CN111083622A - Novel prevent radio frequency interference's micro-electromechanical system microphone - Google Patents
Novel prevent radio frequency interference's micro-electromechanical system microphone Download PDFInfo
- Publication number
- CN111083622A CN111083622A CN201911378239.1A CN201911378239A CN111083622A CN 111083622 A CN111083622 A CN 111083622A CN 201911378239 A CN201911378239 A CN 201911378239A CN 111083622 A CN111083622 A CN 111083622A
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- China
- Prior art keywords
- circuit board
- printed circuit
- acoustic
- radio frequency
- acoustic sensor
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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
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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
- 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
Abstract
The embodiment of the invention discloses a novel radio frequency interference prevention micro-electromechanical system microphone, which comprises a printed circuit board, wherein a packaging shell is buckled at the top end of the printed circuit board, and the printed circuit board is provided with: an acoustic via; an acoustic sensor; the ASIC chip is connected with the acoustic sensor through a gold wire; at least one capacitor embedded on the printed circuit board; the surface-mounted resistor is connected with the capacitor in parallel to form the RC low-pass filter circuit, the film resistor of the traditional microphone is replaced by the surface-mounted resistor, the resistance value is larger than that of the traditional film resistor, the heating value is reduced, the service life is longer, the cost is reduced, the reliability of the resistor is improved, the acoustic through hole is arranged on the printed circuit board, the sound transmission path is shorter, the vibrating diaphragm rear cavity formed by the space between the vibrating diaphragm and the acoustic cavity of the acoustic sensor is increased, the vibrating difficulty of the vibrating diaphragm is small, the sensitivity and the signal-to-noise ratio of the acoustic sensor are improved, and the tone quality and the performance of the microphone are improved.
Description
Technical Field
The invention relates to the field of microphones, in particular to a novel radio frequency interference prevention micro-electro-mechanical system microphone.
Background
Another important trend in MEMS microphones is resistance to Radio Frequency (RF) interference. When handsets and wireless devices transmit data, the antenna can pick up noise in a number of ways. For example, diode junctions in an Application Specific Integrated Circuit (ASIC) rectify a radio frequency signal, the envelope of which produces noise in the output sound of the microphone.
The radio frequency interference is interference caused by electromagnetic waves, for example, two electromagnetic waves with frequencies which are not much different from each other can be simultaneously received by a receiver to cause interference, harmonic interference exists at a place close to a transmitting station to interfere other receiving equipment, and the electromagnetic waves with the same frequency transmitted can interfere with a radio station of an enemy.
The traditional method for preventing radio frequency interference of the microphone is to embed a film capacitor or a film resistor in a PCB, so that the traditional microphone has poor heat dissipation property and high cost.
Disclosure of Invention
The invention aims to provide a novel micro-electromechanical system microphone capable of preventing radio frequency interference, and solves the technical problems.
The technical problem solved by the invention can be realized by adopting the following technical scheme:
a novel anti-RF interference micro-electro-mechanical system microphone comprises
The printed circuit board is characterized in that a packaging shell is buckled at the top end of the printed circuit board, an acoustic cavity is formed by the printed circuit board and the internal space of the packaging shell, and the printed circuit board is provided with:
an acoustic via;
an acoustic sensor;
the ASIC chip is connected with the acoustic sensor through a gold wire;
at least one capacitor embedded on the printed circuit board;
and the surface-mounted resistor is connected with the capacitor in parallel to form an RC low-pass filter circuit.
Preferably, the package casing is a metal package casing, and the printed circuit board is a ceramic PCB board.
Preferably, the area of the top surface of the printed circuit board is larger than the area of the bottom surface of the inner cavity of the packaging shell, and the bottom end of the packaging shell is connected with the top surface of the printed circuit board in a sealing manner.
Preferably, the printed circuit board is embedded in the bottom end of the interior of the package casing, and the side wall of the printed circuit board is hermetically connected with the inner wall of the package casing.
Preferably, the acoustic sensor is electrically connected to the printed circuit board, and the ASIC chip is electrically connected to the printed circuit board.
Preferably, a sound-permeable waterproof membrane is arranged on the acoustic through hole.
Preferably, a plurality of pads are arranged on the bottom surface of the printed circuit board.
Preferably, the acoustic sensor is mounted on the first side of the inner wall of the package housing, the acoustic through hole is also formed in the first side of the inner wall of the package housing, and the acoustic sensor is electrically connected to the printed circuit board through a gold wire.
Has the advantages that: the invention replaces the film resistor of the traditional microphone with the surface-mounted resistor, has larger resistance value than the traditional film resistor, reduces the heat productivity, has longer service life, reduces the cost and improves the reliability of the resistor, the acoustic through hole is arranged on the printed circuit board, the sound transmission path is shorter, and the vibrating diaphragm rear cavity formed by the space between the vibrating diaphragm and the acoustic cavity of the acoustic sensor is enlarged, thereby improving the sensitivity and the signal-to-noise ratio of the acoustic sensor and improving the tone quality and the performance of the microphone.
Drawings
Fig. 1 is a schematic cross-sectional structural diagram of a mems microphone according to a first embodiment of the invention;
fig. 2 is a schematic view of another package structure of a mems microphone according to a first embodiment of the invention;
fig. 3 is a schematic cross-sectional structure diagram of a mems microphone according to a second embodiment of the invention.
In the figure: 1-a package housing; 2-a printed circuit board; 3-an acoustic cavity; 4-an acoustic sensor; 5-an ASIC chip; 6-capacitance; 7-surface mounting a resistor; 8-a pad; 9-acoustic vias; 10-a diaphragm; 11-sound-through waterproof membrane.
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 the embodiments and features of the embodiments may be combined with each other without conflict.
The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.
The first embodiment is as follows:
as shown in FIG. 1, the present invention provides a novel RF interference resistant MEMS microphone, which comprises
A printed circuit board 2, a packaging shell 1 is buckled on the printed circuit board 2 and is connected with the bottom of the packaging shell 1, the printed circuit board 2 and the internal space of the packaging shell 1 form an acoustic cavity 3, and the printed circuit board 1 is provided with:
the acoustic sensor 4 is used for converting an externally input sound signal into an electric signal and outputting the electric signal to the ASIC chip;
an acoustic through hole 9 corresponding to the position of the acoustic sensor 4;
an ASIC chip 5, an ASIC (application Specific Integrated circuit) ASIC, connected to the acoustic sensor 4 by a gold wire, for converting the signal transmitted by the acoustic sensor 4 into a suitable signal for output;
at least one capacitor 6, the capacitor 6 is embedded on the printed circuit board 2; the embedded capacitor is also called as an embedded capacitor and is a capacitor material which can be embedded into a printed circuit board (a flexible board or a rigid board), and the material has high capacitance density, so that the material plays a role in decoupling and filtering a power supply system, thereby reducing the separation capacitor and enabling the packaging structure to be smaller and more exquisite.
At least one surface-mounted resistor 7 is connected with the capacitor 6 in parallel to form an RC low-pass filter circuit. The RC circuit has a filtering function and can also play a certain role in resisting radio frequency interference. The low pass filter circuit is a circuit that passes a low frequency signal but does not pass a middle or high frequency signal, and functions to filter out middle and high frequency components in an audio signal and enhance a low frequency component to drive a low frequency unit of a speaker. And the radio frequency interference signal is set as a signal which can not be passed by the RC low-pass filter circuit, so that the radio frequency interference signal can be effectively filtered.
The invention has the advantages that:
the invention replaces the film resistor of the traditional microphone with the surface-mounted resistor, has larger resistance value than the traditional film resistor, reduces the heat productivity, has longer service life, reduces the cost and improves the reliability of the resistor, the acoustic through hole is arranged on the printed circuit board, the sound transmission path is shorter, the back cavity of the vibrating diaphragm formed by the space between the vibrating diaphragm and the acoustic cavity of the acoustic sensor is increased, the vibration resistance of the vibrating diaphragm is small, the sensitivity and the signal-to-noise ratio of the acoustic sensor are improved, and the tone quality and the performance of the microphone are improved.
As a preferred embodiment of the present invention, the package case 1 is a metal package case, and the metal package case enables the microphone to have certain anti-electromagnetic interference and anti-radio frequency interference capabilities, so as to improve the sound quality of the microphone. The printed circuit board 2 is a ceramic PCB which is beneficial to heat dissipation, so that the service life of electronic elements in the microphone is longer.
As a preferred embodiment of the present invention, the acoustic through hole 9 communicates with the acoustic chamber 3 so that sound is transmitted.
As a preferred embodiment of the present invention, the acoustic sensor is electrically connected to the printed circuit board, and the ASIC chip 5 is electrically connected to the printed circuit board 2. The acoustic sensor and the ASIC chip can be powered on the printed circuit board, and signals are adjusted by other circuit elements such as resistors, capacitors and the like on the printed circuit board and then transmitted to corresponding sound equipment.
As a preferred embodiment of the invention, the bottom end of the package 1 is sealingly connected to the top side of the printed circuit board 2. The gap between the packaging shell 1 and the printed circuit board 2 is filled with heat-conducting glue, so that the sealing performance is ensured. And the heat on the printed circuit board 2 is conveniently and timely conducted to the metal packaging shell 1, so that the heat dissipation is convenient.
As shown in fig. 2, as another packaging method of the microphone of the present invention, the printed circuit board 2 is embedded in the bottom end of the interior of the package case 1, and the side surface of the printed circuit board 2 is hermetically connected to the inner wall of the package case 1. The benefits of this are: the printed circuit board 2 is arranged inside the packaging shell 1, and the packaging shell 1 can effectively protect the side part of the printed circuit board 2 from pressure, so that the possibility of damage to the printed circuit board 2 is reduced. And because the printed circuit board 2 does not occupy the external volume, the thickness of the microphone can be effectively reduced.
As a preferred embodiment of the invention, the sound-through waterproof membrane 11 is arranged on the acoustic through hole 9, the acoustic through hole 9 is the sound hole closest to the acoustic sensor 4, and the sound-through waterproof membrane 11 is arranged to effectively prevent the electronic devices in the microphone from being damaged by water entering and not influencing the transmission of sound.
In a preferred embodiment of the present invention, the bottom surface of the printed circuit board 2 is provided with a plurality of pads 8 for facilitating packaging inside the electronic device, and the pads connect the external circuit of the microphone with the circuit of the printed circuit board 2, so that the microphone is electrically supported.
In a preferred embodiment of the present invention, it is added that the acoustic cavity space between the sound inlet hole and the acoustic sensor diaphragm 10 is called a front chamber, and the other side of the diaphragm 10 is called a back chamber.
Example two:
as shown in FIG. 3, a novel anti-RF interference MEMS microphone comprises
The acoustic sensor is characterized by comprising a packaging shell 1, wherein an acoustic sensor 4 is arranged on a first side of the inner wall of the packaging shell 1; the acoustic sensor 4 is electrically connected with the printed circuit board 2 through a gold wire, an acoustic through hole 9 is formed in the first side of the packaging shell 1, and the acoustic through hole 9 corresponds to the acoustic sensor in position.
A printed circuit board 2, with packaging shell 1 bottom be connected, printed circuit board 2 and packaging shell 1 inner space constitute an acoustics cavity 3, set up on the printed circuit board 1:
an ASIC chip 5 connected to the acoustic sensor 4 by gold wires;
at least one capacitor 6 embedded on the printed circuit board 2;
at least one surface mounted resistor 7 is connected with the capacitor 6 to form an RC circuit.
The advantages of mounting the acoustic sensor on the inner wall of the package are as follows:
(1) the acoustic sensor 4 is fixed on the inner side wall of the packaging shell through the insulating heat-conducting packaging adhesive, so that the mounting area of the printed circuit board 2 can be saved, the printed circuit board 2 is more simply mounted or more other related electronic devices are mounted, and the area requirement of the printed circuit board 2 is reduced;
(2) the heat productivity of the acoustic sensor 4 can be transmitted away through the heat conducting glue and the metal packaging shell, so that heat dissipation ways are increased, the heat productivity of the printed circuit board 2 is reduced, and the service life of the printed circuit board 2 is prolonged;
(3) the back cavity of the diaphragm of the acoustic sensor is still larger than the front cavity, and the sensitivity and the signal-to-noise ratio of the acoustic sensor are high.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Claims (8)
1. A novel radio frequency interference prevention micro-electro-mechanical system microphone is characterized by comprising
The printed circuit board is characterized in that a packaging shell is buckled at the top end of the printed circuit board, an acoustic cavity is formed by the printed circuit board and the internal space of the packaging shell, and the printed circuit board is provided with:
an acoustic via;
an acoustic sensor;
the ASIC chip is connected with the acoustic sensor through a gold wire;
at least one capacitor embedded on the printed circuit board;
and the surface-mounted resistor is connected with the capacitor in parallel to form an RC low-pass filter circuit.
2. The novel radio frequency interference resistant mems microphone as claimed in claim 1, wherein the package is a metal package and the PCB is a ceramic PCB.
3. The novel radio frequency interference preventing micro-electromechanical system microphone as claimed in claim 1, wherein the area of the top surface of the printed circuit board is larger than the area of the bottom surface of the inner cavity of the package casing, and the bottom end of the package casing is hermetically connected with the top surface of the printed circuit board.
4. The novel radio frequency interference resistant mems microphone as claimed in claim 1, wherein the pcb is embedded in the bottom of the package, and the sidewall of the pcb is hermetically connected to the inner wall of the package.
5. The novel radio frequency interference resistant mems microphone of claim 1, wherein the acoustic sensor is electrically connected to the pcb, and the ASIC chip is electrically connected to the pcb.
6. The novel radio frequency interference preventing micro electro mechanical system microphone as claimed in claim 1, wherein the acoustic through hole is provided with a sound-through waterproof membrane.
7. The novel radio frequency interference resistant mems microphone as defined by claim 1, wherein the bottom surface of the pcb has a plurality of pads.
8. The novel radio frequency interference preventing micro electro mechanical system microphone as claimed in claim 1, wherein the acoustic sensor is mounted on the first side of the inner wall of the package, the acoustic through hole is also formed on the first side of the inner wall of the package, and the acoustic sensor is electrically connected to the printed circuit board through a gold wire.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911378239.1A CN111083622A (en) | 2019-12-27 | 2019-12-27 | Novel prevent radio frequency interference's micro-electromechanical system microphone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911378239.1A CN111083622A (en) | 2019-12-27 | 2019-12-27 | Novel prevent radio frequency interference's micro-electromechanical system microphone |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111083622A true CN111083622A (en) | 2020-04-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911378239.1A Pending CN111083622A (en) | 2019-12-27 | 2019-12-27 | Novel prevent radio frequency interference's micro-electromechanical system microphone |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022000853A1 (en) * | 2020-06-30 | 2022-01-06 | 瑞声声学科技(深圳)有限公司 | Vibration sensor |
| WO2022088496A1 (en) * | 2020-10-29 | 2022-05-05 | 瑞声声学科技(深圳)有限公司 | Integrated packaged module manufacturing method, integrated packaged module, and electronic device |
-
2019
- 2019-12-27 CN CN201911378239.1A patent/CN111083622A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022000853A1 (en) * | 2020-06-30 | 2022-01-06 | 瑞声声学科技(深圳)有限公司 | Vibration sensor |
| WO2022088496A1 (en) * | 2020-10-29 | 2022-05-05 | 瑞声声学科技(深圳)有限公司 | Integrated packaged module manufacturing method, integrated packaged module, and electronic device |
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