Micromechanical member, acoustic transducer device and method for manufacturing a micromechanical member

Abstract

This invention relates to a micromechanical component for an acoustic transducer device. The micromechanical component includes a substrate, a diaphragm, at least one piezoelectric element, and at least one electrical connection. The diaphragm is configured in a vibratory manner and connected to the substrate. At least one piezoelectric element is disposed between the diaphragm and the substrate and connected to the diaphragm. The at least one piezoelectric element is configured to generate and / or detect vibrations of the diaphragm in the ultrasonic range. At least one electrical connection is electrically connected to at least one piezoelectric element. The micromechanical component can be connected to control circuitry using flip-chip technology such that at least one piezoelectric element can be electrically connected to the control circuitry via at least one electrical connection.

Description

Technical Field

[0001] This invention relates to a micromechanical component for an acoustic transducer device, an acoustic transducer device, and a method for manufacturing the micromechanical component for the acoustic transducer device. The micromechanical component can also be configured as a spatially resolved material detector, as an optical mirror, or as an interferometer. Background Technology

[0002] Ultrasonic transducers can be constructed as microelectromechanical systems (MEMS). This type of device, which emits and detects ultrasonic waves using the piezoelectric effect, is called a piezoelectric micromachined ultrasonic transducer (PMUT). An exemplary PMUT with low stress sensitivity is known from WO2016 / 106153A1.

[0003] The standout features of PMUTs are their compact construction and high resolution. Piezoelectric elements generate vibrations in the diaphragm and surrounding liquid, thereby emitting ultrasonic waves. These reflected ultrasonic waves are then detected using piezoelectric elements. Based on semiconductor manufacturing processes, multiple individual PMUTs can be easily and cost-effectively combined into an array on a single chip. By using arrays of this type of PMUT, environmental mapping can be achieved. Therefore, MEMS-PMUTs are particularly well-suited for imaging methods, such as in medical technology.

[0004] exist Figure 1 An exemplary configuration of an ultrasonic head 7 is shown, wherein an array of multiple PMUT units 3 is constructed. A thin diaphragm 1 is excited to vibrate via a piezoelectric layer 2, and the vibration is transmitted to a gel 8. An electrical signal is supplied to each individual PMUT unit 3, provided by a control chip or application-specific integrated circuit (ASIC) chip 5.

[0005] In a classic approach, two chips 4 and 5 are typically combined. An array with PMUT cells 3 is provided on the first MEMS chip 4. The second ASIC chip 5 is arranged next to the MEMS chip 4 on a common substrate.

[0006] Multiple electrical connections between MEMS chip 4 and ASIC chip 5 are established by bonding wires 6, which are placed on the edges of the two chips 4 and 5 respectively.

[0007] In this arrangement, electrical connections via bonding wires 6 can be implemented only on the edges of the MEMS chip 4 within the array. The length of the edge of the MEMS chip 4 is proportional to the diameter of the MEMS chip 4, and the number of possible PMUT3s on the MEMS chip 4 is proportional to the area of ​​the MEMS chip, i.e., the square of its diameter. Therefore, especially for large arrays, connecting the MEMS chip 4 becomes difficult.

[0008] Furthermore, for classic wire bonding technology, the ASIC chip 5 must be positioned as close as possible to the MEMS chip 4. Due to the parallel arrangement of the two chips 4 and 5, the ultrasonic head 7 becomes larger than technically necessary.

[0009] Additionally, the bonding wire 6 must be protected, while simultaneously emitting the ultrasonic signal of PMUT3 with as little interference as possible. This requires a complex construction. In this type of arrangement, the defined gelation process becomes difficult, where gel 8 is applied to membrane 1.

[0010] exist Figure 2 In the alternative shown, MEMS-PMUT3 is fabricated on the ASIC chip via additional steps on the completed ASIC wafer. A direct electrical connection is established between the ASIC chip and PMUT3 using suitable methods. Therefore, it is possible to fabricate very large PMUT arrays while simultaneously achieving a more cost-effective and smaller construction scheme.

[0011] In this approach, if the PMUT unit is to be placed on the ASIC chip, it imposes limitations on the manufacturing process of the PMUT unit 3. For example, a typical ASIC wafer cannot be heated above 400°C for an extended period. Therefore, it is difficult to manufacture a cost-effective and efficient PMUT. In particular, it is difficult to fabricate a piezoelectric layer with a high piezoelectric coefficient.

[0012] Furthermore, if an electrical connection is to be established between the PMUT and the ASIC, the ASIC manufacturing process must be matched. This reduces system flexibility. If a new ASIC process with advantages enters the market, it must first be matched before it can be used.

[0013] Furthermore, ASIC chips and MEMS chips must have the same size. If one of the chips is larger by default, the smaller type must be matched accordingly, resulting in additional costs. Summary of the Invention

[0014] The present invention provides a micromechanical component for an acoustic transducer device, an acoustic transducer device, and a method for manufacturing the micromechanical component for the acoustic transducer device, having the features of the independent claims.

[0015] The preferred embodiments are the subject of the corresponding dependent claims.

[0016] Therefore, according to a first aspect, the present invention relates to a micromechanical component for an acoustic transducer device. The micromechanical component includes a substrate, a diaphragm, at least one piezoelectric element, and at least one electrical connection. The diaphragm is configured in a vibratory manner and connected to the substrate. At least one piezoelectric element is disposed between the diaphragm and the substrate and connected to the diaphragm. The at least one piezoelectric element is configured to generate and / or detect vibrations of the diaphragm in the ultrasonic range. At least one electrical connection is electrically connected to at least one piezoelectric element. The micromechanical component can be connected to a control circuit using flip-chip technology such that at least one piezoelectric element can be electrically connected to the control circuit via at least one electrical connection. The term "capable of connection" should be understood herein as meaning that there exists at least one state in which the piezoelectric element is electrically connected to the control circuit via the electrical connection.

[0017] Therefore, according to a second aspect, the present invention relates to an acoustic transducer device having a micromechanical component according to the invention. Furthermore, the acoustic transducer device includes a control circuit. The micromechanical component is connected to the control circuit using flip-chip technology. At least one piezoelectric element of the micromechanical component is electrically connected to the control circuit via at least one electrical connection.

[0018] According to a third aspect, the present invention relates to a method for manufacturing a micromechanical component. A substrate is provided. A vibratory diaphragm is constructed and connected to the substrate. At least one piezoelectric element is provided, disposed between the diaphragm and the substrate and connected to the diaphragm. The at least one piezoelectric element is configured to generate and / or detect vibrations of the diaphragm in the ultrasonic range. At least one electrical connection is constructed, electrically connected to the at least one piezoelectric element. The micromechanical component can be connected to a control circuit using flip-chip technology such that the at least one piezoelectric element can be electrically connected to the control circuit via the at least one electrical connection. The term "capable of connection" is to be understood herein as meaning that there exists at least one state in which the piezoelectric element is electrically connected to the control circuit via the electrical connection.

[0019] Advantages of the present invention

[0020] According to the present invention, the piezoelectric element, i.e., the PMUT element, is coupled to a control circuit assembled using flip-chip technology via an electrical connection. This eliminates the need for a separate bonding wire for activating the piezoelectric element. This allows for activation particularly easily and cost-effectively.

[0021] By using flip-chip technology, the number of possible electrical connections between piezoelectric elements and control circuitry is proportional to the square of the diameter. Therefore, the number of piezoelectric elements (PMUTs) in the array can, in principle, be chosen to be arbitrarily large.

[0022] The electrical connection can be easily and reliably protected by being positioned below the piezoelectric element.

[0023] The piezoelectric element is also particularly well protected by being arranged on the back side of the diaphragm (i.e., the side of the diaphragm that is oriented toward the substrate).

[0024] Furthermore, it enables the simple construction of micromechanical components because the bonding wires between the piezoelectric element and the control circuit are not exposed and do not need to be protected in the construction.

[0025] By arranging micromechanical components and control circuits vertically and in a stacked manner, it is possible to achieve a structure that is particularly small in the horizontal direction.

[0026] Micromechanical components can also be configured as spatially resolved material detectors, optical mirrors, or interferometers.

[0027] The manufacturing of acoustic transducer devices using flip-chip assembly can also be performed particularly easily and cost-effectively.

[0028] Furthermore, the manufacturing processes for micromechanical components and control circuits are completely separated from each other, which involves not only the size of individual components but also process control. This, for example, allows piezoelectric elements to be manufactured at exceptionally high temperatures, thus enabling the production of piezoelectric elements with exceptionally high piezoelectric coefficients.

[0029] The "control circuit" can be understood as a circuit configured to control at least one piezoelectric element to thereby induce vibration of a diaphragm. Alternatively, the "control circuit" can also be understood as a circuit controlled by at least one piezoelectric element, i.e., the circuit receives a measurement signal. The at least one piezoelectric element converts the vibration of the diaphragm into an electrical measurement signal and transmits the electrical measurement signal to the control circuit via at least one electrical connection. The control circuit functions as an analysis and processing circuit, i.e., it can analyze and process the received measurement signal. When using an array of piezoelectric elements, the environment can be mapped, for example, based on the measurement signals received by multiple piezoelectric elements.

[0030] "Electrically connected connection" should be understood as a connection through which electrical signals can be transmitted, such as control signals from the control circuit to at least one piezoelectric element, or measurement signals from at least one piezoelectric element to the control circuit.

[0031] According to a preferred extension of the micromechanical component, the control circuit is an ASIC chip. The ASIC chip may include memory and computing devices, such as a microprocessor, and can be configured for further analysis and processing of measurement signals received from at least one piezoelectric element. The ASIC chip can also control at least one piezoelectric element via corresponding control signals to excite a diaphragm to vibrate.

[0032] According to a preferred extension scheme of the micromechanical component, at least one electrical connection includes a through-silicon via (TSV) that extends through the substrate.

[0033] According to a preferred extension scheme of the micromechanical component, the substrate is connected to the diaphragm and / or at least one piezoelectric element by means of bonding. Thus, the diaphragm and the substrate can be fabricated independently of each other first, and then connected by bonding method.

[0034] According to a preferred extension scheme of the micromechanical component, the bonding connection includes at least one of aluminum and germanium.

[0035] According to a preferred extension of the micromechanical component, an insulating circumferential trench is constructed in the substrate around at least one bonding connection. This electrically insulates the bonding connection, which is part of an electrically connected connection that connects at least one piezoelectric element to a control circuit.

[0036] According to a preferred extension scheme of the micromechanical component, an electrically insulating material is constructed on the surface of the substrate in the region of the insulating trench. This improves the electrical insulation.

[0037] According to a preferred extension of the micromechanical component, at least one electrical connection includes at least one solder ball. In particular, each piezoelectric element can have its own electrical connection with a corresponding solder ball. Through each solder ball, the control circuit can thereby connect exactly one piezoelectric element.

[0038] According to a preferred extension of the micromechanical component, at least one electrically connected connection is additionally or alternatively included on at least one first printed wire on the side of the substrate opposite to the film.

[0039] According to a preferred extension of the micromechanical component, at least one of the at least one piezoelectric element is electrically connected to at least one bonding connection via a second printed wire.

[0040] In particular, each piezoelectric element can be electrically connected to at least one bonding connection via a second printed wire.

[0041] According to a preferred extension of the micromechanical component, the electrical connection extends from the piezoelectric element via a second printed conductor to the bonding connection constituting the through-hole, and further extends via a first printed conductor to the solder ball.

[0042] According to a preferred extension scheme of the micromechanical component, the material of the second printed wire includes aluminum.

[0043] According to a preferred extension of the micromechanical component, at least one piezoelectric element is surrounded by a completely encircling bonding frame. This bonding frame connects the substrate and the diaphragm. This protects the piezoelectric element from environmental influences.

[0044] According to a preferred extension scheme of the micromechanical component, the substrate is a doped silicon substrate.

[0045] According to a preferred extension of the micromechanical component, the diaphragm is at least partially composed of silicon. The thickness of the diaphragm is preferably less than 30 micrometers. The diaphragm may be made thicker in certain areas, or may be equipped with one or more additional layers in certain areas. Preferably, the diaphragm layers are implemented in a completely sealed manner.

[0046] According to a preferred extension scheme of the micromechanical component, a groove is provided in the substrate on the side facing the film.

[0047] According to a preferred extension of the method for manufacturing micromechanical components, an etch stop layer is constructed on the surface of a carrier substrate to construct a vibrating diaphragm connected to the substrate. Furthermore, a diaphragm layer is constructed on the etch stop layer. The carrier substrate is at least partially removed, wherein this removal is at least partially performed by using an etching method. This allows the fabrication of a thin and uniform diaphragm.

[0048] According to a preferred extension of the method for fabricating micromechanical components, only a portion of the carrier substrate and etch stop layer are removed. The carrier substrate and etch stop layer are structured in the edge regions. This can, for example, simplify the subsequent gelation process.

[0049] According to a preferred extension of the method for manufacturing micromechanical components, the diaphragm is connected to the substrate by means of bonding.

[0050] According to a preferred extension of the method for manufacturing micromechanical components, for the bonding method, a layer comprising aluminum is used on the film side, and a layer comprising germanium is used on the substrate side.

[0051] According to a preferred extension of the method for manufacturing micromechanical components, an insulating trench is constructed around at least one bonded connection in the substrate.

[0052] According to a preferred extension of the method for manufacturing micromechanical components, an electrically insulating material is constructed on the surface of a substrate in the region of an insulating trench.

[0053] Furthermore, the present invention relates to a method for manufacturing an acoustic transducer device. For this purpose, a micromechanical component manufactured according to the above method is connected to a control circuit via flip-chip technology, such that at least one piezoelectric element of the micromechanical component is electrically connected to the control circuit via at least one electrical connection. Attached Figure Description

[0054] The attached diagram shows:

[0055] Figure 1 This illustrates an acoustic transducer device according to the prior art;

[0056] Figure 2 This illustrates an alternative acoustic transducer device based on the prior art;

[0057] Figure 3 An acoustic transducer device according to one embodiment of the invention is shown;

[0058] Figure 4 An acoustic transducer device according to another embodiment of the invention is shown;

[0059] Figures 5 to 19 A schematic illustration of intermediate products in a method for manufacturing micromechanical components according to one embodiment of the present invention;

[0060] Figure 20 A micromechanical component according to one embodiment of the invention is shown.

[0061] In all the accompanying drawings, identical or functionally equivalent elements and devices are given the same reference numerals. The numbering of method steps is for clarity and should generally not imply a definite temporal order. In particular, multiple method steps may be performed simultaneously. Detailed Implementation

[0062] Figure 3 An acoustic transducer device 200 with micromechanical components 100 is shown. The micromechanical components 100 include a substrate 20 preferably constructed of doped silicon, and a vibrating diaphragm 45 connected to the substrate 20.

[0063] The diaphragm 45 is preferably made of silicon and is preferably thinner than 30 mm. The diaphragm 45 may be made thicker in some areas or equipped with one or more additional layers in some areas. Preferably, the diaphragm 45 is implemented in a completely sealed manner.

[0064] A gel 8 is formed above the diaphragm 45. A piezoelectric element 47 is disposed between the diaphragm 45 and the substrate 20 and connected to the diaphragm 45. The piezoelectric elements 47 are arranged in an array and configured to generate and / or detect vibrations of the diaphragm 45 in the ultrasonic range. A through-hole 23 is provided in the substrate 20, the through-hole being connected to the piezoelectric element 47.

[0065] The micromechanical component 100 is connected to the ASIC chip 12 in the connection area 11 using a flip-chip method. The ASIC chip serves as a control circuit. The control circuit 12 can control the piezoelectric element 47 through the through-hole 23 and can receive the measurement signals from the piezoelectric element 47.

[0066] Figure 4 Another acoustic transducer device 300 is shown. Here, the carrier substrate 43 and the etch stop layer 44 are structured or configured into edge regions, such that the gel 8 is enclosed within them from the side edges. The suspension of the membrane 45 is achieved through the bonding region 60.

[0067] exist Figures 5 to 2 Figure 1 shows the method steps of a manufacturing method for manufacturing a micro-mechanical component 100.

[0068] like Figure 5 As shown, a substrate 20 is first provided, which is preferably made of doped silicon. Optionally, a pad layer 40 is applied and structured onto a first side (front side) of the substrate 20.

[0069] like Figure 6 As shown, a first component 41 of a bonding layer is applied and structured on a first side of the substrate 20. The first component 41 of the bonding layer is preferably at least partially composed of germanium.

[0070] like Figure 7 As shown, the cavity 42 may optionally be etched into the first side of the substrate 20. The etching of the cavity 42 may preferably and particularly cost-effectively be performed together with the etching of the first component 41 of the bonding layer.

[0071] like Figure 8 As shown, the etch stop layer 44 and the film layer 45 are constructed on a first side of the carrier substrate 43 (i.e., the second substrate), which faces the substrate 20 in the finished state. The carrier substrate 43 and the etch stop layer 44 are optional here. However, by using the carrier substrate 43 and the etch stop layer 44, a very thin and uniform film 45 can be produced.

[0072] At least one of the oxide layer, nitride layer and oxide nitride layer can be used as etch stop layer 44.

[0073] The film layer 45 is preferably made of silicon. Preferably, the thickness of the film layer 45 is between 1.5 and 30 micrometers.

[0074] like Figure 9 As shown, an insulating layer 46 is applied to the side (back side) of the film layer 45 facing the substrate 20 in the completed state.

[0075] like Figure 10 As shown, piezoelectric elements 47 are applied to the insulating layer 46. Here, the invention is not limited to a fixed number of piezoelectric elements 47. Preferably, a plurality of piezoelectric elements 47 are applied in an array arrangement.

[0076] The piezoelectric element 47 is composed of a lower electrode, a true piezoelectric material, and an upper electrode. Preferably, the piezoelectric material includes lead zirconate titanate (PZT) and / or potassium sodium niobate (KNN).

[0077] Alternatively, for better growth, an additional layer (e.g., LaNiO3) can be used between the lower electrode and the PZT layer. Alternatively, the piezoelectric element 47 can be encapsulated with a protective layer to protect it from environmental influences. Preferably, tantalum nitride and / or silicon nitride and / or aluminum oxide is used for the protective layer.

[0078] like Figure 11 As shown, a second component 48 of the bonding layer is further applied to and structured on the insulating layer 46. Preferably, the material of the second component 48 of the bonding layer includes aluminum.

[0079] Furthermore, printed conductors (conductive layers) 49 are applied and structured on the insulating layer 46. These printed conductors 49 are used to establish electrical connections between the various bonding surfaces described below and the electrodes of the piezoelectric element 47.

[0080] Preferably, the conductive layer 49 is made of aluminum. Preferably, the same layer serves as a second component 48 of the bonding layer and as a printed conductor 49 between the bonding surface and the electrode.

[0081] like Figure 12 As shown, a carrier substrate 43 having a layer thereon is bonded to a substrate 20 having a layer thereon. Here, a bonding connection (bonding surface) 21 is formed between the substrate 20 and the diaphragm 45 or a bonding connection (bonding surface) 25 is formed between the substrate 20 and the piezoelectric element 47. The bonding connection 21 between the substrate 20 and the diaphragm 45 forms a bonding frame, which preferably completely surrounds and thereby protects the piezoelectric element 47.

[0082] Preferably, a eutectic bonding method is used. In particular, a bonding method containing aluminum and germanium is preferred.

[0083] Preferably, the following bonding method is used: the maximum temperature of the bonding method is 400 to 470°C.

[0084] Optionally, the substrate 20 may be thinned from the second side (back side). Particularly preferably, the substrate 20 may be thinned to a thickness of 20 to 450 micrometers for this purpose.

[0085] like Figure 13 As shown, for substrate thicknesses between 40 and 450 micrometers, it is preferable to apply an auxiliary layer 51 that is at least partially insulating, which has very narrow access holes 52 or slits in the regions surrounding the respective bonded connections.

[0086] like Figure 14 As shown, insulating trenches 50 surrounding each bonded connection are slotted into the first substrate from the second side (back side) of the substrate 20, thereby forming vias 23. For a substrate 20 with a thickness between 20 and 100 micrometers, it is preferable to etch very narrow trenches, which are narrower than 8 micrometers in the opening region.

[0087] Furthermore, by employing a grooving process with large lateral over-etching, through-and-through trenches are created beneath the structured surrounding area.

[0088] like Figure 15 As shown, an insulating layer 53 is applied and structured onto the auxiliary layer 51. The insulating trench 50 previously formed in the first substrate is closed by this insulating layer 53.

[0089] Preferably, the insulating layer 53 is an oxide layer. Preferably, the insulating trench 50 is closed only on the back side, and closed cavities are retained in the insulating trench 50 within the substrate 20 itself.

[0090] like Figure 16 As shown, optionally, one or more printed conductors (conductive layers) 54 are deposited and structured.

[0091] like Figure 17 As shown, the insulating layer 56 can be additionally deposited and structured.

[0092] like Figure 18 As shown, solder balls 55 or solderable layers or solder bumps are deposited on printed conductors 54.

[0093] Printed conductor 49, bonding connection 25, through hole 23, printed conductor 54 and solder ball 55 form an electrical connection.

[0094] like Figure 19 As shown, the carrier substrate 43 is thinned from the first side (front side).

[0095] In a particularly simple variant, mechanical back-side thinning is first performed, followed by a plasma etching process or a wet etching process that stops at the etching stop layer 44.

[0096] like Figure 20 As shown, the etch stop layer 44 can optionally be removed subsequently as well. Therefore, a very precise defined thickness of the film 45 can be achieved very easily, despite a high amount of removal.

[0097] Figure 20 The micromechanical structural element 100 is shown in its completed state.

[0098] Alternatively, the carrier substrate 43 and etch stop layer 44 may be partially removed and structured, at least in the edge regions, for example, to obtain, as Figure 4 The structure is shown. Therefore, only a portion of the region is thinned, or the region is thinned to varying degrees. This allows for the construction of edge regions to achieve better gelatability and / or produce higher mechanical robustness.

[0099] From here, standard reprocessing of the micromechanical component 100 can be performed. The substrate 20 is separated, and the chip is soldered to the control circuit, such as an ASIC, using a flip-chip process.

[0100] exist Figure 20 The through-hole 23 (substrate perforation) shown is preferably not used to support the movable diaphragm 45. This sectioning is chosen solely to better illustrate the working principle of the contact perforation. Preferably, the suspension of the diaphragm 45 is substantially achieved through… Figure 4 This is achieved through the bonding region 60 shown, which is not separated from the substrate by an insulating trench. Therefore, a very robust suspension can be achieved. In this arrangement, the bonding region 25 with the surrounding insulating trench 50 is preferably positioned outside the active region of the film 45.

[0101] The present invention is not limited to the described embodiments. Therefore, an additional insulating layer can be further deposited and structured on the first side (front side) of the substrate 20. This additional insulating layer can be particularly disposed in the region where the insulating trench 50 is located. Thus, this insulating layer can serve as a trenching stop layer during the fabrication of the insulating trench. Then, etching gas cannot advance into the cavity where the piezoelectric element 47 is disposed and damage the piezoelectric element.

Claims

1. A micromechanical component (100) for an acoustic transducer device (200; 300), the micromechanical component having: a substrate (20); a vibratable diaphragm (45) connected with the substrate (20); at least one piezoelectric element (47) arranged between the diaphragm (45) and the substrate (20) and connected with the diaphragm (45), wherein, The at least one piezoelectric element (47) is configured to generate and / or detect vibrations of the diaphragm (45) in the ultrasonic range; at least one electrical access connection (23, 25, 30, 49, 55) which is electrically connected to the at least one piezoelectric element (47); wherein the micromechanical component (100) can be connected with the control circuit (12) in flip-chip technology such that the at least one piezoelectric element (47) can be electrically connected to the control circuit (12) via the at least one electrical access connection (23, 25, 30, 49, 55), characterized in that the substrate (20) is connected to the diaphragm (45) and / or the at least one piezoelectric element (47) by means of a bonding connection (21, 25) via a bonding region, wherein a circumferential insulation trench (50) is configured in the substrate (20) around the at least one bonding connection (21, 25).

2. The micromechanical component (100) according to claim 1, wherein The bonding connection (21, 25) comprises at least one of aluminum and germanium.

3. The micromechanical component (100) according to claim 1, wherein An electrically insulating material (28) is configured on the surface of the substrate (20) in the region of the insulation trench (50).

4. The micromechanical structure (100) according to any one of claims 1 to 3, wherein The at least one electrical access connection (23, 25, 30, 49, 55) comprises at least one of: at least one solder ball (55), and a first printed conductor (30) on the side of the substrate (20) facing away from the diaphragm (45).

5. The micromechanical structure (100) according to any one of claims 1 to 3, wherein The at least one piezoelectric element (47) is electrically connected to the at least one bonding connection (25) via a second printed conductor (49).

6. The micromechanical component (100) according to claim 5, wherein The material of the second printed conductor (49) comprises aluminum.

7. The micromechanical structure (100) according to any one of claims 1 to 3, wherein The at least one piezoelectric element (47) is surrounded by a completely circumferential bonding frame (21), wherein the bonding frame (21) connects the substrate (20) and the diaphragm (45).

8. An acoustic transducer device (200; 300) having a micromechanical structure (100) according to any one of the preceding claims; an operating circuit (12), wherein The micromechanical component (100) is connected with the control circuit (12) in flip-chip technology, and wherein the at least one piezoelectric element (47) of the micromechanical component (100) is electrically connected to the control circuit (12) via the at least one electrical access connection (23, 25, 30, 49, 55).

9. A method for manufacturing a micromechanical component (100), the method having the steps of: providing a substrate (20); constructing a vibratable membrane (45) connected to the substrate (20); providing at least one piezoelectric element (47) arranged between the membrane (45) and the substrate (20) and connected to the membrane (45), wherein, The at least one piezoelectric element (47) is configured to generate and / or detect oscillations of the diaphragm (45) in the ultrasonic range; at least one electrical connection (23, 25, 30, 49, 55) is configured, which is electrically connected to the at least one piezoelectric element (47); wherein the micromechanical component (100) can be connected with the operating circuit (12) in flip-chip technology in such a way that the at least one piezoelectric element (47) can be electrically connected to the operating circuit (12) via the at least one electrical connection (23, 25, 30, 49, 55), characterized in that the substrate (20) is connected to the diaphragm (45) and / or the at least one piezoelectric element (47) by means of a bonding connection (21, 25) via a bonding area, wherein a circumferential insulating trench (50) is configured in the substrate (20) around the at least one bonding connection (21, 25).

10. The method of claim 9, wherein, The configuration of the vibratable diaphragm (45) connected to the substrate (20) comprises the following steps: an etch stop layer (44) is configured on a surface of a carrier substrate (43); a diaphragm layer (45) is configured on the etch stop layer (44); the carrier substrate (43) is at least partially removed, at least partially using an etching method.

11. The method of claim 10, wherein, The carrier substrate (43) and the etch stop layer (44) are only partially removed and structured at least in the edge region.

12. The method of any one of claims 9-11, wherein, The diaphragm (45) is connected to the substrate (20) by means of a bonding connection (21, 25).

13. The method of claim 12, wherein, For the bonding method, a layer (48) comprising aluminum is used on the diaphragm side, and wherein a layer (41) comprising germanium is used on the substrate side.

14. The method of claim 13, wherein, An electrically insulating material (28) is configured on a surface of the substrate (20) in the region of the insulating trench (50).

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