METHOD FOR MANUFACTURING A CONVERTER UNIT

Description

[0001] The present invention relates to a method for producing a transducer unit, in particular a MEMS transducer unit, for converting electrical signals into deflections and / or deflections into electrical signals. At least one transducer element is arranged on a support element, and the transducer element is coupled to a membrane unit that can be deflected along a stroke axis. Furthermore, the invention relates to a transducer unit.

[0002] DE 603 ​​13 715 T2 discloses a method for manufacturing a converter unit. This is done by applying a sacrificial layer to a substrate. A membrane layer, a lower electrode layer, an active layer, and an upper electrode layer are then applied sequentially. The disadvantage of this method is that it is complex.

[0003] The article Just E et al: "A membrane actuator based on piezo-polymer-composite technology",TRANSDUCERS '05 : THE 13TH INTERNATIONAL CONFERENCE ON SOLID-STATE SENSORS, ACTUATORS AND MICROSYSTEMS ; SEOUL, KOREA, [JUNE 5 - 9, 2005] ; DIGEST OF TECHNICAL PAPERS, IEEE OPERATIONS CENTER, PISCATAWAY, NJ, Vol. 1, June 5, 2005 (2005-06-05), pages 753-756, DOI: 10.1109 / SENSOR.2005.1496526, ISBN: 978-0-7803-8994-6 describes a manufacturing process for a MEMS transducer unit in which a polymer membrane is molded onto a piezoelectric disk.

[0004] The object of the present invention is to provide a flexible manufacturing method for a converter unit.

[0005] The problem is solved by a method for producing a converter unit and a converter unit having the features of the independent patent claims.

[0006] A method is proposed for manufacturing a transducer unit for converting electrical signals into deflections and / or deflections into electrical signals. The transducer unit can be a MEMS transducer unit comprising a piezo actuator. In one application, the transducer unit can be used to generate and / or detect sound waves in the audible wavelength range and / or in the ultrasonic range. In this application, the electrical signals can be audio signals, which are converted into deflections, which in turn generate sound waves. The transducer unit can thus be a loudspeaker and / or a microphone. As a microphone, the transducer unit converts the deflections resulting from sound waves into the electrical signal or the audio signal. The transducer unit is a MEMS sound transducer.When sound waves are generated and / or detected in the ultrasonic range, they can be used, for example, in technical testing equipment or in ultrasound devices for sonography.

[0007] The transducer unit can additionally or alternatively be used as an actuator, whereby, for example, a pressure or a force is generated by the deflection. Furthermore, the transducer unit can also be used as a sensor when a process causes a deflection, for example, a pressure or a force, which is then converted into an electrical signal by the transducer unit.

[0008] In the method, at least one transducer element is arranged on a carrier element. The carrier element can, for example, be a carrier substrate. The at least one transducer element for generating and / or detecting the sound waves is thus arranged on the carrier element. The transducer element can convert the electrical signal or an electrical voltage into a deflection, so that, for example, the sound waves can be generated. However, the transducer element can also convert the deflections into the electrical signal or the electrical voltage, so that, for example, the sound waves can be detected. The carrier element can, for example, be a printed circuit board and / or comprise electrical lines for the transducer element.

[0009] Furthermore, the transducer element is coupled to a membrane unit that can be deflected along a stroke axis. By means of the coupling, the deflections between the membrane unit and the at least one transducer element can be exchanged. For example, to generate the sound waves, the transducer element can deflect the membrane unit according to an electrical signal or subject it to vibrations, so that the membrane unit also excites the air arranged above it to vibrate, thereby generating the sound waves. In contrast, the air vibrating due to the sound waves can also excite the membrane unit to vibrate, which in turn is transmitted to the transducer element. The transducer element converts the vibrations into an electrical signal, i.e., the audio signal.

[0010] According to the invention, to form at least one flexible membrane element, a flowable and curable membrane material is cast, at least in sections, onto a reinforcing element of the membrane unit coupled to the transducer element. The membrane element and the reinforcing element together form at least partially the membrane unit.

[0011] The membrane material can be a polymer, for example. Furthermore, the membrane material can be a silicone. The membrane material can be a thermoplastic, elastomer, or thermoset. Since the membrane element is flexible, it can be deflected together with the reinforcing element, so that the membrane unit can be deflected. The reinforcing element itself can be flexible, but has less flexibility than the at least one membrane element. The stiffness of the reinforcing element is higher than that of the membrane element. However, the reinforcing element can also be rigid. As a result, only the at least one membrane element bends or deforms when the membrane unit is deflected.

[0012] By casting the at least one membrane element onto the reinforcement element, the manufacturing process can be simplified. Furthermore, this creates a flexible manufacturing process, since the pourable membrane material allows for any shape of the transducer unit and / or reinforcement element to be accommodated. This eliminates the need for prior adaptation of the membrane unit to different shapes of the transducer unit.

[0013] The acoustic properties of the transducer unit also depend on the flexibility of the diaphragm element when it is used as a sound transducer. Less flexibility or greater stiffness, for example, dampens the acoustic properties. If, on the other hand, the transducer unit is used as a pressure sensor, for example, the flexibility of the diaphragm element can be used to define a pressure range in which the transducer unit can measure the pressure. It is clear that at high pressures, the diaphragm element must have less flexibility in order to be able to limit its own deflection. The flexibility can be selected using the diaphragm material or the composition of the diaphragm material. For example, for less flexibility, a diaphragm material is selected that has a higher elastic modulus after curing.Additionally or alternatively, a thickness of the at least one membrane element can be varied in order to adapt its flexibility or stiffness.

[0014] It is advantageous if the flowable and curable membrane material is cast onto the reinforcement element in such a way that the at least one flexible membrane element and / or the membrane unit is formed separately from the transducer element. Additionally or alternatively, the reinforcement element can also be arranged in such a way that the at least one flexible membrane element and / or the membrane unit is formed separately from the transducer element. By separating the at least one flexible membrane element and / or the membrane unit from the transducer element, the transducer unit can be constructed in a modular manner. In particular, after the membrane material has cured, the transducer element and the membrane unit are separated from one another or are only connected to one another via a coupling.

[0015] It is advantageous if the at least one transducer element is coupled to the at least one reinforcing element and the membrane element is subsequently cast onto it. This first creates a firm connection between the reinforcing element and the transducer element, and then the membrane element is arranged on the unit consisting of the transducer element and the reinforcing element.

[0016] It is advantageous if the at least one transducer element is arranged in a receiving space of a dam arrangement. The dam arrangement can be arranged first on the carrier element and then the transducer element. Alternatively, it is also possible for the transducer element to be arranged first and then the dam arrangement on the carrier element. The dam arrangement has the form of a frame on the carrier element with the receiving space. The flowable membrane material can be poured into the dam arrangement or the receiving space formed thereby. With the help of the dam arrangement, the flowable membrane material can be retained or retained in the region in which the at least one membrane element is to be formed.

[0017] If the transducer element is arranged in the receiving space, the dam arrangement completely surrounds the transducer element. Furthermore, the dam arrangement also completely surrounds the reinforcement element when it is coupled to the transducer element.

[0018] It is advantageous if the at least one membrane element is cast onto the reinforcing element in a transverse direction oriented transversely to the stroke axis. The reinforcing element has a circumferential side that extends transversely to the stroke axis around the reinforcing element. The at least one membrane element is thus cast onto the circumferential side of the reinforcing element. The circumferential side also faces the dam arrangement. When the membrane element is cast onto the reinforcing element in the transverse direction and thus formed, it enlarges the surface area of ​​the membrane unit, thereby increasing, for example, the acoustic performance of the transducer unit.

[0019] Additionally or alternatively, it is advantageous if the at least one membrane element is cast onto the dam assembly. Since the dam assembly is firmly connected to the carrier element, the membrane unit is anchored to the carrier substrate by means of the coupling of the membrane element to the dam assembly. The membrane unit can then vibrate or be deflected according to an audio signal to generate sound when the transducer unit is used as a loudspeaker. The membrane unit is thus clamped to the dam assembly via the membrane element. The membrane unit is attached to the dam assembly.

[0020] Additionally or alternatively, it is advantageous if the at least one membrane element is arranged between the reinforcement element and the dam arrangement. Since the dam arrangement can extend completely around the reinforcement element, the at least one membrane element can be arranged entirely in the region between the dam arrangement and the reinforcement element. The membrane unit can also form a closed surface with the dam arrangement if the at least one membrane element is arranged between the reinforcement element and the dam arrangement. Consequently, the membrane unit can apply pressure and / or vibrations to a surrounding medium, such as air, for generating and / or detecting sound.

[0021] It is advantageous if the membrane material is cast at least partially onto a first and / or second end face of the reinforcing element in the direction of the stroke axis, so that it is formed at least partially on the first and / or second end face of the reinforcing element. The membrane material can also be cast in an edge region of the first and / or second end face of the reinforcing element. The reinforcing element can, for example, have a thickness of only a few µm, for example 1 - 5 µm, in the direction of the stroke axis. The peripheral side is therefore correspondingly small, so that in order to improve the connection between the reinforcing element and the at least one membrane element, the first and / or second end face, for example in their edge regions, is cast with the membrane material. The reinforcing element is consequently enclosed by the at least one membrane element.The membrane element thus at least partially encompasses the reinforcement element. This improves the connection between the at least one membrane element and the reinforcement element.

[0022] Sections of the reinforcing element, in particular on the first and / or second end face, can further be roughened, for example by chemical processes, so that a positive connection can be formed between the reinforcing element and the membrane element.

[0023] It is advantageous if the dam assembly, the transducer element, and / or the reinforcement element are arranged relative to one another such that the reinforcement element is spaced apart from the dam assembly. As a result, the reinforcement element can be deflected contactlessly and / or freely relative to the dam assembly.

[0024] Furthermore, the at least one membrane element is arranged such that it is spaced apart from the transducer element. For this purpose, the membrane material is cast onto the reinforcement element such that the membrane element formed therefrom is spaced apart from the transducer element. As a result, the flexible membrane element is not hindered by the transducer element during deflection.

[0025] It is advantageous if the reinforcement element and / or the transducer element are arranged coaxially with the dam assembly. Additionally or alternatively, the reinforcement element and the transducer element can also be arranged coaxially with each other. This can improve the vibration properties of the membrane unit when the transducer unit is used, for example, as a sound transducer. The membrane unit can thus be deflected without, for example, tilting or without the orientation of the membrane unit changing during deflection.

[0026] It is advantageous if the dam assembly is glued to the carrier element. Additionally or alternatively, the dam assembly can also be formed integrally with the carrier element during its formation. Furthermore, a template can be placed on the carrier element, for example, which is filled with a dam material from which the dam assembly is formed. The dam material can also be a polymer, for example.

[0027] Furthermore, a coupling element is arranged between the transducer element and the reinforcement element. With the help of the coupling element, the transducer element can be coupled to the reinforcement element. The coupling element is arranged between the transducer element and the reinforcement element in order to space the transducer element from the reinforcement element. This ensures that even during maximum deflection of the membrane unit and thus of the reinforcement element, the reinforcement element or the membrane unit is still spaced from the transducer element. This prevents the membrane unit from striking the transducer element when deflected. The coupling element can also be formed as a single piece with the transducer element or the reinforcement element.Alternatively, the coupling element can also be connected first to the transducer element or the amplification element, and then to the corresponding counterpart, i.e. the amplification element or the transducer element.

[0028] It is advantageous if the membrane material for forming the at least one membrane element is cast into a membrane volume that borders the reinforcement element in a transverse direction oriented transversely to the stroke axis. The membrane volume is thus the volume in which the membrane element is to be formed.

[0029] Additionally or alternatively, the membrane volume can be arranged transversely between the reinforcement element and the dam arrangement.

[0030] It is advantageous if at least one filling volume in the receiving space is cast with a flowable and curable filling material. After curing, a filling element is thus formed in the receiving space. The filling material can be cast onto the reinforcement element, the transducer element and / or the dam arrangement. Additionally or alternatively, the filling element can also be cast onto the at least one, in particular cured, membrane element. The filling element is likewise flexible. Preferably, the filling element can be more flexible than the membrane element. With the help of the filling element, for example, the acoustic properties of the transducer unit can be changed and / or determined when the transducer unit is used as a sound transducer. The at least one filling volume borders on the membrane element and / or is spaced from it.

[0031] It is advantageous if the filler material is poured into the receiving space before and / or after the membrane material is cast onto the reinforcement element. For example, a filler material can be poured into the receiving space first, then the membrane material onto the reinforcement element, and then another filler material can be poured into the receiving space. As a result, the transducer unit can be manufactured step by step.

[0032] It is advantageous if at least one pouring opening is formed in the support element so that the membrane and / or filler material can be poured through the pouring opening. This allows the membrane and / or filler material to be poured into the receiving space.

[0033] It is advantageous if the membrane unit is arranged on an upper side of the transducer unit and the pouring opening is arranged on an underside, wherein the membrane and / or the filling material is poured in from the direction of the underside.

[0034] It is advantageous if the reinforcement element and / or the dam assembly are placed on an auxiliary element, and the membrane material and / or the filler material is poured in from the direction of the support element. The auxiliary element can, for example, be a plate, so that the plate closes the receiving space of the dam assembly. When the membrane material is poured in, it collects above the auxiliary element in the receiving space and, after curing, forms the at least one membrane element.

[0035] It is advantageous if the transducer unit is pivoted and / or vibrated during and / or after pouring the membrane and / or filler material. This distributes the membrane and / or filler material.

[0036] Additionally or alternatively, it is advantageous if the membrane and / or filler material is cast under pressure. This can accelerate production.

[0037] It is advantageous if the membrane material and the filling material are cured one after the other, especially with the introduction of heat.

[0038] Also proposed is a converter unit, in particular a MEMS converter unit, for converting deflections into electrical signals and / or electrical signals into deflections, preferably for generating and / or detecting sound waves in the audible wavelength range and / or in the ultrasonic range.

[0039] The transducer unit comprises a support element and at least one transducer element arranged on the support element. With the aid of the transducer element, the deflections can be converted into electrical signals and / or electrical signals into deflections. The transducer element can, for example, comprise a piezo actuator that can convert electrical signals into deflections and deflections into electrical signals.

[0040] The transducer unit further comprises a membrane unit coupled to the transducer element. The membrane unit can transmit the deflections to a surrounding medium, such as air, thereby generating sound. Additionally or alternatively, vibrations and / or pressure of the medium can also lead to the deflections of the membrane unit, which are transmitted to the transducer element, which then generates the electrical signal.

[0041] According to the invention, the membrane unit comprises a reinforcing element which is coupled to the transducer element and to which at least one flexible membrane element is cast at least in sections, so that the reinforcing element together with the membrane element at least partially form the membrane unit.

[0042] Furthermore, the converter unit can be designed according to one or more method features of the preceding and / or subsequent description. Additionally or alternatively, a method step for the preceding method can also be performed to form a converter unit that has at least one feature of the subsequent description.

[0043] It is advantageous if the transducer element and the membrane unit are arranged separately from each other. This means that the transducer element and the membrane unit are separate units, elements, or components. This allows the transducer unit to be constructed modularly.

[0044] Additionally or alternatively, it is advantageous if the transducer element and the membrane unit are arranged at a distance from one another. The transducer element and the at least one flexible membrane element are also spaced from one another. In addition, the transducer element and the reinforcement element can also be spaced from one another.

[0045] Additionally or alternatively, it is advantageous if the transducer element and the membrane unit are coupled to one another by means of a coupling element. Furthermore, the transducer element is coupled to the reinforcement element by means of the coupling element. Additionally or alternatively, the transducer element and the membrane unit, in particular the reinforcement element, can also be coupled to one another solely and / or exclusively by means of the coupling element. Consequently, the transmission of deflections between the transducer element and the membrane unit occurs solely via the coupling element.

[0046] It is advantageous if the transducer element is arranged on the support element by means of at least one base element, in particular by means of at least two base elements. This spaced the transducer element from the support element.

[0047] It is advantageous if a membrane and / or filler material has a modulus of elasticity of less than 10 MPa, in particular less than 1 MPa. Preferably, the modulus of elasticity of the membrane material is greater than that of the filler material.

[0048] It's also advantageous if the membrane material and the filler material are different. Alternatively, the membrane material and the filler material can be the same.

[0049] Further advantages of the invention are described in the following exemplary embodiments. They show: Figure 1 a schematic cross-section of a transducer unit with transducer element and membrane unit, Figure 2 a schematic cross-section of a transducer unit with transducer element and membrane unit on an auxiliary element, Figure 3 a schematic cross-section of a transducer unit with transducer element and membrane unit and Figure 4 a schematic cross-section of a transducer unit with transducer element and membrane unit.

[0050] Figure 1 shows a schematic cross-section of a transducer unit 1. The transducer unit 1 can convert electrical signals into deflections. This occurs, for example, when the transducer unit 1 is used as a loudspeaker or as an actuator. Additionally or alternatively, the transducer unit 1 can also convert deflections into electrical signals. This occurs, for example, when the transducer unit 1 is used as a microphone or sensor. The transducer unit 1 is a MEMS transducer unit. The deflections can be used, for example, to generate pressure or force.

[0051] The transducer unit 1 comprises a carrier element 2 on which at least one transducer element 3 is arranged. With the help of the transducer element 3, the deflections can be converted into electrical signals and / or the electrical signals into deflections. The transducer element 3 can thus be used, for example, to generate and / or detect sound waves. Furthermore, the transducer element 3 can be deflected in the direction of a stroke axis H in order to consequently generate the deflections and / or the electrical signals. The transducer element 3 can, for example, comprise a substrate and at least one piezo actuator. With the help of the piezo actuator, the electrical signals can be converted into deflections and / or the deflections can be converted into electrical signals. The piezo actuator can deflect or be deflected along the stroke axis H.

[0052] The transducer unit 1 also comprises a membrane unit 5, which is coupled to the at least one transducer element 3. By means of the membrane unit 5, for example, vibrations can be transmitted as deflections from the transducer element 3 to the surrounding air, so that sound is generated and the transducer unit 1 is thus operated as a loudspeaker. Additionally or alternatively, the membrane unit 5 can also be used to detect sound waves in vibrations as deflections, which are converted by the transducer element 3 into an electrical signal. The transducer unit 1 can thus be operated as a microphone. Of course, it is not important whether sound deflects the membrane unit 5. For example, the transducer unit 1 can also be a pressure or force sensor, so that a medium other than air deflects the membrane unit 5, whereby this deflection is converted by the transducer element 3 into an electrical signal.

[0053] The at least one transducer element 3 can be deflected along a stroke axis H.

[0054] The transducer element 3 can, for example, comprise at least one piezo element or piezo actuator, which generates an electrical voltage when deflected and deflects itself when an electrical voltage is applied.

[0055] However, the transducer unit 1 can also be another sensor and / or actuator. For example, the transducer unit 1 can be a pressure or force sensor that determines a pressure or force based on a deflection of the transducer element 3. As an actuator, the transducer unit 1 can also generate a pressure or force.

[0056] Furthermore, the converter unit 1 of the present embodiment has a dam arrangement 6, which, in particular together with the support element 2, defines a receiving space 7. Here, the converter element 3 and the reinforcement element 4 are arranged in the receiving space 7.

[0057] Furthermore, in the present embodiment, a coupling element 9 is arranged between the transducer element 3 and the reinforcement element 4. With the aid of the coupling element 9, the membrane unit 5 and / or the reinforcement element 4 are spaced apart from the transducer element 3, so that it can be prevented that the membrane unit 5 and / or the reinforcement element 4 strikes the transducer unit 3 when deflected. The coupling element 9 can also be formed integrally with the transducer element 3, the membrane unit 5 and / or the reinforcement element 4.

[0058] Furthermore, as shown here, the membrane unit 5 can be separated from the transducer element 3 or arranged separately. The membrane unit 5 and the transducer element 3 are arranged and / or formed separately from one another. The membrane unit 5 and the transducer element 3 are coupled to one another only by means of the coupling element 9. Due to the separate arrangement and / or formation of the membrane unit 5 and the transducer element 3, the transducer unit 1 has a modular design. The transducer unit 1 can therefore, for example, be assembled step by step. In the event that a component of the transducer unit 1 is damaged or incorrectly arranged and / or formed, this component can be removed or rearranged or formed anew.

[0059] The transducer unit 1 also has a top side 10 and a bottom side 11 opposite thereto, particularly in the direction of the stroke axis H. The membrane unit 5 is arranged on the top side 10. The support element 2 is arranged in the area of ​​the bottom side 11.

[0060] The reinforcing element 4 also has a first end face 15 and a second end face 16, wherein both end faces 15, 16 are spaced apart from one another in the direction of the stroke axis H. The first end face 15 faces the upper side 10. Furthermore, the first end face 15 forms part of the upper side 10. The first end face 15 also faces away from the transducer element 3. The second end face 16 faces the transducer element 3. Furthermore, the first end face 15 or the reinforcing element 4 is arranged such that the first end face 15 is flush with the dam arrangement 6. The first end face 15 is flush with a dam upper side 22.

[0061] The membrane unit 5 further comprises at least one flexible membrane element 14a, b, which is formed during the method for producing the transducer unit 1 by pouring flowable and curable membrane material onto the reinforcing element 4. The membrane unit 5 thus comprises the reinforcing element 4 and the at least one membrane element 14a, b.

[0062] By casting the membrane material onto the reinforcing element 4 to form the at least one membrane element 14a, b, almost any shape of the membrane unit 5 can be accommodated without having to manufacture the membrane element 14a, b beforehand. Furthermore, by casting the membrane material, tolerances during production are compensated. Furthermore, the acoustic properties of the transducer unit 1, when used as a sound transducer, can be adapted almost arbitrarily, for example, by casting less or more membrane material onto the reinforcing element 4, so that a thinner or thicker membrane element 14a, b is formed. Such a decision can be made during the manufacturing process. By casting the at least one membrane element 14a, b, the manufacturing process becomes more flexible.

[0063] The reinforcing element 4 further has a peripheral side 17, which forms a peripheral surface. The peripheral side 17 extends completely around the reinforcing element 4. The peripheral side 17 faces the dam arrangement 6. Here, the at least one membrane element 14a, b is cast at least partially onto the peripheral side 17. Furthermore, the at least one membrane element 14a, b extends between the reinforcing element 4, in particular the peripheral side 17, and the dam arrangement 6.

[0064] According to the present embodiment, two membrane elements 14a, b are shown. If the membrane element 14a, b extends completely around the reinforcement element 4, the membrane unit 5 comprises only one membrane element 14. The two membrane elements 14a, b shown here can thus be connected. The membrane element 14 can extend completely around the reinforcement element 4 if the reinforcement element 4 is completely spaced from the dam arrangement 6, i.e., has no contact with the dam arrangement 6.

[0065] The at least one membrane element 14a, b can, as shown here, be flush with the first and / or second end face 15, 16 of the reinforcing element 4.

[0066] According to the present embodiment, the reinforcement element 4 is arranged centrally between the dam arrangement 6. The at least one membrane element 14a, b is thus also symmetrical.

[0067] According to the present embodiment, the transducer unit 1 comprises at least one base element 12a, b, with which the transducer element 3 is arranged on the support element 2. With the aid of the at least one base element 12a, b, the transducer unit 3 can be spaced from the support element 2 so that the transducer unit 3 does not strike the support element 2 during deflection. Two base elements 12a, b are shown here.

[0068] According to the present embodiment, the support element 2 further comprises a through-opening 8. With the aid of the through-opening 8, the acoustics of the transducer unit 1 can be adapted or improved if the transducer unit 1 is a sound transducer. The through-opening 8 shown here is arranged on the underside 11. The through-opening 8 of the present embodiment is also arranged between the two base elements 12a, b. The through-opening 8 can also be formed during the manufacturing process.

[0069] The at least one transducer element 3 further has at least one recess 19a, b. Two recesses 19a, b are shown here, although this may also be a single recess 19, which, as shown here, extends around the coupling element 9. With the help of the recess 19a, b, the transducer element 3 can deflect or be deflected more effectively. The regions near the at least one recess 19a, b can form a desired bending region or a desired deflection region.

[0070] The transducer unit 1 also has a rear volume 20, which is arranged on the side of the transducer element 3 facing away from the membrane unit 5. The rear volume 20 can also partially encompass the through-opening 8. The acoustics can also be adjusted using the rear volume 20. The rear volume 20 can also be formed during the manufacturing process.

[0071] Figure 2shows the transducer unit 1 with sections for pouring at least the membrane material.

[0072] Furthermore, for the sake of simplicity, features and their effects that have already been described in the preceding figures will not be explained again. Furthermore, features that are identical or at least similar in effect to those in the preceding and / or subsequent figures have the same reference numerals. For example, for the sake of clarity, features may also be described in the following figures.

[0073] The converter unit 1 is shown here in a different or opposite orientation. In Figure 1 the top 10 was on top, whereas in Figure 2 the bottom 11 is at the top.

[0074] According to the present embodiment, the support element 2 has a pouring opening 18. The pouring opening 18 is located here on the underside 11. During the manufacturing process of the transducer unit 1, the latter can be rotated and / or oriented such that the underside 11 is facing upwards, allowing the flowable membrane material to be poured into the receiving space 7 through the pouring opening 18.

[0075] During the manufacturing process, the transducer unit 1 can be placed on an auxiliary element 23. The auxiliary element 23 is a plate or at least plate-shaped. The auxiliary element 23 can be used to delimit or seal the receiving space 7 at the top 10, so that the membrane material is filled into the receiving space 7 and retained there. The auxiliary element 23 is not shown hatched here.

[0076] According to the present embodiment, the converter unit 1, in particular the receiving space 7, has at least one membrane volume 13a, b, which is filled with the membrane material and in which, after curing, the at least one membrane element 14a, b (cf. Figure 1 ) is trained.

[0077] The membrane volume 13a, b is delimited here by the dam assembly 6, the reinforcement element 4, and the auxiliary element 23. The dam assembly 6 with the dam top side 22 and the reinforcement element 4 with the first end face 15 are in contact with the auxiliary element 23. The dam assembly 6 with the dam top side 22 and the reinforcement element 4 with the first end face 15 also lie flat on the auxiliary element 23. A contact surface between the auxiliary element 23 and the reinforcement element 4 and / or the dam assembly 6 is at least impermeable to the membrane material.

[0078] The membrane material can thus be poured into the receiving space 7 through the pouring opening 18 from the direction of the underside 11. The membrane volume 13a, b is located at the lowest point here, so that the membrane material flows into the membrane volume independently, i.e., due to gravity. After curing, at least one membrane element 14a, b is formed.

[0079] The receiving space 7 can also be further subdivided. In addition to the membrane volume, the transducer unit 1 or the receiving space 7 can have at least one filling volume 21 into which a filling material can be introduced.

[0080] The membrane material and the filling material can be filled in any order. For example, as in the Figure 2As shown in the embodiment shown, the membrane material must be filled first, since the membrane volume 13a, b is located in the lowest area (with respect to the flow direction determined by gravity). Once the membrane material has been filled, it can be cured, for example, by applying heat, so that the at least one membrane element 14a, b is formed.

[0081] The filling material can then be poured into the filling volume 21, for example also through the pouring opening 18.

[0082] According to the present embodiment, the receiving space 7 is divided into several filling volumes 21a - g in addition to the membrane volume 13a, b.

[0083] A first filling volume 21a is arranged here between the second membrane volume 13b and the support element 2 and borders the second membrane volume 13b. A second filling volume 21b is arranged between the first filling volume 21a and the support element 2 and borders both.

[0084] A third filling volume 21c is arranged between the reinforcement element 4 and the transducer element 3. A fourth filling volume 21d is also arranged between the reinforcement element 4 and the transducer element 3 and at least partially overlaps the recess 19b. A fifth filling volume 21e is also arranged between the reinforcement element 4 and the transducer element 3 and at least partially overlaps the recess 19a. A sixth filling volume 21f is arranged between the reinforcement element 4 and the transducer element 3.

[0085] A seventh filling volume 21g is arranged between the carrier element 2 and an eighth filling volume 21h, wherein the eighth filling volume 21h is adjacent to the membrane volume 13a.

[0086] The filling material for the various filling volumes 21 is, like the membrane material, also flowable and can be cured, for example by applying heat.

[0087] After the filling material has been filled, it is also cured, although this can be done gradually.

[0088] For example, the acoustic properties of the transducer unit 1 can be adjusted using the various filling volumes 21a-g filled with filler material when operated as a sound transducer. The filler material advantageously has a modulus of elasticity of less than 10 MPa, or preferably less than 1 MPa, when cured.

[0089] By adapting the acoustic properties of the transducer unit 1 using the cured filler material, other elements for adapting the acoustic properties can be dispensed with. For example, grids can be inserted into the receiving space 7 to adapt the acoustic properties, but these require complex manufacturing processes. If such grids have incorrect dimensions, they cannot be used. The filler material, on the other hand, can be filled in a single step and automatically adapts to the receiving space 7 or the corresponding filling volume 21.

[0090] Figure 3 shows the transducer unit 1 with a membrane unit 5.

[0091] Furthermore, for the sake of simplicity, features and their effects that have already been described in the preceding figures will not be explained again. Furthermore, features that are identical or at least similar in effect to those in the preceding and / or subsequent figures have the same reference numerals. For example, for the sake of clarity, features may also be described in the following figures.

[0092] According to the present embodiment, the at least one membrane element 14a, b extends at least partially over the second end face 16. This allows a connection between the reinforcing element 4 and the at least one membrane element 14a, b to be reinforced. Here, the at least one membrane element 14a, b completely covers the second end face 16.

[0093] Additionally or alternatively, the at least one membrane element 14a, b can also extend at least partially over the first end face 15. If the membrane element 14a, b extends at least partially over both end faces 15, 16, the membrane element 14a, b encompasses the reinforcing element 4, so that the connection between the reinforcing element 4 and the at least one membrane element 14a, b is reinforced.

[0094] During the manufacturing process, for example, enough membrane material is filled into the receiving space 7 until it at least partially covers the second end face 16 so that it can be cured.

[0095] The reinforcing element 4 further has at least one edge region 24a, b, which faces the dam arrangement 6. The reinforcing element 4 can also have only one edge region 24, which extends around the reinforcing element 4. The at least one membrane element 14a, b can also be arranged at least in the edge region 24a, b.

[0096] Figure 4 shows the transducer unit 1 with a membrane unit 5.

[0097] Furthermore, for the sake of simplicity, features and their effects that have already been described in the preceding figures will not be explained again. Furthermore, features that are identical or at least similar in effect to those in the preceding and / or subsequent figures have the same reference numerals. For example, for the sake of clarity, features may also be described in the following figures.

[0098] According to the present exemplary embodiment, the at least one membrane element 14a, b is also arranged at least partially on the first end face 15. The auxiliary element 23 has at least one recess 25a, b into which the membrane material can flow in order to form the membrane element 14a, b at least partially on the first end face 15 after curing. The shape of the recesses 25a, b can also be used to define the area of ​​the at least one membrane element 14a, b on the first end face 15. The membrane element 14a, b can, as shown here, be arranged at least in the edge region 24a, b of the reinforcing element on the first end face 15.

[0099] In an alternative embodiment, the at least one membrane element 14a, b can also be arranged only on the first end face 15. The membrane material is filled into the receiving space 7 until it is flush with the second end face 16.

[0100] The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the claims are possible. List of reference symbols

[0101] 1 Transducer unit 2 Support element 3 Transducer element 4 Reinforcement element 5 Membrane unit 6 Dam arrangement 7 Receiving space 8 Through opening 9 Coupling element 10 Top side 11 Bottom side 12 Foot element 13 Membrane volume 14 Membrane element 15 First end face 16 Second end face 17 Peripheral side 18 Pouring opening 19 Recess 20 Rear volume 21 Filling volume 22 Dam top side 23 Auxiliary element 24 Edge area 25 Recess HLifting axis ZCenter QTransverse direction ADistance

Claims

1. A method for manufacturing a MEMS transducer unit (1) for transducing electrical signals into deflections and / or deflections into electrical signals, in which a transducer element (3) is coupled to a diaphragm unit (5) which can be deflected along a reciprocation axis (H) and which is formed at least partially by a reinforcing element (4) and a flexible diaphragm element (14), wherein the at least one transducer element (3) is arranged on a support element (2), wherein a coupling element (9) is arranged between the transducer element (3) and the reinforcing element (4) and spaces the transducer element (3) from the reinforcing element (4), wherein, in order to form the at least one flexible diaphragm element (14), a flowable and curable diaphragm material is cast at least in sections onto the reinforcing element (4) coupled to the transducer element (3) in such a way that the diaphragm element (14) together with the reinforcing element (4) at least partially form the diaphragm unit (5) and the diaphragm element (14) is spaced from the transducer element (3).

2. The method according to the preceding claim, characterized in that the at least one transducer element (3) is coupled to the at least one reinforcing element (4) and the diaphragm element (14) is then cast on.

3. The method according to one or more of the preceding claims, characterized in that the at least one transducer element (3) is arranged in an accommodation space (7) of a dam arrangement (6) such that the transducer element (3) and the reinforcing element (4) are completely surrounded by the dam arrangement (6).

4. The method according to the preceding claim 3, characterized in that the at least one diaphragm element (14) is cast onto the dam arrangement (6) and / or the at least one diaphragm element (14) is arranged between the reinforcing element (4) and the dam arrangement (6).

5. The method according to one or more of the preceding claims, characterized in that the diaphragm element (14) is cast onto a circumferential side (17) of the reinforcing element (4).

6. The method according to one or more of the preceding claims 3 to 5, characterized in that the dam arrangement (6) and the reinforcing element (4) are arranged with respect to one another in such a way that the reinforcing element (4) is spaced from the dam arrangement (6).

7. The method according to one or more of the preceding claims 3 to 6, characterized in that, in order to form the at least one diaphragm element (14), the diaphragm material is cast into a diaphragm volume (13) which adjoins the reinforcing element (4) in a transverse direction oriented transversely with respect to the reciprocation axis (H).

8. The method according to one or more of the preceding claims, characterized in that at least one pouring opening (18) is formed in the support element (2) such that the diaphragm material can be cast in through the pouring opening (18).

9. The method according to one or more of the preceding claims, characterized in that the reinforcing element (4) is placed on an auxiliary element (23) and the diaphragm material is cast in from the direction of the support element (2).

10. A MEMS transducer unit (1) for transducing deflections into electrical signals and / or electrical signals into deflections, which is formed by means of a method according to one or more of the preceding claims, comprising a support element (2), at least one transducer element (3) arranged on the support element (2), and comprising a diaphragm unit (5) which is coupled to the transducer element (3) and which is formed at least partially by a reinforcing element (4) and a flexible diaphragm element (14), wherein a coupling element (9) is arranged between the transducer element (3) and the reinforcing element (4) and spaces the transducer element (3) from the reinforcing element (4), wherein the reinforcing element (4) is coupled to the transducer element (3), and wherein the flexible diaphragm element (14) made of a diaphragm material is cast on the reinforcing element (4) at least in sections in such a way that the reinforcing element (4) together with the diaphragm element (3) at least partially form the diaphragm unit (5) and the diaphragm element (14) is spaced from the transducer element (3).