SOUND TRANSDUCER ARRANGEMENT

Description

[0001] The present invention relates to a MEMS sound transducer, in particular for generating and / or detecting sound waves in the audible wavelength spectrum, comprising a carrier, a membrane which is connected to the carrier and can be deflected relative thereto along a stroke axis, at least one piezo element which is spaced apart from the membrane in the direction of the stroke axis and for generating and / or detecting a deflection of the membrane, which comprises a first end connected to the carrier and a second end which can be deflected in the direction of the stroke axis, and a coupling element which extends in the direction of the stroke axis between the piezo element and the membrane and connects the second end of the piezo element to the membrane.

[0002] WO 2016 / 034665 A1 discloses a MEMS comprising a membrane, a lifting structure coupled to the membrane, and at least two piezoelectric actuators connected to a plurality of spaced-apart contact points of the lifting structure via a plurality of spaced-apart connecting elements. The at least two piezoelectric actuators are configured to induce a lifting movement of the lifting structure to deflect the membrane. However, a disadvantage of this MEMS is that its performance is limited.

[0003] The object of the present invention is to improve the state of the art.

[0004] The object is achieved by a MEMS sound transducer having the features of independent patent claim 1, which defines the invention.

[0005] A MEMS sound transducer is proposed, which can be operated, for example, to generate and / or detect sound waves in the audible wavelength spectrum. The MEMS sound transducer can be arranged, for example, in a smartphone, headphones, or other electronic device. However, the MEMS sound transducer can also be operated to generate and / or detect ultrasonic waves. The MEMS sound transducer can then be arranged, for example, in medical and / or technical diagnostic devices, in distance sensors, or similar devices.

[0006] The MEMS sound transducer further comprises a support and a diaphragm, which is connected to the support and can be deflected relative to it along a stroke axis. The diaphragm can be connected to the support along its entire edge area. The diaphragm can be used to generate sound waves. The diaphragm can be set into vibration, which also causes the air arranged above the diaphragm to vibrate. The propagating vibrations are the sound waves that carry a sound. The diaphragm can also be set into vibration. When sound waves hit the diaphragm, it also begins to vibrate.

[0007] Furthermore, the MEMS sound transducer has at least one piezo element spaced from the membrane in the direction of the stroke axis for generating and / or detecting a deflection of the membrane. The piezo element can be deflected using an electrical voltage. If the piezo element itself is deflected by a force acting on it, it generates an electrical voltage. The piezo element has a first end connected to the carrier. Furthermore, the piezo element has a second end that can be deflected in the direction of the stroke axis.

[0008] To connect the second end of the piezo element to the diaphragm, the MEMS sound transducer has a coupling element that extends in the direction of the stroke axis between the piezo element and the diaphragm. Using the coupling element, the deflection of the piezo element generated by the electrical voltage can be transmitted to the diaphragm to generate sound waves. Using an electrical signal, the diaphragm can be set into corresponding vibrations by the coupling element, so that, for example, a sound can be generated. The vibrations of the sound waves can also be transmitted from the diaphragm to the piezo element with the help of the coupling element, which converts them into an electrical signal.

[0009] Furthermore, the at least one piezo element and the coupling element together form a cantilever arm clamped at one end, which has a clamped end formed by the first end of the piezo element and a free end formed by the coupling element. This allows the cantilever arm to oscillate freely at the free end. As a result, the piezo element can experience a high deflection along the stroke axis. For example, this can be used to generate sound waves with a high amplitude.

[0010] Furthermore, the MEMS sound transducer exhibits high linearity. When the piezo element is exposed to the electrical signal, the free end deflects. Because the piezo element and the coupling element are designed as a cantilever, the deflection of the free end is linearly proportional to the instantaneous amplitude of the electrical signal. The resulting sound waves also have a sound amplitude that is linearly proportional to the deflection of the free end. The sound waves generated from the electrical signal using the MEMS sound transducer according to the invention thus exhibit high linearity.

[0011] By designing the piezo element and the coupling element as a cantilever, the piezo element can also apply a high force to the membrane. This allows the membrane to be advantageously deflected or set into vibration.

[0012] Furthermore, the MEMS transducer features multiple cantilever arms, allowing the membrane to be deflected with greater force.

[0013] According to the invention, at least two cantilever arms are arranged one behind the other in a plan view. The at least two cantilever arms can thus be arranged in alignment one behind the other. The at least two cantilever arms can be arranged relative to one another such that they extend along a common line. This allows the MEMS sound transducer to be designed in a space-saving manner, since the width of the MEMS sound transducer can be kept small by arranging the cantilever arms one behind the other. Furthermore, this allows the membrane to be deflected linearly, i.e., linearly with the deflection of the two cantilever arms.

[0014] In an advantageous development of the invention, the cantilever arm is connected exclusively to the diaphragm in the area of ​​its free end. This allows the free end to oscillate freely, without being influenced by anything else. The free end's oscillation is not inhibited or slowed down by another component, for example. This enables, for example, the high linearity of the MEMS sound transducer. Likewise, a high deflection of the diaphragm can be achieved with a high force.

[0015] It is also advantageous if, in a side view, a free space is formed between the side of the coupling element facing away from the actuator and the support. This spaced the coupling element from the support and allows it to oscillate freely.

[0016] It is also advantageous if the free space has a U-shape in plan view, so that the cantilever is spaced from the beam at its free end and both long sides. This ensures that only the clamped end of the cantilever is in contact with the beam, allowing the long sides and the free end to swing freely relative to the beam.

[0017] The support has at least one recess in which the cantilever arm is arranged. The recess can be completely enclosed by the support. Furthermore, the recess can extend completely through the support in the direction of the lifting axis, so that the recess has an upper and a lower opening. One of the two openings can be covered by the membrane.

[0018] Having only a single cantilever arm in the recess also offers advantages. The cantilever arm cannot be restricted in its deflection along the lifting axis by another cantilever arm.

[0019] It is also advantageous if the MEMS sound transducer has several cantilever arms arranged side by side in plan view. This increases the force acting on the membrane. Furthermore, with several spaced-apart cantilevers, the membrane can be deflected evenly and, in particular, over a large area. As a result, the sound waves can be generated and / or detected over a large area. The cantilevers can thus be arranged, for example, in a square, a rectangle, or another flat geometric figure or polygon. One cantilever arm can be arranged in each corner of said figure or polygon.

[0020] At least two cantilevers are oriented in the same direction. This allows the membrane to be deflected advantageously.

[0021] Furthermore, it is advantageous if at least two adjacent and similarly oriented cantilever arms are connected to each other by means of the coupling element in the area of ​​the free end. When the two cantilever arms are arranged next to each other, their long sides face each other. By connecting the two cantilever arms by means of the coupling element, the force of both cantilever arms can be combined during deflection.

[0022] It is advantageous if the coupling element is connected to the piezo element by means of a joint, allowing the coupling element to be rotated relative to the piezo element. The joint can be, for example, an elastic or flexible joint. The rotatability of the coupling element allows the coupling element to remain aligned parallel to the membrane when the piezo element is deflected. This reduces the stress on the membrane in the contact area between the coupling element and the membrane.

[0023] It is also advantageous if the piezo element and the coupling element are formed from a single piece of material. This allows, for example, the piezo element and the coupling element arranged thereon to be manufactured in a single manufacturing step.

[0024] Furthermore, it is advantageous if the MEMS transducer is a MEMS loudspeaker. Additionally or alternatively, the MEMS transducer can also be a MEMS microphone.

[0025] Further advantages of the invention are described in the following embodiments. Only the embodiment according to Figure 4 falls under the claims. They show: Figure 1 a perspective view of a MEMS sound transducer with a carrier, a piezo element and a coupling element, Figure 2 a side sectional view of a MEMS transducer with a cantilever arm, Figure 3 a side sectional view of a MEMS transducer with two oppositely oriented cantilever arms, Figure 4 a side sectional view of a MEMS transducer with two equally oriented cantilever arms, Figure 5 a top view of a MEMS transducer with two cantilever arms, Figure 6 a top view of a MEMS transducer with a cantilever arm, Figure 7 a side sectional view of a MEMS transducer with two cantilever arms and a coupling plate and Figure 8a side sectional view of a MEMS transducer with a spacer element between the membrane and coupling elements.

[0026] Figure 1 shows a perspective view of a MEMS sound transducer 1. To explain its functionality, only a cantilever arm 9 is shown initially. Using the MEMS sound transducer 1, for example, sound waves in the audible wavelength spectrum can be generated, allowing it to be operated as a MEMS loudspeaker. Additionally or alternatively, the MEMS sound transducer 1 can also be used to detect sound waves in the audible wavelength spectrum, allowing it to be operated as a MEMS microphone. The MEMS sound transducer 1 can also be arranged in a smartphone, for example, to enable telephone calls or listening to music. The MEMS sound transducer 1 can also be arranged in headphones, for example.

[0027] Another application area for the MEMS sound transducer 1 can also be the generation and / or detection of ultrasonic waves. The MEMS sound transducer 1 can be arranged, for example, in an ultrasonic sensor, such as a distance sensor.

[0028] The MEMS sound transducer 1 further comprises a carrier 2, which can form a basic framework of the MEMS sound transducer 1. The carrier 2 can, for example, comprise a semiconductor substrate that can be produced using an etching process. A membrane 3 (not shown here) can be arranged on the carrier 2 and, for example, is fully connected to the carrier 2. The membrane 3 can be deflected along a stroke axis 4. With the help of the deflection of the membrane 3, the air arranged above it can be set into vibration, so that the sound waves are generated. However, the membrane 3 itself can also be set into vibration by the vibrating air and thus deflected. The membrane 3 can thus detect the sound waves.

[0029] To detect and / or generate the deflection of the membrane 3, the MEMS sound transducer 1 comprises at least one piezo element 5 spaced apart from the membrane 3 in the direction of the stroke axis 4. The piezo element 5 can be deflected by an electrical signal, which includes, for example, music, whereby the deflection is transmitted to the membrane 3, so that the sound waves are generated. The piezo element 5 thus acts as a piezo actuator. The MEMS sound transducer 1 is operated as a MEMS loudspeaker in this case. If, however, the piezo element 5 is deflected by the membrane 3, the piezo element 5 generates an electrical signal that corresponds to the sound waves picked up by the membrane 3. The piezo element 5 thus acts as a piezo sensor. The MEMS sound transducer 1 is then operated as a MEMS microphone.

[0030] The piezo element 5 also has a first end 6 connected to the carrier 2. Furthermore, the piezo element 5 comprises a second end 7 that can be deflected in the direction of the stroke axis 4.

[0031] Likewise, the MEMS sound transducer 1 has a coupling element 8 that extends in the direction of the stroke axis 4 between the piezo element 5 and the diaphragm 3 and connects the second end 7 of the piezo element 5 to the diaphragm 3. The coupling element 8 thus transmits the deflection of the piezo element 5 to the diaphragm 3 when the MEMS sound transducer 1 is operated as a loudspeaker. Furthermore, the coupling element 8 transmits the deflection of the diaphragm 3 to the piezo element 5 when the MEMS sound transducer 1 is operated as a microphone.

[0032] Preferably, the carrier 2 and the coupling element 8 can be formed from the same material, such as a semiconductor material. Furthermore, the carrier 2 and the coupling element 8 can have the same thickness in the direction of the stroke axis 4. For example, the carrier 2 and the coupling element 8 can be formed together using a layering process, wherein the cavities around the carrier 2 and / or around the coupling element 8 are removed using an etching process. Additionally, the piezo element 5 can also be formed with the carrier 2 and / or the coupling element 8 using the layering process.

[0033] Furthermore, the at least one piezo element 5 and the coupling element 8 together form a cantilever arm 9 clamped on one side. The cantilever arm 9 has a clamped end 10 formed by the first end 6 of the piezo element 5 and a free end 11 formed by the coupling element 8. The piezo element 5 can form a cantilever with the coupling element 8, which is connected to the carrier 2 at the clamped end 10. The free end 11 of the cantilever arm 9 can oscillate freely if it is connected exclusively to the membrane 3. In particular, the free end 11 has no connection to the carrier 2 and / or to a piezo element 5 opposite the first. The free end 11 is decoupled from the carrier 2. As a result, the free end 11 can oscillate freely. The free end 11 is not hindered in its oscillation. This allows the free end 11 to be deflected widely so that sound waves with a high amplitude can be generated and / or detected.

[0034] This also ensures high linearity. The amplitude of the electrical signal can be converted into a linearly proportional amplitude of the sound waves. The same applies when the MEMS sound transducer 1 is operated as a microphone. Then the amplitude of the sound waves can be converted into a linearly proportional electrical signal. Furthermore, the cantilever arm 9 allows the membrane 3 to be deflected with a high force, since the free end 11 can move freely.

[0035] The coupling element 8 can further be arranged on the piezo element 5 by means of an articulated connection 14a, 14b, which can be designed to be elastic. Additionally or alternatively, the articulated connection 14a, 14b can also be flexible. With the aid of the articulated connection 14a, 14b, the coupling element 8 can be rotated relative to the piezo element 5 when the cantilever arm 9 is deflected along the stroke axis 4, so that the coupling element 8 can remain oriented parallel to the membrane 3. The articulated connection 14a, 14b is preferably formed by at least one flexible and / or elastic connecting element. The piezo element 5 is preferably formed from several layers, in particular at least one piezo layer, a carrier layer, and / or an electrode layer. The at least one connecting element is preferably formed by one of these layers, in particular by the carrier layer.

[0036] The MEMS sound transducer 1 can furthermore according to the present embodiment of the Figure 1 In a side view, the coupling element 8 has a free space 12 between the side of the coupling element 8 facing away from the piezo element 5 and the support 2. With the help of the free space 12, the cantilever arm 9 can swing freely.

[0037] Furthermore, the support 2 has a recess 13 in which the cantilever arm 9 is arranged. In the present embodiment, the recess 13 is completely surrounded by the support 2. Furthermore, the recess 13 extends completely through the support 2 in the direction of the lifting axis 4.

[0038] In the description of the following exemplary embodiments, the same reference numerals are used for features that are identical or at least comparable in their design and / or mode of operation to the respective preceding exemplary embodiments. Unless explained in detail again, their design and / or mode of operation corresponds to that of the features already described above.

[0039] Figure 2 shows a side sectional view of the MEMS transducer 1, as used for example in Figure 1 is shown. Here, the membrane 3 is arranged on the carrier 2. In the present embodiment, the membrane 3 is arranged on a carrier element 15 that is connected to the carrier 2. The membrane 3 can also be stretched over the carrier element 15. The carrier element 15 can thus form a frame for the membrane 3.

[0040] The membrane 3 can further be arranged in the region of a top side 21 of the MEMS sound transducer 1. The MEMS sound transducer 1 further has a bottom side 20 opposite the top side 21. According to the present embodiment, the piezo element 5 can be arranged in the region of the bottom side 20. The coupling element 8 consequently extends from the piezo element 5 from the bottom side 20 to the membrane 3 on the top side 21.

[0041] According to the present embodiment, the MEMS sound transducer 1 has a coupling plate 16, which is arranged between the coupling element 8 and the membrane 3 and couples them together. The coupling plate 16 is arranged in the region of the upper side 21 of the MEMS sound transducer 1. The coupling plate 16 provides a planar force transmission between the coupling element 8 and the membrane 3.

[0042] Figure 3shows another embodiment of a MEMS sound transducer 1 with two cantilever arms 9a, 9b. Each of the two cantilever arms 9a, 9b has a coupling element 8a, 8b and a piezo element 5a, 5b. The free space 12 is arranged between the two coupling elements 8a, 8b. The two cantilever arms 9a, 9b are decoupled from each other. The two cantilever arms 9a, 9b are only connected to the membrane 3. According to the present embodiment, each coupling element 8a, 8b is assigned a coupling plate 16a, 16b, which connects the respective coupling element 8a, 8b to the membrane 3.

[0043] The two cantilever arms 9a, 9b are oriented opposite to each other. The two free ends 11a, 11b of the two cantilever arms 9a, 9b face each other. The two cantilever arms 9a, 9b are connected to each other only via the membrane 3. The two cantilever arms 9a, 9b are arranged one behind the other here. Arranged one behind the other can mean that the at least two cantilever arms 9a, 9b are only translationally offset from each other in a transverse direction of the MEMS sound transducer 1. The at least two cantilever arms 9a, 9b can, for example, be arranged in a line. The MEMS sound transducer 1 of the exemplary embodiment of the present Figure 3 has the recess 13 in which both cantilever arms 9a, 9b are arranged.

[0044] Figure 4shows a further embodiment of a MEMS sound transducer 1 with two identically oriented cantilever arms 9a, 9b. The MEMS sound transducer 1 has two recesses 13a, 13b, with a cantilever arm 9a, 9b arranged in each recess 13a, 13b. The two recesses 13a, 13b are separated from each other by a center piece 17 of the support 2. The second cantilever arm 9b is arranged on the center piece 17. The first cantilever arm 9a and the second cantilever arm 9b are identically aligned and / or oriented to each other. However, the first cantilever arm 9a and the second cantilever arm 9b are translationally offset from each other in the transverse direction of the MEMS sound transducer 1. The two cantilever arms 9a, 9b are arranged one behind the other here. Arranged one behind the other can mean that the at least two cantilever arms 9a, 9b are only translationally offset from one another in a transverse direction of the MEMS sound transducer 1.The at least two cantilever arms 9a, 9b can, for example, be arranged in a line. They thus have the same range of motion relative to each other, but engage the membrane 3 in different translationally offset regions.

[0045] The membrane 3 extends over the middle piece 17. According to the present embodiment of the Figure 4 A gap 18 is formed between the center piece 17 of the carrier 2 and the membrane 3 in the neutral position of the membrane 3. The membrane 3 is thus spaced from the center piece 17 of the carrier 2. The membrane 3 is consequently decoupled from the center piece 17. In the present case, the carrier 2 is just as thick in the area of ​​the center piece 17 as in its edge area. Alternatively, the center piece 17 could also be thinner than the edge area, so that the gap 18 or the distance between the membrane 3 and the center piece 17 is increased (cf. Figure 7). Alternatively, the membrane 3 could also rest loosely on the center piece 17 in its neutral position. In an alternative embodiment, the membrane 3 can also be connected, in particular glued, to the center piece 17 of the carrier 2.

[0046] With the help of the two cantilever arms 9a, 9b, the membrane 3 can be deflected even further. Furthermore, the membrane 3 can be deflected with greater force and evenly across its surface.

[0047] Figure 5shows a further embodiment of a MEMS sound transducer 1 in a plan view with two cantilever arms 9a, 9b. The two cantilever arms 9a, 9b are arranged next to each other and oriented in the same way. The two cantilever arms 9a, 9b furthermore have longitudinal sides 19a - 19d, which are each parallel to each other. The first longitudinal side 19a of the first cantilever arm 9a and the second longitudinal side 19d of the second cantilever arm 9b face the support 2 and are spaced apart therefrom. The second longitudinal side 19b of the first cantilever arm 9a and the first longitudinal side 19c of the second cantilever arm 9b face each other and are spaced apart from each other. The free space 12 is thus arranged in a U-shape around the respective cantilever arm 9a, 9b. The free space 12 thus has, in this plan view, the Figure 5 a U-shape around each cantilever arm 9a, 9b. The free space 12 around both cantilevers 9a, 9b has a W-shape.

[0048] The two cantilever arms 9a, 9b have no direct connection to each other. They are decoupled from each other. The two cantilever arms 9a, 9b are only connected to the membrane 3.

[0049] By arranging the cantilever arms 9a, 9b next to one another and one behind the other, the multiple cantilever arms 9a, 9b can be arranged over a large area. This requires at least three cantilever arms 9. For example, two cantilever arms 9a, 9b can be arranged according to the exemplary embodiment shown here, and at least one further cantilever arm can be arranged behind one of the two cantilever arms 9a, 9b. This results in at least two cantilever arms 9 being arranged one behind the other. The three cantilever arms 9 can then be arranged in the geometric shape of a right-angled triangle, with one cantilever arm 9 in each corner of the right-angled triangle. This allows the membrane 3 to be deflected over a large area. However, the three cantilever arms 9 can also be arranged in an isosceles or equilateral triangle.

[0050] Alternatively, cantilevers can also be arranged in another geometric shape, with the number of corners of the geometric shape corresponding to the number of cantilevers. For example, four cantilevers can be arranged in a square, a rectangle, a trapezoid, a rhombus, or an irregular quadrilateral.

[0051] Figure 6 shows another embodiment of a MEMS sound transducer 1 with a cantilever arm 9 comprising two piezo elements 5a, 5b and a coupling element 8. The two piezo elements 5a, 5b are arranged side by side and oriented in the same direction. In the region of their second ends 7a, 7b, the two piezo elements 5a, 5b are connected to each other by a coupling element 8. This allows the membrane 3 to be deflected with a high force.

[0052] The first longitudinal side 19a and the second longitudinal side 19b of the cantilever arm 9 are each spaced apart from the beam 2. The free space 12 is U-shaped here and extends around the cantilever arm 9. This allows the free end 11 of the cantilever arm 9 to deflect freely along the lifting axis 4.

[0053] Figure 7 shows a further embodiment of a MEMS sound transducer 1 comprising two cantilever arms 9a, 9b. The two cantilever arms 9a, 9b are oriented identically to one another, with the second cantilever arm 9b being arranged on the center piece 17 of the support 2. In the present embodiment, the two coupling elements 8a, 8b of the two cantilever arms 9a, 9b are connected by means of the same, in particular single, coupling plate 16 of the membrane 3. This allows the membrane 3 to be deflected synchronously by the two cantilever arms 9a, 9b. The coupling plate 16 extends in the transverse direction of the MEMS sound transducer 1 over both the first coupling element 8a and the second coupling element 8b.

[0054] According to the present embodiment, the gap 18 is larger than the gap 18 of the Figure 4 formed. For this purpose, the central piece 17 is thinner than the edge region of the carrier 2. The gap 18 is preferably approximately half the thickness of the edge region of the carrier 2 in the direction of the stroke axis 4. This allows the diaphragm 3 to deflect far in the direction of the central piece 17 without hitting it. Alternatively, however, the central piece 17 can also reach up to the coupling plate 16, so that the coupling plate 16 rests loosely on the central piece 17 when the diaphragm 3 is in the neutral position. The central piece 17 can therefore also be just as thick as the edge region of the carrier 2. However, the rigid coupling plate 16 extending over the central piece 17 is decoupled from the central piece 17, in particular is spaced from it when the diaphragm 3 is in the neutral position.

[0055] In addition, the two cantilever arms 9a, 9b can also have the joints 14a-d or connecting elements (not shown here). This allows the coupling elements 8a, 8b of the cantilever arms 9a, 9b to rotate relative to the corresponding piezo elements 5a, 5b, so that the coupling elements 8a, 8b remain aligned parallel to the membrane 3 during its deflection.

[0056] The cantilever arms 9a, 9b are arranged one behind the other here. The at least two cantilever arms 9a, 9b can thus be arranged in a line. In an alternative embodiment, several, for example three or four, cantilever arms 9 can be arranged one behind the other, in particular in a line. In addition, at least one cantilever arm 9 can be arranged next to at least one of the cantilever arms 9a, 9b shown here. Two cantilever arms 9a, 9b arranged next to one another are, for example, Figure 5 shown.

[0057] Figure 8shows a further embodiment of a MEMS sound transducer 1. A spacer element 22a, 22b is arranged between the membrane 3 and the two coupling elements 8a, 8b of this embodiment. The spacer elements 22a, 22b can have a thickness in the direction of the stroke axis 4 that is comparable to that of the carrier 2 and / or the carrier element 15. In particular, a sum of the thicknesses of the spacer elements 22a, 22b and a thickness of the coupling plate 16 can correspond to the thickness of the carrier element 15. The spacer elements 22a, 22b can, for example, be adhesively bonded to the coupling elements 8a, 8b using a manufacturing process. The spacer elements 22a, 22b can, for example, increase the volume of the free spaces 12a, 12b and the recesses 13a, 13b. This allows the acoustic properties of the MEMS sound transducer 1 to be adjusted.

[0058] According to Figure 8Furthermore, the gap 18 is arranged between the central piece 17 and the membrane 3, which gap is widened by the fact that the spacer elements 22a, 22b are arranged between the membrane 3 and the coupling elements 8a, 8b.

[0059] Here again, several cantilever arms 9a, 9b can be arranged next to each other, as for example in Figure 5 shown and described. The two cantilever arms 9a, 9b shown here are again arranged one behind the other. However, several cantilever arms 9a, 9b can also be arranged one behind the other.

[0060] The present invention is not limited to the illustrated and described embodiments. Rather, the invention is defined by the following claims. List of reference symbols

[0061] 1MEMS transducer 2Support 3Membrane 4Stroke axis 5Piezo element 6First end 7Second end 8Coupling element 9Cantilever arm 10Clamped end 11Free end 12Free space 13Recess 14Joint connection 15Support element 16Coupling plate 17Middle piece 18Gap 19Long side 20Bottom side 21Top side 22Spacer element

Claims

1. MEMS sound transducer (1), in particular for generating and / or detecting sound waves in the audible wavelength spectrum, having a carrier (2), having a diaphragm (3) which is connected to the carrier (2) and can be deflected with respect to the latter along a stroke axis (4a, 4b), and having a first and a second cantilever arm (9a, 9b) which are clamped on one side and are each arranged in a recess (13a, 13b) of the carrier (2), which each comprise a piezo element (5a, 5b), which is spaced apart from the diaphragm (3) in the direction of the stroke axis (4), for generating and / or detecting a deflection of the diaphragm (3), which piezo element comprises a first end (6a, 6b), which is connected to the carrier (2), and a second end (7a, 7b), which can be deflected in the direction of the stroke axis (4a, 4b), and a coupling element (8a, 8b) which extends in the direction of the stroke axis (4a, 4b) between the piezo element (5a, 5b) and the diaphragm (3) and connects the second end (7a, 7b) of the piezo element (5a, 5b) to the diaphragm (3), so that the respective piezo element (5a, 5b) and the respective coupling element (8a, 8b) together form the respective cantilever arm (9a, 9b) which is clamped on one side and has a clamped end (10a, 10b) formed by the first end (6a, 6b) of its piezo element (5a, 5b) and a free end (11a, 11b) formed by its coupling element (8a, 8b), and wherein the two cantilever arms (9a, 9b) are arranged one behind the other in a top view parallel to the stroke axis, so that the two cantilever arms (9a, 9b) are offset translationally with respect to one another in a transverse direction of the MEMS sound transducer (1) running perpendicular to the stroke axis, characterized in that the MEMS sound transducer (1) has two recesses (13a, 13b), wherein one of the two cantilever arms (9a, 9b) is arranged in each case in one of the recesses (13a, 13b), the two recesses (13a, 13b) are separated from one another by a center piece (17) of the carrier (2), the first cantilever arm (9a) is arranged on an edge region of the carrier (2) and the second cantilever arm (9b) is arranged on the center piece (17) of the carrier (2), and the two cantilever arms (9a, 9b) are aligned identically with respect to one another and / or are oriented identically with respect to one another.

2. MEMS sound transducer according to the preceding claim, characterized in that the respective cantilever arm (9a, 9b) is connected exclusively to the diaphragm (3) in the region of its free end (11a, 11b).

3. MEMS sound transducer according to at least one of the preceding claims, characterized in that, in the case of the cantilever arms (9a, 9b), a free space (12) is formed in each case in a side view between that side of the coupling element (8a, 8b) which faces away from the piezo element (5a, 5b) and the carrier.

4. MEMS sound transducer according to at least one of the preceding claims, characterized in that, in the case of the cantilever arms (9a, 9b), a free space (12) in each case has a U shape in a top view, so that the respective cantilever arm (9a, 9b) is spaced apart from the carrier (2) at its free end (11a, 11b) and its two longitudinal sides (19a-d).

5. MEMS sound transducer according to at least one of the preceding claims, characterized in that the recesses (13) are completely framed by the carrier (2).

6. MEMS sound transducer according to at least one of the preceding claims, characterized in that a single cantilever arm (9a, 9b) is arranged in each case in the recesses (13).

7. MEMS sound transducer according to at least one of the preceding claims, characterized in that the piezo element (5a, 5b) and the coupling element (8a, 8b) of the respective cantilever arm (9a, 9b) are formed in one piece from the material.

8. MEMS sound transducer according to at least one of the preceding claims, characterized in that the MEMS sound transducer (1) is a MEMS loudspeaker and / or a MEMS microphone.