CN211328635U

CN211328635U - Micro-filter and MEMS sensor assembly

Info

Publication number: CN211328635U
Application number: CN201921870566.4U
Authority: CN
Inventors: 林育菁
Original assignee: Goertek Microelectronics Inc
Current assignee: Goertek Microelectronics Inc
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-08-25
Anticipated expiration: 2029-10-31

Abstract

A first aspect of the present disclosure provides a microfilter comprising: a carrier (201) having a through cavity (205) formed therein and penetrating in a thickness direction thereof; and a filter membrane (202) overlying the carrier (201) and covering an opening through the cavity (205). The carrier (201) also has a through-groove (203) formed therein that passes through in its thickness direction, the through-groove (203) surrounding the through-cavity (205) and not intersecting the through-cavity (205). A second aspect of the present disclosure also provides a MEMS sensor assembly.

Description

Micro-filter and MEMS sensor assembly

Technical Field

The present disclosure generally relates to a microfilter, which may be a microfilter suitable for use in an acoustic device for filtering dust, particles and/or water and the like that are not intended to enter the interior of the acoustic device. The present disclosure also relates to a MEMS sensor assembly.

Background

Portable computing devices such as notebook computers, tablet computers, and the like are common today, as are portable communication devices such as smart phones. However, the internal space left for the microphone or speaker in such devices is quite limited. Therefore, the microphones and speakers are getting smaller and more compact. Furthermore, since microphones and speakers are deployed in compact portable devices, they typically require proximity to the associated acoustic input or output ports of the device, and are susceptible to failure of the MEMS sensor components therein due to ingress of particles and water.

In the prior art, particle filters (also known as PB chips, micro filters) are often deployed in MEMS sensor components to prevent certain types of debris from entering therein. To install the microfilter in the MEMS sensor assembly, an adhesive is typically used. However, in the conventional mounting method, an adhesive needs to be applied to the side surface of the micro-filter, which inevitably increases the mounting area.

Therefore, a micro filter structure capable of reducing an installation area while securing a firm installation is required.

SUMMERY OF THE UTILITY MODEL

It is an object of the present disclosure to provide a new solution for a microfilter.

According to a first aspect of the present disclosure, there is provided a microfilter comprising: a carrier having a through cavity formed therein and penetrating in a thickness direction thereof; and a filter membrane superposed on the bearing member and covering one opening of the through cavity; characterized in that the carrier further has a through-groove formed therein which runs through in its thickness direction, said through-groove surrounding the through-cavity and having no intersection with the through-cavity.

Optionally, the opening of the through-channel is continuous and surrounds the opening of the through-cavity.

Optionally, the opening of the through-groove is discontinuous and surrounds the opening of the through-cavity.

Optionally, the opening of the through groove is annular, and the opening of the through cavity is circular.

Optionally, the carrier is made of a polymeric or metallic material.

According to a second aspect of the present disclosure, there is provided a MEMS sensor assembly, comprising: a microfilter according to the first aspect of the present disclosure; and a MEMS sensor having an opening therein and capable of sensing through the opening; the micro filter is mounted on the MEMS sensor via a PCB in a manner covering the opening by means of an adhesive applied in the bottom surface of the carrier and the through groove.

Optionally, the adhesive is a curable adhesive.

Optionally, the MEMS sensor component is used in a microphone module or a microphone chip.

In one embodiment of the present disclosure, lateral sliding of the microfilter is prevented without applying adhesive to the sides of the carrier, thereby reducing the mounting area while ensuring secure mounting.

Other features of the present disclosure 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 the specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

FIG. 1 schematically illustrates a cross-sectional view of a prior art microfilter;

figure 2 schematically illustrates a cross-sectional view of a microfilter according to one embodiment of the present disclosure.

Detailed Description

Various exemplary embodiments of the present disclosure 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 disclosure 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 disclosure, 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 present disclosure provides a micro-filter and a MEMS sensor assembly using the same. The MEMS sensor component may be used in an acoustic device, which may be, for example, a microphone chip, or a microphone module. For example, when the acoustic device is a microphone chip, the MEMS sensor component may be disposed on the microphone chip; when the acoustic device is a microphone module, the MEMS sensor component may be disposed at an acoustic aperture on a housing or shell of the microphone module. Of course, it will be apparent to those skilled in the art that the acoustic device may be other types of acoustic transducers and will not be described in detail herein.

Figure 1 schematically shows a cross-sectional view of a prior art microfilter. As shown in fig. 1, the prior art microfilter includes a carrier 101, and the carrier 101 has a through cavity 105 formed therein through the thickness direction of the carrier 101. The carrier may be made of a polymeric material or a metallic material. When the carrier is made of a polymer material, it can be manufactured by a photolithography process. When the bearing member is made of a metal material, the bearing member may be manufactured by electroplating or electroless deposition.

The through cavity 105 has two opposing openings, each opening being located on one of the two opposing surfaces (top and bottom) of the carrier 101. A filter membrane 102 is stacked on the carrier 101, the filter membrane 102 covering an opening of the through-cavity 105. Through holes 107 may be arranged on the part of the filter membrane 102 covering the opening.

In order to mount the microfilter in place, it is generally necessary to employ an adhesive 109, preferably a curable adhesive. In order to ensure a stable mounting of the microfilter, it is necessary to apply an adhesive not only on the bottom surface of the carrier 101, but also on the side surfaces of the carrier 101 to prevent lateral sliding of the carrier 101, as shown in fig. 1. However, applying the adhesive on the side face necessarily leads to an increase in the mounting area. As shown in fig. 1, the mounting area is significantly larger than the bottom area of the carrier 101.

Figure 2 schematically illustrates a cross-sectional view of a microfilter according to one embodiment of the present disclosure. As shown in fig. 2, the microfilter according to the present disclosure also includes a carrier 201 and a filter membrane 202. The carrier 201 has a through cavity 205 formed therein through the thickness direction of the carrier 201. The through cavity 205 has two opposing openings, each opening being located on one of the two opposing surfaces of the carrier 201.

A filter membrane 202 is superimposed on the carrier 201, the filter membrane 202 covering one of the two openings through the cavity 205. Through holes 207 may be arranged on the part of the filter membrane 202 covering said opening. The carrier 201 also has a through groove 203 formed therein that penetrates in the thickness direction of the carrier 201. The through-channels 203 surround the through-cavities 205 and do not intersect the through-cavities 205.

It will be appreciated by those skilled in the art that the through-channels 203 may be continuous or discontinuous channels that surround a cylindrical through-cavity 205. Preferably, the through groove 203 may be an annular groove. The through-groove 203 also has two openings, wherein the openings on the surface of the carrier 201 that is covered with the filter membrane (the upper surface shown in fig. 2) are also covered with the filter membrane 202.

The microfilter in the embodiment of fig. 2 is mounted on the MEMS sensor (not shown) via a Printed Circuit Board (PCB) by means of an adhesive 209 applied onto the bottom surface (the surface in contact with the mounting plane) of the carrier 201 and into the through-going groove 203, the adhesive 209 being a curable adhesive. The MEMS sensor may have an opening and sensing is performed through the opening, and the micro filter is mounted on a PCB mounted on the MEMS sensor in a manner to cover the opening. The structure of the microfilter in fig. 2 enables the curable adhesive 209 to enter the through-channels 203, which adhesive after curing acts as an "anchor" preventing the lateral sliding of the carrier 201 along the mounting plane by the anchoring effect, while at the same time enlarging the adhesion area.

As shown in fig. 2, the micro-filter structure according to the present disclosure can prevent lateral sliding of the micro-filter without applying an adhesive on the side of the carrier 201, significantly reducing the installation area compared to the prior art. As shown in fig. 2, the mounting area is the same as the bottom area of the carrier 201.

Although some specific embodiments of the present disclosure 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 present disclosure. 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 disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A microfilter, comprising:

a carrier having a through cavity formed therein and penetrating in a thickness direction thereof; and

a filter membrane superposed on the bearing member and covering one opening of the through cavity;

characterized in that the carrier further has a through-groove formed therein which runs through in its thickness direction, said through-groove surrounding the through-cavity and having no intersection with the through-cavity.

2. The microfilter of claim 1, wherein the opening of the through channel is continuous and surrounds the opening of the through cavity.

3. The microfilter of claim 1, wherein the opening of the through channel is discontinuous and surrounds the opening of the through cavity.

4. The microfilter of claim 2, wherein the opening of the through channel is annular and the opening of the through cavity is circular.

5. The microfilter of claim 1, wherein the carrier is made of a polymeric or metallic material.

6. A MEMS sensor assembly, comprising:

the microfilter of any of claims 1 to 5, and

a MEMS sensor having an opening therein and capable of sensing therethrough;

the micro filter is mounted on the MEMS sensor via a PCB in a manner covering the opening by means of an adhesive applied in the bottom surface of the carrier and the through groove.

7. The MEMS sensor assembly of claim 6, wherein the adhesive is a curable adhesive.

8. The MEMS sensor component according to claim 6 or 7, wherein the MEMS sensor component is used in a microphone module or a microphone chip.