, consequently after the adhesive spills over, the adhesive can meet very big resistance when climbing up along the lateral wall of carrier, just so greatly reduced the adhesive and climbed the possibility to the top of net membrane, thereby the condition in the sound-permeable zone of adhesive pollution net membrane has been avoided to a great extent, the air current of sound-permeable zone has been ensured flows.

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

Drawings

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

FIG. 1 is a schematic diagram of a prior art dust-proof structure;

fig. 2 is a first schematic diagram of a dustproof structure for a MEMS device according to an embodiment of the present invention;

fig. 3 is a second schematic diagram of a dustproof structure for a MEMS device according to an embodiment of the present invention;

FIG. 4 is a first schematic view of a photolithography process;

FIG. 5 is a second schematic view of a photolithography process;

fig. 6 is a first schematic diagram of a MEMS microphone package structure according to an embodiment of the present invention;

fig. 7 is a second schematic diagram of a MEMS microphone package structure according to an embodiment of the present invention;

fig. 8 is a third schematic diagram of a MEMS microphone package structure according to an embodiment of the present invention;

fig. 9 is a fourth schematic diagram of a MEMS microphone package structure according to an embodiment of the present invention;

fig. 10 is a fifth schematic view of a MEMS microphone package structure according to an embodiment of the present invention.

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: unless specifically stated otherwise, 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.

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.

The embodiment of the utility model provides a dustproof construction for MEMS device, it includes net membrane 1 and is the carrier 2 of columnar structure, net membrane 1 has fixed connection region 11 and sound-transmitting zone 12, fixed connection region 11 encircles around sound-transmitting zone 12, fixed connection region 11 is located the edge of net membrane 1; the carrier 2 is provided with a through opening 21, the opening 21 corresponds to the position of the sound-transmitting area 12, the carrier 2 is provided with a first end face 201 and a second end face 202 which are opposite, the first end face 201 is connected to one side of the fixed connection area 11, and the second end face 202 is configured to be connected with a substrate of a MEMS device; the outer contour of the carrier 2 in the circumferential direction of the columnar structure at the first end face 201 is larger than the outer contour of the carrier 2 in the circumferential direction of the columnar structure at the second end face 202.

In the similar dustproof structure in the prior art, referring to fig. 1, the outer contour of the carrier 2 'along the circumferential direction of the columnar structure is generally set to be equal everywhere, for example, the carrier 2' has a cylindrical structure. Thus, when the dustproof structure is adhered to the substrate of the MEMS device by using an adhesive, the adhesive easily climbs along the side wall of the carrier 2 'toward the top of the mesh film 1' after overflowing. The embodiment of the utility model provides an among the dustproof construction for MEMS device, refer to fig. 2, fig. 3 shows, carrier 2 has relative first terminal surface 201 and second terminal surface 202, because with carrier 2 in first terminal surface 201 department along the outline design of column structure's circumference for being greater than carrier 2 in second terminal surface 202 department along the outline of column structure's circumference, consequently after the adhesive overflows, the adhesive can meet very big resistance when climbing up along the lateral wall of carrier 2, the possibility of adhesive climbing to the top of net membrane 1 has just so greatly been reduced, thereby the condition of adhesive pollution sound-transparent region 12 of net membrane 1 has been avoided to a great extent, the air current of sound-transparent region 12 has been ensured to flow.

Referring to fig. 2, in one embodiment, the carrier 2 has a tapered cylindrical structure, and the area of the second end surface 202 is smaller than that of the first end surface 201.

In this embodiment, the cross section of the carrier 2 presents an inverted cone-shaped structure, the outer side wall of the carrier 2 is disposed obliquely, and the outer contour of the carrier 2 in the circumferential direction gradually increases from the direction away from the mesh membrane 1 to the direction close to the mesh membrane 1, i.e., from the second end face 202 to the first end face 201. Thus, when the adhesive overflows from the second end face 202 and ascends along the outer side wall of the carrier 2, the adhesive equivalently climbs on a steep wall surface, and the crawling resistance is gradually increased, so that the adhesive cannot climb to the top of the grid membrane 1 to a great extent, the condition that the adhesive pollutes the sound-transmitting area 12 of the grid membrane 1 is avoided to a great extent, and the airflow flowing of the sound-transmitting area 12 is ensured.

Referring to fig. 3, in one embodiment, the carrier 2 includes at least two carrier layers, the first end face 201 is located on a first carrier layer 22 of the carrier layers, the first carrier layer 22 is connected to one side of the fixed connection region 11, other carrier layers are sequentially stacked and distributed on one side of the first carrier layer 22 away from the mesh film along the thickness direction of the mesh film 1, and the second end face 202 is located on the carrier layer farthest from the mesh film 1; at least the outer contour of the carrier layer farthest from the mesh membrane 1 in the circumferential direction of the columnar structure is smaller than the outer contour of the first carrier layer 22 in the circumferential direction of the columnar structure.

In this embodiment, the circumferential outer contour from the first carrier layer 22 to the carrier layer farthest from the mesh film 1 may be designed to decrease layer by layer, forming a structure similar to a step, that is, each layer of the carrier layers decreases in sequence along the circumferential outer contour of the columnar structure along the direction from the position close to the mesh film 1 to the position away from the mesh film 1; alternatively, the circumferential outer contour of the carrier layer furthest from the grid film 1 is designed to be smaller than the circumferential outer contour of the first carrier layer 22, and the circumferential outer contour of the remaining layers is equal to the circumferential outer contour of the first carrier layer 22, so that a step structure is also formed between the carrier layer furthest from the grid film 1 and the carrier layer adjacent to the carrier layer. Therefore, when the adhesive overflows from the second end face 202 and then ascends along the outer side wall of the carrier 2, the adhesive is blocked from continuously crawling by the step face when climbing to the step structure, so that the condition that the adhesive pollutes the sound transmission area 12 of the grid membrane 1 is avoided to a great extent, and the airflow of the sound transmission area 12 is ensured.

In one embodiment, the carrier 2 is configured to be fixed on the grid film 1 in advance, and the outer contour and the opening 21 are formed by a photolithography process; the first carrier layer 22 and the second carrier layer 23 are formed by two photolithography processes, respectively.

The photoetching process specifically comprises the following steps: referring to fig. 4, a sacrificial layer b of organic material, a metal layer c and a carrier layer are sequentially stacked on a bottom plate a, the carrier layer is arranged opposite to a lithography apparatus, the carrier layer is etched by the lithography apparatus to obtain an outer contour of the carrier layer and the opening 21, and then the sacrificial layer b is removed and detached from the bottom plate a. Since the first carrier layer 22 and the second carrier layer 23 have different outline profiles, the first carrier layer 22 and the second carrier layer 23 are formed by two photolithography processes, respectively, so that the outline of the first carrier layer 22 in the circumferential direction of the columnar structure is larger than the outline of the second carrier layer 23 in the circumferential direction of the columnar structure.

Tapered photolithography structures having a complementary angle to the carrier 2 are formed on the mesh film 1 in advance, the carrier 2 is formed between the tapered photolithography structures, and the tapered photolithography structures are removed by a photolithography process.

In this embodiment, referring to fig. 5, a sacrificial layer b of organic material, a metal layer c and a tapered lithographic structure d having a complementary angle with respect to the carrier 2 are sequentially stacked on a base plate a, the tapered lithographic structure d is etched by a lithographic apparatus, the tapered lithographic structure d is removed, thus a reverse tapered carrier layer is formed, and finally the sacrificial layer b is removed and detached from the base plate a.

It should be noted that, when the carrier layer is formed by a photolithography process, a plurality of carrier layers of the dust-proof structure may be etched and formed simultaneously on one base plate a.

In one embodiment, the material of the carrier 2 is a metal material, and the carrier 2 is configured to be manufactured by a metal plating process, but is not limited to the metal plating process, such as a chemical deposition process, and the like, which is not limited by the present invention.

The embodiment of the utility model also provides a MEMS microphone packaging structure, it includes the shell 3 that has the holding chamber, be equipped with the sound hole 4 on the shell 3, the sound hole 4 communicates the inside and the outside of shell 3; the MEMS microphone packaging structure also comprises a microphone device and the dustproof structure, wherein the microphone device is fixedly arranged in the shell 3; an adhesive is coated between the second end face 202 of the carrier 2 and the shell, and the second end face 202 is fixedly bonded with the shell through a high-temperature bonding and curing process; the mesh membrane 1 closes the sound hole; and/or the mesh membrane is spaced between the sound aperture and the microphone device. In one embodiment, the sidewall of the carrier near the second end face 202 is an adhesive overflow surface having the adhesive thereon.

The MEMS microphone packaging structure can be applied to various electronic products such as mobile phones, notebook computers, Ipad and VR equipment and intelligent wearable equipment, and is widely applied. The embodiment of the utility model provides a MEMS microphone packaging structure can effectively avoid components and parts such as inside microphone device to receive the influence of particulate matter such as outside dust, impurity, foreign matter and suffer the phenomenon of destruction, can prolong the life of microphone, but also can make the microphone keep good acoustic performance.

Referring to fig. 6-10, the microphone package structure of the present invention has a structure of the housing 3: the substrate 32 and the packaging cover 31 are included, and the substrate 32 and the packaging cover 31 together enclose the accommodating cavity. The dust-proof structure is accommodated in the accommodating cavity of the housing 3. Specifically, the sound hole 4 is opened on the substrate 32, and the microphone device includes a MEMS chip 5 and a signal amplifier 6 connected thereto. The MEMS chip 5 comprises a substrate and an induction film, wherein the substrate is of a hollow structure. The sensing film is, for example, a piezoelectric element, a capacitive element, a piezoresistive element, or the like. The sensing film is arranged at one end of the substrate and covers the hollow structure of the substrate, the hollow structure forms a back cavity, the back cavity is communicated with the sound hole 4, and the MEMS chip 5 is attached to the substrate 32.

In an alternative example of the present invention, as shown in fig. 6, the dustproof structure is located in the accommodating cavity of the housing 3 and covers the sound hole 4, specifically, the carrier 2 is connected to the substrate 32 and surrounds the sound hole 4, and the mesh membrane 1 is disposed opposite to the sound hole 4 for blocking the outside dust, foreign matter, and other particles from entering the accommodating cavity of the housing 3 through the sound hole 4. In the embodiment shown in fig. 3, the dust-proof structure is entirely located in the back cavity of the MEMS chip 5, and the external air flow firstly enters the back cavity of the chip 5 after being filtered by the mesh membrane 1 of the dust-proof structure.

In an alternative example of the present invention, as shown in fig. 7, the dustproof structure is located in the accommodating cavity of the housing 3 and covers the sound hole 4, specifically, the carrier 2 is connected to the substrate 32 and surrounds the sound hole 4, and the mesh membrane 1 is disposed opposite to the sound hole 4 for blocking the outside dust, foreign matter, and other particles from entering the accommodating cavity of the housing 3 through the sound hole 4. In the embodiment shown in fig. 4, the MEMS chip 5 is connected to a side of the mesh membrane 1 of the dustproof structure away from the carrier 2, specifically, to a side of the fixed connection region 11 away from the carrier 2, and external air flows firstly pass through the filtering effect of the mesh membrane 1 of the dustproof structure and then enter the back cavity of the chip 5.

Of course, the utility model discloses a dustproof construction also can have other setting:

for example, as shown in fig. 8, the sound hole 4 is opened in the package cover 31, and the dust-proof structure cover is provided in the package cover 31 at a position corresponding to the sound hole 4 and outside the housing 3. For example, as shown in fig. 9, the sound hole 4 is opened in the package cover 31, and the dust-proof structure cover is provided in the package cover 31 at a position corresponding to the sound hole 4 and in the accommodation chamber of the housing 3. The position of dustproof construction corresponds to phonate hole 4, can avoid outside particulate matter, foreign matter to introduce inside microphone packaging structure through phonate hole 4. For another example, as shown in fig. 10, the sound hole 4 is located on the package cover 31, and the dust-proof structure is fixedly connected to the substrate 32 at a position corresponding to the sound hole 4, so that the dust-proof structure can effectively protect the microphone device in the microphone package structure.

Although certain specific embodiments of the present invention have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the 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 dustproof structure according to claim 1, wherein the carrier has a tapered columnar structure, and an area of the second end surface is smaller than an area of the first end surface.

3. The dustproof structure according to claim 1, wherein the carrier comprises at least two carrier layers, the first end face is located on a first carrier layer of the carrier layers, the first carrier layer is connected to one side of the fixed connection region, other carrier layers are sequentially stacked and distributed on one side of the first carrier layer away from the grid film along the thickness direction of the grid film, and the second end face is located on the carrier layer farthest away from the grid film;

4. The dustproof structure according to claim 3, wherein the outer contour of each of the carrier layers in the circumferential direction of the columnar structure decreases in a direction from near to far from the mesh film.

5. The dustproof structure according to claim 3, wherein the carrier is configured to be fixed on the mesh film in advance, and the outer contour and the opening are formed by a photolithography process;

the first carrier layer and the second carrier layer of the two carrier layers are formed by two times of photoetching processes respectively.

6. The dustproof structure according to claim 1, wherein the carrier is configured to be fixed on the mesh film in advance, and the outer contour and the opening are formed by a photolithography process.

7. The dust-proof structure according to any one of claims 1 to 6, wherein the material of the carrier is a metal material, and the carrier is configured to be manufactured using a metal plating process.

8. A MEMS microphone package structure, comprising:

a microphone device fixedly disposed within the housing;

the dust-proof structure of any one of claims 1-7, wherein an adhesive is applied between the second end surface of the carrier and the housing, and the second end surface is fixedly bonded to the housing by a high-temperature bonding and curing process;

9. The MEMS microphone package structure of claim 8, wherein a sidewall of the carrier proximate to the second end surface is an adhesive overflow surface having the adhesive thereon.