Method for manufacturing an air pulse generation device

Abstract

This invention provides a method for manufacturing an air pulse generation device that generates asymmetric air pressure pulses. [Solution] A method for manufacturing an air pulse generating device 200 that generates multiple air pulses by activating a film structure includes the steps of: providing a wafer having a first layer and a second layer; patterning the first layer of the wafer to form a slit 212 having a zigzag pattern; and removing a first portion of the second layer. The portion of the first layer above the removed first portion of the second layer forms a film structure. The slit having the zigzag pattern separates the film structure into a first flap and a second flap. The slit having the zigzag pattern folds back and forth in a zigzag pattern between a first direction and extends toward a second direction.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an air-pulse generating device, and more specifically, to a method for manufacturing an air-pulse generating device capable of generating asymmetric air pressure pulses. [Background technology]

[0002] Traditionally, speaker drivers and back enclosures have been two major design challenges in the speaker industry. It is difficult for a single conventional speaker (such as a dynamic driver) to cover the entire frequency range, for example, from 20 Hz to 20 kHz. To produce high-fidelity sound at a sufficiently high sound pressure level (SPL), conventional speakers require both a sufficiently large radiating / moving surface and a sufficiently large volume / size of the back enclosure.

[0003] U.S. Patents 9,736,595 and 10,367,430 discuss ultrasonic pulses for sound-producing applications. Furthermore, to address the bandwidth and size issues mentioned above, the applicant discloses APG (Air Pulse Generator) devices or APPS (Air Pressure Pulse Speaker) in U.S. Patents 10,425,732, 11,172,310, 10,425,732, 11,043,197, and 11,445,279.

[0004] However, the performance of APPS depends on the asymmetry of the air pressure pulse generated by the APG device. [Prior art documents] [Patent Documents]

[0005] 1. United States Patent No. US9,736,595 B2 2. U.S. Patent No. US9,516,421B1 3. U.S. Patent No. US4,364,147A 4. U.S. Patent Application Publication No. US2022 / 0225032 A1 5. U.S. Patent Application Publication No. US2020 / 0087138 A1 6. U.S. Patent Application Publication No. US2019 / 0313189 A1 7. U.S. Patent Application Publication No. US2018 / 0098139 A1 8. U.S. Patent Application Publication No. US2017 / 0041708 A1 9. U.S. Patent Application Publication No. US2017 / 0021391 A1 10. U.S. Patent Application Publication No. US2014 / 0341394 A1 11. U.S. Patent Application Publication No. US2014 / 0084396 A1 12. U.S. Patent Application Publication No. US2012 / 0053393 A1 13. U.S. Patent Application Publication No. US2012 / 0018244 A1 14. U.S. Patent Application Publication No. US2004 / 0024455 A1 15. U.S. Patent Application Publication No. US2003 / 0017012 A1 16. U.S. Patent No. US10,771,893 B1 17. United States Patent No. US10,284,960 B2 18. U.S. Patent Application Publication No. US2023 / 0292058 A1 19. U.S. Patent Application Publication No. US2022 / 0224999 A1 [Overview of the project]

[0006] Therefore, the primary objective of this application is to improve upon the shortcomings of the prior art by providing an APG device capable of generating asymmetric air pressure pulses.

[0007] One embodiment of the present disclosure provides a method for manufacturing an air pulse generating device. The method for manufacturing the device includes the steps of: providing a wafer having a first layer and a second layer; patterning the first layer of the wafer to form a slit having a zigzagging pattern; and removing a first part of the second layer. A portion of the first layer above the removed first part of the second layer forms a film structure. The slit having the zigzagging pattern separates the film structure into a first flap and a second flap. The slit having the zigzagging pattern zigzags in a back-and-forth manner among a first direction and extends toward a second direction. An air pulse generation device generates a plurality of air pulses by actinguating the film structure.

[0008] These and other objectives of the present invention will be undoubtedly apparent to those skilled in the art upon reading the following detailed description of preferred embodiments illustrated in various figures and drawings. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of an air pulse generation (APG) device. [Figure 2] The wiring configuration of the APG device is shown in the diagram. [Figure 3] The modulated signal and demodulated signal are illustrated in the diagram. [Figure 4A] A cross-sectional view of the APG device is shown. [Figure 4B] Figure 4A shows a top view of the APG device. [Figure 4C] Figure 4B illustrates the direction of airflow when the virtual valve (VV) of the APG device opens. [Figure 5A] This figure shows a cross-sectional view of an APG device according to one embodiment of this application. [Figure 5B] This figure shows a cross-sectional view of an APG device according to one embodiment of this application. [Figure 5C] Figures 5A and 5B show top views of the APG device. [Figure 5D] Figure 5C illustrates the direction of airflow when the virtual valve (VV) of the APG device opens. [Figure 6] Figure 5C illustrates the first and second flaps of the separated APG device. [Figure 7] Figure 5C illustrates the common mode motion of the first and second flaps of the APG device. [Figure 8] Figure 5C illustrates the differential mode movement of the first and second flaps of the APG device. [Figure 9A]Figures 4 and 5 illustrate the common-mode displacement and differential-mode acoustic conductance of the APG device in combination. [Figure 9B] Figures 4 and 5 illustrate the combination of common-mode displacement for common-mode motion and acoustic conductance for differential-mode motion for the APG device. [Figure 10A] Figure 5C illustrates the relationship between common mode displacement and porosity of an APG device according to one embodiment of this application. [Figure 10B] Figure 5C illustrates the relationship between virtual / effective common mode displacement and porosity of an APG device according to one embodiment of this application. [Figure 11] This document illustrates an APG device according to one embodiment of this application. [Figure 12] This document illustrates the common-mode and differential-mode motions of an APG device within a single cycle according to one embodiment of this application. [Figure 13A] The relationship between common-mode displacement and common-mode acceleration and porosity of an APG device according to one embodiment of this application is illustrated in combination. [Figure 13B] The relationship between common-mode displacement and porosity of an APG device according to one embodiment of this application is illustrated in combination. [Figure 13C] The relationship between common-mode displacement and porosity of an APG device according to one embodiment of this application is illustrated in combination. [Figure 14] This document illustrates an APG device according to one embodiment of this application. [Figure 15]This document illustrates an APG device according to one embodiment of this application. [Figure 16] This invention illustrates a method for manufacturing an APG device / a process for manufacturing an APG device, according to one embodiment of this application, with configurations at multiple different stages of the process. [Figure 17] This invention illustrates a method for manufacturing an APG device / a process for manufacturing an APG device, according to one embodiment of this application, with configurations at multiple different stages of the process. [Figure 18] This invention illustrates a method for manufacturing an APG device / a process for manufacturing an APG device, according to one embodiment of this application, with configurations at multiple different stages of the process. [Figure 19] This invention illustrates a method for manufacturing an APG device / a process for manufacturing an APG device, according to one embodiment of this application, with configurations at multiple different stages of the process. [Figure 20] This invention illustrates a method for manufacturing an APG device / a process for manufacturing an APG device, according to one embodiment of this application, with configurations at multiple different stages of the process. [Modes for carrying out the invention]

[0010] The contents of U.S. Patent No. US 11,943,585 B2 and U.S. Patent Application No. 18 / 624,105 are incorporated herein by reference.

[0011] The air pulse generating device in this application generally includes a pair of opposing flaps, which are fabricated by etching a membrane layer made of, for example, SOI (silicon on insulator), POI (poly on insulator), or other suitable material. By adding a layer of piezoelectric material such as PZT deposited on the pair of flaps, the pair of opposing flaps are operated to move up and down, generating both common-mode motion and differential-mode motion, respectively, which perform modulation and demodulation functions.

[0012] Specifically, Figure 1 is a cross-sectional view of an air pulse generation (APG) device 100. The APG device includes a membrane structure 10 (for example, a membrane or a diaphragm). The membrane structure 10 includes flaps 101 and 103 facing each other. The operating principle of the APG device 100 is similar to the operating principle of the APG device disclosed in U.S. Patent No. 11,943,585 B2. The flaps 101 and 103 (formed as a flap pair 102) are actuated to perform common-mode motion to form an amplitude-modulated ultrasonic air pressure variation at an ultrasonic frequency (for example, 192 kHz), and the formation of the amplitude-modulated ultrasonic air pressure variation may be considered a modulation operation. Meanwhile, flaps 101 and 103 are also operated to perform differential mode motion to form an opening 112 or a virtual valve 112 (shortened to VV) at an ultrasonic opening rate (e.g., 192 kHz), thereby performing demodulation.

[0013] In the embodiment shown in the APG device 100, differential mode motion (demodulation) and common mode motion (modulation) are performed simultaneously by the flap pair 102. Certain wiring configurations allow for modulation and demodulation to occur simultaneously in place. For example, as shown in Figure 2, the APG device 100 may include actuator 101A located on flap 101 and actuator 103A located on flap 103. Actuators 101A and 103A include top electrodes and bottom electrodes. In one embodiment, the bottom electrodes of actuators 101A and 103A receive a common modulation signal SM, and the top electrodes of actuators 101A and 103A receive differential demodulation signals +SV and -SV, which have opposite polarities. It should be noted that the wiring configuration shown in Figure 2 is for illustrative purposes only and is not limited thereto. As long as one electrode of actuator 101A / actuator 103A receives a modulated signal SM and the other electrode receives a demodulated signal SV (representing either +SV or -SV), the requirements of the present invention are met, and such actuators 101A and actuator 103A fall within the scope of this application.

[0014] The waveforms of the modulated signal SM and the demodulated signal ±SV can be seen in Figure 3 (or waveforms similar to those shown in Figure 3). It should be noted that the demodulation frequency of the demodulated signal SV is half the modulation frequency of the modulated signal SM. For example, when the modulation frequency of the modulated signal SM is 192 kHz, the demodulation frequency of the demodulated signal SV will be 96 kHz. Therefore, flaps 101 and 103 form an aperture 112 with an opening rate of 192 kHz, and the APG device 100 uses an ultrasonic pulse velocity f of 192 kHz. PulseThis generates multiple air pulses.

[0015] In this application, “flaps 101 and 103 performing common mode motion” means that flaps 101 and 103 are operated to move in a common direction or are operated by a common drive signal, and “flaps 101 and 103 performing differential mode motion” means that flaps 101 and 103 are operated to move in different directions / opposite directions with respect to a common position or are operated by a differential pair of signals.

[0016] The slit 112 is formed between the flap 101 and the flap 103. In this application, "slit," "opening," and "virtual valve" share the same notation (e.g., 112) as they share the same location and represent similar concepts in different embodiments. By driving the flaps 101 and 103 with the demodulated signal ±SV, the distance between the free end of flap 101 and the free end of flap 103 is increased, forming the opening 112 or VV112. The upper portion of Figure 1 shows a snapshot of VV112 closed / sealed, and the lower portion of Figure 1 shows a snapshot of VV112 open.

[0017] The pattern of the slits 112 on the membrane structure 10 is not limited. Intuitively, the slits 112 may have a straight-line slit pattern. Figures 4A to 4C illustrate schematic diagrams of APG devices having a straight-line slit pattern. As shown in Figure 4B, the slits 112 having a straight-line slit pattern may be considered to include a zero projection onto the X direction / dimension. APG devices having a straight-line slit pattern are successful in generating asymmetric airflow pulses. However, the asymmetry of the air pressure pulses generated by APG devices having a straight-line slit pattern is not always obvious, or may even be unmeasurable. This is due to severe airflow congestion around the VV112 and airflow detouring before reaching the VV112, as shown in Figure 4C, which schematically illustrates the airflow vectors around the VV112. In some of the figures of this application, several different types of shading are used to illustrate the relationship between flap 101 and flap 103, but these several different types of shading do not mean that flap 101 and flap 103 are made of different materials.

[0018] The congestion of airflow (when VV112 is just "opening") will increase the pressure difference ΔP surrounding VV112. Here, ΔP = P A -P B P A / P BThis represents the air pressure directly above / below the plane defined by flap 101 / flap 103. Ideally, the pressure difference ΔP should be neutralized as quickly as possible when VV112 is opened. However, the neutralization of the pressure difference ΔP corresponding to a slit with a linear pattern is not fast enough. This is due to the lateral component of the airflow and airflow bypass.

[0019] As shown in Figure 4, the airflow vectors include strong lateral components (components other than those in the Z direction; in the linear slit pattern shown in Figure 4B, the lateral component represents the component parallel to the X direction), and the presence of strong lateral components means that the airflow deviates. This detour not only lengthens the airflow passageway but also slows down the reaction of pressure balance across the two sides of the flaps 101 and 103. After reaching the vicinity of VV112, the air will be queued up, waiting in turn to be squeezed through the narrow opening of VV112. All of these steps / factors contribute to their respective low-pass-filter (LPF) effects. When these factors are combined, f Pulse A powerful high-order LPF is created, which filters away the higher harmonics of f Pulse)。Since a strong asymmetric waveform means strong spectral components at high harmonics of the high frequency range, f Pulse such removal of harmonics of f Pulse implies loose of asymmetry).

[0020] Regarding the performance of the APG device, the asymmetry of the pneumatic pulse is important for both sound producing applications (which may be considered as AC (AC: Alternating Current) airflows) and air movement applications (which may be considered as DC (DC: Direct Current) airflows). It is desirable to propose a further new design of APG with the asymmetry of the pneumatic pulse.

[0021] Some of the multiple guidelines are introduced below. To avoid the convergence of the airflow, VV112 needs to be designed to cover a significant amount (or at least include a non-zero projection in the X direction / X dimension) in the X direction / X dimension. In other words, VV112 needs to cover (or occupy a significant area) a significant proportion of the total area of flap 101 and flap 103. For example, VV112 may cover / occupy 20 - 40% (or at least 15%) of the total area of flap 101 and flap 103, but is not limited thereto.

[0022] In addition, to minimize the lateral component when VV is "opened", the acoustic impedance of VV needs to be distributed in the X direction in a substantially uniform manner, so that the air will flow straight through VV (mainly through the Z direction). The amplitude of the combined common mode displacement U Z.COM (x) of a combined common mode displacement U Z.COMIt is suggested that (x) is distributed in the X direction in a nearly uniform manner. Z.COM (x) is the combination / aggregation of the common mode displacements of flaps 101 and 103. For example, U Z.COM (x) is U Z.COM (x=(w 101 (x)·ΔU z,101 (x) + w 103 (x)·ΔU z,103 (x)) / (w 101 (x) + w 103 It can also be expressed as (x), ΔU z,101 (x) / ΔU z,103 (x) represents the individual common mode displacements of flap 101 / flap 103 (corresponding to the X-dimensional variable x), and w 101 (x) / w 103 (x) represents the corresponding weighting factor. In one embodiment, but not limited to these, w 101 (x=w 103 (x) = 0.5.

[0023] One solution to avoid airflow congestion and minimize the lateral component is to pattern / form the slits in a zigzag pattern on the film structure. In this application, a slit with a zigzagging pattern may mean that (1) the slit is not straight-line, (2) the slit alters / changes its direction in a back-and-forth manner, and (3) the slit has a nonzero projection onto the X direction / dimension in a top view perspective when patterned to zigzag in a back-and-forth manner among X direction and extend toward Y direction. The projection of a zigzagging patterned slit into the X direction / X dimension may have a length / depth that is a significant percentage (for example, greater than 15%) of the anchor-to-anchor distance of the flaps 101 and 103 or the APG device.

[0024] Referring to Figures 5A to 5D, Figures 5A to 5D illustrate an APG device 200 according to one embodiment of the present invention, Figure 5C shows a top view of (part of) the zigzag pattern of the slit 212, Figures 5A and 5B show cross-sectional views along lines A-A' and B-B' when the flaps 101 and 103 are kept flat (or the VV212 is closed), and Figure 5D schematically shows the airflow vector along line D-D' in Figure 5C when the VV212 having a zigzag pattern is opened.

[0025] The width of the APG device 200 (such as its dimension / size in the Y direction) is not limited to the width shown in Figure 5C. The APG device 200 may include wide cantilevers, which means that the width of the APG device 200 may be several times greater than its length (such as its dimension / size in the X direction). In other words, in one embodiment, flaps 101 and 103 may extend in the Y direction and have relatively extreme aspect ratios (for example, greater than 2 or less than 1 / 2).

[0026] The slit 212 may have a tooth edge pattern. Specifically, Figure 6 illustrates flap 101 separated from flap 103, which has a tooth-patterned edge. As shown in Figure 6, flap 101 / flap 103 includes protruded parts (protrusions) 220 / 240 and depressed parts (depressions) 222 / 242. The protruded parts 220 and depressed parts 240 are interleaved with each other. When flaps 101 and 103 are separated only by the slit 212 (as shown in Figures 5C and 6), the recess 242 of flap 103 accommodates the projection 220 of flap 101, and the recess 222 of flap 101 accommodates the projection 240 of flap 103, thereby the projections 220 of flap 101 and 240 of flap 103 are arranged alternately. Furthermore, in Figure 5C, the slit 212 has, as one example, a rectangular tooth edge pattern.

[0027] From Figure 5C, the slit 212 is not straight-line, but alters its direction in a back-and-forth manner. The slit 212 is X 103L and X 101R It is zigzagging back and forth along the X direction between X and X. 103L and X 101R) and can also be considered to be extending toward the Y direction (shown in Figure 5C) tooth depth D T , in other words, X 103L and X 101R The distance between them is X 101L and X 103R The distance between anchors (anchor-to-anchor distance) d AA This may be a specific percentage (for example, greater than 15% or between 20% and 40%), and the flaps 101 and 103 of the APG device 200 will be fixed to an anchor structure in the same way as the APG device 100, but the anchor structure is omitted in Figure 5 for simplicity.

[0028] In addition, the recessed portion 222 of the flap 101 (or, ignoring the slit width, the protruding portion 240 of the flap 103) has a width W T It may have a width W T This also refers to the length of segment 231. In Figure 5C, W T This may be considered to be the width of the projection of the flap 103. In one embodiment, in order to effectively reduce acoustic resistance, its width W T (Although not limited to these) W T ≥1.5 × H slit or W T ≥1.5 × U Z_open It may be selected in such a way that H slit This represents the height of the opposing walls between flap 101 and flap 103, and is typically defined by the thickness of the membrane structure, U Z_open This represents the displacement difference between the free ends of flaps 101 and 103 in the Z direction when VV212 is opened. T ≥H slit or W T ≧U Z_open As long as this condition is met, the requirements of this application will be satisfied and it will fall within the scope of this application.

[0029] Length W T Due to the line segment 231 having a flat top (also indicated as 231) for the protruded parts of the flap 103, and a flat bottom (also indicated as 231) for the depressed part of the flap 101. The flat top of the protruded part of the flap 101 / flap 103 is advantageous in reducing acoustic resistance (compared to the case of a protrusion with a sharp tip), and the flat bottom of the flap 101 / flap 103 is advantageous in increasing the effect of increasing the slit length to reduce acoustic resistance between teeth (compared to the case of a depression with a recessed sharp tip). Generally, slits may be patterned to reduce acoustic resistance compared to slits having a saw-shaped / sinusoidal pattern, thereby allowing the projections of flaps 101 / flaps 103 to have a plateau (e.g., 231).

[0030] It should be noted that slit 212 in Figure 5C includes a non-zero projection in the X direction to the X dimension, i.e., onto line segment 232. In contrast, slit 112 in Figure 4B appears to have zero projection in the X direction to the X dimension, geometrically or in top view perspective. Furthermore, slit 212 is longer than slit 112.

[0031] When flaps 101 and 103 are operated to perform differential mode motion, the slit 212 lengthens, and the fact that the slit 212 includes a non-zero projection into the X-direction / X-dimension significantly reduces the acoustic impedance and lateral airflow component. The airflow is X 103L and X 101R It flows through the region between them. Furthermore, as can be seen from Figure 5D, the direction of the airflow may be approximately perpendicular to the XY plane, which is the plane defined by flaps 101 and 103. As a result, the pressure difference ΔP will be neutralized much faster (when VV112 is open) compared to when VV212 is open.

[0032] Figures 7 and 8 illustrate the time series of common mode displacements and differential mode displacements, respectively. CYC t refers to the cycle time. In one embodiment, t CYC = 1 / f Pulse Therefore, since the two time series cannot actually exist separately (for example, in time-division operation), these two time series are for illustrative purposes only and will be combined with one motion of flap 101 and the other motion of flap 103 by the wiring configuration shown in Figure 2. For further details, refer to U.S. Patent No. 11,943,585 B2 and the references therein, which are incorporated herein by reference.

[0033] As shown in Figure 8, (n+1 / 8)·t CYC ~(n+3 / 8)·t CYCDuring this time, VV212 is considered to be in an "open" state, and the region outlined by segments 231 to 232 is considered to be "highly porous", "acoustically translucent", and "non-pressurizing", and that region is (n+1 / 8)·t CYC ~(n+3 / 8)·t CYC During this time period, the common-mode motion of flaps 101 and 103 yields the smallest ΔP, meaning that the common-mode motion of flaps 101 and 103 is effectively "made vanish."

[0034] Conversely, (n+5 / 8)·t CYC ~(n+7 / 8)·t CYC During this time, VV212 is considered to be in a "closed" state, and the region outlined by segments 131-132 is considered to be "non-porous", "acoustically opaque", and "pressurizing", and in that region, flaps 101 and 103 are (n+5 / 8)·t CYC ~(n+7 / 8)·t CYC This means that, within this time period, it is treated as a continuous thin film, and can behave like a single (perfect thin film) in terms of the motion and acceleration of the thin film.

[0035] To make it easier to understand, when the difference in displacement between flap 101 and flap 103 is less than (or equal to) the thickness of the membrane structure, i.e., ΔU Z When ≤Hslit, VV (for example, 112 or 212) is in a closed state, and ΔU Z =|U Z,101 -U Z,103 | and U Z,101 / 103VV represents the vertical (Z-direction / Z-dimensional) displacement of the flap 101 / flap 103. It should be noted that in the APG device of this application, the closed state of VV occurs at transitions of the differential mode movement of flaps 101 and 103. In other words, VV closes while flap 101 is moving in a first direction (e.g., downward) and flap 103 is moving in a second direction opposite to the first direction (e.g., upward), thereby reducing the displacement difference (ΔU) between the free ends of flaps 101 and 103. Z ) is the thickness H of the film structure slit It becomes smaller than that. In short, both flaps are in motion when the virtual valve is closed.

[0036] Figures 9A and 9B show the common-mode and differential-mode motions of the APG device 200 repeated many times, respectively. In addition, Figure 9A shows the combined common-mode displacement U with respect to x, a variable in the X dimension, when both flaps are operated in common mode. Z.COM Figure 9B illustrates (x), and shows the acoustic conductance 1 / Z with respect to x when both flaps are operating in differential mode. VV Illustrate Z VV This represents the acoustic impedance of VV.

[0037] From Figure 9A, the common mode displacement U corresponding to VV212 is shown in the combined diagram. Z.COM (x) is compared to the distribution corresponding to VV112, X 103L and X 101R It is possible to understand that the acoustic impedance Z is uniformly distributed across the X dimension between them. From Figure 9B, VV X 103L and X 101R Within the range between X 103L and X 101RIt is possible to understand that it is distributed almost uniformly in the X dimension between them. (For example, like slit 212, etc.) An APG device having a zigzag-shaped slit can avoid the convergence of the air flow and succeed in minimizing the lateral component, and thus it is possible to conclude that it will bring an asymmetric air pressure pulse.

[0038] In addition, (for example, (n + 1 / 8)·t in FIG. 8 CYC ~(n + 3 / 8)·t CYC etc.) "made vanish" periods or VV opened periods should be properly synchronized and aligned to the effective displacement U Z.COM (t) as shown in FIG. 10A. By taking into account the "made vanish" periods, the physical displacement U Z.COM (t) may be converted into a sequence of virtual / effective movements UV Z.COM as shown in FIG. 10B or may be considered to be a sequence of virtual / effective movements UV Z.COM . In the case of an application for generating sound or an application of an APPS (APPS: air pressure pulse speaker), such an asymmetric virtual movement UV Z.COM may be used, for example, to generate an asymmetric pressure pulse by chamber compression. Z.COM

[0039] For example, referring to Figure 11 which illustrates a schematic diagram of the APG device 300, the APG device 300, including VV312 (which may be a zigzag-shaped slit such as VV212), includes a cap 320 (which may be called a covering structure) used to form a compression chamber 315. Following the timing diagram in Figure 10A, the pressure pulse is transmitted by chamber compression, which results in a pressure change at outlet 313, causing asymmetrical "virtual motion / effective motion" UV as illustrated in Figure 10B. Z.COM Each of the segments of (t) will be created in response to the pressure change, which will cause an acoustic wave to propagate outward at the speed of sound, creating a chain of acoustic pressure pulses.

[0040] It should be noted that the pressure pulses generated in the chamber 315 when VV312 is in a "closed" state, and the magnitude of those pressure pulses, are determined by the common-mode displacement of flaps 101 and 103 while VV312 is in its "closed" state. Conversely, during the period when VV312 / 212 is "opened," the airflow through the plates of flap 101 and flap 103 generates a fairly small ΔP due to the broadly-and-evenly distributed airflow (over VV312 / 212), minimal airflow congestion, low acoustic impedance over the VV312 / 212, and straight-and-short airflow pathways, and therefore will have only a slight effect on the net air pressure pulse generated by device 300.

[0041] Referring to FIG. 12, an alternative diagram of this common mode and differential mode interaction, which is applicable to an (indirect) pressure pulse generation method using a compression chamber, is illustrated. The differential mode motion is represented by the "porosity" value illustrated in FIG. 10A. The time (n + 1 / 8)·t (shown in FIG. 8) CYC ~(n + 3 / 8)·t CYC During, VV212 enters a state of being "highly porous", and the ΔP generated due to the common mode motion largely "leaks" through the porous surfaces. As a result, for the time period from (n + 1 / 8)·t CYC ~(n + 3 / 8)·t CYC the ΔP becomes zero or nearly zero. Therefore, the ΔP caused by chamber compression will be dominated by the "virtual / effective displacement" that occurs during the time from (n + 5 / 8)·t CYC ~(n + 7 / 8)·t CYC as illustrated in FIG. 10B.

[0042] In relation to the effect of bypassing the convergence of the air flow, it is possible to define a plurality of design metrics. In the case of slit patterning, the area coverage ratio (ACR) and the displacement coverage ratio (DCR) can be defined as follows. [Number]

[0043] In (Equation 1), A(VV) refers to the area occupied by the slit (for example, the zigzagging slit 212), and A(101+103) refers to the total area of ​​flaps 101 and 103. Assuming that the periphery of the film structure is rectangular, ACR can be further expressed as follows:

number

[0044] In this application, in particular, in (Formula 2) and (Formula 3), X 101L / X 103L This refers to the leftmost position of flap 101 / flap 103 on the X-axis, X 101R / X 103R This refers to the rightmost position of flap 101 / 103 on the X-axis. From another perspective, assuming that the outer circumference of the membrane structure is rectangular, X 101L / X 103R This refers to the position on the X-axis where the flap 101 / flap 103 is fixed (anchored), X 103L / X 101R This represents the leftmost / rightmost position of the protrusion of flap 101 / flap 103 on the X-axis.

[0045] To effectively bypass airflow congestion, it is suggested that ACR ≥ 0.25 and DCR ≥ 0.5 are, but are not limited to, these.

[0046] The pressure pulse generation method mentioned above is U Z.COM (t) or UV Z.COM This is referred to as an indirect method that utilizes the "displacement" of (t) to compress a small chamber (e.g., 315), generate a pressure pulse, and radiate such a pressure pulse through a narrow orifice (e.g., 313).

[0047] Alternatively, air pressure pulses may be generated by a direct method. Conceptually, a direct method utilizes VV (e.g., 112 or 212) to generate each pulse cycle t CYC d 2 U Z.COM (t) / dt 2 By "making vanish" a portion of the "acceleration" of flaps 101 and 103, which are represented as d 2 UV Z.COM (t) / dt 2 This generates a highly asymmetrical "virtual acceleration" for flaps 101 and 103, which are represented as follows.

[0048] In direct pulse generation methods, the pressure pulse is an asymmetrical "virtual acceleration" 2 UV Z.COM (t) / dt 2 It will be generated in response to each segment of. For example, as illustrated in Figure 13A, the pressure pulse is U Z.COM (t) is generated in response to the negative half-cycle common mode displacement and positive d 2 UV Z.COM (t) / dt 2 This would produce a positive half-cycle acoustic output. In this case, since pressure is related to acceleration, and acceleration is the double derivative of displacement, the air pressure pulse would be generated directly, compared to the indirect method in which the air pressure pulse is generated by chamber compression.

[0049] The timing alignment shown in Figure 13A is not limited to these, but U Z.COM(t) has a center-to-center alignment between the open-close states of VV (e.g., 112 or 212). For example, Figure 13B shows that the timing of the open-close states is U Z.COM Figure 13C illustrates a scenario where the timing of (t) is drawn "before" the timing of (t), while Figure 13C illustrates a scenario where the timing of the open / closed state is U Z.COM This diagram illustrates a scenario where the push occurs *after* the timing of (t). Z.COM The optimal timing alignment between (t) and the open / closed state of VV (e.g., 112 or 212) depends on the duty factor of VV or how long VV stays in its "closed" state. All variations of these operating conditions are within the scope of the present invention.

[0050] The zigzagging slit is not limited to having a rectangular tooth edge pattern. The zigzagging slit may also have a trapezoid tooth edge pattern. For example, in Figures 14 and 15, slits 412 and 512 have a trapezoid tooth edge pattern. The projection of flap 101 in Figure 14 has a base (e.g., 401) that is wider than its top (e.g., 402), while the projection of flap 101 in Figure 15 has a top (e.g., 502) that is wider than its bottom (e.g., 501). In either case, and also their variations (for example, fillets or chamfers may be formed at the corners of the rectangular-patterned / trapezoid-patterned slit projections), are within the scope of the present invention.

[0051] The APG device of the present invention may also be applied to sound generation applications as an APPS (Air Pressure Pulse Speaker), in which the multiple air pulses generated are amplitude modulated, and the envelope of these multiple air pulses (or, as shown in Figure 3, the modulated signal SM is the input signal S) IN The input signal S is generated accordingly. IN It should be noted that the input signal S is, for example, an AC (alternating current) component that can produce AC airflow, or contains an AC component. IN This may be an audio signal or may include an audio signal. The APG / APPS of the present invention may be placed in or applied to wearable sound devices such as earbuds, earphones, TWS (true wireless stereo), headphones, and hearing aids. The APG / APPS of the present invention may also function as a loudspeaker or open field speaker, but is not limited to these, and such loudspeaker or open field speaker may be placed in an OWS (open wearable stereo), telephone (such as a receiver or speaker), tablet, laptop, desktop monitor (for gaming / recording purposes), television, or AR / VR (augmented reality, virtual reality) device.

[0052] In addition, the APG device of the present invention may be applied to air movement applications having a function similar to that of a fan, blower, etc. Multiple air pulses are generated (or the modulated signal SM is the input signal S IN The input signal S is generated accordingly. IN The envelope of the input signal S is, for example, a DC (direct current) component that can result in a DC airflow. IN The signal may be a DC signal or may include a DC signal. The APG device of the present invention for air transport applications may, but is not limited to, be used for heat dissipation, ventilation, cooling, drying, or air quality sensing. The APG device for air transport applications is described in detail in U.S. Patent Application No. 18 / 624,105, but is not described here for brevity.

[0053] The APG device of the present invention may be manufactured by a process similar to that shown in Figures 16 to 20. Referring to Figures 16 to 20, Figures 16 to 20 illustrate the configuration of several different stages of a manufacturing method / process for manufacturing an APG device according to one embodiment of this application. Specifically, Figures 16 to 20 describe in particular detail the manufacturing process of a flap (e.g., flap 101) having an actuator (e.g., actuator 101A) in the APG device. Those skilled in the art can use the concepts provided by Figures 16 to 20 to manufacture flaps 101 and 103 having actuators 103A and actuator 101A in the APG device of this application.

[0054] It should be noted that the method for manufacturing the APG device of the present invention is not limited by the following embodiments and drawings. In some of the embodiments, any other suitable step may be added before or after one of the existing steps of the method, and / or some of the steps may be performed simultaneously or individually. In some of the embodiments, the order of the processes of the manufacturing method may be adjusted on a practical basis.

[0055] In the following manufacturing methods for APG devices, the layer and / or structure formation process may include, but is not limited to, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), coating processes, or any other suitable processes, or a combination thereof. In the following manufacturing methods for APG devices, the patterning process may include, but is not limited to, a photolithography process, an etching process, any other suitable process, or a combination thereof, and the etching process may include, but is not limited to, a wet etching process, a dry etching process, any other suitable etching process, or a combination thereof.

[0056] In the following description, the manufacturing method is not limited to these, but it is possible to manufacture APG devices having a zigzag slit pattern, such as the APG device 200 shown in Figures 5A to 5D.

[0057] In this embodiment, but not limited to these, an APG device having a zigzag-shaped slit pattern may be manufactured by at least one semiconductor process and used as a MEMS chip. As shown in Figure 16, a wafer WF is provided, which may include a first layer WL1 and a second layer WL2, and may include an insulating layer WL3 between the first layer WL1 and the second layer WL2.

[0058] The first layer WL1, the insulating layer WL3, and the second layer WL2 may individually contain any suitable material so that the wafer WF can be any suitable type. For example, the first layer WL1 and the second layer WL2 may individually contain silicon (e.g., single crystalline silicon or polycrystalline silicon), silicon compounds (e.g., silicon carbide, silicon oxide), germanium, germanium compounds, gallium, gallium compounds (e.g., gallium nitride or gallium arsenide), other suitable materials, or combinations thereof. For example, the insulating layer WL3 may contain oxides such as silicon oxide (e.g., silicon dioxide), but is not limited to these. In some of the multiple embodiments, the first layer WL1 may contain single-crystal silicon, and the insulating layer WL3 may contain an oxide, thereby the wafer WF may be a SOI wafer, but is not limited to these. In some of the multiple embodiments, the first layer WL1 may contain polycrystalline silicon, and the insulating layer WL3 may contain an oxide, thereby the wafer WF may be a POI wafer, but is not limited to these. It should be noted that the thicknesses of the first layer WL1, the insulating layer WL3, and the second layer WL2 may be individually adjusted as needed.

[0059] In Figure 16, a compensation oxide layer (CPS) may be selectively formed on the upper side of the wafer WF, where the upper side of the wafer WF is above the top surface WL1a of the first layer WL1 that faces the second layer WL2, and so the first layer WL1 is located between the compensation oxide layer CPS and the second layer WL2. The oxide material included in the compensation oxide layer CPS and the thickness of the compensation oxide layer CPS may be designed according to actual requirements.

[0060] In Figure 16, the first conductive layer CT1 and the actuating material AM may be formed in sequence on the upper side of the wafer WF (above the first layer WL1), so that the first conductive layer CT1 is located between the actuating material AM and the first layer WL1. For example, the first conductive layer CT1 may be in contact with the actuating material AM.

[0061] The first conductive layer CT1 may contain any suitable conductive material, and the working material AM may contain any suitable material. In some of the multiple embodiments, the first conductive layer CT1 may contain a metal (e.g., platinum (Pt)), and the working material AM may contain a piezoelectric material (e.g., lead zirconate titanate (PZT)), but is not limited to these. Furthermore, the thicknesses of the first conductive layer CT1 and the working material AM may be individually adjusted according to the actual requirements.

[0062] Next, in Figure 16, the working material AM, the first conductive layer CT1, and the compensating oxide layer CPS are provided, and then they may be etched or patterned in sequence.

[0063] As shown in Figure 17, the separating insulating layer (SIL) is formed on the working material AM and may be patterned. The thickness and material of the separating insulating layer (SIL) may be designed according to requirements. For example, the material of the separating insulating layer (SIL) may be an oxide, but is not limited to these.

[0064] As shown in Figure 17, a second conductive layer CT2 may be formed on the working material AM and the isolation insulating layer SIL, and then the second conductive layer CT2 may be etched or patterned. In one embodiment, the second conductive layer CT2 may be formed by sputtering. The thickness and material of the second conductive layer CT2 may be designed according to requirements. For example, the second conductive layer CT2 may contain a metal such as aluminum-copper (AlCu) or titanium nitride (TiN), but is not limited to these. For example, the second conductive layer CT2 may be in contact with the working material AM. The isolation insulating layer SIL may be configured to separate at least a portion of the first conductive layer CT1 from at least a portion of the second conductive layer CT2.

[0065] The working material AM, electrode E1 belonging to the first conductive layer CT1, and electrode E2 belonging to the second conductive layer CT2 may form sublayers within the actuator ATR of the APG device 200 (for example, each of actuator 101A and actuator 103A). In this way, the actuator ATR is formed on the first layer WL1, and the actuator ATR is a piezoelectric actuator comprising two electrodes E1 and E2 and the working material AM between the two electrodes E1 and E2.

[0066] As shown in Figure 18, the first layer WL1 of the wafer WF may be patterned to form trench lines TL. In Figure 18, the trench lines TL are the portions of the first layer WL1 that are removed / etched. That is, the trench lines TL are located between two portions of the first layer WL1.

[0067] It should be noted that the trench line TL will become the slit 212 in subsequent steps (e.g., Figure 20). Thus, the design of the trench line TL is related to the design of the slit 212. That is, the trench line TL may be formed to have a zigzagging pattern and other required shapes that conform to the shape of the slit 212 mentioned above.

[0068] In other words, Figure 18 illustrates in cross-sectional view a semiconductor manufacturing process for forming trench lines TL or zigzagging patterned slits (e.g., 212, 412, 512, etc.). Top views of trench lines TL or zigzagging patterned slits (e.g., 212, 412, 512, etc.) of this application may refer to Figures 5C, 14, and 15. The patterning / formation of trench lines TL will have the characteristics of zigzagging patterned slits as mentioned above.

[0069] Selectively and as necessary, a covering layer CV may be formed on the second conductive layer CT2, on the isolation insulating layer SIL, and on the wafer WF (for example, by using atomic layer deposition (ALD)) as shown in Figure 19 (i.e., in Figure 19, the covering layer CV may be formed on the actuator ATR), and then the covering layer CV may be patterned, and the covering layer CV may be an insulating layer. The thickness of the covering layer CV and the insulating material of the covering layer CV may be designed according to requirements. For example, the covering layer CV may contain, but is not limited to, aluminum oxide. Furthermore, in Figure 19, after patterning the covering layer CV, a portion of the second conductive layer CT2 may not be covered by the covering layer CV, and this portion of the second conductive layer CT2 may serve as a pad PD.

[0070] As shown in Figure 20, the second layer WL2 of the wafer WF may be etched or patterned to remove a portion of the first layer WL1 from the second layer WL2, thereby forming a film structure 10 (i.e., a film structure 10 is formed, which is this portion of the first layer WL1). More specifically, the second layer WL2 of the wafer WF has a first portion and a second portion, the first portion of the second layer WL2 may be removed, the second portion of the second layer WL2 may be left behind, and in the Z direction, a portion of the first layer WL1 corresponding to the removed first portion of the second layer WL2 may function as (a flap of) the film structure 10 or be considered to become (a flap of) the film structure 10, the second portion of the second layer WL2 may be combined with the other portion of the first layer WL1 to form an anchor structure 110, and the film structure 10 may be considered to be anchored to the anchor structure 110. For example, the first portion of the second layer WL2 may be removed by a deep reactive ion etching (DRIE) process, but is not limited to these. It should be noted that the membrane structure 10 may be actuated by the actuator ATR during the operation of the APG device 200.

[0071] Furthermore, since an insulating layer WL3 exists on the wafer WF, after patterning the second layer WL2 of the wafer WF, a portion of the insulating layer WL3 corresponding to the first portion of the second layer WL2 may be removed. In some of the multiple embodiments, since a portion of the coating layer CV exists at the bottom of the trench line TL (as shown in Figure 19), after patterning the insulating layer WL3 of the wafer WF, this portion of the coating layer CV at the bottom of the trench line TL may be removed so that the trench line TL becomes a slit 212. In this way, the trench line TL forms a slit 212 having a zigzag pattern, and the slit 212 penetrates through the film structure 10 (first layer WL1).

[0072] In Figure 20, the second portion of the second layer WL2, the portion of the insulating layer WL3 that overlaps with the second portion of the second layer WL2, and the portion of the first layer WL1 that overlaps with the second portion of the second layer WL2 may be combined to function as an anchor structure 110.

[0073] As described above, the film structure 10 includes a flap pair 102 including flaps 101 and 103 (as shown in Figure 5C), so that flaps 101 and 103 of the film structure 10 are determined when patterning the first layer WL1 of the wafer WF to form a trench line TL (i.e., flaps 101 and 103 are separated from each other by the trench line TL). Then, after the trench line TL becomes a slit 212, flaps 101 and 103 are separated from each other by the slit 212.

[0074] According to the above manufacturing method, an APG device having slits patterned in a zigzag shape is formed.

[0075] In short, the present invention utilizes a slit or zigzag slit with toothed edges to enhance the asymmetry of air pulses and thus improve the performance of the APG device.

[0076] Those skilled in the art will readily understand that numerous modifications and changes to the devices and methods may be made while retaining the teachings of the present invention. Therefore, the above disclosure should be construed as being limited only by the boundaries of the appended claims.

Claims

1. A method for manufacturing an air pulse generation device, the method being The steps include providing a wafer including a first layer and a second layer, The steps include patterning the first layer of the wafer to form slits having a zigzag pattern, The process includes the step of removing the first portion of the second layer, The portion of the first layer above the portion of the second layer to be removed forms a film structure. The slit having the zigzag pattern separates the membrane structure into a first flap and a second flap. The slit having the zigzag pattern is folded back and forth in a zigzag pattern between the first direction and extends toward the second direction. The air pulse generation device generates multiple air pulses by activating the membrane structure. method.

2. The method according to claim 1, comprising the step of forming a first electrode and a working material on the first layer of the wafer.

3. The steps include providing a first conductive layer and a working material to the first layer of the wafer, The steps include etching the first conductive layer and the working material, The method according to claim 1, including the method described in claim 1.

4. The method according to claim 2, comprising the step of forming a second electrode on the working material.

5. The steps include forming a second conductive layer on the working material by sputtering, The steps include etching the second conductive layer and The method according to claim 2, including the method described in claim 2.

6. The method according to claim 1, wherein the slit includes a non-zero projection in the first direction.

7. The step of forming the slit having the zigzag pattern such that the first flap includes a plurality of first protrusions and the second flap includes a plurality of second protrusions, The method according to claim 1, wherein the first projection and the second projection are arranged alternately with respect to each other.

8. The process includes the step of forming the slit having the zigzag pattern such that the first flap includes a plurality of first protrusions and a plurality of first recesses. The method according to claim 1, wherein the first projection and the first recess are arranged alternately with respect to each other.

9. The process includes the step of forming the slit having the zigzag pattern such that the first flap includes a plurality of first protrusions, The method according to claim 1, wherein one of the first projections has a base-shaped portion.

10. The process includes the step of forming the slit having the zigzag pattern such that the first flap includes a plurality of first protrusions, One of the first projections corresponds to the width, The method according to claim 1, wherein the width is greater than the height of the wall between the first flap and the second flap.

11. The process includes the step of forming the slit having the zigzag pattern such that the first flap includes a plurality of first protrusions, One of the first projections corresponds to the width, The method according to claim 1, wherein the width is greater than the difference in displacement between the free end of the first flap and the free end of the second flap when the virtual valve is opened.

12. The process includes the step of forming the slit having the zigzag pattern such that the first flap includes a plurality of first protrusions, One of the first projections corresponds to the depth, The method according to claim 1, wherein the depth is greater than 15% of the distance between anchors.

13. The method according to claim 1, comprising the step of forming the slit having a tooth edge pattern.

14. The method according to claim 1, comprising the step of forming the slit having a rectangular tooth edge pattern or a trapezoidal tooth edge pattern.

15. The method according to claim 1, wherein the first flap and the second flap are actuated to perform differential motion to form an opening or virtual valve, the opening or virtual valve being formed by the slit having the zigzag pattern.

16. When the difference in displacement between the first flap and the second flap is less than the thickness of the membrane structure, the virtual valve is in a closed state. The method according to claim 15, wherein the closed state of the virtual valve occurs during the transition of the differential motion of the first flap and the second flap.

17. The method according to claim 1, comprising the step of forming the slit having the zigzag pattern such that the area coverage ratio is 0.25 or more.

18. The method according to claim 1, comprising the step of forming the slit having the zigzag pattern such that the displacement coverage ratio is 0.5 or more.

19. The air pulse generating device according to claim 1, applicable to applications of generating sound.

20. The air pulse generating device according to claim 1, applicable to air transport applications.

21. The steps include forming or providing a covering structure, The method according to claim 1, wherein the chamber is formed between the membrane structure and the coating structure.

22. The step includes forming an orifice in the aforementioned covering structure, The method according to claim 21, wherein the plurality of air pulses propagate outward through the orifice.

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