EP3852391B1 - Haut-parleurs mems ayant une efficacité accrue - Google Patents

Haut-parleurs mems ayant une efficacité accrue Download PDF

Info

Publication number
EP3852391B1
EP3852391B1 EP20168836.3A EP20168836A EP3852391B1 EP 3852391 B1 EP3852391 B1 EP 3852391B1 EP 20168836 A EP20168836 A EP 20168836A EP 3852391 B1 EP3852391 B1 EP 3852391B1
Authority
EP
European Patent Office
Prior art keywords
layer
actuator
mems
electrode
vertical sections
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP20168836.3A
Other languages
German (de)
English (en)
Other versions
EP3852391A1 (fr
Inventor
Alfons Dehé
Achim Bittner
Lenny Castellanos
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hann-Schickard-Gesellschaft fuer Angewandte Forschung eV
Original Assignee
Hann-Schickard-Gesellschaft fuer Angewandte Forschung eV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hann-Schickard-Gesellschaft fuer Angewandte Forschung eV filed Critical Hann-Schickard-Gesellschaft fuer Angewandte Forschung eV
Priority to JP2022542931A priority Critical patent/JP2023511538A/ja
Priority to KR1020227027423A priority patent/KR20220130720A/ko
Priority to US17/758,923 priority patent/US11800294B2/en
Priority to CN202180016496.XA priority patent/CN115280797A/zh
Priority to PCT/EP2021/050766 priority patent/WO2021144400A1/fr
Priority to EP21700309.4A priority patent/EP4091340A1/fr
Publication of EP3852391A1 publication Critical patent/EP3852391A1/fr
Application granted granted Critical
Publication of EP3852391B1 publication Critical patent/EP3852391B1/fr
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H04R17/005—Piezoelectric transducers; Electrostrictive transducers using a piezoelectric polymer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/12—Non-planar diaphragms or cones
    • H04R7/14—Non-planar diaphragms or cones corrugated, pleated or ribbed
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H04R17/10—Resonant transducers, i.e. adapted to produce maximum output at a predetermined frequency
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • H04R31/003—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor for diaphragms or their outer suspension
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/12—Non-planar diaphragms or cones
    • H04R7/122—Non-planar diaphragms or cones comprising a plurality of sections or layers
    • H04R7/125—Non-planar diaphragms or cones comprising a plurality of sections or layers comprising a plurality of superposed layers in contact
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/003—Mems transducers or their use

Definitions

  • the invention relates to a MEMS transducer which comprises an oscillating membrane for generating or receiving pressure waves of a fluid in a vertical direction, wherein the oscillating membrane is held by a carrier and the oscillating membrane has two or more vertical sections which are formed parallel to the vertical direction and comprise at least one layer of an actuator material.
  • the oscillating membrane is preferably contacted at the end with an electrode, so that by controlling the at least one electrode the two or more vertical sections can be excited to horizontal oscillations or so that when the two or more vertical sections are excited to horizontal oscillations an electrical signal can be generated at the at least one electrode.
  • microsystem technology is now used in many areas of application to produce compact, mechanical-electronic devices.
  • the microsystems microelectromechanical systems , MEMS
  • MEMS microelectromechanical systems
  • MEMS transducers such as MEMS loudspeakers or MEMS microphones
  • MEMS loudspeakers are also known from the state of the art.
  • Current MEMS loudspeakers are usually designed as planar membrane systems with a vertical actuation of an oscillating membrane in the emission direction. The excitation takes place, for example, using piezoelectric, electromagnetic or electrostatic actuators.
  • the MEMS loudspeaker features a stiffening silicon microstructure as a sound radiator, with the moving part suspended from a support via silicon drive springs to enable large out-of-plane displacements using an electromagnetic motor.
  • the vibration membrane is not closed, but comprises eight piezoelectric unimorph actuators, each consisting of a piezoelectric and a passive layer.
  • the outer woofers consist of four trapezoidal actuators clamped on one side, while the inner tweeters are formed by four triangular actuators that are connected to a rigid frame by means of a spring. The separation of the membrane is intended to allow an improved sound image with higher performance.
  • planar MEMS loudspeakers are their limitation in terms of sound output, especially at low frequencies.
  • One reason for this is that the sound pressure level that can be generated is proportional to the square of the frequency for a given deflection.
  • deflections for the vibration membranes of at least 100 ⁇ m or large-area membranes in the square centimeter range are necessary. Both conditions are difficult to achieve using MEMS technology.
  • a MEMS loudspeaker based on this principle is used, for example, in the US 2018 / 0179048 A1 and Kaiser et al. 2019, respectively.
  • the MEMS loudspeaker comprises a plurality of electrostatic bending actuators, which are arranged as vertical lamellae between a cover and a base wafer and can be excited to lateral vibrations by appropriate control.
  • An inner lamella forms an actuator electrode opposite two outer lamellae. Except for a connecting node of electrodes that are still galvanically separated, there is an air gap between the three curved lamellae. If a potential is applied inside to outside, this leads to a bilateral attraction due to the curvature of the design in the direction of a preferred direction, which is specified by an anchor.
  • the bulges in the outer lamellae serve to facilitate mobility.
  • the restoring force is provided by a mechanical spring force. Pull-push operation is therefore not possible.
  • Another disadvantage is that gaps between the bending actuators and the top/bottom wafers, which are necessary for their mobility, lead to ventilation between the two chambers. This limits the lower limit frequency. Furthermore, the lateral movement of the bending actuators and thus the sound power is restricted in order to avoid a pull-in effect and acoustic breakdown.
  • the device comprises a front and rear chamber and a plurality of valves, wherein the front and rear chambers are separated from one another by means of a folded membrane.
  • the folded membrane has a rectangular meander structure with horizontal and vertical sections in cross section. Piezo actuators are positioned on the respective horizontal sections in order to cause a lateral movement of the vertical sections by a synchronized stretching or compression of the horizontal sections.
  • the disadvantage is the increased effort required for the synchronized drive of the piezo actuators.
  • a piezoelectric loudspeaker is known in which two piezoelectric films are formed into a diaphragm with an accordion shape.
  • the diaphragm is folded and clamped laterally by a wave-shaped pair of plates, which are fixed, for example, by means of screw connections and stabilize the vibrating diaphragm as a composite side frame.
  • Electrode lines are arranged in the plate pair or side frame to control the electrodes.
  • the plate pair can also be formed at least partially from a conductive material.
  • the macroscopic piezoelectric loudspeaker US 2002/006208 A1 and JP3 919695 B2 is obtained in an assembly process that cannot be miniaturized in an obvious way to obtain a MEMS loudspeaker.
  • the intended clamping of the diaphragm in a two-part side frame, the structured application of several electrodes on wave crests and troughs of the diaphragm or the connection of the electrodes with electrode lines in the side frame cannot be transferred to a MEMS process.
  • the object of the invention is to provide a MEMS converter, in particular a MEMS loudspeaker or MEMS microphone, as well as a method for producing the MEMS converter, which do not have the disadvantages of the prior art.
  • the design of the MEMS loudspeaker makes it possible to obtain a MEMS loudspeaker with high sound power and simplified control.
  • the vibrating membrane itself does not have to be operated over a large area of several square centimeters or with a deflection of more than 100 ⁇ m to generate sufficient sound pressure. Instead, the majority of the vertical sections of the vibrating membrane can move an increased total volume in the vertical emission direction with small horizontal or lateral movements of a few micrometers.
  • the claimed MEMS loudspeaker is characterized by a simplified structure, control and manufacturing process.
  • the vertical sections of the oscillating membrane can instead be obtained in MEMS design using simple manufacturing steps, as explained in more detail below.
  • the actuator principle according to the invention avoids pull-in or gluing of the vertical sections.
  • the one-sided electrodes do not result in any potential differences in a gap between the vertical sections.
  • this can also reduce dust accumulation, since, for example, an external electrode can be set to a ground potential.
  • MEMS loudspeaker Another special advantage of the MEMS loudspeaker described is the simplified control. While in the US 2019 / 011 64 17 A1 a large number of piezoelectric actuators must be contacted at the horizontal sections, the proposed MEMS loudspeaker can be operated using at least one end electrode. This reduces the manufacturing effort, minimizes sources of error and also inherently leads to a synchronous control of the vertical sections to horizontal vibrations.
  • a "MEMS loudspeaker” preferably refers to a loudspeaker which is based on MEMS technology and whose sound-generating structures at least partially have dimensions in the micrometer range (1 ⁇ m to 1000 ⁇ m).
  • the vertical sections of the vibratable membrane can have a dimension in the range of less than 1000 ⁇ m in terms of width, height and/or thickness. It can also be preferred that, for example, only the height of the vertical sections are dimensioned in the micrometer range, while, for example, the length can have a larger dimension and/or the thickness can have a smaller size.
  • the design of the vibrating membrane can be used advantageously not only to create a MEMS loudspeaker with high sound output and simplified control, but also to provide a particularly powerful MEMS microphone with high audio quality.
  • the structure of the MEMS microphone is structurally similar to that of the MEMS loudspeaker, particularly with regard to the design of the vibrating membrane.
  • the MEMS microphone is designed to record sound pressure waves in the same vertical direction.
  • there are therefore air volumes between the vertical sections which are moved along a vertical detection direction when sound waves are recorded.
  • the sound pressure waves excite the vertical sections to horizontal vibrations, so that the actuator material generates a corresponding periodic electrical signal.
  • a "MEMS microphone” preferably refers to a microphone that is based on MEMS technology and whose sound-recording structures at least partially have dimensions in the micrometer range (1 ⁇ m to 1000 ⁇ m).
  • the vertical sections of the vibratable membrane can have a dimension in the range of less than 1000 ⁇ m in terms of width, height and/or thickness. It can also be preferred that, for example, only the height of the vertical sections are dimensioned in the micrometer range, while, for example, the length can have a larger dimension and/or the thickness can have a smaller size.
  • MEMS converter therefore refers to both a MEMS microphone and a MEMS loudspeaker.
  • a MEMS converter is a converter for interacting with a volume flow of a fluid that is based on MEMS technology and whose structures for interacting with the volume flow or for absorbing or generating pressure waves of the fluid have dimensions in the micrometer range (1 ⁇ m to 1000 ⁇ m).
  • the fluid can be either a gaseous or a liquid fluid.
  • the structures of the MEMS converter, in particular the vibrating membrane, are designed to generate or absorb pressure waves of the fluid.
  • the MEMS converter can be sound pressure waves.
  • the MEMS converter can also be suitable as an actuator or sensor for other pressure waves.
  • the MEMS converter is therefore preferably a device that converts pressure waves (e.g. acoustic signals as alternating sound pressures) into electrical signals or vice versa (conversion of electrical signals into pressure waves, e.g. acoustic signals).
  • the MEMS converter as an energy harvester are also possible, using pneumatic or hydraulic alternating pressures.
  • the electrical signal can be dissipated as generated electrical energy, stored or fed to other (consumer) devices.
  • End preferably means a positioning of the at least one electrode so that contact can be made with electronics, e.g. with a current or voltage source in the case of a MEMS loudspeaker, at one end of the vibratable membrane, preferably at an end at which the membrane is suspended from the carrier.
  • Electrode preferably means an area made of a conductive material (preferably a metal) which is set up for such contact with electronics, e.g. with a current and/or voltage source in the case of a MEMS loudspeaker. It can preferably be an electrode pad.
  • the electrode pad is particularly preferably used for contacting electronics and is itself connected to a conductive metal layer which can extend over the entire surface of the vibratable membrane.
  • the conductive layer together with an electrode pad is referred to below as an electrode, for example as a top electrode or bottom electrode.
  • the MEMS converter comprises two end electrodes.
  • the contact with electronics e.g. a current or voltage source, can be made with the electrodes at opposite ends of the vibratable membrane, between which the two or more vertical sections are present, so that the actuator position(s) in the vertical sections can be controlled by means of the end electrodes.
  • the end-side provision of the electrodes is therefore preferably distinguished from a contact which controls the respective vertical sections with respective separate electrodes or, in the case of a MEMS microphone, picks up electrical signals generated.
  • the MEMS converter therefore preferably comprises exactly one or exactly two electrodes for end-side contact and no further electrodes (pads) for contacting central vertical sections.
  • the layer of actuator material in the vertical sections serves as a component of a mechanical biomorph, wherein a lateral curvature of the vertical sections is caused by controlling the actuator layer via the electrode or wherein a corresponding electrical signal is generated by an induced lateral curvature.
  • the two or more vertical sections have at least two layers, wherein one layer comprises an actuator material and a second layer comprises a mechanical support material, and wherein at least the layer comprises the actuator material and is contacted with an end electrode, so that the horizontal vibrations can be generated by a change in shape of the actuator material relative to the mechanical support material.
  • the mechanical bimorph is formed by a layer of actuator material (e.g. a piezoelectric material) and a passive layer, which acts as a mechanical support layer. Both a transverse and a longitudinal piezo effect can be used for the bending.
  • the actuator layer When the actuator layer is activated, it can, for example, experience a transverse or longitudinal stretching or compression. This creates a stress gradient in relation to the mechanical support layer, which leads to a lateral curvature or vibration. As shown in the Fig.1 As illustrated, by alternating polarity at the electrodes, a push-pull operation can preferably be achieved, whereby almost the entire air volume can be moved alternately between the vertical sections in the vertical emission direction.
  • the advantage of the actuator principle is a highly efficient translation of the horizontal vibrations of vertical sections into a vertical volume movement or sound generation.
  • the actuator principle is not based on electrostatic attraction, but on a relative change in shape (e.g. compression, stretching, shearing) of the actuator layer compared to a support layer, sticking of the membrane sections can be ruled out. Instead, the vertical sections can finally touch each other and are therefore not restricted in their deflection.
  • the two or more vertical sections comprise at least two layers, wherein both layers comprise an actuator material and are contacted with electrodes at each end, and the horizontal vibrations can be generated by a change in shape of one layer relative to the other layer.
  • the horizontal vibration of the vertical sections is therefore not generated by a stress gradient between an active actuator layer and a passive support layer, but by a relative change in shape of two active actuator layers.
  • the actuator layers can consist of the same actuator material and be controlled differently.
  • the actuator layers can also consist of different actuator materials, for example piezoelectric materials with different deformation coefficients.
  • the "layer comprising an actuator material” is preferably also referred to as an actuator layer.
  • An actuator material preferably means a material which, when an electrical voltage is applied, changes shape, for example stretches. undergoes compression or shearing or, conversely, generates an electrical voltage under deformation.
  • the actuator material can be a piezoelectric material, a polymer piezoelectrical material and/or electroactive polymers (EAP).
  • EAP electroactive polymers
  • the piezoelectric material is selected from a group comprising lead zirconate titanate (PZT), aluminum nitride (AIN) and zinc oxide (ZnO).
  • PZT lead zirconate titanate
  • AIN aluminum nitride
  • ZnO zinc oxide
  • Polymer piezoelectric materials preferably include polymers that have internal dipoles and thus piezoelectric properties. This means that when an external electrical voltage is applied, the piezoelectric polymer materials (analogous to the aforementioned classic piezoelectric materials) undergo a change in shape (e.g. compression, stretching or shearing).
  • An example of a preferred piezoelectric polymer material is polyvinylidene fluoride.
  • a polymer piezoelectrical material layer is applied to a mechanical support layer and wound over an upper and lower comb.
  • a polymer piezoelectrical material layer including electrode
  • a support layer possibly including a counter electrode
  • An upper and lower comb preferably a MEMS structure
  • the "layer comprising a mechanical support material” is preferably also referred to as a support layer or support layer.
  • the mechanical support material or the support layer preferably serves as a passive layer which can withstand a change in the shape of the actuator layer.
  • the mechanical support material preferably does not change its shape when an electrical voltage is applied.
  • the mechanical support material is preferably electrically conductive, so that it can also be used directly for contacting the actuator layer. However, in some embodiments it can also be non-conductive and, for example, coated with an electrically conductive layer.
  • the mechanical support material is particularly preferably monocrystalline silicon, a polysilicon or a doped polysilicon.
  • the actuator layer undergoes a change in shape when an electrical voltage is applied, the position of the mechanical support material remains essentially unchanged.
  • the resulting stress gradient between the two layers preferably causes a horizontal curvature.
  • the thickness of the support layer in comparison to the thickness of the actuator layer should preferably be selected so that a sufficiently large stress gradient is generated for the curvature.
  • doped polysilicon as mechanical support material and
  • a piezoelectric material such as PZT or AIN, essentially equal thicknesses, preferably between 0.5 ⁇ m and 2 ⁇ m, have proven to be particularly suitable.
  • the piezoelectric material can preferably have a C-axis orientation perpendicular to the surface of the vertical sections, so that a transverse piezoelectric effect is used.
  • Other orientations and, for example, the use of a longitudinal piezoelectric effect to form the horizontal curvatures or vibrations may be preferred.
  • the vibratable membrane therefore comprises at least one layer of a conductive material.
  • the conductive material is selected from a group comprising platinum, tungsten, (doped) tin oxide, monocrystalline silicon, polysilicon, molybdenum, titanium, tantalum, titanium-tungsten alloy, metal silicide, aluminum, graphite and copper.
  • the direction specifications vertical and horizontal (or lateral) preferably refer to a preferred direction in which the vibratable membrane is aligned to generate or record pressure waves of the fluid.
  • the vibratable membrane is suspended horizontally between at least two side regions of a support, while the vertical direction (interaction direction with the fluid) for generating or recording pressure waves is orthogonal to it.
  • the vertical (interaction) direction corresponds to the vertical sound emission direction of the MEMS loudspeaker.
  • vertical preferably means the direction of sound emission
  • horizontal means a direction orthogonal to this.
  • the vertical (interaction) direction corresponds to the vertical sound detection direction of the MEMS microphone.
  • vertical preferably means the direction of sound detection or recording, while horizontal means a direction orthogonal to this.
  • the vertical sections of the vibratable membrane thus preferably refer to sections of the vibratable membrane which are aligned in the emission direction of a MEMS loudspeaker or the detection direction of a MEMS microphone.
  • the vibrating membrane is preferably aligned horizontally to the sound emission direction or sound detection direction, the sound waves are generated by actuating the vertical sections or vice versa detected.
  • the carrier comprises two side regions between which the vibratable membrane is arranged in a horizontal direction.
  • the carrier is preferably a frame structure which is essentially formed by a continuous outer border in the form of side walls of a free flat area.
  • the frame structure is preferably stable and rigid.
  • the individual side areas which preferably essentially form the frame structure are called side walls in particular.
  • the oscillating membrane is preferably held by at least two side walls of the carrier.
  • the two side walls can be seen in cross-section.
  • the support comprises four side areas, with additional end faces usually parallel to the drawn cross-section. These two additional side walls span the frame structure.
  • the oscillating membrane is preferably suspended flat within the free surface.
  • the flat spread of the oscillating membrane characterizes a horizontal direction, while the vertical sections are orthogonal to this.
  • the membrane can be attached to these side walls or slit there for greater mobility.
  • the slit can advantageously represent a dynamic high-pass filter, which, for example, couples a front volume and a rear volume with one another.
  • the carrier is formed from a substrate, preferably selected from the group consisting of monocrystalline silicon, polysilicon, silicon dioxide, silicon carbide, silicon germanium, silicon nitride, nitride, germanium, carbon, gallium arsenide, gallium nitride, indium phosphide and glass.
  • the carrier structure can be manufactured flexibly due to the materials and/or manufacturing methods.
  • the MEMS converter comprising an oscillating membrane together with a carrier is manufactured in a semiconductor process, preferably on a wafer. This further simplifies and reduces the cost of production, so that a compact and robust MEMS converter can be provided cost-effectively.
  • the oscillating membrane is formed by a lamellar structure or meander structure.
  • the specification of a lamellar or meander structure refers to the shape of the oscillating membrane in cross section.
  • a lamellar structure preferably refers to an arrangement of similar, parallel layers, which preferably form the vertical sections.
  • the individual lamellae are preferably arranged with their surface parallel to the vertical direction, preferably an emission or Detection direction.
  • the lamellae are constructed in multiple layers and form a mechanical biomorph.
  • the lamellae can each comprise an actuator layer and a passive layer made of a support material and/or two differently controllable actuator layers.
  • the lamellae are flat, which means in particular that their extension in each of the two dimensions (height, width) of their surface is greater than in a dimension perpendicular to this (the thickness).
  • size ratios of at least 2:1, preferably at least 5:1, 10:1 or more may be preferred.
  • the vibratable membrane preferably has a plurality of lamellae which form the vertical sections. For example, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50 or more lamellae may be preferred. This achieves a high level of efficiency for a desired sound emission or sound detection in a very small space.
  • the vibrating membrane is preferably formed by the lamellae as vertical sections, which are connected to one another via conductive bridges or horizontal sections.
  • Metal bridges for example, are suitable as bridges (cf. Fig.9 ) or bridges made of other conductive materials.
  • the conductive bridges ensure the mechanical integrity of the oscillating membrane.
  • the conductive bridges advantageously allow all lamellae to be contacted using electrodes at the end. The lamellae can thus be excited synchronously with horizontal vibrations or detect them with little control and manufacturing effort.
  • a meander structure preferably refers to a structure formed from a sequence of mutually orthogonal sections in cross-section.
  • the mutually orthogonal sections are preferably vertical and horizontal sections of the vibratable membrane.
  • the meander structure is particularly preferably rectangular in cross-section.
  • the meander structure thus preferably corresponds to a membrane folded along the width.
  • a vibratable membrane can therefore preferably also be referred to as a bellows.
  • the parallel folds of the bellows preferably form the vertical sections.
  • the connecting sections between the folds preferably form the horizontal sections.
  • the vertical sections are preferably longer than the horizontal sections, for example by a factor of 1.5, 2, 3, 4 or more.
  • the vertical sections are decisive, analogous to the lamellae described above.
  • the vertical sections are preferably constructed in multiple layers and form a mechanical biomorph.
  • the vertical sections can each comprise an actuator layer and a passive layer made of a support material and/or two differently controllable actuator layers.
  • the horizontal sections of the folded membrane can preferably be constructed identically to the vertical sections (cf. among others Fig. 3-7 ). However, it may also be preferred that the horizontal sections - in contrast to the vertical sections - do not have an actuator layer, but only a mechanical support layer and/or an electrically conductive layer.
  • the at least one layer of actuator material of the oscillatable membrane is a continuous layer.
  • Continuous preferably means that there is no interruption in the cross-sectional profile. Accordingly, in the embodiment mentioned, it is preferred that there is a continuous layer of actuator material in both the vertical and horizontal sections.
  • a continuous layer is particularly easy to manufacture and ensures synchronous actuation when operating a MEMS loudspeaker.
  • the performance of the MEMS transducer can be significantly determined by the number and/or dimensions of the vertical sections.
  • the vibratable membrane comprises more than 3, 4, 5, 10, 15, 20, 30, 40, 50, 100 or more vertical sections.
  • the vibratable membrane comprises less than 10,000, 5,000, 2,000, or 1,000 or fewer vertical sections.
  • the preferred number of vertical sections results in high sound power on the smallest chip surfaces without compromising the sound image or audio quality.
  • the vertical sections are flat, which means in particular that their extension in each of the two dimensions (height, width) of their surface is greater than in a dimension perpendicular thereto (the thickness).
  • size ratios of at least 2:1, preferably at least 5:1, 10:1 or more may be preferred.
  • the height of the vertical sections preferably corresponds to the dimension along the direction of sound emission or sound detection, while the thickness of the vertical sections preferably corresponds to the sum of the layer thickness of the one or more layers that form the vertical sections.
  • the length of the vertical sections preferably corresponds to a dimension orthogonal to the height or thickness. In the cross-sectional views of the figures below, height and thickness are shown schematically (not necessarily to scale), while the dimension of the length corresponds to a (non-visible) drawing depth of the figures.
  • the height of the vertical sections is between 1 ⁇ m and 1000 ⁇ m, preferably between 10 ⁇ m and 500 ⁇ m.
  • Intermediate ranges from the aforementioned ranges can also be preferred, such as 1 ⁇ m to 10 ⁇ m, 10 ⁇ m to 50 ⁇ m, 50 ⁇ m to 100 ⁇ m, 100 ⁇ m to 200 ⁇ m, 200 ⁇ m to 300 ⁇ m, 300 ⁇ m to 400 ⁇ m, 400 ⁇ m to 500 ⁇ m, 600 ⁇ m to 700 ⁇ m, 700 ⁇ m to 800 ⁇ m, 800 ⁇ m to 900 ⁇ m or even 900 ⁇ m to 1000 ⁇ m.
  • the aforementioned range limits can also be combined to obtain further preferred ranges, such as 10 ⁇ m to 200 ⁇ m, 50 ⁇ m to 300 ⁇ m or even 100 ⁇ m to 600 ⁇ m.
  • the thickness of the vertical sections is between 100 nm and 10 ⁇ m, preferably between 500 nm and 5 ⁇ m.
  • Intermediate ranges from the aforementioned ranges can also be preferred, such as 100 nm to 500 nm, 500 nm up to 1 ⁇ m, 1 ⁇ m to 1.5 ⁇ m, 1.5 ⁇ m to 2 ⁇ m, 2 ⁇ m to 3 ⁇ m, 3 ⁇ m to 4 ⁇ m, 4 ⁇ m to 5 ⁇ m, 5 ⁇ m to 6 ⁇ m, 6 ⁇ m to 7 ⁇ m, 7 ⁇ m to 8 ⁇ m, 8 ⁇ m to 9 ⁇ m or even 9 ⁇ m to 10 ⁇ m.
  • the aforementioned range limits can also be combined to obtain further preferred ranges, such as 500 nm to 3 ⁇ m, 1 ⁇ m to 5 ⁇ m or even 1500 nm to 6 ⁇ m.
  • the length of the vertical sections is between 10 ⁇ m and 10 mm, preferably between 100 ⁇ m and 1 mm.
  • Intermediate ranges from the aforementioned ranges can also be preferred, such as 10 ⁇ m to 100 ⁇ m, 100 ⁇ m to 200 ⁇ m, 200 ⁇ m to 300 ⁇ m, 300 ⁇ m to 400 ⁇ m, 400 ⁇ m to 500 ⁇ m, 500 ⁇ m to 1000 ⁇ m, 1 mm to 2 mm, 3 mm to 4 mm, 4 mm to 5 mm, 5 mm to 8 mm or even 8 mm to 10 mm.
  • the aforementioned range limits can also be combined to obtain further preferred ranges, such as 10 ⁇ m to 500 ⁇ m, 500 ⁇ m to 5 ⁇ m or even 1 mm to 5 mm.
  • a particularly compact MEMS transducer in particular MEMS loudspeaker or MEMS microphone, can be provided, which simultaneously combines high performance with excellent sound or audio quality.
  • the oscillatable membrane is formed by a meander structure with alternating vertical and horizontal sections, with holding structures attached to at least two of the horizontal sections, which are directly or indirectly connected to the carrier.
  • the holding structures can be provided, for example, by substrate material of the carrier, ie the holding structures can be formed directly from the substrate of a bottom wafer .
  • the holding structures it is also possible for the holding structures to be connected to the horizontal sections as separate ridges or elevations of a top wafer .
  • the support structures can preferably be attached to one and/or two sides of the vibratable membrane, i.e. preferably to upper and/or lower horizontal sections.
  • the use of support structures advantageously allows stabilization without negatively affecting sound generation or sound absorption.
  • the vibratable membrane therefore comprises at least one layer of a conductive material.
  • the conductive material is selected from a group comprising platinum, tungsten, (doped) tin oxide, monocrystalline silicon, polysilicon, molybdenum, titanium, tantalum, titanium-tungsten alloy, metal silicide, aluminum, graphite and copper.
  • the vibratable membrane comprises three layers, wherein an upper layer is formed from a conductive material and is connected to an upper electrode, a middle layer is formed from the actuator material and a lower layer is formed from a conductive material.
  • the conductive material of the upper and/or lower layer can be a mechanical support material, so that this layer has a dual function.
  • the layer ensures contact between the actuator layer and an electrical potential that can be applied to the end electrodes.
  • it functions as a mechanical support layer in the manner described to generate horizontal curvatures or vibrations when the actuator layer is actuated accordingly.
  • the vibratable membrane has a meander structure with a continuous upper layer made of a conductive material (metal), a continuous middle layer made of an actuator material and a lower layer made of a conductive mechanical support material.
  • a reverse order of the layers or a further additional conductive layer in contact with the mechanical support layer and/or actuator layer for improved contacting can also be provided.
  • the oscillatable membrane comprises two layers of an actuator material, which are separated by a middle layer of a conductive material, preferably metal, wherein the middle layer is connected to a first electrode and at least one of the two layers of an actuator material is contacted with a second electrode via a further layer of a conductive material, preferably a metal.
  • two actuator layers can also be used, for example to cause the vertical sections to vibrate horizontally by means of different controls.
  • two or more intermediate layers made of a conductive material can preferably be provided.
  • the layers made of conductive material for example made of a metal, preferably serve exclusively for contacting and not as a mechanical support layer. The voltage required for curvature or vibration in the sense of a bimorph for a MEMS loudspeaker is induced by a different control of the actuator layers themselves.
  • the layers made of a conductive material, such as metal can therefore be made particularly thin (less than 500 nm, preferably less than 200 nm).
  • FIG.5 One such preferred embodiment is shown as an example.
  • This has an oscillating membrane as a meander structure with two layers of an actuator material, which are separated by a middle layer of a conductive material (metal).
  • the middle layer is connected to a first end electrode pad, while the upper actuator layer is in contact with a second end electrode via a further layer of a conductive material.
  • a lower layer of a conductive material is not in contact with any of the electrodes.
  • a reverse order of the layers or omission of the lower layer of conductive material, which is not in contact with the electrodes, can also be provided.
  • the actuator layer(s) and, if applicable, the mechanical support layers are continuous, i.e. in cross-section they extend from one end of the membrane (at which a first electrode is preferably present) over several alternating horizontal and vertical sections to a second end of the membrane (at which a second electrode is preferably present).
  • the inventors recognized that for the operating principle of the MEMS transducer, preferably a MEMS loudspeaker, the provision of a mechanical biomorph in the vertical sections is sufficient.
  • the at least one actuator layer is not continuous, but is only present in the vertical sections, but not in the horizontal sections.
  • a mechanical support layer if present, runs continuously, or not runs continuously and is only provided in vertical sections, for example.
  • a preferred manufacturing process for an embodiment with a non-continuous actuator layer is described in the Figure 7 illustrated.
  • a targeted spacer etching of the actuator layer can be carried out in horizontal sections, so that only the vertical sections of the membrane have a layer of an actuator material.
  • a continuous layer of a mechanical support material can also be dielectric in order to avoid a short circuit between an upper and lower conductive layer (also known as top and bottom electrode).
  • the design is characterized by a particularly effective actuation and high performance, in which only the vertical sections are specifically stimulated to alternately arch or oscillate, while the horizontal sections remain mechanically neutral.
  • the displaced volume per phase of the actuation can advantageously be increased again.
  • a vibratable membrane in meander shape is preferably obtained by applying or etching correspondingly functional layers.
  • a vibrating membrane can also be manufactured by providing vertical sections and connecting them using metal bridges.
  • the vertical sections of the vibratable membrane comprise two layers, wherein a first layer consists of an actuator material, a second layer consists of a conductive support material and wherein the vertical sections are connected via horizontal metal bridges.
  • piezoceramic elements comprising a layer of a mechanical support material and a layer of a piezoelectric material, as well as a sacrificial layer, can preferably be provided for this purpose.
  • process steps comprising through-plating and metal filling as well as stacking and dicing of the piezoceramic elements, a membrane with high efficiency can advantageously be obtained in a robust and process-efficient manner.
  • the oscillating membrane is coated with a layer of a non-stick material.
  • Non-stick materials are particularly materials with low surface energies, which are largely inert to the environment and thus prevent the deposition of dust or other undesirable particles.
  • the non-stick materials can be formed by carbon layers, e.g. diamond-like carbon (DLC) layers or layers comprising perfluorocarbons (PFC), such as polytetrafluoroethylene (PTFT).
  • DLC diamond-like carbon
  • PFC perfluorocarbons
  • PTFT polytetrafluoroethylene
  • the MEMS converter preferably a MEMS loudspeaker, comprises a control unit which is configured to control the at least one electrode so that the two or more vertical sections are excited to horizontal oscillations.
  • the control unit is configured to control the electrodes, which ensures a frequency of the horizontal oscillations between 10 Hz and 20 kHz.
  • the MEMS transducer preferably a MEMS microphone
  • the MEMS transducer comprises a control unit which is configured to detect an electrical signal provided by the at least one electrode, which was generated by horizontal vibrations of the two or more vertical sections.
  • the control unit of a MEMS microphone is preferably configured to receive and process an electrical signal which corresponds to a frequency of the horizontal vibrations between 10 Hz and 20 kHz and is thus set up for sound detection in the audible range.
  • the control unit is therefore preferably configured and set up to use electrical signals to control the vibrating membrane (or the actuator position(s) in the vertical sections) to horizontal vibrations and a sound emission in the audible frequency range or to record and process a corresponding electrical signal when the vibrating membrane is excited.
  • control unit may preferably comprise a data processing unit.
  • a data processing unit preferably refers to a unit which is suitable and configured for receiving, sending, storing and/or processing data, preferably with regard to controlling the electrodes or receiving an electrical signal provided at the electrodes.
  • the data processing unit preferably comprises an integrated circuit, for example also an application-specific integrated circuit, a processor, a processor chip, microprocessor or microcontroller for processing data, and optionally a data memory, a random access memory (RAM), a read-only memory (ROM) or also a flash memory for storing the data.
  • control unit is integrated on a circuit board or circuit board alongside other components of the MEMS converter (carrier, oscillating membrane).
  • the MEMS converter is preferably seamlessly integrated with the electronics required for control or detection.
  • other electronic components such as a communication interface (preferably wireless, e.g. Bluetooth), an amplifier, a filter or a sensor can also be installed on one and the same circuit board.
  • a compact overall solution is obtained in which a MEMS converter, preferably a MEMS loudspeaker or MEMS microphone, can be provided together with the desired electronics in a very small space and preferably with cost-effective CMOS processing suitable for mass production.
  • CMOS processing suitable for mass production.
  • the vibratable membrane held by the carrier is arranged in a front side of a housing which encloses a rear resonance volume.
  • the sound emission of such a MEMS loudspeaker thus preferably occurs towards the open front side ( sound port ), whereby the sound image is improved, particularly for lower frequencies, by the rear resonance volume.
  • a ventilation opening in the housing to avoid acoustic short circuits and/or to support the sound image.
  • the ventilation opening is preferably small compared to the sound port and can, for example, have a maximum dimension of less than 100 ⁇ m, preferably less than 50 ⁇ m.
  • the described manufacturing method serves to provide a MEMS transducer with a folded oscillatable membrane with a meander structure. Examples of preferred manufacturing steps are described in the Fig. 2A-G or Fig. 8A-J described.
  • a substrate can be used as a substrate.
  • a blank such as a wafer, can be brought into the desired basic shape of the meander structure.
  • the layers for the vibrating membrane are preferably applied.
  • Applying at least one layer of a conductive material preferably includes applying a plurality of layers and in particular a layer system in addition to applying one layer.
  • a layer system comprises at least two layers applied in a planned manner to one another. Applying a layer or a layer system preferably serves to define the oscillatable membrane comprising vertical sections which can be excited to horizontal oscillations.
  • the application can preferably be selected from the group comprising physical vapor deposition (PVD), in particular thermal evaporation, laser beam evaporation, arc evaporation, molecular beam epitaxy, sputtering, chemical vapor deposition (CVD) and/or atomic layer deposition (ALD).
  • PVD physical vapor deposition
  • CVD chemical vapor deposition
  • ALD atomic layer deposition
  • the application can comprise, for example, deposition, e.g. in the case of a substrate made of polysilicon.
  • Etching and/or structuring can preferably be selected from the group comprising dry etching, wet chemical etching and/or plasma etching, in particular reactive ion etching, reactive ion deep etching (Bosch process).
  • suitable material such as copper, gold and/or platinum can also be deposited using common processes.
  • PVD Physical vapor deposition
  • CVD chemical vapor deposition
  • electrochemical deposition are preferably used for this.
  • the process steps can be used to provide a finely structured vibratable membrane with a desired definition of vertical and horizontal sections, which is preferably suspended between two side areas of a stable support and has dimensions in the micrometer range.
  • the manufacturing steps are standard process steps in semiconductor processing, so they have proven themselves and are also suitable for mass production.
  • the described manufacturing method serves to provide a MEMS transducer with an oscillatable membrane with a lamella structure, wherein the lamellae are mechanical bimorphs and are connected by metal bridges. Examples of unclaimed manufacturing steps are given in the Fig. 9 A-F illustrated.
  • piezoceramic elements can advantageously be used to obtain an oscillating membrane with lamellae as vertical sections, which are connected to each other by metal bridges, by means of a definition of holes, metal filling as well as stacking and dicing.
  • Piezoceramics are preferably ceramic materials that show a charge separation when deformed by an external force or that undergo a change in shape when an electrical voltage is applied.
  • the piezoceramic elements preferably comprise a piezoelectric layer and a layer made of a mechanical support material, as described above, as well as a sacrificial layer.
  • the sacrificial layer is used to process and provide the metal bridges and will not itself be part of the vibrating membrane.
  • the sacrificial layer can be a photoresist or photo lacquer, for example. These materials change their solubility when exposed to light, particularly UV light. In particular, it can be a so-called positive lacquer, the solubility of which increases when exposed to UV light. This allows the sacrificial layer to be removed in a targeted manner after a metal filling to provide the metal bridges.
  • Figure 1 illustrates a preferred embodiment of a MEMS loudspeaker according to the invention.
  • Fig. 1 A shows a resting state
  • Fig. 1B Two phases during the actuation of the MEMS loudspeaker are illustrated.
  • the MEMS loudspeaker comprises a vibrating membrane 1 for generating sound waves in a vertical emission direction, wherein the vibrating membrane 1 is held in a horizontal position by a carrier 4.
  • the vibrating membrane 1 has a meandering structure in cross section with horizontal 3 and vertical sections 2.
  • the vertical sections are formed parallel to the emission direction and have at least one actuator layer, for example a layer made of a piezoelectric material.
  • the vibrating membrane 1 and the actuator layer are contacted by means of electrodes at the end.
  • an electrode pad (not shown) can also be located on the carrier 4 , for example.
  • the vertical sections are preferably mechanical bimorphs which can be excited to horizontal vibrations by suitable controls.
  • the vertical sections 2 can comprise, for example, a first layer of an actuator material and a second layer of a mechanical support material. By controlling the actuator layer, a stress gradient and thus a curvature or vibration can be generated. It can also be preferred that the vertical sections 2 comprise two actuator layers which are controlled in opposite directions in order to cause a curvature of the vertical sections 2 by a corresponding relative change in shape.
  • Figure 1B illustrates two phases during an actuation as an example.
  • the majority of the vertical sections 2 of the vibrating membrane 1 can move an increased total volume in the vertical emission direction with small horizontal movements (curvature) of a few micrometers and thus be used to generate sound.
  • the actuation allows a particularly efficient implementation, since during one phase almost the entire air volume between the vertical sections can be moved up or down along the emission direction.
  • Figure 2 shows schematically a preferred manufacturing method for providing a MEMS loudspeaker with an oscillating membrane 1 which has a meandering shape in cross section.
  • An oscillating membrane with a meandering shape in cross section can also preferably be referred to as a folded membrane or bellows.
  • Fig. 2A shows an etching of the substrate 8 from a top or front side to form a structure.
  • parallel deep trenches (pockets) are etched into the substrate 8.
  • the molded structure represents a bellows or, in cross section, a meander.
  • etch stop 9 ( Fig. 2B ), which can be TEOS or PECVD , for example.
  • a layer of a mechanical support material 10 ( Fig. 2C ) and a layer of an actuator material 11 is applied.
  • the mechanical support material 10 can be doped polysilicon, for example, while a piezoelectric material can be used for the actuator material 10 , for example. Layer thicknesses of 1 ⁇ m, for example, can be preferred.
  • the piezoelectric material can preferably have a C-axis orientation perpendicular to the surface, so that a transverse piezoelectric effect is used. Other orientations and, for example, the use of a longitudinal effect can also be preferred.
  • Fig. 2E shows the preferred application of a full-surface top electrode as a layer of a conductive material 12 . End contact can be made, for example, by means of an electrode pad 13 ( Fig. 2 F) .
  • Fig. 2F and 2G illustrate a further etching of the substrate 8 from the back or bottom side, and the removal of the etch stop.
  • the manufacturing steps 2A-G thus produce an oscillating membrane 1 which has a meandering structure in cross section.
  • a continuous actuator layer 11 and the provision of end-side contacts 13 allow efficient actuation of the vertical sections 2 to produce horizontal oscillations (cf. Fig.1 ).
  • control is preferably carried out by means of two electrodes, so the actuator layer 12 is preferably contacted both from a front side (top electrode, conductive layer 12) and from a rear side (bottom electrode, via conductive mechanical support material 10) (cf. Fig. 6A ).
  • holding structures 14 can be provided. As shown in the Fig. 3 and 4 shown, these can preferably support horizontal sections 3 of the vibrating membrane 1.
  • the horizontal sections 3 are advantageously mechanically neutral (cf. Fig 1B ), so that no undesirable stresses are induced between the membrane 1 and the support structure 14 or carrier 4 during actuation.
  • Fig.5 illustrates a preferred alternative embodiment of a MEMS loudspeaker, wherein the vibratable membrane 1 comprises two actuator layers, which are separated by a middle layer made of a conductive material 12 , preferably metal.
  • the middle layer is connected to a first end-side electrode pad 13 , while in the embodiment shown the upper actuator layer 11 is contacted with a second end electrode pad 13 via a further layer made of a conductive material 12 .
  • Fig.6 illustrates preferred controls for operating the described MEMS loudspeakers.
  • a preferred control for a MEMS loudspeaker with an actuator layer 11 and a passive mechanical support layer 10 is shown.
  • the control is preferably carried out by means of two end-side electrode pads 13 , so that the horizontal vibrations can be generated by a change in the shape of the actuator material compared to the mechanical support material.
  • the actuator layer 11 is preferably contacted both from a front side (top electrode 13 , conductive layer 10) and from a rear side (bottom electrode 13 , conductive mechanical support material 10) .
  • An alternating voltage as an audio input signal can be applied, for example, to the front electrode pad 13 (left), while the rear electrode pad 13 (right) is grounded.
  • a preferred control for a MEMS loudspeaker with two actuator layers 11 is shown, which are separated by a middle layer made of a conductive material 12 , preferably metal.
  • An upper actuator layer 11 is preferably controlled from a front side (top electrode 13 and upper conductive layer 12) and the middle conductive layer 12.
  • a lower actuator layer 11 is preferably controlled from a rear side (bottom electrode 13 and lower conductive layer 12) and the middle conductive layer 12.
  • an alternating voltage can be applied as an audio input signal, for example, to the top and bottom electrode pads 13 (left), while the middle layer 12 is grounded via another electrode pad 13 (right).
  • Fig.7 shows, by way of example, a preferred integration of a MEMS loudspeaker according to the invention in a housing 15.
  • the vibrating membrane 1 held by the carrier 4 is arranged in a front side or front of a housing ( sound port ).
  • the housing also encloses a rear resonance volume ( back volume 16 ).
  • a ventilation opening 17 can be introduced to avoid acoustic short circuits or to support the sound image.
  • Fig.8 illustrates an alternative manufacturing process for providing a MEMS loudspeaker with an oscillating membrane 1 according to the invention.
  • Figures 8A-D The process steps shown are analogous to the Fig. 2 .
  • Fig. 8A shows an etching of the substrate 8 from a top or front side to form a structure, preferably a meander structure.
  • a structure preferably a meander structure.
  • parallel deep trenches are etched into the substrate 8.
  • the molded structure represents a bellows or a meander in cross section.
  • etch stop 9 ( Fig. 2B ), which can be TEOS or PECVD , for example.
  • a layer of a mechanical support material 10 ( Fig. 2C ) and an actuator material 11.
  • the mechanical support material 10 can be, for example, doped polysilicon, while a piezoelectric material is preferably used for the actuator material 12 .
  • the actuator layer 11 is not contacted as a continuous layer with an upper conductive layer. Instead, a spacer etching is carried out ( Fig. 8F ) of the actuator layer 11 in the horizontal sections of the membrane, so that only the vertical sections of the membrane have a layer of an actuator material 11 .
  • a continuous dielectric layer 18 is preferably applied to avoid a short circuit between the upper and lower electrodes to be applied later ( Fig. 8G ).
  • a continuous conductive layer as top electrode 12 allows front-side contact ( Fig. 8H ).
  • Fig. 8 I and 8 J illustrate a further etching of the substrate 8 from the back or bottom side and optionally the application of a continuous conductive layer 12 as a back side electrode.
  • Fig.9 illustrates an unclaimed manufacturing method for providing a MEMS loudspeaker with an oscillating membrane based on individual piezoceramics.
  • piezoceramic elements 19 comprising a layer of a mechanical support material 10 (e.g. doped polysilicon) and a layer of a piezoelectric material 11 as well as a sacrificial layer 20 (cf. Fig. 9A and 9B
  • the sacrificial layer 20 can, for example, be a photoresist.
  • the stacked piezoceramic elements 19 are introduced into a carrier 4 , wherein preferably the first and last piezoceramic elements are each contacted with an electrode 13 ( Fig. 9G ).
  • a vibratable membrane 1 is also obtained between a carrier 4 , which comprises at least two or more vertical sections 2 for generating sound waves in a vertical emission direction, which are formed parallel to the emission direction and can be excited to horizontal vibrations.
  • the actuator principle is preferably based on a relative change in shape of the actuator layer 11 compared to the mechanical support layer 10.
  • a continuous actuator layer is not necessary for this. Contacting of all vertical sections 2 by means of end-side control is ensured by the metal bridges 23 .

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Manufacturing & Machinery (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)
  • Measuring Fluid Pressure (AREA)
  • Micromachines (AREA)

Claims (13)

  1. Convertisseur MEMS pour l'interaction avec un flux volumique d'un fluide comprenant
    - un support (4),
    - une membrane oscillante (1) pour générer ou recevoir des ondes de pression du fluide dans une direction verticale, dans lequel la membrane oscillante (1) est maintenue par le support (4), dans lequel la membrane oscillante (1) est produite avec le support (4) dans un processus semi-conducteur, et dans lequel
    la membrane oscillante (1) présente deux sections verticales (2) ou plus, lesquelles sont formées parallèlement à la direction verticale et comprennent au moins une couche constituée d'un matériau d'actionnement (11), dans lequel la membrane oscillante (1) est en contact avec au moins une électrode (13) du côté de l'extrémité,
    de sorte que, par l'activation de l'au moins une électrode (13), les deux sections verticales (2) ou plus peuvent être excitées par des oscillations horizontales ou de sorte que, lorsque les deux sections verticales (2) ou plus sont excitées par des oscillations horizontales, un signal électrique est généré au niveau de l'au moins une électrode.
  2. Convertisseur MEMS selon la revendication précédente
    caractérisé en ce que
    le transducteur MEMS est un haut-parleur MEMS, dans lequel, de préférence, des volumes d'air (5) sont présents entre les sections verticales (2), lesquels volumes sont déplacés par les vibrations horizontales pour générer des ondes sonores le long d'une direction d'émission verticale, ou le transducteur MEMS est un microphone MEMS, dans lequel, de préférence, des volumes d'air (5) sont présents entre les sections verticales (2), lesquels volumes sont déplacés le long d'une direction de détection verticale lorsque des ondes sonores sont enregistrées.
  3. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    les deux sections verticales (2) ou plus comprennent au moins deux couches, dans lequel une couche (11) comprend un matériau d'actionneur et une seconde couche (10) comprend un matériau de support mécanique, dans lequel au moins la couche (11) comprenant le matériau d'actionneur est en contact avec une électrode (13),
    de sorte que des vibrations horizontales peuvent être générées par un changement de forme du matériau d'actionneur par rapport au matériau de support mécanique ou
    de sorte que des vibrations horizontales entraînent un changement de forme du matériau d'actionneur par rapport au matériau de support mécanique et génèrent un signal électrique.
  4. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    les deux sections verticales (2) ou plus comprennent au moins deux couches, dans lequel les deux couches (11) comprennent un matériau d'actionnement et sont chacune en contact avec une électrode (13) et
    les vibrations horizontales peuvent être générées par un changement de forme d'une couche par rapport à l'autre couche ou
    les vibrations horizontales conduisent à un changement de forme d'une couche par rapport à l'autre couche et génèrent un signal électrique.
  5. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    le support (4) comprend deux zones latérales entre lesquelles la membrane oscillante (1) est disposée dans le sens horizontal
    et/ou
    le support (4) est formé à partir d'un substrat (8), de préférence choisi dans le groupe constitué du silicium monocristallin, du polysilicium, du dioxyde de silicium, du carbure de silicium, du silicium-germanium, du nitrure de silicium, du nitrure, du germanium, du carbone, de l'arséniure de gallium, du nitrure de gallium, du phosphure d'indium et du verre.
  6. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    la membrane oscillante (1) est formée par une structure lamellaire ou une structure en méandre.
  7. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    la membrane oscillante (1) est formée par une structure en méandre avec des sections verticales (2) et horizontales (3) alternées, dans lequel des structures de maintien (14) sont fixées à au moins deux des sections horizontales (3), lesquelles structures sont reliées directement ou indirectement au support (4).
  8. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    le matériau d'actionneur comprend un matériau piézoélectrique, un matériau piézoélectrique polymère et/ou des polymères électroactifs (EAP), dans lequel le matériau piézoélectrique est de préférence choisi dans un groupe comprenant le titanate de zirconate de plomb (PZT), le nitrure d'aluminium (AIN) et l'oxyde de zinc (ZnO).
  9. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    la membrane oscillante (1) comprend trois couches, dans lequel une couche supérieure (12) est formée par un matériau conducteur, une couche intermédiaire (11) est formée par un matériau d'actionnement et une couche inférieure (12) est formée par un matériau conducteur, dans lequel le matériau conducteur de la couche supérieure et/ou inférieure est de préférence un matériau de support mécanique.
  10. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    la membrane oscillante (1) comprend deux couches (11) en un matériau d'actionnement, lesquelles sont séparées par une couche intermédiaire (12) en un matériau conducteur, de préférence du métal, dans lequel la couche intermédiaire (12) est reliée à une première électrode (13) et au moins l'une des deux couches (11) en un matériau d'actionnement est en contact avec une seconde électrode (13) par l'intermédiaire d'une autre couche (12) en un matériau conducteur, de préférence un métal.
  11. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    la membrane oscillante (1) est recouverte d'une couche de matériau antiadhésif.
  12. Convertisseur MEMS selon l'une des revendications précédentes
    caractérisé en ce que
    la membrane oscillante (1) maintenue par le support (4) est disposée dans un côté avant d'un boîtier (15), lequel renferme un volume de résonance arrière (16), dans lequel une ouverture de ventilation (17) est de préférence présente dans le boîtier (15) pour éviter les courts-circuits acoustiques et/ou pour favoriser l'image sonore.
  13. Procédé de fabrication d'un convertisseur MEMS selon l'une des revendications précédentes, comprenant les étapes suivantes :
    - la gravure d'un substrat (8), de préférence par une face avant, pour former une structure, de préférence une structure en méandre
    - l'application facultative d'une butée de gravure
    - l'application d'au moins deux couches, dans lequel au moins une première couche (11) comprend un matériau d'actionneur et une seconde couche (10) comprend un matériau de support mécanique, ou au moins deux couches (11) comprennent un matériau d'actionneur
    - la mise en contact de la première et/ou de la seconde couche avec une électrode (13)
    - la gravure, de préférence par l'arrière, et le retrait éventuel de la butée de gravure,
    de sorte qu'une membrane oscillante (1), de préférence sous la forme d'une structure en méandre, est maintenue par un support (4) formé par le substrat (8), dans lequel la membrane oscillante (1) comprend, pour générer ou absorber des ondes de pression du fluide dans une direction verticale, au moins deux sections verticales (2) ou plus, lesquelles sont formées parallèlement à la direction verticale et de sorte que les deux sections verticales (2) ou plus peuvent être excitées jusqu'à des oscillations horizontales par commande de l'au moins une électrode (13), ou
    de sorte que, lorsque les deux sections verticales (2) ou plus sont excitées pour produire des oscillations horizontales au niveau de l'au moins une électrode, un signal électrique peut être généré.
EP20168836.3A 2020-01-17 2020-04-08 Haut-parleurs mems ayant une efficacité accrue Active EP3852391B1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
JP2022542931A JP2023511538A (ja) 2020-01-17 2021-01-15 改良された性能を有するｍｅｍｓトランスデューサ
KR1020227027423A KR20220130720A (ko) 2020-01-17 2021-01-15 향상된 성능을 갖는 mems 변환기
US17/758,923 US11800294B2 (en) 2020-01-17 2021-01-15 MEMS transducer with improved performance
CN202180016496.XA CN115280797A (zh) 2020-01-17 2021-01-15 具有改进的性能的mems换能器
PCT/EP2021/050766 WO2021144400A1 (fr) 2020-01-17 2021-01-15 Transducteur mems à performance accrue
EP21700309.4A EP4091340A1 (fr) 2020-01-17 2021-01-15 Transducteur mems à performance accrue

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP20152560 2020-01-17

Publications (2)

Publication Number Publication Date
EP3852391A1 EP3852391A1 (fr) 2021-07-21
EP3852391B1 true EP3852391B1 (fr) 2024-05-08

Family

ID=69187544

Family Applications (2)

Application Number Title Priority Date Filing Date
EP20168836.3A Active EP3852391B1 (fr) 2020-01-17 2020-04-08 Haut-parleurs mems ayant une efficacité accrue
EP21700309.4A Pending EP4091340A1 (fr) 2020-01-17 2021-01-15 Transducteur mems à performance accrue

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP21700309.4A Pending EP4091340A1 (fr) 2020-01-17 2021-01-15 Transducteur mems à performance accrue

Country Status (6)

Country Link
US (1) US11800294B2 (fr)
EP (2) EP3852391B1 (fr)
JP (1) JP2023511538A (fr)
KR (1) KR20220130720A (fr)
CN (1) CN115280797A (fr)
WO (1) WO2021144400A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4236367A1 (fr) 2022-02-28 2023-08-30 Hahn-Schickard-Gesellschaft für angewandte Forschung e.V. Ondulations ou zones d'affaiblissement sur les structures d'ancrage des membranes transductrices mems verticales
WO2023161469A1 (fr) 2022-02-28 2023-08-31 Hahn-Schickard-Gesellschaft Für Angewandte Forschung E. V. Ondulations ou zones affaiblies sur les structures d'armature des membranes de convertisseurs mems verticaux
EP4279444A1 (fr) * 2022-05-18 2023-11-22 Hahn-Schickard-Gesellschaft für angewandte Forschung e.V. Actionneur mems, en particulier micromiroir, à infléchissement élevé
EP4290887A1 (fr) 2022-06-10 2023-12-13 Hahn-Schickard-Gesellschaft für angewandte Forschung e.V. Procédé de fabrication d'une pluralité de transducteurs mems à capacité élevée
EP4297432A1 (fr) 2022-06-21 2023-12-27 Hahn-Schickard-Gesellschaft für angewandte Forschung e.V. Procédé de fabrication d'un transducteur mems utilisant l'étirement d'une matière d'actionneur
DE102022209186A1 (de) 2022-09-05 2024-03-07 Robert Bosch Gesellschaft mit beschränkter Haftung Mikrofluidisches Interaktionselement zur Erzeugung und/oder Erfassung eines Volumenstroms eines Fluids sowie eine akustische Vorrichtung mit einem solchen mikrofluidischen Interaktionselement
DE102022211284A1 (de) * 2022-10-25 2024-04-25 Robert Bosch Gesellschaft mit beschränkter Haftung Mikromechanische Struktur und mikromechanischer Lautsprecher
SE2350283A1 (en) * 2023-03-14 2024-03-26 Myvox Ab A micro-electromechanical-system based micro speaker

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3820851B2 (ja) * 2000-07-13 2006-09-13 敏孝 丈井 圧電スピーカー
JP3919695B2 (ja) * 2003-04-18 2007-05-30 敏孝 丈井 フリーエッジにしたアコーディオン形状電気音響変換器
DE102015210919A1 (de) 2015-06-15 2016-12-15 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. MEMS-Wandler zum Interagieren mit einem Volumenstrom eines Fluids und Verfahren zum Herstellen desselben
DE102017206766A1 (de) * 2017-04-21 2018-10-25 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Mems-wandler zum interagieren mit einem volumenstrom eines fluids und verfahren zum herstellen desselben
US10609474B2 (en) 2017-10-18 2020-03-31 xMEMS Labs, Inc. Air pulse generating element and manufacturing method thereof

Also Published As

Publication number Publication date
JP2023511538A (ja) 2023-03-20
EP3852391A1 (fr) 2021-07-21
US20230047856A1 (en) 2023-02-16
WO2021144400A1 (fr) 2021-07-22
US11800294B2 (en) 2023-10-24
CN115280797A (zh) 2022-11-01
EP4091340A1 (fr) 2022-11-23
KR20220130720A (ko) 2022-09-27

Similar Documents

Publication Publication Date Title
EP3852391B1 (fr) Haut-parleurs mems ayant une efficacité accrue
EP3632135B1 (fr) Transducteur acoustique micromécanique
EP3308555B1 (fr) Transducteur mems pour interagir avec un flux volumique d'un fluide et son procede de fabrication
EP3100467B1 (fr) Mems comprenant des actionneurs piézoélectriques micromécaniques pour obtenir des forces et des déflexions élevées
DE102012220819B4 (de) Schallwandler mit einer ersten und einer zweiten menge von ineinandergreifenden kammfingern
EP3457098B1 (fr) Dispositif d'analyse de spectre de vibrations/sonore et procédés d'acquisition et d'analyse d'informations de fréquence
EP2126992B1 (fr) Composant piézoélectrique
DE102016221251A1 (de) System und Verfahren für ein Differenzialkammantrieb-MEMS
DE102006055147A1 (de) Schallwandlerstruktur und Verfahren zur Herstellung einer Schallwandlerstruktur
WO2013152899A1 (fr) Ensemble membrane pour un transducteur de mesure micro-électromécanique et procédé de fabrication d'un ensemble membrane
DE102010019740A1 (de) Miniaturisiertes Energieerzeugungssystem
JP2009055683A (ja) 圧電駆動型ｍｅｍｓ装置および携帯端末
DE102019220126B4 (de) Bewegbares Piezoelement und Verfahren zum Herstellen eines bewegbaren Piezoelements
DE102010035247A1 (de) Dielektrischer kapazitiver MEMS Energiewandler
WO2023161469A1 (fr) Ondulations ou zones affaiblies sur les structures d'armature des membranes de convertisseurs mems verticaux
EP4236367A1 (fr) Ondulations ou zones d'affaiblissement sur les structures d'ancrage des membranes transductrices mems verticales
WO2023247473A1 (fr) Procédé de fabrication d'un convertisseur mems par étirement d'un matériau actionneur
EP4058400A1 (fr) Composant mems comprenant un élément mobile dans le plan et procédé pour faire fonctionner ce composant
WO2023237397A1 (fr) Procédé de production d'une pluralité de transducteurs mems à capacité de performance élevée
DE102022210125A1 (de) Mikromechanische Schallwandlervorrichtung und entsprechendes Schallwandlungsverfahren
EP3799966B1 (fr) Convertisseur acoustique et procédé de génération/réception d'une onde acoustique
DE102022209186A1 (de) Mikrofluidisches Interaktionselement zur Erzeugung und/oder Erfassung eines Volumenstroms eines Fluids sowie eine akustische Vorrichtung mit einem solchen mikrofluidischen Interaktionselement
DE102022212404A1 (de) Mikromechanisches Bauteil und Verfahren zum Erzeugen und/oder Verstärken eines Schallsignals
WO2023198340A1 (fr) Microscanner ayant des éléments piézoélectriques hétérogènes et son procédé de production

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20220121

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230522

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20230703

GRAJ Information related to disapproval of communication of intention to grant by the applicant or resumption of examination proceedings by the epo deleted

Free format text: ORIGINAL CODE: EPIDOSDIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTC Intention to grant announced (deleted)
INTG Intention to grant announced

Effective date: 20231130

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 502020007910

Country of ref document: DE

Owner name: HAHN-SCHICKARD-GESELLSCHAFT FUER ANGEWANDTE FO, DE

Free format text: FORMER OWNER: ANMELDERANGABEN UNKLAR / UNVOLLSTAENDIG, 80297 MUENCHEN, DE

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502020007910

Country of ref document: DE