Preparation method for three-dimensional interconnected graphene-diamond-reinforced copper-based composite material

Abstract

The present invention discloses a preparation method for a three-dimensional interconnected graphene-diamond-reinforced copper-based composite material, the method comprising the following specific steps: cleaning and drying the surface of porous copper having a three-dimensional structure; growing graphene on the surface of the porous copper in situ by means of chemical vapor deposition; applying plasma to the surface of the porous copper during the growth process to ensure that the growth direction of the graphene is parallel to the surface of the porous copper; filling the porous copper on which the graphene is grown with carbide-coated diamond particles to form a three-dimensional interconnected graphene-diamond-reinforced copper-based composite material preform; placing the preform into a hot isostatic press or a six-sided top press, applying pressure to the preform at a low temperature or room temperature and holding the pressure, subjecting the preform to hot press sintering, maintaining the temperature and holding the pressure, and then cooling same to obtain a three-dimensional interconnected graphene-diamond-reinforced copper-based composite material; and performing a heat treatment. The present invention can construct a continuous graphene network structure in a composite material, thereby alleviating the "island" effect and providing a highly thermally conductive channel for the composite material.

Description

Preparation method of three-dimensional interconnected graphene-diamond reinforced copper-based composite material TECHNICAL FIELD

[0001] The present application belongs to the technical field of composite materials, and particularly relates to a preparation method of a three-dimensional interconnected graphene-diamond reinforced copper-based composite material. BACKGROUND

[0002] With the development of integration technology and microelectronic packaging technology, the "high performance and high integration" of semiconductor devices and chips has led to a continuous increase in power density, and high thermal conductivity electronic packaging heat dissipation materials have become a guarantee for solving the high efficiency heat dissipation and reliability development of devices. Electronic packaging heat dissipation materials have experienced Invar and Kovar alloy, Cu / W and Cu / Mo alloy, and Al / SiC and Cu / Si metal matrix composite materials, etc. The thermal conductivity is less than 300 W / mK, and it is difficult to meet the heat dissipation requirements of high-power devices. In recent years, diamond / copper composite materials prepared by combining diamond particles with high thermal conductivity (1800-2000 W / mK) and low thermal expansion coefficient (1.0 ppm / K) as reinforcing bodies and copper matrix have become ideal packaging materials for microwave solid-state power amplifiers in modern satellite communication, radar and electronic warfare fields due to their high thermal conductivity and flexible control of thermal expansion coefficient.

[0003] Diamond / copper composite materials are a research hotspot of new generation electronic packaging materials, but the current main research ideas at home and abroad are alloy matrix and diamond particle surface modification to improve the interface between diamond particles and copper. Although good results have been achieved, however, it is difficult to form a connected heat conduction channel in this composite structure due to the presence of copper matrix between diamond particles. There are not only a large number of interfaces between the two phases, but also it is difficult to produce a synergistic effect, making it difficult for diamond to fully exert its excellent thermal conductivity. Patent CN109825815B proposes a preparation method for reducing the interface thermal resistance of diamond / copper thermal conduction composite material, in which graphene is grown in situ on the surface of diamond particles to reduce the interface thermal resistance, but it is difficult to form a three-dimensional interconnected structure to eliminate the influence of interface thermal resistance and make the two phases produce a synergistic effect. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art, and to provide a preparation method of a three-dimensional interconnected graphene-diamond reinforced copper-based composite material, which constructs a continuous graphene network structure in the composite material and breaks the "island" effect to provide a high thermal conductivity channel for the composite material.

[0005] To achieve the above technical purpose, the technical scheme adopted by the present application is as follows:

[0006] A preparation method of a three-dimensional interconnected graphene-diamond reinforced copper-based composite material, comprising the following specific steps:

[0007] Step one, surface cleaning and drying of the three-dimensional porous copper, in-situ growth of graphene on the surface of the porous copper by chemical vapor deposition, and application of plasma to the surface of the porous copper during the growth of graphene to make the growth direction of the graphene parallel to the surface of the porous copper;

[0008] Step two, filling of carbide-coated diamond particles in the graphene-grown porous copper to form a three-dimensional interconnected graphene-diamond reinforced copper-based composite material preform;

[0009] Step three, placing the composite material preform in a hot isostatic press or a six-surface press, first applying and pressing the preform at low temperature or room temperature, then heat pressing and sintering the preform, and after temperature and pressure preservation, cooling to obtain a three-dimensional interconnected graphene-diamond reinforced copper-based composite material;

[0010] Step four, heat treatment of the three-dimensional interconnected graphene-diamond reinforced copper-based composite material to complete the preparation.

[0011] To optimize the above technical solution, the specific measures taken also include:

[0012] In the above step one, the pore size of the porous copper is 10 μm to 10 mm, and the porosity is 40 to 90%.

[0013] In the above step one, the parameters of the chemical vapor deposition are as follows: the mass flow percentage of the carbon-containing gas in the total gas in the furnace is 5-70%.

[0014] In the above step one, the growth temperature of the growth process is 800-1200℃, the growth gas pressure is 10 3 -10 5 Pa, and the plasma current density is 10-40 mA / cm 2 .

[0015] In the above step two, the particle size of the diamond particles is 50-900 μm, and the size of the diamond particles is always smaller than the pore size of the graphene-grown porous copper.

[0016] In the above step two, the carbide is WC, MoC, Cr7C3, TiC, B4C, SiC, ZrC, NbC and VC.

[0017] In the above step three, if a hot isostatic press is used to apply and press the preform, the applied pressure is 100-150 MPa, the temperature rising rate is 5-15 min / ℃, the pressure preservation time is 0.5-24 h, and the temperature is 20-500℃.

[0018] If the preform is subjected to the application and pressure maintaining by the cubic press, the application pressure is 2-4 GPa, the pressure maintaining time is 0.5-24 h, and the temperature is 20-500 DEG C.

[0019] In the step three, the sintering temperature of the hot-press sintering is 800-1100 DEG C, the sintering pressure is 100-200 MPa when the hot isostatic press is used, the sintering pressure is 4-8 GPa when the cubic press is used, and the pressure maintaining time after the hot-press sintering is 10-30 min.

[0020] In the step four, the temperature of the heat treatment is 200-400 DEG C, and the time is 10-120 min.

[0021] The present application has the following beneficial effects:

[0022] 1. Firstly, the present application utilizes the chemical vapor deposition method to grow graphene on the surface of the porous copper matrix in the transverse direction, and then combines with the diamond particles, fills the diamond particles in the porous copper of the grown graphene, and forms a composite preform, which uses graphene as a "link" to connect the diamond particles and the copper matrix in three dimensions, forms a three-dimensional interconnected heat conduction channel, weakens the interfacial thermal resistance between the two phases, and plays a synergistic effect, thereby greatly improving the thermal conductivity of the diamond / copper composite material.

[0023] 2. The present application is different from the pressure infiltration method for preparing the diamond / copper composite material, and utilizes the hot isostatic press / cubic press to perform low-temperature pressurization and high-temperature sintering on the preform to form a graphene-diamond reinforced copper-based composite material, which is prepared below the melting point of copper, effectively avoids the damage of the molten copper liquid to the three-dimensional interconnected graphene structure, maintains the connectivity of the reinforcing phase and the matrix in three-dimensional space, greatly weakens the influence of the composite interface on the thermal performance of the material, and makes the composite material have excellent continuous heat conduction capacity, thereby fundamentally solving the problem that the thermal conductivity of the composite material is difficult to further improve.

[0024] 3. Finally, the present application performs heat treatment on the composite material, which can eliminate the interfacial thermal stress and obtain a graphene-diamond reinforced copper-based composite material with high thermal conductivity.

[0025] 4. The present application is simple to operate, has strong implementability, is suitable for large-scale production, and is beneficial to improve the production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is a flow chart of the method of the present application;

[0027] Fig. 2 is a principle diagram of the method of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0029] The steps in the present application are arranged by using labels, but are not used to limit the sequence of the steps, unless the sequence of the steps is explicitly described or the execution of a certain step needs other steps as a basis, otherwise the relative sequence of the steps can be adjusted. It can be understood that the term "and / or" used herein relates to and covers any and all possible combinations of one or more of the associated listed items.

[0030] As shown in Figures 1-2, a method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material of the present application comprises the following specific steps:

[0031] Step one, surface cleaning and drying of the porous copper, in-situ growth of graphene of a certain thickness on the surface of the porous copper by using chemical vapor deposition, and applying plasma to the surface of the graphene during the growth of the graphene to make the growth direction of the graphene parallel to the surface of the porous copper;

[0032] Step two, filling the porous copper with graphene grown in step one with carbide-coated diamond particles smaller than the pore size of the porous copper to form a three-dimensional interconnected graphene-diamond reinforced copper-based composite material preform;

[0033] Step three, placing the composite material preform in step two in a hot isostatic press / six-surface press, first applying pressure to the composite material at low temperature or room temperature and holding the pressure for a period of time to densify the preform, then heating the equipment to the sintering temperature, holding the temperature and pressure for a period of time, and then cooling to obtain a three-dimensional interconnected graphene-diamond reinforced copper-based composite material;

[0034] Step four, heat treatment of the three-dimensional interconnected graphene-diamond reinforced copper-based composite material prepared in step three.

[0035] In the examples, in step one, the pore size of the porous copper is 10 μm-10 mm, the porosity is 40-90%, and it is a three-dimensional structure.

[0036] The chemical vapor deposition parameters are as follows: the mass flow percentage of carbon-containing gas in the total gas in the furnace is 5-70%; the growth temperature is 800-1200℃, and the growth gas pressure is 10 3 -10 5 Pa;

[0037] The plasma current density is 10-40 mA / cm 2 .

[0038] In the embodiment, in step two, the particle size of the diamond is 50-900 μm, and the size of the diamond particle is always less than the diameter of the porous copper hole in which the graphene grows.

[0039] The carbide on the surface of the diamond is WC, MoC, Cr7C3, TiC, B4C, SiC, ZrC, NbC, and VC.

[0040] In the embodiment, in step three, the applied pressure of the hot isostatic press at low or room temperature is 100-150 MPa, the temperature rising rate is 5-15 min / ℃, the pressure holding time is 0.5-24 h, and the temperature is 20-500 ℃. The applied pressure of the cubic press at low or room temperature is 2-4 GPa, the pressure holding time is 0.5-24 h, and the temperature is 20-500 ℃.

[0041] The purpose of applying pressure to the composite material at low or room temperature for a period of time is to make the graphene contact the coated diamond to form a copper-graphene-carbide-diamond interface, and to densify the graphene-diamond reinforced copper matrix composite.

[0042] The sintering temperature of the composite material is 800-1100 ℃, the sintering pressure of the hot isostatic press is 100-200 MPa, the sintering pressure of the cubic press is 4-8 GPa, and the pressure holding time is 10-30 min.

[0043] In the embodiment, in step four, the heat treatment temperature of the composite material is 200-400 ℃, and the time is 10-120 min. The purpose of the heat treatment of the composite material is to eliminate the thermal stress of the interface and strengthen the interface bonding strength.

[0044] Embodiment 1

[0045] The embodiment includes the following steps:

[0046] Step one, the porous copper with a hole diameter of 100 μm and a porosity of 60% is surface cleaned and dried, and a deposition system with a carbon-containing gas mass flow percentage of 50% in the total gas in the furnace, a growth temperature of 800 ℃, and a growth gas pressure of 10 Pa is used to grow graphene with a thickness of 20 μm on the surface of the porous copper in situ. A plasma current density of 40 mA / cm2 is applied to the surface of the graphene during the growth of the graphene to make the growth direction of the graphene parallel to the surface of the porous copper. 5 Pa is used to grow graphene with a thickness of 20 μm on the surface of the porous copper in situ. A plasma current density of 40 mA / cm2 is applied to the surface of the graphene during the growth of the graphene to make the growth direction of the graphene parallel to the surface of the porous copper. 2

[0047] Step two, then fill the porous copper in which the graphene grows with titanium carbide-coated diamond particles with a hole diameter of 57 μm to form a three-dimensionally connected graphene-diamond reinforced copper matrix composite preform;

[0048] ​Step three, the above composite material preform is placed in a hot isostatic press, first a pressure of 2 GPa is applied to the composite material at room temperature and the preform is densified for 30 min, then the equipment is heated to 950℃, a pressure of 150 MPa is applied and held for 10 min, and then the temperature is lowered to room temperature, and the composite material is taken out;

[0049] Step four, the composite material is further heat treated at 200℃ for 20 min to obtain a three-dimensionally interconnected graphene-diamond reinforced copper-based composite material.

[0050] The thermal conductivity of the composite material prepared in this example is 836 W / mK.

[0051] Example 2

[0052] This example includes the following steps:

[0053] Step one, the porous copper with a pore diameter of 1000 μm and a porosity of 73% is surface cleaned and dried, and a graphene with a thickness of 20 μm is grown in situ on the surface of the porous copper by a chemical vapor deposition system with the following parameters: the mass flow percentage of carbon-containing gas in the total gas in the furnace is 60%; the growth temperature is 800℃, and the growth gas pressure is 10 5 Pa. A plasma current density of 30 mA / cm 2 is applied to the surface of the graphene during the growth process to promote the growth direction of the graphene to be parallel to the surface of the porous copper.

[0054] Step two, then the porous copper with graphene is filled with titanium carbide coated diamond particles with a pore diameter of 301 μm to form a three-dimensionally interconnected graphene-diamond reinforced copper-based composite material preform;

[0055] Step three, the above composite material preform is placed in a six-surface press, first a pressure of 3 GPa is applied to the composite material at room temperature and the preform is densified for 40 min, then the equipment is heated to 900℃, a pressure of 6 GPa is applied and held for 10 min, and then the temperature is lowered to room temperature, and the composite material is taken out;

[0056] Step four, the composite material is further heat treated at 350℃ for 10 min to obtain a three-dimensionally interconnected graphene-diamond reinforced copper-based composite material.

[0057] The thermal conductivity of the composite material prepared in this example is 747 W / mK.

[0058] Comparative Example 1

[0059] This comparative example includes the following steps:

[0060] The porous copper with a pore diameter of 100 μm and a porosity of 60% was surface cleaned and dried. The porous copper was then filled with titanium carbide-plated diamond particles with a pore size of 57 μm to form a three-dimensional interconnected graphene-diamond reinforced copper matrix composite preform.

[0061] The above-mentioned composite material preform was placed in a hot isostatic press. First, a pressure of 100 MPa was applied to the composite material at room temperature and held for 30 minutes to densify the preform. Then, the equipment was heated to 950°C, a pressure of 150 MPa was applied and held for 10 minutes, and then cooled to room temperature before the composite material was removed.

[0062] Further heat treatment of the composite material at 200℃ for 20 min yielded a three-dimensional interconnected graphene-diamond reinforced copper matrix composite material.

[0063] The thermal conductivity of the composite material prepared in this comparative example is 513 W / mK.

[0064] Example 3

[0065] This embodiment includes the following steps:

[0066] Step 1: Clean and dry the surface of porous copper with a hole diameter of 10 mm and a porosity of 40%. Use chemical vapor deposition parameters as follows: carbon-containing gas accounts for 42% of the total gas mass flow rate in the furnace; growth temperature is 1000℃; growth gas pressure is 10... 5 Pa's deposition system in situ grew 20 μm thick graphene on a porous copper surface, with a plasma current density of 20 mA / cm² applied to the graphene surface during growth. 2 The plasma caused the graphene to grow parallel to the porous copper surface.

[0067] Step 2: Then, fill the porous copper with graphene growth with titanium carbide-coated diamond particles with a pore size of 851μm to form a three-dimensional interconnected graphene-diamond reinforced copper matrix composite preform.

[0068] Step 3: Place the above composite material preform into a six-sided press. First, apply a pressure of 4 GPa to the composite material at room temperature and hold the pressure for 50 minutes to densify the preform. Then, heat the equipment to 1000°C, apply a pressure of 8 GPa and hold the pressure for 10 minutes, and then cool it to room temperature before taking out the composite material.

[0069] Step 4: Further heat-treat the composite material at 200℃ for 30 minutes to obtain a three-dimensional interconnected graphene-diamond reinforced copper matrix composite material.

[0070] The thermal conductivity of the composite material prepared in this embodiment is 689 W / mK.

[0071] Based on the above three examples and one comparative example, it can be seen that as the pressure applied to the preform and the holding time are increased, the densification of the preform is promoted, thereby improving the thermal conductivity of the composite material. However, when the pressure exceeds 2 GPa and the holding time exceeds 40 min, the thermal conductivity performance of the composite material tends to decrease, thus it is necessary to reasonably control the equipment pressure and holding time.

[0072] It is apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and this application can be carried out in other specific forms without departing from the spirit or essential characteristics of the application. Accordingly, no matter from which point of view, the examples should be considered as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and range of equivalents of the elements of the claims. Any reference signs in the claims should not be considered as limiting the claims involved.

[0073] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method of producing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material, characterized by, The method comprises the following specific steps: Step 1: surface cleaning and drying of the three-dimensional porous copper, in-situ growth of graphene on the surface of the porous copper by chemical vapor deposition, and application of plasma to the surface of the porous copper during the growth of the graphene to make the growth direction of the graphene parallel to the surface of the porous copper; Step 2: filling of carbide-diamond particles in the graphene-grown porous copper to form a three-dimensional interconnected graphene-diamond reinforced copper-based composite preform; Step 3: placing the composite preform in a six-surface press, first applying and pressure-keeping to the preform at a temperature of 20-500 DEG C, and then hot-pressing and sintering the preform, after temperature and pressure keeping, cooling to obtain a three-dimensional interconnected graphene-diamond reinforced copper-based composite, wherein the application pressure of the six-surface press to the preform is 2-4 GPa, and the pressure-keeping time is 0.5-24 h; Step 4: heat treatment of the three-dimensional interconnected graphene-diamond reinforced copper-based composite to complete the preparation.

2. The method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material according to claim 1, characterized in that, In step 1, the pore size of the porous copper is 10 μm-10 mm, and the porosity is 40-90%.

3. The method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material according to claim 1, characterized in that, In step 1, the parameters of the chemical vapor deposition are as follows: the mass flow percentage of the carbon-containing gas in the total gas in the furnace is 5-70%.

4. The method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material according to claim 1, characterized in that, The growth temperature of the growth process is 800-1200℃, and the growth pressure is 10 3 -10 5 Pa, and the plasma current density is 10-40 mA / cm 2 .

5. The method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material according to claim 1, characterized in that, In step 2, the particle size of the diamond particles is 50-900 μm, and the size of the diamond particles is always smaller than the pore size of the graphene-grown porous copper.

6. The method of claim 1, wherein the three-dimensional interconnected graphene-diamond reinforced copper matrix composite is prepared by the steps of: In step 2, the carbide is WC, MoC, Cr7C3, TiC, B4C, SiC, ZrC, NbC and VC.

7. The method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material according to claim 1, characterized in that, In step 3, the sintering temperature of the hot-pressing and sintering is 800-1100 DEG C, the sintering pressure when using the six-surface press is 4-8 GPa, and the pressure-keeping time after the hot-pressing and sintering is 10-30 min.

8. The method for preparing a three-dimensional interconnected graphene-diamond reinforced copper-based composite material according to claim 1, characterized in that, In step 4, the heat treatment temperature is 200-400 DEG C, and the time is 10-120 min.

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