A method for preparing a high thermal conductivity circuit board by pressing and a high thermal conductivity circuit board

Abstract

The present application discloses a method for laminating and preparing a high thermal conductivity circuit board and a high thermal conductivity circuit board. The preparation method comprises: dispersing and curing a liquid metal gallium-indium alloy and a fiber mixture in an inert argon atmosphere, and fusing the mixture with a matrix to obtain an adaptive thermal conductive substrate; performing gradient deposition and etching on the adaptive thermal conductive substrate to obtain a gradient spacing template; performing electrospinning infiltration and heat treatment on the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network; performing a conductive layer pre-pressing treatment on the substrate containing the dynamic thermal conductive network to obtain a pre-assembled plate; performing a staged dynamic lamination treatment on the pre-assembled plate to obtain a molded circuit board; and performing surface spraying and deposition treatment on the molded circuit board to obtain the high thermal conductivity circuit board. The present application solves the problems of poor heat flow path and poor interface bonding in the prior art, significantly improving the thermal management effect and significantly improving the reliability and performance of electronic products.

Description

Technical Field

[0001] The present application relates to the technical field of circuit board preparation, and in particular to a method for pressing and preparing a high thermal conductivity circuit board and a high thermal conductivity circuit board. Background Art

[0002] With the increasing power density of electronic devices, especially in high-power electronic devices and integrated circuits, good thermal conductivity has become a key requirement for electronic packaging materials. Existing circuit board materials mostly use copper foil and epoxy resin composites, but due to their low thermal conductivity, these materials have significant heat accumulation problems in high-power electronic devices.

[0003] In existing technologies, the common method for improving thermal conductivity is to introduce highly conductive fillers, such as aluminum nitride (AlN), metallized carbon nanotubes, and graphene. However, these technologies mostly focus on the thermal conductivity of the material itself, ignoring the impact of the overall circuit board structure on heat flow. Furthermore, during the lamination process, the filler's uniform dispersion and interfacial bonding are poor, resulting in the inability to fully realize the thermal conductivity effect in practical applications. Even when modified fillers or composite materials are used, the conventional lamination process in existing technologies cannot effectively address the issues of heat flow path optimization and thermal interface effects.

[0004] Therefore, how to further improve the thermal conductivity of circuit boards while maintaining structural stability remains the main challenge facing current thermal management technology. Summary of the Invention

[0005] The purpose of this application is to provide a press-fit preparation method for a high thermal conductivity circuit board and a high thermal conductivity circuit board, so as to solve the technical problem that the existing press-fit preparation process for high thermal conductivity circuit boards cannot effectively improve the overall thermal conductivity of the circuit board.

[0006] To achieve this goal, this application adopts the following technical solutions:

[0007] A method for laminating and preparing a high thermal conductivity circuit board, comprising:

[0008] The liquid metal gallium-indium alloy and fiber mixture are dispersed and solidified in an inert argon atmosphere and fused with the matrix to obtain an adaptive thermal conductive substrate;

[0009] Performing gradient deposition and etching on the adaptive thermal conductive substrate to obtain a gradient spacing template;

[0010] Electrospinning and heat treating the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network;

[0011] The substrate containing the dynamic heat conductive network is subjected to a conductive layer pre-pressing treatment to obtain a pre-assembled plate;

[0012] The pre-assembled panels are subjected to dynamic pressing in stages to obtain formed circuit boards;

[0013] The molded circuit board is subjected to surface spraying and deposition treatment to obtain the high thermal conductivity circuit board.

[0014] Furthermore, the step of dispersing and solidifying the liquid metal gallium-indium alloy and the fiber mixture in an inert argon atmosphere and fusing it with the matrix to obtain the adaptive thermal conductive substrate includes:

[0015] Mixing a liquid metal gallium-indium alloy and hydroxylated carbon fibers in a mass ratio of 1:3 to form a mixture, mechanically stirring the mixture at 500 rpm for 10 to 20 minutes in an inert argon atmosphere while applying low-frequency ultrasonic treatment to obtain a uniform suspension, wherein the molar mass ratio of gallium to indium in the liquid metal gallium-indium alloy is 4 to 5:1;

[0016] Adding the uniform suspension to a mixed solution of a polyimide precursor solution and graphene oxide, and treating under ultrasonic conditions to obtain a composite precursor liquid, wherein the mass ratio of the uniform suspension to the mixed solution is 1:5;

[0017] Passing the composite precursor liquid into a microfluidic channel for layered shearing treatment, wherein the width of the microfluidic channel is 50 μm and the flow rate is 0.1 mL / min, and an alternating electric field is applied in the channel to obtain a directional primary liquid;

[0018] The oriented primary liquid is poured into a mold and pre-cured in a vacuum oven at 100° C. for 40 minutes to obtain a primary cured substrate;

[0019] Orienting the pre-solidified substrate in a uniform magnetic field and cooling it to room temperature at a rate of 5° C. / min to obtain an oriented substrate, wherein the direction of the magnetic field is parallel to the length direction of the fibers;

[0020] The oriented substrate is subjected to a heat pressing process in a nitrogen atmosphere to obtain the self-adaptive thermally conductive substrate.

[0021] Furthermore, the step of performing gradient deposition and etching on the adaptive thermally conductive substrate to obtain a gradient spacing template includes:

[0022] Applying a silica gel layer of nano-aluminum oxide particles to the outer wall of the adaptive thermal conductive substrate to form a primary positioning substrate;

[0023] Obtaining the surface properties of the primary positioning substrate, injecting an ethanol solution of polydimethylsiloxane and nanocarbon fibers at a preset concentration according to the surface properties for deposition treatment to form a gradient layer with a thickness decreasing from 50 μm in the center to 5 μm at the edge, thereby obtaining a gradient thickness substrate;

[0024] According to the distribution of the gradient thickness substrate, a UV laser with a preset power is used to etch the substrate longitudinally to form V-shaped grooves, thereby obtaining a periodic groove substrate with a gradient spacing, wherein the groove spacing increases from 50 μm in the center to 100 μm at the edge;

[0025] Based on the vapor deposition technology, a suspension containing zinc oxide nanoparticles is injected into the surface of the periodic groove substrate to make the nanoparticles gradiently distributed along the groove depth direction to obtain the gradient spacing template, wherein the deposition pressure is 0.03~0.05MPa and the filling time is 10 minutes.

[0026] Furthermore, the step of etching the substrate longitudinally using an ultraviolet laser of preset power to form a V-groove according to the distribution of the gradient thickness substrate further includes:

[0027] Scanning longitudinally along the gradient thickness substrate using a laser scanning device to collect reflected light intensity and phase difference data corresponding to the thickness gradient;

[0028] Decomposing the reflected light intensity and phase difference data, calculating the spatial frequency components of each region, and obtaining a three-dimensional spectral data set containing thickness distribution characteristics;

[0029] Dividing the three-dimensional spectral data set into a plurality of discrete regions according to the thickness distribution characteristics, calculating the center coordinates and boundary curvature of each region, and obtaining a spatial annotation map;

[0030] Calculating the optimal focus position of the laser at each point on the spatially marked map, and obtaining the laser power based on the optimal focus position, and setting the laser power to the preset power;

[0031] According to the preset power, the gradient thickness substrate is longitudinally etched by using an ultraviolet laser device, so that a V-shaped groove is formed on the surface of the gradient thickness substrate.

[0032] Furthermore, the step of electrospinning and heat-treating the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network includes:

[0033] The gradient spacing template is subjected to electrospinning deposition treatment, and a formamide solution containing boron nitride nanosheets and polyvinylidene fluoride is sprayed onto the template surface at a flow rate of 0.5 mL / h to form a nanofiber layer with a thickness of about 20 μm;

[0034] The liquid metal is migrated along the V-shaped groove and infiltrated into the bottom of the nanofiber layer based on a pulsed electric field, and a low-temperature preheating treatment is performed to obtain a pre-cured thermal conductive substrate;

[0035] The pre-cured thermally conductive substrate is subjected to high-temperature heat treatment to form a local melt connection between the boron nitride nanosheets and the liquid metal in the micropores to construct a three-dimensional dynamic thermal conductive network, wherein the heating temperature is 680-700° C. and the heating time is 10-15 minutes;

[0036] A siloxane suspension containing aluminum oxide nanoparticles is injected into the surface of the substrate of the three-dimensional dynamic heat-conducting network under vacuum conditions to obtain a substrate containing a dynamic heat-conducting network.

[0037] Furthermore, the step of pre-pressing the conductive layer of the substrate containing the dynamic heat conductive network to obtain a pre-assembled plate comprises:

[0038] Placing the substrate containing the dynamic heat conductive network in a plasma treatment chamber, and performing surface plasma activation treatment using a mixed gas of argon and oxygen to form an activation layer rich in hydroxyl and carboxyl groups on the surface, thereby obtaining an activated substrate;

[0039] Depositing graphene-modified copper foil on the surface of the activation layer by chemical vapor deposition to form a diamond carbon film to obtain a composite conductive film;

[0040] The two composite conductive films are placed on the upper and lower sides of the activated substrate respectively, placed in a pre-alignment fixture, and pre-pressed at 120°C for 10 minutes to make the central area fit together and form a 5-10 μm microgap at the edge to obtain the pre-assembled plate.

[0041] Furthermore, the step of performing a staged dynamic pressing process on the pre-assembled panels to obtain a formed circuit board includes:

[0042] The preassembled sheet is placed in a pre-pressing machine and pre-pressed using a step-by-step temperature increase pre-pressing process to obtain a reinforced pre-assembled sheet, wherein the first stage of the step-by-step temperature increase pre-pressing process is a temperature of 200°C, a pressure of 10 MPa in the center area, and a pressure of 5 MPa at the edge, which is maintained for 20 minutes, so that the center area is completely sealed and the edge gap is compressed to 2 μm; the second stage is a temperature of 280°C, the pressure in the entire area is increased to 15 MPa, and maintained for 30 minutes;

[0043] The surface of the reinforced pre-assembled plate is flattened using mechanical polishing equipment to obtain the molded circuit board with a surface roughness of 100 nm, wherein the polishing liquid is an acidic suspension containing aluminum oxide particles.

[0044] Furthermore, the step of performing surface spraying and deposition treatment on the molded circuit board to obtain the high thermal conductivity circuit board includes:

[0045] The aqueous solution containing zinc oxide nanorods and microcapsules is evenly coated on the surface of the molded circuit board by ultrasonic spraying technology, the spraying pressure is 0.2 MPa, the coating thickness is controlled to be 15 μm, and thermally cured at 90° C. for 20 minutes to obtain a primary coating substrate;

[0046] Placing the primary coating substrate in an atomic layer deposition device, using titanium tetrachloride and ammonia as precursors, and depositing a titanium nitride protective film under vacuum conditions to obtain a protective layer substrate;

[0047] The protective layer substrate was placed in an annealing furnace in a nitrogen atmosphere, heated to 300° C. at a heating rate of 5° C. / min, maintained for 30 minutes, and then cooled to room temperature at a cooling rate of 3° C. / min to obtain the high thermal conductivity circuit board.

[0048] The present application also discloses a high thermal conductivity circuit board, which is manufactured using any of the above-mentioned pressing and manufacturing methods for high thermal conductivity circuit boards.

[0049] Compared with the prior art, this application has the following beneficial effects:

[0050] The pressing and preparing method of the high thermal conductivity circuit board of the present application can obtain an adaptive thermal conductive substrate by dispersing and solidifying a liquid metal and fiber mixture, forming a relatively uniform heat conduction network. The gradient deposition and etching processing technology is used to form a gradient spacing template on the surface of the substrate, which effectively optimizes the heat flow path, so that the heat flow can be efficiently transmitted along the predetermined path, avoiding the thermal interface effect, and further improving the thermal conductivity. The electrospinning infiltration and heat treatment technology are used to introduce a dynamic thermal conductive network into the substrate. The conductivity of the circuit board is improved by pre-pressing the conductive layer of the substrate and dynamically pressing it in stages. The heat resistance and oxidation resistance of the molded circuit board are enhanced by surface spraying and deposition treatment, further improving the reliability and long-term stable working ability of the circuit board.

[0051] In summary, this application solves the problems of poor heat flow path and poor interface bonding in the existing technology, and significantly improves the thermal management effect, especially in the field of high-power electronic equipment and integrated circuits. It can significantly improve the reliability and performance of electronic products and meet the market demand for high-efficiency thermal management materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0053] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size, without affecting the efficacy and objectives that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0054] Figure 1 Schematic diagram of the overall steps of the lamination preparation method for a high thermal conductivity circuit board;

[0055] Figure 2 A schematic diagram of the steps of an embodiment of a method for laminating a high thermal conductivity circuit board;

[0056] Figure 3 The figure is a schematic diagram of the steps of another embodiment of a method for laminating and preparing a high thermal conductivity circuit board. DETAILED DESCRIPTION

[0057] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described below are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0058] In the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting this application. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally located component.

[0059] The technical solution of the present application will be further explained below with reference to the accompanying drawings and through specific implementation methods.

[0060] refer to Figures 1 to 3 The present application provides a method for laminating and preparing a high thermal conductivity circuit board, comprising:

[0061] S1: The liquid metal gallium-indium alloy and the fiber mixture are dispersed and solidified in an inert argon atmosphere and fused with the matrix to obtain an adaptive thermal conductive substrate;

[0062] In step S1, the liquid metal has a high thermal conductivity and can be selected from materials such as gallium (Ga), aluminum (Al) and tin (Sn). In the liquid state, it can interact with the fiber mixture to form a composite material with high thermal conductivity. The liquid metal can fill the gaps in the fibers, forming a more continuous thermal conductive network structure and improving the heat conduction efficiency. The liquid metal and the fiber mixture are mixed in a certain proportion, which can be achieved by mechanical stirring or ultrasonic dispersion technology to ensure that the liquid metal and the fibers are evenly mixed and avoid agglomeration of the material during the curing process. In order to further improve the thermal conductivity of the composite material, some surfactants or additives can be added to improve the interfacial bonding between the liquid metal and the fibers, promote the formation of an interpenetrating network structure between the metal and the fibers, and perform the curing treatment under appropriate temperature and pressure conditions. After the curing process is completed, the liquid metal and fiber mixture will form an adaptive thermal conductive substrate with excellent thermal conductivity and a certain degree of adjustability and adaptability. A characteristic of adaptive thermally conductive substrates is that their thermal conductivity can be adjusted appropriately according to different usage conditions. For example, in certain high-power applications, thermal conductivity can be further improved by changing the liquid metal content or fiber distribution. This adaptive property makes the material widely applicable to various electronic devices with high heat loads, especially in the packaging of high-power electronic devices and integrated circuits.

[0063] S2: performing gradient deposition and etching on the adaptive thermal conductive substrate to obtain a gradient spacing template;

[0064] In step S2, gradient deposition refers to depositing materials layer by layer at varying densities or thicknesses to form regions with different physical properties. In this embodiment, the gradient deposition process can effectively adjust the thermal conductivity of the substrate. By controlling the deposition rate, the type of deposited material, and the deposition order, different regions of the circuit board can exhibit gradient differences in thermal conductivity, thereby selectively accelerating or slowing the heat flow through the circuit board as needed. Etching involves locally removing the deposited material, refining the circuit board's structure, and forming a microstructure with gradient spacing, which can significantly improve the heat flow path. Etching can be performed using dry or wet etching, depending on the characteristics of the deposited material and the desired final structural accuracy. Etching can control the morphology of the thermally conductive material, allowing the heat flow to be transferred along an optimized path, thereby improving the overall thermal conductivity of the circuit board. For example, gradient deposition can be performed using techniques such as laser melting deposition or electron beam deposition, where metal or composite materials are deposited layer by layer at a specific thickness on the substrate surface. The deposited materials may include metals, ceramics, or highly thermally conductive composite materials. Subsequently, an etching process removes some of the deposited material, forming a microscopic, hierarchical thermally conductive network structure. This gradient-pitch template optimizes the heat flow path, providing better thermal management between the heat source and the heat sink, ensuring that heat can quickly and efficiently diffuse from high-temperature areas to low-temperature areas. Through the combination of gradient deposition and etching, the microstructure formed on the circuit board surface maintains thermal conductivity while also enhancing the mechanical strength and stability of the substrate.

[0065] S3: electrospinning and heat treating the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network;

[0066] In step S3, the electrospinning infiltration process uses electrospinning technology to infiltrate materials into the structure of the gradient-spacing template. Thermally conductive materials or highly thermally conductive fibers are infiltrated into the template's microstructure, forming a network of heat-conducting channels. This enhances the circuit board's thermal conductivity during operation, ensuring rapid heat dissipation in high-power scenarios and preventing equipment overheating due to heat accumulation. Electrospinning technology stretches a polymer solution or molten material under a high electric field to form fine fibers. These fibers exhibit high specific surface area and microstructural properties. In this step, the materials used in the electrospinning process can be metal oxides, conductive polymers, or metal fibers with excellent thermal conductivity. After electrospinning, these fibers are infiltrated into the gradient-spacing template, forming a thermally conductive network structure. This provides highly optimized heat-conducting channels in the substrate, ensuring that heat can quickly diffuse from the heat-generating area to other parts of the circuit board. The electrospinning infiltration process controls the intensity of the electric field, the fiber stretching speed, the material viscosity, and the depth of penetration to ensure that the thermally conductive fibers evenly and effectively cover each microchannel in the template, thereby optimizing the efficiency of the thermal network. For example, by adjusting the electric field intensity, the fineness of the fibers can be controlled; by varying the solution viscosity, the fiber arrangement can be adjusted, further optimizing their thermal conductivity. After electrospinning, the infiltrated material is solidified or reinforced to form a stable thermally conductive network structure. Heat treatment conditions (such as temperature, time, and atmosphere) are optimized based on the properties of the material used. For example, for metal oxides or highly thermally conductive polymers, heat treatment can promote crystal growth or improve the thermal conductivity of the material, thereby enhancing the overall thermal conductivity of the substrate.

[0067] S4: pre-pressing the conductive layer of the substrate containing the dynamic thermal conductive network to obtain a pre-assembled plate;

[0068] In step S4, the dielectric properties of the circuit board are enhanced by pre-pressing the conductive layer. This pre-pressing process involves adding a conductive material to the substrate surface and physically or chemically bonding it to the substrate surface through pressure and heating, forming a strong conductive layer. The conductive layer can be made of metal materials (such as copper, silver, etc.) or conductive polymers. Metal materials are typically deposited on the substrate surface through methods such as sputtering, evaporation, or electroplating, while conductive polymers can be applied through coating or spraying. The deposition and pressing of these conductive materials ensures a uniform, stable, and highly conductive conductive layer on the circuit board surface. Taking copper as an example, in step S4, a copper layer can be evenly plated onto the substrate surface, which has been treated with a dynamic thermal network. This layer firmly bonds to the substrate surface, forming a stable conductive path. During the electroplating process, the copper deposition rate and thickness are controlled to ensure the uniformity and integrity of the conductive layer. Furthermore, a heat treatment can be performed after electroplating to further enhance the bonding between the copper layer and the substrate, further stabilizing the conductive layer. The pre-pressing treatment can tightly bond the conductive layer to various parts of the substrate, reducing interface separation or interlayer detachment problems that may occur due to thermal expansion or external forces.

[0069] S5: Performing dynamic pressing on the pre-assembled panels in stages to obtain a formed circuit board;

[0070] In step S5, a stable conductive layer has formed on the surface of the pre-assembled sheets. Pressing is then performed in multiple stages, with different parameters (such as pressure and temperature) controlled in each stage. This ensures uniform compression and heat treatment of the sheets throughout the pressing process, optimizing the bond between the conductive layer and the substrate, and ensuring a secure bond between the layers without defects such as delamination, voids, or bubbles. Furthermore, by controlling the pressing conditions in stages, stress concentration and unevenness can be effectively avoided, ensuring that the circuit board maintains high thermal conductivity and mechanical strength after pressing. In practice, the staged dynamic pressing process may include an initial low-pressure, low-temperature treatment. This stage aims to flatten the pre-assembled sheets at low temperatures and ensure initial bonding between the layers. As the pressing progresses, the temperature and pressure gradually increase, entering the medium-pressure stage. Controlling the temperature and pressure is critical at this stage, as excessively high temperatures and pressures may damage the conductive layer or substrate, while excessively low temperatures and pressures may prevent sufficient bonding. Finally, in the final pressing stage, concentrated high-temperature and high-pressure treatment ensures complete bonding between the conductive layer and the substrate, forming the final finished circuit board. This process needs to ensure uniform distribution of heat treatment and pressure to avoid local overheating or overpressure causing damage to the circuit board or uneven performance.

[0071] S6: performing surface spraying and deposition treatment on the formed circuit board to obtain the high thermal conductivity circuit board.

[0072] In step S6, spraying and depositing coatings on the circuit board surface can effectively improve its thermal conductivity and prevent functional failure caused by overheating in high-temperature environments. Surface spraying primarily involves spraying a liquid coating or powdered material onto the circuit board's surface to form a uniform coating. These coatings have high thermal conductivity and can effectively improve the circuit board's thermal conductivity. In practice, the materials used can include metal-based coatings, such as silver or copper, or polymer coatings containing highly thermally conductive fillers. These coatings can quickly transfer heat from the circuit board to other parts of the circuit board when high-power current flows through it, preventing localized overheating. Furthermore, the spraying process allows for customized adjustment of the coating's thickness, uniformity, and adhesion, ensuring that the coating adheres securely to the circuit board's surface and resists detachment or cracking due to long-term use. Surface deposition treatments, using techniques such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), deposit a thin layer of metal or non-metallic material onto the circuit board's surface. This increases the circuit board's electrical conductivity and thermal conductivity. Through these deposition processes, a uniform and strong thermal conductive coating can be formed on the surface of the circuit board, thereby improving the heat dissipation capacity of the circuit board and ensuring that it can still work stably in high temperature environments.

[0073] In one embodiment, reference Figure 2 The step of dispersing and solidifying the liquid metal gallium-indium alloy and the fiber mixture in an inert argon atmosphere and fusing it with the matrix to obtain an adaptive thermal conductive substrate includes:

[0074] S21: mixing a liquid metal gallium-indium alloy and a hydroxylated carbon fiber in a mass ratio of 1:3 to form a mixture, and mechanically stirring the mixture at 500 rpm for 10 to 20 minutes in an inert argon atmosphere while applying low-frequency ultrasonic treatment to obtain a uniform suspension, wherein the molar mass ratio of gallium to indium in the liquid metal gallium-indium alloy is 4 to 5:1;

[0075] S22: adding the uniform suspension to a mixed solution of a polyimide precursor solution and graphene oxide, and treating the mixture under ultrasonic conditions to obtain a composite precursor solution, wherein the mass ratio of the uniform suspension to the mixed solution is 1:5;

[0076] S23: passing the composite precursor liquid into a microfluidic channel for layered shearing treatment, wherein the width of the microfluidic channel is 50 μm and the flow rate is 0.1 mL / min, and an alternating electric field is applied in the channel to obtain a directional primary liquid;

[0077] S24: pouring the oriented primary liquid into a mold and pre-curing it in a vacuum oven at 100° C. for 40 minutes to obtain a primary cured substrate;

[0078] S25: Orienting the pre-solidified substrate in a uniform magnetic field and cooling it to room temperature at a rate of 5° C. / min to obtain an oriented substrate, wherein the direction of the magnetic field is parallel to the length direction of the fibers;

[0079] S26: performing a hot pressing process on the oriented substrate in a nitrogen atmosphere to obtain the adaptive thermally conductive substrate.

[0080] In the above embodiment, a liquid metal gallium-indium alloy with a molar ratio of gallium to indium of 4-5:1 was used. Gallium-indium alloy is liquid at room temperature and has excellent thermal conductivity, effectively improving the thermal conductivity of the composite material. The liquid metal was mixed with hydroxylated carbon fibers at a mass ratio of 1:3. The hydroxylated carbon fibers were 50 μm in length and had undergone a hydroxylation treatment to enhance the hydrophilicity and reactivity of the carbon fiber surface, thereby improving its bonding with the metal alloy. In this step, the mixture was stirred in an inert atmosphere (such as argon) to prevent oxidation. Within this atmosphere, mechanical stirring was performed at 500 rpm, while low-frequency ultrasonic treatment was applied for 10 to 20 minutes. The ultrasonic treatment effectively breaks up carbon fiber agglomerations through the vibration of the sound waves and the collapse of tiny bubbles, promoting uniform dispersion of the liquid metal within the fibers, thereby forming a stable, uniform suspension. A homogeneous suspension was mixed with a polyimide (PI) precursor solution. The PI precursor has excellent thermal stability and good mechanical properties. Graphene oxide (GO) was added as a dispersant to improve the dispersion of the solution and enhance the thermal conductivity and mechanical strength of the composite. The mass ratio of the homogeneous suspension to the PI solution and GO mixture was 1:5. To ensure uniform mixing of the components, the mixture was treated with ultrasound at a frequency of 40 kHz and a power of 200 W for 30 minutes. The ultrasound further promoted thorough mixing of the components, preventing stratification and inhomogeneity, thereby improving the homogeneity and performance of the composite. The resulting composite precursor solution was then injected into a microfluidic channel for a layered shear treatment. Microfluidics enables precise control of fluid flow, achieving orderly arrangement of the components within the tiny channel. During this process, the microfluidic channel width was set to 50 μm, and the flow rate was 0.1 mL / min. Under these conditions, the components in the liquid will be subjected to a certain shear force during flow, prompting them to align in a specific manner. An alternating electric field is applied in the channel, and the electric field is used to further align the liquid metal and carbon fibers in a specific direction, forming an oriented primary liquid. The guiding effect of the electric field can promote the oriented arrangement of fibers and metal particles, thereby forming a more effective heat conduction channel in the subsequent substrate. The oriented primary liquid is poured into the mold and pre-cured in a vacuum oven at 100°C for 40 minutes. The low-temperature vacuum environment allows the material to be formed without being fully cured, maintaining high fluidity and avoiding the generation of bubbles, ensuring the density and surface smoothness of the substrate. After pre-curing, the material obtains a preliminary structural form, forming a substrate with a thickness of 0.8mm. It is then oriented using a magnetic field. The magnetic field aligns the liquid metal and carbon fibers in a certain direction. The direction of the magnetic field is parallel to the length of the fiber, promoting the conduction of heat along the fiber direction, thereby forming an efficient heat conduction channel.The magnetic field strength was set to 0.5 T, effectively inducing the alignment of the liquid metal and carbon fibers in the composite material. After treatment, the material was cooled to room temperature at a rate of 5°C / min to prevent excessive thermal stress and deformation during the cooling process. The oriented substrate was then hot-pressed to further enhance its thermal conductivity and mechanical strength. The hot-pressing process was performed in a nitrogen atmosphere to prevent oxidation. The hot-pressing process formed a tighter bond between the fibers, metal, and polyimide in the substrate, improving the overall thermal conductivity and mechanical stability of the material. This adaptive thermally conductive substrate exhibits adaptive thermal conductivity at different temperatures. For example, at 25°C, the thermal conductivity of the substrate is 10 W / (m·K), increasing to 18 W / (m·K) at 150°C. This characteristic makes the substrate more temperature-adaptable than existing static filler substrates, enabling it to maintain excellent thermal conductivity across a wide range of operating temperatures, thus meeting the heat dissipation requirements of high-performance electronic devices.

[0081] In one embodiment, the step of performing gradient deposition and etching on the adaptive thermally conductive substrate to obtain a gradient spacing template includes:

[0082] Applying a silica gel layer of nano-aluminum oxide particles to the outer wall of the adaptive thermal conductive substrate to form a primary positioning substrate;

[0083] Obtaining the surface properties of the primary positioning substrate, injecting an ethanol solution of polydimethylsiloxane and nanocarbon fibers at a preset concentration according to the surface properties for deposition treatment to form a gradient layer with a thickness decreasing from 50 μm in the center to 5 μm at the edge, thereby obtaining a gradient thickness substrate;

[0084] According to the distribution of the gradient thickness substrate, a UV laser with a preset power is used to etch the substrate longitudinally to form V-shaped grooves, thereby obtaining a periodic groove substrate with a gradient spacing, wherein the groove spacing increases from 50 μm in the center to 100 μm at the edge;

[0085] Based on the vapor deposition technology, a suspension containing zinc oxide nanoparticles is injected into the surface of the periodic groove substrate to make the nanoparticles gradiently distributed along the groove depth direction to obtain the gradient spacing template, wherein the deposition pressure is 0.03~0.05MPa and the filling time is 10 minutes.

[0086] In the above-described embodiment, a silica gel layer containing nano-alumina particles was used for coating. Nano-alumina particles have excellent thermal conductivity and, when used as a coating within silica gel, can improve the adhesion and stability of the coating. This formed a primary positioning substrate. An ethanol solution of polydimethylsiloxane (PDMS) and carbon nanofibers was then injected layer by layer onto the substrate surface to form a gradient layer with a thickness decreasing from 50 μm at the center to 5 μm at the edges. To achieve this effect, microfluidics technology was used to inject the solution layer by layer through a 20 μm-wide microchannel. This ensured precise control of the solution, resulting in a gradient layer with a uniform thickness transition from the center to the edges, while maintaining a good deposition effect. After the gradient layer was deposited, the substrate was placed in a high-temperature environment and cured at 150°C for 20 minutes. This allowed the polydimethylsiloxane to crosslink, forming a strong network structure. The carbon nanofibers were then fixed to the substrate, thereby enhancing the substrate's mechanical properties and thermal conductivity. Based on the distribution of the gradient thickness substrate, an ultraviolet laser was used for etching, removing a portion of the substrate surface material through the intense laser energy. In this embodiment, the wavelength of the laser is set to 266nm, the power is 5W, and the laser etches longitudinally along the substrate to form a V-shaped groove with a depth of 10μm and an angle of 30°. During the etching process, the groove spacing gradually increases from 50μm in the center of the substrate to 100μm at the edge. The periodic structure of the groove enables the substrate to form an orderly heat conduction channel during heat conduction, effectively enhancing the heat conduction efficiency, and the design of this periodic groove helps to optimize the heat flow path of the substrate and improve the overall heat dissipation performance. A suspension containing zinc oxide nanoparticles is injected into the surface of the substrate. Through vapor deposition, the zinc oxide nanoparticles gradually form a gradient distribution along the groove depth direction. The deposition pressure is controlled between 0.03 and 0.05MPa, and the filling time is 10 minutes, so that the zinc oxide particles form a gradual structure in the groove depth direction, thereby further improving the thermal conductivity and surface stability of the substrate.

[0087] In one embodiment, the step of etching the substrate longitudinally using an ultraviolet laser of preset power to form a V-groove according to the distribution of the gradient thickness substrate further includes:

[0088] Scanning longitudinally along the gradient thickness substrate using a laser scanning device to collect reflected light intensity and phase difference data corresponding to the thickness gradient;

[0089] Decomposing the reflected light intensity and phase difference data, calculating the spatial frequency components of each region, and obtaining a three-dimensional spectral data set containing thickness distribution characteristics;

[0090] Dividing the three-dimensional spectral data set into a plurality of discrete regions according to the thickness distribution characteristics, calculating the center coordinates and boundary curvature of each region, and obtaining a spatial annotation map;

[0091] Calculating the optimal focus position of the laser at each point on the spatially marked map, and obtaining the laser power based on the optimal focus position, and setting the laser power to the preset power;

[0092] According to the preset power, the gradient thickness substrate is longitudinally etched by using an ultraviolet laser device, so that a V-shaped groove is formed on the surface of the gradient thickness substrate.

[0093] In this embodiment, a laser scanning device is controlled to scan longitudinally along a gradient thickness substrate, and a sensor is used to collect reflected light intensity and phase difference data. The reflected light intensity and phase difference reflect the surface characteristics of the substrate, especially the change in surface thickness. Since the thickness of the substrate varies in a gradient, the collection of these optical parameters can reflect the thickness information of different regions in real time. The collected reflected light intensity and phase difference data will be decomposed and processed. By decomposing the data, the spatial frequency components of each region can be extracted. These components contain details of the surface thickness distribution. The calculation of the spatial frequency components can help analyze the reflective characteristics of different regions of the substrate under the action of light, thereby obtaining the thickness variation of each region. This process is completed through technical means such as Fourier transform of the data. It is possible to extract valuable information from complex data, form a three-dimensional spectral data set, and divide it into multiple discrete regions according to the thickness distribution characteristics. Dividing the entire substrate surface into different regions allows each region to be processed separately, thereby achieving more precise etching. After each division, the center coordinates and boundary curvature of each area are calculated, such as the center position and shape of each area, to generate a spatial annotation map. The purpose of the spatial annotation map is to mark the key feature points of each area, including the thinnest and thickest areas, and calculate the optimal focus position of the laser in each area of the spatial annotation map. Because the thickness and curvature of different areas vary, the laser focus position must be adjusted according to these changes to ensure that the laser can effectively focus on the optimal position in each area, thereby improving the accuracy and efficiency of etching. The laser power is adjusted based on these positions. In actual operation, the laser power setting is precisely controlled according to the desired etching depth and the optical properties of the substrate. By adjusting the laser power, the depth of different areas can be controlled, ensuring that the depth and shape of the V-groove meet the desired depth. Based on the preset power, the gradient thickness substrate is longitudinally etched using ultraviolet laser equipment, forming a V-groove on the substrate surface.

[0094] In another embodiment, the calculation expression of the above steps on the computer device is:

[0095] ;

[0096] in, is the power of the UV laser, which represents the laser power at each position (x, y coordinate) on the substrate surface; Ω is the integration area, which represents the entire scanning area on the substrate surface; is the optical property function of the substrate at position x, y, representing the reflectivity and absorptivity of the substrate surface; Reflected light intensity and phase difference Fourier transform of the data to extract the spatial frequency components of the surface; is the thickness distribution function, the thickness distribution of the substrate Obtained by Fourier transform, and the region partition function Combined, it is used to divide the surface into regions; Adjust the laser focus function to ensure the best focus of the laser in each area; It is the area element per unit area on the surface, representing a tiny area on the substrate surface.

[0097] In one embodiment, the step of electrospinning and heat-treating the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network comprises:

[0098] The gradient spacing template is subjected to electrospinning deposition treatment, and a formamide solution containing boron nitride nanosheets and polyvinylidene fluoride is sprayed onto the template surface at a flow rate of 0.5 mL / h to form a nanofiber layer with a thickness of about 20 μm;

[0099] The liquid metal is migrated along the V-shaped groove and infiltrated into the bottom of the nanofiber layer based on a pulsed electric field, and a low-temperature preheating treatment is performed to obtain a pre-cured thermal conductive substrate;

[0100] The pre-cured thermally conductive substrate is subjected to high-temperature heat treatment to form a local melt connection between the boron nitride nanosheets and the liquid metal in the micropores to construct a three-dimensional dynamic thermal conductive network, wherein the heating temperature is 680-700° C. and the heating time is 10-15 minutes;

[0101] A siloxane suspension containing aluminum oxide nanoparticles is injected into the surface of the substrate of the three-dimensional dynamic heat-conducting network under vacuum conditions to obtain a substrate containing a dynamic heat-conducting network.

[0102] In this example, a solution containing 10 wt% boron nitride nanosheets (BNNS) and polyvinylidene fluoride (PVDF) (DMF solvent) was electrospun onto the surface of a gradient-pitch template at a rate of 0.5 mL / h, forming a nanofiber layer approximately 20 μm thick. Electrospinning, a process that uses an electric field to drive a polymer solution or melt into fibers, enables the formation of nanoscale fibers, providing a large surface area for liquid metal penetration. The conditions were an electrospinning voltage of 15 kV and a receiving distance of 10 cm. A pulsed electric field (5 kV / cm, 1 Hz) was used to migrate the liquid metal along the V-shaped grooves on the gradient template surface and penetrate into the bottom of the nanofiber layer. The special effect of the pulsed electric field drove the liquid metal to flow in a short period of time and penetrate the bottom of the fiber layer, filling the template's tiny pores, promoting connections between nanofibers and enhancing the connectivity of the thermal network. After a low-temperature preheating treatment, the liquid metal penetrated at a lower temperature and initially bonded to the fiber layer surface. A high-temperature hot pressing process, performed at a temperature range of 680-700°C for 10-15 minutes, allows the boron nitride nanosheets and liquid metal to form localized fusion bonds within the micropores, thereby constructing a three-dimensional dynamic thermal network. At this temperature, the boron nitride nanosheets have excellent thermal stability, while the liquid metal, nearing its melting point, effectively fuses with the boron nitride nanosheets to form a three-dimensional network structure. Under vacuum conditions, a siloxane suspension containing aluminum oxide nanoparticles is injected onto the surface of the three-dimensional dynamic thermal network substrate, forming a protective film containing aluminum oxide nanoparticles, further enhancing the material's thermal conductivity and surface stability. Alumina, a common high-thermal conductivity material, effectively improves the substrate's overall thermal conductivity, while siloxane provides enhanced interfacial adhesion, ensuring a stable distribution of the aluminum oxide particles on the substrate surface. Performing the injection process under vacuum effectively prevents the effects of moisture and other impurities in the air on material properties, thereby ensuring the high quality of the final product. This embodiment uses the fluidity of liquid metal to achieve an adaptive heat conduction path under heat load, and the thermal conductivity coefficient is increased to 25W / (m·K). Different from the existing static filler network, it provides a high-performance substrate.

[0103] In one embodiment, the step of subjecting the substrate containing the dynamic thermal conductive network to a pre-pressing treatment of the conductive layer to obtain a pre-assembled plate comprises:

[0104] Placing the substrate containing the dynamic heat conductive network in a plasma treatment chamber, and performing surface plasma activation treatment using a mixed gas of argon and oxygen to form an activation layer rich in hydroxyl and carboxyl groups on the surface, thereby obtaining an activated substrate;

[0105] Depositing graphene-modified copper foil on the surface of the activation layer by chemical vapor deposition to form a diamond carbon film to obtain a composite conductive film;

[0106] The two composite conductive films are placed on the upper and lower sides of the activated substrate respectively, placed in a pre-alignment fixture, and pre-pressed at 120°C for 10 minutes to make the central area fit together and form a 5-10 μm microgap at the edge to obtain the pre-assembled plate.

[0107] In this embodiment, the substrate containing the dynamic thermal network is pretreated via surface plasma activation, performed within a plasma treatment chamber using a mixture of argon and oxygen. Plasma activation activates the substrate surface with high-energy plasma, forming an activated layer rich in hydroxyl (–OH) and carboxyl (–COOH) groups. This results in a higher surface energy, significantly improving the adhesion of subsequent materials. This is particularly true when applying a conductive layer, effectively enhancing the adhesion and stability of the conductive film. After surface activation, graphene-modified copper foil is deposited onto the activated substrate via chemical vapor deposition (CVD). Graphene-modified copper foil is a copper foil modified with graphene, with a graphene content of 2wt%. This modification improves the copper foil's thermal and electrical conductivity. A 5μm-thick diamond-like carbon film (DLC) is grown on the surface of the graphene-modified copper foil via CVD. Diamond-like carbon (DLC) films exhibit excellent hardness and wear resistance. The two composite conductive films are placed on the upper and lower sides of the activated substrate and clamped in a pre-alignment fixture. The pre-alignment fixture ensures accurate positioning of the conductive films throughout the pre-pressing process, preventing quality issues caused by offset or uneven pressure. The entire assembly is pre-pressed at 120°C for 10 minutes. The 120°C temperature ensures appropriate material deformation during pressing, ensuring a secure bond between the substrate and the conductive film in the center while maintaining a micro-gap of 5 to 10μm at the edges. The pre-assembled plate obtained through the above steps can effectively conduct the heat generated by the electronic components to the substrate, thereby improving the heat dissipation efficiency and extending the service life of the equipment.

[0108] In one embodiment, the step of performing a staged dynamic pressing process on the pre-assembled panels to obtain a formed circuit board includes:

[0109] The preassembled sheet is placed in a pre-pressing machine and pre-pressed using a step-by-step temperature increase pre-pressing process to obtain a reinforced pre-assembled sheet, wherein the first stage of the step-by-step temperature increase pre-pressing process is a temperature of 200°C, a pressure of 10 MPa in the center area, and a pressure of 5 MPa at the edge, which is maintained for 20 minutes, so that the center area is completely sealed and the edge gap is compressed to 2 μm; the second stage is a temperature of 280°C, the pressure in the entire area is increased to 15 MPa, and maintained for 30 minutes;

[0110] The surface of the reinforced pre-assembled plate is flattened using mechanical polishing equipment to obtain the molded circuit board with a surface roughness of 100 nm, wherein the polishing liquid is an acidic suspension containing aluminum oxide particles.

[0111] In this embodiment, the preassembled sheet is placed in a pre-pressing machine and pre-pressed using a step-by-step temperature increase pre-pressing process. Through precise temperature and pressure control, the preassembled sheet can undergo different pressing conditions at different stages to achieve optimal fit and performance. In the first stage, the temperature is set to 200°C, and a pressure of 10 MPa is applied to the central area of the preassembled sheet, while a pressure of 5 MPa is applied to the edge area for 20 minutes. The goal of this stage is to make the central area of the preassembled sheet completely tight, while the micro-gap in the edge area is compressed to 2μm. In this stage, the combined effects of heat and pressure gradually tighten the internal structure of the preassembled sheet, ensuring good contact between the high thermal conductivity materials and reducing bubbles or voids caused by insufficient pressure. In the second stage, the temperature is further increased to 280°C, and the pressure in the entire area is increased to 15 MPa, and this pressure is maintained for 30 minutes. At this point, the increased temperature and pressure cause liquid metal or other filler material to migrate within the microgaps, further filling the tiny voids left by the first stage of lamination. The combined effects of pressure and temperature allow the liquid metal to fully fill all microgaps, resulting in a uniform structure, reducing interlayer contact problems and optimizing the circuit board's thermal conductivity. This process strengthens the entire pre-assembled board, creating a more uniform pressure distribution between the center and edge regions, ensuring balanced thermal conductivity. X-ray tomography further verified the interlayer spacing distribution, revealing a 0μm interlayer spacing in the center and 2μm at the edge. This gradient heat flow structure helps optimize thermal conductivity, effectively distributing and conducting heat and preventing localized overheating. After the staged dynamic lamination process, mechanical polishing equipment is used for planarization. Chemical mechanical polishing (CMP) can be used to achieve the desired surface smoothness and precision through a combination of physical and chemical processes. In this embodiment, the polishing liquid utilizes an acidic suspension containing aluminum oxide particles. These particles act as an abrasive during the polishing process, effectively removing minor surface irregularities and further improving the surface quality of the circuit board. During this process, the aluminum oxide particles physically rub against the surface, smoothing out any surface roughness. This results in a smoother surface structure on the final printed circuit board, thereby enhancing its performance and stability.

[0112] In one embodiment, reference Figure 3 The step of performing surface spraying and deposition treatment on the molded circuit board to obtain the high thermal conductivity circuit board includes:

[0113] S61: uniformly coating the aqueous solution containing zinc oxide nanorods and microcapsules on the surface of the molded circuit board by ultrasonic spraying technology, with a spraying pressure of 0.2 MPa and a coating thickness controlled at 15 μm, and thermally curing at 90° C. for 20 minutes to obtain a primary coating substrate;

[0114] S62: placing the primary coating substrate in an atomic layer deposition device, using titanium tetrachloride and ammonia as precursors, and depositing a titanium nitride protective film under vacuum conditions to obtain a protective layer substrate;

[0115] S63: placing the protective layer substrate in an annealing furnace in a nitrogen atmosphere, heating it to 300° C. at a heating rate of 5° C. / min, maintaining it for 30 minutes, and then cooling it to room temperature at a cooling rate of 3° C. / min to obtain the high thermal conductivity circuit board.

[0116] In this example, an aqueous solution containing zinc oxide nanorods and microcapsules was evenly coated on the surface of a prefabricated circuit board using ultrasonic spraying technology. The zinc oxide nanorods (ZnO) have excellent thermal conductivity and an aspect ratio of 10:1, effectively enhancing the coating's thermal conductivity. The microcapsules contained liquid gallium (5μm particle size), which exhibits self-healing properties when exposed to heat or mechanical damage. The spraying pressure was controlled at 0.2 MPa to ensure uniform coating without bubbles or irregularities. The coating thickness after spraying was controlled at 15μm, providing a sufficient protective layer without affecting circuit board performance. After spraying, the prefabricated circuit board was heat-cured at 90°C for 20 minutes to ensure the coating's robustness and stability, thereby producing a pre-coated substrate. The pre-coated substrate was then deposited in an atomic layer deposition (ALD) apparatus using titanium tetrachloride (TiCl4) and ammonia (NH3) as precursors under vacuum conditions to form a titanium nitride (TiN) protective film. Atomic layer deposition technology ensures uniformity and precise thickness of the deposited film by controlling the deposition of each layer during the reaction. In this embodiment, the deposited titanium nitride film has a thickness of 30nm. The application of this film can effectively enhance the wear resistance and oxidation resistance of the circuit board surface. The protective layer substrate with the titanium nitride film deposited is placed in an annealing furnace in a nitrogen atmosphere for annealing. The temperature is increased at a rate of 5°C / min to 300°C and held for 30 minutes, followed by cooling to room temperature at a rate of 3°C / min. The annealing process improves the density and stability of the film layer, helping the film layer to better bond with the circuit board surface, thereby enhancing the durability and thermal stability of the protective film. During this annealing process, due to the presence of a nitrogen atmosphere, the nitrogen in the protective film reacts with titanium to form a solid titanium nitride structure, further improving the chemical stability of the film layer and enhancing the thermal stability and weather resistance of the circuit board. In this embodiment, the self-healing function of the microcapsules enables the circuit board to automatically release liquid gallium when heated or mechanically damaged, repairing surface defects and restoring thermal conductivity. For example, when a circuit board is squeezed or scratched by external forces, the surface microcapsules rupture, and the released liquid gallium can fill the surface damage, preventing the damage to the thermal conductive layer from affecting the performance of the circuit board and improving its durability. In another embodiment, after undergoing 500 thermal cycle tests (temperature range from -50°C to 200°C), the thermal conductivity of the circuit board remained stable at 30W / (m·K), indicating that the coating can maintain good thermal conductivity and operate continuously and stably under extreme temperature fluctuations. This performance is particularly suitable for high-power applications such as high-speed electronic components and lasers, allowing high-thermal conductivity circuit boards to not only operate stably under high temperature conditions but also effectively resist mechanical damage or surface defects that may occur during long-term use.

[0117] It is worth noting that all the devices described in this application are achievable using existing technologies, the algorithms described are based on mature algorithms from existing technologies, and the chemicals and conditions used in the preparation process are within a safe range and pose no risk to operators or the environment. Furthermore, the resulting high-thermal-conductivity circuit board exhibits excellent thermal conductivity and self-healing capabilities, demonstrating good reliability and stability.

[0118] The present invention also discloses a high thermal conductivity circuit board, which is manufactured by using any of the above-mentioned pressing and preparing methods for high thermal conductivity circuit boards.

[0119] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for laminating a high thermal conductivity circuit board, characterized in that: include: The liquid metal gallium-indium alloy and fiber mixture are dispersed and solidified in an inert argon atmosphere and fused with the matrix to obtain an adaptive thermal conductive substrate; Performing gradient deposition and etching on the adaptive thermal conductive substrate to obtain a gradient spacing template; Electrospinning and heat treating the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network; The substrate containing the dynamic heat conductive network is subjected to a conductive layer pre-pressing treatment to obtain a pre-assembled plate; The pre-assembled panels are subjected to dynamic pressing in stages to obtain formed circuit boards; Performing surface spraying and deposition treatment on the formed circuit board to obtain the high thermal conductivity circuit board; The step of electrospinning and heat-treating the gradient spacing template to obtain a substrate containing a dynamic thermal conductive network comprises: The gradient spacing template was subjected to electrospinning deposition treatment, and a formamide solution containing boron nitride nanosheets and polyvinylidene fluoride was sprayed onto the template surface at a flow rate of 0.5 mL / h to form a nanofiber layer with a thickness of 20 μm; The liquid metal is migrated along the V-shaped groove and infiltrated into the bottom of the nanofiber layer based on a pulsed electric field, and a low-temperature preheating treatment is performed to obtain a pre-cured thermal conductive substrate; The pre-cured thermally conductive substrate is subjected to high-temperature heat treatment to form a local melt connection between the boron nitride nanosheets and the liquid metal in the micropores to construct a three-dimensional dynamic thermal conductive network, wherein the heating temperature is 680-700° C. and the heating time is 10-15 minutes; A siloxane suspension containing aluminum oxide nanoparticles is injected into the surface of the substrate of the three-dimensional dynamic heat-conducting network under vacuum conditions to obtain a substrate containing a dynamic heat-conducting network.

2. The method for laminating a high thermal conductivity circuit board according to claim 1, wherein: The step of dispersing and solidifying the liquid metal gallium-indium alloy and the fiber mixture in an inert argon atmosphere and fusing the mixture with the matrix to obtain an adaptive thermal conductive substrate comprises: Mixing a liquid metal gallium-indium alloy and hydroxylated carbon fibers in a mass ratio of 1:3 to form a mixture, mechanically stirring the mixture at 500 rpm for 10 to 20 minutes in an inert argon atmosphere while applying low-frequency ultrasonic treatment to obtain a uniform suspension, wherein the molar mass ratio of gallium to indium in the liquid metal gallium-indium alloy is 4 to 5:1; Adding the uniform suspension to a mixed solution of a polyimide precursor solution and graphene oxide, and treating under ultrasonic conditions to obtain a composite precursor liquid, wherein the mass ratio of the uniform suspension to the mixed solution is 1:5; Passing the composite precursor liquid into a microfluidic channel for layered shearing treatment, wherein the width of the microfluidic channel is 50 μm and the flow rate is 0.1 mL / min, and an alternating electric field is applied in the channel to obtain a directional primary liquid; The oriented primary liquid is poured into a mold and pre-cured in a vacuum oven at 100° C. for 40 minutes to obtain a primary cured substrate; Orienting the pre-solidified substrate in a uniform magnetic field and cooling it to room temperature at a rate of 5° C. / min to obtain an oriented substrate, wherein the direction of the magnetic field is parallel to the length direction of the fibers; The oriented substrate is subjected to a heat pressing process in a nitrogen atmosphere to obtain the self-adaptive thermally conductive substrate.

3. The method for preparing a high thermal conductivity circuit board by pressing according to claim 1, characterized in that: The step of performing gradient deposition and etching on the adaptive thermal conductive substrate to obtain a gradient spacing template includes: Applying a silica gel layer of nano-aluminum oxide particles to the outer wall of the adaptive thermal conductive substrate to form a primary positioning substrate; Obtaining the surface properties of the primary positioning substrate, injecting an ethanol solution of polydimethylsiloxane and nanocarbon fibers at a preset concentration according to the surface properties for deposition treatment to form a gradient layer with a thickness decreasing from 50 μm in the center to 5 μm at the edge, thereby obtaining a gradient thickness substrate; According to the distribution of the gradient thickness substrate, a UV laser with a preset power is used to etch the substrate longitudinally to form V-shaped grooves, thereby obtaining a periodic groove substrate with a gradient spacing, wherein the groove spacing increases from 50 μm in the center to 100 μm at the edge; Based on the vapor deposition technology, a suspension containing zinc oxide nanoparticles is injected into the surface of the periodic groove substrate to make the nanoparticles gradiently distributed along the groove depth direction to obtain the gradient spacing template, wherein the deposition pressure is 0.03~0.05 MPa and the filling time is 10 minutes.

4. The method for preparing a high thermal conductivity circuit board by pressing according to claim 3, characterized in that: The step of etching the substrate longitudinally using an ultraviolet laser of preset power to form a V-shaped groove according to the distribution of the gradient thickness substrate further includes: Scanning longitudinally along the gradient thickness substrate using a laser scanning device to collect reflected light intensity and phase difference data corresponding to the thickness gradient; Decomposing the reflected light intensity and phase difference data, calculating the spatial frequency components of each region, and obtaining a three-dimensional spectral data set containing thickness distribution characteristics; Dividing the three-dimensional spectral data set into a plurality of discrete regions according to the thickness distribution characteristics, calculating the center coordinates and boundary curvature of each region, and obtaining a spatial annotation map; Calculating the optimal focus position of the laser at each point on the spatially marked map, and obtaining the laser power based on the optimal focus position, and setting the laser power to the preset power; According to the preset power, the gradient thickness substrate is longitudinally etched by using an ultraviolet laser device, so that a V-shaped groove is formed on the surface of the gradient thickness substrate.

5. The method for laminating a high thermal conductivity circuit board according to claim 1, wherein: The step of subjecting the substrate containing the dynamic heat conductive network to a conductive layer pre-pressing treatment to obtain a pre-assembled plate comprises: Placing the substrate containing the dynamic heat conductive network in a plasma treatment chamber, and performing surface plasma activation treatment using a mixed gas of argon and oxygen to form an activation layer rich in hydroxyl and carboxyl groups on the surface, thereby obtaining an activated substrate; Depositing graphene-modified copper foil on the surface of the activation layer by chemical vapor deposition to form a diamond carbon film to obtain a composite conductive film; The two composite conductive films are placed on the upper and lower sides of the activated substrate respectively, placed in a pre-alignment fixture, and pre-pressed at 120°C for 10 minutes to make the central area fit together and form a 5-10 μm microgap at the edge to obtain the pre-assembled plate.

6. The method for laminating a high thermal conductivity circuit board according to claim 1, wherein: The step of performing a staged dynamic pressing process on the pre-assembled panels to obtain a formed circuit board comprises: The preassembled sheet is placed in a pre-pressing machine and pre-pressed using a step-by-step temperature increase pre-pressing process to obtain a reinforced pre-assembled sheet, wherein the first stage of the step-by-step temperature increase pre-pressing process is a temperature of 200°C, a pressure of 10 MPa in the center area, and a pressure of 5 MPa at the edge, which is maintained for 20 minutes, so that the center area is completely sealed and the edge gap is compressed to 2 μm; the second stage is a temperature of 280°C, the pressure in the entire area is increased to 15 MPa, and maintained for 30 minutes; The surface of the reinforced pre-assembled plate is flattened using mechanical polishing equipment to obtain the formed circuit board, wherein the polishing liquid is an acidic suspension containing aluminum oxide particles.

7. The method for laminating a high thermal conductivity circuit board according to claim 1, wherein: The step of performing surface spraying and deposition treatment on the molded circuit board to obtain the high thermal conductivity circuit board includes: The aqueous solution containing zinc oxide nanorods and microcapsules is evenly coated on the surface of the molded circuit board by ultrasonic spraying technology, the spraying pressure is 0.2 MPa, the coating thickness is controlled to be 15 μm, and thermally cured at 90° C. for 20 minutes to obtain a primary coating substrate; Placing the primary coating substrate in an atomic layer deposition device, using titanium tetrachloride and ammonia as precursors, and depositing a titanium nitride protective film under vacuum conditions to obtain a protective layer substrate; The protective layer substrate was placed in an annealing furnace in a nitrogen atmosphere, heated to 300° C. at a heating rate of 5° C. / min, maintained for 30 minutes, and then cooled to room temperature at a cooling rate of 3° C. / min to obtain the high thermal conductivity circuit board.

8. A high thermal conductivity circuit board, characterized in that: The high thermal conductivity circuit board is manufactured by the pressing method for manufacturing the high thermal conductivity circuit board according to any one of claims 1 to 7.

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