Manufacturing method of air-pulse generating device

Abstract

A method for manufacturing an air pulse generating device is provided. The manufacturing method comprises the steps of: providing a wafer comprising a first layer and a second layer; patterning the first layer of the wafer to form a zigzag pattern slit; and removing a first portion of the second layer. A portion of the first layer above the removed first portion of the second layer forms a film structure. The zigzag pattern slit separates the film structure into a first flap and a second flap. The zigzag pattern slit extends zigzag forward and backward between a first direction and a second direction toward the second direction. The air pulse generating device operates the film structure to generate a plurality of air pulses.

Description

Technology 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] In the conventional speaker industry, the two major design challenges are the speaker driver and the back enclosure. It is difficult for a single conventional speaker (e.g., a dynamic driver) to cover the entire audio frequency band, e.g., 20 Hz to 20 kHz. To produce high-fidelity sound with a sufficiently high sound pressure level (SPL), both the radiating / moving surface of the conventional speaker and the volume / size of the back enclosure must be sufficiently large.

[0003] U.S. Patents No. 9,736,595 and 10,367,430 discussed ultrasonic pulses for sound generation applications. Additionally, to address the aforementioned bandwidth and size issues, the applicant disclosed air-pulse generating (APG) devices or air pressure pulse speakers (APPS) in U.S. Patents No. 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 pulses generated by the APG device.

[0005] Therefore, the primary objective of the present application is to provide an APG device capable of generating asymmetric air pressure pulses to improve upon the disadvantages of the prior art.

[0006] An embodiment of the present disclosure provides a method for manufacturing an air pulse generating device. The manufacturing method comprises the steps of: providing a wafer comprising a first layer and a second layer; patterning the first layer of the wafer to form a zigzag pattern slit; and removing a first portion of the second layer. A portion of the first layer above the removed first portion of the second layer forms a film structure. The zigzag pattern slit separates the film structure into a first flap and a second flap. The zigzag pattern slit extends zigzag forward and backward between a first direction and a second direction toward the second direction. The air pulse generating device operates the film structure to generate a plurality of air pulses.

[0007] These and other objectives of the present invention will undoubtedly become apparent to those skilled in the art after reading the following detailed description of preferred embodiments illustrated in the various drawings. Brief explanation of the drawing

[0008] Figure 1 is a cross-sectional view of an air pulse generation (APG) device. Figure 2 shows the wiring method of an APG device. Figure 3 shows the modulation signal and the demodulation signal. Figure 4a shows a cross-sectional view of an APG device. Figure 4b shows a plan view of the APG device of Figure 4a. Figure 4c shows the direction of airflow when the virtual valve (VV) of the APG device of Figure 4b is open. Figures 5 (A) and (B) show cross-sectional views of an APG device according to one embodiment of the present application. Figure 5 (C) shows a plan view of the APG device of Figures 5 (A) and (B). Figure 5 (D) shows the direction of airflow when the virtual valve (VV) of the APG device in Figure 5 (C) is open. Figure 6 shows that the first flap and the second flap of the APG device of Figure 5 (C) are separated. FIG. 7 shows the common mode movement of the first flap and the second flap of the APG device of FIG. 5 (C). FIG. 8 shows the differential mode movement of the first flap and the second flap of the APG device of FIG. 5 (C). Figures 9 (A) and (B) show the combined common mode displacement of the common mode motion and the acoustic conductance of the differential mode motion for the APG device of Figures 4a to 4c (hereinafter also referred to as Figure 4) and Figure 5. (A) of FIG. 10 shows the combined common mode displacement for the porosity of the APG device of FIG. 5 (C) according to one embodiment of the present application. Fig. 10 (B) shows the virtual / effective common mode displacement for the porosity of the APG device of Fig. 5 (C) according to one embodiment of the present application. FIG. 11 shows an APG device according to one embodiment of the present application. FIG. 12 shows the common mode motion and differential mode motion of an APG device within one cycle according to one embodiment of the present application. Figure 13 (A) shows the combined common mode displacement and common mode acceleration for the porosity of an APG device according to one embodiment of the present application. Figures 13 (B) and (C) show the combined common mode displacement for the porosity of an APG device according to one embodiment of the present application. FIG. 14 shows an APG device according to one embodiment of the present application. FIG. 15 shows an APG device according to one embodiment of the present application. FIGS. 16 to 20 show structures at various different stages of a manufacturing method / process for manufacturing an APG device according to one embodiment of the present application. Specific details for implementing the invention

[0009] This application incorporates by reference the contents of U.S. Patent No. 11,943,585 B2 and U.S. Application No. 18 / 624,105.

[0010] The air pulse generating device of the present application generally comprises a pair of opposite flaps manufactured 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 opposite flaps is actuated to move up and down, thereby generating both common mode motion and differential mode motion to perform the functions of modulation and demodulation, respectively.

[0011] Specifically, FIG. 1 is a cross-sectional view of an air pulse generation (APG) device (100). The APG device comprises a film structure (e.g., a membrane or a diaphragm) (10). The film structure (10) comprises a flap (101) and a flap (103) facing each other. The operating principle of the APG device (100) is similar to that disclosed in U.S. Patent No. 11,943,585 B2. The flap (101) and the flap (103) (formed as a pair of flaps (102)) are operated to perform a common mode motion to form an ultrasonic air pressure change amplitude-modulated at an ultrasonic frequency (e.g., 192 KHz), which can be considered as a modulation motion. Meanwhile, the flap (101) and the flap (103) are also operated to perform differential movement to form an opening (112) or a virtual valve (abbreviated as VV) (112) at an ultrasonic opening rate (e.g., 192 KHz) to perform demodulation.

[0012] In the embodiment of the APG device (100) illustrated, differential motion (demodulation) and common mode motion (modulation) are performed simultaneously by a pair of flaps (102). Simultaneous modulation and demodulation can be performed in situ and by a specific wiring method. For example, as illustrated in FIG. 2, the APG device (100) may include an actuator (101A) placed on a flap (101) and an actuator (103A) placed on a flap (103). The actuator (101A) and the actuator (103A) include a top electrode and a bottom electrode. In one embodiment, the lower electrodes of actuator (101A) and actuator (103A) receive a common modulation signal SM, and the upper electrodes of actuator (101A) and actuator (103A) receive differential demodulation signals +SV and -SV, wherein the demodulation signals +SV and -SV have opposite polarities. Note that the wiring scheme illustrated in FIG. 2 is for illustrative purposes only and is not limited thereto. As long as one electrode of actuator (101A / 103A) receives the modulation signal SM and the other electrode receives the demodulation signal SV (representing +SV or -SV), the requirements of the present application are satisfied and are within the scope of the present application.

[0013] Refer to FIG. 3 (or one similar to that shown in FIG. 3) for the waveforms of the modulation signal SM and the demodulation signal ±SV. Note that the demodulation frequency of the demodulation signal SV is half the modulation frequency of the modulation signal SM. For example, when the modulation signal SM has a modulation frequency of 192KHz, the demodulation signal SV will have a demodulation frequency of 96KHz. Thus, flaps (101) and (103) form an opening (112) with an opening rate of 192KHz, and the APG device (100) has an ultrasonic pulse rate of 192KHz. It generates multiple air pulses.

[0014] In the present application, "flap (101) and flap (103) perform common mode movement" means that flap (101) and flap (103) are actuated to move toward a common direction or are actuated by a common driving signal, and "flap (101) and flap (103) perform differential mode movement" means that flap (101) and flap (103) are actuated to move / bend in different / opposite directions relative to a common position or are actuated by a differential signal pair.

[0015] A 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) because they share the same location and express similar concepts in other aspects. By driving the flap (101) and the flap (103) through the demodulation signal ±SV, the distance between the free end of the flap (101) and the free end of the flap (103) is expanded to form the opening (112) or VV (112). The upper part of FIG. 1 shows a snapshot with the VV (112) closed / sealed, and the lower part of FIG. 1 shows a snapshot with the VV (112) open.

[0016] The pattern of the slit (112) on / above the film structure (10) is not limited. Intuitively, the slit (112) can have a straight slit pattern. FIGS. 4a–4c show schematic diagrams of an APG device with a straight slit pattern. As shown in FIG. 4b, the slit (112) with a straight slit pattern can be considered to have a projection of zero for the X direction / dimension. An APG device with a straight slit pattern is successful in generating asymmetric airflow pulses. However, the asymmetry of the air pressure pulse generated by an APG device with a straight slit pattern may not be so obvious or even measurable. This is because, as shown in FIG. 4c, the airflow around the VV (112) is very congested and the airflow bypasses the VV (112) before reaching it, where FIG. 4c schematically shows the airflow vector around the VV (112). In some drawings of the present application, various different types of shading are used to indicate the relationship between the flap (101) and the flap (103), but this does not mean that the flap (101) and the flap (103) are made of different materials.

[0017] Airflow congestion will increase the pressure difference ΔP surrounding VV (112) (when VV (112) is (blocked) "open"), where ΔP = P A - P B and P A / P B represents the air pressure just above / below the plane defined by the flap (101) / flap (103). Ideally, the pressure difference ΔP should be neutralized as quickly as possible when the VV is opened. However, the neutralization of the pressure difference ΔP corresponding to the straight pattern slit is not sufficiently fast. This is due to the airflow lateral component and airflow diversion.

[0018] As illustrated in FIG. 4, the airflow vector contains a strong lateral component (a component other than the Z direction in the straight slit pattern illustrated in FIG. 4b; the lateral component represents a component parallel to the X direction), which implies airflow diversion. Airflow diversion not only lengthens the airflow passage but also slows down the response of the pressure balance across the two sides of the flaps (101, 103). After reaching the vicinity of VV (112), the air waits for its turn to be pushed out through the narrow opening of VV (112). All these steps / factors lead to their respective low-pass filter (LPF) effects. Combining these factors creates a powerful higher-order LPF, which Removes the harmonics. Since a strong asymmetric waveform implies strong spectral components in the harmonics, these Removing the harmonics alleviates asymmetry.

[0019] The asymmetry of air pressure pulses is critical to the performance of APG devices for both sound-generating applications (which can be considered as AC (Alternating Current) airflow) and air motion applications (which can be considered as DC (Direct Current) airflow). It is desirable to propose a novel APG design featuring air pressure pulse asymmetry.

[0020] Below are some guidelines. To avoid airflow congestion, the VV should be designed to extend a significant amount in the X direction / dimensional area (or at least include a non-zero projection in the X direction / dimensional area). In other words, the VV should extend a significant proportion of the total area of ​​the flap (101, 103) (or occupy a significant area). For example, the VV (112) may occupy 20 to 40 percent (or at least 15 percent) of the total area of ​​the flap (101, 103), but is not limited thereto.

[0021] In addition, to minimize lateral components when VV is "open," the acoustic impedance of VV must be distributed nearly uniformly in the X direction so that air flows straight through VV (mostly in the Z direction). The coupled common mode displacement U Z.COM ( x It is proposed that the amplitude of ) is mostly uniformly distributed in the X direction. U Z.COM ( x ) is a combination / aggregation of the common mode displacements of flap (101) and flap (103). For example, U Z.COM ( x ) can be expressed as follows:

[0022] , here represents the individual common mode displacement (corresponding to the X-dimensional variable x) of the flap (101) / flap (103), and w 101 ( x ) / w 103 ( x ) represents the corresponding weighting factor. In one embodiment, w 101 ( x ) / w 103 ( x ) = 0.5, but is not limited to this.

[0023] One solution to avoid airflow congestion and minimize lateral components is to pattern / form slits in a zigzag pattern in the film structure. In this application, a zigzag pattern slit may mean: 1) the slit is not straight; 2) the slit changes direction back and forth; or 3) the slit is zigzag patterned back and forth between the X and Y directions and extends toward the Y direction, so that, in terms of planar view, the slit has a non-zero projection with respect to the X direction / dimension. The projection of the zigzag patterned slit with respect to the X direction / dimension may have a length / depth that is a significant percentage (e.g., 15% or more) of the anchor-to-anchor distance between flap (101) and flap (103) or the APG device.

[0024] Please refer to FIGS. 5 (A) to (D), which show an APG device (200) according to one embodiment of the present invention. FIGS. 5 (C) shows a zigzag pattern (partial) of a slit (212) from a planar view perspective. FIGS. 5 (A) and (B) show cross-sectional views along lines AA' and B-B' when the flap (101) and flap (103) are kept flat (or when the VV (212) is closed). FIGS. 5 (D) schematically shows the air flow vector when the zigzag pattern VV ((212)) is open along line DD' of FIGS. 5 (C).

[0025] The width (dimension / size in the Y direction) of the APG device (200) is not limited to that shown in (C) of FIG. 5. The APG device (200) may include a wide cantilever, which means that the width of the APG device (200) may be greater than several times the length (dimension / size in the X direction) of the APG device (200). Or, in one embodiment, the flap (101) and the flap (103) may extend in the Y direction and have a relatively extreme aspect ratio (e.g., greater than 2 or less than 1 / 2), but are not limited thereto.

[0026] The slit (212) may have a sawtooth edge pattern. Specifically, FIG. 6 shows a flap (101) separated from a flap (103) having a sawtooth-patterned edge. As illustrated in FIG. 6, the flap (101) / flap (103) includes a protruding part (protrusion) (220 / 240) and a depression (depression) (222 / 242). The protrusion (220) and the protrusion (240) are staggered. When the flap (101) and the flap (103) are separated only by the slit (212) (see FIG. 5 (C) and FIG. 6), the recess (242) of the flap (103) accommodates the protrusion (220) of the flap (101), and vice versa, so the protrusion (220) of the flap (101) and the protrusion (240) of the flap (103) are misaligned. Also, in FIG. 5 (C), the slit (212) has a rectangular sawtooth edge pattern as an example.

[0027] In (C) of FIG. 5, the slit (212) is not a straight line and changes direction back and forth. The slit (212) x 103L class x 101R It can be viewed as extending in the Y direction while moving in a zigzag pattern back and forth between / across the X direction. Tooth depth D T , x 103L class x 101R The distance between (shown in (C) of Fig. 5) is x 101L class x 103R Distance d between anchors AA It may be a certain percentage (e.g., 15% or more or 20-40%), where the flap (101) and flap (103) of the APG device (200) must be fixed to an anchor structure like the APG device (100), but for simplicity, the anchor structure is omitted in FIG. 5.

[0028] Additionally, the concave portion (222) of the flap (101) (or the protruding portion (240) of the flap (103) ignoring the slit width) has a width W T It can have, which also indicates the length of the segment (231). In (C) of FIG. 5, W T can be considered as the width of the protrusion of the flap (103). To effectively reduce acoustic resistance, in one embodiment, the width W T is W T ≥ 1.5 THH slit or W T ≥ 1.5 THU Z_open It can be selected to be (but not limited to), where H slit represents the height of the opposing wall between the flap (101) and the flap (103), which is generally defined by the thickness of the film structure, and U Z_open W represents the difference in displacement between the free end of the flap (101) and the free end of the flap (103) in the Z direction when VV (212) is open. T ≥ H slit or W T ≥ U Z_open Insofar as..., the requirements of the present application will be satisfied and will be within the scope of the present application.

[0029] The length is W TDue to the line segment (231), the protruding part of the flap (103) has a flat top (also indicated as 231) and the recessed part of the flap (101) has a flat bottom (also indicated as 231). The flat top of the protruding part of the flap (101) / flap (103) will be beneficial for reducing acoustic resistance (compared to the case of a protruding part with a sharp tip), and the flat bottom of the flap (101) / flap (103) will be beneficial for increasing the slit length to enhance the effect of reducing acoustic resistance between the teeth (compared to the case of a recessed part with a sharp tip). Generally, compared to a slit with a sawtooth shape / sine wave pattern, the slit can be patterned so that the protruding part of the flap (101) / flap (103) has a plateau (e.g., 231) for the reason of reducing acoustic resistance.

[0030] Note that in (C) of FIG. 5, the slit (212) has a non-zero projection in the X direction / dimension, i.e., the line segment (232). In comparison, the slit (112) of FIG. 4b is considered to have a zero projection in the X direction / dimension, geometrically or from a planar perspective. Additionally, the slit (212) must be longer than the slit (112).

[0031] When the flap (101) and flap (103) are actuated to perform differential motion, the acoustic impedance and lateral airflow components are significantly reduced due to the fact that the slit (212) is elongated and the slit (212) contains a non-zero projection in the X direction / dimension. The airflow x 103L class x 101R It flows through the area between. Also, as can be seen in (D) of FIG. 5, the direction of air flow can be mostly perpendicular to the XY plane, which is the plane defined by the flap (101) and the flap (103). Consequently, the pressure difference ΔP will be neutralized much faster than when VV (112) is open (when VV (212) is open).

[0032] FIGS. 7 and FIGS. 8 represent the time sequences of common mode displacement and differential mode displacement, respectively, where t CYC represents the cycle time. In one embodiment These two time sequences are merely examples and may not actually exist separately (e.g., in time-division operation) and may be combined into one movement for the flap (101) and another movement for the flap (103) through the wiring connection method shown in FIG. 2. For further details, refer to U.S. Patent No. 11,943,585 B2 incorporated herein by reference and the references contained therein.

[0033] As shown in Fig. 8, During the time interval, VV (212) is considered to be in an "open" state, and the region outlined by segments 231–232 is considered to be "highly porous," "acoustically translucent," and "non-pressurized," which is this This means that within the period, the common mode motion of the flap (101) and the flap (103) produces a result of minimum ΔP and the common mode motion of the flap (101) and the flap (103) is substantially "extinguished."

[0034] on the other way, During the time interval, VV (212) 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 "pressurized," which is this This means that within the period, the flap (101) and the flap (103) can be treated as a continuous membrane and can behave as one (a complete membrane) in terms of membrane movement and membrane acceleration.

[0035] As can be seen, when the difference in displacement between the flap (101) and the flap (103) is less than or equal to the thickness of the film structure, i.e., ΔUZ ≤ H slit When, VV (e.g., 112 or 212) is in a closed state, where is, U Z,101 / 103 represents the vertical (Z direction / dimension) displacement of the flap (101) / flap (103). Note that in the APG device of the present application, the closed state of the VV occurs during the transition of the differential motion of the flap (101) and the flap (103). In other words, during the period when the flap (101) moves in a first direction (e.g., downward) and the period when the flap (103) moves in a second direction opposite to the first direction (e.g., upward), the VV is closed, and the displacement difference (ΔU) between the free end of the flap (101) and the free end of the flap (103) Z ) is film structure H slit Make it smaller than the thickness of. Simply put, when the virtual valve closes, both flaps move.

[0036] Figures 9 (A) and (B) respectively repeat the common mode motion and differential mode motion of the APG device (200). Additionally, Figure 9 (A) shows the combined common mode displacement U for the variable x in the X dimension when both flaps are operated in common mode. Z.COM ( x ) represents, and (B) of FIG. 9 is the acoustic conductivity 1 / Z for x when both flaps are operated in differential mode. VV Represents, where Z VV represents the acoustic impedance of VV.

[0037] From (A) of FIG. 9, the combined common mode displacement U corresponding to VV (212) Z.COM ( x ) when compared to the one corresponding to VV(112), x 103L class x 101R It can be seen that it is evenly distributed across the X dimension between them. From (B) of Fig. 9, the acoustic impedance Z VV go x103L class x 101R Low within the range between, and mostly 103L class x 101R It can be seen that it is evenly distributed across the X dimension between them. It can be concluded that an APG device with a zigzag slit (e.g., slit (212)) can successfully avoid airflow congestion and minimize lateral components, thereby producing an asymmetric air pressure pulse.

[0038] Also, the "caused to expire" period or VV opening period (e.g., in FIG. 8 ) is the substantial displacement U as shown in (A) of FIG. 10. Z.COM ( t It must be properly synchronized and aligned with ). By considering the period that "caused it to vanish," the physical displacement U Z.COM ( t As shown in (B) of FIG. 10, virtual / actual motion UV Z.COM It can be converted into or considered as a sequence. For sound generation applications or APPS (Air Pressure Pulse Speaker) applications, these asymmetric virtual motion UVs Z.COM It can be utilized to generate asymmetric pressure pulses, for example, through chamber compression.

[0039] For example, please refer to FIG. 11, which shows a schematic diagram of an APG device (300). The APG device (300), which includes a VV (312) (which may be a zigzag slit, e.g., VV (212)), includes a cap (320) used to form a compression chamber (315). Following the timing diagram of FIG. 10 (A), as shown in FIG. 10 (B), an asymmetric "virtual / actual motion" UV Z.COM ( tIn response to each segment of the chamber, pressure pulses will be generated through chamber compression, which will cause a pressure change at the outlet (313). Due to the pressure change, acoustic waves will propagate outward at the speed of sound into the surrounding environment, creating a chain of acoustic pressure pulses.

[0040] Note that the pressure pulse and the magnitude of the pressure pulse generated within the chamber (315) when VV (312) is in the "closed" state are determined by the common mode displacement of the flap (101, 103) while VV (312) is in the "closed" state. Conversely, during the period when VV (312) / VV (212) is in the "open" state, the airflow flowing through the plates of the flap (101, 103) generates a somewhat small ΔP due to the wide and evenly distributed airflow (over VV (312 / 512)), minimal airflow congestion, low acoustic impedance over VV (312) / VV (212), and a straight and short airflow path, so the effect on the net air pressure pulse generated by the device (300) will be negligible.

[0041] Referring to Fig. 12, which illustrates a different view of common and differential mode interactions, it is applicable to a (indirect) pressure pulse generation method using a compression chamber. The differential mode motion is represented by the "porous" value shown in (A) of Fig. 10. Time During (as shown in FIG. 8), VV (212) enters a "highly porous" state, and ΔP generated by common mode motion is mostly "leaked" through the porous surface, and consequently the period During this period, ΔP of 0 or close to 0 occurs. Therefore, the ΔP due to chamber compression is, as shown in (B) of Fig. 10, during the period It will be governed by the "virtual / actual displacement" that occurred during that time.

[0042] Several design metrics related to the efficiency of bypassing airflow congestion can be defined. For slit patterning, the area coverage ratio (ACR) and displacement coverage ratio (DCR) can be defined as follows:

[0043] (Equation 1)

[0044] (Equation 2).

[0045] In (Equation 1), A(VV) represents the area occupied by the slit (e.g., zigzag slit (212)), and A(101+103) represents the total area of ​​the flap (101) and flap (103). Assuming the perimeter of the film structure is rectangular, the ACR can also be expressed as follows:

[0046] (Equation 3).

[0047] In the present application, particularly in (Equation 2) and (Equation 3), x 101L / x 103L represents the leftmost position on the X-axis of the flap (101) / flap (103), and x 101R / x 103R represents the rightmost position on the X-axis of the flap (101) / flap (103). From another perspective, assuming the perimeter of the film structure is rectangular, x 101L / x 103R represents a position on the X-axis where the flap (101) / flap (103) is fixed, and x 103L / x 101R It is the leftmost / rightmost position on the X-axis of the protrusion of the flap (101) / flap (103).

[0048] To effectively bypass airflow congestion, ACR ≥ 0.25 and DCR ≥ 0.5 are suggested, but are not limited thereto.

[0049] The pressure pulse generation method mentioned above is called an indirect method, and U Z.COM ( t ) or UV Z.COM ( t By utilizing the "displacement" of ), a small chamber (e.g., 315) is compressed to generate a pressure pulse, and this pressure pulse is radiated through a narrow orifice (e.g., 313).

[0050] In addition, air pressure pulses can be generated by a direct method. The direct method conceptually utilizes VV (e.g., 112 or 212) d 2 U Z.COM ( t ) / dt 2 Each pulse cycle t, expressed as CYC "Make part of the acceleration of the flap (101, 103) disappear," d 2 UV Z.COM ( t ) / dt 2 It generates a very asymmetric "virtual acceleration" of the flap (101, 103) represented by.

[0051] In the direct pulse generation method, asymmetric "virtual acceleration" d 2 UV Z.COM ( t ) / d t 2 A pressure pulse will be generated in response to each segment of. For example, as shown in (A) of FIG. 13, the pressure pulse is U Z.COM It will be generated in response to the negative half-cycle common mode displacement of (t), which is positive d 2 UV Z.COM ( t ) / d t2 A positive half-cycle acoustic output will be generated through this. In this case, the air pressure pulse will be generated directly, compared to the indirect method in which an air pressure pulse is generated through chamber compression, because pressure is related to acceleration and acceleration is the double derivative of displacement.

[0052] The timing alignment shown in (A) of FIG. 13 is U Z.COM There is a center-to-center alignment between (t) and the open-closed state of VV (e.g., 112 or 212), but is not limited thereto. For example, (B) in FIG. 13 has an open-closed state timing of U Z.COM ( t While explaining a scenario where the timing is pulled "forward" compared to ), (C) of Fig. 13 shows that the open-closed state timing is U Z.COM ( t Explains a scenario where it is pushed "back" compared to the timing of ). U Z.COM The optimal timing alignment between the open-closed state of (t) and VV (e.g., 112 or 212) depends on the duty factor of VV or how long VV remains in the "closed" state. All variations of these operating conditions are within the scope of the present invention.

[0053] The zigzag slit is not limited to a rectangular sawtooth edge pattern. The zigzag slit may be a trapezoidal sawtooth edge pattern. For example, in FIGS. 14 and FIGS. 15, slit (412) and slit (512) are trapezoidal sawtooth edge patterns. In FIGS. 14, the protrusion (14) of the flap (101) is wider at the bottom (e.g., 401) than at the top (e.g., 402). Conversely, in FIGS. 15, the protrusion of the flap (101) is wider at the top (e.g., 502) than at the bottom (e.g., 501). Both cases and variations thereof (e.g., fillets or chamfers may be formed at the corners of the protrusions of the rectangular / trapezoidal pattern slits) are all within the scope of the present invention.

[0054] The APG device of the present invention can be applied to sound generation applications such as APPS (Air Pressure Pulse Speaker), wherein a plurality of air pulses generated therein are amplitude-modulated, and the envelope of the plurality of air pulses (or the input signal S in which the modulation signal SM is generated) IN Note that the input signal S (see Fig. 3) is an AC (Alternating Current) component or contains it, which can, for example, result in AC airflow. IN It may be an audio signal or may include it. 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, hearing aids, etc. The APG / APPS of the present invention may also function as a loudspeaker or an open field speaker, which may be placed in, but is not limited to, OWS (Open Wearable Stereo), telephones (receivers or speakers), tablets, laptops, desktop (gaming / recording) monitors, televisions, or AR (Augmented Reality) / VR (Virtual Reality) devices.

[0055] In addition, the APG device of the present invention can be applied to an air motion application program having a function similar to a fan, a blower, etc. A plurality of generated air pulses (or an input signal S in which a modulation signal SM is generated) IN The envelope of ) has or contains a DC (Direct Current) component, which can, for example, result in DC airflow. Input signal S IN It may be a DC signal or may include it. In air motion applications, the APG device of the present invention may be used for heat dissipation, ventilation, cooling, drying, or air quality sensing, but is not limited thereto. An APG device in the field of air motion applications is described in detail in U.S. Application No. 18 / 624,105 and is not described herein for brevity.

[0056] The APG device of the present invention may be manufactured by a process such as that shown in FIGS. 16 to 20. Referring to FIGS. 16 to 20, FIGS. 16 to 20 illustrates structures at various different stages of a manufacturing method / process for manufacturing an APG device according to one embodiment of the present application. Specifically, FIGS. 16 to 20 particularly describe in detail the manufacturing process of a flap (e.g., flap (101)) having an actuator (e.g., actuator (101A)) within the APG device. A person skilled in the art may manufacture the flap (101) and flap (103) having an actuator (101A) and an actuator (103A) of the APG device of the present application using the concept shown in FIGS. 16 to 20.

[0057] It should be noted that the method for manufacturing an APG device of the present application is not limited to the following examples and drawings. In some embodiments, other suitable steps may be added before or after one of the existing steps of this method, and / or some steps may be performed simultaneously or individually. In some embodiments, the process sequence of this manufacturing method may be adjusted according to practical requirements.

[0058] In the following manufacturing method for an APG device, the process of forming a layer and / or structure may include, but is not limited to, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), a coating process, other suitable processes, or a combination thereof. In the following manufacturing method for an APG device, the patterning process may include photolithography, an etching process, other suitable processes, or a combination thereof, wherein the etching process may be a wet etching process, a dry etching process, other suitable etching processes, or a combination thereof, but is not limited thereto.

[0059] In the following, this manufacturing method can manufacture an APG device with a zigzag slit pattern, for example, an APG device (200) shown in (A) to (D) of FIG. 5, but is not limited thereto.

[0060] In this embodiment, the APG device with a zigzag slit pattern may be manufactured to become a MEMS chip by at least one semiconductor process, but is not limited thereto. As illustrated in FIG. 16, a wafer (WF) is provided, wherein the wafer (WF) may include a first layer (WL1) and a second layer (WL2), and optionally may include an insulating layer (WL3) between the first layer (WL1) and the second layer (WL2).

[0061] Since the first layer (WL1), the insulating layer (WL3), and the second layer (WL2) may individually comprise any suitable material, the wafer (WF) may be any suitable type. For example, the first layer (WL1) and the second layer (WL2) may individually comprise silicon (e.g., single-crystal 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 comprise an oxide such as silicon oxide (e.g., silicon dioxide), but is not limited thereto. In some embodiments, since the first layer (WL1) may comprise single-crystal silicon and the insulating layer (WL3) may comprise an oxide, the wafer (WF) may be an SOI wafer, but is not limited thereto. In some embodiments, the first layer (WL1) may comprise polycrystalline silicon and the insulating layer (WL3) may comprise an oxide, so the wafer (WF) may be a POI wafer, but is not limited thereto. The thicknesses of the first layer (WL1), the insulating layer (WL3), and the second layer (WL2) may be individually adjusted based on requirements.

[0062] In FIG. 16, a compensation oxide layer (CPS) can be optionally formed on the upper side of the wafer (WF), where the upper side is above the top surface (WL1a) of the first layer (WL1) opposite to the second layer (WL2), so that the first layer (WL1) is between the compensation oxide layer (CPS) and the second layer (WL2). The oxide material contained in the compensation oxide layer (CPS) and the thickness of the compensation oxide layer (CPS) can be designed based on actual requirements.

[0063] In FIG. 16, since the first conductive layer (CT1) and the working material (AM) can be formed sequentially on the upper side of the wafer (WF) (above the first layer (WL1)), the first conductive layer (CT1) may be between the working material (AM) and the first layer (WL1). For example, the first conductive layer (CT1) may be in contact with the working material (AM).

[0064] The first conductive layer (CT1) may comprise any suitable conductive material, and the operating material (AM) may comprise any suitable material. In some embodiments, the first conductive layer (CT1) may comprise a metal (e.g., platinum (Pt)), and the operating material (AM) may comprise a piezoelectric material (e.g., lead zirconate titanate (PZT)), but is not limited thereto. Additionally, the thicknesses of the first conductive layer (CT1) and the operating material (AM) may be individually adjusted based on actual requirements.

[0065] Then, in FIG. 16, the working material (AM), the first conductive layer (CT1), and the compensation oxide layer (CPS) are provided and can then be sequentially etched or patterned.

[0066] As illustrated in FIG. 17, a separating insulation layer (SIL) can be formed and patterned on the working material (AM). The thickness of the separating insulation layer (SIL) and the material of the separating insulation layer (SIL) can be designed based on requirements. For example, the material of the separating insulation layer (SIL) may be an oxide, but is not limited thereto.

[0067] As illustrated in FIG. 17, after the second conductive layer (CT2) is formed on the working material (AM) and the separating insulating layer (SIL), 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 of the second conductive layer (CT2) and the material of the second conductive layer (CT2) may be designed based on requirements. For example, the second conductive layer (CT2) may include, but is not limited to, metals such as aluminum-copper (AlCu) or titanium nitride (TiN). For example, the second conductive layer (CT2) may be in contact with the working material (AM). Note that the separating 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).

[0068] The working material (AM), the electrode (E1) belonging to the first conductive layer (CT1), and the electrode (E2) belonging to the second conductive layer (CT2) may be sublayers of the actuator (ATR) of the APG device (200) (e.g., actuators (101A, 103A) respectively). Thus, the piezoelectric actuator (ATR) comprising the two electrodes (E1) and the electrode (E2) and the working material (AM) between the two electrodes (E1) and the electrode (E2) is formed in the first layer (WL1).

[0069] As illustrated in FIG. 18, a first layer (WL1) of a wafer (WF) can be patterned to form a trench line (TL). In FIG. 18, the trench line (TL) is a portion of the first layer (WL1) that is removed / etched. That is, the trench line (TL) is located between two portions of the first layer (WL1).

[0070] Note that the trench line (TL) will become a slit (212) in a subsequent process (e.g., FIG. 20). Therefore, the design of the trench line (TL) is related to the design of the slit (212). That is, the trench line (TL) can be formed to have a zigzag pattern and other necessary features according to the characteristics of the aforementioned slit (212).

[0071] In other words, FIG. 18 illustrates a cross-sectional view of a semiconductor manufacturing process for forming a trench line (TL) or a zigzag pattern slit (e.g., 212, 412, 512). A plan view of the trench line (TL) or the zigzag pattern slit (e.g., 212, 412, 512) of the present application may be referenced in FIG. 5 (C), FIG. 14, and FIG. 15. Patterning / forming the trench line (TL) will have the characteristics of the aforementioned zigzag pattern slit.

[0072] Optionally, as illustrated in FIG. 19, a cover layer (CV) may be formed on a second conductive layer (CT2) (e.g., using atomic layer deposition (ALD)), a separating insulating layer (SIL), and a wafer (WF) (i.e., in FIG. 19, the cover layer (CV) may be formed on an actuator (ATR)), and then the cover layer (CV) may be patterned, wherein the cover layer (CV) may be an insulating layer. The thickness of the cover layer (CV) and the insulating material of the cover layer (CV) may be designed based on requirements. For example, the cover layer (CV) may include, but is not limited to, aluminum oxide. Also, in FIG. 19, after patterning the cover layer (CV), a portion of the second conductive layer (CT2) may not be covered by the cover layer (CV), and this portion of the second conductive layer (CT2) may serve as a pad (PD).

[0073] As illustrated in FIG. 20, the second layer (WL2) of the wafer (WF) can be etched or patterned so that a portion of the first layer (WL1) is released from the second layer (WL2) to form a film structure (10) (i.e., a film structure (10) is formed, and the film structure (10) is this portion of the first layer (WL1)). To explain in detail, the second layer (WL2) of the wafer (WF) may have a first portion and a second portion, the first portion of the second layer (WL2) may be removed and the second portion of the second layer (WL2) may remain, wherein the portion of the first layer (WL1) corresponding to the removed first portion of the second layer (WL2) in direction Z may act as a flap of the film structure (10) or may be considered as the film structure (10), the second portion of the second layer (WL2) may be combined with another portion of the first layer (WL1) and considered as an anchor structure (110), and the film structure (10) may be considered to be fixed 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 thereto. Note that the film structure (10) can be actuated by an actuator (ATR) during the operation of the APG device (200).

[0074] Furthermore, since an insulating layer (WL3) of the wafer (WF) exists, after the second layer (WL2) of the wafer (WF) is patterned, a portion of the insulating layer (WL3) corresponding to the first portion of the second layer (WL2) can also be removed. In some embodiments, since a portion of the covering layer (CV) exists at the bottom of the trench line (TL) (as shown in FIG. 19), after the insulating layer (WL3) of the wafer (WF) is patterned, this portion of the covering layer (CV) existing at the bottom of the trench line (TL) can be removed so that the trench line (TL) becomes a slit (212). Thus, due to the trench line (TL), a slit (212) having a zigzag pattern and other necessary features is formed, and the slit (212) penetrates the film structure (10) (first layer (WL1)).

[0075] In FIG. 20, a second part of the second layer (WL2), a part of the insulating layer (WL3) that overlaps with the second part of the second layer (WL2), and a part of the first layer (WL1) that overlaps with the second part of the second layer (WL2) can be combined to serve as an anchor structure (110).

[0076] According to the above, since the film structure (10) includes a pair of flaps (102) including a flap (101) and a flap (103) (as shown in (C) of FIG. 5), the flaps (101) and flaps (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., the flaps (101) and flaps (103) are separated from each other by the trench line (TL)). Then, after the trench line (TL) becomes a slit (212), the flaps (101) and flaps (103) are separated from each other by the slit (212).

[0077] According to the above-described manufacturing method, an APG device having a zigzag pattern slit is formed.

[0078] Simply put, the present invention improves the asymmetry of air pulses by using a zigzag slit or a slit with a sawtooth edge, and thus improves the performance of an APG device.

[0079] Those skilled in the art will readily understand that numerous modifications and changes to the device and method may be made while maintaining the teachings of the present invention. Accordingly, the foregoing disclosure should be interpreted as being limited only by the scope and limitations of the appended claims.

Claims

Claim 1 A method for manufacturing an air pulse generating device, comprising the steps of: providing a wafer including a first layer and a second layer; patterning the first layer of the wafer to form a zigzag pattern slit; and removing a first portion of the second layer, wherein a portion of the first layer above the removed first portion of the second layer forms a film structure; the zigzag pattern slit separates the film structure into a first flap and a second flap; the zigzag pattern slit extends zigzag forward and backward between a first direction and a second direction toward the second direction; the first flap and the second flap are actuated to perform common mode movement and differential mode movement, wherein the differential mode movement forms a virtual valve in the slit, and the common mode movement generates an ultrasonic air pressure change to cause the air pulse generating device to generate an asymmetric air pressure pulse; and wherein the air pulse generating device acts on the film structure to generate a plurality of air pulses. Claim 2 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a first electrode and an operating material on the first layer of the wafer. Claim 3 A method for manufacturing an air pulse generating device according to claim 1, comprising the steps of: providing a first conductive layer and an operating material to the first layer of the wafer; and etching the first conductive layer and the operating material. Claim 4 A method for manufacturing an air pulse generating device according to paragraph 2, comprising the step of forming a second electrode on the operating material. Claim 5 A method for manufacturing an air pulse generating device according to claim 2, comprising the steps of: forming a second conductive layer on the working material through sputtering; and etching the second conductive layer. Claim 6 A method for manufacturing an air pulse generating device according to claim 1, wherein the slit includes a non-zero projection in the first direction. Claim 7 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the first flap includes a plurality of first protrusions and the second flap includes a plurality of second protrusions, wherein the first protrusions and the second protrusions are arranged alternately with each other. Claim 8 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the first flap includes a plurality of first protrusions and a plurality of first depressions, wherein the first protrusions and the first depressions are arranged alternately with each other. Claim 9 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the first flap includes a plurality of first protrusions, wherein one of the plurality of first protrusions includes a plateau portion. Claim 10 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the first flap includes a plurality of first protrusions, wherein one of the plurality of first protrusions corresponds to a width; and the width is greater than the height of the wall between the first flap and the second flap. Claim 11 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the first flap includes a plurality of first protrusions, wherein one of the plurality of first protrusions corresponds to a width; and the width is greater than the difference in displacement between the free ends of the first flap and the second flap when the virtual valve is opened. Claim 12 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the first flap includes a plurality of first protrusions, wherein one of the plurality of first protrusions corresponds to a depth; and the depth is greater than 15% of the anchor-to-anchor distance. Claim 13 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming the slit into a tooth edge pattern. Claim 14 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming the slit into a rectangular sawtooth edge pattern or a trapezoidal sawtooth edge pattern. Claim 15 A method for manufacturing an air pulse generating device according to claim 1, wherein the first flap and the second flap are actuated to perform differential movement to form an opening or a virtual valve, and the opening or the virtual valve is formed by the zigzag pattern slit. Claim 16 A method for manufacturing an air pulse generating device according to claim 15, wherein the virtual valve is in a closed state when the difference in displacement between the first flap and the second flap is smaller than the thickness of the film structure; and the closed state of the virtual valve occurs during the transition of the differential motion of the first flap and the second flap. Claim 17 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the area coverage ratio is not less than 0.

25. Claim 18 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming a zigzag pattern slit such that the area coverage ratio is not less than 0.

5. Claim 19 In claim 1, the method of manufacturing an air pulse generating device, wherein the air pulse generating device is applied to a sound generation application. Claim 20 A method for manufacturing an air pulse generating device according to claim 1, wherein the air pulse generating device is applied to an air movement application. Claim 21 A method for manufacturing an air pulse generating device according to claim 1, comprising the step of forming or providing a cover structure, wherein a chamber is formed between the film structure and the cover structure. Claim 22 A method for manufacturing an air pulse generating device according to claim 21, comprising the step of forming an orifice in the cover structure, wherein the plurality of air pulses propagate outward through the orifice.

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