A diamond copper-based composite material and a preparation method thereof

Abstract

The application belongs to the technical field of copper-based diamond composite materials, and particularly relates to a diamond copper-based composite material and a preparation method thereof. The preparation method comprises the following steps: mixing modified diamond powder and copper powder by ball milling, and obtaining a diamond copper core material after hot-pressing sintering; activating the diamond copper core material, then magnetron sputtering a Ni / Pr alloy target material onto the upper and lower surfaces of the activated diamond copper core material to form a Ni / Pr composite intermediate layer; vacuum welding copper sheets on the upper and lower surfaces of the Ni / Pr composite intermediate layer to obtain the diamond copper-based composite material. The diamond copper-based composite material prepared by the application has high density, excellent thermal conductivity, low thermal expansion coefficient and is convenient to process.

Description

A diamond-copper matrix composite material and its preparation method Technical Field

[0001] This invention belongs to the technical field of copper-based diamond composite materials, specifically relating to a diamond-copper composite material and its preparation method. Background Technology

[0002] Electronic packaging refers to the sealing and connection of integrated circuits to form an electronic system. It serves to create electrical interconnections with external circuit boards, protect and support integrated circuits and various electronic components, and provide heat dissipation channels for integrated circuits. With the rapid development of cutting-edge technologies such as 5G mobile communication, the Internet of Things, artificial intelligence, and power batteries, semiconductor devices are continuously evolving towards higher power and higher integration. Chip packaging density and heat generation per unit area are constantly increasing. Insufficient heat dissipation will lead to reduced reliability of the chip-substrate connection; that is, at high temperatures, the chip packaging substrate interconnect can easily fail. As the main path for chip heat dissipation, developing low-cost, low-thermal-expansion, high-thermal-conductivity, and high-reliability packaging heat sink materials has become an urgent task.

[0003] The two main performance characteristics of heat sink encapsulation materials are high thermal conductivity and a matched coefficient of thermal expansion. Diamond / copper composites, as the fourth generation of encapsulation materials, combine the high thermal conductivity and low coefficient of thermal expansion of diamond with the excellent processing properties of copper. They possess advantages such as high thermal conductivity and an adjustable coefficient of thermal expansion, making them highly competitive in the field of electronic packaging heat dissipation. However, the poor wettability between diamond and copper, along with their different thermal conduction mechanisms, easily leads to problems such as difficulty in diamond infiltration into copper, significant differences in density distribution, and insufficient airtightness. Furthermore, the high hardness of diamond makes processing difficult, limiting the application scenarios of diamond / copper composites. To obtain reliable diamond / copper composites, copper matrix alloying, diamond surface metallization, and other diamond surface treatment methods are commonly used to improve the interface of the composite material, thereby reducing interfacial thermal resistance and increasing the thermal conductivity of the composite. Summary of the Invention

[0004] The primary objective of this invention is to provide a method for preparing diamond-copper composite materials.

[0005] The second objective of this invention is to provide a diamond-copper composite material prepared by the above-described method, which has high density, excellent thermal conductivity, low coefficient of thermal expansion, and is easy to process.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a diamond-copper matrix composite material includes the following steps:

[0008] (1) Modified diamond powder and copper powder are ball-milled and mixed, and then hot-pressed and sintered to obtain diamond copper core material;

[0009] (2) The diamond copper core material is activated, and then the Ni / Pr alloy target is magnetron sputtered onto the upper and lower surfaces of the activated diamond copper core material to form a Ni / Pr composite intermediate layer.

[0010] (3) Vacuum weld copper sheets on the upper and lower surfaces of the Ni / Pr composite intermediate layer to obtain a diamond copper-based composite material.

[0011] Furthermore, the modified diamond powder described in step (1) is prepared by the following process:

[0012] (a) Cobalt layer is deposited on the surface of diamond particles by vacuum evaporation to obtain cobalt-coated diamond;

[0013] (b) The cobalt-plated diamond was placed in a mixture of silane and hydrogen gas and silanene was deposited under heating conditions to obtain modified diamond powder.

[0014] Further, the parameters for vacuum evaporation in step (a) are: vacuum degree of 10. -2 -10 -4 The concentration of metal vapor is 35-45% at Pa, the temperature is 720-760 ℃, and the plating time is 2-3 h; the particle size of the diamond particles is 70-120 μm; and the thickness of the cobalt layer is 0.3-0.6 μm.

[0015] Further, in step (b), the volume ratio of silane to hydrogen is 1:(1.5-2.5); the flow rate of the mixed gas is 10-15 sccm; the heating temperature is 600-700 ℃; the deposition time is 30-60 s; and the deposition thickness is 0.1-0.15 μm.

[0016] Further, in step (1), the volume ratio of modified diamond powder to copper powder is 1:(1-2.2); the pressure of hot pressing sintering is 40-50 MPa, the temperature is 900-1000 ℃, and the time is 10-15 min; the thickness of the diamond copper core material is 1-10 mm.

[0017] Further, the activation in step (2) is carried out in a hydrochloric acid solution with a mass fraction of 8-12% for 8-12 s; the parameters of the magnetron sputtering are: sputtering chamber pressure of 1-2 Pa, sputtering temperature of 120-200 ℃, and power density of 2000-4000 W / cm³. 2 The thickness of the Ni / Pr composite interlayer is 0.5-3 μm.

[0018] Further, the vacuum welding step described in step (3) is as follows: at a vacuum degree of 10... -3 -10-5 A pressure of 2-5 MPa is applied under Pa, and the temperature is maintained at 750-860 ℃ for 30-40 min; the thickness of the copper sheet is 0.2-0.3 mm.

[0019] Furthermore, the Ni / Pr alloy target material described in step (2) is prepared by the following process:

[0020] Ni and Pr raw materials are mixed evenly, melted in an inert gas atmosphere, cast, cooled and demolded to obtain Ni / Pr alloy ingots; Ni / Pr alloy ingots are hot forged, cold rolled and heat-held to obtain Ni / Pr alloy targets.

[0021] Further, the mass ratio of Ni to Pr is 1:(0.05-0.08); the hot forging temperature is 1000-1150℃; the heat preservation temperature is 800-850℃, and the time is 1-2 h.

[0022] A diamond-copper matrix composite material is prepared by the above-described method for preparing diamond-copper matrix composite materials.

[0023] The beneficial technical effects of this invention are as follows:

[0024] 1. This invention first sintersects modified diamond powder and copper powder to obtain a diamond-copper core material. Then, a Ni / Pr composite intermediate layer is prepared on the surface of the diamond-copper core material. Finally, copper is coated again on the surface of the Ni / Pr composite intermediate layer to obtain a diamond-copper matrix composite material. The product obtained using this process has high density, excellent thermal conductivity, good airtightness, and is easy to process.

[0025] 2. This invention improves the sintering performance between diamond and copper and enhances the material's density by modifying the diamond surface to establish a cobalt / silicene composite transition layer. Cobalt exhibits good wettability with diamond and can undergo interfacial reactions to form carbide phases such as Co3C, thus improving the sintering performance between diamond and copper. Cobalt can also act as a metal catalytic substrate to promote the deposition of silicene. Silicene has high chemical activity and a large specific surface area, which can reduce the surface energy of diamond and undergo diffusion reactions with copper, forming a liquid phase during sintering, promoting structural rearrangement, thereby improving sintering density and enhancing the overall performance of the composite material.

[0026] 3. This invention also prepares a Ni / Pr composite intermediate layer on the surface of the diamond copper core material, which can effectively improve the thermal conductivity of the diamond copper matrix composite material and adjust its coefficient of thermal expansion. Ni has good welding performance, and Pr has good interface activation and impurity adsorption effects. The Ni-Pr composite can purify the interface, reduce the porosity of the coating, and the doping of Pr can reduce the coefficient of thermal expansion of the coating, improve the bonding strength between the coating and the diamond copper core material, and form a dense and well-bonded coating on the core material surface. This can improve the thermal conductivity and welding performance of the diamond copper core material, which is beneficial for the welding of copper-diamond copper core material-copper, and improves the weld airtightness of the diamond copper matrix composite material.

[0027] 4. This invention employs a copper plating process on both the upper and lower surfaces of the Ni / Pr composite intermediate layer, effectively solving the problems of traditional diamond copper materials requiring additional nickel plating when welded to ceramic plates, and the tendency for the nickel plating layer to blister and peel off during 800°C brazing. Furthermore, the thickness of the surface copper layer can be flexibly adjusted according to different expansion coefficients, and bosses or grooves can be designed on the copper layer to further improve the processing performance of the composite material. Attached Figure Description

[0028] Figure 1 is the XRD pattern of the modified diamond powder prepared in Example 1 of this invention;

[0029] Figure 2 is a schematic diagram of the diamond copper-based composite material obtained in Example 1 of the present invention, wherein 1 is the diamond copper core material, 2 is the Ni / Pr composite intermediate layer, and 3 is the copper sheet. Detailed Implementation

[0030] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0031] (a) Preparation example

[0032] Preparation Example 1

[0033] Preparation Example 1 provides a modified diamond powder, which is prepared by the following method:

[0034] (a) Diamond particles with an average particle size of 100 μm were washed, dried, and a 0.5 μm cobalt layer was deposited on the diamond surface using a vacuum micro-evaporation deposition method to obtain cobalt-coated diamond; wherein the deposition process conditions were: vacuum degree of 10 -3 Pa, metal vapor concentration of 40%, temperature of 750 ℃, and plating time of 2 h.

[0035] (b) Place the cobalt-plated diamond into the reaction chamber, and introduce a mixture of silane and hydrogen at a flow rate of 12 sccm into the reaction chamber according to a volume ratio of silane to hydrogen of 1:2. Deposit at 650 °C for 40 s to allow silicon atoms to grow on the cobalt layer to form a silane with a thickness of 0.12 μm, thus obtaining modified diamond powder.

[0036] The XRD pattern of the modified diamond powder prepared in this preparation example is shown in Figure 1.

[0037] Preparation Example 2

[0038] Preparation Example 2 provides a modified diamond powder, prepared by the following method:

[0039] (a) Diamond particles with an average particle size of 70 μm were washed, dried, and a 0.3 μm cobalt layer was deposited on the diamond surface using a vacuum micro-evaporation deposition method to obtain cobalt-coated diamond; wherein the deposition process conditions were: vacuum degree of 10 -2 Under the conditions of Pa, metal vapor concentration of 35%, temperature of 720 ℃, and plating time of 2 h.

[0040] (b) Place the cobalt-plated diamond into the reaction chamber, and introduce a mixture of silane and hydrogen at a flow rate of 10 sccm into the reaction chamber at a volume ratio of 1:1.5. Deposit at 600 °C for 30 s to allow silicon atoms to grow on the cobalt layer to form a 0.1 μm thick silane, thus obtaining modified diamond powder.

[0041] Preparation Example 3

[0042] Preparation Example 3 provides a modified diamond powder, prepared by the following method:

[0043] (a) Diamond particles with an average particle size of 120 μm were washed, dried, and a 0.6 μm cobalt layer was deposited on the diamond surface using a vacuum micro-evaporation deposition method to obtain cobalt-coated diamond; wherein the deposition process conditions were: vacuum degree of 10 -4 Under the conditions of Pa, metal vapor concentration of 45%, temperature of 760 ℃, and plating time of 3 h.

[0044] (b) Place the cobalt-plated diamond into the reaction chamber, and introduce a mixture of silane and hydrogen at a flow rate of 15 sccm into the reaction chamber at a volume ratio of 1:2.5. Deposit at 700 °C for 60 s to allow silicon atoms to grow on the cobalt layer to form a 0.15 μm thick silane, thus obtaining modified diamond powder.

[0045] Preparation Example 4

[0046] Preparation Example 4 provides a modified diamond powder, which is basically the same as Preparation Example 1, except that step (b) in Preparation Example 1 is omitted.

[0047] Preparation Example 5

[0048] Preparation Example 5 provides a Ni / Pr alloy target material, which is prepared by the following method:

[0049] According to the mass ratio of Ni to Pr of 1:0.06, the Ni and Pr raw materials were purified and mixed evenly, then transferred to a melting furnace and melted under an argon atmosphere. After casting, cooling, and demolding, Ni / Pr alloy ingots were obtained. The Ni / Pr alloy ingots were hot forged at 1100 ℃, then cold rolled twice, and finally held at 820 ℃ for 1 h to obtain Ni / Pr alloy targets.

[0050] Preparation Example 6

[0051] Preparation Example 6 provides a Ni / Pr alloy target material, which is prepared by the following method:

[0052] According to the mass ratio of Ni to Pr of 1:0.05, the Ni and Pr raw materials were purified and mixed evenly, then transferred to a melting furnace and melted under an argon atmosphere. After casting, cooling, and demolding, Ni / Pr alloy ingots were obtained. The Ni / Pr alloy ingots were hot-forged at 1000 ℃, then cold-rolled once, and finally held at 800 ℃ for 1 h to obtain Ni / Pr alloy targets.

[0053] Preparation Example 7

[0054] Preparation Example 7 provides a Ni / Pr alloy target material, which is prepared by the following method:

[0055] According to the mass ratio of Ni to Pr of 1:0.08, the Ni and Pr raw materials were purified and mixed evenly, then transferred to a melting furnace and melted under an argon atmosphere. After casting, cooling, and demolding, Ni / Pr alloy ingots were obtained. The Ni / Pr alloy ingots were hot-forged at 1150 ℃, then cold-rolled 3 times, and finally held at 850 ℃ for 2 h to obtain Ni / Pr alloy targets.

[0056] Preparation Example 8

[0057] Preparation Example 8 provides a Ni target material, which is basically the same as Preparation Example 5, except that Pr is omitted in Preparation Example 5.

[0058] (II) Implementation Examples

[0059] Example 1

[0060] Example 1 provides a method for preparing a diamond-copper-based composite material, the specific steps of which are as follows:

[0061] (1) The modified diamond powder and copper powder prepared in Preparation Example 1 were ball-milled and mixed evenly according to a volume ratio of diamond powder to copper powder of 1:1.5. The mixture was then placed into a mold and subjected to a vacuum of 10. -2 Under the conditions of Pa and applied pressure of 45 MPa, the diamond copper core material with a thickness of 5 mm was obtained by sintering at 950 ℃ for 12 min and cooling.

[0062] (2) The diamond copper core was activated in a 10% hydrochloric acid solution for 10 s. The Ni / Pr alloy target of Preparation Example 5 was placed at the cathode and the diamond copper core was placed at the anode. A sputtering temperature of 150 °C and a pressure of 1 Pa were applied at 3000 W / cm². 2 Magnetron sputtering was performed at a power density, and the same operation was performed on the opposite surface to form a 2 μm thick Ni / Pr composite intermediate layer on the upper and lower surfaces of the diamond copper core.

[0063] (3) Place copper sheets of equal area and 0.2 mm thickness on the upper and lower surfaces of the above Ni / Pr composite intermediate layer, apply a pressure of 3 MPa perpendicular to the layer direction, and apply the pressure at a vacuum degree of 10. -4 Diamond-copper composite material was obtained by brazing at 800 ℃ for 35 min under the conditions of Pa.

[0064] Example 1 provides a diamond copper-based composite material, which is prepared by the above preparation method. Its structural schematic diagram is shown in Figure 2, where 1 is the diamond copper core material, 2 is the Ni / Pr composite intermediate layer, and 3 is the copper sheet.

[0065] Example 2

[0066] Example 2 provides a method for preparing a diamond-copper matrix composite material, the specific steps of which are as follows:

[0067] (1) The modified diamond powder and copper powder prepared in Preparation Example 2 were ball-milled and mixed evenly according to a volume ratio of diamond powder to copper powder of 1:1. The mixture was then placed into a mold and subjected to a vacuum of 10. -2 Under the conditions of Pa and applied pressure of 40 MPa, the diamond copper core material with a thickness of 1 mm was obtained by sintering at 900 ℃ for 10 min and cooling.

[0068] (2) The diamond copper core material was activated in an 8% hydrochloric acid solution for 8 s. The Ni / Pr alloy target of Preparation Example 6 was placed at the cathode and the diamond copper core material was placed at the anode. A sputtering temperature of 1 Pa and a sputtering temperature of 120 °C were applied at a pressure of 2000 W / cm². 2 Magnetron sputtering was performed at a power density, and the same operation was performed on the opposite surface to form a 0.5 μm thick Ni / Pr composite intermediate layer on the upper and lower surfaces of the diamond copper core.

[0069] (3) Place copper sheets of equal area and 0.2 mm thickness on the upper and lower surfaces of the above Ni / Pr composite intermediate layer, apply a pressure of 2 MPa perpendicular to the layer direction, and apply the pressure at a vacuum degree of 10. -3 Diamond-copper composite material was obtained by brazing at 750 ℃ ​​for 30 min under the conditions of Pa.

[0070] Example 2 provides a diamond-copper-based composite material, which is prepared by the above preparation method.

[0071] Example 3

[0072] Example 3 provides a method for preparing a diamond-copper matrix composite material, the specific steps of which are as follows:

[0073] (1) The modified diamond powder and copper powder prepared in Preparation Example 3 were ball-milled and mixed evenly according to a volume ratio of diamond powder to copper powder of 1:2.2. The mixture was then placed into a mold and subjected to a vacuum of 10. -3 Under the conditions of Pa and 50 MPa pressure, the diamond copper core material with a thickness of 10 mm was obtained by sintering at 1000 ℃ for 15 min and cooling.

[0074] (2) The diamond copper core was activated in a 12% hydrochloric acid solution for 12 s. The Ni / Pr alloy target of Preparation Example 7 was placed at the cathode and the diamond copper core was placed at the anode. A sputtering temperature of 200 °C and a sputtering pressure of 4000 W / cm² were applied. 2 Magnetron sputtering was performed at a power density, and the same operation was performed on the opposite surface to form a 3 μm thick Ni / Pr composite intermediate layer on the upper and lower surfaces of the diamond copper core.

[0075] (3) Place copper sheets of equal area and 0.3 mm thickness on the upper and lower surfaces of the above Ni / Pr composite intermediate layer, apply a pressure of 5 MPa perpendicular to the layer direction, and apply the pressure at a vacuum degree of 10. -5 Diamond-copper composite material was obtained by brazing at 860 ℃ for 40 min under the conditions of Pa.

[0076] Example 3 provides a diamond-copper-based composite material, which is prepared by the above preparation method.

[0077] (III) Comparative Example

[0078] Comparative Example 1

[0079] Comparative Example 1 is basically the same as Example 1, except that the modified diamond powder in Example 1 is replaced with the modified diamond powder obtained in Preparation Example 4.

[0080] Comparative Example 2

[0081] Comparative Example 2 is basically the same as Example 1, except that step (2) in Example 1 is omitted, that is, the Ni / Pr composite intermediate layer is omitted.

[0082] Comparative Example 3

[0083] Comparative Example 3 is basically the same as Example 1, except that the Ni / Pr alloy target in step (3) of Example 1 is replaced with the Ni target of Preparation Example 8.

[0084] (iv) Test Examples

[0085] The diamond-copper composite materials prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests.

[0086] Density test: The density of the diamond copper-based composite materials of Examples 1-3 and Comparative Examples 1-3 was calculated using the water displacement method. The results are shown in Table 1.

[0087] Thermal conductivity test: The thermal conductivity of the diamond copper-based composite materials of Examples 1-3 and Comparative Examples 1-3 was measured using a thermal diffusivity measuring instrument. The results are shown in Table 1.

[0088] Expansion coefficient test: The thermal expansion coefficients of the diamond copper-based composite materials of Examples 1-3 and Comparative Examples 1-3 were measured using a thermal expansion meter. The results are shown in Table 1.

[0089]

[0090] As shown in Table 1, the diamond-copper composite materials prepared in Examples 1-3 of this invention have high density, excellent thermal conductivity, low coefficient of thermal expansion, and are easy to process.

[0091] Compared to Example 1, Comparative Example 1, which used cobalt-plated diamond instead of modified diamond, showed a significant decrease in density and was also affected by thermal conductivity. This indicates that establishing a cobalt / silicene composite transition layer on the diamond surface can improve the density and thermal conductivity of the copper-based diamond composite material. Specifically, cobalt exhibits good wettability with diamond, enabling it to undergo interfacial reactions to form carbide phases such as Co3C, thus improving the sintering performance between diamond and copper. Cobalt can also serve as a metal catalytic substrate, promoting the deposition of silicene. Silicene possesses high chemical activity and a large specific surface area, reducing the surface energy of diamond and undergoing diffusion reactions with copper. During sintering, it forms a liquid phase, promoting structural rearrangement, improving sintering density, and enhancing the overall performance of the composite material.

[0092] Compared to Example 1, Comparative Example 2 omitted the Ni / Pr composite interlayer, while Comparative Example 3 replaced the Ni / Pr composite interlayer with a Ni interlayer. The thermal conductivity decreased significantly, the coefficient of thermal expansion increased, and the density also decreased. This indicates that the Ni / Pr composite interlayer can effectively improve the thermal conductivity and coefficient of thermal expansion of the diamond-copper composite material. Specifically, Ni has good weldability, while Pr has a low coefficient of thermal expansion, good interface activation, and impurity adsorption. Combining Ni and Pr can purify the interface, reduce coating porosity, and improve interfacial bonding performance, forming a dense and well-bonded coating on the surface of the diamond-copper core material. This improves the thermal conductivity and weldability of the diamond-copper core material, facilitating the welding of copper-diamond-copper core material-copper, and thus improving the weld airtightness and coefficient of thermal expansion of the diamond-copper composite material.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A method for preparing a diamond-copper matrix composite material, characterized in that, The process includes the following steps: (1) ball milling and mixing modified diamond powder and copper powder, followed by hot pressing and sintering to obtain diamond copper core material; (2) activating the diamond copper core material, and then magnetron sputtering Ni / Pr alloy target material onto the upper and lower surfaces of the activated diamond copper core material to form a Ni / Pr composite intermediate layer; (3) vacuum welding copper sheets onto the upper and lower surfaces of the Ni / Pr composite intermediate layer to obtain a diamond copper-based composite material; the modified diamond powder is prepared by the following process: (a) vacuum evaporation to deposit a cobalt layer on the surface of diamond particles to obtain cobalt-plated diamond; (b) placing the cobalt-plated diamond in a mixed gas of silane and hydrogen, and depositing silane under heating conditions to obtain modified diamond powder.

2. The method for preparing the diamond-copper matrix composite material according to claim 1, characterized in that, The parameters for vacuum evaporation in step (a) are: vacuum degree of 10. -2 -10 -4 The concentration of metal vapor is 35-45% at Pa, the temperature is 720-760 ℃, and the plating time is 2-3 h; the particle size of the diamond particles is 70-120 μm; and the thickness of the cobalt layer is 0.3-0.6 μm.

3. The method for preparing the diamond-copper matrix composite material according to claim 1, characterized in that, In step (b), the volume ratio of silane to hydrogen is 1:(1.5-2.5); the flow rate of the mixed gas is 10-15 sccm; the heating temperature is 600-700 ℃; the deposition time is 30-60 s; and the deposition thickness is 0.1-0.15 μm.

4. The method for preparing the diamond-copper matrix composite material according to claim 1, characterized in that, The volume ratio of modified diamond powder to copper powder in step (1) is 1:(1-2.2); the pressure of hot pressing sintering is 40-50 MPa, the temperature is 900-1000 ℃, and the time is 10-15 min; the thickness of the diamond copper core material is 1-10 mm.

5. The method for preparing the diamond-copper matrix composite material according to claim 1, characterized in that, The activation in step (2) is carried out in a hydrochloric acid solution with a mass fraction of 8-12% for 8-12 s; the parameters of the magnetron sputtering are: sputtering chamber pressure of 1-2 Pa, sputtering temperature of 120-200 ℃, and power density of 2000-4000 W / cm³. 2 The thickness of the Ni / Pr composite interlayer is 0.5-3 μm.

6. The method for preparing the diamond-copper matrix composite material according to claim 1, characterized in that, The vacuum welding step described in step (3) is as follows: at a vacuum degree of 10... -3 -10 -5 A pressure of 2-5 MPa is applied under Pa, and the temperature is maintained at 750-860 ℃ for 30-40 min; the thickness of the copper sheet is 0.2-0.3 mm.

7. The method for preparing the diamond-copper matrix composite material according to claim 1, characterized in that, The Ni / Pr alloy target material described in step (2) is prepared by the following process: Ni and Pr raw materials are mixed evenly, melted in an inert gas atmosphere, cast, cooled and demolded to obtain Ni / Pr alloy ingot; Ni / Pr alloy ingot is hot forged, cold rolled and heat-preserved to obtain Ni / Pr alloy target material.

8. The method for preparing the diamond-copper matrix composite material according to claim 7, characterized in that, The mass ratio of Ni to Pr is 1:(0.05-0.08); the hot forging temperature is 1000-1150 ℃; the heat preservation temperature is 800-850 ℃, and the time is 1-2 h.

9. A diamond-copper matrix composite material, characterized in that, It is prepared by the method for preparing diamond copper-based composite material according to any one of claims 1-8.

Images