Diamond copper composite material for electronic packaging heat dissipation and preparation method of diamond copper composite material

Abstract

The invention relates to a thermal management material in the field of advanced non-ferrous metal materials, and particularly discloses a diamond / copper composite material for electronic packaging and heat dissipation and a preparation method of the diamond / copper composite material. Diamond and copper in the diamond / copper composite material are connected through carbide, the thickness of a carbide layer is smaller than 50 nm, the particle size of the diamond is 300-500 microns, and the volume ratio of the diamond is 35-50%. The preparation method of the diamond / copper composite material comprises the following specific preparation steps: (1) carrying out erosion treatment on diamond; (2) carrying out surface metallization treatment on the eroded diamond; (3) carrying out plating reaction strengthening treatment on the diamond subjected to surface metallization treatment; (4) regularly arranging the diamonds on the substrate by using a vibrating screen and an adhesive; (5) carrying out magnetron sputtering treatment on the substrate; (6) carrying out electroplating thickening treatment on the substrate; (7) stripping the diamond / copper layer prepared by electroplating from the substrate; and (8) further electroplating and thickening the peeled diamond / copper layer to obtain the diamond / copper composite material. According to the method, the problem that the interface wettability of the diamond / copper composite material is poor is effectively solved, meanwhile, the interface thermal resistance is remarkably reduced, and the diamond / copper composite material with regular diamond arrangement and excellent heat conduction performance can be successfully prepared.

Description

Technical Field

[0001] This invention belongs to the field of advanced non-ferrous metal materials, specifically relating to a diamond / copper composite material for heat dissipation in electronic packaging and its preparation method. Background Technology

[0002] With semiconductor manufacturing technology officially entering the 2nm process era, the transistor density of chips has achieved a significant breakthrough. While high integration has driven a substantial improvement in chip performance, it has also brought about increasingly prominent heat accumulation problems. The heat dissipation capacity of traditional electronic packaging materials is no longer sufficient to meet the demands of current technological development. Developing new heat dissipation materials with superior thermal conductivity has become a critical issue that the industry urgently needs to address. From a material properties perspective, copper has high thermal conductivity among metals, reaching up to 400 W / (m·K), making it an ideal matrix for preparing heat dissipation materials. Diamond, on the other hand, has the highest thermal conductivity in nature, reaching up to 2200 W / (m·K). Therefore, introducing diamond particles into a copper matrix to prepare diamond / copper composite materials is widely considered an effective solution.

[0003] With its excellent thermal conductivity and low coefficient of thermal expansion, diamond / copper composites have shown great promise in key technology fields such as electronic packaging, 5G communication, artificial intelligence, and aerospace. However, the research and application of this material still face two major challenges: First, the interfacial wettability between diamond and copper is poor, easily forming numerous voids at the interface when they are bonded together, which severely hinder heat transfer paths. Second, the heat conduction mechanisms of copper and diamond are fundamentally different. Copper mainly relies on electron motion for heat transfer, while diamond transfers heat through the vibration of phonons in the crystal lattice. Furthermore, the significant difference in their Debye temperature and acoustic impedance further increases the interfacial thermal resistance, leading to a substantial reduction in the efficiency of heat transfer across the interface. Therefore, how to effectively enhance the interfacial bonding strength between copper and diamond, reduce the interfacial thermal resistance, and thus improve the overall thermal conductivity of the composite material has become a core challenge in this field. Summary of the Invention

[0004] This invention addresses industry challenges such as poor wettability between diamond and copper substrates, difficulty in molding ultra-thin diamond / copper composite materials, and uneven diamond distribution within the composite material. It employs a synergistic process involving chemical etching, surface metallization, interface strengthening, adhesive bonding for ordered arrangement, and electroplating to prepare diamond / copper composite materials for heat dissipation in electronic packaging. The specific technical solution is as follows:

[0005] A method for preparing a diamond / copper composite material for heat dissipation in electronic packaging includes the following steps:

[0006] a) The raw diamond is cleaned to remove oil and dirt, then chemically etched, and finally washed and dried.

[0007] b) Perform surface metallization treatment on the diamond obtained in step a);

[0008] c) Perform a reaction strengthening treatment on the surface-metallized diamond obtained in step b);

[0009] d) Use a vibrating screen and adhesive to evenly bond the diamond obtained in step c) onto the substrate;

[0010] e) Perform magnetron sputtering on the substrate with uniformly deposited diamond obtained in step d).

[0011] f) Perform electroplating on the substrate obtained in step e);

[0012] g) Perform peeling and carbonization debonding on the copper-clad substrate obtained in step f);

[0013] h) Electroplating is performed on the back side of the diamond / copper layer obtained in step g) to thicken it; after cleaning and drying, the diamond / copper composite material can be obtained.

[0014] Furthermore, in step a), the raw diamond has a particle size of 300-500 μm and a nitrogen content of approximately 150 ppm; the chemical etching treatment involves immersing the diamond in a chemical etching solution for 6-8 hours at a temperature of 120°C; the chemical etching solution is a mixture of nitric acid and sulfuric acid, with a volume ratio of nitric acid to sulfuric acid of 1:3 to 1:5.

[0015] Furthermore, the surface metallization treatment in step b) is to perform magnetron sputtering on diamond, with the coating being a strong carbide-forming element such as titanium, zirconium, tungsten, etc., the magnetron sputtering power being 80-125W, the time being 30-60min, and the working gas pressure being 0.2-0.7Pa.

[0016] Furthermore, the reaction enhancement treatment in step c) is carried out at a temperature of 900–1100°C for a time of 5–20 min.

[0017] Furthermore, the adhesive in step d) is PET double-sided tape, and the substrate is one of copper plate, PP plate, or PET plate. The bonding process uses a vibrating screen to put diamond particles into the vibrating screen. The screen mesh size is slightly larger than the diamond particle size. The substrate with double-sided tape is placed under the screen, and the substrate is slowly lowered so that the diamond particles fall evenly onto the substrate through the screen.

[0018] Furthermore, the magnetron sputtering process in step e) is magnetron sputtering of copper, with a sputtering power of 60-120W, a time of 10-40min, and a working gas pressure of 0.2-0.7Pa.

[0019] Furthermore, the electroplating process in step f) involves using an acidic sulfate copper plating solution to perform embedded diamond electroplating, with a copper plating current density of 2–10 A / dm³. 2 The electroplating time is 5 to 15 hours; the copper plating solution includes copper sulfate, sulfuric acid, sodium chloride, sodium polydisulfide dipropane sulfonate, polyethylene glycol, and an appropriate amount of brightener.

[0020] Furthermore, the degumming process described in step g) is carried out using a tube furnace, with a degumming temperature of 300–600°C, a holding time of 0.5–3 hours, and a hydrogen atmosphere.

[0021] Furthermore, the electroplating thickening treatment described in step h) involves single-sided electroplating thickening of the previously adhesive-bonded copper layer, with the same copper plating solution and current density as in step f), and the electroplating time being 2 to 5 hours.

[0022] The present invention also provides a diamond / copper composite material for heat dissipation in electronic packaging prepared by the aforementioned preparation method. In the composite material, the diamond particle size is 300-500 μm, the diamond volume ratio is 35-50%, the diamond and copper are connected by carbide, the carbide layer thickness is less than 50 nm, the diamond particle size is 300-500 μm, the diamond volume ratio is 35-50%, the material thermal conductivity is higher than 600 W / (m·K), and the thickness is less than 1 mm.

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

[0024] (1) After chemical etching, surface metallization, and reaction strengthening synergistic treatment, a continuous and dense carbide transition layer can be formed on the surface of diamond. Compared with diamond that has only undergone surface metallization treatment, this can significantly improve the bonding strength between the diamond and copper matrix in the composite material, effectively reduce the interfacial thermal resistance, and prevent interfacial cracking or structural deformation due to the difference in thermal expansion coefficients under long-term high-temperature cycling, thus extending the service life of thermal management components. At the same time, effective diamond surface pretreatment avoids the removal of the diamond surface metal layer during electroplating, ensuring the high thermal conductivity of the composite material.

[0025] (2) After being bonded by a vibrating screen and double-sided tape, the diamonds are arranged in a single layer on the substrate. The single-layer regular arrangement makes the spacing between diamond particles more uniform and the orientation stronger, which can build a continuous and low-impedance heat conduction channel, greatly reducing the thermal resistance of the interface between the copper matrix and the diamond. The overall thermal conductivity is significantly better than that of traditional copper-based materials and disordered diamond / copper composite materials, which can quickly dissipate the concentrated heat generated by high-power devices and avoid local overheating.

[0026] (3) For diamonds fixed by adhesive, a stable copper layer is first deposited on the substrate surface by magnetron sputtering, and then the copper layer is thickened by electroplating to obtain a diamond-copper composite material with excellent performance. The magnetron sputtering process metallizes the surface of the polymer substrate, and the deposited copper layer further protects the transition layer on the diamond surface. The synergistic application of this preparation process can effectively solve the problems of uneven diamond distribution and difficulty in forming ultra-thin composite materials that are easily caused by conventional electroplating and powder metallurgy preparation processes, and can successfully prepare ultra-thin diamond / copper composite materials with uniform performance and ultra-high thermal conductivity. Attached Figure Description

[0027] Figure 1 This is a SEM image of the diamond obtained after surface strengthening treatment in Example 1;

[0028] Figure 2 This is a macroscopic photograph of the diamond / copper composite material obtained in Example 2;

[0029] Figure 3 The image shows the XRD pattern of the diamond / copper composite material obtained in Example 3. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] (1) Use an ultrasonic cleaner to clean the raw diamond for 10 minutes to remove oil stains. The cleaning solution used consists of 20 g / L sodium hydroxide, 25 g / L sodium carbonate and 50 g / L detergent.

[0033] (2) The cleaned diamond was placed in a chemical etching solution and chemically etched for 6 hours at a temperature of 120°C using a magnetic stirring device. The chemical etching solution used consisted of 120 mL / L nitric acid and 450 mL / L sulfuric acid.

[0034] (3) Use magnetron sputtering equipment to perform tungsten coating on the surface of the chemically etched diamond. The magnetron sputtering power is 100W, the sputtering time is 40min, and the working pressure is 0.6Pa.

[0035] (4) The diamond with tungsten coating on its surface is placed in a vacuum induction melting furnace for reaction strengthening treatment. The reaction temperature is 1100℃ and the time is 10min.

[0036] (5) Use a vibrating screen and PET double-sided tape to evenly attach the reaction-strengthened tungsten-plated diamond onto the PP substrate.

[0037] (6) Place the PP plate with diamond attached in a magnetron sputtering equipment for magnetron sputtering copper layer treatment. The sputtering power is 90W, the time is 20min, and the working pressure is 0.6Pa.

[0038] (7) Connect the PP board with the sputtered copper layer to a DC power supply and place it in the copper plating solution for electroplating. The copper plating current density is 3A / dm³. 2 The electroplating time is 15 hours. The copper plating solution consists of 280 g / L copper sulfate, 80 g / L sulfuric acid, 0.035 g / L sodium chloride, 0.010 g / L sodium polydisulfide dipropane sulfonate, 0.030 g / L polyethylene glycol, and 2 mL / L brightener.

[0039] (8) Place the copper-clad PP board in a tube furnace for carbonization and degumming treatment. The carbonization temperature is 500℃ and the holding time is 2h. The atmosphere is hydrogen.

[0040] (9) Immerse the carbonized copper-clad PP board in an ethanol solution and use an ultrasonic cleaner for further degumming.

[0041] (10) The adhesive side of the debonded diamond / copper was subjected to single-sided copper electroplating for thickening, with a copper electroplating current density of 3A / dm². 2 The electroplating time is 5 hours. After cleaning and drying, the diamond / copper composite material is obtained.

[0042] The SEM scan image of the composite material is as follows: Figure 1 As shown in Table 1, the performance parameters of the diamond / copper composite material prepared in the above embodiment have a thermal conductivity as high as 681.9 W / (m·K). The diamond / copper composite material prepared by the above steps has a uniform diamond distribution and excellent thermal conductivity and thermal cycling performance.

[0043] Table 1. Diamond performance parameters of diamond / copper composite materials prepared in the examples.

[0044]

[0045] Example 2:

[0046] (1) Use an ultrasonic cleaner to clean the raw diamond for 10 minutes to remove oil stains. The cleaning solution used consists of 20 g / L sodium hydroxide, 25 g / L sodium carbonate and 50 g / L detergent.

[0047] (2) The cleaned diamond was placed in a chemical etching solution and chemically etched for 6 hours at a temperature of 120°C using a magnetic stirring device. The chemical etching solution used consisted of 120 mL / L nitric acid and 450 mL / L sulfuric acid.

[0048] (3) Use magnetron sputtering equipment to perform tungsten coating on the surface of the chemically etched diamond. The magnetron sputtering power is 80W, the sputtering time is 50min, and the working pressure is 0.5Pa.

[0049] (4) The diamond with tungsten coating on its surface is placed in a vacuum induction melting furnace for reaction strengthening treatment. The reaction temperature is 1000℃ and the time is 10min.

[0050] (5) Use PET double-sided tape to evenly adhere the reaction-strengthened tungsten-plated diamond onto the copper plate.

[0051] (6) Place the copper plate with diamond attached in a magnetron sputtering equipment for magnetron sputtering of copper layer. The sputtering power is 80W, the time is 30min, and the working pressure is 0.5Pa.

[0052] (7) Connect the PP board with the sputtered copper layer to a DC power supply and place it in the copper plating solution for electroplating. The copper plating current density is 6A / dm³. 2 The electroplating time is 8 hours. The copper plating solution consists of 280 g / L copper sulfate, 80 g / L sulfuric acid, 0.035 g / L sodium chloride, 0.010 g / L sodium polydisulfide dipropane sulfonate, 0.030 g / L polyethylene glycol, and 2 mL / L brightener.

[0053] (8) Place the copper-clad copper plate in a tube furnace for carbonization and degumming treatment. The carbonization temperature is 500℃ and the holding time is 2h. The atmosphere is hydrogen.

[0054] (9) The carbonized copper-clad board is immersed in an ethanol solution and then further degummed using an ultrasonic cleaner.

[0055] (10) The adhesive side of the debonded diamond / copper was thickened by single-sided electroplating with copper at a current density of 6 A / dm. 2 The electroplating time is 3 hours. After cleaning and drying, the diamond / copper composite material is obtained.

[0056] like Figure 2 As shown, the diamond / copper composite material prepared in the above embodiments exhibits regular diamond arrangement and a uniform copper plating on the surface. The diamond / copper composite material prepared through the preceding steps demonstrates excellent thermal conductivity, with a thermal conductivity coefficient reaching 659.2 W / (m·K).

[0057] Example 3:

[0058] (1) Use an ultrasonic cleaner to clean the raw diamond for 10 minutes to remove oil stains. The cleaning solution used consists of 20 g / L sodium hydroxide, 25 g / L sodium carbonate and 50 g / L detergent.

[0059] (2) The cleaned diamond was placed in a chemical etching solution and chemically etched for 6 hours at a temperature of 120°C using a magnetic stirring device. The chemical etching solution used consisted of 120 mL / L nitric acid and 450 mL / L sulfuric acid.

[0060] (3) Use magnetron sputtering equipment to perform tungsten coating on the surface of the chemically etched diamond. The magnetron sputtering power is 100W, the sputtering time is 40min, and the working pressure is 0.6Pa.

[0061] (4) The diamond with tungsten coating on its surface is placed in a vacuum induction melting furnace for reaction strengthening treatment. The reaction temperature is 1050℃ and the time is 10min.

[0062] (5) Use PET double-sided tape to evenly attach the reaction-strengthened tungsten-plated diamond onto the PP board.

[0063] (6) Place the PP plate with diamond attached in a magnetron sputtering equipment for magnetron sputtering copper layer treatment. The sputtering power is 120W, the time is 20min, and the working pressure is 0.6Pa.

[0064] (7) Connect the PP board with the sputtered copper layer to a DC power supply and place it in the copper plating solution for electroplating. The copper plating current density is 6A / dm³. 2 The time was 10 hours. The copper plating solution consisted of 280 g / L copper sulfate, 80 g / L sulfuric acid, 0.035 g / L sodium chloride, 0.010 g / L sodium polydisulfide dipropane sulfonate, 0.030 g / L polyethylene glycol, and 2 mL / L brightener.

[0065] (8) Place the copper-clad PP board in a tube furnace for carbonization and degumming treatment. The carbonization temperature is 500℃ and the holding time is 2h. The atmosphere is hydrogen.

[0066] (9) Immerse the carbonized copper-clad PP board in an ethanol solution and use an ultrasonic cleaner for further degumming.

[0067] (10) The adhesive side of the debonded diamond / copper was thickened by single-sided electroplating with copper at a current density of 6 A / dm. 2 The electroplating time is 4 hours. After cleaning and drying, the diamond / copper composite material is obtained.

[0068] like Figure 3As shown, the diamond / copper composite material prepared in the above embodiments exhibits characteristic copper peaks in its XRD pattern, and also shows a distinct diamond (111) crystal plane characteristic peak at 2θ = 44.295°. The diamond / copper composite material prepared through the preceding steps demonstrates excellent thermal conductivity, reaching 627.5 W / (m·K).

[0069] Comparative Example 1: In this comparative example, the tungsten-plated diamond was not subjected to reaction strengthening treatment.

[0070] (1) Use an ultrasonic cleaner to clean the raw diamond for 10 minutes to remove oil stains. The cleaning solution used consists of 20 g / L sodium hydroxide, 25 g / L sodium carbonate and 50 g / L detergent.

[0071] (2) The cleaned diamond was placed in a chemical etching solution and chemically etched for 6 hours at a temperature of 120°C using a magnetic stirring device. The chemical etching solution used consisted of 120 mL / L nitric acid and 450 mL / L sulfuric acid.

[0072] (3) Use magnetron sputtering equipment to perform tungsten coating on the surface of the chemically etched diamond. The magnetron sputtering power is 100W, the sputtering time is 40min, and the working pressure is 0.6Pa.

[0073] (4) Use PET double-sided tape to evenly attach the tungsten-plated diamond to the PP board.

[0074] (5) Place the PP plate with diamond attached in a magnetron sputtering equipment for magnetron sputtering copper layer treatment. The sputtering power is 90W, the time is 20min, and the working pressure is 0.6Pa.

[0075] (6) Connect the PP board with the sputtered copper layer to a DC power supply and place it in the copper plating solution for electroplating. The copper plating current density is 3A / dm³. 2 The electroplating time is 15 hours. The copper plating solution consists of 280 g / L copper sulfate, 80 g / L sulfuric acid, 0.035 g / L sodium chloride, 0.010 g / L sodium polydisulfide dipropane sulfonate, 0.030 g / L polyethylene glycol, and 2 mL / L brightener.

[0076] (7) Place the copper-clad PP board in a tube furnace for carbonization and degumming treatment. The carbonization temperature is 500℃ and the holding time is 2h. The atmosphere is hydrogen.

[0077] (8) Immerse the carbonized copper-clad PP board in an ethanol solution and use an ultrasonic cleaner for further degumming.

[0078] (9) The adhesive side of the debonded diamond / copper was subjected to single-sided copper electroplating for thickness enhancement, with a copper electroplating current density of 3A / dm². 2The electroplating time is 5 hours. After cleaning and drying, the diamond / copper composite material is obtained.

[0079] In the diamond / copper composite material prepared in the above comparative example, the diamonds are arranged regularly, but the coating on the diamond surface is severely damaged during the electroplating process, and the thermal conductivity is only 287.2 W / (m·K).

[0080] Comparative Example 2: In this comparative example, diamond / copper composite materials were prepared using powder metallurgy.

[0081] (1) Use an ultrasonic cleaner to clean the raw diamond for 10 minutes to remove oil stains. The cleaning solution used consists of 20 g / L sodium hydroxide, 25 g / L sodium carbonate and 50 g / L detergent.

[0082] (2) The cleaned diamond was placed in a chemical etching solution and chemically etched for 6 hours at a temperature of 120°C using a magnetic stirring device. The chemical etching solution used consisted of 120 mL / L nitric acid and 450 mL / L sulfuric acid.

[0083] (3) Use magnetron sputtering equipment to perform tungsten coating on the surface of the chemically etched diamond. The magnetron sputtering power is 100W, the sputtering time is 40min, and the working pressure is 0.6Pa.

[0084] (4) The diamond with tungsten coating on its surface is placed in a vacuum induction melting furnace for reaction strengthening treatment. The reaction temperature is 1100℃ and the time is 10min.

[0085] (5) Weigh the surface-modified diamond powder and electrolytic copper powder according to the component ratio, and use a planetary ball mill to mix them. The ball-to-material ratio is 1:3, the ball milling speed is 180 r / min, and the time is 4 h.

[0086] (6) Use a molding press to pre-press the uniformly mixed diamond / copper powder at a pressure of 18.5 MPa and a holding time of 5 min.

[0087] (7) The cold-pressed diamond / copper blank is placed in a spark plasma sintering furnace for sintering at a temperature of 970°C, a holding time of 10 min, and a pressure of 30 kN.

[0088] (8) The sintered sample is polished, cleaned and dried to obtain diamond / copper composite material.

[0089] The diamond / copper composite material prepared in the above comparative example has uneven diamond distribution and agglomeration, and its thermal conductivity is only 431.2 W / (m·K).

[0090] The diamond / copper composite materials obtained in the above embodiments and comparative examples are listed in Table 2:

[0091] Table 2 Comparison of Examples and Comparative Examples

[0092] Examples and Comparative Examples Properties of the obtained diamond / copper composite material Example 1 Diamonds are arranged in a regular single layer, exhibiting excellent thermal conductivity and thermal cycling performance. Example 2 Diamonds are arranged in a regular single layer, exhibiting excellent thermal conductivity and thermal cycling performance. Example 3 Diamonds are arranged in a regular single layer, exhibiting excellent thermal conductivity and thermal cycling performance. Comparative Example 1 Diamonds are arranged in a regular single layer, and their thermal conductivity is not as good as that of pure copper samples. Comparative Example 2 The diamonds are randomly arranged, and their thermal conductivity is slightly higher than that of the pure copper sample.

[0093] The preferred embodiments of this patent have been described in detail above. However, this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A method for preparing a diamond / copper composite material for heat dissipation of an electronic package, characterized by: The specific preparation steps are as follows: a) chemically eroding the raw material diamond and cleaning and drying; b) performing surface metallization treatment on the diamond obtained in step a); c) performing reaction strengthening treatment on the coating obtained in step b); d) uniformly pasting the diamond obtained in step c) on a substrate by using a vibrating screen and an adhesive; e) performing magnetron sputtering copper treatment on the substrate with the attached diamond obtained in step d); f) performing copper electroplating treatment on the substrate obtained in step e); g) performing stripping and degumming treatment on the diamond / copper layer obtained in step f); h) further electroplating thickening on the diamond / copper layer obtained in step g); and cleaning and drying to obtain a diamond / copper composite material.

2. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step a), the raw material diamond has a particle size of 300-500 μm and a nitrogen content of about 150 ppm; the chemical erosion treatment is soaking the diamond in a chemical erosion liquid for 6-8 h at a temperature of 120°C; and the chemical erosion liquid is a mixed liquid of nitric acid and sulfuric acid with a volume ratio of 1:3-1:

5.

3. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step b), the surface metallization treatment is magnetron sputtering treatment on the diamond, the coating is a strong carbide-forming element, the magnetron sputtering power is 80-125 W, the time is 30-60 min, and the working gas pressure is 0.2-0.7 Pa.

4. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step c), the reaction strengthening treatment temperature is 900-1100°C, and the time is 5-20 min.

5. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step d), the adhesive is PET double-sided adhesive, the substrate is one of a copper plate, a PP plate and a PET plate; and the pasting process utilizes a vibrating screen, the diamond particles are put into the vibrating screen with a mesh size slightly larger than the particle size of the diamond, the substrate with the double-sided adhesive is placed below the screen, and the substrate is slowly lowered so that the diamond particles fall uniformly on the substrate through the screen.

6. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step e), the magnetron sputtering treatment is magnetron sputtering copper, the sputtering power is 60-120 W, the time is 10-40 min, and the working gas pressure is 0.2-0.7 Pa.

7. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: The electroplating treatment of step f) is an electroplating embedding diamond treatment using a copper plating solution of acidic sulphate system, the electroplating copper current density being 2-10 A / dm 2 , the electroplating time being 5-15 h; the copper plating solution comprising copper sulphate, sulphuric acid, sodium chloride, sodium polydithiopropyl sulfone, polyethylene glycol and an appropriate brightener.

8. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step g), the degumming treatment is performed by using a tube furnace, the degumming temperature is 300-600°C, the holding time is 0.5-3 h, and the atmosphere is hydrogen.

9. The method for preparing a diamond / copper composite material for heat dissipation in electronic packaging according to claim 1, characterized in that: In step h), the electroplating thickening treatment is single-sided electroplating thickening on the copper layer on the previously glued side, the copper plating solution and the current density are the same as in step f), and the electroplating time is 2-5 h.

10. The diamond / copper composite material for electronic package heat dissipation prepared by the preparation method according to any one of claims 1-9, characterized in that: In the composite material, the diamond particle size is 300-500 μm, the diamond volume ratio is 35-50%, the diamond and copper are connected by carbide, the carbide layer thickness is less than 50 nm, the diamond particle size is 300-500 μm, the diamond volume ratio is 35-50%, and the material thermal conductivity is higher than 600 W / (m·K) and the thickness is less than 1 mm.

Images