Diaphragm for MEMS microphone and MEMS microphone
By setting pressure relief slots and ports of a specific shape on the silicon microphone diaphragm, the air pressure release path was optimized, the problem of diaphragm rupture under high stress was solved, and better acoustic performance and mechanical strength were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AAC TECHNOLOGIES PTE LTD
- Filing Date
- 2025-12-29
- Publication Date
- 2026-05-05
AI Technical Summary
In the design of existing silicon microphones, it is challenging to achieve greater air release while suppressing the formation of high stress, especially since the diaphragm is prone to breakage under high sound pressure conditions.
A pressure relief section with a first pressure relief slit and a second pressure relief slit is provided on the diaphragm. The first pressure relief slit is a wavy or circular structure, and the second pressure relief slit is located at the end of the first pressure relief slit. The pressure relief sections are evenly distributed near the edge of the diaphragm to form multiple pressure relief ports to optimize the air pressure release path.
It reduces the maximum stress on the diaphragm, improves the diaphragm's compliance and air pressure release effect, reduces the risk of diaphragm rupture under high sound pressure, and maintains good acoustic performance.
Smart Images
Figure CN121985274A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microelectromechanical systems (MEMS) technology, and in particular to a diaphragm for a MEMS microphone and a MEMS microphone. Background Technology
[0002] One of the most widely used and high-performance microphones is the Micro-Electro-Mechanical-System Microphone (MEMS microphone), also known as a silicon-based microphone or silicon microphone because it is made of silicon-based semiconductor materials. Its package size is smaller than that of traditional electret microphones, and its applications are becoming increasingly widespread.
[0003] Existing silicon microphones include a substrate with a back cavity and a capacitor system disposed on and insulated from the substrate. The capacitor system includes a diaphragm and a backplate spaced apart from the diaphragm. When the silicon microphone is powered on, the backplate and the diaphragm acquire opposite charges, thus forming a capacitor. When the diaphragm vibrates under the influence of sound waves, the distance between the diaphragm and the backplate changes, causing a change in the capacitance of the capacitor system. This converts the sound wave signal into an electrical signal, enabling the microphone to perform its function.
[0004] The internal and external spaces of a silicon microphone are divided into two parts: the space on the back cavity side is called the front cavity, and the space on the back plate side is called the rear cavity. A slit is designed on the diaphragm; when the diaphragm vibrates, the front and rear cavities are connected through this slit, allowing air to flow from the front cavity to the rear cavity. However, the amount of air released depends on the design of the slit, requiring a trade-off between higher stress formation and stronger air release. The point of greatest stress is always at the end of the slit. How to suppress high stress formation while achieving greater air release has become a challenge in designing a silicon microphone. Summary of the Invention
[0005] The purpose of this invention is to provide a diaphragm for a MEMS microphone and a MEMS microphone to solve the technical problems in the prior art, which can reduce maximum stress and maintain / improve the compliance of the diaphragm.
[0006] In a first aspect, the present invention provides a diaphragm for a MEMS microphone, comprising: Diaphragm body; A pressure relief section is provided on the diaphragm body. The pressure relief section includes a first pressure relief slit and a second pressure relief slit. The end of the first pressure relief slit has a first pressure relief port. The second pressure relief slit is provided corresponding to the first pressure relief port. The end of the second pressure relief slit forms a second pressure relief port. The line connecting the two second pressure relief ports intersects with the first pressure relief slit or the first pressure relief port.
[0007] In the diaphragm for a MEMS microphone as described above, preferably, the first pressure relief slit has a wavy structure, and a first pressure relief port is formed at each of the opposite ends of the first pressure relief slit, with a second pressure relief slit corresponding to each of the first pressure relief ports.
[0008] In the diaphragm for a MEMS microphone described above, preferably, the first pressure relief slit is a circular structure with a notch, and a first pressure relief port is formed at each of the opposite ends of the first pressure relief slit, with a second pressure relief slit corresponding to each of the first pressure relief ports.
[0009] In the diaphragm for a MEMS microphone as described above, preferably, the second pressure relief slit is a circular structure with a notch, and a second pressure relief port is formed at each of the opposite ends of the second pressure relief slit. The first pressure relief port extends from the notch into the circular structure, or the first pressure relief port is located on the line connecting the two second pressure relief ports.
[0010] In the diaphragm for a MEMS microphone as described above, preferably, the second pressure relief slit is composed of a plurality of spaced-apart components, and the second pressure relief port is formed at the ends of the components.
[0011] The diaphragm for a MEMS microphone as described above preferably further includes a third pressure relief slit, which is disposed corresponding to the second pressure relief port. The end of the third pressure relief slit forms a third pressure relief port, and the line connecting the two third pressure relief ports intersects with the second pressure relief slit or the second pressure relief port.
[0012] In the diaphragm for a MEMS microphone described above, preferably, the first pressure relief port, the second pressure relief port, and the third pressure relief port are all circular ports. In the diaphragm for a MEMS microphone as described above, preferably, multiple pressure relief sections are provided, and the multiple pressure relief sections are evenly spaced around the axis of the diaphragm body. In the diaphragm for a MEMS microphone as described above, preferably, the pressure relief portion is disposed near the edge of the diaphragm body.
[0013] Secondly, the present invention provides a MEMS microphone, including the aforementioned diaphragm.
[0014] Compared with the prior art, the present invention provides a pressure relief part with a first pressure relief slot and a second pressure relief slot on the diaphragm, with the second pressure relief slot located at the end of the first pressure relief slot, thereby reducing the maximum stress and maintaining / improving the compliance of the diaphragm, while also improving the air pressure release effect. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of a slit structure in the prior art; Figure 2 This is a schematic diagram of the structure of the first type of pressure relief section provided in the embodiments of the present invention. Figure 1 ; Figure 3 yes Figure 2 The simulation results of the pressure load and the maximum stress of the diaphragm are shown in the diagram, comparing the structure of the pressure relief section with that of the pressure relief section after the second pressure relief seam is removed. Figure 4 yes Figure 2 The simulation results of the pressure load and the maximum displacement of the diaphragm are shown in the figure, comparing the structure of the pressure relief section with that of the pressure relief section after the second pressure relief seam is removed. Figure 5 This is a schematic diagram of the structure of the first type of pressure relief section provided in the embodiments of the present invention. Figure 2 ; Figure 6 yes Figure 5 The simulation results of the pressure load and the maximum stress of the diaphragm are shown in the diagram, comparing the structure of the pressure relief section with that of the pressure relief section after the second pressure relief seam is removed. Figure 7 yes Figure 5 The simulation results of the pressure load and the maximum displacement of the diaphragm are shown in the figure, comparing the structure of the pressure relief section with that of the pressure relief section after the second pressure relief seam is removed. Figure 8 This is a schematic diagram of the structure of the second type of pressure relief section provided in the embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the third type of pressure relief section provided in the embodiment of the present invention; Figure 10 This is a schematic diagram of the fourth type of pressure relief section provided in the embodiments of the present invention.
[0016] Explanation of reference numerals in the attached drawings: 1-First pressure relief seam, 2-Second pressure relief seam, 3-Third pressure relief seam, 4-First pressure relief port, 5-Second pressure relief port, 6-Third pressure relief port, 100-Slit. Detailed Implementation
[0017] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0018] Existing silicon microphones include a substrate with a back cavity and a capacitor system disposed on and insulated from the substrate. The capacitor system includes a diaphragm and a backplate spaced apart from the diaphragm. When the silicon microphone is powered on, the backplate and the diaphragm acquire opposite charges, thus forming a capacitor. When the diaphragm vibrates under the influence of sound waves, the distance between the diaphragm and the backplate changes, causing a change in the capacitance of the capacitor system. This converts the sound wave signal into an electrical signal, enabling the microphone to perform its corresponding function.
[0019] The internal and external spaces of a silicon microphone are divided into two parts: the space on the back side is called the front cavity, and the space on the back plate side is called the rear cavity. (See reference...) Figure 1 As shown, a slit 100 is designed on the diaphragm. When the diaphragm vibrates, the front cavity and the rear cavity are connected through the slit 100, which allows air to flow from the front cavity to the rear cavity, thus solving the problem that traditional MEMS microphone diaphragms are prone to breakage under strong airflow impact. However, the deformation of the diaphragm will cause stress concentration, and the point of greatest stress is always at the end of the slit 100. This can easily cause the two ends of the slit 100 to tear, leading to microphone failure.
[0020] To improve the mechanical strength of the diaphragm and achieve greater air release while suppressing high stress formation, this application provides a diaphragm for a MEMS microphone, including a diaphragm body and a pressure relief portion disposed on the diaphragm body, wherein: The pressure relief section includes a first pressure relief slit 1 and a second pressure relief slit 2. Both the first pressure relief slit 1 and the second pressure relief slit 2 serve as outlets for air flow to improve the effect of air pressure release and ensure that the diaphragm can respond quickly under high pressure.
[0021] The first pressure relief seam 1 has a first pressure relief port 4 at its end, and the second pressure relief seam 2 is provided corresponding to the first pressure relief port 4. The first pressure relief seam 1 has at least two first pressure relief ports 4, and a second pressure relief seam 2 is provided near each first pressure relief port 4, thereby enhancing the elasticity of the diaphragm located at the first pressure relief port 4, thereby reducing the maximum stress and maintaining / improving the compliance of the diaphragm, and also improving the air pressure release effect.
[0022] The end of the second pressure relief slit 2 is formed with a second pressure relief port 5. Each second pressure relief slit 2 has at least two second pressure relief ports 5. There is a preset gap between the two second pressure relief ports 5 to form a folded shaft edge. When subjected to sound pressure, the diaphragm in the area surrounded by the second slit tilts up with this folded shaft edge as the fulcrum to form an air flow path. The design of the folded shaft edge allows the diaphragm to deform flexibly when depressurized, while maintaining its structural integrity.
[0023] In the embodiments provided by the present invention, reference is made to Figure 2 , Figure 5 , Figure 8 , Figure 9 as well as Figure 10 As shown, the line connecting the two second pressure relief ports 5 intersects with the first pressure relief seam 1 or the first pressure relief port 4, thereby achieving the purpose of pressure relief. This reduces the maximum stress at the first pressure relief port 4 of the first pressure relief seam 1, thereby reducing the risk of diaphragm damage due to stress concentration. At the same time, it maintains or improves the compliance of the diaphragm. Without adding additional complex structures, the protection and performance improvement of the diaphragm are achieved by optimizing the pressure relief path.
[0024] In one feasible implementation, multiple pressure relief sections are provided to increase the number of pressure release paths. The multiple pressure relief sections are evenly distributed around the axis of the diaphragm body, which can ensure that the pressure of each part of the diaphragm can be evenly released through the pressure relief sections under the action of sound pressure. This can effectively reduce the local stress concentration of the diaphragm under the impact of high sound pressure, thereby reducing the risk of diaphragm rupture and improving the reliability of the microphone in complex environments.
[0025] Furthermore, the pressure relief section is located close to the edge of the diaphragm body, which can more effectively handle pressure changes in the edge area. The edge of the diaphragm is usually where stress concentration is more obvious when subjected to sound pressure impact. Placing the pressure relief section here can quickly alleviate stress concentration in the edge area and reduce the risk of diaphragm rupture under high sound pressure impact. After the pressure relief capacity of the edge area of the diaphragm is enhanced, the overall performance of the diaphragm is more balanced, thus better adapting to high sound pressure environment while maintaining good acoustic performance.
[0026] Reference Figure 2 , Figure 5 , Figure 8 , Figure 9 as well as Figure 10 As shown, the first pressure relief joint 1 has various structural forms, such as... Figure 2 and Figure 5 The wavy structure shown, or, Figures 8 to 10 The circular structure with a notch shown can be used to design more deformable structures by those skilled in the art based on the structure of the first pressure relief seam 1 provided in the embodiments of this application, and no limitation is made here.
[0027] Reference Figure 2 as well as Figure 5As shown, the first pressure relief seam 1 has a wave-shaped structure. The wave-shaped structure of the first pressure relief seam 1 can provide more flexible deformation capability and increase the length of the pressure relief path, thereby more effectively dispersing stress and better alleviating the stress concentration problem at the edge of the diaphragm. A first pressure relief port 4 is formed at each of the opposite ends of the first pressure relief seam 1, which can ensure that the sound pressure can be released quickly through multiple ports, further optimizing the pressure relief effect. A second pressure relief seam 2 is provided near each first pressure relief port 4, thereby enhancing the elasticity of the diaphragm located at the first pressure relief port 4, reducing the maximum stress and maintaining / improving the compliance of the diaphragm, while also improving the air pressure release effect.
[0028] The number and density of crests and troughs within the wavy first pressure relief seam 1 can be determined according to actual needs and are not limited here. For example Figure 2 The first pressure relief seam 1 shown includes a crest and a trough. Figure 3 The first pressure relief joint 1 shown includes two troughs and a crest connecting the two troughs, and the second pressure relief joint 2 is provided at the end of the trough.
[0029] Reference Figure 3 As shown, Figure 3 yes Figure 2 The simulation results of the pressure load and the maximum diaphragm stress are shown in the figure, which compares the structure of the pressure relief section with the structure of the pressure relief section after the removal of the second pressure relief seam 2. The horizontal axis in the figure is the pressure load (unit: Pa), and the vertical axis is the maximum diaphragm stress (Maximum VP Stress, Gpa).
[0030] The solid line labeled A1 in the diagram reflects what? Figure 2 The stress variation with pressure after the removal of the second pressure relief joint 2 in the pressure relief section is shown in the figure. The solid line labeled A2 in the figure reflects the stress variation with pressure. Figure 2 The stress in the pressure relief section shown varies with pressure. The solid line labeled A2 is always lower than the solid line labeled A1, especially at high pressure (>800000 Pa). Figure 2 The second pressure relief slot 2 structure of the pressure relief section shown improves the ventilation path, reduces internal air pressure accumulation, and thus reduces stress concentration.
[0031] Reference Figure 4 As shown, Figure 4 yes Figure 2 The simulation results of the pressure load and the maximum displacement of the diaphragm are shown in the figure. The horizontal axis of the figure is the pressure load (Pa), and the vertical axis is the maximum displacement of the diaphragm (µm).
[0032] The solid line labeled B1 in the diagram reflects what? Figure 2 The stress variation with pressure after the removal of the second pressure relief joint 2 in the pressure relief section is shown in the figure. The solid line labeled B2 in the figure reflects the stress variation with pressure. Figure 2 The stress in the pressure relief section shown varies with pressure, with the solid line labeled B2 consistently higher than the solid line labeled B1. Increased displacement means the diaphragm is more prone to deformation, which is beneficial for acoustic sensitivity or MEMS signal detection.
[0033] Reference Figure 6 As shown, Figure 6 yes Figure 5 The simulation results of the pressure load and the maximum diaphragm stress are shown in the figure, which compares the structure of the pressure relief section with the structure of the pressure relief section after the removal of the second pressure relief seam 2. The horizontal axis in the figure is the pressure load (unit: Pa), and the vertical axis is the maximum diaphragm stress (Maximum VP Stress, Gpa).
[0034] The solid line labeled C1 in the diagram reflects... Figure 5 The stress variation with pressure after the removal of the second pressure relief joint 2 in the pressure relief section is shown in the figure. The solid line labeled C2 in the figure reflects the stress variation with pressure. Figure 5 The stress in the pressure relief section shown varies with pressure. The solid line labeled C2 is always lower than the solid line labeled C1, especially at high pressure (>800000 Pa). Figure 5 The second pressure relief slot 2 structure of the pressure relief section shown improves the ventilation path, reduces internal air pressure accumulation, and thus reduces stress concentration.
[0035] Reference Figure 6 As shown, Figure 6 yes Figure 5 The simulation results of the pressure load and the maximum displacement of the diaphragm are shown in the figure. The horizontal axis of the figure is the pressure load (Pa), and the vertical axis is the maximum displacement of the diaphragm (µm).
[0036] The solid line labeled D1 in the diagram reflects... Figure 5 The stress variation with pressure after the removal of the second pressure relief joint 2 in the pressure relief section is shown in the figure. The solid line labeled D2 in the figure reflects the stress variation with pressure. Figure 5 The stress in the pressure relief section shown varies with pressure, with the solid line labeled D2 always higher than the solid line labeled D1. Increased displacement means the diaphragm is more prone to deformation, which is beneficial for acoustic sensitivity or MEMS signal detection.
[0037] Reference Figures 8 to 10As shown, the first pressure relief seam 1 is a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, allowing the diaphragm to deform flexibly during pressure relief and maintain the diaphragm's conformity.
[0038] The first pressure relief seam 1 forms a folded shaft edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up with this folded shaft edge as a fulcrum to form an airflow path, which can quickly release the pressure inside the diaphragm.
[0039] In the embodiments provided by the present invention, the second pressure relief seam 2 is preferably a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, allowing the diaphragm to deform flexibly during pressure relief and maintain its conformity.
[0040] The second pressure relief seam 2 has a second pressure relief port 5 at each of its opposite ends. The first pressure relief port 4 extends into the circular structure from the notch, or the first pressure relief port 4 is located on the line connecting the two second pressure relief ports 5, thereby further optimizing the stress distribution and ensuring a more direct and efficient pressure release path. The second pressure relief seam 2 forms a folded shaft edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up with this folded shaft edge as a fulcrum to form an airflow path, which can quickly release the pressure inside the diaphragm, while reducing stress concentration at the first pressure relief port 4, preventing the first pressure relief seam 1 from tearing, and further protecting the diaphragm from damage caused by high sound pressure impact.
[0041] Furthermore, the second pressure relief seam 2 is composed of multiple spaced-apart sections, with the second pressure relief port 5 formed at the ends of these sections. This split design can further optimize the pressure relief effect, especially in high sound pressure environments, providing a more flexible pressure relief path and reducing the risk of diaphragm rupture.
[0042] In the embodiments provided by the present invention, the first pressure relief port 4 and the second pressure relief port 5 are preferably circular ports. The boundary stress distribution of the circular port is relatively uniform, without sharp edges or angles, thereby reducing stress concentration. This can effectively prevent cracks from forming on the corresponding end face when high air pressure impacts the pressure relief seam, further improving the mechanical strength of the diaphragm. At the same time, the circular port has better airflow permeability, which can more quickly balance the pressure difference inside and outside the diaphragm.
[0043] The following provides several types of pressure relief parts. It is understood that those skilled in the art can make more embodiments based on the pressure relief part structures provided below, all of which fall within the scope of the inventive concept of this application.
[0044] The first type of pressure relief section Reference Figure 2 as well as Figure 5As shown, this is a pressure relief section of the first type provided in an embodiment of the present invention. In this embodiment, the first pressure relief seam 1 is a wave-shaped structure. The wave-shaped structure of the first pressure relief seam 1 can provide more flexible deformation capability and increase the length of the pressure relief path, thereby more effectively dispersing stress and better alleviating the stress concentration problem at the edge of the diaphragm. A first pressure relief port 4 is formed at each of the opposite ends of the first pressure relief seam 1, thereby ensuring that the sound pressure can be released quickly through multiple ports, further optimizing the pressure relief effect. A second pressure relief seam 2 is provided near each first pressure relief port 4, thereby enhancing the elasticity of the diaphragm located at the first pressure relief port 4, thereby reducing the maximum stress and maintaining / improving the compliance of the diaphragm, and also improving the air pressure release effect.
[0045] The number and density of crests and troughs within the wavy first pressure relief seam 1 can be determined according to actual needs and are not limited here. For example Figure 2 The first pressure relief seam 1 shown includes a crest and a trough. Figure 5 The first pressure relief joint 1 shown includes two troughs and a crest connecting the two troughs, and the second pressure relief joint 2 is provided at the end of the trough.
[0046] Reference Figure 2 as well as Figure 5 As shown, the second pressure relief seam 2 is a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, allowing the diaphragm to deform flexibly during pressure relief and maintain its conformity.
[0047] The second pressure relief seam 2 has a second pressure relief port 5 at each of its opposite ends. The first pressure relief port 4 extends from the notch into the circular structure, thereby further optimizing the stress distribution and ensuring a more direct and efficient pressure release path. The second pressure relief seam 2 forms a folded shaft edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up with this folded shaft edge as a fulcrum to form an airflow path, which can quickly release the pressure inside the diaphragm. At the same time, it reduces the stress concentration at the first pressure relief port 4, avoids tearing of the first pressure relief seam 1, and further protects the diaphragm from damage caused by high sound pressure impact.
[0048] The second type of pressure relief section Reference Figure 8 As shown, this is the second type of pressure relief part provided in the embodiment of the present invention. The first pressure relief slot 1 is a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, so that the diaphragm can deform flexibly during pressure relief and maintain its conformity.
[0049] The first pressure relief seam 1 forms a folded shaft edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up with this folded shaft edge as a fulcrum to form an airflow path, which can quickly release the pressure inside the diaphragm and at the same time reduce the stress concentration at the first pressure relief port 4, thereby reducing local stress concentration and improving the durability of the diaphragm.
[0050] Continue to refer to Figure 8 As shown, the second pressure relief seam 2 is a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, allowing the diaphragm to deform flexibly during pressure relief and maintain its conformity.
[0051] The second pressure relief seam 2 has a second pressure relief port 5 at each of its opposite ends. The first pressure relief port 4 extends from the notch into the circular structure, thereby further optimizing the stress distribution and ensuring a more direct and efficient pressure release path. The second pressure relief seam 2 forms a folded shaft edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up with this folded shaft edge as a fulcrum to form an airflow path, which can quickly release the pressure inside the diaphragm. At the same time, it reduces the stress concentration at the first pressure relief port 4, avoids tearing of the first pressure relief seam 1, and further protects the diaphragm from damage caused by high sound pressure impact.
[0052] The third type of pressure relief section Reference Figure 9 As shown, this is the third type of pressure relief section provided in the embodiment of the present invention. In this type of pressure relief section, the second pressure relief seam 2 is a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, so that the diaphragm can deform flexibly during pressure relief and maintain its conformity.
[0053] The second pressure relief seam 2 has a second pressure relief port 5 at each of its opposite ends. The first pressure relief port 4 extends from the notch into the circular structure, thereby further optimizing the stress distribution and ensuring a more direct and efficient pressure release path. The second pressure relief seam 2 forms a folded shaft edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up with this folded shaft edge as a fulcrum to form an airflow path, which can quickly release the pressure inside the diaphragm. At the same time, it reduces the stress concentration at the first pressure relief port 4, avoids tearing of the first pressure relief seam 1, and further protects the diaphragm from damage caused by high sound pressure impact.
[0054] Furthermore, the second pressure relief seam 2 is composed of multiple spaced-apart sections, with the second pressure relief port 5 formed at the ends of these sections. This split design further optimizes the pressure relief effect, especially in high sound pressure environments, providing a more flexible pressure relief path.
[0055] The fourth type of pressure relief section Reference Figure 10As shown, this is the fourth type of pressure relief part provided in the embodiment of the present invention. The pressure relief part not only has a first pressure relief seam 1 and a second pressure relief seam 2, but also includes a third pressure relief seam 3. Through the design of multiple pressure relief seams, the stress on the diaphragm is further dispersed and the stress concentration is reduced. The third pressure relief seam 3 is set corresponding to the second pressure relief port 5. The end of the third pressure relief seam 3 forms a third pressure relief port 6, and the line connecting the two third pressure relief ports 6 intersects with the second pressure relief port 5.
[0056] The third pressure relief seam 3 is a circular structure with a notch. The presence of the notch makes the circular structure not completely closed, which facilitates air flow and diaphragm deformation, allowing the diaphragm to deform flexibly during pressure relief and maintain its conformity.
[0057] The third pressure relief seam 3 has a third pressure relief port 6 at each of its two opposite ends. The line connecting the two third pressure relief ports 6 intersects with the second pressure relief port 5, thereby further optimizing the stress distribution and ensuring a more direct and efficient pressure release path. The third pressure relief seam 3 forms a folded axial edge at the notch. When subjected to sound pressure, the diaphragm body inside the circular structure tilts up using this folded axial edge as a fulcrum to form an airflow path. This allows for rapid release of pressure inside the diaphragm, while simultaneously reducing stress concentration at the second pressure relief port 5, preventing tearing of the second pressure relief seam 2, and further protecting the diaphragm from damage caused by high sound pressure impacts.
[0058] Preferably, the third pressure relief port 6 is also a circular port. The boundary stress distribution of a circular port is relatively uniform, without sharp edges or angles, thereby reducing stress concentration. This can effectively prevent cracks from forming on the corresponding end face when high air pressure impacts the pressure relief seam, further improving the mechanical strength of the diaphragm. At the same time, the circular port has better airflow permeability, which can more quickly balance the pressure difference inside and outside the diaphragm.
[0059] Based on the diaphragm provided in the above embodiments, the present invention also provides a MEMS microphone. The MEMS microphone includes a substrate having a back cavity and a capacitor system disposed on the substrate and insulated from the substrate. The capacitor system includes the aforementioned diaphragm and a back plate spaced apart from the diaphragm. By providing a pressure relief portion having a first pressure relief slot 1 and a second pressure relief slot 2 on the diaphragm, the maximum stress can be reduced and the compliance of the diaphragm can be maintained / improved. At the same time, the air pressure release effect can also be improved, and the overall performance of the diaphragm is more balanced, so that the MEMS microphone can better adapt to high sound pressure environments while maintaining good acoustic performance.
[0060] The above description, based on the embodiments shown in the figures, details the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.
Claims
1. A diaphragm for a MEMS microphone, characterized in that, include: Diaphragm body; A pressure relief section is provided on the diaphragm body. The pressure relief section includes a first pressure relief slit and a second pressure relief slit. The end of the first pressure relief slit has a first pressure relief port. The second pressure relief slit is provided corresponding to the first pressure relief port. The end of the second pressure relief slit forms a second pressure relief port. The line connecting the two second pressure relief ports intersects with the first pressure relief slit or the first pressure relief port.
2. The diaphragm for a MEMS microphone according to claim 1, characterized in that, The first pressure relief seam has a wavy structure, and a first pressure relief port is formed at each of the opposite ends of the first pressure relief seam. A second pressure relief seam is provided near each of the first pressure relief ports.
3. The diaphragm for a MEMS microphone according to claim 1, characterized in that, The first pressure relief seam is a circular structure with a notch. A first pressure relief port is formed at each of the opposite ends of the first pressure relief seam, and a second pressure relief seam is provided near each of the first pressure relief ports.
4. The diaphragm for a MEMS microphone according to claim 1, characterized in that, The second pressure relief seam is a circular structure with a notch. A second pressure relief port is formed at each of the opposite ends of the second pressure relief seam. The first pressure relief port extends from the notch into the circular structure, or the first pressure relief port is located on the line connecting the two second pressure relief ports.
5. The diaphragm for a MEMS microphone according to claim 1, characterized in that, The second pressure relief seam is composed of multiple spaced-apart sections, and the second pressure relief port is formed at the ends of the sections.
6. The diaphragm for a MEMS microphone according to claim 1, characterized in that, It also includes a third pressure relief seam, which is provided corresponding to the second pressure relief port. The end of the third pressure relief seam forms a third pressure relief port, and the line connecting the two third pressure relief ports intersects with the second pressure relief seam or the second pressure relief port.
7. The diaphragm for a MEMS microphone according to claim 6, characterized in that, The first pressure relief port, the second pressure relief port, and the third pressure relief port are all circular ports.
8. The diaphragm for a MEMS microphone according to claim 1, characterized in that, The pressure relief section is provided in multiple parts, and the multiple pressure relief sections are evenly spaced around the axis of the diaphragm body.
9. The diaphragm for a MEMS microphone according to claim 1, characterized in that, The pressure relief section is located near the edge of the diaphragm body.
10. A MEMS microphone, characterized in that, Includes the diaphragm according to any one of claims 1-9.