Diamond / copper composite material preparation process parameter optimization method based on COMSOL multi-physics field simulation

Abstract

The invention discloses a diamond / copper composite material preparation process parameter optimization method based on COMSOL multi-physics field simulation, and the method specifically comprises the steps: obtaining the interface thermal conductivity h of each interface of a material according to an AMM model, and introducing a correction coefficient to correct the interface thermal conductivity of each interface; representing interface defects by taking the corrected interface thermal conductivity as interface contact thermal conductivity, and constructing a non-ideal interface thermal resistance model; a COMSOL coupling heat conduction equation and a thermal stress equation are utilized, the heat conductivity and the thermal expansion coefficient covering the diamond particle size, the TiC transition layer thickness and the copper base volume fraction are established and calculated, data analysis is conducted on a simulation result, and an optimized parameter interval is obtained. By means of the method, the optimization interval of the diamond particle size, the volume fraction and the interface carbonization layer thickness in the diamond / copper composite material preparation technology can be rapidly obtained, the research and development period is shortened, and convenience is provided for industrial production.

Description

Technical Field

[0001] This invention relates to the field of diamond / copper composite materials technology, and specifically to a method for optimizing the process parameters of diamond / copper composite material preparation based on COMSOL multiphysics simulation. Background Technology

[0002] In recent years, with the advancement of microelectronics and third-generation semiconductor technologies, modern electronic devices have gradually developed towards high integration, multi-functionality, and high power. The continuous improvement in the computing speed and integration of components such as chips has directly led to a sharp increase in the heat generated by these devices, with chip-level heat flux density exceeding 1 kW / cm². 2 The heat generated directly affects the operational stability, safety, reliability, and lifespan of electronic devices. Studies show that for every 10°C increase in temperature, the reliability of electronic devices decreases by 50%. Heat dissipation has become a bottleneck for the development of core technology industries in my country, particularly in the fields of electronic information and communication. However, the key to solving the heat dissipation problem lies primarily in the development of advanced thermal management materials and their advanced preparation technologies. This necessitates that thermal management materials possess ultra-high thermal conductivity, low coefficient of thermal expansion, and lightweight properties. Diamond, with its excellent thermophysical properties, is an ideal heat dissipation enhancer. However, single diamond is difficult to directly integrate into electronic packaging systems, while copper substrates, due to their high conductivity and processing compatibility, are the preferred carrier. Heat dissipation materials prepared by combining diamond and copper can theoretically achieve a thermal conductivity exceeding 600 W / (m·K), while simultaneously matching the coefficient of thermal expansion of semiconductor materials. Therefore, diamond / copper composite materials are considered a breakthrough for next-generation thermal management materials.

[0003] Currently, the conventional method for preparing diamond / copper composites is as follows: using high-purity diamond particles and copper powder with a transition layer as raw materials, the diamond particles and copper powder with the transition layer are first mechanically mixed (using an agate mortar and pestle or a planetary ball mill to achieve uniform dispersion), dried, and then molded into a sheet-like preform; subsequently, impurities are removed through vacuum high-temperature purification, and a staged temperature-controlled baking process is used to achieve material pre-sintering and structural stabilization; after assembling the preform with a pyrophyllite mold, it is synthesized and densified under high temperature and high pressure conditions; finally, the diamond / copper composite is obtained through pressure-controlled cooling and cavity opening. In the above preparation method, parameters such as the particle size and volume fraction of diamond, as well as the thickness of the interfacial carbide layer, have a direct impact on the performance of the diamond / copper composite. Traditional methods use a "trial and error" approach to optimize these parameters, but traditional experiments require trial and error one by one, and each process verification (from mixing to sintering to performance testing) is too time-consuming and costly.

[0004] Furthermore, the interfacial compatibility of diamond and copper is a known core challenge limiting their performance. On the one hand, the high surface tension of copper results in a wetting angle exceeding 120° on the diamond surface, easily leading to the formation of nanoscale air gaps at the interface. On the other hand, diamond primarily relies on phonon heat transfer, while copper depends on electron heat transfer; when the two are coupled, the interfacial thermal resistance increases significantly, and experimentally measured thermal conductivity of the composite material is generally more than 40% lower than the theoretical value. The actual diamond / copper composite interface exhibits complex conditions, such as interface roughness, impurities, and microstructural defects. These factors affect phonon transmission, causing discrepancies between theoretical and actual values.

[0005] Through experiments, the applicant discovered that by using COMSOL in conjunction with the Acoustic Mismatch Model (AMM) based on phonon transport theory to calculate interfacial thermal conductivity, introducing correction coefficients, and using the corrected interfacial thermal conductivity as the interfacial contact thermal conductivity to characterize interfacial defects, factors that are difficult to accurately represent in the model can be comprehensively considered. This makes the calculation results more consistent with the real interfacial thermal conductivity, improves the model's accuracy in describing the actual situation, and thus quickly obtains the optimized diamond particle size, volume fraction, and interfacial carbonization layer thickness. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation. This method can quickly obtain the optimization range of the preparation process parameters of composite materials (including diamond particle size and its doping ratio, titanium carbide layer thickness), shorten the research and development cycle, and form a full-chain design system of "performance-oriented - parameter prediction - process mapping", which provides convenience for industrial production.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A method for optimizing the process parameters of diamond / copper composite material preparation based on COMSOL multiphysics simulation includes the following steps:

[0009] S1. Obtain the interfacial thermal conductivity h of each interface of the diamond / copper composite material based on the acoustic mismatch model, including the thermal conductivity h of the diamond-TiC interface. Dia-TiC Thermal conductivity h at the TiC-copper interface TiC-Cu ;

[0010] S2. Set a correction coefficient δ to correct the interfacial thermal conductivity of each of the above interfaces. The product of the correction coefficient and the interfacial thermal conductivity obtained through the acoustic mismatch model is taken as the corrected interfacial thermal conductivity h. eff Including the corrected thermal conductivity h of the diamond-TiC interface eff(Dia-TiC) And the corrected TiC-copper interface thermal conductivity heff(TiC-Cu) ;

[0011] S3. Create a 3D model of diamond / copper, including a finite element model of diamond particles, titanium carbide layer and copper matrix;

[0012] S4. Define the material property parameters of the diamond particles, titanium carbide layer and copper matrix according to the data in the material database, and define the preparation process parameters of diamond / copper composite material;

[0013] S5. Using the created 3D diamond / copper model and defined material property parameters and fabrication process parameters, COMSOL Multiphysics was used to construct solid heat transfer and solid mechanics modules respectively and to perform simulations. The simulation results under different fabrication process parameters were analyzed to obtain the simulation results; among them,

[0014] When simulating the solid heat transfer module, contact thermal conductivity is added between the interfaces to characterize the influence of interface defects, and the modified interface thermal conductivity h mentioned above is used. eff As a contact thermal conductivity;

[0015] S6. Analyze the simulation results under different preparation process parameters to obtain optimized preparation process parameters.

[0016] In this application, the preparation process parameters of the diamond / copper composite material include the diamond particle size, the diamond volume fraction, and the thickness of the titanium carbide layer on the diamond surface.

[0017] After reviewing a large amount of information and conducting experimental verification, the inventors of this application set the correction coefficient δ in step S2 to 0.02.

[0018] In step S3, a 3D model of diamond / copper is created in COMSOL Multiphysics.

[0019] In step S4, the material property parameters of the diamond particles, titanium carbide layer, and copper matrix include at least their thermal conductivity, and further include density, constant pressure heat capacity, coefficient of thermal expansion, thermal strain, Young's modulus, Poisson's ratio, etc. The material property parameters of the diamond particles, titanium carbide layer, and copper matrix can be selected from the default values ​​in the material database, or they can be set manually according to the actual production situation.

[0020] Furthermore, in step S5, when simulating the solid heat transfer module, it is necessary to set the boundary conditions, which include:

[0021] (1) Define a boundary heat source on one side of the three-dimensional model;

[0022] (2) Define the opposite side of the boundary heat source as heat flux to make it convection with the air;

[0023] (3) Set the remaining boundaries of the model as adiabatic boundaries;

[0024] (4) Contact thermal conductivity was added between the diamond-titanium carbide layers and between the titanium carbide layer and the copper layer to characterize the influence of interface defects. h was used. eff(Dia-TiC) As the contact thermal conductivity between the diamond-titanium carbide layers, h was used eff(TiC-Cu) As the contact thermal conductivity between the titanium carbide layer and copper.

[0025] In step S5, the simulation results obtained when simulating the solid heat transfer module include relevant data such as the heat flux and temperature gradient required to calculate the thermal conductivity.

[0026] In step S5, when simulating the solid mechanics module, the boundary conditions include defining one face of the three-dimensional model as a fixed constraint. The simulation results obtained from simulating the solid mechanics module include data such as the length change required to calculate the coefficient of thermal expansion.

[0027] Compared with the prior art, the present invention is characterized by:

[0028] 1. By introducing the interface thermal conductivity corrected by the correction coefficient into the COMSOL multiphysics model as the interface contact thermal conductivity to characterize interface defects, the calculation results are more consistent with the real interface thermal conductivity. On the other hand, the feasible range of each preparation process parameter is pre-screened through the COMSOL multiphysics model to quickly find the optimized diamond particle size and its doping ratio, and the titanium carbide layer thickness.

[0029] 2. Using simulation to replace multi-parameter experimental processes results in shorter time and lower trial-and-error costs. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the method described in this invention.

[0031] Figure 2 A schematic diagram of the finite element 3D model of diamond / titanium carbide / copper created.

[0032] Figure 3 This is a graph showing the variation of thermal conductivity of diamond / copper composite material with diamond particle size based on COMSOL simulation of the present invention.

[0033] Figure 4 This is a graph showing the change in thermal conductivity of diamond / copper composite material with diamond volume fraction based on COMSOL simulation of the present invention.

[0034] Figure 5This is a graph showing the variation of thermal conductivity of diamond / copper composite material with titanium carbide layer thickness based on COMSOL simulation of the present invention. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. Indeed, those skilled in the art will recognize that modifications and variations can be made to the invention without departing from its scope or spirit. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the invention encompass such modifications and variations falling within the scope of the appended claims and their equivalents.

[0036] refer to Figure 1 This invention provides a method for optimizing the process parameters of diamond / copper composite material preparation based on COMSOL multiphysics simulation, specifically including the following steps:

[0037] First, following step S1, the interfacial thermal conductivity is calculated using the phonon mismatch model. The calculation of the interfacial thermal conductivity according to the phonon mismatch model is shown in the following formula:

[0038]

[0039] Where h is the interfacial thermal conductivity (W / m). 2 ·k); c m Specific heat capacity (J / (Kg·K)); ρ m —Density (m / s); ν m —Debye speed of sound (m / s); η —Probability of heat transfer from received phonons, the expression for the probability of receiving phonons η is as follows:

[0040]

[0041] Where η is the probability of receiving phonon heat transfer; ρ in —Ponton emission density (Kg / m3); ρ tran —Ponon receiver density (Kg / m3); ν in —Phonons emit sound at the speed of Fangdebai (m / s); ν tran —The Debye velocity of sound at the phonon receiver (m / s), calculated according to Debye's theory of heat conduction, is given by the following formula:

[0042]

[0043] Wherein, ν is the Debye speed of sound in the medium (m / s); νι is the longitudinal speed of sound in the medium (m / s); and νt is the transverse speed of sound in the medium (m / s).

[0044] The relevant parameters of the diamond particles, the titanium carbide layer on the surface of the diamond particles, and the copper substrate are shown in Table 1 below.

[0045] Table 1:

[0046]

[0047] The interfacial thermal conductivity was calculated using formulas (1), (2), and (3), and the results are as follows:

[0048] Diamond-titanium carbide interface thermal conductivity h Dia-TiC for:

[0049] h Dia-TiC =2.67×10 8 W / m 2 ·K

[0050] The thermal conductivity h of the titanium carbide-copper interface TiC-Cu for:

[0051] h TiC-Cu =5.62×10 8 W / m 2 ·K

[0052] Next, proceed to step S2. Because the interface bonding is not tight enough and porosity exists, a correction coefficient δ is added to the interface thermal conductivity. Here, δ = 0.02 is set, and the product of the correction coefficient and the interface thermal conductivity obtained through the acoustic mismatch model is used as the corrected interface thermal conductivity h. eff The calculation formula is as follows:

[0053] h eff =0.02h

[0054] Corrected thermal conductivity h of diamond-TiC interface eff(Dia-TiC) for:

[0055] h eff(Dia-TiC) =5.34×10 6 W / m 2 ·K

[0056] Corrected TiC-copper interface thermal conductivity h eff(TiC-Cu) for:

[0057] h eff(TiC-Cu) =11.24×10 6 W / m 2 ·K

[0058] Then, refer to Figure 2 , Figure 2This is a schematic diagram for creating a finite element 3D model of diamond / titanium carbide / copper. Following step S3, a 3D model of diamond particles is created in COMSOL Multiphysics, a titanium carbide layer is created on the diamond surface, and a copper substrate is created to coat it.

[0059] Next, following step S4, the material properties of diamond, titanium carbide layer, and copper matrix are defined based on the data in the material database. The material property parameters include their thermal conductivity, density, constant pressure heat capacity, coefficient of thermal expansion, thermal strain, Young's modulus, and Poisson's ratio. Specifically, the thermal conductivity of diamond is set to 1600 W / m·K, the thermal conductivity of titanium carbide layer is set to 36.4 W / m·K, and the thermal conductivity of copper is set to 385 W / m·K. Other property parameters are the default values ​​in the material database of COMSOL Multiphysics.

[0060] The preparation process parameters for diamond / copper composite materials include the diamond particle size, the diamond volume fraction, and the thickness of the titanium carbide layer on the diamond surface.

[0061] Next, according to step S5, solid heat transfer module and solid mechanics module are constructed in COMSOL Multiphysics and simulation is performed. The simulation results under different preparation process parameters are analyzed to obtain simulation results.

[0062] Because diamond / copper composite materials have good thermal conductivity, the time required to reach thermal equilibrium at the microscopic level is extremely short. Studying only a portion of this process could easily introduce significant errors. Therefore, to ensure the accuracy of physical quantity simulations, a steady-state simulation model is chosen.

[0063] S51. By constructing a solid heat transfer module and setting up multiphysics simulations, simulation results are obtained, including the heat flux and temperature gradient required to calculate thermal conductivity. The boundary conditions of the solid heat transfer module include:

[0064] (1) Define a boundary heat source on one side of the three-dimensional model;

[0065] (2) Define the opposite side of the boundary heat source as heat flux to make it convection with the air;

[0066] (3) Set the remaining boundaries of the model as adiabatic boundaries;

[0067] (4) To ensure the convergence of the finite element simulation model and simplify the calculation, contact thermal conductivity was added between the diamond-titanium carbide layer and between the titanium carbide layer and the copper layer to characterize the influence of interface defects. h was used. eff(Dia-TiC) =5.43×10 6 W / m 2K is the contact thermal conductivity between the diamond-titanium carbide layers, and h is used as the reference value. eff(TiC-Cu) =11.24×10 6 W / m 2 K represents the contact thermal conductivity between the titanium carbide layer and copper.

[0068] Steady-state simulations were performed on diamonds with different surface carbide layer thicknesses, diamond volume fractions, and diamond particle sizes. The simulation results were analyzed, and the heat flux and temperature gradient were calculated using the derived value function.

[0069] S52. By constructing a solid mechanics module and setting up multiphysics simulations, simulation results are obtained, including data such as the length change required to calculate the coefficient of thermal expansion. The boundary conditions of the solid mechanics module include defining one face of the three-dimensional model as a fixed constraint.

[0070] When simulating the coefficient of thermal expansion in the solid mechanics module, a reference temperature of 20℃ is set, and the coefficient of thermal expansion at a temperature increased by 100℃ is calculated. Assume the object's length is L when unheated, and that its length increases by ΔL after heating, with a temperature change of ΔT.

[0071] S6. Analyze the simulation results under different preparation process parameters to obtain optimized preparation process parameters.

[0072] S61. Calculate the corresponding thermal conductivity based on the heat flux and temperature gradient obtained under different preparation process parameters, specifically using Fourier's law of heat conduction to calculate the material's thermal conductivity:

[0073]

[0074] Where q represents heat flux density (W / m³) 2 ), representing the direction and magnitude of heat transfer per unit area per unit time; k represents the thermal conductivity of the material (W / (m·K), a physical quantity characterizing the material's thermal conductivity. dT / dx represents the temperature gradient (K / m), with a negative sign indicating that heat flows from the high-temperature region to the low-temperature region.

[0075] Based on the relationship curves between different preparation process parameters and their corresponding thermal conductivity, the following can be obtained:

[0076] (1) The transformation curve of diamond particle size and thermal conductivity is based on the premise that the diamond volume fraction is 60% and the titanium carbide layer thickness is 100nm.

[0077] (2) The transformation curve of diamond volume fraction and thermal conductivity, based on a diamond particle size of 200 μm and a titanium carbide layer thickness of 100 nm.

[0078] (3) The curve of the change between the thickness of the titanium carbide layer and the thermal conductivity is based on a diamond particle size of 200 μm and a diamond volume fraction of 60%.

[0079] S62. Calculate the corresponding coefficient of thermal expansion based on the length change obtained under different preparation process parameters. The calculation formula is as follows:

[0080]

[0081] Where α represents the coefficient of thermal expansion (1 / K), L represents the length (m) of the heat-flowing object (diamond / copper composite material) in the unheated state, ΔL represents the increase in length of the object after heating relative to before heating, and ΔT represents the temperature change.

[0082] Based on the relationship curves between different preparation process parameters and their corresponding coefficients of thermal expansion, the following can be obtained:

[0083] (1) The transformation curve of diamond particle size and thermal expansion coefficient is based on the premise that the diamond volume fraction is 60% and the titanium carbide layer thickness is 100nm.

[0084] (2) The transformation curve of diamond volume fraction and thermal expansion coefficient, based on diamond particle size of 200 μm and titanium carbide layer thickness of 100 nm.

[0085] (3) The curve of the transformation between the thickness of the titanium carbide layer and the coefficient of thermal expansion, based on a diamond particle size of 200 μm and a diamond volume fraction of 60%.

[0086] Based on the relationship curves obtained above under different preparation process parameters, the optimization range of each preparation process parameter can be quickly determined.

[0087] Furthermore, after determining the optimal range of the preparation process parameters, diamond / copper composite materials can be prepared according to conventional processes based on this optimal range. The actual properties (thermal conductivity, coefficient of thermal expansion) of the prepared materials can be tested, and the optimal preparation process parameters can be determined based on the test results.

[0088] The above optimization method defines material properties by establishing a finite element model of diamond / copper composite material, and combines the finite element model with the phonon mismatch model to obtain the parameters corresponding to the optimal thermal conductivity and thermal expansion coefficient. This greatly improves work efficiency, saves manpower and material resources, reduces experimental costs, and allows for rapid and multiple adjustments to the parameters of the composite material for optimization simulation, providing theoretical guidance for actual diamond / copper composite materials.

[0089] It should be noted that the above method is based on software implementation. The material database in the software contains data on the material properties required in the simulation experiment. The software has the required parameter data for thermal conductivity and coefficient of thermal expansion, and the material properties can be called when needed.

[0090] The conventional process for preparing diamond / copper composite materials mentioned above is as follows:

[0091] 1) Select diamond particles and copper powder. The diamond particles are 50 μm in diameter (TiC is introduced by magnetron sputtering) and have a purity of over 99%. The copper powder particles are 50 μm in diameter and have a purity of over 99%.

[0092] 2) Based on the mechanical mixing of diamond particles with a transition layer (i.e. TiC) on the surface, according to different powder ratios, the powder is weighed and placed in an agate mortar, anhydrous ethanol is added and repeatedly ground until the mixture is uniform, and then dried to obtain the mixture.

[0093] 3) Pour the mixture into a graphite / metal mold, level and compact it, and then use a tablet press to press it into a compact tablet shape (approximately Φ30mm×6mm, 80mm cylinder diameter tablet press, pressure set to 20MPa, hold pressure for 4-5 seconds and then remove).

[0094] 4) Place the molded and cold-pressed powder sheet into a vacuum furnace, evacuate the furnace chamber to a vacuum state, heat it to 600-800℃, and perform constant temperature purification treatment for 2 hours.

[0095] 5) Inspect the shape and size of the pyrophyllite and check for any missing edges or corners. Place the qualified pyrophyllite into the oven for baking at 500℃ for 4 hours to ensure that the moisture is dried.

[0096] 6) Assemble the composite sheet and pyrophyllite according to the size and press synthesis requirements.

[0097] 7) Synthesized under high temperature and high pressure, the temperature of the top hammer is controlled by a constant temperature circulating water tank during the synthesis process. Temperature measuring devices for the top hammer and the cavity are also provided. The temperature of the top hammer is kept constant by controlling the water temperature and water flow. At the same time, the synthesis power is adjusted by measuring the cavity temperature to ensure stable synthesis conditions. The synthesis process is as follows: temperature 1000~1350℃, pressure 5~7Gpa, holding time 8~12min, to obtain diamond / copper composite material.

[0098] 8) Perform machining processes such as outer circle, plane, and chamfer according to experimental testing requirements.

[0099] The preparation of diamond / copper composite materials is illustrated below with an example:

[0100] Example 1:

[0101] The powder ratio is as follows: copper powder and titanium-plated diamond account for 40% and 60% by volume, respectively. The titanium-plated diamond particle size is 50-300μm and the titanium layer thickness is 100nm.

[0102] In a Comsol simulation, the diamond volume fraction was set to 60%, the titanium carbide layer thickness to 100 nm, and the diamond particle size was varied within the range of 50–300 μm with a gradient of 50 μm. The effect of diamond particle size on the thermal conductivity and coefficient of thermal expansion of the composite material was simulated. The results are as follows: Figure 3 As shown.

[0103] As shown in the figure, both thermal conductivity and coefficient of thermal expansion increase with the increase of diamond particle size. When the diamond particle size is 150-200μm, the thermal conductivity is already relatively high. Considering the production cost, it is more reasonable to choose diamonds with a particle size of 150-200μm.

[0104] Example 2:

[0105] The powder formulation is as follows: the titanium-plated diamond particle size is 200μm, the titanium layer thickness is 100nm, and the volume fraction ratio of titanium-plated diamond to copper powder in the diamond / copper composite material is 10-70%: 90-30%.

[0106] In a Comsol simulation, with a diamond particle size of 200 μm and a titanium carbide layer thickness of 100 nm, the effect of diamond volume fraction (10–70%) on the thermal conductivity and coefficient of thermal expansion of the composite material was obtained. The results are as follows: Figure 4 As shown.

[0107] As shown in the figure, with the increase of diamond volume fraction, the thermal conductivity increases and the coefficient of thermal expansion decreases; the coefficient of thermal expansion of electronic packaging materials must match that of semiconductor chips, and the value is within 4 × 10⁻⁶. -6 K -1 ~9×10 -6 K -1 Within this range, the volume fraction of diamond should therefore be at least greater than 45%.

[0108] Example 3:

[0109] The powder ratio is as follows: copper powder and titanium-plated diamond account for 40% and 60% by volume, respectively. The titanium-plated diamond particle size is 200μm and the titanium plating layer thickness is 50-500nm.

[0110] In a Comsol simulation, with a diamond particle size of 200 μm and a diamond volume fraction of 60%, and the coating thickness varied within the range of 0–500 nm, the changes in thermal conductivity and coefficient of thermal expansion of the diamond / titanium carbide / copper composite material with the thickness of the titanium carbide layer were obtained. Figure 5 As shown.

[0111] Depend on Figure 5 It can be seen that as the thickness of the titanium carbide layer increases, the thermal conductivity and coefficient of thermal expansion decrease. The thermal conductivity of the coating has a significant impact on the overall thermal conductivity, but its effect on reducing the coefficient of thermal expansion is not obvious. Considering the good bonding between titanium carbide and diamond, a titanium carbide layer thickness of 150–200 nm is more reasonable.

Claims

1. A method for optimizing the process parameters of diamond / copper composite material preparation based on COMSOL multiphysics simulation, including the following steps: S1. Obtain the interfacial thermal conductivity h of each interface of the diamond / copper composite material based on the acoustic mismatch model, including the thermal conductivity h of the diamond-TiC interface. Dia-TiC Thermal conductivity h at the TiC-copper interface TiC-Cu ; S2. Set a correction coefficient δ to correct the interfacial thermal conductivity of each of the above interfaces. The product of the correction coefficient and the interfacial thermal conductivity obtained through the acoustic mismatch model is taken as the corrected interfacial thermal conductivity h. eff Including the corrected thermal conductivity h of the diamond-TiC interface eff(Dia-TiC) And the corrected TiC-copper interface thermal conductivity h eff(TiC-Cu) ; S3. Create a 3D model of diamond / copper, including a finite element model of diamond particles, titanium carbide layer and copper matrix; S4. Define the material property parameters of the diamond particles, titanium carbide layer and copper matrix according to the data in the material database, and define the preparation process parameters of diamond / copper composite material; S5. Using the created 3D diamond / copper model and defined material property parameters and fabrication process parameters, COMSOL Multiphysics was used to construct solid heat transfer and solid mechanics modules respectively and to perform simulations. The simulation results under different fabrication process parameters were analyzed to obtain the simulation results; among them, When simulating the solid heat transfer module, contact thermal conductivity is added between the interfaces to characterize the influence of interface defects, and the modified interface thermal conductivity h mentioned above is used. eff As a contact thermal conductivity; S6. Analyze the simulation results under different preparation process parameters to obtain optimized preparation process parameters.

2. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S2, the correction coefficient δ is set to 0.

02.

3. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S4, the material property parameters of the diamond particles, titanium carbide layer and copper matrix include at least their thermal conductivity.

4. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S4, the preparation process parameters of diamond / copper composite materials include the diamond particle size, the diamond volume fraction, and the thickness of the titanium carbide layer on the diamond surface.

5. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S5, when simulating the solid heat transfer module, the boundary conditions include: (1) Define a boundary heat source on one side of the three-dimensional model; (2) Define the opposite side of the boundary heat source as heat flux to make it convection with the air; (3) Set the remaining boundaries of the model as adiabatic boundaries; (4) Contact thermal conductivity was added between the diamond-titanium carbide layers and between the titanium carbide layer and the copper layer to characterize the influence of interface defects. h was used. eff(Dia-TiC) As the contact thermal conductivity between the diamond-titanium carbide layers, h was used eff(TiC-Cu) As the contact thermal conductivity between the titanium carbide layer and copper.

6. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S5, the simulation results obtained when simulating the solid heat transfer module include the heat flux and temperature gradient required to calculate the thermal conductivity.

7. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S5, when simulating the solid mechanics module, the boundary conditions include: Define one side of the 3D model as a fixed constraint.

8. The method for optimizing the preparation process parameters of diamond / copper composite materials based on COMSOL multiphysics simulation according to claim 1, characterized in that, in step S5, the simulation results obtained by simulating the solid mechanics module include the length change required to calculate the coefficient of thermal expansion.

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