CN214544780U

CN214544780U - Microphone packaging structure and microphone system

Info

Publication number: CN214544780U
Application number: CN202023160067.1U
Authority: CN
Inventors: 缪建民; 钟华; 王刚
Original assignee: Huajing Technology Wuxi Co ltd
Current assignee: Huajing Technology Wuxi Co ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-10-29
Anticipated expiration: 2030-12-24

Abstract

The utility model discloses a microphone packaging structure and microphone system. The microphone packaging structure comprises a substrate, an MEMS chip, an ASIC chip and a protective shell; the MEMS chip and the ASIC chip are arranged on the substrate, the MEMS chip is electrically connected with the ASIC chip, and the ASIC chip is electrically connected with the substrate; the MEMS chip is used for converting an external sound signal into an electric signal, and the ASIC chip is used for processing the electric signal; the protective shell is positioned on the substrate and covers the MEMS chip and the ASIC chip; the protective shell comprises a through hole; the substrate comprises at least two hollow cavities, and the at least two hollow cavities are communicated with the back cavity of the MEMS chip. The embodiment of the utility model provides a technical scheme has improved microphone packaging structure's SNR.

Description

Microphone packaging structure and microphone system

Technical Field

The embodiment of the utility model provides a relate to microphone technical field, especially relate to a microphone packaging structure and microphone system.

Background

The volume of the micro-electromechanical microphone package is far smaller than that of the traditional electret microphone package, which is beneficial to the portable development of a microphone system and is popular with users.

At present, the sound inlet mode of the mems microphone includes front sound and back sound, wherein the signal-to-noise ratio of the front sound product is 3-4 dB lower than that of the back sound product due to the packaging structure, and is difficult to be improved to a higher level due to the structural limitation.

SUMMERY OF THE UTILITY MODEL

The utility model provides a microphone packaging structure and microphone system to improve microphone packaging structure's SNR.

In a first aspect, an embodiment of the present invention provides a microphone packaging structure, including:

the MEMS chip comprises a substrate, an MEMS chip, an ASIC chip and a protective shell;

the MEMS chip and the ASIC chip are arranged on the substrate, the MEMS chip is electrically connected with the ASIC chip, and the ASIC chip is electrically connected with the substrate; the MEMS chip is used for converting an external sound signal into an electric signal, and the ASIC chip is used for processing the electric signal;

the protective shell is positioned on the substrate and covers the MEMS chip and the ASIC chip; the protective shell comprises a through hole;

the substrate comprises at least two hollow cavities, and the at least two hollow cavities are communicated with the back cavity of the MEMS chip.

In a second aspect, an embodiment of the present invention further provides a microphone system, including the microphone package structure of the first aspect.

The microphone packaging structure provided by the embodiment of the utility model comprises a substrate, a MEMS chip, an ASIC chip and a protective shell, wherein the MEMS chip and the ASIC chip are arranged on the substrate, the MEMS chip is electrically connected with the ASIC chip, the ASIC chip is electrically connected with the substrate, the MEMS chip is used for converting external sound signals into electric signals, the ASIC chip is used for processing the electric signals, the protective shell is positioned on the substrate, and covers the MEMS chip and the ASIC chip, the protective shell comprises a through hole, the substrate comprises at least two hollow chambers, the at least two hollow chambers are communicated with the back cavity of the MEMS chip, the arrangement of the at least two hollow chambers increases the volume of the back cavity of the MEMS chip, and then the signal to noise ratio of the microphone is improved, and the spacing body between the at least two hollow cavities plays a supporting role, so that the hollow cavities are prevented from collapsing in the substrate pressing process and the MEMS chip surface mounting process, and the strength of the substrate and the microphone packaging structure is improved.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:

fig. 1 is a schematic diagram of a microphone package structure according to an embodiment of the present invention;

fig. 2 is a schematic top view of a substrate according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view taken along the dashed line AA in FIG. 2;

FIG. 4 is a schematic cross-sectional view taken along the dashed line BB in FIG. 2;

fig. 5 is a schematic diagram of another microphone package structure according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a microphone system according to an embodiment of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention for achieving the intended purpose of the present invention, the following detailed description will be given with reference to the accompanying drawings and preferred embodiments for describing the specific embodiments, structures, features and effects of a microphone package and a microphone system according to the present invention.

An embodiment of the utility model provides a microphone packaging structure, include:

The above is the core idea of the present application, and the technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, under the premise that creative work is not done by ordinary skilled in the art, all other embodiments obtained all belong to the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other embodiments that depart from the specific details disclosed herein, and one skilled in the art may readily devise many other varied embodiments that are not limited to the specific details disclosed herein.

Next, the present invention will be described in detail with reference to the schematic drawings, and in the detailed description of the embodiments of the present invention, for convenience of explanation, the schematic drawings showing the structure of the device are not partially enlarged according to the general scale, and the schematic drawings are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and height should be included in the actual fabrication.

Fig. 1 is a schematic diagram of a microphone package structure according to an embodiment of the present invention. As shown in fig. 1, the microphone package structure includes a substrate 100, a MEMS chip 200, an ASIC chip 300, and a protective case 400.

The MEMS chip 200 and the ASIC chip 300 are mounted on the substrate 100, the MEMS chip 200 is electrically connected to the ASIC chip 300, the ASIC chip 300 is electrically connected to the substrate 100, the MEMS chip 200 is used to convert an external sound signal into an electrical signal, and the ASIC chip is used to process the electrical signal. The protective case 400 is located on the substrate 100 and covers the MEMS chip 200 and the ASIC chip 300, the protective case 400 includes a through hole 410, the substrate 100 includes at least two hollow cavities 110, and the at least two hollow cavities 110 are in communication with the back cavity 210 of the MEMS chip 200.

Specifically, fig. 2 is a schematic top view of a substrate according to an embodiment of the present invention. Fig. 3 is a schematic cross-sectional view along the broken line AA in fig. 2. Fig. 4 is a schematic sectional view along a dotted line BB in fig. 2. As shown in fig. 2, 3 and 4, the substrate includes three hollow chambers 110, the three hollow chambers 110 are all communicated with the opening 101 on the upper surface of the substrate 100, in the mounting process of the MEMS chip, the MEMS chip covers the opening 101, the MEMS chip is supported by the spacers between the hollow chambers 110, the downward pressure acting on the MEMS chip cannot easily cause the hollow chamber 110 to collapse, and meanwhile, in the processing process of the substrate, the hollow chamber 110 cannot collapse due to the existence of the spacer support.

It should be noted that the MEMS chip includes a vibrating membrane, and external sound can reach the vibrating membrane through the through hole on the protective case, and change the distance between the vibrating membrane and the back plate, thereby forming a capacitance change, and the ASIC chip converts the capacitance change into a change of a voltage signal, and then outputs the voltage signal after amplification. Specifically, the voltage signal may be transmitted to the outside of the microphone package structure through a line on the substrate.

It should be noted that fig. 2 only illustrates 3 circular hollow chambers by way of example and is not limited thereto, and in other embodiments of this embodiment, the number and shape of the hollow chambers may be in other cases.

The microphone package structure provided by the embodiment comprises a substrate, a MEMS chip, an ASIC chip and a protective shell, wherein the MEMS chip and the ASIC chip are arranged on the substrate, the MEMS chip is electrically connected with the ASIC chip, the ASIC chip is electrically connected with the substrate, the MEMS chip is used for converting external sound signals into electric signals, the ASIC chip is used for processing the electric signals, the protective shell is positioned on the substrate, and covers the MEMS chip and the ASIC chip, the protective shell comprises a through hole, the substrate comprises at least two hollow chambers, the at least two hollow chambers are communicated with the back cavity of the MEMS chip, the arrangement of the at least two hollow chambers increases the volume of the back cavity of the MEMS chip, and then the signal to noise ratio of the microphone is improved, and the spacing body between the at least two hollow cavities plays a supporting role, so that the hollow cavities are prevented from collapsing in the substrate pressing process and the MEMS chip surface mounting process, and the strength of the substrate and the microphone packaging structure is improved.

With continued reference to fig. 1, the substrate 100 includes a first sub-substrate 121 and a second sub-substrate 122 stacked in sequence, the first sub-substrate 121 is located on one side of the second sub-substrate 122 close to the protective case 400, the first sub-substrate 121 includes an opening 102, the second sub-substrate 122 includes at least two grooves 103, the at least two grooves 103 and the first sub-substrate 121 form at least two hollow cavities 110, and the at least two hollow cavities 110 are communicated with the back cavity 210 of the MEMS chip through the opening 102.

Thus, the preparation process of the large-volume hollow chamber 110 with the smaller opening is simpler, only conventional groove preparation and plate adhesion are needed, no complex process is needed, and the size controllability of the hollow chamber is stronger.

Fig. 5 is a schematic diagram of another microphone packaging structure according to an embodiment of the present invention. As shown in fig. 5, on the basis of fig. 1, a step-up ring 500 is further disposed between the MEMS chip 200 and the substrate 100, and the back cavity 210 of the MEMS chip 200, the inner space of the step-up ring 500, and the at least two hollow cavities 110 communicate with each other.

It should be noted that the padding ring 500 is a ring structure, which can further increase the volume of the back cavity 210 of the MEMS chip 200, thereby achieving a higher signal-to-noise ratio.

It is understood that the electrical signal transmission between the MEMS chip 200 and the ASIC chip 300 is realized through the conductive wire 600 therebetween, and no electrical signal transmission exists between the MEMS chip and the ASIC chip and the substrate and the pad ring 500, so that the material of the pad ring 500 may be a conductive material or a non-conductive material, which is not limited in this embodiment. In addition, the height of the padding ring 500 can be set reasonably according to actual needs.

Optionally, the shape of the raised ring 500 is the same as the outer edge shape of the MEMS chip 200. In this way, the cross-sectional dimension of the inner space of the padding ring 500, which is communicated with the back cavity 210 of the MEMS chip 200, is the largest, which is beneficial to the increase of the size of the back cavity 210 of the MEMS chip 200.

For example, the material of the protective case 400 may be metal.

It should be noted that the metal has a high strength and can withstand a large impact, so as to prevent the MEMS chip 200 and the ASIC chip 300 from being damaged by an external force.

In the present embodiment, as shown in fig. 5, the MEMS chip 200 is electrically connected to the ASIC chip 300 through a wire 600, and the ASIC chip 300 is electrically connected to the substrate 100 through a wire 600.

It should be noted that the connection process of the wire 600 and the chip is simple, and can be realized only by a conventional soldering process, and the reliability is good, and in addition, the arrangement of the conductive 600 simplifies the circuit structure on the substrate 100, thereby simplifying the preparation process of the substrate.

Alternatively, the surface of the ASIC chip 300 remote from the substrate 100 may be provided with an adhesive film.

It should be noted that the raw material of the adhesive film may be glue, which can protect the solder joints in the ASIC chip and prevent dust.

Illustratively, the shape of the through-hole 410 may be circular.

It should be noted that the existing production line has a mature process for forming a circular through hole on a metal layer, and the circular shape of the through hole 410 is beneficial to simplifying the preparation process of the through hole 410.

Fig. 6 is a schematic structural diagram of a microphone system according to an embodiment of the present invention. As shown in fig. 6, the microphone system 10 includes a microphone package structure 11 according to any embodiment of the present invention. The embodiment of the utility model provides a microphone system 10 includes the utility model discloses the microphone packaging structure 11 of arbitrary embodiment has the utility model discloses the microphone packaging structure 11's that arbitrary embodiment provided technical characteristic, it has the same or corresponding beneficial effect of the microphone packaging structure 11 that it includes, and here is no longer repeated.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims

1. A microphone package structure, comprising:

2. The microphone packaging structure according to claim 1, wherein the substrate includes a first sub-substrate and a second sub-substrate stacked in sequence, the first sub-substrate being located on a side of the second sub-substrate close to the protective case; the first sub-substrate comprises an opening, the second sub-substrate comprises at least two grooves, the at least two grooves and the first sub-substrate form at least two hollow cavities, and the at least two hollow cavities are communicated with the back cavity of the MEMS chip through the opening.

3. The microphone package structure of claim 1, wherein a step-up ring is further disposed between the MEMS chip and the substrate, and the back cavity of the MEMS chip, the inner space of the step-up ring, and the at least two hollow cavities communicate.

4. The microphone package structure of claim 3, wherein the shape of the raised ring is the same as the shape of the outer edge of the MEMS chip.

5. The microphone packaging structure of claim 1, wherein the protective shell is made of metal.

6. The microphone package structure of claim 1, wherein the MEMS chip is electrically connected to the ASIC chip by a wire, and the ASIC chip is electrically connected to the substrate by a wire.

7. The microphone package structure of claim 1, wherein a surface of the ASIC chip away from the substrate is provided with an adhesive film.

8. The microphone package structure of claim 1, wherein the through hole is circular in shape.

9. A microphone system comprising the microphone package structure of any one of claims 1 to 8.