Integrated MEMS Electrostatic Micro-Speaker

Abstract

In one example, the present invention provides a micro-speaker device. This device comprises a movable diaphragm device consisting of the thickness of a silicon or graphene material, having a first surface and a second surface opposite the first surface. This device comprises a housing surrounding the movable diaphragm device, an electrode device, and an encapsulation device. The electrode device may be part of a CMOS device with an electronic device integrated thereon. The device comprises an enclosure with vents on the opposite side of the movable diaphragm to allow air to enter and exit through one or more vents to generate a sound pressure signal. The diaphragm can be electrostatically actuated from one or more surfaces including the electrode device and the encapsulation device.

Description

Cross - reference to related applications

[0001] The present invention claims priority to U.S. Patent Application No. 17 / 838,780, filed on June 13, 2022. This application is incorporated herein by reference for all purposes.

Background Art

[0002] The present invention relates to micro - electro - mechanical systems, commonly referred to as "MEMS". In particular, the present invention provides MEMS speaker devices including MEMS actuator devices and related methods. Although the present invention is described in a specific example, it will be recognized that its scope of application is much broader.

[0003] A loudspeaker, also called a speaker driver or simply a speaker, is an electro - acoustic transducer. Loudspeakers are an essential part of many consumer gadgets such as home music systems, MP3 players, smartphones, laptops, tablets, earphones, etc. As mobile devices are becoming smaller and thinner, speakers are also getting smaller. In one example, in terms of terms based on the size of the speaker, generally a speaker with a diameter of 4 inches or more is called a loudspeaker, a speaker with a diameter of 2 - 4 inches is called a mini - speaker, and a speaker with a diameter of less than 2 inches is called a micro - speaker. More recently, due to the popularity of earphones, the size of the speaker has been reduced to less than 1 inch in diameter.

[0004] However, most conventional speakers are still designed based on prior art that is cone-based speakers, which consist of a thin movable diaphragm made of paper, plastic, or similar materials and are driven by a spring element that operates by an electromagnetic signal proportional to the audio signal input to the speaker. Conventional speakers use permanent magnets to generate a magnetic field in which a movable coil that uses electromagnetic force as the driving force operates. Conventional speakers are not compatible with conventional surface mount printed circuit board (PCB) technology and are disadvantageous in the manufacturing flow of OEM (Original Equipment Manufacturers) of electronic systems. In conventional speaker technology, for example, the magnet within the speaker has an adverse effect on other components such as sensors and other electronic devices, resulting in additional constraints on the placement of the speaker within a smartphone. These and other limitations have plagued conventional speakers and related technologies.

[0005] From the above, it can be seen that conventional speakers have limitations in consumer devices.

Summary of the Invention

[0006] The present invention relates to microelectromechanical systems, generally referred to as "MEMS". In particular, the present invention provides a MEMS speaker device and related methods including a MEMS actuator device. Although the present invention is described using specific examples, it will be understood that its scope of application is much broader.

[0007] In one example, the present invention provides a microelectromechanical system. This system includes a movable diaphragm device configured on a semiconductor substrate, having a thickness of a silicon or graphene material, and spatially elongated within a cavity region. The movable diaphragm device has a first surface and a second surface opposite the first surface. The movable diaphragm is connected to at least two cantilevers or springs. Each of the cantilevers or springs is coupled between a peripheral region of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device. This system includes an electrode device coupled to the movable diaphragm device and configured to electrostatically move the movable diaphragm using a pull action that causes movement of the diaphragm in response to an applied electrical signal and to propagate an acoustic signal from one or more of a plurality of vent regions within a cap device.

[0008] In one example, the present invention provides a micro speaker device. This device has a cap device comprising a plurality of vent regions for propagating an acoustic signal. This cap device can be made from a suitable material such as silicon or other rigid substrates that can be processed using semiconductor technology. In one example, this device comprises a Complementary metal-oxide-semiconductor: CMOS (i.e., complementary metal oxide semiconductor) device coupled to the cap device. In one example, the CMOS device comprises at least one vent region (although there may be more) configured such that back pressure flows therethrough. The CMOS device can be a CMOS semiconductor substrate including a plurality of CMOS cells. This device has a cavity region configured between the inner surface of the cap of the cap device and the inner surface of the CMOS of the CMOS device. This device comprises a frame device coupled between the cap device and the CMOS device and forming an outer housing of the cavity region. In one example, the frame device is configured on either or both of the cap device and / or the CMOS device or is configured integrally with either or both of the devices.

[0009] In one example, the device is a movable diaphragm device having a thickness of silicon or graphene material and spatially configured in an elongated shape within the cavity region. In one example, the movable diaphragm device has a first surface and a second surface opposite the first surface. In one example, the movable diaphragm is connected to at least two cantilevers or springs. Each of the cantilevers or springs is coupled between a peripheral region of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device.

[0010] In one example, the device includes a CMOS electrode device configured on an internal region of a CMOS device. That is, the CMOS device includes one or more electrode devices formed on the internal region of the CMOS device.

[0011] In one example, the device has a cap electrode device configured on the inner surface of the cap, and each of the cap electrode device and the CMOS electrode device can electrostatically move a movable diaphragm by a pull action in response to an applied electrical signal, and propagate an acoustic signal from one or more of a plurality of vent regions in the cap device.

[0012] According to an example, the present invention can achieve one or more of these benefits and / or advantages. The present invention provides a MEMS microphone speaker that can reduce the size and profile height of the speaker without affecting performance. In one example, the present invention can integrate CMOS audio processing within a single (monolithic) element with MEMS, thereby miniaturizing the entire audio chain of demanding components such as earphones, wearables, smartwatches, smartphones, etc. In one example, the present invention can be implemented using conventional semiconductor and MEMS process technologies for large-scale commercialization. These benefits and / or advantages, as well as other benefits and / or advantages, can be achieved with the present device and related methods. Details of these benefits and / or advantages are described in more detail throughout this specification and below.

[0013] By referring to the latter part of this specification and the accompanying drawings, the nature and advantages of the present invention will be further understood.

Brief Description of the Drawings

[0014] To better understand the present invention, reference is made to the accompanying drawings. It is to be understood that these drawings are not to be regarded as limiting the scope of the invention, and with reference to the accompanying drawings, in the presently described embodiments, the best mode of the presently understood invention will be described in further detail.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9A

Figure 9B

Figure 9C

Embodiments for Carrying Out the Invention

[0015] According to the present invention, a technology directed to a microelectromechanical system generally called "MEMS" is provided. In particular, the present invention provides a MEMS speaker device including a MEMS actuator device and related methods. Although the present invention has been described with respect to specific embodiments, it will be recognized that the present invention has a much broader scope of application.

[0016] FIG. 1 is a schematic diagram showing a cross-sectional view of a MEMS microphone speaker device according to an embodiment of the present invention. In one example, the device comprises an electrode layer including one or more electrodes (as shown, the term "layer" does not mean a single layer and should be interpreted as including a substrate or substrate layer including an electrode device as shown), forming a bottom structure of the MEMS speaker device. The substrate layer may include a CMOS die (manufactured using semiconductor processing technology) including some or all of an electronic circuit for operating the MEMS microphone speaker. This electronic circuit includes processing of a plurality of audio signals, operation of an actuator device for MEMS, sensing of the movement of MEMS including a diaphragm device, electronic damping, feedback, and other electronic circuits.

[0017] As shown, the electrode layer may have vent holes (or a plurality of vent regions) to allow air movement caused by the movement of the diaphragm coupled to the actuator device. The vent hole or group of vent holes also contributes to increasing the back volume on the back side of the diaphragm (the front side is on the opposite side of the back side, but the terms front side and back side are intended to be used in relation to each other and other terms may be used).

[0018] In one example, the electrode layer may be a CMOS die having one or more metal layers. A portion of the topmost metal layer is used as an electrostatic actuator for implementing one or more electrodes. In one example, the electrodes are connected to a driving electronic circuit and supply a voltage to the electrodes in conjunction therewith. In one example, the metal actuators may be symmetrically arranged or configured using other spatial configurations. The metal actuators are driven by an electrical signal including a DC component and an AC component from driving electronics. The voltage of the actuator generates an electrostatic force in the MEMS layer above the actuation region including the actuator device. The distance between the electrode and the diaphragm can be defined as the actuator gap, which is generally a free space region.

[0019] The "actuator layer" is also referred to as the MEMS layer or the diaphragm layer (in both terms, the term layer does not mean a single layer and may include multiple layers and related structures). The actuator layer is shown as multiple elements in FIG. 1.

[0020] The MEMS layer includes a diaphragm designed to move in a vertical direction (towards and away from the CMOS actuator metal). This diaphragm is connected to a frame or an anchor using MEMS springs, beams, cantilevers, or combinations thereof. The springs may have a cantilever action, a torsional force, or a combination thereof. The MEMS region located directly above the metal actuator electrode moves vertically due to electrostatic force. This force attracts the MEMS actuator, particularly the diaphragm, and brings it closer to the metal surface. Also, the spring helps to restore the diaphragm to its original position where the tension of the spring is minimized. As shown, a gap is defined between the movable MEMS element and the metal actuation layer in the actuation region. The smaller the gap, the greater the electrostatic force acting compared to when the gap is large. The actuator gap is designed based on the desired movement of the MEMS, the desired electrostatic force, and the damping force.

[0021] In one example, the MEMS diaphragm in the speaker region may also be connected to a specific voltage. The voltage is designed such that the electrostatic force is maximized or controlled at a desired level. In one example, the diaphragm is composed of a silicon material of appropriate thickness that operates to cause the movement of air to generate an acoustic signal. This thickness is suitable for enabling deflection and operation at specific velocities and accelerations.

[0022] When an electrostatic force is applied from a metal plate or electrode on the CMOS die, the MEMS actuator region within the actuation region is electrostatically attracted towards the metal plate and, if the force is an attractive force, is thereby pulled down. When the electrostatic force from the metal actuator disappears, the diaphragm moves upward.

[0023] In this example, the cap wafer (shown at the top) or the surface layer inside it (e.g., metal) may also be driven by a voltage proportional to the audio voltage that drives the speaker. If designed such that the distance between the cap and the actuator layer from the CMOS actuation region is the same, the force applied to the actuator layer will be proportional to the applied voltage. By applying electrostatic actuation from both the cap side and the CMOS side, the total force can be increased and movement of the actuator in both directions becomes possible. In one example of this invention, the cap wafer can be a silicon-on-insulator (SOI) substrate where the outer surface is not connected to a potential (or signal) and the SOI silicon is driven by a signal. In another example, the cap wafer comprises a metal actuator electrode that is driven by a voltage to attract the diaphragm. The cap wafer generates an electrostatic force similar to that of the CMOS actuator layer but with the opposite phase.

[0024] The vertical up-and-down movement of the diaphragm is proportional to the audio signal applied to the MEMS speaker cell. Due to this up-and-down movement, air is pushed out to pass through the MEMS cap with holes, thereby generating and propagating sound waves.

[0025] In one example, the diaphragm can be composed of a suitable material such as silicon, graphene, or a combination of different materials. Due to the vertical movement of the diaphragm, air is pushed up through the MEMS cap with holes. The movement of the diaphragm and the air pressure transmitted to the external environment are proportional to the audio input, thereby functioning as a speaker actuated by an electrode coupled to the actuator layer.

[0026] In one example, the device has a baffle(s) configured at the inner edge portion within the actuator gap. This baffle prevents the air pressure at the back from mixing with the sound waves at the front, causing noise and interference.

[0027] An additional protective material such as a barrier against electrical conductivity, moisture, water, or dust particles may be provided on the upper part of the cap, but allows sound waves to pass through.

[0028] In one example, the spring constant, dimensions of the beam connecting to the actuator layer acting as a piston, and the area and mass of the diaphragm can be designed to obtain MEMS resonance at a desired frequency. At the resonance frequency, the movement of the diaphragm is maximum or the desired movement. On the other hand, by optimizing (or adjusting) the dimensions and mass, a flatter frequency response can be obtained for a desired frequency bandwidth.

[0029] As shown in the figure, the cap layer, actuator layer, and CMOS layer are joined to each other using a bonding process.

[0030] Figure 2 is a simplified explanatory diagram showing the movement of a diaphragm by electrostatic actuation according to an example of the present invention. The dashed, dotted, and solid lines of the actuator layer represent displacements at different spatial levels from the original position after electrostatic actuation is applied from the electrode layer. The vertical up-and-down movement of the diaphragm is proportional to the audio signal applied to the MEMS speaker cell. Due to the up-and-down movement, air is pushed out through the MEMS cap with holes, thereby generating sound waves.

[0031] Figure 2 shows how the movable diaphragm is connected to the frame of the microspeaker device and an example of a spring used in different spatial orientations. The diaphragm can be manufactured from a suitable material such as silicon, graphene, metal, or a combination of different materials. Due to the vertical movement of the diaphragm, air is pushed up through the MEMS cap with holes. Due to the movement of the diaphragm and air pressure, sound waves proportional to the audio input are transmitted to the external environment, functioning as a speaker device.

[0032] In one example, a baffle is added to prevent the back air pressure from mixing with the front air waves. Also, the baffle protects the MEMS layer and silicon from external particles entering the internal region of the speaker device.

[0033] In one example, this device can include one or more holes in the diaphragm to mitigate squeeze film damping and increase the resonance frequency and bandwidth of the speaker. Also, these holes are useful in a specific process for manufacturing the speaker.

[0034] Figure 3 is a schematic diagram showing an example of a top view of a diaphragm with a spring and a cantilever according to the present invention. Although a rectangular diaphragm is shown, other shapes are possible. Each side is connected to a spring device or a cantilever device fixed to an outer frame structure. Since there can be several other optimized configurations for the shape and size of the cantilever, spring, and diaphragm, the dimensions and arrangements shown in Figure 3 are shown for illustrative purposes only.

[0035] Figure 4 shows an example of additional electrodes formed on the CMOS layer and the cap layer. The electrodes marked "sense electrodes" are used to track the capacitance changes caused by the displacement of the diaphragm and the MEMS proof mass. In an Application Specific Integrated Circuit (ASIC), the capacitance changes can be tracked to sense the exact positions of the MEMS proof mass and the diaphragm. The generated electrical signal may be proportional to the displacement of the MEMS proof mass and can be used for attenuation or nonlinearity compensation control.

[0036] Figure 5 is a perspective view showing an example of an encapsulation or cap layer. The cap layer is provided with one or more vents for coupling the sound pressure to the medium outside the encapsulation and allowing the sound wave to pass through. The encapsulation layer also functions as a barrier against dust and other obstacles. In an example of the present invention, the cap layer or additional encapsulation adds a material with a barrier against moisture, water, and dust particles while allowing the sound wave to pass through.

[0037] FIG. 6 is a schematic diagram showing a speaker array in which a plurality of such speaker cells are arranged adjacent to each other. For example, speaker cell C1 in FIG. 6 has a resonant frequency at frequency F1, and cell C2 has a resonant frequency at frequency F2, and so on. The final frequency response of the combined system can be optimized (or adjusted) to achieve an overall broadband frequency response or to boost in a band of interest.

[0038] FIG. 7 is a schematic diagram showing a method of optimizing (or adjusting) a plurality of speaker cells to create an audio “equalizer”. Each cell or plurality of cells can be optimized to cover the frequency response of the bass, midband, and treble frequency ranges. The user can adjust the equalizer to a desired setting that includes one of a plurality of parameters.

[0039] FIG. 8 is a diagram showing a CMOS ASIC that is monolithically integrated with a microphone in one example. The ASIC has an audio preprocessing function. The preprocessing function optimizes (or processes) the signal supplied to the electrodes, thereby achieving a desired frequency response from the microphone device. The preprocessing function may also include wireless connectivity such as Bluetooth (registered trademark).

[0040] The method of manufacturing the device starts with conventional silicon and MEMS process technologies. In one example, in the manufacturing process according to the present invention, Silicon On Insulator (SOI) can be used to fabricate the diaphragm layer. The SOI wafer can be thinned to the desired thickness of the diaphragm. Germanium is sputtered and etched to define a surface for fusion bonding with another CMOS wafer. Next, the actuator is etched by Deep Reactive Ion Etch (DRIE) to define MEMS elements including the actuation area, the beam area, and the spring. Thereafter, the processed SOI wafer is fusion bonded to the CMOS wafer. The CMOS wafer has ASIC functions fabricated thereon, and the top metal surface of the desired actuation area is also fabricated to function as the actuation electrode. Thereafter, the etching of the diaphragm is relaxed to allow its movement. Additional bottom etching may be performed at the bottom of the CMOS to create vent holes. Of course, those skilled in the art will recognize other variations, modifications, and alternatives. The details of the method are described in more detail throughout this specification and below.

[0041] FIG. 9A is a schematic diagram showing the starting point of the process, which is (i) a bottom - unprocessed CMOS wafer, (ii) a middle - SOI wafer with a thin silicon on top of the upper insulator (silicon dioxide) and the lower silicon substrate, and (iii) an upper - unprocessed cap wafer. In one example, each wafer can be made using silicon material, but other materials can also be used.

[0042] Figure 9B is a simplified diagram showing the processed wafer, which includes (i) a processed CMOS wafer with bottom - actuation electrodes, (ii) an SOI wafer in which the middle - first silicon layer defines a diaphragm and the second silicon layer forms a post, and a metal such as aluminum or germanium can be deposited to bond this layer to the CMOS layer and the cap layer, and (iii) an upper - cap wafer in which a cavity is etched and, as an example, a metal is deposited to function as the upper - electrode layer. As shown, the bottom wafer includes CMOS cells and a plurality of electrode devices. In one example, the bottom wafer includes functions such as edge posts. As shown in the middle SOI wafer, the device includes germanium deposited for bonding to the bottom CMOS wafer and also includes germanium material for bonding to the cap wafer. The cap wafer includes a recessed region for forming a cavity. Of course, there can be other variations, modifications, and alternatives.

[0043] Figure 9C is a simplified diagram showing the processed microphone. It is (i) a processed CMOS wafer with bottom - actuator electrodes, which is joined to the middle SOI wafer. In the middle SOI wafer, etching is performed to release the diaphragm layer and it is further joined to the upper cap wafer. The cap wafer has vent holes etched in it. As shown, in one example, a plurality of substrates (e.g., bottom, middle, upper) are configured in a multi - layer bonded structure with each other. Of course, there can be other variations, modifications, and alternatives.

[0044] In one example, the present invention provides a micro-speaker device. This device has a cap device with a plurality of vent areas for propagating acoustic signals. The cap device can be made from a suitable material such as silicon or other rigid substrates that can be processed. In one example, the device includes a CMOS device coupled to the cap device. In one example, the CMOS device has at least one vent area configured such that back pressure flows therethrough. The CMOS device can be a CMOS semiconductor substrate including a plurality of CMOS cells. This device has a cavity area configured between the inner surface of the cap of the cap device and the inner surface of the CMOS of the CMOS device. This device has a frame device coupled between the cap device and the CMOS device to form an external housing of the cavity area. In one example, the frame device can be configured on either or both of the cap device and / or the CMOS device.

[0045] In one example, the device has a movable diaphragm device made of a silicon or graphene material having a thickness from 0.1 nm to 10 microns and spatially arranged in an elongated shape within the cavity area. In one example, the movable diaphragm device has a first surface and a second surface opposite the first surface. In one example, the movable diaphragm is connected to at least two cantilevers or springs. Each of the cantilevers or springs is coupled between a peripheral area of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device.

[0046] In one example, the device has a CMOS electrode device configured on the internal area of the CMOS device. That is, the CMOS device has one or more electrode devices formed on the internal area of the CMOS device.

[0047] In one example, the device has a cap electrode device configured on the inner surface of the cap, and each of the cap electrode device and the CMOS electrode device electrostatically operates a movable diaphragm by a gravitational action in response to an applied electrical signal, causing movement of the diaphragm and allowing an acoustic signal to propagate from one or more of a plurality of vent regions within the cap device.

[0048] In one example, the electrode generates an electrostatic force that moves a movable diaphragm device from a first spatial region within the cavity to a second spatial region, and is configured in a shape other than planar simultaneously with the movement.

[0049] In one example, the movable diaphragm device includes one or more self - supporting peripheral regions. In one example, the cavity region includes a first region facing a first surface and a second region facing a second surface. In one example, the cap device includes a plurality of vent regions configured to block the entry of particles into the cavity region but allow the passage of sound pressure. In one example, the cap device includes an insulating material that electrically insulates the actuation voltage from the cap device and a metallic material stacked thereon. In one example, the movable diaphragm device is connected to the frame device on both sides thereof.

[0050] In one example, the device is characterized by a frequency response associated with the mass of the movable diaphragm device and the spring constant of the spring to achieve resonance at a desired frequency.

[0051] In one example, the device further includes a voltage potential configured between the cap electrode device and the movable diaphragm device to apply an electrostatic force to the movable diaphragm device. In one example, the device includes one or more baffles within the cavity region to prevent the propagation of one or more acoustic waves from a first surface to a second surface of the movable diaphragm device.

[0052] In one example, the device has at least one sense electrode configured on a cap device to track the position of a movable diaphragm device. In one example, the device has at least one sense electrode that detects the position of the movable diaphragm device and provides feedback for controlling non-ideal operation of the movable diaphragm device. In one example, the device comprises at least one sense electrode that provides feedback for applying electrostatic damping to the movable diaphragm device.

[0053] In one example, each of the springs includes one or more cuts provided in the diaphragm.

[0054] In one example, the present invention provides an alternative speaker device. The device comprises a CMOS substrate having a first surface region and a second surface region. The first surface region is on the opposite side of the second surface region. In one example, the first surface region is either the front surface or the back surface, and the second surface is the back surface or the front surface.

[0055] In one example, the device comprises an N×M array of microspeaker cells configured on a CMOS substrate, where N and M are each integers greater than or equal to 1. Each of the cells may have the same or different configurations, or may be composed of cells of the same or different sizes to generate a desired audio signal. Each of the microspeaker cells comprises a cap device having a plurality of vent regions for propagating an acoustic signal, a cavity region configured between the inner surface of the cap of the cap device and the inner surface of the CMOS of the CMOS device, and a frame device coupled between the cap device and the CMOS device to form an outer housing of the cavity region.

[0056] Each of the cells has a movable diaphragm device that has a thickness of silicon or graphene material from 0.1 nm to 10 microns and is spatially elongated within the cavity region. The movable diaphragm device has a first surface and a second surface facing the first surface. The movable diaphragm is connected to at least two cantilevers or springs. Each of the cantilevers or springs is coupled between a peripheral region of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device.

[0057] Each of the cells has a CMOS electrode device configured on an internal region of the CMOS device. Further, each of the cells has a cap electrode device configured on an internal surface of the cap, whereby each of the cap electrode device and the CMOS electrode device can electrostatically operate the movable diaphragm using a pull action and propagate an acoustic signal from one or more of a plurality of vent regions within the cap device.

[0058] In one example, an array of micro speaker cells is configured to generate a wider bandwidth and flatter frequency response. In one example, an array of micro speaker cells is configured to move the movable diaphragm device in different phases to generate a desired acoustic signal. In one example, an array of micro speaker cells is configured to perform frequency boosting in a desired single or multiple frequency bands and to create an audio equalizer including a bass range, a midrange, and a treble range.

[0059] In one example, a CMOS device includes a preprocessor for processing an audio signal output to an array of microspeaker cells. Further, the device includes a module having an adjustment process for customizing for an individual or an individual ear for a desired acoustic experience. In one example, the array of cells is configured on a single CMOS substrate or a single cap region. In one example, the device further includes a single encapsulation region coupled to one or more microspeaker cells.

[0060] In one example, the present invention provides a microelectromechanical system. The system includes a movable diaphragm device configured on a semiconductor substrate, having a thickness of a silicon or graphene material, and spatially configured in an elongated shape within a cavity region. The movable diaphragm device has a first surface and a second surface opposite the first surface. The movable diaphragm is connected to at least two cantilevers or springs. Each of the cantilevers or springs is coupled between a peripheral region of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device. The system includes an electrode device coupled to the movable diaphragm device and configured to electrostatically move the movable diaphragm using a pull action that causes movement of the diaphragm in response to an applied electrical signal and to propagate an acoustic signal from one or more of a plurality of vent regions within the cap device.

[0061] In one example, an electrostatic force is applied to the cap device and the CMOS electrodes using a charge proportional to the acoustic signal.

[0062] The above is a complete description of specific examples, but various modifications, alternative structures, and equivalents may be used. For example, a packaged device may include any combination of the above elements and elements outside the scope of this specification. Accordingly, the above description and figures should not be construed as limiting the scope of the invention defined by the appended claims.

Claims

1. A microspeaker device, comprising: A cap device including at least one vent area for propagating an acoustic signal; A CMOS device coupled to the cap device, the CMOS device including at least one vent area or cavity configured such that back pressure flows therethrough; A cavity area configured between the inner surface of the cap of the cap device and the inner surface of the CMOS device of the CMOS device; A frame device coupled between the cap device and the CMOS device, forming an exterior housing of the cavity area; A movable diaphragm device having a thickness of silicon or graphene material, configured to be elongated and spatially within the cavity area, having a first surface and a second surface opposite the first surface, and connected to at least two cantilevers or springs, each of the cantilevers or springs being coupled between a peripheral area of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device; A CMOS electrode device configured within an internal area of the CMOS device; A cap electrode device configured on the inner surface of the cap, each of the cap electrode device and the CMOS electrode device being operable to electrostatically move the movable diaphragm using a pull action in response to an applied electrical signal, causing movement of the diaphragm and causing propagation of an acoustic signal from one or more of a plurality of vent areas within the cap device; A microspeaker device comprising the above.

2. The device according to claim 1, wherein the electrodes provide an electrostatic force for moving the movable diaphragm device from a first spatial area within the cavity to a second spatial area, configured in a shape other than planar simultaneously with the movement, and the thickness of the silicon or graphene material is from 0.1 nm to 10 microns.

3. The device according to claim 1, wherein the movable diaphragm device includes one or more peripheral areas that are self - supporting.

4. The device according to claim 1, wherein the frequency response of the device is adjusted by changing the dimensions of the springs and the mass of the diaphragm to achieve acoustic resonance at a desired frequency.

5. The device according to claim 1, further comprising a voltage potential configured between the movable diaphragm device and the cap surface or the CMOS surface to apply an electrostatic force to the movable diaphragm device.

6. The device according to claim 1, wherein the electrostatic force is applied to the cap device and the CMOS electrode using a charge proportional to an acoustic signal.

7. The device according to claim 1, further comprising at least one sense electrode configured on the cap device to track the position of the movable diaphragm device or to control non-ideal behavior of the movable diaphragm device.

8. The device according to claim 1, further comprising at least one sense electrode that provides feedback for applying electrostatic damping to the movable diaphragm device.

9. The device according to claim 1, wherein each of the springs has one or more cuts in the diaphragm.

10. A speaker device, a CMOS substrate having a first surface region and a second surface region, the first surface region being located on the opposite side of the second surface region, a CMOS substrate, an N×M array (where N and M are each an integer of 1 or more) composed of microspeaker cells configured on the CMOS substrate, comprising, each of the microspeaker cells a cap device having a plurality of vent regions for propagating an acoustic signal, a cavity region configured between the inner surface of the cap of the cap device and the inner surface of the CMOS device of the CMOS device, a frame device coupled between the cap device and the CMOS device to form an outer housing of the cavity region, a movable diaphragm device having a thickness of a silicon or graphene material and configured elongated and spatially within the cavity region, the movable diaphragm device having a first surface and a second surface opposite the first surface, the movable diaphragm being connected to at least two cantilevers or springs, each of the cantilevers or springs being coupled between a peripheral region of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device. A CMOS electrode device configured in the internal region of the CMOS device, and A cap electrode device configured on the inner surface of the cap, wherein each of the cap electrode device and the CMOS electrode device is operable to electrostatically move the movable diaphragm using a pull action, thereby causing the propagation of an acoustic signal from one or more of a plurality of vent regions within the cap device. A cap electrode device, A speaker device comprising the same.

11. The device according to claim 10, wherein the array of microspeaker cells is configured to produce a wider bandwidth frequency response and a desired sound pressure intensity.

12. The device according to claim 10, wherein the array of microspeaker cells is configured to move the movable diaphragm device in different phases to generate a desired acoustic signal.

13. The device according to claim 10, wherein the array of microspeaker cells is configured to generate a frequency boost in a desired single or multiple frequency bands, and is configured to generate an audio equalizer including frequencies in a bass range, a midrange, and a treble range.

14. The device according to claim 10, wherein the CMOS device includes a preprocessor for processing an audio signal output to the array of microspeaker cells.

15. The device according to claim 10, further comprising a module coupled to the device for adjusting one or more characteristics of one or more of the microspeaker cells to achieve a desired acoustic experience.

16. A microelectromechanical system, A movable diaphragm device configured on a semiconductor substrate, consisting of the thickness of a silicon or graphene material, and spatially configured in an elongated shape within a cavity region, comprising a first surface and a second surface opposite to the first surface, and coupled to at least two cantilevers or springs, each of the cantilevers or the springs being coupled between a peripheral region of the movable diaphragm device and a part of a frame configured to surround the movable diaphragm device. A movable diaphragm device, An electrode device coupled to the movable diaphragm device and configured to electrostatically move the movable diaphragm using a pull action to cause movement of the diaphragm in response to an applied electrical signal and to cause propagation of an acoustic signal from one or more of a plurality of vent regions within the cap device. A microelectromechanical system comprising the same.

Images