Manufacturing process of radiating fin capable of improving radiating efficiency

Abstract

The invention discloses a manufacturing process of a cooling fin capable of improving cooling efficiency, and belongs to the technical field of cooling fin manufacturing. Comprising the following steps: taking a graphite substrate, and uniformly depositing a molybdenum metal layer on the surface of the graphite substrate by adopting magnetron sputtering; performing diamond micro-powder deposition on the graphite matrix deposited with molybdenum, and then stripping the graphite matrix through heat treatment to obtain a diamond diaphragm; coating the surface of the diamond diaphragm with an etching agent, pressing and shaping to form an etching agent layer, transferring into a vacuum furnace for heat treatment, taking out and cooling to obtain the diamond diaphragm subjected to heat treatment; and carrying out copper plating treatment to obtain the cooling fin. The europium, manganese and niobium doped iron-based metal etchant with a synergistic effect is introduced to uniformly corrode a diamond grain boundary, so that the bonding performance of a copper and diamond interface is improved, and the radiating fin with an excellent radiating effect is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat sink manufacturing, and particularly relates to a manufacturing process of a heat sink for improving heat dissipation efficiency. Background Art

[0002] With the continuous progress of technology, electronic products are developing rapidly towards more integrated, miniaturized and intelligent directions, and this trend puts more stringent requirements on the performance of thermal management materials. Among many thermal management materials, diamond / copper composites have attracted much attention due to their unique properties. However, the existing diamond film / copper composites are formed by compounding diamond micropowder and copper at the same time. This composite material has advantages such as high thermal conductivity, adjustable thermal expansion coefficient, and electrical insulation. However, during the preparation process, although there are dangling bonds on the carbon atoms on the surface of diamond crystals, generally the dangling bonds of these carbon atoms self-couple and close with the dangling bonds of adjacent carbon atoms, or adsorb gas atoms in the surrounding air to form a stable low-free energy surface. This leads to the interfacial energy between diamond and conventional metals or alloys being higher than the surface energy of diamond, and then results in the difficulty of wetting of metals or alloys on the diamond surface, resulting in poor wettability of copper on the diamond surface. Limited by the bonding state between diamond and copper, copper is difficult to fully diffuse and form uniform adhesion, resulting in insufficient bonding force between the two. Insufficient bonding force will cause heat flow to be blocked at the interface, reducing the effective transfer of heat, which will reduce the overall thermal conductivity of the composite material and affect its performance in heat dissipation applications. Summary of the Invention

[0003] The purpose of the present invention is to provide a manufacturing process of a heat sink for improving heat dissipation efficiency, so as to solve the technical problem of low thermal conductivity caused by insufficient interfacial bonding force between diamond and copper.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A manufacturing process of a heat sink for improving heat dissipation efficiency includes the following steps:

[0006] S1. Take a graphite substrate, and uniformly deposit a molybdenum metal layer on the surface of the graphite substrate by magnetron sputtering;

[0007] S2. After cleaning the graphite substrate deposited with molybdenum by ultrasonic cleaning and drying it, subject the dried graphite substrate to diamond micropowder deposition by using multifunctional microwave plasma chemical vapor deposition treatment, and then through heat treatment, peel off the graphite substrate to obtain a diamond film sheet;

[0008] S3. Take the diamond diaphragm and polish one of its surfaces. Uniformly coat the polished surface of the diamond diaphragm with an etchant, place it flat with the side coated with the etchant facing up, press and shape it to form an etchant layer, transfer it to a vacuum furnace for heat treatment, take it out and cool it to obtain the heat-treated diamond diaphragm;

[0009] S4. Take the heat-treated diamond diaphragm, remove the residual etchant on its surface, and perform copper plating treatment to obtain the heat sink.

[0010] As a preferred technical solution of the present invention, the preparation method of the etchant includes the following steps:

[0011] A1. Take ferric nitrate nonahydrate and dilute nitric acid solution, stir for 15 - 25 min, add potassium hydroxide solution, stir for 30 - 40 min, perform centrifugal separation, take the solid phase, wash it, and dry it to obtain material A;

[0012] A2. Take europium(III) nitrate hexahydrate and dilute nitric acid solution, stir for 15 - 25 min, add potassium hydroxide solution, stir for 30 - 40 min, perform centrifugal separation, take the solid phase, wash it, and dry it to obtain material B;

[0013] A3. Take manganese(II) acetate and dilute nitric acid solution, stir for 15 - 25 min, add potassium hydroxide solution, stir for 30 - 40 min, perform centrifugal separation, take the solid phase, wash it, and dry it to obtain material C;

[0014] A4. Take material A, material B, material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate, perform ultrasonic dispersion for 25 - 35 min, transfer it to the inner lining of a 100 mL polytetrafluoroethylene reaction kettle, seal and heat it, cool it, and discharge it to obtain the etchant.

[0015] As a preferred technical solution of the present invention, in step A1, the dosage ratio of ferric nitrate nonahydrate, dilute nitric acid solution, and potassium hydroxide solution is 241.4 - 243.6 mg: 10 mL: 25 - 35 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L.

[0016] As a preferred technical solution of the present invention, in step A2, the dosage ratio of europium(III) nitrate hexahydrate, dilute nitric acid solution, and potassium hydroxide solution is 258.7 - 258.9 mg: 10 mL: 25 - 35 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L.

[0017] As a preferred technical solution of the present invention, in step A3, the dosage ratio of manganese acetate, dilute nitric acid solution, and potassium hydroxide solution is 7.608 - 7.612 mg: 10 mL: 25 - 35 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L.

[0018] As a preferred technical solution of the present invention, in step A4, the dosage ratio of material A, material B, material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate is 120.7 - 121.8 mg: 129.3 - 129.4 mg: 3.804 - 3.806 mg: 20 - 30 mL: 9.985 - 9.986 mg; the concentration of the potassium hydroxide solution is 12 mol / L; the sealed heating means heating at 200 °C under sealed conditions for 20 - 30 h.

[0019] As a preferred technical solution of the present invention, in step S3, the vacuum degree for heat treatment in the vacuum furnace is 3×10-4 Pa, the temperature is 880 - 1020 °C, and the time is 1 - 2 h.

[0020] As a preferred technical solution of the present invention, in step S1, the thickness of the molybdenum metal layer is 2 - 3 μm.

[0021] As a preferred technical solution of the present invention, in step S3, the thickness of the etchant layer is 200 - 300 nm.

[0022] As a preferred technical solution of the present invention, in step S4, the copper plating thickness is 0.32 - 0.48 mm.

[0023] Advantages of the present invention:

[0024] The manufacturing process of a heat sink for improving heat dissipation efficiency disclosed by the present invention uniformly corrodes the diamond grain boundaries by introducing an iron-based metal etchant doped with europium, manganese, and niobium with a synergistic effect, improves the bonding performance at the copper-diamond interface, and thus obtains a heat sink with excellent heat dissipation effect. Detailed implementation manners

[0025] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with embodiments, details the specific implementation manners, structures, features, and their effects of the present invention as follows.

[0026] Example 1

[0027] A manufacturing process of a heat sink for improving heat dissipation efficiency includes the following steps:

[0028] S1. Take a graphite substrate in the shape of a cuboid with a specification of 10 mm in length, 10 mm in width, and 1.5 mm in height, and use magnetron sputtering to uniformly deposit a molybdenum metal layer with a thickness of 2 μm on the surface of the graphite substrate;

[0029] The magnetron sputtering operation is an operation method well-known to those skilled in the art, and specifically includes the following steps:

[0030] Put the graphite substrate into the magnetron sputtering chamber, install the molybdenum target at the sputtering source, keep the target-substrate distance constant at 15 cm, the base table rotation speed at 3 r / min, adjust the chamber pressure to 3×10 -3 Pa, then introduce argon at 80 sccm, stabilize the pressure at 0.8 Pa, use a DC power supply to excite glow discharge, set the constant power at 200 W, and the deposition time at 2 h;

[0031] S2. After cleaning the graphite substrate deposited with molybdenum ultrasonically and drying it, use the graphite substrate after drying for diamond micropowder deposition by multifunctional microwave plasma chemical vapor deposition treatment, and then through heat treatment, peel off the graphite substrate to obtain a diamond film;

[0032] The diamond micropowder deposition operation is an operation method well-known to those skilled in the art, and specifically includes the following steps: Place the cleaned sample in the exact middle of the base of the multifunctional microwave plasma chemical vapor deposition equipment, and pump the air pressure in the chamber to 0.1 kPa through a mechanical pump. Then open the hydrogen gas valve, introduce hydrogen with a flow rate of 400 sccm, the pressure gradually rises, when the pressure rises to 0.8 kPa, ignite to provide an input power of 0.6 kW, and then the pressure gradually rises to 18 kPa. During this period, slowly increase the power to 6 kW. At this time, introduce methane with a flow rate of 15 sccm, the deposition temperature is 860 °C, and the deposition time is 24 h;

[0033] S3. Take the diamond film and polish one side surface, uniformly coat an etchant on the surface of the polished diamond film, place the side with the etchant coated facing up and press it for shaping to form an etchant layer with a thickness of 200 nm, transfer it to a vacuum furnace for heat treatment, take it out and cool it to obtain a heat-treated diamond film;

[0034] The vacuum degree for heat treatment in the vacuum furnace is 3×10 -4 Pa, the temperature is 880 °C, and the time is 1 h;

[0035] The preparation method of the etchant includes the following steps:

[0036] A1. Mix ferric nitrate nonahydrate and dilute nitric acid solution, stir for 15 min, add potassium hydroxide solution, stir for 30 min, centrifuge and separate, take the solid phase, wash and dry to obtain Material A; the dosage ratio of ferric nitrate nonahydrate, dilute nitric acid solution, and potassium hydroxide solution is 241.4 mg: 10 mL: 25 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0037] A2. Mix europium nitrate hexahydrate and dilute nitric acid solution, stir for 15 min, add potassium hydroxide solution, stir for 30 min, centrifuge and separate, take the solid phase, wash and dry to obtain Material B; the dosage ratio of ferric nitrate nonahydrate, dilute nitric acid solution, and potassium hydroxide solution is 258.7 mg: 10 mL: 25 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0038] A3. Mix manganese acetate and dilute nitric acid solution, stir for 15 min, add potassium hydroxide solution, stir for 30 min, centrifuge and separate, take the solid phase, wash and dry to obtain Material C; the dosage ratio of manganese acetate, dilute nitric acid solution, and potassium hydroxide solution is 7.608 mg: 10 mL: 25 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0039] A4. Mix Material A, Material B, Material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate, ultrasonically disperse for 25 min, transfer to a 100 mL polytetrafluoroethylene reaction kettle liner, seal and heat, cool, and discharge to obtain the etchant; the dosage ratio of Material A, Material B, Material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate is 120.7 mg: 129.3 mg: 3.804 mg: 20 mL: 9.985 mg; the concentration of the potassium hydroxide solution is 12 mol / L; the sealed heating refers to heating at 200 °C under sealed conditions for 20 h;

[0040] S4. Remove the residual etchant on the surface of the heat-treated diamond film, and perform copper plating treatment to obtain the heat sink;

[0041] The copper plating treatment operation is an operation method well-known to those skilled in the art. Specifically, it means placing the diamond film after removing the etchant as the cathode in the copper plating solution, using a phosphorus copper plate as the anode correspondingly, placing the copper plating solution on a magnetic stirring table and stirring while depositing metallic copper on the surface of the diamond film at room temperature using a DC regulated power supply. The constant current electroplating method is adopted, with the current set at a constant 0.2 A and the current density at 2 A / dm 2 , for 24 h, and the thickness of the electroplated copper is 0.32 mm;

[0042] The copper electroplating solution was purchased from Sigma-Aldrich Corporation in the United States, and it is a high-speed bright copper electroplating solution with the catalog number 900569.

[0043] The heat sink prepared in Example 1 was measured using a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments), and its thermal conductivity was 716 W / (m·K).

[0044] Example 2

[0045] A manufacturing process for a heat sink to improve heat dissipation efficiency includes the following steps:

[0046] S1. Take a cuboid-shaped graphite substrate with specifications of length 10 mm, width 10 mm, and height 1.5 mm, and use magnetron sputtering to uniformly deposit a molybdenum metal layer with a thickness of 2.5 μm on the surface of the graphite substrate.

[0047] The magnetron sputtering operation is an operation method well-known to those skilled in the art, and specifically includes the following steps:

[0048] Put the graphite substrate into the magnetron sputtering chamber, install the molybdenum target at the sputtering source, keep the target-substrate distance constantly at 15 cm, the base rotation speed at 3 r / min, adjust the chamber pressure to 3×10 -3 Pa, then introduce argon at 80 sccm, stabilize the pressure at 0.8 Pa, use a DC power supply to excite glow discharge, set the constant power at 200 W, and the deposition time at 2.5 h.

[0049] S2. After ultrasonically cleaning and drying the graphite substrate deposited with molybdenum, use the graphite substrate after drying for diamond micropowder deposition by multi-functional microwave plasma chemical vapor deposition treatment, and then through heat treatment, peel off the graphite substrate to obtain a diamond film.

[0050] The diamond micropowder deposition operation is an operation method well-known to those skilled in the art, and specifically includes the following steps: Place the cleaned sample in the exact middle of the base of the multi-functional microwave plasma chemical vapor deposition equipment, and pump the pressure in the chamber to 0.1 kPa through a mechanical pump. Then open the hydrogen gas valve and introduce hydrogen at a flow rate of 400 sccm. The pressure gradually rises. When the pressure rises to 0.8 kPa, ignite to provide an input power of 0.6 kW, and then the pressure gradually rises to 18 kPa. During this period, slowly increase the power to 6 kW. At this time, introduce methane at a flow rate of 15 sccm, the deposition temperature is 860 °C, and the deposition time is 24 h.

[0051] S3. Take the diamond diaphragm and polish one of its surfaces. Uniformly coat the surface of the polished diamond diaphragm with an etchant, place it flat with the side coated with the etchant facing up, press and shape it to form an etchant layer with a thickness of 250 nm, transfer it to a vacuum furnace for heat treatment, take it out and cool it to obtain the heat-treated diamond diaphragm;

[0052] The vacuum degree for heat treatment in the vacuum furnace is 3×10 -4 Pa, the temperature is 950 °C, and the time is 1.5 h;

[0053] The preparation method of the etchant includes the following steps:

[0054] A1. Take ferric nitrate nonahydrate and dilute nitric acid solution, stir for 20 min, add potassium hydroxide solution, stir for 35 min, centrifuge and separate, take the solid phase, wash and dry it to obtain material A; the dosage ratio of ferric nitrate nonahydrate, dilute nitric acid solution, and potassium hydroxide solution is 242.5 mg: 10 mL: 30 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0055] A2. Take europium nitrate hexahydrate and dilute nitric acid solution, stir for 20 min, add potassium hydroxide solution, stir for 35 min, centrifuge and separate, take the solid phase, wash and dry it to obtain material B; the dosage ratio of europium nitrate hexahydrate, dilute nitric acid solution, and potassium hydroxide solution is 258.8 mg: 10 mL: 30 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0056] A3. Take manganese acetate and dilute nitric acid solution, stir for 20 min, add potassium hydroxide solution, stir for 35 min, centrifuge and separate, take the solid phase, wash and dry it to obtain material C; the dosage ratio of manganese acetate, dilute nitric acid solution, and potassium hydroxide solution is 7.610 mg: 10 mL: 30 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0057] A4. Take material A, material B, material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate, ultrasonically disperse for 30 min, transfer to a 100 mL polytetrafluoroethylene reaction kettle liner, seal and heat, cool, and discharge to obtain the etchant; the dosage ratio of material A, material B, material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate is 121.2 mg: 129.35 mg: 3.805 mg: 25 mL: 9.9855 mg; the concentration of the potassium hydroxide solution is 12 mol / L; the sealed heating refers to heating at 200 °C under sealed conditions for 25 h;

[0058] S4. Remove the residual etchant on the surface of the heat-treated diamond diaphragm, and perform copper plating treatment to obtain the heat sink.

[0059] The copper plating treatment operation is an operation method well-known to those skilled in the art. Specifically, it means placing the diamond diaphragm after removing the etchant as the cathode in the copper electroplating solution, and correspondingly using a phosphor copper plate as the anode. Place the copper electroplating solution on a magnetic stirring table and stir while depositing metallic copper on the surface of the diamond diaphragm at room temperature using a DC regulated power supply. Adopt the constant current electroplating method, set the current to be constant at 0.2 A, the time to be 28 h, and the electroplated copper thickness to be 0.40 mm.

[0060] The copper electroplating solution is purchased from Sigma-Aldrich Corporation in the United States, and it is a high-speed bright copper electroplating solution with the product number 900569.

[0061] The heat sink prepared in Example 2 was measured using a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments), and its thermal conductivity was 723 W / (m·K).

[0062] Example 3

[0063] A manufacturing process for a heat sink to improve heat dissipation efficiency includes the following steps:

[0064] S1. Take a cuboid-shaped graphite substrate with specifications of length 10 mm, width 10 mm, and height 1.5 mm, and use magnetron sputtering to uniformly deposit a molybdenum metal layer with a thickness of 3 μm on the surface of the graphite substrate.

[0065] The magnetron sputtering operation is an operation method well-known to those skilled in the art, and specifically includes the following steps:

[0066] Place the graphite substrate into the magnetron sputtering chamber, install the molybdenum target at the sputtering source, keep the target-substrate distance constant at 15 cm, the base rotation speed at 3 r / min, adjust the chamber pressure to 3×10 -3 Pa, then introduce argon at 80 sccm, stabilize the pressure at 0.8 Pa, use a DC power supply to excite glow discharge, set the constant power to 200 W, and the deposition time to 3 h.

[0067] S2. After the graphite substrate deposited with molybdenum is ultrasonically cleaned and dried, use the diamond micropowder deposition by multifunctional microwave plasma chemical vapor deposition treatment, and then through heat treatment, peel off the graphite substrate to obtain a diamond diaphragm.

[0068] The diamond micropowder deposition operation is an operation method well-known to those skilled in the art, and specifically includes the following steps: Place the cleaned specimen in the exact middle of the substrate of the multifunctional microwave plasma chemical vapor deposition equipment, and use a mechanical pump to pump the air pressure in the chamber to 0.1 kPa. Then open the hydrogen gas valve and introduce hydrogen with a flow rate of 400 sccm. The air pressure gradually rises. When the air pressure rises to 0.8 kPa, ignite and provide an input power of 0.6 kW. Subsequently, the air pressure gradually rises to 18 kPa. During this period, slowly increase the power to 6 kW. At this time, introduce methane with a flow rate of 15 sccm. The deposition temperature is 860 °C, and the deposition time is 24 h;

[0069] S3. Take the diamond diaphragm and polish one side surface. Uniformly coat the etched agent on the surface of the polished diamond diaphragm. Place the side coated with the etched agent face up and press and shape it to form an etched agent layer with a thickness of 300 nm. Transfer it to a vacuum furnace for heat treatment, take it out and cool it to obtain the heat-treated diamond diaphragm;

[0070] The vacuum degree for heat treatment in the vacuum furnace is 3×10 -4 Pa, the temperature is 1020 °C, and the time is 2 h;

[0071] The preparation method of the etched agent includes the following steps:

[0072] A1. Take ferric nitrate nonahydrate and dilute nitric acid solution, stir for 25 min, add potassium hydroxide solution, stir for 40 min, centrifuge and separate, take the solid phase, wash and dry it to obtain material A; the dosage ratio of ferric nitrate nonahydrate, dilute nitric acid solution, and potassium hydroxide solution is 243.6 mg: 10 mL: 35 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0073] A2. Take europium nitrate hexahydrate and dilute nitric acid solution, stir for 25 min, add potassium hydroxide solution, stir for 40 min, centrifuge and separate, take the solid phase, wash and dry it to obtain material B; the dosage ratio of ferric nitrate nonahydrate, dilute nitric acid solution, and potassium hydroxide solution is 258.9 mg: 10 mL: 35 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0074] A3. Take manganese acetate and dilute nitric acid solution, stir for 25 min, add potassium hydroxide solution, stir for 40 min, centrifuge and separate, take the solid phase, wash and dry it to obtain material C; the dosage ratio of manganese acetate, dilute nitric acid solution, and potassium hydroxide solution is 7.612 mg: 10 mL: 35 mL; the mass fraction of the dilute nitric acid solution is 5%; the concentration of the potassium hydroxide solution is 6 mol / L;

[0075] A4. Mix the material A, material B, material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate, ultrasonically disperse for 35 min, transfer to a 100 mL PTFE reaction kettle liner, seal and heat, cool, and discharge to obtain the etchant; the dosage ratio of the material A, material B, material C, potassium hydroxide solution, and niobium(IV) 2-ethylhexanoate is 121.8 mg: 129.4 mg: 3.806 mg: 30 mL: 9.986 mg; the concentration of the potassium hydroxide solution is 12 mol / L; the sealed heating means heating at 200 °C under sealed conditions for 30 h;

[0076] S4. Remove the residual etchant on the surface of the heat-treated diamond diaphragm, and perform copper plating treatment to obtain the heat sink;

[0077] The copper plating treatment operation is an operation method well-known to those skilled in the art. Specifically, it means placing the diamond diaphragm after removing the etchant as the cathode in the copper plating solution, using a phosphorus copper plate as the anode accordingly, placing the copper plating solution on a magnetic stirring table and stirring while depositing metallic copper on the surface of the diamond diaphragm at room temperature using a DC regulated power supply. The constant current electroplating method is adopted, with the current set to be constant at 0.2 A, the time to be 32 h, and the thickness of the electroplated copper to be 0.48 mm;

[0078] The copper plating solution is a high-speed bright copper plating solution purchased from Sigma-Aldrich Corporation, USA, with the product number 900569.

[0079] The heat sink prepared in Example 3 was measured with a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments) to have a thermal conductivity of 718 W / (m·K).

[0080] Comparative Example 1

[0081] The difference from Example 2 is that in the preparation process of the heat sink, in the preparation process of the etchant coated, material A is not added in step A4.

[0082] The heat sink prepared in Comparative Example 1 was measured with a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments) to have a thermal conductivity of 547 W / (m·K).

[0083] Comparative Example 2

[0084] The difference from Example 2 is that in the preparation process of the heat sink, in the preparation process of the etchant coated, material B is not added in step A4.

[0085] The heat sink prepared in Comparative Example 2 was measured with a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments) to have a thermal conductivity of 642 W / (m·K).

[0086] Comparative Example 3

[0087] The difference from Example 2 is that in the preparation process of the heat sink, in the preparation process of the etched agent coated, material C is not added in step A4.

[0088] The heat sink prepared in Comparative Example 3 was measured by a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments) and its thermal conductivity was 657 W / (m·K).

[0089] Comparative Example 4

[0090] The difference from Example 2 is that in the preparation process of the heat sink, in the preparation process of the etched agent coated, niobium(IV) 2-ethylhexanoate is not added in step A4.

[0091] The heat sink prepared in Comparative Example 4 was measured by a DZDR-S thermal conductivity tester (produced by Nanjing Dazhan Testing Instruments) and its thermal conductivity was 635 W / (m·K).

[0092] In summary, the heat sinks prepared in Examples 1-3 of the present application have excellent thermal conductivity.

[0093] In Comparative Example 1, iron element was not doped in the preparation process of the etched agent, resulting in the lack of an iron-based crystal structure in the prepared etched agent, leading to a poor corrosion effect on the diamond crystal interface during the etching process, making it difficult to form a relatively uniform and continuous rough interface, resulting in difficulty in copper plating adhesion and reducing the interface bonding effect, resulting in a low thermal conductivity of the prepared heat sink;

[0094] In Comparative Example 2, europium element was not doped in the preparation process of the etched agent, resulting in the lack of a europium-based crystal structure in the prepared etched agent, leading to the lack of anchor points formed by the europium-based crystal during the etching process, resulting in a reduced etching effect and a low thermal conductivity of the prepared heat sink;

[0095] In Comparative Example 3, manganese element was not doped in the preparation process of the etched agent, resulting in the lack of a manganese-based catalytic effect in the prepared etched agent. Manganese atoms cannot adsorb on the diamond grain boundaries, resulting in a reduced corrosion rate and uneven corrosion, resulting in a low thermal conductivity of the prepared heat sink;

[0096] In Comparative Example 4, niobium element was not doped in the preparation process of the etched agent, resulting in the lack of a niobium-based crystal structure in the prepared etched agent. Niobium failed to form nucleation sites, resulting in poor bonding between copper and the diamond grain boundaries during the copper plating process, and there are voids and serious defects at the interface, resulting in a low thermal conductivity of the prepared heat sink;

[0097] In the present application, a diamond grain boundary is uniformly corroded by introducing an iron-based metal etched agent doped with europium, manganese, and niobium with a synergistic effect, improving the bonding performance between copper and the diamond interface, thereby obtaining a heat sink with excellent heat dissipation effect.

[0098] As described above, these are only the preferred embodiments of the present invention and do not impose any formal limitations on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A manufacturing process for a heat sink for improving heat dissipation efficiency, characterized in that: The following steps are involved: S1, taking a graphite substrate, and uniformly depositing a molybdenum metal layer on the surface of the graphite substrate by magnetron sputtering; S2, cleaning the graphite substrate on which molybdenum is deposited by ultrasonic cleaning, drying, depositing diamond powder on the dried graphite substrate by multifunctional microwave plasma chemical vapor deposition, and then peeling off the graphite substrate by heat treatment to obtain a diamond membrane; S3, taking the diamond membrane and grinding one side of the surface, evenly coating the etchant on the polished surface of the diamond membrane, laying the side coated with the etchant upward and pressing to form an etchant layer, transferring it to a vacuum furnace for heat treatment, taking it out and cooling it, to obtain a heat-treated diamond membrane; S4, taking the heat-treated diamond film, removing the residual etchant on the surface, and performing copper plating to obtain the heat sink.

2. A manufacturing process for a heat sink for improving heat dissipation efficiency according to claim 1, characterized in that: The preparation method of the etching agent comprises the following steps: A1. Mix ferric nitrate nonahydrate and dilute nitric acid solution, stir for 15-25 min, add potassium hydroxide solution, stir for 30-40 min, centrifuge, wash and dry the solid phase to obtain material A; A2, mix europium nitrate hexahydrate and dilute nitric acid solution, stir for 15-25 minutes, add potassium hydroxide solution, stir for 30-40 minutes, centrifuge, wash the solid phase, dry, and obtain material B; A3, mix manganese acetate and dilute nitric acid solution, stir for 15-25 minutes, add potassium hydroxide solution, stir for 30-40 minutes, centrifuge, wash and dry the solid phase to obtain material C; A4. Mix the material A, material B, material C, potassium hydroxide solution and 2-ethylhexanoate niobium (IV), disperse them by ultrasonic for 25-35 min, transfer them to a 100 mL polytetrafluoroethylene-lined reactor, seal and heat, cool, and discharge the mixture to obtain the etchant.

3. A manufacturing process for a heat sink for improving heat dissipation efficiency according to claim 2, characterized in that: In step A1, the dosage ratio of the ferric nitrate nonahydrate, the dilute nitric acid solution, and the potassium hydroxide solution is 241.4-243.6 mg:10 mL:25-35 mL; the mass fraction of the dilute nitric acid solution is 5%; and the concentration of the potassium hydroxide solution is 6 mol / L.

4. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 2, characterized in that: In step A2, the dosage ratio of the ferric nitrate nonahydrate, the dilute nitric acid solution, and the potassium hydroxide solution is 258.7-258.9 mg:10 mL:25-35 mL; the mass fraction of the dilute nitric acid solution is 5%; and the concentration of the potassium hydroxide solution is 6 mol / L.

5. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 2, characterized in that: In step A3, the dosage ratio of the manganese acetate, the dilute nitric acid solution, and the potassium hydroxide solution is 7.608-7.612 mg:10 mL:25-35 mL; the mass fraction of the dilute nitric acid solution is 5%; and the concentration of the potassium hydroxide solution is 6 mol / L.

6. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 2, characterized in that: In step A4, the dosage ratio of material A, material B, material C, potassium hydroxide solution and 2-ethylhexanoate niobium (IV) is 120.7-121.8 mg: 129.3-129.4 mg: 3.804-3.806 mg: 20-30 mL: 9.985-9.986 mg; the concentration of the potassium hydroxide solution is 12 mol / L; and the sealed heating refers to heating at 200° C. under sealed conditions for 20-30 h.

7. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 1, characterized in that: In step S3, the vacuum degree of the heat treatment in the vacuum furnace is 3×10 -4 Pa, temperature is 880-1020℃, time is 1-2h.

8. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 1, characterized in that: In step S1, the thickness of the molybdenum metal layer is 2-3 μm.

9. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 1, characterized in that: In step S3, the thickness of the etchant layer is 200-300 nm.

10. The manufacturing process of a heat sink for improving heat dissipation efficiency according to claim 1, characterized in that: In step S4, the copper plating thickness is 0.32-0.48 mm.