CN112995868A - MEMS microphone and electronic device - Google Patents

MEMS microphone and electronic device Download PDF

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Publication number
CN112995868A
CN112995868A CN202110203364.XA CN202110203364A CN112995868A CN 112995868 A CN112995868 A CN 112995868A CN 202110203364 A CN202110203364 A CN 202110203364A CN 112995868 A CN112995868 A CN 112995868A
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CN
China
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channel
sound
pcb
mems microphone
mems
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CN202110203364.XA
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Chinese (zh)
Inventor
徐超
王顺
金龙
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Goertek Microelectronics Inc
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Goertek Microelectronics Inc
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Priority to CN202110203364.XA priority Critical patent/CN112995868A/en
Publication of CN112995868A publication Critical patent/CN112995868A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R19/00—Electrostatic transducers
    • H04R19/04—Microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/12—Sanitary or hygienic devices for mouthpieces or earpieces, e.g. for protecting against infection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/003—Mems transducers or their use

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Manufacturing & Machinery (AREA)
  • Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)

Abstract

The invention discloses an MEMS microphone and an electronic device, wherein the MEMS microphone comprises a PCB (printed Circuit Board), a shell and an MEMS chip; the PCB is provided with a bottom surface, a top surface and side surfaces arranged along the periphery of the bottom surface and the top surface; the PCB is provided with a sound inlet channel, the sound inlet channel is provided with a channel inlet and a channel outlet, the channel inlet is formed on the side surface, and the channel outlet is formed on the top surface; the shell covers the top surface of the PCB to form a packaging cavity with the PCB in a surrounding manner; the MEMS chip is arranged in the packaging cavity and connected with the PCB, and the MEMS chip covers the sound channel outlet so as to communicate the back cavity of the MEMS chip with the sound channel outlet. The MEMS microphone can reduce the occurrence of the condition that foreign matters such as dust in the external environment fall into the MEMS microphone.

Description

MEMS microphone and electronic device
Technical Field
The invention relates to the technical field of microphones, in particular to an MEMS (micro-electromechanical systems) microphone.
Background
Micro Electro Mechanical System (Micro Electro Mechanical System) microphones (abbreviated as MEMS microphones) are commonly applied to electronic devices as acoustic-electric conversion devices. However, the conventional MEMS microphone usually has a sound inlet formed in the housing, which causes the package cavity inside the housing to be directly exposed to the external environment through the sound inlet, so that foreign objects such as dust in the external environment can easily fall into the package cavity through the sound inlet, and further contaminate or damage components (such as the MEMS chip, the ASIC chip, and circuits on the PCB board) in the package cavity, and finally causes the performance of the MEMS microphone to be reduced or even fail.
Disclosure of Invention
The invention mainly aims to provide an MEMS microphone, aiming at reducing the occurrence of the condition that foreign matters such as dust in the external environment fall into the MEMS microphone so as to improve the signal-to-noise ratio of the MEMS microphone.
In order to achieve the above object, the present invention provides an MEMS microphone, which includes a PCB, a housing and an MEMS chip; the PCB is provided with a bottom surface, a top surface and side surfaces arranged along the periphery of the bottom surface and the top surface; the PCB is provided with a sound inlet channel, the sound inlet channel is provided with a channel inlet and a channel outlet, the channel inlet is formed on the side surface, and the channel outlet is formed on the top surface; the shell covers the top surface of the PCB to form a packaging cavity with the PCB in a surrounding manner; the MEMS chip is arranged in the packaging cavity and connected with the PCB, and the MEMS chip covers the sound channel outlet so as to communicate the back cavity of the MEMS chip with the sound channel outlet.
Optionally, the MEMS chip includes a substrate and a vibrating membrane layer disposed on top of the substrate, and the substrate and the vibrating membrane layer enclose to form the back cavity; wherein the periphery of the substrate is connected with the periphery of the sound channel outlet.
Optionally, the casing is further provided with a sound inlet, and the sound inlet is communicated with the packaging cavity.
Optionally, the housing comprises a top wall plate and a side wall plate arranged along the circumference of the top wall plate; the sound inlet hole is formed in the top wall plate.
Optionally, the MEMS microphone further comprises a dust removal structure disposed within the sound entrance channel, the dust removal structure covering a cross-section of the sound entrance channel.
Optionally, the dust removing structure is a foam material, and the foam material is filled from the sound channel inlet of the sound inlet channel to the sound channel outlet thereof.
Optionally, the sound inlet channel comprises a transverse channel and a longitudinal channel; said transverse channel extending inwardly from a side thereof, an outer end of said transverse channel forming said acoustic channel inlet; the longitudinal channel penetrates through the top surface from the inner end of the transverse channel upwards, and the upper end of the longitudinal channel forms the sound channel outlet.
Optionally, the distance between the top wall of the transverse channel and the bottom wall thereof is defined as D1(ii) a The thickness of the PCB is defined as H; wherein H/3 is not more than D1≤H/2。
Optionally, a distance between a top wall of the transverse channel and a top surface of the PCB board is defined as D2The distance between the bottom wall of the transverse channel and the bottom surface of the PCB board is defined as D3(ii) a Wherein D is2＝D3。
The invention provides an electronic device which comprises an electronic device body and an MEMS microphone, wherein the MEMS microphone is installed in the electronic device body. The MEMS microphone comprises a PCB, a shell and an MEMS chip; the PCB is provided with a bottom surface, a top surface and side surfaces arranged along the periphery of the bottom surface and the top surface; the PCB is provided with a sound inlet channel, the sound inlet channel is provided with a channel inlet and a channel outlet, the channel inlet is formed on the side surface, and the channel outlet is formed on the top surface; the shell covers the top surface of the PCB to form a packaging cavity with the PCB in a surrounding manner; the MEMS chip is arranged in the packaging cavity and connected with the PCB, and the MEMS chip covers the sound channel outlet so as to communicate the back cavity of the MEMS chip with the sound channel outlet.
According to the technical scheme, the sound inlet channel is arranged on the PCB of the MEMS microphone, the sound channel inlet of the sound inlet channel is formed on the side face of the PCB, and the sound channel outlet of the sound inlet channel is formed on the top face of the PCB and is communicated with the back cavity of the MEMS chip, so that impurities such as dust in the external environment are difficult to fall into the sound channel inlet of the sound inlet channel from the side face of the MEMS microphone and difficult to pass through the bent sound inlet channel to enter the packaging cavity, the situation that foreign matters such as dust in the external environment fall into the packaging cavity is effectively reduced, parts (such as the MEMS chip, the ASIC chip and circuits on the PCB) in the packaging cavity are prevented from being polluted or damaged, the signal-to-noise ratio of the MEMS microphone is improved, and the quality of the MEMS microphone is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a schematic structural diagram of a conventional MEMS microphone;
FIG. 2 is a schematic structural diagram of an embodiment of a MEMS microphone (dual directional microphone) of the present invention;
FIG. 3 is an enlarged view taken at A in FIG. 2;
FIG. 4 is a schematic diagram of the PCB board and the sound inlet channel in FIG. 3;
FIG. 5 is a schematic structural diagram of another embodiment of a MEMS microphone (dual directional microphone) of the present invention;
fig. 6 is a schematic structural diagram of a MEMS microphone (single directional microphone) according to an embodiment of the present invention.
The reference numbers illustrate:
reference numerals Name (R) Reference numerals Name (R)
100 PCB board 10b The top surface
110 Sound inlet channel 10c Side surface
111 Transverse channel 200 Shell body
112 Longitudinal channel 210 Top wall board
101 Sound channel entrance 220 Side wall board
102 Sound channel outlet 300 MEMS chip
120 Dust-removing structure/foam material 310 Substrate
10a Bottom surface 320 Vibration film layer
400 ASIC chip
The objects, features and advantages of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.
In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
Referring to fig. 1, the conventional MEMS microphone includes a PCB 100, a case 200, and a chip assembly. Wherein, the top wall of the casing 200 is opened with a sound inlet 201, the sound inlet 201 is open to the PCB 100, so that the packaging cavity 202 between the casing 200 and the PCB 100 is directly exposed to the external environment through the sound inlet 201. Therefore, the method of directly opening the sound inlet 201 on the casing 200 has at least three disadvantages: firstly, foreign matter such as dust in the external environment directly falls into the packaging cavity 202 from the sound inlet hole 201, further polluting or damaging components (such as the MEMS chip 300, the ASIC chip 400, circuits on the PCB 100 and the like) in the packaging cavity 202, and finally causing the performance of the MEMS microphone to be reduced or even fail; secondly, the sound inlet hole 201 on the shell 200 is positioned above the MEMS chip 300, so that external light can easily irradiate the MEMS chip 300 from the sound inlet hole 201, and the MEMS chip 300 is sensitive to light and is easily damaged by direct irradiation of the light; thirdly, the sound inlet hole 201 arranged on the shell 200 destroys the structural integrity of the shell 200, so that the shell 200 is not a closed structure any more, and the sealing performance of the packaging cavity 202 formed inside the shell 200 is reduced; when a user has a demand for the MEMS microphone to have other non-linear sound channels (e.g., L-shaped sound channels), a hollow sound channel structure (e.g., L-shaped hollow cylinder) needs to be additionally arranged at the position of the sound inlet 201, and the user experience is poor.
Referring to fig. 2, in view of the above problems, the present invention provides an embodiment of a MEMS microphone, which can solve one or two or more of the above disadvantages of the conventional MEMS microphone by disposing an acoustic channel 110 on a PCB 100. The MEMS microphone of the present invention may be a single directional microphone and a dual directional microphone. In the following embodiments, the details are first described by taking a dual directional microphone as an example.
Referring to fig. 2 and 3, in an embodiment of the MEMS microphone of the present invention, the MEMS microphone is a dual directional microphone. The MEMS microphone comprises a PCB board 100, a shell 200 and an MEMS chip 300; the PCB 100 has a bottom surface 10a, a top surface 10b and a side surface 10c arranged along the circumference thereof; the PCB 100 is provided with a sound inlet channel 110, the sound inlet channel 110 has a channel inlet 101 and a channel outlet 102, the channel inlet 101 is formed on the side surface 10c, and the channel outlet 102 is formed on the top surface 10 b; the housing 200 covers the top surface 10b of the PCB board 100 to form an enclosure 202 with the PCB board 100; the MEMS chip 300 is disposed in the packaging chamber 202 and connected to the PCB board 100, and the MEMS chip 300 covers over the acoustic channel outlet 102, so that the back chamber 301 of the MEMS chip 300 is communicated with the acoustic channel outlet 102.
Specifically, the PCB board 100 has circuits integrated thereon; the housing 200 is made of a metal material for shielding external signal interference. The case 200 is covered on the PCB 100, and the lower periphery of the case 200 is connected to the PCB 100 to form a package 202 with the PCB 100, wherein the package 202 is used for packaging the MEMS chip 300 and the ASIC chip 400 of the MEMS microphone.
An acoustic inlet channel 110 is disposed within the interior of the PCB board 100, the acoustic inlet channel 110 communicating the external environment with the enclosure 202. When the MEMS microphone is in operation, sound of the external environment is transmitted from the sound channel inlet 101 and the sound channel outlet 102 of the sound inlet channel 110 into the back cavity 301 of the MEMS chip 300, and is further sensed by the diaphragm on the top of the MEMS chip 300. Since the sound channel entrance 101 of the sound inlet channel 110 is formed on the side surface 10c of the PCB 100 and the sound channel exit 102 thereof is formed on the top surface 10b of the PCB 100, that is, the sound inlet channel 110 is formed with an inflection point in the extending direction thereof, so that the sound inlet channel 110 is non-linear, the non-linear sound inlet channel 110 can achieve the effects of dust prevention, light shielding and the like, which will be described in detail later.
According to the technical scheme of the invention, the sound inlet channel 110 is arranged on the PCB 100 of the MEMS microphone, the sound channel inlet 101 of the sound inlet channel 110 is formed on the side surface 10c of the PCB 100, and the sound channel outlet 102 is formed on the top surface 10b of the PCB 100 and is communicated with the back cavity 301 of the MEMS chip 300, so that impurities such as dust in the external environment are difficult to fall into the sound channel inlet 101 of the sound inlet channel 110 from the side surface 10c of the MEMS microphone, and difficult to pass through the bent sound inlet channel 110 and enter the packaging cavity 202, and therefore, the occurrence of the situation that foreign matters such as dust in the external environment fall into the packaging cavity 202 is effectively reduced, components (such as the MEMS chip 300, the ASIC chip 400, circuits on the PCB 100 and the like) in the packaging cavity 202 are prevented from being polluted or damaged, the signal-to-noise ratio of the MEMS microphone can be improved, and the quality of the MEMS microphone is improved.
As described above, the sound inlet channel 110 is non-linear, so that light outside the MEMS microphone is difficult to pass through the sound inlet channel 110, i.e. difficult to irradiate on the MEMS chip 300 in the package 202; moreover, the sound channel outlet 102 of the sound inlet channel 110 is located on the top surface 10b of the PCB board 100, the sound channel outlet 102 is not opposite to the MEMS chip 300, and even if a small amount of light enters the package cavity 202 from the sound channel outlet 102 of the sound inlet channel 110, the light is difficult to be directly incident on the MEMS chip 300, so that the MEMS chip 300 can be prevented from being damaged by direct incidence of strong light.
In addition, as the sound inlet channel 110 is formed on the PCB 100, no pore structure is formed on the housing 200, so that the structure of the housing 200 is kept complete, and the housing 200 and the PCB 100 enclose to form the packaging cavity 202 with good sealing performance, thereby greatly improving the sealing performance of the packaging cavity 202. Therefore, electromagnetic radiation from the external environment and the like are difficult to enter the package cavity 202, and interference of the external electromagnetic radiation on the structure of the MEMS chip 300 and the like is reduced. .
Referring to fig. 2 and 3, in an embodiment, the MEMS chip 300 includes a substrate 310 and a diaphragm layer 320 disposed on top of the substrate 310, and a back cavity 301 is defined between the substrate 310 and the diaphragm layer 320; wherein the periphery of the substrate 310 is connected with the periphery of the sound channel outlet 102 by soldering, so that the back cavity 301 has better sealing performance. The sound directly enters the back cavity 301 of the MEMS chip 300 from the sound channel outlet 102 of the sound inlet channel 110, and the sound is transmitted from the bottom of the MEMS chip 300 to the diaphragm layer 320 at the top of the MEMS chip, so that the leakage or attenuation of the sound wave is reduced, and the sound wave is rapidly sensed by the diaphragm layer 320, thereby effectively improving the sensing efficiency of the MEMS chip 300.
Further, the MEMS microphone further includes an ASIC chip 400 disposed on the PCB 100 and electrically connected to the PCB 100, and the ASIC chip 400 is connected to the MEMS chip 300. Specifically, the ASIC chip 400 is electrically connected to the MEMS chip 300 through a metal wire, and the ASIC chip 400 is used for processing an electrical signal.
Referring to fig. 2 to 4, in an embodiment, the sound inlet channel 110 includes a transverse channel 111 and a longitudinal channel 112; wherein, the transverse channel 111 extends inwards from the side surface 10c of the PCB board 100, and the outer end of the transverse channel 111 forms the sound channel inlet 101; a longitudinal passage 112 extends upwardly through the top surface 10b from the inner end of the transverse passage 111, and the upper end of the longitudinal passage 112 forms the acoustic channel outlet 102.
Specifically, the transverse channel 111 and the longitudinal channel 112 of the sound entrance channel 110 are disposed in an L-shape, and the communication position between the transverse channel 111 and the longitudinal channel 112 forms an inflection point of the sound entrance channel 110. The inflection point can be a right-angle inflection point or an arc inflection point. Dust or light from the external environment is blocked by the inflection point, and is difficult to pass through the inflection point and enter the package cavity 202 of the MEMS microphone.
It is worth mentioning that the conventional MEMS microphone is provided with the sound hole 201 directly penetrating the housing 200 without forming an L-shaped sound channel. Therefore, when a user needs an L-shaped sound channel for the MEMS microphone, an L-shaped sound channel structure (L-shaped hollow cylinder) needs to be additionally arranged at the position of the sound inlet 201, and the user experience is poor. In this embodiment, since the sound inlet channel 110 of the MEMS microphone is L-shaped, the sound inlet channel 110 itself forms an L-shaped sound channel, so as to meet the requirement of the user for the MEMS microphone to have the L-shaped sound channel, and the user does not need to additionally configure an L-shaped sound channel structure for the MEMS microphone, so that the user can design more flexibly, and the use experience of the MEMS microphone is greatly improved.
Of course, the shape of the sound entrance channel 110 is not limited to the aforementioned L-shape. In other embodiments, the sound input channel 110 may also be a channel arranged in a Y-shape (i.e. the sound input channel 110 has one channel inlet 101 and two channel outlets 102); alternatively, the sound inlet channel 110 is arcuate.
Referring to fig. 2 to 4, in an embodiment, considering that the thickness of the PCB 100 is much smaller than that of the PCBThe width or length of the transverse channel 111, and the distance from the top wall of the transverse channel 111 to the top surface 10b of the PCB board 100, easily affect the strength of the PCB board 100 in the thickness direction. For ease of explanation, the distance D between the top wall of the transverse channel 111 and its bottom wall is defined herein as1(ii) a The thickness of the PCB 100 is defined as H; wherein the distance between the top wall of the transverse channel 111 and the bottom wall thereof (i.e. D)1) Corresponding to the radial height of the transverse channel 111.
It was found that if said D is present1Smaller than H/3, the radial height of the lateral passage 111 is smaller, so that the cross section of the lateral passage 111 is also smaller, and thus the propagation resistance of sound is larger, and sound is not easily received. And if said D is1If the height is greater than H/2, the radial height of the transverse channel 111 is greater, which makes the PCB board 100 more hollow at the position corresponding to the transverse channel 111, and it is difficult to ensure the strength of the PCB board 100 at the position.
Based on this, in the present embodiment, the D may be selected1Designed as H/3 is not more than D1Less than or equal to H/2. Said D1Within this range, it is possible to ensure that the cross passage 111 of the sound entrance channel 110 has a large cross section, reducing the sound propagation resistance to increase the sound reception amount; in addition, the hollow degree of the position of the PCB 100 corresponding to the transverse channel 111 is not too large, so that the PCB 100 has better strength at the position and is not easy to break.
Further, the distance between the top wall of the transverse channel 111 and the top surface 10b of the PCB board 100 is defined as D2The distance D between the bottom wall of the transverse channel 111 and the bottom surface 10a of the PCB board 100 is defined as3(ii) a Wherein D is2＝D3Therefore, the thickness of the part of the PCB 100 positioned on the upper side of the transverse channel 111 is equivalent to the thickness of the part of the PCB 100 positioned on the lower side of the transverse channel 111, the strength of the parts of the PCB 100 positioned on the upper and lower sides of the transverse channel 111 is basically equivalent, and the situation that the parts are broken due to weak strength on one side is not easy to occur.
Referring to fig. 3 and fig. 5, based on any of the above embodiments, it is further considered that, during the operation of the MEMS microphone, the vibration of the diaphragm on the MEMS chip 300 changes the difference between the internal pressure and the external pressure, so that airflow is generated in the sound inlet channel 110, and the airflow may carry part of dust and other foreign matters into the package cavity 202, so as to contaminate the structures of the MEMS chip 300 or the ASIC chip 400 in the package cavity 202.
In view of this, to reduce this occurrence, optionally, the MEMS microphone further comprises a dust removing structure 120, the dust removing structure 120 being disposed within the sound inlet channel 110, the dust removing structure 120 covering a cross section of the sound inlet channel 110. The dust removing structure 120 is used for filtering foreign matters such as dust entering the sound inlet channel 110, so as to prevent the foreign matters from entering the packaging cavity 202 from the sound inlet channel 110, and further prevent structures such as the MEMS chip 300 or the ASIC chip 400 from being polluted.
Various structural designs are possible for the particular type of dust extraction structure 120. For example, the dust removing structure 120 may be a structure having a function of filtering foreign substances such as dust, such as a foam material 120, a filter net, and a fiber woven filter material. Specifically, in the present embodiment, the dust removing structure 120 is a foam material 120, and the foam material 120 is filled in the sound inlet channel 110.
The foaming material 120 can be gasified to generate bubbles in the narrow sound inlet channel 110 to form a porous foaming structure, which not only reduces the difficulty of arranging the dust removing structure 120 in the narrow sound inlet channel 110, but also facilitates the sound transmission and is not easy to block the sound from transmitting into the packaging cavity 202. The foam material 120 can be specifically selected from a soft foam material 120 or a structural foam material; the soft foam material 120 may be prepared by physically foaming or cross-linking foaming by adding a catalyst, a foam stabilizer, a foaming agent, and other auxiliary materials to raw materials such as plastics (PE, EVA, and the like) and rubbers (SBR, CR, and the like); structural foam is based on plastics (PVC, PET, etc.) etc. modified by a interpenetrating aromatic amide polymeric network 120.
Referring to fig. 3 and 5, further, the foaming material 120 is filled from the channel inlet 101 of the sound inlet channel 110 to the channel outlet 102 thereof. That is, the transverse channel 111 and the longitudinal channel 112 of the sound inlet channel 110 are filled with the foaming material 120, so that the filtering and dust removing area is increased, and the dust removing efficiency is greatly improved. In the filling process, the foaming material 120 may be filled into the sound entrance channel 110 at a time from one end of the sound entrance channel 110 (e.g., the channel entrance 101 or the channel exit 102) until the foaming material 120 emerges from the other end of the sound entrance channel 110 and the filling is stopped; alternatively, the foaming material 120 may be quantitatively filled from both ends of the sound inlet channel 110 (i.e., the channel inlet 101 and the channel outlet 102) at the same time, that is, the channel inlet 101 and the channel outlet 102 are simultaneously filled into the transverse channel 111 and the longitudinal channel 112, respectively, so that the filling effect is better and the filling efficiency is higher.
Referring to fig. 2 or fig. 5, in the MEMS microphone in any of the above embodiments, the MEMS microphone is a dual directional microphone, that is, the dual directional microphone is only provided with the sound inlet channel 110 on the PCB 100, and the housing 200 is not formed with the sound inlet hole 201. The dual directional microphone can solve one or two or more defects of the conventional MEMS microphone.
Referring to fig. 6, for a single directional microphone, on the basis of any of the foregoing embodiments, without considering the influence of light, electromagnetic radiation, or foreign matter, the housing 200 of the MEMS microphone is further provided with a sound inlet 201, and the sound inlet 201 is communicated with the packaging cavity 202, so that the MEMS microphone becomes a single directional microphone, and the single directional microphone can enter sound through the sound inlet 201 and the sound inlet channel 110, so that a larger sound receiving range can be obtained, and the single directional microphone can obtain higher performance. Because the single-direction microphone is also provided with the sound inlet channel 110, and the sound inlet channel 110 is nonlinear, the single-direction microphone can at least solve the problem that a user has nonlinear sound channel requirements on the MEMS microphone, so that the user does not need to additionally configure a sound channel structure for the MEMS microphone, the user can design more flexibly, and the use experience of the MEMS microphone is greatly improved.
Further, the housing 200 includes a top wall panel 210 and a side wall panel 220 disposed along a circumference of the top wall panel 210; the lower peripheral edge of the sidewall plate 220 is hermetically connected to the top surface 10b of the PCB board 100, for example, by soldering with solder paste, so as to form a package cavity 202 with good sealing property between the housing 200 and the PCB board 100. The sound inlet hole 201 is provided in the top wall panel 210.
The invention also provides an electronic device, which comprises an electronic device body and the MEMS microphone; wherein the MEMS microphone is mounted within the electronic device body. The specific structure of the MEMS microphone refers to the above embodiments, and since the electronic device adopts all the technical solutions of all the above embodiments, all the beneficial effects brought by the technical solutions of the above embodiments are also achieved, and are not described in detail herein. The electronic device can be a sensor, a mobile phone, a tablet, a notebook computer and other electronic equipment.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. A MEMS microphone, comprising:
a PCB having a bottom surface, a top surface, and side surfaces disposed along a circumference thereof; the PCB is provided with a sound inlet channel, the sound inlet channel is provided with a channel inlet and a channel outlet, the channel inlet is formed on the side surface, and the channel outlet is formed on the top surface;
the shell covers the top surface of the PCB to form an encapsulation cavity with the PCB in an enclosing manner; and
the MEMS chip is arranged in the packaging cavity and connected with the PCB, and the MEMS chip covers the upper part of the sound channel outlet so as to enable the back cavity of the MEMS chip to be communicated with the sound channel outlet.
2. The MEMS microphone of claim 1, wherein the MEMS chip comprises a substrate and a diaphragm layer disposed on top of the substrate, the substrate and the diaphragm layer enclosing to form the back cavity; wherein the periphery of the substrate is connected with the periphery of the sound channel outlet.
3. The MEMS microphone of claim 1, wherein the housing further defines a sound inlet, and the sound inlet is in communication with the package cavity.
4. The MEMS microphone of claim 3, wherein the housing comprises a top wall plate and a side wall plate disposed along a circumference of the top wall plate; the sound inlet hole is formed in the top wall plate.
5. The MEMS microphone of any one of claims 1 to 4, further comprising a dust extraction structure disposed within the sound entry channel, the dust extraction structure covering a cross-section of the sound entry channel.
6. The MEMS microphone of claim 5, wherein the dust-extraction structure is a foam material that fills from a channel inlet of the sound-entry channel to a channel outlet thereof.
7. The MEMS microphone of any one of claims 1 to 4, wherein the sound inlet channel comprises:
a transverse channel extending inwardly from a side thereof, an outer end of the transverse channel forming the channel inlet; and
the longitudinal channel penetrates through the top surface from the inner end of the transverse channel upwards, and the upper end of the longitudinal channel forms the sound channel outlet.
8. The MEMS microphone of claim 7, wherein a distance between a top wall of the transverse channel and a bottom wall thereof is defined as D1(ii) a The thickness of the PCB is defined as H; wherein H/3 is not more than D1≤H/2。
9. The MEMS microphone of claim 7, wherein a top wall of the transverse channel is to the top wallThe distance between the top surfaces of the PCBs is defined as D2The distance between the bottom wall of the transverse channel and the bottom surface of the PCB board is defined as D3(ii) a Wherein D is2＝D3。
10. An electronic device, comprising:
an electronic device body; and
the MEMS microphone of any one of claims 1-9, mounted within the electronic device body.
CN202110203364.XA 2021-02-23 2021-02-23 MEMS microphone and electronic device Pending CN112995868A (en)

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CN202110203364.XA CN112995868A (en) 2021-02-23 2021-02-23 MEMS microphone and electronic device

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Application Number Priority Date Filing Date Title
CN202110203364.XA CN112995868A (en) 2021-02-23 2021-02-23 MEMS microphone and electronic device

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100128914A1 (en) * 2008-11-26 2010-05-27 Analog Devices, Inc. Side-ported MEMS microphone assembly
CN202679629U (en) * 2012-06-26 2013-01-16 歌尔声学股份有限公司 MEMS (Micro-electromechanical System) microphone
CN103957498A (en) * 2014-05-21 2014-07-30 苏州敏芯微电子技术有限公司 Side-sound-input silicon microphone packaging structure
CN204707164U (en) * 2015-05-25 2015-10-14 全椒县必达机械有限公司 Mobile microphone sound cavity sealing structure
CN207283807U (en) * 2017-09-05 2018-04-27 深圳市艾辰电子有限公司 A kind of single direction silicon microphone

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100128914A1 (en) * 2008-11-26 2010-05-27 Analog Devices, Inc. Side-ported MEMS microphone assembly
CN202679629U (en) * 2012-06-26 2013-01-16 歌尔声学股份有限公司 MEMS (Micro-electromechanical System) microphone
CN103957498A (en) * 2014-05-21 2014-07-30 苏州敏芯微电子技术有限公司 Side-sound-input silicon microphone packaging structure
CN204707164U (en) * 2015-05-25 2015-10-14 全椒县必达机械有限公司 Mobile microphone sound cavity sealing structure
CN207283807U (en) * 2017-09-05 2018-04-27 深圳市艾辰电子有限公司 A kind of single direction silicon microphone

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Application publication date: 20210618