CN203933949U - Unidirectivity MEMS microphone - Google Patents
Unidirectivity MEMS microphone Download PDFInfo
- Publication number
- CN203933949U CN203933949U CN201420318349.5U CN201420318349U CN203933949U CN 203933949 U CN203933949 U CN 203933949U CN 201420318349 U CN201420318349 U CN 201420318349U CN 203933949 U CN203933949 U CN 203933949U
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- damping
- conversion system
- sound
- mems microphone
- microphone
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- 239000002184 metal Substances 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 230000003321 amplification Effects 0.000 claims description 3
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- 239000010409 thin film Substances 0.000 description 1
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- Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
Abstract
The utility model discloses a kind of unidirectivity MEMS microphone, this microphone is made up of acoustic-electric converting system, damping structure, amplifying circuit (ASIC) three parts, acoustic-electric converting system is made up of substrate, MEMS, damping sheet, shell, damping system is made up of substrate, damping sheet, and amplifying circuit is made up of ASIC, gold thread and other electronic components.The utility model can effectively be realized the unidirectivity of MEMS microphone, and can effectively reduce production costs, and manufacture craft is simple, is easy to produce assembling.
Description
Technical Field
The utility model relates to an electric and acoustic image technical field, concretely relates to unidirectional MEMS microphone.
Background
The MEMS microphone on the market at present is an omnidirectional MEMS microphone, the principle of the MEMS microphone is the same as that of a traditional electret microphone, the working principle of the MEMS microphone is that after sound waves are transmitted into the microphone, a vibration plate vibrates along with the sound waves, so that the distance between the vibration plate and a polar plate is changed, voltages at two ends of the vibration plate are changed along with the sound waves, sound-electricity conversion is completed, and signals after conversion are weak and can be used by other circuits after being amplified by a follow-up circuit.
In order to meet the requirement of suppressing environmental noise, many customers adopt an array mode to realize the environmental noise suppression. In order to realize a unidirectional electret microphone with strong directivity, some manufacturers have developed a differential electret condenser microphone, also called unidirectional electret microphone, through extensive research and repeated experiments.
The differential pressure electret condenser microphone makes the sound pressure acted on the two sides of the vibrating membrane different through the rear cavity damping structure of the electret condenser microphone, and the directivity can be formed when the pressure difference of the two sides of the vibrating membrane or the power of the pressure difference is in direct proportion. Along with the difference of the incident directions of the sound waves, the sound pressure difference acting on the two surfaces of the vibrating membrane is changed, so that different sound pickup effects are presented along with different incident angles of the sound waves. The test is performed by angular rotation with the sound inlet hole center parallel to the sound inlet hole plane as the axis, assuming the direction perpendicular to the sound inlet hole plane of the microphone is 0 degrees. Theoretically, sound pickup is strongest in the 0 degree direction, and weakest in the 180 degree direction.
The differential pressure type electret condenser microphone realized at present mainly has two main structures by increasing the sound damping material at the rear cavity part of the microphone: one is to place the damping material directly under the PCB; another is to place a damping material in the middle of the structure. The above two structures realize the unidirectional property and control the consistency thereof through the matching of PCB air holes and damping materials, common damping materials use tone tuning paper or silk cloth and the like, but the consistency of the damping materials is difficult to control, and the consistency of the unidirectional effect of the product is directly influenced.
The control of the unidirectional performance is mainly related to the air permeability of the damping material and is greatly influenced by the air permeability, so that the requirement on the fluctuation range of the air permeability parameter of the damping material becomes narrow. The damping material used in the current market, whether the material is made in China or imported, is difficult to meet the requirement, and the requirement on compactness is higher because the damping material needs to be tested piece by piece before use to ensure the consistency of the air permeability of the damping material, and in addition, the damping material is easy to deform in the processing and assembling process to cause the change of the air permeability, thereby greatly increasing the product cost and the fraction defective.
However, for the MEMS microphone, the current market only has the omni-directional MEMS microphone, and if the environmental noise is to be resisted, the MEMS microphone is realized only by an array method, which may cause problems such as increased product cost, increased difficulty in product design, influence on product miniaturization, and inability of SMT soldering.
SUMMERY OF THE UTILITY MODEL
To foretell defect, the utility model discloses based on differential electret condenser microphone structure, improve on MEMS microphone, but for realizing anti environmental noise, miniaturized and SMT welding provides a unidirectional MEMS microphone.
In order to solve the technical problem, the technical scheme of the utility model as follows:
the utility model discloses mainly constitute by acoustoelectric conversion system, damping structure, amplifier circuit (ASIC) triplex. The MEMS sound-electricity conversion system and the amplifying circuit are a conventional MEMS microphone system structure, which receives a sound signal and amplifies and converts it into a voltage signal that can be directly applied by other circuits. The damping structure is arranged in the MEMS microphone and controls the sound pressure of the rear cavity of the vibrating membrane. The concrete composition structure comprises:
the acoustic-electric conversion system consists of a substrate, an MEMS, a damping plate and a shell;
the damping system consists of a base plate and a damping plate;
the amplifying circuit is composed of an ASIC, gold wires and other electronic components.
The base plate and the damping plate in the damping system and the base plate and the damping plate in the sound-electricity conversion system are of the same structure.
The damping system is located below the product sound-electricity conversion system structure and is tightly combined with the sound-electricity conversion system, the amplifying circuit is located on the right side of the sound-electricity conversion system and is connected with the sound-electricity conversion system through a gold wire to form a circuit, and the whole structure of the final product is packaged and molded through a shell in the sound-electricity conversion system.
The damping structure is formed by welding the convex metal layer on the substrate and the damping plate.
The amplification circuit is integrated on a small ASIC chip.
Compared with the prior best technology, the utility model has the advantages that:
(1) the utility model realizes the unidirectional property of the MEMS microphone, and can effectively reduce the cost of the client and the design difficulty;
(2) the middle base plate and the damping plate of the utility model are easy to weld, and the manufacturing consistency is easy to control, so that the directional effect can be well ensured, and meanwhile, the middle base plate and the damping plate are not easy to be influenced by subsequent production and assembly to cause defects;
(3) the utility model discloses a material easily produces the assembly, and can realize in less size product, and its structure is realized adding the change slightly on conventional MEMS microphone structure, so simple to product design.
Drawings
The present invention will be further described with reference to the accompanying drawings and examples.
Fig. 1 is a schematic structural diagram of the present invention;
fig. 2 is a sound signal flow diagram of the present invention.
Detailed Description
The unidirectional MEMS microphone of the present invention mainly comprises a MEMS acousto-electric conversion system, a damping structure, and an amplification circuit (ASIC). Wherein,
the acoustic-electric conversion system consists of a substrate 1, an MEMS2, a damping plate 8 and a shell 7;
the damping system consists of a base plate 1 and a damping plate 8;
the amplifying circuit is composed of ASIC3, gold wire 4, and other electronic components (such as capacitor 5, resistor 6, etc.).
The base plate 1 and the damping plate 8 in the damping system and the base plate 1 and the damping plate 8 in the sound-electricity conversion system are of the same structure.
According to the figure 1, the damping system is located below the product sound-electricity conversion system structure and is tightly combined with the sound-electricity conversion system, the amplifying circuit is located on the right side of the sound-electricity conversion system and is connected with the sound-electricity conversion system through a gold wire 4 to form a circuit, and the whole structure of the final product is packaged and molded through a shell 7 in the sound-electricity conversion system.
An acoustic-electric conversion system: the micro-Electro-mechanical system (MEMS) is mainly manufactured by a micro-Electro-mechanical system (MEMS) technology, and a electret plate and a vibrating membrane are integrated on a silicon material through a series of existing technologies and materials such as photoetching, corrosion, thin films and the like in the technology to form an acoustoelectric conversion system which can be used by a microphone. The micro electro mechanical system has the advantages of small volume, light weight, low power consumption, good durability, low price, stable performance and the like, thereby providing a good quality foundation for products. The structure of the electret capacitor is the same as the working principle of the electret capacitor, the distance between the electret plate and the vibrating membrane is changed under the action of a sound signal by the vibrating membrane, and the voltage at two ends of the capacitor is changed along with the change of the distance between the electret plate and the vibrating membrane, so that the sound-electric signal conversion is realized.
An amplifying circuit: an ASIC (application Specific Integrated circuit) chip is mainly used, and the ASIC is specially designed for a microphone and comprises an electric signal amplifying system and a charge output system. The charge output system provides a stable and continuous voltage for an electret plate in the sound-electricity conversion system so as to ensure the stability of the sound-electricity conversion system, and the output power supply of the charge output system is not changed by the fluctuation of working voltage in a certain range; the electric signal amplifying system amplifies the weak electric signal output by the sound-electricity conversion system for the user to use.
A damping system: as shown in fig. 2, in the sound signal flow diagram, part of the sound emitted from the sound source 10 enters the microphone from the front sound hole 901, and part of the sound entering from the substrate back sound hole 902 enters the fine air gap between the substrate and the damping plate, and then flows out through the through holes in the damping plate, and acts on the diaphragm. The height of the metal boss on the substrate is controlled, so that the size of the sound signal can be adjusted, and air can be used as a damping medium to realize the damping effect on the sound signal.
The invention does not need to adopt damping materials, but forms a fine air gap through a metal structure, and uses air as a damping medium to control the sound pressure of the rear cavity of the microphone.
The fine air gap formed by the metal structure can well control the damping air permeability, thereby ensuring the size consistency of the sound pressure of the rear cavity of the microphone. The defect that the damping material is difficult to control can be effectively avoided. The simple structure and stability are easy to realize and assemble, so that the manufacturing cost and quality of the product are well guaranteed. Therefore, the cost and the design difficulty of a client product are greatly reduced, and the product miniaturization design and SMT welding are facilitated.
The above description is only the preferred embodiment of the invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.
Claims (4)
1. Unidirectional MEMS microphone, characterized in that it is mainly composed of three parts:
an acoustic-electric conversion system: the sound signal is converted into an electric signal and consists of a substrate, an MEMS, a damping plate and a shell;
damping structure: the base plate and the damping plate have the same structure as the base plate and the damping plate in the sound-electricity conversion system;
an amplifying circuit: the converted electrical signal is amplified for use by other circuits, consisting of ASICs, gold wires and other electronic components.
2. The unidirectional MEMS microphone according to claim 1, wherein the damping structure is located under the product acousto-electric conversion system structure and tightly combined with the acousto-electric conversion system, the amplifying circuit is located on the right side of the acousto-electric conversion system and connected with the acousto-electric conversion system through gold wires to form a circuit, and finally the whole structure is encapsulated and molded through a housing in the acousto-electric conversion system.
3. The unidirectional MEMS microphone of claim 1, further characterized in that the damping structure is formed by soldering a metal layer protruding on the substrate and the damping plate.
4. The unidirectional MEMS microphone of claim 1 further characterized by the amplification circuit being integrated on a small ASIC chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420318349.5U CN203933949U (en) | 2014-06-16 | 2014-06-16 | Unidirectivity MEMS microphone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420318349.5U CN203933949U (en) | 2014-06-16 | 2014-06-16 | Unidirectivity MEMS microphone |
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| Publication Number | Publication Date |
|---|---|
| CN203933949U true CN203933949U (en) | 2014-11-05 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420318349.5U Expired - Fee Related CN203933949U (en) | 2014-06-16 | 2014-06-16 | Unidirectivity MEMS microphone |
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| CN (1) | CN203933949U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016176993A1 (en) * | 2015-05-06 | 2016-11-10 | 歌尔声学股份有限公司 | Mems microphone encapsulation structure |
| CN109040927A (en) * | 2018-10-26 | 2018-12-18 | 歌尔科技有限公司 | A kind of directional microphone and sound collection equipment |
| CN110475193A (en) * | 2019-09-05 | 2019-11-19 | 朝阳聚声泰（信丰）科技有限公司 | It is a kind of to be singly directed toward MEMS microphone and its production method |
| US10771904B2 (en) | 2018-01-24 | 2020-09-08 | Shure Acquisition Holdings, Inc. | Directional MEMS microphone with correction circuitry |
-
2014
- 2014-06-16 CN CN201420318349.5U patent/CN203933949U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016176993A1 (en) * | 2015-05-06 | 2016-11-10 | 歌尔声学股份有限公司 | Mems microphone encapsulation structure |
| US10771904B2 (en) | 2018-01-24 | 2020-09-08 | Shure Acquisition Holdings, Inc. | Directional MEMS microphone with correction circuitry |
| US11463816B2 (en) | 2018-01-24 | 2022-10-04 | Shure Acquisition Holdings, Inc. | Directional MEMS microphone with correction circuitry |
| CN109040927A (en) * | 2018-10-26 | 2018-12-18 | 歌尔科技有限公司 | A kind of directional microphone and sound collection equipment |
| CN109040927B (en) * | 2018-10-26 | 2024-02-06 | 歌尔科技有限公司 | Directional microphone and sound collection equipment |
| CN110475193A (en) * | 2019-09-05 | 2019-11-19 | 朝阳聚声泰（信丰）科技有限公司 | It is a kind of to be singly directed toward MEMS microphone and its production method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141105 Termination date: 20180616 |