Chip heat dissipation double-hole type channel two-phase cold plate and porous structure design method

Abstract

The application discloses a double-hole channel two-phase cold plate for chip heat dissipation and a design method of a porous structure, and belongs to the technical field of heat dissipation. The double-hole channel two-phase cold plate for chip heat dissipation comprises a shell, the shell is provided with a plurality of fluid channels arranged in an array, the inner wall surface of the fluid channel comprises a porous surface, the porous surface is provided with a plurality of first porous structures and a plurality of second porous structures distributed in a dot matrix, the first porous structure is provided with a capillary liquid suction hole, the capillary liquid suction hole is configured to guide the liquid flowing through the fluid channel to flow to the inner wall surface of the fluid channel, the second porous structure is provided with a plurality of air pockets, the air pockets are configured to guide the bubbles generated by the boiling of the liquid on the inner wall surface of the fluid channel to flow in a direction away from the inner wall surface of the fluid channel, the bubbles are separated from the liquid in the bubble separation path and the liquid supplement path during phase change heat transfer, the nucleation density is increased, the distribution uniformity of the vaporization core is improved, the dryout can be effectively delayed or inhibited, and the flow stability between channels is improved.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology, and in particular to the design method of a dual-hole channel two-phase cold plate and a porous structure for chip heat dissipation. Background Technology

[0002] With the rapid development of high-power-intensive devices such as chips, the trend towards higher performance is becoming increasingly apparent, leading to greater demands for heat dissipation. As the power density and heat flux density of devices continue to rise, traditional air-cooled / liquid-cooled heat exchangers struggle to simultaneously meet the requirements of high heat transfer coefficients, temperature uniformity, and low energy consumption.

[0003] Microchannel liquid-cooled heat exchangers, due to their high specific surface area and short heat transfer path, can achieve convective heat transfer coefficients that are much higher than those of macrochannels. Introducing phase change (flow boiling) can further utilize the latent heat of vaporization to enhance the heat transfer capacity per unit flow rate.

[0004] In related technologies, the smooth fluid channels of traditional heat exchangers are prone to problems such as limited nucleation and premature drying, and flow pattern / pressure oscillations under high heat flux density. Summary of the Invention

[0005] This invention aims to at least solve the technical problems existing in related technologies. To this end, this invention proposes a dual-hole channel two-phase cold plate for chip heat dissipation, which guides the separation of the bubble detachment path and the liquid replenishment path during phase change heat transfer, increases the nucleation density and improves the uniformity of vaporization core distribution, effectively delays or inhibits drying, and improves the flow stability between channels.

[0006] This invention also proposes a design method for porous structures.

[0007] A dual-channel two-phase cold plate for chip heat dissipation according to a first aspect of the present invention includes: a housing having a plurality of fluid channels arranged in a plurality of arrangement; the inner wall surface of the fluid channels includes a porous surface; the porous surface has a plurality of first porous structures and a plurality of second porous structures distributed in a dot matrix; the first porous structures have capillary suction holes configured to guide liquid flowing through the fluid channels toward the inner wall surface of the fluid channels; the second porous structures have a plurality of air cavities configured to guide bubbles generated by the boiling of liquid on the inner wall surface of the fluid channels toward the direction away from the inner wall surface of the fluid channels.

[0008] The dual-channel two-phase cold plate for chip heat dissipation according to an embodiment of the present invention has at least the following beneficial effects: the housing has multiple fluid channels through which fluid flows, and the inner wall surface of the fluid channels includes a porous surface, the porous surface having multiple first porous structures and multiple second porous structures distributed in a lattice; wherein, the first porous structure has capillary suction holes, the capillary force generated by the capillary suction holes can transport liquid to the drying tendency area of ​​the inner wall surface of the fluid channel, thereby delaying or inhibiting drying; and the second porous structure has multiple cavitation holes, which can guide the bubbles generated by the boiling of liquid on the inner wall surface of the fluid channel to flow away from the inner wall surface of the fluid channel. This means achieving bubble detachment, thereby avoiding the formation of a vapor film on the inner wall of the fluid channel. This helps to reduce the critical nucleation superheat, increase the nucleation density, and improve the uniformity of vaporization core distribution. The dual-hole channel two-phase cold plate for chip heat dissipation can use the first porous structure as the main flow path for liquid replenishment and the second porous structure as the main flow path for gas detachment. This guides the separation of the liquid replenishment path and the bubble detachment path during phase change heat transfer, increases the nucleation density, improves the uniformity of vaporization core distribution, reduces flow pattern / pressure differences and oscillations between channels, effectively delays or inhibits drying, enhances boiling heat transfer, and improves the flow stability between channels.

[0009] According to some embodiments of the present invention, the first porous structure is provided with a plurality of capillary liquid absorption holes, and the plurality of capillary liquid absorption holes are curved channels that are directed in multiple directions.

[0010] According to some embodiments of the present invention, in a second porous structure, the plurality of cavities are multiple gas channels that are perpendicular to each other and are arranged in a continuous manner, and the direction of the continuous flow of at least one of the gas channels is perpendicular to one of the inner wall surfaces of the fluid channel.

[0011] According to some embodiments of the present invention, the first porous structure is a Gyroid-type porous structure; And / or, the second porous structure is a Schwarz-P type porous structure.

[0012] According to some embodiments of the present invention, in a porous surface, a plurality of first porous structures are interconnected to form a substrate, and a plurality of second porous structures are connected within the substrate and are distributed in a lattice.

[0013] According to some embodiments of the present invention, the cross-sectional dimensions of the fluid channel are 2mm × 2mm; And / or, the pore size of the capillary pores in the first porous structure is 0.08 mm to 0.15 mm; And / or, the pore size of the cavitation in the second porous structure is 0.1mm-0.2mm; And / or, the lattice spacing of the first porous structure and the second porous structure is 0.15mm-0.3mm; And / or, the diameter of the capillary pores is smaller than the diameter of the cavitation pores.

[0014] The design method of the second aspect of the present invention is used to fabricate a dual-hole channel two-phase cold plate for chip heat dissipation as described in any of the first aspects; the design method of the porous structure includes: Construct a TPMS triangular implicit function expression for the first porous structure and the second porous structure. The TPMS triangular implicit function expression includes the amplitude factor and morphological parameters. Construct a lattice distribution function for multiple first porous structures and multiple second porous structures, such that the first porous structures and the second porous structures are lattice-distributed; Adjust the amplitude factor and shape parameters to complete the design of the TPMS deformable surface.

[0015] According to some embodiments of the present invention, constructing a lattice distribution function for a plurality of first porous structures and a plurality of second porous structures includes: Multiple first porous structures are interconnected to form a substrate, and multiple second porous structures are distributed within the substrate according to a lattice distribution function; with the length direction of the fluid channel as the X direction and the width or thickness direction of the fluid channel as the Y direction, the external dimension of the second porous structure is d, and the center distance between two adjacent second porous structures is a, then the center coordinates of the (i,j)th second porous structure are: ; ; in, and Let n be the starting coordinate, and m be the number of second porous structures in the x and y directions, respectively. n = [(Ld) / a], where L is the length of the fluid channel, m = [(Sd) / a], and S is the width or thickness of the fluid channel.

[0016] According to some embodiments of the present invention, the design method of porous structures further includes: The deformable surface is offset by a preset distance along the two normal surfaces to obtain two offset surfaces; By solidifying the space between two offset surfaces, a porous surface with a first porous structure and a second porous structure is obtained.

[0017] According to some embodiments of the present invention, the design method of porous structures further includes: A 3D model of a heat exchanger with fluid channels is constructed. The inner wall of the fluid channels includes a porous surface with multiple first porous structures and multiple second porous structures, and the multiple first porous structures and multiple second porous structures are distributed in a lattice. The 3D model of the heat exchanger is sliced ​​into multiple 2D slices, and then the multiple 2D slices are stacked together using metal 3D printing technology to obtain the solid heat exchanger.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of a dual-hole channel two-phase cold plate for chip heat dissipation according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the first and second porous structures of a multi-hole channel two-phase cold plate for chip heat dissipation according to an embodiment of the present invention, in which the porous surface is distributed in a lattice. Figure 3 This is a schematic diagram of the first porous structure of a dual-channel two-phase cold plate for chip heat dissipation according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the second porous structure of a dual-channel two-phase cold plate for chip heat dissipation according to an embodiment of the present invention. Figure 5 This is a flowchart illustrating a design method for a porous structure according to an embodiment of the present invention; Figure 6 This is a flowchart illustrating the solidification of deformable surfaces in a design method for porous structures according to an embodiment of the present invention. Figure 7 This is a flowchart illustrating the 3D printing process of a porous structure design method according to an embodiment of the present invention.

[0020] Icon labels: 100. Shell; 110. Fluid passage; 111. Inlet end; 112. Outlet end; 200. Porous surface; 210. First porous structure; 211. Capillary pores; 220. Second porous structure; 221. Cavitation. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0024] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0025] With the rapid development of the chip industry, the power density and heat flux density of high-power devices such as chips continue to rise (chip > Traditional air-cooled / liquid-cooled heat exchangers struggle to simultaneously meet the demands for high heat transfer coefficients, temperature uniformity, and low energy consumption. High-power devices such as semiconductors present the following common heat dissipation requirements: 1. Achieve high heat dissipation and low thermal resistance within a limited volume.

[0026] 2. Suppress hot spots and temperature unevenness to improve device stability and lifespan.

[0027] 3. Low pump power / low pressure drop, resulting in high system energy efficiency.

[0028] 4. It can be mass-produced and integrated with chips / modules with high reliability.

[0029] Microchannel liquid-cooled heat exchangers, due to their high specific surface area and short heat transfer path, can achieve convective heat transfer coefficients far exceeding those of macrochannels. Introducing phase change (flow boiling) can further utilize the latent heat of vaporization to enhance the heat transfer capacity per unit flow rate. However, the smooth microchannels of traditional heat exchangers are prone to problems under high heat flux densities, such as limited nucleation and premature drying, flow pattern / pressure oscillations, local temperature peaks and drastic fluctuations, and a sharp increase in two-phase frictional pressure drop. It is difficult to achieve a balance between "high heat transfer, low fluctuations, low pressure drop, and high uniform temperature".

[0030] Related technologies propose a method for preparing a multilayer metal capillary core. By applying a pre-coating to the inner wall of a dense metal tube, the bonding force between the capillary layer and the outer metal tube is enhanced, and its axial shrinkage is slowed down, naturally forming a steam flow channel in the axial direction. However, it still has at least the following drawbacks: (1) Deterioration of flow distribution (parallel microchannels): The coatings of different channels have different thicknesses / pores, resulting in uneven branch resistance, which leads to uneven heat load and "thermal mismatch" between channels.

[0031] (2) Local drying occurs prematurely: small holes enhance nucleation but also easily form vapor cover; if the coating is thick / the pores are poorly connected, the liquid replenishment is not timely, which leads to limited CHF increase or even decrease.

[0032] (3) Risk of peeling / powdering: Thermal cycling, thermal shock, and fluid scouring can cause stress concentration at the interface between the coating and the substrate, which can lead to coating adhesion failure and powdering.

[0033] (4) Thickness / pore size is difficult to control precisely: poor uniformity of deposition on the inner wall of the channel (port effect / masking effect), and deviation of parameters between the two side walls and the bottom wall leads to large batch / sheet dispersion and high verification cost.

[0034] (5) Manufacturing consistency and repeatability: When preparing large-area batches, it is difficult to control the pore size distribution, porosity gradient and layer thickness. The process fluctuations of interface thermal resistance and mechanical strength affect performance and lifespan.

[0035] Reference Figures 1 to 7 As shown, a dual-hole channel two-phase cold plate for chip heat dissipation in one embodiment of the present invention achieves effective control of phase change heat transfer performance through the design of a dual-hole multi-hole structure.

[0036] Reference Figure 1 and Figure 2 As shown, specifically, the housing 100 has a plurality of fluid channels 110 arranged in a row. Each fluid channel 110 has an inlet end 111 and an outlet end 112. That is, fluid can enter the fluid channel 110 from the inlet end 111 and flow out from the outlet end 112. The inner wall surface of the fluid channel 110 includes a porous surface 200. That is, the porous surface 200 is at least a part of the inner wall surface of the fluid channel 110. The porous surface 200 can serve as the side wall or bottom wall of the fluid channel 110. When the fluid passes through the fluid channel 110, the porous surface 200 can contact the fluid.

[0037] Reference Figure 2 , Figure 3 and Figure 4 As shown, specifically, the porous surface 200 has a plurality of first porous structures 210 and a plurality of second porous structures 220 distributed in a lattice. The first porous structure 210 has capillary liquid absorption holes 211, which are configured to guide the liquid flowing through the fluid channel 110 to flow to the inner wall surface of the fluid channel 110, that is, to transport the liquid to the drying tendency area of ​​the inner wall surface of the fluid channel 110, thereby delaying or inhibiting drying. Figure 2In the diagram, the white square represents a first porous structure 210, and the black square represents a second porous structure 220.

[0038] Reference Figure 2 , Figure 3 and Figure 4 As shown, the second porous structure 220 has multiple air cavities 221. The air cavities 221 can guide the bubbles generated by the boiling of liquid on the inner wall of the fluid channel 110 to flow away from the inner wall of the fluid channel 110, thereby avoiding the problem of vapor film formation on the inner wall of the fluid channel 110. This is beneficial to reduce the critical nucleation superheat, increase the nucleation density, and enhance the heat transfer in the early stage of boiling.

[0039] Reference Figure 2 , Figure 3 and Figure 4 As shown in the embodiment of this application, the dual-hole channel two-phase cold plate for chip heat dissipation introduces a porous surface 200 on the wall of the fluid channel 110. The micro-nano pores of the porous surface 200 provide a capillary return liquid and gas-liquid phase separation interface, which is beneficial to improving the two-phase heat transfer and system stability within the fluid channel 110. Specifically, the dual-hole channel two-phase cold plate for chip heat dissipation uses a first porous structure 210 as the main flow path for liquid replenishment and a second porous structure 220 as the main flow path for gas removal. This guides the separation of the liquid replenishment path and the bubble removal path during phase change heat transfer, increases the nucleation density and improves the uniformity of vaporization nucleus distribution, reduces flow pattern / pressure differences and oscillations between channels, effectively delays or suppresses drying, enhances boiling heat transfer, and improves the flow stability between channels.

[0040] Reference Figure 2 , Figure 3 and Figure 4 As shown, it is understandable that traditional heat exchangers suffer from the defect of excessive and rapid generation of steam bubbles on the heated wall, which merge together to form a steam film that isolates the liquid from the heated wall. Due to the presence of this steam film, the liquid can no longer contact the heated wall. Without the cooling effect of the liquid, the wall temperature rises sharply, resulting in premature drying.

[0041] Reference Figure 2 , Figure 3 and Figure 4 As shown, specifically, the first porous structure 210 of the dual-hole channel two-phase cold plate for chip heat dissipation has multiple capillary liquid absorption holes 211. The multiple capillary liquid absorption holes 211 are curved channels that open in multiple directions, which facilitates the penetration of liquid into the inner wall surface of the fluid channel 110 from various directions, prevents the inner wall surface of the fluid channel 110 from drying out, and improves the heat dissipation efficiency of the dual-hole channel two-phase cold plate for chip heat dissipation.

[0042] Reference Figure 2 , Figure 3 and Figure 4 As shown, specifically, in the second porous structure 220 of the dual-channel two-phase cold plate for chip heat dissipation, multiple air cavities 221 are multiple mutually perpendicular gas channels, which are arranged in a continuous manner. At least one of the gas channels is perpendicular to one of the inner wall surfaces of the fluid channel 110 in the length direction, which is conducive to the detachment of nucleated bubbles, thereby accelerating the detachment of bubbles and avoiding the problem of vapor film formation on the inner wall surface of the fluid channel 110. This improves the phase change heat transfer efficiency and reduces the risk of nucleation restriction and premature drying.

[0043] Reference Figure 2 , Figure 3 and Figure 4 As shown, it can be understood that the first porous structure 210 is a Gyroid-type porous structure and the second porous structure 220 is a Schwarz-P-type porous structure.

[0044] Reference Figure 2 , Figure 3 and Figure 4 As shown, the Triple Periodic Minimal Surface (TPMS) was first proposed by the German mathematician Hermann Schwarz in 1865. The TPMS structure has an average curvature of 0, a continuous and smooth surface, and a large specific surface area; simultaneously, its internal structure is interconnected in multiple directions, exhibiting strong permeability. Therefore, applying the TPMS structure to microchannel flow boiling research can not only provide a larger heat transfer area but also regulate the permeability of the gas and liquid phases by changing the pore size, promoting the detachment of nucleated bubbles and the wetting of the surface by the liquid, enhancing the orderliness of the gas-liquid two-phase behavior. This allows the dual-pore channel two-phase cold plate used for chip heat dissipation to achieve high-throughput heat dissipation and low thermal resistance within a limited volume.

[0045] Reference Figure 2 , Figure 3 and Figure 4 As shown, according to the analysis of permeability theory, the permeability of liquids is significantly affected by pore connectivity and viscosity, while the permeability of gases is more sensitive to pore size.

[0046] Reference Figure 2 , Figure 3 and Figure 4As shown, considering the different behavior characteristics of the gas and liquid phases during nucleation boiling in microchannels, the dual-channel two-phase cold plate for chip heat dissipation employs a Gyroid-type porous structure as the main flow path for liquid replenishment and a Schwarz-P type pore as the main flow path for gas removal. The Gyroid-type pore structure has tortuous channels in multiple directions, which facilitates liquid penetration into the inner wall of the fluid channel 110 from various directions, preventing the surface of the inner wall of the fluid channel 110 from drying out. The Schwarz-P type porous structure has three mutually perpendicular straight-through channels, which facilitates the removal of nucleated bubbles and improves the phase change heat transfer efficiency.

[0047] Reference Figure 2 , Figure 3 and Figure 4 As shown, it is understandable that in boiling microfluidics, the random generation and growth of bubbles can lead to violent fluctuations in local pressure, causing flow pattern oscillations and flow reversals, which severely interfere with the liquid supply and bubble detachment process, resulting in unstable heat transfer and temperature fluctuations.

[0048] In the chip heat dissipation dual-channel two-phase cold plate provided in this embodiment of the invention, multiple first porous structures 210 are interconnected in the porous surface 200 to form a substrate, and multiple second porous structures 220 are connected in the substrate and distributed in a dot matrix. The multiple first porous structures 210 and the multiple second porous structures 220 are interconnected.

[0049] Reference Figure 2 , Figure 3 and Figure 4 As shown, multiple first porous structures 210 form a near-wall layer, while multiple second porous structures 220 form a core layer. The near-wall layer is arranged around the core layer. The near-wall layer is biased towards liquid phase permeation and replenishment, while the core layer facilitates the discharge of the main vapor stream, thereby reducing interface competition and improving heat transfer stability.

[0050] Reference Figure 2 , Figure 3 and Figure 4 As shown, the first porous structure 210 and the second porous structure 220 are constructed and jointly form a "parallel heat conduction network" within the porous surface 200, which diffuses the heat from hot spots, reduces the temperature standard deviation, suppresses hot spots and temperature unevenness, and improves the stability and lifespan of the device.

[0051] Reference Figure 2 , Figure 3 and Figure 4 As shown, the dual-hole channel two-phase cold plate for chip heat dissipation can adjust the density and distribution uniformity of the vaporization core by changing the size parameters and lattice distribution parameters of the first porous structure 210 and the second porous structure 220, thereby improving the uniformity of the phase change gas content between channels.

[0052] Reference Figure 2 , Figure 3 and Figure 4 As shown, it can be understood that the cross-sectional dimensions of the fluid channel 110 are 2mm × 2mm; the pore diameter of the capillary suction pores 211 of the first porous structure 210 is 0.08mm-0.15mm; the pore diameter of the cavitation cavities 221 of the second porous structure 220 is 0.1mm-0.2mm; and the lattice distribution spacing between the first porous structure 210 and the second porous structure 220 is 0.015mm-0.3mm. The pore diameter of the capillary suction pores 211 is smaller than the pore diameter of the cavitation cavities 221.

[0053] Reference Figure 2 , Figure 3 and Figure 4 As shown, specifically, the dual-hole channel two-phase cold plate for heat dissipation of the chip can be formed by metal 3D printing (such as electrochemical 3D printing) to form the structure of shell 100 and porous surface 200, so as to complete the precise and efficient design of complex dual-hole porous structure and realize the regulation of phase change heat transfer performance by dual-hole porous structure.

[0054] Reference Figure 2 , Figure 3 and Figure 4 As shown, the dual-hole channel two-phase cold plate for chip heat dissipation is designed based on the parameter-driven design of TPMS (triple periodic minimum surface) trigonometric functions. By changing the amplitude factor and morphological parameters in the TPMS trigonometric function parameter expression, the design of the TPMS deformable hole unit is completed, realizing the geometric shape change of the porous structure.

[0055] Reference Figure 2 , Figure 3 and Figure 4 As shown, the dual-channel two-phase cold plate for heat dissipation of the chip can be constructed by electrochemical 3D printing on the fluid channel 110 to build a porous surface 200. The three-dimensional model data is imported into the 3D printing equipment, and the fine fluid channels 110 with different porous surfaces 200 are printed according to the model surface data description, thereby obtaining the heat exchanger.

[0056] Reference Figures 5-7 As shown, the present invention provides a method for designing a porous structure, used for designing and manufacturing a dual-hole channel two-phase cold plate for chip heat dissipation as shown in any of the above embodiments. The method for designing the porous structure includes the following steps: Step S100: Construct TPMS triangular implicit function expressions for the first porous structure 210 and the second porous structure 220. The TPMS triangular implicit function expressions include amplitude factors and morphological parameters. Step S200: Construct a lattice distribution function for the plurality of first porous structures 210 and the plurality of second porous structures 220, so that the first porous structures 210 and the second porous structures 220 are lattice distributed. Step S300: Adjust the amplitude factor and shape parameters to complete the design of the TPMS deformable surface.

[0057] Reference Figure 2 and Figure 5 As shown, in step S100, specifically, the first porous structure 210 is a Gyroid-type porous structure, while the second porous structure 220 is a Schwarz-P-type porous structure. The TPMS structure, applied to microchannel flow boiling research, not only provides a larger heat transfer area but also allows for the regulation of gas and liquid phase permeability by altering pore size, promoting the detachment of nucleated bubbles, liquid wetting of surfaces, and enhancing the orderliness of the gas-liquid two-phase behavior.

[0058] Reference Figure 2 and Figure 5 As shown, the shape of the TPMS structure is strictly controlled by implicit functional equations containing trigonometric functions. The governing equations for the Gyroid-type and Schwarz-P-type pore structures are as follows: ; ; Reference Figure 2 and Figure 5 As shown, in the above implicit function equation, d, e, f, g, h, and i are all amplitude factors, while t is a morphological parameter.

[0059] Reference Figure 2 and Figure 5 As shown, the first porous structure 210 is a Gyroid-type porous structure that facilitates liquid permeation and flow. The second porous structure 220, which is a Schwarz-P type porous structure, facilitates bubble detachment by lattice distribution. This separates the bubble detachment path and the liquid replenishment path during phase change heat transfer, thereby simultaneously meeting the requirements of different behavior characteristics of the vapor and liquid phases during phase change on the channel surface. This achieves precise control and phase change-enhanced heat transfer effect of the micro-channel dual-pore porous structure.

[0060] In step S200, the porous structure design method can construct a lattice distribution function of multiple first porous structures 210 and multiple second porous structures 220 so that the multiple first porous structures 210 and multiple second porous structures 220 are lattice distributed.

[0061] Reference Figure 2 and Figure 5As shown, in step S300, the porous structure design method proposes a mathematical function based on the Triply Periodic Minimal Surface (TPMS) to drive the design of the dual-hole channel two-phase cold plate for chip heat dissipation mentioned in the above embodiment. By adjusting the amplitude factor and morphological parameters, it is possible to accurately and efficiently construct pore structures of different shapes and sizes in the first porous structure 210 and the second porous structure 220, construct the quantitative relationship between the porous structure characteristics and the TPMS function expression, and obtain the influence law of the TPMS-based Gyroid type and Schwarz-P type pore structures on the liquid permeation process.

[0062] Reference Figure 2 and Figure 5 As shown, the TPMS structure has the characteristics of suitable pore size, large specific surface area, high permeability and smooth flow channel. The design method of this porous structure can control the geometric morphological characteristics of the first porous structure 210 and the second porous structure 220 by adjusting the amplitude factor and morphological parameters. Through the design of the dual-pore porous structure, the phase change heat transfer performance can be effectively controlled.

[0063] Understandably, the porous structure design method, in step S200, constructing the lattice distribution function for the plurality of first porous structures 210 and the plurality of second porous structures 220 includes the following steps: Multiple first porous structures 210 are interconnected to form a substrate, and multiple second porous structures 220 are distributed within the substrate according to a lattice distribution function; taking the length direction of the fluid channel 110 as the X direction, the width direction or thickness direction of the fluid channel 110 as the Y direction, the external dimension of the second porous structure 220 as d, and the center distance between two adjacent second porous structures 220 as a, then the center coordinates of the (i,j)th second porous structure 220 are: ; ; in, and Let n be the starting coordinate, and m be the number of second porous structures 220 in the x and y directions, respectively. n = [(Ld) / a], where L is the length of the fluid channel 110, and m = [(Sd) / a], where S is the width or thickness of the fluid channel 110.

[0064] The lattice distribution of the first porous structure 210 and the second porous structure 220 has the following advantages: (1) Precise control of flow path: The "lattice" ensures the regular arrangement of the first porous structure 210 and the second porous structure 220, and the path through which the fluid passes can be preset to construct the liquid replenishment channel and the gas detachment channel.

[0065] (2) Improve the uniformity of vaporization core distribution: The second porous structure 220 with a larger pore size is more likely to be activated into vaporization core, while the lattice distribution can improve the uniformity of vaporization core distribution in the channel and reduce the flow pattern / pressure difference between channels.

[0066] (3) Increase surface area: Ordinary porous structures (such as particle sintered porous metals) have uneven pore distribution and a large number of closed pores or blind pores. However, the "lattice distribution" combined with the characteristics of "TPMS dual pores" can create a higher specific surface area within a given volume or surface area. A larger surface area usually means more efficient heat transfer or mass transfer.

[0067] (4) Avoid dead zones and blockages: The continuous and interconnected pores of the TPMS structure combined with the regular lattice distribution can prevent fluid from stagnating in certain areas and forming dead zones, or from excessive accumulation in certain areas leading to blockages.

[0068] (5) Based on regularity, it increases the flexibility of design and adaptability to complex geometry, and can optimize heat transfer, mass transfer, fluid dynamics and other performance by precisely controlling pore structure parameters and lattice distribution parameters.

[0069] Reference Figure 2 and Figure 6 As shown, it is understandable that the design method for porous structures also includes the following steps: Step S400: Offset the deformed surface along the two normal surfaces by a preset distance to obtain two offset surfaces; In step S500, the space between the two offset surfaces is solidified to obtain a porous surface 200 with a first porous structure 210 and a second porous structure 220.

[0070] Reference Figure 3 , Figure 4 and Figure 6 As shown, in steps S400 and S500, after the TPMS deformable surface design is completed by the dual-hole channel two-phase cold plate for chip heat dissipation, the obtained deformable surface can be offset by a preset distance along the two normal surfaces to obtain two offset surfaces. By solidifying the space between the two offset surfaces, the construction of the first porous structure 210 and the second porous structure 220 can be completed, so that the porous surface 200 has two porous structures: the first porous structure 210 and the second porous structure 220.

[0071] Reference Figure 3 , Figure 4 and Figure 6 As shown, it should be noted that the spatial solidification between the two offset surfaces can be achieved using the nTopology software. The preset distance can be adjusted according to actual design requirements, which will not be elaborated here.

[0072] Reference Figure 1 , Figure 2 and Figure 7 As shown, it is understandable that the design method for porous structures also includes the following steps: Step S600: Construct a 3D model of a heat exchanger with a fluid channel 110. The inner wall of the fluid channel 110 includes a porous surface 200. The porous surface 200 has multiple first porous structures 210 and multiple second porous structures 220, and the multiple first porous structures 210 and multiple second porous structures 220 are distributed in a lattice. Step S700: The heat exchanger 3D model is sliced ​​into multiple 2D slices, and the multiple 2D slices are stacked solid using metal 3D printing technology to obtain the heat exchanger solid.

[0073] Reference Figure 1 , Figure 2 and Figure 7 As shown, the porous structure design method can construct a heat exchanger 3D model containing the first porous structure 210 and the second porous structure 220 based on the obtained first porous structure 210 and second porous structure 220. The heat exchanger 3D model is sliced ​​into several layers of 2D slices by 3D printing (additive manufacturing). The raw materials are directly and precisely prepared layer by layer by using electrochemical 3D printing technology to obtain the heat exchanger entity.

[0074] Reference Figure 1 , Figure 2 and Figure 7 As shown, the design method for this porous structure demonstrates through preliminary experiments that the designed TPMS-based Schwarz-P type porous structure can be precisely formed using metal 3D printing technology. In the simulation experiment, the pore surface of the Schwarz-P type porous structure exhibits semi-molten powder, increasing the surface area and enhancing convective heat transfer. Furthermore, the pore edges of the Schwarz-P type porous structure show slight spheroidization. Currently, the porous structure design method is implemented using electrochemical 3D printing technology. The processing precision of electrochemical 3D printing can typically reach the micrometer or even submicrometer level. Subsequent parameter optimization can further enable the precise manufacturing and control of dual-channel two-phase cold plates for chip heat dissipation. Therefore, this porous structure design method is feasible for the integrated and precise manufacturing of dual-channel two-phase cold plates for chip heat dissipation.

[0075] It should be understood that, in some other embodiments, this porous structure design method can also manufacture dual-channel two-phase cold plates for chip heat dissipation through selective laser melting, laser / electron beam energy deposition, etc.

[0076] Reference Figure 1 , Figure 2 and Figure 7As shown, it can be understood that in this embodiment, the design method of the porous structure changes the size and distribution parameters of the Schwarz-P type and Gyroid type pores to meet the differentiated requirements of the gas-liquid two-phase dynamics behavior involved in bubble nucleation and two-phase flow between channels on the capillary permeability performance of the porous medium, thereby achieving the regulation of two-phase behavior.

[0077] According to Hsu's activated cavity theory, the size range within which surface pores can serve as activated nuclei is: ; Where δ is the thermal boundary layer thickness, T_w is the wall temperature, T_s is the saturation temperature, T_∞ is the mainstream liquid temperature, C_1 and C_2 are empirical constants, σ ​​is the liquid surface tension, h_f is the latent heat of vaporization of the liquid, and p_v is the saturated vapor density.

[0078] As shown in the above equation, under given conditions, only pores within a certain size range can be activated to become vaporization nuclei. Furthermore, within the activation conditions, the larger the pore size, the lower the wall superheat required for bubble growth. Therefore, the design method of this porous structure, which precisely modifies the pore structure and size to control the vaporization nuclei, is feasible.

[0079] In addition, the Schwarz-P type pores have an inward expansion characteristic, which can reduce the cooling effect of external supercooled fluid on the gas nuclei, protect the growth of bubbles, and thus facilitate nucleation.

[0080] According to Young-Laplace capillary theory, the capillary pressure of porous materials is: ; Where ΔP is the capillary pressure generated by the porous material, σ is the surface tension of the liquid, θ is the contact angle of the liquid on the solid surface, and d_p is the characteristic pore size of the porous material.

[0081] As can be seen from the above, capillary pressure is inversely proportional to pore size. That is, the smaller the pore size, the greater the capillary pressure, which is more conducive to the absorption of liquid by porous materials, thereby maintaining surface wettability.

[0082] According to Darcy's Law, the flow resistance of a liquid in a porous material is: ; Where ΔP_vis is the viscous pressure drop (flow resistance), μ is the dynamic viscosity of the liquid, δ is the thickness of the porous medium in the flow direction, L is the actual flow path length of the liquid in the pores, v is the apparent flow velocity of the liquid, C_v is a dimensionless constant (shape factor) related to the pore tortuosity and shape, ε is the porosity of the porous medium, and d_p is the characteristic pore size (or particle diameter) of the porous material.

[0083] As can be seen from the above formula, the resistance to liquid flow is inversely proportional to the square of the orifice diameter, which means that the smaller the orifice diameter, the less favorable it is for fluid flow.

[0084] It is evident that the capillary action and permeation of porous media on liquids are mutually influential, and it is necessary to find the balance point of capillary permeation. This is also the significance of the design method of this porous structure, which controls the density and distribution uniformity of vaporization nuclei by changing the amplitude factor and morphological parameters.

[0085] Similarly, Darcy's law can be used to obtain the mass flow rate of gas passing through a porous medium: ; Where m is the gas mass flow rate through the porous medium, ρ_v is the gas (vapor) density, σ is the liquid surface tension, μ_v is the dynamic viscosity of the gas (vapor), ε is the porosity of the porous medium, d_p is the characteristic pore size of the porous material, and δ is the thickness of the porous medium (the length through which the gas flows).

[0086] As shown in the above equation, the gas escape mass flow rate is directly proportional to the cube of the pore size, meaning that a larger pore size in the porous medium is more conducive to gas escape. Furthermore, the capillary effect on the liquid is also considered under high gas content conditions, providing a theoretical basis for the control research of dual-channel two-phase cold plates for chip heat dissipation.

[0087] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A dual-hole channel two-phase cold plate for chip heat dissipation, characterized in that, include: The housing has a plurality of fluid channels arranged in an array. The inner wall surface of the fluid channels includes a porous surface. The porous surface has a plurality of first porous structures and a plurality of second porous structures distributed in a lattice. The first porous structures have capillary pores configured to guide the liquid flowing through the fluid channels toward the inner wall surface of the fluid channels. The second porous structures have a plurality of cavitation cavities configured to guide the bubbles generated by the boiling of the liquid on the inner wall surface of the fluid channels to flow away from the inner wall surface of the fluid channels. The first porous structure is a Gyroid-type porous structure; the second porous structure is a Schwarz-P-type porous structure.

2. The dual-hole channel two-phase cold plate for chip heat dissipation according to claim 1, characterized in that, The first porous structure is provided with a plurality of capillary liquid absorption holes, and the plurality of capillary liquid absorption holes are curved channels that open in multiple directions.

3. The dual-hole channel two-phase cold plate for chip heat dissipation according to claim 1, characterized in that, In one of the second porous structures, the plurality of air cavities are multiple gas channels that are perpendicular to each other and are arranged in a continuous manner, and the direction of the continuous flow of at least one of the gas channels is perpendicular to one of the inner wall surfaces of the fluid channel.

4. The dual-hole channel two-phase cold plate for chip heat dissipation according to claim 1, characterized in that, In the porous surface, a plurality of first porous structures are interconnected to form a substrate, and a plurality of second porous structures are connected within the substrate and are distributed in a lattice pattern.

5. The dual-hole channel two-phase cold plate for chip heat dissipation according to claim 1, characterized in that, The cross-sectional dimensions of the fluid channel are 2mm × 2mm; And / or, the pore size of the capillary pores in the first porous structure is 0.08 mm to 0.15 mm; And / or, the pore size of the cavitation in the second porous structure is 0.1mm-0.2mm; And / or, the lattice spacing of the first porous structure and the second porous structure is 0.15mm-0.3mm; And / or, the diameter of the capillary pore is smaller than the diameter of the cavitation.

6. A design method for a porous structure, characterized in that, A method for fabricating a dual-hole channel two-phase cold plate for chip heat dissipation as described in any one of claims 1 to 5; the design method of the porous structure includes: Construct a TPMS triangular implicit function expression for the first porous structure and the second porous structure, wherein the TPMS triangular implicit function expression includes an amplitude factor and a morphological parameter; Construct a lattice distribution function for multiple first porous structures and multiple second porous structures, such that the first porous structures and the second porous structures are lattice-distributed; Adjust the amplitude factor and the shape parameters to complete the design of the TPMS deformable surface.

7. The design method for porous structures according to claim 6, characterized in that, The construction of the lattice distribution function for the plurality of first porous structures and the plurality of second porous structures includes: Multiple first porous structures are interconnected to form a substrate, and multiple second porous structures are distributed within the substrate according to the lattice distribution function; taking the length direction of the fluid channel as the X direction, the width direction or thickness direction of the fluid channel as the Y direction, the external dimension of the second porous structure as d, and the center distance between two adjacent second porous structures as a, then the center coordinates of the (i,j)th second porous structure are: ； ； in, and Let n be the starting coordinate, and m be the number of the second porous structures in the x and y directions, respectively. n = [(Ld) / a], where L is the length of the fluid channel, m = [(Sd) / a], and S is the width or thickness of the fluid channel.

8. The design method for porous structures according to claim 7, characterized in that, The design method for the porous structure also includes: The deformed surface is offset by a preset distance along the two normal surfaces to obtain two offset surfaces; By solidifying the space between the two offset surfaces, a porous surface having the first porous structure and the second porous structure is obtained.

9. The design method for porous structures according to claim 8, characterized in that, The design method for the porous structure also includes: A 3D model of a heat exchanger with a fluid channel is constructed. The inner wall surface of the fluid channel includes the porous surface. The porous surface has multiple first porous structures and multiple second porous structures, and the multiple first porous structures and multiple second porous structures are distributed in a lattice. The heat exchanger 3D model is sliced ​​into multiple 2D slices, and the multiple 2D slices are stacked together using metal 3D printing technology to obtain the heat exchanger solid.

Images