Diamond-copper composite material for semiconductor and preparation method of diamond-copper composite material

Abstract

The invention relates to the field of diamond-copper composite materials, in particular to a diamond-copper composite material for a semiconductor and a preparation method of the diamond-copper composite material, and aims at solving the problems that the diamond-copper composite material is insufficient in interface bonding strength, uneven in diamond particle dispersion and poor in thermal expansion coefficient matching performance. Modified copper powder is added into a modified resin solution for ball milling, the surface of the copper powder is evenly coated with resin nanoparticles, then modified diamond is added, stirring continues, pressure maintaining is conducted on a hydraulic machine after drying, and then the diamond-copper composite material is obtained after sintering; the core effect of the modified resin solution is to fill micro-gaps, buffer stress and improve environment resistance, the modified diamond can solve the problem of surface inertia of the diamond, optimize interface compatibility and be efficiently combined with a copper matrix, and the core of the modified copper powder is to improve interface combination and thermal matching. And finally, the diamond-copper composite material has the properties of high heat conductivity, low thermal expansion and high interface bonding strength.

Description

Technical Field

[0001] This invention relates to the field of diamond-copper composite materials, and more specifically to a diamond-copper composite material for semiconductors and its preparation method. Background Technology

[0002] With the continuous innovation of semiconductor technology, the booming development of fields such as 5G communication, artificial intelligence, and electric vehicles is driving the rapid evolution of semiconductor devices towards high power and miniaturization. This trend has led to a sharp increase in power density per unit area, making it difficult for traditional heat dissipation materials to meet the heat dissipation requirements. Diamond-copper composite materials, with their synergistic properties of high thermal conductivity of diamond and high thermal conductivity of copper, have become an ideal choice for solving the heat dissipation problem of semiconductor devices. However, due to the limitations of existing manufacturing processes, there are still technical bottlenecks in practical applications, such as insufficient interfacial bonding strength, uneven dispersion of diamond particles, and poor matching of thermal expansion coefficients, which urgently need to be overcome through innovative processes.

[0003] Therefore, developing a diamond-copper composite material with high thermal conductivity, low thermal expansion, and high interfacial bonding strength has become an urgent problem to be solved in the industry. Summary of the Invention

[0004] In order to overcome the above-mentioned technical problems, the purpose of this invention is to provide a diamond-copper composite material for semiconductors and a method for preparing the same.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a diamond-copper composite material for semiconductors, comprising the following components in parts by weight: 55-66 parts of modified copper powder, 10-12 parts of modified resin solution, and 26-32 parts of modified diamond; The modified resin solution is prepared by the following steps: Step a1: Octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane and trifluoromethanesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred and reacted at 25-27℃ and 200-300 r / min for 24-26 h. After the reaction was completed, anhydrous sodium bicarbonate was added to the flask and stirred for 60-70 min. Then anhydrous sodium sulfate was added and stirred for another 60-70 min. The mixture was then allowed to stand for 30-35 min, filtered to remove the precipitate, and the filtrate was then rotary evaporated at 40-50℃. The filtrate was then placed in a vacuum drying oven and dried at 40-50℃ for 6-7 h to obtain the first intermediate. Step a2: Add p-allylphenol, platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution, and toluene to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and constant-pressure dropping funnel. Purge with nitrogen for protection and stir the reaction at 25-27°C and a stirring rate of 200-300 r / min for 15-17 min. Then raise the temperature to 75-80°C and add the first intermediate / toluene solution to the constant-pressure dropping funnel. Add the mixture dropwise to the flask while stirring, controlling the dropping rate at 1-2 drops / s. After the addition is complete, raise the temperature to 95-100℃ and continue stirring for 20-24 hours. After the reaction is complete, perform rotary evaporation at 60-70℃. Then, extract the upper layer solution with n-hexane 3-4 times to remove the upper layer solution. Then, perform rotary evaporation again at 50-60℃. After that, place it in a vacuum drying oven and dry it at 50-60℃ for 8-10 hours to obtain the second intermediate. Step a3: The second intermediate, epichlorohydrin, and tetrabutylammonium bromide are added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas is introduced for protection, and the mixture is stirred at 75-80℃ and 200-300 r / min for 6-7 h. After cooling to room temperature, sodium hydroxide solution is added, and the mixture is stirred at 45-50℃ for 4-5 h. After the reaction is complete, the system is dissolved in dichloromethane and washed 3-4 times with deionized water. Anhydrous magnesium sulfate is added to the organic phase and dried for 2-3 h. The mixture is then filtered, and the filtrate is rotary evaporated at 40-50℃. After drying, the filtrate is placed in a vacuum drying oven at 45-55℃ for 10-12 h to obtain a siloxane modified resin containing epoxy groups. Step a4: Dissolve the epoxy group-containing siloxane-modified resin in anhydrous ethanol, add γ-aminopropyltriethoxysilane, and stir the reaction at a temperature of 55-60℃ and a stirring rate of 200-300 r / min for 60-70 min. Then place the solution in an ultrasonic cell disruptor and treat it at a power of 270-300W for 30-35 min to obtain the modified resin solution.

[0006] In a preferred embodiment of the present invention, the ratio of the amounts of octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane, trifluoromethanesulfonic acid, anhydrous sodium bicarbonate, and anhydrous sodium sulfate in step a1 is 5.9-6.8g: 38.5-44.4g: 1.3-1.5g: 0.17-0.19g: 1.0-1.3g: 5.6-8.4g.

[0007] In a preferred embodiment of the present invention, the ratio of p-allylphenol, platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution, toluene, and the first intermediate / toluene solution in step a2 is 36.5-38.4 g : 0.037-0.039 mL : 14.4-15.1 mL : 25-27 mL.

[0008] In a preferred embodiment of the present invention, the platinum content of the platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution in step a2 is 1%.

[0009] In a preferred embodiment of the present invention, the first intermediate / toluene solution in step a2 is a solution formed by mixing the first intermediate and toluene in a ratio of 13g:14mL.

[0010] In a preferred embodiment of the present invention, the ratio of the second intermediate, epichlorohydrin, tetrabutylammonium bromide, sodium hydroxide solution, dichloromethane, and anhydrous magnesium sulfate in step a3 is 21-23g: 170-185g: 2.9-3.1g: 12.5-13.5mL: 300-400mL: 50-80g.

[0011] In a preferred embodiment of the present invention, the sodium hydroxide solution in step a3 has a mass fraction of 40%.

[0012] In a preferred embodiment of the present invention, the ratio of the epoxy group-containing siloxane-modified resin, anhydrous ethanol and γ-aminopropyltriethoxysilane used in step a4 is 2-3g: 10-15mL: 0.02-0.03g.

[0013] The modified diamond is prepared by the following steps: Step b1: Place diamond particles in a polytetrafluoroethylene beaker, add concentrated sulfuric acid-concentrated nitric acid mixture, and place in a constant temperature water bath at 80℃. Stir at a stirring rate of 250-300 r / min for 2-3 hours. After the reaction is complete, ultrasonically clean with deionized water at a power of 270-300W for 10-12 minutes, repeating the cleaning 3-4 times. Then, ultrasonically disperse in anhydrous ethanol for 15-18 minutes. Finally, place in a vacuum drying oven and dry at 55-60℃ for 4-5 hours to obtain pretreated diamond. Step b2: Disperse the pretreated diamond in a graphite tray, place it in the vacuum chamber of the magnetron sputtering instrument, close the vacuum chamber, and evacuate to 5 × 10⁻⁶. -4Pa, argon gas is introduced, and the flow rate is adjusted to stabilize the vacuum chamber pressure at 0.8 Pa. Then, the sputtering parameters are set, and sputtering is performed for 15-30 min under the conditions of titanium target power of 180-200 W, sample stage rotation speed of 9-10 r / min, and substrate temperature of 190-200℃. After sputtering, the power is turned off, argon gas is continued to be introduced, and the furnace is cooled to room temperature to obtain titanium-coated diamond. Step b3: Deionized water, nickel sulfate, sodium hypophosphite, and sodium citrate are added sequentially to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas is introduced for protection. The mixture is stirred for 15-20 minutes at a temperature of 25-30℃ and a stirring rate of 300-500 r / min. The pH is adjusted to 5.0-5.5 with 25% ammonia. The mixture is then placed in a constant temperature water bath at 85℃. Titanium-coated diamond is added to the mixture, and the mixture is stirred for 30-60 minutes at a stirring rate of 150-180 r / min. After the reaction, the mixture is ultrasonically cleaned with deionized water at a power of 170-200W for 5-6 minutes, and cleaned 3 times. The mixture is then placed in a vacuum drying oven and dried at a temperature of 55-60℃ for 6-7 hours. After drying, the mixture is passed through a 100-mesh sieve to obtain modified diamond.

[0014] In a preferred embodiment of the present invention, the ratio of diamond particles, concentrated sulfuric acid-concentrated nitric acid mixture and anhydrous ethanol in step b1 is 32-34g: 160-170mL: 160-170mL.

[0015] In a preferred embodiment of the present invention, the concentrated sulfuric acid-concentrated nitric acid mixture in step b1 is a solution formed by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; and the mass fraction of the concentrated nitric acid is 65%.

[0016] In a preferred embodiment of the present invention, the diamond particles in step b1 have a particle size of 80-100 μm and a purity of ≥99.9%.

[0017] In a preferred embodiment of the present invention, the titanium target in step b2 has a size of Φ50mm×5mm and a purity of ≥99.95%.

[0018] In a preferred embodiment of the present invention, the thickness of the titanium layer in step b2 is 20-50 nm.

[0019] In a preferred embodiment of the present invention, the ratio of deionized water, nickel sulfate, sodium hypophosphite, sodium citrate and titanium-coated diamond in step b3 is 255-290 mL: 25-29 g: 30-35 g: 15-17 g: 32-37 g.

[0020] In a preferred embodiment of the present invention, the thickness of the nickel-phosphorus layer in step b3 is 30-50 nm.

[0021] The modified copper powder is prepared by the following steps: Copper powder, titanium powder, niobium powder, and anhydrous ethanol were added to a planetary ball mill, along with agate balls at a ratio of 10:1. The mixture was ball-milled for 4-4.2 hours under argon protection at a speed of 280-300 r / min. After milling, the mixture was placed in a vacuum drying oven and dried at 55-60℃ for 8-9 hours. The dried mixture was then passed through a 200-mesh sieve to obtain modified copper powder.

[0022] In a preferred embodiment of the present invention, the ratio of copper powder, titanium powder, niobium powder and anhydrous ethanol is 65-68g: 0.66-0.69g: 0.33-0.35g: 66-70mL.

[0023] In a preferred embodiment of the present invention, the copper powder has a particle size of 5-8 μm and a purity of ≥99.95%; the titanium powder has a particle size of 1-3 μm and a purity of ≥99.9%; and the niobium powder has a particle size of 1-3 μm and a purity of ≥99.9%.

[0024] Secondly, this application provides a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step 1: Add modified copper powder to the modified resin solution and stir in a planetary ball mill at a speed of 170-200 r / min for 60-70 min. Add agate balls with a ball-to-material ratio of 5:1, then add modified diamond, and continue stirring at a speed of 130-150 r / min for 30-35 min. Then place it in a vacuum drying oven and dry at a temperature of 60-65℃ for 6-7 h. After drying, granulate through a 100-mesh sieve to obtain composite powder. Step 2: Load the composite powder into a graphite mold, apply a pressure of 50 MPa on a hydraulic press, hold the pressure for 5 minutes, then place it in a vacuum hot pressing sintering furnace. First, heat the powder to 250°C at a heating rate of 5°C / min and hold for 60-65 minutes. Then, heat the powder to 600°C at a heating rate of 10°C / min and hold for 30-35 minutes. Finally, heat the powder to 900°C at a heating rate of 5°C / min while applying a pressure of 40 MPa and hold for 30-35 minutes. Then, cool the powder to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material.

[0025] The beneficial effects of this invention are: This invention discloses a semiconductor diamond-copper composite material and its preparation method. The method involves ball milling modified copper powder into a modified resin solution to uniformly coat the copper powder surface with resin nanoparticles. Modified diamond is then added and the mixture is stirred continuously. After drying, the mixture is pressed on a hydraulic press and sintered to obtain the diamond-copper composite material. The sintering process involves three heating steps: the first heating causes the epoxy groups in the resin to react with the hydroxyl groups and nickel-phosphorus plating on the copper surface, achieving initial solidification and preventing subsequent flow; the second heating further solidifies the resin, and the decomposed carbon dioxide, water vapor, and other gases are expelled through a vacuum to prevent pore formation; the third heating melts the copper powder to fill the gaps, and titanium and niobium react with carbon on the diamond surface to form a titanium carbide / niobium carbide transition layer. The core function of the modified resin solution is to fill micropores, buffer stress, and improve environmental resistance. The modified diamond overcomes the surface inertness of diamond, optimizes interfacial compatibility, and achieves efficient bonding with the copper matrix. The core function of the modified copper powder is to improve interfacial bonding and thermal compatibility, ultimately giving the diamond-copper composite material high thermal conductivity, low thermal expansion, and high interfacial bonding strength.

[0026] In the preparation of diamond-copper composite materials, a modified resin solution was first prepared. The initial step involved the ring-opening polymerization of cyclosiloxanes. Trifluoromethanesulfonic acid was used as a catalyst to catalyze the ring-opening of octamethylcyclotetrasiloxane and 2,4,6,8-tetramethylcyclotetrasiloxane, and 1,1,3,3-tetramethyldisiloxane was used as a chain terminator to introduce Si-H bonds. Anhydrous sodium bicarbonate neutralized the catalyst, and anhydrous sodium sulfate was used to dry the system and remove moisture, ultimately yielding a polysiloxane oligomer containing Si-H bonds. Following this was a hydrosilylation reaction. Under the catalysis of a platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution, the Si-H bonds of the first intermediate added to the C=C bonds of p-allylphenol, grafting the phenolic hydroxyl groups onto the polysiloxane backbone. Hexane extraction removed unreacted p-allylphenol, yielding a polysiloxane containing phenolic hydroxyl groups. Then, tetrabutylammonium bromide was used as a catalyst... The phenolic hydroxyl group in the second intermediate undergoes a ring-opening reaction with epibromopropane, followed by a ring-closing reaction under the action of sodium hydroxide, ultimately introducing epoxy groups into the molecular chain to obtain a siloxane resin containing epoxy groups. Finally, a silane coupling agent is used to improve the compatibility of the resin with metal / diamond, resulting in a modified resin solution. The epoxy groups in the resin molecule can undergo ring-opening reactions with the hydroxyl groups on the copper surface and the phosphorus groups in the diamond nickel-phosphorus coating to form chemical bonds. At the same time, the amino groups of the silane coupling agent crosslink with the epoxy groups of the resin and the hydroxyl groups on the diamond surface, filling the micropores at the material interface, further improving the interfacial bonding strength, and reducing the thermal resistance loss caused by the pores. The siloxane resin backbone has excellent flexibility and is uniformly distributed at the copper-diamond interface, which can buffer the thermal expansion mismatch stress of the material, suppress microcracks, improve the environmental stability of the material, and adapt to complex semiconductor scenarios.

[0027] In the preparation of diamond-copper composite materials, a modified diamond was prepared. First, the diamond was added to a mixture of concentrated sulfuric acid and concentrated nitric acid to remove surface graphite impurities and simultaneously etch the surface to form nanoscale pits, increasing the contact area for subsequent coatings. Then, a titanium layer was plated onto the diamond. The titanium slowly reacts with the carbon on the diamond surface to form a titanium carbide transition layer, which forms a strong chemical bond with the diamond. Finally, a nickel-phosphorus layer was chemically plated onto the diamond, and sodium hypophosphite was used to bond the Ni... 2+ It is reduced to Ni, and at the same time, it oxidizes itself to provide phosphorus, forming an amorphous nickel-phosphorus layer; the strong chemical bonding of titanium carbide ensures that diamond is not easily pulled out of the copper substrate under stress, thus improving mechanical reliability. The nickel-phosphorus coating can improve the wettability of copper to diamond, buffer the reaction rate of titanium, niobium and carbon in copper with diamond, and prevent excessive growth of titanium carbide.

[0028] In the preparation of diamond-copper composite materials, a modified copper powder was prepared. First, copper powder, titanium powder, and niobium powder were ball-milled. Through mechanical force, titanium and niobium particles were uniformly dispersed on the surface of the copper powder to obtain titanium- and niobium-doped copper powder. Titanium is an active metal that diffuses to the diamond surface during sintering, penetrates the nickel-phosphorus coating on the diamond surface, and reacts with the carbon and titanium coating on the diamond surface to form strong chemical bonds of titanium carbide, which can improve the interfacial bonding strength. Niobium plays the role of regulating the coefficient of thermal expansion and inhibiting the excessive growth of titanium carbide. The two work together to improve the interfacial bonding and thermal matching. Titanium and niobium, as heterogeneous nucleation sites, can inhibit the coarsening of copper grains during sintering and improve the density and thermal conductivity of the material. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0030] This embodiment describes a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step s1: 5.9 g of octamethylcyclotetrasiloxane, 38.5 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 1.3 g of 1,1,3,3-tetramethyldisiloxane, and 0.17 g of trifluoromethanesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 25 °C and a stirring rate of 200 r / min for 24 h. After the reaction was completed, 1.0 g of anhydrous sodium bicarbonate was added to the flask and stirred for 60 min. Then, 5.6 g of anhydrous sodium sulfate was added and the mixture was stirred for another 60 min. After standing for 30 min, the precipitate was removed by filtration. The filtrate was then rotary evaporated at 40 °C and then placed in a vacuum drying oven and dried at 40 °C for 6 h to obtain the first intermediate. Step s2: 36.5 g of p-allylphenol, 0.037 mL of platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution (the platinum content of the platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution is 1%) and 14.4 mL of toluene were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and constant pressure dropping funnel. Nitrogen gas was introduced for protection, and the reaction was stirred for 15 min at 25 °C and a stirring rate of 200 r / min. Then the temperature was raised to 75 °C, and 25 mL of the first intermediate / methyl A benzene solution (the first intermediate / toluene solution is a mixture of the first intermediate and toluene in a molar ratio of 13g:14mL) was added to a constant pressure dropping funnel, and then added dropwise to a flask while stirring, with a dropping rate of 1 drop / s. After the addition was complete, the temperature was raised to 95℃, and the reaction was stirred for 20 hours. After the reaction was completed, the mixture was rotary evaporated at 60℃. The upper layer was then extracted three times with n-hexane to remove the upper layer. The lower layer was then rotary evaporated again at 50℃. The mixture was then placed in a vacuum drying oven and dried at 50℃ for 8 hours to obtain the second intermediate. Step s3: 21g of the second intermediate, 170g of epichlorohydrin and 2.9g of tetrabutylammonium bromide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 75℃ and 200r / min for 6h. After cooling to room temperature, 12.5mL of 40% sodium hydroxide solution was added, and the mixture was stirred at 45℃ for another 4h. After the reaction was completed, the system was dissolved in 300mL of dichloromethane and washed three times with deionized water. 50g of anhydrous magnesium sulfate was added to the organic phase and dried for 2h. The mixture was then filtered, and the filtrate was rotary evaporated at 40℃. After drying, the filtrate was placed in a vacuum drying oven and dried at 45℃ for 10h to obtain a siloxane modified resin containing epoxy groups. Step s4: Dissolve 2g of epoxy group-containing siloxane-modified resin in 10mL of anhydrous ethanol, add 0.02g of γ-aminopropyltriethoxysilane, and stir the reaction at 55℃ and 200r / min for 60min. Then place the solution in an ultrasonic cell disruptor and treat it at 270W for 30min to obtain the modified resin solution. Step s5: Place 32g of diamond particles (diamond particle size 80μm, purity ≥99.9%) into a polytetrafluoroethylene beaker, add 160mL of concentrated sulfuric acid-concentrated nitric acid mixture (concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; the mass fraction of the concentrated nitric acid is 65%), place in a constant temperature water bath at 80℃, and stir for 2h at a stirring rate of 250r / min. After the reaction is completed, ultrasonically clean with deionized water at a power of 270W for 10min, clean 3 times, then ultrasonically disperse in 160mL of anhydrous ethanol for 15min, and then place in a vacuum drying oven and dry at a temperature of 55℃ for 4h to obtain pretreated diamond. Step s6: Disperse 32g of pretreated diamond in a graphite tray, place it in the vacuum chamber of the magnetron sputtering instrument, close the vacuum chamber, and evacuate to 5×10⁻⁶. -4 Argon gas was introduced and the flow rate was adjusted to stabilize the vacuum chamber pressure at 0.8 Pa. Then, sputtering parameters were set, and sputtering was performed for 15 min under the following conditions: titanium target (size Φ50mm×5mm, purity ≥99.95%) power 180W, sample stage speed 9r / min, and substrate temperature 190℃. After sputtering, the power was turned off, argon gas was continued to be introduced, and the furnace was cooled to room temperature to obtain titanium-coated diamond. Step s7: 255 mL of deionized water, 25 g of nickel sulfate, 30 g of sodium hypophosphite, and 15 g of sodium citrate were added sequentially to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred for 15 min at 25 °C and a stirring rate of 300 r / min. The pH was adjusted to 5.0 with 25% ammonia water, and the mixture was placed in a constant temperature water bath at 85 °C. 32 g of titanium-coated diamond was added to the mixture, and the mixture was stirred for 30 min at a stirring rate of 150 r / min. After the reaction was completed, the mixture was ultrasonically cleaned with deionized water at a power of 170 W for 5 min, and cleaned 3 times. Then, it was placed in a vacuum drying oven and dried at 55 °C for 6 h. After drying, it was passed through a 100-mesh sieve to obtain modified diamond. Step s8: Add 65g of copper powder (particle size of 5μm, purity ≥99.95%), 0.66g of titanium powder (particle size of 1μm, purity ≥99.9%), 0.33g of niobium powder (particle size of 1μm, purity ≥99.9%), and 66mL of anhydrous ethanol to a planetary ball mill. Add agate balls with a ball-to-particle ratio of 10:1. Under argon protection, ball mill at 280r / min for 4h. Then place in a vacuum drying oven and dry at 55℃ for 8h. After drying, pass through a 200-mesh sieve to obtain modified copper powder. Step s9: Add 55 parts of modified copper powder to 10 parts of modified resin solution, stir in a planetary ball mill at 170 r / min for 60 min, add agate balls with a ball-to-material ratio of 5:1, then add 26 parts of modified diamond, continue stirring at 130 r / min for 30 min, then place in a vacuum drying oven and dry at 60℃ for 6 h, granulate through a 100-mesh sieve to obtain composite powder; Step s10: 95 parts of composite powder were loaded into a graphite mold, and a pressure of 50 MPa was applied on a hydraulic press and held for 5 min. Then, the mold was placed in a vacuum hot pressing sintering furnace. The temperature was first raised to 250°C at a heating rate of 5°C / min and held for 60 min. Then, the temperature was raised to 600°C at a heating rate of 10°C / min and held for 30 min. Finally, the temperature was raised to 900°C at a heating rate of 5°C / min, while a pressure of 40 MPa was applied and held for 30 min. The temperature was then lowered to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material. Example 2:

[0031] This embodiment describes a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step s1: 6.4 g of octamethylcyclotetrasiloxane, 41.4 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 1.4 g of 1,1,3,3-tetramethyldisiloxane and 0.18 g of trifluoromethanesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 26 °C and 250 r / min for 25 h. After the reaction was completed, 1.2 g of anhydrous sodium bicarbonate was added to the flask and stirred for 65 min. Then 7 g of anhydrous sodium sulfate was added and stirred for another 65 min. After standing for 33 min, the precipitate was removed by filtration. The filtrate was then rotary evaporated at 45 °C and then placed in a vacuum drying oven and dried at 45 °C for 6.5 h to obtain the first intermediate. Step s2: 37.5 g of p-allylphenol, 0.038 mL of platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution (the platinum content of the platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution is 1%) and 14.8 mL of toluene were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and constant pressure dropping funnel. Nitrogen gas was introduced for protection, and the mixture was stirred for 16 min at 26 °C and a stirring rate of 250 r / min. Then the temperature was raised to 78 °C, and 26 mL of the first intermediate / methyl... A benzene solution (the first intermediate / toluene solution is a mixture of the first intermediate and toluene in a molar ratio of 13g:14mL) was added to a constant pressure dropping funnel, and then added dropwise to a flask while stirring, with the dropping rate controlled at 1 drop / s. After the addition was complete, the temperature was raised to 98℃, and the reaction was continued to be stirred for 22h. After the reaction was completed, the mixture was rotary evaporated at 65℃. The upper layer solution was then extracted three times with n-hexane to remove the upper layer solution. The lower layer solution was then rotary evaporated again at 55℃. The mixture was then placed in a vacuum drying oven and dried at 55℃ for 9h to obtain the second intermediate. Step s3: 22g of the second intermediate, 178g of epichlorohydrin and 3g of tetrabutylammonium bromide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 78℃ and 250r / min for 6.5h. After cooling to room temperature, 13mL of 40% sodium hydroxide solution was added. The mixture was stirred at 48℃ for another 4.5h. After the reaction was completed, the system was dissolved in 350mL of dichloromethane and washed three times with deionized water. 65g of anhydrous magnesium sulfate was added to the organic phase and dried for 2.5h. The mixture was then filtered. The filtrate was rotary evaporated at 45℃ and then placed in a vacuum drying oven and dried at 50℃ for 11h to obtain a siloxane modified resin containing epoxy groups. Step s4: Dissolve 2.5g of epoxy group-containing siloxane-modified resin in 13mL of anhydrous ethanol, add 0.025g of γ-aminopropyltriethoxysilane, and stir the reaction at 58℃ and 250r / min for 65min. Then place the solution in an ultrasonic cell disruptor and treat it at 280W for 33min to obtain the modified resin solution. Step s5: Place 33g of diamond particles (diamond particle size 90μm, purity ≥99.9%) into a polytetrafluoroethylene beaker, add 165mL of concentrated sulfuric acid-concentrated nitric acid mixture (concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; the mass fraction of the concentrated nitric acid is 65%), place in a constant temperature water bath at 80℃, and stir for 2.5h at a stirring rate of 270r / min. After the reaction is completed, ultrasonically clean with deionized water at a power of 280W for 11min, clean 3 times, then ultrasonically disperse in 165mL of anhydrous ethanol for 17min, and then place in a vacuum drying oven at 58℃ for 4.5h to obtain pretreated diamond. Step s6: Disperse 33g of pretreated diamond in a graphite tray, place it in the vacuum chamber of the magnetron sputtering instrument, close the vacuum chamber, and evacuate to 5×10⁻⁶. -4 Argon gas was introduced and the flow rate was adjusted to stabilize the vacuum chamber pressure at 0.8 Pa. Then, sputtering parameters were set, and sputtering was performed for 23 min under the following conditions: titanium target (size Φ50mm×5mm, purity ≥99.95%) power 190W, sample stage speed 9r / min, and substrate temperature 195℃. After sputtering, the power was turned off, argon gas was continued to be introduced, and the furnace was cooled to room temperature to obtain titanium-coated diamond. Step s7: 275 mL of deionized water, 27 g of nickel sulfate, 33 g of sodium hypophosphite, and 16 g of sodium citrate were added sequentially to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred for 17 min at 27 °C and a stirring rate of 400 r / min. The pH was adjusted to 5.3 with 25% ammonia water, and the mixture was placed in a constant temperature water bath at 85 °C. 35 g of titanium-coated diamond was added to the mixture, and the mixture was stirred for 45 min at a stirring rate of 165 r / min. After the reaction was completed, the mixture was ultrasonically cleaned with deionized water at a power of 180 W for 5.5 min, and cleaned 3 times. Then, it was placed in a vacuum drying oven and dried at 58 °C for 6.5 h. After drying, it was passed through a 100-mesh sieve to obtain modified diamond. Step s8: Add 66g of copper powder (particle size of 7μm, purity ≥99.95%), 0.67g of titanium powder (particle size of 2μm, purity ≥99.9%), 0.34g of niobium powder (particle size of 2μm, purity ≥99.9%), and 68mL of anhydrous ethanol to a planetary ball mill. Add agate balls with a ball-to-particle ratio of 10:1. Under argon protection, ball mill at a speed of 290r / min for 4.1h. Then place in a vacuum drying oven and dry at 58℃ for 8.5h. After drying, pass through a 200-mesh sieve to obtain modified copper powder. Step s9: Add 60 parts of modified copper powder to 11 parts of modified resin solution, stir in a planetary ball mill at 190 r / min for 65 min, add agate balls with a ball-to-material ratio of 5:1, then add 29 parts of modified diamond, continue stirring at 140 r / min for 33 min, then place in a vacuum drying oven and dry at 63℃ for 6.5 h, granulate through a 100 mesh sieve to obtain composite powder; Step s10: 97 parts of composite powder were loaded into a graphite mold, and a pressure of 50 MPa was applied on a hydraulic press and held for 5 min. Then, the mold was placed in a vacuum hot pressing sintering furnace. The temperature was first raised to 250°C at a heating rate of 5°C / min and held for 63 min. Then, the temperature was raised to 600°C at a heating rate of 10°C / min and held for 33 min. Finally, the temperature was raised to 900°C at a heating rate of 5°C / min, while a pressure of 40 MPa was applied and held for 33 min. The temperature was then lowered to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material. Example 3:

[0032] This embodiment describes a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step s1: 6.8g of octamethylcyclotetrasiloxane, 44.4g of 2,4,6,8-tetramethylcyclotetrasiloxane, 1.5g of 1,1,3,3-tetramethyldisiloxane and 0.19g of trifluoromethanesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 27°C and 300r / min for 26h. After the reaction was completed, 1.3g of anhydrous sodium bicarbonate was added to the flask and stirred for 70min. Then 8.4g of anhydrous sodium sulfate was added and stirred for another 70min. After standing for 35min, the precipitate was removed by filtration. The filtrate was then rotary evaporated at 50°C and then placed in a vacuum drying oven and dried at 50°C for 7h to obtain the first intermediate. Step s2: 38.4 g of p-allylphenol, 0.039 mL of platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution (the platinum content of the platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution is 1%) and 15.1 mL of toluene were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and constant pressure dropping funnel. Nitrogen gas was introduced for protection, and the reaction was stirred for 17 min at 27 °C and a stirring rate of 300 r / min. Then the temperature was raised to 80 °C, and 27 mL of the first intermediate / toluene was added. The solution (the first intermediate / toluene solution is a solution prepared by mixing the first intermediate and toluene in a molar ratio of 13g:14mL) was added to a constant pressure dropping funnel, and then added dropwise to a flask while stirring, with the dropping rate controlled at 2 drops / s. After the addition was completed, the temperature was raised to 100℃, and the reaction was continued to be stirred for 24h. After the reaction was completed, the solution was rotary evaporated at 70℃. Then, the upper layer was extracted with n-hexane four times to remove the upper layer solution. The lower layer solution was then rotary evaporated again at 60℃. After that, it was placed in a vacuum drying oven and dried at 60℃ for 10h to obtain the second intermediate. Step s3: 23g of the second intermediate, 185g of epichlorohydrin and 3.1g of tetrabutylammonium bromide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 80℃ and 300r / min for 7h. After cooling to room temperature, 13.5mL of 40% sodium hydroxide solution was added, and the mixture was stirred at 50℃ for another 5h. After the reaction was completed, the system was dissolved in 400mL of dichloromethane and washed 4 times with deionized water. 80g of anhydrous magnesium sulfate was added to the organic phase and dried for 3h. The mixture was then filtered, and the filtrate was rotary evaporated at 50℃. After drying, the filtrate was placed in a vacuum drying oven and dried at 55℃ for 12h to obtain a siloxane modified resin containing epoxy groups. Step s4: Dissolve 3g of epoxy group-containing siloxane-modified resin in 15mL of anhydrous ethanol, add 0.03g of γ-aminopropyltriethoxysilane, and stir the reaction at 60℃ and 300r / min for 70min. Then place the solution in an ultrasonic cell disruptor and treat it at 300W for 35min to obtain the modified resin solution. Step s5: Place 34g of diamond particles (diamond particle size 100μm, purity ≥99.9%) into a polytetrafluoroethylene beaker, add 170mL of concentrated sulfuric acid-concentrated nitric acid mixture (concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; the mass fraction of the concentrated nitric acid is 65%), place in a constant temperature water bath at 80℃, and stir for 3h at a stirring rate of 300r / min. After the reaction is completed, ultrasonically clean with deionized water at a power of 300W for 12min, clean 4 times, then ultrasonically disperse in 170mL of anhydrous ethanol for 18min, and then place in a vacuum drying oven and dry at 60℃ for 5h to obtain pretreated diamond. Step s6: Disperse 34g of pretreated diamond in a graphite tray, place it in the vacuum chamber of the magnetron sputtering instrument, close the vacuum chamber, and evacuate to 5×10⁻⁶. -4 Argon gas was introduced and the flow rate was adjusted to stabilize the vacuum chamber pressure at 0.8 Pa. Then, sputtering parameters were set, and sputtering was performed for 30 min under the following conditions: titanium target (size Φ50mm×5mm, purity ≥99.95%) power 200W, sample stage speed 10r / min, and substrate temperature 200℃. After sputtering, the power was turned off, argon gas was continued to be introduced, and the furnace was cooled to room temperature to obtain titanium-coated diamond. Step s7: 290 mL of deionized water, 29 g of nickel sulfate, 35 g of sodium hypophosphite, and 17 g of sodium citrate were added sequentially to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 30 °C and a stirring rate of 500 r / min for 20 min. The pH was adjusted to 5.5 with 25% ammonia water, and the mixture was placed in a constant temperature water bath at 85 °C. 37 g of titanium-coated diamond was added to the mixture, and the mixture was stirred at a stirring rate of 180 r / min for 60 min. After the reaction was completed, the mixture was ultrasonically cleaned with deionized water at a power of 200 W for 6 min, and cleaned 3 times. Then, it was placed in a vacuum drying oven and dried at 60 °C for 7 h. After drying, it was passed through a 100-mesh sieve to obtain modified diamond. Step s8: Add 68g of copper powder (particle size of copper powder is 8μm, purity ≥99.95%), 0.69g of titanium powder (particle size of titanium powder is 3μm, purity ≥99.9%), 0.35g of niobium powder (particle size of niobium powder is 3μm, purity ≥99.9%) and 70mL of anhydrous ethanol to a planetary ball mill, add agate balls with a ball-to-particle ratio of 10:1, and ball mill for 4.2h at 300r / min under argon protection. Then place it in a vacuum drying oven and dry it at 60℃ for 9h. After drying, pass it through a 200-mesh sieve to obtain modified copper powder. Step s9: Add 66 parts of modified copper powder to 12 parts of modified resin solution, stir in a planetary ball mill at 200 r / min for 70 min, add agate balls with a ball-to-material ratio of 5:1, then add 32 parts of modified diamond, continue stirring at 150 r / min for 35 min, then place in a vacuum drying oven and dry at 65℃ for 7 h, granulate through a 100-mesh sieve to obtain composite powder; Step s10: 100 parts of composite powder are loaded into a graphite mold, and a pressure of 50 MPa is applied on a hydraulic press and held for 5 min. Then, the mold is placed in a vacuum hot pressing sintering furnace. The temperature is first raised to 250°C at a heating rate of 5°C / min and held for 65 min. Then, the temperature is raised to 600°C at a heating rate of 10°C / min and held for 35 min. Finally, the temperature is raised to 900°C at a heating rate of 5°C / min while applying a pressure of 40 MPa and holding for 35 min. The temperature is then lowered to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material.

[0033] Comparative Example 1: This comparative example illustrates a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step s1: 5.9 g of octamethylcyclotetrasiloxane, 38.5 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 1.3 g of 1,1,3,3-tetramethyldisiloxane, and 0.17 g of trifluoromethanesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 25 °C and a stirring rate of 200 r / min for 24 h. After the reaction was completed, 1.0 g of anhydrous sodium bicarbonate was added to the flask and stirred for 60 min. Then, 5.6 g of anhydrous sodium sulfate was added and the mixture was stirred for another 60 min. After standing for 30 min, the precipitate was removed by filtration. The filtrate was then rotary evaporated at 40 °C and then placed in a vacuum drying oven and dried at 40 °C for 6 h to obtain the first intermediate. Step s2: 36.5 g of p-allylphenol, 0.037 mL of platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution (the platinum content of the platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution is 1%) and 14.4 mL of toluene were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and constant pressure dropping funnel. Nitrogen gas was introduced for protection, and the reaction was stirred for 15 min at 25 °C and a stirring rate of 200 r / min. Then the temperature was raised to 75 °C, and 25 mL of the first intermediate / methyl A benzene solution (the first intermediate / toluene solution is a mixture of the first intermediate and toluene in a molar ratio of 13g:14mL) was added to a constant pressure dropping funnel, and then added dropwise to a flask while stirring, with a dropping rate of 1 drop / s. After the addition was complete, the temperature was raised to 95℃, and the reaction was stirred for 20 hours. After the reaction was completed, the mixture was rotary evaporated at 60℃. The upper layer was then extracted three times with n-hexane to remove the upper layer. The lower layer was then rotary evaporated again at 50℃. The mixture was then placed in a vacuum drying oven and dried at 50℃ for 8 hours to obtain the second intermediate. Step s3: 21g of the second intermediate, 170g of epichlorohydrin and 2.9g of tetrabutylammonium bromide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 75℃ and 200r / min for 6h. After cooling to room temperature, 12.5mL of 40% sodium hydroxide solution was added, and the mixture was stirred at 45℃ for another 4h. After the reaction was completed, the system was dissolved in 300mL of dichloromethane and washed three times with deionized water. 50g of anhydrous magnesium sulfate was added to the organic phase and dried for 2h. The mixture was then filtered, and the filtrate was rotary evaporated at 40℃. After drying, the filtrate was placed in a vacuum drying oven and dried at 45℃ for 10h to obtain a siloxane modified resin containing epoxy groups. Step s4: Dissolve 2g of epoxy group-containing siloxane-modified resin in 10mL of anhydrous ethanol, add 0.02g of γ-aminopropyltriethoxysilane, and stir the reaction at 55℃ and 200r / min for 60min. Then place the solution in an ultrasonic cell disruptor and treat it at 270W for 30min to obtain the modified resin solution. Step s5: Place 32g of diamond particles (diamond particle size 80μm, purity ≥99.9%) into a polytetrafluoroethylene beaker, add 160mL of concentrated sulfuric acid-concentrated nitric acid mixture (concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; the mass fraction of the concentrated nitric acid is 65%), place in a constant temperature water bath at 80℃, and stir for 2h at a stirring rate of 250r / min. After the reaction is completed, ultrasonically clean with deionized water at a power of 270W for 10min, clean 3 times, then ultrasonically disperse in 160mL of anhydrous ethanol for 15min, and then place in a vacuum drying oven and dry at a temperature of 55℃ for 4h to obtain pretreated diamond. Step s6: Add 55 parts of copper powder to 10 parts of modified resin solution, stir in a planetary ball mill at 170 r / min for 60 min, add agate balls with a ball-to-material ratio of 5:1, then add 26 parts of pretreated diamond, continue stirring at 130 r / min for 30 min, then place in a vacuum drying oven and dry at 60℃ for 6 h, granulate through a 100-mesh sieve to obtain composite powder; Step s7: 95 parts of composite powder were loaded into a graphite mold, and a pressure of 50 MPa was applied on a hydraulic press and held for 5 min. Then, the mold was placed in a vacuum hot pressing sintering furnace. The temperature was first raised to 250°C at a heating rate of 5°C / min and held for 60 min. Then, the temperature was raised to 600°C at a heating rate of 10°C / min and held for 30 min. Finally, the temperature was raised to 900°C at a heating rate of 5°C / min, while a pressure of 40 MPa was applied and held for 30 min. The temperature was then lowered to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material.

[0034] Comparative Example 2: This comparative example illustrates a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step s1: 5.9 g of octamethylcyclotetrasiloxane, 38.5 g of 2,4,6,8-tetramethylcyclotetrasiloxane, 1.3 g of 1,1,3,3-tetramethyldisiloxane, and 0.17 g of trifluoromethanesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 25 °C and a stirring rate of 200 r / min for 24 h. After the reaction was completed, 1.0 g of anhydrous sodium bicarbonate was added to the flask and stirred for 60 min. Then, 5.6 g of anhydrous sodium sulfate was added and the mixture was stirred for another 60 min. After standing for 30 min, the precipitate was removed by filtration. The filtrate was then rotary evaporated at 40 °C and then placed in a vacuum drying oven and dried at 40 °C for 6 h to obtain the first intermediate. Step s2: 36.5 g of p-allylphenol, 0.037 mL of platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution (the platinum content of the platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution is 1%) and 14.4 mL of toluene were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and constant pressure dropping funnel. Nitrogen gas was introduced for protection, and the reaction was stirred for 15 min at 25 °C and a stirring rate of 200 r / min. Then the temperature was raised to 75 °C, and 25 mL of the first intermediate / methyl A benzene solution (the first intermediate / toluene solution is a mixture of the first intermediate and toluene in a molar ratio of 13g:14mL) was added to a constant pressure dropping funnel, and then added dropwise to a flask while stirring, with a dropping rate of 1 drop / s. After the addition was complete, the temperature was raised to 95℃, and the reaction was stirred for 20 hours. After the reaction was completed, the mixture was rotary evaporated at 60℃. The upper layer was then extracted three times with n-hexane to remove the upper layer. The lower layer was then rotary evaporated again at 50℃. The mixture was then placed in a vacuum drying oven and dried at 50℃ for 8 hours to obtain the second intermediate. Step s3: 21g of the second intermediate, 170g of epichlorohydrin and 2.9g of tetrabutylammonium bromide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 75℃ and 200r / min for 6h. After cooling to room temperature, 12.5mL of 40% sodium hydroxide solution was added, and the mixture was stirred at 45℃ for another 4h. After the reaction was completed, the system was dissolved in 300mL of dichloromethane and washed three times with deionized water. 50g of anhydrous magnesium sulfate was added to the organic phase and dried for 2h. The mixture was then filtered, and the filtrate was rotary evaporated at 40℃. After drying, the filtrate was placed in a vacuum drying oven and dried at 45℃ for 10h to obtain a siloxane modified resin containing epoxy groups. Step s4: Dissolve 2g of epoxy group-containing siloxane-modified resin in 10mL of anhydrous ethanol, add 0.02g of γ-aminopropyltriethoxysilane, and stir the reaction at 55℃ and 200r / min for 60min. Then place the solution in an ultrasonic cell disruptor and treat it at 270W for 30min to obtain the modified resin solution. Step s5: Place 32g of diamond particles (diamond particle size 80μm, purity ≥99.9%) into a polytetrafluoroethylene beaker, add 160mL of concentrated sulfuric acid-concentrated nitric acid mixture (concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; the mass fraction of the concentrated nitric acid is 65%), place in a constant temperature water bath at 80℃, and stir for 2h at a stirring rate of 250r / min. After the reaction is completed, ultrasonically clean with deionized water at a power of 270W for 10min, clean 3 times, then ultrasonically disperse in 160mL of anhydrous ethanol for 15min, and then place in a vacuum drying oven and dry at a temperature of 55℃ for 4h to obtain pretreated diamond. Step s6: Disperse 32g of pretreated diamond in a graphite tray, place it in the vacuum chamber of the magnetron sputtering instrument, close the vacuum chamber, and evacuate to 5×10⁻⁶. -4 Argon gas was introduced and the flow rate was adjusted to stabilize the vacuum chamber pressure at 0.8 Pa. Then, sputtering parameters were set, and sputtering was performed for 15 min under the following conditions: titanium target (size Φ50mm×5mm, purity ≥99.95%) power 180W, sample stage speed 9r / min, and substrate temperature 190℃. After sputtering, the power was turned off, argon gas was continued to be introduced, and the furnace was cooled to room temperature to obtain titanium-coated diamond. Step s7: 255 mL of deionized water, 25 g of nickel sulfate, 30 g of sodium hypophosphite, and 15 g of sodium citrate were added sequentially to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred for 15 min at 25 °C and a stirring rate of 300 r / min. The pH was adjusted to 5.0 with 25% ammonia water, and the mixture was placed in a constant temperature water bath at 85 °C. 32 g of titanium-coated diamond was added to the mixture, and the mixture was stirred for 30 min at a stirring rate of 150 r / min. After the reaction was completed, the mixture was ultrasonically cleaned with deionized water at a power of 170 W for 5 min, and cleaned 3 times. Then, it was placed in a vacuum drying oven and dried at 55 °C for 6 h. After drying, it was passed through a 100-mesh sieve to obtain modified diamond. Step s8: Add 55 parts of copper powder to 10 parts of modified resin solution, stir in a planetary ball mill at 170 r / min for 60 min, add agate balls with a ball-to-material ratio of 5:1, then add 26 parts of modified diamond, continue stirring at 130 r / min for 30 min, then place in a vacuum drying oven and dry at 60℃ for 6 h, granulate through a 100-mesh sieve to obtain composite powder; Step s9: 95 parts of composite powder were loaded into a graphite mold, and a pressure of 50 MPa was applied on a hydraulic press and held for 5 min. Then, the mold was placed in a vacuum hot pressing sintering furnace. The temperature was first raised to 250°C at a heating rate of 5°C / min and held for 60 min. Then, the temperature was raised to 600°C at a heating rate of 10°C / min and held for 30 min. Finally, the temperature was raised to 900°C at a heating rate of 5°C / min, while a pressure of 40 MPa was applied and held for 30 min. The temperature was then lowered to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material.

[0035] Comparative Example 3: This comparative example illustrates a method for preparing a diamond-copper composite material for semiconductors, comprising the following steps: Step s1: Place 32g of diamond particles (diamond particle size 80μm, purity ≥99.9%) into a polytetrafluoroethylene beaker, add 160mL of concentrated sulfuric acid-concentrated nitric acid mixture (concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of the concentrated sulfuric acid is 98%; the mass fraction of the concentrated nitric acid is 65%), place in a constant temperature water bath at 80℃, and stir for 2h at a stirring rate of 250r / min. After the reaction is completed, ultrasonically clean with deionized water at a power of 270W for 10min, clean 3 times, then ultrasonically disperse in 160mL of anhydrous ethanol for 15min, and then place in a vacuum drying oven and dry at a temperature of 55℃ for 4h to obtain pretreated diamond. Step s2: Disperse 32g of pretreated diamond in a graphite tray, place it in the vacuum chamber of the magnetron sputtering instrument, close the vacuum chamber, and evacuate to 5×10⁻⁶. -4 Argon gas was introduced and the flow rate was adjusted to stabilize the vacuum chamber pressure at 0.8 Pa. Then, sputtering parameters were set, and sputtering was performed for 15 min under the following conditions: titanium target (size Φ50mm×5mm, purity ≥99.95%) power 180W, sample stage speed 9r / min, and substrate temperature 190℃. After sputtering, the power was turned off, argon gas was continued to be introduced, and the furnace was cooled to room temperature to obtain titanium-coated diamond. Step s3: 255 mL of deionized water, 25 g of nickel sulfate, 30 g of sodium hypophosphite, and 15 g of sodium citrate were added sequentially to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 25 °C and a stirring rate of 300 r / min for 15 min. The pH was adjusted to 5.0 with 25% ammonia water, and the mixture was placed in a constant temperature water bath at 85 °C. 32 g of titanium-coated diamond was added to the mixture, and the mixture was stirred at a stirring rate of 150 r / min for 30 min. After the reaction was completed, the mixture was ultrasonically cleaned with deionized water at a power of 170 W for 5 min, and cleaned 3 times. Then, it was placed in a vacuum drying oven and dried at 55 °C for 6 h. After drying, it was passed through a 100-mesh sieve to obtain modified diamond. Step s4: Add 65g of copper powder (particle size of 5μm, purity ≥99.95%), 0.66g of titanium powder (particle size of 1μm, purity ≥99.9%), 0.33g of niobium powder (particle size of 1μm, purity ≥99.9%), and 66mL of anhydrous ethanol to a planetary ball mill. Add agate balls with a ball-to-particle ratio of 10:1. Under argon protection, ball mill at 280r / min for 4h. Then place in a vacuum drying oven and dry at 55℃ for 8h. After drying, pass through a 200-mesh sieve to obtain modified copper powder. Step s5: Add 55 parts of modified copper powder to 10 parts of anhydrous ethanol and stir in a planetary ball mill at a speed of 170 r / min for 60 min. Add agate balls with a ball-to-material ratio of 5:1, then add 26 parts of modified diamond and continue stirring at a speed of 130 r / min for 30 min. Then place it in a vacuum drying oven and dry at a temperature of 60℃ for 6 h. After drying, granulate through a 100-mesh sieve to obtain composite powder. Step s6: 95 parts of composite powder were loaded into a graphite mold, and a pressure of 50 MPa was applied on a hydraulic press and held for 5 min. Then, the mold was placed in a vacuum hot pressing sintering furnace. The temperature was first raised to 250°C at a heating rate of 5°C / min and held for 60 min. Then, the temperature was raised to 600°C at a heating rate of 10°C / min and held for 30 min. Finally, the temperature was raised to 900°C at a heating rate of 5°C / min, while a pressure of 40 MPa was applied and held for 30 min. The temperature was then lowered to room temperature at a cooling rate of 5°C / min to obtain the diamond-copper composite material.

[0036] Performance testing Thermal conductivity was tested using the laser flash method. The diamond-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were processed into discs with a diameter of 10 mm × 2 mm. The surface was polished with a diamond wheel to a roughness of Ra ≤ 0.1 μm. Under room temperature conditions, the laser pulse energy was 5 J and the detector response time was ≤ 1 μs. The thermal diffusivity (α) was calculated by testing the temperature change curve of the back side of the sample over time. Combined with the density (ρ) and specific heat capacity (c), the thermal conductivity was calculated according to the formula λ = α × ρ × c. The coefficient of thermal expansion was tested using thermomechanical analysis. The diamond-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were processed into rectangular specimens of 5mm×5mm×20mm. The two ends were fixed to the sample holder with high-temperature adhesive. The temperature range was -50 to 200℃, the heating rate was 5℃ / min, and the change in sample length with temperature was recorded under a nitrogen atmosphere. The average coefficient of linear expansion (CTE) was calculated. To test the interfacial shear strength, modified diamond particles from Examples 1-3 and Comparative Examples 1-3 were embedded in incompletely cured epoxy resin, with the exposed portion height approximately half the particle size. After curing, a micron-sized probe was used to apply a horizontal tensile force on a universal testing machine until the diamond particles were pulled out of the resin. The maximum tensile force (F) was recorded, and the interfacial shear strength was calculated using the formula τ=F / (π×d×h) (where d is the diamond particle size and h is the exposed height). The loading rate was 0.5 μm / s, and the accuracy was ±1 μN. For flexural strength testing, the diamond-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were processed into cuboid specimens of 3mm × 4mm × 30mm, with polished surfaces free of cracks. The span was 20mm, and the loading rate was 0.5mm / min. The maximum load (F) at fracture was recorded, and the strength was calculated using the formula σ = 3FL / (2bh). 2 Calculate the flexural strength (L is the span, b is the specimen width, and h is the thickness). The test results are shown in the table below:

[0037] Referring to the table above, based on the comparison between Examples 1-3 and Comparative Examples 1-3, it can be seen that the diamond-copper composite material has properties such as high thermal conductivity, low thermal expansion, and high interfacial bonding strength.

[0038] Based on the comparison between Example 1 and Comparative Example 1, it can be seen that modified diamond can solve the surface inertia of diamond, optimize interface compatibility, and efficiently bond with the copper matrix. The core of modified copper powder is to improve interface bonding and thermal matching. That is, the diamond-copper composite material prepared by modified diamond, modified copper powder and modified resin solution has better performance than the diamond-copper composite material prepared by diamond, copper powder and modified resin solution.

[0039] Based on the comparison between Example 1 and Comparative Example 2, it can be seen that the diamond-copper composite material prepared from modified diamond, modified copper powder and modified resin solution has better performance than the diamond-copper composite material prepared from modified diamond, copper powder and modified resin solution.

[0040] Based on the comparison between Example 1 and Comparative Example 3, it can be seen that the core function of the modified resin solution is to fill micro-voids, buffer stress, and improve environmental resistance. Modified diamond can solve the surface inertness of diamond, optimize interface compatibility, and efficiently combine with the copper matrix. That is, the diamond-copper composite material prepared by modified diamond, modified copper powder and modified resin solution has better performance than the diamond-copper composite material prepared by modified diamond, modified copper powder and anhydrous ethanol.

[0041] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A diamond-copper composite material for semiconductors, characterized in that, Includes the following components by weight: 55-66 parts of modified copper powder, 10-12 parts of modified resin solution, and 26-32 parts of modified diamond; The modified resin solution is prepared by the following steps: Step a1: Octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane and trifluoromethanesulfonic acid were stirred and reacted. Anhydrous sodium bicarbonate was added and stirred, followed by anhydrous sodium sulfate and stirred. The mixture was allowed to stand, filtered, and then evaporated by rotary evaporation and dried to obtain the first intermediate. Step a2: The p-allylphenol, platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution and toluene were stirred and reacted. The first intermediate / toluene solution was added dropwise and stirred. The mixture was then rotary evaporated, extracted, and then rotary evaporated again and dried to obtain the second intermediate. Step a3: The second intermediate, epichlorohydrin and tetrabutylammonium bromide are stirred and reacted, cooled, sodium hydroxide solution is added, poured into dichloromethane, washed, dried with anhydrous magnesium sulfate and filtered, rotary evaporated and dried to obtain siloxane modified resin containing epoxy groups. Step a4: Dissolve the epoxy group-containing siloxane-modified resin in anhydrous ethanol, add γ-aminopropyltriethoxysilane, stir, and sonicate to obtain a modified resin solution.

2. The diamond-copper composite material for semiconductors according to claim 1, characterized in that, The ratio of octamethylcyclotetrasiloxane, 2,4,6,8-tetramethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane, trifluoromethanesulfonic acid, anhydrous sodium bicarbonate, and anhydrous sodium sulfate in step a1 is 5.9-6.8g: 38.5-44.4g: 1.3-1.5g: 0.17-0.19g: 1.0-1.3g: 5.6-8.4g.

3. The diamond-copper composite material for semiconductors according to claim 1, characterized in that, In step a2, the ratio of p-allylphenol, platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution, toluene, and the first intermediate / toluene solution is 36.5-38.4 g : 0.037-0.039 mL : 14.4-15.1 mL : 25-27 mL; the platinum content of the platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex solution is 1%; the first intermediate / toluene solution is a solution of the first intermediate and toluene mixed in a ratio of 13 g : 14 mL.

4. The diamond-copper composite material for semiconductors according to claim 1, characterized in that, In step a3, the ratio of the second intermediate, epichlorohydrin, tetrabutylammonium bromide, sodium hydroxide solution, dichloromethane, and anhydrous magnesium sulfate is 21-23g: 170-185g: 2.9-3.1g: 12.5-13.5mL: 300-400mL: 50-80g; the sodium hydroxide solution has a mass fraction of 40%.

5. The diamond-copper composite material for semiconductors according to claim 1, characterized in that, In step a4, the ratio of the epoxy group-containing siloxane-modified resin, anhydrous ethanol, and γ-aminopropyltriethoxysilane is 2-3g: 10-15mL: 0.02-0.03g.

6. The diamond-copper composite material for semiconductors according to claim 1, characterized in that, The modified diamond is prepared by the following steps: Step b1: The diamond particles and concentrated sulfuric acid-concentrated nitric acid mixture are stirred and reacted, then ultrasonically cleaned, ultrasonically dispersed in anhydrous ethanol, and then dried to obtain pretreated diamond. Step b2: Disperse the pretreated diamond in a graphite tray, place it in the vacuum chamber of a magnetron sputtering instrument, set the sputtering parameters, sputter with a titanium target, cool, and obtain titanium-coated diamond. Step b3: Deionized water, nickel sulfate, sodium hypophosphite and sodium citrate are stirred and reacted in sequence. The pH is adjusted with 25% ammonia water, the temperature is raised, titanium-coated diamond is added and stirred, ultrasonically cleaned, dried and sieved to obtain modified diamond.

7. The diamond-copper composite material for semiconductors according to claim 6, characterized in that, In step b1, the ratio of diamond particles, concentrated sulfuric acid-concentrated nitric acid mixture, and anhydrous ethanol is 32-34g:160-170mL:160-170mL; the concentrated sulfuric acid-concentrated nitric acid mixture is a solution of concentrated sulfuric acid and concentrated nitric acid mixed in a volume ratio of 3:1; the mass fraction of concentrated sulfuric acid is 98%; the mass fraction of concentrated nitric acid is 65%; the particle size of the diamond particles is 80-100μm, and the purity is ≥99.9%; in step b2, the size of the titanium target is Φ50mm×5mm, and the purity is ≥99.95%; the thickness of the titanium coating is 20-50nm; in step b3, the ratio of deionized water, nickel sulfate, sodium hypophosphite, sodium citrate, and titanium-coated diamond is 255-290mL:25-29g:30-35g:15-17g:32-37g; the thickness of the nickel-phosphorus layer is 30-50nm.

8. The diamond-copper composite material for semiconductors according to claim 1, characterized in that, The modified copper powder is prepared by the following steps: Copper powder, titanium powder, niobium powder, and anhydrous ethanol were added to a planetary ball mill and ball-milled, then dried and sieved to obtain modified copper powder.

9. The diamond-copper composite material for semiconductors according to claim 8, characterized in that, The ratio of copper powder, titanium powder, niobium powder, and anhydrous ethanol is 65-68g: 0.66-0.69g: 0.33-0.35g: 66-70mL; the copper powder has a particle size of 5-8μm and a purity ≥99.95%; the titanium powder has a particle size of 1-3μm and a purity ≥99.9%; and the niobium powder has a particle size of 1-3μm and a purity ≥99.9%.

10. A method for preparing a diamond-copper composite material for semiconductors, characterized in that, The method for preparing a diamond-copper composite material for semiconductors as described in any one of claims 1-9 comprises the following steps: Step 1: Add modified copper powder to modified resin solution, stir in planetary ball mill, then add modified diamond and continue stirring, then dry, sieve and granulate to obtain composite powder; Step 2: The composite powder is loaded into a graphite mold, pressure is applied on a hydraulic press and maintained, and then placed in a vacuum hot pressing sintering furnace for sintering and cooling to obtain a diamond-copper composite material.

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