Micro-channel processing method and micro-channel cold plate

Abstract

The invention discloses a micro-channel processing method and a micro-channel cold plate, and the micro-channel processing method comprises the following steps: respectively processing hollow grids on the surfaces of a plurality of metal foils; the multiple metal foils with the hollowed-out grids are arranged in a stacked mode, so that meshes of the multiple metal foils communicate with one another; and metallurgically bonding the plurality of laminated metal foils, so that the meshes of the plurality of metal foils are communicated to form a micro-channel through which a cooling fluid flows. According to the micro-channel cold plate, the hollowed-out grids are machined on the multiple metal foils respectively, and then the multiple metal foils are metallurgically bonded, so that internal machining of a high-aspect-ratio and intricate micro-channel is achieved, the heat dissipation effect of the micro-channel cold plate is improved, and the heat dissipation requirement of a high-power-density chip is met.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation device technology, and in particular to a microchannel processing method and a microchannel cold plate. Background Technology

[0002] With the continuous increase in chip power density, heat dissipation has become a key factor restricting its performance, especially during chip testing, where precise temperature control is required to ensure the validity of test results. Traditional air cooling technology can no longer meet heat dissipation requirements, and liquid cooling technology has become the mainstream solution due to its high-efficiency heat dissipation capabilities. As a core component of liquid cooling systems, microchannel cold plates require internal microchannels for cooling fluid flow to achieve efficient heat dissipation. However, existing microchannel manufacturing processes, such as tooth cutting, micromilling, and micro-electrical discharge machining, are difficult to fabricate microchannels with high aspect ratios and intricate structures, thus failing to meet the heat dissipation requirements of chips. Summary of the Invention

[0003] The main objective of this invention is to provide a microchannel fabrication method to improve heat dissipation and thus meet the heat dissipation requirements of high power density chips.

[0004] To achieve the above objectives, the present invention proposes a microchannel fabrication method comprising the following steps: A perforated grid is processed on the surface of multiple metal foils; Multiple metal foils with perforated mesh are stacked together to make the mesh openings of the multiple metal foils interconnected; Multiple stacked metal foils are metallurgically bonded together to make the mesh of the multiple metal foils interconnected, forming a microchannel for the flow of cooling fluid.

[0005] Optionally, the step of "layering and arranging multiple metal foils with perforated mesh to make the mesh openings of the multiple metal foils interconnected" includes: The mesh wires of the metal foil are passed through the mesh openings of adjacent metal foils, connecting the mesh openings of two metal foils that are arranged alternately among the three adjacent metal foils, so that the mesh wires of the middle metal foil are passed between the mesh openings of the two alternately arranged metal foils.

[0006] Optionally, the step of "processing a perforated grid on the surface of multiple metal foils" includes: Multiple metal foils are processed to form horizontal and inclined mesh lines to create a perforated grid. When stacked, the horizontal mesh lines of the multiple metal foils are aligned, while the inclined mesh lines of the metal foils are inclinedly positioned between the mesh openings of two alternately stacked metal foils.

[0007] Optionally, the step of "processing horizontal and inclined mesh lines to form a hollow grid on multiple metal foils" includes: Multiple metal foils are each processed with a perforated grid with the same pattern, so that when the front and back sides of the multiple metal foils are stacked alternately, the horizontal grid lines of the multiple metal foils are aligned, and the inclined grid lines of the metal foils are inclinedly arranged between the meshes of the two metal foils that are arranged alternately.

[0008] Optionally, the step of "metallurgically bonding the stacked metal foil sheets" includes: The stacked metal foils are placed in a vacuum hot-press bonding device. The temperature of the vacuum hot-press bonding is adjusted to 400~600°C, the pressure of the vacuum hot-press bonding is adjusted to 10~50MPa, and the time of the vacuum hot-press bonding is adjusted to 10~60min.

[0009] The present invention also proposes a microchannel cold plate, comprising a manifold layer, a microchannel layer and a base plate layer, wherein the microchannel layer has microchannels formed by the above-mentioned processing method, the base plate layer is used to be close to the heating element, the microchannel layer is disposed between the manifold layer and the base plate layer, and the manifold layer has an inlet and an outlet communicating with the microchannel.

[0010] Optionally, the manifold layer includes a manifold section and a drainage section stacked together. The manifold section has the liquid inlet and the liquid outlet, and the drainage section has a drainage channel. The liquid inlet and the liquid outlet are connected to the microchannel through the drainage channel.

[0011] Optionally, the drainage section has multiple drainage channels, which are spaced apart along the length of the microchannel layer and extend along the width of the microchannel layer. Adjacent drainage channels are respectively connected to the inlet and the outlet.

[0012] Optionally, the drainage channel has two end faces facing away from each other, and the flow area of ​​the end face of the drainage channel near the manifold is larger than the flow area of ​​the end face of the drainage channel near the microchannel layer, so that the drainage channel is narrowed and the cooling fluid flowing out of the inlet is sprayed into the microchannel.

[0013] Optionally, the drainage channel includes a plurality of aligned flow channels. Along the direction from the manifold to the microchannel layer, the length of the plurality of aligned flow channels increases in an increasing trend and their width decreases, so that cooling fluid is sprayed into the microchannel along the width direction of the microchannel layer.

[0014] The technical solution of this invention involves processing perforated grids on the surfaces of multiple metal foils; stacking the metal foils with perforated grids to ensure the mesh openings of the multiple metal foils are interconnected; and metallurgically bonding the stacked metal foils to form microchannels for cooling fluid flow. This invention achieves high aspect ratio and intricate internal processing of microchannels by processing perforated grids on multiple metal foils and then metallurgically bonding them together, thereby improving the heat dissipation effect of the microchannel cold plate and meeting the heat dissipation requirements of high power density chips. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a microchannel cold plate according to an embodiment of the present invention; Figure 2 for Figure 1 Exploded view of a microchannel cold plate; Figure 3 for Figure 2 Exploded view of the middle manifold; Figure 4 for Figure 2 Exploded view of a portion of the microchannel layer; Figure 5 for Figure 2 A partial cross-sectional view of the microchannel layer; Figure 6 for Figure 5 Enlarged view of section A; Explanation of icon numbers: The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0019] In one embodiment of the present invention, a method for processing microchannels includes the following steps: processing perforated grids on the surfaces of multiple metal foils respectively; stacking multiple metal foils with perforated grids to make the mesh openings of the multiple metal foils interconnected; and metallurgically bonding the stacked multiple metal foils to make the mesh openings of the multiple metal foils interconnected to form a microchannel for cooling fluid to flow.

[0020] The technical solution of this invention involves processing perforated grids on the surfaces of multiple metal foils; stacking the metal foils with perforated grids to ensure the mesh openings of the multiple metal foils are interconnected; and metallurgically bonding the stacked metal foils to form microchannels for cooling fluid flow. This invention achieves high aspect ratio and intricate internal processing of microchannels by processing perforated grids on multiple metal foils and then metallurgically bonding them together, thereby improving the heat dissipation effect of the microchannel cold plate and meeting the heat dissipation requirements of high power density chips. This embodiment reduces the processing cost and shortens the processing cycle of microchannels while ensuring processing accuracy, thus facilitating the widespread application of microchannels.

[0021] It should be noted that the metal foil in this embodiment is made of a thermally conductive metal with good thermal conductivity. The thermally conductive metal can be copper foil, aluminum foil, or even a precious metal. Preferably, the thickness of the metal foil in this embodiment is 0.02~2mm. The metal foil can be processed into a preset perforated grid using laser cutting or chemical etching. The patterns of multiple metal foils can be adjusted according to actual conditions. Multi-layer metal foils can have the same perforated grid pattern. Multi-layer metal foils with the same pattern can form microchannels for cooling fluid flow by alternating front and back sides. Multi-layer metal foils can also have perforated grid patterns with different patterns, forming microchannels for cooling fluid flow by stacking metal foils with different patterns. Furthermore, a UV picosecond laser system with a wavelength of 385nm and a power of 15W is used for laser cutting; a photoresist mask + etching solution method is used for chemical etching. Preferably, the width and depth of the microchannels are 10-1000 μm. This embodiment can achieve the fabrication of microchannels with a depth-to-width ratio greater than 5:1, thereby increasing the heat exchange area for solid-liquid heat exchange and ensuring sufficient heat exchange between the solid and liquid, thus improving the heat dissipation effect. Of course, the number of metal foil layers can be adjusted as needed, ranging from 2 to 1000 layers. Positioning holes can be provided in the metal foils, allowing them to be stacked and ensuring the connectivity of the microchannels. This allows the cooling fluid to achieve solid-liquid heat exchange through the connectivity of the microchannels, ensuring efficient heat dissipation. The cooling fluid can be cooling water, condensate, fluorinated liquid, silicone oil, or a phase change fluid such as refrigerant or Freon, as long as it can effectively absorb heat. For the sake of clarity in explaining the technical effects of this embodiment, only coolant is used as an example of the cooling fluid. Furthermore, the multiple metal foils stacked in this embodiment can be thermo-pressed, friction-welded, or metal-welded, as long as the metallurgical bonding of the multiple metal foils can achieve the connection of the microchannels. This embodiment is not limited to this, and all of the above are within the protection scope of this embodiment.

[0022] In one embodiment of the present invention, the step of “layering and arranging a plurality of metal foils with hollowed-out meshes so that the mesh openings of the plurality of metal foils are connected” includes: passing the mesh wires of the metal foils through the mesh openings of adjacent metal foils to connect the mesh openings of two metal foils arranged alternately among three adjacent metal foils, so that the mesh wires of the middle metal foil are passed through the mesh openings of the two alternately arranged metal foils. It should be noted that in this embodiment, multiple metal foils are stacked alternately in the order of first metal foil 110, second metal foil 130, first metal foil 110, and second metal foil 130. In adjacent three metal foils, the first mesh 110a of two alternating first metal foils 110 are connected. The second metal foil 130 is the middle metal foil between the two alternating first metal foils 110. The mesh lines of the second metal foil 130 are passed through the first mesh 110a of the two first metal foils 110. In this way, when the coolant flows along the thickness direction (i.e., the Z direction) of the metal foil, this direction serves as the heat conduction direction. The mesh lines of the second metal foil 130 effectively disturb the coolant, thereby reducing the thermal resistance of the solid-liquid interface, which is conducive to sufficient solid-liquid heat exchange and further improves the heat dissipation effect on the chip.

[0023] In one embodiment of the present invention, the step of "processing a perforated grid on the surface of multiple metal foils" includes: processing horizontal and inclined mesh lines to form a perforated grid on the multiple metal foils respectively, so that when stacked, the horizontal mesh lines of the multiple metal foils are aligned and the inclined mesh lines of the metal foils are inclinedly disposed between the mesh openings of two alternately arranged metal foils. It should be noted that in this embodiment, the metal foils form a perforated grid with multiple mesh openings through horizontal and inclined mesh lines. Thus, when stacked, the horizontal mesh lines of the multiple metal foils are aligned, thereby forming a connection of mesh openings along the thickness direction of the metal foils; and the inclined mesh lines of the metal foils are inclinedly disposed between the mesh openings of two alternately arranged metal foils, thereby forming a connection of mesh openings along the length direction of the metal foils. Specifically, the second inclined mesh line 133 of the second metal foil 130 passes between the first mesh openings 110a of the two alternately arranged first metal foils 110. Thus, when the coolant flows between the first mesh openings 110a of the two alternately arranged first metal foils 110, the coolant is disturbed by the second inclined mesh line 133 and flows along the Z-direction, while simultaneously being guided by the second inclined mesh line 133 to flow along the length direction (Y-direction) of the metal foil, thereby achieving coolant flow in two different directions. Similarly, the coolant is disturbed by the first inclined mesh line 113 and flows simultaneously along both the Z and Y directions. This embodiment achieves disturbance of the coolant in different directions through the setting of inclined mesh lines, thereby enhancing solid-liquid heat exchange. Furthermore, the complex three-dimensional hollow structure formed by the horizontal mesh lines and inclined mesh lines in different directions avoids an increase in liquid flow resistance, thus ensuring effective liquid flow along the microchannel and facilitating efficient heat dissipation of the chip.

[0024] In one embodiment of the present invention, the step of “processing horizontal mesh lines and inclined mesh lines to form a hollow grid on multiple metal foils” includes: processing hollow grids with the same pattern on multiple metal foils, so that when the front and back sides of the multiple metal foils are alternately stacked, the horizontal mesh lines of the multiple metal foils are aligned and the inclined mesh lines of the metal foils are inclinedly arranged between the meshes of the two metal foils that are arranged alternately. It should be noted that in this embodiment, the first metal foil 110 and the second metal foil 130 have the same patterned perforated grid. The first metal foil 110 is positioned with its front side facing upwards, and the second metal foil 130 with its back side facing upwards. The first metal foil 110 and the second metal foil 130 are alternately stacked, i.e., first metal foil 110, second metal foil 130, first metal foil 110, second metal foil 130, ..., and so on, achieving alternating stacking of multiple metal foils. Thus, the second metal foil 130 is sandwiched between two adjacent first metal foils 110, and the second metal foil 130 is aligned... When the horizontal mesh line is aligned with the horizontal mesh line of the first metal foil 110, the second inclined mesh line 133 of the second metal foil 130 is inclinedly disposed between two adjacent first metal foils 110 connected by the first mesh 110a. This allows the second inclined mesh line 133 of the second metal foil 130 to turbulently flow the coolant as it flows between the first mesh 110a of the adjacent first metal foils 110. This enables the coolant to flow in both the thickness direction (Z direction) and length direction (Y direction) of the metal foil, thereby enhancing solid-liquid heat exchange and improving heat dissipation, thus meeting the heat dissipation requirements of high-power-density chips. In this embodiment, multiple metal foils with the same pattern are alternately stacked on their front and back sides and then metallurgically bonded to form microchannels. This simplifies the process flow while avoiding weld seams and interface thermal resistance, thereby improving heat dissipation performance.

[0025] In one embodiment of the present invention, the step of "metallurgically bonding the multiple stacked metal foils" includes: placing the multiple stacked metal foils in a vacuum hot-press bonding device, adjusting the vacuum hot-press bonding temperature to 400~600°C, adjusting the vacuum hot-press bonding pressure to 10~50MPa, and adjusting the vacuum hot-press bonding time to 10~60min. It should be noted that the parameters of the vacuum hot-press bonding device in this embodiment include temperature, pressure, and time. In this embodiment, after adjusting the temperature, pressure, and time of the vacuum hot-press bonding device, the multiple metal foils are hot-pressed and bonded. During this vacuum hot-pressing process, plastic deformation and atomic diffusion occur on the surface of the metal foils, thereby forming a metallurgical bond between the layers of metal foils, thus forming an overall microchannel structure. Specifically, the metal foil in this embodiment is copper foil. Copper foil has good corrosion resistance and can work stably for a long time in solutions such as ethylene glycol after surface treatment. In this embodiment, the vacuum hot-press bonding temperature is adjusted to 500°C, the vacuum hot-press bonding pressure to 30 MPa, and the vacuum hot-press bonding time to 30 minutes. During this process, plastic deformation and atomic diffusion occur on the surface of the copper foil, thereby forming a metallurgical bond between the copper foil layers to create microchannels. Of course, the parameters of the vacuum hot-press bonding equipment can also be adjusted according to actual conditions in this embodiment; this embodiment is not limited thereto, and all of the above are within the protection scope of this invention. This embodiment achieves a metallurgical bond between multiple metal foil sheets through hot-press bonding, ensuring that no weld seams appear between the multiple metal foil sheets, and the leakage rate is less than 10%. -6 mL / h avoids liquid leakage and the influence of interfacial thermal resistance, thereby improving the heat dissipation effect of the microchannel.

[0026] See Figures 1 to 6As shown, a microchannel layer 100 is formed with microchannels. Specifically, the microchannel layer 100 includes alternating layers of first metal foil 110 and second metal foil 130. The first metal foil 110 includes first horizontal mesh lines 111 and first inclined mesh lines 113, which form a perforated grid with multiple first mesh holes 110a. The second metal foil 130 includes second horizontal mesh lines 131 and second inclined mesh lines 133, which form a perforated grid with multiple first mesh holes 110a. The second inclined mesh line 133 forms a hollowed-out grid with multiple first mesh holes 130a. The first metal foil 110 and the second metal foil 130 have the same hollowed-out pattern. When the first metal foil 110 and the second metal foil 130 are aligned by overlapping the first horizontal mesh line 111 and the second horizontal mesh line 131, the angle between the first inclined mesh line 113 and the second inclined mesh line 133 is set so that the first horizontal mesh line 111, the first inclined mesh line 113, the second horizontal mesh line 131 and the second inclined mesh line 133 form a microchannel. Specifically, the front side of the first metal foil 110 faces upward, and the back side of the second metal foil 130 faces upward. A second inclined mesh line 133 of the second metal foil 130 is obliquely disposed in the first mesh 110a of two adjacent first metal foils 110, and a first inclined mesh line 113 of the first metal foil 110 is obliquely disposed in the second mesh 130a of two adjacent second metal foils 130. The inclination angle of the first inclined mesh line 113 relative to the first horizontal mesh line 111 is the same as the inclination angle of the second inclined mesh line 133 relative to the second horizontal mesh line 131. In this embodiment, microchannels are formed by alternating the front and back sides of multiple metal foils with the same pattern. This facilitates molding and processing, while the aligned horizontal mesh lines form the main channel for solid-liquid heat exchange. The inclined mesh lines at different angles enhance the planar strength and prevent deformation while effectively disturbing the liquid, further reducing the thermal resistance at the solid-liquid interface, thereby enhancing solid-liquid heat exchange and improving the heat dissipation effect on the chip.

[0027] See Figures 1 to 6As shown, in one embodiment of the present invention, a microchannel cold plate 1000 includes a manifold layer 300, a microchannel layer 100, and a base plate layer 500. The microchannel layer 100 has microchannels processed by the above-described method. The base plate layer 500 is used to be close to the heating element. The microchannel layer 100 is disposed between the manifold layer 300 and the base plate layer 500. The manifold layer 300 has an inlet 310a and an outlet 310b communicating with the microchannels. It should be noted that the heat source can be a chip. The base plate layer 500 is close to the chip. The base plate layer 500 is heated and continuously conducts heat to the manifold layer 300. The liquid inlet 310a and the liquid outlet 310b can be set on the same side of the manifold layer 300, or they can be set on different sides of the manifold layer 300, as long as the liquid inlet 310a and the liquid outlet 310b are respectively connected to the microfluidic layer 100. In this embodiment, the coolant flows to the microfluidic layer 100 through the liquid inlet 310a and undergoes solid-liquid heat exchange in the microfluidic layer 100. After the heat exchange, the coolant flows out from the liquid outlet 310b. This cycle repeats, achieving efficient heat dissipation for the chip. It should be noted that in this embodiment, the manifold layer 300, microchannel layer 100, and base plate layer 500 are all structural components formed of metal thermally conductive materials. The metal thermally conductive materials can be copper foil, aluminum foil, or precious metal materials, as long as heat conduction can be achieved. The manifold layer 300, microchannel layer 100, and base plate layer 500 can be thermo-pressed, friction-welded, or metal-welded, as long as a metallurgical bond can be formed between the manifold layer 300, microchannel layer 100, and base plate layer 500. This embodiment is not limited to these methods, and all of the above are within the protection scope of this embodiment. This embodiment utilizes a metal thermally conductive material to form a microchannel cold plate 1000. The thermal resistance of the formed microchannel cold plate 1000 is 0.02~0.05°C / W, which is 30~50% lower than that of traditional cold plates. This significantly reduces the thermal resistance at the solid-liquid interface, thereby enhancing solid-liquid heat exchange and improving heat dissipation. Furthermore, the microchannel cold plate 1000 can withstand water pressures exceeding 10 bar, preventing deformation after high-pressure coolant jets and ensuring stable heat dissipation. This embodiment's microchannel cold plate 1000 achieves precise temperature control of the chip through efficient heat dissipation, and has broad application potential in chip testing systems, data servers, 5G base stations, electronic control systems, and aerospace electronic equipment.

[0028] See Figures 1 to 6As shown, in one embodiment of the present invention, the manifold layer 300 includes a manifold portion 310 and a drainage portion 330 stacked together. The manifold portion 310 has an inlet 310a and an outlet 310b, and the drainage portion 330 has a drainage channel 330a. The inlet 310a and the outlet 310b are connected to the microchannel through the drainage channel 330a. It should be noted that in this embodiment, a universal joint 311 is installed on the surface of the manifold portion 310. The manifold portion 310 is installed and fixed by the universal joint 311, thereby adjusting the installation position and installation direction of the microchannel cold plate 1000. To facilitate drainage, the manifold section 310 is equipped with two manifolds to form an inlet 310a and an outlet 310b. The drainage section 330 has drainage channels 330a, which can have different shapes, such as being curved or elongated. The inlet 310a and outlet 310b can be connected to the two ends of the drainage channel 330a respectively, or the drainage section 330 can have multiple drainage channels 330a spaced apart. 30a is connected to the inlet 310a and the outlet 310b respectively. As long as the inlet 310a and the outlet 310b are connected to the microchannel through the guide channel 330a, the coolant flowing out of the inlet 310a flows to the microchannel through the guide channel 330a to form a high-pressure zone. The water in the low-pressure zone of the microchannel flows to the outlet 310b through the guide channel 330a, thereby achieving a reflux effect and continuously carrying out solid-liquid heat exchange, thus improving the heat dissipation effect on the chip.

[0029] See Figures 1 to 6As shown, in one embodiment of the present invention, the drainage section 330 has multiple drainage channels 330a, which are spaced apart along the length direction of the microchannel layer 100 and extend along the width direction of the microchannel layer 100. Adjacent drainage channels 330a are connected to the inlet 310a and the outlet 310b, respectively. It should be noted that this embodiment has drainage channels 330a extending along the width direction (X direction) of the microchannel layer 100. Thus, the coolant flowing from the inlet 310a flows through the drainage channels 330a, achieving a distribution of cooling fluid along the width direction of the microchannel layer 100. The cooling fluid distributed along the width direction (X direction) of the microchannel layer 100 flows along the length direction (Y direction) and thickness direction (Z direction) of the microchannel layer 100, thereby achieving solid-liquid heat exchange in three-dimensional space and improving the heat dissipation effect on the chip. Specifically, in this embodiment, the drainage section 330 has four drainage channels 330a, which are spaced apart along the length of the microfluidic layer 100, namely, a first drainage channel, a second drainage channel, a third drainage channel, and a fourth drainage channel. The four drainage channels 330a are alternately connected to the inlet 310a and the outlet 310b. For example, the first drainage channel is connected to the inlet 310a, the second drainage channel is connected to the outlet 310b, the third drainage channel is connected to the inlet 310a, and the fourth drainage channel is connected to the outlet 310b. With the pre-outlet 310b, the coolant flowing in from the inlet 310a flows through the first and third drainage channels 330a to the microchannels. Thus, the first and third drainage channels form a high-pressure zone, while the second and fourth drainage channels serve as low-pressure zones. The liquid flowing to the microchannels flows out through the second and fourth drainage channels 330a, thereby continuously moving the coolant from the high-pressure zone to the low-pressure zone, thus continuously carrying out solid-liquid heat exchange and achieving a highly efficient heat dissipation effect.

[0030] See Figures 1 to 6As shown, in one embodiment of the present invention, the flow channel 330a has two end faces facing each other. The flow area of ​​the end face of the flow channel 330a near the manifold portion 310 is larger than the flow area of ​​the end face of the flow channel 330a near the microchannel layer 100, so that the flow channel 330a is narrowed and the cooling fluid flowing out from the inlet 310a is sprayed into the microchannel. It should be noted that in this embodiment, the flow channel 330a can be narrowed by a gradual change, or by adjusting the length-to-width ratio of different metal sheets 331. This embodiment is not limited to this, and all of the above are within the protection scope of this embodiment. In this embodiment, by using the narrowed flow channel 330a, the coolant flowing through it is gathered and accelerated to form a concentrated jet, so that the coolant can be quickly sprayed into a deeper microchannel, thereby further reducing the solid-liquid interface thermal resistance, thereby fully carrying out solid-liquid heat exchange and further improving the heat dissipation effect on the chip.

[0031] See Figures 1 to 6 As shown, in one embodiment of the present invention, the drainage channel 330a includes a plurality of flow channels 331a arranged in alignment. Along the direction from the manifold portion 310 to the microchannel layer 100, the length of the plurality of flow channels 331a increases progressively while their width decreases, so that the cooling fluid is sprayed into the microchannel along the width direction of the microchannel layer 100. It should be noted that the drainage portion 330 in this embodiment includes a plurality of stacked metal sheets 331. Each metal sheet 331 has four flow channels 331a arranged at intervals. The plurality of flow channels 331a arranged in alignment form a drainage channel 330a. Thus, the plurality of stacked metal sheets 331 form four drainage channels 330a arranged at intervals, namely, a first drainage channel, a second drainage channel, a third drainage channel, and a fourth drainage channel. In this embodiment, by setting the length of the multiple channels 331a in an increasing trend and their width in a narrowing trend, the coolant is sprayed while ensuring that the sprayed coolant is dispersed in the hollow mesh of the microchannel layer 100 along the width direction (X direction). In this way, the coolant dispersed along the width direction of the microchannel layer 100 flows along the thickness direction (Z direction) and length direction (Y direction) of the microchannel layer 100, thereby realizing the flow of coolant in three-dimensional space, thus fully realizing solid-liquid heat exchange, ensuring uniform temperature distribution on the chip surface, and controlling the temperature difference within 5°C, which is beneficial for precise control of chip temperature.

[0032] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for fabricating microchannels, characterized in that, Includes the following steps: A perforated grid is processed on the surface of multiple metal foils; Multiple metal foils with perforated mesh are stacked together to make the mesh openings of the multiple metal foils interconnected; Multiple stacked metal foils are metallurgically bonded together to make the mesh of the multiple metal foils interconnected, forming a microchannel for the flow of cooling fluid.

2. The microchannel fabrication method as described in claim 1, characterized in that, The step of "layering multiple metal foils with perforated mesh to make the mesh openings of the multiple metal foils interconnected" includes: The mesh wires of the metal foil are passed through the mesh openings of adjacent metal foils, connecting the mesh openings of two metal foils that are arranged alternately among the three adjacent metal foils, so that the mesh wires of the middle metal foil are passed between the mesh openings of the two alternately arranged metal foils.

3. The microchannel fabrication method as described in claim 2, characterized in that, The step of "processing a perforated grid on the surface of multiple metal foils" includes: Multiple metal foils are processed to form horizontal and inclined mesh lines to create a perforated grid. When stacked, the horizontal mesh lines of the multiple metal foils are aligned, while the inclined mesh lines of the metal foils are inclinedly positioned between the mesh openings of two alternately stacked metal foils.

4. The microchannel fabrication method as described in claim 3, characterized in that, The step of "processing multiple metal foils to form horizontal and inclined mesh lines to create a hollow grid" includes: Multiple metal foils are processed with a perforated grid pattern, so that when the front and back sides of the multiple metal foils are stacked alternately, the horizontal grid lines of the multiple metal foils are aligned and the inclined grid lines of the metal foils are inclinedly arranged between the meshes of the two metal foils that are arranged alternately.

5. The method for fabricating microchannels as described in any one of claims 1 to 4, characterized in that, The step of "metallurgically bonding the stacked metal foil sheets" includes: Multiple stacked metal foils are placed in a vacuum hot-press bonding device. The temperature of the vacuum hot-press bonding is adjusted to 400~600°C, the pressure of the vacuum hot-press bonding is adjusted to 10~50MPa, and the time of the vacuum hot-press bonding is adjusted to 10~60min.

6. A microchannel cold plate, characterized in that, It includes a manifold layer, a microchannel layer, and a base plate layer. The microchannel layer has a microchannel formed by the processing method according to any one of claims 1 to 5. The base plate layer is used to be close to the heating element. The microchannel layer is disposed between the manifold layer and the base plate layer. The manifold layer has an inlet and an outlet that communicate with the microchannel.

7. The microchannel cold plate as described in claim 6, characterized in that, The manifold layer includes a manifold section and a drainage section stacked together. The manifold section has the liquid inlet and the liquid outlet, and the drainage section has a drainage channel. The liquid inlet and the liquid outlet are connected to the microchannel through the drainage channel.

8. The microchannel cold plate as described in claim 7, characterized in that, The drainage section has multiple drainage channels, which are spaced apart along the length of the microchannel layer and extend along the width of the microchannel layer. Adjacent drainage channels are respectively connected to the inlet and the outlet.

9. The microchannel cold plate as described in claim 8, characterized in that, The drainage channel has two end faces facing away from each other. The flow area of ​​the end face of the drainage channel near the manifold is larger than the flow area of ​​the end face of the drainage channel near the microchannel layer, so that the drainage channel is narrowed and the cooling fluid flowing out of the inlet is sprayed into the microchannel.

10. The microchannel cold plate as described in claim 9, characterized in that, The drainage channel includes multiple flow channels arranged in alignment. Along the direction from the manifold to the microchannel layer, the length of the multiple flow channels arranged in an increasing trend and their width arranged in a narrowing trend, so that the cooling fluid is sprayed into the microchannel along the width direction of the microchannel layer.

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