MEMS microphone with integrated resistive heating

Abstract

MEMS converter (200, 300, 400) for integration into a microphone arrangement (100) having a housing in which the MEMS converter is arranged, the MEMS converter comprising: a substrate (202) comprising an aperture (212); an electroacoustic transduction element (204) coupled to the substrate (202), the transduction element (204) comprising a fixed electrode (210) and a movable electrode (208) located on different layers of the MEMS transducer to form a variable capacitor, and the movable electrode (208) being at least partially disposed over the aperture (212); electrical contacts (414a, 414b) coupled to the transduction element (204); a resistor (206, 306); and electrical contacts (416) coupled to the resistor (206, 306) and electrically insulated from the electrical contacts (414a, 414b) of the transduction element (204), wherein the transduction element (204) comprises an insulating material (214) connected to the substrate, wherein the resistor (206, 306) is arranged laterally offset from the aperture (212) of the substrate (202, 502) and the insulating material (214) forms a backplate structural layer (508, 516), in the surface of which facing the substrate (202) the fixed electrode (210) is sunk, wherein the resistor (306) is sunk into said surface and is arranged in the same layer as the fixed electrode (210) and is formed of the same material, or wherein the resistor (206) is suspended from said surface and is arranged in the same layer as the movable electrode (208) and is formed of the same material.

Description

AREA OF REVELATION

[0001] The present disclosure relates to sensors for microelectromechanical systems (MEMS), and more particularly to MEMS sensors having a resistor disposed on the same substrate. BACKGROUND

[0002] Microphone arrays, which incorporate microelectromechanical systems (MEMS) acoustic transducers, convert acoustic energy into an electrical signal. These arrays can be used in mobile communications devices, laptops, and other equipment and machines, among others. An important parameter for a microphone array is the acoustic signal-to-noise ratio (SNR), which compares the desired signal level (for example, the signal amplitude due to acoustic disturbances detected by the microphone array) with the background noise level. The signal-to-noise ratio can be used to determine the functional status of the microphone array.

[0003] Typical MEMS microphones are known from DE 10 2017 207 461 A1 and DE 601 33 679 T2. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The foregoing and other features of the present disclosure will become more fully apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings. These drawings illustrate only several embodiments according to the disclosure and are therefore not to be considered limiting of its scope. Various embodiments are described in more detail below in conjunction with the accompanying drawings. Fig. 1 is a schematic representation of the potential resistor locations in a microphone assembly according to an illustrative embodiment; Fig. 2 is a schematic diagram of an exemplary MEMS transducer with a free plate diaphragm and an air-isolated hanging resistor according to a first illustrative embodiment; Fig. 3 is a schematic diagram of an exemplary MEMS transducer with a free plate membrane and air-isolated floating resistor according to a second illustrative embodiment; Fig. 4A-B are schematic diagrams of an exemplary MEMS transducer with a forced membrane and air-isolated floating resistor according to a third illustrative embodiment; Fig. 5 is a three-dimensional diagram of an exemplary MEMS converter according to the embodiment of Fig. 2; Fig. 6 is a three-dimensional diagram of an exemplary MEMS converter according to the embodiment of Fig. 3; Fig. Figure 7 is a graph of resistance sensitivity versus frequency illustrating the entire range of the audio frequency band; and Fig. 8A-B show a schematic representation of a microphone arrangement and a resistor combination according to a fourth illustrative embodiment; and Fig. Figure 9 is a schematic diagram of an exemplary clamped membrane MEMS transducer. DETAILED DESCRIPTION

[0005] The drawings referred to in the following descriptions schematically illustrate the embodiments. The scales, distances, positional relationships, and the like of the elements may be exaggerated, and the illustration of some elements may be omitted for clarity. In the following descriptions, the same name or reference numeral generally represents the same element or an element made of the same material, and its repeated detailed description will be omitted where appropriate.

[0006] In general, the transducer disclosed herein is a microelectromechanical system (MEMS) transducer for integration into a microphone array configured to generate heat-generated acoustic signals. The MEMS transducer generally includes a substrate having an aperture, an electroacoustic transduction element disposed at least partially over the aperture and coupled to the substrate, electrical contacts coupled to the transduction element, and a resistor integrated into the substrate or the transduction element. The resistor is coupled to electrical contacts that are electrically isolated from the contacts of the MEMS transducer or transduction element. The transduction element includes an insulating material coupled to the substrate.The transduction element is a variable capacitor comprising a fixed electrode and a movable electrode disposed at least partially above the substrate aperture. The fixed electrode or the movable electrode is formed on the insulating material. The resistor can be formed on the insulating material or suspended from the insulating material.

[0007] According to some embodiments described herein, a microphone assembly configured to generate heat-generated acoustic signals comprises a MEMS acoustic transducer, an integrated circuit, a substrate, a can, and an isolated resistor. The microphone assembly generally comprises a MEMS transducer and an integrated circuit disposed within an internal volume of a package having a sound port and electrical circuitry suitable for integration with a host device (e.g., using surface mount technology). In one embodiment, the package includes a can disposed on a substrate or base, the combination of which forms an internal volume in which the transducer substrate and the integrated circuit are disposed.The MEMS transducer may be a capacitive, piezoelectric, or other MEMS device configured to convert acoustic energy into an electrical signal. The MEMS transducer is coupled to the integrated circuit, and the integrated circuit is connected to contacts at the electrical interface. The integrated circuit is capable of receiving and conditioning the electrical signal generated by the transducer. Such signal conditioning may include, among other things, buffering, filtering, amplification, A / D conversion, protocol interface conversion, and other signal conditioning or processing. The integrated circuit may be an application-specific integrated circuit (ASIC). In some embodiments, the MEMS transducer is coupled to and positioned proximate to a sound port formed in the substrate.In other embodiments, the transducer is coupled to and positioned near a sound port located in the can or in the cover portion of the housing.

[0008] Heating of a back volume between a substrate and a cover of a microphone device can generate sound waves, resulting in ambient noise. Various embodiments disclosed herein can increase the functionality and applications of MEMS microphones and MEMS transducers by exploiting design aspects previously considered flaws. For most microphone devices, the acoustic or ambient noise generated by the device negatively impacts the quality of the captured sound, particularly due to the proximity of the signal to the microphone itself. Internally generated acoustic noise is generally considered undesirable because it is difficult to control and mixes with external ambient noise, affecting the signal. However, if the generation of the acoustic noise was controllable by an integrated circuit, the noise can be intentionally generated.Among other advantages, a controllable acoustic device in a MEMS microphone device can enable the device to be used in self-test applications and for noise cancellation. The details of a device designed for such functions are described in the . Fig. 1-7 are explained in more detail.

[0009] In Fig. 1, a microphone assembly 100 comprises a substrate and a can forming a closed volume in which an integrated circuit and a MEMS transducer are arranged. To generate acoustic stimulation at the device level, a heat source must be placed within the closed volume of the microphone device. The heat source must be small, have high power consumption efficiency, and be limited in cost and complexity. In the present embodiments, a resistor is used as the heat source, but it is appreciated that any other heat source with similar functionality would suffice. Electrical resistance is a fundamental heat generator that is controllable by the size of the resistor and the amount of current supplied to the resistor.To achieve maximum efficiency and control of the heat source, the resistor is preferably air-insulated and must be thermally coupled to the air within the enclosed volume. Four potential locations for the resistor are identified within the enclosed volume of the microphone array: on the substrate (102), on the integrated circuit (104), within the base substrate (106), and on the MEMS die (108).

[0010] Position 102 on the substrate requires free space on the substrate to allow the resistor footprint to be mounted within the enclosed volume, limiting the possibility of further size reduction. Position 102 also increases manufacturing costs because a third element must be added to the substrate before the can or cover can be added. Junction 104 on the integrated circuit results in poor thermal coupling with the enclosed volume because the resistor would be encapsulated in dielectric interlayers. Position 104 would also increase the size of the integrated circuit. Junction 106 within the base substrate also results in poor thermal coupling with the enclosed volume because the base substrate is sealed during manufacturing (for example, with FR-4 and solder mask).Position 108 on the MEMS die takes up less space than position 102 and, unlike positions 104 and 106, exhibits good thermal coupling because the MEMS die is exposed to air in the enclosed back volume. At position 108, the resistor can be electrically isolated from the transducer because the manufacturing process provides electrically isolated conductive structures. Furthermore, the manufacturing process provides flexibility in the design of both the resistor and the transducer.

[0011] Fig. Figure 2 is a schematic diagram of a MEMS die 200 with an electroacoustic transduction element and a resistor according to a first embodiment. The MEMS die 200 includes a substrate 202, an electroacoustic transduction element (transducer) 204, and a resistor 206. Fig. 2, the transducer 204 includes a diaphragm 208 and a transducer plate 210, the diaphragm being aligned parallel to the transducer plate and configured to move relative to the transducer plate in response to pressure fluctuations received via a sound port 212. The transducer 204 is mounted at least partially over the sound port 212. Alternatively, the transducer 204 could be a device other than a capacitive device and could be mounted on a lid or cover (not shown) instead of the base as described herein. The transducer 204 may generate an electrical signal in response to the movement of the diaphragm, which signal is detected by an integrated circuit (not shown). The transducer 204 may include electrical contacts coupled to the integrated circuit, and the integrated circuit may be programmed to receive and process the electrical signal generated by the transducer 204.The integrated circuit can be an application-specific integrated circuit (ASIC) or another type of programmable system on a chip.

[0012] Resistor 206 may be an air-insulated resistor manufactured similarly to membrane 208 to maintain existing manufacturing processes. In the illustrative embodiment, an insulating material 214 is coupled to substrate 202. Resistor 206 may be made of the same material as the membrane and may be suspended from the insulating material with tabs 216. The resistor is integrated with substrate 202 or transducer substrate 204 and is electrically isolated from transducer 204. Resistor 206 is coupled to electrical contacts that interface with the integrated circuit.

[0013] The integrated circuit can be programmed to use a thermoacoustic relationship to drive a current through resistor 206 to heat the enclosed volume and generate a known acoustic signal that can be detected by acoustic transducer 204. The known acoustic signal then impinges on diaphragm 208, generating an electrical signal representative of the acoustic signal. The integrated circuit can be programmed to analyze the electrical signal to determine a state of the transducer, such as a blocked, inoperative, or operational state, from the frequency response of the detected signal.The integrated circuit can further be programmed to detect ambient noise from an incoming acoustic signal and drive a current through the resistor to generate a heat-induced acoustic signal that cancels the ambient noise.

[0014] Fig. 3 is a schematic diagram of a MEMS die 300 with an electroacoustic transduction element and a resistor according to a second embodiment. The MEMS die 300 includes a substrate 202, an electroacoustic transduction element (transducer) 204, and a resistor 306. The resistor 306 is an air-insulated resistor manufactured similarly to the backplate 210 to maintain existing manufacturing processes. In the present embodiment, an insulating material 214 is coupled to the substrate 202. The resistor 306 is made of the same material as the backplate and is formed on the insulating material 214. The resistor can be integrated with the substrate 202 or the transducer substrate 204 and is electrically isolated from the transducer 204.The integrated circuit may be programmed to drive a current through resistor 306 and generate a known acoustic signal and use the signal to evaluate a status of transducer 204 and / or detect and / or reject ambient noise in an incoming signal, in a manner similar to that described with respect to FIG. Fig. 2 described.

[0015] Fig. 4A-B are schematic representations of a MEMS die 400 with an electroacoustic transduction element and a resistor according to a third embodiment. The MEMS die 400 includes a substrate 202, an electroacoustic transduction element (transducer) 404, and a resistor 306. In Fig. 4A, the transducer 404 includes a movable electrode (diaphragm) 408 and a fixed electrode (transducer plate) 410, with the diaphragm oriented parallel to the transducer plate. An electrical signal representing the acoustic stimulus can be generated and transmitted via electrical contacts 414a and 414b to an integrated circuit for processing circuitry, as shown in Fig. 4B. The transducer 404 is mounted at least partially over the sound port 412. Alternatively, the transducer 404 could be mounted on a lid or cover (not shown) instead of the base, as described herein. The transducer 404 can generate an electrical signal in response to the movement of the diaphragm, which signal is detected by an integrated circuit (not shown). In some embodiments, the transducer plate 410 may be absent from the transducer 404, and the diaphragm 408 is made of piezoelectric materials. An electrical signal is generated due to the mechanical stress in the piezoelectric layers resulting from the deflection due to the incident sound pressure. The integrated circuit can be coupled to the transducer 404 via the electrical contacts 414a-b and programmed to receive and process the electrical signal generated by the transducer 404.The integrated circuit may be an application-specific integrated circuit (ASIC) or another type of programmable system on a chip. The integrated circuit may be programmed to drive a current through resistor 306 via electrical contacts 416 and generate a known acoustic signal, and use the signal to evaluate a status of transducer 404 and / or detect and / or reject ambient noise in an incoming signal, similar to that described with respect to FIG. Fig. 2 described.

[0016] Fig. 5 is a three-dimensional representation of a MEMS converter 500 with an integrated resistor according to the embodiment of Fig. 2. The MEMS transducer 500 includes a substrate 502, a microphone 504 mounted on the substrate, and an air-sprung resistor 514. The microphone 504 includes a backplate electrode layer 506, a backplate structural layer 508, and a diaphragm 510 aligned parallel to each other. The diaphragm 510 can move freely with respect to the backplate electrode layer 506 in response to pressure fluctuations and is located within a set of peripheral posts 512 protruding from the backplate structural layer 508 and arranged around the perimeter of the diaphragm 510. The substrate 502 can be coupled to an insulating layer 516. The resistor 514 is shaped to be suspended from the insulating layer 516 and is made of the same material as the diaphragm.

[0017] Fig. 6 is a three-dimensional representation of a MEMS converter 600 with an integrated resistor according to the embodiment of Fig. 3. The MEMS transducer 600 includes a substrate 502, a microphone 604 mounted on the substrate, and an air-sprung resistor 616. The microphone 604 includes a backplate electrode layer 506, a backplate structural layer 508, and a diaphragm 510 aligned parallel to each other. The diaphragm 510 is configured to move relative to the backplate electrode layer 506 in response to pressure fluctuations. The diaphragm 510 is suspended from a central post 614 and positioned within a set of peripheral posts 512 that protrude from the backplate structural layer 508 and are arranged around the perimeter of the diaphragm 510. The substrate 502 can be coupled to an insulating layer 618. The resistor 616 is formed within the insulating layer 618 and is made of the same material as the backplate electrode layer 506.

[0018] It will be appreciated that the various embodiments described herein are not limited to the illustrative embodiments of the Fig. 2-6. For example, the MEMS die may comprise any combination of resistor or MEMS transducer that is Fig. Furthermore, the transducer and resistor may be made of the same or different materials, depending on the manufacturing process used and the design requirements.

[0019] Fig. Figure 7 is a graph 700 of resistor sensitivity versus frequency, illustrating the entire range of the audio frequency band. The graph shows the entire range of the human-perceivable audio frequency band from 20 Hz to 20 kHz and is divided into two regions: region 701 extends from 20 Hz to 2 kHz, and region 702 extends from 2 kHz to 20 kHz. The acoustic coupling between the resistor and the air dominates the frequency band spanned by region 701, and the electrical coupling between the resistor and the integrated circuit dominates the frequency band spanned by region 702. Region 701 covers the frequency range (2 Hz to 2 kHz) in which a sufficiently sensitive resistor can produce an acoustic signal, all of which are perceptible to the human ear.When a person speaks into a microphone, such as in telephone communication, the generated acoustic signal is within a usable speech frequency range of approximately 300 Hz to 3400 Hz. Furthermore, telephones rely on harmonics of a low fundamental frequency in this range to produce aliasing signals where the entire range is audible. Therefore, any ambient noise detected at the microphone would be transmitted as part of the acoustic signal. However, any signal from 20 Hz to 2 kHz (and all aliased signals) can be resistively counteracted by a thermally generated acoustic signal, effectively suppressing the ambient noise to produce a smoother acoustic signal.The integrated circuit can be programmed to identify a frequency of the ambient noise detected at the transducer and drive current to the resistor to generate noise at a frequency where the aliased harmonic signals effectively cancel each other. The current range of the embodiment allows for noise rejection of most sounds that would enter a microphone easily perceived by the human ear.

[0020] Fig. 8A-B illustrate an arrangement of microphone array and resistor according to a fourth embodiment and a particular application. Fig. 8A is a cross-sectional view of a microphone assembly 800 including a MEMS transducer 802 mounted on a base 804 at least partially over a sound port 806 filled with water (or other liquid) 808 after a liquid ingress event occurs. The water 808 prevents sound from properly entering the sound port 806 to access the acoustic transducer 802. The base 804 may be a printed circuit board or other surface-mount electrical interface. The sound port 806 is a thermally and electrically conductive acoustic port, such as a plated through-hole. The sound port 806 may have a cylindrical shape and extends through the base 804 to a bottom surface of the base. The bottom surface of the base 804 has a solder ring 810 mounted thereon, to which the conductive sound port 806 is electrically coupled.A solder resist ring 812 acts as an insulator on the underside of the base 804 and serves as an insulator between the electrically conductive sound port 806 and the MEMS transducer 802.

[0021] An annular resistive heating element (resistor) 814 is arranged around the sound port in a ring of electrically conductive material. The resistor 814 may completely or partially enclose the perimeter of the sound port 806. The resistor 814 may consist of concentric rings of resistive film 816, an outer copper pad 818 connected to an integrated circuit, and an inner copper pad 820 connected to the sound port 806. Alternatively, the resistor 814 may consist of a continuous resistive film that connects the sound port 806 to the integrated circuit of Fig. 1. The integrated circuit can supply power to resistor 814 to generate heat. The heat generated by the resistor can be dissipated through sound port 806 to heat the water 808 trapped therein. The supplied heat increases the temperature of the water in the sound port to enhance the latent heat of vaporization of the liquid water and increase the pressure of the air inside the microphone assembly. The pressurized air forces the water out of sound port 806, effectively cleaning the microphone and restoring the assembly to full functionality.

[0022] In some embodiments, the membrane in the acoustic transducer may also be used as a heating element with a similar function to the annular resistive heating element 814. As in Fig. As shown in Figure 9, by using a second electrical contact 414c to the diaphragm in the acoustic transducer, the integrated circuit can be configured to allow an electrical current to flow through the diaphragm between contacts 414a and 414c, resulting in resistive heating of the diaphragm. The increased temperature of the diaphragm can contribute to the evaporation of fluid trapped in the sound port in contact with the diaphragm.

[0023] In some embodiments, the annular resistor can also be used to keep the MEMS die soft in cold ambient temperatures. When the microphone assembly is exposed to extreme cold, the MEMS die mount may stiffen, and use of the microphone may contribute to the package's stress on the MEMS die. In some embodiments, a temperature sensor can be mounted within a back volume of the microphone assembly to sense the ambient temperature within the microphone package. The temperature sensor is coupled to the integrated circuit, which is programmed to supply current to the annular resistor. When the temperature within the microphone assembly drops below a predetermined threshold, such as 0 degrees Celsius, the integrated circuit is programmed to supply current to the annular resistor to heat the MEMS die to which it is connected, as shown in [Figure 1]. Fig. can be seen. Resistive heating of the MEMS die is intended to reduce stress on the MEMS attach and can mitigate performance changes or prevent damage resulting from stress. The integrated circuit can be programmed to power the annular resistor at the microphone array level or at the system level. For example, the integrated circuit in the microphone array can be connected to a temperature sensor and programmed to control the annular resistor.

[0024] The above implementation requires more circuitry on the integrated circuit and additional space on the PCB base to accommodate an additional soldering point for an electrical circuit. In some implementations, instead of including a temperature sensor inside the microphone housing and using the integrated circuit to drive the resistor, the resistor control and / or driver circuitry can be implemented outside the microphone housing, for example, in the host device. For example, a host device (such as a phone, tablet, recording device, or similar) can include circuitry / functionality to control the annular resistor, for example, with a native temperature sensor and integrated circuit.The integrated circuit is programmed to control the microphone array within the system, which requires reduced circuitry because the integrated circuit can utilize the resistor's electrical contacts 416 for thermal regulation.

[0025] It is appreciated that, although the ideas are presented herein as individual embodiments, it is possible to combine elements of the embodiments described herein to obtain a combination of features not explicitly illustrated. For example, the annular resistor may be combined with any of the Fig. 2-6 described arrangements of acoustic transducers. Furthermore, the embodiments described here are not limited to a single resistor and can additionally comprise a combination of the annular resistor from Fig. 8B with each of the Fig.2-6, so that the embodiment includes two resistors for alternating purposes. In this case, the electrically isolated set of electrical contacts 416 for the resistor is present on the MEMS die, and the outer copper pad 818 or electrode for the annular resistor is present in the base of the circuit board.

[0026] According to some embodiments, a MEMS (microelectromechanical system) transducer for integration into a microphone assembly comprising a housing in which the transducer is disposed, a substrate having a diaphragm; an electroacoustic transduction element disposed at least partially over the diaphragm and coupled to the substrate; electrical contacts coupled to the transducer; and a resistor coupled to electrical contacts that are electrically isolated from the electrical contacts of the transducer.

[0027] In some embodiments, the transduction element may comprise an insulating material coupled to the substrate, and the resistor is formed on the insulating material. The substrate may have a mounting surface and a surface opposite the mounting surface. The insulating material on which the resistor is formed is coupled to the surface of the substrate opposite the mounting surface. The resistor may be laterally offset relative to the aperture of the substrate. The transduction element may be a variable capacitor comprising a fixed electrode and a movable electrode located at least partially above the aperture of the substrate. At least one of the fixed electrode and the movable electrode may be formed on the insulating material. The movable electrode may be disposed between the substrate and the fixed electrode.

[0028] In some embodiments, the resistor is suspended from the insulating material. The substrate may have a mounting surface and a surface opposite the mounting surface. The insulating material from which the resistor is suspended may be coupled to the surface of the substrate opposite the mounting surface. The resistor may be laterally offset relative to the aperture of the substrate. The transduction element may be a variable capacitor comprising a fixed electrode and a movable electrode located at least partially above the aperture of the substrate. At least one of the fixed electrode and the movable electrode may be formed on the insulating material. The movable electrode may be disposed between the substrate and the fixed electrode.The converter may be a variable capacitor comprising a fixed electrode and a movable electrode disposed at least partially over the aperture of the substrate, wherein at least one of the fixed electrode and the movable electrode is formed on the insulating material.

[0029] According to some embodiments, a microphone assembly comprises a housing having a sound port and a surface-mountable electrical interface; an acoustic transducer disposed within the housing, the transducer having electrical contacts; a resistor disposed within the housing, the resistor having electrical contacts electrically isolated from the electrical contacts of the transducer; and an integrated circuit disposed within the housing and electrically coupled to the resistor, the transducer, and the electrical interface. The integrated circuit may be configured to supply power to the resistor and detect an acoustic signal generated by the acoustic transducer in response to detecting a pressure change within the housing caused by heat generated by the resistor upon application of the power.

[0030] In some embodiments, the resistor may be integrated with the acoustic transducer. The acoustic transducer may be a microelectromechanical device (MEMS) transducer comprising a substrate with a bezel acoustically coupled to the sound port, and the transducer is coupled to the substrate and may be disposed at least partially over the bezel. The transducer may be formed on an insulating material coupled to the substrate. The resistor may be formed on the insulating material. The substrate may include a mounting surface attached to the housing and a surface opposite the mounting surface. The transducer and the insulating material on which the resistor is formed may be coupled to the surface of the substrate opposite the mounting surface. The resistor may be laterally offset relative to the bezel of the substrate.The converter may be a variable capacitor comprising a fixed electrode and a movable electrode disposed at least partially over the aperture of the substrate, wherein at least one of the fixed electrode and the movable electrode is formed on the insulating material. The movable electrode may be disposed between the substrate and the fixed electrode.

[0031] In some embodiments, the microphone assembly includes an annular resistor comprised of a resistive film disposed around the sound port. The annular resistor includes an electrical contact pad connected to the sound port. The electrical contact pad may be an extension of the sound port or an internal copper pad for connection to the sound port. The sound port may be thermally and electrically conductive. The annular resistor includes an electrode electrically coupled to the integrated circuit. The integrated circuit is configured to supply power to the electrode to generate resistive heat in the sound port; the heat is then thermally transferred throughout the sound port.The annular resistor can be mounted on the surface-mount electrical interface of the microphone assembly or it can be embedded within the surface-mount electrical interface. In some embodiments, the diaphragm in the acoustic transducer is used as a resistive heating element, where the diaphragm includes two separate electrical contacts connected to the integrated circuit. The integrated circuit is configured to supply current to the diaphragm to generate resistive heating on the surface of the diaphragm. In some embodiments, the resistor coupled to the transducer is the annular resistor. In some embodiments, the resistor coupled to the transducer is the diaphragm itself. In some embodiments, the microphone assembly includes both the resistor coupled to the transducer and the annular resistor arranged to surround the sound port.

[0032] The subject matter described herein sometimes illustrates various components contained within or connected to various other components. It should be understood that such depicted architectures are illustrative, and that, in fact, many other architectures may be implemented that achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "connected" such that the desired functionality is achieved. Therefore, any two components combined here to achieve a particular functionality can be considered to be "connected" to each other such that the desired functionality is achieved, regardless of architectures or intermediary components.Likewise, two components linked in this manner may also be considered "operably connected" or "operably coupled" to achieve the desired functionality, and two components that can be linked in this manner may also be considered "operably coupled" to achieve the desired functionality. Specific examples of operably coupled components include, but are not limited to, physically coupled and / or physically interacting components and / or wirelessly interacting and / or wirelessly interacting components and / or logically interacting and / or logically interacting components.

Claims

[1] MEMS converter (200, 300, 400) for integration into a microphone arrangement (100) having a housing in which the MEMS converter is arranged, the MEMS converter comprising: a substrate (202) comprising an aperture (212); an electroacoustic transduction element (204) coupled to the substrate (202), the transduction element (204) comprising a fixed electrode (210) and a movable electrode (208) located on different layers of the MEMS transducer to form a variable capacitor, and the movable electrode (208) being at least partially disposed over the aperture (212); electrical contacts (414a, 414b) coupled to the transduction element (204); a resistor (206, 306); and electrical contacts (416) coupled to the resistor (206, 306) and electrically insulated from the electrical contacts (414a, 414b) of the transduction element (204), wherein the transduction element (204) comprises an insulating material (214) connected to the substrate, wherein the resistor (206, 306) is arranged laterally offset from the aperture (212) of the substrate (202, 502) and the insulating material (214) forms a backplate structural layer (508, 516), in the surface of which facing the substrate (202) the fixed electrode (210) is sunk, wherein the resistor (306) is sunk into said surface and is arranged in the same layer as the fixed electrode (210) and is formed of the same material, or wherein the resistor (206) is suspended from said surface and is arranged in the same layer as the movable electrode (208) and is formed of the same material. [2] MEMS converter according to the preceding claim, wherein the movable electrode (208) is arranged between the substrate (202) and the fixed electrode (210). [3] Microphone arrangement (100), comprising: MEMS converter (200, 300, 400) according to one of the preceding claims, a housing having an interface for external surface-mount devices and a sound port (212), wherein the MEMS transducer (200, 300, 400) is arranged in the housing; an integrated circuit (104) disposed in the housing and electrically coupled to the MEMS transducer (200, 300, 400) and to contacts at the external device interface. [4] Microphone assembly (100) according to the preceding claim, wherein the integrated circuit (104) is programmed to determine a frequency of the ambient noise detected at the transduction element (204) and to control the current to the resistor (206, 306) to generate noise at a frequency at which aliased harmonic signals effectively cancel each other for noise cancellation.

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