Manufacturing method of radiator with diamond coating

Abstract

The invention provides a manufacturing method of a radiator with a diamond coating, and belongs to the field of machine manufacturing. The method solves the problems that the density of a composite material is not high and the heat conductivity is not easy to improve due to poor wetting degree of a diamond and copper interface at present. A manufacturing method of a radiator with a diamond coating comprises the steps that a, a copper or aluminum radiator is subjected to acid etching; b, surface sand blasting is carried out on the acid-etched radiator, diamond powder with the particle size being 1-5 microns is used, and the bottom face and cooling fins of the radiator need to be treated; c, the surface of the radiator is etched through laser, linear grooves with the width of 10-20 microns and the depth of 5-15 microns are formed in the surface, and the grooves are distributed in the whole surface; d, a diamond powder ethanol solution is adopted, the radiator is immersed in the diamond powder ethanol solution, ultrasonic vibration is conducted for 30-60 min, and crystal planting is completed; and e, diamond coating is conducted on the radiator in hot filament CVD, the coating is formed by micro-nano composite alternation, the total number of layers is 4-7, and the CVD technology is completed. The method has the advantage that the heat conduction and heat dissipation capabilities of the diamond can be utilized to a greater extent.

Description

Technical Field

[0001] The invention belongs to the field of mechanical manufacturing, and in particular relates to a method for manufacturing a radiator with a diamond coating. Background Art

[0002] A radiator is a device that dissipates heat from heat-prone electronic components in electrical appliances. It is usually made of aluminum alloy, brass or bronze in the form of plates, sheets, or multiple sheets. Generally, a layer of thermal conductive silicone grease should be applied to the contact surface between the electronic component and the bottom of the radiator during use, so that the heat generated by the components can be more effectively transferred to the radiator and then dissipated into the surrounding air through the heat sink.

[0003] In order to prepare a heat sink with better heat dissipation efficiency, excellent heat dissipation efficiency can be obtained by improving the thermal conductivity. However, silver with better thermal conductivity is expensive and difficult to apply in practice. Therefore, other materials with better thermal conductivity than copper and aluminum need to be used. Among them, diamond is an ideal material. Diamond not only has the highest hardness, but also has the highest thermal conductivity among currently known materials. At present, the thermal conductivity of CVD diamond film at room temperature (1000~2000W / mK) is close to the thermal conductivity of natural diamond. Therefore, if a layer of CVD diamond film is coated on the heat sink, the heat conduction and dissipation can be improved, thereby improving the performance of the heat sink.

[0004] The current combination application method of diamond and heat sink is to melt diamond powder and copper powder together to make a composite material. The wettability of the diamond and copper interface is poor, resulting in low density of the composite material and difficulty in improving thermal conductivity. Summary of the invention

[0005] The purpose of the present invention is to provide a method for manufacturing a heat sink with a diamond coating and better heat dissipation efficiency in order to solve the above problems in the prior art.

[0006] The object of the present invention can be achieved by the following technical solution: A method for manufacturing a heat sink with a diamond coating, characterized in that it comprises the following steps: Step a: etching the copper or aluminum heat sink with a mixed solution of nitric acid and hydrogen peroxide to obtain a surface with a roughness of 100-500 nm; Step b: sandblast the surface of the acid-etched heat sink using diamond powder with a particle size of 1-5 um. The bottom surface of the heat sink (the surface in contact with the electronic components) and the heat sink must be processed to obtain a surface roughness of 3-6 um. Step c: Use laser to etch the surface of the heat sink to form straight grooves with a width of 10-20um and a depth of 5-15um on the surface, with a groove spacing of 200um-500um, and the grooves cover the entire surface; Step d: using a diamond powder ethanol solution, immersing the heat sink in the diamond powder ethanol solution, and ultrasonically vibrating for 30-60 minutes to complete the crystal planting; Step e: Diamond coating the heat sink in the hot wire CVD, the process is 0.5-0.9 kPa, the carbon source concentration is 1%-3.5%, the hot wire arrangement spacing is 15-35 mm, the coating is micro-nano composite alternation, the total number of layers is 4-7 layers, the coating time is 10-20 hours, the coating thickness is 15-30 um, and the CVD process is completed.

[0007] In the above-mentioned method for manufacturing a heat sink with a diamond coating, the volume ratio of nitric acid to hydrogen peroxide is 4:6, and the acid etching time is 10-30 seconds.

[0008] In the above-mentioned method for manufacturing a heat sink with a diamond coating, the particle size of the diamond powder is 0.02-1um, and the mass ratio of the diamond powder to ethanol is 1:1000.

[0009] In the above-mentioned method for manufacturing a heat sink with a diamond coating, the heat sink manufacturing method is implemented by a heat sink manufacturing device.

[0010] In the above-mentioned method for manufacturing a heat sink with a diamond coating, the heat sink manufacturing equipment includes a heat sink body, characterized in that a diamond coating is provided on the heat sink body, and a laser-etched groove is provided between the diamond coating and the heat sink.

[0011] In the above-mentioned method for manufacturing a heat sink with a diamond coating, the diamond coating includes a micron layer and a nano diamond layer.

[0012] Compared with the prior art, the present method for manufacturing a heat sink with a diamond coating generates a diamond coating on the surface of a copper or aluminum heat sink by chemical vapor deposition, and uses a complex pre-treatment method to ensure the bonding strength between the coating and the substrate, thereby avoiding the risk of coating shedding and tearing caused by the different expansion coefficients of copper or aluminum and diamond. At the same time, by using extremely low air pressure to ensure that the diamond coating can be deposited in all areas of the heat sink, the continuity and large surface area of ​​the diamond coating can make greater use of the thermal conductivity and heat dissipation capabilities of diamond. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a heat sink structure diagram showing a method for manufacturing a heat sink with a diamond coating.

[0014] Figure 2 The present invention is a diamond coating structure diagram showing a method for manufacturing a heat sink with a diamond coating.

[0015] In the figure, 1. Radiator body; 2. Diamond coating; 3. Micron layer; 4. Nano diamond layer; 5. Laser etched grooves. DETAILED DESCRIPTION

[0016] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0017] like Figure 1 , Figure 2 As shown, the method for manufacturing a heat sink with a diamond coating comprises the following steps: Step a: etching the copper or aluminum heat sink with a mixed solution of nitric acid and hydrogen peroxide to obtain a surface with a roughness of 100-500 nm; Step b: sandblasting the surface of the acid-etched heat sink, using diamond powder with a particle size of 1-5 um. The bottom surface of the heat sink (i.e., the surface in contact with the electronic components) and the heat sink must be processed by acid etching, sandblasting, and etching. Although the surface of the substrate after acid etching is uneven, its concave or convex parts are relatively smooth, which is not suitable for the diamond coating 2 to combine with the substrate. Therefore, sandblasting is required to form a fine structure with edges and corners on the surface to obtain a surface roughness of 3-6 um; Step c: Use laser to etch the surface of the heat sink to form straight grooves with a width of 10-20um and a depth of 5-15um. The groove spacing is 200um-500um, and the grooves cover the entire surface. The grooves etched by the laser on the surface can play a pinning role and enhance the bonding force between the diamond 2 coating and the heat sink body 1.

[0018] Step d: using a diamond powder ethanol solution, immersing the heat sink in the diamond powder ethanol solution, and ultrasonically vibrating for 30-60 minutes to complete the crystal planting; Step e: Diamond coating is performed on the heat sink in hot wire CVD, the process is 0.5-0.9 kpa, the carbon source concentration is 1%-3.5%, the hot wire arrangement spacing is 15-35 mm, the coating is micro-nano composite alternation, the total number of layers is 4-7 layers, the coating time is 10-20 hours, the coating thickness is 15-30 um, the heat sink structure is generally a sheet-like upright parallel arrangement, which is a complex shape in the CVD process, and there are too many areas blocked to deposit diamonds. Therefore, the CVD process of the present invention adopts extremely low gas pressure to improve the free path fluidity of the active group, ensure that diamonds can be deposited in all areas, and complete the CVD process.

[0019] In further detail, the volume ratio of nitric acid to hydrogen peroxide is 4:6, and the etching time is 10-30 seconds.

[0020] To be more specific, the particle size of the diamond powder is 0.02-1 um, and the mass ratio of the diamond powder to ethanol is 1:1000.

[0021] To further elaborate, the heat sink manufacturing method is implemented by a heat sink manufacturing device.

[0022] To further elaborate, the heat sink manufacturing equipment includes a heat sink body 1, on which a diamond coating 2 is provided, and a laser-etched groove 5 is provided between the diamond coating 2 and the heat sink. The grains of the diamond coating 2 are very small, and they are deposited on the surface of the copper or aluminum heat sink to increase the heat dissipation area.

[0023] In further detail, the diamond coating includes a micron layer 3 and a nano-diamond layer 4, which increases the toughness of the coating and can avoid tearing of the coating due to the different expansion coefficients of the diamond coating 2 and the heat sink body 1 when heated.

[0024] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0025] Although the terms such as heat sink body 1, diamond coating 2, micron layer 3, nano diamond layer 4, laser etched groove 5 are frequently used in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for manufacturing a heat sink with a diamond coating, characterized in that: The following steps are involved: Step a: etching the copper or aluminum heat sink with a mixed solution of nitric acid and hydrogen peroxide to obtain a surface with a roughness of 100-500 nm; Step b: sandblast the surface of the acid-etched heat sink using diamond powder with a particle size of 1-5 um. The bottom surface of the heat sink (the surface in contact with the electronic components) and the heat sink must be processed to obtain a surface roughness of 3-6 um. Step c: Use laser to etch the surface of the heat sink to form straight grooves with a width of 10-20um and a depth of 5-15um on the surface, with a groove spacing of 200um-500um, and the grooves cover the entire surface; Step d: using a diamond powder ethanol solution, immersing the heat sink in the diamond powder ethanol solution, and ultrasonically vibrating for 30-60 minutes to complete the crystal planting; Step e: Diamond coating the heat sink in the hot wire CVD, the process is 0.5-0.9 kPa, the carbon source concentration is 1%-3.5%, the hot wire arrangement spacing is 15-35 mm, the coating is micro-nano composite alternation, the total number of layers is 4-7 layers, the coating time is 10-20 hours, the coating thickness is 15-30 um, and the CVD process is completed.

2. The method for manufacturing a heat sink with a diamond coating according to claim 1, characterized in that: The volume ratio of the nitric acid to the hydrogen peroxide is 4:6, and the acid etching time is 10-30 seconds.

3. The method for manufacturing a heat sink with a diamond coating according to claim 1, characterized in that: The particle size of the diamond powder is 0.02-1um, and the mass ratio of the diamond powder to ethanol is 1:1000.

4. The method for manufacturing a heat sink with a diamond coating according to claim 1, wherein the method for manufacturing a heat sink is implemented by a heat sink manufacturing device.

5. A method for manufacturing a heat sink with a diamond coating according to claim 4, wherein the heat sink device comprises a heat sink body (1), characterized in that: The heat sink body (1) is provided with a diamond coating (2), and a laser-etched groove (5) is provided between the diamond coating (2) and the heat sink.

6. A method for manufacturing a heat sink with a diamond coating according to claim 5, wherein the diamond coating comprises a micron layer (3) and a nano-diamond layer (4).

Images