A method for preparing a nanoparticle reinforced metal-diamond printed circuit board

Abstract

The application is a kind of preparation method of nanoparticle reinforced metal-diamond printed circuit board, belonging to the technical field of diamond circuit board. The circuit board is prepared by using high-thermal-conductivity diamond as a heat dissipation matrix and nanoparticle reinforced metal as circuit lines. In the preparation process, first, circuit lines are processed on a diamond substrate; second, the diamond substrate is placed in a mixed solution containing carbide-forming metal and high-conductivity metal nanoparticles for ultrasonic crystal planting; third, the crystal planting elements outside the circuit lines are removed and high-temperature treatment is performed; fourth, a high-conductivity metal element film layer is deposited and the metal film layer outside the circuit lines is removed; and finally, a nanoparticle reinforced metal-diamond printed circuit board is obtained. The application has the advantages of simple operation, energy saving, environmental friendliness, good adjustability of the size and density of the circuit lines, excellent conductivity and bonding performance, and high thermal conductivity, high strength, corrosion resistance and other advantages of the diamond matrix.

Description

Technical Field

[0001] The invention belongs to the technical field of diamonds, and in particular relates to a diamond printed circuit board, specifically a method for preparing a nanoparticle-reinforced metal-diamond printed circuit board. Background Art

[0002] As electronic products become increasingly multifunctional and complex, printed circuit boards (PCBs) are developing towards intelligent, lightweight, high-precision, and highly integrated features. In addition to fulfilling their traditional roles of conductivity, insulation, and support, they also need to further reduce their size, improve structural stability, and enhance heat resistance and heat dissipation. Currently, the most commonly used PCBs, including copper-clad laminates (CCLs), have high requirements for raw material quality and technical expertise. Furthermore, the processing of these materials is complex, requiring high-quality equipment and resulting in high input and low output. Furthermore, the copper circuits produced through processes such as lamination, exposure, development, etching, stripping, and rinsing generate environmentally harmful wastewater. Therefore, there is an urgent need to develop cost-effective, energy-efficient, environmentally friendly, and high-performance PCBs. Summary of the Invention

[0003] The present invention aims to overcome the problems of conventional printed circuit boards, such as complex production, high cost, insufficient heat dissipation and thermal conductivity, and low bonding strength between the substrate and metal traces. The invention provides a method for preparing a nanoparticle-reinforced metal-diamond printed circuit board. This circuit board is a high-efficiency printed circuit board made from a highly conductive and thermally conductive nanoparticle-reinforced metal trace and a highly insulating and thermally conductive diamond substrate.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for preparing a nanoparticle-reinforced metal-diamond printed circuit board comprises the following steps:

[0006] A. Processing circuit lines with depth and roughness on the top surface of the diamond substrate and removing surface impurities;

[0007] B. Placing the treated diamond substrate in a crystal planting solution for ultrasonic crystal planting, so that the metal particles are planted and distributed on the surface of the diamond substrate and in the circuit pattern;

[0008] C. Remove all crystalline elements on the diamond substrate except for the circuit lines;

[0009] D. placing the cleaned diamond substrate in a vacuum apparatus for high-temperature heating to allow the carbides in the planted crystal elements to react with the carbon on the surface of the diamond substrate to form metals;

[0010] E. depositing a highly conductive metal film layer on the surface of the diamond substrate after high temperature heating;

[0011] F. After the deposition is completed, the highly conductive metal film layer on the diamond substrate except for the circuit lines is removed to obtain a single-layer nanoparticle reinforced metal-diamond printed circuit board.

[0012] Furthermore, in step A, the diamond substrate is composed of one or both of polycrystalline diamond and single crystal diamond, the method for processing the circuit pattern includes one or more of laser photolithography, masking method, and plasma etching method, the roughness of the circuit pattern is 0.5 to 1000 nm, and the depth of the circuit pattern is 0.2 to 10 μm. The method for removing surface impurities includes one of high temperature method and oxygen plasma etching method, and the surface impurities include graphite phase.

[0013] Furthermore, in step B, the crystal planting solution is composed of a nano-sized carbide-forming metal and a highly conductive metal aqueous sol, the carbide-forming metal includes one of Ti, Ta, W, Mo, Cr, and Zr, and the highly conductive metal includes one of Cu, Al, Ag, and Au. The nanoparticle size of the two metals is 10 to 60 nm, the frequency of ultrasonic crystal planting is 500 to 1000 Hz, and the time of ultrasonic crystal planting is 30 to 90 min.

[0014] Furthermore, in step C, the method for removing the phytocrystalline elements includes a polishing and cleaning method and a chemical solution scrubbing method.

[0015] Furthermore, in step D, the high temperature heating treatment is performed at a temperature of 500 to 800° C. and a time of 0.3 to 1.5 h.

[0016] Furthermore, in step E, the method for depositing the highly conductive metal film layer includes one of sputtering, evaporation, and arc method. The highly conductive metal is the same as the highly conductive metal in the crystal planting solution in step B. The thickness of the highly conductive metal film layer is 0.2 to 10 μm.

[0017] Furthermore, in step F, the method of removing the highly conductive metal film layer includes one or both of a polishing method and a solution cleaning method.

[0018] Furthermore, a diamond film is deposited on the surface of the resulting single-layer nanoparticle-reinforced metal-diamond printed circuit board via chemical vapor deposition. Steps A to F are then repeated using the deposited diamond film as a diamond substrate to obtain a multi-layer nanoparticle-reinforced metal-diamond printed circuit board. The thickness, composition, and pattern of the diamond substrate and the metal circuit patterns in each layer of the deposited circuit board can be the same or different, and the period of the multi-layer circuit board can be 1 to 100.

[0019] Furthermore, the chemical vapor deposition method includes one of a hot filament CVD method, a DC arc plasma jet CVD method, and a microwave plasma CVD method, and the deposition thickness of the diamond film is 10 μm to 700 μm.

[0020] In this invention, diamond is used as the heat dissipation matrix material. Diamond, due to its excellent mechanical properties, high thermal conductivity, and corrosion resistance, can replace traditional heat dissipation matrix materials such as ceramics and polymers. Metal nanoparticles possess superconducting properties, enhancing the electrical and thermal conductivity of metal circuits. After the planted element is heated, the planted metal reacts with the carbon on the diamond surface to form carbide nanoparticles, which improve the bonding strength between the metal and the diamond matrix.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The circuit pattern with a certain depth and roughness in the present invention can improve adhesion through mechanical interlocking, and on the other hand, it is easy to achieve high density and high precision control of the circuit pattern, and has the advantages of simple operation, strong controllability, and high resource utilization.

[0023] 2) In the present invention, carbide-forming metal and highly conductive metal are planted and subjected to high-temperature treatment on the circuit line. After the treatment, the circuit line groove contains carbides formed by the chemical combination of carbide-forming metal and carbon on the diamond surface, as well as metal nanoparticles and a very small amount of alloy. The high-temperature treatment enhances the interaction between the nanoparticles. On the one hand, the bonding effect of carbides in such a mixture transition layer improves the bonding strength between the transition layer and the diamond substrate. On the other hand, the highly conductive metal nanoparticles serve as nucleation points for the subsequent deposition of the metal film layer, thereby increasing the deposition rate of the metal film layer in the groove and its bonding strength with the transition layer. In addition, the nano-metal particles have superconducting properties, which further improve the electrical and thermal conductivity of the surface metal film layer. It has the advantages of simple operation, short time consumption, safety, environmental protection, and easy implementation.

[0024] 3) By processing circuits and planting nanometal powders, this method can solve the problems of uneven charge accumulation and poor bonding in the grooves during simple physical / chemical vapor deposition processes, enabling high-density interconnect construction. It has the advantages of simple operation and ease of implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic structural diagram of a single-layer nanoparticle-reinforced metal-diamond printed circuit board according to the present invention.

[0027] Figure 2 The figure is a schematic diagram of the preparation process of a single-layer nanoparticle reinforced metal-diamond printed circuit board in the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of a multi-layer nanoparticle reinforced metal-diamond printed circuit board in the present invention.

[0029] In the figure: 1-diamond substrate, 2-circuit diagram, 3-carbide-forming metal, 4-highly conductive metal, 5-metal alloy, 6-metal carbide, 7-highly conductive metal film. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0031] The present invention provides a nanoparticle-reinforced metal-diamond printed circuit board, the structure of which is as follows: Figure 1 As shown, it includes a diamond substrate 1 , the upper surface of which is provided with a circuit pattern 2 having depth and roughness, and a highly conductive metal film layer 7 is formed in the circuit pattern 2 .

[0032] The preparation method of the nanoparticle-reinforced metal-diamond printed circuit board provided by the present invention is as follows: Figure 2 As shown, it specifically includes the following steps:

[0033] A. Processing a circuit pattern 2 with depth and roughness on the upper surface of the diamond substrate 1 and removing surface impurities, such as Figure 2 A in

[0034] In step A, the diamond substrate 1 is composed of one or both of polycrystalline diamond and single crystal diamond. The method for processing the circuit pattern 2 includes one or more of laser photolithography, masking method, and plasma etching method. The roughness of the circuit pattern 2 is 0.5 to 1000 nm, and the depth of the circuit pattern 2 is 0.2 to 10 μm. The method for removing surface impurities includes one of high temperature method and oxygen plasma etching method. The surface impurities include graphite phase.

[0035] B. Place the treated diamond substrate 1 in a crystal planting solution for ultrasonic crystal planting, so that the metal particles are planted and distributed on the surface of the diamond substrate 1 and in the circuit line 2, as shown in FIG. Figure 2 B in

[0036] In step B, the crystal planting solution is composed of a nano-sized carbide-forming metal 3 and a highly conductive metal 4 aqueous sol, the carbide-forming metal 3 includes one of Ti, Ta, W, Mo, Cr, and Zr, and the highly conductive metal 4 includes one of Cu, Al, Ag, and Au. The nanoparticle size of the two metals is 10 to 60 nm, the frequency of ultrasonic crystal planting is 500 to 1000 Hz, and the time of ultrasonic crystal planting is 30 to 90 min.

[0037] C. Remove the plant crystal elements on the diamond substrate 1 except the circuit line 2, such as Figure 2 C in;

[0038] In step C, the method for removing the phytoplankton elements includes a polishing and cleaning method and a chemical solution scrubbing method.

[0039] D. Place the cleaned diamond substrate 1 in a vacuum device for high temperature heating, so that the carbides in the plant crystal elements easily form metals and react with the carbon on the surface of the diamond substrate 1, such as Figure 2 D in;

[0040] In step D, the high temperature heating treatment is performed at a temperature of 500 to 800° C. and for a time of 0.3 to 1.5 h.

[0041] E. Depositing a highly conductive metal film layer 7 on the surface of the diamond substrate 1 after high temperature heating treatment, such as Figure 2 E in;

[0042] In step E, the method for depositing the highly conductive metal film layer 7 includes one of sputtering, evaporation, and arc deposition. The highly conductive metal is the same as the highly conductive metal in the crystal planting solution in step B. The thickness of the highly conductive metal film layer 7 is 0.2 to 10 μm.

[0043] F. After the deposition is completed, the highly conductive metal film layer 7 on the diamond substrate 1 except for the circuit pattern line 2 is removed, as shown in FIG. Figure 2 Finally, a single-layer nanoparticle-reinforced metal-diamond printed circuit board is obtained;

[0044] In step F, the method of removing the highly conductive metal film layer includes one or both of a polishing method and a solution cleaning method.

[0045] A diamond film is deposited on the surface of the obtained single-layer nanoparticle-reinforced metal-diamond printed circuit board by chemical vapor deposition, and the deposited diamond film is used as the diamond substrate 1 to continue repeating steps AF to obtain a multi-layer nanoparticle-reinforced metal-diamond printed circuit board, whose structure is as follows: Figure 3 As shown; wherein, the chemical vapor deposition method includes one of a hot filament CVD method, a DC arc plasma jet CVD method, and a microwave plasma CVD method, and the deposition thickness of the diamond film is 10 μm to 700 μm.

[0046] In the nanoparticle-enhanced metal-diamond printed circuit board provided by the present invention, Figure 1 As shown, the highly conductive metal film layer 7 is primarily composed of a highly conductive metal 4, along with small amounts of metal carbide 6 and metal alloy 5. The metal carbide 6 is formed by the high-temperature reaction of the carbide-forming metal 3 with carbon on the surface of the diamond substrate 1. The metal alloy 5 is formed by the high-temperature reaction of the carbide-forming metal 3 with the highly conductive metal 4. The metal element nanoparticles possess superconducting properties, enhancing the electrical and thermal conductivity of the highly conductive metal film layer 7. After the planted element is heated, the planted metal reacts with the carbon in the diamond substrate 1 to form carbide nanoparticles, which improve the bonding strength between the metal and the diamond substrate 1.

[0047] Several specific embodiments are listed below to further illustrate the present invention:

[0048] Example 1

[0049] A single-layer nanoparticle reinforced metal-diamond printed circuit board is composed of a single-layer polycrystalline diamond substrate and a Cu circuit line. The preparation process is as follows: Figure 2 As shown, the specific steps include:

[0050] A. Using polycrystalline diamond as the diamond substrate, a circuit pattern is formed on its surface through laser lithography. The roughness of the bottom of the circuit pattern is 1000 nm, and the depth of the circuit pattern is 10 μm. The etched diamond substrate is then placed in a high-temperature furnace and heated at 800°C for 1 hour to remove impurities such as graphite on the surface.

[0051] B. The diamond substrate after graphite phase removal was ultrasonically treated in deionized water and alcohol for 15 minutes respectively. After drying, it was placed in a crystallization solution made of nano-Ti powder (size 40 nm) dissolved in nano-Cu hydrosol (size 10 nm, commercially available) for ultrasonic crystallization. The frequency of ultrasonic crystallization was 500 Hz and the ultrasonic crystallization time was 30 minutes.

[0052] C. After the ultrasonic crystal planting is completed, use dilute nitric acid to wipe the surface area outside the circuit line to remove a small amount of crystal particles outside the circuit line area.

[0053] D. Place the treated diamond substrate in a heatable magnetron sputtering device. When the vacuum in the chamber reaches below 1.0 Pa, set the heating time to 0.5 h, finally reaching a temperature of 500 °C, and maintain the temperature for 1 h.

[0054] E. The vacuum degree of the magnetron sputtering equipment chamber reaches 1.0×10 -4 Pa, a highly conductive metal Cu film was deposited by sputtering: Ar gas was introduced at a flow rate of 50 mL / min, a gas pressure of 0.3 Pa, a sputtering power of 300 W for the Cu target, a substrate bias of -200 V, a deposition time of 3 h, and a deposited film thickness of about 6 μm.

[0055] F. The diamond substrate coated with the highly conductive Cu film layer is soaked and cleaned with a NaCl salt solution, the highly conductive Cu film layer outside the circuit pattern is removed, and ultrasonic cleaning is performed with alcohol to obtain the single-layer nanoparticle reinforced metal-diamond printed circuit board. The structural diagram thereof is shown in FIG. Figure 1 shown.

[0056] Example 2

[0057] A double-layer nanoparticle reinforced metal-diamond printed circuit board, the upper layer of which is composed of polycrystalline diamond and Au circuit lines, and the lower layer is composed of single crystal diamond and Au circuit lines, and its structure is as follows Figure 3 As shown, the preparation method comprises the following steps:

[0058] A. Using single-crystal diamond as the diamond substrate, a circuit pattern is formed on the surface of the diamond substrate using a masking method. The roughness of the bottom of the circuit pattern is 0.5 nm, and the depth of the circuit pattern is 0.2 μm. The etched diamond substrate is then placed in a device that can generate oxygen plasma, and impurities such as graphite on the surface are removed through oxygen plasma etching.

[0059] B. The diamond substrate after graphite phase removal was ultrasonically treated in deionized water and alcohol for 45 minutes respectively. After drying, it was placed in a crystal planting solution made of nano-Mo powder (size 60 nm) dissolved in nano-Au hydrosol (size 20 nm, commercially available) for ultrasonic crystal planting. The frequency of ultrasonic crystal planting was 800 Hz and the ultrasonic crystal planting time was 60 minutes.

[0060] C. After the ultrasonic crystal planting is completed, use 1200 mesh and 2000 mesh sandpaper to polish the surface of the diamond substrate to remove the crystal particles outside the circuit line on the surface area.

[0061] D. Place the treated diamond substrate in a heated electron beam evaporation device. When the vacuum in the chamber reaches below 0.1 Pa, set the heating time to 50 minutes, finally reaching a temperature of 800°C, and maintain the temperature for 18 minutes.

[0062] E. Wait until the vacuum degree of the electron beam evaporation equipment reaches 5.0×10 -4 Pa, a highly conductive metal Au film was deposited by evaporation: the evaporation power of the Au target was set to 2.4 kW, the evaporation time was 1 h, and the coating thickness was 0.2 μm.

[0063] F. The diamond substrate coated with the highly conductive Au film was polished with 1200-grit and 2000-grit sandpaper, respectively, and ultrasonically cleaned with alcohol to remove the highly conductive Au film outside the circuit pattern, thereby obtaining a single-layer nanoparticle-reinforced metal-diamond printed circuit board.

[0064] G. Depositing a diamond film on the surface of the above-mentioned single-layer nanoparticle-reinforced metal-diamond printed circuit board by microwave plasma CVD method, the chamber pressure is 2000 Pa, the H2:CH4 gas volume flow ratio is 5:1, the microwave power is 20 kW, the temperature is 900°C, and the deposition thickness of the deposited insulating polycrystalline diamond layer is 10 μm. The deposited polycrystalline diamond layer is used as the diamond substrate, and the above-mentioned steps A to F are further repeated to finally obtain the said double-layer nanoparticle-reinforced metal-diamond printed circuit board, as shown in FIG. Figure 3 shown.

[0065] Example 3

[0066] A method for preparing a nanoparticle-reinforced metal-diamond printed circuit board comprises the following steps:

[0067] A. Using polycrystalline diamond as the diamond substrate, a circuit pattern is formed on the surface through plasma etching technology. The roughness of the bottom of the circuit pattern is 700 nm, and the depth of the circuit pattern is 6 μm. The etched diamond substrate is then placed in a device that can generate oxygen plasma to remove surface impurities such as graphite.

[0068] B. The diamond substrate after graphite phase removal was ultrasonically treated in deionized water and alcohol for 30 minutes respectively. After drying, it was placed in a crystallization solution made of nano-W powder (size 50 nm) dissolved in nano-Al hydrosol (size 10 nm, commercially available) for ultrasonic crystallization. The frequency of ultrasonic crystallization was 1000 Hz and the ultrasonic crystallization time was 90 minutes.

[0069] C. After the ultrasonic crystal planting is completed, use dilute hydrochloric acid to wipe the surface area outside the circuit line to remove a small amount of crystal particles outside the surface circuit line area.

[0070] D. Place the treated diamond substrate in a heatable arc device. When the vacuum in the chamber reaches below 0.1 Pa, set the heating time to 60 minutes, finally reaching a temperature of 600°C, and maintain the temperature for 1.5 hours.

[0071] E. Deposition of highly conductive metal Al film: Adjust the discharge arc voltage of the Al target to 50 V, the discharge arc current to 55 A, the deposition time to 3 h, and the deposited film thickness to approximately 10 μm.

[0072] F. The diamond substrate coated with the highly conductive metal Al film layer was polished with 1800-mesh and 2200-mesh sandpapers respectively to remove the highly conductive metal Al film layer outside the circuit pattern on the surface and then ultrasonically cleaned with alcohol to obtain the nanoparticle-reinforced metal-diamond printed circuit board. The structure thereof is as follows: Figure 1 shown.

[0073] Example 4

[0074] A three-layer nanoparticle-reinforced metal-diamond printed circuit board, wherein the bottom layer is composed of a polycrystalline diamond substrate and Ag circuit lines, the middle layer is composed of a polycrystalline diamond substrate and Cu circuit lines, and the upper layer is composed of a polycrystalline diamond substrate and Au circuit lines. The preparation method thereof comprises the following steps:

[0075] A. Using polycrystalline diamond as a diamond substrate, a circuit pattern is formed on its surface through mask-coupled plasma etching. The roughness of the bottom of the circuit pattern is 300 nm, and the depth of the circuit pattern is 4 μm. The etched diamond substrate is then heated in a high-temperature furnace at 700°C for 3 hours to remove impurities such as graphite on the surface.

[0076] B. The diamond substrate after graphite phase removal was ultrasonically treated in deionized water and alcohol for 20 minutes respectively. After drying, it was placed in a crystal planting solution made of nano-Ta powder (size 50 nm) dissolved in nano-Ag hydrosol (size 30 nm, commercially available) for ultrasonic crystal planting. The frequency of ultrasonic crystal planting was 750 Hz and the ultrasonic crystal planting time was 50 minutes.

[0077] C. After the ultrasonic crystal planting is completed, the surface of the diamond substrate is polished with 1000 mesh, 1500 mesh and 2500 mesh sandpaper to remove the crystal particles outside the circuit line of the surface area.

[0078] D. Place the treated diamond substrate in a heated magnetron sputtering device. When the chamber vacuum reaches below 0.1 Pa, set the temperature to rise for 40 minutes, ultimately reaching a temperature of 700°C, and maintain the temperature for 50 minutes.

[0079] E. The vacuum degree of the magnetron sputtering equipment chamber reaches 5.0×10 -4 Pa, a highly conductive metal Ag film was deposited: the sputtering power of the Ag target was set to 500 W, the sputtering time was set to 3.5 h, and the coating thickness was set to 4 μm.

[0080] F. The diamond substrate coated with the highly conductive Ag film was polished with 1000-mesh, 1500-mesh, and 2500-mesh sandpaper, respectively, and ultrasonically cleaned with alcohol to remove the highly conductive Ag film outside the circuit pattern, thereby obtaining a single-layer nanoparticle-reinforced metal-diamond printed circuit board.

[0081] G. A diamond film was deposited on the surface of the above-mentioned single-layer nanoparticle-reinforced metal-diamond printed circuit board by a microwave plasma CVD method. The chamber pressure was 8000 Pa, the H2:CH4 gas volume flow ratio was 1:1, the microwave power was 80 kW, and the temperature was 600°C. The deposited insulating polycrystalline diamond layer had a deposition thickness of 700 μm. The deposited polycrystalline diamond layer was used as a diamond substrate. Steps A to F were further repeated. When repeating step B, the nano-Ag aqueous sol was replaced with a nano-Cu aqueous sol. Finally, a double-layer nanoparticle-reinforced metal-diamond printed circuit board was obtained.

[0082] H. Depositing a diamond film on the surface of the above-mentioned double-layer nanoparticle-reinforced metal-diamond printed circuit board by a microwave plasma CVD method, the chamber pressure is 10,000 Pa, the H2:CH4 gas volume flow ratio is 3:2, the microwave power is 100 kW, the temperature is 800°C, and the deposited insulating polycrystalline diamond layer has a deposition thickness of 500 μm. The deposited polycrystalline diamond layer is used as a diamond substrate, and steps A to F are further repeated. When repeating step B, the nano-Ag aqueous sol is replaced with a nano-Au aqueous sol, and finally the three-layer nanoparticle-reinforced metal-diamond printed circuit board is obtained.

[0083] It should be noted that the above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. The embodiments and features of the embodiments may be combined with each other unless there is a conflict. Any modifications, equivalent substitutions, improvements, and other variations made within the technical scope and principles disclosed herein shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a nanoparticle-reinforced metal-diamond printed circuit board, characterized in that: The following steps are involved: A. Processing circuit lines with depth and roughness on the top surface of the diamond substrate and removing surface impurities; B. Placing the treated diamond substrate in a seeding solution for ultrasonic seeding, so that metal particles are distributed on the surface of the diamond substrate and within the circuit pattern. The seeding solution is composed of a nanometer-sized carbide-forming metal and a highly conductive metal aqueous sol. The carbide-forming metal includes one of Ti, Ta, W, Mo, Cr, and Zr, and the highly conductive metal includes one of Cu, Al, Ag, and Au. C. Remove all crystalline elements on the diamond substrate except for the circuit lines; D. Place the cleaned diamond substrate in a vacuum device for high-temperature heating, so that the carbides in the plant crystal elements can easily form metals and react with the carbon on the surface of the diamond substrate; E. depositing a highly conductive metal film layer on the surface of the diamond substrate after high temperature heating; F. After the deposition is completed, the highly conductive metal film layer on the diamond substrate except for the circuit lines is removed to obtain a single-layer nanoparticle reinforced metal-diamond printed circuit board.

2. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, wherein: In step A, the diamond substrate is composed of one or both of polycrystalline diamond and single crystal diamond, the method for processing the circuit pattern includes one or more of laser photolithography, masking method, and plasma etching method, the roughness of the circuit pattern is 0.5 to 1000 nm, and the depth of the circuit pattern is 0.2 to 10 μm. The method for removing surface impurities includes one of high temperature method and oxygen plasma etching method, and the surface impurities include graphite phase.

3. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, wherein: In step B, the crystal planting solution is composed of a nano-sized carbide-forming metal and a highly conductive metal aqueous sol. The carbide-forming metal includes one of Ti, Ta, W, Mo, Cr, and Zr, and the highly conductive metal includes one of Cu, Al, Ag, and Au. The nanoparticle size of the two metals is 10 to 60 nm, the frequency of ultrasonic crystal planting is 500 to 1000 Hz, and the time of ultrasonic crystal planting is 30 to 90 min.

4. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, wherein: In step C, the method for removing the phytoplankton elements includes a polishing and cleaning method and a chemical solution scrubbing method.

5. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, wherein: In step D, the high temperature heating treatment is performed at a temperature of 500 to 800° C. and for a time of 0.3 to 1.5 h.

6. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, wherein: In step E, the method for depositing the highly conductive metal film layer includes one of sputtering, evaporation, and arc deposition. The highly conductive metal is the same as the highly conductive metal in the crystal planting solution in step B. The thickness of the highly conductive metal film layer is 0.2 to 10 μm.

7. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, characterized in that: In step F, the method of removing the highly conductive metal film layer includes one or both of a polishing method and a solution cleaning method.

8. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 1, characterized in that: A diamond film is deposited on the surface of the obtained single-layer nanoparticle reinforced metal-diamond printed circuit board by chemical vapor deposition, and steps AF are repeated using the deposited diamond film as a diamond substrate to obtain a multi-layer nanoparticle reinforced metal-diamond printed circuit board.

9. The method for preparing a nanoparticle-reinforced metal-diamond printed circuit board according to claim 8, wherein: The chemical vapor deposition method includes one of a hot filament CVD method, a DC arc plasma jet CVD method, and a microwave plasma CVD method, and the deposition thickness of the diamond film is 10 μm to 700 μm.

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