A method for preparing a graphene heat dissipation film for electronic devices by using an electron beam technique

Abstract

The application belongs to the technical field of graphene materials, and discloses a preparation method of graphene heat dissipation film for electronic equipment by using electron beam technology. The carbonization reaction and graphitization reaction of the organic plastic film are carried out by electron beam irradiation to prepare a semi-finished graphene heat dissipation film, and the graphene heat dissipation film is finally obtained by ion titanium infiltration treatment. The graphene heat dissipation film has excellent heat conduction performance and is suitable for heat dissipation components of portable electronic equipment. The graphene heat dissipation film prepared by the method has excellent heat conduction performance and is suitable for heat dissipation components of portable electronic equipment.

Description

Technical Field

[0001] This invention relates to the field of graphene materials technology, and specifically to a method for preparing graphene heat dissipation films for electronic devices using electron beam technology. Background Technology

[0002] Smartphones, laptops, tablets, and smart wearables have become indispensable necessities in our lives. Their functions are increasingly powerful, featuring high-speed processors, high resolution, large screens, high-pixel photography, and more, with an iterative update speed that leaves other technological products far behind. The high integration of functions and the pursuit of thinner and lighter designs have also made heat dissipation a more prominent issue for electronic products. Take smartphones as an example: those who play mobile games for extended periods often experience their phones becoming sluggish due to processor throttling caused by overheating. With the performance of mobile phone processors increasing dramatically every year, overheating is inevitable. The higher the level of the smartphone, the more severe the heat generation of the chip processor, because the chip integrates all the phone's functions, leading to a significant increase in power consumption during operation. For example, 5G phones require more antennas to receive signals, and the high-speed data transmission also increases the phone's heat generation. On the other hand, the mainstream material used in mobile phones today is glass, which dissipates heat significantly slower than metal. Furthermore, the internal components of flagship phones are becoming increasingly compact, such as the screen, rear camera system, and battery, all of which place higher demands on the phone's heat dissipation capabilities.

[0003] Graphene is carbon atoms arranged in sp... 2 Hybridized carbon nanomaterials are high-tech products derived from graphite, due to the large specific surface area of ​​graphene (~2630 m²). 2 / g), electrical conductivity (electron mobility up to ~200000cm⁻¹) 2 With its excellent thermal conductivity (~5300 W / m·k) and unique ultrathin graphite planar structure, it has important properties and structural features, making it a potential excellent heat dissipation and energy storage material.

[0004] Graphene thermal conductive film, also known as graphene heat sink, is a novel and highly efficient thermal interface material. Made from graphene as the raw material, it is a highly oriented thermal film formed by stacking multiple layers of graphene. Compared with other similar heat dissipation materials, it has superior mechanical properties, high thermal conductivity, light weight, thinness, and flexibility, providing high-quality and economical heat dissipation solutions for electronic products, especially in the mobile phone / laptop industry, aerospace, and medical industries.

[0005] Chinese patent CN 107756986 A discloses a graphene heat dissipation film and its preparation method. The preparation process of the graphene heat dissipation film includes steps such as graphene powder preparation, metal substrate coating with graphene powder, roll pressing, and magnetic field induction to change the orientation of graphene. The thermal conductivity (or thermal conductivity coefficient) of the obtained graphene heat dissipation film is between 615 and 688 W / m·K.

[0006] Chinese patent CN108793133A discloses a method for preparing a high thermal conductivity graphene heat dissipation film. The preparation process includes steps such as slurry preparation, coating, pre-reduction treatment, high-temperature graphitization treatment, and rolling. The thermal conductivity of the obtained graphene heat dissipation film is between 1306 and 1504 W / m·K.

[0007] The aforementioned existing technologies are all made by coating or printing graphene oxide or graphene powder and then rolling them. The problem is that the density improvement after rolling is limited. If there are gaps between the graphene particles, it will affect the heat conduction effect. Therefore, the above patents are limited in improving thermal conductivity. Summary of the Invention

[0008] The purpose of this invention is to solve the problems of the prior art and provide a method for preparing graphene heat dissipation film for electronic devices using electron beam technology. The process is simple and easy to scale up. The graphene heat dissipation film prepared by this invention has ultra-high thermal conductivity and is extremely cost-effective, which can solve the heat dissipation problem of electronic devices such as smartphones and tablets.

[0009] The aforementioned methods can be solved by carbonizing and graphitizing benzene-ring-containing organic plastic films (polyimide films or polyester (PET) films). The carbonization reaction removes other elements from the organic plastic, followed by a graphitization reaction to produce a graphene heat dissipation film with optimal density. The polyimide or polyester (PET) film contains benzene ring structures (where carbon atoms are sp2 hybridized), which serve as the core for graphene growth and as a bridge connecting the graphene layers. This creates more active sites, allowing supersaturated carbon atoms to form a graphene film with the benzene rings. Electron beams are excellent high-energy heat sources, enabling the carbonization and graphitization of benzene-ring-containing organic plastic films under vacuum conditions. The high energy carried by the electron beam rapidly completes the carbonization and graphitization reactions, thus preparing a graphene heat dissipation film. Due to the low cost of benzene-ring-containing organic plastics, the graphene heat dissipation film produced by this method has a cost advantage, expanding its application in the field of heat dissipation for electronic devices.

[0010] The technical solution of the present invention is as follows: A method for preparing a graphene heat dissipation film for electronic devices using electron beam technology, comprising the following steps:

[0011] Step (1), Surface treatment of benzene ring-containing organic plastic film: Wipe the surface of the benzene ring-containing organic plastic film with acetone or anhydrous ethanol;

[0012] Step (2), Electron beam scanning treatment: The benzene ring-containing organic plastic film that has undergone surface treatment is placed into the vacuum chamber of the electron beam welding machine. The process parameters of the electron beam equipment are adjusted, and high-energy electron beam treatment is applied to carbonize and graphitize the benzene ring-containing organic plastic film to prepare a semi-finished graphene heat dissipation film.

[0013] Step (3), Ion Titanium Diffusion Treatment: The semi-finished graphene heat dissipation film prepared in step (2) is subjected to titanium diffusion treatment using a cathode arc ion plating device to generate a titanium diffusion layer. The titanium diffusion process is as follows: vacuum degree 5.5×10 -2 The heating temperature is 150–300℃, the argon pressure is 0.2–0.5 Pa, the arc current is 50–90 A, the bias voltage amplitude is 750–900 V, the target distance is 100–200 mm, and the titanium infiltration time is 1–2 h, finally obtaining a graphene heat dissipation film.

[0014] The benzene ring-containing organic plastic film is a polyimide film or a polyester film.

[0015] The process parameters of the electron beam equipment are: electron beam power 4–15 kW, accelerating voltage 8–20 kV, current 100–1000 mA, and working chamber vacuum degree 6.5 × 10⁻⁶. -3 Pa, the scanning frequency is 5-10kHz, and the scanning waveform is a square wave or a sine wave.

[0016] The thickness of the semi-finished graphene heat dissipation film is 10–1000 μm.

[0017] The thickness of the titanium-diffused layer obtained by the ion titanium diffusion treatment in step (3) is 1 to 10 μm.

[0018] The beneficial effects of this invention are as follows: This invention designs a method for preparing graphene heat dissipation films for electronic devices using electron beam technology. The method utilizes electron beam irradiation to induce carbonization and graphitization reactions in an organic plastic film, preparing a semi-finished graphene heat dissipation film. This semi-finished film is then subjected to ion-distillation titanium diffusion treatment to finally obtain the finished graphene heat dissipation film. This graphene heat dissipation film possesses excellent thermal conductivity and is suitable for application in heat dissipation components of portable electronic devices.

[0019] The electron beam welding equipment of the present invention is suitable for processing large-area organic plastic films, which can ensure complete carbonization and graphitization of the processing area, and carbonization under vacuum conditions will not introduce impurities, while thoroughly removing elements other than carbon generated by the carbonization reaction; the subsequent graphitization reaction can quickly form a semi-finished graphene heat dissipation film. Attached Figure Description

[0020] Figure 1Photograph of the graphene heat dissipation film of this invention;

[0021] Figure 2 SEM cross-sectional image of the graphene heat dissipation film of the present invention;

[0022] Figure 3 Comparison of thermal conductivity of Examples 1-3 and Comparative Examples 1-3. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] Example 1

[0025] A method for preparing graphene heat dissipation films for electronic devices using electron beam technology, the specific preparation process of which is as follows:

[0026] Step (1), Surface treatment of benzene ring-containing organic plastic film: Wipe the surface of the benzene ring-containing organic plastic film with acetone or anhydrous ethanol;

[0027] Step (2), Electron beam scanning treatment: The benzene ring-containing organic plastic film that has undergone surface treatment is placed into the vacuum chamber of the electron beam welding machine. The process parameters of the electron beam equipment are adjusted, and high-energy electron beam treatment is applied to carbonize and graphitize the benzene ring-containing organic plastic film to prepare a semi-finished graphene heat dissipation film.

[0028] Step (3), Ion Titanium Diffusion Treatment: The semi-finished graphene heat dissipation film prepared in step (2) is subjected to titanium diffusion treatment using a cathode arc ion plating device to generate a titanium diffusion layer. The titanium diffusion process is as follows: vacuum degree 5.5×10 -2 The heating temperature was 150℃, the argon pressure was 0.2Pa, the arc current was 50A, the bias voltage amplitude was 750V, the target distance was 100mm, and the titanium infiltration time was 2h, finally obtaining a graphene heat dissipation film.

[0029] The benzene ring-containing organic plastic film mentioned in step (1) is a polyimide film or a polyester (PET) film;

[0030] The process parameters of the electron beam equipment are: electron beam power 4W, accelerating voltage 8KV, current 100mA, and working chamber vacuum degree 6.5×10⁻⁶. -3 Pa, the scanning frequency is 5KHz, and the scanning waveform is a square wave;

[0031] The thickness of the semi-finished graphene heat dissipation film is 10 μm.

[0032] The thickness of the titanium-diffused layer obtained by the ion titanium diffusion treatment in step (3) is 1 μm.

[0033] The thermal conductivity of the graphite heat dissipation film was found to be 2050 W / m·K through thermal conductivity testing.

[0034] The purpose of this invention's ion-plating titanium diffusion treatment is to prevent carbon oxidation during the mobile phone's service life, which would affect the thermal conductivity of the heat dissipation film. Compared to other titanium diffusion technologies, the titanium diffusion layer prepared using cathode arc ion plating equipment is thinner, and the titanium diffusion layer mainly contains titanium carbide, which can effectively prevent carbon oxidation during the mobile phone's service life. The thickness of the titanium diffusion layer can be controlled within the range of 10 μm, without affecting the thermal conductivity of the graphene heat dissipation film. Other titanium diffusion technologies produce titanium diffusion layers that are too thick, affecting the thermal conductivity of the heat dissipation film. Therefore, cathode arc ion plating titanium diffusion technology is chosen as the highlight of this invention.

[0035] Example 2

[0036] A method for preparing graphene heat dissipation films for electronic devices using electron beam technology, the specific preparation process of which is as follows:

[0037] Step (1), Surface treatment of benzene ring-containing organic plastic film: Wipe the surface of the benzene ring-containing organic plastic film with acetone or anhydrous ethanol;

[0038] Step (2), Electron beam scanning treatment: The benzene ring-containing organic film that has undergone surface treatment is placed into the vacuum chamber of the electron beam welding machine, the process parameters of the electron beam equipment are adjusted, and high-energy electron beam treatment is applied to carbonize and graphitize the benzene ring-containing organic plastic film to prepare a semi-finished graphene heat dissipation film.

[0039] Step (3), Ion Titanium Diffusion Treatment: The semi-finished graphene heat dissipation film prepared in step (2) is subjected to titanium diffusion treatment using a cathode arc ion plating device to generate a titanium diffusion layer. The titanium diffusion process is as follows: vacuum degree 5.5×10 -2 The heating temperature was 200℃, the argon pressure was 0.3Pa, the arc current was 70A, the bias voltage amplitude was 800V, the target distance was 150mm, and the titanium infiltration time was 1.5h, finally obtaining a graphene heat dissipation film.

[0040] Preferably, the benzene ring-containing organic plastic film mentioned in step (1) is a polyimide film or a polyester (PET) film;

[0041] The process parameters of the electron beam equipment are: electron beam power 10kW, accelerating voltage 14KV, current 500mA, and working chamber vacuum degree 6.5×10⁻⁶. -3 Pa, the scanning frequency is 8KHz, and the scanning waveform is a sine wave.

[0042] The thickness of the semi-finished graphene heat dissipation film is 500 μm.

[0043] The thickness of the titanium-diffused layer obtained by the ion titanium diffusion treatment in step (3) is 5 μm.

[0044] The thermal conductivity of the graphite heat dissipation film was found to be 2578 W / m·K through thermal conductivity testing.

[0045] Example 3

[0046] A method for preparing graphene heat dissipation films for electronic devices using electron beam technology, the specific preparation process of which is as follows:

[0047] Step (1), Surface treatment of benzene ring-containing organic plastic film: Wipe the surface of the benzene ring-containing organic plastic film with acetone or anhydrous ethanol;

[0048] Step (2), Electron beam scanning treatment: The benzene ring-containing organic plastic film that has undergone surface treatment is placed into the vacuum chamber of the electron beam welding machine. The process parameters of the electron beam equipment are adjusted, and high-energy electron beam treatment is applied to make the benzene ring-containing organic plastic film carbonized and graphitized to prepare a semi-finished graphene heat dissipation film.

[0049] Step (3), Ion Titanium Diffusion Treatment: The semi-finished graphene heat dissipation film prepared in step (2) is subjected to titanium diffusion treatment using a cathode arc ion plating device to generate a titanium diffusion layer. The titanium diffusion process is as follows: vacuum degree 5.5×10 -2 The heating temperature was 300℃, the argon pressure was 0.5Pa, the arc current was 90A, the bias voltage amplitude was 900V, the target distance was 200mm, and the titanium infiltration time was 1h, finally obtaining a graphene heat dissipation film.

[0050] Preferably, the benzene ring-containing organic plastic film mentioned in step (1) is a polyimide film or a polyester (PET) film;

[0051] The process parameters of the electron beam equipment are: electron beam power 15kW, accelerating voltage 20KV, current 1000mA, and working chamber vacuum degree 6.5×10⁻⁶. -3 Pa, the scanning frequency is 10KHz, and the scanning waveform is a sine wave; the thickness of the semi-finished graphene heat dissipation film is 1000μm.

[0052] The thickness of the titanium-diffused layer obtained by the ion titanium diffusion treatment in step (3) is 10 μm.

[0053] The thermal conductivity of the graphite heat dissipation film was found to be 2386 W / m·K through thermal conductivity testing.

[0054] Comparative Example 1: Unlike Example 2, an organic plastic film containing non-benzene rings, such as a polyethylene plastic film, was used for electron beam scanning. The thermal conductivity of the heat dissipation film in Comparative Example 1 is 1563 W / m·K. Since the polyethylene plastic film does not contain benzene rings, only carbonization occurs during electron beam irradiation, and no graphitization occurs. Therefore, the heat dissipation film of Comparative Example 1 has poor thermal conductivity.

[0055] Thermal conductivity test of graphene heat dissipation film:

[0056] Examples 1-3 and Comparative Examples 1-3 of this invention used laser scattering method to test the thermal conductivity of the materials at room temperature (25°C) using a flash thermal conductivity meter (model LFA-447). Four points were measured for each sample, and the average thermal conductivity was taken. A comparison of the thermal conductivity of Examples 1-3 and Comparative Examples 1-3 is shown below. Figure 3 . Figure 3 The graphene heat dissipation films of Examples 1-3 of the present invention have better thermal conductivity than those of Comparative Examples 1-3.

[0057] Comparative Example 2: Unlike Example 2, the process parameters of the electron beam equipment are: electron beam power 20kW, accelerating voltage 23kV, current 1200mA, and working chamber vacuum degree 6.5×10⁻⁶. -3 Pa, scanning frequency of 5-10KHz, scanning waveform sine wave. The above parameters exceed the normal range of Examples 1-3. The consequence is that the carbon is burned off due to excessive energy, resulting in a large number of perforations in the graphene heat dissipation film, making its integrity poor and resulting in poor thermal conductivity of the graphene heat dissipation film. In this example, the thermal conductivity of the graphene heat dissipation film is 756W / m·k.

[0058] Comparative Example 3: Unlike Example 2, the ion titanium diffusion treatment was removed, and the thermal conductivity of the graphene heat dissipation film was tested at 300°C. Since the graphene heat dissipation film will oxidize at this temperature, the thermal conductivity will be slightly worse. In this example, the thermal conductivity of the graphene heat dissipation film is 2312 W / m·K.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a graphene heat dissipation film for electronic devices using an electron beam technique, characterized by, The steps include the following: Step (1) Surface treatment of benzene ring-containing organic plastic film: Wipe the surface of the benzene ring-containing organic plastic film with acetone or anhydrous ethanol; Step (2), Electron beam scanning treatment: The benzene ring-containing organic plastic film that has undergone surface treatment is placed into the vacuum chamber of the electron beam welding machine. The process parameters of the electron beam equipment are adjusted, and high-energy electron beam treatment is applied to carbonize and graphitize the benzene ring-containing organic plastic film to prepare a semi-finished graphene heat dissipation film. Step (3), Ion Titanium Diffusion Treatment: The semi-finished graphene heat dissipation film prepared in step (2) is subjected to titanium diffusion treatment using a cathode arc ion plating device to generate a titanium diffusion layer. The titanium diffusion process is as follows: vacuum degree 5.5×10 -2 The heating temperature is 150~300℃, the argon pressure is 0.2~0.5Pa, the arc current is 50~90A, the bias voltage amplitude is 750~900V, the target distance is 100~200mm, and the titanium infiltration time is 1~2h, finally obtaining a graphene heat dissipation film. The thickness of the titanium-diffused layer obtained by the ion titanium diffusion treatment is 1~10 μm; The process parameters of the electron beam equipment are 4-15 kW of electron beam power, 8-20 kV of acceleration voltage, 100-1000 mA of current, 6.5*10 -3 Pa of working chamber vacuum degree, 5-10 kHz of scanning frequency, and square wave or sine wave of scanning waveform.

2. The method of claim 1, wherein the graphene heat dissipation film for electronic devices is prepared using an electron beam technique. The benzene ring-containing organic plastic film is a polyimide film or a polyester film.

3. The method of claim 1, wherein the graphene heat dissipation film for electronic devices is prepared using an electron beam technique. The thickness of the semi-finished graphene heat dissipation film is 10~1000 μm.

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