A MEMS chip heat spreader

Abstract

The application discloses a MEMS chip radiator, which comprises a driving power supply, a frame and a cover plate arranged on the frame, the frame is provided with a swing piece and an air inlet, the swing piece is provided with a first conductive layer, the cover plate is provided with an air outlet and an inner surface is provided with a second conductive layer, the second conductive layer is arranged correspondingly with the first conductive layer, the driving power supply is connected with the first conductive layer and the second conductive layer, and the swing piece is driven to vibrate in a resonance state through electrostatic driving mode. The traditional radiator fan is compressed to the chip level, and can be installed in a compact mobile device. Through simple electrostatic driving, the swing piece is vibrated in a resonance state, the swing piece drives the air flow around the swing piece, promotes heat exchange, carries away the excess heat on the chip to be cooled, and the overall structure is simple, small in size, low in noise during operation and good in cooling effect.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation equipment technology for compact electronic devices, and more particularly to a MEMS chip heat sink. Background Technology

[0002] Compact mobile devices urgently need more efficient cooling systems, such as 5G connectivity, spatial computing, high-resolution video and gaming, and edge applications of artificial intelligence. This makes heat dissipation a major bottleneck restricting the performance of size- and weight-sensitive devices like smartphones.

[0003] While traditional cooling fans offer good heat dissipation, they are generally large and heavy, and generate noise during operation, making them unsuitable for compact mobile devices. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a MEMS chip heat sink with simple structure, small size, low noise during operation and good cooling effect.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A MEMS chip heat sink includes a driving power supply, a frame, and a cover plate disposed on the frame. The frame is provided with a swing plate and an air inlet. The swing plate is provided with a first conductive layer. The cover plate is provided with an air outlet and a second conductive layer on its inner surface. The second conductive layer is arranged correspondingly to the first conductive layer to form a planar capacitor structure. The driving power supply is connected to the first conductive layer and the second conductive layer and drives the swing plate to vibrate in a resonant state by electrostatic driving.

[0007] As a further improvement to the above technical solution: the frame includes a central beam, and the swing pieces are provided in at least one set, each set of the swing pieces including two pieces and symmetrically arranged on both sides of the central beam.

[0008] As a further improvement to the above technical solution: the pendulum is connected to the central beam via a vibrating beam.

[0009] As a further improvement to the above technical solution: the cross-section of the vibrating beam is polygonal.

[0010] As a further improvement to the above technical solution: the frame is provided with a first conductive pad at at least one end, the first conductive pad is formed by photolithography metallization deposition, the vibration beam and the center beam are formed by photolithography metallization deposition to form a first conductive line for connecting the first conductive layer and the first conductive pad, and the first conductive pad is connected to the driving power supply.

[0011] As a further improvement to the above technical solution: the cover plate is provided with a clearance portion for the first conductive pad to pass through.

[0012] As a further improvement to the above technical solution: the vibration beam is formed by wet etching and / or dry etching.

[0013] As a further improvement to the above technical solution: the outer surface of the cover plate is provided with a second conductive pad, which is formed by photolithography metallization deposition. The inner surface of the cover plate is formed with a second conductive line by photolithography metallization deposition. One end of the second conductive line is connected to the second conductive layer, and the other end of the second conductive line is connected to the second conductive pad through a metallized via. The second conductive pad is connected to the driving power supply.

[0014] As a further improvement to the above technical solution: the cover plate is made of electronic glass or high-purity quartz, and the frame is made of single-crystal silicon or high-purity quartz.

[0015] As a further improvement to the above technical solution: the cover plate, frame and slab are all formed by photolithography wet etching, dry etching or laser etching, and the first conductive layer and the second conductive layer are formed by photolithography metallization deposition.

[0016] Compared with the prior art, the advantages of the present invention are as follows:

[0017] The MEMS chip heat sink disclosed in this invention compresses the traditional cooling fan to the chip level, allowing it to be installed in compact mobile devices. Through simple electrostatic drive, the pendulum vibrates in a resonant state, driving the airflow around it to promote heat exchange. Cool air enters from the air inlet, absorbs the heat from the chip, and then exits from the air outlet, carrying away excess heat from the cooled chip. The overall structure is simple, small in size, operates with low noise, and has a good cooling effect.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural schematic diagram of the first embodiment of the MEMS chip heat sink of the present invention.

[0020] Figure 2 This is a three-dimensional structural diagram of the cover plate in Embodiment 1 of the present invention.

[0021] Figure 3 This is a three-dimensional structural diagram of the frame in Embodiment 1 of the present invention.

[0022] Figure 4This is a three-dimensional structural schematic diagram of the second embodiment of the MEMS chip heat sink of the present invention.

[0023] Figure 5 This is a schematic diagram of the frame structure in Embodiment 2 of the present invention.

[0024] The labels in the diagram represent:

[0025] 1. Cover plate; 11. Second conductive line; 12. Second conductive layer; 13. Clearance part; 14. Second conductive pad; 15. Air outlet; 2. Frame; 21. Central beam; 23. First conductive line; 24. First conductive pad; 25. Air inlet; 3. Sway bar; 31. First conductive layer. Detailed Implementation

[0026] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figures 1 to 5As shown, the MEMS chip heat sink of this embodiment includes a driving power supply (not shown in the figure), a frame 2, and a cover plate 1 disposed on the frame 2. The frame 2 is provided with a swing plate 3 and an air inlet 25. The swing plate 3 is provided with a first conductive layer 31. The cover plate 1 is provided with an air outlet 15. The inner surface of the cover plate 1 (i.e., the side facing the frame 2) is provided with a second conductive layer 12. The second conductive layer 12 is arranged correspondingly to the first conductive layer 31 to form a planar capacitor structure. The driving power supply is connected to the first conductive layer 31 and the second conductive layer 12, and drives the swing plate 3 to vibrate in a resonant state through electrostatic driving. Here, MEMS stands for Micro-Electro-Mechanical Systems. Preferably, the frame 2 is also a planar structure, which occupies little space and is convenient to install in compact mobile devices. The air inlet 25 and the air outlet 15 are elongated holes and are respectively disposed on the side surface of the frame 2 and the upper surface of the cover plate 1, with a large flow area, which facilitates the entry of cold air into the interior of the frame 2 and the exhaust of hot air to the exterior of the cover plate 1.

[0031] The MEMS chip heat sink of this embodiment compresses the traditional cooling fan to the chip level, allowing it to be installed in compact mobile devices. Through simple electrostatic actuation (when a voltage is applied between two electrodes, an electrostatic field is generated between them. If one electrode is movable, it will be attracted or repelled by the electrostatic field, thus changing its position. Electrostatic actuation offers low power consumption, high energy efficiency, very precise control, and fast response), the pendulum 3 vibrates in a resonant state. The pendulum 3 drives the airflow around it, promoting heat exchange. Cool air enters through the air inlet 25, absorbing heat from the chip, and then exits through the air outlet 15, carrying away excess heat from the cooled chip. The overall structure is simple, small in size, operates with low noise, and provides excellent cooling.

[0032] See details Figure 3 In this embodiment, the frame 2 includes a central beam 21, and two sets of swing plates 3 are provided and distributed along the length of the central beam 21. Each set includes two swing plates 3 and is symmetrically arranged on both sides of the central beam 21. Correspondingly, the second conductive layer 12 on the cover plate 1 is also set in two sets. The symmetry and balance are good, which is conducive to the reliable and stable operation of the heat sink.

[0033] Of course, in other embodiments, see details. Figure 4 and 5 The three oscillating plates can also be set in three or more groups in parallel, and can even be stacked if necessary to achieve the desired cooling effect.

[0034] In a preferred embodiment, the pendulum 3 is connected to the central beam 21 via a vibrating beam, which facilitates high-frequency oscillation of the pendulum 3 and further improves the heat dissipation effect.

[0035] As a preferred embodiment, the cross-section of the vibrating beam is polygonal, such as a convex quadrilateral or hexagon, and commonly parallelograms, rectangles, squares, etc., which will not be described in detail here.

[0036] Furthermore, in this embodiment, the frame 2 has first conductive pads 24 at both ends, which are formed by photolithography metallization deposition. The central beam 21 is located between the first conductive pads 24 at both ends. The vibration beam and the central beam 21 form first conductive lines 23 by photolithography metallization deposition, which are used to connect the first conductive layer 31 and the first conductive pads 24. The first conductive pads 24 are connected to the driving power supply, thereby realizing the connection between the first conductive layer 31 and the driving power supply. This does not excessively increase the number of components, resulting in an increase in the size and weight of the heat sink. The structure is reasonable and effective. The two pairs of swing plates 3 can be connected to the first conductive pads 24 in close proximity.

[0037] Furthermore, in this embodiment, the cover plate 1 is provided with a clearance portion 13 for the first conductive pad 24 to pass through, which facilitates the connection of the first conductive pad 24 to the driving power supply. Preferably, the clearance portion 13 is an arc-shaped notch structure and is provided at both ends of the upper surface of the cover plate 1.

[0038] The vibrating beam can be made by wet etching, dry etching, or a combination of both.

[0039] See details Figure 2 In this embodiment, a second conductive pad 14 is provided on the outer surface of the cover plate 1. The second conductive pad 14 is formed by photolithography metallization deposition. A second conductive line 11 is formed on the inner surface of the cover plate 1 by photolithography metallization deposition. One end of the second conductive line 11 is connected to the second conductive layer 12, and the other end of the second conductive line 11 is connected to the second conductive pad 14 through a metallized via. The second conductive pad 14 is connected to the driving power supply, thereby realizing the connection between the second conductive layer 12 and the driving power supply. This does not excessively increase the number of components, resulting in an increase in the volume and weight of the heat sink. The structure is reasonable and effective.

[0040] Preferably, the cover plate 1 is made of electronic glass or high-purity quartz (i.e., silicon dioxide purity above 99.995%), and the frame 2 is made of monocrystalline silicon or high-purity quartz. The use of materials such as electronic glass, monocrystalline silicon, or high-purity quartz ensures good compatibility between the production process and MEMS technology. Furthermore, monocrystalline silicon or high-purity quartz possesses excellent physical properties, allowing the heat sink (mainly the swivel plate 3) to withstand long-term heat dissipation without fatigue damage.

[0041] Furthermore, in this embodiment, the cover plate 1 (including the air outlet 15 on the cover plate 1), the frame 2, and the oscillating plate 3 are all formed by wet etching, dry etching, or laser etching, and the first conductive layer 31 and the second conductive layer 12 are formed by photolithographic metallization deposition. By using processes such as wet etching, dry etching, or laser etching, the micro-sized oscillating plate 3 can be easily released; electrodes driving the oscillating plate 3 can be formed on the surface of the oscillating plate 3 and the inner surface of the cover plate 1 by chemical and physical deposition methods.

[0042] The frame 2 and cover plate 1 can be cut into products after bonding, or they can be assembled with the target cooling chip at the wafer level.

[0043] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A MEMS chip heat sink, characterized in that: The device includes a driving power supply, a frame (2), and a cover plate (1) disposed on the frame (2). The frame (2) is provided with a swing plate (3) and an air inlet (25). The swing plate (3) is provided with a first conductive layer (31). The cover plate (1) is provided with an air outlet (15) and a second conductive layer (12) is provided on its inner surface. The second conductive layer (12) is arranged correspondingly to the first conductive layer (31). The driving power supply is connected to the first conductive layer (31) and the second conductive layer (12) and drives the swing plate (3) to vibrate in a resonant state by electrostatic driving. The cover plate (1), the frame (2), and the swing plate (3) are all formed by photolithography wet etching, dry etching, or laser etching. The first conductive layer (31) and the second conductive layer (12) are formed by photolithography metallization deposition.

2. The MEMS chip heat sink according to claim 1, characterized in that: The frame (2) includes a central beam (21), and the pendulum pieces (3) are provided with at least one set, each set of the pendulum pieces (3) including two pieces and symmetrically arranged on both sides of the central beam (21).

3. The MEMS chip heat sink according to claim 2, characterized in that: The pendulum (3) is connected to the central beam (21) via a vibrating beam.

4. The MEMS chip heat sink according to claim 3, characterized in that: The cross-section of the vibrating beam is polygonal.

5. The MEMS chip heat sink according to claim 3, characterized in that: The frame (2) has a first conductive pad (24) at at least one end. The first conductive pad (24) is formed by photolithography metallization deposition. The vibration beam and the center beam (21) form a first conductive line (23) by photolithography metallization deposition, which is used to connect the first conductive layer (31) and the first conductive pad (24). The first conductive pad (24) is connected to the driving power supply.

6. The MEMS chip heat sink according to claim 5, characterized in that: The cover plate (1) is provided with a clearance part (13) for the first conductive pad (24) to pass through.

7. The MEMS chip heat sink according to claim 3, characterized in that: The vibrating beam is formed by wet etching and / or dry etching.

8. The MEMS chip heat sink according to claim 1, characterized in that: The outer surface of the cover plate (1) is provided with a second conductive pad (14), which is formed by photolithography metallization deposition. The inner surface of the cover plate (1) is formed by photolithography metallization deposition of a second conductive line (11). One end of the second conductive line (11) is connected to the second conductive layer (12), and the other end of the second conductive line (11) is connected to the second conductive pad (14) through a metallized via. The second conductive pad (14) is connected to the driving power supply.

9. The MEMS chip heat sink according to any one of claims 1 to 8, characterized in that: The cover plate (1) is made of electronic glass or high-purity quartz, and the frame (2) is made of monocrystalline silicon or high-purity quartz.

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