Sound production device and sound production apparatus

Abstract

Disclosed are a sound production device and a sound production apparatus, relating to the technical field of loudspeakers. The sound production device comprises: a base substrate, wherein a blind hole is formed on one side surface of the base substrate, a diaphragm is formed at the hole bottom of the blind hole, and the hole bottom and the hole wall of the blind hole define a cavity structure; and a plurality of driving layers, stacked on one side of the base substrate and arranged close to the diaphragm, wherein the driving layers each comprise a first electrode, a piezoelectric layer and a second electrode that are sequentially stacked, and the first electrode is arranged close to the diaphragm; the orthographic projections of the first electrode, the piezoelectric layer and the second electrode of at least one driving layer on the base substrate overlap with the orthographic projection of the cavity structure on the base substrate, and the orthographic projection of the piezoelectric layer of each driving layer on the base substrate overlaps with the orthographic projection of the cavity structure on the base substrate.

Description

Sound-generating device and sound-generating apparatus Technical Field

[0001] The present disclosure relates to the technical field of loudspeakers, and in particular to a sound-generating device and a sound-generating apparatus. Background Art

[0002] The working principle of piezoelectric MEMS microspeaker is to achieve sound pressure output based on the piezoelectric effect of piezoelectric thin film materials. It has the advantages of simple manufacturing, high signal-to-noise ratio, fast response speed and dust-free.

[0003] Overview

[0004] The present disclosure provides a sound-generating device, comprising:

[0005] A base substrate, wherein a blind hole is provided on one side surface of the base substrate, the bottom of the blind hole constitutes a diaphragm, and the bottom of the blind hole and the hole wall together form a cavity structure; and

[0006] A plurality of driving layers are stacked on one side of the base substrate and disposed close to the diaphragm, the driving layers comprising a first electrode, a piezoelectric layer, and a second electrode stacked in sequence, the first electrode being disposed close to the diaphragm;

[0007] Among them, the orthographic projections of the first electrode, piezoelectric layer and second electrode of at least one of the driving layers on the base substrate have an overlapping area with the orthographic projection of the cavity structure on the base substrate, and the orthographic projections of the piezoelectric layer of each driving layer and the cavity structure on the base substrate all overlap.

[0008] In some embodiments, the plurality of drive layers include a first drive layer and a second drive layer, wherein the first drive layer is located between the diaphragm and the second drive layer;

[0009] The second electrode of the first driving layer is a first driving electrode, the first electrode of the second driving layer is a second driving electrode, the second driving electrode and the first driving electrode are in the same layer and are separated from each other, and the first driving electrode is symmetrically arranged on at least one side of the second driving electrode.

[0010] In some embodiments, the first driving electrode is a closed ring structure surrounding the second driving electrode.

[0011] In some embodiments, the first driving electrode is a non-closed ring structure disposed around the second driving electrode.

[0012] In some embodiments, the first driving electrode includes a plurality of sub-electrodes, and the plurality of sub-electrodes are arranged at equal intervals in a direction surrounding the second driving electrode.

[0013] In some embodiments, the minimum distance between two adjacent sub-electrodes is greater than or equal to 0.1 mm and less than or equal to 0.6 mm; and / or

[0014] The two adjacent sub-electrodes are the first sub-electrode and the second sub-electrode. In the orthographic projection on the substrate, the angle between the side of the first sub-electrode close to the second sub-electrode and the first straight line is greater than or equal to 30° and less than or equal to 90°. The opening of the angle is back to the second sub-electrode, and the first straight line is a straight line connecting the center of the first sub-electrode and the center of the second sub-electrode.

[0015] In some embodiments, the first driving electrode overlaps with an orthographic projection of the cavity structure on the base substrate.

[0016] In some embodiments, the plurality of driving layers include a second driving layer, the second driving layer is a driving layer away from the diaphragm, the piezoelectric layer of the second driving layer is a second piezoelectric layer, and the second electrode of the second driving layer is a third driving electrode; and

[0017] The third driving electrode completely covers the second piezoelectric layer, and the orthographic projections of the third driving electrode and the second piezoelectric layer on the substrate completely overlap; or

[0018] The third driving electrode partially covers the second piezoelectric layer, and the orthographic projection of the third driving electrode on the base substrate is located within the orthographic projection range of the second piezoelectric layer on the base substrate.

[0019] In some embodiments, the third driving electrode is centered relative to the second piezoelectric layer in an orthographic projection on the substrate.

[0020] In some embodiments, in an orthographic projection on the base substrate, a width of the third driving electrode is substantially equal to half a width of the second piezoelectric layer.

[0021] In some embodiments, the first electrode of the second driving layer is a second driving electrode, and the second driving electrode includes a lead area, which is arranged near the edge of the second driving electrode, and the lead area has no overlap with the second piezoelectric layer and the orthographic projection of the third driving electrode on the substrate.

[0022] In some embodiments, the plurality of driving layers include a second driving layer, the piezoelectric layer of the second driving layer includes a first piezoelectric pattern, and an orthographic projection of the first piezoelectric pattern on the base substrate is located within the range of the cavity structure.

[0023] In some embodiments, an orthographic projection center of the first piezoelectric pattern on the base substrate substantially coincides with an orthographic projection center of the cavity structure on the base substrate.

[0024] In some embodiments, the piezoelectric layer of the second driving layer further includes a second piezoelectric pattern, the first piezoelectric pattern and the second piezoelectric pattern are in the same layer and are separated from each other, the second piezoelectric pattern is symmetrically arranged on at least one side of the first piezoelectric pattern, and the second piezoelectric pattern overlaps with the orthographic projection of the cavity structure on the base substrate.

[0025] In some embodiments, the second piezoelectric pattern is a closed ring structure surrounding the first piezoelectric pattern.

[0026] In some embodiments, in a direction from the first piezoelectric pattern to the second piezoelectric pattern, a ratio of a width of the second piezoelectric pattern to a width of the first piezoelectric pattern is greater than or equal to one third and less than or equal to one half.

[0027] In some embodiments, the second driving electrode includes a first electrode pattern and a second electrode pattern in the same layer and separated from each other, the orthographic projection of the first piezoelectric pattern on the base substrate is located within the orthographic projection range of the first electrode pattern on the base substrate, and the orthographic projection of the second piezoelectric pattern on the base substrate is located within the orthographic projection range of the second electrode pattern on the base substrate.

[0028] In some embodiments, the orthographic projection shape of the piezoelectric layer on the substrate is a centrally symmetrical figure, and the center of symmetry is the orthographic projection center of the cavity structure on the substrate.

[0029] In some embodiments, the second electrodes of the plurality of driving layers are connected to a same first lead, and the first electrodes of the plurality of driving layers are connected to a same second lead.

[0030] The present disclosure provides a sound-generating device, comprising: a sound-generating device as described in any embodiment; and a driving circuit connected to the sound-generating device and configured to provide a driving signal to a first electrode and a second electrode in the driving layer.

[0031] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following is a brief introduction to the drawings required for the description of the embodiments or related technologies. Obviously, the drawings described below are some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without inventive efforts. It should be noted that the scales in the drawings are for illustration only and do not represent the actual scale.

[0034] FIG1 exemplarily shows a cross-sectional structural diagram of a sound-generating device in the related art;

[0035] FIG2 exemplarily shows a schematic structural diagram of a first sound-generating device provided by the present disclosure;

[0036] FIG3 exemplarily shows a schematic structural diagram of a second sound-generating device provided by the present disclosure;

[0037] FIG4 exemplarily shows a schematic structural diagram of a third sound-generating device provided by the present disclosure;

[0038] FIG5 exemplarily shows a structural diagram of a fourth sound-generating device provided by the present disclosure;

[0039] FIG6 exemplarily shows a curve showing the relationship between output energy and d3 / d2;

[0040] FIG7 exemplarily shows a comparison curve of sound pressure levels of the sound-generating device shown in FIG1 and the sound-generating device shown in FIG2 ;

[0041] FIG8 exemplarily shows a comparison curve of sound pressure levels of the sound-generating device shown in FIG1 and the sound-generating device shown in FIG5 ;

[0042] FIG9 shows a parameter comparison of PZT material and AlN material.

[0043] Detailed description

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0045] Referring to Figure 1, a schematic diagram of the cross-sectional structure of a sound-emitting device in the related art is shown. Referring to Figure a in Figure 2, a schematic diagram of the cross-sectional structure of a sound-emitting device provided by the present disclosure is exemplarily shown. As shown in Figures a in Figures 1 and 2, the sound-emitting device includes: a substrate 11, a blind hole H is provided on one side surface of the substrate 11 (the lower surface as shown in Figures 1 and 2), the bottom of the blind hole H constitutes a diaphragm 12, and the bottom of the blind hole H and the hole wall together form a cavity structure Q.

[0046] As shown in Figure 2(a), the sound-generating device further includes: a plurality of drive layers 13 stacked on one side of the base substrate 11 and disposed proximate to the diaphragm 12. The drive layers 13 include a first electrode E1, a piezoelectric layer PL, and a second electrode E2 stacked in sequence, with the first electrode E1 disposed proximate to the diaphragm 12. The orthographic projections of the first electrode E1, the piezoelectric layer PL, and the second electrode E2 of at least one drive layer 13 on the base substrate 11 overlap with the orthographic projection of the cavity structure Q on the base substrate 11. The orthographic projections of the piezoelectric layer PL and the cavity structure Q on the base substrate 11 of each drive layer 13 overlap.

[0047] Based on the "inverse piezoelectric effect" of the piezoelectric layer PL, the driving layer 13 can drive the diaphragm 12 to vibrate in a direction perpendicular to the diaphragm 12. The "inverse piezoelectric effect" means that the piezoelectric layer PL undergoes elastic deformation under the drive of the electrical signal on the first electrode E1 and the second electrode E2, thereby converting the electrical signal (electrical energy) into mechanical vibration (acoustic energy).

[0048] As shown in FIG1 , a conventional sound-generating device includes a single driving layer 13 , and the sound pressure level of the sound-generating device is relatively poor.

[0049] The sound-generating device provided by the present disclosure, as shown in Figure a in Figure 2, drives the diaphragm 12 to vibrate in a direction perpendicular to the diaphragm 12 through multiple stacked driving layers 13. The joint driving of multiple driving layers 13 can increase the vibration amplitude of the diaphragm 12, thereby improving the sound pressure level of the sound-generating device.

[0050] In the present disclosure, the piezoelectric layer PL can be an inorganic piezoelectric film such as PZT (lead zirconate titanate piezoelectric ceramic), AlN, ZnO, etc., or an organic piezoelectric film layer such as PVDF (polyvinylidene fluoride), PVDF-TrFE (vinylidene fluoride trifluoroethylene copolymer), PDMS (polydimethylsiloxane), etc.

[0051] Figure 9 shows a comparison of parameters between PZT and AlN materials. Because PZT has a larger piezoelectric constant, using PZT for the piezoelectric layer PL increases the vibration amplitude of the diaphragm 12 and improves the sound pressure level of the sound-generating device. Using AlN for the piezoelectric layer PL also reduces the power consumption of the sound-generating device.

[0052] Exemplarily, the piezoelectric layers PL in different driving layers 13 may be made of the same material. For example, all the piezoelectric layers PL may be made of AlN material or PZT material.

[0053] For example, the piezoelectric layers PL in different driving layers 13 may be made of different materials. For example, some piezoelectric layers PL may be made of AlN material, while others may be made of PZT material. This allows for the combined use of the advantages of both materials, increasing the vibration amplitude of the diaphragm 12 while minimizing power consumption.

[0054] Exemplarily, the materials of the first electrode E1 and the second electrode E2 may be metal materials such as Au, Mo, Ti, Pt, or transparent conductive materials such as ITO.

[0055] Exemplarily, the base substrate 11 may be a silicon substrate or a glass substrate.

[0056] As shown in Figure 2(a), the multiple drive layers 13 include a first drive layer 131 and a second drive layer 132. The first drive layer 131 is located between the diaphragm 12 and the second drive layer 132. Specifically, the first electrode E1 of the first drive layer 131 is the fourth drive electrode E11, the piezoelectric layer PL of the first drive layer 131 is the first piezoelectric layer PL1, the second electrode E2 of the first drive layer 131 is the first drive electrode E21, the first electrode E1 of the second drive layer 132 is the second drive electrode E12, the second piezoelectric layer PL2 is the second piezoelectric layer PL2, and the second electrode E2 of the second drive layer 132 is the third drive electrode E22.

[0057] In some embodiments, as shown in FIG2 a, the second drive electrode E12 and the first drive electrode E21 are arranged in the same layer and separated from each other, and the first drive electrode E21 is symmetrically arranged on at least one side of the second drive electrode E12. As shown in FIG2 b or FIG2 c, the first drive electrode E21 is symmetrically arranged around the second drive electrode E12.

[0058] In FIG2 , FIGa shows a schematic diagram of a cross-sectional structure of a sound-generating device, FIGb shows a schematic diagram of a planar structure of the sound-generating device shown in FIGa, and FIGc shows another schematic diagram of a planar structure of the sound-generating device shown in FIGa.

[0059] As shown in Figure b or Figure c in Figure 2, the first driving electrode E21 is symmetrically arranged on at least one side of the second driving electrode E12. This may mean that the first driving electrode E21 arranged on the periphery of the second driving electrode E12 is centrally symmetrical, and the center of symmetry is, for example, the center of symmetry or the geometric center of the second driving electrode E12. It may also mean that the first driving electrode E21 arranged on the periphery of the second driving electrode E12 is axially symmetrical, and the axis of symmetry is, for example, the axis of symmetry of the second driving electrode E12.

[0060] In this embodiment, since the first driving electrodes E21 are symmetrically arranged around the second driving electrodes E12, this is beneficial to improving the balance of vibration.

[0061] To avoid creepage, as shown in FIG2 b or FIG2 c, the gap width w1 between the second drive electrode E12 and the first drive electrode E21 is, for example, greater than or equal to 0.3 mm and less than or equal to 0.5 mm. Furthermore, the gap width w1 between the second drive electrode E12 and the first drive electrode E21 is substantially the same at different locations.

[0062] In some embodiments, in an orthographic projection on the base substrate 11 , the geometric center of the first driving electrode E21 substantially coincides with the geometric center of the second driving electrode E12 .

[0063] For example, as shown in Figure 2 (b) or (c), the second drive electrode E12 is circular, the first drive electrode E21 is ring-shaped, and the center of the circle roughly coincides with the center of the ring. Of course, the second drive electrode E12 can also be rectangular, the first drive electrode E21 can be rectangular, and the center of the rectangle roughly coincides with the center of the rectangular ring.

[0064] For example, as shown in Figure b or Figure c in Figure 2, the inner contour or outer contour shape (a circle as shown in Figure 2) of the positive projection of the first driving electrode E21 on the base substrate 11 is the same as the outer contour shape (a circle as shown in Figure 2) of the positive projection of the second driving electrode E12 on the base substrate 11.

[0065] In some embodiments, as shown in FIG2 b , the first driving electrode E21 is a closed ring structure surrounding the second driving electrode E12 , which can increase the contact area between the first driving electrode E21 and the first piezoelectric layer PL1 , thereby further increasing the vibration amplitude of the diaphragm 12 .

[0066] In some embodiments, as shown in c in FIG. 2 , the first driving electrode E21 is a non-closed ring structure disposed around the second driving electrode E12 .

[0067] Exemplarily, as shown in c in FIG. 2 , the first driving electrode E21 includes a plurality of sub-electrodes 21 , and the plurality of sub-electrodes 21 are arranged at equal intervals in a direction f1 surrounding the second driving electrode E12 .

[0068] In this example, the provision of multiple sub-electrodes 21 is equivalent to dividing the first drive layer 131 into multiple drive sections, which helps reduce the vibration damping of each drive section. In addition, because the multiple sub-electrodes 21 are evenly spaced in the direction f1 surrounding the second drive electrode E12, this can further improve vibration balance.

[0069] Exemplarily, as shown in c in FIG. 2 , the orthographic projection shapes and sizes of the different sub-electrodes 21 on the base substrate 11 are the same.

[0070] Exemplarily, as shown in c in Figure 2, when the shape of the second driving electrode E12 is circular, the sub-electrode 21 is fan-shaped, and multiple fan-shaped sub-electrodes 21 are arranged at equal intervals along the direction f1 surrounding the second driving electrode E12, forming a non-closed circular first driving electrode E21.

[0071] For example, as shown in c in Figure 2 , the minimum spacing g1 between two adjacent sub-electrodes 21 is greater than or equal to 0.1 mm and less than or equal to 0.6 mm. This can reduce vibration damping while minimizing the impact on the climbing voltage.

[0072] Exemplarily, as shown in c in Figure 2, the two adjacent sub-electrodes 21 are the first sub-electrode 211 and the second sub-electrode 212. In the orthographic projection on the base substrate 11, the angle a between the side S1 of the first sub-electrode 211 close to the second sub-electrode 212 and the first straight line S2 is greater than or equal to 30° and less than or equal to 90°. The opening of the angle a faces away from the second sub-electrode 212, and the first straight line S2 is a straight line connecting the center of the first sub-electrode 211 and the center of the second sub-electrode 212.

[0073] In some embodiments, as shown in Figure a in Figure 2, in the orthographic projection on the base substrate 11, the first piezoelectric layer PL1 covers the entire diaphragm 12, the second piezoelectric layer PL2 partially covers the first piezoelectric layer PL1, and the second piezoelectric layer PL2 is located within the range of the first piezoelectric layer PL1.

[0074] For example, as shown in Figure a in Figure 2, in the orthographic projection on the base substrate 11, the first piezoelectric layer PL1 is a circle with a diameter of d0, the cavity structure Q is a circle with a diameter of d1, and the second piezoelectric layer PL2 is a circle with a diameter of d2, where d0>d1≥d2.

[0075] Furthermore, as shown in FIG. 2 a , in the orthographic projection on the base substrate 11 , the geometric center of the second piezoelectric layer PL2 roughly coincides with the geometric center of the first piezoelectric layer PL1 .

[0076] Exemplarily, as shown in FIG. 2 or FIG. 5 a , the orthographic projections of the first driving electrode E21 and the cavity structure Q on the base substrate 11 do not overlap.

[0077] 3 or 4 , the first driving electrode E21 overlaps with the orthographic projection of the cavity structure Q on the base substrate 11 , which can increase the driving capability of the first driving layer 131 and further increase the vibration amplitude of the diaphragm 12 .

[0078] For example, in FIG. 3 , a portion of the first driving electrode E21 close to the second driving electrode E12 overlaps with the orthographic projection of the cavity structure Q on the base substrate 11 .

[0079] For example, in FIG. 4 , the orthographic projection of the first driving electrode E21 on the base substrate 11 is located within the orthographic projection range of the cavity structure Q on the base substrate 11 .

[0080] In some embodiments, as shown in FIG. 2 a , FIG. 3 , and FIG. 4 , the plurality of driving layers 13 include a second driving layer 132 , and the second driving layer 132 is the driving layer 13 away from the diaphragm 12 .

[0081] For example, as shown in FIG. 2 a, the third drive electrode E22 completely covers the second piezoelectric layer PL2, and the orthographic projections of the third drive electrode E22 and the second piezoelectric layer PL2 on the base substrate 11 completely overlap. For example, in the orthographic projection on the base substrate 11, the second piezoelectric layer PL2 is a circle with a diameter d2, and the third drive electrode E22 is a circle with a diameter d3. In this example, d3:d2=1:1.

[0082] Exemplarily, as shown in FIG3 , the third drive electrode E22 partially covers the second piezoelectric layer PL2, and the orthographic projection of the third drive electrode E22 on the base substrate 11 is located within the orthographic projection of the second piezoelectric layer PL2 on the base substrate 11. For example, in the orthographic projection on the base substrate 11, the second piezoelectric layer PL2 is a circle with a diameter d2, and the third drive electrode E22 is a circle with a diameter d3. In this example, d3<d2.

[0083] In some embodiments, as shown in FIG. 3 or FIG. 4 , in an orthographic projection on the base substrate 11 , the third driving electrode E22 is centered relative to the second piezoelectric layer PL2 .

[0084] Exemplarily, in an orthographic projection on the base substrate 11 , the geometric center of the third driving electrode E22 roughly coincides with the geometric center of the second piezoelectric layer PL2 .

[0085] In some embodiments, as shown in FIG. 4 , in an orthographic projection on the base substrate 11 , the width of the third driving electrode E22 is substantially equal to half the width of the second piezoelectric layer PL2 .

[0086] As shown in Figure 4 , the second piezoelectric layer PL2 is circular with a diameter of d2, the third drive electrode E22 is circular with a diameter of d3, and the ratio d3:d2 = 1:2. Referring to Figure 6 , which shows a curve showing how the output energy W changes with d3 / d2, it can be seen that the output energy is highest when d3:d2 = 1:2. Therefore, this embodiment can further improve the sound pressure level of the sound-emitting device.

[0087] In some embodiments, as shown in Figure a in Figure 2, Figure 3, Figure 4 or Figure a in Figure 5, the multiple driving layers 13 include a second driving layer 132, the second piezoelectric layer PL2 includes a first piezoelectric pattern 51, and the positive projection of the first piezoelectric pattern 51 on the base substrate 11 is located within the range of the cavity structure Q.

[0088] Exemplarily, as shown in FIG. 5 a , in the orthographic projection on the base substrate 11 , the cavity structure Q is a circle with a diameter of d1 , and the first piezoelectric pattern 51 is a circle with a diameter of d2 , where d1 ≥ d2 .

[0089] It should be noted that, in FIG. 2 to FIG. 4 , the first piezoelectric pattern 51 is the second piezoelectric layer PL2 .

[0090] In some embodiments, as shown in FIG5 a, the center of the orthographic projection of the first piezoelectric pattern 51 on the base substrate 11 substantially coincides with the center of the orthographic projection of the cavity structure Q on the base substrate 11. Thus, the displacement of the diaphragm 12 at the center is the largest.

[0091] In some embodiments, as shown in Figure a in Figure 5, the second piezoelectric layer PL2 also includes a second piezoelectric pattern 52, the first piezoelectric pattern 51 and the second piezoelectric pattern 52 are in the same layer and are separated from each other, the second piezoelectric pattern 52 is symmetrically arranged on at least one side of the first piezoelectric pattern 51, and the second piezoelectric pattern 52 overlaps with the positive projection of the cavity structure Q on the base substrate 11.

[0092] By dividing the second driving layer 132 into the second piezoelectric pattern 52 and the first piezoelectric pattern 51 , this separation design can reduce the vibration damping of the diaphragm 12 .

[0093] As shown in FIG. 5 b , the second piezoelectric pattern 52 is symmetrically arranged around the first piezoelectric pattern 51 .

[0094] In order to avoid creepage, as shown in FIG. 5 a , the gap width w2 between the second piezoelectric pattern 52 and the first piezoelectric pattern 51 is greater than or equal to 0.3 mm and less than or equal to 0.5 mm.

[0095] Exemplarily, the second piezoelectric pattern 52 is symmetrically arranged on at least one side of the first piezoelectric pattern 51, which may mean that the second piezoelectric pattern 52 arranged on the periphery of the first piezoelectric pattern 51 is centrally symmetrical, and the center of symmetry is, for example, the center of symmetry or the geometric center of the first piezoelectric pattern 51. It may also mean that the second piezoelectric pattern 52 arranged on the periphery of the first piezoelectric pattern 51 is axially symmetrical, and the axis of symmetry is, for example, the axis of symmetry of the first piezoelectric pattern 51.

[0096] In some embodiments, as shown in FIG. 5 a , the second piezoelectric pattern 52 is a closed ring structure surrounding the first piezoelectric pattern 51 .

[0097] In some embodiments, as shown in Figure 5 a, in the direction in which the first piezoelectric pattern 51 points to the second piezoelectric pattern 52, the ratio of the width d4 of the second piezoelectric pattern 52 to the width d2 of the first piezoelectric pattern 51 is greater than or equal to one third and less than or equal to one half.

[0098] In some embodiments, as shown in Figure a or Figure b in Figure 5, the second driving electrode E12 includes a first electrode pattern 53 and a second electrode pattern 54 that are in the same layer and separated from each other, the orthographic projection of the first piezoelectric pattern 51 on the base substrate 11 is located within the orthographic projection range of the first electrode pattern 53 on the base substrate 11, and the orthographic projection of the second piezoelectric pattern 52 on the base substrate 11 is located within the orthographic projection range of the second electrode pattern 54 on the base substrate 11.

[0099] In some embodiments, as shown in Figure a or Figure b in Figure 5, the third driving electrode E22 includes a third electrode pattern 56 and a fourth electrode pattern 57 that are in the same layer and separated from each other, and the orthographic projection of the third electrode pattern 56 on the base substrate 11 is located within the orthographic projection range of the first piezoelectric pattern 51 on the base substrate 11, and the orthographic projection of the fourth electrode pattern 57 on the base substrate 11 is located within the orthographic projection range of the second piezoelectric pattern 52 on the base substrate 11.

[0100] In some embodiments, as shown in Figures 2 to 5, the second driving electrode E12 includes a lead area 55, which is arranged near the edge of the second driving electrode E12, and the lead area 55 does not overlap with the orthographic projections of the second piezoelectric layer PL2 and the third driving electrode E22 on the base substrate 11.

[0101] Exemplarily, as shown in FIG. 2 to FIG. 4 , when the second driving layer 132 includes only the first piezoelectric pattern 51 , the lead region 55 of the second driving electrode E12 is an annular region of the second driving electrode E12 close to its edge.

[0102] For example, as shown in FIG. 5 a or b, when the second drive electrode E12 includes a first electrode pattern 53 and a second electrode pattern 54, the lead region 55 of the second drive electrode E12 includes a first lead region 551 and a second lead region 552. The first lead region 551 is an annular region of the first electrode pattern 53 near its edge, and the second lead region 552 is an annular region of the second electrode pattern 54 near one side edge of the first electrode pattern 53. Proximity between the lead regions 55 facilitates subsequent wire bonding between the lead regions 55.

[0103] In some embodiments, the orthographic projection shape of the piezoelectric layer PL on the base substrate 11 is a centrally symmetrical figure, and the center of symmetry is the orthographic projection center of the cavity structure Q on the base substrate 11. This is conducive to improving the balance of vibration.

[0104] In some embodiments, as shown in FIG. 2 b, FIG. 2 c or FIG. 5 b, the second electrodes E2 of multiple driving layers 13 are connected to the same first lead L1, and the first electrodes E1 of multiple driving layers 13 are connected to the same second lead L2.

[0105] For example, second electrodes E2 located on the same layer and separated from each other (such as the third electrode pattern 56 and the fourth electrode pattern 57, or the plurality of sub-electrodes 21) can be connected by wire bonding, and first electrodes E1 located on the same layer and separated from each other (such as the first electrode pattern 53 and the second electrode pattern 54) can be connected by wire bonding. Second electrodes E2 located on different layers can also be connected by wire bonding, and first electrodes E1 located on different layers can also be connected by wire bonding.

[0106] Exemplarily, the number of driving layers 13 in the sound-generating device is, for example, 2, such as a first driving layer 131 and a second driving layer 132, which can avoid excessive power consumption.

[0107] The sound-generating device provided by the present disclosure is exemplarily described below with reference to FIG. 2 to FIG. 5 .

[0108] In the first to fourth examples, as shown in any one of Figures 2 to 5, the diameter of the substrate substrate 11 is 3-10 mm, the thickness of the substrate substrate 11 is 300-500 μm, the diameter of the cavity structure Q (i.e., the aperture of the blind hole H) d1 is smaller than the diameter of the substrate substrate 11, the thickness of the diaphragm 12 is 0-10 um, the thickness of the first electrode E1 and the second electrode E2 is 0.1-1 μm, the thickness of the second piezoelectric layer PL2 and the first piezoelectric layer PL1 is 2-10 μm, and the diameter of the diaphragm 12 and the first piezoelectric layer PL1 can be equal to the diameter of the substrate substrate 11, for example, 3-10 mm.

[0109] In the first example, as shown in Figure 2, the sound-generating device includes two drive layers 13: a first drive layer 131 and a second drive layer 132. The orthographic projections of the first piezoelectric layer PL1 and the fourth drive electrode E11 on the substrate 11 overlap the orthographic projection of the diaphragm 12 on the substrate 11. The first drive electrode E21 surrounds the second drive electrode E12, and a portion of the first drive electrode E21 near the second drive electrode E12 overlaps the orthographic projection of the cavity structure Q on the substrate 11. The second piezoelectric layer PL2 includes only the first piezoelectric pattern 51, and the diameter d2 of the first piezoelectric pattern 51 is smaller than the diameter d1 of the cavity structure Q. The third drive electrode E22 completely overlaps with the orthographic projection of the second piezoelectric layer PL2 (i.e., the first piezoelectric pattern 51) on the substrate 11. The diameter d3 of the third drive electrode E22 is equal to the diameter d2 of the first piezoelectric pattern 51. The second drive electrode E12 has a lead region 55 near its edge, which is exposed for subsequent wire bonding.

[0110] FIG7 shows a comparison of the sound pressure levels of the sound-generating device DV1 shown in FIG1 and the sound-generating device DV2 shown in FIG2 . The abscissa of FIG7 represents frequency f, and the ordinate represents sound pressure level SP. It can be seen that, under the same driving voltage, the sound pressure level of the sound-generating device DV2 provided in this example is approximately 20-25 dB higher than that of the sound-generating device DV1 shown in FIG1 .

[0111] In the second example, as shown in FIG. 3 , the diameter of the third driving electrode E22 is reduced based on the first example, that is, the diameter d3 of the third driving electrode E22 is smaller than the diameter d2 of the first piezoelectric pattern 51 .

[0112] In the third example, as shown in FIG4 , the diameter of the third drive electrode E22 is reduced based on the first example. That is, the diameter d3 of the third drive electrode E22 is smaller than the diameter d2 of the first piezoelectric pattern 51, and d3 = d2 / 2. Furthermore, the orthographic projection of the first drive electrode E21 on the base substrate 11 is within the orthographic projection range of the cavity structure Q on the base substrate 11, and the outer contour of the orthographic projection of the first drive electrode E21 on the base substrate 11 is substantially flush with the outer contour of the orthographic projection of the cavity structure Q on the base substrate 11.

[0113] In the fourth example, as shown in FIG5 , the sound-generating device includes two drive layers 13: a first drive layer 131 and a second drive layer 132. The orthographic projections of the first piezoelectric layer PL1 and the fourth drive electrode E11 on the substrate 11 overlap the orthographic projection of the diaphragm 12 on the substrate 11. The first drive electrode E21 surrounds the second drive electrode E12, and the first drive electrode E21 does not overlap with the orthographic projection of the cavity structure Q on the substrate 11. The second piezoelectric layer PL2 includes a first piezoelectric pattern 51 and a second piezoelectric pattern 52. The diameter d2 of the first piezoelectric pattern 51 is smaller than the diameter d1 of the cavity structure Q, and the width of the second piezoelectric pattern 52 is d2 / 2. The third drive electrode E22 completely overlaps with the orthographic projection of the second piezoelectric layer PL2 on the substrate 11. The lead region 55 of the second drive electrode E12 includes a first lead region 551 and a second lead region 552.

[0114] FIG8 shows a comparison of the sound pressure levels of the sound-generating device DV1 shown in FIG1 and the sound-generating device DV5 shown in FIG5 . The abscissa of FIG8 represents frequency f, and the ordinate represents sound pressure level SP. It can be seen that, under the same driving voltage, the sound pressure level of the sound-generating device DV5 provided in this example is approximately 25-30 dB higher than that of the sound-generating device DV1 shown in FIG1 .

[0115] The present disclosure provides a sound-generating device, comprising a sound-generating device as provided in any embodiment, and a driving circuit connected to the sound-generating device and configured to provide a driving signal to a first electrode and a second electrode in the driving layer.

[0116] Those skilled in the art will appreciate that the sound-generating device provided by the present disclosure has the advantages of the above-mentioned sound-generating devices.

[0117] The sound-generating device provided in the present disclosure is a MEMS speaker, a piezoelectric speaker, or a MEMS piezoelectric speaker, etc. The sound-generating device provided in the present disclosure is, for example, an electronic device including a MEMS speaker, a piezoelectric speaker, or a MEMS piezoelectric speaker, etc.

[0118] In the present disclosure, “a plurality of” means two or more, and “at least one” means one or more, unless otherwise clearly defined.

[0119] In the present disclosure, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation on the present disclosure.

[0120] In this disclosure, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, product, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, commodity, or apparatus that includes the element.

[0121] References in this disclosure to "one embodiment," "some embodiments," "exemplary embodiments," "one or more embodiments," "an example," "an example," "some examples," and the like are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the disclosure. Schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be included in any one or more embodiments or examples in any suitable manner.

[0122] In this disclosure, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0123] When describing some embodiments, the expressions "coupled" and "connected" may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this disclosure.

[0124] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0125] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0126] As used in this disclosure, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0127] The use of "for" or "configured to" in this disclosure is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0128] The use of "based on" or "according to" in this disclosure is intended to be open and inclusive. A process, step, calculation, or other action based on one or more stated conditions or values ​​may, in practice, be based on other conditions or values ​​beyond the stated values. A process, step, calculation, or other action based on one or more stated conditions or values ​​may, in practice, be based on other conditions or values ​​beyond the stated values.

[0129] As used in this disclosure, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0130] As used in this disclosure, "parallel", "perpendicular", "equal", and "flush" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, the difference between the two being equal is less than or equal to 5% of either one. "Flush" includes absolute flushness and approximate flushness, wherein the acceptable deviation range of approximate flushness can be, for example, the distance between the two being flush is less than or equal to 5% of either one's size.

[0131] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0132] The present disclosure describes exemplary embodiments with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown in this disclosure, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A sound-generating device, comprising: A base substrate, wherein a blind hole is provided on one side surface of the base substrate, the bottom of the blind hole forms a diaphragm, and the bottom of the blind hole and the hole wall together form a cavity structure; as well as A plurality of driving layers are stacked on one side of the base substrate and disposed close to the diaphragm, the driving layers comprising a first electrode, a piezoelectric layer, and a second electrode stacked in sequence, the first electrode being disposed close to the diaphragm; Among them, the orthographic projections of the first electrode, piezoelectric layer and second electrode of at least one of the driving layers on the base substrate have an overlapping area with the orthographic projection of the cavity structure on the base substrate, and the orthographic projections of the piezoelectric layer of each driving layer and the cavity structure on the base substrate all overlap.

2. The sound-generating device according to claim 1, wherein: The plurality of driving layers include a first driving layer and a second driving layer, wherein the first driving layer is located between the diaphragm and the second driving layer; The second electrode of the first driving layer is a first driving electrode, the first electrode of the second driving layer is a second driving electrode, the second driving electrode and the first driving electrode are in the same layer and are separated from each other, and the first driving electrode is symmetrically arranged on at least one side of the second driving electrode.

3. The sound-generating device according to claim 2, wherein: The first driving electrode is a closed ring structure surrounding the second driving electrode.

4. The sound-generating device according to claim 2, wherein: The first driving electrode is a non-closed ring structure arranged around the second driving electrode.

5. The sound-generating device according to claim 4, wherein: The first driving electrode includes a plurality of sub-electrodes, and the plurality of sub-electrodes are arranged at equal intervals in a direction surrounding the second driving electrode.

6. The sound-generating device according to claim 5, wherein: The minimum distance between two adjacent sub-electrodes is greater than or equal to 0.1 mm and less than or equal to 0.6 mm; and / or The two adjacent sub-electrodes are a first sub-electrode and a second sub-electrode. In the orthographic projection on the substrate, the angle between the side of the first sub-electrode close to the second sub-electrode and the first straight line is greater than or equal to 30° and less than or equal to 90°, and the opening of the angle faces away from the second sub-electrode. electrode, the first straight line is a straight line connecting the center of the first sub-electrode and the center of the second sub-electrode.

7. The sound-generating device according to claim 2, wherein: The first driving electrode overlaps with an orthographic projection of the cavity structure on the base substrate.

8. The sound-generating device according to claim 1, wherein: The plurality of driving layers include a second driving layer, the second driving layer is a driving layer away from the diaphragm, the piezoelectric layer of the second driving layer is a second piezoelectric layer, and the second electrode of the second driving layer is a third driving electrode; and The third driving electrode completely covers the second piezoelectric layer, and the third driving electrode and the orthographic projection of the second piezoelectric layer on the substrate completely overlap; or The third driving electrode partially covers the second piezoelectric layer, and the orthographic projection of the third driving electrode on the base substrate is located within the orthographic projection range of the second piezoelectric layer on the base substrate.

9. The sound-generating device according to claim 8, wherein: In an orthographic projection on the base substrate, the third driving electrode is centered relative to the second piezoelectric layer.

10. The sound-generating device according to claim 9, wherein: In an orthographic projection on the base substrate, a width of the third driving electrode is substantially equal to half a width of the second piezoelectric layer.

11. The sound-generating device according to claim 8, wherein: The first electrode of the second driving layer is a second driving electrode, and the second driving electrode includes a lead area. The lead area is arranged near the edge of the second driving electrode, and the lead area has no overlap with the second piezoelectric layer and the orthographic projection of the third driving electrode on the substrate.

12. The sound-generating device according to claim 1, wherein: The plurality of driving layers include a second driving layer, the piezoelectric layer of the second driving layer includes a first piezoelectric pattern, and an orthographic projection of the first piezoelectric pattern on the base substrate is located within the range of the cavity structure.

13. The sound-generating device according to claim 12, wherein: The orthographic projection center of the first piezoelectric pattern on the base substrate substantially coincides with the orthographic projection center of the cavity structure on the base substrate.

14. The sound-generating device according to claim 12, wherein: The piezoelectric layer of the second driving layer also includes a second piezoelectric pattern. The first piezoelectric pattern and the second piezoelectric pattern are in the same layer and are separated from each other. The second piezoelectric pattern is symmetrically arranged on at least one side of the first piezoelectric pattern. The second piezoelectric pattern overlaps with the orthographic projection of the cavity structure on the base substrate.

15. The sound-generating device according to claim 14, wherein: The second piezoelectric pattern is a closed ring structure surrounding the first piezoelectric pattern.

16. The sound-generating device according to claim 14, wherein: In a direction from the first piezoelectric pattern to the second piezoelectric pattern, a ratio of a width of the second piezoelectric pattern to a width of the first piezoelectric pattern is greater than or equal to one third and less than or equal to one half.

17. The sound-generating device according to claim 14, wherein: The second driving electrode includes a first electrode pattern and a second electrode pattern in the same layer and separated from each other, the orthographic projection of the first piezoelectric pattern on the base substrate is located within the orthographic projection range of the first electrode pattern on the base substrate, and the orthographic projection of the second piezoelectric pattern on the base substrate is located within the orthographic projection range of the second electrode pattern on the base substrate.

18. The sound-generating device according to claim 1, wherein: The orthographic projection shape of the piezoelectric layer on the substrate is a centrally symmetrical figure, and the center of symmetry is the orthographic projection center of the cavity structure on the substrate.

19. The sound-generating device according to claim 1, wherein: The second electrodes of the plurality of driving layers are connected to a same first lead line, and the first electrodes of the plurality of driving layers are connected to a same second lead line.

20. A sound-generating device, comprising: The sound-generating device according to any one of claims 1 to 19; as well as The driving circuit is connected to the sound generating device and is used to provide a driving signal to the first electrode and the second electrode in the driving layer.

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