Temperature-pressure response adaptive micro-channel heat sink

Abstract

The application discloses a temperature-pressure response self-adaptive micro-channel radiator, which comprises a heat dissipation core body, a sealed shell and a self-adaptive flow adjusting structure arranged in the heat dissipation core body; the heat dissipation core body is integrally formed by a semiconductor substrate, and a central liquid inlet cavity and a plurality of branch flow channels extending from the central liquid inlet cavity to the periphery are arranged in the heat dissipation core body; the self-adaptive flow adjusting structure is arranged at a connecting area of the central liquid inlet cavity and the branch flow channels, and is integrally formed with the heat dissipation core body by using a homogeneous material; the self-adaptive flow adjusting structure comprises a fixed end and first and second elastic flaps extended from the fixed end; the elastic flaps can be elastically deformed under the action of cooling medium pressure and thermal stress generated by a non-uniform temperature field, so as to change the flow area of the branch flow channels and realize self-adaptive adjustment of the flow of the cooling medium. The self-adaptive micro-channel radiator can adjust the cooling path according to the change of heat load without an external control system, improves the heat dissipation capacity of a hot spot area, has the advantages of high structural integration and good reliability, and can be applied to the field of heat dissipation of high-power semiconductor devices.

Description

Technical Field

[0001] This invention relates to the field of semiconductor heat dissipation and microelectromechanical systems (MEMS) technology, and specifically to a temperature and pressure responsive adaptive microchannel heat sink based on semiconductor substrate micromachining. Background Technology

[0002] With the development of artificial intelligence chips, high-performance processors, high-power semiconductor devices, and high-frequency radio frequency devices, the integration density and operating power of electronic devices are constantly increasing, leading to a continuous increase in heat generated per unit area. During high-power operation, different regions within the chip are prone to forming localized heat concentration areas, i.e., hot spots, due to differences in functional load. If these hot spots are not effectively cooled in a timely manner, it will lead to a decline in device performance, reduced reliability, and even affect the device's lifespan.

[0003] The main heat dissipation methods for high heat flux density electronic devices include air cooling, liquid cooling, and microchannel cooling. Among them, microchannel cooling technology, by setting microscale flow channels inside the heat sink substrate, allows the cooling medium to flow directly through the area near the heat source, thereby improving heat dissipation efficiency and has become an important technical direction for solving the heat dissipation problem of high power density devices.

[0004] Existing microchannel heat dissipation structures typically employ a fixed flow channel design, where the internal channel dimensions and coolant distribution ratio remain unchanged after fabrication. However, when electronic devices operate under different conditions, the internal heat distribution of the chip changes. Traditional microchannel structures cannot actively adjust the coolant flow rate based on local temperature variations, easily leading to insufficient cooling in high-temperature areas and excessive utilization of the cooling medium in low-temperature areas. To achieve dynamic coolant flow rate regulation, some existing technologies employ solenoid valves, temperature sensors, and control systems to actively control the microchannel. Furthermore, some existing MEMS microfluidic control structures use combinations of different materials to form flexible control elements. Due to the differences in thermal expansion coefficients between these materials, interfacial stress can easily occur under long-term temperature cycling and fluid impact, leading to structural fatigue, delamination, or failure. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings and deficiencies of existing technologies by providing a temperature and pressure response adaptive microchannel heat sink. By incorporating a temperature and pressure response cantilever flow regulation structure integrally formed with the silicon-based heat sink core, the cooling medium can achieve passive adaptive flow regulation according to changes in heat load, thereby improving the local heat dissipation capacity of high-power semiconductor devices, while reducing structural complexity and enhancing the reliability of the microchannel heat sink.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: it includes a heat dissipation core 200, a sealed outer shell 100, and an adaptive flow regulation structure 300 disposed inside the heat dissipation core 200, wherein a microchannel structure is disposed inside the heat dissipation core 200.

[0007] The sealed outer shell 100 covers the periphery of the heat dissipation core 200 and together with the heat dissipation core 200 forms a sealed cooling cavity. The sealed outer shell 100 is provided with a liquid inlet 101 and a liquid outlet 102 that communicate with the microchannel structure.

[0008] The microchannel structure includes a central liquid inlet chamber 201 disposed in the central region of the heat dissipation core 200 and a plurality of branch flow channels 202 extending outward from the central liquid inlet chamber 201.

[0009] The adaptive flow adjustment structure 300 is disposed in the connection area between the central liquid inlet chamber 201 and the branch flow channel 202, and is integrally formed with the semiconductor substrate using the same material;

[0010] The adaptive flow regulation structure 300 can undergo elastic deformation under the pressure of the cooling medium flowing through the microchannel structure and the thermal stress generated by the non-uniform temperature field inside the heat dissipation core 200, so as to change the flow area of ​​the corresponding branch channel 202 and thereby adjust the flow distribution of the cooling medium between different branch channels 202.

[0011] The heat dissipation core 200 is configured in two sets, with the two sets of heat dissipation cores 200 arranged concentrically side by side and rotated and staggered relative to each other around a common center, with a rotational stagger angle of 30-60°; a through liquid storage ring 400 is provided on the outer side of the two sets of heat dissipation cores 200, and the two sides of the liquid storage ring 400 are connected to the liquid outlet interface 102.

[0012] The adaptive flow control structure 300 includes a fixed end 301 and a cantilever throttling plate 302 extending from the fixed end 301 toward the central liquid inlet chamber 201; the cantilever throttling plate 302 is located in the intersection area of ​​the central liquid inlet chamber 201 and the branch flow channel 202.

[0013] The cantilever throttling vane 302 includes a first elastic vane 3021 and a second elastic vane 3022; the first elastic vane 3021 and the second elastic vane 3022 are integrally formed with the fixed end 301, and the first elastic vane 3021 and the second elastic vane 3022 are respectively disposed on both sides of the central liquid inlet cavity 201; the first elastic vane 3021 and the second elastic vane 3022 form a symmetrical suspended structure and fit together in the undriven state, and form coolant flow gaps with the corresponding branch channels 202 respectively.

[0014] When the first elastic wing 3021 and the second elastic wing 3022 are deformed under the combined action of temperature field and fluid pressure, the first elastic wing 3021 and the second elastic wing 3022 bend outward, increasing the force and heat dissipation area of ​​the elastic wing, thereby increasing the flow cross-sectional area of ​​the main flow channel 203 towards the target heat dissipation area, so as to guide the cooling medium to concentrate in the high heat load area.

[0015] The thickness of the cantilever throttling plate 302 varies in a gradient along the direction from the fixed end 301 to the end 303 of the throttling plate, and the thickness of the region near the fixed end 301 is greater than the thickness of the region near the free end 303, so as to improve the temperature and pressure response sensitivity of the cantilever throttling plate 302.

[0016] The liquid-facing surface of the cantilever throttling plate 302 is provided with a plurality of drag-reducing holes 3023; the plurality of drag-reducing holes 3023 are evenly arranged along the direction from the fixed end 301 to the end of the throttling plate 303, and the drag-reducing holes 3023 reduce the flow resistance generated when the cooling medium flows through the cantilever throttling plate 302.

[0017] The fixed end 301 of the cantilever throttling plate 302 is provided with a stress relief structure 304; the stress relief structure 304 is an arc-shaped groove, and the stress relief structure 304 is used to reduce the stress concentration in the root region of the cantilever throttling plate 302.

[0018] The microchannel structure includes a primary branch channel 202, a secondary branch channel 203, and a tertiary branch channel 204 extending outward from the central liquid inlet chamber 201; the primary branch channel 202, the secondary branch channel 203, and the tertiary branch channel 204 are arranged in a tree-like hierarchical branching structure.

[0019] The tree-like hierarchical branching structure is designed according to the biomimetic fractal flow channel configuration; the cross-sectional dimensions of each level of the branch flow channel gradually decrease along the flow direction, and a preset branching angle is formed between adjacent levels of the branch flow channel. The tree-like hierarchical branching structure can reduce the pressure loss during the flow of the cooling medium and improve the uniformity of the cooling medium distribution.

[0020] The heat dissipation core 200 is made of single-crystal silicon material; the microchannel structure and the adaptive flow regulation structure 300 are formed by deep reactive ion etching process; the sealed shell 100 and the heat dissipation core 200 are sealed together by anodic bonding, eutectic bonding, low-temperature soldering, adhesive sealing or mechanical compression.

[0021] The working principle of this invention is as follows: External cooling medium enters the radiator through the liquid inlet 101 on the sealed outer shell 100, and then enters two sets of heat dissipation cores 200 disposed within the sealed outer shell 100. The two sets of heat dissipation cores 200 are arranged in a concentric parallel structure, and are offset from each other by 30° to 60° with a common center of rotation. This creates a spatially staggered layout of the microchannel structure inside the two sets of heat dissipation cores 200, thereby increasing the heat exchange path between the cooling medium and the heat dissipation cores 200 and improving the coverage of the heat dissipation area.

[0022] The cooling medium entering the heat dissipation core 200 first flows into the central inlet chamber 201, and then diffuses step by step along the primary branch channel 202, secondary branch channel 203, and tertiary branch channel 204 extending from the center outwards. This tree-like, hierarchical, branching structure allows the cooling medium to flow uniformly in multiple directions and reduces pressure loss during flow. An adaptive flow regulation structure 300 is provided at the connection area between the central inlet chamber 201 and the branch channel 202. The adaptive flow regulation structure 300 includes a fixed end 301 and a cantilevered throttling vane 302 extending from the fixed end 301. The cantilevered throttling vane 302 is composed of a first elastic vane 3021 and a second elastic vane 3022, and is integrally formed with the heat dissipation core 200 using the same material.

[0023] Under low heat load conditions, the internal temperature distribution of the heat dissipation core 200 is relatively uniform, and the thermal stress on the cantilever throttling plate 302 is small. The first elastic fin 3021 and the second elastic fin 3022 maintain their initial contact state, initially adjusting the cooling medium entering different branch channels to distribute the cooling medium to each stage of the channel according to a preset ratio. When the operating power of the semiconductor device increases and local hot spots are generated, a non-uniform temperature field is formed inside the heat dissipation core 200. Since the first elastic fin 3021 and the second elastic fin 3022 are integrally formed with the heat dissipation core 200 using the same material, temperature changes in different areas cause thermal stress to be generated inside the structure. At the same time, the cooling medium flowing through the central liquid inlet cavity 201 exerts fluid pressure on the elastic fins.

[0024] Under the combined action of thermal stress and fluid pressure, the first elastic vane 3021 and the second elastic vane 3022 elastically bend outwards, changing the flow state of the cantilever throttling vane 302 and thus altering the flow resistance relationship between different branch channels 202. As the cantilever throttling vane 302 deforms, the cooling medium automatically concentrates towards the main channel 203 corresponding to the target heat dissipation area, increasing the coolant supply to the high heat load area and achieving adaptive heat dissipation without sensors or external control systems. The cooling medium after heat exchange is collected in the liquid storage rings 400 surrounding the two sets of heat dissipation cores 200 and discharged through the liquid outlets 102 connected to both sides of the liquid storage rings 400, thus achieving a cooling cycle.

[0025] After adopting the above technical solution, the beneficial effects of the present invention are as follows: by setting two sets of concentric parallel and rotated staggered heat dissipation cores, multiple microchannel structures form a spatially interlaced heat dissipation network, which increases the contact area between the heat dissipation core and the cooling medium, extends the flow path of the cooling medium, and at the same time uses the outer liquid storage ring to realize the concentrated convergence of the cooling medium of the two cores, which improves the problems of limited heat exchange area and uneven flow distribution of traditional single-channel heat dissipation structures.

[0026] By incorporating a temperature and pressure response adaptive flow regulation structure that is homogeneous with the semiconductor substrate inside the heat dissipation core, the cantilever throttling plate can generate elastic deformation by utilizing the combined action of thermal stress and fluid pressure. It automatically adjusts the flow distribution of different branch channels according to the actual heat load changes of the device, eliminating the need for additional sensors, solenoid valves, and control circuits, thus improving the integration and response speed of the heat dissipation system.

[0027] It employs a central liquid inlet chamber and a tree-like hierarchical branching microchannel structure, enabling the cooling medium to diffuse evenly throughout the heat sink core. Simultaneously, the cantilever throttling plate features a gradient thickness structure, drag-reducing holes, and an arc-shaped stress-relieving structure, which reduces flow resistance and minimizes stress concentration at the root, improving the long-term reliability of the MEMS microstructure. The heat sink core, microchannel structure, and adaptive flow control structure are integrally formed from single-crystal silicon using deep reactive ion etching, avoiding interface failures caused by differences in thermal expansion coefficients between different materials. This makes the heat sink suitable for long-term stable heat dissipation of high-power semiconductor devices. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some specific embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a front structural diagram of the present invention;

[0030] Figure 2 yes Figure 1 Sectional view along axis AA;

[0031] Figure 3 yes Figure 1 Rear view;

[0032] Figure 4 This is a schematic diagram of the internal structure of the present invention;

[0033] Figure 5 yes Figure 4A schematic diagram of the structure after removing one set of heat sink cores 200;

[0034] Figure 6 yes Figure 5 Enlarged view of part D;

[0035] Figure 7 yes Figure 6 BB-direction sectional view;

[0036] Figure 8 yes Figure 6 A schematic diagram of the structure of the first elastic wing 3021 and the second elastic wing 3022 in the open state.

[0037] Explanation of reference numerals in the attached drawings: Sealed outer shell 100, liquid inlet port 101, liquid outlet port 102, sealed cooling cavity 103, heat dissipation core 200, central liquid inlet cavity 201, primary branch channel 202, secondary branch channel 203, tertiary branch channel 204, diversion connection area 205, adaptive flow adjustment structure 300, fixed end 301, cantilever throttling vane 302, first elastic vane 3021, second elastic vane 3022, drag reduction hole 3023, throttling vane end 303, stress relief structure 304, liquid storage ring 400. Detailed Implementation

[0038] See Figure 1-8 As shown, the technical solution adopted in this specific embodiment is as follows: it includes a heat dissipation core 200, a sealed outer shell 100, and an adaptive flow regulation structure 300 disposed inside the heat dissipation core 200.

[0039] The heat dissipation core 200 is made of single-crystal silicon material. The internal microchannel structure and the adaptive current regulation structure 300 are formed by MEMS deep reactive ion etching process, so that the heat dissipation core 200, the microchannel structure and the adaptive current regulation structure 300 are integrated into a single structure.

[0040] A sealed outer shell 100 is disposed around the heat dissipation core 200 to seal and protect the internal cooling channels. The sealed outer shell 100 is provided with a liquid inlet 101 and a liquid outlet 102, and a sealed cooling cavity is formed between the sealed outer shell 100 and the heat dissipation core 200.

[0041] In this embodiment, the sealed outer shell 100 and the heat dissipation core 200 can be connected by anodic bonding, eutectic bonding, low-temperature welding, adhesive sealing or mechanical compression to ensure stable flow of the cooling medium under high pressure.

[0042] In this embodiment, the heat dissipation core 200 is configured as two sets, and the two sets of heat dissipation cores 200 are arranged concentrically and side by side inside the sealed outer shell 100.

[0043] The two heat dissipation cores 200 are rotated 30° to 60° relative to each other using a common center as a rotation reference, and then installed in a staggered manner so that the microchannel structure inside the two heat dissipation cores 200 forms an angularly intersecting relationship.

[0044] This structure allows the corresponding areas of the two sets of heat dissipation cores 200 to form fluid heat exchange paths in different directions, thereby increasing the effective heat dissipation area per unit volume.

[0045] Each heat sink core 200 has a microchannel structure inside.

[0046] The microchannel structure includes a central inlet chamber 201, a primary branch channel 202, a secondary branch channel 203, and a tertiary branch channel 204.

[0047] The central liquid inlet chamber 201 is located in the central area of ​​the heat dissipation core 200. Multiple primary branch channels 202 extend from the central liquid inlet chamber 201 to the periphery. The secondary branch channels 203 and the tertiary branch channels 204 are further formed by the primary branch channels 202 branching out step by step.

[0048] The branch channels at each level are arranged in a tree-like hierarchical and branching structure, which allows the cooling medium to diffuse from the central area to the outer area step by step.

[0049] An adaptive flow adjustment structure 300 is provided in the connection area between the central liquid inlet chamber 201 and the branch flow channel 202.

[0050] The adaptive flow control structure 300 includes a fixed end 301 and a cantilever throttling plate 302.

[0051] The cantilever throttling vane 302 and the fixed end 301 adopt an integral structure, including a first elastic vane 3021 and a second elastic vane 3022.

[0052] The first elastic wing 3021 and the second elastic wing 3022 are located on both sides of the central liquid inlet cavity 201, and are in contact with each other in an undriven state.

[0053] The cantilever throttling plate 302 is configured with a gradient thickness structure along the direction from the fixed end 301 to the end of the throttling plate 303, wherein the thickness of the fixed end 301 region is larger to improve the connection strength; and the thickness of the end of the throttling plate 303 region is smaller to improve the response sensitivity.

[0054] Meanwhile, multiple drag-reducing holes 3023 are provided on the liquid-facing surface of the cantilever throttling plate 302 to reduce the flow resistance generated by the impact of the cooling medium.

[0055] An arc-shaped stress relief structure 304 is provided at the fixed end 301 to reduce stress concentration in the root region of the cantilever throttle plate 302.

[0056] During operation, when the radiator is in a low temperature and low load state, the first elastic fin 3021 and the second elastic fin 3022 remain in their initial state, allowing the cooling medium to enter the branch channels at each level according to a preset path.

[0057] When a local hot spot is generated, the change in temperature field causes thermal stress to be generated in the cantilever throttling plate 302. At the same time, it is subjected to the pressure of the cooling medium, causing the first elastic wing 3021 and the second elastic wing 3022 to bend outward.

[0058] The deformation of the elastic vane changes the cross-sectional area of ​​the flow channel in the corresponding region, which causes a change in the flow resistance of the cooling medium, guiding more cooling medium into the high heat load region and improving the local heat exchange efficiency.

[0059] After heat exchange is completed, the cooling medium enters the liquid storage ring 400 around the two sets of heat dissipation cores 200 and is discharged through the liquid outlet 102 connected to both sides of the liquid storage ring 400.

[0060] With the above structure, the present invention realizes a MEMS microchannel heat sink that can automatically adjust the distribution of coolant according to changes in heat load without external control.

[0061] The above description is only for illustrating the technical solution of the present invention and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A temperature and pressure responsive adaptive microchannel heat sink, characterized in that: It includes a heat dissipation core (200), a sealed outer shell (100), and an adaptive flow regulation structure (300) disposed inside the heat dissipation core (200), wherein the heat dissipation core (200) is provided with a microchannel structure. The sealed outer shell (100) covers the periphery of the heat dissipation core (200) and together with the heat dissipation core (200) forms a sealed cooling cavity. The sealed outer shell (100) is provided with a liquid inlet (101) and a liquid outlet (102) that communicate with the microchannel structure. The microchannel structure includes a central liquid inlet chamber (201) located in the central region of the heat dissipation core (200) and multiple branch channels (202) extending outward from the central liquid inlet chamber (201). The adaptive flow control structure (300) is disposed in the connection area between the central liquid inlet chamber (201) and the branch flow channel (202), and is integrally formed with the semiconductor substrate using the same material; The adaptive flow regulation structure (300) can undergo elastic deformation under the pressure of the cooling medium flowing through the microchannel structure and the thermal stress generated by the non-uniform temperature field inside the heat dissipation core (200) to change the flow area of ​​the corresponding branch flow channel (202), thereby adjusting the flow distribution of the cooling medium between different branch flow channels (202). The heat dissipation core (200) is configured in two sets. The two sets of heat dissipation cores (200) are arranged concentrically side by side and rotated and staggered relative to each other with a common center. The rotation and stagger angle is 30-60°. A through liquid storage ring (400) is provided on the outer side of the two sets of heat dissipation cores (200). The two sides of the liquid storage ring (400) are connected to the liquid outlet (102).

2. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The adaptive flow control structure (300) includes a fixed end (301) and a cantilever throttling plate (302) extending from the fixed end (301) toward the central liquid inlet chamber (201); the cantilever throttling plate (302) is located in the intersection area of ​​the central liquid inlet chamber (201) and the branch flow channel (202).

3. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The cantilever throttling vane (302) includes a first elastic vane (3021) and a second elastic vane (3022); the first elastic vane (3021) and the second elastic vane (3022) are integrally formed with the fixed end (301), and the first elastic vane (3021) and the second elastic vane (3022) are respectively disposed on both sides of the central liquid inlet cavity (201); the first elastic vane (3021) and the second elastic vane (3022) form a symmetrical suspended structure and fit together in the undriven state, and form a coolant flow gap with the corresponding branch flow channel (202) respectively.

4. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: When the first elastic wing (3021) and the second elastic wing (3022) are deformed under the combined action of temperature field and fluid pressure, the first elastic wing (3021) and the second elastic wing (3022) bend outward, increasing the force and heat dissipation area of ​​the elastic wing, thereby increasing the flow cross-sectional area of ​​the main flow channel (203) towards the target heat dissipation area, so as to guide the cooling medium to concentrate in the high heat load area.

5. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The thickness of the cantilever throttling plate (302) varies in a gradient from the fixed end (301) to the end of the throttling plate (303), and the thickness of the region near the fixed end (301) is greater than the thickness of the region near the end of the throttling plate (303) to improve the temperature and pressure response sensitivity of the cantilever throttling plate (302).

6. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The liquid-facing surface of the cantilever throttling plate (302) is provided with a plurality of drag-reducing holes (3023); the plurality of drag-reducing holes (3023) are uniformly arranged along the direction from the fixed end (301) to the end of the throttling plate (303), and the drag-reducing holes (3023) reduce the flow resistance generated when the cooling medium flows through the cantilever throttling plate (302).

7. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The fixed end (301) of the cantilever throttle plate (302) is provided with a stress relief structure (304); the stress relief structure (304) is an arc-shaped groove, and the stress relief structure (304) is used to reduce the stress concentration in the root area of ​​the cantilever throttle plate (302).

8. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The microchannel structure includes a primary branch channel (202), a secondary branch channel (203), and a tertiary branch channel (204) extending outward from the central liquid inlet chamber (201); the primary branch channel (202), the secondary branch channel (203), and the tertiary branch channel (204) are arranged in a tree-like hierarchical branching structure.

9. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The tree-like hierarchical branching structure is designed according to the biomimetic fractal flow channel configuration; the cross-sectional dimensions of each level of the branch flow channel gradually decrease along the flow direction, and a preset branching angle is formed between adjacent levels of the branch flow channel. The tree-like hierarchical branching structure can reduce the pressure loss during the flow of the cooling medium and improve the uniformity of the cooling medium distribution.

10. The temperature and pressure response adaptive microchannel heat sink according to claim 1, characterized in that: The heat dissipation core (200) is made of single-crystal silicon material; the microchannel structure and the adaptive flow regulation structure (300) are formed by deep reactive ion etching process; the sealed shell (100) and the heat dissipation core (200) are sealed together by anodic bonding, eutectic bonding, low temperature welding, adhesive sealing or mechanical pressing.

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