Phased array synthetic jet microactuator device

Abstract

The application discloses a phased array synthetic jet micro-actuator device, which comprises a substrate, a substrate, a plurality of vibration units and a top cover; the plurality of vibration units are arranged in the space surrounded by the substrate frame along the transverse direction of the substrate; the diaphragm of the plurality of vibration units can generate vibration perpendicular to the surface of the substrate under an applied driving signal; and the input voltages of two adjacent vibration units are opposite; the upper surface of the substrate is sealingly connected with the top cover; the lower surface of the top cover and the vibration upper surface of the plurality of vibration units form a communication airflow channel; along the transverse direction of the substrate, air outlets which are in communication with the airflow channel are respectively arranged on the two end sidewalls of the top cover; along the transverse direction of the substrate, the substrate is provided with an air inlet which penetrates the thickness of the substrate; external airflow can be sucked into the airflow channel through the air inlet; and the vibration units and the air inlet are alternately and spacedly arranged along the transverse direction.

Description

Technical Field

[0001] This invention relates to the field of microelectromechanical systems (MEMS) technology, and more specifically to a phased array synthetic jet microactuator device. Background Technology

[0002] As compact electronic devices such as smartphones, tablets, and wearables evolve towards higher performance and greater integration, chip transistor density and computing power are continuously increasing. This has led to a dramatic increase in device power consumption and heat flux density, making localized overheating a key bottleneck restricting product performance, lifespan, and reliability. Related data shows that over half of electronic device failures are caused by overheating. Overheating not only causes chip frequency reduction and response delays but also accelerates material aging and reduces structural stability, necessitating efficient active thermal management solutions adapted to miniaturization scenarios.

[0003] Piezoelectric MEMS synthetic jet technology is considered a potential solution for active heat dissipation in microelectronic devices due to its advantages such as compact structure, no moving parts, low power consumption, and fast response. The basic principle of synthetic jet is to drive the periodic vibration of a membrane (such as a piezoelectric diaphragm) to alternately draw in and eject fluid into a cavity, thereby forming a jet at the outlet with zero net mass flow rate but non-zero momentum.

[0004] Currently, most existing MEMS synthetic jet array devices adopt an independent unit vertical air outlet mode, resulting in severe mutual interference and mixing of jets, poor directionality and concentration, making it difficult to form a concentrated directional airflow along the array axis, thus limiting the heat dissipation coverage and efficiency. The unit jet holes are mostly processed and assembled separately, resulting in low precision and poor sealing, which easily leads to airflow leakage and excessive flow resistance, resulting in low output flow and low back pressure. At the same time, the fixed unit spacing and the inability to coordinate and adjust the driving phase make it impossible to achieve efficient coupling and superposition of multiple jets through phase difference and array structure optimization, further limiting the controllability of the air outlet direction and the overall heat dissipation performance.

[0005] Existing MEMS synthetic jet devices mostly operate as single units or simple arrays, with the exhaust direction typically perpendicular to the chip surface. When multiple such units are simply arranged, the resulting multiple micro-jet streams interfere and mix with each other in the far field, making it difficult to form a concentrated, directional macroscopic airflow. This results in low heat dissipation efficiency and uncontrollable airflow coverage. Furthermore, the structural separation between units and the asynchrony of their driving also limit the effective superposition of the overall flow rate.

[0006] Therefore, there is an urgent need for a novel MEMS synthetic jet device that can efficiently couple multiple micro-jet streams to generate a concentrated directional airflow with controllable direction and flow rate, in order to meet the demand of advanced electronic devices for efficient and precise heat dissipation. Summary of the Invention

[0007] The present invention addresses the shortcomings of existing technologies by providing a phased array synthetic jet micro-actuator device. This device converts the vertical reciprocating flow generated by each unit into a lateral airflow by arranging multiple vibrating units laterally and precisely controlling the driving phase difference between adjacent vibrating units to 180°.

[0008] This invention provides a phased array synthetic jet micro-actuator device, comprising: a substrate, a base plate, multiple vibration units, and a top cover;

[0009] The substrate is a rectangular frame, the lower surface of which is sealed to the upper surface of the substrate;

[0010] The plurality of vibration units are arranged at lateral intervals along the substrate within the space enclosed by the substrate frame. Each vibration unit includes a silicon substrate and a diaphragm bonded to the upper surface of the silicon substrate, and the lower surface of the silicon substrate is bonded to the substrate. The diaphragms of the plurality of vibration units are capable of generating vibrations perpendicular to the substrate surface under an applied driving signal.

[0011] The top cover is sealed to the upper surface of the substrate, and the top cover covers the substrate and all the vibration units, thereby forming a cavity that accommodates each vibration unit together with the inner surface of the top cover and the substrate. Moreover, the height of the substrate is greater than the height of the vibration unit, so that there is a gap between the lower surface of the top cover and the upper surface of the diaphragm of the vibration unit, thereby forming a connected airflow channel on the lower surface of the top cover and the vibration upper surface of the multiple vibration units.

[0012] Along the transverse direction of the substrate, air outlets communicating with the airflow channel are respectively provided on the side walls at both ends of the top cover;

[0013] Along the transverse direction of the substrate, an air inlet penetrating its thickness is provided on the substrate, and external airflow can be drawn into the airflow channel through the air inlet; the vibration unit and the air inlet are arranged alternately along the transverse direction.

[0014] In this process, multiple vibration units are subjected to AC driving voltage, and adjacent vibration units are input with opposite phase voltages, so that the diaphragms of adjacent vibration units vibrate in opposite directions, thereby forming a periodic pressure distribution in the airflow channel; driven by the periodic pressure distribution, external airflow is alternately drawn in through the air inlet and ejected from the air outlets at both ends of the top cover.

[0015] Furthermore, the phase difference between the driving voltages input to two adjacent vibration units is 180 degrees, thereby forming a periodic pressure distribution within the airflow channel.

[0016] Furthermore, the diaphragm is a four-lobed diaphragm with a cross-shaped slit.

[0017] Furthermore, the air inlet is located between two adjacent vibration units and between the vibration units at both ends and the inner sidewall of the substrate.

[0018] Furthermore, the width of the air inlet is equal to the spacing between two adjacent vibration units, and the length of the air inlet is equal to the length of the vibration unit.

[0019] Furthermore, the top cover is made of stainless steel.

[0020] Furthermore, the actuator device also includes a conductor solder ball disposed on the upper surface of the substrate and adjacent to the vibration unit. The upper surface of the substrate is provided with a metal layer, which is electrically connected to the conductor solder ball and the vibration unit through a metal wire for transmitting drive signals.

[0021] Furthermore, the device is positioned above the heat dissipation target body to be cooled, with the heat dissipation target body being 0.5-2 mm away from the substrate.

[0022] Furthermore, the upper surface of the top cover of the device is positioned in contact with the heat dissipation target to be cooled.

[0023] More preferably, the top surface of the top cover and the heat dissipation target are thermally connected by a thermally conductive interface material. Preferably, the thermally conductive interface material is thermally conductive silicone.

[0024] Furthermore, the device is positioned between two heat dissipation targets; more preferably, the air outlets at both ends of the top cover are aligned with the high heat flux density regions of the heat dissipation targets.

[0025] The beneficial effects of this invention are as follows:

[0026] By arranging multiple vibration units laterally and precisely controlling the driving phase difference between adjacent vibration units to 180°, the vertical reciprocating flow generated by each unit is cleverly transformed into a directional airflow along the array arrangement direction through far-field coupling, changing the traditional MEMS synthetic jet pattern where air can only be discharged vertically.

[0027] The coordinated operation of phased arrays enables multiple tiny jets to achieve momentum superposition in the lateral direction, thereby generating a much larger concentrated gas flow rate than a single unit or in-phase array, significantly enhancing heat dissipation capacity.

[0028] The vibration unit and airflow channel are integrated and manufactured in the cavity between the substrate and the top cover. The structure is regular and does not require complex independent assembly, making the overall thickness of the device thinner. It is very suitable for consumer electronics products that are extremely sensitive to space.

[0029] Moreover, by changing the number and spacing of the vibration units, the direction, concentration and effective distance of the final synthesized jet can be flexibly controlled, thereby achieving precise and efficient heat dissipation for heat sources of different locations and shapes. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the working principle of the phased array synthetic jet micro-actuator device described in Example 1 during the jetting stage;

[0031] Figure 2 This is a schematic diagram of the working principle of the phased array synthetic jet micro-actuator device described in Example 1 during the air intake stage;

[0032] Figure 3 This is a schematic diagram of the layout for simulation experiments using the phased array synthetic jet micro-actuator device to form an actuator array in Embodiment 1;

[0033] Figure 4 yes Figure 3 The diagram shows the flow detection at both ends of the microchannel in the simulation experiment.

[0034] Figure 5 This is a top view of the phased array synthetic jet micro-actuator device described in Example 1;

[0035] Figure 6 This is a cross-sectional schematic diagram of the phased array synthetic jet micro-actuator device described in Example 2 applied to a near-field heat dissipation scenario;

[0036] Figure 7 This is a cross-sectional schematic diagram of the phased array synthetic jet micro-actuator device described in Example 3 applied to a contact heat dissipation scenario;

[0037] Figure 8 This is a cross-sectional schematic diagram of the phased array synthetic jet micro-actuator device described in Example 4 applied to a multi-target heat dissipation scenario.

[0038] in,

[0039] P1: Substrate; S01: Silicon substrate; LH11: Air inlet; TL01: Top cover; S11: Substrate; FM: Diaphragm; AT1: First vibration unit; AT2: Second vibration unit; AT3: Third vibration unit; AT4: Fourth vibration unit; AT5: Fifth vibration unit; LH01: Air outlet; CHP1, CHP2: Heat dissipation target; MB01: Conductor solder ball. Detailed Implementation

[0040] To make the objectives, technical solutions, beneficial effects, and significant advancements of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings provided in the examples of the present invention. Obviously, all the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this application, unless otherwise expressly specified and limited, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more; unless otherwise specified or explained, the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] It should be noted that in this invention, "lateral" refers to the direction along which the vibrating units are arranged. "Vertical direction" refers to the approximately perpendicular direction from the top cover to the surface of the substrate.

[0043] Example 1

[0044] like Figure 1 , Figure 2 , Figure 5 As shown, a phased array synthetic jet micro-actuator device includes: a substrate P1, a substrate S11, multiple vibration units, and a top cover TL01. The substrate P1 is a printed circuit board on which necessary driving circuits can be integrated. The substrate S11 is bonded to the upper surface of the substrate P1. The substrate S11 is a rectangular frame. Inside the substrate S11, 1x3 vibration units (first vibration unit AT1, second vibration unit AT2, and third vibration unit AT3) are arranged laterally along the substrate P1, and an air inlet LH11 is provided. An air inlet LH11 is also provided between the vibration units at both ends and the substrate S11. The top cover TL01 is sealed to the upper surface of the substrate S11, and the top cover covers the substrate and all the vibration units. The height of the substrate is greater than the height of the vibration units, so that the lower surface of the top cover TL01 is spaced from the upper surface of the vibration units to form an airflow channel. The top cover TL01 and the inner surface of the substrate S11 together form an independent cavity to accommodate each vibration unit. Furthermore, along the transverse direction of the substrate P1, openings are respectively provided on the side walls at both ends of the top cover TL01 as air outlets LH01 (i.e. Figure 1 (The seam between the leftmost and rightmost points shown).

[0045] The vibration unit includes a silicon substrate S01 and a diaphragm FM bonded to the upper surface of the silicon substrate. The bottom of the silicon substrate S01 is bonded to the substrate P1. Each diaphragm is a four-lobed diaphragm with a cross-shaped slit, and the phase difference between two adjacent vibration units is 180°. This embodiment is only an example; the number of substrates, the spacing between diaphragms, the number of diaphragms, and the specific structure of the diaphragms can all be varied. To achieve efficient airflow circulation, the substrate P1 has multiple air inlets LH11 evenly spaced along the arrangement direction of the diaphragms FM in the vibration unit, serving as the main air inlets of the device. The width of each air inlet LH11 is the interval between two adjacent vibration units, and the length of each air inlet is equal to the length of the vibration unit, together forming a through-flow air intake channel. Figure 5 As shown, the vibrating units and air inlets LH11 are arranged alternately. This "vibrating unit-through-vibrating unit" spacing design ensures that the air intake path below the cavity corresponding to each vibrating unit is independent and balanced. When the diaphragm vibrates, external cooling air can be smoothly drawn in or discharged through the air inlets LH11 located between the vibrating units, minimizing airflow interference between the diaphragms and providing an optimized flow channel foundation for multiple units to work together to form a stable axial directional jet.

[0046] Furthermore, the top cover TL01 is made of stainless steel. The upper surface of the substrate P1 is a metal layer, which is integrated onto the upper surface of the substrate P1. Conductor solder balls MB01 are also fixedly connected to the upper surface of the substrate P1, and the conductor solder balls MB01 are positioned adjacent to the vibration unit; the metal layer and the conductor solder balls MB01 are connected by metal wires, thereby realizing electrical signal interaction between the vibration unit and the substrate.

[0047] The actuator operates as follows:

[0048] An AC driving voltage of the same frequency and phase is applied to each of the vibration units;

[0049] During the injection phase, such as Figure 1 As shown, the vibrating ends of the diaphragms FM of the first vibration unit AT1 and the third vibration unit AT3 move toward the substrate P1, while the second vibration unit AT2 in the middle moves toward the top cover TL01. At this time, a low-pressure region is formed between the diaphragms of the first vibration unit AT1 and the third vibration unit AT3 and the top cover TL01 above them, and a high-pressure region is formed between the diaphragm FM of the second vibration unit AT2 and the top cover TL01 above it. Under the action of the high and low pressure difference, the airflow flows from the high-pressure region to the low-pressure region, thereby reaching the vicinity of the air outlets LH01 located on both sides of the top cover TL01.

[0050] During the inhalation phase, such as Figure 2 As shown, the vibrating ends of the diaphragms of the first vibration unit AT1 and the third vibration unit AT3 move toward the top cover TL01, while the second vibration unit AT2 in the middle moves toward the substrate P1. At this time, a high-pressure region is formed between the diaphragms of the first vibration unit AT1 and the third vibration unit AT3 and the top cover TL01 above them, and a low-pressure region is formed between the diaphragm of the second vibration unit AT2 and the top cover TL01 above it. External airflow enters the actuator device from the air inlet LH11 between the substrates P1.

[0051] Of course, during the inhalation phase, the diaphragms of the first vibration unit AT1 and the third vibration unit AT3 can also be in a static state, that is, neither moving upward nor upward.

[0052] Simulation Experiment

[0053] like Figure 3 As shown, an actuator device includes four evenly spaced vibration units: a first vibration unit AT1, a second vibration unit AT2, a third vibration unit AT3, and a fourth vibration unit AT4, forming an actuator array. To generate a pressure difference within the actuator device, the phase difference between adjacent vibration units is π / 2. Below the actuator device is a microchannel for airflow discharge and detection of airflow direction and flow rate; the actuator device is capable of generating airflow arranged laterally within it. Figure 4 The diagram shows that airflow of a certain flow rate is generated at both ends of the microchannel to verify the feasibility of the actuator device of the present invention being able to change the airflow direction.

[0054] Example 2

[0055] like Figure 6 As shown, a phased array synthetic jet micro-actuator device includes a substrate P1, a substrate S11, three vibration units, and a top cover TL01. The structure of the phased array synthetic jet micro-actuator device is basically the same as that of Embodiment 1, except that the air inlet LH11 is a slit. The same parts will not be described again.

[0056] A heat dissipation target CHP1 is disposed below the substrate P1, and the heat dissipation target CHP1 is 0.5-1 mm away from the substrate P1. When the phased array synthetic jet micro-actuator device is inhaling air, the heat from the heat dissipation target CHP1 is continuously drawn into the micro-actuator device through the air inlet LH11 between the micro-actuator devices, and blown out through the air outlet LH01 during the jetting phase.

[0057] The top cover TL01 is made of stainless steel.

[0058] This design, which exhausts air through side gaps, effectively avoids air pressure stagnation caused by the central area being sealed, ensuring the independence of airflow and efficient directional injection between arrayed micro-actuator devices, and improving the efficiency and controllability of the synthetic jet.

[0059] Example 3

[0060] like Figure 7 As shown, a phased array synthetic jet micro-actuator device includes a substrate P1, a substrate S11, four vibration units, and a top cover TL01. The structure of the phased array synthetic jet micro-actuator device is basically the same as that of Embodiment 1, except that it includes four vibration units, which are arranged from left to right along the substrate P1 as the first vibration unit AT1, the second vibration unit AT2, the third vibration unit AT3, and the fourth vibration unit AT4. The identical parts will not be described again.

[0061] A heat dissipation target body CHP1 is tightly attached to the top surface of the top cover TL01, and a layer of thermally conductive silicone is provided between the top surface of the top cover TL01 and the heat dissipation target body CHP1 to enhance heat conduction. It is understood that the thermally conductive silicone can also be replaced with other common thermal interface materials in the art, such as thermal pads, thermal paste, phase change materials, etc., to achieve thermal connection between the top cover and the heat dissipation target body. During the adsorption stage of the phased array synthetic jet micro-actuator device, the vibrating ends of the diaphragms FM of the first and third vibration units move towards the substrate P1, and the vibrating ends of the diaphragms of the second and fourth vibration units move towards the top cover TL01, resulting in a certain phase difference between each vibration unit; the heat on the heat dissipation target body CHP1 is conducted to the top cover TL01, and then transferred to the phased array synthetic jet micro-actuator device; during the jetting stage, the diaphragms of each vibration unit move in opposite directions, and finally are blown out through the air outlets LH01 at both ends of the phased array synthetic jet micro-actuator device.

[0062] Example 4

[0063] like Figure 8 As shown, a phased array synthetic jet micro-actuator device includes a substrate P1, a substrate S11, five vibration units, and a top cover TL01. The structure of the phased array synthetic jet micro-actuator device is basically the same as that of Embodiment 1, except that it includes five vibration units, which are arranged from left to right along the substrate P1 as the first vibration unit AT1, the second vibration unit AT2, the third vibration unit AT3, the fourth vibration unit AT4, and the fifth vibration unit AT5. The identical parts will not be described again.

[0064] At both ends of the phased array synthetic jet micro-actuator device, i.e., at both ends along the transverse direction of the substrate P1, heat dissipation targets CHP1 and CHP2 are respectively provided; the heat dissipation targets CHP1 and CHP2 are 1-3 mm away from the substrate S11. During the air intake phase of the phased array synthetic jet micro-actuator device, the vibrating ends of the diaphragms of the first, third, and fifth vibration units move towards the substrate P1, and the vibrating ends of the diaphragms of the second and fourth vibration units move towards the top cover TL01, so that each vibration unit has a certain phase difference, and no heat is drawn into the phased array synthetic jet micro-actuator device during the air intake phase. During the jetting phase, the diaphragms of each vibration unit move in opposite directions, blowing air out through the air outlets LH01 at both ends of the phased array synthetic jet micro-actuator device, blowing towards the heat dissipation targets CHP1 and CHP2 located at the air outlets, exchanging heat with them, thereby dissipating heat.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A phased array synthetic jet microactuator device, characterized in that, include: Substrate (P1), substrate (S11), multiple vibration units and top cover (TL01). The substrate (S11) is a rectangular frame, and its lower surface is sealed to the upper surface of the substrate (P1). Multiple vibration units are arranged at lateral intervals along the substrate (P1) within the space enclosed by the substrate (S11) frame. Each vibration unit includes a silicon substrate (S01) and a diaphragm (FM) bonded to the upper surface of the silicon substrate (S01). The lower surface of the silicon substrate is bonded to the substrate (P1). The diaphragm (FM) of the vibration unit is capable of generating vibration perpendicular to the surface of the substrate (P1) under an applied driving signal. The top cover (TL01) is sealed to the upper surface of the substrate (S11). The top cover (TL01) covers the substrate (S11) and all the vibration units, thereby forming a cavity for accommodating each vibration unit together with the inner surface of the top cover (TL01) and the substrate (S11). Moreover, the height of the substrate (S11) is greater than the height of the vibration unit, so that there is a gap between the lower surface of the top cover (TL01) and the upper surface of the diaphragm (FM) of the vibration unit, thereby forming a connected airflow channel on the lower surface of the top cover (TL01) and the vibrating upper surfaces of the multiple vibration units. Along the transverse direction of the substrate (P1), air outlets (LH01) communicating with the airflow channel are respectively opened on the side walls of both ends of the top cover (TL01). Along the transverse direction of the substrate (P1), an air inlet (LH11) penetrating its thickness is provided on the substrate (P1), and external airflow can be drawn into the airflow channel through the air inlet (LH11); the vibration unit and the air inlet (LH11) are arranged alternately along the transverse direction. In this process, multiple vibration units are subjected to AC driving voltage, and adjacent vibration units are input with opposite phase voltages, so that the diaphragms (FM) of adjacent vibration units vibrate in opposite directions, thereby forming a periodic pressure distribution in the airflow channel; driven by the periodic pressure distribution, external airflow is alternately drawn in through the air inlet (LH11) and ejected from the air outlets (LH01) at both ends of the top cover (TL01).

2. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The diaphragm is a four-lobed diaphragm with a cross-shaped slit.

3. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The air inlet (LH11) is located between two adjacent vibration units and between the vibration units at both ends and the inner sidewall of the substrate.

4. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The width of the air inlet (LH11) is equal to the spacing between two adjacent vibration units, and the length of the air inlet (LH11) is equal to the length of the vibration unit.

5. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The top cover (TL01) is made of stainless steel.

6. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The actuator device further includes a conductor solder ball (MB01) disposed on the upper surface of the substrate (P1) and adjacent to the vibration unit. The upper surface of the substrate (P1) is provided with a metal layer, which is electrically connected to the conductor solder ball (MB01) and the vibration unit through a metal wire for transmitting drive signals.

7. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The device is positioned above the heat dissipation target (CHP1) to be cooled, and the heat dissipation target (CHP1) is 0.5-2 mm away from the substrate (P1).

8. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The upper surface of the top cover (TL01) of the device is in contact with the heat dissipation target (CHP1) to be dissipated.

9. The phased array synthetic jet microactuator device according to claim 8, characterized in that, The top surface of the top cover (TL01) and the heat dissipation target (CHP1) are thermally connected by a thermally conductive interface material.

10. The phased array synthetic jet microactuator device according to claim 1, characterized in that, The device is positioned between two heat dissipation targets.

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