CN109511067B - Capacitance microphone - Google Patents
Capacitance microphone Download PDFInfo
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- CN109511067B CN109511067B CN201811472303.8A CN201811472303A CN109511067B CN 109511067 B CN109511067 B CN 109511067B CN 201811472303 A CN201811472303 A CN 201811472303A CN 109511067 B CN109511067 B CN 109511067B
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- back plate
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- condenser microphone
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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
Abstract
The present invention relates to a condenser microphone, comprising: vibrating the membrane layer; the back plate is supported on the surface of the vibration film layer in an insulating mode, and the back plate and the vibration film layer form a variable capacitor; the backplate includes first insulating layer, conducting layer and the second insulating layer that piles up the setting, the conducting layer is located between first insulating layer and the second insulating layer, the rete shakes with the first insulating layer of backplate is relative. The reliability of the condenser microphone is enhanced.
Description
Technical Field
The invention relates to the technical field of silicon microphones, in particular to a capacitive microphone.
Background
The MEMS (Micro-Electro-Mechanical System) technology is a high and new technology developed at a high speed in recent years, and it adopts an advanced semiconductor manufacturing process to implement the batch manufacturing of devices such as sensors and drivers, and compared with the corresponding conventional devices, the MEMS device has very obvious advantages in terms of volume, power consumption, weight and price. Major examples of applications of MEMS devices on the market include pressure sensors, accelerometers, and silicon microphones.
The silicon microphone manufactured by adopting the MEMS technology has the advantages of miniaturization, performance, reliability, environmental tolerance, cost and mass production compared with ECM, and rapidly occupies the markets of consumer electronics products such as mobile phones, PDAs, MP3 and hearing aids. Silicon microphones fabricated using MEMS technology typically have a movable diaphragm arranged in parallel with a solid backplate, the diaphragm and backplate forming a variable capacitor. The diaphragm moves in response to incident acoustic energy to change the variable capacitance and thereby generate an electrical signal indicative of the incident acoustic energy.
With the technical development of capacitive micro-silicon microphones, the silicon microphones are required to be smaller in size and lower in cost, and the reliability of the capacitive microphones needs to be further improved.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a capacitive microphone, which improves the reliability of a silicon microphone.
In order to solve the above problems, the present invention provides a condenser microphone including: vibrating the membrane layer; the back plate is supported on the surface of the vibration film layer in an insulating mode, and the back plate and the vibration film layer form a variable capacitor; the backplate includes first insulating layer, conducting layer and the second insulating layer that piles up the setting, the conducting layer is located between first insulating layer and the second insulating layer, the rete shakes with the first insulating layer of backplate is relative.
Optionally, the diaphragm layer is provided with an air leakage hole penetrating through the diaphragm layer.
Optionally, the thickness of the second insulating layer is smaller than that of the first insulating layer.
Optionally, the second insulating layer covers at least a surface of the conductive layer.
Optionally, the second insulating layer further covers sidewalls of the conductive layer and the first insulating layer.
Optionally, the back plate is provided with a sound hole.
Optionally, the air release hole is opposite to the sound hole at the outermost periphery of the back plate.
Optionally, a protruding point is arranged on the surface of one side, facing the diaphragm layer, of the back plate.
Optionally, the protruding points are disposed on the surface of the back plate between adjacent sound holes.
Optionally, the shape of the air leakage hole comprises at least one of a circle, a square or a fine groove.
Optionally, the vibration film layer further comprises a substrate, the surface of the other side of the vibration film layer is supported on the surface of the substrate in an insulating mode, and a back cavity opposite to the vibration film layer is formed in the substrate.
The back plate of the condenser microphone comprises the conducting layer and the two insulating layers, so that the strength of the back plate is improved, meanwhile, the failure of the microphone caused by particle problems in the using process is avoided, and the reliability of the microphone is further improved. Furthermore, an air leakage hole is formed in the diaphragm layer of the microphone, so that air pressure in the cavity of the microphone can be effectively balanced, and the reliability of the microphone is improved.
Drawings
Fig. 1 to 2 are schematic structural views of a condenser microphone according to an embodiment of the present invention;
fig. 3 to 4 are schematic structural diagrams of a condenser microphone according to an embodiment of the present invention.
Detailed Description
The following describes in detail a specific embodiment of a condenser microphone according to the present invention with reference to the accompanying drawings.
Please refer to fig. 1 and fig. 2, which are schematic cross-sectional views of a condenser microphone according to an embodiment of the present invention.
The condenser microphone includes: a substrate 100 having a back cavity 101; the vibration film layer 200 is suspended above the back cavity 101 of the substrate 100, and the vibration film layer 200 is supported on the surface of the substrate 100 in an insulating manner; the backplate 300 is located above the diaphragm layer 200, the backplate 300 is supported on the surface of the diaphragm layer 200 in an insulating manner, and the backplate 300 and the diaphragm layer 200 form a variable capacitor.
The substrate 100 may be a semiconductor substrate or a glass substrate, and in this embodiment, the substrate 100 is a silicon substrate.
The edge of the diaphragm layer 200 is supported on the surface of the substrate 100 by the first support layer 110, so that the diaphragm layer 200 is suspended above the back cavity 101, and the first support layer 110 may be a residual portion of the sacrificial layer after the sacrificial layer is released in the process of forming the condenser microphone. The diaphragm layer 200 is made of a conductive material and serves as a lower electrode of the first variable capacitor. In this embodiment, the material of the diaphragm layer 200 is polysilicon. The thickness of the vibration film layer 200 is relatively low, and the vibration film layer can vibrate up and down under the action of sound waves, so that the capacitance value of the variable capacitor formed by the vibration film layer 200 and the back plate 300 changes. The rigidity of the diaphragm layer 200 can be adjusted by adjusting the thickness of the diaphragm layer 200, thereby adjusting the sensitivity of capacitance change. In this embodiment, the material of the first support layer 110 is silicon oxide; in other specific embodiments, the material of the first support layer 110 may also be an insulating material such as silicon nitride, silicon oxynitride, silicon oxycarbide, or the like.
The diaphragm layer 200 is further provided with an air leakage hole 201. The air leakage hole 201 is used for balancing air pressure in the microphone cavity, and the working performance of the microphone is prevented from being influenced by overlarge or undersize air pressure in the microphone cavity when the environment changes in the microphone packaging process. The air leakage holes 201 are evenly and symmetrically distributed at the peripheral edge positions of the vibrating diaphragm layer 200, and air pressure in the cavity can be evenly adjusted.
In this embodiment, the air release holes 201 are U-shaped fine grooves uniformly distributed on the outer side of the diaphragm layer 200, so as to balance the air pressure at each position in the microphone cavity. In other embodiments, the air leakage hole 201 may also be in the shape of a long strip, a crossed long groove, a circle, a square or a polygon. The size of the air release hole 201 is generally small, so that the resistance of the diaphragm layer 200 to sound waves is prevented from being reduced.
In this embodiment, the edge of the vibration film layer 200 is completely and fixedly supported on the surface of the substrate 100 by a circle, so as to form a full-film fixed support structure, which has high reliability and is not easy to break or damage, and the rigidity of the vibration film layer 200 can be adjusted by the film thickness and the internal stress of the vibration film layer 200. In other embodiments of the present invention, only a part of the edge of the diaphragm layer 200 may be supported.
The edge of the backplate 300 is supported on the surface of the diaphragm layer 200 through the second supporting layer 120, so that the backplate 300 is suspended above the diaphragm layer 200, and the backplate 300 and the diaphragm layer 200 form a variable capacitor. The second support layer 120 may be a remaining portion of the sacrificial layer after releasing the sacrificial layer in the process of forming the condenser microphone. In this embodiment, the material of the second support layer 120 is silicon oxide; in other specific embodiments, the material of the second support layer 120 may also be an insulating material such as silicon nitride, silicon oxynitride, silicon oxycarbide, and the like.
In this embodiment, the edge of the backplate 300 is completely and fixedly supported on the surface of the diaphragm layer 200 to form a full-film fixing and supporting structure, which has high reliability and is not easy to break or damage. In other embodiments of the present invention, only a part of the edge of the back plate 300 may be supported.
The back plate 300 is further provided with a sound hole 304, so that after the sound wave makes the diaphragm layer 200 vibrate, the air pressure change in the variable capacitor can be released outwards through the sound hole 304, and the microphone is prevented from being damaged due to overlarge air pressure change.
In this embodiment, the surface of the back plate 300 is further provided with bumps 305. In this embodiment, the bumps 305 are disposed on the surface of the side of the backplate 300 facing the vibration layer 200, and when the diaphragm layer 200 deforms toward the backplate 300, the bumps 305 can prevent the vibration layer 200 from adhering to the backplate 300 and affecting the performance of the microphone. Preferably, the sound holes 304 are disposed in the middle of the backplate 300, and the surface of the backplate 300 facing the diaphragm layer 200 between adjacent sound holes 304 is provided with the bumps 305.
The back plate 300 has conductivity as an upper electrode of the variable capacitor. In order to improve the strength of the backplate and prevent the backplate 300 from deforming during use, the backplate 300 may be a composite structure including a conductive layer and at least one insulating layer, and the insulating layer serves as a supporting layer to enhance the strength of the backplate 300. In this embodiment, the backplate 300 includes a first insulating layer 301, a conductive layer 302, and a second insulating layer 303, and the conductive layer 302 is located between the first insulating layer 301 and the second insulating layer 303. Specifically, the material of the first insulating layer 301 and the second insulating layer 303 may be at least one of insulating materials such as silicon nitride, silicon oxide, and silicon oxynitride. In this embodiment, the first insulating layer 301 and the second insulating layer 303 are made of silicon nitride. Since the silicon nitride has high hardness, the backplate 300 is used as a fixed electrode and is not easy to deform, thereby improving the reliability of the microphone.
In this specific embodiment, the thickness of the first insulating layer 301 is greater than the thickness of the second insulating layer 303, and the thickness of the first insulating layer 301 is greater for supporting the backplate 300 and preventing the backplate 300 from sinking toward the diaphragm layer 200; the thickness of the second insulating layer 303 is small, and the second insulating layer mainly plays a role in insulating and protecting the conductive layer 302, so that the influence of microphone leakage caused by the connection of the diaphragm layer 200 and the backplate 300 by particles introduced in the process is avoided, and even the microphone may fail. The thickness of the second insulating layer 303 is required to be in a nanometer level, so that the phenomenon that the back plate 300 deforms towards the diaphragm layer 200 due to gravity and stress is avoided. In some embodiments, the second insulating layer 303 may have a thickness of 5nm to 500 nm.
In this embodiment, the second insulating layer 303 also covers the sidewalls of the first insulating layer 301 and the conductive layer 302 at the edge of the sound hole 404, so as to protect the surface and sidewalls of the conductive layer 302 completely and minimize particle-induced failures.
In other embodiments, an insulating layer may be covered on only one side of the conductive layer 302.
Please refer to fig. 3 and fig. 4, which are schematic cross-sectional views of a condenser microphone according to another embodiment of the present invention.
In this embodiment, the backplate 300 of the condenser microphone includes a first insulating layer 301, a conductive layer 302, and a second insulating layer 402. In this embodiment, the second insulating layer 402 covers only the surface of the conductive layer 302, and forms a sandwich structure with the conductive layer 302 and the first insulating layer 301. Although the sidewalls of the conductive layer 302 are not protected by the second insulating layer 402, the probability of failure is reduced because the conductive layer 302 has a lower thickness, smaller sidewall size, and a lower probability of particle residue.
The back plate of the condenser microphone of the above specific embodiment includes the conductive layer and the two insulating layers, so that the strength of the back plate is improved, failure of the microphone caused by particle problems in the use process is avoided, and the reliability of the microphone is further improved. Furthermore, an air leakage hole is formed in the diaphragm layer of the microphone, so that air pressure in the cavity of the microphone can be effectively balanced, and the reliability of the microphone is improved.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (7)
1. A condenser microphone, comprising:
vibrating the membrane layer;
the back plate is supported on the surface of the vibration film layer in an insulating mode, and the back plate and the vibration film layer form a variable capacitor; it is characterized in that the preparation method is characterized in that,
the back plate comprises a first insulating layer, a conducting layer and a second insulating layer which are stacked, the conducting layer is located between the first insulating layer and the second insulating layer, the vibrating membrane layer is opposite to the first insulating layer of the back plate, and the thickness of the second insulating layer is smaller than that of the first insulating layer;
the back plate is provided with a sound hole;
the diaphragm layer is provided with an air leakage hole penetrating through the diaphragm layer, and the air leakage hole is opposite to the outermost sound hole of the back plate.
2. The condenser microphone of claim 1, wherein the second insulating layer covers at least a surface of the conductive layer.
3. The condenser microphone of claim 2, wherein the second insulating layer further covers sidewalls of the conductive layer and the first insulating layer.
4. The condenser microphone of claim 1, wherein a surface of the back plate facing the diaphragm layer is provided with a convex point.
5. The condenser microphone of claim 4, wherein the bumps are disposed on the surface of the backplate between adjacent sound holes.
6. The condenser microphone of claim 1, wherein the shape of the air leakage hole comprises at least one of a circle, a square or a fine groove.
7. The condenser microphone of claim 1, further comprising a substrate, wherein the other side surface of the diaphragm layer is supported on the surface of the substrate in an insulating manner, and a back cavity opposite to the diaphragm layer is formed in the substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811472303.8A CN109511067B (en) | 2018-12-04 | 2018-12-04 | Capacitance microphone |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201811472303.8A CN109511067B (en) | 2018-12-04 | 2018-12-04 | Capacitance microphone |
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| Publication Number | Publication Date |
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| CN109511067A CN109511067A (en) | 2019-03-22 |
| CN109511067B true CN109511067B (en) | 2020-12-25 |
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Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109951781B (en) * | 2019-04-03 | 2020-06-30 | 创达电子(潍坊)有限公司 | Silicon microphone structure |
| WO2021134333A1 (en) * | 2019-12-30 | 2021-07-08 | 瑞声声学科技(深圳)有限公司 | Mems microphone |
| CN111277937B (en) * | 2020-02-13 | 2021-03-12 | 中芯集成电路制造(绍兴)有限公司 | MEMS microphone and manufacturing method thereof |
| CN112104961B (en) * | 2020-09-21 | 2022-04-15 | 无锡韦感半导体有限公司 | Micro-electro-mechanical structure and MEMS microphone |
| CN213754953U (en) * | 2020-09-28 | 2021-07-20 | 苏州敏芯微电子技术股份有限公司 | Micro-electromechanical structure, electronic cigarette switch and electronic cigarette |
| CN112702684B (en) * | 2020-12-29 | 2022-08-19 | 瑞声声学科技(深圳)有限公司 | Silicon-based microphone and manufacturing method thereof |
| CN112689229B (en) * | 2020-12-29 | 2022-06-03 | 瑞声声学科技(深圳)有限公司 | Silicon-based microphone and manufacturing method thereof |
| CN112822616A (en) * | 2021-01-19 | 2021-05-18 | 潍坊歌尔微电子有限公司 | Sensing chip and MEMS sensor |
| CN112887895B (en) * | 2021-01-26 | 2022-06-07 | 苏州工业园区纳米产业技术研究院有限公司 | Process method for adjusting pull-in voltage of MEMS microphone |
| CN114501274A (en) * | 2022-01-29 | 2022-05-13 | 华润微电子控股有限公司 | Capacitive MEMS microphone and manufacturing method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103281661A (en) * | 2013-05-09 | 2013-09-04 | 上海集成电路研发中心有限公司 | MEMS (micro electro mechanical system) microphone structure and manufacturing method of MEMS microphone structure |
| CN103297907A (en) * | 2012-02-23 | 2013-09-11 | 苏州敏芯微电子技术有限公司 | Capacitive mini-type microphone and manufacturing method thereof |
| CN103402160A (en) * | 2013-07-10 | 2013-11-20 | 瑞声声学科技(深圳)有限公司 | MEMS (micro electro mechanical system) microphone and work control method of MEMS microphone |
| CN105744453A (en) * | 2014-12-24 | 2016-07-06 | 英飞凌科技股份有限公司 | Capacitive Microphone With Insulated Conductive Plate |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130039504A (en) * | 2011-10-12 | 2013-04-22 | 한국전자통신연구원 | Mems microphone and manufacturing method thereof |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103297907A (en) * | 2012-02-23 | 2013-09-11 | 苏州敏芯微电子技术有限公司 | Capacitive mini-type microphone and manufacturing method thereof |
| CN103281661A (en) * | 2013-05-09 | 2013-09-04 | 上海集成电路研发中心有限公司 | MEMS (micro electro mechanical system) microphone structure and manufacturing method of MEMS microphone structure |
| CN103402160A (en) * | 2013-07-10 | 2013-11-20 | 瑞声声学科技(深圳)有限公司 | MEMS (micro electro mechanical system) microphone and work control method of MEMS microphone |
| CN105744453A (en) * | 2014-12-24 | 2016-07-06 | 英飞凌科技股份有限公司 | Capacitive Microphone With Insulated Conductive Plate |
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