MEMS speaker and electronic device
By optimizing the diaphragm position and effective length in the MEMS loudspeaker, the problem of diaphragm damage under impact was solved, improving the loudspeaker's impact resistance and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU LEYI INVESTMENT CO LTD
- Filing Date
- 2025-01-03
- Publication Date
- 2026-07-03
AI Technical Summary
When MEMS loudspeakers are subjected to impact, the diaphragm located on the substrate is easily damaged, leading to performance failure.
By optimizing the positional distribution and effective length of the diaphragm on the substrate, especially by making the diaphragm near the edge of the substrate have a shorter effective length, the risk of impact damage can be reduced.
This improves the shock resistance and overall reliability of MEMS loudspeakers, and reduces the possibility of diaphragm damage in the edge areas.
Smart Images
Figure CN122340418A_ABST
Abstract
Description
Technical Field
[0001] Embodiments of this disclosure relate to the semiconductor field, and more particularly to a MEMS loudspeaker and an electronic device. Background Technology
[0002] Micro-electro-mechanical systems (MEMS) are electromechanical systems with internal structures at the micrometer or even nanometer scale. MEMS are characterized by their small size, light weight, low power consumption, high reliability, high sensitivity, and ease of integration.
[0003] MEMS loudspeakers are miniature transducers that convert electrical signals into sound signals. Their core components (such as actuators / drivers, diaphragms, thermoacoustic diaphragms, etc.) are manufactured on semiconductor materials using MEMS technology. MEMS loudspeakers can be classified into piezoelectric, electrodynamic, electrostatic, and thermoacoustic types according to their working principle.
[0004] MEMS loudspeakers typically consist of multiple diaphragms arranged in an array on a substrate. In practical use, when a MEMS loudspeaker is subjected to impacts such as falling from a height, the diaphragms on the substrate are easily damaged, leading to the failure of the MEMS loudspeaker's performance. Summary of the Invention
[0005] In response to at least one aspect of the above-mentioned problems, this disclosure proposes the following technical solution.
[0006] According to one aspect of the embodiments of this disclosure, a MEMS loudspeaker is provided, including a substrate and at least two diaphragms disposed on the substrate. In a first direction, one end of the diaphragm is supported, and the other end of the diaphragm is unsupported and becomes a free end. The maximum distance between the edge of the supported region of the diaphragm near the free end and the end face of the free end is the effective length of the diaphragm. The at least two diaphragms include a first diaphragm and a second diaphragm. In a top view of the MEMS loudspeaker, in the first direction or a second direction perpendicular to the first direction, the second diaphragm is closer to the same edge of the substrate than the first diaphragm. The effective length of the second diaphragm is less than the effective length of the first diaphragm.
[0007] According to another aspect of the embodiments of this disclosure, an electronic device is proposed that includes the aforementioned MEMS speaker. Attached Figure Description
[0008] The following description and accompanying drawings will better aid in understanding these and other features and advantages of the various embodiments disclosed herein, wherein the same reference numerals in the drawings consistently denote the same parts, wherein:
[0009] Figure 1A and Figure 1B This is a diagram showing the results of an impact damage test on a MEMS loudspeaker.
[0010] Figure 2 This is a top view schematic diagram of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the positions of the individual diaphragms differ in the X direction;
[0011] Figure 3 for Figure 2 A schematic diagram of the cross-section obtained by cutting a MEMS loudspeaker along the X-axis;
[0012] Figure 4 This is a top view schematic diagram of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the positions of the individual diaphragms differ in the Y direction;
[0013] Figure 5 This is a top view schematic diagram of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the positions of the individual diaphragms differ in the X and Y directions;
[0014] Figure 6 This is a top view of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the free ends of two diaphragms are brought close to each other to form a diaphragm pair, a plurality of diaphragm pairs are arranged along the Y direction to form a diaphragm column, and a plurality of diaphragm columns are arranged along the X direction to form a diaphragm array;
[0015] Figure 7 for Figure 6 A schematic diagram of the cross-section obtained by cutting a MEMS loudspeaker along the X-axis;
[0016] Figure 8 for Figure 6 A schematic diagram of the cross-section of the MEMS loudspeaker obtained by cutting along Y1-Y1′;
[0017] Figure 9 for Figure 6 The deformation of the MEMS speaker in Figure 9 At each corner of the diaphragm array, a corresponding diaphragm is removed;
[0018] Figure 10 for Figure 6 The deformation of the MEMS speaker in Figure 10 At each corner of the diaphragm array, the corresponding two diaphragms (a diaphragm pair) are removed;
[0019] Figure 11 for Figure 6 The deformation of the MEMS loudspeaker in the model, for each diaphragm column in C2, C3, C2′ and C3′, shows that the effective length of the diaphragm gradually decreases from the center to the outside in the Y direction;
[0020] Figure 12 for Figure 11 The deformation of the MEMS speaker in Figure 11 On this basis, Figure 12 In the middle diaphragm column C1, the effective length of the diaphragm gradually decreases from the center to the outside in the Y direction. Detailed Implementation
[0021] The technical solutions of this disclosure will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of this disclosure with reference to the accompanying drawings is intended to explain the overall inventive concept of this disclosure and should not be construed as a limitation of this disclosure. These are only some embodiments of the invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in this disclosure are within the scope of protection of this disclosure.
[0022] In this disclosure, the MEMS loudspeaker can achieve energy conversion based on the piezoelectric effect.
[0023] In this disclosure, a top view can refer to a view obtained by observing the surface of the substrate on which the diaphragm is disposed from the thickness direction of the substrate or the piezoelectric resonator.
[0024] In the embodiments of this disclosure, the center of the substrate (or diaphragm) is the geometric center of the substrate (or diaphragm) in a top view. For example, for a rectangular substrate, the center of the substrate is the intersection of the two diagonals of the rectangle.
[0025] In the embodiments of this disclosure, the distance from the diaphragm to the center or edge of the substrate can refer to the distance from a reference portion of the diaphragm to the center or edge of the substrate. This reference portion is, for example, the center of the diaphragm, or an edge of the diaphragm's support region near the center or edge of the substrate, or an edge of the diaphragm near the center or edge of the substrate. When determining the distance from the diaphragm to the right edge of the substrate, the distance from the right edge of the diaphragm to the right edge of the substrate can be used. When comparing the distances of different diaphragms to the center or edge of the substrate, the same reference portion should be used.
[0026] In the embodiments of this disclosure, "the second diaphragm is closer to the same edge of the substrate than the first diaphragm" means that, for a specific substrate edge, the distance from the second diaphragm to that edge is less than the distance from the first diaphragm to that edge. The distance from the diaphragm to the specific substrate edge can be the distance from the edge closest to that substrate edge in the support region of the diaphragm to that substrate edge. Figure 2For example, the distance from diaphragm F1 to the right edge of the substrate is the distance from its supporting edge A1B1 to the right edge of the substrate, and the distance from diaphragm F2 to the right edge of the substrate is the distance from its supporting edge A2B2 to the right edge of the substrate.
[0027] To address the impact resistance issue of MEMS loudspeakers, the inventors of this disclosure conducted impact damage tests on MEMS loudspeakers. Figure 1A and Figure 1B This is a diagram showing the results of an impact damage test on a MEMS loudspeaker. (See also...) Figure 1A and Figure 1B The image shows a top view of a MEMS loudspeaker (hereinafter referred to as a "chip"). Each light-colored rectangle corresponds to a diaphragm, and multiple diaphragms are arranged in a rectangular array on a substrate (the dark area within the white rectangular frame in the image represents the substrate). In the experiment, the sample chip was dropped from a height of approximately 1.2 meters to the ground, and the integrity of its diaphragm array was observed. Figure 1A and Figure 1B The diaphragms near the four vertices of the rectangular array of the sample showed partial or complete breakage (marked by white rectangular frames in the figure). This is because when a chip falls to the ground, the edges of the chip are often impacted first. The vibration generated by the impact is preferentially transmitted to the diaphragm closer to the edge, and it will be severely damaged, especially when the impacted diaphragm has a long effective length.
[0028] Through analysis and summarization of the results of a large number of destructive tests, the inventors discovered the following patterns: (1) the closer the diaphragm is to the edge of the chip (the farther it is from the center of the chip), the easier it is to be damaged; (2) the longer the effective length of the diaphragm, the easier it is to be damaged.
[0029] Based on the above, this disclosure improves the shock resistance of the diaphragm and the overall reliability of the MEMS speaker by optimizing the position distribution and effective length of the diaphragm on the chip substrate surface.
[0030] Figure 2 This is a top view schematic diagram of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the positions of the individual diaphragms differ in the X direction.
[0031] like Figure 2 As shown, the MEMS loudspeaker includes a substrate S1 and multiple diaphragms F1, F2, and F2' located on the substrate. In a first direction (e.g., the X direction in the figure), one end of each diaphragm is supported, while the other end is unsupported and becomes a free end. For example, in Figure 2 In the X direction, the left end of diaphragm F1 is supported, and the right end is free. The left end of diaphragm F2 is supported, and the right end is free. The right end of diaphragm F2′ is supported, and the left end is free.
[0032] Figure 3 for Figure 2 A schematic diagram of the cross-section obtained by cutting a MEMS loudspeaker along the X-axis. From Figure 3 The support of each diaphragm can be clearly seen in the image. For example... Figure 3 As shown, substrate S1 has multiple cavities S11, S12, and S12′. Diaphragm F1 is located above cavity S11, with its left end supported by substrate S1 and its right end free. The unsupported portion of diaphragm F1 extends from point A1B1 on the left side to the right side. The length W1 in the X direction between point A1B1 on the left side and the right end of diaphragm F1 is the effective length of diaphragm F1. Similarly, diaphragm F2 has its left end supported by substrate S1 and its right end free. The length W2 between point A2B2 on the left side and the right end of diaphragm F2 is the effective length of diaphragm F2. Diaphragm F2′ has its right end supported by substrate S1 and its left end free. The length W2′ between point A2′B2′ on the right side and the left end of diaphragm F2′ is the effective length of diaphragm F2′.
[0033] In embodiments of this disclosure, such as Figure 2 As shown in the top view, the distances from diaphragm F1 and diaphragm F2 to the right edge of substrate S1 differ, as do their distances to the center of substrate S1; correspondingly, the effective lengths of diaphragm F1 and diaphragm F2 differ. Similarly, the distances from diaphragm F1 and diaphragm F2′ to the left edge of substrate S1 differ, as do their distances to the center of substrate S1; correspondingly, the effective lengths of diaphragm F1 and diaphragm F2′ differ.
[0034] In optional embodiments, such as Figure 2 As shown, in the X direction, diaphragm F2 is closer to the right edge of substrate S1 than diaphragm F1 (or, the distance from diaphragm F2 to the right edge of substrate S1 is less than the distance from diaphragm F1 to the right edge of substrate S1), and diaphragm F2 is farther from the center of substrate S1 than diaphragm F1. Correspondingly, the effective length W2 of diaphragm F2 is less than the effective length W1 of diaphragm F1. Similarly, in the X direction, diaphragm F2′ is closer to the left edge of substrate S1 than diaphragm F1, and diaphragm F2′ is farther from the center of substrate S1 than diaphragm F1. Correspondingly, the effective length W2′ of diaphragm F2′ is less than the effective length W1 of diaphragm F1.
[0035] In the embodiments of this disclosure, the effective length of different diaphragms may vary. Diaphragms with smaller effective lengths can be placed in positions with a high risk of breakage to improve the diaphragm's impact resistance.
[0036] In the embodiments of this disclosure, the effective length of the diaphragm is set based on the position of the diaphragm on the substrate. For example, the effective length of the diaphragm that is relatively close to the edge of the substrate (away from the center of the substrate) is relatively small, which helps to reduce the risk of failure of the diaphragm after being impacted at the edge of the substrate, and improves the impact resistance of the diaphragm and the overall reliability of the MEMS loudspeaker.
[0037] exist Figure 2 In the illustrated embodiment, the positions of the individual diaphragms differ in the X direction.
[0038] Figure 4 This is a top view of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the positions of the individual diaphragms differ in the Y direction.
[0039] In optional embodiments, such as Figure 4 As shown, in the Y direction, diaphragm F2 is closer to the upper edge of substrate S1 than diaphragm F1, and diaphragm F2 is farther from the center of substrate S1 than diaphragm F1. Correspondingly, the effective length W2 of diaphragm F2 is less than the effective length W1 of diaphragm F1. Similarly, in the Y direction, diaphragm F2′ is closer to the lower edge of substrate S1 than diaphragm F1, and diaphragm F2′ is farther from the center of substrate S1 than diaphragm F1. Correspondingly, the effective length W2′ of diaphragm F2′ is less than the effective length W1 of diaphragm F1.
[0040] Figure 5 This is a top view schematic diagram of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the positions of the individual diaphragms differ in the X and Y directions.
[0041] In optional embodiments, such as Figure 5 As shown, in the X direction, diaphragm F2 is closer to the right edge of substrate S1 than diaphragm F1, and farther from the center of substrate S1 than diaphragm F1. In the Y direction, diaphragm F2 is closer to the upper edge of substrate S1 than diaphragm F1, and farther from the center of substrate S1 than diaphragm F1. Accordingly, the effective length W2 of diaphragm F2 is less than the effective length W1 of diaphragm F1. Similarly, diaphragm F2′ is closer to the left edge of substrate S1 than diaphragm F1, and farther from the center of substrate S1 than diaphragm F1. In the Y direction, diaphragm F2′ is closer to the lower edge of substrate S1 than diaphragm F1, and farther from the center of substrate S1 than diaphragm F1. Accordingly, the effective length W2′ of diaphragm F2′ is less than the effective length W1 of diaphragm F1.
[0042] In an optional embodiment, for adjacent diaphragms F2 and F1, the effective length W2 of diaphragm F2 does not exceed 80% of the effective length W1 of diaphragm F1. Similarly, for adjacent diaphragms F2′ and F1, the effective length W2′ of diaphragm F2′ does not exceed 80% of the effective length W1 of diaphragm F1. Experimental results show that when the effective length of diaphragm F2 does not exceed 80% of the effective length of diaphragm F1, the impact resistance is significantly improved; that is, under the same drop conditions, the probability of the diaphragm falling or being damaged is significantly reduced (compared to when the effective lengths of diaphragm F2 and F1 are the same). Therefore, the above length configuration is beneficial for creating a difference in effective length, which improves the impact resistance of the diaphragm in the edge area while ensuring the diaphragm performance in the central region.
[0043] In optional embodiments, the solutions in this disclosure can be applied to diaphragm arrays. Figure 6 This is a top view of a MEMS loudspeaker according to an exemplary embodiment of the present disclosure, wherein the free ends of two diaphragms are brought close to each other to form a diaphragm pair, a plurality of diaphragm pairs are arranged along the Y direction to form a diaphragm column, and a plurality of diaphragm columns are arranged along the X direction to form a diaphragm array. Figure 7 for Figure 6 A schematic diagram of the cross-section obtained by cutting the MEMS loudspeaker along the X-axis. Figure 8 for Figure 6 A schematic diagram of the cross-section of the MEMS loudspeaker obtained by cutting along Y1-Y1′.
[0044] See Figure 6 and Figure 7 In the diagram, the free ends of the first diaphragm FL81 and the third diaphragm FR81 are close to each other and spaced apart by a certain distance, with equal effective lengths, forming a first diaphragm pair. Similarly, the free ends of the second diaphragm FL82 and the fourth diaphragm FR82 are close to each other and spaced apart by a certain distance, with equal effective lengths, forming a second diaphragm pair.
[0045] See Figure 6 and Figure 8 Multiple first diaphragm pairs (labeled FL11, FL12...FL151, using the markings on the left diaphragm as the pair labels) are arranged along the Y direction, forming the first diaphragm column C1. See also... Figure 8 Adjacent diaphragms in the Y direction are spaced a certain distance apart; for example, the first diaphragm FF11 and the first diaphragm FL21 are spaced a certain distance apart.
[0046] See Figure 6Multiple pairs of second diaphragms (one of which is FL82 and FR82) are arranged along the Y direction to form a second diaphragm column C2. Similarly, there are second diaphragm columns C3, C2′, and C3′.
[0047] See Figure 6 Each diaphragm column C1, C2, C3, C2′, and C3′ is arranged along the X direction to form a diaphragm array. In this diaphragm array, the relationship between the position of the diaphragm on the substrate and the effective length of the diaphragm is... Figures 2-5 Similar to the embodiments described above, for example, diaphragm FL83 is closer to the right edge of substrate S1 (farther from the center of substrate S1) than diaphragm FL81, and correspondingly, the effective length of diaphragm FL83 is less than the effective length of diaphragm FL81. Furthermore, Figure 6 The relationship between the position of the diaphragm pair on the substrate and the effective length of the diaphragm in the diaphragm pair is similar to the relationship between individual diaphragms in different diaphragm pairs. For example, diaphragm pairs FL83 and FL83 are closer to the right edge of substrate S1 (farther from the center of substrate S1) than diaphragm pairs FL81 and FR81. Accordingly, the effective length of the diaphragm in diaphragm pairs FL83 and FL83 is smaller than the effective length of the diaphragm in diaphragm pairs FL81 and FR81.
[0048] In optional embodiments, such as Figure 6 As shown, the diaphragm array is symmetrical about the X-axis and about the Y-axis.
[0049] exist Figure 6 In the illustrated embodiment, the diaphragm columns are aligned in the Y direction, meaning the uppermost diaphragms of each column are at the same horizontal height, and the lowermost diaphragms are at the same horizontal height. In other embodiments, although not shown, the diaphragm columns may be staggered in the Y direction, meaning the uppermost or lowermost diaphragms of each column may have different horizontal heights.
[0050] Figure 9 for Figure 6 The deformation of the MEMS speaker in Figure 9 At each corner of the diaphragm array, a corresponding diaphragm is removed. For example, diaphragms FR13, FR153, FR13′, and FR153′ are removed. In an alternative embodiment, although not shown, only some of the corner diaphragms may be removed; for example, only diaphragm FR13 may be removed, while diaphragms FR153, FR13′, and FR153′ are not removed.
[0051] The removal of the diaphragm can be considered a special case where the effective length of the diaphragm is reduced to 0.
[0052] Figure 10 for Figure 6The deformation of the MEMS speaker in Figure 10 At each corner of the diaphragm array, the corresponding two diaphragms (a diaphragm pair) are removed. For example, diaphragm pairs FL13 and FR13, FL153 and FR153, FL13′ and FR13′, and FL153′ and FR153′ are removed. In an alternative embodiment, although not shown, only some corner diaphragm pairs may be removed; for example, only diaphragm pairs FL13 and FR13 may be removed, while diaphragm pairs FL153 and FR153, FL13′ and FR13′, and FL153 and FR153′ are not removed.
[0053] Figure 11 for Figure 6 The deformation of the MEMS speaker. In an alternative embodiment, such as Figure 11 As shown, for each diaphragm column in C2, C3, C2′, and C3′, the effective length of the diaphragm gradually decreases from the center outwards in the Y direction. This gradual decrease can include cases where the effective length of some diaphragms remains unchanged.
[0054] like Figure 11 As shown, the effective lengths of the diaphragms in the diaphragm rows near the left and right edges of the chip substrate S1 are not entirely the same, and as the diaphragm moves away from the x-axis along the y-direction, the length of the diaphragm pair gradually shortens, forming... Figure 11 The stepped arrangement within. Specifically, with Figure 11 Taking diaphragm columns C1 and C3 as examples, the diaphragms in C1 have a uniform effective length WR61. In C3, the diaphragms FR63 to FR103 (including their symmetrical portions in C1) near the x-axis have a uniform effective length WR63. The diaphragms FR53 to FR13 (including their symmetrical portions in C1) above FR63 have gradually shortening effective lengths WR53 to WR13 along the positive y-direction (diaphragm labels and dimensions are omitted in the figure). The diaphragms FR113 to FR153 (including their symmetrical portions in C1) below FR103 have gradually shortening effective lengths WR113 to WR153 along the positive y-direction (diaphragm labels and dimensions are omitted in the figure). Similarly, the same diaphragm size variation pattern applies to the diaphragms in diaphragm columns C2, C2′, and C3′, although the number of diaphragms with uniform and gradually changing sizes may vary.
[0055] In the above embodiments, the loss of diaphragm area is small, which can avoid a significant reduction in the output sound pressure and power of the speaker.
[0056] In optional embodiments, such as Figure 11As shown, for each of the diaphragm columns C2, C3, C2′, and C3′, the inner edges of each diaphragm pair are aligned in the X direction. For example, for diaphragm column C3, the left edges of each diaphragm pair are aligned.
[0057] In optional embodiments, such as Figure 11 As shown, in diaphragm column C3, the effective diaphragm lengths of diaphragm pairs FL63 and FR63, diaphragm pairs FL103 and FR103, and the diaphragm pairs between them are all the same and equal to the effective diaphragm lengths of the diaphragm pairs in diaphragm column C1.
[0058] Figure 12 for Figure 11 The deformation of the MEMS speaker in Figure 11 On this basis, Figure 12 In the middle diaphragm column C1, the effective length of the diaphragm gradually decreases from the center to the outermost part in the Y direction. Specifically, in Figure 12 In diagram C1, diaphragms FR31 to FR131 (including their symmetrical portions within C1) located near the X-axis have a uniform effective length WR61. Diaphragms FR31 to FR11 (including their symmetrical portions within C1) located above FR31 have gradually shortening effective lengths WR21 to WR11 along the positive y-direction (diaphragm designations and dimensions are omitted in the diagram). Diaphragms FR141 to FR151 (including their symmetrical portions within C1) located below FR131 have gradually shortening effective lengths WR141 to WR151 along the positive y-direction (diaphragm designations and dimensions are omitted in the diagram).
[0059] The above embodiments help to further reduce the possibility of damage to the diaphragm near the substrate edge in the diaphragm array.
[0060] In optional embodiments, such as Figure 11 As shown, for diaphragm column C1, the gaps in each diaphragm pair are aligned in the X direction.
[0061] like Figure 3 , Figure 7 and Figure 8 As shown, the diaphragm is supported by a substrate (surrounding the sidewalls of the cavity). In other embodiments, although not shown, a support portion may be provided on the substrate, which supports the diaphragm.
[0062] In optional embodiments of this disclosure, the diaphragm may employ a sandwich structure consisting of an upper electrode, a piezoelectric layer, and a lower electrode. The number of piezoelectric layers in the diaphragm may be one or multiple.
[0063] In optional embodiments of this disclosure, the piezoelectric layer material includes aluminum nitride, doped aluminum nitride, single-crystal aluminum nitride, lead zirconate titanate (PZT), doped lead zirconate titanate (PZT), single-crystal lead zirconate titanate (PZT), etc.; the electrode material includes molybdenum, platinum, SRO, LNO, etc.
[0064] In embodiments of this disclosure, the first direction and the second direction can be interchanged; for example, the first direction can be the Y direction and the second direction can be the X direction.
[0065] Embodiments of this disclosure also provide an electronic device, including the aforementioned MEMS speaker.
[0066] Based on the above, this disclosure proposes the following technical solution:
[0067] 1. A MEMS loudspeaker, comprising a substrate and at least two diaphragms disposed on the substrate, wherein, in a first direction, one end of the diaphragms is supported and the other end of the diaphragms is unsupported and becomes a free end, and the maximum distance between the edge of the supported region of the diaphragm near the free end and the end face of the free end is the effective length of the diaphragm, wherein:
[0068] The at least two diaphragms include a first diaphragm and a second diaphragm. In a top view of the MEMS loudspeaker, in the first direction or a second direction perpendicular to the first direction, the second diaphragm is closer to the same edge of the substrate than the first diaphragm, and the effective length of the second diaphragm is less than the effective length of the first diaphragm.
[0069] 2. The MEMS loudspeaker according to claim 1, wherein:
[0070] In the first direction, the second diaphragm is closer to the first edge of the substrate than the first diaphragm, and in the second direction, the second diaphragm is closer to the second edge of the substrate than the first diaphragm, and the effective length of the second diaphragm is less than the effective length of the first diaphragm.
[0071] 3. The MEMS loudspeaker according to claim 1, wherein:
[0072] The first diaphragm and the second diaphragm are adjacent in the first direction or the second direction, and the effective length of the second diaphragm does not exceed 80% of the effective length of the first diaphragm.
[0073] 4. The MEMS loudspeaker according to claim 1, wherein:
[0074] The at least two diaphragms also include a third diaphragm and a fourth diaphragm;
[0075] In the first direction, the free ends of the first diaphragm and the free ends of the third diaphragm are close to each other and spaced apart by a certain distance. The effective length of the first diaphragm is equal to the effective length of the third diaphragm. The first diaphragm and the third diaphragm form a first diaphragm pair.
[0076] In the first direction, the free ends of the second diaphragm and the free ends of the fourth diaphragm are close to each other and spaced apart by a certain distance. The effective length of the second diaphragm is equal to the effective length of the fourth diaphragm. The second diaphragm and the fourth diaphragm form a second diaphragm pair.
[0077] 5. The MEMS loudspeaker according to 4, wherein:
[0078] Multiple first diaphragm pairs are arranged along the second direction to form a first diaphragm column, and multiple second diaphragm pairs are arranged along the second direction to form a second diaphragm column;
[0079] At least one first diaphragm column and at least one second diaphragm column are arranged along the first direction to form a diaphragm array.
[0080] 6. The MEMS loudspeaker according to claim 5, wherein:
[0081] In the first direction, from the center of the diaphragm array to the edge of the diaphragm array, the effective length of different diaphragm columns gradually decreases.
[0082] 7. The MEMS loudspeaker according to claim 5, wherein:
[0083] At at least one vertex of the diaphragm array, at least one diaphragm of the corresponding diaphragm pair is removed.
[0084] 8. The MEMS loudspeaker according to claim 5, wherein:
[0085] The diaphragm array is symmetrical about a first axis of symmetry extending in a first direction, and / or the diaphragm array is symmetrical about a second axis of symmetry extending in a second direction.
[0086] 9. The MEMS loudspeaker according to claim 5, wherein:
[0087] For at least one of the second diaphragm columns, in the second direction, from the center of the second diaphragm column to both ends of the second diaphragm column, the effective length of the second diaphragm of the second diaphragm pair gradually decreases.
[0088] 10. The MEMS loudspeaker according to claim 9, wherein:
[0089] For at least one second diaphragm column, the positions of the inner edges of each second diaphragm pair are aligned in the first direction.
[0090] 11. The MEMS loudspeaker according to claim 5, wherein:
[0091] For at least one of the first diaphragm columns, in the second direction, from the center of the first diaphragm column to both ends of the first diaphragm column, the effective length of the first diaphragm of the first diaphragm pair gradually decreases.
[0092] 12. The MEMS loudspeaker according to 11, wherein:
[0093] For at least one second diaphragm column, the gaps between the first diaphragms of each first diaphragm pair are aligned in the first direction.
[0094] 13. The MEMS loudspeaker according to any one of 1-12, wherein:
[0095] The substrate has a cavity, and the diaphragm is supported by sidewalls surrounding the cavity.
[0096] 14. The MEMS loudspeaker according to claim 1, wherein:
[0097] The at least two diaphragms include a fifth diaphragm and a sixth diaphragm. In a top view of the MEMS loudspeaker, in either the first or second direction, the sixth diaphragm is closer to the same edge of the substrate than the fifth diaphragm, and the effective length of the sixth diaphragm is equal to the effective length of the fifth diaphragm.
[0098] 15. An electronic device comprising a piezoelectric transducer according to any one of 1-14.
[0099] Although embodiments of the present disclosure have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A MEMS loudspeaker, comprising a substrate and at least two diaphragms disposed on the substrate, wherein, in a first direction, one end of the diaphragms is supported and the other end of the diaphragms is unsupported and becomes a free end, and the maximum distance between the edge of the supported region of the diaphragm near the free end and the end face of the free end is the effective length of the diaphragm, wherein: The at least two diaphragms include a first diaphragm and a second diaphragm. In a top view of the MEMS loudspeaker, in the first direction or a second direction perpendicular to the first direction, the second diaphragm is closer to the same edge of the substrate than the first diaphragm, and the effective length of the second diaphragm is less than the effective length of the first diaphragm.
2. The MEMS loudspeaker according to claim 1, wherein: In the first direction, the second diaphragm is closer to the first edge of the substrate than the first diaphragm, and in the second direction, the second diaphragm is closer to the second edge of the substrate than the first diaphragm, and the effective length of the second diaphragm is less than the effective length of the first diaphragm.
3. The MEMS loudspeaker according to claim 1, wherein: The first diaphragm and the second diaphragm are adjacent in the first direction or the second direction, and the effective length of the second diaphragm does not exceed 80% of the effective length of the first diaphragm.
4. The MEMS loudspeaker according to claim 1, wherein: The at least two diaphragms also include a third diaphragm and a fourth diaphragm; In the first direction, the free ends of the first diaphragm and the free ends of the third diaphragm are close to each other and spaced apart by a certain distance. The effective length of the first diaphragm is equal to the effective length of the third diaphragm. The first diaphragm and the third diaphragm form a first diaphragm pair. In the first direction, the free ends of the second diaphragm and the free ends of the fourth diaphragm are close to each other and spaced apart by a certain distance. The effective length of the second diaphragm is equal to the effective length of the fourth diaphragm. The second diaphragm and the fourth diaphragm form a second diaphragm pair.
5. The MEMS loudspeaker according to claim 4, wherein: Multiple first diaphragm pairs are arranged along the second direction to form a first diaphragm column, and multiple second diaphragm pairs are arranged along the second direction to form a second diaphragm column; At least one first diaphragm column and at least one second diaphragm column are arranged along the first direction to form a diaphragm array.
6. The MEMS loudspeaker according to claim 5, wherein: In the first direction, from the center of the diaphragm array to the edge of the diaphragm array, the effective length of different diaphragm columns gradually decreases.
7. The MEMS loudspeaker according to claim 5, wherein: At at least one vertex of the diaphragm array, at least one diaphragm of the corresponding diaphragm pair is removed.
8. The MEMS loudspeaker according to claim 5, wherein: The diaphragm array is symmetrical about a first axis of symmetry extending in a first direction, and / or the diaphragm array is symmetrical about a second axis of symmetry extending in a second direction.
9. The MEMS loudspeaker according to claim 5, wherein: For at least one of the second diaphragm columns, in the second direction, from the center of the second diaphragm column to both ends of the second diaphragm column, the effective length of the second diaphragm of the second diaphragm pair gradually decreases.
10. The MEMS loudspeaker according to claim 9, wherein: For at least one second diaphragm column, the positions of the inner edges of each second diaphragm pair are aligned in the first direction.
11. The MEMS loudspeaker according to claim 5, wherein: For at least one of the first diaphragm columns, in the second direction, from the center of the first diaphragm column to both ends of the first diaphragm column, the effective length of the first diaphragm of the first diaphragm pair gradually decreases.
12. The MEMS loudspeaker according to claim 11, wherein: For at least one second diaphragm column, the gaps between the first diaphragms of each first diaphragm pair are aligned in the first direction.
13. The MEMS loudspeaker according to any one of claims 1-12, wherein: The substrate has a cavity, and the diaphragm is supported by sidewalls surrounding the cavity.
14. The MEMS loudspeaker according to claim 1, wherein: The at least two diaphragms include a fifth diaphragm and a sixth diaphragm. In a top view of the MEMS loudspeaker, in either the first or second direction, the sixth diaphragm is closer to the same edge of the substrate than the fifth diaphragm, and the effective length of the sixth diaphragm is equal to the effective length of the fifth diaphragm.
15. An electronic device comprising a piezoelectric transducer according to any one of claims 1-14.