MEMS microphone and electronic device

Abstract

The utility model provides an MEMS microphone and an electronic device. The MEMS microphone comprises: a substrate; the MEMS chip is arranged on the substrate; the audio signal processing chip is arranged on the MEMS chip and is electrically connected with the MEMS; and the plastic package body is arranged on the substrate and covers the MEMS chip and the audio signal processing chip. According to the scheme, the audio signal processing chip is arranged on the MEMS chip, so that the packaging size of the MEMS microphone can be reduced, the cost can be further reduced, meanwhile, the electric signal transmission distance between the MEMS chip and the audio signal processing chip can be reduced, the loss of electric signals in the transmission process can be further reduced, and the performance of the MEMS microphone is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, and in particular to a MEMS microphone and an electronic device. Background Art

[0002] With the continuous development of semiconductor technology, smart phones, integrated CMOS and micro-electromechanical systems (MEMS) devices are becoming the most mainstream and advanced technologies in the sensor product market, and with the update of technology, they are developing in the direction of small size, high performance and low power consumption. Among them, MEMS microphones prepared based on micro-electromechanical systems (MEMS) technology are widely used because of their advantages of small size, low cost and stable performance compared with traditional microphones.

[0003] However, the package size of the MEMS microphone in the related art is relatively large, resulting in increased costs; and the electrical signal transmission distance between the MEMS chip and the audio signal processing chip is relatively far, resulting in greater loss of the electrical signal during transmission. Utility Model Content

[0004] A series of simplified concepts are introduced in the utility model content section, which will be further described in detail in the detailed implementation section. The utility model content section of the utility model does not mean to attempt to define the key features and essential technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

[0005] In order to at least partially solve the above technical problems, the utility model provides a MEMS microphone, comprising:

[0006] substrate;

[0007] A MEMS chip is disposed on the substrate;

[0008] An audio signal processing chip, disposed on the MEMS chip and electrically connected to the MEMS;

[0009] The plastic package is arranged on the substrate and covers the MEMS chip and the audio signal processing chip.

[0010] Exemplarily, a sound hole is formed in the substrate and passes through the substrate, a first cavity is formed in the MEMS chip, the first cavity is connected to the sound hole, a second cavity is formed in the audio signal processing chip, and the MEMS chip and the audio signal processing chip are joined on one side where the second cavity is formed.

[0011] Exemplarily, a first shielding layer is further included, wherein the first shielding layer covers the bottom and side walls of the second cavity.

[0012] Exemplarily, the first shielding layer is electrically connected to a ground layer on the substrate.

[0013] Exemplarily, the audio signal processing chip is electrically connected to the MEMS chip via a first conductive bump.

[0014] Exemplarily, a second shielding layer is further included, and the second shielding layer covers at least a portion of the outer surface of the plastic package body.

[0015] Exemplarily, the MEMS chip and the audio signal processing chip are electrically connected to the substrate via leads.

[0016] Exemplarily, the MEMS chip and the audio signal processing chip are electrically connected to the substrate via second conductive bumps.

[0017] Exemplarily, the audio signal processing chip includes an ASIC chip.

[0018] Another aspect of the present invention provides an electronic device, wherein the electronic device comprises the above-mentioned MEMS microphone.

[0019] In the MEMS microphone and electronic device of the utility model, the audio signal processing chip is arranged on the MEMS chip, which can reduce the packaging size of the MEMS microphone and thus reduce the cost. At the same time, it can reduce the electrical signal transmission distance between the MEMS chip and the audio signal processing chip, and thus reduce the loss of the electrical signal during the transmission process, thereby improving the performance of the MEMS microphone. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following drawings of the present invention are used as a part of the present invention for understanding the present invention. The drawings show the embodiments of the present invention and their descriptions, and are used to explain the principle of the present invention.

[0021] In the attached figure:

[0022] Figure 1 A schematic diagram showing the structure of a MEMS microphone of related art is shown;

[0023] Figure 2A A schematic diagram of the structure of a MEMS microphone according to a specific embodiment of the present invention is shown;

[0024] Figure 2B A structural schematic diagram of a MEMS microphone according to another specific embodiment of the utility model is shown. DETAILED DESCRIPTION

[0025] Next, the utility model will be described more completely in conjunction with the accompanying drawings, in which embodiments of the utility model are shown. However, the utility model can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and fully convey the scope of the utility model to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0026] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0027] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0028] Embodiments of the utility model are described herein with reference to cross-sectional views that are schematic diagrams of ideal embodiments (and intermediate structures) of the utility model. In this way, variations from the shapes shown due to, for example, manufacturing techniques and / or tolerances can be expected. Therefore, embodiments of the utility model should not be limited to the specific shapes of the zones shown herein, but include shape deviations due to, for example, manufacturing. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges, rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to show the actual shape of the region of the device and are not intended to limit the scope of the utility model.

[0029] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by ordinary technicians in the field of the utility model. It will also be understood that terms such as those defined in commonly used dictionaries should be understood to have the same meaning as they have in the context of the relevant field and / or this specification, and should not be interpreted in an ideal or overly formal sense unless expressly defined herein.

[0030] In related technologies, such as Figure 1 As shown, the MEMS microphone generally includes a substrate 110, a MEMS chip 120, an audio signal processing chip 130 and a housing 140. The audio signal processing chip 130 is wrapped by a plastic package 150, and the housing 140 and the substrate 110 form a receiving space.

[0031] Among them, the MEMS chip 120, the audio signal processing chip 130 and the substrate 110 are electrically connected through leads, and the MEMS chip 120 and the audio signal processing chip 130 are arranged on the substrate 110 at intervals. This planar structure will cause the MEMS package size to be larger, which will lead to increased costs; at the same time, the length of the leads between the MEMS chip 120 and the audio signal processing chip 130 is longer, resulting in a longer distance for the electrical signal transmission between the MEMS chip 120 and the audio signal processing chip 130, which will lead to greater losses of the electrical signals during transmission.

[0032] Therefore, in view of the existence of the above-mentioned technical problems, the utility model proposes a MEMS microphone, comprising:

[0033] substrate;

[0034] A MEMS chip is disposed on the substrate;

[0035] An audio signal processing chip, disposed on the MEMS chip and electrically connected to the MEMS;

[0036] The plastic package is arranged on the substrate and covers the MEMS chip and the audio signal processing chip.

[0037] In the MEMS microphone of the utility model, the audio signal processing chip is arranged on the MEMS chip, which can reduce the packaging size of the MEMS microphone and thus reduce the cost. At the same time, it can reduce the electrical signal transmission distance between the MEMS chip and the audio signal processing chip and thus reduce the loss of the electrical signal during the transmission process, thereby improving the performance of the MEMS microphone.

[0038] Embodiment 1

[0039] Below, reference Figure 2A and Figure 2B The MEMS microphone in the embodiment of the present application is described. Figure 2A A schematic diagram of the structure of a MEMS microphone according to a specific embodiment of the present invention is shown. Figure 2B A structural schematic diagram of a MEMS microphone according to another specific embodiment of the utility model is shown.

[0040] In one example, if Figure 2A and Figure 2B As shown, the MEMS microphone includes a substrate 210, a MEMS chip 220 is arranged on the substrate 210, an audio signal processing chip 230 is arranged on the MEMS chip 220 and is electrically connected to the MEMS chip 220, and a plastic package 240 is arranged on the substrate 210 and covers the MEMS chip 220 and the audio signal processing chip 230. Exemplarily, the plastic package 240 is used to provide heat insulation, and its material can be various materials commonly used in the art that can perform heat insulation, for example, polyethylene terephthalate (PET), ethylene-vinyl acetate copolymer (PE) or polyethylene (EVA), but is not limited to the above materials. Exemplarily, the plastic package 240 can be formed by a plastic packaging process. Exemplarily, the substrate 210 includes a mounting area and an electrical connection area, and the MEMS chip 220 is mounted on the mounting area of ​​the substrate 210.

[0041] In one example, compared to a packaging structure in which both an audio signal processing chip and a MEMS chip are arranged on a substrate, the MEMS chip 220 in the present application is arranged on a substrate 210, and the audio signal processing chip 230 is arranged on the MEMS chip 220 and electrically connected to the MEMS chip 220, which can reduce the packaging size of the MEMS microphone and thereby reduce the packaging cost of the MEMS microphone; at the same time, the audio signal processing chip 230 and the MEMS chip 220 are stacked, which can greatly reduce the electrical signal transmission distance between the two and thereby reduce the loss of electrical signals during transmission.

[0042] In one example, if Figure 2A and Figure 2B As shown, a sound hole 211 penetrating the substrate 210 is formed in the substrate 210, a first cavity 221 is formed in the MEMS chip 220, the first cavity 221 is connected to the sound hole 211, a second cavity 231 is formed in the audio signal processing chip 230, and the MEMS chip 220 and the audio signal processing chip 230 are joined at one side where the second cavity 231 is formed.

[0043] In one example, the MEMS chip 220 and the audio signal processing chip 230 both include a substrate, and the substrate may include at least one of the following materials: Si, Ge, SiGe, SiC, SiGeC, InAs, GaAs, InP, InGaAs or other III / V compound semiconductors, or the substrate may also include silicon on insulator (SOI), stacked silicon on insulator (SSOI), stacked silicon germanium on insulator (S-SiGeOI), silicon germanium on insulator (SiGeOI) or germanium on insulator (GeOI). Although several examples of materials that can form the substrate are described herein, any material that can be used as the substrate falls within the spirit and scope of the present application. Exemplarily, the substrate of the audio signal processing chip 230 can be etched using a conventional etching process in the art to form the second cavity 231.

[0044] In one example, the sound hole 211 is a channel for the external sound signal to act on the MEMS chip 220. The MEMS chip 220 also includes a diaphragm and a back plate. The diaphragm and the back plate form a parallel plate capacitor structure. The first cavity 221 exposes the diaphragm in the MEMS chip 220. When the external sound signal acts on the diaphragm in the MEMS chip 220 through the sound hole 211 and the first cavity 221, the diaphragm vibrates under the action of the external sound signal, so that the distance between the diaphragm and the back plate changes, thereby generating a change in capacitance, and using the capacitance to perform calculations and work to complete the conversion of sound signals and electrical signals. The audio signal processing chip 230 is electrically connected to the MEMS chip 220 to amplify the electrical signal generated by the MEMS chip 220, and also provides a bias voltage for the operation of the MEMS chip 220. At the same time, the audio signal processing chip 230 is also electrically connected to the substrate 210, and the substrate 210 is electrically connected to the external circuit. For example, the substrate 210 can be electrically connected to an external PCB board to transmit the electrical signal to the external circuit.

[0045] In one example, the audio signal processing chip 230 includes an application specific integrated circuit (ASIC) chip.

[0046] In one example, the operation of the MEMS chip 220 requires a front cavity (Front volume) and a back cavity (Back volume), wherein the front cavity directly faces the external sound signal, and the first cavity 221 in the present application is the front cavity, and the back cavity is located on the other side of the diaphragm, and the second cavity 231 formed in the audio signal processing chip 230 in the present application is the back cavity, so there is no need to form an additional cavity as the back cavity, which can effectively reduce the packaging process and reduce the packaging size, thereby reducing the packaging cost.

[0047] In one example, the volume and shape of the first cavity 221 as the front cavity mainly affect the sensitivity and frequency response characteristics of the MEMS microphone, and the volume and shape of the second cavity 231 as the back cavity mainly affect the signal-to-noise ratio (SNR) and overall sound quality of the MEMS microphone.

[0048] In one example, if Figure 2A and Figure 2B As shown, the MEMS microphone of the present application further includes a first shielding layer 250, and the first shielding layer 250 covers the bottom and side walls of the second cavity. The first shielding layer can be used to shield electromagnetic waves in the external environment, thereby preventing electromagnetic waves in the external environment from affecting the normal operation of the MEMS chip 220 and the audio signal processing chip 230. Exemplarily, the first shielding layer 250 can be formed by a deposition process commonly used in the art, for example, the first shielding layer 250 can be formed by a sputtering process. Exemplarily, the material of the first shielding layer 250 can be any material that can shield electromagnetic explosions in the external environment, for example, it can be metal, ferrite, electromagnetic shielding film, conductive foam, conductive plastic, etc.

[0049] In one example, the first shielding layer 250 is electrically connected to the ground layer on the substrate 210 so that the first shielding layer 250 is grounded to achieve the electromagnetic shielding function of the first shielding layer 250. Exemplarily, the ground layer on the substrate 210 refers to a layer on the substrate 210 that is connected to the ground line in the external circuit. Exemplarily, the first shielding layer 250 can be electrically connected to the ground layer on the substrate 210 through a structure such as a lead or a conductive bump.

[0050] In one example, if Figure 2A and Figure 2BAs shown, the MEMS microphone of the present application also includes a second shielding layer 260, which covers at least part of the surface of the plastic package 240, and the second shielding layer 260 is also used to shield electromagnetic waves in the external environment. Exemplarily, the first shielding layer 250 and the second shielding layer 260 are used together to shield electromagnetic waves in the external environment, so that a double shielding effect can be achieved, thereby greatly increasing the anti-electromagnetic wave interference capability of the MEMS microphone. Exemplarily, the second shielding layer 260 covers the entire surface of the plastic package 240. Exemplarily, the second shielding layer 260 can be formed by a deposition process commonly used in the art, for example, the second shielding layer 260 can be formed by a sputtering process. Exemplarily, the material of the second shielding layer 260 can be any material that can shield electromagnetic explosions in the external environment, for example, it can be metal, ferrite, electromagnetic shielding film, conductive foam, conductive plastic, etc. Exemplarily, the first shielding layer 250 and the second shielding layer 260 have the same material or different materials. Exemplarily, the second shielding layer 260 is also electrically connected to the grounding layer on the substrate 210 so that the second shielding layer 260 is grounded to achieve the electromagnetic shielding function of the second shielding layer 260. In some embodiments, the second shielding layer 260 can be a metal shell. When the second shielding layer 260 is a metal shell, the inner surface of the metal shell contacts the outer surface of the plastic package 240 or there is a gap between the inner surface of the metal shell and the outer surface of the plastic package 240.

[0051] In one example, if Figure 2A and Figure 2B As shown, the audio signal processing chip 230 is electrically connected to the MEMS chip through the first conductive bump 270. More specifically, the audio signal processing chip 230 is electrically connected to the MEMS chip through multiple first conductive bumps 270. The first conductive bumps 270 are arranged on the outside of the second cavity 231. The first conductive bumps 270 can greatly shorten the transmission path of the electrical signal, thereby reducing the loss of the electrical signal during the transmission process and reducing the signal delay. Exemplarily, the first conductive bumps 270 are arranged at the input and output ports of the audio signal processing chip 230. Exemplarily, a bumping process can be used to form multiple first conductive bumps 270. In other embodiments, other processes can also be used to form the first conductive bumps 270, and this application does not limit this. Exemplarily, the material of the first conductive bumps 270 can be any suitable material that can transmit electrical signals, such as tin, gold, copper-nickel alloy, etc. Exemplarily, the plastic package 240 also fills the gaps between the multiple first conductive bumps 270.

[0052] In one example, if Figure 2A As shown, the MEMS chip 220 and the audio signal processing chip 230 are electrically connected to the substrate 210 through the lead 280. More specifically, as Figure 2AAs shown, the two ends of the lead 280 are respectively connected to the MEMS chip 220 and the substrate 210, and at the same time the audio signal processing chip 230 is electrically connected to the MEMS chip 220, so the audio signal processing chip 230 can also be electrically connected to the substrate 210 through the lead 280. Exemplarily, the lead 280 electrically connecting the MEMS chip 220 and the substrate 210 can be formed by a wire bonding (Wire Bonding, WB) process. Exemplarily, the material of the lead 280 can be any suitable material that can transmit electrical signals, such as copper, silver, etc.

[0053] In another example, Figure 2B As shown, the MEMS chip 220 and the audio signal processing chip 230 are electrically connected to the substrate 210 via the second conductive bumps 290. More specifically, as Figure 2B As shown, the audio signal processing chip 230 is electrically connected to the substrate 210 through the second conductive bumps 290, and at the same time the MEMS chip 220 is electrically connected to the audio signal processing chip 230, so the MEMS chip 220 can also be electrically connected to the substrate 210 through the second conductive bumps 290. Exemplarily, in order to achieve direct electrical connection to the substrate 210 through the second conductive bumps 290, the audio signal processing chip 230 located on the MEMS chip 220 has a more outward protruding portion relative to the outer side wall of the MEMS chip 220, and the second conductive bumps 290 are formed on the protruding portion. Exemplarily, the MEMS chip 220 can be first welded to the audio signal processing chip 230, and then the flip chip (FC) welding process is used to "invert" the audio signal processing chip to the substrate 210 to achieve electrical connection between the audio signal processing chip 230 and the substrate 210. Specifically, a second conductive bump 290 is made on the audio signal processing chip 230, and then the audio signal processing chip 230 is inverted so that the second conductive bump 290 is aligned with the substrate 210, and then the second conductive bump 290 is welded to the substrate 210 to achieve electrical connection between the audio signal processing chip 230 and the substrate 210. In other embodiments, other processes can also be used to form the second conductive bump 290, and this application is not limited to this. Exemplarily, the material of the second conductive bump 290 can be any suitable material that can transmit electrical signals, such as lead-tin alloy, copper-nickel alloy, etc. Exemplarily, the plastic package 240 also fills the gaps between the second conductive bumps 290 , the MEMS chip 220 , and the audio signal processing chip 230 .

[0054] The structure of the MEMS microphone of the present invention has been introduced so far. A complete MEMS microphone may also include other components, which will not be described in detail here.

[0055] In summary, in the MEMS microphone of the utility model, the audio signal processing chip is arranged on the MEMS chip, which can reduce the package size of the MEMS microphone, thereby reducing the cost, and at the same time can reduce the electrical signal transmission distance between the MEMS chip and the audio signal processing chip, thereby reducing the loss of the electrical signal during the transmission process, thereby improving the performance of the MEMS microphone. Exemplarily, the second cavity in the audio signal processing chip serves as the back cavity of the MEMS chip, and there is no need to form an additional cavity, which can further reduce the package size of the MEMS microphone. Exemplarily, a first shielding layer and a second shielding layer are formed, which can form a double shielding effect against external electromagnetic waves, greatly increasing the MEMS microphone's ability to resist electromagnetic interference.

[0056] Embodiment 2

[0057] Refer to the following Figure 2A and Figure 2B The manufacturing method of the MEMS microphone of the present application is described below.

[0058] In one example, the following steps can be used to form Figure 2A and Figure 2B The audio signal processing chip 230 shown in the figure: first, a substrate is provided; then, the audio signal processing chip 230 is formed on the substrate by etching and deposition processes, and at the same time, the position of the cavity 231 to be formed is planned on the audio signal processing chip 230; then, the cavity 231 is formed by etching at the position of the cavity to be formed. Exemplarily, after the cavity 231 is formed, a first shielding layer 250 covering the bottom and sidewalls of the cavity 231 can be formed by a sputtering process. Exemplarily, after the cavity 231 is formed, a deposition process (e.g., a bump process) is used to form a first conductive bump 270 around the cavity 231 and at the input and output ports of the audio signal processing chip 230.

[0059] In one example, if Figure 2A As shown, after the audio signal processing chip 230 is processed, the audio signal processing chip 230 is mounted on the MEMS chip 220, and the first conductive bump 270 is welded to the MEMS chip 220 to form an electrical connection, and the MEMS chip 220 has been mounted on the substrate 210 before being mounted on the audio signal processing chip 230; then, a lead 280 electrically connecting the substrate 210 and the MEMS chip 220 is formed by wire bonding to achieve electrical connection between the substrate 210, the MEMS chip 220 and the audio signal processing chip 230, and at the same time, the first shielding layer 250 can be electrically connected to the ground layer on the substrate 210 through the lead to achieve electromagnetic wave shielding function; finally, a plastic encapsulation body 240 is formed by a plastic encapsulation process, and a second shielding layer 260 is formed by a sputtering process, and the result is as shown in FIG. Figure 2AThe MEMS microphone shown.

[0060] In another example, Figure 2B As shown, after the audio signal processing chip 230 is processed, the MEMS chip 220 is first mounted on the audio signal processing chip 230, and the first conductive bump 270 is welded to the MEMS chip 220 to form an electrical connection; then, the second conductive bump 290 is made on the audio signal processing chip 230, and then the audio signal processing chip 230 is inverted so that the second conductive bump 290 is aligned with the substrate 210, and then the second conductive bump 290 is welded to the substrate 210 to achieve the electrical connection between the audio signal processing chip 230 and the substrate 210, and at the same time, the first shielding layer 250 can also be electrically connected to the ground layer on the substrate 210 through other conductive bumps to achieve the electromagnetic wave shielding function; finally, the plastic packaging body 240 is formed by a plastic packaging process, and the second shielding layer 260 is formed by a sputtering process, and the result is as shown in FIG. Figure 2B The MEMS microphone shown.

[0061] The key steps of the method for manufacturing the MEMS microphone of the present application have been described so far. The manufacturing of a complete MEMS microphone may also include other steps, which will not be described one by one here. It is worth mentioning that the order of the above steps can be adjusted without conflict.

[0062] Embodiment 3

[0063] Another embodiment of the present invention provides an electronic device including the above-mentioned MEMS microphone.

[0064] The electronic device of this embodiment can be any electronic product or device such as a mobile phone, a tablet computer, a laptop computer, a netbook, a game console, a television, a VCD, a DVD, a navigator, a camera, a video camera, a voice recorder, an MP3, an MP4, a PSP, etc., or any intermediate product including the MEMS microphone. The electronic device of this embodiment of the utility model has better performance due to the use of the above-mentioned MEMS microphone.

[0065] Although multiple embodiments are described herein, it should be understood that a variety of other modifications and embodiments may be conceived by those skilled in the art, all of which will fall within the spirit and scope of the concepts disclosed in the present utility model. More particularly, within the scope of the present utility model disclosure, the accompanying drawings, and the appended claims, various modifications and changes may be made in the arrangement and / or components of the combined arrangement of the subject matter. In addition to modifications and changes to the components and / or arrangements, the use of alternatives is also an obvious choice for those skilled in the art.

Claims

1. A MEMS microphone, characterized in that: include: substrate; A MEMS chip is disposed on the substrate; An audio signal processing chip, disposed on the MEMS chip and electrically connected to the MEMS; The plastic package is arranged on the substrate and covers the MEMS chip and the audio signal processing chip.

2. The MEMS microphone according to claim 1, characterized in that: The substrate has an acoustic hole formed therein and passing through the substrate, the MEMS chip has a first cavity formed therein and the first cavity is connected to the acoustic hole, the audio signal processing chip has a second cavity formed therein, and the MEMS chip is joined to a side of the audio signal processing chip where the second cavity is formed.

3. The MEMS microphone according to claim 2, characterized in that: The invention also includes a first shielding layer, wherein the first shielding layer covers the bottom and side walls of the second cavity.

4. The MEMS microphone according to claim 3, characterized in that: The first shielding layer is electrically connected to a ground layer on the substrate.

5. The MEMS microphone according to claim 1, characterized in that: The audio signal processing chip is electrically connected to the MEMS chip via a first conductive bump.

6. The MEMS microphone according to claim 1, characterized in that: It also includes a second shielding layer, which covers at least a portion of the outer surface of the plastic package body.

7. The MEMS microphone according to claim 1, characterized in that: The MEMS chip and the audio signal processing chip are electrically connected to the substrate through leads.

8. The MEMS microphone according to claim 1, characterized in that: The MEMS chip and the audio signal processing chip are electrically connected to the substrate via second conductive bumps.

9. The MEMS microphone according to claim 1, characterized in that: The audio signal processing chip includes an ASIC chip.

10. An electronic device, characterized in that: The electronic device comprises the MEMS microphone according to any one of claims 1 to 9.

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