Micro-electromechanical structure and electronic device

Abstract

The micro-electro-mechanical structure comprises a substrate, a diaphragm and a back plate, the back plate comprises a first conductive region and a second conductive region, the first conductive region is opposite to the suspension position and is located on the inner side of the support structure, the diaphragm is electrically connected with the second conductive region, and the first conductive region and the second conductive region are insulated and connected, so that the first conductive region and the second conductive region can work independently, thereby the adjustment of the acoustic performance of the micro-electro-mechanical structure can be realized by using the two different regions of the first conductive region and the second conductive region.

Description

Technical Field

[0001] This invention relates to the field of microelectromechanical systems (MEMS) technology, and more specifically, to a microelectromechanical structure and electronic device. Background Technology

[0002] For the acquisition of sound or electrical signals, existing technologies typically employ MEMS microphones and MEMS speakers for direct detection. For example, a capacitive MEMS microphone can be used to convert sound signals to electrical signals, or a capacitive MEMS speaker can be used to convert electrical signals to sound signals, both of which can achieve the corresponding signal sensing.

[0003] However, existing MEMS products are limited by their own structure and the complexity of their molding process, which makes their acoustic performance relatively stable and difficult to adjust according to actual application needs. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a new technical solution for microelectromechanical structures and electronic devices.

[0005] According to one aspect of the present invention, a microelectromechanical structure (MEMS) is provided. The MEMS structure includes:

[0006] A substrate on which an acoustic cavity is formed;

[0007] A diaphragm having a fixed portion and a suspended portion, the fixed portion being fixed on the substrate and the suspended portion being located on the acoustic cavity;

[0008] A back electrode plate is disposed on the substrate, a gap is formed between the back electrode plate and the diaphragm, and a ring-shaped support structure is formed on the back electrode plate, the support structure extending toward the diaphragm and corresponding to the position of the suspended portion;

[0009] The back electrode plate includes a first conductive region and a second conductive region. The first conductive region is opposite to the suspended part and located inside the support structure. The diaphragm is electrically connected to the second conductive region, and the first conductive region and the second conductive region are insulated from each other.

[0010] When the back electrode plate and / or the diaphragm are energized, the suspended portion is configured to abut against the support structure.

[0011] Optionally, when a first bias voltage is applied between the diaphragm and the first conductive region, the potential of the diaphragm is equal to the potential of the second conductive region.

[0012] Optionally, when a first bias voltage is applied between the diaphragm and the first conductive region, a second bias voltage is applied between the diaphragm and the second conductive region.

[0013] Optionally, the back electrode plate further has a first insulating structure, which divides the back electrode plate into a first conductive region and a second conductive region, and the support structure is electrically connected to the second conductive region.

[0014] Optionally, the back electrode plate also has a second insulating structure located within the second conductive area. The second insulating structure divides the second conductive area into a third conductive area and a fourth conductive area. The third conductive area and the fourth conductive area are insulated from each other, and the support structure is electrically connected to the third conductive area.

[0015] Optionally, both the second insulating structure and the first insulating structure are ring-shaped, and the second insulating structure and the first insulating structure are coaxially arranged.

[0016] Optionally, when a first bias voltage is applied between the diaphragm and the first conductive region, a second bias voltage is applied between the diaphragm and the third conductive region, and a third bias voltage is applied between the diaphragm and the fourth conductive region.

[0017] Optionally, the width of the second insulating structure is the same as the width of the first insulating structure, and the back electrode plate includes a conductive layer and an insulating layer stacked together, wherein the width of the first insulating structure is greater than or equal to the height of the insulating layer.

[0018] Optionally, the distance between the second insulating structure and the supporting structure is greater than or equal to the height of the insulating layer.

[0019] Optionally, the back electrode plate includes a conductive layer and an insulating layer stacked together, and the conductive layer is electrically connected to the support structure;

[0020] The insulating layer is located on the side of the conductive layer closer to the diaphragm, or the insulating layer is located on the side of the conductive layer away from the diaphragm.

[0021] Optionally, the back electrode plate includes a conductive layer, a first insulating layer and a second insulating layer stacked together, the conductive layer being located between the first insulating layer and the second insulating layer, and the conductive layer being electrically connected to the support structure.

[0022] Optionally, the microelectromechanical structure is a microelectromechanical system microphone or a microelectromechanical system speaker.

[0023] According to another aspect of the present invention, an electronic device is provided. The electronic device includes the aforementioned microelectromechanical structure.

[0024] One technical advantage of this embodiment is that by setting the back electrode plate to include a first conductive region and a second conductive region, the first conductive region being opposite to the suspended portion and located inside the support structure, the diaphragm being electrically connected to the second conductive region, and the first conductive region and the second conductive region being insulated from each other, the first conductive region and the second conductive region can work independently, thereby enabling the adjustment of the acoustic performance of the microelectromechanical structure by utilizing these two different regions.

[0025] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.

[0027] Figure 1 This is a schematic diagram of a microelectromechanical structure according to an embodiment of the present disclosure;

[0028] Figure 2 This is another schematic diagram of a microelectromechanical structure according to an embodiment of the present disclosure;

[0029] Figure 3 This is another schematic diagram of a microelectromechanical structure according to an embodiment of the present disclosure;

[0030] Figure 4 This is yet another schematic diagram of a microelectromechanical structure according to an embodiment of the present disclosure;

[0031] Figure 5 This is a schematic diagram of a double-insulating back electrode plate of a microelectromechanical structure according to an embodiment of the present disclosure;

[0032] Figure 6 This is a schematic diagram of a single-insulating-layer back electrode plate of a microelectromechanical structure according to an embodiment of this disclosure;

[0033] Figure 7 This is a schematic diagram of another single-insulating-layer back electrode plate of a microelectromechanical structure according to an embodiment of this disclosure.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Substrate; 001. Acoustic cavity; 2. Diaphragm; 21. Fixing part; 22. Suspended part; 3. Back electrode plate; 31. Support structure; 32. First conductive region; 33. Second conductive region; 331. Third conductive region; 332. Fourth conductive region; 34. First insulating structure; 35. Second insulating structure; 36. Conductive layer; 37. Insulating layer; 38. First insulating layer; 39. Second insulating layer. Detailed Implementation

[0036] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0037] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0038] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0039] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0041] This invention provides a microelectromechanical structure (MEMS). MEMS structures are fabricated based on Micro-Electro-Mechanical System (MEMS) technology. Simply put, MEMS structures can utilize semiconductor materials to form capacitors and integrate them onto a micro-silicon wafer. Products manufactured using MEMS processes are characterized by small size and high sensitivity. Furthermore, MEMS structures exhibit excellent radio frequency interference (RFI) and electromagnetic interference (EMI) suppression capabilities, and are therefore widely used in electronic devices.

[0042] like Figures 1 to 4 As shown, according to one aspect of the present invention, a microelectromechanical structure is provided, comprising:

[0043] Substrate 1, wherein an acoustic cavity 001 is formed on substrate 1;

[0044] The diaphragm 2 has a fixed part 21 and a suspended part 22. The fixed part 21 is fixed on the substrate 1, and the suspended part 22 is located on the acoustic cavity 001.

[0045] A back electrode plate 3 is disposed on the substrate 1, and a gap is formed between the back electrode plate 3 and the diaphragm 2. A ring-shaped support structure 31 is formed on the back electrode plate 3, and the support structure 31 extends toward the diaphragm 2 and corresponds to the position of the suspended part 22.

[0046] The back electrode plate 3 includes a first conductive region 32 and a second conductive region 33. The first conductive region 32 is opposite to the suspended part 22 and located inside the support structure 31. The diaphragm 2 is electrically connected to the second conductive region 33, and the first conductive region 32 and the second conductive region 33 are insulated from each other.

[0047] When the back electrode plate 3 and / or the diaphragm 2 are energized, the suspended portion 22 is configured to abut against the support structure 31.

[0048] like Figures 1 to 4 As shown, a sound cavity 001 is formed on the substrate 1 to house the structure for sound transmission. The diaphragm 2 can be divided into a fixed part 21 and a suspended part 22 according to its connection with the substrate 1, wherein the fixed part 21 is fixed to the substrate 1, and the suspended part 22 is located on the sound cavity 001. That is, the suspended part 22 is located in the center and can vibrate; the fixed part 21 is located around it and cannot vibrate.

[0049] In one configuration, a portion of the edge region of the diaphragm 2 serves as the fixed portion 21, while other regions of the diaphragm 2 serve as the suspended portion 22. The region of the suspended portion 22 that is away from the fixed portion 21 may rest on the substrate 1 or on the edge of the acoustic cavity 001.

[0050] A back electrode plate 3 is disposed on a substrate 1, and the back electrode plate 3 is disposed opposite to the diaphragm 2. A gap is formed between the back electrode plate 3 and the diaphragm 2, and the back electrode plate 3, the diaphragm 2, and the gap between them together constitute a capacitor.

[0051] like Figures 1 to 4 As shown, a ring-shaped support structure 31 is formed on the back electrode plate 3. The support structure 31 can be a protrusion formed on the back electrode plate 3. The support structure 31 extends toward the diaphragm 2 and corresponds to the position of the suspended portion 22.

[0052] The support structure 31 is not located around the suspended portion 22; viewed from the projection direction, it is distributed within the internal region of the suspended portion 22. The support structure 31 divides the suspended portion 22 into an inner suspended region and an outer suspended region. Since the support structure 31 is arranged in a ring shape, the suspended portion 22 surrounded by the support structure 31 along the radial direction of the diaphragm 2 is the inner suspended region, and the suspended portion 22 outside the support structure 31 is the outer suspended region. Under the simple support of the support structure 31, the inner and outer suspended regions can respectively produce vibrational responses to sound and air vibrations.

[0053] Taking this microelectromechanical structure as an example of a microelectromechanical system microphone, when sound pressure is applied to the diaphragm 2, the diaphragm 2 will vibrate accordingly, thereby changing the capacitance between the diaphragm 2 and the back electrode plate 3. The gap between the back electrode plate 3 and the diaphragm 2 can be an air gap or a gap made of other media.

[0054] Based on this, such as Figures 1 to 4 As shown, the back electrode plate 3 in this embodiment of the invention may include a first conductive region 32 and a second conductive region 33, that is, the back electrode plate 3 is divided into sections, and the first conductive region 32 and the second conductive region 33 together form the conductive structure of the back electrode plate 3. The first conductive region 32 is positioned opposite to the suspended portion 22 and is located inside the support structure 31, that is, the first conductive region 32 is located inside, while the second conductive region 33 is located outside, thereby achieving the sectioning of the conductive structure of the back electrode plate 3.

[0055] Furthermore, an insulating connection is provided between the first conductive region 32 and the second conductive region 33, so that the first conductive region 32 and the second conductive region 33 can work independently, thereby enabling the adjustment of the acoustic performance of the microelectromechanical structure by utilizing these two different regions, the first conductive region 32 and the second conductive region 33.

[0056] Specifically, when the back electrode plate 3 and / or the diaphragm 2 are energized—for example, when at least one of the back electrode plate 3 and the diaphragm 2 is biased, or when both the back electrode plate 3 and the diaphragm 2 are subjected to potential—the suspended portion 22 can be pushed towards the back electrode plate 3 under the action of electromagnetic force, thereby forming an abutment relationship with the support structure 31, and the support structure 31 provides support for the diaphragm 2. Simultaneously, by providing an electrical connection between the diaphragm 2 and the second conductive region 33, the influence of parasitic capacitance between the protruding support structure 31 and the diaphragm 2 can be reduced, thereby improving the operational reliability of the microelectromechanical structure (MEMS). Furthermore, the acoustic performance and reliability of the MEMS can be adjusted through the electrical connection between the diaphragm 2 and the second conductive region 33.

[0057] Optionally, the support structure 31 is a continuous ring structure; or, the support structure 31 includes multiple protrusions spaced apart. In this embodiment, the support structure 31 can be a continuous structure or a discontinuous structure. The continuous structure can be circular, rectangular, or other ring-shaped structures, while the discontinuous structure can be multiple protrusions spaced apart. Depending on the actual design or production needs, the multiple protrusions can be evenly distributed or non-uniformly distributed. Utilizing the supporting effect of the support structure 31, the hardness of the inner and outer suspended areas can be significantly improved, thereby increasing the resonant frequency. Using a continuous ring structure as the support structure 31 can more significantly improve the hardness of the suspended area, especially the resonant frequency of the inner suspended area. Using multiple discontinuous protrusions to form the support structure 31 can better improve the overall vibration consistency of the suspended part 22. Moreover, when the suspended part 22 is impacted by a strong airflow, this support structure 31 can, to some extent, assist the suspended part 22 in releasing air pressure, reducing the risk of diaphragm 2 damage.

[0058] Optionally, when a first bias voltage is applied between the diaphragm 2 and the first conductive region 32, the potential of the diaphragm 2 is equal to the potential of the second conductive region 33.

[0059] like Figure 2 As shown, in this embodiment of the invention, when a first bias voltage is applied between the diaphragm 2 and the first conductive region 32 to energize them, the potential of the diaphragm 2 is equal to the potential of the second conductive region 33. For example, the diaphragm 2 and the second conductive region 33 can be connected by gold wire or other conductive materials to make the potential of the diaphragm 2 equal to the potential of the second conductive region 33. This reduces the influence of parasitic capacitance between the support structure 31 and the diaphragm 2, thereby improving the operational reliability of the microelectromechanical structure.

[0060] Optionally, when a first bias voltage is applied between the diaphragm 2 and the first conductive region 32, a second bias voltage is applied between the diaphragm 2 and the second conductive region 33.

[0061] like Figure 3 As shown, in this embodiment of the invention, when a first bias voltage is applied between the diaphragm 2 and the first conductive region 32 to energize them, a second bias voltage is applied between the diaphragm 2 and the second conductive region 33. For example, the diaphragm 2 and the second conductive region 33 can be led out respectively by gold wire or other conductive materials, and a second bias voltage can be applied between their leads. This can also reduce the influence of parasitic capacitance between the support structure 31 and the diaphragm 2, thereby improving the working reliability of the microelectromechanical structure. At the same time, the acoustic performance and reliability of the microelectromechanical structure can be adjusted through the electrical connection between the diaphragm 2 and the second conductive region 33.

[0062] The electric field strength between the diaphragm 2 and the back electrode plate 3 or the vibration capability of the diaphragm 2 can be adjusted by adjusting the magnitude and direction of the second bias voltage, thereby adjusting the acoustic performance and reliability of the microelectromechanical structure.

[0063] Optionally, the back electrode plate 3 also has a first insulating structure 34, which divides the back electrode plate 3 into a first conductive region 32 and a second conductive region 33, and the support structure 31 is electrically connected to the second conductive region 33.

[0064] like Figures 1 to 3 As shown, in this embodiment of the invention, the back electrode plate 3 is further provided with a first insulating structure 34. The first insulating structure 34 can divide the back electrode plate 3 into a first conductive region 32 and a second conductive region 33, and make the first conductive region 32 and the second conductive region 33 insulated from each other, so as to facilitate the adjustment of the acoustic performance of the microelectromechanical structure by using the first conductive region 32 and the second conductive region 33.

[0065] The first insulating structure 34 can be an insulating ring, which facilitates the formation of the first conductive region 32 and the second conductive region 33 on the back electrode plate 3 using the ring structure of the insulating ring. The electrical connection between the support structure 31 and the second conductive region 33 reduces the influence of parasitic capacitance between the support structure 31 and the diaphragm 2, thereby improving the operational reliability of the microelectromechanical structure.

[0066] Optionally, the back electrode plate 3 also has a second insulating structure 35, which is located within the second conductive region 33. The second insulating structure 35 divides the second conductive region 33 into a third conductive region 331 and a fourth conductive region 332. The third conductive region 331 and the fourth conductive region 332 are insulated from each other, and the support structure 31 is electrically connected to the third conductive region 331.

[0067] like Figure 4 As shown, in this embodiment of the invention, the back electrode plate 3 also has a second insulating structure 35, which is located within the second conductive region 33. The second insulating structure 35 divides the second conductive region 33 into a third conductive region 331 and a fourth conductive region 332, and provides an insulating connection between the third conductive region 331 and the fourth conductive region 332. This facilitates the adjustment of the acoustic performance of the microelectromechanical system (MEMS) using the third conductive region 331 and the fourth conductive region 332. For example, a bias voltage can be applied between the third conductive region 331 and the diaphragm 2, or between the fourth conductive region 332 and the diaphragm 2, thereby achieving the adjustment of the acoustic performance of the MEMS.

[0068] The second insulating structure 35 can be an insulating ring, which facilitates the formation of the third conductive region 331 and the fourth conductive region 332 within the second conductive region 33 using the ring-shaped structure of the insulating ring. The electrical connection between the support structure 31 and the third conductive region 331 reduces the impact of parasitic capacitance between the support structure 31 and the diaphragm 2, thereby improving the operational reliability of the microelectromechanical structure.

[0069] Optionally, both the second insulating structure 35 and the first insulating structure 34 are annular structures, and the second insulating structure 35 and the first insulating structure 34 are coaxially arranged.

[0070] like Figure 4 As shown, in this embodiment of the invention, both the second insulating structure 35 and the first insulating structure 34 are ring-shaped, meaning they are both insulating rings and are coaxially arranged. Specifically, the first insulating structure 34 and the second insulating structure 35 are sequentially arranged from the center to the periphery of the back electrode plate 3, allowing the conductive structure of the back electrode plate 3 to be conveniently divided into a first conductive region 32, a third conductive region 331, and a fourth conductive region 332. This reduces the influence of parasitic capacitance between the protruding support structure 31 and the diaphragm 2, improving the operational reliability of the microelectromechanical system (MEMS). Furthermore, the acoustic performance and reliability of the MEMS can be adjusted using the electrical connections between the diaphragm 2 and different conductive regions.

[0071] Optionally, when a first bias voltage is applied between the diaphragm 2 and the first conductive region 32, a second bias voltage is applied between the diaphragm 2 and the third conductive region 331, and a third bias voltage is applied between the diaphragm 2 and the fourth conductive region 332.

[0072] like Figure 4 As shown, in this embodiment of the invention, when a first bias voltage is applied between the diaphragm 2 and the first conductive region 32 to energize them, a second bias voltage is applied between the diaphragm 2 and the third conductive region 331. For example, the diaphragm 2 and the third conductive region 331 can be led out separately using gold wire or other conductive materials, and a second bias voltage is applied between their leads. Similarly, a third bias voltage is applied between the diaphragm 2 and the fourth conductive region 332. Again, the diaphragm 2 and the fourth conductive region 332 can be led out separately using gold wire or other conductive materials, and a third bias voltage is applied between their leads. This can also reduce the influence of parasitic capacitance between the support structure 31 and the diaphragm 2, and can also utilize the electrical connections between the diaphragm 2 and the third conductive region 331 and between the diaphragm 2 and the fourth conductive region 332 to adjust the acoustic performance and reliability of the microelectromechanical structure.

[0073] The electric field strength between the diaphragm 2 and the back electrode plate 3 or the vibration capability of the diaphragm 2 can be adjusted by adjusting the magnitude and direction of the second bias voltage and / or the third bias voltage, thereby achieving the adjustment of the acoustic performance and reliability of the microelectromechanical structure.

[0074] Optionally, the width of the second insulating structure 35 is the same as the width of the first insulating structure 34, and the back electrode plate 3 includes a conductive layer 36 and an insulating layer 37 stacked together, wherein the width of the first insulating structure 34 is greater than or equal to the height of the insulating layer 37.

[0075] Specifically, in this embodiment of the invention, the width of the second insulating structure 35 is the same as the width of the first insulating structure 34, that is, the widths of the two insulating rings are the same, so as to improve the symmetry of the insulation effect of the second insulating structure 35 and the first insulating structure 34, and also to facilitate the arrangement of the second insulating structure 35 and the first insulating structure 34.

[0076] Furthermore, the back electrode plate 3 includes a conductive layer 36 and an insulating layer 37 stacked together. Multiple solder joints can be arranged on the conductive layer 36, thereby enabling electrical connections to be achieved using different areas on the back electrode plate 3. Setting the width of the first insulating structure 34 to be greater than or equal to the height of the insulating layer 37 ensures the insulation effect of the first insulating structure 34, improves the reliability of the insulating connection between the first conductive region 32 and the second conductive region 33, and facilitates the adjustment of the acoustic performance of the microelectromechanical structure using the first conductive region 32 and the second conductive region 33.

[0077] Optionally, the distance between the second insulating structure 35 and the supporting structure 31 is greater than or equal to the height of the insulating layer 37.

[0078] Specifically, in this embodiment of the invention, the distance between the second insulating structure 35 and the supporting structure 31 is greater than or equal to the height of the insulating layer 37, which can ensure the insulation effect of the second insulating structure 35 and improve the reliability of the insulating connection between the third conductive region 331 and the fourth conductive region 332, thereby facilitating the adjustment of the acoustic performance of the microelectromechanical structure using the third conductive region 331 and the fourth conductive region 332.

[0079] In addition, the distance between the first insulating structure 34 and the support structure 31 can also be set to be greater than or equal to the height of the insulating layer 37. That is, the first insulating structure 34 and the support structure 31, as well as the second insulating structure 35 and the support structure 31, should maintain at least a certain distance, so as to ensure the working area of ​​the third conductive area 331 and facilitate the setting of solder joints on the third conductive area 331.

[0080] Optionally, the back electrode plate 3 includes a conductive layer 36 and an insulating layer 37 stacked together, and the conductive layer 36 is electrically connected to the support structure 31;

[0081] The insulating layer 37 is located on the side of the conductive layer 36 closer to the diaphragm 2, or the insulating layer 37 is located on the side of the conductive layer 36 away from the diaphragm 2.

[0082] like Figure 6 and Figure 7 As shown, the back electrode plate 3 in this embodiment of the invention may include a conductive layer 36 and an insulating layer 37 stacked together. Multiple solder joints may be arranged on the conductive layer 36, thereby enabling electrical connection using different areas on the back electrode plate 3. The insulating layer 37 can improve the safety of the electrical connection of the back electrode plate 3.

[0083] Based on the specific design of the actual microelectromechanical structure, such as Figure 7 As shown, the insulating layer 37 can be located on the side of the conductive layer 36 closer to the diaphragm 2; as Figure 6 As shown, the insulating layer 37 can also be located on the side of the conductive layer 36 away from the diaphragm 2, both of which can improve the safety of the electrical connection of the back electrode plate 3.

[0084] Optionally, the back electrode plate 3 includes a conductive layer 36, a first insulating layer 38, and a second insulating layer 39 stacked together. The conductive layer 36 is located between the first insulating layer 38 and the second insulating layer 39, and the conductive layer 36 is electrically connected to the support structure 31.

[0085] like Figure 5 As shown, the back electrode plate 3 of this embodiment may include a conductive layer 36, a first insulating layer 38, and a second insulating layer 39 stacked together. The conductive layer 36 is located between the first insulating layer 38 and the second insulating layer 39, that is, the first insulating layer 38 and the second insulating layer 39 are located on both sides, while the conductive layer 36 is sandwiched between the first insulating layer 38 and the second insulating layer 39. This ensures the electrical connection of the conductive layer 36 while providing good protection for the conductive layer 36 using the first insulating layer 38 and the second insulating layer 39 on both sides, thereby improving the working stability and safety of the back electrode plate 3.

[0086] Specifically, the conductive layer 36 is electrically connected to the support structure 31, that is, the conductive layer 36 is electrically connected to the conductive part of the support structure 31. This allows the conductive part of the support structure 31 to be brought out, making it easier to apply a bias voltage to reduce the influence of parasitic capacitance between the relatively close support structure 31 and the diaphragm 2, thereby improving the operational reliability of the microelectromechanical structure.

[0087] Optionally, in this embodiment of the invention, the microelectromechanical structure can be a microelectromechanical system microphone or a microelectromechanical system speaker. When the microelectromechanical structure is a microelectromechanical system microphone, it can convert sound signals into electrical signals; when the microelectromechanical structure is a microelectromechanical system speaker, it can convert electrical signals into sound signals; when the microelectromechanical structure is a microelectromechanical system pressure sensor, it can convert pressure signals into electrical signals.

[0088] According to another aspect of the present invention, an electronic device is provided. This electronic device includes the aforementioned microelectromechanical system (MEMS), which is configured to enable the conversion between sound signals and electrical signals during operation.

[0089] In this embodiment, when the electronic device is working, its internal microphone unit can receive the input sound signal and convert the sound signal into an electrical signal; or, its internal speaker unit can receive the input electrical signal and convert the electrical signal into a sound signal. The electronic device can be a mobile phone, television, computer, smartwatch, etc.

[0090] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0091] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A microelectromechanical structure, characterized in that, include: A substrate (1) on which an acoustic cavity (001) is formed; A diaphragm (2) having a fixed part (21) and a suspended part (22), the fixed part (21) being fixed on the substrate (1), and the suspended part (22) being located on the acoustic cavity (001); A back electrode plate (3) is disposed on the substrate (1). A gap is formed between the back electrode plate (3) and the diaphragm (2). A ring-shaped support structure (31) is formed on the back electrode plate (3). The support structure (31) extends toward the diaphragm (2) and corresponds to the position of the suspended part (22). The back electrode plate (3) includes a first conductive region (32) and a second conductive region (33). The first conductive region (32) is opposite to the suspended part (22) and located inside the support structure (31). The diaphragm (2) is electrically connected to the second conductive region (33), and the first conductive region (32) and the second conductive region (33) are insulated from each other. When the back electrode plate (3) and / or the diaphragm (2) are energized, the suspended portion (22) is configured to abut against the support structure (31).

2. The microelectromechanical structure according to claim 1, characterized in that, When a first bias voltage is applied between the diaphragm (2) and the first conductive region (32), the potential of the diaphragm (2) is equal to the potential of the second conductive region (33).

3. The microelectromechanical structure according to claim 1, characterized in that, When a first bias voltage is applied between the diaphragm (2) and the first conductive region (32), a second bias voltage is applied between the diaphragm (2) and the second conductive region (33).

4. The microelectromechanical structure according to claim 1, characterized in that, The back electrode plate (3) also has a first insulating structure (34), which divides the back electrode plate (3) into a first conductive region (32) and a second conductive region (33), and the support structure (31) is electrically connected to the second conductive region (33).

5. The microelectromechanical structure according to claim 4, characterized in that, The back electrode plate (3) also has a second insulating structure (35), which is located within the second conductive region (33). The second insulating structure (35) divides the second conductive region (33) into a third conductive region (331) and a fourth conductive region (332). The third conductive region (331) and the fourth conductive region (332) are insulated from each other, and the support structure (31) is electrically connected to the third conductive region (331).

6. The microelectromechanical structure according to claim 5, characterized in that, Both the second insulating structure (35) and the first insulating structure (34) are ring-shaped, and the second insulating structure (35) and the first insulating structure (34) are coaxially arranged.

7. The microelectromechanical structure according to claim 5, characterized in that, When a first bias voltage is applied between the diaphragm (2) and the first conductive region (32), a second bias voltage is applied between the diaphragm (2) and the third conductive region (331), and a third bias voltage is applied between the diaphragm (2) and the fourth conductive region (332).

8. The microelectromechanical structure according to claim 6, characterized in that, The width of the second insulating structure (35) is the same as the width of the first insulating structure (34). The back electrode plate (3) includes a conductive layer (36) and an insulating layer (37) stacked together. The width of the first insulating structure (34) is greater than or equal to the height of the insulating layer (37).

9. The microelectromechanical structure according to claim 8, characterized in that, The distance between the second insulating structure (35) and the supporting structure (31) is greater than or equal to the height of the insulating layer (37).

10. The microelectromechanical structure according to claim 1, characterized in that, The back electrode plate (3) includes a conductive layer (36) and an insulating layer (37) stacked together, and the conductive layer (36) is electrically connected to the support structure (31); The insulating layer (37) is located on the side of the conductive layer (36) closer to the diaphragm (2), or the insulating layer (37) is located on the side of the conductive layer (36) away from the diaphragm (2).

11. The microelectromechanical structure according to claim 1, characterized in that, The back electrode plate (3) includes a conductive layer (36), a first insulating layer (38), and a second insulating layer (39) stacked together. The conductive layer (36) is located between the first insulating layer (38) and the second insulating layer (39), and the conductive layer (36) is electrically connected to the support structure (31).

12. The microelectromechanical structure according to claim 1, characterized in that, The microelectromechanical structure is a microelectromechanical system microphone or a microelectromechanical system speaker.

13. An electronic device, characterized in that, Includes the microelectromechanical structure as described in any one of claims 1 to 12.

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